1、Designation: D 5166 97 (Reapproved 2003)Standard Practice forLaboratory Preparation of Gelled Vehicle Samples Using aMicrowave Oven1This standard is issued under the fixed designation D 5166; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice outlines a procedure for preparing gelledvehicle samples using a microwave oven.1.
3、2 The test samples can be used for characterizing thegelability or reactivity of resins, gelling agents, and vehiclesused in the manufacture of oil based printing inks, or both.1.3 Evaluation of the gelled vehicles may, depending uponpreference, be either visual or instrumental.1.4 This standard doe
4、s not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Stan
5、dards:D 154 Guide for Testing Varnishes2D 1545 Test Method for Viscosity of Transparent Liquidsby Bubble Time Method2D 1725 Test Method for Viscosity of Resin Solutions2D 4040 Test Method for Viscosity of Printing Inks andVehicles by Falling-Rod Viscometer3E 1 Specification for ASTM Thermometers43.
6、Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 gelAny resin solution, or more complex blend ofresins and alkyds that has been cooked or reacted with a gellingor cross-linking agent to build molecular weight and thatexhibits a pseudoplastic rheology. (Also called “gelled ve-hicle
7、.”)3.1.2 gelling agentin the context of ink resins and ve-hicles, gelling agents or gellants are typically organo-aluminum compounds that react with carboxylic acid andhydroxyl groups present on the backbone of resins and alkydsto form cross-linked networks. (Also called “gellant.”)3.1.3 gel lengthR
8、eferences to long, medium, and short gellength refer to the length of a string of gelled vehicle observedwhen pulling apart a small sample of vehicle with a spatula(that is, a long gel is very fluid and forms a “long” filament; ashort gel has little flow and forms a “short” filament).3.1.4 pregelThe
9、 resin solution or vehicle componentscomprising the vehicle prior to the addition of gelling agentand viscosity adjusting solvent. (Also called “pregel vehicle.”)4. Summary of Practice4.1 Prepare a pregel resin solution or vehicle.4.2 Separate the pregel vehicle into five or more aliquots towhich va
10、rious levels of gellant are added. Alternately, variousgellants can be added at a given concentration to compare theireffectiveness.4.3 Place the test samples on a turntable in the microwaveoven and heat the samples at full power until the desired testtemperature is attained.4.4 After the prescribed
11、 waiting period, test and ratesamples for gelability.5. Significance and Use5.1 This practice provides a means of preparing a number ofgel vehicle samples with minimum use of materials and time.It provides a means of quickly characterizing and comparingthe gelability or reactivity of resins, vehicle
12、s, and gellingagents.6. Apparatus6.1 Mercury Thermometer, capable of reading from 0 to250C and conforming to Specification E 1.6.2 Jars, (40 mm in diameter by 83 mm in height), 70 cm3with nonmetallic screw-on lids.6.3 Microwave Oven, common 750-watt.56.4 Microwave Oven Carousel, if not contained in
13、themicrowave oven.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.37 on Ink Vehicles.Current edition approved May 10, 2003. Published June 2003. Originallyapproved in 1991. La
14、st previous edition approved in 1997 as D 5166 - 97.2Annual Book of ASTM Standards, Vol 06.03.3Annual Book of ASTM Standards, Vol 06.02.4Annual Book of ASTM Standards, Vol 14.03.5Any common microwave oven, available at most appliance stores, can be used.A 750watt oven with a builtin turntable is pre
15、ferred. Ovens with lower power willrequire adjustments in the test cycle.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.5 Glass Dish, 15.2 cm in diameter.6.6 Balance or Scale, capable of weighing to 60.1 gaccuracy.6.7 Ink Knife or
16、 Rigid Spatula.6.8 Rheology Testing Apparatus, at the discretion of theuser.7. Reagents and Materials7.1 Nonvolatile materials including resins, alkyds, gellants,etc., consistent with those used in the manufacture of litho-graphic ink vehicles, for example, aromatic hydrocarbon res-ins, modified ros
17、in ester resins, long oil linseed isophthalicalkyds, and aluminum compounds.7.2 Solvents typically used in the manufacture of litho-graphic ink vehicles, for example, hydrocarbon petroleumdistillate with carbon numbers in the range of C12 to C16 andinitial boiling point above 150C.8. Procedure8.1 Pl
18、ace 45 g (or the calculated weight) of previouslyprepared pregel vehicle into each of five or more 30-cm3bottles.NOTE 1Any vehicle, even a very complex formulation, without thegellant added may be used as the pregel vehicle portion for the microwaveoven gelability process.8.1.1 In the absence of a v
19、ehicle formula agreed uponbetween user and seller, the following test vehicle formula issuggested:6,7PartsPregel VehicleResin 35Alkaline refined linseed oil (ARLO) 30C12-C16 hydrocarbon petroleum distillate 2590Gellant/Solvent Addition33.3 % oxyaluminum octoate/66.7 % C12-C16 hydrocarbonpetroleum di
20、stillate101008.2 Estimate the amount of gellant required to make anacceptable gel vehicle. Add gellant solution (between 30 and50 % gellant in major vehicle solvent recommended) in 1 %increments plus additional solvent to adjust the vehicle to a100 % formula. If the amount of gellant required can no
21、t beestimated, use a larger range of gellant concentration.8.2.1 If using the pregel formula as just recommended, therequired amount of gellant can be estimated from Table 1.8.2.2 A sample containing no (0 %) gellant solution isalways prepared as the standard for each resin.8.3 Mix the added liquids
22、 into the pregel very well using anink knife or rigid spatula.8.4 Place the five sample bottles, without tops, into the15.2-cm glass dish and place on the carousel in the microwaveoven.8.5 Turn on the carousel and ensure that it is turning beforestarting the heating cycle. Turn on the light in the o
23、ven toobserve the process.8.6 Set the timer on the oven for “5.00” min and start thecooking cycle.8.7 Upon completion of the cooking cycle, check thetemperature of the samples to determine whether a temperatureof 105 to 110C was obtained. If not, continue the heatingcycle in 1-min intervals until th
24、e samples have reached thistemperature.8.8 Remove the samples from the microwave oven, andallow to cool.8.9 Seal cooled samples with jar lids.NOTE 2If more than one set of samples is to be run, allow themicrowave oven to cool between runs. Heat is retained in the oven and ifa second set of samples i
25、s run immediately it will be subjected to moreheat than the first set.9. Evaluation9.1 Samples should be tested immediately after preparationand after 24 h to determine the effects of post gelation, if any.9.2 Guide D 154 outlines many methods applicable to thetesting of varnishes. It is an excellen
26、t guide for those lookingfor specific areas of evaluation.9.3 Lightly gelled resin solutions and vehicles can be testedfor changes in viscosity by using either Test Method D 1545 orD 1725. These test methods both use Gardner bubble tubes todetermine the viscosity of liquids.9.4 Another test method f
27、or testing gelled ink vehicles isTest Method D 4040. This method utilizes a falling-rod vis-cometer and can be used to determine the non-Newtoniannature of vehicles. Other viscometers used for determining therheology of gelled vehicles include variable shear rate viscom-eters and cone and plate visc
28、ometers.9.5 For the trained analyst the occurrence of gelation isevident and gels can be rated visually (for example, long,medium, medium short, short gel body).6This formula works best with higher molecular weight ink resins (for example,phenolic modified rosin esters). It is suggested that the res
29、in solids be increased forlow molecular weight resins (for example, simple rosin esters, modified hydrocar-bons, etc).7When a resin is insoluble, reformulate replacing 5 parts of C12-C16 hydrocar-bon petroleum distillate with TXIB (2,2,4-trimethyl-1,3-pentanediol, diisobutyrate)or TDA (tridecyl alco
30、hol). Caution: TDA may hinder the reactivity of the resinsystem tested.TABLE 1 Microwave Gelability Test, Weights and Concentrationsfor 50-g SamplesGellantSolution, %Actual GellantConcentration, %Weight GellantSolution, gA(at 33.3 %Gellant in Ink Oil)Weight Ink Oil, gA0 0.00 0.0 5.01 0.33 0.5 4.52 0
31、.67 1.0 4.03 1.00 1.5 3.54 1.33 2.0 3.05 1.67 2.5 2.56 2.00 3.0 2.07 2.33 3.5 1.58 2.67 4.0 1.09 3.00 4.5 0.510 3.33 5.0 0.0AWeight added to 45-g pregel sample.D 5166 97 (2003)210. Report10.1 Report the following information:10.1.1 Sample identification,10.1.2 Test run,10.1.3 Brief summary of proced
32、ure,10.1.4 Conditions of test procedure, and10.1.5 Results of the analyses made. In the case of fallingrod viscometer determinations, the following data could beobtained using Test Method D 4040 (see also the ApparatusSection of this test method):10.1.5.1 Apparent viscosity at 2500 at 25C, s,10.1.5.
33、2 Pseudo-Bingham Yield value at 25C,10.1.5.3 Shortness ratio (yield value/viscosity), and10.1.5.4 Slope (non-Newtonian parameter).NOTE 3For a measurement of relative resin, vehicle, or gellantreactivity, lots of rheology versus gellant concentration (see Fig. 1)provide an excellent comparison.NOTE 4
34、Falling rod viscosity slope (non-Newtonian parameter), short-ness ratio, and visual degree of shortness, if used properly, are all suitablemeasures of rheology.11. Keywords11.1 gel; gelability; gelled varnish; gelled vehicle; micro-wave oven; non-Newtonian fluid; pregel; pregel varnish; pregelvehicl
35、e; shortness ratio; slope; yield valueASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the r
36、iskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of t
37、his standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmak
38、e your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 1 Determination of Lithographic Ink Resin GelabilityD 5166 97 (2003)3
