JPH10100298A - Flexible polystyrene resin foam sheet laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polystyrene resin foam sheet laminate having strength and rigidity of necessary minimum limits and flexibility. SOLUTION: In the polystyrene resin foam sheet laminate having polystyrene resin foam sheets each having a thickness of 1 to 4mm as a base, only the one surface has a plurality of cutouts each having a depth reaching 1/2 to 2/3 of a thickness of the base, and the other surface having no cutouts is laminated with a non-foam resin layer having a thickness of 20 to 200μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polystyrene resin foam sheet laminate in which a non-foam resin layer is laminated on at least one surface of a polystyrene resin foam sheet.
The present invention relates to a polystyrene-based resin foam sheet laminate that does not generate winding habit or curl and has excellent flexibility at the time of bending.

[0002]

2. Description of the Related Art A polystyrene resin foam sheet has a heat insulating property,
Molded into containers such as trays and bowls from the viewpoints of rigidity, thermoformability, lightness, hygiene and economy, and used in various fields including containers for instant cooked foods and various other containers. ing. In particular, since a polystyrene resin is a glassy substance at room temperature, its foam sheet has extremely high rigidity, and when it is made into a container, compared to other materials (eg, polyethylene resin, polypropylene resin, etc.) It has the characteristic of giving a firm feeling and giving a sense of security, and is used in large quantities in the plastic molding field. However, due to such properties, the polystyrene resin foam sheet has a drawback that it is inferior in flexibility.

[0003] As a method for producing such a polystyrene resin foam sheet, an extrusion foam molding method has conventionally been widely used because the production process is simple and the quality is stable. In this extrusion foam molding method,
By discharging the polystyrene-based resin composition melt-kneaded with a foaming agent and the like in an extruder into the atmosphere from an annular die orifice, a tubular polystyrene-based resin foam is formed, and then the tubular polystyrene-based resin is formed. The inner surface of the foam is cooled by contacting the cooled drum. Next, a tubular polystyrene-based resin foam is cut open from both sides, divided vertically and wound up to obtain a polystyrene-based resin foam sheet.

However, the polystyrene-based resin foam sheet obtained here has a higher rigidity at room temperature than other general-purpose resins (eg, polyethylene and polypropylene) due to the properties derived from the polystyrene-based resin. Since the curd is easily formed when the contact is solidified and the curl is formed when the film is wound, curling about the flow direction and / or curl about the direction perpendicular to the flow direction occurs.

[0005] In addition, since these once-added habits cannot be easily corrected because of their high rigidity, the polystyrene resin foam sheet has a disadvantage that the flatness of the sheet itself is poor. Further, if this is forcibly corrected or rolled into a small diameter, it is easily broken or broken, so that there is a drawback that the range of application is limited.

[0006]

For these reasons, polystyrene-based resin foam sheets are generally formed exclusively by thermoforming into containers such as trays and bowls, and have the drawback that their application range is narrow. Was. In particular, a flat cushioning material for architectural curing sheets and cushioning paper bags, or a cushioning material for relatively fragile materials such as plate glass or a material whose surface is easily damaged, or a cushioning material for paper and other rolled-up materials. Almost no use can be made for applications requiring properties and flexibility, and polyolefin-based foam sheets and polyurethane-based foam sheets, which have high flexibility, are mainly used for these applications.

Accordingly, a first object of the present invention is to provide a polystyrene resin foam sheet laminate which is excellent in flexibility and good in flatness and hard to be brittlely broken when bent. A second object of the present invention is to eliminate the drawbacks of the polystyrene resin foam sheet and expand the range of application.

[0008]

SUMMARY OF THE INVENTION The above objects of the present invention are directed to a polystyrene resin foam sheet laminate having a base of a polystyrene resin foam sheet having a thickness of 1 mm to 4 mm. , The depth is 1 / th of the thickness of the substrate
A flexible polystyrene resin foam characterized by having a plurality of cuts reaching 2/3 and a non-foamed resin layer having a thickness of 20 μm to 200 μm laminated on a surface having no cuts. Achieved by sheet laminate.

The polystyrene resin is not particularly limited. For example, general-purpose polystyrene resin, high impact polystyrene resin, styrene-acrylonitrile copolymer resin, styrene-methyl methacrylate copolymer resin, styrene-acrylic acid copolymer It can be appropriately selected from polymer resins, styrene-maleic anhydride copolymer resins, and mixtures thereof, and used.

An inorganic substance such as talc or calcium carbonate as a foam nucleating agent, a plasticizer and a stabilizer can be added to these polystyrene resins according to desired physical properties. As the foaming agent, a physical foaming agent or a chemical foaming agent known as a foaming agent for a polystyrene-based resin foam can be appropriately selected and used.

Examples of the physical foaming agent include hydrocarbon compounds such as propane, butane, hexane and heptane, Freon-11, Freon-12, Freon-113, Freon-114 (Freon is a trade name of DuPont), methyl chloride And halogenated hydrocarbon compounds such as methylene chloride. Examples of the chemical foaming agent include an organic thermal decomposition type foaming agent such as azodicarbonamide, and a combination of bicarbonate and an organic acid such as citric acid.

[0012] As the polystyrene resin foam sheet that can be used in the present invention, a sheet obtained by a commonly used extrusion foam molding method can be used. In the extrusion foam molding method, the above-mentioned resin composition (plasticizer and stabilizer as necessary) and an inorganic substance and a foaming agent as a foam nucleating agent (cell regulator) are mixed in an extruder heated to a predetermined temperature. After melting and kneading, and forming a polystyrene resin foam into a tube by discharging into the atmosphere from an annular die orifice, the inner surface of the tube polystyrene resin foam is brought into contact with a cooled drum and cooled. I do.

Next, a tubular polystyrene resin foam is cut open from both sides, divided vertically and wound up to obtain a polystyrene resin foam sheet.
The physical properties of the polystyrene resin foam sheet are 1 m in thickness.
By appropriately adjusting extrusion conditions (manufacturing conditions such as temperature, extrusion amount, take-up speed, blow-up ratio) so that the expansion ratio is in the range of 5 to 15 times at m to 4 mm, and / or It can be adjusted by the amount of the agent or foam nucleating agent added.

The obtained polystyrene-based resin foam sheet can be provided with the desired flexibility and flatness by itself by making a cut in at least one surface while leaving a part in the thickness direction. However, since the bending strength of the foamed sheet itself is weak and the thickness portion left by the cut becomes very thin, there is a problem that the bending strength is practically improved.

On the other hand, in the case of the present invention, the non-cut surface of the expanded polystyrene substrate having a plurality of cuts reaching 1/2 to 2/3 of the thickness is provided only on one surface. Since the foamed resin layer is laminated, not only the bending property and the flat property but also the bending strength are sufficient.
In the present invention, a non-foamed resin layer is laminated on both sides of a polystyrene-based resin foamed sheet substrate, and from one side, the thickness of the polystyrene-based resin foamed sheet substrate is ２〜 to ／ of the thickness of the substrate.
May be provided. According to the present invention, a polystyrene-based resin foam sheet laminate can be provided with flexibility having bending strength, so that it can be used in applications requiring flatness, which has not been conventionally used, or is wound into a relatively small diameter. The range of application will be expanded for applications.

The polystyrene resin foam sheet used in the present invention has a thickness of 1 mm to 4 mm and an expansion ratio of 5 times to 5 times.
Although it is 15 times, this is in consideration of the heat insulating property, cushioning property, strength, application, and the like, which are characteristics of the polystyrene resin foam sheet. The non-foamed resin layer used in the present invention needs to have a thickness of 20 μm to 200 μm in order to maintain sufficient bending strength and from the viewpoint of economy.

The lamination of a foamed polystyrene resin sheet and a non-foamed resin layer of a synthetic resin is performed by a so-called thermal lamination method in which pressure is applied between heat rolls which are generally used, and a synthetic lamination with a foamed polystyrene resin sheet. A resin non-foamed resin layer is bonded and laminated via a melt-extruded thermoplastic resin layer, a so-called sand lamination method, or a non-foamed resin layer is directly melt-extruded and laminated on a polystyrene resin foam sheet substrate. Any of the extrusion lamination methods may be adopted.

