JPH1034681A - Thermoplastic elastomer composition, powder and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition capable of providing a molded article of a thermoplastic elastomer which is not easily whitened even when bent. SOLUTION: (A) 100 parts by weight of a polyolefin resin, and (B) an ethylene / α-olefin copolymer rubber 5-2 having an α-olefin unit content of 50% by weight or more.
50 parts by weight and (C) α-olefin unit content is 5
A thermoplastic elastomer composition containing 0 to 500 parts by weight of an ethylene / α-olefin copolymer rubber in an amount of less than 0% by weight.

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, a powder thereof, and a molded product.

[0002]

2. Description of the Related Art Conventionally, a molded article having a complex uneven pattern such as a leather grain or a stitch pattern on its surface has been used as a skin material for automobile interior parts and the like. Conventionally, as such a molded article, a molded article made of a vinyl chloride resin has been known, but recently, a molded article made of a thermoplastic elastomer has been proposed as an alternative to such a molded article (for example, see Japanese Patent Application Laid-Open No. Hei 5- 1183, JP-A-5-5050). However, a molded article made of such a thermoplastic elastomer has poor flexibility as compared to a molded article made of a vinyl chloride resin, and tends to whiten when bent. For this reason, when the molded body is taken out of the mold during the production of the molded body, or when the molded body is preliminarily shaped before being bonded to the base material, the bent portion tends to be whitened.

[0003]

The inventors of the present invention have conducted intensive studies to develop a composition capable of providing a molded article of a thermoplastic elastomer which is not easily whitened even when bent. The present inventors have found that a thermoplastic elastomer composition containing a specific ethylene / α-olefin-based copolymer rubber at a specific ratio can give a molded product that does not easily whiten, and have led to the present invention.

[0004]

That is, the present invention provides:
(A) 100 parts by weight of polyolefin resin, (B) α-
5-250 parts by weight of an ethylene / α-olefin copolymer rubber having an olefin unit content of 50% by weight or more and (C) an ethylene / α-olefin type copolymer having an α-olefin unit content of less than 50% by weight. Polymer rubber 0-50
It is intended to provide a thermoplastic elastomer composition containing 0 parts by weight.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyolefin resin (A) in the thermoplastic elastomer composition of the present invention is a polymer or copolymer of one or more olefins having crystallinity. Examples of the olefin include olefins having 2 to 8 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, and 1-octene. Examples of such polyolefin-based resins include polyethylene, polypropylene, polybutene-1, and copolymers of propylene with other α-olefins (eg, 1-butene).

[0006] When the polyolefin resin (A) is a propylene / ethylene copolymer or a propylene / 1-butene copolymer, the thermoplastic elastomer composition of the present invention provides a molded article having particularly excellent flexibility. Can be given. In addition, ethylene and the number of carbon atoms are 3
A copolymer obtained by copolymerizing two or more types of monomers selected from α-olefins of No. 8 to No. 8 can also be used.
For example, in the first stage, propylene is homopolymerized, and in the second stage, propylene and α other than ethylene or propylene
-A copolymer obtained by copolymerizing with an olefin can be used.

In the case where a molded article is produced by a powder molding method using the powder of the thermoplastic elastomer composition of the present invention, (A) the melt flow of the polyolefin-based resin from the viewpoint of the strength of the obtained molded article. Rate (JIS K
A value measured at 230 ° C. and a load of 2.16 kgf according to −7210. Hereinafter, it is referred to as MFR. ) Is 20-500g
/ 10 min, more preferably within the range of 50 to 300 g / 10 min.

(B) The ethylene / α-olefin copolymer rubber having an α-olefin unit content of 50% by weight or more refers to at least one selected from amorphous ethylene / α-olefin copolymers. One kind.

Examples of the α-olefin include α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene and 1-octene, and α-olefins having 4 to 8 carbon atoms. Olefins are preferred, and α-olefins having 4 to 6 carbon atoms are particularly preferred.

(B) The ethylene / α-olefin-based copolymer rubber includes, as monomer units, for example, dicyclopentadiene, 2-methyl-2,5-norbornadiene, 5-
5 to 12 carbon atoms such as ethylidene-2-norbornene, 1,4-hexadiene and 1,6-octadiene
Non-conjugated diene, styrene, α-methylstyrene,
A vinyl aromatic compound having 8 to 12 carbon atoms such as 2,4-dimethylstyrene and p-methylstyrene may be copolymerized.

(B) The ethylene / α-olefin copolymer rubber has an α-olefin unit content of at least 50% by weight, preferably 50 to 90% by weight, more preferably 60 to 90% by weight. It is. The content of the α-olefin unit is determined by the peak derived from the α-olefin unit determined by infrared absorption spectroscopy (for example, the peak of the symmetric bending vibration of the terminal methyl group of the short-chain branch, or the side of the methylene group in the branch). It can be determined from the absorbance at the peak of the fluctuation vibration. The method for measuring the α-olefin unit content is described, for example, in Reference (1), “Polymer Analysis Handbook, published by Kinokuniya Bookstore, edited by The Japan Society for Analytical Chemistry, Chapter 2, Section 2.2 (pp. 587-591). ), 1995 ”, Reference (2),“ Region of Chemistry, Special Issue No. 140, Infrared, Raman, Vibration [II] Present and Future Prospects, Published by Nankodo, Edited by Naotomichi Tsuboi et al., Characterization of Polyethylene by Infrared Absorption (No. 73-81), 1983 ".

The ethylene / α-olefin copolymer rubber (B) is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 3-163088 and 5-196441, and ethylene and α-olefin, and If necessary, another monomer can be produced by a method of polymerizing using a metal complex as an initiator in the presence of a cocatalyst. Examples of the cocatalyst include aluminum compounds such as methylaluminoxane, aluminum halide, aluminum alkyl halide, and trialkylaluminum, and boron such as tris (pentafluorophenyl) borane and triphenylcarbeniumtetrakis (pentafluorophenyl) borane. Contained Lewis acids. One compound can be used as a cocatalyst, or two or more compounds can be used in combination. Examples of metal complexes, (tert-butylamido) dimethyl - zirconium complexes such as (eta ⁵ cyclopentadienyl) silane zirconium dichloride, (tert-butylamido) dimethyl (tetramethyl-eta ⁵ - cyclopentadienyl) silane titanium Dichloride, (anilide) (dimethyl)
Titanium complexes such as (tetramethyl-η ⁵ -cyclopentadienyl) silanetitanium dichloride are included. These complexes can be used by being supported on a carrier such as alumina, magnesium chloride, and silica. Ethylene and α
The polymerization with the olefin is usually carried out in a solvent. As the solvent, for example, a hydrocarbon solvent such as hexane, heptane, toluene, ethylbenzene, xylene and the like is used. The polymerization can be carried out at atmospheric pressure or under reduced pressure in an atmosphere of an inert gas such as nitrogen, argon, hydrogen and the like. The polymerization temperature is usually in the range of -30 to 250C.

The content of the ethylene / α-olefin copolymer rubber (B) in the thermoplastic elastomer composition of the present invention is 5 to 250 parts by weight per 100 parts by weight of the polyolefin resin (A). Preferably it is in the range of 20 to 250 parts by weight, more preferably 50 to 250 parts by weight, still more preferably 80 to 220 parts by weight. When the content of the (B) ethylene / α-olefin-based copolymer rubber is less than 5 parts by weight, the obtained molded article has poor flexibility and tends to whiten when bent. Also,
When the amount exceeds 250 parts by weight, the tendency of the surface of the obtained molded article to have high tackiness becomes remarkable.

[0014] The thermoplastic elastomer composition of the present invention comprises:
5 per 100 parts by weight of the polyolefin resin (A)
(C) α-olefin unit content of not more than 00 parts by weight
It may contain less than 0% by weight of an ethylene / α-olefin copolymer rubber. When the thermoplastic elastomer composition contains the (C) ethylene / α-olefin copolymer rubber, the cold resistance (low temperature impact resistance) of a molded article obtained by using the same is improved.

The (C) ethylene / α-olefin copolymer rubber includes a non-crystalline ethylene / α-olefin copolymer and a non-crystalline ethylene / α-olefin /
Non-conjugated diene copolymers are exemplified. Preferred α-
Examples of the olefin include propylene, 1-butene,
Examples thereof include α-olefins having 3 to 10 carbon atoms, such as 3-methyl-pentene-1, 1-octene and 1-decene, and propylene and 1-butene are particularly preferable. Preferred non-conjugated dienes include dicyclopentadiene, 2-methyl-2,5-norbornadiene, ethylidene norbornene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, 1,6-octadiene and the like, and in particular, ethylidene norbornene Is preferred. Examples of the (C) ethylene / α-olefin copolymer rubber include ethylene / propylene copolymer rubber and ethylene / 1
-Including butene copolymer rubber, ethylene-propylene-ethylidene norbornene copolymer rubber (EPDM). E
The thermoplastic elastomer composition of the present invention containing PDM can give a molded article having particularly excellent heat resistance and tensile properties.

