JPH06320670A - Laminated molded form and molding method therefor - Google Patents

Abstract

(57) [Summary] [Objective] To provide a laminated molded article of a fiber reinforced thermoplastic resin having improved mechanical properties and appearance, and a molding method thereof. [Structure] Lamination molding in which a thin metal plate is laminated on the surface of a porous fiber-reinforced thermoplastic resin layer made of a non-woven material by a paper-making method of reinforcing fibers and a thermoplastic resin via a hot-melt type adhesive resin layer Goods. A thin metal plate is laid on the surface of the non-woven material by a papermaking method via a hot-melt type adhesive resin film, heated to a melting point or a softening point of the thermoplastic resin or higher, and the thermoplastic resin is pressed in a molten state, A method for forming a laminated molded article, which comprises decompressing, expanding a nonwoven material by springback of reinforcing fibers, and thereafter press-molding and cooling-molding the formed laminated body to an expanded thickness or less. [Effect] The uniform expansion of the fiber-reinforced thermoplastic resin layer and the surface portion being laminated and reinforced by the metal thin plate exhibit good mechanical properties. Further, since the non-woven material is constrained at the resin-rich interface with the plate-like body and expands, the surface of the plate-like body is transferred and a good appearance can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated molded product using a fiber reinforced thermoplastic resin porous molded product.
INDUSTRIAL APPLICABILITY The laminated molded article of the present invention can be widely used for vehicle members, materials for construction / civil engineering, etc. for which wood has been conventionally used.

[0002]

2. Description of the Related Art In recent years, due to global environmental problems, the cutting of South Sea timber has been regarded as a problem. Nanyo wood is processed into plywood and is used in large quantities in vehicle parts, construction and civil engineering materials, etc.
The development of alternative materials is desired.

As a wood substitute, a fiber-reinforced thermoplastic resin molded product composed of a relatively long reinforcing fiber and a thermoplastic resin has the characteristics that it is relatively lightweight and has high strength.
It is attracting attention because it has rigidity. But,
Fiber-reinforced thermoplastic resin molded product has a density of 1 to 1.3 g / cm
³ is not lighter than 0.5-0.7 g / cm ³ of wood plywood, and in order to discover the same level of strength and rigidity as wood plywood, it leads to an increase in product weight and This will lead to higher costs.

As a method for improving the mechanical properties and reducing the weight of a fiber-reinforced thermoplastic resin molded product, a papermaking method (Japanese Patent Publication No.
No. 2-12283, Japanese Patent Publication No. 55-9119)
According to the method for producing a porous molded article using a sheet-shaped molding material (JP-A-60-179234, JP-A-62-1).
No. 61529) has been proposed. This porous molded product is molded by utilizing the sheet expansion that occurs when the sheet-shaped molding material is heated to the softening point or melting point of the thermoplastic resin which is the matrix before molding.

The sheet-shaped molding material is produced by applying a papermaking technique to uniformly disperse reinforcing fibers having a diameter of 3 to 30 μm and a length of 3 to 50 mm and a thermoplastic resin powder to produce a non-woven material. It is manufactured by using the material as a raw material, heating, pressurizing, and further cooling. The non-woven material produced by the papermaking method has a property that it is very bulky because the reinforcing fibers are dispersed in the state of monofilaments (single fibers). The thickness of the non-woven material varies depending on the content of reinforcing fibers, its shape, and papermaking conditions, but is about 10 times as thick as that of a sheet from which voids are generally used as a sheet-shaped forming material. The heating of the sheet-shaped molding material weakens the binding force of the thermoplastic resin to the reinforcing fibers, so that the residual stress of the reinforcing fibers is released, and the sheet-shaped molding material expands due to the springback to return to the original state. Insert the expanded sheet-shaped molding material into the mold, set a clearance within the thickness of the expanded sheet, and set a clearance within the range to leave the enclosing space, and pressurize and cool under the conditions to obtain the desired expansion ratio. By molding, a porous molded product can be manufactured.

Although the strength and elastic modulus per area of the porous molded product are lowered due to expansion, the molded product can be made thicker with a constant weight, and the flexural strength of the molded product is determined by the material thickness. Since the bending rigidity is proportional to the cube of the thickness of the molded product, the mechanical properties can be improved and the weight can be reduced as compared with the ordinary fiber-reinforced thermoplastic resin molded product.

