An ascorbic acid dispersion material, and its manufacturing method

Abstract

To provide an ascorbic acid dispersion material with higher chemical stability, and with superior usage characteristics, such as spreadability and smoothness, upon application onto skin. The ascorbic acid dispersion material is obtained by dispersing ascorbic acid crystals in a solvent, whereby the ascorbic acid crystals have a flat plate shape, a thickness of 0.05 to 3 μm, and an average particle diameter of 50 to 100 μm.

1 . An ascorbic acid dispersion material, which is obtained by dispersing an ascorbic acid crystal in a solvent,
 wherein the ascorbic acid crystal has a flat plate shape, a thickness of 0.05 to 3 μm, and an average particle diameter of 50 to 100 μm.   
     
     
         2 . The ascorbic acid dispersion material according to  claim 1 , wherein the particle size distribution of the ascorbic acid crystal has a distribution such that particles having a particle diameter of 30 to 120 μm account for 40 to 80% of the overall particles. 
     
     
         3 . The ascorbic acid dispersion material according to  claim 1 , wherein the solvent is one or more selected from a group consisting of glycerin, diglycerin, polyglycerin represented by the following formula, and propylene glycol. 
       
         
           
           
               
               
           
         
       
     
     
         4 . The ascorbic acid dispersion material according to  claim 1 , wherein the ascorbic acid concentration is 20 to 40 wt %. 
     
     
         5 . The ascorbic acid dispersion material according to  claim 1 , wherein the average density is 1.3 to 1.4 g/cm 3 . 
     
     
         6 . The ascorbic acid dispersion material according to  claim 1 , wherein the viscosity is 5000 to 300,000 mPa·s. 
     
     
         7 . A manufacturing method of the ascorbic acid dispersion material according to  claim 1 , comprising:
 a heating step involving infusing an ascorbic acid into a solvent comprising one or more selected from a group consisting of glycerin, diglycerin, polyglycerin represented by the following formula, and propylene glycol, and heating the ascorbic acid to a predetermined temperature to dissolve the ascorbic acid;   a cooling step involving cooling the solution with the ascorbic acid dissolved therein at a cooling rate of 5 to 20° C./min until the temperature of the solution reaches 35 to 50° C. to remove heat from the solution; and   a growth step involving storing the solution after completion of the cooling step at 27 to 38° C. for a predetermined period to promote crystal growth.   
       
         
           
           
               
               
           
         
       
     
     
         8 . A skin care preparation, which contains an ascorbic acid dispersion material according to  claim 1 .