JPS5834836A - Vulcanizable composition of 1-acetoxy-1,3-butadiene (co) polymer - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which can be easily vulcanized to give a vulcanized product which is excellent in oil resistance and various characteristics, by blending sulfur or a sulfur-contg. org. compd. with a 1-acetoxy-1,3- butadiene (co) polymer. CONSTITUTION:Sulfur and/or a sulfur-contg. org. compd. are/is blended with l-acetoxy-1,3-butadiene (ABD) polymer or a copolymer of ABD and a monomer copolymerizable therewith. The monomer copolymerizable with ABD is used to improve mechanical properties, etc. of the polymer. Example thereof are alkyl (meth) acrylates, vinyl acetate and styrene. The amount of ABD to be copolymerized is pref. 0.5wt% or more. When the amount of ABD to be copolymerized is less than 0.5wt%, satisfactory effect can not be obtd. When it is 70wt% or more, a vulcanizable compsn. having excellent oil resistance can be obtd.

Description

Detailed Description of the Invention The present invention provides a vulcanized composition of a 1-acetoxy-1,3-butadiene polymer or a copolymer of 1-acetoxy-1,3-butadiene and a monomer copolymerizable therewith. relating to things.

1-acetoxy-1,3-butadiene (hereinafter referred to as 1-ABD)
Polymers or copolymers of (abbreviated as ) can be obtained by radical polymerization. However, this 1-7\BD
Little is known about the properties of these polymers or copolymers.

As a result of research on the properties of 1-AB'D polymers or copolymers, the present inventors found that 1-AB'D polymers or copolymers are easily oxidized by sulfur and/or sulfur-containing organic compounds. It has been found that the vulcanized composition has excellent oil resistance and excellent strength properties.

In addition, a copolymer whose main component is acrylic acid tetraster is known as acrylic rubber, and is generally a copolymer with excellent heat resistance, oil resistance, and elasticity. Generally, it is well known to copolymerize a monomer having an active group that serves as a crosslinking point before crosslinking. Conventionally, monomer components that serve as crosslinking points include 2-chloroethyl vinyl ether, vinyl chloroacetate, nalyl chloroacetate, vinylbenzyl chloride, and 5-chloroacetoxymethyl-2.
Norbornene-based monomers and epoxy-based monomers such as glycidyl ether, glycidyl acrylate, and glycidyl methacrylate are often used. These copolymers are generally crosslinked using amines, ammonium salts, metal soap-sulfur, etc. as crosslinking agents, but the crosslinking speed is slow, and in order to obtain optimal physical properties, extremely high Requires long heat treatment. In addition, when amines and ammonium salts are used among these crosslinking agents, there are hygiene problems such as the generation of foul-smelling gas during kneading and crosslinking, and the resulting crosslinked composition is also not suitable for pharmaceutical or food use. It has the disadvantage that it cannot be used for such purposes. Furthermore, when a nitrogen-based compound is used as a crosslinking monomer, it has the disadvantage that it corrodes the mold during crosslinking and corrodes the metal in contact with the resulting crosslinked composition.

In order to improve these shortcomings, dicyclosundadiene, methylcyclocontadiene, ethylidene norbornene, vinylidene norbornene, butadiene, imprene,
Copolymerization of allyl acrylate, annulate, etc. with acrylic acid ester as a crosslinking monomer is already known, but depending on the monomer, it was difficult to copolymerize, and crosslinking was extremely slow. However, the physical properties after crosslinking were far from practical, and there were also 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-A and BD can be vulcanized with sulfur in an extremely short time in a copolymer containing acrylic acid ester as a main component, and has a vulcanization composition. The present invention is based on the above findings, and the present invention is based on the above findings.
1-ABD which has extremely excellent oil resistance and is made by blending sulfur and/or a sulfur-containing organic compound with a polymer of ABD or a copolymer of 1-ABD and a monomer copolymerizable therewith. The present invention provides a vulcanized composition of a polymer or copolymer (hereinafter abbreviated as (co)polymer).

1-AB' which is a monomer of the polymer used in the present invention
D, which acetoxylates butadiene in the presence of a noble metal catalyst such as palladium, is obtained by heating crotonaldehyde in the presence of acetic anhydride and an alkali metal acetate.

1-4BD 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 arbitrarily mixed. It may be a 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 those used to improve the mechanical properties of the (co)polymer, such as dialkyl acrylate, alkyl methacrylate, acrylonitrile, methacrylatetrile, acetic acid. Examples include, but are not limited to, ethylenically unsaturated compounds such as vinyl, styrene, acrylamide, and vinylidene chloride, and diene compounds such as butadiene and isoprene. , it doesn't matter what you use. Further, two or more types of monomers may be used in combination.

