JPH08300434A - Production of fiber reinforced thermoplastic resin molding - Google Patents

Abstract

PURPOSE: To easily produce a fiber reinforced thermoplastic resin molding having a desired cross-sectional shape high in specific strength and specific rigidity. CONSTITUTION: A single-layered or double-layered fiber reinforced thermoplastic resin sheet is continuously formed into a hollow member 2 and a thermoplastic resin compsn. 3 is extruded into a hollow shape in a molten state to be applied to the inner surface of the hollow member through the opening part thereof on the way of the formation of the hollow member 2 and the whole is guided to a mold 208 and high pressure air is introduced into the thermoplastic resin compsn. 3 to bring the surface of the hollow member 2 into contact with the inner surface of the mold 208 under pressure to form the hollow member 2 and the thermoplastic resin compsn. 3 into a desired shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced thermoplastic resin obtained by coating the surface of a core material layer made of a hollow thermoplastic resin body with a skin layer made of a fiber-reinforced thermoplastic resin. The present invention relates to a method for manufacturing a molded body.

[0002]

2. Description of the Related Art A long molded article having a hollow fiber-reinforced resin having a modified cross-sectional contour as a skin layer and a lightweight material as a core layer inside thereof is excellent in specific strength and specific rigidity. It has already been used as a molded product in the field of building materials and other fields, similar to natural wood or as a substitute. And, in this kind of application, in order to increase the specific strength and the specific rigidity, conventionally, the core layer is made of a thermoplastic resin foam and the skin layer is made of a fiber-reinforced thermosetting resin. Is used.

As a method for producing a molded body having such a fiber-reinforced thermosetting resin as a skin layer and a thermoplastic resin foam as a core layer, a fiber-reinforced thermosetting resin is molded in advance into a hollow body having a desired cross section. In advance, after injecting the expandable thermoplastic resin composition into the inside, by foaming the expandable thermoplastic resin composition at the curing temperature of the fiber-reinforced thermosetting resin, it is composed of the fiber-reinforced thermoplastic resin A method of filling the inside of a hollow body with a resin foam has been proposed (JP-A-1-255530).

[0004]

By the way, according to the above-mentioned proposed method, it is necessary to previously form the fiber reinforced resin to be the skin layer into a hollow body having the same contour as the cross section of the product. It is difficult to perform efficient production by the process.

An object of the present invention is to provide a method capable of easily producing a fiber-reinforced resin molded product having a desired cross-sectional shape with high specific strength and specific rigidity by a continuous molding process.

[0006]

In order to achieve the above-mentioned object, a method for producing a fiber-reinforced thermoplastic resin molding of the present invention comprises a single layer or a single layer as shown in FIGS. While the multilayer fiber-reinforced thermoplastic resin sheet 1 is continuously shaped into the hollow body 2, the thermoplastic resin composition 3 is melted on the inner surface of the hollow body 2 through the opening in the process of shaping. In the state, it is extruded into a hollow shape, and the entire die 208
The hollow body 2 is shaped into a desired shape by introducing the high pressure gas into the inside of the thermoplastic resin composition 3 and pressing the surface of the hollow body 2 against the inner surface of the mold 208. Characterized by: In this case, whether the fiber-reinforced thermoplastic resin sheet 1 is a single layer or how many layers are formed may be appropriately selected according to the intended use of the product.

Here, instead of shaping the fiber-reinforced thermoplastic resin sheet 1 into the hollow body 2 as described above and then extruding the thermoplastic resin composition 3 into the hollow body 2, the fiber-reinforced thermoplastic resin is used. A composite sheet 10 comprising a layer 1a and a thermoplastic resin composition layer 3a is used, and the composite sheet 10 is continuously formed into a hollow body 20 so that the fiber reinforced thermoplastic resin layer 1a is the outer surface. While guiding it into the mold 208,
Under the softened state of the thermoplastic resin composition layer 3a, high pressure air is introduced into the inside of the thermoplastic resin composition layer 3a in the same manner as described above, and the surface of the hollow body 20 is pressed against the inner surface of the mold 208, whereby the hollow body 2
0 may be shaped into a desired shape (see FIG. 4). In this case, the composite sheet 10 has not only one fiber-reinforced thermoplastic resin layer 1a and one thermoplastic resin composition layer 3a, but also a sheet-like or plate-like sheet obtained by alternately laminating and fusing a plurality of layers. You may use the thing.

Further, a fibrous sheet 11 is used in place of the fiber-reinforced thermoplastic resin sheet 1, the fibrous sheet 11 is continuously shaped into a hollow body 21, and an opening in the middle of shaping is used. The thermoplastic resin composition 31 is extruded in a molten state into a hollow shape on the inner surface of the hollow body 21, and the whole is guided into the mold 308, and the thermoplastic resin composition 31
Of the fibrous sheet 11 by impregnating the fibrous sheet 11 with the thermoplastic resin composition 31 by pressurizing the hollow body 21 and the thermoplastic resin composition 31 against the inner surface of the mold 308 by introducing high-pressure air from the inside of the A method of shaping the sheet 11 into a desired shape can be adopted.

In each method of the present invention, the thermoplastic resin used for the skin layer is extruded from a nozzle of φ1 mm × L10 mm at 150 kg / cm ² at a temperature capable of heat fusion using, for example, a Koka type flow tester. A resin having an apparent viscosity of about 1 × 10 ⁵ to 1 × 10 ⁷ poise, that is, a resin that does not easily flow due to its own weight in a melting temperature range (a temperature range in which heat fusion can be performed), further, a fiber, etc. A resin that can suppress fluidity by being combined with is preferable.

Examples of the above-mentioned thermoplastic resins include polyvinyl chloride, chlorinated polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, and polyether ether ketone. Further, these thermoplastic resins may be used alone or in combination of two or more, a heat stabilizer,
Additives such as plasticizers, lubricants, antioxidants, ultraviolet absorbers, pigments, inorganic fillers, reinforcing short fibers, fillers, processing aids and modifiers may be added.

When the method of shaping the fiber reinforced thermoplastic resin sheet 1 or the composite sheet 10 into the hollow body 2 or 20 is adopted in the present invention, the fiber used as the reinforcing fiber is, for example, glass fiber or carbon. Fibers, inorganic fibers such as metal fibers, synthetic fibers such as aramid, vinylon, nylon and polyester, natural fibers such as hemp and cotton (continuously spun yarn), all of which can be used as reinforcing fibers for resins. Fibers can be used.
Further, it is desirable to use long fibers or continuous fibers having a diameter of 1 to several tens of μm or more in order to maintain the impact resistance and not to impair the surface smoothness.

The fiber form inside the fiber-reinforced thermoplastic resin sheet 1 or the fiber-reinforced thermoplastic resin layer 1a of the composite sheet 10 may be a mat-like structure in which long fibers are randomly oriented, or a roving-like structure composed of continuous fibers. It may be in the form of a strand or a cloth, or in the state where the continuous fiber filaments are opened and aligned in the longitudinal direction of the composite. It may be laminated.

On the other hand, when the method of shaping the fibrous sheet 11 into the hollow body 21 is adopted, the fiber of the fibrous sheet 11 is, for example, glass fiber, carbon fiber,
Examples include silicon, titanium, carbon fibers, boron fibers, fine metal fibers, organic fibers such as aramid fibers, polyester fibers, and polyamide fibers, which are fibers that melt at the melting temperature of the thermoplastic resin composition. Don't

The form of the fibrous sheet 11 is preferably a continuous mat, a swirl mat, a chopped strand mat, a fiber cloth or the like in which long fibers or continuous fibers are bound with a small amount of a binder. These fibrous sheets are suitable because the fibers are held in a sheet shape by the binder and the resin easily penetrates between the fibers.

Further, the larger the distance between the fibers in the fibrous sheet 11, the more easily the thermoplastic resin penetrates, and the fiber occupancy per volume is preferably 5 to 15%. If the occupancy rate of the fiber per volume is less than 5%, the reinforcing effect by the fiber is small, and if it exceeds 15%, the thermoplastic resin is less likely to enter between the fibers, which is not preferable. The diameter of the monofilament of the fiber is 1 to 50 μm,
It is particularly preferably 3 to 23 μm. When the total monofilament of the fibers is out of the range of 1 to 50 μm, the reinforcing effect becomes small, which is not preferable.

In the method using such a fibrous sheet 11, the viscosity of the thermoplastic resin extruded into the hollow body 21 in which the fibrous sheet 11 is shaped is such that the thermoplastic resin penetrates between the fibers. It is preferable that it is low, but considering that the same effect can be obtained by increasing the pressure of the gas introduced later when the viscosity is high,
It can be said that the range of 1,000 to 30,000 poise is suitable.

The fiber-reinforced thermoplastic resin sheet 1 of the present invention can be manufactured, for example, as follows. When it is desired to obtain a thermoplastic resin in which continuous long fibers are aligned in one direction and arranged, as shown in FIG. The resin 4 is put into the fluidized state by ejecting air from a perforated plate provided at the bottom of the tank, and a plurality of fiber bundles 5 guided by guide rolls are passed through the resin 4, whereby a thermoplastic resin-attached fiber bundle is obtained. After that, the fibers can be impregnated with the thermoplastic resin by passing through a heating roll or a heating furnace, and then passed through a cooling roll to obtain the fiber-reinforced thermoplastic resin sheet 1.

When obtaining a fiber-reinforced thermoplastic resin sheet in which fibers are randomly arranged in the lengthwise direction, a thermoplastic resin fiber bundle is obtained in the same manner as described above, and then a rotary cutter is used. Pass it through, shred it, drop it on the endless belt and collect it, press it with another endless belt from above, and pass it through the heating furnace while being pressed while sandwiching it with the upper and lower endless belts, It is possible to adopt a method in which the chopped reinforcing fibers are impregnated with a thermoplastic resin and then passed through a cooling guide roll to form a sheet.

On the other hand, the method for producing the composite sheet 10 in the present invention is not particularly limited, but as an example, one surface of the fiber-reinforced thermoplastic resin sheet 1 obtained as described above is melted with the thermoplastic resin composition. Examples thereof include a method of extruding into a sheet and laminating.

The fiber-reinforced thermoplastic resin used for forming the skin layer in the present invention is shaped by being pressed against the inner surface of the mold by a high pressure gas, and at this time, a frictional force is generated between the surface and the mold. To do. Therefore, in order to achieve the object of the present invention, it is difficult for the fiber-reinforced thermoplastic resin to be stretched in the longitudinal direction thereof, but it is desirable that the fiber-reinforced thermoplastic resin has stretchability in the orthogonal direction (width direction). Due to such a relationship, the above-mentioned fiber-reinforced thermoplastic resin is provided with a mat layer in which long fibers are randomly oriented, and at the same time, a stretchable thermoplastic resin is used as the thermoplastic resin impregnated into the mat layer, or a sheet-shaped molding is used. After forming into a body, it is desirable to carry out a crosslinking treatment in order to impart stretchability to the resin. Further, in order to perform the draw-molding while counteracting the frictional force generated between the mold and the mold, in a state where the continuous fibers are aligned in the longitudinal direction of the sheet on at least the surface of the sheet-shaped molded product that contacts the mold inner surface. It is preferable to use the arranged one.

Further, in order to easily cross the fibers with each other, a reinforcing fiber having an axial tensile modulus of 50 GPa or more and a length of 3 cm or less is contacted with a mold of the fiber reinforced thermoplastic resin. It is preferable to arrange them in the longitudinal direction on the surface of.

As the above fibers, fibers of the same type may be used alone, or mixed fibers of fibers of different types may be used. In addition, it is desirable that the continuous fibers are sufficiently impregnated with the thermoplastic resin between the filaments and kept in a state of being retained. In order to improve the adhesiveness between the continuous fibers and the resin, the continuous fibers are preheated. It is preferable to use a material which has been subjected to a surface treatment such as impregnation with a plastic resin.

When the fiber-reinforced thermoplastic resin to be the skin layer is subjected to the crosslinking treatment as described above, for example, active energy rays such as visible rays, ultraviolet rays, α rays, β rays, γ rays, X rays or electron rays, A known method using heat energy, water, or the like can be adopted.

Examples of the thermoplastic resin which is crosslinked by electron beams include thermoplastic resins having α-hydrogen such as polyethylene, polypropylene and polystyrene, and thermoplastic resins which are crosslinked by visible light and ultraviolet rays. If necessary, a thermoplastic resin containing a photopolymerization initiator (photosensitizer) may be used. Examples of the photopolymerization initiator include benzoisoalkyl ether type, acetophenone type, benzophenone type and thioxanthone type.

Further, examples of the thermoplastic resin which is crosslinked by heat energy include thermoplastic resins containing a thermal polymerization initiator such as organic peroxide. Examples of the organic peroxide include isobutyl peroxide, Dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexene, 1,3 bis (t-butylperoxyisopropyl) benzene, t-butyl cumyl peroxide, di-t Examples thereof include those having a relatively high decomposition temperature such as butyl peroxide. At this time, the addition of an organic peroxide generally makes the resin itself easily cleaved, but if the crosslinking does not proceed satisfactorily, a crosslinking aid such as triallyl cyanurate or diallyl phthalate is appropriately added. May be added.

Further, as the thermoplastic resin which is cross-linked with water, for example, a silane-grafted thermoplastic resin grafted with a silane coupling agent typified by alkoxysilane or vinylalkoxysilane, or a silane coupling agent is used. Examples thereof include resins that crosslink in the presence of water, such as polymerized resins. Examples of the silane coupling agent include vinyl silane coupling agents such as vinyltrimethoxysilane and vinyltriacetoxysilane, γ-
Aminosilane coupling agents such as (2-aminoethyl) aminopropylmethyldimethoxysilane and γ- (2-aminoethyl) aminopropylmethyldimethoxysilane,
Epoxysilane coupling agents such as γ-glycidoxypropyltrimethoxysilane, mercaptosilane coupling agents such as γ-mercaptopropylmethyldimethoxysilane, chlorosilane coupling agents such as γ-chloropropyltrimethoxysilane, and the like, γ -Methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride and the like can be mentioned, and known ones can be widely used.

In each of the methods of the present invention, the width and thickness of the fiber reinforced thermoplastic resin forming the skin layer are not particularly limited, but if it is too thin, there is no reinforcing effect, and if it is too thick, shaping is difficult. It is desirable to set it to about 10 mm.
The amount of fibers in the fiber-reinforced thermoplastic resin is preferably from 5 to 70% by volume, and when it is less than 5% by volume, sufficient reinforcing effect and molding stability cannot be obtained, and when it exceeds 70% by volume, the thermoplastic resin is sufficiently thermoplastic. However, it is not preferable because the fusion effect cannot be impregnated and the reinforcing effect is rather reduced.

In the present invention, it is used as the thermoplastic resin composition 3 extruded into the hollow body 2 made of the fiber reinforced thermoplastic resin sheet 1 or the fibrous sheet 11 or the thermoplastic resin layer 3a of the composite sheet 10. The resin used, that is, the thermoplastic resin used as the inner layer (core layer) may be the same as the resin used for the skin layer made of the fiber-reinforced thermoplastic resin, but it is not particularly necessary to use the same. All thermoplastics can be used. Specifically, polyvinyl chloride, chlorinated polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide,
Polysulfone, polyether ether ketone and the like can be mentioned, but the viscosity is relatively low as compared with the thermoplastic resin used for the above-mentioned skin layer in the molding temperature region,
It is preferable to use a resin having good fluidity in order to make the thickness of the skin layer uniform. Further, in relation to the resin used for the skin layer, when the resins used for both layers are in contact with each other and heated to a molten state (a state capable of heat fusion) and pressure-bonded, the interface fused after cooling is It should be selected so that it will not easily break.

The thermoplastic resin used in the above core material layer may be used alone or as a mixture of plural kinds, and may be a heat stabilizer, a plasticizer, a lubricant, an antioxidant,
UV absorbers, pigments, inorganic fillers, additives such as reinforcing short fibers, processing aids, modifiers and the like may be added.

The thickness of the core material layer should be appropriately selected according to the required strength based on the intended use of the product in order to support the skin layer from the inside and develop the strength, but it is generally 3 to 30 of the skin layer.
It is necessary about twice. If it is 3 times or less, the strength will be insufficient, and if it exceeds 30 times, the core material layer itself will be heavy, and on the contrary, the specific strength and the specific rigidity will decrease.

The thermoplastic resin composition used in the core layer may contain reinforcing fibers, and the fiber diameter and fiber length are not particularly limited, but they are effective for increasing the specific strength and specific rigidity of the molded product. Therefore, it may be positively included. In addition to such reinforcing fibers, for the purpose of recycling, cost reduction, etc., the fiber-reinforced thermoplastic resin molded product obtained by each method of the present invention is crushed, wood material, wood powder, crushed sheet molding compound ( S
MC) etc. may be contained. In particular, when the pulverized powder of the fiber-reinforced thermoplastic resin molded product obtained by each method of the present invention is used, it can be used as a resin for the core material layer itself.

As the high-pressure gas used in each method of the present invention, air pressurized by a compressor, nitrogen gas or argon gas in a high-pressure cylinder can be used. The pressure varies depending on the viscosity of the thermoplastic resin composition in the molten or softened state and the fiber-reinforced thermoplastic resin as the skin layer, but is generally 0.3 kg / atmospheric pressure or more.
It is enough if it is at least cm ² .

Further, in order to supply such a high-pressure gas to the inside of the hollow body inside the mold, it is necessary to provide an air pipe through the inside of the mold 202 as shown in FIG. 2, for example. And the pressure of this high-pressure gas is a hollow fiber-
The mold 202 is provided so as to effectively act on the inner surface of the resin composite.
It is necessary to provide a plug 206 for confining gas inside the hollow body by means of a rod-shaped or string-shaped support 206a that passes through the inside of the hollow body. This stopper 206
Is the cross-sectional shape in the direction orthogonal to the longitudinal direction of the hollow body,
It is preferable that the cross-sectional shape of the hollow portion of the hollow body be similar and that the size be slightly smaller.

The outermost surface of the fiber-reinforced thermoplastic resin molded article produced by each of the methods of the present invention is covered with the fiber-reinforced thermoplastic resin, which gives specific strength and specific rigidity. In the above, if necessary, a thermoplastic resin layer may be further laminated on the outer side of the layer so that the fiber-reinforced thermoplastic resin does not directly appear to the outside. As a result, the fiber-reinforced thermoplastic resin molded article can increase the smoothness of the surface and enhance the utility value.

[0035]

The present invention provides a molded article having a fiber-reinforced resin as a skin layer and having a high specific strength and a high specific rigidity, which has a structure in which a thermoplastic resin hollow body is used as a core material layer in place of a conventional resin foam. It is an attempt to obtain a product with good productivity. By providing a hollow thermoplastic resin as the core material layer, it is possible to obtain the same lightness as that of a molded product having a conventional resin foam as the core material layer, and by combining with a skin layer made of a fiber-reinforced thermoplastic resin, Compared with the conventional structure, the reinforcing efficiency is good, and a molded product with extremely high specific strength and specific rigidity can be obtained, and at the same time, all of the resin used is a thermoplastic resin, so the whole is crushed into a core material layer. A molded body that can be reused and can be recycled can be obtained.

Among the methods of the present invention, in the method of using the fiber-reinforced thermoplastic resin sheet 1, a thermoplastic resin having a high melt viscosity, that is, a resin which does not easily flow due to its own weight in the melting temperature range is held on the fiber in advance. Then, the sheet-shaped product is shaped into a hollow body 2, and the thermoplastic resin composition 3 is extruded into the hollow body 2 at the same time, or simultaneously with the subsequent pressurization with a gas from the inside, While closely adhering the thermoplastic resin composition 3 to the inside of the hollow body 2 made of the fiber-reinforced thermoplastic resin sheet 1,
By pressing the surface of the hollow body 2 against the inner surface of the mold 208 by the pressure to form a skin layer made of a fiber reinforced thermoplastic resin and a core material layer made of a hollow thermoplastic resin,
It is possible to continuously and integrally form an arbitrary cross-sectional shape according to the inner surface shape of the die 208 to be used.

