Clear, autoclavable, sealed container having good water vapor barrier properties and flex crack resistance
First Claim
1. A clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, said container being made of first and second plastic sheets sealed together at their peripheries, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semi-crystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a blended layer consisting essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having rubbery polyolefin blocks consisting essentially of ethylene and butylene units, and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;
said second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, said nonoriented polypropylene being peripherally bonded to said layer of polyolefin of the first plastic sheet.
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Accused Products
Abstract
A clear, flexible, sealed container may be made of first and second plastic sheets sealed together at their peripheries. The first plastic sheet defines a bulge to increase the inside volume of the container, and comprises a laminate of a layer of polyolefin and a blended layer of polyolefin and a block copolymer of polyolefin and polystyrene. The second plastic sheet is a bonded laminate of a layer of biaxially oriented polypropylene and nonoriented polypropylene, peripherally bonded to the layer of polyolefin of the first plastic sheet.
130 Citations
25 Claims
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1. A clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, said container being made of first and second plastic sheets sealed together at their peripheries, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semi-crystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a blended layer consisting essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having rubbery polyolefin blocks consisting essentially of ethylene and butylene units, and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;
said second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, said nonoriented polypropylene being peripherally bonded to said layer of polyolefin of the first plastic sheet. - View Dependent Claims (2, 3, 4, 5, 6, 25)
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
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7. A clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, said container being made of first and second plastic sheets sealed together at their peripheries, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semicrystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a layer selected from the group consisting of flexible nylon and polyester materials to impart crack resistance to said first plastic sheet;
- said second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, said nonoriented polypropylene being peripherally bonded to said layer of polyolefin of the first plastic sheet.
- View Dependent Claims (8, 9, 10, 11)
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12. The method of enclosing an object into a clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, which comprises thermoforming a convex bulge into a first plastic sheet to increase the inside volume of the container to be formed, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semi-crystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a blended layer consisting essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having rubbery polyolefin blocks consisting essentially of ethylene and butylene units, and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;placing said object into the convex bulge defined by the thermoformed plastic sheet; and overlaying said first plastic sheet and said object with a second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, and peripherally heat sealing said first and second layers together about said convex bulge and object to form a sealed container. - View Dependent Claims (13, 14, 15)
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
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16. The method of claim 16 in which said object is a one liter bag of solution.
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17. The method of enclosing an object into a clear autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, which comprises thermoforming the convex bulge into a first plastic sheet to increase the inside volume of the container to be formed, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene and being of semi-cryatalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a layer selected from the group consisting of flexible nylon and polyester materials to impart crack resistance to said first plastic sheet;
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placing said object into the convex bulge defined by the thermoformed plastic sheet; and overlaying said first plastic sheet and said object with a second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, and peripherally heat sealing said first and second layers together about said convex bulge and object to form a sealed container. - View Dependent Claims (18, 19, 20)
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21. A clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, said container being made of first and second plastic sheets sealed together at their peripheries, said first plastic sheet defining a formed bulge to increase the inside volume of said container and comprising a laminate of (1) at least one layer of a polyolefin derived principally from at least one of propylene and ethylene, and being of semi-crystalline characteristic to exhibit low permeability to water vapor, bonded to (2) a blended layer consisting of essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having rubbery polyolefin blocks consisting essentially of ethylene and butylene units and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;
said second plastic sheet comprising a bonded laminate comprising a layer of plastic material selected from the group consisting of relatively nonoriented polypropylene and polyethylene, and a layer of biaxially oriented polyester to serve as structural support during heat sealing and as a water vapor barrier member, said nonoriented polypropylene being peripherally bonded to said layer of polyolefin of the first plastic sheet. - View Dependent Claims (22)
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
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23. The method of enclosing an object into a clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, which comprises thermoforming a convex bulge into a first plastic sheet to increase the inside volume of the container to be formed, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semi-crystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a blended layer consisting essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having rubbery saturated polyolefin blocks and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;placing said object into the convex bulge defined by the thermoformed plastic sheet; and overlaying said first plastic sheet and said object with a second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, and peripherally heat sealing said first and second layers together about said convex bulge and object to form a sealed container.
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
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24. A clear, autoclavable, flexible, sealed container having good water vapor barrier properties and flex crack resistance, said container being made of first and second plastic sheets sealed together at their peripheries, said first plastic sheet comprising a laminate of (1) at least one layer of a polyolefin derived principally from propylene, and being of semi-crystalline characteristic to exhibit a low permeability to water vapor, bonded to (2) a blended layer consisting essentially of 30 to 90 percent by weight of a block copolymer having thermoplastic, rubbery characteristics, and having saturated rubbery polyolefin blocks and blocks of a polystyrene;
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
from 10 to 70 percent by weight of a polyolefin derived principally from at least one of propylene, ethylene, and 4-methylpentene-1, said polyolefin having a Vicat Softening Temperature of above 120°
C.;
said second plastic sheet comprising a bonded laminate comprising a layer of relatively nonoriented polypropylene and a layer of biaxially oriented polypropylene, said nonoriented polypropylene being peripherally bonded to said layer of polyolefin of the first plastic sheet.
- the rubbery polyolefin blocks comprising from 60 to 85 percent by weight of said block copolymer; and
Specification