GB996662A - Aminoplast resins - Google Patents

Abstract

Aminoplast resins are prepared by treating with an aldehyde a material obtained by heating urea, to which may be added up to 50% of its weight of other aminoplast-forming substances, e.g. urea, dicyanodiamide, guanidine, dicyanodiamidine, alkyl- or aryl-guanimines, and thiourea, before or during the heating, at 130-200 DEG C. until 1 part by weight of the product requires between 1 and 15 parts by volume of normal sodium hydroxide for complete solution. The condensation with aldehyde may be performed in aqueous solution, or without water, and in the presence, if desired, of mono- or polyvalent amines, alkanolamines or N-substituted s-triazones. The alkylol groups formed may be etherified with mono- or poly-valent alcohols. The melt loses at least 14% of its initial weight and contains not more than 50% urea, together with biuret, melamine, ammeline, ammelide, cyanuric acid, and cyanuric acid triureide. The proportions may be modified by adding a water-absorbing agent, e.g. silica gel, anhydrous Na<\>z2SO4, or ZnCl2. The products are miscible with other aminoplasts, from e.g. melamine, guanamine, s-triazones and ethyleneurea and with alkyd resins. Uses.-Textile finishing, impregnation of paper or sheets for laminates, adhesives, binding agents.ALSO:Wet tear strength is imparted to paper by aminoplast resins prepared from aldehydes and the product from healing urea at 130-200 DEG C. until 1 part by weight of the product requires 1 to 15 parts of 1 N sodium hydroxide for solution. Other aminoplast-forming substances may be added before or during heating, and the aminoplast product may be mixed with other aminoplast resins, or with alkyol resins, and may be etherified (see Division C3).