JP3395456B2 - Silicone rubber composition for high voltage electrical insulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to
High voltage to give silicone rubber as high voltage electrical insulator
The present invention relates to a silicone rubber composition for an electrical insulator. [0002] BACKGROUND OF THE INVENTION Transmission lines
High-voltage electrical insulators used for insulators used in
It is made of porcelain or glass. But coastal areas
In environments that are susceptible to pollution, such as
Particles, salts, fog, etc. pass through the surface of the piezoelectric insulator
Leakage current or flashover
There is a problem that continuous dry land discharge occurs.
Was. [0003] Therefore, these porcelain or glass insulators are required.
Various solutions have been proposed to improve the rim defects
I have. For example, U.S. Pat.
Curable resin member and platinum catalyst-containing organopolicy
Roxane elastomer and weather-resistant high voltage electrical insulation
An edge has been proposed. Also, JP-A-59-19860
No. 4 discloses a one-part, room-temperature-curable organopolysiloxane.
Sun composition outside the glass or porcelain electrical insulator
Moisture, air pollution, ultraviolet rays, etc. by applying to the surface
In the presence of stress in the open air
Proposal of technology to maintain high-performance electrical performance of the edge
Have been. Further, Japanese Patent Publication No. 53-35982 and
Japanese Unexamined Patent Publication No. Hei 4-209655 discloses that a heat-curing method
Organopolysiloxane and aluminum
At a temperature higher than 100 ° C. for 30 minutes.
By heating for more than one minute to improve electrical insulation.
It has been proposed that a silicone rubber composition be obtained. [0005] However, in the above prior art,
The high voltage electrical insulation of the silicone rubber materials
Edge performance is not yet satisfactory,
Complain that it takes a long time to cure the rubber material.
Was. In addition, the conventional technology cures the silicone rubber material
When using a platinum catalyst, silicone rubber
Is considered to deteriorate the electrical insulation of the
Organic peroxide instead of addition curing method using platinum catalyst
Use of organic peroxides
Crosslinking requires a high reaction temperature and cure temperature compared to the addition curing method.
It is difficult to control the degree of
Insufficient residue remains and adversely affects the properties of the cured product.
Was profitable. The present invention has been made in view of the above circumstances,
Severe air pollution even after heating and curing even if it contains a platinum catalyst
Or weather and track resistant under weather conditions
Voltage, arcing and erosion resistance
High voltage electricity that gives silicone rubber with excellent gas insulation properties
Disclosed is a silicone rubber composition for an insulator. [0007] Means and Actions for Solving the Problems The present inventor has described
As a result of intensive studies to achieve the above objective, one molecule
Having two or more aliphatic unsaturated hydrocarbon groups
Containing silica fine powder as well as polysiloxane.
With organohydrogenpolysiloxane and platinum-based
Addition-curable silicone rubber composition cured by catalyst
Aluminum hydroxide and both ends (CH_Three)_Three
SiO_1/2Organics blocked by units and bonded to silicon atoms
The group is a monovalent hydrocarbon group excluding an aliphatic unsaturated hydrocarbon group;
A viscosity at 25 ° C. of 30 to 100,000 cp
s (centipoise) liquid organopolysiloxane
Weather resistance and tracking resistance can be achieved by blending a specified amount.
Excellent in resistance, arc resistance and erosion resistance, high voltage electricity
Gives silicone rubber with excellent insulation performance.
Rubber is useful as a high-voltage electrical insulator such as insulators.
Thus, the present invention has been accomplished. That is, the present invention provides: (A) Organopolysiloxane having two or more aliphatic unsaturated hydrocarbon groups in one molecule 100 parts by weight of sun, (B) 1-100 parts by weight of silica fine powder, (C) 50 to 300 parts by weight of aluminum hydroxide, (D) Both ends are (CH_Three)_ThreeSiO_1/2Units that are blocked in units and bonded to silicon atoms The organic group is a monovalent hydrocarbon group excluding an aliphatic unsaturated hydrocarbon group, at 25 ° C. Liquid organopolysiloxane with a viscosity of 30-100,000 cps                                                     1 to 20 parts by weight, (E) Three hydrogen atoms bonded to a silicon atom in one molecule
Organohydrogenpolysiloxane having above:
With respect to 1 mole of the unsaturated hydrocarbon group of component (A),
Supply 0.5 to 20 moles of hydrogen atoms to bond with i-atoms
Amount (F) catalytic amount of platinum-based catalyst For high-voltage electrical insulator characterized by containing
A rubber composition is provided. Hereinafter, the present invention will be described in more detail.
