JPH0516277A - Laminated molded article and its molding method - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Porous laminated molded article 9 with good appearance using the fiber-reinforced thermoplastic resin sheet molding material 1 produced by the papermaking method.
And a molding method thereof. [Structure] The core portion is a fiber-reinforced thermoplastic resin layer having a reinforcing fiber content of 10% by volume or more produced by a paper-making method, and is expanded using a spring pack by releasing residual stress of the reinforcing fiber at the time of heating, thereby forming a thermoplastic resin porous layer. A laminated molded product in which a fiber-reinforced thermoplastic resin layer obtained by laminating a decorative skin having a quality sheet 7 laminated on the core portion and press-molding the void has a volume of 5 to 75% by volume. [Effect] Since the fiber-reinforced thermoplastic resin layer of the core portion is covered with the decorative skin, it exhibits very excellent appearance characteristics. Moreover, since the thermoplastic resin porous sheet 7 functions as a cushioning material, the feel is also excellent. Adhesion between the core portion and the skin is performed by fusing the thermoplastic resin porous sheet 7, and good adhesive strength is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous laminated molded article using a fiber reinforced thermoplastic resin and a molding method thereof. The porous laminated molded article according to the present invention is an interior material for automobiles, or housing parts such as household electric appliances,
Widely used for industrial parts such as furniture.

[0002]

2. Description of the Related Art Recently, there has been a tendency that industrial parts manufactured by pressing metal are replaced by press-molded products of fiber-reinforced thermoplastic resin composed of relatively long reinforcing fibers and thermoplastic resin. is there. The characteristic of the fiber-reinforced thermoplastic resin is that a sheet-shaped molding material of heated fiber-reinforced thermoplastic resin (hereinafter, the molding material is referred to as a sheet-shaped molding material)
A complicated molded product can be manufactured by inserting into a molding die heated at room temperature or heated and press-molding in a short time.
Furthermore, the molded product has high strength and is lightweight. Furthermore, since the rigidity of the porous molded product obtained by expanding the fiber-reinforced thermoplastic resin is remarkably strengthened as the product thickness increases, the merit of weight reduction is improved.

A method for producing a porous molded article by heat-molding a fiber-reinforced resin sheet obtained by the paper-making method to expand and expand the matrix into the shape of the mold by the stress applied to the fiber (JP-A-60-179234). Japanese Patent Laid-Open Publication No. 62-161529).

Sheet-shaped molding materials are produced by applying papermaking technology.
A non-woven material is produced by uniformly dispersing reinforcing fibers having a diameter of 3 to 30 μm φ and a length of 3 to 50 mm and a thermoplastic resin powder, and the non-woven material is used as a raw material for heating, pressurizing and cooling. It is manufactured (Japanese Patent Publication No. 52-12283 and Japanese Patent Publication No. 55-9119).

The non-woven material produced by the paper-making method has the property that it is very bulky because the reinforcing fibers are dispersed in the state of monofilaments (single fibers) and are randomly oriented. 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 sheet-shaped molding material is heated before the softening point or melting point of the thermoplastic resin that is the matrix before molding, but the binding force of the thermoplastic resin to the reinforcing fibers is weakened, so that the residual stress of the reinforcing fibers is released.
It expands due to the spring back trying to return to the original.

A porous molded article is molded by utilizing the expansion of this sheet-shaped molding material. The sheet-shaped molding material is generally heated in a far-infrared heating furnace, but the heated sheet-shaped molding material that is expanded at that time is inserted into the molding die and pressure-molded under the condition that the desired expansion ratio is obtained. By doing so, a porous molded article is manufactured.

