JP2014205357A - Laminate before foaming foamed laminated sheet, production method of laminate before forming foamed laminated sheet, and production method of foamed laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate before foaming a foamed laminated sheet, which easily provides a desired expansion ratio and a foamed laminated sheet with suppressed discoloration over time of a foamed resin layer after foaming, the foamed laminated sheet being obtained by forming a resin layer containing a blowing agent by producing a film of a resin composition containing a resin component and a heat-decomposable blowing agent and, further, forming a foamed resin layer by foaming the resin layer containing a blowing agent, and to provide a production method of the laminate before foaming a foamed laminated sheet and a production method of the foamed laminated sheet.SOLUTION: A laminate before foaming a foamed laminated sheet comprises at least a resin layer containing a blowing agent on a substrate where (1) the resin layer containing a blowing agent is formed by forming a film of a resin composition containing polyethylene, an ethylene-α-olefin copolymer, an azo-based heat-decomposable blowing agent, and a zinc-based foaming adjuvant, and where (2) the zinc-based foaming adjuvant includes zinc stearate and zinc octanoate.

Description

  The present invention relates to a foamed laminated sheet in which discoloration with time of a foamed resin layer is suppressed.

  Conventionally, a foamed laminated sheet (foamed decorative sheet) is known in which a foamed resin layer of vinyl chloride resin is formed on a base material (for example, backing paper). In recent years, in consideration of the environment, resins containing no halogen such as ethylene-vinyl acetate copolymer resin (EVA), acrylic resin, polyethylene resin, ethylene-α olefin copolymer have been used for the foamed resin layer. (Patent Documents 1 to 3 etc.). In particular, a mixed resin of polyethylene and ethylene-α-olefin copolymer has excellent curling properties and excellent foam strength.

  In addition, the foamed resin layer is formed by foaming a foaming agent-containing resin layer containing a pyrolytic foaming agent by heating. As the pyrolytic foaming agent, the amount of generated gas is large and the foaming temperature is easily controlled. For this reason, an azo-based pyrolytic foaming agent is used.

  However, the azo-based thermally decomposable foaming agent has a problem that the residue remains in the foamed resin layer even after the foaming agent-containing resin layer is heated and foamed, and as a result, the yellow color of the foaming agent itself remains in the foamed resin layer. Further, there is a problem that these colors change to white by irradiation with ultraviolet rays or the like in the process of using the foamed laminated sheet.

  Therefore, development of a foamed laminated sheet in which discoloration with time of the foamed resin layer is suppressed is desired.

Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A

  The present invention forms a foaming agent-containing resin layer by forming a resin composition containing a resin component and a pyrolytic foaming agent, and further foams the foaming agent-containing resin layer to form a foaming resin layer. It is a main object of the present invention to provide a foamed laminated sheet obtained by the above process, in which discoloration with time of the foamed resin layer is suppressed.

  As a result of intensive studies, the present inventor has found that the above object can be achieved when a specific foaming aid is used, and has completed the present invention.

