EP1902834B1

EP1902834B1 - Decorative material

Info

Publication number: EP1902834B1
Application number: EP07005983A
Authority: EP
Inventors: Hideaki Mori; Kaori Imamichi; Takeshi Nakamura
Original assignee: Toppan Cosmo Inc
Current assignee: Toppan Cosmo Inc
Priority date: 2006-09-22
Filing date: 2007-03-23
Publication date: 2011-05-11
Anticipated expiration: 2027-03-23
Also published as: EP1902834A1; US20080075966A1; JP2008074002A; ATE508864T1

Abstract

A decorative material, which can express uneven irregular shapes due to the differences in the surface gloss state even when the thickness thereof is thin and which is high in productivity and which includes a substrate; an expression region, which is a recess or a salient; a picture pattern on the substrate which corresponds to the expression region; and an ionizing radiation-curable resin layer; wherein the ionizing radiation-curable resin layer is provided in a vicinity of an outline of the picture pattern except immediately above the picture pattern so as to have a stepwise gradation in gloss conditions, and wherein a viscosity of the ionizing radiation-curable resin layer is 0.1 to 1 Pa¢s

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a decorative material to be used for interior and exterior finishing of buildings and architecture, fittings, or surface decorations or the like of furniture. More specifically, the present invention relates to a decorative material which, in the case of a woodgrain pattern for example, expresses uneven irregularities such as vessel parts stereoscopically by differences in surface gloss.
Priority is claimed on Japanese Patent Application No. 2006-257232, filed September 22, 2006 , the content of which is incorporated herein by reference.

Description of the Related Art

When uneven irregular shapes are expressed by decorative materials, which have been used in assembled furniture of a knock down system, building materials of residences, furniture, or the like, instead of actually forming the shapes on the surface of decorative materials, there is a method to visually express the stereoscopic vision of irregularities using an illusion caused by the human eye by mutually differentiating surface gloss conditions among the parts to be expressed as a recess or a salient. According to this method, even when uneven irregular shapes do not actually exist, the parts with relatively high gloss and the parts with relatively low gloss are recognized as a salient and recess respectively by the human eye.
Specifically, the following exemplifies the above method. A synthetic-resin coated layer which is transparent or semitransparent and which has low gloss is formed on the entire printing surface of the substrate where appropriate patterns including recess patterns are printed. Thereafter, on the surface of the synthetic resin layer except the part which corresponds to the recess patterns, a synthetic-resin coated layer which is transparent or semitransparent and which has high gloss is formed. Needless to say, when the relationship between high and low gloss is reversed, it is possible to obtain a decorative material where the relationship between recesses and salients is reversed.
According to this method, only by preparing two kinds of coating materials with different glosses without any need or special agents or the like, it is possible to readily confer a stereoscopic appearance of uneven irregularities to any substrates. Moreover, since coated layers of coatings with different glosses can be formed by conventional printing methods such as the gravure printing method following the formation of picture patterns, special appliances are not required at all while the production efficiency thereof is high and the conformity with the picture pattern is also readily accomplished. In addition, since the thickness of the coated layers is far thinner compared to differences in levels of irregularities to be expressed, not only resin usage can be reduced but also flexibility thereof can be improved and thus, it is possible to readily realize decorative materials which are excellent in processing suitability for folding. Furthermore, since there are no irregularities with a large unevenness on the surface of decorative materials, there is also an advantage of avoiding contaminants to accumulate in recesses.
From the viewpoints of many advantages as such, decorative materials which adopt this method are already used in large quantities. However; the actual situation of the above method is that it is still inferior to the method, which forms actual uneven irregularities, in terms of giving people the impression of high quality. The reason for the above situation can be considered as the follows. According to the embossing method by machinery, for example, uneven irregular shapes of vessels of natural wood or the like can truly be reproduced including the cross-sectional shape thereof. On the other hand, this method using two kinds of coating materials with different glosses can express only two kinds of irregularity levels since the level of surface gloss is of two kinds. Accordingly, there is a problem in that uneven irregular shapes, which have sloping sections where the depth (height) thereof changes continuously, like vessels of natural wood or the like cannot be expressed.
Accordingly, by providing a gloss adjusting layer which expresses uneven irregular shapes, which have sloping sections where the depth (height) thereof changes continuously, a decorative material expressing uneven irregular shapes, which have sloping sections where the depth (height) thereof changes continuously, like vessels of natural wood or the like has been proposed (for example, refer to Patent document 1).
However, when such a gloss adjusting layer is coated at a high speed of 80 m/min or more for example, satisfactory drying is not achieved and blocking may occur at the time of retrieving, which makes the production thereof difficult.
On the other hand, the decorative material, which is provided with a surface-protective layer formed of an ionizing radiation-curable resin, is known (for example, refer to Patent document 2). Since this surface-protective layer is cured by irradiating an electron beam, blocking does not occur even when coating is carried out with relatively high speed. However, in order to avoid the effects of mutual adhesion with the ink layer or shrinkage due to the curing of resin, a certain coating thickness or an intermediate layer is required.
[Patent document 1] Japanese Patent Publication No. 3629964
[Patent document 2] Japanese Patent Publication No. 3756406

