Heat-shrinkable film of polylactic acid film
View Patent ↗The heat shrinkable film of polylactic acid-based resin used for shrink packaging, shrink bundling, shrink label and the like, can prevent shrinking in the machinery direction after stretching and can show a good appearance after shrinking. The heat shrinkable film of polylactic acid-based resin comprises at least one layer formed by using mainly a resin composition which contains polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 170° C. and a glass transition temperature of 0° C. or less, in which the heat shrinkable film of polylactic acid-based resin is stretched in at least one direction.
1. A heat shrinkable film of polylactic acid-based resin, comprising: at least one layer being stretched in at least one direction;
wherein said layer is formed by using mainly a resin composition which contains polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 140° C. and a glass transition temperature of 0° C. or less, and wherein said resin composition further contains aliphatic polyester “B” having a melting point of 50° C. to 100° C.; and
wherein a degree of shrinkage in the main shrinkage direction of said heat shrinkable film after performing heat-treatment with hot water at 80° C. for 10 seconds, is 30% or more.
2. The heat shrinkable film of polylactic acid-based resin according to claim 1 , wherein said aliphatic polyester “A” has a glass transition temperature of −20° C. or less.
3. The heat shrinkable film of polylactic acid-based resin according to claim 1 , wherein said aliphatic polyester “A” has a melt viscosity of MFR (Melt Flow Rate at 190° C.) of 1 to 40.
4. The heat shrinkable film of polylactic acid-based resin according to claim 1 , wherein said resin composition contains 50 to 90% by mass of polylactic acid-based resin having a proportion in mass ratio of D-lactic acid to L-lactic acid within the range from 98:2 to 85:15, or from 2:98 to 15:85, and 10 to 40% by mass of aliphatic polyester “A”.
5. A heat shrinkable film of polylactic acid-based resin, comprising: at least one layer being stretched in at least one direction;
wherein said layer is formed by using mainly a resin composition which contains polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 170° C. and a glass transition temperature of 0° C. or less;
wherein a degree of shrinkage in the main shrinkage direction of said heat shrinkable film, after performing heat-treatment with hot water at 80° C. for 10 seconds, is 30% or more;
wherein said resin composition contains 50 to 90% by mass of polylactic acid-based resin having a proportion in mass ratio of D-lactic acid to L-lactic acid within the range from 98:2 to 85:15, or from 2:98 to 15:85, and 10 to 40% by mass of aliphatic polyester “A”; and
wherein said resin composition further contains aliphatic polyester “B” having a melting point of 50° C. to 100° C.
6. The heat shrinkable film of polylactic acid-based resin according to claim 5 , wherein said resin composition contains 5 to 20% by mass of said aliphatic polyester “B”.
7. The heat shrinkable film of polylactic acid-based resin according to claim 5 comprising an intermediate layer formed by using mainly said resin composition containing mainly polylactic acid-based resin and aliphatic polyester “A,” and at least one outer layer containing 90% by mass or more of polylactic acid.
8. A heat shrinkable film of polylactic acid-based resin comprising: an intermediate layer and an outer layer, at least one layer of said film being stretched in at least one direction;
wherein a degree of shrinkage in the main shrinkage direction of said heat shrinkable film, after performing heat-treatment with hot water at 80° C. for 10 seconds, is 30% or more;
wherein said intermediate layer is formed by using mainly a resin composition containing mainly polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 170° C. and a glass transition temperature of 0° C. or less;
wherein said resin composition contains 50 to 90% by mass of polylactic acid-based resin having a proportion in mass ratio of D-lactic acid to L-lactic acid within the range from 98:2 to 85:15, or from 2:98 to 15:85, and 10 to 40% by mass of aliphatic polyester “A”; and
wherein said outer layer contains 90% by mass or more of polylactic acid.
9. The heat shrinkable film of polylactic acid-based resin according to claim 8 , wherein said outer layer has a thickness of 1 μm or more.
10. A heat shrinkable film of polylactic acid-based resin, comprising: at least one layer being stretched in at least one direction;
wherein said layer is formed by using mainly a resin composition which contains polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 170° C. and a glass transition temperature of 0° C. or less;
wherein a degree of shrinkage in the main shrinkage direction of said heat shrinkable film, after performing heat-treatment with hot water at 80° C. for 10 seconds, is 30% or more; and
wherein said resin composition further contains aliphatic polyester “B” having a melting point of 50° C. to 100° C.
11. The heat shrinkable film of polylactic acid-based resin according to claim 10 , wherein said resin composition contains 5 to 20% by mass of said aliphatic polyester “B”.
12. The heat shrinkable film of polylactic acid-based resin according to claim 10 , wherein the degree of longitudinal shrinkage after treating with hot-water at 80° C. for 10 seconds is 7% or less.
13. The heat shrinkable film of polylactic acid-based resin according to claim 10 , wherein the degree of longitudinal shrinkage after treating with hot-water at 80° C. for 10 seconds is 5% or less.
14. The heat shrinkable film of polylactic acid-based resin according to claim 10 , wherein said aliphatic polyester “A” has a glass transition temperature of −20° C. or less.
15. The heat shrinkable film of polylactic acid-based resin according to claim 10 , wherein said aliphatic polyester “A” has a melt viscosity of MFR (Melt Flow Rate at 190° C.) of 1 to 40.
16. A heat shrinkable film of polylactic acid-based resin, comprising: an intermediate layer and an outer layer, at least one layer of said film being stretched in at least one direction;
wherein said intermediate layer is formed by using mainly a resin composition which contains polylactic acid-based resin and aliphatic polyester “A” having a melting point of 100 to 170° C. and a glass transition temperature of 0° C. or less;
wherein a degree of shrinkage in the main shrinkage direction of said heat shrinkable film, after performing heat-treatment with hot water at 80° C. for 10 seconds, is 30% or more; and
wherein said outer layer contains 90% by mass or more of polylactic acid.
17. The heat shrinkable film of polylactic acid-based resin according to claim 16 , wherein said outer layer has a thickness of 1 μm or more.
18. The heat shrinkable film of polylactic acid-based resin according to claim 16 , wherein the degree of longitudinal shrinkage after treating with hot water at 80° C. for 10 seconds is 7% or less.
19. The heat shrinkable film of polylactic acid-based resin according to claim 16 , wherein the degree of longitudinal shrinkage after treating with hot water at 80° C. for 10 seconds is 5% or less.
20. The heat shrinkable film of polylactic acid-based resin according to claim 14 , wherein said aliphatic polyester “A” has a glass transition temperature of −20° C. or less.
21. The heat shrinkable film of polylactic acid-based resin according to claim 16 , wherein said aliphatic polyester “A” has a melt viscosity of MFR (Melt Flow Rate at 190° C.) of 1 to 40.