Encapsulated biocides and biorepellents

Abstract

The present invention relates to silica aerogels with a high to very high loading (60-90% w/w) of encapsulated biocidal and/or biorepellant compounds and to methods of making and using such aerogels in anti-fouling compositions, which are especially suitable for marine use.

1 . Antifouling additive comprising
 a. an inorganic, silica-containing aerogel comprising   b. a porous gel lattice, and   c. optionally an alcoxide comprising Sc, Ti, V, Cr, Mn, Fe, Co, Y, Zr, Nb, Ru, Hf, Ta, W, Re, Al, Ge, In, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, and   d. one or more biocidal or biorepellant compounds entrapped in said aerogel,   wherein said silica-containing aerogel comprises at least 60% by weight of the one or more biocidal or biorepellant compounds, and wherein the entrapment of said one or more biocidal or biorepellant compounds takes place during the SOL-GEL formation of the gel, and wherein the bulk density of said aerogel has a value of at most 0.5 gr/ml when said aerogel comprises at most 75% by weight Zn pyrithione.   
     
     
         2 . Antifouling additive according to  claim 1  comprising at least 75% by weight of the one or more biocidal or biorepellant compounds. 
     
     
         3 . Antifouling additive according to  claim 1  wherein the biocidal or biorepellant compound is a member selected from the group consisting of pyrithione compounds, basic copper carbonate, isothiazolinone compounds, substituted triazines, carbamates, chlorinated aromatic ureas, triazoles and combinations thereof. 
     
     
         4 . Antifouling additive according to  claim 1 , wherein the biocidal or biorepellant compound is Zinc pyrithione, Copper pyrithione, Copper thiocyanate, Tolyolfluanid, Dichlorfluanid, DCOIT/Sea-Nine, Zineb={Zn[S2CN(H)CH2CH2N(H)CS2]} n =Zinc ethylenebisthiocarbamate and Econea®=2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethyl pyrrole (Tralopyril). 
     
     
         5 . Antifouling additive according to  claim 1 , wherein the biocidal or biorepellant compound is selected from Copper pyrithione or Zinc Pyrithione. 
     
     
         6 - 12 . (canceled) 
     
     
         13 . A marine paint comprising an antifouling additive according to  claim 1 . 
     
     
         14 . Antifouling paint composition comprising an antifouling additive according to  claim 1 . 
     
     
         15 . Antifouling paint composition according to  claim 14  comprising an inorganic, silica-containing aerogel comprising
 a. a porous gel lattice, and 
 b. optionally an alcoxide comprising Sc, Ti, V, Cr, Mn, Fe, Co, Y, Zr, Nb, Ru, Hf, Ta, W, Re, Al, Ge, In, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, and 
 c. at least 6% by weight of one or more biocidal or biorepellant compounds selected from the group consisting of Zinc pyrithione, Copper pyrithione, Copper thiocyanate, Tolyolfluanid, Dichlorfluanid, DCOIT/Sea-Nine, Zineb={Zn[S2CN(H)CH2CH2N(H)CS2]}n=Zinc ethylenebisthiocarbamate and Econea®=2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethyl pyrrole (Tralopyril). entrapped in said aerogel.