JPH02117911A - Rubber composition - Google Patents

Abstract

PURPOSE:To obtain a novel rubber composition providing rubber having excellent processing properties, improved heat resistance, freeze resistance and weather resistance, by blending an organosiloxane modified acrylic polymer with a reinforcing filler and a specific acetylene alcohol compound. CONSTITUTION:(A) 100 pts.wt. organosiloxane modified acrylic polymer is blended with (B) 10-200 pts.wt. reinforcing filler (e.g., precipitated silica) having >=30m<2>/g specific surface area and (C) 0. 1-10 pts.wt. acetylene alcohol compound shown by formula I or II (R<1> is 1-8C alkyl; m is 0-50; n is 0-25; m+n=0-50) to give the aimed composition. A compound obtained by emulsifying an organosiloxane shown by formula III [R<2> is (substituted) monofunctional group; a is 1.98-2.02; 0.0025-10mol% R<2> is mercapto group-containing monofunctional hydrocarbon], adding a mixture of an acrylic monomer and 0.1-10mol% based on the monomer of an active halogen-containing monomer to the emulsion and radically polymerizing the monomer is preferable as the component A.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to compositions of organosiloxane-modified acrylic polymers, particularly rubbers with excellent processability, heat resistance, cold resistance, oil resistance, and mechanical strength. The present invention relates to an organosiloxane-modified acrylic polymer composition useful for sealing materials, O-rings, gaskets, hoses, wire sheaths, etc.

(Prior Art) Organopolysiloxane has excellent heat resistance, cold resistance, weather resistance, and good electrical properties, so silicone rubber using organopolysiloxane as a base polymer is widely used in industry. However, since this rubber is mainly composed of dimethylpolysiloxane, which dissolves in gasoline, rubber volatile oil, etc., it has the drawbacks of high swelling even after crosslinking and curing with peroxide, etc., and lacks oil resistance. Rubbers with γ, γ, γ-trifluoropropyl groups developed to improve this drawback have not been widely used due to their high cost.

On the other hand, acrylic rubber has excellent heat resistance and oil resistance.
It is particularly attracting attention for use in automobiles.

This improvement is desired because cold resistance and cross-wire processing are poor.

Therefore, attempts are being made to improve these drawbacks by combining silicone rubber and acrylic rubber. It has been proposed to create a silicone-acrylic rubber blend that has good compatibility and kneading workability and can be vulcanized with organic peroxides by blending a copolymer of 7814, JP-A No. 60-152552), the siloxane-acrylic acid ester copolymer used in rice contains aliphatic groups such as vinyl groups bonded to the silicon of the siloxane. Since it is made by copolymerizing a saturated group and an acrylic group, it has the disadvantage of gelling when it becomes a polymer, and it is necessary to add a large amount of this copolymer, but if it is added in a large amount, it may cause problems. Since there is no crosslinking reaction site such as a saturated group, there is no co-vulcanization even when crosslinking and curing with an organic peroxide, and therefore there is a disadvantage that a product with sufficiently high mechanical strength cannot be obtained.

In addition, in the case of these blends, it is desirable to add a small amount of organopolysiloxane to the acrylic rubber to improve the physical properties. ”R test (ASTM 1)
-1329), Gehman Torsion Test (ASTM-D-1
As is clear from the results of No. 053), flexibility cannot be improved unless the overlapping ratio of organopolysiloxane exceeds 50%.

On the other hand, by copolymerizing acrylic polymer and siloxane, the heat resistance, cold resistance, weather resistance of acrylic polymer,
Endurance? #Many proposals have been made regarding techniques for improving the impact resistance (see Japanese Patent Publications No. 351.2 of 1983, Japanese Patent Publication No. 6271 of 1983, and Japanese Patent Publication No. 14086 of 1983). However, since most of them utilize the radical polymerizability of vinyl group-containing siloxanes, they turn into gels when the degree of polymerization is high, making it impossible to obtain sufficient mechanical strength when used as rubber, and as a result, they cannot be used as paints or resins. was only available. Japanese Patent Publication No. 54-6271 describes the copolymerization of a mercapto group-containing siloxane and a vinyl monomer containing an acrylic monomer, but active halogen-containing monomers or epoxy group-containing monomers or =si-CH for the purpose of crosslinking are Copolymerization of =CH, group-containing units was not carried out, and the siloxane also contained R81O, . . . and SiO□ units, so it could not be used as a rubber.

