JPH10235708A - Production of composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a composite material which can be molded stably, is protected from the bending and breakage of a core material, has no dispersion of mechanical properties, and can be used appropriately for a trough. SOLUTION: Only part of a core material 2 consisting of a strip in which short fibers 21 oriented almost randomly are fixed with the first thermoplastic resin 22 is heated at a temperature of the softening temperature of the resin 22 or above and at a temperature where the short fibers 21 can be held or below to be formed nearly in a shape to be molded, and the second thermoplastic resin 3 is applied to the periphery of the core material 2 at a temperature lower than the melting point of the first resin 22.

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 material comprising a core and a thermoplastic resin covering the periphery of the core.

[0002]

2. Description of the Related Art Conventionally, composite materials comprising a core material such as a metal plate and a sheet and a thermoplastic resin covering the periphery of the core material have been widely used for eaves gutters and the like. For example, Japanese Unexamined Patent Publication No.
No. 33660, Japanese Utility Model Publication No. 61-43873,
Japanese Utility Model Publication No. Sho 61-27397 describes an eaves gutter manufactured from a composite material comprising a metal plate and a thermoplastic resin covering the periphery of the metal plate. The method for producing such a composite material generally uses a crosshead mold to extrude the molten thermoplastic resin around the core material passing through the mold, and to apply the thermoplastic resin around the core material. It is to be coated.

[0003] For example, Japanese Patent Publication No. 6-98691 discloses that a core material is a prepreg sheet in which many parallel long fibers are fixed with a thermoplastic resin (thermoplastic fixing material), and the same type of thermoplastic fixing material is used. A method for producing a composite material in which a core material is coated with a thermoplastic resin is described. Also, Tokuho 7-1
No. 10514 discloses a method for manufacturing an eaves gutter in which a prepreg sheet is used as a core material, and a composite material in which the core material is coated with a thermoplastic resin of the same type as the thermoplastic fixing material is formed into an eaves gutter shape. I have.

On the other hand, a normal eaves gutter is disclosed in Japanese Utility Model Publication No. 60-800.
As described in Japanese Patent Publication No. 4 (1994), a thermoplastic resin such as a vinyl chloride resin or a metal molded into an eaves gutter shape is often used.

[0005] However, the eaves gutter obtained by molding the above-mentioned thermoplastic resin into an eaves gutter shape, if it is used by attaching it to the eaves tip, is directly irradiated with sunlight and becomes high temperature, and softens or expands. Therefore, there is a problem that the eaves gutter is deformed such as being bent or bent and cracks are generated.

[0006] An eaves gutter formed of metal in the shape of an eaves gutter does not deform but has a problem that it is easily rusted. Also, an eaves gutter made of a composite material comprising a core material made of a metal plate and a thermoplastic resin covering the periphery of the core material has good heat resistance, has a small expansion and contraction, and is hardly rusted. Since the metal is exposed on the surface, there is a problem that the exposed portion rusts.

Further, a prepreg sheet in which long fibers are fixed with a fixing thermoplastic resin is used as a core material, and an eave manufactured by a composite material in which the core material is coated with a thermoplastic resin of the same type as the fixing thermoplastic resin. The gutter is very preferable because it has good heat resistance, small expansion and contraction, and is hardly rusted, but has a problem that it is expensive. Therefore, a belt-like body in which inexpensive short fibers are fixed with a fixing thermoplastic resin (first thermoplastic resin) is used as a core material, and a second thermoplastic resin having a melting point lower than that of the first thermoplastic resin is used. When the core material was covered, an inexpensive composite material having good heat resistance was obtained.

[0008]

However, when the composite material is shaped into an irregular shape such as an eaves gutter, for example, the core material is shaped in advance into a shape to be substantially shaped, and The core material is coated around the core material with the thermoplastic resin (2). When the core material is previously formed into a shape to be substantially molded, the core material is generally formed by roll forming or a shaping block. However, it is necessary to heat the core material in advance so as not to cause burrowing or destruction. Then, the first thermoplastic resin is softened, and the force for holding the fibers is weakened. As a result, the fibers are oriented in the thickness direction at the time of shaping, and the thickness of the core material becomes wider than a predetermined thickness, or becomes longer. There were problems such as that the mechanical properties in the axial direction were lower than those in the thickness direction.

The present invention solves the above-mentioned problems and provides a composite material which can be formed stably, does not cause burrowing or destruction of the core material, and does not vary in mechanical properties, and can be suitably used as an eaves gutter. It is to provide a manufacturing method.

