JPH055016A - Chlorinated polyethylene composition - Google Patents

Abstract

PURPOSE:To obtain a colorable cross-linked rubber composition, excellent in extrusion processability and good in tensile strength and weather resistance with hardly any compression set,. CONSTITUTION:A cross-inked rubber composition consisting essentially of chlorinated polyethylene composed of (A) 100 pts.wt. chlorinated polyethylene, (B) 10-150 pts.wt. clay, having 0.1-1.0mum average particle diameter and treated with a mercapto-based silane coupling agent, (C) 0.5-20 pts.wt. organic peroxide and (D) 0.1-10 pts.wt. polyfunctional compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinked rubber composition which is excellent in extrusion processability, has good tensile strength and weather resistance, and can be colored.

[0002]

2. Description of the Related Art Chlorinated polyethylene is obtained by chlorinating a crystalline ethylene polymer and is a high-fillable polymer substance having excellent weather resistance, flame resistance and heat aging resistance. is there. Utilizing these characteristics, it is used in a wide range of applications such as industrial parts, building materials, and electric wires. When used as a crosslinked rubber, carbon black, white carbon (silica), etc. are filled for the purpose of improving strength.

[0003]

However, when carbon black is filled, there is a drawback that it is limited to black. Further, when the white carbon is filled, the surface roughness of the molded product by extrusion molding and the inconvenience that the corner portion cannot be molded according to the dimensions occur, and the extrusion processability is extremely deteriorated. In addition, water absorption is large in terms of characteristics, and there is a problem in its life. From the above, it is an object of the present invention to obtain a crosslinkable rubber composition which is excellent in extrusion processability, has good tensile strength and weather resistance, and can be colored.

[0004]

As a result of intensive studies, the inventors have found that the above objects can be achieved by a chlorinated polyethylene composition filled with clay treated with a specific silane coupling agent. The present invention has been completed. That is, the present invention comprises (A) 100 parts by weight of chlorinated polyethylene, (B) 10 to 150 parts by weight of clay having an average particle size of 0.1 to 1.0 μm and treated with a mercapto-based silane coupling agent, (C) Organic peroxide 0.5
˜20 parts by weight and (D) polyfunctional compound 0.1 to 10
It is a chlorinated polyethylene composition consisting of parts by weight. Hereinafter, the present invention will be specifically described.

(A) Chlorinated Polyethylene The chlorinated polyethylene used in the present invention is obtained by chlorinating powder or particles of polyethylene in an aqueous suspension or chlorinating polyethylene dissolved in an organic solvent. Although it is obtained by the above method, the one obtained by the former method is preferable. The chlorine content of the chlorinated polyethylene is generally 20 to 50% by weight,
Particularly, 25 to 45% by weight is preferable. If the chlorine content is less than 20% by weight, there are many residual crystals and a flexible rubber cannot be obtained. On the other hand, if it exceeds 50% by weight, the rubber elasticity becomes poor and a soft rubber cannot be obtained. Amorphous chlorinated polyethylene having no residual crystals is preferable because it has better flexibility, but it may be crystalline. The polyethylene is obtained by homopolymerizing ethylene or by copolymerizing ethylene with at most 10% by weight of α-olefin (generally having at most 12 carbon atoms). Its density is generally 0.910 to 0.970 g / cm ³ . The molecular weight is 50,000 to 700,000.

In producing the composition of the present invention, only chlorinated polyethylene may be used, but other types of rubbers compatible with chlorinated polyethylene may be blended. Examples of the rubber include ethylene-propylene-diene ternary copolymer rubber (EPDM), chloroprene rubber, ethylene vinyl acetate, chlorosulfonated polyethylene rubber and urethane rubber, and one or more of them are mixed. You may have. The compounding amount of these rubbers is 1 with respect to 100 parts by weight of chlorinated polyethylene.
It is preferably not more than 00 parts by weight.