However, the porous molded article molded by the above method is not sufficient in mechanical properties and appearance of the molded article as described below. An example of a conventional method for molding a porous molded article is shown in FIG. The sheet-shaped molding material 14 is generally heated in the far-infrared heating furnace 15 above the softening point or melting point of the thermoplastic resin. The expansion of the sheet-shaped molding material is
Starting from the surface of the sheet to be heated first, the heat gradually expands as the heat reaches the center of the plate thickness. However, due to the expansion, a heat insulating air layer is formed inside the seat,
The thermal conductivity decreases. This decrease in thermal conductivity causes uneven sheet expansion. The sheet-shaped molding material expands greatly in the vicinity of the surface (16), but since the heat from far infrared rays is not sufficiently transferred to the inside of the sheet, a layer (17) that is hardly expanded inside is formed. It

Since the sheet-shaped molding material expands under no load, unevenness 18 is formed on the surface. The unevenness of the surface part is
This occurs because the reinforcing fibers in the sheet-shaped molding material are randomly oriented and springback occurs unevenly in the sheet. Further, on the sheet surface, the reinforcing fibers are exposed by spring back (19), and the appearance is significantly deteriorated.

The expanded sheet material is inserted into the cooling press platen 13, and the clearance is set to be equal to or less than the thickness of the expanded sheet and a range for leaving an enclosed void is set,
Press and cool and mold under the conditions to obtain the desired expansion ratio,
The porous molded product 20 is manufactured.

The expanded state of the porous molded product is large near the surface like the sheet-shaped molding material and the inside is hardly expanded. Therefore, when the product is bent, the surface portion to which tensile and compression loads are applied is The structure becomes mechanically weak and mechanical properties deteriorate. Furthermore, since the appearance of the molded product inherits the appearance of the heating sheet, wrinkles 21 are generated due to the unevenness of the sheet surface, and the appearance is deteriorated due to the exposure 19 of the reinforcing fibers.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a laminated molded product of a fiber reinforced thermoplastic resin having improved mechanical properties and appearance, which is useful as a wood substitute or the like, and a molding method thereof.

[0012]

The gist of the present invention is as follows. (1) A thin metal plate is laminated on the surface of a porous fiber-reinforced thermoplastic resin layer made of a non-woven material by a paper-making method of reinforcing fibers and a thermoplastic resin, with a hot-melt type adhesive resin layer interposed therebetween. Characteristic laminated moldings. (2) The apparent density of the porous fiber-reinforced thermoplastic resin is
The laminated molded product according to the above (1), which has a content of 0.3 to 1 g / cm ³ .

(3) A thin metal plate is laminated on the surface of a non-woven material composed of reinforcing fibers and a thermoplastic resin by a papermaking method with a film of a hot melt type adhesive resin interposed therebetween, and the melting point or softening point of the thermoplastic resin or more is exceeded. Heat and pressurize in the molten state of the thermoplastic resin, then remove the pressure while the thermoplastic resin remains in the molten state, expand the nonwoven material by springback of the reinforcing fibers, and then form A method for forming a laminated molded article, which comprises press-molding the formed laminated body to an expanded thickness or less, and cooling.

An example of the laminated molded article of the present invention and its molding method is shown in FIG. In the laminated molded article 1 of the present invention, the porous fiber-reinforced thermoplastic resin layer 2 and the metal thin plate 3 are hot-melt type adhesive resin layers (hereinafter referred to as adhesive resin layers).
4, and the fiber-reinforced thermoplastic resin layer preferably has an apparent density of 0.3 to 1 g / cm ³ .

Since the fiber-reinforced thermoplastic resin layer is uniformly expanded and the intersecting portions of the reinforcing fibers 5 are efficiently adhered by the thermoplastic resin 6, excellent mechanical properties can be obtained. Furthermore, the surface portion of the fiber-reinforced thermoplastic resin layer exhibits more excellent mechanical properties because the metal thin plates that are firmly bonded by the adhesive resin layer are laminated and reinforced. The metal sheets are laminated on one side or both sides depending on the application and desired properties.

