JPS6149338B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of co-vulcanizing a halogen-containing polymer and a diene rubber in the same vulcanization system. Co-vulcanization of a mixture of a halogen-containing polymer and a diene rubber is important because it can improve the oil resistance, ozone resistance, and heat resistance of the diene rubber. However, halogen-containing polymers and diene-based rubbers have completely contradictory reactivities during vulcanization and their reactive parts are different, so it is difficult to vulcanize these polymer mixtures using the same sulfur system and under the same conditions. It was hot. That is, in a halogen-containing polymer, C-X (X represents a halogen) in the molecule is the reactive moiety and is vulcanized by a nucleophilic substitution reaction of a vulcanizing agent, but in diene rubber, the C-X in the molecule =C is a reactive moiety and is vulcanized by radical addition reaction of a vulcanizing agent. Therefore, in order to simultaneously vulcanize these polymeric materials, it is necessary to use a vulcanizing agent that simultaneously reacts with C-X and C=C bonds under the same conditions and has similar vulcanization rates. In order to cause the above two types of reactions with one compound, it is necessary to use a difunctional compound in which one functional part undergoes a nucleophilic substitution reaction with C-X, and the other functional part undergoes a radical addition to C=C. Although a specific vulcanizing agent is desirable, no single compound has been found to achieve this goal. As a result of intensive research, the present inventors found that at least one kind of 2-substituted-4,6-dithiol-s-triazine detailed below and -N=N- group, -
The present invention was accomplished by discovering that a mixture of a halogen-containing polymer and a diene rubber can be simultaneously vulcanized by coexisting at least one compound containing an S—S— group or a —S—N— group. It has arrived. Halogen-containing polymers to which the vulcanization method of the present invention can be applied include polyvinyl chloride, shrimp chlorohydrin polymer, fluorocarbon rubber, and chlorosulfonated polyethylene. Diene rubbers are rubbers made of polymers and copolymers containing monomers having a diene structure, such as polybutadiene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene rubber, chloroprene rubber, and isoprene rubber. , propylene-butadiene rubber, etc. can be cited as representative examples. The first group of compounds used in the present invention has the following formula: [However, R is SR′ or NR′, R″, R′ and
R'' are the same or different hydrogen atom, alkyl group (1 to 4 carbon atoms), or phenyl group; M is hydrogen atom, Na, K, Li, 1/2Ca, 1/2Mg, 1/2Ba, 1/2
Represents Sr, 1/2Zn, 1/2Ni or 1/2Cu] 2-Substituted-4,6-dithiol-s-
It is a triazine derivative. The amount of the triazinethiol derivative added is not particularly limited, but it is usually 0.1 to 10 parts, preferably 0.5 to 5 parts, per 100 parts (by weight; the same shall apply hereinafter) of the mixture of halogen-containing polymer and diene rubber.
It is sufficiently effective with the addition amount of 50%. Adding a large amount of 10 parts or more only increases the crosslinking density and is not harmful. The second group of compounds used in the present invention, that is, compounds having -N=N-, -S-S-, or -N-S- groups in the molecule, are: NH ₂ OCN=NCONH ₂ , A compound represented by At least one of these compounds is usually added in an amount of 0.1 to 5 parts per 100 parts of the mixture of the halogen-containing polymer and the diene rubber. If more than 5 parts are added, some halogen-containing polymers may not be vulcanized. However,
In the case of highly vulcanizable rubber such as CHC (epichlorohydrin-ethylene oxide copolymer rubber), it is effective to add 5 parts or more, and the amount to be added cannot be determined unambiguously. In the present invention, the mixing ratio of the halogen-containing polymer and diene rubber is not particularly limited as long as both are mixed even if the content of one is small.
They are usually mixed in a weight ratio of 1:9 to 9:1. The above-mentioned 2-substituted-4,6-dithiol-s-triazine derivative used in the present invention is already being used as a crosslinking agent for halogen-containing polymers, but the derivative alone does not substantially cause crosslinking reaction for diene rubber. It doesn't progress. Therefore, when only the triazine derivative is added to a mixture of a halogen-containing polymer and a diene rubber, only the halogen-containing polymer is vulcanized, but co-vulcanization with the diene rubber does not occur. On the other hand, some of the compounds in the second group mentioned above are used as vulcanization aids when sulfur vulcanization of diene rubber is carried out, but the crosslinking reaction is generally slow and the use of these compounds alone does not have a practically effective vulcanization effect. I can't get it. However, according to the present invention, the 2-substituted-4,6-dithiol-s-triazine derivatives of the first group and the -N=N- group, -S-S- group, or -N
When a compound containing an -S- group is allowed to coexist, the vulcanization reaction is significantly promoted and proceeds efficiently due to some kind of interaction between them, without using any sulfur, and a co-vulcanizate with excellent physical properties can be obtained. It was found that According to the present invention, a mixture consisting of a halogen-containing polymer and a diene rubber is mixed with at least one of the compounds of the first group and at least one of the compounds of the second group.
In the presence of seeds, generally 150-200°C, preferably
A co-vulcanizate with excellent physical properties can be obtained by heating at 160-180°C for 20-50 minutes. In the present invention, various additives generally used for halogen-containing polymers and diene rubbers can be added together with the compounds of the first and second groups. Especially MgO, CaO, ZnO, BaO,
It is preferable to add 0.2 to 10 parts of a metal oxide such as SrO, and the addition of these metals significantly accelerates the vulcanization reaction. Also, fillers such as metal soaps, organotin stabilizers, epoxy stabilizers, phosphate ester stabilizers, plasticizers, CaCO ₃ , TiO ₂ , and carbon, which are usually added to halogen-containing polymers; added to diene rubbers. Stearic acid amine type anti-aging agents, phenol type anti-aging agents, processing aids, etc. can be appropriately blended as necessary. The present invention will be explained below with reference to Examples. All "parts" mean "parts by weight" unless otherwise specified. Examples 1 to 3 and Comparative Examples 1 to 2 SBR (Nipole 1502, manufactured by Nippon Zeon Co., Ltd.) and polyvinyl chloride (103EP, manufactured by Nippon Zeon Co., Ltd.) were
A total of 100 parts and 2 parts of the stabilizer Ferro 675C (manufactured by Nissan Ferro Co., Ltd.) were added at the mixing ratio shown in the table for 10 minutes at 175℃.
Roll blend for a minute. Add to this the information listed in Table 1.
4 parts of DB, 2 parts of DM, 2 parts of ZnO, 5 parts of MgO,
1 part stearic acid, Antige W-300 (4,
Add 2 parts of 4'-butylidene bis (6-tertiary, butyl-m-cresol, anti-aging agent, manufactured by Kawaguchi Kagaku Kogyo Co., Ltd.) and blend for 10 minutes at 100°C.
The obtained kneaded product was pressed at 180°C for 20 minutes to obtain a co-vulcanized product. 0.2 g of the vulcanizate sample was added to 20 ml of cyclohexanone, held at 50°C for 24 hours, and the insoluble matter was measured. The results are listed in Table 1. Insoluble rate = weight of insoluble matter after treatment / weight of sample before treatment x 100 (
%)

