JPH0643541B2 - Blended rubber composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a blend rubber composition of a norbornene-containing acrylic rubber and an allyl glycidyl ether-containing epichlorohydrin-based polymer rubber.

[Prior Art] Conventionally, a blend rubber composed of an acrylic rubber and an epichlorohydrin-based polymer rubber, and a conventionally known vulcanizing agent, for example,
A vulcanized composition with 2-mercaptoimidazoline is already known, and it is effective for improving heat resistance by using an acrylic rubber and improving cold resistance, water resistance, elasticity and tensile strength by using an epichlorohydrin-based polymer rubber. It has been known.

[Problems to be solved by the invention]

However, both vulcanizing agents are usually different, and even vulcanizing agents common to both vulcanizing agents have different vulcanizing speeds, so that in terms of processability, vulcanizing characteristics, or physical properties after vulcanization. , But the result was not always sufficient. That is, in the above-mentioned vulcanizing agent (2-mercaptoimidazoline) capable of vulcanizing both of the above rubbers, the vulcanization rate of the acrylic rubber is slow, and therefore the blended rubber vulcanizate with the epichlorohydrin polymer rubber However, satisfactory results were not obtained in vulcanization properties, tensile strength and compression set.

The present inventor has conducted earnest research to obtain a composition capable of effectively co-vulcanizing a blend rubber of an acrylic rubber and an epichlorohydrin-based polymer rubber, and as a result, a norbornene-containing acrylic rubber and an acluglycidyl ether-containing epichlorohydrin-based heavy rubber have been obtained. The blended rubber and the blended rubber do not exhibit the general tendency of the conventional covulcanization as described above, and the vulcanization proceeds rapidly, and the vulcanized product has vulcanization characteristics, tensile strength, and compression set resistance. The present invention was found to provide excellent properties in heat resistance and heat aging resistance, and has reached the present invention.

[Means for solving problems]

The present invention relates to (a) norbornene-containing acrylic rubber 99 to 70
And (b) 1 to 30 parts by weight of epichlorohydrin-based polymer rubber containing allyl glycidyl ether (a) and (b)
Blend rubber composition containing 0.1 to 10 parts by weight of a thiuram-based vulcanizing agent, 0.1 to 5 parts by weight of sulfur, and 0.1 to 50 parts by weight of a metal compound based on 100 parts by weight of the blend rubber. .

The norbornene-containing acrylic rubber used in the present invention is composed of 40 to 99.9 parts by weight of an acrylate-based monomer and 10 to 10 of the norbornene-containing monomer as a crosslinking component.
It is a copolymer comprising 0.1 parts by weight and 30 to 0 parts by weight of at least one other monomer copolymerizable with these monomers.

Examples of acrylic acid ester-based monomers include lower alkyl acrylates such as methyl acrylate and n-butyl acrylate, methoxymethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl acrylate, and 2
-Alkoxyalkyl acrylates such as ethoxyethyl acrylate. Examples of the norbornene-containing monomer include ethylidene norbornene, vinylidene norbornene and norbornadiene. Other copolymerizable monomers include vinyl or vinylidene compounds such as acrylonitrile, methacrylonitrile, styrene and -methylstyrene, and polyene compounds such as divinylbenzene, diallyl phthalate and alkylene glycol diacrylate.

The allyl glycidyl ether-containing epichlorohydrin-based polymer rubber of the present invention means epichlorohydrin-allyl glycidyl ether copolymer rubber, epichlorohydrin-
Binary copolymer rubbers such as ethylene oxide-allyl glycidyl ether copolymer rubbers and terpolymer rubbers may be mentioned.

In the case of a copolymer rubber, its constituent components, epichlorohydrin, are 20 to 99 mol%, and other epoxides are 1 to
80 mol% is preferable in terms of physical properties of the vulcanized product. For example,
In the above epichlorohydrin-allyl glycidyl ether copolymer rubber, epichlorohydrin 80-9 is used.
0 mol% and 1-20 mol% allyl glycidyl ether rubber, epichlorohydrin-ethylene oxide-
In the allyl glycidyl ether terpolymer rubber, epichlorohydrin 25 to 80 mol%, ethylene oxide 20 to 75 mol% and allyl glycidyl ether 1 to 20 mol% are preferably used.

Examples of the thiuram-based vulcanizing agent of the present invention include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethyl thiuram disulfide, and tetrabutyl thiuram disulfide.

