GYPSUM-CONTAINING PRODUCT AND METHOD FOR PRODUCING SAME
0 Assignments
0 Petitions
Accused Products
Abstract
The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.
43 Citations
71 Claims
-
1-51. -51. (canceled)
-
52. A method for producing a set gypsum-containing product comprising forming a mixture of calcined gypsum, water, an accelerator, and one or more enhancing materials chosen from the group consisting of:
- sodium trimetaphosphate, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, aluminum trimetaphosphate, sodium acid pyrophosphate, ammonium polyphosphate having 1000-3000 repeating phosphate units, and acids, salts, or the anionic portions thereof, and
maintaining the mixture under conditions sufficient for the calcined gypsum to form an interlocking matrix of set gypsum, the enhancing material or materials having been included in the mixture in an amount such that the set gypsum-containing product has greater resistance to permanent deformation than it would have if the enhancing material had not been included in the mixture, such that when the mixture is cast in the form of ½
inch gypsum board, said board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board,the accelerator having been included in an amount such that the set gypsum-containing product has greater strength than it would have if the accelerator had not been included in the mixture. - View Dependent Claims (53, 54, 55, 56, 57, 58)
- sodium trimetaphosphate, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, aluminum trimetaphosphate, sodium acid pyrophosphate, ammonium polyphosphate having 1000-3000 repeating phosphate units, and acids, salts, or the anionic portions thereof, and
-
59. A gypsum board comprising a core of material sandwiched between cover sheets, wherein the core comprises an interlocking matrix of set gypsum, and the board has been prepared by a method comprising:
-
forming or depositing a mixture between the cover sheets, wherein the mixture comprises a calcined gypsum, water, an accelerator, and one or more enhancing materials chosen from the group consisting of;
sodium trimetaphosphate, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, aluminum trimetaphosphate, sodium acid pyrophosphate, ammonium polyphosphate having 1000-3000 repeating phosphate units, and acids, salts, or the anionic portions thereof, andmaintaining the mixture under conditions sufficient for the calcined gypsum to form the interlocking matrix of set gypsum, the enhancing material or materials having been included in the mixture in an amount such that the gypsum board has greater sag resistance than it would have if the enhancing material had not been included in the mixture, said board having a sag resistance as determined according to ASTM C473-95 of less than about 0.1 inch per two foot length of said board, the accelerator having been included in an amount such that the gypsum board has greater strength than it would have if the accelerator had not been included in the mixture. - View Dependent Claims (60, 61, 62, 63, 64, 65, 66, 67, 68)
-
-
69. A method for producing a set gypsum-containing product comprising:
-
forming a mixture of a calcined gypsum water, and one or more enhancing materials chosen from the group consisting of;
sodium trimetaphosphate, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, aluminum trimetaphosphate, sodium acid pyrophosphate, ammonium polyphosphate having 1000-3000 repeating phosphate units, and acids, salts, or the anionic portions thereof, andmaintaining the mixture under conditions sufficient for the calcined gypsum to form a set gypsum material, the enhancing material or materials having been included in the mixture in an amount such that the set gypsum formed has greater resistance to permanent deformation than it would have if the enhancing material had not been included in the mixture, such that when the mixture is cast in the form of ½
inch gypsum board, said board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board. - View Dependent Claims (70, 71)
-
Specification