An adhesive resin film 8 and a metal thin plate 3 are superposed on the surface of a non-woven material 7 made of a reinforcing fiber 5 and a thermoplastic resin 6 produced by a papermaking method, and a plate-like body having smooth surfaces on both sides thereof. 9 are piled up and inserted in the heating press board 10 and heated until the thermoplastic resin is melted. After the thermoplastic resin is heated until it is melted, the thermoplastic resin is impregnated between the reinforcing fibers, so that pressure is applied at a pressure that does not cause fiber breakage (11). Subsequently, the pressure is removed while the thermoplastic resin is still molten, the nonwoven material is expanded by the springback of the reinforcing fibers (12), and the plate-shaped members are cooled in the stacked state. It is inserted into the press board 13 and the clearance is set to be equal to or less than the thickness of these expanded laminates and set to a range in which voids included in the fiber reinforced thermoplastic resin layer are left, and the expansion ratio desired is obtained. The laminated molded product 1 of the present invention is manufactured by pressure-molding, cooling-molding, and removing the plate-shaped body.

In the molding method of FIG. 1, the heating, pressurizing step and the pressurizing and cooling steps were carried out by separate dedicated press machines, but heating, pressurizing, depressurizing and cooling molding were carried out by one press machine. You can also do it. In addition, preheating the non-woven material for the purpose of shortening the heating time of the non-woven material on the hot press machine is preferable because it shortens the molding cycle. For the preheating of the non-woven material, there is used a method of passing hot air for heating in a short time by utilizing air permeability of the non-woven material, or heating by an oven.

When a sheet-shaped molding material obtained by heating, pressurizing and cooling the non-woven material is used instead of the non-woven material,
Similarly, expansion of the reinforcing fibers due to springback occurs, and the laminated molded product of the present invention can be obtained. However, in this case, the entire process becomes long due to the forming process of the sheet-shaped forming material, which is not efficient. Since the laminated molded product molded by this method has an unstable peripheral shape, it can be actually manufactured by trimming the periphery of the molded product.

The expansion ratio of the non-woven material varies depending on the type (rigidity) of the reinforcing fibers and the content thereof, because it is caused by the springback of the reinforcing fibers, but is about 5 times at maximum. Therefore, the degree of porosity of the fiber-reinforced thermoplastic resin layer is such that the apparent density is in the range of 0.3 to 1 g / cm ³ ,
Determined by use.

The reinforcing fibers used as the raw material for the non-woven material include:
In addition to glass fibers, carbon fibers, and metal fibers, inorganic fibers, organic fibers, and a mixture thereof may be used depending on the application.
The shape of the reinforcing fiber is preferably 3 μm or more from the viewpoint of easy handling and economical, and 30 μm or less in order to express sufficient strength, and the fiber length is 3 mm or more from the viewpoint of strength development, and is uniform. It is desirable to set the thickness to 50 mm or less, which allows various dispersion. Reinforcing fiber is a water-soluble polymer for improving hydrophilicity for the purpose of good dispersion in water, a wetting agent, and silane coupling for improving adhesiveness with thermoplastic resin for the purpose of developing strength. With agents,
It is desirable to perform surface treatment.

The thermoplastic resin is polyethylene, polypropylene, polystyrene, styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polyamide, polycarbonate, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, polyphenylene sulfide. Such as a plasticizer, a heat stabilizer, a light stabilizer, a filler, and the like, which also include a mixture of two or more of these resins.
It is also possible to add dyes and pigments, impact resistance agents, extenders, nucleating agents, processing aids and the like. The shape of the thermoplastic resin is appropriately selected from pellets, powders, flakes, and fibrous shapes.

The content of the reinforcing fiber is 10% by volume or more at which stable expansion by springback occurs, and 40% by volume or less at which the reinforcing fiber and the thermoplastic resin can be bonded and mechanical properties are sufficiently exhibited. Is desirable.