In the present invention, the cut into the foamed polystyrene resin sheet is performed by first providing a non-foamable resin layer on at least one surface of the foamed polystyrene resin sheet base to form a laminate, and then using a roll having a blade. A so-called die-roll method, a cutting machine using a plate-like material having a blade, a slitter method using a round blade or a razor blade, or the like, is used to make a cut reaching 1/2 to 2/3 of the substrate. This is done by: This notch is
From the viewpoint of imparting flexibility, it is preferable to set the interval to 20 mm or less, but when considering the strength, it is 3 mm to 20 m.
m is preferable.

The reason why the depth of cut is set in the above range is to suppress a decrease in bending strength and overall strength as much as possible and to provide sufficient flexibility. If the cutting depth is deep, the strength is remarkably reduced, and if it is shallow, sufficient flexibility cannot be obtained. In addition, when the non-foamable resin layer is provided only on one surface of the polystyrene-based resin foam sheet substrate, the cut is naturally provided from the side where the non-foamable resin layer is not laminated. Further, the cut pattern to be formed on the surface of the polystyrene resin foam sheet laminate of the present invention is arbitrary.

When using the thermal lamination method or the sand lamination method, the synthetic resin film used as the non-foamed resin layer is preferably a polyethylene resin film, a polypropylene resin film, a high-impact polystyrene resin film, a polyethylene terephthalate resin film, or the like. This is because, from the strength characteristics of these films, it is possible to minimize the strength reduction due to the provision of cuts in the polystyrene resin foam sheet,
Because it is a versatile film, it is easily available and inexpensive, and can prevent a rise in manufacturing cost.

As the thermoplastic resin layer used in the sand lamination method or the non-foamable resin layer used in the extrusion lamination method, polyethylene resin,
Polypropylene resin, high impact polystyrene resin, polystyrene resin and the like are preferable. This is because these resins have a property of sufficiently securing the adhesiveness to the base material using a general-purpose extrusion equipment, and the foamed sheet laminate can be easily manufactured.

The flexibility referred to in the present invention is to evaluate the degree by using "deflection" as an index. That is, a sample is made into a rectangular body having a size of 2 cm × 10 cm, a load of 0.1 kg is applied to the tip, and the deflection distance of the tip when the beam length of 5 cm from the tip is a fulcrum is measured and evaluated. The higher the rigidity (the lower the flexibility), the smaller the deflection distance, and the greater the flexibility, the longer the deflection distance. The flatness referred to in the present invention is an evaluation of the degree to which deformation such as curling is eliminated when a 50 cm square sheet sample is allowed to stand on a flat place.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The foamed polystyrene resin sheet of the present invention has a thickness of at least one surface of a foamed polystyrene resin sheet having a thickness of 1 mm to 4 mm, which is formed by a heat lamination method, a sand lamination method, or a melt extrusion method. It can be manufactured by laminating a non-foamed resin layer having a thickness of 20 μm to 200 μm, and then making a plurality of cuts in the polystyrene-based resin foamed sheet to reach ２〜 to の of the thickness.

[0024]

The polystyrene resin foam sheet laminate of the present invention can provide flexibility and remove stress from the surface while maintaining the minimum strength and rigidity required for the polystyrene resin foam sheet. Therefore, the appearance defect due to curl or the like is eliminated, and the flatness is excellent, so that the application range to fields that cannot be used normally is expected to be expanded. This increases the value of use as a polystyrene-based resin foam sheet laminate, so that the present invention reduces waste and can also contribute to environmental protection.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Embodiment 1 FIG. On one surface of a foamed sheet made of a polystyrene resin having a thickness of 2.2 mm and an expansion ratio of 9.8, a thickness of 30
Using a roll heated to a surface temperature of about 150 ° C., a film made of a μm polystyrene resin was bonded and laminated (thermal lamination method) by thermocompression bonding to produce a composite sheet.

Next, the surface of the composite sheet on the foam sheet side (the side on which the polystyrene resin layer is not laminated) is
At a distance of 0 mm, cuts having a depth of 1.4 mm were made in a lattice pattern to obtain a polystyrene resin foam sheet laminate of the present invention. The polystyrene-based resin foam sheet laminate before the cut was inferior in appearance due to the curl left at the time of winding, but the cut sheet was curled and had a good flatness. Met. Also,
The "deflection" as an index of the flexibility is 30 mm, and it is clear that the flexibility is improved as compared with 3 mm of the conventional sheet before cutting.

