JP2016141736A - Chloroprene rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chloroprene rubber composition long in scorch time and excellent in storage stability.SOLUTION: There is provided a chloroprene rubber composition containing an amine salt of dithiocarbamic acid of 1 to 10 pts.wt. based on 100 pts.wt. of a chloroprene rubber and a chloroprene rubber composition containing further at least one kind of compound selected from a group consisting of a thiuram-based vulcanization accelerator, a guanidine-based vulcanization accelerator, a thiazole-based vulcanization accelerator and a sulfenamide-based vulcanization accelerator of 0.1 to 5 pts.wt. with the chloroprene rubber composition.SELECTED DRAWING: None

Description

  The present invention relates to a chloroprene rubber composition, and more particularly to a chloroprene rubber composition having a long scorch time and excellent storage stability.

  Chloroprene rubber is a synthetic rubber excellent in ozone resistance, heat resistance, oil resistance, and chemical resistance, and is used in various automobile parts, electric wires, hoses, adhesives, etc. taking advantage of these characteristics. Ethylenethiourea, trimethylthiourea, and the like are used as vulcanization accelerators for chloroprene rubber. However, an unvulcanized rubber compound containing ethylene thiourea as a vulcanization accelerator has a short scorch time and often causes problems such as burning. In addition, an unvulcanized rubber compound containing trimethylthiourea as a vulcanization accelerator has a long scorch time but is inferior in storage stability. In addition, as a conventional technique for prolonging the scorch time, a method of blending iron oxide or alkyl tin sulfite has been proposed, but the tensile strength and hardness were lower than those of ethylene thiourea (see, for example, Patent Documents 1 and 2). . Therefore, a vulcanization accelerator that combines a long scorch time and excellent storage stability has been desired.

Japanese Patent Laid-Open No. 2001-323109 Japanese Patent Laid-Open No. 2001-181451

  The present invention has been made in view of the problems described above, and provides a chloroprene rubber composition having a long scorch time and excellent storage stability.

  As a result of intensive studies to solve the above-described problems, the present inventors have completed the present invention. That is, the present invention is a chloroprene rubber composition comprising 1 to 10 parts by weight of an amine salt of dithiocarbamic acid with respect to 100 parts by weight of chloroprene rubber.

  The present invention is described in detail below.

  The chloroprene rubber composition of the present invention contains 1 to 10 parts by weight of an amine salt of dithiocarbamic acid with respect to 100 parts by weight of chloroprene rubber.

  As the chloroprene rubber contained in the chloroprene rubber composition of the present invention, all of the conventionally known chloroprene rubbers can be used, and not only one type but also two or more types of combinations can be used. The comonomer contained in the chloroprene rubber in the present invention is not particularly limited as long as it is a monomer copolymerizable with chloroprene, and examples thereof include monovinyl compounds such as acrylonitrile, methacrylonitrile, vinylidene chloride, and acrylate esters. , Methacrylates, aromatic vinyl compounds such as styrene and α-methylstyrene, conjugates such as 1,3-butadiene, 1-chloro-1,3-butadiene, 2,3-dichloro-1,3-butadiene A diene compound, sulfur, etc. are mentioned, These can be used individually or in combination of 2 or more types. The comonomer content in the chloroprene rubber is 0 to 50% by weight, and if it exceeds 50% by weight, the properties of the chloroprene rubber are impaired.

  The chloroprene rubber in the present invention is produced by a known method such as emulsion polymerization, solution polymerization or bulk polymerization. For example, taking emulsion polymerization as an example, it is produced by the following method.

  A mixture of a monomer component and an arbitrary amount of a molecular regulator is mixed with an aqueous emulsifier solution and emulsified. Polymerization is performed by adding a polymerization initiator to this emulsion, and polymerization is terminated by adding a polymerization terminator at an arbitrary conversion rate. The molecular weight regulator, emulsifier, polymerization initiator, and terminator used in the polymerization are not particularly limited.

  Although superposition | polymerization temperature is not specifically limited, The temperature of 0-60 degreeC is preferable and the temperature of 5-50 degreeC is more preferable. When the heat generation during polymerization is large and it is difficult to control the temperature, the polymerization can be carried out while adding the monomer mixture to the aqueous emulsifier solution in small portions or continuously.

  After termination of the polymerization, unreacted monomers in the latex are removed by a method such as reduced-pressure steam stripping, and then the polymer is isolated by freeze coagulation or salting out, and then washed with water and dried to obtain a polymer.

