Coinjection stretch-blow molded container
AssigneeKuraray Co., Ltd.
InventorsShinji Tai, Hiroyuki Shimo
Life of this patent
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Abstract
Multi-layered, coinjection stretch-blow molded containers are obtained by stretch-blow molding a preform prepared by coinjection molding a polyester resin and an EVOH resin blend in which one of the EVOH resins is dispersed as particles in an EVOH resin matrix. Containers prepared with this EVOH blend have good impact delamination resistance, good gas-barrier properties, and high transparency is high, even without an adhesive layer. The EVOH blend is composed of two EVOH resins having different ethylene contents and degrees of saponification. The blend exhibits at least two crystal fusion peaks by DSC.
Claims13
A container comprising:
- at least one layer comprising a thermoplastic polyester, and
- at least one layer comprising a mixture of two ethylene-vinyl alcohol copolymers B1 and B2,
- wherein said mixture of B1 and B2 has a morphology in which particles of B2 are dispersed in B1, said mixture of B1 and B2 exhibits at least two crystal fusion peaks in its differential scanning calorimetry (DSC) and satisfies the following formulae (1) to (7):
- 60/40≦WB1/WB2≦90/10 (1)
- 25≦ETB1≦40 (2)
- 99≦SDB1 (3)
- 35≦ETB2≦48 (4)
- 92≦SDB2≦99 (5)
- 10≦ETB2−ETB1≦23 (6)
- 1≦SDB1−SDB2≦8 (7)
- and,
- WB1 is the amount by weight of B1 in the mixture,
- WB2 is the amount by weight of B2 in the mixture,
- ETB1 is the mol % ethylene in B1,
- ETB2 is the mol % ethylene in B2,
- SDB1 is the % saponification of B1, and
- SDB2 is the % saponification of B2.
A preform for a container comprising:
- at least one layer comprising a thermoplastic polyester, and
- at least one layer comprising a mixture of two ethylene-vinyl alcohol copolymers B1 and B2,
- wherein said mixture of B1 and B2 has a morphology in which particles of B2 are dispersed in B1, said mixture of B1 and B2 exhibits at least two crystal fusion peaks in its differential scanning calorimetry (DSC) and satisfies the following formulae (1) to (7):
- 60/40≦WB1/WB2≦90/10 (1)
- 25≦ETB1≦40 (2)
- 99≦SDB1 (3)
- 35≦ETB2≦48 (4)
- 92≦SDB2≦99 (5)
- 10≦ETB2−ETB1≦23 (6)
- 1≦SDB1−SDB2≦8 (7)
- and,
- WB1 is the amount weight of B1 in the mixture,
- WB2 is the amount by weight of B2 in the mixture,
- ETB1 is the mol % ethylene in B1,
- ETB2 is the mol % ethylene in B2,
- SDB1 is the % saponification of B1, and
- SDB2 is the % saponification of B2.
Dependencies are inferred from the claim text.