JP2008069480A - Method for producing foamed wallpaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for production in order to produce at a low cost a high-quality foamed wallpaper having excellent scratch resistance while effectively preventing yellowing. <P>SOLUTION: The method for producing the foamed wallpaper includes (1) a step 1 for forming a laminate composed of a first non-foamed resin layer, a foaming agent-containing resin layer and a second non-foamed resin layer by melt-extrusion molding, (2) a step 2 for trimming a part of the laminate formed in the step 1 and (3) a step 3 for feeding trimming pieces obtained in the step 2 as the resin composition for forming the foaming agent-containing resin layer to the step 1. (A) The second non-foamed resin layer contains an ethylene-methacrylic acid copolymer resin containing 10-15 wt.% of methacrylic acid and (B) the foaming agent-containing resin layer contains azodicarbonamide. (C) The trimming pieces are fed to the step 1 so that the content of the ethylene-methacrylic acid copolymer resin is ≤1 wt.% in the foaming agent-containing resin layer in the step 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for producing foamed wallpaper.

Conventionally, foamed wallpaper in which a foamed resin layer made of a vinyl chloride resin is formed on a paper base (backing paper) is known. In recent years, in consideration of the environment, resins that do not contain halogen such as ethylene-vinyl acetate copolymer resin, acrylic resin, and olefin resin have been used for the foamed resin layer (Patent Documents 1 to 3). .
For example, a foamed wallpaper is formed by laminating a laminate obtained by co-extrusion molding of a non-foamed resin layer, a foaming agent-containing resin layer, and an adhesive layer on a paper substrate, and 1) form a pattern pattern layer. It can be manufactured through a process, 2) a process of forming a foamed resin layer, and 3) a process of shaping an embossed pattern.

  When a laminate is manufactured by three-layer coextrusion molding, bulges are generated at both ends of the laminate (extruded from the end of the die). Therefore, it is necessary to trim the bulges and then laminate them on a paper substrate. .

  In view of the manufacturing cost of foamed wallpaper, there is an urgent need to effectively use trimmed pieces that have been discarded.

  On the other hand, azodicarbonamide (hereinafter sometimes abbreviated as “ADCA”) is widely used as a foaming agent for the foaming agent-containing resin layer. In addition, as a constituent resin of the non-foamed resin layer (surface protective layer), an ethylene-methacrylic acid copolymer resin (hereinafter referred to as “EMAA”) may be given in that it can provide excellent scratch resistance to foamed wallpaper. Is used).

However, when a trimming piece containing EMAA is supplied as a resin composition for forming a foaming agent-containing resin layer containing ADCA, EMAA (the carboxyl group thereof) reacts with ADCA, and this reaction causes the foamed resin layer. Is prone to yellowing. Further, when the foaming agent-containing resin layer further contains a zinc compound as a foaming aid, a cell adjusting agent and the like in addition to ADCA, the resulting foamed wallpaper is more easily yellowed.
Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A

  The main object of the present invention is to provide a manufacturing method for manufacturing foamed wallpaper having excellent scratch resistance at low cost and effectively preventing yellowing.

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

That is, this invention relates to the manufacturing method of the following foam wallpaper.
1. (1) A step of forming a three-layer laminate comprising a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer by melt extrusion molding a resin composition for forming each layer. 1,
(2) Step 2 for trimming a part of the laminate formed in Step 1;
(3) Step 3 for supplying the trimming piece obtained in Step 2 to Step 1 as a resin composition for forming the foaming agent-containing resin layer,
A method for producing foam wallpaper comprising:
(A) The second non-foamed resin layer contains an ethylene-methacrylic acid copolymer resin having a methacrylic acid content of 10 to 15% by weight,
(B) the foaming agent-containing resin layer contains azodicarbonamide,
(C) In step 3, the trimming piece is supplied to step 1 so that the content of the ethylene-methacrylic acid copolymer resin in the foaming agent-containing resin layer is 1% by weight or less.
A method for producing foam wallpaper.
2. Item 2. The production method according to Item 1, wherein the foaming agent-containing resin layer further contains a zinc compound.

