Low dust gypsum wallboard.
Abstract
La invención provee productos de tablero de yeso de baja producción de polvo, de baja densidad, que tienen volúmenes totales de huecos del núcleo que corresponden a bajas densidades, en la escala de alrededor de 10 a 30 pcf (alrededor de 160.1 a 480.3 g/dm3). Los tableros tienen un núcleo de yeso fraguado, formado entre dos hojas de cubierta substancialmente paralelas, teniendo de preferencia el núcleo de yeso fraguado un volumen hueco total de alrededor de 80 por ciento a alrededor de 92 por ciento y hecho de una lechada que incluye estuco, almidón pregelatinizado y un dispersante naftalensulfonato. La combinación del almidón pregelatinizado y el dispersante naftalensulfonato provee también un efecto parecido a pegamento para unir entre si los cristales de yeso fraguado. La formulación del tablero, junto con pequeños huecos de aire o burbujas (y huecos de agua) provee control de polvo durante las operaciones de cortar, aserrar, arrancar, marcar/golpear, clavar o atornillar, o perforar los productos que contienen yeso. La invención provee también un método para formar los productos de yeso de baja densidad, de baja producción de polvo, que incluye la introducción de espuma de jabón en cantidad suficiente para tomar un volumen hueco total, incluyendo los huecos de aire, de preferencia de alrededor de 80 por ciento a alrededor de 92 por ciento en el núcleo de yeso fraguado, que corresponde a una densidad de núcleo de yeso fraguado de alrededor de 10 pcf a alrededor de 30 pcf (alrededor de 160.1 a alrededor de 480.3 g/dm3). Los tableros productos mediante este método generan significativamente menos polvo durante el tratamiento.

Term
1 yearleft in the term
Expires 9 October 2027.
- Priority
- Filed
- Granted
- Today
- Expires
45 claims: 5 independent, 40 dependent
- 1REIVINDICACIONES INSTITUTO MEXICANO DE LA PROPIEDAD industrial 1. Un tablero de yeso caracterizado porque comprende:un núcleo de yeso fraguado dispuesto entre dos hojas de cubierta;el núcleo de yeso fraguado formado de un fango que comprende agua, espuma, y estuco;el núcleo de yeso fraguado que comprende una matriz de cristal de yeso que tiene una distribución de tamaño de poro que comprende (i) huecos de agua que tienen un tamaño de poros menor que 5 mieras de diámetro, (¡i) huecos de aire que tienen un tamaño de poros de al menos 5 mieras y menor que 50 mieras de diámetro, (iii) huecos de aire que tienen un tamaño de poros desde 50 mieras a 100 mieras de diámetro, y (iv) huecos de aire que tienen un tamaño de poros mayor que 100 mieras de diámetro, los huecos de aire que tienen un tamaño de poros mayor que 100 mieras de diámetro que comprende al menos 20% del volumen de huecos total del núcleo de yeso fraguado;la mayoría de los huecos de aire tienen un diámetro de 100 mieras o menos;la matriz de cristal de yeso se forma de manera que el núcleo de yeso fraguado tiene una dureza de núcleo promedio de al menos 49 N (aproximadamente 11 libras) como se determina de acuerdo con ASTM C-473;y el tablero que tiene una densidad de aproximadamente 560 kg/m 3 (aproximadamente 35 pcf) o menos.
- 2El tablero de yeso de conformidad con la reivindicación 1, caracterizado porque los huecos se miden utilizando procesamiento de imágenes tridimensional adquiridas por análisis de barrido CT de rayos X (XMT).
- 3El tablero de yeso de conformidad con la reivindicación 2, caracterizado porque al menos 50% del volumen de huecos total comprende huecos de aire que tienen un tamaño de poros mayor que 50 mieras de diámetro.
- 4El tablero de yeso de conformidad con la reivindicación 2, IMPIO^ INSTITUTO MEXICANO DE LA PROPIEDAD Qvi caracterizado porque la densidad del núcleo de yeso fraguado es cíesele 38b“Rg7rn 3 (aproximadamente 24 pcf) a 560 kg/m 3 (aproximadamente 35 pct).
- 5El tablero de yeso de conformidad con la reivindicación 4, caracterizado porque el fango que forma el núcleo de yeso fraguado además comprende (i) almidón en una cantidad desde 0.5% a 10% en peso basado en el peso del estuco, o (ii) un compuesto de trimetafosfato seleccionado del grupo que consiste de trimetafosfato de sodio, trimetafosfato de potasio, trimetafosfato de litio, y trimetafosfato de amonio, el compuesto de trimetafosfato que está presente en una cantidad desde 0.12% a 0.4% en peso basado en el peso del estuco, o (iii) dispersante naftalen sulfonato en una cantidad desde 0.1% a 3.0% en peso basado en el peso del estuco, o cualquier combinación de (i) - (iii).
- 6El tablero de yeso de conformidad con la reivindicación 2, caracterizado porque el almidón es un almidón pregelatinizado.
- 7El tablero de yeso de conformidad con la reivindicación 2, caracterizado porque el tablero, cuando tiene un espesor de 1.3 cm (aproximadamente Vz in), tiene (i) un peso seco desde 5 kg/SQM (aproximadamente 1000 Ib/MSF) a 6.8 kg/SQM (aproximadamente 1400 Ib/MSF), o (ii) una proporción de resistencia a extracción de clavos a dureza de núcleo desde 4 a 8, cada uno como se determina de acuerdo con ASTM C473, o (¡ii) una resistencia a extracción de clavos de al menos 290 N (aproximadamente 65 Ib), como se determina de acuerdo con ASTM C473, o (iv) una resistencia flexural promedio de al menos 160 N. (aproximadamente 36 Ib) en una dirección de la máquina y/o 476 N (aproximadamente 107 Ib) en una dirección transversal de la máquina, como se determina de acuerdo con ASTM C473, o cualquier combinación de (i) - (iv).
- 8El tablero de yeso de conformidad con la reivindicación 2, IMPI INSTITUTO MEXICANO DE LA PROPIEDAD caracterizado porque el núcleo de yeso fraguado comprencle huecos de aire y huecos de agua, los huecos de aire con un tamaño de pcrrcrtíe'S' FYiicras o más y los huecos de agua con un tamaño de poro menor que 5 mieras, en un volumen de huecos de aire a huecos de agua desde 1.8 a 1 a 9 a 1.
- 9El tablero de yeso de conformidad con la reivindicación 8, caracterizado porque el volumen de huecos de aire a huecos de agua es de 2.3 a 1 a 9 a 1.
- 10El tablero de yeso de conformidad con la reivindicación 2, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 75% a 92% del volumen de núcleo.
- 11El tablero de yeso de conformidad con la reivindicación 10, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 80% a 92% del volumen de núcleo.
- 12El tablero de yeso de conformidad con la reivindicación 2, caracterizado porque los huecos de aire tienen un tamaño de poro promedio mayor que 20 mieras en diámetro.
- 13El tablero de yeso de conformidad con cualquiera de las reivindicaciones 1 a 12, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 510 kg/m 3 (aproximadamente 32 pcf).
- 14El tablero de yeso de conformidad con la reivindicación 13, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 500 kg/m 3 (aproximadamente 31 pcf).
- 15El tablero de yeso de conformidad con la reivindicación 14, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 INSTITUTO MEXICANO , DE LA PROMtDAD (aproximadamente 24 pcf) a 480 kg/m (aproximadamente 30
- 16Un tablero de yeso caracterizad©—p rqu©-Gor»prende_uun. núcleo de yeso fraguado dispuesto entre dos hojas de cubierta;el núcleo de yeso fraguado formado de un fango que comprende agua, espuma, y estuco;el núcleo de yeso fraguado que comprende una matriz de cristal de yeso que tiene una distribución de tamaño de poro que comprende (i) huecos de agua que tienen un tamaño de poros menor que 5 mieras de diámetro, (ii) huecos de aire que tienen un tamaño de poros de al menos 5 mieras y menor que 50 mieras de diámetro, (iii) huecos de aire que tienen un tamaño de poros desde 50 mieras a 100 mieras de diámetro, y (iv) huecos de aire que tienen un tamaño de poros mayor que 100 mieras de diámetro, los huecos de aire que tienen un tamaño de poros mayor que 100 mieras de diámetro que comprende al menos 20% del volumen de huecos total del núcleo de yeso fraguado;el tamaño de poros de hueco de aire que tiene mayor frecuencia es un diámetro de 100 mieras o menos;la matriz de cristal de yeso se forma de manera que el núcleo de yeso fraguado tiene una dureza de núcleo promedio de al menos 49 N (aproximadamente 11 libras) como se determina de acuerdo con ASTM C-473;y el tablero que tiene una densidad de 560 kg/m 3 (aproximadamente 35 pcf) o menos.
- 17El tablero de yeso de conformidad con la reivindicación 16, caracterizado porque los huecos se miden utilizando procesamiento de imágenes tridimensional adquiridas por análisis de barrido CT de rayos X (XMT).
- 18El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque al menos 50% del volumen de huecos total comprende huecos de aire que tienen un tamaño de poros mayor que 50 mieras de diámetro.
- 19El tablero de yeso de conformidad con la reivindicación 17, INSTITUTO MEXICANO O» LA mcflSDAr YtaeYía, J’fz mnumtAL caracterizado porque la densidad del núcleo de yeso fraguado es desde 38ÜKg/m (aproximadamente 24 pcf) a 560 kg/m 3 (aproximadamenfé'35 pcf).
- 20El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque el fango que forma el núcleo de yeso fraguado además comprende (i) almidón en una cantidad desde 0.5% a 10% en peso basado en el peso del estuco, o (ii) un compuesto de trimetafosfato seleccionado del grupo que consiste de trimetafosfato de sodio, trimetafosfato de potasio, trimetafosfato de litio, y trimetafosfato de amonio, el compuesto de trimetafosfato que está presente en una cantidad desde 0.12% a 0.4% en peso basado en el peso del estuco, o (¡ii) dispersante naftalen sulfonato en una cantidad desde 0.1% a 3.0% en peso basado en el peso del estuco, o cualquier combinación de (i) - (iii).
- 21El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque el almidón es un almidón pregelatinizado.
- 22El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque el tablero, cuando tiene un espesor de 1.3 cm (aproximadamente % in), tiene (i) un peso seco desde 5 kg/SQM (aproximadamente 1000 Ib/MSF) a 6.8 kg/SQM (aproxiriiadamente 1400 Ib/MSF), o (¡i) una proporción de resistencia a extracción de clavos a dureza de núcleo desde 4 a 8, cada uno como se determina de acuerdo con ASTM C473, o (iii) una resistencia a extracción de clavos de al menos 290 N (aproximadamente 65 Ib), como se determina de acuerdo con ASTM C473, o (iv) una resistencia flexural promedio de al menos 160 N (aproximadamente 36 Ib) en una dirección de la máquina y/o 476 N (aproximadamente 107 Ib) en una dirección transversal de la máquina, como se determina de acuerdo con ASTM C473, o cualquier combinación de (i) - (iv).
- 23El tablero de yeso de conformidad con la reivindicación 17, IMPI®^ INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL caracterizado porque el núcleo de yeso fraguado comprende huecos de aire y huecos de agua, los huecos de aire con un tamaño de poro de 5 mieras o más con huecos de agua con un tamaño de poro menor que 5 mieras, en un volumen de huecos de aire a huecos de agua desde 1.8 a 1 a 9 a 1.
