JP2007291598A - Foamed wall paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide foamed wall paper containing both ethylene-methacrylic acid copolymer and ethylene-α-olefin copolymer and having good surface strength and applicability. <P>SOLUTION: This foamed wall paper prepared by laminating a foamed resin layer and a non-foamed resin layer 1 to a paper substrate is characterized in that at least one of the foamed resin layer and the non-foamed resin layer 1 contains the ethylene-methacrylic acid copolymer and the ethylene-α-olefin copolymer as resin components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to foam wallpaper.

  Conventionally, foamed wallpaper is known in which a foamed resin layer containing a vinyl chloride resin as a resin component is laminated on a paper-based substrate. In recent years, in consideration of the environment, there is also a laminate in which a foamed resin layer containing a resin containing no halogen such as an ethylene-vinyl acetate copolymer (EVA), an acrylic resin, and an olefin resin is laminated (Patent Literature). 1-3).

  Foamed wallpaper requires surface strength (especially scratch resistance). For this reason, in recent years, a surface protective layer that is a non-foamed resin layer is often provided on the front surface of the foamed resin layer. As the surface protective layer, a non-foamed resin layer containing an ethylene-methacrylic acid copolymer (EMAA) advantageous for surface strength as a resin component is known. In addition, EMAA may be used as a resin component contained in the foamed resin layer in anticipation of further surface strength of the foam wallpaper.

  However, when EMAA is used as the resin component, there are the following problems. In the case of containing EMAA, it is advantageous for expression of surface strength, but the flexibility of the foamed wallpaper is lowered, so that the foamed wallpaper is strong and the workability is lowered. In particular, when the construction target includes a corner or a curved portion, the workability is likely to be reduced.

In view of this problem, development of foam wallpaper having good surface strength and workability is desired.
Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A

  An object of the present invention is to provide a foam wallpaper having good surface strength and workability.

  As a result of intensive studies, the inventor has improved the workability without impairing the surface strength when the resin layer containing EMAA as a resin component further contains a specific component. The inventors have found that this can be achieved and have completed the present invention.

  That is, the present invention relates to the following foamed wallpaper.

  1. A foamed wallpaper in which a foamed resin layer and a non-foamed resin layer 1 are sequentially laminated on a paper-based substrate, wherein at least one of the foamed resin layer and the non-foamed resin layer 1 has an ethylene-methacrylic acid copolymer as a resin component A foamed wallpaper comprising a coalescence and an ethylene-α-olefin copolymer.

  2. Item 3. The foamed wallpaper according to Item 1 or 2, wherein the ethylene-α-olefin copolymer is contained in the resin component in an amount of 20 to 50% by weight.

  3. Item 3. The foamed wallpaper according to Item 1 or 2, further comprising a non-foamed resin layer 2 between the paper substrate and the foamed resin layer.

4). Item 4. The foamed wallpaper according to any one of Items 1 to 3, wherein the surface is embossed.

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

  The foamed wallpaper of the present invention is a foamed wallpaper in which a foamed resin layer and a non-foamed resin layer 1 are sequentially laminated on a paper base material, and at least one of the foamed resin layer and the non-foamed resin layer 1 is a resin component As an ethylene-methacrylic acid copolymer (EMAA) and an ethylene-α-olefin copolymer.

  The foamed wallpaper of the present invention having the above characteristics has good surface strength because at least one of the foamed resin layer and the non-foamed resin layer 1 contains EMAA. In particular, since the non-foamed resin layer 1 has a role as a surface protective layer, when the non-foamed resin layer 1 contains EMAA, it is easy to improve the surface characteristics. In addition, since the foamed wallpaper of the present invention further contains an ethylene-α-olefin copolymer in the layer containing EMAA, the flexibility of the layer containing EMAA is improved without impairing the surface strength characteristics based on EMAA. ing. That is, since the stiffness of the foamed wallpaper is moderated, it is easy to construct even if the construction object includes corners and curved portions. That is, the foamed wallpaper of the present invention also has good workability while maintaining good surface strength based on containing EMAA.

