JP3128979B2 - Composite foam molded article and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite foam molded article obtained by integrating a non-foamed layer formed from a thermoplastic elastomer powder composition and a foamed layer formed from a foamable powder composition, and its production. About the method.

[0002]

2. Description of the Related Art In recent years,
As a skin material such as an interior material for an automobile, a material which is lightweight, has excellent softness, and has a complex pattern such as a grainy pattern or a stitch pattern having a high-quality feeling is required. On the other hand, as a method of producing a cushioning skin material, a skin material in which a urethane material is injected and foamed in the same manner as a conventional vacuum molded product after foaming a vinyl chloride-based resin composition by a powder molding method, and a urethane bonded skin. Methods for producing materials are known. A method has also been proposed in which a non-foamed layer made of a vinyl chloride resin and a foamed layer made of a vinyl chloride resin are simultaneously and integrally molded by a powder molding method.

However, according to these methods, complicated patterns can be formed, and although the obtained skin material is excellent in soft feeling, it is not only inferior in lightness but also generates acidic substances by incineration at the time of end-of-life vehicles, and causes air pollution. However, it has a drawback derived from vinyl chloride that causes acid rain and the like and is inferior in cleanliness, and cannot be sufficiently satisfied.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present inventors have attempted to produce a cushioning skin material which is excellent in cleanliness, lightweight and soft, and has a complicated pattern. As a result of intensive studies on the powder molding method, it was found that the object could be achieved by using a specific thermoplastic elastomer powder as the raw material of the non-foamed layer, and further various studies were carried out to complete the present invention.

That is, the present invention relates to a non-foamed layer formed from the following thermoplastic elastomer powder composition (A), and (B) a polypropylene resin powder to (C) a pyrolytic foaming agent or (C) An object of the present invention is to provide a composite foam molded article obtained by integrating a foaming layer molded from a foamable composition containing a decomposable foaming agent and (D) a liquid coating agent, and a method for producing the same. (A) a thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin, or a partially crosslinked composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin A complex dynamic viscosity η ^* (1) at a frequency of 1 radian / sec at 250 ° C. of not more than 1.5 × 10 ⁵ poise, and the complex dynamic viscosity η ^* (1) A thermoplastic elastomer powder having a Newtonian viscosity index n of 0.67 or less, which is calculated using the following formula and a complex dynamic viscosity η ^* (100) at a frequency of 100 radians / second. n = {logη ^* (1) −logη ^* (100)} / 2

Hereinafter, the present invention will be described in detail. The present invention relates to a thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin, or an ethylene / α-olefin-based copolymer rubber and a polyolefin-based material. It is characterized by using a thermoplastic elastomer powder composed of a partially crosslinked elastomer composition obtained by dynamically crosslinking a mixture with a resin in the presence of a crosslinking agent, and an ethylene / α-olefin copolymer Examples of the rubber include a rubber containing an olefin as a main component, such as an ethylene / propylene copolymer rubber and an ethylene / propylene / non-conjugated diene copolymer rubber. Examples of the non-conjugated diene include dicyclopentadiene, ethylidene norbornene, 1,4-hexadiene, cyclooctadiene, and methylene norbornene. Above all,
Ethylene / propylene / ethylidene norbornene rubber (hereinafter referred to as EPDM) is preferable, and when it is used, an elastomer powder having excellent heat resistance, tensile properties and the like can be obtained.

The Mooney viscosity of the ethylene / α-olefin copolymer rubber (the Mooney viscosity (ML _{1 + 4} 100 ° C.) measured at 100 ° C. according to ASTM D-927-57T) is usually 130 or more and 350 or less. Preferably it is 200 or more and 300 or less. It is also preferable to use an oil-extended olefin-based copolymer rubber obtained by adding a mineral oil-based softener such as a paraffin-based process oil to an ethylene / α-olefin-based copolymer rubber, in which case the melt fluidity is improved. In addition, the flexibility of the molded body is improved. Mineral oil softener content is ethylene
Usually per 100 parts by weight of α-olefin copolymer rubber
30 to 120 parts.

As the polyolefin resin, polypropylene, a copolymer of propylene and ethylene, and a copolymer of propylene and an α-olefin other than propylene are preferably used. In particular, by using a copolymer resin of propylene and butene, the hardness of the molded article can be reduced. Melt flow rate of polyolefin resin (MFR, JIS K-7210, 230 ℃, 2.16kg
If the load is less than 20 g / 10 min, the powder is less likely to adhere to each other during powder molding and the strength of the molded body is reduced.
It is preferably at least 50 g / 10 minutes.

The thermoplastic elastomer used in the present invention is a composition of the above-mentioned ethylene / α-olefin copolymer rubber and a polyolefin resin, or a partially crosslinked composition obtained by dynamically crosslinking the composition. The ratio of the ethylene / α-olefin-based copolymer rubber to the olefin-based resin is usually preferably 5:95 to 80:20 by weight.