- 24El tablero de yeso de conformidad con la reivindicación 23, caracterizado porque el volumen de huecos de aire a huecos de agua es de 2.3 a 1 a 9 a 1.
- 25El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 75% a 92% del volumen de núcleo.
- 26El tablero de yeso de conformidad con la reivindicación 25, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 80% a 92% del volumen de núcleo.
- 27El tablero de yeso de conformidad con la reivindicación 17, caracterizado porque los huecos de aire tienen un tamaño de poro promedio mayor que 20 mieras en diámetro.
- 28El tablero de yeso de conformidad con cualquiera de las reivindicaciones 16 a 27, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 510 kg/m 3 (aproximadamente 32 pcf).
- 29El tablero de yeso de conformidad con la reivindicación 28, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 500 kg/m 3 (aproximadamente 31 pcf).
- 30El tablero de yeso de conformidad con la reivindicación 29, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 IMPI INSTITUTO MEXICANO I5E LA PROPIEDAD (aproximadamente 24 peí) a 480 kg/m 3 (aproximadamente 30 pc$ D ' AL
- 31Un tablero de yeso caracterizadcnp0Yqtré~Y!Sh , ipré’ñ3e , :'' LU CIFi núcleo de yeso fraguado dispuesto entre dos hojas de cubierta;el núcleo de yeso fraguado formado de un fango que comprende agua, espuma, y estuco;el núcleo de yeso fraguado que comprende una matriz de cristal de yeso que tiene una distribución de tamaño de poro que comprende (i) huecos de agua que tienen un tamaño de poros menor que 5 mieras de diámetro, (¡i) huecos de aire que tienen un tamaño de poros de al menos 5 mieras y menor que 50 mieras de diámetro, (¡ii) huecos de aire que tienen un tamaño de poros desde 50 mieras a 100 mieras de diámetro, y (iv) huecos de aire que tienen un tamaño de poros mayor que 100 mieras de diámetro, los huecos de.aire que tienen un tamaño de poros mayor que 100 mieras de diámetro que comprende al menos 20% del volumen de huecos total del núcleo de yeso fraguado;el tamaño de poros de hueco de aire promedio es menor que 100 mieras de diámetro;la matriz de cristal de yeso se forma de manera que el núcleo de yeso fraguado tiene una dureza de núcleo promedio de al menos 49 N (aproximadamente 11 libras) como se determina de acuerdo con ASTM C-473;y el tablero que tiene una densidad de 560 kg/m 3 (aproximadamente 35 pcf) o menos.
- 32El tablero de yeso de conformidad con la reivindicación 31, caracterizado porque los huecos se miden utilizando procesamiento de imágenes tridimensional adquiridas por análisis de barrido CT de rayos X (XMT).
- 33El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque al menos 50% del volumen de huecos total comprende huecos de aire que tienen un tamaño de poros mayor que 50 mieras de diámetro.
- 34El tablero de yeso de conformidad con la reivindicación 32, IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL caracterizado porque la densidad del núcleo de yeso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 560 kg/m 3 (aproximadamente 35 pcf).
- 35El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque el fango que forma el núcleo de yeso fraguado además comprende (i) almidón en una cantidad desde 0.5% a 10% en peso basado en el peso del estuco, o (¡i) un compuesto de trimetafosfato seleccionado del grupo que consiste de trimetafosfato de sodio, trimetafosfato de potasio, trimetafosfato de litio, y trimetafosfato de amonio, el compuesto de trimetafosfato que está presente en una cantidad desde 0.12% a 0.4% en peso basado en el peso del estuco, o (iii) dispersante naftalen sulfonato en una cantidad desde 0.1% a 3.0% en peso basado en el peso del estuco, o cualquier combinación de (i) - (iii).
- 36El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque el almidón es un almidón pregelatinizado.
- 37El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque el tablero, cuando tiene un espesor de 1.3 cm (aproximadamente 1 Λ in), tiene (i) un peso seco desde 5 kg/SQM (aproximadamente 1000 Ib/MSF) a 6.8 kg/SQM (aproximadamente 1400 Ib/MSF), o (ii) una proporción de resistencia a extracción de clavos a dureza de núcleo desde 4 a 8, cada uno como se determina de acuerdo con ASTM C473, o (iii) una resistencia a extracción de clavos de al menos 290 N (aproximadamente 65 Ib), como se determina de acuerdo con ASTM C473, o (iv) una resistencia flexural promedio de al menos 160 N (aproximadamente 36 Ib) en una dirección de la máquina y/o 476 N (aproximadamente 107 Ib) en una dirección transversal de la máquina, como se determina de acuerdo con ASTM C473, o cualquier combinación de (i) - (iv).
- 38El tablero de yeso de conformidad con la reivindicación 32, INSTITUTO MEXICANO LA TRCFIEDAD industrial caracterizado porque el núcleo de yeso fraguado comoieníl.Q^bU^cos.^de aire y huecos de agua, los huecos de aire con un tamaño de poro de 5 mieras o más y los huecos de agua con un tamaño de poro menor que 5 mieras, en un volumen de huecos de aire a huecos de agua desde 1,8 a 1 a 9 a 1.
- 39El tablero de yeso de conformidad con la reivindicación 38, caracterizado porque el volumen de huecos de aire a huecos de agua es de 2.3 a 1 a 9 a 1.
- 40El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 75% a 92% del volumen de núcleo.
- 41El tablero de yeso de conformidad con la reivindicación 40, caracterizado porque el núcleo de yeso fraguado tiene un volumen de hueco total desde 80% a 92% del volumen de núcleo.
- 42El tablero de yeso de conformidad con la reivindicación 32, caracterizado porque los huecos de aire tienen un tamaño de poro promedio mayor que 20 mieras en diámetro.
- 43El tablero de yeso de conformidad con cualquiera de las reivindicaciones 31 a 42, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 510 kg/m 3 (aproximadamente 32 pcf).
- 44El tablero de yeso de conformidad con la reivindicación 43, caracterizado porque la densidad del núcleo de peso fraguado es desde 380 kg/m 3 (aproximadamente 24 pcf) a 500 kg/m 3 (aproximadamente 31 pcf).
- 45El tablero de yeso de conformidad con la reivindicación 44, caracterizado porque la densidad del núcleo dé peso fraguado es desde 380 kg/m 3 HNSTITUTO MEXICANO ®£4Λ paonts.w ‘«'iBUOTtó'At (aproximadamente 24 pcf) a 480 kg/m 3 (aproximadamente 30 pcf).
Independent claims45
340 paragraphs in 44 sections, as filed
(54) Title: LIGHTWEIGHT PLASTER BOARDS AND MUDS AND METHODS TO PREPARE THEM.
(54) Title: LOW DUST GYPSUM WALLBOARD.
(57) Summary
The invention provides low-density, low-dust gypsum board products having total core void volumes corresponding to low densities, on the scale of about 10 to 30 pcf (about 160.1 to 480.3 g / dm3). The boards have a set gypsum core, formed between two substantially parallel deck sheets, with the set gypsum core preferably having a total void volume of about 80 percent to about 92 percent and made of a grout including stucco. , pregelatinized starch and a naphthalenesulfonate dispersant. The combination of the pregelatinized starch and the naphthalenesulfonate dispersant also provides a glue-like effect to bond the set gypsum crystals together. The board formulation, along with small air gaps or bubbles (and water gaps) provides dust control during cutting, sawing, ripping, marking / hitting, nailing or screwing, or drilling of gypsum-containing products. The invention also provides a method of forming low-dust, low-density gypsum products, including introducing soap scum in sufficient quantity to take up a total void volume, including air voids, preferably around 80 percent to about 92 percent in the set gypsum core, which corresponds to a set gypsum core density of about 10 pcf to about 30 pcf (about 160.1 to about 480.3 g / dm3). Boards produced by this method generate significantly less dust during treatment.
(57) Abstract
This invention provides low dust low density gypsum wallboard products having high total core void volumes, corresponding to low densities in the range of about 10 to 30 pcf. The wallboards have a set gypsum core formed between two substantially parallel cover sheets, the set gypsum core preferably having a total void volume from about 80% to about 92%, and made from a slurry including stucco, pregelatinized starch, and a naphthalenesulfonate dispersant. The combination of the pregelatinized starch and the naphthalenesulfonate dispersant also provides a glue-like effect in binding the set gypsum crystals together. The wallboard formulation, along with small air bubble voids (and water voids) provides dust control during cutting, sawing, routing, snapping, nailing or screwing down, or drilling of the gypsumcontaining products. This invention also provides a method of making the low dust low density gypsum products including the introduction of soap foam ¡n an amount sufficient to form a total void volume, including air voids, preferably from about 80% to about 92% ¡n the set gypsum core, corresponding to a set gypsum core density from about 10 pcf to about 30 pcf. The wallboards produced by the method generate significantly less dust during working.
PATENT TITLE No. 360873
<img file="MX360873B_D0001.tif" />
<img file="MX360873B_D0002.tif" />
Headlines):
Home:
UNITED STATES GYPSUM COMPANY
550 West Adams Street, Chicago, Illinois, 60661-3676, USA
<td>Denomination:</td><td>LIGHTWEIGHT PLASTER BOARDS AND MUDS AND METHODS TO PREPARE THEM.</td>
B32B1 /
Classification:
Inventors):
<img file="MX360873B_D0003.tif" />
d Industrial.
non-extendable, counted to
B28 / 14;
C04B210
CIP: CPC:
B32B2307 /, B 08/13; B32B17 / 02; B32B29 / 00; > 2307/558; B32B2307 / 5825;
04B24 / 226; C04B24 / 383; B3J / 0061; C04B2103 / 0075; 30/97; Y10T428 / 232 *
MX / a / 20Q) 8Q90 | fy
Validity: V Date of V Date of Exp
The reference patent is g
In accordance with article 23 from the filing da te of the Industrial Property Law ....... / 05/1999, 01/26/2004, 06/16/2005, Í3 / ÍBR018); articles 1, 3, fraction V, subsection a), 4, 12/1999, amended on 07/01/2002, 07/15/2004, the Organic Statute of the Mexican Institute of 1/2004 and 09/13/2007) ; 1, 3 and 5 subsection a) of the Agreement that delegates the Directors, Regional Office Holders, Divisional Deputy Directors,
Who subscribes to the present title lo / 2004 and 7/09/2007); articles 1, 3, 4, I
Industrial Property (DOF 12/27/1999, amended on 10/10/2002, powers of the Deputy Directors General, Coordinator, Directors'bivisiÍ Departmental Coordinators and other subordinates of the Mexican Institute of Industrial Property (DOF 12/15/1999 , reformed on 04/02/2000, · 07/29/2004, 08/04/2004 and 09/13/2007).
This letter is signed with an advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law; 3 of its Regulations, and 1 fraction III, 2 fraction V, 26 BIS and 26 TER of the Agreement establishing the guidelines for the use of the Electronic Payment and Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.
