US 9,993,863 B2  34  33  (S-3) optionally adjustment of the desired pH value with  an inorganic base,  (S-4) addition of one or a plurality of compounds that can  react with any formaldehyde still present  (S-5) preheating of the reaction mixture resulting from the  preceding steps to a temperature in the range from 10  to 50°  C.  (S-6) optionally addition of further constituents.  26.  Method according to claim  23,  wherein the total  amount offurfuryl alcohol used is at least 50 wt.% wherein 10  the percentages by weight are relative to the total weight of  the resultant mixture.  28.  Kit, comprising  as a first component, a mixture according to claim  1,  as a second component, an aqueous solution of an acid,  C.  *  *  *  *  *  5  C., wherein the reaction mixture comprises a content of free  formaldehyde of max. 0.4 wt. %, and wherein the percent› ages by weight are relative to the total weight of the reaction  mixture; wherein curing preferably takes place at a tempera- ture below 60°  C. 