WO2014188859A1 - Chloroprene rubber, manufacturing method therefor, and chloroprene rubber composition - Google Patents

Abstract

　Provided are a chloroprene rubber adjusted so that vulcanization speed is retarded without the use of a sulfenamide compound or other additive having vulcanization-retarding effect, a manufacturing method therefor, a chloroprene rubber composition, and a manufacturing method therefor. A chloroprene rubber containing: 0.0005 to 0.1 mass% of elaidic acid and 0.0005 to 0.1 mass% of oleic acid in 100 mass% of chloroprene rubber having a chloroprene homopolymer or a copolymer of chloroprene and another monomer. This chloroprene rubber is obtained by emulsion polymerization of chloroprene alone or chloroprene and another monomer in the presence of an emulsifier containing 0.01 to 0.2 mass% of elaidic acid and 0.01 to 0.2 mass% of oleic acid.

Description

Chloroprene rubber, process for producing the same and chloroprene rubber composition

The present invention relates to a chloroprene rubber, a production method thereof, and a chloroprene rubber composition. More specifically, the present invention relates to a chloroprene rubber used as a material for industrial rubber products and automotive parts, a production method thereof, and a chloroprene rubber composition.

Chloroprene rubber is a synthetic rubber with excellent heat resistance, weather resistance, ozone resistance, and chemical resistance, and is used in a wide range of fields as a material for industrial rubber products, automotive parts, sponges, and the like.

A sponge made of chloroprene rubber is obtained by simultaneously foaming and vulcanizing chloroprene rubber. If the chloroprene rubber is vulcanized too quickly, the resulting foam cannot be sufficiently foamed, and if the vulcanization is too slow, the size of the bubbles will be uneven. For this reason, chloroprene rubber used as a sponge material is required to have a vulcanization rate adjusted by about 10 to 50% slower than chloroprene rubber used in general industrial rubber products.

As a method for adjusting the vulcanization speed of chloroprene rubber to be slow, a method of adding a specific sulfenamide-based compound having a vulcanization delay effect to chloroprene rubber is known (see Patent Document 1).

JP 2011-1528 A

By using the sulfenamide compound described in Patent Document 1, the vulcanization rate of chloroprene rubber can be reduced. However, depending on the type of sulfenamide compound used, foaming of chloroprene rubber may be inhibited.

An object of the present invention is to provide a chloroprene rubber having a slow vulcanization rate adjusted without using an additive having a vulcanization delay effect such as a sulfenamide compound, a production method thereof, and a chloroprene rubber composition. To do.

In the present invention, there is provided a chloroprene rubber containing 0.0005 to 0.1% by mass of elaidic acid and 0.0005 to 0.1% by mass of oleic acid in 100% by mass of chloroprene rubber having a chloroprene polymer. To do.

In the present invention, the chloroprene rubber or chloroprene rubber having a chloroprene polymer and containing no elaidic acid and oleic acid is 99.999 to 92% by mass, elaidic acid is 0.0005 to 4% by mass, and oleic acid is 0%. A chloroprene rubber composition comprising: .0005 to 4 mass%. The elaidic acid and elaidic acid contained in the chloroprene rubber composition may be derived from disproportionated tall oil soap.

In the present invention, chloroprene alone or chloroprene and other monomers are added in the presence of an emulsifier containing 0.01-0.2% by mass of elaidic acid and 0.01-0.2% by mass of oleic acid. There is also provided a method for producing chloroprene rubber by emulsion polymerization to obtain a chloroprene polymer.

In the present invention, “chloroprene rubber” refers to a polymer obtained by polymerizing a raw material monomer containing chloroprene as a main component and then washing and drying. In addition to the chloroprene homopolymer or the copolymer of chloroprene and other monomers, which is a product of the polymerization reaction, the chloroprene rubber includes an emulsifier, a dispersant, a catalyst, a catalyst activator added during polymerization, A chain transfer agent and a polymerization inhibitor may be contained.
“Chloroprene rubber composition” refers to the chloroprene rubber, vulcanizing agent, vulcanization accelerator, filler, reinforcing agent, softener, plasticizer, lubricant, anti-aging agent, stabilizer, silane coupling agent and receiving agent. It means what added additives, such as an acid agent, later.

According to the present invention, there is provided a chloroprene rubber having a vulcanization rate adjusted to be slow, a production method thereof, and a chloroprene rubber composition without using an additive having a vulcanization delay effect such as a sulfenamide compound.

(First embodiment)
<Chloroprene rubber>
The chloroprene rubber of the present invention contains (1) a chloroprene polymer, (2) elaidic acid, and (3) oleic acid.

(1) Chloroprene polymer The chloroprene polymer is a homopolymer of 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer of chloroprene and other monomers. Monomers copolymerizable with chloroprene include esters of acrylic acid such as methyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, and methacrylates such as methyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate. Acid esters, 2-hydroxyethyl (meth) acrylate, 2-hydroxymethyl (meth) acrylate, hydroxy (meth) acrylates such as 2-hydroxypropyl (meth) acrylate, 2,3-dichloro-1,3- There are butadiene, 1-chloro-1,3-butadiene, butadiene, isoprene, ethylene, styrene, acrylonitrile and the like. These monomers can also be used in combination.

(2) Elaidic acid Elaidic acid is a compound represented by Chemical Formula 1 and is added to slow down the vulcanization rate of chloroprene rubber.

The content of elaidic acid is in the range of 0.0005 to 0.1% by mass in 100% by mass of chloroprene rubber. If the content of elaidic acid is less than 0.0005% by mass, the effect of slowing the vulcanization rate of the chloroprene rubber cannot be obtained. If the content exceeds 0.1% by mass, there is a possibility of bleeding out on the surface of a vulcanized molded body obtained using chloroprene rubber or a chloroprene rubber composition described later. The content of elaidic acid is more preferably in the range of 0.01 to 0.1% by mass.

(3) Oleic acid Oleic acid is a compound represented by Chemical Formula 2 and is added to slow down the vulcanization rate of chloroprene rubber by interaction with the elaidic acid. When chloroprene rubber is made into a vulcanized molded product, it has an effect of maintaining the texture and reducing adhesion of rubber deposits to the molding die.

The content of oleic acid is in the range of 0.0005 to 0.1% by mass in 100% by mass of chloroprene rubber. If the content of oleic acid is less than 0.0005% by mass, the effect of slowing the vulcanization rate of the chloroprene rubber cannot be obtained. When the content exceeds 0.1% by mass, an effect of reducing the deterioration of the texture of a vulcanized molded body obtained by using chloroprene rubber or a chloroprene rubber composition described later and the adhesion of rubber deposits to a molding die can be obtained. There may not be. The content of oleic acid is more preferably in the range of 0.001 to 0.1% by mass.

The contents of elaidic acid and oleic acid contained in the chloroprene rubber can be quantified according to JIS K 6229. Specifically, the chloroprene rubber is cut into a eggplant-shaped flask attached to a condenser, and extracted with an ethanol-toluene azeotrope (ETA) defined in JIS K 6229 (4.5). After methyl esterification with a methylating reagent, it may be quantified using a gas chromatograph.

Other components In addition to the elaidic acid and the oleic acid, the chloroprene rubber includes secodehydroabietic acid, 8,15-isopimarinic acid, dihydropimarinic acid, 8,15-pimarinic acid, dihydro, as components contained in the emulsifier. Isopimaric acid, pimaric acid, dihydroabietic acid, sandaracopimalic acid, dihydro8 (9) -abietic acid, 7-dihydroisopimarinic acid, pulpstriic acid, dihydro-7-abietic acid, 7,15-isopimarinic acid, Deisopropyl dehydroabietic acid, dehydroabietic acid, 6-dehydrodehydroabietic acid, neoabietic acid, demethyldehydroabietic acid and other rosin acids may be included. Further, the chloroprene rubber of this embodiment further includes octadecenoic acid, margaric acid, myristic acid, palmitic acid, methyl diethylcarbamate, arachidonic acid, isostearic acid, stearic acid, linoleic acid, pinolenic acid, linolenic acid, eicosadienoic acid. In some cases, fatty acids such as

