Table Of ContentFluorinated
Coatings and Finishes
Handbook
The Definitive User's Guide and Databook
Laurence W. McKeen
Copyright©2006 byWilliam Andrew, Inc.
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Plastics Design Library and its logo are trademarks of William Andrew, Inc.
ISBN: 978-0-8155-1522-7
Library of Congress Cataloging-in-Publication Data
McKeen, LaurenceW.
Fluorinated coatings and finishes handbook: the definitive user's guide and
databook/ LaurenceW. McKeen.
p.cm.
Includes bibliographical references and index.
ISBN-13: 978-0-8155-1522-7 (978-0-8155)
ISBN-10: 0-8155-1522-7 (0-8155)
1. Plastic coatings-Handbooks, manuals, etc. 2.
Fluoropolymers-Handbooks, manuals, etc. I. Title.
TP1175.S6M452006
668.4'22-dc22
2005033634
Printed in the United States of America
This book is printed on acid-free paper.
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health standards.
Dedicated tomymother (Helene) and father (Veikko)
WilliamAndrewPublishing
SinaEbnesajjad,Editorin Chief(ExternalScientificAdvisor)
PDL Fluorocarbon Series Editor's Preface
The original idea for the Fluorocarbon Series The first two books ofthe series cover com
was conceivedinthe mid 1990s. Twoimportantra mercialfluoropolymers (ethylenic);thethirdbookis
tionalesrequiredthe developmentofthe collection. focused on their applications in the chemical pro
First, therewereno definitive sources forthe study cessingindustries.Thefourthbookcoversfluoroelas
offluorinatedpolymers,particularlythe commercial tomers, the fifth fluorinated coatings and finishes,
products. A researcher seeking the properties and andthesixthbookisaboutfluorinatedionomers, such
characteristicsoffluorinatedplastics didnot havea as Nafion'", The seventh handbook represents an
single source to use as a reference. Information extensionofthe scope ofthe seriestonon-polymeric
available from commercialmanufacturers ofpoly materials. It addresses the preparation, properties,
mers had long been the source ofchoice. Second, and uses of fluorinated chemicals as refrigerants,
waves of the post-war generation (a.k.a., Baby fire extinguishers, blowing agents, and cleaning
Boomers)were beginningtoretire,thus erodingthe gases. All ofthe titles in the PDL Fluorocarbon
available knowledge base in the industry and Series appear in the back ofthis book in the PDL
academia. Librarylist.
The scopeofthe serieshas beenexpandedover The authors ofthehandbooksareleaders intheir
timetoincorporateotherimportantfluorinatedma fields who have devoted their professional careers
terials. Selectionofthetopicsofthebookshasbeen to acquiring expertise. Each book is a product of
based on the importance ofpractical applications. decades of each author's experience and research
Inevitably,anumberoffluorinatedcompounds,im into the available body ofknowledge. Ourhope is
portantin theirown right, have beenleft out ofthe that these efforts will meet the needs ofthe people
series. In each case, the size of its audience has whoworkwithfluorinatedpolymersandchemicals.
been found simplytoo smallto meetthe economic Future revisions are planned to keep this series
hurdles ofpublishing. abreast ofprogress in the field.
SinaEbnesajjad April 2006
Preface
Paintsandcoatingsaremuchmorecomplexthan Abetterunderstandingwill alsoleadtobettercom
initiallymeetstheeye.Myfirstintroductiontopaint munication between the coaters and coatings sup
chemistrycameasIwasjobhuntinginmyfinalyear pliers, which can shorten product and process de
ofgraduateschool attheUniversityofWisconsin. I velopmenttime.
was trainedthere as atheoretical and experimental Most ofthe chapters have very few references
analyticalchemist, atthe time specializinginhigh becausewhatIhave includediswhatIhavelearned
resolution mass spectroscopy. DuPont called and duringtwenty-fiveyearsdeveloping,formulating,and
offered an interview at their technical center of studyingfluoropolymercoatings around the world.
