JP2014074263A - Method for manufacturing foamed wall paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a foamed wall paper having a new surface design on which a surface unevenness is formed by a new chemical embossing method.SOLUTION: A method for manufacturing a foamed wall paper at least having a foamed resin layer and a surface protective layer on a paper substrate, comprises forming an ionizing radiation curable resin layer on an outermost surface thereof with patterned shape and forming a concave portion in which the ionizing radiation curable resin layer is formed, viewed from a region in which the ionizing radiation curable resin layer is not formed. The method comprises (1) a step 1 forming at least foamed agent containing resin layer on the paper substrate, (2) a step 2 forming the surface protective layer on the foamed agent containing resin layer, (3) a step 3 applying and curing an ionizing radiation curable resin containing a foamed retardant on the outermost surface with patterned shape to form the ionizing radiation curable resin layer and (4) a step 4 heating the foamed agent containing resin layer to form the foamed resin layer, on their order.

Description

  The present invention relates to a method for producing a foam wallpaper having a novel surface irregularity pattern.

  A so-called chemical embossing method is known as one of means for forming an uneven pattern on the surface of foamed wallpaper. This method applies a foam inhibitor onto the foam-containing resin layer in a pattern, and forms a patterned uneven pattern on the surface of the foam wallpaper by suppressing foaming of the applied part more than other parts. It is a method to do.

  Conventionally, in order to expand the variations of designs that can be expressed by the chemical embossing method, measures such as adding a matting agent to the foam inhibitor, and measures limiting the resin components constituting the foamed resin layer have been proposed (patents) References 1, 2).

  Specifically, in claim 1 of Patent Document 1, the foaming resin composition containing a foaming agent on a wallpaper substrate is used as a method for producing an uneven foam wallpaper having a glossy-matte effect. After the pattern is printed on the resin layer, the pattern is printed with a matte ink containing a foam inhibitor, with or without a gloss overprint layer on the entire surface, and then the foamable resin. A production method is described in which a layer of the composition is foamed to produce a foamed concavo-convex sheet having a matte effect as compared to a convex part in which a concave part in which foaming is suppressed is foamed.

  Moreover, in Claim 1 of patent document 2, it consists of a layer by the foaming agent containing resin layer on a base material, the ink which contains a foaming inhibitor on this, and the ink which does not contain a foaming inhibitor, and has surface unevenness by foaming In the chemically embossed decorative sheet, the foaming agent-containing resin layer has a foaming agent, a decomposition accelerator for the foaming agent, and a copolymerization ratio of 70 to 90% by weight of vinyl acetate and 10 to 30% by weight of ethylene. Mainly 40 to 90% by weight of vinyl copolymer and 10 to 60% by weight of acrylic ester resin having a minimum film forming temperature of 10 ° C. or lower and a glass transition temperature of −20 ° C. or higher and 10 ° C. or lower. A chemically embossed decorative sheet characterized by comprising a thermoplastic synthetic resin emulsion layer is described.

  The above-mentioned conventional chemical embossing method is useful and widely used, but development of a new chemical embossing method is desired in order to further increase design variations.

JP-A-4-86300 JP-A-9-174788

  The main object of the present invention is to provide a foamed wallpaper having a novel surface irregularity pattern formed by a novel chemical embossing method.

  As a result of intensive research, the inventor has formed an ionizing radiation curable resin layer in a pattern on the foaming agent-containing resin layer by a specific means, and then foamed the foaming agent-containing resin layer according to a specific chemical embossing method. The present inventors have found that the above object can be achieved, and have completed the present invention.

That is, this invention relates to the manufacturing method of the following foam wallpaper.
1. For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming the surface protective layer on the foaming agent-containing resin layer,
(3) Step 3 of forming the ionizing radiation curable resin layer by applying and curing an ionizing radiation curable resin containing a foaming inhibitor in a pattern on the outermost surface;
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order.
2. For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming the surface protective layer on the foaming agent-containing resin layer,
(3) After applying a foaming inhibitor in a pattern as a base to form a foaming inhibitor layer, the ionizing radiation curable resin is applied and cured on the outermost surface so as to follow the pattern. Step 3 of forming a resin layer,
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order.
3. For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming a pattern layer containing a foam inhibitor on the foam-containing resin layer in a pattern and forming the surface protective layer thereon,
(3) Step 3 of forming the ionizing radiation curable resin layer by applying and curing an ionizing radiation curable resin on the outermost surface so as to synchronize with the pattern of the pattern layer.
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order.
4). Item 4. The method for producing a foam wallpaper according to any one of Items 1 to 3, wherein the ionizing radiation curable resin contains urethane (meth) acrylate.
5. Item 5. The method for producing a foam wallpaper according to any one of Items 1 to 4, wherein, in the step 1, the foaming agent-containing resin layer is formed on the paper base material via a non-foamed resin layer B.
6). In the step 1, the non-foamed resin layer A is formed on the surface of the foaming agent-containing resin layer on the opposite side of the foaming agent-containing resin layer from the side on which the paper-based substrate is located. Item 6. A method for producing a foam wallpaper according to any one of Items 1 to 5.
7). Item 7. The method for producing a foam wallpaper according to any one of Items 1 to 6, wherein the ionizing radiation curable resin layer contains a gloss adjusting agent.
8). The said ionizing radiation curable resin layer is a manufacturing method of the foam wallpaper in any one of said claim | item 1-7 whose centerline average roughness Ra is 7 micrometers or less.