Examples of the metal compound of the present invention include oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites of Group IIa metals of the periodic table, and Group IVa metals of the periodic table. There are oxides, basic carbonates, basic carboxylates, basic phosphites, basic sulfites and the like. Specific examples include magnesia, magnesia hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, magnesium phosphite, Calcium phosphate, zinc white, tin oxide, litharge, red lead, dibasic phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite, basic lead sulfite, tribasic Examples thereof include acidic lead sulfate.

The blending ratio of the blended rubber composition of the present invention is such that 99-70 parts by weight of norbornene-containing acrylic rubber and allyl glycidyl ether-containing epichlorohydrin-based polymer rubbers 1 to 3 are used.
With respect to 100 parts by weight of the blend rubber consisting of 0 parts by weight,
Thiuram-based vulcanizing agent 0.1 to 10 parts by weight, preferably 0.1.
5 to 5 parts by weight, sulfur 0.1 to 5 parts by weight, preferably 0.1.
A range of 5 to 2 parts by weight and a metal compound of 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight is suitable.

When the norbornene-containing acrylic rubber is less than 70 parts by weight in the blending ratio of the rubber component of the blended rubber of the composition of the present invention, the heat resistance of the vulcanized product cannot be substantially improved. When the amount of the allyl glycidyl ether-containing epichlorohydrin-based polymer rubber is less than 1 part by weight, the vulcanization characteristics of the composition are deteriorated and the vulcanized physical properties cannot be expected to have a synergistic effect.

In the composition of the present invention, in addition to the above, other compounds such as a reinforcing agent, a filler, a plasticizer, a processing aid, an antioxidant, a pigment and a flame retardant may be optionally compounded. You can

The method for mixing the composition of the present invention is not particularly limited, and for example,
A blending method, a master batch method or the like can be performed using a two-roll, Banbury mixer, kneader blender or the like. The mixing temperature is 50 to 150 ° C, preferably 80 to 100 ° C.

Conventionally, in the case of vulcanizing an acrylic rubber and an epichlorohydrin-based polymer, when a conventionally known vulcanizing agent is used, the vulcanization speed of the epichlorohydrin-based polymer rubber is relatively faster than that of the acrylic rubber. However, since the norbornene-containing acrylic rubber used in the present invention contains an unsaturated double bond at the cross-linking site, using a thiuram-based vulcanizing agent and sulfur and a metal compound results in a very high vulcanization rate. A fast rubber composition is obtained.

Therefore, both of the above rubbers can be vulcanized in the same vulcanization system, and the blended rubber vulcanizate was sufficiently satisfactory in vulcanization characteristics, tensile strength and compression set.

〔Example〕

 The present invention will be described more specifically by the following examples.

All parts are parts by weight.

Examples 1 to 3 and Comparative Examples 1 to 3 Each of the formulations shown in Table 1 was kneaded with an open roll at 80 to 90 ° C and formed into a sheet, which was put into a mold and pressure-molded at 180 ° C for 5 minutes, and then After vulcanization in an oven at 160 ° C. for 16 hours. Various physical property tests were conducted on each of the obtained blends, and the results are shown in Table 2.

The vulcanized state of the examples of the present invention and the acrylic rubber alone is shown in the graph of FIG. As can be seen from the drawing, in A, the torque value reaches the maximum in a short time, then shows the flatness of vulcanization, and the torque value at a constant vulcanization time is significantly higher than that in B. it is obvious.

From the above results, the blended rubber composition of the present invention, as shown in Comparative Example 1, does not deteriorate the heat aging resistance and compression set resistance of the norbornene-containing acrylic rubber single composition, and has the drawback of acrylic rubber. Certain tensile strength and low temperature properties can be increased. Further, in Comparative Example 2 in which the rubber blend ratio is outside the range of the present invention, it can be seen that the heat aging resistance and compression set resistance of the acrylic rubber are significantly reduced as compared with the examples of the present invention.

〔The invention's effect〕

As described above, according to the blended rubber composition of the present invention, it is possible to improve the tensile strength and the low temperature characteristics without deteriorating the physical properties of the acrylic rubber, and also to improve the processability and the vulcanization characteristics. It has excellent features such as improvement.

[Brief description of drawings]

The drawings are graphs showing examples of the present invention and the vulcanized state of acrylic rubber alone. A: Example 3 B: Comparative example 1

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Claims (1)

[Claims] Claim 1. (a). Acrylic rubber containing norbornene 9
9 to 70 parts by weight (b). 1 to 30 parts by weight of allyl glycidyl ether-containing epichlorohydrin-based polymer rubber, 0.1 to 10 parts by weight of thiuram-based vulcanizing agent, and 0. 1
A blended rubber composition comprising .about.5 parts by weight and 0.1 to 50 parts by weight of a metal compound.