Composition and process for applying hydrophobic coating to fibrous substrates
Fabrics are treated with a hydrophobic treatment that includes at least one hydrophobic monomer and a crosslinker. The treatment is low in volatile organic compounds and water. It is a liquid at 22° C. or a suspension having a phase that is liquid at 22° C. The monomer and crosslinker are cured in a free radical polymerization to form a hydrophobic coating on a fibrous substrate.
1. A curable coating composition comprising
a) at least one free-radical-curable monomer having exactly one polymerizable group per molecule, the free-radical-curable monomer having at least one hydrocarbyl group that has at least eight carbon atoms bonded directly or indirectly to the polymerizable group, wherein the hydrocarbyl group may be nonfluorinated, partially fluorinated or perfluorinated, the free-radical-curable monomer having a boiling temperature equal to or greater than 100° C.,
b) at least one crosslinking monomer having at least two free-radical-curable polymerizable groups and a boiling temperature equal to or greater than 100° C.;
c) silicone oil; and
d) a heat-activatable free radical initiator,
wherein the coating composition is a liquid at 22° C. or a suspension of one or more solids in a liquid phase at 22° C., wherein the coating composition comprises, based on the total weight of the coating composition: 4 to 85 weight-% of component a), 2 to 25 weight-% of component b), 10 to 50 weight-% of the silicone oil, 1 to 10 weight percent of one or more the heat-activatable free-radical initiators and 0 to 35% of one or more functional attribute materials.
2. The coating composition of claim 1 which contains no more than 10% by weight of organic compounds that have boiling temperatures below 100° C. and no more than 5% by weight water, based on the entire weight of the coating composition.
3. The coating composition of claim 2 wherein component a) has a solubility in water of no greater than 1 part by weight per 100 parts by weight of water at 30° C., and water is soluble in the component a) to the extent of no greater than 1 part by weight per 100 parts by weight of component a) at 30° C.
4. The coating composition of claim 3 , wherein the polymerizable group of component a) is an acrylate or methacrylate group.
5. The coating composition of claim 4 , wherein the hydrocarbyl group of component a) is an alkyl group containing 10 to 20 carbon atoms.
6. The coating composition of claim 4 wherein component a) is a mixture of at least one monomer that is a liquid at 22° C. and at least one monomer that is a solid at 22° C.
7. The coating composition of claim 1 wherein component b) includes at least one polyacrylate compound having 2 to 8 acrylate and/or methacrylate groups per molecule, at least one drying oil, or a mixture of thereof.
8. The coating composition of claim 1 wherein component b) includes one or more of, 1,6-hexanediol diacrylate, 1,8-octanediol diacrylate, cyclohexane dimethanol diacrylate, trimethylolpropane triacrylate, glycerin triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythriol hexacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,8-octanediol dimethacrylate, cyclohexane dimethanol dimethacrylate, trimethylolpropane trimethacrylate, glycerin trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythriol hexmethacrylate, linseed oil, safflower oil and tung oil.
9. The coating composition of claim 1 which comprises, based on the total weight of the coating composition, 16 to 70 weight-% of component a), 3 to 20 weight-% of component b), 25 to 50 weight-% of the silicone oil, 1 to 10 weight percent of the heat-activatable free-radical initiators and 1 to 25 weight-% of one or more functional attribute materials.
10. A curable coating composition comprising
a) at least one free-radical-curable monomer having exactly one polymerizable group per molecule, the free-radical-curable monomer having at least one hydrocarbyl group that has at least eight carbon atoms bonded directly or indirectly to the polymerizable group, wherein the hydrocarbyl group may be nonfluorinated, partially fluorinated or perfluorinated, the free-radical-curable monomer having a boiling temperature equal to or greater than 100° C.,
b) at least one crosslinking monomer having at least two free-radical-curable polymerizable groups and a boiling temperature equal to or greater than 100° C.; and
c) silicone oil;
wherein the coating composition is a liquid at 22° C. or a suspension of one or more solids in a liquid phase at 22° C. and the coating composition contains, based on the total weight of the coating composition, 10 to 35% by weight of a solid component a) monomer, 6 to 30% by weight of a liquid component a) monomer, 3-20% of component b) wherein component b) includes one or more of an alkane diol diacrylate, a pentaerythritol or dipentaerythritol polyacrylate and a drying oil, and 20 to 50% of the silicone oil.