ASTM D6580-17(2023)

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

SIGNIFICANCE AND USE
4.1 This test method is useful for determining the amount of metallic zinc in zinc dust pigment, and also in dried films of both inorganic and organic zinc-rich coatings. Test Methods D521 is an appropriate method for analyzing zinc dust, but has shortcomings when applied to samples of cured coatings.
SCOPE
1.1 This test method covers the determination by 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2023
• 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

• Refers: ASTM D521-02(2019) - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 01-Jun-2019
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM D521-02(2012) - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 01-Nov-2012
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM D521-02(2007) - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 01-Jun-2007
• Refers: ASTM E691-05 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2005
• Refers: ASTM D521-90(1999) - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 10-Jan-2002
• Refers: ASTM D521-02 - Standard Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder)
• Effective Date: 10-Jan-2002
• Refers: ASTM E691-99 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 10-May-1999

Overview

ASTM D6580-17(2023), Standard Test Method for the Determination of Metallic Zinc Content in Both Zinc Dust Pigment and in Cured Films of Zinc-Rich Coatings, is a key standard developed by ASTM International for the accurate measurement of metallic zinc content. This method employs differential scanning calorimetry (DSC) to assess metallic zinc in both zinc-dust pigment and in dried films of zinc-rich coatings, including both inorganic and organic formulations. The standard plays a crucial role in quality control for materials used in protective coatings, ensuring product performance and regulatory compliance.

Key Topics

• Scope and Applicability

  • Determines metallic zinc content via DSC in zinc-dust pigments and cured zinc-rich coatings.
  • Suitable for both inorganic and organic coating films.
  • Expresses results in SI units, with parenthetical values for information.

• Significance

  • Essential for manufacturers and applicators of zinc-rich coatings to verify zinc content and performance.
  • Addresses limitations of other chemical analysis methods (e.g., ASTM D521), especially with cured coatings.
  • Supports adherence to international standardization principles as outlined by the World Trade Organization (WTO) Technical Barriers to Trade (TBT) Committee.

• Method Overview

  • Requires sample preparation including grinding and weighing.
  • Uses differential scanning calorimeter to identify the endothermic peak corresponding to the melting of metallic zinc (near 419°C).
  • Metallic zinc content is calculated based on measured heat of fusion compared to a high-purity zinc reference.

• Precision and Reproducibility

  • Repeatability for a single analyst shows approximately 2.8% relative standard deviation.
  • Multilaboratory reproducibility is approximately 5.0% coefficient of variation.
  • Emphasizes daily calibration and standardized procedures to ensure accuracy.

Applications

• Quality Control in Coatings Manufacturing

  • Verifying metallic zinc content in raw zinc-dust pigment and final coating films ensures corrosion protection goals are met, particularly for steel structures and industrial equipment.
  • Applicable in inspection and validation of zinc-rich primers and protective coatings for infrastructure, marine, and construction industries.

• Research and Development

  • Facilitates comparative studies and benchmarking between different zinc-rich coating formulations and pigment sources.

• Regulatory and Compliance

  • Supports manufacturers in meeting performance specifications and regulatory requirements for zinc-based corrosion protection systems.
  • Provides standardized reporting practices essential for product certification and marketplace acceptance.

• Laboratory Analysis

  • Used by laboratories for routine testing, interlaboratory studies, and method validation involving zinc content determination.

Related Standards

• ASTM D521 - Test Methods for Chemical Analysis of Zinc Dust (Metallic Zinc Powder). While suitable for zinc dust, this method may not account for properties of cured films.
• ASTM E691 - Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method. Referenced for statistical analysis and precision criteria in ASTM D6580.
• Other Zinc-rich Coating Standards - ASTM and ISO publish additional standards relevant to the application, performance, and testing of zinc-rich coatings.

