JP2014054798A - Method for producing fiber-reinforced thermoplastic resin-molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fiber-reinforced thermoplastic resin-molded article, in which a discontinuous fiber-reinforced thermoplastic resin-molded article is reinforced more easily by a reinforcing material.SOLUTION: The fiber-reinforced thermoplastic resin-molded article includes: the discontinuous fiber-reinforced thermoplastic resin-molded article (A) containing a discontinuous fiber and a thermoplastic resin composition; and a tape-shaped product (B) comprising a continuous reinforcing fiber and the thermoplastic resin composition. The discontinuous fiber-reinforced thermoplastic resin-molded article (A) and the tape-shaped product (B) are melt-bonded integrally to each other while heating/melting at least one thereof. At that time, since the flowability of a discontinuous fiber-reinforced thermoplastic resin is utilized, the fiber-reinforced thermoplastic resin-molded article having the physical properties close to the reinforcing fiber-derived physical properties and a complicated shape can be obtained by such a simple operation that at least one of the discontinuous fiber-reinforced thermoplastic resin-molded article and the tape-shaped product is heated/melt when both thereof are melt-integrated with each other.

Description

  The present invention relates to a method for producing a fiber reinforced thermoplastic resin molded article that reinforces a discontinuous fiber reinforced thermoplastic resin molded article composed of discontinuous fibers and a thermoplastic resin composition.

  It is known that fiber reinforced thermoplastic resin molded products have the advantage of being able to be molded in a short time compared to composite materials that use thermosetting resins as matrix resins when thermoplastic resins are used as matrix resins. . On the other hand, fiber reinforced thermoplastic resin consisting of discontinuous fibers is characterized by excellent shapeability, such as being able to mold complex shapes, but mechanical strength compared to composite materials consisting of continuous fibers Is low, and the performance of the molded product tends to be low. Therefore, there has been a demand for a simple method in which after a molded article having a complicated shape is formed with a discontinuous fiber material, partial reinforcement with a continuous fiber material is performed later on a portion requiring high strength.

For example, in JP-A-7-9589 (Patent Document 1), at least the surface of a reinforcing material composed of reinforcing continuous fibers and a thermoplastic resin is heated and melted, and a thermoplastic resin used for the reinforcing material is used. Disclosed is a method in which a composition to be reinforced comprising a compatible thermoplastic resin and reinforcing fiber is heated and melted, and the reinforced material is supplied to the heated and melted reinforcing material to integrate them. ing. In this method, it is necessary to heat the material to be reinforced, and it is necessary to heat and melt the reinforcing material composed of the thermoplastic resin and the reinforcing fiber by an extruder or the like, and it is necessary to further press-mold, and there is a problem that the operation becomes complicated. there were.
Under such circumstances, a simpler method for producing a discontinuous fiber reinforced thermoplastic resin molded article and a reinforcing method have been desired.

Japanese Patent Laid-Open No. 7-9589

  The problem to be solved by the present invention is to provide a method for producing a fiber reinforced thermoplastic resin molded product in which a discontinuous fiber reinforced thermoplastic resin molded product is more easily reinforced by a reinforcing material.

  The method for producing a fiber reinforced thermoplastic resin molded article according to the present invention includes a discontinuous fiber reinforced thermoplastic resin molded article containing discontinuous fibers and a thermoplastic resin composition, and a tape comprising the continuous reinforced fibers and the thermoplastic resin composition. And at least one of the discontinuous fiber reinforced thermoplastic resin molded product and the tape-like product is melted and joined together while being heated and melted.

  Here, the point to be noted in the present invention is that the base material of the fiber reinforced thermoplastic resin molded product is inherently formable compared to the base material of the fiber reinforced resin molded product having a thermosetting resin as a matrix. It is a discontinuous fiber reinforced thermoplastic resin molded product which is excellent in physical properties but is inferior in physical properties. It is important to obtain a fiber reinforced resin molded product having a complicated shape by utilizing the high formability which is an advantage of this discontinuous fiber reinforced thermoplastic resin molded product. The present invention provides a continuous fiber, a thermoplastic composition, and a continuous fiber, as a composite product of a discontinuous fiber reinforced thermoplastic resin molded product molded into a complicated shape with a reinforced fiber. As a reinforcing material, the tape-like material is melted and integrated into a discontinuous fiber reinforced thermoplastic resin molded product.

