Silicone material

Organic enjoy " industrial monosodium glutamate"," science and technology development catalyst " and reputation of the silicone is a synthetic,  structure on silicon atoms and oxygen atoms as main chain polymer. Since the chain Si-O bond has high bond energy, so the organosilicon polymers on  heat, oxygen stability than general organic polymer is much higher. Although silicon at room temperature on the mechanical properties and other material  difference is not big, but in the high and low temperature showed excellent physical, mechanical properties, in60~ 250 degrees between the multiple  alternating, its performance is not affected, and some can even at - 100 degrees C under normal use; with high and low temperature resistance,  electrical insulation, ozone resistance, radiation resistance, flame resistance, water repellency, corrosion-resistant, non-toxic and  tasteless and biologically inert. Nowadays, the silicone has been widely used in electronic and electrical, construction, textile,  light industry, medical and other industries, and in the automotive industry have a wide range of applications. 1silicone market  situation at present, the global silicone has more than 10000 kinds of varieties. In 2004 the world's total market size of about  US $9000000000. Grouped by industry, silicone rubber, resin consumption form, coatings, fibers, paper, cosmetics and other  chemical related industry 40%, electric20%, building20%, the other 20%.         At present, all kinds of silicone products total consumption accounts for the total output of world synthetic resin  (100000000 T ) of O.65%, developed countries regard the silicone materials as2l century new materials of the key to the development.         According to the SRI report,2003, the United States market for silicone products demand continuing to 4% ~ 6% rate.  Silicone industry to the local gross national product ( GDP )2 ~3 times the rate of growth, especially in the automotive  and construction market. The next few years, the Latin American and Middle Eastern silicone material corresponding to the  product market will be higher than the global average rate of growth; the United States of America and Western Europe is  the global silicone most mature market, will continue to higher than the GDP growth rate; in Asia, silicone materials rapid  consumption growth, mainly concentrated in the except Japan other Asian regions and countries, can be expected, the Asian  region silicone business growth in the world will remain the most powerful.   In 2004 China silicone market continued to maintain a rapid growth trend. In 2004, the primary shape polysiloxane import  volume is 143762 T, compared with 101710 in 200341% t growth: export volume is 20838 T, than going up year of  growth94%10737 T; the net import volume is122924 T, than going up year of growth 35%90973t. China s eight methyl  four ring siloxane ( Dd ), two methyl cyclosiloxane mixture ( DMC ) presents the state that demand exceeds supply.        Domestic organosilicon methyl monomer consumption in recent years to more than 20% of the annual rate of increase,  growth rate is quite rapid. If the import organosilicon methyl monomer and products is also included, its consumption is larger.   2.silicone materials development   The 2.1 silicon rubber   2.1.1heat-resistant silicone rubber silicone rubber has good heat resistance, at - 80to 250 DEG C in a wide range of  maintaining good flexibility, so it is widely used in high temperature applications. With the development of science  and technology especially the defense and the development of the sophisticated technology of its heat resistance, raised  taller requirement. In recent years, people on the heat resistance of silicone rubber were studied extensively. Wei Borong  and others, in the silicone rubber was added in the 5~10silicone resin can improve the silicone rubber heat resistance and  comprehensive performance.         Zheng Junping et al that, iron tin composite oxide having multiple antioxidant mechanism, so as to play a synergistic  effect, can improve the heat resistance of silicone rubber.   Huang Feng and the others find, iron oxide copper complexes in a certain temperature range can inhibit the growth of silicon  rubber thermal oxidative degradation, improve silicone rubber heat aging resistance, and better performance than ferric oxide.   Wu Weili uses 4~5DCP as curing agent,2 copies of DBPMH as curing agent,40 copies of precipitated silica as reinforcing agent,11  to 15 portions of ferric hydroxide as heat-resistant additives, successfully developed a high temperature of 300DEG C of the silicone  rubber.   