JPH05269785A - Production of composite molded product - Google Patents

Abstract

PURPOSE:To produce a composite molded product by providing a coating layer excellent in appearance on the surface of a fiber reinforced thermoplastic resin molded object excellent in strength to strongly bond the same. CONSTITUTION:A sheet material 11 with glass content of 40wt.% is set to the movable mold 121 of a mold 12 and the surface thereof is heated to about 200 deg.C by an infrared heater 14 to be brought to a molten state. The mold 12 is closed and a thermoplastic resin melted at about 200 deg.C is injected in the cavity 122 of the mold to obtain a fiber reinforced resin composite panel 2 wherein the coating layer 22 composed of the thermoplastic resin is integrally provided to a molded object 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite molded article in which a coating layer having an excellent appearance is firmly adhered to the surface of a fiber-reinforced thermoplastic resin molded article having excellent strength.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a thermoplastic resin molded product reinforced with a fibrous reinforcing material, a fibrous reinforcing material and a thermoplastic resin are melt-kneaded in advance at the time of molding and injection molding to obtain a desired shape. Molding method, JP-A-58-3
As described in Japanese Patent No. 4292, Japanese Patent Publication No. 48-13714, and Japanese Patent Laid-Open No. 60-158228, a sheet-like thermoplastic resin material reinforced with a relatively long fibrous reinforcing material having a length of 5 mm or more, so-called A method of compression-molding a stampable sheet at a melting temperature of a thermoplastic resin is widely used. In the former case, the fibrous reinforcing material is cut and shortened during melt-kneading with the fibrous reinforcing material and the thermoplastic resin, and the length of the fibrous reinforcing material in the final molded product is usually 3 mm or less. Therefore, there is a problem that a sufficient reinforcing effect cannot be obtained. When the latter stampable sheet is used, the fiber is less damaged during compression molding, and the length of the fibrous reinforcing material in the final molded product can be increased, resulting in excellent strength and impact resistance. Although a molded product can be obtained, there is a problem that the fibrous reinforcing material is likely to stand out on the surface of the molded product and the appearance thereof is inferior.

In view of this problem, for example, as described in Japanese Patent Laid-Open No. 56-8239, a preformed portion made of a fibrous reinforcing material and a thermoplastic resin is formed in a part of the mold cavity. Molded, then 30 ° C than preformed part
A method has been proposed in which the thermoplastic resin heated to a high temperature is injected and filled into the voids inside the cavity to form the thermoplastic resin layer.

[0004]

However, in this method, since the surface of the preformed portion is in a cured state at the time of injection molding of the thermoplastic resin, the surface of the preformed portion is not cured with the thermoplastic resin layer provided thereon. There is a problem that the adhesiveness is not sufficient and the two are easily separated from each other. Further, during injection molding of the thermoplastic resin, the cured surface of the preformed portion is instantly pressed by the thermoplastic resin layer injected and filled into the voids inside the cavity, so that the fibers present in the surface area of the preformed portion The reinforcing material is not elastically recovered but is still pressed into the inside thereof, and there is a problem that it does not contribute to the adhesiveness with the thermoplastic resin layer.

The present invention solves the above-mentioned conventional problems, and a coating layer having an excellent appearance is provided on the surface of a fiber-reinforced thermoplastic resin molded article having excellent strength, and the molded article and the coating layer are provided thereon. The purpose of the present invention is to provide a method for producing a composite molded article in which the coating layer is firmly bonded to the coating layer.

[0006]

The invention of claim 1 of the present application is as follows.
Manufacture of a composite molded article in which a coating layer made of a second material containing a thermoplastic resin is integrally provided on at least a part of the surface of a molded body made of a first material containing a fibrous reinforcing material and a thermoplastic resin. In the method, at least a part of the surface of the molded body made of the first material is preheated to bring its surface region into a molten state, and a second material containing a molten thermoplastic resin is further formed thereon. It is a method for producing a composite molded article which is supplied to provide a coating layer.

In the present invention, the first material comprises a fibrous reinforcing material and a thermoplastic resin.

The thermoplastic resin may be any resin without particular limitation, and examples thereof include polyvinyl chloride, polyethylene, polypropylene, polyamide, polyester, polycarbonate, polyphenylene sulfide, and polyether ether ketone. Be done. The thermoplastic resin may contain additives, such as pigments, processing aids, antioxidants, and ultraviolet absorbers, which are usually used in molding and processing of thermoplastic resins, if necessary. Further, it may contain an inorganic filler such as talc or calcium carbonate.

As the fibrous reinforcing material, all fibers that can be used as a reinforcing material for thermoplastic resin such as glass fiber, carbon fiber, aramid fiber and metal fiber can be used, and the length thereof is 5 mm or more. preferable. If the length is less than 5 mm, it tends to be difficult to expect a sufficient reinforcing effect. The amount of the fibrous reinforcing material having a length to be blended in the thermoplastic resin is preferably 5 to 70% by weight. If it is less than 5% by weight, it is difficult to expect a sufficient reinforcing effect,
If it exceeds 70% by weight, the adhesiveness with the coating layer made of a thermoplastic resin tends to be lowered. Incidentally, the thermoplastic resin may appropriately contain a fibrous reinforcing material having a length of less than 5 mm. In this case, the total amount of the fibrous reinforcing material is preferably 70% by weight or less. If it exceeds 70% by weight, the adhesiveness with the coating layer made of a thermoplastic resin tends to be lowered.

In the present invention, the second material contains a thermoplastic resin and, if necessary, a short fibrous reinforcing material.

As the thermoplastic resin, any resin can be used without particular limitation, but it has a high compatibility with the thermoplastic resin in the first material and enhances the adhesiveness with the molded product made of the first material. Therefore, a resin having a melting temperature equal to or higher than that of the thermoplastic resin in the first material is preferable. Specific examples thereof include the same as above. The thermoplastic resin may also contain the same additives and inorganic fillers as described above.

As the short fibrous reinforcing material to be blended as necessary, the same fibrous reinforcing material having a length of less than 5 mm, preferably 3 mm or less can be used. 5 mm in length
In the above cases, the appearance of the molded product tends to be impaired. The length of the short fibrous reinforcing material of less than 5 mm means the length in the coating layer, and even if it is 5 mm or more when blended in the thermoplastic resin, it is kneaded with the thermoplastic resin during kneading. The length may be less than 5 mm, and the length in the coating layer may be less than 5 mm. The amount of the short fibrous reinforcing material blended in the thermoplastic resin is preferably 0 to 70% by weight. If the amount exceeds 70% by weight, not only the appearance of the molded product is impaired, but also the adhesiveness with the molded product made of the first material tends to deteriorate.

In the present invention, the molded body made of the first material is the first molded body containing the fibrous reinforcing material and the thermoplastic resin.
A material obtained by molding the above material into a sheet shape, a plate shape, a film shape or the like by an appropriate molding means such as compression molding is used.

In the present invention, as a method of preheating at least a part of the surface of the molded body to melt the thermoplastic resin in the surface region, the molded body is set in an open mold. In the method, the surface is heated to a temperature above the melting temperature of the thermoplastic resin by heating means such as hot air or an infrared heater, and the surface of the molded article is heated to above the melting temperature of the thermoplastic resin by a similar heating means. It is possible to adopt a method of setting the mold in a mold. The melting temperature of the thermoplastic resin or higher means that the viscosity of the thermoplastic resin measured according to the flow test method (reference test) of JIS K7210 is 3
It is tentatively set to be 00 to 100,000 poise, preferably 300 to 30,000 poise.

In the present invention, as the means for supplying the second material containing the molten thermoplastic resin onto the molded body made of the first material in which at least a part of the surface area is in the molten state, the surface area is Any means can be adopted as long as the second material containing the thermoplastic resin supplied thereon is in a molten state while the above is in a molten state. In molding or compression molding, a molded body made of the first material having at least a part of its surface region in a molten state is set in the mold cavity, and the molten thermoplastic resin is set in the mold cavity. Examples include a method of supplying the second material containing a resin.

The composite molded article produced according to the present invention can be used as a part or a product, such as an automobile exterior member, which is required to have high strength, high impact resistance, excellent physical properties, and good appearance. ..

According to the second aspect of the present invention, at least a part of the surface of the molded body made of the first material containing the fibrous reinforcing material and the thermoplastic resin is coated with the second material containing the thermoplastic resin. A method for producing a composite molded article in which a layer is integrally provided, wherein at least a part of the surface of a molded product made of the first material is preheated to melt the surface region and a part of the fiber reinforcement is exposed. A method for producing a composite molded article, which is in a state of being in a porous state or is in a porous state, is supplied with a second material containing a molten thermoplastic resin to form a coating layer.

