JPS6342589B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for obtaining a desired transparent pattern on a chemical matte film. Generally, the sandblasting method and the chemical coating method are known as methods for obtaining a writing-friendly tracing film by processing the surface of a transparent film into a matte finish. The matte surface has extremely minute irregularities of about 0 to 2 microns, which diffusely reflects light, giving it an opaque and matte feel, and at the same time provides good writability. The degree of the sand mat surface obtained by the sandblasting method can be adjusted by adjusting the particle size of the sand to be blasted, the strength of the blast at the time of blasting, etc. A method for obtaining a sandblast film with a transparent pattern by applying the sandblasting method was disclosed in Japanese Patent Application Laid-Open No. 1973-1999.
-79274, Utility Model Publication No. 37-14197, etc. The patterned matte film obtained by these methods differs decisively from the pattern obtained by general printing methods: (1) Since printing ink is not used, the transparent and matte parts are different from each other. There is almost no difference in level between them, and they are almost on the same plane. (2) The pattern cannot be erased even by wiping it with an organic solvent. (3) Transparent patterns cannot be copied using PPC (electronic copying) or diazo methods. These are points such as. Based on the feature mentioned in item (1) above, for example, even when a film with such a pattern is tightly wound, or when a large number of films are placed one on top of the other and placed under force, there are almost no unevenness, so there is no difference between each other. There is no possibility of mold transfer to other adjacent film surfaces and loss of flatness. Furthermore, due to the feature of item (2), for example, certain patterns such as watermarks on banknotes cannot be erased, so it can be expected to have a counterfeiting function in important documents and drawings. Furthermore, even when another layer of organic solvent-based overcoat processing is performed on this surface, or when an organic solvent-based adhesive is applied, problems such as pattern blurring do not occur.
Also, based on the special colors in item (3), even if you copy originals that use paper with transparent patterns as grids or ruled lines,
Since these lines do not appear, only the written image can be clearly copied and is easy to read. As mentioned above, it has features that are extremely useful. The present inventors applied the chemical matte method to study in order to obtain a matte film with a transparent pattern having the same characteristics as the sandblasting method, and as a result, they finally completed the method of the present invention. In the chemical matting method, the degree of matting can be freely adjusted by selecting the white pigment. Generally, the surface of a chemical matte film is made of a curable film-forming resin in order to obtain resistance to organic solvents and film toughness, and a white pigment is further mixed in to give a matte feel and writability. A method is adopted in which a coating liquid adjusted to have a viscosity and solid content concentration of 100% is uniformly applied to the film surface and dried. If this step is referred to as the first step, the method discovered by the present inventors for forming an arbitrary transparent pattern on the obtained mat surface is as follows. The curing of the resin in the first step is completed in an incomplete state. A desired pattern is printed on the surface using a transparent curable resin solution containing no white pigment as ink, and then dried. Named the second step consisting of a combination of the above and the above, it is necessary to completely cure the curable resin. In the method of the present invention, since the curing in the first step is incomplete, the chemical mat layer is swollen by the solvent of the transparent resin solution in the second step, and the transparent resin solution penetrates into the layer. The surface of the white pigment existing on the surface of that part is coated with a transparent resin film. According to the method discovered by the present inventors, the transparent hardening resin printed in a pattern in the second step fills in the microscopic irregularities on the surface of the chemical mat, improving the matt feel and opacity of the area. After erasing,
At the same time, some of the resin penetrates into the pine layer and then
It hardens and is fixed as one with the mat layer. In this case, once the resin has completely cured in the first step, the transparent resin solution in the second step does not penetrate into the matte layer and remains on the surface to form a film, resulting in a matte feel and opacity. Although it is possible to erase this area with an eraser, it not only bulges in that area and creates an excessive step between it and other areas, but it also does not essentially become integrated with the matte layer and the adhesion is incomplete. If you rub it too hard, rub it with your hands, or forcefully peel off the cellophane tape, the film will be removed and it will lose its practical value. Further explanation will be given below with reference to Examples and Comparative Examples. Examples 1 and 2 and Comparative Example 1 Table 1 was applied to one side of a surface-treated polyester film (manufactured by Toray Industries, Q type, 50μ).
Meyer Bar (RDS No.18)
It was coated using. The coating weight was 5.6 g/m ² after drying.

