JPH01287154A - Rubber composition - Google Patents

Abstract

PURPOSE:To obtain a rubber composition having bending resistance, heat build-up resistance and tear resistance in spite of high filling carbon content and sulfur blend curing system, by blending a rubber with aluminum (meth) acrylate, sulfur and reinforcing carbon black. CONSTITUTION:The rubber composition obtained by blending (A) 100pts.wt. rubber (e.g. NR or NR/SBR blend rubber) with (B) 1-20pts.wt., preferably 3-15pts.wt. aluminum (meth)acrylate obtained by reacting (meth)acrylic acid with aluminum hydroxide gel, etc., in an aqueous or organic solvent and having <=2mum average particle size, (C) 0.5-10pts.wt., preferably 1.5-4pts.wt. sulfur for rubber and (D) 30-90pts.wt. carbon black (e.g. furnace black or thermal black) and capable of providing a rubber having high stretching properties in spite of highly filled blending of carbon.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to vulcanizable comb compositions.

(Prior art) Vulcanized rubber is made of rubber, zinc oxide, vulcanizing agents, vulcanization accelerators, and other necessary compounding agents. 11, 7; There are few products made with a compound composition that is said to be a pure rubber compound, and most rubber products contain various compounding agents such as reinforcing agents, fillers, and softeners. is common.

Particularly in the case of rubber products that require reinforcement, such as tires and belts, carbon black is used when the product is black, and silicic acid or silicate, which is generally referred to as white carbon, is used for white or light colors. .

However, carbon black has a very poor reinforcing effect, and the majority of actual comb products are black.

Among general diene rubbers, crystalline NR (natural rubber) has relatively high vulcanization properties, such as tensile strength, even with the pure rubber composition described above, but SBR (styrene-butadiene-IT), BR In the case of non-crystalline rubber such as (butadiene rubber), the tensile strength of a pure rubber compound is so low that it can hardly be put to practical use, and carbon black is an essential compounding agent for black rubber products.

When carbon black is used, the physical properties of the vulcanized rubber such as hardness, tensile stress, tensile strength, impact resilience, and abrasion resistance are improved.

However, when the hardness becomes high, the tensile elongation U at break decreases, and dynamic properties such as bending resistance and heat resistance also decrease.

On the other hand, in recent years, there has been a trend toward high-filling carbon compositions in tie A. etc. in order to improve light weight and abrasion resistance, and there is a desire for improvements in bending resistance, heat resistance, tear resistance, etc.

(Problems to be Solved by the Invention) The object of the present invention is to overcome the aforementioned drawbacks of the prior art.

That is, the present invention provides a rubber composition that improves dynamic properties such as bending resistance, heat resistance, and tear resistance, which are drawbacks of highly filled carbon and sulfur-containing vulcanization systems, and that can withstand practical use. .

(Means for Solving the Problems) As a result of repeated research without solving the above problems, the inventors of the present invention have developed aluminum acrylate into a sulfur vulcanized system containing high-filling carbon and a general cyanide rubber J1. and/or aluminum methacrylate, the hardness and tensile physical properties of the vulcanized rubber, such as tensile strength and tensile stress, are extremely little reduced, and the tensile elongation is large, as well as bending resistance, heat resistance, and tear resistance. The present invention was completed based on the discovery that properties such as properties can be improved.

That is, 1 to 20 parts by weight of aluminum acrylate and/or aluminum methacrylate having an average particle size of 2 μm or less, and 0.5 to 1 part by weight of sulfur per 100 parts by weight of rubber.
The present invention provides a vulcanizable rubber composition containing 0 parts by weight and 30 to 90 parts by weight of reinforcing carbon black.

The rubber used in the present invention includes one or more rubbers selected from NRlIR (isoprene rubber), BRl, and SBR, and other blended rubbers such as NBR (nitrile-butadiene rubber) and CR (chloroprene rubber).
, EPDM (ethylene-propylene-diene-based terpolymer), etc. may be blended as necessary.

Aluminum acrylate 11 and aluminum methacrylate in the present invention include, for example, aluminum hydroxide gel obtained by reacting acrylic acid or methacrylic acid with commercially available aluminum hydroxide gel or aluminum sulfate with caustic alkali, and aluminum J1 isopropoxide. It can be obtained by reacting an organoaluminum compound in an aqueous system or an organic medium that is not mutually soluble in water.

In the present invention, aluminum acrylate and aluminum methacrylate obtained by any of the above methods can be used, but it is essential that the average particle diameter of W is 211 [11 or less].

