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| 국가/구분 | United States(US) Patent 등록 |
|---|---|
| 국제특허분류(IPC7판) |
|
| 출원번호 | US-0906479 (2007-10-02) |
| 등록번호 | US-9840066 (2017-12-12) |
| 발명자 / 주소 |
|
| 출원인 / 주소 |
|
| 대리인 / 주소 |
|
| 인용정보 | 피인용 횟수 : 0 인용 특허 : 229 |
This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.
1. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the air void size having greatest frequency is a diameter of about 1
1. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the air void size having greatest frequency is a diameter of about 100 microns or less, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average wall thickness and air voids measured using scanning electron photomicrograph imaging, and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473; and the board having a density of about 35 pcf or less. 2. The light weight gypsum board of claim 1, wherein the walls have an average thickness of at least about 50 microns to about 200 microns. 3. The light weight gypsum board of claim 1, wherein the walls have an average thickness from about 70 microns to about 120 microns. 4. The light weight gypsum board of claim 1, wherein the walls define: (i) air voids with a size greater than about 100 microns in diameter, (ii) air voids with a size from about 50 microns to about 100 microns in diameter, and (iii) air voids with a size less than about 50 microns in diameter, the sizes measured using scanning electron photomicrograph imaging. 5. The light weight gypsum board of claim 4, wherein the air voids with a size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core. 6. The light weight gypsum board of claim 1, wherein at least a portion of the walls includes reinforced densified wall surfaces. 7. The light weight gypsum board of claim 1, wherein the walls and the air voids are arranged in the set gypsum core such that the board has a nail pull resistance of at least 65 pounds as determined in accordance with ASTM C-473, when the board is about ½ inch thick. 8. The light weight gypsum board of claim 1, wherein the walls and the air voids are arranged in the set gypsum core such that the board has a flexural strength of at least 36 pounds in a machine direction and/or 107 pounds in a cross-machine direction, each determined in accordance with ASTM C-473, when the board is about ½ inch thick. 9. The light weight gypsum board of claim 1, wherein at least one cover sheet comprises multi-ply paper, and the board has a nail pull resistance of at least 65 pounds as determined in accordance with ASTM C-473, when the board is about ½ inch thick. 10. The light weight gypsum board of claim 1, wherein the board exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick. 11. The light weight gypsum board of claim 10, wherein at least one of the cover sheets comprises paper having a weight of at least about 45 lb/MSF. 12. The light weight gypsum board of claim 1, wherein the board has a dry weight of from about 1000 lb/MSF to about 1300 lb/MSF at a board thickness of about ½ inch. 13. The light weight gypsum board of claim 1, wherein the board has a density of from about 24 pcf to about 31 pcf. 14. The light weight gypsum board of claim 1, wherein the set gypsum core is formed from a slurry comprising water, stucco, and an amount of a starch effective to increase the core hardness of the set gypsum core relative to a set gypsum core formed from the slurry without the starch. 15. The light weight gypsum board of claim 14, wherein the starch comprises a pregelatinized starch in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 16. The light weight gypsum board of claim 1, wherein the set gypsum core is formed from a slurry comprising water, stucco, foam, and dispersant. 17. The light weight gypsum board of claim 16, wherein the dispersant comprises a naphthalenesulfonate dispersant. 18. The light weight gypsum board of claim 17, wherein the slurry further comprises a pregelatinized starch, the naphthalenesulfonate dispersant being in an amount from about 0.1% to about 3% by weight based on the weight of the stucco, and the pregelatinized starch being in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 19. The light weight gypsum board of claim 18, wherein the slurry further comprises a water-soluble polyphosphate-containing compound. 20. The light weight gypsum board of claim 1, wherein the set gypsum core is formed from a slurry comprising water, stucco, and a water-soluble polyphosphate-containing compound. 21. The light weight gypsum board of claim 20, wherein the water-soluble polyphosphate-containing compound is in an amount from about 0.1% to about 0.4% by weight based on the weight of the stucco. 