JPH0616872A - Rubber composition - Google Patents

Abstract

PURPOSE:To improve the dispersibilities of a silicone rubber and a hydrogenated nitrile rubber in each other in a rubber compsn. based on the two rubbers and obtain from the compsn. a cross-linked rubber having improved mechanical properties and resistances to heat, cold, and oil. CONSTITUTION:A rubber compsn. basically comprises 100 pts.wt. polymer component comprising 98-2% hydrogenated nitrile rubber having a Mooney viscosity of 70 or lower and 2-98% organopolysiloxane, 200 pts.wt. filler, and 0.3-10 pts.wt. peroxide cross-linker, and is prepd. by mixing first a mixture comprising the nitrile rubber and the filler, a mixture comprising the organopolysiloxane and the filler, and, if necessary, an additional filler, and then mixing with the cross- linker.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention comprises (A) (a) a hydrogenated nitrile rubber having a Mooney viscosity of 70 or less, (b) an organopolysiloxane, (B) a filler, and (C) a peroxide crosslinking agent. The present invention relates to a basic rubber composition, a method for producing the rubber composition, and a crosslinked product of the rubber composition.

The rubber composition of the present invention has good roll processability, and the crosslinked rubber product obtained from this rubber composition has excellent tensile strength, heat resistance, cold resistance and oil resistance, and has a wide range of industrial and chemical fields. It is useful in the field.

[0003]

2. Description of the Related Art Silicone rubber is known to have excellent properties such as releasability, heat aging resistance, cold resistance and weather resistance, but is inferior in properties such as tensile strength, oil resistance and water resistance. There is. For this reason, the silicone rubber has been limitedly used for applications requiring mechanical strength and applications where it is used in contact with oil or water. Hydrogenated nitrile rubber has excellent properties such as tensile strength, oil resistance, and heat resistance,
It does not have the ability to withstand use under severe conditions such as heat aging resistance, cold resistance, and weather resistance. As described above, the silicone rubber and the hydrogenated nitrile rubber have characteristics that should complement each other's performance, and it is expected that an excellent rubber composition can be provided by mixing them.

As a known technique for mixing silicone rubber and hydrogenated nitrile rubber, German Patent 3812354 discloses mechanical mixing of silicone rubber and hydrogenated nitrile rubber. The mechanical mixing disclosed herein is a simple mechanical mixing that is typically used for rubber combinations with good affinity. Silicone rubber and hydrogenated nitrile rubber have a poor affinity, and hydrogenated nitrile rubber has a remarkably higher viscosity than silicone rubber. Therefore, even if both are mechanically kneaded, a uniform rubber composition cannot be obtained. difficult. In addition, it is difficult to obtain a uniform crosslinked product because the induction time of the crosslinking reaction and the crosslinking reaction rate of the silicone rubber and the hydrogenated nitrile rubber are different. Therefore, the cross-linked product of the composition obtained by blending the silicone rubber and the hydrogenated nitrile rubber has only insufficient physical properties of vulcanization,
The characteristics of both rubbers have not yet been brought out.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a rubber composition based on a silicone rubber and a hydrogenated nitrile rubber, which improves the poor mechanical mixing property due to the difference in viscosity between the silicone rubber and the hydrogenated nitrile rubber. Thus, while significantly improving the dispersibility of both, to improve the roll processability of the uncrosslinked rubber composition, improve the tensile strength and other mechanical properties of the crosslinked product, further, heat aging resistance, cold resistance, oil resistance To improve the sex.

[0006]

The above object can be achieved by the rubber composition of the present invention which essentially comprises the following three components (A), (B) and (C). (A) (a) Hydrogenated nitrile rubber 98 having a Mooney viscosity of 70 or less and preferably an iodine value of 120 or less
˜2% by weight, and (b) organopolysiloxane 2 to 98
100 parts by weight of a polymer component consisting of 10% by weight, (B) 200 parts by weight or less of a filler, and (C) 0.3 to 10 parts by weight of a peroxide crosslinking agent.