The foamed wallpaper manufacturing method of the present invention is particularly advantageous in the following points (1) to (4). (1) When melt extrusion molding is performed, swelling occurs at the portion extruded from the end of the die of the laminate. The manufacturing method of the present invention makes it possible to manufacture foamed wallpaper at a low cost by trimming the bulge and reusing the obtained trimming piece.
(2) The foamed wallpaper obtained by the production method of the present invention has a surface protective layer whose constituent resin is EMAA. Therefore, the foamed wallpaper obtained by the production method of the present invention has excellent scratch resistance.
(3) According to the production method of the present invention, the problem of yellowing due to the reaction of EMAA and ADCA can be effectively solved.
(4) In the production method of the present invention, the foaming agent-containing resin layer may further contain a zinc compound as a foaming aid, a cell adjusting agent and the like. According to the production method of the present invention, the problem of yellowing due to the reaction between EMAA and a zinc compound can be effectively solved.

The method for producing foamed wallpaper according to the present invention includes: (1) a resin composition for forming each layer of a three-layer laminate comprising a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer. Step 1 for forming by melt extrusion molding, (2) Step 2 for trimming a part of the laminate formed by Step 1, and (3) Trimming piece obtained by Step 2 is used as the foaming agent-containing resin. A foamed wallpaper manufacturing method comprising: Step 3 which is supplied to Step 1 as a resin composition for forming a layer, wherein (A) the second non-foamed resin layer has a methacrylic acid content of 10 to 15% by weight. (B) the foaming agent-containing resin layer contains azodicarbonamide, and (C) in step 3, the ethylene-methacrylic acid copolymer resin in the foaming agent-containing resin layer is included. Content is 1% by weight or less So as to supply said trimming piece in Step 1.
In the production method of the present invention, the above steps 1 to 3 may be repeated in order. Specifically, first, as a first round, a laminated body is manufactured through the above-described Step 1 and Step 2. Then, the trimming piece obtained in the first round is used in the process 1 of the second round, and the trimming piece obtained in the second round is used in the process 1 of the third round to produce the foam wallpaper. In the production method of the present invention, it is particularly preferred to produce a foam wallpaper using a laminate obtained after the third round. Usually, by supplying trimming pieces as a resin composition for forming a foaming agent-containing resin layer, it is difficult to reproduce a foaming agent-containing resin layer of the same quality (having the same configuration). According to the production method of the present invention, a laminate having the same foaming agent-containing resin layer can be effectively reproduced after the third round.

  The first non-foamed resin layer to the second non-foamed resin layer are not particularly limited as long as they are resin layers not intended to be foamed.

Hereinafter, the first non-foamed resin layer is an adhesive layer for improving the adhesion between the paper-based substrate and the foaming agent-containing resin layer, and the second non-foamed resin layer is for improving the scratch resistance of the foam wallpaper. The production method of the present invention will be specifically described as the surface protective layer.
When a three-layer laminate comprising a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer is produced by three-layer coextrusion molding, a bulge occurs at the portion extruded from the end of the die. . A laminate having such a bulge (non-uniform thickness) is not suitable for laminating on a paper-based substrate.
In the manufacturing method of the present invention, the bulge is trimmed. And the trimming piece obtained by the said trimming is supplied as a resin composition for forming a foaming agent containing resin layer.

In the production method of the present invention, the foaming agent-containing resin layer contains ADCA. A foamed resin layer can be formed by foaming ADCA. In the production method of the present invention, the foaming agent-containing resin layer may further contain a zinc compound. When the foaming agent-containing resin layer further contains a zinc compound, ADCA can be more suitably foamed. A foamed resin layer having a dense and uniform cell shape can also be formed.
In the production method of the present invention, EMAA is used as a resin component for forming the surface protective layer (second non-foamed resin layer). Thereby, the foaming wallpaper excellent in scratch resistance can be manufactured.

The methacrylic acid content in the EMAA is 10 to 15% by weight, preferably 12 to 15% by weight. When the methacrylic acid content is 10 to 15% by weight, yellowing of the foamed wallpaper can be effectively prevented.
In the production method of the present invention, the trimming piece is supplied to step 1 so that the content of EMAA in the foaming agent-containing resin layer is 1% by weight or less, preferably 0.01 to 0.9% by weight. When the content of EMAA is 1% by weight or less, yellowing of the foam wallpaper can be effectively prevented.

