Feed subscribe
You reached this site via searching Antimony Trioxide on http://www.google.com/. my blog mainly concerns the China Antimony market. If you are new to here and think my information is useful to you, you are highly recommend to subscribe this blog.powered by Feedsky
Tuesday, 28 August 2007
[+/-] : Metals bolster Russia's profits, power
Wearing fireproof coveralls, Ilya Dmitriyev plods past a smelter that belches smoke and gushes molten metal, the chief product of this gritty patch of Arctic tundra where the air tastes of sulphur and concrete apartment blocks crumble on the shifting permafrost.
This is the home of Norilsk Nickel, a former slave labour camp – once part of the dictator Josef Stalin's infamous Gulag – that is now the grey capital of Russia's glittering new metals empire.
Since President Vladimir Putin came to power in 2000, oil and natural gas have fuelled Russia's economic rebirth, creating a generation of young Russian billionaires. Now metal is Russia's latest natural resource bonanza.
The rise of the industry has delighted investors but has caused disquiet among foreign security analysts. Some fear Moscow might use its vast mineral wealth as a tool for coercive diplomacy, the way many believe the Kremlin has used oil and gas supplies to punish western-leaning former Soviet nations.
As the output of Chinese and Indian factories surged last year, the price of nickel leapt 64 percent to an average of $24,155 per ton on the London Metal Exchange, more than doubling Norilsk Nickel's profits. While the price has retreated from a high of over $50,000 per ton in May, it currently trades at around $29,000 a ton.
Workers like Dmitriyev have benefited. Wages here rose 40 percent in April, and Norilsk's smelter workers now earn about $1,500 monthly – triple the national average.
But the big winners at Norilsk are the company's two 40-something shareholders, the cautious Vladimir Potanin and the flamboyant bachelor Mikhail Prokhorov.
In the last year, their personal fortunes more than doubled, to more than $13.5 billion each, according to Forbes magazine. Russia's top five metals magnates – including Potanin and Prokhorov – saw their combined value jump 70 percent last year, to $66 billion, Forbes said.
Through Norilsk, these two men control half of the world's output of palladium, which is used in catalytic convertors, and one fifth of its nickel – a key ingredient in stainless steel.
Prices have risen sharply for most metals Russia produces, not just nickel. Copper is up 30 percent this year. Average aluminium prices rose 36 percent last year; the metal is currently trading 8 percent above the 2006 average. Iron ore prices have doubled in the last three years. Meanwhile, Russia's low electricity rates and wages have made mining companies more profitable than their competitors abroad.
Russia's mineral wealth has few rivals. A local legend says as God scattered riches around the world, his hands froze when he came to Norilsk and dropped everything that he was carrying.
Record profits have driven a wave of acquisitions. Of the $9.5 billion spent on acquisitions by Russian companies last year, metals companies accounted for 84 percent, Russian Mergers & Acquisitions magazine reports. This year, that figure could double.
In June, Norilsk acquired control of a Canadian mining operation, LionOre, in a $6.4 billion deal – the largest-ever Russian purchase overseas. The deal adds nickel mines and processing plants in Australia, South Africa and Botswana to the company's portfolio.
Norilsk also controls Stillwater Mining Co. of Montana, the only U.S. platinum and palladium miner. This year it paid $408 million for the Cleveland-based OM Group Inc.'s nickel assets in Australia and Finland.
Created to strengthen Stalin's USSR, Norilsk Nickel – like so many Soviet mammoths – was sold for a song by President Boris Yeltsin to politically connected bankers in the 1990s.
But analysts praise Potanin and Prokhorov for streamlining a sprawling, debt-laden colossus into a modern multinational. The company controls mines and refineries in eight countries and employs tens of thousands of workers across the globe.
But it is just one of Russia's metals titans.
More than 12 percent of global aluminium output comes from the privately owned UC Russian Aluminum, the world's biggest producers of the vital metal. Russia's state-owned mines and stockpiles account for 20 percent of the world's uranium, more than any single country. A mining company controlled by the state arms exporter, Rosoboronexport, is the world's biggest producer of titanium.
Without titanium from Russia's VSMPO-Avisma, Boeing Co.'s 787 Dreamliner and Airbus's A350 XWB couldn't fly, analysts say. The metal is also critical to Lockheed Martin Corp.'s F-35 Joint Strike Fighter, an advanced fighter bomber being jointly developed by Britain and the U.S.
In the West, there is quiet concern Russia will use its clout in the metals market to help consolidate its geopolitical power.
"Due to Russia's actions on the nonferrous metals markets, there have been claims of manipulation or dubious behaviour," Robert Larsson of the Swedish Defense Research Agency wrote in a report. "As the sector by and large is shielded from insight and data are secret or unreliable, it is hard to assess, but it is clear that Russia's impact on the markets is substantial."
Metals are too easily moved around for Russia to cut off supplies to a single country, as it can with piped gas. But any interruptions at mines like Norilsk's would have a huge impact on markets.
"A Russian decision, or threat, to cut off supplies of minerals would certainly drive the world price up – probably significantly," said Liam Anderson, co-author of the book "Strategic Minerals and Global Geo-Economics."
Disruptions in nickel or aluminium supplies, he said, "would have a trickle-down effect throughout the global economy."
For now, Norilsk Nickel is ostensibly free to act independently. Outside Russia its shares trade in the U.S., Britain and Germany. Some of them are held by investment funds, about 22 percent is held by the Bank of New York as ADRs. But the company may be less independent of the Kremlin than it seems, and even this nominal autonomy may not last.
The company has long been rumoured to be a Kremlin takeover target.
Prokhorov, a 6-foot-7 playboy, has pledged to sell his stake by the end of the year to Potanin, his long-time business partner. That would give Potanin, a more politic figure, 52 percent of the company, and he has said it wouldn't be "a tragedy" if the government bought up Norilsk.
Tycoons who cross the Kremlin find their businesses scrutinized, or even the target of criminal investigations. More than a dozen are wanted in Russia and are currently living abroad.
A Kremlin spokesman declined to comment on the possibility.
Prokhorov's withdrawal was announced shortly after French police detained him at a posh Alpine ski resort in France on suspicion of involvement in a prostitution ring. In the end no charges were filed, but the incident became tabloid fodder in Russia and abroad. He left his post as general director in April.
The company said Prokhorov had long planned to sell his stake. But industry watchers suspect the Kremlin used the case to force Prokhorov out.
"Norilsk clearly stands out as one of Russia's strategically important companies, where the state doesn't have a significant equity stake," said Chris Weafer, chief strategist with Moscow's Alfa Bank.
That could change, he said: "Rather than sitting in the Kremlin saying 'this what we would like you to do,' it's much better to sit on the board and say 'this is what we're going to do.'"
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
[+/-] : Govt can run titanium project: Nedumaran
Demanding a committee headed by a retired High Court judge to go into the stand taken by both the DMK government and the previous AIADMK regime on the Tatas' proposed titanium dioxide plant, Tamils Nationalist Movement leader P Nedumaran sought to know why the government itself could not take up the project.
In a release here, he said all documents relating to the projects should be perused by the committee.
Raising a volley of questions about the project, he said the government should also come out with all truths about the project before conducting public hearing.
He said a DMK Minister at the Centre had spoken in favour of the project and the party's MLAs had participated in a rally conducted by the minister in support of the project.
"It is unfair and clear cheating that the government had now formed a committee of higher officials and ministers to know about the public opinion on the project," he said.
Though the MoU for the project was signed in 2002 when the AIADMK was in power, it was not implemented till 2006, he said and sought to know the reason behind the delay.
Seeking to know the reason for expediting the project now, he also asked why the government was not running the project when the profit was projected at Rs 1,000 crore a year.
There was also an opinion that 500 acres of land was enough for the project, he said and asked why the government was keen to acquire 16,000 acres.
Besides, he also wanted to know why Tatas had been allowed to draw 1.20 lakh gallons of Tamirabarani river water a day. He wondered why the government, instead of acquiring land using the Mining Act, was buying lands from the farmers.
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
Monday, 27 August 2007
[+/-] : On titanium dioxide, 'the whitest of white' pigments
In the latest controversy surrounding land acquisition for corporate projects, the titanium dioxide plant proposed to be set up the Tata Group in Tirunelveli district of Tamil Nadu has run into rough weather, with the local population expressing opposition and several political parties threatening agitations. The project is being opposed on environmental grounds and fear of loss of livelihood.
But what exactly is ilmenite and what are the industrial uses of titanium, which is extracted from it, and its dioxide?
Speaking to Business Line on the extraction and applications of titanium metal and titanium dioxide, Dr C.H. Krishnamurthi Rao, Chairman of Titanium Equipment and Anode Mfg Co Ltd (TEAM), a Chennai-based company, said that titanium dioxide, as the "whitest of white" pigments, finds extensive use in quality paints, paper and plastics.
"It is also used as an opacifying agent in cosmetics and printing inks, radioactive decontamination of the skin, glassware, ceramics and floor coverings. Besides, it finds application in delustering of synthetic fibres and lustrous finishing of cottons."
According to him, titanium dioxide is also used in high-temperature transducers in electronics and in the coating of welding rods.
On titanium metal, he said that as a non-corrosive metal having the "great advantage" of strength-to-weight ratio and high temperature heat resistance, it is the preferred structural material in aircraft, jet engines, missiles and satellites.
"It finds special applications in desalination, chlorine production and textile equipment."
Dr Rao's company, TEAM, has undertaken manufacture of titanium electrodes for use in caustic soda and other electrolytic industries.
"The availability of titanium electrodes was also responsible for the development and propagation of membrane cell technology in India, thus completely eliminating mercury pollution from the caustic soda industries."
TEAM had also involved itself in life science operations by manufacturing titanium hip and shoulder orthopaedic replacements and inserts.
According to Dr Rao, titanium metal is preferred because of its compatibility with biological fluids.
Desalination plants are another area offering immense potential, he added.
Stating that ilmenite, the titanic iron ore, is available in beach sand in areas like Kanyakumari in Tamil Nadu, Dr Rao said that after mining and beneficiation, it takes three streams of commercial products – upgraded ilmenite or synthetic rutile, chemical titanium dioxide and titanium metal.