FIG. 1 shows an example of a method for molding a porous molded article.
It is shown in (a). The sheet-shaped molding material 1 is heated in the far infrared heating furnace 2. The sheet-shaped molding material expands by heating, and the exposure 3 of the reinforcing fibers due to springback increases on the surface of the sheet. The porous sheet material 6 is obtained by inserting the heated sheet-shaped forming material 4 into the forming die 5 and pressurizing the sheet-shaped forming material 4 under the condition of obtaining a desired expansion ratio. However, in this case, the deterioration of the appearance of the porous molded article is caused by inheriting the poor appearance due to the exposure of the reinforcing fibers of the heating sheet-shaped molding material.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a porous laminated molded article having a good appearance and a molding method using a sheet-shaped molding material manufactured by a papermaking method.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a decorative skin in which a core portion is a fiber-reinforced thermoplastic resin layer having a reinforcing fiber content of 10% by volume or more by a papermaking method, and a thermoplastic resin porous sheet is laminated. A laminated molded product in which a fiber-reinforced thermoplastic resin layer laminated on the core part and subjected to heat and pressure molding has voids of 5 to 75% by volume, and a fiber reinforcement having a reinforcing fiber content of 10% by volume or more by a papermaking method. The thermoplastic resin layer is used as the core part, and is expanded by utilizing the spring back by releasing the residual stress of the reinforcing fiber at the time of heating, and the decorative outer skin laminated with the thermoplastic resin porous sheet is laminated on the core part, for molding. The fiber-reinforced thermoplastic resin layer is characterized by being integrally molded by pressure molding using a mold.
This is a method for forming a laminated molded product having voids of 75% by volume.

An example of the method for molding the laminated molded article of the present invention is shown in FIG. 1 (b). Similar to FIG. 1A, the sheet-shaped molding material 1 is heated in the far infrared heating furnace 2. Then, the decorative skin 8 laminated with the thermoplastic resin porous sheet 7 is laminated on the heated sheet-shaped molding material 4, inserted into the molding die 5, and pressed under the condition that a desired expansion ratio is obtained. A porous laminated molded product 9 is obtained by molding and integrating at the same time.

Adhesion between the fiber-reinforced thermoplastic resin layer at the core of the porous laminated molded article and the laminated skin is melted by the heat of the sheet-shaped molding material in which the thermoplastic resin porous sheet is heated, It is carried out by fixing to the fiber reinforced thermoplastic resin layer by cooling of. Therefore, it is necessary to previously bond the decorative surface skin and the thermoplastic resin porous sheet forming the surface skin by heat fusion or the like. In the present invention, a laminate material of the decorative surface skin and the thermoplastic resin porous sheet is used.

Since the surface of the porous laminated molded article obtained by the present invention is completely covered with the decorative skin which is laminated with the thermoplastic resin porous sheet, it has very excellent appearance characteristics. Further, since the porous thermoplastic resin sheet acts as a cushioning material, the feel is also excellent.

In FIG. 1 (b), the outer appearance is improved by laminating a decorative skin in which a thermoplastic resin porous sheet is laminated on one side of the porous molded article, but depending on the intended use of the molded article. It is also possible to improve the appearance by laminating a decorative skin in which a thermoplastic resin porous sheet is laminated on both sides of the porous molded article. In the molding method of the present invention, the molding of the porous molded product and the decoration with the skin are performed at the same time, so that the steps can be omitted.

As the decorative surface skin, woven cloth made of natural and synthetic fibers as a breathable material, non-woven fabric obtained by needle punching, raised woven cloth, knitted cloth, flocked cloth, etc. Alternatively, a plastic sheet (or film) having a textured finish such as cloth or leather pattern, a plastic sheet (or film) mixed with metal powder, or coated with metal is used.

The thermoplastic resin porous sheet needs to be appropriately selected in view of compatibility with the thermoplastic resin used for the fiber reinforced thermoplastic resin layer, melting point and the like. Typical examples of the thermoplastic resin porous sheet are polyethylene foam, ethylene-propylene copolymer foam, and ethylene-vinyl acetate copolymer foam. It also includes a mixture of two or more of these, further comprising a plasticizer, a heat stabilizer,
Light stabilizers, fillers, dyes and pigments, impact resistance agents, extenders, nucleating agents,
Processing aids and the like can also be added. The thickness and expansion ratio of the thermoplastic resin porous sheet are determined by the needs of the product, but the thickness is 1 to 10 mm and the expansion ratio is 1
0 to 50 times is desirable.

The fiber content of the fiber-reinforced thermoplastic resin layer of the core in the present invention is 10% by volume or more at which stable expansion due to spring-back of the reinforcing fibers occurs, and the bonding between the reinforcing fibers and the thermoplastic resin is possible. It is desirable that the content of the fiber-reinforced thermoplastic resin is 40% by volume or less, which is sufficient for developing strength as a porous molded article.

As the reinforcing fibers, inorganic fibers and organic fibers are used in addition to glass fibers, carbon fibers and metal fibers. The shape of the reinforcing fiber is preferably 3 μm φ or more in diameter from the viewpoint of easy handling and economical, and 30 μm φ or less to express sufficient strength, and the fiber length is 3 mm from the viewpoint of strength development. As described above, it is desirable that the thickness is 50 mm or less, which allows uniform dispersion. The reinforcing fiber is a water-soluble polymer for improving hydrophilicity for the purpose of good dispersion in water, a wetting agent, and a silane coupling agent for improving adhesiveness with the thermoplastic resin for expressing strength. For example, it is desirable to perform surface treatment.

The thermoplastic resin is polyethylene, polypropylene, polystyrene, styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polyamide, polycarbonate, poacetal,
Resins such as polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, polyphenylene sulfide, etc., and also including mixtures of two or more of these, plasticizers, heat stabilizers, light stabilizers commonly used in these It is also possible to add agents, fillers, dyes and pigments, impact resistance agents, extenders, nucleating agents, processing aids and the like.

The porosity of the porous molded product is determined by the expansion ratio of the sheet-shaped molding material during heating and the conditions of pressure molding. To take advantage of the weight saving of porous molded products,
It is desirable to increase the porosity, but it is necessary to sufficiently bond the reinforcing fibers with a thermoplastic resin in order to express the strength, and the porosity of the porous molded article of the present invention is 5 to 7
5% by volume. It is preferably 30 to 70% by volume.

An example of the manufacturing process of the sheet-shaped molding material by the papermaking technique is shown in FIG. Diameter 3 μm φ ~ 30 μm φ,
A reinforcing fiber 10 such as a glass fiber having a length of 3 mm to 50 mm and a thermoplastic resin powder 11 are continuously put into water in a dispersion tank 12. In the dispersion tank, stirring is performed in order to uniformly disperse the reinforcing fiber and the resin powder, and the dispersion liquid is supplied by the pump 13 to the head box 15 installed above the mesh belt conveyor 14. A negative pressure is maintained in the wet box 16 installed on the lower side of the head box, and the dispersion liquid in the head box is continuously sucked and dehydrated to form a composite in which the reinforcing fibers and the thermoplastic resin powder are uniformly dispersed. The woven material 17 is produced. This non-woven material is dried by a hot air dryer 18 of a ventilation type, and at the same time, a part or all of the thermoplastic resin is heated to a temperature above its softening point or melting point to be melted and cooled to make the reinforcing fiber thermoplastic. Non-woven material bonded with resin. Further, heating and pressurization is performed by a double belt conveyor type continuous press 19, further cooling and forming into a sheet, and finally reeling up 20 or according to the dimensions required for heating and pressurizing. The sheet-shaped molding material 1 is manufactured by cutting it into a shape with a cutter 21.
As the sheet-shaped molding material, it is possible to provide a material in which voids are present in addition to a material in which voids in the sheet are completely removed when a nonwoven material is subjected to continuous double-belt conveyor press molding.

