1、Designation: D 5166 97 (Reapproved 2008)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 () 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.1.2
3、 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 The values stated
4、in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does 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 he
5、alth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 154 Guide for Testing VarnishesD 1545 Test Method for Viscosity of Transparent Liquidsby Bubble Time MethodD 1725 Test Method for Viscosity of Resin SolutionsD 4040 Tes
6、t Method for Rheological Properties of PastePrinting and Vehicles by the Falling-Rod ViscometerE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 gel, nAny resin solution, or more complex blend ofresins and alkyds that has bee
7、n cooked or reacted with a gellingor cross-linking agent to build molecular weight and thatexhibits a pseudoplastic rheology. (Also called “gelled ve-hicle.”)3.1.2 gelling agent, nin the context of ink resins andvehicles, gelling agents or gellants are typically organo-aluminum compounds that react
8、with carboxylic acid andhydroxyl groups present on the backbone of resins and alkydsto form cross-linked networks. (Also called “gellant.”)3.1.3 gel length, nReferences to long, medium, and shortgel length refer to the length of a string of gelled vehicleobserved when pulling apart a small sample of
9、 vehicle with aspatula (that is, a long gel is very fluid and forms a “long”filament; a short gel has little flow and forms a “short”filament).3.1.4 pregel, nThe resin solution or vehicle componentscomprising the vehicle prior to the addition of gelling agentand viscosity adjusting solvent. (Also ca
10、lled “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 various levels of gellant are added. Alternately, variousgellants can be added at a given concentration to compare theireffectiveness.4.3 Pla
11、ce 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 waiting period, test and ratesamples for gelability.5. Significance and Use5.1 This practice provides a means of preparing a number ofgel
12、vehicle samples with minimum use of materials and time.It provides a means of quickly characterizing and comparingthe gelability or reactivity of resins, vehicles, and gellingagents.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applicatio
13、ns and is the direct responsibility ofSubcommittee D01.37 on Ink Vehicles.Current edition approved June 1, 2008. Published June 2008. Originallyapproved in 1991. Last previous edition approved in 2003 as D 5166 97 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
14、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Mercury T
15、hermometer, capable of reading from 0 to250C and conforming to Specification E1.6.2 Jars, (40 mm in diameter by 83 mm in height), 70 cm3with nonmetallic screw-on lids.6.3 Microwave Oven, common 750-watt.36.4 Microwave Oven Carousel, if not contained in themicrowave oven.6.5 Glass Dish, 15.2 cm in di
16、ameter.6.6 Balance or Scale, capable of weighing to 60.1 gaccuracy.6.7 Ink Knife or 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
17、litho-graphic ink vehicles, for example, aromatic hydrocarbon res-ins, modified rosin 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 number
18、s in the range of C12 to C16 andinitial boiling point above 150C.8. Procedure8.1 Place 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 v
19、ehicle portion for the microwaveoven gelability process.8.1.1 In the absence of a vehicle formula agreed uponbetween user and seller, the following test vehicle formula issuggested:4,5PartsPregel VehicleResin 35Alkaline refined linseed oil (ARLO) 30C12-C16 hydrocarbon petroleum distillate 2590Gellan
20、t/Solvent Addition33.3 % oxyaluminum octoate/66.7 % C12-C16 hydrocarbonpetroleum distillate101008.2 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 solven
21、t to adjust the vehicle to a100 % formula. If the amount of gellant required can not 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
22、solution isalways prepared as the standard for each resin.8.3 Mix the added liquids 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 ens
23、ure that it is turning beforestarting the heating cycle. Turn on the light in the oven 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
24、to 110C was obtained. If not, continue the heatingcycle in 1-min intervals until the 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
25、 to cool between runs. Heat is retained in the oven and ifa second set of samples is 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
26、 154 outlines many methods applicable to thetesting of varnishes. It is an excellent 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
27、Gardner bubble tubes todetermine the viscosity of liquids.3Any common microwave oven, available at most appliance stores, can be used.A750watt oven with a builtin turntable is preferred. Ovens with lower power willrequire adjustments in the test cycle.4This formula works best with higher molecular w
28、eight ink resins (for example,phenolic modified rosin esters). It is suggested that the resin solids be increased forlow molecular weight resins (for example, simple rosin esters, modified hydrocar-bons, etc).5When a resin is insoluble, reformulate replacing 5 parts of C12-C16 hydrocar-bon petroleum
29、 distillate with TXIB (2,2,4-trimethyl-1,3-pentanediol, diisobutyrate)or TDA (tridecyl alcohol). Caution: TDA may hinder the reactivity of the resinsystem tested.TABLE 1 Microwave Gelability Test, Weights and Concentrationsfor 50-g SamplesGellantSolution, %Actual GellantConcentration, %Weight Gellan
30、tSolution, gA(at 33.3 %Gellant in Ink Oil)Weight Ink Oil, gA0 0.00 0.0 5.01 0.33 0.5 4.52 0.67 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 (2008)29.4 Another test method for test
31、ing 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 viscometers
32、.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).10. Report10.1 Report the following information:10.1.1 Sample identification,10.1.2 Test run,10.1.3 Brief summary of procedure,10.1.4 Conditions o
33、f 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,10.1.5.2 Pseudo-Bingham Yield
34、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 4Falling rod viscosity s
35、lope (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; pregelvehicle; shortness ratio; slo
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37、uch 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 this standard or for add
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39、he 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 (2008)3