"DCW Ltd manufactures upgraded ilmenite or synthetic rutile, which has 95 per cent of titanium dioxide content. It is only a raw material used in the manufacture of the dioxide. DCW produces around 42,000 tonnes of upgraded synthetic rutile."
Informing that titanium dioxide is manufactured by the chlorination of the ilmenite, he said that Kerala Minerals and Metals manufactures the dioxide through the rutile process, "wherein ilmenite ore is upgraded to make synthetic rutile, which is further upgraded to titanium tetrachloride. This is used in making titanium dioxide of rutile grade. Kerala Minerals and Metals produces around 36,000 tonnes of titanium dioxide." There are, however, environmental issues, especially relating to effluents.
For extraction of titanium metal, ilmenite is subjected to the process of reduction, using sodium or magnesium.
"The titanium sponge thus obtained is consolidated by melting, which requires highly sophisticated technology."
Dr Rao added that the Tatas have only said that they would be making titanium dioxide "but not specified what process they will be using – rutile or sulphate. For the rutile process, hydrochloric acid is used to leach ilmenite ore, while in sulphuric acid is used in the other. The rutile grade dioxide is superior in quality and price."
He also said that ilmenite ore containing minor quantities of monazite was earlier classified under the category of radioactive materials.
"The exploration, processing, export and import of these ores were under the vigilant control of the Mines and Minerals Act and the Atomic Energy Commission."
So far, the manufacture of titanium dioxide was the monopoly of public sector undertakings.
"Kerala Minerals and Metals remains the only indigenous source for titanium dioxide, and MIDHANI, Hyderabad, for titanium-rolled products out of imported titanium metal sponge (similar to ingots)."
Dr Rao attributed the flurry of investment in products based on ilmenite ore to the constant demand and bright prospects for both the chemical and metallic versions of titanium. – The Hindu
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
Thursday, 23 August 2007
[+/-] : Stabilization of red amorphous phosphorus by ordered polymeric structures for the manufacture of non-emissive fire retardant plastics
A novel plastic composition and method for making the same comprising a host polymer having substantially uniformly distributed therethrough a non-miscible liquid crystal polymer and red amorphous phosphorus. The liquid crystal polymer is present in a concentration sufficient to encapsulate said red amorphous phosphorus such that a substantial portion of the red amorphous phosphorus does not contact the host polymer
The invention relates to novel plastics and methods of making the same containing red amorphous phosphorus (RAP) as the fire retardant component. The novel compositions equal or exceed the fire retardant benefits of current day polymeric systems which incorporate RAP, yet do not emit phosphine gases at unacceptable toxic levels.
BACKGROUND INFORMATION
Many current day polymeric systems utilize RAP as a fire retardant additive. In some of the current day systems, particulate RAP is added to the polymeric system during the processing stage. Utilized in this manner, RAP has been an effective flame retardant for many thermoplastics and operates in both the vapor and condensed phases. For example, U.S. Pat. Nos. 4,105,735; 4,187,207; and 4,670,487.
In other systems, RAP is encapsulated in another polymer before introduction to the host polymer in hopes of reducing the emission of phosphorus gases. For example, U.S. Pat. No. 4,208,317 discloses encapsulating RAP in various polymers, none of which have the highly successful liquid crystalline structure of the liquid crystal polymer utilized in this invention. Other examples of RAP encapsulation are shown in U.S. Pat. Nos. 4,440,880 and 4,471,080, none of which have successfully decreased the phosphine emissions to acceptable, non-toxic levels.
While the benefits of RAP as a fire retardant additive in plastics are many as shown by the previously cited patents, RAPs' potential use is seriously compromised by its propensity to undergo hydrolysis followed by emission of the highly toxic gas phosphine (PH.sub.3). This emission of phosphine from materials comprised of a RAP containing polymer has far-reaching implications in terms of the future commercialization of any plastic product containing RAP. For example, many fire retardant products containing RAP are used in confined enclosures with limited ventilation, such as modern energy efficient buildings. The limited ventilation leads to accumulation of toxic levels of phosphine emitted from the enclosures.
To date, no RAP containing fire retardant plastic formulations or technologies exist which yield acceptable, non-toxic phosphine emission levels. Consequently, a need exists for a plastic formulation and technology that is capable of reducing phosphine emissions from RAP containing formulations to non-toxic levels while maintaining the fire retardant benefits.
SUMMARY OF THE INVENTION
In accordance with this invention, novel polymeric systems containing RAP and processes for making the same have been developed. The novel compositions, when incorporated in products such as electrical wire coatings, plastic wall units, etc., do not emit toxic levels of phosphine gas, yet maintain or exceed the fire retardant benefits of current day plastics containing RAP. In the disclosed novel approach, RAP is initially mixed with a liquid crystal polymer (LCP) which has a melt temperature approximately equal to RAP's auto ignition temperature. The mixture of RAP and LCP is then combined with a host polymer that is immiscible with the LCP.
Polarized-light photomicrographs of the novel plastic (FIG. 1A-1D) show the LCP encapsulates the RAP such that most of the RAP does not contact the host polymer. As shown in FIG. 1A, the encapsulated RAP is the dark brown dots within the yellow host polymer. The fire resistance of the novel composition exceeds or is comparable to the fire resistance of current day polymeric systems which contain RAP, yet the phosphine emissions from the novel compositions are dramatically lower than emissions from current day RAP containing plastics. Although not wanting to be limited to one theory, the encapsulation is believed to provide ultimate stability of the RAP against the onset of hydrolysis by exogenous water which would ordinarily yield the toxic gas phosphine.
BRIEF DESCRIPTION OF THE DRAWINGS
The file of this patent contains at least one photograph executed in color. Copies of this patent with color photographs will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.
FIGS. 1A-1D are Polarized-Light Photomicrographs of Thinly Sectioned (5 .mu.m) Non-Emissive Fire Retardant Plastic Comprising Encapsulated RAP (10% By Weight) in a Linear Low Density Polyethylene Polymer (LLDPE) made with a shear mixer.
FIG. 2 is a schematic of the preparation techniques for the RAP/LCP masterbatch.
FIG. 3 is a schematic of either the blending or extrusion preparation techniques for the final novel product that has less than about 50% LCP in the masterbatch.
FIGS. 4A-4F are a diagrammatic representation of the internal morphologies that are attainable by methods of the present invention for encapsulating RAP in a host polymer using either blending (FIGS. 4A-4C) or extrusion (FIGS. 4D-4F).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
To prepare the novel compositions, RAP is mixed with a LCP to form a homogenous mixture of up to about 70% by weight of RAP. Subsequently, dependant on the method of preparation chosen; i.e., blending or extrusion, a host polymer and the RAP/LCP mixture are combined. The host polymer should not be miscible with the LCP. In the final product, the LCP encapsulates the RAP such that a major portion, about 60% to about 100%, of the RAP does not contact the host polymer (see FIGS. 1A-1D). The novel final compositions contain from about 0.1% to about 20% by weight of RAP, the preferred range being about 4% to about 10% by weight; about 0.1% to about 15% of LCP, the preferred range being about 4% to about 10%; and about 65% to about 99.8% of host polymer, the preferred range being about 80% to about 90%.
The LCPs utilized in this invention may be selected from a variety of aromatic polyesters whose melt processing temperature is less than or slightly greater than either the auto ignition temperature of virgin RAP (255.degree. C.) or the auto ignition temperature of a synergist combination of RAP and an additive. For instance, a RAP and magnesium hydroxide blend has an effective auto ignition temperature greater than virgin RAP. Other synergist combinations include mixtures of RAP and aluminum trihydrate, antimony trioxide, zinc borates, molybdenum oxides, or fumed silica treated with an organo-silicon compound. The additives may also be added to the host polymer instead of to the RAP/LCP mixture.
If an additive is utilized, the novel final compositions contain from about 0.1% to about 20% by weight of RAP, the preferred range being about 4% to about 10% by weight; about 0.1% to about 15% of LCP, the preferred range being about 4% to about 10%; about 65% to about 99.8% of host polymer, the preferred range being about 80% to about 90%; and about 1% to about 50% by weight of additive, the preferred range being about 5% to about 20%.
LCPs meeting such a criterion include melt-orienting LCPs which are rigid, rod-like, and highly ordered molecules, both in the molten state, when directional flow is applied, and in the solid state. The mesophase state of suitable LCPs exhibit a multi-domain structure within which there is a high degree of nematic order; that is, a structural state of uniform orientation. Examples include (1) parallel offset copolyesters, the preferred being a parallel offset sold by Hoechst Celanese under the trade name Vectra; (2) copolyester-amides, with the preferred being sold by Hoechst Celanese under the trade name Vectra B-950; (3) rigid misfit copolyesters, the preferred being a rigid misfit copolyester sold by Amoco under the trade name Xydar SRT-300; and (4) bent misfit copolyesters, the preferred bent misfit being sold by Amoco under the trade name Xydar Low T. The preferred of all the available LCPs being the parallel offset copolyester available from Hoechst Celanese and sold under the trade name Vectra.
The parallel offset copolyesters are copolymers of 6-hydroxy-2-naphthalenecarboxylic acid and 4-hydroxybenzoic acid.
The copolyester-amides are copolymers of 1,4-Benzenedicarboxylic acid, aminophenol wherein the NH.sub.2 and OH substitution is not specified, and 6-hydroxy-2-naphthalenecarboxylic acid.
The rigid misfit copolyesters are copolymers 1,4,-Benzenedicarboxylic acid, [1,1'biphenyl]-4,4'-diol and 4-hydroxybenzoic acid.
The bent misfit copolyesters are copolymers of 1,4-Benzenedicarboxylic acid, 4-hydroxybenzoic acid, and 1,3-benzenediol.
The bent misfit and rigid misfit copolyesters of this invention are discussed and claimed in U.S. Pat. No. 3,637,595 which is incorporated herein by reference.
The invention employs the structural and processing characteristics of the LCP to take advantage of the fact that in the molten state, highly ordered domains of LCP are formed in regions of counter-current flow and in contact with a fixed geometrical structure. RAP particles within a polymer matrix undergoing elongational flow may be regarded as the immobile geometrical structure with which, at the microscopic level, highly ordered molecular alignment of the LCP occurs around the RAP's surface resulting in the encapsulation of RAP or the entrapment of RAP particles. This constitutes a possible theoretical premise for the present invention and is thought to generate an in situ encapsulation of RAP in the host polymer by the LCP.
