JPS6227377B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a highly efficient and effective method of creating textured patterns using ultraviolet energy. Conventionally, various methods for creating an uneven pattern have been proposed. The most commonly used method is to use an embossing plate to perform pressure embossing, but this method requires a lot of time and money to create the embossing plate, such as creating unevenness on a metal roll. In addition to this, there were also problems such as it was extremely difficult to synchronize the pattern and the unevenness. In order to overcome these drawbacks, a method has been proposed in which a concavo-convex pattern is formed without mechanical embossing as described above. Among these methods, one of the methods that uses ultraviolet curing paint is to create a mask plate that matches the pattern using positive film or negative film, and then overlap the mask plate to match the pattern.
There is a method of creating unevenness by irradiating ultraviolet rays from above to vary the curing speed of the paint. Although this method solves the problems associated with the previous mechanical embossing method, it has drawbacks such as the mask plate being expensive and the registration requiring manual labor for each sheet, resulting in poor efficiency. Another method is to create unevenness that matches the pattern by combining a paint containing an organic blowing agent such as an azo or nitroso type or an inorganic blowing agent such as sodium bicarbonate with an ink that has a foaming suppressing effect. There is a way. Since the foaming agent used in this method is a heating foaming agent, it generally requires a thermal history of 150°C or higher, and cannot be used unless the material can withstand that heat. For example, PVC sheets and the like that are not heat resistant cannot withstand the temperature during heating and foaming without a support such as paper.
Further, since foaming requires a certain heating time, workability is not good. For example, for masodicarbonamide, the temperature is 160 to 210℃.
30 to 120 seconds are required. The present invention has been made to solve these various problems. That is, an object of the present invention is to provide a novel method for extremely efficiently and effectively creating a concavo-convex pattern that is in sync with a picture using a paint containing a photofoaming agent and ultraviolet energy. An example of the present invention will be described with reference to the drawings. As shown in FIG. For the purpose of illumination, a pattern is formed on the foamable coating film 2' using, for example, a light-transmitting ink 3 and a light-shielding ink 4, as shown in FIG. Next, as shown in FIG. 3, a surface resin layer 5 made of a light-transmitting paint is provided. Thereafter, as shown in Figure 4, by irradiating the entire surface with light, the photofoaming agent in the area A below the translucent ink is decomposed and foamed, forming the convex part B, and the area C below the light blocking ink is exposed to light. This is a method of creating a concave-convex pattern that matches the pattern by forming concave portions without decomposing and foaming. Note that this description is merely an example of the present invention, and as will be described later, there are various methods for selectively irradiating light, and the present invention is not limited to the above-mentioned examples. Next, embodiments and configurations of the present invention will be described.
Base materials include paper, synthetic paper, resin-mixed paper, nonwoven fabric,
An essential base material such as a resin film or plywood, a fiberboard such as a hardboard, an inorganic base material such as an asbestos slate board, or a metal plate can be used as desired. Furthermore, these base materials can be used as base materials after being subjected to fillers, pretreatment, coloring, designs, etc., as required. Paints containing photofoaming agents are paints mixed with photofoaming agents, and photofoaming agents include nitrogen compounds that generate nitrogen gas when irradiated with light and halogen compounds that generate halogen gas. Azo compounds and azide compounds can be used as nitrogen compounds, and examples of azo compounds include 2-phenylazo-2,4-dimethyl-4methoxyvaleronitrile, 2-cyano-2-propylazoflumamide, 1-1 '-Azobis-cyclohexanone-1-
Carbonitrile, 2,2'-azobisisobutyronitrile, 2,2'azobis(2,4dimethylvallonitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2・2′−
Azobis(2-amidinopropane) hydrochloride, azobisisobutyronitrile, benzenediazonium chloride, etc., and azide compounds such as 2,6-dichloro-4-nitro-azidobenzene, azidophenylamine, 3,3 '-Dimethoxy-4,4'-diazidodiphenyl, 4'-methoxy-4-azidodiphenylamine, 4,4'-diazidophenylamine, 4,4'-diazidophenylmethane, 4' -Nitrophenyl azobenzene-4-
Azide, 1-azidopyrene, 3,3'-dimethyl-
Possible examples include 4,4'-diazidophenyl, 4,4'-diazidophenyl azonaphthalene, and the like. In addition, carbon tetrachloride, silver bromide, 2-naphthalisulfonide chloride, etc. can be used as the halogen compound.
According to experiments conducted by the inventors, it is particularly desirable to use an azo compound. The paint varnish is optional, but preferably one that dissolves the photofoaming agent used. In particular, as for the above-mentioned azo compounds, aqueous ones such as aqueous acrylic and aqueous vinyl acetate are preferable. The amount of blowing agent added varies depending on the required uneven shape, or if colorants are mixed into the paint, the pigments and dyes used, but generally it is 20 parts by weight or more per 100 parts by weight of varnish. is desirable. Further, if the paint used is colored, it is desirable that the amount added be even higher. The step of applying the surface resin layer is preferably performed before foaming by irradiating light as shown in the drawings. The surface resin layer is made of thermoplastic resin such as acrylic resin, vinyl resin, polyolefin resin, phenolic resin, melamine resin, polyester resin,
Thermosetting resins such as polyurethane resins, or photocuring resins made by adding photosensitizers such as benzophenone and benzoin to acrylic resins, epoxy resins, polyester resins, etc. are optional. In some cases, it is required that the coating is not solidified or hardened at the time of light irradiation, except in cases where the amount of coating is extremely small. That is, when a thermoplastic resin or a thermosetting resin is used, it is desirable to solidify or harden the paint in a post-process after light irradiation (foaming). When a photocurable resin is used, it is desirable to cure it simultaneously with foaming by irradiating it with light, or to partially cure it during foaming and then irradiate it with light again in a subsequent step to completely cure it. Of course, when using a photocurable resin, the foaming agent must be decomposed before the resin hardens, so the amount of photosensitizer added to the resin must be below a certain amount. It won't happen. Note that the use of a photocurable resin is particularly advantageous since foaming and curing can be performed simultaneously in the same process. If a surface resin layer is applied after foaming, a very good unevenness effect cannot be expected because the surface resin layer is not present at the time of foaming, and the gas decomposed by the foaming agent on the surface of the foamed paint will diffuse into the atmosphere. There are the following methods for selectively irradiating light. As shown in FIG. 2, a pattern is formed on a paint containing a photofoaming agent using a light-transmitting ink and a light-shielding ink. The light-shielding property and the light-shielding property are not particularly limited in terms of material, as long as there is a certain difference in light transmittance between each ink. To give an example, the ink used for the translucent part is preferably one using a coloring agent such as an organic transparent pigment or dye. Of course, the parts without pictures,
Areas without colorants are also considered to be in the category of translucent ink. In addition, the ink used for the light-shielding portion is preferably an inorganic pigment or an organic pigment with a high concentration. Also, if you want the light-colored or transparent part to be a light-shielding part (non-foaming part),
It is effective to add a benzophenone-based or benzotriazole-based ultraviolet absorber or a fluorescent brightener having ultraviolet absorption ability. A pattern is printed on a transparent film using translucent ink and light-shielding ink, and it is placed on top coat resin and irradiated with light to decompose and foam the foaming agent in the translucent part, and at the same time or Thereafter, the top coat resin is cured and the ink is transferred to the top coat resin surface. In this case, since the film is cured with the film still on, the top coat resin is limited to a solvent-free type resin. Also, since this method exposes the ink layer, it is desirable to further apply a top coat depending on the intended use. A pattern (ordinary ink) is applied to the base material, a negative film or a positive film that matches the pattern is prepared in advance, and it is layered on the top coat resin in synchronization with the pattern, and the entire surface is irradiated with light. (Mask method) However, with this method, registration is troublesome. The irradiation equipment used to decompose the photofoaming agent and harden the resin includes a polymerization fluorescent lamp with an output of 1 W/cm, outputs of 30 W/cm, 60 W/cm, 80 W/cm,
High-pressure mercury lamps such as 160W/cm are optional. Any method such as gravure coating, roll coating, flow coating, spray coating, etc. can be used to apply a paint containing a photofoaming agent to the entire surface of the substrate and to provide a surface resin layer on the entire surface. The tone embossed decorative sheet or tone embossed decorative board produced by the method of the present invention can be used as a ceiling material,
Its uses are wide-ranging, including flooring materials, other interior materials, furniture materials, cabinet materials, and housing equipment. The present invention, which has the above-described configuration, can extremely efficiently create a concave-convex pattern that matches the pattern. There is no need to use expensive embossing rolls. Base materials without heat resistance can be used. When using UV-curable paint, foaming and curing of the paint can occur at the same time, which simplifies the work process. Since unstable substances such as hardening inhibitors are not used, a stable embossing effect can be obtained. It has the following effects. Next, examples of the present invention will be shown. Example 1 A 23 g/m ² unbleached tissue paper was subjected to a sealer treatment with an acrylic paint, and then a wood grain pattern was created using a gravure printing machine under the following conditions.

