Slow-release insect-repellent compositions and uses

Abstract

A slow-release insect repellent composition comprising an insect repellent, an oleophilic chemical soluble in the insect repellent, and a carbohydrate matrix wherein the combination of the insect repellent and oleophilic chemical is entrapped in the matrix such that the repellent is released from the matrix, a fabric substrate containing the composition and method for preparing the composition.

What is claimed is:  
     
         1 . A slow-release insect-repellent formulation for a fabric substrate, said formulation comprising an insect repellent, an oleophilic chemical soluble in said insect repellent, a carbohydrate matrix wherein the combination of said insect repellent and said oleophilic chemical is entrapped in said matrix such that said insect repellent is released from said matrix.  
     
     
         2 . The formulation of  claim 1  wherein the weight ratio of said insect repellent to said oleophilic chemical is of from about 0.13:0.2 to about 0.875:0.635 per weight of said carbohydrate matrix.  
     
     
         3 . The formulation of  claim 2  wherein said insect is repellent is encapsulated in a microcapsule with a diameter from about 0.005 mm to about 1.800 mm and wherein said insect repellent is from about 10% to about 35% of the weight of said formulation.  
     
     
         4 . The formulation of  claim 3  further comprising a fabric treatment formulation, said fabric treatment formulation comprises from about 2% to 6% (owf) cationic softener.  
     
     
         6 . The formulation of  claim 4  wherein said fabric treatment formulation is a padding formulation of from about 90% to about 98% (owf).  
     
     
         7 . The formulation of  claim 4  wherein said fabric treatment formulation is a pigment printing paste formulation of from about 90% to about 98% (owf).  
     
     
         8 . The formulation of  claim 4  wherein said fabric treatment formulation is a water repellent formulation of from about 90% to about 98% (owf).  
     
     
         9 . The formulation of  claim 4  wherein said fabric treatment formulation is a finishing rinse formulation of from about 2% to about 5% (owf).  
     
     
         10 . The formulation of  claim 4  wherein said fabric treatment formulation is an ink formulation comprising of from about 2% to about 5% (w/w) ink dispersion and from about 85% to about 96% (w/w) extender.  
     
     
         11 . The formulation of  claim 4  wherein said fabric treatment formulation comprises about 100% (w/w) extender.  
     
     
         12 . The formulation of  claim 4  wherein said insect repellent is N,N′-diethyl-m-toluamide.  
     
     
         13 . A process for the manufacture of an insect-repellent formulation comprising the steps of combining an insect repellent with an oleophilic chemical soluble in said insect repellent; slurrying said combination in a water solution comprising said carbohydrate matrix such that said combination is entrapped in said matrix and slowly released from said matrix; and spray drying said slurry to form a powder comprising microcapsules of said insect repellent.  
     
     
         14 . The process of  claim 13  wherein the weight ratio of said insect repellent to said oleophilic chemical is of from about 0.13:0.2 to about 0.875:0.635 on a weight basis with said carbohydrate matrix.  
     
     
         15 . The process of  claim 14  wherein said microcapsules are of from about 0.005 mm to about 1.800 mm in diameter and wherein said insect repellent is of from about 3% to about 8% on a weight basis with said microcapsules.  
     
     
         16 . The process of  claim 15  which further comprises the step of combining with said powder a fabric treatment formulation.  
     
     
         17 . The process of  claim 16  wherein said fabric treatment formulation comprises of from about 2% to about 6% (owf) cationic softener.  
     
     
         18 . The process of  claim 16  wherein said fabric treatment formulation is a padding formulation of from about 90% to about 98% (owf).  
     
     
         19 . The process of  claim 16  wherein said fabric treatment formulation is a pigment printing paste formulation of from about 90% to about 98% (owf).  
     
     
         20 . The process of  claim 16  wherein said fabric treatment formulation is a water repellent formulation of is from about 90% to about 98% (owf).  
     
     
         21 . The process of  claim 16  wherein said fabric treatment formulation is a finishing rinse formulation of from about 2% to about 5% (owf).  
     
     
         22 . The process of  claim 16  wherein said fabric treatment formulation is an ink formulation comprising of from about 2% to about 5% (w/w) ink dispersion and from about 85% to about 96% (w/w) extender.  
     
     
         23 . The process of  claim 16  wherein said fabric treatment formulation comprises about 100% (w/w) extender.  
     
     
         24 . The process of  claim 16  wherein said insect repellent is N,N′-diethyl-m-toluamide.  
     
     
         48 . A fabric substrate comprising the slow-release insect-repellent formulation comprising an insect repellent, an oleophilic chemical soluble in said insect repellent, and a carbohydrate matrix wherein the combination of said insect repellent and oleophilic chemical is entrapped in said matrix such that said insect repellent is released from said matrix, said fabric substrate having an insect repellency of up to twelve (12) months.  
     
     
         49 . The fabric substrate 48 wherein the weight ratio of said insect repellent to said oleophilic chemical is of from about 0.13:0.2 to about 0.875:0.635 per weight of said carbohydrate matrix.  
     
     
         50 . The fabric substrate of claim  49  wherein said insect repellent is comprised in microcapsules with a diameter of from about 0.005 mm to about 1.800 mm and wherein said insect repellent is of from about 3% to about 8% on a weight basis with said microcapsules.  
     
     
         51 . The fabric substrate of  claim 50  wherein said insect repellent is N,N′-diethyl-m-toluamide.  
     
     
         52 . A garment manufactured with the fabric substrate of claim  48 .  
     
     
         53 . The formulation of  claim 1  wherein said formulation is applied onto the fabric substrate.  
     
     
         54 . The formulation of  claim 53  wherein said formulation is contacted with insects.  
     
     
         55 . The formulation of  claim 1  wherein said fabric substrate consists of woven, nonwoven and knit substrates.  
     
     
         56 . The formulation of  claim 1  wherein said oleophilic chemical is silicone.  
     
     
         57 . The formulation of  claim 56  wherein said silicone is an elastomeric silicone.  
     
     
         58 . The formulation of  claim 56  wherein said silicone is a monomeric silicone.  
     
     
         59 . The formulation of claim wherein said silicone is from about 15% to about 25% of the formulation.  
     
     
         60 . The formulation of  claim 1  further comprising silicone.  
     
     
         61 . The process of  claim 13  wherein said oleophilic chemical is silicone.  
     
     
         62 . The process of  claim 11  further comprising the step of combining silicone with said insect repellent and said oleophilic chemical.  
     
     
         63 . The fabric substrate of claim  48  wherein said oleophilic chemical is silicone.  
     
     
         64 . The fabric substrate of  claim 63  wherein said silicone is an elastomeric silicone.  
     
     
         65 . The fabric substrate of  claim 63  wherein said silicone is a monomeric silicone.  
     
     
         66 . The fabric substrate of claim  48  wherein said formulation further comprises silicone.