That is, this invention relates to the manufacturing method of the laminated body before foaming of the following foamed laminated sheet, the laminated body before foaming of a foamed laminated sheet, and the manufacturing method of a foamed laminated sheet.
1. A laminate prior to foaming of a foam laminate sheet having at least a foaming agent-containing resin layer on a substrate,
(1) The foaming agent-containing resin layer is formed by forming a resin composition containing polyethylene and an ethylene-α-olefin copolymer, an azo pyrolysis foaming agent, and a zinc foaming aid,
(2) The zinc-based foaming aid is zinc stearate and zinc octylate.
The laminated body before foaming of the foaming laminated sheet characterized by the above-mentioned.
2. Item 2. The laminate before foaming of the foamed laminate sheet according to Item 1, wherein the content ratio of the zinc stearate and the zinc octylate is 90:10 to 10:90 in terms of the weight of metal zinc.
3. Item 3 or 2 above, wherein the zinc-based foaming aid is contained so that the total amount of zinc is 0.1 parts by weight or more with respect to 100 parts by weight of the resin component contained in the foaming agent-containing resin layer. Laminated body of foamed laminated sheet before foaming.
4). Item 4. The laminate before foaming of the foamed laminate sheet according to any one of Items 1 to 3, wherein the pyrolyzable foaming agent is azodicarbonamide.
5. Item 5. The laminated body before foaming of the foamed laminated sheet according to any one of Items 1 to 4, wherein a non-foamed resin layer A is further formed on the front surface of the foaming agent-containing resin layer.
6). The non-foamed resin layer A contains an ethylene- (meth) acrylic acid copolymer having a (meth) acrylic acid content of 15% by weight or less as a resin component before foaming of the foamed laminated sheet according to Item 5 above. Laminated body.
7). Item 7. The laminated body before foaming of the foamed laminated sheet according to any one of Items 1 to 6, wherein a non-foamed resin layer B is further formed between the base material and the foaming agent-containing resin layer.
8). The laminated body before foaming of the foaming laminated sheet in any one of said claim | item 1-7 in which the said base material consists of a fibrous sheet.
9. A method for producing a laminate before foaming of a foam laminate sheet having at least a foaming agent-containing resin layer on a substrate,
On the substrate
(1) A resin composition containing polyethylene and an ethylene-α-olefin copolymer, an azo-based pyrolytic foaming agent, and a zinc-based foaming aid,
(2) The zinc-based foaming aid is zinc stearate and zinc octylate, and includes a step of forming a foaming agent-containing resin layer by forming the resin composition.
The manufacturing method of the laminated body before foaming of the foaming laminated sheet characterized by the above-mentioned.
10. The ratio of the content of the zinc stearate and the zinc octylate is 90:10 to 10:90, respectively, in terms of the weight of metallic zinc, Production method.
11. Item 10 or 10 above, wherein the zinc-based foaming aid is contained so that the total amount of zinc is 0.1 parts by weight or more with respect to 100 parts by weight of the resin component contained in the foaming agent-containing resin layer. The manufacturing method of the laminated body before foaming of the foaming lamination sheet of this.
12 Item 12. The method for producing a laminate before foaming of the foamed laminated sheet according to any one of Items 9 to 11, wherein the pyrolyzable foaming agent is azodicarbonamide.
13. Item 13. The method for producing a laminate before foaming of the foamed laminated sheet according to any one of Items 9 to 12, wherein a non-foamed resin layer A is further formed on the front surface of the foaming agent-containing resin layer.
14 The non-foamed resin layer A contains an ethylene- (meth) acrylic acid copolymer having a (meth) acrylic acid content of 15% by weight or less as a resin component before foaming of the foamed laminated sheet according to Item 13 above. The manufacturing method of the laminated body.
15. Item 15. The method for producing a laminate before foaming of the foamed laminated sheet according to any one of Items 9 to 14, wherein a non-foamed resin layer B is further formed between the base material and the foaming agent-containing resin layer.
16. Item 16. The method for producing a laminate before foaming of the foamed laminated sheet according to any one of Items 9 to 15, wherein the base material is a fibrous sheet.
17. A method for producing a foam laminate sheet using the laminate before foaming of the foam laminate sheet obtained by the production method according to any one of Items 9 to 16,
Forming the foamed resin layer by foaming the foaming agent-containing resin layer;
The manufacturing method of a foaming lamination sheet containing this.
18. Furthermore, the manufacturing method of the foaming lamination sheet of said claim | item 17 which has the process of giving an embossing.

  Hereinafter, the foamed laminated sheet of the present invention will be described in detail.

The foam laminate sheet of the present invention is a foam laminate sheet having at least a foam resin layer on a substrate,
(1) The foamed resin layer is formed by foaming a foaming agent-containing resin layer,
(2) The foaming agent-containing resin layer is formed by forming a resin composition containing polyethylene and an ethylene-α-olefin copolymer, an azo-based pyrolytic foaming agent, and zinc stearate and zinc octylate. It is characterized by being.

  Since the foamed laminated sheet of the present invention having the above characteristics uses zinc stearate and zinc octylate as foaming aids, discoloration with time of the foamed resin layer is suppressed. Further, a desired expansion ratio can be obtained by a combination thereof.

  Hereinafter, each requirement will be described separately.

The base material is not particularly limited as long as it has mechanical strength, heat resistance, and the like suitable as a laminated sheet base material. For example, a resin sheet, a fibrous sheet (for example, paper, nonwoven fabric, etc., also simply referred to as fibrous). Etc. can generally be used.