painttechnology, MarshallLaboratoryinPhiladel There are lots ofpotential references in the public
phia, Pennsylvania. They told me it was their pre literature,but Ididnot use them. In sections where
mier paint and coating development laboratory. I I discuss some specific products or product lines,
rememberthinking,"paint...how boring," andIal the informationreflects what was consideredup to
most did not accept the offer to interview. Fortu date at the time of publication. Product lines are
nately,Igaveitachanceandlearnedhowtrulycom continuallymodified,added,andeliminated.
plex these paintmixtureswere. Interactions among The firstchapterintroducesthefluoropolymers
allthe components complicatethe systems beyond that have been used or could be used in coatings.
theoretical modeling and analysis in most cases. I The structures are given and the basic properties
also learned that there were uses or functions of aresummarized. Chapter2provides backgroundon
paints andcoatingsbeyondappearance andrustpro how fluoropolymers are made and finished, and I
tection, andthatthere were dozens ofwaystoapply have attempted to presentthe chemistry as simply
the coatings. and clearly aspossible.
WhileinterviewingforajobintheMarshallLab's Chapter3is anintroductiontopaintor coating
analytical chemistrysection,Ilearnedhow complex formulation. Itintroducesthe next four chapters of
the analytical chemistry ofpaints was due to the this text, whichdiscuss the components oringredi
complexmixtures formedinthem. Partofmyinitial entsofpaintsandcoatings.Chapter4discussesbind
assignmentwasfocusedondevelopingways ofana ers, the non-fluoropolymers that are often used in
1yzingunknownliquid and solid paintsamples, in fluorocoatings. Itdiscusses the structures andprop
cludingcompetitiveproductanalysis.Thisworkwas ertiesofthesematerials. Thequestion,"Howdoyou
enjoyable and interesting. One would be surprised get anon-stickcoating to stick tothe substrate?"is
atwhat can be learned from apaintchip. Within a also answered. Chapter 5 deals with pigments and
couple years, Iexpressedaninterestinthe formula fillers.Thedispersionprocessesusedtopreparethem
tion ofpaints. DuPontreassignedmetotheTeflon'" for use in coatings is summarized. Chapter 6 com
finishes group, where I spent the next twenty-five pletes the components ofpaintchapters with anin
yearslearningwhatIamcommunicatinginthiswork. depthdiscussion aboutsolvents. Chapter 7isasum
Incontrasttotheearlierworks inthePDLFluo maryofadditives,thoseminorpaintcomponentsthat
rocarbon Series, this book is not only a reference often make or break the commercial success of a
bookbut alsomore tutorialinnature. Itteaches the fluorocoating.
practiceandtheoryoffluorinated coatings atevery Chapter 8 delves into preparing the substrate,
step. There are literally thousands ofpeople using the item being coated. This is a critical chapter as
thousands ofdifferentfluoropolymer coatings glo substratepreparationimpacts adhesion andeventu
bally.Much ofmytime with the DuPontcustomers ally the performance ofthe coated item.
hasbeen devotedtoteachingthebasics ofpaintfor Chapter9focuses onliquid fluorocoatings. In
mulation,howitimpactstheircoatingprocesses,and cludedinthis chapteraresome guidelines onmak
why things did not always work as expected. The ing coatings, both aqueous and non-aqueous, and
contents ofthis book should help them understand preparing them for use. There are also tables of
some ofthe problems encountered, interpret their commercialproductswithtechnologyandproperty
own observations, and arrive atpossible solutions. informationwhenitispubliclyavailable.Chapter 10
XVIII FLUORINATEDCOATINGSAND FINISHES HANDBOOK
summarizes the different ways liquid coatings are examples are included along withan explanation
applied andwhat formulation factors areimportant ofwhat causes the defects and possible ways to
ineachapplicationmethod. fixthem.
