Process for transporting, storing, and producing a particulate water-absorbent resin

• US 20010011123A1
• Filed: 01/04/2001
• Published: 08/02/2001
• Est. Priority Date: 01/20/2000
• Status: Active Grant

• Current Assignee: Nippon Shokubai Company Limited
• Original Assignee: Nippon Shokubai Company Limited
• Inventors: Maruo, Tatsuo, Kakita, Hiroyuki, Irie, Yoshio, Hatsuda, Takumi
• Granted Patent: US 6,817,557 B2
• Time in Patent Office: Days
• US Class Current: 528/503
• CPC Class Codes: C08J 2300/14 Water soluble or water swellable polymers, e.g. aqueous gels
• CPC Class Codes: C08J 3/12 Powdering or granulating

Abstract

The present invention provides: a process for treating a particulate water-absorbent resin, which enables to carry out pulverization stably in a process for producing a particulate water-absorbent resin, and transportation or storage of the particulate water-absorbent resin stably during or after producing the particulate water-absorbent resin, and to prevent contamination of cohered matters of the particulate water-absorbent resin; and involves no or little deterioration of properties. The process for treating a particulate water-absorbent resin is characterized by carrying out at least one selected from the group consisting of: (1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside, (2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150° C., and (3) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin above a temperature that is lower than a temperature of the particulate water-absorbent resin by 20° C.

Claims

1. A process for transporting a particulate water-absorbent resin, which comprises a step of transporting a particulate water-absorbent resin obtained by pulverizing a dry water-absorbent resin product,

with the process being characterized by carrying out at least one selected from the group consisting of:

(1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside,

(2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150°

C., and

(3) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin above a temperature that is lower than a temperature of the particulate water-absorbent resin by 20°

C.,

when transporting the particulate water-absorbent resin.

2. A process for transporting a particulate water-absorbent resin according to

claim 1

, wherein the particulate water-absorbent resin is a surface-crosslinked particulate water-absorbent resin.

3. A process for transporting a particulate water-absorbent resin according to

claim 2

, wherein the surface-crosslinked particulate water-absorbent resin contains at least a polyhydric alcohol.

4. A process for transporting a particulate water-absorbent resin according to

claim 2

, wherein the absorption capacity of the surface-crosslinked particulate water-absorbent resin under a load is not less than 18 g/g.

5. A process for transporting a particulate water-absorbent resin according to

claim 1

, wherein the particulate water-absorbent resin is a crosslinked partially-neutralized polycarboxylic acid salt.

6. A process for transporting a particulate water-absorbent resin according to

claim 1

, wherein the dry water-absorbent resin product is a dry product obtained by drying at 160 to 250°

C.

7. A process for storing a particulate water-absorbent resin, which comprises a step of storing a particulate water-absorbent resin obtained by pulverizing a dry water-absorbent resin product,

with the process being characterized by carrying out at least one selected from the group consisting of:

(1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside,

(2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150°

C., and

(3) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin above a temperature that is lower than a temperature of the particulate water-absorbent resin by 20°

C.,

when storing the particulate water-absorbent resin.

8. A process for storing a particulate water-absorbent resin according to

claim 7

, wherein the particulate water-absorbent resin is a surface-crosslinked particulate water-absorbent resin.

9. A process for storing a particulate water-absorbent resin according to

claim 8

, wherein the surface-crosslinked particulate water-absorbent resin contains at least a polyhydric alcohol.

10. A process for storing a particulate water-absorbent resin according to

claim 8

, wherein the absorption capacity of the surface-crosslinked particulate water-absorbent resin under a load is not less than 18 g/g.

11. A process for storing a particulate water-absorbent resin according to

claim 7

, wherein the particulate water-absorbent resin is a crosslinked partially-neutralized polycarboxylic acid salt.

12. A process for storing a particulate water-absorbent resin according to

claim 7

, wherein the dry water-absorbent resin product is a dry product obtained by drying at 160 to 250°

C.

13. A process for producing a particulate water-absorbent resin, which comprises a step of pulverizing a dry water-absorbent resin product in order to obtain a particulate water-absorbent resin in part of the entire steps,

with the process being characterized by carrying out at least one selected from the group consisting of:

(1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside,

(2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150°

C., and

(3) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin above a temperature that is lower than a temperature of the particulate water-absorbent resin by 20°

C.,

in the step of pulverizing.

14. A process for producing a particulate water-absorbent resin according to

claim 13

, wherein the particulate water-absorbent resin is a crosslinked partially-neutralized polycarboxylic acid salt.

15. A process for producing a particulate water-absorbent resin according to

claim 13

, wherein the dry water-absorbent resin product is a dry product obtained by drying at 160 to 250°

C.