  Hereinafter, the foamed wallpaper of the present invention will be described for each layer.

The paper-based substrate is not particularly limited as long as it has mechanical strength, heat resistance and the like suitable as a wallpaper substrate, and a fibrous 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.

Foamed resin layer The foamed resin layer is a layer that imparts cushioning properties to the foamed wallpaper, and usually occupies most of the thickness of the foamed wallpaper. The foamed resin layer may contain additives such as inorganic fillers, pigments, and crosslinking aids in addition to the resin component, and such a foamed resin layer is formed by foaming the foaming agent-containing resin layer. Is preferred.

  The foaming agent-containing resin layer includes a resin component, a foaming agent, other additives, and the like. Although it is not limited as a resin component, For example, ethylene copolymer resin is preferable. Among these, when the foaming agent-containing resin layer is formed by melt extrusion, melt extrusion is possible at a relatively low temperature, and foaming of the foaming agent in the machine (for example, abnormal foaming in the cylinder of the extruder) can be suppressed. From the viewpoint, an ethylene-vinyl acetate copolymer (EVA) is preferable. Moreover, EMAA can be used individually or in a mixed aspect with other resin as a resin component.

  When EMAA is contained as a resin component, the flexibility of the foamed resin layer may be reduced and workability may be reduced. Therefore, in order to improve flexibility, it is preferable to further contain an ethylene-α olefin copolymer as a resin component. Examples of the α olefin include propylene, butene, hexene, octene, 4-methylpentene and the like. When the ethylene-α-olefin copolymer is thus contained, the content of the ethylene-α-olefin copolymer is about 20 to 50% by weight in the resin component in the foaming agent-containing resin layer (foamed resin layer). Preferably, about 30 to 40% by weight is more preferable.

  As the foaming agent, a pyrolytic foaming agent is preferable. Examples of the thermally decomposable foaming agent include azo series such as azodicarbonamide (ADCA) and azobisformamide; and hydrazide series such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. The content of the pyrolytic foaming agent can be adjusted according to the expansion ratio and the like. Usually, about 1-20 weight part is preferable with respect to 100 weight part of resin components in a foaming agent containing resin layer.

  Examples of other additives include inorganic fillers, pigments, cell regulators, and crosslinking aids.

  Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound.

  Examples of the pigment include the following. Inorganic pigments include, 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), and cadmium. Examples thereof include red, ultramarine blue, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, and zinc sulfide. Examples of organic pigments include aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, Perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halogenated phthalocyanine) and the like.

  Examples of the cell regulator include metal soaps and zinc compounds.

  Examples of the crosslinking aid include acrylic monomers. As addition amount of a crosslinking adjuvant, about 0-10 weight part is preferable with respect to 100 weight part of resin components in a foaming agent containing resin layer, and 1-4 weight part is more preferable.

  Although the thickness of a foaming agent containing resin layer is not limited, About 10-200 micrometers is preferable.

  The foamed resin layer is obtained by foaming the foaming agent-containing resin layer. Thermally decomposable foaming agents decompose and foam when heated. The heating condition is not limited as long as it is equal to or higher than the decomposition temperature of the pyrolytic foaming agent. The heating temperature is preferably about 200 to 300 ° C., and the heating time is preferably about 10 to 40 seconds. For heating, a known foaming furnace or the like can be used. The expansion ratio of the foamed resin layer with respect to the foaming agent-containing resin layer is about 4 to 10 times.

  The foamed resin layer may be resin crosslinked alone or together with the non-foamed resin layer described later. Examples of the resin crosslinking means include electron beam irradiation. By cross-linking the resin, the surface strength of the foam wallpaper can be adjusted, and the expansion ratio can be adjusted.

  The foamed resin layer may be directly laminated on the paper base, or may be laminated via a non-foamed resin layer 2 (adhesive layer) described later.

