Gypsum slurry, hardened gypsum, gypsum building material, gypsum board, method of producing gypsum slurry, method of producing hardened gypsum, method of producing gypsum building material, and method of producing gypsum board

Patent metadata

Field	Value
Publication number	US-9533916-B2
Application number	US-201415036462-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Nov 28, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A gypsum slurry includes calcined gypsum, urea phosphate esterified starch, organopolysiloxane, and water.

First claim

The invention claimed is:

1. A gypsum slurry, comprising: calcined gypsum; urea phosphate esterified starch; organopolysiloxane; and water.

2. The gypsum slurry as claimed in claim 1 , wherein an amount of the urea phosphate esterified starch in the gypsum slurry is greater than or equal to 0.05 parts by mass and less than or equal to 10 parts by mass with respect to 100 parts by mass of the calcined gypsum.

3. The gypsum slurry as claimed in claim 1 , wherein a gelatinization temperature of the urea phosphate esterified starch is less than or equal to 100° C.

4. The gypsum slurry as claimed in claim 1 , wherein the organopolysiloxane includes methylhydrogenpolysiloxane having a structure represented by the following formula (1):

5. A hardened gypsum obtained by hardening the gypsum slurry of claim 1 .

6. A gypsum building material comprising the hardened gypsum of claim 5 .

7. A gypsum board comprising the hardened gypsum of claim 5 .

8. A method of producing a gypsum slurry, the method comprising:
forming a gypsum composition by mixing calcined gypsum and urea phosphate esterified starch; and
forming the gypsum slurry by mixing the gypsum composition, organopolysiloxane, and water.

9. The method as claimed in claim 8 , wherein an amount of the urea phosphate esterified starch in the gypsum slurry is greater than or equal to 0.05 parts by mass and less than or equal to 10 parts by mass with respect to 100 parts by mass of the calcined gypsum.

10. The method as claimed in claim 8 , wherein a gelatinization temperature of the urea phosphate esterified starch is less than or equal to 100° C.

11. The method as claimed in claim 8 , wherein the organopolysiloxane includes methylhydrogenpolysiloxane having a structure represented by the following formula (1):

12. A method of producing a hardened gypsum, the method comprising:
molding the gypsum slurry produced by the method of claim 8 to produce a molded gypsum slurry.

13. The method as claimed in claim 12 , further comprising:
gelatinizing the urea phosphate esterified starch after molding the gypsum slurry.

14. The method as claimed in claim 13 , wherein the gelatinizing includes heating the molded gypsum slurry at a temperature less than or equal to 100° C.

15. A method of producing a gypsum building material comprising the method of producing the hardened gypsum of claim 12 .

16. A method of producing a gypsum board comprising the method of producing the hardened gypsum of claim 12 .

Assignees

• Yoshino Gypsum Co

Inventors

• Ataka Yuji
• Watanabe Ken

Classifications

• C04B24/28

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds {(C04B24/243 takes precedence)} · CPC title

• C04B2111/27

  Water resistance, i.e. waterproof or water-repellent materials · CPC title

• C04B24/243

  Phosphorus-containing polymers · CPC title

• C04B28/14 Primary

  containing calcium sulfate cements {(gypsum-paper plates E04C)} · CPC title

• C04B24/42

  Organo-silicon compounds · CPC title