JPH0134261B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vulcanized composition of a 1-acetoxy-1,3-butadiene polymer or a copolymer of 1-acetoxy-1,3-butadiene and an amount of a monomer copolymerizable therewith. 1-acetoxy-1,3-butadiene (hereinafter referred to as 1
-ABD) polymers or copolymers can be obtained by radical polymerization. However, little is known about the properties of this 1-ABD polymer or copolymer. As a result of research on the properties of 1-ABD polymers or copolymers, the present inventors found that 1-ABD polymers or copolymers are easily vulcanized by sulfur and/or sulfur-containing organic compounds, and that 1-ABD polymers or copolymers are easily vulcanized by sulfur and/or sulfur-containing organic compounds. It has been found that the vulcanized composition has excellent oil resistance and various excellent properties. In addition, copolymers containing acrylic acid ester as the main component are known as acrylic rubbers, and are generally heat-resistant, oil-resistant, and highly elastic copolymers, but they contain double bonds in the main chain of the copolymer molecules. Generally, it is well known to copolymerize monomers with active groups that serve as crosslinking points for crosslinking. Conventionally, monomer components serving as these crosslinking points include 2-chloroethyl vinyl ether, vinyl chloroacetate, allyl chloroacetate,
Halogen monomers such as vinylbenzyl chloride and 5-chloroacetoxymethyl-2-norbornene, and epoxy monomers such as allyl glycidyl ether, glycidyl acrylate, and glycidyl methacrylate are often used. These copolymers are generally crosslinked using amines, ammonium salts, metal sulfur, etc. as a crosslinking agent, but the crosslinking speed is slow, and in order to obtain optimal physical properties, extremely high temperatures are required after crosslinking. Requires long heat treatment. Furthermore, when amines, ammonium salts, etc. are used among these crosslinking agents, there are hygiene problems such as generation of foul-smelling gas during kneading and crosslinking, and the resulting crosslinked compositions are also used for pharmaceutical and food purposes. It has the disadvantage that it cannot be used for other purposes.
Furthermore, when a halogen compound is used as a crosslinking monomer, it has the disadvantage that it corrodes the mold during crosslinking or corrodes the metal in contact with the resulting crosslinked composition. In order to improve these drawbacks, dicyclopendadiene, methylcyclopentadiene, ethylidene norbornene, vinylidene norbornene, butadiene, isoprene, allyl acrylate, 2-
Copolymerization of butenyl acrylate, triallyl isocyanurate, etc. with acrylic acid esters as crosslinking monomers is already known, but some monomers are difficult to copolymerize.
In addition to the fact that crosslinking was extremely slow and the physical properties after crosslinking were far from practical, they also had drawbacks such as deterioration in oil resistance, which is a characteristic of copolymers whose main component is acrylic ester. The present inventors have found that a copolymer containing 1-ABD as a main component of such an acrylic ester can be sulfur-cured in an extremely short time, and that the vulcanization composition is It has also been found that it has various excellent properties such as further improved oil resistance. The present invention is based on the above findings, and the present invention relates to a polymer of 1-ABD or a polymer of 1-ABD polymerized at -10 to 60°C in the presence of a radical polymerization initiator, or a polymer of 1-ABD and the like. A 1-ABD polymer having extremely excellent oil resistance, which is made by blending sulfur and/or a sulfur-containing organic compound with a copolymer of at least one conjugated diene and/or ethylenically unsaturated compound copolymerizable with The present invention provides a vulcanized composition of a polymer or copolymer (hereinafter abbreviated as (co)polymer). 1-ABD, the monomer of the (co)polymer used in the present invention, acetoxylates butadiene in the presence of a noble metal catalyst such as palladium, while crotonaldehyde is heated in the presence of acetic anhydride and alkali metal acetate. obtained by doing. 1-ABD obtained by these reactions is a mixture of cis and trans forms, but the monomers of the (co)polymer used in the present invention may be cis or trans forms alone, or they may be optionally mixed. It may be a mixed mixture. Further, it may contain impurities to the extent that it does not cause any inconvenience. The monomers copolymerizable with 1-ABD used in the present invention are used to improve the mechanical properties of the (co)polymer, and include alkyl acrylate, alkyl methacrylate, acrylonitrile, methacrylonitrile, Examples include ethylenically unsaturated compounds such as vinyl acetate, styrene, acrylamide, and vinylidene chloride, and conjugated dienes such as butadiene and isoprene.
A species or two or more species may be used. The copolymerized amount of 1-ABD in the (co)polymer used in the present invention is preferably 0.5% by weight or more. Therefore, the preferred copolymerization amount of the monomer copolymerizable with 1-ABD is 0 to 99.5% by weight. If the copolymerization amount of 1-ABD is less than 0.5% by weight, the effect of copolymerizing 1-ABD cannot be sufficiently exhibited. Furthermore, when the copolymerization amount of 1-ABD is 70% by weight or more, a vulcanized composition exhibiting particularly excellent oil resistance can be obtained. Furthermore, the amount of copolymerized monomers is preferably 1-
