CN114907628A

CN114907628A - Rubber composition for abrasion-resistant tire

Info

Publication number: CN114907628A
Application number: CN202210471966.8A
Authority: CN
Inventors: 王�锋; 韩海光; 吴晨静; 何子锋; 马勇; 吕建强; 陈雪梅; 魏胜; 聂秋海; 李宇石
Original assignee: Beijing Linglong Tyre Co ltd; Shandong Linglong Tyre Co Ltd
Current assignee: Beijing Linglong Tyre Co ltd; Shandong Linglong Tyre Co Ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-08-16

Abstract

The invention belongs to the technical field of tires and discloses a rubber composition for a wear-resistant tire, which comprises 10-50 phr of polyisoprene rubber, 10-50 phr of polybutadiene rubber, 10-50 phr of butadiene-styrene copolymer, 5-25 phr of the same 1, 2 polybutadiene, 10-30 phr of carbon black and 40-100 phr of white carbon black. The rubber composition of the invention can effectively improve the wear resistance of the tire and reduce the rolling resistance.

Description

Rubber composition for abrasion-resistant tire

Technical Field

The invention relates to the technical field of tires, in particular to a rubber composition for a wear-resistant tire.

Background

At present, the policy and measures proposed in China require that the tire further improve the endurance performance and the low rolling resistance performance and reduce the energy consumption.

The wear properties of rubber compounds are very important properties, especially in the field of tire treads. The conventional method for improving the wear performance of tires is to increase carbon black having a small particle size, but the adverse effect is that the rebound characteristics are reduced with the increase of the amount of carbon black, and the rolling resistance of a tire having a higher rebound resilience is lower because the rolling resistance and the rebound characteristics of a tire are opposite.

In addition, the rubber composition of the tread of the current tire has room for further improvement in the durability of the tire. Solution polymerized styrene butadiene rubber, natural rubber and butadiene rubber are generally used in the raw rubber system. In recent years, the development of SBR rubber technology, particularly the innovation of SSBR technology, has greatly improved the wet skid resistance of tires. In order to ensure the balance of the tire performance of the magic triangle, in order to not reduce the durability of the rubber compound, the molecular weight of SSBR is generally designed to be larger so as to improve the wear resistance of the rubber compound, but the larger molecular weight easily causes higher Mooney viscosity of raw rubber, deteriorates a mixing process and increases the energy consumption of mixing equipment.

Moreover, the conventional tread rubber material of the green tire is generally reinforced by white carbon black, but with the increase of the using amount of the white carbon black, the white carbon black is not well dispersed in the rubber due to the self-aggregation effect, so that the performance of the rubber material is reduced.

Therefore, how to provide a rubber composition capable of improving the abrasion resistance of a tire without losing or reducing the rolling resistance of the tire is a problem to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the present invention provides a rubber composition which is effective in improving the wear resistance of a tire and also effective in reducing the rolling resistance.

In order to achieve the purpose, the invention adopts the following technical scheme:

the rubber composition for abrasion-resistant tires comprises, based on 100 parts by weight of rubber, 10 to 50phr of polyisoprene rubber, 10 to 50phr of polybutadiene rubber, 10 to 50phr of butadiene-styrene copolymer, 5 to 25phr of syndiotactic 1, 2 polybutadiene, 10 to 30phr of carbon black and 40 to 100phr of white carbon black.

Preferably, in the rubber composition for a wear-resistant tire, the syndiotactic 1, 2 polybutadiene has a number average molecular weight of 200000-500000, a Tg point of-10-10 ℃, a melting point of 130-150 ℃ and a crystallinity of 10-30%.

Preferably, in the above rubber composition for a wear-resistant tire, the syndiotactic 1, 2 polybutadiene comprises a monomer of 1, 2-butadiene, an iron-based complex catalyst and water as a dispersion medium.

Preferably, in the rubber composition for a wear-resistant tire, the iron-based complex catalyst is prepared by pre-aging four components of an organic iron compound, an alkyl aluminum compound, a dialkyl hydrogen phosphite compound and butadiene for aging.

The syndiotactic 1, 2 polybutadiene in the invention is used as a novel reinforcing agent to improve the performance of rubber, and simultaneously has the characteristics of reducing the abrasion of the rubber, improving the wear resistance, reducing the heat generation and improving the rolling resistance.

Preferably, in the rubber composition for a wear-resistant tire, the polyisoprene rubber is cis 1, 4-polyisoprene rubber.

