ASTM D2745-00(2008)
(Test Method)Standard Test Method for Relative Tinting Strength of White Pigments by Reflectance Measurements
Standard Test Method for Relative Tinting Strength of White Pigments by Reflectance Measurements
SIGNIFICANCE AND USE
Tinting strength is one of the most important properties of a white pigment. This test method provides a means of testing this property for quality control.
This test method is a referee method, and the vehicle for preparing the dispersion and the black for tinting are suggested, but others may be used provided both the purchaser and the seller agree to the changes.
The results obtained with a muller do not necessarily agree with industrial situations where different dispersing conditions exist. However, dispersing with a muller is a fast, relatively inexpensive way of testing tinting strength for routine quality control.
SCOPE
1.1 This test method describes the procedure for determining the relative tinting strength of white pigments by reflectance measurements of black tints.
1.2 This test method is applicable only for comparing the test pigment with a reference standard of the same type and grade.
Note 1—Test Method D 332 describes a procedure for visual assessment of blue-tinted samples.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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.
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Designation:D2745 −00(Reapproved 2008)
Standard Test Method for
Relative Tinting Strength of White Pigments by Reflectance
Measurements
This standard is issued under the fixed designation D2745; 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 are made of the paint and the Y tristimulus values (green-filter
reflectance) of the wet films are measured. The relative tinting
1.1 This test method describes the procedure for determin-
strength of the test pigment is calculated directly from the
ing the relative tinting strength of white pigments by reflec-
reflectance values.
tance measurements of black tints.
1.2 This test method is applicable only for comparing the
4. Significance and Use
test pigment with a reference standard of the same type and
4.1 Tinting strength is one of the most important properties
grade.
of a white pigment. This test method provides a means of
NOTE 1—Test Method D332 describes a procedure for visual assess-
testing this property for quality control.
ment of blue-tinted samples.
4.2 This test method is a referee method, and the vehicle for
1.3 The values stated in SI units are to be regarded as the
preparingthedispersionandtheblackfortintingaresuggested,
standard. The values given in parentheses are for information
but others may be used provided both the purchaser and the
only.
seller agree to the changes.
1.4 This standard does not purport to address all of the
4.3 The results obtained with a muller do not necessarily
safety concerns, if any, associated with its use. It is the
agree with industrial situations where different dispersing
responsibility of the user of this standard to establish appro-
conditions exist. However, dispersing with a muller is a fast,
priate safety and health practices and determine the applica-
relatively inexpensive way of testing tinting strength for
bility of regulatory limitations prior to use.
routine quality control.
2. Referenced Documents
5. Apparatus and Materials
2.1 ASTM Standards:
5.1 Muller, automatic, equipped with a weight that exerts a
D332 Test Method for Relative Tinting Strength of White
permanent 220-N (50-lbf) and an additional weight exerting a
Pigments by Visual Observation
50-lbf making a total of 445-N (100-lbf). The two glass plates
D2244 Practice for Calculation of Color Tolerances and
shallbekeptsharpbyremovingfromthemachineandgrinding
Color Differences from Instrumentally Measured Color
them face-to-face with No. 303 optical emery or equivalent,
Coordinates
and water.
5.2 Spatula—A flexible spatula having a chromium-plated
3. Summary of Test Method
or plastic blade 75 to 150 mm (3 to 6 in.) long, and another
3.1 Pigment is dispersed in a vehicle and let down with
with a 75 mm (3-in.) tapered blade.
additional vehicle that has been tinted. Dispersion and letdown
5.3 Balances—(1) A balance sensitive to 20 mg and (2)an
are accomplished with a mechanical muller. Both the test and
analytical balance sensitive to 0.4 mg.
standard pigments are treated identically. Opaque drawdowns
5.4 Vehicle—Because the choice of vehicle may affect
results, a solvent-free vehicle (excluding refined or low-bodied
This test method is under the jurisdiction of ASTM Committee D01 on Paint
linseed oil) should be agreed upon by the purchaser and the
and Related Coatings, Materials, andApplications and is the direct responsibility of
seller.
Subcommittee D01.26 on Optical Properties.
Current edition approved Feb. 1, 2008. Published March 2008. Originally
5.5 Tinting Black—A lamp black predispersed in a vehicle
approved in 1968. Last previous edition approved in 2000 as D2745 – 00. DOI:
similar in nature to the test vehicle. Tinting black should be
10.1520/D2745-00R08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or agreed upon between the purchaser and the seller.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.6 Chart—Either gray or white lacquered charts cut to a
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. convenient size.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2745−00(2008)
balance. Remove and transfer vehicle employing the spatula ultimately
5.7 Color Measuring Instruments , meeting the require-
intended for preparing a paste on the muller. Use the weigh-by-difference
ments of Practice D2244.
method. (2)Add the vehicle to a tared metal or plastic plate till the correct
5.8 Film Applicator—50 or 75 mm (2 or 3 in.) wide with a
weight is reached; transfer to the muller by scraping off the plate with the
spatula. If the vehicle tends to run, weigh both pigment and vehicle on the
clearanceof150µm(6mils)toproducewetfilmsabout75µm
plate making a crater in the pile of pigment to contain the vehicle.
(3 mils ) thick. This applicator when used as suggested in the
7.4 Standardize the color measuring instrument for mea-
test method will produce an R film.