(Second Embodiment)
<Chloroprene rubber composition>
The chloroprene rubber composition is obtained by adding disproportionated tall oil soap containing elaidic acid and oleic acid to chloroprene rubber, and (4) 0.005 to 4% by mass of elaidic acid, and (5) olein. It contains 0.0005 to 4% by mass of an acid.
The chloroprene rubber is a rubber containing a chloroprene homopolymer or a copolymer of chloroprene and other monomers, and does not contain the chloroprene rubber of the first embodiment described above, elaidic acid and oleic acid. Chloroprene rubber can be used.

(4) Elaidic acid Elaidic acid is a compound represented by the above chemical formula 1, and is added to slow down the vulcanization rate of the chloroprene rubber composition.

The content of elaidic acid in the chloroprene rubber composition is set in the range of 0.0005 to 4% by mass. The range of 0.0005 to 2.5% by mass is preferable. As the chloroprene rubber in the chloroprene rubber composition, any of those containing elaidic acid and those not containing elaidic acid may be used.

When the chloroprene rubber containing elaidic acid and oleic acid is used, 0.0005 to 0.1% by mass of elaidic acid is contained in the chloroprene rubber, so the content of elaidic acid in the chloroprene rubber composition Is set in the range of 0.0006 to 4 mass%. The range of 0.0006 to 2.5% by mass is preferable.

If the content of elaidic acid in the chloroprene rubber composition is less than the aforementioned range, the effect of slowing the vulcanization rate of the chloroprene rubber composition cannot be obtained. Moreover, when it contains exceeding 4 mass%, there exists a possibility of bleeding out on the surface of the vulcanization molded object obtained using a chloroprene rubber composition.

The content of elaidic acid in the chloroprene rubber composition is the total amount of elaidic acid derived from the disproportionated tall oil soap added later and the amount of elaidic acid contained in the chloroprene rubber.

(5) Oleic acid Oleic acid is a compound represented by the above-mentioned chemical formula 2, and is added to slow down the vulcanization rate of the chloroprene rubber composition by interaction with the elaidic acid. When the chloroprene rubber composition is made into a vulcanized molded product, it has an effect of maintaining the texture and reducing adhesion of rubber deposits to the molding die.

The content of oleic acid in the chloroprene rubber composition is set in the range of 0.0005 to 4% by mass. The range of 0.0005 to 2.5% by mass is preferable. As the chloroprene rubber in the chloroprene rubber composition, any of those containing oleic acid and those not containing oleic acid may be used.

When chloroprene rubber containing elaidic acid and oleic acid is used, 0.0005 to 0.1% by mass of oleic acid is contained in the chloroprene rubber, so the content of oleic acid in the chloroprene rubber composition Is set in the range of 0.0006 to 4 mass%. The range of 0.0006 to 2.5% by mass is preferable.

If the content of oleic acid in the chloroprene rubber composition is less than the aforementioned range, the effect of slowing the vulcanization rate of the chloroprene rubber composition may not be obtained. Moreover, when it contains exceeding 4 mass%, the effect of reducing the deterioration of the feel of the vulcanization molded object obtained using a chloroprene rubber composition and adhesion of the rubber deposit to a molding die may not be acquired. .

The content of oleic acid in the chloroprene rubber composition is the total amount of oleic acid derived from the disproportionated tall oil soap added later and the amount of oleic acid contained in the chloroprene rubber.

The contents of elaidic acid and oleic acid contained in the chloroprene rubber composition can be quantified according to JIS K 6229. Specifically, the chloroprene rubber composition was cut and placed in an eggplant-shaped flask attached to a condenser, and extracted with an ethanol-toluene azeotrope (ETA) defined in JIS K 6229 (4.5). The resin may be quantified using a gas chromatograph after methyl esterification with a methylating reagent.