Chapter 11 focuses onpowder coatings. Itdis Chapter 15 contains a briefhistory offluoro
cusses the powder formulations, commercialpow coating developmentandsummariesofmany com
derproducts, andtheapplicationofpowders,includ mercialuses offluorocoatings.Ahistoryofcoating
ingthe equipmentandhow itworks. developmentstartsthechapter.Summaries ofmany
Chapter 12 is called "Fluoropolymer Coating uses offluorocoatingsarealsoincluded.
Processing Technology," but it essentiallyis about Chapter 16 is a discussion of many of the
baking orcuringthefluorocoatings. Included inthis health and safety aspects ofusing and applying
chapter are details about what happens during the fluorocoatings.
bake, alongwith thedifferenttechnologiesused for This work closes with a series of appendices
baking andmonitoringthatprocess. that contain useful details about the resistance of
Chapter 13moves on to coating performance. several fluoropolymers tomanychemicals andsol
Many of the performance tests used by coating vents. There is also a collection of select perme
manufacturers and end-users are discussed. Some ation data. Together these appendices areuseful in
ofthese are specification tests. Others are impor determiningthe fitness foruse ofcoatings based on
tantinhelping apotentialcustomerselect acoating. the various fluoropolymers in different exposure
Included are references to standard test protocols. environments.
Chapter 14 is related to performance, but it deals Iamateacheratheart. Ihope youwill findthis
specificallywithcoatingdefects.Manyphotographic work instructiveanduseful.
Larry McKeen December, 2005
Sewell, New Jersey
Acknowledgments
This bookis asummaryofwhat Ihave learned learnedfromthem.Manyofthesectionsinthisbook
overmore than twenty-fiveyears atDuPont. Many haveresulted fromlectures anddiscussions onthose
colleagues' andcoworkers' direct andindirecthelp subjectswithcustomers.Theirquestionshavehelped
hasleadtomyunderstandingofthefluorinatedcoat focus and crystallizethis work andmyunderstand
ing technologies. Some ofthe them include, in no ing ofthetechnology. The anticipationandinterest
particular order, Mr. Michael Witsch, Mr.William ofthis work has been aconstantmotivationforme
McHale, Mr.W.DouglasObal,Dr.PaulNoyes, Dr. to complete it and Ithank them allforthat.
Hank Jakubauskas, Dr. Michael Fryd, Mr. Craig Theauthorisespeciallyappreciative ofthecon
Hennessey, Mr. June Uemura, Mr. Fumio Inomae, fidence, support, andpatienceofmy friend andedi
Mr. Thomas Concannon (deceased), Dr. Milt torSinaEbnesajjad.Withouthissupportandencour
Misogianes, Dr. Peter Huesmann, Dr. Seymour agement, my work on this book would have been
Hochberg, Mr.Luk D'Haenens, Mr. Philippe Tho further delayed orperhaps abandoned. Hewas also
mas, Dr. CliffStrolle (deceased), and Dr. Kenneth the primaryproofreaderofthemanuscript.
Leavell. Dr.Charles DeBoerpersuadedmetocome The supportforthis book from my direct man
to DuPont and was a mentor to me for years. IfI agement, Dr. William Raiford and Dr. George H.
haveoverlookedanyone,pleaseforgivemeanddrop Senkler,issincerelyappreciated.
thepublisheranote forcorrectioninfuture editions. I am sincerelythankful forthe supportand pa
A number ofteachers have greatly influenced tience from my editor at William Andrew Publish
my educationanddeserve specialthanks. Ms.Anna ing, Ms. Millicent Treloar. I thank Ms. Jeanne
Kruse, my high school chemistry teacher (Lyman Roussel andherstaffatWriteOnefornotonlycom
HallHigh School, Wallingford, CT),not onlywasa posingthe manuscriptinto abook, but forthe final
great educator but also motivated this particular proofreading. Theynoticednumerous passages that
young studentto study chemistrybeyondthe class werenotclearlyexplained.Theserewrittenpassages
room. That included writing articles for an educa enhancedthe clarity ofthebook.