ABD0.5~70% by weight, acrylic ester 30~
99.5% by weight and 0 monomers copolymerizable with these
~30% by weight. The acrylic esters in this case are alkyl acrylates in which the alkyl group has 1 to 8 carbon atoms, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate,
Examples include hexyl acrylate, cyclohexyl acrylate, octyl acrylate, etc. Particularly preferred are alkyl acrylates in which the alkyl group has 2 to 4 carbon atoms, and examples include ethyl acrylate, propyl acrylate, butyl acrylate, etc. Can be done. The (co)polymer used in the present invention is emulsion polymerization, suspension polymerization, solution polymerization of 1-ABD or 1-ABD and a monomer copolymerizable with it using a commonly used radical polymerization initiator. It is easily produced by polymerization methods such as bulk polymerization. The polymerization can be carried out at a temperature of -10 to 60°C, preferably 0 to 60°C, by batch polymerization or continuous polymerization. The vulcanized composition of the present invention is obtained by blending sulfur and/or a sulfur-containing organic compound as a vulcanization system with the above-mentioned (co)polymer and vulcanizing it. It is a vulcanized composition that has a vulcanization rate comparable to that of rubber, excellent oil resistance, and excellent various properties. The sulfur-containing organic compound used for vulcanization is a compound containing sulfur among the vulcanizing agents and vulcanization accelerators normally used for vulcanizing rubber, such as 2
- Thiazole compounds such as mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole, dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazylsulfenamide, N,N-dicyclohexyl-2-benzothiazyl Sulfenamide, N-oxyethylene-2
-Sulfenamide compounds such as benzothiazylsulfenamide, thiocarbanides, diorthotolylthiourea, 2-mercaptoimidazoline dibutylthiourea, thiourea compounds such as dimethylethylthiourea, tetramethylthiuram monosulfide, tetramethylthiuram Disulfide, thiuram compounds such as tetraethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, ethylph Dithiocarbamate compounds such as zinc enyldithiocarbamate, 2-dimethylamino-4,6-dimercapto-s-triazine, 2-diethylamino-4,6-dimercapto-s-triazine, 2-butylamino-4,
Triazine compounds such as 6-dimercapto-s-triazine, 2-benzylamino-4,6-dimercapto-s-triazine, 2,4,6-trimercapto-s-triazine, other morpholine disulfides, 4,4 '-dithiomorpholine and the like can be used alone or in combination of two or more. The amount of sulfur and/or sulfur-containing organic compound used is preferably 0.1 to 10 parts by weight, particularly preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the (co)polymer used in the present invention. Parts by weight, more preferably 0.5 to 3 parts by weight. If the amount used is less than 0.1 part by weight, the vulcanization rate will be extremely slow and the vulcanized composition will not have sufficiently satisfactory physical properties. Moreover, if it exceeds 10 parts by weight, heat resistance becomes extremely poor. In addition to sulfur, the vulcanized composition of the present invention may contain other types of polymers or copolymers, scorch inhibitors, activators, anti-aging agents, plasticizers, smelting accelerators, etc., which are generally used as compounding agents for rubber. Tackifiers, softeners, reinforcing agents, foaming agents, lubricants, colorants, fillers, etc. may be added and blended as necessary. Also metal compounds, especially Zn, Cd, Fe, Sn, Cu, Sr,
Oxides, hydroxides, carbonates, and organic carboxylates such as Ca, Pb, Ba, and Mg are effective in accelerating the vulcanization rate. Among these, zinc oxide, lead monoxide, red lead, and carbonate are particularly effective. Lead, zinc stearate, and magnesium oxide are effective, and are preferably blended in an amount of 1 to 5 parts by weight per 100 parts by weight of the (co)polymer. Note that the vulcanization conditions for the vulcanization composition of the present invention are not particularly limited, and normal vulcanization conditions can be used. The vulcanized composition thus obtained has excellent oil resistance and is useful in many fields requiring such performance. Such applications include a variety of rubber-like products such as gaskets, hoses, conveyor belt bagging, foil seals, valve seats, and the like. Next, the present invention will be explained in detail with reference to Examples. Examples 1 to 5 The first container was placed in a 500 c.c. glass pressure bottle under nitrogen.
100 g of the monomer shown in the table, 6 g of sodium dodecylbenzenesulfonate, 200 g of water, 0.1 g of sodium ethylenediaminetetraacetate, 0.1 g of ferrous sulfate, 0.1 g of sodium formaldehyde sulfoxylate,
Prepare 1.0g of paramenthane hydroperoxide
Polymerization was carried out at 10°C for 15 hours. Thereafter, 1.0 g of N,N-diethylhydroxylamine was added to stop the reaction. An emulsion free of any coagulum was obtained, and this emulsion was dropped into the methanol from step 3 under stirring to precipitate the (co)polymer. The (co)polymer was thoroughly washed with methanol and heated to 50°C. Dry under vacuum. The polymerization results are shown in Table 1. The number average molecular weights are 26,000 for Example 1, 57,000 for Example 2, 74,000 for Example 3, 50,000 for Example 4,
In Example 5, it was 80,000. Here, the number average molecular weight is measured by GPC after dissolving the polymer or copolymer in a suitable solvent such as acetone or tetrahydrofuran, and is determined by converting it from polystyrene as a standard sample of number average molecular weight.

