Heat-Shrinkable Laminated Film, Molded Product and Heat-Shrinkable Label Employing the Film, and Container

Abstract

The present invention provides a heat-shrinkable laminated film, which exhibits excellent film rigidity, shrink finishing quality, transparency of the recycled film, and a small natural shrinkage, with suppressed film interlayer peeling and shrinking stress, and which is applicable to shrinkable packing, shrinkable bond-packing, shrinkable label and the like. The heat-shrinkable laminated film comprises: a surface layer (S layer) composed of a polyester series resin composition containing a polyvalent carboxylic acid residue and a polyvalent alcohol residue; a middle layer (M layer) composed of a styrene series resin composition; and an adhesive layer (AD layer) which contains a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon or hydrogenated derivatives thereof, and having a styrene series hydrocarbon content rate to the entire copolymer or hydrogenated derivatives is 5˜40 mass % or less. An elongation modulus of the film in a direction perpendicular to a main shrinking direction of the film is 1200 MPa or more, and a shrinking stress in the main shrinking direction of the film is 8 MPa or less or a rupture elongation at 23° C. is 40% or more.

1 . A heat-shrinkable laminated film comprising: 
 a surface layer (S layer) comprising a polyester series resin composition comprising a polyvalent carboxylic acid residue and a polyvalent alcohol residue;    a middle layer (M layer) comprising a styrene series resin composition; and    an adhesive layer (AD layer) comprising a resin composition containing a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon or hydrogenated deriviatives thereof, and having a styrene series hydrocarbon content rate in the copolymer or hydrogenated derivatives thereof is 5 mass % or more and 40 mass % or less,    wherein the respective layers further comprise compositions comprised mainly of the following components; an elongation modulus of the heat-shrinkable laminated film in a direction perpendicular to a film's main shrinking direction measured in accordance with JIS K7127 is 1200 MPa or more; and maximum shrinking stress in the main shrinking direction of the heat-shrinkable laminated film being dipped in 90° C. silicone oil for 10 seconds is 8 MPa or less.    
     
     
         2 . A heat-shrinkable laminated film comprising: 
 a surface layer (S layer) comprising a polyester series resin composition containing a polyvalent carboxylic acid residue and a polyvalent alcohol residue;    a middle layer (M layer) comprising a styrene series resin composition; and    an adhesive layer (AD layer) comprising a resin composition containing a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon or hydrogenated derivatives thereof, and having a styrene series hydrocarbon content rate in the copolymer or hydrogenated derivatives thereof is 5 mass % or more and 40 mass % or less.    wherein the respective layers further comprise compositions comprising mainly of the following components; the heat-shrinkable laminated film is elongated at least twice or more and 7 times or less in one axial direction at 60° C. or more and 120° C. or less; an elongation modulus of the heat-shrinkable laminated film in a direction perpendicular to a film's main shrinking direction measured in accordance with JIS K7127 is 1200 MPa or more; and maximum shrinking stress in the main shrinking direction of the said heat-shrinkable laminated film being dipped in 90° C. silicone oil for 10 seconds is 8 MPa or less.    
     
     
         3 . A heat-shrinkable laminated film according to  claim 1 , wherein maximum shrinking stress in the main shrinking direction of the laminated film being dipped in 90° C. silicone oil for 10 seconds is 5 MPa or more and 8 MPa or less.  
     
     
         4 . A heat-shrinkable laminated film according to  claim 1 , wherein the polyester series resin composition constituting the surface layer (S layer) contains amorphous polyethylene terephthalate series resin as a main component which comprises aromatic dicarboxylic residue and diol residue, wherein the diol residue contains 15 mole % or more and 50 mole % or less of 1,4-cyclohexane dimethanol residue in total diol residue.  
     
