JPH04298350A - Manufacture of scratch-resistant decorative sheet having embossed pattern - Google Patents

Abstract

PURPOSE:To obtain a decorative sheet having a sharp embossed pattern and high design effect and excellent in surface scratch resistance and abrasion resistance. CONSTITUTION:An ultraviolet-curable resin layer is provided to the surface of a thermoplastic sheet having good moldability and irradiated with ultraviolet rays to be semicured and an embossed pattern is applied to the surface of the resin layer in this semicured state and, further, said resin layer is irradiated with ultraviolet rays to be perfectly cured.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for producing a decorative sheet with a highly designed uneven pattern, and more specifically, it is used for wallpaper, architectural interior materials such as ceilings, furniture, storage shelves, cabinets, etc. The present invention relates to the above decorative sheet.

0002

BACKGROUND OF THE INVENTION Conventionally, a decorative sheet having an uneven pattern on the surface of a thermoplastic sheet has been used. Since the surface layer of these decorative sheets is a thermoplastic sheet, they have the disadvantage of lacking resistance to scratches, ie, scratch resistance, abrasion resistance, and the like. In order to improve these problems, a thermoplastic sheet is patterned with an uneven pattern, and then an ultraviolet curable resin layer is placed on top of it, and by irradiating it with ultraviolet rays, the surface becomes scratch resistant.
There are also those with improved wear resistance.

0003

[Problem to be solved by the invention] However, with this method, the upper layer of ultraviolet curing resin cannot penetrate deep into the recesses of the uneven pattern, so the uneven pattern of the decorative sheet obtained is inferior in sharpness. .

[0004] Several proposals have been made to improve these drawbacks. For example, on the surface of a thermoplastic sheet,
By providing a UV-curable resin layer containing a polymerization inhibitor that has a slow curing speed, and providing a UV-curable resin layer that has a faster curing speed on the uncoated surface, it is expected that the thickness will change after curing due to the difference in curing speed. There is a so-called chemical embossing method. However, with this method, the parts that harden quickly have scratch resistance and wear resistance, but the parts that harden slowly have scratch resistance,
The abrasion resistance was poor, and the scratch resistance and abrasion resistance of the sheet as a whole were insufficient.

[0005] Accordingly, an object of the present invention is to provide a method for manufacturing a decorative sheet having an uneven pattern, which has excellent scratch resistance and abrasion resistance on the surface, and has a sharp uneven pattern. It is in.

[0006]

[Means for Solving the Problems] In view of the above-mentioned problems, the present inventors have conducted extensive research, and the above-mentioned object of the present invention is to provide an ultraviolet curable resin layer on the surface of a thermoplastic sheet with good moldability. The scratch resistant material has an uneven pattern, characterized in that the resin layer is semi-cured by irradiating with ultraviolet rays to semi-cure the resin layer, and in this state, an uneven pattern is applied to the surface of the resin layer, and then the resin layer is further irradiated with ultraviolet rays to completely cure the resin layer. We have found that this can be achieved by a method for producing a decorative sheet.

[0007] In the present invention, the thermoplastic sheet on which the ultraviolet curable resin layer is provided may be a plain sheet with a pattern printed on its surface, or may be a sheet that has been subjected to a wiping treatment. Furthermore, a sheet with an ultraviolet curable resin layer and semi-cured resin layer is used as a top layer, and a thermoplastic sheet with a pattern printed on it is used as a base layer, and this top layer and base layer are laminated to form an uneven pattern. A doubling method may also be used in which the sheets are pressure-bonded and then the semi-cured ultraviolet curable resin layer is completely cured.

The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic process sectional view of one embodiment of the manufacturing method of the present invention.

In FIG. 1, A is a cross-sectional view of a thermoplastic sheet 1 on which a pattern 2 is printed. However, the pattern does not necessarily have to be applied. The thermoplastic sheet 1 serving as the base material is made of a thermoplastic resin with good moldability, such as cellophane, acetate, polyethylene, polypropylene, polyester, polyvinyl chloride, polystyrene, polycarbonate, polyamide, or the like. The thickness of the thermoplastic sheet is not particularly limited and can be determined as appropriate. The pattern 2 can be applied by various known methods and with various known materials.

B is a thermoplastic sheet 1 with a pattern 2 printed on it.
A cross section of an uncured sheet with an ultraviolet curable resin layer 3a provided thereon is shown. In this case, the resin composition forming the ultraviolet curable resin layer includes photopolymerizable oligomers such as epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyester acrylate, vinyl acrylate, polyene, and silicone, and monofunctional acrylate, polyfunctional acrylate,
Reactive diluent monomers such as vinyl monomers typified by vinyl acetate, polymerization initiators such as benzoin compounds, acetophenone compounds, and thioxanthone compounds, and in some cases amines and quinones that help the initiation reaction of these polymerization initiators. It is possible to use a resin composition mixed with a polymerization initiation auxiliary agent such as a polymerization agent. It is also possible to add thermal polymerization inhibitors, fillers, adhesion promoters, etc. depending on the purpose of use. Generally, commercially available ultraviolet curable resins may be used.

C is a cross section of the sheet irradiated with ultraviolet rays. As the ultraviolet irradiation lamp 4, various conventionally known lamps such as a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, etc. can be used.

