JPH05154951A - Production of laminated sheet - Google Patents

Abstract

PURPOSE:To make warpage hard to generate at the time of molding under heating in a laminated sheet wherein non-foamed resin sheets are laminated and bonded to both surfaces of a foamed thermoplastic resin sheet. CONSTITUTION:A laminated sheet wherein non-foamed resin sheet is laminated and bonded to the single surface or both surfaces of a foamed thermoplastic resin sheet is heat-treated to reduce the volatile component remaining in the foamed thermoplastic resin sheet to 1.3wt.% or less and, thereafter, the non- foamed resin sheet is laminated and bonded to the exposed surface part of the foamed thermoplastic resin sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method for obtaining a laminate having good thermoformability.

[0002]

2. Description of the Related Art Laminates having thermoplastic resin foam as an intermediate layer and non-foamed resin layers on both sides are used in various applications including containers.

[0003]

In the above conventional laminated plate, the intermediate layer is refoamed by heating during thermoforming due to the volatile components such as the foaming agent and water remaining in the thermoplastic resin foam of the intermediate layer. However, the laminated plate is liable to sag or warp, which poses a problem in applications where the laminated plate is required to have smoothness accuracy. For example, a winding frame for winding a storage tape for an IC chip as shown in FIG. 1 and FIG. 2 is constructed by sandwiching a winding barrel portion 1 with a pair of flange portions 2 and 3, and the flange 2.3 thereof. The part is formed by the laminated plate as described above.

Therefore, if the flange portion bends during thermoforming, the spacing between the flange portions may widen or narrow, and the guide effect for winding the storage tape may disappear, or the storage tape may have a flange portion. There is a problem that the storage tape cannot be wound up in an extreme case because the IC chip is rubbed against each other to remove the IC chip. Therefore, it is an object of the present invention to provide a manufacturing method for obtaining a laminated plate which is less likely to be affected by heating (such as warpage) during thermoforming.

[0005]

In order to achieve the above object, a method for producing a laminated board, which is a feature of the present invention, is a thermoplastic foamed resin sheet or a thermoplastic foamed sheet in which a non-foamed resin sheet is laminated and adhered on one side. The resin sheet is heat treated to reduce the volatile content remaining in the thermoplastic foamed resin sheet to 1.3.
After the content of the non-foamed resin sheet is adjusted to be less than or equal to wt%, the non-foamed resin sheet is laminated and adhered to the exposed surface portion of the thermoplastic foamed resin sheet.

However, the thermoplastic foamed resin sheet used in the production method of the present invention includes butane as a foaming agent,
A sheet of expanded polystyrene, expanded polypropylene, expanded polyethylene, etc. extruded using an extruder by mixing 5 to 8% by weight of volatile components such as freon and pentane, the expansion ratio of which is 5 to 50 times, meat Thickness is 0.5-6 mm
Is.

The non-foamed resin sheet is a sheet of ordinary polystyrene, high-impact polystyrene, polypropylene, polyethylene or the like and has a wall thickness of 0.0
It is 2 to 0.4 mm. An adhesive such as an ethylene-vinyl acetate copolymer or an ethylene-vinyl acetate copolymer reacted with an acid anhydride may be used for laminating and bonding the both sheets, and the non-foamed resin may be heated. The sheets may be melted and adhered.

Furthermore, the volatile matter remaining in the thermoplastic foamed resin sheet is adjusted to 1.3% by weight, preferably 1% by weight or less.
When the thermoplastic foamed resin sheet is laminated with the non-foamed resin sheet (2) which is aged in a thermostatic chamber at about 80 ° C,
The sheet is passed through several heating rollers of about 0 to 80 ° C so that the front and back surfaces of the sheet are in close contact with the heating roller. (3) Heat when extruding and laminating a non-foaming resin sheet on one side of a thermoplastic foaming resin sheet (200 to 280 ° C.) may be used, but the adjustment according to (1) is preferable.

The volatile matter in the thermoplastic foamed resin sheet after the above treatment is precisely weighed (Xg) in about 2 g of the sample after the treatment.
Then, it is heated and dried in a hot air circulation dryer at 120 ° C. for 4 hours or 140 ° C. for 1.5 hours, then taken out and left for 5 minutes. Subsequently, the sample is left to stand in a desiccator for 30 minutes, then precisely weighed (xg), and calculated by (X−x) ÷ X × 100.

[0010]

【Example】

Example 1 A foamed polystyrene sheet having a wall thickness of 2.2 mm and a foaming ratio of 10.5 times (ZE-2200A manufactured by Mitsubishi Petrochemical Verditsie Co., Ltd.) was aged in a thermostatic chamber at 60 ° C. for 7 days to obtain After adjusting the volatile content remaining in the expanded polystyrene sheet to 1.0% by weight, a high-impact polystyrene sheet (MI-5150 manufactured by Denka Polymer Co., Ltd.) was used as an intermediate layer on both sides of the expanded polystyrene sheet to a wall thickness of 0.15 mm. The laminate was obtained by extrusion lamination.

Examples 2 and 3: The same procedure as in Example 1 was carried out except that the volatile content remaining in the expanded polystyrene sheet was changed to 0.7% by weight and 0.3% by weight, respectively. Example 4:
High impact polystyrene sheet with a wall thickness of 0.20 mm
The same procedure as in Example 1 was carried out except that the volatile matter remaining in the expanded polystyrene sheet was adjusted to 0.7% by weight by extrusion extrusion. Example 5: Instead of a high-impact polystyrene sheet, a polypropylene sheet having a thickness of 0.15 mm was adhered with an adhesive layer having a thickness of 0.03 mm, and the volatile matter remaining in the expanded polystyrene sheet was 0. The same procedure as in Example 1 was performed except that the amount was changed to 0.7% by weight.

Comparative Examples 1 and 2 were carried out in the same manner as in Example 1 except that the volatile content remaining in the expanded polystyrene sheet was changed to 1.5% by weight and 3.0% by weight, respectively.

Each of these laminated plates has a diameter of 600 mm.
The plate was punched into a disk shape, and on the 7th day after the molding, the warp in the longitudinal direction and the warp in the lateral direction of the portion separated by 20 mm from the peripheral edge of the disk were measured at three points. Further, using a thermoforming machine, each laminated plate is heated to 100 ° C. and evacuated from both sides to manufacture the flange portions 2 and 3 of the reel 1 shown in FIGS. 1 and 2, and the thermoformability thereof is obtained. Was evaluated.

In this evaluation, there are three levels: ◯: no problem, Δ: a small amount of dripping occurs on the laminated plate during heating, and ×: dripping occurs on the laminated plate during heating. The results are shown in the table below. Shown together with the state where warpage occurs.

[0015]

[Table 1]

[0016]

As described above, the present invention is capable of producing a laminated plate which has no problem in terms of thermoformability and is less likely to warp when thermoformed. The benefits to the field of the thermoforming industry are enormous.

[Brief description of drawings]

FIG. 1 is a perspective view showing a winding frame of a storage tape for an IC chip using a laminated board of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area B29L 9:00 4F

Claims (1)

[Claims] 1. A thermoplastic foamed resin sheet or a thermoplastic foamed resin sheet in which a non-foamed resin sheet is laminated and adhered on one side is heat treated to reduce the volatile content remaining in the thermoplastic foamed resin sheet to 1.3. A method for producing a laminated board, which comprises laminating and bonding a non-foamed resin sheet to an exposed surface portion of a thermoplastic foamed resin sheet after the content of the non-foamed resin sheet is reduced to not more than 10% by weight.