JPH0318513B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for forming a concave pattern on the surface of a vinyl chloride film (or sheet). A variety of decorative sheets have been developed as decorative materials for buildings, vehicles, ships, furniture, musical instruments, cabinets, etc., but a decorative sheet with an arbitrary uneven pattern formed on the surface of the sheet has been developed to enhance the decorative effect. Are known. By the way, as a method for forming an uneven pattern on a sheet surface, various physicochemical unevenness forming methods using a liquid repellent have recently been proposed in place of expensive mechanical methods such as embossing. . That is, for example, Japanese Patent Publication No. 47-7154 discloses that an ink composition containing a liquid repellent such as silicone and a polymerization inhibitor such as hydroquinone in a normal printing ink composition is applied to the area where the concave pattern is to be formed. A method of forming a concave pattern by using the liquid repellent effect of the liquid repellent agent and the polymerization inhibiting effect of the polymerization inhibitor is performed by printing using a polymerizable resin paint, followed by applying a polymerizable top resin paint and drying it. Disclosed. However, since this method utilizes the shrinkage effect of the resin film based on the polymerization inhibiting effect of the polymerization inhibitor in addition to the liquid repellent effect of the liquid repellent, the liquid repellent state may vary depending on the curing conditions. This makes it difficult to obtain a completely satisfactory product. In addition, Japanese Patent Publication No. 52-2641 discloses that a concave pattern is created by adding a liquid repellent to both the printing of the area where the concave pattern is to be formed and the top coating of the entire surface including the printing layer using a normal ink composition. A formed decorative sheet is disclosed. but,
Since this method uses only the liquid repellent effect of a liquid repellent such as silicone, the surface condition of the area printed using an ink composition containing this agent may change depending on the type of substrate, printing conditions, etc. It is difficult to obtain a smooth and uniform surface condition, and there is virtually no surface protective layer in the areas where the top coat is repelled by the action of the liquid repellent, that is, in the concave areas.
In particular, the solvent resistance, water resistance, and abrasion resistance of this portion are poor, making it difficult to obtain a product with satisfactory practicality. Furthermore, as another method using a liquid repellent, Japanese Patent Application Laid-Open No. 57-31573 discloses that a curable ink composition containing a liquid repellent is applied to the ink used for printing the area where the concave pattern is to be formed, and then thermally cured. Discloses a method of forming concave portions by making the top coat of the area coated with the curable ink composition liquid repellent by heating at a temperature equal to or higher than the melting temperature of the top coat after applying the mold paint. has been done. However, when this method is applied to a vinyl chloride film to form concave portions, the melting temperature of the top coat paint or a temperature higher than the softening temperature of the vinyl chloride film is generally higher than the softening temperature of the vinyl chloride film. The vinyl film shrinks and unevenness occurs on the film surface, so-called "sagging phenomenon", making it impossible to obtain a practical product. In view of the above-mentioned drawbacks of the conventional method when forming a concave pattern on the film surface using a liquid repellent, the inventors of the present invention have discovered that even when a vinyl chloride film is used as a material, there is no sharp pattern on the surface. In addition to being able to form a concave pattern, the surface other than the concave portions is smooth and the concave pattern is excellent in appearance, and the entire surface of the film, including the concave portions, has excellent solvent resistance, water resistance, abrasion resistance, etc. The present invention was developed as a result of intensive research aimed at providing a method for forming a concave pattern with excellent surface characteristics. That is, in the present invention, after forming a printed pattern on the surface of a vinyl chloride film, a curable ink composition containing a liquid repellent is used to form a printed layer corresponding to a desired concave pattern, and then printed. A method for forming a concave pattern on the surface of a vinyl chloride film, the gist of which is to apply an ultraviolet curable paint with a viscosity of 100 to 5000 cps over the entire surface of the film to a cured film thickness of 3 to 50 μm, and then irradiate it with ultraviolet rays. ,
The concave pattern is formed by the ultraviolet curable paint coated on the printing layer made of a curable ink composition containing a liquid repellent, which is liquid repellent. The method of the present invention will be explained in detail below with reference to the drawings. That is, as shown in FIG. 1, a printing layer 2 is applied to the surface of a vinyl chloride film 1 using a conventional ink composition.