SUMMARY OF THE INVENTION

The present invention is made in view of the above circumstances and its object is to provide a decorative material which can express uneven irregular shapes due to the differences in the surface gloss conditions even when the thickness thereof is thin and which is high in productivity.
The present invention adopts the following method in order to solve the above problems.
A first aspect of the decorative material according to the present invention is a decorative material provided with a picture pattern corresponding to an expression region, which is a salient or a recess, on a substrate and characterized in that an ionizing radiation-curable resin layer is provided with a stepwise gradation in gloss conditions in the vicinity of the outline of the picture pattern except immediately above thereof and the viscosity of the ionizing radiation-curable resin layer is 0.1 to 1 Pa·s.
Since this invention is provided with the ionizing radiation-cured resin layer on the surface thereof so as to have a gradation in gloss conditions, it is possible to produce decorative materials expressing uneven irregular shapes where the depth (height) thereof changes continuously, with higher speed. Moreover, since the viscosity of the ionizing radiation-curable resin is 0.1 to 1 Pa·s, it is possible to favorably express uneven irregular shapes where the depth (height) thereof changes continuously without the ionizing radiation-curable resin being too soft to run off and it is also possible to produce continuously with high speed without difficulties in providing the layer due to the resin being too hard.
In addition, a second aspect of a decorative material according to the present invention is the aforementioned decorative materials characterized in that a gloss adjusting layer having a gloss after its formation different to that of the ionizing radiation-curable resin layer after the formation thereof and also forms the surface of the aforementioned expression region, which is a recess or a salient, is provided and the ionizing radiation-curable resin layer is provided on the gloss adjusting layer.
In this invention, when the ionizing radiation-curable resin layer is made as a high gloss layer and the gloss adjusting layer is made as a low gloss layer for example, uneven irregular shapes expressed due to gloss will be more explicit. The invention also satisfies the effect of stress relaxation at the time of curing the ionizing radiation-curable resin due to this gloss adjusting layer and thus, can maintain excellent design.
Moreover, a third aspect of the decorative material according to the present invention is characterized in that it is the abovementioned decorative material where a base pattern is provided on the entire surface of the substrate and the picture pattern is partially provided in the base pattern.
This invention can achieve an excellent design stereoscopically by the base pattern present on the entire surface and the partially provided picture pattern, which expresses a recess or a salient.
Moreover, a fourth aspect of the decorative material according to the present invention is characterized in that it is the abovementioned decorative material where the picture pattern is formed from a water-based ink.
Since this invention uses the water-based ink, it is possible to reduce the amount of volatile organic compounds.
Moreover, a fifth aspect of the decorative material according to the present invention is characterized in that it is the abovementioned decorative material where a sealer layer formed from an aqueous resin is provided between the picture pattern and the substrate.
Since the sealer layer formed of an aqueous resin is provided, this invention is excellent in adhesive properties among respective layers and is capable of improving various surface resistances.
Moreover, a sixth aspect of the decorative material according to the present invention is characterized in that it is the abovementioned decorative material where the ionizing radiation-curable resin layer is formed from a monomer of (meth)acrylate-based resins.
Since the monomer based on (meth)acrylate is used, this invention is excellent in adhesive properties among layers with respect to the lower layer after coating while having a favorable viscosity and is capable of improving various surface resistances even when the thickness thereof is thin.
Moreover, a seventh aspect of the decorative material according to the present invention is characterized in that it is the abovementioned decorative material where silicone oil is added to the ionizing radiation-curable resin layer.
Since silicone oil is added, it is possible this invention to improve the surface stain resistance.
According to the present invention, it is possible to express uneven irregular shapes by the differences in surface gloss conditions even if the thickness is thin and also to improve productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an explanatory drawing showing the cross-sectional structure of a decorative material according to one embodiment of the present invention.
Fig. 2 is an explanatory drawing showing the cross-sectional structure of a modified example of a decorative material according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment according to the present invention will be described by referring to Fig. 1.
A decorative material 1 according to the present embodiment is a decorative material where a picture pattern 4 corresponding to an expression region 3, which is a recess or a salient, is provided on a substrate 2. The decorative material 1 has the picture pattern 4 partially provided in a base pattern 5, which is provided on the entire surface of the substrate 2, a gloss adjusting layer 6 provided by covering the picture pattern 4 and which forms the surface of the expression region 3, which is a recess or a salient, and an ionizing radiation-curable resin layer 7 provided in the vicinity of the outline of the picture pattern 4 except the expression region 3, which is a recess or a salient and which is immediately above the picture pattern 4, and which has a stepwise gradation in terms of gloss conditions. A sealer layer 8 formed from an aqueous resin is provided between the picture pattern 4 and substrate 2. Note that the expression region 3, which is a recess or a salient, means a region to visually express as a recess or a salient when compared to the part in which the ionizing radiation-curable resin layer 7 is provided.