In preparing a partially crosslinked composition, an organic peroxide is usually used as a crosslinking agent. As the organic peroxide, a dialkyl peroxide is preferably used. In addition, it is preferable to dynamically crosslink using a very small amount of an organic peroxide in the presence of a crosslinking assistant such as a bismaleimide compound. In this case, the ethylene / α-olefin copolymer rubber is appropriately crosslinked and heat resistant. At the same time, high fluidity can be realized. The crosslinking agent is used in an amount of 1.5 parts by weight or less, preferably 0.6 parts by weight or less, based on 100 parts by weight of the composition of the ethylene / α-olefin-based copolymer rubber and the polyolefin-based resin.
It is used in an amount of not more than 0.1 part by weight, preferably not more than 0.1 part by weight, more preferably not more than 0.07 part by weight.

As an apparatus used for dynamic crosslinking, a continuous kneading extruder such as a single-screw kneading extruder or a twin-screw kneading extruder is preferably used. In the case of using a twin-screw kneading extruder, if the extrusion crosslinking is performed at a shear rate of <10 ³ sec ^-1 , ethylene-α-
Since the dispersion particle size of the olefin copolymer rubber becomes large and it becomes difficult to realize the viscosity condition of the present invention, it is preferable to carry out continuous extrusion crosslinking at a shear rate of 10 ³ sec ^-1 .

The thermoplastic elastomer of the present invention comprises:
The complex dynamic viscosity η ^* (1) measured at 250 ° C. and a frequency of 1 radian / sec is 1.5 × 10 ⁵ poise or less, preferably 1.0 × 10 ⁵ poise
Less than ⁵ poise. If it exceeds 1.5 × 10 ⁵ poise, the powder of the elastomer does not melt and flow on the mold surface, and cannot be molded by a powder molding method having a very low shear rate of 1 sec ⁻¹ or less during processing. The complex dynamic viscosity η ^* (1) measured at 250 ° C. and a frequency of 1 radian / sec and the complex dynamic viscosity η ^* (100) measured at a frequency of 100 radian / sec
And the Newtonian viscosity index n calculated by the following equation is 0.
It is 67 or less, preferably 0.60 or less. n = {logη ^* (1) −logη ^* (100))} / 2 If the Newton viscosity index n exceeds 0.67, the frequency 1
Complex dynamic viscosity η ^* (1) measured in radians / second is 1.5 ×
Even if it is less than 10 ⁵ poise, the frequency dependence of the complex dynamic viscosity becomes large, and the molding pressure during molding is very small, such as 1 kg / cm ² or less. The heat fusion between them becomes incomplete and only a molded article having low mechanical properties can be obtained.

The thermoplastic elastomer composition used in the present invention is obtained by blending not more than 50 parts by weight of an uncrosslinked ethylene-α-olefin copolymer rubber or ethylene-α-olefin copolymer resin with respect to 100 parts by weight of the elastomer. To improve the flexibility of the molded article. In this case, as the α-olefin, propylene, butene, or the like is used alone or in combination. In particular, an ethylene-propylene copolymer rubber having an ethylene content of 40 to 90% by weight, preferably 70 to 85% by weight and having an ML _{1 + 4} 100 ° C. of 50 or less is preferred.

The thermoplastic elastomer powder of the present invention is usually produced by pulverizing the above-mentioned thermoplastic elastomer composition at a low temperature not higher than the glass transition temperature. For example, a freeze pulverization method using liquid nitrogen is suitably used. The elastomer composition pellets cooled to −70 ° C. or lower, preferably −90 ° C. or lower can be obtained by a mechanical pulverization method using an impact pulverizer such as a ball mill.
Pulverization at a temperature higher than -70 ° C is not preferable because the particle size of the pulverized elastomer powder becomes coarse and the powder moldability decreases. In order to prevent the polymer temperature from exceeding the glass transition temperature during the pulverization operation, a method that generates less heat and has a high pulverization efficiency is preferable. Further, it is preferable that the crushing device itself is cooled by external cooling.

It is preferable that the obtained elastomer powder is pulverized so that 95% or more of the total weight passes through a 32 mesh Tyler standard sieve. If the on-screen accumulation rate of 32 mesh exceeds 5%, it may be one of the causes of thickness unevenness during pulverization molding. This uneven thickness may cause unevenness in the flexibility of the molded product, and may be a factor that impairs the commercial value of the molded product, such as easily causing breakage wrinkles. Also, when powder molding is performed using the thermoplastic elastomer powder composition used in the present invention, when the molded body is released from the mold, the adherence to the inner surface of the mold is strong. May occur. To prevent this, the inner surface of the mold before molding can be coated by spraying a commonly used release agent, for example, dimethylpolysiloxane.

However, in order to continuously produce a large number of pieces, it is necessary to coat a release agent every time several pieces are molded, which leads to an increase in molding cost. In such a case, the mold material may be improved, but a methylpolysiloxane compound may be previously contained in the powder composition as an internally added mold release agent. In this case, the methylpolysiloxane compound may have a viscosity at 25 ° C. of 20 centistokes or more. The preferred viscosity range is between 50 and 5000 centistokes. If the viscosity is too high, the effect as a release agent is reduced. The content is 2 parts by weight or less per 100 parts by weight of the powder composition, and if it exceeds 2 parts by weight, heat fusion between the elastomer powders is hindered, and only a molded article having poor mechanical properties may be obtained. In addition, the mold release agent bleeds on the mold surface, and the mold may be contaminated, which is not preferable. The incorporation of the internally added release agent can be carried out at any time before and after powdering.

