JP2002179853A - Olefin-based thermoplastic elastomer composition having excellent injection moldability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low-hardness olefin-based thermoplastic elastomer composition having excellent fluidity and providing an injection molding having excellent appearance and touch. SOLUTION: This thermoplastic elastomer composition is obtained by dynamically heat-treating a mixture comprising (A) 5-60 pts.wt. of a polypropylene resin having 1-50 [g/10 minutes] melt flow rate measured under conditions at 2.16 kg load at 230 deg.C in the manner described in ASTM D1238, (B) 40-95 pts.wt. of an ethylene-based copolymer rubber and (C) 0-50 pts.wt. of a softener (the total amount of the components (A), (B) and (C) is 100 pts.wt.) in the presence of a crosslinking agent to give an olefin-based thermoplastic elastomer (I) and compounding 100 pts.wt. of the olefin-based thermoplastic elastomer with (D) 1-30 pts.wt. of a polyolefin resin, (E) 0-30 pts.wt. of an olefinic copolymer rubber and (F) 0-50 pts.wt. of a softener.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition, and more particularly to a low-hardness thermoplastic elastomer composition having excellent injection moldability.

[0002]

2. Description of the Related Art Conventionally, soft vinyl chloride resin has been mainly used for interior skin materials such as instrument panels and door trims of automobiles. However, in recent years, olefin thermoplastic elastomers have been used from the viewpoint of weight reduction of materials. It is starting to be used. When these interior skins are manufactured from a skin raw material previously processed into a sheet shape, they are integrated with the aggregate by a method such as vacuum molding, injection press molding, or lamination. Since the manufacturing process is lengthened, the cost as a component is increased.

[0003] As a molding method capable of suppressing costs, after molding a base material by injection molding, a mold is moved to form a gap with the mold surface on the base material surface, and a skin material is injected there. A molding method is conceivable. However, it is difficult to mold a large-sized part of a conventional olefin-based thermoplastic elastomer with a material having a low hardness because of insufficient fluidity. On the other hand, since high fluidity materials generally have high hardness, it is not possible to obtain a skin layer having cushioning properties. Therefore, high fluidity, medium to low hardness materials have been demanded.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer composition having high fluidity, low hardness and excellent injection moldability in view of the above-mentioned circumstances.

[0005]

Means for Solving the Problems The present inventors added a certain component to an olefin-based thermoplastic elastomer produced by dynamic crosslinking to obtain a thermoplastic resin having low hardness and excellent fluidity. They have found that an elastomer composition can be obtained, and have completed the present invention.

That is, the present invention includes the following inventions. (1) (A) Load according to ASTM D1238.
The melt flow rate measured under the conditions of 16 kg and a temperature of 230 ° C. is 5 to 60 parts by weight of a polypropylene resin having a melt flow rate of 1 to 50 [g / 10 minutes], and (B) an ethylene copolymer rubber 40
-95 parts by weight, and (C) a mixture comprising 0-50 parts by weight of a softener (the total amount of components (A), (B) and (C) is 100 parts by weight) in the presence of a crosslinking agent. (D) 1 to 30 parts by weight of a polyolefin resin, (E) 0 to 30 parts by weight of an olefin copolymer rubber, based on 100 parts by weight of the olefinic thermoplastic elastomer (I) obtained by heat-treating
And (F) a thermoplastic elastomer composition obtained by adding 0 to 50 parts by weight of a softening agent. (2) The thermoplastic elastomer composition according to the above (1), wherein the crosslinking agent used in producing the olefin-based thermoplastic elastomer (I) is an organic peroxide. (3) Load 2.16k according to ASTM D1238
g, the melt flow rate measured under the conditions of a temperature of 230 ° C. is 1 to 50 [g / 10 minutes], and the JIS K625
3. The thermoplastic elastomer composition according to the above (1) or (2), wherein the durometer hardness measured according to No. 3 is 85A or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The thermoplastic elastomer composition of the present invention comprises (A) A
According to STM D1238, the melt flow rate measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. is 1 to
A mixture containing 50 g / 10 minutes of a polypropylene resin, (B) an ethylene copolymer rubber, and, if necessary, (C) a softening agent is dynamically heat-treated in the presence of a crosslinking agent. For the obtained olefinic thermoplastic elastomer (I), (D) a polyolefin resin and, if necessary, (E)
It is obtained by mixing an olefin-based copolymer rubber and, if necessary, (F) a softener.