Also in the present invention, as the molded body made of the first material, a molded body similar to the molded body used in the invention of claim 1 can be used, but preferably the fibrous reinforcing material and the heat A material obtained by molding the first material containing a plastic resin into a sheet shape, a plate shape, a film shape or the like by ordinary compression molding is used.

In the present invention, at least a part of the surface of the molded body made of the first material is preheated to melt the surface region, and the surface is partially exposed or porous of the fiber reinforcement. Need to As the heating method, the same method as described above can be adopted. The partially exposed state of the fiber reinforcing material refers to a state in which an end portion, an intermediate portion, or a part in the radial direction of the fibrous reinforcing material is protruded from the surface of the molded body, or a raised state in which the end portion is protruded. This state is, for example,
The fiber reinforced material in the state of being compressed in the thickness direction at the time of compression molding of the molded body appears as a result of elastic recovery due to melting of the thermoplastic resin in the heated portion and weakening of its restraining force. The porous state means a state in which a gap is formed between the fibrous reinforcing material and the thermoplastic resin. This state also appears as a result of elastic recovery of the fibrous reinforcing material as described above.

In the present invention, the first material, the second material, the method for melting the surface region of the molded body, the method for supplying the second material, the application, etc. are the same as those described above, and therefore detailed description thereof is omitted. ..

[0021]

According to the first aspect of the present invention, at least a part of the surface of the molded product made of the first material is heated in advance to bring the surface region into a molten state, and the molten thermoplastic resin is applied onto the surface region. By supplying the second material containing the coating layer to form the coating layer, the coating layer in a molten state is laminated on the surface of the molded body in a molten state, and the resin between the two is integrally cured so as to be fused to each other. Therefore, it is possible to manufacture a composite molded article in which the both are firmly bonded and the coating layer having an excellent appearance is firmly bonded to the surface of the molded article having excellent strength.

According to the second aspect of the present invention, at least a part of the surface of the molded body made of the first material is heated in advance to melt the surface area, thereby elastically recovering the fiber reinforcing material in the surface area. The surface of the fiber reinforced material is partially exposed or porous, and the second material containing the molten thermoplastic resin is supplied onto the surface of the fiber reinforced material to form a coating layer. On the surface of the molded body in a partially exposed state or porous state, a coating layer in a molten state is laminated, and the resin of the coating layer wraps a part of the fiber reinforced material exposed on the surface of the molded body or becomes a porous state Since the resin between them is integrally cured as it enters, the two are firmly adhered to each other, and the coating layer having an excellent appearance is firmly adhered to the surface of the molded product having excellent strength, and Delamination against impact applied It is possible to manufacture the door is not molded composite article.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Example 1 FIG. 1 is an explanatory diagram illustrating a process of manufacturing a fiber-reinforced composite plate according to an example of the present application. As a molded body made of the first material, a polypropylene resin (P
A sheet (P) was laminated and heat-impregnated (manufactured by Ube Nitto Kasei Co., Ltd .: trade name "Azudel", glass fiber content 40% by weight) was used. As the thermoplastic resin of the second material, pelletized PP (MFR: 6 g / 10 cm) was used.

As shown in FIG. 1 (a), a sheet 11 as a molded body made of the first material is set in the cavity 123 of the movable die 121 of the injection molding die 12 in the open state, and as a heating means. The exposed surface was heated to about 200 ° C. using the infrared heater 13 to bring the surface region into a molten state.

Next, the infrared heater 13 is removed, and FIG.
As shown in (b), the fixed mold 122 of the injection molding mold 12
Between the movable mold 121 and the movable mold 121, and inside the cavity 123,
Through a sprue 124 from a nozzle of an injection molding machine (not shown), pelletized PP as a second material was heated to about 200 ° C.
The coating material 14 which was heated and melted was poured onto the sheet 11 whose surface region was in a molten state.

Thereafter, the injection molding die 12 is opened, and as shown in FIG. 2, the fiber-reinforced resin composite plate 2 in which the coating layer 22 made of a thermoplastic resin is integrally provided on the molded body 21.
Got

The fiber-reinforced resin composite plate 2 thus obtained has one surface covered with a coating layer 22 having a good appearance and free of glass fiber protrusions, and is formed between the molded body 21 and the coating layer 22. No peeling was observed.