The composite sheet 10 comprising the fiber reinforced thermoplastic resin layer 1a and the thermoplastic resin composition layer 3a is shaped into the hollow body 20 so that the fiber reinforced thermoplastic resin layer 1a is the outer surface. When the thermoplastic resin composition layer 3a is melted or softened and high-pressure gas is introduced into the thermoplastic resin composition layer 3a and pressed into a similar mold to shape the whole, the inner surface shape of the mold is the same as above. Accordingly, it becomes possible to continuously form a fiber-reinforced thermoplastic resin molded body having an arbitrary cross-sectional shape.

Further, after the fibrous sheet 11 is continuously shaped into the hollow body 21, the thermoplastic resin composition 31 is extruded hollowly from the inner surface of the hollow body 21 and a high pressure gas is introduced into the hollow body 21 to form a mold. In the pressure contact method, the thermoplastic resin composition 31 is infiltrated into the fibrous sheet 11 in the molds 302 and 308 by the pressure of gas to manufacture the fiber-reinforced thermoplastic resin, and the entire mold is pressed by the pressure of gas. Since it is pressed against 308 and shaped, a fiber-reinforced thermoplastic resin molded product having an arbitrary cross-sectional shape can be continuously integrally molded without manufacturing a fiber-reinforced thermoplastic resin to be a skin layer in advance.

[0039]

According to the present invention, a fiber reinforced having a very high specific strength and a high specific rigidity, comprising a skin layer made of a fiber reinforced thermoplastic resin and a core layer made of a hollow thermoplastic resin. It becomes possible to continuously mold the thermoplastic resin molded body by integrating the skin layer and the core material layer,
It has become possible to significantly improve the productivity as compared with the conventional manufacturing method in which the fiber reinforced skin layer is preformed and the core material layer is filled therein.

[0040]

EXAMPLES An example of actually producing a fiber-reinforced thermoplastic resin molded article using each method of the present invention will be described below together with comparative examples. <Example 1> This example is an example of a method including a step of shaping a fiber-reinforced thermoplastic resin sheet into a hollow shape and extruding a molten thermoplastic resin composition on the inner surface thereof into a hollow shape. Production of Fiber Reinforced Thermoplastic Sheet As shown in FIG. 1, a powdered thermoplastic resin composition 4 (having a particle diameter of about 80 μm) having a composition shown in the following [Table 1] is housed in the upper and lower flow tanks 101, respectively. In addition, while the powdered thermoplastic resin composition 4 is fluidized by the air that is pressure-fed to each of the fluid tanks 101, the inside of each of the fluid tanks 101 is made into a glass fiber aggregate bundle. 5 (4400 tex) each passing 24 pieces, the thermoplastic resin composition 4 is adhered to the filaments of the glass fiber aggregate bundle 5 and then combined, and the temperature is adjusted to about 200 ° C. while being pressed by a roll or the like. By passing through the heating furnace 102 described above, the thermoplastic resin composition 4 was melted and impregnated to obtain the fiber-reinforced thermoplastic sheet 1. In addition, after the glass fiber aggregated bundle 4 passed through the flow tank 101, the net-shaped glass fiber material 6 was sandwiched between the upper and lower glass fiber aggregated bundles 4. The volume ratio of the resin of the fiber-reinforced thermoplastic resin sheet 1 to the glass fiber material was 70:30.

[0041]

[Table 1]

Manufacture of Fiber Reinforced Thermoplastic Resin Molded Body FIG. 2 is a cross-sectional view showing the construction of an apparatus for manufacturing a fiber reinforced thermoplastic resin molded body used in this example, and FIG. 3 shows A to E in FIG. A sectional view of a material or a molded body is shown. In FIG. 2, the left side in the figure is called the upstream side and the right side is called the downstream side.

The fiber-reinforced thermoplastic resin sheet 1 produced by the above-mentioned procedure is wound around the rewinding roll 201, and adjacent to the rewinding roll 201, the outer mold 20.
A hollow body shaping / resin extruding die 202 including 3 and a core die 204 therein was provided. In this hollow body shaping / resin extrusion die 202, a space having an inverted U-shaped cross section for inserting the fiber reinforced thermoplastic resin sheet 1 is opened in the upstream end face portion, and the space is As it progresses to the downstream side, it gradually changes into a true circular cylindrical cross-sectional shape with a diameter of 29 mm, and when the fiber-reinforced thermoplastic sheet 1 passes through it, the cross-sectional shape gradually changes from an inverted U-shaped cross-section to a hollow of a true circular shape. The shape 2 is shaped.

