JPS6410272B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a decorative sheet with an uneven surface having a surface coating layer, and more specifically, a pattern is applied to a sheet-like base material using a resin composition that has the property of expanding the interface of a top coat, and then a top coat is applied thereon. The present invention relates to a method for producing a decorative sheet with an uneven surface having a surface coating layer by applying and solidifying the top coat. Conventionally, the method of forming an uneven surface, especially the method of forming an uneven surface sheet corresponding to a pattern, is to apply pressure using a forming plate, forming roll, etc. that has an uneven shape on the surface, or by heat-pressure embossing. A common method is to transfer the surface shape of the mold material onto the sheet, but with such mechanical methods, it is difficult to match the pattern with the unevenness. The so-called burley print method transfers the color to the bottom of the recesses, or the method of forming irregularities on the sheet surface and then applying a pattern only to the convex parts.Furthermore, after forming the irregularities on the sheet surface, a coloring agent is applied, and the convexes are rubbed into the recesses using a wiping roll, etc. at the same time. The so-called wiping method is used to scrape off the colorant from the surface of the product, but the common drawback of these methods is that the ink or colorant is exposed on the product surface, resulting in problems with surface resistance. If a top coat is applied to cover the surface, the surface shape becomes flat and the design effect is impaired. In addition, in order to solve this drawback of the mechanical method and easily obtain an uneven surface that matches the pattern, a group of methods that should be called chemical or physicochemical methods have been proposed. In such a method, a heat or photocurable resin is used as the surface resin, a part of the pattern is formed with ink that has the property of suppressing or accelerating the hardening of the surface resin, and the difference in curing time of the surface resin is A method has been proposed in which concavities and convexities due to differences in film thickness are formed in synchronization with the pattern by utilizing shrinkage. This method is
Surface irregularities that match the pattern can be obtained relatively easily by changing the ink components, but not only the stability of the ink but also the physical properties of the recesses tend to become unstable, and the depth of the irregularities also depends on the shrinkage of the resin. This includes the problem of being shallow due to the fact that As another method, a method has been proposed in which the surface resin on the ink pattern is removed using an ink that has the property of rubbing the surface resin, thereby forming unevenness that is in sync with the pattern. Although this method is relatively easy to obtain unevenness that matches the pattern, it not only lacks reproducibility and stability, but also causes the edges of the repelled portion to bulge or become spherical in cross section, resulting in a sharp design feel. Physically, there is a defect in that the physical properties of this area are poor because there is no surface resin film on the repellent ink. Furthermore, there is a method in which a part of the pattern is printed with an ink that has a different permeability to the surface resin than other parts, and the difference in penetration creates unevenness and a difference in gloss. A number of methods have been proposed, including a method of scraping off the foamed area after foaming, and a method of printing the foamable resin layer with ink that has the effect of suppressing or promoting foaming to obtain an uneven surface depending on the degree of foaming. However, there is a need for a simple method for producing decorative sheets with consistent embossments on uneven surfaces that are stable and have large surface resistance. Ta. The present invention has been made in view of this point, and its purpose is to provide a method for easily and stably manufacturing a decorative sheet that has excellent surface resistance and has unevenness that matches the pattern. That's true. As a result of consideration of interfacial phenomena related to coating film defects, the present inventors discovered the possibility of utilizing a phenomenon that had not been intentionally used to form irregularities in the past, and completed the present invention. The content of the invention will be explained in detail below. FIGS. 1, 2, and 5 are schematic cross-sectional views of the effects achieved by the method of the present invention, and FIGS. 3 and 4 are reference views. FIG. 1 shows a state in which a pattern layer formed using normal ink 2 and interface expansion ink 3 is present on a base sheet 1. Here, the base sheet may be any material as long as it can be printed with inks 2 and 3.
Vinyl chloride, acrylic, ABS, polypropylene,
There are no particular limitations, as long as it is generally sheet-like and compatible with printing and coating processes, such as plastic sheets such as polyethylene and polycarbonate, surface-treated paper, metal sheets, and inorganic sheets. The same applies to ordinary inks, and any ink may be used as long as it has good adhesion to the base sheet and has extremely poor wetting to the top coat resin. The interface expansion ink 3 will be described later. FIG. 2 shows the above-mentioned sheet with a top coat applied, the top coat 4 showing the state applied on the normal ink 2, and the recess 5 showing the state applied on the interface expansion ink 3. There is. By curing from the state shown in Figure 2 using appropriate means such as ultraviolet rays and heat,
A matching embossed decorative sheet is obtained in which the surface of the pattern portion corresponding to ink 3 has a concave portion. moreover,
FIG. 5 is a cross-sectional view of a product in which an ink 3' in which the ink 3 is further provided with an ability to absorb ultraviolet rays is used. The difference from FIG. 2 is that shrinkage wrinkles are formed on the surface of the recess 5' corresponding to the ink 3', and the curing method is limited to the case where ultraviolet rays are used. In Fig. 5, not only the unevenness that matches the pattern, but also a matte effect that further emphasizes the unevenness appears, further enhancing the design effect. As the interface expansion ink in step 3, one containing a component that makes the wetting of the top coat resin poor is used.
