JP2974582B2 - Method for producing fiber-reinforced thermoplastic resin foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing a fiber-reinforced thermoplastic resin foam comprising a core layer composed of a thermoplastic resin foam and a skin layer composed of a fiber-reinforced thermoplastic resin sheet. About.

[0001]

2. Description of the Related Art A molded article having a long cross-sectionally irregular shape and having a foamed layer inside is used as a molded article having excellent rigidity in construction materials and other fields in the same manner as natural wood or as an alternative thereto. Has been used as In such an application, in order to increase rigidity, a molded article having a core material layer formed of a thermoplastic resin foam and a skin layer formed of a fiber-reinforced thermosetting resin composite is used.

Japanese Patent Application Laid-Open No. 4-339635 discloses that in order to continuously produce a composite having excellent mechanical strength and light weight, a synthetic resin foam is continuously transferred in one direction while being transferred to the outer surface thereof. Supply continuous fiber impregnated with thermosetting resin,
A production method of drawing by heating is disclosed. However, in this method, it is necessary to prepare a foamed molded article having an irregular cross-sectional shape in advance, and since a low-viscosity resin is used for performing the pultrusion molding, the thickness unevenness of the skin layer and the mechanical strength are not sufficient. There have been problems such as that uniform portions are easily generated, and that deformation and shaping inside the mold are difficult.

[0003]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to produce a fiber-reinforced thermoplastic resin foam in which the skin layer is a fiber-reinforced thermoplastic resin and the core material layer is a foam. An object of the present invention is to provide a method for producing a fiber-reinforced thermoplastic resin foam having less unevenness and excellent mechanical strength such as bending strength.

[0004]

First, the invention according to claims 1 to 7 will be described.

[0005] The invention according to claim 1 is a step of continuously forming one or a plurality of fibrous sheets into a hollow shape, and supplying the foamable resin composition to the inner surface of the hollow body while foaming the foamable resin composition. And a step of shaping the hollow body into a desired shape by foaming pressure.

According to a second aspect of the present invention, there is provided a step of continuously forming one or a plurality of fibrous sheets into a hollow body, supplying a foamable resin composition to an inner surface of the hollow body, The method includes heating the foamable resin composition to a temperature equal to or higher than the foaming temperature of the foaming agent, and shaping the hollow body into a desired shape by foaming pressure.

According to a third aspect of the present invention, there is provided a step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets into a hollow body, and a step of pneumatically forming the hollow body into a predetermined cross-sectional shape. And a step of supplying a foamable resin composition containing a thermoplastic resin and a foaming agent to the inner surface of the hollow body while foaming the foamed body, and forming the hollow body into a desired shape by foaming pressure. Features.

According to a fourth aspect of the present invention, there is provided a step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets into a hollow body, and a step of pneumatically forming the hollow body into a predetermined cross-sectional shape. And, on the inner surface of the pneumatically formed hollow body, a foamable resin composition containing a thermoplastic resin and a foaming agent is supplied, and the foamable resin composition is heated to a foaming temperature or higher of the foaming agent, and the hollow A step of shaping the body into a desired shape by foaming pressure.

According to a fifth aspect of the present invention, a composite sheet comprising one or a plurality of fiber-reinforced thermoplastic resin layers and a foamable resin composition layer is continuously formed such that the fiber-reinforced thermoplastic resin layer becomes an outer surface. Forming the hollow body into a hollow body, pneumatically forming the hollow body into a predetermined cross-sectional shape, and foaming the foamable resin composition layer, and shaping the hollow body into a desired shape by the foaming pressure. It is characterized by including a step.

[0010] According to a sixth aspect of the present invention, one or a plurality of fiber-reinforced thermoplastic resin sheets in which a large number of continuous fibers are oriented are continuously applied to a hollow body so that the continuous fibers extend in the longitudinal direction. Forming, supplying the hollow body into the mold,
On the inner surface of the hollow body, a foaming resin composition containing a thermoplastic resin and a foaming agent is supplied while foaming, and while the hollow body is pulled out, the step of shaping the hollow body into a desired shape by foaming pressure is performed. It is characterized by including. The invention according to claim 7 is a step of continuously forming one or more fiber-reinforced thermoplastic resin sheets in which a large number of continuous fibers are oriented into a hollow body such that the continuous fibers are in the longitudinal direction. Step of supplying a hollow body into a mold, on the inner surface of the hollow body, supplying a foamable resin composition containing a thermoplastic resin and a foaming agent,
The method includes heating the foamable resin composition to a temperature equal to or higher than the foaming temperature of the foaming agent, and forming the hollow body into a desired shape by foaming pressure while extracting the hollow body. Oite the present invention <br/>, the thermoplastic resin used in the fiber-reinforced thermoplastic resin sheet is not particularly limited, for example, polyvinyl chloride, chlorinated polyvinyl chloride, vinyl chloride - vinyl acetate copolymer, Vinyl chloride-acrylic acid copolymer, polymethyl methacrylate, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, polyether ether ketone, and the like, as well as thermoplastic elastomers,
In the shaping step, the fiber-reinforced thermoplastic resin sheet may be stretched. In such a case, it is preferable to use a thermoplastic resin having a high stretchability, and a moderate cross-linking treatment is performed to improve the stretchability. You may.

The use of a thermoplastic resin having a melt viscosity of 1 × 10 5 to 1 × 10 7 poise is preferable because uneven thickness of the skin layer hardly occurs. In the present invention, the melt viscosity refers to an apparent viscosity when extruded from a nozzle of φ1 mm × L10 mm under a condition of 150 kg / cm 2 at a temperature at which heat fusion is possible using a Koka type flow tester.

The above-mentioned thermoplastic resins may be used alone or in combination. Addition of heat stabilizers, plasticizers, lubricants, antioxidants, ultraviolet absorbers, pigments, inorganic fillers, reinforcing short fibers, etc. Agents, fillers, processing aids, modifiers and the like may be added.

The fibers used in the fiber-reinforced thermoplastic resin sheet include, for example, inorganic fibers such as glass fiber, carbon fiber and metal fiber; synthetic fibers such as aramid fiber and vinylon; and natural fibers such as silk, cotton and hemp. All fibers that can be used as reinforcing fibers can be used.

In order to maintain the impact resistance of the obtained fiber-reinforced thermoplastic resin sheet and not to impair the surface smoothness, a long fiber or continuous fiber having a diameter of 1 to 100 μm and a length of 10 mm or more is used. Is good. The form of the fiber inside the fiber reinforced thermoplastic resin sheet is not particularly limited, and may be, for example, a mat shape in which long fibers are randomly oriented; or a roving shape, a strand shape, or a cross shape made of continuous fibers; Examples include a state in which the book is spread and aligned in the longitudinal direction of the composite, a state in which a plurality of these fiber states are combined, and the like.

The fiber-reinforced thermoplastic resin sheet used in the present invention is not particularly limited, and is manufactured, for example, as follows. When trying to obtain a fiber-reinforced thermoplastic tree sheet having a fiber form arranged and aligned in one direction, put the powdery thermoplastic resin in the tank of the fluidized tank, from the perforated plate provided in the tank bottom A plurality of fiber bundles guided by guide rolls are passed through in a fluidized state by jetting air, and a thermoplastic resin adhered or / and penetrated fiber bundle is formed. It is impregnated with a thermoplastic resin and passed through a cooling roll to obtain a desired fiber-reinforced thermoplastic resin sheet. When it is intended to obtain a fiber-reinforced thermoplastic resin sheet in which fibers are randomly arranged, the thermoplastic resin-adhered or / and penetrating fiber bundle obtained as described above is shredded with a rotary cutter. Then, it is dropped and accumulated on the lower endless belt, pressed and sandwiched by the upper and lower endless belts, passed through the heating furnace, impregnated with the chopped fibers with the thermoplastic resin, and then passed through the cooling guide roll. Thus, a desired fiber-reinforced thermoplastic resin sheet is obtained.

When a thermoplastic resin having a low melt viscosity is used, it is also possible to produce a thermoplastic resin sheet by immersing fibers in a thermoplastic resin in a molten state.
In such a case, it is preferable to crosslink the thermoplastic resin after producing the fiber-reinforced thermoplastic resin sheet.

In the case where the hollow body is subjected to pneumatic molding, in order to improve the airtightness of the hollow body and improve the shaping property, a thermoplastic resin is previously impregnated between the fiber bundles or obtained in the above-mentioned production method. It is preferable that the fiber-reinforced thermoplastic resin sheet is subjected to a surface treatment to improve the adhesion between the fiber and the thermoplastic resin. The fiber reinforced thermoplastic resin sheet may be a single layer or a laminate of a plurality of fiber reinforced thermoplastic resin sheets.

The thickness of the fiber reinforced thermoplastic resin sheet is not particularly limited. However, if the thickness is small, there is no reinforcing effect, and if the thickness is large, shaping becomes difficult. Therefore, the thickness is preferably 0.1 to 10 mm. The amount of fibers in the fiber reinforced thermoplastic resin sheet is
If the amount is too small, sufficient reinforcing effect and molding stability cannot be obtained.If the amount is too large, the thermoplastic resin cannot be impregnated and fusion becomes difficult. 5 to 70% by volume is preferable because the shapeability of the hollow body becomes insufficient due to a decrease in the property.
50% by volume is more preferred.

The above fiber-reinforced thermoplastic resin sheet is formed into a hollow body, and is formed by pneumatic molding or / and foaming pressure. At that time, the hollow body may be regulated from outside by a regulating body such as a mold, and a frictional force is generated between the regulating body and the fiber-reinforced thermoplastic resin sheet. Therefore, when forming while drawing while resisting frictional force, the fiber form of the fiber reinforced thermoplastic resin sheet is continuous in the longitudinal direction of the fiber reinforced thermoplastic resin sheet in order to prevent the fiber reinforced thermoplastic resin sheet from being cut or the like. Preferably, the fibers are aligned. In the case of laminating fiber-reinforced thermoplastic resin sheets and using them in multiple layers, it is sufficient that at least one of them has the above-mentioned form.

The use of a composite sheet in which a foamable resin composition layer is laminated on one side of a fiber-reinforced thermoplastic resin layer composed of the above-mentioned fiber-reinforced thermoplastic resin sheet, instead of the fiber-reinforced thermoplastic resin sheet, can be obtained. Gas generated from the foamable resin composition enters the interface between the surface layer of the fiber reinforced thermoplastic resin foam and the core material layer, and voids are formed between the surface layer of the obtained fiber reinforced thermoplastic resin foam and the core material layer. This is preferable because it is possible to obtain a fiber-reinforced thermoplastic resin foam having excellent fusion between the surface layer and the core material layer. The foamable resin composition layer is the same as the foamable resin composition described below, which is supplied to the inner surface of the hollow body without being foamed. As in the case of the fiber reinforced thermoplastic resin sheet, the composite sheet may be used as a single layer or a laminate of a plurality of composite sheets.

The method for producing the composite sheet is not particularly limited.
For example, a method for producing a composite sheet by heat-sealing a foamable resin composition sheet produced in advance on one surface of the fiber-reinforced thermoplastic resin sheet obtained by the above method; a fiber obtained by the above method A method of extruding and laminating an unfoamed foamable resin composition on one surface of a reinforced thermoplastic resin sheet to form a composite sheet, or the like, may be used.

A fibrous sheet may be used instead of the above fiber-reinforced thermoplastic resin sheet. When the fibrous sheet is used, when the foamable resin composition is foamed and the hollow body is shaped by the foaming pressure, the fibrous sheet can be impregnated with the foamable resin composition, and the fiber reinforced thermoplastic resin can be used in advance. Since there is no need to manufacture a sheet or the like, the steps can be omitted, which is preferable.

