JP2010084274A - Foamed wallpaper and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide foamed wallpaper with unevennesses patterned by electronic irradiation and heating only, without pressure-shaping after foamed or printing foamable printing ink, and to provide a method for producing the same. <P>SOLUTION: The method for producing foamed wallpaper with unevennesses on the surface includes consecutively: (1) the step of forming a foaming agent-containing resin layer on a paper substrate; (2) the step of irradiating the foaming agent-containing resin layer with electron beams via a mask having an electron beam-transmitting area and an electron beam-non-transmitting area to form an electron beam-irradiated area and an electron beam-non-irradiated area on the foaming agent-containing resin layer; and (3) the step of heating and foaming the foaming agent-containing resin layer subjected to the step (2). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to foamed wallpaper useful for wall decoration and a method for producing the same.

  As the layer structure of the foamed wallpaper, a foamed resin layer is provided on a paper base material via an adhesive layer (non-foamed resin layer B), and further, the foamed resin layer is protected in order to protect the foamed resin layer and increase the surface strength. A configuration in which A is provided is common. The foamed resin layer is generally obtained by forming a foaming agent-containing resin layer containing a thermally decomposable foaming agent and then thermally foaming the layer. Moreover, in order to ensure the strength of the foamed resin layer, the foaming agent-containing resin layer is often irradiated with an electron beam to be crosslinked with resin and then heated and foamed in many cases.

  Conventionally, foaming wallpaper (foaming decorative sheet) has been shaped by pressure molding with a mold or printing a part of the surface of a foaming agent-containing resin layer by direct or transfer method. After performing foaming suppression by doing, the chemical shaping which gives an uneven | corrugated pattern to the surface by making the whole foam is known.

  For example, Patent Document 1 discloses a method of forming irregularities by partially forming a foam suppression portion by providing a resin having a specific gravity larger than that of a resin to be foamed by a calorific difference method.

  On the other hand, electron beam irradiation is used for the production of foam wallpaper for the purpose of crosslinking, curing, and destruction.

Therefore, it is desired to develop a foamed wallpaper in which irregularities are formed by omitting the manufacturing process by being able to be manufactured without pressure forming after foaming or without printing the foam suppression ink.
JP-A-9-193276

  The main object of the present invention is to provide a foamed wallpaper in which irregularities patterned by only electron beam irradiation and heating are formed without pressurizing after foaming or printing a foam-suppressing ink, and a method for producing the same. Objective.

  As a result of earnest research, the present inventor has produced a foamed wallpaper in which irregularities are formed by heating and foaming after part of the foaming agent-containing resin layer is masked and partly cured by electron beam irradiation. In this case, the present inventors have found that the above object can be achieved and have completed the present invention.

That is, this invention relates to the following foam wallpaper and its manufacturing method.
Item 1. A method for producing a foam wallpaper having a concavo-convex shape on the surface, the method comprising:
Forming a foaming agent-containing resin layer on the paper substrate (1),
Step (2) of forming an electron beam irradiation region and an electron beam non-irradiation region on the foaming agent-containing resin layer by performing electron beam irradiation through a mask having an electron beam transmission region and an electron beam non-transmission region. And the process (3) which heats and foams the said foaming agent containing resin layer which passed through the said process (2).
The manufacturing method which has these in order.
Item 2. The manufacturing method of claim | item 1 which forms the non-foaming resin layer A further on the said foaming agent containing resin layer in the said process (1).
Item 3. Item 3. The production method according to Item 1 or 2, wherein a non-foamed resin layer B is further formed between the paper base and the foaming agent-containing resin layer in the step (1).
Item 4. The foaming wallpaper manufactured with the manufacturing method in any one of claim | item 1-3.

  Hereinafter, the foamed wallpaper and the method for producing the same according to the present invention will be described in detail.

<Method for producing foam wallpaper>
The method for producing a foamed wallpaper having a concavo-convex shape on the surface of the present invention includes the step (1) of forming a foaming agent-containing resin layer on a paper-based substrate, through a mask having an electron beam transmitting region and an electron beam non-transmitting region. The step (2) of forming an electron beam irradiation region and an electron beam non-irradiation region on the foaming agent-containing resin layer by performing electron beam irradiation, and the foaming agent-containing resin layer that has undergone the step (2) It is a manufacturing method which has the process (3) heated and foamed in order.

  According to the production method of the present invention having the above characteristics, an electron beam is passed through a mask having an electron beam transmission region and an electron beam non-transmission region without performing pressure forming after foaming or printing the foam suppression ink. Patterned unevenness can be formed only by irradiation and heating.

  Steps (1) to (3) of the production method of the present invention are as follows.

Process (1)
The method for forming the foaming agent-containing resin layer on the paper substrate in the step (1) 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, and this is the sheet surface. It is easy to become a foreign material. 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.

Process (2)
In the step (2), the foaming agent-containing resin layer is then irradiated with an electron beam through a mask having an electron beam transmission region and an electron beam non-transmission region. Thereby, the expansion ratio can be changed by patterning the resin-crosslinked portion and the resin-crosslinked portion. The energy of the electron beam is preferably about 150 to 250 kV. The irradiation amount is preferably about 50 to 150 kGy. A known electron beam irradiation apparatus can be used as the electron beam source.

  The mask (electron beam blocking plate) has a structure that transmits an electron beam in an electron beam transmission region (through hole) and blocks the electron beam in a portion that becomes an electron beam non-transmission region (mask part). That's fine. The material is not particularly limited as long as it can block an electron beam. For example, a metal plate (lead or the like) having a large specific gravity or a plate material (paper or the like) having a thickness that cannot be transmitted by the acceleration voltage is used.

  From the viewpoint 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.

Step (3)
In the step (3), by heating the foaming agent-containing resin layer, the expansion ratio of the resin-crosslinked portion is suppressed, and in the non-resin-crosslinked portion, the desired expansion ratio is obtained and irregularities are formed. 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 240 ° C., and the heating time is preferably about 20 to 80 seconds.

  When a surface protective layer containing an ionizing radiation curable resin is formed, the surface protective layer can be cured by electron beam irradiation.

  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 later.

<Foam wallpaper>
The composition of the foam wallpaper produced by the present invention is as follows.

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 5 to 50 μm, more preferably about 5 to 15 μm.

Foamed resin layer The foamed resin layer is placed on the foaming agent-containing resin layer by placing a mask having an electron beam transmitting region and an electron beam non-transmitting region on the foaming agent-containing resin layer and performing electron beam irradiation through the mask. After the electron beam irradiation region and the electron beam non-irradiation region are formed, the layer is formed by heating and foaming.

  The resin component contained in the foaming agent-containing resin layer is not limited, but it is preferable to use a resin obtained from a combination of monomers that does not contain hydrogen bonds. For example, an ethylene copolymer resin obtained from a combination of ethylene and a monomer having no OH group or COOH group can be suitably used. From this viewpoint, examples of the ethylene copolymer resin include ethylene-vinyl acetate copolymer resin (hereinafter abbreviated as “EVA”), ethylene-methyl methacrylate (EMMA), ethylene-ethyl acrylate (EEA), ethylene-methyl. Acrylate (EMA) or the like can be used. In particular, it is desirable that the resin component is formed of a resin composition containing EVA resin.

  When EVA resin is used as the resin component, the vinyl acetate content (copolymerization ratio) of the EVA resin is not limited, but is preferably about 5 to 30% by weight, more preferably about 10 to 20% by weight. .

  The melt flow rate value (MFR) of the resin component is not particularly limited, but is preferably about 5 to 75 g / 10 minutes, and more preferably about 10 to 30 g / 10 minutes.

  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.

  The foaming agent-containing resin layer of the present invention contains a pyrolytic foaming agent, and 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 can be appropriately set according to the type of foaming agent, the expansion ratio, and the like.

  The foaming agent-containing resin layer may contain a known additive as long as the effects of the present invention are not hindered. For example, inorganic fillers, pigments, foaming aids and the like can be mentioned.

  As the foaming aid, for example, a metal soap such as zinc stearate can be used. The content of the foaming aid is 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 inorganic filler include calcium carbonate, titanium dioxide, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound. By including an inorganic filler, an effect of suppressing see-through, an effect of improving surface characteristics, and the like are obtained. About 0-100 weight part is preferable with respect to 100 weight part of resin components, and, as for content of an inorganic filler, about 20-70 weight part is more preferable.

  As for the pigment, 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, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, and zinc sulfide; for example, aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), many Cyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, perylene, diketopyrrolopyrrole, dibromanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone And organic pigments halogenated phthalocyanine), or the like. The content of the pigment is preferably about 10 to 50 parts by weight and more preferably about 15 to 30 parts by weight with respect to 100 parts by weight of the resin component.

