JP6092707B2 - Chloroprene rubber composition, chloroprene rubber and method for producing the same - Google Patents

Description

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

  Chloroprene rubber is a synthetic rubber excellent in 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 to be about 10 to 50% slower than chloroprene rubber used in general industrial rubber products.

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

JP 2011-1528 A

  By using the sulfenamide-based compound described in Patent Document 1, the vulcanization rate of the 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 composition, a chloroprene rubber, and a method for producing the same, in which a vulcanization rate is adjusted to be slow without using an additive having a vulcanization delay effect such as a sulfenamide compound. To do.

In the present invention, a chloroprene rubber containing a chloroprene homopolymer or a copolymer of chloroprene and other monomers, 0.005 to 4% by mass of elaidic acid, and 0.0005 to 4% by mass of oleic acid. A composition is provided.
The chloroprene rubber composition according to the present invention is a disproportionated toll containing the chloroprene homopolymer or the chloroprene rubber having a copolymer of chloroprene and another monomer, the elaidic acid and the oleic acid. It may be obtained by kneading oil soap.
At this time, the chloroprene rubber may not contain the elaidic acid and the oleic acid.
On the other hand, the chloroprene rubber contains 0.005 to 0.1% by mass of the elaidic acid and 0.0005 to 0.1% by mass of the oleic acid, and contains the elaidic acid per total mass of the composition. The amount may be 0.0006 to 4% by mass, and the content of the oleic acid may be 0.0006 to 4% by mass.

  In the present invention, a chloroprene homopolymer or a copolymer of chloroprene and other monomers, 0.005 to 0.1% by mass of elaidic acid, 0.0005 to 0.1% by mass of oleic acid, A chloroprene rubber containing, is also provided.

  In the present invention, chloroprene alone or chloroprene and other monomers 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. And a method for producing a chloroprene rubber which obtains 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 the total mass.

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 are provided a chloroprene rubber composition, a chloroprene rubber, and a method for producing the same, in which a vulcanization rate is adjusted to be slow without using an additive having a vulcanization delay effect such as a sulfenamide compound.

(First embodiment)
<Chloroprene rubber composition>
First, the chloroprene rubber composition according to the first embodiment of the present invention will be described. The chloroprene rubber composition of the first embodiment of the present invention comprises (1) a chloroprene polymer, (2) 0.005 to 4% by mass of elaidic acid, and (3) 0.0005 to 4% by mass of oleic acid. Containing. This chloroprene rubber composition is obtained by adding disproportionated tall oil soap containing elaidic acid and oleic acid to chloroprene rubber containing elaidic acid and oleic acid or chloroprene rubber not containing these compounds. is there.

(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 another monomer. 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 contained in the chloroprene rubber composition of the present embodiment is a compound represented by 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. Preferably the range of 0.0005-2.5 mass% is good. 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, and the content of elaidic acid in the chloroprene rubber composition is reduced. It sets to the range of 0.0006-4 mass%. Preferably the range of 0.0006-2.5 mass% is good.

  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.

(3) Oleic acid The oleic acid contained in the chloroprene rubber composition of the present embodiment is a compound represented by the chemical formula 2, and slows the vulcanization rate of the chloroprene rubber composition by interaction with the elaidic acid. To be added. In addition, 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. Preferably the range of 0.0005-2.5 mass% is good. As the chloroprene rubber in the chloroprene rubber composition, any of those containing oleic 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 oleic acid is contained in the chloroprene rubber, and the content of oleic acid in the chloroprene rubber composition is It sets to the range of 0.0006-4 mass%. Preferably the range of 0.0006-2.5 mass% is good.

  If the content of oleic acid in the chloroprene rubber composition is less than the above 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 oleic acid content 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 into a eggplant-shaped flask attached to a condenser, and extracted using 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.

  The chloroprene rubber composition and the chloroprene rubber described below are added to a vulcanizing agent, a vulcanization accelerator, etc., and then press vulcanized, injection molded vulcanized, vulcanized can vulcanized, UHF vulcanized, LCM vulcanized, HFB vulcanized. A vulcanized molded body can be obtained by vulcanization by a method such as vulcanization. The vulcanization temperature at that time can be appropriately set depending on the composition of the chloroprene rubber composition and the type of vulcanizing agent. Usually, the range of 130-190 degreeC is preferable, and the range of 140-180 degreeC is more preferable.