Further, the powder composition used in the present invention comprises:
Phenol, sulfite, phenylalkane,
The necessary amount of known heat stabilizers such as phosphite-based, amine-based or amide-based stabilizers, anti-aging agents, weather-resistant stabilizers, antistatic agents, metallic soaps, lubricants such as waxes, coloring pigments, and the like are contained. Can be. In containing, it may be carried out at any time before and after powdering.

Next, the foamable composition used for the foamed layer will be described. Examples of the polypropylene resin fat powder used in the foamable composition include homopolypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-butene random copolymer, and propylene-ethylene-butene tripolymer. And the like. These can be used in combination of two or more. Polypropylene resin powder is
Melt flow rate (MFR, JIS K-7210, 23
0 ° C, measured with a 2.16 kg load) is 3 g / 10 min or more,
Preferably, 95% or more of the total weight is of a particle size that passes through a 32 mesh Tyler standard sieve. Further, two or more thermoplastic synthetic resin powders can be used in combination.

The thermally decomposable foaming agent (C) used in the foamable composition of the present invention is not particularly limited as long as it decomposes when heated and melted in powder molding to generate a gas. Alternatively, an inorganic chemical blowing agent can be used. Specifically, azo compounds such as azodicarbonamide, 2,2′-azobisisobutyronitrile, azohexahydrobenzonitrile, diazoaminobenzene, benzenesulfonyl hydrazide, benzene-1,3-sulfonyl hydrazide, diphenyl sulfone Sulfonyl hydrazide compounds such as -3,3'-disulfonyl hydrazide, diphenyl oxide-4,4'-disulfonyl hydrazide, 4,4'-oxybis (benzenesulfonyl hydrazide), paratoluenesulfonyl hydrazide, and N, N'-di Nitrosopentamethylenetetramine, N, N'-dinitroso-
Examples include nitroso compounds such as N, N'-dimethylterephthalamide, azide compounds such as terephthalazide and p-tert-butylbenzazide, and inorganic compounds such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate. Can also be used. Of these, azodicarbonamide and 4,4′-oxybis (benzenesulfonyl hydrazide) are preferred. The thermal decomposition type foaming agent used in the present invention has a decomposition temperature of usually 120 to 200C, preferably 120 to 180C. The thermal decomposition type foaming agent is blended in an amount of 2 to 11 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the polypropylene resin powder.

Further, a foaming accelerator or a foaming aid can be used in combination for the purpose of lowering the decomposition temperature of the thermal decomposition type foaming agent. As the foaming accelerator or foaming aid, for example,
Inorganic salts such as zinc white, zinc nitrate, lead phthalate, lead carbonate, phosphate trichloride, and tribasic lead sulfate, metal soaps such as zinc fatty acid soap, lead fatty acid soap, cadmium fatty acid soap, borax, oxalic acid Urea, biurea, ethanolamine, glucose, glycerin and the like.

On the other hand, a foaming inhibitor can be used for the purpose of raising the decomposition temperature of the thermal decomposition type foaming agent. As the foam inhibitor, for example, maleic acid, fumaric acid, phthalic acid, maleic anhydride, organic acids such as phthalic anhydride, stearoyl chloride, halogenated organic acids such as phthaloyl chloride,
Nitrogen compounds containing polyhydric alcohols such as hydroquinone, fatty acid amines, amides, oximes, isocyanates, etc., sulfur compounds containing mercaptans, sulfides, etc., phosphates such as phosphites, dibutyltin malate, tin chloride , Tin compounds such as tin sulfate, and hexachlorocyclopentadiene.

In the present invention, the stability of the foam cell can be improved by using the liquid coating agent (D) together with the above-mentioned pyrolytic foaming agent. As the liquid coating agent, a coating agent that cures at room temperature to 220 ° C. is preferably used. For example, thermosetting coating agents for protecting the surface of plastics such as polysiloxane, melamine-based, urethane-based, fluorine-containing, etc., polyester resins such as unsaturated polyester, alkyd, oil-free alkyd, linear polyester resin, and melamine resin , Amino resins such as modified melamine resins, novolak type, β-methyl epichloro type, cycloaliphatic type, acyclic aliphatic type, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, chlorinated type, resorcinol Polyurethane resins such as epoxy resin such as mold, one-pack type of oil-modified, moisture-cured blocked polyurethane resin, two-pack type of catalyst-cured polyol-cured polyurethane resin, and acrylate esters such as organic solvent type, aqueous type and solventless type An acrylic resin having a methacrylic acid ester as a main monomer is cited. It is. Among these liquid coating agents, polysiloxane, acyclic aliphatic type and cycloaliphatic type epoxy resin,
Solventless acrylic resins such as methacrylic acid esters are preferred, and among them, cycloaliphatic epoxy resins that cure at room temperature to 150 ° C., and solventless acrylic resins such as methacrylic acid esters are particularly preferred. . The liquid coating agent is usually 50 to 50,000 cp at 25 ° C.
Although those having a viscosity of about s can be used, they can be diluted with a solvent at the time of use. In the present invention, an ordinary curing agent can be used in combination for the purpose of accelerating the curing of the liquid coating agent.

