Siloxane compositions and methods for reducing VOC and siloxane dust

Patent metadata

Field	Value
Publication number	US-10232588-B2
Application number	US-201414523016-A
Country	US
Kind code	B2
Filing date	Oct 24, 2014
Priority date	Apr 25, 2014
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

An improved water-resistant gypsum product prepared with a high-viscosity siloxane is provided. A fuel-efficient method for making the product and reducing the amount of siloxane dust released is provided as well.

First claim

What is claimed is:

1. A method of manufacturing a gypsum product, the method comprising:
preparing a gypsum slurry comprising a high-viscosity siloxane of 30 cps to 242 cps by mixing at least stucco, water, the high-viscosity siloxane, and at least one accelerator of siloxane polymerization;
forming the gypsum slurry into a gypsum core of a gypsum product;
allowing the gypsum slurry to set; and
drying the gypsum product in a kiln;
wherein a level of siloxane dust generated in the kiln during manufacturing the gypsum product is decreased by at least 10% in comparison to a gypsum product made with a low-viscosity siloxane of about 20 cps; and wherein the gypsum product is a gypsum-fiber board and the gypsum core of the gypsum-fiber board comprises at least one surface, and the method further comprises a step of coating a water-resistant coating on the at least one surface of the gypsum core.

2. The method of claim 1 , wherein the high-viscosity siloxane has viscosity from 60 cps to 80 cps.

3. The method of claim 1 , wherein the level of siloxane dust during manufacturing the gypsum product is decreased by at least 30%.

4. The method of claim 1 , wherein the gypsum slurry is sandwiched between two cover sheets during the step of forming.

5. The method claim 4 , wherein the cover sheets are paper sheets.

6. The method of claim 1 , wherein the gypsum product is selected from the group consisting of a panel, board, tile, and a ceiling tile.

7. The method of claim 1 , wherein the high-viscosity siloxane is methylhydrogen siloxane.

8. The method of claim 1 , wherein the accelerator of siloxane polymerization is magnesium oxide.

9. The method of claim 1 , wherein the water-resistant coating comprises potassium methyl siliconate.

Assignees

• United States Gypsum Co

Inventors

• Xu Yufeng
• Luan Wenqi

Classifications

• B32B2307/7265

  Non-permeable · CPC title

• B32B2250/40

  Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA · CPC title

• C04B2201/10

  for the viscosity · CPC title

• B32B2307/3065

  Flame resistant or retardant, fire resistant or retardant · CPC title

• C04B2111/00629

  the covering sheets being made of material other than paper · CPC title