[(A) Polypropylene resin] The polypropylene resin used in the present invention is a polymer containing propylene as a main component. For example, (1) propylene homopolymer, (2) propylene and 10 mol% or less. A random copolymer with α-olefins other than propylene, and (3) a block copolymer of propylene with 30 mol% or less of α-olefins other than propylene are exemplified. As the α-olefin other than propylene, for example, ethylene, 1-
Butene, 4-methyl-1-pentene, 1-hexene, 1
-Octene and the like. These α-olefins may be used alone or in combination of two or more in the polymer. (A) The polypropylene resin can be used alone or in combination of two or more.

The above (A) polypropylene resin has a load of 2.16 kg according to ASTM D1238 in that a thermoplastic elastomer composition to be subjected to injection molding is obtained.
Melt flow rate measured at a temperature of 230 ° C (M
FR) is 1 to 50 [g / 10 min], and further 5 to 4 g
It is preferably in the range of 0 [g / 10 minutes].

In the composition of the present invention, the content of the polypropylene resin (A) is determined by the following: (A) the polypropylene resin which is a component of the dynamically crosslinked olefinic thermoplastic elastomer, and (B) the ethylene copolymer described below. Rubber and (C)
It is 5 to 60 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the total amount of the softener ((A) + (B) + (C)). When the (A) polypropylene resin is used in the above range, an olefin-based thermoplastic elastomer (I) capable of providing a thermoplastic elastomer composition having excellent injection moldability and tactile sensation is obtained.

[(B) Ethylene copolymer rubber] The (B) ethylene copolymer rubber used in the present invention is an elastic copolymer mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms. Amorphous rubber, preferably an amorphous random elastic copolymer rubber composed of ethylene and an α-olefin having 3 to 20 carbon atoms, and an amorphous rubber composed of ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated diene A random elastic copolymer rubber may be used.

Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, and 3-methyl-1- Penten, 4-methyl-1-pentene, 5-methyl-1-hexene and the like can be mentioned.
These α-olefins are used alone or in combination of two or more. (B) The molar ratio of ethylene to an α-olefin having 3 to 20 carbon atoms in the ethylene copolymer rubber is usually 55 /
45 to 90/10, preferably 60/40 to 85
/ 15.

As the non-conjugated diene, specifically,
Examples thereof include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene (for example, 5-methylene-2-norbornene), and ethylidene norbornene (for example, 5-ethylidene-2-norbornene).

An amorphous random elastic copolymer rubber comprising ethylene and an α-olefin having 3 to 20 carbon atoms, and an amorphous random elastic rubber comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated diene. The Mooney viscosity [ML _{1 + 4} (100 ° C.)] of the copolymer rubber is preferably from 10 to 250, and particularly preferably from 30 to 150. In the amorphous random elastic copolymer rubber comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated diene, the iodine value is preferably 25 or less.

In the composition of the present invention, the content of (B) the ethylene copolymer rubber is determined by adjusting the content of (A) a polypropylene resin and (B) an ethylene copolymer which are components of a dynamically crosslinked olefin thermoplastic elastomer. Total amount of polymer rubber and (C) softener described below ((A) + (B) + (C)) 10
40 to 95 parts by weight, preferably 40 to 95 parts by weight, based on 0 parts by weight
85 parts by weight. When the ethylene-based copolymer rubber (B) is used in the above range, an olefin-based thermoplastic elastomer (I) which can provide a thermoplastic elastomer composition having excellent injection moldability and tactile sensation is obtained.

In the present invention, in addition to (B) the ethylene copolymer rubber, a rubber other than (B) the ethylene copolymer rubber may be used as the rubber component within a range not to impair the object of the present invention. For example, styrene-butadiene rubber, styrene-isoprene rubber, nitrile rubber and hydrogenated products thereof,
Butyl rubber, natural rubber, silicone rubber and the like can be used. Here, the “hydrogenated product” refers to a product obtained by performing a hydrogenation treatment to saturate all or a part of the double bond.

[(C) Softener] In the present invention,
(C) A softener can be used if necessary. The softening agent may be oil-extended to the (B) ethylene-based copolymer rubber or may be added later without oil-extending. As a softener,
Softeners commonly used for rubber can be used. Specifically, petroleum softening agents such as process oil, lubricating oil, paraffin oil, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, petrolatum; coal tar softening agents such as coal tar and coal tar pitch; castor oil , Linseed oil, rapeseed oil, soybean oil,
Fatty oils such as coconut oil; tall oil; beeswax, carnauba wax,
Waxes such as lanolin; ricinoleic acid, palmitic acid, stearic acid, oleic acid, erucic acid, barium stearate, calcium stearate, zinc laurate and other fatty acids or metal salts thereof; terpene resins, petroleum resins, cumarone indene resins, Synthetic polymer substances such as atactic polypropylene; ester softeners such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate; microcrystalline wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, hydrogenated liquid polybutadiene, liquid thiocol, etc. Is mentioned.

