Washing method and clothes detergent composition

Abstract

A washing method is described which has excellent washing power and a low surfactant concentration. The described clothes washing method comprises the use of a phosphorus-free clothes detergent composition comprising (a) one or more surfactants, (b) one or more alkali metal silicates, and (c) one or more metal ion capturing agents other than the alkali metal silicate (b). The above detergent composition is added to water in an amount sufficient to produce a washing liquid having the following washing conditions (1) a pH of not less than 10.60; (2) containing a material having an ion capturing capacity in an amount sufficient for theoretically changing the water hardness of said water to be not more than 0.5° DH; and (3) having a surfactant concentration of from 0.07 to 0.17 g/L.

We claim:  
     
       1. A clothes washing method which comprises: 
       (i) adding a phosphorus-free clothes detergent composition comprising (a) one or more surfactants, (b) one or more alkali metal silicates having an SiO 2 /M 2 O ratio of from 0.5 to 2.6 wherein M stands for an alkali metal, and (c) one or more metal ion capturing agents other than the alkali metal silicate (b) selected from the group consisting of carboxylate polymers; aluminosilicates; aminotri(methylenephosphonic acid); 1-hydroxyethylidene-1,1-diphosphonic acid; ethylenediaminetetra (methylenephosphonic acid); diethylenetriaminepenta (methylenephosphonic acid); and salts thereof; salts of phosphonocarboxylic acids; amino acid salts and aminopolyacetates, wherein the total amount of (a), (b), and (c) components occupies 70 to 100% by weight of the entire composition, and wherein the weight ratio of the alkali metal silicate (b) to the metal ion capturing agent other than the alkali metal silicate (c) is not more than 5/1, to washing water in an amount sufficient to produce a washing liquid having the following washing conditions:  
       (1) a pH of not less than 10.60;  
       (2) containing a material having an ion capturing capacity in an amount sufficient for theoretically changing the water hardness of said washing water to be not more than 0.5° DH; and  
       (3) having a surfactant concentration of from 0.07 to 0.17 g/L; and  
       (ii) washing clothes in said washing liquid.  
     
     
       2. The washing method according to  claim 1 , wherein the concentration of the detergent composition in the washing liquid is from 0.33 to 0.67 g/L for washing water having a water hardness of from 2 to 6° DH. 
     
     
       3. The washing method according to  claim 1 , wherein the concentration of the detergent composition in the washing liquid is from 0.50 to 1.20 g/L for washing water having a water hardness of from 6 to 10° DH. 
     
     
       4. The washing method according to  claim 1 , wherein the concentration of the detergent composition in the washing liquid is from 0.80 to 2.50 g/L for washing water having a water hardness of from 10 to 20° DH. 
     
     
       5. The washing method according to  claim 1 , wherein the total amount of (a), (b), and (c) components occupies 80 to 100% by weight of the entire composition. 
     
     
       6. A phosphorous-free clothes detergent composition comprising components (a) to (c): 
       (a) one or more surfactants;  
       (b) one or more alkali metal silicates having an SiO 2 /M 2 O ratio of from 0.5 to 2.6 wherein M stands for an alkali metal; and  
       (c) one or more metal ion capturing agents selected from the group consisting of carboxylate polymers; aluminosilicates; aminotri(methylenephosphonic acid); 1-hydroxyethylidene-1,1-diphosphonic acid; ethylenediaminetetra (methylenephosphonic acid); diethylenetriaminepenta (methylenephosphonic acid); and salts thereof; salts of phosphonocarboxylic acids; amino acid salts; and  aminopolyacetates; and polycarboxylates,  
       wherein the total amount of (a), (b), and (c) components occupies 70 to 100% by weight of the entire composition, and wherein the weight ratio of component (b) to component (a) is 9/1 to 1/2  9/11, and the weight ratio of component (b) to component (c) is 5/1 to 1/15. 
     
     
       7. The clothes detergent composition according to  claim 6 , wherein the weight ratio of component (b) to component (a) is 9/1 to 9/11, and the weight ratio of component (b) to component (c) is 4/1 to 1/15. 
     
     
       8. The clothes detergent composition according to  claim 6  or  7 , wherein the surfactant contains a nonionic surfactant in an amount of 50 to 100% by weight. 
     
