JP2514543B2 - Method for producing synthetic resin foam sheet having melt coating - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a synthetic resin foam sheet having a molten coating, which is used as a base material for cosmetic puffs, etc., which requires good appearance such as a cone edge of a speaker. .

[0002]

2. Description of the Related Art As a conventional method for producing a synthetic resin foam sheet having a molten coating, a hot-melt synthetic resin foam sheet is pressed with a hot plate or a heat roll to form a molten coating on the surface of the foam sheet. There is known a method of forming a film (JP-A-51-148766). In addition, a metal plate or the like having holes corresponding to a desired depression pattern is placed on the flexible synthetic resin foam sheet, and a hot plate or a heat roll is further pressed onto the metal plate or the like to form the metal plate or the like. There is also known a method in which the foamed material in the pores is melted to have a desired depression pattern (Japanese Patent Publication No. 57-22739).

[0003]

However, in the former method, as shown in FIG. 2 (actual size), the melting surface has a relatively large uneven pattern and wrinkles (black portions are convex portions, white portions are concave portions). Yes, the appearance is not good. Also, in the latter method,
To produce a sheet having a desired depression pattern,
No smooth surface can be formed. Further, in both of these, since the resin foam sheet before heating directly contacts the heating roll, the heating effect is excellent, but the melt adhered to the surface of the heating roll is thermally decomposed and laminated on the surface of the heating roll. Since this adheres to the surface of the molten coating, the quality of the product surface is impaired and continuous production is not possible.

The present invention has been made in view of the above point of view, and provides a method for producing a synthetic resin foam sheet having a molten coating, which is suitable for continuous production and can stably produce a desired smooth surface without staining the surface. The purpose is to provide.

[0005]

The method for producing a synthetic resin foam sheet having a melt coating of the present invention comprises a heat-resistant sheet disposed on at least one surface of a heat-meltable synthetic resin foam sheet, and further comprising: The heat-resistant sheet and the foam sheet are transferred between a pair of pressing bodies equipped with a heating roll or a heating plate so that the foam sheet can be heated from above the heat-resistant sheet, and the heat-resistant sheet and the heat-resistant sheet are pressed under the heat-resistant sheet. And a molten film is formed on the heated surface of the foam sheet by heating the foam sheet.

The above-mentioned foam sheet may be of any type as long as it has a heat-melting property, and is made of, for example, a thermoplastic resin such as polyethylene, polypropylene, polystyrene or polyvinyl chloride, or polyurethane foam (particularly flexible polyurethane foam). ) And the like. The heat-resistant sheet can withstand the temperature used,
Moreover, it is sufficient if it does not stain the heat roll, for example,
Fluororesin sheet, silicone resin sheet, or woven cloth,
A sheet or the like in which a non-woven fabric or paper is surface-treated with a fluororesin or a silicone resin can be used. This thickness is preferably as thin as possible from the viewpoint of heating, while too thin, the strength is not sufficient, and usually 0.1 to 0.
It is 5 mm. This thickness is preferable because it is well balanced in terms of both good heating efficiency and strength.

[0007]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to the following examples. Example 1 Flexible polyurethane foam sheet (polyester type, white, thickness 13 mm, apparent specific gravity 0.032) and heat resistant sheet [glass cloth coated with fluororesin, thickness; 0.08 to 0.3 mm, surface Can be said to be almost a smooth surface, but to be precise, it has fine irregularities (folds when fibers are woven). ] To prepare. Then, as shown in FIG. 1, between the heating roll 3 and the feed roll 4 (gap: 4
mm, compression rate: 31%), the flexible polyurethane foam sheet 1 and the heat resistant sheet 2 are combined, and the heat resistant sheet 2 is arranged on the heating roll 3 side and conveyed.
The roll heating temperature at this time is 280 to 400 ° C. (especially 34
0 ° C), roll speed is 2 to 12 m / min (especially 5
~ 6 m / min).

