JPH0260949A - Stabilized composition of vulcanization accelerator for rubber - Google Patents

Abstract

PURPOSE:To prevent or restrain a vulcanization accelerator from forming a free amine due to degradation when exposed to severe conditions of high temperature and high humidity by adding a specified compound to a benzothiazolyl- sulfenamide vulcanization accelerator. CONSTITUTION:0.1-2.0wt.% at least one compound selected from among compounds of formulas II-V [wherein R3 is H or a 1-9 C alkyl; R4 is H, a 1-6 C alkyl, a cycloalkyl, an amino, an alkoxy or a (halogen-substituted) aryl; R5 is H or methyl; R6 is H, a 1-8C alkyl, an aralkyl, a phenyl or an amino; X is -O-, -NH-; R7 is methyl, phenyl, gamma-methacryloxypropyl or the like; m is 3-12; y is 3-7; and a is 1 or 2], dibutyltin carboxylates, and isocyanate compounds is added to a benzothiazolylsulfenamide vulcanization accelerator of formula I (wherein R1-2 are each H, a 1-8 C alkyl, a 5-6 C cycloalkyl, or R1 and R2 may be alkylenes or oxyalkylenes which are combined together to form a heterocyclic ring containing an N atom; and n is 1 or 2, provided that the case in which both R1 and R2 are hydrogen atoms at the same time is excluded).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a composition for stabilizing a benzothiazolylsulfenamide vulcanization accelerator for rubber.

(Prior art and problems to be solved by the invention) Benzothiazolylsulfenamide vulcanization accelerator (hereinafter abbreviated as rBsAJ) is a rubber vulcanization accelerator widely used in the rubber industry. be. Although this compound is easily produced in a highly pure state by well-known methods, it degrades when exposed to high temperature and/or high humidity conditions with the gradual formation of dibenzothiazyl disulfide (MBTS) and free amines. It has been known. Regarding this BSA deterioration, specifically, J. J. LUECKEN and A.
.

B, 5ULLIVAN: ELASTOMERIC8,
It is described in detail on page 34 of AUGtJsT (1981), including the following reaction formula (1).

Sulfenamide dibenzothiazyl disulfite (MBTS) "MBT sulfonic acid free amine" MBT: 2-mercaptobenzothiazole,
Since high temperatures and humid conditions are common during the summer months and in temperate regions of the world, it would be desirable to find a means to prevent or slow this degradation of BSA and thus inhibit the formation of free amines. As a method for preventing or delaying this deterioration, a method using an oxirane compound as a stabilizer was published in Japanese Patent Application Laid-open No. 54
It is proposed in the -19975 publication. However, with this method, it is not possible to sufficiently prevent or delay the generation of amine odor resulting from the "fi-released amines" that occur when BSA deteriorates. Not only does this significantly impair the properties of the rubber, but also the processing stability of unvulcanized rubber kneaded with this product is not fully satisfied.

However, no SA stabilizing composition has yet been found that can sufficiently prevent or delay the deterioration of BSA accompanied by the generation of ti-released amines under industrial storage and use conditions. Needless to say, finding a composition is extremely meaningful industrially.

(Means for Solving the Problems) As a result of intensive research in order to overcome the current situation, the present inventors found that - Noshiro [I] BSA is represented by - Noshiro [II] to [V]. When one or more selected from the group of compounds such as dibutyltin carboxylate compounds, dibutyltin carboxylate compounds, and isocyanate compounds are added, BSA containing free amines can be dissolved even after long-term storage under harsh conditions at high temperature and high humidity. It has been discovered that deterioration can be prevented or delayed, and the above-mentioned problems that are currently hindrances in industry can be solved, leading to the completion of the present invention.

(In the formula, R+, R2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group having 5 to 6 carbon atoms, or an alkylene group in which R+, R2 is combined with a nitrogen atom to form a heterocycle. , represents an oxyalkylene group. n represents an integer of 1 or 2. However, R1 and R2 are not hydrogen atoms at the same time.) (CH2)m-CHR3 (wherein, R3 is a hydrogen atom, a carbon atom 1 to 9 alkyl groups, and m represents an integer of 2 to 13. An aryl group which may be substituted with halogen, y represents an integer of 3 to 7. (In the formula, R5 is a hydrogen atom, a methyl group, R6 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, An aralkyl group, a phenyl group, an amino group, and X represents 10- or -NH-.

