US5178942A
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US
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Multi-layer opaque film structures tailored to end-use requirements
Assignee: Mobil Oil AS
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Filing: 1991-09-09
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Granted: 1993-01-12
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Expires: 2011-09-09
Abstract
Abstract An opaque, biaxially oriented polymeric film structure, produced by orienting the film to a degree which provides low light transmission and improved machinability. The film structure includes a thermoplastic polymer matrix core layer having a first surface and a second surface, within which is located a strata of voids; positioned at least substantially within a substantial number of the voids is at least one spherical void-initiating particle which is phase distinct and incompatible with the matrix material, the void space occupied by the particle being substantially less than the volume of the void; the population of the voids in the core being such as to cause a significant degree of opacity, the core layer including a light absorbing pigment of lamellar morphology; a first non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, the second surface of the first intermediate layer adhering to the first surface of the core layer; and a second non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, the second surface of the second intermediate layer adhering to the second surface of the core layer; wherein the level of light transmission of the film is less than 10% and the degree of orientation is about 8 TDO by less than about 5 MDO.
Inventors
- 👤 Jean-Pierre Frognet
- 👤 Lajos E. Keller
- 👤 Maurice Petitjean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:14
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/20; B32B27/06; B32B27/08; B32B27/12; B32B27/32; B32B27/36; B32B7/00; B32B7/04; B32B7/12; B32B2250/00; B32B2250/24; B32B2262/00; B32B2262/02; B32B2262/0276; B32B2262/0284; B32B2307/00; B32B2307/40; B32B2307/41; B32B2307/50; B32B2307/514; B32B2307/518; B32B2323/00; B32B2323/10; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249971; Y10T428/249978; Y10T428/24998; Y10T428/249986; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
233 words
An opaque, biaxially oriented polymer film structure, produced by orienting the film to a degree which provides low light transmission and improved machinability, comprising: (a) a thermoplastic polymer matrix core layer having a first surface and a second surface, within which is located a strata of voids; positioned at least substantially within a substantial number of said voids is at least one spherical void-initiating particle which is phase distinct and incompatible with said matrix material, the void space occupied by said particle being substantially less than the volume of said void, with one generally cross-sectional dimension of said particle at least approximating a corresponding cross-sectional dimension of said void; the population of said voids in said core being such as to cause a significant degree of opacity, said core layer including a light absorbing pigment of lamellar morphology; (b) a first non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, said second surface of said first intermediate layer adhering to said first surface of said core layer; and (c) a second non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, said second surface of said second intermediate layer adhering to said second surface of said core layer; herein the level of light transmission of the film is less than 10% and the degree of orientation is about 8 TDO by less than about 5 MDO.
Claim 2
Dependent Claim
233 words
An opaque, biaxially oriented polymer film structure, produced by orienting the film to a degree which provides low light transmission and improved machinability, comprising: (a) a thermoplastic polymer matrix core layer having a first surface and a second surface, within which is located a strata of voids; positioned at least substantially within a substantial number of said voids is at least one spherical void-initiating particle which is phase distinct and incompatible with said matrix material, the void space occupied by said particle being substantially less than the volume of said void, with one generally cross-sectional dimension of said particle at least approximating a corresponding cross-sectional dimension of said void; the population of said voids in said core being such as to cause a significant degree of opacity, said core layer including a light absorbing pigment of lamellar morphology; (b) a first non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, said second surface of said first intermediate layer adhering to said first surface of said core layer; and (c) a second non-voided thermoplastic polymer intermediate layer having a first surface and a second surface, said second surface of said second intermediate layer adhering to said second surface of said core layer; herein the level of light transmission of the film is less than 10% and the degree of orientation is about 8 TDO by less than about 5 MDO.
Claim 3
Dependent Claim
43 words
The film structure of claim 1, further comprising: (d) a first non-voided thermoplastic skin layer adhering to said first surface of said first intermediate layer; and (e) a second non-voided thermoplastic skin layer adhering to said first surface of said second intermediate layer.
Claim 4
Dependent Claim
14 words
The film structure of claim 2, wherein said void-free skin contains an antiblocking agent.
Claim 5
Dependent Claim
15 words
The film structure of claim 1, wherein said core layer is fabricated from isotactic polypropylene.
Claim 6
Dependent Claim
17 words
The film structure of claim 4, wherein the void-initiating particles of said core layer comprise polybutylene terephthalate.
Claim 7
Dependent Claim
15 words
The film structure of claim 1, wherein said intermediate layers are fabricated from isotactic polypropylene.
Claim 8
Dependent Claim
15 words
The film structure of claim 2, wherein said skin layers are fabricated from isotactic polypropylene.
Claim 9
Dependent Claim
27 words
The film structure of claim 1, wherein at least one of said intermediate layers contain from about 2% to about 6% by weight of TiO 2 .
Claim 10
Dependent Claim
17 words
The film structure of claim 2, wherein said skin layers are fabricated from a heat sealable material.
