IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0675364
(2008-08-27)
|
등록번호 |
US-8188163
(2012-05-29)
|
우선권정보 |
JP-2007-221473 (2007-08-28) |
국제출원번호 |
PCT/JP2008/065332
(2008-08-27)
|
§371/§102 date |
20100225
(20100225)
|
국제공개번호 |
WO2009/028568
(2009-03-05)
|
발명자
/ 주소 |
- Matsumoto, Makoto
- Takaai, Toshihiro
- Dairoku, Yorimichi
- Fujino, Shinichi
- Matsumoto, Satoshi
- Kato, Seiji
|
출원인 / 주소 |
- Nippon Shokubai Co., Ltd.
|
대리인 / 주소 |
Roylance, Abrams, Berdo & Goodman, L.L.P.
|
인용정보 |
피인용 횟수 :
6 인용 특허 :
30 |
초록
▼
A water absorbent resin is dried in a continuous fluidized bed having a heat transfer tube and at least two drying rooms. Pulverization is performed between a first drying room at not less than 80° C. to not more than 200° C. and a second or subsequent room at not less than 100° C. to not more than
A water absorbent resin is dried in a continuous fluidized bed having a heat transfer tube and at least two drying rooms. Pulverization is performed between a first drying room at not less than 80° C. to not more than 200° C. and a second or subsequent room at not less than 100° C. to not more than 220° C. A method for producing a water absorbent resin includes: (1) polymerizing a monomer aqueous solution; (2) drying a hydrogel polymer of step (1); (3) performing particle size control of the dry polymer of the step (2); (5) surface crosslinking the water absorbent resin powder of step (3), and step (4) of performing a second heat drying on the water absorbent resin powder of step (3), preceding step (5). The water absorbent resin has a moisture content of 0 wt % to 3 wt % before the step (5).
대표청구항
▼
1. A method for producing a polyacrylate salt water absorbent resin with use of a continuous fluidized-bed dryer to heat or dry a particulate hydrous cross-linked polymer, the method comprising: performing cross-linking polymerization of an acrylic acid (salt) aqueous solution within a range of 10 w
1. A method for producing a polyacrylate salt water absorbent resin with use of a continuous fluidized-bed dryer to heat or dry a particulate hydrous cross-linked polymer, the method comprising: performing cross-linking polymerization of an acrylic acid (salt) aqueous solution within a range of 10 wt % to 90 wt % in a method of one selected from the group consisting of spraying polymerization, dropping polymerization, aqueous polymerization, and reversed-phase polymerization, to obtain a particulate hydrous cross-linked polymer,drying the particulate hydrous cross-linked polymer with use of a continuous fluidized-bed dryer having at least two drying rooms or with use of at least two continuous fluidized-bed dryers, to obtain water absorbent resin particles, each of the continuous fluidized-bed dryer containing a heat transfer tube in its fluidized bed; andsurface cross-linking the water absorbent resin particles. 2. The method as set forth in claim 1, wherein the fluidized bed has a floor-area ratio of not less than 3 to not more than 20 with respect to a surface area of the heat transfer tube. 3. The method as set forth in claim 1, wherein the continuous fluidized-bed dryer has at least three drying rooms. 4. The method as set forth in claim 1, further comprising drying with use of a continuous fluidized-bed dryer whose fluidized bed has a length-to-width ratio of not less than 2 to not more than 9 in a direction of movement of the fluidized bed. 5. The method as set forth in claim 1, wherein the continuous fluidized-bed dryer has a fluidized bed provided with a stepped floor. 6. The method as set forth in claim 1, wherein: the particulate hydrous cross-linked polymer is dried at a drying temperature of not less than 80° C. to not more than 200° C. in an early stage of the drying; andthe particulate hydrous cross-linked polymer is dried at a drying temperature of not less than 100° C. to not more than 220° C. in a later stage of the drying. 7. The method as set forth in claim 1, further comprising performing pulverization of a particulate hydrous cross-linked polymer once dried with the continuous fluidized-bed dryer and then further drying the particulate hydrous cross-linked polymer with the continuous fluidized-bed dryer. 8. A method for producing a water absorbent resin, comprising a sequence of the steps of: (1) polymerizing a monomer aqueous solution;(2) drying a hydrogel polymer obtained in the step (1);(3) performing particle size control by either pulverizing or pulverizing and classifying a dry polymer obtained in the step (2); and(5) performing surface crosslinking on water absorbent resin powder whose particle size has been controlled in the step (3),the method further comprising the step (4) of performing second heat drying on the water absorbent resin powder whose particle size has been controlled in the step (3), the step (4) preceding the step (5). 9. The method as set forth in claim 8, wherein the step (4) is performed for not shorter than 10 minutes at a temperature of 150° C. to 300° C. 10. The method as set forth in claim 8, wherein the water absorbent resin has a moisture content (defined by a loss on drying performed for three hours at 180° C.) of 0 wt % to 3 wt % before it is subjected to the step (5). 11. A method for producing a water absorbent resin, comprising a sequence of the steps of: (1) polymerizing a monomer aqueous solution;(2) drying a hydrogel polymer obtained in the step (1);(3) performing particle size control by either pulverizing or pulverizing and classifying a dry polymer obtained in the step (2); and(5) performing surface crosslinking on water absorbent resin powder whose particle size has been controlled in the step (3),the water absorbent resin having a moisture content (defined by a loss on drying performed for three hours at 180° C.) of 0 wt % to 3 wt % before it is subjected to the step (5). 12. The method as set forth in claim 11, further comprising the step (4) of performing second heat drying on the water absorbent resin powder whose particle size has been controlled in the step (3), the step (4) preceding the step (5). 