JPH06256637A - Gasket - Google Patents

Abstract

PURPOSE:To provide a gasket excellent in mechanical properties. CONSTITUTION:This gasket is made from a curable composition mainly consisting of a polyoxypropylene polymer having at least one alkenyl group in the molecule, a compound having at least two hydrosilyl groups in the molecule, a hydrosilylation catalyst, a fine silica powder, and a storage stability improver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket, and more particularly to a gasket used for the purpose of sealing liquid or gas or absorbing shock.

[0002]

2. Description of the Related Art As a gasket, conventionally, various synthetic rubbers mixed with a filler and vulcanized and molded into a sheet have been used, but the cost for equipment and power for kneading is large, In addition, there is a problem that the performance is not sufficient.

[0003]

DISCLOSURE OF THE INVENTION The present invention comprises a so-called liquid rubber, which can be kneaded in a liquid state with a filler or the like, is excellent in molding processability, and is molded from a curable composition having sufficient mechanical properties. The present invention is to provide a gasket that has been made.

[0004]

The gasket of the present invention comprises:
It is formed from a curable composition containing the following five components (A) to (E) as main components. (A) a polyoxypropylene-based polymer having at least one alkenyl group in the molecule, (B) a compound having at least two hydrosilyl groups in the molecule, (C) a hydrosilylation catalyst,
(D) Silica fine powder, and (E) Storage stability improver.

The polyoxypropylene polymer having at least one alkenyl group in the molecule which is the component (A) of the present invention is a polymer whose main chain is mainly oxypropylene, and which is linear or branched. Any number is preferable, and the number average molecular weight is preferably 500 to 50,000,
Particularly preferably, it is from 00 to 20,000. If the number average molecular weight is less than 500, sufficient mechanical properties cannot be obtained when the composition of the present invention is used as a cured product. However, if the molecular weight is too large, curing will be insufficient and sufficient mechanical properties will not be obtained. Furthermore, the average molecular weight is 6,000.
Among the above, those having a dispersity (M _w / M _n ) of 1.5 or less have a low viscosity before curing, are easy to handle, and exhibit good rubber-like elastic behavior after curing. From the point of, it is preferable. The alkenyl group contained in this polyoxypropylene polymer is not particularly limited, but it is of the formula (I): H ₂ C = C (-R ¹ ) − (I) (wherein R ¹ Is preferably a hydrogen atom or a methyl group).

Specific examples of the polyoxypropylene polymer having at least one alkenyl group in the molecule which is the component (A) of the present invention include polymers represented by the following formula. You can First, the following formula (II)
There is a polymer represented by. [H ₂ C = C (-R ¹ ) -R ² -O] _a R ³ (II)

(Wherein R ¹ Is hydrogen or a methyl group, R ² Is a divalent hydrocarbon group having 1 to 20 carbon atoms and may contain one or more ether groups, and R ³ Is a polyoxypropylene polymer and a is a positive integer. ) This R
² As is _{specifically, -CH 2 -, - CH 2} CH 2
_{-, - CH 2 CH 2 CH} 2 -, - CH 2 CH (CH 3)
_{CH 2 -, - CH 2 CH} 2 CH 2 CH 2 -, - CH 2 C
_{H 2 OCH 2 CH 2 -,} - CH 2 CH 2 OCH 2 CH 2
Although CH ₂ — can be mentioned, —CH ₂ — is preferable from the viewpoint of ease of synthesis. Next, there is a polymer having an ester bond represented by the following formula (III). [H ₂ C = C (-R ¹ ) -R ² -OC (= O)] _a R ³ (III) (In the formula, R ¹ , R ² , R ³ , And a are the same as above. ) Further, there is a polymer represented by the following formula (IV). [H ₂ C = C (-R ¹ )] _A R ³ (IV) (In the formula, R ¹ , R ³ , And a are the same as above. ) Further, there is a polymer having a carbonate bond represented by the following formula (V). [H ₂ C = C (-R ¹ ) -R ² -OC (= O) O] _a R ³ (V) (In the formula, R ¹ , R ² , R ³ , And a are the same as above. )

As the method of introducing an alkenyl group into the polyoxypropylene polymer as the component (A) of the present invention, various proposed methods can be used.
For example, a polyoxypropylene polymer having a functional group such as a hydroxyl group or an alkoxide group at the terminal, main chain or side chain is reacted with an organic compound having an active group and an alkenyl group reactive with the above functional group. By doing so, an alkenyl group can be introduced into the terminal, main chain or side chain.