[0010]

According to the present invention, there is provided a method of manufacturing a composite material, comprising the steps of: forming a core material comprising a belt-like body in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin; Is heated to a temperature equal to or higher than the softening point of the first thermoplastic resin and equal to or lower than a temperature at which the short fibers can be retained, and shaped into a shape to be substantially molded, and at a temperature lower than the melting point of the first thermoplastic resin, 2 is characterized in that the thermoplastic resin is coated around the core material.

As the short fibers used in the present invention, any fibers can be used as long as they can withstand the molding temperature of the thermoplastic resin, but inorganic fibers such as carbon fibers, metal fibers, glass fibers, Kepler, and cotton fibers. Organic fibers and the like can be suitably used. The diameter and length of the short fiber are appropriately selected according to the required performance of the core material.
100 mm and a diameter of 5 to 50 μm are often used.

The first thermoplastic resin and the second thermoplastic resin used in the present invention can be fused together, and the moldable temperature of the second thermoplastic resin is lower than that of the first thermoplastic resin. The first thermoplastic resin is not particularly limited as long as it is, for example, an acrylic resin, polyethylene terephthalate, nylon or the like is preferably used.
As the thermoplastic resin, for example, vinyl chloride resins, acrylic resins, and copolymers of vinyl chloride and other monomers, copolymers of acrylic monomers and other monomers, and the like are preferably used. .

The method for producing the core material is not particularly limited, and the belt-like body in which the short fibers oriented substantially randomly are fixed with the first thermoplastic resin by a powder impregnation method, a liquid impregnation method, or the like. Although it is possible to obtain, it is preferable to make the first thermoplastic resin into a short fiber form, mix the short thermoplastic fiber with the short fiber by air, stirring or the like, and then heat and pressurize, because the production is easy.

(Action) In the method for producing a composite material according to the present invention, a core material composed of a belt-like body in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin is used. Is heated to a temperature not lower than the softening point of the thermoplastic resin and not higher than the temperature at which the short fibers can be retained, shaped into a shape to be substantially molded, and formed at a temperature lower than the melting point of the first thermoplastic resin. Since the core material is covered with the thermoplastic resin, the core material is passed through a crosshead die, for example, and the second thermoplastic resin heated and melted at a molding temperature is extruded around the core material. When the composite material is manufactured by the method, the short fibers fixed by the first thermoplastic resin do not fall apart, and the composite material obtained by fusing the second thermoplastic resin to the first thermoplastic fixing material. Not only becomes stable, but also can be formed stably, and the core material does not burrow or break , There is no possibility that the mechanical properties varies.

Further, the composite material obtained by the present invention comprises a core material and a second thermoplastic resin covering the periphery of the core material, and furthermore, as described above, the short fibers are separated. Therefore, if this composite material is used as an eaves gutter, the eaves gutter manufactured from a composite material in which a conventional prepreg sheet is used as a core material and this core material is coated with the same thermoplastic resin as the first thermoplastic resin is used. Similarly, heat resistance is good, expansion and contraction is small,
Extremely preferable because it does not easily rust. Therefore, forming this composite material into an eaves gutter shape results in an ideal eaves gutter.

[0016]

Embodiments of the present invention will be described below in more detail with reference to the drawings. 1A and 1B show an example of a composite material obtained by the present invention. FIG. 1A is a partially cutaway perspective view of the composite material, and FIG. 1B is a perspective view showing a part of a core material.

In FIG. 1, reference numeral 1 denotes a composite material. The composite material 1 comprises a core material 2 and a second thermoplastic resin 3 covering the periphery of the core material 2. The core material 2 is formed by depositing a short fiber (a fiber length of 1 to 40 mm, a fiber diameter of 10 μm) 21 made of carbon fiber and a first thermoplastic resin 22 in which polyethylene terephthalate fiber is shortened by air to form a layer. Heating and pressurizing at a temperature higher than the softening temperature (140 ° C) of polyethylene terephthalate fiber,
A carbon fiber 21 is fixed to a polyethylene terephthalate 22 and molded into a belt-like body.
As shown in (b), the carbon fibers 21 are randomly oriented, and the carbon fibers 21 are made of polyethylene terephthalate 2
2 is a band fixed at 2.

The second thermoplastic resin 3 is a vinyl chloride resin. The molding temperature (die temperature) of the vinyl chloride resin as the second thermoplastic resin 3 is usually around 180 ° C., lower than the melting point (256 ° C.) of the polyethylene terephthalate as the polyethylene terephthalate 22, and also good. It fuses.

FIG. 2 is an explanatory view showing a method of manufacturing a composite material (eave gutter) according to the present invention. Reference numeral 5 denotes an extruder.
Comprises a hopper 51, a barrel (not shown), and a screw (not shown) provided in the barrel.