The RAP/LCP mixture is generally prepared by masterbatching. FIG. 2 illustrates the various methods available for preparing the desired masterbatch using either blending or extrusion techniques.
If a shear blender is utilized, the chosen LCP is premelted and kneaded at its melt temperature. As discussed above, the chosen LCP generally has a melt processing temperature less than or slightly greater than either the autoignition temperature of virgin RAP (255.degree. C.) or the autoignition temperature of the synergist combination of RAP. After establishing minimum torque conditions of the free-flowing LCP, finely granulated RAP (5-50 micrometers in diameter) is slowly added to the LCP as it is continuously kneaded under a blanket of argon or nitrogen. Masterbatch compositions of up to about 70% by weight of RAP can be achieved via this method. The mixing of the LCP and RAP components in the described order are necessary to obviate the auto ignition of RAP. After achieving the desired percentage of RAP in LCP and establishing a homogeneous blend, the masterbatch of RAP and LCP is allowed to cool and solidify before removal from the shear mixer. The resultant state of aggregation of the RAP/LCP mixture can then be further processed into irregular crumbs, coarse powder or pellets.
If extrusion techniques are utilized in making the LCP/RAP mixture, a dry mixture of LCP, preferably in pellet form and preferably finely granulated RAP (5-50 micrometer diameter), is added to the extruder in the desired percentages. The RAP/LCP mixture is then extruded at sufficient RPM, from about 5 to about 45 rpm, and at a sufficient temperature from about 245.degree. C. to about 280.degree. C. under an argon or nitrogen blanket applied to the feed zone. The resultant RAP/LCP extrudate can then be pelletized. Again, compositions containing up to about 70% RAP are attainable.
The blender prepared or extrusion prepared RAP/LCP masterbatch, when solidified, are extremely stable, dustless materials that can be safely handled or transported. The masterbatch is typically transformed into a coarse powder, crumb or pellet, depending on the end-use application.
The phosphine emissions of the RAP/LCP masterbatches were compared to other polymer candidates that were considered as possible encapsulating polymers. The phosphine emissions from the RAP/LCP masterbatch of the present invention were exponentially lower than the other polymers considered. (See Example 2 and Table 1.)
After the RAP/LCP masterbatch has been prepared, it is then mixed with the host polymer to effect the final novel product. The host polymer may be selected from a wide variety of commercially available polymers such as polyolefins (e.g., polyethylene and polypropylene), polyethylene terephthalate, polystyrene, ethylene vinyl acetate, polycarbonate, polyurethanes, and epoxy resins, with the preferred being polyethylene and the primary criterion being that the host polymer is not readily miscible with the selected LCP.
FIG. 3 generally illustrates schematically the preparation of the novel final product. One alternative not illustrated is the occasion wherein a blender is utilized and the LCP content in the LCP/RAP mixture is greater than 50%. In this situation, the host polymer is preferably added in the molten state.
As depicted in FIG. 3, if crumbs or pellets of the masterbatch are used in conjunction with the sheer blender, the RAP/LCP masterbatch is added first to the blender and premelted. The host polymer is then blended with the premelted RAP/LCP masterbatch at a temperature equal to or slightly less than the melt temperature of the LCP. The resultant end product of the present invention has homogeneously dispersed particles of RAP encapsulated by highly oriented domains of LCP. (See FIGS. 1A-1D.)
If coarse powder of the masterbatch is used in conjunction with the shear blender, the host polymer is initially added to the shear blender and melted at a temperature equal to or slightly less than the melt temperature of the LCP. The coarse powder RAP/LCP masterbatch is then added to the blender and blended with the premelted host polymer at a temperature equal to or slightly less than the melt temperature of the LCP. The result in the end product has homogeneously dispersed particles of RAP encapsulated by highly oriented domains of LCP as reflected in FIGS. 1A-1D.
Alternatively, if extrusion techniques are utilized, a dry mixture of host polymer and crumb or pellet form of the RAP/LCP masterbatch is fed to the extruder. The mixture is extruded at about 245.degree. C. to about 280.degree. C., with the preferred being about 245.degree. C. to about 265.degree. C. at the feed zone to the die of the extruder device and at a shear rate ranging from about 5 to about 45 rpm while maintaining a nitrogen or argon blanket at the feed zone. Temperature and shear conditions are adjusted accordingly to sustain a minimum torque and pressure on the extruder device while yielding a homogenous extrudate having an internal structure consisting of highly oriented linear clusters of RAP encapsulated in elongated domains or fibrils of LCP as graphically depicted in FIGS. 4D-4F.
As stated above, and not shown in FIG. 3, if the RAP/LCP masterbatch contains about 50% or more LCP, the host polymer is added to the blender in the molten state. By adding the host polymer in the molten state, sufficient mixing is obtainable between the RAP/LCP masterbatch and the host polymer. Example 6 illustrates the use of the host polymer in the molten state in conjunction with sheer blending.
FIGS. 4A-4F schematically illustrates the differences between the final product of the present invention dependent on whether blending or extrusion techniques are utilized. As illustrated, the precise morphology of encapsulated RAP in the carrier plastic depends on the aggregate state of the LCP/RAP masterbatch and the technique used for preparing the final product. (See FIGS. 4A-4F)
The fire retardant capabilities of the final product of the present invention were compared to current-day polymers containing RAP which is not encapsulated. These tests showed that the novel plastic composition had comparable fire resistant qualities and in some instances exceeded the fire resistive qualities of the current day polymers containing RAP. (See Example 5.)
The novel compositions can be used to prepare electrical wire coatings, metal-plastic composite structural components for storage containers, and other packaging devices, wall units, and other products which require fire resistive characteristics.
EXAMPLE 1
A twin-head counter-rotating shear mixer commonly known to those skilled in the art of polymer blending was used to manufacture high-load masterbatches of RAP/LCP. The LCP Vectra A-950 (Hoechst Celanese) was pre-melted and kneaded at its melt temperature (280.degree. C.) by means of shear mixing. After establishing minimum torque conditions of the free-flowing LCP in the shear mixer, finely granulated RAP (5-50 .mu.m diameter) was slowly added to the mixer as its contents were continuously kneaded under a blanket of nitrogen. The rotational velocity and temperature of the shear mixer provided control over the torque imparted by the blend as additional amounts of RAP were added to the mixer. Masterbatch compositions of up to about 70% by weight of RAP were achieved. The mixing of the LCP and RAP components in the described order were necessary to obviate the auto-ignition of RAP. After achieving the desired percentage of RAP and establishing a homogenous blend, the masterbatch of RAP/LCP was allowed to cool and solidify for removal from the shear mixer. The resultant masterbatch product was further processed into irregular crumbs, coarse powder, or pellets which were dustless and safely transportable.
EXAMPLE 2
A counter-rotating twin screw extruder commonly known to those skilled in the art of plastic extrusion was used to manufacture an extrudate masterbatch of LCP/RAP.
A dry mixture of 90% by weight of LCP (Vectra A-950 available from Hoechst Celanese) in pellet form and 10% by weight of finely granulated RAP (5-50 .mu.m diameter) was added to the extruder. The RAP and LCP were extruded at 45 rpm and at a set temperature configuration of 245.degree.-255.degree.-265.degree.-250.degree. C. from the feed zone to the die of the extruder device with a nitrogen blanket applied to the feed zone. The resultant RAP/LCP extrudate was pelletized for subsequent mixing with a host polymer.
The resultant RAP/LCP pellets were tested against various other plastics containing RAP. Table 1 illustrates that the RAP/LCP masterbatch showed the lowest phosphine emissions after 24 hours.
TABLE 1
______________________________________
Performance Characteristics Of Candidate
Encapsulated RAP Systems
PH.sub.3 Emission After 24 h
(ppm/(mg RAP))
Material Process Encapsulated
Control.sup.1
______________________________________
Nylon 6,6 Interfacial 0.867 0.419
Polymerization.sup.2
Nylon 12 Interfacial 0.880 0.375
(methylene
Polymerization.sup.2
dianiline)
Cellulose Spinning Disk.sup.3
0.487 0.772
Triacetate
Barex 210 Cyclone Spray Dryer.sup.3
0.357 0.497
Parylene N
Vapor Deposition.sup.4
0.732 0.641
LCP (Vectra
Extrusion.sup.5
0.00349 0.500
A950)
______________________________________
.sup.1 Virgin RAP
.sup.2 Capsular
.sup.3 Microspherical
.sup.4 Conformal coating
.sup.5 Rod extrudate
EXAMPLE 3
A twin-head counter-rotating shear mixer was used to manufacture Applicants' novel non-emissive fire retardant LLDPE containing encapsulated RAP. A high load masterbatch comprising 70% RAP and 30% LCP by weight was prepared by the method described in Example 1. A 200 g aliquot of the finished masterbatch was introduced into the mixer in the form of irregular crumbs and subsequently melted under shear conditions, 35 rpm, at a temperature ranging from 270.degree. to 280.degree. C. An equivalent mass of host polymer (200g of pelletized LLDPE) was then added to this premelted masterbatch during shear mixing to make a 1:1 dilution of masterbatch in host polymer comprising 35% by weight of RAP. This precursory dilution was cooled and allowed to solidify immediately after achieving a homogenous blend.
A 91.4 g mass aliquot of the precursory dilution was remelted under shear conditions at a temperature of 165.degree. C. until well blended. Additional LLDPE (228.6 g) was then added to this precursory dilution while mixing to obtain the target percentage of RAP. Mixing was continued for approximately 15 minutes or until a homogenous blend was achieved, at which time the formulation was cooled and allowed to solidify for removal from the shear mixer. The resultant mixture was the novel composition comprising homogeneously dispersed particles of RAP bounded by highly oriented domains of LCP having a composition of 10% by weight RAP (fire retardant agent), 4.3% by weight LCP (encapsulant), and 85.7% by weight LLDPE (host polymer).
EXAMPLE 4
A twin head counter-rotating shear mixer was used to manufacture novel non-emissive fire retardant linear low density polyethylene (LLDPE). A high load masterbatch comprising 70% RAP and 30% LCP by weight was prepared by the method described in Example 1. A course powder of this masterbatch was obtained by frictional etching to yield a sufficient amount of masterbatch for blending with host polymer. The host polymer (274 g of LLDPE) was premelted under shear conditions at 140.degree. C. and 35 rpm. A 45.7 g aliquot of the powdered masterbatch was slowly added to this premelted host polymer during shear mixing, and the temperature of the mixer was immediately raised to 150.degree. C. Mixing was continued until a homogenous blend was achieved. The resultant mixture after solidification contained homogeneously dispersed particles of RAP which were discretely encapsulated by the LCP and whose composition was that which is described in Example 3.
Evidence for the morphological structure of the present example was obtained by cutting thin (5 .mu.m) sections of the resultant blend for observation by differential interference contrast (DIC); a variable light polarization microscopy technique useful in discriminating complex phases of solid materials. The DIC photomicrographs set forth in FIGS. 1A-1D show particles of RAP intimately surrounded by LCP and dispersed throughout the LLDPE constituting the bulk of the section. The LCP surrounding discrete RAP particles manifests itself by a change in the color contrast of the image, which is shown to occur only in the regions around the RAP particles.
EXAMPLE 5
The present example provides fire performance data relevant to the general methods and specific formulation blend previously disclosed in Example 3. A cone calorimeter, having been designed and constructed in accordance with the latest information available from the National Institute of Standards and Technology (NIST) and known to those skilled in the art of fire risk assessment, was used for performing the relevant aspects of ASTM Method E1354-92. This apparatus is used to determine the heat release rate of materials, one of the most important fire parameters for the assessment of fire hazard. Other parameters useful in the assessment of fire performance as evaluated on the cone calorimeter include time to ignition, rate of mass loss, smoke evolution, and effective heat of combustion.
The test method is intended to measure and describe the properties of materials in response to heat and flame under controlled laboratory conditions. The results are not intended to be used alone to describe or appraise the fire hazard or the fire risk of materials under actual fire conditions. However, the results of this test are provided in the present example as a key element to fire hazard assessment which as a whole takes into account all the factors that are pertinent to an assessment of fire hazard of a particular end use application.
Test specimens, each measuring 4.times.4.times.0.113 inches, were cut from a larger 17.times.19.times.0.113 inch coupon which had been heat and vacuum press-molded to size starting with irregular chips of the resultant blend described in Example 3. Control specimens consisted of unmodified LLDPE coupons of the same dimensions.
Specimen conditioning was in accordance with ASTM E1354. The coupons were tested in the horizontal orientation and exposed to a uniform heat flux of 20, 35 and 50 kW/m.sup.2. The tests were run until flameout occurred or for a maximum of 15 minutes. The test parameters which were measured in the present example and which are useful in assessing the performance of each specimen by the cone calorimeter test procedure include:
Time to ignition (time to 10 sec. sustained burning on the surface);
Heat release rate per unit surface area over time;
Peak heat release rate and corresponding time;
Total heat released by the specimen; and
Average effective heat of combustion.
Test results of these parameters are set forth in Table 2 below.
TABLE 2
__________________________________________________________________________
Summary of Results for Horizontal Heat Flux Exposures
(Control & FR Blend of Example 3)
Total
Heat
Release
Per Average
Time to
Heat Release
Unit Effective
Ignition/
Rate Surface
Heat of
Flame-Out
Peak At Time
Area Combustion
Heat Flux
Specimen
(s) (KW/m.sup.2)
(s) (MJ/m.sup.2)
(MJ/kg)
__________________________________________________________________________
20 Control
266/900
415.44
440 81.57
40.98
20 FR Blend
No Ignit.
3.88 155 1.02 15.07
35 Control
89/720
666.54
190 98.30
42.74
35 FR Blend
219/780
584.74
420 97.25
36.32
50 Control
53/652
969.02
125 84.36
37.35
50 FR Blend
83/555
782.10
200 102.32
34.51
__________________________________________________________________________
As the results in Table 2 illustrate, the time to ignition for this embodiment of the present invention is significantly delayed in contrast to the control specimen (i.e., equivalent host polymer, LLDPE, without fire-retardant agents) for all three horizontal heat flux conditions of the test. Moreover, ignition of the FR-blend was not observed at a heat flux of 20 kW/m.sup.2, whereas the corresponding control specimen ignited 266 s into the test. Based on this data, one can compute the critical ignition flux which is defined as that heat flux which is required to cause immediate ignition of the specimen material, by plotting the reciprocal of the time to ignition versus the incident heat flux. Through linear regression analysis of this plot, one can derive an equation to a line whose intercept at the abscissa is the critical ignition flux. These values were determined to be 12.6 kW/m.sup.2 and 26.7 kW/m.sup.2 for the control and FR-blend specimens, respectively, thus indicating that the incident heat flux required to ignite the FR-blend material of the present example is twice that of the control specimen. This compares favorably with critical ignition flux values which have been reported for halogen-based fire retardant polymers.
The heat liberating properties of the FR-blend during combustion (i.e., above the critical ignition flux) are shown to be significantly better than the control specimens in terms of both the peak rate of heat release and the average effective heat of combustion. Furthermore, taking into consideration the ratio of the time to ignition over the corresponding peak rate of heat release, one can arrive at the single most effective indicator of overall fire hazard that can be derived from these data. This parameter is proportional to the time to flashover, and hence high values indicate a lower fire hazard. The calculated values for the control specimens are 0.134 and 0.0547 s m.sup.2 /kW at heat fluxes of 35 and 50 kW/m.sup.2, respectively, as compared with 0.374 and 0.106 s m.sup.2/ kW, respectively, for the FR-blend of the present example. These values are again comparable to many halogen-based fire retardant polymers at equivalent incident heat flux conditions.
EXAMPLE 6
A twin-head counter-rotating shear mixer was used to manufacture non-emissive fire-retardant linear low density polyethylene (LLDPE). A high-load masterbatch comprising 50% RAP and 50% LCP by weight was prepared by the method described in Example 1. A 50 g aliquot of the finished masterbatch was introduced into the mixer in the form of irregular crumbs, and subsequently melted under shear conditions at 265.degree. C. with a nitrogen blanket applied to the feed zone of the mixer. The host polymer (200 g of LLDPE) was then added to this in the molten state and the mixture heated to 265.degree. C. while being sheared at 90 rpm. After several minutes of mixing at 90 rpm to ensure complete blending, the mixture was quickly cooled and removed from the mixing apparatus. The finished non-emissive fire-retardant LLDPE was consistent with the following composition:
10% by weight RAP (fire-retardant agent)
10% by weight LCP (encapsulant)
80% by weight LLDPE (host polymer)
EXAMPLE 7
A high-load masterbatch comprising 50% RAP and 50% LCP by weight was prepared by the method described in Example 1. A 62.5 g mass aliquot of the finished masterbatch was introduced into the mixer in the form of irregular crumbs, and subsequently melted under shear conditions at 265.degree. C. with a nitrogen blanket applied to the feed zone of the mixer. The host polymer (187.5 g of LLDPE) was then added to this in the form of solid pellets and the mixture heated to 265.degree. C. while being sheared at 90 rpm. After several minutes of mixing at 90 rpm to ensure complete blending, the mixture was quickly cooled and removed from the mixing apparatus. This precursory dilution (1:3 masterbatch/LLDPE) contained 31.25% by weight of RAP.
The target composition of masterbatch in host polymer was prepared from the precursory dilution to obtain the finished non-emissive fire-retardant LLDPE with a composition equal to that described in Example 6 above. For this, a 200 g mass aliquot of the precursory dilution was re-melted under shear conditions at a temperature of 165.degree. C. until well blended. The balance of LLDPE (50 g) was then added to this precursory dilution while mixing to obtain the target composition of RAP. Mixing was continued until a homogenous blend was achieved, at which time the formulation was cooled and allowed to solidify for removal from the shear mixture.
The fire performance characteristics of the embodiment of the present invention as determined by the cone calorimetry methods previously disclosed in Example 5 are set forth in Table 3. The data demonstrates how the composition of the present example affects the peak rate of heat release at a high incident heat flux (50 kW/m.sup.2), which is markedly lower than that measured for the composition of Example 3 (data shown in Example 5, Table 2).
TABLE 3
__________________________________________________________________________
Summary of Results for Horizontal Heat Flux Exposures
(FR-Blend of Example 7)
Total
Heat
Release
Per Average
Time to
Heat Release
Unit Effective
Ignition/
Rate Surface
Heat of
Flame-Out
Peak At Time
Area Combustion
Heat Flux
Specimen
(s) (kW/m.sup.2)
(s) (MJ/m.sup.2)
(MJ/kg)
__________________________________________________________________________
20 FR Blend
771/900
299.0
890 33.7 29.1
35 FR Blend
78/598
545.5
240 106.4
37.2
50 FR Blend
34/503
616.8
130 90.6 30.7
__________________________________________________________________________
EXAMPLE 8
This example demonstrates the effects of incorporating a synergist material into the host polymer of the embodiment previously described in Example 3 for the purpose of reducing the melt flow and flame-run properties that are characteristic of LLDPE while maintaining or improving the fire retardancy of the bulk material. A precursory dilution (1:1) of a high-load masterbatch (70% RAP;30% LCP) with LLDPE was prepared by the method described in Example 3. Again using a counter-rotating shear mixer, a 50 g mass aliquot of this precursory dilution was added to the mixer and subsequently melted under shear conditions, 15 rpm, at 180.degree. C. Approximately 62.5 g of LLDPE in the form of solid pellets were slowly added to this precursory dilution while mixing until a homogenous blend was achieved. While mixing at the said temperature and rate, 19.5 g of fumed silica (CAB-O-SIL.RTM. TS-720, Cabot Corporation) was added to the mixture. After achieving a homogenous blend, an additional 62.5 g of LLDPE (solid pellets) was added to this mixture while mixing at the said temperature and rate. Mixing was continued until a homogenous blend was achieved, at which time the formulation was cooled and allowed to solidify for removal from the shear mixer. The finished non-emissive fire-retardant and low melt-flow LLDPE was consistent with the following composition:
9% by weight RAP (fire-retardant agent)
4% by weight LCP (encapsulant)
77% by weight LLDPE (host polymer)
10% by weight fumed silica (synergist)
The fire performance characteristics of the embodiment of the present invention as determined by the cone calorimetry methods previously disclosed in Example 5 are set forth in Table 4. The data indicates a significant improvement in all calorimetric parameters, particularly the peak rates of heat release at high incident heat flux, as compared with non-synergist formulation previously taught in this disclosure.
TABLE 4
__________________________________________________________________________
Summary of Results for Horizontal Heat Flux Exposures
(FR-Blend of Example 8)
Total
Heat
Release
Per Average
Time to
Heat Release
Unit Effective
Ignition/
Rate Surface
Heat of
Flame-Out
Peak At Time
Area Combustion
Heat Flux
Specimen
(s) (kW/m.sup.2)
(s) (MJ/m.sup.2)
(MJ/kg)
__________________________________________________________________________
20 FR-Blend
447/900
179.1
490 55.7 36.8
35 FR-Blend
100/724
196.1
173 53.64
23.6
50 FR-Blend
42/513
237.4
110 49.0 20.2
__________________________________________________________________________
EXAMPLE 9
This example pertains to the manufacture of a non-emissive, fire-retardant extrudate of LLDPE using a counter-rotating twin screw extruder. A high-load masterbatch comprising 40 to 70% RAP and 60 to 30% LCP by weight, respectively, is prepared in pellet form by the method described in Example 2. A dry admixture of pelletized masterbatch and pelletized LLDPE is prepared at a proportion appropriate for the target composition of RAP; for example, one part of masterbatch to six parts of host polymer (LLDPE) by weight, and of quantity suitable for the desired application; for example, one kilogram of final product. The dry admixture is transferred to the hopper of the extruder apparatus, which is then extruded at a temperature configuration ranging from about 165.degree. C. to about 245.degree. C. at the feed zone to the die of the extruder device and at a shear rate ranging from about 5 to about 45 rpm while maintaining a nitrogen blanket at the feed zone. Temperature and shear conditions are adjusted accordingly to sustain a minimum torque and pressure on the extruder device.
The extrudate can be collected as a contiguous rod or pelletized for subsequent manipulation. In either case, the finished product is non-emissive, fire-retardant, and has an internal structure that consists of highly oriented, elongated domains or fibrils of LCP encapsulating linear clusters of RAP within the host polymer.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions, will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
[+/-] : Additive fire retardants, process for their preparation and polymeric compositions containing them
Novel fire retardant compounds are disclosed, which are poly-halogenated TMPI and MPI compounds containing three or more halogen atoms per molecule. A process for the preparation of these compounds and polymeric compositions containing them are also described
This invention refers to additive fire retardants, to processes for their preparation and to polymeric compositions containing them. More specifically, the additive fire retardants are halogenated derivatives of indan, and more specifically halogenated 1,1,3-trimethyl-3-phenyl indan (hereinafter briefly designated as TMPI) and halogenated 1-methyl-3-phenyl indan (hereinafter briefly designated as MPI). Said compounds are useful as fire retardants for a wide spectrum of resins, among them in particular ABS, polyamides, polyolefins, engineering thermoplastics, polyurethanes, and high impact polystyrene (HIPS), rubbers and thermosets. These flame retardants can also be used to produce flame retarded textiles.
BACKGROUND OF THE INVENTION
Fire retardation of polymeric compositions is a widespread requirement and a wide spectrum of fire retardants have been developed. A number of them are halogenated compounds. However fire retarded polymeric compositions, in particular those which contain halogenated fire retardants as additives, suffer from various deficiencies, in particular those due to thermal instability, to poor impact properties and to enhanced sensitivity to ultraviolet light irradiation.
It is a purpose of this invention to provide novel fire retardants which are free from these disadvantages, and in particular are thermally stable, impart good impact properties, and do not impart to polymeric compositions containing them higher sensitivity to ultraviolet irradiation.
It is another purpose of this invention to provide processes for the manufacture of said fire retardants.
It is a further purpose of this invention to provide polymeric compositions which contain said fire retardant as additives and have good mechanical properties, thermal stability and resistance to ultraviolet irradiation.
The fire retardants of this invention are additive fire retardants, and they are derivatives of phenyl indans, more specifically 1-methyl-3-phenyl indan (MPI) and 1,1,3-trimethyl-3-phenyl indan (TMPI). MPI can be obtained by condensing two molecules of styrene. It has been suggested as a starting material for the manufacture of anthraquinone (see Kirk-Othmer, Encyclopedia of Chemical Technology, vol. 3, p.705).
The preparation of TMPI by dimerization of alpha-methylstyrene is disclosed in DE 2,906,294. DE 2,659,597, U.S. Pat. No. 3,161,692 and Petropoulos and Fisher in J. Am. Chem. Soc., 80, 1938 (1958) relate to the dimerization of alpha-methylstyrene and/or ring alkylated alpha-methyl styrenes to yield the corresponding non-halogen containing TMPI compounds. EP 138766 gives an example of the dimerization of 4-chloro-alpha-methylstyrene to produce 6-chloro-1,3,3-trimethyl-1-(4'-chlorophenyl)indan. These products were used as heat transfer fluids and chemical intermediates for polymer manufacture.
U.S. Pat. No. 4,205,160 describes terpolymers of TMPI together with 2,4-diphenyl-4-methyl-2-pentene and 2,4-diphenyl-4-methyl-1-pentene. J. C. Wilson in the Journal of Polymer Science: Polymer Chemistry Edition 13, 749 (1975) describes various TMPI-based polyamides and polyesters. C. W. Paul et al describe in U.S. Pat. No. 4,988,785, resin compositions based on bisphenol compounds which are TMPI derivatives.
SUMMARY OF THE INVENTION
The fire retardant additives according to the invention are characterized in that they are poly-halogenated TMPI and MPI compounds containing three or more halogen atoms per molecule, or mixtures of such compounds.
A process for the preparation of the compounds according to the invention consists in the dimerization of one or more appropriately halogen substituted alpha-methyl styrene or halogen-substituted styrene compounds.
Another, preferred, process for the manufacture of the compounds according to the invention is the ring halogenation of TMPI or MPI.
Said ring halogenation is preferably carried out by reacting the TMPI or MPI substrate with an halogenating agent in an organic solvent in the presence of a catalyst.
The fire retarded polymeric compositions according to the invention comprise a polymeric base and from 0.1 to 60% and preferably from 1 to 40% by weight of a fire retardant additive according to the invention.
Other fire retardants may be added to the polymeric compositions. Among them may be mentioned, by way of example, halogenated or non-halogenated organo-phosphorus compounds, oxides, sulfides or organic salts of antimony, boron or arsenic, zinc borate, magnesium oxide and hydroxide, aluminum trihydrate, as well as other haloorganics, such as decabromodiphenylether, chlorinated polyethylene and chlorinated PVC.
Further, conventional additives may be added to the polymeric compositions according to the invention. These may comprise other fire retardants, antioxidants (such as Irganox), processing aids, (e.g. lubricants), impact modifiers, UV stabilizers (such as Tinuvins), fillers, fiber reinforcements, smoke suppressors and pigments.
DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 14 are HPLC chromatograms, TGA analysis graphs, IR spectra and .sup.1 H NMR spectra characterizing the examples of embodiments of the invention hereinafter described, as specified in each example.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In preparing the fire retardant additives according to the invention by ring halogenation of TMPI or MPI, the preferred halogenation agents are elemental halogens, in particularly bromine and chlorine, but other halogenation agents known in the art, such as bromates, HX (wherein X is Cl or Br) plus hydrogen peroxide etc., can be used. The halogenation is carried out in an organic solvent. The organic solvent medium should be substantially anhydrous and be inert or exhibit low reactivity towards the reactants. Organic solvents free of non-aromatic carbon-to-carbon unsaturation are preferred. Especially useful are halogenated, particularly chlorinated, saturated aliphatic hydrocarbons, such as carbon tetrachloride, chloroform, tetrachloroethane, methylene chloride, trichloroethane, dibromoethane, dibromethane (DBM), and the like. Acetic acid, chlorobenzene and acetonitrile can be used too. Particularly preferred is dibromomethane.
The molar ratio of the halogenating agent to the TMPI or MPI depends on the degree of halogenation desired. A slight excess over stoichiometric ratio is desirable.
The catalyst is preferably a metal or metal halide Lewis acid catalyst, that is capable of effecting the halogenation on the aromatic ring. Examples are the bromides and chlorides of aluminum and iron and mixtures thereof. Specific examples are AlCl.sub.3, AlBr.sub.3, FeBr.sub.3, SbCl.sub.3, SbCl.sub.5, SbClBr.sub.4, TiCl.sub.4, SnCl.sub.2, SnCl.sub.4, BeCl.sub.2, CdCl.sub.2, ZnCl.sub.2, BF.sub.3,BBr.sub.3,BCl.sub.3,ZrCl.sub.4. Iodine can also be used. The most preferred catalyst is Fe. The catalysts are used in amounts of at least 1% by weight, based on the weight of indan. Amounts of about 5-10% are preferred. The halogenation is carried out at temperatures comprised between 15.degree. and 100.degree. C., and preferably between 50.degree. and 70.degree. C.
The ring halogenation of TMPI and MPI will generally produce a mixture of compounds having different halogenation degrees, but this is not a drawback because all those compounds are suitable as fire retardant additives. Therefore, when reference is made in this specification to compounds according to the invention, mixtures of such compounds are intended to be included.
The dimerization of styrene derivatives will generally yield a given compound: thus the dimerization of 3,5-dibromo-alpha-methylstyrene will produce 5,7-dibromo-1,3,3-trimethyl-1-(3',5'-dibromophenyl)indan exclusively. The dimerization can be carried out for example as disclosed in EPA 138,766, in the article by L. M. Adams, R. J. Lee and F. T. Wadsworth, J. Org. Chem., 24, 1186 (1959) and in the article by Petropoulos and Fisher hereinbefore cited. However, not all such styrene derivatives are adapted for dimerization, but only those in which at least one ortho position in respect to the alkylene group is free for cyclization to occur.