  Hereinafter, the manufacturing method of the present invention will be described in detail with reference to FIG. In FIG. 1, the outline | summary of an example of the manufacturing method of this invention is shown.

Process 1
In step 1, a three-layer laminate comprising a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer is formed by melt extrusion molding a resin composition for forming each layer. .

  The melt extrusion is performed by simultaneously extruding three layers in the order of the first non-foamed resin layer, the foaming agent-containing resin layer, and the second non-foamed resin layer. Thereby, a three-layer laminate including the first non-foamed resin layer, the foaming agent-containing resin layer, and the second non-foamed resin layer is obtained.

(I) First non-foamed resin layer The first non-foamed resin layer is obtained by applying the resin composition in the first non-foamed resin layer raw material tank 1 to the multi-manifold T-die using the first non-foamed resin layer extruder 5. 8 is formed by melt extrusion molding.

  Examples of the resin component constituting the first non-foamed resin layer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene- Examples include at least one of methyl acrylate copolymer (EMA) and the like. Among these, EVA is particularly preferable.

If it is a range which does not prevent the effect of this invention, you may contain a well-known additive.
As known additives, for example, metal soap such as zinc stearate and magnesium stearate, polyethylene wax and the like can be used. These can be used alone or in combination of two or more.

  From the viewpoint of ease of bonding with a paper-based substrate, the melt flow rate value (hereinafter abbreviated as “MFR”) of the resin composition of the first non-foamed resin layer is the value of the resin composition of the foaming agent-containing resin layer. It is preferably greater than MFR. The MFR can be measured by a test method described in JIS K 7210 (thermoplastic flow test method). As test conditions, “190 ° C., 21.18 N (2.16 kgf)” described in JIS K 6760 is adopted.

  In particular, when the resin composition contains the additive, it is preferable that the resin composition in the raw material tank 1 is sufficiently mixed and dispersed. Mixing / dispersing may be performed by a mixer, a blender or the like.

  Although the thickness of the 1st non-foaming resin layer formed is not limited, about 5-20 micrometers is preferable and about 10-15 micrometers is more preferable.

(Ii) Foaming agent-containing resin layer The foaming agent-containing resin layer before performing Step 2 and Step 3 described below is the foaming agent-containing resin layer extruder 7 for the resin composition in the foaming agent-containing resin layer raw material tank 3. Thus, it is formed by melt extrusion molding through a T die 8.
As a resin component which comprises a foaming agent containing resin layer, EMAA, EVA, EMMA, EEA, EMA etc. are mentioned, for example. Among these, EVA is particularly preferable.

  The foaming agent-containing resin layer contains ADCA. ADCA acts as a foaming agent and is stable at room temperature, but releases foaming gas mainly composed of nitrogen gas, carbon dioxide gas and carbon monoxide gas when exposed to high temperature of 190 ° C or higher. Is. As such, in addition to ADCA alone, an ADCA foaming agent can be used. A well-known or commercially available ADCA type foaming agent can be used.

  The content of ADCA can be adjusted according to the type, the desired expansion ratio, and the like. Usually, about 1-20 weight part is preferable with respect to 100 weight part of resin of a foaming agent containing resin layer.

  Moreover, you may use a well-known thermal decomposition type foaming agent with ADCA. Examples of known pyrolytic foaming agents include azo series such as azobisformamide; and birazazide series such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. These can be used alone or in combination of two or more.

  The foaming agent-containing resin layer may further contain a known additive. Examples of known additives include foaming aids, inorganic fillers, fluidity modifiers, pigments, cell regulators, crosslinking aids, and the like. These can be used alone or in combination of two or more.

  Examples of the foaming aid include zinc oxide, zinc stearate, salicylic acid, phthalic acid, and oxalic acid. In particular, according to the production method of the present invention, the problem of yellowing when a zinc compound is used can be effectively solved.

  Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, and a molybdenum compound. These can be used alone or in combination of two or more.

  Examples of the fluidity modifier include petroleum resin and polyethylene wax.

  Examples of the pigment include the following. Examples of inorganic pigments include titanium oxide, 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, and ultramarine blue. , Bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica and the like. Examples of the organic pigment include aniline black, perylene black, azo type (azo lake, insoluble azo, condensed azo), polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, Perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halogenated phthalocyanine) and the like. These can be used alone or in combination of two or more.

