Halftone image production

Claim 2

A process for the production of a halftone pattern on a paper base support coated with a polyolefin layer, characterized in that the halftone pattern is produced on a said support whereof the polyolefin layer has a coverage in the range of 5 to 40 g/m2 and is coated for carrying the halftone pattern with a binder layer containing a hydrophilic colloid binding agent and white titanium dioxide pigment particles having an average grain size in the range of 200 nm to 450 nm and being present in a weight percent of at most 300 % with respect to the total binder content, the titanium dioxide being applied at a coverage of at least 0.5 g per m2.

Claim 3

A process for the production of a halftone pattern on a paper base support according to claim 1, wherein the halftone pattern is a halftone multicolour colloid pattern, the process comprising the following steps : (1) transferring a substantially non-hardened gelatin silver halide emulsion layer containing coloured pigment particles dispersed therein from a temporary support onto a permanent support being said paper base support which support may carry already a halftone relief image containing coloured hardened gelatin, (2) imagewise exposing the non-hardened gelatin silver halide emulsion layer prior to or after carrying out said step (1), (3) forming by hardening development a halftone image in said transferred silver halide emulsion layer, and (4) wash-off processing to remove selectively unhardened portions of the transferred layer, and (5) repeating steps (1), (2) and (3) to form at least partly superposed portions of differently coloured gelatin containing layers.

Claim 4

A process according to claim 2, wherein the transferred silver halide emulsion layer before or after its transfer is exposed through a halftone selection image of a multicolour original.

Claim 5

A process according to claim 2 or 3, wherein the transferred silver halide emulsion layer after development is treated with a bleach-fixing liquid for removing image silver and residual silver halide from the emulsion layer.

Claim 6

A process according to any of claims 1 to 4, wherein the polyolefin layer includes a polymer selected from the group consisting of an ethylene homopolymer being a high density polyethylene or a low density polyethylene, a propylene homopolymer or a copolymer of ethylene containing not more than 10 % by weight of styrene, vinyl stearate, vinyl acetate, acrylic acid, ethyl acrylate, methyl methacrylate, methacrylic acid, butadiene or isoprene.

Claim 7

A process according to any of claims 1 to 5, wherein the hydrophilic colloid binding agent is gelatin.

Claim 8

A process according to any of claims 1 to 6, wherein the gelatin is used in combination with a hydrophobic polymer in latex form.

Claim 9

A process according to claim 7, wherein the gelatin and latex polymer as solids are used in a weight ratio range of 1 : 5 to 5 : 1.

Claim 10

A sheet or weblike material which consists of a paper base support coated with a polyolefin layer, characterized in that the polyolefin layer has a coverage in the range of 5 to 40 g/m2 and is coated with a binder layer containing a hydrophilic colloid binding agent and white titanium dioxide pigment particles having an average grain size in the range of 200 nm to 450 nm and being present in a weight percent of at most 300 % with respect to the total binder content, the titanium dioxide being applied at a coverage of at least 0.5 g per m2.

Claim 11

A sheet or weblike material which consists of a paper base support coated with a polyolefin layer, characterized in that the polyolefin layer has a coverage in the range of 5 to 40 g/m2 and is coated with a binder layer containing a hydrophilic colloid binding agent and white titanium dioxide pigment particles having an average grain size in the range of 200 nm to 450 nm and being present in a weight percent of at most 300 % with respect to the total binder content, the titanium dioxide being applied at a coverage of at least 0.5 g per m2.

Claim 12

A sheet or weblike material according to claim 9, wherein the polyolefin layer includes a polymer selected from the group consisting of an ethylene homopolymer being a high density polyethylene or a low density polyethylene, a propylene homopolymer or a copolymer of ethylene containing not more than 10 % by weight of styrene, vinyl stearate, vinyl acetate, acrylic acid, ethyl acrylate, methyl methacrylate, methacrylic acid, butadiene or isoprene.

Claim 13

A sheet or weblike material according to claim 9 or 10, wherein the hydrophilic colloid binding agent is gelatin.

Claim 14

A sheet or weblike material according to claim 11, wherein the gelatin is used in combination with a hydrophobic polymer in latex form.

Claim 15

A sheet or weblike material according to claim 12, wherein the gelatin and latex polymer as solids are used in a weight ratio range of 1 : 5 to 5 : 1.