As the softener (C) used in the present invention, among the softeners (C), a process oil, particularly a paraffin-based process oil, is preferred. In the composition of the present invention, the content of the softener (C) is a component of the dynamically crosslinked olefinic thermoplastic elastomer (A).
Total amount of polypropylene resin, (B) ethylene copolymer rubber and (C) softener ((A) + (B) + (C)) 1
0 to 50 parts by weight, preferably 5 to 4 parts by weight, per 100 parts by weight.
0 parts by weight. (C) When the softener is used in the above range,
Olefinic thermoplastic elastomer which can provide a thermoplastic elastomer composition having excellent injection moldability and tactile sensation (I)
Is obtained.

Olefinic thermoplastic elastomer (I)
Contains, in addition to the above components, additives such as heat stabilizers, antiaging agents, weathering stabilizers, antistatic agents, coloring agents, lubricants, etc., as necessary, within a range not to impair the purpose of the present invention. be able to. In the production of the thermoplastic elastomer (I), the above-mentioned (A) polypropylene resin, (B) an ethylene-based copolymer rubber, (C) a softener, and if necessary, the above-mentioned additives are blended in the above-mentioned specific ratio. And a method of crosslinking. The crosslinking of the thermoplastic elastomer (I)
It is preferably carried out with an organic peroxide, ie by a dynamic heat treatment in the presence of the organic peroxide.

As the organic peroxide, specifically,
Dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5
-Di- (tert-butylperoxy) hexyne-3,
1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-
Butyl-4,4-bis (tert-butylperoxy)
Valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate,
tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butyl cumyl peroxide and the like.

Of these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5-dimethyl-2,5 are preferable in terms of odor and scorch stability.
-Di- (tert-butylperoxy) hexyne-3,
1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-
Butyl-4,4-bis (tert-butylperoxy)
Valerate is preferred. Among them, 1,3-bis (ter
t-butylperoxyisopropyl) benzene, 2.5
-Dimethyl-2,5-di- (tert-butylperoxy) hexane is particularly preferred.

The compounding amounts of the organic peroxide are (A) a polypropylene resin, (B) an ethylene copolymer rubber and (C)
0.02 to 2 parts by weight, preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the total amount of the softener ((A) + (B) + (C)).
1 part by weight. When the amount of the organic peroxide is within the above range, an olefin-based thermoplastic elastomer (I) capable of providing a thermoplastic elastomer composition having excellent injection moldability and tactile sensation can be obtained.

In the crosslinking treatment with the organic peroxide,
Sulfur: p-quinone dioxime, p, p'-dibenzoylquinone dioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane, N, N'-m-phenylene Peroxy crosslinking aids such as maleimide; or divinylbenzene; triallyl cyanurate; polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate; or vinyl Polyfunctional vinyl monomers such as butyrate and vinyl stearate may be blended. These components may be used alone or in combination of two or more. In the crosslinking treatment with an organic peroxide, the use of the compound allows the crosslinking reaction to proceed uniformly and gently.

Of the above compounds, divinylbenzene is particularly preferred. Divinylbenzene is easy to handle, has good compatibility with (A) a polypropylene resin and (B) an ethylene copolymer rubber, which are the main components of the object to be crosslinked, and acts as a dispersant for organic peroxides. Therefore, an olefin-based thermoplastic elastomer (I) which has a homogeneous crosslinking effect by heat treatment, is excellent in balance with fluidity, and can provide a thermoplastic elastomer composition excellent in injection moldability and tactile sensation is obtained.

Compounds such as the above-mentioned cross-linking aids or polyfunctional vinyl monomers are (A) polypropylene resin,
5 parts by weight or less, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the total amount of (B) the ethylene copolymer rubber and (C) the softener ((A) + (B) + (C)). It is used in such an amount as to give parts by weight. When the compounding amount of the compound such as the crosslinking aid or the polyfunctional vinyl monomer is in the above range, the compound such as the crosslinking aid or the polyfunctional vinyl monomer remains unreacted in the obtained thermoplastic elastomer (I). Since there is no residual, there is no change in physical properties due to heat history during work forming.

