JPH0257768B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a sheet having an uneven pattern that is completely in sync with a printed pattern on the surface. Conventionally, resin decorative sheets with wood grain or geometric uneven patterns on their surfaces have been widely used as exterior panels for furniture, buildings, or electrical equipment, but these sheets are often decorated with embossing. Manufactured. However, with such mechanical methods, it is difficult to create an uneven pattern that closely matches the pattern of the sheet, and there is also the problem that it requires a large number of large equipment, which increases manufacturing costs. be. The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a simple method for manufacturing a resin sheet having a concavo-convex pattern that is completely in sync with a printed pattern. The method for producing a resin sheet according to the present invention is to print a pattern in a desired shape on the surface of a biaxially stretched thermoplastic resin sheet using ultraviolet curable resin ink, irradiate it with ultraviolet rays, and then heat it without stretching. , characterized in that a concavo-convex pattern is formed on the surface of the resin sheet in synchronization with a printed pattern. The present invention will be described below based on drawings showing examples. Figure 1 shows a biaxially stretched resin base sheet 1 before heating.
shows. The base sheet is not particularly limited, but for example, polyvinyl chloride resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyvinyl acetate, saturated polyester, polyvinylidene chloride, acrylic resin, thermoplastic polyurethane resin, etc. can be used. It will be done. The sheet contains various additives required depending on the resin, such as plasticizers, fillers, colorants,
It may also contain antioxidants and others. The stretching rate in such a biaxially stretched sheet is
As described later, when the base sheet is heated,
It is related to the height at which the sheet shrinks in the non-printed area and rises in the printed pattern area, and the higher the stretching ratio, the higher this height is, but it is usually in the range of 5 to 100%, preferably 10 to 40%. Further, it is preferable that the length and width are stretched at substantially the same stretching ratio. Also,
Similarly, the thickness of these stretched sheets is preferably about 0.05 to 1 mm so that the printed portion of the sheet can be effectively raised to form the desired uneven pattern. According to the method of the present invention, a desired pattern is printed with ultraviolet curable resin ink 2 on the surface of such a biaxially stretched resin sheet. The thickness of the printed pattern is selected so that the printed pattern portion of the sheet does not substantially shrink when the printing ink is crosslinked and then heated without stretching. The ultraviolet curable resin ink used in the method of the present invention usually contains a film-forming component, a reactive diluent, and a photopolymerization initiator, and if necessary, a solvent,
It is an ink made of a resin composition that contains dyes, pigments, fillers, etc., and is usually crosslinked and cured within a few seconds when exposed to ultraviolet rays. As the coating pattern-forming component, a high molecular weight polymer, oligomer, monomer, etc. having an acryloyl group, a methacryloyl group, or other addition-polymerizable double bond in the molecule is usually used. In the present invention, polyester (meth)acrylate, urethane (meth)acrylate, epoxy (methacrylate, etc.) are preferably used as the film-forming component.The reactive diluent reduces the viscosity of the film-forming component. It is blended to make the coating film-forming component cross-linked and networked by UV irradiation, and is usually a polyfunctional oligomer or monomer. As the reactive diluent, monomers having two or more acrylate groups and/or methacrylate groups in the molecule are preferably used, and specific examples thereof include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth) ) acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, and the like. -ethylhexyl (meth)
Acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate,
Monofunctional monomers such as N-vinyl-2-pyrrolidone and tetrahydrofurfuryl (meth)acrylate can be used in combination. Further, as the photopolymerization initiator, benzyl, benzophenone, benzoin ether, chlorothioxanthone, diethoxyacetophenone, benzyl dimethyl ketal, etc. are usually used. The blending amount of each component in the above-mentioned ultraviolet curable resin ink is usually about 20% of the film-forming component.
-90% by weight, preferably 40-70% by weight, reactive diluent about 10-80% by weight, preferably 30-60% by weight, photoinitiator about 0.5-10% by weight, optionally The above-mentioned components are further blended. Next, according to the present invention, ultraviolet rays are irradiated from the printed pattern surface of the sheet to crosslink and cure the printed pattern. The method for crosslinking and curing the ink may be any conventionally known method, for example,
UV light sources such as xenon lamps, low pressure, medium pressure, high pressure or extra high pressure mercury lamps may be used. The amount of ultraviolet rays that is sufficient to fully cure the ultraviolet curable resin ink is sufficient, and is selected appropriately depending on the ink.
In the case of an 80W/cm mercury lamp, irradiation can be performed for one to several seconds. After this, when the sheet is heated without stretching, the second
As shown in the figure, in the stretched sheet, only the portion of the sheet that does not have a printed pattern on its surface substantially shrinks, while the portion of the sheet that has a printed pattern on its surface substantially shrinks due to cross-linking and hardening of the ink. It does not shrink, and thus the portion of the sheet with the printed pattern rises from the sheet surface, forming a textured pattern that is perfectly aligned with the printed pattern. The heating temperature of the sheet is usually in the range of 100 to 200°C. In addition to the stretching rate of the stretched sheet described above, this heating temperature can also be used to control the shrinkage of the sheet portion that does not have a printed pattern on its surface and to control the height of the protrusion of the sheet portion that has a printed pattern. can. FIG. 3 shows, in another embodiment of the method of the invention,
The laminated base sheets are shown before heating. That is, 2 with a printed pattern made with ultraviolet curable resin ink 2
After irradiating the surface of the axially stretched resin base sheet 1 with ultraviolet rays in the same manner as described above, another resin sheet, for example, a vinyl chloride resin sheet 3, is laminated on the back surface by a method such as lamination. By heating the sheet without stretching, as shown in FIG. 4, the resin sheet 3 also shrinks at the same time as the base sheet 1 shrinks in the non-printed pattern area, thus completely matching the printed pattern. to form an uneven pattern. When a colored sheet is used as the resin sheet 3, this sheet can be used as a background of a printed pattern. In addition, when the resin sheet 3 is adhered and laminated on the base material sheet 1 by thermal lamination, the base material sheet 1 shrinks in the non-printed pattern portion during this thermal lamination, and the resin sheet 3 also shrinks in the same way. Following this, it shrinks, and thus a laminated sheet having an uneven pattern that matches the printed pattern can be obtained. As described above, according to the method of the present invention, two
A desired pattern is printed on an axially stretched base sheet using ultraviolet curable resin ink, the printed pattern surface is cross-linked and cured by irradiation with ultraviolet rays, and then the base sheet is heated without stretching to form a surface. Only the portion of the sheet that does not have a pattern created by the crosslinked ink is substantially shrunk, while the portion that has a printed pattern on its surface is not substantially shrunk. Obtainable. The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 A resin composition containing 100 parts by weight of vinyl chloride resin with an average degree of polymerization of 1100, 12 parts by weight of a conventional plasticizer, and appropriate amounts of stabilizers and pigments was formed into a sheet with a thickness of 0.075 mm by a calendar method. , this is 30% vertically,
Biaxial stretching was carried out at a transverse stretching ratio of 20% to obtain a sheet with a thickness of 0.05 mm. A wood grain pattern was printed on the surface of this biaxially stretched sheet using ultraviolet curable resin inks A to C having the compositions shown in the table, with a dominant wavelength of 356 mμ and an output of 80 W/cm.
After irradiating the sheet with ultraviolet rays for one second using a mercury lamp, the sheet is heated to 150°C on a drum without stretching and wound up.In this way, no matter which ink is used, the sheet will be in sync with the printed pattern. A sheet with a convex pattern formed thereon could be obtained. Example 2 The printed biaxially stretched sheet obtained in Example 1 was

【table】

[Table] Ultraviolet rays were irradiated as shown. Separately, for 100 parts by weight of vinyl chloride resin with an average degree of polymerization of 1100, a normal plasticizer
A resin composition containing 17 parts by weight and appropriate amounts of a stabilizer and a pigment was formed into a sheet with a thickness of 0.1 mm by a calendar method, and this was placed on the back side of the stretched sheet at a temperature of 0.1 mm.
Heat lamination was carried out at 150° C. to cause the stretched sheet to shrink, and the laminated sheet to follow this shrinkage. In this way, it was also possible to obtain a sheet having a convex pattern in synchronization with the printed pattern portion.

[Brief explanation of drawings]

The drawing shows an embodiment of the method according to the invention, in which the first
The figure is a sectional view of a main part of a biaxially stretched resin base sheet having a pattern printed with ultraviolet curable resin ink on its surface, and FIG. 2 is a main part of a sheet having an uneven pattern according to the present invention obtained from the sheet of FIG. 1. 3 is a sectional view of a biaxially stretched sheet in which colored resin sheets are laminated, for example, and FIG. 4 is a sectional view of a sheet having an uneven pattern according to the present invention obtained from the sheet of FIG. 3. 1... Biaxially stretched resin base sheet, 2... Ultraviolet curable resin ink, 3... Resin sheet.

Claims (1)

[Claims] 1. Print a pattern in the desired shape on the surface of a biaxially stretched thermoplastic resin sheet with ultraviolet curable resin ink, irradiate it with ultraviolet rays, and then heat it without stretching to form a printed pattern on the surface of the resin sheet. A method for producing a resin sheet, characterized by forming a synchronized uneven pattern.