1、Designation:D730607(Reapproved 2017)Standard Practice forTesting Low Temperature Film-Formation of Latex Paints byVisual Observation1This standard is issued under the fixed designation D7306;the number immediately following the designation indicates the year oforiginal adoption or,in the case of rev
2、ision,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 specifies a laboratory procedure for evalu-ating the ability of a latex paint to form a uni
3、form film free ofvisible defects at low temperatures.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibil
4、ity 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.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in th
5、e 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:2D823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Rel
6、ated Products on Test PanelsD3793 Test Method for Low-Temperature Coalescence ofLatex Paint Films by Porosity Measurement(Withdrawn2012)33.Terminology3.1 Definitions:3.1.1 low temperature coalescence(LTC),nthe ability ofa latex paint to form a film at low temperatures,typically4 6 2C(39 6 4F).4.Summ
7、ary of Practice4.1 The paint,applicator and the test panel are allowed toequilibrate for at least 4 h at 4 6 2C(39 6 4F).The test paintis applied to a part-sealed/part-unsealed drawdown chart andimmediately placed in a cold cabinet.4.2 After 18 h the panel is removed from the cold cabinetand evaluat
8、ed for any cracking of the paint film.NOTE1Temperature of film formation testing may be altered uponmutual consent of all parties involved.5.Significance and Use5.1 This practice can be used by paint formulators todetermine if a given paint has the ability to form a film at lowtemperatures.This prac
9、tice can be used as an aid for determin-ing coalescing solvent level required to form a good film.TestMethod D3793 compares the porosity of a film drawn down atroom temperature to another film drawn down and cured at lowtemperature.5.2 This practice provides no absolute information,ratherranking onl
10、y of the selected series of paints.5.3 This practice can provide a pass-fail situation if knownacceptable and unacceptable paints are included in the test.6.Apparatus and Materials6.1 Vacuum Plate.6.2 Paint Test Chart with sealed and unsealed evaluationareas.46.3 Paint Applicator(s),typically to app
11、ly 3 and 10 mil wetfilm thickness of paint with higher thickness being moresevere.6.4 Cold Cabinet,maintaining 4 6 2C(39 6 4F)or adifferent temperature as agreed upon.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the dir
12、ect responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition approved June 1,2017.Published June 2017.Originallyapproved in 2007.Last previous edition approved in 2013 as D7306 07(2013).DOI:10.1520/D7306-07R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,o
13、rcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Paint test charts selected for use should be from
14、 a sole supply across theexperiment to ensure accurate comparisons between test samples.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 st
15、andardization 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.1 6.5 Instrument,to record relative humidity(typically 20 to100%).NOTE2Variation in humidi
16、ty can have impact on film formation.6.6 4X 12X Magnifying Glass,6.7 Test Paint.7.Procedure7.1 Place the applicator,paint,and test panel in a coldcabinet and equilibrate for 4 h at 4 6 2C(39 6 4F),or asagreed upon.7.2 Secure a paint test chart with sealed and un-sealed areason a vacuum drawdown plate.7.3 After mixing the paint sample,draw down the paintuniformly using a straight bar applicator as in Practices D823.7.4 Immediately place the panel into the cold cabinet.7.5 After 18 h,remove the pa