Examples of the organic compound having an active group and an alkenyl group reactive with the above functional group include C _{2 to} C ₂₀ such as acrylic acid, methacrylic acid, vinyl acetic acid, acrylic acid chloride and acrylic acid bromide. Unsaturated fatty acids, acid halides, acid anhydrides, C _{3 to} C ₂₀ unsaturated fatty acid-substituted carbonic acid halides such as allyl chloroformate, allyl bromoformate, allyl chloride, allyl bromide, vinyl (chloromethyl) benzene, allyl (Chloromethyl) benzene, allyl (bromomethyl) benzene, allyl (chloromethyl) ether, allyl (chloromethoxy) benzene, 1-butenyl (chloromethyl) ether, 1-hexenyl (chloromethoxy) benzene, allyloxy (chloromethyl) benzene Etc.

The polyoxypropylene polymer can be obtained by a usual polymerization method of oxypropylene (anionic polymerization using caustic alkali) or a chain extension reaction method using this polymer as a raw material. Further, a polyoxypropylene polymer having a high molecular weight and a narrow molecular weight distribution and having a functional group is disclosed in JP-A-61-197631, JP-A-61-215622, JP-A-61-215623, and JP-A-61-215623. It can be obtained by the methods described in JP-A-61-218632, JP-B-46-27250 and JP-B-59-15336.

The compound having at least two hydrosilyl groups in the molecule, which is the component (B) of the present invention, is not particularly limited, but specific examples of the group containing a hydrosilyl group include the following groups. Can be mentioned.

For example, --Si (H) _n (CH ₃ ) _3-n ,
_{-Si (H) n (C 2} H 5) 3-n, -Si (H) n (C
₄ H ₆ ) _3-n , [n = 1 to 3], -SiH ₃ (C
₆ H ₁₂ ) etc., a hydrosilyl group containing only one silicon atom, —Si (CH ₃ ) ₂ Si (CH ₂ ) ₂ H, —Si
_{(CH 3) 2 CH 2 CH} 2 Si (CH 3) 2 H, -Si
_{(CH 3) 2 SiCH 3 H} 2, -Si (CH 3) 2 -P
_{h-Si (CH 3) 2} H [Ph is p- phenylene, -
_{Si (CH 3) 2 NHSi (} CH 3) 2 H, -Si (C
_{H 3) 2 N [Si (} CH 3) 2 H] 2, -Si (C
_{H 3) 2 OC (CH 3} ) = NSi (CH 3) 2 H, -S
i (CH ₃ ) ₂ N = C (CH ₃ ) OSi (CH ₃ ) ₂ H
Silicon atom two containing group such _{as, - (- SiR 2 -O-)} m
_{- (- SiR 2 -O-) n} H

[Wherein R is a group selected from H, -OSi (CH ₃ ) ₃ and an organic group having 1 to 10 carbon atoms, and each R may be the same or different, and m and n
Is a positive integer and 2 ≦ m + n ≦ 50. ], -SiR [(-O-SiHR-) _m- R] [-(-O-
SiHR-) _n R] [wherein, R, m and n are as defined above. ] -SiR [(- O-SiHR- ) m - (- O-SiR 2
_{-) p R] [(-} O-SiHR-) n - (- O-SiR
₂ −) _q R] [wherein, R is the same as above, m is a positive integer, n, p and q
Is 0 or a positive integer, and 1 ≦ m + n + p + q ≦ 50. ]

[0014]

[Chemical 1] [In the formula, R is the same as above, m is a positive integer, n is 0 or a positive integer, and 2 ≦ m + n ≦ 50. ] And other groups derived from various linear, branched, or cyclic polyvalent hydrogen siloxanes and the like.

Of these various hydrosilyl groups, the molecular weight of the group constituting the hydrosilyl group is 500 or less from the viewpoint that the compatibility of the hydrosilyl group-containing compound of the present invention with the component (A) is less likely to occur. The following groups are preferable in view of the reactivity of the hydrosilyl group.