[0013] At this time, in order to keep the ultraviolet curing resin semi-cured, it is desirable that the polymerization reaction rate be 96 to 97%. If it is less than 96%, the resin will adhere to the embossing plate in an uncured state and be removed, and if it exceeds 97%, the curing will progress too much and cracks will occur when embossing is performed or the embossing will not be deep enough. Problems such as this may occur. If the relationship between the equipment and resin conditions to be used and the polymerization reaction rate is determined in advance by infrared spectroscopy or the like, the polymerization reaction rate can be estimated based on the ultraviolet irradiation conditions.

D is a semi-cured ultraviolet curable resin layer 3b
This is a state in which a concavo-convex pattern 5 has been applied using an embossing plate 6. Here, the uneven pattern can be arbitrarily selected by changing the pattern of the embossing plate.

E is a semi-cured ultraviolet curable resin layer 3b
The sheet with the uneven pattern 5 is further exposed to an ultraviolet irradiation device 4.
This shows the state in which the ultraviolet curing resin has been completely cured by irradiating ultraviolet rays.

F is a cross section of a scratch-resistant and abrasion-resistant decorative sheet having a final uneven pattern on which a completely cured ultraviolet curable resin layer 3c having an uneven pattern 5 is applied on the surface.

[0017]

[Examples] Specific examples of the present invention are shown below.

Example 1 A wood grain print was applied on a transparent polypropylene sheet with a thickness of 0.08 mm using an acrylic vinyl chloride/vinyl acetate copolymer resin ink, and an ultraviolet curable ink containing epoxy acrylate as the main component was printed on top of the ink. The resin was applied to a thickness of 5 to 30 μm using a flow coater. After that, a high pressure mercury lamp (120
The resin layer is irradiated with ultraviolet rays (w/cm) for 1 to 3 seconds to bring it into a semi-cured state with a polymerization reaction rate of 96%, and the surface of this resin layer is embossed with wood grain conduits that give the impression of wood texture. The resin layer was completely cured by irradiating ultraviolet light (120 w/cm) for 5 to 10 seconds to prepare a decorative sheet with conduit embossing. The obtained decorative sheet is a decorative sheet that has a sharp uneven pattern and is superior in both scratch resistance and abrasion resistance, and satisfies all of these requirements, compared to conventional products made of uncoated vinyl chloride sheets or vinyl chloride sheets with an ultraviolet resin layer. there were.

Example 2 A pattern was printed on a colored vinyl chloride sheet having a thickness of 0.1 mm using an acrylic salt-vinyl acetate ink, and this was used as a base for doubling. Separately, a transparent vinyl chloride sheet with a thickness of 0.1 mm was coated with an ultraviolet curable resin containing urethane acrylate as a main component to a thickness of 5 to 15 μm using a gravure coater. After that, the ultraviolet rays were irradiated for 1 to 3 seconds using a high-pressure mercury lamp (120w/cm) to form the ultraviolet curable resin layer, which had a polymerization reaction rate of 97.
% of the semi-cured state, and this was used as the top layer for doubling. Next, the upper layer and the lower layer are overlapped, and a concave-convex pattern is applied to the UV-curable resin layer using a wood-grained conduit embossing roll.The upper layer and the substrate are pressed together, and then a high-pressure mercury lamp (120W/ cm) 5-1
The UV-curable resin layer was completely cured by irradiation with ultraviolet light for 0 seconds, and a decorative sheet having an uneven pattern of wood grain conduits was created. As in Example 1, the obtained sheet was a decorative sheet with a sharper uneven pattern and more bulk than the conventional product, and was excellent in both scratch resistance and abrasion resistance.

[0020]

According to the manufacturing method of the present invention, a decorative sheet having an uneven pattern, which has excellent scratch resistance and abrasion resistance on the surface, and has a sharp uneven pattern and a high design quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic process flow sectional view of one embodiment of the manufacturing method of the present invention, where A is a cross section of a thermoplastic sheet with a pattern printed on it, and B is a cross section of a thermoplastic sheet with a pattern printed on it. A cross section of an uncured sheet provided with an ultraviolet curable resin layer is shown, C is a cross section of sheet B that has been irradiated with ultraviolet rays, and D is an uneven pattern formed on the semi-cured ultraviolet curable resin layer by an embossing plate. E indicates a state in which a semi-cured UV curable resin layer with an uneven pattern is further irradiated with UV rays by an UV irradiation device to completely cure the UV curable resin; , F is
1 is a cross-section of a scratch- and abrasion-resistant decorative sheet with a final textured pattern on which a fully cured ultraviolet curable resin layer with a textured surface has been applied.

[Main reference number]

1 Thermoplastic sheet 2 Printing pattern layer 3a Uncured ultraviolet curable resin layer 3b Semi-cured ultraviolet curable resin layer 3c Fully cured UV curable resin layer 4 Ultraviolet irradiation device 5 Uneven pattern 6 Emboss roll

Claims (2)

[Claims] [Claim 1] An ultraviolet curable resin layer is provided on the surface of a thermoplastic sheet with good moldability, the resin layer is semi-cured by irradiation with ultraviolet rays, and in this state an uneven pattern is formed on the surface of the resin layer. A method for producing a scratch-resistant decorative sheet having an uneven pattern, which further comprises irradiating the resin layer with ultraviolet rays to completely cure the resin layer. 2. The method according to claim 1, wherein the ultraviolet curable resin layer is semi-cured before the uneven pattern is applied by irradiating the ultraviolet rays until 96 to 97% of the polymerization reaction of the resin composition has progressed. Production method.