Typically, compounds that reduce the interfacial free energy such as silicone and fluorine compounds are used, but any compound that has the effect of reducing the wetting of the top coat resin in the state of the applied ink film 3 is used. good. The mechanism of concave formation in this case is that the top coat resin layer in contact with the ink film 3 moves from the top of the ink film 3 toward the ink film 2 at the interface due to the expansion of the interface, and at the same time, the top coat resin layer contacts the ink film 3. This is considered to be a phenomenon in which the top coat resin layer on the ink film 3 becomes thinner due to movement of the top coat resin layer in the portion. The movement of the top coat due to the movement of the interface is a function of the viscosity of the paint, and it is thought that the higher the viscosity, the thicker the moving layer, but the resistance to movement is also greater, and the relationship between these is not simple in reality. In addition to the viscosity, the film thickness of the paint is also a major factor in the development of the unevenness effect due to this phenomenon, and as the film thickness increases, the effect becomes smaller. According to experiments conducted by the present inventors, the film thickness was 100μ or less, and the paint viscosity was 50μ.
A value of ~2500CP was appropriate, and formation of irregularities was hardly observed outside this range. FIG. 3 is a reference diagram schematically showing this state. FIG. 4 is a reference diagram schematically showing the state of unevenness formed by so-called liquid-repellent ink. When a liquid-repellent ink is used as ink 3, the stable repelling state will be like this, but in this state, ink 3
Not only is the surface resistance particularly problematic in the ink area, but the shape of the convex end is determined mainly by the surface tension and viscosity of the topcoat resin, so the natural sharpness of the edge area is affected. I can't get it. The material forming the resin layer of the top coat is not particularly limited as long as it has a viscosity within the above range, and examples include thermoplastic resins such as vinyl chloride, polypropylene, polyethylene, polycarbonate, and acrylic, unsaturated polyester, acrylic, and diallyl phthalate. Thermosetting resins such as thermosetting resins and photocurable resins are used, but it is preferable to use photocuring type resins such as unsaturated polyester resins and acrylic resins.
The ultraviolet curing method is also suitable for maintaining the uneven shape. It is obvious that in the method shown in FIG. 5, only an ultraviolet curing type top coating resin is used. The ink 3' used in the method shown in FIG. 5 includes known ultraviolet absorbers, organic fluorescent pigments, etc.
It is suitable that the content is about 20%, but it is arbitrary as long as it prevents reflection of ultraviolet rays. However, since the unevenness formation by the method of the present invention is due to the interface expansion effect on the ink 3 or 3', the difference in film thickness of the top coat can be reduced by only the ultraviolet absorber, etc., without relying on the interface expansion effect. Of course, configurations that clearly produce the same effect are excluded from claim 5. As described above, according to the method of the present invention, not only a surface-coated decorative sheet having an uneven surface that stably matches the pattern can be obtained in a simple manner, but also
Due to the presence of the coating layer on the entire surface, the ink layer is not exposed and a product with excellent surface resistance can be obtained. According to the method of the present invention, decorative sheets can be easily produced for use in interior materials, furniture, cabinets, ceiling materials, floor finishing materials, and other areas that require beautiful design and surface resistance. Examples are shown below, but the present invention is not limited to the following examples unless it departs from the spirit of the claims of the present invention. [Example 1] A semi-rigid colored polyvinyl chloride sheet with a thickness of 0.15 m/m was coated with an ordinary vinyl chloride ink containing vinyl chloride, a vinyl acetate binder, a pigment, and a solvent as the main components, and an ink equivalent to the above. Using ink containing 0.2% modified dimethyl silicone, a wood grain pattern is printed in the order of vinyl chloride ink and modified ink, and then polyacrylic ester, acrylic ester monomer, and photosensitizer are printed on top of this. After applying a 10μ thick photocurable resin with a viscosity of 550CP, the main component of which is , it was cured using three high-pressure mercury lamps (80W/cm), and the surface of the ink pattern containing the modified material became a concave part. I got a beautiful wood grain matching embossed decorative sheet. When the cross section of this sheet was observed, it was found that the thickness of the surface resin layer above the vinyl chloride ink was 10 μm, and the thickness of the surface resin layer above the ink containing the modified product was at least 4 μm. In addition, when the surface of the product sheet was rubbed with Ratsuker thinner, 50
No abnormalities were observed during the round trip. [Example 2] A surface-treated polypropylene sheet with a thickness of 0.05 m/m was coated with a normal polypropylene ink containing a polyamide binder, pigment, and solvent as the main components, and 0.3% of the same ink as above. Using an ink containing chlorinated ethylene oligomer and 2-(2'-hydroxy-5'-methyl-phenyl)benzotriazole, a tile joint pattern is printed in the order in which the ink for polypropylene is used first, and then a light intensifier is applied over this. After applying a photocurable unsaturated polyester resin with a viscosity of 850CP containing a sensitizing agent to a thickness of 25μ, it is cured using a high-pressure mercury lamp (80W/cm), and the surface of the ink pattern containing oligomers becomes a concave part.
I obtained a tile-matching embossed decorative sheet that lost its luster. [Example 3] A wood grain pattern was printed on a 0.10 m/m thick semi-rigid colored PVC sheet using an ordinary vinyl chloride ink containing a salt-vinyl acetate binder, pigment, and solvent as the main components, and inks having the following compositions a to e. , and then apply the same photocurable resin as in Example 1 in the same manner as above.
hardened. The results were as shown in Table 1 below. (Note: a and e are reference examples)