  Examples of the cell regulator include metal soaps and zinc compounds. These can be used alone or in combination of two or more. Among these, a zinc compound is particularly preferable. Examples of the zinc compound include zinc stearate, zinc octylate, zinc white and the like. In particular, according to the production method of the present invention, the problem of yellowing when a zinc compound is used can be effectively solved.

Examples of the crosslinking aid include acrylic monomers. As addition amount of a crosslinking adjuvant, 10 weight part or less is preferable with respect to 100 weight part of resin of a foaming agent containing resin layer, and 1-4 weight part is more preferable.
Although MFR of the resin composition of a foaming agent containing resin layer is not specifically limited, 20-60 g / 10min is preferable.

It is preferable that the resin composition in the raw material tank 3 is sufficiently mixed and dispersed. Mixing / dispersing may be performed by a mixer, a blender or the like.
In mixing and dispersing, the temperature of the resin composition is preferably 10 to 40 ° C. By setting the temperature of the resin composition within the above range, blockage of the inlet portion of the extruder 7 can be effectively prevented. That is, melting of the resin composition near the inlet of the extruder 7 can be suppressed.

  Although the thickness of the foaming agent containing resin layer formed is not limited, about 10-200 micrometers is preferable.

(Iii) Second non-foamed resin layer The second non-foamed resin layer is obtained by applying the resin composition in the second non-foamed resin layer raw material tank 2 to the multi-manifold T-die using the second non-foamed resin layer extruder 6. 8 is formed by melt extrusion molding.

As a resin component for constituting the second non-foamed resin layer, EMAA having an ethylene methacrylic acid content of 10 to 15% by weight is used. The content of EMAA is not particularly limited as long as it is within a range that can impart excellent scratch resistance to foamed wallpaper, but is preferably 70 to 100% by weight.
As a resin component, in addition to EMAA, EVA, EMMA, EEA, EMA, linear low density polyethylene (LLDPE), or the like may be included as necessary.

If it is a range which does not prevent the effect of this invention, you may contain a well-known additive.
As the known additive, for example, the same additives as described in the above (i) can be used.
The MFR of the resin composition of the second non-foamed resin layer is preferably higher than the MFR of the foaming agent-containing resin layer.

  In particular, when the resin composition contains the additive, it is preferable that the resin composition in the raw material tank 2 is sufficiently mixed and dispersed. Mixing / dispersing may be performed by a mixer, a blender or the like.

  Although the thickness of the 2nd non-foaming resin layer formed is not limited, about 5-30 micrometers is preferable and about 10-20 micrometers is more preferable.

Process 2
In step 2, a part of the laminate formed in step 1 is trimmed. That is, the laminated body obtained through the T die 8 is sent to the trimming unit 9 to trim a part of the laminated body. In the manufacturing method of the present invention, it is preferable to trim the bulging portions (so-called ears) at both ends in the direction perpendicular to the direction of extrusion by extrusion.

  The trimming piece is usually a three-layer laminate composed of a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer. There is no need to be limited. For example, the trimming piece may be a laminate composed of at least one or two selected from a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer.

  Trimming may be performed by known means. For example, a predetermined portion may be excised using a score cutter, a shear cutter, or the like.

Process 3
In step 3, the trimming piece obtained in step 2 is supplied to step 1 as a resin composition for forming the foaming agent-containing resin layer. That is, the trimming piece is sent to the regeneration granulator 10 and granulated as necessary, and then the obtained granulated product is supplied to the regeneration raw material tank 4. In particular, it is preferable to sufficiently knead when granulating with the regenerating granulator 10. The size of the granulated product can be appropriately set to such an extent that desired fluidity can be obtained according to the type of material.

  Note that the trimming pieces may be crushed by a crusher (not shown) before being sent to the regenerating granulator 10.

  Then, the resin composition is supplied from the foaming agent-containing resin layer raw material tank 3 to the foaming agent-containing resin layer extruder 7, and further, all or a part of the resin composition in the recycled raw material tank 4 is supplied. To form a foaming agent-containing resin layer. In particular, in the manufacturing method of the present invention, the trimming piece is supplied so that the content of EMAA in the foaming agent-containing resin layer is 1% by weight or less.

