초록 ▼

The present invention is directed to a process for preparing cellulose containing water sorptive products from an aqueous suspension or paper furnish in accordance with conventional paper making techniques. The suspension or paper furnish employed in preparing the sorptive products comprises a polym

The present invention is directed to a process for preparing cellulose containing water sorptive products from an aqueous suspension or paper furnish in accordance with conventional paper making techniques. The suspension or paper furnish employed in preparing the sorptive products comprises a polymer component and a fibrous component slurried in water. The polymer component is provided from a specifically defined class of crosslinked copolymers which contain carboxyl groups. A representative polymer from this class includes that obtained by reacting methyl acrylate and methacrylate acid in the presence of ethylene glycol dimethacrylate. The polymer component becomes water sorptive when the carboxyl groups present thereon are neutralized with a base. In the practice of the process of the present invention, a composite product is prepared from the above mentioned suspension, partially dried, and then neutralized in a specifically controlled manner. Neutralization is achieved while controlling the amount of base and water which contacts the composite product. The control is exercised in a manner sufficient to achieve a proper degree of salting and to prevent undue sorption of the water during neutralization. Such control results in a substantial improvement in the cost efficiency of the process since the amount of water which must be eventually evaporated from the neutralized product is held to a minimum.

대표청구항 ▼

A process for preparing a water sorptive product which comprises: (1) forming an aqueous suspension comprising a slurry of a potentially water swellable, water-insoluble polymer component and a fibrous component in water wherein the polymer component comprises the reaction product of: (a) from about

A process for preparing a water sorptive product which comprises: (1) forming an aqueous suspension comprising a slurry of a potentially water swellable, water-insoluble polymer component and a fibrous component in water wherein the polymer component comprises the reaction product of: (a) from about 15% to about 50% by weight of an olefinically-unsaturated carboxylic!acid; (b) from about 49.07% to about 82% by weight of an alkyl acrylate wherein the alkyl group has from 1 to 6 carbon atoms; and (c) from about 0.03% to about 3.0% by weight of a crosslinking agent, said reaction product having carboxyl groups present therein which when coverted to their salt form maintains the polymer water-insoluble and imparts the capability of said polymer component of sorbing water upon contact therewith; and wherein the fibrous component comprises at least 50% cellulose material, and the weight ratio of said polymer component to said fibrous component is controlled to from about 90:10 to about 5:95; (2) forming a composite product from said suspension; (3) partially drying said composite product to reduce the moisture content thereof to between about 3 and about 25%, by weight, based on the weight thereof; (4) contacting said partially dried composite product with an amount of an aqueous solution of a base sufficient to achieve a degree of salting of the polymer component of said composite product of from about 100 to about 120% and thereby netralize the carboxylic groups present thereon and in a manner sufficient to prevent the weight ratio of the dry neutralized composite product to water sorbed therein from exceeding 1:10 without solubilizing the polymer salt; and (5) drying said neutralized composite product to reduce the moisture content thereof to not greater than about 25% by weight.