CN-121991419-A - Rubber composition for tire steel wire belt and preparation method thereof

Abstract

The invention belongs to the field of rubber materials, and provides a rubber composition for a steel wire belt layer of a tire and a preparation method thereof, wherein the formula composition of the rubber composition comprises 70-90 parts of natural rubber, 20-40 parts of epoxidized natural rubber, 5-7 parts of tackifying system, 50-65 parts of carbon black, 2-5 parts of anti-aging agent and 4-6 parts of sulfur system, the tackifying system is prepared by reacting benzimidazole, thiuram compounds and omega-bromo fatty acid benzyl ester, and the omega-bromo fatty acid benzyl ester is prepared by nucleophilic substitution reaction of omega-bromo fatty acid and benzyl bromide. According to the invention, benzimidazole and thiuram compounds are bridged through flexible fatty chains to form a tackifying system molecule, the molecule can be chelated with metal ions such as copper/zinc/iron and the like on the surface of the steel wire through a benzimidazole part, so that the initial adhesive strength between rubber and the steel wire is improved, the stress distribution of the interface between the steel wire belt rubber and the steel wire is improved through the thiuram part, and the adhesive property of a steel wire ply is improved.

Inventors

• ZHANG YULIANG
• YANG ZHENGUO
• Xie Haisu
• ZHAO RUIQING
• CHEN JIANJUN
• WANG YEJING
• XIAO SHENGLONG
• Xie Xiaohou
• WANG LING

Assignees

• 山东华盛橡胶有限公司
• 山东宏盛橡胶科技有限公司

Dates

Publication Date

20260508

Application Date

20260409

Claims (10)

1. 1. The rubber composition for the steel wire belt layer of the tire is characterized by comprising 70-90 parts of natural rubber, 20-40 parts of epoxidized natural rubber, 5-7 parts of tackifying system, 50-65 parts of carbon black, 2-5 parts of anti-aging agent and 4-6 parts of sulfur system; the anti-aging agent is an amine anti-aging agent; the sulfur system is sulfur and an accelerator; the accelerator is thiazole accelerator or sulfenamide accelerator; the amine anti-aging agent is N- (1, 3-dimethylbutyl) -N ' -phenyl-p-phenylenediamine, N- (1, 4-dimethylpentyl) -N ' -phenyl-p-phenylenediamine, N ' -bis (1, 4-dimethylpentyl) -p-phenylenediamine; the thiazole accelerant comprises at least one of 2-mercaptobenzothiazole and dibenzothiazyl disulfide, and the sulfenamide accelerant comprises at least one of N-cyclohexyl-2-benzothiazole sulfenamide and N-tertiary butyl-2-benzothiazole sulfenamide; The structure of the tackifying system is shown in a formula I, I is a kind of Wherein R 1 、R 2 is C1-C8 alkyl, substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl or R 1 、R 2 forms cycloalkyl or substituted cycloalkyl, respectively; r 3 is C3-C18 alkanyl.
2. 2. A rubber composition for a tire tread belt according to claim 1, wherein the raw materials for synthesizing the tackifying system comprise benzimidazole, thiuram type compounds, ω -brominated fatty acid benzyl esters, and the raw materials for synthesizing the ω -brominated fatty acid benzyl esters comprise ω -brominated fatty acids and benzyl bromide.
3. 3. A rubber composition for a steel belt for tires according to claim 2, characterized in that said omega-brominated fatty acid has the general formula Br-R 3 -COOH, wherein R 3 is a C3-C8 alkanyl group.
4. 4. A rubber composition for a tire steel belt according to claim 2, wherein said thiuram-based compound is selected from at least one of tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide, sodium N, N' -dimethyldithiocarbamate.
5. 5. A rubber composition for a tire steel belt according to claim 1, wherein R 1 is methyl, R 2 is methyl, and R 3 is C5 chain alkyl.
6. 6. A rubber composition for a tire steel belt according to claim 2, wherein the raw materials for synthesizing ω -brominated fatty acid benzyl ester further comprise potassium carbonate, and the ω -brominated fatty acid, benzyl bromide and potassium carbonate are in a molar ratio of 1:1.1-1.2:1.5-2.
7. 7. A method for producing a rubber composition for a tire steel belt according to any one of claims 1 to 6, characterized in that a natural rubber and an epoxidized natural rubber are subjected to open milling and then to kneading, and carbon black, an antioxidant, a sulfur system and a tackifying system are added during the kneading, and the rubber composition for a tire steel belt is obtained by vulcanization after the kneading.
8. 8. The method for producing a rubber composition for a tire steel belt according to claim 7, wherein the method for producing a tackifying system comprises the steps of: S1 benzimidazole and omega-bromo fatty acid benzyl ester are subjected to N-alkylation reaction to obtain 6- (2-benzimidazolyl) fatty acid benzyl ester, S2 6- (2-benzimidazolyl) fatty acid benzyl ester and thiuram compounds are subjected to nucleophilic acyl substitution reaction to obtain a tackifying system.
9. 9. The method for producing a rubber composition for a tire steel belt according to claim 7, wherein the kneading process comprises a one-stage kneading in which carbon black and an anti-aging agent are added and a two-stage kneading in which a sulfur system and a tackifier system are added.
10. 10. The method for producing a rubber composition for a steel belt layer for a tire according to claim 9, wherein the rubber discharge temperature is controlled to be 155 to 165 ℃ by one-stage kneading and 105 to 115 ℃ by two-stage kneading.

