JP5617820B2 - Foam wallpaper - Google Patents

Description

  The present invention relates to foamed wallpaper useful for wall decoration.

  Conventionally, foamed wallpaper (foamed decorative sheet) is known in which a foamed resin layer of vinyl chloride resin is formed on a paper-based substrate (backing paper). In recent years, in consideration of the environment, resins that do not contain halogen such as ethylene-vinyl acetate copolymer resin (EVA), acrylic resin, and olefin resin have been used for the foamed resin layer (Patent Document 1). ~ 3 etc.).

  The foamed wallpaper is generally obtained by forming a foaming agent-containing resin layer on a paper base and then foaming the foaming agent-containing resin layer by heating. The foaming agent-containing resin layer often contains an inorganic component such as an inorganic filler.

  When the content of the inorganic component contained in the foaming agent-containing resin layer is set to be large, the content of the resin component can be relatively reduced, so that the cost of the foam wallpaper can be reduced. In addition, the addition of an inorganic component can improve the surface strength and suppress the see-through effect.

  However, when the content of the inorganic component is large (for example, 100 parts by weight or more of the inorganic component with respect to 100 parts by weight of the resin component), the surface state of the foamed resin layer obtained after foaming and the shape of the foamed cell are unsatisfactory. It becomes uniform and cannot maintain sufficient quality.

  Therefore, even when the foaming agent-containing resin layer contains 100 parts by weight or more of the inorganic component with respect to 100 parts by weight of the resin component, there is a need for technical development to maintain the surface state of the foamed resin layer and the shape of the foamed cell. ing. The ratio of the resin component and the inorganic component in the foaming agent-containing resin layer is substantially the same in the foamed resin layer obtained after foaming.

Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A

  In the present invention, even when the foaming agent-containing resin layer contains 100 parts by weight or more of the inorganic component with respect to 100 parts by weight of the resin component, the foamed resin layer has a good surface state and foamed cell shape obtained after foaming. The main purpose is to provide wallpaper.

  As a result of intensive studies, the present inventors have found that the above object can be achieved when a specific resin component is contained in the foaming agent-containing resin layer, and the present invention has been completed.

That is, the present invention relates to the following foamed wallpaper.
1. A foam wallpaper having at least one resin layer laminated on a paper substrate and having a foam resin layer on the outermost surface thereof,
(1) The foamed resin layer is formed by foaming a foaming agent-containing resin layer,
(2) the blowing agent-containing resin layer, an ethylene - the inorganic component comprises from 100 to 140 parts by weight containing the vinyl acetate copolymer 100 parts by weight,
(3) The ethylene-vinyl acetate copolymer has a melt flow rate of 9 to 15 g / 10 minutes and a vinyl acetate content of 10 to 14% by weight.
Foam wallpaper characterized by that.
2. Item 2. The foamed wallpaper according to Item 1, wherein the foaming agent-containing resin layer contains talc as an inorganic component.
3. Item 3. The foamed wallpaper according to Item 1 or 2, wherein the foaming agent-containing resin layer is foamed by heating at 210 to 240 ° C for 30 to 50 seconds.
4). The foaming wallpaper according to any one of Items 1 to 3, wherein the foaming agent-containing resin layer is irradiated with an electron beam of 40 to 60 kGy prior to foaming.
5. Item 5. The foamed wallpaper according to any one of Items 1 to 4, wherein a non-foamed resin layer B is further formed between the paper substrate and the foamed resin layer.
6). Item 6. The foamed wallpaper according to any one of Items 1 to 5, wherein embossing is performed on the outermost surface layer.

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

The foamed wallpaper of the present invention is a foamed wallpaper having at least a foamed resin layer on a paper-based substrate,
(1) The foamed resin layer is formed by foaming a foaming agent-containing resin layer,
(2) The foaming agent-containing resin layer contains 100 parts by weight or more of an inorganic component with respect to 100 parts by weight of a resin component containing an ethylene copolymer,
(3) The ethylene copolymer has a melt flow rate of 1 to 15 g / 10 min and a content of copolymer components other than ethylene of 1 to 14% by weight.

  The foamed wallpaper of the present invention having the above characteristics employs a resin component containing a specific ethylene copolymer in the foaming agent-containing resin layer, and therefore contains 100 parts by weight or more of an inorganic component with respect to 100 parts by weight of the resin component. Even so, the surface state and foamed cell shape of the foamed resin layer obtained after foaming are good. Such a foamed wallpaper of the present invention uses a relatively small amount of resin component and is advantageous from the viewpoint of manufacturing cost. Moreover, the physical property improvement effect by the mixing | blending of an inorganic component is easy to be acquired.

