JP2864061B2 - Halogen-containing rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a halogen-containing rubber composition from which a halogen-containing rubber product excellent in water resistance, tensile strength and tensile stress can be obtained. More specifically, halogen-containing rubber, calcined hydrotalcite, Periodic Table II
Water resistance consisting of oxides, hydroxides, carbonates, basic salts and / or polyhydric alcohols of Group IV elements
The present invention relates to a halogen-containing rubber composition from which a halogen-containing rubber product having excellent tensile strength and tensile stress can be obtained.

[0002]

2. Description of the Related Art As an acid acceptor for halogen-containing rubbers, usually, oxides, hydroxides, carbonates, basics, and the like of elements of Groups II and IV of the periodic table such as magnesium oxide, calcium oxide, and lead oxide. Salts or epoxy compounds have been used. However, these acid acceptors have the following problems.

For example, when a compound of a Group II element of the periodic table is used as an acid acceptor for a halogen-containing rubber, the water resistance of the vulcanized rubber obtained during the heat treatment deteriorates. The deterioration of the water resistance leads to a decrease in the insulation performance of the vulcanized rubber product. It is presumed that during the vulcanization treatment, a halide and / or a basic halide having a strong hygroscopic property is generated from the compound of the above element. For this reason, for applications requiring high water resistance and chemical resistance, it has been usual to use a Group IV element, for example, a lead compound such as lead oxide, as the acid acceptor. However, lead compounds have problems such as unsatisfactory mechanical strength, heat resistance, and the like due to low vulcanization rate and low degree of vulcanization.

In order to solve the problems of the acid acceptor of the halogen-containing rubber, it has been reported that use of calcined hydrotalcite or a surface-treated product thereof as the acid acceptor significantly improves the water resistance. 1-3085
No. 6). However, the use of calcined hydrotalcite or a surface-treated product thereof has a problem that the vulcanization rate is delayed and the tensile strength and tensile stress are reduced.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned conventional acid acceptors, and provides a halogen-containing rubber product having excellent water resistance and mechanical strength such as tensile strength and tensile stress. Is provided.

[0006]

SUMMARY OF THE INVENTION The present invention provides a fired hydrotalcite obtained by firing 100 parts by weight of a halogen-containing rubber and natural hydrotalcite or synthetic hydrotalcite in a temperature range of 300 ° C to 800 ° C. Parts by weight of at least one element selected from the group consisting of oxides, hydroxides, carbonates and basic salts of at least one element selected from Groups II and IV of the periodic table. To 10 to 10 parts by weight of a polyhydric alcohol and / or 0.1 to 10 parts by weight of a polyhydric alcohol.

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, the halogen-containing rubber composition of the present invention
The present inventors have found that a halogen-containing rubber product excellent in water resistance, tensile strength, tensile stress and the like can be provided, and completed the present invention.

[0008] calcined hydrotalcites used in the present invention include natural hydrotalcite _{Mg 6 Al 2 (OH) 16} CO 3 · 4H 2 O or formula ^{_{(1) M 2+ x Al 2}} (OH) 2x + 6-nz (A ⁿ⁻ ) · mH ₂ O (1) [wherein, M ²⁺ represents Mg or Zn, A ⁿ⁻ represents an n-valent anion, and x, z and m are numbers satisfying the following conditions, respectively. Where n is 1 or 2, x ≧ 2, z ≧ 2, m
Indicates a positive number. ] Of 300 synthetic hydrotalcite
Fired at ８００800 ° C. The surface-treated product is obtained by subjecting calcined hydrotalcite to a surface treatment with an anionic surfactant.

The calcined hydrotalcite or its surface-treated product captures the halogens emitted during vulcanization, and when there is moisture, the calcined hydrotalcite returns to the hydrotalcite, so that the halide having a strong hygroscopic property is obtained. And / or does not produce basic halides. For this reason,
It is estimated that a halogen-containing rubber product having excellent water resistance can be obtained. However, calcined hydrotalcite is a solid solution of divalent and trivalent metals, and therefore has a lower neutralizing capacity for halogen than divalent metal oxides such as magnesium oxide. It was presumed that this would reduce the vulcanization properties of the halogen-containing rubber composition and, consequently, the mechanical strength such as tensile stress of the halogen-containing rubber product. The present invention solves the problems of the halogen-containing rubber composition using the calcined hydrotalcite or its surface-treated product in combination with an oxide of at least one element selected from Groups II and IV of the periodic table, and water. The problem has been solved by further adding at least one of oxides, carbonates and basic salts. That is, magnesium oxide, magnesium hydroxide, calcium oxide,
By using calcium hydroxide or the like in combination, the acid neutralizing ability of the entire acid acceptor is improved, and the vulcanization characteristics are improved,
Furthermore, it was found that the water resistance was not impaired.

