Carbohydrate agent of high water retention power, process of making same, and composition containing same

Abstract

The reaction product of a carbohydrate such as a sugar, with an alkaline agent such as an alkali metal hydroxide solution has a high water retention power which is about as high as that of the neutral skin sugar fraction obtained by extraction of the stratum corneum and far superior to that of hygroscopic compounds such as glycerol, glycols, the water-soluble amino acid fraction of the skin and others which, although they attract water, permit rapid evaporation thereof.

We claim: 
     
       1. .[.In a.]. .Iadd.A .Iaddend.process .[.of.]. .Iadd.for .Iaddend.producing a carbohydrate mixture having a high water retention power.[., the steps which comprise.]. .Iadd.and comprising .Iaddend.adding an aqueous alkali metal hydroxide solution to an aqueous solution of a carbohydrate selected from the group consisting of glucose, lactose, and a mixture of glucose and lactose, so as to adjust the pH-value of said carbohydrate solution to a pH of about 13.0, allowing the carbohydrate to react with said alkali metal hydroxide until the pH-value of the mixture has decreased to a pH of about 9.0, again adding the alkali metal hydroxide solution to the reaction mixture to adjust the pH-value of about 13.0, allowing the reaction to proceed until the pH-value of the mixture has decreased to a pH of about 9.0, and repeating said addition of the alkali metal hydroxide solution and reaction of the carbohydrate therewith at a pH between about 13.0 and about 9.0 until no further increase in the water retention power of the mixture of reaction products is achieved, and adjusting the pH-value of the reaction mixture to a pH of about 6.0. .[.to recover the reaction product from the reaction mixture.].. 
     
     
       2. The process according to claim 1, wherein the aqueous solution of an alkali metal hydroxide is a solution containing about 10% of sodium hydroxide. 
     
     
       3. The process according to claim 1, wherein the aqueous solution of a carbohydrate is a solution containing 20% to 30% of said carbohydrate. 
     
     
       4. The process according to claim 1, wherein the reaction temperature is between about 15° C. and about 30° C. 
     
     
       5. The process according to claim 1, wherein the carbohydrate solution is an aqueous glucose solution. 
     
     
       6. The process according to claim 1, wherein the carbohydrate solution is a lactose solution. 
     
     
       7. In a process of producing an agent of high water retention power, the steps which comprise adding an aqueous solution of an alkali metal hydroxide to an aqueous solution of glucose, allowing the mixture to react at a pH between about 9.0 and about 13.0, and acidifying the resulting reaction mixture to a pH of about 6.0, the proportion of glucose to alkali metal hydroxide in the reaction solution being adjusted so as to produce fructose in the resulting reaction mixture in an amount corresponding to about 40 parts of fructose for about 60 parts of glucose. 
     
     
       8. In a process of producing an agent of high water retention power, the steps which comprise adding an aqueous solution of an alkali metal hydroxide to an aqueous solution of lactose, allowing the mixture to react at a pH between about 9.0 and about 13.0, and acidifying the resulting reaction mixture to a pH of about 6.0, the proportion of lactose to alkali metal hydroxide in the reaction solution being adjusted so as to produce products of lactose degradation and transformation in the resulting reaction mixture in an amount corresponding to about 40 to 60 parts of said lactose degradation and transformation products for about 60 to 40 parts of lactose. 
     
     
       9. A carbohydrate mixture comprising the following main ingredients in the following proportions: between about 2.0% and about 8.0% of mannose,   between about 25.0% and about 50.0% of fructose,   between about 35.0% and about 60.0% of glucose,   between about 0.5% and about 4.5% of a degradation product of lactose,   between about 1.0% and about 3.0% of galactose, and   between about 2.0% and about 8.0% of lactose, said mixture having a high water retention power.     
     
     
       10. The carbohydrate mixture according to claim 9, wherein the mixture comprises the following ingredients in the following proportions: about 0.5% of psicose,   about 3.6% of mannose,   about 37.0% of fructose,   about 53.3% of glucose,   about 1.3% of galactose,   about 0.9% of a degradation product of lactose,   about 2.5% of lactose, and less than 0.3% of glutose and an unknown product designated as U 2 .     
     
     
       11. The carbohydrate mixture according to claim 9, wherein the mixture comprises the following main ingredients in the following proportions: about 3.0% of mannose,   about 31.1% of fructose,   about 46.7% of glucose,   about 2.1% of galactose,   about 6.5% of lactose,   about 0.2% of psicose,   about 3.1% of a degradation of lactose,   about 2.2% of glutose, and   about 4.7% of an unknown product designated as U 1 . .Iadd. 12. A process for producing a carbohydrate mixture having high water-retention power and which comprises the following steps:   a. reacting an aqueous solution of at least one carbohydrate selected from the group consisting of glucose and lactose at a temperature up to about 25° C. with an aqueous alkaline agent solution in a pH range between 9.0 and 13.0 until no further increase in water-retention power of the resulting admixture of reaction products is obtained, the pH decreasing within the stated range during the resulting reaction, and   b. adjusting the pH of said resulting admixture to a pH of about 6.0. .Iaddend. .Iadd.13. A process according to claim 12 for producing a carbohydrate mixture having high water-retention power and which comprises the following steps:   a. adding an aqueous alkaline agent solution to the aqueous carbohydrate solution until the pH value of the carbohydrate solution is about 13.0,   b. allowing the carbohydrate in said solution to react until the pH value in the resulting mixture is about 9.0,   c. adding more aqueous alkaline agent solution to said resulting mixture until the pH value thereof is about 13.0,   d. allowing a reaction to proceed in the thus-obtained mixture until the pH-value of said thus-obtained mixture is about 9.0,   e. repeating steps (c) and (d) alternately until no further increase in water-retention power of the resulting admixture of reaction products is achieved, and   f. adjusting the pH-value of said resulting admixture at a pH of about 6.0. .Iaddend..Iadd. 14. A stable (glucose and/or lactose)/(aqueous alkaline agent) reaction product which is a carbohydrate mixture and which, when applied to skin,   a. causes retention of water in the horny layer of the skin to which it is applied and   b. keeps the skin to which it is applied smooth and flexible in a manner comparable with such properties of the neutral skin sugar fraction. .Iaddend..Iadd. 15. A cosmetic composition having ingredient means for normalizing the water content of the stratum corneum and carrier therefor, the composition containing an effective concentration of the ingredient means for rendering skin, to which it is applied, smooth and flexible, the ingredient means having a pH of about 6.0 having high-water-retention power and being a reaction product of glucose and/or lactose with an   
     
     
        alkaline agent. .Iaddend..Iadd. 16.  A cosmetic composition according to claim 15 which is an oil-in-water emulsion. .Iaddend..Iadd. 17. A cosmetic composition according to claim 15 which is a water-in-oil emulsion. .Iaddend..Iadd. 18. A cosmetic composition according to claim 15, from 0.1 to 5 percent by weight of which is the ingredient means. .Iaddend.