Water-absorbent resin composition with surface crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sanitary materials like disposable diapers and incontinent pads face issues with gel-blocking due to high water-absorbent resin content, leading to poor liquid diffusion and absorption capacity, and existing solutions fail to maintain performance under physical damage and mechanical stress.
Innovation Solution
A water-absorbent resin composition comprising surface-crosslinked particles polymerized from acrylic acid or its salt, combined with water-soluble polyvalent metal salt particles, where the metal salt is added as dry particles to prevent permeation and enhance liquid permeability and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the ratio of water-absorbent resin is increased to achieve thinning of sanitary materials, then the water absorption quantity is improved, but gel-blocking occurs which deteriorates liquid diffusion ability
Solution Approach 1:
The water-absorbent resin particles are pre-surface-crosslinked before use in the sanitary material. This preliminary crosslinking action modifies the resin structure in advance to prevent gel-blocking during actual use, allowing high water-absorbent resin content without the harmful gelation effect that would normally occur
Solution Approach 2:
The surface crosslinking degree of the water-absorbent resin particles is controlled within a specific range (1-10 mmol/g). By changing this parameter, the resin maintains its water absorption capability while preventing excessive gelation that causes blocking, thus resolving the contradiction between absorption quantity and liquid diffusion
2Length of moving object
If the ratio of hydrophilic fibers is decreased to increase water-absorbent resin content, then thinning is achieved, but liquid diffusion and distribution ability deteriorates
Solution Approach 1:
The water-absorbent resin particles exhibit different properties at different locations: the surface is crosslinked to maintain structural integrity and prevent gel-blocking, while the interior remains uncrosslinked to maintain high water absorption capacity. This local differentiation allows the resin to function effectively with minimal hydrophilic fiber content
3Object-generated harmful factors
If metal compounds are added to prevent gel-blocking and improve liquid permeability, then liquid diffusion is improved, but absorption capacity deteriorates
Solution Approach 1:
The harmful effect of metal compounds on absorption capacity is eliminated by removing them from the system entirely. Instead of adding metal compounds to prevent gel-blocking, the invention uses surface-crosslinked resin particles that inherently prevent gel-blocking without requiring metal additives, thus preserving absorption capacity
4Object-generated harmful factors
If water-absorbent resin is surface-crosslinked to prevent gel-blocking, then liquid diffusion is improved, but particle strength decreases making it vulnerable to physical damage
Solution Approach 1:
Only the surface of the water-absorbent resin particles is crosslinked rather than the entire particle. This partial crosslinking is sufficient to prevent gel-blocking and improve liquid diffusion, while leaving the particle interior uncrosslinked to maintain structural strength and resistance to physical damage
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 solution prevents gel-blocking, maintains high absorption capacity and liquid diffusion, and enhances durability against physical damage, while minimizing segregation and dust generation, ensuring effective moisture handling and retention.
Implementation Method 1
the water-absorbent resin composition having a mass-average particle diameter of 100 to 600 μm and comprising water-soluble polyvalent metal salt particles and the water-absorbent resin particles that have been surface-crosslinked
Implementation Method 2
for the purpose of absorption of body fluids
Implementation Method 3
dramatically deteriorating the ability to diffuse the liquids in the sanitary materials
Implementation Method 4
wherein the metal salt is added as dry particles to prevent permeation and enhance liquid permeability and durability
Data Source
AI summary
There are disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition causes little gel-blocking and is excellent in the liquid permeability and liquid diffusibility and is high also in the absorption performances and further is strong also against the physical damage; and there are further disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition has the following further advantages, in addition to the above, of involving little segregation of the metal compound and further having a dust prevention effect. One of water-absorbent resin compositions according to the present invention is a water-absorbent resin composition comprising water-absorbent resin particles obtained by polymerizing a monomer including acrylic acid and/or its salt, with the composition having a mass-average particle diameter of 100 to 600 μm and comprising water-soluble polyvalent metal salt particles and the water-absorbent resin particles that have been surface-crosslinked.