Aqueous Coating Composition, Substrate Coated With Such Composition, Process for Controlling Aquatic Biofouling Using Such Coating Composition

An aqueous coating composition comprising an acrylic polymer dissolved in a liquid phase comprising water and a water-miscible solvent, wherein the coating composition comprises at least 50 wt % water, and wherein the acrylic polymer is a film-forming polymer obtainable by free radical polymerization of a monomer mixture comprising:

• in the range of from 30 to 70 wt % of a poly(ethyleneglycol) (meth)acrylic monomer a. of general formula (I):
• wherein:
• R1 is an H atom or a methyl radical;
• A is an O atom or a NH radical, preferably an O atom;
• R2 is a H atom, an alkyl radical with 1 to 6 carbon atoms or a phenyl radical;
• and
• n is an integer in the range of from 2 to 100;
• in the range of from 2 to 20 wt % of an alkoxysilyl or alkoxyalkylsilyl functional (meth)acrylic monomer b. of general formula (II):
• CH2═CR1—CO-A-Ra—[X—Ra]k—Si(R3)(3−n)(OR4)n (II)
• wherein:
• R1 is an H atom or a methyl radical;
• A is an O atom or a NH radical, preferably an O atom;
• Ra—[X—Ra]k is a group having from 1 to 20 carbon atoms, in which;
• each Ra is independently selected from (i) aliphatic hydrocarbon groups, and (ii) aromatic hydrocarbon groups optionally having one or two substituents selected from (i) above;
• wherein each of the aliphatic hydrocarbon and aromatic hydrocarbon groups in (i) or (ii) above can optionally be substituted with one or more substituents selected from —C1-3 alkyl, —N(Rb)2, and —ORb;
• each Rb is independently selected from H and C1-3 alkyl;
• X is selected from A, —C(O)O—, —OC(O)—, —C(O)NRb— and —NRbC(O)—;
• k is a whole number in the range of from 0 to 3;
• n is 1, 2, or 3, preferably is 2 or 3;
• R3 and R4 are, independently, an alkyl or an alkoxyalkyl radical with 1 to 6 carbon atoms;
• and
• in the range of from 10 to 68 wt % of a hydrophobic ethylenically unsaturated monomer c. selected from the group consisting of styrene, alkylated styrene, and a (meth)acrylic monomer of general formula (III):
• CH2═CR1—CO-A-R5 (III)
• wherein:
• R1 is an H atom or a methyl radical;
• A is an O atom or a NH radical;
• and
• R5 is a hydrocarbon radical with 1 to 18 carbon atoms, preferably an alkyl radical with 1 to 12 carbon atoms or an (alkyl)aryl radical with 6 to 12 carbon atoms.