JPH059339A - Improved rubber compositon - Google Patents

Abstract

PURPOSE:To obtain the title composition capable of improving workability in a plant by lowering viscosity even when viscosity is increased in blend of a natural rubber with a highly reinforcing carbon black and reduced in deterioration of performance by blending the natural rubber, etc., with an amine compound in a specific amount. CONSTITUTION:The objective composition obtained by blending 100 pts.wt. natural rubber and/or synthetic rubber with 0.1-5 pts.wt. (preferably 0.5-3 pts. wt.) amine compound (preferably N-hydroxyethyl-N-2-hydroxydodecylamine) expressed by the formula (R1 is 2-20C alkyl; X is 0-5; y is 1-5) and reinforcing filler, process oil etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rubber composition containing a specific amine compound. More specifically, it relates to a rubber composition in which the workability and the heat aging property after vulcanization are simultaneously improved by blending a specific amine compound.

[0002]

2. Description of the Related Art In recent years, the demands on automobile tires have been diversified, and the demand level has been increasing more and more due to the demands for fuel saving, high exercise performance, long life, and improved appearance.

Among them, particularly in the case of large tires for trucks and buses, the demands for durability such as high wear resistance and high load resistance are still high from the viewpoint of energy saving and economical efficiency,
In order to satisfy these characteristics, it is necessary to significantly improve the wear resistance and fracture resistance of the rubber composition constituting the tire, and the use of highly reinforced carbon black has been increasing.

Also in passenger car tires, as a measure against global warming, there is a growing demand for fuel saving by weight reduction in order to reduce carbon dioxide, and in order to reduce the weight, it is particularly necessary to improve the durability of tire case members. This is an essential requirement, and high-reinforcing carbon black is being used here as well.

However, the use of such a high-reinforcing carbon black remarkably increases the viscosity of the rubber composition when unvulcanized, and puts a great burden on the extruding work and calendering work after kneading. Conventionally, it is generally used after a large amount of a peptizer or a process oil, which is a mastication accelerator that gives plasticity to rubber quickly, is used, or by kneading many times to reduce the viscosity to an appropriate level. However, these methods have drawbacks that physical properties after vulcanization are deteriorated and that repeated kneading is not preferable from the viewpoint of productivity reduction and energy saving.

On the other hand, since rubber products such as tires are used for a long time under dynamic conditions, they are deteriorated by heat and oxygen,
It often happens that the product breaks down during use. Therefore, P represented by N-phenyl-N '-(1,3-dimethylbutyl) -P-phenylenediamine (6C) is generally used.
-A phenylenediamine type anti-aging agent is used, but such an anti-aging agent also has an action of promoting heat curing and cannot be used in a large amount.

Thus, up to now, workability has been improved to improve productivity, achieve energy saving, and maintain a very high level of durability from the beginning to the end of use of the tire. The fact is that a rubber composition that can be obtained has not been obtained yet.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to increase the use of highly reinforced carbon black in order to significantly improve the wear resistance and fracture resistance of a rubber composition, and to reduce the weight by reducing the weight. Even if the use of highly reinforced carbon black is increased to improve the durability of tire case members with the aim of improving fuel efficiency, physical properties after vulcanization are not deteriorated, and deterioration of kneading productivity is prevented, An object of the present invention is to provide a rubber composition which achieves energy saving and on the other hand has little deterioration in physical properties of a tire after heat aging.

[0009]

As a result of intensive studies to solve the above-mentioned problems, the present inventor has used it in the field of antistatic properties of synthetic resins and the like, but used it in rubber compositions. The present invention has been completed by finding that the problem can be solved by blending a specific amine compound that does not exist.

That is, the present invention is at least one compound represented by the following general formula based on 100 parts by weight of natural rubber and / or synthetic rubber.

[Chemical 2] An improved rubber composition comprising 0.1 to 5 parts by weight of an amine compound.

The present invention will be described in detail below. The amine compound which is a compounding compound in the present invention is represented by the general formula 2, R ₁ is an alkyl group having 2 to 20 carbon atoms, and x is 0.
Is an integer of 5 and y is an integer of 1 to 5, for example, N-hydroxyethyl-N-2-hydroxybutylamine, N-hydroxyethyl-N-2-hydroxyoctylamine,
N-hydroxyethyl-N-2-hydroxyethylamine, N-hydroxyethyl-N-2-hydroxydodecylamine, N-hydroxyethyl-N-2-hydroxyhexadecylamine, N-hydroxyethyl-N-2-
Hydroxyoctadecylamine, N, N-bis-hydroxyethyl-N-2-hydroxydodecylamine, N,
N-bis-hydroxyethyl-N-2-hydroxytetradecylamine, N, N-bis-hydroxyethyl-N
-2-Hydroxyhexadecylamine, N, N-bis-
Hydroxyethyl-N-2-octadecylamine, N-
Polyoxyethylene-N-2-hydroxydodecylamine, N-polyoxyethylene-N-2-hydroxytetradecylamine, N-polyoxyethylene-N-2-hydroxyhexadecylamine, N-polyoxyethylene-N- 2-hydroxyoctadecylamine, etc.,

Preferably, N-hydroxyethyl-N-
2-hydroxydodecylamine, N-hydroxyethyl-N-2-hydroxytetradecylamine, N-hydroxyethyl-N-2-hydroxyhexadecylamine,
N-hydroxyethyl-N-2-hydroxyoctadecylamine, N, N-bis-hydroxyethyl-N-2-
Hydroxydodecylamine, N, N-bis-hydroxyethyl-N-2-hydroxytetradecylamine, N,
N-bis-hydroxyethyl-N-2-hydroxyhexadecylamine, N, N-bis-hydroxyethyl-N
It is 2-hydroxyoctadecylamine.

In the present invention, at least one of the above amine compounds is used in an amount of 0.1 to 5 with respect to 100 parts by weight of rubber.
Parts by weight It is preferably blended in a proportion of 0.5 to 3 parts by weight.
If the compounding amount is less than 0.1 parts by weight, the effect of the addition is not sufficient, and if it exceeds 5 parts by weight, not only the effect of increasing the amount disappears but also the scorch resistance of the rubber composition is remarkably deteriorated, which is not preferable.

In the present invention, the rubber is natural rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, synthetic polyisoprene rubber, butyl rubber, halogenated butyl rubber, ethylene-propylene-diene terpolymer rubber, and the like. May be a single compound or a blend of two or more compounds.

In the present invention, in addition to the above-mentioned amine compounds, compounding agents usually used in the rubber industry, for example, reinforcing fillers such as carbon black and silica, process oils, antioxidants, vulcanization accelerators, stearin. A vulcanization accelerating aid such as acid or zinc white, and a vulcanizing agent such as sulfur can be appropriately blended as necessary.

[0016]

In one of the objects of the present invention, there is heat aging prevention, and amine type anti-aging agents have the drawbacks of coloring or discoloring rubber, but generally they have excellent anti-aging performance. Therefore, while conducting tests on various amine compounds, it was discovered that this form of amine compound was effective, and the mechanism of action thereof is not clear. However, by adding an amine compound of this structure,
When kneading rubber, viscosity can be reduced, productivity reduction and energy loss due to repeated kneading can be prevented, not only factory workability is improved, but also elasticity after heat aging when used as a tire for a long time It has a great effect of preventing deterioration of rubber performance such as rate and elongation at break.

[0017]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. (Examples 1 to 7) (Comparative Example 1) ISAF carbon black 5 was added to 100 parts by weight of natural rubber.
0 parts by weight, 2 parts by weight of stearic acid, antioxidant (6C)
The rubber composition comprising 1 part by weight, 2.5 parts by weight of zinc, 0.7 parts by weight of N-tert-butyl-2-benzothiazolylsulfenamide and 1.5 parts by weight of sulfur is used as a rubber composition shown in Table 1. Various rubber compositions containing the amine compound of the present invention were kneaded with a Banbury mixer, and the Mooney viscosity (ML _{1 + 4} ) and Mooney scorch time (M
ST) was measured according to JIS K6300.

Then, each of these rubber compositions was applied to a thickness of 2 mm.
Sheet vulcanized at 145 ° C for 30 minutes,
Before heat aging and after heat aging under the condition of 100 ° C x 48 hours, JI
A tensile test was carried out according to SK6301, and the elastic modulus and elongation at break at 100% elongation were determined. The results are shown in Table 1.

[0019]

[Table 1]

As is clear from Table 1, the rubber compositions of Examples have lower Mooney viscosities than those of Comparative Examples, and the vulcanized physical properties show significantly less change due to heat aging.

(Examples 8 to 11) (Comparative Examples 2 and 3) 60 parts by weight of ISAF carbon black, 20 parts by weight of aroma oil, 2 parts by weight of stearic acid, and aged with respect to 100 parts by weight of styrene-butadiene copolymer rubber. Inhibitor (6
C) The amount of N-hydroxyethyl-N-2-hydroxydodecylamine was changed in a rubber composition consisting of 1 part by weight, 3 parts by weight of zinc white, 0.8 parts by weight of vulcanization accelerator and 1.7 parts by weight of sulfur. The various rubber compositions thus added were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0022]

[Table 2]

As is clear from Table 2, the synthetic rubber-based material has the same effect as the natural rubber-based material.

[0024]

EFFECT OF THE INVENTION The rubber composition of the present invention contains a specific amine compound, so that when the high reinforcing carbon black is added and the viscosity is increased, the viscosity can be lowered. The plant workability such as kneading workability, extrusion workability or rolling workability can be greatly improved by contributing to energy saving, and even when the tire product etc. is subject to thermal deterioration for a long period of time, elastic modulus, elongation at break, etc. Since the deterioration of performance can be remarkably reduced, it is an industrially extremely useful invention.

Claims (1)

What is claimed is: 1. At least one compound represented by the following general formula per 100 parts by weight of natural rubber and / or synthetic rubber: An improved rubber composition comprising 0.1 to 5 parts by weight of an amine compound.