EP0258020A2
Expired / Lapsed
EP
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Improved opaque film composition
Assignee: Mobil Oil AS
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Filing: 1987-08-24
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Granted: —
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Expires: 2007-08-24
Abstract
Abstract An opaque, biaxially oriented film structure is described which comprises: an expanded thermoplastic polymer matrix core layer within which is located a minor amount of a light-absorbing pigment and a strata of voids; positioned at least substantially within at least a substantial number of said voids is at least one void-initiating particle which is phase distinct and incompatible with the 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 voids in said core and the thickness of said core being such as to cause a degree of opacity of less than 15% light transmission; and at least one void-free thermoplastic skin layer affixed to a surface of the core layer, said skin layer(s) being of a thickness such that the outer surfaces thereof do not, at least substantially, manifest the surface irregularities of said core layer.
Inventors
- 👤 Charles Ray Ashcraft
- 👤 Hee Chung Park
- 👤 Joseph James Spitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 08:31
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/20; B32B27/205; B32B27/06; B32B27/08; B32B27/32; B32B2264/00; B32B2264/02; B32B2264/0214; B32B2264/0278; B32B2264/0285; B32B2307/00; B32B2307/40; B32B2307/41; B32B2307/50; B32B2307/514; B32B2307/518; B32B2323/00; B32B2323/10; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/249921; Y10T428/249953; Y10T428/249971; Y10T428/249978; Y10T428/249986; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
108 words
An opaque, biaxially-oriented, polymeric film structure which comprises: (a) a voided core layer comprising a matrix of (i) a thermoplastic polymeric material in which are dispersed (ii) void-initiating solid particles which are phase-distinct from the thermoplastic polymeric material of the matrix and about which particles are located opacifying voids and a minor amount (iii) of a light absorbing pigment; and (b) at least one transparent skin layer adhering to the surface of the voided core layer comprising a thermoplastic polymeric material and being thick enough substantially to prevent the asperities of the core layer from being manifest, the light transmission of the structure being less than about 15%.
Claim 2
Dependent Claim
108 words
An opaque, biaxially-oriented, polymeric film structure which comprises: (a) a voided core layer comprising a matrix of (i) a thermoplastic polymeric material in which are dispersed (ii) void-initiating solid particles which are phase-distinct from the thermoplastic polymeric material of the matrix and about which particles are located opacifying voids and a minor amount (iii) of a light absorbing pigment; and (b) at least one transparent skin layer adhering to the surface of the voided core layer comprising a thermoplastic polymeric material and being thick enough substantially to prevent the asperities of the core layer from being manifest, the light transmission of the structure being less than about 15%.
Claim 3
Dependent Claim
19 words
A film structure according to claim 1 wherein the thermoplastic polymeric material (i) of the matrix comprises a polyolefin.
Claim 4
Dependent Claim
12 words
A film structure according to claim 2 wherein the polyolefin comprises polypropylene.
Claim 5
Dependent Claim
20 words
A film structure according to any preceding claim wherein the void-initiating solid particles (ii) comprise an organic or inorganic material.
Claim 6
Dependent Claim
14 words
A film structure according to claim 4 wherein the material comprises a polymeric material.
Claim 7
Dependent Claim
15 words
A film structure according to claim 5 wherein the organic polymeric material comprises a polyester.
Claim 8
Dependent Claim
13 words
A film structure according to claim 6 wherein the polyester comprises polybutylene terephthalate.
Claim 9
Dependent Claim
17 words
A film structure according to any preceding claim wherein the void-initiating solid particles (ii) are substantially spherical.
Claim 10
Dependent Claim
24 words
A film structure according to any preceding claim wherein the void-initiating solid particles (ii) have an average particle size from 0.5 to 10 micrometres.
Claim 11
Dependent Claim
24 words
A film structure according to any preceding claim wherein the light absorbing pigment (iii) is a black, blue, brown, green or red coloured pigent.
Claim 12
Dependent Claim
14 words
A film structure according to claim 10 wherein the pigment is a brown pigment.
Claim 13
Dependent Claim
27 words
A film structure according to any preceding claim wherein the light absorbing pigment (iii) has an average particle size insufficient to cause voiding of the core layer.
Claim 14
Dependent Claim
21 words
A film structure according to any preceding claim wherein the light absorbing pigment (iii) is present in the core layer only.
Claim 15
Dependent Claim
28 words
A film structure according to any preceding claim wherein the light absorbing pigment (iii) is present in an amount from 2 to 12 wt. % of the core.
Claim 16
Dependent Claim
26 words
A film structure according to any preceding claim wherein at least one skin layer (b) comprises the same polymeric material as the voided core layer (a).
Claim 17
Dependent Claim
28 words
A film structure according to any preceding claim wherein the thickness of the voided core layer (a) comprises from 30 to 85% of the thickness of the structure.
Claim 18
Dependent Claim
96 words
A process for the preparation of a film structure according to any preceding claim, which process comprises: mixing a major proportion of (i) with a minor proportion of (ii); heating the mixture to a temperature above the melting point of (i); uniformly dispersing (ii) throughout (i); uniformly dispersing a minor amount of (iii) therein; and forming a biaxially-oriented core layer (a) having adhering to at least one surface of (a) a transparent skin layer (b), the biaxial orientation having been effected at a temperature and deformation ratio effective to form opacifying voids in the core layer.
Claim 19
Dependent Claim
13 words
A process according to claim 17 wherein (i) and (ii) are melted together.
Claim 20
Dependent Claim
19 words
A process according to claim 17 or 18 wherein the forming step is effected by lamination or by coextrusion.
Claim 21
Dependent Claim
23 words
A process according to any of claims 17 to 19 wherein the biaxial orientation is effected after the adhesion of (b) and (a).
Claim 22
Dependent Claim
19 words
A process according to any of claims 17 to 20 wherein the orientation in both directions is effected concurrently.
Claim 23
Dependent Claim
20 words
A process according to any of claims 17 to 21 wherein the orientation is effected at a temperature above 100°C.
Claim 24
Dependent Claim
19 words
A modified film structure according to any of claims 1 to 14 wherein the skin layer (b) is absent.
Claim 25
Dependent Claim
29 words
A modified film structure according to any of claims 1 to 15 wherein the skin layer (b) does not prevent the asperities of the core layer from being manifest.
References Cited (Backward Citations)
No citation records indexed.
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