JPS5880336A - Flame-resistant vulcanized rubber composition - Google Patents

Abstract

PURPOSE:A composition capable of forming flame-resistant and inexpensive vulcanized rubbers, prepared by adding a viny chloride resin having a specified particle diameter and antimony trioxide or zirconium oxide to ethylene/propylene rubber. CONSTITUTION:To 100pts.wt. ethylene/propylene rubber base are added 20- 100pts.wt. polyvinyl chloride resin, particle diameter 0.1-10mu and 10-40pts.wt. antimony trioxide or zirconium oxide. To this composition are further added, if necessary, a vulcanizing agent, a softener, a filler or an antioxidant. The above ethylene/propylene rubber includes an ethylene/propylene/nonconjugated diene tercopolymer or a blend or this copolymer with another rubber, for example, butyl rubber, in which this copolymer constitutes at least 50wt% of the rubber base.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition for obtaining a vulcanized rubber that is flammable and inexpensive.

Ethylene 7-propylene rubber has excellent flexibility, low-temperature properties, and heat resistance, and is flame retardant when used in, for example, construction gaskets, automobile radiator hoses, ink, and electrical insulation parts. oxidation treatment is required.

For example, the following methods are known as conventional flame retardant methods.

(1) Water-containing compounds such as a/L/[nium hydroxide,
Method of blending in large quantities.

(2) A method in which a compound containing a halogen atom in the molecule, such as decabromophenoxybenzene, chlorinated paraffin, or chlorinated polyethylene, is combined with antimony dioxide or zirconium oxide.

Each of the vulcanized rubbers obtained by these methods has its own characteristics, so methods have been developed depending on the purpose.

For example, in the method of blending a/vtnium hydroxide, flame retardation can be achieved by blending a large amount in applications where the breaking strength of rubber may be relatively low. The flame-retardant vulcanized rubber obtained by this method has a low breaking strength, which has the drawback of limiting its uses.

In the method of blending a compound containing a halogen atom in the molecule together with antimony dioxide or zirconium oxide, the vulcanized rubber generally becomes extremely expensive. Also, originally ethylene
Since the polarity is different from that of propylene rubber, if a uniform dispersion is obtained by leaving the ship, the processing characteristics will deteriorate, resulting in poor wax quality of the product and significant deterioration in physical properties. When a polymer resin containing halogen atoms is added, the flexibility to withstand low temperatures, which is a characteristic of ethylene/propylene rubber, is impaired. The present invention was developed as a result of research into a composition for a flame-retardant ethylene e-propylene rubber vulcanized rubber with excellent processability.

That is, this invention uses powdered polyvinyl chloride having a specific particle size and blends it together with 10 to 40 parts by weight of antimony trioxide or zirconium oxide to make ethylene-propylene rubber flame retardant. By this,
ethylene.

It has been discovered that a highly flame-retardant vulcanized rubber exhibiting high tensile strength can be obtained without impairing the low-temperature properties of propylene rubber.

The powdered polyvinyl chloride SA/resin having a specific particle size used in the present invention refers to powdered polyvinyl chloride P having a particle size of 0.1 to 10 μm. This product is usually obtained by emulsion polymerization of vinyl chloride monomers.

The ethylene/propylene rubber used in the present invention is an ethylene Φ propylene 4 non-conjugated diene terpolymer, or a copolymer containing 50% by weight or more of the copolymer and other rubber in the rubber base material. , for example, refers to a mixture with butyl rubber.

Typical non-conjugated diene compounds constituting the ethylene/propylene/non-conjugated diene terpolymer are 1.4-hexadiene, 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, and dicyclo. Pentagen et al.

It is not clear why the flame-retardant vulcanized rubber according to the present invention maintains its low-temperature flexibility and exhibits high physical properties even though a relatively large amount of polyvinyl chloride resin has leaked into it. However, this is probably because the powdered polyvinyl chloride resin with a specific particle size is uniformly dispersed in the form of islands in the ethylene/propylene rubber matrix even after kneading, similar to general inorganic fillers. It is estimated that.