In the core mold 204, the upstream end is bent downward through the opening in the middle of which the fiber-reinforced thermoplastic resin sheet 1 is formed in the cylindrical hollow body 2, and the bent lower end thereof. At the resin extruder 205. In addition, the core mold 204 is formed with a cylindrical resin discharge port 204a that opens toward the downstream side, and the resin discharge port 204a is a cylindrical resin formed inside the core mold 204. It communicates with the resin extrusion port of the resin extruder 205 via the flow path 204b, and the thermoplastic resin composition 3 described later can be extruded into the inner surface of the hollow body 2 in a cylindrical shape. Further, at the center of the core mold 204, the core mold 2
04 for supplying gas toward the downstream side of 04
c is formed. This hole 204c is used for the core mold 2
The high pressure air can be supplied to the inside of the resin extruded in a cylindrical shape from the core mold 204 by communicating with the air discharge port of the external compressor (not shown) through the outer mold 203 from 04. Further, in the core mold 204, holes 2 are formed inside the thermoplastic resin composition 3 extruded in a cylindrical shape.
The stopper 206 for holding the pressure of the high-pressure gas supplied through 04c is a thin rod-shaped or string-shaped support member 20.
It is supported via 6a.

On the downstream side of the hollow body shaping / resin extrusion die 202, a heat insulating material 207, a heating die 208, and a heat insulating material 209.
The cooling mold 210 was arranged in that order, and the take-up machine 211 was arranged further downstream thereof.

The heating die 208 has a vertical cross section of 29 m in diameter.
A die 20 having a rectangular cavity with a vertical cross section of 27 × 27 mm is also provided on the downstream side of the die 208a having a circular cavity of m.
The cavities of the two dies 208a and 208b are surface-processed so that the inner surface of the cylinder and the inner surface of the rectangle are smoothly connected in the vicinity of the connection portion. Further, as for the heat insulating material 209 and the cooling die 210, a cavity having a rectangular cross section of 27 × 27 mm is formed similarly to the die 208b.

The above-mentioned stopper 206 is located in a die 208b having a rectangular cross section of the heating die 208, and its outer shape and dimensions are similar to the cross sectional shape of the cavity of the die 208b. , The dimensions are rather small.

Now, using the manufacturing apparatus as described above, the fiber-reinforced thermoplastic resin sheet 1 (width 91 mm, thickness 1.2 mm) is rewound from the rewinding roll 201 and shaped into a hollow state and also a resin extrusion die. By passing through the die 202, the state shown in FIG. 3A is passed through the inverted U-shaped cross section of FIG. 3B, and the side edges are abutted without overlapping as shown in FIG. While continuously shaping the tubular hollow body 2 having a thickness of 0.0 mm and a thickness of 1.2 mm, the resin discharge port 204a of the core die 204 is formed on the inner surface of the hollow body 2 after shaping.
To thermoplastic resin composition 3 having the composition shown in [Table 2] below
Was melted and extruded into a cylindrical shape.

[0049]

[Table 2]

Here, the resin composition 3 having the composition shown in [Table 2] was previously kneaded and pelletized by a 30φ twin-screw extruder at a temperature of 170 ° C. or lower, and this was used as a resin extruder 205 (40φ). A single-screw extruder, L / D = 30, compression ratio 2.5) extruded into a cylindrical shape at a resin temperature of 200 ° C. and laminated on the inner surface of the hollow body 2, and at the same time the core mold 2
Air having a pressure of 2 kg / cm ² (gauge pressure of 1 kg / cm ² ) was introduced from the hole 204c of No. 04 to pressurize the thermoplastic resin composition 3 from the inside. As a result, the extruded thermoplastic resin composition 30 adheres to the inner peripheral surface of the hollow body 2 as shown in FIG. 3 (D), and at the same time, the outer peripheral surface of the hollow body 2 contacts the inner surface of the heating die 208. It is pressed and gradually shaped from the original circular contour to a rectangular contour.

Then, while the resin temperature is kept at 200 ° C. by the heating die 208, the pressure contact of the surface of the hollow body 2 to the inner surface of the heating die 208 is completed, and then the cooling die 21.
By cooling the surface temperature of the hollow body 2 to 60 ° C. by 0, as shown in FIG. 3 (E), the skin layer S made of the fiber reinforced thermoplastic resin and the core made of the hollow thermoplastic resin are used. A fiber-reinforced thermoplastic resin molded body composed of the material layer P and having a square cross section with one side of 27 mm was continuously molded. The average diameter of the holes formed in the center of this molded body is 18
mm. Also, in this example, the molding speed is 1.
It is 5 m / min, and when the molded body after continuous molding is cut into a regular length of 4 m, the molding time per product is 2.8 mi.
It was n. <Example 2> This example is an example including a step of shaping a composite sheet including a fiber-reinforced thermoplastic resin layer and a thermoplastic resin composition layer into a hollow shape. Production of composite sheet Fiber-reinforced thermoplastic resin sheet 1 produced in Example 1
A thermoplastic resin composition 3 having the composition shown in [Table 2] and used in Example 1 was extruded at a temperature of 170 ° C. and laminated on one surface (width 91 mm, thickness 1.2 mm), and FIG. A composite sheet 10 including the fiber-reinforced thermoplastic resin layer 1a and the thermoplastic resin composition layer 3a as shown in (A) was manufactured. The thickness of the thermoplastic resin composition layer 3a was 5 mm. The manufacturing apparatus of the fiber-reinforced thermoplastic resin molded body is basically the same as the apparatus shown in FIG. 2, but of these, the resin extruder 205 is unnecessary, and
The hollow body shaping / resin extrusion die 202 has a core die 2
The resin discharge port 204a and the resin flow path 204b are not required in 04 and are used exclusively for shaping a hollow body. And, the void between the core mold 204 and the outer mold 203 is a hollow of the composite sheet 10 having a cross-section of an inverted U-shape shown in FIGS. It is necessary to set the size so that it can be shaped into the body 20. Other,
Shapes and dimensions of the heating mold 208, the heat insulating material 209, and the cooling mold 210, the temperature of each mold, and the take-up device 210.
Was the same as in Example 1.

The composite sheet 10 is wound around the rewinding roll 201, and this is passed through the mold 202 to form the hollow body 20, and then the air having the same pressure as that of the first embodiment is supplied into the hollow body 20. The hollow body 20 was continuously molded into a rectangular contour under the same mold temperature of each part as in Example 1, and fiber reinforced having the same shape and structure as that shown in FIG. 3 (E). A thermoplastic resin molded body was obtained. The molding speed was the same as in Example 1, and the molding time per one 4 m product was 2.8 min. <Example 3> This example is an example including a step of extruding the thermoplastic resin composition into a cylindrical shape from the inside while shaping the fibrous sheet into a hollow shape. Materials to be used For the fibrous sheet, continuous glass fiber bundles with a monofilament diameter of 9 μm are randomly combined and held with an epoxy resin binder to provide a continuous mat (450 g / m 2
² , width 94.2 mm, manufactured by Asahi Fiber) was used.

As the thermoplastic resin composition, a polyvinyl chloride resin containing polyvinyl chloride as a main component and having a composition shown in the following [Table 3] is stirred and mixed with a super mixer until the temperature reaches 100 ° C. Was used.

[0054]

[Table 3]

Manufacture of Fiber Reinforced Thermoplastic Resin Molded Body FIG. 5 is a sectional view showing the construction of an apparatus for manufacturing a fiber reinforced thermoplastic resin molded body used in this example, and FIG. Or shows a cross-sectional view of the molded body.

The above-mentioned fibrous sheet 11 is wound around a sheet feeding machine 301, and adjacent to this, a hollow body shaping and resin extruding die consisting of an outer die 303 and a core die 304 therein. A mold 302 was provided. In this resin extrusion mold 302, a void having an inverted U-shaped cross section for inserting the fibrous sheet 11 is opened at the upstream end face portion thereof, like the one shown in FIG. The cross section changes from a reverse U-shaped cross section to a perfect circular cross section in which both side edges are abutted, as the fibrous sheet 11 passes therethrough as the cylindrical cross section gradually changes to a true circle with a diameter of 30 mm. The hollow body 21 is shaped.

The core mold 304 is made of the fibrous sheet 1.
1 passes through an opening in the middle of which the hollow cylindrical body 21 is shaped, and the upstream end bends downward to form a resin extruder 305.
The flow path of the resin supplied from the resin extruder 305 is connected to the outer peripheral part of the core mold 304 and is formed between the inner peripheral surface of the outer mold 303 and the cylindrical shape. Of the cylindrical void 304a.
Along the line a, the resin composition 31 having the composition shown in Table 3 above is extruded into a cylindrical shape in a molten state.

With the above-described structure, the fibrous sheet 11 inserted into the hollow state shaping and resin extruding die 302 is shaped into the hollow body 21 having a perfect circular cross section, and then the resin composition 31 is applied from the inside. Will be extruded.

The core mold 304 is also formed with holes 304b for supplying gas toward the downstream side thereof, and the resin composition extruded into a cylindrical shape through the holes 304b. A high pressure gas supplied from an external compressor (not shown) can be supplied to the inside of 31. The pressure of the high-pressure gas is held by the plug 306 supported by the core mold 304 via the rod-shaped or string-shaped support member 306a, as in the example of FIG.

On the downstream side of the hollow body shaping / resin extruding die 302, the heat insulating material 307 and the heating die 3 are provided as in the example of FIG.
08, the heat insulating material 309, and the cooling die 310 were arranged in order, and the take-up machine 311 was arranged further downstream thereof. However, in this example, the inner surfaces of the heating mold 308 and the cooling mold 310 were both circular with a diameter of 30 mm. The cross-sectional shape of the plug 306 is circular with a diameter slightly smaller than 30 mm in this example.

Now, the fibrous sheet 11 made of the continuous mat described above is inserted from the sheet insertion port of the hollow body shaping / resin extrusion die 302 whose temperature is adjusted to 180 ° C., and FIG. After changing from the state shown to the state of (B) to form the hollow body 21 as shown in (C), the thermoplastic resin composition 31 having the composition shown in the above [Table 3] is directed toward the inner surface thereof.
Was extruded and air having a gauge pressure of 2 kg / cm ² was supplied to the inside through the holes 304b. This air pressure causes the thermoplastic resin composition 31 to enter the hollow body 21 made of the fibrous sheet 1 in the heating die 308 heated to 180 ° C., and these are heated by the heating die 308.
After pressure contact with the inner surface of the No. 3, the surface was cooled to a surface temperature of 70 ° C by a cooling die 310 cooled to 10 ° C. As shown in FIG. 6 (D), the product thus obtained has a two-layer structure in which a core layer P made of a hollow resin layer is provided inside a skin layer S made of a glass fiber-containing resin. became. The molding speed in this example is the same as in Examples 1 and 2.
Same as above, the molding time for one 4m product is 2.8m
It was in. <Comparative Example> A hollow glass fiber-resin composite 73 having a square cross section with an outside dimension of 27 mm square serving as a skin layer was molded by using the molding process shown in FIG. 7.

In the figure, 71 is a roving-like glass fiber bundle (4
After passing through a resin liquid tank 701 in which a liquid thermosetting resin (unsaturated polyester) is injected, it is transferred in a predetermined direction through a plurality of aligning devices 702, and the resin-attached glass fiber On the outer circumference of the bundle 71, a non-woven fabric (glass fiber continuous mat) 7
2 was fed while being unrolled and fed into a pultrusion die 703 having a 26 mm square core with a square cross section.
Then, while being heated and cured at 180 ° C. in this molding die 703, it was taken out by a take-up device 704 and cut every 4 m to obtain a hollow glass fiber-resin composite 73. The molding time at this time required 4 min per one.

On the other hand, as the core material layer, the resin composition having the composition shown in [Table 2] used in Example 1 was used,
It was a 4.5 mm square square, and the inner surface side was formed into a circular body having an inner diameter of 18 mm and a length of 4 m. After applying an adhesive to the outer peripheral surface of the tubular body, the hollow glass fiber described above-
It was inserted into the resin composite 73 and adhered to each other.

As described above, in the comparative example, the skin layer and the core layer were individually molded and cut into a predetermined length,
It was necessary to bond each product via an adhesive, and the total molding time was 12 min including the working time of 1 min required for insertion.

[Brief description of drawings]

FIG. 1 is an explanatory view of a manufacturing process of a fiber-reinforced thermoplastic resin sheet 1 in Example 1.

FIG. 2 is a cross-sectional view of an apparatus for manufacturing a fiber-reinforced thermoplastic resin molding according to Example 1.

FIG. 3 is a sectional view of a material or a product in each part of FIG.

FIG. 4 is a cross-sectional view of the material in each step of the manufacturing process of the fiber-reinforced thermoplastic resin molding of Example 2.

FIG. 5 is a sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin molding according to Example 3.

6 is a sectional view of a material or a product in each part of FIG.

FIG. 7 is an explanatory view of a manufacturing process of a fiber-resin composite in a comparative example.

[Explanation of symbols]

 1 Fiber Reinforced Thermoplastic Resin Sheet 2 Hollow Body 3 Thermoplastic Resin Composition 10 Composite Sheet 1a Fiber Reinforced Thermoplastic Resin Layer 3a Thermoplastic Resin Composition Layer 20 Hollow Body 201 Rewind Roll 202 Hollow Body Forming and Resin Extrusion die 203 Outer die 204 Core die 204a Resin discharge port 204b Resin flow passage 204c Hole 205 Resin extruder 206 Plug 206a Support 208 Heating die 210 Cooling die 211 Take-up device 11 Fiber sheet 21 Hollow body 31 thermoplastic resin composition 302 hollow body shaping and resin extrusion die 303 outer die 304 core die 304a cylindrical cavity 304b hole 305 resin extruder 306 plug 306a support 308 heating die 310 cooling die 311 Take-up device S Skin layer P Core material layer

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Claims (3)

[Claims] 1. A single-layer or multi-layer fiber-reinforced thermoplastic resin sheet is continuously shaped into a hollow body, and a thermoplastic resin is formed on the inner surface of the hollow body through an opening part in the process of shaping. The composition is extruded into a hollow state in a molten state, the whole is guided into a mold, and high-pressure gas is introduced into the inside of the thermoplastic resin composition to press the hollow body surface against the inner surface of the mold. By shaping the hollow body into a desired shape,
A method for producing a fiber-reinforced thermoplastic resin molding. 2. A composite sheet comprising a fiber reinforced thermoplastic resin layer and a thermoplastic resin composition layer, which is continuously formed into a hollow body so that the fiber reinforced thermoplastic resin layer is on the outer surface of the mold. In addition, by introducing a high-pressure gas into the thermoplastic resin composition layer in a molten or softened state of the thermoplastic resin composition layer to press the hollow body surface against the inner surface of the mold, the hollow body is formed into a desired shape. A method for producing a fiber-reinforced thermoplastic resin molded body which is shaped. 3. A fibrous sheet is continuously shaped into a hollow body, and the thermoplastic resin composition is hollowed in a molten state on the inner surface of the hollow body through an opening part in the process of shaping. With extrusion, guide the whole into the mold, and, by introducing a high-pressure gas from the inside of the thermoplastic resin composition by pressing the hollow body and the thermoplastic resin composition to the inner surface of the mold, A method for producing a fiber-reinforced thermoplastic resin molded product, which comprises shaping a fibrous sheet into a desired shape while impregnating the fibrous sheet with the thermoplastic resin composition.