) (R7)a -3i -(OR8)4-a [V]
(In the formula, R7 is a methyl group, phenyl group, vinyl group, γ-
methacryloxypropyl group, β-(3,4 epoxycyclohexyl)ethyl group, γ-glycidoxypropyl group,
N-β-(aminoethyl)γ-aminopropyl group, γ-
Aminopropyl group, N-phenyl-T-aminopropyl group, γ-mercaptopropyl group, γ-chloropropyl group, R8 is a methyl group, ethyl group, β-methoxyethyl group, a is an integer of 1 or 2. show. ) Hereinafter, embodiments of the present invention will be described.

The lactone derivatives of Ichinoshiro Um according to the present invention include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, γ-hexalactone, γ-heptalactone, γ-nonalactone, δ-nonalactone,
Examples include, but are not limited to, δ-decalactone, γ-undecalactone, γ-dodecalactone, δ-dodecalactone, δ-tetradecalactone, 15-pentadecalactone, and the like.

The lactam derivatives of general formula [1] according to the present invention include 2-pyrrolidone, N-methyl-2-pyrrolidone, 5-methyl-
2-pyrrolidone, 2-piperidone, N-ethyl-2-pyrrolidone, N-methyl-4piperidone, ε-caprolactam, ω-hebutalactam, N-methyl-ε-caprolactam, ω-octalactam, N-n-butyl- 2-pyrrolidone, N-phenyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-0~tolyl-2-pyrrolidone, N-m-1 heli-2-pyrrolidone, N-p-tolyl-2- Pyrrolidone, N-tolyl-2-pyrrolidone, N
-2-3-1dimethylphenyl-2-pyrrolidone, N-
2',4''-dimethylphenyl-2-pyrrolidone, N-
2=5-dimethylphenyl-2-pyrrolidone, N-
2'6'-dimethylphenyl-2-pyrrolidone, N-3
=, 4-dimethylphenyl-2-pyrrolidone, N-3
”5-dimethylphenyl-2-pyrrolidone, N-
xylyl-2-pyrrolidone, N-o-ethylphenyl-
2-pyrrolidone, N-m-ethylphenyl-2-pyrrolidone, N-p-ethylphenyl-2-pyrrolidone, N-
D-n-propylphenyl-2-pyrrolidone, N-p-
n-butylphenyl-2-pyrrolidone, N-on-pentylphenyl-2-pyrrolidone, N-p-n-hexylphenyl-2-pyrrolidone, N-D-n-hebutylphenyl-2-pyrrolidone, N -p-n-octylphenyl-2-pyrrolidone, N-pN-, N'''-dimethylaminophenyl-2-pyrrolidone, N-D-N-N''-
Diethylaminophyl-2-pyrrolidone, N-p-N
”-Methylaminophenyl-2-pyrrolidone, N-p
-N-cyclohexylaminophenyl-2-pyrrolidone, N-p-7nilinophenyl-2-pyrrolidone, N-p
-N”-tolylaminophenyl-2-pyrrolidone, N-
o-chlorophenyl-2-pyrrolidone, N-m-chlorophenyl-2-pyrrolidone, N-p-chlorophenyl-
2-pyrrolidone, N-0-bromophenyl-2-pyrrolidone, N-m-bromophenyl-2-pyrrolidone, N-
Examples include, but are not limited to, p-bromophenyl-2-pyrrolidone, N-D-methoxyphenyl-2-pyrrolidone, N-p-ethoxyphenyl-2-pyrrolidone, and the like.

The sulfone compound of general formula [1v] according to the present invention includes benzenesulfonic acid amide, benzenesulfonic acid anilide,
Benzenesulfonic acid hydrazide, methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, N-n-butylbenzenesulfonamide, N
-Methylbenzenesulfonic acid amide, 0-toluenesulfonic acid amide, p-toluenesulfonic acid amide, p-toluenesulfonic acid anilide, methyl p-toluenesulfonate, edyl p-toluenesulfonate, propyl p-toluenesulfonate, p -butyl toluenesulfonate, p
-hexyl toluenesulfonate, heptyl D-toluenesulfonate, octyl p-toluenesulfonate, phenethyl p-toluenesulfonate, phenyl p-toluenesulfonate, N.

N-diethyl-p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, N-butyl-p
Examples include, but are not limited to, -toluenesulfonic acid amide, p-toluenesulfonic acid hydrazide, and the like.

The silyl compound of general formula [V] according to the present invention includes trimethoxymethylsilane, trimethoxyphenylsilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, trimethoxyvinylsilane, trimethoxymethacryloxypropylsilane, β-(3,4-
epoxycyclohexyl)ethyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyljethoxysilane, Nβ-(
aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-7minoethyl)-T-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-7minopropyltrimethoxysilane, Examples include, but are not limited to, γ-mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

The butyltin carboxylate compound according to the present invention is a di-
Examples include, but are not limited to, n-butyltin diacetate, di-n-butyltin dilaurate, di-n-butyltin maleate, di-n-butyltin maleate polymer, di-n-butyltin oxide, etc. It's not a thing.

The isocyanate compound according to the present invention includes toluylene diisocyanate, phenyl isocyanate, bipod of 2,4-toluylene diisocyanate, naphthalene-1,5
-diisocyanate, 〇-tolylene diisocyanate,
diphenylmethane diisocyanate, triphenylmethane triisocyanate, tris(p-isocyanatophenyl) thiophosphite, polymethylene polyphenylisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, Examples include, but are not limited to, xylylene diisocyanate.

-Lactone derivative of Noshiro [II], -lactam derivative of Noshiro [In], -sulfone compound of Noshiro [■v], -silyl compound of Noshiro [V], dibutyltin carboxylate compound and isocyanate compound according to the present invention The amount added to one or more BSA selected from the group of
It ranges from 0.1 to 2.0% by weight, preferably from 0.2 to 1.5% by weight, based on the weight of BSA.

If the addition interval is less than 0.1% by weight, the stabilizing effect will be poor,
However, if it exceeds 2.0% by weight, it is not preferable because it will greatly affect the physical properties of BSA, such as the melting point.

Further, the method of addition means mixing by any conventional method not inconsistent with the present invention. As an example of the addition method, - Noshiro [II
] Lactone derivatives of -Noshiro [I11], -Noshiro [I11] lactam derivatives, -Noshiro [IV] sulfone compounds, -Noshiro [V] silyl compounds, dibutyltin carboxylate compounds, and isocyanate compounds. A method of directly mixing two or more species can be mentioned.

- Lactone derivatives of Noshiro [II], - lactam derivatives of Noshiro [I11], - sulfone compounds of Noshiro [1v], - silyl compounds, dibutyltin carboxylate compounds and isocyanate compounds of Noshiro [V] according to the present invention. The BSA to be mixed is listed below, but is not limited to these.

Namely, N,N-diethyl-2-benzothiazolylsulfenamide, N-cyclohexyl-2-benzothiazolylsulfenamide, N-t-butyl-2-benzothiazolylsulfenamide, N-oxydiethylene-
2-Benzothiazolylsulfenamide, N,N-diisopropyl 2-benzothiazolylsulfenamide, N
, Ndicyclohexyl-2-benzothiazolylsulfenamide, 2-(4''-morpholinodithio)benzothiazole, Nt-octyl-2-benzothiazolylsulfenamide, and the like.

Stabilization, as defined for the purposes of the present invention, refers to any significant improvement in the stability of BSA after prolonged storage at ambient or higher temperatures.

(Effects of the Invention) As detailed above, the lactone derivative of the general formula [II] according to the present invention, the lactam derivative of Noshiro [I11], -
One or more selected from the group of sulfone compounds of Noshiro [IV], silyl compounds of Noshiro [V], dibutyltin carboxylate compounds, and isocyanate compounds are added to BSA with a small amount of ffi[0,1 to 2°0 % by weight], when BSA is exposed to severe conditions of high temperature and high humidity, it prevents or delays the significant generation of free amines associated with deterioration and has almost no effect on the vulcanization performance of BSA.
This made it possible to stabilize the

Hereinafter, the effects of the present invention will be explained with reference to Examples, but the scope of the present invention is not limited to the embodiments described in the Examples.

(Example) Example 1゜ Tsukusela NS (N-t-butyl-
2-Benzothiazolylsulfenamide dry powder 30? The prescribed amounts of the stabilizers listed in J and Table 1 were added to milk, thoroughly mixed with a pestle, placed in a sealed 300Irdl Erlenmeyer flask with a stopcock, and subjected to forced aging at 50°C for 14 days under 65% relative humidity. We conducted a test.

The melting point, MBTS content, and free amine concentration of each mixture before and after the forced deterioration test were measured using the following measuring methods. The results are shown in Table-1.

A. Melting point measurement method J 15K6220-1977 (
The test was carried out in accordance with 6.4 of Test Methods for Rubber Compounds.

B. Measuring method of MBTS content Sample N1N10O was dissolved in chloroform using a 10-volume flask, and measurement was performed by a chromatography scanner method using thin layer chromatography (two-point calibration curve method and external standard method).

Chromato scanner conditions Chromato scanner: vfJ Shimadzu chromato scanner C3930 model. Measurement wavelength = 2 wavelength method [1 wavelength (83): 280 nm, 2 wavelength (input R): 360 nm]. Note that the measurement employed a program scanning method.