In the sheet-shaped molding material used in the present invention, it is desirable that the reinforcing fibers are dispersed to a monofilament state in order to exhibit stable expansion due to springback of the reinforcing fibers and to exhibit good strength. In the present invention,
The sheet-shaped molding material used is the one manufactured by the wet method by the paper-making technology, but the dry method (directly mixing or stirring the reinforcing fiber and the thermoplastic resin powder to disperse, and then heat-press molding According to the method for producing a sheet-shaped molding material), it can be applied depending on the dispersed state of the reinforcing fibers.

[0022]

The present invention will be described in detail below with reference to examples. Example 1 A glass fiber having a diameter of 10 μm φ and a length of 13 mm as a reinforcing fiber and a spherical pellet having a diameter of 3 μm φ as a thermoplastic resin were mechanically crushed, and the crushed product was sieved to 70 me.
sh (opening diameter 0.212 mm) to 10 mesh (opening diameter 1.7)
mm) using polypropylene resin powder classified to
A non-woven material having a composition of glass fiber content of 50% by weight (26.0% by volume) and polypropylene resin of 50% by weight (74.0% by volume) and a basis weight of 2500 g / m ² was produced by a papermaking method.

A sheet-shaped molding material having a plate thickness of 1.9 mm was manufactured by hot press molding using one piece of this nonwoven material. As for the molding conditions for hot press molding, preheating is 210 ° C.
At no load for 5 minutes, then pressure 20 Kgf / cm ²
Was pressed for 5 minutes, cooled and solidified to form a sheet.

Using the sheet-shaped molding material and a 0.5 mm thick polyvinyl chloride film laminated with a 3 mm polyethylene foam (melting point: 116 ° C., expansion ratio: 15 times), the method shown in FIG. To form a porous laminated molded article. The sheet-shaped molding material is cut into 15 × 15 cm, heated in a far infrared heating furnace until the surface temperature reaches 210 ° C., and then laminated so that the foam comes into contact with the heated sheet-shaped molding material, It was inserted into a mold whose temperature was controlled at 40 ° C., and press-molded at a pressure of 10 Kgf / cm ² to form a porous laminated molded product. The expansion ratio of the fiber-reinforced thermoplastic resin layer of the molded product (thickness of the fiber-reinforced thermoplastic resin layer / thickness of the sheet-shaped molding material) is adjusted to 1.5 times by adjusting the cavity of the mold with the spacer (porosity 33 volume). %)
Was set.

Example 2 Using the same sheet-shaped molding material and decorative skin as in Example 1, a porous laminate molded article having an expansion ratio of 2 times (porosity 50% by volume) was molded by the same method. Example 3 Using the same sheet-like molding material and decorative skin as in Example 1, a porous laminated molded article having an expansion ratio of 3 times (porosity 66% by volume) was molded by the same method. Example 4 Using the same sheet-shaped molding material and decorative skin as in Example 1, a porous laminated molded article having an expansion ratio of 4 times (porosity 75% by volume) was molded by the same method.

Example 5 The same sheet-like molding material as in Example 1 and a 0.5 mm thick polyvinyl chloride film laminated with 3 mm ethylene-propylene copolymer foam (melting point 135 ° C., expansion ratio 15 times) for decorative skin. Was used to form a porous laminated molded article having an expansion ratio of 2 times (porosity 50% by volume) in the same manner.

Comparative Example The same sheet-shaped molding material as in Example 1 was used, but the expansion ratio was 1.5 times (porosity 3
(3% by volume) to form a porous laminated molded article. The appearance of the molded articles of the examples and comparative examples and the adhesive strength between the fiber reinforced thermoplastic resin layer and the skin of the molded articles of the examples were measured by a 90-degree peeling test and are shown in Table 1.

[0028]

[Table 1]

The surface of the porous laminate molded article of the example had a very good appearance because it was completely covered with the polyvinyl chloride film. In addition, the feel of the foam was excellent because the foam worked as a cushioning material. On the other hand, the appearance of the porous molded article of Comparative Example was found to be deteriorated due to the exposure of the glass fiber.