The above-mentioned dynamic heat treatment is carried out by kneading the above components in a molten state in the presence of an organic peroxide. This dynamic heat treatment is performed using a kneading device such as a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader, etc.), a single-screw or twin-screw extruder, but may be performed in a non-open kneader. preferable. The dynamic heat treatment is preferably performed in an inert gas such as nitrogen. Each component may be separately put into the kneading device, but may be put in the kneading device after mixing a part thereof, or may be put after mixing all of them.

The kneading is preferably carried out at a temperature at which the half-life of the organic peroxide used is less than 1 minute. That is, the kneading temperature is preferably from 150 to 280 ° C, particularly from 170 to 240 ° C.
C is preferred. The kneading time is 1 to 20 minutes, especially 1 to 5 minutes.
Minutes are preferred. The shearing force applied at the time of kneading is usually 10 to 10 ⁴ sec ⁻¹ , especially 10 ² at a shear rate.
It is preferably in the range of 〜１０10 ⁴ sec ⁻¹ .

[(D) Polyolefin resin] The (D) polyolefin resin, which is an essential component of the present invention, is a polymer of olefin, for example, a homopolymer of α-olefin or a copolymer of two or more α-olefins. And copolymers. Specifically, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-
Decene, 4-methyl-1-pentene, 3-methyl-1-
Examples include α-olefin homopolymers or copolymers such as pentene. Among these, a polyolefin resin composed of a homopolymer of ethylene, propylene or 1-butene, or a copolymer containing two or three of ethylene, propylene and 1-butene as main components is particularly preferable.

Specific examples include the following polyolefin resins. (1) ethylene and less than 10 mol% of α other than ethylene
-Random copolymer with olefin (1 ′) block copolymer of ethylene and less than 30 mol% of α-olefin other than ethylene (2) propylene and less than 10 mol% of α-olefin other than propylene (2 ′) Block copolymer of propylene and less than 30 mol% of α-olefins other than propylene (3) 1-butene and less than 10 mol% of α-olefins other than 1-butene Block copolymer of (3 ′) 1-butene and less than 30 mol% of α-olefins other than 1-butene Further, as the polyolefin resin (D), ASTM
According to D1238, the melt flow rate (MFR) measured under the condition of a load of 2.16 kg and a temperature of 230 ° C. is 5 to 5.
It is preferably 200 [g / 10 min], especially 10 to 10 g
More preferably, it is 150 [g / 10 minutes].

The polyolefin resin may be used alone or
You may mix and use more than one kind. In the composition of the present invention, the content of the polyolefin resin (D) is 1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the olefin-based thermoplastic elastomer (I). . When the content of the polyolefin resin (D) is in the above range, a thermoplastic elastomer composition having excellent injection moldability and tactile sensation can be obtained.

[(E) Olefin-based copolymer rubber] In the present invention, (E) olefin-based copolymer rubber can be added as needed. As the olefin copolymer rubber (E), a copolymer rubber containing an α-olefin as a main component, preferably an amorphous random elastic copolymer rubber can be used.

As such an amorphous random elastic copolymer rubber, for example, two or more kinds of α-C 2-20
Α-olefin copolymers composed of olefins. Specific examples include the following olefin copolymer rubbers. The α-olefin in the following copolymer rubbers (1) to (3) is an α-olefin having 2 to 20 carbon atoms. (1) α-olefin random copolymer rubber other than ethylene / ethylene [α / olefin other than ethylene / ethylene (molar ratio) = 90/10 to 50/50] (2) α-olefin random other than propylene / propylene Copolymer rubber [α other than propylene / propylene
-Olefin (molar ratio) = 90/10 to 50/50] (3) 1-butene / 1-butene other than α-olefin random copolymer rubber [1-butene / 1-butene other than α
-Olefin (molar ratio) = 90/10 to 50/50] As the α-olefin, specifically, ethylene,
Propylene, 1-butene, 4-methyl-1-pentene,
Examples include 1-hexene and 1-octene.

The olefin copolymer rubber (E) of the above (1) to (3) has a melt flow rate of 0.16 kg at a load of 2.16 kg and a temperature of 190 ° C. according to ASTM D1238. ~ 80 [g / 10 min], especially 0.
It is preferably in the range of 3 to 60 [g / 10 minutes]. The (E) olefin copolymer rubber is used alone or
Two or more kinds may be used in combination.

