Composition and methods for providing coatings; materials; application techniques; and, resulting coated substrates
Techniques and compositions for applying films to a variety of substrates, from water-borne coating compositions, are provided. The techniques involve providing desiccant and applying the desiccant with water-borne film-forming composition, in application to a substrate. The desiccant composition provides for take up of free water in of the film-forming composition, without total reliance on ambient conditions, to advantage. Compositions, methods, techniques and resulting constructions are described. The techniques can be applied in wet thick film applications, but are not limited to such applications.
1. A method of forming a film on a substrate; the method including a step of:
(a) applying, by spray coating, a wet, water-borne, film to the substrate; the wet film comprising:
(i) water-borne film forming composition; and,
(ii) desiccant that is at least partially active, in an amount adequate to at least partially take up free water in the wet, water-borne, film;
(iii) the step of applying comprises mixing by impingement mixing, before application on the substrate, two component streams: a first comprising the water-borne film forming composition; and, a second comprising the desiccant.
2. A method according to claim 1 wherein:
(a) the step of applying comprises mixing the two component streams outside of an impingement-mixing spray apparatus.
3. A method according to claim 1 wherein:
(a) the step of applying comprises mixing the two component streams inside of an impingement-mixing spray apparatus.
4. A method according to claim 3 including a step of: (a) purging the impingement-mixing spray apparatus after the step of applying.
5. A method according to claim 4 wherein: (a) the step of purging comprises a gas purge.
6. A method according to claim 4 wherein: (a) the step of purging comprises a liquid purge.
7. A method according to claim 1 wherein: (a) the step of applying comprises mixing, before applying to the substrate, first and second component streams:
the first comprising the water-borne film forming composition; and, the second comprising the desiccant in a carrier fluid.
8. A method according to claim 1 wherein: (a) the desiccant is present in at least a sufficient amount to absorb 5% of free water in the water-borne film forming composition, as applied.
9. A method according to claim 1 wherein: (a) the step of applying includes mixing water-borne film forming composition with desiccant composition, prior to application, in a volume ratio of at least 1:1 of water-borne film forming composition-to-desiccant composition.
10. A method according to claim 1 wherein: (a) the desiccant is selected from: Portland cement; modified Portland cement; calcium oxide; perlite; vermiculite; attapulgite clay(s); bentonite clay(s); phosphorous pentoxide; aluminum phosphate, aerogel(s); and mixtures thereof.
11. A method according to claim 1 wherein: (a) the desiccant is contained in a desiccant composition comprising desiccant dispersed in non-aqueous carrier selected from water miscible and soluble materials.
12. A method according to claim 11 wherein: (a) the non-aqueous carrier is, at least in part, coalescing solvent for the polymer in the aqueous-based film forming composition.
13. A method according to claim 1 wherein: (a) the film forming composition comprises acrylic polymer.
14. A method according to claim 1 wherein: (a) the film forming composition comprises styrene-butadiene rubber.
15. A method according to claim 1 wherein: (a) the film forming composition comprises polyvinyl chloride.
16. A method according to claim 1 wherein: (a) the film forming composition comprises of a blend of acrylic copolymer with polyurethane polymer.
17. A method according to claim 1 wherein: (a) the wet film, as applied, further includes suspending agent.
18. A method according to claim 1 wherein: (a) the film forming composition includes pH adjustor.
19. A method of forming a film on a substrate; the method including a step of:
(a) applying, by spray coating, a wet, water-borne, film to the substrate; the wet film comprising:
(i) water-borne film forming composition; and,
(ii) desiccant that is at least partially active, in an amount adequate to at least partially take up free water in the wet, water-borne, film;
(iii) the step of applying comprises mixing, before application on the substrate, first and second component streams: the first comprising the water-borne film forming composition; and, the second comprising the desiccant in a carrier fluid.
20. A method of forming a film on a substrate; the method including a step of:
(a) applying, by spray coating, a wet, water-borne, film to the substrate; the wet film comprising:
(i) water-borne film forming composition; and,
(ii) desiccant that is at least partially active, in an amount adequate to at least partially take up free water in the wet, water-borne, film, wherein the desiccant is included in a desiccant composition comprising desiccant dispersed in non-aqueous carrier selected from water miscible and water soluble materials;
(iii) the step of applying comprises mixing, before application on the substrate, two component streams: a first comprising the water-borne film forming composition; and, a second comprising the desiccant composition.
21. A method of forming a film on a substrate; the method including steps of:
(a) applying, by spray coating, a wet, water-borne, film to the substrate; the wet film comprising:
(i) water-borne film forming composition; and,
(ii) desiccant, that is at least partially active, in an amount adequate to at least partially take up free water in the wet, water-borne, film as applied;
(iii) the step of applying comprising simultaneous continuous stream mixing two component streams as the application occurs: a first comprising the water-borne film forming composition; and, a second comprising desiccant composition, during application; and,
(b) allowing the film to set up on the substrate.