Synthesis of Copper Pyrithione From Zinc Pyrithione and Copper Compound

Abstract

A composition containing unique particles of copper pyrithione wherein greater than 20 wt % to 90 wt % of the particles have a particle size of greater than 10 microns, as determined by laser light scattering using a particle size distribution analyzer, and wherein the particles are flat acicular needle-shaped is described herein. Also described herein is an antifouling paint containing the copper pyrithione and a method of making the composition and antifouling paint.

1 . A composition containing particles of copper pyrithione
 wherein from greater than 20 wt % to 90 wt % of the copper pyrithione particles have a particle size of greater than 10 microns determined by laser light scattering using a particle size distribution analyzer, and wherein the particles of copper pyrithione are flat acicular needle-shaped.   
     
     
         2 . The composition of  claim 1  wherein from 25 wt % to 70 wt % of the particles have a particle size of greater than 10 microns. 
     
     
         3 . The composition of  claim 1  wherein from 30 wt % to 60 wt % of the particles have a particle size of greater than 10 microns. 
     
     
         4 . The composition of  claim 1  further comprising a polymer selected from the group consisting of silyl acrylates, metal acrylates, polyvinyl chloride, copolymers of vinyl chloride, vinyl acetate, copolymers of vinyl acetate, acrylic copolymers, epoxy, alkyd, polyvinyl alcohol, cellulose ethers, acid functional acrylates, chitosan, polyvinyl ethers and combinations thereof or a non-polymer selected from the group consisting of rosin, rosin derivatives, and combinations thereof. 
     
     
         5 . The composition of  claim 4  wherein the polymer is silyl acrylate. 
     
     
         6 . The composition of  claim 5  wherein the silyl acrylate has a number average molecular weight of between about 2000 to about 6000. 
     
     
         7 . The composition of  claim 6  further comprising zinc hydroxide. 
     
     
         8 . An antifouling coating composition comprising copper pyrithione particles and a silyl acrylate polymer, wherein from 20 wt % to 90 wt % of the copper pyrithione particles have a size of greater than 10 microns determined by laser light scattering using a particle size distribution analyzer, and wherein the copper pyrithione particles are flat acicular needle-shaped. 
     
     
         9 . The antifouling coating composition of  claim 8  further comprising a water soluble or slightly water soluble resin, wherein said resin is present in an amount of from about 4 to about 15% based on the total weight of the coating composition. 
     
     
         10 . The antifouling coating composition of  claim 9  wherein the resin is selected from the group consisting of rosin, polyvinyl ether, chitosan, and combinations thereof. 
     
     
         11 . The antifouling composition of  claim 8  further comprising an additive selected from the group consisting of copper metals, copper oxide, copper thiocyanate, zinc oxide, zinc borate, barium metaborate, triphenyl boron pyridine, triphenyl boron octidecyl amine, tralopyril, chlorfenapyr, tolyfluanid, dichlofluanid, zinc pyrithione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-methylthis-4-tert-butyl amino-6-cyclopropyam ino-s-triazine, zineb, ziram, polycarbamate, maneb, chlorothalonil, and combinations thereof. 
     
     
         12 . The antifouling composition of  claim 8  further comprising zinc hydroxide. 
     
     
         13 .- 19 . (canceled) 
     
     
         20 . The composition of  claim 1  wherein the copper pyrithione particles are obtained by reacting zinc pyrithione with a copper salt in the presence of a non-reactive polymer or non-polymer binder. 
     
     
         21 . The antifouling coating composition of  claim 8  wherein the copper pyrithione particles are obtained by reacting zinc pyrithione with a copper salt in the presence of a non-reactive polymer or non-polymer binder.