Low-substituted hydroxypropyl cellulose and process for producing same

Abstract

The present invention provides a low-substituted hydroxypropyl cellulose having a loose bulk density of not less than 0.40 g/mL and a tap bulk density of not less than 0.60 g/mL and a process for producing the same.

What is claimed is:  
     
         1 . A low-substituted hydroxypropyl cellulose having a loose bulk density of not less than 0.40 g/mL and a tap bulk density of not less than 0.60 g/mL.  
     
     
         2 . A low-substituted hydroxypropyl cellulose as claimed in  claim 1  which has a degree of compaction of not greater than 35%.  
     
     
         3 . A low-substituted hydroxypropyl cellulose as claimed in  claim 1  which has a flowability index of not less than 60.  
     
     
         4 . A low-substituted hydroxypropyl cellulose as claimed in  claim 1  which has an angle of repose of not greater than 40 degrees.  
     
     
         5 . A process for producing a low-substituted hydroxypropyl cellulose which comprises the steps of dipping pulp in an alkaline solution to prepare alkali cellulose, reacting the alkali cellulose with propylene oxide, dissolving the resulting product partially in water or an alkaline solvent, precipitating the product by neutralization with an acid, and washing, drying and grinding the precipitated product, wherein the product is completely dissolved prior to the neutralization with an acid.  
     
     
         6 . A process for producing a low-substituted hydroxypropyl cellulose as claimed in  claim 5  wherein the alkaline solution used for the preparation of alkali cellulose comprises an aqueous solution of sodium hydroxide having a concentration of not greater than 45% by weight.