JPH03126737A - Rubber composition for tread - Google Patents

Abstract

PURPOSE:To obtain a rubber composition for tread, consisting of a epoxidized natural rubber and, as necessary, a polymer, satisfying specific relationships in blend amount and epoxidation degree of the epoxidized natural rubber and blend amount of the polymer and especially having excellent performance on ice. CONSTITUTION:The objective rubber composition for tire tread, being a rubber composition consisting of a natural rubber(ENR) epoxidized at an amount of <=10mol and, as necessary, a polymer (natural rubber) and further containing filler, curing agent, etc., and (A) satisfying relationship expressed by formula I, preferably relationship expressed by formula II in blend amount of ENR or (B) satisfying relationship expressed by formula III, preferably relationship expressed by formula IV in blend amount of ENR when ENR epoxidized in the range of >10mol% to <=100mol% is used and especially having a good low temperature coefficient of friction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a rubber composition for use in treads of automobile tires and the like, and particularly for preventing slipping on ice.

(Problems to be Solved by the Prior Art and the Invention) Of the road surface conditions, waterways and snowy roads are slippery and dangerous for motor vehicles to drive. In order to prevent slipping and allow cars to run stably, spiked tires are used or tires are equipped with anti-slip tires.

However, spiked tires and tires equipped with tires are a source of so-called dust pollution, and on the other hand, non-slip tires are troublesome to replace.

In addition to the above, so-called winter tires such as snow tires and studless tires are widely used, and although these are effective for roads covered in fresh snow, they are not suitable for use on icy roads. It is still insufficient to prevent the slippage of 19j.

On the other hand, in order to solve the above-mentioned problems, a method of applying an anti-slip coating agent to the tire surface has also been proposed and put into practical use. With this method, you can expect a sliding effect on ice, but the coating agent will wear out in a short period of time! ll 1iill
However, although there has long been a demand for an excellent tread rubber composition to replace them, the reality is that no satisfactory proposal has yet been made.

As a result of intensive research and experiments in view of the above technical background, the present inventors focused on epoxidized natural rubber (hereinafter referred to as ENR), and discovered that it is possible to use epoxidized natural rubber (hereinafter referred to as ENR), which alone or in a specific amount of other diene rubbers, etc. (polymers). It was discovered that the blended trend rubber KJI compound effectively prevents tire slippage on snow or especially on ice, thereby effectively solving the problems of conventional products, and the present invention has been made based on this finding. It has come to this.

(Means for Solving the Problems) Based on this knowledge, the present invention employs the following stealing. That is, as a trend rubber composition, an ENR of 10 mol% or less
A rubber composition consisting of either alone or blended with a polymer, in which the amount of ENR to be blended satisfies the following formula.

Mata, a rubber composition made of epoxidized natural rubber (ENR) alone or blended with a polymer in a range of more than 10 mol% and 100 mol%, as a rubber for tread. The blending amount was determined to satisfy the following formula.

(Example) The present invention will be explained in detail below.

Natural rubber epoxidized in elastomer (hereinafter referred to as EN)
The rubber composition for a tread of the present invention is obtained by blending the rubber composition containing rubber alone or with an appropriate weight part in a polymer whose ENR is an elastomer.

It goes without saying that conventionally known components such as fillers and vulcanizing agents are blended into this tread rubber composition.

The present invention was originally published by E N Rff1l'L Germany or ENR
By varying the epoxidation degree of ENR and the blending amount of polymer, the vulcanized physical properties, especially the low-temperature friction coefficient (ice), were improved.
We conducted an experimental study to find out how ENR, ENR and polymer blending amount, and E
It has been found that suitable results can be obtained by selecting the degree of epoxidation of NR.

That is, when the degree of epoxidation of ENR is 10 mol% or less, it is preferable that
If the amount is 0 mol % or less, it is preferably ).

It should be noted that if the lower and upper limits of the above formulas (8) and (B) are exceeded, the low-temperature friction coefficient becomes small, which is not preferable.

Below, specific examples of the present invention are shown in Table 1 along with comparative examples.
Shown in Table 2.

Examples in Table 1 show ENR alone, ENR and natural rubber as a polymer, and examples in Table 2 show ENR and polybutadiene rubber as a polymer, and ENR, natural rubber, and polybutadiene rubber as a polymer. This shows an example of blending with Gen rubber, and all rubber compositions are examples of rubber compositions for tires.

(Effects of the Invention) According to the present invention, the low-temperature friction coefficient, that is, the performance on ice, is particularly excellent, and the other vulcanized physical properties are sufficiently satisfied, so that it can be used for automobile tires, tire anti-slip devices, endless track tracks, etc. It is useful as a rubber composition for treads.

Claims (1)

[Claims] (1) Epoxidized natural rubber (E
NR) alone or blended with a polymer, the rubber composition for a tread, characterized in that the blending amount of ENR satisfies the following formula. 0.4≦[(Blend amount of ENR)×(Epoxidation degree of ENR)^2]/[(Blend amount of ENR)+(Blend amount of natural rubber)]×100≦1(2) 10 mol% Epoxidized natural rubber (ENR) in a range exceeding 100 mol%
A rubber composition for a tread, characterized in that the amount of the ENR contained satisfies the following formula: 1≦[(Blend amount of ENR)×(Epoxidation degree of ENR)
^2]/[(ENR compounding amount) + (natural rubber compounding amount)
]×100≦5