Biocide-encapsulated microcapsule for use in paint

Abstract

A biocide-encapsulated microcapsule for use in paint includes a hydrophilic core formed by polymerization of a hydrophilic monomer comprising an unsaturated bond in presence of a free radical initiator; and a biocide being a hydrophobic compound. The hydrophilic core encloses the dispersed biocide to effect storage and releases of the biocide. Therefore, the biocide is released from the microcapsule core in the long term such that a resultant dried paint prevents biofouling in the long term.

What is claimed is: 
     
         1 . A biocide-encapsulated microcapsule for use in paint, comprising:
 a hydrophilic core formed by polymerization of a hydrophilic monomer comprising an unsaturated bond in presence of a free radical initiator; and   a biocide being a hydrophobic compound,   wherein the hydrophilic core encloses the dispersed biocide to effect storage and releases of the biocide.   
     
     
         2 . The biocide-encapsulated microcapsule of  claim 1 , wherein the hydrophilic monomer comprising an unsaturated bond further polymerizes in presence of a cross-linking agent having unsaturated bonds to form a cross-linking hydrophilic core. 
     
     
         3 . The biocide-encapsulated microcapsule of  claim 2 , wherein the cross-linking agent is divinylbenzene. 
     
     
         4 . The biocide-encapsulated microcapsule of  claim 1 , further comprising a cross-linking hydrophilic shell adapted to enclose the hydrophilic core and formed by polymerization of a hydrophilic monomer comprising an unsaturated bond and another cross-linking agent having unsaturated bonds. 
     
     
         5 . The biocide-encapsulated microcapsule of  claim 1 , wherein the biocide comprises at least a hydrophobic compound with water solubility of less than 2 wt %. 
     
     
         6 . The biocide-encapsulated microcapsule of  claim 1 , wherein the biocide is 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT). 
     
     
         7 . The biocide-encapsulated microcapsule of  claim 1 , wherein the free radical initiator is one selected from the group consisting of potassium persulfate, benzoyl peroxide, and azodiisobutyrodinitrile. 
     
     
         8 . The biocide-encapsulated microcapsule of  claim 1 , wherein the hydrophilic monomer comprising an unsaturated bond is one selected from the group consisting of methyl methacrylate (MMA), methyl acrylate, and acrylic acid. 
     
     
         9 . A biocide-encapsulated microcapsule for use in paint, comprising:
 a hydrophilic core formed by polymerization of a first hydrophilic monomer comprising an unsaturated bond;   a hydrophilic co-crosslinking shell adapted to enclose the hydrophilic core and formed by copolymerization of the first hydrophilic monomer and a second hydrophilic monomer comprising an unsaturated bond; and   a biocide being a hydrophobic compound,   wherein the hydrophilic core and the hydrophilic co-crosslinking shell enclose the dispersed biocide to effect storage and releases of the biocide.   
     
     
         10 . The biocide-encapsulated microcapsule of  claim 9 , wherein the biocide comprises at least a hydrophobic compound with water solubility of less than 2 wt %. 
     
     
         11 . The biocide-encapsulated microcapsule of  claim 9 , wherein the biocide is 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT).