JP2007090841A - Foamed wallpaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide foamed wallpaper which has an excellent fouling resistance and surface strength, can hide the unevenness of a substrate in applying the wallpaper, and at the same time, can reduce or eliminate problems wherein creases and curls occur sometimes. <P>SOLUTION: The foamed wallpaper is characterized in that after two layers of an unfoamed resin layer and a surface protection layer both consisting of a non-halogen thermoplastic resin are co-extruded on a paper base material to be laminated, the unfoamed resin layer is heated to form a foamed resin layer, and an embossed-pattern is formed by embossing the surface protection layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a foam wallpaper having excellent stain resistance.

  Conventionally, foamed wallpaper in which a foamed resin layer of vinyl chloride resin is formed on a paper base material is known. In recent years, in consideration of the environment, a resin not containing halogen such as an olefin resin typified by an acrylic resin and an ethylene-vinyl acetate copolymer has been used for the foamed resin layer (for example, Patent Documents 1 to 3). 3).

  For example, a foamed resin composition in which a microcapsule type foaming agent is added to an emulsion containing an acrylic resin and an ethylene-vinyl acetate copolymer is applied to a paper substrate and dried, and then a pattern is printed on the surface. There is known a foamed wallpaper obtained by heating and foaming and forming an uneven pattern with an embossed plate. Also, a foamed resin composition obtained by adding a thermally decomposable foaming agent to an ethylene-vinyl acetate copolymer is extruded on a paper substrate using a T-die extruder, a pattern is printed on the surface, and then heated. A foamed wallpaper is known which is foamed and has an uneven pattern formed by an embossed plate. Since these olefin-based foamed wallpapers have low surface strength, they need to be reinforced. As the method, for example, 1) a method of keeping the foaming ratio of the foamed resin layer low, or 2) a method of providing a film layer or a thick coating film on the foamed resin layer, etc. are proposed.

  The above method 1) has a problem that the background unevenness cannot be concealed during wallpaper construction, and the above method 2) is usually widely adopted (see, for example, Patent Documents 4 and 5). The technique disclosed in Patent Document 4 uses a film excellent in stain resistance such as an ethylene-vinyl alcohol copolymer film as a surface protective layer provided on the foamed resin layer, thereby providing a pattern provided on the foamed resin layer. The foamed resin layer protects the printed layer and reinforces the surface strength. However, the foamed resin layer is a film having excellent antifouling property as the surface protective layer, and the problem that the foamed wallpaper itself is hard and creases are likely to occur. There is a problem that curling is likely to occur due to lamination on the top, or an increase in production man-hours for laminating a film having excellent stain resistance on the foamed resin layer, which in turn increases costs.

The inventor eliminates the pattern printing layer provided on the foamed resin layer or the like, and does not significantly deteriorate the stain resistance without providing the surface protective layer, and from the specific resin on the foamed resin layer. The present inventors have found that an excellent surface strength can be obtained by employing the surface protective layer.
Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A JP-A-8-309903 Japanese Patent Laid-Open No. 11-48414

  Therefore, the present invention is to provide a foam wallpaper excellent in stain resistance and surface strength, and can also conceal the uneven surface of the ground when constructing the wallpaper and reduce the problem of creases and curls. It is to provide a foam wallpaper that can be eliminated.

  In order to achieve the above object, the inventor of the present invention provides the foamed wallpaper of the present invention according to claim 1 on a paper substrate, an unfoamed resin layer and a surface protective layer, both of which are made of a non-halogen thermoplastic resin. After the two layers are coextruded and laminated, the unfoamed resin layer is heated and foamed to form a foamed resin layer, and an uneven pattern is formed by embossing from the surface protective layer. Is.

  Further, the foamed wallpaper of the present invention according to claim 2 is obtained by coextruding only three layers of an adhesive layer, an unfoamed resin layer, and a surface protective layer, all of which are made of a non-halogen thermoplastic resin, on a paper substrate. Then, the unfoamed resin layer is heated and foamed to form a foamed resin layer, and an uneven pattern is formed by embossing from the surface protective layer.

  Further, in the present invention according to claim 3, in the foamed wallpaper according to any one of claims 1 and 2, the surface protective layer is made of a synthetic resin obtained using at least one of acrylic acid and methacrylic acid as a monomer. It is characterized by.

  Further, the present invention according to claim 4 is the foamed wallpaper according to claim 3, wherein the synthetic resin is a copolymer obtained by a combination of at least one monomer of acrylic acid and methacrylic acid and ethylene. It is a feature.

  Moreover, the present invention according to claim 5 is the foam wallpaper according to claim 3, wherein the synthetic resin is at least one of an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, and an ionomer resin. It is characterized by this.

  The foamed wallpaper of the present invention eliminates the pattern printing layer and adopts a surface protective layer made of a specific resin on the foamed resin layer, thereby providing an effect of excellent stain resistance and surface strength. In addition to being able to conceal the unevenness of the ground at times, it is possible to reduce or eliminate the problem of creases and curls.

The above-described present invention will be described in detail below with reference to the drawings.
FIG. 1 is a layer configuration diagram schematically illustrating one embodiment of the foam wallpaper according to the present invention, and FIG. 2 is a layer configuration diagram schematically illustrating another embodiment of the foam wallpaper according to the present invention. 1, 1 'are foamed wallpaper, 2 is a paper substrate, 3 is an adhesive layer, 4 is a foamed resin layer, 5 is a surface protective layer, and 6 is an uneven pattern.

  FIG. 1 is a layer configuration diagram schematically showing an embodiment of a foam wallpaper according to the present invention. The foam wallpaper 1 is an unfoamed resin made of a non-halogen thermoplastic resin on a paper substrate 2. After layering only two layers and the surface protective layer 5 by coextrusion, the unfoamed resin layer is heated and foamed to form a foamed resin layer 4, and irregularities are formed from the surface protective layer 5 side to the foamed resin layer 4. A pattern 6 is formed.

  FIG. 2 is a layer configuration diagram schematically showing another embodiment of the foamed wallpaper according to the present invention. The foamed wallpaper 1 ′ is bonded to the paper base material 2 and both are made of a non-halogen thermoplastic resin. After laminating only the layer 3, the unfoamed resin layer and the surface protective layer 5 by coextrusion and laminating, the unfoamed resin layer is heated and foamed to form the foamed resin layer 4, from the surface protective layer 5 side. An uneven pattern 6 is formed over the foamed resin layer 4.

As the paper base 2, a pulp-based flame retardant paper impregnated with a water-soluble flame retardant such as guanidine sulfamate or guanidine phosphate, or an inorganic agent such as magnesium carbonate, aluminum hydroxide or magnesium hydroxide is mixed. What is said to be a normal backing paper for wallpaper such as inorganic paper can be used, and its basis weight is 50 to 300 g / m ² , preferably 70 to 160 g / m ² , but is not limited thereto. It is not a thing.

Next, the non-halogen thermoplastic resin that forms the adhesive layer 3, the foamed resin layer 4, and the surface protective layer 5 will be described. First, the non-halogen thermoplastic resin forming the surface protective layer 5 will be described. The non-halogen thermoplastic resin forming the surface protective layer 5 is a synthetic resin obtained using at least one of acrylic acid [CH ₂ = CHCOOH] and methacrylic acid [CH ₂ = C (CH ₃ ) COOH] as a monomer. For example, a copolymer obtained by combining ethylene with at least one monomer of acrylic acid and methacrylic acid can be suitably used. Specifically, at least one of an ethylene-methacrylic acid copolymer (EMAA resin), an ethylene-acrylic acid copolymer (EAA resin), and an ionomer resin can be used. Among these, particularly when processing at a low temperature, it is preferable to use an ethylene- (meth) acrylic acid copolymer (EMAA resin, EAA resin), which forms a strong layer due to hydrogen bonding or the like in the resin. Therefore, excellent scratch resistance, wear resistance and the like can be obtained.

  In addition, as the non-halogen thermoplastic resin forming the adhesive layer 3 and the foamed resin layer 4, the resin described in the surface protective layer 5 can be preferably used, but in consideration of cost, ethylene-vinyl acetate is used. A copolymer (EVA resin) is suitable.

  Next, the foaming agent and inorganic filler added to the non-halogen thermoplastic resin forming the foamed resin layer 4 will be described. First, as the foaming agent, a thermal expansion capsule foaming agent containing a low-boiling point hydrocarbon can be used, but it is low in cost and has a small amount of heat of decomposition, is excellent in flame retardancy and self-extinguishing properties, and is nontoxic. From the point that flame retardancy can be imparted to the foamed resin layer 4, azo series such as azodicarbonamide and azobisformamide, or hydrazide series such as oxybenzenesulfonyl hydrazide and paratoluenesulfonyl hydrazide, etc. Pyrolytic foaming agents are preferred. The content of the pyrolytic foaming agent is appropriately designed 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 thermally decomposable foaming agent is 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, barium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, antimony trioxide, zinc borate, a molybdenum compound, and talc. By including the inorganic filler, it is possible to obtain a see-through suppressing effect, a surface property improving effect, and the like. An inorganic filler is 0-100 weight part with respect to 100 weight part of resin components, Preferably it is 20-70 weight part.

  The foamed resin layer 4 may be colored by adding a pigment or the like as necessary. The coloring by adding the pigment may be transparent, translucent, or opaque. For example, inorganic pigments such as titanium dioxide, iron oxide, carbon black, aniline black, phthalocyanine Organic pigments such as blue can be mentioned, and the amount of the pigment added is 10 to 50 parts by weight, preferably 15 to 30 parts by weight with respect to 100 parts by weight of the resin component. Moreover, well-known additives, such as a flame retardant, a cell regulator, a stabilizer, and a lubricant, can be used for the foamed resin layer 4.

  Further, the surface of the paper base 2 on the side of the foamed resin layer 4 is subjected to, for example, easy adhesion treatment such as corona discharge treatment, plasma treatment, ozone treatment, and / or acrylic-butyl copolymer, isocyanate and An easy adhesion treatment layer coated with polyurethane or the like made of polyol may be provided.

  Next, the uneven pattern 6 will be described. The concavo-convex pattern 6 can be obtained by utilizing the heat generated when heated and foamed to form the foamed resin layer 4 by setting the surface protective layer 5 side as a cooling embossing roll and the paper base material 2 side as a rubber roll. A concavo-convex pattern 6 is formed on the surface by being nipped (embossed) by two rolls and cooled. Examples of the concavo-convex pattern 6 include a wood grain plate conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin finish, a grain, a hairline, and a multi-row groove.

  The foamed wallpaper 1, 1 'of the present invention may be irradiated with an electron beam from the surface protective layer 5 side before being heated and foamed. Thereby, since resin of each layer can be bridge | crosslinked, the surface strength at the time of setting it as a foam wallpaper, a foaming degree, etc. can be controlled. The energy of the electron beam is suitably about 150 to 250 kV. Moreover, about 10-100 kGy is suitable for an irradiation amount. As the electron beam source, a known electron beam irradiation device may be used.

  Moreover, when performing electron beam irradiation, you may add a crosslinking adjuvant to resin of each layer. Any crosslinking assistant may be used as long as it promotes crosslinking by electron beam irradiation, and examples thereof include polyfunctional monomers such as neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate, oligomers, and the like. . The crosslinking aid is about 0 to 10 parts by weight, preferably 1 to 4 parts by weight with respect to 100 parts by weight of the resin.

  Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples, and includes all categories that do not depart from the gist of the present invention.

  A resin composition for forming a surface protective layer having a formulation shown in Table 1 on a paper base [made by Hokuetsu Paper Co., Ltd .: HPT-65 (trade name)] and a foamed resin composition and a table having a formulation shown in Table 2 After the resin forming the adhesive layer shown in 3 is heated and melt-extruded to a thickness of 10 μm / 100 μm / 10 μm using a three-type three-layer multi-manifold T-die extruder, an electron beam (175 kV, 3 Mrad) is applied to the resin surface. An unfoamed intermediate wallpaper [paper base material / adhesive layer 10 μm / unfoamed resin layer (foamed resin composition) 100 μm / surface protective layer 10 μm] was prepared by irradiating and cross-linking each layer. The intermediate wallpaper was heated at 220 ° C. for 30 seconds to heat and foam the foamed resin composition, and a textured pattern was embossed to produce a foamed wallpaper of the present invention.

[Comparative Example 1]
The surface protective layer surface of the intermediate wallpaper of Example 1 was subjected to corona discharge treatment, and an ethylene-vinyl acetate copolymer (hereinafter referred to as EVA resin) aqueous emulsion was applied to the corona discharge treatment surface by a gravure printing method. After providing a printing primer layer (2 g / m ² dry) and printing a texture pattern on the surface of the printing primer layer using water-based ink, the foamed resin composition is heated and foamed by heating at 220 ° C. for 30 seconds. A foamed wallpaper as a comparative example was prepared by embossing the texture pattern with unevenness.

  Contamination resistance of the foamed wallpaper of Example 1 and Comparative Example 1 produced above was evaluated by the evaluation method described below, and the evaluation results are summarized in Table 4.

[Contamination resistance evaluation method]
Draw a 10 cm long straight line with oily magic on the surface of the foamed wallpaper, wipe it with a cloth impregnated with ethanol 3 minutes later, and show that the straight line drawn with oily magic has been wiped off as good, and mark that cannot be wiped off As shown in FIG.

  As can be seen from Table 4, the foamed wallpaper of Example 1 was excellent in stain resistance as compared with Comparative Example 1. .

It is a layer block diagram which shows one Example of the foam wallpaper concerning this invention schematically. It is a layer block diagram which shows the other Example of the foam wallpaper concerning this invention schematically.

Explanation of symbols

1,1 'foam wallpaper 2 paper substrate 3 adhesive layer 4 foam resin layer 5 surface protective layer 6 uneven pattern

Claims (5)

Foaming is carried out by heating and foaming the unfoamed resin layer after co-extruding and laminating only two unfoamed resin layers and a surface protective layer, both of which are made of a non-halogen thermoplastic resin, on a paper substrate. A foamed wallpaper comprising a resin layer and an uneven pattern formed on the surface protective layer by embossing. On the paper base material, after laminating only three layers of an adhesive layer made of a non-halogen thermoplastic resin, an unfoamed resin layer, and a surface protective layer, the unfoamed resin layer is heated and foamed. A foamed wallpaper having a foamed resin layer and an uneven pattern formed on the surface protective layer by embossing. The foamed wallpaper according to any one of claims 1 and 2, wherein the surface protective layer is made of a synthetic resin obtained using at least one of acrylic acid and methacrylic acid as a monomer. The foamed wallpaper according to claim 3, wherein the synthetic resin is a copolymer obtained by a combination of at least one monomer of acrylic acid and methacrylic acid and ethylene. The foamed wallpaper according to claim 3, wherein the synthetic resin is at least one of an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, and an ionomer resin.

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