Patent US4740421A successfully refreshed from Google Patents.
US4740421A
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US
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Polypropylene composite stretched film
Assignee: JNC Corp
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Filing: 1986-12-22
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Granted: 1988-04-26
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Expires: 2006-12-22
Abstract
Abstract A polypropylene composite stretched film having superior low-temperature heat-sealing characteristics, transparency and anti-block properties is provided, which film comprises as a base layer, a crystalline polypropylene and as a heat-sealing layer, a crystalline ethylene-propylene random copolymer containing 1 to 5% by weight of polymers having a molecular weight (Mw) of 6,000 or less and 3 to 5% by weight of ethylene, or a crystalline ethylene-propylene-butene-1 copolymer containing 1 to 5% by weight of polymers having a Mw of 6,000 or less, 1 to 10% by weight of ethylene and 4 to 30% by weight of butene-1.
Inventors
- 👤 Takeshi Suzuki
- 👤 Nobutoshi Komori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:28
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; C; C08; C08J; C08J5/00; C08J5/18; C09; C09J; C09J123/00; C09J123/02; C09J123/16; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/70; B32B2307/704; B32B2323/00; B32B2323/10; C08J2323/00; C08J2323/02; C08L; C08L2666/00; C08L2666/02; C08L2666/04; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A polypropylene composite stretched film comprising a base layer consisting essentially of a crystalline polypropylene and a heat sealing layer consisting essentially of a crystalline ethylene-propylene-butene- 1 random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 1 to 10% by weight of ethylene and 4 to 30% by weight of butene-1, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of 4% or less.
Claim 2
Dependent Claim
98 words
A polypropylene composite stretched film comprising a base layer consisting essentially of a crystalline polypropylene and a heat sealing layer consisting essentially of a crystalline ethylene-propylene-butene- 1 random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 1 to 10% by weight of ethylene and 4 to 30% by weight of butene-1, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of 4% or less.
Claim 3
Dependent Claim
89 words
A polypropylene composite stretched film comprising a base layer consisting essentially of a crystalline polypropylene and a heat sealing layer consisting essentially of a crystalline ethylene-propylene random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 3 to 15% by weight of ethylene, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of 4% or less.
Claim 4
Dependent Claim
89 words
A polypropylene composite stretched film comprising a base layer consisting essentially of a crystalline polypropylene and a heat sealing layer consisting essentially of a crystalline ethylene-propylene random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 3 to 15% by weight of ethylene, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of 4% or less.
Claim 5
Dependent Claim
34 words
A polypropylene composite stretched film according to claim 1, wherein said ethylene-propylene-butene-1 random copolymer has an ethylene content of 2 to 6% by weight and a butene-1 content of 4 to 20% by weight.
Claim 6
Dependent Claim
28 words
A polypropylene composite stretched film according to claim 2, wherein said crystalline ethylene-propylene random copolymer has an ethylene content in the range of 5 to 11% by weight.
Claim 7
Dependent Claim
36 words
A polypropylene composite stretched film according to claim 1, wherein said crystalline ethylene-propylene-butene-1 random copolymer consists essentially of 1 to 4% by weight of gas-phased polymerization polymers having an average molecular weight of up to 6000.
Claim 8
Dependent Claim
36 words
A polypropylene composite stretched film according to claim 2, wherein said crystalline ethylene-propylene random copolymer consists essentially of 1 to 4% by weight of gas-phased polymerization polymers having an average molecular weight of up to 6000.
Claim 9
Dependent Claim
99 words
A polypropylene composite stretched film comprising (i) a base layer consisting essentially of a crystalline polypropylene and (ii) a heat sealing layer consisting essentially of a crystalline ethylene-propylene-butene-1 random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 1 to 10% by weight of ethylene and 4 to 30% by weight of butene-1, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of less than 3.5%.
Claim 10
Dependent Claim
99 words
A polypropylene composite stretched film comprising (i) a base layer consisting essentially of a crystalline polypropylene and (ii) a heat sealing layer consisting essentially of a crystalline ethylene-propylene-butene-1 random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, 1 to 10% by weight of ethylene and 4 to 30% by weight of butene-1, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of less than 3.5%.
Claim 11
Dependent Claim
92 words
A polypropylene composite stretched film comprising (i) a base layer consisting essentially of a crystalline polypropylene and (ii) a heat sealing layer consisting essentially of a crystalline ethylene-propylene random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, and 3 to 15% by weight of ethylene, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of less than 3.5%.
Claim 12
Dependent Claim
92 words
A polypropylene composite stretched film comprising (i) a base layer consisting essentially of a crystalline polypropylene and (ii) a heat sealing layer consisting essentially of a crystalline ethylene-propylene random copolymer containing 1 to 5% by weight of gas-phased polymerization polymers having a molecular weight of up to 6000, and 3 to 15% by weight of ethylene, each based on the weight of the copolymer, wherein said polypropylene composite stretched film has a heat sealing strength at 120° C. of 80 g/15 mm or more, and a haze percentage of less than 3.5%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |