JP3320548B2 - Method for producing foam laminate and foam molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to housings for automobile interiors, office automation equipment, home electric appliances, etc.
It is used as a molded article of stationery, sanitary goods, daily necessities, building materials for interiors, etc., and gives a good feeling even when touched by humans, and is a method of manufacturing a foam laminate and a foam molded article having excellent abrasion resistance with a hardly scratched surface. .

[0002]

2. Description of the Related Art Conventionally, as a laminate using a foam, for example, a polyolefin-based thermoplastic elastomer layer is extruded into a sheet and simultaneously fused to a cross-linked foam sheet as disclosed in Japanese Patent Publication No. 1-14023. Things are listed.

[0003] As a method of manufacturing a molded article using a laminated foam, Japanese Patent Application Laid-Open No. 1-95032 discloses a method in which an unexpanded expandable polyolefin sheet and a synthetic resin sheet are bonded together and heated to form a foam. Immediately after softening a conductive polyolefin sheet, vacuum forming and press forming are simultaneously performed.

[0004]

Problems to be Solved by the Invention
No. 23, it is necessary to produce a foam sheet in advance before laminating with the thermoplastic elastomer, by heat and pressure for heat-sealing the foam sheet and the thermoplastic elastomer There is a problem that the foam structure is easily crushed.

In the production method described in Japanese Patent Application Laid-Open No. 1-95032, since the sheet is held, the foaming efficiency is poor, and the synthetic resin sheet to be bonded to the foamable polyolefin sheet is made of thermoplastic elastomer, polyvinyl chloride. And the like are not used, so that good suede-like touch and scratch resistance cannot be obtained.

The present invention solves the above-mentioned conventional problems, does not require a foaming step before lamination, is hardly scratched on the surface, has a suede-like soft touch feeling on the surface, and has excellent flexibility. A method for producing a foam laminate that can be deep drawn,
It is another object of the present invention to provide a method for producing a foam molded article having a high foaming ratio and a soft touch with a suede-like surface.

[0007]

According to the first aspect of the present invention, there is provided a method for producing a foamed laminate, comprising: a surface layer comprising a thermoplastic urethane elastomer and elastic fine particles; a base layer comprising a thermoplastic resin; The sheet-like laminate in which the foaming resin layer composed of the foaming agent and the thermal decomposition type foaming agent is laminated in this order is heated to a decomposition temperature of the thermal decomposition type foaming agent or more to a biaxial stretching ratio of 2 to 20 times. extending enlargement while foamable resin layer
Either by foamed to an expansion ratio 10-fold to 50-fold, or, of the thermoplastic at a temperature close to the softening temperature of the urethane elastomer enlargement extending in draw ratio 2-20 times in one direction and then thermally decomposable foaming agent foaming a foamable resin layer is heated above the decomposition temperature
Extending with in the other direction is foamed magnification 10-fold to 50-fold
Is characterized in that extending extension to extension magnification 2-20 times.

According to a second aspect of the present invention, there is provided a method for producing a foamed molded article according to the present invention, comprising: a surface layer comprising a thermoplastic urethane elastomer and elastic fine particles; a substrate layer comprising a thermoplastic resin; a thermoplastic resin and a crosslinking agent; The sheet-like laminate in which the foamable resin layer made of the foaming agent is laminated in this order is heated to a temperature not lower than the decomposition temperature of the pyrolytic foaming agent and is extended in the biaxial direction .
Foaming magnification of the foamed resin layer while enlargement extending in Shin magnification 2-20 times
The first step of foamed the rate 10-fold to 50-fold, and the resulting foam laminate, a surface layer was fed toward the mold side, and is characterized in that the molding by thermoforming .

The thermoplastic urethane elastomer constituting the surface layer according to the present invention has rubber elasticity at normal temperature, is plasticized at high temperature, and can be subjected to various molding processes.
Generally, as a rubber component (soft segment) having entropy elasticity in the molecule, polyether polyester,
Polycarbonate has a segment composed of urethane bonds as a molecular constraint component (hard segment) for preventing plastic deformation. As long as it can be molded, it may have a partially crosslinked structure in the molecule, but does not have a wide-range three-dimensional stitch structure.

The thermoplastic urethane elastomer has rubber elasticity at room temperature in order to exhibit abrasion resistance and excellent touch, and particularly has a glass transition point of -50.
Those having a temperature range of -20 ° C are preferred. When the glass transition point is −50 ° C. or less, the strength is insufficient.
If the temperature exceeds 20 ° C., the material becomes hard and the feel becomes poor.

If the average molecular weight of the thermoplastic urethane elastomer is too low, the rigidity of the sheet is reduced, and if it is too high, the flexibility of the sheet is impaired. Therefore, the weight average molecular weight is in the range of 20,000 to 3,000,000. Is preferred.

The hardness of the surface layer varies depending on the hardness and thickness of the base material layer and the foam layer laminated on the back surface.
Those having an A hardness of about 50 to 98 are preferred.

As the above-mentioned thermoplastic urethane elastomer, for example, a product name “UFINE PN3” manufactured by Asahi Glass Co., Ltd.
429 ", trade name" Milactran E990P "manufactured by Nippon Milactran Co., Ltd., trade name" T7 "manufactured by Dainippon Ink and Chemicals, Inc.
890 "and the like.

Further, elastic fine particles are added to the surface layer. Due to these elastic fine particles, fine irregularities are formed on the surface, and the surface becomes matte, and the touch is very soft and soft touch. The above-mentioned elastic fine particles have a property of recovering the shape by elasticity when the pressure is released after pressing until the shape is deformed, for example, polyurethane,
Acrylic resin (preferably acrylic-urethane resin),
Examples thereof include those made of polystyrene and styrene-isoprene copolymer, and such organic elastic fine particles are usually used.

The shape of the elastic fine particles is not limited to a spherical shape, and non-spherical materials obtained by means such as freeze-pulverization can also be used, and those having a maximum particle size distribution in the range of 1 to 100 μm are preferred. If the particle size is smaller than 1 μm, the surface irregularities are too small, so that the obtained sheet does not have a sufficient suede feeling (soft touch feeling). If the particle size exceeds 100 μm, the surface of the sheet is stretched when the sheet is stretched. Cracks easily occur in

On the other hand, if the amount of the elastic fine particles is less than 30 parts by weight, the unevenness of the sheet surface is poor and a suede feeling cannot be sufficiently obtained, and if the amount exceeds 150 parts by weight, the surface is cracked when the sheet is stretched. Is more likely to occur. Therefore, the addition amount is preferably 30 to 150 parts by weight based on 100 parts by weight of the resin.

The above-mentioned elastic fine particles are not limited to one kind, and two or more kinds may be used in combination. When a flexible thermoplastic urethane elastomer is used or the sheet-like laminate surface may have a slightly hard feel, for example, hard beads made of an inorganic material such as cross-linked polymethyl methacrylate or silica gel are mixed with the elastic fine particles. May be.

Although the thickness of the surface made of the thermoplastic urethane elastomer varies depending on the thickness constitution of each layer, it is generally preferably 5 to 100 μm in consideration of the abrasion resistance, the feel and the like of the obtained foamed laminate and foamed molded article.

Examples of the resin constituting the base layer include thermoplastic elastomer, polystyrene, acrylic polymer, polycarbonate, polyvinyl chloride, polyethylene, polypropylene, acrylonitrile-butadiene-styrene copolymer (ABS), modified polyphenylene oxide,
Examples thereof include thermoplastic resins such as polyphenylene sulfide, polyetherimide, polyetheretherketone, and ionomer. However, it is preferable to use a thermoplastic elastomer in order to provide a more flexible soft touch feeling.

Examples of the thermoplastic elastomer include urethane-based, styrene-based, and vinyl chloride-based polyesters used in the above-mentioned surface layer. For example, a polyolefin-based thermoplastic elastomer excellent in moldability and cost is used as a hard segment. Those having polypropylene and having an ethylene-propylene-methylene bond (EPM) having ethylene as a soft segment and an ethylene-propylene-diene methylene bond (EPDM) having a small amount of a diene component together with ethylene, and a mixture thereof; Further, there may be mentioned those which are partially crosslinked by adding an organic peroxide thereto.