(B) Clay The clay used in the present invention is a kaolin-based clay which contains naturally occurring hydrous aluminum silicate as a main component. The average particle size of the clay is 0.1 to 1.0 μ.
When the average particle size is less than 0.1 μ, the effect of improving tensile strength is poor, and when it exceeds 1.0 μ, the effect of improving tensile strength is poor, and extrudability is also reduced, which is not preferable. Further, the clay needs to be surface-treated with a mercapto-based silane coupling agent. The silane coupling agent is an organic silane compound used for the surface treatment for the purpose of improving the adhesion between the resin and the filler for resin such as glass fiber. Among these, the mercapto type is particularly excellent, and other coupling agents such as vinyl type and amino type are inferior in tensile strength and weather resistance. The mercapto-based silane coupling agent is
It is represented by the general formula R ₁ -Si (OR ₂ ) ₃ (R ₁ represents a mercaptoalkyl group and R ₂ represents an alkyl group), and examples thereof include γ-mercaptopropyltrimethoxysilane and γ- Examples thereof include mercaptomethyltrimethoxysilane and γ-mercaptoethyltrimethoxysilane. The surface treatment of clay may be performed by a usual method.

(C) Organic Peroxide The organic peroxide used in the present invention is not particularly limited, but it is preferable that the decomposition temperature (the temperature at which the half-life is 1 minute) be 120 ° C. or higher. , Especially 140 ℃
The above are preferred. A typical example of a suitable organic peroxide is 1,1-bis-tertiary-butylperoxy-
Ketone peroxide such as 3,3,5-trimethylcyclohexane, hydroperoxide such as 2,5-dimethylhexane-2,5-dihydroperoxide,
Examples include peroxyesters such as 2,5-dimethyl-2,5-di-tertiary-butylperoxyhexane, diacyl peroxides such as benzoyl peroxide, and dialkyl peroxides such as dicumyl peroxide.

(D) Polyfunctional Compound Further, the polyfunctional compound used in the present invention is a compound having at least two double bonds in one molecule. Examples of the compound include, for example, triallyl isocyanurate which is used as a crosslinking aid in the usual rubber field.

(E) Composition Ratio The composition ratio of other components to 100 parts by weight of chlorinated polyethylene is as follows. The mixing ratio of clay is 10
150 parts by weight, preferably 20 to 150 parts by weight,
More preferably, it is 30 to 130 parts by weight. If the compounding ratio of clay is less than 10 parts by weight, the effect of improving the properties is poor, and if it exceeds 150 parts by weight, not only the extrudability but also the mechanical properties are unfavorably deteriorated. The blending ratio of the organic peroxide is 0.5 to 20 parts by weight, preferably 1.0 to 15 parts by weight, and particularly 2.0 to
10 parts by weight is preferred. If the blending ratio of the organic peroxide is less than 0.5 parts by weight, the property improvement after crosslinking is not sufficient,
Further, even if it exceeds 20 parts by weight, the characteristics are not further improved. Furthermore, the compounding ratio of the polyfunctional compound is 0.1 to 1
It is 0 part by weight, preferably 0.5 to 8 parts by weight, and particularly preferably 1 to 5 parts by weight. When the compounding ratio of the polyfunctional compound is less than 0.1 part by weight, the improvement in properties after crosslinking is not sufficient, and when it exceeds 10 parts by weight, the properties are not further improved.

Although the composition of the present invention can be obtained by uniformly blending the above-mentioned substances, the fillers, plasticizers, oxygen, ozone, heat and heat which are commonly used in the rubber and resin industries can be obtained. Light (ultraviolet)
Additives such as stabilizers, lubricants, and colorants may be added depending on the intended use of the composition.

(F) Mixing Method When the composition of the present invention is produced, the method for mixing the composition is to use a mixer such as an open roll, a kneader or a Banbury mixer which is generally used in the art. And knead. The composition of the present invention is an extruder normally used in the general rubber industry,
A desired shape may be molded using a molding machine such as an injection molding machine, a compression molding machine, and a calender molding machine.
Further, in the rubber technical field, the chlorinated polyethylene composition is generally applied to a desired shape by applying a method for producing a molded product while crosslinking (vulcanizing), that is, a method of simultaneously advancing vulcanization and molding. You may shape.

