JP2970105B2 - 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 made of a thermoplastic elastomer powder and a foamed layer made of a polyethylene resin powder, and a method for producing the same.

More specifically, the present invention relates to a non-foamed layer which has a complicated shape, a light weight, an excellent softness, and which can easily produce a high-grade grained or stitched pattern without residual strain. The present invention relates to a composite foam molded article in which a foam layer having a uniform cell and a smooth surface and a high foaming ratio is integrally molded by a simple molding operation, and a method for producing the same.

[0003]

2. Description of the Related Art In recent years,
As a covering material for an automobile interior material, a material which is lightweight, has excellent softness, and is provided with a luxurious leather grain pattern or stitch pattern has been required more and more.

Conventionally, a powder molding method using a vinyl chloride resin powder composition has been spotlighted as such a covering material.

The feature of this powder molding is that a mold at a temperature of 180 ° C. or more and a powder supply box are integrated and rotated, oscillated, or sprayed to weld the powder to the inner surface of the mold.
Unwelded powder is to be collected automatically or forcibly into a powder supply box (Japanese Patent Application Laid-Open No. 58-132507).

[0006] Next, the covering material produced by the powder molding method is formed by injecting and foaming a urethane raw material and bonding the same as in the case of a conventional vacuum molded product, thereby obtaining a final molded product. This urethane foam plays a role of imparting cushioning properties. However, this urethane-bonded product has unfavorable aspects such as the fact that the amine compound at the time of urethane foaming significantly promotes discoloration of the covering material of the vinyl chloride resin, and the urethane raw material is expensive.

Further, it has been attempted to produce a cushioning covering material 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. Although this covering material achieves the purpose of easily forming a soft grained and stitched pattern with an excellent softness, it also has the problem of recycling, waste disposal, and disposal of end-of-life vehicles. There are inconveniences such as the problem of air pollution of acidic substances caused by incineration of interior materials.

Against this background, recently, a covering material obtained by vacuum forming an olefin-based thermoplastic elastomer (hereinafter referred to as TPO) sheet has been developed. TPO vacuum molded products have a better effect than vinyl chloride resin in terms of lightness and clean materials, and achieve the purpose, but have a complex texture with high-quality leather grain or stitch pattern. It is difficult to shape a material having an irregular shape, and a large residual strain is generated during vacuum forming, and a crack may occur when used for a long period of time. Furthermore, vacuum-formed products are formed from sheets, resulting in poor product yields and high costs.

[0009]

In view of such circumstances, the present inventors have developed a method of forming a non-foamed layer and a foamed material by using a clean material that maintains high fluidity even when little pressure and shear force are applied during shaping. As a result of intensive studies on the production of a composite foam molded body with integrated layers, the powder molding method eliminates residual distortion and warpage of the molded body, forms complicated shapes such as sharp edges and overhangs, and Thus, the present inventors have found that a composite foam molded article having a uniform cell and a smooth surface and a high expansion ratio can be produced, and the present invention has been completed by further various studies.

That is, the present invention relates to a composite foamed molded article in which a non-foamed layer and a foamed layer are integrated, wherein the non-foamed layer is formed from a thermoplastic elastomer powder of the following (A). Is the following (B) polyethylene resin powder and (C) a pyrolytic foaming agent, or (C)
An object of the present invention is to provide a composite foam molded article characterized in that it is a layer formed by blending and foaming a pyrolytic foaming agent and (D) a liquid coating agent. (A) A thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin copolymer rubber and a polyolefin resin, or a mixture of an ethylene / α-olefin copolymer rubber and a polyolefin resin as a crosslinking agent Is a thermoplastic elastomer powder composed of a partially crosslinked elastomer composition dynamically crosslinked in the presence of
Complex dynamic viscosity η ^* (1) measured in radians / second is 1.
5 × 10 ⁵ poise or less and frequency 1 radian /
The Newtonian viscosity index n calculated using the complex dynamic viscosity η ^* (1) in seconds and the complex dynamic viscosity η ^* (100) at a frequency of 100 radians / sec is 0.67 or less. Thermoplastic elastomer powder. n = {logη ^* (1) −logη ^* (100)} / 2 (B) A powder made of a polyethylene resin, JI
A polyethylene resin powder having an MFR (melt flow rate) of 3 g / 10 min or more measured by a method according to SK6760.

