JPS6228464B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a peel-off film that can immediately produce various original images by providing a colored synthetic resin film layer on a transparent support, making incisions in the film layer, and peeling off the necessary parts. It is. More specifically, the present invention uses polyvinyl acetal resin, a polyester resin compatible therewith, and This relates to a peel-off film that uses light-shielding dyes and pigments as its main ingredients. Traditionally, in the printing plate-making process, light-shielding materials are used on transparent film supports made of synthetic resin when combining and composing a large number of original images such as line drawings and tone drawings, or when photographing or trimming a part of an original image. A peel-off film provided with a colored synthetic resin layer is used as a mask material. In recent years, with the spread of automatic drawing machines, it has become possible to create fairly complex original drawings such as printed circuits using the peel-off film simply by replacing the writing implement in the head with a cutter or the like. Figure 1 A, B, and C show the cross section and principle of use of this type of peel-off film. Using this peel-off film, one pattern corresponding to the peeled part can be obtained. The characteristics that this peel-off film should have are:
Not only does the colored synthetic resin film layer (hereinafter simply referred to as the resin layer) have good cutting properties and peelability from the transparent support, but also the resin layer of the peel-off film can be removed after peeling off a desired portion of the resin layer. The transparent support is designed to prevent the remaining resin layer from peeling off easily when the side is rubbed by hand, and to prevent the remaining resin layer from lifting off from the transparent support due to impacts during various handling. The adhesion between the support and the resin layer must be good, and the release film itself must be formed so that it will not be torn off during the process of peeling off the resin layer by making score lines. The strength of the peel-off film must be appropriately high, the adhesiveness of the peel-off film must be low to prevent small pieces of film from remaining on the surface of the peel-off film when it is peeled off, and the resin must be resistant to heat, light, and other factors. For example, the layer does not deteriorate. Conventionally, the materials used for the resin layer of peel-off films include vinyl chloride resin, vinyl chloride copolymer resin, nitrocellulose, and other resins with plasticizers added, but the surface of the resin layer is highly sticky and Peel strength was low and workability was difficult. In addition, in order to improve such defects, a mixed resin of polyurethane resin and cellulose acetate resin is used for the resin layer, or a rubbery material such as NBR and vinyl chloride-vinyl acetate copolymer resin are used (Japanese Patent Publication No. 51-25478). It is also proposed to use a mixture with
104902), and although the stickiness and releasability of the resin layer surface have been considerably improved, it is possible to make cuts in the desired parts of the resin layer with a cutter knife, etc., peel it off, and then wrap the peel-off film. However, there are problems such as the remaining resin layer lifting from the transparent support due to impact, strain, etc. applied to the film during various handling such as storage or use as a mask. It cannot be said that the performance as a peel-off film is fully satisfied. The present inventors have conducted intensive research on the material of the resin layer in order to eliminate the above-mentioned drawbacks, and as a result, they have found a new material composition that does not have the above-mentioned drawbacks, and have completed the present invention. That is, the present invention is a peel-off film characterized in that a colored synthetic resin film layer comprising a polyvinyl acetal resin, a polyester resin compatible therewith, and a dye and pigment as main components is provided on a transparent support. It has an excellent balance of strength, removability and adhesion, and has a non-sticky surface, making the film easy to cut with a cutter knife, etc., and the resin layer that remains after being peeled off at the required part is transparent and supports it during various handling. To provide an extremely excellent peel-off film that does not have to worry about lifting from the body. The transparent support used in the peel-off film of the present invention includes polyethylene terephthalate,
Mention may be made of transparent plastic films of polypropylene, polyethylene, polyvinyl chloride, polystyrene, polycarbonate, triacetate and the like. In particular, biaxially stretched polyethylene terephthalate film has excellent strength, dimensional stability,
It is preferable because it is excellent in terms of transparency and the like. On the other hand, the polyvinyl acetal resin used for the colored synthetic resin film layer includes polyvinyl butyral, polyvinyl formal, etc., and the type of aldehyde used for acetalization and the raw material polyvinyl The molecular weight, degree of saponification, and degree of acetalization of vinyl acetate are selected. For polyvinyl butyral, the butyral component is 70 to 85% by weight, and the degree of polymerization is 200 to 2500. For polyvinyl formal, the formal component is 75 to 85% by weight.