Constituting silicone rubber composition for Ming's high-voltage electrical insulator
The organopolysiloxane of component (A) is contained in one molecule.
Aliphatic unsaturated carbon bonded to at least two silicon atoms
Having a hydride group and represented by the following general formula (1)
Things can be used.       R¹ _aR^Two _bSiO_{(4-ab) / 2}                          … (1) Where R¹Is an aliphatic unsaturated hydrocarbon group,
As the thing, it has 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms.
, Specifically vinyl, allyl, propenyl
And the like. R^TwoIs a char without aliphatic unsaturated bond
Substituted or unsubstituted having 1 to 12 carbon atoms, especially 1 to 10 carbon atoms
A monovalent hydrocarbon group, a methyl group, an ethyl group, a propyl group,
Alkyl group and cyclohexyl group exemplified by butyl group, etc.
Exemplified by cycloalkyl group, phenyl group, tolyl group, etc.
Aryl, benzyl, phenylethyl, etc.
Illustrative aralkyl groups, 3,3,3-trifluoropro
Substituted alkyl exemplified by a pill group, a 3-chloropropyl group and the like
And a kill group. A is 0 <a ≦ 1, preferably 0.0
005 ≦ a ≦ 0.5, more preferably 0.001 ≦ a ≦
0.2, b is 0.8 <b <3, preferably 1 ≦ b <2.
5, more preferably 1.5 ≦ b <2.2, and a + b is in the range of 0.
8 <a + b <3, preferably 1.5 ≦ a + b ≦ 2.5,
More preferably, a positive number satisfying 1.8 ≦ a + b ≦ 2.2
It is. Here, the molecular structure of the component (A) is as follows:
It may be linear, branched, cyclic, or meshed
No. There is no particular limitation on the molecular weight of component (A), and the viscosity is low.
Use from liquid to high viscosity raw rubber
But can be cured to become a rubbery elastic body
Has a viscosity at 25 ° C. of 100 cps or more, usually 100 to 100 cps.
1,000,000 cps, especially 1,000-100,
000 cps is desirable. As such an organopolysiloxane,
The following are specific examples of the chain.
Can be. [0014] Embedded image In the above formula, m and p are positive integers, and n is 0
As described above, q is an integer of 2 or more, and m + n and p + q are
Each of these vinyl-containing organopolysiloxanes
It is a number to be in the above viscosity range. Organopolysilo described above
The xane may be used alone or as a mixture of two or more.
It may have a partially branched structure. As the silica fine powder of the component (B),
What is used for the silicone rubber composition of
The type is not particularly limited. Such silica fine powder
Is, for example, the specific surface area by the BET method is 50 m^Two/
g or more, especially 50 to 400 m^Two/ G precipitated silica, Hu
Fumed silica, calcined silica and average particle size of 50 μm or less
In particular, crushed quartz and diatomaceous earth of 0.1 to 20 μm are preferable.
Used appropriately. These fine powders can be used as they are.
However, organosilazanes such as hexamethyldisilazane,
Organochlorosilanes such as trimethylchlorosilane
Organopolysiloxanes such as Limethylsiloxane
Using hydrophobic silica surface-treated with organosilicon compound
It is also suitable. The amount of the component (B) is
If this component is less than 1 part by weight per 100 parts by weight,
Strength is weakened, and if it exceeds 100 parts by weight, component (C)
Aluminum hydroxide is difficult to fill
You. Therefore, the compounding amount of the component (B) is 100% of the component (A).
