【国外标准】 Standard Test Methods for Shellac Used for Electrical Insulation (Withdrawn 2013)

Polymerization time provides a measure of time during which shellac retains its plasticity and flow properties at the specified temperature before gelling or polymerizing to the tough rubbery insoluble form. This test is important in determining the quality of different lots, useful shelf-life, batch uniformity, and processing characteristics of shellac. 1.1 These test methods cover tests for shellac in the dry button or powder form to be used for electrical insulating purposes. Typically, shellac is used as a bonding agent for mica splittings and reconstituted mica paper products, or as a coating or adhesive for other material. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Note 1—There is no similar or equivalent IEC standard. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.