In order to improve the stretch formability of the substrate layer, a thermoplastic elastomer may be mixed with a polyolefin resin such as polypropylene or linear low density polyethylene (LLDPE). The hardness of a thermoplastic elastomer depends on the feel to be obtained, but is generally JIS
Those having an A hardness of 50 to 98 are preferred.

The thickness of the base layer varies depending on the thickness constitution of the other layers to be laminated thereon. However, in consideration of the moldability of the foam laminate and the feel of the foam laminate and foam molded article obtained,
Generally, 200 to 3000 μm is preferable.

The foamable resin layer comprises a composition containing a foamable thermoplastic resin, a pyrolytic foaming agent having a decomposition temperature equal to or higher than the melting point of the foamable resin, and a crosslinking agent. Examples of foamable thermoplastic resins include polypropylene, polyolefin resins such as polyethylene, polystyrene, and styrene.
Polystyrene resins such as maleic anhydride copolymers, polyurethane resins such as polyurethane and polyether urethane, polyvinyl chloride resins such as soft polyvinyl chloride, A
Examples of the resin include a BS resin, various thermoplastic elastomers, and a mixture thereof. It is preferable that the resin contains the same type of resin as the base material layer in consideration of adhesion to the base material layer.

The thermal decomposition type foaming agent is not particularly limited as long as its decomposition temperature is equal to or higher than the melting point of the thermoplastic resin constituting the foamable resin layer. Are preferred, for example, azodicarbonamide, dinitrosopentamethylenetetramine, trihydrazinotriazine, barium azodicarboxylate, azobisisobutyronitrile, hydradicarbonamide, isopropyl hydradicarboxylate, p-toluene Sulfonyl hydrazide,
p, p'-oxybis (benzenesulfonylhydrazide) and the like.

In particular, azodicarbonamide, dinitrosopentamethylenetetramine, trihydrazinotriazine, etc., which generate a large amount of gas, are preferable. The decomposition temperature and the amount of generated gas of these foaming agents are dizodicarbonamide and dinitrosopentamethylenetetramine tetramine. About 200 ° C, about 250
ml / g, trihydrazinotriazine at about 235 ° C., about 240 ml / g. Alternatively, a pelletized master batch containing a foaming agent at a high density in advance can be used.

If the amount of the thermal decomposition type foaming agent is too large, the foam may be broken and uniform air bubbles may not be formed. If the amount is too small, the foam may not be foamed. 25 parts by weight are preferred.

In the case where the foamable thermoplastic resin, for example, a crystalline polymer, has a melt viscosity remarkably reduced when it exceeds the melting point, it is difficult to control the size and expansion ratio of bubbles by foaming. In such a case, in order to control the melt viscosity during foaming, it is preferable to partially crosslink as necessary.

The crosslinking agent used for crosslinking is not particularly limited. For example, it may be used in a molecule such as an oxime compound such as allyl acrylate, triallyl cyanurate or ethylene glycol dimethacrylate, a nitroso compound such as nitrophenol, or a vinyl monomer such as divinylbenzene. Examples include a polyfunctional monomer having at least one double bond.

If the amount of the crosslinking agent is too large, the melt viscosity of the resin becomes high and foaming may not occur. On the other hand, if the amount is small, bubbles may be broken and the foaming ratio may be reduced. 0.1 to 5 parts by weight with respect to

As a crosslinking method, there are radiation crosslinking by an electron beam and chemical crosslinking by a catalyst such as an organic peroxide. The organic peroxide used for chemical crosslinking is not particularly limited as long as it has a decomposition temperature higher than the melting point of the thermoplastic resin. Examples thereof include dicumyl peroxide, t-butylcumyl peroxide, and 2,5-dimethyl. -2,5 (t-butylperoxy) hexane, 1,8-bis (t-butylperoxyisopropyl) benzene, 1,1'-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, etc. Organic peroxides and organic peroxide esters are used.

The organic peroxide is generally a thermoplastic resin 10
0.01 to 3 parts by weight is added to 0 parts by weight.

The foamable resin layer is heated to a temperature not lower than the decomposition temperature of the foaming agent at the time of sheet molding and foams. If the foaming ratio at this time is 10 times or less, sufficient cushioning properties can be imparted. And the feel of the resulting foamed article is reduced. Further, it decreases the strength of more than 50 times the foamed resin layer, 1 being easily crushed broken or bubbles during stretching
It is limited to more than 0 times to 50 times.

The thickness of the foamable resin layer varies depending on the target thickness after foaming and the foaming ratio. However, in consideration of the abrasion resistance, feel, moldability and the like of the obtained foamed laminate, it is generally 50 to 2000 μm. preferable.

When the adhesion between the surface layer and the base material layer or between the base material layer and the foamable resin layer is poor, it is preferable to provide an adhesive layer between the respective layers. The resin used for the adhesive layer is a main chain such as an acid-modified styrene-butadiene-styrene copolymer, an acid-modified styrene-ethylene-styrene copolymer, an acid-modified polyethylene, and an acid-modified polypropylene. Alternatively, an adhesive polymer having a functional group such as a hydroxyl group, an amide group, an epoxy group, a carboxylic acid group, or a carboxylic acid ester group in a side chain may be used.

For example, when a polyolefin-based thermoplastic elastomer is used for the base material layer, a chlorinated polyolefin, an ionomer resin (ethylene methacrylic acid copolymer metal salt), an acid-modified SBS (styrene-ethylene-butadiene- Styrene copolymer) and the like, and in particular, those which themselves exhibit properties as an elastomer (JIS A hardness of about 50 to 80) are preferable. Adhesion can also be improved by using a material constituting the base material layer which has been modified by acid or graft beforehand, or by mixing them.

The thickness of the adhesive layer varies depending on the thickness of each layer, but is generally preferably 5 to 50 μm in consideration of the abrasion resistance, feel, moldability and the like of the obtained foamed molded article.

The above-mentioned surface layer, base material layer and foamable resin layer include:
If necessary, a colorant such as a pigment or a dye, an antioxidant, an ultraviolet absorber, or a light stabilizer such as a hindered amine may be added as long as the physical properties are not impaired.

As the coloring agent, pigments and dyes used as paints can be used. Titanium oxide as a pigment,
Dyes include iron oxide, carbon black, cyanine dyes, quinacridone dyes, and the like, and examples of dyes include azo dyes, anthraquinone dyes, indigoid dyes, and stilbenzene dyes. Further, metal powder such as aluminum flake, nickel powder, gold powder, silver powder and the like may be used as the coloring agent.

The amount of the coloring agent to be added varies depending on the application. However, when a coloring agent having a high concealing property is used, it is generally preferable that the amount is in the range of 2 to 400 parts by weight based on 100 parts by weight of the solid content of the resin. However, when the solid colorant of the pigment or metal powder is added to the surface layer, the soft touch feeling to be exhibited may be different depending on the initially set amount of the elastic fine particles. Therefore, the blending amount of the elastic fine particles with respect to the thermoplastic elastomer is slightly changed. There is a need.

The means for producing the sheet-like laminate used in the method for producing a foam laminate of the present invention is not particularly limited, but a co-extrusion molding method which does not require a plurality of steps and has excellent adhesion to each layer is preferred. An example of a method for producing a sheet-like laminate will be described below. Coextrusion molding is a method in which two or more extruders are used, and extruded resins are combined in a layered state to produce a product having a laminated structure. Such coextrusion molding includes a multi-manifold method, a multi-throttle method, a feed block method and the like.

The multi-manifold method is a method in which a plurality of manifolds are provided in a die and the respective layers are stacked in the die. This is a method of laminating each layer immediately after leaving the die, and the feed block method is a method of laminating and laminating each layer with a special block attached just before entering the die.

On the other hand, there is also a method of extruding a sheet from a separate extruder immediately before the extruded sheet or sheet-like laminate passes through a roll, and pressing and integrating these with a roll. The method for producing a foamed laminate of the present invention includes three layers, a surface layer, a base material layer, and a foamable resin layer, and, if necessary, an adhesion between each layer in order to increase the thickness accuracy of each layer and improve the adhesion between the layers. It is preferable to extrude the agent layers separately with each extruder to form a laminate.

When two or more materials are mixed and extruded, such as a surface layer and a foamable resin layer, the mixture may be extruded while being melt-kneaded by a twin-screw extruder or may be extruded. In the case of a co-extrusion apparatus not provided with the above, kneading in advance using a Banbury mixer or the like, and pelletizing using a pelletizer or the like may be extruded using a single screw extruder.

In the method for producing a foam laminate according to the first aspect of the present invention, the sheet laminate obtained as described above is
The foamable resin layer may be foamed while being heated at a temperature equal to or higher than the decomposition temperature of the pyrolytic foaming agent and simultaneously stretched in the vertical and horizontal directions, or the sheet laminate may be heated to a temperature close to the softening temperature of the thermoplastic elastomer. Stretching in the vertical or horizontal direction, and then stretching in the direction perpendicular to the stretching direction while heating the foamable resin layer by heating it to a decomposition temperature or higher of the pyrolytic foaming agent or more. The steps may be performed separately.

Here, the stretching ratio in the biaxial direction is 2 to
Limited to 20 times. If the stretching ratio is less than 2 times, only a foaming ratio of about 10 times can be obtained, and if it exceeds 20 times, it depends on the film thickness configuration before stretching and foaming. There is a possibility that the air bubbles may be cut, the air bubbles may be broken, or the air bubble state may be non-uniform.

According to a second aspect of the present invention, there is provided a tenter capable of biaxially stretching the sheet-like laminate obtained as described above by heating it to a temperature not lower than the decomposition temperature of the pyrolytic foaming agent. The first step of performing a cross-linking of the foamable resin layer while expanding in the biaxial direction using a stretching machine, foaming, and matting the surface layer to obtain a foamed laminate, and the obtained foamed laminate, The surface layer is supplied toward the mold side and is formed by thermoforming.

Here, thermoforming refers to vacuum forming or pressure forming (stamping forming). In the thermoforming, a male mold or a female mold may be used as a mold. When a female mold is used, if a grain pattern is formed on the surface of the mold, the grain pattern is transferred to the sheet surface simultaneously with the molding. Further, when the drawing at the time of forming is deep, a method of using a plug at the time of thermoforming (plug assist) or match molding may be performed.

Further, the above-mentioned foamed laminate may be laminated by introducing a molding resin as a molded article main body into a mold so that the surface layer of the foamed molded article overlaps the surface of the molded article. As a method of introducing the molding resin, the molding resin is introduced into the mold, then the stamping molding is performed by closing the mold, or the injection is performed by introducing the molding resin after the mold is closed. Molding and the like.

The molding resin is not particularly limited. For example, thermoplastic elastomers such as the above-mentioned thermoplastic polyurethane-based elastomer, thermoplastic polyolefin-based elastomer, thermoplastic polyester-based elastomer, ABS resin, polyethylene, polypropylene, and poly-ethylene. Examples include vinyl chloride, polystyrene, polycarbonate, acrylic resin, polyetherimide, polyphenylene sulfide, nylon, and the like, and those containing an inorganic filler such as glass fiber or silica.

When the resin forming the molded article is the same as the thermoplastic resin forming the foamable resin layer,
This is preferable because the adhesion between the foamable resin layer and the molding resin is improved. When the adhesiveness between the foamed molded article and the molding resin is poor, it is preferable to provide a primer layer such as chlorinated polypropylene on the product layer of the foamed molded article.

The obtained foam molded article may be laminated on another core material via an adhesive or the like. The core material is generally AB
S (acrylonitrile-butadiene-styrene copolymer), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, acrylic resin,
Examples include polyetherimide, polyphenylene sulfide, nylon, thermoplastic elastomers, and those containing glass fibers and inorganic fillers.
Further, a material obtained by previously laminating the same material as the above-mentioned core material on the foamable resin layer of the foam laminate may be used.

[0052]

In the method for producing a foamed laminate according to the first aspect of the present invention, a laminate obtained by laminating an unfoamed foamable resin layer on the surface of a base material layer is foamed and stretched biaxially. Since the step of laminating the resin layers is not performed, the foamed structure is not crushed by the roll pressure applied during lamination. Further, the stretching increases the strength of the foam laminate, and makes it flexible and capable of deep drawing. Furthermore, scratch resistance and flexibility are imparted by the thermoplastic urethane elastomer of the surface layer, and fine irregularities are formed on the surface by the elastic fine particles contained in the surface layer, resulting in a matte state, and a visual touch. Also, a material having an excellent suede-like soft touch feeling can be obtained.