The degree of polymerization is preferably in the range of 300 to 1100. Next, the polyester resin can be selected from a wide range of general linear saturated polyester resins used for paints and adhesives, as long as it is compatible with polyvinyl acetal resin. The molecular weight is preferably 5,000 or more and 30,000 or less, although it depends on the type of polyester raw material. If this upper limit is exceeded, the compatibility with the polyvinyl acetal resin will generally be poor, and the liquid viscosity will be high, which is unfavorable in terms of coating properties.Below this lower limit, the mechanical strength of the formed film will be poor, and problems such as stickiness may occur. easy. The mixing ratio (weight ratio) of these polyvinyl acetal resin and polyester resin is not particularly limited, but is in the range of 90:10 to 50:50, especially 80:
A range of 20 to 60:40 is desirable. 90 with this mixing ratio:
If the amount of polyester resin is less than 10, the adhesion to the transparent support will be poor if it is a plastic film, and there is a risk that the resin layer other than the release film will peel off easily. However, if the amount of polyester resin increases, the surface of the resin layer becomes sticky, and the adhesion to the transparent support becomes excessive, making it difficult to peel off the desired area, and the elongation of the peeling film becomes large, eventually making it easy to break the film. Both of these results are unfavorable in terms of workability. It is also effective to mix resins other than those mentioned above in order to more finely control physical properties such as hardness of the resin layer film. For example, phenolic resins, nitrocellulose, etc. are effective in improving the hardness of the film, and depending on other desired physical properties, various resins may be mixed and used within a range that does not deteriorate the above performance. As the coloring agent for imparting light-shielding properties, dyes or pigments and mixtures of dyes and pigments can be used. As the dye, it is advantageous to use an oil-based dye that has good compatibility with polyvinyl acetal resin and polyester resin, has little change in color tone or fading due to factors such as heat and light, and can satisfy the necessary light-shielding properties. , there are no particular limitations on its color tone or structure. Pigments having the same properties as the dyes can be advantageously used, but they can be selected from a wide range of oil-based dispersion types that have particularly good miscibility with the resins mentioned above. The amount of the colorant to be added may be determined so as to satisfy the necessary light-shielding properties within a range that does not significantly reduce the releasability, adhesion, film strength, etc. of the resin layer. In addition to the above ingredients, the colored synthetic resin film layer (resin layer) also contains a matting agent to improve slipperiness and mattness, an antistatic agent to prevent the generation of static electricity, and a transparent support for the resin layer. When disposing it on the body, a leveling agent, antifoaming agent, surfactant, etc. may be added as necessary to improve the coating properties. In the colored synthetic resin film layer of the present invention, the polyvinyl acetal resin contributes to the releasability of the resin layer, the strength of the release film, the elimination of surface stickiness, and the sharpness of the film, while the polyester resin mainly contributes to the adhesion of the resin layer, the strength of the release film, and the sharpness of the film after removal of the release film. This is useful in preventing the remaining resin layer from lifting up, but the combined use of both resins is expected to have an unexpected synergistic effect on these properties. It goes without saying that the dye and pigment provide light-shielding properties to the resin layer. In order to further clarify the present invention, Examples are shown below, but the present invention is not limited thereto. Examples 1 to 3 and Comparative Examples 1 to 2 A coating solution having the composition shown in Table 1 was applied to one side of a biaxially stretched polyethylene terephthalate film with a thickness of 100 μm using a roll coater and dried to form a film with a thickness of 15 μm. A colored synthetic resin film layer was formed.
Each component of the coating liquid composition was prepared as follows. [Components of coating solution] (1) Polyvinyl formal resin (Denka Formal #200: Denki Kagaku Kogyo Co., Ltd.)