The fibers used in the fibrous sheet include:
It is not particularly limited as long as it does not melt at the melting temperature of the thermoplastic resin constituting the foamable resin composition or at the foaming temperature of the foamable resin composition. For example, glass fiber, carbon fiber, silicon / titanium / carbon Fiber, boron fiber, metal fiber, aramid fiber, polyester fiber, polyamide fiber and the like.

When the monofilament diameter of the fiber used in the fibrous sheet is reduced, the reinforcing effect is reduced, and
As the weight increases, the weight per unit area is reduced so that the weight per unit area is reduced so as not to impair the lightness, the contact area between the resin and the fiber decreases, and the obtained fiber reinforced thermoplastic resin As the strength of the foam surface layer decreases,
It is preferably from 1 to 50 μm, more preferably from 3 to 23 μm.

The fibrous sheet refers to a sheet formed by depositing or entangled fibers, and is preferably a small amount of long fibers or continuous fibers such as continuous mat, swirl mat, chopped strand mat, and fiber cloth. Those bound with a binder are preferred.

When the porosity of the fibrous sheet decreases,
The impregnation of the resin into the fibrous sheet due to the foaming of the foamable resin composition is reduced, and the surface layer and the core material layer are easily peeled off. It is preferably volume%.

When the hollow body is shaped, the hollow body may be stretched completely or partially. In such a case, the hollow body may be cracked or thinned by the stretching, and a part of the surface layer of the obtained fiber-reinforced thermoplastic resin foam may have a partially reduced rigidity. To prevent this, when using the above fiber-reinforced thermoplastic resin sheet or fibrous sheet, on the outer surface or inner surface of the hollow body, and when using a composite sheet, on the outer surface of the hollow body, a thermoplastic material having excellent stretchability. A resin layer may be laminated. In particular, it is preferable to laminate the thermoplastic resin layer on the outer surface, in addition to the effects described above, because the smoothness of the surface layer of the obtained fiber-reinforced thermoplastic resin foam is improved.

When the hollow body is subjected to pneumatic molding,
Laminating the thermoplastic resin layer as described above is preferable because it has the effect of improving the airtightness of the hollow body and improving the shapeability of the hollow body.

The method of shaping the fiber-reinforced thermoplastic resin sheet, the composite sheet and the fibrous sheet into a hollow body is not particularly limited. For example, in addition to a method using a mold described later in Examples, a synthetic resin And a method of bending gradually with a metal shoe or roll. When forming into a hollow shape, in order to prevent the fiber-reinforced thermoplastic resin sheet, composite sheet or fibrous sheet from cracking or tearing, it is heated with a far-infrared heater or hot air blower to form the thermoplastic resin while softening it. Preferably, shaping is performed.

The term "hollow body" as used in the present invention includes not only those formed by abutting or overlapping the ends but also forming a slight gap between the ends.

When a hollow body is subjected to pneumatic molding, a thermoplastic resin having a high melt viscosity is used as a fiber-reinforced thermoplastic resin sheet or a composite sheet. In the case where is integrated by melting of the thermoplastic resin, even if the ends are abutted and shaped into a hollow body, there is no problem because the shapeability by pneumatic molding does not decrease. Otherwise, in order to improve the airtightness of the hollow body and improve the shapeability, it is preferable that the hollow body is formed by overlapping the ends thereof.

When shaping the fiber-reinforced thermoplastic resin sheet, composite sheet, and fibrous sheet into a hollow body, a plurality of fiber-reinforced thermoplastic resin sheets or the like are used to abut or overlap each end. In addition, it may be shaped into a hollow body.

In particular, when the entire circumference of the desired cross-sectional shape becomes larger than the entire circumference of the hollow body by pneumatic molding or shaping by foaming pressure, the end portions of a plurality of fiber-reinforced thermoplastic resin sheets or the like are used. To form a hollow body by overlapping each other by an amount corresponding to the portion corresponding to the portion to be stretched in the shaping process, the overlapped portion is displaced when stretching, and each fiber-reinforced thermoplastic By stretching the resin sheet little by little, the degree of stretching of each fiber-reinforced thermoplastic resin sheet becomes smaller than when a hollow body is formed by a single fiber-reinforced thermoplastic resin sheet or the like.

Accordingly, by forming a plurality of fiber-reinforced thermoplastic resin sheets or the like into a hollow body by overlapping the end portions thereof, the thickness of the skin layer is reduced, and the obtained fiber-reinforced thermoplastic resin sheet is formed. It is possible to prevent the rigidity of the foam from lowering, and to prevent the hollow body from being partially stretched greatly in the process of shaping the hollow body, so that the obtained skin layer is partially thinned. It is possible to obtain a fiber-reinforced thermoplastic resin foam having the same rigidity as a whole, which is preferable.

[0035] The invention according to claim 1, 2, 6, 7 is a hollow body obtained as described above, characterized in that to shape into a desired shape by foaming pressure, according to claim 3, 4 The present invention is characterized in that the hollow body obtained as described above is shaped into a desired shape by pneumatic molding and foaming pressure.
The invention described in 5 is characterized in that the hollow body obtained as described above is shaped into a desired shape by air pressure molding and foaming pressure due to foaming of the foamable resin composition. The pneumatic forming includes not only vacuum forming but also pneumatic forming. Needless to say, “air” includes not only so-called “atmosphere” but also a gas such as nitrogen gas.

As described in the third to fifth aspects of the present invention, forming the hollow body by air pressure together with the shaping of the expandable resin composition by the foaming pressure is more efficient than forming by the foaming pressure alone. Thus, when it is desired to obtain a complicated cross-sectional shape, a fiber-reinforced thermoplastic resin foam having a particularly accurate cross-sectional shape can be obtained, which is preferable.

The foamable resin composition used in the present invention comprises:
Contains a thermoplastic resin and a foaming agent. Examples of the thermoplastic resin include all foamable thermoplastic resins, for example, polyvinyl chloride, chlorinated polyvinyl chloride,
Polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, polyetheretherketone, and the like, but in the molding temperature range, relative to the thermoplastic resin used for the fiber-reinforced thermoplastic resin sheet. It is preferable to use a resin having a low viscosity and a good flowability in order to prevent uneven foaming and to improve the uniformity of the thickness of the skin layer of the obtained fiber-reinforced thermoplastic resin foam.

The thermoplastic resin used for the fiber-reinforced thermoplastic resin sheet or the like serving as the skin layer does not need to be the same as the thermoplastic resin used for the foamable resin composition. was heated to fusible state), when the crimp as long as a state of the interface after the cohesion after cooling is not easily peeled off, the combination of both,
There is no particular limitation.

However, when a fibrous sheet is used, the melt viscosity of the thermoplastic resin used for the expandable thermoplastic resin is as follows:
If it is too high, it becomes difficult to impregnate the resin between the fibrous sheets, and if it is too low, the resulting foam does not have uniform and fine cells, so the range of 6,000 to 30,000 poise is preferable.

The thermoplastic resin used in the foamable resin composition may be used alone or as a mixture of a plurality of thermoplastic resins. The heat stabilizer may be used within a range that does not impair the foamability of the foamable resin composition. Plasticizers, lubricants, antioxidants, ultraviolet absorbers, pigments, inorganic fillers, additives such as reinforcing fibers, fillers, processing aids, modifiers, and the like may be added. From the viewpoint of recycling, waste plastic, woody material, wood flour, ground powder of sheet molding compound (SMC) and the like are preferable.

In the case where the reinforcing fibers are added,
There is no reinforcing effect, and when it increases, it becomes difficult to foam uniformly, and on the contrary, the reinforcing effect is reduced.
30% by volume is more preferred.

Further, a cross-linking treatment may be performed to improve the foamability. The crosslinking treatment method is not particularly limited, for example, visible light, ultraviolet light, α-ray, β-ray, γ-ray, X
A method of crosslinking by irradiation with an active energy ray such as a beam or an electron beam, a method of adding an organic peroxide to decompose and crosslink, a method of adding a crosslinkable silane-modified thermoplastic resin and performing a water treatment to perform crosslinking. Can be

Examples of the thermoplastic resin crosslinked by an electron beam include thermoplastic resins having α-hydrogen such as polyethylene, polypropylene and polystyrene.
Examples of the thermoplastic resin that can be crosslinked by visible light and ultraviolet light include a thermoplastic resin containing a photopolymerization initiator (photosensitizer) if necessary. Examples of the photopolymerization initiator include benzoin alkyl ether-based Acetophenone type, benzophenone type, thioxanthone type and the like.

The organic peroxide is not particularly restricted but includes, for example, isobutyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexene, 3-bis (t-butylperoxyisopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide and the like. At this time, the addition of the organic peroxide generally causes the thermoplastic resin itself to be easily cleaved.However, when the crosslinking does not proceed to a desired degree, a crosslinking auxiliary such as triallyl cyanurate or diallyl phthalate is appropriately added. It may be added.

The foaming agent is not particularly limited, and may be a decomposable foaming agent that decomposes to generate gas, a physical foaming agent that generates gas by vaporization, or a gas. Azodicarbonamide, azobisisobutyronitrile, N, N'-dinitropentamethylenetetramine, p, p'-oxybisbenzenesulfonylhydrazide, barium azodicarboxylate, trihydrazinotriazine, 5-phenyltetrazole and the like. Can be

Examples of the physical foaming agent include aliphatic hydrocarbons such as isopentane, heptane and cyclohexane;
Fluorinated aliphatic hydrocarbons such as trichlorotrifluoroethane and dichlorotetrafluoroethane are exemplified. Examples of the gas include air, nitrogen, and helium. The above foaming agent, when the foaming ratio of the foam obtained by adding a large amount increases, the rigidity of the foam constituting the obtained core material layer decreases, the foaming ratio is preferably 30 times or less, and within this range It is preferable to mix them.
Specifically, in the case of a decomposition type foaming agent and a physical type foaming agent,
Although it depends on the type of the foaming agent, the amount is preferably 1 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin.

In the present invention, without using a composite sheet,
When using a fiber-reinforced thermoplastic resin or a fibrous sheet, it is necessary to supply a foamable resin composition, but the supply of the foamable resin composition to the hollow body surface may be performed while foaming. Alternatively, it may be supplied without foaming.

As a method of supplying the foamable resin composition while foaming the foamable resin composition, for example, a foaming agent is kneaded or impregnated at a temperature not higher than the foaming temperature of the foaming agent with the thermoplastic resin. After it is obtained, it is supplied to an extruder and heated to a temperature higher than the foaming temperature of the foaming agent, and supplied while being foamed. A method in which a physical foaming agent or gas is supplied in the middle of the machine, and supplied while foaming is performed. In the present invention, the term "foaming temperature" refers to the decomposition temperature of a decomposable foaming agent and the boiling point of a physical foaming agent. Note that the decomposition temperature refers to a temperature at which the half life is 3 minutes. However, needless to say, at the foaming temperature, the foamable resin composition is in a foamable state.

Next, as a method of supplying the foamable resin composition in an unfoamed state, for example, the foaming agent is kneaded or impregnated with a thermoplastic resin at a temperature lower than the foaming temperature of the foaming agent. A method of obtaining a resin composition and supplying the resin composition in a desired shape such as a pellet, a sheet, a rod, a pipe, or the like can be given.

When the foamable resin composition is foamed, it is not necessary to supply an amount sufficient to fill the inside of the hollow body. The hollow body is shaped into a desired shape by being regulated by a regulating body such as a mold, but it is sufficient to add an amount sufficient to obtain a foaming pressure enough to be pressed against the regulating body, For example, the mold core may be extended to the mold cooling portion to restrict foaming, and a void portion may be formed everywhere in the final molded body,
By changing the supply amount of the foamable resin composition or the take-up speed of the hollow body, the core material layer of the obtained fiber-reinforced thermoplastic resin foam has a foam-filled portion and a non-filled portion of the foamable resin composition. The site may be arbitrarily shaped. In the present invention, the foaming pressure means not only the foaming pressure generated by the foamable resin composition alone, but also the foaming pressure of the foamable resin composition alone does not provide a pressure enough to press the hollow body against the regulating body. In such a case, pressure is separately applied to the inside. In such a case, the pressure refers to the pressure added. When pressure is separately applied to the inside, it is preferable that an air pipe is provided through the inside of the restricting body so that a gas is supplied to the inside of the hollow body.

