JP5974783B2 - Laminated sheet and foam laminated sheet - Google Patents

Description

  The present invention relates to a laminated sheet and a foam laminated sheet. The foamed laminated sheet has a foamed resin layer and is useful as foamed wallpaper, various decorative materials, and the like. Moreover, the said laminated sheet means the state (what is called an unfoamed raw material) before foaming of the said foaming laminated sheet.

  Conventionally, a foamed decorative sheet or the like in which at least a foamed resin layer is formed on a paper-based substrate is known. In such a foam decorative sheet, the foamed resin layer is formed by foaming the foaming agent-containing resin layer. For such a foaming agent-containing resin layer, an ethylene copolymer is used from the viewpoint of flexibility and processing characteristics, and in particular, the foamed resin layer formed by foaming the foaming agent-containing resin layer requires strength. In such a case, an ethylene- (meth) acrylic acid copolymer is used (see, for example, Patent Documents 1 and 2).

  In the present specification, “(meth) acryl” means acryl or methacryl, and the same applies to other similar portions.

  However, when an ethylene- (meth) acrylic acid copolymer is used as a resin for forming the foaming agent-containing resin layer, if the foaming resin layer is formed by foaming the foaming agent-containing resin layer, the resin has sufficient foaming gas. There was a problem that the foamed cells of the foamed resin layer would be broken.

  Moreover, in the aspect which forms a film layer etc. on a foamed resin layer, a bubble may be produced between the said film layer etc. and a foamed resin layer. When embossing is performed from above the outermost surface layer of the foamed laminated sheet in such a state, there is a problem that the film is broken by the pressure of bubbles, so-called puncture occurs. This problem is particularly remarkable when the foaming ratio of the foamed resin layer is high.

  Therefore, even when an ethylene- (meth) acrylic acid copolymer is used to form a foaming agent-containing resin layer, the foam retention of the foamed resin layer is excellent due to excellent foam retention of the foamed resin layer. And development of the new laminated sheet and the foamed laminated sheet in which generation | occurrence | production of the puncture at the time of embossing from the uppermost surface layer of a foamed laminated sheet was suppressed is calculated | required.

JP 2011-093302 A JP 2007-046207 A

  The present invention has excellent retention of foam in the foamed resin layer and suppresses the occurrence of foam breakage in the foamed cell of the foamed resin layer and the occurrence of puncture when embossing is performed from the top surface layer of the foamed laminated sheet. It is an object to provide a laminated sheet and a foamed laminated sheet.

  As a result of intensive studies to achieve the above object, the present inventor has found that, in a laminated sheet in which at least a foaming agent-containing resin layer is laminated on a fibrous sheet, the foaming agent-containing resin layer is ethylene- (meta ) It has been found that the above object can be achieved by the constitution containing an acrylic acid copolymer and a nonpolar polyolefin wax, and the present invention has been completed.

That is, the present invention relates to the following laminated sheet and foamed laminated sheet.
1. A laminated sheet in which at least a foaming agent-containing resin layer is laminated on a fibrous sheet,
The foaming agent-containing resin layer contains an ethylene- (meth) acrylic acid copolymer and a nonpolar polyolefin wax.
2. The laminated sheet according to Item 1, wherein the nonpolar polyolefin wax is a nonoxidized polyethylene wax.
3. The laminated sheet according to Item 1 or 2, wherein the content of the nonpolar polyolefin wax is 0.5 to 10 parts by mass with respect to 100 parts by mass of the ethylene- (meth) acrylic acid copolymer.
4). Item 4. The laminated sheet according to any one of Items 1 to 3, wherein the foaming agent-containing resin layer has a non-foamed resin layer on one side or both sides.
5. Item 5. The laminated sheet according to any one of Items 1 to 4, further comprising a pattern layer on the foaming agent-containing resin layer.
6). Item 6. The laminated sheet according to any one of Items 1 to 5, which has a film layer on the foaming agent-containing resin layer.
7). Item 7. The laminated sheet according to any one of Items 1 to 6, which has a surface protective layer made of an ionizing radiation curable resin on the outermost surface.
8). Item 8. The laminated sheet according to any one of Items 1 to 7, wherein the foaming agent-containing resin layer is resin-crosslinked by electron beam irradiation.
9. The foaming lamination sheet obtained by foaming the said foaming agent containing resin layer of the lamination sheet in any one of said item | item 1-8, and setting it as a foaming resin layer.
10. Item 10. The foamed laminated sheet according to Item 9, wherein the foaming resin layer has a foaming ratio of 8 times or more.
11 Item 11. The foamed laminated sheet according to Item 9 or 10, which is embossed from above the outermost surface layer.