The chloroprene rubber composition includes a vulcanizing agent, a vulcanization accelerator, a filler, a reinforcing agent, a softening agent, a plasticizer, a lubricant, an anti-aging agent, a stabilizer, and a silane coupling as long as the effects of the present invention are not impaired. An agent, an acid acceptor and the like can also be blended.

Chloroprene rubber and chloroprene rubber composition, after adding vulcanizing agent, vulcanization accelerator, etc., press vulcanization, injection molding vulcanization, vulcanization can vulcanization, UHF vulcanization, LCM vulcanization, HFB vulcanization, etc. The vulcanized molded product can be obtained by vulcanization by the above method. The vulcanization temperature at that time can be appropriately set depending on the composition of the chloroprene rubber or chloroprene rubber composition and the type of the vulcanizing agent. Usually, the range of 130 to 190 ° C is preferable, and the range of 140 to 180 ° C is more preferable.

(Third embodiment)
<Method for producing chloroprene rubber>
The chloroprene rubber is obtained by subjecting a raw material monomer containing chloroprene to emulsion polymerization using (B) a polymerization catalyst and (C) a chain transfer agent in the presence of an emulsifier containing (A) elaidic acid and oleic acid. After reaching the degree of polymerization (D), the polymerization can be stopped by adding a polymerization terminator and then removing the unreacted monomer.

(A) Emulsifier containing elaidic acid and oleic acid An emulsifier is used to emulsify a raw material monomer containing chloroprene in water as a solvent. In this embodiment, an emulsifier containing elaidic acid and oleic acid is used as the emulsifier.

The content of elaidic acid contained in the emulsifier is in the range of 0.01 to 0.2% by mass, preferably 0.01 to 0.1% by mass, in 100% by mass of the emulsifier. By using an emulsifier having an elaidic acid content in this range, a chloroprene rubber containing 0.0005 to 0.1% by mass of elaidic acid under ordinary emulsion polymerization conditions can be obtained.
If the amount of elaidic acid contained in the emulsifier is less than 0.01% by mass, the amount of elaidic acid contained in the resulting chloroprene rubber is insufficient and the vulcanization rate cannot be slowed down. Moreover, when it exceeds 0.2 mass%, an elaidic acid may bleed out on the surface of the vulcanization molding of the obtained chloroprene rubber or chloroprene rubber composition.

The content of oleic acid contained in the emulsifier is in the range of 0.01 to 0.2% by mass and more preferably 0.01 to 0.1% by mass in 100% by mass of the emulsifier. By using an emulsifier having an oleic acid content within this range, a chloroprene rubber containing 0.0005 to 0.1% by mass of oleic acid under ordinary emulsion polymerization conditions can be obtained.
If the oleic acid contained in the emulsifier is less than 0.01% by mass, the amount of oleic acid contained in the resulting chloroprene rubber is insufficient and the vulcanization rate cannot be slowed down. Further, when the content exceeds 0.1% by mass, when chloroprene rubber and chloroprene rubber composition are made into a vulcanized molded product, an effect of reducing the deterioration of the texture and adhesion of rubber deposits to the molding die can be obtained. There may not be.

The emulsifier may contain fatty acids other than elaidic acid and oleic acid. As an emulsifier, rosin acid generally used in emulsion polymerization of chloroprene may be used in combination.

(B) Polymerization catalyst A polymerization catalyst is added in order to perform the emulsion polymerization reaction of the raw material monomer containing chloroprene efficiently. As a polymerization catalyst, what is used for the emulsion polymerization of normal chloroprene can be used. Specifically, there are organic peroxides such as inorganic peroxides, persulfates, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides.

(C) Chain transfer agent A chain transfer agent is added in order to accelerate the emulsion polymerization reaction of the raw material monomer containing chloroprene. As the chain transfer agent, those used for usual emulsion polymerization of chloroprene can be used. Specific examples include long-chain alkyl mercaptans such as n-dodecyl mercaptan, tert-dodecyl mercaptan and n-octyl mercaptan, dialkylxanthogen disulfides such as diisopropylxanthogen disulfide and diethylxanthogen disulfide, and iodoform.