  Of these, fiber sheets such as paper are preferable. Specifically, flame retardant paper (pulp-based sheets treated with flame retardants such as guanidine sulfamate and guanidine phosphate), aluminum hydroxide, magnesium hydroxide Examples include inorganic paper, fine paper, and thin paper containing inorganic additives such as

Although the basis weight of the substrate is not critical, 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 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 8 to 20 μm.

Foamed resin layer The foamed resin layer is formed by foaming a foaming agent-containing resin layer.

(Resin component)
As a resin component of the foaming agent-containing resin layer, polyethylene and an ethylene-α olefin copolymer are essential components. Although the mixing ratio of each component is not limited, for example, it is preferable to contain 1 to 150 parts by weight, more preferably 10 to 100 parts by weight of ethylene-α-olefin copolymer with respect to 100 parts by weight of polyethylene. preferable. The polyethylene and the ethylene-α-olefin copolymer preferably have an MFR of 10 to 40 g / 10 min. When the MFR of the polyethylene and ethylene-α olefin copolymer is within the above range, the resin composition containing the foaming agent has little temperature rise during extrusion film formation and can be formed in a non-foamed state. In the printing process, it is possible to perform a printing process on a smooth surface, and to obtain a printed matter with less design loss and excellent design. If the MFR is too large, the resin may be too soft and the resulting foam may have insufficient scratch resistance.

  The resin component of the foaming agent-containing resin layer may contain other resins in addition to the polyethylene and the ethylene-α-olefin copolymer. For example, polyolefin resin such as polypropylene, polystyrene, ethylene-vinyl acetate copolymer resin (EVA), ethylene- (meth) acrylic acid resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene system Thermoplastic resins such as copolymers, nylon, polyacetal resins, acrylic resins, polycarbonate resins, polyester resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyurethane resins, polyvinyl chloride resins, etc. Examples thereof include polymers and mixed resins thereof. When these resins are added, the content of polyethylene and ethylene-α-olefin copolymer (total amount of the two components) in the resin component of the foaming agent-containing resin layer is 60% by weight or more, preferably 70% by weight. It is preferable to set so as to be above.

  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 foamed state of the foamed resin layer (for example, the size of foamed cells, the density of foamed cells, etc.) is not limited, and can be appropriately designed according to the type and use of the foamed wallpaper.

  In the present invention, the foaming agent-containing resin layer is formed from a resin composition containing at least polyethylene and an ethylene-α-olefin copolymer, an azo-based pyrolytic foaming agent, and a foaming aid. In addition, inorganic fillers, pigments, stabilizers, lubricants, and the like can be used as appropriate.

(Foaming agent)
The foaming agent-containing resin layer of the present invention contains at least an azo-based thermally decomposable foaming agent as the foaming agent. Examples thereof include azo-based pyrolytic foaming agents such as azodicarbonamide (ADCA), azobisformamide, barium azodicarboxylate, and azobisisobutyronitrile. Of these, azodicarbonamide is preferred from the viewpoint of heat resistance stability during resin processing and the amount of gas generated during foaming. The azo-based thermally decomposable foaming agent can be used alone or in combination of two or more.

  The content of the azo-based thermally decomposable foaming agent can be appropriately set according to the type of foaming agent, the expansion ratio, and the like. From the viewpoint of the expansion ratio, it is 1.5 times or more, preferably about 3 to 7 times, and the pyrolytic foaming agent is preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the resin component. .

  In addition to the azo-based thermally decomposable foaming agent, other thermally decomposable foaming agent may be used in combination with the foaming agent of the present invention as necessary. Examples thereof include hydrazide-based pyrolytic foaming agents such as oxybenzenesulfonyl hydrazide (OBSH), paratoluenesulfonyl hydrazide, and benzenesulfonyl hydrazide. The other thermally decomposable foaming agents can be used alone or in combination of two or more. The content of the other pyrolyzable foaming agent is usually about 0.5 to 30% by weight in the total pyrolyzable foaming agent.

(Foaming aid)
In the present invention, zinc stearate and zinc octylate are contained as foaming aids. By containing zinc stearate and zinc octylate, it is possible to provide a foamed laminated sheet in which discoloration of the foamed resin layer is suppressed over time.

  The ratio of the content of zinc stearate and zinc octylate is preferably 90:10 to 10:90 when the parts by weight of these two zinc compounds are converted to parts by weight of zinc, respectively. 20-20: 80 is more preferable, and it is still more preferable that it is 64: 36-36: 64. When the ratio of the content of zinc stearate and zinc octylate is within the above-described range, a desired expansion ratio is more easily obtained, and the color change with time of the foamed resin layer is further suppressed. In the present invention, the foaming aid is substantially composed of two components of zinc stearate and zinc octylate, and the ratio of the content of zinc stearate and zinc octylate is 90:10 in terms of the weight of metallic zinc, respectively. 10:90 is preferable, 80: 20-20: 80 is more preferable, and 64: 36-36: 64 is more preferable.

  If other zinc-based foaming aids are contained in the foaming aid, the effects of the present invention are reduced, so it is better not to contain them as much as possible. For example, when zinc oxide is contained in the foaming aid, a desired foaming ratio cannot be obtained, and the foamed resin layer after foaming is not preferable because it changes color over time. Moreover, it is not preferable that zinc laurate is contained in the foaming aid because the color changes over time.

  The content of the zinc compound can be appropriately set according to the resin composition, but it is preferable to contain a foaming aid so that the total zinc amount is 0.1 parts by weight or more with respect to 100 parts by weight of the resin component, More preferably, it is 0.4 parts by weight or more. The upper limit is usually about 1 part by weight.

  Moreover, you may use together the foaming adjuvant which does not contain zinc other than the said zinc type foaming adjuvant as a foaming adjuvant. Examples thereof include metal oxides such as calcium oxide and aluminum oxide; and aliphatic salts such as calcium stearate, magnesium stearate, aluminum stearate, calcium montanate, magnesium montanate, and aluminum montanate.

  In addition to zinc stearate and zinc octylate as the foaming aid, when other foaming aid is used, the content of the other foaming aid is usually 0.1 to 20 in the total foaming aid. It is about wt%.

(Inorganic filler)
In this invention, you may contain an inorganic filler in the foaming agent containing resin layer as needed. Examples of the inorganic filler include calcium carbonate, 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.

(Pigment)
In this invention, you may contain a pigment in the foaming agent containing resin layer as needed. As for the pigment, for example, titanium oxide, carbon black, black iron oxide, yellow iron oxide, chrome lead, molybdate orange, cadmium yellow, nickel titanium yellow, chrome titanium yellow, iron oxide (valve), cadmium red, ultramarine blue, Inorganic pigments such as bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, mica titanium, zinc sulfide; for example, aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), polycyclic (Isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halo Organic pigments of emissions phthalocyanine), and 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.

  Although the thickness of a foaming agent containing resin layer is not limited, 40-150 micrometers is preferable in a non-foaming state (before foaming). 200-900 micrometers is preferable after foaming.

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

Non-foamed resin layer A
A non-foamed resin layer (non-foamed resin layer A) may be further formed on the front surface of the foamed resin layer.

The non-foamed resin layer A mainly protects the foamed resin layer. In the present invention, a layer formed of 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. Is preferably the non-foamed resin layer A.

  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 an ethylene- (meth) acrylic acid copolymer and an ionomer resin. As the ionomer resin, a resin having a structure in which the molecules of the ethylene- (meth) acrylic acid copolymer are intermolecularly bonded with metal ions such as sodium and zinc can be used. When such a resin component is used, it is possible to form a strong layer 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. A known additive can also be blended in the resin composition.

  The thickness of the non-foamed resin layer is not limited, but is preferably about 5 to 50 μm, more preferably about 8 to 20 μm.

  Although the melt flow rate value of the resin component depends on the type of the resin component to be used, etc., it is generally set as appropriate within a range of 10 g / 10 min or more. Usually, it is preferably 10 to 100 g / 10 minutes, particularly preferably 10 to 95 g / 10 minutes, and more preferably 20 to 80 g / 10 minutes. By using a material having such a numerical range, more excellent scratch resistance, wear resistance and the like can be obtained.

  Moreover, although content of the said resin component in a resin composition is not limited, Usually, it is preferable to set suitably in the range of 70 to 100 weight%.

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 laminated sheet. Examples of the design pattern include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern. A design pattern can be selected according to the kind of foam lamination sheet.

  The pattern pattern layer can be formed, for example, by printing a pattern pattern on the front surface of the non-foamed resin layer A. In addition, when forming a picture 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, for example, a pigment used in the above-described foaming agent-containing resin layer can be appropriately used.

  The binder resin is, for example, an acrylic resin, a styrene resin, a polyester resin, a urethane resin, a chlorinated polyolefin resin, a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, an alkyd resin, or a petroleum resin. Examples include resins, ketone resins, epoxy resins, melamine resins, fluorine resins, silicone resins, fiber derivatives, rubber resins, and the like.

  Examples of the solvent (or dispersion medium) include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and acetic acid-2 -Ester-based organic solvents such as ethoxyethyl; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Organic solvents; ether organic solvents such as diethyl ether, dioxane, tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, tetrachloroethylene Chlorinated organic solvents; and water.

  The thickness of the design pattern layer is different from the type of design pattern, but is generally preferably about 0.1 to 10 μm.

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 (scratch resistance, etc.), contamination resistance, pattern layer protection, etc. of foamed laminated sheets, those containing ionizing radiation curable resins as resin components are suitable It is. 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 this invention, you may attach | subject an embossing pattern suitably. In this case, what is necessary is just to emboss from the uppermost surface layer (on the opposite side to a base material) of a foaming lamination sheet. Embossing can be performed by known means such as pressing an embossed plate. For example, when the outermost surface layer is a surface protective layer, a desired embossed pattern can be formed by pressing the embossed plate after heat-softening the front surface. Examples of the embossed pattern include a wood grain plate conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin texture, a grain texture, a hairline, and a multiline groove.

<Method for producing foam laminated sheet>
The manufacturing method of a foam lamination sheet is not specifically limited. For example, in order to produce a foamed laminated sheet having a foamed resin layer and a non-foamed resin layer A on a substrate such as paper, simultaneous extrusion by 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 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. It tends to be a foreign material on the sheet surface. Therefore, when the inorganic filler is contained in the resin composition forming the foaming agent-containing resin layer, the non-foaming resin layer A and the non-foaming resin layer B can be coextruded together with the foaming agent-containing resin layer. preferable. 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. In this method, the coextruded laminate is simultaneously laminated (film formation) on the substrate. Since the resin layer laminated simultaneously with extrusion on the base material has adhesiveness by heat melting, it is bonded to the base material.

  Note that a laminate in which a plurality of layers are simultaneously formed in advance may be prepared, placed on the substrate, and bonded to the substrate by thermal lamination.

  After simultaneous lamination on the substrate, the foamed resin layer is formed by heating the foaming agent-containing resin layer. 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.

  Electron beam irradiation may be performed before the heat treatment. Thereby, since the resin (resin component) contained in the foaming agent-containing resin layer can be crosslinked, the surface strength, the degree of foaming, and the like of the foamed laminated sheet can be controlled. The energy of the electron beam is preferably about 150 to 250 kV. The irradiation amount is preferably about 1 to 7 Mrad. A known electron beam irradiation apparatus can be used as the electron beam source.

  Crosslinking of the resin contained in the foaming agent-containing resin layer can be carried out using a chemical crosslinking agent (also referred to as a crosslinking agent or a crosslinking aid). 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 with respect to 100 parts by weight of the resin component. In addition, it is also possible to promote the bridge | crosslinking by electron beam irradiation by using electron beam irradiation and the said crosslinking agent together.

  When a surface protective layer containing an ionizing radiation curable resin is formed, the surface protective layer can be cured by electron beam irradiation. Such electron beam irradiation can be performed simultaneously (same processing) as electron beam irradiation performed to crosslink the resin contained in the foaming agent-containing resin layer. That is, after forming a foaming agent-containing resin layer, a non-foaming resin layer, a pattern layer, and a surface protective layer containing an ionizing radiation curable resin in this order, the resin contained in the foaming agent-containing resin layer is irradiated with an electron beam. The resin contained in the surface protective layer can be cured while being crosslinked.

  When producing a foamed laminated sheet having a pattern layer, it is preferable to form a pattern layer on the surface of the non-foamed resin layer before the heat treatment. The pattern pattern layer may be formed as described above.

