JPS6021857B2 - Method for creating uneven patterns on sheet surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an uneven pattern on the surface of a sheet, and more particularly, it relates to a method for forming an uneven pattern on the surface of a sheet for imparting an uneven pattern that is completely synchronized with a printed pattern on the surface of the sheet. .

Synthetic resin decorative sheets with woodgrain or geometric uneven patterns are pasted on the surfaces of fixtures, furniture, fittings, or interior wallboards to improve their appearance and appearance.

Conventionally, two methods of manufacturing the above-mentioned uneven patterned sheet have been explored: mechanical means and chemical means, but in the case of the former, a lot of equipment such as emboss rolls and colored print rolls is required, and the incidental equipment is expensive. On the other hand, in the case of the latter chemical means, the desired uneven pattern is obtained by foaming or shrinking the sheet base material, so it is necessary to make the above reaction occur sufficiently. It has the disadvantage that it is very difficult to control and it is difficult to obtain uniform quality and appearance. In addition, since the printed pattern layer on the surface is directly exposed to the surface, the method of depositing and shifting has the drawback that the pattern may disappear due to solvent or the pattern may become unclear due to wear, so additional protection is required to protect the printed pattern layer. It was necessary to create layers.

In view of the above-mentioned drawbacks, this invention was made by the present inventors in order to obtain a method that can easily form an uneven pattern by chemical means that does not require large-scale equipment. The surface of the crosslinkable synthetic resin sheet is masked to prevent the transmission of ultraviolet rays, and this is irradiated with ultraviolet rays to cause a crosslinking reaction in the unmasked areas, dividing the sheet base material into crosslinked and non-crosslinked areas.
It was discovered that when a thermoplastic synthetic resin sheet is laminated to the masked surface of the sheet and then heated and stretched, depression development occurs in the masked area, and based on this finding, the present invention was made.

That is, first of all, the gist of the present invention is to print a pattern of a desired shape on the surface of a synthetic resin sheet that can be crosslinked by ultraviolet rays using ink that does not transmit ultraviolet rays, and then to irradiate ultraviolet rays from the surface and then print the pattern on the surface side. This is a method for forming an uneven pattern on the surface of a sheet, which is characterized by laminating a colored layer of a desired color and then heating and stretching, and the second invention is a method of forming a pattern on the surface of a synthetic resin base sheet that can be crosslinked by ultraviolet rays, and does not allow ultraviolet rays to pass through. A pattern of a desired shape is printed using ink, and a synthetic resin sheet that can be cross-linked with ultraviolet light is further layered on the surface of this base sheet.
This is a method for forming an uneven pattern on the surface of a sheet, which is characterized by irradiating the surface with ultraviolet rays and then heating and stretching.

The compositions of the ultraviolet crosslinkable synthetic resin base sheet and the ultraviolet crosslinkable synthetic resin sheet in the first and second inventions include: - vinyl chloride resin, - photoreactive plasticizer, - general plasticizer, and - light. It consists of a sensitizer, ■thermal polymerization inhibitor, ■stabilizer, ■pigment, and other additives.

■ Vinyl chloride resins include pinyl chloride homopolymer, vinyl chloride and vinyl acetate, acrylonitrile, styrene, (meth)acrylic acid ester, ethylene,
It refers to a copolymer of one or more types of propylene, butylene, etc. alone or as a mixture, and other polymers compatible with the vinyl chloride resin may also be mixed.

(2) Examples of photoreactive plasticizers include oligomers that act as plasticizers before irradiation with ultraviolet rays and are crosslinked by irradiation with ultraviolet rays, and oligoester acrylates as oligomers that act as monomers.

Monomers include ■ esters of polyhydric alcohol and acrylic acid, and ■ esters of polyhydric alcohol and methacrylic acid. Acrylate, tetramethylolmethanetetraacrylate, diventaerythritolbentaacrylate, etc. are used, ■ As esters of polyvalent alcohol and methacrylic acid, 1,6 hexanediol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate , diventaerythritol bentamethacrylate, etc. are used.

In addition, those that are compatible with vinyl chloride and have at least two or more polymerizable unsaturated groups in the molecule are used.

These ultraviolet crosslinkable photoreactive plasticizers may be used alone or in combination.

■ General plasticizers include phthalate ester plasticizers such as di-2-ethylhexyl phthalate, di-normal octyl phthalate, dihexyl phthalate, diisodecyl phthalate, phosphate ester plasticizers, polyester plasticizers, trimetate ester plasticizers, etc. Epoxidized soybean oil or the like is used.

■ As photosensitizers, photoreactive plasticizers are used for the purpose of promoting reactions caused by ultraviolet rays, and include penzoin alkyl ethers and pendyls such as benzoin methylether, benzoin isopropyl ether, and penzophenone. , and other commonly used photosensitizers.

■ Thermal polymerization inhibitors are used to prevent photoreactive plasticizers from crosslinking due to heat during molding, such as picric acid, phenol, hydroquinone, hydroquinone monomethyl ether, penzoquinone, phenothiazine, methyl/hydroquinone, etc. Commonly used thermal polymerization inhibitors are used. (2) As stabilizers, commonly used metal soaps, tin compounds, phosphate esters, epoxy compounds, antioxidants, etc. are used as necessary.

■ As the pigment, any commonly used pigment for vinyl chloride resin may be used. The amount of the above UV-crosslinkable synthetic resin composition to be added is 5 to 6 parts by weight of a photoreactive plasticizer and 0 to 12 parts by weight of a general plasticizer to 100 parts by weight of the base material such as vinyl chloride resin. A photosensitizer is added in an amount of 1 to 5 parts by weight based on the photoreactive plasticizer, a thermal polymerization inhibitor and a stabilizer are added thereto, and a pigment is added if necessary. Inks that do not transmit ultraviolet rays include those that make the paint film opaque, such as dark pigments such as carbon black, fillers such as calcium carbonate, titanium white, and clay;
Or benzophenone type, benzotriazole type,
An ink containing a salicylate-based ultraviolet absorber is used.

Next, the process of this invention will be explained with reference to the drawings.

FIG. 1 is a conceptual diagram showing the process of the first invention.

When a woodgrain pattern, for example, is printed on the ultraviolet crosslinkable base sheet 1 using ink 2 that does not transmit ultraviolet rays and irradiated with ultraviolet rays 3, a crosslinking reaction occurs on the sheet 1 other than the printed portion ①, and a diagonal line appears in the figure. The portion indicated by is cured, while the printed portion that does not undergo a crosslinking reaction does not undergo curing development.

Next, a colored layer 4 of a desired color is provided on the surface of this sheet,
Thereafter, stretching (arrow P) is performed under heating.

By applying heating and stretching, the portions where no hardening phenomenon has occurred are more easily softened than other portions, so that an uneven pattern 2' in which the printed portions are depressed is formed on the opposite side of the printed portions 2. .

The amount of ultraviolet irradiation is set to be the amount necessary to cause the base sheet material 1 to undergo a sufficient crosslinking reaction, and is appropriately adjusted depending on the sheet composition.

Further, as the heating stretching conditions, the sheet temperature and time (which differ depending on the sheet composition and structure) are selected so that the difference in hardness between the crosslinked part and the non-crosslinked part becomes large, and the stretching is arbitrarily selected depending on the required degree of depression. In the above description, the ultraviolet crosslinkable sheet is preferably colorless and transparent, but if necessary, it may be a sheet colored by adding a pigment to an extent that does not inhibit crosslinking by ultraviolet light.

In the above description, the colored layer 4 laminated on the base sheet 1 after crosslinking with ultraviolet rays may be a printed colored layer, or may be constructed by laminating colored synthetic resin sheets.

In addition, in the steps in the above explanation, as shown in FIG.
After forming a crosslinked portion and a non-crosslinked portion by applying ultraviolet ray irradiation and providing a colored layer 4, various coating layers or a laminate layer 5 may be provided on the back side of the base sheet 1, and heating stretching may be performed. .

In addition, in the above explanation, when crosslinking the base sheet 1 with ultraviolet rays, if the amount of irradiation may not be sufficient for the part on the opposite side of the irradiation (the part indicated by S in the figure), after heating and stretching, the back side of the base sheet 1 The unreacted plasticizer may be crosslinked by irradiating it with ultraviolet rays again.

FIG. 3 is a conceptual diagram showing the process of the second invention.