  The foaming agent-containing resin layer is heated and foamed after forming an electron beam irradiation region and an electron beam non-irradiation region by performing electron beam irradiation through a mask having an electron beam transmission region and an electron beam non-transmission region. By doing so, it becomes a foamed resin layer. Thus, resin bridges are selectively formed in the foaming agent-containing resin layer by creating the electron beam irradiation region and the non-irradiation region. As a result, the expansion ratio can be changed between the region where the resin crosslink is formed and the region where the resin crosslink is not formed. What is necessary is just to implement in accordance with the method described in the said manufacturing method about the procedure of electron beam irradiation and heating foaming.

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. The resin component contained in the non-foamed resin layer A is not limited. For example, ethylene-vinyl acetate copolymer resin (EVA), ethylene-methyl methacrylate (EMMA), ethylene-ethyl acrylate (EEA), ethylene-methyl acrylate (EMA) or the like can be used.

In the present invention, among the above, 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. The formed layer 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.

  The thickness of the non-foamed resin layer is not limited, but is preferably about 5 to 50 μm, more preferably about 5 to 15 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.

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 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 pattern 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, known pigments or dyes 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 the present invention, the design can be further enhanced by applying an embossed pattern. 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.

  The method for producing foamed wallpaper according to the present invention includes irradiation with an electron beam and heating through a mask having an electron beam transmission region and an electron beam non-transmission region, without pressure forming after foaming or printing the foam suppression ink. It is possible to form unevenness patterned only by the above. Therefore, the method for producing foamed wallpaper of the present invention has a smaller number of production steps than the conventional shaping method.

  Furthermore, the foamed wallpaper obtained by the production method of the present invention has a sharp edge, a clear unevenness, and a three-dimensional design.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

Example 1
A foamed wallpaper in which a non-foamed resin layer B, a foamed resin layer, and a non-foamed resin layer A were laminated on a paper-based substrate (product number “WK665DO”, manufactured by Kojin Co., Ltd., thickness 110 μm) was produced.

  The composition of the foaming agent-containing resin layer for forming the foamed resin layer was as shown in Table 1 below.

  The composition of the non-foamed resin layer A was 100% EMAA (trade name “Nucrel” product name “N1560”).

  The composition of the non-foamed resin layer B was 100% EVA (trade name “Evaflex” product name “EV150”).

  The foam wallpaper was produced by the following procedure.

  A composition for forming a foaming agent-containing resin layer, a composition for forming the non-foamed resin layer A, and a composition for forming the non-foamed resin layer B are heated and melted, and three layers are coextruded. Thus, a laminate was formed on the paper substrate. The laminate was a paper-based substrate (110 μm) / non-foamed resin layer B (8 μm) / foaming agent-containing resin layer (90 μm) / non-foamed resin layer A (8 μm).

  The laminated body was covered with a patterned mask (thickness: 2000 μm) and irradiated with an electron beam from the resin layer side. Irradiation conditions were acceleration voltage: 195 kV, irradiation amount: 30 kGy × 3 times.

  Finally, foaming was performed by heating and foaming in a gear oven at 220 ° C. for 45 seconds to obtain a foamed wallpaper.

  When the produced foamed wallpaper was visually evaluated, the unevenness difference was clear and could be recognized as a design. The unevenness difference was 350 μm.

Claims (4)

A method for producing a foam wallpaper having a concavo-convex shape on the surface, the method comprising:
Forming a foaming agent-containing resin layer on the paper substrate (1),
Step (2) of forming an electron beam irradiation region and an electron beam non-irradiation region on the foaming agent-containing resin layer by performing electron beam irradiation through a mask having an electron beam transmission region and an electron beam non-transmission region. And the process (3) which heats and foams the said foaming agent containing resin layer which passed through the said process (2).
The manufacturing method which has these in order.   The manufacturing method of Claim 1 which forms the non-foaming resin layer A further on the said foaming agent containing resin layer in the said process (1).   The manufacturing method according to claim 1 or 2, wherein a non-foamed resin layer B is further formed between the paper base and the foaming agent-containing resin layer in the step (1).   The foam wallpaper manufactured with the manufacturing method in any one of Claims 1-3.