JP2001096707A - Decorative laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the insufficiency of a surface resistance to staining such as seen in a conventional decorative laminated sheet and also eliminate the easy susceptibility to curling in the case of an EB decorative laminated sheet having a sheetlike base material. SOLUTION: In order to address the issues of insufficient surface resistance to staining and easy susceptability to curling, a melamine acrylate compound having preferably two or more reactive hydroxyl groups is used for the formation of a surface protecting layer. In addition, for a crosslinking agent, an isocyanate compound or a polyfunctional acrylate compound is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative material having a surface protective layer made of a cross-linked and cured resin, and particularly to a sheet-like material having excellent surface contamination resistance and a thin substrate. However, the present invention relates to a decorative material which is less likely to curl due to shrinkage due to crosslinking and curing during formation of the surface protective layer.

[0002]

2. Description of the Related Art Cosmetic materials are used inside and outside buildings, furniture surfaces,
Alternatively, it covers the surface of various articles in the living environment for the purpose of decoration. Further, many decorative materials also have a role of protecting the above-mentioned various articles by selecting the base material. When a cosmetic material is used in a place where the frequency of use is high, it is common to select a material having a surface protection layer made of a curable resin and having higher durability.

[0003] By the way, various materials adhere to the surface of the cosmetic material depending on the applied environment, and may remain without being completely removed by wiping or the like, resulting in contamination. The type of contamination and the likelihood of contamination are classified according to the nature of the surface to which the cosmetic material is applied, such as a horizontal surface such as a table, desk or furniture top surface, furniture door or wall etc. There is a vertical surface and a ceiling surface, and in general, food and cosmetics are spilled on the table and dressing table, and the frequency of contamination is high due to the attachment of droplets. Many of the substances that cause pollution include the substances that are easily dyed on the target object, and the environment to which the cosmetic material is applied also has an effect.

[0004] Among the conventional decorative materials, melamine decorative boards, which are considered to have various durability, require various steps for their production and, furthermore, go through a hot pressing step, so that they can be produced continuously. Disadvantages such as unsuitability are inevitable. Therefore,
Printing on a sheet-like base material such as paper or plastic film, conventionally, in order to form a surface protective layer, a curable paint such as polyurethane resin is applied, and instead of a coating type decorative sheet that has been cured, An electron beam-cured decorative sheet (EB decorative sheet, especially when the substrate is on the upper side, particularly called EB decorative paper) is used, in which the surface protective layer is formed by applying an electron beam-curable paint and crosslinking and curing by irradiation with an electron beam. More often.

As an example of the surface protective layer in the EB decorative sheet, there is a cross-linked by irradiation with electron beam using diacrylate of bisphenol A ethylene oxide adduct together with trimethylolpropane triacrylate. However, the surface protective layer according to this formulation has insufficient contamination resistance and the surface protective layer shrinks during crosslinking,
The resulting EB decorative sheet is easily curled and has a small diameter curl, so that there are many troubles in handling.

[0006]

SUMMARY OF THE INVENTION In the present invention, it is possible to solve the problem that the surface of a conventional decorative material is insufficient in stain resistance and to provide an EB decorative sheet having a sheet-like base material. The object of the present invention is to eliminate the tendency to curl.

[0007]

In order to form a surface protective layer, a melamine acrylate compound having two or more reactive hydroxyl groups is preferably used, and as a crosslinking agent, an isocyanate compound or a polyfunctional compound is preferably used. The problem could be solved by using an acrylate compound.

[0008] The first invention relates to a decorative material characterized in that a surface protective layer in which a melamine acrylate compound is cured by a crosslinking agent is laminated on a decorative substrate. The second invention relates to a cosmetic material according to the first invention, wherein the melamine acrylate compound has a reactive hydroxyl group, and the crosslinking agent is an isocyanate compound. A third invention is the decorative material according to the second invention, wherein the melamine acrylate compound has one or more reactive hydroxyl groups, and the crosslinking agent is an isocyanate compound having two or more isocyanate groups. It is about. The fourth invention is
In the first aspect, the present invention relates to a decorative material, wherein the crosslinking agent is a polyfunctional acrylate compound.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the structure of a decorative material 1 which is an object of the present invention will be described. The decorative material 1 has a colored layer 3 by coloring, The pattern layer 4 is formed and the makeup is applied. The makeup is applied and the surface protection layer 5 is further laminated. As shown in FIG. 2, the decorative material 1 may be laminated on another base material 7 via an adhesive layer 6 on the lower surface of the base material 2. As the base material 2, a sheet-like material may also be used.
A plate-like material can be used, but in the case shown in FIG. 2, for example, the upper substrate 2 can be in a sheet shape, and the lower substrate 7 can be in a plate shape. In the case as shown in FIG. 1, the substrate 2 may be a sheet or a plate. In addition, among the sheet-like base materials, those using paper include decorative paper and decorative paper, and those including base materials such as plastic sheets are also referred to as decorative sheets. Moreover, what used the plate-shaped base material is called a decorative board, and the board mentioned here is not limited to a wooden board. The decorative material referred to in the present invention includes all decorative papers, decorative sheets, and decorative boards.

In the example described with reference to FIGS. 1 and 2, two types of coloring and patterning are applied as makeup. When printing in the field of cosmetic materials, this structure may be adopted. As usual, the makeup may be colored or patterned. As other makeup, embossing, wiping painting for coloring recesses by embossing, gloss adjustment, pattern formation by gloss difference, and the like may be performed.

As the base materials 2 and 7, any materials can be used as long as they are usually used for decorative materials. Broadly classified, papers of various types and thicknesses, plastic films, plastic sheets or plastic plates, metal foils, metal sheets or metal plates, wood-based plates such as wood, or various ceramic materials Group.

The materials contained in each of these groups may be used alone, but a laminate of any combination of these materials, such as a composite of paper and a composite of paper and plastic, can also be used. These base materials may be painted for the purpose of adjusting colors, or may be formed with a normal pattern in advance from the viewpoint of design. Prior to painting or normal pattern formation, the surface may be smoothed or a base treatment may be applied to increase the degree of adhesion of the pattern. After painting or forming a normal pattern, an adhesion improving treatment for facilitating subsequent processing may be performed.

Examples of various papers include tissue paper, kraft paper, titanium paper, resin-impregnated paper which has been impregnated with a resin for the purpose of strengthening the paper, linter paper, paperboard, gypsum board base paper, or the surface of paper. A group of raw materials often used in the field of building materials, such as a raw material of vinyl wallpaper provided with a vinyl chloride resin layer.

As the papers, the following papers used in the office field, ordinary printing, packaging and the like can be used. That is,
Examples include coated paper, art paper, sulfuric acid paper, glassine paper, parchment paper, paraffin paper, and Japanese paper. Although different from these papers, woven or non-woven fabrics of the following various fibers having the same appearance and properties as paper can also be used as the substrates 2 and 7. Various fibers are glass fiber, asbestos fiber,
It is an inorganic fiber such as potassium titanate fiber, alumina fiber, silica fiber, or carbon fiber, or a synthetic fiber such as polyester fiber or vinylon fiber.

Examples of the plastic film, plastic sheet, or plastic plate include those made of various synthetic resins as exemplified below. Various synthetic resins include polyethylene resin, polypropylene resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene -Vinyl alcohol copolymer resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, polymethyl methacrylate resin, polyethyl methacrylate resin, polybutyl acrylate resin, nylon 6 or nylon 66, etc. Polyamide resin, cellulose triacetate resin, cellophane, polystyrene resin, polycarbonate resin, polyarylate resin, polyimide resin and the like.

The metal foil, metal sheet or metal plate is made of a metal as exemplified below. That is, aluminum, iron, stainless steel, copper, or the like. It is often used after plating. Examples of various wood-based boards include a wood board, a plywood, a particle board, and a medium-density fiberboard called MDF. Examples of the ceramic material include ceramic building materials such as gypsum board, calcium silicate plate, and wood chip cement plate, ceramics, glass, enamel, and fired tile. In addition, composites of various materials such as a fiber reinforced plastic plate, a paper honeycomb having iron plates stuck on both sides, and a two-aluminum plate sandwiched by a polyethylene resin can be used as the bases 2 and 7. .

When printing on the base material 2, it is preferable to select an appropriate ink in consideration of the adhesiveness to the base material 2 and to perform printing by a printing method. When the pattern layer 4 is formed by printing,
The coloring layer 3 may also be formed by printing. Pattern layer 4
In the case where only the colored layer 3 is formed without forming the coloring layer 3, coating may be performed. Printing is performed not only on the upper surface of the substrate 2 but also on the substrate 2
When a transparent material is selected, the printing may be performed on the lower surface of the base material 2 or at least the upper side may be printed between two transparent base materials.

The ink used for printing is prepared by dissolving or dispersing an appropriate binder resin, a dye or pigment as a colorant, a solvent or a diluent, and various additives which may be added as necessary. It is kneaded. The paint has almost the same components as the ink, and although it cannot be said unconditionally, a solvent or a diluent which requires a longer drying time than the ink is used.

As the binder resin for the ink or paint, rosin, rosin-modified maleic resin, nitrocellulose, cellulose acetate, cellulose butyrate, ethylcellulose, polyamide resin, chlorinated rubber, cyclized rubber, polyamide resin, polyvinyl chloride resin, Vinyl chloride / vinyl acetate copolymer resin, ethylene / vinyl acetate copolymer resin, ethylene / acrylate copolymer such as ethylene-ethyl acrylate, chlorinated polypropylene, acrylic resin, polyurethane resin, styrene-male resin, polyvinyl acetate Resin, polyvinyl alcohol, polyvinyl acetal (polyvinyl formal, polyvinyl butyral, etc.), cyanoacrylate, polyvinyl alkyl ether, urea resin, melamine resin, phenol resin, resorcinol resin, Down resins, epoxy resins, unsaturated polyester resins, polyurethane resins, polyimide, polyamide-imide, polybenzimidazole, or polybenzothiazole and the like can be used.

As the printing, a known printing technique can be used. Since the substrate 2 can be made of various materials, gravure printing, which is easy to cope with by changing the ink binder even when the material changes, is often used, but other methods may be used, for example, lithographic offset printing, letterpress printing. In addition to long-used methods such as printing, flexographic printing, and silk screen printing, as well as relatively new methods,
Ink jet and electrophotographic techniques can also be used.

The pattern of the pattern layer 3 at the time of printing can be appropriately selected according to the application. As an example, there is a concrete pattern or an abstract pattern such as a wood grain pattern, a cloth grain pattern, or a pattern imitating a pattern of marble or the like.

The formation of the colored layer can also be performed by painting.
As the coating method, the above-described printing method can also be used as a coating method because a uniform color can be applied to one surface. In addition to the printing method, roll coating, dip coating, kiss coating, spray coating, pouring coating, wheeler coating, spinner coating, curtain flow coating, or the like can be used. In the point that it is possible to apply a uniform color over the whole surface, the printing method and the painting method are similar, but in general, the painting method is thicker, about several tens of μm, When the printing method is used, it is around several tens of μm.

The embossing process, which is one of the cosmetics, is performed by, for example, providing the substrate 2 with a concave / convex pattern which is related to various patterns as described in the pattern layer 3 or a concave / convex pattern which is not necessarily related. It is to be. For example, when there is the pattern layer 3, it is an uneven pattern that matches the pattern of the pattern layer 3, or an uneven pattern that does not necessarily need to match the pattern of the pattern layer 3, such as a satin pattern. Among embossing processes, there are those that impart fine irregularities, and are used to adjust the gloss of the surface of the decorative material.

In order to perform embossing, an embossed die plate having an inversed shape of the irregularities required on the surface of the decorative material on the surface, or an embossing roll having irregularities formed continuously on the surface of a metal roll or the like is used. While using the embossing plate and heating the substrate 2 and / or the embossing plate as necessary,
The surface of the embossing plate is transferred to the surface of the base material 2 by applying pressure to the base material 2 and applying pressure. Note that the embossing may be performed on the outermost surface of the decorative material, that is, on the surface protective layer 5, but the embossing may be performed before the surface protective layer 5 is formed.

In some cases, a colorant is filled in concaves and convexes formed by embossing. A paint or ink as a colorant is supplied onto a substrate having a concave portion, and excess paint or ink is wiped off (= wiping) to leave the colorant in the concave portion. For example, if a wood grain conduit pattern is formed as a concave portion and a relatively dark colorant is filled in the concave portion, a wood-grained decorative material in which the conduit is expressed in a strong tone is obtained, which is called wiping painting. Note that the wiping coating may be performed on the outermost surface of the decorative material, that is, on the surface protective layer 5, but the surface protective layer 5 may be formed after performing the wiping coating.

The above are examples of cosmetics that are often applied to cosmetic materials. In addition, dyeing, flocking, embroidery, attaching metal foil, attaching cut-out sheets of pattern shape, etching with acid or alkali Coloring by anodic oxidation or sandblasting can also be applied as makeup.

