JP4775075B2 - Method and system for producing foam wallpaper - Google Patents

Description

The present invention relates to a manufacturing method and a manufacturing system for 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.
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 and a manufacturing system for manufacturing high-quality foam wallpaper at low cost.

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

That is, this invention relates to the manufacturing method and manufacturing system of the following foam wallpaper.
1. A method for producing foam wallpaper,
(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 of regenerating the trimming piece obtained in Step 2 as a part of the resin composition for forming the foaming agent-containing resin layer in the next Step 1,
(4) Step 4 of laminating the laminate trimmed in part in Step 2 on the paper substrate so that the paper substrate and the first non-foamed resin layer are in contact with each other.
A method for producing foamed wallpaper.
2. The manufacturing method of said claim | item 1 including the process of irradiating an electron beam after the process 4.
3. The manufacturing method of said claim | item 1 or 2 including the process after the process 4 which makes the said foaming agent containing resin layer into a foamed resin layer by heating.
4 . Item 4. The method according to any one of Items 1 to 3, wherein in Step 2, the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. .
5. The resin component constituting the first non-foamed resin layer is an ethylene-vinyl acetate copolymer,
The resin component constituting the foaming agent-containing resin layer is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer and an ethylene-methacrylic acid copolymer,
The resin component constituting the second non-foamed resin layer is an ethylene-methacrylic acid copolymer,
The manufacturing method in any one of said claim | item 1-4.
6 . A foam wallpaper manufacturing system,
(1) Means for 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) means 2 for trimming a part of the laminate formed by means 1;
(3) Means 3 for regenerating the trimming piece obtained by means 2 as part of the resin composition for forming the foaming agent-containing resin layer in the following means 1,
(4) Means 4 for laminating the laminate trimmed partly by means 2 on the paper base material so that the paper base material and the first non-foamed resin layer are in contact with each other;
Foam wallpaper manufacturing system including.
7). Item 7. The manufacturing system according to Item 6, further comprising means for irradiating an electron beam after the means 4.
8). Item 8. The manufacturing system according to Item 6 or 7, further comprising means for heating the foaming agent-containing resin layer as a foamed resin layer after the means 4.
9 . Item 9. The manufacturing system according to any one of Items 6 to 8, wherein the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. .
10. The resin component constituting the first non-foamed resin layer is an ethylene-vinyl acetate copolymer,
The resin component constituting the foaming agent-containing resin layer is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer and an ethylene-methacrylic acid copolymer,
The resin component constituting the second non-foamed resin layer is an ethylene-methacrylic acid copolymer,
The manufacturing system according to any one of Items 6 to 9.

  According to the method and system for producing foamed wallpaper of the present invention, foamed wallpaper can be produced at low cost. And the foaming wallpaper obtained by the manufacturing method and manufacturing system of this invention has quality equivalent to the conventional foaming wallpaper.

Method for Producing Foamed Wallpaper The method for producing a foamed wallpaper according to the present invention comprises: (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. Step 1 for forming the resin composition for 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 The process 3 which reproduce | regenerates as a part of resin composition for forming the foaming agent containing resin layer in the following process 1 is included.

  In the manufacturing method of this invention, the said processes 1-3 are repeated in order. Specifically, first, as the first round, a foamed wallpaper is produced using the laminate obtained through the above steps 1 and 2. Then, the trimming piece obtained in the first round is regenerated in Step 1 after the second round to produce a foam wallpaper.

  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 reproduced | regenerated as a part of resin composition for forming a foaming agent containing resin layer.
Even when the trimming piece is regenerated as a part of the resin composition for forming the foaming agent-containing resin layer, a foamed wallpaper having the same quality as the foamed wallpaper obtained by a normal method can be obtained.

  When the trimming piece is regenerated as a part of the resin composition for forming the first non-foamed resin layer, it is caused by a residue (filler or the like) such as a resin composition that adheres to the die outlet during melt extrusion. The first non-foamed resin layer cannot be formed stably.

  Similarly, when the trimming piece is regenerated as a part of the resin composition for forming the second non-foamed resin layer, the second non-stable portion is stably caused by the residue (filler or the like) attached to the die outlet. A foamed resin layer cannot be formed. Moreover, the intended scratch resistance, wear resistance, etc. cannot be obtained.

  The foam wallpaper obtained by regenerating the trimming piece has the same quality as the foam wallpaper obtained by a normal method. Moreover, the raw materials used for forming the foaming agent-containing resin layer can be reduced by regenerating and using the trimming pieces. As a result, foamed wallpaper can be manufactured at low cost.

  In particular, in the production method of the present invention, it is preferable to regenerate the trimming pieces so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. By making the content of the trimming piece 30% by weight or less, the foamed wallpaper can be manufactured without inhibiting the foaming characteristics and the like of the manufactured foamed wallpaper. In particular, the content is desirably 20% by weight or less, and more desirably 15 to 20% by weight. In the production method of the present invention, from the viewpoint of producing foamed wallpaper at a low cost, the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 15% by weight or more. It is desirable.

  Hereinafter, the manufacturing method of the present invention will be described in detail with reference to FIG. FIG. 1 shows an outline of an example of the manufacturing method (or system) of the present invention.

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, at least 1 sort (s), such as ethylene-methacrylic acid copolymer (EMAA), EVA, EMMA, EEA, EMA, can be illustrated, for example. Among these, EMAA and EVA are particularly preferable.

  A foaming agent containing resin layer contains the said resin component, a foaming agent, another additive, etc.

  As the foaming agent, a pyrolytic foaming agent is preferable. Examples of the thermally decomposable foaming agent include azo series such as azodicarbonamide (ADCA) and azobisformamide; and hydrazide series such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. These can be used alone or in combination of two or more.

  The content of the pyrolytic foaming agent 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.

  Examples of other additives include inorganic fillers, pigments, cell regulators, and crosslinking aids. These can be used alone or in combination of two or more.

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

  Examples of the pigment include the following. Inorganic pigments include, 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), and cadmium. Examples thereof include red, ultramarine blue, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, and zinc sulfide. Examples of organic pigments include aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, Perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halogenated phthalocyanine) 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.

  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.

  Examples of the resin component for constituting the second non-foamed resin layer include EMAA, EVA, EMMA, EEA, EMA, linear low density polyethylene (LLDPE), and the like. Among these, EMAA is particularly preferable. The content of EMAA is preferably 70 to 100% by weight.

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, trimming may be performed using a score cutter, a shear cutter, or the like.

Process 3
In step 3, the trimming piece obtained in step 2 is regenerated as part of the resin composition for forming the foaming agent-containing resin layer in the next step 1. 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 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.

Production system for foamed wallpaper The production system for foamed wallpaper of the present invention comprises (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. Obtained by means 1 for forming a resin composition for forming each layer by melt extrusion, (2) means 2 for trimming a part of the laminate formed by means 1, and (3) means 2 A means 3 for regenerating the trimming piece as a part of the resin composition for forming the foaming agent-containing resin layer in the following means 1 is included.
An example of the system of the present invention is shown in FIG. Each means employed in the system of the present invention may be a known device. Each means and its role are as described in the manufacturing method. According to the manufacturing system of the present invention, the manufacturing method of the present invention can be suitably executed.

  In the example of the system (apparatus) of FIG. 1, as a raw material supply source, a first non-foamed resin layer raw material tank 1, a second non-foamed resin layer raw material tank 2, a foaming agent-containing resin layer raw material tank 3, and a recycled raw material A tank 4 is provided. These are connected to the first non-foamed resin layer extruder 5, the second non-foamed resin layer extruder 6, and the foaming agent-containing resin layer extruder 7 through pipes, respectively. Here, the pipe extending from the recycled raw material tank 4 is connected so as to join the pipe extending from the foaming agent-containing resin layer raw material tank 3. The first non-foamed resin layer extruder 5, the second non-foamed resin layer extruder 6, and the foaming agent-containing resin layer extruder 7 are connected so that raw materials can be supplied to the multi-manifold T-die 8. The laminated body obtained through the multi-manifold T die 8 is sent to the trimming unit 9, and a part of the laminated body is trimmed (cut out). The trimming pieces obtained here are fed into the regenerating granulator 10 and granulated as necessary, and then the obtained granulated material is supplied to the regenerating raw material tank 4 to produce a laminate. Reused.

  In particular, in the production system of the present invention, it is preferable to regenerate the trimming piece so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. By setting the trimming piece content to 30% by weight or less, a reproduction system can be constructed without hindering the foaming characteristics of the foamed wallpaper to be produced. In particular, the content is desirably 20% by weight or less, and more desirably 15 to 20% by weight. In the production system of the present invention, from the viewpoint of producing foamed wallpaper at a low cost, the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 15% by weight or more. It is desirable.

  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
(Foaming agent-containing resin layer)
In order to form a foaming agent-containing resin layer, the raw materials shown in Table 1 below were mixed, and pellets were prepared by melt extrusion using a twin screw extruder. In addition, mixing and melt extrusion were performed so that the resin temperature would not become 130 degreeC or more.

  The pellets and the following recycled pellets were mixed at a ratio of 80:20, supplied to the foaming agent-containing resin layer extruder 7 and melt-extruded. 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 “Ultrasen 750” MFR: 30 g / 10 min, VA content: 32% by weight, manufactured by Tosoh Corporation) is supplied to the extruder 5, Melt extruded. The melt extrusion was performed so that the resin temperature did not become 120 ° C. or higher. 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: 10% by weight, manufactured by Mitsui DuPont Polychemical) was added to the extruder 6. Feeded and melt extruded. The melt extrusion was performed so that the resin temperature did not become 140 ° C. or higher. As the extruder 6, a single screw extruder (Φ50 mm) was used.

(Production of foam wallpaper)
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 set to 120 ° 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.