Description

Rubber composition for tire steel wire belt and preparation method thereof Technical Field The invention relates to the field of rubber materials, in particular to a rubber composition for a steel wire belt layer of a tire and a preparation method thereof. Background The radial tire is a tire widely used in the current automobile tire, has higher performance requirement, is a composite material rubber product with a very complex structure, and adopts a steel cord as a framework material in the steel belt layer part inside the semisteel radial tire. The rubber composition for the steel belt layer is required to have excellent processability, high modulus, low heat generation and the like on the one hand, and good interfacial adhesion property with the copper-plated steel cord on the other hand, so as to prevent the problems of delamination of the steel wire from the rubber, fatigue failure and the like during use, thereby ensuring the safety and the service life of the tire. In the prior art, for improving the adhesion performance of rubber and copper-plated steel wires, an inter-alpha-formaldehyde adhesive and white carbon black are adopted as an inter-alpha-formaldehyde white adhesive system in the invention patent with publication number CN 113861886A. Although the system can provide better initial adhesive force and adhesive retention rate after aging, the system has the obvious defects that resorcinol has a lower melting point, is easy to sublimate in the high-temperature mixing process, releases toxic and strong-irritation smoke, causes serious harm to respiratory systems and skins of operators and simultaneously causes environmental pollution, and the hexamethylene tetramine is used as a formaldehyde release agent, has strong irritation to the skins, is difficult to disperse during mixing, is easy to cause a frosting phenomenon, and formaldehyde derivatives are identified as cancerogenic substances and mutagenic substances by international regulations, so that the system does not meet the environment-friendly requirements of modern tire industry. In addition, the system has a narrow processing window, and is easy to cause negative effects such as shortened scorching time, uneven vulcanization, reduced processing safety and the like. The existing alternative scheme is as the invention patent with publication number CN108314806A, through adding modifiers such as hexamethylene-1, 6-dithiosulfuric acid disodium salt, the extraction value of the steel wire can be improved to a certain extent after hot air aging, but the initial adhesive strength and the adhesive hardness are not improved basically, and the adhesive performance is improved only to a limited extent. In general, the existing tire steel wire belt rubber composition is widely faced with the problems of great health hazard, serious environmental pollution, poor processing performance, difficulty in balancing comprehensive physical properties and the like while realizing efficient adhesion, and development of a rubber composition for a tire steel wire belt is needed to meet the requirement of performance optimization. Further improvements and developments are therefore needed. Disclosure of Invention In order to solve the above problems, a rubber composition for a steel belt of a tire and a preparation method thereof are provided, and the following technical scheme is provided: The formula of the rubber composition for the steel wire belt layer of the tire comprises 70-90 parts of natural rubber, 20-40 parts of epoxidized natural rubber, 5-7 parts of tackifying system, 50-65 parts of carbon black, 2-5 parts of anti-aging agent and 4-6 parts of sulfur system; the anti-aging agent is an amine anti-aging agent; the sulfur system is sulfur and an accelerator; The structure of the tackifying system is shown in a formula I, I is a kind of Wherein R 1、R2 is C1-C8 alkyl, substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl or R1, R2 form cycloalkyl or substituted cycloalkyl respectively; r 3 is C3-C18 alkanyl. Specifically, the amine antioxidant is N- (1, 3-dimethylbutyl) -N ' -phenyl-p-phenylenediamine (6 PPD), N- (1, 4-dimethylpentyl) -N ' -phenyl-p-phenylenediamine (7 PPD) and N, N ' -bis (1, 4-dimethylpentyl) -p-phenylenediamine (77 PD). Further, the accelerator is a thiazole accelerator or a sulfenamide accelerator; Specifically, the thiazole-based accelerator comprises at least one of 2-mercaptobenzothiazole (accelerator M) and dibenzothiazyl disulfide (accelerator DM), and the sulfenamide-based accelerator comprises at least one of N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and N-tert-butyl-2-benzothiazole sulfenamide (TBBS). Further, the degree of epoxidation of the epoxidized natural rubber is 25%. The raw materials of the synthetic tackifying system comprise benzimidazole, thiuram compounds and omega-bromo fatty acid benzyl ester, and the raw materials of the synthetic omega-bromo fatty acid benzyl ester comprise omega