According to the present invention, the amount of specific polyvinyl chloride resin mixed in is 3.
The reason for limiting the amount to 0 to 100 parts by weight and 15 to 40 parts by weight of antimony trioxide or zirconium oxide is that below this range, sufficient flame retardance cannot be obtained, and above this range, the ethylene/propylene rubber This is because processability is impaired and tensile strength is significantly reduced.

Vulcanizing agents, softeners, fillers, antioxidants, etc., which are added as necessary in order to meet the requirements for processability, physical properties, price, etc., in the implementation of the present invention are generally used in the rubber industry. For example, the following can be used:

Examples of vulcanizing agents: Zinc/dimethyldithiocarbamate, dithioic acid salts such as zinc/dimethyldithiocarbamate, zinc/dimethyldithiocarbamate; thiurams such as tetramethyl-thiuram disulfide; thiazoles such as dibenzothiazyl disulfide; diphenylguanidine Dicumyl peroxide containing guanidines such as 111. Peroxides such as di(1-butylperoxy)-3,3,5-)limethylcyclohexane.

In addition to these, zinc oxide, stearic acid, and sulfur are added as necessary.

Examples of softeners: Paraffinic, naphthenic, and aromatic process oils can be used. However, when a relatively large amount of oil .mu. is blended, paraffinic or naphthenic oils are preferred from the viewpoint of the external appearance of the product.

Examples of fillers include carbon black, talc, clay, and silica commonly used in the rubber industry.

Calcium carbonates are not preferred because they tend to reduce the flame retardancy of the present invention.

Examples of antioxidants that can be used include styrenated pheno-μ, N-phenylated isopropyl p-P-phenylene diamine, dibutyl dithiocarbamate, trisnonylphenyl phosphite, and the like.

In addition, as in the case of ordinary vulcanized rubber formulations, zinc stearate, diethylene glycol, preethylene glycol, alkylphenol-formaldehyde resin, Alifatec hydrocarbon, etc. are used as adhesive agents to improve processability. Resins and the like can also be added as necessary.

The various compounding agents including the specific polyvinyl chloride resin powder used in the present invention can be kneaded in the same manner as ordinary flame-retardant rubber using a mixing glow μ or a closed kneading machine commonly used in the rubber industry. It can be kneaded using this method. Furthermore, the molding and vulcanization methods can be the same as those for ordinary flame retardant rubber.

The flame-retardant ethylene/propylene rubber composition according to this invention has severe flame retardancy and low-temperature flexibility.

It can be applied as architectural rubber materials and electrical insulation materials that require

Next, the present invention will be explained in more detail with reference to Examples.

Note that the present invention is not limited to this example.

Table ls1 shows examples of formulations for 100 parts by weight of ethylene-propylene rubber. In order to clarify the characteristics of the present invention, many examples other than the present invention were also shown.

An 8-inch mixing roll was used for the mixed track roll.

The resulting formulation was vulcanized using a hot press at 160°C for 20 minutes. The measured values are shown in Table 2.

These results show that a composition using polyvinyl chloride powder with a limited particle size as a flame retardant can produce a flame-retardant vulcanized rubber with high tensile strength and flexibility at low temperatures. .

Among them, the vulcanized rubber sheet according to the present invention exhibited good appearance with no bleeding or blooming observed.

Claims (1)

[Claims] 20 to 100 parts by weight of polyvinyl chloride resin with a particle size of 0.1 to 10 s- to 100 parts by weight of ethylene/propylene rubber base material
100 parts by weight and 10 to 40 parts by weight of antimony dioxide or zirconium oxide, and further contains a vulcanizing agent, a softening agent, selected as necessary,
A composition for vulcanized rubber that is loaded with fillers or antioxidants.