THE DIVISIONAL DIRECTOR OF PATENTS
NAHANNY CANAL REYES
<img file="MX360873B_D0004.tif" />
Original string:
NAHANNY MARISOL CANAL REYES | 00001000000403252793 | Administration Service
Tax | 1695 || MX / 2019/4060 | MX / a / 2013/009055 | Normal patent title with divisional PCT | 1223 | GAGV | Page (s) | nwO3Wa9z1 / Y5 + jj / QFv8khgSKzM =
Digital stamp:
E0Fv 4sRpJmRGWabZyMWWaz8 + // + eagoJtxyqa1BqFFOVqAaac6ONYqc52xqKOJkUQ2 / h + bcwZDwJOeZtQUiUD2ZX / k iUM74 / 7 + PZIsl959¡NwSpObtW15 + kj / cHKaxBmdDLfNUReQFDc5OOpS3FW100XH4FgcxdsZEzdPPnycc0R6PoXxCkH EVdkZ3¡LYYWALt15h0dwFx YDXrfdk7N6TMe9ODaQtRly8E9ljR4QiNXEj7X3vAik6KVEEvyluBN9O7s6EOYZv9 + B9 + == eJNysCyBdDFYEnEYL7xC2NIQSIWwe7rwlmlnHUq8YX5WkaHxtCd3Apxj1WVQ86S1RhCbfk0A
Arenal No. 550, Floor 1, Pueblo Santa María Tepepan, Xochimilco, 1S020, Mexico City.
(55) 53340700 www.gob.mx/impi
<img file="MX360873B_D0005.tif" />
3GO873
IMPI® mexican institute of the r «o« eoAD fNDUSTWAL
LIGHTWEIGHT PLASTER BOARDS AND MUDS AND METHODS FOR
ELABORATE THEM
Field of the Invention
This invention relates to a method of forming a gypsum board, in which the generation of dust during board manufacturing is significantly reduced. More particularly, the method includes introducing soap scum in an amount sufficient to form a total void volume, from about 80 percent to about 92 percent, in a set gypsum core, corresponding to a core density. set plaster of about 10 pcf to about 30 pcf (160.1 g / dm<sup>3</sup> at 480 g / dm<sup>3</sup>), which provides significantly reduced dust formation during production. It also refers to a low-dust gypsum board, made using the method.
Background of the Invention
Certain properties of gypsum (calcium sulfate dihydrate) make it very popular for use in the formation of industrial and construction products, such as drywall for walls. Gypsum is an abundant and generally low-cost raw material that, through a dehydration and rehydration process, can be cast, molded, or otherwise formed into useful forms. The base material from which gypsum board and other gypsum products are made is the semi-hydrated form of calcium sulfate (CaSO<sub>4</sub> . <sup>1</sup>/ 2 H<sub>2</sub>O), commonly called "stucco", which is produced by conversion
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY
<img file="MX360873B_D0006.tif" />
thermal of the dihydrate form of calcium sulfate (CaSO ^ HjO), from which one and a half water molecules have been removed.
Conventional gypsum-containing products, such as drywall, have many advantages, such as their low cost and ease of working, although substantial amounts of gypsum dust can be generated when products are cut or drilled. Various improvements have been obtained in the formation of gypsum-containing products, using starches as ingredients in the grouts used to form such products. Pregelatinized, glue-like starch can increase the flexural strength and compressive strength of gypsum-containing products, including gypsum board. Known gypsum board for walls contains starch at levels of less than about 10 Ibs / MSF. (48.82 g / m<sup>2</sup>).
It is also necessary to use substantial amounts of water in gypsum grouts containing pregelatinized starch to ensure proper flowability in the grout. Unfortunately, most of that water must eventually be expelled by drying, which is expensive due to the high cost of the fuels used in the drying process. This drying step is also time consuming. It has been found that the use of naphthalenesulfonate dispersants can increase the fluidity of the slurries, thereby solving the water demand problem. Furthermore, it has also been found that naphthalenesulfonate dispersants, if the level of use is high enough, can bind to starch<sup>, N5T</sup> DELA FROrSoAD <sup>W</sup> INDUSTRIAL pregelatinized to bind gypsum crystals together after drying, increasing the dry strength of the gypsum composite composition. Thus, the combination of the pregelatinized starch and the naphthalenesulfonate dispersant give a glue-like effect, by binding the set gypsum crystals together. It has not been recognized in the past that trimetaphosphate salts affect the water requirements of gypsum grout. However, the present inventors have discovered that increasing the level of the trimetaphosphate salt to previously unknown levels, in the presence of a specific dispersant, makes it possible to obtain appropriate flow capacity of the slurry, with unexpectedly low amounts of water, even in the presence of high levels of starch. Of course, this is highly desirable because, in turn, it reduces the use of fuel for drying as well as the processing time associated with subsequent steps in the water removal process. Thus, the inventors herein have also discovered that the dry strength of gypsum board can be increased by using a naphthalenesulfonate dispersant in combination with pregelatinized starch in the slurry used to form the board.
The gypsum boards of the present invention should be distinguished from acoustic boards or tiles, which do not have face sheets. The boards of the present invention should also be distinguished from acoustic boards or tiles that include polystyrene as a lightweight aggregate. It is very important that the acoustic boards and tiles mentioned above do not meet many of the ASTM standards that
IMPI ^ j
MEXICAN INSTITUTE TpSet-rfi
OF EXOMETY —W
INDUSTRIAL apply to drywall for walls. For example, known acoustic boards do not have the flexural strength of gypsum wall boards, including those of the present invention. Conversely, in order for acoustic boards or acoustic tiles to meet ASTM standards, an exposed surface of acoustic boards or acoustic tiles is required to have voids or depressions that would be undesirable in a drywall board, and Nail penetration resistance properties would be adversely affected.
Dust generation is a potential problem during the installation of any board. When working gypsum boards, for example, cutting, sawing, tearing, knocking, nailing or screwing, or drilling, substantial amounts of gypsum dust can be generated. For the purposes of this description, “dust formation and“ dust generation ”mean the release of dust into the surrounding workspace during the working operations of a gypsum-containing product, for example, when cutting, sawing, tearing , mark / gouge, nail or screw, or drill the board. Working also generally includes normal board handling, including dust produced by accidental scraping and mortising of the boards during transportation, carrying, and installation. If a way could be found to produce a low density board, in which dust generation is significantly reduced, this would represent a particularly useful contribution to the art.
<img file="MX360873B_D0007.tif" />
IMPI
MEXICAN INSTITUTE M THE PROPERTY Brief description of the industrial invention
The invention generally encompasses a gypsum board to produce dust, which includes a set gypsum core formed between two substantially parallel roof sheets; the set gypsum core having a total hollow volume of about 75 percent to about 95 percent; where the set gypsum core is made of a gypsum-containing grout, comprising water, stucco, pregelatinized starch, and a naphthalenesulfonate dispersant; where the pregelatinized starch is present in an amount of about 0.5 weight percent to about 10 weight percent, based on the weight of the stucco. Preferably the naphthalenesulfonate dispersant is present in an amount of about 0.1 percent to 3.0 percent by weight, based on the weight of dry stucco. Optionally, sodium trimetaphosphate is present in an amount of at least about 0.12 weight percent, based on the weight of the stucco. In a preferred embodiment, the trimetaphosphate salt is present in an amount of about 0.12 to 0.4 weight percent, based on the weight of dry stucco.
In a preferred embodiment, the invention comprises a low-dust gypsum board, comprising a set gypsum core including pregelatinized starch and a naphthalenesulfonate dispersant, formed between two substantially parallel deck sheets; the set gypsum core having a total hollow volume of about 80 percent to about 92 percent; where at least 60 percent of the total void volume
IMPI
MEXICAN INSTITUTE OF INDUSTRY PROPERTY!
<img file="MX360873B_D0008.tif" />
it comprises air voids that have an average diameter less than ____ approximately 100 microns; and having the set gypsum core a density of about 10 pcf to about 30 pcf (160.1 to 480.3 g / dm<sup>3</sup>. The term "pcf" is defined as pounds per cubic foot (lb / ft<sup>3</sup>) and the term “g / dm<sup>3</sup> it is defined as grams per cubic decimeter. The gypsum core is made of a gypsum-containing suspension, comprising stucco, pregelatinized starch, and naphthalene sulfonate dispersant; where the pregelatinized starch is present in an amount of from about 0.5 weight percent to about 10 weight percent, based on the weight of the stucco. Preferably the naphthalenesulfonate dispersant is present in an amount of about 0.1 percent to 3.0 percent by weight, based on the weight of the dry stucco.
Gypsum board made according to the invention has high strength, but much less weight than conventional wall boards. Furthermore, it has been found that, by securing total core void volumes in the set gypsum core, from about 75 percent to about 95 percent, and preferably from about 80 percent to about 92 percent, Much less dust is generated by cutting, sawing, tearing, marking / hitting, nailing or screwing, or drilling into boards made in accordance with this mode.
In another embodiment, the invention constitutes a method for forming high-strength, low-dust gypsum board by mixing a gypsum-containing slurry, comprising water, stucco, pregelatinized starch, and a naphthalenesulfonate dispersant, where the naphthalenesulfonate dispersant is present in a quantity
<img file="MX360873B_D0009.tif" />
about 0.1 percent to 3.0 percent by weight, based on dry stucco weight; where the pregelatinized starch is present in an amount of at least about 0.5 weight percent to about 10 weight percent, based on the weight of the stucco; and adding enough soap scum to the gypsum-containing grout to form a total void volume, including air voids, of about 75 percent to about 95 percent on a finished board. The resulting gypsum-containing grout is deposited on a first paper or other suitable covering sheet, and a second paper or other appropriate covering sheet is placed on the deposited grout to form a gypsum board. The gypsum board is cut after the gypsum-containing grout has hardened enough to be cut, and the resulting gypsum board is dried, to provide a set gypsum core in the finished board, with a total hollow volume, including air voids, from about 75 percent to about 95 percent. Optionally the gypsum-containing grout contains a trimetaphosphate salt, for example sodium trimetaphosphate. Other conventional ingredients will also be used in the grout including, when appropriate: accelerators, binders, waterproofing agents, fiberglass, clay, biocide, and other known ingredients.
In yet another embodiment, the invention is a method of using a low-dust gypsum board by providing a low-dust gypsum board with a gypsum core.
SET MEXICAN INSTITUTE which has a total hollow volume of about ^ B'Vs p ^^ at about 95 percent; where mgnpR ai an pnr riontn hh total void volume comprises air voids having an average diameter less than about 100 microns, and including water voids having an average diameter less than about 5 microns; Work the board in such a way that it produces gypsum dust (for example cutting, sawing, tearing, marking / hitting, nailing or screwing, or drilling) and capturing a substantial portion of the gypsum dust in the gaps.
Brief description of the drawings
Figure 1 is a scanning electron photomicrograph of a cubed sample of set gypsum (11:08) at 15X magnification, illustrating one embodiment of the present invention.
Figure 2 is a scanning electron photomicrograph of a cubed set gypsum sample (11:30) at 15X magnification, illustrating one embodiment of the present invention.
Figure 3 is a scanning electron photomicrograph of a cubed cast gypsum sample (11.50) at 15X magnification, illustrating one embodiment of the present invention.
Figure 4 is a scanning electron photomicrograph of a cubed set gypsum sample (11:08) at 50X magnification, illustrating one embodiment of the present invention.
Figure 5 is a scanning electron photomicrograph of a cubed set gypsum sample (11:30) at 50X magnification, illustrating one embodiment of the present invention.
IMPI
PÍOWtDAI MEXICAN INSTITUTE
INDUSTRIAL
Figure 6 is a scanning electron photomicrograph of a cubed set of gypsum plaster (11:50) at 50X magnification, illustrating one embodiment of the present invention.
