JP3235226B2 - Chlorinated ethylene rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chlorinated ethylene rubber composition which has extremely low mechanical fatigue and cracks due to ozone. More specifically, the present invention relates to a rubber composition having excellent mechanical strength (for example, tensile strength) and good abrasion resistance.

[0002]

2. Description of the Related Art As is well known, chlorinated ethylene polymers are widely used in the fields of automobile parts, industrial parts and household electric appliances. However, when the chlorinated product is used in the automobile parts field, extruded products (hoses, tubes, etc.) or molded products (packings, boots, etc.) are usually manufactured in order to add a large amount of carbon black, and the ozone-resistant product is manufactured. Cracks often occur when the durability test and the mechanical fatigue test are performed. For this reason, it is pointed out that the reliability of the product is poor. In order to solve such a problem, a method such as selecting a type of carbon black (one having a small structure) has been devised, but it is still insufficient. To improve this, the present inventors have already proposed a rubber mixture using an organic peroxide (JP-A-2-28943).

[0003]

However, since the rubber mixture uses an organic peroxide as a cross-linking agent, there is a problem in the process due to a delay in a cross-linking reaction, for example,
There are drawbacks such as poor mold release, difficulty in steam vulcanization, and an increase in cost due to the use of a relatively expensive crosslinking agent.

The present invention has been made in view of the above circumstances, and has excellent vulcanization means and chlorination having physical properties excellent in ozone resistance and fatigue resistance, which are easily accepted in the conventional rubber processing field. An object is to provide an ethylene-based rubber composition.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by using a specific vulcanizing agent and a specific organic sulfur compound in combination, and based on this finding, Thus, the present invention has been completed.

That is, the present invention relates to (A) 100 parts by weight of a chlorinated ethylene-based polymer, and (B)
Metal oxides, hydroxides, carbonates, carboxylates, silicon
, Borate and phosphite and Periodic Table I
Group Vb metal oxides, basic carbonates, basic carboxyls
Acid salts, basic phosphites, basic sulfites and tribases
Selected from water-soluble sulfates and hydrotalcite stones
1.0-15 parts by weight of a metal compound serving as an acid acceptor, (C)
5 to 100 parts by weight of carbon black having a structure of 150 ml / 100 g or less according to oil absorption, (D)
An organic sulfur compound represented by the general formula (I) 0.5 to
10 parts by weight, R ₁ —S—CH ₂ —CH ₂ —COOH (I) (wherein R ₁ represents a linear alkyl group having at most 18 carbon atoms). II) an amine salt of mercaptobenzothiazole represented by the formula or an amine salt of dithiocarbamic acid represented by the formula (III): 1.0 to 10 parts by weight;

[0007]

Embedded image

(Wherein R ₂ , R ₃ and R ₄ may be the same or different and are hydrogen or a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom) Or R ₂ , R ₃ and R ₄ may be bonded to each other to form a hydrocarbon ring, and further bonded via a hetero atom to form a heterocyclic ring, It cannot be hydrogen at the same time.)

[0009]

Embedded image

(Wherein R ₅ and R ₆ may be the same or different and are a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom, or R ₅ and R ₆ may be bonded to each other to form a hydrocarbon ring, or may be bonded to each other via a hetero atom to form a heterocyclic ring.)

(F) a mercaptotriazine compound represented by the general formula (IV): 0.01 to 5.0 parts by weight;

[0012]

Embedded image

(Wherein R ₇ is selected from the group consisting of a mercapto group and an amino group) and (G) a chlorinated ethylene rubber composition comprising 5 to 50 parts by weight of a plasticizer for polyvinyl chloride resin. Is what you do. Hereinafter, the present invention will be described specifically.

(A) Chlorinated ethylene polymer The chlorinated ethylene polymer used in the present invention is a chlorinated product obtained by reacting chlorine with a polymer containing ethylene as a main component, which will be described later. Examples of the polymer containing ethylene as a main component include an ethylene homopolymer, a copolymer of ethylene and an α-olefin, an ethylene-propylene copolymer having a small amount of crystal, and at least ethylene and an α, β-unsaturated. Copolymers with dicarboxylic acids or anhydrides thereof are mentioned.

