阅读说明：本技术 一种液体硅橡胶及其制备方法 (Liquid silicone rubber and preparation method thereof ) 是由 李书兵 陈泽雨 孙刚 李岩松 于 2019-10-22 设计创作，主要内容包括：本发明提供了一种液体硅橡胶及其制备方法,按重量份计由以下原料组分混合制成：α,ω-二乙烯基聚甲基三氟丙基硅氧烷100份,甲基苯基含氢硅油1-5份,侧链乙烯基共聚甲基乙烯基三氟丙基硅氧烷5-20份,气相二氧化硅20-40份,加工助剂1-2份,催化剂0.5-1份,抑制剂0.01-0.1份。相比于常规加成型液体硅橡胶,通过引入含氟基团,赋予本发明液体硅橡胶具备良好的耐油性、耐腐蚀性和耐低温性能；通过引入苯基,赋予本发明液体硅橡胶良好的高低温、阻尼、耐辐射性能、生理惰性、电学性能和光学性能；乙烯基聚甲基三氟丙基硅氧烷与甲基苯基含氢硅油在铂金催化剂的作用下,通过硅氢加成反应交联固化,形成具备复合性能的材料,使得本发明液体硅橡胶具备更宽的应用领域。(The invention provides liquid silicone rubber and a preparation method thereof, wherein the liquid silicone rubber is prepared by mixing α, 100 parts of omega-divinyl polymethyl trifluoropropyl siloxane, 1-5 parts of methylphenyl hydrogen-containing silicone oil, 5-20 parts of side-chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane, 20-40 parts of fumed silica, 1-2 parts of processing aid, 0.5-1 part of catalyst and 0.01-0.1 part of inhibitor.)

1. The liquid silicone rubber is characterized by comprising the following raw materials, by weight, α, 100 parts of omega-divinyl polymethyl trifluoropropyl siloxane, 1-5 parts of methylphenyl hydrogen-containing silicone oil, 5-20 parts of side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane, 20-40 parts of fumed silica, 1-2 parts of a processing aid, 0.5-1 part of a catalyst and 0.01-0.1 part of an inhibitor.

2. A liquid silicone rubber according to claim 1, wherein the α, ω -divinylpolymethyltrifluoropropylsiloxane has a viscosity of 2000mpa.s to 20000 mpa.s.

3. A liquid silicone rubber according to claim 1, wherein α, the omega-divinylpolymethyltrifluoropropylsiloxane has a fluorine content of 10% to 100%.

4. A liquid silicone rubber as claimed in claim 1, wherein: the viscosity of the methyl phenyl hydrogen-containing silicone oil is 20-500 mPa.s.

5. A liquid silicone rubber as claimed in claim 1, wherein: the viscosity of the side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane is 1000-10000 mPa.s; the specific surface area of the fumed silica is 200-400m²/g。

6. A liquid silicone rubber as claimed in claim 1, wherein: the molar ratio of the vinyl content to the silicon-hydrogen bond content in the system is 1: 1.1-1.5.

7. A liquid silicone rubber as claimed in claim 1, wherein: the processing aid is hexamethyldisilazane.

8. A liquid silicone rubber and a method of producing the same as claimed in claim 1, wherein: the catalyst is one or the combination of chloroplatinic acid-isopropanol complex and chloroplatinic acid-divinyl tetramethyl disiloxane complex, and the platinum content is 2000-5000 ppm.

9. A liquid silicone rubber as claimed in claim 1, wherein: the inhibitor is acetylene alcohol or propiolic alcohol.

10. A method of preparing a liquid silicone rubber as claimed in any one of claims 1 to 9, comprising the steps of:

(1) preparing base glue, namely adding α, omega-divinyl polymethyl trifluoropropyl siloxane, fumed silica and a processing aid into a kneader for mixing, mixing for 1-2h at the temperature of 10-60 ℃, heating to 100 ℃ and 150 ℃ for mixing for 2-3h, heating to 150 ℃ and 180 ℃, mixing for 1-2h under the vacuum degree of-0.1 to-0.05 MPa, adding side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane for diluting, and cooling to obtain the base glue;

(2) preparation of component A: adding the base rubber and the catalyst into the kneading and uniformly mixing;

(3) preparation of component B: adding the base rubber, the methyl phenyl hydrogen-containing silicone oil and the inhibitor into kneading and uniformly mixing;

(4) the components A, B are mixed according to the mass ratio of 1:1, and the liquid silicone rubber is prepared after vacuum defoaming.

Technical Field

The invention relates to the field of silicone rubber, in particular to liquid silicone rubber and a preparation method thereof.

Background

In recent years, new energy automobiles are explosively increased, silicon rubber is mainly applied to special parts such as sealing, shock absorption, rubber tubes, filling, encapsulating and coating in automobiles, and with the development of the automobile industry towards the direction of light weight, greening, intellectualization and sharing, the application of silicon rubber in automobiles is further increased, and particularly, the increase of liquid silicon rubber is most obvious. However, the conventional liquid silicone rubber has the problems of poor oil resistance and solvent resistance, difficult meeting of light transmission performance and the like.

