Formaldehyde-free molding based on renewable raw materials

Abstract

A formaldehyde-free molding of particulate and/or fibrous substrates is provided.

1 . A molding, comprising, as active constituents:
 a) a polymer A which is composed of from 5 to 100% by weight of an ethylenically unsaturated carboxylic anhydride or of an ethylenically unsaturated dicarboxylic acid whose carboxyl groups can form an anhydride group, incorporated in the form of polymerized units, and   b) an alkanolamine B which has at least 2 hydroxyl groups,   wherein the molding is obtained by a process comprising:   impregnating a particulate and/or fibrous substrate with a formaldehyde-free; aqueous binder,   shaping the impregnated particulate and/or fibrous substrates to give a molding and   subjecting the molding thus obtained to a thermal treatment,   wherein   from 0.01 to 5% by weight of an organic polyamine compound C, based on the total amount of the particulate and/or fibrous substrates, is applied to the particulate and/or fibrous substrates before the impregnation with the formaldehyde-free, aqueous binder,   the organic polyamine compound C has a weight average molecular weight Mw of ≧1000 g/mol and has in total at least 5 primary and/or secondary amino functions.   
     
     
         2 . The molding according to  claim 1 , wherein the organic polyamine compound C is applied in the form of an aqueous solution. 
     
     
         3 . The molding according to  claim 1 , wherein the polyamine compound C is selected from the group consisting of polyethyleneimines, polyallylamines, polyvinylamines, partly hydrolyzed polyvinylformamides and/or polyamidoamines. 
     
     
         4 . The molding according to  claim 1 , wherein the thermal treatment step is effected at a temperature of ≧110 and ≦170° C. 
     
     
         5 . The molding according to  claim 1 , wherein the fibrous substrates are mechanically strengthened. 
     
     
         6 . The molding according to  claim 1 , wherein a content of the polymer A and a content of the alkanolamine B are in a ratio to one another such that the molar ratio of carboxyl groups of the polymer A to the hydroxyl groups of the alkanolamine B is from 20:1 to 1:1. 
     
     
         7 . The molding according to  claim 1 , wherein an amount of binder, formed from polymer A and alkanolamine B, calculated as solid, is from 5 to 40% by weight, based on the weight of the particulate and/or fibrous substrate. 
     
     
         8 . The molding according to  claim 1 , wherein the particulate and/or fibrous substrates comprise at least one material selected from the group consisting of sisal fibers, jute fibers, flax fibers, coconut fibers, banana fibers, hemp fibers, kenaf fibers, and slivers, chips, granules and dusts of wood and slivers, chips, granules and dusts of cork.