USE OF AQUEOUS DISPERSIONS AS PRIMERS
The present invention relates to the use of aqueous UV-reactive primers for the coating of substrates based on ethylene vinyl acetate copolymers (EVA copolymers) or rubber. The present invention further provides a novel method for joining articles using an aqueous UV-reactive primer.
1 .- 11 . (canceled)
12 . A method comprising coating a substrate with an aqueous dispersion as primer,
wherein said aqueous dispersion comprises
a) a polymer selected from the group consisting of polyurethane, polyurea, and polyurethane-polyurea,
b) an ethylenically unsaturated compound, and
c) a photoinitiator,
wherein the substrate is selected from the group consisting of ethylene vinyl acetate copolymer, rubber, polyolefin, and mixtures thereof.
13 . A method for joining articles, comprising
I) coating an article with an aqueous dispersion as primer which comprises
a) a polymer selected from the group consisting of polyurethane, polyurea, and polyurethane-polyurea,
b) an ethylenically unsaturated compound, and
c) a photoinitiator;
II) removing water;
III) irradiating with actinic radiation;
IV) coating the article with an adhesive;
V) removing water; and
VI) bringing the article into contact with itself or with a further article which has optionally been treated according to method steps I) to V) or IV) to V).
14 . The method of claim 13 , wherein the polymer in step I) is crystalline or semi-crystalline.
15 . The method of claim 13 , wherein in a DSC measurement according to DIN 65467 at a heating rate of 20 K/min, the aqueous dispersion in step I) has a melting peak which corresponds to a melt enthalpy >3 J/g.
16 . The method of claim 13 , wherein the aqueous dispersion in step I) comprises an ethylenically unsaturated double bond.
17 . The method of claim 13 , wherein the ethylenically unsaturated compound is selected from the group consisting of esters of acrylic acid, esters of methacrylic acid, esters of crotonic acid, vinyl ethers, vinyl esters, and vinyl aromatic compounds.
18 . The method of claim 13 , wherein the ethylenically unsaturated compound comprises aromatic or cycloaliphatic groups.
19 . The method of claim 13 , wherein the adhesive is a heat-activatable adhesive comprising an aqueous dispersion which comprises a polymer selected from the group consisting of polyurethane, polyurea, and polyurethane-polyurea.
20 . The method of claim 13 , additionally comprising Va) supplying heat to the substrate.
21 . The method of claim 13 , wherein the article is a material selected from the group consisting of ethylene vinyl acetate copolymers, rubber, styrene butadiene rubber, nitrile butadiene rubber, thermoplastic rubber, natural rubber, ethylene-propylene-diene rubber, polyolefins, thermoplastic materials, and mixtures thereof.
22 . An article produced by the method of claim 13 .