  When two or more kinds of chloroprene rubbers are combined, as a blending method, a method of mixing and blending latexes obtained by polymerization, a method of blending solid polymers by kneading, a solvent such as toluene for blending each solid polymer A method of blending after dissolving and mixing in the solvent and removing the solvent can be used.

  The content of the amine salt of dithiocarbamic acid in the chloroprene rubber composition of the present invention is 1 to 10 parts by weight with respect to 100 parts by weight of the chloroprene rubber. When the content is less than 1 part by weight, physical properties are deteriorated due to poor vulcanization due to insufficient vulcanization accelerator, and when it exceeds 10 parts by weight, curing due to burning occurs. When the content is 2 parts by weight or more, the vulcanization rate is moderate, and when it is 5 parts by weight or less, good tensile strength and elongation at break are obtained, so 2 to 5 parts by weight is preferable.

  Examples of the amine salt of dithiocarbamic acid include dimethylammonium dimethyldithiocarbamate, diethylammonium diethyldithiocarbamate, di-n-propylammonium di-n-propyldithiocarbamate, di-n-butylammonium di-n-butyldithiocarbamate, Di-2-ethylhexyldithiocarbamate di-2-ethylhexylammonium, di-n-octadecyldithiocarbamate di-n-octadecyldithiocarbamate, di-n-triacontanedithiocarbamate di-n-triacontanammonium, dioleyldithiocarbamate diio Rail ammonium, dilinoleyl dithiocarbamate dilinoleyl ammonium, dicyclohexyl dithiocarbamate dicyclohexylammonium Di-2-cyclohexenyl dithiocarbamate di-2-cyclohexenylammonium, di (cyclohexylmethyl) dithiocarbamate di (cyclohexylmethyl) ammonium, di- (2-cyclohexylethyl) dithiocarbamate di- (2-cyclohexylethyl) ammonium, Dibenzylammonium dibenzyldithiocarbamate, azetidinium trimethylenedithiocarbamate, pyrrolidinium tetramethylenedithiocarbamate, piperidinium pentamethylenedithiocarbamate, hexamethyleneammonium hexamethylenedithiocarbamate, decamethyleneammonium decamethylenedithiocarbamate, pipecolinium pipecolyldithiocarbamate, pyrrolidine -N-dithiocarbamate ammonium dime Triethylammonium rudithiocarbamate, triethylammonium diethyldithiocarbamate, triethylammonium di-n-propyldithiocarbamate, triethylammonium di-n-butyldithiocarbamate, triethylammonium di-2-ethylhexyldithiocarbamate, dimethyldithiocarbamate N, N-di -I-propylethylammonium, diethyldithiocarbamate N, N-di-i-propylethylammonium, di-n-propyldithiocarbamate N, N-di-i-propylethylammonium, di-n-butyldithiocarbamate N, N-di-i-propylethylammonium, di-2-ethylhexyldithiocarbamate N, N-di-i-propylethylammonium, di-2-chloro- n-2-propyldithiocarbamate di-2-chloro-n-propylammonium, di-2-methoxyethyldithiocarbamate di-2-methoxyethylammonium, di-3-oxo-n-butyldithiocarbamate di-3-oxo-n -Butylammonium, di- (2-acetoxyethyl) dithiocarbamate di- (2-acetoxyethyl) ammonium, di- (2-acetylaminoethyl) dithiocarbamate di- (2-acetylaminoethyl) ammonium and the like.

  The method of adding the amine salt of dithiocarbamic acid to the chloroprene rubber is not particularly limited. For example, the method of adding to the latex of chloroprene rubber, the method of adding by a kneader such as a closed mixer or an open roll, the chloroprene rubber Examples thereof include a method of adding to a solution dissolved in a solvent such as toluene.

  In the chloroprene rubber composition of the present invention, at least one selected from the group consisting of a thiuram vulcanization accelerator, a guanidine vulcanization accelerator, a thiazole vulcanization accelerator, and a sulfenamide vulcanization accelerator. It is also possible to contain 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight of the compound. When these vulcanization accelerators are contained, sufficient effects of vulcanization acceleration, scorch time extension, improvement of tensile properties, and good vulcanization moldability are exhibited.

  When the chloroprene rubber composition of the present invention contains a thiuram vulcanization accelerator, all the conventionally known thiuram vulcanization accelerators can be used. Commonly known thiuram vulcanization accelerators include, for example, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetra-n-butylthiuram disulfide, tetrakis- (2-ethylhexyl) thiuram disulfide, tetra Examples thereof include benzyl thiuram disulfide and dipentamethylene thiuram tetrasulfide.

  When the chloroprene rubber composition of the present invention contains a guanidine vulcanization accelerator, all of the commonly known guanidine vulcanization accelerators can be used. Commonly known guanidine vulcanization accelerators include, for example, 1,3-diphenylguanidine, 1,3-di-o-toluylguanidine, 1,3-di-o-toluylguanidine salt of dicatechol borate, etc. Is mentioned.

  When the chloroprene rubber composition of the present invention contains a thiazole vulcanization accelerator, all of the commonly known thiazole vulcanization accelerators can be used. Commonly known thiazole vulcanization accelerators include, for example, 2-mercaptobenzothiazole, di-2-benzothiazyl disulfide, cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (4′-morpholyldithio) benzo Examples include thiazole.

  When the chloroprene rubber composition of the present invention contains a sulfenamide-based vulcanization accelerator, all of the conventionally known sulfenamide-based vulcanization accelerators can be used. Commonly known sulfenamide vulcanization accelerators include, for example, N-cyclohexyl-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide, N-oxydiethylene -2-Benzothiazolylsulfenamide, N, N-dicyclohexyl-2-benzothiazolylsulfenamide and the like.

  The chloroprene rubber composition of the present invention can use plasticizers, fillers, reinforcing agents, anti-aging agents, lubricants, processing aids, vulcanizing agents and the like used in conventional rubbers or resins.

  The vulcanization method for obtaining the vulcanizate of the present invention is not particularly limited, and for example, press vulcanization, kettle vulcanization, UHV vulcanization and the like can be used.

  The end use of the chloroprene rubber composition of the present invention includes various automobile parts, electric wires, hoses, adhesives, and the like, similar to the existing chloroprene rubber.

  The chloroprene rubber composition of the present invention has a long scorch time and excellent storage stability.

  Next, the present invention will be specifically described based on examples.

  In addition, the value used in these Examples was obtained based on the following measuring methods.

<Mooney scorch test of unvulcanized rubber>
In accordance with JIS K 6300, the scorch time (t5) and minimum Mooney viscosity (Vm) at a test temperature of 125 ° C. were measured using an L-shaped rotor.

<Storage stability test>
A Mooney scorch test was conducted on a sample that was left in a gear oven at 50 ° C. for 7 days, and ΔVm was obtained from the difference between Vm obtained in the Mooney scorch test after storage and Vm obtained in the Mooney scorch test without storage. It is shown in Table 1.

<Rheometer vulcanization test>
Measurement was performed at 160 ° C. for 45 minutes using RUBBER PROCESS ANALYZER RPA 2000 manufactured by ALPHA TECHNOLOGIES, and the maximum torque value (MH) and 90% vulcanization time (Tc90) were determined according to JIS K 6300.

<Hardness of vulcanized rubber>
In accordance with JIS K 6253, hardness (HS) was measured using a durometer hardness meter.

<Tensile test of vulcanized rubber>
Based on JIS K 6251, tensile strength (TB) and elongation at break (EB) were measured.

  In addition, the content of the compounding agent used by the Example and the comparative example is as follows.

Chloroprene rubber: Skyprene TSR-51 (manufactured by Tosoh Corporation), magnesium oxide: Kyowa Mag 150 (manufactured by Kyowa Chemical Industry Co., Ltd.), stearic acid (manufactured by NOF Corporation), anti-aging agent 1: NOCRACK AD ( Ouchi Shinsei Chemical Co., Ltd.), anti-aging agent 2: Nocrack 6C (Ouchi Shinsei Chemical Co., Ltd.), carbon black: Seast S (Tokai Carbon Co., Ltd.), oil: Sunsen 415 (Japan) Sun Petroleum Co., Ltd.), Zinc Oxide No. 1 (manufactured by Sakai Chemical Co., Ltd.), piperidinium pentamethylenedithiocarbamate (manufactured by Tokyo Chemical Industry Co., Ltd.), diethylammonium diethyldithiocarbamate (manufactured by Tokyo Chemical Industry Co., Ltd.) ), Pipecolinium pipecolic dithiocarbamate (manufactured by Tokyo Chemical Industry Co., Ltd.), pyrrolidine-N-dithiocarbamate ammonium ( Kyosei Kogyo Co., Ltd.), tetramethylthiuram disulfide: Noxeller TT (Ouchi Shinsei Chemical Co., Ltd.), 1,3-diphenylguanidine: Noxeller D (Ouchi Shinsei Chemical Co., Ltd.), Di -2-Benzothiazyl disulfide: Noxeller DM (manufactured by Ouchi Shinsei Chemical Co., Ltd.), N, N-dicyclohexyl-2-benzothiazolylsulfenamide: Noxeller DZ (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) , Ethylenethiourea: Sunseller 22-C (manufactured by Sanshin Chemical Industry Co., Ltd.), Trimethylthiourea: Noxeller TMU (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.)
Example 1
According to the ingredients and amounts shown in Table 1, 100 parts by weight of chloroprene rubber, 4 parts by weight of magnesium oxide, 1 part by weight of stearic acid, 1 part by weight of anti-aging agent 1, 0.5 part by weight of anti-aging agent 2, carbon black 50 parts by weight, 15 parts by weight of oil and 5 parts by weight of zinc oxide were added using a Banbury mixer, and further 2 parts by weight of piperidinium pentamethylenedithiocarbamate was added using an open roll kneader to obtain a chloroprene rubber composition. . The resulting chloroprene rubber composition was subjected to Mooney scorch test, storage stability test, and rheometer vulcanization test for unvulcanized rubber. The obtained chloroprene rubber composition was press vulcanized at 160 ° C. for 60 minutes to obtain a vulcanized product. The obtained vulcanizate was subjected to a tensile test. These results are shown in Table 1. From Table 1, the scorch time t5 was as good as 23 minutes, and the storage stability ΔVm was also as good as 13.