(C) The α-olefin unit content in the ethylene / α-olefin copolymer rubber is less than 50% by weight, preferably 5 to 40% by weight, more preferably 1 to 40% by weight.
0 to 35% by weight, and the ethylene unit content is:
Usually 60 to 95% by weight, preferably 65 to 90% by weight
It is. The α-olefin unit content and ethylene unit content can be determined by ¹³ C-NMR method, infrared absorption spectroscopy, and the like.

When a molded article is produced by a powder molding method using the powder of the thermoplastic elastomer composition of the present invention, the (C) ethylene / α-olefin is preferably used in view of the strength of the obtained molded article. Mooney viscosity of copolymer rubber [10 according to ASTM D-927-57T]
Value measured at 0 ° C. Hereinafter, it is referred to as ML _{1 + 4} (100 ° C.). ] Is preferably in the range of 10 to 350, more preferably 15 to 300.

The content of the ethylene / α-olefin copolymer rubber (C) in the thermoplastic elastomer composition of the present invention is 0 to 500 parts by weight per 100 parts by weight of the polyolefin resin (A). From the viewpoint of cold resistance (low-temperature impact resistance) of the obtained molded body, it is preferably 5 to 400.
Parts by weight, more preferably in the range of 10 to 250 parts by weight.

In the thermoplastic elastomer composition of the present invention, (A) a polyolefin resin, (B) an ethylene / α-olefin copolymer rubber, and (C) an ethylene / α-olefin copolymer rubber, It may be cross-linked within and / or between molecules. That is, (A) the polyolefin-based resin may be cross-linked within and / or between molecules, and (B) the ethylene / α-olefin-based copolymer rubber may be cross-linked within and / or between molecules. Or (C) the ethylene / α-olefin-based copolymer rubber may be cross-linked intramolecularly and / or intermolecularly, or (A) polyolefin-based resin and (B) ethylene / α- -An olefin copolymer, or (A) a polyolefin resin and (C) an ethylene / α-olefin copolymer, or (B) an ethylene / α-olefin copolymer and (C) ethylene / α-olefin The copolymer may be crosslinked between molecules.

For example, the cross-linking of (A) the polyolefin resin and / or (C) the ethylene / α-olefin copolymer rubber is carried out by (A) the polyolefin resin and (C) the ethylene / α-olefin copolymer. It can be carried out by kneading the rubber and kneading the resulting kneaded mixture to further dynamically crosslink. Dynamic crosslinking can be performed, for example, by kneading the kneading mixture and a crosslinking agent under heating.

The crosslinking agent is usually 2,5-dimethyl-
Organic peroxides such as 2,5-di (tert-butylperoxyno) hexane and dicumyl peroxide are used,
The amount used is per 100 parts by weight of the total amount of (A) polyolefin resin, (B) ethylene / α-olefin copolymer rubber and (C) ethylene / α-olefin copolymer rubber to be crosslinked. Usually 1 part by weight or less, preferably 0.1 to 0.8 parts by weight, more preferably 0.2 to 0.8 parts by weight.
The range is 0.6 parts by weight.

When an organic peroxide is used as a crosslinking agent, a thermoplastic elastomer composition which gives a molded article having excellent heat resistance when subjected to dynamic crosslinking in the presence of a crosslinking aid such as a bismaleimide compound is used. Obtainable. In this case, the amount of the organic peroxide used is such that (A) a polyolefin resin to be crosslinked and (B) ethylene.
α-olefin copolymer rubber and (C) ethylene.
Usually 0.8 parts by weight or less, preferably 0.2 to 0.8 parts by weight per 100 parts by weight of the total amount of the α-olefin copolymer rubber.
Parts by weight, more preferably 0.4 to 0.6 parts by weight. The amount of the crosslinking aid used is 100 in total of (A) the polyolefin resin, (B) the ethylene / α-olefin copolymer rubber, and (C) the ethylene / α-olefin copolymer rubber to be crosslinked. It is usually 1.5 parts by weight or less, preferably 0.2 to 1 part by weight, more preferably 0.4 to 0.8 part by weight per part by weight. The crosslinking aid is preferably blended before the addition of the crosslinking agent, and is usually the component (A) polyolefin-based resin which is subjected to crosslinking,
It is added when kneading (B) the ethylene / α-olefin-based copolymer rubber and (C) the ethylene / α-olefin-based copolymer rubber.

The kneading can be performed by kneading using a single screw extruder or a twin screw extruder while heating the kneaded mixture and the crosslinking agent. By the dynamic crosslinking under the above conditions, the (B) ethylene / α-olefin-based copolymer rubber and (C) the ethylene / α-olefin-based copolymer rubber are usually preferentially intermolecularly and / or intermolecularly. Although cross-linking occurs, (A) the polyolefin resin is cross-linked intramolecularly and / or intermolecularly, or (A) the polyolefin resin and (B) the ethylene / α-olefin copolymer rubber are intermolecular. (A) polyolefin-based resin and (C) ethylene-α-olefin copolymer rubber are cross-linked between molecules, (B) ethylene-α-
The olefin copolymer rubber and (C) the ethylene / α-olefin copolymer rubber may be crosslinked between molecules. The thermoplastic elastomer composition of the present invention can contain any type of crosslinked product.

The thermoplastic elastomer composition of the present invention comprises:
Various additives may be contained. As additives,
For example, mineral oil-based softeners such as paraffin-based process oils, phenol-based, sulfite-based, phenylalkane-based, phosphite-based, amine-based or amide-based heat stabilizers, antiaging agents, weathering stabilizers, antistatic agents, Examples include lubricants such as metal soaps and waxes, internally added mold release agents such as methylpolysiloxane compounds, coloring pigments, fillers, foaming agents, foaming assistants, and cell conditioners. Among them, the mineral oil-based softener improves the melt fluidity of the thermoplastic elastomer composition of the present invention, and the thermoplastic elastomer composition containing the same can give a molded article having excellent flexibility. It is preferred. In the production of the thermoplastic elastomer composition of the present invention, a composition comprising a mineral oil-based softening agent and the above-mentioned (C) ethylene / α-olefin-based copolymer rubber, so-called oil-extended ethylene / α-olefin-based copolymer, is used. Use of a polymer rubber can provide excellent processability in kneading and dynamic crosslinking. The content of the mineral oil-based softener in the oil-extended ethylene / α-olefin copolymer rubber is usually 120 parts by weight or less, preferably 100 parts by weight or less, per 100 parts by weight of the ethylene / α-olefin-based copolymer rubber (C). It is in the range of 30 to 120 parts by weight.

Further, the thermoplastic elastomer composition of the present invention may comprise natural rubber, butyl rubber, chloroprene rubber, acrylonitrile / butadiene rubber, hydrogenated acrylonitrile / butadiene rubber, epichlorohydrin rubber, acrylic Rubber polymers such as rubber, ethylene / acrylic acid copolymer, ethylene / vinyl acetate copolymer and saponified products thereof, ethylene / methyl methacrylate copolymer, ethylene / glycidyl methacrylate / vinyl acetate copolymer It may contain a coalescing component.

The viscoelasticity of the thermoplastic elastomer composition of the present invention can be varied in various ranges depending on the molding conditions of the composition. In the case of a thermoplastic elastomer composition applied to a powder produced by a grinding method, 2
The complex dynamic viscosity η ^* (1) measured at 50 ° C. at an oscillation frequency ω = 1 radian / second is preferably 1.5 × 10 ⁵ poise or less from the viewpoint of moldability of the composition, It is more preferably 5 × 10 ³ poise or less, and further preferably 3 × 10 ³ poise or less. Also, η
^* The lower limit of (1) is usually 1 × 10 ² poise, preferably 3 × 10 ² poise, and more preferably 5 × 10 ² poise.
Poise. Here, the vibration frequency ω at 250 ° C.
The complex dynamic viscosity η ^* (ω) measured at 250 ° C. is the storage viscoelastic modulus G ′ measured at a vibration frequency ω at 250 ° C.
Equation (1) using (ω) and loss viscoelastic modulus G ″ (ω) Is a value calculated based on η ^* (1) is 1.5 ×
If it exceeds 10 ⁵ poise, the melt fluidity of the thermoplastic elastomer composition becomes insufficient, and the processability in the powder molding method tends to decrease.