[Table] Both SBR and PVC dissolve in cyclohexanone, so when a co-vulcanized product is treated in cyclohexanone, if the insolubility is low, it means that they are not co-vulcanized. From the results shown in Table 1, it is clear that in Examples 1 to 3 in which DB and DM were co-existing, the insolubility was high and co-vulcanizates were obtained. On the other hand, in Comparative Example 1 in which only DB was added,
Since only PVC reacts but SBR does not, the insolubility rate is less than 50%, and Comparative Example 2 in which only DM was added
In both SBR and PVC, there was almost no reaction and the insolubility rate was extremely low, indicating that co-vulcanization did not actually occur in either case. Examples 4 to 11 CR (chloroprene rubber, W-type manufactured by Showa Neoprene Co., Ltd.) and PVC (manufactured by Nippon Zeon Co., Ltd.,
103EP) at the mixing ratio shown in Table 2, 3 parts of a stabilizer (manufactured by Tokyo Fine Chemical Co., Ltd., RP-101, zinc stearate, barium stearate, and calcium stearate complex) was added to a total of 100 parts, and the mixture was heated at 160°C.
Roll blend for 10 minutes. Add to this the compounding agents listed in Table 2, 5 parts of MgO, and Antige (W-300).
2 parts were added and roll blended at 60 to 70°C for 5 minutes, and the resulting kneaded product was pressed at 170°C for 20 minutes to obtain a co-vulcanized product. A co-vulcanizate sample was placed in tetrahydrofuran (abbreviated as THF) (PVC and CR both dissolve well).
Table 2 shows the results of measuring the insolubility after treatment at 40°C for 24 hours. In all cases, it is recognized that the insolubility rate is high and co-vulcanization is progressing.

