ASTM D6038-21

Standard Test Methods for Determining the Compatibility of Resin/Solvent Mixtures by Precipitation Temperature (Cloud Point)

SIGNIFICANCE AND USE
5.1 These test methods provide a means of determining the compatibility of a resin (or vehicle), at low concentrations, in a high boiling ink solvent.  
5.2 Resin-solvent mixtures that exhibit a high precipitation temperature are less compatible than those exhibiting a low precipitation temperature.  
5.3 Resin-solvent mixtures that exhibit precipitation temperatures at or close to the cloud point of the pure solvent are considered infinitely compatible or the resin is infinitely soluble in that solvent.
SCOPE
1.1 These test methods cover the manual and automatic procedures for testing the compatibility of lithographic ink resins in high boiling ink solvents by precipitation temperature (cloud point) in a range from 35 to 210°C.  
1.2 The manual procedure in this test method uses laboratory equipment generally available in a normal, well-equipped laboratory. The automated procedure uses a programmable cloud point tester.  
1.3 This test method is for use with ink resins intended mainly for oil-based offset and letterpress inks. The type of resins are typically, but not limited to C9 aromatic hydrocarbon resins, modified dicyclopentadiene resins, rosin pentaerythritol or glycerol esters, phenolic modified rosin esters, maleic anhydride modified-rosin esters, and naturally occurring resins such as gilsonite.  
1.4 A resin solution or ink vehicle could also be used in this test instead of the resin.  
1.5 The typical high boiling solvents to be used are C12 to C16 petroleum distillates.  
1.6 To avoid fire or injury, this test method should not be used with low flash point solvents such as toluene or xylene. The minimum flash point of the solvents used should be 60°C as determined by Test Method D56.  
Note 1: Users of this test method should be aware that the flash point of many solvents used for this test (as defined in Test Methods D56 and D1310) is exceeded in the heating cycle of this test method. Safety precautions should be taken since there is the potential for vapor ignition. The method outlined should be done in a shielded exhaust hood, where there is access to a fire extinguisher if needed.  
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.8 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.  
1.9 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: 83.040.01 - Raw materials for rubber and plastics in general
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.37 - Ink Vehicles

Relations

• Refers: ASTM D56-16 - Standard Test Method for Flash Point by Tag Closed Cup Tester
• Effective Date: 01-Jun-2016
• 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 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 D1310-01(2007) - Standard Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus
• 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 D56-05 - Standard Test Method for Flash Point by Tag Closed Cup Tester
• Effective Date: 01-May-2005
• Refers: ASTM D56-02a - Standard Test Method for Flash Point by Tag Closed Cup Tester
• Effective Date: 10-Dec-2002
• Refers: ASTM D56-02 - Standard Test Method for Flash Point by Tag Closed Tester
• Effective Date: 10-Jun-2002
• Refers: ASTM D1310-01 - Standard Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus
• Effective Date: 10-Dec-2001
• Refers: ASTM D1310-86(1997)e1 - Standard Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus
• Effective Date: 10-Dec-2001
• Refers: ASTM D56-01 - Standard Test Method for Flash Point by Tag Closed Tester
• Effective Date: 10-Aug-2000
• Refers: ASTM D56-00 - Standard Test Method for Flash Point by Tag Closed Tester
• Effective Date: 10-Aug-2000
• 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 D6038-21: Standard Test Methods for Determining the Compatibility of Resin/Solvent Mixtures by Precipitation Temperature (Cloud Point) provides recognized procedures to evaluate resin and solvent compatibility in ink formulation. This standard, published by ASTM International, outlines both manual and automated test methods to determine the cloud point-where a resin/solvent mixture transitions from clear to turbid-within the temperature range of 35°C to 210°C. These procedures are essential for the quality control and development of oil-based lithographic offset and letterpress printing inks, helping ensure consistent performance across a wide variety of ink formulations.