The present invention also relates to a method for producing a composite foam molded article, wherein a non-foamed layer and a foamed layer are integrally molded by a powder molding method and then heated. A foamable polyethylene obtained by blending (C) a pyrolytic foaming agent or (C) a pyrolytic foaming agent and (D) a liquid coating agent with a polyethylene resin powder of the following (B) as a foaming layer using a powder. An object of the present invention is to provide a method for producing a composite foam molded article, which comprises using a resin composition powder. (A) A thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin copolymer rubber and a polyolefin resin, or a mixture of an ethylene / α-olefin copolymer rubber and a polyolefin resin as a crosslinking agent Is a thermoplastic elastomer powder composed of a partially crosslinked elastomer composition dynamically crosslinked in the presence of
Complex dynamic viscosity η ^* (1) measured in radians / second is 1.
5 × 10 ⁵ poise or less and frequency 1 radian /
The Newtonian viscosity index n calculated using the complex dynamic viscosity η ^* (1) in seconds and the complex dynamic viscosity η ^* (100) at a frequency of 100 radians / sec is 0.67 or less. Thermoplastic elastomer powder. n = {logη ^* (1) −logη ^* (100)} / 2 (B) A powder made of a polyethylene resin, JI
A polyethylene resin powder having an MFR (melt flow rate) of 3 g / 10 min or more measured by a method according to SK6760.

Hereinafter, the present invention will be described in detail. The ethylene / α-olefin copolymer rubber used in the present invention is:
A rubber containing an olefin as a main component, for example, ethylene-propylene copolymer rubber, ethylene-propylene-
Non-conjugated diene copolymer rubber. Examples of non-conjugated dienes include dicyclopentadiene, ethylidene norbornene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and the like. Among them, ethylene-propylene-ethylidene norbornene rubber (hereinafter referred to as EPDM)
), An elastomer powder having excellent heat resistance, tensile properties and the like can be obtained. In particular, ASTM D-9
The Mooney viscosity (ML _{1 + 4} 100 ° C.) measured at 100 ° C. according to 27-57T is 130 to 350, preferably 200 to 300 per 100 parts by weight of an ethylene / α-olefin-based copolymer rubber. An oil-extended olefin-based copolymer rubber containing 30 to 120 parts by weight of a mineral oil-based softening agent such as a paraffin-based process oil is preferred in that the balance between tensile properties and fluidity can be achieved.

As the polyolefin resin, polypropylene or a copolymer of propylene and an α-olefin is preferably used. In particular, when propylene and an α-olefin copolymer resin are used, the hardness of the molded article can be reduced. 230 ° C according to JIS K-7210,
2.Melt flow rate (MF) measured at 16 kg load
R) is preferably 20 g / 10 min or more, particularly preferably 50 g / 10 min or more. A thermoplastic elastomer powder produced using a polyolefin resin having a melt flow rate of less than 20 g / 10 minutes only softens the powder at the time of molding the powder, so that the powders hardly adhere to each other, and a molded article having high strength is obtained. I can't. The mixing ratio of the ethylene / α-olefin-based copolymer rubber and the olefin-based resin is 5% by weight or more and 80% by weight or less of the ethylene / α-olefin-based copolymer rubber, and 20% by weight or more and 95% by weight or less of the olefin-based resin. It is preferred that

As a crosslinking agent for dynamically crosslinking a mixture of the ethylene / α-olefin copolymer rubber and the polyolefin resin, an organic peroxide is used. Dialkyl peroxide is preferably used as the organic peroxide. Furthermore, it is preferable to carry out dynamic crosslinking using a very small amount of an organic peroxide in the presence of a crosslinking assistant such as a bismaleimide compound. By doing so, ethylene-α-
The olefin copolymer rubber can be appropriately crosslinked to have heat resistance and at the same time to realize high fluidity. At this time, the crosslinking assistant 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 mixture of the ethylene / α-olefin-based copolymer rubber and the polyolefin-based resin. The organic peroxide as a crosslinking agent is also used in an amount of 0.2 parts by weight or less, preferably 0.1 parts by weight or less, more preferably 0.07 parts by weight or less.

As a device used for the dynamic crosslinking, a continuous kneading extruder such as a single screw kneading extruder or a twin screw kneading extruder is preferably used. In particular, it is preferable to carry out continuous extrusion crosslinking at a shear rate of ≥10 ³ sec ^-1 using a twin-screw kneading extruder. If extrusion crosslinking is performed at a shear rate of <10 ³ sec ⁻¹ , the dispersed particle size of the ethylene / α-olefin-based copolymer rubber becomes large, making it difficult to realize low viscosity.

The partially crosslinked elastomer composition produced under these conditions has a complex dynamic viscosity η ^* (1) measured at a frequency of 1 radian / sec in a dynamic viscoelasticity measurement at 250 ° C. of 1.5 × 10 ⁵ poise. Or less, preferably 1.0 × 10 ⁵
Less than poise.

When the complex dynamic viscosity η ^* (1) measured at a frequency of 1 radian / sec exceeds 1.5 × 10 ⁵ poise, the elastomer powder produced using such an elastomer composition is melted on a mold surface. The powder slush molding method, which has a very low shear rate of 1 / sec ^-1 or less during processing, makes molding impossible.

The partially crosslinked elastomer composition produced under these conditions has a complex dynamic viscosity η measured at a frequency of 1 radian / sec in a dynamic viscoelasticity measurement at 250 ° C.
^{* Using the} (1) and the complex dynamic viscosity η ^* (100) measured at a frequency of 100 radians / second, the Newtonian viscosity index n calculated by the following equation is 0.67 or less, preferably 0.60.
It is as follows. n = {logη ^* (1) −logη ^* (100)} / 2

If the Newtonian viscosity index n exceeds 0.67, even if the complex dynamic viscosity η ^* (1) measured at a frequency of 1 radian / sec is 1.5 × 10 ⁵ poise or less, the complex dynamic The frequency dependence of the viscosity increases, and the molding pressure during molding is very small, such as 1 kg / cm ² or less, such as powder molding. Only a molded article with low physical properties can be obtained.

The elastomer used in the present invention may be an uncrosslinked ethylene-α-olefin copolymer rubber or an ethylene-α-olefin copolymer resin.
By blending 50 parts by weight or less with respect to 0 parts by weight, an elastomer having excellent flexibility can be obtained. In this case, as the α-olefin, propylene, butene, or the like is used alone or in combination. In particular, the ethylene content is 40 to 90% by weight, preferably 70 to 85% by weight.
ML 1 _{+ 4} 100 with ethylene-propylene copolymer rubber
Those having a temperature of 50 ° C. or less are preferred.

In the present invention, the pulverization of the elastomer composition is preferably performed by a freeze pulverization method using liquid nitrogen. −
The elastomer composition pellets cooled to 70 ° C. or lower, preferably −90 ° C. or lower can be obtained by a mechanical grinding method using a ball mill or the like. Pulverization at a temperature higher than -70 ° C is not preferable because the particle size of the pulverized elastomer powder becomes coarse and 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.

The obtained elastomer powder is preferably ground to such an extent that 95% or more of the total weight passes through 32 mesh of a Tyler standard sieve. If the cumulative ratio on the 32 mesh sieve exceeds 5%, this is one of the causes of thickness unevenness during pulverization molding. The thickness unevenness gives unevenness to the flexibility of the molded product, and becomes a factor that impairs the commercial value of the molded product, such as easily causing breakage wrinkles.

Next, the polyethylene resin powder used in the present invention is 190 ° C. in accordance with JIS K6760.
2. MFR (melt flow rate) measured under a load of 16 kg is 3 g / 10 min or more, more preferably 4 to 80 g /
It is a powder showing 10 minutes.

When the MFR is less than 3 g / 10 minutes, the meltability of the powder is reduced, and the powder is only softened, but the powders are hard to adhere to each other, and a molded article having high strength cannot be obtained.

The average particle size of the polyethylene resin powder used in the present invention is not more than 32 mesh, preferably not more than 40 mesh on a Tyler standard sieve. If the average particle size of the powder exceeds 32 mesh, unevenness of the surface of the molded product and uneven color due to poor dispersion of the colorant will occur.

The pulverization of the polyethylene resin used in the present invention includes a pulverization method at a low temperature. For example, it is a freeze grinding method using liquid nitrogen, and is usually ground at -120 ° C.

One of the features of the present invention is as described above.
An elastomer having a specific viscoelasticity that can be powder molded,
For example, pulverized at a low temperature equal to or lower than the glass transition temperature to form a powder, and the powder is used as a non-foamed layer.On the other hand, a pyrolytic foaming agent, or a pyrolytic foaming agent and a liquid coating agent in a powdered polyethylene resin powder. The compounded foam is a composite foam molded article obtained by integrating a non-foamed layer and a foamed layer as a foamed layer by blending.

