JP5742569B2 - Method for producing foamed laminated sheet - Google Patents

Description

  The present invention relates to a method for producing a foam laminate sheet.

  Conventionally, a foamed laminated sheet (foamed decorative sheet) is known in which a foamed resin layer of vinyl chloride resin is formed on a paper-based substrate (for example, 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.

  The foamed laminated sheet is generally obtained by forming a foaming agent-containing resin layer on a paper substrate and then foaming the foaming agent-containing resin layer by heating. Examples of the method for forming the foaming agent-containing resin layer include a calendar method, an extrusion method using a T-die, and a method of applying a resin emulsion.

  By the way, when the foamed laminated sheet is produced, electron beam irradiation is performed on the resin layer including the foaming agent-containing resin layer for the purpose of adjusting the melt tension by resin crosslinking of the foaming agent-containing resin layer. There is a case. For example, in Patent Document 1, as a method for producing foamed wallpaper, a polyolefin-based resin containing a foaming agent is extruded and formed on a paper base material to produce a foamed wallpaper raw material. A method is described in which after the irradiation, a decorative layer with a printed pattern is provided on the surface of the olefin resin layer, and the olefin resin layer is heated and foamed. Further, in Patent Document 2, as a method for producing foam wallpaper, a resin layer including the foaming agent-containing resin layer is extruded to form a laminate, and the laminate is cooled. After slitting the laminate so that it is smaller than the width of the substrate, and further laminating the laminate on a heated paper substrate (so-called thermal lamination) to produce a foam wallpaper original fabric, The methods of electron beam irradiation, decoration layer formation and heat foaming are described.

  However, since the foamed wallpaper manufacturing methods described in Patent Document 1 and Patent Document 2 are both subjected to electron beam irradiation after laminating a resin layer containing a foaming agent-containing resin layer on a paper substrate, Depending on the irradiation conditions of the electron beam, the blending of the resin layer, etc., the electron beam may reach the paper-based substrate. In this case, since the paper base is irradiated with an electron beam, there is a problem that the organic matter contained in the paper base is easily discolored by the heat foaming process. The above discoloration (so-called “burn”) adversely affects the design of the foamed laminated sheet, and there is a problem that the paper base is deteriorated by electron beam irradiation.

  Therefore, development of the manufacturing method of the foaming lamination sheet which can reduce discoloration of the paper base material after the heat foaming process by electron beam irradiation is desired.

Japanese Patent No. 3923969 Japanese Patent No. 4006604

  An object of this invention is to provide the manufacturing method of the foaming lamination sheet which can reduce discoloration of the paper-like base material after the heat foaming process by electron beam irradiation.

  As a result of intensive studies, the present inventor has found that the above object can be achieved by producing a foamed laminated sheet by a production method including a specific production process, and has completed the present invention.

That is, this invention relates to the manufacturing method of the following foaming lamination sheet.
1. The manufacturing method of a foaming lamination sheet which contains the following (1)-(4) processes in order:
(1) The process of forming the laminated body which has a foaming agent containing resin layer or a foaming agent containing resin layer,
(2) A step of irradiating an electron beam to the laminate having the foaming agent-containing resin layer or the foaming agent-containing resin layer,
(3) A step of laminating a paper-based substrate on the foaming agent-containing resin layer or a laminate having a foaming agent-containing resin layer, and (4) a step of heating and foaming the foaming agent-containing resin layer.
2. The manufacturing method of the foaming lamination sheet of said claim | item 1 which fixes the edge part of the laminated body which has the said foaming agent containing resin layer or a foaming agent containing resin layer in the said (2) process, and irradiates an electron beam.
3. Item 3. The method for producing a foamed laminated sheet according to Item 1 or 2, wherein in the step (1), a laminate comprising the nonfoamed resin layer A, the foaming agent-containing resin layer, and the nonfoamed resin layer B is formed.
4). The said foaming agent containing resin layer is a manufacturing method of the foaming lamination sheet in any one of said claim | item 1-3 containing at least 1 sort (s) chosen from the group which consists of polyethylene and an ethylene copolymer as a resin component.
5. Item 5. The method for producing a foamed laminated sheet according to any one of Items 1 to 4, further comprising a step of heating the paper base material before the step (3).
6). The foam lamination according to any one of Items 1 to 5, further comprising a step of performing a decoration treatment on the foaming agent-containing resin layer or the laminate after the step (3) or after the step (4). Sheet manufacturing method.

