JPH08311249A - Chloroprene polymer composition and its production - Google Patents

Abstract

PURPOSE: To obtain a chloroprene polymer compsn. excellent in ozone resistance and tear strength and a process for producing the same. CONSTITUTION: The compsn. contains a chloroprene polymer and a copolymer of a carboxylated ethylenically unsatd. compd. and an α,β-unsatd. carboxylic ester. The process is characterized in that a chloroprene polymer latex is mixed with an emulsion of a copolymer of a carboxylated ethylenically unsatd. compd. and an α,β-unsaid. carboxylic ester.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a chloroprene polymer composition having excellent ozone resistance and tear strength.
And its manufacturing method.

[0002]

BACKGROUND OF THE INVENTION Chloroprene polymers have a good balance of physical properties such as general rubber physical properties, weather resistance, heat resistance, chemical resistance, etc., so that they can be used in a wide range of fields such as general industrial rubber products, automobile parts and adhesives. in use. However, in recent years, the environment in which rubber products are used has become severe,
It is becoming difficult to deal with conventional chloroprene polymers.

One of such required properties is ozone resistance, but for chloroprene polymers, a method of improving ozone resistance by adding an antioxidant is general and widely used. ing.

[0004]

However, the method of adding an antioxidant may cause problems such as burning of an unvulcanized product, bloom of the antioxidant, and reduction in tensile strength of the vulcanized product. Therefore, not only is it difficult to select the type and amount of the antiaging agent, but also the effect of improving ozone resistance is not sufficient.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to provide a chloroprene polymer composition having greatly improved ozone resistance and excellent tear strength, and a method for producing the same. It is a thing.

[0006]

That is, the present invention provides a chloroprene polymer containing a chloroprene polymer containing a copolymer of an ethylenically unsaturated compound having a carboxyl group and an α, β-unsaturated carboxylic acid ester. The present invention relates to a polymer composition, more specifically, the above α, β-
The present invention relates to a chloroprene polymer composition, wherein the unsaturated carboxylic acid ester is an acrylic acid ester, and the acrylic acid ester is n-butyl acrylate. In addition, the present invention is a chloroprene polymer composition characterized by mixing a chloroprene polymer latex and a copolymer emulsion of an ethylenically unsaturated compound having a carboxyl group and an α, β-unsaturated carboxylic acid ester. The present invention relates to a method for manufacturing a product.

The chloroprene polymer in the present invention is
It is a homopolymer of 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene), or a copolymer obtained by polymerizing chloroprene and at least one monomer copolymerizable with chloroprene.

Examples of the monomer copolymerizable with chloroprene in the present invention include 2,3-dichloro-1,3-
Examples thereof include butadiene, 1-chloro-1,3-butadiene, butadiene, isoprene, sulfur, styrene, acrylonitrile, acrylic acid and its esters, and methacrylic acid and its esters. If necessary, two or more may be used. Absent.

The chloroprene in the present invention may be polymerized alone or a monomer mixture containing chloroprene and a monomer copolymerizable therewith may be polymerized by any known method, but radical polymerization is carried out in an aqueous emulsion. The method is the most general and suitable.

The emulsifier used in the aqueous emulsion polymerization is not particularly limited, and is an emulsifier generally used in the emulsion polymerization of chloroprene, for example, an anionic emulsifier such as a rosin acid salt, a fatty acid salt or an alkylbenzene sulfonate, or Nonionic emulsifiers such as alkyl polyethylene glycol and polyvinyl alcohol, and cationic emulsifiers such as quaternary ammonium salts can be used. However, anionic emulsifiers such as rosin acid salts and fatty acid salts are preferable.

The polymerization temperature in the present invention is not particularly limited, but is preferably in the range of 0 to 55 ° C. When the polymerization temperature is lower than 0 ° C, water coagulation becomes a problem, and when it is higher than 55 ° C, pressure equipment is required due to the vapor pressure of chloroprene.

The molecular weight of the chloroprene polymer is usually adjusted by using a chain transfer agent.
For example, generally known alkyl mercaptans such as dodecyl mercaptan, xanthogen disulfides such as diethylxanthogen disulfide, and halogenated hydrocarbons such as iodoform can be used.

The polymerization initiator may be an organic or inorganic peroxide used in a usual chloroprene emulsion polymerization method, and examples thereof include benzoyl peroxide, potassium persulfate and ammonium persulfate. Further, a redox type radical initiator may be used for the purpose of controlling the reaction and completely carrying out the polymerization.