  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 10 to 50 μm, more preferably about 10 to 20 μm.

Foamed resin layer The foamed resin layer is formed by foaming a foaming agent-containing resin layer. The foaming agent used in the present invention is preferably a pyrolytic foaming agent. In this case, the foaming agent-containing resin layer is foamed by heating to become a foamed resin layer.

  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 is set according to the type of foaming agent and the foaming ratio. 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. .

  In this invention, a specific ethylene copolymer is contained as a resin component contained in a foaming agent containing resin layer. Examples of the ethylene copolymer include ethylene-vinyl acetate copolymer resin (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl acrylate copolymer. (EMA) or the like can be used. Among the above, EVA is preferable from the viewpoint of cost. These ethylene copolymers can be used alone or in admixture of two or more.

  As the ethylene copolymer, one having a melt flow rate value (MFR) of 1 to 15 g / 10 min is used. Among these, the thing of 9-15 g / 10min is preferable. 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.

  Moreover, as said ethylene copolymer, the content (namely, copolymerization ratio) of copolymerization components other than ethylene uses 1 to 14 weight%. Among these, the thing of 10 to 14 weight% is preferable.

  By using the specific ethylene copolymer as a resin component, even when the content of the inorganic component contained in the foaming agent-containing resin layer is large, the surface state and foamed cell shape of the foamed resin layer obtained after foaming are good. Retained. In addition, although it is desirable that the resin component is substantially composed of the ethylene copolymer, other resins can be used in combination as long as the effects of the present invention are not affected.

  In this invention, a foaming agent containing resin layer contains 100 weight part or more of inorganic components with respect to 100 weight part of resin components. Although the upper limit of an inorganic component is not limited, about 140 weight part is preferable and about 120 weight part is more preferable.

  Examples of the inorganic component mainly include inorganic fillers (so-called inorganic fillers). Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound. By including these inorganic fillers, an effect of suppressing see-through and an effect of improving the surface strength can be obtained.

  In addition, the foaming agent-containing resin layer may contain a pigment or an additive. In addition, what remains as an inorganic component in the foamed resin layer after foaming considers content as said inorganic component, even if it is except an inorganic filler.

As for pigments, 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, bituminous, 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), Polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthro Is an organic pigment of a halogenated phthalocyanine), or the like.

  Examples of the additive include a cell regulator and a stabilizer. Examples of the cell conditioner include metal soaps such as zinc stearate.

  About content of the said pigment and additive, it sets according to a desired coloring grade and an addition effect.

  Details of the method of foaming the foaming agent-containing resin layer will be described later.

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 (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 is not limited, but is preferably about 10 to 50 μm, more preferably about 10 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 design pattern layer for the purpose of adjusting the gloss and / or protecting the design 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 (such as scratch resistance) of foamed wallpaper, 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.

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

Embossing In this invention, you may attach | subject an embossing pattern suitably. In this case, embossing may be performed on the outermost surface layer (the side opposite to the paper-based substrate) of the foam wallpaper. Embossing can be performed by known means such as pressing an embossed plate. For example, when the outermost surface layer is a surface protective layer, 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, in order to produce a foamed wallpaper having a foamed resin layer and a non-foamed resin layer A on a paper 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, 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 200 to 250 ° C, more preferably about 210 to 240 ° C. The heating time is preferably about 20 to 60 seconds, and more preferably about 30 to 50 seconds.

  Electron beam irradiation may be performed before the heat treatment. Thereby, since the resin component can be crosslinked, the surface strength of the foamed wallpaper, the degree of foaming, etc. can be controlled. The energy of the electron beam is preferably about 150 to 250 kV. The irradiation dose is preferably about 10 to 70 kGy, more preferably about 40 to 60 kGy. A known electron beam irradiation apparatus can be used as the electron beam source. Crosslinking can also be performed using a chemical crosslinking agent (also referred to as a crosslinking agent or a crosslinking aid).

  In the case of performing electron beam irradiation, the composition 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.

  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 non-foaming resin layer, a pattern layer, and a surface protective layer containing an ionizing radiation curable resin in this order, the resin contained in the foaming agent-containing resin layer is irradiated with an electron beam. The resin contained in the surface protective layer can be cured while being crosslinked.

  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.