Although the reason for this is not clear, the highly hygroscopic halide and / or basic halide formed during the vulcanization reacts with the calcined hydrotalcite when the moisture content is high, resulting in the formation of hydrotalcite crystals. Probably because it was incorporated in.

Polyhydric alcohols generally used as vulcanization aids are used in combination with magnesium oxide or the like as an acid acceptor in order to extract halogen during vulcanization from a halogen-containing rubber. However, in this case, if the degree of vulcanization is improved,
A large amount of a halide such as magnesium chloride and / or a basic halide is formed, and the water resistance is reduced.
Also in this case, as described above, the combined use with the calcined hydrotalcite or its surface-treated product provides water resistance,
A halogen-containing rubber composition capable of providing a halogen-containing rubber product having excellent tensile stress and the like was obtained.

The polyhydric alcohol is a polyhydric alcohol generally used as a vulcanization aid such as pentaerythritol and dipentaerythritol.

Examples of the halogen-containing rubber used in the present invention include the following. Chlorinated polyethylene, chlorinated polypropylene, chlorosulfonated polyethylene,
Polyepichlorohydrin, polychloroprene, fluoro rubber, chlorinated butyl rubber, brominated butyl rubber, chlorinated ethylene-propylene copolymer, chlorinated acrylic rubber, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-acryl glycidyl ether copolymer and the like.

[0014] To the halogen-containing rubber composition of the present invention, a vulcanizing agent and a vulcanizing aid necessary for vulcanization, as well as a filler, a softening agent, an antioxidant and the like can be added as required. The amount of these additives is selected from a range that does not adversely affect water resistance, tensile stress, and the like. Hereinafter, the present invention will be described in more detail based on examples.

Examples 1 to 3 and Comparative Examples 1 and 2 The compositions having the compositions shown in Table 1 were kneaded by an open roll and then pressed at 184 ° C. for 10 minutes to effect crosslinking.

The measuring method of each characteristic value in the following test is as follows. Tensile test: The test piece was measured using a dumbbell No. 3 at a tensile speed of 500 mm / min using a Shopper type tensile tester according to JIS K6031. Hardness: Using a spring type hardness tester type A, JIS
It was measured based on K6031. Water resistance test: A test piece of 2 × 5 × 0.3 cm was immersed in water at a predetermined temperature for a certain number of days, and then a change in volume was measured. Based on JIS K6031.

Table 1Example Comparative example  1 2 3 1 2 Chlorinated polyethylene 100 100 100 100 100 100 DCP 2 2 2 2 2 TAIC 2 2 2 2 2 2 MgO 13 5 -10 KW-2200 10 10 10 10-Note: Chlorinated polyethylene (trade name Eraslen TR, Showa
DCP (trade name, Perhexa 25B, manufactured by NOF Corporation) TAIC (trade name, trisialyl isocyanurate, Japan)
MgO (product name: MA-150, manufactured by Kyowa Chemical Industry Co., Ltd.) KW-2200 (fired hydrotalcite, synthetic hide)
Table 2 shows the test results.

Table 2Example Comparative example  1 2 3 1 2 100% tensile stress 30 32 36 29 33 200% tensile stress 73 78 91 62 91 Tensile strength 131 152 150 121 130 130 Elongation (%) 277 283 270 280 247 Hardness 63 65 65 65 65 65 Water resistance 70 ° C. 7 Day △ V (%) 4.2 4.7 5.7 3.0 9.1 21 days △ V (%) 6.7 7.2 7.9 4.6 15.3 35 days △ V (%) 7.9 8.4 8.7 5.7 19.0 90 ° C 7 days △ V (%) 6.6 6.5 6.9 5.0 14.7 21 days △ V (%) 8.0 7 .2 7.2 5.8 24.5 35 days △ V (%) 8.0 7.2 7.2 6.0 31.4 Note: The unit of tensile stress and tensile strength is kg / cm^Two.

Example 4 and Comparative Examples 3 and 4 The compositions having the compositions shown in Table 3 were kneaded with an open roll and then pressed at 153 ° C. for 30 minutes to effect crosslinking.