In the examples, it was confirmed that the skin was sufficiently adhered to the fiber reinforced thermoplastic resin layer. This is because the foam melted by the heat of the heated sheet-shaped molding material and solidified by cooling during molding, and good adhesion was achieved. In the peeling test, since the foam peeled while being damaged, much foam remained on the peeled surface after the test.

As the expansion ratio of the molded product increases,
Although the adhesive strength between the fiber-reinforced thermoplastic resin layer and the epidermis tends to decrease, it was confirmed that the epidermis is adhered even at an expansion ratio of 4 times (porosity 75% by volume). The expansion ratio of the laminated molded product was set by changing the thickness of the cavity of the mold with a spacer. As the expansion ratio increases, the cavity thickness increases and the molding pressure decreases. When the molding pressure is lowered, the glass fiber is exposed, the amount of the melted foam resin penetrated into the surface layer portion of the fiber reinforced thermoplastic resin is reduced, and the anchor effect is lowered. The residual amount of the foamed material was remarkably reduced on the release surface of the porous laminated molded product having an expansion ratio of 4 times. Good appearance and adhesive strength were also obtained in the porous laminated molded product of Example 5 in which the foam was changed.

[0032]

EFFECTS OF THE INVENTION According to the present invention, a good appearance can be obtained in a porous laminated molded product using a sheet-shaped molding material manufactured by a papermaking method. Further, as a molding method, the molding of the porous molded product and the decoration with the skin are performed at the same time, so that the steps can be omitted. The present invention can be used for general hot pressing, but also has beneficial results in pneumatic molding.

[Brief description of drawings]

1A and 1B are schematic views showing an example of a molding process of a porous molded product and a porous laminated molded product.

FIG. 2 is a schematic view showing an example of a manufacturing process of a sheet-shaped molding material by a papermaking technique. 1 Sheet-shaped molding material 2 Far infrared heating furnace 3 Reinforcement fiber exposure by springback 4 Heated sheet-shaped molding material 5 Mold 6 Porous molded product 7 Thermoplastic resin porous sheet 8 Decorative skin 9 Porous laminated molding Item 10 Reinforcing fiber 11 Thermoplastic resin powder 12 Dispersion tank 13 Pump 14 Mesh belt conveyor 15 Head box 16 Wet box 17 Non-woven material 18 Hot air impression machine 19 Double belt conveyor type continuous press 20 Reel up, 21 Cutter.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 20, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

An example of the manufacturing process of the sheet-shaped molding material by the papermaking technique is shown in FIG. Diameter 3 μm φ ~ 30 μm φ,
A reinforcing fiber 10 such as a glass fiber having a length of 3 mm to 50 mm and a thermoplastic resin powder 11 are continuously put into water in a dispersion tank 12. In the dispersion tank, stirring is performed in order to uniformly disperse the reinforcing fiber and the resin powder, and the dispersion liquid is supplied by the pump 13 to the head box 15 installed above the mesh belt conveyor 14. A negative pressure is maintained in the wet box 16 installed on the lower side of the head box, and the dispersion liquid in the head box is continuously sucked and dehydrated to form a composite in which the reinforcing fibers and the thermoplastic resin powder are uniformly dispersed. The woven material 17 is produced. This non-woven material is dried by a hot air dryer 18 of a ventilation type, and at the same time, a part or all of the thermoplastic resin is heated to a temperature above its softening point or melting point to be melted and cooled to make the reinforcing fiber thermoplastic. Non-woven material bonded with resin. Further, heating and pressurization is performed by a double belt conveyor type continuous press 19, further cooling and forming into a sheet, and finally reeling up 20 or according to the dimensions required for heating and pressurizing. The sheet-shaped molding material 1 is manufactured by cutting it into a shape with a cutter 21.
As the sheet-shaped molding material, there can be provided a material in which voids are present in addition to a material in which voids in the sheet are completely removed when the nonwoven material is molded by the double belt conveyor continuous press .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