Key Topics

• Purpose and Significance
  The standard allows for the assessment of compatibility by measuring the precipitation (cloud) temperature. This measurement helps ink manufacturers and formulators:

  • Identify the most suitable resin/solvent combinations
  • Predict ink stability and processability
  • Optimize formulation for performance and cost-effectiveness

• Test Methods

  • Manual Method: Utilizes standard laboratory equipment to heat and cool resin/solvent samples, observing the temperature at which clouding occurs.
  • Automated Method: Employs a programmable cloud point tester for automated heating, cooling, and detection, ensuring reliable, repeatable results.

• Material Scope

  • Applicable primarily to oil-based offset and letterpress printing ink resins, e.g.:
    • C9 aromatic hydrocarbon resins
    • Modified dicyclopentadiene resins
    • Rosin pentaerythritol or glycerol esters
    • Phenolic modified rosin esters
    • Maleic anhydride modified rosin esters
    • Naturally occurring resins such as gilsonite
  • Solvent scope is primarily high boiling petroleum distillates (C12–C16).

• Safety Considerations

  • Only solvents with a flash point of at least 60°C should be used.
  • The method covers operation precautions to avoid fire or injury, including performing procedures in a shielded exhaust hood with fire extinguisher access.

Applications

• Ink Formulation and Quality Control
  ASTM D6038-21 is commonly used by ink manufacturers, formulators, and quality assurance labs to:

  • Select compatible resin and solvent systems for offset and letterpress inks
  • Troubleshoot solubility and performance issues in ink blends
  • Compare resin compatibility during resin selection or substitution
  • Validate and document ink vehicle stability under manufacturing and storage conditions

• Research and Development
  The test methods assist researchers in developing new resin or solvent systems by allowing rapid screening for compatibility and solubility.

• Vendor and Customer Specifications

  • Enables clear communication of ink vehicle properties between resin suppliers, ink manufacturers, and end users
  • Supports compliance with regulatory and safety requirements, particularly regarding solvent flash points and environmental practices

Related Standards

• ASTM D56
  Standard Test Method for Flash Point by Tag Closed Cup Tester
  Provides procedures for determining the minimum flash point of solvents recommended in D6038-21.

• ASTM D1310
  Standard Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus
  Referenced for safety and fire precautions for ink solvent usage.

• ASTM E691
  Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
  Methodology used as the basis for D6038-21’s precision and reproducibility statements.

By following ASTM D6038-21, ink and resin formulators can ensure reliable, reproducible measurement of resin/solvent compatibility, contributing to superior ink performance and safer manufacturing practices. This standard provides a critical benchmark for quality and process control within the printing ink industry.

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: D6038 − 21
Standard Test Methods for
Determining the Compatibility of Resin/Solvent Mixtures by
Precipitation Temperature (Cloud Point)
This standard is issued under the fixed designation D6038; 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* 1.8 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 These test methods cover the manual and automatic
responsibility of the user of this standard to establish appro-
procedures for testing the compatibility of lithographic ink
priate safety, health, and environmental practices and deter-
resins in high boiling ink solvents by precipitation temperature
mine the applicability of regulatory limitations prior to use.
(cloud point) in a range from 35 to 210°C.
1.9 This international standard was developed in accor-
1.2 The manual procedure in this test method uses labora-
dance with internationally recognized principles on standard-
tory equipment generally available in a normal, well-equipped
ization established in the Decision on Principles for the
laboratory. The automated procedure uses a programmable
Development of International Standards, Guides and Recom-
cloud point tester.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.3 This test method is for use with ink resins intended
mainly for oil-based offset and letterpress inks. The type of
2. Referenced Documents
resins are typically, but not limited to C aromatic hydrocarbon
2.1 ASTM Standards:
resins, modified dicyclopentadiene resins, rosin pentaerythritol
D56 Test Method for Flash Point by Tag Closed Cup Tester
or glycerol esters, phenolic modified rosin esters, maleic
D1310 TestMethodforFlashPointandFirePointofLiquids
anhydride modified-rosin esters, and naturally occurring resins
by Tag Open-Cup Apparatus
such as gilsonite.
E180 Practice for Determining the Precision of ASTM
1.4 Aresin solution or ink vehicle could also be used in this
Methods for Analysis and Testing of Industrial and Spe-
test instead of the resin. 3
cialty Chemicals (Withdrawn 2009)
1.5 The typical high boiling solvents to be used are C to E691 Practice for Conducting an Interlaboratory Study to
C petroleum distillates. Determine the Precision of a Test Method
1.6 To avoid fire or injury, this test method should not be
3. Terminology
used with low flash point solvents such as toluene or xylene.
3.1 Definitions:
The minimum flash point of the solvents used should be 60°C
3.1.1 cloud point, n—(precipitation temperature) the tem-
as determined by Test Method D56.
perature at which a resin/solvent mixture changes from clear to
NOTE 1—Users of this test method should be aware that the flash point
turbid and opaque.
of many solvents used for this test (as defined in Test Methods D56 and
3.1.2 compatibility, n—resin and solvent mixture forms a
D1310) is exceeded in the heating cycle of this test method. Safety
clear, homogeneous, and stable solution at room temperature.
precautions should be taken since there is the potential for vapor ignition.
The method outlined should be done in a shielded exhaust hood, where
3.1.3 incompatibility, n—resin and solvent mixture does not
there is access to a fire extinguisher if needed.
form a uniform solution and may be in two phases or opaque.
1.7 The values stated in SI units are to be regarded as
3.1.4 n—degrees of freedom.
standard. No other units of measurement are included in this
3.1.5 precipitation,n—resinseparatesfromtheresin/solvent
standard.
mixture.
1 2
These test methods are under the jurisdiction of ASTM Committee D01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Paint and Related Coatings, Materials, and Applications and are the direct contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
responsibility of Subcommittee D01.37 on Ink Vehicles. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2021. Published February 2021. Originally the ASTM website.
approved in 1996. Last previous edition approved in 2014 as D6038 – 14. DOI: The last approved version of this historical standard is referenced on
10.1520/D6038-21. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6038 − 21
3.1.6 solubility, n—the degree of resin compatibility in a 7.5 Hot Air Gun, suitable to reach 260°C.
given solution.
7.6 Auxiliary Equipment, (that is, mixing loop (if desired),
lab stand, and test tube clamp, 500-ml beaker for cooling, etc.).
4. Summary of Test Method
4.1 A 10 % by weight mixture of the resin (or ink vehicle)
8. Sample Preparation