(D) Polymerization terminator A polymerization terminator is added in order to stop the emulsion polymerization reaction of the raw material monomer containing chloroprene. As the polymerization terminator, those used for usual emulsion polymerization of chloroprene can be used. Specific examples include phenothiazine, para-t-butylcatechol, hydroquinone, hydroquinone monomethyl ether, diethylhydroxylamine, thiodiphenylamine, and 1,3,5-trihydroxybenzene.

The reaction temperature of the emulsion polymerization reaction of chloroprene may be within a range in which normal emulsion polymerization is performed. The final polymerization rate of chloroprene can be arbitrarily adjusted within a range of 50 to 100%.

As described in detail above, the chloroprene rubber according to the first embodiment and the chloroprene rubber composition according to the second embodiment of the present invention contain specific amounts of elaidic acid and oleic acid, so that the vulcanization rate is adjusted slowly. can do. More specifically, the vulcanization rate can be adjusted to be 10 to 50% slower than that of chloroprene rubber used for general industrial rubber products. Moreover, in this chloroprene rubber composition and chloroprene rubber, since the vulcanization rate can be adjusted slowly without using a sulfenamide compound as an additive, inhibition of foaming can be prevented.

(Example 1)
<Production of chloroprene rubber>
A four-necked flask with an internal volume of 5 liters was charged with 90 parts by mass of pure water and 3.5 parts by mass of an emulsifier containing 0.04% by mass of elaidic acid and 0.03% by mass of oleic acid, and stirred under a nitrogen stream. While adding 100 parts by mass of chloroprene monomer and 0.6 parts by mass of sulfur, a polymerization solution was prepared. 0.1 parts by mass of potassium persulfate was added to the polymerization solution as a catalyst and polymerized at 40 ° C. in a nitrogen atmosphere. When the final polymerization rate reached 73%, an emulsion containing 0.07 parts by mass of phenothiazine was added. The polymerization was stopped and unreacted monomers were removed under reduced pressure. Diluted acetic acid was added to the polymerization solution in which the polymerization was stopped to adjust its pH to 6.0, and a solid chloroprene rubber was obtained from the prepared polymerization solution by freeze coagulation drying.

<Preparation of composition for evaluation>
Using a kneading roll machine, 100 parts by mass of the chloroprene rubber produced by the above-described method, 0.5 part by mass of stearic acid, 4.0 parts by mass of magnesium oxide and 5.0 parts by mass of zinc oxide were used in accordance with JIS K 6299. And kneaded to obtain a composition for evaluation.

<Vulcanization characteristics>
The scorch time t5 and scorch time ts0.2 shown below were measured for the composition for evaluation obtained by the above method.

(Scorch time t5)
The Mooney scorch test at 125 ° C. was performed on the evaluation composition obtained by the above-mentioned method in accordance with JIS-K 6300-1, and the “scorch time t5” was measured. In consideration of actual product use, the “scorch time t5” was determined to be acceptable if it showed a value between 25 minutes and 40 minutes.
“Scorch time t5” represents the time (minutes) required for the viscosity of the evaluation composition to rise from the lowest viscosity to 5% when the scorch time is measured.

(Scorch time ts0.2)
The composition for evaluation obtained by the method described above was applied at 150 ° C. in accordance with JIS K6300-2 using a vibration vulcanization tester (AUTOMATIC ROTORLES RHEOMETER ALR-2) manufactured by Toyo Seiki Seisakusho Co., Ltd. A sulfur test was conducted to measure “scorch time ts0.2”. In consideration of actual product use, “scorch time ts0.2” was determined to be acceptable if it showed a value between 3.5 minutes and 5.0 minutes. This value indicates that the vulcanization rate was reduced by 10 to 50% compared to the chloroprene rubber (chloroprene rubber of Comparative Example 1 and Comparative Example 2) used for general industrial rubber products.
“Scorch time ts0.2” means the time (minutes) required for the measured torque to rise from the minimum torque ML to 0.2% of the maximum torque MH when a vulcanization test is performed using a vibration vulcanization tester. Represents.

