ASTM D5380-93(2021)

Standard Test Method for Identification of Crystalline Pigments and Extenders in Paint by X-Ray Diffraction Analysis

SIGNIFICANCE AND USE
4.1 The choice of pigments and extenders influences the appearance, durability, cost, and other properties of paint. This test method is a convenient way, and probably the most reliable, to identify pigments in paint.
SCOPE
1.1 This test method covers the identification of crystalline pigments and extenders in liquid paint and dry paint film. It is applicable to both water-reducible and solvent-reducible paint. It also may be used to identify pigment and extender in grind paste or alone as dry powder. It is not applicable to amorphous components such as carbon black, amorphous silica, or highly processed clay.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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. Specific hazard statements are given in Section 6.  
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: 31-Jan-2021
• 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 D3925-02(2010) - Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
• Effective Date: 01-Dec-2010
• Refers: ASTM D3925-02 - Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
• Effective Date: 10-Aug-2002
• Refers: ASTM D3925-91(1996) - Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
• Effective Date: 15-Sep-1991

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: D5380 −93 (Reapproved 2021)
Standard Test Method for
Identification of Crystalline Pigments and Extenders in Paint
by X-Ray Diffraction Analysis
This standard is issued under the fixed designation D5380; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Whether the substance is present alone or in a mixture, it
produces its pattern independently and can be identified by it.
1.1 This test method covers the identification of crystalline
An X-ray diffraction pattern of a sample is recorded. Each
pigments and extenders in liquid paint and dry paint film. It is
crystalline substance in the sample is identified by the
applicable to both water-reducible and solvent-reducible paint.
Hanawalt or Fink method or other systematic procedure based
It also may be used to identify pigment and extender in grind
on comparison of the diffraction pattern of the sample with
paste or alone as dry powder. It is not applicable to amorphous
3,4,5
reference patterns of standards.
components such as carbon black, amorphous silica, or highly
processed clay.
4. Significance and Use
1.2 The values stated in SI units are to be regarded as
4.1 The choice of pigments and extenders influences the
standard. No other units of measurement are included in this
appearance, durability, cost, and other properties of paint.This
standard.
test method is a convenient way, and probably the most
1.3 This standard does not purport to address all of the
reliable, to identify pigments in paint.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 5. Apparatus
priate safety, health, and environmental practices and deter-
5.1 X-ray Diffractometer, suitable for collecting intensity
mine the applicability of regulatory limitations prior to use.
versus two theta (20) angle diffraction patterns in the range
Specific hazard statements are given in Section 6.
from 5° to 65° 20. It is preferred that the diffractometer be
1.4 This international standard was developed in accor-
equippedwithacoppertargetX-raytubeandamonochromator
dance with internationally recognized principles on standard-
that passes only copper K-alpha radiation. If a monochromator
ization established in the Decision on Principles for the
is not available, then a suitable filter may be used to remove
Development of International Standards, Guides and Recom-
copper K-beta radiation from the diffracted X-ray beam. A
mendations issued by the World Trade Organization Technical
nickel filter may be used for this purpose when a copper target
Barriers to Trade (TBT) Committee.
tube is employed.
2. Referenced Documents NOTE 1—Follow the recommendations of the manufacturer of the
diffractometer used.
2.1 ASTM Standards:
5.2 Liquid Paint or Grind Paste:
D3925Practice for Sampling Liquid Paints and Related
5.2.1 Paint Shaker.
Pigmented Coatings
5.2.2 Film Applicator, that will produce a 3- to 10-mil (75-
to 250 µm) wet film thickness.
3. Summary of Test Method
5.2.3 Plastic Sheet, such as polyester film, that contains no
3.1 Every crystalline substance, in this case pigment or
crystalline components that would produce interfering X-ray
extender, has a characteristic X-ray diffraction pattern.
diffraction peaks and is not attacked by paint solvent.
5.2.4 Perforated Suction Plate or other flat surface.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
5.3 Paint Chips or Pigment Powder:
and Related Coatings, Materials, andApplications and is the direct responsibility of
5.3.1 Miniature Reciprocating Ball Mill.
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
Current edition approved Feb. 1, 2021. Published February 2021. Originally
approved in 1993. Last previous edition approved in 2014 as D5380–93(2014).
DOI: 10.1520/D5380-93R21. Search Manual, (Hanawalt), “Inorganic Phases,” International Centre for
For referenced ASTM standards, visit the ASTM website, www.astm.org, or DiffractionData,(ICDD),CatalogNo.HA42,NewtownSquareCorporateCampus,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 12 Campus Blvd., Newtown Square, PA19073-3273.