[0016]

[Chemical 2] [In the formula, p is a positive integer, q is 0 or a positive integer, and 2
≦ p + q ≦ 4. ]

[0017]

[Chemical 3]

In the component (B) compound of the present invention, when two or more hydrosilyl group-containing groups are present in the same molecule, they may be the same or different.
The total number of hydrosilyl groups contained in the component (B) may be at least 2 in one molecule, but is preferably 2 to 15, and particularly preferably 3 to 12. In the presence of a hydrosilylation catalyst, the hydrosilyl group-containing compound [(B) component] of the present invention is
When mixed with a polymer having an alkenyl group [component (A)] and cured by a hydrosilylation reaction, a curing failure often occurs when the number of the hydrosilyl groups is less than 2. Further, if the number of the hydrosilyl groups is more than 15, the stability of the component (B) is deteriorated, and moreover, a large amount of the hydrosilyl groups remains in the cured product even after curing, causing voids and cracks.

The hydrosilyl group-containing compound of the component (B) of the present invention is not particularly limited, but various compounds having a low molecular weight to polymers can be used. These are specifically illustrated. Formula (VI)

[0020]

[Chemical 4]

[Wherein X is a group having at least one of the above hydrosilyl groups, and R ¹ , R ² And R ³ Is the formula (II)
At R ¹ , R ² And R ³ And a is an integer. ] A compound having an ether bond represented by the formula (VII)

[0022]

[Chemical 5]

[Wherein, X is a group having at least one of the above hydrosilyl groups, and R ¹ , R ² And R ³ Is the formula (II
R ¹ in I) , R ² And R ³ Are the same as
Is an integer. ] A compound having an ester bond represented by the formula: (VIII)

[0024]

[Chemical 6]

[Wherein, X is a group having at least one of the above hydrosilyl groups, and R ¹ And R ³ Is R ¹ in formula (III) And R ³ And a is an integer. ] A hydrocarbon compound represented by the formula (IX)

[0026]

[Chemical 7]

[In the formula, X is a group having at least one of the above hydrosilyl groups, and R ¹ , R ² And R ³ Is R ¹ in formula (V) , R ² And R ³ And a is an integer. ] The compound which has a carbonate bond represented by these can be mentioned.

When an organic polymer is used as the component (B) of the present invention, the polymer may be linear or branched, and any one having a molecular weight of 500 to 50,000 can be preferably used, but 500 Those of ˜20,000 are particularly preferred.
The hydrosilyl group contained in the component (B) may be at the molecular end or in the molecule, but when a rubber-like cured product is produced using the composition of the present invention, it is better to be at the molecular end. It is preferable because the effective network chain length becomes long.

The method for producing the component (B) compound of the present invention is not particularly limited, and any method can be used. For example, (i) a method of treating an organic compound having a Si—Cl group in the molecule with a reducing agent such as LiAlH ₄ or NaBH ₄ to reduce the Si—Cl group of the compound to a Si—H group,
i) a method of reacting an organic compound having a functional group X in the molecule with a compound having a functional group Y that reacts with the functional group in the molecule and a hydrosilyl group at the same time, (iii) for an organic compound having an alkenyl group A method is conceivable in which a polyhydrosilane compound having at least two hydrosilyl groups is selectively hydrosilylated to leave the hydrosilyl group in the molecule of the compound after the reaction. this house
The method (iii) is particularly preferable.

As the hydrosilylation catalyst which is the component (C) of the present invention, a simple substance of platinum, a simple substance of alumina, silica, carbon black or the like on which solid platinum is supported, chloroplatinic acid, chloroplatinic acid and alcohol, Complexes with aldehydes, ketones, etc., platinum-olefin complexes (eg Pt (C
_{H 2 = CH 2) 2 (} PPh 3) 2 Pt (CH 2 = C
H ₂ ) ₂ Cl ₂ ), platinum-vinylsiloxane complex (for example, Pt _n (ViMe ₂ SiOSiMe ₂ Vi) _m , P
t [(MeViSiO) ₄ ] _m ), platinum-phosphine complex (for example, Pt (PPh ₃ ) ₄ , Pt (PB)
u _{3) 4),} platinum - phosphite complex (e.g., Pt
[P (OPh) ₃ ] ₄ ) [wherein, Me is a methyl group, B
u is a butyl group, Vi is a vinyl group, Ph is a phenyl group, m and n are integers], dicarbonyldichloroplatinum and also described in Ashby US Pat. Nos. 3,159,601 and 3,159,662. Platinum-hydrocarbon composites, as well as Lamoreaux U.S. Pat. No. 3,22.
Platinum alcoholate catalysts as described in 0,972 are also mentioned. In addition, Modic US Patent 3,5
The platinum chloride-olefin composites described in 16,946 are also useful in the present invention.