[Table] Ink prescription Nitrocellulose ink (panel color, manufactured by Toyo Ink Manufacturing Co., Ltd.) using an organic pigment as a colorant 4th color: Conduit plate, plate depth 40μ, 150/in, light-shielding ink prescription Nitrocellulose Ink (panel color above)
100 parts by weight fluorescent whitening agent (Uvitex-OB, manufactured by Ciba Geigy Corporation)
5 〃 Total 105 〃 Acrylic urethane resin (solid content 30
%) by gravure coating, approx. 10g/m ²
(Wet). When the above paint was irradiated with ultraviolet light using a high-pressure mercury lamp with an output of 80 W/cm at a irradiation distance of 15 cm and a feed rate of 1 m/min before curing, the area other than the conduit foamed and became convex, and the conduit became concave. I got a matching embossed decorative sheet. However, in the convex portions, the light was somewhat blocked by the ink, and the sharpness of the pattern was reduced. Note that in this formulation, the acrylic urethane paint requires curing in a post-process. Example 2 A top coat resin having the following formulation was applied to the printed matter of Example 1 by roll coating at a coating amount of 15 g/m ² . Paint formulation oligoacrylate (Aronix 8060, manufactured by Toagosei Kagaku) 100 parts by weight β-hydroxyethyl acrylate 20 Neopentyl glycol diacrylate 20 Penzoin ethyl ether 3 Total 143 After that, the same irradiation conditions as in Example 1 were applied. When irradiation with ultraviolet rays was carried out, a synchronous embossed decorative sheet similar to that of Example 1 was obtained. (This formulation does not require curing in the post-process.) Example 3 80g/ ^m2 titanium paper was laminated to 5.5m/m thick lauan plywood, sealed with an acrylic urethane sealer, and then the following formulation was applied. The entire surface was coated with a photofoamable paint consisting of the following using a roll coater. Paint formulation Water-based acrylic varnish (solid content 40%) 100 parts by weight Photofoaming agent [1,1'-azobis-cyclohexane-1-carbonitrile] 60 〃Surfactant 0.5 parts by weight Total 160.5 〃 The above coated material is used as a base material Approximately 300% of polyester resin consisting of the following formulation is made using the vinylon film method.
g/m ² was applied. Unsaturated polyester resin [Polylite KC-34
Nippon Reichhold Co., Ltd. 100 parts by weight 55% methyl ethyl ketone peroxide 0.5 Total 100.5 Before curing the above polyester, a photographic film with a pattern made of transparent parts and light shielding parts was fixed on vinylon film, As a result of irradiation distance of approximately 15 cm using a high-pressure mercury lamp with an output of 80 W/cm, and a belt conveyor running at a speed of 10 m/min 10 times, the polyester resin corresponding to the pattern on the film in the transparent part decomposed the photofoaming agent. It became a convex part. Thereafter, the polyester resin was left to stand at room temperature to completely cure, and then the vinylon film was peeled off to obtain an embossed polyester decorative board. Example 4 A polyester resin having the same formulation as in Example 3 was used on a substrate coated with the same photofoaming paint as in Example 3, and a vinylon film was coated in advance to make a decorative board by the film method. A similar pattern was created using the translucent ink and light-shielding ink described in 1, the films were stacked so that the printed surface was in contact with the polyester resin, and the film was irradiated with ultraviolet rays under the same irradiation conditions as in Example 3. After curing at room temperature. When the vinylon film was peeled off, a synchronously embossed wood-grain polyester decorative board was obtained in which the pattern was transferred and the conduit portions were concave portions and other convex portions. In this example, the sharpness of the pattern was maintained even in the convex portions.

