1、Designation: D7733 12Standard Specification forAcrylic Dispersion Ground1This standard is issued under the fixed designation D7733; 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
2、indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard specifies test methods which measureminimum qualities for acrylic dispersion grounds.1.2 The values stated in SI units are to be regarded as th
3、estandard. 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 theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the ap
4、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1640 Test Methods for Drying, Curing, or Film Formationof Organic Coatings at Room TemperatureD3359 Test Methods for Measuring Adhesion by Tape Test3. Terminology3.1 Definitions:3.1.1 flash-through, nthe
5、visible evidence of oil on theopposite side of a support to which it was applied; also referredto as strike-through.3.1.2 gesso grounds, n:3.1.2.1 calcium hydroxide and water (“slaked lime”).3.1.2.2 calcium sulfate (“plaster of Paris”) or calcium car-bonate (chalk) prepared with a natural protein gl
6、ue water.3.1.2.3 in contemporary usage, the term “gesso” is some-times used by manufacturers of acrylic dispersion products todescribe their products in a brand name.3.1.3 ground, na surface onto which an artist appliesdecorative coatings and paints.3.1.4 polymer, na long chain synthetic or naturall
7、y occur-ring molecule composed of smaller, repeating units calledmonomers.3.1.5 size, na liquid material that absorbs and penetratesinto a substrate preparing the substrate for a primer or groundby at least partially sealing the surface and creating moreintegrity and less absorption of the surface.3
8、.1.6 strike-through, nsee flash-through.4. Significance and Use4.1 This specification establishes quality and performancerequirements and provides a basis for common understandingamong producers, distributors and users.4.2 It is not intended that all grounds meeting this require-ment be identical no
9、r have uniform excellence in all respects.Variation in manufacture not covered in this specification maycause some artists to prefer one brand to another, either ofwhich may be acceptable by this specification.5. Labeling Requirements5.1 Acrylic dispersion products conforming to this standardwill in
10、clude acrylic, polymer, dispersion polymer, or acrylicdispersion in their description to differentiate them fromtraditional gessoes.6. Quality Assurance6.1 Conditions not covered in this specification that affectthe quality of acrylic dispersion grounds:6.1.1 SubstrateFactors such as the texture, gl
11、oss, effectivepH, porosity, chemical composition and condition of thesubstrate will affect gloss, gloss uniformity, drying time,adhesion and the flexibility of the dried ground.6.1.2 Environmental ConditionsFactors such as tempera-ture, humidity, airflow and light conditions affect applicationproper
12、ties, film formation, drying time and adhesion.6.1.3 StorageFactors such as aging and high and lowtemperatures may cause changes in consistency.6.2 Wet Ground Properties:6.2.1 Viscosity/ConsistencyGrounds shall be smooth andconsistent except for functional particles that provide tooth.Paste type gro
13、unds may not flow or level; ready to brushgrounds will flow evenly.6.2.2 pHThe pH shall be 7.0 to 10.0.6.2.3 Fineness of Dispersion (Grind)Grind will vary andmay contain coarse particles for adhesion, promoting thefunctional tooth of the dry ground.1This specification is under the jurisdiction of AS
14、TM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.57 on Artist Paints and Related Materials.Current edition approved Feb. 1, 2012. Published March 2012. DOI: 10.1520/D773312.2For referenced ASTM standards, visit the ASTM we
15、bsite, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United St
16、ates.6.2.4 Freeze-Thaw StabilityUsing a freezer that has atemperature of -7C (20F) or lower, subject the ground to fivefreeze thaw cycles. A freeze thaw cycle shall consist offreezing the ground to a solid state (minimum 18 h) and thenthawing the ground (minimum of 5 h) to room temperature,22 6 2C (
17、72 6 5F). The ground shall then meet therequirements of 6.2, 6.3, 6.4.6.2.5 DryingUse a 6 mil film applicator (drawdown bar)to make a uniform drawdown on a lacquer sealed card or panel.At a relative humidity of 50 to 75 % and at a temperature of 18to 27C (65 to 80F) the dust free drying time determi
18、ned inaccordance with Test Methods D1640 shall be not less than 10min.6.3 Dry Properties:6.3.1 Adhesion by Test Methods D3359Measuring Adhe-sion by Tape Test.6.3.2 Painting Media on the GroundTesting adhesion ofartist acrylic and oil paints, and each type of painting media, tothe ground shall achiev
19、e a classification of 5B when tested inaccordance with Test Methods D3359.6.3.3 Ground on SubstrateTesting adhesion of theground/substrate interface shall achieve a classification of 5Bwhen tested in accordance with Test Methods D3359.6.4 Oil Hold Out by Described Method:6.4.1 Scope:6.4.1.1 This tes
20、t method is to determine oil absorption andpenetration into an acrylic dispersion ground. The procedure isqualitative and the test will result in a pass/fail determination.6.4.2 Significance and Use:6.4.2.1 The oxidation of drying oils used in artists mediacontributes to the embrittlement and degrad
21、ation of naturalfibered substrates. One attribute of the acrylic dispersionground is to prevent the penetration of oil into the substratewhile also providing adequate absorbency to promote adhesionof the oil media.6.4.3 Apparatus:6.4.3.1 Eye-dropper.6.4.4 Reagents and Materials:6.4.4.1 Unless otherw
22、ise indicated, references to oil shall beunderstood to mean raw alkali-refined linseed oil.6.4.5 Procedure:6.4.5.1 Test substrates shall be untreated stretched #10cotton duck canvas on stretcher bars that allow for open backaccess to the canvas. Prepare the stretched canvas by evenbrush application
23、of the ground. Create a matrix of layers thatallow a 15 by 15 cm (6 by 6 in.) test area of single, double andtriple coats of the ground. Each coat shall dry for a minimumof 24 h before application of the subsequent coat.6.4.5.2 Apply three drops of raw alkali-refined linseed oilvia eyedropper to the
24、 center of each of the 15 by 15 cm (6 by6 in.) test areas. Each drop shall be .025 6 .00125 ml, withtotal volume for the three drops equaling .075 6 .00375 ml.The eyedropper can be any type, available in any pharmacy.6.4.5.3 Oil PenetrationSix week after the oil has beenapplied, observe the oil drop
25、s. For penetration, observe theback side of the canvas. There must be no evidence of the oilflashing through the three-coat section.6.4.5.4 Oil AbsorptionSix weeks after the oil has beenapplied, observe the front side of the canvas. The oil dropsmust not be dried as a bead on the surface: there shou
26、ld besome absorption of the oil into the surface, leaving the surfaceslightly glossier than the ground and having some visualevidence of the oil still remaining on the surface. The oil shallnot have wicked or bled more than five times the originaldrops area (5 to 7 cm).6.4.6 Report:6.4.6.1 Report th
27、e following information:6.4.6.2 The evidence or lack of evidence of flash-through.6.4.6.3 The evidence or lack of evidence of the oil drophaving dried as a bead on the surface.6.4.6.4 The evidence or lack of evidence of oil spreadwithin or beyond the proscribed area.6.4.7 Precision and Bias:6.4.7.1
28、No information is presented about either the preci-sion or bias for measuring oil hold out by described methodsince the test results are nonquantiative.6.5 Flexibility by Described Method:6.5.1 Scope:6.5.1.1 This test method is to determine adequate flexibilityand resistance to cracking of the acryl
29、ic dispersion ground oncanvas. The procedure is qualitative and the test will result ina pass/fail determination.6.5.2 Significance and Use:6.5.2.1 Canvas coated with acrylic dispersion grounds areexpected to resist cracking when placed under stress and strainduring preparation, storage, and handlin
30、g.6.5.3 Procedure:6.5.3.1 Test substrates shall be untreated stretched #10cotton duck canvas on stretcher bars that allow for open backaccess to the canvas. The cotton duck may not be sized afterstretching. Prepare the stretched canvas by even brush appli-cation of two coats of the ground allowing a
31、dequate dryingtime between coats.6.5.3.2 After the canvas has dried for a minimum of twoweeks, carefully remove the canvas from the stretcher bars.Allow the canvas to acclimate for a minimum of1hinanenvironment of 20 to 22.2C (68 to 72F) and 25 to 35 % RH,carefully take the acclimated canvas and ben
32、d it over a sharp90-degree corner. Repeat this test ten times, using a new areaof the prepared canvas and being careful not to handle the areasof the canvas intended to be bent for testing. There shall be nocracking of the ground in all ten attempts.6.5.4 Report:6.5.4.1 Report the following informat
33、ion:6.5.4.2 The evidence or lack of evidence of cracking of theground.6.5.5 Precision and Bias:6.5.5.1 No information is presented about either the preci-sion or bias for measuring flexibility by described method sincethe test results are nonquantitative.7. Keywords7.1 acrylic; dispersion polymer; g
34、esso; ground; oil hold out;polymer; primerD7733 122ASTM 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 righ
35、ts, and the riskof 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
36、revision of this 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
37、you shouldmake 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7733 123
