US4698261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyolefin film having improved mechanical properties
Assignee: Hoechst AG
•
Filing: 1985-10-21
•
Granted: 1987-10-06
•
Expires: 2005-10-21
Abstract
Abstract An opaque polyolefin film having a three-layer support film and transparent or clear polyolefin covering layers which cover the two surfaces of the support film. In the support film, either the inner layer or the two intermediate layers arranged between the inner layer and the covering layers are composed of a filler-free polyolefin which is modified with a natural or synthetic resin having a softening point ranging from 70° C. to 180° C. The respective non-modified polyolefin layer or layers of the support film have a filler and exhibit a vacuole structure which produces a relatively low density film of less than 0.9 g/cm 3 . The production of the opaque polyolefin film comprising five layers is carried out by coextrusion and biaxial stretching, followed by heat setting the coextruded film. The film is advantageously used for packaging purposes.
Inventors
- 👤 Lothar Bothe
- 👤 Guenther Crass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:28
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B27/18; B32B27/20; B32B2264/00; B32B2264/10; B32B2307/00; B32B2307/40; B32B2307/41; B32B2323/00; B32B2323/10; B32B2553/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/26; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/2839; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
125 words
An opaque polyolefin film, comprising: a multilayer polyolefin support film; and two transparent or clear polyolefin covering layers, one of said covering layers covering each side of said support film; said support film including an inner layer, and two separate intermediate layers, one intermediate layer covering each side of said inner layer, wherein at least one of said layers of said support film contains a filler in an amount sufficient to impart a pearlescent luster to said polyolefin film when said polyolefin film is biaxially oriented, and wherein at least one other layer of said support film comprises a polyolefin modified with one of a natural and a synthetic resin, said resin having a softening point range from about 70° C. to about 180° C.
Claim 2
Dependent Claim
125 words
An opaque polyolefin film, comprising: a multilayer polyolefin support film; and two transparent or clear polyolefin covering layers, one of said covering layers covering each side of said support film; said support film including an inner layer, and two separate intermediate layers, one intermediate layer covering each side of said inner layer, wherein at least one of said layers of said support film contains a filler in an amount sufficient to impart a pearlescent luster to said polyolefin film when said polyolefin film is biaxially oriented, and wherein at least one other layer of said support film comprises a polyolefin modified with one of a natural and a synthetic resin, said resin having a softening point range from about 70° C. to about 180° C.
Claim 3
Dependent Claim
78 words
A polyolefin film as claimed in claim 1, wherein said inner layer contains said resin in an amount of from about 1% to about 30% by weight of the polyolefin in said inner layer, and wherein said intermediate layers each contain said filler in an amount of from about 3% to about 30% by weight of the polyolefin in each said intermediate layer, said filler having a particle size of from about 0.1 μm to about 20 μm.
Claim 4
Dependent Claim
78 words
A polyolefin film as claimed in claim 1, wherein said inner layer contains said filler in an amount of from about 3% to about 30% by weight of the polyolefin in said inner layer, said filler having a particle size of from about 0.1 μm to about 20 μm, and wherein said intermediate layers each contain said resin in an amount of from about 1% to about 30% by weight of the polyolefin in each said intermediate layer.
Claim 5
Dependent Claim
43 words
A polyolefin film as claimed in claim 1, wherein the polyolefin of said support film and said covering layers is selected from the group consisting of an alpha-olefin homopolymer and a copolymer of alpha-olefin, the alpha-olefin having from 2 to 8 carbon atoms.
Claim 6
Dependent Claim
61 words
A polyolefin film as claimed in claim 1, wherein the polyolefin of said support film comprises a propylene homopolymer, and the polyolefin of said covering layers comprises a propylene copolymer having a comonomer selected from the group consisting of ethylene, butene-1, and mixtures thereof, said comonomer being present in a quantity of up to about 20% by weight of said copolymer.
Claim 7
Dependent Claim
52 words
A polyolefin film as claimed in claim 1, wherein said resin is selected from the group consisting of a styrene polymer, an alpha-methylstyrene/styrene copolymer, an alpha-methylstyrene/vinyltoluene copolymer, a hydrogenated alpha-methylstyrene/vinyltoluene/indene copolymer, a pentadiene polymer, a hydrogenated cyclopentadiene polymer, an alpha-pinene polymer, a betapinene polymer, a terpene polymer, colophony and a modified colophony.
Claim 8
Dependent Claim
27 words
A polyolefin film as claimed in claim 1, wherein said filler is selected from the group consisting of barium sulfate, calcium carbonate, silicon dioxide and titanium dioxide.
Claim 9
Dependent Claim
83 words
A polyolefin film as claimed in claim 1, wherein said polyolefin film has a thickness of from about 10 to about 80 μm, the thickness of said inner layer being from about 30 to about 60% of the total thickness, the sum of the thicknesses of the two intermediate layers being from about 30 to about 60% of the total thickness, and the sum of the thicknesses of the two covering layers being from about 2 to about 10% of the total thickness.
Claim 10
Dependent Claim
23 words
A polyolefin film as claimed in claim 1, wherein said polyolefin film has a density of less than about 0.7 g/cm 3 .
Claim 11
Dependent Claim
17 words
A polyolefin film as claimed in claim 1, wherein said covering layers each include an antiblocking agent.
Claim 12
Dependent Claim
29 words
A polyolefin film as claimed in claim 1, wherein one of said covering layers includes an adhesive agent, and the other of said covering layers includes a releasing agent.
Claim 13
Dependent Claim
12 words
A paper substitute comprising the polyolefin film as claimed in claim 1.
Claim 14
Dependent Claim
16 words
A base film for an adhesive tape comprising the polyolefin film as claimed in claim 1.
Claim 15
Dependent Claim
122 words
An opaque polyolefin film, comprising: a multilayer polyolefin support film; and two transparent or clear polyolefin covering layers, one of said covering layers covering each side of said support film; said support film including an inner layer and two separate intermediate layers, one intermediate layer covering each side of said inner layer; wherein either said inner layer or said intermediate layers contains a filler in an amount sufficient to impart a pearlescent luster to said polyolefin film when said polyolefin film is biaxially oriented; and wherein said inner layer or said intermediate layers not containing said filler comprises a polyolefin modified with either a natural or a synthetic resin having a softening point of from about 70° C. to about 180° C.
Claim 16
Dependent Claim
122 words
An opaque polyolefin film, comprising: a multilayer polyolefin support film; and two transparent or clear polyolefin covering layers, one of said covering layers covering each side of said support film; said support film including an inner layer and two separate intermediate layers, one intermediate layer covering each side of said inner layer; wherein either said inner layer or said intermediate layers contains a filler in an amount sufficient to impart a pearlescent luster to said polyolefin film when said polyolefin film is biaxially oriented; and wherein said inner layer or said intermediate layers not containing said filler comprises a polyolefin modified with either a natural or a synthetic resin having a softening point of from about 70° C. to about 180° C.
References Cited (Backward Citations)
US4239822A
Cited
US4303708A
Cited
EP0079520A2
Cited
US4377616A
Cited
US4526823A
Cited
FR2521532A1
Cited
US4522887A
Cited
US4608284A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |