Waterborne hydrophobic barrier coatings derived from copolymers of higher vinyl esters
View Patent ↗A blend comprising a paraffin wax emulsion and a polymer emulsion, wherein the polymer contains polymerized units of one or more C 1-12 ester of acrylic or methacrylic acid and a vinyl ester of a C 8-13 neo-acid. When the blend is applied as a coating to a substrate, such as a nonwoven web, a nonwoven absorbent pad, a nonwoven textile, or a textile fabric, and dried, it has a hydrostatic head barrier sufficient to prevent passage of aqueous fluids but allow passage of water vapor through it. A multi-layer material comprising at least one layer of a nonwoven web, an absorbent pad, or a textile, and at least one layer of the above described blend.
1. A blend for use as a barrier coating on a substrate, wherein the barrier coating provides a hydrostatic head barrier sufficient to prevent passage of aqueous fluids but allow passage of water vapor through said barrier coating, said blend comprising a paraffin wax emulsion and a polymer emulsion, said polymer emulsion comprising a polymer containing polymerized units of one or more C 1-12 esters of acrylic or methacrylic acid and a vinyl ester of a C 8-13 neo-acid obtained from a single or mixture of tri- and tetramers of propylene, the polymer having a T g of −15 to −70° C.
2. The blend of claim 1 wherein the polymer has polymerized units of:
(a) 5-40 wt % of a vinyl ester of a C 8-13 neo-acid;
(b) 30-80 wt % of a C 1-12 alkyl ester of acrylic acid or a C 1-12 alkyl ester of methacrylic acid;
(c) 0-20% wt % of a vinyl ester of a saturated aliphatic acid;
(d) 0-30 wt % ethylene, styrene or butadiene;
(e) 0-20 wt % a di-(C 1-13 )alkyl maleate or a di-(C 1-13 )alkyl fumarate;
(f) 0-5 wt % of a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate;
(g) 0-5 wt % acrylamide or methacrylamide; and,
(h) 0-10 wt % of an alpha, beta-ethylenically unsaturated monocarboxylic acid, based on the total weight of monomers in the polymer.
3. The blend of claim 1 wherein the polymer has polymerized units of:
(a) 15-30 wt % of a vinyl ester of a C 8-13 neo-acid;
(b) 40-70 wt % of a C 1-12 alkyl ester of acrylic or a C 1-12 alkyl ester of methacrylic acid;
(c) 0-10 wt % of a vinyl ester of a saturated aliphatic acid;
(d) 0-20 wt % ethylene, styrene or butadiene;
(e) 0-10 wt % a di-(C 1-13 )alkyl maleate or a di-(C 1-13 )alkyl fumarate;
(f) 0-5 wt % of a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate;
(g) 0-5 wt % acrylamide or methacrylamide; and,
(h) 0-10 wt % of an alpha, beta-ethylenically unsaturated monocarboxylic acid.
4. The blend of claim 1 wherein the hydrostatic head barrier is at least 60 mm.
5. The blend of claim 1 comprising, on a 100% dry weight solids basis:
10–90 wt %
Polymer Emulsion
10–90 wt %
Paraffin Wax Emulsion
0–80 wt %
Water Soluble Polymer or
Protective Colloid
0–5 wt %
Fluoro Surfactant
0–10 wt %
Other components.
6. The blend of claim 1 comprising, on a 100% dry weight solids basis
20–80 wt %
Polymer Emulsion
20–80 wt %
Paraffin Wax Emulsion
0–10 wt %
Water Soluble Polymer or
Protective Colloid
0–3 wt %
Fluoro Surfactant
0–5 wt %
Other components.
7. The blend of claim 1 wherein the polymer emulsion has a T g of −20° C. to −50° C.
8. The blend of claim 1 wherein the paraffin wax emulsion further comprises polyethylene wax, carnauba wax or ethylene acrylic acid.