A sheet-shaped molding material having a plate thickness of 1.9 mm was manufactured by hot press molding using one piece of this nonwoven material. As for the molding conditions for hot press molding, preheating is 210 ° C.
For 5 minutes with no load, then pressure 20 kgf / cm ²
Was pressed for 5 minutes, cooled and solidified to form a sheet.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

Using the sheet-shaped molding material and a 0.5 mm thick polyvinyl chloride film laminated with a 3 mm polyethylene foam (melting point: 116 ° C., expansion ratio: 15 times), the method shown in FIG. To form a porous laminated molded article. The sheet-shaped molding material is cut into 15 × 15 cm, heated in a far infrared heating furnace until the surface temperature reaches 210 ° C., and then laminated so that the foam comes into contact with the heated sheet-shaped molding material, The porous laminated molded article was molded by inserting it into a mold whose temperature was adjusted to 40 ° C. and press-molding it at a pressure of 10 kgf / cm ² . The expansion ratio of the fiber-reinforced thermoplastic resin layer of the molded product (thickness of the fiber-reinforced thermoplastic resin layer / thickness of the sheet-shaped molding material) is adjusted to 1.5 times by adjusting the cavity of the mold with the spacer (porosity 33 volume). %)
Was set.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

[0028]

[Table 1]

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

As the expansion ratio of the molded product increases,
Although the adhesive strength between the fiber-reinforced thermoplastic resin layer and the epidermis tends to decrease, it was confirmed that the epidermis is adhered even at an expansion ratio of 4 times (porosity 75% by volume). The expansion ratio of the laminated molded product was set by changing the thickness of the cavity of the mold with a spacer. As the expansion ratio increases, the cavity thickness increases and the molding pressure decreases. The decrease in molding pressure is due to the fiber strength of the exposed glass fiber.
Of the molten foam resin that penetrates into the surface layer of the
The amount is reduced and the anchor effect is reduced. The residual amount of the foamed material was remarkably reduced on the release surface of the porous laminated molded product having an expansion ratio of 4 times. Good appearance and adhesive strength were also obtained in the porous laminated molded product of Example 5 in which the foam was changed.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

1A and 1B are schematic views showing an example of a molding process of a porous molded product and a porous laminated molded product.

FIG. 2 is a schematic view showing an example of a manufacturing process of a sheet-shaped molding material by a papermaking technique.

[Explanation of symbols] 1 Sheet-shaped molding material 2 Far infrared rays
Furnace 3 Exposure due to springback of reinforcing fibers 4 Heated sheet material 5 Mold 6 Porous molding
Goods 7 Thermoplastic resin porous sheet 8 Decorative skin 9 Porous laminated molding 10 Reinforcing fiber 11 thermoplastic resin powder 12 dispersion tank 13 pump 14 mesh
Belt conveyor 15 headbox 16 wet
box 17 Non-woven material 18Hot air drying
Machine 19 Double belt conveyor type continuous press 20 reel up, 21 cutter
-.

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

Claims (2)

[Claims] 1. The core has a reinforcing fiber content of 10 produced by a papermaking method.
A fiber reinforced thermoplastic resin layer formed by laminating a decorative skin, in which a thermoplastic resin porous sheet is laminated with a volume% or more of the fiber reinforced thermoplastic resin layer, on the core portion, and heat-pressing the laminate. Laminated molded product having voids of 75% by volume. 2. The content of reinforcing fiber by the papermaking method is 10% by volume.
Using the fiber-reinforced thermoplastic resin layer as the core, the spring is expanded by residual stress release of the reinforcing fiber at the time of heating, and a decorative skin laminated with a thermoplastic resin porous sheet is laminated on the core. Then, the method for molding a laminated molded article, in which the fiber-reinforced thermoplastic resin layer has voids of 5 to 75% by volume, which is integrated by pressure molding using a molding die.