Vinyl alcohol polymer and production method thereof, additive for drilling mud, drilling mud, additive for drilling cement slurry, and drilling cement slurry

Patent metadata

Field	Value
Publication number	US-10118978-B2
Application number	US-201415021872-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Sep 13, 2013
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

Provided by the present invention is a vinyl alcohol polymer crosslinked by a structure represented by the following formula (1) and/or a disulfide structure, in which the vinyl alcohol polymer is not completely dissolved in a mixture prepared by: adding the vinyl alcohol polymer to water so as to give a concentration of 4% by mass; and stirring at 95° C. for 3 hrs. in the formula (1), R 1 , R 2 and R 3 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 8 or less carbon atoms. Also provided include an additive for a drilling mud containing the vinyl alcohol polymer, a drilling mud containing the vinyl alcohol polymer as an additive, an additive for a drilling cement slurry containing the vinyl alcohol polymer, and a drilling cement slurry containing the vinyl alcohol polymer as an additive.

First claim

The invention claimed is:

1. A vinyl alcohol polymer comprising molecular main chains crosslinked therebetween by a structure represented by formula (1), wherein the vinyl alcohol polymer is not completely dissolved in a mixture prepared by: adding the vinyl alcohol polymer to water so as to give a concentration of 4% by mass; and stirring at 95° C. for 3 hrs,

wherein R 1 , R 2 , and R 3 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 8 or less carbon atoms.

2. The vinyl alcohol polymer according to claim 1 , which is in a powdery form.

3. The vinyl alcohol polymer according to claim 2 , which passes through a 10-mesh sieve according to JIS.

4. The vinyl alcohol polymer according to claim 1 , which is the vinyl alcohol polymer comprising molecular main chains crosslinked therebetween by the structure represented by the formula (1), wherein the structure represented by the formula (1) is formed by a reaction of an epoxy group and a mercapto group.

5. A method of producing the vinyl alcohol polymer according to claim 4 , the method comprising:
reacting a first vinyl alcohol polymer comprising an epoxy group on a side chain thereof with a first compound comprising at least two mercapto groups per molecule.

6. A method of producing the vinyl alcohol polymer according to claim 4 , the method comprising:
reacting a second vinyl alcohol polymer comprising a mercapto group on a side chain thereof with a second compound comprising at least two epoxy groups per molecule.

7. The method according to claim 5 , wherein, in the reacting, a first vinyl ester polymer comprising an epoxy group on a side chain thereof is saponified in the presence of the first compound by using an alkali catalyst so as to allow a saponification reaction in a vinyl ester unit and a reaction of an epoxy group and a mercapto group to concomitantly proceed.

8. The method according to claim 6 , wherein in the reacting, a second vinyl ester polymer comprising a thioester group on a side chain thereof is saponified in the presence of the second compound by using an alkali catalyst so as to allow a saponification reaction in a vinyl ester unit and a reaction of the epoxy group with a mercapto group generated by the saponification reaction on the thioester group to concomitantly proceed.

9. An additive for a drilling mud comprising the vinyl alcohol polymer according to claim 1 .

10. A drilling mud comprising as an additive, the vinyl alcohol polymer according to claim 1 .

11. An additive for a drilling cement slurry comprising the vinyl alcohol polymer according to claim 1 .

12. A drilling cement slurry comprising as an additive, the vinyl alcohol polymer according to claim 1 .

Assignees

• Kuraray Co

Inventors

• Kumaki Yosuke
• Saito yasutomo

Classifications

• C04B2103/0055

  Water-insoluble polymers · CPC title

• C08F2810/50

  wherein the polymer is a copolymer and the modification is taking place only on one or more of the monomers present in minority · CPC title

• C04B2103/0062

  Cross-linked polymers · CPC title

• C08F8/34

  Introducing sulfur atoms or sulfur-containing groups · CPC title

• C08F216/06 Primary

  Polyvinyl alcohol {; Vinyl alcohol} · CPC title