For the substrate 2, various materials can be used depending on the purpose as conventionally known. Specifically, paper such as tissue paper, titanium paper, resin-impregnated paper, flameproof paper, and mineral paper; woven or non-woven fabrics formed from natural fibers or synthetic fibers; substrates based on synthetic resins such as homo- or random polypropylene resins, polyolefin-based resins such as polyethylene resins, copolyester resins, crystalline polyester resins in an amorphous state, polyethylene naphthalate resins, polybutylene resins, acrylic resins such as methylmethacrylate resins and polymethylmethacrylate resins, styrene-based resins, polyamide-based resins, cellulose-based resins, polycarbonate resins, polychlorinated vinyl resins, polychlorinated vinylidene resins, and fluorine resins; wood-based substrates such as a wood veneer, sliced veneer, plywood, glued laminated wood, particle board, and medium density fiber board; mineral substrates such as a gypsum board, cement plate, calcium silicate board, and ceramic board; metal substrates such as iron, copper, aluminium, and stainless steel; complexes thereof, laminated bodies thereof, or the like which are conventionally known arbitrary materials can be used and shapes thereof are not limited at all and film-forms, sheet-forms, board-forms, or atypical compact-forms can be adopted, for example.
Although materials constituting the base pattern 5 and picture pattern 4 are not particularly limited, together with an appropriate binder resin, printing ink or coating materials, which are formed by dissolving or dispersing coloring agents such as dyes or pigments in an appropriate solvent, are generally used.
As such coloring agents, for example, inorganic pigments such as carbon black, titanium white, zinc white, red iron oxide, chrome yellow, iron blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; or mixtures of two or more of these pigments can be used.
As binder resins, for example, various synthetic resins such as acrylic resins, styrene resins, polyester resins, urethane resins, polyvinyl resins, alkyd resins, petroleum resins, ketone resins, epoxy resins, melamine resins, fluororesins, silicone resins, cellulose resins, and gum resins, mixtures thereof, or copolymers thereof can be used.
As a solvent, for example, toluene, xylene, cyclohexane, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methylisobutylketone, cyclohexanone, water, or the like, or a mixture thereof can be used.
Other agents including various additives such as extender pigments, plasticizers, dispersing agents, surfactants, tackifiers, adhesion auxiliaries, desiccants, curing agents, curing accelerators, or concrete retarders are used where appropriate.
The base pattern 5 needs to contain, at least, the picture pattern 4 which corresponds to the expression region 3, which is a recess or a salient. On the other hand, it is also possible to make a decorative material 10 as one which is provided with, although not essential, a surface pattern 9 as shown in Fig. 2 in order to confer designs visually recognized as a color pattern, which is independent of uneven surface irregularities, in the vicinity of the outline of, but excluding immediately above, the picture pattern 4 which corresponds to the expression region 3, which is a recess or a salient.
For example, in the case of woodgrain patterns, it is common to separately print a base solid, woodgrain form, vessel pattern, or the like as conventionally known. Among them, the base solid and woodgrain form are provided as the base pattern 5 in the decorative material 1 of the present invention and the vessel pattern is provided as the picture pattern 4 which corresponds to the expression region 3, which is a recess or a salient. Needless to say, the base pattern 5 in the present invention is not limited to woodgrain patterns and it can be appropriately applied to rift patterns, abstract patterns, or the like.
Fig. 1 is described so that the picture pattern 4 which corresponds to the expression region 3, which is a recess or a salient, is provided on the surface of the base pattern 5. However, this does not necessarily define the upper and lower relationship between the two patterns and both patterns may be provided as a continuous picture form on an identical surface or in a manner where the upper and lower relationship between the two is reversed, or a transparent layer (transparent substrate is also possible) or the like may be interposed between the two patterns. In addition, the entire base pattern 5 or a part thereof may also be formed by being integrated with the substrate 2 by mixing or infiltrating coloring agents in the substrate 2. In short, when observed from the surface side of a decorative material, it is fine as long as the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient, and the base pattern 5 are configured so that the two patterns can be identified in terms of colors.
The base pattern 5 and picture pattern 4 are generally formed by appropriate printing methods such as the gravure printing method, offset printing method, screen printing method, electrostatic printing method, and ink-jet printing method. However, methods are not limited to those above and, for example, the aforementioned base solid may also be formed by coating methods such as the roll coating method, knife coating method, and die coating method. In addition, other patterns can also be formed by arbitrary image-forming methods which are conventionally known.
The gloss adjusting layer 6 is constituted from printing ink, coating agents, or the like, which are similar to those cited as the aforementioned constituting materials of the base pattern 5 and picture pattern 4. This is with the proviso that, since the gloss adjusting layer 6 needs to be provided with transparency, which makes at least the base pattern 5 and picture pattern 4 possible to be seen through the layer, as a printing ink, coating agents, or the like which form the layer, it is necessary to use those which contain no coloring agents such as dyes or pigments at all or only in a small amount to an extent where the required transparency is not impaired.
