ASTM D6038-05

These test methods provide a means of determining the compatibility of a resin (or vehicle), at low concentrations, in a high boiling ink solvent.

Resin-solvent mixtures that exhibit a high precipitation temperature are less compatible than those exhibiting a low precipitation temperature.

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.

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 210C.

1.2 The manual procedure in this test method uses laboratory equipment generally available in a normal, well-equipped laboratory. The automated procedure uses the Chemotronic Cloudpoint 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, 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° (140°F) as determined by Test Method D 56. Users of this test method should be aware that the flash point of many solvents used for this test (as defined in Test Methods D 56 and D 1310) 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 the standard. The values given in parentheses are for information only.

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 and health practices and determine the applicability of regulatory limitations prior to use.