  The foamed laminated sheet can be used for applications such as foamed wallpaper, laminated skin material, cushioning flooring material, and heat-insulating cosmetic material.

  Since the foamed laminated sheet of the present invention uses a foaming aid containing zinc stearate and zinc octylate, a desired foaming ratio can be easily obtained, and color change with time of the foamed resin layer after foaming is suppressed. .

It is a schematic diagram which illustrates the layer structure of the foaming lamination sheet of this invention.

  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.

Examples 1-5 and Comparative Examples 1-4
Using a three-type, three-layer multi-manifold T-die extruder, the base material (backing paper) has a thickness of 10 μm / 60 μm / 10 μm in the order of non-foamed resin layer A / foaming agent-containing resin layer / non-foamed resin layer B. The film was formed by extrusion. Thereby, the laminated body which consists of non-foaming resin layer A / foaming agent containing resin layer / non-foaming resin layer B / base material was obtained.

  As a base material, backing paper “WK-665DO (manufactured by Kojin Co., Ltd.)” was prepared, heated to 90 ° C., and then the above three layers were extruded to form a film.

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

  The laminated body was irradiated with an electron beam (200 kV, 3 Mrad) from the non-foamed resin layer A side, and the foaming agent-containing resin layer was particularly resin-crosslinked. Further, a corona discharge treatment was performed on the non-foamed resin layer A. Further, a texture pattern was printed with water-based ink “Hydric” (manufactured by Dainichi Seika Kogyo Co., Ltd.).

  Next, the laminate on which the texture pattern was printed was heated in a gear oven (at 25O <0> C for 25 to 45 seconds) to foam the foaming agent-containing resin layer.

  Finally, the foam was embossed with a texture pattern to obtain a foam laminated sheet.

  Each layer was formed using the following components.

  The non-foamed resin layer A was formed by EMAA “Nucleel N1560 (MAA content: 15% by weight), manufactured by Mitsui DuPont Polychemical Co., Ltd.”.

  The foaming agent-containing resin layer is composed of 50 parts by weight of polyethylene resin “Petrocene 208, manufactured by Tosoh Corporation”, ethylene-α-olefin copolymer resin “LUMITAC54-1, manufactured by Tosoh Corporation”, titanium oxide “Typaque CR-63, "Ishihara Sangyo Co., Ltd." 30 parts by weight, ADCA foaming agent "Uniform Ultra AZ3050I Otsuka Chemical Co., Ltd." 6 parts by weight, each zinc compound as a foaming aid. About the content component and content of each zinc compound, it showed in following Table 1. (The numerical value of Table 1 shows the weight part of a zinc compound. However, the lowest stage of Table 1 is contained in a foaming agent containing resin layer. Parts by weight of the total zinc content).

  The non-foamed resin layer B was formed by EVA “Evaflex EV150 (VA content: 33 wt%), manufactured by Mitsui DuPont Polychemical Co., Ltd.”.

Test example 1
Regarding the foamed laminated sheets prepared in Examples and Comparative Examples, 1) weather discoloration of the foamed laminated sheets 2) foaming characteristics were evaluated. The results are shown in Table 2 below.

  1) Weather resistance discoloration was evaluated according to the following criteria. First, an acceleration test (40 hours) was performed using a fade meter “ultraviolet fade meter U48AU, manufactured by Suga Test Instruments Co., Ltd.”. Next, the color difference on the surface of the foamed laminated sheet was measured with a colorimetric device “color difference meter CR-300, manufactured by Konica Minolta”. When the degree of color change (ΔE) was ΔE ≦ 1.9, the evaluation was ○, and when ΔE> 1.9, the evaluation was ×.

  2) With respect to foaming characteristics, the foaming ratio of the foamed resin layer is more than 8 times, the foaming ratio is 6 to 8 times, and the foaming ratio is less than 6 times by passing through the foaming process (35 seconds at 220 ° C.). Was evaluated as x.

  As is clear from Table 2 above, the combined use of zinc stearate and zinc octylate in the foaming aid produces a synergistic effect in the foaming aid described above. That is, it is possible to obtain a foamed laminated sheet in which a desired foaming ratio can be easily obtained and discoloration with time of the foamed resin layer is suppressed.