to be tested in the reference solvent (or vice versa) is heated in
8.1 Crush the solid resin to particles not larger than 2 mm
a test tube and stirred until a clear solution is obtained.
and preferably not larger than 1 mm .
4.2 The solution is allowed to cool. The cloud point is the
lowest temperature that can be read on a thermometer, posi-
9. Procedure
tioned at the back wall of the test tube, or in the case of the
9.1 Weigh 2.00 6 0.02 g of crushed resin and 18.00 6
automated tester, before the solution reaches the preset turbid-
0.02 g of the solvent to be tested into the test tube.
ity level.
9.2 Place test tube with the sample, the thermometer, and
4.3 If the solution remains clear at room temperature, the
the optional mixing loop in a tube clamp.
test tube is cooled (cold water, ice water, or dry ice/acetone
9.3 Aim the heat gun from below at the bottom of the test
bath) until the cloud point can be recorded.
tube (keep nozzle at least 25 mm from tube), and turn on.
5. Significance and Use
9.4 Mix resin and solvent slowly as heat rises.
5.1 These test methods provide a means of determining the
NOTE 3—To avoid loss of solvent while stirring, do not remove the
compatibility of a resin (or vehicle), at low concentrations, in
stirring apparatus from the mixture.
a high boiling ink solvent.
9.5 Warning—Care must be taken in stirring the resin/
5.2 Resin-solvent mixtures that exhibit a high precipitation
solvent mixture not to drop the thermometer or stirring loop.
temperature are less compatible than those exhibiting a low
This could cause the test tube to break, which could cause a
precipitation temperature.
serious fire or accident.
5.3 Resin-solvent mixtures that exhibit precipitation tem-
9.6 Heatto200°C;holdthistemperaturefor2min,andthen
peratures at or close to the cloud point of the pure solvent are
remove the heat source.
considered infinitely compatible or the resin is infinitely
NOTE 4—Low softening point and very compatible resins will dissolve
soluble in that solvent.
at temperatures well below 200°C. The maximum temperature to dissolve
such resin and solvent mixtures can be much lower than 200°C. In such
6. Reagents and Materials
cases the maximum temperature for the test should be one agreed upon
6.1 Resins, (for example, modified hydrocarbon, or rosin between the customer and the supplier and recorded.
ester resins, or both) or Ink Vehicle.
9.7 Check to see that all resin is dissolved.
6.2 Solvents, will be those commonly used for making
9.8 Start to blow ambient air from the heat gun onto the test
lithographic ink vehicles, for example, hydrocarbon petroleum
tube.
distillate C to C as agreed upon by producer and user.
12 16
9.8.1 If the mixture is not clear after heating for 2 min at
200°C, continue to heat up to 250°C or until dissolution has
NOTE 2—The use of ink industry recognized Test Ink Oils are
recommended for evaluating resins. The Test Ink Oils are controlled from occurred and keep 2 min at that temperature, record the
lot to lot to ensure meaningful data. (Contact NAPIM for a list of
temperature at dissolution. Start the cooling procedure at this
approved Test Ink Oils).
point.
6.3 Calibration Materials, PRIFRAC 2981 stearic acid and
9.8.2 If after the hold time of 2 min, in either case, the
Haltermann N-C16 oil designated for automatic method only mixture is clear except for a very slight presence of precipitate,
but can be used for manual method.
start the cooling procedure and note the presence of “slight
precipitate.”
MANUAL METHOD
9.8.3 If the mixture does not become clear or exhibits
significant precipitation, record it as incompatible.
7. Apparatus
NOTE 5—Make sure that in case of 9.8.2 or 9.8.3 the cause of the lack
7.1 Balance or Scale, weighing to 60.02 g accuracy and a
of dissolution is NOT too large initial particles due to insufficient
minimum 250 g capacity.
crushing.
7.2 Heat-Resistant Test Tube, 25–mm width by 150–mm
9.9 Observe mixture closely as temperature drops and
height.
record the approximate rate of cooling, and the temperature at
which solution becomes so cloudy that the thermometer, when
7.3 Thermometer, 0 to 250°C range.
held at the back wall of the test tube, can no longer be read (or
7.4 Thermometer, -100 to 50°C range.
the thermometer fluid can no longer be seen). This observation
is defined as the precipitation temperature or cloud point (see
National Association of Printing Ink Manufacturers (NAPIM), 581 Main St.,
Note 6 and Note 7).
Woodbridge, NJ 07095, ([e-mail]).
Available from IGTTesting S
...

