JPH04331137A - Laminated product and method for forming the same - Google Patents

Abstract

PURPOSE:To provide a laminated product 7 having excellent adhesive strength with an air-permeable decorative skin 5 and a molding method thereof by using sheet-shaped molding blank 1 manufactured through a paper making method. CONSTITUTION:A laminated product 7 is manufactured in such a manner that a 5-30vol.% inorganic filler-contained thermoplastic resin 10 is interposed between an air-permeable decorative skin 5 and a core section in a fiber-reinforced thermoplastic resin layer 9 the core section of which is composed of not less than 15vol.% reinforcing fiber content through a paper making method, and heated, pressed and molded. Accordingly, adhesive strength is improved by an anchor effect by the intrusion of a thermoplastic resin in the inorganic filler- contained thermoplastic resin layer 10 as an intermediate layer into the air- permeable decorative skin 5 at the time of pressure molding, solidification and bonding.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate molded product comprising a fiber-reinforced thermoplastic resin core and a breathable decorative skin, and a method for molding the same. The laminate molded product according to the present invention is widely used as interior materials for automobiles, housing parts for home appliances, etc., and industrial parts such as furniture.

0002

[Prior Art] Recently, there has been a trend for industrial parts manufactured by metal press processing to be replaced by press-molded products made of fiber-reinforced thermoplastic resin, which are composed of relatively long reinforcing fibers and thermoplastic resin. be. The characteristic of fiber-reinforced thermoplastic resin is that heated fiber-reinforced thermoplastic resin sheet-shaped molding material (hereinafter referred to as sheet-shaped molding material) can be inserted into a room temperature or heated mold and processed in a short time. Complicated molded products can be produced by pressure molding, and furthermore, the molded products have high strength and are lightweight.

[0003] Methods for producing sheet-like molded materials can be classified into the following two types. ■Lamination method: Laminates matte reinforcing fibers and thermoplastic resin that have undergone needling (a process in which multiple reinforcing fiber bundles are pierced with needles and intertwined with each other), and then laminated between steel belts in a double-belt conveyor type continuous press. Continuously insert, heat and pressurize,
A method of manufacturing a sheet-shaped molding material by further cooling (Japanese Patent Application Laid-Open No. 48-80172, JP-A-52-40558, JP-A-55-77525), and ■ Paper-making method: Application of paper-making technology. Then, reinforcing fibers with a diameter of 3 to 30 μm φ and a length of 3 to 50 mm and thermoplastic resin powder are uniformly dispersed to produce a nonwoven material, and this nonwoven material is used as a raw material and heated, pressurized, and then cooled. Method for manufacturing sheet-like molded materials (Japanese Patent Publication No. 12283/1983, Japanese Patent Publication No. 55/1983)
9119).

[0004] In fiber-reinforced thermoplastic resin molded products, a problem arises in that the appearance deteriorates due to the reinforcing fibers being exposed on the surface of the molded product. A method of obtaining a laminated molded product by laminating a decorative skin on the surface of a heated sheet-shaped molded material and press-molding the two at the same time is an effective method for improving the appearance of fiber-reinforced thermoplastic resin molded products. This is a very effective method. Laminated molded products and methods for molding the same have been proposed for the purpose of improving the appearance of molded products using sheet-like molded materials manufactured by the lamination method. In this method, when laminating a sheet-shaped molded material and a breathable decorative skin, the thermoplastic resin passes through the skin and spoils the appearance. While preventing the passage of the foam, the thermoplastic resin of the sheet-shaped molding material is infiltrated into the foam and solidified to bond it (
Special Publication No. 62-1816).

[0005] The reinforcing fibers in the sheet-like molded material manufactured by the papermaking method are uniformly dispersed down to a single fiber in the thermoplastic resin, so the reinforcing fibers in the lamination method are restrained by needling. It exists in a less constrained state compared to . Therefore, when the sheet-shaped molding material is heated above the softening point or melting point of the thermoplastic resin matrix before molding, the bonding force of the thermoplastic resin to the reinforcing fibers weakens, causing a springback in which the reinforcing fibers try to return to their original state. This causes sheet expansion and increases exposure of reinforcing fibers.