An ethylene homopolymer and ethylene and α-
The copolymer with olefin is obtained by homopolymerizing ethylene or copolymerizing ethylene with at most 20% by weight of an α-olefin (generally having 3 to 12 carbon atoms). Its density is generally 0.910
0.970 g / cc. Further, its molecular weight is at least 30,000, and particularly preferably 50,000 to 700,000.

In addition, ethylene having a slight crystal fraction
The propylene copolymerization ratio of the propylene copolymer is usually 1
5 to 40% by weight, preferably 18 to 40% by weight,
Particularly, 20 to 38% by weight is suitable. When the copolymerization ratio of propylene is 15% by weight, the obtained chlorinated ethylene-propylene copolymer has poor rubber-like elasticity, and is rather plastic-like in the product. On the other hand, when the content exceeds 40% by weight, particles of the chlorinated ethylene-propylene copolymer obtained during chlorination become large, and are not preferable because they are aggregated in the reaction system.

Also, the melt index of the ethylene-propylene copolymer (according to JIS K7210,
The condition (measured at 14; hereinafter referred to as “MI (1)”) is usually 0.01 to 5.0 g / 10 min, and 0.02 to 5.0 g.
/ 10 minutes is desirable, and especially 0.05 to 5.0 g / 10 minutes is suitable. With an ethylene-propylene copolymer having an MI (1) of less than 0.01 g / 10 minutes, the resulting chlorinated ethylene-propylene copolymer has poor processability. on the other hand,
If it exceeds 5.0 g / 10 minutes, the reaction efficiency in chlorination is poor, and the chlorinated products are agglomerated.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the ethylene-propylene copolymer is usually 10 to 180, preferably 10 to 170, particularly preferably 10 to 150. In ethylene-propylene copolymers having a Mooney viscosity of less than 10, chlorinated products agglomerated during chlorination. On the other hand, if it exceeds 180, rubber-like elasticity is poor,
Rather, it is plastic-like.

The ethylene-propylene copolymer was obtained by using a differential scanning calorimeter (Differential Sc
Annealing Calorimeter, DSC) usually has a melting peak of 80 ° C. or more,
5 ° C is preferable, and particularly preferably 85 to 125 ° C. If the melting peak is lower than 80 ° C., the chlorination reaction is not preferable because it becomes a lump during the chlorination reaction and a uniform chlorinated product cannot be obtained.

The ethylene-propylene copolymer usually has a crystallinity of 3% or more as measured by X-ray,
0% is desirable, and 3 to 45% is particularly preferable. If the degree of crystallinity is less than 3%, the chlorination stage will result in a lump,
Similarly, a uniform chlorinated product cannot be obtained.

Further, the ethylene-propylene copolymer is subjected to gel permeation chromatography (GPC).
Polymerization average molecular weight (M
w) / number average molecular weight (Mn) is usually 4 or more;
To 8 are preferred. If Mw / Mn is less than 4, the resulting chlorinated product is not preferred because of poor processability.

Further, at least a copolymer of ethylene and an α, β-unsaturated dicarboxylic acid or an anhydride thereof may be a copolymer of ethylene and an “α, β-unsaturated dicarboxylic acid and / or an anhydride thereof” (hereinafter referred to as “comonomer (1) ))), And in addition to ethylene and the comonomer (1), at least one selected from the group consisting of unsaturated carboxylic acid esters, alkoxyalkyl acrylates and vinyl esters as the third copolymerization component (Hereinafter, referred to as “comonomer (2)”).

Among the comonomers (1), the α, β-unsaturated dicarboxylic acid usually has at most 20 carbon atoms, especially preferably 4 to 16 carbon atoms. Representative examples of the dicarboxylic acids include maleic acid, fumaric acid, itaconic acid, citraconic acid, 3,6-endomethylene-1,2,2
3,6-tetrahydro-cis-phthalic acid.
Among the α, β-unsaturated dicarboxylic acid components of the present invention, the anhydride of the α, β-unsaturated dicarboxylic acid is preferable, and maleic anhydride is particularly preferable.

Among the comonomers (2), the unsaturated carboxylic acid ester usually has 4 to 40 carbon atoms, especially 4 to 40 carbon atoms.
Twenty are preferred. As a typical example, those having good thermal stability such as methyl (meth) acrylate and ethyl (meth) acrylate are preferable.

Further, the alkoxyalkyl acrylate usually has at most 20 carbon atoms. Further, an alkyl group having 1 to 8 (preferably 1 to 4) carbon atoms is preferable, and an alkoxy group having 1 to 8 (preferably 1 to 4) carbon atoms is more preferable. Is desirable. Representative examples of preferred alkoxyalkyl acrylates include methoxyethyl acrylate, ethoxyethyl acrylate, and butoxyethyl acrylate.

The vinyl ester generally has at most 20 (preferably 4 to 16) carbon atoms. Representative examples of suitable vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pipeparate and the like.

In the ethylene copolymer used in the present invention, the copolymerization ratio of the comonomer (1) is usually 0.5 to 2
5 mol%, preferably 1.0 to 25 mol%, and particularly preferably 1.0 to 20 mol%. If the copolymerization ratio of the comonomer (1) is less than 0.1 mol%, the effect of the obtained chlorinated product will not be exhibited. On the other hand, if it exceeds 25 mol%, there is a problem in cost and production in industrial production.

In the present invention, the terpolymer comprising ethylene, comonomer (1) and comonomer (2) has no blocking during chlorination, and the reaction can be easily carried out. Further, the obtained chlorinated ethylene copolymer is preferable because of excellent rubber elasticity and heat resistance.

The copolymerization ratio of the comonomer (2) is generally at most 25 mol% in terms of production and cost, and is preferably from 0.5 to 25 mol%, more preferably from 1.0 to 25 mol%. Those having 25 mol% are preferred.

Melt index of the ethylene copolymer (measured under condition 4 in accordance with JIS K7210)
Hereinafter, “MI (2)”) is usually 0.1 to 100 g /
The duration is 10 minutes, preferably 0.5 to 100 g / 10 minutes, particularly preferably 1.0 to 100 g / 10 minutes.
If the MI (2) is less than 0.1 g / 10 minutes, the moldability and kneading properties of the obtained chlorinated ethylene copolymer are not good. on the other hand,
If it exceeds 100 g / 10 minutes, the mechanical properties of the chlorinated ethylene copolymer obtained are not good.

The chlorinated ethylene polymer of the present invention can be obtained by chlorinating these polymers. The chlorination can be achieved by applying a chlorination method in an aqueous suspension commonly performed for producing these chlorinated products.

The chlorine content of the chlorinated ethylene polymer is generally 15 to 45% by weight, preferably 17 to 45% by weight, and more preferably 20 to 43% by weight. If the chlorine content of the chlorinated ethylene-based polymer is less than 15% by weight, a reaction can be performed in the production, but it becomes very difficult in the water washing step during post-treatment. On the other hand, when the content exceeds 45% by weight, the obtained chlorinated ethylene-based polymer is hard and not elastomer-like.

The Mooney viscosity (ML _{1 + 4} , 100
° C) is usually 10 to 15 from the viewpoint of moldability and mechanical properties.
0, preferably 10 to 130, particularly preferably 10 to 120
Is preferred.

[0034] (B) a acid acceptor metal compound The metal compound serving as acid acceptor used in the present invention, an oxide of Group II metal of the periodic table, hydroxides, carbonates, carboxylates Salts, silicates, borates and phosphites and oxides, basic carbonates, basic carboxylate, basic phosphite, basic sulfite of metals of group IVb of the Periodic Table And tribasic sulfates and hydrota
There is no particular limitation as long as it is a group of lucite stones, and a well-known chlorinated
Metal compounds used for cross-linking of Tylene resin can be used.
You.

