6

-1

6

Adhesion Testing

6.1 Fundamentals of Adhesion

6-

1

6.2 Standardization of Adhesion Tests

6-

3

6.3 Delamination Procedures

6-

4

6.4 Local Debonding Systems

6-


In chemical terms, there is a considerable similarity between paints on one side and adhesives or glues
in this chapter to concentrate on the behavior of paint materials. Adhesion is the property requested in
either case, though perhaps with different emphasis on its intensity, according to the intended use.
Such a coating is, in essence, a polymer consisting of more or less cross-linked macromolecules and
a certain amount of pigments and fillers. Metals, woods, plastics, paper, leather, concrete, or masonry,
to name only the most important materials, can form the substrate for the coating.
It is important, however, to keep in mind that these substrate materials may inhibit a rigidity higher
than that of the coating. Under such conditions, fracture will occur within the coating, if the system
experiences external force of sufficient intensity. Cohesive failure will be the consequence, however, if the
adhesion at the interface surpasses the cohesion of the paint layer. Otherwise, adhesive failure is obtained,
indicating a definite separation between coating and substrate.

Ulrich Zorll

Forschungsinstitut für Pigmente and
Lacke

DK4036_book.fm Page 1 Monday, April 25, 2005 12:18 PM
© 2006 by Taylor & Francis Group, LLC
Components at the Interface • Causes of Failure • Measures of
Cross-Cut Test • Tensile Methods
Adhesion
Scratch Technique • Indentation Debonding • Impact Tests
Ultrasonic Pulse-Echo System • Acoustic Emission Analysis •
Knife-Cutting Method • Peel Test • Blister Method
Thermographic Detection of Defects
on the other (Figure 6.1). Both materials appear in the form of organic coatings; thus, it is appropriate

7


2
7.6

7.7 Calculations

7-

2

7.8 Converting to a 100 Gallon Formulation

7-

4
7.9 Cost

7-

4
7.10 Coverage

7-

5
7.11 Computer Use

7-

5

Consultant

DK4036_book.fm Page 1 Monday, April 25, 2005 12:18 PM
© 2006 by Taylor & Francis Group, LLC
Formulation Weight • Formulation Volume • Formulation
Density • Formulation of “Nonvolatile by Weight” •
Ratio (Weight) • Pigment Volume Content (Volume)
Conventions
7-2
Formulation “Nonvolatile by Volume” • Pigment to Binder

Coating Calculations

7

-3

TA B LE 7.1

Paint Formulation Calculations

No.

Constants

Calculations
Material lb/gal gal/lb %NV Cost, $/lb Weight Volume Dry Weight Dry Volume #/100 gal gal/100 gal Cost/gal

1Titanium Dioxide 34.99 0.029 100 $1.15 100 2.86 100 2.86 196.00 5.6 2.25
2 Phthalocyanine Blue 12.99 0.077 100 $10.55

© 2006 by Taylor & Francis Group, LLC

7

-6

Coatings Technology Handbook, Third Edition

TA B LE 7.2

Paint Formulation

Constants

Calculations
No.Material lb/gal gal/lb %NV
%
Solvent
%
Water
Cost,
$/lb Weight Gallons Dry Wt Dry Vol #/100 gal gal/100#
Cost/
100 gal Water Solvent

1 Gloss Varnish 8.43 0.118623962 1 0 0 $0.00 75 8.896797153 75.00 8.896797153 347.76 41.25 $0.00 0 0
2Resin @ 40% in BCarbAc 8.71 0.114810563 0.4 0.6 0 $0.00 25 2.870264064 10.00 1.148105626
115.92 13.31 $0.00 0 69.55284525
3Titanium Dioxide 10.5 0.095238095 1 0 0 $0.00 95 9.047619048 95.00 9.047619048
440.50 41.95 $0.00 0 0

% Water 0.00 VOC = 1.05 lbs/gal
% Solvent 11.18

DK4036_book.fm Page 6 Monday, April 25, 2005 12:18 PM
© 2006 by Taylor & Francis Group, LLC

8

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8

Infrared Spectroscopy

of Coatings

8.1 Introduction

8-

1
8.2 Principles

8-

1
8.3

8.4 Data Collection


1,2,3

and there are extensive collections of reference spectra available.
Almost all components of coatings can be identified by IR; it is especially useful for polymers. IR
spectroscopy can monitor changes, such as drying, curing, and degradation, which occur to coatings.
Quality control of raw materials and process monitoring during coating synthesis and formulation can
be done by IR spectroscopy.
Most important to the identification of coatings and the study of their properties is the skill of the
analytical scientist. This factor is often overlooked because the trend in analytical instrumentation in recent
years has been increasing computer control and automation. Even when these systems are at hand, they
have little value without a well-trained and experienced analytical scientist behind them. The individual
with a coatings problem or application is well advised to seek the services of an experienced spectroscopist.

