Abstract: [Problems to be Solved] To coat homopolyethylene terephthalate, which is inexpensive and easily available, on a paper base material directly, not via an adhesive layer, by extrusion coating, thereby providing a paper laminate having heat sealability and having a homopolyethylene terephthalate coating of a uniform film thickness formed thereon. [Means to Solve the Problems] A method for producing a paper laminate having a coating comprising homopolyethylene terephthalate formed on at least one surface of a paper base material by extrusion coating is characterized in that an air gap L, expressed as a distance from a lip opening of a T-die to a paper base material B, is 25 cm or less.

Abstract: The present invention relates to a laminate comprising at least three layers, paper/polyethylene/polyethylene terephthalate, wherein the polyethylene terephthalate is directly coated on the polyethylene surface, with no adhesive layer or the like being interposed, and the polyethylene terephthalate layer has heat sealability; and a method for producing a laminate having polyethylene coated on at least one surface of a paper substrate, the method involving extrusion laminating polyethylene terephthalate onto a surface of the polyethylene, wherein an air gap expressed as the distance from a lip opening of a die to the polyethylene surface is 25 cm or less.

Abstract: The present invention relates to a laminate comprising at least three layers, paper/polyethylene/polyethylene terephthalate, wherein the polyethylene terephthalate is directly coated on the polyethylene surface, with no adhesive layer or the like being interposed, and the polyethylene terephthalate layer has heat sealability; and a method for producing a laminate having polyethylene coated on at least one surface of a paper substrate, the method involving extrusion laminating polyethylene terephthalate onto a surface of the polyethylene, wherein an air gap expressed as the distance from a lip opening of a die to the polyethylene surface is 25 cm or less.

Abstract: [Problems to be Solved] To coat homopolyethylene terephthalate, which is inexpensive and easily available, on a paper base material directly, not via an adhesive layer, by extrusion coating, thereby providing a paper laminate having heat sealability and having a homopolyethylene terephthalate coating of a uniform film thickness formed thereon. [Means to Solve the Problems] A method for producing a paper laminate having a coating comprising homopolyethylene terephthalate formed on at least one surface of a paper base material by extrusion coating is characterized in that an air gap L, expressed as a distance from a lip opening of a T-die to a paper base material B, is 25 cm or less.

Abstract: A paperboard material 101 is mainly composed of a paperboard having a weight of 200 to 450 g/m.sup.2, a density of 0.65 to 0.82 and a gas permeability of 50 to 200 sec. A first resin layer having liquid-impermeability and thermal resistance is formed entirely on the surface of the paperboard on the inner side of the receptacle, and a second resin layer having permeability to gas and liquid is formed entirely on the back surface of the paperboard. Radial score lines 117 are formed in the portion corresponding to the corners of the paperboard material 101 toward its outer periphery. The score lines 117 do not reach the outer periphery of the paperboard material 101 but terminate at the position at a distance "a" (1 to 3 mm). The score lines 117 are formed by pressing the paperboard with a pressing die from the side constituting the inner side of the receptacle toward the outer side.