Newpage Wisconsin System, Inc.

Stora Enso North America Corporation

Newpage Corporation

Suresh B Cherukuri

Bernard J Berger

Dean F Benjamin

A coated paper suitable for cold-set as well as heat-set printing applications and methods for producing the coated paper. In accordance with one aspect, the coated paper comprises a cellulosic substrate and a coating on at least one side of the substrate wherein the coating comprises a binder and a pigment such that the coated side exhibits surface characteristics such that the surface accepts cold-set inks.

Paper suitable for cold-set as well as heat set

A method of producing the low glare, high print gloss paper of the invention comprises the steps of providing a paper substrate, coating the substrate with an aqueous coating composition having, as a dry parts by weight per 100 parts of pigment, 50-90 parts coarse delaminated clay pigment having a particle size of 8-12 microns and 10-20 parts calcium carbonate having a particle size of between 0.7 and 1.1 microns, drying the coating; and supercalendering the coated substrate with at least two passes per side with rolls having a surface roughness of 90-130 Ra. The step of supercalendering imparts a Parker Print-Surf roughness of 1.7-2.2 microns and a sheet gloss of about 25-30. Four color printing produces a print gloss of 65-70 and a delta gloss of at least 38.

Low glare, high print gloss printing paper

An aqueous talc slurry that exhibits minimal foaming comprises talc pigment, a carboxymethyl cellulose (CMC) wetting agent having a molecular weight of between 50,000 and 150,000, an ionic polyacrylate dispersing agent, and has a solids content of between 55% and 65%. The slurry has an entrained air content of less than about 1% as measured after at least several minutes of low shear agitation. A method of preparing a talc slurry that exhibits minimal foaming comprises the sequential steps of mixing CMC wetting agent with water, adding an ionic polyacrylate dispersing agent, and dispersing talc to result in a solids content of between 55% and 65%. The resultant slurry has an entrained air content of less than 1% as measured after at least 30 minutes of low shear mixing. An aqueous talc slurry containing a small amount of xanthan gum stabilizing agent is stable for prolonged periods.

Growing community of inventors

Wisconsin Rapids, WI, United States of America

Suresh B Cherukuri