Coating composition
A coating composition comprising a polymer, such as a copolymer comprising alkylene monomers and unsaturated acid monomers, and at least one phyllosilicate, a product coated with said composition, a method of making said coating compositions and a method of making said coated products.
1. A coating composition comprising:
a copolymer comprising alkylene monomers and unsaturated acid monomers; and
at least one phyllosilicate having a shape factor equal to or greater than about 40,
wherein at least 30% of the acid groups on the copolymer are neutralized.
2. The coating composition of claim 1 , wherein
(a) the alkylene monomers are ethylene monomers; and/or
(b) the unsaturated acid monomers are acrylic acid monomers.
3. The coating composition of claim 1 , wherein the at least one phyllosilicate has a shape factor equal to or greater than about 50.
4. The coating composition of claim 1 , wherein the at least one phyllosilicate is selected from talc, kaolin or a combination thereof.
5. The coating composition of claim 1 , wherein the copolymer is present in an amount ranging from about 10% to about 80% by weight of the dry composition.
6. The coating composition of claim 1 , wherein the coating composition has a moisture vapour transmission rate (MVTR) which is at least about 1.5 times lower than the MVTR of a corresponding coating composition which does not comprise the phyllosilicate, wherein MVTR is measured at 37.8° C. and 90% relative humidity.
7. The coating composition of claim 1 , wherein the moisture vapour transmission rate (MVTR) of the coating composition is less than about 150 gsm/day when measured according to TAPPI T464 at 37.8° C. and 90% relative humidity, using an about 13 gsm coatweight of the coating composition on a base paper coated with a pre-coating, wherein the coatweight of the pre-coating is equal to or greater than about 12 gsm.
8. A coating composition comprising:
a polymer; and
at least one phyllosilicate having a shape factor equal to or greater than about 40;
wherein the moisture vapour transmission rate (MVTR) of the coating composition is less than about 150 gsm/day, for example less than about 100 gsm/day, when measured according to TAPPI T464 at 37.8° C. and 90% relative humidity, using an about 13 gsm coatweight of the coating composition, and wherein at least 30% of the acid groups on the copolymer are neutralized.
9. The coating composition of claim 8 , wherein the coating composition has a Cobb value of less than about 30 gsm when measured according to TAPPI T441 duration 1 minute using an approximately 9 gsm coatweight of the coating composition.
10. The coating composition of claim 9 , wherein the MVTR or Cobb value is measured using a base paper coated with a pre-coating, wherein the coatweight of the pre-coating is equal to or greater than about 12 gsm.
11. The coating composition of claim 8 , wherein the polymer is selected from styrene butadiene, ethylene acrylic acid, polyethylene terephthalate, styrene acrylic latex and any combination thereof.
12. A product, for example a paper product, coated with a coating composition of claim 1 .
13. The product of claim 12 , wherein the moisture vapour transmission rate (MVTR) of the product is less than about 150 gsm/day when measured according to TAPPI T464 at 37.8° C. and 90% relative humidity and using an approximately 13 gsm coatweight.
14. A method of making a coating composition of claim 1 , comprising combining a polymer and at least one phyllosilicate having a shape factor equal to or greater than about 40.
15. A method of making a coated product comprising: providing a product to be coated; and coating the product with a composition of claim 1 .
16. The coating composition of claim 5 , wherein the copolymer is present in an amount ranging from about 10% to about 60% by weight of the dry composition and the at least one phyllosilicate is present in an amount ranging from about 40% to about 90% by weight of the dry composition.
17. The coating composition of claim 5 , wherein the at least one phyllosilicate is present in an amount ranging from about 20% to about 90% by weight of the dry composition.
18. The coating composition of claim 6 , wherein the coating composition has a moisture vapour transmission rate (MVTR) which is at least about 2.5 times lower than the MVTR of a corresponding coating composition which does not comprise phyllosilicate.
19. The coating composition of claim 6 , wherein the coating composition has a moisture vapour transmission rate (MVTR) which is at least about 3.5 times lower than the MVTR of a corresponding coating composition which does not comprise phyllosilicate.
20. The coating composition of claim 1 , wherein the coating composition is a barrier coating.