[0013]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, the extrusion processability was as follows.
C., die temperature 70.degree. C., head temperature 70.degree. C., screw rotation 30 RPM, extrusion molding was performed, and the appearance of the obtained molded product is shown in the following four stages. ◎ Very good ○ Good △ Slightly bad × Poor The compression set is 100 ° C according to JIS K-6301.
After the sample was left in the oven set to, for 22 hours, the measurement was performed. The tensile test is based on JIS K-6301 according to JIS
No. Tensile strength (hereinafter referred to as "T _B ") and elongation (hereinafter referred to as "E _B ") were measured using a No. 3 dumbbell and a Shopper type tester. The weather resistance test is JIS
According to K-6301, temperature 63 ℃, precipitation 18 minutes / 120
After being left for 2000 hours in a weather meter (sunshine) set to minutes, a tensile test was conducted to determine the change rates of T _B and E _B. Moreover, the presence or absence of cracks and the presence or absence of discoloration were visually confirmed.

Example 1 100 parts by weight of amorphous chlorinated polyethylene having a chlorine content of 30.5% by weight was surface-treated with γ-mercaptopropyltrimethoxysilane shown in Table 1 to give an average particle size of 0.1.
50 parts by weight of 3 μ clay, 3 parts by weight of ketone peroxide 2,5-dimethylhexane-2,5-dihydroperoxide as an organic peroxide, 3 parts by weight of triallyl isocyanurate as a polyfunctional compound, and as a stabilizer. 10 parts by weight each of magnesia oxide and barium stearate, 20 parts by weight of adipic polyester as a plasticizer, and 20 parts by weight of titanium oxide as a pigment were blended. As the compounding method, first, the compound excluding the organic peroxide and the polyfunctional compound was put into a kneader kneader and kneaded under pressure for 20 minutes. Next, the kneaded product was wound around an open roll, and the organic peroxide and the polyfunctional compound were kneaded and then formed into a predetermined sheet. Table 2 shows the extrusion processability when the sheet was extrusion-molded. The compression set sample was crosslinked for 70 minutes at a pressure of 200 kg / cm ² and a temperature of 155 ° C. The compression set of the obtained crosslinked product is shown in Table 2. In addition, for the samples to be subjected to the tensile test and the weather resistance test, a die having a thickness of 1.5 mm and a width of 20 mm was attached to the tip of an extruder for rubber, and the cylinder temperature was 60 ° C, the die temperature was 70 ° C, the head temperature was 70 ° C, and the screw rotation was 30RP.
Set the value to M and perform extrusion molding.
Crosslinking was carried out for 70 minutes at a temperature of ° C. Table 2 shows the results of the tensile test and the weather resistance test of the obtained crosslinked product.

Examples 2-5, Comparative Examples 1-7 Sheets and crosslinked products were prepared in the same manner as in Example 1 except that the clay or calcium carbonate shown in Table 1 and the amounts thereof were used instead of clay. Got The results of the respective extrudability, compression set, tensile test and weather resistance test are shown in Table 2.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

The chlorinated polyethylene composition obtained by the present invention has the following characteristics. (1) It has excellent extrusion processability. (2) High tensile strength due to color mixture. (3) The compression set is small and the recoverability is good. (4) Good weatherability and no discoloration or fading of the composition. It can be used in various fields such as industrial parts, automobile parts, electric wires, and building materials. Typical examples of its use include building materials such as window frames of high-rise buildings and handrails of escalators.

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Claims (1)

Claims: 1. Clay 10 (A) 100 parts by weight of chlorinated polyethylene, (B) having an average particle size of 0.1 to 1.0 μm, and treated with a mercapto-based silane coupling agent.
˜150 parts by weight, (C) 0.5 to 20 parts by weight of organic peroxide, and (D) 0.1 to 10 parts by weight of a polyfunctional compound, a chlorinated polyethylene composition.