to form. Next, a printing layer 3 corresponding to a desired concave pattern is formed using a curable ink composition containing a liquid repellent. Next, an ultraviolet curable paint layer 4 is formed on the entire surface of the area printed in multiple colors using the above method. Next, preferably for 5 seconds or more, the ultraviolet curing paint layer 4 of the printed layer 3 is repelled, and a concave pattern 5 is formed on the printed layer 3 as shown in FIG. The coating layer 4 is then cured by irradiation with ultraviolet rays, thereby obtaining a film in which a concave pattern is formed on the surface of the vinyl chloride film according to the present invention. First, vinyl chloride film 1 provided in the present invention
The base material for manufacturing may be either polyvinyl chloride or a copolymer mainly composed of vinyl chloride, and monomers to be copolymerized include vinyl ester, vinyl ether, acrylic acid or methacrylic acid, and their Examples include esters, maleic acid or fumaric acid, or esters thereof, maleic anhydride, aromatic vinyl compounds, vinylidene halides, acrylonitrile or methacrylonitrile, and olefins such as ethylene and propylene. Moreover, various plasticizers and additives are added to these vinyl chloride resins as necessary. Plasticizers are used to adjust the flexibility and hardness of molded products, and include dioctyl phthalate,
Phthalate esters such as zabutyl phthalate and butylbenzyl phthalate, dioctyl adipate,
Fatty acid esters such as dibutyl sebacate, phosphate esters such as tricresyl phosphate and triphenyl phosphate, epoxidized oils such as epoxidized soybean oil and epoxidized linseed oil, acetyl tributyl citrate, acetyl trioctyl citrate, etc. Various examples include citric acid esters and other polyesters. Additives used to improve properties such as lubricity and stability include metal salts of carboxylic acids such as calcium stearate, zinc stearate, lead stearate, barium stearate, and cadmium stearate. ,
Organotin compounds such as tribasic lead sulfate, dibasic lead phosphite, dibutyltin dilaurate, octyltin malate, octyltin mercaptite, ester compounds such as butyl stearate, and ethylene bisstearamide. Examples include fatty acid amides, higher fatty acids and their esters, and polyethylene wax. In addition, various additives used in the molding of vinyl chloride resins include well-known fillers, reinforcing agents, heat resistance improvers, antioxidants, ultraviolet absorbers, antistatic agents, foaming agents, anti-drop agents, and pigments. , dyes, crosslinking aids, etc. In addition, the method for forming a vinyl chloride film is as follows:
Means conventionally employed in molding vinyl chloride films, such as calender molding, extrusion molding, inflation molding, and casting molding, can be used instead. Furthermore, a composite material obtained by forming a vinyl chloride film with other vinyl chloride films or materials such as metal, wood, paper, or synthetic resin may also be used. Next, as the ink composition for forming the printing layer 2, acrylic, vinyl chloride, EVA,
An ordinary printing ink composition prepared by dispersing pigments and dyes in a vehicle that has good adhesion to vinyl chloride resins such as PVC and dissolving them in a solvent can be used. Next, the curable ink composition containing a liquid repellent for forming the printing layer 3 is one in which a liquid repellent is added to a vehicle that is curable at a temperature below the softening temperature of a vinyl chloride film. A composition is used in which the ink layer itself is stable and can form a film with good surface properties such as solvent resistance, abrasion resistance, weather resistance, and heat resistance. Such ink compositions include various curable ink vehicles as the vehicle, such as two-component curable inks that are cured by reaction of polyester polyols or polyether polyols with isocyanates to form polyurethane resins, epoxy resins and polyamides, Epoxy-based curable inks that cure by reaction with polyamines or acid anhydrides; thermosetting inks made by adding a polymerization initiator such as peroxide and a polymerization catalyst such as cobalt naphthenate to a mixture of unsaturated polyester and styrene monomer; and melamine. Thermosetting ink made by adding paratoluenesulfonic acid to a resin or urea resin and alkyd resin, or electron beam or ultraviolet curing ink made by adding a photosensitizer such as benzophenone and benzoin ether to epoxy acrylate or urethane acrylate. A composition obtained by using a vehicle, adding known additives such as plasticizers, stabilizers, dispersants, and fillers, and coloring agents such as dyes and pigments, and then adding a solvent and a diluent and kneading. things can be used. These curable ink compositions are usually used in a two-component form, and therefore a method is adopted in which a reaction catalyst and a reaction accelerator are added to the ink composition immediately before use. Further, as the liquid repellent added to the above-mentioned curable ink composition, conventionally known materials such as silicone, wax, fluororesin, etc. can be used. Such a liquid repellent may be added to the ink composition in advance, or