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: D6038 − 14 D6038 − 21
Standard Test Methods for
Determining the Compatibility of Resin/Solvent Mixtures by
Precipitation Temperature (Cloud Point)
This standard is issued under the fixed designation D6038; 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*
1.1 These test methods cover the manual and automatic procedures for testing the compatibility of lithographic ink resins in high
boiling ink solvents by precipitation temperature (cloud point) in a range from 35 to 210°C.
1.2 The manual procedure in this test method uses laboratory equipment generally available in a normal, well-equipped laboratory.
The automated procedure uses a programmable cloudpoint cloud point tester.
1.3 This test method is for use with ink resins intended mainly for oil-based offset and letterpress inks. The type of resins are
typically, but not limited to C aromatic hydrocarbon resins, modified dicyclopentadiene resins, rosin pentaerythritol or glycerol
esters, phenolic modified rosin esters, maleic anhydride modified-rosin esters, and naturally occurring resins such as gilsonite.
1.4 A resin solution or ink vehicle could also be used in this test instead of the resin.
1.5 The typical high boiling solvents to be used are C to C petroleum distillates.
12 16
1.6 To avoid fire or injury, or both, to the operator, this test method should not be used with low flash point solvents such as toluene
or xylene. The minimum flash point of the solvents used should be 60°C as determined by Test Method D56.
NOTE 1—Users of this test method should be aware that the flash point of many solvents used for this test (as defined in Test Methods D56 and D1310)
is exceeded in the heating cycle of this test method. Safety precautions should be taken since there is the potential for vapor ignition. The method outlined
should be done in a shielded exhaust hood, where there is access to a fire extinguisher if needed.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.9 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.
These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility of
Subcommittee D01.37 on Ink Vehicles.
Current edition approved Jan. 1, 2014Feb. 1, 2021. Published January 2014February 2021. Originally approved in 1996. Last previous edition approved in 20052014 as
ε1
D6038 – 05D6038 – 14. . DOI: 10.1520/D6038-14.10.1520/D6038-21.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6038 − 21
2. Referenced Documents
2.1 ASTM Standards:
D56 Test Method for Flash Point by Tag Closed Cup Tester
D1310 Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
(Withdrawn 2009)
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions:
3.1.1 cloud point, n—(precipitation temperature) the temperature at which a resin/solvent mixture changes from clear to turbid and
opaque.
3.1.2 compatibility, n—resin and solvent mixture forms a clear, homogeneous, and stable solution at room temperature.
3.1.3 incompatibility, n—resin and solvent mixture does not form a uniform solution and may be in two phases or opaque.
3.1.4 n—degrees of freedom.
3.1.5 precipitation, n—resin separates from the resin/solvent mixture.
3.1.6 solubility, n—the degree of resin compatibility in a given solution.
4. Summary of Test Method
4.1 A 10 % by weight mixture of the resin (or ink vehicle) to be tested in the reference solvent (or vice versa) is heated in a test
tube and stirred until a clear solution is obtained.
4.2 The solution is allowed to cool. The cloud point is the lowest temperature that can be read on a thermometer, positioned at
the back wall of the test tube, or in the case of the automated tester, before the solution reaches the preset turbidity level.
4.3 If the solution remains clear at room temperature, the test tube is cooled (cold water, ice water, or dry ice/acetone bath) until
the cloud point can be recorded. (Cooling below ambient temperature can only be done in the manual method.)
5. Significance and Use
5.1 These test methods provide a means of determining the compatibility of a resin (or vehicle), at low concentrations, in a high
boiling ink solvent.
5.2 Resin-solvent mixtures that exhibit a high precipitation temperature are less compatible than those exhibiting a low
precipitation temperature.
5.3 Resin-solvent mixtures that exhibit precipitation temperatures at or close to the cloud point of the pure solvent are considered
infinitely compatible or the resin is infinitely soluble in that solvent.
6. Reagents and Materials
6.1 Resins, (for example, modified hydrocarbon, or rosin ester resins, or both) or Ink Vehicle.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