実施例２
ペンタメチレンジチオカルバミン酸ピペリジニウム１重量部を用いた以外は実施例１と同様にクロロプレンゴム組成物及び加硫物を得て、ムーニースコーチ試験、貯蔵安定性試験、レオメータ加硫試験、引張試験を実施し、これらの結果を表１に示す。表１から、スコーチタイムｔ５は２７分と良好で、貯蔵安定性のΔＶｍも１１と良好であった。

Example 2
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 1 part by weight of piperidinium pentamethylenedithiocarbamate was used, and Mooney scorch test, storage stability test, rheometer vulcanization test, and tensile test were performed. These results are shown in Table 1. From Table 1, the scorch time t5 was as good as 27 minutes, and the storage stability ΔVm was also as good as 11.

Example 3
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 5 parts by weight of piperidinium pentamethylenedithiocarbamate was used, and Mooney scorch test, storage stability test, rheometer vulcanization test, and tensile test were performed. These results are shown in Table 1. From Table 1, the scorch time t5 was as good as 19 minutes, and the storage stability ΔVm was also as good as 16.

Example 4
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 10 parts by weight of piperidinium pentamethylenedithiocarbamate was used, and Mooney scorch test, storage stability test, rheometer vulcanization test, and tensile test were performed. These results are shown in Table 1. From Table 1, the scorch time t5 was as good as 15 minutes, and the storage stability ΔVm was as good as 20.

Example 5
A chloroprene rubber composition and a vulcanizate were obtained in the same manner as in Example 1 except that 2 parts by weight of diethylammonium diethyldithiocarbamate was used instead of 2 parts by weight of piperidinium pentamethylenedithiocarbamate, and a Mooney scorch test and storage stability were obtained. A test, a rheometer vulcanization test, and a tensile test were conducted, and the results are shown in Table 1. From Table 1, the scorch time t5 was as good as 27 minutes, and the storage stability ΔVm was also good at 13.

Example 6
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 2 parts by weight of pipecolyl dithiocarbamate pipepecolinium was used in place of 2 parts by weight of pipemethylene dithiocarbamate pentamethylenedithiocarbamate. The test was carried out by a property test, a rheometer vulcanization test and a tensile test, and the results are shown in Table 1. From Table 1, the scorch time t5 was as good as 25 minutes, and the storage stability ΔVm was also as good as 10.

Example 7
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 2 parts by weight of pyrrolidine-ammonium dithiocarbamate was used in place of 2 parts by weight of piperidinium pentamethylenedithiocarbamate. A stability test, a rheometer vulcanization test, and a tensile test were performed, and the results are shown in Table 1. From Table 1, the scorch time t5 was as good as 19 minutes, and the storage stability ΔVm was also as good as 7.

Example 8
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 1 part by weight of tetramethylthiuram disulfide were used instead of 2 parts by weight of piperidinium pentamethylenedithiocarbamate. A Mooney scorch test, a storage stability test, a rheometer vulcanization test, and a tensile test were carried out, and the results are shown in Table 1. From Table 1, the scorch time t5 was as good as 20 minutes, and the storage stability ΔVm was also as good as 12.

Example 9
A chloroprene rubber composition and a vulcanizate were obtained in the same manner as in Example 1 except that 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 1 part by weight of 1,3-diphenylguanidine were used instead of 2 parts by weight of piperidinium pentamethylenedithiocarbamate. The Mooney scorch test, the storage stability test, the rheometer vulcanization test, and the tensile test were carried out, and the results are shown in Table 1. From Table 1, the scorch time t5 was as good as 19 minutes, and the storage stability ΔVm was also as good as 16.