22. The light weight gypsum board of claim 1, wherein the set gypsum core is formed from a slurry comprising water, stucco, and soap foam, and the slurry has a wet compressive strength of at least about 320 psi when the slurry is prepared without substantial soap foam and east as a two-inch cube. 23. The light weight gypsum hoard of claim 1, wherein the set gypsum core is formed from a slurry comprising water, stucco, and soap foam, and the slurry has a wet compressive strength of at least about 340 psi when the slurry is prepared without substantial soap foam with a water to stucco weight ratio of 1.2 and cast as a two-inch cube. 24. The light weight gypsum board of claim 1, wherein the set gypsum core comprises glass fiber. 25. The light weight gypsum board of claim 1, wherein at least one of the cover sheets comprises a fibrous mat, a nonwoven glass fiber mat, a woven glass mat, or a non-cellulosic fabric. 26. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the air void size having greatest frequency is a diameter of about 100 microns or less, the average wall thickness and air voids measured using scanning electron photomicrograph imaging, and the gypsum crystal matrix formed such that the board exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick; and the board having a density of about 35 pcf or less. 27. The light weight gypsum board of claim 26, wherein the walls have an average thickness of at least about 50 microns to about 200 microns. 28. The light weight gypsum board of claim 26, wherein the walls have an average thickness from about 70 microns to about 120 microns. 29. The light weight gypsum board of claim 26, wherein the walls and the air voids are arranged in the set gypsum core such that the core hardness is at least about 11 pounds as determined in accordance with ASTM C-473. 30. The light weight gypsum board of claim 26, wherein some of the air voids have a size from about 50 microns to about 100 microns in diameter, some of the air voids have a size greater than about 100 microns in diameter, and the air voids with a pore size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core, the sizes measured using scanning electron photomicrograph imaging. 31. The light weight gypsum board of claim 30, wherein the air voids with a size greater than about 50 microns in diameter comprise at least about 50% of the total void volume of the set gypsum core. 32. The light weight gypsum board of claim 26, wherein the set gypsum core is formed from a slurry comprising water, stucco, and an amount of a starch effective to increase the core hardness of the set gypsum core relative to a set gypsum core formed from the slurry without the starch. 33. The light weight gypsum hoard of claim 32, wherein the slurry further comprises a foam and a dispersant. 34. The light weight gypsum board of claim 33, wherein the dispersant comprises a naphthalenesulfonate dispersant. 35. The light weight gypsum hoard of claim 34, wherein the starch comprises a pregelatinized starch, and the naphthalenesulfonate dispersant is in an amount from about 0.1% to about 3% by weight based on the weight of the stucco, and the pregelatinized starch is in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 36. The light weight gypsum hoard of claim 35, wherein the slurry further comprises a water-soluble polyphosphate-containing compound. 37. The light weight gypsum board of claim 36, wherein the water-soluble polyphosphate-containing compound comprises a trimetaphosphate salt chosen from the group consisting of sodium trimetaphosphate, potassium trimetaphosphate, trimetaphosphate, and ammonium trimetaphosphate in an amount of at least about 0.12% by weight based on the weight of the stucco. 38. The light weight gypsum board of claim 1, wherein the set gypsum core is formed using a water to stucco weight ratio from about 0.7 to about 1.3. 39. The light weight gypsum board of claim 38, wherein the set gypsum core is further formed using pregelatinized starch. 40. The light weight gypsum board of claim 1, wherein the walls define air voids with a size of from about 50 microns to about 300 microns in diameter. 41. The light weight gypsum board of claim 26, wherein the set gypsum core is formed using a water to stucco weight ratio from about 0.7 to about 1.3. 42. The light weight gypsum board of claim 41, wherein the set gypsum core is further formed using pregelatinized starch. 43. The light weight gypsum board of claim 26, wherein the walls define air voids with a size of from about 50 microns to about 300 microns in diameter. 44. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the air void size having greatest frequency is a diameter of about 100 microns or less, the average wall thickness and air voids measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473; and the board having a density of about 35 pcf or less. 45. The light weight gypsum board of claim 44, wherein the walls have an average thickness from about 70 microns to about 120 microns. 46. The light weight gypsum hoard of claim 44, wherein at least a portion of the walls includes reinforced densified wall surfaces. 47. The light weight gypsum board of claim 44, wherein the board has a density of from about 24 pcf to about 31 pcf. 48. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the air void size having greatest frequency is a diameter of about 100 microns or less, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average wall thickness and air voids measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), and the gypsum crystal matrix formed such that the board exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick; and the hoard having a density of about 35 pcf or less. 49. The light weight gypsum board of claim 48, wherein the walls have an average thickness from about 70 microns to about 120 microns. 50. The light weight gypsum board of claim 26, wherein the board has a density of from about 24 pcf to about 31 pcf. 51. The light weight gypsum board of claim 48, wherein the hoard has a density of from about 24 pcf to about 31 pcf. 52. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average air void size being less than about 100 microns in diameter, the average wall thickness and average air void size measured using scanning electron photomicrograph imaging, and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473; and the board having a density of about 35 pcf or less. 53. The light weight gypsum board of claim 52, wherein the average air void size is between about 10 microns in diameter and about 100 microns in diameter. 54. The light weight gypsum board of claim 53, wherein the average air void size is between about 20 microns in diameter and about 100 microns in diameter. 55. The light weight gypsum hoard of claim 54, wherein the average air void size is between about 50 microns in diameter and about 100 microns in diameter. 56. The light weight gypsum board of claim 52, wherein the walls have an average thickness from about 70 microns to about 120 microns. 57. The light weight gypsum board of claim 52, wherein the walls define: (i) air voids with a size greater than about 100 microns in diameter, (ii) air voids with a size from about 50 microns to about 100 microns in diameter, and (iii) air voids with a size less than about 50 microns in diameter, the sizes measured using scanning electron photomicrograph imaging. 58. The light weight gypsum board of claim 57, wherein the air voids with a size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core. 59. The light weight gypsum board of claim 52, wherein the board has a density of from about 24 pcf to about 35 pcf. 60. The light weight gypsum board of claim 59, wherein the board has a density of from about 24 pcf to about 33 pcf. 61. The light weight gypsum board of claim 60, wherein the board has a density of from about 24 pcf to about 31 pcf. 62. The light weight gypsum board of claim 61, wherein the board has a density of from about 27 pcf to about 30 pcf. 63. The light weight gypsum board of claim 52, wherein the set gypsum core is formed using a water to stucco weight ratio from about 0.7 to about 1.3. 64. The light weight gypsum hoard of claim 52, wherein the set gypsum core is formed from a slurry comprising water, stucco, and an amount of a starch effective to increase the core hardness of the set gypsum core relative to a set gypsum core formed from the slurry without the starch. 65. The light weight gypsum board of claim 64, wherein the starch comprises a pregelatinized starch in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 66. The light weight gypsum board of claim 52, wherein the set gypsum core is formed from a slurry comprising water, stucco, foam, and dispersant. 67. The light weight gypsum board of claim 66, wherein the dispersant comprises a naphthalenesulfonate dispersant. 68. The light weight gypsum board of claim 67, wherein the slurry further comprises a pregelatinized starch, the naphthalenesulfonate dispersant being in an amount from about 0.1% to about 3% by weight based on the weight of the stucco, and the pregelatinized starch being in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 69. The light weight gypsum board of claim 68, wherein the slurry further comprises a water-soluble polyphosphate-containing compound. 70. The light weight gypsum board of claim 52, wherein the set gypsum core is formed from a slurry comprising water, stucco, and a water-soluble polyphosphate-containing compound. 71. The light weight gypsum board of claim 70, wherein the water-soluble polyphosphate-containing compound is in an amount from about 0.1% to about 0.4% by weight based on the weight of the stucco. 72. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average air void size being less than about 100 microns in diameter, the average wall thickness and average air void size measured using scanning electron photomicrograph imaging, and the gypsum crystal matrix formed such that the hoard exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick; and the board having a density of about 35 pcf or less. 73. The light weight gypsum board of claim 72, wherein the average air void size is between about 10 microns in diameter and about 100 microns in diameter. 