KR-102964510-B1 - PREPARATION METHOD OF SUPER ABSORBENT POLYMER AND SUPER ABSORBENT POLYMER

KR102964510B1KR 102964510 B1KR102964510 B1KR 102964510B1KR-102964510-B1

Abstract

The present invention relates to a method for manufacturing a superabsorbent resin and a superabsorbent resin. More specifically, the invention relates to a method for manufacturing a superabsorbent resin and a superabsorbent resin capable of suppressing the generation of fine particles during the manufacturing process and simultaneously achieving an excellent absorption rate by controlling the process conditions of the drying step to produce a base resin powder with a relatively high moisture content.

Inventors

한상원
김기철
박세열
김태윤

Assignees

주식회사 엘지화학

Dates

Publication Date: 20260513
Application Date: 20220620
Priority Date: 20210618

Claims (14)

A step of forming a hydrogel polymer by crosslinking a water-soluble ethylene-based unsaturated monomer having an acidic group in the presence of an internal crosslinking agent and a polymerization initiator (Step 1-1); A step of neutralizing at least some of the acidic groups of the above-mentioned hydrogel polymer (step 1-2); A step of preparing a mixture comprising the micronized hydrogel polymer by micronizing the hydrogel polymer in the presence of a surfactant (Step 2); A step of drying the above mixture in a moving type at 100 ℃ to 250 ℃ to form a base resin powder having a moisture content of 10 wt% to 30 wt% (Step 3); and The method includes the step (step 4) of preparing superabsorbent resin particles by thermally crosslinking the surface of the base resin powder in the presence of a surface crosslinking agent, and The step of neutralizing at least some of the acidic groups of the above-mentioned hydrogel polymer (steps 1-2) and the step of micronizing the above-mentioned hydrogel polymer in the presence of a surfactant to prepare a mixture comprising the micronized hydrogel polymer (step 2) are performed sequentially or simultaneously. The above surfactant is one or more selected from the group consisting of compounds represented by the following chemical formula 1 and salts thereof, Method for manufacturing superabsorbent resin: [Chemical Formula 1] In the above chemical formula 1, A1 , A2 , and A3 are each independently single bonds, carbonyl, , or and, provided that one or more of these are carbonyl or and, where, m1, m2 and m3 are each independently integers from 1 to 8, and Each is connected to an adjacent oxygen atom, and is connected to adjacent R1 , R2 , and R3 , respectively, and R1 , R2, and R3 are each independently hydrogen, a straight-chain or branched-chain alkyl having 6 to 18 carbon atoms, or a straight-chain or branched-chain alkenyl having 6 to 18 carbon atoms, and n is an integer from 1 to 9.
In paragraph 1, The above-mentioned fluid drying step (step 3) is, The above mixture is fed into a fluidized dryer rotating at a speed of 30 rpm to 300 rpm and performed, Method for manufacturing a superabsorbent resin.
In paragraph 1, The above-mentioned fluid drying step (step 3) is, Performed using a fluid dryer of a horizontal-type mixer, rotary kiln, paddle dryer, or steam tube dryer, Method for manufacturing a superabsorbent resin.
In paragraph 1, The above-mentioned fluid drying step (step 3) is, Performed for 30 to 120 minutes, Method for manufacturing a superabsorbent resin.
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In paragraph 1, The step of micronizing the above-mentioned hydrogel polymer (step 2) is, The above-mentioned functional gel polymer is pushed into a porous plate having a plurality of holes formed therein, Method for manufacturing a superabsorbent resin.
In Paragraph 7, The hole size formed in the above porous plate is 0.1 mm to 30 mm. Method for manufacturing a superabsorbent resin.
In paragraph 1, At least a portion of the above surfactant is present on the surface of the above-mentioned hydrogel polymer, Method for manufacturing a superabsorbent resin.
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In paragraph 1, The above surface crosslinking step (step 4) is, Performed at 80℃ to 120℃, Method for manufacturing a superabsorbent resin.
In paragraph 1, The above surface crosslinking step (step 4) is, Performed for 30 to 120 minutes, Method for manufacturing a superabsorbent resin.
In paragraph 1, The water content of the superabsorbent resin particles is 3.0 wt% to 10.0 wt%, Method for manufacturing a superabsorbent resin.
Manufactured by the manufacturing method of claim 1, Superabsorbent resin.

Description

Preparation Method of Super Absorbent Polymer and Super Absorbent Polymer The present invention relates to a method for manufacturing a superabsorbent resin and a superabsorbent resin. More specifically, the invention relates to a method for manufacturing a superabsorbent resin and a superabsorbent resin capable of suppressing the generation of fine particles during the manufacturing process and simultaneously achieving an excellent absorption rate by controlling the process conditions of the drying step to produce a base resin powder with a relatively high moisture content. Super Absorbent Polymer (SAP) is a synthetic polymer material capable of absorbing 500 to 1,000 times its own weight in moisture, and developers name it by different names such as SAM (Super Absorbency Material) and AGM (Absorbent Gel Material). The above-mentioned super absorbent polymer began to be commercialized for use in physiological devices, and is now widely used as a material for horticultural soil repair agents, waterproofing materials for civil engineering and construction, seedling sheets, freshness preservation agents in the food distribution sector, and compresses. These superabsorbent polymers are widely used in the field of hygiene products, such as diapers and sanitary pads. In the above hygiene products, the superabsorbent polymer is generally contained in a dispersed state within the pulp. However, recently, efforts to provide hygiene products such as thinner diapers have been ongoing, and as part of this, the development of so-called pulpless diapers, in which the pulp content is reduced or no pulp is used at all, is being actively pursued. As such, in the case of sanitary materials in which the pulp content is reduced or no pulp is used, a relatively high proportion of superabsorbent polymer is included, and superabsorbent polymer particles are inevitably included in multiple layers within the sanitary material. In order for the overall superabsorbent polymer particles included in multiple layers to more efficiently absorb a large amount of liquid, such as urine, the superabsorbent polymer basically needs to exhibit not only high absorption performance but also a fast absorption rate. Such superabsorbent resins are generally manufactured through a process involving the polymerization of monomers to produce a hydrogel polymer containing a large amount of moisture, followed by drying the hydrogel polymer and grinding it into resin particles of a desired size. However, when the grinding process is performed after drying the hydrogel polymer as described above, a large amount of fine powder is generated, which causes a problem that degrades the physical properties of the final superabsorbent resin. Meanwhile, improving the moisture content of the superabsorbent polymer reduces fine particles caused by product crushing, lowers product costs, and improves the absorption rate. To obtain the benefits of such high water content, conventional methods involved installing an additional water treatment facility in the surface crosslinking equipment to inject water; however, this approach was economically unfeasible due to the need for additional equipment. Furthermore, using water alone resulted in reduced physical properties due to the formation of sludge, while using additives to prevent sludge formation led to a decrease in the final desired physical properties due to these substances. To address this, there is a need for technology capable of manufacturing products with high moisture content without additional water treatment facilities. The terms used in this specification are used merely to describe exemplary embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, steps, components, or combinations thereof. Terms such as first, second, third, etc. are used to describe various components, and these terms are used solely for the purpose of distinguishing one component from another. The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. (Method for manufacturing superabsorbent resin) A method for manufacturing a superabsorbent resin according to one embodiment of the invention comprises the steps of: forming a water-soluble ethylene-based unsaturated monomer having an acidic group by crosslinking