For example, a wood grain pattern 2 is printed on the surface of the ultraviolet ray crosslinkable synthetic resin base sheet 1 using an ink 2 that does not transmit ultraviolet rays, and a UV ray crosslinkable synthetic resin sheet IA is further laminated on the wood grain printed surface side. Then, when ultraviolet 3 is irradiated from the front side, the entire surface of the laminated ultraviolet crosslinkable synthetic resin sheet IA on the front side and the UV crosslinkable synthetic resin sheet 1 with wood grain printing 2 other than the printed part are removed. The portion (shaded portion in the figure) is crosslinked and cured. Next, when this sheet is stretched under heating as shown by arrow P, the part corresponding to the printed part is not hardened but is in a softened state, so a depression phenomenon occurs due to the stretching, and the laminated ultraviolet cross-linked The synthetic resin sheet layer also forms a sunken uneven pattern.

In the above, the conditions for the amount of ultraviolet irradiation, the addition of pigments in the base sheet 1 and the laminated synthetic resin sheet, etc. are the same as in the first invention.

Incidentally, after applying woodgrain printing 2 to the surface of the UV-crosslinkable synthetic resin base sheet 0 1 and laminating the UV-crosslinkable synthetic resin sheet, the back side of the base sheet is printed as shown in FIG. If the colored layer 4 is provided, the ultraviolet crosslinkable synthetic resin sheet is made transparent or semitransparent, so that it can be made to look no different from a colored sheet in terms of appearance.

As the coloring means, the back surface of the base sheet is colored and printed in a desired color, or separately prepared colored thermoplastic synthetic resin sheets are laminated.

In addition, when performing a coloring treatment, it is desirable to perform it before causing an ultraviolet crosslinking reaction.

This is because after ultraviolet crosslinking, the sheet material changes after the crosslinking reaction, which may impede the adhesion of the printed coating or the thermoplastic synthetic resin sheets to be laminated.

Since this invention is configured as described above, it is possible to easily form a concave-convex pattern in which the printed portion is concave by crosslinking by ultraviolet irradiation and heating stretching, and the depth of the concave pattern portion can be easily formed. The thickness can be easily adjusted by adjusting the composition and thickness of the ultraviolet crosslinkable synthetic resin sheet, as well as by adjusting the amount of ultraviolet irradiation, the heat stretching rate, etc. Furthermore, according to the present invention, since the printed part becomes the bottom of the pattern, the appearance is extremely rich in three-dimensional effect.Moreover, the printed part is completely covered with the cross-linked synthetic resin base sheet, so that an uneven pattern can be obtained. , the printed layer is completely protected, the pattern does not disappear due to solvents, the pattern does not become unclear due to abrasion, and it is possible to easily and inexpensively produce a sheet with an uneven pattern that has a three-dimensional appearance. . Example 1 A UV-crosslinkable sheet having the composition shown in Table A below was rolled and formed by a calendar method, and a wood grain pattern was printed with carbon black on the surface of the base sheet of the obtained fence with a thickness of 0.1, and the main wavelength was 365. UV irradiation was carried out at a rate of 1.5 W/arc and 5.0 W/min.

After that, a 0.1 side polyvinyl chloride sheet with the composition shown in Table B below was laminated on the printed surface to form a two-layer structure, and when the sheet temperature was heated to 180:00 and stretched, only the printed part was A sheet with a clearly depressed uneven pattern was obtained. A Table 4 Vinyl chloride resin 10 parts by weight Trimethylolpropane triacrylate (photoreactive plasticizer) Parts by weight di-2-ethylhexyl phthalate (plasticizer) 15 parts by weight Penzoin methyl ether (photosensitizer) ) 3% Hyde to photoreactive plasticizer. Rokinone (thermal polymerization inhibitor) Same as above Stabilizer Required amount B Table: Vinyl chloride resin 10 parts by weight Di-2
Ethylhexyl phthalate (plasticizer) 3 parts by weight 0 Stabilizer Required amount Pigment
When the uneven patterned sheet obtained in the above example was irradiated with ultraviolet rays under the same conditions as above from the ultraviolet crosslinkable sheet side, the surface strength, stain resistance, and heat resistance were further improved.

Example 2 Blend composition during the process of Example 1 The synthetic resin sheet (0.1 Yanagi) shown in Table B was laminated on the printing surface, and at the same time, the pigment was removed from the back side of the base sheet. 18 by laminating a synthetic resin sheet (0.1 rib)
When the film was heated to 0oo and subjected to 10% longitudinal stretching, clear depressions were observed in the printed area.

Example 3 A UV-crosslinkable sheet having the composition shown in Table C below was rolled and molded by a calendar method, and a wood grain pattern was printed on the surface of the obtained base sheet on the 0.1 thickness side using black ink of carbon black. Next, a UV-crosslinkable sheet with the composition shown in the table below was rolled and molded using a calendar method, and the obtained sheet on the 0.05 side was laminated on the surface of the base sheet to form a two-layer structure, and then the surface side More dominant wavelength 365
When the sheet was irradiated with ultraviolet rays at a rate of 120 W/arc and 5 minutes per minute, and then the sheet was heated to 180 qo and stretched, a sheet with a concavo-convex pattern in which the printed portion was clearly depressed was obtained.

C Table Vinyl chloride resin 10 parts by weight Trimethylolproban triacetate (photoreactive plasticizer) Solitary parts di-2-ethylhexyl phthalate (plasticizer) 15 parts by weight Penzoin isopropyl ether (photosensitizer) 2 for photoreactive plasticizers
% Hydroquinone (thermal polymerization inhibitor) 2% relative to photoreactive plasticizer Stabilizer Required amount D Table Vinyl chloride resin 10 parts by weight Trimethylolpropane triacrylate (photoreactive plasticizer) 2 parts by weight di-2 ethylhexyl phthalate (Plasticizer) 2 parts by weight Penzoin isopropyl ether (Photosensitizer) 2% to photoreactive plasticizer Hydroquinone (thermal polymerization inhibitor) 2% to photoreactive plasticizer Stabilizer Required amount example
4 On the back side of the laminate sheet obtained in Example 3 before irradiation with ultraviolet rays, a synthetic resin sheet with a thickness of 0.1 skin formed by a calendar method according to the composition shown in Table E below was laminated to make it crosslinkable with ultraviolet rays. After irradiating ultraviolet rays with a dominant wavelength of 365 from the front side of the synthetic resin base sheet at a speed of 120 W/skin and 5/min, the sheet temperature was increased to 18
When the sheet was heated to 000°C and stretched, a sheet with an uneven pattern in which the printed portion was clearly depressed was obtained.

E Table Vinyl chloride resin 10 parts by weight Di-2 ethylhexyl phthalate (plasticizer) 3 parts by weight Stabilizer Required amount Pigment
Required amount In addition, the above Example 1
- 4, the heating temperature and stretching ratio for obtaining a clear uneven pattern were as shown in the table below.

*Extremely good sinking condition...◎ 〃 Good ・・・○ Slightly depressed state...△ State where it does not cave in at all...×

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing the process of the first invention, Fig. 2 is a conceptual diagram showing the process of another embodiment, Fig. 3 is a conceptual diagram showing the process of the second invention, and Fig. 4 is a conceptual diagram showing the process of the second invention. It is a conceptual diagram showing the process of the example. 1...Synthetic resin base sheet capable of UV crosslinking, IA
...Synthetic resin sheet capable of UV crosslinking, 2...
...Ink that does not transmit ultraviolet rays, 3...
Ultraviolet rays, 4...Colored layer. Na'legs? 73 leg figures? Figure 4

Claims (1)

[Scope of Claims] 1. A pattern of a desired shape is printed on the surface of an ultraviolet crosslinkable synthetic resin base sheet using an ink that does not transmit ultraviolet rays, and then after irradiating ultraviolet rays from the surface, a colored layer of a desired color is laminated on the surface side. A method for forming an uneven pattern on a sheet surface, the method comprising: and then heating and stretching. 2. A method for forming an uneven pattern on a sheet surface according to claim 1, wherein the colored layer of a desired color is a colored layer formed by printing. 3. A method for forming an uneven pattern on a sheet surface according to claim 1, wherein the colored layer of a desired color is a layer made of a synthetic resin sheet. 4 Print a pattern in the desired shape on the surface of the ultraviolet crosslinkable synthetic resin base sheet using ink that does not transmit ultraviolet rays,
A method for forming an uneven pattern on the surface of a sheet, which comprises further laminating a synthetic resin sheet capable of crosslinking with ultraviolet rays on the surface of this base sheet, irradiating the surface with ultraviolet rays, and then heating and stretching the sheet. 5. A method for forming an uneven pattern on the surface of a sheet according to claim 4, which uses a synthetic resin sheet capable of crosslinking with ultraviolet rays and having a colored layer provided on the back surface. 6. A method for forming an uneven pattern on a sheet surface according to claim 5, wherein the colored layer is a printed colored layer. 7. The method for forming an uneven pattern on the surface of a sheet according to claim 5, wherein the colored layer is a layer made of a synthetic resin sheet.