Polycarbonate
Polycarbonate (Polycarbonate)
Abbreviated PC is a colorless, transparent, amorphous thermoplastic material. The name comes from the CO3 group within it.
Chemical properties
Polycarbonate is resistant to acids and oils.
Polycarbonate is not resistant to ultraviolet light or strong bases.
Physical Properties
Polycarbonate colorless and transparent, heat-resistant, impact-resistant, flame-retardant, in the ordinary use of temperature have good mechanical properties. With performance close to polymethyl methacrylate compared to polycarbonate impact resistance, high refractive index, good processing performance, without additives with UL94 V-0 level flame retardant properties. However, polymethyl methacrylate is less expensive than polycarbonate, and can be produced through the method of polymerization of large devices. With the increasing scale of polycarbonate production, the price difference between polycarbonate and polymethylmethacrylate is decreasing.
Polycarbonate has poor abrasion resistance. Some polycarbonate devices used in abrasion-prone applications require special surface treatments.
History
Production and Applications
Polycarbonate is a common material used every day. Due to its colorless transparency and excellent impact resistance, common daily applications include CDs, eye pieces, water bottles, bulletproof glass, goggles, bank bulletproof glass, headlights, etc., animal cages, pet cages, etc.
Production and Applications
Polycarbonate is a common everyday material.
Polycarbonate is also used to make the helmet mask of the moon landing astronauts. Apple's ipod music player and ibook laptop shell also use polycarbonate production.
Environmental impact
Food contact
Because of its clarity and toughness hm producers and buyers of food storage goods prefer polycarbonate fibers. When compared to silica glass, polycarbonate fiber is as lightweight and highly unbreakable. Polycarbonate fibers are mostly used in disposable plastic water bottles and heavy duty plastic water bottles.
Over 100 studies have explored the ecological reactions of bisphenol A leachates in polycarbonate fibers. Howdeshell et al. found that at room temperature an endocrine disruptor, Bisphenol A (C15H16O2) (phenol methane), appears to leach from polycarbonate animal cages into the water and that it may be responsible for the enlargement of the reproductive organs of female rats. The paper published by vom Saal and Hughes in August 2005, analyzing the effects of low doses of bisphenol A leachate, seems to find hints of a relationship between financial support and the conclusions drawn: industry-funded studies appear to tend to find no significant effects; government-funded studies tend to find significant effects.
Susceptibility to chemical interactions with other substances
Sodium oxide and other alkaline detergents should not be used in polycarbonate fibers, otherwise they lead to the release of Bisphenol-A (C15H16O2), a known endocrine disruptor (affecting the reproductive system).
Polycarbonate PC is also one of the materials used in the laptop shell, its raw material is petroleum, processed by the polyester chips factory into a polyester chips granules, and then processed by the plastic factory into a finished product, from a practical point of view, its thermal performance is also better than the ABS plastic, heat dispersion is more evenly distributed, and its biggest drawback is that it is more brittle, a fall on the break.
Status of production
Polycarbonate (PC) as the five engineering plastics in the only transparent products, domestic and international production capacity is growing rapidly, the global production capacity of about 1.85 million tons in 2000, 2.2 million tons in 2001, 2.65 million tons in 2002, 2.75 million tons in 2003, is expected to increase to 2.9 million tons in 2004, and in 2005 to reach 3.25 million tons, an average annual growth rate of about 12% or so.
China's PC production capacity has been small for many years, only three companies to maintain production, production capacity of less than 5,000 tons / a, annual output of about 2,000 tons, with the rapid growth of China's demand for PC, China has set off a PC joint venture to build a device of the boom, Bayer and Shanghai Huayi Chlor-Alkali Chemical Company in the construction of 200,000 tons / a PC device in Shanghai Chemical Industry Park, it is expected that a period of 50,000 tons / a device will be put into operation at the end of 2004, the completion of the second phase of the project in early 2006 to reach 100,000 tons / a, in view of the huge demand for PC market in China, and ultimately will make the PC device to expand to 200,000 tons / a, the device production is mainly optical-grade products for the production of CDs, DVDs optical discs, automotive lighting systems and so on.
Japanese Teijin Chemical is building 50,000 tons / a PC device in Jiaxing, Zhejiang, is expected to go into operation in April 2005, the main raw material bisphenol A by the Japanese Mitsui Chemical supply, chlorine and caustic soda from the local enterprises, carbon monoxide their own production, the product is a general-purpose grade products, mainly for the supply of electrical components, automotive parts production, plans to add a set of 50,000 tons / a production in 2006 At the same time, the company in Shanghai Gaoqiao Trade Free Zone, the sole proprietorship construction of 18,000 tons / a PC, ABS compound device, has been put into production, plans to build in the first half of 2005 to add 20,000 tons / a second production line. Japan's Mitsubishi Gas Chemical Company intends to build 100,000 tons / a PC device in Sichuan, is expected to be put into production in 2007.
