World Surface Coatings Abstracts (WSCA) - Highlights 2007
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WSCA Highlights of the Month - December 2007
The December 2007 issue of WSCA contains abstracts of 611 articles
including the following examples:
Section 05 Solvents, Plasticisers and
Intermediates
MATHERS R T, McMAHON K C & BAKER J R Utilising d-limonene as a
chain transfer agent and renewable solvent for ring-opening metathesis
polymerisations. ACS, Div. of PMSE, Papers 2007, Vol 96,
842.
Molecular weights (and distributions) were measured for ring-opening
metathesis polymerisation of 1,5-cyclooctadiene in d-limonene, toluene
and hydrogenated d-limonene, and the metathesis product of d-limonene
and n-hexene was examined by proton nuclear magnetic resonance.
D-limonene is a renewable polymerisation solvent for ring-opening
metathesis polymerisations (ROMP). D-Limonene belongs to a broad class
of naturally occurring isomers which contain 10 carbon atoms. It is
produced in large quantities as a by-product of the citrus industry.
Conducting ROMP of 1,5-cyclooctadiene in d-limonene substantially
reduces the polymer molecular weight. The formation of a trisubstituted
alkene that occurs during chain transfer was observed by proton nuclear
magnetic resonance. Since d-limonene does not require synthetic
modification, it has wide-ranging potential as a chain transfer agent.
(WSCA Item Number 07/07202)
Section 53 Weathering, Corrosion, Etc
HOLLAND M & OTHERS Ozone damage to paint and rubber goods in the
UK. Pollution Atmospherique 2007, October, Special Issue,
73-93.
Various decorative, motor vehicle, powder, general industrial,
protective, marine, coil, and agricultural/construction/earth moving
(ACE) coatings, and paints for plastics, were subjected to accelerated
testing (exposure to 5000 ppb ozone over 22 days), and three decorative
and two motor vehicle coatings were selected for longer term (12 months)
exposure testing to near ambient ozone levels in open-top chambers.
Colour changes, gloss changes and chalking were assessed in both cases,
together with changes in flexibility, petrol resistance and water
resistance in the accelerated testing and changes in film thickness in
the longer term tests. Of the various parameters tested for paints is
was concluded that colour change was the most sensitive to ozone.
However, for an average paint it was found that it would take about 12
years for a noticeable colour change to be seen at ambient ozone
concentrations. As this was longer that the average lifetime of paint it
was concluded that significant economic damage from ozone was unlikely.
Although for some paints a noticeable colour change could arise from
exposure after perhaps only 3 years, this seems unlikely to result in
significant economic damage given the low market share of the paints and
the likelihood that the colour change would be relatively uniform over
the painted article. In economic terms it is concluded that there is no
significant economic cost associated with ozone damage to the UK paint
stock based on the behaviour of most paints and that a change in ozone
concentration of 3 ppb would have a negligible economic impact: a caveat
being that the analysis presented treats ozone on its own, without
reference to other stressors such as the sun, frost, rain, etc.
Paintwork on 151 automobiles was also surveyed, and from discussions
with garages it is noted that red automobiles start to discolour after 4
years, all other coloured automobiles start to discolour after 6-8
years. (WSCA Item Number 07/07439)
Section 63 Paints, Etc for Other Specific Uses
ANON Leaves of (painted) grass. JCT CoatingsTech
2007, Vol 4 No 8, 44-5.
The painting of grass, with applications that are currently designed to
make playing fields look the best, while being environmentally friendly,
easy to use, and long lasting, is discussed. The types of paint used as
well as the means of application are considered. Reference is made to
coatings not washing off in the rain but rather growing off after a few
mowings. (WSCA Item Number 07/07490)
Section 71 Other Properties and Testing Methods
NARHE R D & BEYSENS D A Growth dynamics of water drops on a
square-pattern rough hydrophobic surface. Langmuir 2007,
Vol 23 No 12, 6486-9.
Drops of water, condensed on to a hydrophobic surface comprising square
pillars, initially grew according to laws similar to those obeyed on
flat surfaces. However, a transition occurred in which water formed
bridges across the pillars. A second transition to a stabler state took
place, with self-drying of pillars. Drops grew by flow through adjacent
channels, whilst adjacent pillars remained almost dry. These phenomena
may be generalised to other, similar patterns, such as grooves. 25 refs.
(WSCA Item Number 07/07601)
A review of the following book also appeared in the
December 2007 issue of WSCA: book reviews can be read on the
Library Catalogue page of the PRA web site. link.
ANON Australia's identified mineral resources 2007.
Geoscience Australia, Canberra 2006, 102 pp. (ISSN 1327-1466,
available at www.ga.gov.au).
(WSCA Item Number 07/07768)
For further information on WSCA please contact Dr Norman Morgan
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WSCA Highlights of the Month - November 2007
The November 2007 issue of WSCA contains abstracts of 614 articles
including the following examples:
Section 02 Patents: Pigments, Extenders, Dyestuffs and
Phosphors
BRETON SPA Process for the production of titanium
dioxide. European Patent Application 1727769, 24 pp. (Also
PCT WO 2005/090235).
A process for production of titanium dioxide is disclosed, comprising
the steps of reacting a titanium ore containing iron, preferably
ilmenite, with an aqueous ammonium fluoride solution, filtering the
aqueous suspension thus obtained with consequent separation of a sludge
fraction, which contains ammonium fluoroferrates, and a filtrate
fraction, which contains ammonium fluorotitanates, subjecting the
filtrate fraction thus obtained to an hydrolysis reaction, and
subjecting the thus obtained solid component to a thermal hydrolysis
reaction. (WSCA Item Number 07/06559)
Section 21 Nitrogenous Polymers
MORAVEK S J & OTHERS Degradable thermoplastic polyurethanes
based on dicyclohexylmethane-4,4'-diisocyanate. ACS, Polym.
Preprints 2007, Vol 48 No 1, 568-9.
Degradable thermoplastic polyurethanes based on dicyclohexylmethane
diisocyanate and various polyester polyols were synthesised and were
characterised. The development of degradable materials, such as these,
that offer good mechanical properties over a wide temperature range will
enable the use of degradable materials over traditionally non-degradable
ones. (WSCA Item Number 07/06658)
Section 49 Pretreatment and Application
SIMON J Automated programming for efficient spray painting of
small batches. Metalloberflaeche 2007, Vol 61 Nos 7/8,
14-5.
Fully automated programming for spray painting is described, which
enables the efficient coating of small batch numbers of parts of varying
geometries. Numerous cameras scan the part to be coated, thus building
up a three-dimensional image of the part. The system is also able to
work how to coat the part without the risk of any collisions between
robots. (In German) (WSCA Item Number 07/06818)
Section 55 Fouling and Microbiological Attack
OLSEN S M & OTHERS Enzyme-based antifouling coatings: a
review. Biofouling 2007, Vol 23 No 5, 369-383.
A systematic overview is presented of the literature that reports the
antifouling protection of underwater structures via the action of
enzymes. The overall aim of this review is to assess the state of the
art of enzymatic antifouling technology, and to highlight the obstacles
that have to be overcome for successful development of enzymatic
antifouling coatings. The approaches described in the literature are
divided into direct and indirect enzymatic antifouling, depending on the
intended action of the enzymes. Direct antifouling is used when the
enzymes themselves are active antifoulants. Indirect antifouling refers
to the use of enzymes to release an active biocide with antifouling
activity. For direct antifouling, several patents have been granted, and
a commercial product has been launched. However, the achievement of an
efficient broad-spectrum antifouling coating based on a single or a few
enzymes has not yet been achieved. An indirect antifouling coating is
not yet available commercially. The technology is mainly limited by the
instability of substrate supply, whether the substrates are found in the
surrounding sea water or in the coating itself. Legislative issues
regarding which part(s) of an enzyme system should be regarded as
biocidal for product registration purposes are also considered. 51 refs.
(WSCA Item Number 07/06883)
Section 69 Analytical Methods
WHITE J, PENGELLY I & COLDWELL M Development of analytical
methods for low molecular weight isocyanates in workplace air.