The fire retardant compounds according to the invention are added to thermoplastic polymers to produce fire retarded polymer compositions by mixing, usually at high temperature, with the polymer. The mixing technique is conventional and can be carried out in conventional equipment without any particular difficulties, especially since the fire retardants according to the invention are highly thermally stable. It is also possible to produce a masterbatch concentrate containing more than 30% of the fire retardant according to the invention, and in some cases synergists; this masterbatch can be diluted in the final resin compositions. When the polymer is a polyurethane, the fire retardants are added to one of its components.
The ring halogenation of TMPI produces compounds having the following general formula I (wherein X is Br or Cl): ##STR1##
Similarly, the ring halogenation of MPI produces compounds having the general formula II: ##STR2##
The degree of halogenation is expressed by the sum: m+n. It is controlled by the molar ratio between the halogenating agent and the TMPI or MPI substrate. It also depends on the concentration (dilution) of the reagents, the temperature and the time of the reaction, and the strength of the catalyst.
TMPI and MPI substituted by three or more halogen atoms are novel compounds. TMPI substituted by two chlorine atoms has been described, as mentioned hereinbefore, in EP 138,766, but its use as fire retardant has not been suggested.
The fire retardant compounds according to the invention not only impart fire retardancy to the polymeric compositions which contain them, but they provide good physico-mechanical properties and resistance to degradation of the products containing them under UV radiation. This latter is a particular surprising feature, since compounds containing high concentrations of halogens, particularly bromine, in their structure, usually promote UV-degradation. Further, the unexpected high thermal stability of the compounds according to the invention makes them particularly suitable for application in engineering thermoplastics.
The unexpected high solubility of the compounds according to the invention (12% in toluene at 100.degree. C.) provides a further advantage of the invention: the reactor and processing utilities can be cleaned of them easily.
A number of embodiments of the invention will now be described.
EXAMPLE 1
Preparation of Partially Brominated TMPI
Into a 3-necked flask (250 ml) equipped with a mechanical stirrer, a reflux condenser and a thermocouple, were added Br.sub.2 (35 g; 0.22 mol, 5.5 molar fold over TMPI); Fe (0.75 g; 13.4 mmol) and DBM (100 g). A solution of TMPI (9.45 g, 40 mmol) in DBM (30 g) was added dropwise to the stirred suspension at 35.degree.-65.degree. C. during 2 hrs (the released HBr was trapped in aqueous NaOH). When the reflux of Br.sub.2 ceased, water was added to the reaction flask, and the aqueous phase was removed. Then, a solution of Na.sub.2 S.sub.2 O.sub.5 was added to neutralize the residual Br.sub.2, and the aqueous phase was removed. Next, water was added again to wash the organic phase, and the aqueous phase was removed. The organic phase was filtered, and the solvent was evaporated. The residue (25 g) solidified. Elementary analysis: found for Br 63.9% (calculated for C.sub.18 H.sub.16 Br.sub.5 63.2). The residue consisted of several compounds. The HPLC chromatogram (FIG. 1) showed 3 major peaks.
The TGA (FIG. 2) analysis showed a weight loss of 5% at 257.degree. C., 10% at 297.degree. C. and a major peak at 371.degree. C.
IR (FIG. 3; cm.sup.-1): 3420, 2960, 2920, 2840, 1780, 1590, 1520, 1450, 1370, 1310, 1270, 1110, 1020, 875, 820, 785, 740.
.sup.1 H NMR (FIG. 4; .delta., in TCE): the spectrum is very complex due to the presence of many isomers in the sample (HPLC spectrum). Three main groups of chemical shifts are characteristic of halogenated TMPI: aromatic hydrogens observed as different singlets (between .delta. 7 and 8 ppm); the methylenic hydrogens of the cyclopentane ring of the indan observed as AB quartets between .delta. 2 and 3 ppm; and the methyl groups appearing as sharp peaks between .delta. 1 and 2 ppm.
EXAMPLE 2
Preparation of Partially Chlorinated TMPI
Into a 3-necked flask (250 ml) equipped with a mechanical stirrer, a reflux condenser and a thermocouple, were added AlCl.sub.3 (5.6 g; 42 mmol), CCl.sub.4 (130 ml) and TMPI (19.8 g, 84 mmol). Cl.sub.2 (30 g; 422 mmol; 5 molar fold over TMPI) was passed into the stirred solution through a dip-tube (3.5 hrs) at a rate which maintained the reaction temperature of 35.degree.-38.degree. C. (cooling of the reaction mixture with a water bath if necessary). The reflux condenser was cooled to -20.degree. C. (ethylene glycol) in order to avoid losses of Cl.sub.2 with the evolution of HCl (the released HCl was trapped in aqueous NaOH). Thirty minutes after the addition of all the Cl.sub.2, the evolution of HCl ceased. The reaction mixture was heated to 50.degree. C., and held at that temperature for 30 min. more. The reaction mixture was washed with water (100 ml). Then, a solution of Na.sub.2 S.sub.2 O.sub.5 was added to neutralize the residue of Cl.sub.2, and the aqueous phase was removed. Water was added again to wash the organic phase, and the aqueous phase was removed. The organic phase was treated with active carbon, filtered and the solvent was evaporated. A brown oily layer was obtained (23.5 g). Elementary analysis found: C 52.1; H 4.2 and Cl 42.3% (for comparison purposes only, the values calculated for C.sub.18 H.sub.16 Cl.sub.5 are: C 52.8; H 3.9; Cl 43.3%).
The GC/MS (FIGS. 5 & 6) spectrum reveals many peaks which were attributed to different isomers of partially chlorinated TMPIs: peaks between r.t. of 12.25 to 17.14 min. were identified (% area) as one trichlorinated isomer (3.1%; Mw 338), seven tetrachlorinated isomers (with a total of 50.3%; Mw 372) and eight pentachlorinated isomers (with a total of 37.4%; Mw 406). Small peaks (the remaining 10%; area %) are observed at r.t. 17.5-22. min. and are assigned to hexa- hepta and octa- isomers (i.e. the peak 19.5 min. was identified as a hexachlorinated TMPI, Mw 440). TGA (FIG. 7): 5% at 122.degree. C., 10% at 166.degree. C. and a major peak at 315.degree. C.
IR (FIG. 8; cm.sup.-1): 2960, 2920, 2840, 1580, 1560, 1460, 1380, 1360, 1310, 1270, 890, 785, 760.
.sup.1 H NMR (FIG. 9; .delta., in CDCl.sub.3); the spectrum is very complex due to the presence of many isomers in the sample (GC/MS analysis). Three main groups of chemical shifts are characteristic of a halogenated TMPI: aromatic hydrogens observed as different singlets (between .delta. 7 and 8 ppm); the methylenic hydrogens of the cyclopentane ring of the indan observed as AB quartets between .delta. 2 and 3 pm; and the methyl groups appearing as sharp peaks between .delta. 1 and 2 ppm.
The HPLC chromatogram is shown in FIG. 10.
EXAMPLE 3
Preparation of Octabromotrimethylphenyl Indan (OBTMPI) ##STR3##
This preparation is carried out in two cycles.
First Cycle:
Into a 3-necked flask (5 liter) equipped with a mechanical stirrer, a reflux condenser and a thermocouple, were added Br.sub.2 (1619 g; 10.1 mol); Fe (7.7 g; 0.14 mol) and dibromomethane (DBM, 2938 g; 1906 ml). A solution of TMPI in DBM �9.5% of 2732 g; (259.6 g TMPI; 1.1 mol)!, was added dropwise to the stirred suspension at 25.degree.-40.degree. C., during 3.5 hrs, (the released HBr was trapped in aqueous NaOH). Mixing was continued for another 2.5 hrs at 40.degree.-75.degree. C. Another portion of Fe (4.4 g; 78.7 mmol) was added to the reaction mixture one hour before the end of the reaction. Water was added, to wash out the iron salts. The aqueous phase was removed. The organic layer was treated with aq. Na.sub.2 S.sub.2 O.sub.5, filtered, washed with water, neutralized with Na.sub.2 CO.sub.3 solution, washed again with water, with 800 ml acetone and then dried. An off-white solid (500 g) was obtained. The DBM layer, dried with anhydrous Na.sub.2 SO.sub.4, was kept for the next cycle (4997 g. containing 6.7% solid).
Crystallization
The product (500 g) was dissolved in hot toluene (2250 ml), treated with active carbon (10 g) and cooled. The precipitate (after cooling) was filtered, washed with acetone and dried. A slightly yellow solid was isolated (352 g), m.p. 248.6.degree. C. Elementary analysis calculated for C.sub.18 H.sub.12 Br.sub.8 : C 24.9; H 1.4; Br 73.7%. Found: C 25.6; H 1.3; Br 73.0%. TGA (FIG. 11) 1/5%=296.degree./346.degree. C., 10% =365.degree. C. and the major peak at 426.degree. C. HPLC (FIG. 12): 3 peaks at 24.4, 26.5 and 28 min. with 3.7, 5.4 and 90.6% ratio, respectively. The major peak is assigned to the octabromo-derivative. IR (FIG. 13; KBr; cm.sup.-1): 3440, 2960, 2920, 2880, 1630, 1600, 1480, 1430, 1380, 1360, 1320, 1300, 1220, 1190, 1170, 1120, 1000, 955, 905, 850, 800, 750, 700. .sup.1 H NMR (FIG. 14; TCE; .delta.): 1.50 ppm (CH.sub.3 ; s; 3H); 1.57 ppm (CH.sub.3 ; s; 3H); 1.78 ppm (CH.sub.3 ; s; 3H); AB quartet centered at 2.27 ppm (CH.sub.2, 2H); 7.74 ppm (aromatic, s, 1H).
The concentration of the mother liquor afforded another 109 g of material of similar properties. Evaporation of the solvent to dryness left 20 g of solid.
Second Cycle
The same procedure as above was carried out.
Materials used: the mother liquor from the previous run (4900 g; containing 328 g of solids); Br.sub.2 (1664 g; 10.4 mol); Fe (7.7 g; 138 mmol); A solution of TMPI (260 g 1.1 mol) in DBM (840 g).