Preferably, in the rubber composition for a wear-resistant tire described above, the polybutadiene rubber is a high cis synthetic rubber having a cis content of > 96%.

Preferably, in the rubber composition for a wear-resistant tire, the butadiene-styrene copolymer has a vinyl content of 10 to 60% and a styrene content of 10 to 40%.

Preferably, in the rubber composition for a wear-resistant tire, the carbon black has a nitrogen adsorption specific surface area of 120m ² More than g, the DBP oil absorption value is 120cm ³ More than 100 g.

Preferably, in the rubber composition for a wear-resistant tire, the white carbon has a BET specific surface area of 100m ² More than g, the DBP oil absorption value is 1.0cm ³ More than g.

The mixing of the rubber composition can be accomplished by methods known to those skilled in the art of rubber mixing, such as, in the usual case, mixing the components in at least two stages, at least one non-productive mixing stage, followed by a productive mixing stage, the rubber being mixed with the polymer resin in one or more non-productive mixing stages.

According to the technical scheme, compared with the prior art, the invention discloses a rubber composition for a wear-resistant tire, which has the following advantages:

the syndiotactic 1, 2 polybutadiene is used as a novel reinforcing agent to improve the performance of rubber materials, has large molecular weight and crystallization characteristic, improves the physical crosslinking of the rubber materials, ensures the strength of the rubber materials, improves the wear resistance of the rubber materials, and can improve the heat generation of the rubber materials so as to improve the fuel consumption.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The rubber compositions having the composition as specified in Table 1 were prepared in a BR Banbury mixer using two separate feed mixing stages, a non-productive mixing stage and a productive mixing stage. The non-productive stage is carried out for about 2-3 min until the rubber temperature reaches 160 ℃, and the mixing time of the productive stage is the time for enabling the rubber temperature to reach 100 ℃.

The rubber compositions are referred to herein as sample a, sample b, and sample c. Sample a is considered here as a control, i.e. no optimized filler amount is used in the filler system.

TABLE 1 rubber composition ratio

In Table 1, the syndiotactic 1, 2 polybutadiene has a number average molecular weight of 200000-500000, a Tg point of-10-10 ℃, a melting point of 130-150 ℃ and a crystallinity of 10-30%, and comprises a monomer 1, 2-butadiene, an iron-based coordination catalyst prepared by pre-aging four components of an organic iron compound, an alkyl aluminum compound, a hydrogen phosphite dialkyl ester compound and butadiene for aging, and water serving as a dispersion medium; the polyisoprene rubber is cis 1, 4-polyisoprene rubber; polybutadiene rubber is a synthetic rubber with a cis content of > 96%; the vinyl content of the butadiene-styrene copolymer is 10-60%, and the styrene content is 10-40%; the nitrogen adsorption specific surface area of the carbon black was 120m ² More than g, the DBP oil absorption value is 120cm ³ More than 100 g; the BET specific surface area of the white carbon black is 100m ² More than g, the DBP oil absorption value is 1.0cm ³ More than g.

All samples were vulcanized at 151 ℃ for about 30min, and Table 2 shows the physical properties of the vulcanized samples a, b, and c, wherein the measured values of the respective physical indices of the composition of the sample a were regarded as 100 as the basis.

TABLE 2 physical Properties

Vulcanizing at 151 ℃ for 30min	Sample a	Sample b	Sample c
				Hardness of	100	104	111
Stress at 100% definite elongation	100	129	148
				Stress at definite elongation of 300%	100	119	135
Tensile strength	100	101	108
				Elongation at break	100	88	88
Din abrasion	100	130	153
				tanδ0℃	100	95	80
tanδ60℃	100	85	87

As can be seen from example 1, by adding syndiotactic 1, 2 polybutadiene to the rubber composition, the Din abrasion and rolling resistance of the compound increased significantly, demonstrating the above characteristics, but the wet skid resistance decreased more.

Example 2

The rubber compositions having the compositions specified in Table 3 were prepared in a BR Banbury mixer using two separate feed mixing stages, namely a non-productive mixing stage and a productive mixing stage. The non-productive stage is carried out for about 2-3 min until the rubber temperature reaches 160 ℃, and the mixing time of the productive stage is the time for enabling the rubber temperature to reach 100 ℃.

The rubber compositions are referred to herein as sample a, sample d, where sample a is referred to herein as a control, i.e., no optimized rubber formulation is used in the rubber composition.