Figure 7 is a scanning electron photomicrograph of a cubed sample of set gypsum (11:50) at 500X magnification, illustrating one embodiment of the present invention.
Figure 8 is a scanning electron photomicrograph of a cubed sample of set gypsum (11:50) at 2,500X magnification, illustrating one embodiment of the present invention.
Figures 9-10 are scanning electron photomicrographs of a cubed sample of set gypsum (11:50) at 10,000X magnification, illustrating one embodiment of the present invention.
Detailed description of the invention
It has been unexpectedly discovered that a gypsum board, made using a gypsum-containing grout including stucco, pregelatinized starch and a naphthalenesulfonate dispersant, as well as an appropriate amount of soap scum, provides not only very low densities of board core , from about 10 to 30 pcf (160.1 to 480.3 g / dm<sup>3</sup>) (and therefore low weight of the board), but also low dust production when handling the board in the normal way, and when working, for example, when cutting, sawing, starting, marking / hitting, nailing or screwing, or drilling, when the total void volume of the set gypsum core is around 80 percent to about 92 percent. The wall board is consequently easier to cut than other products
<img file="MX360873B_D0010.tif" />
IMPI Mexican institute OF INDUSTRIAL property
<img file="MX360873B_D0011.tif" />
known. The introduction of the soap suds produces small air voids (bubbles) that, on average, can be less than around 100 microns in diameter, but are generally more than about 10 microns in diameter, and preferably over 20 microns in diameter. The invention requires that these small air bubbles, along with the water voids upon evaporation (generally with a diameter of about 5 microns or less, usually less than about 2 microns in diameter), are generally evenly distributed throughout the forged gypsum core in finished wallboard products. For example, the set gypsum core can have a total void volume of about 80 percent to about 92 percent, where at least 60 percent of the total void volume comprises air voids that have an average diameter of more about 10 microns, and at least 10 percent of the total void volume comprises water voids that have an average diameter less than about 5 microns. The low-density board core is believed to be prepared in this manner with a total gypsum core void volume of about 80 percent to about 92 percent as air and water voids (total core void volume) captures a substantial amount of small dust and other debris in exposed voids by cutting, sawing, tearing, marking / hitting, nailing or screwing, or drilling boards, so that the generation of dust is significantly reduced and it is not suspended in the air.
<img file="MX360873B_D0012.tif" />
<img file="MX360873B_D0013.tif" />
<sup>J</sup> INpUST * '*<sup>1</sup>
Rehydration of calcium sulfate semihydrate (stucco) and consequent hardening requires a specific theoretical amount of water (1.5 moles of water per mole of stucco) to form calcium sulfate dihydrate crystals. However, the business process generally requires excess water. This excess process water produces water gaps by evaporating in the gypsum crystal matrix, which are generally substantially irregular in shape, and are also linked to other water gaps, forming irregular channels in a generally continuous network between the set gypsum crystals. In contrast, air voids (bubbles) are introduced into the gypsum grout using soap suds. Air gaps are generally spherical / round in shape, and are also generally separated from other air gaps and are therefore generally discontinuous. The water voids can be distributed within the walls of the air voids (see, for example, Figures 8 to 10).
The effectiveness of dust capture depends on the composition of the set gypsum core. It has been found that naphthalenesulfonate dispersants, if the usage level is high enough, can be interlocked to the pregelatinized starch to bond the gypsum crystals together, after drying, thereby creating the dry strength of the gypsum composite composition .
Additionally, it has been unexpectedly discovered that the combination of the pregelatinized starch and the naphthalenesulfonate dispersant (organic phase) provides an effect similar to
IMPT glue, by bonding together the forge gypsum crystals<sup>ltl</sup>V>
<img file="MX360873B_D0014.tif" />
combines this formulation with a volume that is particularly distributed in the gaps, larger fragments are generated when marking / hitting the finished wall board. Larger pieces of gypsum generally produce less airborne dust. In contrast, if a conventional wall board formulation is used, smaller fragments are generated and thus more dust. For example, conventional wall boards can generate dust fragments by sawing them that have an average diameter of about 20-30 microns, and a minimum diameter of about 1 micron. In contrast, the gypsum wall boards of the present invention generate dust fragments when sawn, having an average diameter of about 30 to 50 microns, and a minimum diameter of about 2 microns; marking / tapping can produce even larger fragments.
On softer wall boards, dust can be captured in both water holes and air holes (for example, capturing small plaster needles as individual glass dust). The harder wall boards favor the capture of dust in their air voids, since larger pieces or larger fragments of gypsum core are generated when working these boards. In this case, the powder fragments are too large for the water holes, but are trapped in the air holes. It is possible, according to one embodiment of the present invention, to obtain increased dust capture by introducing a preferred distribution of gypsum plaster iMpr "
<img file="MX360873B_D0015.tif" />
void / pore size within the core prefers to have a small and large size distribution of voids, such as a distribution of air and water voids. In one embodiment, a preferred air gap distribution 5 can be prepared using soap suds. See examples 6 and 7 below.
The ratio of air voids (greater than about 10 microns) to water voids (less than about 5 microns) within the set gypsum core can range from about 1.8: 1 to about 9: 1. A preferred ratio of air voids (greater than about 10 microns) to water voids (less than about 5 microns) within the set gypsum core may vary from about / —- from 2: 1 to about 3: 1. In one embodiment, the gap / pore size distribution within the set gypsum core should vary from about 15 to 10 to 30 percent voids of less than about 5 microns, and from about 70 to 90 percent of voids. more than about 10 microns, as a percentage of the total gaps measured. In other words, the ratio of air voids (more than 10 microns) to water voids (less than 5 microns) within the gypsum core 20 varies from about 2.3: 1 to about 9: 1. In a preferred embodiment, the void / pore size distribution within the gypsum core should range from about 30 to 35 percent voids less than about 5 microns, and from about 65 to 70 percent voids larger than about 10 microns, as 25 percentage of the total gaps measured. In other words, the
IMPI
M LA industrial PSOFIBDAP
<img file="MX360873B_D0016.tif" />
ratio of air voids (greater than 10 microns) to water voids (less than 5 microns) within the gypsum core, varies from about '
1.8: 1 to about 2.3: 1
It is preferred that the average size of the air voids (bubbles) be less than about 100 microns in diameter. In a preferred embodiment, the gap / pore size distribution within the set gypsum core is: more than about 100 microns (20 percent); from about 50 micras to about 100 micras (30 percent) and less than about 50 micras (50 percent). That is, a preferred mean gap / pore size is about 50 microns.
Foam is preferred for introducing and controlling air gap (bubble) sizes and their distribution in the set gypsum core, and for controlling the density of the set gypsum core. A preferred scale is from about 0.2 Ib / MSF to about 0.6 Ib / MSF (0.976 g / m<sup>2</sup> at 2.92 g / m<sup>2</sup>); and a more preferred level of soap is around 0.45 Ib / MSF (2.19 g / m<sup>2</sup>)
The soap scum must be added in an amount effective to produce the desired densities, and in a controlled manner. In order to control the process, an operator must monitor the head of the dash formation line, and keep the enclosure full. If the envelope is not kept full, it results in wall boards with hollow edges, since the grout cannot fill the necessary volume. The volume of the envelope is maintained II by not increasing the use of soap to prevent the bubbles from breaking
IMPI • NSTrn / MEXICAN TO INDUSTRIAL PROPERTY
<img file="MX360873B_D0017.tif" />
air during the manufacture of the board (to better retain air bubbles), or by increasing the speed of air blowing. In this way, the volume of the envelope is generally controlled and adjusted, increasing or decreasing the use of soap, or increasing or decreasing the speed of the air blow. The technique of controlling the head includes adjustments to the “dynamic grout” on the table, adding soap foam to increase the volume of the grout, or decreasing the use of soap foam to decrease the volume of the grout.
In accordance with one embodiment of the present invention, gypsum-containing finished products are provided, made of gypsum-containing grouts, containing stucco, pregelatinized starch, and naphthalenesulfonate dispersant. The dispersing naphthalenesulfonate is present in an amount of about 0.1 percent to 3.0 percent by weight, based on the weight of the dry stucco. Pregelatinized starch is present in an amount of at least about 0.5 weight percent to about 10 weight percent, based on the weight of the dry stucco present in the formulation. Other ingredients that can be used in the grout include: binders, waterproofers, fiberglass agents, fiberglass, clay, biocide, and accelerators. The present invention requires the addition of a soap scum to the newly formulated gypsum-containing grouts to reduce the density of the finished gypsum-containing product; for example, a gypsum wall board, and to control dust formation by entering a total hollow volume
IMPIOS
MEXICAN INSTITUTE Ü »JK <sup>M</sup> ^ NDWHUAL from about 75 percent to about 95 percent ~~ yroe preference, from about 80 percent to about 92 pot cast; · in the form of small air holes (bubbles) and water holes in the core plaster cast. Preferably the average pore size distribution will be from about 1 micron (water voids) to about 40 to 50 microns (air voids).
Optionally, the combination of about 0.5 percent by weight to about 10. weight percent of pregelatinized starch; from about 0.1 weight percent to about 3.0 weight percent of dispersant naphthalenesulfonate, and a minimum of at least about 0.12 weight percent to about 0.4 weight percent of trimetaphosphate salt (all based on the weight of dry stucco used in gypsum grout) unexpectedly and significantly increases the fluidity of gypsum grout. This substantially reduces the amount of water required to produce a gypsum grout with sufficient flow capacity to be used in the formation of gypsum-containing products, such as gypsum wall board. The level of the sai trimetaphosphate, which is at least about twice that of common formulations (such as sodium trimetaphosphate), is believed to enhance the dispersing activity of the dispersing naphthalenesulfonate.
A dispersing naphthalenesulfonate should be used in gypsum-containing grouts prepared in accordance with the present invention. The naphthalenesulfonate dispersants used in the present invention include: polynaphthalenesulfonic acid and its salts (polynaphthalenesulfonates)
IMPI
MEXICAN INSTITUTE OF THE PBOH1DAI INDUSTRIAL
<img file="MX360873B_D0018.tif" />
and its derivatives, which are naphthalenesulfonic and formaldehyde products.
acid condensation
Particularly convenient polynaphthalenesulfonates include sodium and calcium naphthalenesulfonate. The average molecular weight of naphthalenesulfonates can vary from around 3,000 to 27,000, although it is preferred that the molecular weight is around 8,000 to 22,000 and, more preferably, that the molecular weight is around 12,000 to 17,000. As a commercial product, the higher molecular weight dispersant has a higher viscosity and lower solids content than a lower molecular weight dispersant. Useful naphthalenesulfonates include DILOFLO, available from GEO Specialty Chemicals, Cleveland, Ohio, USA, DAXAD, available from Hampshire Chemical Corp., Lexington, Massachusetts, USA, and LOMAR D, available from GEO Specialty Chemicals, Lafayette, Indiana, USA. Preferred naphthalenesulfonates are used as aqueous solutions on the 35 to 55 weight percent solids content scale, for example. Most preferred is to use the naphthalenesulfonates in the form of an aqueous solution, for example, on the scale of about 40-45 percent n ^ ===> weight of solids content. Alternatively, where appropriate, naphthalenesulfonates may be used in the form of a dry solid or in the form of a powder, such as LOMAR D, for example.
The polynaphthalenesulfonates useful in the present invention have the general structure (I):
<img file="MX360873B_D0019.tif" />
IMPI
MEXICAN INSTITUTE OF THE EROMEDAt) INDUSTRIAL
<img file="MX360873B_D0020.tif" />
where n is> 2 and where M is sodium, potassium, calcium and the like.
Dispersing naphthalenesulfonate, preferably as a solution at about 45 percent by weight in water, can be used on a scale of about 0.5 percent to about 3.0 percent by weight, based on the weight of the dry stucco used in the mixed gypsum formulation. A more preferred scale for dispersing naphthalenesulfonate is from about 0.5 percent to about 2.0 percent by weight, based on the weight of dry stucco, and a highly preferred scale is from about 0.7 percent to about 2.0 percent by weight, based on the weight of the dry stucco. In contrast, the known gypsum wall board contains this dispersant at levels of about 0.4 weight percent or less, based on the weight of the dry stucco.
In other words, the dispersing naphthalenesulfonate, on a dry weight basis, can be used on a scale of about 0.1 percent to about 1.5 percent by weight, based on the p so
IMPIAS Mexican Institute
PROPERTY of dry stucco used in the mixed plaster formulation. <sup>, h</sup>Vfi¡9<sup>,</sup>^ scaTa ^ TT§s preferred of the dispersing naphthalenesulfonate, based on the dry solids, is about 0.25 percent to about 0.7 percent by weight, based on the weight of dry stucco, and the scale that most preferred (based on dry solids) is about 0.3 percent to about 0.7 percent by weight, based on the weight of dry stucco.
The gypsum-containing grout may optionally contain a trimetaphosphate salt, for example, sodium trimetaphosphate. Any suitable water soluble metaphosphate or polyphosphate can be used in accordance with the present invention. It is preferred to use the trimetaphosphate salt, including the double salts, i.e. the trimetaphosphate salts having two cations. Particularly useful trimetaphosphate salts include: sodium trimetaphosphate, potassium trimetaphosphate, calcium trimetaphosphate, sodium and calcium trimetaphosphate, lithium trimetaphosphate, ammonium trimetaphosphate, and the like, or combinations thereof. A preferred trimetaphosphate salt is sodium trimetaphosphate. It is preferred to use the trimetaphosphate salt as an aqueous solution, for example, on the scale of about 10 to 15 weight percent solids content. Other cyclic or acyclic polyphosphates can also be used, such as those described in US Patent No. 6,409,825 to Yu and co-inventors, incorporated herein by reference.
Sodium trimetaphosphate is a known additive in gypsum-containing compositions, although it is generally used on the scale of about 0.05 percent to about 0.08 percent
IMPI
MEXICAN INSTHVrO DE LA WOHEDAt. INDUSTRIAL
<img file="MX360873B_D0021.tif" />
by weight, based on the weight of dry stucco used in the gypsum suspension. In the embodiments of the present invention, sodium trimetaphosphate (or other water soluble metaphosphate or polyphosphate) may be present on the scale of about 0.12 percent to about 0.4 percent by weight, based on the weight of the dry stucco used in the mixed gypsum formulation. A preferred scale for sodium trimetaphosphate (or other water soluble metaphosphate or polyphosphate) is from about 0.12 percent to about 0.3 percent by weight, based on the weight of the dry stucco used in the mixed gypsum formulation .
There are two forms of stucco, alpha and beta. These two types of stucco are produced by different calcination. Both the beta and alpha forms of stucco can be used in the present inventions.
Starches, including pregelatinized starch in particular, should be used in gypsum-containing grouts in accordance with the present invention. The preferred pregelatinized starch is pregelatinized corn starch, for example, pregelatinized cornmeal, available from Bunge Milling, St. Louis, Missouri, which has the following typical analysis: Humidity, 7.5 percent; protein, 8.0 percent; oil, 0.5 percent; crude fiber, 0.5 percent; ash, 0.3 percent; that it has a green resistance of 0.48 psi (3.30 kPa); and it has a loose overall density of 35.0 lb / ft<sup>3</sup> (560.35 g / dm<sup>3</sup>). Pregelatinized corn starch should be used in a quantity of at least
IMPI
MEXICAN INSTITUTE BE IA INDUSTRIAL PROPERTY
<img file="MX360873B_D0022.tif" />
minus about 0.5 percent by weight up to..flk 10 pair, percent by weight, based on the weight of the dry stucco used in the bed-containing grout.
The inventors of the present have further argued that an unexpected increase in dry strength (particularly in wall boards) can be obtained by using at least about 0.5 weight percent to about 10 weight percent of pregelatinized starch. (preferably, pregelatinized corn starch) in the presence of about 0.1 weight percent to 3.0 weight percent of dispersing naphthalenesulfonate (the levels of starch and naphthalenesulfonate based on the weight of dry stucco present in the formulation). This unexpected result can be obtained whether or not water soluble trimetaphosphate or polyphosphate is present.
Additionally, it has been unexpectedly found that pregelatinized starch can be used at levels of at least about 10 Ib / MSF (48.82 g / m<sup>2</sup>) or more, on drywall board, according to the present invention, but high strength and low weight can be achieved. Levels up to 35 to 45 Ib / MSF (170.87 to 219.69 g / m) have been shown to be effective<sup>2</sup>) of pregelatinized starch on the gypsum wall board. As an example, Formulation B, which is shown in Tables 1 and 2 below, includes 45 Ib / MSF (19.89 g / m<sup>2</sup>), but produced a board weight of 1042 Ib / MSF (5087 g / m<sup>2</sup>) which has excellent resistance. In this example ns **
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY
<img file="MX360873B_D0023.tif" />
(Formulation B) A dispersing naphthalenesulfonate was used as a 45 weight percent solution in water, at a level of 1.28 percent.
Another unexpected result can be obtained with the present invention when the combination of the dispersing naphthalenesulfonate, trimetaphosphate salt, is combined with pregelatinized corn starch and, optionally, paper fiber or fiberglass. Gypsum wall board made from formulations containing these three ingredients have increased strength and reduced weight and are more economically convenient due to reduced manufacturing water requirements. Useful levels of paper fiber can range up to about 2 weight percent, based on the weight of the dry stucco. Useful levels of fiberglass can range up to about 2 weight percent, based on the weight of dry stucco.
Accelerators can be used in the gypsum-containing compositions of the present invention, as described in US Patent No. 6,409,825, to Yu and co-inventors; which is incorporated here by means of this reference. A desirable heat resistant accelerator (HRA) can be made from dry grinding of calcined gypsum (calcium sulfate dihydrate). Small amounts of additives (usually about 5 weight percent), such as sugar, dextrose, boric acid, and starch, can be used to form this HRA. Sugar or dextrose are currently preferred. Another useful accelerator is a "climate stabilized accelerator or" dyne stable accelerator "(OSA), as described in the patent.
IMPI
M £ X1CAN <'INSTITUTE OF INDUSTRIAL PROETEDAb
<img file="MX360873B_D0024.tif" />
No. 3,573,947, which is incorporated herein by this reference.
The water / stucco ratio (w / s) is an important parameter, since the excess water must eventually be expelled by heating. In the embodiments of the present invention a preferred w / s ratio is from about 0.7 to about
1.3.
Other additives ^ for gypsum grout may include: accelerators, binders, waterproofing agents, paper or glass fibers, clay, biocides and other known constituents.
The cover sheets or sheets can be made of paper, as in conventional drywall boards, although other useful cover sheet materials known in the art (eg, glass fiber mats) can be used. The paper cover sheets provide strength characteristics to the wall board of and so. Useful cover sheet paper includes Manila 7-ply paper and News-Line 5-ply paper, available from United States Gypsum Corporation, Chicago, Illinois, USA, and Gray-Back 3-ply and Manila Ivory 3-ply, available from Caraustar, Newport, Indiana. The paper cover sheets comprise top cover sheets, or front paper, and bottom cover sheets, or backing paper. A preferred media cover sheet paper is News-Line 5 Sheets. A front cover sheet paper is manila 7 sheets.
Fibrous mats can also be used as one or both of the cover sheets. A useful fibrous mat is a fiber mat
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY
<img file="MX360873B_D0025.tif" />
glass in which the fiberglass filaments are joined together by means of an adhesive. Preferably the fibrous mats will be non-woven fiberglass mats, in which the fiberglass filaments are bonded together by means of an adhesive. It is highly preferred that non-woven fiberglass mats have a strong resin coating. For example, Duraglass non-woven fiberglass mats, available from Johns-Manville, weighing around 1.2 to 2.0 lb / 100 ft. Could be used.<sup>2</sup> (0.585-0.976 g / m<sup>2</sup>), with about 40 to 50 percent of the mat weight due to the resin coating. Other useful fibrous mats include, but are not limited to, woven glass mats and non-cellulosic fabrics.
The following examples further illustrate the invention. They should not be considered in any way as limitations to the scope of the invention.
Example 1
Sample grout formulations
The gypsum grout formulations are shown in Table 1 below. All values in Table 1 are expressed as a percentage by weight, based on the weight of the dry stucco. Values in parentheses are dry weight in mg / m<sup>2</sup>.
Table 1
<img file="MX360873B_D0026.tif" />
IMPI
MtXICANC INSTITUTE OF INDUSTRIAL PROPERTY
<td>Component</td><td>Formulation A</td><td> FOTrmrra-citmr-B—</td>
<td>Stucco (mg / m<sup>z</sup>)</td><td> 3,573.62</td><td> 3,436.</td>
<td>Sodium trimetaphosphate</td><td> 0.20 (7.32)</td><td> 0.30 (10.44)</td>
<td>Dispersant (naphthalenesulfonate)</td><td> 0.18 (6.59)</td><td> 0.58<sup>1</sup> (19.77)</td>
<td>Pregelatinized starch (dry powder)</td><td> 2.7 (97.64)</td><td> 6.4 (219.69)</td>
<td>Board starch</td><td> 0.41 (14.64)</td><td> 0</td>
<td>Heat Resistant Accelerator (HRA)</td><td> (73.23)</td><td> (73.23)</td>
<td>Fiberglass</td><td> 0.27 (9.76)</td><td> 0.28 (9.76)</td>
<td>Paper fiber</td><td> 0</td><td> 0.99 (34.17)</td>
<td>Soap*</td><td> 0.03 (0.937)</td><td> 0.03 (0.937)</td>
<td>Total water (kg)</td><td> 364.66</td><td> 385.95</td>
<td>Stucco / water ratio</td><td> 1.10</td><td> 1.21</td>
'used to generate foam <sup>1</sup> 1.28 percent by weight, as a 45 percent aqueous solution.
Example 2
Preparation of wall boards
Gypsum wall boards, as samples, were prepared in accordance with US Patent Nos. 6,342,284 to Yu and Co-inventors, and 6,632,550 to Yu and Co-inventors, incorporated herein by reference. This includes separate generation of the foam and introduction of the foam into the slurry from all other ingredients, as described in Example 5 of those patents.
The test results for the and so wall boards, made using formulations A and B of Example 1, as well as the normal control board, are shown in Table 2 below.
<img file="MX360873B_D0027.tif" />
IMPI <sup>, NST</sup>f [y7<sup>or</sup> Mexican OF THE INDUSTRIAL ROPIER
As in this example and in all other examples that follow, were nail resistance tests carried out?
core strength and flexural strength, in accordance with ASTM C
473. Additionally, it is noteworthy that the typical gypsum wall board is approximately 1.27 cm thick and has a weight of around 1600 and 1800 pounds per 1000 square feet of material or pounds / MSF (7,811.2 and 8,787.6 g / m<sup>2</sup>). ("MSF" is a standard abbreviation in the thousand-square-foot technique; it is an area measurement for boxes, corrugated media, and wall boards.)