The thermal decomposition type foaming agent used in the present invention is not particularly limited as long as it decomposes when heated and melted in powder molding to generate gas, and a general organic or inorganic chemical foaming agent can be used. it can. Specifically, azo compounds such as azodicarbonamide, 2,2'-azobisisobutyronitrile, azohexahydrobenzonitrile, diazoaminobenzene, benzenesulfonylhydrazide, benzene-
1,3-sulfonylhydrazide, diphenylsulfone-
Sulfonyl hydrazide compounds such as 3,3'-disulfonyl hydrazide, diphenyl oxide-4,4'-disulfonyl hydrazide, 4,4'-oxybis (benzenesulfonyl hydrazide), and paratoluenesulfonyl hydrazide; N, N'-dinitroso Nitroso compounds such as pentamethylenetetramine, N, N'-dinitroso-N, N'-dimethylterephthalamide, terephthalazide, p
-Azide compounds such as tertiary butyl benzazide; and inorganic compounds such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate, and at least one of them is used. Among them, azodicarbonamide and 4,4 ′
-Oxybis (benzenesulfonyl hydrazide) is 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.

Further, a foaming accelerator or a foaming aid can be used for the purpose of lowering the decomposition temperature of the thermal decomposition type foaming agent. Examples of the foaming accelerator or foaming assistant include zinc white, zinc nitrate, lead phthalate, lead carbonate, phosphate trichloride, inorganic salts such as tribasic lead sulfate, zinc fatty acid soap, lead fatty acid soap, and cadmium. Examples include metal soaps such as fatty acid soaps, borax, acids such as oxalic acid, succinic acid and adipic acid, urea, biurea, ethanolamine, glucose and glycerin.

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.

The thermal decomposition type foaming agent is usually added in an amount of 1 to 9 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the polyethylene resin powder.

In the present invention, a liquid coating agent can be used simultaneously with the above-mentioned pyrolytic foaming agent. The liquid coating agent used in the present invention is preferably a coating agent that cures at room temperature to 220 ° C. Specifically, thermosetting coating agents for protecting the surface of plastics such as polysiloxane, melamine, urethane, and fluorine-containing plastics, and polyester resins such as unsaturated polyester, alkyd, oil-free alkyd, and linear polyester resin , Melamine resin, amino resin such as modified melamine resin, novolak type,
Epoxy resins such as β-methyl epichloro type, cycloaliphatic type, acyclic aliphatic type, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, chlorinated type, resorcinol type, oil modified, moisture cured block Polyurethane resin such as one-pack type polyurethane resin, two-pack type of catalyst-cured polyol-cured polyurethane resin, organic solvent type,
Aqueous type, non-solvent type acrylic resin and methacrylic acid ester-based acrylic resin are exemplified. Among these liquid coating agents, polysiloxane, acyclic aliphatic type and cycloaliphatic type epoxy resin,
Solvent-free acrylic resins such as acrylic syrup are preferred, and among them, epoxy resins that cure at room temperature to 150 ° C. are particularly preferred.

The liquid coating agent is usually 50
Although those having a viscosity of about 50,000 cps 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. Examples of the curing agent for the epoxy resin include amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 2,4,6-tris (dimethylaminomethyl) phenol, and meta-xylylenediamine; phthalic anhydride; Examples thereof include acid anhydrides such as hydrophthalic acid, methylnadic anhydride, and 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. At least one peroxide can be used.

The liquid coating agent is used in an amount of usually 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the polyethylene resin powder. The curing agent used in combination with the liquid coating agent is liquid coating agent 1
Usually, 100 parts by weight or less is added to 00 parts by weight.

The production method of the present invention is an improved method of the powder molding method, that is, the fluid immersion method, the electrostatic coating method, the powder spraying method, the powder rotational molding method, and the powder slush molding method. An improved method is preferred, and the powder slush molding method refers to the molding method described in JP-A-58-132507.

That is, the production method of the present invention
(1) A container having an opening containing a required amount of a specific thermoplastic elastomer powder is fixed to a mold having an opening heated to a temperature sufficiently higher than the melting temperature of the powder by fixing the opening to the container. It is fixed to the hollow part inside the mold and integrated,
A step of rapidly supplying the powder from the container to each part in the mold with rotation and / or swinging, adhering and melting, and discharging excess powder into the container; and (2) then, for the polyethylene resin powder, A container having an opening containing a required amount of a pyrolytic foaming agent, or an expandable polyethylene resin powder composition obtained by blending a pyrolytic foaming agent and a liquid coating agent, to a temperature sufficiently higher than the melting temperature of the powder composition. The heated mold having the non-foamed layer obtained in the above step (1) and the opening are fixed together, or fixed to the hollow portion inside the mold and integrated, and rotated and / or swung together. A step of rapidly supplying the foamable polyethylene resin powder composition from the container to each part in the non-foamed layer, adhering and melting, and discharging the surplus powder composition into the container; and (3) the step Step of heating and foaming a more obtained compact, it is possible to provide a method for producing a composite foamed molded body, comprising the city.

Accordingly, the thermoplastic elastomer powder and the expandable polyethylene resin powder composition used in such a powder molding method have excellent powder flowability, and have a low shear rate at a low shear pressure mainly supplied from a mold. Must be easily melted.

The mold heating system used in the powder molding method according to the present invention is not particularly limited. For example, a gas heating furnace system, a heating medium oil circulation system, a heating medium oil or hot fluid sand can be used. Immersion method or high-frequency induction heating method and the like, when foaming the molten powder composition,
These heating sources can be used.

The molding temperature of the non-foamed layer of the present invention is usually 16
It is 0-300 degreeC, Preferably it is 180-280 degreeC. 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 from 180 to 2
80 ° C., preferably 160 to 250 ° C. The foaming time is not particularly limited, and is appropriately selected depending on the thickness of the foamed layer and the foaming ratio.

The method of blending the pyrolytic foaming agent or the pyrolytic foaming agent and the liquid coating agent with the polyethylene resin powder is not particularly limited.
For example, a method is preferred in which a pyrolytic foaming agent is previously blended with polyethylene resin powder, and then a liquid coating agent is blended with these compositions.

Further, when the molded product obtained by molding the powder with the thermoplastic elastomer powder composition used in the present invention is released from the mold, the inner surface of the mold is strongly adhered. May occur. Therefore, it may be necessary to coat the inner surface of the mold before molding by spraying a generally 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, a method of improving the mold material may be considered. However, a methylpolysiloxane compound is added to the elastomer powder composition as an internally added release agent in an amount of 2 parts by weight or less per 100 parts by weight of the elastomer powder composition. Is effective. In this case, the timing of addition may be before or after powdering. In this case, the methylpolysiloxane compound may have a viscosity at 25 ° C. of 20 centistokes or more. The preferred viscosity range is 50-50
00 centistokes. If the viscosity is too high, the effect as a release agent is reduced. On the other hand, when the amount of the internally added release agent is more than 2 parts by weight, heat fusion between the elastomer powders is hindered, and only a molded article having poor mechanical properties can be obtained. In addition, the internally added mold release agent bleeds on the mold surface, and the mold is undesirably contaminated.

In the present invention, known heat stabilizers such as phenol-based, sulfite-based, phenylalkane-based, phosphite-based, amine-based or amide-based stabilizers,
Antioxidants, weathering stabilizers, antistatic agents, lubricants such as metallic soaps and waxes, coloring pigments and the like can be added in necessary amounts.

[0043]

As described in detail above, the present invention comprises a thermoplastic elastomer powder capable of forming a molded article having a small residual strain and a complicated shape by a powder molding method. A composite foam molded article in which a non-foamed layer and a foamed layer made of polyethylene resin powder having a high foaming ratio and a large size, uniform cells, and a smooth surface can be easily manufactured.

Further, the present invention can provide a composite foam molded article excellent in light weight and cleanness. The composite foam molded article of the present invention is, for example, in the automotive field, instrument panel, console box, armrest, headrest, door trim, rear panel, pillar trim, sun visor, trunk room trim, trunk lid trim,
Airbag storage boxes, seat buckles, headliners, glove boxes, steering wheel covers, interior skin materials such as ceiling materials, kick plates, change lever boots, interior moldings such as ceiling materials, spoilers, side moldings, license plate housings, Suitable for car exterior parts such as mirror housing, air dam skirt, mudguard, etc.

Further, the composite foam molded article of the present invention is used in the fields of home electric appliances and office automation equipment, for example, for televisions, videos,
Washing machine, dryer, vacuum cleaner, cooler, air conditioner, remote control case, microwave oven, toaster, coffee maker, pot, jar, dishwasher, electric razor, hair dryer, microphone, headphone, beauty equipment, CD / cassette storage box Suitable for skin materials and housings of personal computers, typewriters, projectors, telephones, copiers, facsimile machines, telexes, etc.