  In addition, when supplying the trimming piece as a resin composition for forming the first non-foamed resin layer, due to a residue (filler or the like) such as a resin composition adhering to the die outlet during melt extrusion, The first non-foamed resin layer cannot be formed stably. Similarly, when the trimming piece is supplied as a resin composition for forming the second non-foamed resin layer, the second non-foam is stably produced due to residues (fillers, etc.) adhering to the die outlet. A resin layer cannot be formed. Moreover, the intended scratch resistance, wear resistance, etc. cannot be obtained.

In the foamed wallpaper paper-based base material laminating unit 11, a partially trimmed laminated body is stacked on the paper base so that the paper base and the first non-foamed resin layer are in contact with each other.

  The paper-based substrate is supplied from the substrate feeding unit.

  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 fibrous 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.

  After lamination, if necessary, the electron beam irradiation unit 12 irradiates the electron beam (200 KV, 30 KGy) from above the first non-foamed resin layer to crosslink the resin component contained in the first non-foamed resin layer. .

  If necessary, a pattern layer or the like may be formed on the second non-foamed resin layer.

  The pattern layer includes, for example, 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, an abstract pattern, etc. Can be mentioned. The pattern can be selected according to the type of foam wallpaper.

  The pattern pattern layer is formed, for example, by printing a pattern pattern on the front surface of the non-foamed resin layer. Examples of printing methods include gravure printing, flexographic printing, silk screen printing, and offset printing. As the printing ink, a known printing ink containing a colorant, a vehicle and a solvent can be used.

  The obtained raw material for foamed wallpaper is wound up by the raw material winding portion for foamed wallpaper.

  A foamed wallpaper is obtained by heating the foaming agent-containing resin layer of the raw fabric for the foamed wallpaper.

  The heating temperature is preferably about 180 to 240 ° C, more preferably about 210 to 230 ° C. The heating time is preferably about 20 to 60 seconds, and more preferably about 25 to 40 seconds.

  The expansion ratio of the foamed resin layer (the ratio as viewed from the foaming agent-containing resin layer) is not particularly limited, but is usually 4 times or more, preferably about 4 to 8 times. If the expansion ratio is too low, it is difficult to give an excellent appearance design. On the other hand, if the expansion ratio is too high, the foamed resin layer becomes mechanically weak, and the scratch resistance tends to decrease.

  The obtained foamed wallpaper may have an embossed pattern as necessary.

  The embossed pattern can be given by, for example, a known embossed plate. For example, a desired embossed pattern can be formed by pressing the embossed plate after heating and softening the front surface of the foamed resin layer. Embossed patterns include wood grain plate conduit grooves, stone plate surface irregularities, cloth surface textures, satin texture, sand texture, hair lines, and multi-line grooves.

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

  According to the flow of FIG. 1, an original material for foam wallpaper was prepared, and a foam wallpaper was manufactured using the original material.

Example 1
First round (foaming agent-containing resin layer)
In order to form the foaming agent-containing resin layer, the raw materials shown in Table 1 below were mixed at the ratios shown in Table 1, and supplied to the foaming agent-containing resin layer extruder 7 and melt-extruded. The melt extrusion was performed under the condition of a cylinder temperature of 110 ° C. As the extruder 7, a single screw extruder (Φ100 mm) was used.

(First non-foamed resin layer (adhesive layer))
In order to form the first non-foamed resin layer, 100 parts by weight of EVA (product name “Evaflex EV150” MFR: 30 g / 10 min, VA content: 33% by weight, manufactured by Mitsui DuPont Polychemical) was extruded 5 And melt extruded. Melt extrusion was performed under the condition of a cylinder temperature of 100 ° C. As the extruder 5, a single screw extruder (Φ50 mm) was used.

(Second non-foamed resin layer (surface protective layer))
In order to form the second non-foamed resin layer, 100 parts by weight of EMAA (product name “Nucleel N1560” MFR: 60 g / 10 min, methacrylic acid content: 15% by weight, manufactured by Mitsui DuPont Polychemical) was added to the extruder 6. Feeded and melt extruded. The melt extrusion was performed under the condition of a cylinder temperature of 115 ° C. As the extruder 6, a single screw extruder (Φ50 mm) was used.