1. Backing paper2. Non-foamed resin layer B
3. 3. Foamed resin layer Non-foamed resin layer A
5. Pattern layer

Claims (18)

A laminate prior to foaming of a foam laminate sheet having at least a foaming agent-containing resin layer on a substrate,
(1) The foaming agent-containing resin layer is formed by forming a resin composition containing polyethylene and an ethylene-α-olefin copolymer, an azo pyrolysis foaming agent, and a zinc foaming aid,
(2) The zinc-based foaming aid is zinc stearate and zinc octylate.
The laminated body before foaming of the foaming laminated sheet characterized by the above-mentioned.   The laminated body before foaming of the foaming laminated sheet of Claim 1 whose ratio of content of the said zinc stearate and the said zinc octylate is 90: 10-10: 90 in conversion of the weight of metallic zinc, respectively.   The zinc-based foaming auxiliary agent is contained according to claim 1 or 2, wherein the total amount of zinc is 0.1 parts by weight or more with respect to 100 parts by weight of the resin component contained in the foaming agent-containing resin layer. Laminated body of foamed laminated sheet before foaming.   The laminated body before foaming of the foaming laminated sheet in any one of Claims 1-3 whose said thermal decomposition type foaming agent is azodicarbonamide.   The laminated body before foaming of the foaming laminated sheet in any one of Claims 1-4 in which the non-foaming resin layer A is further formed in the front surface of the said foaming agent containing resin layer.   The non-foamed resin layer A contains an ethylene- (meth) acrylic acid copolymer having a (meth) acrylic acid content of 15% by weight or less as a resin component before foaming of the foamed laminated sheet according to claim 5. Laminated body.   The laminated body before foaming of the foaming laminated sheet in any one of Claims 1-6 in which the non-foaming resin layer B is further formed between the said base material and the said foaming agent containing resin layer.   The laminated body before foaming of the foamed laminated sheet according to any one of claims 1 to 7, wherein the substrate comprises a fibrous sheet. A method for producing a laminate before foaming of a foam laminate sheet having at least a foaming agent-containing resin layer on a substrate,
On the substrate
(1) A resin composition containing polyethylene and an ethylene-α-olefin copolymer, an azo-based pyrolytic foaming agent, and a zinc-based foaming aid,
(2) The zinc-based foaming aid is zinc stearate and zinc octylate, and includes a step of forming a foaming agent-containing resin layer by forming the resin composition.
The manufacturing method of the laminated body before foaming of the foaming laminated sheet characterized by the above-mentioned.   The ratio of the content of the zinc stearate and the zinc octylate is 90:10 to 10:90, respectively, in terms of the weight of metallic zinc. Production method.   11. The zinc-based foaming aid is contained according to claim 9 or 10, wherein the zinc-based foaming aid is contained so that the total amount of zinc is 0.1 parts by weight or more with respect to 100 parts by weight of the resin component contained in the foaming agent-containing resin layer. The manufacturing method of the laminated body before foaming of the foaming lamination sheet of this.   The manufacturing method of the laminated body before foaming of the foaming laminated sheet in any one of Claims 9-11 whose said thermal decomposition type foaming agent is azodicarbonamide.   The manufacturing method of the laminated body before foaming of the foaming laminated sheet in any one of Claims 9-12 in which the non-foaming resin layer A is further formed in the front surface of the said foaming agent containing resin layer.   The non-foamed resin layer A contains an ethylene- (meth) acrylic acid copolymer having a (meth) acrylic acid content of 15% by weight or less as a resin component before foaming of the foamed laminated sheet according to claim 13. The manufacturing method of the laminated body.   The manufacturing method of the laminated body before foaming of the foaming laminated sheet in any one of Claims 9-14 in which the non-foaming resin layer B is further formed between the said base material and the said foaming agent containing resin layer.   The manufacturing method of the laminated body before foaming of the foaming laminated sheet in any one of Claims 9-15 in which the said base material consists of a fibrous sheet. A method for producing a foam laminate sheet using the laminate before foaming of the foam laminate sheet obtained by the production method according to claim 9,
Forming the foamed resin layer by foaming the foaming agent-containing resin layer;
The manufacturing method of a foaming lamination sheet containing this.   Furthermore, the manufacturing method of the foaming lamination sheet of Claim 17 which has the process of giving an embossing.

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