Standards volume information, refer to the standard’s Document Summary page on Search Manual, (Fink), “Inorganic Phases,” ICDD.
the ASTM website. “Powder Diffraction File, Inorganic,” ICDD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5380 − 93 (2021)
5.3.2 Stainless Steel Vials, with agitator for ball mill. to the same dimensions as the specimen holder and use the
5.3.3 Powder Specimen Holders, for X-ray diffractometer. specimen without the holder.
NOTE 3—An X-ray diffraction pattern collected for coating on a panel
6. Hazards
will be a superposition of the diffraction patterns of the crystalline
6.1 Precaution—As exposure to excessive quantities of components in the coating on the panel and, to the extent that X-rays
diffracted from the substrate reach the detector, the diffraction pattern of
X-radiation is injurious to health, X-ray producing equipment
the substrate.
can be dangerous to both the operator and persons in the
7.2 Mount the specimen in the specimen holder, taking care
immediate vicinity unless safety precautions are strictly ob-
to insure that the surface of the specimen is flush with the
served. Therefore, users should avoid exposing any parts of
optical plane of the holder.
their bodies, not only to the direct beam, but also to secondary
or scattered radiation that occurs when an X-ray beam strikes
NOTE 4—Failure to place the specimen surface in the optical plane
orpassesthroughanymaterial.Itisstronglyrecommendedthat
illuminated by the X-ray source and viewed by the detector will result in
users check the degree of exposure by film carried on them or a systematic shift from the correct position of peaks in the observed
diffractogram. The greater the shift, the greater the difficulty in using the
by the use of dosimeters and that blood counts be made
observed diffractogram to identify components in the specimen.
periodically. Before utilizing the equipment, all persons desig-
nated or authorized to operate X-ray instrumentation or super-
8. Procedure
viseitsoperation,shouldhaveafullunderstandingofitsnature
8.1 Experimental:
andshouldalsobecomefamiliarwithestablishedsafeexposure
8.1.1 Turn on the diffractometer and allow it to stabilize
factors by a careful study of the NIST handbook, “X-ray
thoroughly before beginning collection of results. With the aid
RecommendationsoftheInternationalRoentgenRayCommit-
of the manufacturer’s literature, select instrument operation
tee on X-ray Protection,” the manufacturer’s instruction
conditions that permit collection of X-ray diffractograms
manual, and other standard publications on the subject. Inqui-
spanning the two-theta range from 5 to 65°. The conditions
ries should be made of state agencies as to existing require-
chosen must be suitable for qualitative analysis of a multicom-
ments.
ponent mixture assuming the presence of a minor component
present at approximately one percent by weight. Results
7. Specimen Preparation
collected must be available as the d-spacing and intensity,
7.1 Prepare a specimen from the sample using one of the
preferably the integrated intensity, of each peak. In the case of
following methods:
diffractometers not equipped with a computer, the two-theta
7.1.1 Liquid Paint or Pigment Paste—Thoroughly mix and
and intensity data must be measured manually from plotted
sample the paint or paste in accordance with Practice D3925.
diffractionpatternsandthe d-spacingsthencalculatedfromthe
Place a plastic sheet on the perforated suction plate. On the
two-theta angles of the peaks. In the latter case, the diffraction
sheet make a drawdown of the sample.Awet film thickness of
patterns must be plotted with two-theta scale expansion that
3.0 to 10.0 mil (75 to 250 µm) is suggested. Cut from the
permits the angle of each peak to be measured to the nearest
drawdown on the plastic sheet a specimen of shape and size
0.01 Å for peaks in the range above 3.5 Å and to the nearest
suitable for the mounting in the specimen holder of the
0.001 Å for peaks below approximately 3.5 Å.
diffractometer.
NOTE 5—If not already established, then make sure that the two-theta
7.1.2 Paint Chip—Using a ball mill, grind to a powder the
calibration of the goniometer of the diffractometer is verified at two or
paint chip or, if it contains more than one layer, the part of the
moreanglesinaccordancewithrecommendationsofthemanufacturerand
chipofinterest.Preparesufficientspecimentofillthespecimen
correctedasneeded.Theprocedurewillentailcomparisonoftheobserved
holder or to satisfy the requirements of the preparation tech-
andexpected d-spacingofdiffractionpeaksofhighlycrystallinereference
nique to be used. In cases where the chip has a planar surface materials at least at one high and one low two-theta angle.
anduniformthickness,itmaybepossibletocutthechiptothe
8.1.2 For each sample correct the diffraction pattern span-
required dimensions and mount it directly in the specimen
ning at least from 5 to 65° two-theta.
holder with no preparation.
9. Identification
NOTE 2—X-ray diffraction patterns collected for specimens consisting
ofwholechipswillrevealthecompositionofallpaintlayersprobedbythe 9.1 Prepare a list of all diffraction peaks exhibited by the
X-rays.ThedepthprobedwilldependuponthewavelengthofX-rayused,
sample including both the d-spacing and intensity (preferably
thecompositionofthepaintlayerorlayersthroughwhichtheX-rayspass,
integrated intensity) of each peak, listed in decreasing order of
thecompositionofthedeepestlayerprobed,thetwo-thetaangle,andother
d-spacing. The d-spacing of each peak should be stated at the
factors. When a copper X-ray tube is used, the depth probed may range
nearest hundredth of an angstrom for d-spacings greater than
from as little as approximately 2 mils (75 µm) in the case of very high
density coatings to as much as 197 mils (0.5 cm) in the case of
3.5 Å and stated to the nearest thousandth of an angstrom for
unpigmented resin.
d-values of less than about 3.5 Å.
