Recent Highlights

Section 49 Pretreatment and Application

ANON Next generation electrocoating. Finishing 2009, Vol 33 No 6, 28 (2 pp).

The way in which automotive original-equipment-manufacture (OEM) benefits from fast and accurate electrocoating simulation is examined. A recent electrocoating simulation solution that is an addition to a lineup of software tools for a variety of electrochemical processes is introduced. The simulation of a moving automobile body in real time throughout the electrocoating tank is enabled. Both macro- and meso-scale simulations enable the performance analysis of the actual electrocoating process for a given body-in-white program. (WSCA Item Number 10/00964)

Section 63 Paints, Etc for Other Specific Uses

CHAWAN D L Paramagnetic coatings. Paintindia 2009, Vol 59 No 10, 97-100.

Paramagnetic coatings were developed that are based on a special polymer embedded with superparamagnetic materials such as iron oxide particles or other paramagnetic ions. The orientation of nanoscale crystalline particles of iron oxide was controlled using a low grade magnetic field, which was used to affect the spacing of the colloidal crystals and thereby control their ability to reflect light and change colour. An application would be in colour-changing motor vehicle paints. The coatings also find applications in the medical field such as medical devices to make them visible inside the body with magnetic resonance imaging, electron paramagnetic resonance oximetry for measuring oxygen concentration in tissues, and pain relief compositions. 17 refs. (WSCA Item Number 10/01085)

Section 75 Pollution and Utilisation of Wastes

EDWARDS R D & OTHERS Nitrogen dioxide and ozone as factors in the availability of lead from lead-based paints. Environ. Sci. Tech. 2009, Vol 43 No 22, 8516-21.

It is shown that exposure to nitrogen dioxide and ozone increased the lead in wipe samples of stainless steel surfaces painted with alkyd low gloss solvent lead-based paint by about 300% and 37% respectively, with corresponding changes in surface morphology indicated by reflectometry and scanning electron microscopy. Lead release from unexposed low gloss acrylic household paints was 40 times greater than comparable solvent-based paints. Given that lead-based paint is still manufactured and used in many urban areas of the developing world where ozone concentrations currently exceed historic US concentrations, the interaction of air pollution with lead-painted indoor surfaces may pose greater exposure risks for lead poisoning in children than previously anticipated. 33 refs. (WSCA Item Number 10/01221)

Section 87 Legislation and Other Official Publications

ERICKSON B E Nano-silver pesticides. Chem. Eng. News 2009, Vol 87 No 48, 25-6.

The activities of the US Environmental Protection Agency in relation to nanoscale silver particles are discussed. It is noted that antimicrobials are considered as pesticides and fall under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The EPA has to determine what data it needs to assess potential environmental, health and safety risks, and to decide the best ways to obtain the data. Under the Act the EPA has authority to require manufacturers to provide whatever data it deems necessary. The findings of a four day meeting of the FIFRA scientific advisory panel are discussed, which considered whether data for non-nanoscale forms of silver should be allowed to substitute for data for nano-silver and whether data for one nano-silver product may be allowed to substitute for data for another product. The EPA is considering three main approaches, the first being to evaluate industry's claim that there is limited exposure potential, the second focusing on metabolism studies, and the third treating nano-silver particles as new active ingredients. Several existing and proposed nanosilver products are described. (WSCA Item Number 10/01354)

Books

Reviews of the following books also appeared in the February 2010 issue of WSCA:

CHERN C-S Principles and Applications of Emulsion Polymerisation. John Wiley & Sons Inc, Hoboken (New Jersey) 2008, 252 pp. (ISBN 978-0-470-12431-4). Price £83.50, 104.20 euros. (WSCA Item Number 10/01364)

DIETRICH R Paint Analysis. Vincentz Network, Hannover 2009, 138 pp. (ISBN 978-3-86630-912-8). Price 129.00 euros. (WSCA Item Number 10/01365)

DURR S & THOMASON J C Biofouling. Wiley-Blackwell, Chichester 2010, 429 pp. (ISBN 978-1-4051-6926-4). Price £120.00, 138.00 euros. (WSCA Item Number 10/01366)

HANSEN C M Hansen Solubility Parameters. A User's Handbook. Second Edition. CRC Press, Boca Raton (Florida) 2007, 544 pp. (ISBN 978-0-8493-7248-3). Price $164.95. (WSCA Item Number 10/01367)

IBACH H Physics of Surfaces and Interfaces. Springer-Verlag, Berlin & Heidelberg 2006, 646 pp. (ISBN 978-3-540-34709-5). Price £76.50. (WSCA Item Number 10/01368)

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

CARDINAL C M, FRANCIS L F & SCRIVEN L E Drying and collapse of hollow latex. J. Coatings Tech. Res. 2009, Vol 6 No 4, 457-69.

