JP2971509B2 - Composite film with support film temporarily attached - Google Patents

Description

The present invention relates to a composite film of a polyvinyl chloride resin (hereinafter, referred to as a PVC film). More specifically, the present invention relates to a composite film for maintaining dimensional stability of a PVC film used for various applications when the film is printed, coated or heat-treated.

[Conventional technology and problems] PVC film has excellent performance characteristics, such as easy processability, flexibility, coloring, printability, adhesion to other substrates, flame retardancy or relatively low Because of its price and the like, it is used in the largest amount among general-purpose resins. However, due to its flexibility and low heat resistance, the dimensional stability is remarkably inferior when exposed to high temperatures, under tension, or when a solvent penetrates during the various processes in which PVC films are processed. However, the processing conditions are narrow and the processing method is limited.

In order to solve this problem, conventionally, this PVC film is heat-resistant, other materials with good solvent resistance, such as films of polyester resin and fluorine resin, paper, fiber materials such as nonwoven fabric, iron, aluminum, etc. A composite film composed of a metal foil or the like is used.

However, these conventional composite films are made of PVC.
The flexibility, adhesiveness, and processability inherent to the film, such as vacuum formability, are significantly impaired, and the film cannot be used for the intended use of the PVC film. In addition, as a result of the compounding, the price rises, and there is a possibility that the use is restricted from this aspect.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve this problem, and as a result, have found that the above-mentioned problem can be solved by bonding a support film to a PVC film in a releasable manner.

That is, in the present invention, a solvent-based paint is coated on a composite film in which a PET (polyethylene terephthalate) support film is thermally preliminarily detachably attached to one side of a polyvinyl chloride resin film, and the temperature is set at 50 ° C to 160 ° C. An object of the present invention is to solve the above-mentioned problems by providing a composite film that has been passed through a drying oven and dried.

 Hereinafter, the present invention will be described in more detail.

PVC film has excellent workability, flexibility, coloring, printability, adhesion to other substrates, flame retardancy, etc.
Before vacuum forming, pressure forming, or laminating on other substrates, the process of printing, coating, or laminating other films and painting on the film Often go through. At this time, high temperature, high tension, in some cases, penetration of a solvent or the like occurs inevitably, and stretching or shrinking or deformation of the film occurs, and it is difficult to maintain the desired dimensions.

Therefore, in the present invention, the appropriate heating of the PVC film and the support film, by performing temporary bonding by thermal bonding under pressure conditions, to increase the resistance to heating and pulling,
Even if the composite film is subjected to printing, coating, and, in some cases, processing such as covering with a foam layer, it is possible to obtain a processed film with little dimensional change. After performing the above-described treatment of the PVC film, if the support film is peeled off, the PVC film that is not subjected to dimensional change or has extremely small dimensional change can be obtained in a state where the PVC film has been subjected to processing such as printing and foaming. .

The treated film thus obtained can be used as it is as a PVC film alone, for post-processing by a usual method, for example, woodworking of cabinets, coating on steel plates, and the like, in which the conventional PVC film has been used. it can.

As the PVC film used in the present invention, a film to which a plasticizer is added or a film to which no plasticizer is added can be used. Although the thickness of the PVC film is not particularly limited, it is generally about 20 to 500 μm, preferably about 50 to 200 μm.

The resin that can be used as the support film is not particularly limited as long as it has its own heat resistance, solvent resistance, and dimensional stability, can be temporarily attached to polyvinyl chloride, and can be easily peeled off. For example, resins such as polyester, polyamide, and polycarbonate can be used, but the most preferred is a polyester resin, and particularly preferred is a polyester resin comprising terephthalic acid or isophthalic acid and ethylene glycol (hereinafter referred to as a PET film).

The thickness of the support film depends on the thickness of the composited PVC film, but is usually 10 to 150 μm, more preferably 12 to 150 μm.
7575 μm, typically about 12-50 μm.

The temporary bonding of the PVC film and the support film may be any temporary bonding method as long as it is a composite method that can be easily peeled off after the processing because the PVC film and the support film are adhered to the extent that they do not peel during the processing of the PVC film. The most preferable method is a method using thermal temporary bonding. That is, by laminating the PVC film and the support film and pressing them under heating, the two can be easily temporarily pasted. Specifically, for example, temporary pasting can be performed by continuously passing between a heated mirror-surface drum and a pressing roller. When a PET film is used as the support film, the compression temperature is preferably about 140 ° C.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 (temporary thermal bonding) PVC film (manufactured by Riken Vinyl Industry Co., Ltd., thickness: 100μ)
m, width: 100 cm, plasticizer addition amount: 20 phr) and a PET film (manufactured by Unitika Co., Ltd., thickness: 25 μm) are stacked, and a metal roll and a rubber roll heated to 140 ° C. (nip) (Interval: 0.1 mm) to form a heat temporary laminated composite film (see FIG. 1). The peel strength of this temporary adhesive film was 5 g / inch (2.54 cm).

(Coating, heating test) To the composite film obtained as described above, a solvent-based paint (solid content: 20%, toluene: MEK = 3: 2) was wet
The film was coated to a thickness of 50 μm and passed through a drying oven set at a temperature as shown in Table 1 for 5 minutes, and then the shrinkage in the width direction of the film was measured (see FIG. 2).

For comparison, the result of performing the same treatment on the PVC film alone was also measured. Table 1 shows the results.

As can be seen from Table 1, the composite film of the present invention was able to significantly reduce the width shrinkage as compared with the PVC film alone.

(Removal of the support film) The composite film, which had been coated and dried as described above, was continuously rewound using a rewinder equipped with a biaxial winding device. Easily peeled off, and no damage or stretching occurred on the PVC film at this time (see FIG. 3).

(Application to plywood) The treated PVC film obtained as described above is applied to a plywood for building materials (Starwood) and an adhesive for general-purpose PVC laminated plywood (ethylene-vinyl acetate copolymer manufactured by Chuo Rika Co., Ltd.) (Emulsion type), it showed the same adhesive strength as the conventional PVC film for PVC plywood.

Example 2 To the coating material used in Example 1, azobisisobutyronitrile was added as a foaming agent so as to have a concentration of 1% by weight, and a coating was performed with a wet thickness of 100 μm. This was passed through a drying oven at 140 ° C. to obtain a PVC composite film having a foamed layer having a thickness of 250 μm. Width after cooling 1
The shrinkage per 00 cm was 18 mm.

On the other hand, the PVC film alone was cut in the drying oven, and a satisfactory product was not obtained.

〔The invention's effect〕

In the present invention, since the support film is temporarily attached to the PVC film in advance as described above, the PVC film does not shrink or deform even during the PVC coating or other treatment, and the support film is peeled off after the treatment. By doing so, it can be used as an original PVC alone. For this reason, P
Printing, coating, foaming, etc. can be performed freely without worrying about shrinkage of the VC film, and the range of applications can be expanded.

[Brief description of the drawings]

FIG. 1 is a view in which a PET film is temporarily bonded to a PVC film. FIG. 2 is a view in which a coating is applied on a PVC film. FIG. 3 is a view in which the PET film has been peeled off. 1: PVC film 2: PET film 3: Coating

Claims (1)

(57) [Claims] 1. One side of a polyvinyl chloride resin film,
A composite film obtained by coating a solvent-based paint on a composite film in which a PET (polyethylene terephthalate) support film has been thermally preliminarily removably bonded, and dried by passing through a drying oven set at a temperature of 50 ° C to 160 ° C.