The copolymer of the ethylenically unsaturated compound having a carboxyl group and the α, β-unsaturated carboxylic acid ester in the present invention is an α, β-unsaturated carboxylic acid ester containing a carboxyl group in the polymer. Is a copolymer of.

Here, the α, β-unsaturated carboxylic acid ester is an ester obtained by reacting an α, β-unsaturated carboxylic acid with an alcohol. Examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and the like, with acrylic acid being particularly preferred.

Examples of alcohols include alkyl alcohols such as ethyl alcohol, butyl alcohol, dodecyl alcohol and octadecyl alcohol, alkenyl alcohols such as allyl alcohol, cyclic alcohols such as cyclopentyl alcohol and cyclohexyl alcohol, benzyl alcohol and phenethyl alcohol. Examples thereof include aralkyl alcohol, methoxyethyl alcohol, ethoxyethyl alcohol, glycidyl alcohol, dialkylaminoethyl alcohol, and the like. Among them, n-butyl alcohol and ethyl alcohol are preferable, and n-butyl alcohol is particularly preferable.

Examples of the ethylenically unsaturated compound having a carboxyl group include maleic acid half-esters such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, monomethyl maleate and monoethyl maleate,
Examples thereof include half esters such as fumaric acid, monomethyl fumarate, and monoethyl fumarate, itaconic acid, and 2-pentenoic acid, but are not limited thereto. Also, the amount of them used is not limited, but 0.1 to
It is preferable to use 10% by weight (based on the total amount of the ethylenically unsaturated compound having a carboxyl group and the α, β-unsaturated carboxylic acid esters).

The above-mentioned ethylenically unsaturated compound having a carboxyl group is known as a crosslinkable monomer of acrylic rubber, and when incorporated into acrylic rubber, the acrylic rubber can be crosslinked. Examples of such a crosslinkable monomer include alkylidene norbornene, alkenyl norbornene, dicyclopentadiene, diene compounds such as methylcyclopentadiene, glycidyl methacrylate, glycidyl acrylate, and ethylenically unsaturated compounds having an epoxy group such as allyl glycidyl ether, Vinylbenzyl chloride, vinylbenzyl bromide, 2-chloroethyl vinyl ether, vinyl chloroacetate, vinyl chloropropionate, allyl chloroacetate, allyl chloropropionate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, chloromethyl vinyl ketone , 2-chloroacetoxymethyl-5-norbornene and other ethylenically unsaturated compounds having an active halogen group are known. The can improve the tear strength in the light of the chloroprene polymer composition is limited to ethylenically unsaturated compound having a carboxyl group.

As the method for copolymerizing the ethylenically unsaturated compound having a carboxyl group of the present invention and the α, β-unsaturated carboxylic acid ester, any known method can be used, but the method by emulsion radical polymerization is generally used. Target.

As the emulsifier for emulsion polymerization of the α, β-unsaturated carboxylic acid ester, various emulsifiers can be used as in the polymerization of chloroprene.

The polymerization temperature of the α, β-unsaturated carboxylic acid ester is preferably selected in the range of 0 to 90 ° C., where water is coagulated below 0 ° C. and water is evaporated above 90 ° C. It becomes a problem.

In the chloroprene polymer composition of the present invention, it is essential that the chloroprene polymer contains a copolymer of an ethylenically unsaturated compound having a carboxyl group and an α, β-unsaturated carboxylic acid ester. . The content ratio is not particularly limited, in order to obtain a composition excellent in ozone resistance and tear strength without impairing various physical properties originally possessed by the chloroprene polymer, an ethylenically unsaturated compound having a carboxyl group. The content of the copolymer consisting of α and β-unsaturated carboxylic acid esters is 3 to 60.
The range of weight% is preferable, 5 to 40 weight% is more preferable, and 5 to 30 weight% is further preferable.

The chloroprene polymer composition of the present invention is a chloroprene polymer containing a copolymer of an ethylenically unsaturated compound having a carboxyl group and an α, β-unsaturated carboxylic acid ester. is there. The production method is not particularly limited, but if an example of the production method is given, the copolymer and the chloroprene polymer may be mixed, for example, a method of mixing a latex and an emulsion obtained by emulsion polymerization, a solid. A method of kneading the polymer-like polymers with an open roll, a kneader, a Banbury mixer, a single-screw or twin-screw extruder, a method of blending solutions dissolved in an organic solvent, and the like are used. Among them, the method of mixing the latex and emulsion obtained by emulsion polymerization is preferable because a uniform mixture can be easily obtained.

[0024]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples. In the following description, parts and% are based on weight.

