method of manufacturing resinous papers, resinous papers, and their use as resinous preform blanks

Abstract

The present invention relates to resinous papers, their use as resinous preform blanks and to a method of manufacturing resinous papers. The resinous paper or preform blank is made by preparing an aqueous fiber suspension having a consistency between 0,5-8%, preparing an aqueous dispersion of a thermosetting resin, mixing the aqueous dispersion of the thermosetting resin into the aqueous fiber suspension, preparing an aqueous dispersion of an agent for fixing the thermosetting resin on the fibers of the fiber suspension, mixing the aqueous dispersion of the fixing agent into the aqueous fiber suspension, adjusting a pH value of the aqueous fiber suspension to below 5, transferring the aqueous fiber suspension to a paper machine, dewatering the fiber suspension for the formation of paper, and drying the paper to a volatile content of 5% to 10%.

1 . A method of manufacturing resinous paper, comprising the steps of:
 preparing an aqueous fiber suspension having a consistency between 0,5-8%,   preparing an aqueous dispersion of a thermosetting resin   mixing the aqueous dispersion of the thermosetting resin into the aqueous fiber suspension,   preparing an aqueous dispersion of an agent for fixing the thermosetting resin on the fibers of the fiber suspension,   mixing the aqueous dispersion of the fixing agent into the aqueous fiber suspension,   adjusting a pH value of the aqueous fiber suspension to below 5,   transferring the aqueous fiber suspension to a paper machine,   dewatering the fiber suspension for the formation of paper,   drying the paper to a volatile content of 5% to 10%.   
     
     
         2 . The method according to  claim 1 , characterized in that the content of the thermosetting resin in the paper is 30 weight % to 50 weight % solids content in the paper. 
     
     
         3 . The method according to at least one of the preceding claims, characterized in that the thermosetting resin is water-dispersible or water-soluble. 
     
     
         4 . The method according to at least one of the preceding claims, characterized in using phenolic resins, melamine resins or urea resins, or mixtures of these resins as the thermosetting resin. 
     
     
         5 . The method according to  claim 1 , characterized in using cationically, anionically, non-ionically and/or bi-ionically acting substances as the fixing agent for fixing the resin on the fibers. 
     
     
         6 . The method according to at least one of the preceding claims, characterized in adding fire-protection additives to the suspension. 
     
     
         7 . The method according to  claim 6 , characterized in adding one or more of aluminum-trihydrate, chloroprene-latex and/or mixtures of carbamides with organic sulphonic acids and inorganic salts as fire-protection additives to the suspension. 
     
     
         8 . The method according to at least one of the preceding claims, characterized in manufacturing a paper having a grammage from 140 g/m 2  to 1000 g/m 2 . 
     
     
         9 . The method according to at least one of the preceding claims, characterized in drying the paper under heat. 
     
     
         10 . A resinous paper containing fibers coated with a thermosetting resin and manufactured by the method according to at least one of  claims 1  to  9 . 
     
     
         11 . The resinous paper according to  claim 10 , characterized in that fire-protection additives are added to it and it is classified in fire-protection class B1 (B1 fire rate). 
     
     
         12 . The resinous paper according to  claim 10 , characterized in having fibers arranged such that they intersect at contact points and that at least at some of the contact points the fibers are coated with thermosetting resin. 
     
     
         13 . The resinous paper according to  claim 10 , characterized in that it has a weight of up to 300 g/m 2 . 
     
     
         14 . The resinous paper according to  claim 10 , characterized in that it has a weight of more than 400 g/m 2 , preferably more than 500 g/m 2 , particularly preferably more than 700 g/m 2 , advantageously more than 900 g/m 2 , especially advantageously up to 1000 g/m 2 . 
     
     
         15 . The resinous paper according to at least one of  claims 10  to  14 , characterized in that it has a thermosetting resin content of 30 weight % to 50 weight % based on the solid content of the paper. 
     
     
         16 . The resinous paper according to at least one of  claims 10  to  15 , characterized in that it is a singe-layer or a multi-layer paper. 
     
     
         17 . The resinous paper according to  claim 16 , characterized in that it is a multi-layer paper with a grammage of more than 400 g/m 2  and with a thermosetting resin content of 30 weight % to 50 weight % based on the solid content of the paper. 
     
     
         18 . The resinous paper according to at least one of  claims 13  to  18 , characterized in that it is a coated or an uncoated paper. 
     
     
         19 . Use of the resinous paper according to at least one of  claims 10  to  18  as a resinous preform blank comprising fibers coated with a thermosetting resin.