JP2001316535A - Olefin-based thermoplastic elastomer composition having good fogging properties and interior automotive trim molded by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition capable of giving a molded product, especially an interior automotive trim, which has excellent fogging properties. SOLUTION: This olefin-based thermoplastic elastomer composition is obtained by dynamically subjecting a mixture comprising (A) an ethylenic copolymer rubber in an amount of 40-85 pts.wt., (B) an olefin-based resin in an amount of 60-15 pts.wt., and (C) a softener in an amount of <=45 pts.wt. [provided that, the total amount of the components (A) to (C) is 100 pts. wt.] to heat treatment in the presence of a crosslinking agent, wherein a glass plate which is subjected to the fogging test according to the A method for DIN 75201 at 100 deg.C for 3 hr by the use of 10 g of the pellets of the composition has a gloss value of >=80% and a haze value of <=10%. The molded product, especially the interior automotive trim, is molded by using the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin-based thermoplastic elastomer composition having excellent fogging properties and a molded product obtained by molding the same, particularly to an automobile interior part.

[0002]

2. Description of the Related Art Instrument panels of automobiles,
Conventionally, soft vinyl chloride resin has been mainly used for interior skin materials such as door trims, but in recent years, olefin-based thermoplastic elastomers have begun to be used from the viewpoint of lightening of materials. In the case of a passenger car, especially in a hot summer, the temperature inside the closed car becomes considerably high. However, especially, the skin of the instrument panel reaches a considerable temperature because it is exposed to direct sunlight through glass. In such a situation, fogging, that is, a phenomenon in which a low molecular weight volatile organic substance in the instrument panel skin volatilizes and sublimates at a high temperature and adheres to a windshield or the like to cloud the glass becomes a problem.

[0003] Although it is said that olefin-based thermoplastic elastomers have better fogging properties than conventionally used soft vinyl chloride, recently, windshields and the like tend to be large in passenger car designs. In addition, the temperature inside a closed car under the hot summer weather is increasing, and further improvement in fogging properties has been demanded.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer composition capable of providing a molded article having excellent fogging properties, particularly an automobile interior part, in view of the above-mentioned circumstances. .

[0005]

The present invention includes the following inventions. (1) 40 to 85 parts by weight of ethylene copolymer rubber (A), 60 to 15 parts by weight of olefin resin (B) and 45 parts by weight or less of softener (C) [Components (A), (B) and ( The total amount of C) is 100 parts by weight].
The gross value of the glass plate is 80% or more when the fogging test is performed at 100 ° C. for 3 hours based on the method A of DIN 75201 using the pellets, and the haze value is 1
An olefin-based thermoplastic elastomer composition having 0% or less.

(2) After the dynamic heat treatment, the following conditions are satisfied: Q ≧ 0.1 and t ≧ 2- ^{(T-110) / 10} (where Q is the weight per unit weight of the workpiece supplied during drying ⁾ The amount of hot air (m ³ / (time · kg)), t is the heat treatment time (hour), and T represents the temperature (° C.) of the hot air just before it hits the object to be processed. The thermoplastic elastomer composition according to the above (1). (3) The cross-linking agent is a bifunctional organic peroxide having two peroxide bonds in one molecule, and the concentration of the diol as a decomposition product remaining in the pellet is 30 pp.
m or less, wherein the thermoplastic elastomer composition is (1) or (2).

(4) A molded article obtained by molding the thermoplastic elastomer composition according to any one of (1) to (3). (5) The molded article according to (4), which is an automobile interior part. (6) Ethylene copolymer rubber (A) 40 to 85 parts by weight, olefin resin (B) 60 to 15 parts by weight and softener (C) 45 parts by weight or less [Components (A), (B) and ( The total amount of C) is 100 parts by weight]], and then dynamically heat-treated in the presence of a cross-linking agent, under the following conditions: Q ≧ 0.1 and t ≧ 2- ^{(T-110) / 10} (however, Q is the amount of hot air supplied per unit weight of the object to be processed during drying (m ³ / (time · kg)), t is the heat treatment time (hour), and T is the amount of hot air just before hitting the object to be processed. A method for producing an olefin-based thermoplastic elastomer composition, comprising statically heat-treating at a temperature (° C.).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The thermoplastic elastomer composition of the present invention is prepared by dynamically mixing a mixture containing an ethylene copolymer rubber (A), an olefin resin (B) and, if necessary, a softener (C) in the presence of a crosslinking agent. Obtained by heat treatment.

[Ethylene copolymer rubber (A)] The ethylene copolymer rubber (A) used in the present invention is an elastic copolymer mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms. And an amorphous random elastic copolymer rubber composed of ethylene and an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene composed of ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene. Examples include a regular random elastic copolymer rubber.

As the α-olefin, specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1 -Pentene, 4-methyl-1-
Pentene, 5-methyl-1-hexene and the like.
These α-olefins are used alone or in combination of two or more. The molar ratio of ethylene to the α-olefin having 3 to 20 carbon atoms in the ethylene copolymer rubber (A) is usually 55/45 to 85/15, preferably 60/40 to 83/17.

Specific examples of the non-conjugated polyene include dicyclopentadiene, cyclooctadiene, methylene norbornene (for example, 5-methylene-2-norbornene), and ethylidene norbornene (for example, 5-ethylidene-2-norbornene). Cyclic dienes such as, methyltetrahydroindene, 5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropylenyl-2-norbornene and norbornadiene; 1,4-hexadiene; Methyl-
1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 6-methyl-1,6-
Octadiene, 7-methyl-1,6-octadiene, 6
-Ethyl-1,6-octadiene, 6-propyl-1,
6-octadiene, 6-butyl-1,6-octadiene, 6-methyl-1,6-nonadiene, 7-methyl-
1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 6-methyl-
Chain dienes such as 1,6-decadiene, 7-methyl-1,6-decadiene, 6-methyl-1,6-undecadiene and 7-methyl-1,6-octadiene; 2,3-diisopropylidene-5 -Norbornene, 2-ethylidene-
And trienes such as 3-isopropylidene-5-norbornene. Of these non-conjugated polyenes, 5-
Ethylidene-2-norbornene, dicyclopentadiene, 1,4-hexadiene and the like are preferred, and 5-ethylidene-2-norbornene is more preferred.

As the ethylene copolymer rubber (A),
Ethylene / propylene / non-conjugated diene copolymer rubber, ethylene / 1-butene / non-conjugated diene copolymer rubber is preferred, and ethylene / propylene / non-conjugated diene copolymer rubber, especially ethylene / propylene / 5-ethylidene-2
-Norbornene copolymer rubber is particularly preferred in that a thermoplastic elastomer having an appropriate crosslinked structure can be obtained.
Mooney viscosity of the ethylene copolymer rubber (A) [ML
_{1 + 4} (100 ° C.)] is usually 50 to 300, preferably 100 to 160.

The iodine value of the ethylene copolymer rubber (A) is usually from 3 to 30, preferably from 5 to 25.
When the iodine value of the ethylene-based copolymer rubber (A) is in such a range, crosslinking is performed in a well-balanced manner, and a thermoplastic elastomer composition having excellent moldability and rubber elasticity can be obtained. The blending amount of the ethylene copolymer rubber (A) is based on 100 parts by weight of the total amount of the ethylene copolymer rubber (A), the olefin resin (B), and other components used as necessary. , 40 to 85 parts by weight, preferably 60 to 8 parts by weight
0 parts by weight.

In the present invention, in addition to the ethylene copolymer rubber (A), a rubber other than the ethylene copolymer rubber (A), for example, styrene, may be used as the rubber component within a range not to impair the object of the present invention.・ Butadiene rubber or hydrogenated product thereof,
Styrene / isoprene rubber or a hydrogenated product thereof, nitrile rubber, 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.

[Olefin resin (B)] The olefin resin (B) used in the present invention is generally a high molecular weight solid obtained by polymerizing one or more monoolefins by a high-pressure method or a low-pressure method. Consists of a product. Such resins include, for example, isotactic and syndiotactic monoolefin polymer resins. These representative resins are commercially available.

The suitable starting olefin for the olefin resin (B) is preferably an α-olefin having 2 to 20 carbon atoms.
Olefins, specifically ethylene, propylene, 1-
Butene, 1-pentene, 1-hexene, 1-octene,
1-decene, 2-methyl-1-propene, 3-methyl-
Examples thereof include 1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene and the like. These olefins are used alone or in combination of two or more. The polymerization mode may be random or block as long as a resinous material is obtained. These olefin resins can be used alone or
Also, two or more kinds may be used in combination.

Among these olefin resins, a propylene polymer, specifically, a propylene homopolymer,
Propylene-ethylene block copolymer, propylene
Particularly preferred are an ethylene random copolymer, a propylene / ethylene / butene random copolymer, and an ethylene / 4-methyl-1-pentene random copolymer. The olefin resin (B) used in the present invention is an MFR (ASTM)
D1238-65T, 230 ° C, 2.16 kg) is usually 0.01 to 100 g / 10 min, particularly 0.05 to 50 g.
It is preferably in the range of g / 10 minutes. The olefin-based resin (B) has a role of improving the fluidity and heat resistance of the composition.

In the present invention, the olefin resin (B)
Is from 15 to 60 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the total amount of the ethylene-based copolymer rubber (A) and the olefin-based resin (B), and other components used as necessary. 20 to 50 parts by weight. When the olefin resin (B) is used at the above ratio, flexibility,
A thermoplastic elastomer composition having excellent rubber elasticity and excellent moldability can be obtained.

[Softener (C)] In the present invention, a softener (C) can be used if necessary. The softening agent may be oil-extended to the ethylene copolymer rubber (A) 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, petroleum asphalt, petrolatum; coal tar softening agents such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil Fatty oils such as soybean oil and coconut oil; tall oil; waxes such as beeswax, carnauba wax and lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, zinc laurate and metals thereof. Salt; terpene resin, petroleum resin, coumarone indene resin,
Synthetic polymer substances such as atactic polypropylene; ester softeners such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate; microcrystalline wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, and liquid thiocol. Among these softeners, a paraffin-based process oil is preferable, and a high-viscosity type paraffin-based process oil having a low content of easily volatile low-molecular-weight components is particularly preferable. Here, the high-viscosity type refers to one having a kinematic viscosity at 40 ° C. in the range of 200 to 1000 centistokes.

In the present invention, the blending amount of the softener is determined from the viewpoint of heat resistance of the obtained thermoplastic elastomer composition, based on the ethylene copolymer rubber (A) and the olefin resin (B), and if necessary. It is necessary that the amount is 45 parts by weight or less, preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, based on 100 parts by weight of the total amount of other components used. When added later without oil extension, the blending amount of the softening agent is 100 parts by weight in total with the ethylene copolymer rubber (A) and the olefin resin (B) together with the oil extension. To 100 parts by weight, preferably 3 to 80 parts by weight, more preferably 5 parts by weight.
５０50 parts by weight. When the softening agent is used in the above ratio, the obtained thermoplastic elastomer composition has excellent fluidity at the time of molding and does not lower the mechanical properties of the molded article.

[Other Components] In addition to the ethylene copolymer rubber (A), the olefin resin (B) and the softener (C), the thermoplastic elastomer composition of the present invention contains an inorganic filler and the like. Can be blended. As the inorganic filler, specifically, calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth,
Mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass sphere, shirasu balloon, basic magnesium sulfate whisker, calcium titanate whisker, aluminum borate Whiskers and the like.

In the present invention, from the viewpoint of rubber elasticity and moldability of the obtained thermoplastic elastomer composition, the inorganic filler is required to contain ethylene copolymer rubber (A) and olefin resin (B), It is usually used in a proportion of 100 parts by weight or less, preferably 2 to 30 parts by weight, based on 100 parts by weight of the total amount of other components used in accordance with the above. Further, in the present invention, a conventionally known heat-resistant stabilizer, an anti-aging agent, a weather-resistant stabilizer, an antistatic agent; a lubricant such as a metal soap and a wax in the thermoplastic elastomer composition impairs the object of the present invention. It can be added in a range that does not exist.