The rubber compound of the present invention comprising the above three components is manufactured by the following method. That is, (a ') 98 to 2 parts by weight of hydrogenated nitrile rubber having a Mooney viscosity of 70 or less, and 0 to 5 parts with respect to 100 parts by weight of the hydrogenated nitrile rubber.
Hydrogenated nitrile rubber compounded with 0 part by weight of filler, (b ') 2 to 98 parts by weight of organopolysiloxane, and 20 to 70 parts by weight per 100 parts by weight of the organopolysiloxane. An organopolysiloxane blended with an agent (however, the total amount of the hydrogenated nitrile rubber in the component (a ') and the organopolysiloxane in the component (b') is 100 parts by weight), and If desired, (B ′) additional filler (provided that the total amount of filler used is not more than 200 parts by weight) is mixed, and then (C)
It is a production method comprising mixing 0.3 to 10 parts by weight of a peroxide crosslinking agent. The present invention further provides (A),
Provided is a rubber cross-linked product obtained by peroxide-crosslinking a rubber composition comprising three components (B) and (C).

The hydrogenated nitrile rubber having a Mooney viscosity of 70 or less used in the present invention is a partially or completely hydrogenated nitrile rubber having a Mooney viscosity of 70 or less at 100 ° C. When a hydrogenated nitrile rubber having a Mooney viscosity of more than 70 is used, the difference in viscosity between the hydrogenated nitrile rubber compound and the organopolysiloxane compound becomes too large and the dispersibility deteriorates. The preferred Mooney viscosity of the hydrogenated nitrile rubber is 45 or less.

The hydrogenated nitrile rubber used in the present invention can be produced by partially or completely hydrogenating the nitrile rubber by a known method. The degree of hydrogenation of the hydrogenated nitrile rubber can be indicated by an iodine value, but in the present invention, a hydrogenated nitrile rubber having an iodine value of 120 or less is usually used. Preferably, the iodine value is 60
It is the following.

The hydrogenated nitrile rubber is obtained by hydrogenating an unsaturated nitrile-conjugated diene polymer rubber and by hydrogenating an α, β-unsaturated nitrile-conjugated diene-ethylenically unsaturated monomer multipolymer rubber. Is included.

Examples of the α, β-unsaturated nitrile include acrylonitrile and methacrylonitrile, and examples of the conjugated diene include 1,3-butadiene, 2,3-dimethylbutadiene, isoprene and 1,3-pentadiene. As the ethylenically unsaturated monomer, styrene, p
Vinyl aromatic compounds such as -t-butylstyrene and chloromethylstyrene, unsaturated monocarboxylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate , An alkoxyalkyl ester of the above unsaturated monocarboxylic acid such as ethoxyethyl (meth) acrylate, a dialkyl ester of an unsaturated dicarboxylic acid such as dimethyl itaconic acid, dimethyl maleate, dimethyl fumarate, acrylic acid, methacrylic acid, maleic acid Unsaturated monocarboxylic acids such as acid and itaconic acid monoesters, and unsaturated dicarboxylic acids and their monoesters, (meth) acrylamides,
N-substituted (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methoxyethyl (meth) acrylamide are included.

The organopolysiloxane used in the present invention is composed of repeating siloxanes having a substituted hydrocarbon group and has an average compositional formula R _a SiO _{(4-a) / 2} (wherein R is a substituted or unsubstituted). It represents a hydrocarbon group.
Is 1 ≦ a ≦ 3. ). Examples of R in the formula include alkyl groups such as methyl group, ethyl group, propyl group and butyl group, aryl groups such as phenyl group and tolyl group, alkenyl groups such as vinyl group and allyl group, and hydrocarbon groups thereof. And a group in which at least one hydrogen atom of the alkyl group is substituted with a mercapto group, and the like.