Of the materials constituting the surface protective layer 5, the main one is melamine acrylate. To obtain melamine acrylate, first, the methylol group of methylol melamine obtained by reacting the amino group of melamine (C ₃ H ₆ N ₆ ) with formaldehyde (HCHO) is converted to an alcohol (for example, having about 1 to 4 carbon atoms such as methanol). To produce an alkoxymethylmelamine, followed by reaction with 2-hydroxyethyl acrylate or the like to produce an acryloyl group at the alkoxymethyl group. In order to cure the surface protective layer by electron beam irradiation, the number of acrylate groups in the melamine acrylate is preferably two or more, and more preferably three or more polyfunctional. Melamine acrylate includes
The crosslinking density can be adjusted by using a crosslinking agent which is a polyfunctional acrylate.

Examples of the crosslinking agent which is a polyfunctional acrylate include ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, and dipropylene. Examples thereof include glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

By the way, the number of amino groups of melamine is 3, and the total number of hydrogens attached to the amino groups is 6, so that the maximum number of alkoxymethyl groups is 6. Reduce the number of introducing this alkoxymethyl group, or
Once six alkoxymethyl groups are introduced, a part of them is returned to the form of a methylol group, whereby the number of hydroxyl groups in the methylol group can be controlled in the range of 0 to 6. Therefore, when melamine is cross-linked using a cross-linking agent, the cross-link density of melamine acrylate can be controlled by changing the number of hydroxyl groups. When the crosslink density of melamine is changed and the crosslink density is increased in this way, the stain resistance is improved. The number of hydroxyl groups introduced is preferably 1 or more in the sense of improving stain resistance, and if it is 3 or more, there is no contamination by almost any substance.
In the above example, an acrylate group is introduced into melamine, but another vinyl group may be introduced instead of the acrylate base.

The cross-linking agent for cross-linking melamine is preferably a cross-linking agent having two or more functional groups in the molecule capable of reacting with the hydroxyl group of melamine having the above-mentioned hydroxyl group introduced therein. Isocyanate (TDI) or xylylene diisocyanate (X
An isocyanate compound having two or more isocyanate groups such as DI) can be used, and extremely excellent stain resistance can be obtained, and the decorative sheet has an appropriate curl and is easy to handle. However, in the present invention, since the use of melamine acrylate has a great effect, even if the above-mentioned polyfunctional acrylate is used as a cross-linking agent, the stain resistance is excellent, and even in the case of a decorative sheet, it is hard to curl. The use of a polyfunctional acrylate also has the advantage that the reaction is faster.

The melamine acrylate and the crosslinking agent are mixed with a filler or other additives, a solvent, or a diluent, if necessary, to obtain a coating composition. Then, it is applied on a makeup-applied base material to be applied by an appropriate application means to form a coating film. As a method of application, the method described as a method of forming a colored layer can be used. As the thickness of the coating film, 2μm ~ 50μ
m. After the application, the thermosetting component in the coating film is reacted by heating. In the case of the melamine acrylate having a hydroxyl group and the isocyanate compound, the reaction between the hydroxyl group in the melamine acrylate and the isocyanate proceeds. The reaction conditions are, for example, about 1 minute at 120 ° C., and depending on the coating speed, this time is almost equivalent to the time required to pass through a drying zone in a general coater.

Subsequently, the coating film is irradiated with an electron beam to cure the coating film. As the electron beam source, various electron beam accelerators such as a Cockcroft-Walton type, a bande graph type, a resonance transformer type, an insulating core transformer type, a linear type, a dynamitron type and a high frequency type are used.
V, preferably one that irradiates electrons having an energy of 100 to 300 KeV. In the decorative material of the present invention, it is advantageous to increase the thickness of the coating film, and an electron beam is advantageous in terms of permeability, but ultraviolet rays can also be used. In this case, the ultra-high pressure mercury lamp,
Light sources such as a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc lamp, a black light, and a metal halide lamp can be used.

The surface protective layer 5 preferably contains inorganic particles which are inorganic and have a higher hardness than the crosslinked and cured resin in order to improve the wear resistance of the surface of the layer.
The addition of high hardness spherical particles achieves further surface strengthening. Here, the spherical particles do not need to be true spheres, but may have any smooth surface. The role of the spherical particles is to protrude a part of the surface of the surface protective layer, receive the external force that causes abrasion on the spherical particles, and prevent the wear of the lower layer by gradually wearing the spherical particles themselves. is there. Spherical particles include α-alumina, silica, chromium oxide, iron oxide, diamond, graphite, etc. Among them, spherical α-alumina (shown by Showa Denko KK) Alumina AS-10 to AS50) can be recommended. The average particle diameter of the spherical particles is 1 to 10 μm.
The degree is preferred. When inorganic spherical particles are used for the surface protective layer, they may be treated in advance with a silane coupling agent or the like in order to increase the adhesion in the resin constituting the surface protective layer.

A slipping agent may be added to the surface protective layer for the purpose of improving the surface slip and preventing damage due to rubbing. Wax, silicone oil and the like can be used as the slip agent. It is preferable to use silicone acrylate from the viewpoint of preventing bleeding from the surface protective layer.

[0035]

Example: Printing paper for construction materials (manufactured by Tenma Special Paper Co., Ltd., S
WC30, weight 30 g / m ² ) using gravure ink for decorative paper (HAT, manufactured by The Inktec Co., Ltd., HAT, binder resin; acrylic resin and nitrocellulose), and by gravure printing, uniform color on one side A printed sheet was formed by forming a colored layer and a pattern layer. Then, using a roll coater on the print sheet,
An electron beam curable resin composition of various compositions was applied in an amount of 10
g / m ² (at the time of application) to form a coating film, and then heated at 120 ° C. for 1 minute through a heat drying zone. After heating, acceleration voltage 175 KeV, irradiation dose 5M
The coating film was cured by irradiating rad electron beams to obtain an EB decorative paper having a surface protective layer.

The stain resistance test of the obtained EB decorative paper was performed as follows. Samples were collected from each, and each of the commercially available substances was applied to the surface protective layer side for a stain resistance test, covered with a cover glass, and allowed to stand for 24 hours.
The cover glass was removed, the surface was wiped with a dry cloth to remove each substance, and the state of the surface was observed. In Table 1 below,
Each component (leftmost column) and the blending weight ratio of the six types of electron beam-curable resin compositions used in Examples and Comparative Examples,
"Table 2" shows the stain resistance test substances used (leftmost column) and the results of the stain resistance test of the cosmetic materials of Examples and Comparative Examples for each substance. The meanings of ○, Δ, and × in the results of the stain resistance test in “Table 2” are as follows. ；: No change or very slight change compared to before the test. Δ: There is a slight change compared to before the test, but it is inconspicuous if it is a light-colored decorative paper. X: There is a remarkable change compared to before the test.

[0037]

[Table 1]

[0038]

[Table 2]

As is clear from Tables 1 and 2, in the conventional product of the comparative example, contamination was not completely eliminated even if the composition was changed, and the decorative paper was curled severely. On the other hand, in the decorative paper of the present invention, melamine acrylate was used, so that the melamine acrylate was excellent in stain resistance, especially when the melamine acrylate having a hydroxyl group was crosslinked and cured with an isocyanate compound. Has very good stain resistance.

[0040]

According to the first aspect of the present invention, since the surface protective layer is composed of melamine acrylate, it is possible to provide a cosmetic material having excellent stain resistance and less curling. According to the invention of claim 2, in addition to the effect of the invention of claim 1, since an isocyanate compound is used as a cross-linking agent, it is possible to provide a cosmetic material having particularly excellent stain resistance. According to the invention of the third aspect, similarly to the invention of the second aspect, it is possible to provide a cosmetic material having particularly excellent stain resistance. According to the invention of claim 4, in addition to the effect of the invention of claim 1, it is possible to provide a cosmetic material which is rapidly cured by electron beam irradiation and can be manufactured quickly.

[Brief description of the drawings]

FIG. 1 is a sectional view of a decorative material.

FIG. 2 is a cross-sectional view of a decorative material stuck on another substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cosmetic material 2, 7 Base material 3 Colored layer 4 Pattern layer 5 Surface protective layer 6 Adhesive layer

Claims (4)

[Claims] 1. A decorative material comprising: a surface protective layer in which a melamine acrylate compound is cured by a cross-linking agent; 2. The cosmetic material according to claim 1, wherein the melamine acrylate compound has a reactive hydroxyl group, and the crosslinking agent is an isocyanate compound. 3. The cosmetic material according to claim 2, wherein the melamine acrylate compound has one or more reactive hydroxyl groups, and the crosslinking agent is an isocyanate compound having two or more isocyanate groups. 4. The cosmetic material according to claim 1, wherein the crosslinking agent is a polyfunctional acrylate compound.