  Hereinafter, the manufacturing method of the foaming lamination sheet of this invention is demonstrated in detail.

The method for producing a foamed laminated sheet of the present invention includes the following steps (1) to (4):
(1) The process of forming the laminated body which has a foaming agent containing resin layer or a foaming agent containing resin layer,
(2) A step of irradiating an electron beam to the laminate having the foaming agent-containing resin layer or the foaming agent-containing resin layer,
(3) a step of laminating a paper-based substrate on the foaming agent-containing resin layer or a laminate having a foaming agent-containing resin layer, and (4) a step of heating and foaming the foaming agent-containing resin layer,
In order.

  In the method for producing the foamed laminate sheet, after the electron beam irradiation is performed on the foaming agent-containing resin layer or the laminate having the foaming agent-containing resin layer in the step (2), the paper base material is laminated in the step (3). The paper substrate is not irradiated by the electron beam. Therefore, discoloration of the paper-based substrate due to the heat foaming treatment can be reduced while adjusting the melt tension by resin crosslinking of the foaming agent-containing resin layer by electron beam irradiation. Moreover, according to the said manufacturing method, the foaming lamination sheet excellent in the bending resistance can be obtained.

  Hereinafter, the production method of the present invention will be described in detail.

(1) Step (1) In the step, a laminate having a foaming agent-containing resin layer or a foaming agent-containing resin layer is formed. That is, in step (1), the foaming agent-containing resin layer may be formed as a single layer, or a laminate comprising a plurality of layers having a foaming agent-containing resin layer (for example, non-foaming resin layer A, the foaming agent-containing resin) The laminate comprising the layer and the non-foamed resin layer B) may be formed. In the following description, these are collectively referred to as “laminated body” for the sake of convenience, and the laminated body will be described as including a foaming agent-containing resin layer single layer.

(I) Foaming agent-containing resin layer The foaming agent-containing resin layer contains at least a resin component and a foaming agent.

  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.

  In the present invention, the foaming agent-containing resin layer is made of a group consisting of polyethylene as a resin component and an ethylene copolymer having monomers other than ethylene and ethylene (hereinafter also abbreviated as “ethylene copolymer”). It is preferable to contain at least one selected.

  Polyethylene and ethylene copolymers are suitable for extrusion film formation in terms of melting point and MFR. Examples of the ethylene copolymer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer ( EMA), ethylene- (meth) acrylic acid copolymer (EMAA), ethylene-α olefin copolymer, and the like. These ethylene copolymers can be used alone or in admixture of two or more.

  As the resin component of the foaming agent-containing resin layer, in particular, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene- (meth) acrylic acid copolymer, and a mixture of polyethylene and ethylene-α-olefin copolymer It is preferable to contain any one of these. When the resin component contains a mixture of polyethylene and an ethylene-α-olefin copolymer, the content of the ethylene-α-olefin copolymer is preferably 50% by weight or more.

  Any one of ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene- (meth) acrylic acid copolymer, and a mixture of polyethylene and ethylene-α-olefin copolymer and one of other resins When using together with a seed | species or more, 70 weight% or more is preferable and, as for content of any one said resin component, 80 weight% or more is more preferable.

  The MFR of the polyethylene or ethylene copolymer is preferably 9 to 100 g / 10 minutes, and more preferably 9 to 20 g / 10 minutes. By adopting such MFR, the extrusion film forming property is further enhanced. 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, 5-30 weight% is preferable as an ethylene copolymer content of monomers other than ethylene, and 9-20 weight% is more preferable. By adopting such a copolymerization ratio, the extrusion film forming property is further improved, and the flexibility at the time of product becomes appropriate. As a specific example, the ethylene-vinyl acetate copolymer has a vinyl acetate copolymerization ratio (VA amount) of preferably 9 to 25% by weight, more preferably 9 to 20% by weight. Moreover, 5-25 weight% is preferable as a copolymerization ratio (MMA amount) of a methylmethacrylate, and, as for the ethylene-methylmethacrylate copolymer, 5-15 weight% is more preferable.

