Powder detergent granule containing acidic water-soluble polymer and manufacturing method thereof

Abstract

The present invention relates to powder detergent granules that are substantially free of a water-insoluble component such as zeolite or silica, a method for manufacturing the powder detergent granules and a copolymer having various properties useful as a detergent component. The powder detergent granules of the present invention are substantially free of a water-insoluble component, and thus exhibit good solubility and washing performance (stain removal performance) in cold water, do not leave residue after laundry, and reduce the likelihood of a caking phenomenon during manufacture and storage. And, the powder detergent granules of the present invention are substantially free of zeolite or silica that absorbs a liquid component, but are capable of accommodating a considerable amount of liquid surfactant. Further, a copolymer comprising acrylic acid monomer unit and 2-acrylamido-2-methylpropane sulfonic acid monomer unit, an acidic water-soluble polymer of the present invention, is useful as a detergent component in various aspects.

1 . A method for manufacturing detergent granules, comprising:
 providing an acidic water soluble polymer, an alkali builder, and a surfactant; and   mixing 0.1 to 15 parts by weight of the acidic water-soluble polymer, 10 to 70 parts by weight of the alkali builder, and 1 to 60 parts by weight of the surfactant to form the detergent granules,   wherein the mixing effects a neutralization reaction between the acidic water-soluble polymer and the alkali builder, and   wherein the neutralization reaction generates heat for naturally drying the detergent granules, eliminating the need for a separate heating step.   
     
     
         2 . The method of  claim 1 , wherein the neutralization reaction further generates gas for creating pores in the detergent granules. 
     
     
         3 . The method of  claim 2 , further comprising controlling an apparent density of the detergent granules by controlling the pores. 
     
     
         4 . The method of  claim 1 , wherein an apparent density of the detergent granules is less than 0.6 g/ml. 
     
     
         5 . The method of  claim 1 , further comprising providing the acidic water soluble polymer by providing a homopolymer or copolymer comprising at least one monomer unit selected from the group consisting of a monomer unit containing a carboxylic acid group, a monomer unit containing a sulfonic acid group and a monomer unit containing a phosphoric acid group. 
     
     
         6 . The method of  claim 5 , wherein the monomer unit comprises at least two acid groups selected from the group consisting of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group. 
     
     
         7 . The method of  claim 1 , wherein the mixing is performed without adding a substantial amount of solvent. 
     
     
         8 . The method of  claim 1 , further comprising providing the acidic water soluble polymer by providing a copolymer comprising a monomer unit containing a carboxylic acid group and a monomer unit containing a sulfonic acid group, wherein a ratio of the carboxylic acid group to the sulfonic acid group is 95:5 to 80:20. 
     
     
         9 . The method of  claim 1 , wherein the acidic water soluble polymer has an average molecular weight of about 3,000 to about 60,000. 
     
     
         10 . The method of  claim 1 , further comprising providing the acidic water soluble polymer by providing a copolymer comprising an acrylic acid monomer unit and a 2-acrylamido-2-methylpropane sulfonic acid monomer unit as shown by the following structure: 
       
         
           
           
               
               
           
         
       
     
     
         11 . The method of  claim 7 , wherein the solvent is water. 
     
     
         12 . The method of  claim 1 , wherein the alkali builder comprises at least one of sodium carbonate, sodium bicarbonate, sodium sulfate and sodium hydroxide. 
     
     
         13 . The method of  claim 1 , further comprising providing an organic acid and mixing 1 to 30 parts by weight of the organic acid with the acidic water soluble polymer, the alkali builder, and the surfactant, to form the detergent granules, wherein the organic acid acts as an acid component together with the acidic water soluble polymer in the neutralization reaction. 
     
     
         14 . The method of  claim 13 , wherein the organic acid is a solid phase organic acid comprising at least one of a derivative of a carboxylic acid, a succinic acid, a tartaric acid, and a malic acid. 
     
     
         15 . The method of  claim 1 , wherein the surfactant comprises at least one of 1 to 30 parts by weight of an anionic surfactant and 1 to 30 parts by weight of a nonionic surfactant. 
     
     
         16 . The method of  claim 15 , wherein the anionic surfactant comprises at least one of lauryl benzene sulfonic acid, alpha-olefin sulfonate, sodium lauryl sulfate and sodium lauryl ethoxylated sulfate. 
     
     
         17 . The method of  claim 15 , wherein the anionic surfactant acts as an acid component together with the acidic water soluble polymer in the neutralization reaction. 
     
     
         18 . The method of  claim 15 , wherein the nonionic surfactant comprises at least one of polyoxyethylene alkyl ether, coconut diethanolamide, fatty acid alkanolamine, amine oxide, alkyl polyglucoside, methyl polyethylene alkyl ether and sugar ether. 
     
     
         19 . The method of  claim 15 , wherein the nonionic surfactant is liquid, and comprises 5 weight % or more of the detergent granules. 
     
     
         20 . The method of  claim 1 , wherein a solvent content of the detergent granules is 5 weight % or less based on the total amount of the acidic water-soluble polymer, the alkali builder, and the surfactant.