The adhesive resin is used in the form of a film from the viewpoint of handleability, is melted when the nonwoven material is heated, and is fixed by cooling molding to the fiber-reinforced thermoplastic resin layer and the metal thin plate. Examples of the adhesive resin include polyolefins graft-modified with unsaturated carboxylic acids or their derivatives (acid anhydrides, esters, amides, imides, metal salts, etc.), such as polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer. Polymers, ethylene-acrylic ester copolymers, ethylene-based resins such as ethylene-acrylic acid copolymers, polypropylene, propylene-based resins such as propylene-ethylene copolymers, and hydrocarbon elastomers (butyl rubber, etc.) The thing added can be mentioned. The film of the adhesive resin is appropriately selected from these, taking into consideration the compatibility and melting point of the thermoplastic resin used for the fiber-reinforced thermoplastic resin.

As the thin metal plate, a steel plate, a stainless steel plate, an aluminum plate, a copper plate, a brass plate or the like can be used, and the thickness thereof is not particularly limited, but the preferable range is 0.01 to 10 mm depending on the application. Select appropriately.
Further, it is also possible to use those obtained by subjecting the surface of these metal thin plates to uneven processing such as a decorative pattern.

As the plate-like member, the same one as in the manufacturing process of the sheet-shaped forming material is used. The sheet-shaped molding material is formed by stacking plate-shaped bodies having smooth surfaces on both sides of a non-woven material, heating the thermoplastic resin to the melting point or softening point or higher, and then pressing the thermoplastic resin between the reinforcing fibers. It is manufactured by impregnation and further cooling. The material of the plate-shaped body may be any material as long as it can withstand the heating temperature, and examples thereof include those made of metal, inorganic material and resin. These plate-like bodies must have a property that the thermoplastic resin adheres in the molten state but does not adhere in the non-melted state, and is coated with Teflon resin or the like in consideration of the releasability of the sheet-shaped molding material. Alternatively, a release agent treatment such as silicon may be performed.

The heating of the non-woven material is carried out by contact heating of a temperature-controlled heating press machine under a very small pressure which does not damage the reinforcing fibers even when the thermoplastic resin is solidified. The thermoplastic resin of the non-woven material gradually melts from the outside, but the distance between the plate-like bodies (thickness of the non-woven material) decreases accordingly, and uniform heating is performed. Then, in a state where the thermoplastic resin of the non-woven material is melted, the thermoplastic resin is impregnated between the reinforcing fibers, so that pressurization is performed at a pressure that does not cause fiber breakage. Further, the pressure is removed while the thermoplastic resin is molten. Since the reinforcing fibers are dispersed in the state of monofilament (single fiber) in the non-woven material, the nonwoven material is largely expanded by spring back. Also, since the nonwoven material is heated uniformly, a uniform expansion is obtained. The expanded laminated body is inserted into a cooling press machine in a state where the plate-like body is superposed on the expanded laminated body, clearance is set to obtain an intended expansion ratio, pressurization and cooling molding are performed, and a fiber-reinforced thermoplastic resin layer is formed. After the expanded state is frozen, the plate-shaped body is removed to form the laminated molded article of the present invention.

The pressure impregnation of the non-woven material improves the wettability of the reinforcing fibers and the thermoplastic resin. Therefore, when the fiber-reinforced thermoplastic resin layer is uniformly expanded, the intersecting portions of the reinforcing fibers are efficiently made of the thermoplastic resin. Adhered and the mechanical properties of the fiber reinforced thermoplastic layer are improved.

On the side where the metal thin plate of the non-woven material and the film of the adhesive resin are laminated, the thermoplastic resin in the non-woven material oozes out to the interface with the metal thin plate during pressurization and is stable together with the adhesive resin. The resin-rich layer is formed, and both are firmly adhered. Similarly, even on the side where the thin metal plate and the film of the adhesive resin are not laminated, the thermoplastic resin oozes out to the interface with the plate-like body at the time of pressurization to form a resin-rich layer and firmly adhere them to each other. . Therefore, the non-woven material expands in a state of being constrained to the surfaces of the metal thin plate and the plate-like body, a good adhesive strength is obtained with the metal thin plate, and even on the surface of the molded product where the metal thin plates are not laminated, After the sheet is removed, the surface of the plate is transferred, and a good resin-rich smooth surface is obtained.

In the molding method of FIG. 1, the plate-like bodies are superposed on both sides of the laminated body. However, since the metal thin plates play the role of plate-like bodies on the surface where the metal thin plates are laminated, steps such as handling property are performed. If there is no problem above, it is not necessary to stack the plate-shaped bodies. In addition, as described above, when heating, pressurizing, decompressing, and cooling forming are performed by one press machine, the role of the plate-shaped body can be fulfilled by the press board, so that the metal thin plates are laminated. It is also possible to omit the use of the plate-shaped body even on the surface of the laminated body which is not formed.