13. The method as set forth in claim 11, wherein: the dry polymer obtained in the step (2) has a weight-average particle diameter (defined by sieve classification) of 1 mm to 5 mm; andthe water absorbent resin powder whose particle size has been controlled in the step (3) has a weight-average particle diameter (defined by sieve classification) of 200 μm to 800 μm. 14. The method as set forth in claim 11, wherein the hydrogel polymer has been granulated after or during polymerization. 15. The method as set forth in claim 12, further comprising using a fluidized-bed dryer for drying in the step (2) or (4). 16. The method as set forth in claim 11, wherein the water absorbent resin is a polyacrylate salt water absorbent resin that satisfies at least one of the following properties: (a) an absorption capacity without pressure (GV) with respect to 0.9 wt % sodium chloride aqueous solution, of 20 g/g to 100 g/g;(b) an absorbency against pressure (AAP) under a pressure of 0.7 Psi with respect to 0.9 wt % sodium chloride aqueous solution, falling within a range of not less than 10 g/g to not more than 28 g/g; and(c) a saline flow conductivity (SFC) of at least 10 (10−7·cm3·s·g−1). 17. The method as set forth in claim 8, wherein: the dry polymer obtained in the step (2) has a weight-average particle diameter (defined by sieve classification) of 1 mm to 5 mm; and the water absorbent resin powder whose particle size has been controlled in the step (3) has a weight-average particle diameter (defined by sieve classification) of 200 μm to 800 μm. 18. The method as set forth in claim 8, wherein the hydrogel polymer has been granulated after or during polymerization. 19. The method as set forth in claim 8, further comprising using a fluidized-bed dryer for drying in the step (2) or (4). 20. The method as set forth in claim 8, wherein the water absorbent resin is a polyacrylate salt water absorbent resin that satisfies at least one of the following properties: (a) an absorption capacity without pressure (GV) with respect to 0.9 wt % sodium chloride aqueous solution, of 20 g/g to 100 g/g;(b) an absorbency against pressure (AAP) under a pressure of 0.7 Psi with respect to 0.9 wt % sodium chloride aqueous solution, falling within a range of not less than 10 g/g to not more than 28 g/g; and(c) a saline flow conductivity (SFC) of at least 10 (10−7·cm3·s·g−1). 21. The method as set forth in claim 1, further comprising: scattering a small amount of fine particles contained in the particulate hydrous cross-linked polymer together with exhaust fumes passing through an interior of the fluidized bed, to remove the fine particles from the fluidized bed, the fine particles being particles of less than 150 μm in terms of a standard sieve; andcatching the fine particles by a cyclone and a bag filter. 22. The method as set forth in claim 1, wherein the particulate hydrous cross-linked polymer contains a solid content of not more than 90 wt %, the solid content being a contained solid content upon drying and reducing weight of the particulate hydrous cross-linked polymer at 180° C. for 3 hours, andthe water absorbent resin particles have a weight-average particle diameter falling within a range of 100 μm to 1000 μm. 23. The method as set forth in claim 1, further comprising; mixing a surface cross-linking agent into the water absorbent resin particles, the surface cross-linking agent being added by an amount falling within a range of 0.001 parts by weight to 10 parts by weight with respect to 100 parts by weight of the water absorbent resin particles; andmixing a liquid-permeability improver into the water absorbent resin particles into which the surface cross-linking agent has been mixed, the liquid-permeability improver being added by an amount falling within a range of 0.001 parts by weight to 5 parts by weight with respect to 100 parts by weight of the water absorbent resin particles. 24. The method as set forth in claim 23, wherein the liquid-permeability improver is selected from the group consisting of polyamines, polyvalent metal salts, and water-insoluble fine particles. 25. The method as set forth in claim 1, wherein the water absorbent resin is a polyacrylate salt water absorbent resin that satisfies the following three properties: (a) an absorption capacity without pressure (GV) with respect to 0.9 wt % sodium chloride aqueous solution, of 20 g/g to 100 g/g;(b) an absorbency against pressure (AAP) under a pressure of 0.7 Psi with respect to 0.9 wt % sodium chloride aqueous solution, falling within a range of not less than 10 g/g to not more than 28 g/g; and(c) a saline flow conductivity (SFC) of at least 10 (10−7·cm3·s·g−1). 26. A method for producing a polyacrylate salt water absorbent resin with use of a continuous fluidized-bed dryer to heat or dry a particulate hydrous cross-linked polymer, the method comprising: performing cross-linking polymerization of an acrylic acid (salt) aqueous solution within a range of 10 wt % to 90 wt % in a method of either spraying polymerization or dropping polymerization, to obtain a particulate hydrous cross-linked polymer;drying the particulate hydrous cross-linked polymer with use of a continuous fluidized-bed dryer having at least two drying rooms or with use of at least two continuous fluidized-bed dryers, to obtain water absorbent resin particles;scattering a small amount of fine particles contained in the particulate hydrous cross-linked polymer together with exhaust fumes passing through an interior of the fluidized bed, to remove the fine particles from the fluidized bed, the fine particles being particles of less than 150 μm in terms of a standard sieve;catching the fine particles by a cyclone and a bag filter;surface cross-linking the obtained water absorbent resin particles.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.