The thermoplastic elastomer composition of the present invention comprises:
After mixing the above-mentioned ethylene copolymer rubber (A) and olefin resin (B) with a softening agent and / or an inorganic filler compounded as necessary, the mixture is dynamically mixed in the presence of a crosslinking agent. To a heat treatment. Here, "dynamically heat-treating" means kneading in a molten state. Examples of the crosslinking agent used in the present invention include organic peroxides, phenol resins, sulfur, hydrosilicone compounds, amino resins, quinones or derivatives thereof, amine compounds, azo compounds, epoxy compounds, and isocyanates. Crosslinking agents commonly used in mold rubbers may be mentioned. Among these crosslinking agents, organic peroxides are particularly preferred.

As the organic peroxide used in the present invention, 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-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide and the like.

Among them, 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 and the like.
Bifunctional organic peroxides having O-) are preferred, with 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane being most preferred.

Such organic peroxides can be used in view of heat resistance, tensile properties, rubber elasticity, and moldability of the thermoplastic elastomer composition to be obtained from ethylene copolymer rubber (A) and olefin resin (B). ), And other components used as needed are used in an amount of usually 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight of the total amount.

In the crosslinking treatment with the organic peroxide,
Sulfur, p-quinonedioxime, p, p'-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N, N'-m-phenylene Crosslinking aids such as maleimide, divinylbenzene, triallyl cyanurate, or polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate; vinyl butyrate And polyfunctional vinyl monomers such as vinyl stearate.

By using the compound as described above,
A uniform and mild crosslinking reaction can be expected. Particularly, in the present invention, divinylbenzene is most preferred. Divinylbenzene is easy to handle, has good compatibility with the ethylene-based copolymer rubber (A) and the olefin-based resin (B), which are the main components of the object to be crosslinked, and has an organic peroxide. Since it has a solubilizing effect and acts as a dispersant for an organic peroxide, a thermoplastic elastomer composition having a uniform cross-linking effect by heat treatment and a good balance between fluidity and physical properties can be obtained.

Compounds such as the above-mentioned cross-linking aids and polyfunctional vinyl monomers can be used as the ethylene copolymer rubber (A).
And the olefin-based resin (B), and other components used as necessary, are used in an amount of usually 5 parts by weight or less, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the total amount. Can be In addition, in order to promote the decomposition of organic peroxide, triethylamine, tributylamine, 2,
Decomposition accelerators such as tertiary amines such as 4,6-tri (dimethylamino) phenol and naphthenates such as aluminum, cobalt, vanadium, copper, calcium, zirconium, manganese, magnesium, lead and mercury can be used. Good.

The dynamic heat treatment in the present invention is preferably performed in a non-open type apparatus, and is preferably performed in an atmosphere of an inert gas such as nitrogen or carbon dioxide. The temperature of the heat treatment is 300 ° C. from the melting point of the olefin resin (B).
And usually 150 to 270 ° C., preferably 17
0-250 ° C. The kneading time is usually 1 to 20 minutes,
Preferably, it is 1 to 10 minutes. Further, the shear force applied is, 10～50,000Sec ^-1 shear rate, preferably in the range of 100~20,000sec ^-1.

As a kneading device, a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader), a single-screw or twin-screw extruder can be used, but a non-open type device is preferable, and a twin-screw extruder is particularly preferable. . In the production of the olefin-based thermoplastic elastomer composition of the present invention, it is preferable to perform a static heat treatment in hot air after the dynamic heat treatment as described above. Here, "statically heat-treating" means keeping the material at a temperature equal to or lower than the melting point for a certain period of time in a state of standing or stirring.