Health & Safety Laboratory Publication HSL/20(WSCA Item Number
07/47, 2007, 38 pp. (Available at www.hse.gov.uk).
Methods were developed for the determination of low molecular weight
isocyanates (NCO), especially isocyanic acid and methyl isocyanate,
other monoisocyanates and diisocyanate monomers. These species are
produced by thermal degradation of isocyanate-derived polyurethanes at
high temperatures. These high temperatures may be produced during
machining of polyurethane painted parts, e.g, in motor vehicle repair
(MVR) shops or during flame bonding of polyurethane foams. Initially,
two liquid chromatography (LC) methods were developed, one using an
octadecylsilane (C18) column, the other a graphitised carbon column,
both with selected ion monitoring (SIM) mass spectrometry. Because of
the failure of the two methods for isocyanic acid and methyl isocyanate,
a third method (III), using the graphite column was developed. In this
method methanol was used to improve liquid chromatography selectivity.
Acceptable performance was achieved. (Shortened version of original
abstract). 13 refs. (WSCA Item Number 07/06977)
Reviews of the following books also appeared in the
November 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
CORK A (EDITOR) Polymers Paint Colour Journal (PPCJ) Yearbook
2008. DMG World Media (UK) Ltd, Redhill (Surrey) 2007, 246
pp. (ISBN 1-84313-052-1). Price £155.00 (UK), £163.00
(elsewhere).
(WSCA Item Number 07/07151)
KARPOV V A, KOVALCHUK Iu L, POLTARUKHA O P & ILIN I N
Compilation of Methods for Protection from Marine Fouling and
Corrosion. Tovarishchestvo Nauchnkh Izdanii KMK, Moscow
2007, 158 pp. (ISBN 978-5-87317-402-7).
(WSCA Item Number 07/07153)
ZARRAS P, BENICEWICZ B C, WOOD T & RICHEY B (EDITORS) New
Developments in Coatings Technology. ACS Symposium Series
962, American Chemical Society, Washington DC 2007, 348 pp. (ISBN
0-8412-3963-0). Price $145.00.
(WSCA Item Number 07/07156)
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WSCA Highlights of the Month - October 2007
The October 2007 issue of WSCA contains abstracts of 620 articles
including the following examples:
Section 08 Patents: Driers and Minor Additives
CIBA SPECIALTY CHEMICALS HOLDING AG Multipurpose additive for
low volatile organic compound (VOC) solvent based coatings.
World (PCT) Patent Application 2007/082815, 14 pp.
A coating composition is disclosed which comprises at least one binder
and a multipurpose additive, the additive being obtainable by reacting a
vegetable oil with a diol or by transesterifying a vegetable oil lower
alkyl ester with a diol, both reactions in the presence of a catalyst.
The multipurpose additive is used to replace partly the solvent of the
coating compsn. and/or to replace partly the binder thus reducing the
VOC content and the viscosity. (WSCA Item Number 07/05980)
Section 67 Mechanical and Rheological Properties
HERRMANN T Avoiding adhesion problems with powder
coatings. Besser Lackieren 2007, Vol 9 No 5, 10.
It is noted that when applying powder coatings on to cathodic
electrocoating dip coated materials, adhesion problems often occur. Some
of the reasons for these problems, and ways of avoiding them, are
outlined. In particular, pretreatment processes must be carefully
considered in advance, and compatible coating systems should be chosen.
(In German) (WSCA Item Number 07/06379)
Section 73 Industrial and Other Hazards
HELLAND A & OTHERS Reviewing the environmental and human health
knowledge base of carbon nanotubes. Environ. Health
Perspectives 2007, Vol 115 No 8, 1125-31.
Current literature on the potential risks of carbon nanotubes (CNTs) to
human health and the environment is reviewed. In order to address some
of the questions (knowledge gaps) revealed by the literature review,
seven scientists eminent in the field (i.e, key authors or project
leaders who have investigated and reported on the potential impact of
CNTs on human health and the environment) were interviewed and their
knowledge was integrated into the review. It is noted that there are
different types of CNTs and therefore they cannot be considered as a
uniform group of substances. Exposure in occupational settings and via
environmental media and both in vivo and in vitro toxicological studies
are included. The possibility of different health and environmental
impacts dependent on a stage in the life-cycle of CNTs is also examined.
The toxicity of CNTs is dependent on a number of factors that are
influenced by external environmental conditions during its life-cycle
(e.g. production, use and disposal). There is evidence to show that CNTs
are bioavailable to different organisms as well as being biopersistent,
therefore, the possibility that CNTs may accumulate along the food chain
is unable to be excluded. It is recommended that knowledge about
toxicology be combined with information about the life-cycle of the CNT.
Responsible management of the potential risks of CNTs to human health
and the environment is considered to be important to their successful
introduction into new applications that are constantly emerging. 60
refs. (WSCA Item Number 07/06428)
MONTEILLER C & OTHERS Pro-inflammatory effects of low-toxicity,
low-solubility particles, nanoparticles and fine particles on epithelial
cells in vitro: the role of surface area. Occup. Environ.
Med. 2007, Vol 64 No 9, 609-15.
An investigation was made as to whether the surface area is a better
descriptor than mass of low-solubility low-toxicity particles (LSLTP) in
their ability to stimulate pro-inflammatory responses in vitro. These
responses were measured in a human alveolar epithelial type II-like cell
line using certain materials as markers of pro-inflammatory effects and
oxidative stress. In all the assays, nanoparticle preparations of
titanium dioxide and of carbon black produced much stronger
pro-inflammatory responses than the same mass dose of fine titanium
dioxide and carbon black. The results of a glutathione (GSH) assay
confirmed that oxidative stress was involved in the responses to all the
particles. Two ultrafine metal dusts (cobalt and nickel) produced
glutathione depletion similar to titanium dioxide nanoparticles for
similar surface area dose. Specified quartz was found to be more
inflammatory than the low toxicity dusts, on both a mass and surface
area basis. It was concluded that surface area was a more appropriate
dose metric than mass for assessing pro-inflammatory effects of
low-solubility, low-toxicity particles in vitro and in vivo. 47 refs.
(WSCA Item Number 07/06433)
Reviews of the following books also appeared in the October 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
MITTAL K L (EDITOR) Adhesion Aspects of Thin Films, Volume
3. VSP BV, Leiden & Boston 2007, 276 pp. (ISBN
978-90-6764-455-6). Price 120.00 euros, $162.00. (WSCA Item Number 07/06541)
MITTAL K L (EDITOR) Polymer Surface Modification: Relevance to
Adhesion, Volume 4. VSP BV, Leiden & Boston 2007, 305 pp.
(ISBN 978-90-6764-453-2). Price 147.00 euros, $198.00. (WSCA Item Number 07/06542)
MITTAL K L (EDITOR) Silanes and Other Coupling Agents. Volume
4. VSP BV, Leiden & Boston 2007, 409 pp. (ISBN
978-90-6764-452-5). Price 179.00 euros, $242.00. (WSCA Item Number 07/06543)
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WSCA Highlights of the Month - September 2007
The September 2007 issue of WSCA contains abstracts of 616 articles
including the following examples:
Section 17 Oxygenated Polymers
KAINTHAN R K & BROOKS D E Synthesis, characterisation and
properties of very high molecular weight and narrowly dispersed
hyperbranched polyglycerols. ACS, Polym. Preprints 2006, Vol 47
No 2, 722-3.
Hyperbranched polyglycerols were prepared using higher monomer to
initiator ratios in the presence of emulsifying solvents, the process
being ring-opening multi-branching polymerisation of glycidol. Because
of the low viscosity, and high functionality the polymers are expected
to find application as cross-linkers, additives and rheology modifiers.
They could also be used as components of adhesives, coatings, hydrogels
and composites, and also in catalysis, drug delivery and nanotechnology.