  Since the foamed wallpaper of the present invention employs a resin component containing a specific ethylene copolymer in the foaming agent-containing resin layer, even if it contains 100 parts by weight or more of the inorganic component with respect to 100 parts by weight of the resin component The surface state of the foamed resin layer obtained after foaming and the foamed cell shape are good. Such a foamed wallpaper of the present invention uses a relatively small amount of resin component and is advantageous from the viewpoint of manufacturing cost. Moreover, the physical property improvement effect by the mixing | blending of an inorganic component is easy to be acquired.

  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.

Examples 1-2 and Comparative Examples 1-4
Six types of foamed wallpaper were produced by forming a foamed resin layer from a resin composition shown in Table 1 on a paper-based substrate (product number “WK665DO”, manufactured by Kojin, thickness 110 μm).

In Table 1, the types and physical properties of EVA are as follows.
(A): Product name “EV550”, MFR = 15 g / 10 min, VA content = 14 wt%
(B): Product name “P1007”, MFR = 9 g / 10 min, VA content = 10 wt%
(C): Product name “V406”, MFR = 20 g / 10 min, VA content = 20 wt%
(D): Product name “EV150”, MFR = 30 g / 10 min, VA content = 33 wt%
(E): Product name “EV250”, MFR = 15 g / 10 min, VA content = 28 wt%
(F): Product name “EV410”, MFR = 400 g / 10 min, VA content = 19 wt%
The EVA of Comparative Example 4 is a mixture of 70 parts by weight of (E) and 30 parts by weight of (F), MFR = 40.2 g / 10 minutes, and VA content = 25% by weight.

  The foam wallpaper was produced by the following procedure.

  First, each component was kneaded as described above to prepare pellets. As an apparatus, the product name "Polylab system" and the product made by HAKKE were used. The kneading conditions were kneading time: 10 min, screw rotation speed: 50 rpm, kneading temperature: 100 ° C.

The prepared pellets were hot pressed to form a sheet. The press conditions were a press time: 10 sec, a press temperature: 100 ° C., and a press load: 10 kgf / cm ² (conditions for the sheet thickness to be 140 to 150 μm).

The sheet was pressed against a paper substrate by hot pressing. The pressure bonding conditions were a pressure bonding time: 10 sec, a pressure bonding temperature: 100 ° C., and a pressure bonding load: 10 kgf / cm ² (conditions in which the sheet thickness including the paper-based substrate is 190 to 200 μm).

  The resin surface of the original fabric sample produced above was irradiated with an electron beam. Irradiation conditions were acceleration voltage: 200 kV, beam current: 4.1 mA, and irradiation amount: 50 kGy.

  Finally, it was heated and foamed at 220 ° C. for 45 seconds in a gear oven.

Cell Evaluation of Foamed Resin Layer The cell state was evaluated by observing the surface of the foamed resin layer with the naked eye.

  Specifically, the cell expands on the surface of the foamed resin layer (a blister-like swell, which occurs when the gas generated by thermal decomposition has a gas pressure exceeding the critical point of the melt tension of the resin. Evaluation was made based on whether or not the resin layer surface smoothness was impaired. As the evaluation criteria, a case where the occurrence rate of swelling on the surface of the foamed resin layer was 0 to less than 10% was evaluated as “◯”, a case where it was 10% or more and less than 50%, and a case where it was 50% or more.

  The evaluation results are shown in Table 2 below.

Claims (6)

A foam wallpaper having at least one resin layer laminated on a paper substrate and having a foam resin layer on the outermost surface thereof,
(1) The foamed resin layer is formed by foaming a foaming agent-containing resin layer,
(2) the blowing agent-containing resin layer, an ethylene - the inorganic component comprises from 100 to 140 parts by weight containing the vinyl acetate copolymer 100 parts by weight,
(3) The ethylene-vinyl acetate copolymer has a melt flow rate of 9 to 15 g / 10 minutes and a vinyl acetate content of 10 to 14% by weight.
Foam wallpaper characterized by that.   The foaming wallpaper of Claim 1 in which the said foaming agent containing resin layer contains a talc as an inorganic component.   The foaming wallpaper according to claim 1 or 2, wherein the foaming agent-containing resin layer is foamed by heating at 210 to 240 ° C for 30 to 50 seconds.   The foaming wallpaper according to any one of claims 1 to 3, wherein the foaming agent-containing resin layer is irradiated with an electron beam of 40 to 60 kGy prior to foaming.   The foamed wallpaper according to any one of claims 1 to 4, wherein a non-foamed resin layer B is further formed between the paper-based substrate and the foamed resin layer.   The foamed wallpaper according to any one of claims 1 to 5, wherein embossing is performed on the outermost surface layer.