JPH0586229A - Halogen-containing rubber composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of providing rubber products excellent in water resistance, tensile strength, tensile stress, etc., by including an oxide, etc., of a specific element in a halogen-containing rubber composition composed of a halogen-containing rubber and calcined hydrotalcite. CONSTITUTION:The objective composition is obtained by including (B) 0.1-10 pts.wt. at least one of oxides, hydroxides, carbonates and basic salts of at least one element selected from groups II and IV of the periodic table and/or 0.1-10 pts.wt. polyhydric alcohol in (A) 100 pts.wt. halogen-containing rubber composition composed of 100 pts.wt. halogen-containing rubber (e.g. chlorinated PE) and 0.1-40 pts.wt. calcined hydrotalcite.

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 capable of obtaining a halogen-containing rubber product excellent in water resistance, tensile strength and tensile stress. 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 and Group IV elements,
The present invention relates to a halogen-containing rubber composition capable of obtaining a halogen-containing rubber product having excellent tensile strength and tensile stress.

[0002]

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

For example, when a compound of 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. Deterioration of water resistance leads to deterioration of insulation performance of vulcanized rubber products. It is presumed that a halide and / or a basic halide having a strong hygroscopic property is generated from the compound of the above element during the vulcanization treatment. Therefore, for applications in which water resistance and chemical resistance are strongly required, it has been usual to use a group IV element such as a lead compound such as lead oxide as an acid acceptor. However, lead compounds have problems that mechanical strength, heat resistance and the like are not satisfactory due to slow vulcanization rate and low degree of vulcanization.

As a solution to the problem of the acid acceptor of the halogen-containing rubber, it has been reported that the use of calcined hydrotalcite or its surface-treated product as the acid acceptor significantly improves the water resistance ( Japanese Patent Fair 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 lowered.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned conventional acid acceptors, and is a halogen-containing rubber product excellent in water resistance and mechanical strength such as tensile strength and tensile stress. To provide a halogen-containing rubber composition.

[0006]

SUMMARY OF THE INVENTION The present invention comprises 100 parts by weight of a halogen-containing rubber and 0.1 to 4 calcined hydrotalcite.
A halogen-containing rubber composition consisting of 0 parts by weight, preferably 5 to 20 parts by weight, is added to an oxide, hydroxide, carbonate of at least one element selected from Group II and Group IV of the periodic table and At least one kind of basic salt is contained in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and / or a polyhydric alcohol of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight. A halogen-containing rubber composition is provided.

The present inventor has conducted extensive studies to solve the above problems, and as a result, the halogen-containing rubber composition of the present invention was
It was found that a halogen-containing rubber product excellent in water resistance, tensile strength, tensile stress, etc. can be provided, and the present invention was completed.

The calcined hydrotalcite used in the present invention is natural hydrotalcite Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O or the 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. , N is 1 or 2, x ≧ 2, z ≧ 2, m
Indicates a positive number. ] Synthetic hydrotalcite of 300
It was baked at ~ 800 ° C. The surface-treated product is a product obtained by surface-treating calcined hydrotalcite with an anionic surfactant.

The calcined hydrotalcite or the surface-treated product thereof captures halogens generated during vulcanization, and when moisture is present, the calcined hydrotalcite returns to hydrotalcite, so that the halide has a strong hygroscopic property. And / or does not form a basic halide. For this reason,
It is presumed that a halogen-containing rubber product having excellent water resistance can be obtained. However, since calcined hydrotalcite is a solid solution of divalent and trivalent metals, it has a lower halogen-neutralizing ability than divalent metal oxides such as magnesium oxide. It is presumed that this lowers the vulcanization characteristics of the halogen-containing rubber composition, which in turn lowers the mechanical strength such as tensile stress of the halogen-containing rubber product. The present invention, the problem of the halogen-containing rubber composition in combination with a calcined hydrotalcite or a surface-treated product thereof, oxide of at least one element selected from Group II and Group IV of the periodic table, water The problem was solved by further containing at least one of an oxide, a carbonate and a basic salt. That is, magnesium oxide, magnesium hydroxide, calcium oxide,
By using calcium hydroxide or the like together, the acid neutralizing ability of the entire acid acceptor is improved, and the vulcanization characteristics are improved,
Furthermore, they have found that the water resistance is not impaired.

Although the reason for this is not clear, the highly hygroscopic halide and / or basic halide formed during vulcanization reacts with the calcined hydrotalcite when the moisture content is high, so that the crystal of hydrotalcite is formed. It seems that it was incorporated into.

