PPS Resin Composition with Elongational Flow Mixing for Creep Resistance

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Solution Overview

Problem

Polyphenylene sulfide (PPS) resin compositions used in fluid piping face challenges with high-temperature creep characteristics and toughness, particularly at low temperatures, which restrict their application in hot water systems due to deformation and leakage issues.

Innovation Solution

A thermoplastic resin composition is developed by melt-kneading PPS with polyetherimide (PEI) or polyethersulfone (PES) resins using a specific method that includes an elongational flow zone in the extruder, achieving a balance of low-temperature toughness and high-temperature creep resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If PPS resin is mixed with elastomer component to improve low-temperature toughness, then toughness in low temperature range is improved, but heat resistance deteriorates due to low glass transition temperature of elastomer component

Engineering Contradiction:
Improvetoughness in low temperature rangeVSAvoidheat resistance
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The invention changes the type of thermoplastic resin from conventional amorphous resins (PC, ABS, PMMA) to semi-crystalline resins (PA6, PA66, PBT, PET) with specific glass transition temperatures (50-150°C). This parameter change enables the resin to maintain both low-temperature toughness and high-temperature heat resistance, resolving the contradiction between toughness and heat resistance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite resin system by combining PPS resin with specific semi-crystalline thermoplastic resins in controlled ratios (5-50 wt%). This composite approach leverages the complementary properties of both resins to achieve both low-temperature toughness and high-temperature heat resistance simultaneously.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If PPS resin composition is used in hot water piping systems, then it can serve as metal substitute, but molded article undergoes deformation causing water leakage due to poor creep characteristics

Engineering Contradiction:
Improveapplicability as metal substitute in pipingVSAvoidcreep resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention develops a composite resin composition combining PPS with semi-crystalline thermoplastic resins (PA6, PA66, PBT, or PET) in specific proportions. This composite structure provides both the metal-substitute versatility and the creep resistance required for reliable hot water piping applications.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the resin composition parameters by incorporating semi-crystalline resins with specific glass transition temperatures (50-150°C) and controlling their content (5-50 wt%). This parameter optimization simultaneously improves low-temperature toughness and high-temperature creep resistance, enabling reliable piping performance.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional amorphous thermoplastic resins (PC, ABS, PMMA) are mixed with PPS resin, then processability is improved, but low-temperature toughness remains insufficient

Engineering Contradiction:
ImproveprocessabilityVSAvoidlow-temperature toughness
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention changes the key parameter from using amorphous resins with glass transition temperatures below room temperature to using semi-crystalline resins with glass transition temperatures of 50-150°C. This parameter change fundamentally improves low-temperature toughness while maintaining good processability through optimized resin ratios and melt-kneading conditions.

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 resulting resin composition exhibits excellent tensile elongation and creep resistance, suitable for fluid piping applications across a wide temperature range, preventing deformation and leakage in hot water systems.

Implementation Method 1

melt-kneading by an extruder provided with an elongational flow zone which is a zone in which melt-kneading is performed while being allowed to undergo elongational flow

Methodology Applied
Scientific EffectElongational flow:

Implementation Method 2

melt-kneading is performed while being allowed to undergo elongational flow

Methodology Applied
Scientific EffectShear stress: Shear Stress

Data Source

PatentEP2631274B1Method for producing thermoplastic resin composition, thermoplastic resin composition, and molded product
Publication Date: 2018.11.21 TORAY INDUSTRIES INC
  • EP2631274B1 patent drawingFigure 1~2
  • EP2631274B1 patent drawingFigure 3
  • EP2631274B1 patent drawingFigure 4

AI summary

The present invention provides a thermoplastic resin composition, which is excellent in low-temperature toughness and high-temperature creep characteristics, by a method for producing a thermoplastic resin composition by melt-kneading: (a) a polyphenylene sulfide resin, with (b) a polyetherimide resin or a polyethersulfone resin, wherein the thermoplastic resin composition contains 99 to 1% by weight of the component (a) and 1 to 99% by weight of the component (b) based on 100% by weight of the total amount of the component (a) and the component (b); the melt-kneading step is the step of melt-kneading by an extruder provided with an elongational flow zone which is a zone in which melt-kneading is performed while being allowed to undergo elongational flow; and a flow effect pressure drop before and after the elongational flow zone is from 50 to 1,000 kg/cm2.