The chloroprene rubber of Example 1 contains 0.0007% by mass of elaidic acid and 0.0005% by mass of oleic acid in 100% by mass of chloroprene rubber. The scorch time t5 is 28 minutes, the scorch time ts0. 2 was 43.7 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 12% longer.

The chloroprene rubbers of Examples 2 to 4 and Comparative Examples 1 and 2 shown in Table 1 will be described. These chloroprene rubbers were produced by producing chloroprene rubber in the same manner as in Example 1 and evaluating the vulcanization characteristics in the same manner as in Example 1 except that the conditions for producing the chloroprene rubber were changed as follows.

(Example 2)
When the chloroprene rubber of Example 2 was used to produce the chloroprene rubber, the emulsifier used in Example 1 was added to 4.75 parts by mass of an emulsifier containing 0.03% by mass of elaidic acid and 0.026% by mass of oleic acid. While changing, the addition amount of sulfur is changed to 0.5 mass part.
The chloroprene rubber of Example 2 contains 0.001% by mass of elaidic acid and 0.0009% by mass of oleic acid in 100% by mass of chloroprene rubber. The scorch time t5 is 29 minutes and the scorch time ts0. 2 was 4.2 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 27% longer.

(Example 3)
When the chloroprene rubber of Example 3 was used to prepare the chloroprene rubber, the emulsifier used in Example 1 was added to 8.0 parts by mass of an emulsifier containing 0.06% by mass of elaidic acid and 0.047% by mass of oleic acid. While changing, the addition amount of sulfur is changed to 0.5 mass part.
The chloroprene rubber of Example 3 contains 0.01% by mass of elaidic acid and 0.009% by mass of oleic acid in 100% by mass of chloroprene rubber. The scorch time t5 is 30 minutes, the scorch time ts0. 2 was 4.5 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 36% longer.

Example 4
The chloroprene rubber of Example 4 was prepared by adding the emulsifier used in Example 1 to 3.5 parts by mass of an emulsifier containing 0.20% by mass of elaidic acid and 0.18% by mass of oleic acid. While changing, the addition amount of sulfur is changed to 0.5 mass part.
The chloroprene rubber of Example 4 contains 0.1% by mass of elaidic acid and 0.1% by mass of oleic acid in 100% by mass of chloroprene rubber. The scorch time t5 is 35 minutes, the scorch time ts0. 2 was 5.0 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 50% longer.

(Comparative Example 1)
The chloroprene rubber of Comparative Example 1 was obtained using rosin acid containing no elaidic acid and oleic acid as emulsifiers when the chloroprene rubber was produced in Example 1.
The chloroprene rubber of Comparative Example 1 is a chloroprene rubber that does not contain elaidic acid and oleic acid, and is a chloroprene rubber used for general industrial rubber products. When vulcanization characteristics were measured in the same manner as in Example 1, the scorch time t5 was 28 minutes, and the scorch time ts0.2 was 3.3 minutes.

(Comparative Example 2)
When the chloroprene rubber of Comparative Example 2 was prepared in Example 1, the emulsifier was changed to 30 parts by mass of an emulsifier containing 0.06% by mass of elaidic acid and 0.047% by mass of oleic acid, The amount of sulfur added is changed to 0.5 parts by mass.
The chloroprene rubber of Comparative Example 2 contains 0.15% by mass of elaidic acid and 0.15% by mass of oleic acid in 100% by mass of chloroprene rubber. When vulcanization characteristics were measured in the same manner as in Example 1, the scorch time t5 was 45 minutes and the scorch time ts0.2 was 8.2 minutes. This value indicates that the vulcanization time has become too long.

The chloroprene rubber compositions of Examples 5 to 7 and Comparative Example 3 shown in Table 2 will be described. These chloroprene rubber compositions were not applied to the chloroprene rubber of Example 1, the chloroprene rubber of Comparative Example 2, or the chloroprene rubber not containing elaidic acid and oleic acid using a kneading roll machine in accordance with JIS K 6299. It was obtained by kneading soaked soya soap. The obtained chloroprene rubber composition was used as an evaluation composition in the same manner as in Example 1, and the vulcanization characteristics were evaluated in the same manner as in Example 1.

