JPS6142733B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composition for co-crosslinking a halogen-containing polymer and a diene rubber. 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, since halogen-containing polymers and diene rubbers have completely contradictory reactivities during vulcanization and their reactive parts are different, it is impossible to vulcanize a mixture of these polymers in the same vulcanization system and under the same conditions. It was difficult.
That is, the halogen-containing polymer has C-X (X
represents a halogen) is the reactive moiety and is vulcanized by a nucleophilic substitution reaction of the vulcanizing agent, but in diene rubber, C=C in the molecule is the reactive moiety and is vulcanized by the radical addition reaction of the vulcanizing agent. Vulcanized by 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 bifunctionality in which one functional part undergoes a nucleophilic substitution reaction with C-X, and the other functional part undergoes radical addition to C=C. vulcanizing agents are desirable, but no single compound has been found to achieve this purpose. As a result of intensive research, the present inventors found that (1) at least one of the following 2-substituted-4,6-dithiol-s-triazines and (2) -S-S-
It was discovered that a mixture of a halogen-containing polymer and a diene rubber could be simultaneously vulcanized by coexisting at least one compound containing a -S-N= group or a -S-N= group, and a patent application was filed (Japanese Patent Application No.
118083). After that, as a result of intensive research by the present inventors, it was found that there were many limitations in adjusting the co-crosslinking rate using only the first group of compounds and the second group of compounds, and the reaction temperature required for co-crosslinking was too high for practical purposes. It was found that improvements were needed. It is an object of the present invention to meet such demands. As a result of intensive research, the present inventors further determined that polyethylene glycol and/or polypropylene glycol was added by 0.3 to 7% by weight to the mixture of (A) halogen-containing polymer and (B) diene rubber (hereinafter referred to as the main mixture). The co-crosslinking rate can be adjusted by adding 20% of the co-crosslinking temperature.
It was found that the temperature could be lowered, leading to the present invention. That is, the present invention includes at least one of (1) 2-substituted-4,6-dithiol-s-triazine derivatives (compounds of the first group) in a mixture consisting of (A) a halogen-containing polymer and (B) a diene rubber.
0.5 to 5 parts by weight of seeds (2) At least one compound containing a -S-S- group or -S-N= group in the molecule (compounds of the second group)
Species 1 to 7 parts by weight (3) Polyethylene glycol with a weight average molecular weight of 150 or more and/or a weight average molecular weight of 150 or more
Provided is a composition for co-crosslinking a halogen-containing polymer and a diene rubber, which contains a compounding agent containing 0.3 to 7 parts by weight of polypropylene glycol of 195 or higher as an essential component. (3) Polyethylene glycol in the present invention is
Polypropylene glycol means one whose weight average molecular weight is 150 or more (trimer or more), and polypropylene glycol is
Indicates that the weight average molecular weight is 195 or more (trimer or more). If the weight average molecular weight is too small, it is undesirable because it tends to bleed onto the rubber product, impairing adhesion, or causing premature vulcanization (scorch) before crosslinking of the rubber compound. It is presumed that the glycol used in the present invention increases the nucleophilic reactivity of the first group of compounds and, at the same time, increases the radical reactivity of the second group of compounds.
That is, although the reason for the fact that the physical properties of the crosslinked composition of the present invention are significantly improved is not clear in detail,
