JP2002127318A - Molded laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out good molding for a molded laminate of three layer structure comprising a skin, a cushion layer and a core material. SOLUTION: The molded laminate 10 is made by laminating the skin 11 and the core material 13 with the cushion layer 12 between them to form a sheet, which is then molded by vacuum forming with the skin 11 facing a molding surface 21 of a vacuum mold 20. The core material 13 contains 30-40 wt.% of polypropylene and 55-65 wt.% of polystyrene or an acrylonitrile butadiene styrene resin.

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 used as, for example, a vehicle interior (instrument panel, door trim, pillar, console box, roof trim, etc.).

[0002]

2. Description of the Related Art A laminated molded product of this type has a three-layer structure including a skin, a cushion layer, and a core. After the skin and the core material are laminated in a sheet shape with the cushion layer interposed therebetween, the laminated molded product is heated and softened so that the stretching resistance (for example, the force required to extend 10%) becomes an appropriate magnitude. Then, vacuum molding is performed so that the skin faces the molding surface of the vacuum mold. The core of this molded product is 100% polypropylene
It is made of

[0003]

As shown by the thin line in FIG. 2, in the above-mentioned conventional laminated molded product, the optimum temperature range R1 with respect to the optimum stretching resistance range R of the core material during vacuum forming is narrow. There was a problem that it was difficult. That is, the temperature of the core material decreases by about 10 ° C. from the start of vacuum suction to the end of molding. In contrast, polypropylene 10
The optimum temperature range R1 of the 0% core material is about 149 ° C. to 155 ° C.
° C and only about 6 ° C in width. Therefore, even if the core material is set at the upper limit of the optimum temperature range R1 (about 155 ° C.) and the vacuum suction is started, it falls below the lower limit of the range R1 (about 149 ° C.) on the way, and the elongation resistance becomes too large ( (It becomes too hard) and cannot be deformed until it is completely adhered to the molding surface. On the other hand, when the core material is heated to a temperature higher than the upper limit (for example, about 160 ° C.) and the vacuum suction is started so that the core material is within the range R1 at the end of the molding, the elongation resistance is lowered while cooling to the range R1. It may be too small and breakage may occur.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a skin, a cushion layer, and a core material, and the skin and the core material are sandwiched between the cushion layers. In a laminated molded article vacuum-formed such that the skin faces the molding surface of the vacuum mold after being laminated in a shape, the core material is 30 to 40% by weight of polypropylene, polystyrene or acrylonitrile-butadiene-styrene. (Hereinafter referred to as “ABS”) in an amount of 55 to 65% by weight.
It is characterized by containing. Here, the core material is
Further, the above polypropylene and the above polystyrene or AB
It is desirable to contain 3 to 5% by weight of a compatibilizer that assists in mixing with S.

[0005]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1C, the laminated molded product 10 includes a skin 11, a cushion layer 12 laminated on the skin 11, and a core material 13 laminated on the cushion layer 12. The skin 11 is formed of, for example, a polyolefin-based thermoplastic elastomer. Its thickness is, for example, 0.4 mm to 1.6 mm. The cushion layer 12 is formed of, for example, a polypropylene foam having an expansion ratio of 10 to 40 times. Its thickness is, for example, 1 mm to 4 mm.

The core 13 is a feature of the present invention, and is formed of a resin obtained by mixing polypropylene and polystyrene to a thickness of, for example, 0.4 mm to 3.0 mm. 30 to 40% by weight of polypropylene and 55 to 65% of polystyrene are contained with respect to the entire core material 13.
% By weight.

Further, a compatibilizer made of, for example, a polyolefin-based thermoplastic elastomer is added to the core material 13 in an amount of 3 to 5 times.
% By weight (preferably 5% by weight). This compatibilizer is for facilitating the mixing of polypropylene and polystyrene.

The operation will be described. As shown by the thick line in FIG. 2, when polystyrene is mixed with polypropylene, the optimum temperature range R2 with respect to the optimum stretching resistance range R shifts to a higher temperature side than the case of 100% polypropylene (conventional core material). However, it has been found through experiments that the gradient of the increase in the stretching resistance with respect to the temperature decrease within the range R becomes gentle (that is, the optimum temperature range R2 becomes wide). Moreover, it was found that when the polystyrene content was 55% by weight, the width of the optimum temperature range R2 certainly exceeded 10 ° C. Further, as the polystyrene content is more than 55% by weight, the width becomes larger.
When it is more than 5% by weight, it has been found that when it is used for the core material 13, it is difficult to adhere to the cushion layer 12.