tional chemistrymagazine whileinhighschool, and My family has been particularly supportive
after-schoolprojects, onethat eventuallyled to the throughthelonghours ofwritingandresearchfrom
1969International ScienceFair.Themany outstand my home office. My wife, Linda, has been behind
ing chemistry teachers at Rensselaer Polytechnic this work 100percent. My childrenLindsey(ajun
Institute provided the best and most thorough un ior Biomedical Engineering/Premed major at
dergraduatechemistryeducationinthe country.Fi RensselaerPolytechnicInstitute), Michael (afresh
nally,mymajorprofessorattheUniversityofWiscon man businessmajoratJames MadisonUniversity),
sin,ProfessorJamesW.Taylor,was agreateducator and Steven (a high school junior at St. Augustine
andultimatelydevelopedmyteaching abilities. Prep)were directly supportive throughtheirinterest
I have taught much to our customers, but they andbyconstantlyinquiringaboutthebook'sstatus.
probably do not realize how much more I have
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Fluoropolymer coatings are widely used in many
industries, though the consumer and many engineers
The story of the discovery of fluoropolymers by
and scientists are only aware of their use as non-
DuPont has been related by many. It began not by a
stick coatings for cookware. There are hundreds of
well-designed purposeful experiment based on po-
applications, some of which are discussed later in
lymerization or organic chemistry. The first fluo-
this book. This work will be useful to students, engi-
ropolymer was discovered by accident. Dr. Roy
neers, paint applicators, and the end-users that buy
Plunkett (earned his Ph.D. at Ohio State University
and specify fluoropolymer-coated parts.
in 1936) of the DuPont Company was the image of
This book aims to:
a classical chemist: ingenious, but more important,
1. Provide information on coating formula- observant.[3] In 1938, he had been at DuPont for
tion including what is in a fluoropolymer only two years and was doing research on the de-
paint and why. velopment of fluorinated refrigerants in a joint ven-
2. Provide guidelines on the performance ture of DuPont and General Motors called Kinetic
of the various types of coatings to aid in Chemicals.
selection or provide an understanding on This work took place in what is now known as
why some coatings work or do not work DuPonts Jackson Laboratory on the site of the
in an application. Chambers Works in New Jersey across the Dela-
ware River from Wilmington. It is now in the shadow
3. Provide collections of data on raw mate-
of the Delaware Memorial Bridge. He was experi-
rials for potential formulators.
menting with tetrafluoroethylene (TFE) looking for
4. �Provide application and curing informa- a synthetic route to a useful refrigerant (CClF
tion. 2
CHF ).[4] The effort was spurred by the desire to
2
The first two volumes of this series cover in de- create safe, nonflammable, nontoxic, colorless, and
tail the technology of the fluorinated polymers that odorless refrigerants.
are used as raw materials in fluorinated coatings. It On the morning of April 6, 1938, when Plunkett
is important to understand what these important raw checked the pressure on a cylinder of TFE that he
materials are and what their properties are because was certain was full, he found no pressure. Many
they are imparted to the coatings in which they are chemists might have thought the cylinder had leaked
used. One may also want to understand the short- its contents, but the observant Plunkett noted that
comings or limits of the finishes. The first two vol- the cylinder had not lost weight. Charles Pederson
umes of this series cover in great detail the chemis- reflected on this day in his Nobel Laureate lecture
try and use of the raw fluoropolymers.[1][2] Those of December 8, 1987,
. I noticed commotion in
texts provide extensive property comparisons. This the laboratory of Roy Plunkett, which was across
book on coatings could not possibly contain perfor- the hall from my own. I investigated and witnessed
mance properties of all fluorinated coatings because the sawing open of a cylinder from which was ob-
they number in the thousands. tained the first sample of Teflon® fluoropolymer.
