Coated paper for use as packaging material
The present invention relates to a, preferably heat-sealable, coated paper comprising a cellulose layer and a coating on at least one side of the cellulose layer, wherein the coating comprises a wax and a polymer selected from the group consisting of polyester, polysaccharide, polysaccharide ester, polysaccharide ether and polysaccharide ether ester, and a packaging comprising the coated paper, as well as a method of manufacturing a coated paper.
1 . A coated paper comprising a cellulose layer and a coating on at least one side of the cellulose layer;
wherein the coating comprises a wax and a polymer, and one or more of: a filler, a rheology modifier, or a softener;
wherein the polymer is selected from the group consisting of polyester, polysaccharide, polysaccharide ester, polysaccharide ether and polysaccharide ether ester;
wherein the coated paper has a moisture vapor transmission rate of less than 200 (g/(m 2 d)); and
wherein the wax and polymer act together to form a heat-seal layer achieving heat sealability at 100° C. to 250° C.
2 . The coated paper according to claim 1 , wherein the coating comprises a first coating layer and a second coating layer, the first coating layer comprises the wax and a filler, and the second coating layer comprises the wax and the polymer.
3 . The coated paper according to claim 1 , wherein the filler is an inorganic filler.
4 . The coated paper according to claim 3 , wherein the inorganic filler is kaolinite.
5 . The coated paper according to claim 2 , wherein the first coating layer comprises 50 to 98 wt.-%, of the filler relative to the basis weight of the first coating layer.
6 . The coated paper according to claim 2 , wherein the first coating layer comprises sugarcane wax and kaolinite.
7 . The coated paper according to claim 2 , wherein the basis weight of the first coating layer is 1 to 7 g/m 2 and the basis weight of the second coating layer is 3 to 10 g/m 2 .
8 . The coated paper according to claim 1 , wherein the wax is a plant wax.
9 . The coated paper according to claim 8 , wherein the plant wax is one or more selected from the group consisting of candelilla wax, carnauba wax, rice bran wax, soy wax, sugarcane wax and sunflower wax.
10 . The coated paper according to claim 1 , wherein the polymer is a polyester selected from the group consisting of polyhydroxyalkanoate, polylactic acid, polyglycolic acid, polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate, and polylactic acid-polyethylene glycol.
11 . The coated paper according to claim 1 , wherein the polymer is thermoplastic starch.
12 . The coated paper according to claim 1 , wherein the polymer is selected from the group consisting of polyhydroxybutyrate, polylactic acid, polylactic acid-polyethylene glycol block copolymer, and thermoplastic starch.
13 . The coated paper according to claim 1 , wherein the coating further comprises at least one additive.
14 . The coated paper according to claim 13 , wherein the additive is at least one of a rheology modifier and a softener.
15 . The coated paper according to claim 14 , wherein the softener is glycerine.
16 . The coated paper according to claim 14 , wherein the rheology modifier is cellulose, starch or a derivative thereof.
17 . The coated paper according to claim 1 , wherein the coating comprises 10 to 90 wt.-% of the wax and 10 to 90 wt.-% of the polymer.
18 . The coated paper according to claim 1 , wherein the wax has a dropping point in the range of 60° C. to 120° C.
19 . The coated paper according to claim 1 , wherein the polymer has a melting point in the range of 60° C. to 180° C.
20 . The coated paper according to claim 1 , wherein the polymer is a thermoplastic polymer.
21 . The coated paper according to claim 1 , wherein the polymer is a biomass-based polymer.
22 . The coated paper according to claim 1 , which is biodegradable.
23 . The coated paper according to claim 1 , which does not contain a petroleum-based synthetic polymer.
24 . The coated paper according to claim 1 , wherein the basis weight of the coating on one side of the cellulose layer is 1 to 25 g/m 2 .
25 . The coated paper according to claim 1 , wherein the cellulose layer has a basis weight of 20 to 100 g/m 2 .
26 . The coated paper according to claim 1 , further having basis weight of 21 to 125 g/m 2 .
27 . The coated paper according to claim 1 , which is extensible.
28 . The coated paper according to claim 1 , which is creped.
29 . The coated paper according to claim 1 , wherein the cellulose layer is saturated with the coating composition or a resin.
30 . A packaging comprising the coated paper according to claim 1 .