HPMC composition for coating of paper and board for reducing migration of mineral oil hydrocarbons (MOH)
This disclosure relates to an aqueous solution for coating a paper or board surface for reducing MOSH or MOAH migration. The aqueous solution involves hydroxypropyl methylcellulose (HPMC) in an amount of from 10% to 60% (w/w), wherein the viscosity of said hydroxypropyl methylcellulose (HPMC) is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde.
1 . A paper or board comprising a coating comprising an aqueous solution for reducing mineral oil saturated hydrocarbon (MOSH) or mineral oil aromatic hydrocarbon (MOAH) migration on a surface of the paper or board, the aqueous solution consisting of: (a) water and hydroxypropyl methylcellulose (HPMC) in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the hydroxypropyl methylcellulose (HPMC) is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde; or (b) water and HPMC in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the HPMC is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde, and a plasticizer.
2 . The paper or board according to claim 1 , wherein a viscosity of the aqueous solution of either (a) or (b) is from 200 to 80,000 mPa·s determined at 20° C. according to Haake.
3 . The paper or board according to claim 1 , wherein the plasticizer in (b) is present in an amount of up to 20% (plasticizer weight/total weight).
4 . The paper or board according to claim 1 , wherein the plasticizer is selected from the group consisting of ethylene glycol and propylene glycol.
5 . The paper or board according to claim 1 , wherein the water in (a) or (b) is present in an amount of from 40% to 90% (water weight/total weight).
6 . The paper or board according to claim 1 , wherein the plasticizer of (b) is present in an amount from 5% to 10% (plasticizer weight/total weight).
7 . The paper or board according to claim 1 , wherein the coating has a wet-film thickness of 10 μm-150 μm.
8 . A method for reducing mineral oil saturated hydrocarbon (MOSH) or mineral oil aromatic hydrocarbon (MOAH) migration on a paper or board surface, wherein the method comprises:
(a) contacting the paper or board surface with:
(i) an aqueous solution consisting of water and a hydroxypropyl methylcellulose (HPMC) in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the HPMC is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde; or
(ii) an aqueous solution consisting of water, HPMC in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the HPMC is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde, and a plasticizer; and
(b) allowing the aqueous solution of (a) (i) or (a) (ii) to dry on the paper or board surface to create a coating on the paper or board surface that reduces the MOSH or MOAH migration as compared to a paper or board lacking the coating.
9 . A paper or board surface comprising the coating produced in claim 8 .
10 . The paper or board surface according to claim 9 , wherein the paper or board is recycled paper or board or printed paper or board.
11 . The paper or board surface according to claim 9 , wherein the paper or board surface comprises a layer of the coating, and wherein a wet-film thickness of the layer is less than 200 μm.
12 . A packaging material comprising a paper or board surface according to claim 9 .
13 . The method according to claim 8 , wherein the plasticizer is selected from the group consisting of ethylene glycol and propylene glycol.
14 . The method according to claim 8 , wherein the plasticizer is present in an amount from 5% to 10% (plasticizer weight/total weight).
15 . The method according to claim 8 , wherein the coating has a wet-film thickness of 10 μm-150 μm.
16 . A method for applying a coating composition to a paper or board surface, the method comprising
(a) preparing the coating composition, wherein the coating composition consists of:
(i) an aqueous solution consisting of water and a hydroxypropyl methylcellulose (HPMC) in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the HPMC is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde; or
(ii) an aqueous solution consisting of water, HPMC in an amount of from 10% to 60% (HPMC weight/total weight), wherein a viscosity of the HPMC is from 2 mPa·s to 100 mPa·s, determined as a 2% (w/w) solution in water at 20° C. according to Ubbelohde, and a plasticizer, and
(b) contacting the paper or board surface with the coating composition.
17 . The method according to claim 16 , wherein the plasticizer is selected from the group consisting of ethylene glycol and propylene glycol.
18 . The method according to claim 16 , wherein the plasticizer is present in an amount from 5% to 10% (plasticizer weight/total weight).
19 . The method according to claim 16 , wherein the coating composition has a wet-film thickness of 10 μm-150 μm on the paper or board surface in (b).