The method of foaming the unfoamed foamable resin composition supplied to the inner surface of the hollow body is not particularly limited, and examples thereof include a method of blowing hot air from inside and / or outside the hollow body. When supplying the foamable resin composition while foaming, the hollow body may be heated as necessary.

The foamable resin composition is foamed, and the hollow body is shaped into a desired shape by the foaming pressure. The method for shaping the hollow body into a desired shape is not particularly limited. In addition to the method of supplying the body to a regulating body such as a mold having a desired cross-sectional shape and pressing a fiber-reinforced thermoplastic resin sheet or the like against the regulating body by foaming pressure to form a desired shape, Depending on the desired shape of the plastic resin foam, the regulation by the regulating body is not performed, and a method of shaping the hollow body by the foaming pressure may be used.

When the foaming ratio of the inner core material layer exceeds 30 times, the foamed layer itself cannot hold the stress and the stiffness is lowered rather than 30 times. The magnification can be appropriately selected, and is preferably 1.5 to 5 times.

When a fibrous sheet is used, the foamable resin composition is impregnated between the fibers while foaming. In order to obtain a core material layer having a high expansion ratio, the foamable resin composition is formed. When using a high viscosity thermoplastic resin, the thermoplastic resin may be difficult to impregnate between the fibers,
In such a case, it is preferable to use a method in which the cross-sectional shape of the regulating body that regulates the hollow body is gradually reduced so that the molten thermoplastic resin is easily impregnated between the fibers. Specifically, for example, after continuously forming the fibrous sheet into a hollow body, supplying the foamable resin composition to the hollow body surface, and foaming the foamable resin composition in the mold And squeezing the fibrous sheet in the inner surface direction to facilitate the impregnation of the fibrous sheet with the thermoplastic resin constituting the foamable resin composition.

Next, the invention according to claim 8 will be described. The invention according to claim 8 is a step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets partially overlapped in the width direction into a hollow shape. A step of supplying a composite foamable sheet in which a foamable resin composition is impregnated in a mat-like substance as a component, and integrating the composite foamable sheet with a hollow body; The thickness of the composite foamable sheet in the hollow body is increased by pneumatically molding the body and heating the foamable resin composition to a temperature equal to or higher than the foaming temperature of the foaming agent.
The method is characterized by including a step of stretching.

As the fiber reinforced thermoplastic resin sheet used in the present invention, the same one as described above is used. A method for continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets partially overlapped in the width direction into a hollow shape, the form of the obtained hollow body is the same as that described above. The same is true.

The composite foamable sheet used in the present invention comprises:
The fibrous sheet is impregnated with a foamable resin composition. The fibrous sheet used for the composite foamable sheet may have a slightly larger amount of a binder than that used for the surface layer constituting the fiber-reinforced thermoplastic resin foam. The fibrous sheet is not particularly limited,
For example, a swirl mat, a continuous mat, a chopped strand mat and the like can be mentioned.

When the length of the fibers constituting the mat-like material is short, the fibers are not entangled with each other, and the shape of the mat-like material cannot be maintained. Since it becomes difficult to orient various fibers,
00 mm is preferred.

The diameter of the fibers constituting the mat-like material is preferably from 1 to 50 μm, since the thinner the fiber, the lower the reinforcing effect, and the larger the diameter, the more difficult it is to form the mat-like material.
Further, it is preferably from 7 to 23 μm.

The same foaming resin composition as described above is used. The method for producing the composite foamable sheet is not particularly limited. For example, the foamable resin composition in a molten state is supplied to the mat-like material at a temperature lower than the foaming temperature, and then the matte-like material is pressed. A method for producing a composite foamable sheet by impregnating the inside; supplying the powdery foamable resin composition to the inside of the mat-like material by vibration or air, and then melting the mat-like material at a temperature lower than the foaming temperature. And a method of producing by impregnation.

In the present invention, the composite foamable sheet is supplied into the hollow body, and the hollow body and the composite foamable sheet are integrated. The method of integration is not particularly limited. The hollow body supplied with the composite foamable sheet,
The outlet cross section is supplied to a mold whose taper shape is smaller than the inlet cross section, and the mold is at least the melting point of the thermoplastic resin used for the hollow body or the thermoplastic resin used for the composite foamable sheet, and A method of maintaining and lowering the foaming temperature of the decomposable foaming agent at a temperature lower than the melting temperature of the thermoplastic resin used for the hollow body or the thermoplastic resin used for the composite foamable sheet and foaming the decomposable foaming agent. A method in which a hollow body is pressed from the outside with an external regulating body kept at a temperature lower than the temperature to integrate the hollow body with the outside regulating body, and the like.

[0062] Then, a hollow body which is integrated with the composite foamable sheet, with pneumatically molding, heating the foamable resin composition or foaming temperature of the foaming agent, double the hollow body
To expand the thickness of the composite foamable sheet, the method of pneumatic molding and heating to a temperature higher than the foaming temperature is performed in the same manner as described above.

The method for expanding the thickness of the composite foamable sheet is not particularly limited. For example, the thickness of the hollow body may be increased in at least one direction by pneumatic molding and foaming pressure. The hollow body integrated with the composite sheet is supplied to a pneumatically moldable mold having a cross-sectional area larger than the cross-sectional area of the body, and the composite foam is formed by pneumatic molding and foaming.
There is a method of expanding the thickness of the conductive sheet . Sheet
When expanding thickness, composite foamable sheet in hollow body
It is preferred that the fibers are preferentially expanded only in the thickness direction because the fibers are preferentially oriented in a specific direction in the obtained fiber-reinforced thermoplastic resin foam, and the compressive strength is improved.

The expansion ratio of the obtained inner core layer is usually 30 or less, preferably 1.5 to 5 for the same reason as described above.
Doubled.

[0065]

According to the method for producing a fiber-reinforced thermoplastic resin foam of the present invention, a fiber-reinforced thermoplastic resin sheet or the like is used as a skin layer, and the fiber-reinforced thermoplastic resin sheet or the like is shaped into a hollow body. The foamable resin composition is supplied to the inner surface and foamed, and the hollow body is shaped by the foaming pressure. Therefore, there is no need to prepare a preformed foam, and since the hollow body is shaped by the foaming pressure, thickness unevenness of the skin layer made of the hollow body hardly occurs.

Since a thermoplastic resin is used for the skin layer and the core material layer and is formed by foaming pressure, it can be formed into a desired shape in the manufacturing process, and fiber reinforced having a complicated cross-sectional shape can be formed. A thermoplastic foam can be obtained.

Furthermore, the foaming resin foaming pressure causes the foaming resin in the molten state to push the hollow body from the inside with a uniform force, so that the surface layer and the core material layer are fused. Since they are integrated, there is no partially weakly fused portion at the interface between the surface layer and the core material layer, and a fiber-reinforced thermoplastic resin foam having uniform quality such as rigidity can be obtained.

When the hollow body is stretched during the shaping process, a plurality of fiber-reinforced thermoplastic resin sheets or the like are formed into a hollow body by overlapping the ends so as to correspond to the stretched portion. The overlapping portion between each fiber reinforced thermoplastic resin sheet is shifted, and each fiber reinforced thermoplastic resin sheet is stretched little by little, so that the obtained skin layer can be thinned, and It is possible to prevent the occurrence of a partially large and thin portion. When a composite sheet is used, gas generated from the foamable resin composition remains at the interface between the skin layer and the core material layer, and the surface layer and the core material layer of the obtained fiber-reinforced thermoplastic resin foam. It is possible to prevent voids from being generated between them.

When a fibrous sheet is used, the foamable resin composition foams and the resin is impregnated between the fibers of the fibrous sheet. Therefore, it is not necessary to manufacture a fiber-reinforced thermoplastic resin sheet or the like in advance. , The process can be omitted.

By forming the hollow body by foaming pressure and / or pneumatic molding, it is possible to accurately obtain a fiber-reinforced thermoplastic resin foam having a complicated cross-sectional shape, which cannot be obtained by foaming pressure alone. Can be.

By using a fiber reinforced thermoplastic resin sheet having a large number of continuous fibers oriented and shaping the continuous fibers into a hollow body so as to be in the longitudinal direction, the fiber reinforced thermoplastic resin sheet is drawn out while the hollow body is pulled out. A plastic foam can be manufactured. Supply composite foamable sheet into hollow body,
After integration, pneumatic molding, foaming, foaming
By expanding the thickness of the porous sheet, the fibers constituting the composite foamed sheet supplied into the hollow body become foamable.
Since the sheet is preferentially oriented in the thickness direction of the sheet , the compressive strength is improved.

EXAMPLES The present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited to these examples. In the drawings, "front" means rightward.

Example 1 A fiber-reinforced thermoplastic resin sheet was produced by the following method. As shown in FIG. 1, a roving-like glass fiber bundle 1 (44) composed of a filament having a diameter of 23 μm.
00tex) are arranged in two rows of 24 pieces each,
Polyvinyl chloride (melt viscosity 2.4 × 10 5 poise) 10
0 parts by weight, 1 part by weight of tin heat stabilizer, polyethylene wax
A powdery resin composition 2 having a particle diameter of about 80 μm consisting of 0.5 parts by weight is passed through a fluidized tank 3 fluidized by air fed from the direction of the arrow to form a glass fiber bundle 1. After the powdery resin composition 2 is adhered to the filament, the resin composition 2 is heated and pressed by passing through a heating furnace 4 heated to about 200 ° C. to melt and impregnate the resin composition 2 to a thickness of 1.2 mm. Thus, a fiber-reinforced thermoplastic resin sheet 5 was obtained. After the glass fiber bundle 1 passed through the fluidizing tank 3, the net-like glass fiber 6 was sandwiched between the upper and lower glass fiber bundles 1. The content of glass fibers in the fiber-reinforced thermoplastic resin sheet 5 was 30% by volume.

The apparatus for manufacturing a fiber-reinforced thermoplastic resin sheet shown in FIG. 2 has a width of 91 m manufactured as described above.
m, thickness = 1.2 mm, fiber reinforced thermoplastic resin sheet 5
Roll 6 around which is wound, an extruder 7 for extruding the foamable resin composition, and disposed in front of the rewind roll 6, the front end portion is bent at a right angle forward, and an annular hole is formed in the center portion thereof. A mold 8 provided for forming the sheet 5 into a circular shape, an inner core 9 fixed to the rear end of the mold 8 and projecting forward and having a circular vertical cross section, A heat insulating material 10, a heating mold 11, a heat insulating material 12, and a cooling mold 13 are disposed in front of the apparatus, and a take-off machine 14 is provided in front of the heat insulating material 10, the heating mold 11, and the cooling mold 13.
The vertical sectional shape of the heating mold 11 is a circle having a diameter of 29 mm. The heat insulating material 12 and the cooling mold 13 in front of 11 also have the same cross-sectional shape.

A U-shaped gap in which the fiber-reinforced thermoplastic resin sheet 5 can be inserted is provided behind the mold 8, and the fiber-reinforced thermoplastic resin sheet 5 is inserted through the gap, and the mold 8 is inserted.
Inside, the sheet is abutted from the U-shape without overlapping the both ends of the sheet 5, the outer diameter is 29.0 mm, and the thickness is 1.2 m.
m, and 100 parts by weight of polyvinyl chloride, 2.5 parts by weight of a tin-based heat stabilizer, and a lubricant inside a fiber-reinforced thermoplastic resin sheet 5 formed continuously into a hollow body of m. 0.5
A foamable resin composition 15 consisting of 3 parts by weight, 8 parts by weight of an acrylic processing aid, 5 parts by weight of CaCO3, 2 parts by weight of dioctyl phthalate, and 3.5 parts by weight of sodium bicarbonate (foaming temperature: 175 ° C.) At a resin temperature of 30 kDa, a single screw extruder with a screw diameter of 40 mm (L /
D = 30, compression ratio 2.5), extruded and laminated at a resin temperature of 200 ° C. and started foaming at the same time.
In the cooling mold 13, the outer layer surface temperature is cooled to 60 ° C., and the foaming ratio of the core material layer is about 3.2 times, and the cross-sectional shape is 29 in diameter.
The fiber-reinforced thermoplastic resin foam 16 having a circular shape of mm was continuously molded at a molding speed of 1.5 m / min.

The obtained fiber reinforced thermoplastic resin foam 16
The flexural strength, flexural modulus and compressive strength, the maximum value, minimum value and CV value of the thickness of the surface layer were measured by the following methods,
The results are shown in Table 1.

(Bending strength and flexural modulus) Measured according to JIS K7221. (Compression strength) In the flatness test according to JIS G3448, the value obtained by dividing the load when the distance of the flat plate was compressed to a height of 2/3 by the area where the flat plate and the test piece were in contact at that time was defined as the compressive strength. (Maximum value, minimum value of surface layer) From the obtained fiber-reinforced thermoplastic resin foam, 1
0 portions were cut out, further divided into 10 portions, the thickness of each surface layer was measured, and the maximum value and the minimum value were taken. (CV value) From the above measurements, the standard deviation and average value were determined, and the CV value was determined by the following equation. CV value = 100 × standard deviation / average value (Example 2) A fiber-reinforced thermoplastic resin was prepared in substantially the same manner as in Example 1 except that the glass fibers 6 in a net shape were not sandwiched between the glass fiber bundles 1. Sheet 5 was produced. The content of glass fibers in the fiber-reinforced thermoplastic resin sheet 5 was 50% by volume. In the mold 11 of the manufacturing apparatus used in Example 1, the inlet cross-sectional shape was a circular shape having a diameter of 29 mm, and the outlet shape was 2 mm.
Example 1 was performed using the manufacturing apparatus used in Example 1 except that the shape was a 7 × 27 mm rectangle, and the internal shape of the mold gradually changed from the inlet shape to the outlet shape.
In the same manner as described above, a fiber-reinforced thermoplastic resin foam 16 having a core material layer having a foaming ratio of 2.8 times and a cross-sectional shape of 27 × 27 mm was continuously molded at a molding speed of 1.2 m / min. . The flexural strength and flexural modulus, the maximum value, the minimum value and the CV value of the thickness of the surface layer of the obtained fiber-reinforced thermoplastic resin foam 16 were measured in the same manner as in Example 1, and the fiber-reinforced thermoplastic resin foam was used. 16 was measured by the following method, and the results are shown in Table 1. (Compressive strength) Measured according to JIS K7208.

(Example 3) Three fiber reinforced thermoplastic resin spare sheets which were produced in advance from a fiber reinforced resin sheet were used. Heating, pressurizing and integrating were obtained. For the production of the fiber reinforced thermoplastic resin spare sheet, FIG.
Was used. Fluidized vessel 17 and fluidized vessel 17
Behind, a plurality of rewinding rolls 1 arranged in parallel
8 and take-up drive rolls 19 (in some cases, take-up drive rolls 19, 1
9), a rotary cutter 20 opposed to the take-up drive roll 19 and opposed thereto, upper and lower endless belts 21 and 22 opposed to each other at a predetermined interval, and an opposing transfer portion of both endless belts 21 and 22. Heating furnace 2 arranged for
3, a thickness adjuster 28 and a vertical cooling guide roll 24, and a feed portion 22b is provided behind the lower endless belt 22, and the feed portion 22b is
It was located below the cutter 20.

The two endless belts 21 and 22 are configured to move continuously in the same direction at substantially the same speed by driving one of the upper and lower pulleys 27 by a motor. there were. The rear part of the transfer section 21a of the upper endless belt 21 is inclined rearward and upward, and the gap between the upper and lower transfer sections 21a and 22a is widened rearward. The upper and lower endless belts 21 and 22 were formed of steel having high strength and heat resistance. Heating furnace 23
The hot air circulation type was used, and the upper and lower transfer portions 21a and 22a of the upper and lower endless belts 21 and 22 passed through this.

In the above apparatus, fifteen reinforcing fiber bundles 25A (having a fiber diameter of 17 μm) made of roving glass fiber bundles unwound from the unwinding roll 18 are guided to the fluidizing tank device 17, where the freezing state is achieved. Ground high-density polyethylene (melt viscosity 1.1 × 10 5 poise) particles 2
6 was allowed to pass through the fiber while being opened, and the resin was adhered so that the ratio of the resin to the reinforcing fibers was 3: 2 (volume ratio). The resin-attached fiber bundle 25B is cut into 37.5 mm by the rotary cutter 20, and the cut resin-attached fiber bundle 25B is cut.
C feeding section 2 into the gap between upper and lower endless belts 21 and 22
2b, the cut resin-attached fiber bundle stack 25D was pressed in the thickness direction while being sandwiched between the moving endless belts 21 and 22, and passed through a heating furnace 23 in which hot air was circulating. . Subsequently, the mixture of the resin and the reinforcing fiber bundle in the molten state is cooled while being pressurized, and the reinforcing fiber having a length of 37.5 mm is randomly distributed in the thermoplastic resin. A plastic resin spare sheet 25E was obtained. Fiber reinforced thermoplastic resin spare sheet 25E
Medium, the content of glass fiber was 40% by volume. or,
The same procedure as in Example 2 was repeated except that high-density polyethylene having a particle diameter of 80 μm was used as the powdery resin composition and the thickness was adjusted to 0.3 mm. Obtained. The fiber-reinforced thermoplastic resin preliminary sheet 25E was sandwiched between two fiber-reinforced thermoplastic resin preliminary sheets 25F and integrated to obtain a fiber-reinforced thermoplastic resin sheet 5 having a thickness of 1.2 mm.

100 parts by weight of high-density polyethylene, 100 parts by weight of homopropylene, 30 parts by weight of a silane crosslinkable polypropylene resin, azodicarbonamide (foaming temperature: 190
° C) 5 parts by weight, glass fiber (filament diameter 14μ)
m, fiber length 2 mm) 10 parts by weight, screw diameter 30 m
m, and the mixture was melt-kneaded at 175 ° C., pelletized, immersed in hot water at 100 ° C. for 1 hour, and dried to obtain a foamable resin composition.

In FIG. 2, the above pellets were extruded from a single screw extruder having a screw diameter of 40 mm (L / D = 30, compression ratio 2.
5) melt-kneaded at 165 ° C., extruded and laminated in an unfoamed state, and then heated by a heating mold 11 temperature-controlled at 205 ° C. to start foaming, and the foamed resin is deposited on the hollow body surface. After filling, the mixture is introduced into a cooling mold 13 and the surface is cooled to 60 ° C. Further, although not shown, a ventilation hole is provided inside the mold core 9 from the rear of the mold core 9 to form the mold core 9. The pressure of the space formed near the tip was adjusted to 1.3 kg / cm 2, and the surface of the heating mold 11 and the cooling mold 13 that contacted the hollow body was covered with tetrafluoroethylene, and the molding speed was increased to 1. Except for 8 m / min, in the same manner as in Example 2, the expansion ratio of the core material layer was 2.9 times, and the cross-sectional shape was 27 × 27.
Thus, a fiber-reinforced thermoplastic resin foam 16 having a rectangular shape of mm was obtained.

The obtained fiber-reinforced thermoplastic resin foam 16
The flexural strength, flexural modulus and compressive strength, and the maximum, minimum and CV values of the thickness of the surface layer were measured in the same manner as in Example 2, and the results are shown in Table 1.

Example 4 A fiber-reinforced thermoplastic resin was prepared in the same manner as in Example 2 except that a frozen and pulverized polypropylene having an average particle size of 100 μm (melt viscosity: 1.6 × 10 5) was used as the thermoplastic resin. A resin sheet was manufactured and this was designated as 29A. In the fiber-reinforced thermoplastic resin sheet 29A, the content of glass fiber is 4
It was 0% by volume. The apparatus for manufacturing a fiber-reinforced thermoplastic resin foam shown in FIG. 4A is provided with a rewinding roll 29 around which a fiber-reinforced thermoplastic resin sheet 29A is wound, and is disposed in front of the rewinding roll 29, and has a front end folded forward. Bent, sheet 2
An inner layer foamable resin composition supply device 30 capable of shaping 9A into a rectangle, a roll 31 pressing the end portions of the fiber-reinforced thermoplastic resin sheet 29A, a cross-sectional shape slightly larger than a rectangle having a width of 50 × 25 mm in thickness. Width 60 x thickness 30
As shown in FIG. 4 (b), the shaping mold 32 which gradually changes to a shape lacking both lower corners and which surrounds the shaping mold 32 is heated. A hand heater 40, a heat insulating material 33 and a cooling mold 34 are disposed in front of the hand heater 40, and a take-off device 35 is provided in front of the hand heater 40.
The supply device 30 had a foamable resin composition supply passage 37, a vent hole 38, and a mesh (not shown) that could allow only air to pass in front of it. Further, a hot air heating device 36 for heating the overlapping portion of the sheet end is provided,
Although not shown, the supply device 30 is provided with a guide roll for surrounding the sheet and shaping the sheet into a rectangle.

The fiber-reinforced thermoplastic resin sheet 29A obtained above is continuously shaped into a rectangular shape, and the overlapped portion is heated by a hot air heating device 36 at 150 ° C. It was shaped into a shape. The hollow body is continuously taken out and drawn into the shaping mold 32, and at the same time, the foamable resin composition 39 (100 parts by weight of high-density polyethylene, 100 parts by weight of homopolypropylene, 30 parts by weight of silane crosslinkable polypropylene, azodicarbonamide (foaming temperature 19
(0 ° C.) in the same manner as in Example 3, and pelletized) is supplied to the inner surface of the hollow body while the resin temperature is 180 ° C., while not foaming. The foamable resin composition was foamed while controlling the take-up speed so that the foaming resin composition began to foam at the inside of the mold 32, particularly at a portion where the cross-sectional shape gradually changed. The foamed resin was formed by stretching the fiber-reinforced thermoplastic resin sheet 29A in the width direction and pressing the foamed resin against the inner surface of the mold 32 by foaming pressure. This is taken and taken into a cooling mold 34 in which cooling water having a water temperature of 5 ° C. circulates, and cooled until the surface layer reaches about 40 ° C.
A molding speed was 0.5 m / min, and a fiber-reinforced thermoplastic resin foam 41 having a foaming ratio of the core material layer of 2.85 times was continuously obtained.

The obtained fiber-reinforced thermoplastic resin foam 41
The flexural strength, flexural modulus and compressive strength, and the maximum, minimum and CV values of the thickness of the surface layer were measured in the same manner as in Example 2, and the results are shown in Table 1.

Example 5 A fiber-reinforced thermoplastic resin sheet was obtained in the same manner as in Example 1, except that polypropylene (melt viscosity: 1.6 × 10 5 poise) was used as the powdery resin composition. This was designated as 42B. Further, 100 parts by weight of high-density polyethylene, 15 parts by weight of silane crosslinkable polypropylene resin, 5 parts by weight of azodicarbonamide (foaming temperature 190 ° C.), 10 parts by weight of glass fiber (filament diameter 14, fiber length 5 mm), screw diameter 30 mm To the twin screw extruder,
After being melted and heated at a temperature of 170 ° C., the fiber-reinforced thermoplastic resin sheet 42B is extrusion-laminated in a sheet shape having a thickness of 1 mm,
A composite sheet 42A having a thickness of 2 mm and a width of 204 mm, in which a foamable resin composition layer 42C is laminated on one surface of a fiber-reinforced thermoplastic resin layer 42B, is obtained.
Immersed in hot water for 1 hour and dried. At one end of the obtained composite sheet 42A, as shown in FIG.
No foamable resin composition layer was laminated.

