JPS614578A - Manufacture of decorative sheet - Google Patents

Abstract

PURPOSE:To obtain the titled decorative sheet having excellent steric properties by coating a composition contg. an N-nitrosohydroxylamine salt and a pigment of metallic oxide, coating an ultraviolet-curing resinous composition thereon, and then irradiating ultraviolet light. CONSTITUTION:A printing ink composition consists of a pigment of metallic oxide or metallic sulfide and an N-nitrosohydroxylamine salt shown by the formula [R is alkyl, aryl, alkylaryl, or arylalkyl, (n) is 1-6, and M is n-valence metal or ammonium]. Said composition is coated on a base material such as paper, resinous sheet, and a wood board. Then coated film-forming components such as polyester (meth)acrylate and polyurethane (meth)acrylate are coated, and ultraviolet light is irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a decorative sheet, and more particularly, to a method for manufacturing a decorative sheet having an uneven surface that is completely in sync with a printed pattern on a base material.

Conventionally, decorative decorative sheets with wood grain or geometric uneven patterns on their surfaces have been widely used as exterior panels for furniture, fittings, or electrical equipment, but these sheets are often manufactured by embossing. has been done. but,
According to such a mechanical method, it is difficult to form an uneven pattern that closely matches the pattern of the sheet, and there is also the problem that a large number of large-scale equipment is required, which increases manufacturing costs.

In order to solve such problems, for example,
No. 9-122553 discloses that a desired printing pattern is formed on a substrate using a printing ink composition containing a so-called curing inhibitor such as an ultraviolet absorber or a polymerization inhibitor, and then ultraviolet curing is applied on the printing ink composition. By applying a cured resin composition and irradiating it with ultraviolet rays, depressions are created in the cured resin layer corresponding to the printed pattern, thus forming a three-dimensional uneven surface that is in sync with the printed pattern. A method of manufacturing the sheet has been proposed.

In such conventional methods, as a curing inhibitor,
For example, conventionally known ultraviolet absorbers and polymerization inhibitors such as hensitriazole derivatives and quinones are used, but it is difficult to print on a substrate using a printing ink containing such curing inhibitors. When a pattern is applied and an uneven surface is formed on the cured resin layer as described above, the biggest problem is that the recesses formed corresponding to the printed pattern are still shallow.
It is cited that it lacks three-dimensionality.

Also, in natural precious woods, the conduit part of the tissue generally has less luster or luster than other parts. □7 Ioyui, □III fl'i-**'
When a conduit portion as a pattern is printed on a base material using printing ink as shown in 8□, and a recess is formed in the cured resin layer corresponding to the printed pattern as described above, this recess is There is also the problem that it becomes noticeably more glossy or glossy than the other parts, giving a very unnatural impression as a decorative sheet with a wood grain pattern.

The present invention has been made in order to solve the above-mentioned problems, and the present invention has been made to completely synchronize with the printed pattern on the base material, and to form a deep concave portion corresponding to the printed pattern so as to be three-dimensionally hollow.
A further object of the present invention is to provide a method for manufacturing a decorative sheet in which the recesses have substantially no luster or luster.

The method for producing a decorative sheet according to the present invention is based on the following formula: Also, 7th grade and 7th grade are shown.
N-nitrosohydroxylamine salt represented by e,
A printing pattern is applied to a base material using a printing ink composition containing a metal oxide pigment or a metal sulfide pigment, and an ultraviolet curable resin composition is applied onto this base material, and then an ultraviolet curable resin composition is applied to this base material. The method is characterized by irradiating ultraviolet rays to form concave portions in the cured resin layer that match the printed pattern.

In the method of the present invention, the base material is not particularly limited, and for example, paper, resin sheets, wood boards, plywood, metal plates, etc. are used. Examples of the resin sheet include polyvinyl chloride resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyvinyl acetate, saturated polyester,
A sheet made of a resin such as polyvinylidene chloride, acrylic resin, or thermoplastic polyurethane resin is preferably used.

