Method for manufacturing superabsorbent resin

Abstract

The present invention relates to a method for producing a superabsorbent polymer and the superabsorbent polymer, and more specifically, to a method for producing a superabsorbent polymer that exhibits excellent water absorption properties and significantly reduces the amount of fine powder generated.

Claims

1. Step 1: Polymerization is carried out on a monomer composition comprising a water-soluble ethylene-based unsaturated monomer having an acidic group, an internal crosslinking agent, and a polymerization initiator to form a polymer in which the water-soluble ethylene-based unsaturated monomer having an acidic group and the internal crosslinking agent are crosslinked; Step 2: The polymer is ultra-finely pulverized at a rotational speed of 1,500 rpm to 4,000 rpm; Step 3: Neutralizing at least some of the acidic groups of the polymer; Step 4: Drying the ultrafinely ground and neutralized polymer to produce dried superabsorbent polymer particles; and The process includes a step (step 5) of crushing the dried superabsorbent resin particles to produce superabsorbent resin particles, A method for producing superabsorbent polymers.

2. The aforementioned step 1 is carried out in a batch-type reactor for at least one hour. A method for producing a superabsorbent resin according to claim 1.

3. The aforementioned step 2 is performed at a rotational speed of 1,500 rpm to 3,500 rpm. A method for producing a superabsorbent resin according to claim 1.

4. The aforementioned steps 2 and 3 may be performed sequentially, alternately, or simultaneously. A method for producing a superabsorbent resin according to claim 1.

5. The above step 3 is carried out by a high-shear grinding device, and the high-shear grinding device is A body section containing a transfer space into which polymer is transferred; A screw member rotatably installed inside the transfer space for moving the polymer; A drive motor that provides rotational driving force to the screw member; A cutter member installed in the body portion for crushing the polymer; and The polymer crushed by the cutter member is discharged to the outside of the body, and the body includes a porous plate in which numerous holes are formed. A method for producing a superabsorbent resin according to claim 1.

6. The size of the holes formed in the perforated plate is 1 mm to 25 mm. A method for producing a superabsorbent resin according to claim 5.

7. The aforementioned step 4 is carried out by fixed-bed type drying, moving type drying, or a combination thereof. A method for producing a superabsorbent resin according to claim 1.

8. If step 4 is performed by stationary drying, The drying is carried out at a temperature of 80°C to 200°C. A method for producing a superabsorbent resin according to claim 7.

9. If step 4 is performed using a fluidized bed drying method, The drying is carried out at a temperature of 100°C to 300°C. A method for producing a superabsorbent resin according to claim 7.

10. The water content of the dried superabsorbent resin particles obtained by step 4 is 1% by weight to 20% by weight. A method for producing a superabsorbent resin according to claim 1.

11. Prior to step 4, the process further includes an additive addition step in which one of the following additional additives, consisting of a polymerization initiator, a neutralizing agent, a surfactant, a fine powder, a fluidity enhancer, a solidification inhibitor, and an antioxidant, is mixed with the ultrafinely ground and neutralized polymer. A method for producing a superabsorbent resin according to claim 1.

12. The aforementioned additive addition step is Performed simultaneously with stage 2, simultaneously with stage 3, after stage 3, or at least one of these stages, A method for producing a superabsorbent resin according to claim 11.

13. The step further includes forming a surface crosslinking layer on at least a portion of the surface of the superabsorbent resin particles. A method for producing a superabsorbent resin according to claim 1 or 11.

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