Non-foamed resin layer 1
The non-foamed resin layer 1 has a role as a surface protective layer. Therefore, a layer that imparts excellent surface strength to the foamed wallpaper is desirable.

The resin component of the non-foamed resin layer 1 is not limited, but a polymer obtained by using at least one of acrylic acid (CH ₂ = CHCOOH) and methacrylic acid (CH ₂ = C (CH ₃ ) COOH) as a monomer is used. It is preferable to use a resin component.

  As the resin component, for example, a copolymer obtained by combining at least one of acrylic acid and methacrylic acid with a monomer and ethylene can be suitably used as the resin component. More specifically, it is desirable to use at least one of ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer, and ionomer resin. When such a resin component is used, an excellent surface strength (such as scratch resistance) can be obtained because a strong layer caused by hydrogen bonds or the like in the resin can be formed. These may be known or commercially available.

  The content of acrylic acid or methacrylic acid in the copolymer is preferably about 4 to 15% by weight. Such a resin can also use a commercial item.

  In the present invention, it is particularly desirable to contain EMAA as the resin component of the non-foamed resin layer 1, and it is also preferable to contain an ethylene-α-olefin copolymer at the same time. With such a formulation, excellent surface strength can be obtained based on the inclusion of EMAA, and the flexibility of the layer can also be obtained by the combined use of the ethylene-α-olefin copolymer. In order to improve flexibility while maintaining excellent surface strength, the content of the ethylene-α-olefin copolymer is preferably about 20 to 50% by weight in the resin component of the non-foamed resin layer 1, and 30 to About 40% by weight is preferable. When the content of the ethylene-α-olefin copolymer exceeds 50% by weight in the resin component of the non-foamed resin layer 1, the surface strength of the non-foamed resin layer 1 may be reduced. In addition, as a resin component, two components of EMAA and an ethylene-alpha olefin copolymer may be sufficient.

  The thickness of the non-foamed resin layer 1 is not limited, but is preferably about 5 to 30 μm, and preferably about 10 to 15 μm.

Non-foamed resin layer 2 (adhesive layer)
In the present invention, a non-foamed resin layer (non-foamed resin layer 2) may be formed between the paper base and the foamed resin layer as necessary. In particular, when the non-foamed resin layer 2 is formed as an adhesive layer, excellent adhesion can be obtained. Although the resin component contained in the non-foamed resin layer 2 is not limited, EVA is preferable from the viewpoint of improving the adhesion. The non-foamed resin layer 2 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 2 is not limited, but is preferably about 5 to 30 μm, and preferably about 10 to 15 μm.

Pattern Pattern Layer The foamed wallpaper of the present invention may have a pattern pattern layer on the front surface of the non-foamed resin layer 1 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. Examples of printing methods include gravure printing, flexographic printing, silk screen printing, offset printing, and the like. As the printing ink, a printing ink containing a colorant, a binder resin, and a solvent 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 can be set according to the type of the base sheet. For example, acrylic resin, styrene resin, polyester resin, urethane resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, alkyd resin, petroleum resin, ketone resin, epoxy Resin, melamine resin, fluorine resin, silicone resin, fiber derivative, rubber resin 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 foamed wallpaper of the present invention, a further surface protective layer may be formed on the surface of the pattern layer for the purpose of adjusting the gloss and / or protecting the pattern layer. The kind of surface protective layer is not limited. If it is a surface protective layer aiming at gloss adjustment, there exists a surface protective layer containing known fillers, such as a silica, for example. 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.

  When forming a surface protective layer for the purpose of surface strength of foamed wallpaper (scratch resistance, etc.), stain resistance, protection of the pattern layer, etc., those containing ionizing radiation curable resins as resin components are suitable. is there. The ionizing radiation curable resin is preferably one that undergoes radical polymerization (curing) by electron beam irradiation.