In addition, there are a number of domestic enterprises and foreign cooperation or the use of localized technology to build large-scale PC production units, so the next few years, China's PC production will enter a new stage, the domestic production capacity in 2006 will increase to 250,000 tons / a or so, 2010 will reach 500,000 to 600,000 tons / a. For China's PC potential huge market, the famous foreign PC companies not only in China, but also in China. Cooperation in the construction of production units, but also in China, Taiwan, South Korea, Singapore, Thailand and other countries and regions to build a large-scale device, relatively more investment in the device is aimed at China's market. PC production process progress the main development trend is the development of non-photogas synthesis process to replace the main synthesis process interface polymerization of photogas method, GE Plastics and Bayer are to develop their own production of non-photogas production technology and pushed to the industrialization of production, in addition to Asahi / Chimei, Samsung, the main synthesis process interface polymerization of photogas, and to the industrialization of production. In addition, Asahi / Chimei, Mitsubishi Chemical / Mitsubishi Gas, Teijin, LG Chemical Company have developed non-photogas process technology, are building or planning to build non-photogas PC plant, non-photogas route will become the main production route of the future PC.
Market Analysis
Since the late 1990s, China's PC demand from the original textile industry with the sand pipe to electronic / electrical, optical discs, construction, the automotive industry and other fields, the demand has increased dramatically. 1999 domestic consumption of about 140,000 tons, while the consumption in 2003 increased to reach 380,000 tons, with an average annual growth rate of about 28%, much higher than the average growth rate of the national economy and the rest of the growth rate of the national economy, the average growth rate of the national economy, the average growth rate of the national economy, the average growth rate of the national economy. The average annual growth rate is about 28%, which is much higher than the average growth rate of the national economy and the growth rate of other general engineering plastics. As the domestic production is very small, China's use of PC is mainly imported from abroad. 1999-2003 China's net imports of PC were 138,000 tons, 235,000 tons, 212,000 tons, 342,000 tons, 381,000 tons, and has not yet included a considerable number of smuggled in the PC, but also did not take into account the import of finished products and trimmings, so the actual domestic imports and consumption data than the above Customs statistics are much higher than the domestic and foreign PC industry agreed that China's market potential is huge and relatively stable.
1999-2003 China's rapid growth in the PC market is mainly electrical and electronic products, hollow sunshine board, CD and DVD discs and non-disposable drinking water barrels and food containers demand driven, at present, China's PC consumption structure is roughly as follows: electrical and electronic and computer accessories accounted for about 42%; hollow sunshine board accounted for about 26.3%; CD and DVD discs accounted for about 13.1%; drinking water barrels and food containers accounted for about 10.5%; composite materials and automotive industry and other fields accounted for about 9.1%. In the next few years, China's original major consumer areas will continue to maintain the momentum of high growth, computers and household appliances continue to grow, the field of the future average annual growth rate of about 10% -12% of the PC; railroads, highways, airports and urban construction, the demand for hollow sunshine board is still strong, and in recent years, the domestic Yangtze River and the Pearl River Delta area of the use of PC processing and production of sheet metal enterprises economic efficiency than many of the Polymer resin production enterprises is much better, it is expected that the future demand for hollow sunshine board PC average annual growth rate of 12-15% or so; at present, China has become the world's second largest consumer of CD-ROMs, previously all relied on imports of CD-ROM PC production, with Bayer Shanghai CD-ROM grade PC put into operation in the next few years, CD-ROM PC demand will remain more than 20% high growth; experts predict that the fastest-growing areas of domestic demand for PC will be in the areas of railways, highways, airports and urban construction. The fastest-growing area of demand will be the PC as a substrate **** mixed gold composite materials, of which the automotive industry will be the main driving force. It is expected that in the next few years the average annual growth rate of China's PC demand will remain between 15% -20%, in 2006, the domestic market demand for PC will reach 550,000 -650,000 tons / a. Domestic production capacity is still unable to meet the needs of the domestic market, will be imported from the neighboring countries of Japan, South Korea, Thailand, etc. a large number of products to supply the domestic market.
PC / ABS alloy new varieties are mainly used in the automotive industry application progress
At present, the global PC application has been to the high-functionality, specialization direction, in view of China's PC production capacity and market demand have shown a rapid development of the situation, in particular, the construction of a number of sets of domestic scale device, coupled with the rapid development of the automotive industry pulling the next few years in China's PC industry into a new stage of development, of which the most critical is the development of the PC industry. In the next few years, China's PC industry will enter a new stage of development, of which the most critical is to accelerate the application of PC research.