  The pyrolytic foaming agent can be selected from known foaming agents. Examples 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 is set according to the type of foaming agent and the foaming ratio. In the present invention, the expansion ratio is 5 times or more, preferably about 6.5 to 10 times. The pyrolytic foaming agent is preferably about 1 to 10 parts by weight with respect to 100 parts by weight of the resin component.

  An additive may be added to the foaming agent-containing resin layer as long as the effect of the present invention is not affected. For example, pigments, foam stabilizers, antioxidants, foaming aids (zinc compounds), crosslinking agents, surface treatment agents, fluorescent whitening agents, fungicides, lubricants, and the like can be used as additives.

  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 , And organic pigments halogenated phthalocyanine), or the like. About 10-50 weight part is preferable with respect to 100 weight part of resin components, and, as for content of a pigment, about 15-40 weight part is more preferable.

  Examples of the foam stabilizer include alkyl sulfonate and alkyl benzene sulfonate. Specifically, at least one of sodium dodecylbenzenesulfonate and calcium dodecylbenzenesulfonate is preferable.

  Further, a metal soap such as zinc stearate and a surfactant can be used. These contents are preferably about 0.3 to 10 parts by weight, and more preferably about 1 to 5 parts by weight with respect to 100 parts by weight of the resin component.

  Examples of the antioxidant include 2,6-ditert-butyl-p-cresol and tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxy-phenyl), which are phenolic antioxidants. Propionate] methane, phosphorous antioxidant tris (2,4-di-butylphenyl) phosphite, distearyl pentaerythritol diphosphite and the like.

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

  The content of the zinc compound is preferably about 0.001 to 20 parts by weight and more preferably about 0.001 to 10 parts by weight with respect to 100 parts by weight of the resin component.

  Although the thickness of a foaming agent containing resin layer is not limited, 40-100 micrometers is preferable in a non-foaming state (before foaming). 400-700 micrometers is preferable after foaming.

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

(Ii) Non-foamed resin layer A
In the laminate of the present invention, a non-foamed resin layer (non-foamed resin layer A) may be further formed on the front surface of the foaming agent-containing resin layer.

  The non-foamed resin layer A mainly protects the foaming agent-containing resin layer.

  The resin component contained in the non-foamed resin layer A is not particularly limited, and for example, polyethylene, an ethylene copolymer, an ionomer resin, or the like can be used. Examples of the ethylene copolymer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl acrylate copolymer (EMA). ), Ethylene- (meth) acrylic acid copolymer (EMAA), ethylene-α olefin copolymer, and the like. These resin components can be used alone or in admixture of two or more.

In order to obtain particularly excellent scratch resistance and abrasion resistance, the resin component is at least one of acrylic acid (CH ₂ ═CHCOOH) and methacrylic acid (CH ₂ ═C (CH ₃ ) COOH). A copolymer obtained by a combination of a monomer and ethylene can be suitably used as a resin component. More specifically, it is desirable to use at least one of an ethylene- (meth) acrylic acid copolymer and an ionomer resin. As the ionomer resin, a resin having a structure in which the molecules of the ethylene- (meth) acrylic acid copolymer 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 caused by hydrogen bonds in the resin. In addition, these can use a well-known or commercially available thing.

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

  The thickness of the non-foamed resin layer A is not limited, but is preferably about 3 to 50 μm, more preferably about 5 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%.

(Iii) Non-foamed resin layer B
In the laminate of the present invention, if necessary, a non-foamed resin layer (non-foamed resin layer B) is further provided on the back surface of the foaming agent-containing resin layer (the surface opposite to the surface in contact with the non-foamed resin layer A). It may be formed. In particular, when the non-foamed resin layer B is formed as an adhesive layer for adhering the foaming agent-containing resin layer and a paper substrate to be described later, excellent adhesion can be obtained. As the non-foamed resin layer B, for example, an ethylene-vinyl acetate copolymer 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 3 to 50 μm, more preferably about 5 to 15 μm.