[Brief explanation of the drawing]

Figure 1 shows the state in which the photofoaming paint is applied to the entire surface of the substrate, Figure 2 shows the state in which a pattern is formed using translucent ink and light-shielding ink, and Figure 3 shows the state in which a surface resin layer is provided. FIG. 4 is a cross-sectional view of each of the structures in which a concave-convex pattern is formed by irradiating light. Further, FIG. 5 is an example of an embodiment using the mask method, and is a sectional view of a state in which a surface resin layer is further provided on the transferred ink. 1...Base material, 2...Paint containing a photofoaming agent,
2'... Foaming coating film, 3... Transparent ink, 4...
...Light-shielding ink, 5...Surface resin layer, 6...Surface resin layer.

Claims (1)

[Scope of Claims] 1. A paint containing a photofoaming agent is applied to the entire surface of a base material, a pattern is formed on the base material using a translucent ink and a light-shielding ink, and a surface resin layer is further provided on top of that. By irradiating the surface resin layer with light before it solidifies or hardens, only the photofoaming agent on the lower side of the translucent ink is decomposed, and the surface resin layer above the decomposed part is raised. A method for creating an uneven pattern characterized by forming a part. 2. The method for creating an uneven pattern according to claim 1, wherein the surface resin layer is an ultraviolet curable resin composition.