Polydispersity values were found to increase with MW. High MW was
achieved with bis(2-methoxyethyl)ether as emulsifying solvent, and yield
was good with this solvent. Dioxane was also successful, providing high
MW and narrow polydispersity. Samples could be cleaned of low MW
fractions by dialysis. The functionality of the highest MW material is
calculated to be 12,000 in hydroxyl groups, this particular material
being stated to have great potential in nanotechnology. (WSCA Item
Number 07/05396)
Section 35 Water-borne Paints and their
Components
DIMMERS M Solvent-free polyurethane dispersions based on
vegetable oils. Farbe Lack 2007, Vol 113 No 5, 176 (3
pp).
A new generation of solvent-free polyurethane dispersions for use on
wooden floors and furniture is described. The new dispersions are based
on vegetable oils, and do not contain either N-methyl-2-pyrrolidone
(NMP) or other solvents. They exhibit good chemical and mechanical
resistance, and their cost is less dependent on crude oil prices. (In
German) (WSCA Item Number 07/05472)
Section 53 Weathering, Corrosion, Etc
BOISSEAU J, CAMPBELL D, MARINO M & BRENNAN P J Accelerated acid
etch for motor vehicle clear coats: II. Paint & Coatings Ind.
(US) 2007, Vol 23 No 6, 46 (7 pp).
A specific accelerated acid test is discussed that provides many
advantages for the testing of acid etch damage on motor vehicle clear
coat systems. The procedure allows for faster development of
etch-resistant coatings. Up to 20 iterations per year may be performed
using this method versus 1 iteration per year as dictated by natural
Jacksonville exposures. The procedure has been modified to make it more
practical for laboratories to perform. It is noted that instrumental
analysis techniques have been shown to enhance understanding of etch
damage, and that a zero degree orientation has been demonstrated to
provide the fastest and most realistic etch results compared to real
world data. Data show that panels may be used as exposure substrates
versus actual automobile bonnets to save time and expense. It is
concluded that the procedure should allow a reduction in the number of
acid etch failures seen in service. 10 refs. (WSCA Item Number
07/05583)
Section 79 Radiation Curing
CHEN X, HU Y, JIAO C & SONG L Thermal and ultraviolet curing
behaviour of phosphate diacrylate used for flame-retardant
coatings. Progr. Org. Coat. 2007, Vol 59 No 4, 318-23.
A novel 'phosphorus-on-skeleton' compound was synthesised by allowing
phosphorus oxychloride to react with
1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo(2,2,2)octane (PEPA)
and 2-hydroxyethyl acrylate (HEA). Conversion of the unsaturated bond of
the monomer exposed to UV light for 100 seconds was approximately 84%.
The limiting oxygen index (LOI) value was 39 and the char yield was 53%
at 600 deg. C. Thermogravimetric analysis indicated that the material
undergoes degradation in three characteristic temperature stages, which
may be attributed to the decomposition of the phosphate, thermal
pyrolysis of aliphatic chains, and degradation of an unstable structure
in char, respectively. It is proposed that the flame retardant action
results from decomposition of phosphate to form poly(phosphoric acid),
which catalyses the breakage of bonds adjacent to carbonyl groups to
form an intumescent char, preventing the sample from burning further. 20
refs. (WSCA Item Number 07/05795)
Reviews of the following books also appeared in the September 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
GEOSCIENCE AUSTRALIA Australia's identified mineral resources
2006. Geoscience Australia, Canberra 2006, 107 pp. (ISSN
1327-1466, available at www.ga.gov.au). (WSCA Item Number
07/05922)
HEILIG M Deutsches Taschenbuch fur Maler und Lackierer 2007
(German Handbook for Painters 2007). 2 volumes. Verlag Georg D
W Callwey, Munchen 2007, 272 128 pp. (ISBN 13-978-3-7667-1694-1). Price
15 euros. (WSCA Item Number 07/05923)
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WSCA Highlights of the Month - August 2007
The August 2007 issue of WSCA contains abstracts of 604 articles
including the following examples:
Section 07 Driers and Minor Additives
DESAI N & SARDESAI A Journey through nanotechnology: coating
industry perspective. Paintindia 2007, Vol 57 No 3, 83 (12
pp).
An overview is presented for helping to develop the understanding of the
importance and implications of nanotechnology to the coatings industry.
Definitions of nanotechnology and its historical progress are presented
together with types of nanomaterials (nanocrystalline, quantum dots,
fullerenes, carbon nanotubes, dendrimers, nanocomposites, methods of
producing nano-sized particles (sol/gel process, chemical vapour
deposition, etc), characterisation, significance of nanoparticles in
coatings, nanomaterials as additives in coatings industry (aluminium
oxide, titanium dioxide, cerium oxide, silica and zinc oxide),
nanocomposites in surface coatings, major use areas (wood coatings,
biocidal coatings, self-cleaning paint layer, abrasion resistance, and
non-chromate corrosion inhibitor), and the future of nano-coatings. It
is noted that nanotechnology may be used for anti-graffiti paints,
coatings on plastic, food and packaging material, coatings for
automobiles, and scratch- or abrasion-resistant coatings, that for
coatings, various nanoscale materials are available commercially either
in powder form or dispersions, and that the incorporation of different
nanoparticles such as titanium dioxide, silica, clays, zinc oxide, iron
oxide and their combinations, show substantial improvement in various
properties including increased mechanical properties, decreased
permeability of gases, enhanced thermal stability, improvement in flame
retardancy, increased chemical and heat resistance, and improvement in
anticorrosive properties. 26 refs. (WSCA Item Number 07/04766)
Section 15 Hydrocarbon Polymers
RAJAN M & OTHERS Synthesis and characterisation of model
dumb-bell polymers. Macromol. 2007, Vol 40 No 9,
3080-9.
Toluene solutions of phosgene were used to couple polystyrene having
hydroxyl groups at both chain ends, with two molecules of
poly(chloromethystyrene) having a single hydroxyl end group. The pendent
chloromethyl groups on the outer blocks of the resulting triblock
copolymer were used as initiating sites for multiple atom transfer
radical polymerisation of additional styrene. This bulking of the outer
blocks constituted formation of the end parts of the dumb-bell
structures, which was confirmed by size exclusion chromatography and
visualised by scanning force microscopy. Number-average molecular weight
values of the outer blocks were determined after alkaline hydrolysis of
the in-chain carbonate linkages. 44 refs. (WSCA Item Number
07/04793)
Section 53 Weathering, Corrosion, Etc
CLASSEN A & RENTSCHLER T Contribution of small particles to
corrosion control in thin-film ultraviolet-cured coatings.
Proc. European Coatings Conf. 'New Concepts for Anticorrosive Coatings',
Berlin 2007, Paper, 45-66.
Barium sulphate with a medium particle size of 1 micrometre and an
inorganic barium sulphate additive with a medium particle size of 0.04
micrometres were tested for their influence on the performance of
thin-film UV-cured coil coatings. Various coil coating systems were
examined. It was concluded that nano-barium sulphate supports UV-cured
coil coating primers by improved adhesion, improved substrate wetting,
flow and smoother surface, improved corrosion resistance,
reproducibility of results, thin film applications, and no negative
effects on gloss. The possible functions of the inert nano-sized
material are listed as less shrinkage and strain within the coating, the
influencing of penetration of water and oxygen/barrier effect, and
better adhesion properties/interaction with polymer molecules. The
corrosion resistance does not depend on the binder system used but
appears to be of general use. (WSCA Item Number 07/04981)
Section 55 Fouling and Microbiological Attack
YEE L H & OTHERS Inhibition of fouling by marine bacteria
immobilised in kappa-carrageenan beads. Biofouling 2007, Vol 23
No 4, 287-94.
The immobilisation of the antifouling bacterium Pseudoalteromonas
tunicata in kappa-carrageenan was employed to demonstrate how a surface
might be protected from fouling by bacteria, i.e. a 'living paint'.