Representative examples of the metal compound include magnesium oxide (magnesia), magnesium hydroxide, magnesium carbonate, barium hydroxide, barium carbonate , calcium oxide (quick lime), calcium hydroxide (slaked lime), calcium silicate, and steer. Calcium phosphate, calcium phthalate, magnesium phosphite, calcium phosphite,
Zinc oxide (zinc white), tin oxide, litharge, lead red, dibasic lead phthalate, dibasic lead carbonate, lead stearate, basic lead phosphite, basic tin phosphite, basic lead sulfite And tribasic lead sulfate. Also, Hydro Tulsa
Itoite group has a general formula of Mg _a Me _b (OH) _c CO ₃ .nH
₂ O (Me is Al, Cr or Fe, a is 1
An integer of 10 to 10, b is an integer of 1 to 5, c is 10 to 20
And n represents an integer of 0 to 8, respectively. )
It is a compound shown by these. In the above equation, n is 0
Is obtained by calcining the compound at a temperature of 250 to 350 ° C.
Equivalent to water removed. The average particle size of the compound is
In general, the thickness is 0.1 to 150 μm, especially 0.5 to 150 μm.
It is preferably 100 μm. Hydrotalcite stone group
Examples of _{Mg 4.5 Al 2 (CO 3)} (OH) 13 · 3.
_{5H 2 0, Mg 6 Al 2} (CO 3) (OH) 16 · 4H 2 0 , etc.
Is mentioned.

The average particle size of the metal compound is usually 0.1 to 1
00 μm, preferably 0.2 to 100 μm, more preferably 0.5 to 50 μm. Average particle size 0.1
If it is less than μm, scattering occurs during kneading, and there is a problem in handling. On the other hand, if it exceeds 100 μm, secondary aggregation is likely to occur and it is difficult to uniformly disperse.

(C) Carbon Black The carbon black used in the present invention is:
It is a black fine powder obtained by incomplete combustion or thermal decomposition of natural gas or liquid hydrocarbons.
ml / 100 g or less, especially 130 ml / 10
0 g is preferred. 15 structures depending on oil absorption
If it exceeds 0 ml / 100 g, there is a problem in workability and the hardness is remarkably increased. Representative examples of the carbon black include thermal black and carbon black produced by the furnace black method. About these carbon blacks, "Carbon Black Handbook" edited by the Carbon Black Association (Book Publishing Company, published in 1972), "Handbook, Rubber and Plastic Compounding Chemicals" edited by Rubber Digest (Rubber Digest, published in 1974) Their production methods and physical properties are well known.

(D) Organic Sulfur Compound The organic sulfur compound used in the present invention is an alkylthiopropionic acid represented by the general formula (I). R ₁ —S—CH ₂ —CH ₂ —COOH (I) (wherein R ₁ represents a linear alkyl group having at most 18 carbon atoms.) The compound generally has a specific gravity of 0.8 to 0.8.
It is a solid having a melting point of 40 ° C. or higher and 1.1 g / cm ³ . A typical example is β-alkyl (C _10-18 ) thiopropionic acid.

(E) Mercaptobenzothiazole amine salt and dithiocarbamic acid amine salt The mercaptobenzothiazole amine salt used in the present invention is composed of mercaptobenzothiazole represented by the general formula (II) and primary And salts with secondary or tertiary amines.

[0040]

Embedded image

(Wherein R ₂ , R ₃ and R ₄ may be the same or different and are hydrogen or a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom) Or R ₂ , R ₃ and R ₄ may be bonded to each other to form a hydrocarbon ring, and further bonded via a hetero atom to form a heterocyclic ring, It cannot be hydrogen at the same time.)

The hydrocarbon group in the salt is selected from an alkyl group, a cycloalkyl group, an allyl group and an aralkyl group, and preferred examples are a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, A benzyl group.

Examples of the amine salt in the salt include ethylamine, propylamine, hexylamine, octylamine, laurylamine, cyclohexylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, dilauryl. Amines, dicyclohexylamine, piperidine, pipecoline, morpholine, piperazine and the like.

Specific examples of the salt include cyclohexylamine salt of 2-mercaptobenzothiazole, dicyclohexylamine salt of 2-mercaptobenzothiazole,
-Tricyclohexylamine salts of mercaptobenzothiazole and the like.

The amine salt of dithiocarbamic acid used in the present invention is a compound represented by the general formula (III).

[0046]

Embedded image

(In the formula, R ₅ and R ₆ may be the same or different and are each a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom, or R ₅ and R ₆ may be bonded to each other to form a hydrocarbon ring, or may be bonded to each other via a hetero atom to form a heterocyclic ring.)

The hydrocarbon group in the compound is selected from an alkyl group, a cycloalkyl group, an allyl group and an aralkyl group, and preferred examples are a methyl group, an ethyl group,
Examples include a propyl group, a butyl group, a cyclohexyl group, and a benzyl group.

The dithiocarbamic acid forming the compound includes dimethyldithiocarbamic acid, diethyldithiocarbamic acid, pentamethylenedithiocarbamic acid, dibutyldithiocarbamic acid, ethyl-phenyldithiocarbamic acid, dibenzyldithiocarbamic acid, piperidinedithiocarbamic acid, pipecolinedithiocarbamic acid, Morpholine dithiocarbamic acid, piperazine dithiocarbamic acid and the like. Further, as an amine which is one component of the compound, ethylamine, propylamine, hexylamine, octylamine, cyclohexylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dicyclohexylamine, piperidine, pipecoline, morpholine, piperazine And the like.

Specific examples of the compound include pentamethylenedithiocarbamic acid piperidine salt, pipecolyldithiocarbamic acid pipecolyl salt, pentamethylenedithiocarbamic acid morpholine salt, pentamethylenedithiocarbamic acid piperazine salt and the like.

(F) Mercaptotriazine-based compound The mercaptotriazine-based compound used in the present invention is used as a vulcanizing agent or a vulcanization accelerator in the rubber industry. It is a compound represented by the formula.

[0052]

Embedded image

(Wherein R ₇ is selected from the group consisting of a mercapto group and an amino group.) In the above formula (IV),
Among ₇ , the amino group may have a hydrocarbon group having at most 20 carbon atoms.

Typical examples of the compound include 1,3,5-
Trithiocyanuric acid, 1-hexylamino-3,5-dimethylcaptotriazine, 1-diethylamino-3,5
-Dimethylcaptotriazine, 1-cyclohexylamino-3,5-dimethylcaptotriazine and the like. These compounds are described in detail in JP-A-59-10099.

(G) Plasticizer for polyvinyl chloride resin The plasticizer for polyvinyl chloride resin used in the present invention is widely used as a plasticizer for polyvinyl chloride resin and is well known. . The plasticizer includes phthalic acid derivatives, trimellitic acid derivatives, paraffin derivatives, adipic acid derivatives, sebacic acid derivatives, epoxy derivatives, fumaric acid derivatives, maleic acid derivatives, oleic acid derivatives, phosphoric acid derivatives and those having a diallyl group. It is roughly divided. For these plasticizers, see Physical Properties, Trade Names, Chemical Names, etc., on pages 145 to 191 of Rubber Digest Co., Ltd., Handbook, Rubber / Plastic Compounded Chemicals (Rubber Digest, 1974). It is described in detail.

Further, other vulcanization accelerators may be added. The accelerator is generally widely used as a vulcanization accelerator in the rubber industry. A typical example is
It is classified into thiazole type, imidazoline type, dithiocarbamate type, thiuram type, xanthate type, guanidine type and aldehyde-amine type. In addition, the publication No.
Nucleophiles such as the phosphorus compounds described on page 64 and pages 170 to 173 can also be used as vulcanization accelerators. About these vulcanization accelerators, JP-A-59-15440
A representative example is described in the specification of Japanese Patent Application Laid-Open Publication No. H10-209,837.