Examples of catalysts other than platinum compounds include RhCl (PPh ₃ ) ₃ , RhCl ₃ and RhAl _2.
O ₃ , RuCl ₃ , IrCl ₃ , FeCl ₃ , AlCl
₃ , PdCl ₂ .2H ₂ O, NiCl ₂ , TiCl _{4 and the} like. These catalysts may be used alone,
It is also possible to use two or more types in combination. From the viewpoint of catalytic activity, chloroplatinic acid, platinum-olefin complex, platinum-acetylacetonate complex, and platinum-vinylsiloxane complex are preferable.

The amount of the catalyst which is the component (C) of the present invention is not particularly limited, but the alkenyl group 1 in the component (A) is 1
It is preferable to use it in the range of 10 ^-1 to 10 ^-8 mol per mol. It is preferably used in the range of 10 ⁻³ to 10 ⁻⁶ mol. If it is less than 10 ^-8 mol, curing will not proceed sufficiently. Further, the hydrosilylation catalyst is generally expensive and corrosive, and since hydrogen gas may be generated in a large amount and the cured product may foam, it is better not to use 10 ^-1 mol or more.

In the present invention, a noble metal catalyst is used,
Since the curable composition is cured by the addition reaction of the Si-H group to the alkenyl group, the curing rate is very fast, which is convenient for line production.

As the silica fine powder which is the component (D) of the present invention, hydrous silica obtained by a wet production method such as hydrolysis of sodium silicate, and thermal decomposition of a silicon halide such as silicon tetrachloride or an organic silicon compound. It is possible to use anhydrous silica obtained by the dry production method or the like. Examples of the water-containing silica include Nipseal VN3, Nipseal AQ, Nipseal LP, manufactured by Nippon Silica Industry Co., Ltd.
Nip seal ER, nip seal NS, nip seal N
ST, Nipseal NA, Nipseal L300, Nipseal N300A, Nipseal E, Monsanto
Hi-Sil 2 from Santocel FRC, Santocel CS, PPG Ind
33, Hi-Sil X-303, Quso F-2 from Philadelphia Quarts
0 and the like.

Examples of the anhydrous silica include Aerosil 130, Aerosil 200, Aerosil 200V, Aerosil 200CF, Aerosil 300, Aerosil 300CF, Aerosil 380, Aerosil OX50, Aerosil TT600, Aerosil MOX80, Aerosil MOX170, Aerosil manufactured by Nippon Aerosil Co., Ltd. COK84, Aerosil R972, Aerosil R974, Aerosil R202, Aerosil R805, Aerosil R812, Cobo
Cab-O-Sil MS-5, Cab-O-Sil MS-7, Cab-O-Sil HS from Company t
-5, Cab-O-Sil HS-7 and the like.

Among these, anhydrous silica is particularly preferable because a side reaction may occur during the curing reaction when the composition contains a large amount of water. Further, those obtained by subjecting the surface of anhydrous silica to a hydrophobic treatment (for example, Aerosil R972, Aerosil R974, Aerosil R202, Aerosil R805, Aerosil R812 and the like) are particularly preferable because they easily exhibit fluidity suitable for molding.

The fine silica powder is added in an amount of 1 per 100 parts by weight of the component (A) in order to adjust the viscosity suitable for molding.
It is preferably ˜100 parts by weight, particularly preferably 10 to 60 parts by weight. If the amount added is too small, sufficient strength may not be obtained, and the viscosity may be too low to allow molding. On the other hand, if the amount added is too large, the viscosity will increase so much that handling will become difficult and sufficient mechanical properties may not be obtained.