FIG. 5A shows the manufacturing apparatus used in the fifth embodiment. The manufacturing apparatus has a rewind roll 42a around which the composite sheet 42A obtained above is wound, and a front end portion thereof is bent forward and at a right angle, and an intake hole 46 and an exhaust hole 47 are provided therein. Composite sheet 42A
Can be formed into a hollow shape, a guide roll 54 for forming the composite sheet 42A into a hollow shape along the die 43 around the die 43, and the ends of the composite sheet 42A are connected to each other. Heating device 4 for heating the superposed part
5, a pressure roll 44 for pressing the overlapped portion heated by the heating device 45, and an inlet cross-sectional shape shown in FIG.
The heating mold 48, the heater 49, and the heating die 48 shown in FIG. 5 (c) have an elliptical shape as shown in FIG. C)
A heat insulating material 50, a cooling mold 51, and a take-off machine 53 having a cross-sectional shape shown in FIG.

As shown in FIG. 5 (d), the composite sheet 42A is separated by the mold 43 and the guide roll 54 into a portion where the foamable resin composition layer is inside and the foamable resin composition layer is not laminated. After shaping into a hollow shape so as to form an overlapping portion, the overlapping portion was heated to 190 ° C. by a heating device 45 and pressed by a pressure roll 44. Further, the obtained hollow body is supplied to a mold 48 heated to 200 ° C., and at the same time, 225 ° C. hot air is sucked into the hollow body through the intake hole 46 and exhausted through the exhaust hole 47. After the foaming resin composition layer is foamed and the foaming is completed, the cooling mold 5
The surface temperature of the outer layer was cooled to 60 ° C. according to 1 and a fiber-reinforced thermoplastic resin foam 52 having a core material layer expansion ratio of 4.7 times was molded at a molding speed of 1.2 m / min. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 52, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were obtained. The results are shown in Table 1.

Example 6 As a fibrous sheet, a continuous mat (basis weight 45) in which a continuous glass fiber bundle having a monofilament diameter of 9 μm was randomly oriented and held with an epoxy resin binder was used.
0 g / m @ 2, width 94.2 mm). As shown in FIG. 6, the apparatus for producing a fiber-reinforced thermoplastic resin foam includes a fibrous sheet feeder 55, an extruder 56 for extruding an expandable resin composition, a mold 57 for extruding an expandable resin composition, heating and cooling. It comprises a mold 58 and a take-up machine 59. When the fibrous sheet 61 passes from the U-shaped fibrous sheet insertion section 60 to the outlet of the foamable resin composition flow path 62, the foamable resin composition extrusion mold 57 is 57 is gradually formed into a tubular shape, and the end portion is abutted against each other to form a complete tubular shape. The portion where the fibrous sheet 61 does not become a complete tubular shape is a foamable resin composition. It is connected to an extruder 56 for extruding a product.

The flow path 62 of the foamable resin composition is
And a portion from which the fibrous sheet 61 is completely cylindrical to the portion where the fibrous sheet 61 is completely cylindrical.
The structure is such that the foamable resin composition can be extruded in a strand shape of m.

The heating / cooling mold 58 has a product sectional shape, and can be heated by a heater and cooled by passing water. Sectional Shape of Extruded Portion of Foamable Resin Composition of Mold 57 for Foamable Resin Composition Extrusion and Heating / Cooling Mold 58
Was a circle having a diameter of 30 mm.

The fibrous sheet 61 is inserted from the fibrous sheet insertion portion into the foaming resin composition extrusion die 57 adjusted to a temperature of 180 ° C. to form a hollow body in the die. (100 parts by weight of polyvinyl chloride, 2.5 parts by weight of a tin-based heat stabilizer, 1 part by weight of a lubricant, 12 parts by weight of an acrylic processing aid, 2 parts by weight of CaCO3, 2 parts by weight of dioctyl phthalate, sodium bicarbonate (foaming temperature: 175 5 ° C.) with a supermixer until the temperature reaches 100 ° C.
Extruder 56 for extruding a foamable resin composition.
After that, the mixture was supplied to the hollow inner surface while foaming at 185 ° C. through the flow path 62 of the mold 57.

After extruding the foamable resin composition, the foamed resin composition is introduced into a heating / cooling mold 58 connected to a mold 57 for extruding the foamable resin composition, and is formed into a continuous mat while continuing foaming in a heating section heated to 180 ° C. The foamed polyvinyl chloride was impregnated and pressed by a foaming pressure, and cooled to a surface temperature of 70 ° C. in a cooling unit cooled to 10 ° C. to obtain a fiber-reinforced thermoplastic resin foam 59A. The obtained fiber-reinforced thermoplastic resin foam is pressed against the heating / cooling mold surface and becomes a high-density glass fiber-containing polyvinyl chloride inside a surface layer made of a polyvinyl chloride foam core material layer. And the expansion ratio of the core material layer was 3.55 times.

The obtained fiber-reinforced thermoplastic resin foam 59
The flexural strength, flexural modulus and compressive strength of A, and the maximum, minimum and CV values of the thickness of the surface layer were measured in the same manner as in Example 1, and the results are shown in Table 1.

(Example 7) The same fibrous sheet 64 as in Example 5 was used. The manufacturing process used is shown in FIG. The foaming resin composition extrusion die 63 has the same structure as that of the fifth embodiment. Resin extrusion hole 6
The cross-sectional shape of the fibrous sheet forming path at the exit portion of No. 5 is a circle with a circumference of 109.9 mm, and the heating is connected to the foaming resin composition extrusion die 63 from the resin extrusion hole 65. It is narrowed down to a circular shape having a peripheral length of 92.4 mm by the cooling die 66, and is guided to a heating / cooling die 66 having a circular shape having a peripheral length of 92.4 mm.

As a foamable resin composition, 100 parts by weight of polyvinyl chloride, 2.5 parts by weight of a tin-based heat stabilizer, 0.6 parts by weight of a lubricant
Parts by weight, 3 parts by weight of an acrylic processing aid, 5 parts by weight of CaCO3, 1 part by weight of dioctyl phthalate, and 5 parts by weight of sodium bicarbonate (foaming temperature: 175 ° C) were stirred and mixed by a super mixer until the temperature reached 100 ° C. The fiber reinforced thermoplastic resin foam 6 was manufactured in the same manner as in Example 6 except that the above apparatus was used as the manufacturing apparatus.
7 was obtained. It has a two-layer structure having a core layer made of polyvinyl chloride foam inside a surface layer made of glass fiber-containing polyvinyl chloride pressed against the heating and cooling mold 66 and having a high density. Magnification was 3.73 times.

The obtained fiber-reinforced thermoplastic resin foam 67
The flexural strength, flexural modulus and compressive strength, and the maximum, minimum, and CV values of the thickness of the surface layer were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 8 A foamable resin composition was supplied from a foamable resin composition extruder to a hollow body surface at 165 ° C. while not foaming, and the temperature of a heating section of a heating and cooling mold was changed. Was set to 190 ° C., and except that the foamable resin composition was foamed, in the same manner as in Example 6,
A fiber-reinforced thermoplastic resin foam 59A was obtained. It has a two-layer structure having a core layer made of polyvinyl chloride foam inside a surface layer made of glass fiber-containing polyvinyl chloride pressed against a heating and cooling mold and having a high density. Was 2.10 times.

The obtained fiber-reinforced thermoplastic resin foam 59
The flexural strength, flexural modulus and compressive strength of A, and the maximum, minimum and CV values of the thickness of the surface layer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 9 A foamable resin composition was supplied from a foamable resin composition extrusion extruder to a hollow body surface at 162 ° C. while being not foamed. Was set to 190 ° C., and except that the foamable resin composition was foamed,
A fiber reinforced thermoplastic resin foam 67 was obtained. It has a two-layer structure having a core layer made of polyvinyl chloride foam inside a surface layer made of glass fiber-containing polyvinyl chloride pressed against a heating and cooling mold and having a high density. Was 2.0 times.

The obtained fiber-reinforced thermoplastic resin foam 67
The flexural strength, flexural modulus and compressive strength, and the maximum, minimum, and CV values of the thickness of the surface layer were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 10 As a powdery resin composition, 100 parts by weight of polyvinyl chloride, 1 part by weight of a tin-based heat stabilizer, polyethylene WAX 0.7
A fiber-reinforced thermoplastic resin sheet 128 was obtained in the same manner as in Example 1 except that a part consisting of parts by weight was used. FIG.
8 (a), a fiber reinforced thermoplastic resin foam was produced. The manufacturing apparatus has a rewinding roll 129 on which a fiber-reinforced thermoplastic resin sheet 128 is wound, and a cross section in front of the rewinding roll 129 having a shape as shown in FIGS. And slit members 130 and 131 having a through hole through which the fiber-reinforced thermoplastic resin sheet can pass, and the fiber-reinforced thermoplastic resin sheet 1
The heating roll 143 that heats the portion where the ends of the 28 overlap each other is disposed in front of the heating roll 143 so that the tip is bent forward at a right angle and a gap is provided between the mold 142 and the tip of the extruder 132. An extruder 132 for supplying the foamable resin composition; and a fiber-reinforced thermoplastic resin sheet 128.
Molds 142 and 145 that can shape the
The cross-sectional shape between the molds 142 and 145 is shown in FIG.
18 and a slit member 133 having a through hole through which the fiber-reinforced thermoplastic resin sheet 128 can pass, and a cross-sectional shape in front of the mold 145 is shown in FIG. A slit member 134 having a shape and having a through hole through which the fiber reinforced thermoplastic resin sheet 128 can pass, and further, in front of the slit member 134, the entrance cross-sectional shape is circular, and gradually changes. A mold 146 having an outlet cross-sectional shape of a rectangle having a width of 12 × a thickness of 90 mm, and a heating roll 135 for heating the other end of the fiber-reinforced thermoplastic resin sheet 128 in which the ends overlap each other;
It consists of heating molds 139 and 140 installed via a mold 146 and a heat insulating material 141, and the cross-sectional shape of the inlet is 12 ×
The heating mold 136 has a rectangular shape with a thickness of 90 mm, changes gradually, and has a cross-sectional exit shape shown in FIG.
In front of it, a cooling mold 138 having a cross-sectional shape corresponding to the exit cross-sectional shape of the heating mold 136 and a take-off device 144 are further provided via a heat insulating material 137.

The obtained fiber reinforced thermoplastic resin sheet 12
8 is rewound from the rewind roll 129, passed through the through holes of the slit members 130, 131, and the slit members 130, 131 overlap one end of the fiber-reinforced thermoplastic resin sheet 128, and the overlapped portion To
The mixture was heated to 200 ° C. with a heating roll 143 and fused. Further, a fiber-reinforced thermoplastic resin sheet 1 having one end fused thereto.
28 is inserted into a mold 142 maintained at 150 ° C., and cross-sections are formed by slit members 133 and 134, molds 145 and 146 maintained at 175 ° C., and a heating roll 135 maintained at 200 ° C. Shape is width 90 x thickness 12m
m was shaped into a rectangular hollow body. Polyvinyl chloride 1
00 parts by weight, tin-based heat stabilizer 2.5 parts by weight, lubricant 0.5 parts by weight, acrylic processing aid 8 parts by weight, CaCO3 3.5 parts by weight, dioctyl phthalate 2 parts by weight, sodium bicarbonate (foaming temperature 175 C.) A foamable resin composition consisting of 2.1 parts by weight was supplied to an extruder 132 and a resin temperature of 180 ° C.
While being foamed in the above, the inside of the hollow body was supplied. While maintaining the heating mold 136 at 180 ° C., the hollow body is shaped by the foaming pressure to complete the foaming, and the skin layer is cooled to 60 ° C. by the cooling mold 138, and the foaming ratio of the core material layer is reduced. A 2.5 times, fiber reinforced thermoplastic resin foam 147 was molded at a molding speed of 1.5 m / min. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 147, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were measured. The results are shown in Table 1.

