JP2002138171A - Thermoplastic elastomer composition - Google Patents

Abstract

(57) Abstract: An olefin resin and an ethylene-α-olefin copolymer rubber are contained as polymer components.
Provided is a thermoplastic elastomer composition which maintains rubber-like properties such as elasticity, heat resistance and tensile properties, and various properties such as tensile strength at a satisfactory level, and does not cause undesired coloration such as yellow in a product. SOLUTION: It contains the following components (A) to (D),
The content of (A) is 5 to 50 parts by weight, the content of (B) is 50 to 95 parts by weight (provided that the total of (A) and (B) is 100 parts by weight), The content of (C) is 0.001 to 5 parts by weight per 100 parts by weight of the total amount of (A) and (B), and the content of (D) is 0.0
A thermoplastic elastomer composition obtained by subjecting a composition of 1 to 5 parts by weight to dynamic heat treatment. (A) Olefin-based resin (B) Ethylene-α-olefin-based copolymer rubber (C) Organic peroxide (D) Compound represented by the following formula (I) and / or (II) (R1 to R6 independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoplastic elastomer composition. More specifically, the present invention includes an olefin resin and an ethylene-α-olefin copolymer rubber as polymer components,
The present invention relates to a thermoplastic elastomer composition which maintains rubber properties such as heat resistance and tensile properties, and various properties such as tensile strength at a satisfactory level, and does not cause an undesired coloration such as yellow in a product.

[0002]

2. Description of the Related Art Thermoplastic elastomers containing an olefin resin component and a rubber component are excellent in the operating temperature range, flexibility, heat resistance, light weight, processing characteristics, etc., and are used as substitutes for vulcanized rubber and vinyl chloride. It is widely used in fields such as automobile parts, various industrial parts, various civil engineering and building materials, medical parts, housings, OA parts, and miscellaneous goods. A bismaleimide compound represented by N, N'-m-phenylenebismaleimide is obtained by subjecting a dynamic heat treatment in the presence of an olefin resin, an olefin copolymer rubber, and an organic peroxide to an olefin thermoplastic resin. It is used to improve the flexibility, mechanical properties, compression set and the like of the elastomer. However, these bismaleimide compounds have a problem in that undesired coloration such as yellow color is produced in products.

[0003]

Under these circumstances, an object of the present invention is to provide an olefin resin and an ethylene-.alpha.-olefin copolymer rubber as polymer components, and to provide appearance, elasticity and heat resistance. , Maintaining rubber-like properties such as tensile properties and various properties such as tensile strength at a satisfactory level,
Another object of the present invention is to provide a thermoplastic elastomer composition having no undesired coloration such as yellow in a product.

[0004]

That is, the present invention comprises the following components (A) to (D), wherein the content of (A) is 5
To 50 parts by weight, and the content of (B) is 50 to 95 parts by weight (provided that the total of (A) and (B) is 100 parts by weight), and that (A) and (B) A composition having a content of (C) of 0.001 to 5 parts by weight and a content of (D) of 0.01 to 5 parts by weight per 100 parts by weight in total is obtained by dynamic heat treatment. The present invention relates to a thermoplastic elastomer composition. (A) Olefin resin (B) Ethylene-α-olefin copolymer rubber (C) Organic peroxide (D) Compound represented by the following formula (I) and / or (II) (R1 to R6 independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.)

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) of the present invention is an olefin resin. Examples of the olefin resin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,
Homopolymers or copolymers such as decene are exemplified, and among them, polypropylene is preferable.

[0006] Polypropylene is a known polymer and is polymerized by a known polymerization method. When polymerizing propylene, an α-olefin such as ethylene, butene-1, pentene-1, or 4-methylpentene-1 may be copolymerized. As the three-dimensional structure, an isotactic structure is preferable, but a syndiotactic structure, a mixture of these structures, or a structure partially including an atactic structure can also be used. Polypropylene is a polymer mainly composed of propylene, and is a propylene homopolymer, a random copolymer or a block copolymer of propylene-α-olefin.

The melt flow rate of polypropylene (J
According to IS K6758, temperature 230 ° C, load 21.1
Measure at 8N. ) Is preferably 0.1 to 200 g / 10 min, more preferably 0.5 to 50 g / 10 min.
Minutes.

The component (B) of the present invention is an ethylene-α-olefin copolymer rubber.
α-olefin copolymer rubber and ethylene-α-olefin-non-conjugated diene copolymer rubber.

The above α-olefin includes, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like. preferable.
Examples of the non-conjugated diene include 1,4-hexadiene, dicyclopentadiene, and 5-ethylidene-2-
Norbornene and the like.

The ratio (weight ratio) of ethylene / α-olefin in (B) is usually 90/10 to 30/70. When the ethylene-α-olefin-non-conjugated diene copolymer rubber is used, the content of the non-conjugated diene is usually 5 to 40 in iodine value. The ethylene-α-olefin copolymer rubber and the ethylene-α-olefin-non-conjugated diene copolymer rubber may be used as a mixture. Note that any of oil-extended rubber and non-oil-extended rubber may be used. When using an oil-extended rubber, the content of the extender oil is 100 g of the copolymer rubber.
It is usually 20 to 200 parts by weight per part by weight.

Preferred specific examples of the ethylene-α-olefin copolymer rubber include an ethylene-propylene copolymer rubber having a weight ratio of ethylene / propylene of 85/15 to 45/55.

The ethylene-α-olefin copolymer rubber has a Mooney viscosity at 100 ° C. (ML _{1 + 4} 100 ° C.) of 1
It is preferably from 0 to 350, more preferably from 30 to 3
00. If the Mooney viscosity is too low, the mechanical strength may be poor, while if the Mooney viscosity is too high, the appearance of the molded article may be impaired.

The component (C) of the present invention is an organic peroxide, and as the organic peroxide, dicumyl peroxide, di-
t-butyl peroxide, 2,5-dimethyl-2,5-
Di- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-
3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy)
-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate,
Benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t
-Butylperoxybenzoate, t-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, t-butylcumyl peroxide and the like can be used.

The component (D) of the present invention is a compound represented by the following formula (I) and / or (II). (R1 to R6 independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.)

By using (D) of the present invention, it is possible to obtain a thermoplastic elastomer composition having no undesired coloring such as yellow in the product.

As a specific example of (D), the bismaleimide represented by the general formula (I) includes N, N '-(3,3'
-Dimethyl-4,4'-diphenylmethane) bismaleimide, N, N '-(3,3', 5,5'-tetramethyl-4,4'-diphenylmethane) bismaleimide,
N '-(3,3'-diethyl-4,4'-diphenylmethane) bismaleimide, N, N'-(3,3'-di-n-
Butyl-4,4'-diphenylmethane) bismaleimide, N, N '-(3,3'-diethyl-5,5'-dimethyl-4,4'-diphenylmethane) bismaleimide,
N, N '-(3,3', 5,5'-tetraethyl-4,
4'-diphenylmethane) bismaleimide, bis (3-
Ethyl-5-methyl-4-maleimidophenyl) methane and the like.

As a specific example of (D), the bismaleimide represented by the general formula (II) includes, for example, 2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis -[3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis-
[3-butyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis- [3,5-dimethyl-
4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis- [3-methoxy-4- (4-maleimidophenoxy) phenyl] propane, 1,1,1,
3,3,3, -Hexafluoro-2,2-bis- [4-
(4-maleimidophenoxy) phenyl] propane,
1,1,1,3,3,3-hexachloro-2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane, 1-phenyl-1-methyl-1,1-bis-
[4- (4-maleimidophenoxy) phenyl] methane, 1-phenyl-1-methyl-1,1-bis- [3,
5-dimethyl-4- (4-maleimidophenoxy) phenyl] methane, 2,2-bis- [4- (4-maleimidophenylthio) phenyl] propane and the like.

Of these, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane and 2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane are preferred.

The content of each component is as follows.
The content of (A) is 5 to 50 parts by weight, the content of (B) is 50 to 95 parts by weight (provided that the total of (A) and (B) is 100 parts by weight), The content of (C) per 100 parts by weight of the total amount of (A) and (B) is 0.001 to 5 parts by weight, and the content of (D) is 0.0
1 to 5 parts by weight. In addition, the amount of (B) when using oil-extended rubber is based on the amount including extended oil. Also,
When two or more components are used in combination for each component, the total amount is used as a reference.

If the amount of the component (A) is too small, the fluidity is reduced, resulting in poor appearance. On the other hand, if the component (A) is excessive, it becomes hard and does not exhibit elasticity. When the amount of the component (B) is too small, the composition does not exhibit elasticity. On the other hand, when the amount of the component (B) is too large, the fluidity is reduced and the appearance is poor. If the component (C) is too small, it takes time to obtain a sufficient degree of crosslinking of the olefin copolymer rubber, while if the component (C) is too large, the odor becomes strong, and As a result of the increase in the degree of cross-linking, the flowability of the entire composition decreases. If the amount of the component (D) is too small, the degree of crosslinking of the olefin-based copolymer rubber is too small. As a result, rubber properties such as heat resistance, tensile properties, elastic recovery and rebound resilience of the composition are not sufficient. If the component (D) is excessive, the elongation decreases.

The thermoplastic elastomer composition of the present invention comprises:
A thermoplastic elastomer composition obtained by subjecting the above (A) to (D) to dynamic heat treatment. As the dynamic heat treatment device, known devices such as an open-type mixing roll, a non-open-type Banbury mixer, a kneader, an extruder, and a twin-screw extruder can be used. The temperature and time of the dynamic heat treatment are such that the half-life of the organic peroxide used is less than 1 minute, usually 150 to 280 ° C, preferably 180 to 26 ° C.
It is 1 to 30 minutes at 0 ° C, preferably 3 to 20 minutes. In addition, at the time of the above kneading, if necessary, additives such as a flame retardant, an antistatic agent, a heat stabilizer, an antioxidant, a release agent, and a pigment may be used.

The thermoplastic elastomer composition of the present invention comprises:
It can be molded by a device used for ordinary thermoplastics, and is molded into various molded products by injection molding, extrusion molding, calender molding, blow molding and the like. Examples of molded articles include interior and exterior parts for automobiles such as various gaskets, packings, weather strips, various boots, grommets, civil engineering and construction-related materials, industrial parts, medical equipment, housings, OA parts, and miscellaneous goods. .

[0023]

Next, the present invention will be described by way of examples. Examples 1 and 2 and Comparative Example 1 The compositions in Tables 1 and 2 were kneaded using a Banbury mixer,
The obtained kneaded material was passed through a roll to form a sheet, and formed into square pellets with a sheet pelletizer. Next, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, which is a crosslinking agent, was added to 100 parts by weight of the square pellets.
8 parts by weight were uniformly mixed using a tumbler mixer for 10 minutes, and extruded at 200 ± 10 ° C. using a twin screw extruder to perform dynamic crosslinking, thereby obtaining a thermoplastic elastomer composition. Further, the thermoplastic elastomer composition is injection-molded at a cylinder temperature of 220 ° C. and a mold temperature of 50 ° C.
A test piece having a thickness of 50 mm × 90 mm × 2 mm was prepared, and physical properties were measured by the following methods. Table 1 shows the results. MFR: JIS K7250 (230 ° C, 98.07
N) Hardness: ASTM D2240 (Shore-A instantaneous value)
Breaking strength: in accordance with JIS K6251 (JIS No. 3 dumbbell, tensile speed 200 mm / min) Elongation at break: Same as above Compression set: in accordance with JIS K6262 (70 ° C., 22
Time, 25% compression) Hue: Based on JIS K7105 (yellowness)

[0024]

[Table 1] PP; homopolypropylene (melt flow rate = 1
2) EPDM; ethylene-propylene-5-ethylidene-2
-Norbornene copolymer rubber (ethylene / propylene weight ratio = 72/28, iodine value = 12, ML1 + 4100 ° C.)
= 53, oil extension = 100 PHR) BMI-70; bis (3-ethyl-5-methyl-4-maleimidophenyl) methane (manufactured by K-I Kasei Co., Ltd.) BMI-80; 2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane (manufactured by K-I Kasei Co., Ltd.) BM; N, N'-m-phenylenebismaleimide (manufactured by Sumitomo Chemical Co., Ltd.)

[0025]

As described above, according to the present invention, an olefin resin and an ethylene-α-olefin copolymer rubber are contained as polymer components, and rubber-like properties such as appearance, elasticity, heat resistance, and tensile properties, and tensile properties are obtained. It was possible to provide a thermoplastic elastomer composition which maintains various properties such as strength at a satisfactory level and does not cause undesired coloring such as yellow in the product.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F070 AA12 AA15 AA16 AC45 AC56 AC66 AE08 GA05 GB08 4J002 BB022 BB051 BB112 BB151 BB172 EK026 EK036 EK046 EK056 EK066 EK086 EU027 FD146 FD147 GB01 GC00 G0000

Claims (1)

[Claims] 1. It contains the following components (A) to (D),
The content of (A) is 5 to 50 parts by weight, the content of (B) is 50 to 95 parts by weight (provided that the total of (A) and (B) is 100 parts by weight), The content of (C) is 0.001 to 5 parts by weight per 100 parts by weight of the total amount of (A) and (B), and the content of (D) is 0.0
A thermoplastic elastomer composition obtained by subjecting a composition of 1 to 5 parts by weight to dynamic heat treatment. (A) Olefin resin (B) Ethylene-α-olefin copolymer rubber (C) Organic peroxide (D) Compound represented by the following formula (I) and / or (II) (R1 to R6 independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.)