Since the laminated molded article of the present invention has good mechanical properties and appearance, it can be widely applied as an excellent wood substitute to industrial materials in which wood has been conventionally used. .

[0031]

The present invention will be described in detail with reference to the following examples. Example 1 A glass fiber having a diameter of 10 μm and a length of 13 mm as a reinforcing fiber and a spherical pellet having a diameter of 3 mm as a thermoplastic resin were mechanically crushed, and the crushed product was sieved to 70 mesh (opening diameter 0.212 mm) to 10 mesh (opening). Glass fiber content of 45% by weight (22.3% by volume) by a papermaking method using polypropylene resin powder classified to a diameter of 1.7 mm)
A non-woven material having a composition of 55% by weight (77.7% by volume) of polypropylene resin and a basis weight (weight per area) of 1200 g / m ² was produced.

The non-woven material is cut into 600 × 600 mm and 5
One laminated polypropylene sheet, one side of which is a modified polypropylene resin film (thickness: 35 μm) grafted with maleic anhydride as an adhesive resin film, and a steel plate (thickness: 0.2 mm) 1
The sheets were stacked. Further, a stainless steel end plate having a smooth surface as a plate-like body was superposed on both sides of this laminated body to form the laminated molded article of the present invention. Stack 210
Inserted in a heating press board whose temperature is set to ℃, pressure 2kg
The non-woven material was preheated under a pressure of f / cm ² for about 7 minutes until the temperature of the central portion of the non-woven material increased to 190 ° C. or higher. At this temperature, the polypropylene resin was sufficiently molten. Then, pressure 5kg
Press at f / cm ² for 1 minute, insert the laminated body into a cooling press board, set the clearance of the press board with a spacer, pressurize at 5 kgf / cm ² for about 5 minutes, and cool-mold. After molding, the end plate was removed to obtain a laminated molded product having a plate thickness of 10 mm and a fiber-reinforced thermoplastic resin layer having an apparent density of 0.62 g / cm ³ .

After heating and pressurizing, the laminate immediately expanded due to the springback of the reinforcing fibers in a short time when it was moved from the heating plate to the cooling plate. In addition, it was confirmed that the non-woven material after heating and pressurizing, the steel plate and the end plate were very firmly in contact with each other, and the surface of the non-woven material was expanded while being constrained by both surfaces.

The steel sheet of the laminated molded product was firmly adhered to the expanded fiber-reinforced thermoplastic resin layer. In addition, a stable resin-rich layer was formed on the surface where the adhesive resin film and the steel plate were not laminated, the glass fiber was not exposed, and the smooth surface of the end plate was transferred to give a good appearance.

By observation with an optical microscope and a scanning electron microscope,
It was confirmed that the crossing portions of the glass fibers in the fiber reinforced thermoplastic resin layer were efficiently adhered by the polypropylene resin and uniform expansion was performed. A test piece with a width of 70 mm and a length of 200 mm was sampled from this laminated molded product, and a span of 150 was obtained.
A 3-point bending test of mm was performed. The results are shown in Table 1.

Example 2 The nonwoven material of Example 1 was cut into pieces of 600 × 600 mm and laminated on five sheets, and the adhesive resin film and the steel plate used in Example 1 were laminated on both sides of the sheet, respectively. In the same manner as in Example 1, the laminated molded product of the present invention (the apparent density of the fiber-reinforced thermoplastic resin layer was 0.66 g / cm ³ ) was molded.

Example 3 The nonwoven material of Example 1 was cut into pieces of 600 × 600 mm and laminated on four sheets, and on both sides thereof, a film of the adhesive resin used in Example 1 and a steel plate were laminated, respectively, In the same manner as in Example 1, the laminated molded product of the present invention (the apparent density of the fiber-reinforced thermoplastic resin layer was 0.51 g / cm ³ ) was molded.

