EP0444326A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Sheet or web material having antistatic properties
Assignee: Agfa Gevaert NV
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Filing: 1990-03-01
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Granted: —
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Expires: 2010-03-01
Abstract
Abstract A sheet or web material being a subbed or unsubbed hydrophobic resin support or paper support coated with at least one hydrophobic resin layer and having at least on one side thereof an antistatic layer containing for at least 70 % by weight colloidal silica having an average particle size not larger than 10 nm and a surface area of at least 300 m² per gram, the colloidal silica being present in said antistatic layer at a coverage of at least 50 mg per m², characterized in that said antistatic layer is coated with a covering layer having a smaller sticking power to a gelatin layer than said silica containing layer, said covering layer containing at least 50 % by weight of a water-insoluble synthetic polymer being applied at a dry coverage in the range of 0.01 to 2 g/m².
Inventors
- 👤 Etienne Adrianus Van Thillo
- 👤 Bavo August Muys
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 01:48
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/16; G; G03; G03C; G03C1/00; G03C1/76; G03C1/7614; G03C1/85; G03C8/00; G03C8/02; G03C8/04; G03C8/06; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/259; Y10T428/27; Y10T428/273; Y10T428/277; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
140 words
A sheet or web material being a subbed or unsubbed hydrophobic resin support or paper support coated with at least one hydrophobic resin layer and having at least on one side thereof an antistatic layer containing for at least 70 % by weight colloidal silica having an average particle size not larger than 10 nm and a surface area of at least 300 m² per gram, the colloidal silica being present in said antistatic layer at a coverage of at least 50 mg per m², characterized in that said antistatic layer is coated with a covering layer having a smaller sticking power to a gelatin layer than said silica containing layer, said covering layer containing at least 50 % by weight of a water-insoluble synthetic polymer being applied at a dry coverage in the range of 0.01 to 2 g/m².
Claim 2
Dependent Claim
27 words
A sheet or web material according to claim 1, wherein said covering layer is applied at a dry coverage in the range of 0.05 to 1 g/m².
Claim 3
Dependent Claim
33 words
A sheet or web material according to claim 1 or 2, wherein the colloidal silica has a surface area of 500 m2 per gram and an average grain size smaller than 7 nm.
Claim 4
Dependent Claim
32 words
A sheet or web material according to any of claims 1 to 3, wherein the coverage of said colloidal silica is in the range of 100 mg to 500 mg per m2.
Claim 5
Dependent Claim
34 words
A sheet or web material according to any of claims 1 to 4, wherein said antistatic layer is coated from an aqueous dispersion of the colloidal silica in the presence of a surface-active agent.
Claim 6
Dependent Claim
28 words
A sheet or web material according to any of claims 1 to 5, wherein said antistatic layer contains colloidal silica in the presence of an anionic surface-active agent.
Claim 7
Dependent Claim
28 words
A sheet or web material according to any of claims 1 to 6, wherein said antistatic layer contains colloidal silica in the presence of a non-ionic surface-active agent.
Claim 8
Dependent Claim
35 words
A sheet or web material according to any of claims 1 to 7, wherein in said antistatic layer the weight ratio of colloidal silica to surface-active agent is in the range from 5/1 to 200/1.
Claim 9
Dependent Claim
21 words
A sheet or web material according to any of claims 1 to 8, wherein said support is a polyester resin support.
Claim 10
Dependent Claim
28 words
A sheet or web material according to any of claims 1 to 9, wherein said antistatic layer contains colloidal silica in the presence of a synthetic hectorite clay.
Claim 11
Dependent Claim
37 words
A sheet or web material according to claim 10, wherein in the antistatic layer the synthetic hectorite clay is present in admixture with the colloidal silica in a weight ratio in the range of 1/20 to 1/4.
Claim 12
Dependent Claim
39 words
A sheet or web material according to any of the preceding claims, wherein said covering layer is applied from a coating composition containing at least one water-insoluble synthetic polymer dissolved in an organic solvent or mixture of organic solvents.
Claim 13
Dependent Claim
34 words
A sheet or web material according to claim 12, wherein said polymer is selected from the group consisting of polymethylmethacrylate, polyisobutylmethacrylate, polycarbonate, mixed polyester-carbonate or said covering layer is made of a polycarbonate/polystyrene blend.
Claim 14
Dependent Claim
31 words
A sheet or web material according to any of the preceding claims, wherein said covering layer is applied from an aqueous coating composition containing said water-insoluble synthetic polymer as a latex.
Claim 15
Dependent Claim
32 words
A sheet or web material according to any of the claims 1 to 14, wherein a coating composition for said covering layer contains a matting agent, coating aid and/or friction lowering substance.
Claim 16
Dependent Claim
28 words
A sheet or web material according to claim 14, wherein said latex contains colloidal silica and/or latex particles improving the adherence to a gelatin containing layer coated thereto.
Claim 17
Dependent Claim
32 words
A sheet or web material according to claim 14, wherein said latex polymer is a copolymer of vinylidene chloride with acrylic monomers and minor amounts of vinyl monomers containing carboxylic acid groups.
Claim 18
Dependent Claim
24 words
A sheet or web material according to claim 17, wherein said copolymer is a copolymer of of vinylidene chloride, methyl acrylate and itaconic acid.
Claim 19
Dependent Claim
37 words
A sheet or web material according to any of the preceding claims, wherein said material is a photographic material containing (a) silver halide emulsion layer(s) on a subbed hydrophobic resin support or hydrophobic resin coated paper support.
Claim 20
Dependent Claim
33 words
A sheet or web material according to claim 19, wherein said antistatic layer is present at the side of the hydrophobic resin support opposite the side coated with the silver halide emulsion layer(s).
Claim 21
Dependent Claim
39 words
A sheet or web material according to claim 20, wherein said covering layer is coated with a gelatin layer substantially equalizing the tension exerted on the front and rear side of the photographic material after wet processing and drying.
References Cited (Backward Citations)
EP0320692A2
Cited
EP0334400A1
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