Fibrous mat-faced gypsum board in exterior and interior finishing systems for buildings
AssigneeGeorgia-Pacific Corporation
InventorsCharles W. Lehnert, Brian G. Randall
Life of this patent
Estimating the term…
Abstract
Gypsum-containing boards, uses for these boards, and methods for making them are provided. The board includes a set gypsum core having a fibrous glass at disposed thereon. The core includes a water-resistant additive in at least a minimum amount sufficient to impart to the board an ASTM C-473 water absorption value of less than about 10%. This additive includes organohydrogenpolysiloxane resin added with a portion of the mixing water, or otherwise added in neat form to the process for preparing the slurry.
Claims12
A gypsum-containing board comprising a set gypsum core having a fibrous glass mat disposed thereon, said core including a water-resistant additive in at least a minimum amount sufficient to impart to the board an ASTM C-473 water absorption value of less than about 10%, said additive comprising an organohydrogenpolysiloxane resin added with a portion of the mixing water used to prepare said core.
A gypsum-containing board having an ASTM C-473 water absorption value of less than 5%, said board comprising a core of set gypsum sandwiched between two sheets of porous glass mat, said sheets comprising randomly distributed glass fibers bonded by adhesive material, said core including organohydrogenpolysiloxane resin added with a portion of the mixing water used to prepare said core in an amount sufficient to impart to the board improved water resistance.
The method of making a gypsum-containing board having an ASTM C-473 water absorption value of less than 10%, comprising:
- forming an aqueous gypsum slurry of gypsum, water and at least a minimum amount of an organohydrogenpolysiloxane resin which is sufficient to impart water resistance to said board;
- disposing said slurry onto a moving fibrous glass mat;
- cutting said board into individual lengths;
- and
- drying said board.
Dependencies are inferred from the claim text.