[Table] The obtained (co)polymer was kneaded with a roll at 50°C according to the formulation shown in Table 2 to obtain a blend. Then
Press vulcanization was performed at 160°C for 20 minutes. All elastic vulcanized compositions were obtained at 50°C.

[Table] Example 6 The vulcanized compositions obtained in Examples 1 to 3 were tested according to JIS K-
Toluene/in-octane mixed solution according to 6301
The volume increase rate was measured after immersion at 150°C for 70 hours. The results are shown in Figure 1. This result shows that the 1-ABD (co)polymer vulcanized composition is a composition with excellent oil resistance. Examples 7 to 10 The polymer of Example 1 was mixed according to the formulation shown in Table 3.
Figure 2 shows the results of examining the vulcanization behavior at 160°C using a Cyulastometer (manufactured by Japan Synthetic Rubber Co., Ltd.).

[Table] Examples 11 to 18 and Comparative Example 1 A glass pressure bottle with a capacity of 500 c.c.
100 g of the monomer shown in the table, 6 g of sodium dodecylbenzenesulfonate, 200 g of water, 0.1 g of sodium ethylenediaminetetraacetate, 0.1 g of ferrous sulfate,
sodium formaldehyde sulfoxylate
0.1 g of p-menthane hydroperoxide and 1.0 g of para-menthane hydroperoxide were added, and polymerization was carried out at 10° C. for 15 hours. Then N,N-diethylhydroxylamine
1.0 g was added to stop the polymerization. An emulsion with almost no coagulates was obtained, and this emulsion was added dropwise to the methanol in Step 3 under stirring to precipitate the copolymer.The copolymer was thoroughly washed with methanol, and then the copolymer was washed thoroughly with methanol. Dry. The results are shown in Table 4.

