Expandable Thermoplastic Resin Particles for High Heat Resistance

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Solution Overview

Problem

Conventional expandable polystyrene resin particles lack sufficient heat resistance for high-temperature applications due to the presence of styrene in the monomer composition, which limits their use in thermal insulation and automotive components.

Innovation Solution

Developing an expandable thermoplastic resin particle with a monomer composition of 60-80 parts by weight of α-methylstyrene and 20-40 parts by weight of acrylonitrile, ensuring residual monomeric components are less than 0.5% by weight, and optimizing expansion ratios and foam cell structures to enhance heat resistance and mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If styrene is used in the monomer composition for expandable thermoplastic resin particles, then the resin can be easily manufactured and expanded, but the heat resistance is insufficient for high-temperature applications

Engineering Contradiction:
Improveease of manufactureVSAvoidheat resistance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent removes styrene from the monomer composition entirely, extracting the harmful component that limits heat resistance. The composition is replaced with α-methylstyrene and acrylonitrile, which do not contain the styrene structure responsible for poor high-temperature performance, thereby eliminating the heat resistance problem while maintaining manufacturability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters by defining specific weight ratios: 60-80 parts by weight of α-methylstyrene and 20-40 parts by weight of acrylonitrile. This parameter change transforms the material properties to achieve both ease of manufacture and improved heat resistance, resolving the contradiction between these two features

Inventive Principle:
Principle #35Parameter changes

2Temperature

If α-methylstyrene and acrylonitrile are copolymerized to improve heat resistance, then the heat-resistant performance increases, but the residual monomer content increases which deteriorates heat resistance

Engineering Contradiction:
Improveheat resistanceVSAvoidresidual monomer content
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent optimizes the polymerization parameters by controlling the weight ratio of α-methylstyrene (60-80 parts) to acrylonitrile (20-40 parts) and limiting residual monomers to 0.5% by weight or less. This precise parameter control ensures complete reaction of monomers, eliminating residual monomer content that would otherwise deteriorate heat resistance, while maintaining the improved heat-resistant performance from the copolymer composition

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 solution provides improved heat resistance, dimensional stability, and enhanced mechanical strength, making the resin particles suitable for applications in thermal insulation and automotive components, with a dimensional change of less than 0.15% after 24 hours at 90°C and an expansion ratio of 2-15 times.

Implementation Method 1

an expandable thermoplastic resin particle which comprises a polymer obtained from a monomer composition comprising 60 to 80 parts by weight of α-methylstyrene and 40 to 20 parts by weight of acrylonitrile, wherein a content of residual monomeric components in the particle is not more than 0.5% by weight, and the expandable thermoplastic resin particle is expandable at an expansion ratio of 2 to 15 times upon use

Methodology Applied
Scientific EffectFoaming: Foam

Data Source

PatentUS10563056B2Expandable thermoplastic resin particles, thermoplastic pre-expanded particles, and thermoplastic expansion-molded article
Publication Date: 2020.02.18 KANEKA CORP

AI summary

An expandable thermoplastic resin particle including a polymer obtained by a process including polymerizing monomers including 60 to 80 parts by weight of α-methylstyrene and 40 to 20 parts by weight of acrylonitrile. A content of residual monomeric components in the expandable thermoplastic resin particle is not more than 0.5% by weight. When an expanded mold article is produced from the expandable thermoplastic resin particle at an expansion ratio of 10 times, foam cells in a cross section of the expanded mold article have an average chord length of from 20 μm to 60 μm.