Measuring method of C, r1 released amine concentration Using a rubber tube in a sealed 300D Erlenmeyer flask with a stopcock containing the sample, insert the detection tube of an ammonia detector (available from Rikagaku Kogyo (T1% Kitagawa type ammonia detector)). The free amine concentration was measured by directly connecting an ammonia detector tube manufactured by Kakuri Kagaku Kogyo Kan Co., Ltd.

From Table 1, the free amine concentration after the forced deterioration test is lower in the Examples than in the Comparative Examples, and the stabilizing effect of BSA is recognized.

Example 2 (Rubber compounding test) Mixture before and after the forced deterioration test conducted in Example 1 (Table 3
, the "sample" shown in Table 2) was kneaded using a kneading roll machine according to the conventional rubber processing method based on the recipe shown in Table 2, and the unvulcanized rubber of each sample was mixed with J l5K630.
A Mooney scorch test was conducted in accordance with 0-1974 (Physical Test Method for Unvulcanized Rubber). The results are shown in Table 3, Mooney Scorch Test Results.

From Table 3, it can be seen that the Mooney scorch time [ts] (processing stability) after the forced deterioration test did not become faster in the example compared to the comparative example, and the processing stability to BS was maintained.
The stabilizing effect of A is recognized.

Claims (7)

[Claims] (1) The benzothiazolylsulfenamide vulcanization accelerator of general formula [I] is selected from the group of compounds represented by general formulas [II] to [V], dibutyltin carboxylate compounds, and isocyanate compounds. 1. A stabilized composition of a vulcanization accelerator for rubber, characterized in that one or more of these are added. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, R_1 and R_2 are hydrogen atoms, alkyl groups of 1 to 8 carbon atoms, cyclic alkyl groups of 5 to 6 carbon atoms, or R_1 and R_2 are Represents an alkylene group or oxydialkylene group that combines with a nitrogen atom to form a heterocycle.n represents an integer of 1 or 2.However, R_1 and R
_2 cannot be a hydrogen atom at the same time. )▲Formula,
There are chemical formulas, tables, etc. ▼ [II] (In the formula, R_3 represents a hydrogen atom, an alkyl group with 1 to 9 carbon atoms, and m represents an integer from 2 to 13.) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼[III] (wherein R_4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group, an amino group, an alkoxy group,
an aryl group which may be substituted with halogen, and y is 3 to 7;
indicates an integer. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [IV] (In the formula, R_5 is a hydrogen atom or a methyl group, R_6 is a hydrogen atom, an alkyl group with 1 to 8 carbon atoms, an aralkyl group,
A phenyl group or an amino group, and X represents -O- or -NH-. ) (R_7)_a-Si-(OR_8)_4_-_a[V
] (In the formula, R_7 is a methyl group, a phenyl group, a vinyl group,
γ-methacryloxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group, γ-glycidoxypropyl group, N-β-(aminoethyl)-γ-aminopropyl group, γ-aminopropyl group, N -Phenyl-γ-aminopropyl group, γ-mercaptopropyl group, γ-chloropropyl group, R_8 represents a methyl group, ethyl group, β-methoxyethyl group, and a represents an integer of 1 or 2. ) (2) The benzothiazolylsulfenamide vulcanization accelerator represented by the general formula [I] is N-cyclohexyl-2-
The composition according to claim (1), which is benzothiazolylsulfenamide, N-t-butyl-2-benzothiazolylsulfenamide, or N-oxydiethylene-2-benzothiazolylsulfenamide . (3) The composition according to claim (1), wherein the lactone derivative represented by general formula [II] is γ-butyrolactone, δ-valerolactone, or ε-caprolactone. (4) The lactam derivative represented by the general formula [III] is 2-
The composition according to claim 1, which is pyrrolidone, N-phenyl-2-pyrrolidone, and ε-caprolactam. (5) The sulfonic acid compound represented by the general formula [IV] is P-
The composition according to claim (1), which is methyl toluenesulfonate, ethyl p-toluenesulfonate, or methyl benzenesulfonate. (6) The dibutyltin carboxylate compound is di-n-butyltin diacetate, di-n-butyltin dilaurate,
The composition according to claim 1, which is di-n-butyltin maleate, di-n-butyltin maleate polymer, or di-n-butyltin oxide. (7) The isocyanate compound is toluylene diisocyanate, naphthalene-1,5-diisocyanate, diphenylmethane diisocyanate (
The composition described in item 1).