Further, from the viewpoint of the mechanical strength of the obtained molded body, the above complex dynamic viscosity η ^* (1) and the complex dynamic viscosity η ^* measured at 250 ° C. at an oscillation frequency ω = 100 radians / sec ^. it is preferred that the Newtonian viscosity index n calculated by the equation ^{(2) n = {logη *} (1) -logη * (100)} / 2 (2) is 0.67 or less using the (100) and, More preferably 0.01 to
0.35, particularly preferably 0.03 to 0.25.

Further, in the case of a thermoplastic elastomer composition applied to powder produced by a solvent treatment method, a strand cut method or a die face cut method described later, the complex dynamic viscosity of the thermoplastic elastomer composition η ^* (1) is preferably 5 × 10 ⁴ poise or less, more preferably 1 × 10 ^{2 to} 3 × 10 ³ poise, and particularly preferably 3 × 10 ⁴ poise from the viewpoint of processability of the thermoplastic elastomer composition. It is in the range of 10 ^{2 to} 2 × 10 ³ poise.
Further, the Newton viscosity index n is preferably 0.28 or less, more preferably 0.01 to 0.25, particularly preferably, from the viewpoint of the mechanical strength of the obtained molded body.
It is in the range of 0.03 to 0.20.

The thermoplastic elastomer composition of the present invention comprises:
For example, (A) polyolefin resin, (B) ethylene
It can be produced by kneading the α-olefin-based copolymer rubber and, if necessary, (C) the ethylene / α-olefin-based copolymer rubber. (C) When an ethylene / α-olefin copolymer rubber is used,
It can be produced by kneading (A) a polyolefin resin and (C) an ethylene / α-olefin-based copolymer rubber and then (B) further adding and kneading an ethylene / α-olefin-based copolymer rubber. it can. Further, for example, (A) a polyolefin-based resin and / or (C) an ethylene / α-olefin-based copolymer rubber may have an intramolecular and / or
Alternatively, the thermoplastic elastomer composition of the present invention, which is crosslinked between molecules, is usually obtained by dynamically crosslinking (A) a polyolefin resin and (C) an ethylene / α-olefin copolymer rubber, B) It can be produced by adding and kneading an ethylene / α-olefin copolymer rubber. Here, a single-screw extruder or a twin-screw extruder can be used for kneading the (B) ethylene / α-olefin copolymer rubber. The present invention can also be obtained by dynamically crosslinking a mixture of (A) a polyolefin-based resin, (B) an ethylene / α-olefin-based copolymer rubber, and (C) an ethylene / α-olefin-based copolymer rubber. A thermoplastic elastomer composition can be manufactured. Thus, the thermoplastic elastomer composition of the present invention can be obtained as a melt-kneaded product.

The various additives may be compounded, for example, by mixing (A) a polyolefin resin, (B) an ethylene / α-olefin copolymer rubber, or (C) an ethylene / α- It can be carried out by using an olefin-based copolymer rubber or blending the components (A), (B) and (C) during kneading or dynamic crosslinking.

The thermoplastic elastomer composition of the present invention can be processed into molded articles of various sizes and shapes by various molding methods. For example, the thermoplastic elastomer composition of the present invention is molded from its melt, for example, the above-mentioned melt-kneaded product, into various molded articles by, for example, a press molding method, an injection molding method, an extrusion molding method, or the like.

Further, the thermoplastic elastomer composition of the present invention can be processed into powders of various sizes and shapes, and can be processed into a molded article such as a sheet or a film by a powder molding method using the powder. it can.

[0033] The average sphere-equivalent particle diameter of the powder is preferably 1.2 mm or less, more preferably 0.15 mm or less, from the viewpoint of the easiness of heat fusion between the particles during powder molding.
It is in the range of 1.0 mm. If the heat fusion between the particles is insufficient, pinholes or underfill are likely to occur in the molded body. here,
The average sphere-equivalent particle size of a powder is defined as the diameter of a sphere having the same volume as the average volume of the powder. The average volume (V) of the powder is the total weight (W) of the powder of 100 thermoplastic elastomer compositions taken out at random, the density (D) and the average volume (V) of the thermoplastic elastomer composition. V = W / D (3)

The bulk specific gravity of the powder is preferably 0.38 or more, more preferably 0.38 to 0.3, from the viewpoint of easy adhesion of the powder to the mold surface during powder molding.
0.65, particularly preferably 0.42
It is in the range of 0.65. If the powder does not sufficiently adhere to the mold surface, pinholes or underfill are likely to occur in the molded body. The bulk specific gravity is a value measured according to JIS K-6721.

Such a powder can be produced by various methods as described below. Freezing and pulverization method: The thermoplastic elastomer composition is heated at a temperature not higher than its glass transition temperature (usually -70 ° C or lower, preferably -90 ° C or lower.
℃ below) and pulverize. Solvent treatment method: The powder produced by the above-mentioned freeze-pulverization method, in a solvent having poor compatibility with the thermoplastic elastomer composition, in the presence of a dispersant and an emulsifier, the melting temperature of the thermoplastic elastomer composition or more, Preferably, after stirring at a temperature 30 to 50 ° C. higher than the melting temperature, the mixture is cooled (for example, see JP-A-62-280226). By this method, a spherical powder can be obtained. Strand cutting method: A method in which a molten thermoplastic elastomer composition is extruded from a die into air to form a strand, which is cooled and cut (see, for example,
149747). Die face cut method: A method of cutting while extruding a molten thermoplastic elastomer composition from a die into water.

As a solvent for producing powder by the solvent treatment method, for example, ethylene glycol, polyethylene glycol, polypropylene glycol or the like is used.
It is usually in the range of 300 to 1000 parts by weight, preferably 400 to 800 parts by weight per 0 parts by weight. As the dispersant, for example, ethylene-acrylic acid copolymer, silicic acid anhydride, titanium oxide or the like is used, and the amount of the dispersant is usually 5 to 20 parts by weight, preferably 10 to 15 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition. It is in the range of parts by weight. Examples of the emulsifier include polyoxyethylene sorbitan monolaurate, polyethylene glycol monolaurate,
Sorbitan tristearate or the like is used, and its amount is usually 3 to 15 parts by weight, preferably 5 to 10 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition.

The discharge diameter of the die in the strand cutting method is usually in the range of 0.1 to 3 mm, preferably 0.2 to 2 mm. The discharge rate of the thermoplastic elastomer composition per discharge port of the die is usually 0.1 to 5 kg /.
Hour, preferably in the range of 0.5 to 3 kg / hour. The take-off speed of the strand is usually in the range of 1 to 100 m / min, preferably 5 to 50 m / min. The cooled strand is usually 1.4 mm or less, preferably 0.3 to
It is cut to 1.2 mm. In the die face cutting method, the diameter of the discharge opening of the die is usually 0.1 to 3 mm, preferably 0.2 to 2 mm. The discharge speed of the thermoplastic elastomer composition per discharge port of the die is usually 0.1.
The range is 1 to 5 kg / hour, preferably 0.5 to 3 kg / hour. The temperature of the water is usually 30-70 ° C, preferably 40
~ 60 ° C.

Note that powders produced by the solvent treatment method, the strand cut method, and the die face cut method are sometimes referred to as pellets.

The powder of the thermoplastic elastomer composition can be obtained by a powder slush molding method, a fluid immersion method, an electrostatic coating method,
The present invention can be applied to various powder molding methods such as a powder spraying method and a powder rotational molding method. For example, in order to produce a molded article by the powder slush molding method, first, the thermoplastic elastomer composition powder is heated to a temperature equal to or higher than the melting temperature of the composition, usually 160 to 300 ° C, preferably 210 to 270 ° C. On the molding surface of the mold. The powder is heated on the molding surface for a predetermined period of time, and the powders whose surfaces have at least been fused are fused together. After the lapse of the predetermined time, the unfused powder is recovered. If necessary, the mold on which the molten thermoplastic elastomer composition is placed is further heated. Thereafter, the mold is cooled, and the sheet formed thereon is removed from the mold. In such a method, the mold is heated by, for example, a gas heating furnace method, a heat medium oil circulation method, a dipping method in heat medium oil or hot fluidized sand, a high-frequency induction heating method, or the like. Heating time for heat-sealing the particles of the thermoplastic elastomer composition,
It is appropriately selected according to the size, thickness, and the like of the target molded body. The molded article obtained from the thermoplastic elastomer composition of the present invention has a feature that it is rich in flexibility and hardly whitens even when bent.