(Iv) Lamination of each layer The method for forming a laminate is not particularly limited, and examples thereof include single-layer extrusion using a T-die extruder and multilayer coextrusion. In particular, in the present invention, it is possible to use a feed block type or multi-manifold type T-die capable of simultaneously forming a plurality of layers by simultaneously extruding a plurality of types of molten resins. If there is a difference, the multi-manifold type can be used preferably.

  Specifically, in the case of forming a laminate by melt-extrusion of the foaming agent-containing resin layer and the non-foaming resin layer A, the composition for forming the non-foaming resin layer A, and the foaming agent-containing resin layer are The composition to be formed may be placed in a separate cylinder, and two types and two layers may be extruded simultaneously to form a film.

  Further, when forming the non-foamed resin layer B, a composition for forming the non-foamed resin layer A, a composition for forming the foaming agent-containing resin layer, and a composition for forming the non-foamed resin layer B What is necessary is just to put a thing in a separate cylinder, and to extrude 3 types and 3 layers simultaneously, and to form a film.

  The molten resin temperature at the time of co-extrusion is not particularly limited, and may be appropriately set according to the resin used, the foaming agent, and the like.

  In addition, when a foaming agent-containing resin layer is extruded and formed into a single layer, when the layer contains an inorganic filler (filler) such as calcium carbonate, the extrusion port (so-called die) of the extrusion molding machine is filled with an inorganic filler. A residue of the agent (so-called eyes) tends to adhere, and this tends to be a foreign matter on the sheet surface. In that case, it is preferable to co-extrusion the non-foamed resin layer A and the non-foamed resin layer B together with the foaming agent-containing resin layer as a layer not containing an inorganic filler. 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.

(2) Step (2) In the step (2), the laminate is irradiated with an electron beam. The foaming agent-containing resin layer can be resin-crosslinked by irradiating the laminate with an electron beam. In addition, when laminating a surface protective layer containing an ionizing radiation curable resin, which will be described later, after the step (1) and before the step (2), the foaming agent-containing resin layer and the surface protective layer are formed by electron beam irradiation. At the same time, the resin can be crosslinked.

  Moreover, by irradiating an electron beam in the state which fixed the said laminated body by 1) grasping the both ends of a laminated body with a tenter clip, 2) pressing another roll on the edge of a laminated body, etc. on a roll Further, shrinkage caused by resin crosslinking can be suppressed. Therefore, width (width) shrinkage, thickness variation, wrinkle generation, and the like of the laminate can be suppressed.

  The electron beam may be irradiated from the front surface side to the back surface side of the laminate, or may be irradiated from the back surface side to the front surface side. In the present specification, the front side refers to the laminate side, and the back side refers to the paper-based substrate side. In FIG. 1 described later, the upper side is the front surface side, and the lower side is the back surface side.

  The conditions for electron beam irradiation are about 150 to 220 kV and about 20 to 60 KGy.

  Moreover, in this invention, the said laminated body can be cooled after (1) process and before (2) process. The cooling temperature is preferably such that the surface of the laminate is 60 ° C. or lower, particularly 30 to 40 ° C. The cooling means is not limited, and any known means may be adopted as appropriate. In particular, the laminate can be suitably cooled by holding the laminate in a metal roll (chill roll) through which cooling water is passed.

  Further, in the present invention, the laminate can be slit after the step (2) and before the step (3). By making the slit, the width of the laminate can be made smaller than the width of the paper-based substrate described later. Therefore, when the foaming agent is heated and foamed in the subsequent step, the resin constituting the resin layer protrudes from the end of the foam, and as a result, problems such as fouling the interior of the foaming furnace can be avoided. .

