JP2001179819A - Method for producing surface-decorative molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a surface-decorative molding which is easy to decorate the surface of a sheet and reduces the directional differences in mechanical properties. SOLUTION: The sheet in which reinforcing short fibers are oriented randomly in a thermoplastic resin is coated with a decorative film, and at least part of the sheet coated with the film is heat-molded stepwise while being fusion- bonded to the decorative film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a surface-decorated molded product. In this specification, “sheet”
The term “sheet” does not mean a sheet in a strict sense based on the thickness, but includes a relatively thick sheet.

[0002]

2. Description of the Related Art Conventionally, it is generally known to obtain a surface decorative molded product by extruding a sheet comprising a thermoplastic resin and reinforcing fibers into a desired shape and laminating a decorative film.

[0003]

However, in forming the above-mentioned surface decorative molded product, it is troublesome to laminate the decorative film, and it is difficult to obtain a thin molded product. Was.

[0004] It is an object of the present invention to solve the above-mentioned problems and to provide a method of manufacturing a surface-decorated molded article which is easy to decorate a sheet surface and has excellent mechanical strength.

[0005]

According to the present invention, there is provided a method for producing a surface-decorated molded product, comprising: applying a decorative film to a sheet in which reinforcing short fibers are substantially randomly oriented in a thermoplastic resin; Is formed by heating in a stepwise manner while fusing at least a part of the sheet coated with the decorative film.

[0006] The thermoplastic resin used in the present invention is not particularly limited as long as it is softened when heated and exhibits plasticity. For example, a thermoplastic polyester resin such as polyethylene terephthalate; a polyamide resin; Resins, olefin resins such as polyethylene and polypropylene; vinyl chloride resins and the like are preferably used.

The reinforcing short fibers used in the present invention are not particularly limited, and any fibers can be used as long as they can withstand the molding temperature of the thermoplastic resin. Examples of the fibers include carbon fibers, metal fibers, and glass fibers. Inorganic fibers; organic fibers such as Kepler and cotton fibers can be suitably used.

The length and diameter of the reinforcing short fibers are appropriately selected according to the required performance of the sheet.
１００100 mm and a diameter of 5５０50 μm are often used.

In the present invention, the reinforcing short fibers are oriented almost randomly in the thermoplastic resin. Substantially randomly oriented refers to the ratio of the strength or elastic modulus (F ₁₁ /) in any direction orthogonal to each other in a state of being dispersed in a thermoplastic resin.
F ₂₂ or E ₁₁ / E ₂₂₎ is, say that it is 0.5 to 1.0.

In the present invention, the method for randomly orienting the reinforcing short fibers in the thermoplastic resin is not particularly limited. For example, 1) the first thermoplastic resin is impregnated by a powder impregnation method or a liquid impregnation method. A method of obtaining a sheet in which the short fibers oriented in a substantially random manner are fixed with a resin, and laminating the band to obtain a sheet. 2) The thermoplastic resin short fibers and the reinforcing short fibers are air-flowed. A method of heating and pressing at a temperature equal to or higher than the softening temperature of the thermoplastic resin by skipping and depositing in a layered form. 3) Cutting the thermoplastic resin short fiber and the reinforcing short fiber into a predetermined length, and then opening at an appropriate stage. A method in which the fibers are mixed while being woven and laminated on a belt by air.

The material of the decorative film used in the present invention (regardless of the absolute value of its thickness, and usually means thinner than the above-mentioned "sheet") is the thermoplastic resin used for the above-mentioned sheet. It is appropriately selected depending on the adhesiveness to the resin and other required qualities, and in addition to those exemplified in the section of the thermoplastic resin, polymethyl methacrylate, polyacrylonitrile-ethylene-styrene copolymer, and the like are suitably used.

In the method for producing a surface-decorated molded product according to the present invention,
First, a decorative film is coated on a sheet in which reinforcing short fibers are oriented substantially randomly in the plastic resin. in this case,
In order to easily cover the decorative film, the decorative film is coated at a stage where the decorative film is formed into a sheet before being formed into a shape to be molded.

Next, at least a part of the sheet is heated and shaped in a stepwise manner while being fused with the decorative film. At this time, for example, a portion having a small radius of curvature, such as a corner portion of a molded product, is preferentially heated and shaped by roll forming or a shaping block, and a flat portion is heated and shaped so that the decorative film does not float. I do. In this case, the whole sheet does not need to be heated, although it depends on the shape of the molded article.

(Function) In the method for producing a surface-decorated molded product according to the present invention, a sheet in which reinforcing short fibers are substantially randomly oriented in a thermoplastic resin is coated with a decorative film, and the decorative film is coated. While at least a part of the sheet is fused with the decorative film while being heated and shaped in a stepwise manner, the above-mentioned sheet is such that the reinforcing short fibers are substantially randomly oriented in the thermoplastic resin. Since the anisotropy of the mechanical properties is small and the film has sufficient flexibility, after covering the decorative film, for example, a portion of the molded product having a small radius of curvature is preferentially combined with the sheet. By fusing the decorative film, it is possible to easily decorate the sheet surface, and to obtain a surface decorative molded product having less directional mechanical properties.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. (Example) Short fiber made of carbon fiber (fiber length 1 to 40)
mm, a fiber diameter of 10 μm) and a thermoplastic resin short fiber obtained by shortening polyethylene terephthalate fiber are blown by air to be deposited in layers, and heated and pressed at a temperature not lower than the softening temperature (140 ° C.) of the polyethylene terephthalate fiber. Thus, a sheet (1.7 mm thick) in which carbon fibers were randomly oriented in polyethylene terephthalate was obtained.

The sheet is cut in various directions, and the tensile modulus in the direction in which the tensile modulus is maximized is 110 MPa (E).
_max ) and the tensile modulus (E _min ) in the direction in which the tensile modulus was minimized were 70 MPa.

Next, a polymethyl methacrylate film (thickness: 0.1 mm) is laminated on the sheet, and corners of the eaves gutter 1 are formed so as to have substantially the same shape as the eaves gutter 1 to be formed shown in FIG. (1a, 1b, 1c, 1
The eaves gutter 1 was obtained by roll forming while heating only the positions corresponding to d, 1e, 1f, 1g, 1h, 1i, and 1j.

Comparative Example A sheet in which carbon fibers were randomly oriented in polyethylene terephthalate was formed by roll forming the shape of the eaves gutter 1 shown in FIG. 1 and then laminated with a polymethyl methacrylate film. In the same manner as in the example, eaves gutter 1 was obtained.

In Examples and Comparative Examples, evaluations were made on the ease of molding and the production efficiency, and the results are shown in Table 1.

In order to evaluate the applicability to thin products, the moldability was evaluated for sheet thicknesses of 1.7 mm and 1.2 mm, and the results are shown in Table 1.

[0021]

[Table 1]

[0022]

According to the method for producing a composite material of the present invention as described above, it is possible to easily decorate the sheet surface and obtain a surface-decorated molded product having less mechanical property directionality. Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an eaves gutter formed in an example.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 9:00 B29C 67/14 G F term (Reference) 4F100 AD11 AH012 AK01A AK25 AK42 AT00B BA02 CA23A DG01 DG01A DG01H EC032 EJ17 EJ42 EJ422 GB07 HB00B JA20A JB16A JK01 JL01 JL02 4F205 AC03 AD09 HA36 HB13 HT01 HT11 HT16 HT26 4F208 AC03 AD09 AG03 MB01 MB19 MG07 MG11 MH06 MK20

Claims (1)

[Claims] A decorative film is coated on a sheet in which reinforcing short fibers are substantially randomly oriented in a thermoplastic resin, and at least a part of the sheet coated with the decorative film is fused with the decorative film. A method for producing a surface-decorated molded product, comprising heating and shaping step by step.