Such a resin sheet may contain various additives required depending on the resin, such as a plasticizer, a filler, a coloring agent, an antioxidant, and the like.

The printing ink used in the method of the present invention has a curing inhibitor of the general formula
Indicates a valent metal or ammonium. ) represented by N-
Contains a metal oxide pigment or metal sulfide pigment along with a nitrosohydroxylamine salt.

In the above N-nitrosohydroxylamine salt, R is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-phthyl, tertiary-butyl,
Amyl, neopentyl, isoamyl, hexyl, isohexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, decyl, isodecyl, lauryl, tridecyl, mixed alkyl of CI2 to CI5, stearyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 4-methyl Alkyl groups and cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl and naphthyl groups, arylalkyl groups such as benzyl, β-phenylethyl, T-phenylpropyl, β-phenylpropyl,
tolyl, xylyl, ethylphenyl, butylphenyl,
Examples include alkylaryl groups such as tertiary butylphenyl, octylphenyl, isooctylphenyl, tertiary octylphenyl, and nonylphenyl.

Examples of M include alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, metals such as aluminum and cerium, and ammonium.

The N-nitrosohydroxylamine salt is contained in the printing ink in an amount of 1 to 10% by weight, preferably 3 to 8% by weight.

If the content of this N-nitrosohydroxylamine salt is less than 1% by weight based on the printing ink, an ultraviolet curable resin composition layer applied on the printed pattern by this printing ink, c: *9+vAt- l
Ia″L f, Knee, != Q &: , IgdE
IIH14jj$*4°''6 It is poor in the effect of suppressing the curing of the resin composition layer, and therefore it is difficult to form deep recesses in the cured resin layer in synchronization with the printed pattern.On the other hand, when the content is 10 When the amount is greater than % by weight, diffusion from the printed pattern containing it into the ultraviolet curable resin composition layer above it becomes excessive, and a wide concave portion is formed corresponding to the printed pattern, resulting in a decrease in resolution. Therefore, it is not desirable.

According to the method of the present invention, since the printing ink contains a metal oxide pigment or a metal sulfide pigment as described below together with the above-mentioned N-nitrosohydroxylamine salt as a curing inhibitor, their synergistic effect causes Not only when N-nitrosohydroxylamine salt is used alone, but also when compared to printing inks that use conventionally known curing inhibitors, the cured resin layer is more responsive to the printed pattern produced by the printing ink. A much deeper recess can be formed.

Examples of such metal oxide pigments or metal sulfide pigments include zinc white (zinc oxide) and cadmium red (cadmium sulfide and cadmium selenide).
(solid solid with ammonium), yellow lead (lead chromate), iron oxide, titanium oxide, etc. These pigments are usually contained in printing ink in an amount of 5 to 30% by weight, depending on the type thereof. In addition, in order to give the desired hue to the printed pattern,
Alternatively, as an extender pigment, an appropriate amount of a non-oxide or non-sulfide inorganic pigment, a metal powder pigment, or an organic pigment can be blended in the printing ink together with these metal oxide pigments or metal sulfide pigments. Examples of such pigments include carbon black, copper phthalocyanine blue, azo pigments, aluminum powder, barium sulfate, and the like.

The printing ink used in the method of the present invention has a normal composition except that it contains the curing inhibitor and the oxide pigment or sulfide pigment as the pigment, for example, resin 10-1
5% by weight and 60-80% by weight of organic solvent.

According to the method of the present invention, after a desired printing pattern is printed on a substrate using such a printing ink, an ultraviolet curable resin composition is applied thereon.

The ultraviolet curable resin composition that can be preferably 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 a resin composition that contains dyes, pigments, fillers, etc., and is usually crosslinked and cured within a few seconds when exposed to ultraviolet rays. High molecular weight polymers, oligomers, monomers, etc. having an acryloyl group, a methacryloyl group, or other addition-polymerizable double bonds in the molecule are usually used as the film-forming component. In the present invention, polyester (meth)acrylate, polyurethane (meth)acrylate, epoxy (methacrylate), etc. are preferably used as such coating film-forming components.

The reactive diluent is blended to reduce the viscosity of the film-forming component to make it coatable, and to crosslink and network the film-forming component when exposed to ultraviolet rays. , a polyfunctional oligomer or monomer. However, it can also be used by itself as a film-forming component. In the present invention, monomers having two or more acrylate groups and/or methacrylate groups in the molecule are preferably used as such reactive diluents, and specific examples thereof include trimethylolpropane tri(meth)acrylate, Examples include pentaerythritol tri(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanethiol di(meth)acrylate, and diethylene glycol di(meth)acrylate. Furthermore, 2-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, hensyl, hensifhenone, henzine ether, chlorothioxanthone, jetoxyacetophenone, benzyl dimethyl ketal, etc. are usually used.

The amount of each component in the ultraviolet curable resin composition as described above is usually about 20 to 90% by weight of the film-forming component.
, preferably from 40 to 70% by weight, with about 10% reactive diluent
The amount is 80% by weight, preferably 30% to 60% by weight, the photopolymerization initiator is about 0.5% to 10% by weight, and the above-mentioned components are further added as necessary.

In the method of the present invention, UV-curable unsaturated polyester resin compositions can also be preferably used. This resin composition usually contains unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid or their anhydrides, and if necessary, fucuric anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and succinic acid. A dibasic acid component consisting of a saturated dibasic acid such as , adipic acid, and sepatic acid, and ethylene glycol, propylene glycol, butylene glycol, glycerin, diethylene glycol, triethylene glycol, neopentyl glycol, pentaerythritol, trimethylolpropane, etc. A reaction product with a polyhydric alcohol is used as a film-forming component. A photosensitizing agent and higher fatty acids such as tung oil, linseed oil, dehydrated mustard oil, and soybean oil, polymerizable monomers, other fillers, pigments, etc. are blended into this to make it UV curable. A resin composition is formed. It is also possible to use urethane-modified polyester resins in which unsaturated polyester is partially substituted with tolylene diisocyanate, methylene diisocyanate, etc., or epoxy-modified resins.

Next, according to the present invention, this ultraviolet curable resin composition layer on the base material is irradiated with ultraviolet rays to form deep recesses in the cured resin layer corresponding to the printed pattern.

The ultraviolet rays may be irradiated by any conventional method known in the art, for example, by using an ultraviolet source such as a xenon lamp, a low pressure, medium pressure, high pressure, or ultra-high pressure mercury lamp. The ultraviolet rays may be irradiated in an amount sufficient to sufficiently cure the ultraviolet curable resin composition, and are appropriately selected depending on the composition.
/cm mercury lamp, irradiation may be performed for 1 second to several seconds.

FIG. 1 shows a cross-sectional view of a main part of a base material 1 before irradiation with ultraviolet rays in the method of the present invention, and the required printing is performed on this base material with a printing ink containing the curing inhibitor and pigment. A pattern 2 is applied, and a resin layer 3 made of the ultraviolet curable resin composition is further formed thereon. In such a resin layer, the mechanism is not necessarily clear;
Further, although the present invention is not limited by any theory, as shown in the figure, the curing inhibitor 4 included in the printed pattern 2
is diffused to the surface side of the resin layer 3 along the printed pattern, and is included in the resin layer along the printed pattern. As a result,
By irradiating such a resin layer with ultraviolet rays, the second
As shown in the figure, the part 5 of the resin layer that follows the printed pattern
crosslinking is delayed, but the other portions 6 are quickly crosslinked.

That is, the resin layer that does not correspond to the printed pattern is quickly cured by ultraviolet irradiation and becomes three-dimensional, but the portion 5 of the resin layer in which the curing inhibitor has been diffused is delayed in curing and forms the recess 7, thus preventing the printing. A cured resin layer 8 is formed having an uneven surface that perfectly matches the pattern.

Furthermore, the recesses thus formed are less shiny or shiny than other parts.