  In particular, immediately after forming the laminate in the step (1), the thickness of both end portions is thicker than that of the central portion. Therefore, when the roll is rolled up without slits, wrinkles are generated in the laminate. Cheap. Moreover, when slitting is performed before irradiating an electron beam in the step (2), the laminate may shrink due to resin cross-linking by electron beam irradiation after the slit, and variations in dimensions and thickness may occur. Therefore, in the present invention, it is preferable to cool the laminated body after the step (2) and before the step (3), and further slit.

  The method for slitting is not particularly limited, and a known means may be employed. For example, a laser cut method, a shear cut method, a score cut method, etc. are mentioned.

(3) Step (3) In step (3), a paper base is laminated on the laminate. For example, when the laminate is obtained by laminating the foaming agent-containing resin layer and the non-foaming resin layer A as described above, a paper base is laminated on the foaming agent-containing resin layer side of the laminate. When the laminate is laminated by melt extrusion so that the non-foamed resin layer B, the foaming agent-containing resin layer, and the non-foamed resin layer A are in this order, the non-foamed resin layer B side of the laminate Laminate a paper-based substrate. In addition, in this invention, what laminated | stacked the laminated body on the paper-like base material is called the raw material for foaming lamination sheets.

  In the present invention, after the electron beam irradiation is performed on the laminate in the step (2), the paper base material is laminated in the step (3), and therefore the paper base material is not irradiated with the electron beam. Therefore, discoloration of the paper-based substrate during heat foaming due to electron beam irradiation can be reduced.

  The material of the paper-based substrate is not particularly limited as long as it has mechanical strength, heat resistance, etc. suitable as a laminated sheet substrate, and a fiber sheet (for example, paper, nonwoven fabric, etc., also simply referred to as fiber) can be generally used. . The fiber sheet is not limited, and a known wallpaper base material (backing paper) can be used.

  Specifically, among fiber sheets, general paper for wallpaper (pulp-based sheets sized with a known sizing agent); flame-retardant paper (pulp-based sheets such as guanidine sulfamate and guanidine phosphate) Treated with a flame retardant); inorganic paper containing inorganic additives such as aluminum hydroxide and magnesium hydroxide; fine paper; thin paper.

The basis weight of the paper quality substrate is not limited, but preferably about 40~300g / ^{m 2,} about 50 to 80 g / ^{m 2} is more preferable.

  The method for laminating the paper substrate on the laminate is not limited. For example, it is preferable to pressurize and laminate the laminate and the paper base. In particular, it is preferable to heat the surface of the paper substrate before pressurizing and laminating. Although heating temperature is not limited, 80-160 degreeC is preferable. What is necessary is just to set a heating time suitably according to heating temperature etc. FIG.

(4) Step (4) In step (4), the foamed resin layer is formed by heating the foaming agent-containing resin layer. In the present invention, since the foaming agent-containing resin layer is cross-linked by electron beam irradiation prior to heating, the melt tension of the foaming agent-containing resin layer is adjusted and a desired foaming ratio is easily obtained.

  The heating conditions are not limited as long as the foamed resin layer is formed by the decomposition of the pyrolytic foaming agent. The heating temperature is preferably about 210 to 250 ° C, more preferably about 220 to 240 ° C. The heating time is preferably about 15 to 50 seconds, and more preferably about 20 to 45 seconds.

Other processes (decoration processing)
On the surface of the foaming agent-containing resin layer (or the surface of the non-foamed resin layer A), a pattern pattern layer described later may be formed as necessary. A surface protective layer can be further provided on the surface of the pattern layer for the purpose of adjusting the gloss and / or protecting the pattern layer. If the design pattern layer or surface protective layer is difficult to adhere to the non-foamed resin layer, or if the surface protective layer is difficult to adhere to the design pattern layer, a primer between the layers is necessary. It may be through layers. Furthermore, in this invention, an embossed pattern can also be attached | subjected to the surface (front surface). The formation of the pattern layer, the formation of the surface protective layer, and the application of the embossed pattern may be performed after the step (3) or after the step (4).

(I) Formation of pattern pattern layer The pattern pattern layer imparts design properties to the foamed laminated sheet. 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. A design pattern can be selected according to the kind of foam lamination sheet.