In the field of sporting goods, the composite foam molded article of the present invention can be used, for example, for decorative parts for sports shoes,
Rackets for various ball games, grips for sports equipment and supplies,
Suitable for the saddle skin and handle grip of bicycles, motorcycles, and tricycles.

The composite foam molded article of the present invention can be used in the field of construction and housing, for example, in skin materials such as furniture, desks and chairs, gates,
Doors, fences and other skin materials, wall decoration materials, ceiling decoration materials, curtain wall skin materials, indoor flooring materials such as kitchens, washrooms, toilets, etc., outdoor flooring materials such as verandas, terraces, balconies and carports, and entrances Mats, tablecloths, coasters,
Suitable for rugs such as ashtrays.

The composite foam molded article of the present invention is suitable for, for example, grips of electric tools, hoses, skin materials thereof, and packing materials in the field of industrial products.

In addition to the above, the composite foam molded article of the present invention can be used for molding bags, cases, files, notebooks, albums, stationery, camera bodies, skin materials such as dolls and other toys, and watch bands and the like. Suitable for body, forehead frame and skin material.

[0050]

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 composite foam molded article, the thickness of the composite foam molded article, the state of the foam layer cell, and the expansion ratio of the foam layer in the examples and comparative examples were evaluated as follows. The appearance foam layer 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. XX: Almost no cells exist. Expansion ratio of foam layer The expansion ratio was calculated by the following equation. Foaming ratio = Density when not foaming / Density when foaming The density of the foamed layer is measured by a densitometer manufactured by Toyo Seiki Seisakusho (Dens
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.

Example 1 Mineral oil 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,
0.04 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxynohexane) was added, and the mixture was heated to 220 ° C. using a twin-screw kneader (registered trademark TEX # 44, manufactured by Nippon Steel Works).
Was performed to obtain elastomer composition pellets. After cooling the pellets to a temperature of −100 ° C. using liquid nitrogen, the pellets are frozen and pulverized to 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. This powder passed 99% by weight through a 32 mesh Tyler standard sieve.

A nickel plate mold (30 cm × 30 cm) with a flat grain 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 discharging the excess powder, low-density polyethylene resin powder (manufactured by Sumitomo Seika, Flowsen UF-80, MFR)
= 75 g / 10 min, average particle diameter 20-30 μm) 100 parts by weight of a thermal decomposition type blowing agent azodicarbonamide (manufactured by Sankyo Chemical Co., Cell Mike CAP-250, decomposition temperature 145)
° C) The foamable polyethylene resin powder composition prepared by mixing 3 parts by weight was sprinkled for 20 seconds, and excess powder composition was discharged. Further, this mold was placed in a gear oven at an ambient temperature of 200 ° 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 An azodicarbonamide (manufactured by Sankyo Kasei, CellMike CAP-50) was used instead of the pyrolytic foaming agent in Example 1.
0 and a decomposition temperature of 150 ° C.) in the same manner as in Example 1 except that 3 parts by weight were used. Table 1 shows the evaluation results of the composite foam molded article.

Example 3 In place of the low-density polyethylene resin powder in Example 1, another low-density polyethylene resin powder (Flosen UF-20, manufactured by Sumitomo Seika, MFR = 20 g / 10
A composite foam molded article was manufactured in the same manner as in Example 1 except that the average particle size was 20 to 30 μm). Table 1 shows the evaluation results of the composite foam molded article.

Example 4 Instead of the low-density polyethylene resin powder in Example 1, another low-density polyethylene resin powder (Flosen A-1003-N, manufactured by Sumitomo Seika, MFR = 75 g)
/ 10 min, average particle size of 50 ± 5 mesh) except that a composite foam molded article was produced in the same manner as in Example 1.
Table 1 shows the evaluation results of the composite foam molded article.

Comparative Example 1 Instead of the low-density polyethylene resin powder in Example 1, another low-density polyethylene resin powder (Flosen UF-1.5, manufactured by Sumitomo Seika, MFR = 1.5 g /
A composite foam molded article was produced in the same manner as in Example 1, except that the average particle size was 10 minutes, and the average particle diameter was 10 to 20 μm. Table 1 shows the evaluation results of the composite foam molded article.

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. A composite foam molded article was produced in the same manner as in Example 1 except that this powder was used. Table 1 shows the evaluation results of the composite foam molded article.

Example 6 3 parts by weight of the pyrolytic blowing agent in Example 5 was added to 5 parts by weight.
A composite foam molded article was produced in the same manner as in Example 5 except that the amount was changed to parts by weight. Table 1 shows the evaluation results of the composite foam molded article.