First of all, domestic manufacturers should take full advantage of the increase in domestic production capacity and experience accumulated in the plastic modification and plastic alloys, to accelerate the development of PC alloys and other composite materials, production and application, the most important of which are:
PC/ABS alloys, PC and ABS **** mixture can be integrated PC and ABS's excellent performance, on the one hand, it can improve ABS's Heat resistance, impact resistance and tensile strength, on the other hand, can reduce the cost of PC and melt viscosity, improve processing performance, reduce the product internal stress and impact strength of the product thickness sensitivity. Currently PC / ABS alloy development is rapid, the global production of about 850,000 tons / a or so, China's demand for about 200,000 tons / a or so. The world's major companies have developed and launched new varieties of PC / ABS alloys, such as flame retardant, glass fiber reinforced, plating, UV resistance and other varieties, mainly used in the automotive industry, computers, photocopiers and electrical and electronic components. The main domestic research and production companies are Shanghai Jieshijie company, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Lanzhou University and other units.
PC / PBT (polybutylene terephthalate) alloy, PBT and PC **** mixed alloy materials can improve the PC mobility, improved processing performance and chemical resistance. Japanese researchers with PC and PBT in the presence of ester-exchange catalysts, the production of PC / PBT **** blend, good overall performance, but also has good transparency; with PC refractive index of glass fibers similar to PC / PBT, not only the system's overall performance is excellent, but also has a very good transparency, can be done in lieu of glass materials. At present, foreign PC / PBT alloy products are mainly used for automobile bumpers, packaging film materials, automobile base and seat. Domestic research has just begun.
In addition PC / PS (polystyrene) alloy, PC / PET (polyethylene terephthalate) alloy, liquid crystal polyester modified PC, PET / PCL (from ethylene glycol, low molecular weight polyethylene lactone and terephthalic acid **** polymerization into a multiblock **** polyester) and PC **** mixing modified poly (1,4-cyclohexanedicarboxylic acid - 1,4-cyclohexane-dimethanol) The poly(1,4-cyclohexanedicarboxylic acid-1,4-cyclohexanedimethanol) ester-modified PC deserves attention and research development.
Secondly, we should follow the international development trend, coupled with the PC alloy material research continues to progress, PC applications continue to expand, to accelerate the expansion of the field of PC consumption.
Wide-wave transmissive optical instruments,
PC sheet is particularly suitable for the production of eyeglass lenses, the introduction of silicon-oxygen groups in the PC molecular chain, you can improve its hardness and resistance to abrasion.PC as a high refractive index plastic, used to make high-temperature resistant optical fiber core material, if the C-H chain in the PC molecular chain for the replacement of the C-F chain, it can be a reduction of the absorption of visible light, and can Effectively reduce the signal loss on the way of transmission. In addition PC good light transmission, in transparent window materials, high-rise building curtain walls, airports and stadiums transparent building materials such as the application is very common and has the potential to focus on improving the surface hardness and antistatic properties in the future. pc sheet impact resistance. Thinness of eyeglass lenses: Ordinary resin is very thick, glass is thicker, medium-folding resin is thinner, PC and high-folding resin is thinner, and high-folding glass is the thinnest.
Flame retardant environmentally friendly communication appliances, the future should focus on the development of flame retardant PC used in the field of communication appliances, so non-polluting flame retardant PC materials have become the focus of the development of bromine flame retardant due to the toxicity of the reduction in the use of halogen-free environmentally friendly phosphorus flame retardant will significantly reduce the PC's heat distortion temperature and impact strength, and therefore the more appropriate is the silicone system of flame retardants. In addition, with the lightweight miniaturization of communication appliances on the PC material to put forward higher requirements, the current PC / ABS alloy is particularly suitable for use in communication appliances and aerospace industry.
Surface metallization of automotive parts, PC surface metallization has a good metallic luster and high strength, widely used in a variety of automotive parts, but the plating process will reduce its impact toughness, so the use of elastomers and PC **** mixing modification, containing elastomers dispersed to the cracking stress, although plating will not reduce its impact toughness, so plating level PC resin Therefore, plating grade PC resin is very promising. In addition, the surface metallization of the PC can also be used as a shielding material for electromagnetic waves, used in computers.
Low residual harmful food containers, industrial synthetic PC is bisphenol A type, due to the synthesis of trace unreacted monomer bisphenol A residue in the resin, as drinking water barrels and food containers, easy to be dissolved so as to affect the health of the people, and therefore the development of sanitary PC resin, used as a drinking water barrels and other food containers and the production and use of water barrels and other food containers. Food packaging materials and containers PC in the domestic application prospects are very favorable.
Anti-cracking and embrittlement of medical devices, PC has many excellent properties, has been applied to medical devices, due to its poor chemical resistance, in the presence of chemicals prone to internal stress cracking, such as PC in the artificial dialyzer, artificial lungs, and other medical devices to solve the problem of high temperature disinfection leads to cracks in the aging phenomenon, if we overcome these shortcomings, the application of PC in the medical equipment can be rapidly expanded.
Packaging for food and beverage products.
Food packaging materials and containers PC in the domestic application of good prospects