The organopolysiloxane used in the present invention preferably contains carbon-carbon unsaturated bonds in an amount of 100 ppm or more based on the weight of the organopolysiloxane.
When the content of the carbon-carbon unsaturated bond is 100 ppm or more based on the weight of the organopolysiloxane, the rubber composition of the present invention has improved tensile strength after crosslinking. It is more preferable to use an organopolysiloxane having a carbon-carbon unsaturated bond of 200 ppm or more based on the weight of the organopolysiloxane.

Conventionally, as a hydrogenated nitrile rubber, a gum having a high Mooney viscosity of more than 70 has been generally used. On the other hand, organopolysiloxane has such a viscosity that the Mooney viscosity cannot be measured unless a filler is added. They are low gums, both of which in mechanical mixing as gums,
The composition has a remarkably poor dispersion state. Therefore, in the method for producing the rubber composition of the present invention, as described above, the hydrogenated nitrile rubber having a Mooney viscosity of 70 or less is used, and the organopolysiloxane is mixed with a filler.
By blending 0 to 70 parts by weight (based on 100 parts by weight of organopolysiloxane), the dispersion state of the rubber composition is improved. Preferably, the hydrogenated nitrile rubber also contains 50 parts by weight or less of a filler per 100 parts by weight of the rubber. If more than 70 parts by weight of the filler is added to the organopolysiloxane, or if more than 50 parts by weight of the hydrogenated nitrile rubber is added, the viscosity of each compound will be too high and the dispersion will be worse. ,
The mechanical properties of the rubber cross-linked product after mixing deteriorate. A more preferable blending ratio of the filler is 4 with respect to the hydrogenated nitrile rubber.
0 parts by weight or less, 30 to 5 relative to organopolysiloxane
0 parts by weight. Further, a filler can be further compounded within a range in which the total amount is 200 parts by weight or less with respect to the total 100 parts by weight of the hydrogenated nitrile rubber and the organopolysiloxane.

In the present invention, as the filler to be added to the organopolysiloxane and optionally the hydrogenated nitrile rubber, silica and carbon black which are reinforcing fillers are preferable. The silica may be either dry silica or wet silica, but the specific surface area thereof is preferably 50 m ² / g or more, more preferably 100 to 400 m ^2.
/ G. These silicas may be used as they are, or may be surface-treated with an organosilicon compound such as organochlorosilane, organoalkoxysilane, organopolysiloxane, and hexaorganodisilazane.

Other fillers include fine quartz powder, diatomaceous earth, zinc white, basic magnesium carbonate, activated calcium carbonate, magnesium silicate, aluminum silicate, titanium dioxide, talc, mica powder, aluminum sulfate, calcium sulfate. Inorganic fillers such as barium sulphate, asbestos, glass fibers, and polyester fibers,
Examples thereof include organic reinforcing agents or organic fillers such as polyamide fiber, vinylon fiber and aramid fiber.

The hydrogenated nitrile rubber (a) and the organopolysiloxane (b) are based on the total amount of both, the former being 98 to 2% by weight, preferably 80 to 20% by weight, and the latter being 2 to 98% by weight. , Preferably 20 to 80% by weight. Greater than 98% by weight of hydrogenated nitrile rubber compound and less than 2% by weight of organopolysiloxane compound, or less than 2% by weight of hydrogenated nitrile rubber compound and 98% of organopolysiloxane compound. When the content is more than 10% by weight, hydrogenated nitrile rubber and organopolysiloxane cannot complement each other's performance, and provide a rubber composition with excellent tensile strength, heat aging resistance, cold resistance, oil resistance, etc. Can not do it.

The rubber composition of the present invention further comprises 0.3 parts by weight of 100 parts by weight of the polymer component (A) comprising the hydrogenated nitrile rubber (a) and the organopolysiloxane (b).
-10 parts by weight, preferably 0.8-5 parts by weight of peroxide crosslinking agent. If the amount of the peroxide cross-linking agent is less than 0.3 parts by weight, the cross-linking will be insufficient and the tensile strength will be poor.
If it exceeds 0 part by weight, it will be over-crosslinked, and it will be a crosslinked product of a rubber compound having poor elongation and the like, which is outside the object of the present invention.