It is assumed that glycol increases radical reactivity as well as nucleophilic reactivity. The amount of glycol added to the main mixture used in the present invention is 0.3 to 7 parts by weight. If the amount added is less than 0.3 parts by weight, the effect will be small, and if it is more than 7 parts by weight, the co-crosslinking rate will reach a ceiling and industrial defects such as bleeding will increase. The halogen-containing polymer to which the present invention can be applied is a polymer containing a C-X bond in the molecule, and typical examples thereof include polyvinyl chloride and its vinyl acetate, ethylene, propylene, butadiene, styrene, etc. (usually 40 mol% or less). (preferably 20 mol% or less), epichlorohydrin polymers and copolymers thereof, fluororubbers, and the like. Among these, polyvinyl chloride is particularly preferred. Diene rubbers are rubbers made of polymers and copolymers containing units with a diene structure, such as polybutadiene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene rubber, chloroprene rubber, isoprene rubber, propylene rubber, etc. -Butadiene rubber can be cited as a representative example. The compound of the first group (1) used in the present invention, ie, the 2-substituted-4,6-dithiol-s-triazine derivative, is a compound represented by the following formula. [However, R is OR′, SR′, NR′R″,
NHC ₆ H ₄ NHC ₆ H ₅ , N (i・C ₃ H ₇ )
C ₆ H ₄ NHC ₆ H ₅ , NHC ₆ H ₂ (tC ₄ H ₉ )OH, NHC ₆ H _{2
( CH3} )( _tC4H9 )OH, _{SC6H2 ( tC4H9} ) _OH ,
NHC ₆ H ₄ N (C ₆ H ₅ ) ₂ , OC ₆ H ₃ (OH) COC ₆ H ₅ ;
R' and R'' are the same or different and may be a hydrogen atom, an alkyl group (1 to 18 carbon atoms), an alkenyl group (1 to 18 carbon atoms), a phenyl group, a phenylalkyl group, an alkylphenyl group, or a naphthyl group. , cycloalkyl group or morpholino group; M is a hydrogen atom,
Na, K, Li, 1/2Ca, 1/2Mg, 1/2Ba, 1/2Sr,
1/2Zn, 1/2Ni or 1/2Cu] The amount of the triazinethiol derivative added is not particularly limited, but the mixture (main mixture) of halogen-containing polymer and diene rubber is 100 parts (by weight; the same applies hereinafter). Usually 0.1 to 10 parts, preferably 0.5
Addition amounts of ~5 parts are sufficiently effective. Even if the amount added is further increased, the price will increase and it may cause bleeding, poor adhesion, etc. (2) Second group of compounds used in the present invention, that is, compounds having a -S-S- group or a -S-N= group in the molecule, include: etc. are listed as representative examples. At least one of these compounds is usually added in an amount of 1 to 7 parts per 100 parts of the mixture (main mixture) of the halogen-containing polymer and diene rubber. If the amount added is less than 1 part, the degree of crosslinking will be practically low, and if it is less than 7 parts, blooming may occur, which is not preferable. In the present invention, the mixing ratio of (A) halogen-containing polymer and (B) diene rubber is not particularly limited;
They are usually mixed in a weight ratio of 1:9 to 9:1. The above-mentioned (1) 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; The crosslinking reaction does not proceed. In the present invention, various additives generally used for halogen-containing polymers and diene rubbers can be added together with the compounds (1), (2), and (3) above. In particular, it is preferable to add 0.2 to 10 parts of metal oxides such as MgO, CaO, ZnO, BaO, and SrO. In addition, metal soaps, organotin stabilizers, epoxy stabilizers, which are usually added to halogen-containing polymers,
Phosphate stabilizer, plasticizer, CaCO ₃ ,
Fillers such as TiO ₂ carbon; stearic acid amine anti-aging agents, phenolic anti-aging agents, processing aids, etc. that are added to diene rubbers can be blended as appropriate. Example 1, Comparative Example 1 Styrene-butadiene rubber (SBR, JSR1502,
A total of 100 parts of 50 parts of polyvinyl chloride (Vinicron 3000M, manufactured by Mitsui Toatsu Chemical Co., Ltd.) and 2 parts of stabilizer Yellow 675C (manufactured by Nissan Yellow Co., Ltd.) were rolled on a roll at 160°C for 10 minutes. mixed with. Add 2-dibutylamino-4,6 to this mixture.
- 4 parts of dithiol-s-triazine (hereinafter referred to as "DB"), 1 part of N-cyclohexyl-2-benzothiazylsulfenamide (hereinafter referred to as "promoter CZ"), tetramethylthiuram disulfide (hereinafter referred to as "promoter CZ"), 2 parts of ZnO, 2 parts of ZnO,
5 parts MgO, 1 part stearic acid, Antige W
-300 (manufactured by Kawaguchi Kagaku Kogyo Co., Ltd.) and polyethylene glycol (molecular weight: about 300) were varied as shown in Table 1, mixed for 10 minutes on a roll at about 80°C, and molded. After standing for one day, press vulcanization was performed at 160° C. for 20 minutes to obtain a vulcanized product. Approximately 1 g of crushed vulcanized sample was added to cyclohexanone.
The cyclohexanone solution was poured into a large amount of methanol after being kept at 50°C for 24 hours. The weight percent of the precipitated polymer compound is defined as SBR.
The values are calculated for the total amount of PVC and shown in Table 1. Cyclohexanone is a solvent for SBR and PVC and will elute if not crosslinked.

[Table] Example 2, Comparative Example 2 Chloroprene rubber (CR; W-type, manufactured by Showa Neoprene Co., Ltd.) and polyvinyl chloride (PVC;
Add 3 parts of stabilizer (RP-101, manufactured by Tokyo Fine Chemical Co., Ltd.) to a total of 100 parts of Vinicron 3000M (manufactured by Mitsui Toatsu Chemical Co., Ltd.) at the mixing ratio shown in Table 2, and heat the mixture at 160°C.
Roll blend for 10 minutes. Table 2
The listed ingredients, 1 part of polyethylene glycol (molecular weight approximately 500), 1 part of stearic acid, 5 parts of MgO, Antige W-300 (manufactured by Kawaguchi Chemical Industry Co., Ltd.)
2 parts of ZnO and 2 parts of ZnO were mixed on a roll at about 60°C for 10 minutes, left for one day, and then press-vulcanized at 150°C for 20 minutes. The physical properties of the obtained vulcanizate were measured according to JIS K-6301, and the measurement results are shown in Table 2.

[Table] Example 3, Comparative Example 3 In order to understand the influence of the molecular weight of polyethylene glycol and/or polypropylene glycol on crosslinking, 70 parts of butadiene-acrylonitrile rubber (JSR N230S, manufactured by Japan Synthetic Rubber Co., Ltd.), polyvinyl chloride (Viniclon) 3000M (manufactured by Mitsui Toatsu Chemical Co., Ltd.) and 2 parts of a stabilizer were mixed on a roll at 160°C to 170°C for 10 minutes and left for one day. the mixture
For 102 parts, 3 parts MgO, 2 parts ZnO, 1 part stearic acid, and 50 parts SRF carbon black.
parts, 20 parts of dioctyl phthalate, 2 parts of N-cyclohexyl-2-benzothiazyl disulfide
1.8 parts, tetramethylthiuram disulfide
1 part, 0.2 parts of morpholine disulfide, 1 part of 2-dibutylamino-4,6-dithiol-s-triazine, and 2 parts of polypropylene glycol with different molecular weights were mixed, and the mixture was vulcanized at 150°C for 20 minutes. did. The physical properties of the vulcanizate were measured according to the method of JIS-K6301. As a result, there were no major differences except for compression set, and the 100% modulus was (50±5Kg/cm ² ).
300% modulus (120±10Kg/cm ² ), tensile strength (170±10Kg/cm ² ), elongation (450±50%),
The hardness (JIS A) was 70±2).

[Table] Table 3 shows the compression set at 120°C x 72°C. Although the reason for this change in compression set is unknown, it is presumed that unreacted crosslinking agent remains in the vulcanizate and causes a crosslinking reaction during the test.

Claims (1)

[Scope of Claims] 1. At least one of (1) 2-substituted-4,6-dithiol-s-triazine derivatives (compounds of the first group) is added to a mixture consisting of (A) a halogen-containing polymer and (B) a diene rubber. 1
0.5 to 5 parts by weight of seeds (2) At least one compound containing -S-S- group or -S-N= group in the molecule (compounds of the second group)
Species 1 to 7 parts by weight (3) Polyethylene glycol with a weight average molecular weight of 150 or more and/or a weight average molecular weight of 150 or more
A composition for co-crosslinking a halogen-containing polymer and a diene rubber, which contains a compounding agent containing 0.3 to 7 parts by weight of polypropylene glycol having a molecular weight of 195 or more as an essential component. 2. The composition according to claim 1, wherein (A) the halogen-containing polymer is polyvinyl chloride.