Example 7 A composite foam molded article was produced in the same manner as in Example 5 except that the addition amount of the pyrolytic foaming agent in Example 5 was changed to 7.5 parts by weight. Table 1 shows the evaluation results of the composite foam molded article.

Example 8 The same powder as in Example 5 was used as the thermoplastic elastomer powder for powder molding. A nickel plate mold with a grain (30 cm × 30 cm) was heated in a gear oven at 300 ° C. When the surface of the mold reached 250 ° C., a thermoplastic elastomer powder for powder molding was sprinkled for 5 seconds. Immediately after discharging the excess powder, a linear low-density polyethylene resin powder (Flosen F-1 manufactured by Sumitomo Seika Co., Ltd.)
3142-N, MFR = 10 g / 10 min, average particle size 80
Thermal decomposition foaming agent azodicarbonamide (manufactured by Sankyo Chemical Co., Ltd., Cermic C)
(AP-250, decomposition temperature: 145 ° C.) A foamable polyethylene resin powder composition prepared by mixing 3 parts by weight was sprinkled for 30 seconds, and excess powder composition was discharged. Further, this mold was placed in a gear oven at an ambient temperature of 200 ° C., and heated for 70 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 9 Instead of the polyethylene resin powder in Example 8, another linear low-density polyethylene resin powder (Flosen M-13152-N, manufactured by Sumitomo Seika, MFR = 4) was used.
g / 10 min, average particle size of 75 ± 10 mesh), and a composite foam molded article was produced in the same manner as in Example 8. Table 1 shows the evaluation results of the composite foam molded article.

Example 10 Instead of the polyethylene resin powder in Example 8, another polyethylene resin powder (Flosen F-15028, manufactured by Sumitomo Seika, MFR = 10 g / 10 min,
A composite foam molded article was produced in the same manner as in Example 8, except that the average particle size was 85 ± 10 mesh). Table 1 shows the evaluation results of the composite foam molded article.

Example 11 Instead of the polyethylene resin powder in Example 8, another low-density polyethylene resin powder (Flosen A-1003-N, manufactured by Sumitomo Seika, MFR = 75 g /
10 minutes, average particle size 50 ± 5 mesh)
A composite foam molded article was produced in the same manner as in Example 8. Table 1 shows the evaluation results of the composite foam molded article.

Example 12 A foamable polyethylene resin powder composition obtained in the same manner as in Example 11 was coated with 1 part by weight of a liquid coating agent (Sumitomo Chemical Co., Sumipec Cement 7, registered acrylic resin) and 20 ml of ethyl acetate. 2 drops of a curing liquid containing benzoyl peroxide as a main component, diluted with a 5 liter super mixer at 500 rpm for 2 minutes.
Mix for 3 minutes at 0 rpm. Hereinafter, a composite foam molded article was manufactured in the same manner as in Example 8. Table 1 shows the evaluation results of the composite foam molded article.

Example 13 A liquid coating agent (Sumiepoxy ELA115, manufactured by Sumitomo Chemical Co., Ltd., cycloaliphatic epoxy resin polymerized from epichlorohydrin and bisphenol A) was added to the foamable polyethylene resin powder composition obtained in the same manner as in Example 8. 0.5 parts by weight of triethylenetetramine and 0.05 parts by weight of triethylenetetramine were mixed and mixed in the same manner as in Example 8. Hereinafter, a composite foam molded article was manufactured in the same manner as in Example 8. Table 1 shows the evaluation results of the composite foam molded article.

Example 14 0.5 part by weight of the liquid coating agent in Example 13 was changed to 1 part by weight, and
A composite foam molded article was produced in the same manner as in Example 13 except that the weight part was changed to 0.1 part by weight. Table 1 shows the evaluation results of the composite foam molded article.

Example 15 0.5 part by weight of the liquid coating agent in Example 13 was changed to 3 parts by weight, and
A composite foam molded article was produced in the same manner as in Example 13 except that the weight part was changed to 0.3 part by weight. Table 1 shows the evaluation results of the composite foam molded article.

[0071]

Example 16 A white pigment (manufactured by Sumika Color Co., Ltd., White PV-74) was added to the same powder as the thermoplastic elastomer powder obtained in Example 4.
2) 1.0 part by weight was mixed and supplied to a super mixer having a capacity of 20 liters, and mixed at 500 rpm for 10 minutes to obtain 5050 g of a colored thermoplastic elastomer powder composition for powder molding (for a non-foamed layer).