     
         5 . A heat-shrinkable laminated film comprising: a surface layer (S layer) comprising a resin composition consisting of an amorphous polyester series resin containing a polyvalent carboxylic acid residue and a polyvalent alcohol residue, and 1 part by mass or more and 40 parts by mass or less of crystalline polyester series resin to 100 parts by mass of the amorphous polyester series resin; 
 a middle layer (M layer) comprising a styrene series resin composition; and    an adhesive layer (AD layer) comprising a resin composition containing a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon or hydrogenated derivatives thereof, and having a styrene series hydrocarbon content rate in the copolymer or hydrogenated derivatives thereof is 5 mass % or more and 40 mass % or less,    wherein the respective layers further comprise following components; an elongation modulus of the heat-shrinkable laminated film in a direction perpendicular to a film's main shrinking direction measured in accordance with JIS K7127 is 1200 MPa or more; and rupture elongation in the film's main shrinking direction measured at 23° C. in accordance with JIS K7127 is 40% or more.    
     
     
         6 . A heat-shrinkable laminated film according to  claim 1 , wherein the middle layer (M layer) contains 1 part by mass or more and 100 parts by mass or less of resin composition constituting the surface layer (S layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         7 . A heat-shrinkable laminated film according to  claim 1 , wherein the middle layer (M layer) contains 1 part by mass or more and 30 parts by mass or less of resin composition constituting the adhesive layer (AD layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         8 . A heat-shrinkable laminated film according to  claim 5 , wherein the amorphous polyester series resin constituting the surface layer (S layer) is amorphous polyethylene terephthalate which comprises aromatic dicarboxylic residue and diol residue, wherein the diol residue contains 15 mole % or more and 50 mole % or less of 1,4-cyclohexane dimethanol residue in total diol residue.  
     
     
         9 . A heat-shrinkable laminated film according to  claim 5 , wherein the crystalline polyester series resin constituting the surface layer (S layer) is at least any one of resins selected from a group consisting of: polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polyethylene terephthalate-isophthalate copolymer resin, polyethylene terephthalate-neopentyl terephthalate copolymer resin, polybutylene terephthalate-ether copolymer resin, polybutylene terephthalate-isophthalate copolymer resin, and polytrimethylene terephthalate.  
     
     
         10 . A heat-shrinkable laminated film according to  claim 1 , wherein styrene series resin composition constituting the middle layer (M layer) is selected from a group consisting of: a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon; a copolymer of the copolymer with a monomer copolymerable with the styrene series hydrocarbon or the conjugated dienic hydrocarbon; or mixtures thereof.  
     
     
         11 . A heat-shrinkable laminated film according to  claim 1 , wherein a glass transition temperature of copolymer of a styrene series hydrocarbon and a conjugated dienic hydrocarbon, or hydrogenated derivatives thereof, which constitutes the adhesive layer (AD layer), is 20° C. or less.  
     
     
         12 . A heat-shrinkable laminated film according to  claim 1 , wherein haze measured in accordance with JIS K7105 is 10% or less.  
     
     
         13 . A heat-shrinkable laminated film according to  claim 1 , wherein a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 70° C. water for 10 seconds is 10% or more and 40% or less, and a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 80° C. water for 10 seconds is 30% or more and 70% or less.  
     
     
         14 . A heat-shrinkable laminated film according to  claim 1 , thickness ratio of the surface layer (S layer) to total film thickness is 10% or more and 70% or less.  
     
     
         15 . A heat-shrinkable laminated film according to  claim 1 , wherein rupture elongation of the film at −5° C. measured in accordance with JIS K7127 after 30 days storage at 30° C. is 100% or more.  
     
     
         16 . A molded product employing the heat-shrinkable laminated film as defined in  claim 1  as the base material.  
     
     
         17 . A heat-shrinkable label employing the heat-shrinkable laminated film as defined in  claim 1  as the base material.  
     
     
         18 . A container provided with the molded product as defined in  claim 16 .  
     
     
         19 . A container provided with the heat-shrinkable label as defined in  claim 17 .  
     
     
         20 . A heat-shrinkable laminated film according to  claim 2 , wherein the middle layer (M layer) contains 1 part by mass or more and 100 parts by mass or less of resin composition constituting the surface layer (S layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         21 . A heat-shrinkable laminated film according to  claim 2 , wherein the middle layer (M layer) contains 1 part by mass or more and 30 parts by mass or less of resin composition constituting the adhesive layer (AD layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         22 . A heat-shrinkable laminated film according to  claim 2 , wherein the amorphous polyester series resin constituting the surface layer (S layer) is amorphous polyethylene terephthalate which comprises aromatic dicarboxylic residue and diol residue, wherein the diol residue contains 15 mole % or more and 50 mole % or less of 1,4-cyclohexane dimethanol residue in total diol residue.  
     
     
         23 . A heat-shrinkable laminated film according to  claim 2 , wherein styrene series resin composition constituting the middle layer (M layer) is selected from a group consisting of: a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon; a copolymer of the copolymer with a monomer copolymerable with the styrene series hydrocarbon or the conjugated dienic hydrocarbon; or mixtures thereof.  
     
     
         24 . A heat-shrinkable laminated film according to  claim 2 , wherein a glass transition temperature of copolymer of a styrene series hydrocarbon and a conjugated dienic hydrocarbon, or hydrogenated derivatives thereof, which constitutes the adhesive layer (AD layer), is 20° C. or less.  
     
     
         25 . A heat-shrinkable laminated film according to  claim 2 , wherein haze measured in accordance with JIS K7105 is 10% or less.  
     
     
         26 . A heat-shrinkable laminated film according to  claim 2 , wherein a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 70° C. water for 10 seconds is 10% or more and 40% or less, and a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 80° C. water for 10 seconds is 30% or more and 70% or less.  
     
     
         27 . A heat-shrinkable laminated film according to  claim 2 , wherein thickness ratio of the surface layer (S layer) to total film thickness is 10% or more and 70% or less.  
     
     
         28 . A heat-shrinkable laminated film according to  claim 2 , wherein rupture elongation of the film at −5° C. measured in accordance with JIS K7127 after 30 days storage at 30° C. is 100% or more.  
     
     
         29 . A heat-shrinkable laminated film according to  claim 5 , wherein the middle layer (M layer) contains 1 part by mass or more and 100 parts by mass or less of resin composition constituting the surface layer (S layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         30 . A heat-shrinkable laminated film according to  claim 5 , wherein the middle layer (M layer) contains 1 part by mass or more and 30 parts by mass or less of resin composition constituting the adhesive layer (AD layer) to 100 parts by mass of resin composition composing the middle layer (M layer).  
     
     
         31 . A heat-shrinkable laminated film according to  claim 5 , wherein the amorphous polyester series resin constituting the surface layer (S layer) is amorphous polyethylene terephthalate which comprises aromatic dicarboxylic residue and diol residue, wherein the diol residue contains 15 mole % or more and 50 mole % or less of 1,4-cyclohexane dimethanol residue in total diol residue.  
     
     
         32 . A heat-shrinkable laminated film according to  claim 5 , wherein styrene series resin composition constituting the middle layer (M layer) is selected from a group consisting of: a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon; a copolymer of the copolymer with a monomer copolymerable with the styrene series hydrocarbon or the conjugated dienic hydrocarbon; or mixtures thereof.  
     
     
         33 . A heat-shrinkable laminated film according to  claim 5 , wherein a glass transition temperature of copolymer of a styrene series hydrocarbon and a conjugated dienic hydrocarbon, or hydrogenated derivatives thereof, which constitutes the adhesive layer (AD layer), is 20° C. or less.  
     
     
         34 . A heat-shrinkable laminated film according to  claim 5 , wherein haze measured in accordance with JIS K7105 is 10% or less.  
     
     
         35 . A heat-shrinkable laminated film according to  claim 5 , wherein a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 70° C. water for 10 seconds is 10% or more and 40% or less, and a heat shrinking ratio in the main shrinking direction of the heat-shrinkable laminated film dipped in 80° C. water for 10 seconds is 30% or more and 70% or less.  
     
     
         36 . A heat-shrinkable laminated film according to  claim 5 , wherein thickness ratio of the surface layer (S layer) to total film thickness is 10% or more and 70% or less.  
     
     
         37 . A heat-shrinkable laminated film according to  claim 5 , wherein rupture elongation of the film at −5° C. measured in accordance with JIS K7127 after 30 days storage at 30° C. is 100% or more.