Embodiment 2 FIG. A polystyrene resin foam sheet laminate of the present invention was obtained in exactly the same manner as in Example 1 except that the cut interval was 5 mm. The obtained polystyrene-based resin foam sheet laminate had good flatness as in the case of Example 1, and the "deflection" was 50 mm, and the flexibility was further improved as compared with the case of Example 1. Embodiment 3 FIG. A composite sheet was manufactured in exactly the same manner as in Example 1, except that a foamed sheet made of a polystyrene resin having a thickness of 3.8 mm and an expansion ratio of 11.8 was used. Next, 2.4 mm deep cuts were made in a grid at 10 mm intervals on the foam sheet side surface of the composite sheet to obtain a polystyrene resin foam sheet laminate of the present invention. The obtained polystyrene-based resin foam sheet laminate is excellent in flatness as in Example 1, and the “deflection” is 22 mm.
And flexibility had been improved.

Embodiment 4 FIG. 1.4mm thickness, foaming ratio 1
A composite sheet was manufactured in the same manner as in Example 1, except that a foam sheet made of a 0.0 times polystyrene resin was used.
Next, 10 m was added to the surface of the composite sheet on the foam sheet side.
At a distance of m, cut in a lattice shape with a depth of 0.7 mm,
A polystyrene resin foam sheet laminate of the present invention was obtained.
The obtained polystyrene-based resin foam sheet laminate was excellent in flatness as in Example 1, but had extremely large "deflection" and was not able to be measured.

Embodiment 5 FIG. Thickness 2.2 mm, expansion ratio 9.
A film made of a polystyrene resin having a thickness of 30 μm is bonded and laminated (a sand lamination method) on one surface of a foamed sheet made of an eight-fold polystyrene resin via a melt-extruded high-impact polystyrene resin.
A composite sheet having a layer structure was manufactured. At this time, the layer thickness of the high impact polystyrene resin was 100 μm. Then, a cut was made in the surface of the composite sheet on the foam sheet side in the same manner as in Example 1 to obtain a polystyrene resin foam sheet laminate. The flatness of the obtained polystyrene-based resin foam sheet laminate is good, and the “deflection” is also 23 mm.
And the flexibility was improved.

Embodiment 6 FIG. Thickness 2.2 mm, expansion ratio 9.
A high-impact polystyrene resin was melt-extruded to a thickness of 150 μm and laminated (extruded lamination method) on one surface of a foam sheet made of an 8-fold polystyrene resin to produce a composite sheet. Next, a cut was made in the surface on the foam sheet side in the same manner as in Example 1 to obtain a polystyrene resin foam sheet laminate. The flatness of the obtained polystyrene resin foam sheet laminate is good,
The "deflection" was extremely flexible at 30 mm.

Comparative Example 1 A laminated sheet was manufactured in exactly the same manner as in Example 1 except that no cut was made. The resulting polystyrene-based resin foam sheet laminate is inferior in appearance with curls attached at the time of winding remaining, and forcibly tried to correct the curl, but could not eliminate it at all,
The flatness was poor. In addition, "deflection" is 3
mm, the rigidity was extremely high, and almost no flexibility was obtained.

Comparative Example 2 A laminated sheet was obtained in exactly the same manner as in Example 5 except that no cut was made. The resulting polystyrene-based resin foam sheet laminate had poor appearance due to the curl remaining during winding. Further, the curl was forcibly corrected, but could not be completely eliminated, and the flatness was poor. In addition, the deflection is 1
mm, the rigidity was extremely high, and almost no flexibility was obtained.

Comparative Example 3 Thickness 2.2 used in Example 1
A cut having a depth of 1.1 mm was cut in a lattice shape at intervals of 10 mm on one surface of a foamed sheet made of a polystyrene resin having an expansion ratio of 9.8 mm to obtain a cut polystyrene resin foam sheet alone. The obtained polystyrene-based resin foam sheet alone had poor appearance due to curl remaining at the time of winding before the cut was made, but the one with the predetermined cut was curled and flat. The sheet was rich in flexibility and was sufficiently imparted with flexibility. However, at the time of evaluation of the "deflection" as an index, the strength was reduced to such an extent that the sheet was broken, and was unsuitable for practical use.

Comparative Example 4 Using the composite sheet having a two-layer structure obtained in the same manner as in Example 1, a cut was made in the same manner as in Example 1, and the depth was set to 1.8 mm. The obtained laminated sheet was excellent in flatness and sufficient in flexibility, however, similarly to the case of Comparative Example 3, it caused a strength reduction such that the sheet was broken at the time of “deflection” evaluation, and was unsuitable for practical use. It was something.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a polystyrene resin foam sheet laminate of the present invention.

FIG. 2 is a schematic cross-sectional view showing each example of a polystyrene resin foam sheet laminate of the present invention.

FIG. 3 is a schematic cross-sectional view showing each example of the polystyrene resin foam sheet laminate of the present invention.

FIG. 4 is a schematic cross-sectional view showing each example of a polystyrene resin foam sheet laminate of the present invention.

FIG. 5 is a schematic view of a cutting pattern to be inserted into the polystyrene resin foam sheet laminate of the present invention.

FIG. 6 is a schematic view of a cutting pattern to be inserted into the polystyrene resin foam sheet laminate of the present invention.

FIG. 7 is a schematic view of a cutting pattern to be inserted into the polystyrene resin foam sheet laminate of the present invention.

FIG. 8 is a schematic view of a cut pattern to be inserted into the polystyrene resin foam sheet laminate of the present invention.

FIG. 9 is a schematic view of a cutting pattern to be inserted into the polystyrene resin foam sheet laminate of the present invention.

[Explanation of symbols]

 Reference Signs List 1 foamed polystyrene resin sheet 2 synthetic resin film 3 thermoplastic resin layer 4 cut

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Suzuki 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Japan Paper Manufacturing Co., Ltd.

Claims (8)

[Claims] 1. A foamed polystyrene-based resin sheet comprising a foamed polystyrene-based resin sheet having a thickness of 1 mm to 4 mm as a substrate, wherein only one of the surfaces has a depth of 1/2 to 2 times the thickness of the substrate. / 3 and a thickness of 20 μm to 200 μm on the non-cut side.
A foamed polystyrene resin foam sheet having flexibility, wherein a non-foamed resin layer of μm is laminated. 2. The non-foamed resin layer has a thickness of 20 μm to 70 μm.
m, a film selected from the group consisting of a polyethylene resin film, a polypropylene resin film, a high-impact polystyrene resin film and a polyethylene terephthalate resin film, which are laminated by thermocompression bonding on a polystyrene resin foam sheet substrate. A flexible polystyrene resin foam sheet laminate according to claim 1. 3. The non-foamed resin layer has a thickness of 20 μm to 70 μm.
m, a film selected from the group consisting of a polyethylene resin film, a polypropylene resin film, a high-impact polystyrene resin film and a polyethylene terephthalate resin film, and a melt-extruded thermoplastic resin layer through a polystyrene resin foam sheet substrate. The flexible polystyrene-based resin foam sheet laminate according to claim 1, wherein the laminate is provided by laminating and adhering. 4. The non-foamed resin layer is formed by laminating a resin selected from the group consisting of a polyethylene resin, a polypropylene resin, a high-impact polystyrene resin and a polystyrene resin onto a polystyrene resin foam sheet base by melt extrusion and has a thickness of 50 μm. The flexible polystyrene resin foam sheet laminate according to claim 1, which is a layer having a thickness of from 200 to 200 µm. 5. The flexibility according to claim 1, wherein the cut surface of the foamed polystyrene resin sheet is a cut surface after a non-foamed resin layer is provided in advance. Polystyrene-based resin foam sheet laminate. 6. The flexible polystyrene resin foam sheet laminate according to claim 1, wherein a plurality of cuts are provided at intervals of 3 mm to 20 mm. 7. The flexible polystyrene resin foam sheet laminate according to claim 6, wherein the cuts are provided in a grid pattern. 8. The flexible polystyrene resin foam sheet laminate according to claim 1, wherein the expansion ratio of the polystyrene resin foam sheet base is 5 to 15 times.