After heating with a roll, the thickness was 10 mm, and it was found that the surface on the heating side became a pale ocher color and the molten coating film 1b was formed. The surface of the molten coating film was almost smooth. (Smooth surface when touched)
Has become. On the other hand, as a comparative example, when the sheet was heated under the same conditions as above without using the heat-resistant sheet, the surface thereof had relatively large irregularities and wrinkles, as shown in FIG. The black portions in FIG. 2 are convex portions and the white portions are concave portions. Therefore, the product of the present invention is excellent in aesthetic appearance without any uneven surface or wrinkle unlike the conventional example. Further, similarly good smooth surfaces were obtained in any of the above temperature ranges and roll speeds. In addition, since this heat resistant sheet has a surface processed with a fluororesin, it is excellent in peeling from the urethane foam sheet after heating, and since its thickness is thin, it melts the surface in a short time as described above. did it. Further, it is conceivable to subject the roll surface itself to fluorination, but in this case the roll is always heated to a temperature of around 300 ° C., so that it cannot withstand it, and the fluorination surface peels off and cracks occur. However, in the present application, since the heat history is small, the fluorine-treated heat resistant sheet showed sufficient heat resistance. Further, since the pair of rolls are used as the pressing body, the continuous manufacturing method can be performed, which is very convenient.

The present invention is not limited to the specific examples described above, and various modifications may be made within the scope of the present invention according to the purpose and application. That is,
The feed roll can also be a heating roll, and in this case, a molten coating film having an excellent appearance can be formed on both surfaces of the foam sheet. Further, the compressibility during heating can be in the range of 10 to 90%. If it is less than 10%, heat transfer is insufficient due to insufficient pressurization, and a satisfactory molten coating cannot be formed. If it exceeds 70%, compression is excessive and wrinkles and cracks tend to occur on the surface of the molten coating. Absent. The heating temperature, heating time, compressibility, etc. are variously selected according to the type of material used. Further, a heating plate may be used instead of the heating roll. As the heating plate, a plate having a heating coil, a heater, or the like built into the plate, a plate into which a heating medium can be introduced, or the like can be used. In this case, batch operation is usually performed.

[0010]

According to the manufacturing method of the present invention, since it is heated through the heat resistant sheet, the melted / decomposed product does not adhere to the heating surface of the heating roll or the like, and therefore the quality of the product is excellent.
Further, since this heat resistant sheet is less likely to get dirty, this sheet can be used repeatedly, and even if it is repeatedly used, the quality of the product does not deteriorate. Furthermore, since a molten coating film is formed through this heat resistant sheet, as in the past,
There are no relatively large irregularities or wrinkles, so it looks very good. Further, by forming the heat-resistant sheet into a substantially smooth surface or a surface having a predetermined pattern, a coating film having a transferred pattern or the like is formed. By selecting variously, it is possible to form a molten coating film having various patterns and the like.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state of producing a synthetic resin foam sheet having a molten coating in Examples.

FIG. 2 is an explanatory diagram (actual size) showing a surface of a molten coating film of a synthetic resin foam sheet manufactured in the related art.

[Explanation of symbols]

1; synthetic resin foam sheet before heating, 1a; synthetic resin foam sheet after heating, 1b; melt coating, 2; heat resistant sheet, 3; heating roll, 4; feed roll.

Claims (2)

(57) [Claims] 1. A heat-resistant sheet is disposed on at least one surface of a heat-meltable synthetic resin foam sheet, and a heating roll or a heating plate is provided so that the foam sheet can be heated from above the heat-resistant sheet. The heat resistant sheet and the foam sheet are transferred between a pair of pressing bodies, and these are heated through the heat resistant sheet under pressure to form a molten coating on the heated surface of the foam sheet. A method for producing a synthetic resin foam sheet having a melt coating, comprising: 2. The heat resistant sheet is a fluororesin sheet,
A silicon resin sheet, or a sheet obtained by surface-treating woven cloth, non-woven cloth, or paper with fluororesin or silicon resin, and having a thickness of 0.5 mm or less.
A method for producing a synthetic resin foam sheet having the melt coating as described above.