As a curing agent for the epoxy resin, for example,
Amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 2,4,6-tris (dimethylaminomethyl) phenol and meta-xylylenediamine; phthalic anhydride; hexahydrophthalic anhydride; methylnadic anhydride; Examples thereof include acid anhydrides such as pyromellitic anhydride, polyamide resins, and mixtures thereof. Examples of the curing agent for the acrylic resin include organic compounds such as dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, benzoyl peroxide, and laurocloperoxy. Peroxides include mixtures thereof.

The liquid coating agent is used in an amount of 0.1 to 8 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the polypropylene resin powder. The acid anhydride is usually blended in an amount of 100 parts by weight or less, and the amine type and the peroxide type are mixed in an amount of 3 parts by weight. In preparing an effervescent composition by blending the above-mentioned agents, usually, (B)
A pyrolytic foaming agent is blended with the polypropylene resin powder, and then a liquid coating agent is blended.

The composite foam molded article of the present invention comprises (A) a non-foamed layer formed from the thermoplastic elastomer powder composition, (B) a polypropylene resin powder and (C) a pyrolytic foaming agent or The foaming layer formed from the foamable composition containing the (C) pyrolytic foaming agent and the (D) liquid coating agent is integrally formed, and a powder molding method is employed for molding. Examples of such a powder molding method include a fluid immersion method, a powder sintering method, an electrostatic coating method, a powder spraying method, a powder rotational molding method, a powder slush molding method (JP-A-58-132507), and the like. It is preferable to employ a powder slush molding method.

When powder slush molding is employed, for example, (1) a container having an opening containing a required amount of the thermoplastic elastomer powder of (A), and an opening heated sufficiently higher than the melting temperature of the powder; Is fixed to the mold with the opening, or fixed to the hollow part in the mold and integrated, and the powder is quickly rotated from the container to each part in the mold by rotating and / or swinging. Supplying, adhering, melting and discharging excess powder into the container,

(2) Next, a container having an opening in which a required amount of the foamable composition is put, and the non-foamed layer obtained in the step (1) heated to a temperature sufficiently higher than the melting temperature of the composition. And the mold is fixed by aligning the openings, or integrally fixed to the hollow portion in the mold, and rotating and / or swinging the foamable composition from the container to each part in the non-foamed layer. To quickly supply, adhere, melt, and discharge the excess powder composition into the container,

(3) Next, a composite foamed molded article can be produced by a step of heating and foaming the molded article obtained in (2).

The mold heating method used in the powder molding method is as follows.
There is no particular limitation, and examples thereof include a gas heating furnace method, a heating medium oil circulation method, a dipping method in a heating medium oil or hot fluidized sand or a high-frequency induction heating method, and foaming of the molten powder composition. These heating sources can also be used for this purpose. The molding temperature of the non-foamed layer of the present invention is usually 160 to 300 ° C., and preferably 1 to 300 ° C.
80-280 ° C. The molding time is not particularly limited, and is appropriately selected depending on the size of the molded body, the thickness of the molded body, and the like. The temperature at which the foamed layer of the present invention is foamed is usually 180 to 280 ° C, preferably 180 to 280 ° C.
260 ° C. The foaming time is not particularly limited, and is appropriately selected depending on the thickness of the foamed layer and the foaming ratio.

[0030]

According to the present invention, a non-foamed layer having a complicated shape is integrated with a foamed layer having uniform cells and a high expansion ratio according to the present invention. It is possible to manufacture a composite foam molded article which has been manufactured, and to produce a large composite foam molded article having a small residual distortion. In addition, a composite foam molded article excellent in lightness and cleanness can be provided.
The composite foam molded article of the present invention has excellent properties as described above and is used in various fields.

For example, in the automotive field, instrument panels, console boxes, armrests, headrests, door trims, rear panels, pillar trims, sun visors, trunk room trims, trunk lid trims, airbag storage boxes, seat buckles, headliners, glove boxes, steering wheels Interior covering materials such as wheel covers and ceiling materials, kick plates,
Suitable for interior parts such as change lever boots, ceiling materials, spoilers, side moldings, license plate housings, mirror housings, air dam skirts, mudguards, and other automotive exterior parts.

In the field of home appliances and OA equipment, for example, televisions, videos, washing machines, dryers, vacuum cleaners, coolers, air conditioners, remote control cases, microwave ovens, toasters, coffee makers, pots, jars, dishwashers, Suitable for electric razors, hair dryers, microphones, headphones, beauty equipment, CD / cassette storage boxes, personal computers, typewriters, projectors, telephones, copiers, facsimiles, telexes, and other skin materials and housings.

In the field of sports equipment, it is suitable for, for example, decorative parts for sports shoes, rackets for various ball games, grips for sports equipment and articles, saddle skins and handle grips for bicycles, motorcycles, and tricycles.

