JP2003334879A - Fiber reinforced composite molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a fiber reinforced composite molded product capable of achieving the weight reduction of a laminated product even when a net-like article comprising thermoplastic resin fibers is integrally laminated to a thermoplastic resin molded product, and having physical strength keeping the net-like article as it is without melting the net-like article or collapsing the reticulated shape thereof. <P>SOLUTION: A thermoplastic resin film having a melting point lower than that of thermoplastic resin fibers is laminated on the single surface or both surfaces of the net-like article comprising thermoplastic resin films with a mesh interval of 1-15 mm to form a thermoplastic resin fiber laminated sheet. This laminated sheet is laminated to at least a part of the thermoplastic resin molded product. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fiber-reinforced composite molded article.

[0002]

2. Description of the Related Art Conventionally, for the purpose of improving physical strength such as impact resistance and rigidity of a thermoplastic resin molded product, a net-like material such as a woven fabric or knitted fabric made of reinforcing fibers is laminated on the thermoplastic resin molded product. Known fiber-reinforced composite molded products are widely used as automobile interior materials and building materials.

For example, a thermoplastic resin molded product reinforced with a net-like material made of glass fiber or carbon fiber is known as a typical fiber-reinforced composite molded product, and reinforcement made of such an inorganic fiber material is used. The material was extremely difficult to separate from the thermoplastic resin molded product, and it was difficult to recycle and use the fiber-reinforced composite molded product.

Due to such a problem of recyclability, in recent years, a woven fabric or a knitted fabric made of a thermoplastic resin fiber instead of the glass fiber or the carbon fiber has been often used as a reinforcing material. In general, a knitted fabric has a fine mesh and a large weight per unit area, so that there is a problem that weight reduction cannot be achieved.

As a solution to such a problem, it is conceivable that a net-like material having a large mesh made of thermoplastic resin fibers is laminated on a thermoplastic resin molded product to obtain a thermoplastic resin fiber-reinforced composite molded product. Such a thermoplastic resin fiber-reinforced composite molded article is formed by, for example, forming a thermoplastic resin molded article by an injection molding method or an injection compression molding method, and at the same time laminating and integrating a net-like material with the thermoplastic resin molded article. Although it can be manufactured, since the composite molded product obtained by such a method has a large net-like mesh, the molten resin supplied in the manufacturing process leaks from the mesh and climbs onto the net-like material. , The shape of the net-like object collapses, or the heat of the molten resin is directly transferred to the net-like object, so the thermoplastic resin fibers that compose the net-like object are melted and the shape of the net-like object cannot be maintained. There is a problem that the mechanical properties originally possessed by the material are impaired.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The present inventors not only achieve weight reduction of the laminated product but also melt the net-shaped product when the net-shaped product made of the thermoplastic resin fiber is laminated and integrated with the thermoplastic resin molded product. As a result of investigations to develop a fiber-reinforced composite molded product excellent in physical strength in which the mesh shape is maintained as it is, the present invention has been achieved.

[0007]

That is, the present invention provides a thermoplastic resin film having a melting point lower than that of the thermoplastic resin fibers on one or both sides of a net-like article made of thermoplastic resin fibers having a mesh spacing of 1 to 15 mm. The present invention provides a fiber-reinforced composite molded article obtained by laminating a thermoplastic resin fiber laminated sheet obtained by laminating the above on at least a part of the thermoplastic resin molded article.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The fiber-reinforced composite molded article of the present invention will be described below.

In the fiber-reinforced composite molded article of the present invention, a thermoplastic resin film having a melting point lower than that of the thermoplastic resin fiber is laminated on one side or both sides of a net-like material made of thermoplastic resin and having a mesh spacing of 1 to 15 mm. The thermoplastic resin fiber laminated sheet thus obtained is laminated on at least a part of the thermoplastic resin molded article.

