Protracted release microbiocidal article for aqueous systems

Claim 2

An article useful for storing, handling, transporting, and providing a microbiocidal compound at a controlled rate in a method for controlling living microorganisms in an aqueous system comprising (a) a flexible, water-permeable membrane having a film thickness sufficient to maintain the integrity thereof when sealed and sufficient water vapor permeability to permit diffusion of water therethrough and containing sealed therein (b) a particulate solid microbiocidal composition useful in aqueous systems comprising: (i) about 0.1-70 weight %, based on total weight of said composition, of at least one water-soluble microbiocidal compound having a relatively low water solubility of less than about 1000 ppm or a combination thereof with one or more other microbiocidal compounds to give a combination characterized by a relatively low water solubility of less than about 1000 ppm; and (ii) about 99.9-30 weight %, based on total weight of said composition, of an inert, finely-divided water-insoluble solid carrier material.

Claim 3

An article according to claim 1 wherein the flexible, water-permeable membrane has a film thickness of about 0.5 mil to about 10 mils and has a water vapor permeability of about 0.2-40 g. per ml. in 24 hrs. for a 100 in. 2 film.

Claim 4

An article according to claim 2 wherein said flexible, water-permeable membrane is produced from a film-forming material selected from hot water soluble polyvinyl alcohol (PVA), polyvinyl acetate, cellulose, cellulose acetate, polysulfone, polyester, polyamide, polyvinyl chloride, spunbonded polyethylene, low-density polyethylene or polyurethane.

Claim 5

An article according to claim 2 wherein said composition (b) comprises, as said microbiocidal compound (i), at least one microbiocidally-effective isothiazolone, having a relatively low water solubility of less than about 1000 ppm, represented by the formula: ##STR2## wherein Y is an unsubstituted or substituted C 1 -C 18 alkyl group, an unsubstituted or substituted C 2 -C 18 alkenyl or alkynyl group, an unsubstituted or substituted C 3 -C 12 cycloalkyl group, an unsubstituted or substituted aralkyl group of 6-10 carbon atoms, or an unsubstituted or substituted aryl group of 6-10 carbon atoms; R is hydrogen, halogen or a C 1 -C 4 alkyl group; R' is hydrogen, halogen or a C 1 -C 4 alkyl group; or R and R' can be taken together with the C═C bond of the isothiazolone ring to form an unsubstituted or substituted benzene ring; or at least one of said isothiazolones stabilized with at least one metal salt used in an amount of about 1-60 weight %, based on weight of 3-isothiazolone and metal salt, said metal salt being represented by the formula: (MX.sub.n) wherein M is a cation of a metal selected from sodium, potassium, calcium, magnesium, copper, iron, zinc, barium, manganese, silver, cobalt and nickel; X is an anion selected from chloride, bromide, iodide, sulfate, nitrate, nitrite, acetate, chlorate, perchlorate, bisulfate, bicarbonate, oxalate, maleate, p-toluene-sulfonate, carbonate, and phosphate; and n is an integer for which the anion X satisfies the valence of the cation M; and, as said solid carrier material (ii), an inert, finely-divided water-insoluble solid material selected from silicaceous diatomaceous earth, high water absorption capacity calcium silicate granular material, clays, charcoal, vermiculite, corn cobs, and wood.

Claim 6

An article according to claim 4 wherein said composition (b) comprises (i) about 1-35 weight %, based on total weight of said composition, of said isothiazolone having a water solubility of about 500 ppm or less wherein Y is an unsubstituted or substituted C 1 -C 18 alkyl group or C 3 -C 12 cycloalkyl group; R is hydrogen or halogen; R' is hydrogen or halogen; or R and R' are taken together with the C═C bond of the 3-isothiazolone ring to form an unsubstituted or substituted benzene ring; or said isothiazolone stabilized with said metal salt; and (ii) about 99-65 weight %, based on total weight of said composition, of said solid carrier material selected from silicaceous diatomaceous earth, high water absorption capacity calcium silicate granular material, and clays.

Claim 7

An article according to claim 5 wherein said composition (b) comprises (i) about 2-25 weight %, based on total weight of said composition, of said isothiazolone wherein Y is n-octyl or t-octyl, R is hydrogen and R' is hydrogen, or said isothiazolone stabilized with said metal salt wherein said metal salt is Mg(NO 3 ) 2 or a mixture of Mg(NO 3 ) 2 and MgCl 2 ; and (ii) about 98-75 weight %, based on total weight of said composition, of silicaceous diatomaceous earth.

Claim 8

An article according to claim 5 wherein said composition (b) comprises (i) about 2-25 weight %, based on total weight of said composition, of said isothiazolone wherein Y is cyclohexyl, R is chlorine and R' is chlorine, or said isothiazolone stabilized with said metal salt wherein said metal salt is Mg(NO 3 ) 2 or a mixture of Mg(NO) 2 and MgCl 2 ; and (ii) about 98-75 weight %, based on total weight of said composition, of silicaceous diatomaceous earth.

Claim 9

An article according to claim 5 wherein said composition (b) comprises (i) about 2-25 weight %, based on total weight of said composition, of said isothiazolone wherein Y is n-octyl or t-octyl, R is chlorine and R' is chlorine, or said isothiazolone stabilized with said metal salt wherein said metal salt is Mg(NO 3 ) 2 or a mixture of Mg(NO 3 ) 2 and MgCl 2 ; and (ii) about 98-75 weight %, based on total weight of said composition, of silicaceous diatomaceous earth.

Claim 10

An article according to claim 5 wherein said isothiazolone is provided in an aqueous solution.

Claim 11

An article according to claim 5 wherein said composition (b) comprises (i), in combination with said isothiazolone having low water solubility, one or both of the isothiazolones having a water solubility of greater than about 1000 ppm wherein Y is methyl, and R is hydrogen and R' is hydrogen or chlorine, or an aqueous solution of said combination of isothiazolones stabilized with said metal salt wherein said metal salt is Mg(NO 3 ) 2 or a mixture of Mg(NO 3 ) 2 and MgCl 2 , the combination comprising about 2-25 weight %, based on total weight of said composition; and (ii) about 98-75 weight %, based on total weight of said composition, of silicaceous diatomaceous earth.