Trimming pieces were sent to a crushing machine (not shown) through a suction pipe after trimming the ears (about 5 cm each) of the obtained laminate by a shear cutting method using a trimming unit 9 equipped with a cutting tool. 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).
The obtained recycled pellets were reused as a foaming agent-containing resin layer forming raw material as described above.
And the raw material for foamed wallpaper was obtained by laminating | stacking the laminated body after trimming in the paper-based base-material laminated part 11 on the paper-type base material (basis weight 70g) of 110 micrometers in thickness. The lamination was performed such that the paper-based substrate and the first non-foamed resin layer were in contact with each other.
Then, the electron beam irradiation part 12 irradiated the electron beam (200KV, 30KGy) from the said 1st non-foamed resin layer, and the resin component of each layer was bridge | crosslinked.
After the cross-linking, the obtained raw material for 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.
The foamed wallpaper was produced by the above method.

  Table 3 shows the expansion ratio and scratch resistance of the obtained foamed wallpaper.

Comparative Example 1
A foam wallpaper was produced in the same manner as in Example 1 except that the recycled pellets were not reused as the foaming agent-containing resin layer forming raw material.
Table 3 shows the expansion ratio and scratch resistance of the obtained foamed wallpaper.

The color difference (ΔE) between the raw material for foamed wallpaper obtained in Example 1 and the raw material for foamed wallpaper obtained in Comparative Example 1 was measured. The color difference (ΔE) was 0.2.
Further, the color difference (ΔE) between the foamed wallpaper obtained in Example 1 and the foamed wallpaper obtained in Comparative Example 1 was measured. The color difference (ΔE) was 0.2.

Example 2
In order to form the foaming agent-containing resin layer, a foamed wallpaper was prepared in the same manner as in Example 1 except that the raw materials shown in Table 2 below were mixed so that the resin temperature would not be 130 ° C. or higher.

得られた発泡壁紙の発泡倍率及び耐スクラッチ性を表３に示す。

Table 3 shows the expansion ratio and scratch resistance of the obtained foamed wallpaper.

Comparative Example 2
A foamed wallpaper was produced in the same manner as in Example 2 except that the recycled pellets were not reused as the foaming agent-containing resin layer forming raw material.
Table 3 shows the expansion ratio and scratch resistance of the obtained foamed wallpaper.
The color difference (ΔE) between the raw material for foamed wallpaper obtained in Example 2 and the raw material for foamed wallpaper obtained in Comparative Example 2 was measured. The color difference (ΔE) was 0.2.
Further, the color difference (ΔE) between the foamed wallpaper obtained in Example 2 and the foamed wallpaper obtained in Comparative Example 2 was measured. The color difference (ΔE) was 0.2.

Test example 1 (foaming ratio)
The foaming ratio of the foamed wallpaper created in the examples and comparative examples was confirmed with a thickness meter.

Test Example 2 (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 3 (color difference)
The color difference (ΔE) was confirmed using a color difference meter of CIE1976Lab color system (JIS Z 8279).

FIG. 1 is a diagram showing an outline of an example of the manufacturing method (or system) 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 (10)

A method for producing foam wallpaper,
(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 of regenerating the trimming piece obtained in Step 2 as a part of the resin composition for forming the foaming agent-containing resin layer in the next Step 1,
(4) Step 4 of laminating the laminate trimmed in part in Step 2 on the paper substrate so that the paper substrate and the first non-foamed resin layer are in contact with each other.
A method for producing foamed wallpaper.   The manufacturing method of Claim 1 including the process of irradiating an electron beam after the process 4.   The manufacturing method of Claim 1 or 2 including the process of making the said foaming agent containing resin layer into a foamed resin layer by heating after the process 4. The manufacturing method according to any one of claims 1 to 3, wherein in step 2, the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. .   The resin component constituting the first non-foamed resin layer is an ethylene-vinyl acetate copolymer,
  The resin component constituting the foaming agent-containing resin layer is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer and an ethylene-methacrylic acid copolymer,
  The resin component constituting the second non-foamed resin layer is an ethylene-methacrylic acid copolymer,
The manufacturing method in any one of Claims 1-4. A foam wallpaper manufacturing system,
(1) Means for 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) means 2 for trimming a part of the laminate formed by means 1;
(3) Means 3 for regenerating the trimming piece obtained by means 2 as part of the resin composition for forming the foaming agent-containing resin layer in the following means 1,
(4) Means 4 for laminating the laminate trimmed partly by means 2 on the paper base material so that the paper base material and the first non-foamed resin layer are in contact with each other;
Foam wallpaper manufacturing system including.   The manufacturing system according to claim 6, further comprising means for irradiating an electron beam after the means 4.   The manufacturing system according to claim 6 or 7, further comprising means for making the foaming agent-containing resin layer a foamed resin layer by heating after the means 4. The manufacturing system according to any one of claims 6 to 8, wherein in the means 2, the trimming piece is regenerated so that the content in the resin composition for forming the foaming agent-containing resin layer is 30% by weight or less. .   The resin component constituting the first non-foamed resin layer is an ethylene-vinyl acetate copolymer,
  The resin component constituting the foaming agent-containing resin layer is at least one selected from the group consisting of an ethylene-vinyl acetate copolymer and an ethylene-methacrylic acid copolymer,
  The resin component constituting the second non-foamed resin layer is an ethylene-methacrylic acid copolymer,
The manufacturing system according to claim 6.

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