While there are literally thousands of fluorine- After opening, shaking the cylinder upside down
containing polymers described in the technical and yielded a few grams of a waxy looking white pow-
academic literature and those known only in the labo- derthe first polymer of �������������������. (See
ratory, this work will focus on the commercially avail- Fig. 1.1.)
able materials. Plunkett analyzed the white powder and it was
conclusively proven to be �����������������������
2 F C F H
LUORINATED OATINGS AND INISHES ANDBOOK
(PTFE). The slippery PTFE could not be dissolved PTFE and copolymers of other monomers and TFE
in any solvent, acid, or base, and upon melting formed have been developed and commercialized.
a stiff clear gel without flow. Later, research led to The words of Plunkett himself best summarize
the discovery of processing techniques similar to the discovery of PTFE. He recounted the story of
those used with metal powders (sintering). At the Teflon® in a talk to the American Chemical Society
time, the Manhattan Project was seeking new cor- at its April 1986 meeting in New York. The discov-
rosion-resistant materials for gaskets, packings, and ery of polytetrafluoroethylene (PTFE) has been vari-
liners for UF handling. PTFE provided the answer ously described as (i) an example of serendipity, (ii)
6
and was used in production. The US government a lucky accident, and (iii) a flash of genius. Perhaps
maintained a veil of secrecy over the PTFE project all three were involved. There is complete agree-
until well after the end of World War II. For security ment, however, on the results of that discovery. It
reasons, it was called by a code name, K 416. The revolutionized the plastics industry and led to vigor-
US government took all of the output from the small, ous applications not otherwise possible. The dis-
heavily guarded, production plant located in Arling- covery created a new industry, with annual sales of
ton, New Jersey. Commercial production was there- fluoropolymers over $2 billion and value-added to
fore delayed until 1947. Plunkett patented it in US tens of billions dollars. Fluoropolymers have entered
Patent 2,230,654 on February 4, 1941. Because of every aspect of human life, often unseen yet func-
the secrecy, no other patents issued until Brubakers tional, and the extension of fluorine chemistry has
patent 2,393,967 in 1947. revolutionized many industries from pharmaceutical
Large-scale monomer synthesis and controlled to prosthetics to crop protection to space craft.
polymerization were technical problems to be re-
solved. Intensive studies solved these problems and
small-scale production of Teflon® (trademarked in 1.3 What are Fluoropolymers?
1944, but not publicly revealed until 1946) began in
1947. In 1950, DuPont scaled up the commercial The following sections briefly explain the struc-
production of Teflon® in the USA with the construc- tures and properties of the various fluoropolymers.
tion of a new plant in Parkersburg, West Virginia. In It is important to keep in mind there are variations of
1947, Imperial Chemical Industries built the first most of these polymers. The most common variation is
PTFE plant outside the US, in Western Europe. Since the molecular weight, which will affect the melting
then, many more plants have been built around the point somewhat, and the viscosity of the polymer
globe. Over the last six decades, many forms of above its melt point, properties that are very impor-
tant in determining processing conditions and use.
1.3.1 Perfluorinated Polymers
Traditionally, a fluoropolymer or fluoroplastic is
defined as a polymer consisting of carbon (C) and
fluorine (F). Sometimes these are referred to as per-
fluoropolymers to distinguish them from partially
fluorinated polymers, fluoroelastomers, and other
polymers that contain fluorine in their chemical struc-
ture. For example, fluorosilicone and fluoroacrylate
polymers are not referred to as fluoropolymers.
1.3.1.1 Polytetrafluoroethylene (PTFE)
Figure 1.1 Photograph of two pages from the research
An example of a linear fluoropolymer is the tet-
notebook of Dr. Roy Plunkett recording the discovery
rafluoroethylene polymer (PTFE) discovered by
of polytetrafluoroethylene on April 6, 1938.����������
Plunkett. Its structure in simplistic form is:
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