It may be added just before the action. The amount added is preferably 5 to 30% by weight based on the dry weight of the ink composition. The curable ink composition containing the above-described liquid repellent is printed on a vinyl chloride film by a known method, such as a gravure printing method, an offset printing method, a letterpress printing method, or a screen printing method, in the same manner as ordinary printing inks. However, when the liquid repellent-containing ink is an electron beam curing type or ultraviolet curing type ink as described above, after applying the above ink, the printing layer is cured by irradiation with an electron beam or ultraviolet rays. Apply the top coat described above. Furthermore, when an ink containing a liquid repellent other than those mentioned above is used, after coating, the solvent is evaporated and the ink is dried to such an extent that no blocking occurs, and then a top coat is applied. Next, in the present invention, an ultraviolet curing type paint that forms a transparent surface protective layer is used as the top coat. Such UV-curable paints include epoxy acrylate, acrylic urethane, polyester prepolymers, etc., with liquid monomers as diluents, crosslinking agents, sensitizers, and dyes and matting agents added to an extent that does not impair transparency. be done. These UV-curable paints generally have a high viscosity, and when the viscosity is high, liquid repellency occurs on the printing layer of the curable ink containing a liquid repellent, but as shown in FIG. Top coat layer 4 with convex parts
The vicinity of the boundary 6 is raised, and the appearance is sharp and a good concave portion cannot be formed. The viscosity of the ultraviolet curing paint that forms good concave portions 5 when sharpened is
It was found to be 100-5000 cps, preferably 200-2000 cps. In addition, as a method of adjusting the viscosity within the above range, the usual method of adding a low molecular weight polymer may not provide the desired performance of the cured film, so a solvent that is compatible with the ultraviolet curable paint is used. A sharper concave portion is formed by adding . Furthermore, since UV-curable paints generally have poor affinity for the base material, vinyl chloride film, it is desirable to use a solvent in order to impart affinity to the base material. Any commonly used solvent may be used as long as it has an affinity for ultraviolet curable paint and vinyl chloride film, but it should be noted that it has good liquid repellency for the top coat and forms sharper concave areas. In order to achieve this, it is desirable to use ethyl acetate or a solvent containing ethyl acetate as a main component. The amount of solvent added can be adjusted within the range of 5 to 50% by weight to maintain the viscosity within the above-mentioned range. By using a solvent, the solvent penetrates into the vinyl chloride film and the curable ink layer, activating the surface, and the adhesion of the ultraviolet curable paint to these layers becomes stronger. Next, the coating amount of the top coat made of ultraviolet curable paint is 3 to 50μ, preferably 5 to 20μ in film thickness after curing, and the sharpness and depth of the recesses are
It can be adjusted as appropriate depending on the required surface properties. If the coating amount is less than 3μ, the same phenomenon as when the viscosity is low occurs, i.e., no liquid repellency occurs or the liquid repellency is insufficient, and if the coating amount exceeds 50μ, the viscosity is high. A similar phenomenon occurs, that is, a bulge occurs at the boundary between a concave part and a convex part,
This is not desirable because liquid repellency may not occur. If the base material is a permeable material such as paper, the coating amount will have little effect because the top coat will permeate. If not, applying the coating within the above range is an important factor in forming sharp recesses. The above-mentioned top coat can be applied by a conventional coating method such as roll coating, gravure coating, bar coating, air knife coating, flow coating, or spray coating. Next, after applying the top coat, it is cured by irradiating it with ultraviolet rays, but it is desirable that this irradiation be carried out after 5 seconds or more have elapsed after application. If it takes less than 5 seconds, the appearance quality may be poor due to insufficient formation of the recess, the edges of the recess being raised, or the coated surface other than the recess being not smooth. Easy to occur. Furthermore, in the present invention, when a solvent is added to the ultraviolet curable paint, the temperature is below 100°C, for example.
The coated layer is heated to a temperature of 40 to 60°C to completely volatilize the solvent. This heating maintains the top coat at a relatively low viscosity, and the formation of sharp concave portions and the smoothing of the coated surface other than the concave portions further proceed. By being irradiated with ultraviolet rays in this state, the top coat is cured and a concave printed pattern with sharp concave areas is formed, and the coated surface other than the concave areas is smooth and a product with excellent appearance quality is obtained. As explained in detail above, according to the present invention, a printed layer corresponding to a desired concave pattern is formed on the surface of a vinyl chloride film on which a normal printed pattern is applied using a curable ink composition containing a liquid repellent. is formed, and then the viscosity is set to 100~100 on the entire surface of these printed layers.