Attempts so far to produce a 'living paint' have been limited in both
longevity of effectiveness and demonstration of applicability, most
noticeably regarding the lack of any field data. Survival of bacteria
immobilised in kappa-carrageenan for 12 months in the laboratory is
demonstrated and evidence presented for inhibition of fouling for up to
7 weeks in the field (Sydney Harbour, New South Wales, Australia). 38
refs. (WSCA Item Number 07/05024)
Section 73 Industrial and Other Hazards
WARHEIT D B & OTHERS Development of a base set of toxicity tests
using ultrafine titanium dioxide particles as a component of
nanoparticle risk. Toxicol. Lett. 2007, Vol 171 No 3,
99-110.
The toxicity results of a base set of hazard tests on a set of newly
developed, well-characterised, ultrafine titanium dioxide particle-types
are presented. In vivo pulmonary toxicity investigations in rats
demonstrated low inflammatory potential and lung tissue toxicity. Acute
dermal irritation studies in rabbits and local lymph node assay results
in mice indicated that ultrafine titanium dioxide was not a skin
irritant or dermal sensitiser. Acute oral toxicity studies demonstrated
very low toxicity and ultrafine titanium dioxide produced short-term and
reversible ocular conjunctival redness in rabbits. Genotoxicity tests
demonstrated that ultrafine titanium dioxide was negative in both the
bacterial reverse mutation test and in an in vitro mammalian chromosome
aberration test with Chinese hamster ovary cells. The results of aquatic
toxicity screening studies demonstrated that ultrafine titanium dioxide
exhibited low concern for aquatic hazard in unaerated, 48 hour, static
acute tests using the water flea, Daphnia magna, that it exhibited low
concern for aquatic hazard in unaerated, 96 hour, static acute tests
using the rainbow trout, Oncorhynchus mykiss, and that it exhibited
medium concern in a 72 hour acute test using the green algae
Pseudokirchneriella subcapitata. The results of most of the
investigations demonstrated low hazard potential in mammals or aquatic
species following acute exposures to the ultrafine titanium dioxide
particle-types tested in this programme. 24 refs. (WSCA Item Number
07/05210)
Reviews of the following books also appeared in the August 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
BENHAM A J & BROWN T J African Mineral Production
2001-2005. British Geological Survey, Keyworth (Nottingham)
2007, 21 pp. (ISBN 978-0-85272-597-9, available at www.mineralsuk.com).
Price (print version) £15.00. (WSCA Item Number 07/05303)
BROWN P J China and South-east Asia Mineral Production
2001-2005. British Geological Survey, Keyworth (Nottingham)
2007, 16 pp. (ISBN 980-0-85272-598-6), available at www.mineralsuk.com).
Price (print version) £15.00. (WSCA Item Number 07/05304)
HETHERINGTON L E & OTHERS United Kingdom Minerals Yearbook
2006. British Geological Survey, Keyworth (Nottingham) 2007,
110 pp. (ISBN 978-085272604-4, available as
www.bgs.ac.uk/mineralsuk/commodity/uk/ukmy.html). Price (print version)
£25.00. (WSCA Item Number 07/05305)
HETHERINGTON L E & OTHERS European Mineral Statistics
2001-2005. British Geological Survey, Keyworth (Nottingham)
2007, 333 pp. (ISBN 978-0-85272-593-1 (Download)/ISBN 978-0-85272-594-8
(Paperback), available at www.mineralsuk.com). Price (print version)
£55.00. (WSCA Item Number 07/05306)
HETHERINGTON L E & OTHERS World Mineral Production
2001-2005. British Geological Survey, Keyworth (Nottingham)
2007, 88 pp. (ISBN 978-0-85272-592-4, available from
www.mineralsuk.com). Price (print version) £30.00. (WSCA Item Number 07/05307)
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WSCA Highlights of the Month - July 2007
The July 2007 issue of WSCA contains abstracts of 654 articles
including the following examples:
Section 53 Weathering, Corrosion, Etc
KEAR G & OTHERS Metallic materials selection for timbers treated
with non-copper/chrome/arsenate-based, copper-rich preservatives:
implications for Australasia. Corros. & Materials 2007, Vol 32
No 1, 16-21.
Investigations on the relative durability of mild steel, hot-dipped
galvanised mild steel and stainless steel materials in untreated,
copper/chrome/arsenate (CCA) treated, copper azole-treated, and alkaline
copper quaternary treated timbers (Pinus radiata-based) are summarised.
Using accelerated standard test methodologies, mild steel corrosion
rates in contact with copper azole-based and alkaline copper
quaternary-based treated timbers were observed to increase, at a
specified hazard level, by a factor of up to five relative to the
equivalent copper/chromium/arsenic treated timber. 38 refs. (WSCA Item
Number 07/04368)
Section 56 Patents: Fouling and Microbiological
Attack
JANSSEN PHARMACEUTICA NV Use of mitochondrial electron transport
inhibitors to control fouling organisms. World (PCT) Patent
Application 2006/097479, 17 pp.
The use of mitochondrial electron transport inhibitors (METI) for
protecting materials against fouling by marine or freshwater fouling
organisms is disclosed, together with an antifouling composition
suitable for use therefor. The invention thus relates to the field of
protection of materials that are exposed to humid or aqueous
environments. The inhibitor is selected from the group consisting of
fenazaquin, fenpyroximate, piericidin A, pyridaben, pyrimidifen,
rotenone, tebufenpyrad, and tolfenpyrad. The compsns. may be in the form
of an emulsifiable concentrate, suspension concentrate, or soluble
concentrate, or may be in the form of a paint, coating or varnish. (WSCA
Item Number 07/04412)
Section 61 Coatings for Paper, Wallpaper and
Plastics
BARLETTA M Photocatalytic 'self-organising' coatings on
plastics: materials, processes and products performance. Proc.
European Coatings Conf. 'Modern Coatings for Plastics Substrates III',
Berlin 2007, Paper, 1-14.
The preparation, application and use of transparent photocatalytic
coating systems applicable on plastics surfaces are discussed. First,
the role of base materials in coating preparation is considered.
Particular attention is devoted to the preparation and surface
modification of nanoscaled photocatalytically active titanium dioxide
particles, as well as to the selection and role of the binder and
solvents for sol-based mixture (i.e, for wet coating) and of polymer
particles for thermosetting powder coating (i.e, for dry coating). Wet
film deposition by dip and spin coating and dry film deposition by spray
coating were comparatively evaluated and mechanisms established. It was
possible to obtain an elevated concentration of the active titanium
dioxide particles at the interface layer between coating and air for
both wet and dry applied coatings. The coatings performance was
evaluated after activation by irradiation with artificial UV radiation,
highlighting the transitions between superhydrophobic and
superhydrophilic behaviour of the coating surface. 21 refs. (WSCA Item
Number 07/04423)
Section 75 Pollution and Utilisation of Wastes
LIN C-C & CORSI R L 2,2,4-trimethyl-1,3-pentanediol
monoisobutyrate ester alcohol emissions from latex paints: temporal
variations and multi-component recoveries. Atmospheric
Environment 2007, Vol 41 No 15, 3225-34.
Emissions were investigated of 2,2,4-trimethyl-1,3-pentanediol
monoisobutyrate (I) from two latex paints applied to three substrates
(aluminium, gypsum board, and concrete). The first 48 hours of each
experiment involved small chamber testing. Specimens were then
maintained in an office environment with intermittent rotation into
chambers. Emission rates were observed for periods as long as 15 months,
but were relatively low after 150 hours. Airborne recoveries of the
compound were a strong function of the type of paint and substrate.
Recoveries in air of approximately 50% (semi-gloss paint) to 90% (flat
paint) were observed after 15 months for regular applications to gypsum
board, but were less than 25% after 8-15 months for applications to
concrete. The compound was recovered in the dried paint film and
substrate (in the case of gypsum board) with 96% mass closure. 14 refs.
(WSCA Item Number 07/04578)
Section 88 Standards and Specifications
BRITISH STANDARDS INSTITUTION Paints and varnishes: comparison
of contrast ratio (hiding power) of paints of the same type and
colour. BS EN ISO 2814:2006, 2 pp. (ISBN 9780-0-580-50069-5,
available from www.bsi-global.com). Price £58.00.
The coatings are applied either to black and white cards or to polyester
film. In the case of the polyester film the measurements are made over
black and white glass plates. Reflectance is measured. (WSCA Item Number
07/04700)
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WSCA Highlights of the Month - June 2007
The June 2007 issue of WSCA contains abstracts of 640 articles including the following examples:
Section 02 Patents: Pigments, Extenders, Dyestuffs and Phosphors
ECKART GMBH Electrically-conductive pigments having a ferromagnetic core, the production thereof and their use. European Patent Application 1713867, 19 pp. (Also PCT WO 2006/018213).
Electrically conductive pigments having a ferromagnetic core and at least one electrically conductive coating are disclosed. The electrically conductive coating on the pigments is or comprises a metal or a metal alloy or is or comprises electrically-conductive polymers or plastics that contain electrically-conductive polymers. The invention also relates to a method for producing the electrically-conductive pigments as well as to the use of these electrically-conductive pigments (e.g, conductive coatings, electromagnetic interference shielding coatings or objects, coatings, etc with orientation of the pigments in an electrical or magnetic field, and security documents). (In German) (WSCA Item Number 07/03437)
Section 49 Pretreatment and Application
BOMBARD I, LAURENT P, JEANDEL G & LIETO J Model of the cure of powder coatings based on surface absorptivities in-situ measurements. Proc. Federation of Societies for Coating Technology '2006 FutureCoat' (ICE 2006) Conf, New Orleans 2006, Paper, 26 pp.
An investigation was performed that was structured to develop a mathematical model using the radiative properties of the coating to describe precisely the coating temperature and degree of polymerisation conversion during the cure. Reflectance measurement results obtained with Fourier transform infrared spectroscopy equipped with an integrating sphere are analysed and implemented in a thermal model. These results showed that reflectance values vary with chemical composition and the pigment nature, and are influenced by the powder coatings cure. The thermal model, solved with the finite volume method, permits the computation of the varying temperature within the thickness of the powder-coated metal sample and provides a good prediction of the temperature within the 'coating plus substrate' system. The experimental cure of powder coatings supporting the investigation was carried out in a small test oven equipped with electrical infrared emitters. The paints were a polyester/triglycidyl isocyanurate and an epoxy/polyester. 15 refs. (WSCA Item Number 07/03699)
Section 51 Paint, Etc Removal
GREENWOOD M A Pulsed light peels away poisonous paint. Photonics 2007, Vol 41 No 2, 30-1.
A lead paint removal system for use in houses and apartments is discussed. It relies on high-intensity, less than 100 microsecond incoherent pulses of light, that vaporise the paint while a rotating brush sweeps the debris into an attached vacuum-like device, where it is safely processed through a series of filters. Early results indicate that the light-based ablation method may overcome many of the problems associated with lead removal. It is claimed that the technique minimises toxic by-products, reduces labour and could cost less than existing methods. The photolytic system relies on a patented surface discharge lamp technology. The lamp's xenon gas containment envelope is far enough away from the plasma discharge to allow the lamp to operate at the higher pulse energies and shorter pulse durations needed to strip the paint. The reflector helps remove paint from irregularly shaped areas such as corners, moulding and other decorative flourishes. Tests on removal of paint from wood are outlined. (WSCA Item Number 07/03724)
Section 73 Industrial and Other Hazards
HEALTH AND SAFETY EXECUTIVE Asbestos essentials (non-licensed tasks): removing textured coating from a small area, e.g, 1 square metre. Health & Safety Executive Leaflet a28, 2007, 3 pp. (Available as www.hse.gov.uk/pubns/guidance/a28.pdf).
Information is provided to help employers, and the self-employed, comply with the Control of Asbestos Regulations 2006. Good practice is described for when one needs to remove a small area of textured coating, e.g, around 1 square metre, in preparation for other work: the sheet is not appropriate for large area. If the coating covers asbestos insulation board reference is made to using a Health and Safety Executive-licensed contractor. Access/preparing the work area, equipment, personal protective equipment, procedures, cleaning and disposal, and clearance procedure are included, together with a safety checklist and cautions. (WSCA Item Number 07/03928)
Section 79 Radiation Curing
MAUGUIERE-GUYONNET F, BURGET D & FOUASSIER J P Role of the photoinitiating systems towards the inhibiting effect of phenolic compounds in the photopolymerisation of acrylates. Progr. Org. Coat. 2007, Vol 59 No 1, 37-45.
Photopolymerisation reactions of wood coatings under ultraviolet and visible light were carried out. The influence of model phenolic derivatives found in wood extractives on the polymerisation kinetics, as well as on the coating properties, of clear coatings formulations exposed to light in laboratory and industrial type conditions is discussed as a function of various UV/visible or visible photoinitiating systems based on ketones and dyes. The properties of suitable formulations are discussed. Several kinds of efficient photoinitiating systems are particularly investigated such as isopropylthioxanthone/amine; bis(acyl)phosphine oxide derivative/isopropylthioxanthone/amine and Rose Bengal/amine/additive. The formulations contained acrylic/urethanes. (WSCA Item Number 07/03958)
A review of the following book also appeared in the June 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
ANON Quantifying energy: BP Statistical Review of World Energy June 2006. BP plc, London 2006, 48 pp. (Available from www.bp.com). (WSCA Item Number 07/04049)
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WSCA Highlights of the Month - May 2007
The May 2007 issue of WSCA contains abstracts of 649 articles
including the following examples:
Section 07 Driers and Minor Additives
SHENOY M A & MARATHE Y D Studies on synergistic effect of ultraviolet absorbers and hindered amine light stabilisers. Pig. Resin Tech. 2007, Vol 36 No 2, 83-9.
Photo-aging of coatings was investigated. Hydroxyl-terminated polyester was synthesised and then cross-linked using isophorone diisocyanate. These clear coats were then stabilised with various additives (a benzotriazole UV absorber and two tetramethylpiperidine-containing hindered amine light stabilisers). The synergistic effect of these additives was also examined. The optical properties of the coatings, such as yellowness, whiteness and gloss of coatings were measured after exposing these coatings to various environments such as cyclic accelerated weathering, direct UV and xenon arc. It was found that coatings stabilised with a combination of additives performed better than the unstabilised coatings as well as single additive coatings. A synergism was observed when using a combination of UV absorbers and hindered amine light stabilisers. By studying the synergy of the additives, their concentrations were optimised to further increase the life of the coatings. (WSCA Item Number 07/02820)
Section 49 Pretreatment and Application
BODINI F Criteria for choosing 'up-to-date' new painting line: a technical solution for high quality results. Verniciatura Industriale 2006, Vol 39 No 461, 431-43.
General principles and criteria for design and layout of a painting plant are discussed. Energy saving, pollution abatement, spray booths, overspray, etc. recycling, transport systems, and health and safety issues are discussed. (In Italian) (WSCA Item Number 07/03068)
Section 53 Weathering, Corrosion, Etc
PETERS C A & OTHERS Ultraviolet light absorber mobility in cross-linked coatings: experiments and modelling. Progr. Org. Coat. 2007, Vol 58 No 4, 272-81.
The diffusion of an ultraviolet absorber across a concentration step change in an acrylic/melamine clear coat was measured by micro-ultraviolet spectroscopy, the ultraviolet absorber being a proprietary benzotriazole compound. Concentration profiles were obtained after diffusion times of 4-200 hours at steady temperatures of 70, 80, and 90 deg. C. The glass transition temperature (Tg) of the coating was measured by dynamic mechanical analysis for each time/temperature pair, and the Tg was observed to increase with thermal ageing, with a faster rate of increase at higher ageing temperatures. The change in Tg was modelled using a first-order dependence on the deviation from a long-time Tg asymptote. The diffusion coefficient was then represented by a free volume expression. The combination provided an accurate model of the measured concentration profiles. The time-dependent increases in Tg helped to explain why ultraviolet absorber diffusion does not alleviate concentration gradients created by photo-oxidation under natural weathering conditions. 15 refs. (WSCA Item Number 07/03104)
Section 55 Fouling and Microbiological Attack
SADASIVAN L, MONTEMAYOR R C & VARNER J N Role of mildewcide in yellow discoloration of latex paints. JCT CoatingsTech 2007, Vol 4 No 3, 42-8.
Significant findings are reported from an examination of more than 300 paint formulations tested with 'all possible' mildewcide options for the effect on yellowing of the paint films exposed to UV light. The investigation showed that the potential of a dry film to yellow is greatest in formulations containing 1,3-dicyano-2,4,5,6-tetrachlorobenzene or 3-iodopropargyl N-n-butylcarbamate (IPBC)-based mildewcides. The data also indicated that the formulation of IPBC-based mildewcide may play a significant role in yellowing. 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one based mildewcides showed the least yellowing. In addition, effects of heat ageing the paints appeared to be negligible compared to formulation effects (coalescent and mildewcide). 13 refs. (WSCA Item Number 07/03129)
Section 63 Paints, Etc for Other Specific Uses
HYDE D M & BRANNON S M Pigmentation research. Polym. Paint Col. J. 2007, Vol 197 No 4510, 46 (6 pp).
Infrared reflection materials are considered after a discussion of sciences regarding solar radiation, black and grey body radiation, emissivity, reflectance, total solar reflectance, light scattering and light absorption, and relevant test methods (heat build-up testing, solar spectral reflectometers, thermal imaging and ultraviolet/visible/near-infrared spectrophotometer). Coatings formulated with infrared pigmentation are designed for application over substrates to improve among other thing, their reflective, emissive and visual attributes. Reducing the energy transferred into a system will reduce the overall equilibrium temperature of the system when all other variables remain constant. When designing an infrared reflective coating or cool coating, one must maximise total solar reflectance, maximise emissivity, and minimise all contamination by infrared absorbing materials. Two cases are included where infrared reflecting pigments are compared to traditional pigments, and three cases relating to thermoset composites. 13 refs. (WSCA Item Number 07/03161)
Section 82 Statistics
KISLOVA Y E & ROMANOV I N Paint industry of Russia: perspective view by 2010. Lakokras. Mat. 2007, No 3, 3 (5 pp).
Statistics are provided relating to the Russian coatings market in 2004, and forecasts to 2010 are provided. The architectural coatings market (30% of the market in 2004), the motor vehicle coatings market (25%) and industrial finishes market (30%) are discussed in detail. (In Russian) (WSCA Item Number 07/03365)
A review of the following book also appeared in the
May 2007 issue of WSCA: full book reviews can be read on the
Library Catalogue page of the PRA web site.
ANON Flooring Industry Yearbook 2007. MPP Ltd, London 2007, 90 pp. Price £9.95.
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WSCA Highlights of the Month - April 2007
The April 2007 issue of WSCA contains abstracts of 700 articles
including the following examples:
Section 01 Pigments, Extenders, Dyestuffs and
Phosphors
BONORA P L, CREAZZI L & TELCH V Characterisation and testing of
photoreactive pigments. Pitture Vernici 2007, Vol 83 No 1,
51-8.
Results on the characterisation and the photocatalytic behaviour of
titanium dioxide nanopowders, and the dispersion of the powders in
coatings matrices, are discussed. The experimental part focussed on the
determination of the photocatalytic efficiency of titanium dioxide in
the decomposition of some organic dyes such as rhodamine and Methylene
Blue. Four different commercial titanium dioxide nanopowders were
evaluated and showed good photocatalytic efficiency of the pure powders.
The same powders were later inserted into two different matrices: a
plaster (lime-based) and a silicate paint. The systems did not show any
improvement in photocatalytic efficiency compared to traditional
micrometric titanium dioxide. Considering that this result was due to an
inadequate dispersion of the nanopowders, some suspensions were prepared
by dispersing the powders in water at different pH values. At quite high
or low pH the zeta potential of the suspension increases and dispersion
quality improves. These suspensions showed an enhancement in rate of
degradation of dyes compared to the pure nanopowders, but after the
integration of the suspensions in the paint the samples did not show any
improvement in photocatalytic activity. (In Italian and English) (WSCA
Item Number 07/02062)
Section 16 Patents: Hydrocarbon Polymers
US SECRETARY OF THE NAVY Limonene, pinene, or other terpenes and
their alcohols, aldehydes and ketones, as polymer solvents for
conducting polymers in aqueous and non-aqueous coating formulations and
their uses. United States Patent 7166664: Off. Gaz. 2007, Vol
1314 No 4.
A coating formulation is disclosed comprising at least one
non-halogenated solvent including terpene(s) or terpenoid(s), and at
least one polymer selected from polydialkylaminophenylenevinylenes.
(WSCA Item Number 07/02177)
Section 53 Weathering, Corrosion, Etc
DE LA FUENTE D & OTHERS Settling of critical levels of soluble
salts for painting. Progr. Org. Coat. 2007, Vol 58 No 1,
23-32.
A variety of accelerated and natural weathering trials were used to
provide realistic series of limits (before application of paints and
related products) of soluble salt depending on the coating systems and
exposure conditions. The coatings were zinc/ethyl silicate primer, a
paint system with zinc-rich epoxy primer with inorganic anticorrosive
pigments, high solids epoxy pigmented with micaceous iron oxide and
acrylic/urethane gloss finish, fusion-bonded epoxy powder, high-solids
epoxy pigmented with micronised glass flake and zinc phosphate, two
paint systems comprising epoxy/polyamide primer pigmented with micaceous
iron oxide and epoxy/polyamide basecoat pigmented with glass flake, and
a system comprising zinc-rich polyurethane primer and polyurethane
basecoat. Chlorides and sulphites were used (seeding blasted surfaces
with various levels of sodium chloride and/or magnesium sulphate then
coating). The results showed that the generalised levels suggested in
the draft version of the ISO standard are far too low compared with the
critical levels obtained from the trials. It is suggested that higher
levels could be defined, which would save costs and time. It was noted
that hot potable water immersion seems to be the most critical
accelerated test for evaluating the effects of soluble salts at the
steel/coating interface. 36 refs. (WSCA Item Number 07/02400)
SCHMELZER J Accuracy of the weathering of paints containing
titanium dioxide pigments: a critical retrospective on twenty years of
weathering. Proc. XXVIII FATIPEC Congress, Budapest (Hungary)
2006, Paper II.B-1, 19 pp.
A critical retrospective examination of accelerated weathering tests of
titanium dioxide-pigmented coatings, evaluated over more than two
decades, is presented which showed that identical coatings led to almost
identical results for the onset of chalking, when assessed in the same
equipment and at the same time. If identical coatings were exposed using
the same accelerated weathering, but at different times of year, the
results deviated from each other by about 400-500 hours. These
deviations were found to be caused by different ambient temperatures in
rooms without air-conditioning. The same effect (500 hours, about 23%)
could be observed on average by changing the black panel temperature
from 60 to 50 deg. C. Deviations between weathering methods of sometimes
markedly more than 800 hours (about 38%) were revealed. In terms of the
formulation of the coatings or their application, everything that causes
different dispersion states was found to have a great influence on the
onset of chalking. A good state of dispersion was normally accompanied
by a high coating gloss. (WSCA Item Number 07/02418)
Section 67 Mechanical and Rheological Properties
KESSEL A & DILGER K Adhesion to coatings. I.
JOT/Oberflaeche 2006, Vol 46 No 9, 56-9.
The use of adhesives on coatings is outlined, with particular reference
to the influence of the curing of the coating on its subsequent adhesive
properties. Examples are provided from the automobile industry where the
adhesive is applied to the vehicle's topcoat. Test methods for
determining the adhesion to the topcoat are outlined. (In German with 12
refs.) (WSCA Item Number 07/02526)
Section 71 Other Properties and Testing Methods
VAN DER VEN L G J & OTHERS Interactions between basecoats and
clear coats in automobile refinish systems. Progr. Org. Coat.
2007, Vol 58 Nos 2/3, 117-21.