Polyhydric alcohols, which are generally used as vulcanization aids, are used in combination with magnesium oxide or the like as an acid acceptor in order to extract halogen from a halogen-containing rubber during vulcanization. However, in this case, if the degree of vulcanization is improved,
A large amount of halides such as magnesium chloride and / or basic halides are produced and the water resistance is reduced.
Even in this case, as described above, the combined use with the calcined hydrotalcite or its surface-treated product results in water resistance,
A halogen-containing rubber composition capable of providing a halogen-containing rubber product excellent in 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, fluororubber, chlorinated butyl rubber, brominated butyl rubber, chlorinated ethylene-propylene copolymer, chlorine-containing acrylic rubber, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-acrylglycidyl ether copolymer and the like.

A vulcanizing agent, a vulcanization aid, a filler, a softening agent, an antiaging agent and the like necessary for vulcanization may be added to the halogen-containing rubber composition of the present invention as required. The addition amount of these 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 with reference to Examples.

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

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

Table 1Example Comparative example  1 2 3 1 2 2 Chlorinated polyethylene 100 100 100 100 100 100 DCP 2 2 2 2 2 TAIC 2 2 2 2 2 MgO 1 3 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)
Honkasei Co., Ltd.) MgO (trade name MA-150, Kyowa Chemical Industry Co., Ltd.) KW-2200 (calcined hydrotalcite, synthetic hide)
The rotalcite is fired at 600 ° C. for 2 hours) The test results are shown in Table 2.

Table 2Example Comparative example  1 2 3 1 2 100% Tensile stress 30 32 36 36 29 33 200% Tensile stress 73 78 78 91 62 91 91 Tensile strength 131 152 150 121 121 130 Elongation (%) 277 283 270 280 247 Hardness 63 65 65 62 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 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.².

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

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 5 5 accelerator 22 0.5 0.5 MgO 1-4 KW-2200 888 -Note: Chloroprene W (Neoprene W, trade name, Showa Den
Engineering / Dupont Co., Ltd.) SRF carbon (trade name, manufactured by Tokai Carbon Co., Ltd.) Zinc flower (No. 1, manufactured by Masaoka Chemical Co., Ltd.) Accelerator 22 (trade name, Sansera-22, Sanshin Chemical Co., Ltd.) )
(Production) MgO and KW-2200 are the same as in Example 1.

The test results are shown in Table 4.

Table 4Example Comparative example  4 3 4 100% Tensile stress 24 22 27 200% Tensile stress 122 122 108 138 Tensile strength 230 240 232 Elongation (%) 476 521 450 Hardness 62 60 62 Water resistance 70 ° C. 7 days ΔV (%) 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 10.21 21 days ΔV (%) 13.3 13.2 24.0 35 days ΔV (%) 16.9 17.2 43.2 Note: The measuring method of each characteristic value is the same as in Example 1.

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

Table 5 Examples Comparative Examples 5 6 7 8 5 6 7 Chlorosulfonated Polyethylene 100 100 100 100 100 100 100 100 100 SRF Carbon 50 50 50 50 50 50 50 50 Process Oil 10 10 10 10 10 10 10 10 Accelerator TRA 2 2 2 2 2 2 2 KW-2200 8 8 15 15 15 8 15-MgO-2-2-4-4 pentaerythritol 3 3 3 3-3-3 Note: Chlorosulfonated polyethylene (trade name Hypalon 40, manufactured by DuPont). Process oil (Brand name Diana Process NM-26,
Idemitsu Co., Ltd. Accelerator TRA (trade name: Nox Cellar TRA, manufactured by Ouchi Shinko Chemical Co., Ltd.) Pentaerythritol (trade name: Pentalit 300, Koei Chemical Co., Ltd.) 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 71 80 45 48 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 76 77 78 71 74 74 Water resistance 70 ° C. 7 days △ V (%) 11.6 12.0 6.8 7.0 7.0 6.6 6.7 18.7 21 days △ V (%) 18.1 18.8 8.7 8.9 16.9 8.4 35.0 35 days △ V (%) 21.4 22.3 9.4 9.7 20.8 10. 1 47.9 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 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.

Claims (2)

[Claims] 1. A halogen-containing rubber composition comprising 100 parts by weight of a halogen-containing rubber and 0.1 to 40 parts by weight of calcined hydrotalcite, and at least one selected from Group II and Group IV of the periodic table. Halogen containing 0.1 to 10 parts by weight of at least one of oxides, hydroxides, carbonates and basic salts of elements, and / or 0.1 to 10 parts by weight of polyhydric alcohol. Containing rubber composition. 2. The halogen-containing rubber composition according to claim 1, wherein the calcined hydrotalcite contains halogen-containing natural hydrotalcite or synthetic hydrotalcite that has been surface-treated with an anionic surfactant. Rubber composition.