The amount is 1 to 100 parts by weight with respect to parts by weight.
The amount is preferably 2 to 50 parts by weight. Next, the aluminum hydroxide of the component (C)
Is to improve the arc resistance and tracking resistance of silicone rubber.
It is used to improve
It is a thing of Su. Aluminum hydroxide has the following formula
(2)       Al_TwoO_Three・ 3H_TwoO ... (2) Which is expressed as aluminum hydroxide.
Uniform particle size is 10 μm or less, preferably 0.1 to 10 μm
m, more preferably 0.5 to 9 μm. This aluminum hydroxide is used as it is.
Or silane or titanate coupling.
Dimethylpolysiloxane oil or steer
Those surface-treated with phosphoric acid or the like may be used. (C)
Per 100 parts by weight of component (A)
Is less than 50 parts by weight, the cured composition requires an arc resistant
And tracking resistance cannot be obtained.
If the amount is more than 10 parts by weight, it becomes difficult to fill the composition, and
Gets worse. Therefore, the compounding amount of the component (C) is
50 to 300 parts by weight for 100 parts by weight
And preferably in an amount of 150 to 250 parts by weight.
You. The component (D) is a liquid organopolysilo.
Xane improves the weather resistance and tracking resistance of the composition
It is an essential component of the present invention.
You. This liquid organopolysiloxane is as described above.
In addition, the organic group bonded to the silicon atom is an aliphatic unsaturated hydrocarbon
Is a monovalent hydrocarbon group excluding an amino group, and both ends are (C
H_Three)_ThreeSiO_1/2Basically, the unit is closed.
Has a chain diorganopolysiloxane structure
May have a partially branched structure,
Viscosity at 25 ° C. is 30 to 100,000 cps, preferably
Is 100 to 100,000 cps, particularly preferably 1,
000 to 50,000 cps. This liquid
Luganopolysiloxane is represented by the following general formula (3).
Is preferably used. [0020] Embedded image Where R^Three, R^FourAre aliphatic unsaturated carbons
A monovalent hydrocarbon group excluding a hydride group;^Three, R^FourAre
They may be the same or different. Aliphatic unsaturation
Monovalent hydrocarbon groups other than hydrocarbon groups include methyl
Group, ethyl group, propyl group, butyl group, cyclohexyl
Alkyl group having 1 to 8 carbon atoms such as group, phenyl group, tolyl
And an aryl group having 6 to 12 carbon atoms such as a group.
However, particularly in the present invention, an alkyl group represented by a methyl group is
preferable. In addition, r represents this organopolysiloxane
It is a number to be the viscosity. The amount of the component (D) is as follows:
If this component is less than 1 part by weight based on 00 parts by weight,
The composition cannot obtain the required weather resistance and tracking resistance
Rubber elastic body which is cured when it exceeds 20 parts by weight
Of the composition is wetted by the organosiloxane
Workability deteriorates. Therefore, the compounding amount of the component (D) is
1 to 20 parts by weight per 100 parts by weight of component (A)
In such an amount, preferably 3 to 10 parts by weight.
Amount. (E) Component organohydrogenpoly
Siloxane is a crosslinking agent for the silicone rubber composition of the present invention.
And in the presence of the platinum catalyst of the component (F), the component (E)
The silicon-bonded hydrogen atom (ie, SiH group) of (A)
Reaction of silicon-bonded aliphatic unsaturated hydrocarbon groups
As a result, it is crosslinked and hardened. this
(E) Component organohydrogenpolysiloxane
Is represented by the following general formula (4)       R^Five _dH_eSiO_{(4-de) / 2}                          … (4) (Where d is 0.5 <d <2.5, preferably 0.