The storage stability improver which is the component (E) of the present invention is added to improve the storage stability of the composition, and is known as the storage stabilizer of the component (B). Any ordinary stabilizer may be used as long as it achieves the intended purpose and is not particularly limited. Specifically, a compound containing an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, a tin compound, an organic peroxide and the like can be preferably used. Specific examples thereof include benzothiazole, thiazole, dimethylmalate, 2-pentenenitrile, and 2,3-dichloropropene. Thiazole and benzothiazole are particularly preferable in terms of compatibility of pot life / fast curing property, It is not limited to these. The amount of the storage stability improver to be used can be selected almost arbitrarily as long as it is uniformly dispersed in the component (A) and the component (B). It is preferably used in the range of 10 ^-6 to 10 ^-1 mol. When the amount is less than 10 ^-6 , the storage stability of the component (B) is not sufficiently improved, and when it exceeds 10 ^-1 mol, curing may be hindered. The storage stability improvers may be used alone or in combination of two or more.

Further, if necessary, other fillers, antioxidants, plasticizers, ultraviolet absorbers, pigments, surfactants and the like can be appropriately added to the curable composition of the present invention. Specific examples of the filler include, for example, calcium carbonate, clay, talc, titanium oxide, zinc oxide, diatomaceous earth,
Examples thereof include barium sulfate and carbon black.

In the present invention, various commonly used molding methods can be used for molding the curable composition into a gasket. For example, cast molding, compression molding, transfer molding, injection molding, extrusion molding, rotary molding, blow molding, thermoforming and the like can be mentioned. In particular, injection molding is preferable because it can be automated and continuous and is excellent in productivity.

The gasket of the present invention can be used as a so-called standard gasket as a gasket used for equipment such as a flange portion of a pipe, a fastening portion of a casing, and a case where a container and a lid are joined. Also,
Can be used as a sealing or sealing packing material,
It can also be used for so-called O-rings. Furthermore, since the gasket of the present invention is a viscous liquid before hardening, it is applied to the screw part or the flange surface and tightened, and then hardened to form an elastic film, It can also be used as a so-called hardening type gasket, which can prevent liquid or gas from leaking from the joint.

[0042]

EXAMPLES Next, the composition of the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Synthesis Example 1 In this example, polyoxypropylene having an allyl-type olefin group at the terminal was synthesized according to the method disclosed in JP-A-53-134095.

Polyoxypropylene glycol having an average molecular weight of 3000 and powdered caustic soda were stirred at 60 ° C., and bromochloromethane was added to carry out a reaction to increase the molecular weight. Next, allyl chloride was added, and the terminal was allyl etherified at 110 ° C. This was treated with aluminum silicate to synthesize a purified terminal allyl etherified polyoxypropylene.

The number average molecular weight of this polyether is 796.
It was 0, and 92% of the terminal from the iodine value was an olefin group. Viscosity measured by E-type viscometer is 130 poise (40 ℃)
Met. Synthesis example 2

A 200 mL four-necked flask equipped with a three-way cocked cooling tube, a pressure-equalizing dropping funnel, a thermometer, a magnetic tip, and a glass stopper was prepared. In a nitrogen atmosphere, the following formula

[0046]

[Chemical 8]

12.30 of cyclic polyhydrogen siloxane (LS 8600 manufactured by Shin-Etsu Chemical Co., Ltd.) represented by
The flask was charged with g (50 mmol) and 20 mL of toluene. 2.76 g (20 mmol) of 1,9-decadiene, chloroplatinic acid catalyst solution (H ₂ PtCl ₆ · 6H ₂ O
1 g of ethanol and 1 g of ethanol and 9 g of 1,2-dimethoxyethane
A solution obtained by dissolving 20 μL of the above solution) in 30 mL of toluene was charged into the dropping funnel. The flask was placed in an oil bath at 50 ° C., and the toluene solution was dropped into the flask over 2 hours under a nitrogen atmosphere. When the IR spectrum was measured when the reaction was further continued at 50 ° C. for 1 hour after the completion of the dropping, the absorption of the olefin around 1640 cm ⁻¹ had completely disappeared, so the reaction was terminated at this point. After the reaction, the toluene solution was washed with a saturated aqueous solution of ammonium chloride (100 mL × 2) and ion-exchanged water (100 mL × 1), and dried with Na ₂ SO ₄ . Na ₂ SO ₄ was filtered off, benzothiazole (13 μL, 0.12 mmol) was added and volatiles were removed by evaporation, then 8
By degassing under reduced pressure at 0 ° C., 9.11 g of a colorless transparent liquid was obtained. The hydrosilyl group in the hydrocarbon compound was confirmed as a strong absorption at 2170 cm ^-1 . Also, 3
From the intensity ratio of the proton of the Si- H and Si-C H ₃ by NMR of 00MHz, the compound on average the following structural formula