A test piece 2'as shown in FIG. 3 was cut out from the fiber-reinforced resin composite plate 2, and the crosshead speed was 5 mm /
A tensile test was performed under the condition of minutes. As a result, the maximum load (average value) was 83.9 kgf.

Example 2 A fiber-reinforced resin composite plate 2 was obtained in the same manner as in Example 1 except that hot air was used as the heating means instead of the infrared heater. The obtained fiber-reinforced resin composite plate 2 has one surface covered with a coating layer 22 having a good appearance without glass fibers protruding, and the molded body 21 and the coating layer 22.
No peeling between the two was observed. The fiber-reinforced resin composite plate 2 was subjected to a tensile test in the same manner as in Example 1. As a result, the maximum load (average value) was 69.4 kg.
It was f.

Comparative Example 1 A fiber-reinforced resin composite plate was obtained in the same manner as in Example 1 except that heating with an infrared heater was not performed (the surface temperature of the molded body was about 60 ° C.). A tensile test was performed on this fiber-reinforced resin composite plate in the same manner as in Example 1. As a result, the maximum load (average value) was 43.1 kgf.

Example 3 FIGS. 4 to 7 are explanatory views sequentially showing steps of producing a fiber-reinforced resin composite molded article of another example of the present invention.

As a first material, a sheet obtained by laminating a polypropylene (PP) resin material on a mat material in which continuous glass fiber strands are integrated by needling and impregnating it under heat and pressure (manufactured by Ube Nitto Kasei Co., Ltd .: trade name "Azudel") , With a glass fiber content of 40% by weight).

As the second material, PP (MFR: 6 g /
A resin mixture in which 20 parts by weight of glass fiber (average length: 0.75 mm) was added to 80 parts by weight of 10 cm) was used.

As shown in FIG. 4, both surfaces of the sheet 31 as the first material are heated to 200 ° C. by the infrared heater 32, and this is pressed by the press molding machine 33 as shown in FIG. 5 (a).
Placed on the lower mold 331, and as shown in FIG.
By closing 32 and compressing, a compression molded body 34 as shown in FIG. 6 was obtained.

Next, the compression molded body 34 is heated in its heating surface (not shown) with hot air at 300 ° C.,
The surface region was melted and the glass fiber in the surface region was elastically recovered to a raised state. Then compression molded body 34
As shown in FIG. 7A, was set on the convex portion 361a of the movable die 361 of the injection molding die 36.

Next, as shown in FIG. 7B, the space between the movable die 361 and the fixed die 362 of the injection molding die 36 is closed,
Through a nozzle of an injection molding machine (not shown), a coating material 35 obtained by heating and melting a resin mixture as a second material at 230 ° C. is passed through a sprue 364 so as to coat the surface 341 of the fluffed compression molded body. It was injected into the cavity 363. After that, the injection molding die 36 is opened, and as shown in FIG. 8, the second molding is performed on the surface of the molding 41 made of the first material.
A fiber-reinforced resin composite molded article 4 provided with a coating layer 42 made of the above material was obtained.

The outer surface of the fiber-reinforced resin composite molded article 4 is covered with a coating layer 42 which has a good appearance and is free of glass fibers, and peels between the molded body 41 and the coating layer 42. It was not recognized.

This fiber-reinforced resin composite molded article was placed on the floor with the coating layer side facing upward, and a worm-shaped falling weight of 2 kg was dropped from above the surface of the coating layer at a height of 4 m, and after dropping. A drop weight impact test was carried out to observe the state of the molded article. As a result, the molded body 4 of the fiber-reinforced resin composite molded product 4 shown in FIG.
No peeling between 1 and the coating layer 42 was observed.

Example 4 As a first material, a thick mat-like fiber material (manufactured by Nippon Steel Co., Ltd .: trade name) produced by a paper-making method from a dispersion treatment liquid of glass fibers having an average length of about 12 mm and powdered PP. A fiber-reinforced resin composite molded article 4 was obtained in the same manner as in Example 1 except that "Radlite" and glass fiber content 30% by weight) were used. The outer surface of the fiber-reinforced resin composite molded article 4 is
The glass fiber was covered with the coating layer 42 having a good appearance without protrusion, and peeling between the molded body 41 and the coating layer 42 was not observed. The fiber-reinforced resin composite molded article was subjected to a falling weight impact test in the same manner as in Example 1.
As a result, peeling between the molded product of the fiber-reinforced resin composite molded product and the coating layer was not observed.