Claim 11
Dependent Claim
63 words
The film structure of claim 2, wherein said skin layers are fabricated from a material selected from the group consisting of homopolymer of propylene, linear low density polyethylene, high density polyethylene, random copolymer of propylene and ethylene, block copolymer of propylene and ethylene, copolymer of propylene and butylene, terpolymer of ethylene, propylene and butene, terpolymer of ethylene, propylene and butylene, and mixtures thereof.
Claim 12
Dependent Claim
18 words
The film structure of claim 2 wherein said skin layers are fabricated from an ethylene, 1-butene, propylene terpolymer.
Claim 13
Dependent Claim
275 words
A process for preparing an opaque, biaxially oriented polymeric film structure of low light transmission and improved machinability, comprising the steps of: (a) mixing a major proportion of a first thermoplastic polymeric material with a minor proportion of a first material of higher melting point or having a higher glass transition temperature than the first thermoplastic polymeric material to produce a core layer mixture and a minor amount of a light absorbing pigment of lamellar morphology; (b) heating the core layer mixture produced in step (a) to a temperature of at least above the melting point of the first thermoplastic polymeric material; (c) dispersing the first material of higher melting point or higher glass transition temperature of the mixture produced in step (a) uniformly throughout the molten first thermoplastic polymeric material in the form of microspheres; (d) mixing a second thermoplastic polymeric material to produce a first intermediate layer mixture; (e) heating the intermediate layer mixture produced in step (d) to a temperature of about the melting point of the second thermoplastic polymeric material; (f) mixing a third thermoplastic polymeric material to produce a second intermediate layer mixture; (g) heating the second intermediate layer mixture produced in step (f) to a temperature of about the melting point of the second thermoplastic polymeric material; and (h) forming a biaxially oriented coextruded film structure from the core layer mixture, the first intermediate layer mixture and the second intermediate layer mixture, said forming step conducted at a temperature and to a degree to form a strata of opacifying voids within the core layer; wherein the degree of orientation is about 8 TDO by less than about 5 MDO.
Claim 14
Dependent Claim
275 words
A process for preparing an opaque, biaxially oriented polymeric film structure of low light transmission and improved machinability, comprising the steps of: (a) mixing a major proportion of a first thermoplastic polymeric material with a minor proportion of a first material of higher melting point or having a higher glass transition temperature than the first thermoplastic polymeric material to produce a core layer mixture and a minor amount of a light absorbing pigment of lamellar morphology; (b) heating the core layer mixture produced in step (a) to a temperature of at least above the melting point of the first thermoplastic polymeric material; (c) dispersing the first material of higher melting point or higher glass transition temperature of the mixture produced in step (a) uniformly throughout the molten first thermoplastic polymeric material in the form of microspheres; (d) mixing a second thermoplastic polymeric material to produce a first intermediate layer mixture; (e) heating the intermediate layer mixture produced in step (d) to a temperature of about the melting point of the second thermoplastic polymeric material; (f) mixing a third thermoplastic polymeric material to produce a second intermediate layer mixture; (g) heating the second intermediate layer mixture produced in step (f) to a temperature of about the melting point of the second thermoplastic polymeric material; and (h) forming a biaxially oriented coextruded film structure from the core layer mixture, the first intermediate layer mixture and the second intermediate layer mixture, said forming step conducted at a temperature and to a degree to form a strata of opacifying voids within the core layer; wherein the degree of orientation is about 8 TDO by less than about 5 MDO.
Claim 15
Dependent Claim
35 words
The process of claim 12, wherein prior to conducting said forming step, at least one thermoplastic skin layer mixture is produced for forming at least a first skin layer to encapsulate said first intermediate layer.
Claim 16
Dependent Claim
26 words
The process of claim 13, wherein a second thermoplastic skin layer mixture is produced for forming a second skin layer to encapsulate said second intermediate layer.
Claim 17
Dependent Claim
14 words
The process of claim 14, wherein said skin layer mixtures contains an antiblocking agent.
Claim 18
Dependent Claim
13 words
The process of claim 12, wherein said core layer mixture includes isotactic polypropylene.
Claim 19
Dependent Claim
16 words
The process of claim 16, wherein the void-initiating particles of said core layer comprise polybutylene terephthalate.
Claim 20
Dependent Claim
13 words
The process of claim 12, wherein said intermediate layer mixtures include isotactic polypropylene.
Claim 21
Dependent Claim
13 words
The process of claim 14, wherein said skin layer mixtures include isotactic polypropylene.
Claim 22
Dependent Claim
23 words
The process of claim 19, wherein said intermediate layer mixtures include from about 2 to about 6% by weight of TiO 2 .
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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) | 1996-01-12 | 1996-07-13 | 1997-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-12 | 2000-07-13 | 2001-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-12 | 2004-07-13 | 2005-01-12 | $7700.00 | Window Closed / Lapsed |