Table 2
<td>Laboratory test result</td><td>Control panel</td><td>Formulation board A</td><td>Formulation board B</td>
<td>Board weight g / m<sup>2</sup></td><td> 7,747.7</td><td> 5,204.2</td><td> 5,087.0</td>
<td>Nail insertion resistance (kg)</td><td> 37.01</td><td> 22.74</td><td> 32.97</td>
<td>Core hardness (kg)</td><td> 7.38</td><td> 2.35</td><td> 5.25</td>
<td>Humidified joint load (kg)</td><td> 7.83</td><td> 9.19</td><td> 6.84</td>
<td>Humidified bond failure (%)</td><td> 0.6</td><td> 5</td><td> 11.1</td>
<td>Flexural strength; top face (MD) (kg)</td><td> 21.29</td><td> 21.38</td><td> 23.82</td>
<td>Flexural strength, underside (MD) (kg)</td><td> 23.32</td><td> 30.21</td><td> 35.69</td>
<td>Flexural strength, top face (XMD) (kg)</td><td> 67.95</td><td> 61.56</td><td> 78.41</td>
<td>Flexural strength, underside (XMD) (kg)</td><td> 65.41</td><td> 56.85</td><td> 74.92</td>
IMPI <sup>, NST |</sup>1WO MEXíCANC oe THE INDUSTRIAL PROPERTY
<img file="MX360873B_D0028.tif" />
drywall boards,
MD = machine address
XMD = machine cross direction As illustrated in Table 2, preparations using the slurries of Formulation A and Formulation B have significant reductions in weight, compared to the control board. Referring again to Table 1, the comparisons of the Formulation A board to the Formulation B board are more notable. The water / stucco ratios (w / s) are similar in Formulation A and Formulation B. A significantly higher level of dispersing naphthalenesulfonate is also used in Formulation B. Substantially more pregelatinized starch, about 6 percent by weight, was also used in Formulation B, an increase of more than 100 percent over Formulation A, accompanied by marked increases in strength. Even so, the water demand to produce the required flow capacity remained low in the suspension of formulation B, the difference being approximately 10 percent, compared to formulation A. The low water demand in both formulations is attributed to the synergistic effect of the combination of the dispersing naphthalenesulfonate and the sodium trimetaphosphate of the gypsum slurry, which increases the fluidity of the gypsum slurry, resulting in the presence of a substantially higher level of starch. pregelatinized.
As illustrated in Table 2, the wall board prepared using the grout from Formulation B has substantially strength
IMPI
MEXICAN INSTITUTE OF PROPUDAF Industrial
<img file="MX360873B_D0029.tif" />
increased compared to wall board prepared using slurry of formulation A. When increasing amounts of pregelatinized starch are incorporated, in combination with increased amounts of dispersing naphthalenesulfonate and sodium trimetaphosphate, the resistance to nail introduction into the board of formulation B, improved by 45 percent over the formulation A board. Substantial increases in flexural strength were also observed <sup>in</sup> @ 1 board of formulation B, compared to the board of formulation A.
Example 3
Attempts to reduce the weight of 1.27 cm veso wall board
Other examples of gypsum wall board (boards C, D, and E), including grout formulations and test results, are shown in Table 3 below. The grout formulations in Table 3 include the main components of the grouts. Values in parentheses are expressed as a percentage by weight, based on the weight of the dry stucco.
Table 3
INSTITUTO MEXICANO DF LA ΡϋΟΕ (£ /) ΑΓ · INCN <rtlA¿
<td>Test formulation. Component / parameter</td><td>Control panel</td><td>Formulation Board C</td><td>labléfó fftr formulation D</td><td> TabtCTücte ~ formulation E</td>
<td>Dry stucco (g / m<sup>s</sup>)</td><td> 6,346.6</td><td> 6,253.8</td><td> 5,838.8</td><td> 5,233.7</td>
<td>Accelerator (g / m<sup>to</sup>)</td><td> 44.91</td><td> 44.91</td><td> 44.91</td><td> 44.91</td>
<td>DILOFLO<sup>1</sup> (g / m<sup>3</sup>)</td><td> 20.01 (0.32%)</td><td> 3954 (0.63%)</td><td> 39.54 (0.68%)</td><td> 39.54 (0.76%)</td>
<td>Regular starch (g / m<sup>3</sup>)</td><td> 27.33 (0.43%)</td><td> 0</td><td> 0</td><td> 0</td>
<td>Pregelatinized corn starch (g / m<sup>3</sup>)</td><td> 0</td><td> 48.82 (0.78%)</td><td> 48.82 (0.84%)</td><td> 48.82 (0.93%)</td>
<td>Sodium trimetaphosphate (g / m<sup>3</sup>)</td><td> 3.41 (0.05%)</td><td> 7.81 (0.12%)</td><td> 7.81 (0.13%)</td><td> 7.81 (0.15%)</td>
<td>Total water / stucco ratio (w / s)</td><td> 0.82</td><td> 0.82</td><td> 0.82</td><td> 0.84</td>
<td>Test formulation test results</td><td></td><td></td><td></td><td></td>
<td>Dry board weight (g / m<sup>3</sup>)</td><td> 7,864.9</td><td> 7,664.7</td><td> 7,083.7</td><td> 6,444.2</td>
<td>Nail insertion resistance (kg)</td><td> 35.0<sup>T</sup></td><td> 38.73</td><td> 34.97</td><td> 29.53</td>
<td><sup>T</sup> ASTM Standard: 34.88</td><td colspan="4">kg</td>
<sup>1</sup> DILOFLO is a 45 percent solution of naphthalenesulfonate in water.
As illustrated in Table 3, boards C, D, and E were made from a slurry that has substantially increased amounts of starch, DILOFLO dispersant, and sodium trimetaphosphate, compared to the control board (approximately an increase in double over the base percentage for starch and dispersant, and a double to triple increase for trimetaphosphate) while keeping the w / s ratio constant. However, the weight of the board was significantly reduced, and the resistance, when
IMPI '^ pTOMEX'CAN. ·
DEU PROFíEDAI industrial
<img file="MX360873B_D0030.tif" />
measured by resistance to introduction was not dramatically affected. Therefore, in this example of an embodiment of the invention, the new formulation (such as, for example, D-board) can provide more starch, formulated in a usable slurry, capable of flowing, while maintaining the same ratio w / s and adequate resistance.
Example 4
Veso wet cube strength test
Wet cube strength tests were performed using Southard CKS board stucco, available from United States Gypsum Corp., Chicago, Illinois, USA, and tap water, in the laboratory, to determine its compressive strength in damp. The following laboratory test procedure was used.
1000 g of stucco, 2 g of CSA and 1200 cc of tap water, at about 21 ° C, were used for each casting of wet gypsum. 20 g of pregelatinized starch (2.0 percent, based on the weight of the stucco) and 2 g of CSA (0.2 percent, based on the weight of the stucco, were first perfectly dry blended first in a plastic bag with the stucco, before mixing with a tap water solution containing both dispersing naphthalenesulfonate and sodium trimetaphosphate. The dispersant used was DILOFLO dispersant (1.0-2.0 percent, as indicated in Table 4). Variable amounts of sodium trimetaphosphate were also used, as indicated in Table 4.
The dry ingredients and the aqueous solution were initially combined in a laboratory Warning mixer, allowing the
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY
<img file="MX360873B_D0031.tif" />
mixture produced, for 10 seconds, and then the mixture was mixed, at low speed, for 10 seconds, in order to form the grout. The grouts thus formed were molded in 5.08 x cubic molds
5.08 x 5.08 cm. The molded cubes were then removed from the molds, weighed, and sealed in plastic bags to prevent moisture loss, before the compressive strength test was performed. The compressive strength of the wet cubes was measured using an ATS machine and recorded as the average in MPa. The results obtained were as follows: Table 4
<td>No. of test sample</td><td>Sodium trimetaphosphate, g (wt%, based on dry stucco)</td><td>DILOFLO<sup>1</sup> (wt% based on dry stucco)</td><td>Wet Bucket Weight (5.08x 5.08x5.08 cm), 9</td><td>Wet cube compressive strength, MPa</td>
<td>í 1</td><td> 0</td><td> 1.5</td><td> 183.57</td><td> 2.211</td>
<td> 2</td><td> 0.5 (0.05)</td><td> 1.5</td><td> 183.11</td><td> 2.459</td>
<td> 3</td><td> 1(0.1)</td><td> 1.5</td><td> 183.51</td><td> 2.480</td>
<td>4 i</td><td> 2 (0.2)</td><td> 1.5</td><td> 183.51</td><td> 2.487</td>
<td> 5</td><td> 4 (0.4)</td><td> 1.5</td><td> 183.65</td><td> 2.625</td>
<td><sup>6</sup></td><td> 10 (1.0)</td><td> 1.5</td><td> 183.47</td><td> 2.542</td>
<td> 7</td><td> 0</td><td> 1.0</td><td> 184.02</td><td> 2.377</td>
<td><sup>8</sup></td><td> 0. (0.05)</td><td> 1.0</td><td> 183.66</td><td> 2.404</td>
<td> 9</td><td> 1 (0.1)</td><td> 1.0</td><td> 183.93</td><td> 2.452</td>
<td> 10</td><td> 2 (0.2)</td><td> 1.0</td><td> 182.67</td><td> 2.521</td>
<td> 11</td><td> 4 (0.4)</td><td> 1.0</td><td> 183.53</td><td> 2.514</td>
<td> 12</td><td> 10(1.0)</td><td> 1.0</td><td> 183.48</td><td> 1.349</td>
<td> 13</td><td> 0</td><td> 2.0</td><td> 183.33</td><td> 2.377</td>
<td> 14</td><td> 0.5 (0.05)</td><td> 2.0</td><td> 184.06</td><td> 2.452</td>
<td> 15</td><td> 1 (0.1)</td><td> 2.0</td><td> 184.3</td><td> 2.501</td>
<td><sup>18</sup></td><td> 2 (0.2)</td><td> 2.0</td><td> 184.02</td><td> 2.501</td>
<td> 17</td><td> 4 (0.4)</td><td> 2.0</td><td> 183.5</td><td> 2.535</td>
<td> 18</td><td> 10 (1.0)</td><td> 2.0</td><td> 182.68</td><td> 2.335</td>
IMPI
MEXICAN INSTITUTE Dt THE INDUSTRIAL PROPERTY
<img file="MX360873B_D0032.tif" />
<sup>1</sup> DILOFLO is a 45 percent solution of naphthalenesulfonate in water
As illustrated in Table 4, samples 4-5, 10-11, and 17, having levels of sodium trimetaphosphate on the scale of approximately 0.12 to 0.4 percent, of the present invention generally provide superior strength. to the compression of the wet cube, compared to samples that have sodium trimetaphosphate outside that scale.
Example 5 Plant Production Tests of 1.27 cm Lightweight Veso Wall Boards
Other tests (test boards 1 and 2), including grout formulations, were carried out and the test results are shown in Table 5 below. The grout formulations in Table 5 include the main components of the grouts. Values in parentheses are expressed as a percentage by weight, based on the weight of the dry stucco.
Table 5
IMPI
MEXICAN OF THE INDUSTRIAL PROPERTY
<img file="MX360873B_D0033.tif" />
<td>Component / parameter of the test formulation</td><td>Control board 1</td><td>Test board 1, plant formulation</td><td>Control board 2</td><td>Tabletop — Test 2, Plant Formulation</td>
<td>Dry stucco (g / m<sup>2</sup>)</td><td> 6,385</td><td> 5,663</td><td> 5,916</td><td> 5,467</td>
<td><sup>:</sup> DILOFLO<sup>1</sup> (g / m<sup>2</sup>)</td><td> 29.19 (0.457%)</td><td> 38.95 (0.688%)</td><td> 35.05 (0.592%)</td><td> 43.88 (0.803%)</td>
<td>Regular starch (g / m<sup>2</sup>)</td><td> 24.41 (0.38%)</td><td> 0</td><td> 22.45 (0.38%)</td><td> 0</td>
<td>Pregelatinized corn starch (g / m<sup>2</sup>)</td><td> 9.76 (0.15%)</td><td> 48.82 (0.86%)</td><td> 12.20 (0.21%)</td><td> 43.93 (0.80%)</td>
<td>Sodium trimetaphosphate (g / m<sup>2</sup>)</td><td> 3.41 (0.05%)</td><td> 9.76 (0.17%)</td><td> 2.92 .· (0.05%)</td><td> 7.81 (0.14%)</td>
<td>Total water / stucco ratio (w / s)</td><td> 0.79</td><td> 0.77</td><td> 0.86</td><td> 0.84</td>
<td>Test formulation test results</td><td></td><td></td><td></td><td></td>
<td>Dry board weight (g / m<sup>2</sup>)</td><td> 7,903.9</td><td> 7,108.1</td><td> 7581.7</td><td> 7,044.7</td>
<td>Nail penetration resistance (kg)</td><td> 36.91<sup>T</sup></td><td> 37.32</td><td> 36.55</td><td> 36.42</td>
<td>Flexural strength, average (MD) (kg)</td><td> 18.92</td><td> 19.79</td><td> 20.29</td><td> 21.24</td>
<td>Flexural strength, average (XMD) (kg)</td><td> 60.74</td><td> 61.38</td><td> 66.13</td><td> 62.15</td>
<td>Humidified joint load<sup>2</sup>, average (kg)</td><td> 8.69</td><td> 8.01</td><td> 946</td><td> 8.65</td>
<td>Humidified bond failure<sup>2,3</sup> (%)</td><td> 1.6</td><td> 0.1</td><td> 0.5</td><td> 0</td>
<sup>+</sup> ASTM Standard: 34.88 kg.
MD - machine direction
XMD = Cross direction to machine <sup>1</sup> DILOFLO is a 45 percent solution of naphthalenesulfonate in water.
<sup>2</sup> 32 'C / 90 percent relative humidity
<img file="MX360873B_D0034.tif" />
<sup>3</sup> It is well understood that under these test conditions percentage failure rates less than 50 percent are acceptable.
As illustrated in Table 5, Test Boards 1 and 2 were made from a slurry that has substantially increased amounts of starch, DILOFLO dispersant, and sodium trimetaphosphate, along with a slight decrease in the ratio w / s, compared to dashboards. However, the resistance measured by mqdio of the resistance to the introduction of nails, and the flexural test were maintained or improved, and the weight of the board was significantly reduced. Therefore, in this example of an embodiment of the invention, the new formulation (such as, for example, test boards 1 and 2) can provide more trimetaphosphate and formulated starch in a usable, flowable slurry, to the same while maintaining substantially the same ratio w / s and adequate resistance.
Example 6
In-plant production tests of veso wall panels, ultra-light weight, 1.27 cm
Other tests (test boards 3 and 4) were carried out using formulation B (example 1) as in example 2, except that the pregelatinized corn starch was prepared with water, at a concentration of 10 percent (preparation of wet starch) and a blend of HYONIC 25 AS and PFM 33 soaps (available from GEO Specialty Chemicals, Lafayette, Indiana, USA). For example, analysis board 3 was prepared with a mixture of HYONIC 25 AS and
IMPI
PFM 33, ranging from 65 to 70 weight percent ae ^ zSA
<img file="MX360873B_D0035.tif" />
PFM33. For example, the dash board was prepared ^^ on-a-mix
70/30 w / w of HYONIC 25AS / HONIC PFM 33. The results of the test are shown in Table 6 below.
Table 6
<td>Laboratory test results</td><td>Test board 3 (mixture of formulation B plus HYONIC soap (65/35) (n = 12)</td><td>Test board 4 (mixture of formulation B plus HYONIC 70/30 soap) (n = 34) *</td>
<td>Board weight (g / m<sup>2</sup>)</td><td> 5,399</td><td> 4,945</td>
<td>Nail penetration resistance<sup>8</sup> (kg)</td><td> 38,73</td><td> 36.37</td>
<td>Core hardness<sup>b</sup> (kg)</td><td> >6.79</td><td> 5.61</td>
<td>Flexural strength, average<sup>0</sup> (MD) (kg)</td><td> 25.18</td><td> 27.31’</td>
<td>Flexural strength<sup>0</sup>, average (XMD) (kg)</td><td> 63.46</td><td> 64.46’</td>
* Except as marked.
MD = machine address
XMD = cross direction to machine <sup>8</sup> ASTM 34.88 kg.
<sup>6</sup> ASTM Standard 4.98 kg <sup>c</sup> ASTM Standard 16.30 kg <sup>d</sup> ASTM Standard 40.47 kg.
As illustrated in Table 6, the strength characteristics, when measured by the insertion of nails and the hardness of
MEXICAN INSTITUTE fS & wGÍsJJÍ
PROPERTY J «3 core, were above ASTM standard. <sup>, NC</sup>PffPM5ién ^? 3 cold flexural strength, which was above the new ASTM Pr standard, in this example of an embodiment of the invention, the new formulation (such as, for example, test boards 3 and 4) can provide increased trimetaphosphate and starch, formulated in a usable, flowable slurry while maintaining adequate strength.
Example 7
Calculation of the percentage of hollow volume in the core of the back wall board, 1.27 cm thick, as a function of the weight of the board, and results of the saw cut.
Tests were carried out to determine the void volumes and densities (test boards No. 5 to 13, using Formulation B (Example 1), as in Example 2, except that the Corn starch pregelatinized with water at a concentration of 10 percent (wet preparation of the starch), 0.5 percent fiberglass was used and naphthalenesulfonate (DILOFLO) was used at a level of 1.2 percent by weight, as a 45% aqueous solution. percent. The soap foam was formed using a soap foam generator, and introduced into the gypsum grout in an amount effective to provide the desired densities. In the present example, soap was used at a level of 0.25 Ib / MSF to 0.45 Ib / MSF (1.22 to 2.19 g / m<sup>2</sup>). That is, the use of soap suds was increased or increased, as appropriate. In each sample the thickness of the wall board was assumed to be 1.27 cm and the core volume was uniform at 39.1 ft<sup>3</sup>/ SPS (11.91 cm<sup>3</sup>/ m<sup>2</sup>).
IMPI MEXICAN PROPERTY FEATURE Volumes'TOé'ttiós were measured
<img file="MX360873B_D0036.tif" />
4-foot wall board samples (1.20 m and front and backing papers removed. Front and backing papers may be within 11 to 18 mil (0.27mm to 0.457mm) thick (on each side) Hollow volumes / pore sizes and pore size distribution were determined by scanning electron microscopy (see Example 8 below) and X-ray CT scanning technology (XMT).
Table 7
<td>Test board No.</td><td>Board weight (g / m *)</td><td>Hollow foam volume<sup>1 </sup>(cm '/ m<sup>2</sup>)</td><td>Foam pore size distribution (% f</td><td>Hollow eva porative volume<sup>2 </sup>(cnP / m<sup>2</sup></td><td>Evaporative pore size distribution (%)<sup>T</sup></td><td>Total core void volume<sup>3 </sup>(%)</td><td>Board core density (g / dm<sup>3</sup>)<sup>4</sup></td>
<td> 5</td><td>780.8- 829.6 (control)</td><td> 4.57</td><td> 54</td><td> 3.86</td><td> 46</td><td>7C.8</td><td> 624-656</td>
<td> 6</td><td> 683.2</td><td> 5.97</td><td> 66</td><td> 3.13</td><td> 34</td><td> 76.5</td><td> 644.3</td>
<td> 7</td><td> 634.4</td><td> 6.42</td><td> 69</td><td> 2.86</td><td> 31</td><td> 780</td><td> 496.3</td>
<td> 8</td><td> 585.6</td><td> 6.36</td><td> 65</td><td> 3.38</td><td> 35</td><td> 81.8</td><td> 368.2</td>
<td> 9</td><td> 536.8</td><td> 6.42</td><td> 67</td><td> 3.16</td><td> 33</td><td> 80.6</td><td> 416.2</td>
<td> 10</td><td> 488.0</td><td> 6.36</td><td> 65</td><td> 3.38</td><td> 35</td><td> 81.8</td><td> 368.2</td>
<td> 11</td><td> 439.2</td><td> 7.12</td><td> 71</td><td> 2.89</td><td> 29</td><td> 84.1</td><td> 336.2</td>
<td> 12</td><td> 390.4</td><td> 7.76</td><td> 76</td><td> 2.46</td><td> 24</td><td> 85.9</td><td> 288.1</td>
<td> 13</td><td> 244.0</td><td> 4.59</td><td> 88</td><td> 1.37</td><td> 12</td><td> 92.1</td><td> 160.1</td>
'Air gaps (bubbles) of> 10 microns.
<sup>2</sup> Water holes <5 microns.
IMPI
INSTITUTO MEXICANO JR ~ de la noKEOAD Qb »J¡Uf <sup>3</sup> Based on uniform core volume = 39.1 ft'WféF, esniicir, total core void volume = · tiuwcc'tte'wpurrrar volume * * · evaporative void volume / 39.1 x 100.
<sup>4</sup> Based on uniform core volume = 39.1 ft '/ MSF, i.e., board core density (g / dm<sup>3</sup>) = board weight (g / m<sup>2</sup>) - weight of paper cover sheets (g / m<sup>z</sup>) / 39.1 ft<sup>3</sup>/ SPS = Board weight (g / m<sup>2</sup> - 90 lb / MSF / 39.1 ft<sup>3</sup>/ MSF.
<sup>F</sup> Percentage of total gaps measured.
As illustrated in Table 7, test board samples were prepared that have total core void volumes ranging from 79.0 percent to 92.1 percent, corresponding to board core densities ranging from 28 pcf (448.2 g / dm<sup>3</sup>) up to 10 pcf (160.1 g / dm<sup>3</sup>), respectively. As an example, a saw cut of test board 10, which has a total core void volume of 81.8 percent and a board core density of 23 pcf 368 g / dm<sup>3</sup>), generated around 30 percent less dust than the control board. As a further example, if conventionally formulated wall boards, having less binder (such as starch, with or without dispersant) that had significantly less than about 75 to 80 percent total hollow core volume, were formed Expect significantly more dust generation to occur when cutting, sawing, tearing, marking / chipping, nailing or screwing, or drilling. For example, conventional wall boards can generate dust fragments when cut with a saw, which have an average diameter of 20 to 30 microns, and a
<img file="MX360873B_D0037.tif" />
minimum diameter of 1 miera.