Comparative Example 2 A fiber-reinforced resin composite molded article was obtained in the same manner as in Example 1 except that heating with an infrared heater was not performed (the surface temperature of the molded body was about 60 ° C.). The fiber-reinforced resin composite molded article was subjected to a falling weight impact test in the same manner as in Example 1.
As a result, peeling between the molded body of the fiber-reinforced resin composite molded article and the coating layer was observed.

Comparative Example 3 A fiber-reinforced resin composite molded article was obtained in the same manner as in Example 2 except that heating with an infrared heater was not performed (the surface temperature of the molded body was about 60 ° C.). The fiber-reinforced resin composite molded article was subjected to a falling weight impact test in the same manner as in Example 1.
As a result, peeling between the molded body of the fiber-reinforced resin composite molded article and the coating layer was observed.

[0042]

Since the invention of claim 1 of the present application has the above-mentioned constitution, it is possible to produce a composite molded article in which a coating layer having an excellent appearance is firmly adhered to the surface of a molded article having excellent strength. You can

According to the invention of claim 2 of the present application, since it is configured as described above, the coating layer having an excellent appearance is firmly adhered to the surface of the molded article having an excellent strength, and is resistant to the impact applied from the outside. On the other hand, it is possible to manufacture a composite molded article that does not undergo delamination.

[0044]

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating a process of manufacturing a composite plate according to an embodiment of the present invention, in which (a) is a cross-sectional view showing a state in which a molded body is set in a movable die and the surface thereof is heated, (B) is a sectional view showing a state in which the mold is closed and the coating material is injected into the cavity.

FIG. 2 is a cross-sectional view showing a composite plate manufactured according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a state in which a test piece is cut out from the obtained composite plate, (a) is a sectional view, and (b) is a front view.

FIG. 4 is a cross-sectional view showing a state in which both surfaces of the sheet are heated by heaters in the first step of producing a composite molded article according to another embodiment of the present invention.

5A and 5B are explanatory views showing a process for producing a composite molded article according to another embodiment of the present invention, FIG. 5A is a sectional view showing a state in which a sheet is placed on a lower mold, and FIG. It is sectional drawing which shows the state.

FIG. 6 is a vertical cross-sectional view showing a compression molded body obtained according to another embodiment of the present invention.

FIG. 7 is an explanatory view showing the latter half of the steps for producing a composite molded article according to another embodiment of the present invention, showing (a) a state in which the compression molded body is set in a movable die and the surface thereof is heated. A sectional view, (b) is a sectional view showing a state in which the mold is closed and the coating material is injected into the cavity.

FIG. 8 is a cross-sectional view showing a composite molded article manufactured according to an example of the present invention.

[Explanation of symbols]

 2 Composite plate 2'Test piece 4 Composite molded article 11,31 Sheet made of first material 12,36 Injection molding mold 13,32 Infrared heater 14,35 Coating material 21,41 Molded body 22,42 Second Layers made of the material 33 Press molding machine 34 Compression molded body 121,361 Moving mold 122,362 Fixed mold 123,363 Cavities 124,364 Sprue 331 Lower mold 332 Upper mold 341 Surface 361a Convex part

Claims (2)

[Claims] 1. A first device comprising a fibrous reinforcing material and a thermoplastic resin.
A method for producing a composite molded article, wherein a coating layer made of a second material containing a thermoplastic resin is integrally provided on at least a part of the surface of a molded article made of the material At least a part of the surface of is heated in advance to make the surface region in a molten state, and a second material containing a molten thermoplastic resin is supplied thereon to provide a coating layer. Molded article manufacturing method. 2. A first device comprising a fibrous reinforcing material and a thermoplastic resin.
A method for producing a composite molded article, wherein a coating layer made of a second material containing a thermoplastic resin is integrally provided on at least a part of the surface of a molded article made of the material A second material containing a molten thermoplastic resin on at least a part of the surface of the fiber which has been heated in advance to melt the surface region of the fiber reinforcement in a partially exposed state or a porous state. Is provided to provide a coating layer.