Method of forming a fiberboard containing a fire-retardant hydrated borate and product thereof

Claim 2

A FIBERBOARD COMPRISING ESSENTIALLY A COMBUSTIBLE FIBER CONTENT AND A FIRE-RETARDANT PARTICULATE CONTENT OF HYDRATED BORATE SALT HAVING THE GENERAL FORMULA

Claim 3

IN A METHOD OF FORMING A RIGID POROUS FIRE-RETARDANT BOARD COMPRISING FORMING A SLURRY OF COMBUSTIBLE VEGETABLE FIBERS AND AN EXCESS OF A RETAINABLE FIRE-RETARDANT QUANTITY RELATIVE TO SAID FIBERS OF FINELY DIVIDED PARTICLES OF A COMPOSITION OF BORON OXIDE, DEWATERING SAID SLURRY TO FORM A MAT, AND DRYING SAID MAT TO A RIGID POROUS BOARD, THE IMPROVEMENT WHEREIN SAID COMPOSITION IS SUBSTANTIALLY INSOLUBLE IN WATER DURING THE FORMATION OF THE SLURRY AND THE DEWATERING AND DRYING THEREOF, AND CONTAINS HYDRATING WATER OF CONSTITUTION RESISTANT TO LOSS DURING SAID DRYING OF THE MAT.

Claim 4

IN A METHOD OF FORMING A RIGID POROUS FIRE-RETARDANT BOARD COMPRISING FORMING A SLURRY OF COMBUSTIBLE VEGETABLE FIBERS AND AN EXCESS OF A RETAINABLE FIRE-RETARDANT QUANTITY RELATIVE TO SAID FIBERS OF FINELY DIVIDED PARTICLES OF A COMPOSITION OF BORON OXIDE, DEWATERING SAID SLURRY TO FORM A MAT, AND DRYING SAID MAT TO A RIGID POROUS BOARD, THE IMPROVEMENT WHEREIN SAID COMPOSITION IS SUBSTANTIALLY INSOLUBLE IN WATER DURING THE FORMATION OF THE SLURRY AND THE DEWATERING AND DRYING THEREOF, AND CONTAINS HYDRATING WATER OF CONSTITUTION RESISTANT TO LOSS DURING SAID DRYING OF THE MAT.