In the composition of the present invention, the content of the olefin copolymer rubber (E) is from 0 to 30 based on 100 parts by weight of the olefin thermoplastic elastomer (I).
Parts by weight, preferably 0 to 20 parts by weight.
When the content of the olefin copolymer rubber (E) is in the above range, a thermoplastic elastomer composition having excellent injection moldability and tactile sensation can be obtained.

[(F) Softener] In the present invention,
(F) A softener can be used if necessary.
As the softener (F), a softener usually used for rubber can be used. Specifically, process oil, lubricating oil, paraffin oil, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt,
Petroleum softeners such as petrolatum; coal tar softeners such as coal tar and coal tar pitch; fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil, coconut oil; tall oil;
Waxes such as beeswax, carnauba wax and lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, oleic acid, erucic acid, barium stearate, calcium stearate and zinc laurate or metal salts thereof; terpene resins, petroleum resins, Synthetic polymer substances such as coumarone indene resin and atactic polypropylene; ester softeners such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate; microcrystalline wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, hydrogenated liquid Examples thereof include polybutadiene and liquid thiochol. As the (F) softener, a process oil, particularly a paraffin-based process oil, is preferable among the above-mentioned (F) softeners.

In the composition of the present invention, the content of the softener (F) is 0 to 50 parts by weight based on 100 parts by weight of the olefinic thermoplastic elastomer (I).
Preferably it is 0 to 30 parts by weight. When the content of the softener (F) is in the above range, a thermoplastic elastomer composition having excellent injection moldability and tactile sensation can be obtained. In the thermoplastic elastomer composition of the present invention, in addition to the above components, as long as the object of the present invention is not impaired, if necessary, a heat stabilizer, an antioxidant, a weather stabilizer, an antistatic agent, a coloring agent, Additives such as lubricants can be blended.

The thermoplastic elastomer composition of the present invention comprises:
The olefin-based thermoplastic elastomer (I),
(D) polyolefin resin, and if necessary (E)
The olefin copolymer rubber and the (F) softener are blended in the above-mentioned specific ratio, and other additives are blended if necessary, and a dynamic heat treatment is performed in the absence of an organic peroxide. It is preferred to manufacture by.

The dynamic heat treatment can be performed by kneading the above components in a molten state. The dynamic heat treatment is performed using a kneading device such as a mixing roll, an intensive mixer (eg, Banbury mixer, kneader, etc.), a single-screw or twin-screw extruder, but is preferably performed in a non-open kneading device. . The dynamic heat treatment is preferably performed in an inert gas such as nitrogen. Each component may be separately put into the kneading device, but may be put in the kneading device after mixing a part thereof, or may be put after mixing all of them.

The kneading temperature is preferably from 150 to 280 ° C., particularly preferably from 170 to 240 ° C. The kneading time is 1
-20 minutes are preferable, and 1-5 minutes are especially preferable. The shearing force applied during kneading is usually 1 at the shear rate.
It is preferably in the range of 0 to 10 ⁴ sec ^-1 , particularly preferably in the range of 10 ² to 10 ⁴ sec ^-1 .

A of the thermoplastic elastomer composition of the present invention
The melt flow rate measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. according to STM D1238 is preferably 1 to 50 [g / 10 minutes], and more preferably 1.2.
To 50 g / 10 min, particularly preferably 2 to 50 g / min.
10 minutes]. Further, the durometer hardness of the thermoplastic elastomer composition of the present invention measured according to JIS K6253 is preferably 85A or less, more preferably 80A or less.

By setting the melt flow rate and the hardness of the thermoplastic elastomer composition of the present invention in the above ranges, it is possible to obtain a product having good appearance, flexibility and tactile sensation of an injection molded product. The composition of the present invention is an optional component of (A) a polypropylene resin, (B) an ethylene-based copolymer rubber, and a thermoplastic elastomer (I) which are components of the olefin-based thermoplastic elastomer (I). C) a softener, and a composition containing (D) a polyolefin resin, and (E) an olefin-based copolymer rubber and (F) a softener which are added as necessary. Inorganic filler can be contained.

Examples of the inorganic filler include glass fiber, potassium titanate fiber, carbon fiber, calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, alumina, barium sulfate, calcium sulfate, Examples include magnesium carbonate, molybdenum disulfide, graphite, glass beads, and shirasu balloon.

