# US 6,409,824 B1 · Gypsum compositions with enhanced resistance to permanent deformation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,409,824 B1 - Document ID: US6409824B1 - Status: Granted - Kind: B1 - Application number: 09/557,721 - Filed: 2000-04-25 - Granted: 2002-06-25 - Earliest claimed: 2000-04-25 - Assignees: United States Gypsum Company - Inventors: Srinivas Veeramasuneni; Qiang Yu; Michael P. Shake - Web page: https://patentgrep.com/patent/US6409824B1 ## CPC - C04B 20/107: {Acids or salts thereof} - C04B 24/003: {Phosphorus-containing compounds} - C04B 28/14: containing calcium sulfate cements {(gypsum-paper plates E04C)} - C04B 40/0042: {Powdery mixtures} - C04B 2111/00094: {Sag-resistant materials} - C04B 2111/34: Non-shrinking or non-cracking materials - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract A set gypsum-containing composition is disclosed. In one aspect, the set gypsum-containing composition includes an interlocking matrix of the set gypsum formed from at least calcined gypsum, water, and an enhancing material. The enhancing material can be selected from (i) an organic polyphosphonic compound, or a mixture thereof; (ii) a borate selected from ulexite colemanite, or a mixture thereof; or a mixture of (i) and (ii). In another aspect, the set gypsum-containing composition is treated with an enhancing material which can be selected from (i) an organic phosphonic compound or a mixture thereof; (ii) a borate selected from ulexite, colemanite, or a mixture thereof; (iii) a carboxylic compound or a mixture thereof; or a mixture of (i), (ii) and/or (iii). ## Claims ### Claim 1 A set gypsum-containing composition comprising an interlocking matrix of the set gypsum formed from at least calcined gypsum, water, and an enhancing material comprising a borate comprising ulexite, colemanite, or a mixture of ulexite and colemanite. ### Claim 2 (depends on 1) The composition of claim 1, wherein said composition is further formed from a second enhancing material comprising a polycarboxylic compound or a mixture of polycarboxylic compounds. ### Claim 3 (depends on 1) The composition of claim 1, wherein said composition is further formed from a third enhancing material comprising a polyphosphate compound or a mixture of polyphosphate compounds. ### Claim 4 (depends on 2) The composition of claim 2, wherein said composition is further formed from a third enhancing material comprising a polyphosphate compound or a mixture of polyphosphate compounds. ### Claim 5 (depends on 2) The composition of claim 2, wherein said composition further is formed from an accelerator. ### Claim 6 (depends on 1) The composition of claim 1, wherein said composition further is formed from an accelerator. ### Claim 7 (depends on 6) The composition of claim 6, wherein at least a portion of the borate is carried on the accelerator. ### Claim 8 (depends on 7) The composition of claim 7, wherein only a portion of the borate is carried on the accelerator. ### Claim 9 (depends on 1) The composition of claim 1, wherein the set gypsum is formed from about 0.01 wt. % to about 5 wt. % of enhancing material, based on the weight of the calcined gypsum. ### Claim 10 (depends on 7) The composition of claim 7, wherein said borate is ulexite. ### Claim 11 (depends on 1) The composition of claim 1, wherein said composition is further formed from a second enhancing material comprising an organic polyphosphonic compound. ### Claim 12 (depends on 11) The composition of claim 11, wherein said organic polyphosphonic compound is aminotri (methylene-phosphonic acid), aminotri (methylene-phosphonic acid) pentasodium salt, 1-hydroxyethylidene-1,1-diphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid tetrasodium salt, diethylenetriamine penta(methylene phosphonic acid) pentasodium salt, diethylenetriamine penta(methylene phosphonic acid) trisodium salt, hexamethylene diamine tetra(methylene phosphonic acid), or hexamethylene diamine tetra(methylene phosphonic acid) potassium salt. ### Claim 13 (depends on 1) The composition of claim 1, wherein said borate is ulexite. ### Claim 14 (depends on 1) The composition of claim 1, wherein said borate is colemanite. ### Claim 15 (depends on 2) The composition of claim 2, wherein said polycarboxylic compound has a molecular weight of from about 100,000 daltons to about 1 million daltons. ### Claim 16 (depends on 2) The composition of claim 2, wherein said polycarboxylic compound has a molecular weight of from about 400,000 daltons to about 600,000 daltons. ### Claim 17 (depends on 2) The composition of claim 2, wherein said polycarboxylic compound is selected from the group consisting of polyacrylates, polyethacrylates, and polymethacrylates. ### Claim 18 (depends on 1) The composition of claim 1, wherein said polycarboxylic compound is a polyacrylate. ### Claim 19 (depends on 3) The composition of claim 3, wherein said polyphosphate compound is selected from the group consisting of a trimetaphosphate compound, sodium hexametaphosphate having 6-27 repeating phosphate units, ammonium polyphosphate, tetrapotassium pyrophosphate, sodium tripolyphosphate, tetrasodium pyrophosphate, sodium acid pyrophosphate, and polyphosphoric acid having 2 or more repeating phosphoric acid units. ### Claim 20 (depends on 3) The composition of claim 3, wherein said third enhancing material is a trimetaphosphate compound. ### Claim 21 (depends on 3) The composition of claim 3, wherein said third enhancing material is ammonium polyphosphate. ### Claim 22 (depends on 4) The composition of claim 4, wherein said polyphosphate compound is selected from the group consisting of a trimetaphosphate compound, sodium hexametaphosphate having 6-27 repeating phosphate units, ammonium polyphosphate, tetrapotassium pyrophosphate, trisodium dipotassium tripolyphosphate, sodium tripolyphosphate, tetrasodium pryophosphate, sodium acid pyrophosphate, and polyphosphoric acid having 2 or more repeating phosphoric