Furthermore, the strength of fiber-reinforced thermoplastic resin molded articles improves as the content increases due to the reinforcing effect of the reinforcing fibers, but as the content of reinforcing fibers increases, the strength of the reinforcing fibers in the sheet-like molding material increases. The increased residual stress promotes sheet expansion due to springback and exposure of reinforcing fibers.

An example of a method for forming a laminated product is shown in FIG. 1(a).
It was shown to. A sheet-like molded material 1 is heated in a far-infrared heating furnace 2. A breathable decorative skin 5 is placed on the heated sheet-shaped molded material 4, inserted into a mold 6 and pressure-molded, and at the same time, the two are integrated to obtain a laminate molded product 7. The adhesive strength between the fiber-reinforced thermoplastic resin in the core of the laminate molded product and the breathable decorative skin is achieved by the anchoring effect caused by the thermoplastic resin penetrating into the decorative skin during pressure molding, solidifying, and bonding. do.

[0008] In the sheet-shaped molded material manufactured by the lamination method, the reinforcing fibers exist as multiple fiber bundles, so the thermoplastic resin flows relatively easily and can be directly integrally molded with the breathable decorative skin. In this case, it becomes a problem that the thermoplastic resin passes through the epidermis and impairs the appearance, so the above-mentioned Japanese Patent Publication No. 62-1816 has been devised.

On the other hand, in the case of a sheet-shaped molded material manufactured by a papermaking method, the adhesive strength between the fiber-reinforced thermoplastic resin and the breathable decorative skin decreases as the reinforcing fiber content increases. This is because the reinforcing fibers on the surface of the heating sheet are exposed more, and the flow of the thermoplastic resin inside the expanded sheet is inhibited by the presence of uniformly dispersed reinforcing fibers, and the thermoplastic resin flows onto the sheet surface during pressure molding. This is thought to be because it becomes difficult to seep out.

0010

[Problems to be Solved by the Invention] The present invention provides a laminated molded product that has good adhesive strength with a breathable decorative skin using a sheet-like molded material manufactured by a papermaking method, and a method for molding the same. It is.

[0011]

[Means for Solving the Problems] The present invention provides a fiber-reinforced thermoplastic resin layer with a reinforcing fiber content of 15% by volume or more formed by a paper-making method, and a space between an air-permeable decorative skin and the core. 5
A laminate molded product formed by heating and pressure molding with a thermoplastic resin layer containing ~30% by volume of inorganic filler, and a fiber-reinforced thermoplastic resin layer with a reinforcing fiber content of 15% by volume or more obtained by a papermaking method. is used as a core, and a thermoplastic resin layer containing 5 to 30% by volume of inorganic filler is interposed between the breathable decorative skin and the core, and heated and pressed using a mold. This is a method for forming a laminate molded product, which is characterized by integrating the entire product by molding.

An example of the method for molding the laminate molded product of the present invention is shown in FIG. 1(b). When the sheet-like molded material 8 of the present invention is heated, the fiber-reinforced thermoplastic resin layer 9 having a reinforcing fiber content of 15% by volume or more that constitutes the core expands;
The thermoplastic resin layer 10 containing 30% by volume of inorganic filler does not expand, and a large amount of molten thermoplastic resin exists on its surface. Furthermore, thermoplastic resins tend to flow easily even in the presence of inorganic fillers. Therefore, when integrally molded with the breathable decorative skin 5, the thermoplastic resin of the inorganic filler-containing thermoplastic resin layer 10 easily penetrates into the inside of the skin and becomes fixed, resulting in a laminate molded product 7 with good adhesive strength.
is obtained.

[0013] In the present invention, for the purpose of high molded product strength, in a laminated molded product using a sheet-like molded material with a high content of reinforcing fibers, bonding between the fiber-reinforced thermoplastic resin in the core and the breathable decorative skin is achieved. Strength was improved by interposing an inorganic filler-containing thermoplastic resin layer between the two and integrally molding them. The inorganic filler content in the intermediate layer is 5% by volume or more to avoid deterioration in appearance due to the thermoplastic resin passing through the epidermis and seeping onto the surface, allowing stable molding of the inorganic filler-containing thermoplastic resin film. 30% by volume
The following shall apply.

In the present invention, as inorganic fillers, fine particulate fillers such as calcium carbonate and talc, plate fillers such as mica, fibrous fillers such as chopped glass fibers and rock wool fibers, or a mixture of two or more thereof are used. use The surface of the inorganic filler is desirably treated with a silane coupling agent or the like in order to improve adhesiveness with the thermoplastic resin for the purpose of developing strength.

[0015] The thermoplastic resin that is the matrix of the inorganic filler-containing thermoplastic resin layer is generally the same as that of the fiber-reinforced thermoplastic resin layer to be laminated. For the purpose of improvement, those modified with active groups or mixtures with different resins may be used. The inorganic filler and thermoplastic resin are preferably kneaded using an extruder in order to achieve uniform dispersion, and it is desirable to laminate a film formed using a T-die or the like on the fiber-reinforced thermoplastic resin.

[0016] The fiber content of the fiber-reinforced thermoplastic resin layer of the core in the present invention is 15% by volume or more, which lowers the adhesive strength with the breathable decorative skin, and allows the reinforcing fibers to bond with the thermoplastic resin. It is desirable that the content be 40% by volume or less to sufficiently exhibit the strength of a fiber-reinforced thermoplastic resin molded product. More preferably, it is in the range of 15.9 to 30% by volume.

As the reinforcing fibers, in addition to glass fibers, carbon fibers, and metal fibers, inorganic fibers and organic fibers can be used. The shape of the reinforcing fibers is preferably 3 μm φ or more in diameter from the viewpoint of ease of handling and economical aspects, and 30 μm φ or less in order to develop sufficient strength, and the fiber length is 3 mm or more from the viewpoint of developing strength. It is desirable that the thickness be 50 mm or less to enable uniform dispersion. In addition, the reinforcing fibers are made of water-soluble polymers and wetting agents to improve hydrophilicity for the purpose of good dispersion in water, and silane coupling agents to improve adhesion with thermoplastic resins for the purpose of developing strength. It is preferable to perform surface treatment with, etc.

Thermoplastic resins include polyethylene, polypropylene, polystyrene, styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polyamide, polycarbonate, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, It is a resin such as polyphenylene sulfide, and these two
It also includes mixtures of different kinds or more, and to which commonly used plasticizers, heat stabilizers, light stabilizers, fillers, dyes and pigments, impact resistance agents, fillers, nucleating agents, processing aids, etc. are added. You can also. As the breathable decorative skin, woven fabrics made of natural or synthetic fibers, needle-punched nonwoven fabrics, raised woven fabrics, knitted fabrics, flocked fabrics, etc. are used.

FIG. 2 shows an example of the manufacturing process of a sheet-shaped molded material using the papermaking technique. Diameter 3μm φ~30μm
φ, reinforcing fiber 1 such as glass fiber with a length of 3 mm to 50 mm
1 and thermoplastic resin powder 12 are continuously introduced into water in a dispersion tank 13. In the dispersion tank, stirring is performed to uniformly disperse the reinforcing fibers and resin powder, and the dispersion liquid is further supplied by a pump 14 to a head box 16 installed above a mesh belt conveyor 15. The wet box 17 installed at the bottom of the head box is maintained at a negative pressure, and the dispersion inside the head box is continuously sucked and dehydrated to create a composite body in which reinforcing fibers and thermoplastic resin powder are uniformly dispersed. A nonwoven material 18 is produced. This nonwoven material is dried in a hot air dryer 19, and at the same time, part or all of the thermoplastic resin is heated to a temperature higher than its softening point or melting point to melt it, and then cooled to convert the reinforcing fibers into thermoplastic resin. It is a non-woven material bonded with resin. Furthermore, it is heated and pressurized with a double belt conveyor type continuous press 20, further cooled and formed into a sheet shape, and finally reeled up 2
1, or cut with a cutter 22 into a shape according to the dimensions required for hot-press molding to produce a sheet-like molding material 1. The sheet-shaped molding material may be one in which voids are completely removed when a nonwoven material is molded using a double-belt conveyor type continuous press, or one in which voids are present.