Example 11 The procedure of Example 10 was repeated, except that polypropylene having an average particle size of 100 μm was used as the powdery thermoplastic resin.
A fiber-reinforced thermoplastic resin sheet 128 having 40% by volume of glass fiber was obtained, a gap between the mold 142 and the tip of the extruder 132 was eliminated, and a core member was provided at the center of the tip of the extruder. The temperature of the heating rolls 135 and 143 was maintained at 150 ° C., and the foamable resin composition (100 parts by weight of high-density polyethylene,
0 parts by weight, 40 parts by weight of silane crosslinkable polypropylene, 5 parts by weight of azodicarbonamide (foaming temperature 190 ° C.)
The mixture was supplied to a twin screw extruder having a diameter of 30 mm, melt-kneaded at a temperature of 170 ° C., extruded into a sheet having a width of 80 mm and a thickness of 3 mm, immersed in hot water at 100 ° C. for 1 hour, and dried. ) At 120 ° C., the heating mold 139 was maintained at 210 ° C., the heating mold 140 was maintained at 200 ° C., and the skin layer was cooled to 40 ° C. by the cooling mold 138. That the molding speed is 0.5 m / min
A fiber-reinforced thermoplastic resin foam 147 was obtained in the same manner as in Example 10 except that the above conditions were satisfied. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 147, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were measured. The results are shown in Table 1.

(Example 12) A composite sheet was prepared in the same manner as in Example 5, except that the width was 110 mm and both ends were adjusted so that the foamable resin composition layer was not laminated at 10 mm. 42A
I got Using the obtained two composite sheets 42A, FIG.
A fiber-reinforced thermoplastic resin foam 52 was obtained in the same manner as in Example 5, except that the hollow body was shaped as shown in FIG. Flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 52, the maximum value of the thickness of the surface layer,
The minimum value and CV value were measured in the same manner as in Example 2, and the results are shown in Table 1.

(Example 13) Instead of the fiber-reinforced thermoplastic resin sheet 128, the width 11
A fiber-reinforced thermoplastic resin foam was produced in the same manner as in Example 10 except that two 0 mm-sized fibrous sheets used in Example 6 were formed into a hollow body as shown in FIG. 147 was obtained. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 52, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were obtained. The results are shown in Table 1.

(Example 14) The foaming resin composition was supplied to the hollow body in a non-foamed state at a resin temperature of 165 ° C, the temperature of a heating mold was set to 195 ° C, foaming was started, and the foaming pressure was changed. A fiber-reinforced thermoplastic resin foam 52 was obtained in the same manner as in Example 13 except that the hollow body was shaped. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 52, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were obtained. The results are shown in Table 1. (Example 15) A powdery resin composition was composed of 100 parts by weight of an acetic acid-vinyl chloride copolymer (melt viscosity 1.7 × 10 5 poises), 2 parts by weight of a tin-based stabilizer, and 0.5 parts by weight of polyethylene WAX. 1.2 mm in thickness and 91 m in width in the same manner as in Example 1 except that the temperature of the heating furnace was set to 210 ° C.
m, a fiber-reinforced thermoplastic resin sheet 5 having a glass fiber content of 30% by volume.

The fiber reinforced thermoplastic resin sheet 5 is wound into a coil shape by a winder, but is transferred as it is to a rewind roll 81 of a fiber reinforced thermoplastic resin foam manufacturing apparatus shown in FIG. The fiber reinforced thermoplastic resin foam manufacturing apparatus includes a rewind roll 81, 100 parts by weight of chlorinated polyvinyl chloride, 2 parts by weight of dioctyltin mercapto-based heat stabilizer disposed in front of and on one side thereof, glycerin 2 parts by weight of monostearate lubricant, polyethylene W
AX1 part by weight, polymethyl methacrylate processing aid 5
A shaping mold 83 connected to an extruder 82 of a foamable resin composition, the shaping mold comprising 5 parts by weight, 5 parts by weight of CaCO 3, and 2.5 parts by weight of sodium bicarbonate (foaming temperature: 175 ° C.); An inner core 84 having a circular cross section that is fixed to the rear end of the inside of the die 83 and protrudes forward from the same die 83; and a heating vacuum forming device 85 that is arranged in front of the shaping die 83 in order from the rear.
A heating mold 86, a heat insulating material 87, a cooling mold 88, and a take-off machine 89 are provided.

The shaping die 83 has a U-shaped inlet and a circular outlet, and is deformed into a U-shape from the inlet to the outlet and inserted into the shaping die 83. The two edges of the fiber-reinforced thermoplastic resin sheet 5 are gradually approached to each other and finally the two edges are abutted to form a completely circular hollow body having an outer diameter of 29 mm and a thickness of 1.2 mm. . The extruder 82 is connected to the inner core 84 of the shaping die 83 at a position before the sheet 5 becomes completely hollow.
The inner core 84 protrudes from the front surface of the shaping die 83. The inner core 84 has an annular foamable resin composition passage 9 having an annular cross section.
0 is formed, which corresponds to the protrusion 8 of the inner core 84.
In FIG. 4 a, it opens in a trumpet shape toward the inner peripheral surface of the vacuum forming device 85. As the extruder 82, a single screw extruder having a diameter of 40 mm is used. The inner surface of the vacuum molding die 85 has the same circular shape as the outer diameter of the outlet of the shaping device 83 on the inlet side, but has a rectangular shape of 18 mm × 40 mm on the outlet side. And, from the outlet to the inlet, the inner surface becomes gradually rectangular from a circular shape, and the circumferential length thereof becomes gradually larger. The inner surfaces of the heating mold 86 and the cooling mold 88 both conform to the outlet shape of the vacuum forming device 85.

In the above apparatus, the fiber-reinforced thermoplastic resin sheet 5 unwound from the unwinding roll 81 is bent into a U-shape, inserted into the shaping mold 83, and inserted into the shaping mold 83.
The hollow body 91 is continuously formed into a hollow shape while being heated to 0 ° C. to form a hollow body 91. The hollow body 91 is introduced into a vacuum forming apparatus 85 heated to 180 ° C.
The foamable resin composition is sucked into the inner surface of the vacuum forming device 85 at a pressure of mmHg and shaped into a predetermined shape while the extruder 82
The resin is extruded at a resin temperature of 190 ° C., the foaming is started at the same time as the lamination, and then the foaming is introduced into a heating mold 86 while the foaming is completed while the resin temperature is kept at 180 ° C. The outer layer surface temperature was cooled to 60 ° C. to continuously obtain an 18 mm × 40 mm fiber-reinforced thermoplastic resin foam 94 having a rectangular cross section of 18 mm × 40 mm comprising a core layer 92 having a foaming ratio of 3.8 and a skin layer 93. Was. Molding speed 1.0
m / min.

The obtained fiber-reinforced thermoplastic resin foam 94
The bending strength, flexural modulus and compressive strength, and the maximum, minimum and CV values of the thickness of the surface layer 93 were measured in the same manner as in Example 2, and the results are shown in Table 1.

Example 16 As a foamable resin composition, 100 parts by weight of high-density polyethylene, 100 parts by weight of homopolypropylene, 40 parts by weight of silane crosslinkable polypropylene, and 5 parts by weight of azodicarbonamide (foaming temperature: 190 ° C.) It is supplied to a twin screw extruder having a diameter of 30 mm, and is melt-kneaded at 170 ° C.
A sheet having a thickness of 3 mm was immersed in hot water at 100 ° C. for 1 hour, and then dried. The foamable resin composition was extruded from an extruder 82 at a resin temperature of 170 ° C. without foaming. In the same manner as in Example 15, except that the foaming resin composition was foamed while the heating mold 86 was maintained at 220 ° C., the core material layer 92 and the skin layer 93 having a foaming ratio of 3.2 were formed. A 18 mm × 40 mm fiber-reinforced thermoplastic resin foam 94 having a rectangular cross section was continuously obtained. The bending strength, bending elastic modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 94, the maximum value, the minimum value and the CV value of the thickness of the surface layer 93 were measured by the same methods as in Example 2, and the results were as follows. Are shown in Table 1.

Example 17 Polypropylene (melt viscosity: 1.2 × 10 5 poises) was used as the powdery resin composition, and the temperature of the heating furnace was set to 210.
1 m in the same manner as in Example 15 except that
m, a width of 91 mm, and a fiber reinforced thermoplastic resin sheet 5 having a glass fiber content of 40% by volume. Further, 100 parts by weight of high density polyethylene, 15 parts by weight of silane crosslinkable polypropylene, 5 parts by weight of azodicarbonamide (foaming temperature 190 ° C.), glass fiber (filament diameter φ14, fiber length 5 m)
m) A foamable resin composition consisting of 10 parts by weight was supplied with a diameter of 30 m.
extruding while maintaining the resin temperature at 170 ° C. or lower by a twin-screw extruder having a thickness of 1 m to obtain a foamable resin composition sheet having a thickness of 1 mm.
Laminated and heat-sealed at 0 ° C., and a non-laminated portion of the foamable thermoplastic resin sheet is provided at one end with a length of 10 mm, and 1 mm
A 110 mm wide composite sheet 99 having a foamable thermoplastic resin layer and a 1 mm fiber reinforced thermoplastic resin layer was obtained.

The composite sheet 99 is wound in a coil shape by a winder in the same manner as in the case of Example 15, but is wound on a rewind roll 81 of a fiber-reinforced thermoplastic resin foam manufacturing apparatus shown in FIG. Transferred.

The apparatus for producing a fiber-reinforced thermoplastic resin foam is different from the apparatus shown in FIG. 10 in that an extruder does not exist.
The inner core 95 does not protrude forward from the shaping mold 83,
A silicon rubber pressing head 96 for pressing the hollow body 91 immediately before being introduced into the vacuum forming device 85 against the inner surface of the shaping die 83 is provided at the front end of the inner core 95 via a neck 97, and cooling. The apparatus is the same as the apparatus of FIG. 10 except that a cooling water spray nozzle 98 is built in the mold 88. The cooling water supply manifold 99 connected to the cooling water spray nozzle 98 is provided using a vacuum evacuation pipe. In the apparatus of FIG. 11, the same elements as those of the apparatus of FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted.

In the above apparatus, the composite sheet 99 unwound from the unwinding roll 81 is bent into a U-shape with the expandable thermoplastic resin layer inside, and inserted into the shaping mold 83. While heating to 170 ° C. to form a hollow body continuously to obtain an outer diameter of 29.0 mm and a thickness of 2
mm hollow body 91, and this hollow body 91
Introduced into the vacuum forming apparatus 85 heated to
A hollow body 91 is formed on the inner surface of the vacuum forming device 85 at 00 mmHg.
While suctioning and shaping, foaming of the inner foamable thermoplastic resin layer was started, and then the foamed thermoplastic resin layer was introduced into the heating mold 86 while foaming, and the foaming was completed by maintaining the resin temperature at 210 ° C. Thereafter, the outer layer surface temperature is cooled to 40 ° C. by a cooling mold 88, the molding speed is 1.5 m / min, and the core material layer 100 having a foaming ratio of 4 times and the skin layer 101 are 30 mm × 3.
0 mm cross section rectangular fiber reinforced thermoplastic resin foam 10
2 was obtained continuously. The flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were tabulated. 1 is shown.