Additionally, since the gloss adjusting layer 6 is one which constitutes the most outer surface layer of the decorative material 1 in the expression region 3, which is a recess or a salient, the layer is preferably constituted from materials having a hardening resin as a major component to achieve surface physical properties required by the decorative material 1 such as abrasion resistance, scratch resistance, solvent resistance, and stain resistance. Specifically, for example, thermosetting resins such as melamine resins, epoxy resins, aminoalkyd resins, urethane resins, polyester resins, and silicone resins; or ionizing radiation-curable resins such as acrylic resins can favorably be used. Although the term "ionizing radiation" generally refers to a radiation which imposes ionization effects on substances and includes X-rays, γ-rays, β-rays (electron rays), and short wavelength ultraviolet rays, in the present invention, since UV-curable resins due to photoinitiators can also be used, the term also includes long wavelength ultraviolet rays, which do not impose ionization effects.
In order to express continuous changes in depth (height) by the changes in gloss conditions, the ionizing radiation-curable resin layer 7 is configured so as to change the gloss conditions thereof continuously or stepwise in the vicinity of the outline of the expression region 3, which is a recess or a salient. In other words, when proceeding from the outline of the expression region 3, which is a recess or a salient, towards the inside thereof, the gloss conditions change from one close to that of the surface of the region 3 to that in the part other than the vicinity of the picture pattern 4, which corresponds to the region 3.
To describe more specifically, when expressing the expression region 3 as a recess, the ionizing radiation-curable resin layer 7 is designed so as to have a higher gloss than that of the surface of the region 3. In addition, the ionizing radiation-curable resin layer 7 is formed by being provided with a gradation so that in the vicinity of the outline of the region 3, when departing from the outline of the region 3 and proceeding to the inside of the part where the ionizing radiation-curable resin layer 7 is formed, the gloss of the ionizing radiation-curable resin layer 7 gradually becomes higher.
On the other hand, when expressing the expression region 3 as a salient, the ionizing radiation-curable resin layer 7 is designed so as to have a lower gloss than that of the surface of the region 3. Moreover, the ionizing radiation-curable resin layer 7 is formed by being provided with a gradation so that in the vicinity of the outline of the region 3, when departing from the outline of the region 3 and proceeding to the inside of the part where the ionizing radiation-curable resin layer 7 is formed, the gloss of the ionizing radiation-curable resin layer 7 gradually becomes lower. When using a printing plate for the gravure printing method, in addition to the methods which use a film at the time of printing such as the chemical etching method (in which deviations in multistage alignment occur easily due to expansion and contraction of the film) or the mechanical engraving method, use of a laser-made plate will result in the large cell volume of the printing plate and difficulties in positional deviations even when multistage etching is carried out. Thus, it is possible to express gradation with better register accuracy.
Note that the outline of the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient, does not necessarily precisely coincide with the outline of the stair-like region 3 and it may be deviated to the inside or outside of the outline of the stair-like region 3 to some extent. It is also possible to appropriately adjust the virtual appearance of uneven irregularities by positively deviating the outlines of both patterns slightly from each other. In addition, it is also possible to confer changes in virtual appearance of uneven irregularities depending on places by changing directions or distances of deviations between the outlines of both patterns inside the stair-like region 3.
When expressing minute recesses or salients such as woodgrains and vessels, the parts in ionizing radiation-curable resin layer 7 where gradation is provided will also naturally become minute and a high degree of resolution is required also in printing plates, printing ink, or the like. On the other hand, in general two-component curable resins which are heavily used as surface coating agents of decorative materials, a curing reaction proceeds during printing resulting in the increase in viscosity thereof causing so-called plate fill in and thus, reproducibility of gradation is reduced in some cases.
Accordingly, resins used for the ionizing radiation-curable resin layer 7 are those having a viscosity of 0.1 to 1 Pa·s. This is because when the viscosity is within this range, favorable adhesive properties among layers are achieved. In addition, when the viscosity is lower than 0.1 Pa·s, layers will become too flexible and will easily collapse and when the viscosity exceeds 1 Pa·s, layers will become stiff and adhesive properties with the adjacent layers will be deteriorated.
As such resins, specifically, ionizing radiation-curable monomers, which do not increase the viscosity thereof with time during printing, are used. These resins do not increase the viscosity thereof since a curing reaction does not proceed when they are in a coating-liquid state at normal temperature during printing. On the other hand, since a curing reaction proceeds rapidly after resins are irradiated with ionizing radiation and resins are cured completely, there are advantages such as the lack of generation of blocking due to poor drying even when printed matter is retrieved or laminated.
As ionizing radiation-curable monomers, the compounds having ethylenic unsaturated double bonds can be used and these include monofunctional monomers, difunctional monomers, and polyfunctional monomers such as trifunctional monomers. Usually, the monomers are those which are not hydrophilic and for example, they do not have any of -CHO group, -OH group, and -COOH group.
Specific examples of monofunctional monomers which have ethylenic unsaturated double bonds include 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, caprolactone (meth)acrylate, ethoxylated nonylphenol (meth)acrylate, propoxylated nonylphenol (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene (meth)acrylate, ethylene oxide-modified nonylphenyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethylene oxide 2-ethylhexyl (meth)acrylate, and isobonyl (meth)acrylate dipropylene glycol (meth)acrylate. When it is described as "stearyl (meth)acrylate", for example, this shows it means stearyl acrylate and/or stearyl methacrylate (and same applies to others hereinafter).
Examples of difunctional monomers include 1,3-butanediol di(meth)acrylate, 1,4- butanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, (hydrogenated) bisphenol A di(meth)acrylate, (hydrogenated) ethylene oxide-modified bisphenol A di(meth)acrylate, (hydrogenated) propylene glycol-modified bisphenol A di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-ethyl-2-butylpropanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate.
Examples of polyfunctional monomers include tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, propoxylated glyceryl tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane (meth)acrylate, ethylene oxide-modified trimethylolpropane (meth)acrylate, propylene oxide-modified trimethylolpropane (meth)acrylate, tris(acryloxyethyl) isocyanurate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, penta(meth)acrylate ester, and dipentaerythritol hexa(meth)acrylate.
As ionizing radiation-curable monomers, monomers such as urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and polyacryl (meth)acrylate are desirable since their surface easily becomes smooth after coating due to their low viscosity and anchor effects to the sealer layer 8, base pattern 5, or the like also improve.
Silicone oil is added to the ionizing radiation-curable resin layer 7. This is added as an antipollution agent for preventing surface contaminants of the ionizing radiation-curable resin layer 7 from becoming attached or for allowing the attached contaminants to be easily wiped away with various detergents or solvents. Silicone oil is incorporated in the matrix resin constituted from ionizing radiation-curable monomers.
As a silicone oil, unmodified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, carboxy-modified silicone oil, mercapto-modified silicone oil, carbinol-modified silicone oil, methacryl-modified silicone oil, and phenol-modified silicone oil can be used. The amount of silicone oil is preferably 0.01 to 5 weight% when the total weight of ionizing radiation-curable monomers is taken as a standard. This is because when the amount of silicone oil is less than 0.01 weight%, effects of the addition thereof are not achieved and when the amount exceeds 5 weight%, the aqueous resins of the picture pattern 4 or the like are repelled to cause adhesive failures.
When the picture pattern 4 corresponding with the expression region 3, which is a recess or a salient, is expressed as a recess as described above, the gloss of the ionizing radiation-curable resin layer 7 needs to be designed higher than that of the gloss adjusting layer 6. On the other hand, when the picture pattern 4 corresponding with the expression region 3, which is a recess or a salient, is expressed as a salient, the gloss of the ionizing radiation-curable resin layer 7 needs to be designed lower than that of the gloss adjusting layer 6. In order to appropriately adjust gloss conditions of the ionizing radiation-curable resin layer 7, gloss-adjusting agents such as silica, alumina, calcium carbonate, and barium sulfate may be added where appropriate.
In many cases, it is more advantageous from the viewpoint of visually-obtained stereoscopic vision of uneven irregularities that the gradation provided in the ionizing radiation-curable resin layer 7 be a stepwise gradation in terms of changes in gloss conditions as shown in Fig. 1 even when the aim is to express continuous changes in depth (height). In particular, since there are many cases where continuous gradation results in a poor sense of tone although the size of uneven irregularities is highly minute (for example, like the case of vessel grooves of wood or the like where stereoscopic vision present in the cross-sectional shape of a natural vessel groove is not sufficiently expressed), it is preferable that gradation be stepwise.
As a method to provide gradation in gloss conditions of the ionizing radiation-curable resin layer 7, for example, a gravure printing method is used and it is carried out by changing the depth or area ratio of the gravure printing plate so that desired gradation is achieved. Other printing methods such as a general offset printing method, screen printing method, electrostatic printing method, and ink jet method are also used where appropriate.
Note that the abovementioned gradation is not limited to the gradation due to changes in the coating amount of ionizing radiation-curable resins and it is possible to express gradation due to changes in area ratio of halftone dots or the like (not illustrated) and it is also possible to use changes in the coating amount and changes in the area ratio concomitantly (not illustrated).
This is with the proviso that these differences are not necessarily fundamental since generally speaking, even when the design on the printing plate is in the form of halftone dots, it is common to become more or less continuous due to resin flow at the time of printing. Although a description is hereinafter provided using the stepwise figure as shown in Fig. 1 to be brief, this includes all the various techniques for the expression of gradation mentioned above.
When the expression region 3 is expressed as a recess, the surface of the expression region 3 must be in a low-gloss condition. In order to achieve the condition, as shown in the example in Fig. 1, when the base pattern 5 corresponding to the expression region 3 is exposed in the surface in the region 3, there is a need to adjust the pattern in a low-gloss condition by appropriately adding gloss adjusting agents or the like to printing ink or the like, which forms the base pattern 5. On the other hand, when the expression region 3 is expressed as a salient, there is a need to use printing ink, which makes the surface gloss after printing high, as the printing ink to form the picture pattern 4 corresponding to the region 3.
The positional relationship between the expression region 3, which is a recess or a salient, and the base pattern 5 corresponding to the region 3 is mentioned again here. When expressing a recess or a salient where only the bottom face of the recess or the top face of the salient has different colors from the other parts, there is a need to form the base pattern 5 having an identical outline to that of the region 3. On the other hand, when expressing a recess or a salient where slope sections of the outline of the recess or the salient also have identical colors to that of the bottom face or the top face, it is preferable to form the base pattern 5 in the region where the ionizing radiation-curable resin layer 7 reaches the outline of a region, which is outside the expression region 3 and has gradation. For example, when imitation of vessel grooves in the cross-section of natural wood is aimed at, the latter configuration is recommended.
In addition, when expressing the state where colors continuously change in the slope sections of the outline of the recess or the salient, it is good to provide gradation in the color of the base pattern 5 in the region, which is in the vicinity of the outline of the region 3 and where the ionizing radiation-curable resin layer 7 has gradation. Alternatively, it is also possible to achieve an analogous visual expression effect by placing the outline of the base pattern 5 in the middle of internal and external outlines of the region where the ionizing radiation-curable resin layer 7 has gradation. Additionally, it is also possible to express complex uneven irregular shapes where the appearance of uneven irregularities changes depending on the position by adopting the combinations of various expression techniques described so far depending on the position.
Specific examples where the present invention is applied are most represented by the expression of vessel grooves of natural wood as already mentioned many times. Since vessel grooves are physically recesses, the configuration where surface gloss of the vessel-pattern part is made low and the ionizing radiation-curable resin layer 7 having a high gloss is provided on the surface except the vessel-pattern part is generally adopted. However, there are also cases where it is better to reverse the high and low state of gloss from the above to achieve reality like the case when expressing the types of trees whose color tones of the wood surface are light and vessel-groove parts appear to come to the surface such as certain types of coniferous wood.
According to such a decorative material 1, it is possible to express uneven irregular shapes where the depth (height) changes continuously like vessels of natural wood or the like since the ionizing radiation-curable resin layer 7 is provided on the surface of the decorative material 1 so as to have gradation in gloss conditions. By making the viscosity of the ionizing radiation-curable resin 0.1 to 1 Pa·s at this juncture, it is possible to favorably express uneven irregular shapes where the depth (height) thereof changes continuously without the ionizing radiation-curable resin being too soft to run off and it is also possible to produce the decorative material 1 continuously at a high speed without difficulties in providing the layer due to the resin being too hard. Moreover, the stress generated at the time when the ionizing radiation-curable resin is cured can be favorably relaxed and peeling among layers can favorably be suppressed.
Additionally, by making the ionizing radiation-curable resin layer 7 as the high gloss layer and by providing the gloss adjusting layer 6 with low gloss between the layer 7 and the picture pattern 4, it is possible to make the expression of uneven irregular shapes due to gloss more distinctly. Furthermore, due to this gloss adjusting layer 6, the stress generated when the ionizing radiation-curable resin is cured can be relaxed and peeling of the picture pattern 4 or the base pattern 5 or the like can be suppressed. For this reason, it is possible to favorably maintain more stereoscopically excellent design achieved by the base pattern 5 on the entire surface and the picture pattern 4, which is partially provided and which expresses a recess or a salient.
In addition, by using a water-based ink in the picture pattern 4, it is possible to reduce the amount of volatile organic compounds. Moreover, since the sealer layer 8 formed of an aqueous resin is provided on the substrate 2, adhesive properties among respective layers will be excellent and various surface resistances can be improved.
Additionally, by using monomers based on (meth)acrylate in the ionizing radiation-curable resin layer 7, adhesive properties among layers with respect to the lower layer after coating will be excellent even with a favorable viscosity and various surface resistances can be improved.
Moreover, since silicone oil is added to the ionizing radiation-curable resin layer 7, it is possible to improve the surface stain resistance.
Note that the scope of techniques of the present invention is not limited to the above embodiment and various changes can be made within the range not deviating from the scope of the present invention.
For example, in the above embodiment, it is implicitly assumed that gloss conditions of the ionizing radiation-curable resin layer 7 in the part other than the vicinity of the expression region 3, which is a recess or a salient, are constant. However, for example, it is also possible to confer changes conforming with woodgrain patterns to gloss conditions of the ionizing radiation-curable resin layer 7 in order to express gloss differences between the spring-wood part and autumn-wood part in natural wood or gloss differences due to angles between sections and woodgrain directions. By doing so, it is possible to achieve a decorative material extremely excellent in design properties, which is closer to natural wood, coupled with the aforementioned true expression of shapes of vessel-groove parts.

[Example 1]

Tissue paper with a basis weight of 29 g/m² ("HPN-29" produced by Tentok Paper Co., Ltd.) was used as the substrate 2. An aqueous urethane-based coating (a mixture of 100 parts of "LW059 SEALER" and 5 parts of "LT109 HARDERNER" both produced by Toyo Ink MFG. Co., Ltd.) was coated on the surface thereof as a sealer layer 8 formed of an aqueous resin so that the coating amount after drying will be 2 g/m².
A colored solid layer of one color was printed thereon on the entire surface by gravure printing using an aqueous acrylic resin-based gravure printing ink ("PCW" produced by Toyo Ink MFG. Co., Ltd.) as a water-based ink of the base pattern 5. Furthermore, a woodgrain pattern was printed and a vessel pattern, which conformed with the woodgrain pattern, was sequentially printed as the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient.
A resin ("LT097EB Primer" produced by Toyo Ink MFG. Co., Ltd.) formed from an acrylic resin, in which silica powder was added to adjust the gloss thereof to low, urethane resin, casein, trifunctional monomer, and an additive was coated on the entire surface of the above patterns as the gloss adjusting layer 6 so that the coating amount after drying will be 5 g/m². Then an ionizing radiation-curable resin (a mixture of 50 weight parts of pentaerythritol tri(meth)acrylate, 50 weight parts of ethoxylated trimethylolpropane (meth)acrylate, and 0.5 weight parts of amino-modified silicone oil) formed from silicone acrylate monomer to achieve high gloss was coated as the ionizing radiation-curable resin layer 7 on the surface except the vessel-pattern part with a coating amount of 4 g/m² by providing gradation in the vicinity of the outline of the vessel-pattern layer.
Thereafter, an electron beam was irradiated in a nitrogen atmosphere under the irradiation conditions of 45 KGy (5 Mrad) dose, 1.5 kV, 100 mA, and line speed of 200 m/min to cure the ionizing radiation-curable resin.
When the decorative material obtained as described so far was retrieved, blocking did not occur.