The TMPI solution was added dropwise during 2 hours at 28.degree.-43.degree. C. Mixing was continued (43.degree.-78.degree. C.) for 3 hours more. After 4.5 hrs (from the start) Fe (4.4 g; 78.8 mmol) was added and 30 min. later Br.sub.2 (10 ml) was added. The reaction was stopped when the evolution of HBr ceased (after a total of 5.5 hours).
The work-up was carried out as in the first cycle. A yellowish solid (880 g; 92.5% yield) was obtained. TGA: 1/5%=271.degree./338.degree. C., 10%=363.degree. C. and a major peak at 436.degree. C. HPLC: 3 peaks at 23.9, 26 and 27.4 min. with a ratio of 3.8, 6.4 and 89.3%, respectively.
Crystallization
The above solid (855 g) was dissolved in hot toluene (reflux; 18% concentration, 4.7 liters) and 13 g of active charcoal were added. The precipitate was washed with toluene and with acetone. The dry solid (590 g) was obtained in 69% yield; m.p. 248.6.degree. C. TGA: 1/5%=294.degree./348.degree. C., 10%=370.degree. C. and the major peak at 437.degree. C. HPLC: 3 peaks at 24.6, 26.8 and 28.3 min. with a ratio of 2.7, 5.2 and 91.8%, respectively. Elementary analysis, calculated for C.sub.18 H.sub.12 Br.sub.8 : C 24.9; H 1.4; Br 73.7%. Found: C 25.7; H 1.4; Br 73.2%.
Concentration of the mother liquor to 20% of its weight afforded a second crop of a solid of similar properties after washing with toluene and acetone and drying (190 g; 22% yield). TGA: 1/5%=302.degree./346.degree. C., 10%=365.degree. C. and a major peak at 423.degree. C. HPLC: 3 peaks at 24.3, 26.5 and 28 min. with a ratio of 3.6, 7.0 and 89.1%, respectively. Elementary analysis, found: C 25.4; H 1.2; Br 73.1%.
EXAMPLE 4
Preparation of Partially Brominated 1-Methyl-3-Phenylindan (MPI)
Following the procedure used in Example 1, 20.8 g. (0.1 mole) of MPI was brominated with 88 g. (0.55 mole) of bromine in a total 200 g DBM as solvent, using 1.5 g. Fe as catalyst. The isolated product (55 g.) contained 65.2% Br (calculated for C.sub.16 H.sub.11 Br.sub.5, 66.3% Br).
EXAMPLE 5
Preparation of a Fire-Retarded Polyester
To 15 g of a liquid polyester (410 brand, Fiberplast Ltd.) there were added OBTMPI (73.1% Br; 1.1 g), twelve drops of a 7% cobalt octoate solution and 3 drops of methyl ethyl ketone peroxide at ambient temperature with mixing. The mixture was quickly cast into a Teflon mould containing cavities of dimensions 6.times.100.times.3 mm. Curing was performed at ambient temperature for 24 hrs and then in an oven at 100.degree. C. for 2 hrs. The specimens were removed and left to cool and the LOI (Limiting Oxygen Index) was measured and compared with that of an identically prepared sample not containing the fire retardant compound. The LOI of the control specimen was 17.5 LOI for 5% loading (only 3.6% Br) was 19.6.
EXAMPLE 6
Application Tests With Several Thermoplastic Resins
Several resins were compounded with OBTMPI as fire retardant. The formulations (Table 1-3) were prepared in a Brabender Plasticorder, and samples for the evaluation of product performance were molded at temperatures appropriate for each resin.
The compounding and press temperatures were as follows:
______________________________________
Temperature of
Resin Table Compounding
Molding
______________________________________
ABS 1 220.degree. C.
200.degree. C.
Polyamide 2 260 250
Polypropylene
3 230 200
HIPS 4 230 200
______________________________________
The flammability and mechanical properties obtained are recorded in the tables. Their definition is as follows:
Flammability:
UL-94 vertical burning test in a flammability hood (according to UL); Limiting oxygen index (LOI) (ASTM D 2863-77) on a FTA Flammability Unit Stanton Redcroft.
Izod Notched Impact Energy:
(ASTM D 256-81) on a Pendulum impact tester type 5102 Zwick.
HDT:
Deflection temperature under flexural load (18.5 kg/cm.sup.2) (ASTM D 648-72) on a CEAST 6055.
U.V. Stability:
Accelerated weathering test-irradiation for 250 hrs and measuring of the color change by color deviation, on an Accelerated Weathering Tester Q-U-V (B-lamps), (The Q-Panel Co.).
Color Deviation:
Color measurement and comparison with reference specimen, on a Spectro Color Meter SCM-90, (Techno-Instruments Ltd.).
TABLE 1
______________________________________
COMPARISON BETWEEN OBTMPI AND
OCTABROMODIPHENYL ETHER (OCTA) IN ABS
______________________________________
COMPONENTS
ABS NOVODUR P2H AT (BAYER)
75.3 75.7
OBTMPI 15.8
OCTA 15.4
ANTIMONY TRIOXIDE 7.7 7.7
ADDITIVES 1.2 1.2
PROPERTIES
BROMINE CONTENT % 12 12
FLAMMABILITY-UL94 VO VO
(1.6 mm)
UV STABILITY-QUV 41 44
(250 H), DE
HDT (264 psi), C 84 81
______________________________________
TABLE 2
______________________________________
USE OF OBTMPI IN NYLON 6
______________________________________
COMPONENTS %
NYLON 6 CAPRON 8022HS (ALLIED)
72.6
OBTMPI 19.2
ANTIMONY TRIOXIDE 6.8
HOSTAFLON TF 3202 (HOECHST)
1
AC-400A (ALLIED) 0.4
PROPERTIES
BROMINE CONTENT % 15
FLAMMABILITY-UL94 VO
(1.6 mm)
IZOD NOTCHED IMPACT, J/m
49
HDT (264 psi), C 51
______________________________________
TABLE 3
______________________________________
COMPARISON BETWEEN OBTMPI AND
DECABROMODIPHENYL ETHER (DECA) IN HIPS
______________________________________
COMPONENTS %
HIPS VESTYRON 638 (HUELS)
81.9 83
OBTMPI 13.2
DECA 12.2
ANTIMONY TRIOXIDE 3.8 3.7
ADDITIVES 1.1 1.1
PROPERTIES
BROMINE CONTENT, % 10 10
FLAMMABILITY-UL94 VO VO
(3.2 mm)
IZOD NOTCHED IMPACT, J/m
52 48
UN STABILITY-QUV 51 60
(250 H) YELLOWNESS INDEX
______________________________________
EXAMPLE 7
Application of Brominated Methylphenylindans As Fire Retardants in Polyurethanes
The products of Examples 2 and 3 were incorporated into polyurethane foams in the following manner.
A sorbitol-based polyether polyol having an hydroxyl number of 490 mg KOH/g served in two parallel application tests. In each of the tests, 1.38 g of the polyol was mixed with 11 g of the products of Examples 2 and 3, 15.8 g of Santicizer 141 (an alkyl-aryl phosphate produced by Monsanto), 0.25 g water, 1.0 g of a silicone surfactant and 1.0 g of dimethylcyclohexylamine as catalyst. When homogeneity was observed, 15.0 g of Freon 11 were added to each mixture, which were then stirred vigorously for 45 seconds. Diphenylmethane diisocyanate (MDI, 51.2 g) was then added to each and stirring was continued for 5 seconds more. The mixtures were poured into cardboard boxes lined with wrapping paper and left to rise freely. The cream times (measured from the moment of MDI introduction) were 31 and 40 seconds, respectively, whereas the rise times were 282 and 253 seconds, respectively. The foams obtained had Limiting Oxygen Indexes of 23.3 and 23.5 versus 18.6 for the blank foam, i.e. containing no fire retardant.
EXAMPLE 8
Preparation of an Epoxy Specimen (In a 1:1 Base:Hardener Epoxy)
To 15 g of a liquid resin (Araldite-rapid; Ciba-Geigy, Nr. 92.7521) there were added the halogenated TMPI (see table), 15 g of liquid hardener (Araldite-rapid Ciba-Geigy, Nr. 92.7522) at ambient temperature with mixing. The mixture was quickly cast into a Teflon mould containing cavities of dimensions 6.times.100.times.3 mm. Curing was performed at ambient temperature for 30 min. and then in an oven at 100.degree. C. for 2 hrs. The specimens were removed and left to cool and the LOI (Limiting Oxygen Index) was measured and compared with that of an identically prepared sample not containing the fire retardant compound. The LOI of the control specimen and of the specimens containing the halogenated compound are given below:
______________________________________
Composition of specimen
% Hal. Base:hardener:sample
% Hal.
in FR (g):(g):(g) in specimen
LOI
______________________________________
blank 15:15:0 0 19.4
73.1 Br 15:15:4.74 10 22.9
73.1 Br 15:15:2.37 5 21.4
42.9 Cl 15:15:4.55 10 20.7
blank 10:20:0 0 17.9
42.9 Cl 10:20:4.55 10 20.6
42.9 Cl 10:20:9.1 20 22.8
______________________________________
A number of embodiments of the invention have been described, but it will be understood that the invention can be carried out with many variations, adaptations and modifications, by persons skilled in the art, without departing from its spirit or exceeding the scope of the claims.
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
[+/-] : Flame-retarded HIPS formulations with enhanced impact strength
The impact strength of articles made from a flame-retarded formulated HIPS resin containing an impact modifier is increased by forming a concentrate or masterbatch containing the flame retardant and impact modifier, blending the concentrate with HIPS resin, and extruding the resultant blend
HIPS resins are well known in the synthetic organic polymer art as a class of thermoplastics which offers excellent mechanical properties as well as good chemical resistance. The general characteristics of HIPS resins are described, for example, in "Modern Plastics Encyclopedia," McGraw-Hill, New York, N.Y., 1990, p 96. HIPS resins are "rubber-modified" copolymers or homopolymers of styrenic compounds. They are known for their ease of processing, good dimensional stability, impact strength, and rigidity. They generally are prepared by dissolving an elastomer in a styrenic monomer before polymerization of the latter, but the elastomer can also be incorporated in other ways.