In the field of construction and housing, for example, furniture,
Skin materials for desks, chairs, etc., skin materials for gates, doors, fences, etc., wall decoration materials, ceiling decoration materials, curtain wall skin materials, kitchens,
Suitable for indoor flooring materials such as washrooms and toilets, outdoor flooring materials such as verandas, terraces, balconies, and carports, and rugs such as entrance mats, tablecloths, coasters, and ashtrays.

In the field of industrial products, it is suitable, for example, for grips and hoses of electric tools and their skin materials and packing materials. In addition to the above, it is suitable for, for example, bags, cases, files, notebooks, albums, stationery, camera bodies, skin materials such as dolls and other toys, molded articles such as watch bands, outer frames of foreheads and skin materials thereof. .

[0036]

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

The appearance of the skin side and the foam side of the composite foam molded article in the examples and comparative examples, the thickness of the composite foam molded article,
The state of the foam layer cell and the expansion ratio of the foam layer were evaluated as follows. The appearance skin layer on the skin side of the composite foam molded article was visually observed and evaluated as follows. ：: Good meltability, no pinholes observed. ×: Poor meltability, pinholes observed. The appearance foam layer on the foam side of the composite foam molded article was visually observed and evaluated as follows. ：: There is no unevenness in the thickness and the foam is uniformly formed. Δ: Thickness unevenness, but almost uniform foaming. X: Thickness unevenness is large and foaming is uneven. XX: Almost no foaming. The thickness of the non-foamed layer and the foamed layer of the composite foamed molded article were measured with a dial gauge manufactured by Toyo Seiki.

The state of the foam layer cell The cross section of the foam was visually observed and evaluated as follows. ：: The cells are uniform. Δ: Cells are slightly uneven. ×: The cells are non-uniform. Expansion ratio of foam layer The expansion ratio was calculated by the following equation. Expansion ratio = density of non-foamed layer / density of foamed layer The density of the foamed layer is a density meter (Dens manufactured by Toyo Seiki Seisaku-sho, Ltd.)
It was measured in water using an imeter-H).

The decomposition temperature of the pyrolytic foaming agent was measured as follows. The sample was placed in a capillary tube, heated at a rate of 2 ° C./min with a melting point measuring apparatus (MP type, Yanagimoto Seisakusho), and the temperature at which the sample started foaming was measured as a decomposition temperature. The dynamic viscoelasticity of the thermoplastic elastomer composition was measured as follows. Using a dynamic analyzer RDS-7700 manufactured by Rheometrics, frequency 1 at 250 ° C
The dynamic viscoelasticity at radians / sec and 100 radians / sec was measured in a parallel plate mode with a strain of 5%, and the complex dynamic viscosities η ^* (1) and η ^* (100) were calculated.

Example 1 Mineral oil-based softener (Diana Process PW # 380, manufactured by Idemitsu Kosan Co., Ltd.) per 100 parts by weight of EPDM (ML _{1 + 4} 100 ° C. = 242, propylene content = 28% by weight, iodine value = 12) ) Oil-extended EPDM with 100 parts by weight
(ML _{1 + 4} 100 ° C. = 53) 40 parts by weight, 60 parts by weight of a propylene / ethylene random copolymer resin (ethylene content = 5% by weight, MFR = 85 g / 10 minutes) and a crosslinking assistant (manufactured by Sumitomo Chemical; After kneading 0.4 part by weight of a registered trademark Sumifine BM (bismaleimide compound) using a Banbury mixer for 10 minutes, a pellet-like masterbatch for crosslinking (hereinafter referred to as MB) using an extruder. did. This M. B. 100 parts by weight of an organic peroxide (manufactured by Sanken Kako, registered trademark Samperox APO (2,5
-Dimethyl-2,5-bis (t-butylperoxy) hexane) was added at 0.04 parts by weight, and dynamically crosslinked at 220 ° C. using a twin-screw kneader (manufactured by Nippon Steel Works, registered trademark TEX # 44). Was carried out to obtain an elastomer composition pellet. After cooling the pellets to a temperature of −100 ° C. using liquid nitrogen, the pellets are freeze-ground and have a complex dynamic viscosity η ^* (1) of 3.1 × 10 ³ poise and a Newton viscosity index n of 0.2.
Thus, No. 4 thermoplastic elastomer powder for powder molding was obtained. 99% by weight of this powder is 32% of Tyler standard sieve.
It passed through a mesh sieve.

A nickel flat plate mold (30 cm × 30 cm) was heated in a gear oven at 300 ° C. When the surface temperature of the mold reached 220 ° C., the thermoplastic elastomer powder for powder molding was sprinkled for 5 seconds. Immediately after the excess powder is discharged, it is thermally decomposed to 100 parts by weight of a propylene-butene random copolymer resin powder (BH190G manufactured by Sumitomo Chemical Co., Ltd., butene content 24%, MFR 79.1 g / 10 minutes, average particle diameter 133 μm). Foaming agent azo compound CELLMIC C
AP-250 (manufactured by Sankyo Kasei Co., Ltd., main component: azodicarbonamide, decomposition temperature: 145 ° C.) 2.5 parts by weight of a foamable resin powder composition blended for 20 seconds, and an excessive powder composition was discharged. The mold was placed in a gear oven at an ambient temperature of 220 ° C. and heated for 60 seconds to foam the composition. Next, the mold was taken out of the gear oven, cooled with water, and the composite foam molded article was released from the mold.
Table 1 shows the evaluation results of the composite foam molded article.

Example 2 In Example 1, a propylene-ethylene random copolymer resin powder (RW160, manufactured by Sumitomo Chemical Co., Ltd., ethylene content: 5% by weight) was used in place of the propylene-butene random copolymer resin powder in the foamable resin powder composition. , MFR
A composite foam molded article was produced in accordance with Example 1 except that 116.5 g / 10 minutes and an average particle size of 138 μm) were used. Table 1 shows the evaluation results.

Example 3 In Example 1, a propylene-ethylene random copolymer resin powder (RW130 manufactured by Sumitomo Chemical Co., Ltd., ethylene content: 3% by weight) was used in place of the propylene-butene random copolymer resin powder in the foamable resin powder composition. , MFR
Example 1 except using 78g / 10min, average particle size 168μm)
A composite foam molded article was manufactured according to the standard. Table 1 shows the evaluation results.
Shown in

Example 4 In Example 1, a homopolypropylene powder (FL801 manufactured by Sumitomo Chemical Co., Ltd.) was used in place of the propylene-butene random copolymer resin powder in the foamable resin powder composition.
3, a composite foam molded article was produced in accordance with Example 1 except that MFR (132.1 g / 10 min, average particle size 137 μm) was used. Table 1 shows the evaluation results.

Example 5 Except that 60 parts by weight of a propylene-butene random copolymer resin (butene content = 24% by weight, MFR = 90 g / 10 minutes) was used, and that 40 parts by weight of oil-extended EPDM in Example 1 was used. Complex dynamic viscosity η ^{* under the} same conditions as in Example 1 ^.
(1) is 6.9 × 10 ³ poise, Newton viscosity index n
Was 0.39 to obtain a thermoplastic elastomer powder for powder molding. This powder passed 99% by weight through a 32 mesh Tyler standard sieve. 5 parts by weight of the same pyrolytic foaming agent as in Example 1 was added to 100 parts by weight of the same powder as this powder to obtain a foamable thermoplastic elastomer powder composition. Hereinafter, a composite foam molded article was manufactured under the same conditions as in Example 1, and the evaluation results of the composite foam molded article are shown in Table 1.

Example 6 50 parts by weight of a propylene-ethylene random copolymer resin (ethylene content = 3% by weight, MFR = 60 g / 10 min) was used, and 40 parts by weight of the oil-extended EPDM in Example 1 was 50 parts by weight. A thermoplastic elastomer powder for powder molding having a complex dynamic viscosity η ^* (1) of 3.4 × 10 ⁴ poise and a Newtonian viscosity index n of 0.59 was obtained under the same conditions as in Example 1 except that Was. This powder passed 99% by weight through a 32 mesh Tyler standard sieve. Example 1 was added to 100 parts by weight of a powder similar to this powder.
5 parts by weight of the same thermally decomposable foaming agent as in Example 1 was blended to obtain a foamable thermoplastic elastomer powder composition. Hereinafter, a composite foam molded article was manufactured under the same conditions as in Example 1, and the evaluation results of the composite foam molded article are shown in Table 1.

Comparative Example 1 50 parts by weight of a propylene-ethylene random copolymer resin (ethylene content = 3% by weight, MFR = 10 g / 10 min) was used, and 40 parts by weight of the oil-extended EPDM in Example 1 was 50 parts by weight. A thermoplastic elastomer powder having a complex dynamic viscosity η ^* (1) of 2.3 × 10 ⁵ poise and a Newton viscosity index n of 0.76 was obtained under the same conditions as in Example 1 except that 99% by weight of this powder passed through a 32 mesh Tyler standard sieve. Hereinafter, a composite foam molded article was manufactured under the same conditions as in Example 1, and the evaluation results of the composite foam molded article are shown in Table 1.

Comparative Example 2 EPDM (ML _{1 + 4} 100 ° C. = 86, propylene content =
50 weight%, iodine value = 8) 60 weight parts and EPM (ML
_{1 + 4} 100 ° C = 143, propylene content = 53% by weight)
20 parts by weight and homopolypropylene (MFR = 10g / 10min)
20 parts were kneaded with a Banbury mixer. This one
0.28 parts by weight of Samperox APO per 100 parts by weight was added and dynamically crosslinked with a twin-screw kneader to obtain elastomer composition pellets. This was ground in the same manner as in Example 1 to obtain a thermoplastic elastomer powder having a complex dynamic viscosity η ^* (1) of 5.7 × 10 ⁵ poise and a Newton viscosity index n of 0.79. 99% by weight of this powder passed through a 32 mesh Tyler standard sieve. Hereinafter, a composite foam molded article was manufactured under the same conditions as in Example 1. Table 1 shows the evaluation results.

