KR20030039119A - Silicone rubber composition for high voltage insulator - Google Patents

Abstract

PURPOSE: A silicone rubber composition for an insulator is provided, to improve mechanical strength, heat resistance, flame retardancy and workability. CONSTITUTION: The silicone rubber composition comprises 100 phr of a VMQ-type polyorganosiloxane containing at least two vinyl groups in a molecule; 1-20 phr of polyorganosiloxane which has at least one hydroxy group combined with a silicon atom and whose viscosity is 50-200 cp at a temperature of 25 deg.C; 5-100 phr of a reinforcing silica; 0.1-10 phr of polyorganosiloxane having a Si-H group; and 0.001-0.1 phr of a platinum catalyst. Preferably the polyorganosiloxane containing at least two vinyl groups in a molecule has a molecular weight of 100,000-700,000 and has an average degree of polymerization of 2,000-10,000; and the polyorganosiloxane having a Si-H group contains at least two hydrogen atoms bonded directly to the silicon atom, and is represented by the formula 1, wherein R2 is a methyl group, an ethyl group, a propyl group, a phenyl group or a fluoro group; and m and n are an integer and 1<m+n<500.

Description

Silicone rubber composition for high voltage insulator

The present invention relates to a silicone rubber composition for insulation insulator, and to a silicone rubber composition for insulation insulator which can improve the strength and reduce the weight of the high pressure insulated millable silicone rubber used to support electric wires in electric work, etc will be.

In general, insulators are insulators or insulators that do not conduct electricity or heat, and a plurality of corrugations are formed on the surface to have sufficient electrical insulation strength. ), Long-term insulators, home insulators (used to withstand fouling during typhoons), distribution lines: pin insulators, indoor wiring lines: knob insulators, love insulators, cleat insulators, circuit breakers, lightning arresters Dragon: There are supporters

In the case of a conventional high pressure insulator millable silicone rubber, 50 to 150 phr of ATH (aluminum tri hydroxide) was added to prepare a silicone rubber compound having excellent tracking resistance.

However, the conventional high pressure insulated millable silicone rubber has a weak physical and mechanical strength, inferior workability by the crystallized water of ATH, and the specific gravity increases by the ATH to increase the weight of the insulator. In addition, the decomposition temperature of the ATH is 250 ℃ ~ 300 ℃ low heat resistance has a variety of problems, such as poor point.

The present invention has been made in consideration of the above problems, and an object thereof is to provide a silicone rubber composition for insulation insulator having high strength properties, excellent heat resistance and flame retardancy, and improved workability.

The present invention in the silicone rubber composition for insulators; The silicone rubber composition is 100 phr of polymethyl organosiloxane of the MBM type containing at least two vinyl groups in the molecule; Reinforcing silica 5-100 phr; Polyorganosiloxane containing at least one hydroxyl (OH) bonded to a silicon atom and having a viscosity of 50 to 200 cp (centi poise) at 25 ° C., 1 to 20 phr; 0.1-10 phr of polyorganosiloxane with Si-H groups; It is to provide a silicone rubber composition for insulators consisting of 0.001 ~ 0.1 phr platinum catalyst.

The present invention is a polyorganosiloxane, which is a silicone type silicone polymer having a methylmethyl siloxane in a chain or a dimethyl vinyl siloxane at its end, as a first component, and a polyorganosiloxane having an OH group at its terminal as a second component. , A polyorganosiloxane having a Si-H group as a third component, a silicone rubber was prepared by adding reinforcing silica to the first, second, and third components, and then a platinum catalyst was added to the high strength tracking resistance silicone rubber. To form.

The polyorganosiloxane, which is the first component, is 100 Mm of a silicone polymer of YMV type, has 0.01 to 10 mol% of vinyl groups in the entire organic group, and contains at least two or more vinyl groups in the molecule and has a molecular weight of 10 It is 700,000 in a bay and the average degree of polymerization is in the range of 2000-10,000.

The second component polyorganosiloxane is added 1 ~ 20 phr, containing at least one hydroxyl (OH) bonded to the silicon atom, the viscosity is 50 ~ 200 cp (centi poise) at 25 ℃ Equipped.

The polyorganosiloxane of the third component is added 0.1 ~ 10 phr, it is represented by the formula (1).

Formula 1

The organo-halogen polysiloxane is a polyorganosiloxane containing at least two or more hydrogen atoms directly bonded to silicon atoms in one molecule, and preferably has a structure such as Formula (1). The amount of use is suitably 0.1-10 phr with respect to the said 1st component. That is, based on 100 phr of the first component polyorganosiloxane, 0.1 to 10 phr of the third component polyorganosiloxane is used. (The phr means an addition amount to the resin (polymer) 100. The present invention is based on the first component "polyorganosiloxane"

In this case, the substituent R ₂ may be a methyl group, an ethyl group, a propyl group, a phenyl group, a flor group, and the like, of which a methyl group, an ethyl group, and a propyl group are most suitable.

Moreover, m and n are 0 or a positive integer, 1 <m + n <500 is preferable, m is 5 to 30, and n is more preferably 10 to 200.

The reinforcing silica is added to impart strength to the polymer, and both dry silica and wet silica having a surface area of 100 m 2 / g or more are possible, and preferably dry silica is used.

