Construction board and method of making same

Claim 1

A FIBROUS BOARD COMPRISING A MASS OF RANDOMLY AND INITIALLY LOOSELY INTERLACED FIBERS BONDED FIRMLY TOGETHER BY A BONDING MEDIUM COMPRISING THE DRIED GELLED RESIDUE OF A HARDENABLE AQUEOUS MIXTURE COMPRISING DISPERSED ELASTIC RUBBERY COMPOSITION SELECTION FROM THE GROUP CONSISTING OF RUBBERY COPOLYMER OF BUTADINE AND STYRENE IN ADMIXTURE WITH VULCANIZING INGREDIENTS, RUBBERY COPOLYMER OF BUTADIENE AND ACRYLONITRILE IN ADMIXTURE WITH VULCANIZING INGREDIENTS, RUBBERY COPOLYMER OF ISOPRENE AND STYRENE IN ADMIXTURE WITH VULCANIZING INGREDIENTS, AND RUBBERY POLYMERIZED CHLOROPRENE, AND DISSOLVED PARTIALLY CONDENSED RESIN OBTAINED BY THE PARTIAL CONDENSATION OF A POLYHYDRIC PHENOL HAVING HYDROXYL GROUPS IN THE 1- AND 3-POSITIONS AND AN ALDEHYDE AND CAPABLE OF SETTING IN THE AQUEOUS CONDITION TO A FRIABLE SOLID GEL AND CAPABLE OF BENG CONVERTED UPON REMOVAL OF WATER TO A SUBSTANTIALLY INFUSIBLE, SUBSTANTIALLY INSOLUBLE STATE, SAID MIXTURE CONTAINING SAID RUBBERY POLYMER AND SAID RESIN IN SUCH RELATIVE PROPORTIONS THAT THE POLYHYDRIC PHENOL CONTENT OF SAID RESINRANGES FROM 3.8 TO 16.8% BY WEIGHT BASED ON THE WEIGHT OF SAID RUBBERY POLYMER AND CONTAINING AT LEAST 30% BY WEIGHT OF SAID RUBBERY POLYMER AND SAID RESIN.