[Example 4]

A wood grain pattern was printed on a 0.15 m/m thick semi-rigid colored PVC sheet using the normal ink of Example 1 and the ink C of Example 2, and then photo-cured with compositions A to E in Table 2 below. The adhesive resin was applied and cured in the same manner as in Example 1. The results were as shown in Table 3 below. (Note: A and E are reference examples)

【table】

【table】

[Example 5]

Printing was performed on a 0.15 m/m semi-rigid colored PVC sheet in the same manner as in Example 4, and the viscosity
A top coat resin consisting mainly of 850CP polyacrylic ester, acrylic ester monomer, photosensitizer, and silica gel was applied, and a high-pressure mercury lamp (80W/
cm). The results of the coating thickness of the top coat resin and the surface unevenness are as shown in Table 4 below.

【table】

[Example 6]

Laminate 0.15m/m thick cardboard and 15μ thick aluminum foil, and use the original paper with primer treatment on the aluminum surface to ink containing a vinyl chloride binder, pigment, and solvent as main components, and 0.7% modified dimethyl silicone to it. A wood grain pattern is printed using an ink containing 50% of the wood grain, and then a plastisol with a viscosity of 1200Cp containing PVC, plasticizer, and heat stabilizer as the main components is applied over it.
After coating to a thickness of 0.05 m/m, it was heated at 180°C for 2 minutes. As a result, a decorative sheet having recesses on the surface of the transparent film on the modified dimethyl silicone ink pattern was obtained. [Example 7] On a 0.15 m/m thick semi-rigid colored PVC sheet, the same normal ink as in Example 1 was added, and in addition, 0.3% modified dimethyl silicone and 5% hydroquinone were applied.
Print the wood grain pattern in this order using ink containing
It was applied and cured in the same manner as in Example 1. As a result, the top resin coating film on the ink f formed concave portions, and a tone embossed decorative sheet with reduced gloss was obtained.

[Brief explanation of drawings]

The drawings are sectional views showing an embodiment of the method of the present invention, and FIG. 1 shows a state in which a pattern is provided on a base sheet 1 using normal ink 2 and interface expansion ink 3, and FIG. Figure 3 shows the state in which the amount of top coat applied was so large that no unevenness was observed, Figure 4 shows the state in which liquid-repellent ink was used, and Figure 5 shows the state in which UV-curable top coat was applied. The cases in which they are used are shown below. 1...Base sheet, 2...Normal ink, 3,
3'...Interface expansion ink, 4...Top coating paint, 5,
5'...Concavity.

Claims (1)

[Scope of Claims] 1. A pattern is applied to a sheet-like base material using a resin composition that has the property of expanding the interface of a top coat, and a top coat is applied thereon, and then the top coat is solidified. A method for producing a decorative sheet with an uneven surface having a surface coating layer. 2. Claim 1, characterized in that a resin composition containing 2% or less of silicone and/or fluorine compound in the resin composition is used as the resin composition having the property of expanding the interface of the top coat. A method for producing a decorative sheet with an uneven surface having a surface coating layer. 3.Use an ultraviolet curing paint with a viscosity in the range of 100 to 2500CP as the top coat, and apply a coating thickness of 3 to 2500 CP.
A method for producing a decorative sheet with an uneven surface having a surface coating layer according to claims 1 and 2, characterized in that the surface coating layer has a surface coating layer of between 100 μm. 4. A surface coating layer according to claim 1, characterized in that a resin composition containing a substance that retards the solidification of the top coat is used as the resin composition having the property of expanding the interface of the top coat. A method for manufacturing a decorative sheet with an uneven surface. 5. Irregularities having a surface coating layer according to claim 1, characterized in that a resin composition containing a substance with low ultraviolet reflectivity is used as the resin composition having the property of expanding the interface of the top coat. A method for manufacturing a surface decorative sheet.