Specific examples of the peroxide crosslinking agent used in the present invention include 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5-.
Di (t-butylperoxy) hexane, 2,2-bis (t-butylperoxy) -p-diisopropylbenzene, dicumyl peroxide, di-t-butylperoxide, t-butylperbenzoate, 1,1 -Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dicumyl peroxide,
Dialkyl peroxide and ketal peroxide can be mentioned.

The method for preparing the rubber composition of the present invention is not particularly limited. A general preparation method performed by mixing rubber can be adopted. Usually, 100 parts by weight of hydrogenated nitrile rubber and 0 to 50 parts by weight of the filler are kneaded in advance, and 100 parts by weight of organopolysiloxane and 20 to 70 parts by weight of the filler are kneaded in advance, respectively, and the mixture is mixed at a predetermined ratio. Kneading is carried out, and then a peroxide cross-linking agent is mixed with a roll or the like to obtain a rubber compound.

Mixing of the compound of hydrogenated nitrile rubber and the compound of organopolysiloxane is usually preferably carried out at a viscosity ratio of these compounds in the range of 0.2 to 5. The viscosity ratio of the formulation used here is the ratio of shear viscosity at the temperature of actual mixing. If the viscosity ratio of the compound is less than 0.2 or exceeds 5, the dispersed state becomes poor and the mechanical properties of the crosslinked product after mixing deteriorate. The viscosity ratio of this compound is such that the Mooney viscosity of the above-mentioned hydrogenated nitrile rubber is lowered to 70 or less, and 20 to 70 parts of the filler is added to the organopolysiloxane, and preferably the hydrogenated nitrile rubber is further added. It is adjusted by blending 50 parts or less of the filler. The viscosity ratio of the preferred formulation is
It is in the range of 0.4 to 2.5.

The rubber composition of the present invention is prepared by using an open-type kneader such as a mixing roll, a closed-type kneader such as a Plavender mixer or a Banbury mixer, a single-screw extruder, a twin-screw extruder, a Farrell mixer or a busco. It can be carried out with a continuous kneader such as a kneader. Preparation temperature is room temperature to 30
The range of 0 ° C is preferred. The mixing of the peroxide cross-linking agent with the rubber compound is preferably carried out in the range of room temperature to 120 ° C. in order to suppress the decomposition of the peroxide cross-linking agent.

The rubber composition of the present invention basically comprises the above-mentioned three components (A) to (C), but in addition to this, known compounding agents usually used for rubber can be added. That is, processing aids such as metal oxides, amines, fatty acids and their derivatives; plasticizers such as polydimethylsiloxane oil, diphenylsilanediol, trimethylsilanol, phthalic acid derivatives, adipic acid derivatives, trimellitic acid. Derivatives: Softeners such as lubricating oils, process oils, coal tar, castor oil, calcium stearate; Anti-aging agents such as phenylenediamines, phosphates, quinolines, cresols, phenols, dithiocarbamate metals Examples of salts and heat-resistant agents include iron oxide, cesium oxide, potassium hydroxide, iron naphthenate, potassium naphthenate; other lubricants, tackifiers, scorch inhibitors, cross-linking accelerators, cross-linking aids, accelerating aids, cross-linking agents. Retarders, colorants, UV absorbers, flame retardants Oil resistance improvers, such as foaming agents. These compounding agents may be added in the process of producing the rubber composition of the present invention, if necessary.

The rubber composition of the present invention is crosslinked with a peroxide crosslinking agent. As the crosslinking conditions, usual peroxide crosslinking conditions for rubber can be applied. The crosslinking is usually performed at a temperature of 100 to 250 ° C., a pressure of 0 to 300 kg / cm ² , and a crosslinking time of 5 seconds to 10 hours (including post-crosslinking). Such high temperature cross-linking conditions can be obtained by applying energy such as heat, electron beams, ultraviolet rays and electromagnetic waves. Crosslinking method of the rubber composition of the present invention, press molding is usually performed by vulcanization of rubber, transfer molding, injection molding, batch vulcanization such as vulcanization, hot chamber, pressure tube, rotocure, salt bath, flow. It can be carried out by continuous vulcanization such as flooring or high frequency heating.

[0025]

In the production of the rubber composition of the present invention,
Since the viscosity of the hydrogenated nitrile rubber is controlled to be low, the filler is added to the organopolysiloxane, and the filler is added to the hydrogenated nitrile rubber as necessary, the hydrogenated nitrile rubber and the organopolysiloxane are also added. Highly uniform dispersibility with That is, unlike the known mixture of simple hydrogenated nitrile rubber and silicone rubber, the mechanical mixing property between both rubber components is improved, and as a result, the dispersibility is remarkably improved. In addition, the composition of the present invention can be quickly wound around a roll, and the workability of roll processing is significantly improved, as compared with the case where a simple mixture takes a long time to wind around a roll.

The crosslinked rubber composition of the present invention is excellent in mechanical strength such as tensile strength and exhibits excellent heat aging resistance, cold resistance and oil resistance. The rubber composition of the present invention having such excellent properties can be used in a wide range of mining and industrial fields and chemical fields. In particular, solvents, oils,
Automotive hydraulic hoses used in contact with water, air, etc.
Hoses such as air hoses for automobiles, radiator hoses for automobiles, hydraulic hoses for various machines such as construction machinery and machine tools; seals such as O-rings, packings, gaskets, oil seals; boots such as constant velocity joint boots It is useful for applications such as diaphragms, cables, caps, rolls, belts, and the like.

[0027]

EXAMPLES The present invention will be described in more detail with reference to examples. Parts and% in Examples and Comparative Examples are based on weight unless otherwise specified. The (partially) hydrogenated nitrile rubber used to exemplify the invention is as described below. HNBR-1 (L-ML): A hydrogenated nitrile rubber having a Mooney viscosity of 45 at 100 ° C., an iodine value of 26, and a bound acrylonitrile content of 36%.

HNBR-2 (H-ML): A hydrogenated nitrile rubber having a Mooney viscosity of 78 at 100 ° C., an iodine value of 27 and a bound acrylonitrile content of 36%. Product of Zeon Corporation, Z-pole 2020 (ZET
POL2020). HNBR Blend-1 (20): Hydrogenated nitrile rubber having a Mooney viscosity of 25 at 100 ° C., an iodine value of 28, and a bound acrylonitrile content of 36%, and Aerosil # 200 (AEROO) manufactured by Degussa.
20 parts of SIL) mixed with a 6 inch roll.

HNBR Formulation-2 (40): Using the same HNBR used in HNBR Formulation-1 (20),
This HNBR was mixed with 40 parts of Aerosil # 200 on a 6-inch roll. HNBR Blend-3 (60): HNBR-2 (HM
A mixture of L) mixed with 60 parts of Aerosil # 200 on a 6 inch roll. HNBR Blend-4 (20): Hydrogenated nitrile rubber having a Mooney viscosity of 35 at 100 ° C., an iodine value of 60, and a bound acrylonitrile content of 36%, and Aerosil # 200 (AERORO) manufactured by DEGUSSA.
20 parts of SIL) mixed with a 6 inch roll.

HNBR Blend-5 (20): Hydrogenated nitrile rubber having a Mooney viscosity of 38 at 100 ° C., an iodine value of 5, and a bound acrylonitrile content of 36%, and Aerosil # 200 manufactured by DEGUSSA.
20 parts of (AEROSIL) mixed with a 6 inch roll. HNBR Formulation-6 (CB 20): HNBR Formulation-
Using the same HNBR used for 1 (20),
A blend of 20 parts of HAF carbon black mixed with NBR on a 6 inch roll.