[0048]

[Chemical 9] Was found to be a mixture [n = 0-2]. S
The i-H value was 0.769 mol / 100 g. Synthesis example 3

Bisphenol A 114 g (0.5 mol), 5N sodium hydroxide aqueous solution 250 mL (1.25
And 575 mL of ion-exchanged water were mixed well. Next, as a phase transfer catalyst, benzyltriethylammonium chloride

[0050]

[Chemical 10]

7.78 g (25 mmol) of was added.
242 g (2.0 mol) of allyl bromide was added to the aqueous solution.
Gradually add the solution dissolved in 300 mL of toluene from the dropping funnel.
Was added dropwise. The reaction was carried out at 80 ° C. for 2 hours with stirring.
At this point the pH of the water layer was measured and it was acidic
Then, the heating and stirring were stopped. After washing the organic layer with sodium bicarbonate water,
Further wash with ion-exchanged water,₂SO_FourDried in.
After removing volatiles by evaporation, 2 at 80 ° C
By drying under reduced pressure for an hour, a pale yellow viscous liquid 14
6 g (yield 95%) was obtained. This viscous liquid contains elemental
Analysis, 300 MHz ¹H-NMR, IR spectrum, etc.
By definition, it is a diallyl ether of bisphenol A.
It was confirmed.

IR (neat) cm ^-1 , 3070 (m, ν
= C-H), 3030 (m), 2960 (s), 292
0 (s), (ν = C−H), 1645 (m, ν = C−)
H), 1620 (s), 1520 (s), 1290
(S), 1235 (s), 1180 (s), 1025
(S), 1000 (s), 920 (s), 825 (s) Elemental analysis: calculated value C: 81.78%, H: 7.84
% Measured value C: 81.9%, H: 7.96% Synthesis example 4 A 200 mL four-necked flask equipped with a stirring bar, a dropping funnel, a thermometer, a three-way cock, and a condenser was prepared. Then, in a nitrogen atmosphere,

[0053]

[Chemical 11]

Cyclic hydrogen polysiloxane represented by
12.03 of Xan (Shin-Etsu Chemical Co., Ltd., LS 8600)
g (50 mmol) and 20 mL of toluene in a flask
I prepared it. Bisphenol A Diary Synthesized in Synthesis Example 3
6.16 g (20 mmol) of luether, chloroplatinic acid catalyst
Medium solution (H₂PtCl₆・ 6H₂1.0 g of O is ethanol
Dissolved in 9 g of 1,2,2-dimethoxyethane (1/9 v / v)
Dissolve 41 μL in 50 mL of toluene and mix well.
After mixing, the mixture was placed in the dropping funnel. Torue at 70 ℃
Solution was added dropwise to the flask over 1.5 hours. Further
When the reaction was carried out at 80 ° C for 5 hours, the IR spectrum was taken.
1645 cm^-1Adsorption derived from nearby olefins
The yield had completely disappeared, so the reaction was terminated at this point.
It was Add dimethyl acetylene dicarboxylate to the reaction mixture.
(34 μL, 0.24 mmol) was added,
After distilling off the ene under reduced pressure, dry it under reduced pressure at 80 ° C for 1 hour
12.0 g of a pale yellow viscous liquid was obtained. this
Viscous liquid is 300MHz ¹H-NMR, IR spectrum
The structural formula of

[0055]

[Chemical 12] It was found to be an Si-H group-containing ether compound having Calculated number of Si-H groups is 0.52 mol / 1
It was 00 g. Synthesis Example 5 A 200 mL four-necked flask equipped with a cooling pipe with a three-way cock, a pressure-equalizing dropping funnel, a thermometer, a rotor, and a glass stopper was prepared. The following formula under nitrogen atmosphere

[0056]

[Chemical 13]

12.30 of cyclic hydrogen polysiloxane represented by (LS 8600 manufactured by Shin-Etsu Chemical Co., Ltd.)
The flask was charged with g (50 mmol) and 20 mL of toluene. The following formula

