ASTM D6580-00

Standard Test Method for the Determination of Metallic Zinc Content in Both Zinc Dust Pigment and in Cured Films of Zinc-Rich Coatings

SCOPE
1.1 This test method covers the determination of differential scanning calorimetry of the metallic zinc content of both zinc-dust pigment, and of dried films of zinc-rich coatings. This test method is applicable to both inorganic and organic zinc-rich coatings.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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.

General Information

• Status: Historical
• Publication Date: 09-Jul-2000
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.21 - Chemical Analysis of Paints and Paint Materials

Relations

• Replaced By: ASTM D6580-00(2005) - Standard Test Method for the Determination of Metallic Zinc Content in Both Zinc Dust Pigment and in Cured Films of Zinc-Rich Coatings
• Effective Date: 01-Jul-2005
• Referred By: ASTM D521-02(2019) - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 10-Jul-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D6580–00
Standard Test Method for
The Determination of Metallic Zinc Content in Both Zinc
Dust Pigment and in Cured Films of Zinc-Rich Coatings
This standard is issued under the fixed designation D 6580; 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 4. Significance and Use
1.1 Thistestmethodcoversthedeterminationbydifferential 4.1 This test method is useful for determining the amount of
scanning calorimetry of the metallic zinc content of both metallic zinc in zinc dust pigment, and also in dried films of
zinc-dust pigment, and of dried films of zinc-rich coatings. both inorganic and organic zinc-rich coatings. Test Methods
This test method is applicable to both inorganic and organic D 521 is an appropriate method for analyzing zinc dust, but has
zinc-rich coatings shortcomings when applied to samples of cured coatings.
1.2 The values stated in SI units are to be regarded as the
5. Interferences
standard. The values given in parentheses are for information
5.1 An increase or decrease in heating rate from those
only.
1.3 This standard does not purport to address all of the specified may slightly alter the results. However, the variation
would be expected to be minimal, so long as the zinc reference
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- standard and the samples are subjected to the same heating
rate.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 5.2 Dailycalibrationofthecalorimeterwithhighpurityzinc
foil results in improved results. Reagent grade zinc granules or
2. Referenced Documents
zinc powder are of insufficient purity to properly calibrate the
2.1 ASTM Standards: instrument. Furthermore, the high purity zinc foil should only
D 521 Test Methods for Chemical Analysis of Zinc-Dust beusedonetimeasacalibrationstandard.Warning:Usingthe
(Metallic Zinc Powder) same piece of foil more than once can result in inaccurate
E 691 Practice for Conducting an Interlaboratory Study to results, due to oxidation of the zinc at the high temperatures in
Determine the Precision of a Test Method the calorimeter, coupled with the alloying effects of zinc with
the aluminum sample pans.
3. Summary of Test Method
5.3 Important steps in achieving accurate and reproducible
3.1 Samples of either zinc-dust pigment or of cured films of results are very gentle tapping of the pan in order to distribute
zinc-rich coatings are ground in a mortar and pestle, then
the sample evenly over the bottom of the pan, and careful
carefully weighed into standard differential scanning calorim- placement of the pan lid to avoid expulsion of the fine powder
etry (DSC) sample pans. The pans are then crimped shut, and
during crimping.
analyzed in a differential scanning calorimeter in a single
NOTE 1—Round-robin testing has shown no evidence that pyrolysis of
dynamic heating step, ranging from 370 to 435°C at 10°C per
the binder interferes with the measurement of the heat of fusion. Either
min, under a nitrogen purge. The percent metallic zinc in the
pyrolysis does not occur, occurs during stabilization of the instrument
sample is determined by measuring the energy associated with
prior to the scan, or is negligible due to the small amount of binder present
in such coatings. If there is reason to suspect interference from the binder,
the endothermic peak near 419°C caused by the melting of the
the analyst may wish to test a blank sample of binder (with no zinc
metallic zinc, and comparing this value to the heat of fusion of
pigment) to ensure that there is no effect on heat flow measurements.
pure zinc.
6. Apparatus
6.1 Differential Scanning Calorimeter, either of the heat
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications, and is the direct responsibility of
fluxorpowercompensationtype,capableofheatingratesupto
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
at least 10 6 1°C/min and of automatic recording of difference
Current edition approved July 10, 2000. Published September 2000.
2 in heat input between the sample and a reference material, to
Annual Book of ASTM Standards, Vol 06.03.
Annual Book of ASTM Standards, Vol 14.02. the required sensitivity and precision.
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D6580
6.2 Sample Pans—Aluminum or other metal pans of high 9. Calculation
thermal conductivity are appropriate. A method or instrument
9.1 Calculate the percent metallic zinc in the sample as
for crimping the pans shut is also necessary.
follows:
6.3 Reference Material—High purity zinc foil suitable for
Percent zinc metal5~X/108! · 100, (1)
calibration of DSC instruments can be obtained from several
instrument manufacturers.
where:
6.4 Nitrogen, or other inert gas supply, f
...