     
       9. The clothes detergent composition according to  claim 8 , wherein the nonionic surfactant is a polyoxyethylene alkyl ether having an ethylene oxide moiety with an average molar number of from 5 to 15 and an alkyl moiety having an average number of carbon atoms of from 10 to 18. 
     
     
       10. The clothes detergent-composition according to  claim 6 , wherein the alkali metal silicate is contained as an alkalizer in an amount of 50 to 100% by weight of the entire alkalizer. 
     
     
       11. The clothes detergent composition according to  claim 10 , wherein the alkali metal silicate is contained as an alkalizer in an amount of 70 to 100% by weight of the entire alkalizer. 
     
     
       12. The clothes detergent composition according to  claim 6 , wherein the alkali metal silicate is crystalline. 
     
     
       13. The clothes detergent composition according to  claim 12 , wherein the crystalline alkali metal silicate is represented by the following formula (I): 
       
         
           xM 2 O·ySiO 2 ·zMe m O n ·wH 2 O,   (I)  
         
       
       wherein M represents an alkali metal; Me stands for one or more elements selected from the group consisting of Group IIa, IIb, IVa, and VIII; y/x is 0.5 to 2.6; z/x is 0.01 to 1.0; n/m is 0.5 to 2.0; and w is 0 to 20. 
     
     
       14. The clothes detergent composition according to  claim 12 , wherein the crystalline alkali metal silicate is represented by the following formula (II): 
       
         
           M 2 O·x′SiO 2 ·y′H 2 O,   (II)  
         
       
       wherein M stands for an alkali metal; x′ is 1.5 to 2.6; and y′ is 0 to 20. 
     
     
       15. The clothes detergent composition according to  claim 6 , wherein the (c) metal ion capturing agent contains a carboxylate polymer having a Ca ion capturing capacity of not less than 200 CaCO 3  mg/g in an amount of not less than 10% by weight. 
     
     
       16. The clothes detergent composition according to  claim 6 , wherein the (c) metal ion capturing agent comprises: 
       (c-i) a carboxylate polymer having a Ca ion capturing capacity of not less than 200 CaCO 3  mg/g; and  
       (C-ii) an aluminosilicate having an ion exchange capacity of not less than 200 CaCO 3  mg/g and having the following formula (III):  
       
         
           x″(M 2 O)·Al 2 O 3 ·y″(SiO 2 )·w″(H 2 O),   (III)  
         
       
       wherein M stands for an alkali metal; x″, y″, and w″ each stands for a molar number of each component; x″ is from 0.7 to 1.5; y″ is from 0.8 to 6.0; and w″ is from 0 to 20, and wherein the weight ratio of (c-i) component to (c-ii) component is (c-i)/(c-ii)=1/20 to 4/1, and the total amount of (c-i) and (c-ii) components occupies 70 to 100% by weight based on the (c) metal ion capturing agent. 
     
     
       17. A clothes washing method which comprises: 
       (i) adding a phosphorus-free clothes detergent composition comprising (a) one or more surfactants, (b) one or more alkali metal silicates having an SiO 2 /M 2 O ratio of from 0.5 to 2.6 wherein M stands for an alkali metal, and (c) one or more metal ion capturing agents selected from the group consisting of carboxylate polymers; aluminosilicates; aminotri(methylenephosphonic acid); 1-hydroxyethylidene-1,1-diphosphonic acid; ethylenediaminetetra(methylenephosphonic acid); diethylenetriaminepenta(methylenephosphonic acid); and salts thereof; salts of phosphonocarboxylic acid; amino acid_ salts and ; aminopolyacetates; and polycarboxylates, wherein the total amount of (a), (b), and (c) components occupies 70 to 100% by weight of the entire composition, and wherein the weight ratio of component (b) to component (a) is 9/1 to 1/2, and the weight ratio of component (b) to component (c) is 5/1 to 1/15, to washing water in an amount sufficient to produce a washing liquid having the following washing conditions:  
       (1) a pH of not less than 10.60;  
       (2) containing a material having an ion capturing capacity in an amount sufficient for theoretically changing the water hardness of said washing water to be not more than 0.5° DH; and  
       (3) having a surfactant concentration of from 0.07 to 0.17 g/L; and  
       (ii) washing clothes in said washing liquid.