The net-like material composed of thermoplastic resin fibers applied to the present invention is a material in which thermoplastic resin fibers are woven in a mesh shape, for example, a lattice shape by a usual method, and is used as a weight-reducing and reinforcing material. In consideration of the reinforcing effect in the case of, when the mesh size of the net-like material is too small, it becomes insufficient in terms of weight reduction, while when it is too wide, the reinforcing effect cannot be obtained sufficiently, so both effects are well balanced. In order to be satisfied, the mesh spacing needs to be in the range of 1 to 15 mm, and particularly preferably in the range of 2 to 8 mm.

The thermoplastic resin fiber constituting the net-like material may be a single fiber or a fiber bundle in which several single fibers are gathered, but the reinforcing effect as a net-like material is considered. For example, the thermoplastic resin fiber is more preferably a fiber bundle. The thickness of the monofilament varies depending on the type of thermoplastic resin constituting the fiber and is appropriately selected according to each type, but is generally about 1 to 50 denier.

For example, in the case of a fiber made of an olefin resin, it is preferable to use a fiber having a denier of about 1 to 20;
It is more preferable to use one having a denier of about 0.
When using a fiber bundle in which such single fibers are aggregated, if the number of single fibers converged (the number of filaments) is too small, the mechanical strength of the fiber bundle itself is weak and a sufficient reinforcing effect cannot be obtained. Considering that the weight per unit area will increase if the value is too large, the number of filaments is generally preferably in the range of about 10 to 500.
The range of about 0 to 200 is more preferable.

The thermoplastic resin constituting the thermoplastic resin fiber is not specified at all as long as it has a fusion property with the thermoplastic resin film described later, and examples thereof include polypropylene, polyethylene, and propylene / ethylene copolymer. General thermoplastic resins such as olefin resin such as acrylonitrile-styrene-butadiene block copolymer, polystyrene, polyamide such as nylon, polyvinyl chloride, polycarbonate, acrylic resin, styrene-butadiene block copolymer and these Examples include mixtures, polymer alloys using these,
In the present invention, these are collectively referred to as a thermoplastic resin.

To such a thermoplastic resin, various additives which are usually used, for example, antioxidants, ultraviolet absorbers,
An antistatic agent, a lubricant, a dispersant, a chlorine scavenger, a metal deactivator, a flame retardant, a pigment and the like may be appropriately added according to each purpose.

Further, these thermoplastic resins may be modified with unsaturated acids or unsaturated acid anhydrides, and as the unsaturated acids and unsaturated acid anhydrides, acrylic acid, methacrylic acid, maleic acid, anhydrous Examples include maleic acid, fumaric acid, itaconic acid, itaconic anhydride, mesaconic acid, citraconic acid, crotonic acid, isocrotonic acid, angelic acid and the like.

The thermoplastic resin fiber used as the raw material for the net-like material is produced by the usual method using the above-mentioned thermoplastic resin, but it is stretched in the longitudinal direction of the fiber in order to improve the mechanical strength. It is preferably a fiber, and the higher the draw ratio, the more preferable, but it is usually about 2 to 20 times.

The thermoplastic resin fiber laminated sheet applied to the present invention is one in which a thermoplastic resin film is laminated on one side or both sides of a net-like material made of such a thermoplastic resin fiber, one example of which is shown. As shown in FIG. 1, in terms of weight reduction and material cost of the thermoplastic resin fiber laminated sheet,
The thermoplastic resin film is often laminated on only one side of the net-like material. Incidentally, FIG. 1 shows an example in which the thermoplastic resin film (2) is laminated on both surfaces of the net-like material (1).

The thermoplastic resin fiber laminated sheet can be produced by any method according to a known method. For example, in the case of manufacturing by the film stacking method, a thermoplastic resin is formed into a film by a usual method, and this film is laminated on one or both sides of a net-like object, and then heated by a heat press or the like to form the film and the net-like shape. It is possible to use a method of manufacturing a thermoplastic resin fiber laminated sheet by fusing and integrating the objects and cooling.

Further, in the case of extrusion molding, a thermoplastic resin is extruded into a film shape by extrusion molding, a net-like material made of thermoplastic resin fibers is supplied onto the film, and the film is heated by a heat roll or the like and extruded. It is also possible to use a method in which a net-like material is continuously fused and integrated.

Examples of the thermoplastic resin film include polypropylene, polyethylene, acrylonitrile-styrene-butadiene block copolymer, polystyrene, polyamide such as nylon, polyvinyl chloride, polycarbonate, acrylic resin, styrene-butadiene block copolymer, and the like. Examples thereof include a film made of a general thermoplastic resin, a mixture thereof, or a film made of a polymer alloy using these, and specifically, in combination with a net-like material to be laminated, the net-like material is constituted. A thermoplastic resin film having a melting point lower than that of the thermoplastic resin fiber is selected and used.

In the combination of the above-mentioned net-like material made of thermoplastic resin fibers and the thermoplastic resin film,
Considering environmental properties and recyclability, it is preferable that both the thermoplastic resin fiber and the thermoplastic resin film are made of an olefin resin, particularly a propylene resin. In this case, the thermoplastic resin fiber is preferably a propylene resin having a melting point of 165 ° C. or higher, and the thermoplastic resin film is preferably a film having a lower melting point, for example, a propylene / ethylene random copolymer.

The fiber-reinforced composite molded article of the present invention is obtained by laminating such a thermoplastic resin fiber laminated sheet on at least a part of the thermoplastic resin molded article on the side of the thermoplastic resin film. In FIG. 2 (A), the thermoplastic resin fiber laminated sheet (3) is placed on the entire upper surface of the thermoplastic resin molded product (4), and in FIG. 2 (B), the thermoplastic resin molded product (4) is mounted on the upper surface. An example in which they are partially laminated is shown in each cross section. In the figure, the example in which the thermoplastic resin fiber laminated sheet (3) is laminated on the upper surface (front surface) of the thermoplastic resin molded product (4) is shown. ), And the left and right side surfaces may be appropriately laminated on all or a part thereof, and the laminated portion is not limited at all.

Further, a plurality of thermoplastic resin fiber laminated sheets may be laminated at a plurality of points on the surface of the thermoplastic resin molded product, and a plurality of thermoplastic resin fiber laminated sheets may be laminated at the same location for the purpose of improving the reinforcing effect. May be stacked in a stacked state.

The method for laminating the thermoplastic resin fiber laminated sheet on the thermoplastic resin molded product is arbitrary, and the thermoplastic resin molded product may be laminated and adhered by heat fusion or may be laminated and adhered by an adhesive. In order to improve the property, the thermoplastic resin film of the thermoplastic resin fiber laminated sheet may be surface-treated in advance. Corona discharge treatment, plasma treatment and the like are generally used as such surface treatment methods.

The target thermoplastic resin molded article may be a foamed molded article or a non-foamed molded article.
When it is required to reduce the weight of the thermoplastic resin molded product, the foamed molded product is preferable, and the expansion ratio in this case is 1.1 to 10.
It is desirable to be about double.

The method for laminating the thermoplastic resin fiber laminated sheet on the thermoplastic resin molded product is arbitrary as described above, but in practice, it is possible to use a gold sheet according to a conventionally known method such as injection molding or injection compression molding. A thermoplastic resin fiber laminated sheet is pre-supplied between the molds so that the thermoplastic resin film is inside the cavity, and then a molten foamable or non-foamable thermoplastic resin is supplied between the molds for shaping. Thus, a method of forming a foamed or non-foamed thermoplastic resin molded product and at the same time laminating the thermoplastic resin fiber laminated sheet on the foamed or non-foamed thermoplastic resin molded product is advantageous.

When the thermoplastic resin molded product is in the form of a sheet, a foamed or non-foamed sheet is formed by extruding a foamed or non-foamed molten thermoplastic resin by extrusion molding according to a conventionally known method. Then, a method of supplying the thermoplastic resin resin fiber laminated sheet to the surface of the sheet, thermocompression bonding with a heat roll or the like, and fusing and integrating the thermoplastic resin resin fiber laminated sheet with the extruded thermoplastic resin sheet can be mentioned. . Alternatively, a thermoplastic resin / resin fiber laminated sheet may be supplied to the surface of a foamed or non-foamed sheet formed in advance and fused and integrated in the same manner as above. In any of these methods, the thermoplastic resin resin fiber laminated sheet is arranged so that the thermoplastic resin film faces the surface of the thermoplastic resin molded product.

In the case where the thermoplastic resin molded product is formed and the thermoplastic resin fiber laminated sheet is laminated on the thermoplastic resin molded product at the same time, the molten heat supplied between the molds in the molding process is used. The thermoplastic resin is capable of maintaining the shape of the net-like material without leaking from the mesh of the net-like material by the thermoplastic resin film laminated on the thermoplastic resin fiber laminated sheet, and
Since the heat of the molten thermoplastic resin is not directly transferred to the thermoplastic resin fibers that make up the net-like material, the thermoplastic resin fiber laminated sheet is laminated on the thermoplastic resin molded product without melting the thermoplastic resin fibers. be able to.

In addition, as a method for laminating the thermoplastic resin molded product and the thermoplastic resin fiber laminated sheet, the previously formed thermoplastic resin molded product and the thermoplastic resin fiber laminated sheet may be laminated with an adhesive or the like. Again, this is usually
The thermoplastic resin film of the thermoplastic resin / resin fiber laminated sheet is arranged so as to face the surface of the thermoplastic resin molded product.

As the thermoplastic resin constituting the thermoplastic resin molded article, resins usually used in compression molding, injection molding and the like are applied, and examples thereof include polypropylene, polyethylene, acrylonitrile-styrene-butadiene block copolymer, polystyrene, Polyamide such as nylon,
Examples include general thermoplastic resins such as polyvinyl chloride, polycarbonate, acrylic resins, and styrene-butadiene block copolymers, thermoplastic elastomers such as EPM and EPDM, mixtures thereof, and polymer alloys using these. Considering environmental properties and recyclability, it is preferable to use an olefin resin such as polypropylene or polyethylene.

Of course, these thermoplastic resins may be blended with fillers such as various inorganic or organic fillers if necessary, and various commonly used pigments, lubricants, antistatic agents, Various additives such as stabilizers may be blended.

The fiber-reinforced composite molded article of the present invention is a product obtained by laminating such a thermoplastic resin fiber laminated sheet on at least a part of the thermoplastic resin molded article. From the viewpoint of the recyclability of the thermoplastic resin, or the fusible (adhesive) properties of the thermoplastic resin film, the thermoplastic resin film, and the thermoplastic resin molded product in the manufacturing process of the product, The thermoplastic resin film and the thermoplastic resin molded product are more preferably the same type of thermoplastic resin, and among them, the olefin resin, particularly the propylene resin, is preferable.

In this case, the relationship between the thermoplastic resin fiber and the thermoplastic resin film is as described above, but the melting point of the thermoplastic resin forming the thermoplastic resin molded article is preferably higher than that of the thermoplastic resin film.

Further, in the fiber-reinforced composite molded article of the present invention, a skin material other than the thermoplastic resin fiber laminated sheet may be overlapped with the thermoplastic resin fiber laminated sheet, or different from the sheet, if necessary. It may be directly bonded to the surface of the thermoplastic resin molded product at a position. Examples of the skin material include a nonwoven fabric such as a needle punch carpet, a metal foil, a sheet or a film made of a thermoplastic resin or a thermoplastic elastomer, and the like.

These skin materials may be laminated skin materials having two layers or three or more layers in which a foaming layer and a backing layer are appropriately laminated as required, but a portion different from the thermoplastic resin fiber laminated sheet. When it is pasted with, it can be directly heat-sealed to the thermoplastic resin molded product, or it can be adhered to the thermoplastic resin molded product by impregnating the back surface of the skin material with the molten thermoplastic resin. Is preferred.

As the foam layer of such a skin material, a polyolefin foam such as polypropylene or polyethylene, a polyvinyl chloride foam, or a soft or semi-rigid polyurethane foam is preferably used.

[0037]

EFFECT OF THE INVENTION The fiber-reinforced composite molded article of the present invention has a small basis weight of the reinforcing material because the net-like material made of the thermoplastic resin fiber as the reinforcing material has a coarse mesh spacing.
It is possible to reduce the weight of the molded product, and moreover, because the net material that is the reinforcing material is maintained as it is without melting or the mesh shape being collapsed, it has excellent physical strength. There is.

[0038]

EXAMPLES The present invention will be described below with reference to examples, but it goes without saying that the present invention is not limited to the examples.

Example 1 Polypropylene fiber (SIMTEX, manufactured by Ube Nitto Kasei Co., Ltd., 60 filaments, fiber thickness 3 denier, melting point 170)
(° C) was knitted to obtain a net-like product having a minimum mesh spacing of 2 mm. On the other hand, a propylene / ethylene random copolymer (Sumitomo Chemical Co., S131, melting point about 130 ° C.) is formed into a film by a usual method, and the film is laminated on one side of the net-like material to heat the net-like material and the film. Heat fusion was performed by a press to obtain a polypropylene fiber laminated sheet. This polypropylene fiber laminated sheet is supplied between molds of male and female dies, and a molten propylene-based resin is supplied from the film side of the polypropylene fiber laminated sheet, and then the mold is clamped and shaped to obtain a propylene-based resin. A fiber-reinforced composite molded product was obtained in which a polypropylene fiber laminated sheet was attached to the surface of the molded product. The obtained fiber-reinforced composite molded product is a resin molded product in a state where the molten resin does not leak from the mesh of the net-like material and the propylene-based fibers constituting the net-like material do not melt and maintain its shape. It was pasted.

Comparative Example 1 A fiber-reinforced composite molded article was obtained in the same manner as in Example 1 except that the same net-like material as obtained in Example 1 was fed as it was between the male and female dies. In the obtained fiber-reinforced composite molded product, the molten resin leaked from the mesh of the net-like material, and the propylene-based fibers constituting the net-like material were also partially melted to lose its shape.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a thermoplastic resin fiber laminated sheet applied to a fiber-reinforced composite molded article of the present invention.

FIG. 2 is a cross-sectional view showing an example of a fiber-reinforced composite molded article of the present invention in which a thermoplastic resin fiber laminated sheet is laminated, and (A) shows the entire upper surface of the thermoplastic resin molded article.
(B) shows an example of laminating on a part of the upper surface of the thermoplastic resin molded product.

[Explanation of symbols]

1: Net-like material made of thermoplastic resin fiber 2: Thermoplastic resin film 3: Thermoplastic resin fiber laminated sheet 4: Thermoplastic resin molded product 5: Fiber reinforced composite molded product

Continued front page    F term (reference) 4F100 AK01B AK01C AK03A AK03B                       AK03C AK07A AK07B AK07C                       AK64A AK64B AK64C AL03A                       AL03B AL03C BA02 BA03                       BA06 BA07 BA10B BA10C                       BA26 DC16A DG01A DJ01B                       DJ01C EC022 EC03 EH17                       EH172 EJ02 EJ022 GB08                       GB33 JA04A JA04B JA04C                       JB16A JB16B JB16C JL03                       JL04 YY00A YY00B YY00C

Claims (6)

[Claims] 1. A thermoplastic resin fiber obtained by laminating a thermoplastic resin film having a melting point lower than that of the thermoplastic resin fiber on one or both sides of a net-like article made of thermoplastic resin fiber having a mesh spacing of 1 to 15 mm. A fiber-reinforced composite molded article obtained by laminating a laminated sheet on at least a part of a thermoplastic resin molded article. 2. The fiber-reinforced composite molded article according to claim 1, wherein the thermoplastic resin molded article is a foamed molded article. 3. The fiber-reinforced composite molded article according to claim 1, wherein the thermoplastic resin fiber, the thermoplastic resin film and the thermoplastic resin molded article are made of an olefin resin. 4. The fiber-reinforced composite molded article according to claim 3, wherein the olefin resin is a propylene resin. 5. The fiber-reinforced composite molded article according to claim 4, wherein the propylene-based resin constituting the thermoplastic resin fiber is a propylene-based resin having a melting point of 165 ° C. or higher. 6. The fiber-reinforced composite molded article according to claim 4, wherein the propylene-based resin constituting the thermoplastic resin film is a propylene / ethylene random copolymer.