ISO 21318-2007 PDF

Full title and description

ISO 21318:2007 — Plastics — Epoxy resins — Determination of electrical conductivity of aqueous resin extracts. This International Standard specifies a laboratory method to obtain an aqueous extract from an epoxy resin by extraction with water at 95 °C and to determine the electrical conductivity of that extract as an indicator of ionic species present in the resin; it is intended for epoxy resins used as insulating materials in electronic devices.

Abstract

ISO 21318:2007 specifies a method for determining the electrical conductivity of an aqueous extract obtained by extraction of an epoxy resin with water at 95 °C. The procedure applies only to epoxy resins that are molten at the extraction temperature. The measured conductivity is used as a measure of the concentration of ionic species that can affect the insulating properties of resins used in electronic equipment.

General information

• Status: Published (confirmed current at last ISO systematic review).
• Publication date: February 2007 (2007-02).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 83.080.10 (Plastics — epoxy resins).
• Edition / version: Edition 1 (2007).
• Number of pages: 3.

Technical committee responsible: ISO/TC 61/SC 12. The ISO record shows the publication was reviewed and confirmed as current in 2020.

Scope

This standard defines a small-scale extraction and measurement method: an epoxy resin sample is extracted with distilled or deionized water at 95 °C to produce an aqueous extract, and the electrical conductivity of that extract is measured to assess the presence and approximate concentration of ionic (conductive) species. The method is explicitly restricted to epoxy resins that are in the molten state at 95 °C and is intended primarily for resins used as electrical insulation in electronic components and assemblies.

Key topics and requirements

• Extraction conditions: water extraction at 95 °C (specified time and sample-to-water ratio are given in the text of the standard).
• Applicability: limited to epoxy resins molten at extraction temperature (not suitable for fully cured or non-molten formulations at 95 °C).
• Measurement: electrical conductivity of the aqueous extract as the principal measured parameter (used as an indicator of ionic contamination or species concentration).
• Interpretation: conductivity used as a comparative QC parameter for resin batches and as an indirect indicator of potential effects on insulation performance in electronic applications.
• Reporting: results expressed as conductivity with clear identification of extraction conditions and instruments used.

For national/adopted equivalents, the ISO method has been adopted identically in some jurisdictions (for example as GB/T 41880-2022 in China which reproduces ISO 21318:2007). Related electrical-resistivity test standards (for different specimen forms or properties) include ASTM D257 and various IEC test methods for volume/surface resistivity.

Typical use and users

Typical users are manufacturers of epoxy resins, quality and R&D laboratories in the plastics and electronics industries, contract test laboratories, and component makers who require verification of ionic contamination levels in resins intended for electrical insulation. The method is used for incoming quality control, batch comparison, material development and in some cases for specification compliance when resin electrical cleanliness is relevant.

Related standards

Standards and documents commonly referenced alongside ISO 21318:2007 include national adoptions/identical translations (for example GB/T 41880-2022 which reproduces ISO 21318), and other electrical-property test standards such as ASTM D257 (DC resistance or conductance of insulating materials) and IEC/ISO documents on surface and volume resistivity. Users often consult the broader suite of plastics testing standards from ISO/TC 61 when establishing comprehensive test programs.

Keywords

ISO 21318, epoxy resin, plastics testing, electrical conductivity, aqueous extract, extraction at 95 °C, ionic species, insulation materials, electrical insulation, resin quality control.

FAQ

Q: What is this standard?

A: ISO 21318:2007 is an ISO test method that specifies how to extract an epoxy resin with water at 95 °C and measure the electrical conductivity of the resulting aqueous extract to assess ionic contamination relevant to electrical insulation performance.

Q: What does it cover?

A: It covers the extraction procedure and conductivity measurement for epoxy resins that are molten at 95 °C; it does not cover cured resins that are not molten at that temperature or other types of plastics. The measured conductivity is an indirect measure of ionic species concentration.

Q: Who typically uses it?

A: Resin manufacturers, electronic-components manufacturers, independent test laboratories and R&D teams use the method for quality control, product development and verification where conductivity of resin extracts is relevant to insulation performance.

Q: Is it current or superseded?

A: As of the ISO record, ISO 21318:2007 (Edition 1) was last reviewed and confirmed in 2020 and remains the current edition. National identical adoptions (e.g., GB/T 41880-2022) exist. Users should check the ISO catalogue or their national body for any later revisions or withdrawals.

Q: Is it part of a series?

A: ISO 21318:2007 is a single-part International Standard focused on one specific test method for epoxy resins; it sits within the broader portfolio of ISO/TC 61 plastics test standards rather than a numbered multi-part ISO 21318 series. The responsible committee is ISO/TC 61/SC 12.

Q: What are the key keywords?

A: Epoxy resin; electrical conductivity; aqueous extract; extraction at 95 °C; ionic species; insulation; plastics testing; ISO 21318.