  By passing the melt-extruded resin composition through the T-die 8, a three-layer laminate including a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer was obtained. The die temperature was 110 ° C. for all. Moreover, the thickness of the 1st non-foaming resin layer, the foaming agent containing resin layer, and the 2nd non-foaming resin layer was 10 micrometers, 100 micrometers, and 10 micrometers, respectively.

  After trimming both ends (each about 5 cm) of the obtained laminate by a shear cutting method with a trimming unit 9 equipped with a cutter, the trimming piece was sent to a crusher (not shown) through a suction pipe. The trimming pieces were made into flakes having a size of about 5 mm by a crusher, and then the flakes were sent to the regenerating granulator 10 through a suction pipe to produce regenerated pellets.

  In addition, the reproduction | regeneration granulator 10 used the single screw extruder ((PHI) 95mm, L / D30, one vent port).

Except for supplying the recycled pellets obtained in the first round to the extruder 7 and forming the foaming agent-containing resin layer so that the content of the recycled pellets in the second round foaming agent-containing resin layer is 13% by weight. In the same manner as in the first round, a three-layer laminate including a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer was produced.

  After trimming both ends of the obtained laminate by the same method as in the first round, a recycled pellet was produced from the trimmed pieces in the same manner as in the first round.

The first round except that the recycled pellets obtained in the third round and the second round are supplied to the extruder 7 to form the foaming agent-containing resin layer so that the content of the recycled pellets is 13% by weight. In the same manner as described above, a three-layer laminate including a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer was produced.

(Production of foam wallpaper)
After trimming both ends of the laminate obtained in the third round by the same method as in the first round, the trimmed laminate in the paper base laminate 11 is 110 μm thick and has a basis weight of 70 g (product) The raw material for foamed wallpaper was obtained by laminating on the name “NI-65A” (made by Nippon Paper Industries Co., Ltd.). The lamination was performed such that the paper substrate and the first non-foamed resin layer were in contact with each other while heating the surface temperature of the paper substrate to 90 ° C. The resulting foaming agent-containing resin layer for the foamed wallpaper contained 0.9% by weight of EMAA derived from the second non-foamed resin layer.

Then, EMAA was bridge | crosslinked by irradiating an electron beam (200KV, 3Mrad) from the said 2nd non-foaming resin layer in the electron beam irradiation part 12. FIG. Subsequently, a corona discharge treatment is performed on the second non-foamed resin layer, and 2 g / m ^{2 of} an EVA water-based emulsion is applied as a primer treatment, followed by a water-based ink (product name “Hydric” manufactured by Dainichi Chemical Industries). A texture pattern was printed with a gravure printing machine.

After printing, the obtained foam wallpaper was wound up.
Subsequently, the raw material for foam wallpaper was heated in a foaming furnace at 220 ° C. for 35 seconds. Thereby, the foaming agent was decomposed, and the foaming agent-containing resin layer was used as the foamed resin layer. Furthermore, the embossing was given to the front side of the foam, and the texture pattern was shaped.

  The foamed wallpaper was produced by the above method.

  Table 2 shows the scratch resistance and whiteness of the resulting foamed wallpaper.

Example 2
As EMAA, instead of 100 parts by weight of the product name “Nucrel N1560” (MFR: 60 g / 10 min, methacrylic acid content: 15% by weight, manufactured by Mitsui DuPont Polychemical), the product name “Nucrel N1035” (MFR: 35 g / 10 minutes, methacrylic acid content: 10% by weight, made by Mitsui DuPont Polychemical) 80 parts by weight and product name “Nucleel N1050H” (MFR: 500 g / 10 minutes, methacrylic acid content: 10% by weight, made by Mitsui DuPont Polychemical) ) Foaming was carried out in the same manner as in Example 1 except that 20 parts by weight of the mixed resin (MFR of the mixed resin: 59.6 g / 10 min, methacrylic acid content of the mixed resin: 10%) was supplied to the extruder 6. Made wallpaper.

  Table 2 shows the scratch resistance and whiteness of the resulting foamed wallpaper.

