Polysaccharide coatings for paper
Coating compositions that can provide grease and oil resistant coating for substrates, especially paper and textile substrates, are disclosed. The coating compositions comprise water insoluble α-(1,3-glucan) polymer and/or dextran polymer and optionally other additives.
1. A coated substrate that comprises: a substrate and wherein at least a portion of the substrate is coated with a continuous layer of a coating composition,
wherein the coating composition comprises polyvinyl alcohol and a water-insoluble α-1,3-glucan polymer having 90% or greater α-1,3-glycosidic linkages, and the substrate is paper, paper board, cardboard, or corrugated board.
2. The coated substrate of claim 1 , wherein the water-insoluble α-1,3-glucan polymer comprises greater than or equal to 95% α-1,3-glycosidic linkages.
3. The coated substrate of claim 1 , wherein the coating composition further comprises one or more additives.
4. The coated substrate of claim 1 , wherein the coating composition is essentially free from starch or hydroxyalkyl starch.
5. The coated substrate of claim 1 , wherein the water-insoluble α-1,3-glucan polymer has greater than or equal to 99% α-1,3-glycosidic linkages.
6. The coated substrate of claim 1 , wherein the coated substrate resists grease and/or oil.
7. The coated substrate of claim 1 , wherein the continuous layer is dry and has a thickness in the range of 0.1 to 50 micrometers.
8. The coated substrate of claim 1 , wherein the substrate is paper.
9. The coated substrate of claim 1 , wherein the water-insoluble α-1,3-glucan polymer has less than 1% α-1,3,6-glycosidic branch points.
10. The coated substrate of claim 1 , wherein the water-insoluble α-1,3-glucan polymer has a number average degree of polymerization in the range of 55 to 10,000.
11. The coated substrate of claim 1 , wherein the water-insoluble α-1,3-glucan polymer consists of α-1,3-glucan.
12. The coated substrate of claim 1 , wherein grease is in contact with the continuous layer of the coating composition, but the grease is not in contact with the substrate.
13. The coated substrate of claim 1 , wherein oil is in contact with the continuous layer of the coating composition, but the oil is not in contact with the substrate.