Comparative Example 3 40 parts by weight of a mineral oil-based softener (Diana Process PW-380) were added per 100 parts by weight of EPDM (ML _{1 + 4} 100 ° C. = 145, propylene content = 36% by weight, iodine value = 10). 52 parts by weight of oil-extended EPDM (ML _{1 + 4} 100 ° C. = 78), 27 parts by weight of homopolypropylene (MFR = 20 g / 10 min), propylene-butene random copolymer (butene content
21% by weight of 24%, MFR = 4g / 10min) and 0.2 part by weight of a crosslinking agent (Suofine BM) were kneaded with a Banbury mixer. 0.23 parts by weight of an organic peroxide (Sanperox TY-1,3 manufactured by Sanken Kako Co., Ltd.) was added per 100 parts by weight, and dynamically cross-linked by a twin-screw kneader to obtain elastomer composition pellets. . This was ground in the same manner as in Example 1 to obtain a thermoplastic elastomer powder having a complex dynamic viscosity η ^* (1) of 1.9 × 10 ⁵ poise and a Newtonian viscosity index n of 0.83. 99% by weight of this powder passed through a 32 mesh Tyler standard sieve. Hereinafter, a composite foam molded article was manufactured under the same conditions as in Example 1. Table 1 shows the evaluation results.

Comparative Example 4 A propylene-butene random copolymer resin powder was replaced with a polypropylene resin powder (Flowback B-200 manufactured by Sumitomo Seika, MFR 0.5 g / 10 min.
A composite foam molded article was produced in the same manner as in Example 1 except that the average particle size was 454 μm. Table 1 shows the evaluation results.

Example 7 The same procedure as in Example 1 was carried out except that the thermal decomposition type foaming agent CellMike CAP was used.
The procedure of Example 1 was repeated, except that 2.5 parts by weight of CellMike S (manufactured by Sankyo Kasei Co., Ltd., 4,4′-oxybis (benzenesulfonylhydrazide)) was used instead of -250 to obtain a composite foam molded article. The evaluation results are shown in Table 1.

Example 8 In Example 2, the foamable resin powder composition was
Example 2 with respect to 100 parts by weight of the same propylene-ethylene random copolymer resin powder used in Example 2,
2.5 parts by weight of the same pyrolytic foaming agent as used in Step 1, ethyl acetate 2
0.5 parts by weight of a liquid coating agent diluted with 0 ml (manufactured by Dainippon Ink and Chemicals, registered trademark Monosizer TD-1500; trimethylolpropane methacrylate), dicumyl peroxide (manufactured by Sanken Kako, registered trademark Samperox DC) -98) A composite foam molded article was produced in the same manner as in Example 2 except that a composition prepared by dissolving 0.005 parts by weight in 10 ml of methyl ethyl ketone was used. Table 1 shows the evaluation results.

Example 9 In Example 2, the foamable resin powder composition was
Example 2 with respect to 100 parts by weight of the same propylene-ethylene random copolymer resin powder used in Example 2,
2.5 parts by weight of the same pyrolytic foaming agent as used in (1), 0.5 part by weight of a liquid coating agent (Sumitomo Chemical Co., Ltd., registered trademark Sumiepoxy ELA115; cycloaliphatic epoxy resin polymerized from epichlorohydrin and bisphenol A) and curing A composite foam molded article was produced in the same manner as in Example 2 except that a composition containing 0.05 part by weight of the agent triethylenetetramine was used. Table 1 shows the evaluation results.

[0054]

[0055]

Example 10 A white pigment (Sumitoka Color, White PV-742) was added to the thermoplastic elastomer powder obtained in the same manner as in Example 1.
0 parts by weight of a colored thermoplastic elastomer powder (5000 g of resin powder) is supplied to a super mixer having a capacity of 20 liters and mixed at 500 rpm for 10 minutes.
As a result, 5050 g of a white powder of the thermoplastic elastomer powder composition for powder molding (for a non-foamed layer) was obtained.

Further, a pigment (White PV, manufactured by Sumika Color Co., Ltd.) was added to the foamable resin powder composition obtained in the same manner as in Example 1.
1.0 part by weight of -742 0.7 parts by weight and -0.3 parts by weight of Black PV-817 were mixed to obtain 5150 g of a gray colored foamable resin powder composition.

Two rectangular containers (powder supply boxes) made of stainless steel as shown in FIGS. 1 to 3 are prepared, and one contains a thermoplastic elastomer powder composition for a non-foamed layer, and the other contains
4000 g of the foamable resin powder composition was supplied to the table. This rectangular container has a rectangular opening 1 of 600 mm × 220 mm, a depth of 210 mm, and is attached to a uniaxial rotating device 3.

On the other hand, the nickel electroforming mold shown in FIGS. 4 to 6 having the opening 1 of the powder supply box shown in FIG. 1 and the opening 4 having the same size was preheated in a gas furnace at 300 ° C. . This mold has a thickness of 3 mm, and has a complicated shape in which an inner surface is provided with a wrinkle pattern 5 and a grain pattern 6. When the surface temperature of the mold reaches 250 ° C., the heated mold is immediately placed in the opening 4 (600 mm × 220 m).
m) is directed downward, and is placed in the opening 1 of the powder supply box filled with the thermoplastic elastomer powder composition for the non-foaming layer, and the outer frame attached around both openings is placed. They were brought into close contact, fixed with clips 2 and integrated.

When the surface temperature of the mold reached 220 ° C., the powder supply box filled with the thermoplastic elastomer powder composition for the non-foamed layer was immediately rotated by 180 ° and the powder was brought into contact with the mold for 3 seconds. Fused. Immediately, the powder supply box was rotated back by 180 °, and excess powder attached to the complicated shape portion was blown off to the powder supply box. Immediately, the opening 4 of the mold on which the non-foamed layer is formed faces downward, and the opening 4 of the mold is inserted into the opening 1 of the powder supply box containing the expandable thermoplastic elastomer powder composition. Place them together and bring the outer frames attached around both openings into close contact.
And fixed. The surface temperature of the mold at this time was 189
° C.

Immediately, the powder supply box containing the foamable thermoplastic elastomer powder composition was rotated by 180 °, and the powder composition was brought into contact with the mold for 15 seconds to be fused. Next, the powder supply box was rotated back by 180 °, and the excess powder composition adhering to the complicated shape portion was blown off to the powder supply box. The mold was removed from the powder supply box with the mold opening 4 facing downward.
Subsequently, after the mold was post-heated in a heating furnace at 200 ° C. for 1 minute, it was immediately cooled with water and the molded article was released.

The obtained composite foamed molded article had a non-foamed layer of 1
The thickness was 20 g, the thickness was 0.7 mm, the foam layer was 110 g, the thickness was 3.3 mm, and the expansion ratio was 4.0. The non-foamed layer had no underfill or pinholes, and had a faithfully reproduced line pattern and grain pattern. The foam layer had uniform foam cells.

[0063]

[Brief description of the drawings]

FIG. 1 is a plan view of a powder supply box.

FIG. 2 is an elevation view of a powder supply box.

FIG. 3 is a side view of the powder supply box.

FIG. 4 is a plan view of a mold.

FIG. 5 is an elevation view of a mold.

FIG. 6 is a side view of a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Opening 2 ... Clip 3 ... Uniaxial rotation device (handle) 4 ... Opening 5 ... Latch pattern part in a mold 6 ... Mold inner grain pattern part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FIB29L 31:58 (72) Inventor Tadashi Hikasa 5-1, Anesaki Kaigan, Ichihara-shi, Chiba Sumitomo Chemical Co., Ltd. (72) Inventor Tsumori Hiroaki 51-1 Anesaki Beach, Ichihara City, Chiba Prefecture Sumitomo Chemical Co., Ltd. (56) References JP-A-5-228947 (JP, A) JP-A-5-473 (JP, A) (58) Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 41/00-41/52 B29C 44/00-44/60

Claims (4)

(57) [Claims] 1. A non-foamed layer formed from a thermoplastic elastomer powder composition of the following (A), and (C) a pyrolytic foaming agent or (C) a pyrolytic foam on polypropylene resin powder (B). A composite foam molded article obtained by integrating a foaming layer molded from a foamable composition containing a liquid agent and a liquid coating agent (D). (A) Powder of a thermoplastic elastomer comprising a composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin or a partially crosslinked composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin Wherein the complex dynamic viscosity η ^* (1) at a frequency of 1 radian / sec at 250 ° C. is 1.5 × 10 ⁵ poise or less, and the complex dynamic viscosity η ^{* is} Using (1) and the complex dynamic viscosity η ^* (100) at a frequency of 100 radians / second, the Newtonian viscosity index n calculated by the following equation is 0.
A thermoplastic elastomer powder of 67 or less. n = {logη ^* (1) −logη ^* (100)} / 2 2. The molded article according to claim 1, wherein a polypropylene resin powder having a melt flow rate of 3 g / 10 minutes or more is used as the polypropylene resin powder (B). 3. A non-foamed layer comprising the following thermoplastic elastomer powder composition (A), and (B) a polypropylene-based
After the resin powder is integrally molded with a foaming layer made of a foamable composition obtained by blending (C) a pyrolytic foaming agent or (C) a pyrolytic foaming agent and (D) a liquid coating agent, heating is performed. A method for producing a composite foam molded article. (A) Powder of a thermoplastic elastomer comprising a composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin or a partially crosslinked composition of an ethylene / α-olefin-based copolymer rubber and a polyolefin-based resin A complex elastomer having a complex dynamic viscosity η ^* (1) at a frequency of 1 radian / second at 250 ° C. of 1.5 × 10 ⁵ poise or less;
And thermally Newtonian viscosity index n calculated by the following equation using the complex dynamic viscosity eta ^* (100) in the complex dynamic viscosity eta ^* (1) and the frequency of 100 rad / s is 0.67 or less Plastic elastomer powder. n = {logη ^* (1) −logη ^* (100)} / 2 4. The method according to claim 3, wherein a polypropylene resin powder having a melt flow rate of 3 g / 10 min or more is used as the polypropylene resin powder (B).