At this time, the static heat treatment is performed under the following conditions: Q ≧ 0.1 and t ≧ 2- ^{(T-110) / 10} (where Q is the amount of hot air supplied per unit weight of the workpiece supplied during drying ⁾ . Amount (m ³ / (time · kg)), t represents the heat treatment time (hour), and T represents the temperature (° C.) of the hot air immediately before it hits the object to be treated. It is possible to obtain an olefin-based thermoplastic elastomer composition which has been removed and has better fogging properties. Further, when the above-mentioned bifunctional organic peroxide is used as a cross-linking agent, the residual amount of the diol which is a decomposition product thereof is reduced to 30 pp by the dynamic heat treatment and / or the static heat treatment.
m or less is preferable in terms of fogging properties.

As described above, DIN (German Industrial Standard; Deutsche Industrie Nor
m) When the fogging test was conducted at 100 ° C. for 3 hours based on Method A of 75201, the gloss value of the glass plate was 80%.
Or more, preferably 85% or more, and a haze value of 1
A thermoplastic elastomer composition having good fogging properties of 0% or less, preferably 7% or less is obtained.

[Automobile Interior Parts] The molded article of the present invention is obtained by molding the thermoplastic elastomer composition of the present invention, and is most suitable for use as an automobile interior part. The automobile interior part of the present invention is usually manufactured according to the following ordinary method. (1) It is supplied to a plastic processing machine such as an extrusion molding machine with a T-die, a calendar molding machine or the like, and molded into a desired shape such as a sheet. (2) Form into a desired shape by injection molding.

The automobile interior part thus obtained is made of the olefin-based thermoplastic elastomer composition 10 described above.
The olefin resin may be contained in an amount of 20 to 200 parts by weight with respect to 0 parts by weight. The olefin-based resin used here includes the olefin-based resin used in the production of the olefin-based thermoplastic elastomer composition. In particular, low-density polyethylene, linear low-density polyethylene, polypropylene, propylene / ethylene block copolymer, polybutene-1, crystalline ethylene / α-
Olefin copolymer (for example, ethylene 4-methyl-1
-Pentene random copolymer) and the like.

The surface layer of the automobile interior part of the present invention may be provided with a surface layer made of at least one compound selected from polyurethane, saturated polyester, acrylate resin, polyvinyl chloride and isocyanate resin. As the saturated polyester used for forming such a surface layer, polyethylene terephthalate, polybutylene terephthalate and derivatives thereof are used. Further, as the acrylate resin, polymethyl (meth) acrylate, polyisobutyl (meth) acrylate, poly-2-ethylhexyl (meth) acrylate, or the like is used. Further, as the isocyanate resin, polyhexamethylene diisocyanate, polyisophorone diisocyanate and the like are used.

The thickness of such a surface layer is preferably 300 μm or less. A primer layer can be interposed between the skin layer and such a surface layer. Further, the automobile interior parts of the present invention are a laminate with a polyolefin foam,
Alternatively, a laminate with a polyolefin resin can be formed. Examples of the polyolefin used here include olefin resins used in the production of the olefin thermoplastic elastomer composition. Particularly, polyethylene, polypropylene and the like are preferable.

For example, such a laminate is formed by extruding an olefin-based thermoplastic elastomer composition with an extruder equipped with a T-die, and extruding the molten sheet-like thermoplastic elastomer composition into a polyolefin foam sheet. It is manufactured by passing between a pair of rolls in a laminated state, or by sequential injection molding of a polyolefin resin and an olefin-based thermoplastic elastomer. The automotive interior parts of the present invention are mainly used as skin layers of door trims, instrument panels, ceilings, handles, console boxes, seats and the like.

