Laminated sheet, sheet-like product, and method for producing same

Abstract

To provide a laminated sheet which is a polyurethane laminated sheet having an adhesive layer and a skin layer, and in which migration of low-molecular-weight substances from the adhesive layer to the skin layer is suppressed.SOLUTION: A laminated sheet is provided, comprising an intermediate layer made of hydroxypolyurethane, a skin layer disposed on one surface of the intermediate layer, and an adhesive layer disposed on the other surface of the intermediate layer, wherein the hydroxypolyurethane of the intermediate layer is a hydroxypolyurethane produced using carbon dioxide as a raw material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a laminated sheet, a sheet-like article, and a method for producing the same. [Background technology]

[0002] Polyurethane resin sheets have been used for the uppers of sports shoes, etc. However, low molecular weight monomers contained in polyurethane resins and additives added to polyurethane resins during sheet production can migrate to the surface of the polyurethane resin sheet, causing a bleeding phenomenon that mars the appearance and reduces strength.

[0003] In recent years, hydroxypolyurethane resins, which have both urethane bonds and hydroxyl groups in their chemical structure, have been developed as new polyurethane resins, and their industrial applications are expected. While existing polyurethane resins are produced using isocyanate compounds and polyols as raw materials, hydroxypolyurethane resins are produced using epoxy compounds, carbon dioxide, and amine compounds as raw materials. The raw material carbon dioxide is incorporated into the chemical structure of hydroxypolyurethane resins as -CO-O- bonds, so this resin has been attracting attention in recent years from the perspective of effective use of carbon dioxide, a greenhouse gas. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a polyurethane laminate sheet having an adhesive layer and a surface layer, in which migration of low molecular weight substances from the adhesive layer to the surface layer is suppressed. [Means for solving the problem]

[0005] The present invention is a laminated sheet comprising an intermediate layer made of hydroxy polyurethane, a skin layer disposed on one side of the intermediate layer, and an adhesive layer disposed on the other side of the intermediate layer, characterized in that the hydroxy polyurethane of the intermediate layer is hydroxy polyurethane produced using carbon dioxide as a raw material. The present invention also relates to a sheet-like article comprising the above-mentioned laminate sheet and a TPU type polyurethane substrate laminated on the adhesive layer. Effect of the Invention

[0006] According to the present invention, it is possible to provide a polyurethane laminate sheet having an adhesive layer and a surface layer, in which migration of low molecular weight substances from the adhesive layer to the surface layer is suppressed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The present invention will be described in detail below.

[0008] [Intermediate layer made of hydroxy polyurethane] The intermediate layer is made of hydroxy polyurethane, which is produced using carbon dioxide as a raw material.

[0009] This hydroxy polyurethane is obtained by a polyaddition reaction between a compound having at least two five-membered cyclic carbonate structures and a compound having at least two amino groups. The five-membered cyclic carbonate structure is a five-membered cyclic carbonate structure synthesized at least in part using carbon dioxide as a raw material. In this hydroxy polyurethane, 1 to 20% of the -O-CO- bonds are carbon dioxide-derived -O-CO- bonds.

[0010] Hydroxy polyurethane has high crystallinity and is easily separated from other resins, so that in this intermediate layer, hydroxy polyurethane preferably accounts for 100% by weight based on the weight of the intermediate layer. From the viewpoint of maintaining flexibility, the thickness of this intermediate layer is preferably 5 to 10 μm. Hydroxy polyurethane repels other polyurethanes, so it is preferable that it does not contain polyurethane pigments.

[0011] [Epidermal layer] The surface layer is a polyurethane layer, and the thickness thereof is preferably 5 to 100 μm from the viewpoint of obtaining basic physical properties such as appearance and flexibility, peel strength, etc. This layer is preferably a solid layer. The surface layer has a role of protecting the surface and prevents the appearance from being damaged by abrasion when the laminate sheet of the present invention is used as a substitute for leather in shoes, bags, and the like.