8 <d ≦ 2, e is 0 <e ≦ 1, preferably 0.001 <
e ≦ 0.5, d + e is 0.8 <d + e ≦ 3, preferably
It is a positive number satisfying 1.5 ≦ d + e ≦ 2.5. )
At least three silicon atoms per molecule
It is necessary to have a hydrogen atom that bonds to Silicon
Organic group R other than atom-bonded hydrogen atom^Five As methyl
Group, an ethyl group, an alkyl group exemplified by a propyl group,
A cycloalkyl group of cyclohexyl group, a phenyl group,
Aryl group, benzyl group, phenyl group
Aralkyl groups such as ruethyl group, 3,3,3-trifluoro
Substitution exemplified by a propyl group, a 3-chloropropyl group and the like
The above R such as an alkyl group;^TwoRemove the same aliphatic unsaturated groups as
Unsubstituted or substituted with 1 to 12 carbon atoms, especially 1 to 10 carbon atoms
And substituted monovalent hydrocarbon groups. Here, the component (E)
Organohydrogenpolysiloxane as molecular structure
May be linear, branched, cyclic, or mesh-like.
good. (E) Component organohydrogenpolysiloxane
Sun has a viscosity at 25 ° C of 1 to 10,000 cps,
More preferably, it is in the range of 3 to 5,000 cps.
Are exemplified below. [0024] Embedded image Where s, t and u are positive integers and v
Is an integer of 3 or more, and s + t and u + v are
These organohydrogenpolysiloxanes have the above viscosity.
The number to be ranged. The organohydrogen of the component (E)
The compounding amount of the polysiloxane in the composition is as follows:
Of the silicon-bonded unsaturated hydrocarbon group of
With the number of moles of silicon-bonded hydrogen atoms (ie, SiH groups)
The amount is such that the ratio is 1: 0.5 to 1:20, and is preferably
The amount is preferably 1: 1 to 1: 3. this is,
Number of moles of silicon-bonded unsaturated hydrocarbon group of component (A)
The number of moles of silicon-bonded hydrogen atoms of this component is 1
If it is less than 0.5, the silicone rubber composition is sufficiently cured.
Cannot be achieved, and if it exceeds 20, the silicone rubber composition
This is because foaming may occur. [0027] The platinum catalyst of the component (F) is silicone rubber.
A catalyst for curing the rubber composition. This (F)
Chloroplatinic acid, chloroplatinic acid, etc.
Solution solution, complexation of chloroplatinic acid and olefins
Products, platinum black, platinum-supported products, etc.
Known as a catalyst for the relation reaction
Is included. The addition amount of the component (F) is a catalyst amount,
Usually, platinum gold is added to the total amount of 1,000,000 parts by weight of the total composition.
0.1 to 1,000 parts by weight as a genus, preferably
It is 1 to 500 parts by weight. This is less than 0.1 parts by weight
If the curing does not proceed sufficiently and exceeds 1,000 parts by weight
Because it is uneconomic. The silicone rubber composition of the present invention is
Various additives depending on the purpose, for example, titanium oxide
, Iron oxide, cerium oxide, vanadium oxide, black oxide
Metal oxides such as metals
Pigments, heat-resistant agents, flame retardants, plasticizers, etc.
It may be added. The silicone rubber composition of the present invention is
The components (A) to (F) and optional components are uniformly mixed at room temperature.
Can be obtained simply by
The components (A) to (D) and optional components are
Heat treatment at 100-200 ° C for 2-4 hours with a kneader
Then, the components (E) and (F) are mixed and cured and molded.
May be. The molding method can be freely selected according to the viscosity of the mixture
Can be injection molding, compression molding, injection molding or
Any of transfer molding and the like may be used. The curing is usually performed at 80 to 200 ° C. for 3 minutes to
It can be performed by heating for 3 hours. [0031] EFFECT OF THE INVENTION The silicone for high-voltage electrical insulation of the present invention
According to the rubber composition, it is conventionally inferior to the inclusion of the platinum-based catalyst.
Electrical insulation of silicone rubber composition
Can be improved, and even if a platinum-based catalyst is contained,
Weather resistance, water repellency,
Silicon with excellent high-voltage electrical characteristics such as tracking resistance
Rubber can be given. [0032] The following examples and comparative examples illustrate the present invention.
Although described in detail, the present invention is limited to the following examples.