The thermoplastic elastomer composition of the present invention containing a foaming agent is excellent in flexibility by various molding methods such as a powder molding method, a press molding method, an extrusion molding method and an injection molding method. A foamed molded article can be manufactured. For example, a foamed molded article can be manufactured by powder-forming a powder of the thermoplastic elastomer of the present invention containing a foaming agent, and further foaming the powder. Also,
A similar foam can be obtained by performing powder molding using a mixed powder comprising a powder of the thermoplastic elastomer composition of the present invention containing no foaming agent and a foaming agent.

As the foaming agent, a pyrolytic foaming agent is usually used. Examples of such a pyrolytic foaming agent include azodicarbonamide, 2,2′-azobisisobutyronitrile,
Azo compounds such as diazodiaminobenzene, sulphonyl hydrazide compounds such as benzenesulfonyl hydrazide, benzene-1,3-sulfonyl hydrazide, p-toluenesulfonyl hydrazide, N, N'-dinitrosopentamethylenetetramine, N, N'-dinitroso- N,
Examples include nitroso compounds such as N'-dimethylterephthalamide, azide compounds such as terephthalazide, and carbonates such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate. Among them, azodicarbonamide is preferably used. The compounding of the blowing agent is usually performed at a temperature equal to or lower than the decomposition temperature of the blowing agent. In addition, the thermoplastic elastomer composition of the present invention may contain a foaming aid and a cell conditioner together with the foaming agent.

The molded article obtained from the thermoplastic elastomer composition of the present invention can be formed into a two-layer molded article by, for example, laminating foams. Such a two-layered molded article can be produced, for example, by a powder molding method as disclosed in Japanese Patent Application Laid-Open No. 5-473, and a molded article composed of the separately produced thermoplastic elastomer composition of the present invention. It can also be manufactured by a method of bonding the foam and the foam with an adhesive or the like. In the case of the powder molding method, a layer made of the thermoplastic elastomer composition of the present invention containing no foaming agent is formed on the molding surface of the powder molding die according to the method described above, On top, a powder of a composition containing a foaming agent and a thermoplastic resin or a thermoplastic elastomer is further supplied, and the powders are heat-fused to form a new layer, and the composition further contains a foaming agent. It can be manufactured by foaming a layer of an object. In addition, a composite molded article having a structure of non-foamed layer / foamed layer / non-foamed layer can be produced by a method similar to the above. Here, the two non-foamed layers may be the same or different.

The same pyrolytic foaming agent as described above can be used as a foaming agent for producing the above-mentioned two-layer molded article or composite molded article. Examples of the thermoplastic resin or the thermoplastic elastomer contained in the composition containing the foaming agent include a vinyl chloride resin, a polyolefin resin, and an olefin thermoplastic elastomer. Further, as the composition containing the foaming agent, a polyethylene foamable composition disclosed in JP-A-7-228720 can also be used. Further, the foamed layer may be made of foamed polyurethane. In this case, since the thermoplastic elastomer composition of the present invention and polyurethane are generally inferior in adhesiveness, usually, the surface of the thermoplastic elastomer composition of the present invention is bonded by pretreatment with a primer such as chlorinated polyethylene. It is preferable to improve the properties. Incidentally, the foamed layer made of foamed polyurethane, for example, a mixed solution composed of a polyol, a polyisocyanate and a foaming agent is supplied between a molded body made of the thermoplastic elastomer composition of the present invention and a resin core material described later. Can be formed by foaming.

The molded article comprising the thermoplastic elastomer composition of the present invention described above or the composite molded article comprising a layer of the thermoplastic elastomer composition of the present invention and a foamed layer is used as a skin material of a resin molded article. Thus, a multilayer molded body can be formed. For example, a sheet made of the thermoplastic elastomer composition of the present invention can be bonded to a resin molded product as a skin material to form a two-layer molded product, and a layer of the thermoplastic elastomer composition of the present invention and a foamed layer. The resulting two-layer molded body can be formed into a three-layer molded body as a two-layer skin material by being bonded to the resin molded body on the foam layer side.

The resin constituting the resin molded body includes
Examples thereof include thermoplastic resins such as polyolefin resins such as polyethylene and polypropylene, and ABS resins (acrylonitrile-butadiene-styrene copolymer resin). Among them, a polyolefin resin such as polypropylene is preferably used.

The above-mentioned multilayer molded body can be produced, for example, by supplying a molten resin to one side of the skin material and applying pressure. The pressurization may be started after the supply of the resin is completed, or may be started before the supply of the resin is completed, and may be continued until the supply of the resin is completed. Further, the pressurization may be performed by clamping the molding apparatus, or may be performed by the supply pressure of the resin. Various methods such as an injection molding method, a low-pressure injection molding method, and a low-pressure compression molding method can be applied to the production of the above-mentioned multilayer molded body.
For example, using a molding apparatus including a pair of first and second mold members that can relatively freely move between an open position and a closed position, the first and second positions in the open position are used. A skin material including a layer made of the thermoplastic elastomer composition of the present invention is supplied between the mold members, and then a molten resin is supplied between the skin material and one of the mold members. After or while supplying the resin, the first and second mold members are relatively moved to compress the skin material and the resin, whereby a multilayer molded body can be manufactured.
For example, when a skin material comprising a layer made of the thermoplastic elastomer composition of the present invention and a foamed layer is used, in the above-described method, a melt is applied between the foamed layer of the skin material and a mold member facing the same. Supply the resin. In the above method, the supply of the resin between the skin material and the mold member can be performed, for example, from a resin passage provided in the mold member or a resin provided outside the molding device. The resin supply nozzle of the supply device may be inserted between the skin material and the mold member to supply the resin, and then the resin supply nozzle may be withdrawn. The moving directions of the first and second mold members are not particularly limited, and may be, for example, a vertical direction or a horizontal direction.

In the above method, the displacement of the skin material is smaller than in the injection molding method in which the molten thermoplastic resin is supplied while the first and second mold members are held in the closed positions, Moreover, it is more preferable because damage to the skin material can be avoided. When the skin material produced by the powder molding method described above is used, the mold used in the powder molding can be applied as a mold member for producing a multilayer molded body. In this case, usually, a mold for powder molding is attached to the first mold member while the skin material formed by powder molding is held on the molding surface, and thereafter, the same as described above. By performing the operation, a multilayer molded body is manufactured. According to this method, it is possible to manufacture a multilayer molded body without substantially damaging the pattern formed on the surface of the skin material by the powder molding.

The pair of mold members is, for example, a so-called pair of male and female mold members in which the outer peripheral surface of the first mold member and the inner peripheral surface of the second mold member can slide. Can be.
In this case, by setting the distance (clearance) between the inner peripheral surface and the outer peripheral surface to be substantially equal to the thickness of the skin material to be used, a multilayer molded body having an extra skin material at an end is manufactured. be able to. By folding this extra skin material toward the back surface of the multilayer molded body, a multilayer molded body whose end is covered with the skin material can be manufactured.

[0049]

The thermoplastic elastomer composition of the present invention can provide a molded article having excellent flexibility which does not easily whiten even when bent.

[0050]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Evaluation method [1] Complex dynamic viscosity η * (1) Dynamic analyzer (Rheometrics, R
DS-7700), using a parallel plate mode, an applied strain of 5%, a sample temperature of 250 ° C., a vibration frequency ω = 1 radian / second, and a storage viscoelastic modulus G ′ (1) and a loss viscoelastic modulus G of the sample. '' (1) was measured, and η ^* (1) was calculated from these values by the calculation formula (1).

[2] For the same sample used for the measurement of the Newtonian viscosity index n η ^* (1), except that the vibration frequency ω at the time of measuring the storage viscoelastic modulus and the loss viscoelastic modulus was set to 100 radians / second. Is used to measure the complex dynamic viscosity η ^* (100) in the same manner as the measurement of η ^* (1), and using the obtained η ^* (1) and η ^* (100),
N was calculated by the calculation formula (2).

