Molding packaging material and battery case
Provided is a molding packaging material that can have an increased use life, can suppress a decrease over time in inter-layer lamination strength, and has superior molding properties in extrusion molding, draw forming, and the like. The laminate molding packaging material contains: an outside substrate layer ( 2 ) comprising a heat-resistant resin; an inside sealant layer ( 3 ) comprising a thermoplastic resin; and a metal foil provided between the two layers as a barrier layer ( 4 ). In the heat-resistant resin of the outside substrate layer ( 2 ), a biaxially oriented polyethyleneterephthalate film is used that, when the tensile breaking strength in the M direction is MB and the tensile breaking strength in the T direction is TB, the following are satisfied: formula (I) 500 MPa=MB+TB=700 MPa; and formula (II) ¦MB−TB¦=30 MPa.
1. A molding packaging material, comprising:
an outside substrate layer containing a heat-resistant resin;
an inside sealant layer containing a thermoplastic resin; and
a metallic foil as a barrier layer provided between the outside substrate layer and the inside sealant layer; wherein
at least an inside surface of the metallic foil layer is subjected to chemical conversion treatment, an inside adhesion resin layer is laminated on the chemical conversion-treated surface, and the inside sealant layer is further laminated through the adhesion resin layer,
the outside substrate layer contains a biaxially oriented polyethylene terephthalate film, and the biaxially oriented polyethylene terephthalate film satisfies the following Expressions (I) and (II),
500 MPa≦ MB+TB≦ 700 MPa Expression (I)
| MB−TB|≦ 30 MPa Expression (II)
the MB is a tensile breaking strength in a direction M of the biaxially oriented polyethylene terephthalate film and the TB is a tensile breaking strength in a direction T of the biaxially oriented polyethylene terephthalate film;
the inside adhesion resin layer contains an adhesive containing a multifunctional isocyanate compound and a polyolefin resin having a carboxyl group, which is a modified polyolefin resin of graft polymerized ethylenic unsaturated carboxylic acid or an acid anhydride thereof with polyolefin, or a copolymerization resin of an olefin monomer and ethylenic unsaturated carboxylic acid, such that the inside adhesion resin layer has adhesiveness to both the metallic foil and the thermoplastic resin of the inside sealant layer;
the inside sealant layer contains a propylene homopolymer or a copolymer containing at least propylene and ethylene as a copolymerization component; and
the inside sealant layer is a polymer or a copolymer having a melting point of 130° C. to 160° C. and an MFR of 1 to 25 g/10 min.
2. The molding packaging material according to claim 1 , wherein an equivalent ratio [NCO]/[OH] of an isocyanate group of the multifunctional isocyanate compound to a hydroxyl group constituting the carboxyl group of the polyolefin resin is 1.0 to 10.0.
3. The molding packaging material according to claim 1 , wherein, in the polyolefin resin having a carboxyl group, a melt flow rate (MFR) measured at 130° C. is 5 to 40 g/10 min.
4. A method for manufacturing a molding packaging material, comprising:
a step of subjecting at least one surface of a metallic foil barrier layer to a chemical conversion treatment;
a step of bonding a biaxially oriented polyethylene terephthalate film to another surface of the metallic foil barrier layer with an outside adhesive to form an outside substrate layer;
a step of forming an inside adhesion resin layer on the chemical conversion-treated surface of the metallic foil barrier layer;
a step of laminating and forming an inside sealant layer containing a thermoplastic resin on the inside adhesion resin layer; and
a step of heat treating a laminate obtained by the steps above with a heat roll heated to 130° C. to 220° C. in such a manner that the outside substrate layer is on a side of the heat roll; wherein
the biaxially oriented polyethylene terephthalate film satisfies the following Expressions (I) and (II),
500 MPa≦ MB+TB≦ 700 MPa Expression (I)
| MB−TB|≦ 30 MPa Expression (II)
the MB is a tensile breaking strength in a direction M of the biaxially oriented polyethylene terephthalate film and the TB is a tensile breaking strength in a direction T of the biaxially oriented polyethylene terephthalate film;
the inside adhesion resin layer contains an adhesive containing a multifunctional isocyanate compound and a polyolefin resin having a carboxyl group, which is a modified polyolefin resin of graft polymerized ethylenic unsaturated carboxylic acid or an acid anhydride thereof with polyolefin, or a copolymerization resin of an olefin monomer and ethylenic unsaturated carboxylic acid, such that the inside adhesion resin layer has adhesiveness to both the metallic foil barrier layer and the thermoplastic resin of the inside sealant layer;
the inside sealant layer contains a propylene homopolymer or a copolymer containing at least propylene and ethylene as a copolymerization component; and
the inside sealant layer is a polymer or a copolymer having a melting point of 130° C. to 160° C. and an MFR of 1 to 25 g/10 min.
5. The method for manufacturing a molding packaging material according to claim 4 , wherein an equivalent ratio [NCO]/[OH] of an isocyanate group of the multifunctional isocyanate compound to a hydroxyl group constituting the carboxyl group of the polyolefin resin of 1.0 to 10.0.