JP2000301645A - Multilayer molded product and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a feel of a bottom arrival without impairing cushionability even by using a skin material having a foaming layer by using the material having an at least open cell type foaming layer and a closed cell type foaming layer and adhesively integrating so that the open cell type layer becomes a front surface side of a molded product. SOLUTION: A skin material 1 is obtained by laminating a skin layer 2, an open cell type foaming layer 3 and a closed cell type foaming layer 4 with an adhesive or heat fusion bonding. In this case, the layer 3 is laminated to the layer 2 side from the layer 4. The material 1 is obtained by adhesively integrating with a base material 7 made of a thermoplastic resin. As a result, a heat and a pressure of molten resin when molded are shut off by the layer 4. Thus, the heat and the pressure are scarcely applied to the layer 3 to prevent collapse of the layer 3, and the multilayer molded product having no feel of bottom arrival is obtained by the layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer molded product in which a skin material having a foam layer is bonded and integrated on a surface of a substrate made of a thermoplastic resin, and a method for producing the same.

[0002]

2. Description of the Related Art A multilayer molded product in which a skin material having a foam layer is bonded and integrated on the surface of a substrate made of a thermoplastic resin,
It is widely used in automobile interior parts (for example, door trims and instrument panels), interior and exterior parts of home appliances, and other wide fields.

Conventionally, as a method for producing such a multilayer molded article, for example, an adhesive material or the like is applied to a molded article (substrate) previously produced by various methods such as injection molding and injection press molding. A method of bonding and laminating using a method, and supplying a skin material between a pair of molds and then supplying a molten thermoplastic resin to form a desired shape and simultaneously bonding and integrating the skin material on the substrate surface. Methods are known.

However, in such a method, the former method has a complicated process and has a problem on the human body and the environment due to the solvent contained in the adhesive, and the latter method has a problem in forming a base material. At the same time, there is an advantage that the skin material can be bonded to the surface, but when the molten thermoplastic resin is supplied into the mold, the high-temperature, high-pressure molten resin comes into contact with the skin material, and the mold molding surface In addition, since the skin material is strongly pressed, there is a problem that the foam layer is crushed and the cushioning property is impaired, and the surface has irregularities.

[0005] To solve these problems, for example, an expansion ratio of 2
It has been proposed to use a skin material in which a high-density urethane foam is adhered to the back side of a skin sheet lined with a foam layer having a high expansion ratio such as 0 times or more polypropylene foam (Japanese Patent Laid-Open No. 3-262750). . According to this method, the heat of the molten resin at the time of molding is cut off by the high-density urethane foam. The high-density urethane foam layer is crushed by heat. For this reason, although a multilayer molded product having a soft feeling can be obtained, there is a problem that the cushioning property is impaired due to the collapse of the high-density urethane foam layer, resulting in a molded product having a feeling of bottom contact.

[0006]

SUMMARY OF THE INVENTION
The present inventors take advantage of the injection molding method and the injection press molding method that the surface material can be bonded to the surface at the same time as forming the base material, and even when using the skin material having a foamed layer, As a result of investigations to produce a multilayer molded product without impairing the cushioning property and without a feeling of bottom contact, the present invention was reached.

[0007]

That is, according to the present invention, a skin material is supplied between a pair of dies, and a molten thermoplastic resin is supplied between the skin material and a molding surface of one of the dies. In a method of manufacturing a multilayer molded product by bonding and integrating a skin material to at least a part of the surface of a substrate made of a thermoplastic resin, the method has at least an open-cell foam layer and a closed-cell foam layer. It is intended to provide a method for producing a multilayer molded product, which comprises using a skin material, and laminating and integrating the closed cell foam layer so that the foam layer side is the substrate side. A multilayer molded product in which a skin material is bonded and integrated to at least a part of the surface of a substrate made of a thermoplastic resin, wherein the skin material is at least an open-cell foam layer and a closed-cell foam layer. The foamed cell of the open-cell type has a molded product more than the foamed layer of the closed-cell type. It is to provide a novel multilayer molded article formed by laminating integrally so as to be positioned on the side.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a multilayer molded product of the present invention and a method for producing the same will be described.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The multilayer molded article of the present invention is a multilayer molded article in which a skin material is bonded and integrated on at least a part of the surface of a substrate made of a thermoplastic resin, and the skin material is at least an open-cell type. And a closed-cell type foam layer, and the open-cell type foam layer is bonded and integrated so as to be located closer to the surface of the molded product than the closed-cell type foam layer. Here, the skin material needs to have an open-cell foam layer and a closed-cell foam layer. However, even if the skin material is composed of only these two types of foam layers, The skin layer may be further laminated, or may be lined with a backing material. Further, the two types of foam layers may be directly laminated by fusion bonding or an adhesive, or may be laminated via another appropriate sheet or film. Further, these foam layers and the skin layer or The backing material may be directly laminated, or may be laminated via another appropriate sheet or film.