  Hereinafter, the foamed wallpaper of the present invention will be described in detail.

  The foamed wallpaper of the present invention has at least a foamed resin layer on a paper-based substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. The region where the ionizing radiation curable resin layer is formed with respect to the region is a recess.

  The foamed wallpaper of the present invention having the above-mentioned characteristics is obtained by applying or curing an ionizing radiation curable resin containing a foam inhibitor on the outermost surface before the foaming process in the process of producing foamed wallpaper, Or 2) After the ionizing radiation curable resin is applied and cured in a pattern through the foaming inhibitor layer, the region where the ionizing radiation curable resin is applied and cured in the foaming step is more than the other regions. It is obtained by forming a recess. This concave portion is formed when the region where the ionizing radiation curable resin is applied and cured in the foaming step is significantly recessed by the action of the foaming inhibitor. The ionizing radiation curable resin layer that has become a concave portion preferably has a smooth surface with a center line average roughness Ra of about 7 μm or less, so that it can be used as a high gloss design as it is, but the ionizing radiation curable resin layer is glossy. When the adjusting agent is contained, the gloss can be adjusted arbitrarily.

  Hereinafter, each requirement will be described separately.

The material of the paper base is not particularly limited as long as it has mechanical strength, heat resistance and the like suitable as a wallpaper base, and a fiber sheet can be generally used.

  Specifically, among fiber sheets, flame retardant paper (pulp-based sheets treated with flame retardants such as guanidine sulfamate and guanidine phosphate); inorganic additives such as aluminum hydroxide and magnesium hydroxide Inorganic paper including; fine paper; thin paper and the like.

The basis weight of the paper quality substrate is not limited, but preferably about 50 to 300 g / ^{m 2,} about 50 to 80 g / ^{m 2} is more preferable.

Non-foamed resin layer B
In the present invention, a non-foamed resin layer (non-foamed resin layer B) may be formed between the paper substrate and the foamed resin layer as necessary. In particular, when the non-foamed resin layer B is formed as an adhesive layer, excellent adhesion can be obtained. As the non-foamed resin layer B, for example, ethylene-vinyl acetate copolymer (EVA) or the like can be suitably used.

  The non-foamed resin layer B may contain known additives in addition to the resin component, but is preferably blended so that the content of the resin component is 70 to 100% by weight.

  The thickness of the non-foamed resin layer B is not limited, but is preferably about 5 to 50 μm, more preferably about 8 to 20 μm.

Foamed resin layer The foamed resin layer is generally formed by foaming a foaming agent-containing resin layer.

  The foaming agent-containing resin layer is not limited as long as it is foamed by the action of the foaming agent (for example, foamed when heated), but obtained from a combination of monomers such that the resin layer does not contain hydrogen bonds. It is preferable to use a resin that can be used. Therefore, for example, an ethylene copolymer resin obtained from a combination of ethylene and a monomer having no OH group or COOH group can be suitably used. From this viewpoint, examples of the ethylene copolymer resin include ethylene-vinyl acetate copolymer resin (hereinafter abbreviated as “EVA”), ethylene-methyl methacrylate (EMMA), ethylene-ethyl acrylate (EEA), ethylene-methyl. Acrylate (EMA) or the like can be used. In particular, it is desirable that the resin component is formed of a resin composition containing EVA resin. For example, a resin composition containing an EVA resin, a thermally decomposable foaming agent, an inorganic filler, a pigment, a foaming aid (zinc compound), and a cell regulator can be suitably used. In addition, stabilizers, lubricants and the like can be used as additives.

  When EVA resin is used as the resin component, the vinyl acetate content (copolymerization ratio) of the EVA resin is not limited, but is preferably about 5 to 30% by weight, more preferably about 10 to 20% by weight. .

  The melt flow rate value (MFR) of the resin component is not particularly limited, but is preferably about 5 to 75 g / 10 minutes, and more preferably about 10 to 30 g / 10 minutes.

  In addition, MFR of this specification is the value measured by the test method of JISK7210 (flow test method of thermoplastics). As test conditions, “190 ° C., 21.18 N (2.16 kgf)” described in JIS K 6760 is adopted.

  The foamed state of the foamed resin layer (for example, the size of foamed cells, the density of foamed cells, etc.) is not limited, and can be appropriately designed according to the type and use of the foamed wallpaper.

  The pyrolytic foaming agent can be selected from known foaming agents. For example, azo compounds such as azodicarbonamide (ADCA) and azobisformamide; and bidazides such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. The content of the pyrolytic foaming agent can be appropriately set according to the type of foaming agent, the expansion ratio, and the like. From the viewpoint of the expansion ratio, it is 1.5 times or more, preferably about 3 to 7 times, and the pyrolytic foaming agent is preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the resin component. .

  Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound. By including an inorganic filler, an effect of suppressing see-through, an effect of improving surface characteristics, and the like are obtained. About 0-100 weight part is preferable with respect to 100 weight part of resin components, and, as for content of an inorganic filler, about 20-70 weight part is more preferable.

  As for the pigment, for example, titanium oxide, zinc white, carbon black, black iron oxide, yellow iron oxide, yellow lead, molybdate orange, cadmium yellow, nickel titanium yellow, chrome titanium yellow, iron oxide (valve), cadmium red, Inorganic pigments such as ultramarine, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, zinc sulfide; for example, aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), many Cyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, perylene, diketopyrrolopyrrole, dibromanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone And organic pigments halogenated phthalocyanine), or the like. The content of the pigment is preferably about 10 to 50 parts by weight and more preferably about 15 to 30 parts by weight with respect to 100 parts by weight of the resin component.

  Examples of the foaming aid (zinc compound) include zinc oxide, hydroxide, carbonate, basic carbonate, sulfate, nitrate, phosphite, carboxylate and the like. Such a zinc compound is preferably added from the viewpoint of improving the foaming speed. Examples of the carboxylate include acetic acid, propionic acid, 2-ethylhexanoic acid, nonanoic acid, isononanoic acid, isodecanoic acid, neodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, Examples include aliphatic acids such as 12-hydroxystearic acid, ricinoleic acid, and behenic acid, and aromatic acids such as benzoic acid, p-tert-butylbenzoic acid, toluic acid, salicylic acid, and naphthenic acid. The zinc carboxylate using these carboxylic acids may be in the form of a normal salt, an acid salt, or a basic salt. The above-mentioned carboxylic acids constituting the zinc carboxylate can be used, but from the viewpoint of reducing VOC, those which are powders at room temperature using fatty acids having 12 or more carbon atoms, such as zinc stearate And zinc laurate are preferred. When other carboxylic acid is used, it may be liquid or may need to be dissolved in an organic solvent in order to improve handling properties.

  The content of the zinc compound is preferably about 0.001 to 20 parts by weight, more preferably about 0.001 to 10 parts by weight with respect to 100 parts by weight of the resin composition. The thickness of the foam layer is not limited, but is preferably 40 to 150 μm in an unfoamed state (before foaming). 300-900 micrometers is preferable after foaming.

  As the cell adjusting agent, for example, a metal soap such as zinc stearate can be used. The content of the cell modifier is preferably about 0.3 to 10 parts by weight and more preferably about 1 to 5 parts by weight with respect to 100 parts by weight of the resin component.

  What is necessary is just to implement according to the method described in the manufacturing method of the postscript as a method of foaming a foaming agent containing resin layer.

Non-foamed resin layer A
A non-foamed resin layer A may be further formed on the front surface of the foamed resin layer.

The non-foamed resin layer A mainly protects the foamed resin layer. In the present invention, a layer formed of a resin composition containing, as a resin component, a polymer obtained using at least one of acrylic acid (CH ₂ ═CHCOOH) and methacrylic acid (CH ₂ ═C (CH ₃ ) COOH) as a monomer. Is preferably a non-foamed resin layer.

  As the resin component, for example, a copolymer obtained by a combination of at least one monomer of acrylic acid and methacrylic acid and ethylene can be suitably used as the resin component. More specifically, it is desirable to use at least one of EMAA, ethylene-acrylic acid copolymer, and ionomer resin. As the ionomer resin, a resin having a structure in which EMAA and / or ethylene-acrylic acid copolymer molecules are intermolecularly bonded with metal ions such as sodium and zinc can be used. When such a resin component is used, it is possible to form a strong layer particularly due to hydrogen bonds in the resin, so that excellent scratch resistance, abrasion resistance, and the like can be obtained. These may be known or commercially available.

  The content of acrylic acid or methacrylic acid in the copolymer is not limited, but is preferably 15% by weight or less, more preferably about 4 to 15% by weight. Such a resin can also use a commercial item. A known additive can also be blended in the resin composition.

  The thickness of the non-foamed resin layer A is not limited, but is preferably about 5 to 50 μm, more preferably about 8 to 20 μm.

  Although the melt flow rate value of the resin component depends on the type of the resin component to be used, etc., it is generally set as appropriate within a range of 10 g / 10 min or more. Usually, it is preferably 10 to 100 g / 10 minutes, particularly preferably 10 to 95 g / 10 minutes, and more preferably 20 to 80 g / 10 minutes. By using a material having such a numerical range, more excellent scratch resistance, wear resistance and the like can be obtained.

  Moreover, although content of the said resin component in a resin composition is not limited, Usually, it is preferable to set suitably in the range of 70 to 100 weight%.

Pattern Pattern Layer In the present invention, a pattern pattern layer may be provided on the front surface of the non-foamed resin layer A as necessary.

  The pattern layer imparts design properties to the foamed wallpaper. Examples of the design pattern include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern. The pattern can be selected according to the type of foam wallpaper.

  The pattern pattern layer can be formed, for example, by printing a pattern pattern on the front surface of the non-foamed resin layer A. In addition, when forming a picture pattern layer, you may form a primer layer previously as needed. Examples of printing methods include gravure printing, flexographic printing, silk screen printing, and offset printing. As the printing ink, a printing ink containing a colorant, a binder resin, and a solvent (or a dispersion medium) can be used. These inks may be known or commercially available.

  As the colorant, for example, a pigment used in the above-described foaming agent-containing resin layer can be appropriately used.

  The binder resin is, for example, an acrylic resin, a styrene resin, a polyester resin, a urethane resin, a chlorinated polyolefin resin, a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, an alkyd resin, or a petroleum resin. Examples include resins, ketone resins, epoxy resins, melamine resins, fluorine resins, silicone resins, fiber derivatives, rubber resins, and the like.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene Chlorinated organic solvents; and water.

  The thickness of the design pattern layer is different from the type of design pattern, but is generally preferably about 0.1 to 10 μm.

Surface protective layer (overcoat layer)
In the present invention, a surface protective layer may be provided on the surface of the pattern layer. In particular, in the present invention, since the ionizing radiation curable resin layer on the outermost surface is formed in a pattern, the surface strength of the portion where the ionizing radiation curable resin layer is not formed (portion other than the pattern) is ensured. For this purpose, it is preferable to provide a surface protective layer.

  Although it does not limit as a surface protective layer, For example, it forms by apply | coating and hardening the composition containing a thermosetting resin, ionizing radiation curable resin, and the said resin. The ionizing radiation curable resin is preferably one that undergoes radical polymerization (curing) by electron beam irradiation. Examples of the thermosetting resin include acrylic resins, and examples of the ionizing radiation curable resin include urethane (meth) acrylate. In the case of a surface protective layer intended for gloss adjustment in addition to ensuring surface strength and the like, for example, a gloss adjusting agent such as silica may be added to the resin.

  As a method for forming the surface protective layer, a known method such as gravure printing can be employed. In addition, when the adhesiveness of a pattern pattern layer and a surface protective layer is not fully acquired, a surface protective layer can also be provided after carrying out the adhesion process (primer process) of the surface of a pattern pattern layer.

  The thickness of the surface protective layer is not limited, but is preferably about 0.1 to 15 μm.

Ionizing radiation curable resin layer formed into a pattern The foamed wallpaper of the present invention has an ionizing radiation curable resin layer formed in a pattern on the outermost surface. The layer in which the ionizing radiation curable resin layer is formed in a pattern is not particularly limited as long as it is a layer above the foamed resin layer. For example, the ionization radiation curable resin layer is ionized after a pattern layer and a surface protective layer are laminated on the foamed resin layer. An embodiment in which the radiation curable resin layer is formed in a pattern is exemplified.

  Examples of the pattern include, for example, a wood grain plate conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin finish, a grain, a hairline, and a multiline groove.

  The ionizing radiation curable resin layer (concave portion) in the form of a pattern is an ionizing radiation curable type containing 1) a foaming inhibitor on the outermost surface (for example, the surface of the surface protective layer) before the foaming step in the manufacturing process of the foam wallpaper. The resin is applied and cured in a pattern, or 2) After the ionizing radiation curable resin is applied and cured in a pattern via the foam inhibitor layer, the ionizing radiation curable resin is applied and cured in the foaming step. It is obtained when the hardened area becomes a recess rather than the other areas. This concave portion is formed when the region where the ionizing radiation curable resin is applied and cured in the foaming step is significantly recessed by the action of the foaming inhibitor. Specifically, it is formed by the foaming inhibitor component penetrating into the foaming agent-containing resin layer directly or through the other layer and being significantly dented from the other part by suppressing foaming of the permeation part. Is done.

  Examples of the foam inhibitor include trimellitic anhydride, 1- {N, N-bisalkylaminomethyl} benzotriazole compound, 1- {N, N-bis (hydroxyalkylene) aminomethyl} benzotriazole compound. Etc. These can be used alone or in combination of two or more. As the 1- {N, N-bisalkylaminomethyl} benzotriazole-based compound, for example, 1- {N, N-bis (2-ethylhexyl) aminomethyl} benzotriazole or a derivative thereof is preferable. As 1- {N, N-bis (hydroxyalkylene) aminomethyl} benzotriazole, for example, 1- {N, N-bis (hydroxyethylene) aminomethyl} benzotriazole or a derivative thereof is preferable.

  The foaming inhibitor may be used by mixing with an ionizing radiation curable resin (in the case of 1 above), and used as an undercoat in a shape along the pattern before the ionizing radiation curable resin is applied in a pattern. (In the case of 2 above). Specifically, in the case of 1) above, if the outermost surface before the foaming step is a surface protective layer, an ionizing radiation curable resin layer containing a foaming inhibitor is applied and cured in a pattern on the surface protective layer. You can do it. The mixing ratio of the ionizing radiation curable resin and the foaming inhibitor at this time is not limited, but usually the foaming inhibitor is preferably about 1 to 30 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin. About 15 parts by weight is more preferable.

  In the case of the above 2), when the outermost surface before the foaming step is a surface protective layer, a foam inhibitor is applied as a base pattern on the surface protective layer to form a foam inhibitor layer. The ionizing radiation curable resin may be applied and cured along In addition, by containing a foam inhibitor in the pattern layer, the pattern may be drawn in a shape along the pattern and used as an undercoat. In this case, the pattern pattern layer becomes a foaming inhibitor layer, and is formed in the order of, for example, “foaming inhibitor layer (pattern pattern layer) / surface protective layer / ionizing radiation curable resin layer”. It is formed so as to be synchronized with the pattern of the ionizing radiation curable resin layer. Here, the synchronization means that the pattern formation portion of the foaming inhibitor layer and the pattern formation portion of the ionizing radiation curable resin layer substantially coincide as shown in FIG. 2 (that is, both when viewed from the outermost surface). The pattern forming portion of the pattern is substantially overlapped).

  When undercoating the foam inhibitor, prepare a foam inhibitor-containing ink by appropriately adding a solvent such as methyl ethyl ketone or butyl acetate to the binder resin and the foam inhibitor, and apply by direct printing or transfer printing. That's fine. The content of the foam inhibitor in the foam inhibitor-containing ink is not limited, but is preferably about 1 to 40% by weight, more preferably about 5 to 30% by weight.

  When the pattern layer is used as the foam inhibitor layer, the foam inhibitor may be added to the printing ink described in the item of the pattern layer and the foam inhibitor-containing printing ink may be applied. The content of the foam inhibitor in the foam inhibitor-containing printing ink is not limited, but is preferably about 1 to 40% by weight, more preferably about 5 to 30% by weight. Also, by adjusting the content of the foaming inhibitor in the printing ink, or by applying multiple layers of printing ink as necessary, the amount of dent at the time of foaming of the synchronized ionizing radiation curable resin layer can be adjusted. Therefore, the design properties based on the unevenness can be adjusted.

  Further, if necessary, the uneven pattern can be further changed by adding a foaming inhibitor to a part of the region where the patterned ionizing radiation curable resin layer is not formed.

In the present invention, when the case 1) is compared with the case 2), the case 2) is preferable. In the case of the above 1) in which the foaming inhibitor is mixed with the ionizing radiation curable resin, if the addition amount of the foaming inhibitor is large, the ionizing radiation curable resin may be inhibited from crosslinking or the ionizing radiation curable resin layer. This is because the performance (contamination resistance, scratch resistance) may be reduced. Therefore, in the case of the above 1) in which the foaming inhibitor is mixed with the ionizing radiation curable resin, it is preferable to use a highly reactive prepolymer as the ionizing radiation curable resin.

  The ionizing radiation curable resin is not particularly limited, and prepolymers (including oligomers) and / or monomers containing radically polymerizable double bonds capable of undergoing a crosslinking reaction upon irradiation with ionizing radiation such as ultraviolet rays and electron beams. A transparent resin containing as a main component can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

  Specifically, as the prepolymer or monomer, a compound having in the molecule a radically polymerizable unsaturated group such as a (meth) acryloyl group or (meth) acryloyloxy group, or a cationically polymerizable functional group such as an epoxy group. Is mentioned. Further, a polyene / thiol prepolymer based on a combination of polyene and polythiol is also preferable. Here, the (meth) acryloyl group means an acryloyl group or a methacryloyl group.

  Examples of the prepolymer having a radically polymerizable unsaturated group include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, triazine (meth) acrylate, and silicone (meth) acrylate. Etc. These molecular weights are usually preferably about 250 to 100,000.

  As a monomer which has a radically polymerizable unsaturated group, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenoxyethyl (meth) acrylate etc. are mentioned as a monofunctional monomer, for example. Examples of the polyfunctional monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide tri (meth) acrylate, dipentaerythritol tetra ( And (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the prepolymer having a cationic polymerizable functional group include prepolymers of epoxy resins such as bisphenol type epoxy resins and novolac type epoxy compounds, and vinyl ether type resins such as fatty acid type vinyl ethers and aromatic vinyl ethers. Examples of the thiol include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate. Examples of the polyene include those in which allyl alcohol is added to both ends of polyurethane by diol and diisocyanate.

  In the present invention, since the foaming agent-containing resin layer is foamed after forming the patterned ionizing radiation curable resin layer, urethane (meth) acrylate having excellent flexibility and mechanical strength is used as the ionizing radiation curable resin. It is preferable to use it. Furthermore, since urethane (meth) acrylate has abundant types of polyol components that contribute to various physical properties such as flexibility, adhesion, and toughness, it gives various physical properties to wallpaper by properly using them depending on the application. be able to.

  The ionizing radiation curable resin may contain a crosslinking agent. Any crosslinking agent that promotes crosslinking by electron beam irradiation may be used. Examples thereof include polyfunctional monomers such as neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate, oligomers, and the like. The crosslinking agent is preferably about 0 to 10 parts by weight, more preferably 1 to 4 parts by weight, based on 100 parts by weight of the resin component.

  As the ionizing radiation used for curing the ionizing radiation curable resin, electromagnetic waves or charged particles having energy capable of causing a curing reaction of molecules in the ionizing radiation curable resin (composition) are used. Usually, ultraviolet rays or electron beams may be used, but visible light, X-rays, ion rays, or the like may be used.

  As the ultraviolet light source, for example, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light, a metal halide lamp can be used. As a wavelength of ultraviolet rays, 190 to 380 nm is usually preferable.

  As the electron beam source, for example, various electron beam accelerators such as a cockcroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. Among them, those capable of irradiating electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV are preferable.

  The patterned ionizing radiation curable resin layer serving as the concave portion has a depth of the concave portion (a difference in height from a region where the patterned ionizing radiation curable resin layer is not formed) of about 50 to 300 μm. This height difference can be appropriately adjusted according to the amount of the foam inhibitor used.

  In addition, the region where the patterned ionizing radiation curable resin layer is formed maintains a relatively smooth surface even after foaming. Therefore, if the center line average roughness Ra of the patterned ionizing radiation curable resin layer is preferably 7 μm or less, more preferably 5 μm or less, it can be used as it is as a high gloss design. Here, the patterned ionizing radiation curable resin layer has a smooth surface because it is difficult to pick up fine irregularities that occur on the surface of the foamed resin layer during foaming (it is difficult to be affected by fine irregularities), and is smooth before and after foaming. This is considered to be because the property can be maintained well.

  Furthermore, a gloss adjusting agent can be added to the ionizing radiation curable resin layer to arbitrarily adjust the gloss. Examples of the gloss adjusting agent include silica, alumina, calcium carbonate, talc, barium sulfate, and resin beads.

<Method for producing foam wallpaper>
For example, in order to produce a foamed wallpaper having a foamed resin layer and a non-foamed resin layer A on a paper-based substrate, coextrusion with a T-die extruder is suitable. A multi-manifold type T-die capable of simultaneously forming two layers by simultaneously extruding molten resin corresponding to two layers can be used. In this case, the resin composition for forming the foaming agent-containing resin layer and the resin composition for forming the non-foamed resin layer are placed in separate cylinders, and two types and two layers are simultaneously extruded to form and laminate. That's fine. In this method, the coextruded laminate is simultaneously laminated (film formation) on a paper-based substrate. The resin layer laminated simultaneously with extrusion on the paper base is bonded to the paper base because it has adhesiveness by heat melting.

  Alternatively, a laminate in which two types and two layers are simultaneously formed in advance may be prepared, placed on a paper substrate, and bonded to the paper substrate by heat lamination.

  In addition, when an inorganic filler is contained in the resin composition forming the foaming agent-containing resin layer, an inorganic filler residue (so-called eyes) is easily generated at the extrusion port (so-called die) of the extrusion molding machine. It tends to be a foreign material on the sheet surface. Therefore, in the case of this invention, it is preferable to coextrude the said non-foamed resin layer A and the non-foamed resin layer B with the foaming agent containing resin layer. The coextrusion molding can be performed, for example, by using a multi-manifold type T die. Thus, by simultaneously extruding and molding the foaming agent-containing resin layer between the non-foamed resin layers, it is possible to suppress the occurrence of the eyes.

  After simultaneous lamination on the paper substrate, after forming the pattern layer and surface protective layer as necessary, the ionizing radiation curable resin can be mixed with 1) foaming inhibitor and applied in a pattern. Or 2) It is applied and cured in a pattern through a foam inhibitor layer. Thereby, a patterned ionizing radiation curable resin layer is formed. In addition, about the formation method of a pattern pattern layer and a surface protective layer, it is as above-mentioned.

  When applying and curing an ionizing radiation curable resin (including the case of containing a foaming inhibitor) in a pattern, after applying the ionizing radiation curable resin in a pattern by a known application means, as described above What is necessary is just to harden a coating film by irradiating ionizing radiation.

  Next, the foamed resin layer is formed by heating the foaming agent-containing resin layer. The heating conditions are not limited as long as the foamed resin layer is formed by the decomposition of the pyrolytic foaming agent. The heating temperature is preferably about 210 to 240 ° C., and the heating time is preferably about 20 to 80 seconds.

  In the foaming step, the region where the ionizing radiation curable resin (including the case containing the foaming inhibitor) is coated and cured is significantly recessed as compared with other regions due to the action of the foaming inhibitor. The uneven pattern (chemical embossed uneven pattern) is formed.

  The foamed wallpaper of the present invention can be obtained by forming a region where the ionizing radiation curable resin is applied and cured to be a recess than other regions. Since the ionizing radiation curable resin layer that has become a recess has a smooth surface, it can be used as it is as a high-gloss design, but if the ionizing radiation curable resin layer contains a gloss adjusting agent, the gloss can be adjusted arbitrarily. This can be done, and variations in design expression can be increased.

It is a cross-sectional schematic diagram (upper figure: before foaming, lower figure: after foaming) of the foam wallpaper produced in Example 1. Among the pattern layers (7, 7 '), a schematic cross-sectional view of a foam wallpaper in which a foam inhibitor is added to the pattern layer (7') synchronized with the patterned ionizing radiation curable resin layer (upper figure: before foaming) The figure below is after foaming.