  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 pattern layer, a primer layer may be formed in advance as necessary, or the surface of the non-foamed resin layer A may be subjected to corona discharge treatment. The corona discharge treatment can be performed according to a known method.

  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.

(Ii) Formation of surface protective layer The type of surface protective layer is not limited, but it is a one-part curable type or two-part type using a binder resin or solvent equivalent to the pattern layer, such as acrylic resin or urethane resin. A curable resin can be used. Further, a surface protective layer formed by curing a resin layer formed using an ionizing radiation curable resin by electron beam irradiation is preferable because it can further improve the surface strength, stain resistance, etc. of the foamed laminated sheet. .

  The ionizing radiation curable resin is not particularly limited, and a prepolymer (including an oligomer) containing a radical polymerizable double bond capable of undergoing a polymerization and crosslinking reaction by irradiation of an electron beam in the molecule and / or a transparent mainly composed of a monomer. Resin can be used. These prepolymers or monomers can be used alone or in combination. The curing reaction is usually a cross-linking curing reaction.

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

  For gloss adjustment, it is desirable to form a surface protective layer containing a known filler such as silica. In addition, an additive such as silicone can be added in order to impart slipperiness and easy wiping of dirt. In addition, you may add functional materials, such as a deodorizer and an antibacterial agent, as needed. As a method for forming the surface protective layer, a known method such as gravure printing can be employed.

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

(Iii) Embossing treatment In the present invention, an embossing pattern may be appropriately applied. Embossing can be performed by known means such as pressing an embossed plate. For example, a desired embossed pattern can be formed by pressing the embossed plate after heat-softening the pattern layer (or surface protective layer). 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.

  The foamed laminated sheet of the present invention can be used for applications such as foamed wallpaper, a laminated decorative skin material, a cushioning flooring material, and a heat insulating decorative material.

  In the method for producing a foamed laminated sheet of the present invention, after the electron beam irradiation is performed on the laminate having the foaming agent-containing resin layer or the foaming agent-containing resin layer in the step (2), the paper base material is laminated in the step (3). Therefore, the paper base is not irradiated with the electron beam. Therefore, discoloration of the paper-based substrate due to the heat foaming treatment can be reduced while adjusting the melt tension by resin crosslinking of the foaming agent-containing resin layer by electron beam irradiation. Moreover, according to the said manufacturing method, the foaming lamination sheet excellent in the bending resistance can be obtained.

It is a conceptual diagram of the foaming lamination sheet obtained by Example 1 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.

Example 1
Using a three-type three-layer multi-manifold T-die extruder, the film was extruded and formed in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B to a thickness of 10 μm / 70 μm / 10 μm. Thereby, the laminated body which consists of non-foaming resin layer A / foaming agent containing resin layer / non-foaming resin layer B was obtained.

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

  The laminate was cooled by holding the laminate in a metal roll (chill roll) through which cooling water was passed so that the surface temperature of the laminate was 60 ° C. or lower.

  Next, an electron beam (195 kV, 30 KGy) was irradiated from the non-foamed resin layer A side to crosslink the laminate. Thereafter, the laminate was slit so that the width was 10 mm smaller than a paper-based substrate described later.

  Next, a paper base material (backing paper) “CP-65PDK (manufactured by Chuetsu Pulp & Paper Co., Ltd.)” was prepared, and after heating to 90 ° C., the above laminate was laminated to form a non-foamed resin layer A raw material for a foamed laminated sheet comprising A / foaming agent-containing resin layer / non-foamed resin layer B / paper-based substrate was obtained.

  Next, after a corona discharge treatment is performed on the non-foamed resin layer A, a texture pattern is printed on the non-foamed resin layer A by gravure printing using a water-based ink “Hydric” (manufactured by Dainichi Seika Kogyo Co., Ltd.). Printed.

  Next, the foamed laminated sheet original fabric on which the above-mentioned texture pattern was printed was heated in an oven (at 220 ° C. for 35 seconds) to foam the foaming agent-containing resin layer.

  Finally, the foam was embossed with a texture pattern at about 110 ° C. to obtain a foam laminated sheet.

  Each layer was formed using the following components.