From the above experimental results, it was found that the composition of the core material 13 was 30 to 40% by weight of polypropylene and 55 to 65% of polystyrene.
By setting the weight percentage, the laminated molded article 10 can be favorably molded.

That is, as shown in FIG. 1 (a), when manufacturing a laminated molded product 10, first, a skin 11 and a core material 13 are laminated with a cushion layer 12 therebetween by extrusion lamination or the like. The sheet 14 to be formed is formed. At this time, since the polystyrene content of the core 13 is 65% by weight or less, the core 13 and the cushion layer 12 can be securely bonded.

Thereafter, the sheet 14 is heated by a heater (not shown).
To soften by heating. At this time, the temperature of the core material 13 is set near the upper limit in the optimum temperature range R2.

Subsequently, the sheet 14 is set on the vacuum mold 20 such that the skin 11 faces the molding surface 21 of the vacuum mold 20.

Then, as shown in FIG. 1B, a vacuum is sucked between the sheet 14 and the vacuum mold 20. At the start of the suction, since the stretching resistance of the core 13 is sufficiently smaller (softer) than the upper limit of the optimum range R, the portion 14a of the sheet 14 covering the recess 21b of the molding surface 21 is moved toward the inner surface of the recess 21b. It can be reliably deformed. Moreover,
Since the elongation resistance of the core material 13 is within the optimum range R (has an appropriate hardness), the annular shape that faces the flat portion 21a of the molding surface 21 of the sheet 14 and surrounds the covering portion 14a Part 14b of the recess 21
b can be shifted toward the inner surface. Thereby, it is possible to prevent the portion of the sheet 14 that should be attached to the inner surface of the concave portion 21b (the portion where the covering portion 14a and the annular portion 14b are shifted into the concave portion 21b) from becoming excessively thin, and thus it is possible to prevent breakage. Can be prevented.

The core 13 cools down with the passage of time, and at the end of the vacuum suction, the temperature has dropped by about 10 ° C. from the time when it started. However, since the width of the optimum temperature range R2 is 10 ° C. or more, it still falls within the optimum stretching resistance range R. Therefore, as shown in FIG. 1C, it is possible to maintain appropriate softness until the suction is completed, and it is possible to reliably deform the sheet 14 until it fits snugly on the inner surface of the recess 21b. Thereby, the laminated molded product 10 in a favorable molded state can be obtained.

It should be noted that ABS may be used as the composition of the core material 13 instead of polystyrene. ABS content is
55% by weight to 65% by weight same as the above polystyrene. The experimental result of the relationship between the drawing resistance and the temperature in that case was almost the same as FIG.

[0016]

As described above, according to the present invention,
The molding of the laminated molded article can be favorably performed.

[Brief description of the drawings]

1A and 1B show a forming process of a laminated molded product according to an embodiment of the present invention, in which FIG. 1A is a cross-sectional view in a state where a sheet to be a laminated molded product is set in a vacuum mold, and FIG. Is a sectional view at the beginning of vacuum suction, and (c) is a sectional view at the end of vacuum forming.

FIG. 2 is a graph showing the experimental results of the relationship between temperature and stretching resistance for a 100% polypropylene resin and a mixed resin of polypropylene and polystyrene.

[Explanation of symbols]

 Reference Signs List 10 laminated molded product 11 skin 12 cushion layer 13 core material 20 vacuum mold 21 molding surface

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 55:02 B29K 55:02 105: 16 105: 16 B29L 9:00 B29L 9:00 F term (reference) 4F100 AK07C AK12C AK74C AL05C AR00A AR00B BA03 BA07 BA10A BA10C CA30C EH90 GB31 HB00A JK08 JK11B JK13 JL01 YY00C 4F208 AA11 AA13 AA25 AB10 AG01 AG03 AH26 MA01 MB01 MC01 MG04

Claims (2)

[Claims] 1. A skin comprising a skin, a cushion layer, and a core material, and after the skin and the core material are laminated in a sheet shape with the cushion layer interposed therebetween, the skin is faced to a vacuum mold forming surface. In the vacuum-molded laminated molded product, the core material is 30 to 40% by weight of polypropylene and 55 to 6% of polystyrene or acrylonitrile-butadiene-styrene.
A laminated molded product characterized by containing 5% by weight. 2. The method according to claim 1, wherein the core material comprises the polypropylene and the polystyrene or acrylonitrile-butadiene.
The laminated molded article according to claim 1, further comprising 3 to 5% by weight of a compatibilizer that assists in mixing with styrene.