Mitsubishi Paper Mills Limited

Toru Katsura

Hiroo Kaji

Kenji Hyodo

Hideaki Senoh

Massashi Kubbota

Hirokazu Ohkura

An alkaline paper is produced by adding a cationic starch containing an alkyltetrahydro-1,3,5-2H-thiadiazine-2-thione or a bromonitroalcohol, and an alkylketene dimer to a paper stock. Formation of slime in the paper stock system is substantially inhibited and an alkaline paper excellent in sizing characteristics and safety to man is obtained.

Process for producing alkaline paper

A photographic support consisting essentially of base paper and a polyolefin resin with which both sides of the base paper are coated, the base paper having a standard deviation of the weight variation caused by a wire mark formed on the base paper of 1.0 g/m.sup.2 or less and a standard deviation of the weight variation caused by the dispersibility of pulp fiber composing the base paper of 8.0 g/m.sup.2 or less. The photographic support has an excellent smoothness.

Photograhic paper support

Heat sensitive recording paper having such a thickness distribution that the average amplitude of paper thickness variation, between 0.2-mm and 1.0-mm wavelengths of paper thickness variation, does not exceed 0.5 .mu.m and no distinctive variation peak is present in the above wavelength range.

Heat sensitive recording paper

A photographic paper support comprising a base paper coated on both sides with a polyolefin resin is markedly improved in resistance to the stain occurring around the edges after development processing (edge stain), by the inclusion of an anionic polyacrylamide and a cationic starch in said base paper.

Polyolefin coated photographic paper support

A photographic paper comprising a web and a photographic emulsion coated on the web wherein the web contains at least one member selected from the group consisting of weak acid salts of magnesium, calcium and zinc and oxides of magnesium, calcium and zinc as a photographic-properties improving agent in an amount of 0.01% by weight or more based on the weight of the pulp in the web is remarkably effective on reducing unfavorable influence on photographic properties caused by chemical additives in the web. Such an effect is particularly remarkable when the web contains at least one cationic additive such as cationic sizing agent, cationic strength agent, etc.

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Tokyo, Japan

Toru Katsura