The UV curable paint adjusted to 5000 cps was applied to a cured film thickness of 3 to 50 microns, and then UV rays were irradiated, so the surface characteristics of the resulting product were that the curable ink was applied to the concave areas, and the UV rays were applied to other areas. Since they are each coated with a cured paint, they are extremely excellent, and the recessed portions are sharply formed, while the surfaces other than the recessed portions are smooth, making it possible to obtain a product with extremely good appearance quality. Further, by adding a solvent, particularly ethyl acetate, to the ultraviolet curable paint and adjusting its viscosity within the above range, there are advantages such as the ability to obtain a product with good adhesion of the paint to the vinyl chloride film. Therefore, by bonding the vinyl chloride film obtained by the process of the present invention to various base materials using adhesives or the like, it can be used as a decorative material for buildings, vehicles, ships, furniture, cabinets, etc. with extremely high design effects. A decorative board with high fastness is obtained. Example 100 parts by weight of vinyl chloride resin, 20 parts by weight of dioctyl phthalate (DOP) as a plasticizer, 5 parts by weight of epoxidized soybean oil, 3 parts by weight of Cd-Ba stabilizer (mixture of cadmium stearate and barium stearate) A base material prepared by adding 5 parts by weight of a brown pigment to the above mixture was calender-molded to prepare a vinyl chloride film with a thickness of 0.2 mm. Vinyl ink (Dainichiseika Kogyo Co., Ltd.) is applied to this film.
Co., Ltd.) to perform gravure printing with a wood grain blur pattern plate, and then gravure print the wood grain pattern using a curable ink containing a liquid repellent with the following composition.
A printed vinyl chloride film was obtained. Acrylic polyol 20 parts by weight Handle 15 Acetate 60 Silicone 5 Isocyanate prepolymer 10 110 The above printed vinyl chloride film was coated with an ultraviolet curable paint having the following composition under the conditions shown in Table 1. After curing by irradiating with ultraviolet light (80 W/cm x 1 lamp), the liquid repellency, appearance and adhesion of the ultraviolet curable paint were evaluated by cellophane tape test. The results are shown in Table 1 and Figure 4. Composition of UV-curable paint Urethane acrylate 64 parts by weight Benzophenone 2 Henzoin ether 3 Silica matting agent 5 Ethyl acetate 25 Silicone 1 100

[Table] Note: In the table, ◎ indicates very good condition, ○ indicates good condition, △ indicates somewhat good condition, and × indicates poor condition.
show.
That is, in FIG. 4, a to f indicate the surface condition after coating and curing corresponding to the upper section of Table 1, respectively, and the surface condition in FIG. It is clear that the surface condition is much better than that shown in FIGS. 4b to 4f, which correspond to No. 5.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-section showing the state of a vinyl chloride film before irradiation with an ordinary printing layer, a printing layer using a liquid repellent-containing curable ink, and an ultraviolet curable paint layer formed by the method of the present invention. Figure, 2nd
The figure is a schematic sectional view after irradiation with the same ultraviolet rays, Figure 3 is a schematic sectional view showing the finished surface state when the viscosity of the ultraviolet curable paint is high, and Figure 4 is the finish corresponding to the example and comparative example of the present invention. A schematic cross-sectional view showing the surface condition is shown. 1... Vinyl chloride film, 2... Print layer made of a normal ink composition, 3... Print layer made of a curable ink composition containing a liquid repellent, 4... Ultraviolet curable paint layer, 5... Concave shape Part 6...The exciting part.

Claims (1)

[Claims] 1. After forming a printed pattern on the surface of a vinyl chloride film, a curable ink composition containing a liquid repellent is used to form a printed layer corresponding to the desired concave pattern, and then printing. Formation of a concave pattern on the surface of a vinyl chloride film characterized by applying an ultraviolet curable paint with a viscosity adjusted to 100 to 5000 cps to a cured film thickness of 3 to 50 μm on the entire surface of the film, and then irradiating it with ultraviolet rays. Method. 2. The method according to claim 1, wherein the viscosity of the ultraviolet curable paint is adjusted by adjusting the amount of ethyl acetate added. 3. The method according to claim 1 or 2, wherein the ultraviolet irradiation is carried out after 5 seconds or more have elapsed after the application of the ultraviolet curable paint.