Low-hardness high-tear-resistance self-lubricating addition type liquid silicone rubber, preparation method and application thereof

A technology of silicone rubber and silicone rubber composition, applied in the field of silicone rubber, can solve the problems of high hardness, inability to meet the requirements of cyclic plugging and use of automobile plug-in parts, damage and the like

Active Publication Date: 2020-06-19

JIANGXI BLUESTAR XINGHUO SILICONE CO LTD

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AI-Extracted Technical Summary

Problems solved by technology

[0005] Patents CN100549098C and CN104479365B both disclose a self-lubricating silicone rubber. The composition has good surface lubricity, but the hardness is high, and it is easy to cause damage when the rigid metal head passes through, and the ability to resist damage is poor

[0006] Patent CN10266729B discloses a vulcan...

Abstract

The invention discloses low-hardness high-tear-resistance self-lubricating addition type liquid silicone rubber, a preparation method and application thereof. The silicone rubber composition comprisesa component A and a component B, wherein the component A is prepared from the following raw materials in parts by weight: 70 to 100 parts of a base rubber, 0.004 to 0.4 part of a Si-H addition catalyst and 2 to 22 parts of alkenyl-containing polysiloxane, the component B is prepared from the following raw materials in parts by weight: 70 to 100 parts of a base rubber, 2 to 10 parts of alkenyl-containing polysiloxane, 1 to 6 parts of hydrogen-containing silicone oil and 0.4 to 4 parts of a hydrogen-containing silicone resin, and the silicone rubber obtained after vulcanization molding has thehardness of 17-22 Sh.A, the tearing strength of larger than 35 KN.m<-1> and the tensile strength of larger than 8 Mpa. According to the high-tear-resistance self-lubricating liquid silicone rubber provided by the invention, the tear resistance of the liquid silicone rubber within the hardness range of 17-21 Sh.A is improved to 35 KN.m<-1>, and the high-tear-resistance self-lubricating liquid silicone rubber can be applied to the field of high-end automobile plug pieces.

Technology Topic

Silicone resinPolymer chemistry +8

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Examples

Experimental program(4)
Comparison scheme(5)
Effect test(2)

Example Embodiment

[0077] Preparation Example 1

[0078] In a kneader or a planetary mixer, 37 parts by weight of vinyl-terminated polysiloxane with a viscosity of 100,000 mPa·s and an alkenyl content of 0.026 mmol/g, and 7.8 parts of vinyl polysiloxane with a viscosity of 60,000 mPa·s and an alkenyl content of 0.030 The vinyl-terminated polysiloxane of mmol/g, the specific surface area of 25 parts BET is 300m 2 /g of fumed silica and 7.05 parts of hexamethyldisilazane, 0.15 parts of tetramethyldivinylsilazane and 6.5 parts of deionized water were fully mixed under the protection of an inert atmosphere at 80°C for 1 ~ 2 hours, then heat up to 130 ~ 150 ° C and start vacuuming for 2 ~ 4 hours, keep the temperature at 150 ~ 170 ° C during vacuuming, then cool down to 110 ~ 140 ° C, add 16.5 parts of viscosity 20000mPa·s alkenyl content is 0.035mmol/g vinyl-terminated polysiloxane, and stir evenly to obtain liquid silicone rubber base rubber 1.

Example Embodiment

[0079] Preparation example 2

[0080] In a kneader or a planetary mixer, 40 parts by weight of vinyl-terminated polysiloxane with a viscosity of 60,000mPa·s and an alkenyl content of 0.030mmol/g, and 2.5 parts of vinyl polysiloxane with a viscosity of 200,000mPa·s and an alkenyl content of 0.035 The specific surface area of mmol/g of vinyl-terminated polysiloxane and 27.5 parts of BET is 400m 2 /g of fumed silica and 8 parts of hexamethyldisilazane, 0.5 parts of tetramethyldivinylsilazane and 4.5 parts of deionized water were fully mixed under the protection of an inert atmosphere at 80°C for 1 ~ 2 hours, then heat up to 130 ~ 150 ° C and start vacuuming for 2 ~ 4 hours, keep the temperature at 150 ~ 170 ° C during vacuuming, then cool down to 110 ~ 140 ° C, add 17 parts of viscosity 60000mPa·s alkenyl content is 0.030mmol/g vinyl-terminated polysiloxane, stirred evenly to obtain liquid silicone rubber base rubber 2.

[0081] Example Preparation of liquid silicone rubber

Example Embodiment

[0082] Example 1

[0083] Preparation and vulcanization of component AB: 85 parts of the above base rubber 1, 4.5 parts of vinyl-terminated polysiloxane with a viscosity of 3500mPa·s and an alkenyl content of 0.08mmol/g, 4 parts of a vinyl-terminated polysiloxane with a viscosity of 1000mPa·s, Side chain vinyl polysiloxane with a group content of 0.12mmol/g, 0.5 parts of vinyl polysiloxane with a viscosity of 400mPa·s and an alkenyl content of 0.9mmol/g in both terminal and side chains, 0.012 parts of cal Stir-type platinum catalyst, 6 parts of methylphenylpolysiloxane with a viscosity of 120mPa s and a refractive index of 1.49, stirred and dispersed in a planetary mixer for 30-40min, mixed evenly and then vacuumed and defoamed to obtain a self-lubricating low-pressure variable liquid Silicone rubber component A.

[0084] 85 parts of the above-mentioned gum base 1, 1.5 parts of vinyl-terminated polysiloxane with a viscosity of 3500 mPa·s and an alkenyl content of 0.08 mmol/g, and 4 parts of a viscosity of 1000 mPa·s and an alkenyl content of 0.12 mmol/g 6 parts of methylphenyl polysiloxane with a viscosity of 120mPa·s and a refractive index of 1.49, 0.5 parts of both ends and side chains with a hydrogen content of 7mmol/g and a viscosity of 20mPa·s Both contain SiH hydrogen-containing silicone oil, 2 parts of hydrogen-containing silicone oil with a hydrogen content of 2 mmol/g and a viscosity of 10 mPa·s containing SiH at both ends, and 1 part of a hydrogen-containing silicone resin with a hydrogen content of 8 mmol/g and a viscosity of 30 mPa·s. 0.16 parts of 3-methyl-1-dodeyn-3-ol, stirred and dispersed in a planetary mixer for 30-40 minutes, mixed evenly, and then vacuumed and defoamed to obtain self-lubricating low-pressure variable liquid silicone rubber B component.

[0085] Mix components A and B in equal mass proportions evenly, then vulcanize at 170°C for 5 minutes to make a 2mm test piece, and vulcanize at 170°C for 10 minutes to get a sample block for pressure deformation test.

PUM

Property	Measurement	Unit
Viscosity	30.0	mPa·s
Tear strength	>= 35.0	kN/m

Description & Claims & Application Information

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