Reference numeral 6 denotes a preforming device for forming the core material 2, and 61 denotes a hot air heating device for heating only a part of the core material 2. Reference numeral 7 denotes a mold composed of a crosshead die. The mold 7 is attached to the tip of the extruder 5.

Reference numeral 65 denotes a sizing device for forming the composite material 1 extruded from the mold 7 into a substantially eaves gutter 4 into a substantially accurate shape. Reference numeral 8 denotes a take-up device provided with caterpillars 81, 81 on the upper and lower sides. Upper and lower capillaries 81, 81
And pick it up.

FIG. 3 is a sectional view of a mold 7 for producing a composite material (eave gutter). The mold 7 has a gap 71 having substantially the same shape as the composite material (eave gutter) to be formed. The method of using the mold 7 is as follows.
Then, by passing the core material 2 formed into the same shape as the eaves gutter to be formed and extruding the molten vinyl chloride resin 3 from the upper and lower resin passages 72, 72, the periphery of the core material 2 becomes vinyl chloride. The composite material 1 covered with the resin 3 and fused with the vinyl chloride resin 3 and the polyethylene terephthalate 22 is extruded in a substantially eaves gutter shape.

FIG. 4 is an explanatory view showing a cross section of the eaves gutter 4 manufactured by the method for manufacturing a composite material according to the present invention. In the method for manufacturing a composite material according to the present invention, first, in the hot air heating device 61 (FIG. 2), the corners 4a, 4b, 4c, 4d, 4
e, 4f, 4g, 4h, 4i, and 4j, only the position of the core material 2 corresponding to the softening point of polyethylene terephthalate (1
(40 ° C.) or higher and not higher than the temperature at which the carbon fiber can be retained (2
(200-220 ° C). Next, the core material 2 is formed into a substantially eaves gutter 4 shape by the preforming device 6 and passed through the gap 71 of the mold 7. On the other hand, the hopper 5 of the extruder 5
The extruder 5 is operated by putting the vinyl chloride resin 3 into 1.
Then, by the rotation of the screw (not shown), the vinyl chloride resin 3 in the hopper 51 advances toward the mold 7 in the barrel (not shown).

The vinyl chloride resin 3 is melted by a heater attached around the barrel (not shown) while moving through the barrel (not shown), and is formed through the resin passage 72 in the mold 7. The core material 3 is extruded from above and below at a temperature of 190 ° C. and covers the periphery of the core material 3. As a result, core material 2
Is covered with a thermoplastic resin 3 and is extruded as a composite material 1 formed into a substantially eaves gutter 4 shape.

The composite material 1 thus extruded is formed into a substantially accurate shape of the eaves gutter 4 by the sizing device 65, and is taken out by being sandwiched between the upper and lower capillaries 81, 81, cut into a fixed length and cut into a eaves gutter 4. Becomes

[0026]

According to the method for producing a composite material of the present invention as described above, the short fibers fixed with the first thermoplastic resin do not fall apart, and the second thermoplastic resin does not Not only is the heat-resistant composite material fused to the first thermoplastic resin, but also the core material is free from burrowing and cracking, and the resulting composite material is free from deformation and strength reduction.

Therefore, when this composite material is formed into an eaves gutter and used as an eaves gutter, heat resistance is good, expansion and contraction is small, and rust hardly occurs. Moreover, since the core material of the composite material used in the present invention is a belt-like body in which randomly oriented short fibers are fixed with the first thermoplastic resin, it is less expensive than the conventional prepreg sheet. Therefore,
Eaves gutters formed from this composite material into eaves gutters are less expensive.

[Brief description of the drawings]

FIG. 1 shows an example of a composite material obtained according to the present invention,
(A) is a partially cutaway perspective view of the composite material, and (B) is a perspective view showing a part of the core material.

FIG. 2 is an explanatory view showing a method for manufacturing a composite material (eave gutter) of the present invention.

FIG. 3 is a sectional view of a mold for manufacturing a composite material (eave gutter).

FIG. 4 is an explanatory view showing an eaves gutter manufactured by the manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite material 2 Core material 21 Short fiber 22 First thermoplastic resin 3 Second thermoplastic resin 4 Eaves 5 Extruder 6 Preforming device 61 Hot air heating device 65 Sizing device 7 Crosshead die 8 Pulling device

Claims (1)

[Claims] 1. A core material comprising a strip in which short fibers oriented substantially randomly are fixed with a first thermoplastic resin, and only a part of the core material is shorter than the softening point of the first thermoplastic resin. The fiber is heated to a temperature at which the fiber can be held or less, shaped into a shape to be substantially molded, and at a temperature lower than the melting point of the first thermoplastic resin,
A method for manufacturing a composite material, comprising: coating a second thermoplastic resin around the core material.