In addition, trithiol-S-triazine compounds (USP, No. 3,622,547, Japanese Patent Publication No. 49-13
215, JP-A-58-222129), sulfur and metal soaps are known. Vulcanization of acrylic rubber with a di- or trithiol-5-t-lyazine compound significantly improves heat resistance, but it has poor storage stability and has not been widely put to practical use.

Furthermore, for the production of rubber compositions, it is known to use polyethylene glycol to improve the dispersion of fillers in the polymer (raw rubber), but this is only mixed and cross-linked. The presence of such polyethylene glycol had an adverse effect on the physical properties of the vulcanized rubber, particularly on the compression set.

(Structure of the Invention) The present invention relates to a novel organosiloxane-modified acrylic polymer composition that solves the above-mentioned disadvantages. 10 to 200 parts by weight of a reinforcing filler that is at least 30 rd/g;
An integer of 0, n is an integer of 0 to 25, but m+n is an integer of 0 to 5
Acetylene alcohol compound represented by (an integer of 0)
It is characterized by comprising 0.1 to 10 parts by weight.

That is, the present inventors have excellent processability, heat resistance,
Cold resistance, weather resistance, oil resistance 1 As a result of extensive research into compositions of organosiloxane-modified acrylic polymers that provide rubber with excellent mechanical properties, we have found that organosiloxane-modified acrylic polymers contain reinforcing fillers and polyoxyethylene groups. We discovered that compositions containing acetylene alcohol compounds are promising, and further investigated the composition and polymerization method of organosiloxane-modified acrylic polymers, reinforcing fillers, and the type and amount of acetylene alcohol compounds having polyoxyethylene groups. The present invention was completed by repeating the steps.

The organosiloxane-modified acrylic polymer, which is component (a) of the composition of the present invention, is a copolymer of organosiloxane and an acrylic monomer, and is vulcanized (crosslinked).
Any polymer can be used as long as it provides a rubber elastic body, but a polymer synthesized by the method described below is preferred because it provides excellent properties. This is done by emulsifying an organosiloxane having a mercapto group-containing monovalent hydrocarbon group represented by the average compositional formula R"S]04:i (in the formula, R2 and a are the same as above), and adding acrylic to this emulsion. system monomer and its 0.1 to 10 mol% active halogen-containing monomer or epoxy group-containing monomer or =S
It is obtained by adding a mixture of i -CH=CH2 group-containing monomer and polymerizing it in the presence of a radical polymerization initiator. This synthesis method will be explained below.

In the above synthesis method, the organosiloxane used as the initiator has an average composition formula RλSt.

This R2 is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a vinyl group,
Alkenyl groups such as allyl groups, aryl groups such as phenyl groups and tolyl groups, cycloalkyl groups such as cyclohexyl groups, or some or all of the hydrogen atoms bonded to the carbon atoms of these groups are replaced by halogen atoms or cyano groups. , an unsubstituted or substituted monovalent hydrocarbon group such as a chloromethyl group, trifluoropropyl group, cyanoethyl group, mercaptomethyl group, mercaptopropyl group substituted with a mercapto group, etc., and a is 1.98 to 2.02. However, if a is less than 1.98, it will not be possible to obtain the elongation necessary for a rubber, and if it exceeds 2.02, the molecular weight of the polymer will become small, making it impossible to obtain the strength necessary for a rubber. . In this organosiloxane, a portion of R2 is required to be a mercapto group-containing -valent hydrocarbon group. If this mercapto group-containing -valent hydrocarbon group is less than 0.0025 mol% of all R2 groups, the crosstalk workability will deteriorate rapidly because the bond between the siloxane and the acrylic polymer will decrease. At the same time, the cold resistance of the acrylic polymer cannot be improved. In addition, if it exceeds 10 mol%, the mercapto group causes cleavage of the siloxane bond, resulting in a decrease in heat resistance, and in addition, the chain length of the acrylic polymer portion becomes short, making it impossible to obtain sufficient mechanical strength. A range of .0025 to 10 mol% is required. Although this organosiloxane is usually linear, it may also include a partially branched or network structure, and the average degree of polymerization is 10.000.
If it is more than that, it will be difficult to knead with the filler, so the degree of polymerization should be 100-10.000. Preferably 4,000
~8,000, but the molecular chain terminals may be capped with an alkoxy group such as a trimethylsilyl group, dimethylvinylsilyl group, mercaptopropyldimethylsilyl group, hydroxyl group, or methoxy group.

