ISO 11248:1993 プラスチック—熱硬化性成形材料—高温での短期性能の評価 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

International Standard ISO 11248 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 12, Thermosetting materials.

Introduction

Plastic materials, when exposed to heat, may undergo physical and/or chemical changes. The extent of such changes is dependent upon temperature and exposure time. These changes may or may not be evident when the plastic materials are returned to ambient temperature.

In ISO 2578:1993, Plastics — Determination of time-temperature limits after prolonged exposure to heat and similar standards, testing is carried out at ambient temperature. In such standards it is primarily the permanent effects of thermal oxidation on plastics exposed to elevated temperatures for extended periods of time which are addressed. Undefined, however, are any high-temperature physical and or chemical changes that occur while the materials are exposed to the elevated temperatures. This International Standard is designed to provide data indicating how plastic materials may perform at elevated temperatures under mechanical and/or electrical stress.

1 Scope

This International Standard specifies a method for the determination of the mechanical, electrical, thermal and other properties of thermosetting moulding materials when tested under defined conditions at elevated temperatures.

The method is used for the determination of the relative performance temperature (RPT) of thermosetting moulding materials. This RPT is necessary in describing the short-term performance of these materials at elevated temperatures. Coupled with the long-term property evaluations of polymeric materials, the RPT provides designers and engineers with a more complete picture of the expected performance of materials in use at elevated temperatures.

2 Normative references

The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.