Cryogenic scanning electron microscopy (cryoSEM) was used to characterise the microstructure of coatings containing hollow latex (polystyrene) particles during drying. Images suggest that latex voids empty after air invades into the coating interstitial space and collapse occurs late in the drying process. High drying temperature, high humidity, and low binder (polyvinyl acetate) concentrations promoted collapse. For hollow latex particles with porous shell walls, temperature and humidity had little effect, whereas the incorporation of polyvinyl acetate binder increased collapse. It was proposed that during drying, diffusion of water from the particle creates a vacuum inside the latex. The vacuum is either relieved by nucleation of a gas bubble from the dissolved air in the water-filled particle or it causes the particle to collapse by buckling. Some recommendations are made for future design of hollow particles. 43 refs. (WSCA Item Number 10/00003)

Section 07 Driers and Minor Additives

PLOEGER R, SCALARONE D & CHIANTORE O Thermal analytical study of the oxidative stability of artists' alkyd paints. Polym. Deg. & Stabil. 2009, Vol 94 No 11, 2036-41.

Thermal analyses, specifically differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), were used to investigate changes in the properties of artists' alkyd paint films with age. The cross-linking rate during accelerated photo-ageing was observed with DSC by monitoring the exothermic reaction after the decomposition of peroxide groups, which form during autooxidation of the alkyd resin. The investigation of naturally-aged films, some up to 28 years, revealed an increase in the glass transition temperature with age. TGA of naturally aged films indicated an increase in film density with age, probably due to cross-linking at first and then the possible formation of oxidative degradation products over time, such as carboxylate salts. 16 refs. (WSCA Item Number 10/00080)

Section 35 Water-borne Paints and their Components

SWARTZ A Synergistic water-borne acrylic urethane systems. Proc. European Coatings Conf. 'High Performance Water-borne Clear Coats II', Berlin (Germany) 2009, 13-25.

A new strategy utilising a combination of acrylic and polyurethane dispersions (PUDs) is presented to advance the balance of volatile organic compound (VOC), minimum film-forming temperature (MFFT) and hardness related properties for industrial and decorative coatings. Thus, addition of a low glass transition temperature (Tg) of less than minus 5 deg. C, specially designed diffusion polymer (I), to a high Tg of greater than plus 20 deg. C polymer (II) at or above the percolation threshold, is able to form a pathway for selected coalescent to escape from the polymer (II) dominant phase. This enhances film formation, reduces VOCs and accelerates the development of hardness and hardness-related properties such as block resistance. In the wet state, the coalescent preferably partitions in the hard dominant phase, where it is needed for the plasticisation of this phase. As the film formation continues, the bulk of the water is lost. This triggers a change in the solubility of the coalescent in the two polymers. The coalescent now prefers the designed diffusion polymer and migrates out of the dominant phase polymer into the designed diffusion polymer. The latter polymer release coalescent at a much faster rate than the dominant phase polymer does. It was found that both polyurethane dispersion and acrylic polymers may be made to function as designed diffusion polymers (I). This polymer should be slightly more hydrophilic than the dominant phase polymer (I), since this allows the coalescent to be more selectively partitioned into the high Tg polymer (II) phase, and film formation and water evaporation triggers the acceleration of removal of the coalescent from the polymer (I) phase. 14 refs. (WSCA Item Number 10/00169)

Section 53 Weathering, Corrosion, Etc

DICKENS B Model-free estimation of outdoor performance of a model epoxy coating system using accelerated test laboratory data. J. Coatings Tech. Res. 2009, Vol 6 No 4, 419-28.