TABLE 3 rubber composition compounding ratio

In Table 3, syndiotactic 1, 2 polybutadiene having a number average molecular weight of 200000-500000, a Tg of-10-10 ℃, a melting point of 130-150 ℃ and a crystallinity of 10-30% comprises a monomer of 1, 2-butadiene, an iron-based coordination catalyst prepared by pre-aging an organic iron compound, an alkylaluminum compound, a hydrogen phosphite dialkyl ester compound and butadiene for aging, and water as a dispersion medium; the polyisoprene rubber is cis 1, 4-polyisoprene rubber; polybutadiene rubber is a synthetic rubber with a cis content of more than 96%; the vinyl content of the butadiene-styrene copolymer is 10-60%, and the styrene content is 10-40%; the nitrogen adsorption specific surface area of the carbon black was 120m ² More than g, the DBP oil absorption value is 120cm ³ More than 100 g; the BET specific surface area of the white carbon black is 100m ² More than g, DBP oil absorption value of 1.0cm ³ More than g.

All samples were cured at 151 ℃ for about 30min and the physical properties of the cured samples a, d are given in table 4, where the values obtained for the composition of sample a are taken as a base to be exactly 100.

TABLE 4 physical Properties

The results of example 2 show that the use of a syndiotactic 1, 2 polybutadiene rubber composition increases the Din abrasion of the rubber compound, improves tire durability, and improves fuel economy.

Hardness, modulus, tan delta at 60 ℃ may be carried out according to test method GB/T531.1 which is acceptable to the tire industry. The lower the tan delta value at 60 ℃ means the lower the heat generation of the compound; the higher the tan ℃ at 0 ℃, the better the tire wet skid resistance.

In the invention, the use of syndiotactic 1, 2 polybutadiene is considered as an important factor for reducing rubber material heat generation, the syndiotactic 1, 2 polybutadiene has a large molecular weight and a crystallization characteristic, the physical crosslinking of rubber material is promoted, the strength of the rubber material is ensured, and the wear resistance of the rubber material is improved; meanwhile, the heat generation of the rubber compound can be improved, so that the fuel consumption is improved.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the scheme disclosed by the embodiment, the scheme corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rubber composition for abrasion-resistant tires, characterized by comprising 10 to 50phr of a polyisoprene rubber, 10 to 50phr of a polybutadiene rubber, 10 to 50phr of a butadiene-styrene copolymer, 5 to 25phr of a syndiotactic 1, 2 polybutadiene, 10 to 30phr of a carbon black, and 40 to 100phr of a white carbon black.

2. The rubber composition for a wear-resistant tire as claimed in claim 1, wherein the syndiotactic 1, 2 polybutadiene has a number average molecular weight of 200000-.

3. The rubber composition for abrasion resistant tires according to claim 1 or 2, characterized in that the syndiotactic 1, 2 polybutadiene comprises monomeric 1, 2-butadiene, an iron-based coordination catalyst and water as a dispersion medium.

4. The rubber composition for abrasion-resistant tires according to claim 3, wherein the iron-based complex catalyst is prepared by pre-aging four components of organic iron compound, alkyl aluminum compound, dialkyl hydrogen phosphite compound and butadiene for aging.

5. The rubber composition for a wear-resistant tire according to claim 1, wherein the polyisoprene rubber is cis 1, 4-polyisoprene rubber.

6. The rubber composition for abrasion-resistant tires according to claim 1, characterized in that the polybutadiene rubber is a synthetic rubber with a cis content > 96%.

7. The rubber composition for a wear-resistant tire according to claim 1, wherein the butadiene-styrene copolymer has a vinyl content of 10 to 60% and a styrene content of 10 to 40%.

8. The rubber composition for abrasion-resistant tires according to claim 1, wherein the carbon black has a nitrogen adsorption specific surface area of 120m ² More than g, the DBP oil absorption value is 120cm ³ More than 100 g.

9. The rubber composition for abrasion-resistant tires according to claim 1, characterized in that the white carbon black has a BET specific surface area of 100m ² More than g, DBP oil absorption value of 1.0cm ³ More than g.

10. The rubber composition for a wear-resistant tire according to claim 1, further comprising a silane coupling agent, a process oil, an antioxidant, microcrystalline wax, stearic acid, zinc oxide, sulfur, and an accelerator.