Example 4 The non-woven material of Example 1 was cut into 600 × 600 mm and laminated on three sheets, and one film of the adhesive resin used in Example 1 and one steel plate were laminated on both sides thereof, In the same manner as in Example 1, the laminated molded product of the present invention (the apparent density of the fiber-reinforced thermoplastic resin layer was 0.39 g / cm ³ ) was molded.

Example 5 The nonwoven material of Example 1 was cut into pieces of 600 × 600 mm and laminated on five sheets, and the film of the adhesive resin used in Example 1 and an aluminum plate (thickness: 0.2 mm) were laminated on both sides thereof. One sheet of each was laminated to form a laminated molded article of the present invention (the apparent density of the fiber-reinforced thermoplastic resin layer was 0.66 g / cm ³ ) in the same manner as in Example 1.

The laminated molded articles of Examples 2, 3, 4, and 5 were obtained by firmly bonding the steel plate and the aluminum plate to the expanded fiber-reinforced thermoplastic resin layer, and intersecting the glass fibers in the fiber-reinforced thermoplastic resin layer. It was confirmed that was efficiently adhered with polypropylene resin and that uniform expansion was performed.
A test piece having a width of 70 mm and a length of 200 mm was sampled from these laminated molded articles and subjected to a three-point bending test with a span of 150 mm.
The results are shown in Table 1.

Comparative Example 1 The non-woven material of Example 1 was cut into 600 × 600 mm, 7 sheets were laminated, and a stainless steel end plate as a plate-like body was laminated on both surfaces thereof to remove voids. Was molded.
The laminated body was inserted into a heating press platen whose temperature was set to 210 ° C., and preheated under a pressure of 2 kgf / cm ² for about 7 minutes until the temperature of the central part of the nonwoven material increased to 190 ° C. or higher. .
Then, pressurizing at a pressure of 5 kgf / cm ² for 1 minute, and further inserting the laminated body into a cooling press machine, and applying a pressure of 5 kgf / cm ² for about 5 minutes.
A plate-shaped molded product was molded by applying pressure and cooling for minutes. In this case, the clearance of the press platen was not set, and the non-woven material was cooled and molded in the state of being directly pressed, as in the heating and pressing. After cooling, the end plate is removed and the plate thickness is 6.8 mm.
A plate-shaped molded product of

The surface of the plate-shaped molded product was rich in resin and the glass fiber was not exposed, and the plate-shaped molded product had a good appearance. It was also confirmed that the reinforcing fibers inside the molded product were uniformly dispersed, and the thermoplastic resin was sufficiently impregnated between them. A test piece having a width of 70 mm and a length of 200 mm was sampled from this molded product and subjected to a three-point bending test with a span of 150 mm. The result
The results are shown in Table 1.

Comparative Example 2 An expansion molded product was molded by a conventional method using the plate-shaped molded product molded in Comparative Example 1 as a molding material. The molding material was heated in a far infrared heating furnace for about 7 minutes until the surface temperature rose to 210 ° C. At this time, the molding material was greatly expanded in the vicinity of the surface, and the inside was not sufficiently heated.
Further, it was confirmed that unevenness was generated on the surface portion and the glass fiber was exposed by spring back. Insert the heated molding material into the cooling press machine, set the clearance of the press machine with the spacer, and press the pressure 5kgf / cm ²
After pressurizing and cooling for about 5 minutes, an expansion molded product having a plate thickness of 10 mm was obtained.

Since the appearance of the expansion-molded product inherits the appearance of the heated molding material, wrinkles due to surface irregularities and deterioration of the appearance due to the exposure of the reinforcing fibers occur. In addition, the expansion state inside the expansion molded product is very large near the surface,
It was confirmed that the central part did not expand much like the original molding material. This center layer was about 50% of the initial thickness of the molding material and had a thickness of 3.3 mm. A test piece having a width of 70 mm and a length of 200 mm was sampled from this expansion-molded product and subjected to a three-point bending test with a span of 150 mm. The results are shown in Table 1.