(Example 5)
In the chloroprene rubber composition of Example 5, 0.5 parts by weight of disproportionated tall oil soap containing 15.2% by mass of elaidic acid and 14.3% by mass of oleic acid was added to the chloroprene rubber of Example 1. Is.
The chloroprene rubber composition of Example 5 contains 2.9% by mass of elaidic acid and 2.9% by mass of oleic acid in 100% by mass of the chloroprene rubber composition, and the scorch time t5 is 31 minutes. The scorch time ts0.2 was 4.5 minutes.
Compared to the chloroprene rubber composition of Comparative Example 1, the scorch time ts0.2 was about 36% longer.

(Example 6)
The chloroprene rubber composition of Example 6 is a disproportionated tall oil soap containing 15.2% by mass of elaidic acid and 14.3% by mass of oleic acid in 100 parts by mass of chloroprene rubber not containing elaidic acid and oleic acid. Is added 0.001 part by mass.
The chloroprene rubber composition of Example 6 contains 0.001% by mass of elaidic acid and 0.0009% by mass of oleic acid in 100% by mass of the chloroprene rubber composition, and the scorch time t5 is 28 minutes. The scorch time ts0.2 was 3.8 minutes.
Compared to the chloroprene rubber composition of Comparative Example 1, the scorch time ts0.2 was about 15% longer.

(Example 7)
The chloroprene rubber composition of Example 7 is a disproportionated tall oil soap containing 15.2% by mass of elaidic acid and 14.3% by mass of oleic acid in 100 parts by mass of chloroprene rubber not containing elaidic acid and oleic acid. Is added 0.5 parts by mass.
The chloroprene rubber composition of Example 7 contains 2.8% by mass of elaidic acid and 2.8% by mass of oleic acid in 100% by mass of the chloroprene rubber composition, and the scorch time t5 is 30 minutes. The scorch time ts0.2 was 4.2 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 27% longer.

(Comparative Example 3)
The chloroprene rubber composition of Comparative Example 3 contains 1.5 parts of disproportionated tall oil soap containing 15.2% by mass of elaidic acid and 14.3% by mass of oleic acid in 100 parts by mass of the chloroprene rubber of Comparative Example 2. Mass parts are added.
The chloroprene rubber of Comparative Example 3 contains 4.2% by mass of elaidic acid and 4.2% by mass of oleic acid in 100% by mass of the chloroprene rubber composition, and the scorch time t5 is 50 minutes. The ts0.2 was 10.1 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 200% longer.

As shown in Table 1 and Table 2, the chloroprene rubber and the chloroprene rubber composition of each example within the scope of the present invention are compared with the chloroprene rubber (Comparative Example 1) used for general industrial rubber products. It was confirmed that the 10-50% vulcanization rate was adjusted to be slow.

Claims (4)

A chloroprene rubber containing 0.0005 to 0.1% by mass of elaidic acid and 0.0005 to 0.1% by mass of oleic acid in 100% by mass of chloroprene rubber having a chloroprene polymer. The chloroprene rubber according to claim 1 or chloroprene rubber having a chloroprene polymer and containing no elaidic acid and oleic acid, 99.999 to 92% by mass, elaidic acid 0.0005 to 4% by mass, and oleic acid 0. A chloroprene rubber composition containing 0005 to 4% by mass. A chloroprene rubber composition in which elaidic acid and elaidic acid contained in the chloroprene rubber composition according to claim 2 are derived from disproportionated tall oil soap. In the presence of an emulsifier containing elaidic acid 0.01 to 0.2% by mass and oleic acid 0.01 to 0.2% by mass, chloroprene alone or chloroprene and other monomers are emulsion-polymerized. The method for producing a chloroprene rubber according to claim 1, wherein a chloroprene polymer is obtained.