  According to a preferred aspect of the present invention, the tape-like product has a thickness of 30 to 300 μm, a width of 5 to 75 mm, and a volume content of the continuous reinforcing fibers of 20 to 70%. Preferably, the discontinuous fiber reinforced thermoplastic resin molded product is cut into an average length of 5 to 100 mm and dispersed in a quasi-isotropic manner, with the tape-like material comprising the continuous reinforcing fiber and the thermoplastic resin composition. It has a configuration. More preferably, at least one of the discontinuous fiber reinforced thermoplastic resin molded article and the tape-like product contains carbon fibers.

  It is preferable that the thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded article is a thermoplastic resin composition having compatibility with the thermoplastic resin composition contained in the tape-like product. Both the thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded article and the thermoplastic resin composition contained in the tape-like product may be a polypropylene resin composition or a polyamide resin composition. Further preferred.

  According to the present invention, when forming a discontinuous fiber reinforced thermoplastic resin molded product by a method such as press molding, the fluidity of the discontinuous fiber reinforced thermoplastic resin is maintained, and the discontinuous fiber is evenly dispersed throughout. A high-quality discontinuous fiber reinforced thermoplastic resin molded product is obtained. When, as described above, the discontinuous fiber reinforced thermoplastic resin molded article thus obtained and the tape-like material composed of a reinforcing material containing a continuous reinforcing fiber and a thermoplastic resin composition as a reinforcing material are fused and integrated as described above, Complex shaped fiber reinforced thermoplastic resin molded product with physical properties close to those derived from reinforced fiber by simple operation of heating and melting at least one of discontinuous fiber reinforced thermoplastic resin molded product and tape-like product Can be obtained.

It is a perspective view which shows the 1st example of a discontinuous fiber reinforced thermoplastic resin molded product. It is a perspective view which shows the 1st example of the discontinuous fiber reinforcement | strengthening thermoplastic resin molded product reinforced with the tape-like thing which consists of a continuous reinforcement fiber and a thermoplastic resin. It is a perspective view which shows the 2nd example of a discontinuous fiber reinforced thermoplastic resin molded product. It is a perspective view which shows the 2nd example of the discontinuous fiber reinforcement | strengthening thermoplastic resin molded product reinforced with the tape-shaped object which consists of a continuous reinforcement fiber and a thermoplastic resin. It is a perspective view which shows the 3rd example of a discontinuous fiber reinforced thermoplastic resin molded product. It is a perspective view which shows the 3rd example of the discontinuous fiber reinforcement | strengthening thermoplastic resin molded product reinforced with the tape-like thing which consists of a continuous reinforcement fiber and a thermoplastic resin. It is a perspective view which shows the 4th example of the discontinuous fiber reinforcement | strengthening thermoplastic resin molded product reinforced with the tape-shaped object which consists of a continuous reinforcement fiber and a thermoplastic resin.

  FIG. 1 shows an example of a discontinuous fiber reinforced thermoplastic resin molded article. The discontinuous fiber reinforced thermoplastic resin molded product is a thermoplastic resin molded product containing discontinuous reinforcing fibers. The discontinuous reinforcing fiber means a fiber in which the reinforcing fiber is interrupted in the molded product. A thermoplastic resin material containing discontinuous reinforcing fibers is inferior in physical properties to a thermoplastic resin material containing continuous reinforcing fibers, but is excellent in fluidity and shapeability during molding such as press molding.

  The volume content of reinforcing fiber in the discontinuous fiber reinforced thermoplastic resin molded product (measured according to JIS K 7052 or JIS K 7075) is preferably 20 to 70%. When the volume content of the reinforcing fibers is 20% or more, the physical properties derived from the reinforcing fibers can be exhibited in the discontinuous fiber reinforced thermoplastic resin molded article. When the volume content of the reinforcing fiber is 70% or less, the flowability of the discontinuous fiber reinforced thermoplastic resin is maintained when the discontinuous fiber reinforced thermoplastic resin molded product is molded by a method such as press molding. A molded product having a simple shape can be obtained.