Comparative Example 1
As EMAA, instead of 100 parts by weight of the product name “Nucrel N1560” (MFR: 60 g / 10 min, methacrylic acid content: 15 wt%, Mitsui DuPont Polychemical), the product name “Nucrel AN4214C” (MFR: 7 g / 10 minutes, 50% by weight of methacrylic acid content: 4% by weight, manufactured by Mitsui DuPont Polychemical Co., Ltd. and product name “Nucleel N1050H” (MFR: 500 g / 10 min, methacrylic acid content: 10% by weight, manufactured by Mitsui DuPont Polychemical) ) Foaming was carried out in the same manner as in Example 1 except that 50 parts by weight of the mixed resin (MFR of the mixed resin: 59.2 g / 10 minutes, methacrylic acid content of the mixed resin: 7%) was supplied to the extruder 6. Made wallpaper.

  Table 2 shows the scratch resistance and whiteness of the resulting foamed wallpaper.

Comparative Example 2
Except that the obtained recycled pellets were supplied to the extruder 7 so that the content of the recycled pellets in the foaming agent-containing resin layer was 20% by weight in the second and third rounds, the same as in Example 1 The foamed wallpaper was manufactured by the method.

  In addition, the foaming agent containing resin layer of the raw material for foamed wallpaper before electron beam irradiation contained 1.4% by weight of EMAA derived from the second non-foaming resin layer.

  Table 2 shows the scratch resistance and whiteness of the resulting foamed wallpaper.

Test Example 1 (Scratch resistance)
The scratch resistance of the foamed wallpaper produced in the examples and comparative examples was evaluated.

The tests and evaluations were conducted in accordance with the “Surface-enhanced wallpaper performance regulations” established by the Japan Vinyl Industry Association Vinyl Construction Committee. Specifically, tests and evaluations were performed according to the following procedures.

  A test piece (foamed wallpaper) was attached to a Gakushin abrasion tester (JIS L0849 abrasion tester type II). Using a metal claw designated by the group as a friction machine of the testing machine, a load of 200 g was applied to the tip of the metal claw and the sample was reciprocated five times. The surface condition of the test piece after the test was visually observed.

  Evaluation of scratch resistance in the above-mentioned regulations is as follows: Grade 5: No change, Grade 4: A little change on the surface, Grade 3: The surface appears torn, Grade 2: The surface is torn and a backing material such as paper is visible (long) Less than 1 cm) First grade: There are five stages in which the surface is torn and the backing material such as paper can be seen (length is 1 cm or more).

Test Example 2 (Whiteness)
The degree of yellowing of the foamed wallpaper prepared in Examples and Comparative Examples was confirmed by measuring the whiteness using a color difference meter of CIE 1976 Lab color system (JIS Z 8729).
A small yellowness (b value less than 5) was evaluated as ◯, and a large yellowness (b value of 5 or more) was evaluated as x.

FIG. 1 is a diagram showing an outline of an example of the production method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... First non-foamed resin layer raw material tank 2 ... Second non-foamed resin layer raw material tank 3 ... Foaming agent-containing resin layer raw material tank 4 ... Recycled raw material tank 5 ... First non-foamed resin layer extruder 6 ... Second non-foaming resin layer extruder 7 ... Foaming agent-containing resin layer extruder 8 ... Multi-manifold T-die 9 ... Trimming part 10 ... Recycle granulator 11 ... Paper-based base material laminating part 12 ... Electron beam irradiation part

Claims (2)

(1) A step of forming a three-layer laminate comprising a first non-foamed resin layer, a foaming agent-containing resin layer, and a second non-foamed resin layer by melt extrusion molding a resin composition for forming each layer. 1,
(2) Step 2 for trimming a part of the laminate formed in Step 1;
(3) Step 3 for supplying the trimming piece obtained in Step 2 to Step 1 as a resin composition for forming the foaming agent-containing resin layer,
A method for producing foam wallpaper comprising:
(A) The second non-foamed resin layer contains an ethylene-methacrylic acid copolymer resin having a methacrylic acid content of 10 to 15% by weight,
(B) the foaming agent-containing resin layer contains azodicarbonamide,
(C) In step 3, the trimming piece is supplied to step 1 so that the content of the ethylene-methacrylic acid copolymer resin in the foaming agent-containing resin layer is 1% by weight or less.
A method for producing foam wallpaper. The production method according to claim 1, wherein the foaming agent-containing resin layer further contains a zinc compound.

Images