The sheet-shaped molded material of the present invention is manufactured by laminating an inorganic filler-containing thermoplastic resin film molded with a T-die or the like of an extruder on a fiber-reinforced thermoplastic resin, heating and pressurizing it with a press molding machine, and then This can be easily done by cooling and molding. As an industrial method, the lamination process shown in FIG. 3 can be provided between the hot air dryer 19 and the double belt conveyor type continuous press 20 in the manufacturing process of the sheet-shaped molded material shown in FIG. Efficient. The thermoplastic resin 23 and the inorganic filler 24 are kneaded in an extruder 25 to achieve uniform dispersion, and further formed into an inorganic filler-containing thermoplastic resin film 27 in a T-die 26 and supplied to the surface of the nonwoven material 18. Ru. The nonwoven material and the inorganic filler-containing thermoplastic resin film are heated and pressed in a double belt conveyor type continuous press 20.
It is further cooled to produce an inorganic filler-containing thermoplastic resin laminated sheet-like molding material 8 used in the present invention. The thickness of the inorganic filler-containing thermoplastic resin film to be laminated is preferably set to the minimum necessary value to ensure good adhesive strength with the breathable decorative skin, in order to place emphasis on the strength of the molded product.

In place of the nonwoven material in the lamination process shown in FIG. 3, it is easy to use a sheet material formed from a nonwoven material using a double belt conveyor type continuous press or the like. In addition, in Figure 3, a thermoplastic resin containing inorganic filler is laminated on one side of the nonwoven material, but the appearance of both sides is required to be improved depending on the application of the molded product, so a breathable decorative skin is laminated on both sides of the sheet-shaped molded material. When molding a laminate molded product, a sheet-like molding material is used in which a thermoplastic resin containing an inorganic filler is laminated on both sides of a nonwoven material.

In the present invention, as shown in FIG. 1(b), a fiber-reinforced thermoplastic resin layer 9 having a reinforcing fiber content of 15% by volume or more and a thermoplastic resin layer 10 containing 5 to 30% by volume of inorganic filler are used. It is desirable to use a sheet-like molded material 8 that has been laminated and molded in advance. When using a fiber-reinforced thermoplastic resin sheet material with a reinforcing fiber content of 15% by volume or more and an inorganic filler-containing thermoplastic resin film in a layered manner during heating, use a sheet-like material that has been laminated and molded in advance. You can get the same effect as when you use it. However, since the process of cutting the two types of molding materials into shapes according to the molded product and overlapping them is increased, it is advantageous in terms of the process to use sheet-like molding materials that have been laminated and molded in advance.

[0023]

[Examples] The present invention will be explained in detail with reference to Examples below. [Example 1] As reinforcing fiber, diameter 10 μm φ, length 1
3mm diameter glass fiber and thermoplastic resin
A spherical pellet of mφ is mechanically crushed, and the crushed product is sieved and classified into 70 mesh (opening diameter 0.212 mm) to 10 mesh (opening diameter 1.7 mm). Using polypropylene resin powder, the glass fiber content is determined by a papermaking method. A nonwoven material having a composition of 40% by weight (19.0% by volume) and 60% by weight (81.0% by volume) of polypropylene resin and a basis weight of 3000 g/m2 was manufactured.

A talc-containing polypropylene resin film was produced using fine particulate talc with a diameter of 3 μm φ as an inorganic filler and the above polypropylene resin as a thermoplastic resin. The film contains 15% by weight of talc (5.4
% by volume) and a polypropylene resin of 85% by weight (94.6% by volume) were kneaded using an extruder, and the mixture was kneaded using a T-die to a thickness of 0.5% by volume.
It was molded to 4 mm.