D6038 − 21
6.2 Solvents, will be those commonly used for making lithographic ink vehicles, for example, hydrocarbon petroleum distillate
C to C as agreed upon by producer and user.
12 16
NOTE 2—The use of ink industry recognized Test Ink Oils are recommended for evaluating resins. The Test Ink Oils are controlled from lot to lot to ensure
meaningful data. (Contact NAPIM for a list of approved Test Ink Oils).
6.3 Calibration Materials, PRIFRAC 2981 stearic acid and Haltermann N-C16 oil designated for automatic method only but can
be used for manual method.
MANUAL METHOD
7. Apparatus
7.1 Balance or Scale, weighing to 60.02 g accuracy and a minimum 250 g capacity.
7.2 Heat-Resistant Test Tube, 25–mm width by 150–mm height.
7.3 Thermometer, 0 to 250°C range.
7.4 Thermometer, -100 to 50°C range.
7.5 Hot Air Gun,, 260 to 399°C, 120 volts, alternating current (VAC), 60 HZ, 14A.suitable to reach 260°C.
7.6 Auxiliary Equipment, (that is, mixing loop (if desired), lab stand, and test tube clamp, 500-mL500-ml beaker for cooling, etc.).
8. Sample Preparation
23 3
8.1 PulverizeCrush the solid resin to a size no particles not larger than 32 mm and preferably not larger than 1 mm .
9. Procedure
9.1 Weigh 2.00 6 0.02 g of pulverized crushed resin and 18.00 6 0.02 g 0.02 g of the solvent to be tested into the test tube.
9.2 Place test tube in tube with the sample in a tube clamp with the thermometer and mixing loop (optional).with the sample, the
thermometer, and the optional mixing loop in a tube clamp.
9.3 Aim the heat gun from below at the bottom of the test tube (keep nozzle at least 25.425 mm from tube), and turn on.
9.4 Mix resin and solvent slowly as heat rises.
NOTE 3—To avoid loss of solvent while stirring, do not remove the stirring apparatus from the mixture.
9.5 Warning—WarningCare—Care must be taken in stirring the resin/solvent mixture not to drop the thermometer or stirring
loop. This could cause the test tube to break, which could cause a serious fire or accident.
9.6 Heat to 200°C; hold this temperature for 2 min, and then remove the heat source.
NOTE 4—Low softening point and very compatible resins will dissolve at temperatures well below 200°C. The maximum temperature to dissolve such
National Association of Printing Ink Manufacturers (NAPIM), 581 Main St., Woodbridge, NJ 07095, ([e-mail]).
Available from Testprint B. V., Zilverweg 10, PO Bos 127, 8440 AC Heerenveen, IGT Testing Systems, Randstad 22-2, P.O.box 22022, 1316 BX Almere, The
Netherlands.
D6038 − 21
resin and solvent mixtures can be much lower than 200°C. In such cases the maximum temperature for the test should be one agreed upon between the
customer and the supplier.supplier and recorded.
9.7 Check to see that all resin is dissolved.
9.8 Start to blow ambient air from the heat gun onto the test tube.
9.8.1 If the mixture is not clear after heating for 2 min at 200°C, continue to heat up to 250°C or until dissolution has occurred.
occurred and keep 2 min at that temperature, record the temperature at dissolution. Start the cooling procedure at this point.
9.8.2 If the after the hold time of 2 min, in either case, the mixture is clear except for a very slight presence of precipitate, continue
to end pointstart the cooling procedure and note the presence of “slight precipitate.”
9.8.3 If the mixture does not become clear or exhibits significant precipitation, record it as incompatible.
NOTE 5—Make sure that in case of 9.8.2 or 9.8.3 the cause of the lack of dissolution is NOT too large initial particles due to insufficient crushing.
9.9 Observe mixture closely as temperature drops and record the approximate rate of cooling, and the temperature at which
solution becomes so cloudy that the thermometer, when held at the back wall of the test tube, can no longer be read (or the
thermometer fluid can no longer be seen). This is observation is defined as the precipitation temperature or cloud point (see Note
56 and Note 67).
NOTE 6—Cooling water, ice water, or a dry ice/acetone bath and a low temperature thermometer may be needed to reach the precipitation temperature
for very soluble resins.
NOTE 7—This test method is recommended for resins and solvent mixtures exhibiting a precipitation temperature between 50 and 180°C at 10 % resin
solids. If a mixture is out of that range, a change in resin concentration (for example, 20 % solids) or solvent is recommended.
10. Report
10.1 A report on precipitation temperature should note the following information:
10.1.1 The Method Used—MANUAL;
10.1.2 Sample i
...