The NBR used to exemplify the invention is as described below. NBR Blend-1 (20): NB with a bound acrylonitrile content of 36% and a Mooney viscosity of 36 at 100 ° C.
A mixture of R and 20 parts of Aerosil # 200 on a 6-inch roll.

The organopolysiloxanes used to exemplify the invention are as described below. Silicone rubber compound-1 (20): A compound prepared by mixing 20 parts of Aerosil # 200 with a 1.8 L Banbury mixer in a polydimethylsiloxane rubber having a carbon-carbon unsaturated bond content of 470 ppm.

Silicone rubber formulation-2 (50): 50 parts of Aerosil # 200 to the polydimethylsiloxane rubber used in silicone rubber formulation-1 (20), 1.8.
Blended with L Banbury mixer. Silicone rubber compound-3 (50): A compound prepared by mixing 50 parts of Aerosil # 200 with a 1.8 L Banbury mixer in a polydimethylsiloxane rubber having a carbon-carbon unsaturated bond content of 800 ppm.

The peroxides and antioxidants used to exemplify the present invention are as described below. Peroxide-1: Perbutyl P (P manufactured by NOF CORPORATION)
erbutyl P) peroxide-2: Perhexa 2.5B manufactured by NOF CORPORATION
(Perhexa 2.5B) Anti-aging agent-1: Irganox 10 manufactured by Shiva Geigy
10. (Iruganox 1010)

The composition of the present invention was subjected to press vulcanization at 170 ° C. for 25 minutes and then subjected to physical property evaluation according to JIS K6301. After vulcanizing the composition of the present invention, the dispersed state was observed with a transmission electron microscope, and the dispersed particle size was determined by image analysis. The shear viscosity ratio of the composition of the present invention was measured by measuring the HNBR compound and the silicone rubber compound respectively with an MPT device (Melt Pr) manufactured by Monsanto.
Accessibility Tester)
Capillary of 1.5mmφ, 150 ℃, shear rate 8
The shear viscosity was determined under the condition of ⁰ sec ^{−1, and} the shear viscosity ratio was determined from the ratio of both viscosities.

Examples 1 to 3 HNBR-1 (L-ML) having a Mooney viscosity of 45 and silicone rubber compound-1 (20) were used as a closed-type kneader using a Banbury blade with an internal capacity of 580 cc. Using an electric heating lab Plastomill manufactured by the company, the temperature is 15
Kneading was performed for 15 minutes under the conditions of 0 ° C. and a rotation speed of 50 rpm. The shear rate under this kneading condition is about 80 sec ^-1 . Wrap the kneaded mixture in a 6-inch roll adjusted to room temperature,
Peroxide-1 was kneaded into a blend. Examples 1-3
Table 1 shows the blending ratios adopted in. The compound thus prepared was press-vulcanized under the above conditions to obtain a 2 mm thick molded sheet. Table 1 shows the evaluation results of the hardness, the tensile test, the tear test, and the dispersibility of the molded sheet by a transmission electron microscope.

Comparative Examples 1 to 6 The rubber compositions of Comparative Examples 1 to 6 were prepared in the compounding ratios shown in Table 1 under the same conditions as in Examples 1 to 3, and molded and evaluated. The evaluation results are shown in Table 1.

[0038]

[Table 1]

In Examples 1 to 3 and Comparative Examples 4 to 6, the roll processability when the peroxide was added was such that in Examples 1 to 3, it could be easily wound around a roll within 1 minute. In Comparative Examples 4 to 6, it takes time to wind the roll.
It takes more than 5 minutes and the workability of roll processing is poor. Table 1
Is a pure rubber H containing no Mooney viscosity 45 filler.
The mixing ratio of NBR-1 (L-ML) and silicone rubber compound-1 (20) containing 20 parts of silica is 30/70.
% -70 / 30% Examples 1-3 have been shown, but outside the Mooney viscosity range of the present invention HNBR-2 (H-ML).
Comparing the evaluation results with Comparative Examples 4 to 6 using No. 3, the physical properties of the Examples of the present invention are significantly improved as compared with Comparative Examples in any of tensile strength, 100% stress, and tear strength. I understand.