acid units. ### Claim 23 (depends on 4) The composition of claim 4, wherein said third enhancing material is a trimetaphosphate compound. ### Claim 24 (depends on 4) The composition of claim 4, wherein said third enhancing material is ammonium polyphosphate. ### Claim 25 A gypsum board comprising an interlocking matrix of set gypsum formed from at least calcined gypsum, water, and an enhancing material comprising: (i) an organic polyphosphonic compound or a mixture of polyphosphonic compounds; or (ii) a borate comprising ulexite, colemanite, or a mixture of ulexite and colemanite; or a mixture of (i) and (ii). ### Claim 26 (depends on 25) The gypsum board of claim 25, wherein said gypsum 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. ### Claim 27 (depends on 25) The gypsum board of claim 25, wherein said gypsum board has a shrinkage of less than about 0.02 inch per four foot width and less than about 0.05 inch per twelve foot length. ### Claim 28 (depends on 25) The gypsum board of claim 25, wherein the composition is further formed from an accelerator and wherein at least a portion of the borate is carried on an accelerator. ### Claim 29 (depends on 28) The gypsum board of claim 28, wherein said gypsum 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. ### Claim 30 A set gypsum-containing composition comprising an interlocking matrix of set gypsum formed from at least calcined gypsum, water, and an enhancing material comprising: (i) a polycarboxylic compound or a mixture of polycarboxylic compounds; and (ii) a polyphosphate compound or a mixture of polyphosphate compounds. ### Claim 31 A set gypsum-containing composition comprising an interlocking matrix of set gypsum wherein said set gypsum has been treated with a mixture of a liquid and an enhancing material comprising: (i) an organic phosphonic compound or a mixture of organic phosphonic compounds; (ii) a borate comprising ulexite, colemanite, or a mixture of ulexite and colemanite; or (iii) a carboxylic compound or a mixture of carboxylic compounds; or a mixture of any combination of (i), (ii), and (iii). ### Claim 32 (depends on 31) The set gypsum-containing composition of claim 31, wherein said composition further is treated with a second enhancing material comprising a phosphate compound or a mixture of phosphate compounds. ### Claim 33 (depends on 31) The composition of claim 31, wherein said enhancing material is an organic phosphonic compound. ### Claim 34 (depends on 33) The composition of claim 33, wherein said organic phosphonic compound is aminotri (methylene-phosphonic acid), aminotri (methylene-phosphonic acid) pentasodium salt, 1-hydroxyethylidene-1,1-diphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid tetrasodium salt, diethylenetriamine penta(methylene phosphonic acid) pentasodium salt, diethylenetriamine penta(methylene phosphonic acid) trisodium salt, hexamethylene diamine tetra(methylene phosphonic acid), or hexamethylene diamine tetra(methylene phosphonic acid) potassium salt. ### Claim 35 (depends on 31) The composition of claim 31, wherein said borate is ulexite. ### Claim 36 (depends on 31) The composition of claim 31, wherein said borate is colemanite. ### Claim 37 (depends on 31) The composition of claim 31, wherein said carboxylic compound is a polycarboxylic compound. ### Claim 38 (depends on 37) The composition of claim 37, wherein said polycarboxylic compound has a molecular weight of from about 200 daltons to about 1 million daltons. ### Claim 39 (depends on 31) The composition of claim 31, wherein said carboxylic compound is selected from the group consisting of polyacrylates, polyethacrylates, polymethacrylates, and citrates. ### Claim 40 (depends on 37) The composition of claim 37, wherein said polycarboxylic compound is a polyacrylate. ### Claim 41 (depends on 32) The composition of claim 32, wherein said second enhancing material is a polyphosphate compound. ### Claim 42 (depends on 31) A gypsum board comprising the composition of claim 31. ### Claim 43 (depends on 42) The gypsum board of claim 42, wherein said gypsum 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. ### Claim 44 (depends on 42) The gypsum board of claim 42, wherein said gypsum board has a shrinkage of less than about 0.02 inch per four foot width and less than about 0.05 inch per twelve foot length. ### Claim 45 An accelerator for an aqueous calcined gypsum composition comprising a borate selected from the group consisting of ulexite, colemanite and a mixture of ulexite and colemanite, and an accelerator material. ### Claim 46 (depends on 45) The accelerator of claim 45, wherein the accelerator material is calcium sulfate dihydrate. ### Claim 47 (depends on 45) The accelerator of claim 45, wherein the borate and the accelerator material are provided in a milled mixture. ### Claim 48 (depends on 47) The accelerator of claim 47, wherein the milled mixture has a median particle size of less than about 5 μm. ### Claim 49 (depends on 47) The accelerator of claim 47, wherein the milled mixture has a surface area of at least about 7,000 cm2/gram. ### Claim 50 A set gypsum-containing composition comprising an interlocking matrix of set gypsum formed from at least calcined gypsum, water, and an enhancing material comprising: (i) a polycarboxylic compound or a mixture of polycarboxylic compounds; and (ii) an organic polyphosphonic compound or a mixture of organic polyphosphonic compounds. ### Claim 51 (depends on 50) The composition of claim 50, wherein said polycarboxylic compound has a molecular weight of from about 100,000 daltons to about 1 million daltons. ### Claim 52 (depends on 50) The composition of claim 50, wherein said polycarboxylic compound has a molecular weight of from about 400,000 daltons to about 600,000 daltons. ### Claim 53 (depends on 50) The composition of claim 50, wherein said polycarboxylic compound is selected from the group consisting of polyacrylates, polyethacrylates, and polymethacrylates.