∞
surement of the green filter reflectance (that is, Y-value) with,
6. Standard
if necessary, a wet-film adapter in place. Adjust the color
instrument to the approximate expected reading. Draw down
6.1 Astandardwhitepigmentofthesametypeasthesample
the sample paint on the chart (lacquered side) with the
to be tested, as agreed upon by the purchaser and the seller.
applicator blade (5.8). Place the film immediately on the
7. Procedure
reading port, cover the back of the chart with a flat, black panel
(for example, black structural glass) to keep the chart flat and
7.1 Place two concentric circles under the base plate of the
prevent exterior light from entering the color measuring
muller so that they can be clearly seen through the plate. The
instrument, and read the reflectance immediately (Note 3),
circles can be drawn on a paper and inserted under the plate, or
recording the value. Clean the port of the colorimeter thor-
they can be drawn directly on the underside of the bottom
1 oughly with a rag. Draw down the standard paint and read
plate. The inner circle should be 63 mm (
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D2745–93 Designation: D 2745 – 00 (Reapproved 2008)
Standard Test Method for
Relative Tinting Strength of White Pigments by Reflectance
Measurements
This standard is issued under the fixed designation D 2745; 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
1.1 This test method describes the procedure for determining the relative tinting strength of white pigments by reflectance
measurements of black tints.
1.2 This test method is applicable only for comparing the test pigment with a reference standard of the same type and grade.
NOTE 1—Test Method D 332 describes a procedure for visual assessment of blue tinted samples.
1.3This standard does not purport to address all of the safety problems, 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. describes a procedure for visual assessment of blue-tinted samples.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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.
2. Referenced Documents
2.1 ASTM Standards:
D 332 Test Method for Relative Tinting Strength of White Pigments by Visual Observation
E97Test Method for Directional Reflectance Factor, 45-deg 0-deg, of Opaque Specimens by Broad-Band Filter Reflectometry
D 2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
3. Summary of Test Method
3.1 Pigment is dispersed in a vehicle and let down with additional vehicle that has been tinted. Dispersion and letdown are
accomplished with a mechanical muller. Both the test and standard pigments are treated identically. Opaque drawdowns are made
of the paint and the Y tristimulus values (green-filter reflectance) of the wet films are measured. The relative tinting strength of
the test pigment is calculated directly from the reflectance values.
4. Significance and Use
4.1 Tinting strength is one of the most important properties of a white pigment. This test method provides a means of testing
this property for quality control.
4.2 This test method is a referee method, and the vehicle for preparing the dispersion and the black for tinting are suggested,
but others may be used provided both the purchaser and the seller agree to the changes.
4.3 The results obtained with a muller do not necessarily agree with industrial situations where different dispersing conditions
exist. However, dispersing with a muller is a fast, relatively inexpensive way of testing tinting strength for routine quality control.
5. Apparatus and Materials
5.1 Muller, automatic, equipped with a weight that exerts a permanent 50-lbf (220-N)220-N (50-lbf) and an additional weight
exerting a 50-lbf making a total of 100-lbf (445-N).445-N (100-lbf). The two glass plates shall be kept sharp by removing from
the machine and grinding them face-to-face with No. 303 optical emery or equivalent, and water.
5.2 Spatula—A flexible spatula having a chromium-plated or plastic blade 3 to 6 in. (75 to 150 mm) long and another with a
This test method is under the jurisdiction of ASTM Committee D-1D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.26 on Optical Properties.
Current edition approvedSept.15,1993.Feb.1,2008.PublishedNovember1993.March2008.OriginallypublishedasD2745–68T.approvedin1968.Lastpreviousedition
D2745–89.approved in 2000 as D 2745 – 00.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 06.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2745 – 00 (2008)
3-in. tapered blade. —A flexible spatula having a chromium-plated or plastic blade 75 to 150 mm (3 to 6 in.) long, and another
with a 75 mm (3-in.) tapered blade.
5.3 Balances—(1) A balance sensitive to 20 mg and (2) an analytical balance sensitive to 0.4 mg.
5.4 Vehicle—Because the choice of vehicle may affect results, a solvent-free vehicle (excluding refined or low-bodied linseed
oil) should be agreed upon by the purchaser and the seller.
5.5 Tinting Black—A lamp black predispersed in a vehicle similar in nature to the test vehicle. —A lamp black predispersed
in a vehicle similar in nature to the test vehicle. Tinting black should be agreed upon between the purchaser and the seller.
5.6 Chart—Either gray or white lacquered charts cut to a convenient size.
5.7 Colorimeter—Afilter colorimeter meeting the requirements of Test Method E97Color Measuring Instruments , meeting the
requirements of Practice D 2244.
5.8 Film Applicator—2 or 3 in. (50 or 75 mm) wide with a clearance of 6 mils (150 µm) to produce wet films about 3 mils (75
µm) thick. This applicator when used as suggested in the test method will produce an —50 or 75 mm (2 or 3 in.) wide with a
clearance of 150 µm ( 6 mils) to produce wet films about 75 µm (3 mils ) thick. This applicator when used as suggested in the test
method will produce an R film.
`
6. Standard
6.1 A standard white pigment of the same type as the sample to be tested, as agreed upon by the purchaser and the seller.
7. Procedure
7.1 Place two concentric circles under the base plate of the muller so that they can be clearly seen through the plate. The circles
can be drawn on a paper and inserted under the plate, or they can be drawn directly on the underside of the bottom plate.The inner
1 1 1 1
circle should be 2 ⁄2 in. (63 mm)63 mm (2 ⁄2 in.) in diameter and the outer circle 4 ⁄2 in. (114 mm)114 mm (4 ⁄2 in.) in diameter.
7.2 Make a preliminary test by dispersing standard white pigment in a clear vehicle at the pigment volume concentration (PVC)
giveninTable1andaddingtintingblacktodeterminetheamountofblackrequiredtoprovideareflectivityof0.42 60.03.Prepare
a “black letdown vehicle” by adding tinting black to clear vehicle so that
...
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