(Embodiment 18) Instead of the pressing head 96, a ventilation hole is provided from the rear in the center of the inner core 95, and air is supplied from the ventilation hole to the inside of the tip of the shaping die 83, Internal pressure 0.2kg / cm2
Is generated, thereby forming the hollow body 91 into the shaping mold 83.
The inner surface was pressed, and then introduced into a vacuum forming device 85. The vacuum forming device 85 formed a circular hollow body into a 30 mm × 30 mm rectangular hollow body with a reduced pressure of 550 mmHg. The forming speed was 1.2 m / min. Except that
In the same manner as in Example 17, a fiber-reinforced thermoplastic resin foam having a foaming ratio of the core material layer of 3.5 was obtained. The flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were tabulated. 1 is shown.

(Example 19) The fiber-reinforced thermoplastic resin sheet was made of high-density polyethylene (melt viscosity: 1.4 × 10 5 poise) as the powdery resin composition, and the obtained fiber-reinforced thermoplastic resin was used. The sheet was manufactured in the same manner as in Example 15 except that the thickness of the sheet was adjusted to 0.5 mm. The content of glass fibers in the fiber-reinforced thermoplastic resin sheet was 40% by volume.
The fiber-reinforced thermoplastic resin sheet is integrated with the composite foamable sheet as described later, but the composite foamable sheet is not shown in FIG.
Was manufactured by the apparatus shown in FIG.

The apparatus shown in FIG. 12 includes a rewinding roll 104 on which a glass mat 103 is wound, and an upper and lower endless belt 1 disposed in front of the rewinding roll 104 and continuously moved.
And the endless belts 105a, 106 facing each other with a predetermined gap between the upper and lower endless belts 105, 106.
a heating furnace 107 maintained at 180 ° C. so that a can pass therethrough; a plurality of pairs of upper and lower pressure rolls 108 disposed in front of the heating furnace 107 and pressing the holding portions 105a and 106a; A vibrating device 109 disposed below the upper end transfer section 106b of the lower endless belt 106 and applying vibration thereto, and a powder 110 (100 parts by weight of high-density polyethylene,
After kneading a foamable resin composition comprising 15 parts by weight of silane crosslinkable polypropylene and 4 parts by weight of azodicarbonamide (foaming temperature 190 ° C.) at a resin temperature of 175 ° C. using a twin screw extruder having a diameter of 30 mm, and pelletizing the mixture, , Frozen and crushed,
Powder having a particle size of 100 μm or less) Supply hopper 1
11, an impeller 112 arranged at a discharge port of the hopper, for keeping the supply amount of the powder 110 constant, and a roller 113 opposed to the impeller 112 at a predetermined interval from the impeller, A plurality of inclined plates 114 are disposed between the hopper 111 and the transfer section 106b so as to be overlapped with a gap therebetween and to be inclined downward toward the falling line of the powder 110.

The composition of the glass mat used was glass fiber (fiber diameter: 7 to 17 μm, fiber length: 50 to 100 mm)
100 parts by weight and organic fiber (polyethylene, fiber diameter 30
μm, fiber length 50 mm) and 50 parts by weight. The molding condition is that the basis weight is 680 to 700 g.
/ Cm 2, needle type is needle type, # 32 (manufactured by Organ Needle), punch density is 60 to 70 points / cm 2, and punch depth is 9 to 10 mm. The weight of the foamable resin composition in the obtained composite foamable sheet was 40% by weight.

In this example, a fiber-reinforced thermoplastic resin foam was manufactured using the apparatus shown in FIG. The apparatus shown in FIG. 13 includes upper and lower rewind rolls 116 on which a fiber-reinforced thermoplastic resin sheet 115 having a thickness of 0.5 mm and a width of 458 mm is wound, and a thickness of 4 mm disposed behind the lower rewind roll 116. A rewind roll 125 on which a composite foamable sheet 117 having a width of 445 mm is wound, upper and lower far-infrared heaters 118 disposed in front of upper and lower rewind rolls 116, and rear heaters 118 are disposed in front of both heaters 118 in that order. Heating mold 119, heating vacuum forming apparatus 120,
A heating mold 121, a heat insulating material 122, a cooling mold 123, and a take-off machine 124 are provided.

Although not shown, a shaping plate for bending both sides of the upper and lower fiber reinforced thermoplastic resin sheets 115 into an L-shape in a direction facing each other is arranged behind the heating mold 119. The two fiber-reinforced thermoplastic resin sheets 115 are introduced into the heating mold 119 in a state where the composite foamable sheet 117 is placed inside the both sides while overlapping both edges of the thermoplastic resin sheet 115 by 4 mm while being aligned with the shaping plate. Width 45 as shown
It has a cylinder of 0 mm x 50 mm in length and has a constant pressure (1 k
g / cm @ 2) to integrate these sheets. Before insertion into the heating mold 119, both the fiber-reinforced thermoplastic resin sheets 115 are
By preheating to ° C., introduction into the heating mold 119 becomes easy. The temperature of the heating mold 119 is adjusted to 210 ° C., and at the front end of the heating mold 119, the speed of the foaming thermoplastic resin composition is adjusted so as to start foaming, and the plate-shaped hollow with a built-in composite foaming sheet is adjusted. By introducing the shaped body into the heating vacuum forming apparatus 120 and reducing the pressure with a vacuum pressure of 650 mmHg, the thickness of the foamed sheet is expanded from 5 mm to 12 mm in the composite foamed sheet built-in plate-shaped hollow body,
The foaming is completed by the heating die 121, the surface is brought into close contact with the inner surface of the cooling die 123 by the depressurizing force 720mmHg by the cooling die 123, and the surface is cooled down to a surface temperature of 50 ° C., whereby the expansion ratio is 2.1 times. Core layer 125 and skin layer 1
26, a plate-like fiber-reinforced thermoplastic resin foam 127 having a thickness of 12 mm and a width of 450 mm was obtained. Molding speed 80
cm / min. The flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were tabulated. 1 is shown.

Example 20 Three fiber-reinforced thermoplastic resin sheets 8a each having a thickness of 0.6 mm and a width of 60 mm were used, and when they were inserted into the shaping mold 83a shown in FIG. Inserted
A vent hole extending forward is provided in the center of the inner core 84, and air is supplied from the vent hole into the hollow body passing through the heating vacuum forming device 85 to generate an internal pressure of 0.3 kg / cm @ 2, The circular hollow body was formed into a rectangular hollow body of 18 mm × 40 mm by the forming device 85 under a reduced pressure of 400 mmHg, and the forming speed was 1.2 m / min.
A fiber-reinforced thermoplastic resin foam having a foaming ratio of 4.7 times the core material layer was obtained in the same manner as in Example 15 except that the above conditions were satisfied. Flexural strength of the obtained fiber-reinforced thermoplastic resin foam, flexural modulus and compressive strength, the maximum value of the thickness of the surface layer,
The minimum value and CV value were measured in the same manner as in Example 2, and the results are shown in Table 1.

(Example 21) When three fiber-reinforced thermoplastic resin sheets 8a having a width of 60 mm were used and inserted into the shaping mold 83a shown in FIG. An air hole extending forward is provided in the center of the inner core 84, and air is supplied from the air hole into the hollow body passing through the heating vacuum forming device 85 to 0.3 k.
g / cm @ 2, and at the same time, from a circular hollow body to a rectangular hollow body of 18 mm.times.40 mm by a vacuum forming device 85 under a reduced pressure of 400 mmHg. The forming speed was 1.2 m / min. Except having been described, the expansion ratio of the core material layer was 4.7 in the same manner as in Example 16.
A double fiber-reinforced thermoplastic resin foam was obtained. The flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam, the maximum value, the minimum value and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results were tabulated. 1
It was shown to.

Example 22 The composite sheet used in Example 12 was used.
A fiber-reinforced thermoplastic resin foam was obtained using the manufacturing apparatus shown in FIG. In the case similar to FIG. 18, the same numbers as those in FIG. 18 are used, and the description is omitted. Instead of the extruder 132, a hot air intake / exhaust 151 having a hot air intake hole 152 and a hot air exhaust hole 153 is used, and a heat insulating material 141 and a heating mold 136 are used.
A heating vacuum forming machine 149 is provided between
The inlet cross-sectional shape of 49 is a rectangle of width 12 × 90 mm, and is gradually changed, and the outlet cross-sectional shape is a shape shown in FIG. 18- F .
50, heating mold 136, vacuum forming mold 15
The manufacturing apparatus was the same as the apparatus for manufacturing a fiber-reinforced thermoplastic resin foam used in Example 10, except that the cross-sectional shape of No. 0 was a shape corresponding to the outlet shape of the heating vacuum forming machine. Instead of using the fiber-reinforced thermoplastic resin sheet 128, the composite sheet 148 used in Example 12 was used. Hot air at 210 ° C. was supplied to the inner surface of the hollow body from the hot air intake hole, and at the same time, the hot air exhaust hole 153 was used. Evacuation, maintaining the temperature of the molds 145 and 146 at 210 ° C., shaping the hollow body with a heating vacuum forming machine maintained at 200 ° C. at a pressure of 650 mmHg, The temperature of the mold was set to 200 ° C., and vacuum evacuation was performed with a vacuum cooling mold 150 at a pressure of 720 mmHg.
A fiber-reinforced thermoplastic resin foam 154 was obtained in the same manner as in Example 10, except that the skin layer was cooled to 40 ° C.
Flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 154, the maximum value of the thickness of the surface layer,
The minimum value and CV value were measured in the same manner as in Example 2, and the results are shown in Table 1.

Example 23 A core having an expansion ratio of 2.5 times was produced in the same manner as in Example 19, except that the hollow body was formed using one fiber-reinforced thermoplastic resin sheet having a width of 200 mm. A fiber reinforced thermoplastic resin foam having a material layer was obtained. Flexural strength, flexural modulus and compressive strength of the obtained fiber-reinforced thermoplastic resin foam 102,
The maximum value, the minimum value, and the CV value of the thickness of the surface layer were measured in the same manner as in Example 2, and the results are shown in Table 1.

Comparative Example 1 A composite was formed using the manufacturing apparatus shown in FIG. A foaming ratio of 3.5 times, obtained by extruding the foamable resin composition used in Example 1 as the core material 68,
A roving-like glass fiber bundle (4400 tex) made of a filament having a diameter of 23 μm is used above a core material 68 heated and softened to 170 ° C. A foamed material having an outer diameter of 26 mm and a length of 4000 mm is used. After passing through a resin liquid tank 70 filled with a liquid thermosetting resin (unsaturated polyester) from two directions below, the liquid is transferred through a plurality of alignment devices 71 and guided around the outer periphery of the core 68. On the other hand, while the nonwoven fabric (continuous mat of glass fiber) 72 is being unwound, the reinforcing fibers 69
These molding materials were fed to a pultruding mold 73 having a circular cross section having an inner diameter of 29 mm. Next, it was heated and cured at 180 ° C. in the molding die 73 to form a composite 74, and was taken up by a take-up machine 75.

The flexural strength, flexural modulus and compressive strength of the obtained composite 74, the maximum and minimum values of the thickness of the surface layer, and C
The V value was measured in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 The fibrous sheet used in Example 6 had a thickness of 0.3 mm.
What was melt-laminated between pressure rolls heated to 200 ° C. was used. The glass fiber content of the obtained glass fiber reinforced polyvinyl chloride sheet was 42% by volume, and the sheet thickness was 1.2 mm.