In the composition of the present invention, the compounding amount of the inorganic filler is olefinic thermoplastic elastomer (I),
0 to 300 parts by weight per 100 parts by weight of the thermoplastic elastomer composition comprising (D) a polyolefin resin, optionally (E) an olefin-based copolymer rubber, and optionally (F) a softener. Preferably, more preferably 0 to
It is preferably 200 parts by weight, particularly preferably 0 to 100 parts by weight.

In the composition of the present invention, in addition to the above-mentioned components, if necessary, a heat-resistant stabilizer, an anti-aging agent, a weather-resistant stabilizer, an anti-static agent, a coloring agent, and the like, as long as the object of the present invention is not impaired.
Additives such as lubricants can be blended. The dynamic heat treatment may be performed simultaneously with the production of the thermoplastic elastomer composition, or may be performed after the production of the thermoplastic elastomer composition.

The components contained in the composition of the present invention can be blended in the above-mentioned general range, but it is most preferred that all the components are blended in a preferable range. However, it is also preferable that the content of a specific component is in a preferable range and the content of another component is in a general range.

As the above-mentioned components contained in the composition of the present invention, those having the above-mentioned physical property values in the above-mentioned general ranges can be used. it can. However, those having specific physical property values within a preferable range and other physical property values within a general range can also be used as preferable ones.

Since the composition of the present invention obtained has the above-mentioned constitution, it has good fluidity and excellent injection moldability, so that it can be used even in the case of producing a large injection molded product. The appearance of the obtained molded article is also good. Further, since the hardness is low, the feel of the obtained molded product is also good.

Further, since the composition of the present invention uses an olefin resin, it is lightweight and easy to recycle.
Moreover, since the olefin-based thermoplastic elastomer (I) used in the production of the composition of the present invention is crosslinked with an organic peroxide, the obtained thermoplastic elastomer composition of the present invention has more excellent heat resistance. . Therefore, the composition of the present invention can be widely and suitably used as an energy-saving and resource-saving type elastomer for injection molding in automobile interior parts, exterior parts, industrial machine parts, electric / electronic parts, building materials and the like.

[0049]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

The compounds used in the preparation of the compositions in the examples and comparative examples are shown below. (A) a polypropylene resin (A-1) a propylene / ethylene block copolymer;
Molar ratio of units derived from propylene to units derived from ethylene (propylene / ethylene) 85/15, M
FR (ASTM D1238, 230 ° C, 2.16 kg
(Load) 30 [g / 10 min] (B) Ethylene copolymer rubber (B-1) Ethylene propylene / 5-ethylidene-2
-Norbornene copolymer rubber; molar ratio of units derived from ethylene to units derived from propylene (ethylene / propylene) 78/22, iodine value 13, based on 5-ethylidene-2-norbornene, Mooney viscosity ML _{1 + 4}
(100 ° C.) 140 (C) Softener (C-1) Idemitsu Kosan Co., Ltd. paraffin-based process oil PW-380 (trade name)

[0051]Organic peroxide 1,3-bis (tert-butylperoxyisopropyl
Le) benzene(D) Polyolefin resin (D-1) a propylene / ethylene block copolymer;
Units derived from propylene and units derived from ethylene
Molar ratio to propylene (propylene / ethylene) 85/15, M
FR (ASTM D1238, 230 ° C, 2.16 kg
Load) 80 [g / 10 min](E) Olefin copolymer rubber (E-1) Ethylene / propylene copolymer rubber;
Of units derived from propylene and units derived from propylene
Molar ratio (ethylene / propylene) 80/20, MFR
(ASTM D1238, 190 ° C, 2.16kg load
Weight) 10 [g / 10 min] (E-2) Propylene / ethylene copolymer rubber;
Between units derived from ren and units derived from ethylene
Molar ratio (propylene / ethylene) 60/40, MFR
(ASTM D1238, 190 ° C, 2.16kg load
Weight) 1 [g / 10 min] (F) Softener (F-1) Idemitsu Kosan Co., Ltd. paraffin-based process oil
LE PW-380 (trade name)

(Example 1) [Production of olefinic thermoplastic elastomer (I)] 25 parts by weight of propylene / ethylene block copolymer (A-1) pellets and ethylene / propylene / 5-ethylidene-2-norbornene copolymer Combined rubber (B-1) 75
Parts by weight, 0.4 parts by weight of 1,3-bis (tert-butylperoxyisopropyl) benzene and 0.4 parts by weight of divinylbenzene were sufficiently mixed, and L / D = 4.
0, using a twin screw extruder having a screw diameter of 50 mm, and extruding at 220 ° C. in a nitrogen atmosphere. At this time, the paraffinic process oil (C-1) is mixed with a propylene / ethylene block copolymer (A-1) Propylene-5
-Ethylidene-2-norbornene copolymer rubber (B-
Side feed was performed so as to be 30 parts by weight with respect to 100 parts by weight in total of 1) to obtain pellets of the olefin-based thermoplastic elastomer (I) ((A-1) and (B-).
1) and the weight ratio of (C-1) (A-1) / (B-1) /
(C-1) = about 19/58/23).

