Table Of ContentNONPOLLUTING COATINGS
AND COATING PROCESSES
NONPOLLUTING COATINGS
AND COATING PROCESSES
Proceedings of an ACS Symposium held
August 30-31 , 1972, in New York City
Edited by
J. L. Gardon
M & T Chemicals Inc.
Rahway, New Jersey
and
Joseph W. Prane
Consultant
Elkins Park, Pennsylvania
PLENUM PRESS - NEWYORK- LONDON -1973
Library of Congress Catalog Card Number 72-97719
ISBN-13: 978-1-4684-0738-9 e-ISBN-13: 978-1-4684-0736-5
DOl: 10.1007/978-1-4684-0736-5
© 1973 Plenum Press, New York
Softcover reprint of the hardcover 1s t edition 1973
A Division of Plenum Publishing Corporation
227 West 17th Street, New York, N.Y. 10011
United Kingdom edition published by Plenum Press, London
A Division of Plenum Publishing Company, Ltd.
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All rights reserved
No part of this publication may be reproduced in any form
without written permission from the publisher
PREFACE
Ecological requirements are forcing a change in tech
nology of industrially applied coatings. At present sol
vent-borne coatings dominate this field but in the next
few years rapidly increasing use will be made of aqueous
coatings, electrocoating, solvent-free liquid coatings which
can be cured by U. V.-light or electronbeam, and powder
coatings. This monograph describes some recent developments
in these new "non-polluting" coating technologies.
It is impossible to predict how big a share each of
these novel coatings will take from the conventional in
dustrial finishes market which at present represents an
annual volume of about one billion dollars. In all likeli
hood each will find its own specialized use. We hope that
this monograph will help the reader to form a perspective
of the various novel coatings, their method of application,
their advantages and their limitations.
J. L. Gardon Joseph W. Prane
Rahway, N. J.,and Elkins Park, Pa.
October 15, 1972
v
CONTENTS
Status of Air Pollution Control Regulations........... 1
Francis Scofield
Physical Characterization of Water Dispersed and
Soluble Acrylic Polymers........................... 5
William H. Brendley, Jr. and Thomas H. Haag
Methylated Urea Formaldehyde Cross-Linking Agents
in Aqueous Emulsions............................... 25
Leonard J. Calbo
Polymer Parameters Affecting Aqueous Topcoat
Systems. • . . . . . . . . . • . . . . . . • . . . . . . . . . • . • . . . . • . . . . . . . . 35
Robert A. Ottaviani
Performance Characteristics of a Fast Curing
Acrylic Resin in Electrocoating Paints............. 45
Girish G. Parekh
Electrodeposition Systems: Composition, Char-
acteristics, Performance and Maintenance........... 57
Peter J. Palackdharry
Ultrafiltration of Electrocoating Systems............. 69
Arnold J. Josefson and Loren R. Munson
Quantitative Prediction of Recycling Efficiency
of Electrocoating Paint Solids Through
Ul trafil trate Rinse................................ 83
George E. F. Brewer
Gas Chromatographic Determination of Amine Sol
ubilizers and Hydroxyl-Containing Solvents in
Electrocoat Systems................................ 93
Eldrige I. White and Harold D. Swafford
vii
viii CONTENTS
The Ultraviolet Curing of Coatings.................. 109
S. H. Schroeter
The Ultraviolet Cure of Solventless Resins--A
Pollution Free Method?......................... 135
S. H. Schroeter and J. E. Moore
Some Fundamental Aspects of the Polymerization
of Vinyl Monomers with Electron Beams........... 149
E. P. Stahel, C. C. Allen, D. R. Squire,
and V. Stannett
The Present Status of Electron Beam Curing of
Coa tings. . . • . . . . . . • . • . . . . . . • . . . . . • . . . . . . . . . . . • • • 169
Kennard H. Morganstern
Electron Beam Processor Technology.................. 179
S. V. Nablo, J. R. Uglum and B. S. Quintal
Electron Beam Curing - A Non-Polluting System....... 195
Carl R. Hoffman
Production Systems for Electrostatic Spray
Application of Powder Coatings..... ..... .•.. .... 207
Hani T. Azzam
Electrostatic Powder Coating - Potentially A
Pollution Free Finishing Method................. 225
Emery P. Miller
Measurement of Opacity and Coverage in Thin-Film
Powder Coatings................................. 235
Douglas S. Richart and Kenneth W. Gray
Flow at the Interfaces of Powder Coatings........... 251
S. M. Wolpert and J. J. Wojtkowiak
Index. . . • . . . . . . . . . . . . . . . • . . . . . . • . . . • . . • . . . . . . . . . . . • 271
STATUS OF AIR POLLUTION CONTROL REGULATIONS
Francis Scofield
National Paint and Coatings Association
1500 Rhode Island Avenue, NW
Washington, DC 20005
On the 30th of December 1970, the President signed the Clean ,Air
Act of 1970 which constitutes the basis of air pollution control
regulations as they are being developed. This provided that the
Environmental Protection Agency (EPA) should issue national
ambient air standards, which was done on April 30, 1971. These
provided nationwide standards for porticulate matter, sulfur
dioxide, carbon monoxide, oxides of nitrogen, hydrocarbons, and
photochemical oxidants. The last two arising from coatings solvents
are the two of concern to the coatings industry.
The Clean Air Act of 1970 required that states produce implementa
tion plans by which the national ambient air standards would be
achieved by 1975. These standards were submitted as of January 31,
1972, and on ~y 31 the EPA either accepted them or rejected the
plans in part, with suggestions as to changes which would be neces
sary to achieve the ambient air standards by 1975.
Some 16 states had concentrations of hydrocarbons or photochemical
oxidants exceeding the national standards. Of these, ten produced
implementation plans including regulations which might be expected
to achieve the standards in the prescribed time. Five states and the
District of Columbia either did not produce standards satisfactory to
EPA or ornitted some essential requirement.
The District of Columbia, with little or no industry, could only
reduce hydrocarbons and photochemical oxidants by traffic control
regulations and will not be discussed further.
2 FRANCIS SCOFIELD
Indiana, Tennessee, and Louisiana have moved to adopt regulations
satisfactory to the EPA. Texas believes that they can meet the
requ irements by controls on the storage and hand Ii ng of hydrocarbons
and has not attempted to control organic solvent emissions.
California with some 12 air pollution control districts, each with its
own regulations, has a number of minor discrepancies which EPA felt
should be corrected. This is under discussion.
At the present time it can be said that those states which have
regu lations control I ing the emission of organ ic solvents had in general
followed the framework of Rule 66, which was adopted by Los Angeles
County in 1966. However, none of the proposed regulations follows
Rule 66 exactly. There are small and sometimes significant differences.
It is therefore important that the individual state regulations be
examined with care since no two are exactly alike.
As a further complication, the Air Quality Act of 1970 did not pro
vide for federal "pre-emption." That is, any state or smaller
jurisdiction might adopt their own regulations if they were more
stringent than the federal requirements.
New York City and Philadelphia have adopted regulations which
resemble Rule 66, but have some aspects which are different and more
stringent. Meanwhile, some other states even though not required
by the Air Quality Act are in the process of adopting regulations
covering organic solvent emissions. Notably, New York State has
recently adopted Part 205 which is applicable to the New York
metropolitan area. It is probable that this will supersede New York
City's Local Law No. 49, but this has not yet happened.
In general, it should be remembered that the controls of these regula
tions are genera Ily addressed to the users of coatings rather than the
manufacturer. The manufacturer of organic coatings can in general
be conducted with little or no emission of solvents into the atmosphere
but the appl ication and curing of these coatings on fin ished products
be they factory applied, as automobiles, furniture, etc., or field
applied, as residences, bridges, highways, etc., require the evap
oration of large amounts of solvent and therefore fa II under these
regu lations.
So far no state has undertaken to control the evaporation of water,
and therefore water-thinned coatings tend to be exempt from these
regu lations. However, very few water-th inned coatings are com
pletely devoid of organic solvents. Los .Angeles and several of the
states have exempted water-thinned coatings which contain less than
STATUS OF AIR POlLUTION CONTROl REGULATIONS 3
twenty per cent volatile material. Neither of these exemptions apply
to all states, and the state regulation should be examined carefully
to make sure what exemptions are permitted.
Finally, it should be borne in mind that this is a statement of the
current situation. Many states are still in the process of developing
new regulations or revising old ones and the situation may be expected
to change, in general, for the worse with the passage of time.
PHYSICAL CHARACTERIZATION OF WATER DISPERSED AND SOLUBLE
ACRYLIC POLYMERS
William H. Brendley, Jr.
Thomas H. Haag
Rohm and Haas Company, Research Laboratories
Norristown and McKean Roads
Spring House, Pennsylvania 19477
INTRODUCTION
The increasingly restrictive anti-pollution legislation
which regulates the amount of organic solvent that can be
emitted into the atmosphere has generated renewed interest in
water-based polymers for general purpose industrial coatings.
More specifically, interest in aqueous acrylic polymers is
high because of their inherent durability, proven exposure
history, and good chemical resistance. This durability char-
acteristic is a reflection of the fact that acrylic polymers,
derived from acrylate and/or methacrylate esters, are trans
parent to natural sunlight and, as such, do not absorb ultra
violet radiation within these wavelengths. Their durability
is well attested to by the fact that all U.S. cars are coated
with either thermoplastic or thermosetting acrylic finishes.
The good chemical resistance is confirmed by the usage of the
acrylics as appliance finishes.
TYPES OF AQUEOUS ACRYLIC POLYMERS
There is a tendency to associate the word aqueous with
emulsion; however, aqueous acrylic polymers can be subdivided
into three specific types. These three types vary signifi
cantly in physical and mechanical properties and allow the
5
Description:Ecological requirements are forcing a change in tech nology of industrially applied coatings. At present sol vent-borne coatings dominate this field but in the next few years rapidly increasing use will be made of aqueous coatings, electrocoating, solvent-free liquid coatings which can be cured
