Dispersion
The invention relates to a dispersion of melamine powder in a liquid or an aminoplast resin in a liquid, whereby the dispersion contains a dispersant, said dispersant comprising a styrene-maleic anhydride copolymer. The invention further relates to a method for preparing the said dispersant, and to its use in adhesive compositions, coatings or laminates.
1 . Dispersion of melamine powder or an aminoplast resin in a liquid, whereby the dispersion contains a dispersant, said dispersant comprising a styrene-maleic anhydride copolymer.
2 . Dispersion according to claim 1 , wherein the styrene-maleic anhydride copolymer has been treated so as to render it soluble in aqueous systems.
3 . Dispersion according to claim 1 , wherein the weight-averaged molecular weight of the styrene-maleic anhydride copolymer lies between 1,000 and 1,000,000, and wherein the molar ratio of styrene to maleic anhydride in the styrene-maleic anhydride copolymer lies between 1:0.5 and 1:1.
4 . Dispersion of melamine powder according to claim 1 , wherein the amount of melamine powder in the dispersion lies between 1 and 80 wt. %.
5 . Dispersion according to claim 4 , wherein the liquid contains water or a polyol.
6 . Dispersion of an aminoplast resin according to claim 1 , wherein the aminoplast resin is a melamine-formaldehyde or melamine-urea-formaldehyde resin, and wherein the liquid contains water or an aminoplast resin.
7 . Method for preparing a dispersion according to claim 1 , comprising the step of bringing a liquid first phase and a second phase together, whereby a dispersant comprising a styrene-maleic anhydride copolymer is added prior to, during or subsequent to the bringing of the two phases together whereby the dispersion is formed, wherein the liquid first phase is the continuous phase and wherein the second phase contains melamine powder and/or an aminoplast resin.
8 . Use of the dispersion according to claim 1 , in adhesive compositions, coatings or laminates.