Absorbent mass of alloy fibers of regenerated cellulose and polyacrylic acid salt of alkali-metals or ammonium

Abstract

A mass of alloy fibers of polyacrylic acid salt of alkali-metals or ammonium and regenerated cellulose, useful for absorbing fluids, are prepared by mixing a caustic solution of polyacrylic acid with viscose, spinning the mixture into fibers and obtaining dry fibers in the alkaline state. The fibers are advantageously dried with an alkaline lubricating finish thereon and then processed into dressings, sanitary napkins, tampons and diapers.

I claim: 
     
       1. An article of manufacture comprising a highly fluid absorbent mass of.Iadd.dry alkaline.Iaddend.alloy fibers.[.said alloy fibers.]. comprising a matrix of regenerated cellulose and polyacrylic acid salt of alkali-metals .[.or ammonium uniformly.]. dispersed therein,.Iadd. said salt being present in an amount ranging from about 5 to about 35 percent, based on the weight of the cellulose.Iaddend.. .[.2. The article of claim 1 wherein the polyacrylic acid salt of alkali-metals or ammonium is present in the regenerated cellulose in an amount ranging from about 5 to 
     
     
        about 35 percent, based on the weight of the cellulose..]. .[.3.  The article of claim 1 wherein the fibers have a lubricating finish for 
     
     
        cellulose thereon..]. 4.  The article of claim 1 in the form of a pad. 5. The article of claim 1 in the form of a tampon. .Iadd. thereon, 6. An article as in claim 3 wherein said lubricating finish comprises a partial higher fatty acid ester of sorbitan or mannitan or of a polyoxyethylene derivative thereof. .Iaddend..Iadd. 7. An article as in claim 3 wherein said fibers are carded staple fibers, said article comprising a compressed mass of said staple fibers. .Iaddend. .Iadd. 8. An article as in claim 6, said salt being such, and present in such proportion, that the "fluid holding capacity" is at least 4.55 cc./g., said fluid holding capacity being measured by taking two grams of said fiber in staple form, carded or well opened, placing said two grams of fiber in a 1 inch diameter die, pressing the fibers in the die to 0.127 inch thickness for one minute, removing the resulting pressed test pellet, placing said pellet on a Buchner funnel with a 1 inch diameter foot of a vertically movable plunger weighing 2.4 pounds resting on said pellet, immersing said so-placed pellet in water for two minutes and then draining the water for three minutes, removing the resulting wet pellet and weighing it to determine the amount of water held thereby. .Iaddend. .Iadd. 9. An article as in claim 1 produced by a method comprising mixing a polyacrylic acid salt of alkali-metals with a filament-forming viscose whereby the viscose predominates in the mixture, forming the mixture into fibers, coagulating and regenerating the fibers, applying a lubricating finish for cellulose to said fibers, and drying the fibers in an alkaline state with said polyacrylic acid salt in said fiber in the form of a sodium salt, said method including the step of cutting the fibers into staple form before drying, the proportion of said polyacrylic acid salt added to said viscose ranging from about 5 to about 35 percent, based on the weight of the cellulose, said lubricating finish comprising a partial higher fatty acid ester of sorbitan or mannitan or of a polyoxyethylene derivative thereof, said sodium salt in said dried alkaline fibers being such, and present in such proportion, that the "fluid holding capacity" is at least 4.55 cc./g., said fluid holding capacity being measured by taking two grams of said fiber in staple form, carded or well opened, placing said two grams of fiber in a 1 inch diameter die, pressing the fibers in the die to 0.127 inch thickness for one minute, removing the resulting pressed test pellet, placing said pellet on a Buchner funnel with a 1 inch diameter foot of a vertically movable plunger weighing 2.4 pounds resting on said pellet, immersing said so-placed pellet in water for two minutes and then draining the water for three minutes; removing the resulting wet pellet and weighing it to determine the amount of water held thereby. .Iaddend. .Iadd. 10. An article as in claim 8 in which said salt is a sodium salt. .Iaddend. .Iadd. 11. A dry alkaline alloy fiber comprising a matrix of regenerated cellulose and polyacrylic acid salt of alkali-metals, said fiber having a lubricating finish for cellulose thereon, said salt being such, and present in such proportion, within the range of about 5 to about 35 percent based on the weight of cellulose, that the "fluid holding capacity" is at least 4.55 cc./g., said fluid holding capacity being measured by taking two grams of said fiber in staple form, carded or well opened, placing said two grams of fiber in a 1 inch diameter die, pressing the fibers in the die to 0.127 inch thickness for one minute, removing the resulting pressed test pellet, placing said pellet on a Buchner funnel with a 1 inch diameter foot of a vertically movable plunger weighing 2.4 pounds resting on said pellet, immersing said so-placed pellet in water for two minutes and then draining the water for three minutes, removing the resulting wet pellet and weighing it to determine the amount of water held thereby. .Iaddend. .Iadd. 12. Fiber as in claim 11, said fiber being in staple form and said alkali metal being sodium and said salt being present in amount of at least 10% based on weight of cellulose. .Iaddend. .Iadd. 13. Fiber produced by a method comprising mixing a polyacrylic acid salt of alkali-metals with a filament-forming viscose whereby the viscose predominates in the mixture, forming the mixture into fibers, coagulating and regenerating the fibers, applying a lubricating finish for cellulose to said fibers, and drying the fibers in an alkaline state with said polyacrylic acid salt in said fiber in the form of a sodium salt, said method including the step of cutting the fibers into staple form before drying, the proportion of said polyacrylic acid salt added to said viscose ranging from about 5 to about 35 percent, based on the weight of the cellulose, said sodium salt in said dried alkaline fibers being such, and present in such proportion, that the "fluid holding capacity" is at least 4.55 cc./g., said fluid holding capacity being measured by taking two grams of said fiber in staple form, carded or well opened, placing said two grams of fiber in a 1 inch diameter die, pressing the fibers in the die to 0.127 inch thickness for one minute, removing the resulting pressed test pellet, placing said pellet on a Buchner funnel with a 1 inch diameter foot of a vertically movable plunger weighing 2.4 pounds resting on said pellet, immersing said so-placed pellet in water for two minutes and then draining the water for three minutes, removing the resulting wet pellet and weighing it to determine the amount of water held thereby. .Iaddend.