When the multilayer molded article of the present invention has a skin layer and / or a backing material, it is laminated so that an open-cell foam layer is on the skin layer side and a closed-cell foam layer is on the substrate side. It is necessary to be.

When the closed-cell type foam layer is located on the skin layer side (molded product surface side), the molten resin becomes the open-cell type foam layer side at the time of molding. The open-cell type foam layer is easily crushed and the feel is hard. Therefore, by arranging the open-cell foam layer on the skin layer side and the closed-cell foam layer on the base material side, the heat and pressure of the molten resin during molding can be reduced by the closed-cell foam layer. The open-cell foam layer is hard to apply heat and pressure to prevent collapse of the open-cell foam layer and has a soft touch. It is a multilayer molded product without any.

The open-cell foam layer may be any foam layer in which foam cells communicate with each other, such as a soft or semi-rigid polyurethane foam. In the present invention, urethane foam is used. Is particularly preferably applied. The density and thickness of the open-cell type foam layer are not particularly limited, but the density is 0.02 to 0.06.
g / cm @ 3 and a thickness of 1 mm or more are preferably used.

The closed-cell foam layer may be any foam layer in which foam cells are independent of each other, such as polypropylene foam and polyvinyl chloride foam. The density and thickness of the closed-cell foam layer are not particularly limited. For example, when the foam layer is a polypropylene foam, the expansion ratio is 20 times or less and the thickness is 1
mm or more is preferably used.

The skin layer may be a woven or knitted fabric such as a moquette or a tricot, a nonwoven fabric such as a needle punch carpet, a metal foil, a thermoplastic resin or a thermoplastic elastomer.
Sheet or film.

As the backing material, a sheet or film made of non-woven fabric or synthetic resin is used. Examples of the fibers constituting the nonwoven fabric include natural fibers such as cotton, wool, silk, and hemp, and synthetic fibers such as polyamide, polyester, and nylon. These are used alone or as a blend to form a nonwoven fabric by various methods. For example, non-woven fabrics of a needle punch type, a thermal bond type, a spun bond type, a melt blow type, a spun lace type and the like can be used. Examples of the sheet or film made of a synthetic resin include a sheet or a film made of a thermoplastic resin such as polypropylene or polyethylene and a polyolefin-based thermoplastic elastomer, and have a fusibility with the thermoplastic resin used as the base resin. Materials are used.

As the thermoplastic resin (9) applied to the present invention, any thermoplastic resin used for extrusion molding, injection molding, and press molding can be used. For example, polyethylene, polypropylene, General thermoplastic resins such as acrylonitrile-styrene-butadiene copolymer, polyamide such as polystyrene and nylon, polyvinyl chloride, polycarbonate, acrylic resin, styrene-butadiene block copolymer, and thermoplastic elastomers such as EPM and EPDM And a mixture thereof, or a polymer alloy using the same, and the like. These may be foamable or non-foamable.

Such a thermoplastic resin may contain, if necessary, reinforcing fibers such as glass fibers and other fillers such as various inorganic or organic fillers. Additives such as various pigments, lubricants, antistatic agents and stabilizers.

As a molding method for obtaining the multilayer molded article of the present invention, an appropriate method such as an injection molding method or a compression molding method is applied. In the case of the injection molding, a skin material is supplied when a molten thermoplastic resin is supplied. Since the heat and pressure of the molten resin are directly applied to the resin and the damage to the skin material may increase, open the mold when supplying the molten resin and tighten the mold after supplying the molten resin or simultaneously with the completion of the supply. A method by compression molding that can reduce damage to the skin material is preferable.

Hereinafter, a method for producing a multilayer molded product by injection press molding, which is a typical production method, will be described with reference to the drawings. This description is an example of the present invention,
It goes without saying that the present invention is not limited to this.

FIG. 1 is a sectional view showing an example of a skin material (1) applied to the present invention. The skin layer (2), the open-cell foam layer (3) and the closed-cell foam layer (3) are shown. 4) is laminated by an adhesive or heat fusion. As is apparent from this figure, it is important that the open-cell foam layer is stacked closer to the skin layer than the closed-cell foam layer.
FIG. 2 is a cross-sectional view showing an example of another skin material (1 ′) applied to the present invention. The backing layer (closed-cell foam layer side) of the skin material shown in FIG. 10 shows a skin material laminated with 10). FIGS. 3 and 4 show examples of a multilayer molded article of the present invention in which such a skin material is laminated and integrated with a base material (7) made of a thermoplastic resin.

FIG. 5 shows a pair of male and female (5,
6 shows a state in which the skin material (1) is supplied between the molds composed of 6). At the time of supply, the skin material may be merely placed on the mold forming surface of the male mold (5). However, as shown in the figure, the male or female mold (6) main body and, for example, the skin provided around these bodies are provided. It may be fixed to a material fixing frame (not shown) using a pin or the like. The skin material may be preheated or preformed according to the shape of the product.

