Gas-barrier multilayer body and packaging bag
Provided is a gas barrier laminate being capable of hermetic sealing by heat sealing and having a paper substrate and a vapor-deposited layer, in which the paper substrate has a basis weight of 30 to 100 g/m 2 , and the water vapor transmission rate and the oxygen transmission rate of the gas barrier laminate are in specific ranges, respectively.
1 . A gas barrier laminate being capable of hermetic sealing by heat sealing, the gas barrier laminate comprising a paper substrate and a vapor-deposited layer,
wherein the paper substrate has a basis weight of 30 to 100 g/m 2 ;
a water vapor transmission rate is 3 g/m 2 day or less at 40° C. and 90% RH, and an oxygen transmission rate is 2 cc/m 2 /d/atm or less at 30° C. and 70% RH;
the water vapor transmission rate obtained by folding the gas barrier laminate with the paper substrate placed on an outer side, rolling a roller having a weight of 2 kg thereon one time, opening a fold, and making measurement, is 4 g/m 2 day or less at 40° C. and 90% RH, and the oxygen transmission rate obtained in a same manner is 5 cc/m 2 /d/atm or less at 30° C. and 70% RH;
the water vapor transmission rate obtained by folding the gas barrier laminate with the paper substrate placed on an inner side, rolling a roller having a weight of 2 kg thereon one time, opening a fold, and making measurement, is 4 g/m 2 day or less at 40° C. and 90% RH, and the oxygen transmission rate obtained in a same manner is 5 cc/m 2 /d/atm or less at 30° C. and 70% RH;
a weight of the paper substrate is 47% by mass or more with respect to a gross weight of the gas barrier laminate,
wherein the gas barrier laminate further comprises a polyolefin layer in direct contact with a surface of the vapor-deposited layer on an opposite side from the paper substrate, the polyolefin layer including a polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester.
2 . The gas barrier laminate according to claim 1 , wherein the weight of the paper substrate is 60% by mass or more with respect to the gross weight of the gas barrier laminate.
3 . The gas barrier laminate according to claim 1 , further comprising a layer including a polyvinyl alcohol-based resin between the paper substrate and the vapor-deposited layer.
4 . A gas barrier laminate being capable of hermetic sealing by heat sealing, the gas barrier laminate comprising a paper substrate and a vapor-deposited layer,
wherein the paper substrate has a basis weight of 30 to 100 g/m 2 ;
a water vapor transmission rate is 3 g/m 2 day or less at 40° C. and 90% RH, and an oxygen transmission rate is 2 cc/m 2 /d/atm or less at 30° C. and 70% RH;
the water vapor transmission rate obtained by folding the gas barrier laminate with the paper substrate placed on an outer side, rolling a roller having a weight of 2 kg thereon one time, opening a fold, and making measurement, is 4 g/m 2 day or less at 40° C. and 90% RH, and the oxygen transmission rate at 30° C. and 70% RH obtained in a same manner is 5 cc/m 2 /d/atm or less;
the water vapor transmission rate at 40° C. and 90% RH obtained by folding the gas barrier laminate with the paper substrate placed on an inner side, rolling a roller having a weight of 2 kg thereon one time, opening a fold, and making measurement, is 4 g/m 2 day or less, while the oxygen transmission rate at 30° C. and 70% RH obtained in a same manner is 5 cc/m 2 /d/atm or less; and
a thickness of the paper substrate is 60% or more with respect to the entire gas barrier laminate,
wherein the gas barrier laminate further comprises a polyolefin layer in direct contact with a surface of the vapor-deposited layer on an opposite side from the paper substrate, the polyolefin layer including a polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester.
5 . The gas barrier laminate according to claim 4 , wherein the thickness of the paper substrate is 70% or more of the thickness of the entire gas barrier laminate.
6 . The gas barrier laminate according to claim 4 , further comprising a layer including a polyvinyl alcohol-based resin between the paper substrate and the vapor-deposited layer.
7 . A packaging bag comprising the gas barrier laminate according to claim 1 , the packaging bag having a heat seal strength of 3 N/15 mm or more.
8 . The packaging bag according to claim 7 , having a folded part.
9 . A packaging bag comprising the gas barrier laminate according to claim 4 , the packaging bag having a heat seal strength of 3 N/15 mm or more.
10 . The packaging bag according to claim 9 , having a folded part.