The platinum catalyst uses a single platinum or platinum compound, and is a catalyst for carrying out the addition reaction of silicon-bonded hydrogen atoms in the first component and the third component. Specific examples thereof include a single platinum, H ₂ PtCl ₆ nH ₂ O, NaHPtCl ₆ nH ₂ O, PtCl ₄ , PtCl ₄ nH ₂ O, PtCl ₂ are used which are dissolved in siloxane and alcohol.

In addition, the addition amount of the said platinum or platinum compound is a catalytic amount, and 0.001-0.1 phr is added as platinum with respect to the vinyl group containing polyorganosiloxane of a 1st component.

Hereinafter, the manufacturing method of the present invention will be described based on Examples.

Example 1

30-50 kg of dry silica in 100 kg of the high-viscosity silicone polymer of the first type of MBM, and 3-5 kg of polyorganosilixane in which the OH group, which is the second component, is present at the end, and Si-H, which is the third component 1.0 kg of a siloxane having a group is produced using two rolls or a kneading machine to produce silicone rubber. It is added to the platinum compound 0.01 ~ 0.03 kg in a roll cooled to 25 ℃ or less to prepare a high-strength tracking resistance silicone rubber. The molding method can be used for about 10 minutes at 150 ℃ by using a press. If the thickness of the product is thick, it can be extended or the temperature is increased.

Example 2

70-80 kg of wet silica in 100 kg of the high-viscosity silicone polymer of the YM type, which is the first component, and 10-15 kg of the polyorganosilixane in which the OH group, which is the second component, is present at the end, and Si-H, which is the third component 0.5 to 0.8 kg of siloxane having a group is produced by using two rolls or a kneading machine to produce silicone rubber. It is added to the platinum compound 0.005 ~ 0.015kg in a roll cooled to 25 ℃ or less to prepare a high-strength tracking resistance silicone rubber. The molding method can be used for about 10 minutes at 150 ℃ when using the dress. In the case of thick product, the time can be extended or the temperature can be increased.

Example 3

20 to 30 kg of dry silica in 100 kg of the high-viscosity silicone polymer of the WM type, which is the first component, and 1 to 4 kg of the polyorganosilixane in which the OH group, which is the second component, is present at the end, and Si-H, which is the third component Silicone rubber is manufactured by using a roll or a kneading machine with 0.1 to 0.5 kg of siloxane having a group. It is added to the platinum compound 0.05 ~ 0.08 Kg in a roll cooled to 25 ℃ or less to prepare a high strength tracking resistance silicone rubber. The molding method can be used for about 10 minutes at 150 ℃ when using the dress. In the case of thick product, the time can be extended or the temperature can be increased.

The physical properties of the present invention prepared as described above are compared with the conventional insulator silicone rubber, and are shown in Table 1.

Table 1

Conventional Insulator Silicone Rubber Insulator Silicone Rubber Composition of the Invention Specific gravity (g / cm 3) (ASTM D792) 1.55 1.20 and below Shore A 70 70 Tensile (kgf / ㎠) 40-50 More than 100 kidney (%) 100-200 200 to 400 Tearing (kgf / cm) 10 25 Flame Retardant (UL94) UL94V1 UL94V0 Insulation resistance (Ωcm) 1 × 10 ¹⁴ 1 × 10 ¹⁵ Insulation breakdown strength (kV / mm) 23 25 Tracking Resistance (IEC 587) 4.5 kV pass 4.5kV pass

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, the present invention reacted a polyorganosiloxane having a vinyl group with a polyorganosiloxane having reinforcing silica and a Si-H group under a platinum catalyst without using ATH added to a conventional insulator silicon rubber. It has physical properties and is excellent in workability.

In addition, due to the non-addition of ATH, the specific gravity is reduced compared to the conventional insulator silicone rubber, thereby reducing the weight of the insulator, and having many advantages such as having excellent heat resistance and flame retardancy compared to the conventional insulator silicone rubber. .

Claims (5)

In the silicone rubber composition for insulators; The silicone rubber composition is 100 phr of polymethyl organosiloxane of the MBM type containing at least two vinyl groups in the molecule; Polyorganosiloxane containing at least one hydroxyl (OH) bonded to a silicon atom and having a viscosity of 50 to 200 cp (centi poise) at 25 ° C., 1 to 20 phr; Reinforcing silica 5-100 phr; 0.1-10 phr of polyorganosiloxane with Si-H groups; Platinum catalyst silicone rubber composition for insulator, characterized in that consisting of 0.001 ~ 0.1 phr. The method of claim 1; The polyorganosiloxane containing two or more vinyl groups corresponds to 0.01-10 mol% of the entire organic group, has a molecular weight of 100,000 to 700,000, and an average polymerization degree of 2000 to 10,000. Silicone rubber composition. The method of claim 1; The polyorganosiloxane having the Si—H group contains at least two or more hydrogen atoms directly bonded to silicon atoms in one molecule, and is represented by the formula (1) silicone rubber composition for insulators. Formula 1 (In the formula, the substituent R ₂ is selected from methyl group, ethyl group, propyl group, phenyl group, and flor group, and m and n are 0 or a positive integer and 1 <m + n <500.) The method of claim 1; The platinum catalyst is selected from the group consisting of single platinum, H ₂ PtCl ₆ nH ₂ O, NaHPtCl ₆ nH ₂ O, PtCl ₄ , PtCl ₄ nH ₂ O, PtCl ₂ , and used to dissolve in siloxane and alcohol. Silicone rubber composition for insulator. The method of claim 1; The reinforcing silica is a silicone rubber composition for insulator, characterized in that the surface area of 100 m 2 / g or more.