[3] Content of 1-butene unit in ethylene / 1-butene copolymer rubber (1) Preparation of calibration curve Ethylene / propylene copolymer (ethylene unit content 7
3% by weight) and 5 types of mixtures containing 1-butene homopolymer at a predetermined ratio were hot-pressed at 150 ° C. to form films having a thickness of 0.05 mm. These films, using an infrared spectrometer to obtain the absorption ratio of the ethylene units derived peak (wave number 720 cm ^-1) and 1-butene units derived peak (wavenumber ^772cm-1),
In the mixture, the ratio of the content of 1-butene units to the total amount of ethylene units and 1-butene units is plotted on the horizontal axis,
A graph (calibration curve) having the absorbance ratio as the vertical axis was created.
The mixture of the ethylene / propylene copolymer and the 1-butene homopolymer was prepared by dissolving both in toluene in a single vessel, adding methanol, taking out the resulting precipitate, and drying. (2) Measurement of 1-butene unit content The ethylene / 1-butene copolymer rubber was heated to a temperature equal to or higher than its melting temperature and pressed to form a film having a thickness of 0.05 mm. For this film, the absorbance ratio between the peak derived from the ethylene unit and the peak derived from the 1-butene unit was determined using an infrared spectrometer, and ethylene-1-was determined using a calibration curve.
The 1-butene unit content in the butene copolymer rubber was determined.

[4] Content of 1-hexene unit in ethylene / 1-hexene copolymer rubber The ethylene / 1-hexene copolymer rubber was hot-pressed at 150 ° C. to form a film having a thickness of 0.05 mm. Created.
For this film, the carbon atom in the main chain of the ethylene / 1-hexene copolymer rubber was determined from the absorbance of the peak derived from the terminal methyl group of the n-butyl branch in the 1-hexene unit measured using an infrared spectrometer. The ratio of the number of terminal methyl groups of n-butyl branches to the number, that is, the degree of branching was calculated. From the degree of branching, the number of branched monomer units and the number of unbranched monomer units were calculated, and the 1-hexene unit content (% by weight) was calculated using these values. In addition, the branching degree was calculated using the following formula (4). Degree of branching (%) = {(f × A) / (t × d)} × 100 (4) f: coefficient (0.070 cm ² / g) A: absorbance t: film thickness (cm) d: ethylene · 1 -Density of hexene copolymer rubber (g / g)
cm ³ ) As the value of the coefficient f, reference by Usami and Takayama (2)
"Registration of Chemistry Special Issue No. 140 Infrared, Raman, Vibration [II]
Present and Future Prospects, published by Nankodo, edited by Naomichi Tsuboi et al., Characterization of Polyethylene by Infrared Absorption (pp. 73-81), 1983.

[5] Spherical average particle diameter of powder of thermoplastic elastomer composition 100 particles of the thermoplastic elastomer composition were randomly sampled, and the total weight thereof was determined. From this value and the specific gravity of the thermoplastic elastomer composition, an average volume per particle is calculated, the diameter of a sphere having the same volume as the average volume is calculated, and the value is calculated as the value of the powder of the thermoplastic elastomer composition. The sphere-converted average particle size was used.

[6] Bulk Specific Gravity of Powder of Thermoplastic Elastomer Composition The bulk specific gravity of thermoplastic elastomer powder was calculated according to JIS K-6721.

[7] Appearance of molded article In the obtained molded article, three convex portions A (7 mm in height and 5 mm in width), B (11 mm in height and 25 mm in width) and C (15 mm in height) shown in FIG. , Width 25 mm) was visually observed for the presence of pinholes and underfills at each edge, and evaluated according to the following criteria. ++: No pinhole or underfill was found at any of the edges of the projections A, B and C. +: No pinhole or underfill was found at the edges of the projections A and B, but pinholes or underfill were found at the edges of the projection C. -: No pinhole or underfill was found at the edge of the projection A, but pinholes or underfill were found at the edges of the projections B and C. -: Pinholes or underfills were observed at any of the edges of the projections A, B and C.

[8] Bending Whitening Test of Molded Body 500 gf or 1 kg was applied to the molded body bent at the center.
A load of f was applied for 1 minute, the load was removed thereafter, and the whitened state of the bent portion of the molded body was visually evaluated according to the following criteria. +: Almost no whitening was observed. -: Slight whitening was observed. -: Remarkable whitening was observed.

[9] Hardness of molded article Ten pieces of the molded article cut into 1 cm × 5 cm were piled up, and the Shore A hardness was measured using a durometer-Shore A hardness measuring machine.

Reference Example 1 EPDM [propylene unit content = 28% by weight, iodine
Price = 12, ML_{1 + 4}(100 ° C) = 242] and mineral oil
Softener (manufactured by Idemitsu Kosan Co., Ltd., Diana Process PW-38)
0) in a weight ratio of 1: 1 and ML_{1 + 4}(100 ° C)
Oil Exhibition EPDM 53 (Esplen E manufactured by Sumitomo Chemical Co., Ltd.)
670F) 50 parts by weight of 50 parts by weight of propylene
Tylene random copolymer resin (ethylene unit content = 5
Weight%, MFR = 90g / 10min) and 0.4 parts by weight
Bridge assistant (Sumitomo Chemical Co., Ltd., Sumifine BM, Bismalei
Amide compound) and using a Banbury mixer
Knead for 10 minutes, melt extrudate and extruder and pelletizer
Into a pellet (diameter 3 mm, length 6 mm). This
100 parts by weight of pellets and 0.1 part by weight of 2,3-dimethyl
Tyl-2,5-di (tert-butylperoxyno) hexa
(Sanperox APO manufactured by Sanken Kabushiki Kaisha)
Kneading at 220 ° C. using a mixer to perform dynamic crosslinking, η
^*(1) is 5.2 × 10^ThreePoise, n is 0.31
A product was obtained. The composition is then extruded from a twin screw extruder
And pelletize using a pelletizer (diameter 3 mm, length
6 mm).

REFERENCE EXAMPLE 2 1 liter of dry toluene was supplied into a 2 liter separable flask filled with nitrogen gas, and then a mixed gas of ethylene and 1-butene was supplied at normal pressure to the ethylene gas supply rate. = 9 NL / min, 1-butene gas supply rate = 2.
Heated to 30 ° C. while feeding at 5 NL / min. Then, the above-mentioned mixed gas was supplied, and the mixture was stirred at 30 ° C. for 0.2
5 g (1.25 mmol) of triisobutylaluminum are added, followed by 0.018 g (0.005 mmol) of (t) prepared according to the disclosure of JP-A-3-1630088.
ert- butylamido) dimethyl (tetramethyl-eta ⁵ - plus cyclopentadienyl) silane titanium dichloride. After stirring the obtained mixture at 30 ° C. for 15 minutes while supplying the mixed gas, 0.0023 g (0.023 g) was added.
(25 mmol) of triphenylcarbenium tetrakis (pentafluorophenyl) borane was added, and stirring was continued at 30 ° C. for another 30 minutes while supplying the mixed gas.
Thereafter, the polymerization reaction was stopped by adding 20 ml of methanol, the resulting mixture was poured into 10 liter of methanol, and the resulting precipitate was collected by filtration. The precipitate was dried at 80 ° C. under reduced pressure for 12 hours. Thus, 156 g of an ethylene / 1-butene copolymer rubber was obtained. This ethylene 1-
Table 1 shows the evaluation results of the butene copolymer rubber.

Reference Examples 3 to 6 An ethylene / 1-butene copolymer rubber was produced in the same manner as in Reference Example 2 except that the 1-butene gas supply rate, polymerization temperature and polymerization time were changed as shown in Table 1. did. Table 1 shows the evaluation results of the respective ethylene / 1-butene copolymer rubbers.

REFERENCE EXAMPLE 7 1 liter of dry toluene was supplied into a 2 liter separable flask filled with nitrogen gas. Then, while maintaining the temperature of the content at 0 ° C., 2 NL of ethylene gas at atmospheric pressure was added. / Min feed rate. While stirring the obtained mixture at 0 ° C, 126.2 g (1.5 mol) of 1-
Hexene and 0.25 g (1.25 mmol) of triisobutylaluminum are added.
No. 8, 0.018 g manufactured according to the disclosure
(0.005 mmol) of (tert-butylamido) dimethyl (tetramethyl-η ⁵ -cyclopentadienyl) silanetitanium dichloride was added. Continue with 0.0023
g (0.025 mmol) of triphenylcarbenium tetrakis (pentafluorophenyl) borane was added, and stirring was continued at 0 ° C. for 5 minutes while supplying the ethylene gas. Thereafter, the polymerization reaction was stopped by adding 20 ml of methanol, the resulting mixture was poured into 10 liter of methanol, and the resulting precipitate was collected by filtration. The precipitate was dried at 80 ° C. under reduced pressure for 12 hours. Thus, 119 g of an ethylene / 1-hexene copolymer rubber was obtained. Table 1 shows the evaluation results of the obtained ethylene / 1-hexene copolymer rubber.