  When a surface protective layer containing an ionizing radiation curable resin is formed, the surface protective layer can be cured by electron beam irradiation. Such electron beam irradiation can be performed simultaneously (same processing) as electron beam irradiation performed to crosslink the resin contained in the foaming agent-containing resin layer. That is, after forming a foaming agent-containing resin layer, a pattern layer and a surface protective layer containing an ionizing radiation curable resin in order, electron beam irradiation is performed to crosslink the resin contained in the foaming agent-containing resin layer and protect the surface. The resin contained in the layer can be cured.

  The thickness of the surface protective layer is different from the pattern type, but is preferably about 0.1 to 15 μm.

The embossed invention sheet may be embossed from its front surface. Embossing can be performed by known means such as an embossed plate. For example, when the outermost surface layer is the non-foamed resin layer 1, a desired embossed pattern can be formed by pressing the embossed plate after heat-softening the front surface. Examples of the embossed pattern include a wood grain plate conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin texture, a grain texture, a hairline, and a multiline groove.

Method for producing foam wallpaper The method for producing the foam wallpaper is not particularly limited. For example, co-extrusion with a T-die extruder is suitable. For example, when the foamed wallpaper is a paper-based substrate in which a foamed resin layer and a non-foamed resin layer 1 are formed in this order, two layers can be formed simultaneously by extruding molten resin corresponding to the two layers. A multi-manifold type T-die capable of forming a film 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 1 are placed in separate cylinders, and two types and two layers are simultaneously extruded to form and laminate. do it. 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, and the foaming agent-containing resin layer is formed by extrusion molding, an extrusion port (so-called die) of an extrusion molding machine is used. Inorganic filler residues (so-called eyes and eyes) are likely to occur, and this tends to be a foreign matter on the sheet surface. Therefore, when an inorganic filler is contained in the resin composition forming the foaming agent-containing resin layer, the non-foaming resin layer 1 and the non-foaming resin layer 2 can be coextruded together with the foaming agent-containing resin layer. preferable. 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, the foaming agent-containing resin layer is irradiated with an electron beam. Since the resin component can be cross-linked and the radically polymerizable material can be radically polymerized (cured), the surface strength of the wall covering decorative sheet, the degree of foaming, and the like can be controlled. The energy of the electron beam is preferably about 150 to 250 kV, more preferably about 175 to 200 kV. The irradiation amount is preferably about 10 to 100 kGy, and more preferably about 10 to 30 kGy. A known electron beam irradiation apparatus can be used as the electron beam source. Next, the foamed resin layer is formed by heating the foaming agent-containing resin layer. The heating conditions are as described above.

  When producing a foam wallpaper having a pattern layer, it is preferable to form the pattern layer on the surface of the non-foamed resin layer before the heat treatment. The pattern pattern layer may be formed as described above.

  The foamed wallpaper of the present invention has good surface strength because at least one of the foamed resin layer and the non-foamed resin layer 1 contains EMAA. In particular, since the non-foamed resin layer 1 has a role as a surface protective layer, when the non-foamed resin layer 1 contains EMAA, it is easy to improve the surface characteristics. Moreover, since the foamed wallpaper of the present invention further contains an ethylene-α-olefin copolymer in the layer containing EMAA, the surface strength characteristics based on EMAA are not inhibited, and the flexibility of the layer containing EMAA is improved. ing. That is, since the stiffness of the foamed wallpaper is moderated, it is easy to construct even if the construction object includes corners and curved portions. That is, the foamed wallpaper of the present invention also has good workability while maintaining good surface strength based on containing EMAA.

Examples 1-5 and Comparative Examples 1-3
A resin composition for forming a foaming agent-containing resin layer was prepared by mixing a resin component, an inorganic filler, a pigment, a pyrolytic foaming agent, a cell adjusting agent, and a crosslinking aid. Table 1 shows the blending ratio of each component.

  A resin composition for forming the non-foamed resin layer 1 by mixing EMAA and an ethylene-α-olefin copolymer was prepared. The blending ratio of each component is shown in Table 2 divided into Examples and Comparative Examples. The thickness of the non-foamed resin layer 1 is also shown in Table 2.