Table 3Example Comparative example  4 3 4 Chloroprene W 100 100 100 Stearic acid 0.5 0.5 0.5 SRF carbon 30 30 30 Zinc white 5.55 Promoter 22 0.5 0.5 0.5 MgO 1-4 KW-2200 88 -Note: Chloroprene W (neoprene W, trade name, Showa Den
SRF Carbon (trade name, manufactured by Tokai Carbon Co., Ltd.) Zinc flower (No. 1, manufactured by Masaoka Chemical Co., Ltd.) Accelerator 22 (trade name, Sancera-22, Sanshin Chemical Co., Ltd.) )
Manufacture) MgO and KW-2200 are the same as those in Example 1.

Table 4 shows the test results.

Table 4Example Comparative example  4 3 4 100% tensile stress 24 22 27 200% tensile stress 122 108 138 Tensile strength 230 240 232 Elongation (%) 476 521 450 Hardness 62 60 62 Water resistance 70 ° C 7 days △ V (%) 5.3 5.2 7.0 21 days △ V (%) 8.9 9.8 13.2 35 days △ V (%) 10.6 10.6 22.1 90 ° C 7 days △ V (%) 8.9 8.6 10.2 21 days ΔV (%) 13.3 13.2 24.0 35 days ΔV (%) 16.9 17.2 43.2 Note: The method of measuring each characteristic value is the same as in Example 1.

Examples 5 to 8 and Comparative Examples 5 to 7 The compositions having the compositions shown in Table 5 were kneaded with an open roll and then pressed at 153 ° C. for 30 minutes to effect crosslinking.

Table 5 Example Comparative Example 5 6 7 8 5 6 7 Chlorosulfonated polyethylene 100 100 100 100 100 100 100 100 SRF carbon 50 50 50 50 50 50 50 Process oil 10 10 10 10 10 10 10 10 Accelerator TRA 22 2 2 2 2 2 2 KW-220 08 88 15 15 815 -MgO-2-2-2-4-pentapentaerythritol 3 33 33 3--3 Note: Chlorosulfonated polyethylene (trade name: Hypalon 40, manufactured by DuPont) Process oil (trade name Diana Process NM-26,
Accelerator TRA (trade name Noxeller TRA, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Pentaerythritol (trade name Pentarit 300, manufactured by Koei Chemical Co., Ltd.) The test results are shown in Table 6.

Table 6 Example Comparative Example 5 6 7 8 5 6 7 100% tensile stress 57 65 71 80 45 48 67 200% tensile stress 160 180 181 195 119 119 106 188 Tensile strength 232 235 231 230 192 143 239 Elongation (% ) 283 280 265 258 340 421 279 Hardness 74 76 77 78 71 74 74 Water resistance 70 ° C. 7 days △ V (%) 11.6 12.0 6.8 7.0 10.6 6.7 18.7 21 days ΔV (%) 18.1 18.8 8.7 8.9 16.9 8.4 35.0 35 days ΔV (%) 21.4 22.3 9.4 9.7 20.8 10. 147.9 90 ° C. 7 days △ V (%) 16.6 17.2 8.4 8.6 15.4 7.9 42.8 21 days △ V (%) 27.1 27.9 10.7 11.1 27.6 11.2 83.1 35 days @V (%) 34.7 3 .0 12.0 12.5 37.7 15.0 119.5 Note: method of measuring the characteristic values are the same as in Example 1.

[0026]

According to the present invention, there is provided a halogen-containing rubber composition capable of providing a halogen-containing rubber product having excellent mechanical properties such as water resistance and tensile stress.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5:05) (C08K 13/02 3:22 3:26 5:05) (C08K 13/06 9:04 3: 225) : 05) (C08K 13/06 9:04 3:26 5:05)

Claims (2)

(57) [Claims] (1) 100 parts by weight of a halogen-containing rubber and natural rubber
30 hydroidite or synthetic hydrotalcite
A halogen-containing rubber composition comprising 0.1 to 40 parts by weight of calcined hydrotalcite calcined in a temperature range of 0 ° C. to 800 ° C., wherein at least one element selected from Groups II and IV of the periodic table Halogen containing at least one of oxides, hydroxides, carbonates and basic salts of 0.1 to 10 parts by weight, and / or 0.1 to 10 parts by weight of a polyhydric alcohol. Rubber composition. 2. A halogen-containing rubber composition according to claim 1, wherein, calcined hydrotalcites are halogen-containing rubber composition, including those surface-treated with A anions surfactant.