Reduction of optical brightener migration in polyolefin coated paper bases

DETAILED DESCRIPTION What is claimed is: 1.
In the method of making a light-sensitive photographic paper comprising the steps of coating a paper support with a polyolefin polymer containing an optical brightening agent, rolling the polyolefin coated support and storing the paper roll, unrolling the stored support, corona discharge treating the polyolefin surface and applying at least one light sensitive emulsion on the polyolefin surface, the improvement which comprises after coating the polyolefin layer on the paper support and prior to the rolling step subjecting the polyolefin surface to a corona discharge to inhibit the optical brightening agent from exuding from the polyolefin layer.
2.
The method of claim 1 wherein the polyolefin polymer is polyethylene.
3.
The method of claim 1 wherein the polyolefin polymer contains a white pigment.
4.
The method of claim 3 wherein the white pigment is titanium dioxide.




Description:
BACKGROUND OF THE INVENTION 1.
Field of the Invention This invention relates to photographic supports and elements, and more particularly, to photographic supports and elements comprising a paper base material having thereon a polyolefin coating containing a white pigment and an optical brightener.
2.
Background of the Invention A valuable class of photographic supports and elements comprises a paper base material having thereon a polyolefin coating containing a white pigment and an optical brightener.
Such supports are particularly useful in the preparation of photographic elements such as color prints because they exhibit good brightness and excellent dimensional stability and are highly resistant to the action of aqueous acid and alkaline photographic processing solutions.
The polyolefin coating provides a very smooth surface which is desirable when thin layers, such as silver halide emulsion layers, are to be coated thereover, U.
S.
Pat.
No.
3,411,908 describes such a support which has achieved widespread commercial acceptance.
The purpose of the optical brightener is to make the white areas of the support appear even brighter