Coated Water-Absorbent Resin Particles to Prevent Gel Blocking

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Solution Overview

Problem

Conventional water-absorbent resin particles reach a swelling state quickly after contact with liquid, leading to gel blocking phenomena that hinder liquid diffusion and cause leakage, and adjusting polymerization conditions to control the water absorption rate is complex.

Innovation Solution

A coated resin particle with a water-soluble coating layer having a solubility of 1.0 g to 150 g in 100 g of water at 25°C is applied to the surface of water-absorbent resin particles, slowing down the water absorption rate without altering the polymerization conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If water-absorbent resin particles are used to achieve high water absorption capacity, then water absorption capacity is improved, but water absorption rate becomes too fast causing gel blocking phenomenon

Engineering Contradiction:

Improvewater absorption capacityVSAvoidwater absorption rate

Core Design Contradiction:

Quantity of substanceVSSpeed

Solution Approach 1:

A coating layer comprising a water-soluble polymer is applied to the surface of the water-absorbent resin particles. This coating layer acts as an intermediary that temporarily controls the water absorption rate by dissolving gradually in water, allowing the underlying high-capacity resin to absorb water at a controlled pace without experiencing gel blocking phenomenon.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If polymerization conditions are changed to control water absorption rate, then water absorption rate is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvewater absorption rateVSAvoidpolymerization conditions complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

Instead of changing polymerization conditions, the invention changes the parameters of the coating layer by selecting water-soluble polymers with specific solubility characteristics. The solubility and molecular weight of the coating polymer are adjusted to control the water absorption rate, providing a simpler alternative to modifying polymerization processes.

Inventive Principle:

Principle #35Parameter changes

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 coated resin particle effectively prevents gel blocking by controlling the absorption rate, allowing for a gradual water absorption that reduces leakage and maintains capacity over time.

Implementation Method 1

the coating layer contains a water-soluble component in which a solubility in 100 g of water is in a range of 1.0 g or more and 150 g or less at 25° C.

Methodology Applied

Scientific EffectSolubility: Solvation

Implementation Method 2

water-absorbent resin particles reach a swelling state (a state in which water cannot be absorbed any more) in a relatively short time after coming into contact with a liquid to be absorbed

Methodology Applied

Scientific EffectWater absorption: Absorption (physical)

Data Source

PatentUS12590190B2Coated resin particles and method for producing coated resin particles

Publication Date: 2026.03.31 SUMITOMO SEIKA CHEM CO LTD

AI summary

One aspect of the present invention relates to a coated resin particle including: a water-absorbent resin particle; and a coating layer that coats at least a part of a surface of the water-absorbent resin particle, in which the coating layer contains a water-soluble component in which a solubility in 100 g of water is in a range of 1.0 g or more and 150 g or less at 25° C.