(Manufactured by Fuji Photo Film Co., Ltd.) Methanol/Toluene = 30/70 15% solution (2) Polyester resin (Stafix PLC1050: Manufactured by Fuji Photo Film Co., Ltd.) MEK/Toluene = 50/50 30% solution (3) Phenol resin (Resistop PSF2803: Gunei Manufactured by Kagaku Co., Ltd.)
MEK/Toluene = 50/50 50% solution (4) Dye (Neosapon Red GE/Neosapon Orange RE = 60/40: manufactured by BASF) MEK 30% solution Results of Examples 1 to 3 and Comparative Examples 1 to 2 They are summarized in Table 1. In Examples 1 to 3, there is no stickiness on the film surface, and the adhesiveness between the support and the film and the strength of the film are excellent. Furthermore, when a cut line was made on the film using a cutter knife and the required portion was peeled off, the film showed extremely good sharpness and peelability. Peel strength can be adjusted by changing the blending ratio of resins. Comparative Examples 1 and 2 are examples in which polyvinyl formal resin or polyester resin was used alone, and Comparative Example 2 had the disadvantage that it did not have removability, and Comparative Example 1 had the disadvantage that it easily peeled off in areas other than the required parts. Ta. Comparative Example 3 The following coating solution was prepared. [Coating liquid] Part by weight vinyl chloride/vinyl acetate (87/13 copolymer) 64 MEK 25% solution acrylonitrile-butadiene rubber (acrylonitrile content 33%) 27 MEK/toluene = 90/40 20% solution dye (Neozaponeredo GE/ Neozapon Orange RE=60/40) 5 Solvent (ethyl cellosolve) 15 The above coating solution was applied and dried under the same conditions as in Examples 1 to 3 and Comparative Examples 1 to 2, and the resulting peel-off film was The properties are also listed in Table 1.
As is clear from the table, the colored resin film layer produced by the conventional technology exhibits relatively good releasability. However, if some impact or strain is applied to the film after the desired portion has been peeled off, the remaining resin layer may be particularly damaged. This had the disadvantage that the edge (boundary between the cut line and the peeled part) easily lifted up. Furthermore, if this material is exposed to ultraviolet light for a long period of time, the strength of the resin layer film will deteriorate significantly and the film will easily break during peeling, making it impossible to peel it off. Furthermore, when exposed to high temperatures, the adhesion of the resin layer to the support increased to an extreme degree, and there was also a phenomenon that the resin layer could not be peeled off. Example 4 In Example 1, instead of the polyvinyl formal resin, polyvinyl butyral resin (Eslec BM-S: manufactured by Sekisui Chemical Co., Ltd.) was used, and as the polyester resin, 142 parts by weight of terephthalic acid was used instead of Staffix PLC1050. A saturated polyester resin having a molecular weight of 7000 obtained by polycondensing 142 parts by weight of isophthalic acid and 270 parts by weight of 1,4-butanediol using potassium titanyl oxalate (0.3 parts by weight) as a catalyst was used. This peel-off film has sufficient light-shielding properties, no stickiness on the surface, and good peelability, and the remaining resin layer in areas other than the required areas does not easily lift off from the support, so it fully satisfies the intended performance. It was possible. 【table】

[Brief explanation of the drawing]

FIG. 1A is a cross-sectional view of a peel-off film to which the present invention is applied, and FIGS. 1B and 1C are diagrams showing the principle of use of the same as above, where B shows the state with a score line and C shows the peeled state, respectively. In the figure, indicates the transparent support, indicates the colored resin film layer (resin layer), indicates the score line, indicates the peeled part,
is a release film.

Claims (1)

[Scope of Claims] 1. A colored synthetic resin film layer comprising a polyvinyl acetal resin, a polyester resin compatible therewith, and a light-shielding dye and pigment as main components is provided on a transparent support. Peel-off film. 2 The mixing ratio of polyvinyl acetal resin and polyester resin that is compatible with it is 90:10 ~
The peel-off film according to claim 1, which has a weight ratio of 50:50.