ASTM D1304-99

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Designation:D1304–99
Standard Test Methods for
Adhesives Relative to Their Use as Electrical Insulation
This standard is issued under the fixed designation D 1304; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Arc Resistance of Solid Electrical Insulation
D 897 Test Method for Tensile Properties of Adhesive
1.1 These test methods cover procedures for testing adhe-
Bonds
sives in liquid, highly viscous, solid, or set states, that are
D 907 Terminology of Adhesives
intended to be cured by electronic heating, or that are intended
to provide electrical insulation, or that are intended for use in
3. Terminology
electrical apparatus.
3.1 Definitions—Many terms in these test methods are
1.2 The procedures appear in the following order:
defined in Terminology D 907.
(1) Procedure for Testing Adhesives Before Use:
Section
4. Significance and Use
Power Factor and Dielectric Constant of Liquid Adhesives 7
Direct-Current Conductivity 8
4.1 Insulatingmaterialsareusedtoisolatecomponentsofan
Extract Conductivity 9
electrical system from each other and from ground, as well as
Acidity and Alkalinity 10
to provide mechanical support for the components. For this
pH Value 11
purpose, it is generally desirable to have the insulation resis-
(2) Procedures for Testing Properties of Adhesives As Used:
tance as high as possible, consistent with acceptable mechani-
Section
cal, chemical, and heat-resisting properties. Since insulation
Power Factor and Dielectric Constant of a Dried or Cured Adhesive
resistance or conductance combines both volume and surface
Film 12
Dielectric Strength 13
resistance or conductance, its measured value is most useful
Volume and Surface Resistivity 14
when the test specimen and electrodes have the same form as
Arc Resistance 15
is required in actual use. Surface resistance or conductance
1.3 This standard does not purport to address all of the
changes rapidly with humidity, while volume resistance or
safety concerns, if any, associated with its use. It is the
conductance changes slowly although the final change may
responsibility of the user of this standard to establish appro-
eventually be greater.
priate safety and health practices and determine the applica-
4.2 Resistivity or conductivity is used to predict, indirectly,
bility of regulatory limitations prior to use. For a specific
the low-frequency dielectric breakdown and dissipation factor
hazard statement, see 8.2.
properties of some materials. Resistivity or conductivity is
often used as an indirect measure of moisture content, degree
2. Referenced Documents
of cure, mechanical continuity, and deterioration of various
2.1 ASTM Standards:
types. The usefulness of these indirect measurements is depen-
D 115 Test Methods for Testing Solvent Containing Var-
dent on the degree of correlation established by supporting
nishes Used for Electrical Insulation
theoretical or experimental investigations. A decrease of sur-
D 150 Test Methods for AC Loss Characteristics and Per-
face resistance will result either in an increase of the dielectric
mittivity (Dielectric Constant) of Solid Electrical Insula-
breakdown voltage because the electric field intensity is
tion
reduced, or a decrease of the dielectric breakdown voltage
D 202 Test Methods for Sampling and Testing Untreated
because the area under stress is increased.
Paper Used for Electrical Insulation
4.3 All the dielectric resistances or conductances depend on
D 257 Test Methods for DC Resistance or Conductance of
the length of time of electrification and on the value of applied
Insulating Materials
voltage (in addition to the usual environmental variables).
D 495 Test Method for High-Voltage, Low-Current, Dry
Thesemustbeknowntomakethemeasuredvalueofresistance
or conductance meaningful.
4.4 Volume resistivity or conductivity is used as an aid in
These test methods are under the jurisdiction of ASTM Committee D-14 and
designing an insulator for a specific application. The change of
are the direct responsibility of Subcommittee D14.80 on Metal Bonding Adhesives
Current edition approved May 10, 1999. Published August 1999. Originally
published as D 1304 – 54. Last previous edition D 1304 – 93.
2 3
Annual Book of ASTM Standards, Vol 10.01. Annual Book of ASTM Standards, Vol 15.06.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1304
resistivity or conductivity with temperature and humidity may 8.2 Pour approximately 10 g of the sample into a low-form
be great, and must be known when designing for operating weighing bottle, cover, and weigh. After removing the cover
conditions. Volume resistivity or conductivity determinations
apply heat at 70°C until the sample reaches constant weight
are often used in checking the uniformity of an insulating
(see Note 1). Then cool the sample in a desiccator and weigh.
material, either with regard to processing or to detect conduc-
NOTE 1—Caution—Care should be exercised when volatile materials
tive impurities that affect the quality of the material and that
are of such a nature as to constitute toxic, fire, or explosive hazard.
may not be readily detectable by other methods.
21 19
4.5 Volume resistivities above 10 V·cm (10 V·m), ob-
8.3 Calculations— Calculate the percentage of total solids
tained on specimens under usual laboratory conditions, are of
as follows:
doubtful validity, considering the limitations of commonly
Total solids, percent 5 wt of residue/wt of sample 3 100 (1)
used measuring equipment.
4.6 Surface resistance or conductance cannot be measured 8.4 Stirthedriedadhesiveintothesolventwithacleanglass
accurately,onlyapproximated,becausesomedegreeofvolume
rod until all the adhesive is dissolved. Return the cell to the
resistance or conductance is always involved in the measure-
solution and raise and lower it in the solution several times.
ment. The measured value is also affected by the surface
Determine volume resistivity of the solution r and calculate
contamination. Surface contamination, and its rate of accumu-
conductivity, s, as follows:
lation, is affected by many factors including electrostatic
s~ micromho cm! 5 1/r 2 1/r
0 1
charging and interfacial tension. These, in turn, may affect the
(2)
surface resistivity. Surface resistivity or conductivity can be
considered to be related to material properties when contami-
9. Extract Conductivity
nation is involved but is not a material property in the usual
sense.
9.1 Procedure—Determine the extract conductivity of an
adhesive and report in accordance with the procedure specified
5. General Considerations
for Aqueous Extract Conductivity in Test Methods D 202,
5.1 Definitions, theory, and measuring equipment pertaining except use a 5-g sample of adhesive in a solid state, or
to this method shall be in accordance with test methods already sufficient sample to be equivalent to5gof solids based on
established for the property under consideration.
determining percentage total solids in accordance with 4.2. For
adhesivessolubleinasolvent(notwater)addasuitablereagent
6. Test Specimens
grade solvent as selected or agreed upon by the manufacturer
6.1 For tests that are to be performed upon the adhesive and user, or as specified in the specification or purchase order,
itself, the specimens shall consist of an adequate representative
until the total volume is 100 ml. Stir and warm gently until the
sample which, until required, shall be kept at room temperature
sample is completely dissolved or diluted. To the solution add
in a nearly filled, tightly sealed container to avoid contamina-
slowly with constant stirring 100 ml of boiling distilled water.
tion or escape of solvents.
Gentlywarmwithconstantstirringonanelectrichotplateuntil
6.2 For
...