In the known technique, when HNBR and silicone rubber were mixed as shown in Comparative Examples 4 to 6, the tensile strength was
Although the tear strength is lower than the additivity of both component rubbers, the use of the HNBR having a Mooney viscosity of 70 or less according to the present invention makes it possible to obtain excellent properties which greatly exceed the additivity in a wide mixing ratio of HNBR and silicone rubber. You can see that.

Further, as shown by the results of evaluation of dispersibility by a transmission electron microscope, it can be seen that in the examples of the present invention, the dispersed particle size is remarkably smaller than in the comparative examples, and excellent dispersibility is exhibited. HNBR and silicone rubber have poor affinity because the polarities of the polymers are significantly different, and
The difference in melt viscosity between commercially available HNBR and silicone rubber is remarkably large. For this reason, when HNBR and silicone rubber are mixed, the dispersion usually becomes poor as shown in Comparative Examples, making it difficult to put into practical use. Become. It can be seen that the dispersibility is improved by using the HNBR of the present invention having a Mooney viscosity of 70 or less. Thus, the composition of the present invention exhibits excellent mechanical properties by vulcanization molding.

Examples 4 to 7 HNBR Blend-1 to HNBR Blend-2, Silicone Rubber Blend-1 to Silicone Rubber Blend-2, and Peroxide-1 were blended in the proportions shown in Table 2. . Mixing, blending,
Vulcanization molding and test evaluation were carried out under the same conditions as in Examples 1-3. The shear viscosity ratio was measured by the method described above. The evaluation results are shown in Table 2. In Examples 4 to 7, the physical properties of the vulcanized molded products of the compositions obtained by mixing the compounds in which silica was previously compounded with both HNBR and silicone rubber are shown.

Comparative Examples 7 and 8 The compositions of Comparative Examples 7 and 8 were prepared under the same conditions as in Examples 1 to 3 at the compounding ratios shown in Table 2, and molding and test evaluation were performed. The evaluation results are shown in Table 2.

[0044]

[Table 2]

By comparing Examples 4 and 6 with Comparative Example 7, it can be seen that Examples 4 and 6 have improved tensile strength, elongation and tear strength. Similarly, by comparing Examples 5 and 7 with Comparative Example 8, it can be seen that Examples 5 and 7 have improved tensile strength, elongation and tear strength.

Generally, HNBR and silicone rubbers, when filled with a reinforcing filler such as Aerosil # 200,
Tensile strength, 100% stress, and tear strength are improved with the filling amount, but conversely, the viscosity difference between the HNBR compound and the silicone rubber compound becomes large, and the properties of the vulcanized molded product of the mixture are impaired. I'm afraid. In fact, in the mixed system of the HNBR compound and the silicone rubber compound, when the shear viscosity ratio of both compounds was within the range of 0.2 to 5 as shown in Examples 4 to 7, the additive system of the compound was added. It can be seen that the tensile properties and tear properties of the vulcanized products are best improved. In particular, HN
It can be seen that the tensile strength is remarkably improved when the silica content of the BR compound is about 40 parts and the silica content of the silicone rubber compound is about 50 parts.

Examples 8 to 12 HNBR compounds, silicone rubber compounds, antioxidants and peroxides shown in Table 3 were taken in predetermined amounts, and H
The NBR compound, the silicone rubber compound, and the antioxidant were mixed by a plastomill, and then a peroxide was compounded by a roll, followed by vulcanization molding, and a physical property test was conducted. Preparation of the composition,
Vulcanization molding and evaluation of physical properties were carried out under the same conditions as in Examples 1 to 3. The heat aging test is 72 at 175 ° C in a gear oven.
After the time aging test, a tensile test was performed for evaluation. The oil resistance test was evaluated by a tensile test after immersion in JIS # 3 oil at 150 ° C. for 70 hours. Cold resistance was evaluated by the Gehman torsion test. Table 3 shows the results of evaluation of physical properties.