Not something. [Examples 1 to 3] (A) Both ends are sealed with dimethylvinylsiloxy groups
Chained dimethylpolyester having a viscosity of 5,000 cps at 25 ° C.
Lisiloxane, (B) silica fine powder (Nipsil LP, Japan
BET specific surface area 180m^Two/ G),
(C) Average particle diameter 8 μm, BET specific surface area 2 m^Two/ G
Aluminum hydroxide, (D) both ends are trimethyl
The viscosity at 25 ° C. blocked with a lusiloxy group is 30,000.
cps dimethylpolysiloxane, (E) the following formula (5)
A methylhydrogensiloxane represented by the formula (F):
1% solution of chloroplatinic acid in 2-ethylhexanol
(G) Ethynylcyclohexanol in the amount shown in Table 1
First, the components (A) to (D) are used at room temperature (25 ° C).
Stir and mix with a planetary mixer, then
Add component (E), component (F) and component (G) and add at room temperature.
The mixture was uniformly mixed to obtain a silicone rubber composition. This composition
After heating and curing at 120 ° C for 10 minutes,
Next cured, each 128mm × 44mm × 6mm
A (thickness) silicone rubber sheet was obtained. [0034] Embedded image Example 4 The same components as in Examples 1 to 3
Used, stirring components (A)-(D) at 150 ° C. for 2 hours,
Except for mixing, silicone rubber was prepared in the same manner as in Examples 1-3.
I got a musheet. [Comparative Examples 1 and 2] The components shown in Table 1 were used.
Then, a silicone rubber sheet was obtained in the same manner as in Example 4.
Was. [Comparative Example 3] (A) similar to Examples 1-3
To (C) components, and (A) to (C) components at 150 ° C.
After stirring for 2 hours and cooling to room temperature,
0.6 g of dicumyl peroxide as an organic peroxide
Heating and curing in the same manner as in Examples 1 to 3 except for adding and mixing
Thus, a silicone rubber sheet was obtained. Next, the silicon oxides obtained in the above Examples and Comparative Examples were used.
Tracking test for cone rubber sheet by the following method
Was measured. Table 1 shows the results.Tracking test method Performed according to the standard of ASTM D-2303-64T
Was. That is, contamination is performed at a load voltage of 4 kV and a distance between the electrodes of 50 mm.
Dyeing solution (0.1% NH_FourCl and 0.02% nonionic surfactant
Aqueous solution of the active agent) at a rate of 0.6 ml / min.
The time from when a track is generated and turned on after dripping from
And the resulting erosion weight loss was measured. [0039] [Table 1]From the results shown in Table 1, the silicone rubber of the present invention was obtained.
The composition gives silicone rubber with excellent tracking properties.
However, even when compared to organic peroxide curing type
It is recognized that the air insulation is not inferior.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-41348 (JP, A) JP-A-7-57574 (JP, A) JP-A-5-105814 (JP, A) JP-A-63- 193413 (JP, A) JP-A-57-151650 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 83/00-83/16 C08K 3/00-13/08

Claims (1)

(57) Claims: (A) 100 parts by weight of an organopolysiloxane having two or more aliphatic unsaturated hydrocarbon groups in one molecule, (B) 1 to 100 parts by weight of a fine silica powder Part, (C) 50 to 300 parts by weight of aluminum hydroxide, (D) both ends are blocked with (CH ₃ ) ₃ SiO _1/2 units, and the organic group bonded to the silicon atom is an aliphatic unsaturated hydrocarbon group. (E) 1 to 20 parts by weight of a liquid organopolysiloxane having a viscosity of 30 to 100,000 cps at 25 ° C. which is a monovalent hydrocarbon group excluding (E) three or more hydrogen atoms bonded to a silicon atom in one molecule Organohydrogenpolysiloxane having: an amount of supplying from 0.5 to 20 moles of the hydrogen atom bonded to the silicon atom to 1 mole of the unsaturated hydrocarbon group of the component (A), and (F) a catalytic amount of platinum-based Including catalyst High-voltage electrical insulating-body silicone rubber composition, characterized by.