JPS6320687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite molded article made of a thermoplastic resin and a method for producing the same, and particularly to an object in which a large number of partially modified resin strips are bundled and integrated.

Conventionally, in the case of molded products in which a large number of resin strips are extruded and bundled together, if two types of resin strips are bundled outside the mold, they tend to be insufficiently fused together, making it difficult to bundle them together. was.

In other words, with in-mold bonding, two types of resins meet in the high temperature region inside the mold, and the resins are completely melted to form a fusion bond, and because they are under pressure, a strong bond can be obtained. Therefore, in the case of bonding outside the mold, although the resin itself is in a softened state in the contact area, the temperature is lower than that inside the mold, and this is because the pressure has been released once it is discharged into the atmosphere. , the bonding force inevitably becomes weaker. In addition, in the case of foam, the temperature drops when it is discharged from the mold and foams, which further weakens the adhesion.

The aim of this invention is to strengthen the bonding between different resins by fusion. In other words, a large number of resin strips are gathered outside the mold and the individual strips are joined together using the so-called outside-mold bonding method, while different resins are joined inside the mold and bonded under high temperature and pressure. We are trying to achieve the same bonding strength as the so-called in-mold bonding method.

First, the composition of the composite molded article according to the present invention is a composite molded article formed by extruding and converging a large number of strips of styrenic resin and other resins that are compatible with the styrene resin, and The resin strips, which are fused to at least one of the layered parts formed of a single resin strip, either styrene resin strips or other resin strips to form a bonding interface, are made of the styrene resin strips or other resin strips. It is characterized by being formed by coexisting two types of resins, a system resin and other compatible resins, in an immiscible state or a miscible state.

Next, regarding the manufacturing method for obtaining the above composite molded product, a styrenic resin and other resins compatible with the styrenic resin are heated and gelled in multiple extruders, and then a large number of small holes are formed. This is a method of extruding a large number of resin strips together from a die having a styrene resin strip, and then collecting and bonding these resin strips to obtain a composite molded product. The resin strip, which is fused to at least one of the layered parts formed by the resin strip to form the bonding interface, is made by melting the above two resins in a mouthpiece and bringing them into an integrated state under pressure. Afterwards, the resin strips in the layered portion are discharged from the cap while controlling the compatibility state using a diversion protrusion provided on the cap, and are fused to the bonding interface. The feature is that one resin is discharged from the mouthpiece and all the strips are collected and integrated.

In the present invention, styrenic resins include general types of styrene resins, impact-resistant styrene resins,
Acrylonitrile-butadiene-styrene copolymer resin (ABS resin), acrylonitrile-styrene copolymer resin (AS resin), methylstyrene resin, styrene-butadiene copolymer resin, styrene-maleic anhydride copolymer resin, etc. alone or in mixtures thereof. is preferable, and other resins that are compatible with the styrene resin are preferably selected from the above styrene resins. A mixture of methacrylate or the like can also be used.

Among these, the most preferred is a combination of polystyrene and polystyrene containing a rubbery polymer such as butadiene or isoprene.

In addition, in the composite molded product of the present invention, both of the two resins may be non-foamed resins, or one of them may be a non-foamed resin and the other may be a foamed resin.
Particularly preferred is a case in which both of the two resins are foamed resins.

Next, embodiments of the present invention will be illustrated below with reference to the drawings.

1 and 2 in the diagram showing the extrusion device shown in FIG.
3 is a plurality of extruders, 3 is an entire base including a resin discharge plate 4 having a large number of small holes 41 to 43, 5 is a cooling pipe, 6 is a guide plate, 7 is a preforming tool, 8 is a molding frame, Reference numeral 9 indicates a water tank, 31 indicates a flow dividing projection on the base 3, 10 indicates a molded product, and 101 to 103 indicate resin strips.

A composite molded product is obtained using the above-mentioned apparatus, in which a styrene resin and other resins compatible with the styrene resin are heated and gelled in a plurality of extruders 1 and 2, and then a large number of small holes 41 are formed. The above two types of resins are extruded as a large number of resin strips 101 to 103 through a mouthpiece 3 equipped with a resin discharge plate 4 having a resin discharge plate 4 having a diameter of 100 to 43. The resin strip 102 for this purpose is one in which the two types of resins are melted in the cap 3 and discharged from the resin discharge plate 4 of the cap 3 in an integrated state under pressure. Reference numerals 101 and 103 discharge a single resin from the above two types of resin from the resin discharge plate 4 of the base 3, and discharge all of the strips 101 to 103.
A composite molded product 10 is obtained in which these are integrated.

Note that the molding temperature conditions differ slightly depending on the type of resin used and whether or not foaming occurs, but in general, extruders are used at 120°C or higher.
Preferably, the molding temperature is 220°C, the temperature of the base is 150 to 180°C, room temperature air is passed through the cooling pipe 5, and room temperature water is passed through the preforming tool 7.

