Johns Manville

Amoco Corporation

Cyprus Mines Corporation

Richard Seyb Lamar

Kenneth E Weber

Norman Bach Scheffel

Yew C Chang

William E Pratt

Robert E Roeder

George Richard Bell

A method of and substances for reducing pitch in pulping and papermaking operations, particularly in furnishes made by mechanical pulping processes containing wood pulp in amounts greater than about 10% by weight, are disclosed. The method comprises adding to a pitch-containing furnish a stable, water dispersible particulate composite substance prepared by irreversibly adsorbing a water soluble cationic polymer, e.g., a poly(diallyldimethylammonium chloride), onto an essentially water insoluble particulate substrate, e.g., kaolin, thereby rendering the cationic polymer insoluble and immobile, the cationic polymer being sufficiently electropositive so that the particulate composite pitch control substance exhibits a zeta potential of at least about +30 mV, and preferably from about +60 mV to about +80 mV, the amount of the composite substance added to the furnish being effective to finely disperse pitch for removal as finely-dispersed pitch-containing aggregates in a paper sheet produced from said furnish. Further improvements in pitch control can be achieved using these particulate composite pitch control substances together with alum and/or relatively high molecular weight alkylene oxide polymers, and other desirable effects, including improved fines retention, better drainage and lower waste treatment costs are also obtained when practicing this method.

Method of reducing pitch in pulping and papermaking operations

A color developing composition for pressure-sensitive recording systems comprising an admixture of an alkylidenediphenol and calcium carbonate having a weight ratio of about 2 parts to about 20 parts phenol per 100 parts calcium carbonate. The admixture is formulated in high solids content coating colors having excellent rheological property and stabilty, which are used to produce CF sheets having a coating weight of about 4 to about 10 g/m.sub.2. Preferably, the composition comprises Bisphenol A in an amount of 4 to 10 parts per 100 parts calcium carbonate and the calcium carbonate weight % in the CF coating is greater than 50%. Other embodiments comprise an aqueous dispersion of the admixture, a pressure-sensitive recording manifold and methods of making the dispersion.

Color developing composition for carbonless paper copying system

In the manufacture of wood pulp for use in making paper and other wood fiber products, it is first necessary to remove the bark from the logs. While this can be done using a dry process, a wet process offers many advantages. However, one big disadvantage of the wet process has been the inability to economically remove the bark fines from the water used in the wet process. The present invention provides an economical manner of solving this problem by using a rotary vacuum precoat filter equipped with a rotating knife to remove the bark fines from at least a portion of the recirculating water in a wet debarking process and to avoid long range problems with such a process by adding a small amount of finely divided talc to the bark fines suspension prior to filtration.

Removing of bark fines from aqueous suspensions

Milled talc materials containing about twenty to about thirty-five weight percent tremolite having particle size distributions such that no more than five percent of the particles are larger than 10 microns, no more than 12 percent of the particles are larger than five microns and no more than 15 percent of the particles are smaller than 0.3 microns in equivalent spherical diameter have improved opacifying properties for use in paper, rubber, plastics and paint manufacture. The materials can be obtained by jet or fluid energy milling and by controlling the milling variables to produce particle size distributions within the critical range.

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Littleton, CO, United States of America

Richard Seyb Lamar