[0064]

[Table 1]

Example 1 100 parts by weight of the composition prepared in Reference Example 1 and 5 parts by weight of the ethylene / 1-butene copolymer rubber prepared in Reference Example 2 were mixed at 190 ° C. using a twin-screw kneader. The mixture was kneaded to obtain a melt-kneaded product of the thermoplastic elastomer composition. The obtained melt-kneaded material was press-molded to obtain a sheet having a thickness of 1 mm. Table 2 shows the evaluation results of the thermoplastic elastomer composition subjected to molding and the obtained sheet.

Example 2 A thermoplastic elastomer composition and sheet were produced in the same manner as in Example 1 except that the amount of the ethylene / 1-butene copolymer rubber was changed to 10 parts by weight. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 3 A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 1 except that the amount of the ethylene / 1-butene copolymer rubber was changed to 20 parts by weight. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 4 Instead of 5 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 2, 10 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 3 was used. A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 1 except for the difference. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 5 A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 4, except that 20 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 3 was used. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 6 Instead of 5 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 2, 10 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 4 was used. A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 1 except for the difference. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 7 A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 6, except that 20 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 4 was used. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Comparative Example 1 Instead of 5 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 2, 10 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 5 was used. A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 1 except for the difference. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Comparative Example 2 Instead of 5 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 2, 10 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 6 was used. A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 1 except for the difference. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Comparative Example 3 A thermoplastic elastomer composition and a sheet were produced in the same manner as in Example 6, except that 20 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 6 was used. Table 2 shows the evaluation results of the thermoplastic elastomer composition and the sheet.

Example 8 66.7 parts by weight of a propylene / ethylene random copolymer resin (ethylene unit content = 4.5% by weight, MFR =
228 g / 10 min) and 33.3 parts by weight of ethylene / propylene copolymer rubber (Esprene V0 manufactured by Sumitomo Chemical Co., Ltd.)
141, propylene unit content = 27% by weight, MFR =
0.7 g / 10 min) using a twin-screw kneader to obtain a shear rate =
Knead at 1.2 × 10 ³ sec ^-1 and temperature = 200 ° C.
^{* A} composition was obtained in which (1) was 1.8 × 10 ³ poises and n was 0.12. Using a twin-screw kneader, 100 parts by weight of the composition thus obtained and 66.7 parts by weight of the ethylene / 1-butene copolymer rubber produced in Reference Example 3 were used.
The resulting mixture was kneaded at a temperature of ° C. to obtain a molten thermoplastic elastomer composition, which was press-molded to produce a sheet having a thickness of 1 mm. Table 2 shows the evaluation results of the obtained thermoplastic elastomer composition and sheet.

[0076]

[Table 2]

Example 9 A molten thermoplastic elastomer composition was produced in the same manner as in Example 3, and was processed into pellets (diameter 3 mm, length 6 mm) using a pelletizer. This pellet is
The mixture was cooled to 120 ° C. and further pulverized by a freeze pulverizer to obtain a thermoplastic elastomer composition powder. The powder had an average spherical equivalent particle diameter of 0.20 mm and a bulk specific gravity of 0.32. Nickel electroformed mold (30 mm ×
(30 mm, thickness 3 mm) was heated to 250 ° C., and 1 kg of the powder obtained above was sprinkled on the molding surface. After 14 seconds, the unfused powder was removed and the mold carrying the fused thermoplastic elastomer composition was heated in a 250 ° C. oven for 60 seconds. Thereafter, the mold was taken out of the heating furnace and cooled, and the formed body was removed from the mold. This molded product had a uniform thickness and had no pinhole. Table 3 shows the results of the evaluation of the molded body.

Example 10 The procedure of Example 9 was repeated except that the ethylene / 1-hexene copolymer rubber produced in Reference 7 was used instead of the ethylene / 1-butene copolymer rubber produced in Reference Example 2. Similarly, a thermoplastic elastomer composition and a sheet were produced. Table 3 shows the evaluation results of the obtained thermoplastic elastomer composition and sheet. Η ^* (1) of the thermoplastic elastomer composition was 1.2 × 10 ³ poise and n was 0.15.

[0079]

[Table 3]

Example 11 100 parts by weight of a propylene / ethylene random copolymer resin (ethylene unit content = 4.5% by weight, MFR = 2
28 g / 10 min) and 50 parts by weight of an ethylene / 1-butene copolymer rubber (1-butene unit content = 71% by weight, η ^*
(1) = 2.2 × 10 ³ poise, n = 0.2) and kneaded at 190 ° C. using a twin-screw kneader to obtain η ^* (1) =
A thermoplastic elastomer composition having 1.4 × 10 ³ poises and n = 0.13 was obtained. This composition was cooled to −100 ° C. using liquid nitrogen, and further pulverized using a freeze pulverizer to obtain a powder of a thermoplastic elastomer composition. The average sphere equivalent particle diameter of the powder is 0.20 mm, and the bulk specific gravity is 0.33.
Met. A nickel electroformed mold (30 mm × 30 mm, thickness 3 mm) having a grain pattern on a molding surface is heated to 250 ° C.
1 kg of the powder obtained above was sprinkled on the molding surface. After 14 seconds, the unfused powder was removed, and the mold containing the fused thermoplastic elastomer composition was placed at 250 ° C.
In a heating furnace for 60 seconds. Thereafter, the mold was taken out of the heating furnace and cooled, and the formed body was removed from the mold. Table 4 shows the evaluation results of the molded articles.

Example 12 η ^* (1) = 5 in the same manner as in Example 11 except that 200 parts by weight of ethylene / 1-butene copolymer rubber was used.
A thermoplastic elastomer composition having × 10 ³ poise and n = 0.18 was obtained. A powder of this composition was prepared in the same manner as in Example 11, and a molded article was produced. Table 4 shows the evaluation results of the obtained molded bodies.

Example 13 100 parts by weight of ethylene / 1-hexene copolymer rubber (1-hexene unit content = 70% by weight, η ^* (1) =
Η ^* (1) was 3 × 10 ² poise, n, except that 2 × 10 ² poise, n = 0.03) was used.
Was 0.04.
A powder of this composition was prepared in the same manner as in Example 11, and a molded article was produced. Table 4 shows the evaluation results of the obtained molded bodies.

Comparative Example 4 EPDM [propylene unit content = 28% by weight, iodine value = 12, ML _{1 + 4} (100 ° C.) = 242] and mineral oil softener (Diana Process PW-38, manufactured by Idemitsu Kosan Co., Ltd.)
0) and a ML _{1 + 4} (100 ° C.) of 53, oil-extended EPDM (Supreto Chemical Co., Ltd., Esplen E)
670F) 50 parts by weight of 50 parts by weight of a propylene / ethylene random copolymer resin (ethylene unit content =
4.5% by weight, MFR = 90 g / 10 minutes) and 0.6 part by weight of a crosslinking assistant (Sumitomo Chemical Co., Ltd., Sumifine BM, bismaleimide compound), and kneaded for 10 minutes using a Banbury mixer. Then, the kneaded composition was processed into pellets (diameter 3 mm, length 6 mm) using an extruder and a pelletizer. 100 parts by weight of the pellet and 0.4 parts by weight of 2,3
-Dimethyl-2,5-di (tert-butylperoxyno)
Hexane (Sanperox APO, manufactured by Sanken Kabushiki Kaisha)
200 ° C. using a twin screw extruder and a shear rate of 1.2 × 10
And kneaded with ³ seconds ^{over 1, η * (1)} is 1.5 × 10 ³ poise,
A composition having n of 0.25 was obtained. This composition was cooled to -120 ° C. using liquid nitrogen, and further pulverized using a freezing pulverizer to obtain a powder having a sphere-converted average particle size of 0.20 mm and a bulk specific gravity of 0.30. A molded article was produced in the same manner as in Example 11 except that the powder obtained above was used. Table 4 shows the evaluation results of the obtained molded bodies.

