Process for inhibiting fouling of an underwater surface

Claim 2

A process for inhibiting fouling on an underwater surface comprising applying to the surface of a mold for the production of a boat hull or part thereof a coating composition comprising: (a) a curable polyorganosiloxane, (b) a curing agent capable of curing the polyorganosiloxane (A) to a silicone elastomer, (c) a polyisocyanate, and (d) a compound having more than one active hydrogen group or hydrolyzable to a compound having more than one active hydrogen group, said active hydrogen group being capable of reacting with the polyisocyanate (C) to form a polyurethane, polyurea or poly (urethane-urea), into which mold are applied layers of curable resin which are cured in the mold to form a boat hull or part thereof having the coating composition as its outermost layer.

Claim 3

A process according to claim 1, in which the weight ratio of the polyorganosiloxane (A) plus curing agent (B) to the polyisocyanate (C) plus active-hydrogen-providing compound (D) in the coating composition is 60:40 to 95:5.

Claim 4

A process according to claim 2, in which said weight ratio of 70:30 to 90:10.

Claim 5

A process according to claim 1, in which the coating composition also contains a non-reactive fluid polyorganosiloxane.

Claim 6

A process according to claim 4, in which said nonreactive fluid polyorganosiloxane is methyl phenyl silicone oil.

Claim 7

A process according to claim 1, in which said coating composition also contains a non-reactive fluid organic compound.

Claim 8

A process for inhibiting fouling on an underwater surface comprising applying to the surface a coating composition comprising: (A) a curable polyorganosiloxane, (B) a curing agent capable of curing the polyorganosiloxane (A) to a silicone elastomer, (C) a polyisocyanate, and (D) a compound having more than one active hydrogen group or hydrolyzable to a compound having more than one active hydrogen group, said active hydrogen group being capable of reacting with the polyisocyanate (C) to form a polyurethane, polyurea or poly(urethane-urea), in which component A reacts primarily with component B and not to any substantial extent with either component C or component D, and in which component B reacts primarily with component A rather than with either of components C or D, and in which components C and D each react more readily with each other than with either of components A or B.

Claim 9

A process for inhibiting fouling on an underwater surface comprising applying to the surface a coating composition comprising: (A) a curable polyorganosiloxane, (B) a curing agent capable of curing the polyorganosiloxane (A) to a silicone elastomer, (C) a polyisocyanate, and (D) a compound having more than one active hydrogen group or hydrolyzable to a compound having more than one active hydrogen group, said active hydrogen group being capable of reacting with the polyisocyanate (C) to form a polyurethane, polyurea or poly(urethane-urea), in which component A reacts primarily with component B and not to any substantial extent with either component C or component D, and in which component B reacts primarily with component A rather than with either of components C or D, and in which components C and D each react more readily with each other than with either of components A or B.

Claim 10

A process according to claim 7, in which the polyorganosiloxane (A) is a polydiorganosiloxane having hydroxyl end groups.

Claim 11

A process according to claim 7, in which the curing agent (B) is an alkoxysilane.

Claim 12

A process according to claim 9, in which said alkoxysilane is tetraethyl orthosilicate.

Claim 13

A process according to claim 7, in which the polyisocyanate (C) comprises a flexible polymer chain tipped with isocyanate groups and has a molecular weight of 600 to 3000 and the active-hydrogen-providing compound (D) has a molecular weight less than 300.

Claim 14

A process according to claim 11, in which the polyisocyanate (C) is an isocyanate-tipped polyether.

Claim 15

A process according to claim 11, in which the polyisocyanate (C) is tipped with a cycloaliphatic diisocyanate.

Claim 16

A process according to claim 11, in which the active-hydrogen-providing compound (D) is a polyamine or hydroxyamine.

Claim 17

A process according to claim 14, in which the compound (D) is an aromatic diamine.

Claim 18

A process according to claim 7, in which the polyisocyanate (C) has a molecular weight less than 300 and the active-hydrogen-providing compound (D) is a flexible polymer chain tipped with hydroxyl and/or amine groups and has a molecular weight of 600 to 3000.

Claim 19

A process according to claim 7, in which the active-hydrogen-providing compound (D) is an oxazolidine.

Claim 20

A process according to claim 17, in which said oxazolidine is a compound containing at least two oxazolidine groups.

Claim 21

A process according to claim 17, in which said oxazolidine has the formula: ##STR3## where R is a divalent organic group and R 1 to R 6 are each independently selected from hydrogen atoms and inert substituents.

Claim 22

A process according to claim 17, in which the coating composition comprises a carboxylic acid.

Claim 23

A process according to claim 7, in which the weight ratio of the polyorganosiloxane (A) plus curing agent (B) to the polyisocyanate (C) plus active-hydrogen-providing compound (D) in the coating composition is 60:40 to 95:5.

Claim 24

A process according to claim 21, in which said weight ratio is 70:30 to 90:10.

Claim 25

A process according to claim 7, in which the coating composition also contains a non-reactive fluid polyorganosiloxane.

Claim 26

A process according to claim 23, in which said non-reactive fluid polyorganiosiloxane is a methyl phenyl silicone oil.

Claim 27

A process according to claim 7, in which said coating composition also contains a non-reactive fluid organic compound selected from the group consisting of lubricating mineral oils, low molecular weight polybutene, petrolatum and liquid paraffin/petrolatum mixtures.