Hereinafter, the laminated sheet, the foamed laminated sheet and the production method thereof of the present invention will be described in detail.
≪Laminated sheet≫
The laminated sheet of the present invention is a laminated sheet in which at least a foaming agent-containing resin layer is laminated on a fibrous sheet, and the foaming agent-containing resin layer comprises an ethylene- (meth) acrylic acid copolymer, and It contains a nonpolar polyolefin wax.

  The laminated sheet of the present invention having the above characteristics uses an ethylene- (meth) acrylic acid copolymer as a resin for forming the foaming agent-containing resin layer by containing the nonpolar polyolefin wax in the foaming agent-containing resin layer. Nevertheless, the foamed resin layer obtained by foaming the foaming agent-containing resin layer is excellent in the retention of bubbles, the occurrence of foam breakage in the foamed cell of the foamed resin layer, and the outermost surface layer of the foamed laminated sheet Occurrence of puncture when embossing is performed from above is suppressed.

Fibrous sheet Fibrous sheet (so-called backing paper) includes general paper for wallpaper (pulp-based sheet sized with a known sizing agent); flame retardant paper (pulp-based sheet guanidine sulfamate, phosphoric acid) Treated with a flame retardant such as guanidine); inorganic paper containing inorganic additives such as aluminum hydroxide and magnesium hydroxide; fine paper; thin paper; fiber mixed paper (paper made by mixing pulp and synthetic fiber) ) And the like.

Although the basis weight of the fibrous sheet is not critical, preferably about 50 to 300 g / ^{m 2,} about 50 to 120 / ^{m 2} is more preferable.

Foaming agent-containing resin layer In the laminated sheet of the present invention, at least a foaming agent-containing resin layer is laminated on a fibrous sheet. This foaming agent-containing resin layer can be formed by a known film forming method such as a T-die film forming method or a calendar film forming method.

  The said foaming agent containing resin layer contains ethylene- (meth) acrylic acid copolymer (EAA or EMAA) as a resin component. The ethylene- (meth) acrylic acid copolymer is suitable for extrusion film formation from the viewpoint of the melting point and MFR, and can impart strength to the foaming agent-containing resin layer and the foamed resin layer obtained by foaming this. it can.

  The ethylene- (meth) acrylic acid copolymer has a (meth) acrylic acid copolymerization ratio (AA amount or MAA amount) of preferably 2 to 15% by mass, more preferably 5 to 11% by mass. By adopting such a copolymerization ratio, the extrusion film forming property is further enhanced.

  The content of the ethylene- (meth) acrylic acid copolymer in the resin component in the resin composition forming the foaming agent-containing resin layer is preferably 90% by mass or more, and 95% by mass or more, with the resin component being 100% by mass. Is more preferable.

  Moreover, the said foaming agent containing resin layer contains nonpolar polyolefin wax as a resin component.

  The nonpolar polyolefin wax is not particularly limited as long as it is a polyolefin resin having no polarity. Examples of the nonpolar polyolefin wax include nonoxidized polyethylene wax and nonoxidized polypropylene wax. Among these, non-oxidized polyethylene wax is preferably used because it has a melting point lower than the kneading temperature when kneading the resin component and is easy to knead.

  The content of the nonpolar polyolefin wax is preferably 0.5 to 10 parts by mass, and 1.0 to 5.0 parts by mass with respect to 100 parts by mass of the ethylene- (meth) acrylic acid copolymer. It is more preferable that If the content of the nonpolar polyolefin wax is too large, the effect may be saturated and the economy may be inferior, and the resin composition forming the foaming agent-containing resin layer may be too soft to make it difficult to form the foamed resin layer. There is. Moreover, when there is too little content of nonpolar polyolefin wax, there exists a possibility that the effect by containing nonpolar polyolefin wax may become inadequate.

  Further, in the present invention, the resin component contained in the foaming agent-containing resin layer is dependent on the MFR (melt flow) measured under the conditions of 190 ° C. and a load of 21.18 N described in JIS K 6922, depending on the film forming method. The rate is preferably 10 to 35 g / 10 min. When the MFR is within the above range, there is little increase in temperature when the foaming agent-containing resin layer is formed by extrusion film formation, and the film can be formed in a non-foamed state. It can be printed on any surface and there are few patterns missing. If the MFR is too large, the resin is too soft, and the resulting foaming agent-containing resin layer may have insufficient scratch resistance.

  The laminated sheet of the present invention is a so-called raw fabric having a foaming agent-containing resin layer. The foamed laminate sheet of the present invention is obtained by foaming the foaming agent-containing resin layer.

  As the resin composition for forming the foaming agent-containing resin layer, for example, a resin composition containing the above resin component, inorganic filler, pigment, pyrolytic foaming agent, foaming aid, crosslinking aid and the like can be suitably used. . In addition, a stabilizer or the like can be used as an additive.

  Examples of the thermally decomposable foaming agent include azo series such as azodicarbonamide (ADCA) and azobisformamide; hydrazide series 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 8 times or more, preferably about 8 to 10 times, and the pyrolytic foaming agent is preferably about 1 to 20 parts by mass with respect to 100 parts by mass of the resin component. The laminated sheet of the present invention has a configuration in which the foaming agent-containing resin layer contains a nonpolar polyolefin wax, so that the foamed resin layer can be used even when the foaming ratio of the foamed resin layer is set to the above high range. It is possible to suppress the occurrence of foam breakage in the foamed cell of the foamed resin layer and the occurrence of puncture when embossing is performed from the top surface layer of the foamed laminated sheet. .

  When ADCA is used as the foaming agent, the foaming aid is generally preferably a metal oxide and / or a fatty acid metal salt, such as zinc stearate, calcium stearate, magnesium stearate, zinc octylate, calcium octylate. It is said that magnesium octylate, zinc laurate, calcium laurate, magnesium laurate, zinc oxide, magnesium oxide and the like can be used. However, since the foamed resin layer forming the laminated sheet of the present invention contains an ethylene- (meth) acrylic acid copolymer, the (meth) acrylic acid of the ethylene- (meth) acrylic acid copolymer is used in the foaming step. The effect as a foaming aid may be impaired by the reaction between the part and the metal-based foaming aid. Therefore, when an ethylene- (meth) acrylic acid copolymer and an ADCA foaming agent are used in combination, a carboxylic acid hydrazide compound is used as a foaming aid as described in JP-A-2009-197219. Is preferred. At this time, it is preferable to use about 0.2-1 mass part of carboxylic acid hydrazide compounds with respect to 1 mass part of ADCA foaming agent.

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

  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, ultramarine, 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). About 10-50 mass parts is preferable with respect to 100 mass parts of resin components, and, as for content of a pigment, about 15-30 mass parts is more preferable.

  In the present invention, the foaming agent-containing resin layer may be resin-crosslinked by electron beam irradiation. What is necessary is just to implement according to the method described in the postscript manufacturing method as a method of irradiating an electron beam to a foaming agent containing resin layer, and the method of making it foam.

  In the present invention, the foaming agent-containing resin layer may be a layer that forms a pattern separately from the pattern layer described later. The pigments and resins used are the same as those that can be used in the pattern layer described later.

  The thickness of the foaming agent-containing resin layer is preferably about 40 to 200 μm, and the thickness of the foamed resin layer after foaming in the case of the foaming agent-containing resin layer is preferably about 300 to 1500 μm.

Non-foamed resin layers A and B
The foaming agent-containing resin layer may have a non-foamed resin layer on one side or both sides.

  For example, the back surface (surface on which the fibrous sheet is laminated) of the foaming agent-containing resin layer may have a non-foamed resin layer B (adhesive resin layer) for the purpose of improving the adhesive strength with the fibrous sheet. .

  The resin component of the adhesive resin layer is not particularly limited, but an ethylene-vinyl acetate copolymer (EVA) is preferable. EVA can be a known or commercially available one. In particular, the vinyl acetate component (VA component) is preferably 10 to 46 mass%, more preferably 15 to 41 mass%.

  The thickness of the adhesive resin layer is not limited, but is preferably about 5 to 50 μm.

  The non-foamed resin layer A may be formed on the upper surface of the foaming agent-containing resin layer for the purpose of clarifying the pattern when forming the pattern layer or improving the scratch resistance of the foamed resin layer.

  Examples of the resin component of the non-foamed resin layer A include polyolefin resins, (meth) acrylic resins, thermoplastic polyester resins, polyvinyl alcohol resins, fluorine resins, and the like. Among these, polyolefin resins are preferable.

  Examples of the polyolefin resin include polyethylene (low density polyethylene (LDPE) or high density polyethylene (HDPE)), a single resin such as polypropylene, polybutene, polybutadiene, polyisoprene, ethylene, and an α olefin having 4 or more carbon atoms. Copolymers (linear low density polyethylene (LLDPE)), ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, and other ethylene Examples thereof include at least one of (meth) acrylic acid copolymer, ethylene-vinyl acetate copolymer (EVA), saponified ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ionomer.

  The thickness of the non-foamed resin layer A is not limited, but is preferably about 2 to 50 μm.

  In the present invention, an embodiment in which the non-foamed resin layer B, the foaming agent-containing resin layer, and the non-foamed resin layer A are formed in order from the viewpoint of production described later is also preferable. The non-foamed resin layer B and / or the non-foamed resin layer A may be formed by extrusion film formation, or may be formed by heat laminating each film.

Pattern Pattern Layer In the laminated sheet of the present invention, a pattern pattern layer may be formed on the foaming agent-containing resin layer, the non-foamed resin layer A, or a primer layer described later, if necessary.

  The pattern layer imparts design properties to the laminated sheet and the foamed laminated sheet. Examples of design patterns include wood grain patterns, stone patterns, sand grain patterns, tiled patterns, brickwork patterns, fabric patterns, leather patterns, geometric figures, characters, symbols, abstract patterns, etc. Can be selected.

  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. These solvents (or dispersion media) can be used alone or in the form of a mixture.

  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.

A primer layer may be formed on the primer layer foaming agent-containing resin layer, the non-foamed resin layer A, the design pattern layer, or the film layer described later, if necessary.

  As the resin contained in the primer layer, for example, acrylic, vinyl chloride-vinyl acetate copolymer, polyester, polyurethane, chlorinated polypropylene, chlorinated polyethylene, and the like can be used. Particularly, acrylic, chlorinated polypropylene, etc. Is desirable.

  Examples of the acrylic include, for example, poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, and (meth) acrylate methyl- (meth) acrylic acid. (Meth) such as butyl copolymer, (meth) ethyl acrylate- (meth) butyl acrylate copolymer, ethylene- (meth) methyl acrylate copolymer, styrene- (meth) methyl acrylate copolymer An acrylic resin made of a homopolymer or a copolymer containing an acrylate ester may be mentioned.

  Polyurethane is a composition having a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent).

  As the polyol, one having two or more hydroxyl groups in the molecule, for example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol and the like are used.

  As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used. For example, aromatic isocyanate such as 2-4 tolylene diisocyanate, xylene diisocyanate, 4-4 diphenylmethane diisocyanate, or aliphatic (or alicyclic) such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate ) Isocyanates are used.

  Although the thickness of a primer layer is not limited, about 0.1-10 micrometers is preferable and about 0.1-5 micrometers is more preferable.

A film layer may be formed on the film layer foaming agent-containing resin layer, non-foamed resin layer A, picture pattern layer, or primer layer as necessary. By providing the film layer, the foaming agent-containing resin layer (foamed resin layer) and the pattern layer can be protected, and the surface properties of the laminated sheet (foamed laminated sheet) can be further improved.