  The composition was melt-extruded on a base paper (HPT-65 Hokuetsu Paper Manufacturing Co., Ltd.) using a T-die extruder, and a foaming agent-containing resin layer and a non-foamed resin layer 1 were laminated.

  The resin sheet was irradiated with an electron beam (irradiation amount: 30 kGy) to crosslink the resin. Next, after forming a pattern layer on the surface of the resin sheet, heating and foaming were performed by heating at 220 ° C. for 30 seconds. The thickness of the foamed resin layer was 90 μm. An uneven pattern was further provided on the resin sheet side by embossing.

  Through the above process, a foam wallpaper was prepared.

Test example 1
About the foaming wallpaper produced in Examples 1-5 and Comparative Examples 1-3, surface strength (abrasion resistance) and workability were evaluated.

  The scratch resistance was evaluated based on a test (surface strengthening test) in the surface enhancement product performance display according to the standards of the Japan Wallcovering Association. Evaluation is grade 5 when there is no change, grade 4 when the surface is slightly changed, grade 3 when the surface is broken and the resin layer and the foamed layer are visible, and surface is broken and the base material layer is visible (length) Less than 1 cm) was graded 2, and the surface was broken and the substrate layer was visible (length 1 cm or more) was graded 1.

  About workability, the wallpaper craftsman was made to stick a foam wallpaper to all of a plane part, a corner | angular part, and a curved part, and workability was evaluated. In accordance with JIS A6921, the evaluation was evaluated as “Good” when the workability was good, and “Poor” when the workability was poor.

  The evaluation results are shown in Table 3 below.

Examples 6 to 10 and Comparative Examples 4 to 6
A resin composition for forming a foaming agent-containing resin layer was prepared by mixing a resin component, an inorganic filler, a pigment, a pyrolytic foaming agent, a cell adjusting agent, and a crosslinking aid. Table 4 shows the blending ratio of each component.

  A resin composition for forming the non-foamed resin layer 1 by mixing EMAA and an ethylene-α-olefin copolymer was prepared. The blending ratio of each component is shown in Table 5 separately for Examples and Comparative Examples. The thickness of the non-foamed resin layer 1 is also shown in Table 5.

  The composition was melt-extruded on a base paper (HPT-65 Hokuetsu Paper Manufacturing Co., Ltd.) using a T-die extruder, and a foaming agent-containing resin layer and a non-foamed resin layer 1 were laminated.

  The resin sheet was irradiated with an electron beam (irradiation amount: 30 kGy) to crosslink the resin. Next, after forming a pattern layer on the surface of the resin sheet, heating and foaming were performed by heating at 220 ° C. for 30 seconds. The thickness of the foamed resin layer was 90 μm. An uneven pattern was further provided on the resin sheet side by embossing.

  Through the above process, a foam wallpaper was prepared.

Test example 2
About the foaming wallpaper produced in Examples 6-10 and Comparative Examples 4-6, surface strength (abrasion resistance) and workability were evaluated. The evaluation method and evaluation criteria are the same as in Test Example 1.

  The evaluation results are shown in Table 6 below.

Claims (4)

  A foamed wallpaper in which a foamed resin layer and a non-foamed resin layer 1 are sequentially laminated on a paper-based substrate, wherein at least one of the foamed resin layer and the non-foamed resin layer 1 has an ethylene-methacrylic acid copolymer as a resin component A foamed wallpaper comprising a coalescence and an ethylene-α-olefin copolymer.   The foamed wallpaper according to claim 1 or 2, wherein the ethylene-α-olefin copolymer is contained in the resin component in an amount of 20 to 50% by weight.   The foamed wallpaper according to claim 1 or 2, further comprising a non-foamed resin layer 2 between the paper-based substrate and the foamed resin layer.   The foamed wallpaper according to any one of claims 1 to 3, wherein the surface is embossed.