[Production of Thermoplastic Elastomer Composition] 100 parts by weight of the obtained olefinic thermoplastic elastomer (I) pellets, 10 parts by weight of propylene / ethylene block copolymer (D-1) pellets, propylene / ethylene 10 parts by weight of the copolymer rubber (E-2) pellets are sufficiently mixed and extruded at 220 ° C. in a nitrogen atmosphere using the extruder. At this time, the paraffin-based process oil (F-1) is Side feed was performed so as to be 10 parts by weight with respect to 100 parts by weight of the olefin-based thermoplastic elastomer (I) to obtain pellets of the thermoplastic elastomer composition.

[Evaluation of Thermoplastic Elastomer Composition] Measurement of Durometer Hardness The durometer hardness of the obtained thermoplastic elastomer composition was measured according to JIS K6253. Table 1 shows the results.

Measurement of Melt Flow Rate The melt flow rate of the obtained thermoplastic elastomer composition was measured under a load of 2.16 according to ASTM D1238.
The measurement was performed under the conditions of kg and a temperature of 230 ° C. Table 1 shows the results.

Evaluation of injection moldability The obtained thermoplastic elastomer composition was subjected to a mold clamping pressure of 20
0 tons of injection molding machine hopper, resin temperature 22
At 0 ° C., injection molding was performed through a pin gate in a 350 mm × 350 mm × 1 mm cavity. The appearance and feel of the obtained molded product were evaluated according to the following criteria.

[Evaluation Criteria] Injection moldability (appearance) ：: good, Δ: slightly poor, ×: poor (poor filling, flow mark, etc.) Tactile ：: good (soft feeling), Δ: slightly poor (somewhat hard) ), ×: Poor (has a hard feeling) Table 1 shows the evaluation results.

(Example 2) [Production of olefin-based thermoplastic elastomer (I)] An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 1. [Production of a thermoplastic elastomer composition] Pellets of a thermoplastic elastomer composition were obtained in the same manner as in Example 1 except that the paraffin-based process oil (F-1) was not fed. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Example 3) [Production of olefin-based thermoplastic elastomer (I)] An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 1. [Production of a thermoplastic elastomer composition] The same procedure as in Example 2 was repeated except that the ethylene-propylene copolymer rubber (E-1) was used instead of the propylene-ethylene copolymer rubber (E-2). A pellet of the plastic elastomer composition was obtained. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Example 4) [Production of olefin-based thermoplastic elastomer (I)] An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 1. [Production of thermoplastic elastomer composition] Propylene / ethylene block copolymer (D-1) was 5 parts by weight,
Pellets of a thermoplastic elastomer composition were obtained in the same manner as in Example 2 except that the propylene / ethylene copolymer rubber (E-2) was not used. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Example 5) [Production of olefinic thermoplastic elastomer (I)] Propylene / ethylene block copolymer (A-1)
0 parts by weight of ethylene / propylene / 5-ethylidene-
Olefinic thermoplastic elastomer (I) in the same manner as in Example 1 except that 80 parts by weight of 2-norbornene copolymer rubber (B-1) was used and side feed of paraffinic process oil (C-1) was not performed. Was manufactured. [Production of thermoplastic elastomer composition] The procedure of Example 1 was repeated except that the propylene / ethylene copolymer rubber (E-2) was used in 15 parts by weight and the paraffin-based process oil (F-1) was used in 15 parts by weight. Thus, pellets of the thermoplastic elastomer composition were obtained. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Example 6) [Production of olefinic thermoplastic elastomer (I)] Propylene / ethylene block copolymer (A-1)
0 parts by weight of ethylene / propylene / 5-ethylidene-
An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 5 except that the amount of the 2-norbornene copolymer rubber (B-1) was changed to 70 parts by weight. [Production of thermoplastic elastomer composition] Pellets of a thermoplastic elastomer composition were obtained in the same manner as in Example 1 except that 5 parts by weight of the propylene / ethylene block copolymer (D-1) was used. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Comparative Example 1) [Production of olefin-based thermoplastic elastomer (I)] An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 1. [Production of thermoplastic elastomer composition] Pellets of a thermoplastic elastomer composition were obtained in the same manner as in Example 3 except that the propylene / ethylene block copolymer (D-1) was not used. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Comparative Example 2) [Production of olefin-based thermoplastic elastomer (I)] An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 6. [Production of thermoplastic elastomer composition] Propylene / ethylene block copolymer (D-1), ethylene / propylene copolymer rubber (E-1), propylene / ethylene copolymer rubber (E-2), paraffin-based process oil None of (F-1) was used. [Evaluation of Thermoplastic Elastomer Composition] A durometer hardness and a melt flow rate were measured in the same manner as in Example 1 using pellets of the olefin-based thermoplastic elastomer (I) as the thermoplastic elastomer composition. The appearance and feel of the molded article were evaluated. Table 1 shows the results.