[0058]

[Chemical 14]

Diethylene glycol diallyl carbonate represented by (Mitsui Petrochemical Co., Ltd., RAV-7N)
5.49 g (20 mmol), chloroplatinic acid catalyst solution (H
1.0 g of ₂ PtCl ₆ .6H ₂ O was added to ethanol / 1,2-
A solution prepared by dissolving 41 μL of dimethoxyethane (1/9 v / v) dissolved in 9 g) in 50 mL of toluene was placed in the dropping funnel. Attach the flask to an oil bath at 50 ° C., and put the toluene solution into the flask under a nitrogen atmosphere.
It dripped over 5 hours. When the IR spectrum was measured after the dropping was completed, the absorption of the olefin near 1640 cm ^-1 had completely disappeared, so stirring was stopped at this point. Dimethyl acetylenediallyl carboxylate (34 μL, 0.24 mmol) was added to the reaction mixture, which was then evaporated to remove volatiles, yielding 10.2 g of a slightly viscous pale yellow liquid. The hydrosilyl group of the carbonate compound has an IR spectrum of 2170.
Confirmed as strong absorption at cm ^-1 . Also, 300MHz
By comparing the intensity ratio (measured value = 0.181) of the protons of Si— H and Si—C H ₃ with the calculated NMR of the compound, the compound is averaged to the following structural formula:

[0060]

[Chemical 15] Was found to have. Based on this, Si in unit weight
The number of —H groups was calculated to be 0.47 mol / 100 g. Examples 1-7, comparative example

Organic Polymer Obtained in Synthesis Example 1, Synthesis Examples 2, 4
Alternatively, the Si-H group-containing compound obtained in 5, silica fine powder (manufactured by Nippon Aerosil Co., Ltd.), a storage stability improver, an antioxidant (Irganox 1010), and a chloroplatinic acid catalyst solution (H ₂ 1.0 g of PtCl ₆ .6H ₂ O was added to ethanol / 1,2-dimethoxyethane (1/9 v / v) 99
(dissolved in g) was weighed as shown in Table 1 and mixed to prepare a sample.

Injection molding machine (M-32 type) manufactured by Meiki Seisakusho
The mold used was JIS K6301 Dumbbell No. 3 type. The rotation speed of the screw is 50 rpm,
The temperature was controlled at 23-30 ° C. The mold temperature was 120 ° C. and a molded product was obtained by holding for 10 minutes. The dumbbell tensile properties (measurement conformed to JIS K6301) and hardness of the obtained molded product were measured. In addition, regarding the flow characteristics of the sample before curing, a shear rate of 1000 1 /
The viscosity in seconds (sec ^-1 ) was measured. These results are
It is as shown in Table-2. In the comparative example, the viscosity at the time of injection molding was too low to allow extrusion with a screw, and a cured product was separately obtained by a casting method using a mold, and the cured product was measured. .

[0063]

[Table 1]

[0064]

[Table 2] Examination of the above results revealed that the cured product formed from the curable composition of the present invention can provide a gasket having sufficient mechanical properties.

[0065]

INDUSTRIAL APPLICABILITY The present invention can provide a gasket having sufficient mechanical properties.

Claims (5)

[Claims] 1. A polyoxypropylene-based polymer having (A) at least one alkenyl group in the molecule, (B) a compound having at least two hydrosilyl groups in the molecule, (C) a hydrosilylation catalyst, (C) A gasket molded from a curable composition containing D) a fine silica powder and (E) a storage stability improver as a main component. 2. The gasket according to claim 1, wherein the polyoxypropylene polymer having at least one alkenyl group in the molecule has a number average molecular weight of 500 to 50,000. 3. The gasket according to claim 1, wherein the fine silica powder is anhydrous silica. 4. The storage stability improver is dimethyl maleate,
The gasket according to claim 1, which is at least one of dimethyl acetylenedicarboxylate, 2-pentenenitrile, benzothiazole, thiazole, 2,3-dichloropropene, and quinoline. 5. A polyoxypropylene polymer having at least one alkenyl group in the molecule has a number average molecular weight of 6,000 or more and a dispersity (M _w / M _n ) of 1.5 or less. The gasket according to Item 1.