[0039]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the raw materials used in producing the olefin-based thermoplastic elastomer compositions of Examples and Comparative Examples are as follows. (A-1) Oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber: Molar ratio of units derived from ethylene to units derived from propylene (ethylene / propylene) 81 / 19,5 100 parts by weight of a polymer having an iodine value of 13 based on ethylidene-2-norbornene and a Mooney viscosity of ML _{1 + 4} (100 ° C.) 140 were mixed with 100 parts by weight of a paraffinic process oil (C-1, PW-380 manufactured by Idemitsu Kosan Co., Ltd .; 40). (A-2) Oil-extended ethylene / propylene / dicyclopentadiene copolymer rubber: Molar ratio of units derived from ethylene to units derived from propylene. (ethylene/
Propylene) 77/23, iodine value based on dicyclopentadiene 8, Mooney viscosity ML _{1 + 4} (100 ° C.) 14
(B-1) Propylene homopolymer: 40 parts by weight of paraffinic process oil (C-1, PW-380 manufactured by Idemitsu Kosan Co., Ltd .; kinematic viscosity at 40 ° C. 382 centistokes) in 100 parts by weight of polymer No. 0 MFR (ASTM
D1238-65T, 230 ° C, 2.16 kg) 5
(G / 10 minutes) (B-2) Propylene / ethylene block copolymer; M
FR (ASTM D1238-65T, 230 ° C,
2.16 kg) 10 (g / 10 min), ethylene content 8 mol% (B-3) ethylene / 4-methyl-1-pentene random copolymer; MFR (190 ° C., 2.16 kg) 20,
97 mol% ethylene content

Example 1 75 parts by weight of oil-extended ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (A-1) pellets (rubber polymer 5
3.6 parts by weight, paraffinic process oil 21.4 parts by weight) Pellets 25 of propylene homopolymer (B-1)
Parts by weight, 0.3 parts by weight of an organic peroxide [2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane] and 0.5 parts by weight of divinylbenzene (DVB) are sufficiently mixed in a Henschel mixer. After mixing, the mixture was fed to a twin-screw extruder and subjected to dynamic heat treatment under the following conditions to obtain thermoplastic elastomer pellets. Dynamic heat treatment conditions Extruder: ZSK-53 manufactured by Werner & Freidel, screw diameter 53 mm Temperature setting: C1 / C2 / C3 / C4 / C5 / D = 140
/ 160/180/220/220/200 (° C.) Maximum shear rate: 2800 (sec ⁻¹ ) Extrusion amount: 50 (kg / hour) Then, 10.0 kg of the obtained pellets are caged with a 100-mesh stainless steel wire mesh basket. And the basket was put into a hot-air drier and subjected to static heat treatment under the following conditions.

Hot air volume Q: 0.8 (m ³ / (hour · kg)) Heat treatment time t: 2 (hours), temperature of hot air immediately before hitting the pellets T: 115 (° C.) Next, pellets subjected to static heat treatment DI using 10g
A fogging test was performed at 100 ° C. for 3 hours based on the method A of N 75201, and the gloss value and haze value of the tested glass plate were measured. In addition, the diol component (2,5-dimethyl-
2,5-dihydroxyhexane) was measured. Table 1 shows the results. <Method of measuring diol component> After Soxhlet extraction of 25 g of pellets with 150 ml of methyl ethyl ketone for 5 hours, nitrogen was bubbled and concentrated to 10 ml or less. Further, the concentration of the solution diluted to 25 ml with chloroform was measured by gas chromatography. For the determination of the concentration, a calibration curve prepared with a standard sample of a known concentration was used.
Also, from the obtained thermoplastic elastomer pellets,
An instrument panel with a grain pattern was formed by two-color injection molding with a propylene homopolymer as a base material. There was no particular problem in moldability and the like, and the product appearance was good.

Example 2 60 parts by weight of oil-extended ethylene / propylene / dicyclopentadiene copolymer rubber (A-2) pellets (42.9 parts by weight of rubber polymer,
Paraffin-based process oil (17.1 parts by weight), propylene / ethylene block copolymer (B-2) pellets 25 parts by weight, ethylene / 4-methyl-1-pentene random copolymer (B-3) pellets 15 Parts by weight of an organic peroxide [2,5-dimethyl-2,5-di- (tert-
[Butylperoxy) hexane] and a thermoplastic elastomer pellet were obtained in the same manner as in Example 1 from 0.2 parts by weight and divinylbenzene (DVB) 0.3 part by weight. Next, 10.0 kg of the obtained pellets were placed in a 100-mesh stainless steel mesh basket, and the basket was placed in a hot-air drier and subjected to static heat treatment under the following conditions.

Hot air volume Q: 0.5 (m ³ / (time · k)
g)) Heat treatment time t: 3 (hours), temperature of hot air immediately before hitting the pellets T: 110 (° C.) Next, a fogging test was performed in the same manner as in Example 1 by using 10 g of the pellets subjected to static heat treatment, and tested. The gloss value and haze value of the glass plate were measured. Further, the diol component (2,5-
(Dimethyl-2,5-dihydroxyhexane) was measured. Table 1 shows the results.

Further, 80 parts by weight of pellets of the obtained thermoplastic elastomer were mixed with a propylene / ethylene block copolymer (MFR (ASTM D1238-65T, 23
0 ° C., 2.16 kg) 5 parts by weight of 0.5 (g / 10 min), ethylene content 8 mol%) pellets and ethylene
Methyl-1-pentene random copolymer (MFR (19
After mixing with a Henschel mixer, 15 parts by weight of pellets of 0 ° C., 2.16 kg) 2 and ethylene content of 97 mol%) were extruded with an extruder equipped with a T-die, embossed with embossing rolls, and having a thickness of 0.7 mm. Was prepared. Further, the sheet is heat-laminated with a polypropylene foam (Toray, PEF; PPKM15030), and the composite sheet is vacuum-formed at 140 ° C. using a male-drawn instrumental mold and then fixed to a polypropylene base material. Then, an instrumental was prepared. There was no particular problem in moldability and the like, and the product appearance was good.

(Comparative Example 1) 10.0 kg of thermoplastic elastomer pellets prepared in the same manner as in Example 1 from the same raw materials as in Example 1 were placed in a 100-mesh stainless steel wire mesh basket, and the basket was placed in a hot-air dryer. Then, static heat treatment was performed under the following conditions.

Hot air volume Q: 0.05 (m ³ / (hour · kg)) Heat treatment time t: 2 (hours) Temperature of hot air immediately before hitting the pellets T: 115 (° C.) Next, pellets subjected to static heat treatment A fogging test was performed in the same manner as in Example 1 using 10 g, and the gloss value and haze value of the tested glass plate were measured. Further, the diol component (2,5-
(Dimethyl-2,5-dihydroxyhexane) was measured. Table 1 shows the results.

Comparative Example 2 10.0 kg of thermoplastic elastomer pellets prepared from the same raw materials as in Example 1 in the same manner as in Example 1 were placed in a 100-mesh stainless steel wire mesh basket, and the basket was placed in a hot-air dryer. Then, static heat treatment was performed under the following conditions.

Hot air volume Q: 0.8 (m ³ / (hour · k)
g)) Heat treatment time t: 0.5 (hour), temperature of hot air immediately before hitting the pellets T: 115 (° C) Next, a fogging test was performed in the same manner as in Example 1 using 10 g of the pellets subjected to static heat treatment. The gloss value and haze value of the tested glass plate were measured. Further, the diol component (2,5-
(Dimethyl-2,5-dihydroxyhexane) was measured. Table 1 shows the results.

Comparative Example 3 10.0 kg of thermoplastic elastomer pellets prepared in the same manner as in Example 1 from the same raw materials as in Example 1 were placed in a 100-mesh stainless steel wire mesh basket, and the basket was placed in a hot-air dryer. Then, static heat treatment was performed under the following conditions.

Hot air volume Q: 0.8 (m ³ / (hour · kg)) Heat treatment time t: 2 (hours) Temperature of hot air immediately before hitting the pellets T: 90 (° C.) Next, pellets subjected to static heat treatment A fogging test was performed in the same manner as in Example 1 using 10 g, and the gloss value and haze value of the tested glass plate were measured. Further, the diol component (2,5-
(Dimethyl-2,5-dihydroxyhexane) was measured. Table 1 shows the results.

Comparative Example 4 10.0 kg of thermoplastic elastomer pellets prepared in the same manner as in Example 1 from the same raw materials as in Example 2 were placed in a 100-mesh stainless steel wire-mesh basket, and the basket and the hot-air dryer were used. And subjected to a static heat treatment under the following conditions.

Hot air volume Q: 0.5 (m ³ / (hour · k)
g)) Heat treatment time t: 3 (hours), temperature of hot air immediately before hitting the pellets T: 90 (° C.) Then, a fogging test was performed in the same manner as in Example 1 by using 10 g of the pellets subjected to static heat treatment, and tested. The gloss value and haze value of the glass plate were measured. Further, the diol component (2,5-
(Dimethyl-2,5-dihydroxyhexane) was measured. Table 1 shows the results.

[0053]

[Table 1]

[0054]

According to the present invention, it is possible to provide an olefin-based thermoplastic elastomer composition having excellent fogging properties, and to provide an automobile interior part having good fogging properties by molding it. Can be.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/00 CES C08J 5/00 CES C08K 5/14 C08K 5/14 C08L 23/02 C08L 23/02 / / B29K 21:00 B29K 21:00 23:00 23:00 (72) Inventor Akira Uchiyama 3 Chigusa Kaigan, Ichihara-shi, Chiba Mitsui Chemicals Co., Ltd. F-term (reference) 3D023 BA01 BB08 BC00 BD03 BE04 BE31 4F070 AA13 AA16 AC24 AE02 AE08 BA02 GA05 GA06 GB02 GC02 4F071 AA14 AA15X AA20 AA20X AA21 AA21X AA76 AC08 AF53 BB05 BB06 BC01 4F201 AA03 AA09E AA45 AB05 AB07 AC01 AH26 AR06 AR11 BA02 BA04 BC01 BC02 BC03 BC03 BC03 BC03 BC03 AE033 AE053 AG003 BB03X BB05W BB12X BB15X BB17X EK006 EK036 EK046 EK086 FD010 FD023 FD146 GN00

Claims (6)

[Claims] 1. An ethylene copolymer rubber (A) 40 to 8
Contains 5 parts by weight, 60 to 15 parts by weight of the olefin resin (B) and 45 parts by weight or less of the softener (C) [the total amount of the components (A), (B) and (C) is 100 parts by weight]. The mixture is dynamically heat treated in the presence of a crosslinker to give 10 g
The gross value of the glass plate is 80% or more when the fogging test is performed at 100 ° C. for 3 hours based on the method A of DIN 75201 using the pellets, and the haze value is 1
An olefin-based thermoplastic elastomer composition having 0% or less. 2. After the dynamic heat treatment, the following conditions are satisfied: Q ≧ 0.1 and t ≧ 2- ^{(T-110) / 10} (where Q is hot air supplied per unit weight of the material to be processed supplied during drying ^). (M ³ / (time · kg)), t is a heat treatment time (hour), and T is a temperature (° C.) of hot air just before the object is treated. Item 10. The thermoplastic elastomer composition according to Item 1. 3. The crosslinking agent is a bifunctional organic peroxide having two peroxide bonds in one molecule, and the concentration of the diol which is a decomposition product remaining in the pellet is 30 ppm or less. The thermoplastic elastomer composition according to claim 1. 4. A molded article obtained by molding the thermoplastic elastomer composition according to claim 1. 5. The molded article according to claim 4, which is an automobile interior part. 6. An ethylene copolymer rubber (A) 40-8.
Contains 5 parts by weight, 60 to 15 parts by weight of the olefin resin (B) and 45 parts by weight or less of the softener (C) [the total amount of the components (A), (B) and (C) is 100 parts by weight]. After dynamically heat-treating the mixture in the presence of a cross-linking agent, the following conditions are satisfied: Q ≧ 0.1 and t ≧ 2- ^{(T-110) / 10} (where Q is the workpiece supplied during drying) Static heat treatment is performed at the amount of hot air per unit weight (m ³ / (time · kg)), t is the heat treatment time (hour), and T is the temperature (° C.) of the hot air immediately before hitting the object. A method for producing an olefin-based thermoplastic elastomer composition, comprising: