Expandable Methyl Methacrylate Resin Particles Narrow Particle Size Distribution

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Solution Overview

Problem

Existing expandable methyl methacrylate resin particles have wide particle size distributions, leading to losses during sieving and blocking issues during pre-expansion, resulting in reduced yields and inadequate expandability and formability.

Innovation Solution

Developing expandable methyl methacrylate resin particles with a narrow particle size distribution by copolymerizing methyl methacrylate and acrylic ester monomers, followed by impregnation with a blowing agent, using a poorly water-soluble inorganic salt in the polymerization process to control particle diameter and improve expandability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional expandable methyl methacrylate resin particles are produced, then production can proceed with standard methods, but the particle size distribution becomes wide, causing losses during sieving and blocking during pre-expansion

Engineering Contradiction:
Improveparticle size distributionVSAvoidyield
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the composition ratios of monomers (methyl methacrylate 91-99 parts, acrylic ester 1-9 parts) and adjusting polymerization conditions (temperature 50-90°C, use of poorly water-soluble inorganic salt as dispersion medium) to achieve a narrow particle size distribution with a coefficient of variation of 20% or less, thereby eliminating sieving losses and blocking issues while maintaining high productivity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional expandable methyl methacrylate resin particles are produced, then production can proceed with standard methods, but expandability and formability remain inadequate

Engineering Contradiction:
Improveexpandability and formabilityVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs composite materials by creating a copolymer system combining methyl methacrylate and acrylic ester units in specific ratios, where the acrylic ester component (1-9 parts) provides enhanced expandability and formability while the methyl methacrylate component (91-99 parts) maintains structural integrity, achieving excellent casting performance without overly complicating the manufacturing process

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent uses a poorly water-soluble inorganic salt as an intermediary substance during polymerization to control particle formation and size distribution, which mediates the polymerization process to produce particles with optimal properties for expandability and formability while simplifying the overall manufacturing approach

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach results in expandable methyl methacrylate resin particles with improved yield, expandability, and formability, suitable for use in evaporative pattern casting techniques for metal casting.

Implementation Method 1

the monomers are added to an aqueous medium to initiate a polymerization reaction of the monomers, the aqueous medium containing a poorly water-soluble inorganic salt

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

impregnating a blowing agent in the copolymer thus obtained

Methodology Applied
Scientific EffectGas expansion: Gas Compressor

Data Source

PatentUS12338337B2Expandable methyl methacrylate resin particles, methyl methacrylate resin pre-expanded particles, methyl methacrylate expansion-molded body, and method for producing expandable methyl methacrylate resin particles
Publication Date: 2025.06.24 KANEKA CORP

AI summary

Expandable methyl methacrylate resin particles having a narrow particle size distribution, a good yield, and excellent expandability and formability are provided. The expandable methyl methacrylate resin particles include a base resin containing, as constitutional units, a certain amount of a methyl methacrylate unit and a certain amount of acrylic ester unit, and a blowing agent. The expandable methyl methacrylate resin particles have an average particle diameter of 0.6 mm to 1.0 mm and a particle diameter variation coefficient of not more than 20%.