[Table] Examples 12 to 23 NBR (manufactured by Nippon Zeon Co., Ltd., Nipole 1041), PVC
(Nippon Zeon Co., Ltd., Zeon 121) and as a stabilizer
RP101 tertiary butylcatechol (abbreviated as TBC) and 4,4′-thiobis(6-tertiary butyl-m-cresol (manufactured by Kawaguchi Kagaku Kogyo Co., Ltd., Antage RC) are each mixed in the following proportions as shown in Table 3. Blend as follows. Wrap NBR on a 2-inch roll, add fine powder PVC and stabilizer to it, and roll blend at 90°C for 15 minutes. The blend 10 thus obtained
The ingredients listed in Table 3 are further added to the mixture, and the mixture is further roll blended to form a blend sheet. This sheet was pressed at 170℃ for 30 minutes to a thickness of 0.1
Co-vulcanizate sheets of mm and 1 mm are obtained. The THF insolubility and swelling degree of a 0.1 mm sheet and the physical properties of a 1 mm sheet were measured and the results are shown in Table 4.

【table】

【table】

[Table] Examples 24 to 27 and Comparative Examples 1 to 2 Blend sheets prepared in the same manner as Examples 12 to 23 with the blending ratios listed in Table 5 were pressed at 170°C for 45 minutes to form a 1 mm thick sheet. Vulcanizate sheets were obtained, and the results of measuring the permanent set and oil resistance of these samples were reported in the fifth section.
Shown in the table.

[Table] Examples 28-31 NBR compounds are prepared by blending the formulations of Group A in Table 6 at 80-100°C for 30 minutes. On the other hand, in the case of PVC, the composition of Group B in Table 6 is 170
℃ for 10 minutes, and others at 80℃ for 30 minutes to make a chlorine-containing rubber compound. Furthermore, both were heated to 170℃.
Blend for 20 minutes at 100°C (for PVC) or 30 minutes at 100°C to obtain a co-blend. This was heated to 170℃ for 40 minutes.
A co-vulcanizate was obtained by heating for a minute. Table 6 shows the results of measuring the insolubility of co-vulcanizate samples after treating them at 40° C. for 48 hours in THF (NBR and halogen-containing polymers dissolve easily).

【table】

【table】

[Table] Rubber content in vulcanizate

Claims (1)

[Scope of Claims] 1 A mixture of polyvinyl chloride, chlorosulfonated polyethylene, or fluororubber and diene rubber is represented by (1) the following formula: [However, R is SR′ or NR′R″, R′ and
R'' are the same or different hydrogen atom, alkyl group (1 to 4 carbon atoms), or phenyl group; M is hydrogen atom, Ma, K, Li, 1/2Ca, 1/2Mg, 1/2Ba, 1/
2-substituted-4,6-dithiol-s represented by 2Sr, 1/2Zn, 1/2Ni or 1/2Cu]
-At least one triazine derivative and (2) NH ₂ OCN=NCONH ₂ , as well as -N=N-, in a molecule selected from the group consisting of
A method for co-vulcanizing a halogen-containing polymer and a diene rubber, the method comprising heating in the presence of at least one compound containing an -S- group or an -N-S- group.