(H) Mixing ratio In the present invention, the mixing ratio of other components to 100 parts by weight of the chlorinated ethylene polymer is as follows. The metal compound is 1.0 to 15 parts by weight, preferably 2.0 to 15 parts by weight, and particularly preferably 3.0 to 12 parts by weight. When the amount of the metal compound is less than 1.0 part by weight, the chlorinated ethylene-based polymer causes a dehydrochlorination reaction. On the other hand, when the amount exceeds 15 parts by weight, processability deteriorates, and the strength of the obtained vulcanized rubber further decreases. Carbon black is 5.0
To 100 parts by weight, preferably 5.0 to 95 parts by weight, more preferably 7.0 to 90 parts by weight. If the carbon black content is less than 5.0 parts by weight, the reinforcing properties of the rubber are inferior.
On the other hand, if it exceeds 100 parts by weight, the workability is reduced.

The amount of the organic sulfur compound is 0.5 to 10 parts by weight, preferably 1.0 to 10 parts by weight, particularly preferably 1.0 to 8 parts by weight. When the organic sulfur compound is 0.
If the amount is less than 5 parts by weight, ozone resistance and fatigue resistance are inferior.
On the other hand, if it exceeds 10 parts by weight, bleed out occurs on the surface of the molded product.

The amine salt of benzothiazole or amine salt of dithiocarbamic acid is 1.0 to 10 parts by weight, preferably 1.5 to 10 parts by weight, more preferably 1.5 to 10 parts by weight.
8 parts by weight are preferred. When the salt is less than 1.0 part by weight,
Vulcanization does not proceed sufficiently. On the other hand, even if it exceeds 10 parts by weight, the vulcanizability is not further improved. Further, the amount of the mercaptotriazine-based compound is 0.01 to 5.0 parts by weight,
0.02 to 5.0 parts by weight are preferred, and particularly 0.1 to 4.0 parts by weight.
0 parts by weight is preferred. If the amount of the mercaptotriazine compound is less than 0.01 parts by weight, the crosslinking does not proceed tightly. On the other hand, if it exceeds 5.0 parts by weight, the high-temperature tear strength decreases. Further, the total amount of the plasticizer is 5.0 to 50 parts by weight, preferably 5.0 to 45 parts by weight, more preferably 5.0 to 45 parts by weight.
40 parts by weight are preferred. If the amount of the plasticizer is less than 5.0 parts by weight, the resulting composition has poor processability. On the other hand, if it exceeds 50 parts by weight, bleed out occurs on the surface of the molded article.

Further, when the above-mentioned other vulcanization accelerator is added, it is generally at most 10 parts by weight.

(I) Mixing method, vulcanization method, molding method, etc. The composition of the present invention can be obtained by uniformly mixing the above substances, and further, fillers generally used in the rubber industry, Additives such as plasticizers, various stabilizers, lubricants and coloring agents can be added according to the purpose of use. In order to obtain the composition of the present invention, mixing which is generally performed in the rubber industry may be applied. When producing this composition, it is important that the chlorinated ethylene polymer is not essentially vulcanized. For this purpose, the mixing is generally carried out at room temperature to 100 ° C.

The composition thus obtained is formed into a desired shape using a generally used extrusion molding machine, injection molding machine, compression molding machine or the like. Vulcanization is usually 100 ~
It is heated in a temperature range of 200 ° C. by a steam can, an air bath, or the like during molding. The vulcanization time varies depending on the vulcanization temperature, but is generally 0.5 to 30 minutes.

[0063]

The present invention will be described in more detail with reference to the following examples. The tensile test Tensile using Schopper testing machine using JIS3 dumbbell in accordance with JIS K6301 strength (hereinafter, referred to as T _B), elongation (hereinafter, E
_B ) and hardness (hereinafter, referred to as H _S ). Moreover, heat aging test, after the temperature was allowed to stand JIS3 dumbbell 3 days in JIS gear oven set at 120 ° C., T _B, to measure the E _B and H _S, the rate of change of T _B and E _B And the change in H _S was determined.

