US5277970A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealable white film made of polyolefins
Assignee: Hoechst AG
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Filing: 1992-06-05
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Granted: 1994-01-11
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Expires: 2012-06-05
Abstract
Abstract A multilayered, white, biaxially-oriented polypropylene film is disclosed. The film has an at least three-layered build-up and has a base layer comprised of propylene polymers comprising up to 2% by weight of calcium carbonate having an average particle size of not more than 2.0 μm and 0 to 25% be weight of titanium dioxide, an intermediate layer comprised of propylene polymers comprising 0 to 25% by weight of titanium dioxide, relative to the total weight of the intermediate layer; and a top layer comprised of a sealable raw material. The base layer and/or the intermediate layer of the film contain a total of at least 2% by weight of titanium dioxide.
Inventors
- 👤 Detlef E. Schuhmann
- 👤 Herbert Peiffer
- 👤 Ursula Murschall
- 👤 Gunter Schloegl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:06
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/18; B32B27/20; B32B27/32; B32B2250/00; B32B2250/24; B32B2250/242; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/518; B32B2307/70; B32B2307/718; B32B2307/72; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/249921; Y10T428/249953; Y10T428/249986; Y10T428/25; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
106 words
Multilayered white, biaxially-oriented polypropylene film, comprising: a base layer of propylene polymers containing up to 2% by weight of calcium carbonate of an average particle size of not more than 2.0 μm and up to 25% by weight of titanium dioxide, in each case relative to the total weight of the base layer; an intermediate layer of propylene polymers, containing up to 25% by weight of titanium dioxide relative to the weight of the intermediate layer; and a sealable top layer, wherein the overall content of titanium dioxide of the film is at least about 2% by weight, relative to the total weight of the film.
Claim 2
Dependent Claim
106 words
Multilayered white, biaxially-oriented polypropylene film, comprising: a base layer of propylene polymers containing up to 2% by weight of calcium carbonate of an average particle size of not more than 2.0 μm and up to 25% by weight of titanium dioxide, in each case relative to the total weight of the base layer; an intermediate layer of propylene polymers, containing up to 25% by weight of titanium dioxide relative to the weight of the intermediate layer; and a sealable top layer, wherein the overall content of titanium dioxide of the film is at least about 2% by weight, relative to the total weight of the film.
Claim 3
Dependent Claim
77 words
The film as claimed in claim 1, wherein the propylene polymer of the base layer and of the intermediate layer of the film, respectively, is selected from the group consisting of isotactic homopolymers and copolymers of propylene with ethylene or alpha-olefins having 4 to 8 carbon atoms and a mixture of polymers selected from the group consisting of propylene homopolymers, propylene copolymers and other polyolefins, the mixture comprising at least about 50% by weight of propylene homopolymer.
Claim 4
Dependent Claim
32 words
The film as claimed in claim 1, wherein the calcium carbonate is contained in an amount of not more than about 1.5% by weight, relative to the weight of the base layer.
Claim 5
Dependent Claim
21 words
The film as claimed in claim 1, wherein the mean particle size of the calcium carbonate particles is about 2 μm.
Claim 6
Dependent Claim
31 words
The film as claimed in claim 1, wherein the titanium dioxide contained in the base layer has an average particle size in the range of about 0.10 μm to 0.30 μm.
Claim 7
Dependent Claim
16 words
The film as claimed in claim 1, having a whiteness number of at least about 80.
Claim 8
Dependent Claim
140 words
The film as claimed in claim 1, wherein the sealable top layer comprises a sealable raw material selected from the group consisting of an ethylene homopolymer; and copolymer comprising propylene as the main component and ethylene, the ethylene content being about 4 to 10% by weight, relative to the total weight of the copolymer; a copolymer comprising propylene as the main component and butene-(1), the butene content preferably being about 10 to 15% by weight, relative to the total weight of the copolymer; a terpolymer comprising propylene, ethylene and an alpha-olefin having 4 to 10 carbon atoms, the terpolymer comprising about 93.2 to 99.0% by weight of propylene, 0.5 to 1.9% by weight of ethylene and 0.5 to 4.9% by weight of an alpha-olefin having 4 to 10 carbon atoms; and a mixture comprising two or more of these polymers.
Claim 9
Dependent Claim
12 words
The film as claimed in claim 1, comprising a second top layer.
Claim 10
Dependent Claim
21 words
The film as claimed in claim 8, comprising a further intermediate layer between the second top layer and the base layer.
Claim 11
Dependent Claim
59 words
The film as claimed in claim 1, wherein lubricant for improving the slip properties of the film is additionally contained in the top layer, the lubricant being a polydialkyl siloxane having 1 to 4 carbon atoms in the alkyl group, and wherein the top layer contains about 0.1 to 1% by weight, of an organic or inorganic antiblocking agent.
Claim 12
Dependent Claim
31 words
The film as claimed in claim 1, wherein the calcium carbonate is contained in an amount of about 0.3 to 1.0% by weight, relative to the weight of the base layer.
Claim 13
Dependent Claim
24 words
The film as claimed in claim 1, wherein the mean particle size of the calcium carbonate particles is between about 0.9 and 1.5 μm.
Claim 14
Dependent Claim
25 words
The film as claimed in claim 10, wherein the top layer contains about 0.2 to 0.5% by weight of the organic or inorganic antiblocking agent.
Claim 15
Dependent Claim
32 words
The film as claimed in claim 1, wherein the overall content of titanium dioxide of the film is about 4 to 25% by weight, relative to the total weight of the film.
Claim 16
Dependent Claim
29 words
The film as claimed in claim 1, wherein the titanium dioxide particles are coated with at least one of an organic coating and a coating of an inorganic oxide.
Claim 17
Dependent Claim
19 words
The film as claimed in claim 1, wherein at least about 95% of the titanium dioxide particles are rutile.
Claim 18
Dependent Claim
35 words
A multilayered, white, biaxially-oriented polypropylene film which comprises at least three layers and has a Berger whiteness of more than about 80 and a density of about 0.90 g/cm 3 to 0.92 g/cm 3 .
Claim 19
Dependent Claim
35 words
A multilayered, white, biaxially-oriented polypropylene film which comprises at least three layers and has a Berger whiteness of more than about 80 and a density of about 0.90 g/cm 3 to 0.92 g/cm 3 .
Claim 20
Dependent Claim
20 words
A multilayered, white, biaxially-oriented polypropylene film as claimed in claim 17, having a Berger whiteness of more than about 90.
Claim 21
Dependent Claim
11 words
A packaging material comprising a film as claimed in claim 1.
Claim 22
Dependent Claim
11 words
A packaging material comprising a film as claimed in claim 17.
Claim 23
Dependent Claim
38 words
The film as claimed in claim 1, having a total thickness of about 25 to 120 μm, an intermediate layer thickness of about 0.3 to 5 μm and a top layer thickness of about 0.1 to 5 μm.
Claim 24
Dependent Claim
38 words
The film as claimed in claim 21, having a total thickness of about 30 to 60 μm, an intermediate layer thickness of about 0.5 to 3 μm and a top layer thickness of about 0.6 to 2 μm.
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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) | 1997-01-10 | 1997-07-12 | 1998-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-10 | 2001-07-12 | 2002-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-10 | 2005-07-12 | 2006-01-11 | $7700.00 | Window Closed / Lapsed |