[0012] [Adhesive layer] The adhesive layer is a layer of a polymeric elastomer. Examples of the polymeric elastomer include polyurethane elastomer, polyurea elastomer, polyurethane-polyurea elastomer, polyacrylic acid resin, acrylonitrile-butadiene elastomer, and styrene-butadiene elastomer. From the viewpoint of obtaining good physical properties, a polyurethane elastomer is preferably used. It is preferable that a crosslinking agent containing a highly reactive substituent such as an isocyanate group at the end is added to this polymeric elastomer.

[0013] The thickness of the adhesive layer is preferably 5 to 50 μm, more preferably 5 to 35 μm. If the thickness of the adhesive layer is less than 5 μm, it is not preferable because a slight distortion in the coating device may cause adhesion failure. On the other hand, if the thickness exceeds 50 μm, the adhesive layer becomes too thick, and the adhesive layer affects the hardness of the material. If the rigidity of the material becomes high, it becomes difficult to wind the material when processing it into a roll, and the material tends to have a tendency to become curled and warp after pad processing, which is not preferable.

[0014] In the present invention, the intermediate layer between the adhesive layer and the skin layer is made of hydroxy polyurethane produced using carbon dioxide as a raw material, thereby making it possible to suppress the migration of low molecular weight substances from the adhesive layer to the skin layer.

[0015] [TPU-type polyurethane base material] The TPU-type polyurethane substrate used in the present invention is a TPU-type polyurethane substrate made of a polyurethane resin having thermoplastic properties. As other polyurethane substrates, polyurethane substrates prepared by wet molding in which a solvent-based polyurethane resin dispersed in an organic solvent is impregnated into a nonwoven fabric and then replaced with water to solidify the polyurethane, and polyurethane substrates using water-based polyurethane can also be used.

[0016] [Application] The sheet-like material of the present invention can be suitably used as an upper for shoes, that is, the present invention provides a shoe including the above-mentioned sheet-like material as an upper.

[0017] [Manufacturing method] The sheet-like material of the present invention can be produced by a method for producing a sheet-like material, which includes the steps of providing a surface layer on release paper, applying a hydroxy polyurethane using carbon dioxide as a raw material onto the surface layer to form an intermediate layer, and bonding a TPU type polyurethane base material onto the intermediate layer via an adhesive layer.

[0018] The hydroxy polyurethane is applied as a solution or dispersion, with an organic solvent or water being used as the solvent or dispersion medium. If the amount of the hydroxy polyurethane solution or dispersion applied is large, the thickness of the hydroxy polyurethane layer increases and the flexibility is significantly reduced. Therefore, the amount of the hydroxy polyurethane solution or dispersion applied is preferably 10 to 30 g / m. 2 by weight of a solution or dispersion containing a hydroxy polyurethane.

[0019] Hydroxy polyurethane easily repels low-viscosity liquids, so the viscosity of the liquid applied to provide an adhesive layer on the hydroxy polyurethane layer is preferably 2000 mPa·s or more. EXAMPLES

[0020] The present invention will now be described in detail with reference to examples. "Parts" means parts by weight.

[0021] Example 1 A solution (viscosity: 1220 mPa s) of 100 parts of solvent-based polyurethane (DIC "Crisbon S-125", polyurethane concentration 30%, melting point 145°C), 70 parts of dimethylformamide (DMF), 30 parts of methyl ethyl ketone (MEK), and 1 part of dye was applied at 90 g / m on a release paper. 2 The coating was then dried in a dryer at 70°C for 10 minutes to form a surface layer (polyurethane layer).

[0022] A solution of 30 parts of hydroxy polyurethane (manufactured by Dainichiseika Chemicals Mfg. Co., Ltd., solid, thermal softening point 97°C, in which 16% of the -O-CO- bonds of this hydroxy polyurethane are carbon dioxide-derived -O-CO- bonds) with 40 parts of DMF and 30 parts of MEK was applied to the surface of the skin layer at 50 g / m. 2 The mixture was then dried in a dryer at 70°C for 10 minutes to form an intermediate layer (hydroxy polyurethane layer).

