EP0263698A1
Expired / Lapsed
EP
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Heat-sealable polypropylene film
Assignee: Akzo Nobel Films Holding Ltd
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Filing: 1987-10-07
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Granted: —
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Expires: 2007-10-07
Abstract
Abstract The invention is concerned with a heat-sealable polypropylene film which has improved absorption properties for ultra-violet light and which, when viewed, is opaque white on one surface and pearlescent on the other surface. The film comprises a base polypropylene film which incorporates 1% to 30% by weight of a particulate material (size 0.2 to 25 microns), such as calcium carbonate, and which has been stretched to form voids substantially at the location of each particle. A layer of a transparent heat-sealable polymeric composition is applied to each side of the base film and in one layer there is dispersed 2.5% to 35% by weight of finely divided titanium dioxide. The sealing properties of the layer containing the titanium dioxide are substantially unchanged by the addition.
Inventors
- 👤 Gary Dennis King
- 👤 Mark John Staton
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 22:50
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/20; B32B27/205; B32B27/06; B32B27/08; B32B27/32; B32B2250/00; B32B2250/24; B32B2250/242; B32B2264/00; B32B2264/10; B32B2264/102; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/40; B32B2307/409; B32B2307/41; B32B2307/412; B32B2307/50; B32B2307/56; B32B2323/00; B32B2323/10; B32B2553/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
112 words
A heat-sealable wrapping film comprising a base polypropylene film containing in dispersion from 1% to 30% by weight of a solid particulate material having a particle size in the range of 0.2 to 25 microns which had been oriented under stretch-orientatable conditions so as to form voids in the film, the base film having one one surface a first layer of a transparent heat-sealable polymeric composition and on the other surface a second layer of a heat-sealable polymeric composition containing in dispersion from 2.5% to 35% by weight of finely divided titanium dioxide, the second layer having a thickness of from 2% to 20% of the total thickness of the wrapping film.
Claim 2
Dependent Claim
112 words
A heat-sealable wrapping film comprising a base polypropylene film containing in dispersion from 1% to 30% by weight of a solid particulate material having a particle size in the range of 0.2 to 25 microns which had been oriented under stretch-orientatable conditions so as to form voids in the film, the base film having one one surface a first layer of a transparent heat-sealable polymeric composition and on the other surface a second layer of a heat-sealable polymeric composition containing in dispersion from 2.5% to 35% by weight of finely divided titanium dioxide, the second layer having a thickness of from 2% to 20% of the total thickness of the wrapping film.
Claim 3
Dependent Claim
26 words
A film as claimed in claim 1 in which the weight of titanium dioxide in the heat-sealable polymeric composition is from 10% to 30% by weight.
Claim 4
Dependent Claim
31 words
A film as claimed in claim 1 or claim 2 in which the thickness of the second layer is from 4% to 15% of the total thickness of the wrapping film.
Claim 5
Dependent Claim
29 words
A film as claimed in claim 1, claim 2 or claim 3 in which the solid particulate material has a particle size in the range 1 to 10 microns.
Claim 6
Dependent Claim
28 words
A film as claimed in any one of the preceding claims in which the content of the particulate material within the base film is from 3% to 20%.
Claim 7
Dependent Claim
26 words
A film as claimed in any one of the preceding claims in which the particulate material is calcium carbonate, silicon, clay or a synthetic plastic material.
Claim 8
Dependent Claim
27 words
A film as claimed in any one of the preceding claims in which the heat-sealable polymeric composition is a propylene/ethylene copolymer containing a minor amount of ethylene.
Claim 9
Dependent Claim
28 words
A film as claimed in any one of the claims 1 to 6 in which the heat-sealable polymeric composition is a propylene/butene-1 copolymer, or an ethylene/propylene butene-1 terpolymer.
Claim 10
Independent Claim
121 words
A method of manufacture of a heat-sealable wrapping film comprising applying to one surface of a base polypropylene film a first layer of a transparent heat-sealable polymeric composition and to the other surface a second layer of a heat-sealable polymeric composition containing a dispersion from 2.5% to 35% by weight of finely divided titanium dioxide, the second layer having a thickness of from 2% to 20 % of the total thickness of the wrapping film and the base polypropylene film containing a dispersion from 1% to 30% by weight of a solid particulate material having a particle size in the range from 0.2 to 25 microns which is stretched under stretch-orientatable conditions before or after the application of the heat-sealable layers.
Claim 11
Independent Claim
121 words
A method of manufacture of a heat-sealable wrapping film comprising applying to one surface of a base polypropylene film a first layer of a transparent heat-sealable polymeric composition and to the other surface a second layer of a heat-sealable polymeric composition containing a dispersion from 2.5% to 35% by weight of finely divided titanium dioxide, the second layer having a thickness of from 2% to 20 % of the total thickness of the wrapping film and the base polypropylene film containing a dispersion from 1% to 30% by weight of a solid particulate material having a particle size in the range from 0.2 to 25 microns which is stretched under stretch-orientatable conditions before or after the application of the heat-sealable layers.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 9 in which the first layer and second layers of the heat-sealable composition are coextruded with the base polypropylene film.
References Cited (Backward Citations)
GB2086342A
Cited
EP0143567A2
Cited
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