[Table] The obtained copolymer was mixed according to the formulation shown in Table 5.
A blend was obtained by kneading with a roll at ℃. Then 160
Press vulcanization was performed at ℃ for 20 minutes. In all cases, elastic vulcanized compositions were obtained. Among these, the physical properties of the vulcanized compositions of Example 14 and Comparative Example 1 were measured according to JIS K-6301. The results are shown in Table 6.

【table】

【table】

[Table] Example 19 The vulcanized compositions of Examples 11 to 13 were added to a toluene/isooctane mixed solution at 150°C and 70°C according to JIS K-6301.
The volume increase rate after soaking for a period of time was measured and the results are shown in FIG. This result shows that the oil resistance of the vulcanized composition is greatly improved as the amount of copolymerized 1-ABD increases. Examples 20 to 23 The copolymer of Example 12 was mixed according to the formulation shown in Table 7.
Figure 4 shows the results of examining the vulcanization behavior at 160°C using a Cyulastometer (manufactured by Japan Synthetic Rubber Co., Ltd.).

【table】

[Table] Examples 24-25 Comparative Example 2 A glass pressure bottle with a capacity of 500 c.c.
100g of the monomer shown in the table, 2.5g of sodium alkylbenzenesulfonate, 200g of water, potassium phosphate
0.3 g of tertiary dodecyl mercaptan, 0.003 g of ferrous sulfate, 0.006 g of sodium ethylenediaminetetraacetate, 0.01 g of sodium formaldehyde sulfoxylate, and 0.01 g of paramenthane hydroperoxide, and polymerized at 30°C for 6 hours.
Then N,N-diethylhydroxylamine 0.05
I turned on g and stopped it. The polymerization conversion rate was approximately 80% in all cases. This emulsion was coagulated with a 1% calcium chloride solution and dried with hot air at 100°C. The polymerization results are shown in Table 8.

[Table] The obtained copolymer was mixed according to the formulation shown in Table 9.
A blend was obtained by kneading in a roll at 100°C. Then
Press vulcanization was performed at 155°C for 15 minutes.

[Table] Physical properties of the obtained vulcanized composition and JIS K6301-
Table 10 shows the volume increase rate after immersion in No. 3 oil according to No. 12 at 120°C for 7 hours.

[Table] Example 26 In a glass pressure-resistant bottle with a capacity of 500 c.c., 60 g of butadiene, 30 g of styrene, 10 g of 1-ABD, and water were added under nitrogen.
200g, resin acid soap 5g, ferrous sulfate 0.02g,
0.15 g of sodium alkylnaphthalene sulfonate, 0.1 g of ethylene diamine tetraacetate, 0.1 g of sodium dimethyl sulfoxylate, 0.1 g of cumene hydroperoxide, and 0.3 g of tertiary dodecyl mercaptan were charged and polymerized at 5°C with a conversion rate of 60.
% of polymerization terminator was added. This emulsion was coagulated with methanol and then dried under vacuum at 50°C, containing 64% by weight of butadiene, 24% by weight of styrene, and 1-
A copolymer containing 12% by weight of ABD was obtained. The obtained copolymer was kneaded using a Banbury mixer and rolls according to the formulation shown in Table 11, and the tensile stress and tensile strength at 300% of the vulcanized composition were measured to be 142 Kg/cm ² and 310 Kg/cm ² , respectively. It was hot.

【table】

【table】 [Brief explanation of drawings]

FIGS. 1 and 3 are graphs of the volume increase rate of the vulcanized composition of the present invention, and FIGS. 2 and 4 are graphs showing the vulcanization behavior of the (co)polymer of the example of the present invention. It is.

Claims (1)

[Claims] 1 A polymer of 1-acetoxy-1,3-butadiene or 1-acetoxy-1,3-butadiene polymerized at -10 to 60°C in the presence of a radical polymerization initiator and at least one species copolymerizable therewith. 1-acetoxy-1,3- made by blending sulfur and/or a sulfur-containing organic compound with a copolymer with a conjugated diene and/or an ethylenically unsaturated compound
Vulcanized composition of butadiene (co)polymer.