Comparative Example 3 Production of Olefin-Based Thermoplastic Elastomer (I) An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 6. [Production of thermoplastic elastomer composition] Pellets of a thermoplastic elastomer composition were obtained in the same manner as in Example 2 except that the propylene / ethylene block copolymer (D-1) was not used. [Evaluation of Thermoplastic Elastomer Composition] The durometer hardness and the melt flow rate of the obtained thermoplastic elastomer composition were measured in the same manner as in Example 1, and the appearance and touch of the molded product obtained by injection molding were evaluated. did. Table 1 shows the results.

(Comparative Example 4) [Production of olefin-based thermoplastic elastomer (I)] Propylene / ethylene block copolymer (A-1)
5 parts by weight of ethylene / propylene / 5-ethylidene-
An olefin-based thermoplastic elastomer (I) was produced in the same manner as in Example 5 except that the 2-norbornene copolymer rubber (B-1) was used in an amount of 65 parts by weight. [Production of thermoplastic elastomer composition] Propylene / ethylene block copolymer (D-1), ethylene / propylene copolymer rubber (E-1), propylene / ethylene copolymer rubber (E-2), paraffin-based process oil None of (F-1) was used. [Evaluation of Thermoplastic Elastomer Composition] A durometer hardness and a melt flow rate were measured in the same manner as in Example 1 using pellets of the olefin-based thermoplastic elastomer (I) as the thermoplastic elastomer composition. The appearance and feel of the molded article were evaluated. Table 1 shows the results.

[0067]

[Table 1]

[0068]

The thermoplastic elastomer composition of the present invention is excellent in fluidity and not high in hardness, so that an injection molded article having good appearance and touch can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29K 23:00 B29K 23:00 (72) Inventor Akira Uchiyama 3 Chikatsukaigan 3 Ichihara-shi, Chiba Mitsui Chemicals Co., Ltd. Kai-house F-term (reference) 4F206 AA04 AA11 AA45 JA07 JF02 JQ81 4J002 AC03Y AE03Y AE04Y AE05Y AG00Y BA01Y BB03Z BB05U BB05X BB05Z BB12W BB12Z BB13Y BB14U BB14W BB14Z BB15U BB15W BB15X BB17U BB17Z BB18U BP02W EF056 EG016 EH096 EH146 EK037 EK047 EK057 EK067 FD02Y FD026 FD147 GN00

Claims (3)

[Claims] (A) According to ASTM D1238,
Melt flow rate measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. is 5 to 60 parts by weight of a polypropylene resin having a melt flow rate of 1 to 50 g / 10 minutes, and (B) 40 to 95 parts by weight of an ethylene copolymer rubber. , And (C) a mixture comprising 0 to 50 parts by weight of a softening agent (the total amount of components (A), (B) and (C) is 100 parts by weight), and dynamically heat-treated in the presence of a crosslinking agent. Obtained olefinic thermoplastic elastomer (I)
(D) polyolefin resin 1-3 based on 100 parts by weight
A thermoplastic elastomer composition obtained by adding 0 parts by weight, (E) 0 to 30 parts by weight of an olefin copolymer rubber, and (F) 0 to 50 parts by weight of a softening agent. 2. The thermoplastic elastomer composition according to claim 1, wherein the crosslinking agent used in producing the olefin-based thermoplastic elastomer (I) is an organic peroxide. 3. The melt flow rate measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. according to ASTM D1238 is 1 to 50 g / 10 min.
The durometer hardness measured according to K6253 is 85
The thermoplastic elastomer composition according to claim 1, wherein the composition is A or less.