74. The light weight gypsum hoard of claim 73, wherein the average air void size is between about 20 microns in diameter and about 100 microns in diameter. 75. The light weight gypsum board of claim 74, wherein the average air void size is between about 50 microns in diameter and about 100 microns in diameter. 76. The light weight gypsum board of claim 72, wherein the board has a density of from about 24 pcf to about 35 pcf. 77. The light weight gypsum hoard of claim 76, wherein the board has a density of from about 24 pcf to about 33 pcf. 78. The light weight gypsum board of claim 77, wherein the board has a density of from about 24 pcf to about 31 pcf. 79. The light weight gypsum board of claim 78, wherein the board has a density of from about 27 pcf to about 30 pcf. 80. The light weight gypsum board of claim 72, wherein the walls have an average thickness from about 70 microns to about 120 microns. 81. The light weight gypsum board of claim 72, wherein the walls and the air voids are arranged in the set gypsum core such that the core hardness is at least about 11 pounds as determined in accordance with ASTM C-473. 82. The light weight gypsum hoard of claim 72, wherein some of the air voids have a size from about 50 microns to about 100 microns in diameter, some of the air voids have a size greater than about 100 microns in diameter, and the air voids with a size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core, the sizes measured using scanning electron photomicrograph imaging. 83. The light weight gypsum hoard of claim 72, wherein the set gypsum core is formed from a slurry comprising water, stucco, and an amount of a starch effective to increase the core hardness of the set gypsum core relative to a set gypsum core formed from the slurry without the starch. 84. The light weight gypsum hoard of claim 83, wherein the starch is a pregelatinized starch. 85. The light weight gypsum board of claim 83, wherein the slurry further comprises a foam and a dispersant. 86. The light weight gypsum board of claim 85, wherein the dispersant comprises a naphthalenesulfonate dispersant. 87. The light weight gypsum board of claim 86, wherein the starch comprises a pregelatinized starch, and the naphthalenesulfonate dispersant is in an amount from about 0.1% to about 3% by weight based on the weight of the stucco, and the pregelatinized starch is in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 88. The light weight gypsum board of claim 87, wherein the slurry further comprises a water-soluble polyphosphate-containing compound. 89. The light weight gypsum board of claim 88, wherein the water-soluble polyphosphate-containing compound comprises a trimetaphosphate salt chosen from the group consisting of sodium trimetaphosphate, potassium trimetaphosphate, lithium trimetaphosphate, and ammonium trimetaphosphate in an amount of at least about 0.12% by weight based on the weight of the stucco. 90. The light weight gypsum board of claim 72, wherein the set gypsum core is formed using a water to stucco weight ratio from about 0.7 to about 1.3. 91. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average air void size being less than about 100 microns in diameter, the average wall thickness and average air void size measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473; and the board having a density of about 35 pcf or less. 92. The light weight gypsum board of claim 91, wherein the average air void size is between about 10 microns in diameter and about 100 microns in diameter. 93. The light weight gypsum board of claim 91, wherein the walls have an average thickness from about 70 microns to about 120 microns. 94. The light weight gypsum board of claim 91, wherein at least a portion of the walls includes reinforced densified wall surfaces. 95. The light weight gypsum board of claim 91, wherein the board has a density of from about 24 pcf to about 35 pcf. 96. The light weight gypsum board of claim 95, wherein the board has a density of from about 24 pcf to about 31 pcf. 97. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets; the set gypsum core comprising a gypsum crystal matrix having walls defining and separating air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average air void size being less than about 100 microns in diameter, the average wall thickness and average air void size measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), and the gypsum crystal matrix formed such that the board exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick; and the board having a density of about 35 pcf or less. 98. The light weight gypsum board of claim 97, wherein the average air void size is between about 10 microns in diameter and about 100 microns in diameter. 99. The light weight gypsum board of claim 97, wherein the walls have an average thickness from about 70 microns to about 120 microns. 100. The light weight gypsum board of claim 97, wherein the board has a density of from about 24 pcf to about 35 pcf. 101. The light weight gypsum board of claim 100, wherein the hoard has a density of from about 24 pcf to about 31 pcf. 102. A light weight gypsum board comprising: a set gypsum core disposed between two cover sheets, the set gypsum core comprising a gypsum crystal matrix having a plurality of voids which provide a total void volume and a size distribution comprising (i) voids having a size less than about 5 microns in diameter, (ii) voids having a size of about 10 microns to about 100 microns in diameter, and (iii) voids having a size greater than about 100 microns in diameter, the voids measured using scanning electron photomicrograph imaging; about 10% to about 35% of the voids being less than about 5 microns in diameter, and the voids having a size of more than about 10 microns and the voids having a size of less than about 5 microns being in a ratio of from about 2.3:1 to about 9:1; andthe crystal matrix having walls defining and separating air voids within the gypsum matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average wall thickness measured using scanning electron photomicrograph imaging;and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473, and the voids of less than about 5 microns, the voids of about 10 microns to less than about 100 microns and the voids of greater than about 100 microns in amounts to provide the board with a density of about 31 pcf or less. 103. The light weight gypsum board of claim 102, wherein the walls have an average thickness from about 70 microns to about 120 microns. 104. The light weight gypsum board of claim 102, wherein at least a portion of the walls includes reinforced densified wall surfaces. 105. The light weight gypsum board of claim 102, wherein the board has a density of from about 24 pcf to about 31 pcf. 106. The light weight gypsum board of claim 105, wherein the board has a density of from about 27 pcf to about 30 pcf. 107. The light weight gypsum board of claim 102, wherein the set gypsum core is formed from a slurry comprising water, stucco, and an amount of a starch effective to increase the core hardness of the set gypsum core relative to a set gypsum core formed from the slurry without the starch. 108. The light weight gypsum board of claim 107, wherein the starch comprises a pregelatinized starch in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 109. The light weight gypsum board of claim 102, wherein the set gypsum core is funned from a slurry comprising water, stucco, foam, and dispersant. 110. The light weight gypsum board of claim 109, wherein the dispersant comprises a naphthalenesulfonate dispersant. 111. The light weight gypsum board of claim 110, wherein the slurry further comprises a pregelatinized starch, the naphthalenesulfonate dispersant being in an amount from about 0.1% to about 3% by weight based on the weight of the stucco, and the pregelatinized starch being in an amount from about 0.5% to about 10% by weight based on the weight of the stucco. 112. The light weight gypsum board of claim 111, wherein the slurry further comprises a water-soluble polyphosphate-containing compound. 113. The light weight gypsum board of claim 102, wherein the set gypsum core is formed from a slurry comprising water, stucco, and a water-soluble polyphosphate-containing compound. 114. The light weight gypsum board of claim 113, wherein the water-soluble polyphosphate-containing compound is in an amount from about 0.1% to about 0.4% by weight based on the weight of the stucco. 115. The light weight gypsum board of claim 1, wherein the board has a density of from about 24 pcf to about 35 pcf. 116. The light weight gypsum board of claim 1, wherein the board has a density of from about 24 pcf to about 33 pcf. 117. The light weight gypsum board of claim 1, wherein the board has a density of from about 27 pcf to about 30 pcf. 118. The light weight gypsum board of claim 26, wherein the board has a density of from about 24 pcf to about 35 pcf. 119. The light weight gypsum board of claim 26, wherein the board has a density of from about 24 pcf to about 33 pcf. 120. The light weight gypsum board of claim 26, wherein the board has a density of from about 27 pcf to about 30 pcf. 121. The light weight gypsum hoard of claim 44, wherein the board has a density of from about 24 pcf to about 35 pcf. 122. The light weight gypsum board of claim 44, wherein the board has a density of from about 24 pcf to about 33 pcf. 123. The light weight gypsum board of claim 44, wherein the board has a density of from about 27 pcf to about 30 pcf. 124. The light weight gypsum board of claim 48, wherein the board has a density of from about 24 pcf to about 35 pcf. 125. The light weight gypsum hoard of claim 48, wherein the board has a density of from about 24 pcf to about 33 pcf. 126. The light weight gypsum board of claim 48, wherein the board has a density of from about 27 pcf to about 30 pcf.
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