The interactions of basecoat/clear coat combinations were investigated
by means of chemical and physical techniques. The effects of a medium
solid clear coat, a volatile organic compound (VOC)-compliant
polyurethane clear coat and ultraviolet-curable clear coat on
interpenetration, physical and paint properties were examined. Scanning
electron microscopy and Fourier transform infrared spectroscopy showed
that the isocyanurate cross-linker in polyurethane clear coats
penetrates to a high extent into the basecoat. The cross-linker was even
detected at the basecoat/substrate interface. The penetration of the
cross-linker in the basecoat/ultraviolet-clear coat was much less;
cross-linker was detected at most a few micrometres into the basecoat.
The reason is the high cure rate of this system which prevents diffusion
of the cross-linker into the basecoat. Stabilisers such as hindered
amine light stabilisers and ultraviolet-absorbers diffuse into the
basecoat as well. (WSCA Item Number 07/02598)
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WSCA Highlights of the Month - March 2007
The March 2007 issue of WSCA contains abstracts of 706 articles
including the following examples:
Section 23 Polymers Containing Silicon and Other
Elements
GRUNLAN M A & OTHERS Minimally adhesive polymer surfaces
prepared from star oligosiloxanes and star
oligofluorosiloxanes. J. Polym. Sci, Polym. Chem. 2006,
Vol A44 No 8, 2551-66.
The effects were investigated of the surface energy, storage modulus,
and glass transition temperature on the biofouling behaviour of siloxane
and fluorosiloxane polymer surfaces (films). Irregular silicon-hydrogen
terminated tetrabranched star oligosiloxanes and star
oligofluorosiloxanes were prepared by the acid-catalysed equilibration
of octamethylcyclotetrasiloxane or
1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane with
tetrakis(dimethylsiloxy)silane, respectively. Terminal epoxy groups were
introduced via platinum-catalysed hydrosilylation with glycidyl allyl
ether to yield compounds that were subsequently cross-linked with
alpha,omega-bis(3-aminopropyl)polydimethylsiloxane. The resulting films
were characterised by goniometry, dynamic mechanical thermal analysis,
and thermogravimetric analysis. The foul-release behaviour was examined
by the measurement of how strongly sporelings (young plants) of the
green seaweed Ulva adhered. Corrosion control for aluminium was
evaluated by electrochemical impedance spectroscopy. Fluorosiloxane
films displayed higher storage modulus and glass transition temperature
values, decreased contact angles (with water), and more effectively
released Ulva sporelings in comparison with siloxane films. 57 refs.
(WSCA Item Number 07/01545)
Section 51 Paint, Etc Removal
GRAPPERHAUS M J & SCHAEFER R B Lead removal with high-intensity
light pulses. Environ. Sci. Tech. 2006, Vol 40 No 24,
7925-9.
An initial investigation was performed into using high-intensity
incoherent light pulses to strip paint. Measurements of light pulse
characteristics, the reflectivity of different paints and initial
experiments on the threshold for paint removal are presented together
with paint removal tests and an approximate model consistent with
experimental results. Paint removal tests included lead paint, the
reduction of lead levels to below levels required for lead abatement,
and air and light emissions measurements (which were within regulatory
guidelines). The tests show that broadband incoherent light pulses may
be effective in removal of lead paint from architectural materials. 10
refs. (WSCA Item Number 07/01675)
Section 55 Fouling and Microbiological Attack
SOMBORN R Why do coatings go off? Farbe Lack 2006,
Vol 112 No 11, 58, (2 pp).
Some of the reasons why water-based coatings may go off once opened, but
prior to application, are described. The dispersion may go off because
the binder is an ideal basis for the growth of bacteria, algae and
fungi. Such microbial attack has various consequences on the subsequent
coating, including changes in colour, pH value and rheological
properties, a destabilisation of the dispersion, production of gases,
and a foul smell. Coatings may go off as a result of failures in
formulation, production, and application. Ways of avoiding the problem
are outlined. (In German) (WSCA Item Number 07/01705)
Section 63 Paints, Etc for Other Specific Uses
MASCARENHAS M Smart coatings: current research and
applications. Surface Coatings Internat. 2007, Vol 90 No
1, 26-31.
A review is presented of types of sensor coatings (thermochromic
coatings, organic compounds, inorganic compounds, polymer
thermochromism, sol/gel thermochromism), stress/strain sensing paints,
pressure-sensitive/barochromic paints, corrosion-sensing paints (colour
change and fluorescent type), self-repair and healing coatings
(microencapsulation, bleeding composites, colloidal aggregation,
nanocomposites, and polyphenylene sulphide coating system),
nanotechnology-based smart coatings (nanocomposites and nanostructuring)
and some smart materials with potential use in paints (self-assembling
materials, stimuli-responsive polymers and shape-memory polymers).
Piezoelectric materials and supramolecular structures are also
mentioned. 23 refs. (WSCA Item Number 07/01740)
Section 69 Analytical Methods
DIETRICH D F & SALTER E Safety management tool for recognition,
evaluation, and control of lead. Internat. Environ. Tech.
2006, Vol 16 No 5, 68.
A colorimetric wipe is discussed that is a complete safety management
tool for lead. It is noted that within one kit are all the materials for
lead-exposed individuals to recognise, evaluate and control lead. The
method for disclosing the presence of lead (US Patent 6,248,593) quickly
and easily detects the presence of lead on skin, including the face, and
surfaces such as tables, shoes, steering wheels, safety glasses, and
windowsills. This is felt to be a significant breakthrough in bringing
lead detection to the worker because previously developed colorimetric
tests for lead are said to be unable to be used safely on skin. (WSCA
Item Number 07/01827)
Section 71 Other Properties and Testing Methods
COSTANZO P J, DEMAREE J D & BEYER F L Controlling dispersion and
migration of particulate additives with block copolymers and Diels-Alder
chemistry. Langmuir 2006, Vol 22 No 24, 10251-7.
Polystyrene and polyethylene glycol, having maleimide and furan end
groups, respectively, were prepared in high yields. They were then
linked by a Diels-Alder addition. A thiol end group on the
styrene/oxyethylene diblock copolymer facilitated covalent bonding to
gold nanoparticles, which were then dispersed into a polyethylene glycol
matrix film. Heating to 9 deg. C dissociated the block copolymer
internal Diels-Alder linkages, with formation of modified,
phase-separated gold particles which then migrated to the film surface.
Longer annealing times enhanced the migration process. In addityion,
adsorption of water into the film depended on the surface concentration
of particles and the matrix polyether molecular weight. 28 refs. (WSCA
Item Number 07/01857)
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WSCA Highlights of the Month - February 2007
The February 2007 issue of WSCA contains abstracts of 653 articles
including the following examples:
Section 01 Pigments, Extenders, Dyestuffs and
Phosphors
HIRANI H, DIGHE A & PATEL C Effective cost saving in
high-performance coating by replacing titanium dioxide with calcium
aluminium silicate and magnesium aluminium silicate. Paintindia
2006, Vol 56 No 10, 75 (9 pp).
Work is presented on the partial replacement of titanium dioxide pigment
with calcium aluminium silicate (CAS) and magnesium aluminium silicate
(MAS) in high-performance coating applications without affecting the
quality of the coating. Mechanical and optical (opacity, whiteness,
gloss and brightness) properties were evaluated for the coatings. The
results revealed that the silicates may be successfully used in the
high-performance coating systems up to a level of 20-25% replacement in
polyurethane primer/surfacer, 15% in floor coating and 20% in roof
coating without affecting the quality of the final paint products. Both
of the fillers may also be used in any other solvent-based or
water-based high-performance coating system and decorative coating with
a replacement of 10-30% of titanium dioxide rutile or anatase depending
on the quality of the product. 12 refs. (WSCA Item Number 07/00708)
Section 02 Patents: Pigments, Extenders, Dyestuffs and
Phosphors
MERCK PATENT GMBH Strongly coloured red effect
pigments. European Patent Application 1681318, 7 pp. (Also US
Patent Application 20060156949).