Further, the compression set test was conducted according to JIS K63.
After compression for 25% in accordance with No. 01 and left in a gear oven tester set at a temperature of 120 ° C. for 3 days, the thickness of the sample was measured, and the strain rate (%) of the sample was measured.

The ozone resistance test was carried out according to JIS K630.
The temperature is 40 ° C. and the ozone concentration is 50 pphm according to 1.
A dynamic test was performed using a JIS # 25 dumbbell under conditions where the elongation rate was 0 to 3%, and the state of crack generation was visually observed. Further, the mechanical fatigue test was performed using a demater bending tester at a temperature of 40 ° C. and an elongation of 0 to 100% using a JIS # 2 dumbbell at a rotation speed of 300 times / minute to generate cracks. The situation and the number of cracks were observed. The production, physical properties, types, and the like of the materials used are shown below.

[Chlorinated ethylene-based polymer] An ethylene-butene-1 copolymer containing 3% by weight of butene-1 (density: 0.94 g / cc, average molecular weight: about 170,000) was chlorinated by an aqueous suspension method. Amorphous chlorinated polyethylene (hereinafter referred to as chlorinated product (a)) having a chlorine content of 36.5% and a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 74, and a propylene content of 22% by weight And a Mooney viscosity of 115
The chlorine content obtained by chlorinating the ethylene-propylene copolymer is 35.4% by weight, and the Mooney viscosity is 42.
And a ethylene-methyl methacrylate-maleic anhydride (methyl methacrylate) having a melting point of 108 ° C. and a melt flow rate of 100 g / 10 min. Chlorine content obtained by chlorinating a content of 18.5 mol% and a maleic anhydride content of 1.5 mol%) is 3%.
A chlorinated ethylene terpolymer having a 2.5% by weight Mooney viscosity of 32.5 (hereinafter referred to as chlorinated product (c)) was used.

[Metal compound] Further, as the metal compound,
Particle size 100 mesh pass, specific surface area 150m ²
/ G of magnesium oxide (Kyowa Mag 150, manufactured by Kyowa Chemical Co., Ltd.) (hereinafter referred to as MgO).

[Carbon Black] The carbon black has an average particle diameter of 35 nm and an oil absorption of 105 ml.
/ 100 g of furnace method carbon black (manufactured by Showa Cabot Co., Ltd., Show Black MAF) (hereinafter referred to as CB) was used.

[Organic Sulfur Compounds] As organic sulfur compounds, β-tridecylthiopropionic acid having a melting point of 52 ° C. (hereinafter referred to as dispersant-1) and β-undecylthiopropionic acid having a melting point of 50 ° C. Hereinafter, dispersant-2
Was used.

[Amine salt of benzothiazole, amine salt of dithiocarbamic acid] As an amine salt of benzothiazole, dicyclohexylamine salt of 2-mercaptobenzothiazole (hereinafter, referred to as amine-1) and an amine salt of dithiocarbamic acid, pipecoli Pipecoline salt of rudithiocarbamic acid (hereinafter referred to as amine-2) was used.

[Mercaptotriazine-based compound] As the mercaptotriazine-based compound, 1,3,5-mercapto-S-triazine (hereinafter referred to as azine) was used.

[Plasticizer] Trioctyl trimellitate (hereinafter referred to as TOTM) and dioctyl sebacate (hereinafter referred to as DOS) were used as plasticizers.

[Other Vulcanization Accelerators and Additives] Further, tetrabutylthiuram disulfide (hereinafter, referred to as TBT) as a vulcanization accelerator and 2,2,2 as an additive
A 4-trimethyl-1,2-dihydroquiniline polymer (hereinafter referred to as an antioxidant) was used.