  Examples of the resin forming the film layer include polyolefin resins, (meth) acrylic resins, thermoplastic polyester resins, polyvinyl alcohol resins, thermoplastic resins such as fluorine resins, and various copolymer resins. Among these, polyolefin resins are particularly preferable.

  Examples of the polyolefin-based resin include, for example, polyethylene (low density polyethylene (LDPE) or high density polyethylene (HDPE)), a single resin such as polypropylene, polybutene, polybutadiene, and polyisoprene, ethylene and an α-olefin having 4 or more carbon atoms. Copolymer (linear low density polyethylene (LLDPE)), ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc. At least one selected from ethylene (meth) acrylic acid copolymer, ethylene-vinyl acetate copolymer (EVA), saponified ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ionomer; Can be mentioned.

  The film layer may be formed by extrusion film formation, or may be formed by heat laminating a commercially available film. In the case of film formation, the film may be formed as a single layer or may be formed into multiple layers as necessary. Although the thickness of a film layer is not limited, about 5-50 micrometers is preferable and about 10-25 micrometers is more preferable.

Surface protective layer The surface of the foaming agent-containing resin layer, non-foamed resin layer A, pattern layer, primer layer, or film layer has a surface protective layer for the purpose of adjusting the gloss and / or protecting the pattern layer. Also good.

  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.

  When a surface protective layer is formed for the purpose of surface strength (scratch resistance, etc.), contamination resistance, pattern layer protection, etc. of laminated sheets, 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.

An embossed pattern may be provided on the front surface of the embossed laminated sheet or the foamed laminated sheet. In this case, what is necessary is just to emboss from the uppermost surface layer (opposite side to the fibrous sheet). 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 textured surface, a grained surface, a hairline, a tiled tone, a painted wall tone, and a multilined groove.

≪Foamed laminated sheet≫
The foamed laminated sheet of the present invention can be obtained by foaming the foaming agent-containing resin layer of the laminated sheet. The heating conditions at the time of foaming 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. Moreover, it is preferable that the expansion ratio of a foamed resin layer is 8 times or more, and it is more preferable that it is about 8 to 10 times. By setting the expansion ratio within the above range, the cost can be reduced, and the nonflammability of the foamed laminated sheet can be increased.

≪Laminated sheet and foamed laminated sheet manufacturing method≫
As a manufacturing method of a lamination sheet, the manufacturing method which laminates | stacks a foaming agent containing resin layer at least on a fibrous sheet is mentioned, for example.

  Moreover, as a manufacturing method of a foaming lamination sheet, in the manufacturing method of a lamination sheet, after laminating | stacking a foaming agent containing resin layer, it heat-processes and the manufacturing method which uses a foaming agent containing resin layer as a foaming resin layer is mentioned.

  When the foaming agent-containing resin layer has a non-foamed resin layer on one side or both sides, simultaneous extrusion film formation by a T-die extruder is suitable. For example, in the case of having non-foamed resin layers on both surfaces, a multi-manifold type T-die capable of simultaneously forming three layers by simultaneously extruding molten resins corresponding to the three layers can be used.

  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 film formation, an extrusion port (so-called die) of the extruder is used. Inorganic filler residues (so-called eyes and eyes) are easily generated, and this tends to be a foreign matter on the surface of the foaming agent-containing resin layer. Therefore, when an inorganic filler is contained in the resin composition forming the foaming agent-containing resin layer, it is preferable to form a three-layer coextrusion film as described above. That is, it is possible to suppress the occurrence of the above-mentioned corners by co-extrusion film formation in a mode in which the foaming agent-containing resin layer is sandwiched between non-foamed resin layers.

  After forming the foaming agent-containing resin layer, electron beam irradiation may be performed. Thereby, the resin component can be cross-linked to adjust the surface strength, foaming characteristics, etc. of the foamed resin layer. 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 50 kGy. A known electron beam irradiation apparatus can be used as the electron beam source.

  On the foaming agent-containing resin layer, if necessary, a pattern layer and a primer layer are formed in any order, and if necessary, a surface protective layer is formed to form a laminated sheet, and then heat-treated. A foaming laminated sheet is obtained by making the foaming agent-containing resin layer into a foamed resin layer. FIG. 1 illustrates a layer configuration of a laminated sheet in which a non-foamed resin layer B, a foaming agent-containing resin layer, a non-foamed resin layer A, a pattern pattern layer, a primer layer, and a surface protective layer are sequentially formed on a fibrous sheet. . Each of these layers can be laminated by combining coating such as printing and coating, extrusion film formation and the like, and coating such as printing and coating can be performed according to a conventional method.

  The heat treatment conditions may be any conditions 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. Further, when an embossed pattern is added, it is carried out by a known means such as pressing an embossed plate.

  The laminated sheet of the present invention uses an ethylene- (meth) acrylic acid copolymer as a resin for forming the foaming agent-containing resin layer because the foaming agent-containing resin layer contains a nonpolar polyolefin wax. The foamed resin layer obtained by foaming the foaming agent-containing resin layer is excellent in the retention of bubbles, the foaming of the foamed resin layer is broken, and the embossing is performed from the top surface layer of the foamed laminated sheet. Occurrence of puncture when applied is suppressed.

It is a schematic diagram which shows an example of the layer structure of the lamination sheet of this invention.

  The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Examples 1-4 and Comparative Examples 1-5
A resin composition for forming a foaming agent-containing resin layer was prepared. Specifically, the resin composition prepared according to the formulation in Table 1 is kneaded using a lab plast mill (manufactured by HAAKE) at a temperature of 110 ° C., a rotor rotation speed of 50 rpm, and a kneading time of 10 minutes, and contains a foaming agent. A resin composition for forming a resin layer was obtained. In addition, the numerical value of Table 1 represents a mass part.

  Adjust the extrusion amount so that the thickness of each resin layer becomes 5μm / 50μm / 5μm in the order of non-foamed resin layer A, foaming agent-containing resin layer, and non-foamed resin layer B from the three-type three-layer laminated T-die Resin film formation was performed to obtain a flat film-like resin sheet. The non-foamed resin layer A is an ethylene-methacrylic acid copolymer “manufactured by Mitsui DuPont Polychemical, trade name: Nucrel N1560”, the foaming agent-containing resin layer is a resin composition described in Table 1, and the non-foamed resin layer B is an ethylene- It was formed using a vinyl acetate copolymer “manufactured by Tosoh Corporation, trade name: Ultrasen 750”. The extrusion conditions at this time were a cylinder temperature of 130 ° C. for the non-foamed resin layer A, a cylinder temperature of 120 ° C. for the foaming agent-containing resin layer, a cylinder temperature of 120 ° C. for the non-foamed resin layer B, and a die temperature of 120 ° C.

  Next, a non-foamed resin layer B and a fibrous sheet made of paper pulp having a width of 970 mm: wallpaper paper “WK-665, manufactured by Kojin” are brought into contact with each other, and a flat film-like resin sheet and a fibrous sheet Were laminated. At this time, the flat film-like resin sheet is formed so that the width is narrower than the fiber sheet in the width direction, and is laminated so as to be positioned at the center of the fiber sheet, and the fiber sheet is formed from both ends. Was protruded by 5 mm. Subsequently, it heated to 120 degreeC from the fiber sheet side, and was thermocompression-bonded using the laminate roll. This state is referred to as the original fabric α.

  Next, electron beam irradiation (195 kV, 60 kGy) was performed from the fiber sheet side of the raw fabric α to obtain a laminated sheet.

  Finally, the foamed laminated sheet was obtained by heating at 220 ° C. for 35 seconds to foam the foaming agent-containing resin layer to obtain a foamed resin layer.

Test example 1
The state of the surface of the foamed laminated sheet produced in the examples and comparative examples was visually evaluated. As the evaluation criteria, a case where foamed cells were not broken on the surface of the foamed laminated sheet was evaluated as ◯, and a case where foamed bubbles were observed was marked as x.

Test example 2
From the two layers so that the thickness of each layer is 8 μm / 4 μm in the order of the layer formed of low density polyethylene (LDPE) and the layer formed of acid-modified polyolefin on the raw fabric α of the above examples and comparative examples. The resulting film layer was laminated by extrusion lamination. The extrusion lamination was performed so that the non-foamed resin layer A of the raw fabric α and the acid-modified polyolefin layer were in contact with each other. In each layer, LDPE was “Nippon Polyethylene, trade name: Novatec”, and the acid-modified polyolefin was “Mitsubishi Chemical, trade name: Modic”. Further, a surface protective layer of 2.5 μm is provided on the layer formed by LDPE using an ionizing radiation curable resin paint “SEICA BEAM (manufactured by Dainichi Seika)”, and an electron beam (195 KV 60 KGy) is provided thereon. Irradiation was performed to simultaneously crosslink the surface protective layer and the resin layer. Furthermore, the foaming agent-containing resin layer was foamed by heating at 220 ° C. for 35 seconds to obtain a foamed resin layer. The foamed laminated sheet was obtained by pressing the embossing roll having a grainy concavo-convex pattern from above the surface protective layer to shape the concavo-convex pattern.

  Generation | occurrence | production of the puncture of the foaming lamination sheet produced in the Example and the comparative example was evaluated visually. The evaluation criteria for the puncture evaluation were ○ when the puncture occurred on the surface of the foamed laminated sheet and × when the puncture did not occur.

The expansion ratio of the foamed laminated sheets prepared in Examples and Comparative Examples was calculated by the following formula.
(Foaming ratio) = {(Thickness of foamed laminated sheet) − (Total thickness excluding foaming agent-containing resin layer of laminated sheet)} / (Thickness of foaming agent-containing resin layer of laminated sheet)
The results of Test Example 1 and Test Example 2 are shown in Table 2.

  As is clear from the results in Table 2, the foamed laminate sheets (Examples 1 to 4) of the present invention obtained by foaming the foaming agent-containing resin layer of the laminate sheet of the present invention have a nonpolar foaming agent-containing resin layer. By containing the polyolefin wax, the foamed resin layer obtained by foaming the foaming agent-containing resin layer is excellent in foam retention even when the foaming ratio is 8 times or higher, and the foamed resin layer is foamed. Generation of cell bubble breakage is suppressed. Furthermore, even when the expansion ratio is a high ratio of 8 times or more, the occurrence of puncture when embossing is performed from the top surface layer of the foamed laminated sheet is suppressed.

1. 1. Fiber sheet Non-foamed resin layer B
3. 3. Foaming agent-containing resin layer Non-foamed resin layer A
5. Pattern layer 6 Primer layer 7. Surface protective layer

Claims (11)

A laminated sheet in which at least a foaming agent-containing resin layer is laminated on a fibrous sheet,
The foaming agent-containing resin layer contains an ethylene- (meth) acrylic acid copolymer and a nonpolar polyolefin wax.   The laminated sheet according to claim 1, wherein the nonpolar polyolefin wax is a nonoxidized polyethylene wax.   The laminated sheet according to claim 1 or 2, wherein the content of the nonpolar polyolefin wax is 0.5 to 10 parts by mass with respect to 100 parts by mass of the ethylene- (meth) acrylic acid copolymer.   The laminated sheet according to any one of claims 1 to 3, wherein the foaming agent-containing resin layer has a non-foamed resin layer on one side or both sides.   The lamination sheet in any one of Claims 1-4 which has a pattern pattern layer on the said foaming agent containing resin layer.   The lamination sheet in any one of Claims 1-5 which has a film layer on the said foaming agent containing resin layer.   The laminated sheet according to any one of claims 1 to 6, which has a surface protective layer made of an ionizing radiation curable resin on the outermost surface.   The laminated sheet according to any one of claims 1 to 7, wherein the foaming agent-containing resin layer is resin-crosslinked by electron beam irradiation.   The foaming lamination sheet obtained by making the said foaming agent containing resin layer of the lamination sheet in any one of Claims 1-8 foam, and setting it as a foaming resin layer.   The foaming lamination sheet according to claim 9 whose foaming magnification of said foaming resin layer is 8 or more times.   The foaming laminated sheet of Claim 9 or 10 with which the embossing was given from the outermost surface layer.

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