The amount of 1-ABDO copolymerized 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 995% by weight. If the amount of 1-ABDO copolymerized is less than 0.05% by weight, the effect of copolymerizing 1-ABD cannot be sufficiently exhibited.
When the copolymerization amount of BD is 70% by weight or more, a vulcanized composition exhibiting particularly excellent oil resistance can be obtained.In addition, a vulcanized composition containing an acrylic ester as a main component with excellent heat resistance, oil resistance, and vulcanizability can be obtained. The copolymerization amount of monomers to obtain a copolymer is preferably 0.5 to 70% by weight of 1-'ABD, 60 to 995% by weight of acrylic acid ester, and monomers copolymerizable with these. It is 0 to 30% by weight. In this case, the acrylic acid ester is an alkyl acrylate in which the alkyl group has 1 to 8 carbon atoms, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, etc. Particularly preferred are alkyl acrylates in which the alkyl group has 2 to 4 carbon atoms, such as ethyl acrylate, propyl acrylate, butyl acrylate, and the like.

The (co)polymer used in the present invention is 1-ABD or 1-
It is easily produced by polymerization methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization using ABD and a monomer copolymerizable therewith with a commonly used radical polymerization initiator. The polymerization can be carried out at a temperature of -10 to -100°C, preferably 0 to 80°C, by batch polymerization or continuous polymerization.

The vulcanized composition of the present invention is obtained by blending the above polymer with sulfur and/or a sulfur-containing organic compound as a vulcanization system and vulcanizing it. It is a vulcanized composition that has a similar vulcanization rate, excellent oil resistance, and excellent properties.

Examples of sulfur-containing organic compounds used in vulcanization include sulfur-containing vulcanizing agents and vulcanization accelerators commonly used in rubber vulcanization, such as 2-mercaptobenzothiazole and 2-mercaptobenzothiazole. - zinc salt of mercaptobenzothiazole,
Thiazole compounds such as dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazylsulfenamide, N,N-dicyclohexyl-2-benzothiazylsulfenamide, N-oxyethylene di-2-benz 1-thiadylsulfenamide and other sulfenamide compounds, thiocarbinide, di-orthotolylthiourea, 2-mercaptoimidazo-1-dibutylthiourea,
Thiourea compounds such as dimethylethylthiourea, thiuram compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, zinc diethyldithiocarbamate , zinc dimethyldithiocarbamate, silver dimethyldithiocarbamate,
Dithiocarbamate compounds such as zinc ethylphenyldithiocarbamate, 2-dimethylamino-4,6-dimercapto-S-)riazine, 2-diethylamine-4
, 6-dimercapto-8-) riazine, 2-butylamino-4,6-dimercapto-S-triazine, 2-benzylamino, -4,6-dimercapto-S-triazine, 2,4.6-) dimercapto-S - Triazine compounds such as triazine, other morpholine disulfides,
Examples include 4,4'-dithiomorpholine, and these can be used alone or in combination of two or more. The amount of sulfur and/or sulfur-containing refrigeration compound used is preferably 0.1 to 10 parts by weight as a sulfur content, particularly preferably 0.1 to 10 parts by weight, based on 100 N parts of the (co)polymer used in the present invention. .2 to 5 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 also contain other types of polymers or copolymers, scorch inhibitors, activators, anti-aging agents, plasticizers, peptization accelerators, and adhesives commonly used as compounding agents for rubber. Additives, softeners, reinforcing agents, foaming agents, lubricants, colorants, fillers, etc. may be added and blended as necessary. Also, metal compounds, especially Zn, Cd, Fe, 5
Oxides, hydroxides, carbonates, and organic carboxylates such as nSCu, Sr, Ca, Pb, B'a, and Mg are effective in accelerating the vulcanization rate, and among these, zinc oxide, - Lead oxide, red lead, lead carbonate, zinc stearate, magnesium oxide are effective;
It is preferable that 1 to 5 parts by weight are blended. 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 backings, foil seals, valve seats, and the like.

Next, the present invention will be explained in detail with reference to Examples.

Examples 1 to 5 In a glass pressure-resistant bottle with a capacity of 0 o cc, 100 y of the monomer shown in Table 1, 6 f of sodium dodecylbenzenesulfonate, 2009 ml of water, 0.1 ml of sodium ethylenediaminetetraacetate, and sulfuric acid Ferrous o, 1y L Sodium formaldehyde sulfoxylate 01y, paramenthane hydroperoxide '1. Prepare OF and 10℃
Polymerization was carried out for 15 hours. After that, 1.0y of N,N-diethylhydroxylamine was added to stop the emulsion. An emulsion without any coagulum was obtained. This emulsion was dropped into 3t of methanol with stirring to precipitate the polymer. This (co)polymer was thoroughly washed with methanol and dried under vacuum at 50°C. The polymerization results are shown in Table 1. Table 1 The obtained (co)polymer was heated at 50°C according to the formulation shown in Table 2.
The mixture was kneaded with a roll to obtain a blend. Then at 160℃ 2
Press vulcanization was carried out for 0 minutes at 50° C. In all cases, elastic vulcanized compositions were obtained.

Table 2 Example 6 The vulcanized compositions obtained in Examples 1 to 6 were tested according to JIS K-63.
15 in a toluene/in-octane mixed solution according to 01
After immersion at 0°C for 70 hours, the volume increase rate was measured.

The results are shown in Figure 1.

From this result, the (co)polymer vulcanized composition of 1-ABD is
It can be seen that the composition has excellent oil resistance.

Examples 7 to 10 The polymer of Example 1 was heated at 160°C according to the formulation shown in Table 3.
The vulcanization behavior was measured using a curelastometer (manufactured by Japan Synthetic Rubber).
The results of the investigation are shown in Figure 2 @Examples 11 to 18 and Comparative Example 1 100y of the monomer shown in Table 4, 6y of sodium dodecylbenzenesulfonate, and water were placed in a glass pressure-resistant bottle with a capacity of 500CC under nitrogen. 2oay.

Sodium ethylenediaminetetraacetate D, 1f, 1st sulfuric acid
Iron 01, sodium formaldehyde sulfoxylate 0.13', paramenthane hydroperoxide 1.0
y was charged and polymerized at 10°C for 15 hours.

Thereafter, 1.0 g of N,N-diethylhydroxylamine was added to terminate the polymerization.

An emulsion with almost no coagulum was obtained, and this emulsion was dropped into 3 tons of methanol under stirring to precipitate a copolymer.The copolymer was thoroughly washed with methanol and then placed under vacuum at 50°C. Dry.

The results are shown in Table 4.

Table 4 The obtained copolymer was kneaded with a roll at 50°C according to the formulation shown in Table 5 to obtain a blend. Then, press vulcanization was carried out at 160° C. for 20 minutes. In each case, 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 J-Tech 5K-6301.

The results are shown in Table 6.

Table 6 Example 19 The vulcanized compositions of Examples 11 to 16 were tested according to JIS K-6301.
Accordingly, add toluene/isooctane mixed solution to 150℃.
The volume increase rate after 70 hours of immersion was measured and the results are shown in FIG.

The results show that the greater the amount of 1-AB'D copolymerized, the greater the improvement in the oil resistance of the vulcanized composition.

Examples 20 to 23 The copolymer of Example 12 was mixed according to the formulation shown in Table 7, 160
Figure 4 shows the results of examining the vulcanization behavior at °C using a curelastometer (manufactured by Japan Synthetic Rubber ■).

Examples 24-25 Comparative Example 2 100j' of the monomer shown in Table 8 and 2.59. Water 2ooP, +J potassium phosphate 0
．． 39, 6th class dodecyl mercaptan 0.3F, ferrous sulfate 0.003. f, sodium ethylenediaminetetraacetate 0.0065', sodium formaldehyde sulfoxylate a, oly, and halamenthane hydroperoxide 0.01y were charged and polymerized at 30°C for 6 hours. Thereafter, N,N-diethylhydroxylamine 005y was added to stop the reaction. 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.

The obtained copolymer was kneaded in a roll at 100°C according to the formulation shown in Table 9 to obtain a blend. Then, press vulcanization was carried out at 155°C for 15 minutes.
Table 10 shows the volume increase rate after immersion in No. 3 oil according to No. 12 at 120°C for 7 hours.

Table 10 Example 26 In a glass pressure bottle with a capacity of 500 CC, add 60 g of butadiene under nitrogen, 301.1-ABDloy of styrene, and 2 g of water.
00ri, resin acid stone Ken 5y, ferrous sulfate 0.02jE,
Alkylnaphthalene sulfonic acid: /-yo, 15y, ethylenediaminetetraacetate 01F, sodium dimethyl sulfoxylate 0.11, and 6th class dodecyl mercaptan 0.3y were charged and polymerized at 5°C, and a polymerization terminator was added at a conversion rate of 60%. Added. This emulsion was coagulated with methanol and then dried under vacuum at 50°C to obtain a true polymer containing 64% by weight of butadiene, 24% by weight of styrene, and 12% by weight of 1-ABD.

The obtained copolymer was kneaded in a parry mixer and a roll according to the formulation shown in Table 11, and the vulcanized composition 3.
The measured tensile stress and tensile strength were 142 Wcm2 and 310 Wcm2, respectively.

Table 11 (Vulcanization conditions: 145°C, 40 minutes)

[Brief explanation of the drawing]

Figures 1 and 3 are graphs of the volume increase rate of the vulcanized composition of the present invention, and Figures 2 and 4 are graphs showing the vulcanization behavior of the homopolymer (of Examples of the present invention). Yes. Patent Applicant: Japan Synthetic Rubber Co., Ltd. Agent, Patent Attorney Akira Ito

Claims (1)

[Claims] Polymer of 1-acetoxy-1,3-butadiene or 1
-1-acetoxy-1,3-butadiene polymer obtained by blending sulfur and/or a sulfur-containing organic compound with a copolymer of acetoxy-1,3-butadiene and a monomer copolymerizable with it. vulcanized composition.