7.1.3 Paint Film on Panel—Cut from the panel a specimen
9.2 Identify the crystalline phase or phases that account for
ofdimensionssuitableformountinginthespecimenholder.As
allpeaksinthediffractionpatternofthesampleunderanalysis,
an alternative, it may be convenient to cut a piece of specimen
using the Hanawalt Method, Fink Method, or other systematic
procedure. Full identification of the crystalline components
may be speeded by use of information about components
NIST Handbook, X-Ray Recommendations for the International Roentgen Ray
Committee on X-Ray Protection, NIST, Gaithersburg, MD, 20899. known to be or suspected of being in the sample (that is,
D5380 − 93 (2021)
preconceived composition) or by use of the list of common peaks.) If all three peaks are present, then make sure that the
pigments and extenders appended (see Table 1). file number beside the listed d-values is noted and the full set
9.2.1 Verification of Preconceived Components:
of diffraction data for the suspected component is inspected in
9.2.1.1 Prepare a list of components known to be present or the Powder Data File.
suspected of being present on the basis of other information, if
9.2.1.2 Confirmation of the presence of the suspected com-
any,availabletotheuser.UsetheICDDAlphabeticalIndex or
ponent requires that all peaks listed for the suspect in the
other compilation of diffraction peak data to determine the
Powder Diffraction File, or other reference source, must be
d-valuesofthethreestrongestpeaksofasuspectedcomponent.
present in the diffraction pattern of the sample. Furthermore,
Compare the three peaks for the suspected component listed in
therelativeintensityofthepeaksinthediffractionpatternmust
the Alphabetical Index with the set of diffraction peaks
be similar to the relative intensity of the peaks in the reference
observed for the sample under analysis. If any one of the three
pattern when experimental error and possible overlap by peaks
peaks is absent from the diffraction pattern of the sample, then
ofothercomponentsaretakenintoaccount.Onceacomponent
the suspected component is not present in the sample. (Excep-
inthesampleisidentified,makesurethatthecorrespondingset
tion: If a component has one or more peaks with relative
of peaks is either labeled or crossed off the list of peak
intensitymuchgreaterthanitsotherpeaksandispresentatlow
observed for the sample. However, a peak may be left on the
concentration,thenitmaynotbepossibletoobserveitsweaker
list for further consideration if the observed intensity signifi-
cantly exceeds the intensity cited in the reference file, thus
Alphabetical Index–Inorganic Phases, Catalog No. Al42, ICDD. suggesting that a peak of another component overlaps the one
TABLE 1 Common Pigments and Extenders for Paint
ICDD File
A
d-Value and Intensity Name Formula
Number
B
17.6 9.0 4.49 3.58 1.504 bentonite Na (AlMg) Si O 12-219
x 5 8 4 6 0.3 2 4 10
(OH) ·H O
2 2
B
10.1 4.49 3.66 3.36 2.565 mica Kal Si AlO (OH) 7-25
x 9 6 x 9 2 3 10 2
B
9.34 4.66 3.116 2.476 1.870 talc Mg Si O (OH) 13-558
x 9 x 7 4 3 4 10 2
7.63 4.283 3.065 2.873 2.685 gypsum CaSO ·2H O 33-311
x x 8 5 4 4 2
7.36 4.56 3.66 2.451 1.531 chrysotile-20rcl Mg Si O (OH) 25-645
x 5 8 7 7 3 2 5 4
7.31 4.57 3.65 2.27 1.535 chrysotile-2Mcl Mg Si O (OH) 31-808
x 5 7 3 5 3 2 5 4
B
7.17 4.366 4.186 3.579 2.495 kaolinite Al Si O (OH) 14-164
x 6 5 8 5 2 2 5 4
B
4.568 9.12 4.410 3.460 2.853 zinc phosphate Zn (PO ) ·H O 37-465
x 6 2 3 7 3 4 2 2
4.18 2.69 2.45 2.19 1.72 yellow iron oxide FeO(OH) 29-713
x 4 5 2 2
4.040 3.136 2.841 2.487 2.486 crystobalite SiO 39-1425
x 1 1 1 0 2
3.52 2.370 1.892 1.700 1.667 anatase TiO 21-1272
x 2 4 2 2 2
3.445 3.319 3.103 2.121 2.106 barium sulfate BaSO 24-1035
x 7 x 8 8 4
3.39 6.32 2.986 2.840 2.269 chrome orange Pb (OH) CrO 8-437
x 2 8 4 2 2 2 4
3.38 2.903 2.787 2.632 1.755 red lead Pb O 8-19
x 5 5 3 3 3 4
3.342 4.257 2.457 1.818 1.542 quartz SiO 33-1161
x 2 8 1 9 2
3.310 3.129 2.926 1.9103 1.7642 zinc sulfide ZnS 36-1450
x 8 9 8 5
3.28 4.96 4.38 3.48 3.03 lead chromate PbCrO 8-209
x 3 3 6 7 4
3.260 9.79 5.771 4.251 3.130 lead oxide sulfate Pb O SO ·H O 29-78
...