Examples 1 to 9 and Comparative Examples 1 to 5 Chlorinated ethylene copolymers, metal compounds, carbon blacks, organic sulfur compounds, benzothiazole or dithiocarbamic acid whose types and amounts are shown in Table 1 An amine salt, a mercaptotriazine compound and a plasticizer, and 0.5 parts by weight of TBT and 1 part by weight of an antioxidant were previously prepared at room temperature using an open roll.
The mixture was kneaded for 0 minutes to form a sheet. Each of the obtained sheets was heated at a temperature of 165 ° C. and a pressure of 200 kg / cm ² for ² hours.
A cross-linked sheet was prepared by hot pressing for 0 minutes.

The normal characteristics of each of the obtained sheets are T _B ,
E _B and H _S and T _B as heat resistance test, the rate of change of E _B and H _S, compression set characteristics (strain rate), the ozone resistance test (crack generation time) and fracture times due to mechanical fatigue test (bending test ) Was measured. Table 2 shows the results.

[0076]

[Table 1]

[0077]

[Table 2]

Further, the surface and the cross section of each of the obtained crosslinked sheets were observed at a magnification of 500 times using a scanning microscope. As a result, in Examples, no carbon black exposed on the surface or the cross section was observed. The presence of secondary aggregates (agglomerates) of carbon black was also small. On the other hand, in the comparative example, carbon black was exposed on the surface and the cross section, and there was a dent that was recognized as peeling of the carbon black.

[0079]

The rubber composition of the present invention exhibits the following effects. (1) Excellent mechanical strength. (2) Good abrasion resistance and heat resistance. (3) It has excellent oil resistance and cold resistance. (4) Good ozone resistance. (5) Excellent permanent elongation. Since the rubber composition of the present invention has not only the above-mentioned excellent properties but also good moldability, it can be used in various fields as described below. (1) Automotive parts such as boots and air intake hoses (2) Industrial parts such as packing and hoses (3) Coating materials such as electric wires (4) Gaskets and media materials for building materials.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 5: 3492 C08K 5: 3492 5:36 5:36 5:39 5:39 5:46 5:46 5:10) 5:10) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13/08

Claims (1)

(57) [Claims] (A) 100 parts by weight of a chlorinated ethylene polymer; (B) an oxide of a metal belonging to Group II of the periodic table;
Substances, carbonates, carboxylates, silicates, borates and
Oxidation of phosphites and metals of group IVb of the periodic table
Substance, basic carbonate, basic carboxylate, basic phosphorous acid
Acid salts, basic sulphite and tribasic sulphates and c
Metallization as an acid acceptor selected from the hydrotalcite group
1.0 to 15 parts by weight of a compound; (C) 5 to 100 parts by weight of carbon black whose structure according to oil absorption is 150 ml / 100 g or less; and (D) an organic sulfur compound represented by the formula (I). 5 to 10 parts by weight, R ₁ —S—CH ₂ —CH ₂ —COOH (I) (in the formula, R ₁ represents a linear alkyl group having at most 18 carbon atoms.) (E) General formula Is an amine salt of mercaptobenzothiazole represented by the formula (II) or an amine salt of dithiocarbamic acid represented by the formula (III): 1.0 to 10 parts by weight; (Wherein, R ₂ , R ₃ and R ₄ may be the same or different and are hydrogen or a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom) Or R ₂ , R ₃ and R ₄ may be bonded to each other to form a hydrocarbon ring, and may be further bonded to each other via a heteroatom to form a heterocyclic ring. There is no such thing.) (Wherein, R ₅ and R ₆ may be the same or different and are a hydrocarbon group having at most 18 carbon atoms, but a group having no substituent containing a hetero atom, or R ₅ and R ₆ R ₆ may combine with each other to form a hydrocarbon ring,
Further, they may be bonded via a hetero atom to form a heterocyclic ring. (F) a mercaptotriazine compound represented by the general formula (IV): 0.01 to 5.0 parts by weight; Wherein R ₇ is selected from the group consisting of a mercapto group and an amino group. (G) A chlorinated ethylene rubber composition comprising 5 to 50 parts by weight of a plasticizer for a polyvinyl chloride resin.