[Table] The following three samples were prepared by changing the drying conditions. Sample Dry at 90℃ for 30 seconds Incomplete sample Dry at 110℃ for 60 seconds Incomplete sample Dry at 130℃ for 60 seconds Complete After drying, immediately cut out a piece of the sample and rub the surface with gauze soaked in methanol to remove the matte layer. The number of times it took for the surface of the polyester film to become exposed was investigated and the results were as follows. Sample 2 times 〃 15 times 〃 70 times Next, 1.5 times on the mat surface of the sample
Example 1, Example 2, and Comparative Example 1 were printed using a gravure method with a pattern in which alphabetical letters within a size of mm x 1.5 mm were lined up on the entire surface. (Plate depth: 35μ) A transparent resin solution having the composition shown in Table 2 was used as the printing ink.

[Table] The drying conditions after printing were all 130°C and 60 minutes.
In Examples 1 and 2, the letters appeared as clear transparent patterns, and even when the surface was rubbed with gauze containing toluene and methanol, the clarity of the letters did not change at all. On the other hand, in Comparative Example 1, although the clarity of the letters was the same, when the cellophane tape was attached and then strongly peeled off, the letters were removed by the cellophane tape. Application Example A chemical matte layer was coated on both sides of a 50μ thick polyester film in the same manner as described in Example 2, and each side was dried at 110°C for 60 seconds. Therefore, the first coated surface is coated for a total of 120 seconds.
It will be dry. Finally, section printing is performed on the dried chemical matte surface using a gravure printing plate with a grid pattern of 10 mm x 10 mm.
Dry. (Plate depth 35μ) The same ink as in Example 1 and Example 2 (Table 2) was used, and the drying conditions after printing were
The temperature was 130°C for 60 seconds. The obtained chemical matte film was a sectional film having a grid of 10 mm x 10 mm as a transparent pattern on one side, and had equally excellent writing properties on both sides. Even when I rubbed the section pattern surface with an eraser or rubbed it strongly with methanol-soaked gauze, the condition of the surface did not change at all. Furthermore, even if you copy a manuscript drawn on this chemical matte film onto high-quality paper using a Xerox 3500, the section pattern will not appear on the copy at all, and only the drawing lines will be clearly copied, resulting in an extremely legible drawing. Summer. Similarly, this manuscript was diazocopied using a dry diazocopy machine (Ricoh SM-1500), but the section pattern was not copied at all, resulting in an extremely legible drawing. Comparative Example 2 Using a liquid having the same composition as the chemical mattifying liquid shown in (Table 1) of Examples 1 and 2, but with a higher viscosity by adjusting the solid content concentration to 35%,
By using the plate with the grid pattern used in the application example,
Gravure printing was performed directly on one side of a 50μ thick transparent polyester film. Drying was carried out at 130°C for 60 seconds to completely cure the chemical mat layer. Cut this film with the chemical matte section pattern into a 10cm x 10cm square, and cut out a piece of transparent polyester film of the same size.
Three sheets were stacked one on top of the other to form a sandwich sandwich, and a load of 2 kg was applied to the entire surface, and the sheets were left in a constant temperature dryer at 40°C for 24 hours. As a result, the unevenness of the pattern was transferred to the surface of the transparent polyester film that was in contact with the grid pattern surface of the chemical mat, and the flatness was impaired.

Claims (1)

[Claims] 1. A chemical matte coating solution consisting of a solvent, a curable film-forming resin, and a white pigment is coated or printed on the surface of a transparent film, and after drying to the extent that the resin in the coating solution is still incompletely cured. A method for producing a chemical matte film with a transparent pattern, in which a desired pattern is printed on the surface using a transparent resin solution consisting of a solvent and a curable resin.