  The non-foamed resin layer A was formed of a polyethylene resin “Petrocene 202, manufactured by Tosoh Corporation”.

The foaming agent-containing resin layer
50 parts by weight of polyethylene resin “Petrocene 208, manufactured by Tosoh Corporation”
50 parts by weight of an ethylene-α olefin copolymer “LUMITAC 54-1 manufactured by Tosoh Corporation”
4 parts by weight of a foaming agent “Vinole Hall AC # 3, manufactured by Eiwa Chemical Industry Co., Ltd.”
30 parts by weight of calcium carbonate “Whiteon H, average particle size: 22 μm, manufactured by Shiroishi Kogyo Co., Ltd.”
20 parts by weight of titanium dioxide “Tai Pure R-108, manufactured by DuPont”
Foaming aid “ADK STAB OF-101, manufactured by ADEKA Corporation” 5 parts by weight,
It was formed with 1 part by weight of a crosslinking aid “OPSTAR JUA702, manufactured by JSR Corporation”.

  The non-foamed resin layer B was formed by EVA “Ultrasen 750 (VA content: 32% by weight), manufactured by Tosoh Corporation”.

Example 2
A foamed laminated sheet was obtained in the same manner as in Example 1 except that the electron beam irradiation amount was 195 kV and 50 KGy.

Example 3
A foamed laminated sheet was obtained in the same manner as in Example 1 except that the backing paper was changed to “WK-665DO (manufactured by Kojin Co., Ltd.)” instead of “CP-65PDK (manufactured by Chuetsu Pulp Industries Co., Ltd.)”. .

Example 4
A foamed laminated sheet was obtained in the same manner as in Example 3 except that the electron beam irradiation amount was 195 kV and 50 KGy.

Example 5
The non-foamed resin layer A was formed of an ethylene- (meth) acrylic acid copolymer “Nucleel N1560 (MAA content: 15% by weight), manufactured by Mitsui DuPont Polychemical Co., Ltd.”.
The foaming agent-containing resin layer
EVA "Ultrasen 633 (VA content: 20% by weight), manufactured by Tosoh Corporation" 100 parts by weight,
5 parts by weight of petroleum resin “Alcon P-100, manufactured by Arakawa Chemical Industries, Ltd.”
4 parts by weight of a foaming agent “Vinihole AC # 3, Eiwa Kasei Kogyo Co., Ltd.”
30 parts by weight of calcium carbonate “Whiteon H, average particle size: 22 μm, manufactured by Shiroishi Kogyo Co., Ltd.”
20 parts by weight of titanium dioxide “Tai Pure R-108, manufactured by DuPont”
Foaming aid “ADK STAB OF-101, manufactured by ADEKA Corporation” 5 parts by weight,
It was formed with 1 part by weight of a crosslinking aid “OPSTAR JUA702, manufactured by JSR Corporation”.
As the backing paper, “WK-665DO (manufactured by Kojin Co., Ltd.)” was used.
A foamed laminated sheet was produced in the same manner as in Example 1 except for the above conditions.

Example 6
A foamed laminated sheet was produced in the same manner as in Example 1 except that the electron beam was irradiated not from the non-foamed resin layer A side but from the non-foamed resin layer B side.

Example 7
Without forming the non-foamed resin layer A, using a two-type two-layer multi-manifold T-die extruder, the foaming agent-containing resin layer / the non-foamed resin layer B are extruded to form a film having a thickness of 80 μm / 10 μm and foamed. A foamed laminated sheet was produced in the same manner as in Example 1 except that a laminate composed of the agent-containing resin layer / non-foamed resin layer B was obtained.

Example 8
A foaming agent-containing resin was prepared in the same manner as in Example 1 except that the non-foaming resin layers A and B were provided and the T-die extruder was used to perform extrusion film formation so that the thickness of the foaming agent-containing resin layer was 90 μm. A layer was obtained. Next, in the same manner as in Example 1, cooling of the foaming agent-containing resin layer, slitting and electron beam irradiation were performed. Furthermore, after preparing a paper-based substrate (backing paper) “CP-65PDK (manufactured by Chuetsu Pulp Co., Ltd.)” and heating it to 140 ° C., a foaming agent-containing resin layer is laminated, thereby containing a foaming agent. A raw material for a foamed laminated sheet comprising a resin layer / paper-based substrate was obtained. A foamed laminated sheet was produced in the same manner as in Example 1 except for the above conditions.