Example 10
A chloroprene rubber composition and vulcanization as in Example 1 except that 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 1 part by weight of di-2-benzothiazyl disulfide were used. The product was obtained and subjected to Mooney scorch test, storage stability test, rheometer vulcanization test, and tensile test. The results are shown in Table 1. From Table 1, the scorch time t5 was as good as 22 minutes, and the storage stability ΔVm was also as good as 10.

Example 11
Chloroprene as in Example 1 except that 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 2 parts by weight of piperidinium pentamethylenedithiocarbamate and 1 part by weight of N, N-dicyclohexyl-2-benzothiazolylsulfenamide were used. A rubber composition and a vulcanized product were obtained, and a Mooney scorch test, a storage stability test, a rheometer vulcanization test, and a tensile test were performed. The results are shown in Table 1. From Table 1, the scorch time t5 was as good as 22 minutes, and the storage stability ΔVm was also as good as 13.

Comparative Example 1
A chloroprene rubber composition and a vulcanizate were obtained in the same manner as in Example 1 except that 1 part by weight of ethylenethiourea was used instead of 2 parts by weight of piperidinium pentamethylenedithiocarbamate, and a Mooney scorch test, storage stability test, rheometer was obtained. A vulcanization test and a tensile test were conducted, and the results are shown in Table 2. From Table 2, the scorch time t5 was as short as 9 minutes, ΔVm was 34, and the storage stability was insufficient.

比較例２
ペンタメチレンジチオカルバミン酸ピペリジニウム２重量部の代わりに、トリメチルチオウレア１．２５重量部を用いた以外は実施例１と同様にクロロプレンゴム組成物及び加硫物を得て、ムーニースコーチ試験、貯蔵安定性試験、レオメータ加硫試験、引張試験を実施し、これらの結果を表２に示す。表２から、スコーチタイムｔ５は１９分と良好であるが、ΔＶｍが２６と貯蔵安定性が不十分だった。

Comparative Example 2
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 1.25 parts by weight of trimethylthiourea was used instead of 2 parts by weight of piperidinium pentamethylenedithiocarbamate, and a Mooney scorch test and a storage stability test were obtained. The rheometer vulcanization test and the tensile test were carried out, and the results are shown in Table 2. From Table 2, the scorch time t5 was as good as 19 minutes, but the ΔVm was 26 and the storage stability was insufficient.

Comparative Example 3
A chloroprene rubber composition and a vulcanized product were obtained in the same manner as in Example 1 except that 0.5 parts by weight of piperidinium pentamethylenedithiocarbamate was used in place of 2 parts by weight of piperidinium pentamethylenedithiocarbamate. A stability test, a rheometer vulcanization test, and a tensile test were performed, and the results are shown in Table 2. From Table 2, the scorch time t5 was as good as 32 minutes and the storage stability ΔVm was as good as 11, but the hardness HS was as low as 41 and vulcanization was insufficient.

Comparative Example 4
An attempt was made to obtain a chloroprene rubber composition and a vulcanizate in the same manner as in Example 1 except that 15 parts by weight of piperidinium pentamethylenedithiocarbamate was used in place of 2 parts by weight of piperidinium pentamethylenedithiocarbamate. Roll kneading could not be performed.

  The chloroprene rubber composition of the present invention has a long scorch time and excellent storage stability, and is compounded and kneaded in the same manner as a conventional rubber or resin, used as a vulcanized product, and used in a wide range of areas. The

Claims (4)

A chloroprene rubber composition comprising 1 to 10 parts by weight of an amine salt of dithiocarbamic acid with respect to 100 parts by weight of chloroprene rubber. The chloroprene composition according to claim 1, further comprising at least one selected from the group consisting of a thiuram vulcanization accelerator, a guanidine vulcanization accelerator, a thiazole vulcanization accelerator, and a sulfenamide vulcanization accelerator. A chloroprene rubber composition comprising 0.1 to 5 parts by weight of a compound. The amine salt of dithiocarbamic acid is an amine salt of at least one dithiocarbamic acid selected from the group consisting of piperidinium pentamethylenedithiocarbamate, diethylammonium diethyldithiocarbamate, pipecolinium pipecolyldithiocarbamate, and pyrrolidine-ammonium dithiocarbamate. The chloroprene rubber composition according to claim 1 or 2. A vulcanized product obtained by vulcanizing the chloroprene rubber composition according to any one of claims 1 to 3.