In the method for producing a foamed molded article according to the second aspect, in addition to the same effect as the first aspect, the surface layer is molded toward the mold side, so that the expansion ratio is high, the flexibility and the scratch resistance are improved. A molded article having excellent softness and a suede-like soft touch feeling can be obtained.

[0054]

Embodiments of the present invention will be described below. Resin used Surface layer: thermoplastic urethane elastomer resin (manufactured by Asahi Glass Industry Co., Ltd., trade name: Ufine PN3429, JIS)
A hardness 85) 100 parts by weight Elastic fine particles (urethane beads manufactured by Sekisui Chemical Co., Ltd., trade name: Techno Polymer UB20, average particle diameter 20 μm) 70
Parts by weight The above components were kneaded with a Banbury mixer and pelletized. Adhesive layer: modified polyolefin (Mitsui Petrochemical Co., Ltd.
Product name: Admer QF551) Base layer: Thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., trade name: Mirastomer 8080N) 5
0 parts by weight Thermoplastic olefin elastomer resin (manufactured by Mitsui Petrochemical Co., Ltd., trade name: Mirastomer 5030N) 30 parts by weight Linear low-density polyethylene (manufactured by Mitsui Petrochemical Co., Ltd., trade name: ULTZEXUZ2021L) 10 parts by weight Polypropylene ( 10 parts by weight of Mitsui Petrochemical Co., Ltd., trade name: Hypol F650) A mixture of the above respective pellets was used. Foamable resin layer A: Polypropylene (ME manufactured by Tokuyama Soda Co., Ltd.
440) 60 parts by weight Linear low-density polyethylene 40 parts by weight Azodicarbonamide 10 parts by weight t-butylcumyl peroxide 1 part by weight The above mixture was kneaded with a Banbury mixer and pelletized. Foamable resin layer B: Polypropylene (ME manufactured by Tokuyama Soda Co., Ltd.
440) 60 parts by weight Linear low-density polyethylene 40 parts by weight Azodicarbonamide 15 parts by weight t-butylcumyl peroxide 1 part by weight The above mixture was kneaded with a Banbury mixer and pelletized. Foamable resin layer C: polypropylene (ME manufactured by Tokuyama Soda Co., Ltd.
440) 60 parts by weight Linear low-density polyethylene 40 parts by weight Azodicarbonamide 5 parts by weight t-butylcumyl peroxide 1 part by weight The above mixture was kneaded with a Banbury mixer and pelletized.

Production of Sheet Laminate Co-extrusion of four layers with a feed block type extrusion die (manufactured by Krollen) and an extruder (manufactured by Plastic Engineering Laboratory) having a diameter of 30Φ, 30Φ, 40Φ, and 40Φ. The temperature of each resin was set to 200 ° C., 190 ° C., 200
Extrusion and lamination at 160 ° C and 160 ° C.

Production of Foamed Laminate The stretching apparatus used in the method for producing the foamed laminate and the foamed molded article of the present invention comprises: a stretching roll for sequentially stretching in the longitudinal direction by a heating roll for stretching and a group of tension rolls; A lateral stretching tenter that travels on guide rails arranged in a lateral stretching pattern while holding both ends with clips, and a heat treatment oven capable of heating and air cooling is arranged longitudinally and laterally sequentially. This is an axial stretching device, which is adjacent to a co-extrusion device for producing the sheet-like laminate.

Example 1 A sheet-like laminate extruded and laminated by the above-mentioned co-extrusion apparatus was heated at a temperature close to the softening temperature of the thermoplastic elastomer used therein, and was heated at a higher speed than the discharge speed of the sheet-like laminate. The film was taken up by a take-up roll of a vertical stretching machine rotating at, and stretched in the longitudinal direction at a stretch ratio of 2.7 times.

