发明名称 |
Heat-shrinkable multi-layer film for deep-draw forming, and process for production thereof |
摘要 |
A polyamide resin-based heat-shrinkable multilayer film having excellent heat shrinkability and strength, as well as a high degree of deep A polyamide resin-based heat-shrinkable multilayer film having excellent heat shrinkability and strength, as well as a high degree of deep drawability as represented a shorter side-basis draw ratio (D/L) in excess of 0.6 between a maximum draw depth (D) and a shorter side length (L) of a mold opening is provided. The multilayer film is characterized by including a surface layer (a) comprising a thermoplastic resin, an intermediate layer (b) comprising a polyamide resin, and a surface layer (c) comprising a sealable resin, wherein (A) the intermediate layer (b) comprises a mixture of an aliphatic polyamide having a melting point of at least 180° C., and an amorphous aromatic polyamide comprising a polycondensation product of an aliphatic diamine with is ophthalmic acid and terephthalic acid as main acid components, including 25-45 wt. % of the amorphous aromatic polyamide, and has a thickness exceeding 25% and at most 50% of a total thickness of whole layers, and exhibiting: (B) tensile stresses at an elongation of 100% as measured in a tensile test at 100° C., including 3-22 N in at least one of a longitudinal direction (MD) and a transverse direction (TD) and an average of MD and TD values of 3-20N, and (C) a shrinkage in hot water at 90° C. of 3 to 20% in each of MD and TD. The film is produced through a process of strictly controlling biaxial stretching ratios and heat-relaxation ratios. |
申请公布号 |
US9352395(B2) |
申请公布日期 |
2016.05.31 |
申请号 |
US201013520888 |
申请日期 |
2010.12.17 |
申请人 |
KUREHA CORPORATION |
发明人 |
Ueyama Takahisa;Itoh Tadayoshi;Sekiya Yuta |
分类号 |
B29C55/16;B32B27/08;B32B27/32;B32B27/34;B32B27/36;B23B27/08 |
主分类号 |
B29C55/16 |
代理机构 |
Birch, Stewart, Kolasch & Birch, LLP |
代理人 |
Birch, Stewart, Kolasch & Birch, LLP |
主权项 |
1. A heat-shrinkable multilayer film adapted for deep draw forming, comprising: a surface layer (a) comprising a thermoplastic resin, an intermediate layer (b) comprising a polyamide resin, and a surface layer (c) comprising a sealable resin, wherein,
(A) the intermediate layer (b) comprises a mixture of an aliphatic polyamide having a melting point of at least 180° C., and an amorphous aromatic polyamide comprising a polycondensation product of an aliphatic diamine with isophthalic acid and terephthalic acid as main acid components, including 25-45 wt. % of the amorphous aromatic polyamide, and has a thickness exceeding 25% and at most 50% of a total thickness of whole layers, and the multilayer film exhibits: (B) tensile stresses at an elongation of 100% as measured in a tensile test at 100° C., including 3-22 MPa in at least one of a longitudinal direction (MD) and a transverse direction (TD) and an average of MD and TD values of 3-20 MPa, and (C) a shrinkage in hot water at 90° C. of 3 to 20% in each of MD and TD. |
地址 |
Tokyo JP |