[Example 2]

Tissue paper with a basis weight of 29 g/m² ("HPN-29" produced by Tentok Paper Co., Ltd.) was used as the substrate 2. A colored solid layer of one color was printed thereon on the entire surface using a gravure printing ink formed of an oil-based acrylic resin ("PCNT" produced by Toyo Ink MFG. Co., Ltd.) as the base pattern 5. Furthermore, a woodgrain pattern was printed and a vessel pattern (150 lines in line number of a pattern printing-plate), which conformed with the woodgrain pattern, was sequentially printed as the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient.
A coating (a mixture of 100 parts of "EXP-UV60425 mat" and 10 parts of "W325N") formed from a two-component curable urethane resin, in which silica powder was added to adjust the gloss thereof to low, and a UV-curable resin was coated on the entire surface of the above patterns as the gloss adjusting layer 6 so that the coating amount after drying will be 5 g/m².
Then a UV-curable resin (a mixture of 50 parts of "EXP-UV60425 HighMat" and 50 parts of "EXP-UV60425 gloss" both produced by Dainippon Ink and Chemicals Inc.) formed from a urethane acrylate monomer to achieve high gloss was coated as the ionizing radiation-curable resin layer 7 on the surface except the vessel-pattern part with a coating amount after drying of 2 g/m² by providing gradation (line number of 100 lines) in the vicinity of the outline of the vessel-pattern layer.
Thereafter, ultraviolet rays were irradiated in an air atmosphere under the irradiation conditions using two metal halide lamps of 160 W/cm and a line speed of 100 m/min to cure the UV-curable resin. When the decorative material obtained as described so far was retrieved, blocking did not occur.
Thereafter, although an electron beam-curable colored enamel coating (produced by Toyo Ink MFG. Co., Ltd.) is provided as the surface pattern 9 only on the surface of the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient, the provision was easily carried out without any problems such as gradation collapse or positional deviations.

In the configuration of Example 2, block isocyanate-curable urethane resin (produced by Toyo Ink MFG. Co., Ltd.) was used instead of the UV-curable resin (a mixture of 50 parts of "EXP-UV60425 HighMat" and 50 parts of "EXP-UV60425 gloss" both produced by Dainippon Ink and Chemicals Inc.). Although uneven irregular shapes, which had sloping sections where the depth (height) thereof changed continuously, are provided with a line speed of 80 m/min in the vicinity of the region of the picture pattern 4 corresponding to the expression region 3, which is a recess or a salient, blocking occurred at the time of retrieving. Although the surface pattern 9 was further provided thereafter, gradation collapsed and design properties thereof were impaired.
The decorative materials obtained in each of the abovementioned Examples were decorative materials having an appearance of uneven irregularities of vessel grooves, which is analogous to natural vessels, due to the gradation in gloss conditions in the outline section of the vessel pattern and excellent in design properties. Moreover, they could be produced with good workability without generating problems such as the so-called plate fill in during printing, blocking due to poor drying, or trapping.

[Industrial Applicability]

The present invention can be used as a decorative material for interior and exterior finishing of buildings and architecture, fittings, or surface decorations or the like of furniture. More specifically, the present invention can be used as a decorative material which, in the case of a woodgrain pattern for example, expresses uneven irregularities such as vessel parts stereoscopically by differences in surface gloss.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.

Claims

A decorative material comprising:
a substrate;

an expression region, which is a recess or a salient;

a picture pattern on the substrate which corresponds to the expression region;
and

an ionizing radiation-curable resin layer;

wherein the ionizing radiation-curable resin layer is provided in a vicinity of an outline of the picture pattern except immediately above the picture pattern so as to have a stepwise gradation in gloss conditions, and

wherein a viscosity of the ionizing radiation-curable resin layer is 0.1 to 1 Pa·s.
The decorative material according to Claim 1 further comprising a gloss adjusting layer,
wherein the gloss adjusting layer has a gloss after formation thereof which is different from that of the ionizing radiation-curable resin layer after formation thereof and forms a surface of the expression region, which is a recess or a salient, and
wherein the ionizing radiation-curable resin layer is provided on the gloss adjusting layer.
The decorative material according to Claim 1 or 2 further comprising a base pattern, wherein the base pattern is provided on an entire surface of the substrate and the picture pattern is partially provided in the base pattern.
The decorative material according to Claim 1, wherein the picture pattern is formed from a water-based ink.
The decorative material according to Claim 4 further comprising a sealer layer, wherein the sealer layer is provided between the picture pattern and the substrate and is formed from an aqueous resin.
The decorative material according to Claim 4, wherein the ionizing radiation-curable resin layer is formed from a (meth)acrylate-based resin.
The decorative material according to Claim 5, wherein the ionizing radiation-curable resin layer is formed from a (meth)acrylate-based resin.
The decorative material according to Claim 6 or 7 further comprising silicone oil; wherein the silicone oil is added to the ionizing radiation-curable resin layer.