(Second Embodiment)
<Chloroprene rubber>
Next, the chloroprene rubber according to the second embodiment of the present invention will be described. The chloroprene rubber according to the second embodiment of the present invention may be contained in the chloroprene rubber composition according to the first embodiment described above, and includes (1) a chloroprene polymer, (2) elaidic acid, and (3) olein. It contains an acid.

(1) Chloroprene polymer The chloroprene polymer is a homopolymer of chloroprene or a copolymer of chloroprene and another monomer, and is contained in the chloroprene rubber composition of the first embodiment described above. It can be set as the structure similar to a polymer.

(2) Elaidic acid Elaidic acid has the effect of slowing down the vulcanization rate of chloroprene rubber. The content of elaidic acid in the chloroprene rubber is in the range of 0.0005 to 0.1% by mass in 100% by mass of the 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. Moreover, when it contains exceeding 0.1 mass%, there exists a possibility of bleeding out on the surface of the vulcanization molding obtained using chloroprene rubber or a chloroprene rubber composition. The content of elaidic acid is more preferably in the range of 0.01 to 0.1% by mass.

(3) Oleic acid Oleic acid slows down the vulcanization rate of chloroprene rubber by interaction with the elaidic acid. In addition, 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 in the chloroprene rubber is in the range of 0.0005 to 0.1% by mass in 100% by mass of the 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. Moreover, when it contains exceeding 0.1 mass%, the effect of reducing the deterioration of the texture of the vulcanized molded body obtained using chloroprene rubber or a chloroprene rubber composition and the adhesion of rubber deposits to the 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 measured by the same procedure as the method for measuring these compounds contained in the chloroprene rubber composition described above.

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

<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 and 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 0.005 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 a content of oleic acid 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. Moreover, the final polymerization rate of chloroprene can be arbitrarily adjusted within the range of 50 to 100%.

  As described in detail above, the chloroprene rubber composition of the first embodiment of the present invention and the chloroprene rubber of the second embodiment contain specific amounts of elaidic acid and oleic acid, so that the vulcanization rate is adjusted slowly. can do. More specifically, for example, the vulcanization rate can be adjusted 10 to 50% slower than 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 sheet-like chloroprene rubber was obtained by a freeze coagulation drying method.

<Preparation of chloroprene rubber composition (composition for evaluation)>
The chloroprene rubber composition of Example 1 contains 0 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 produced by the method described above. In addition to 0.5 parts by mass, 0.5 parts by mass of stearic acid, 4.0 parts by mass of magnesium oxide, and 5.0 parts by mass of zinc oxide are kneaded using a kneading roll machine in accordance with JIS K 6299.

<Evaluation of chloroprene rubber composition>
About the composition for evaluation obtained by the above-mentioned method, scorch time t5 and scorch time ts0.2 shown below were measured.

(Scorch time t5)
The chloroprene rubber composition for measurement obtained by the above-described method was subjected to a Mooney scorch test at 125 ° C. in accordance with JIS-K 6300-1, and “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 chloroprene rubber composition to rise from the lowest viscosity to 5% when the scorch time is measured.

(Scorch time ts0.2)
The chloroprene rubber composition for measurement obtained by the above-described method is 150 based on JIS K6300-2 using a vibration vulcanization tester (AUTOMATIC ROTORLES RHEOMETER ALR-2) manufactured by Toyo Seiki Seisakusho Co., Ltd. A vulcanization test was conducted at 0 ° C. 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 represents that the vulcanization rate was slowed 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 composition of Example 1 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 described later, the scorch time ts0.2 was about 36% longer.

  Next, the chloroprene rubber compositions of Examples 2 and 3 and Comparative Examples 1 and 2 shown in Table 1 below, and the chloroprene rubbers of Examples 4 to 7 and Comparative Example 3 shown in Table 2 will be described. These chloroprene rubber compositions or chloroprene rubbers were produced in the same manner as in Example 1 by changing the conditions for producing chloroprene rubber or additives to be added to the obtained chloroprene rubber as shown below. It was evaluated in the same way.