By following ASTM D6580-17(2023), stakeholders can ensure accurate, repeatable determination of metallic zinc in both pigment and cured coatings, supporting material quality, longevity, and regulatory compliance in protective coatings industries.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6580 − 17 (Reapproved 2023)
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 D6580; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope etry (DSC) sample pans. The pans are then crimped shut, and
analyzed in a differential scanning calorimeter in a single
1.1 This test method covers the determination by differential
dynamic heating step, ranging from 370 °C to 435 °C at 10 °C
scanning calorimetry of the metallic zinc content of both
per min, under a nitrogen purge. The percent metallic zinc in
zinc-dust pigment, and of dried films of zinc-rich coatings.
the sample is determined by measuring the energy associated
This test method is applicable to both inorganic and organic
with the endothermic peak near 419 °C caused by the melting
zinc-rich coatings.
of the metallic zinc, and comparing this value to the heat of
1.2 The values stated in SI units are to be regarded as the
fusion of pure zinc.
standard. The values given in parentheses are for information
only.
4. Significance and Use
1.3 This standard does not purport to address all of the
4.1 This test method is useful for determining the amount of
safety concerns, if any, associated with its use. It is the
metallic zinc in zinc dust pigment, and also in dried films of
responsibility of the user of this standard to establish appro-
both inorganic and organic zinc-rich coatings. Test Methods
priate safety, health, and environmental practices and deter-
D521 is an appropriate method for analyzing zinc dust, but has
mine the applicability of regulatory limitations prior to use.
shortcomings when applied to samples of cured coatings.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Interferences
ization established in the Decision on Principles for the
5.1 An increase or decrease in heating rate from those
Development of International Standards, Guides and Recom-
specified may slightly alter the results. However, the variation
mendations issued by the World Trade Organization Technical
would be expected to be minimal, so long as the zinc reference
Barriers to Trade (TBT) Committee.
standard and the samples are subjected to the same heating
rate.
2. Referenced Documents
5.2 Daily calibration of the calorimeter with high purity zinc
2.1 ASTM Standards:
D521 Test Methods for Chemical Analysis of Zinc Dust foil results in improved results. Reagent grade zinc granules or
zinc powder are of insufficient purity to properly calibrate the
(Metallic Zinc Powder)
E691 Practice for Conducting an Interlaboratory Study to instrument. Furthermore, the high purity-zinc foil should only
be used one time as a calibration standard. Warning—Using
Determine the Precision of a Test Method
the same piece of foil more than once can result in inaccurate
3. Summary of Test Method
results, due to oxidation of the zinc at the high temperatures in
the calorimeter, coupled with the alloying effects of zinc with
3.1 Samples of either zinc-dust pigment or of cured films of
the aluminum sample pans.
zinc-rich coatings are ground in a mortar and pestle, then
carefully weighed into standard differential scanning calorim-
5.3 Important steps in achieving accurate and reproducible
results are very gentle tapping of the pan in order to distribute
the sample evenly over the bottom of the pan, and careful
This test method is under the jurisdiction of ASTM Committee D01 on Paint
placement of the pan lid to avoid expulsion of the fine powder
and Related Coatings, Materials, and Applications and is the direct responsibility of
during crimping.
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
Current edition approved July 1, 2023. Published August 2023. Originally
NOTE 1—Round-robin testing has shown no evidence that pyrolysis of
approved in 2000. Last previous edition approved in 2017 as D6580 – 17. DOI:
the binder interferes with the measurement of the heat of fusion. Either
10.1520/D6580-17R23.
pyrolysis does not occur, occurs during stabilization of the instrument
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
prior to the scan, or is negligible due to the small amount of binder present
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on in such coatings. If there is reason to suspect interference from the binder,
the ASTM website. the analyst may wish to test a blank sample of binder (with no zinc
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6580 − 17 (2023)
pigment) to ensure that there is no effect on heat flow measurements.
nitrogen purge. The area under the endothermic transition
corresponding to the melting (fusion) of zinc, in joules per
6. Apparatus
gram, should then be determined in the same fashion as
6.1 Differential Scanning Calorimeter, either of the heat flux
described for the zinc foil reference standard. Triplicate analy-
or power compensation type, capable of heating rates up to at
ses should be performed, and the results should be averaged to
least 10 °C ⁄min 6 1 °C ⁄min and of automatic recording
...