Small Enzyme-Containing Granules

Abstract

The invention provides small enzyme-containing granules having an inorganic salt core and an enzyme-containing layer coated over the core, and methods for producing such granules. The majority of the enzyme granules are less than 300 μm in diameter. The granules are suitable for incorporation into compositions such as cleaning, textile processing, and animal feed compositions.

We claim: 
     
         1 . A population of enzyme-containing granules, wherein at least about 95% of said granules comprise a single core and an enzyme-containing layer coated over said core,
 wherein said core consists of one or more inorganic salts,   and wherein at least about 80% of said granules comprise a diameter of about 150 to about 355 microns.   
     
     
         2 . A population of granules according to  claim 1 , wherein said core consists of sodium sulfate. 
     
     
         3 . A population of granules according to  claim 2 , wherein at least about 80% of said sodium sulfate cores comprise a diameter of about 100 to about 250 microns. 
     
     
         4 . A population of granules according to  claim 1 , wherein the enzyme-containing layer further comprises at least one of a polymer, a sugar, a starch, or a surfactant. 
     
     
         5 . A population of granules according to  claim 1 , further comprising a layer comprising a barrier salt coated over said enzyme-containing layer. 
     
     
         6 . A population of granules according to  claim 5 , wherein the barrier salt layer comprises sodium sulfate. 
     
     
         7 . A population of granules according to  claim 5 , wherein the barrier salt layer comprises a mixture of two or more salts. 
     
     
         8 . A population of granules according to  claim 7 , wherein said mixture of two or more salts consists of sodium sulfate and magnesium sulfate. 
     
     
         9 . A population of granules according to  claim 8 , wherein said sodium sulfate and magnesium sulfate are present in said barrier salt layer at a ratio of about 30:70 to about 70:30 by weight of the barrier layer. 
     
     
         10 . A population of granules according to  claim 5 , further comprising an outer coating layer comprising a polymer coated over said barrier salt layer. 
     
     
         11 . A population of granules according to  claim 10 , wherein said polymer is a polyvinyl alcohol. 
     
     
         12 . A population of granules according to  claim 5 , further comprising an outer coating layer comprising a pigment coated over said barrier salt later. 
     
     
         13 . A population of granules according to  claim 10 , wherein said outer coating layer further comprises a pigment. 
     
     
         14 . A population of granules according to  claim 1 , wherein said core comprises a bulk density greater than about 1.2 g/ml. 
     
     
         15 . A detergent comprising a population of granules according to  claim 1 . 
     
     
         16 . A textile processing composition comprising a population of granules according to  claim 1 . 
     
     
         17 . An animal feed composition comprising a population of granules according to  claim 1 . 
     
     
         18 . A method of making enzyme-containing granules, comprising coating an enzyme-containing layer onto cores in a fluidized bed spray coater,
 wherein at least about 95% of said granules comprise a single core,   wherein said cores consist of one or more inorganic salts,   wherein said cores are pre-sieved to a particle dispersity index of about 2.0 or less,   and wherein at least about 80% of said granules comprise a diameter of about 150 to about 355 microns.   
     
     
         19 . A method according to  claim 18 , wherein said cores consist of sodium sulfate. 
     
     
         20 . A method according to  claim 19 , wherein at least about 80% of said sodium sulfate cores comprise a diameter of about 100 microns to about 250 microns. 
     
     
         21 . A method according to  claim 20 , wherein said sodium sulfate cores comprise a bulk density greater than about 1.2 g/ml. 
     
     
         22 . A method according to  claim 18 , further comprising coating a layer comprising a barrier salt over said enzyine-containing layer,
 wherein the granules are not removed from the fluidized bed spray coater prior to addition of the barrier salt layer.   
     
     
         23 . A method according to  claim 22 , wherein said barrier salt layer comprises sodium sulfate. 
     
     
         24 . A method according to  claim 22 , wherein the barrier salt layer comprises a mixture of two or more salts. 
     
     
         25 . A method according to  claim 24 , wherein said mixture of two or more salts consists of sodium sulfate and magnesium sulfate. 
     
     
         26 . A method according to  claim 25 , wherein said sodium sulfate and magnesium sulfate are present in said barrier salt layer at a ratio of about 30:70 to about 70:30 by weight of the barrier layer. 
     
     
         27 . A method according to  claim 22 , further comprising coating an outer coating layer comprising a polymer over said barrier salt layer,
 wherein the granules are not removed from the fluidized bed spray coater prior to addition of the outer coating layer.   
     
     
         28 . A method according to  claim 27 , wherein said polymer is a polyvinyl alcohol. 
     
     
         29 . A method according to  claim 22 , further comprising coating an outer coating layer comprising a pigment over said barrier salt later,
 wherein the granules are not removed from the fluidized bed spray coater prior to addition of the outer coating layer.   
     
     
         30 . A method according to  claim 27 , wherein said outer coating layer further comprises a pigment.