[0023] Furthermore, on the intermediate layer, a solution (viscosity: 2440 mPa s) containing 100 parts of polyurethane adhesive (DIC "Crisbon OA-370", polyurethane concentration 40% by weight, melting point 140°C), 30 parts of DMF, 10 parts of MEK, and a polyisocyanate crosslinking agent (Dainichiseika Chemicals Mfg. Co., Ltd. "Rezamin NE crosslinking agent", polyisocyanate concentration 75% by weight) was applied at 140 g / m 2 The adhesive layer was formed by applying the adhesive at a weight of 110°C and drying for 30 seconds at 110°C.

[0024] Thereafter, a 0.15 mm thick TPU type polyurethane substrate (manufactured by Kimyung) was superimposed on the adhesive layer, and passed through rolls with a gap of 0.3 mm for pressure bonding. After that, it was left in a thermostatic chamber at 70°C for 1 day, and then the release paper was peeled off to obtain a sheet-like material (polyurethane sheet-1). When the adhesive layer of the obtained sheet-like material was visually observed, no bleeding phenomenon was observed. In addition, the peel strength of this sheet-like material was 4.76 kg / cm.

[0025] Example 2 A solution of 100 parts of water-dispersed polyurethane (DIC "Hydran TMS-236", polyurethane concentration 35% by weight), 1 part of Carbodilite, and 5 parts of dye was applied at 90 g / m on a release paper. 2 The coating was applied at a weight of 100 g / m2. The coating was then dried in a dryer at 70° C. for 10 minutes to form a surface layer (polyurethane layer).

[0026] A solution of 30 parts of hydroxy polyurethane (manufactured by Dainichiseika Chemicals Mfg. Co., Ltd., solid, thermal softening point 97°C, in which 16% of the -O-CO- bonds of this hydroxy polyurethane are carbon dioxide-derived -O-CO- bonds) with 40 parts of DMF and 30 parts of MEK was applied to the surface of the skin layer at 50 g / m. 2 The mixture was then dried in a dryer at 70°C for 10 minutes to form an intermediate layer (hydroxy polyurethane layer).

[0027] Further, on the intermediate layer, 100 parts of a water-dispersible polyurethane adhesive (DIC Corporation's "Hydran TMA-478", polyurethane concentration 45% by weight) and a polyisocyanate crosslinking agent ("DNW-5500") were mixed at 140 g / m 2 The adhesive layer was formed by applying the adhesive at a weight of 100g and drying at 110°C for 5 minutes.

[0028] Then, a 0.15 mm thick TPU type polyurethane substrate (Kimyung) was superimposed on the adhesive layer and passed through a roll with a gap of 0.3 mm to be pressed. Then, the adhesive layer was left in a thermostatic chamber at 70° C. for 1 day, and the release paper was peeled off to obtain a sheet-like material (polyurethane sheet-2). When the adhesive layer of the obtained sheet-like material was visually observed, no bleeding phenomenon was observed.

[0029] Example 3 A solution (viscosity: 1220 mPa s) of 100 parts of solvent-based polyurethane (DIC "Crisbon S-125", polyurethane concentration 30% by weight, melting point 145°C), 70 parts of dimethylformamide (DMF), and 30 parts of methyl ethyl ketone (MEK) was applied at 90 g / m 2 The coating was applied at a weight of 100 g / m2. The coating was then dried in a dryer at 70° C. for 10 minutes to form a surface layer (polyurethane layer).

[0030] A solution of 30 parts of hydroxy polyurethane (manufactured by Dainichiseika Chemicals Mfg. Co., Ltd., solid, thermal softening point 97°C, in which 16% of the -O-CO- bonds of this hydroxy polyurethane are carbon dioxide-derived -O-CO- bonds) with 40 parts of DMF and 30 parts of MEK was applied to the surface of the skin layer at 50 g / m. 2 The mixture was then dried in a dryer at 70°C for 10 minutes to form an intermediate layer (hydroxy polyurethane layer).

[0031] Further, on the intermediate layer, 140 g / m of a solution containing 100 parts of a polyurethane adhesive (DIC Corporation's "Crisbon OA-370", polyurethane concentration 40% by weight, melting point 140°C), 30 parts of DMF, 10 parts of MEK, and a polyisocyanate crosslinking agent (Dainichiseika Chemicals Mfg. Co., Ltd.'s "Rezamin NE crosslinking agent", polyisocyanate concentration 75% by weight) was applied. 2 The adhesive layer was formed by applying the adhesive at a weight of 100g and drying at 110°C for 30 seconds.

[0032] Then, a 1.20 mm thick polyurethane resin-impregnated substrate was placed on the adhesive layer and passed through rolls with a gap of 0.8 mm to bond them together. Note that this polyurethane resin-impregnated substrate is prone to bleeding because it contains a hydrophobic low molecular weight substance as a component.

[0033] After that, it was left in a thermostatic bath at 70°C for 1 day, and then the release paper was peeled off to obtain a sheet-like material (polyurethane resin-impregnated substrate coated material-1). The obtained coated material was heated in a thermostatic bath at 70°C for 3 weeks, but the low molecular weight substances contained in the impregnated substrate did not precipitate on the coated surface, and no bleeding phenomenon was observed.

[0034] Comparative Example 1 A skin layer was prepared in the same manner as in Example 1. Thereafter, a solution obtained by mixing 50 parts of polyurethane (DIC Corporation's "Crisbon NB-140", polyurethane concentration 30% by weight), 50 parts of polyurethane (Seiko Chemicals Corporation's "Luckskin SY-2266", polyurethane concentration 40% by weight), 70 parts of DMF, and 30 parts of MEK was applied to the surface of the skin layer at a concentration of 50 g / m 2 The mixture was then dried in a dryer at 70° C. for 10 minutes to form an intermediate layer (second polyurethane layer).

[0035] On the intermediate layer, 140 g / m of a mixture of 100 parts of polyurethane adhesive (DIC Corporation's "Crisbon OA-370", polyurethane concentration 40% by weight, melting point 140°C), 30 parts of DMF, 10 parts of MEK, and a polyisocyanate crosslinking agent (Dainichiseika Chemicals Mfg. Co., Ltd.'s "Rezamin NE crosslinking agent" with a polyisocyanate concentration of 75% by weight) was applied. 2 The adhesive layer was formed by applying the adhesive at a weight of 100g and drying at 110°C for 30 seconds.

[0036] Then, a 0.15 mm thick TPU type polyurethane substrate (Kimyung) was superimposed on the adhesive layer and passed through a roll with a gap of 0.3 mm for pressure bonding. After that, it was left in a thermostatic chamber at 70° C. for 1 day, and the release paper was peeled off to obtain a sheet-like material (polyurethane sheet-3). The obtained sheet-like material was compared with the sheet-like material obtained in Example 1 (Polyurethane Sheet-1), in which white stains appeared on the surface of the transfer layer, and the bleeding phenomenon was strongly observed.

[0037] Comparative Example 2 A solution of 30 parts of hydroxy polyurethane (manufactured by Dainichiseika Chemicals Mfg. Co., Ltd., solid, thermal softening point 97°C, in which 16% of the -O-CO- bonds of this hydroxy polyurethane are carbon dioxide-derived -O-CO- bonds) mixed with 40 parts of DMF and 30 parts of MEK was applied at 50 g / m on a release paper. 2 The coating was applied at a weight of 100 g / m2, and then dried in a dryer at 70° C. for 10 minutes to form a surface layer (hydroxy polyurethane layer).

[0038] A solution of 50 parts of polyurethane (DIC Corporation's "Crisbon NB-140", polyurethane concentration 30% by weight), 50 parts of polyurethane (Seiko Chemicals Corporation's "Luckskin SY-2266", polyurethane concentration 40% by weight), 70 parts of DMF, and 30 parts of MEK was applied to the surface of the skin layer at 90 g / m 2 The mixture was then dried in a dryer at 70° C. for 10 minutes to form an intermediate layer (second polyurethane layer).