A foam was molded using the manufacturing apparatus shown in FIG. The production apparatus is an extruder 7 for extruding a foamable resin composition.
6, foaming resin composition extrusion mold 77, heating and cooling mold 7
8. It consists of a take-off machine 79. The foamable resin composition extrusion die 77 was provided with a flow path 80 having a diameter of 5 mm from the extruder 76, and had a structure in which the foamable resin composition was extruded from the flow path 80. This mold 77 has a heating / cooling mold 78 whose inner cross-sectional shape is a circle having a diameter of 27.5 mm.
Was attached. Mold for foaming resin composition extrusion 7
7, the foaming resin composition used in Example 6 was extruded while being foamed, foaming was completed in the heating portion of the heating / cooling mold 78, and was cooled and solidified in the cooling portion.
A 0x polyvinyl chloride foam was produced. The cross section of the obtained foam was a circle having a diameter of 27.5 mm. The above-mentioned glass fiber reinforced polyvinyl chloride sheet was adhered to the outside of this foam with a vinyl acetate adhesive in an emulsion state to obtain a composite foam composed of a fiber reinforced polyvinyl chloride layer and a foam layer.

The flexural strength, flexural modulus and compressive strength of the obtained composite foam, the maximum value, the minimum value and the CV value of the thickness of the fiber-reinforced polyvinyl chloride layer were measured in the same manner as in Example 1. The results are shown in Table 1. When measuring the bending strength of the composite foam, the fiber reinforced polyvinyl chloride layer and the foam layer were separated.

(Comparative Example 3) In the manufacturing apparatus used in Example 1, the fiber-reinforced thermoplastic resin sheet was not supplied, and the cross-sectional shape of the inlet was the same as that of the heating mold 11. Changed, the outlet cross section became a rectangle of 30 × 30 mm,
Using a cooling mold, a foam was produced in the same manner as in Example 1 except that the foam was rapidly cooled at 25 ° C. An unfoamed layer having a thickness of 1 mm was formed on the surface of the obtained foam. The flexural strength, flexural modulus and compressive strength of the foam obtained, the maximum value, the minimum value and the CV value of the surface layer thickness were measured in the same manner as in Example 2, and the results are shown in Table 1.

[0133]

[Table 1]

[0134]

The constitution of the present invention is as described above, and it is not necessary to prepare a preformed foam, so that the productivity is excellent and the hollow body is shaped by the foaming pressure. Therefore, thickness unevenness of the skin layer formed of the hollow body is less likely to occur, and a uniform fiber-reinforced thermoplastic resin foam having rigidity or the like can be obtained.

Since the skin layer and the core layer are made of a thermoplastic resin and are shaped by foaming pressure, they can be formed into a desired shape in the manufacturing process, and fiber reinforced having a complicated cross-sectional shape can be formed. A thermoplastic resin foam can be obtained. Since the resin used is a thermoplastic resin, it can be remolded and recycled.

Further, the foaming resin foaming pressure causes the foaming resin in the molten state to push the hollow body from inside with a uniform force, so that the surface layer and the core material layer are fused. Since it is integrated, there is no weak fusion part at the interface between the surface layer and the core material layer, and a fiber-reinforced thermoplastic resin foam with uniform rigidity quality such as bending strength is obtained. Can be.

When the composite sheet is used, gas generated from the foamable resin composition remains at the interface between the skin layer and the core material layer, and the surface layer of the resulting fiber-reinforced thermoplastic resin foam and the core material The generation of voids between the layer and the layer can be prevented.

When a fibrous sheet is used, the foamable resin composition foams and the resin is impregnated between the fibers of the fibrous sheet. Therefore, it is necessary to produce a fiber-reinforced thermoplastic resin sheet or the like in advance. Since it is not provided, the process can be omitted.

In the inventions according to claims 3 to 5 and claim 8 ,
Since the hollow body is shaped by foaming pressure or / and pneumatic molding, a fiber-reinforced thermoplastic resin foam having a more complex cross-sectional shape can be manufactured more accurately than when only foaming pressure is used. be able to.

As the fiber-reinforced thermoplastic resin sheet, a sheet in which a large number of continuous fibers are oriented and shaped into a hollow body so that the continuous fibers are in the longitudinal direction can be obtained by pulling out the hollow body while removing the fiber-reinforced thermoplastic resin sheet. A plastic foam can be manufactured, and productivity can be improved.

According to the eighth aspect of the present invention, the thickness of the foamable sheet in the hollow body is expanded when the foamable fiber-reinforced thermoplastic resin composition is heated and foamed and pneumatically molded. As a result, the fiber-reinforced thermoplastic resin foam excellent in compressive strength can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin sheet used in Example 1.

FIG. 2 is a schematic cross-sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 1.

FIG. 3 is a schematic cross-sectional view of a device for manufacturing a fiber-reinforced thermoplastic resin sheet used in Example 3.

FIG. 4 (a) shows the results obtained in Example 4;
It is a cross section of an apparatus for manufacturing a fiber-reinforced thermoplastic resin foam. FIG. 4B is a sectional view taken along the arrow 4 (B) -4 (B) of the shaping mold in FIG. 4 (A).

FIG. 5 (a) is a cross-sectional view used in Example 5.
It is a cross section of an apparatus for manufacturing a fiber-reinforced thermoplastic resin foam. FIG. 5B is a cross-sectional view taken along line 5 (B) -5 (B) of the heating mold in FIG. FIG.
FIG. 5C is a sectional view of the heating mold taken along line 5 (c) -5 (c) in FIG. FIG. 5D is a cross-sectional view of a hollow body obtained by forming an elliptical shape using a composite sheet at the entrance of a heating mold.

FIG. 6 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 6.

FIG. 7 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 7.

FIG. 8 is a schematic cross-sectional view of a composite manufacturing apparatus used in Comparative Example 1.

FIG. 9 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Comparative Example 2.

FIG. 10 is a schematic sectional view of a fiber-reinforced thermoplastic resin foam manufacturing apparatus used in Example 15.

FIG. 11 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 17.

FIG. 12 is a schematic sectional view of an apparatus for manufacturing a composite foamable sheet used in Example 19.

FIG. 13 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 19.

FIG. 14 is a cross-sectional view of the heating mold taken along line 14-14 in FIG.

FIG. 15 is a sectional view of the heating mold taken along line 15-15 in FIG.

FIG. 16 is a sectional view taken along arrow 16-16 in FIG. 13;

FIG. 17 is a partial cross-sectional view of a shaping mold of the apparatus for manufacturing a fiber-reinforced thermoplastic resin sheet used in Example 20.

FIG. 18 (a) is a schematic cross-sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 10. FIG. 18B is a cross-sectional view of the state in which the fiber-reinforced thermoplastic resin sheet is inserted into the slit member 130. FIG. 18C is a cross-sectional view of the slit member 131 in which a fiber-reinforced thermoplastic resin sheet is inserted. FIG. 18D is a cross-sectional view of the state in which the fiber-reinforced thermoplastic resin sheet is inserted into the slit member 133.
FIG. 18E is a cross-sectional view of the state in which the fiber-reinforced thermoplastic resin sheet is inserted into the slit member 134. FIG.
8 (f) is a cross-sectional view of the exit portion of the heating mold 140.
FIG. 18G is a cross-sectional view of the hollow body at the entrance of the heating mold.

FIG. 19 is a cross-sectional view of a hollow body at the entrance of a heating mold of Example 12.

FIG. 20 is a sectional view of a hollow body at the entrance of a heating mold of Example 18.

FIG. 21 is a schematic sectional view of an apparatus for producing a fiber-reinforced thermoplastic resin foam used in Example 22.

[Explanation of symbols]

5, 25E, 29A, 115, 128 Fiber reinforced thermoplastic resin sheet 15, 39 Foamable resin composition 16, 41, 52, 59A, 67, 94, 102, 12
7, 147, 154 fiber-reinforced thermoplastic resin foam 42A, 99, 148 composite sheet 61, 64 fibrous sheet 91 hollow body 117 composite foamable sheet 11, 32, 48, 58, 66, 136, 85, 86,
120, 121, 136, 149
(Hollow shaped) Mold

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29K 105: 04 105: 08 B29L 9:00 31:10 (56) References JP-A-52-58771 (JP, A) JP-A JP-A-4-216923 (JP, A) JP-A-55-71531 (JP, A) JP-A-3-161318 (JP, A) JP-A-4-27532 (JP, A) JP-A-5-16253 (JP) JP-A-62-181137 (JP, A) JP-A-59-140034 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 44/00-44/60 B29C 67/20 B29C 70/00-70/56 B32B 1/06 B32B 5/00-5/32

Claims (8)

(57) [Claims] 1. A step of continuously forming one or a plurality of fibrous sheets into a hollow body, wherein a foamable resin composition containing a thermoplastic resin and a foaming agent is foamed on the inner surface of the hollow body. A method for producing a fiber-reinforced thermoplastic resin foam, comprising the steps of: feeding the mixture while forming the hollow body into a desired shape by foaming pressure. 2. A step of continuously shaping one or a plurality of fibrous sheets into a hollow body, and supplying a foamable resin composition containing a thermoplastic resin and a foaming agent to the inner surface of the hollow body. And
A method for producing a fiber-reinforced thermoplastic resin foam, comprising a step of heating the foamable resin composition to a temperature equal to or higher than the foaming temperature of a foaming agent and shaping the hollow body into a desired shape by foaming pressure. 3. A step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets into a hollow body, a step of pneumatically forming the hollow body into a predetermined cross-sectional shape, and A fiber-reinforced thermoplastic material comprising a step of foaming and supplying a foamable resin composition containing a thermoplastic resin and a foaming agent to an inner surface thereof, and shaping the hollow body into a desired shape by foaming pressure. A method for producing a resin foam. 4. A step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets into a hollow body, a step of pneumatically forming the hollow body into a predetermined cross-sectional shape, and On the inner surface, a foamable resin composition containing a thermoplastic resin and a foaming agent is supplied, and the foamable resin composition is heated to the foaming temperature of the foaming agent or more, and the hollow body is shaped into a desired shape by foaming pressure. A method for producing a fiber-reinforced thermoplastic resin foam, comprising the steps of: 5. A hollow sheet is continuously provided with one or more composite sheets comprising a fiber-reinforced thermoplastic resin layer and a foamable resin composition layer so that the fiber-reinforced thermoplastic resin layer becomes an outer surface. Shaping, pneumatically forming the hollow body into a predetermined cross-sectional shape, and foaming the foamable resin composition layer and shaping the hollow body into a desired shape by foaming pressure. For producing a fiber-reinforced thermoplastic resin foam. 6. A step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets in which a large number of continuous fibers are oriented into a hollow body so that the continuous fibers extend in the longitudinal direction. Supplying a foamable resin composition containing a thermoplastic resin and a foaming agent to the inner surface of the hollow body while foaming the foamed body. A method for producing a fiber-reinforced thermoplastic resin foam, comprising a step of shaping the fiber into a desired shape. 7. A step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets in which a large number of continuous fibers are oriented into a hollow body so that the continuous fibers are in the longitudinal direction. A step of supplying a foamable resin composition containing a thermoplastic resin and a foaming agent to the inner surface of the hollow body, heating the foamable resin composition to a foaming temperature of the foaming agent or higher, A method for producing a fiber-reinforced thermoplastic resin foam, comprising a step of shaping the hollow body into a desired shape by foaming pressure while extracting the hollow body. 8. A step of continuously forming one or a plurality of fiber-reinforced thermoplastic resin sheets into a hollow body, wherein the hollow body contains a thermoplastic resin in a mat-like material containing fibers as a main component. Supplying a composite foamable sheet impregnated with a foamable resin composition containing a decomposable foaming agent, and integrating with a hollow body, and a hollow body integrated with the composite foamable sheet. By air-forming and heating the foamable resin composition above the foaming temperature of the foaming agent, the hollow body
A method for producing a fiber-reinforced thermoplastic resin foam, comprising the step of: expanding the thickness of the composite foamable sheet in the above .