This organosiloxane is emulsified prior to copolymerization with the acrylic monomer, and this emulsification may be performed by a known method, and an emulsifier may be added to the polymerized organopolysiloxane and mechanically stirred. For this purpose, a low molecular siloxane may be emulsified and then emulsion polymerized using a sulfonic acid represented by the aliphatic hydrocarbon group of the formula as a polymerization catalyst.

In addition, the content of siloxane in this emulsion is determined from the viewpoint of stability of the emulsion and production efficiency to a solid content of 30~30.
It is preferable that the weight is 50%.

Next, the organosiloxane-modified acrylic polymer is added to the organosiloxane emulsion with an acrylic monomer and an active halogen-containing monomer 1, or an acrylic monomer and an epoxy group-containing monomer, or an acrylic monomer and a 5i-CH═CH2 group-containing monomer. by adding
It is obtained by copolymerizing organosiloxane, an acrylic monomer, and the above monomers added together with the acrylic monomer in the presence of a radical polymerization initiator.The acrylic monomers used here include methyl acrylate, ethyl acrylate, etc. Examples include acrylate, alkyl acrylate such as butyl acrylate, alkoxyalkyl acrylate such as methoxyethyl acrylate, ethoxyethyl acrylate, alkylthioacrylate, cyanoalkyl acrylate, etc.
These must be used in combination with an active halogen-containing monomer, an epoxy group-containing monomer, or a monomer containing 2 groups. This active halogen-containing upper layer includes vinylchloroacetate-1-,
Vinyl-2-chloropropionate, vinyl-3-chloropropionate, allyl chloroacetate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate
Examples include 1-12-chloroethyl vinyl ether 5-chloromethyl-2-norbornene and those containing a bromine atom instead of a chlorine atom, but vinyl chloroacetate is preferred, and the above-mentioned acrylic monomers of this are preferred. The mixing amount with O. If it is less than 1 mol %, the crosslinking density will be low when crosslinked with a vulcanizing agent, and if it exceeds 10 mol %, the crosslinking density will be too high, and in any case, the mechanical strength will be significantly reduced.
It is necessary to set it as the range of 1-10 mol%. In addition, examples of epoxy group-containing monomers include glycidyl acrylate,
Glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether.

Examples include methallyl glycidyl ether, but preferred are glycidyl methacrylate and allyl glycidyl ether, and the amount of these mixed with the acrylic monomer described in "2" is 0.000 for the same reason as in the case of active halogen-containing tops. Is it necessary to set it in the range of 1 to 10 mol%? Further, as the =81-CH=CH2 group-containing monomer, a monomer represented by the following formula is preferable.

CI-(.

/ Also, the amount of this mixture with the above-mentioned acrylic monomer needs to be in the range of 0.1 to 10 mol % for the same reason as the active halogen-containing monomer and the epoxy group-containing monomer.

The amount of acrylic monomer added is such that the amount of acrylic groups in the target siloxane-modified acrylic polymer is 1.
If it is less than 0% by weight, a polymer with the desired oil resistance and mechanical strength cannot be obtained, and if it exceeds 99% by weight, the resulting polymer will not have sufficient heat resistance or cold resistance. 10 for 90-1% by weight of siloxane
The amount of acrylic is preferably 50 to 99% by weight, and more preferably 50 to 99% by weight.