Production of Chloroprene Polymer Latex (A1) 10 ml of water under a nitrogen stream in 3 liters of glass Kolben.
0 parts, 5 parts of disproportionated rosin acid as an emulsifier, 1.0 part of potassium hydroxide, and 0.8 parts of sodium salt of a formaldehyde naphthalene sulfonic acid condensate as a dispersant were charged, and after dissolution, 100 parts of chloroprene and with stirring. A mixture with 0.1 part of n-dodecyl mercaptan was added, and the mixture was polymerized at a polymerization temperature of 40 ° C. using potassium persulfate as a radical polymerization initiator. When the conversion of the monomer reached 65%, the tertiary conversion was performed. Butylcatechol and thiodiphenylamine were added to terminate the polymerization, and unreacted monomers were removed under reduced pressure to obtain a chloroprene polymer latex (A
1) was obtained.

Production of chloroprene polymer latex (A2) In the case of chloroprene polymer latex (A1) except that 95 parts of chloroprene and 5 parts of 2,3-dichloro-1,3-butadiene were used instead of 100 parts of chloroprene. Chloroprene-based polymer latex (A2)
I got

Production of Copolymer (B1) Consisting of α, β-Unsaturated Carboxylic Acid Ester In a 3 liter glass Kolben under a nitrogen stream, water 10
0 part, 5 parts of sodium dodecylbenzenesulfonate as an emulsifier were charged and dissolved, and then 100 parts of n-butyl acrylate as an α, β-unsaturated carboxylic acid ester, 1.5 parts of acrylic acid, 0.01 part of n-dodecyl mercaptan. Was added with stirring. When the polymerization temperature was 70 ° C. and potassium persulfate was used as the radical initiator, the conversion of the monomer was 98.
The n-butyl acrylate copolymer emulsion (B1) was obtained by carrying out the polymerization until the content became%.

Production of Copolymer (B2 to B4) Consisting of α, β-Unsaturated Carboxylic Acid Ester The amount of α, β-unsaturated carboxylic acid ester, crosslinkable monomer and chain transfer agent shown in Table 1 Copolymers (B2 to B4) composed of α, β-unsaturated carboxylic acid esters were obtained in the same manner as the polymer (B1).

Example 1 (A1) and (B1) obtained above were converted into (A1) 100
10 parts (B1) (in terms of solid content) was added to each part with stirring, and after sufficient stirring, a chloroprene polymer composition was obtained by a freeze-coagulation drying method.

Example 2, Comparative Examples 1 to 4 A chloroprene polymer was used in the same manner as in Example 1 except that the copolymer of the chloroprene polymer shown in Table 2 and the α, β-unsaturated carboxylic acid ester was used. A composition was obtained.

The above chloroprene polymer composition (raw rubber) was made into a vulcanized product with the formulation shown in Table 3 and a physical property test was conducted. JIS-K for hardness, tensile strength, elongation and tear strength
Tested according to 6301, and ozone resistance is JIS-
A dynamic ozone test (tensile method) was performed according to K6259. Table 4 shows the test results.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

INDUSTRIAL APPLICABILITY As described above, the chloroprene polymer composition of the present invention is excellent in ozone resistance and tear strength, and also retains the excellent mechanical properties originally possessed by the chloroprene polymer. . Therefore, it is suitable as a material for rubber boots, specifically, constant velocity joint boots, rack and pinion boots, ball joint boots, etc., particularly in the field of automobile industry. Further, it is also suitable as a rubber hose, specifically a brake hose, a power steering hose, a fuel hose, a radiator hose, an automobile hose such as a car air conditioner hose, and an external rubber material for various high pressure hoses. Furthermore, the chloroprene-based polymer composition of the present invention is a building gasket, specifically,
Air tight, spacer, glazing gasket,
It is also suitable as a material for joint gaskets, zipper gaskets, setting blocks, expansions, etc., and is also suitable for anti-vibration rubber and belts.

Claims (4)

[Claims] 1. A chloroprene-based polymer composition comprising a chloroprene polymer containing a copolymer of an ethylenically unsaturated compound having a carboxyl group and an α, β-unsaturated carboxylic acid ester. 2. The chloroprene polymer composition according to claim 1, wherein the α, β-unsaturated carboxylic acid ester is an acrylic acid ester. 3. The chloroprene polymer composition according to claim 2, wherein the acrylic acid ester is n-butyl acrylate. 4. A chloroprene polymer latex, an ethylenically unsaturated compound having a carboxyl group, and α, β-
A method for producing a chloroprene-based polymer composition, which comprises mixing a copolymer emulsion with an unsaturated carboxylic acid ester.