Comparative Examples 9 to 11 The compositions of Comparative Examples 9 to 11 were prepared at the blending ratios shown in Table 3 under the same conditions as in Examples 1 to 3, and molding and evaluation of physical properties were performed. The evaluation results are shown in Table 3.

[0049]

[Table 3]

Comparing Examples 8, 10 and 11 with Comparative Example 9, Examples 8, 10 and 11 in which the iodine value of HNBR is 120 or less are excellent in tensile strength, elongation, heat aging resistance and cold resistance. It turns out to be excellent. On the contrary, the physical properties of the vulcanized molded product of Comparative Example 9 having an iodine value of 280 are remarkably inferior, and the compounding effect of different rubbers does not appear except for cold resistance,
Rather, it has a negative compounding effect. When the iodine value of the vulcanized molded product of the composition of the present invention is small, the heat aging resistance is significantly improved. There is no significant change in tensile strength, oil resistance and cold resistance.

On the other hand, comparing Examples 9 and 10 as examples in which the content of carbon-carbon unsaturated bond in the silicone rubber is different, both show excellent physical properties, but the content of carbon-carbon unsaturated bond in the silicone rubber is different. Example 9 with a small number has a slightly higher retention rate of elongation after heat aging. Although carbon black was used as the filler in Example 12, it can be seen that even if carbon black is used, the rubber composition of the present invention exhibits excellent physical properties after vulcanization molding.

As described above, the rubber composition of the present invention is excellent in roll processability in an uncrosslinked state, and the crosslinked molded product is excellent in tensile strength, tear strength, heat aging resistance, cold resistance and oil resistance. It can be seen that there is a characteristic in expressing the performance. that's all,
Although specific embodiments of the present invention have been shown based on the examples, it goes without saying that the above examples represent a part of the present invention and the present invention is not restricted thereby.

Claims (7)

[Claims] 1. A polymer component 10 comprising (A) (a) 98 to 2% by weight of hydrogenated nitrile rubber having a Mooney viscosity of 70 or less and (b) 2 to 98% by weight of organopolysiloxane.
A rubber composition, which basically comprises 0 parts by weight, (B) 200 parts by weight or less of a filler, and (C) 0.3 to 10 parts by weight of a crosslinking agent. 2. The iodine value of the hydrogenated nitrile rubber is 120.
The rubber composition according to claim 1, wherein: 3. The rubber composition according to claim 1, wherein the filler is selected from silica and carbon black. 4. A blend of (a ') 98 to 2 parts by weight of hydrogenated nitrile rubber having a Mooney viscosity of 70 or less, and 0 to 50 parts by weight of a filler with respect to 100 parts by weight of the hydrogenated nitrile rubber. Hydrogenated nitrile rubber blend, (b ') organopolysiloxane blend comprising 2 to 98 parts by weight of organopolysiloxane and 20 to 70 parts by weight of a filler per 100 parts by weight of the organopolysiloxane. (However, the total amount of the hydrogenated nitrile rubber in the component (a ') and the organopolysiloxane in the component (b') is 100 parts by weight) and, if desired, further (B ') additional filling. After mixing the agent (however, the total amount of the filler used is 200 parts by weight or less), the (C) peroxide crosslinking agent 0.3
A method for producing a rubber composition, which comprises mixing 10 to 10 parts by weight. 5. The hydrogenated nitrile rubber compound (a ′) and the organopolysiloxane compound (b ′) are mixed in a shear viscosity ratio of the compound in the range of 0.2 to 5. A method for producing the rubber composition described. 6. The method for producing a rubber composition according to claim 4, wherein the filler in the components (a ') and (b') is selected from silica and carbon black. 7. A rubber cross-linked product obtained by peroxide-crosslinking the rubber composition according to claim 1.