Further, both ends of the vertically stretched sheet-like laminate are held by clips, and in the preheating zone, the temperature is raised to 230 ° C. (foaming agent azodicarbonamide for the foaming resin layer) at a suitable foaming temperature, and the foaming property is increased. Crosslink the resin layer. In the stretching zone, the foaming resin layer was foamed and stretched in the transverse direction at a stretching ratio of 2.7 times while maintaining the appropriate foaming temperature of 230 ° C.

After passing the heat treatment zone and the annealing zone, while holding the sheet with the clip, the surface layer side is cooled to a temperature close to the softening temperature of the thermoplastic urethane elastomer of the surface layer, and the clip is opened at the tenter outlet. The surface layer is matted by using an embossing take-off roll whose surface has been roughened by taking over with a take-off roll, and embossing having irregularities such as leather grain on the surface of the sheet-like laminate. To obtain a foamed laminate.

(Example 2) A sheet-like laminate was co-extruded with a feed block die holding the above three layers of the surface layer, the adhesive layer and the base material layer at 200 ° C.
A foamed laminate was obtained in the same manner as in Example 1 except that the laminate was extruded with a T-die held in the above-mentioned manner and heat-sealed and laminated on the three base material layer sides.

Example 3 The same procedure as in Example 1 was carried out except that the foamable resin layer was stretched so that the longitudinal and transverse stretch ratios were 3.1 times each using the composition of B. A foam laminate was obtained.

Example 4 A foamed laminate was produced in the same manner as in Example 3 except that a foamed resin layer having a composition of B was used to produce a sheet-like laminate in the same manner as in Example 2. Obtained.

(Comparative Example 1) Only the above-mentioned base material layer was extruded with a feed block die maintained at 200 ° C, and instead of the foamable resin layer A, a foam sheet (manufactured by Sekisui Chemical Co., Ltd., trade name:
A foamed laminate was obtained in the same manner as in Example 1, except that a softlon, a thickness of 2 mm, and an expansion ratio of 20 times) were heat-sealed and laminated on the base layer side.

(Comparative Example 2) The base material layer and the foamable resin layer C
Using the two layers described above, a sheet-like laminate was produced in the same manner as in Example 1, and both ends were retained and without stretching.
The foamable resin layer C was foamed in an oven at 30 ° C. to obtain a foamed laminate.

(Comparative Example 3) A foam laminate was obtained in the same manner as in Comparative Example 2 except that B was used for the foamable resin layer.

Comparative Example 4 Comparative Example 2 was repeated except that the above-mentioned four layers of the surface layer, the adhesive layer, the base material layer, and the foamable resin layer C were laminated.
In the same manner as in the above, a foam laminate was obtained.

The approximate thickness of each layer of the sheet-like laminate obtained in Examples 1 to 4 and Comparative Examples 1 to 4 and the stretched and expanded foam laminate, the appearance of the foam laminate, and the degree of matting (gloss) Table 1 shows the scratch resistance, the expansion ratio, and the cell shape. The appearance was visually observed for tearing or deformation of the sheet due to stretching or foaming. Matting degree is 60 degree mirror gloss 2.
A sample having a value of 0 or less was evaluated as ○, and a sample exceeding 2.0 was evaluated as ×. The expansion ratio is determined by cutting off three layers of a surface layer, an adhesive layer and a base material layer, measuring the specific gravity of the foamed layer using an electronic hydrometer (trade name: ED-120T, manufactured by Mirage Co., Ltd.), and determining the average density of the raw material. Was calculated. In addition, the cross-section of the foamed cells was observed by enlarging the section with a microscope, and the cell diameter and the appearance of the closed cells were evaluated.

[0068]

[Table 1]

The apparatus used in the method for manufacturing a foamed molded product according to claim 2 is a tenter stretching machine capable of simultaneous vertical and horizontal stretching, wherein the concave portion of a molding die having a mold surface having a concave portion is provided. A vacuum forming mold having a deaeration port for deaeration of the inside, and heaters arranged above and below a stretching machine.