One sheet of the above nonwoven material and one sheet of talc-containing polypropylene resin film were laminated and hot press molded to produce a sheet-shaped molded material having a thickness of 2.9 mm. The hot press molding conditions were as follows: preheating was carried out at 210° C. for 5 minutes with no load, followed by pressing at a pressure of 20 kgf/cm 2 for 5 minutes, cooling and solidifying to form a sheet.

[Example 2] Using the same talc and polypropylene resin as in Example 1, 20% by weight (7.4% by volume) of talc and 8% by volume of polypropylene resin were prepared in the same manner as in Example 1.
Composition of 0% by weight (92.6% by volume), thickness 0.4mm
A film was formed. One sheet of the nonwoven material of Example 1 and one sheet of this talc-containing polypropylene resin film were laminated to produce a sheet-like molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[Example 3] Using the same talc and polypropylene resin as in Example 1, 30% by weight (12.1% by volume) of talc and 70% by weight (87.9% by volume) of polypropylene resin were prepared in the same manner as in Example 1. Volume %), thickness 0.4m
A film of m was molded. One sheet of the nonwoven material of Example 1 and one sheet of this talc-containing polypropylene resin film were laminated to produce a sheet-like molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[Example 4] Using the same talc and polypropylene resin as in Example 1, 40% by weight (17.6% by volume) of talc and 60% by weight (82.4% by volume) of polypropylene resin were prepared in the same manner as in Example 1. Volume %), thickness 0.4m
A film of m was molded. One sheet of the nonwoven material of Example 1 and one sheet of this talc-containing polypropylene resin film were laminated to produce a sheet-like molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[Example 5] Using the same talc and polypropylene resin as in Example 1, 50% by weight of talc (24.3% by volume) and 50% by weight of polypropylene resin (75.7% by volume) were prepared in the same manner as in Example 1. Volume %), thickness 0.4m
A film of m was molded. One sheet of the nonwoven material of Example 1 and one sheet of this talc-containing polypropylene resin film were laminated to produce a sheet-like molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[Comparative Example 1] Using the same talc and polypropylene resin as in Example 1, 10% by weight (3.4% by volume) of talc and 9% by volume of polypropylene resin were prepared in the same manner as in Example 1.
Composition of 0% by weight (96.6% by volume), thickness 0.4mm
A film was formed. One sheet of the nonwoven material of Example 1 and one sheet of this talc-containing polypropylene resin film were laminated to produce a sheet-like molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[Comparative Example 2] Using the same polypropylene resin as in Example 1, a thickness of 0.4 m was prepared in the same manner as in Example 1.
A polypropylene resin film of m was molded. Example 1
A sheet-like molded material having a thickness of 2.9 mm was produced in the same manner as in Example 1 by laminating one sheet of the nonwoven material and one sheet of this polypropylene resin film.

Using the sheet-like molding materials of Examples and Comparative Examples, laminate molded products were molded by the method shown in FIG. The sheet-shaped molded material was cut into 15 x 15 cm pieces, heated in a far-infrared heating furnace until the surface temperature of the laminated film side reached 210°C, and then a breathable decorative skin was applied to that surface with a basis weight of 230 g/ m 2 of polyester fiber nonwoven fabrics were laminated, inserted into a mold whose temperature was controlled to 40° C., and press-molded at a pressure of 50 kgf/cm 2 to form a flat plate laminate molded product. The adhesive strength between the fiber-reinforced thermoplastic resin part and the skin of each laminate molded product was measured by a 90 degree peel test, and the results are shown in Table 1.

[Table 1]

[0034]

In the laminate molded product of the present invention, there was no deterioration in appearance due to the passage of the polypropylene resin through the skin, and good adhesive strength was obtained. This is because the fluidity of the polypropylene resin in the talc-containing polypropylene resin layer was suppressed to such an extent that good adhesive strength with the epidermis could be developed in the presence of 5% by volume or more of talc. In the peel test,
Because the epidermis was cut or peeled off while being damaged, much of the epidermis remained on the peeled surface after the test, and it was confirmed that the polypropylene resin had sufficiently penetrated into the epidermis and was fixed. In the comparative example, good adhesive strength was obtained, but the appearance deteriorated due to the passage of the polypropylene resin through the epidermis. This occurred because the talc content was low and the fluidity of the polypropylene resin was less reduced.

[Example 6] As an inorganic filler, a diameter of 1
Using chopped glass fibers with a diameter of 0 μm and a length of 3 mm and the same polypropylene resin as in Example 1, a composition of 20% by weight (8.1% by volume) of chopped glass fibers and 80% by weight (91.9% by volume) of polypropylene resin was prepared. , Example 1
Knead with an extruder in the same manner as above, and use a T-die to make a 0.4mm thick mixture.
A chopped glass fiber-containing polypropylene resin film was molded. One sheet of the nonwoven material of Example 1 and one sheet of this chopped glass fiber-containing polypropylene resin film were laminated to produce a sheet-shaped molded material having a thickness of 2.9 mm in the same manner as in Example 1.

[0037] Using this sheet-like molded material, the basis weight was 230 g/m2 in the same manner as in the above-mentioned Examples and Comparative Examples.
A flat plate laminate molded product was formed by laminating polyester fiber nonwoven fabrics, and the adhesive strength between the fiber-reinforced thermoplastic resin portion of the laminate molded product and the skin was measured by a 90 degree peel test. In Example 6 as well, there was no deterioration in appearance due to the passage of the polypropylene resin through the skin, and good adhesive strength was obtained. The adhesive strength was 3.0 kgf/cm2, and the epidermis was broken during the peel test. The chopped glass fibers of the inorganic filler layer were broken down to an average fiber length of about 0.5 mm by kneading with an extruder, and were uniformly dispersed.

[0038]

[Effects of the Invention] According to the present invention, in a laminate molded product using a sheet-like molded material produced by a papermaking method, the adhesive strength between the fiber-reinforced thermoplastic resin core and the breathable decorative skin has been improved. Although the present invention can be used in general heat and pressure molding, it also provides beneficial results in air pressure molding.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are schematic diagrams showing an example of molding processing of a laminated molded product.

FIG. 2 is a schematic diagram showing an example of a manufacturing process of a sheet-like molded material using papermaking technology.

FIG. 3 is a schematic diagram showing an example of a process of laminating an inorganic filler-containing thermoplastic resin onto a fiber-reinforced thermoplastic resin.

[Explanation of symbols]

1 Sheet-shaped molded material 2 Far-infrared heating furnace 3 Exposure due to springback of reinforcing fibers 4
Heated sheet-like molded material 5 Breathable decorative skin 6 Molding mold 7 Laminated molded product 8 Sheet-like molded material of the present invention 9 Fiber-reinforced thermoplastic resin layer with reinforcing fiber content of 15% by volume or more 10 Inorganic filler-containing thermoplastic Resin layer 11 Reinforcing fiber 12 Thermoplastic resin powder 13 Dispersion tank 14 Pump 15 Mesh belt conveyor 16 Head box 17 Wet box 18 Nonwoven material 19 Hot air dryer 20 Double belt conveyor type continuous press 21 Reel up 22 Cutter 23 Thermoplastic resin 24 Inorganic filler 25 Extruder 26 T-die

Claims (2)

[Claims] Claim 1: The core is a fiber-reinforced thermoplastic resin layer formed by a papermaking method and has a reinforcing fiber content of 15% by volume or more, and an inorganic filler of 5 to 30% by volume is provided between the breathable decorative skin and the core. A laminate molded product formed by heating and pressure molding with a thermoplastic resin layer containing . 2. A fiber-reinforced thermoplastic resin layer with a reinforcing fiber content of 15% by volume or more formed by a papermaking method as a core, and an inorganic filler of 5 to 30% by volume between the breathable decorative skin and the core. With a thermoplastic resin layer containing
A method for molding a laminate molded product, characterized in that the whole is integrated by heating and pressure molding using a mold.