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US 7,745,357 B2Granted
Use of pre-coated mat for preparing gypsum board
AssigneeGeorgia-Pacific Gypsum LLC
InventorsRussell Smith, Brian Randall
Life of this patent
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Abstract
A gypsum board which comprises a set gypsum core sandwiched between and faced with fibrous mats, wherein a free surface of one of said mats is pre-coated with a combination of a mineral pigment, optionally an inorganic adhesive binder and an organic binder, preferably a hydrophobic, UV resistant polymer latex adhesive binder applied to said surface as an aqueous coating composition, said aqueous coating composition upon drying and setting providing a pre-coated mat satisfying certain morphology requirements.
Claims8
A gypsum board comprising:
- a gypsum core having a main portion and a second portion, the second portion being more dense than the main portion;
- a fiber mat comprising a first side and second side opposite the first side, the second side is bonded to the second portion of the gypsum core such that a tensile strength of the bond is at least 16 pounds per square inch;
- and
- a coating penetrating the fiber mat from the first side into the fiber mat to a depth of about 30 percent to about 50 percent of the thickness of the fiber mat, the coating comprises a mineral pigment and an organic binder, wherein the organic binder comprises at least about 1 percent and no more than 17 percent by weight and the mineral pigment has a particle size such that at least 95 percent by weight of the mineral pigment particles pass through a 100 mesh wire screen, with at least 75 percent of the particles by number being greater than 5 microns.
1 more element
A gypsum board comprising:
- a gypsum core having a main portion and a second portion, the second portion being more dense than the main portion;
- a first fiber mat comprising a first side and second side opposite the first side, the second side is bonded to the second portion of the gypsum core such that a tensile strength of the bond is at least 16 pounds per square inch;
- a first coating penetrating the first fiber mat from the first side into the fiber mat to a depth of about 30 percent to about 50 percent of the thickness of the fiber mat,
- a second fiber mat comprising a first side and second side opposite the first side, the second side is bonded to the main portion of the gypsum core;
- a second coating penetrating the second fiber mat from the first side into the fiber mat to a depth of about 30 percent to about 50 percent of the thickness of the fiber mat;
- wherein both the first fiber mat and the second fiber mat each comprise glass fibers nominally about 10 to 16 microns in diameter and about one-quarter (¼) to about one (1) inch in length, the first fiber mat in the absence of coating has a basis weight of 1 to 3 pounds per 100 square feet;
- and
- wherein both the first coating and the second coating each comprise a mineral pigment and an organic binder, wherein the organic binder comprises at least about 1 percent and no more than 17 percent by weight and the mineral pigment has a particle size such that at least 95 percent by weight of the mineral pigment particles pass through a 100 mesh wire screen, with at least 75 percent of the particles by number being greater than 5 microns.
5 more elements
A gypsum board comprising:
- a gypsum core having a main portion and a second portion, the second portion being more dense than the main portion;
- a fiber mat comprising a first side and second side opposite the first side, the second side is bonded to the second portion of the gypsum core such that a tensile strength of the bond is at least 16 pounds per square inch;
- and
- a coating penetrating the fiber mat from the first side into the fiber mat to a depth of about 30 percent to about 50 percent of the thickness of the fiber mat, the coating comprises a mineral pigment and an organic binder, wherein the organic binder comprises at least about 1 percent and no more than 17 percent by weight and the mineral pigment has a particle size such that at least 75 percent of the particles by number are greater than 5 microns.
1 more element
Dependencies are inferred from the claim text.