A portion of the above acrylic monomers may be acrylonitrile, styrene, α-methylstyrene, acrylamide,
It is also possible to substitute and copolymerize with other polymerizable monomers such as vinyl chloride, vinylidene chloride, and vinyl acetate.

The rubber composition of the present invention comprises a siloxane-modified acrylic polymer obtained by adding and copolymerizing the above-mentioned acrylic monomer and a monomer having a crosslinking group used together with the acrylic monomer to the organosiloxane emulsion. Although it can be used as a raw material, the radical polymerization initiators used for copolymerization include ammonium persulfate, potassium persulfate, hydrogen peroxide, and t.
-Water-soluble types such as butyl hydroperoxide,
Or benzoyl peroxide, lauryl peroxide, cumene hydroperoxide, cumyl peroxy neodecanoate, dibutyl peroxide, t
Examples include oil-soluble types such as -hexyl peroxypivalate, diisopropyl peroxydicarbonate, di-butyl peroxymaleic acid, and azobisisobutyronitrile. When copolymerizing at a low temperature of 40°C or lower, it is preferable to use a redox catalyst in combination with a reducing agent, which combines the above radical generating source with acidic sodium sulfite, ascorbic acid, sodium formaldehyde sulfoxylate, glucose, and sucrose. A combination of a reducing agent such as and a trace amount of ferrous salt is preferred. Note that soluble copper salts, cobalt salts, and manganese salts can also be used instead of ferrous salts.

The polymerization temperature is usually in the range of 0 to 80°C, but the lower the polymerization temperature, the better the crosstalk workability and the improved performance after vulcanization, so it is preferably 40°C or lower. Polymerization may also be carried out at 0°C or lower by adding glycol. After the polymerization is complete, a salt such as calcium chloride is added to the reaction system to cause coagulation, and this coagulation is then decanted.
The desired siloxane-modified acrylic polymer can be obtained by separating it from the aqueous phase through J filtration, washing and drying.

Next, the reinforcing filler, which is a component of the rubber composition of the present invention, is required to be fine particles with a specific surface area of at least 30 m2/g. Either of these is fine. Examples of these include fume silica produced by a dry process, represented by the component names Aerosil and Cabosil, precipitated silica synthesized by a wet process from alkyl silicate and sodium silicate, magnesium silicate, calcium silicate, and carbon black. However, the surface of these may be treated with silane or siloxane. If the amount of this reinforcing filler is less than 10 parts by weight based on 100 parts by weight of the polymer of component (a), the reinforcing effect will be insufficient and practical mechanical strength will not be obtained; If it exceeds the amount, good moldability cannot be obtained and the mechanical strength will also decrease, so it is necessary to keep the amount in the range of 10 to 200 parts by weight, but this preferable range is 30 to 80 parts by weight. In addition, when adding this reinforcing filler, vinyltrialkoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane,
-So-called carbon functional silanes such as mercaptopropyltrimethoxysilane, or α, ω-
When various organosilicon compounds that have an affinity for silica, such as dihydroxymethylvinylpolysiloxane and hexamethyldisilazane, are added, these are adsorbed and bonded to the filler surface, increasing the affinity between the filler and the polymer. ,
The filler is better dispersed. Note that when α,ω-dihydroxydimethylpolysiloxane or hexamethyldisilazane is used as the organosilicon compound, it makes the surface of the filler hydrophobic, which has the effect of preventing foaming or deterioration of electrical properties due to moisture adsorption. Also give.

Next, the acetylene alcohol compound which is component c) of the rubber composition of the present invention is represented by the general formula, where R1 is an alkyl group having 1 to 8 carbon atoms. Examples include ethyl group, propyl group, butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, 2-ethylhexyl group, etc., and the following are exemplified as acetylene alcohol compounds shown in the above-mentioned narrowing. Ru.

CH.

112UN3 Here, n is an integer from 0 to 25 1m is an integer from 0 to 50, m
+n represents an integer from 0 to 50.

All of the above acetylene alcohol compounds are commercially available (
11 (trade name: Surfynol, manufactured by Shinkagaku Co., Ltd.).

The present inventors have discovered that this acetylene alcohol compound improves the dispersibility and processability of fillers in organosiloxane-modified acrylic rubber compositions, and also improves various physical properties of vulcanized rubber, and that it has no side effects on any of the properties. It was found that the amount of the filler in component (a) is less than 0.1 parts by weight per 100 parts of the organosiloxane-modified acrylic polymer of component (a). It cannot be dispersed, resulting in a composition with high Mooney viscosity and poor roll processability, and even if it exceeds 10 parts by weight, no improvement in processability is seen, so 0.
The amount added is 1 to 10 parts by weight.

In order to obtain the rubber composition of the present invention, it is necessary to uniformly mix predetermined amounts of the components (a) to (c). -, a Banbury mixer, an intermixer, or a screw type continuous kneader. In addition to ingredients a) to c), antioxidants, oils for processing aids, ultraviolet absorbers, colorants, quartz powder and clay as fillers, flame retardants, etc. may be added to normal rubber formulations as necessary. Various additives may also be added.

By adding a crosslinking agent to the obtained composition and molding it by a known method such as molding, extrusion molding, or calendar molding, desired sealing materials, O-rings, gaskets, hoses, etc. can be obtained.

As a crosslinking agent, a) when the crosslinking site of the component polymer is an active halogen, for example, di- or trithiol-s-
There are triazine compounds, and examples of such triazine compounds include the following. In this system, dithiocarbamic acid derivatives, 2,2'-dithiobisbenzothiazole, alkali metal salts or alkaline earth metal salts of organic carboxylic acids, etc. may be used in combination. It may also be an alkali metal salt or sulfur donor of an organic carboxylic acid. In order to obtain even better vulcanizability and processing stability, N-substituted mono or bismaleimides, ureas, thioureas, imidacillins, amino acids, etc. may be used in combination, when the crosslinking site is an epoxy group. , dithiocarbamate, organic carboxylic acid ammonium salt, diamine carbamate, polyamine, phthalic anhydride and imidazole compound, polyvalent carboxylic acid compound or polyvalent carboxylic acid anhydride and quaternary ammonium salt or quaternary phosphonium salt, guanidine compound Examples include sulfur-based compounds and sulfur-based compounds. In addition, when the vulcanization site is =Si-CI (=CH2 group), examples of the crosslinking agent include organic peroxides, such as dicumyl peroxide, butyl cumyl peroxide (t-butylperoxy)hexane, etc. Illustrated.

If the amount of the cross-linking agent added is less than 0.1 part by weight per 100 parts by weight of the siloxane-modified acrylic polymer, which is the component (a), it will not be possible to form a practically usable elastic body, and if it is more than 10 parts by weight, the 0.1 to 1 because mechanical strength decreases.
It is desirable that the content be 0 parts by weight.

The rubber composition of the present invention has low Mooney viscosity and excellent processability such as roll workability. In addition, the physical properties of vulcanized rubber are excellent, such as high elongation, and while polyethylene glycol, the known dispersant mentioned above, deteriorates physical properties, especially compression set, as a side effect.
This is not the case with the acetylene alcohol compound of component (iii) in the present invention. Therefore, the composition of the present invention can be used for sealing materials, O-rings, gaskets, hoses,
It is said to be useful for applications such as electric wire sheaths.

(Example) Next, an example of the present invention will be given. All parts below indicate parts by weight.

Preparation of Siloxane Emulsion 1,500 parts of octamethylcyclotetrasiloxane, 40 parts of mercaptopropylmethylsiloxane.

8 parts and 1,500 parts of pure water were mixed, and to this was added 15 parts of sodium lauryl sulfate and 1 part of dodecylbenzenesulfonic acid.
After adding 0 parts, emulsifying by stirring with a homomixer, a stable emulsion was made by passing it twice through a homogenizer with a pressure of 3 OOOpsi.Next, this was placed in a flask and heated at 70°C for 12 hours. After cooling to room temperature and standing for 24 hours, the pH was adjusted to 7 using sodium carbonate, nitrogen was blown for 4 hours, and volatile siloxane was distilled off by steam distillation, and then pure water was added. When the nonvolatile content was adjusted to 33%, a methylpolysiloxane emulsion containing 1.5 mol% of mercapto groups was obtained.

A reactor equipped with a copolymerization stirrer, a condenser, a thermometer, and a nitrogen gas inlet was charged with 758 parts of the emulsion prepared above (siloxane content: 250 parts) and 1,200 parts of pure water, and the mixture was heated inside the reactor under a nitrogen gas flow. After adjusting the temperature to 10℃,
Here, 0.40 part of t-butyl hydroperoxide,
Q-ascorbic acid 2.0 parts, ferrous sulfate heptahydrate 0
．． 0 0 1 part was added, and then 364.5 parts of ethyl acrylate and 10 parts of the vinyl chloroacetate described above were added.
.

5 parts of the mixture was added dropwise over 3 hours, and after the addition was completed, stirring was continued for another 1 hour to complete the reaction. A saturated calcium chloride aqueous solution was added to the polymerization system, filtered, washed with water, and dried to obtain a siloxane-modified product. Acrylic polymer (hereinafter referred to as P)
-1) was obtained. The Mooney viscosity [ML1□ (100°C)] of this polymer was 40.

Furthermore, the siloxane emulsion made above was added to 379
part (9125 parts of siloxane), acrylic resin
A siloxane-modified acrylic polymer (hereinafter abbreviated as P-2) was obtained by copolymerization and post-treatment in the same manner as above except that 342.5 parts of butyl acrylate and 147 parts of methoxyethyl acrylate were used. The Mooney viscosity of this polymer was 41. The polymerization yields of the above two copolymerizations were in the range of 98 to 99%.

Examples 1 to 3, Comparative Example 1 100 parts of siloxane-modified acrylic polymer P-1 was wound around a roll, and the specific surface area was 200rr? 50 parts of Aerosil 200 (1-, 1 bottle, trade name manufactured by Aerosil), 2 parts of Naragat 445 (trade name, manufactured by Uniroyal), 11 parts of Ste 79, 1 part of Surfinol 440 (II Trust) as an acetylene alcohol compound. Add 0.1.2 or 5 parts of the product name manufactured by Kagaku Co., Ltd., in the general formula (1), where 1 is an isobutyl group and m0n is 3.5 on average), and heat treated at a roll temperature of 130°C for 10 minutes.・Kneading was performed.

Next, in order to examine the processability of the compositions obtained above, Mooney viscosity was measured (LOO'C), and 1.5 parts of trithiocyanuric acid, 5 parts of magnesium oxide, and zinc dimethyldithiocarbamate were added to these compositions. 1.5 parts were mixed uniformly, and 1
A rubber sheet with a thickness of 2 m was obtained by press molding for 2 minutes, and the mechanical strength of this sheet was measured according to the measuring method of JIS K6301.

The above formulations are summarized in Table 1, and the Wl determination results are also listed in Table 1. As shown by these results, the composition of the present invention had a low Mooney viscosity and good roll processability, and the rubber obtained by molding had low hardness and high elongation.

Examples 4-6. Comparative Example 2 A composition was prepared in the same manner as in Examples 1 to 3 with the formulation shown in Table 2, and the composition was press-molded to evaluate its properties. The results were as listed in Table 2.

Table 1 Table 2 ■0 Product name manufactured by Shinkagaku Co., Ltd., R1 in the general formula (1) above
is an isobutyl group, m + n = 10 Examples 7 to 10,
Comparative Example 3 Next, an example showing the influence of the reinforcing filler will be described. Specific surface area is 23 with respect to 100 parts of polymer P-2 used in Example 4.
0 dlg precipitated silica carnibutyl LP [Nippon Silica ■
30 parts, 40 parts, 50 parts as shown in Table 3.
After adding 1 part of stearic acid, 2 parts of Naragard 445 (listed above), 2 parts of Surfynol 440 (listed above), and siloxane oil (viscosity 20 cS (25°C))
) of α,ω-dihydroxypolydimethylsiloxane) 5
and a pressure kneader. Furthermore, after adding 1.5 parts of trithiocyanuric acid, 5 parts of magnesium oxide, and 1.5 parts of zinc dimethyldithiocarbamate to this system,
l Press vulcanization at 165°C for 12 minutes under pressure of OOkgf#j, and then secondary vulcanization at 175°C for 8 hours to obtain a thickness of 2II.
An I+ sheet was obtained.

