Polyarylene Sulfide Resin Composition for Insert Molding
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Solution Overview
Problem
Polyarylene sulfide (PAS) resin compositions used in insert molding face challenges with mold deposit formation and limited high- and low-temperature impact properties, which are exacerbated by the thermal deterioration of thermoplastic elastomers and the high flowability required for insert molding.
Innovation Solution
A PAS-derived resin composition incorporating a polyarylene sulfide resin with a carboxylic terminal group and an olefin-derived copolymer containing α-olefin, glycidyl ester of α,β-unsaturated acid, and acrylic ester, with specific molecular weight and copolymerization component ratios, along with an inorganic filler, to enhance high- and low-temperature impact properties while reducing mold deposit formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermoplastic elastomers (olefin-derived copolymers) are incorporated into PAS resin to improve high- and low-temperature impact property, then impact resistance is improved, but mold deposit remarkably increases during molding
Solution Approach 1:
The patent changes the chemical composition parameters of the olefin-derived copolymer by specifying precise copolymerization ratios (52-95 wt% α-olefin, 5-48 wt% α,β-unsaturated carboxylic acid alkyl ester, 0.5-15 wt% epoxy group-containing vinyl monomer) and limiting the glycidyl ester content to 0.08-0.20% by mass. This parameter optimization reduces mold deposit formation while preserving the impact resistance improvement effect.
Solution Approach 2:
The patent creates a composite resin composition combining PAS resin with a specifically formulated olefin-derived copolymer containing multiple copolymerization components (α-olefin, α,β-unsaturated carboxylic acid alkyl ester, and epoxy group-containing vinyl monomer). This composite material achieves both improved impact property and reduced mold deposit compared to using simple elastomers.
2Strength
If resin composition is used for insert molding around engine components, then high- and low-temperature impact property is required, but thermal deterioration of elastomers occurs at elevated temperatures
Solution Approach 1:
The patent optimizes the copolymerization ratio parameters to balance thermal stability and impact property. By controlling the content of each copolymerization component and limiting the glycidyl ester to 0.08-0.20% by mass, the resin composition achieves sufficient impact resistance without excessive elastomer content that would cause thermal deterioration.
Solution Approach 2:
The epoxy group-containing vinyl monomer acts as an intermediary component that enhances the compatibility and thermal stability of the copolymer within the PAS resin matrix, allowing the elastomer to provide impact resistance without undergoing severe thermal deterioration at engine operating temperatures.
3Ease of operation
If PAS resin composition is used for insert molding, then flowability is required, but mold deposit formation occurs during molding
Solution Approach 1:
The patent changes the compositional parameters of the resin system by incorporating an olefin-derived copolymer with specific copolymerization ratios and controlled glycidyl ester content (0.08-0.20% by mass). This composition modification improves flowability for insert molding while minimizing mold deposit formation through optimized chemical structure.
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 significantly reduces mold deposit generation and maintains superior high- and low-temperature impact properties, improving the flowability and moldability of the resin composition for effective insert molding.
Implementation Method 1
a polyarylene sulfide resin having a carboxylic terminal group, and an olefin-derived copolymer which contains an α-olefin, a glycidyl ester of an α,β-unsaturated acid and an acrylic ester as copolymerization components
Data Source
Figure 1
AI summary
Provided is a PAS resin composition with which molded articles having excellent high- and low-temperature impact properties can be obtained and which can be highly inhibited from leaving mold deposits when molded and is suitable for use in insert molding. Also provided is an insert-molded article obtained using the resin composition. The PAS-derived resin composition comprises a PAS resin having carboxylic terminal groups and an olefin-derived copolymer, wherein the olefin-derived copolymer comprises units of an α-olefin, a glycidyl ester of an α,β-unsaturated acid, and an acrylic ester as comonomer units, the PAS resin has a number average molecular weight of 1,000-10,000, and the content of the comonomer units derived from the glycidyl ester in the resin composition is 0.08-0.20 mass%, the ratio of the amount of the carboxylic terminal groups (mmol/kg) and the content of the comonomer units derived from the glycidyl ester (mmol/kg) being 0.35-1.00.