If the average particle size is larger than this, the dispersion into the rubber will be insufficient and the desired physical properties of the vulcanized rubber will not be obtained. The amount added is 1 to 20 parts by weight, preferably 3 to 15 parts by weight, per 100 parts by weight of the comb. If the amount is less than this, a sufficient effect cannot be obtained, and if it is more than this amount, it is unfavorable from the viewpoint of processability and physical properties.

As the sulfur used in the present invention, ordinary rubber sulfur can be used. The amount used is 0.5 to 1 per 100 parts by weight of rubber.
0 parts by weight, preferably 1.5 to 4 parts by weight. If the amount is less than this, a sufficient effect cannot be obtained, and if it is more than this amount, the heat aging resistance will deteriorate, which is not preferable.

As the carbon black used in the present invention, those for general rubber such as furnace black type and thermal black type can be used. The amount used is 30 to 90 parts per 100 parts by weight of rubber.
Parts by weight are preferably 50 to 70 parts by weight. If the amount is less than this, the reinforcing effect will be low, and if it is more than this amount, the processability will be difficult and it will be necessary to fill the process oil undesirably.

In the present invention, there are no particular restrictions on the mixing of aluminum acrylate, aluminum methacrylate, sulfur, carbon black, etc. into rubber, and known methods can be employed. Also, known conditions can be used for the vulcanization conditions.

The present invention has been developed for the first time by using a general sulfur vulcanization system with a certain amount of carbon black and a certain amount of aluminum acrylate and/or aluminum methacrylate of a certain particle size to produce a raw material that maintains processability with little change in Mooney viscosity. A vulcanized rubber is obtained, and the resulting vulcanized rubber 1 exhibits little change in hardness, suppresses the decrease in tensile strength and tensile stress, but has a large tensile elongation, and also has 1 flexibility, heat resistance, and resistance. It can improve tearability and has the effect of improving adhesion to metals.

(Examples) Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the same extent by these.゛Examples 1 to 2, Comparative Example 1 Comparative examples and aluminum acrylate (hereinafter referred to as A
A spiked sample (denoted as LA) was prepared.

Mooney scorch test of unvulcanized rubber and oscillating desk rheometer (hereinafter referred to as 0°D, R)
Each vulcanization test is JIS-K 13300.5R.
It was conducted in accordance with IS-3102.

Regarding the vulcanized rubber test, press vulcanization was performed using 1506CX for 15 minutes, and a tensile test using Tensilon, a bending test using Dematcher, and a peeling test for adhesion to metal were conducted in accordance with JIS-6301. The heat generation test was performed using a Guttrich flexometer with a temperature of 100°01 stroke: 0.22.
5 inches, load: 55 cylinders, and the exothermic temperature was measured after 25 minutes.

The formulation and various test results are shown in Table 1.

As shown in the table, compared to Comparative Example 1, Examples 1 and 2 showed improved tensile properties Ee and TR, had the effect of improving dynamic fatigue bending resistance and heat generation resistance, and had the effect of improving adhesion to metals. Sexuality is also improved.

Example 3, Comparative Example 2 Examples of NR/SBR blend rubber formulations are shown in Table 2.

The kneading and testing methods were the same as in Examples 1-2.

Tensile properties After 8 days, TR1 flex resistance improved.

Example 4, Comparative Example 3 Examples of SBR formulations are shown in Table 3. Similar to Example 3, the effect of improving the tensile properties EB and TR1 bending resistance was observed.

Example 5, Comparative Example 4 Examples of BR formulations are shown in Table 4. In the case of B R, Hs, M + IIIT8 compared to the above-mentioned Examples 1 and 2.
Despite these improvements, the E8 value is also improved, and the TR5 bending resistance is also improved.

(Effects of the Invention) The rubber composition obtained by the present invention has a high elongation rubber despite the high carbon filling, and has improved tear resistance and dynamic forming properties, and also has good adhesion to metals. Power is also good. Ideal for use in tires, healds, and industrial supplies.

Procedural amendment (formality) June 77, 1999

Claims (1)

[Claims] Average particle size per 100 parts by weight of rubber Acrylic acid with a particle size of 2 μm or less aluminum and/or aluminum methacrylate 1-20 parts by weight of minium, 0.5-20 parts by weight of sulfur 10 parts by weight, reinforcing carbon black It is characterized by containing 30 to 90 parts by weight. A vulcanizable rubber composition.