Intensely coloured red effect pigments are disclosed. They comprise iron
oxide-coated silica flakes, in which the thickness of the effect
pigments is not greater than 500 nm (plus or minus 30 nm). Processes for
the preparation of these pigments are also claimed, in which silica
flakes are coated with iron oxide, where the thicknesses of the silica
flakes and of the iron oxide layers are selected in such a way that the
total thickness of the red effect pigments is not greater than 500 nm
(plus or minus 30 nm). Use of these pigments in cosmetics, paints,
coatings, plastics, films, in security printing, in security features in
documents and identity papers, for colouring seed, for colouring foods
or in medicament coatings and for the preparation of pigment compsns.
and dry preparations are also claimed. (In German) (WSCA Item Number
07/00730)
Section 21 Nitrogenous Polymers
LU R & OTHERS Design and characterisation of modified
urethane lacquer coating. Progr. Org. Coat. 2006, Vol 57 No 3,
215-22.
A commercial polyurethane preparation was blended with natural lacquer
(from raw lacquer collected from a Chinese lacquer tree) and good
results were obtained. The drying times of the natural
lacquer/polyurethane (LPU) blends, especially for obtaining dust-free
dry, were reduced by about 1 hour. The addition of polyurethane greatly
increased the colour and gloss of the blends and also the water and
weather resistances, especially against ultraviolet light. From the
results of pencil lead hardness, rigid pendulum testing, differential
scanning calorimetry, and thermogravimetric analyses, the hardness of
the blended films was also improved compared with polyurethane, as well
as retaining the advantages of natural lacquer. 31 refs. (WSCA Item
Number 07/00819)
Section 65 Optical Properties (Colour, Gloss, Opacity,
Etc)
INDEIKIN E A Particle fineness effect on the optical
efficiency and colour of chromatic pigments. Proc. XXVIII
FATIPEC Congress, Budapest (Hungary) 2006, Paper III.B-1, 7 pp.
A mathematical model is offered for the establishment of the particle
sizes corresponding to maximal optical efficiency of chromatic pigments.
Adequacy of the offered equations is checked for a large number of
pigments. The effect of the particle sizes and their distribution for
many chromatic pigments on their chroma and hue was investigated. A
necessary condition for the synthesis of pigments with high chroma is
management of the crystallisation process with the objective of
synthesising a monodisperse system (with factor of variation no more
than 0.7) and prevention of agglomeration in subsequent manufacturing
stages. 47 refs. (WSCA Item Number 07/01156)
Section 71 Other Properties and Testing Methods
MILLETTE J R Sizing nano-range primary particles in aciniform
carbon aggregates using (public domain Java image processing
program). Microscope 2006, Vol 54 No 2, 51-9.
A simple method for directly sizing aciniform carbon primary particles
found using ASTM D-6602 is described. An image processing program was
used to determine primary particle diameters for several types of
aciniform carbon. The procedure for determining primary particle size
distributions showed good precision between image analysts, and good
accuracy. The image analysts sizing technique may be calibrated and
quality monitored using National Institute of Standards and Technology
(NIST) traceable standard reference spheres. (WSCA Item Number
07/01235)
Reviews of the following books also appeared in the
February 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
MULLER B & POTH U Coatings Formulation. Vincentz
Network GmbH, Hannover 2006, 290 pp. (ISBN 3-87870-177-2). Price 129.00
euros. (WSCA Item Number 07/01354)
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WSCA Highlights of the Month - January 2007
The January 2007 issue of WSCA contains abstracts of 701 articles including the following examples:
Section 53 Weathering, Corrosion, Etc
KATAOKA, Y, KIGUCHI M, WILLIAMS R S & EVANS P D Effects of wavelength on photodegradation depth profiles in Japanese cedar (Cryptomeria japonica D. Don) earlywood. Proc. PRA 5th International Woodcoatings Congress 'Enhancing Service Life', Prague (Czech Republic) 2006, Paper 9, 11 pp.
Fourier transfer infrared microscopy (FTIR) was used to depth profile the photodegradation of Japanese cedar earlywood exposed to monochromatic light in the ultraviolet and visible ranges (band pass 20 nm, average wavelengths 246, 278, 310, 341, 372, 403, 434, 465 or 496). Parallel experiments assessed the transmission of light through thin sections of Japanese cedar. The depth of photodegradation increased with wavelength up to and including the violet region of the spectrum, but decreased in the blue region. Penetration of light into Japanese cedar was positively correlated with wavelength. It was concluded that violet light has sufficient energy to degrade wood and extends photodegradation into wood beyond the zone affected by ultraviolet radiation. It is considered that surface treatment designed to protect wood used outdoors should protect wood from the effects of violet light. 22 refs. (WSCA Item Number 07/00310)
STENZEL V, MOCK U & TILLNER S Do-it-yourself repairs. Europ. Coatings J. 2006, No 11, 32-6.
Several self-repair systems for heavy-duty and anticorrosive applications based on the use of encapsulated materials which will polymerise when the capsules are ruptured are demonstrated. Hollow fibres containing repair materials were similarly used in composites. To avoid the risk of the healing compounds becoming depleted over time, a system was developed in which it is stored in a connected series of channels. 11 refs. (WSCA Item Number 07/00321)
Section 55 Fouling and Microbiological Attack
YEBRA D M, KIIL S, WEINELL C E & DAM-JOHANSEN K Effects of marine microbial biofilms on the biocide release rate from antifouling paints: a model-based analysis. Progr. Org. Coat. 2006, Vol 57 No 1, 56-66.
An antifouling paint model and a simplified biofilm growth model were used to provide a reaction engineering-based insight to the effects of marine microbial slimes on biocide leaching and, to a minor extent, polishing behaviour of antifouling paints. It was concluded that the perturbation of the local sea water conditions (e.g, pH), as a consequence of the metabolic activity of the biofilm should not affect the net biocide leaching and binder reaction rates significantly. This results from the thin and poorly active biofilms which presumably grow on highly effective modern antifouling paints. According to simulations, the experimental decrease in the biocide leaching rate caused by biofilm growth must be mainly attributed to adsorption of the biocide by the exopolymeric substances secreted by the micro-organisms. Simulation of experimental results from the literature for tributyltin chloride and copper(II) were attempted. 58 refs. (WSCA Item Number 07/00352)
Section 56 Patents: Fouling and Microbiological Attack
AXIMED AS Capsaicin derivates and the production and use thereof. European Patent Application 1670310, 35 pp. (Also PCT WO 2005/025314).
New compounds comprising capsaicin derivatives are disclosed, together with a new method for their production, and their use as microorganism-repellent agents in paints and coatings, in particular for marine installations and ships, but also for land-based structures. The method of production involves conversion of a carboxylic acid (derivative) with a vanillylamine to produce a capsaicin derivative. (WSCA Item Number 07/00354)
BIOLOCUS AS Self-polishing antifouling coating compositions comprising an enzyme. World (PCT) Patent Application 2006/002630, 94 pp.
Self-polishing antifouling coating compositions comprising an enzyme are disclosed, together with methods for their production and their uses. The coating composition may comprise, e.g, a pigment in which case the coating compsn. may be used as a painting compsn. In a first aspect, the invention relates to a self-polishing antifouling coating compsn. comprising a first enzyme having antifouling activity, and at least one hydrolysable polymer compsn. capable of being non-enzymatically hydrolysed in an aqueous environment. In a further aspect there is provided a self-polishing antifouling coating composition comprising a first enzyme having anti-fouling activity, a second enzyme having polymer-hydrolysing activity, and at least one hydrolysable polymer composition capable of being hydrolysed by said second enzyme. In the latter case, the first enzyme preferably does not contribute to the self-polishing effect. The second enzyme typically does not have a direct antifouling action. (WSCA Item Number 07/00355)
Reviews of the following books also appeared in the
January 2007 issue of WSCA: the full book reviews can be read on the
Library Catalogue page of the PRA web site.
HARLOW M (EDITOR) UK Surface Coatings Handbook 2006/2007. Oil & Colour Chemists' Association, Wembley 2006, 216 pp. (ISBN 0-903809-35-4). Price £75.00, £75.00 (subscribers to Surface Coatings Internat.), and free with membership to Oil & Colour Chemists' Association. (Also available on the Internet).
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