Linkage between laboratory and field exposure results for a model epoxy coating system was established using a model-free heuristic approach for both dose and a total effective dosage model. The approach assumes that the exposure results conform to the additivity law and the reciprocity law. These assumptions were shown to be valid by the experimental results and the successful linkage of indoor and outdoor exposures. Outdoor performance of the epoxy material could be predicted using dose for any environment where the appropriate weather data (temperature, relative humidity and solar spectrum) are available at small intervals (a few minutes) of time. Further materials made at different times may be subjected to the same temperature/relative humidity/solar test environment once their SPHERE (simulated photodegradation of high energy radiant exposures) degradation data are available. (WSCA Item Number 10/00314)

Books

Reviews of the following books also appeared in the January 2010 issue of WSCA:

CARR D (Editor) ENDS Directory 2010. Haymarket Professional, London 2009, 136 pp. (ISBN 0-907673-23-6). Price £65.00. (WSCA Item Number 10/00697)

HARLOW M (EDITOR) UK Surface Coatings Handbook Oil & Colour Chemists' Association, Wembley 2009, 152 pp. (ISBN 0-903809-38-9). (WSCA Item Number 10/00698)

HEILIG M Deutsches Taschenbuch fur Maler und Lackierer 2010 (German Handbook for Painters 2010). 2 volumes. Verlag Georg D W Callwey, Munchen 2009, 291 and 124 pp. (ISBN 978-3-7667-1820-4). Price 15 euros. (WSCA Item Number 10/00699)

WELDON D G Failure Analysis of Paints and Coatings. Revised Edition. John Wiley & Sons, Chichester 2009, 362 pp. (ISBN 978-0-470-69753-5). Price £95.00, 109.30 euros. (WSCA Item Number 10/00700)

Section 02 Patents: Pigments, Extenders, Dyestuffs and Phosphors

SHEPHERD COLOR CO Non-chromate corrosion inhibitor formulas based on permanganate sodalite compositions. United States Patent Application 20090075113, 4 pp. (Also PCT WO 2009/039094).

A crystalline sodalite-permanganate material suitable for uses as an anticorrosive pigment is disclosed. The sodalite (aluminosilicate) is synthesised in the presence of a stoichiometric quantity of permanganate ion. After thorough washing to remove trace salts the resulting pigment may be encapsulated with amorphous silica. The resulting pigment has enhanced acid stability and provides good corrosion resistance on reactive metal substrates such as aerospace aluminium or coil grade hot-dip galvanised steel. The pigment is useful as a replacement for chromium-based pigments, such as strontium chromate pigments. (WSCA Item Number 09/06406)

Section 53 Weathering, Corrosion, Etc

RAMEZANZADEH B, MOHSENI M, YARI H & SABBAGHIAN S Evaluation of an motor vehicle clear coat performance exposed to bird droppings under different testing approaches. Progr. Org. Coat. 2009, Vol 66 No 2, 149-60.

The effects were investigated of natural bird droppings and pancreatin on the properties of an motor vehicle acrylic/melamine clear coat. Two different testing approaches were used, with ageing (climate cabinet, etc) either before or after contacting with the agents. The effects of the biological materials were investigated by digital camera, scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and a gloss meter. In addition, the mechanical properties of clear coats were evaluated and Fourier transform infrared spectroscopy (FTIR) analysis was utilised to gain an understanding of the failure mechanism. The biological materials had an extremely vital effect on the appearance of the coatings. A decrease of glass transition temperature and hardness of the films made by pancreatin and bird droppings were observed and were attributed to the chemical alterations as proved by FTIR analysis. It was also found that the biological degradation occurring on the samples experiencing the post-aged testing method was more severe than in the samples exposed to pre-aged testing. Although bird droppings and pancreatin revealed a same failure mechanism, the effect of the former was more severe. It was also shown that the enzymatic structure of biological materials is responsible for catalysing the hydrolytic degradation of the clear coat at neutral pH. It was concluded that the biological degradation mechanism may be regarded as an enzymatically induced hydrolytic cleavage. 14 refs.

Section 55 Fouling and Microbiological Attack

WALES M & McDANIEL S Putting nature's mean, green fighting machines to work in coatings. Proc. European Coatings Conf. 'Novel Biocide Technology IV', Berlin 2009, 73 (39 pp).

Mechanisms, activity results against bacteria, fungi, algae and viruses, synergism and testing of a particular additive in a clear styrene/acrylic latex coating are discussed, etc. Antimicrobial peptides as additives are concluded to offer substantial advantages over the traditional biocidal/biostatic chemicals presently used in coatings. They are biodegradable, work under mild conditions, provide safe alternatives to existing pesticides, and are not associated with the production or release of hazardous compounds to the environment. The diversity of antimicrobial peptides identified in nature provides a variety of design templates for tailoring a new generation of environmentally friendly antimicrobial additives for a wide variety of coatings. Combinatorial libraries of antimicrobial peptides provide a wealth of candidate biocides adaptable to specific coating requirements. Photographs illustrate the mode of action of antimicrobial peptides and the specific types that may be used. 18 refs. (WSCA Item Number 09/06725)

Section 71 Other Properties and Testing Methods

TOURKINE P, LE MERRER M & QUERE D Delayed freezing on water-repellent materials. Langmuir 2009, Vol 25 No 13, 7214-6.

The presence of a significant volume of air in a micro-textured superhydrophobic interface is shown to induce a marked delay in freezing of water, when depositing water on cold solids. A slight tilting enabled run-off of the unfrozen droplets without their accumulation on the substrate, as demonstrated for a copper substrate. 15 refs. (WSCA Item Number 09/06881)

Section 79 Radiation Curing

PIETSCHMANN N & LEHMANN H Formulation and application tests into ultraviolet-curable electrodeposition coatings. Proc. RadTech Europe 2009 'UV/EB Sustainable Technology', Nice (France) 2009, Paper, 10 pp. (Available on CD-ROM).

Aqueous formulations for electrodipping coatings were prepared from commercially-available raw materials which are intended for other kinds of application. The binder types, photoinitiators, ways of formulation, and electrodeposition as well as pre-drying and UV curing conditions were varied. A fraction of the formulations tested could be applied on panels operated as cathode or as anode. However, their application condition differed considerably from those of conventional electrodipping paints. This was related to lower voltages and to constant or almost constant currents. Many systems failed due to low stability, irregular film formation, or inconsistent substrate adhesion. Thus, no cataphoretic formulation remained for further optimisation steps, however, some anaphoretically depositable systems performed well. The incorporation of carbon black provided only low advantages but pronounced drawbacks. 21 refs.

Books

Reviews of the following books also appeared in the December 2009 issue of WSCA:

DREW R, FRANGOS J & HAGEN H Engineered Nanomaterials: A Review of the Toxicology and Health Hazards. Safe Work Australia, 2009, 163 pp. (ISBN-978-0-642-32922-6, available at www.safeworkaustralia.gov.au). (WSCA Item Number 09/07065)

JACKSON N, LOPATA A, ELMS T & WRIGHT P Engineered Nanomaterials: Evidence of the Effectiveness of Workplace Controls to Prevent Exposure. Safe Work Australia, 2009, 75 pp. (ISBN 978-0-642-32884-7, available at www.safeworkaustralia.gov.au). (WSCA Item Number 09/07066)

NORTHEAST WASTE MANAGEMENT OFFICIALS' ASSOCIATION & ILLINOIS WASTE MANAGEMENT & RESEARCH CENTER Printing Industry Pollution Prevention Notebook. 2009 . (Available at http://www.istc.illinois.edu/info/library_docs/manuals/printing/toc.htm) (WSCA Item Number 09/07067)

NORTHEAST WASTE MANAGEMENT OFFICIALS' ASSOCIATION & ILLINOIS WASTE MANAGEMENT & RESEARCH CENTER Metal Painting and Coating Pollution Prevention Notebook. 2009 . (Available at http://www.istc.illinois.edu/info/library_docs/manuals/coatings/toc.htm) (WSCA Item Number 09/07068)

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

YUN K M & OTHERS New physical route to produce monodispersed, microsphere nanoparticle/polymer composites. Langmuir 2009, Vol 25 No 18, 11038-42.

Combination of milling, using zirconium dioxide beads, with electrospraying, yielded non-agglomerated, monodispersed, microspherical composites of titanium dioxide nanoparticles within a polymethyl methacrylate matrix. Increase in the oxide concentration resulted in smaller particles and their uniform distribution. Such composites are known to display ultrafast optical non-linearity, while the matrix polymer is transparent and absorbs ultraviolet light. 20 refs. (WSCA Item Number 09/05757)

Section 53 Weathering, Corrosion, Etc

CHEN X, LI X G, DU C W & CHENG Y F Effect of cathodic protection on corrosion of pipeline steel under disbonded coating. Corros. Sci. 2009, Vol 51 No 9, 2242-5.