The fluorine-containing material has many excellent service performances such as chemical corrosion resistance, high and low temperature resistance, aging resistance, low friction, insulation and the like, is widely applied to advanced scientific and technical fields such as aerospace, rockets, missiles, atomic energy, aviation and the like, and aspects such as military industry, chemical industry, machinery, electronic and electrical products, textile, transportation, construction, medical sanitation, living appliances and the like, and plays an extremely important role.

F atoms in trifluoropropyl have a larger electron-withdrawing effect, and the bond length of the C-F bond is shorter, so that a better shielding effect on the C-C bond can be formed, the oil resistance and the solvent resistance of the rubber are greatly improved, the rubber has the performance of resisting media such as aviation fuel, hydraulic oil, petroleum series, chemical reagents and the like at high temperature, and is an elastomer with good non-polar medium resistance at the temperature of-68-232 ℃, the liquid fluorosilicone rubber is mainly applied to automobile manufacturing and aviation industry, the application of the existing liquid fluorosilicone rubber is further expanded to the aspects of consumer goods and medical health care, but the conventional liquid fluorosilicone rubber has low transparency and is difficult to use in the field with high light transmission requirements. The phenyl is introduced into the silicon rubber, so that the silicon rubber has good high and low temperature, damping, radiation resistance, physiological inertia, electrical property and high refractive index.

According to the invention, the fluorine-containing siloxane and the phenyl-containing siloxane are subjected to hydrosilylation reaction for crosslinking and curing to prepare the organic silicon rubber material which can resist oil, high and low temperature and has high refractive index.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides liquid silicone rubber and a preparation method thereof, wherein α, omega-divinyl polymethyl trifluoropropyl siloxane and methyl phenyl hydrogen-containing silicone oil are used as base materials, fumed silica, a processing aid and a coupling agent are added, and the silicone rubber material which can resist oil, high and low temperature and has high refractive index is prepared by crosslinking and curing under the action of a platinum catalyst.

In order to achieve the purpose, the invention adopts the following technical scheme:

α, 100 parts of omega-divinyl polymethyl trifluoropropyl siloxane, 1-5 parts of methylphenyl hydrogen silicone oil, 5-20 parts of side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane, 20-40 parts of fumed silica, 1-2 parts of processing aid, 0.5-1 part of catalyst and 0.01-0.1 part of inhibitor.

α, the viscosity of the omega-divinyl polymethyl trifluoropropyl siloxane is 2000 mPa.s-20000 mPa.s, and the fluorine content is 10% -100%;

the viscosity of the methyl phenyl hydrogen-containing silicone oil is 20-500 mPa.s;

the viscosity of the side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane is 1000-10000 mPa.s;

the molar ratio of the vinyl content to the silicon-hydrogen bond content in the system is 1: 1.1-1.5;

the specific surface area of the fumed silica is 200-400m²/g；

The processing aid is hexamethyldisilazane;

the catalyst is any one or the combination of a platinum catalyst, a chloroplatinic acid-isopropanol complex and a chloroplatinic acid-divinyl tetramethyl disiloxane complex, and the platinum content is 2000-5000 ppm.

The inhibitor is acetylene alcohol or propiolic alcohol.

A preparation method of liquid silicone rubber comprises the following steps:

(1) preparing base glue, namely adding α, omega-divinyl polymethyl trifluoropropyl siloxane, fumed silica and a processing aid into a kneader for mixing, mixing for 1-2h at the temperature of 10-60 ℃, heating to 100 ℃ and 150 ℃ for mixing for 2-3h, heating to 150 ℃ and 180 ℃, mixing for 1-2h under the vacuum degree of-0.1-0.05 MPa, adding side chain vinyl copolymerized methyl vinyl trifluoropropyl siloxane for dilution, and cooling to obtain the base glue;

(2) preparation of component A: adding the base rubber and the catalyst into the kneading and uniformly mixing;

(3) preparation of component B: adding the base rubber, the methyl phenyl hydrogen-containing silicone oil and the inhibitor into kneading and uniformly mixing;

(4) the components A, B are mixed according to the mass ratio of 1:1, and the liquid silicone rubber is prepared after vacuum defoaming.

Compared with the prior art, the invention has the following beneficial effects:

①, compared with common fluorine-free liquid silicone rubber, the liquid silicone rubber has good oil resistance, corrosion resistance and high temperature resistance by introducing fluorine-containing groups;

② the liquid silicone rubber of the invention has good high and low temperature, damping, radiation resistance, physiological inertia, electrical property and optical property by introducing phenyl;

③ the vinyl polymethyl trifluoro propyl siloxane and methyl phenyl hydrogen silicone oil are cross-linked and solidified through hydrosilylation reaction under the action of platinum catalyst to form the material with composite performance, so that the liquid silicone rubber has wider application field.

Detailed Description

The technical solution of the present invention is further illustrated by the following examples.