The same sheet-like laminates as those used in Examples 1 to 4 and Comparative Examples 1 to 4 were held on the clips of the tenter stretching machine such that the surface layer side was the concave portion (surface) side of the mold. Then, the foamable resin layer was heated with a heater until the temperature reached the thermal decomposition temperature of the foaming agent, and the foamable resin layer was crosslinked and foamed while being simultaneously stretched to a predetermined stretching ratio in the vertical and horizontal directions to obtain a foamed laminate. The temperature of the heater at this time was 300 ° C. on the foamable resin layer side and 200 ° C. on the surface layer side,
The surface temperature of the foamed resin layer is about 230 ° C, and the surface layer side is about 14
It was 0 ° C. Subsequently, the heater was moved, and the foam laminate was fixed on a mold, followed by vacuum molding to obtain a foam molded article.

The appearance of the foamed molded article was observed, and the matting degree, scratch resistance and expansion ratio were measured. The results are shown in Table 2.

[0072]

[Table 2]

As is clear from Tables 1 and 2, Examples 1 to 4 have the constituent features described in Claims 1 and 2, so that the obtained foamed laminate and foamed molded article are Both the observation results and the measurement results achieved the object of the present invention. On the other hand, since the foamed laminates of Comparative Examples 1 to 4 are not stretched in the foaming process, they foam only in the thickness direction of the sheet. For this reason, when the expansion ratio exceeds 10 times, the bubbles are broken, and a high-magnification product cannot be obtained. When this is vacuum-formed, the bubbles are more severely broken.

[0074]

The method for producing a foam laminate and a foam molded article according to the present invention has the above-mentioned constitution. According to the method for producing a foam laminate according to claim 1, an unfoamed foamable resin layer is formed on the surface of the base material layer. Since the laminated product is foamed and stretched in the biaxial direction, the step of laminating the previously foamed resin layer is unnecessary,
The foamed structure does not collapse due to the roll pressure applied during lamination. Further, the strength of the foam laminate is increased, and the foam laminate is flexible and can be deep-drawn. Furthermore, the surface layer is provided with abrasion resistance and flexibility, and the surface is formed into a matte state by forming fine irregularities on the surface, and has a suede-like excellent soft touch feeling both visually and tactilely. Things are obtained.

According to the method for producing a foamed molded article according to the second aspect, in addition to the same effect as the first aspect, the surface layer is molded toward the mold side, so that the surface can be visually and feelably. A foam molded article excellent in suede tone can be obtained.

Furthermore, according to the first aspect of the invention, stretching and foaming can be performed simultaneously, and according to the second aspect of the invention, stretching and foaming can be performed followed by molding.
The number of manufacturing steps is small, the manufacturing can be performed efficiently, and the heat energy required for the manufacturing can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 44/00-44/60 B29C 67/20

Claims (2)

(57) [Claims] 1. A surface layer comprising a thermoplastic urethane elastomer and elastic fine particles, a substrate layer comprising a thermoplastic resin,
A sheet-like laminate in which a foamable resin layer made of a thermoplastic resin and a crosslinking agent and a pyrolytic foaming agent is laminated in this order,
Heated above the decomposition temperature of the pyrolytic foaming agent and extended in two axial directions
Foaming magnification of the foamed resin layer while enlargement extending in Shin magnification 2-20 times
Either by foamed the rate 10-fold to 50-fold, or, in one direction at a temperature close to the softening temperature of the thermoplastic urethane elastomer
The draw ratio 2-20 times enlargement extending, then the expansion ratio 10 foamable resin layer is heated to a temperature higher than the decomposition temperature of the thermally decomposable foaming agent
Stretching magnification Ultra 50 fold with is foamed in the other direction magnification 2
Method for producing a foam laminate, characterized by extending extension to 20-fold. 2. A surface layer comprising a thermoplastic urethane elastomer and elastic fine particles, a substrate layer comprising a thermoplastic resin,
A sheet-like laminate in which a foamable resin layer made of a thermoplastic resin and a crosslinking agent and a pyrolytic foaming agent is laminated in this order,
Foamable resin layer while enlargement extending in draw ratio 2-20 times biaxially with heating above the decomposition temperature of the thermally decomposable foaming agent
The first step of expansion ratio 10-fold to 50-fold foamed to, and the resulting foam laminate, a surface layer was fed toward the mold side, characterized by molding by thermoforming foam A method for producing a molded article.