The physical properties of this sheet were measured according to JIS K 6301, and the results are also listed in Table 3. In addition, as a comparative example, the characteristics when 4.0 parts of Crystallite VXS [■ trade name manufactured by Ryumori Co., Ltd.] having a specific surface area of 19 parts 1 g are added instead of Nibsil LP are also shown.

Table 3 Example 11, Comparative Example 4 Next, an example showing the superiority of acetylene alcohol over polyethylene glycol will be given. For 100 parts of polymer P-2 used in Example 4, 5 parts of Nibcil LP (mentioned above)
After adding 0 parts, 1 part of stearic acid, Naragard 445 (
2 parts of Surfynol 440 (mentioned above) and 10 parts of Surfynol 440 (mentioned above).
Mixing was performed using this roll. As a comparative example, Nirasan polyethylene glycol # was used instead of Surfynol 440.
A composition was prepared in the same manner except that 4000 was used. 1.5 parts of trithiocyanuric acid, 5 parts of magnesium oxide, and 1.5 parts of zinc dimethyldithiocarbamate were added to this system, and then under a pressure of 70 kgf/ffl. 165℃X1
Press vulcanization was performed for 2 minutes, and secondary vulcanization was performed at 175° C. for 8 hours to obtain a molded product.

The above formulations are summarized in Table 4. Also molding (vulcanization)
The results of measuring the rebound elasticity and compression set of rubber are shown in the fourth section.
Also listed in the table.

Table 4 Patent Applicant Shin-Etsu Chemical Co., Ltd. Procedural Amendment Band Drawing January 31, 1989 Director General of the Patent Office Yoshi 1) Moon Takeshi 1, Indication of the case 1988 Patent Application No. 271467 2, Name of the invention Rubber Composition 3, Relationship with the person making the amendment Patent applicant 4, Attorney 5, Date of amendment order 7 Contents of the amendment 1) Amended "acrylic polymer" on page 5, line 10 of the specification to "acrylic monomer" do.

2) Page 21, line 3 of the specification, page 27, line 11, and line 3 of the specification
In the bottom two lines of page 0, correct "Product name manufactured by 8-Yo Kagaku Co., Ltd." to "R Product name manufactured by Ni-Syo Kagaku Co., Ltd." respectively.

that's all

Claims (1)

[Claims] 1. A) Organosiloxane-modified acrylic polymer: 1
00 parts by weight b) Reinforcing filler with a specific surface area of at least 30 m^2/g: 10 to 200 parts by weight and c) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... (I) or ▲
There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (In the formula, R^1 is an alkyl group with 1 to 8 carbon atoms, m is 0 to
An integer of 50, n is an integer of 0 to 25, but m+n is an integer of 0 to 25.
Acetylene alcohol compound represented by (an integer of 50):
A rubber composition comprising 0.1 to 10 parts by weight. 2. The organosiloxane-modified acrylic polymer has an average compositional formula R^2_8SiO_(_4_-_a_)_/_2 (wherein R^2 is an unsubstituted or substituted monovalent hydrocarbon group, and a is 1.
98-2.02, 0.0025-10 of R^2
An organosiloxane represented by mol% is a monovalent hydrocarbon group containing a mercapto group is emulsified, and in this emulsion, an acrylic monomer and 0.1 to 10 mol% of an active halogen-containing monomer or an epoxy group-containing monomer or ≡S
2. The rubber composition according to claim 1, which is obtained by adding a mixture with a monomer containing i-CH=CH_2 groups and polymerizing the mixture in the presence of a radical polymerization initiator.