Therefore, in the composite molded article 10, the resin strips constituting the bonding interface between the styrene resin and the other resin are such that the two types of resins described above coexist. This coexistence includes two cases where the two types are not mixed with each other and have a layered structure (Figs. 5 and 6).
(see Fig. 8), or if they are mixed (see Fig. 7).
(see figure). If the two types of resins are not mixed and are formed into a layered structure, the tip of the flow dividing protrusion 31 of the base should be brought into close contact with the resin introduction part of the small hole; This can be adjusted by moving it slightly away from the resin introduction part. For further mixing, use the nozzle 3' as shown in Figure 2.
It is effective to attach a baffle plate 40 or the like to a part of the side small hole 42 to forcibly generate turbulent flow.

Therefore, the composite molded product obtained by the present invention is unique in that the surface portion or intermediate portion of the molded product is partially modified and has a strong fusion bond, and can be used for various purposes. It can exhibit excellent effects.

If the product according to the present invention having the above-mentioned configuration is formed of a foam and the surface portion is modified as shown in FIG. 5, it will be formed as a plate-shaped peripheral frame A as shown in FIG. V-shaped corner bending grooves a are formed at appropriate intervals from the side, and the side of the strip group 101 containing the rubbery polymer at the outermost periphery, which is the outer side of the groove, is utilized as the hinge portion h, Furthermore, a bottom plate insertion groove b is formed, and the bottom plate B is inserted into this groove b.
can be inserted to form a box that can be assembled freely. (Refer to Figure 10) When the composite molded product of the present invention is used for the above-mentioned applications, especially the thin hinge part h which is the outside of the bending groove a, the surface part with a rubbery polymer, etc. This modification softens the rigidity peculiar to polystyrene resins, increases impact resistance, increases hinge strength, and makes it suitable for preventing cracks from occurring when bent. In addition, the outermost surface is not only less susceptible to scratches, but also convenient in terms of preventing the outermost surface from slipping.

For example, by making the used surface part non-foamed or low-foamed and the other parts made highly foamed, it is possible to obtain a lightweight synthetic wood with a hard and scratch-resistant surface and excellent bending strength and compressive strength. This product can be used as building materials, furniture parts, daily necessities parts, etc. As a specific example, as shown in the cross-sectional view of FIG. 11, for a Western-style room flooring member, the layer 101 on the use side A is made of non-expanded impact-resistant polystyrene, and the layer 103 on the other part is made of highly expanded polystyrene ( Density 0.2g/cc) and the above 1 for the 102' layer.
A mixture of materials 01 and 103 (density 0.5g/
cc) is used as an example.

[Brief explanation of the drawing]

The figures illustrate embodiments of the present invention, and FIG. 1 is a sectional view showing an extruded state, FIG. 2 is a sectional view showing a modified example of the die, and FIG. 3 is a sectional view taken along the line - , FIG. 4 is an enlarged sectional view of the small hole portion in FIG. 1 viewed from the extrusion axis direction, FIG. 5 is a sectional view of the composite molded product obtained by the embodiment of FIG. 1, and FIGS. 6 to 8 are Cross-sectional views of modified examples of composite molded products are shown, of which Figure 7 shows a composite molded product obtained using the die shown in Figure 2, and Figure 9 shows a composite molded product obtained by using the composite molded product for the peripheral side frame. FIG. 10 is a perspective view of a box using the peripheral side frame shown in the previous figure, and FIG. 11 is a cross-sectional view when the box is used for a Western-style room flooring member. 1, 2... Extruder, 3... Mouthpiece, 31... Diversion protrusion, 41-43... Small discharge hole, 4... Resin discharge plate, 5... Cooling pipe, 6... Guide plate, 7...
... Preliminary shaping tool, 8 ... Molding frame, 9 ... Water tank, 10
... Composite molded product, 101-103 ... Strip.

Claims (1)

[Scope of Claims] 1. A composite molded product obtained by extruding and converging and bonding a styrene resin strip and a large number of strips made of another resin that is compatible with the styrenic resin. The resin strip is fused to at least one of the layered portions formed of a single resin strip, either the strip or the strip made of another resin, to form a bonding interface. A composite molded article made of a thermoplastic resin, characterized in that it is formed by coexisting two types of soluble resins in an immiscible state or a miscible state. 2 Styrenic resin and other resins that are compatible with the styrenic resin are heated and gelled in multiple extruders, and then extruded together as a large number of resin strips through a die having a large number of small holes. A method for obtaining a composite molded article by focusing and bonding resin strips, the method comprising:
The resin strips that form a joint interface by fusing with at least one of the layered parts formed by a single resin strip, either styrene resin strips or strips made of other resins, are of the two types mentioned above. The above-mentioned resin is melted in the cap and brought into an integrated state under pressure, and then discharged from the cap while controlling the compatibility state using a diversion protrusion provided on the cap, and fused to the joint interface. A method for manufacturing a composite molded product using a thermoplastic resin, characterized in that the resin strips of the layered portion are produced by discharging a single resin from the above two types of resin from a die, and converging and integrating all the strips. .