2.1.2liquid silicone rubber   Liquid silicone rubber injection molding technology studies began in the nineteen seventies, originally designed for the  preparation of shape complex products, such as aviation big sealing fittings. Arrived 80 time, liquid silicone rubber  begins to get the attention of various countries, demand is increasing rapidly. Because the liquid silicone rubber injection  forming not only has the advantages of low cost, low energy consumption, high production efficiency, can carry out the  advantages of automated production, and adaptability to temperature is very good also, in a wide range of temperature can  keep the good elasticity, so its increasingly wide range of applications. According to SRI research report1998, liquid  silicone rubber sales of only 90KT, thereafter to more than 10% of the average annual growth rate. Raw material prices  than ordinary silicon rubber was slightly higher, but the total cost was lower than ordinary silicon rubber, especially  manufacturing products and more demonstrated its superiority in this aspect.   Laur silicone rubber company a new generation of liquid silicone rubber applied advanced and stable vulcanization technology,  solves the two-component liquid silicon rubber and some existing problems. This material is a single component, to cooperate  fully with the can be used after the. Although the material is still in the early commercialization, but because has the following  advantages, application prospect is very broad: to cooperate fully with the -- without mixing operation; no ratio improper  material; no need for cleaning the mixing device; the cleaning process without material loss; excellent physical  properties ( tensile strength, elongation, tear strength, thermal aging performance, compression permanent deformation );  and long storage life; curing cycle is short; in line with the United States Food and drug administration, standard; tunable;  different hardness of rubber mix.   Shincor Silicones company developed new grade liquid silicone rubber KEG2000 series has excellent physical properties and  processing properties. The KEG 2000series of liquid silicone rubber with the current without glue edge, automatic pressing  needs, at low shear stress ( pump and flow ) of high viscosity, high shear stress ( injection ) lower viscosity at.  Allegedly, the KEG 2000 series also has excellent gate balance, wide processing range and prominent release properties,  high transparency, Shao Er A hardness of 20 ~75 degrees.   Wacker company developed white viscous liquid silicone rubber Elastosil LR 3070 series products. The series of liquid  silicone rubber as a gel, easy coloring two-component mixture, in a short period of time can fast curing; even without  a primer, but also on various materials ( from a thermoplastic, thermoset resin to metal or glass) has an excellent  adhesion properties, which makes it a very with insert products ideal material. Type liquid silicon rubber also has  excellent mechanical and electrical properties; therefore, the injection molding or processed at high temperature.  With insert products ( such as shower nozzle, steering wheel, buttons ) can once shaping. It can not only reduce  the unit cost, but also can reduce energy consumption. Elastosil LR 3070series of products in the medical, electrical  and electronic equipment in the field of use is very extensive.   NuSil Technology launched the self-lubricating type liquid silicon rubber after molding, can be treated elastomer  surface covered with a layer of silicone liquid, thereby avoiding the silicone layer are bonded to each other or  obstruction. The self-lubricating type liquid silicon rubber more varieties, the Shao Er A hardness of from 15to 60  degrees. Potential applications including medical diaphragm, brake,0 type ring gasket, valve, etc..   Japan's Asahi rubber company and its subsidiary company Fine Rubber Research Institute jointly developed silicone  rubber Ninax is resistant to high temperature of 300 DEG C. The adhesive has the following characteristics : at 300  degrees C can be used for a long time, and can keep good strength and softness; in the heating and compression  condition does not harden, particularly applicable to the production of O ring, gasket; processing performance with  ordinary silicon rubber, and price than the best heat resistance of fluoro rubber cheap some parties, and can replace  the fluorine rubber is used; the use of safety, the human body and the environment without adverse effects.   Wang Baiya and others developed the GT - I thermal coating with phenyl silicone rubber as substrate, joining Si02filler,  its density is 1.2 g / cm3, specific heat capacity is 1.256 J / ( g K ), thermal conductivity is 0.31 W / ( m K ), has  been successfully used for the heat warhead bottom.