Verein Deutscher Druckingenieure e.V. VDD-Seminarreihe, Effektfarbmessung

Darmstadt 2008

Effektfarbmessung Quo vadis ?
Dr. Peter Gabel / GAL-Pigmente / Gernsheim
Merck KGaA - Pigments worldwide
Interference - Optical Principles
Color Travel by different Observation-Points
Interference = f ( n0, n1, d, sin ) n0,1 = refractive indice ( n0 < n1) d = thickness

n0 n1 d

metal oxide

substrate

G.Pfaff, P.Reynders, Angle-Dependent Optical Effects Deriving from Submicron Structures of Films and Pigments, Chem.Rev.1999,99,1063
Colorstream T20-04 WNT Lapis Sunlight TiO2 / SiO2 gold / silver / green / blue Colorstream F20-00 WNT Autumn Mystery Fe2O3 / SiO2 red / gold / bronze / green
Colorstream T20-01 WNT Viola Fantasy TiO2 / SiO2 lilac / silver / green / blue Colorstream T20-03 WNT Tropic Sunrise TiO2 / SiO2 green / silver / red / orange
ChromaFlair 190 Black Background
ZEISS GKM 311/ M MINOLTA CM 512m3 OPTRONIK Multi Flash X-RITE MA 68 II

-50 -20

Ti - Type

Fixed 45 illumination

45: as -30 45: as -10
10 b* a* 0 -20 -10 --10 -15 -20 -25

45: as +15

Measuring Geometry for Effect Pigments ASTM E2539-08

x 65 x x x x

Comparison Chart of Geometries Designations
Method Number Designation Illuminator Geometry Viewer Geometry Standard Classical metallic geometries (ASTM E 2194, DIN 6175-2)- 1st Generation Gonioapparent METHOD 1 Traditional CIE Convention Anormal Illuminators Anormal Viewing E 2175 45:-30 45:-20 45:0 45:30 45:65* METHOD 2** Aspecular angle (Single) Anormal Illuminator Aspecular Viewing E 45:as 15 45:as 25 45:as 45 45:as 75 45:as 110 METHOD 3 New Proposal Anormal Illuminators Aspecular Viewing P45:120 P45:110 P45:90 P45:60 P45:25* METHOD 4 New Proposal Protractor method Protractor Illuminators Protractor Viewing -
New interference geometries (under discussion)-2nd Generation Gonioapparent
15: 0 15:-30 45:-60 65*:-50

15 -15 -15 15

15:as 15 15:as -15 45:as -15 65:as 15
P75:90 P75:120 P45:150 P25*:140
* 65:as15 illumination is in conflict with 45:as110 viewing direction ** The notation for this method does not accommodate multiple illuminators/multiple viewers
New ASTM International Standard Covers Latest Wave of Gonioapparent Colorants
First generation gonioapparent colorants are materials pigmented with metal flakes that change lightness as illumination angles change. Used heavily in automotive coatings, the first generation of gonioapparent materials was covered by ASTM International standard E2194, Practice for Multiangle Color Measurement of Metal Flake Pigmented Materials, first published in 2003. Now, a second generation of gonioapparent colorants that change color with varying illumination and viewing angles has led to the development of a new standard, E2539, Practice for Multiangle Color Measurement of Interference Pigments. Both ASTM E2194 and E2539 are under the jurisdiction of Subcommittee E12.12 on Gonioapparent Color, part of ASTM International Committee E12 on Color and Appearance.
Multi-Angle Color Measurement and Flake Characterization
Multi-angle Color Measurement BYK-mac Illumination: 45 Detection: 6-angles -15, 15, 25, 45, 75, 110 Sparkle Characterization Direct illumination: 15,75,45 from perpendicular Camera detection: 0 Graininess Characterization Diffused illumination Camera detection: 0
G. Kiegle-Boeckler, ECS 2007 Nrnberg, Total Color Measurement of Effect Finishes
Visual Effect - Evaluation
Appearance of effect finishes depends on illumination conditions: Sunny sky: Direct illumination Color starts to sparkle
Cloudy sky: Diffused illumination Fine versus grainy pattern

Calculation of Sparkle and Graininess Values
Analysis of the histograms

14000 12000

997 Sparkle 15 Sparkle 45 Sparkle 75 Graininess

Lightness Grades

X-Rite MA xx
Nisper, J., American Coatings Conference, 2008

Literatur

M.R.F. Kuntz, F. Daumard, M. Rsler, A. Huber, G. Pfaff, A New Interference Color Space Concept for Coatings, CPMA Conference MAY 13 15, 2008, Lincolnshire, IL. A. Huber, M. Rsler, G. Pfaff, KAROSSERIELACKIERUNG 2020, 19. 20. November 2007, Bad Nauheim
TEANEY, S., PFAFF, G., NITTA, K., New Effect Pigments using Innovative Substrates, ECJ (1999) 4, 434
SHARROCK, S.R., SCHUEL, N., New Effect Pigments based on SiO2 and Al2O3 Flakes, ECJ (2000) 1-2, 105
M.Rsler, F.J. Maile: Local Gloss and Sparkle caused by Effect Pigments: Psychophysics, Measurements and Simulations
Color Styling for Rinse-off Products

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