  In the discontinuous fiber reinforced thermoplastic resin molded product, the reinforcing fibers contained may be dispersed in the form of short filaments that are opened one by one, or are dispersed in a bundle consisting of a large number of reinforcing fiber filaments. May be. The opened filaments and bundles of fibers are preferably dispersed pseudo-isotropically randomly in the thermoplastic resin composition. Here, the random dispersion means a bundle of a large number of reinforcing fiber filaments, a state in which the reinforcing fibers are dispersed without having a specific direction, or a specific direction as individual reinforcing fiber filaments. It includes any of the states that are dispersed. The length of the reinforcing fiber is preferably 5 to 100 mm. When the length of the reinforcing fiber is 5 mm or more, the physical properties of the discontinuous fiber reinforced thermoplastic resin molded article are excellent. When the length of the reinforcing fiber is 100 mm or less, the discontinuous fiber reinforced thermoplastic resin molded article is pressed. Excellent fluidity.

As an example of a specific form of a thermoplastic resin composition containing discontinuous reinforcing fibers, a thickness of 30 to 300 μm and a width of 5 to 75 mm in which continuous reinforcing fibers are aligned in one direction and impregnated with the thermoplastic resin composition The tape-shaped material is cut to a length of 5 to 100 mm to obtain a chopped tape, and the chopped tape is randomly dispersed in the mold, and in this state, the mold is heated, pressed and cooled to be molded by hot press molding. Can be mentioned. The thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded product is not particularly limited, polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, ABS resin, acrylic resin, Polyamides such as vinyl chloride and polyamide 6, polycarbonate, polyphenylene ether, polyether sulfone, polysulfone, polyether imide, polyketone, polyether ketone, polyether ether ketone and the like can be used. Moreover, the modified body of these each resin may be used, and multiple types of resin may be blended and used. Further, the thermoplastic resin composition may contain various additives, fillers, colorants and the like.
Examples of the reinforcing fiber contained in the discontinuous fiber reinforced thermoplastic resin molded article include glass fiber, carbon fiber, and aramid fiber.

  In order to reinforce the discontinuous fiber reinforced thermoplastic resin molded product, a tape-like material composed of continuous reinforced fibers and a thermoplastic resin composition is used. The continuous fiber refers to a continuous piece of tape-like material composed of the continuous reinforcing fiber and the thermoplastic resin composition. A tape-like material composed of continuous reinforcing fibers and a thermoplastic resin composition contains such continuous fibers, and therefore has excellent physical properties. As a specific structure of a tape-like material composed of continuous reinforcing fibers and a thermoplastic resin composition, there is a composition in which continuous reinforcing fibers are aligned in one direction and impregnated with a thermoplastic resin composition.

  It is preferable that the volume content of the reinforcing fiber in the tape-shaped product composed of the continuous reinforcing fiber and the thermoplastic resin composition is 20 to 70%. When the volume content of the reinforcing fibers is 20% or more, the physical properties derived from the reinforcing fibers can be exhibited in a tape-like material made of the continuous reinforcing fibers and the thermoplastic resin composition. When the volume content of the reinforcing fiber is 70% or less, it becomes easy to integrate the tape-like material composed of the continuous reinforcing fiber and the thermoplastic resin composition into the discontinuous fiber reinforced thermoplastic resin molded article, and the reinforcing work is facilitated. It becomes easy.

  The thickness of the tape-like material composed of the continuous reinforcing fiber and the thermoplastic resin composition is preferably 30 to 300 μm. When the thickness of the tape-like product is 30 μm or more, strength and rigidity can be given to the tape, and it becomes easy to perform an operation of laminating and integrating the tape-like product with the discontinuous fiber reinforced thermoplastic resin molded product. When the thickness of the tape-like product is 300 μm or less, the tape itself can be wound around a bobbin or the like, and the operation of laminating the tape-like product on the discontinuous fiber reinforced thermoplastic resin molded product can be easily performed.

