Superabsorbent Polymer Hydration via Pulse Spray

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Solution Overview

Problem

Existing methods for preparing superabsorbent polymers result in low moisture content, leading to surface property changes and increased fine powder generation, which affects processability and product quality during manufacturing.

Innovation Solution

A method involving thermal or photopolymerization of a monomer composition, followed by drying, grinding, surface cross-linking, and hydration using pulse spraying to control droplet size, optimizing the scattering index of droplets to improve moisture content and reduce fine powder generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If surface cross-linking reaction is conducted by heating at high temperature (140°C or more), then cross-linking reaction efficiency is improved, but moisture content of superabsorbent polymer significantly decreases

Engineering Contradiction:
Improvecross-linking reaction efficiencyVSAvoidmoisture content
Core Design Contradiction:
PowerVSQuantity of substance

Solution Approach 1:

The patent changes the temperature parameter from high temperature (140°C or more) to low temperature (100°C or less) during surface cross-linking reaction. This parameter change allows the cross-linking reaction to proceed efficiently while preserving moisture content, resolving the contradiction between reaction efficiency and moisture retention.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the phase transition properties of water by conducting the cross-linking reaction in an aqueous environment at controlled temperature. The water serves as both solvent and moisture source, allowing the reaction to proceed while maintaining the polymer's moisture content through controlled phase behavior.

Inventive Principle:
Principle #36Phase transitions

2Stability of the object's composition

If moisture content of superabsorbent polymer is low, then storage stability is improved, but surface property changes and fine powder generation increase

Engineering Contradiction:
Improvestorage stabilityVSAvoidsurface property change and fine powder generation
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the moisture content parameter to a specific range (1-10 wt%) after cross-linking. This parameter optimization prevents surface property changes and fine powder generation during storage and handling, while maintaining adequate storage stability. The controlled moisture level acts as a protective factor against surface degradation.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If conventional hydration method using spray nozzle is used, then moisture content is uniformly increased, but device pollution and foreign substance generation occur

Engineering Contradiction:
Improvemoisture content uniformityVSAvoiddevice pollution and foreign substance generation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the spray nozzle component from the hydration system, replacing it with a fluidized bed hydration method. This elimination of the spray nozzle prevents device pollution and foreign substance generation while achieving uniform moisture distribution through fluidization, resolving the contradiction between moisture uniformity and device cleanliness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical spray nozzle system with a fluidized bed system that uses fluid dynamics (air flow) to achieve uniform moisture distribution. This substitution eliminates mechanical contact and potential污染源 from nozzles while maintaining hydration effectiveness through fluid-mechanical interaction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enhances the moisture content of superabsorbent polymers, preventing surface property changes and reducing fine powder generation, thereby improving processability and product quality.

Implementation Method 1

hydrating the surface cross-linked base resin powder by pulse spraying water

Methodology Applied
Scientific EffectHydration: Absorption (physical)

Implementation Method 2

hydrating the surface cross-linked base resin powder by pulse spraying water, wherein a scattering index of droplet generated during the pulse spraying

Methodology Applied
Scientific EffectPulse spraying: Fluid Spray

Implementation Method 3

preparing a hydrogel polymer by carrying out a thermal polymerization or photopolymerization of a monomer composition

Methodology Applied
Scientific EffectThermal polymerization: Exothermic Reaction

Implementation Method 4

preparing a hydrogel polymer by carrying out a thermal polymerization or photopolymerization of a monomer composition

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 5

drying and grinding the hydrogel polymer to prepare a base resin powder

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentUS12157108B2Method for preparing superabsorbent polymer
Publication Date: 2024.12.03 LG CHEM LTD

AI summary

A method for preparing superabsorbent polymer is disclosed herein. In some embodiments, a method includes polymerizing a monomer composition to form a hydrogel polymer, wherein the monomer composition comprises a water soluble ethylenically unsaturated monomer and a polymerization initiator, drying and grinding the hydrogel polymer to prepare a base resin powder, surface cross-linking the base resin powder using a surface cross-linking agent to prepare surface cross-linked base resin powder, and hydrating the surface cross-linked base resin powder by pulse spraying water to prepare a superabsorbent polymer, wherein a scattering index of droplets generated during the pulse spraying is 5 to 10, and wherein the scattering index is calculated in accordance with the following Mathematical Formula 1. The superabsorbent polymer can have an improved moisture content to prevent surface property change of the superabsorbent polymer, and decreased amount of fine powder which improves processability during manufacture of articles using superabsorbent polymer.