8.2 Principles

The atoms of any molecule are continuously vibrating and rotating. The frequencies of these molecular
motions are of the same order of magnitude (10

13

to 10

14

cycles per second) as those of IR radiation.
When the frequency of molecular motion is the same as that of the IR radiation impinging on that

Douglas S. Kendall

National Enforcement

50. J. L. Gerlock, C. A. Smith, E. M. Nunez, V. A. Cooper, P. Liscombe, D. R. Cummings, and T. G.
Dusibiber, Adv. Chem. Ser., 249, 335 (1996).
51. A. A. Dias, H. Hartwig, and J. F. G. A. Jansen, Surf. Coat. Int., 83, 382 (2000).
52. R. J. Dick, K. J. Heater, V. D. McGinniss, W. F. McDonald, and R. E. Russell, J. Coat. Technol., 66,
23 (1994).
53. M. W. Urban, C. L. Allison, G. L. Johnson, and F. Di Stefano, Appl. Spectrosc., 53, 1520 (1999).
54. D. J. Skrovanek, J. Coat. Technol., 61, 31 (1989).
55. M. L. Mittleman, D. Johnson, and C. A. Wilke, Trends Polym. Sci., 2, 391 (1994).
56. M. Irigoyen, P. Bartolomeo, F. X. Perrin, E. Aragon, and J. L. Vernet, Polym. Degradation and
Stability, 74, 59 (2001).
57. H. Kim and M. W. Urban, Polymeric Mater. Sci. and Eng., 82, 404 (2000).
58. B. W. Johnson and R. McIntyre, Prog. Org. Coat., 27, 95 (1996).
59. M. R. Adams, K. Ha, J. Marchesi, J. Yang, and A. Garton, Adv. Chem. Ser., 236, 33 (1993).
60. L. J. Fina, Appl. Spectrosc. Rev, 29, 309 (1994).
61. T. Buffeteau, B. Besbat, and D. Eyquem, Vib. Spectrosc., 11, 29 (1996).
62. N. Dupuy, L. Duponchel, B. Amram, J. P. Huvenne, and P. Legrand, J. Chemom, 8, 333 (1994).
63. M. W. C. Wahls, E. Kentta, and J. C. Leyte, Appl. Spectrosc., 43, 214 (2000).
64. J. E. Dietz, B. J. Elliott, and N. A. Peppas, Macromolecules, 28, 5163 (1995).
65. T. A. Thorstenson, J. B. Huang, M. W. Urban, and K. Haubennestal, Prog. Org. Coat., 24, 341 (1994).
66. B. W. Ludwig and M. W. Urban, J. Coat. Technol., 68, 93 (1996).
67. E. Kientz and Y. Holl, Polym. Mater. Sci. Eng., 71, 152 (1994).
68. G. C. Pandey and A. Kumar, Polym. Test., 14, 309 (1995).
DK4036_book.fm Page 8 Monday, April 25, 2005 12:18 PM
© 2006 by Taylor & Francis Group, LLC

9

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9

3

9.1 Introduction

The evaluation of substances and finished materials by thermal analysis will be discussed as a tool that
the paint chemist can use to help evaluate coating properties. These properties are those that change as
a function of temperature.

9.2 Characteristics

Substances change in a characteristic manner as they are heated. Thermal analysis (TA) monitors these
changes. TA procedures are generally used to characterize various substances and materials that change
chemically or physically as they are heated. These changes in properties as a function of temperature
have been used to help characterize the interrelationship of a coating’s composition and performance.
TA methods or techniques measure changes in properties of materials as they are heated or at times cooled.
A TA evaluation entails subjecting a small sample of from a few milligrams to 100 mg to a programmed
change in temperature. The resulting change in property is detected, attenuated, plotted, and measured
by a recording device.
The instrumentation consists of an analysis module, a heating or cooling source, a measuring device,
and a system for reporting the results, usually as an

X

–

Y

plot. A computer is used to program and control
the procedure and analyze and store the results.