For purposes of the instant invention, a HIPS resin is a thermoplastic which can be a homopolymer or random or block copolymer produced by polymerizing one or more vinyl aromatic monomers such as styrene, alkyl-substituted styrenes, halo-substituted styrenes, or alpha-alkyl styrenes or substituted styrenes, in the presence of an elastomer monomer or polymer, such as polybutadiene, for example. Further, a formulated HIPS resin, for all purposes herein, comprises at least about 50 wt % HIPS resin. The remainder of the formulated HIPS resin comprises various monomeric or polymeric additives which modify the properties of the HIPS resin. These additives include, for example, various impact modifiers, stabilizers, processing aids, pigments, flame retardants, synergists, etc. Such additional additives can be incorporated into the HIPS resin in various ways.
Incorporation of the various additives is not a trivial matter, and the properties of articles made from the formulated HIPS resin can be affected by the manner in which it is done. When the additives are solids, dry-blending can be employed. For example, the solids can be mixed and heated to soften and homogenize the mass, which can then be sheeted, chopped, and pelletized.
A flame retardant, such as a halogenated organic compound, is often incorporated into a formulated HIPS resin so as to constitute as much as about 20-25 wt % of the formulation. Such incorporation can adversely affect the properties, other than the flammability, of the formulated HIPS resin. For example, a flame retardant having a high melting point range, such as decabromodiphenylethane, or decabromodiphenyl oxide will have a filler type effect on the HIPS resin formulation, whereas a flame retardant having a lower melting point range will have a plasticizer effect on the formulation. Because of the effect flame retardants have on articles containing such HIPS resin formulations, improvements in such formulations and formulation techniques are highly desirable and of significant commercial importance.
SUMMARY OF THE INVENTION
Consequently, it is an object of this invention to provide a formulated HIPS resin in which a halogenated organic flame retardant is incorporated in such a way as to provide a significant net increase in the impact strength of articles prepared from the HIPS resin formulation. Other objects will become apparent hereinafter.
In attaining the aforesaid objectives, this invention provides a flame-retarded HIPS formulation which comprises at least about 65 wt % HIPS resin, about 5-25 wt % halogenated flame retardant, about 1-12 wt % polymeric impact modifier, and optionally, about 0-6 wt % flame retardant synergist. The flame retardant is incorporated in the flame-retarded HIPS formulation by forming a concentrate or masterbatch containing the flame retardant, impact modifier, and optionally, other additives; blending the concentrate with the HIPS resin; and extruding the resultant blend thereby forming a formulated HIPS resin which will provide enhanced IZOD impact strength as determined by ASTM D 256-88 to articles made from the HIPS resin formulation. It has been found surprisingly, and quite unexpectedly, that the IZOD impact strength of articles containing the HIPS resin formulation of this invention when prepared according to the method described herein is dramatically increased over articles prepared from a HIPS formulation in which the flame retardant, impact modifier, HIPS resin, and optional flame retardant synergist are combined without initially forming a concentrate or masterbatch of flame retardant and impact modifier.
For the purposes of this invention, the terms "concentrate", "masterbatch", and "masterbatching" refer to a homogeneous blend comprising flame retardant and impact modifier, and optionally, other additives, provided the other additives do not adversely affect the IZOD impact strength of articles prepared from the formulated HIPS resin. It is of course understood, that such a concentrate or masterbatch may also contain a minor amount of HIPS resin sufficient to provide a homogeneous blend of the masterbatch components.
DETAILED DESCRIPTION
The HIPS resin component of the formulated HIPS can be selected from the many resins available in commerce. Such resins include the Dow Styron.RTM. resins, for example, which are styrene/butadiene copolymers. The HIPS resin component of the formulated HIPS resin of this invention comprises at least about 65 wt % of the formulation, and the HIPS resin can comprise as much as about 85 wt % of the formulation.
One of the additives which will be present in the formulated HIPS resin of this invention is one or more flame retardants, and halogenated flame retardants have been recommended and employed in that application. Halogenated flame retardants especially useful in the practice of this invention are selected from the group consisting of tetrahalobisphenol A, N,N'-bis(tetrahalophthalimide), N,N'-ethylenebis(tetrahalophthalimide), halogenated polystyrene, and pentahalobenzyl acrylate, in all of which halo is selected from chloro and bromo, and also bis-halophenyl compounds represented by the following structural formula which are solids at ambient temperature: ##STR1## in which formula each X is selected independently from chlorine and bromine; m and n can be the same or different and can range from 1 to 5; Y is selected from oxygen, alkylene, --NR-- (where R is selected from hydrogen and hydrocarbyl), alkylenedioxy, aryldioxy, and a chemical bond. Alkylene is preferably lower alkylene, i.e., straight chain or branched C.sub.1 -C.sub.6, such as methylene, ethylene, isopropylene, butylene, t-butylene, and the like, methylene or ethylene being preferred. Hydrocarbyl includes alkylene, especially lower alkylene, but also unsaturated alkylene and aromatic groups such as phenyl and alkylphenyl or halophenyl. Alkylenedioxy includes methylenedioxy, 1,2-dioxyethylene, and the like, while aryldioxy includes dioxyphenyl, for example. In the preferred flame retardants halo and X are bromo. Among the aforesaid flame retardants the bis-halophenyl compounds are preferred, and among these compounds, decabromodiphenyl oxide, decabromodiphenyl ethane, 1,2-bis(tri-bromophenoxy)ethane, and decabromodiphenyl amine are especially attractive.
In addition to the halogenated flame retardant, the formulated HIPS resin of this invention optionally includes one or more flame retardant synergist in an amount ranging from about 2 to about 6 wt %. A number of materials, such as metal oxides, e.g., iron oxide, tin oxide, zinc oxide, aluminum trioxide, alumina, antimony tri- and pentoxide, and boron compounds, e.g., zinc borate; also antimony silicates and ferrocene, are known to enhance the effectiveness of flame retardants, especially halogenated flame retardants. A particularly effective and preferred synergist is antimony trioxide. The flame retardant synergist can be combined with the flame retardant and impact modifier in the concentrate or masterbatch, or the synergist can be admixed with the HIPS resin component of the formulation.
In addition to flame retardant, the formulated HIPS resin of this invention includes one or more polymeric impact modifiers. It is well known that the addition of certain materials to a HIPS resin tends to toughen articles molded therefrom. Among these materials are styrene/butadiene/styrene triblock copolymer, styrene/isoprene/styrene triblock copolymer, styrene/butadiene diblock copolymer, polycaprolactone, and functionalized ethylene/propylene copolymers. Among these impact modifiers, a styrene/butadiene/styrene triblock copolymer is especially effective.
The concentrate or masterbatch of this invention can be formed by conventional techniques such as by combining, either continuously or batchwise, the flame retardant, impact modifier, and optional additives in a stirred kettle, drum mixer, mixing tube, mechanical high-intensity mixer, kneader, or extruder whereby a homogeneous blend of the concentrate or masterbatch is obtained. It will of course be recognized that only those innocuous ingredients which do not adversely affect the IZOD impact strength of articles made from the fully formulated HIPS resin will be included in the concentrate or masterbatch. Such a determination can be made empirically by simple trial and error techniques. Accordingly, the optional additives may be selected from pigments, flame retardant synergists, thermal stabilizers, plasticizers, antistatic agents, ultraviolet stabilizers, blowing agents, fillers, reinforcing rubbers, and the like.
The temperature for forming the concentrate or masterbatch of this invention is not critical, provided the temperature is low enough to avoid thermal degradation of the concentrate, yet high enough to provide a homogeneous blend of the concentrate's components. Those skilled in the art can readily determine suitable processing temperatures.
After forming the concentrate or masterbatch, the concentrate is combined with the HIPS resin to form the flame retardant HIPS formulation. Such a combination can be obtained by the use of a single or twin screw extruder, a high intensity mixer, or a continuous mixer. It is understood of course, that when an extruder is used, the concentrate and the HIPS resin may be combined and fed to the extruder, or the concentrate and HIPS resin may be fed to the extruder separately.
A typical flame-retarded formulated HIPS resin of this invention, which contains brominated flame retardant, and a polymeric impact modifier, in addition to the HIPS resin, is described in the Example.
EXAMPLE
A. The components indicated in column A, Table 1 were dry-blended by shaking them together for about 2 min in a plastic bag. The mixture was then extruded on a Haake-Buchler System 40 Rheometer equipped with a twin-screw extruder head. The extrusion was carried out at 175.degree.-190.degree.-215.degree.-215.degree. C. and 65 rpm. The extruded material was cooled in an ice bath, and then pelletized. The pellets were then injection molded into 1/8" test bars on a Battenfeld BSKM 100/40 machine at 216.degree. C. and tested for IZOD impact strength according to ASTM D 256-88. This Example A is not within the scope of this invention.
B. The components indicated in column B, Table 1 were combined as follows: The flame retardant, impact modifier, and processing aid were blended in a Brabender mixer at 175.degree. C. and 66 rpm for 2 min. The resultant blend was sheeted on a two-roll mill and chopped into small pieces in an Osterizer mixer, affording a masterbatch. An amount of the masterbatch appropriate to the desired composition was dry-blended with the remaining ingredients, i.e., HIPS and antimony trioxide, in a bag for about 2 min. The combination was then extruded, cooled, pelletized, and molded as described in A above, and the IZOD impact strength (ASTM D 256-88) of the molded material was measured.
TABLE 1
______________________________________
Component A (wt %) B (wt %)
______________________________________
HIPS Resin; (Dow 80.5 80.5
Styron .RTM. 492T)
Impact Modifier; 3.0 3.0.sup.a
Sty/But/Sty Block
(Kraton .RTM. D4141 of
Shell Chemical Co.)
Flame Retardant; 12.0 12.0.sup.a
Decabromodiphenylethane
(Ethyl Corp.)
Synergist; Sb.sub.2 O.sub.3
We can supply any quantity and any kind of Antimony products from stock.would you please inform us how many you need and your target price, then we will confirm ASAP. We are sincerely hope to do business with you and establish long term business relationship with your respectable company.
Look forward to hearing from you soon.
Best regards,
Sam Xu
Contact me:
MSN: xubiao_1996@hotmail.com
GMAIL: samjiefu@gmail.com
SKPYE:jiefu1996
Chinese antimony market
...
read more
Subscribe to:
Posts (Atom)