[0039] Further, on the intermediate layer, 140 g / m of a solution containing 100 parts of a polyurethane adhesive (DIC Corporation's "Crisbon OA-370", polyurethane concentration 40% by weight, melting point 140°C), 30 parts of DMF, 10 parts of MEK, and a polyisocyanate crosslinking agent (Dainichiseika Chemicals Co., Ltd.'s "Rezamin NE crosslinking agent", polyisocyanate concentration 75% by weight) was applied. 2 The adhesive layer was formed by applying the adhesive at a weight of 100g and drying at 110°C for 30 seconds.

[0040] Then, a 0.15 mm thick TPU type polyurethane substrate (Kimyung) was superimposed on the adhesive layer and passed through a roll with a gap of 0.3 mm to be pressed. After that, it was left in a thermostatic chamber at 70° C. for 1 day, and the release paper was peeled off to obtain a sheet-like material (polyurethane sheet-4).

[0041] The peel strength of the obtained sheet-like product (polyurethane sheet-4) was 2.45 kg / cm. This sheet-like product (polyurethane sheet-4) had a lower peel strength than the sheet-like product (polyurethane sheet-1) obtained in Example 1, and was inferior in durability as a sheet-like product.

[0042] Comparative Example 3 A skin layer was prepared in the same manner as in Example 3. Thereafter, a solution obtained by mixing 50 parts of polyurethane (DIC Corporation's "Crisbon NB-140", polyurethane concentration 30% by weight), 50 parts of polyurethane (Seiko Chemicals Corporation's "Luckskin SY-2266", polyurethane concentration 40% by weight), 70 parts of DMF, and 30 parts of MEK was applied to the surface of the skin layer at a rate of 90 g / m 2 The mixture was then dried in a dryer at 70° C. for 10 minutes to form an intermediate layer (second polyurethane layer).

[0043] On the intermediate layer, 140 g / m of a mixture of 100 parts of polyurethane adhesive (DIC Corporation's "Crisbon OA-370", polyurethane concentration 40% by weight, melting point 140°C), 30 parts of DMF, 10 parts of MEK, and a polyisocyanate crosslinking agent (Dainichi Seikagaku Chemicals' "Rezamin NE crosslinking agent" with a polyisocyanate concentration of 75% by weight) was applied. 2 The adhesive layer was formed by applying the adhesive at a weight of 1.20 mm and drying at 110°C for 30 seconds. A polyurethane resin-impregnated substrate with a thickness of 1.20 mm was then placed on the adhesive layer and passed through a roll with a gap of 0.8 mm to bond the adhesive layer. Note that this polyurethane resin-impregnated substrate is prone to bleeding because it contains a hydrophobic low molecular weight substance as a component.

[0044] After that, it was left in a thermostatic chamber at 70°C for 1 day, and then the release paper was peeled off to obtain a sheet-like material (polyurethane resin-impregnated substrate coated material-2). When the obtained sheet-like material was heated in a thermostatic chamber at 70°C for 3 weeks, low molecular weight substances contained in the impregnated substrate were precipitated on the transfer layer surface of the sheet-like material, and a bleeding phenomenon was observed. [Industrial Applicability]

[0045] The sheet-like material and laminated sheet of the present invention can be suitably used as a component of leather products, particularly as the upper part of shoes.

Claims

1. A laminated sheet comprising an intermediate layer made of hydroxy polyurethane, a skin layer disposed on one side of the intermediate layer, and an adhesive layer disposed on the other side of the intermediate layer, wherein the hydroxy polyurethane of the intermediate layer is produced using carbon dioxide as a raw material.

2. 2. A sheet-like article comprising the laminate sheet according to claim 1 and a TPU type polyurethane substrate laminated on the adhesive layer of the laminate sheet.

3. A shoe comprising the sheet material according to claim 2 as an upper.

4. A method for producing a sheet-like product, comprising the steps of: providing a surface layer on release paper; applying a hydroxy polyurethane using carbon dioxide as a raw material onto the surface layer to form an intermediate layer; and bonding a TPU type polyurethane base material onto the intermediate layer via an adhesive layer.