1. Backing paper2. Non-foamed resin layer B
3. Foaming agent-containing resin layer, 3 ′. 3. Foamed resin layer Non-foamed resin layer A
5. 5. Surface protective layer Patterned ionizing radiation curable resin layer (contains a foam inhibitor in FIG. 1 and does not contain a foam inhibitor in FIG. 2)
7). Design pattern layer (without foaming inhibitor), 7 '. Pattern pattern layer (including foam inhibitor)

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Example 1
Using a three-type, three-layer multi-manifold T-die extruder, on the substrate (backing paper) so that the thickness is 8 μm / 75 μm / 8 μm in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B The film was formed by extrusion. Thereby, the laminated body which consists of non-foaming resin layer A / foaming agent containing resin layer / non-foaming resin layer B / base material was obtained.

  As a base material, backing paper “WK-665 (manufactured by Kojin)” was prepared, heated to 90 ° C., and then the above three layers were extruded to form a film.

  Extrusion conditions were such that the cylinder temperature containing the resin for forming the non-foamed resin layer A was 140 ° C., the cylinder temperature containing the resin composition for forming the foaming agent-containing resin layer was 120 ° C., and non-foamed The cylinder temperature in which the resin for forming the resin layer B was accommodated was 100 ° C. The die temperature was 120 ° C. for all.

A surface protective layer (ALTOP-402B, manufactured by Dainippon Seika Co., Ltd., acrylic one-component curable resin) is printed on the non-foamed resin layer A of the laminate, and an ionization containing a urethane (meth) acrylate oligomer as the outermost layer. A radiation curable resin layer (coating amount of ionizing radiation curable resin itself: 6.0 g / m ² ) was provided in a pattern (hairline-like pattern). In addition, 30 parts by weight of ink (CE-X (23) medium, manufactured by The Inktec) containing trimellitic anhydride as a foaming inhibitor and 25 parts by weight of matte silica with respect to 100 parts by weight of ionizing radiation curable resin Were mixed and printed.

  Next, an electron beam (200 kV, 30 kGy) was irradiated from the ionizing radiation curable resin layer side to crosslink the foaming agent-containing resin layer and the ionizing radiation curable resin layer.

  Next, the laminate was heated in a foaming furnace (at 220 ° C. for 35 seconds) to foam the foaming agent-containing resin layer.

  Thereby, while forming the foamed resin layer, the uneven | corrugated pattern by chemical embossing was formed in the outermost surface, and the foaming wallpaper was obtained.

  Each layer was formed using the following components.

  The non-foamed resin layer A was formed by EMAA “Nucleel N1560 (MMA content: 15% by weight), manufactured by Mitsui DuPont Polychemical”.

  The foaming agent-containing resin layer is made of EVA “Evaflex V406 (VA content: 20 wt%, MFR = 20), made by Mitsui DuPont Polychemical” 100 parts by weight, flow modifier “P-100, made by Arakawa Chemical” 10 parts by weight, 20 parts by weight of titanium oxide “R103, manufactured by DuPont”, 5 parts by weight of ADCA foaming agent “Uniform Ultra AZ3050I manufactured by Otsuka Chemical”, and 5 parts by weight of foaming aid “OF-101, manufactured by ADEKA”.

  The non-foamed resin layer B was formed by EVA “Evaflex EV150 (VA content: 33 wt%, melting point: 61 ° C.), manufactured by Mitsui DuPont Polychemical”.

Example 2
A foamed wallpaper was produced in the same manner as in Example 1 except that the content of the matte silica contained in the ionizing radiation curable resin layer was 8 parts by weight.

Example 3
A foamed wallpaper was prepared in the same manner as in Example 1 except that the coating amount of the ionizing radiation curable resin itself was 2.5 g / m ² .

Example 4
A foam wallpaper was prepared in the same manner as in Example 2 except that the coating amount of the ionizing radiation curable resin itself was 2.5 g / m ² .

Example 5
The layer to which the foaming inhibitor is added is different from that in Example 1. In other words, a pattern layer (foaming inhibitor layer) is formed on the non-foamed resin layer A of the laminate by an ink (CE-X (23) medium, manufactured by The Inktech) containing trimellitic anhydride as a foaming inhibitor. It is formed into a pattern (hairline-like pattern), and further a surface protective layer (ALTOP-402B, manufactured by Dainichi Seika Co., Ltd., acrylic one-component curable resin) is printed, and a urethane (meth) acrylate oligomer is used as the outermost layer. A pattern (hairline-like pattern) is provided so that the ionizing radiation-curable resin layer (coating amount of the ionizing radiation-curable resin itself: 6.0 g / m ² ) is synchronized with the pattern layer (foaming inhibitor layer). It was. Note that 25 parts by weight of matte silica was mixed with 100 parts by weight of ionizing radiation curable resin for printing. Otherwise, a foamed wallpaper was prepared in the same manner as in Example 1.

Example 6
A foamed wallpaper was prepared in the same manner as in Example 5 except that the content of the matting silica was 8 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

Comparative Example 1
Using a three-type, three-layer multi-manifold T-die extruder, on the substrate (backing paper) so that the thickness is 8 μm / 75 μm / 8 μm in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B The film was formed by extrusion. Thereby, the laminated body which consists of non-foaming resin layer A / foaming agent containing resin layer / non-foaming resin layer B / base material was obtained.

  As a base material, backing paper “WK-665 (manufactured by Kojin)” was prepared, heated to 90 ° C., and then the above three layers were extruded to form a film.

  Extrusion conditions were such that the cylinder temperature containing the resin for forming the non-foamed resin layer A was 140 ° C., the cylinder temperature containing the resin composition for forming the foaming agent-containing resin layer was 120 ° C., and non-foamed The cylinder temperature in which the resin for forming the resin layer B was accommodated was 100 ° C. The die temperature was 120 ° C. for all.

  Next, an electron beam (200 kV, 30 kGy) was irradiated from the non-foamed resin layer A side to crosslink the foaming agent-containing resin layer.

  Next, a surface protective layer (ALTOP-402B, manufactured by Dainichi Seika Co., Ltd., acrylic one-component curable resin) is printed on the non-foamed resin layer A, and trimellitic anhydride (foaming inhibitor) is used as a pattern ink. The pattern was printed in a pattern (a hairline tone pattern) using an ink containing CE (CE-X (23) medium, manufactured by The Inktech).

  Next, the laminate was heated in a foaming furnace (at 220 ° C. for 35 seconds) to foam the foaming agent-containing resin layer.

  As a result, a foamed resin layer was formed, and a concavo-convex pattern by conventional chemical embossing was formed on the outermost surface to obtain a foamed wallpaper.

Comparative Example 2
A foamed wallpaper was prepared in the same manner as in Comparative Example 1 except that the order of forming the printed pattern with the surface protective layer and the pattern ink was reversed.

Test example 1 (gloss measurement)
The gloss of the produced foamed wallpaper was measured using a 60 ° gloss meter (GMX-202, manufactured by Murakami Color Research Laboratory). It shows in Table 1 with the evaluation result of the external appearance of foam wallpaper. In Table 1, * is given to the gloss value of the pattern portion (concave portion) on the outermost surface of the foam wallpaper.

["EB" in the table indicates an electron beam curable resin. ]
Test example 2 (surface roughness)
Using a surface roughness meter (surfcom120A, manufactured by Tokyo Seimitsu), the center line average roughness Ra of the produced foamed wallpaper was measured. The measurement results are shown in Table 2.

(Discussion)
In any of Examples 1 to 6 and Comparative Examples 1 and 2, foaming of the pattern portion was suppressed by the action of the foaming inhibitor, and an uneven pattern by chemical embossing could be formed. And it turns out that uneven | corrugated height difference can be suitably adjusted according to content (foaming amount in Examples 1-4) of a foaming inhibitor. According to the result of Table 2, in Examples 1-6, since the pattern part of the outermost surface is formed with ionizing radiation curable resin, compared with Comparative Examples 1-2, the smoothness after foaming is very high. If Ra is 7 μm or less, it can be used as it is as a high gloss design, but it can be seen that the gloss can be adjusted arbitrarily by adjusting the content of the gloss adjuster.

Claims (8)

For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming the surface protective layer on the foaming agent-containing resin layer,
(3) Step 3 of forming the ionizing radiation curable resin layer by applying and curing an ionizing radiation curable resin containing a foaming inhibitor in a pattern on the outermost surface;
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order. For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming the surface protective layer on the foaming agent-containing resin layer,
(3) After applying a foaming inhibitor in a pattern as a base to form a foaming inhibitor layer, the ionizing radiation curable resin is applied and cured on the outermost surface so as to follow the pattern. Step 3 of forming a resin layer,
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order. For a region where the foamed resin layer and the surface protective layer are provided on the paper substrate, the ionizing radiation curable resin layer is formed in a pattern on the outermost surface, and the ionizing radiation curable resin layer is not formed. A method for producing a foam wallpaper in which the region where the ionizing radiation curable resin layer is formed is a recess,
(1) Step 1 of forming at least a foaming agent-containing resin layer on the paper substrate;
(2) Step 2 of forming a pattern layer containing a foam inhibitor on the foam-containing resin layer in a pattern and forming the surface protective layer thereon,
(3) Step 3 of forming the ionizing radiation curable resin layer by applying and curing an ionizing radiation curable resin on the outermost surface so as to synchronize with the pattern of the pattern layer.
(4) Step 4 of forming the foamed resin layer by heating the foaming agent-containing resin layer;
In order.   The said ionizing radiation curable resin is a manufacturing method of the foam wallpaper in any one of Claims 1-3 containing urethane (meth) acrylate.   5. The method for producing a foam wallpaper according to claim 1, wherein in the step 1, the foaming agent-containing resin layer is formed on the paper base material via a non-foamed resin layer B. 6.   In the step 1, the non-foamed resin layer A is formed on the surface of the foaming agent-containing resin layer on the opposite side of the foaming agent-containing resin layer from the side on which the paper base is located. Item 6. A method for producing a foam wallpaper according to any one of Items 1 to 5.   The foaming wallpaper manufacturing method according to claim 1, wherein the ionizing radiation curable resin layer contains a gloss adjusting agent.   The said ionizing radiation curable resin layer is a manufacturing method of the foam wallpaper in any one of Claims 1-7 whose centerline average roughness Ra is 7 micrometers or less.

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