Multi-functional coatings on microporous substrates
A composition is described wherein a coating is provided on a microporous substrate, such as a low surface energy microporous substrate, which coating provides multiple functionalities to the underlying microporous material, while still maintaining porosity within at least a portion of the microporous substrate.
1 ) A composite comprising:
a microporous layer having pore walls and open porosity therein; and
a multi-functional coating on at least a portion of the pore walls of the microporous layer, said multi-functional coating comprising a first functional additive and at least one additional functional additive,
wherein the microporous layer retains at least some open porosity in the coated portion of the microporous structure.
2 ) The composite of claim 1 wherein said composite is microporous.
3 ) The composite of claim 1 wherein the microporous layer comprises expanded polytetrafluoroethylene.
4 ) The composite of claim 1 wherein the first functional additive is oleophobic.
5 ) The composite of claim 1 wherein the first functional additive comprises fluoroacrylate.
6 ) The composite of claim 1 wherein the at least one additional functional additive is a filler.
7 ) The composite of claim 6 wherein the filler is particulate.
8 ) The composite of claim 6 wherein the filler comprises carbon.
9 ) The composite of claim 6 wherein the filler comprises at least one material selected from the group consisting of a pigment, a metal, a metal oxide, and a mixed metal oxide.
10 ) The composite of claim 6 wherein the filler is present at less than or equal to 10% wt. based on total coating weight.
11 ) The composite of claim 6 wherein the filler is present at less than or equal to 5% wt. based on total coating weight.
12 ) The composite of claim 6 wherein the filler is present at less than or equal to 1% wt. based on total coating weight.
13 ) The composite of claim 6 wherein the filler is present at less than or equal to 0.5% wt. based on total coating weight.
14 ) A composite comprising:
a microporous polymer having pore walls and open porosity therein; and
a multi-functional coating on at least a portion of the pore walls of the microporous polymer, said multi-functional coating comprising a first functional additive and at least one additional functional additive,
wherein the microporous polymer retains at least some open porosity in the coated portion.
15 ) The composite of claim 14 wherein the first functional additive comprises a polymer, at least one surfactant in an amount of up to about 50% by weight of the coating based on total coating weight, and at least one water-insoluble alcohol having a C 5 -C 10 linear backbone in an amount of up to about 30% by weight of the aqueous mixture used to coat the microporous polymer.
16 ) The composite of claim 14 , wherein said composite further contains at least one additional coating.
17 ) The composite of claim 16 , wherein said at least one further coating does not fill said pores of said microporous polymer.
18 ) The composite of claim 16 , wherein said at least one further coating substantially fills at least a portion of said pores of said microporous polymer.
19 ) The composite of claim 14 wherein the microporous polymer comprises expanded polytetrafluoroethylene.
20 ) The composite of claim 14 wherein the first functional additive is oleophobic.
21 ) The composite of claim 14 wherein the first functional additive is a fluoropolymer.
22 ) The composite of claim 14 wherein the first functional additive comprises polyfluoroacrylate.
23 ) The composite of claim 14 wherein the first functional additive comprises styrene-butadiene copolymer.
24 ) The composite of claim 14 wherein the first functional additive is hydrophilic.
25 ) The composite of claim 14 wherein the first functional additive comprises polyacrylic acid.
26 ) The composite of claim 14 wherein the first functional additive is sodium polyacrylic acid.
27 ) The composite of claim 14 wherein the first functional additive is polyvinyl alcohol.
28 ) The composite of claim 14 wherein the first functional additive is polyethyleneimine.
29 ) The composite of claim 14 wherein the first functional additive comprises a copolymer of acrylic acid.
30 ) The composite of claim 14 wherein the first functional additive comprises a copolymer of acrylamide.
31 ) The composite of claim 14 wherein the first functional additive comprises a surfactant.
32 ) The composite of claim 14 wherein the first functional additive is a cross-linkable material.
33 ) The composite of claim 14 wherein the first functional additive is elastic.
34 ) The composite of claim 14 wherein the second functional additive is particulate.
35 ) The composite of claim 14 wherein the second functional additive is carbon.
36 ) The composite of claim 14 wherein the second functional additive is antimony oxide.
37 ) The composite of claim 14 wherein the second functional additive is present at less than or equal to 10% wt. based on total coating weight.
38 ) The composite of claim 14 wherein the second functional additive is present at less than or equal to 5% wt. based on total coating weight.
39 ) The composite of claim 14 wherein the second functional additive is present at less than or equal to 1% wt. based on total coating weight.
40 ) The composite of claim 14 wherein the second functional additive is present at less than or equal to 0.5% wt. based on total coating weight.
41 ) A composite comprising:
a microporous layer having a microporous structure having pore walls and open porosity therein; and
a multi-functional coating on at least a portion of the pore walls of the microporous layer, said multi-functional coating comprising a first functional additive and at least one additional functional additive,
wherein the microporous layer retains at least some open porosity in the coated portion, and
wherein at least one of said first functional additive and said second functional additive binds said multi-functional coating to said microporous layer.
42 ) A method for forming a multi-functional coating on a microporous structure comprising:
preparing an aqueous wetting mix;
adding a first functional additive and a at least one additional functional additive to the wetting mix;
coating said microporous structure with said aqueous wetting mix; and
heating the coated microporous material and forming a coating thereon.
43 ) A method for forming a multi-functional coating on a microporous structure comprising:
preparing a solvent wetting mix;
adding a first functional additive and a at least one additional functional additive to the wetting mix;
coating said microporous structure with said solvent wetting mix; and
heating the coated microporous material and forming a coating thereon.