Example 9
A foamed laminated sheet was obtained in the same manner as in Example 1 except that when the electron beam was irradiated, both ends of the laminate were fixed with a tenter clip and the electron beam (195 kV, 50 KGy) was irradiated.

Comparative Example 1
After extruding and forming the backing paper in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B, the same procedure as in Example 1 was performed except that the electron beam was irradiated from the non-foamed resin layer A side. A foam laminate sheet was prepared.

Comparative Example 2
After extruding the backing paper in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B, and then irradiating an electron beam from the non-foamed resin layer A side, the same as in Example 2 A foam laminate sheet was prepared.

Comparative Example 3
After extruding the backing paper in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B, and then irradiating an electron beam from the non-foamed resin layer A side, the same as in Example 3 A foam laminate sheet was prepared.

Comparative Example 4
Except that the film was extruded on the backing paper in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B, and then irradiated with an electron beam from the non-foamed tree / BR> 苑 WA side. A foamed laminated sheet was produced in the same manner.

Comparative Example 5
After extruding the backing paper in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B, and then irradiating an electron beam from the non-foamed resin layer A side, the same as in Example 5 A foam laminate sheet was prepared.

Test example 1
About the foaming laminated sheet produced in Examples 1-4, 6-9, and Comparative Examples 1-4, the discoloration degree after foaming was evaluated. The results are shown in Table 1 below.

  The test method and evaluation criteria for discoloration evaluation are as follows.

The color difference (ΔE) viewed from the resin layer side of the foamed laminated sheet before and after the heat foaming was examined. ΔE was calculated using equation (1) by measuring L *, a *, b * using a Minolta color difference meter (CR-300). L *, a *, and b * are measurement data, and L * _t , a * _t , and b * _t are color difference reference colors.

ΔE = √ {(L * −L * _t ) ² + (a * −a * _t ) ² + (b * −b * _t ) ² } (1)
The results are shown in Table 1 below.

Test example 2
The folding resistance of the foamed laminated sheets produced in Example 5 and Comparative Example 5 was examined. The results are shown in Table 2 below.

  The folding resistance was evaluated by a test method defined in JIS P8115. In addition, in the said test, the frequency | count until a crack arises on a paper surface was evaluated.

Claims (6)

The manufacturing method of a foaming lamination sheet which contains the following (1)-(4) processes in order:
(1) The process of forming the laminated body which has a foaming agent containing resin layer or a foaming agent containing resin layer,
(2) A step of irradiating an electron beam to the laminate having the foaming agent-containing resin layer or the foaming agent-containing resin layer,
(3) A step of laminating a paper-based substrate on the foaming agent-containing resin layer or a laminate having a foaming agent-containing resin layer, and (4) a step of heating and foaming the foaming agent-containing resin layer. The manufacturing method of the foaming lamination sheet of Claim 1 which fixes the edge part of the laminated body which has the said foaming agent containing resin layer or a foaming agent containing resin layer in the said (2) process, and irradiates an electron beam. The manufacturing method of the foaming lamination sheet of Claim 1 or 2 which forms the laminated body which consists of the non-foaming resin layer A, the said foaming agent containing resin layer, and the non-foaming resin layer B in the said (1) process. The said foaming agent containing resin layer is a manufacturing method of the foaming lamination sheet in any one of Claims 1-3 containing at least 1 sort (s) chosen from the group which consists of polyethylene and an ethylene copolymer as a resin component. The manufacturing method of the foaming lamination sheet in any one of Claims 1-4 including the process of heating a paper-like base material before the said (3) process. The foam lamination according to any one of claims 1 to 5, comprising a step of performing a decoration treatment on the foaming agent-containing resin layer or the laminate after the step (3) or after the step (4). Sheet manufacturing method.

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