MEXICAN INSTITUTE
In contrast, the tablero ^ W,? ^ Jro of the present invention will generate poiyg fragments, when sawn, having an average diameter of about 30 to 50 microns and a minimum diameter of about 2 microns; marking / hitting will produce even larger fragments.
The combination of several key components used to form gypsum-containing grout, i.e. stucco, dispersing naphthalenesulfonate, pregelatinized corn starch, sodium trimetaphosphate, and glass and / or paper fibers, has been shown to be combined with a Sufficient and effective amount of soap suds, it can have a synergistic effect to produce a low density gypsum wall board, Dramatically reduces the formation of gypsum dust during cutting, sawing, starting, marking / hitting, nailing or screwing, or drilling operations and normal board handling.
Example 8
Determination of the sizes of the water bubble voids and the sizes of the water voids, on test board No. 10, and the morphology of the veso glass.
Gypsum cubes (5.08 x 5.08 x 5.08 cm) from the plant test to prepare Test Board No. 10 were analyzed by scanning electron microscopy (SEM). Air bubble voids and water evaporation voids were observed and measured, as well as the size and shape of the gypsum crystal.
Three sample cubes were formed and marked 11.08, 11.30 and
11.50, respectively. Figures 1 to 3 illustrate gap sizes
IMPI
MEXICAN INSTITUTE OF THE MKWEOAr.
of air bubble and its distribution for each sample'SYá'b'na'l
<img file="MX360873B_D0038.tif" />
15X. Figures 4 to 6 illustrate the air sizes & xde-buxhuj.a_ of air and their distribution for each sample, at a magnification of 50X.
At larger magnifications, the water gaps, for example, in the hollow walls of the air bubble were observed, generally substantially larger, as shown in Figures 7 to 10, for I sample 11:50 cube, up to 10,000X magnification. Most of the plaster crystals were needles; few platelets were observed. The density and packing of the needles varied on the surfaces of the air bubble voids. Plaster needles were also observed in the water gaps that were in the walls of the air bubble gap.
The SEM results demonstrate that in gypsum-containing products made in accordance with the present invention, air and water voids are generally evenly distributed throughout the set gypsum core. The observed void sizes and void distributions demonstrate that sufficient free space is formed as air and water voids (total core void volume) so that a substantial amount of the gypsum dust produced in the surrounding voids will be captured exposed when operating the board normally and during cutting, sawing, starting, marking / striking, nailing or screwing, or drilling operations, and are not floating in the air.
Example 9
IMPI
MEXICAN INSTITUTE
Dust capture on the board of mur5<sup>THE</sup>WT ^ ko ^ ®5lwja powder production.
If a wall board was prepared in accordance with the teachings of the present invention as in Example 7, it is expected that the gypsum powder produced by working the wall board will comprise at least 50 percent by weight of fragments of yes more than about 10 microns in diame ter. At least about 30 percent or more of the total dust generated by working the wall board would be captured by cutting, sawing, tearing, marking / hitting, nailing or screwing, and drilling operations.
The use of the terms "un, uno," una and "el" la "," los "," las and similar references in the context of the description of the invention (especially in the context of the claims that follow ) should also be considered as covering both singular and plural, unless otherwise indicated here, or clearly contradicted by context. The expression of value scales herein is intended merely to serve as a shorthand method to refer individually to each separate value that falls within the scale, unless otherwise indicated herein; and each separate value is incorporated in the description as if it had been individually cited here. All methods described herein may be carried out in any suitable order, unless otherwise indicated herein, or there is a clear contradiction to context. The use of any and all of the examples, or the exemplification language (eg, "as is") provided herein, is intended merely to better illuminate the invention, and not
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL HtOHEDAD
<img file="MX360873B_D0039.tif" />
It imposes no limitation on the scope of the invention, unless otherwise claimed. No language used in the description should be construed as indicating any element not claimed which is essential to the practice of the invention.
The preferred embodiments of this invention are described herein, including the best way known to inventors to practice the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be construed as limitations on the scope of the invention.
Contents44
44 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12 Sheet 13 Sheet 14 Sheet 15 Sheet 16 Sheet 17 Sheet 18 Sheet 19 Sheet 20 Sheet 21 Sheet 22 Sheet 23 Sheet 24 Sheet 25 Sheet 26 Sheet 27 Sheet 28 Sheet 29 Sheet 30 Sheet 31 Sheet 32 Sheet 33 Sheet 34 Sheet 35 Sheet 36 Sheet 37 Sheet 38 Sheet 39 Sheet 40 Sheet 41 Sheet 42 Sheet 43 Sheet 44
297 members in 26 offices
Priority claims9
| Document | Office | Kind | Date |
|---|---|---|---|
| 11592481 | United States of America | – | |
| 59248106 | United States of America | A | |
| 59248106 | United States of America | A | |
| 2007021573 | United States of America | W | |
| 2007021573 | United States of America | W | |
| 11592481 | – | – | – |
| PCTUS2007021573 | – | – | – |
| US20060592481 | – | – | – |
| WO2007US21573 | – | – | – |
Members297
| Document | Office | Kind | |
|---|---|---|---|
| US2006278132A1 | United States of America | A1 | |
| US2006278133A1 | United States of America | A1 | |
| AU2006258027A1 | Australia | A1 | |
| AU2006258110A1 | Australia | A1 | |
| CA2607884A1 | Canada | A1 | |
| CA2607896A1 | Canada | A1 | |
| CA2816891A1 | Canada | A1 | |
| WO2006135613A2 | World Intellectual Property Organization (WIPO) | A2 | |
| WO2006135707A2 | World Intellectual Property Organization (WIPO) | A2 | |
| TW200708494A | Taiwan Province of China | A | |
| US2007048490A1 | United States of America | A1 | |
| US2007059513A1 | United States of America | A1 | |
| TW200710059A | Taiwan Province of China | A | |
| AR053623A1 | Argentina | A1 | |
| AR054389A1 | Argentina | A1 | |
| WO2006135707A3 | World Intellectual Property Organization (WIPO) | A3 | |
| WO2006135613A3 | World Intellectual Property Organization (WIPO) | A3 | |
| NO20075704L | Norway | L | |
| NO20075705L | Norway | L | |
| CL2007002746A1 | Chile | A1 | |
| IL187019A0 | Israel | A0 | |
| IL187019D0 | Israel | D0 | |
| IL187020A0 | Israel | A0 | |
| IL187020D0 | Israel | D0 | |
| MX2007014355A | Mexico | A | |
| MX2007015522A | Mexico | A | |
| KR20080017458A | Republic of Korea | A | |
| EP1893374A2 | European Patent Office (EPO) | A2 | |
| EP1893375A2 | European Patent Office (EPO) | A2 | |
| US2008070026A1 | United States of America | A1 | |
| AU2007302768A1 | Australia | A1 | |
| CA2665092A1 | Canada | A1 | |
| WO2008042060A1 | World Intellectual Property Organization (WIPO) | A1 | |
| US2008090068A1 | United States of America | A1 | |
| KR20080044231A | Republic of Korea | A | |
| CN101189126A | China | A | |
| AU2007322350A1 | Australia | A1 | |
| CA2668086A1 | Canada | A1 | |
| WO2008063295A2 | World Intellectual Property Organization (WIPO) | A2 | |
| CN101203345A | China | A | |
| TW200829428A | Taiwan Province of China | A | |
| TW200835663A | Taiwan Province of China | A | |
| ZA200709397B | South Africa | B | |
| ZA200709399B | South Africa | B | |
| WO2008063295A3 | World Intellectual Property Organization (WIPO) | A3 | |
| JP2008543704A | Japan | A | |
| JP2008543705A | Japan | A | |
| AR063772A1 | Argentina | A1 | |
| CA2700401A1 | Canada | A1 | |
| WO2009045948A1 | World Intellectual Property Organization (WIPO) | A1 | |
| CA2703358A1 | Canada | A1 | |
| WO2009058558A1 | World Intellectual Property Organization (WIPO) | A1 | |
| TW200920712A | Taiwan Province of China | A | |
| TW200922775A | Taiwan Province of China | A | |
| KR20090061077A | Republic of Korea | A | |
| CL2008002928A1 | Chile | A1 | |
| CL2008003214A1 | Chile | A1 | |
| RU2007145441A | Russian Federation | A | |
| RU2007145428A | Russian Federation | A | |
| EP2081763A1 | European Patent Office (EPO) | A1 | |
| HRP20090214A2 | Croatia | A2 | |
| CN101528457A | China | A | |
| EP2101993A2 | European Patent Office (EPO) | A2 | |
| CN101563220A | China | A | |
| MX2009004680A | Mexico | A | |
| AR068668A1 | Argentina | A1 | |
| KR20090125746A | Republic of Korea | A | |
| IL197905A0 | Israel | A0 | |
| IL197905D0 | Israel | D0 | |
| AR069160A1 | Argentina | A1 | |
| IL198498A0 | Israel | A0 | |
| IL198498D0 | Israel | D0 | |
| ZA200902851B | South Africa | B | |
| JP2010509162A | Japan | A | |
| MX2010003007A | Mexico | A | |
| MX2010004015A | Mexico | A | |
| US7731794B2 | United States of America | B2 | |
| US2010139528A1 | United States of America | A1 | |
| US7736720B2 | United States of America | B2 | |
| CO6170347A2 | Colombia | A2 | |
| CO6180458A2 | Colombia | A2 | |
| EP2209617A1 | European Patent Office (EPO) | A1 | |
| BRPI0610882A2 | Brazil | A2 | |
| EP2212105A1 | European Patent Office (EPO) | A1 | |
| UA91856C2 | Ukraine | C2 | |
| US2010239886A1 | United States of America | A1 | |
| CN101848806A | China | A | |
| CN101855067A | China | A | |
| BRPI0612051A2 | Brazil | A2 | |
| RU2009114803A | Russian Federation | A | |
| RU2009119413A | Russian Federation | A | |
| AR074030A1 | Argentina | A1 | |
| JP2010540400A | Japan | A | |
| JP2011502094A | Japan | A | |
| EP2101993A4 | European Patent Office (EPO) | A4 | |
| RU2414440C2 | Russian Federation | C2 | |
| NZ562915A | New Zealand | A | |
| NZ562916A | New Zealand | A | |
| CO6270349A2 | Colombia | A2 | |
| NZ576663A | New Zealand | A |
Numbers
- Publication
- 360873
- Publication, DOCDB
- 360873
- Publication, EPODOC
- MX360873
- Application
- 2013009055
- Application, DOCDB
- 2013009055
- Application, EPODOC
- MX20130009055
Titles
- Spanish
- TABLEROS Y FANGOS DE YESO DE PESO LIGERO Y METODOS PARA ELABORARLOS.
Classification
- CPC, 32
- C04B28/14
- B32B1/00
- B32B13/02
- B32B13/04
- B32B13/08
- B32B13/14
- B32B17/02
- B32B29/00
- B32B2250/40
- B32B2307/306
- B32B2307/536
- B32B2307/546
- B32B2307/5825
- B32B2419/04
- B32B2607/00
- C04B2103/0075
- C04B2111/0062
- C04B2201/20
- Y10T428/232
- Y02W30/91
- C04B14/42
- C04B18/241
- C04B22/16
- C04B24/08
- C04B24/226
- C04B24/383
- C04B38/0054
- C04B38/0061
- C04B38/10
- C04B2103/408
- E04C2/04
- E04F13/14
- IPC, 4
- B32B1 04
- C04B16 08
- B32B1 00
- C04B28 14