Further, a pigment (0.7 parts by weight of White PV-742, manufactured by Sumika Color Co., Ltd.) was added to the same powder composition as the foamable low-density polyethylene resin powder composition obtained in Example 4.
1.0 part by weight of Black PV-817 (mixed with 0.3 part by weight of Black PV-817) to obtain 5150 g of an expandable polyethylene resin powder composition colored in gray.

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 polyethylene resin powder composition was supplied to the table. This square container is 600mm × 220
mm rectangular opening 1 with a depth of 210 mm,
It is attached to the 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
The powder supply box containing the foamable polyethylene resin powder composition was placed along with the opening 1 of the powder supply box, and the outer frames attached around both openings were brought into close contact with each other, fixed with the clip 2, and integrated. The surface temperature of the mold at this time was 19
3 ° C.

Immediately, the powder supply box containing the foamable polyethylene resin 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
20 g, thickness 0.7 mm, foam layer 120 g, thickness 3.6 mm, expansion ratio 3.5 times. 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.

[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 ... Wrinkle pattern part in a mold 6 ... Mold inner grain pattern part

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29L 31:58 C08L 23:08 31:04 (72) Inventor Tadashi Hikasa 5-1, Anesaki Kaigan, Ichihara City, Chiba Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Hiroaki Tsumori 5-1, Anesaki Beach, Ichihara City, Chiba Prefecture Within Sumitomo Chemical Co., Ltd. (56) References JP-A-1-253433 (JP, A) JP-A-1-123744 (JP, A) JP-A-64-29443 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 41/04 B32B 25/14 C08J 9/10

Claims (2)

(57) [Claims] 1. A composite foamed molded article in which a non-foamed layer and a foamed layer are integrated, wherein the non-foamed layer is a layer formed from the thermoplastic elastomer powder of the following (A), and the foamed layer is the following (B) )) To (C)
A composite foam molded article characterized in that it is a layer formed by blending and foaming a pyrolytic foaming agent or (C) a pyrolytic foaming agent and (D) a liquid coating agent. (A) A thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin copolymer rubber and a polyolefin resin, or a mixture of an ethylene / α-olefin copolymer rubber and a polyolefin resin as a crosslinking agent Is a thermoplastic elastomer powder composed of a partially crosslinked elastomer composition dynamically crosslinked in the presence of
Complex dynamic viscosity η ^* (1) measured in radians / second is 1.
5 × 10 ⁵ poise or less and frequency 1 radian /
The Newtonian viscosity index n calculated using the complex dynamic viscosity η ^* (1) in seconds and the complex dynamic viscosity η ^* (100) at a frequency of 100 radians / sec is 0.67 or less. Thermoplastic elastomer powder. n = {logη ^* (1) −logη ^* (100)} / 2 (B) A powder made of a polyethylene resin, JI
A polyethylene resin powder having an MFR (melt flow rate) of 3 g / 10 min or more measured by a method according to SK6760. 2. A method for producing a composite foamed molded article in which a non-foamed layer and a foamed layer are integrally molded by a powder molding method and heated, wherein a thermoplastic elastomer powder of the following (A) is used as the non-foamed layer: Foamable polyethylene resin composition powder obtained by blending (C) a pyrolytic foaming agent or (C) a pyrolytic foaming agent and (D) a liquid coating agent with the polyethylene resin powder of the following (B) as a foam layer. A method for producing a composite foam molded article, comprising: (A) A thermoplastic elastomer powder comprising an elastomer composition of an ethylene / α-olefin copolymer rubber and a polyolefin resin, or a mixture of an ethylene / α-olefin copolymer rubber and a polyolefin resin as a crosslinking agent Is a thermoplastic elastomer powder composed of a partially crosslinked elastomer composition dynamically crosslinked in the presence of
Complex dynamic viscosity η ^* (1) measured in radians / second is 1.
5 × 10 ⁵ poise or less and frequency 1 radian /
The Newtonian viscosity index n calculated using the complex dynamic viscosity η ^* (1) in seconds and the complex dynamic viscosity η ^* (100) at a frequency of 100 radians / sec is 0.67 or less. Thermoplastic elastomer powder. n = {logη ^* (1) −logη ^* (100)} / 2 (B) A powder made of a polyethylene resin, JI
A polyethylene resin powder having an MFR (melt flow rate) of 3 g / 10 min or more measured by a method according to SK6760.