[0045]

[Table 1]

In the laminated molded article of the example, since the fiber reinforced thermoplastic resin layer in which the glass fibers are efficiently adhered by the polypropylene resin is uniformly expanded and the surface portion is laminated and reinforced by the metal thin plate, , Excellent mechanical properties were obtained. The strength and elastic modulus per area are lower than those of the non-expanded molded product of Comparative Example 1, but the bending strength (bending load) and bending rigidity (elastic gradient) of the product are improved. . Bending gradient is a three-point bending test,
It is the load when the amount of deflection of the test piece is 1 mm and serves as an index of the rigidity of the molded product. This result is because the bending strength is proportional to the square of the plate thickness of the molded product and the bending rigidity is proportional to the cube of the plate thickness, and it has been confirmed that the rigidity is remarkably improved.

The expansion-molded product of Comparative Example 2 had a structure in which the expansion in the vicinity of the surface was very large, and the central part had hardly expanded. Therefore, when the product is bent, the surface portion to which a tensile or compressive load is applied has a mechanically weak structure, and sufficient mechanical properties cannot be obtained. Although the basis weights of the molded products of Example 3 and Comparative Examples 1 and 2 are almost the same, the laminated molded product of the present invention is very excellent in bending strength and rigidity as compared with the conventional molded product.

[0048]

In the laminated molded article of the present invention, the fiber-reinforced thermoplastic resin layer in which the reinforcing fibers are efficiently adhered by the thermoplastic resin is uniformly expanded, and the surface portion is laminated by the metal thin plate.
Good mechanical properties are developed due to the strengthening.
Further, since the non-woven material is constrained at the resin-rich interface with the plate-like body and expands, a resin-rich molded product appearance in which the surface of the plate-like body is transferred can be obtained. The laminated molded article of the present invention is an excellent substitute for wood without impairing the lightness,
It can be widely applied to industrial materials.

[Brief description of drawings]

FIG. 1 is a schematic view showing a laminated molded article of the present invention and a molding method thereof.

FIG. 2 is a schematic view showing an example of a conventional method for molding an expansion molded product.

[Explanation of symbols]

1 Laminated article of the present invention 2 Porous fiber reinforced thermoplastic resin layer 3 Metal thin plate 4 Hot melt type adhesive resin layer 5 Reinforcing fiber 6 Thermoplastic resin 7 Nonwoven material 8 Hot melt type adhesive resin film 9 Plate shape Body 10 Heating press machine 11 Non-woven material pressed in a molten state of thermoplastic resin 12 Non-woven material uniformly expanded by spring back of reinforcing fibers 13 Cooling press machine 14 Sheet-shaped molding material 15 Far infrared heating furnace 16 Expanded layer 17 Almost non-expanded layer 18 Unevenness of sheet surface 19 Exposure of reinforcing fiber by springback 20 Porous molded product 21 Wrinkled surface of molded product

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[Procedure amendment]

[Submission date] July 9, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

In the molding method of FIG. 1, the plate-like bodies are superposed on both sides of the laminated body. However, since the metal thin plates play the role of plate-like bodies on the surface where the metal thin plates are laminated, steps such as handling property are performed. If there is no problem above, it is not necessary to stack the plate-shaped bodies. The heating by single pressing machine as described above, pressure, Kai圧, when carrying out the cooling molding, plate
Since the press machine plays the role of a sheet, thin metal plates are stacked.
It is also possible to omit the use of the plate-shaped body even on the surface of the laminated body which is not formed.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Kimura 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Petrochemical Co., Ltd. Yokkaichi Research Institute

Claims (3)

[Claims] 1. A thin metal plate is laminated on the surface of a porous fiber-reinforced thermoplastic resin layer made of a non-woven material produced by a paper-making method of reinforcing fibers and a thermoplastic resin, with a hot-melt type adhesive resin layer interposed therebetween. A laminated molded product characterized by the above. 2. The laminated molded article according to claim 1, wherein the apparent density of the porous fiber-reinforced thermoplastic resin is 0.3 to 1 g / cm ³ . 3. A thin metal plate is superposed on the surface of a non-woven material composed of reinforced fibers and a thermoplastic resin by a paper-making method with a film of a hot-melt type adhesive resin interposed therebetween, and is heated above the melting point or softening point of the thermoplastic resin. Then, the thermoplastic resin is pressed in the molten state, and then the pressure is removed while the thermoplastic resin remains in the molten state, and the nonwoven material is expanded by the springback of the reinforcing fiber, and then formed. A method for forming a laminated molded article, which comprises subjecting the laminated body to pressure expansion cooling or less and cooling-molding.