As described above, according to the method of the present invention, a printing pattern is applied to a substrate using a printing ink containing a metal oxide pigment or a metal sulfide pigment together with the above-mentioned curing inhibitor N-nitrosohydroxylamine salt. , an ultraviolet curable resin composition is applied on top of this, and then ultraviolet rays are irradiated on it, so
Although the reason is not necessarily clear, due to the synergistic effect of the above curing inhibitor and the metal oxide pigment or metal sulfide pigment, the curing of the resin layer corresponding to the printed pattern is significantly delayed, and as a result, N-nitrosohydroxyl Not only compared to the case where an amine salt is used alone, but also compared to printing inks using conventionally known effect inhibitors, deeper recesses are formed in the resin layer corresponding to the printed pattern than ever before,
In this way, the uneven pattern formed is completely in sync with the printed pattern and has excellent three-dimensionality.

Moreover, this recess has substantially no luster or luster, and for example, if a conduit part in a wood grain pattern is formed into a recess like this,
When made into parts, it has a natural three-dimensionality comparable to that of natural precious wood. Furthermore, since the printed pattern is covered with a cross-linked and cured resin layer, it has excellent heat resistance, abrasion resistance,
It has desirable properties as a decorative sheet, such as strength.

The method for producing a decorative sheet according to the present invention will be described below with reference to Examples.

Example 1 A vinyl chloride resin sheet with a thickness of 0.1 mm containing 20 parts by weight of plasticizer per 100 parts by weight of resin was used as the base material, solid printing was performed on this with ordinary gravure ink, and then wood grain was printed. After printing the pattern, a pattern representing the conduit portion was printed using a printing ink containing the pigment and hardening inhibitor shown in the table. An ultraviolet curable resin composition containing trimethylolpropane trimethacrylate as a film-forming component was applied onto this printed pattern to a thickness of 20 μm. Next, this resin layer was irradiated with ultraviolet rays for 1 second using a mercury lamp with an output of 80 W/cm to harden the resin layer and form an uneven surface.

Yo, □. 11, 7□wa. The resin layer was cured in the same manner as above, except that a printing ink containing □ or □□j611 oxide pigment or sulfide pigment, or a printing ink containing non-oxide pigment or non-sulfide pigment was used. .

The depth of the recesses on each of the uneven surfaces formed as described above, that is, the degree of rotation, was measured using a contracer, and the curls or gloss of the recesses were visually observed. The results are shown in the table. In the gloss evaluation in the table, ◯ indicates that the recessed portion is less glossy than other parts, and × indicates that it is more glossy than other parts.

As is clear from the table, according to the method of the present invention, deep recesses are formed corresponding to the printed pattern, and these recesses do not have lint or gloss.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts showing the base material, the printed pattern thereon, and the ultraviolet curable resin composition layer, and FIG. 2 is a cross-sectional view of the main part showing the base material, the printed pattern thereon, and the ultraviolet curable resin composition layer. FIG. FIG. 3 is a sectional view of a main part of the formed decorative sheet. ■... Base material, 2... Printed pattern, 3... Ultraviolet curable resin composition layer, 4... Curing inhibitor, 7... Concave portion,
8... Cured resin layer.

Claims (2)

[Claims] (1) (a) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R is an alkyl group, aryl group, alkylaryl group, or arylalkyl group, n is a number from 1 to 6, M is n
Indicates a valent metal or ammonium. ) A printing pattern is applied to a substrate with a printing ink composition containing an N-nitrosohydroxylamine salt represented by (b) a metal oxide pigment or a metal sulfide pigment, and the substrate is subjected to ultraviolet curing. 1. A method for producing a decorative sheet, which comprises applying a cured resin composition and then irradiating the cured resin composition with ultraviolet rays to form concave portions in the cured resin layer that match the printed pattern. (2) The method for producing a decorative sheet according to claim 1, wherein the N-nitrosohydroxylamine salt is an N-nitrosophenylhydroxylamine aluminum salt.