The width of the tape-like material composed of continuous reinforcing fibers and the thermoplastic resin composition is preferably 5 to 75 mm. When the width of the tape-like material is 5 mm or more, the tape-like material can be easily laminated on the discontinuous fiber reinforced thermoplastic resin molded product in a short time. When the width of the tape-like material is 75 mm or less, it is possible to laminate the fine portions of the discontinuous fiber reinforced thermoplastic resin molded product.

  The thermoplastic resin composition and the reinforcing fiber contained in the tape-shaped material comprising the continuous reinforcing fiber and the thermoplastic resin composition are selected from, for example, those exemplified for the above-mentioned discontinuous fiber reinforced thermoplastic resin molded article. it can. The thermoplastic resin composition and the reinforcing fiber contained in the tape-like product comprising the continuous reinforcing fiber and the thermoplastic resin composition and the discontinuous fiber reinforced thermoplastic resin molded product are the same or different. May be.

  As a method of reinforcing a discontinuous fiber reinforced thermoplastic resin molded article with a tape-like material composed of continuous reinforcing fibers and a thermoplastic resin composition, the tape-like portion of the discontinuous fiber reinforced thermoplastic resin molded article is to be reinforced. Arrange things. Then, the tape-like material is pressed while being heated using an iron or a heating mold. At this time, the thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded article and / or the thermoplastic resin composition contained in the tape-like material composed of the continuous reinforced fiber and the thermoplastic resin composition is melted. Let Then, after heating using heating means, such as an iron prepared separately, it cools, and the discontinuous fiber reinforced thermoplastic resin molded product and the tape-like thing which consists of continuous reinforced fiber and a thermoplastic resin are integrated.

  When reinforcing a discontinuous fiber reinforced thermoplastic resin molded article with a tape-like material comprising continuous reinforced fibers and a thermoplastic resin composition, an iron heated above the melting point or glass transition temperature of the thermoplastic resin composition. For example, it is preferable to integrate while pressing. Thereafter, it is preferable to wait until the portion falls below the melting point or glass transition temperature of the thermoplastic resin composition. In the middle of cooling, a separate non-heated iron may be prepared and pressed.

  In view of the reinforcing effect when a discontinuous fiber reinforced thermoplastic resin molded product is integrated with a tape-like material composed of continuous reinforced fiber and a thermoplastic resin composition, the thermoplasticity contained in the discontinuous fiber reinforced thermoplastic resin molded product It is preferable that the resin composition is compatible with the thermoplastic resin composition contained in the tape-shaped material composed of the continuous reinforcing fiber and the thermoplastic resin composition.

  When a tape-like material composed of continuous reinforcing fibers and a thermoplastic resin composition is disposed in a discontinuous fiber reinforced thermoplastic resin molded article, the tape angle can be selected from any angle. Further, a gap may be provided between the tapes or they may be overlapped. The tape-like product composed of continuous reinforcing fibers and thermoplastic resin may cover the entire discontinuous fiber reinforced thermoplastic resin molded article or may partially cover it.

In this way, discontinuous fiber reinforced thermoplastic resin molded products reinforced with tapes composed of continuous reinforcing fibers and thermoplastic resin compositions have significantly higher mechanical properties such as strength and elastic modulus than before being reinforced. improves.
Hereinafter, the present invention will be described more specifically with reference to examples.

As the discontinuous fiber reinforced thermoplastic resin molded product A, one obtained by the following method was used.
First, a reinforcing fiber was a carbon fiber having a diameter of 7 μm, a tape-like product having a thickness of 150 μm, a width of 15 mm, and a volume content of the carbon fiber of 45%, in which the continuous carbon fiber was impregnated with polypropylene was obtained. This was cut into a length of 30 mm to obtain a plate-like material having a width of 55 mm, a length of 380 mm, and a thickness of 8 mm dispersed pseudo-isotropically. This plate was preheated for 6 minutes with an infrared heater heated to 270 ° C., placed on a mold heated to 130 ° C., and held at a pressure of 20 MPa for 1 minute to obtain a molded product.

  As a tape-like product B composed of continuous reinforcing fibers and a thermoplastic resin composition, the same thickness as the tape-like product used in the production of the discontinuous fiber-reinforced thermoplastic resin molded product A is 150 μm, a width of 15 mm, and a continuous carbon fiber. A tape-like material having a volume content of 45% was used.

Example 1
As the discontinuous fiber reinforced thermoplastic resin molded product A, a molded product having the shape shown in FIG. 1 was used. That is, the cross section rises by tilting left and right at the center in the width direction, and the molded product main body 1 in which each vertex is connected horizontally by a straight line, and extends horizontally horizontally from the left and right lower ends of the molded product main body 1. The left and right lower end edges 2 are formed to have an elongated shape in the depth direction. At this time, in this example, the entire width W of the discontinuous fiber reinforced thermoplastic resin molded product A was 100 mm, the lateral width S1 of the top surface portion 3 was 45 mm, and the depth length L was 405 mm. As shown in FIG. 2, a continuous fiber reinforced thermoplastic resin tape B having a length of 405 mm and a width of 15 mm is formed on the top surface portion 3 of the discontinuous fiber reinforced thermoplastic resin molded product A so that there is no gap between the tapes. The three were placed side by side. The continuous fiber reinforced thermoplastic resin tape B was pressed against the discontinuous fiber reinforced thermoplastic resin molded product A with an iron (not shown) heated to 210 ° C. while heating. Then, using a non-heated iron (not shown) prepared separately, it was cooled while pressed against the continuous fiber reinforced thermoplastic resin tape B, and reinforced with the continuous fiber reinforced thermoplastic resin tape B. A fiber-reinforced thermoplastic resin molded product mainly composed of the discontinuous fiber reinforced thermoplastic resin molded product A was obtained.

(Example 2)
As the discontinuous fiber reinforced thermoplastic resin molded product A, a molded product having a shape obtained by repeating the shape shown in FIG. 1 as shown in FIG. 3 was used. In each discontinuous fiber reinforced thermoplastic resin molded article A, a tape-like shape made of continuous fiber reinforced thermoplastic resin having a width of 15 mm and a length of 405 mm is provided on each upper surface of the left and right upper edge portions 4 having a lateral width S2 of 15 mm as shown in FIG. Object B was mounted one by one. In this state, the continuous fiber reinforced thermoplastic resin tape B was pressed against the discontinuous fiber reinforced thermoplastic resin molded product A with an iron (not shown) heated to 210 ° C. while heating. Then, it cooled, pressing the continuous fiber reinforced thermoplastic resin tape-form B using the iron which is not prepared and which was not heated but was prepared. This operation was repeated 5 times, and five layers of tape-like material B made of continuous reinforcing fibers and thermoplastic resin were laminated on the edge portion of the discontinuous fiber reinforced thermoplastic resin molded product A.

(Example 3)
Two discontinuous fiber reinforced thermoplastic resin molded products A used in Example 1 were welded by abutting the left and right upper and lower edges 4 and 2 using a vibration welding machine. A continuous fiber reinforced thermoplastic resin molded article A ′ was obtained. In this pipe-shaped discontinuous fiber reinforced thermoplastic resin molded product A ′, as shown in FIG. 6, a continuous fiber reinforced thermoplastic resin tape having a width of 45 mm and a length of 405 mm on the upper surface of the left and right lower edge portions 2 of the upper half. One product B was placed and pressed against the discontinuous fiber reinforced thermoplastic resin molded article A ′ while heating the continuous fiber reinforced thermoplastic resin tape B with an iron (not shown) heated to 210 ° C. Then, it cooled, pressing the continuous fiber reinforced thermoplastic resin tape-form B using the iron which is not prepared and which was not heated but was prepared. Similarly, two continuous fiber reinforced thermoplastic resin tapes B are arranged on the surface portion of the left and right rising parts 5 in the upper half, and three are arranged on the upper surface of the top surface part 3 to form a continuous fiber reinforced thermoplastic resin tape. Object B was integrated. This operation was also performed on the lower half of the pipe-shaped object.

Next, as shown in FIG. 7, along the upper surface of the upper half front end portion of the pipe-shaped discontinuous fiber reinforced thermoplastic resin molded product A ′, it is orthogonal to the continuous fiber reinforced thermoplastic resin tape B. Then, a continuous fiber reinforced thermoplastic resin tape B having a length of 135 mm made of continuous reinforced fibers and a thermoplastic resin was placed while being bent, and the continuous fiber reinforced heat was heated with an iron (not shown) heated to 210 ° C. While the plastic resin tape B was heated, it was pressed against the discontinuous fiber reinforced thermoplastic resin molded product A. Then, it cooled, pressing the continuous fiber reinforced thermoplastic resin tape-form B using the iron which is not prepared and which was not heated but was prepared. Next, another continuous fiber reinforced thermoplastic resin tape B was overlapped with the previous continuous fiber reinforced thermoplastic resin tape B by 2 mm and integrated in the same manner. This operation was repeated to laminate a total of 31 tapes. A similar operation was carried out on the lower half of the pipe-shaped object.

  According to the production methods of Examples 1 to 3, discontinuous fibers are used in spite of the simple operation of heating and melting at least one of the discontinuous fiber reinforced thermoplastic resin molded article and the tape-like product. When the reinforced thermoplastic resin molded product and the tape-like product made of continuous reinforcing fiber and thermoplastic resin are fused and integrated, the fluidity of the continuous fiber reinforced thermoplastic resin is used, so even if the shape is complicated In addition, it was possible to obtain a fiber-reinforced thermoplastic resin molded article having physical properties close to those derived from the reinforcing fibers and having a desired strength.

DESCRIPTION OF SYMBOLS 1 Molded product main body 2 Left and right lower edge part 3 Top surface part 4 Left and right upper edge part 5 Left and right rising part A, A 'Discontinuous fiber reinforced thermoplastic resin molded product B Continuous fiber reinforced thermoplastic resin tape (tape)
L Depth length W of discontinuous fiber reinforced thermoplastic resin molded product W Width of discontinuous fiber reinforced thermoplastic resin molded product S1 Width of top surface of discontinuous fiber reinforced thermoplastic resin molded product S2 Discontinuous fiber reinforced thermoplastic resin molded product Horizontal width of the left and right and upper and lower edges of the product

Claims (6)

  A discontinuous fiber reinforced thermoplastic resin molded article comprising a discontinuous fiber and a thermoplastic resin composition, and a tape-shaped article comprising the continuous reinforcing fiber and the thermoplastic resin composition, the discontinuous fiber reinforced thermoplastic resin molded article. And a method for producing a fiber-reinforced thermoplastic resin molded article in which at least one of the tape-like product is melted and integrated by heating and melting.   The method for producing a fiber-reinforced thermoplastic resin molded article according to claim 1, wherein the tape-like product has a thickness of 30 to 300 µm, a width of 5 to 75 mm, and a volume content of the continuous reinforcing fibers of 20 to 70%. The discontinuous fiber reinforced thermoplastic resin molded article is
The tape-like product comprising the continuous reinforcing fiber and the thermoplastic resin composition is cut into an average length of 5 to 100 mm, and has a configuration in which the tape is isotropically dispersed. A method for producing a fiber-reinforced thermoplastic resin molded article.   The method for producing a fiber-reinforced thermoplastic resin molded product according to any one of claims 1 to 3, wherein at least one of the discontinuous fiber reinforced thermoplastic resin molded product and the tape-like product contains carbon fibers.   The thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded article is a thermoplastic resin composition having compatibility with the thermoplastic resin composition contained in the tape-like product. A method for producing a fiber-reinforced thermoplastic resin molded article according to any one of the above.   The thermoplastic resin composition contained in the discontinuous fiber reinforced thermoplastic resin molded article and the thermoplastic resin composition contained in the tape-like product are both a polypropylene resin composition or a polyamide resin composition. The manufacturing method of the fiber reinforced thermoplastic resin molded product of Claim 5.

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