Fast film formation water based barrier coating
View Patent ↗The invention relates to a composition which, when mixed with a polymer composition, allows for the formation of a continuous and cohesive film. The film is characterized in that it provides water, grease and oil resistance, provides a water vapor barrier and can be used as wax replacement treatment and a top coat for flexible packaging, but also on other substrates. This film is formed at a very fast set speed without the need of thermal energy. The composition contains i) a salt of one or more of myristic, palmitic and stearic acid; and preferably also ii) a C 9 -C 18 fatty acid complex of a metal ion, said metal ion having an oxidation state of at least 3. The invention also provides processes and coated substrates.
1. A process for providing water, vapour, oil and grease resistance to a paper or paperboard material comprising:
I. combining a) a salt of one or more of myristic, palmitic and stearic acid; and b) a polymeric composition comprising a polymer, a copolymer, or mixtures of polymers or copolymers, in the presence of an aqueous solvent, to form a water-based film-forming composition, said film-forming composition comprises 20 to 40% by weight of a) and 80 to 60% by weight of b), based on the total weight of a) and b);
II. coating a surface of the material with said water-based film-forming composition; and
III. allowing a film of said polymeric composition to form on the material at a temperature less than 50° C.
2. The process of claim 1 , wherein step I) further comprises combining a) and b) with c) a C 9 -C 18 fatty acid complex of a metal ion, said metal ion having an oxidation state of at least 3.
3. The process of claim 2 wherein said salt in a) is calcium stearate and said metal ion in c) is chromium ion.
4. The process of claim 2 wherein a) and c) are in a ratio of 5:1 to 20:1.
5. The process of claim 1 , wherein said film in step III is formed without added thermal or microwave energy.
6. The process of claim 1 , wherein said film in step III is formed without direct heat.
7. The process of claim 1 , wherein said water-based film-forming composition comprise 5 to 30% by weight of said salt a), 0 to 30% by weight of filler, based on the total weight of the water-based film-forming composition.
8. The process of claim 6 , wherein said film in step III is formed in less than 1 minute.
9. The process of claim 8 , wherein said salt of one or more of myristic, palmitic and stearic acid is selected from the group consisting of sodium, potassium, calcium, and zinc salts.
10. The process of claim 9 , wherein said salt is calcium stearate or zinc stearate.
11. The process of claim 9 , wherein said film is formed at a temperature of 15 to 35° C.
12. A process for providing water, vapour, oil and grease resistance to a material comprising:
I. combining a) a salt of one or more of myristic, palmitic and stearic acid; b) a polymeric composition comprising a polymer, a copolymer, or mixtures of polymers or copolymers; and c) a tackifier resin, in the presence of an aqueous solvent, to form a water-based film-forming composition;
II. coating a surface of the material with said water-based film-forming composition; and
III. allowing a film of said polymeric composition to form on the material at a temperature less than 50° C.
13. The process of claim 12 , wherein said tackifier resin is a glycerol ester of hydrogenated rosin.
14. The process of claim 1 , wherein said material is a cellulose based material.
15. A process for providing water, vapour, oil and grease resistance to a material comprising:
I. combining a) a salt of one or more of myristic, palmitic and stearic acid selected from the group consisting of sodium, potassium, calcium, and zinc salts; b) a polymeric composition comprising a polymer, a copolymer, or mixtures of polymers or copolymers; and c) a tackifier resin, in the presence of an aqueous solvent, to form a water-based film-forming composition; said film-forming composition comprising 20 to 40% by weight of a) and 80 to 60% by weight of b), based on the total weight of a) and b);
II. coating a surface of the material with said water-based film-forming composition; and
III. allowing a film of said polymeric composition to form, in less than 1 minute without direct heat, on the material at a temperature less than 50° C.
16. The process of claim 15 , wherein said tackifier resin is a glycerol ester of hydrogenated rosin.
17. The process of claim 8 , wherein said material is a cellulose based material.