[0084]

[Table 4]

Example 14 (Production of powder of thermoplastic elastomer composition) Comparative Example 4
100 parts by weight of pellets of the kneading composition obtained in the same manner as
And 10 parts by weight of an ethylene / 1-butene copolymer rubber (1-butene unit content = 71% by weight, η ^* (1) =
2.2 × 10 ³ poise, n = 0.2) was supplied to a 30 mmφ extruder and kneaded at 160 ° C., and the resulting thermoplastic elastomer composition was extruded from a die having a discharge port diameter of 1.0 mm into one piece. The composition was extruded at a discharge speed of 1 kg / hr per discharge port, and the extruded composition was taken out at a take-up speed of 32 m / min and then cooled to produce a strand having a diameter of 0.8 mm. Cut this strand with a pelletizer,
A powder having an average sphere equivalent particle size of 0.91 mm and a bulk specific gravity of 0.465 was obtained. The η ^* (1) of the thermoplastic elastomer composition obtained by kneading was 1.7 × 10 ³ poise,
n was 0.21. (Production of molded body by powder slush molding method) The powder obtained above was subjected to powder slush molding using a molding apparatus schematically shown in FIG. First, the powder (3) obtained above is fed into a container (2), and then, as shown in FIG. 1, the container (2) and the mold (1) are separated by the periphery of each opening. They were fixed so as to be in close contact with each other. As shown in FIG. 2, the mold (1) has three concave portions on a molding surface,
That is, it has a concave portion (6) having a depth of 7 mm, a concave portion (7) having a depth of 11 mm and a concave portion (8) having a depth of 15 mm, and the opening of each concave portion is a square having a side length of 25 mm. Was. Further, the entire surface of the molding surface of the mold (1) had a grain pattern. The temperature of the mold (1) was 250 ° C. Immediately after the container (2) and the mold (1) are fixed, the two are fixed to one another about the rotation axis (4) using a uniaxial rotating device.
After being rotated by 80 °, the powder (3) was supplied onto the molding surface of the mold (1). Next, the container (2) and the mold (1) fixed to each other are reciprocated twice for 15 seconds within a range of an amplitude of 45 ° about the rotation axis (4) to melt the powder (3). The molten powder (3) was adhered to the molding surface of the mold (1). Thereafter, the fixed container (2) and the mold (1) are again rotated by 180 ° to return to the original position, and the powder (3) that has not adhered to the molding surface of the mold (1) is removed from the container (2). ). Next, the mold (1) to which the molten powder (3) was adhered was removed from the container (2), and this was heated in an oven at 250 ° C. for 2 minutes, and then cooled. Thereafter, the molded body (5) was removed from the mold (1). The obtained molded body (5) has a thickness of 1.2 mm.
And three protrusions, that is, a protrusion A having a height of 7 mm, a protrusion B having a height of 11 mm, and a protrusion C having a height of 15 mm. In each of the protrusions, the root portion was a square having a side of 25 mm. Further, the grain pattern applied to the molding surface of the mold (1) was accurately transferred to the surface of the molded body in contact with the mold (1). FIG. 3 shows a cross-sectional view of this molded body. Table 5 shows the evaluation results of the powder and the compact.

Example 15 At the time of producing a powder of a thermoplastic elastomer composition,
A molded article was produced in the same manner as in Example 14, except that the discharging speed of the composition from the die was 0.8 kg / hour and the take-up speed of the composition was 35 m / min. The average sphere-equivalent particle diameter of the powder used in the production of the molded product was 0.94 mm, and the bulk specific gravity was 0.
460. Table 5 shows the evaluation results of the obtained molded bodies.

Example 16 At the time of producing a powder of a thermoplastic elastomer composition,
Example 1 except that the take-off speed of the composition was 14 m / min.
In the same manner as in the above, a molded body was produced. The average sphere-equivalent particle diameter of the powder used for the production of the molded product was 1.25 mm, and the bulk specific gravity was 0.470. Table 5 shows the evaluation results of the obtained molded bodies.
Shown in

Example 17 100 parts by weight of ethylene / 1-hexene copolymer rubber (1-hexene unit content = 70% by weight, η ^* (1) =
A molded body was produced in the same manner as in Example 14 except that 2 × 10 ² poises, n = 0.03) was used. The average sphere-equivalent particle diameter of the powder used for the production of the molded product was 0.92 mm, and the bulk specific gravity was 0.460. In addition, η ^* (1) of the thermoplastic elastomer composition constituting the powder was 1.2 × 10 ³ poise, and n was 0.15. Table 5 shows the evaluation results of the obtained molded bodies.

Example 18 Pellets 100 of the kneading composition obtained in the same manner as in Comparative Example 4
Parts by weight and 10 parts by weight of an ethylene / 1-butene copolymer rubber (1-butene unit content = 71% by weight, η
^* (1) = 2.2 × 10 ³ poise, n = 0.2) was supplied to a twin-screw extruder and kneaded at 200 ° C., and then the resulting thermoplastic elastomer composition was discharged from the twin-screw extruder. It was extruded, cut by a cutting machine, and processed into pellets. The above thermoplastic elastomer composition has η ^* (1) of 1.7 × 10 ^3.
Poise, n was 0.21. The pellets of the obtained thermoplastic elastomer composition were subjected to -100 using liquid nitrogen.
C., crushed to 32 mesh (ie, 5 mesh).
A powder was obtained which passed through a Tyler standard sieve (00 μm × 500 μm aperture). The average spherical equivalent particle diameter of this powder is 0.20.
mm and bulk specific gravity was 0.290. Using this powder, a molded article was produced in the same manner as in Example 14. Table 5 shows the evaluation results of the powder and the compact.

Example 19 100 parts by weight of a composition obtained in the same manner as in Example 8 and 66.7 parts by weight of an ethylene / 1-butene copolymer rubber
(1-butene unit content = 71% by weight, η ^* (1) =
2.2 × 10 ³ poise, n = 0.2) was supplied to a 30 mmφ extruder and kneaded at 160 ° C., and the resulting thermoplastic elastomer composition was extruded from a die having a discharge port diameter of 1.0 mm into one piece. The composition was extruded at a discharge speed of 0.8 kg / h per discharge port, and the extruded composition was taken out at a take-up speed of 35 m / min and then cooled to produce a strand having a diameter of 0.8 mm. This strand was cut with a pelletizer to give a sphere-converted average particle size of 0.88 mm and a bulk specific gravity of 0.46.
0 was obtained. Incidentally, η ^* (1) of the thermoplastic elastomer composition obtained by kneading is 2 × 10 ³ poise,
n was 0.14. Using this powder, Example 14
In the same manner as in the above, a molded body was produced. Table 5 shows the evaluation results of the powder and the compact.

Comparative Example 5 100 parts by weight of the kneading composition obtained in the same manner as in Comparative Example 4 was
After the mixture was supplied to a 30 mmφ extruder and kneaded at 160 ° C., the composition was extruded from a die having a discharge port diameter of 1.0 mm at a discharge rate of 1 kg / hour per discharge port, and the extruded composition was treated for 32 m. / Min and then cooled to produce a 0.8 mm diameter strand. This strand was cut with a pelletizer to obtain a powder having a sphere-converted average particle size of 0.90 mm and a bulk specific gravity of 0.450.
Using the powder thus obtained, a molded body was produced in the same manner as in Example 14. Table 5 shows the evaluation results of the powder and the compact.

Comparative Example 6 Pellets of the kneading composition obtained in the same manner as in Comparative Example 4 were cooled to -100 ° C. using liquid nitrogen and pulverized to obtain a powder which passed through a 32 mesh Tyler standard sieve. . The average sphere-equivalent particle size of this powder is 0.18 mm, and the bulk specific gravity is 0.29.
It was 3. Using this powder, a molded article was produced in the same manner as in Example 14. Table 5 shows the evaluation results of the powder and the compact.

[0093]

[Table 5]

Example 20 (Production of powder of thermoplastic elastomer composition) 100 parts by weight of a propylene / ethylene random copolymer resin (ethylene unit content = 4.5% by weight, MFR = 228 g / l)
0 minutes) and 100 parts by weight of an ethylene / 1-butene copolymer rubber (1-butene unit content = 71% by weight)
After supplying to a mmφ extruder and kneading at 160 ° C., the resulting thermoplastic elastomer composition was extruded from a die having a discharge port diameter of 1.0 mm at a discharge rate of 1 kg / hour per discharge port, and the extruded thermoplastic elastomer composition was extruded. The composition was drawn off at a drawing speed of 32 m / min and then cooled to produce a 0.8 mm diameter strand. This strand was cut with a pelletizer, and the sphere-converted average particle diameter was 0.91 mm and the bulk specific gravity was 0.46.
0 was obtained. Η ^* (1) of the thermoplastic elastomer composition was 1.4 × 10 ³ poise and n was 0.13. (Production of molded article by powder slush molding method) A molded article was produced in the same manner as in Example 14, except that the powder obtained above was used. Table 6 shows the evaluation results of the obtained molded bodies.

Example 21 A powder of a thermoplastic elastomer composition was produced in the same manner as in Example 20, except that the amount of the ethylene / 1-butene copolymer rubber was changed to 200 parts by weight. The average sphere equivalent particle diameter of this powder was 0.94 mm, and the bulk specific gravity was 0.450. Incidentally, η of the above thermoplastic elastomer composition
^* (1) was 1.8 × 10 ³ poise and n was 0.15. Further, using this powder, a molded product was produced in the same manner as in Example 20. Table 6 shows the evaluation results of the obtained molded bodies.
Shown in

Example 22 Ethylene / 1-hexene copolymer rubber (1-hexene unit content = 70% by weight, η ^* (1) = 2 × 10 ² poises instead of ethylene / 1-butene copolymer rubber) , N = 0.
A molded article was produced in the same manner as in Example 20 except that 03) was used. The average sphere-equivalent particle diameter of the powder used in the production of the molded product was 0.93 mm, the bulk specific gravity was 0.458, and η ^* (1) of the thermoplastic elastomer composition constituting the powder was used.
Was 3 × 10 ² poise and n was 0.04. Table 6 shows the evaluation results of the obtained molded bodies.

Example 23 A powder of a thermoplastic elastomer composition was produced in the same manner as in Example 20, except that the take-up speed of the thermoplastic elastomer composition from the die was 14 m / min. The average sphere-equivalent particle diameter of this powder was 1.25 mm, and the bulk specific gravity was 0.450. Using this powder, a molded article was produced in the same manner as in Example 20. Table 6 shows the evaluation results of the obtained molded bodies.

Example 24 100 parts by weight of a propylene / ethylene random copolymer resin (ethylene unit content = 4.5% by weight, MFR = 2
28 g / 10 minutes) and 100 parts by weight of an ethylene / 1-butene copolymer rubber (1-butene unit content = 71% by weight) were supplied to a twin-screw extruder, kneaded at 200 ° C., and η
^{* A} thermoplastic elastomer composition in which (1) was 1.4 × 10 ³ poise and n was 0.13 was produced. This composition was extruded from the above twin screw extruder and further cut by a cutter to obtain pellets (3 mm in diameter and 6 mm in length) of the composition. Next, the pellet was cooled to -100 ° C using liquid nitrogen, and then pulverized to obtain a powder that passed through a 32-mesh Tyler standard sieve. The average sphere equivalent particle diameter of the powder is 0.20 m.
m and bulk specific gravity were 0.270. Using this powder, a molded article was produced in the same manner as in Example 20. Table 6 shows the evaluation results of the molded articles.

Comparative Example 7 In the same manner as in Comparative Example 4, pellets of a thermoplastic elastomer composition having η ^* (1) of 1.5 × 10 ³ poise and n of 0.25 were produced. After supplying these pellets to a 30 mmφ extruder and kneading at 160 ° C., the produced thermoplastic elastomer composition was discharged from a 1.0 mm die with a 1.0 mm die.
The extruded composition was extruded at a discharge speed of 1 kg / hour per discharge port, and the extruded composition was taken out at a take-up speed of 32 m / min and then cooled to produce a strand having a diameter of 0.8 mm. This strand was cut with a pelletizer to obtain a powder having a sphere-converted average particle size of 0.91 mm and a bulk specific gravity of 0.450. Using this powder, a molded article was produced in the same manner as in Example 20. Table 6 shows the evaluation results of the obtained molded bodies.
Shown in

Comparative Example 8 The pellets of the thermoplastic elastomer composition produced in Comparative Example 7 were cooled to −100 ° C. using liquid nitrogen, and then pulverized to obtain a powder that passed through a 32 mesh Tyler standard sieve. The average sphere-equivalent particle diameter of the powder was 0.18 mm, and the bulk specific gravity was 0.293. Using this powder, Example 20
In the same manner as in the above, a molded body was produced. Table 6 shows the evaluation results of the molded articles.

[0101]

[Table 6]

[Brief description of the drawings]

FIG. 1 is a schematic view of a molding apparatus for powder molding.

FIG. 2 is a plan view of a mold for powder slush molding from a molding surface side.

FIG. 3 is a cross-sectional view of a molded body manufactured using the mold of FIG. 2;

[Explanation of symbols]

1: mold for powder slush molding 2: container for containing thermoplastic elastomer composition powder 3: thermoplastic elastomer composition powder 4: rotating shaft 5: molded body 6: concave portion of mold 7: metal Concave part of mold 8: Concave part of mold A: convex part of molded body B: convex part of molded body C: convex part of molded body

 ──────────────────────────────────────────────────続 き Continuation of the front page (31) Priority claim number Japanese Patent Application No. 8-120355 (32) Priority date Hei 8 (May 15) May 15 (33) Priority claim country Japan (JP) (31) Priority Claim No. Japanese Patent Application No. Hei 8-124462 (32) Priority Date Hei 8 (1996) May 20 (33) Priority Country Japan (JP)

Claims (21)

[Claims] 1. An ethylene / α-olefin copolymer rubber (5-2) having (A) 100 parts by weight of a polyolefin resin and (B) an α-olefin unit content of 50% by weight or more.
50 parts by weight and (C) α-olefin unit content is 5
A thermoplastic elastomer composition containing 0 to 500 parts by weight of an ethylene / α-olefin copolymer rubber in an amount of less than 0% by weight. 2. The thermoplastic elastomer composition according to claim 1, wherein the α-olefin in the ethylene / α-olefin copolymer rubber (B) is an α-olefin having 4 to 8 carbon atoms. 3. The thermoplastic elastomer according to claim 1, wherein the ethylene / α-olefin copolymer rubber (B) is an ethylene / 1-butene copolymer rubber or an ethylene / 1-hexene copolymer rubber. Composition. 4. The method according to claim 1, wherein (C) the ethylene / α-olefin copolymer rubber is an ethylene / α-olefin copolymer rubber or an ethylene / α-olefin / non-conjugated diene copolymer rubber. Thermoplastic elastomer composition. 5. An oscillation frequency of 1 radian / 250 ° C.
Complex dynamic viscosity η ^* (1) measured in seconds is 1.5 × 10 ⁵
The thermoplastic elastomer composition according to claim 1, which has a poise or less. 6. eta ^* (1) and 250 complex dynamic viscosity measured at a vibration frequency 100 rad / sec at ° C. eta ^* (1
The thermoplastic elastomer composition according to claim 1, wherein the Newton viscosity index n calculated by the following formula using the following formula: n = {logη ^* (1) -logη ^* (100)} / 2 is 0.67 or less. Stuff. 7. The thermoplastic elastomer composition according to claim 1, wherein η ^* (1) is 1.5 × 10 ⁵ poise or less and n is 0.67 or less. 8. A polyolefin resin (A), (B) α-
An ethylene / α-olefin copolymer rubber having an olefin unit content of 50% by weight or more and (C) an ethylene / α having an α-olefin unit content of less than 50% by weight
The thermoplastic elastomer composition according to claim 1, wherein at least one or more selected from olefin copolymer rubbers are crosslinked intramolecularly and / or intermolecularly. 9. The thermoplastic elastomer composition according to claim 1, further comprising a foaming agent. 10. The powder comprising the thermoplastic elastomer composition according to claim 1, which has an average sphere-equivalent particle diameter of 1.2 mm or less and a bulk specific gravity of 0.38 or more. 11. The η of the thermoplastic elastomer composition
^* The powder according to claim 10, wherein (1) is 1.5 × 10 ⁵ poise or less and n is 0.67 or less. 12. The powder according to claim 10, wherein the α-olefin in the ethylene / α-olefin copolymer rubber (B) of the thermoplastic elastomer composition is an α-olefin having 4 to 8 carbon atoms. 13. The thermoplastic elastomer composition according to claim 1, wherein the ethylene / α-olefin copolymer rubber (B) is ethylene / 1.
The powder according to claim 10, which is -butene copolymer rubber or ethylene / 1-hexene copolymer rubber. 14. The powder according to claim 10, which is produced by a solvent treatment method, a strand cut method or a die face cut method. 15. A molded article comprising the thermoplastic elastomer composition according to claim 1. 16. The method according to claim 1, which is manufactured by a press molding method.
The molded article according to 5. 17. The molded article according to claim 15, wherein the powder of the thermoplastic elastomer composition according to claim 1 is formed by powder molding. 18. The molded product according to claim 15, which is produced by subjecting the powder according to claim 10 to powder molding. 19. The molded article according to claim 15, which is a foam molded article. 20. A multilayer molded article having at least one layer comprising the thermoplastic elastomer composition according to claim 1. 21. The multilayer molded article according to claim 20, further comprising a thermoplastic resin core layer.