Adhesive compositions comprising a combination of (i) microfibrillated cellulose and (ii) a metal in an oxidation state of ii or greater

The adhesive composition according to any one of the preceding claims, wherein the solvent is a protic solvent, optionally wherein the solvent comprises or consists of water.

The adhesive composition according to any one of the preceding claims, wherein the microfibrillated cellulose has at least one length scale, i.e. fibril diameter and/or fibril length, that is reduced vis-a-vis the fiber diameter and/or the fiber length of the non-fibrillated cellulose;

• preferably wherein the diameter of the microbrillated cellulose fibrils making up the microfibrillated cellulose of the present invention is in the nanometer range, i.e. from 1 nm to 1000 nm, preferably, and on average, from 10 nm to 500 nm.

The adhesive composition according to any one of the preceding claims, wherein the amount of microfibrillated cellulose in said adhesive composition is from 0.001 to 10 wt. %. (w/w), preferably from 0.01 to 5 wt. %, even more preferably from 0.01 to 1 wt. %, even more preferably from 0.01 to 0.5 wt. %, even more preferably from 0.01 to 0.3 wt. %, based on the total weight of the adhesive composition;

• or:
• wherein the weight ratio of microfibrillated cellulose to the at least one compound that (a) is capable of polymerizing or has already partly or fully polymerized, and that (b) has at least two groups available for hydrogen bonding, preferably OH groups, that are capable of crosslinking with at least one functional group of the microfibrillated cellulose and/or the at least one metal in an oxidation state of II or higher, is from 0.0001 to 0.5, preferably from 0.0002 to 0.3, more preferably from 0.0004 to 0.2, even more preferably from 0.0005 to 0.1 or 0.0005 to 0.03 or 0.001 to 0.01.

The adhesive composition according to any one of the preceding claims, wherein the solvent is present in an amount of from 20 to 90 wt. %, preferably from 30 to 80 wt. %, more preferably from 40 to 80 wt. %, even more preferably from 50 to 80 wt. %, such as from 65 to 80 wt. %, preferably 66 to 79 wt. %, based on the total weight of the adhesive composition.

The adhesive composition according to any one of the preceding claims, wherein the composition comprises no or only trace amounts of boron-containing crosslinking agents, preferably wherein the adhesive composition comprises no or only trace amounts of borax and boric acid, further preferably wherein the adhesive composition preferably comprises no or only trace amounts of boron.

The adhesive composition according to any one of the preceding claims, wherein the compound that (a) is capable of polymerizing, or has already partly or fully polymerized, and that (b) has at least two groups available for hydrogen bonding, preferably OH groups, that are capable of crosslinking with at least one functional group of the microfibrillated cellulose and/or the at least one metal in an oxidation state of II or higher is selected from the following compounds:

• at least one starch or starch derivative, at least one polyvinyl alcohol, at least one polyvinyl acetate, at least one polyethylene glycol, at least one polypropylene glycol, at least one polysaccharide, at least one carbohydrate, at least one polypeptide, at least one acrylate, at least one acrylamide, at least one ethylene oxide, at least one propylene oxide, at least one glycol, at least one polyether, at least one polyester, at least one polyol, at least one epoxy resin, at least one polyurethane, at least one polyacrylate such as polymethylmethacrylate (PMMA), at least one polyurea and at least one carbamide, or any combination thereof;
• preferably from at least one starch or starch derivative, and at least one polyvinyl alcohol.