FIG. 6 shows a state in which the skin material (1) supplied between the molds is melted between a mold forming surface (a male mold forming surface in the figure) on the closed cell foam layer side of the skin material. 3 shows a state in which a thermoplastic resin (7) is supplied. The method of supplying the molten resin may be a so-called internal supply method in which the molten resin is injected into the cavity from a molten resin passage provided in the male mold, or may be an external supply method which supplies the molten resin into the cavity from an appropriate supply device outside the mold. A supply method may be used, but an internal supply method is preferable in consideration of operability, cooling of the supplied molten resin, and the like.

FIG. 7 shows a state in which the male and female molds are clamped. In this mold clamping step, the thermoplastic resin is shaped into a base material, and at the same time, the skin material is bonded and integrated with the base material. Is done. Although the figure shows an example of the mold clamping in the vertical direction, the mold clamping direction may be the vertical direction or the horizontal direction. When the molten thermoplastic resin is supplied by the internal supply method, the mold clamping may be started after the supply of the molten resin, or simultaneously with the completion of the supply, or in parallel with the supply of the molten resin. Then, the mold clamping may be completed simultaneously with or after the completion of the supply of the molten resin.

When the mold clamping is completed, while maintaining this state, the molten resin is cooled and solidified, the mold is opened (FIG. 8), and the molded product is taken out. As shown in FIG. A multilayer molded product (8) in which a skin material is bonded and integrated on the surface of a substrate made of Here, an example in which the skin material is bonded and integrated over the entire surface of the base material has been described.
If a multi-layer molded product in which the skin material is bonded to a part of the surface of the base material as shown in the above is desired, the skin material is partially mold-molded so as to correspond to the skin material bonding position of the final molded product. It may be supplied in the middle and then molded in the same manner as above.

[0025]

According to the method of the present invention, a skin material having a foamed layer can be obtained while taking advantage of the injection molding method and the injection press molding method in which a skin material can be bonded to the surface of the substrate at the same time as forming the base material. Even when used, it is possible to produce a multilayer molded article without impairing the cushioning property and without a feeling of bottom contact.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a skin material applied to the present invention.

FIG. 2 is a cross-sectional view showing another example of the skin material applied to the present invention.

FIG. 3 shows an example of a multilayer molded product of the present invention in a cross section thereof.

FIG. 4 shows another example of the multilayer molded product of the present invention in a cross section.

FIG. 5 is a schematic cross-sectional view of a mold showing a manufacturing process according to the method of the present invention.

FIG. 6 is a schematic cross-sectional view of a mold showing a manufacturing process according to the method of the present invention.

FIG. 7 is a schematic cross-sectional view of a mold showing a manufacturing process according to the method of the present invention.

FIG. 8 is a schematic cross-sectional view of a mold showing a manufacturing process according to the method of the present invention.

FIG. 9 is a cross-sectional view of a multilayer molded product obtained by laminating and integrating a skin material obtained by the method of the present invention on the entire surface of a substrate.

FIG. 10 is a cross-sectional view of a multilayer molded product obtained by laminating a skin material obtained by the method of the present invention on a part of a base material.

[Explanation of symbols]

 1, 1 ': skin material 2: skin layer 3: open-cell foam layer 4: closed-cell foam layer 5: male 6: female 7: thermoplastic resin (base material) 8, 9: multilayer molded product 10 : Backing layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B29L 31:58 (72) Inventor Takeo Kitayama 2-10-1 Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Co., Ltd. In-house F-term (reference) 4F100 AK01A AK03 AK07 AK15 AK51C AK51E AL09 AR00B AR00C AR00D AR00E BA03 BA05 BA06 BA07 BA10A BA10C BA10E BA13 DG15 DJ02B DJ02D DJ03C DJ03E EC032 EH17 EH3 AAD12 AH16 AB18A33A33 A33A33 EB13 EF01 EF27 EL17

Claims (5)

[Claims] 1. A multi-layer molded product in which a skin material is bonded and integrated to at least a part of the surface of a substrate made of a thermoplastic resin, wherein the skin material is at least an open-cell foam layer and a closed-cell foam. A multilayer molded article characterized by being bonded and integrated such that the open-cell type foam layer is located closer to the surface of the molded article than the closed-cell type foam layer. 2. The multilayer molded article according to claim 1, wherein the open-cell foam layer is made of urethane foam. 3. A base material made of a thermoplastic resin by supplying a skin material between a pair of molds and supplying a molten thermoplastic resin between the skin material and a mold molding surface of one of the molds. In a method of manufacturing a multilayer molded product by laminating and integrating a skin material on at least a part of the surface of a surface material, a skin material having at least an open-cell foam layer and a closed-cell foam layer is used, and A method for producing a multilayer molded article, comprising laminating and integrating the cell-shaped foam layer so that the foam layer side is the substrate side. 4. After supplying the skin material between the unclosed molds,
Supplying a molten thermoplastic resin between the skin material and the mold forming surface of the closed cell foam layer side of the skin material, and closing the mold material to bond and integrate the skin material and the thermoplastic resin. The method for producing a multilayer molded product according to claim 3, wherein: 5. The method according to claim 3, wherein the open-cell foam layer is made of urethane foam.