Patent US3124183A successfully refreshed from Google Patents.
Patent US5252384A successfully refreshed from Google Patents.
US5252384A
Expired / Lapsed
US
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Heat-sealable packaging film
Assignee: Basell Polyolefine GmbH
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Filing: 1991-11-04
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Granted: 1993-10-12
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Expires: 2011-11-04
Abstract
Abstract A polyolefin film which comprises a polypropylene base layer and at least one top layer comprising a propylene polymer, wherein the base layer is formed of an isotactic polypropylene and the top layer of a copolymer of an o-olefin having 2 to 8 carbon atoms and a syndiotactic propylene, has high sealed-seam strength and excellent optical properties and is useful as, for example, a packaging material.
Inventors
- 👤 Lothar Bothe
- 👤 Volker Dolle
- 👤 Andreas Winter
- 👤 Thomas Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:47
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/16; B32B27/18; B32B2323/00; B32B2323/10; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/25; Y10T428/254; Y10T428/258; Y10T428/259; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31725; Y10T428/3175; Y10T428/31757; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
54 words
A multilayer film which comprises; a) a base layer consisting essentially of an isotactic polypropylene, and b) at least one additional layer comprising a copolymer of an α-olefin having 2 to 8 carbon atoms and a syndiotactic propylene, wherein the syndiotactic propylene content of said copolymer has an isotacticity of less than about 15%.
Claim 2
Dependent Claim
54 words
A multilayer film which comprises; a) a base layer consisting essentially of an isotactic polypropylene, and b) at least one additional layer comprising a copolymer of an α-olefin having 2 to 8 carbon atoms and a syndiotactic propylene, wherein the syndiotactic propylene content of said copolymer has an isotacticity of less than about 15%.
Claim 3
Dependent Claim
21 words
A multilayer film as claimed in claim 1, wherein said polypropylene has a melting point of about 140° C. or higher
Claim 4
Dependent Claim
75 words
A multilayer film as claimed in claim 1, wherein said polypropylene is selected from the group consisting of isotactic polypropylene having an n-heptane soluble content of about 15% by weight or less, copolymers of ethylene and propylene having an ethylene content of about 10% by weight or less, and copolymers of polypropylene and (C 4 -C 8 ) α-olefins having a (C 4 -C 8 ) α-olefin content of about 10% by weight or less.
Claim 5
Dependent Claim
51 words
A multilayer film as claimed in claim 1, wherein said base layer contains inert particles having a mean particle diameter of about 0.01 to about 5 μm, said particles being selected from the group consisting of calcium carbonate, aluminum silicate, silicon dioxide, titanium dioxide, polyethylene terephthalate, polybutylene terephthalate, and mixtures thereof.
Claim 6
Dependent Claim
20 words
A multilayer film as claimed in claim 1, wherein said copolymer comprises more than about 70% by weight of propylene.
Claim 7
Dependent Claim
16 words
A multilayer film as claimed in claim 1, wherein said isotacticity is less than about 6%.
Claim 8
Dependent Claim
15 words
A multilayer film as claimed in claim 1, wherein said α-olefin is ethylene or 1-butene.
Claim 9
Dependent Claim
28 words
A multilayer film as claimed in claim 1, wherein the mean length of sequence n r of the syndiotactic sequences of said copolymer is greater than about 20.
Claim 10
Dependent Claim
19 words
A multilayer film as claimed in claim 8, wherein said mean length of sequences is greater than about 25.
Claim 11
Dependent Claim
61 words
A multilayer film as claimed in claim 1, wherein the molar mass distribution of said copolymer corresponds to the following relation: M.sub.w =k·M.sub.n, where M w stands for the weight average of the molar mass distribution, M n stands for the number average of the molar mass distribution and k is a factor which is between about 1 and about 5.
Claim 12
Dependent Claim
17 words
A multilayer film as claimed in claim 10, wherein k is between about 2 and about 3.
Claim 13
Dependent Claim
20 words
A multilayer film as claimed in claim 1, comprising a layer (b) on either side of said base layer (a).
Claim 14
Dependent Claim
21 words
A multilayer film as claimed in claim 12, additionally comprising at least one barrier layer comprising metal, polyamide, or polyvinyl alcohol.
Claim 15
Dependent Claim
19 words
A multilayer film as claimed in claim 12 comprising one barrier layer on either side of each layer (b).
Claim 16
Dependent Claim
41 words
A multilayer film as claimed in claim 1, wherein at least one of said base layer and said additional layer contains an additive selected from the group consisting of antistatic agents, antiblocking agents, lubricants, stabilizers, low-molecular weight resins, and mixtures thereof.
Claim 17
Dependent Claim
30 words
A multilayer film as claimed in claim 15, wherein said additive is selected from the group consisting of an N,N-bis-(2-hydroxyethyl)-(C 10 -C 20 )-alkylamine, a polyether-modified polydiorganosiloxane, and mixtures thereof.
Claim 18
Dependent Claim
26 words
A multilayer film as claimed in claim 1, wherein at least one of said additional layers has been surface-treated to render it receptive to printing inks.
Claim 19
Dependent Claim
19 words
A multilayer film as claimed in claim 17, wherein the surface treatment comprises corona, flame, or polarized flame treatment.
Claim 20
Dependent Claim
22 words
A multilayer film as claimed in claim 17, wherein the treated surface has a surface polarity of more than about 36 mN/m.
Claim 21
Dependent Claim
14 words
A multilayer film as claimed in claim 1, wherein said film is biaxially oriented.
Claim 22
Dependent Claim
15 words
A multilayer film as claimed in claim 1, wherein said isotatic polypropylene comprises a homopolymer.
Claim 23
Dependent Claim
23 words
A multilayer film as claimed in claim I, wherein said copolymer consists of at least one of said α-olefins and said syndiotactic polypropylene.
Claim 24
Dependent Claim
12 words
A packaging film comprising a multilayer film as claimed in claim 1.
Claim 25
Dependent Claim
109 words
A multilayer film which comprises: a) a base layer consisting essentially of an isotactic polypropylene selected from the group consisting of a polypropylene having an n-heptene soluble content of about 15% by weight or less, copolymers of ethylene and propylene having an ethylene content of about 10% by weight or less, and copolymers of propylene and (C 4 -C 8 ) α-olefins having a (C 4 -C 8 ) α-olefin content of about 10% by weight or less, and b) at least one additional layer comprising a copolymer of an α-olefin having 2 to 8 carbon atoms and a syndiotatic propylene having an isotacticity of less than about 15%.
Claim 26
Dependent Claim
109 words
A multilayer film which comprises: a) a base layer consisting essentially of an isotactic polypropylene selected from the group consisting of a polypropylene having an n-heptene soluble content of about 15% by weight or less, copolymers of ethylene and propylene having an ethylene content of about 10% by weight or less, and copolymers of propylene and (C 4 -C 8 ) α-olefins having a (C 4 -C 8 ) α-olefin content of about 10% by weight or less, and b) at least one additional layer comprising a copolymer of an α-olefin having 2 to 8 carbon atoms and a syndiotatic propylene having an isotacticity of less than about 15%.
Claim 27
Dependent Claim
32 words
A multilayer film as claimed in claim 24, wherein said isotatic polypropylene has an isotacticity of greater than about 95% and said syndiotactic propylene has an isotacticity of less than about 6%.
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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) | 1996-10-11 | 1997-04-12 | 1997-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-11 | 2001-04-12 | 2001-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-11 | 2005-04-12 | 2005-10-12 | $7700.00 | Window Closed / Lapsed |