ASTM_D_6605_-_06_2020.pdf

Designation:D660506(Reapproved 2020)Standard Practice forDetermining the Color Stability of Hydrocarbon Resins AfterHeating1This standard is issued under the fixed designation D6605;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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 covers determination of the color stabilityof a hydrocarbon resin by exposure to a specific temperaturefor a defined time period in a forced-draft oven.1.2 Color stability is measured by the change in color of thetest resin,measured via the yellowness index color scale,inaccordance with Practice E313,or the procedure for GardnerColor,Test Method D6166.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D6166 Test Method for Color of Pine Chemicals and Re-lated Products(Instrumental Determination of GardnerColor)D6440 Terminology Relating to Hydrocarbon ResinsE313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color Coordinates3.Terminology3.1 Definitions:3.1.1 For definitions of terms relating to hydrocarbon resins,see Terminology D6440.4.Summary of Practice4.1 Specimens of the hydrocarbon resin(s)to be tested areplaced in 250-mL(8-oz)glass jars,which are placed in aheating block that is in a ventilated oven set at 175C.Thesamples are kept in the oven for an agreed upon period.At theend of this time,the samples are removed and allowed to cool.After cooling,the samples are dissolved in toluene.The colorof each aged resin solution is measured and compared to thatof a solution of the corresponding unaged resin.This colorincrease is a measure of the(lack of)stability of the resin.5.Significance and Use5.1 This practice is useful for both quality control andresearch.6.Apparatus and Materials6.1 Forced Draft Oven,with the ventilation set at maximumcapacity.6.2 Aluminum Block,equipped with a control thermocouple(see Fig.1).6.3 Temperature Indicator.6.4 Glass Jars,250 mL(8 oz),with suitably lined screwcap.NOTE1TFE-fluorocarbon-lined caps work well.6.5 Balance,readable to at least 0.1g.6.6 Shaker,used to facilitate the dissolution of the resinspecimens.6.7 Spectrophotometer or Tristimulus Colorimeter.7.Reagents7.1 Reagent Grade Toluene,or other agreed-upon solvent(for example,xylene),for dissolving resins.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.34 on Pine Chemicals and Hydrocarbon Resins.Current edition approved June 1,2020.Published July 2020.Originally approvedin 2000.Last previous edition approved in 2015 as D6605 06(2015).DOI:10.1520/D6605-06R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.8.Procedure8.1 Weigh 10.0 6 0.1 g of resin into each specimen jar.8.2 Tap each jar gently to flatten the resin layer.NOTE2Avoid having resin stick to the wall of the jar,since this tendsto bias the results high.8.3 Install the aluminum block(see Fig.1)in the center ofan electronically regulated oven with the ventilation set atmaximum.8.4 Set the oven controls so that the control thermocouplereads 175.0C 6 0.5C.8.5 WarningAn increase or decrease in the oven tem-perature from the specified temperature may alter the results.NOTE3It generally takes about 4 h to stabilize the aluminum block at175C,when starting from room temperature.8.6 Place the uncapped jar(s)containing the resin(s)to betested in the holes in the 175C aluminum block in the ovenand allow it to re