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

(Example 2)
The chloroprene rubber composition of Example 2 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.
The chloroprene rubber composition of Example 2 contains 0.001% 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 1. Mass parts are added.

(Example 3)
The chloroprene rubber composition of Example 3 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.
The chloroprene rubber composition of Example 3 contains 0.5 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 1. Mass parts are added.

(Comparative Example 2)
The chloroprene rubber composition of Comparative Example 2 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 scorch time ts0.2 was 10.1 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 200% longer.
When the chloroprene rubber composition of Comparative Example 2 was used to produce the chloroprene rubber 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. In addition, the amount of sulfur added was changed to 0.5 parts by mass to obtain chloroprene rubber, and the resulting chloroprene rubber contained disproportionate containing 15.2% by mass of elaidic acid and 14.3% by mass of oleic acid. This is the addition of 1.5 parts by mass of tall oil soap.

Example 4
The chloroprene rubber of Example 4 contains 0.0007% by mass of elaidic acid and 0.0005% by mass of oleic acid in 100% by mass of chloroprene rubber. In Example 4, 0.5 parts by mass of stearic acid, 4.0 parts by mass of magnesium oxide and 5.0 parts by mass of zinc oxide were added to 100 parts by mass of chloroprene rubber using a kneading roll machine in accordance with JIS K 6299. The composition for evaluation was obtained by kneading. When the vulcanization characteristics of the composition for evaluation were measured, the scorch time t5 was 28 minutes and the scorch time ts0.2 was 3.7 minutes.
Compared to chloroprene rubber (chloroprene rubber of Comparative Example 1) used for general industrial rubber products, the scorch time ts0.2 was delayed by about 12%.

(Example 5)
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.
When the chloroprene rubber of Example 5 was used to prepare the chloroprene rubber, the emulsifier used in Example 4 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.

(Example 6)
The chloroprene rubber of Example 6 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.
When the chloroprene rubber of Example 6 was used to prepare the chloroprene rubber, the emulsifier used in Example 4 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.

(Example 7)
The chloroprene rubber of Example 7 contains 0.1% by mass of elaidic acid and 0.1% by mass of oleic acid in 100% by mass of chloroprene rubber. 2 was 5.0 minutes.
Compared to the chloroprene rubber of Comparative Example 1, the scorch time ts0.2 was about 50% longer.
The chloroprene rubber of Example 7 was prepared by adding the emulsifier used in Example 4 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.

(Comparative Example 3)
The chloroprene rubber of Comparative Example 3 contains 0.15% by mass of elaidic acid and 0.15% by mass of oleic acid in 100% by mass of chloroprene rubber. When a composition for evaluation was obtained in the same manner as in Example 4 and the vulcanization characteristics thereof were measured, 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.
When the chloroprene rubber of Comparative Example 3 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.

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

Claims (3)

Chloroprene rubber having a chloroprene homopolymer or a copolymer of chloroprene and other monomers;
A chloroprene rubber composition obtained by kneading disproportionated tall oil soap containing elaidic acid and oleic acid,
The chloroprene rubber is
0.005 to 0.1% by mass of elaidic acid,
0.005 to 0.1% by weight of oleic acid,
Per total mass of the composition,
The content of elaidic acid is 0.0006-4% by mass,
A chloroprene rubber composition having an oleic acid content of 0.0006 to 4 mass% . A chloroprene homopolymer or a copolymer of chloroprene and other monomers;
0.005 to 0.1% by mass of elaidic acid,
A chloroprene rubber containing oleic acid in an amount of 0.0005 to 0.1% by mass. In the presence of an emulsifier containing elaidic acid 0.01-0.2% by mass and oleic acid 0.01-0.2% by mass, chloroprene alone or chloroprene and other monomers are emulsion-polymerized,
A method for producing chloroprene rubber, which obtains chloroprene rubber containing 0.005 to 0.1% by mass of elaidic acid and 0.0005 to 0.1% by mass of oleic acid in the total mass.