A test rig was developed to investigate the effect of cathodic protection (CP) on the corrosion of pipeline steel in the crevice area under disbonded coating through the measurements of local potential, solution pH and dissolved oxygen concentration. The results demonstrated that, in the early stage of corrosion of steel, cathodic protection is unable to reach the crevice bottom to protect steel from corrosion due to the geometrical limitation. Corrosion of steel occurs preferentially inside the crevice due to a separation of the anodic and cathodic reactions with the depletion of dissolved oxygen in the crevice solution. The main role of cathodic protection in the mitigation of the sequential corrosion of steel in the crevice under the disbonded coating is to enhance the local solution alkalinity. With the increase in distance from the open holiday, a high cathodic polarisation is required to achieve appropriate cathodic protection level at the crevice bottom. A potential difference always exists between the open holiday area and inside the crevice, reducing the cathodic protection effectiveness. 23 refs. (WSCA Item Number 09/06047)

Section 54 Patents: Weathering, Corrosion, Etc

SHEFFIELD HALLAM UNIVERSITY Biological functionalisation of a sol/gel coating for the mitigation of biofouling microbial-induced corrosion. World (PCT) Patent Application 20(WSCA Item Number 09/030959, 43 pp. (Also British Patent Application 2452552).

A method of preparing a substrate using a sol/gel derived coating incorporating a micro-organism is disclosed. The coating is configured to inhibit microbial-induced corrosion (MIC) and/or biofouling at the substrate/coating interface. The coating is prepared by mixing a sol comprising an inorganic oxide particulate with a suspension comprising the micro-organism, applying the mixture on to a substrate followed by curing such that the resultant coating is chemically bonded to the substrate. (WSCA Item Number 09/06075)

Section 69 Analytical Methods

ZHANG W, SMITH R & LOWE C Confocal Raman microscopy study of the melamine distribution in polyester/melamine coil coatings. J. Coatings Tech. Res. 2009, Vol 6 No 3, 315-28.

Confocal Raman spectroscopy (CRM) was used to characterise the melamine distribution in three polyester/melamine paint systems, one clear and two pigmented coil coatings. Both the surface mapping and depth profiling features of confocal Raman spectroscopy were used to perform a three-dimensional analysis. The depth profiling of the clear coating was performed in a non-destructive way, but due to the opaque nature of the pigments, cross-sections of the pigmented coatings were prepared in order to facilitate the analysis of the melamine distribution through the film thickness. Melamine-enriched zones were found on the surfaces of all three samples. They appeared to be spherical with diameters of around 5 micrometres. It was also observed from the cross-sections that the melamine-enriched zones appeared as 'particles' distributed randomly through the coating. The Raman spectra collected at these regions showed significantly higher triazine ring band intensity. 16 refs. (WSCA Item Number 09/06182)

Section 73 Industrial and Other Hazards

REIJNDERS L Release of titanium dioxide and silica nanoparticles from nanocomposites. Polym. Deg. & Stabil. 2009, Vol 94 No 5, 873-6.

In the light of the growing interest in the development of nanocomposites consisting of organic polymers and titanium dioxide or amorphous silicon dioxide nanoparticles, the hazardous nature of these nanoparticles and the options for hazard reduction are discussed. These nanoparticles may be released from nanocomposites. Thus, in the design of nanocomposites with such nanoparticles, hazard reduction extending to the full nanocomposite life cycle would seem a matter to consider. Options for hazard reduction include changes of nanoparticle surface, structure or composition, better fixation of nanoparticles in nanocomposites, including persistent suppression of oxidative damage to polymers by nanoparticles, and design changes resulting in the release of relatively large particles. 82 refs. (WSCA Item Number 09/06242)

Section 73 Industrial and Other Hazards

ANON Nanoparticle exposure and risk. NanoPerspective 2009, March, 6.

A nanomaterials safety, health and the environment (SHE) accreditation scheme is discussed that is applicable to all organisations producing nanomaterials and nano-enabled products, together with users of nanotechnology in general. The scheme promotes the responsible and proactive application of good safety, health and environmental practice within the nanomaterials and nanotechnology community. In this article, identifying and assessing the hazards of using nanomaterials are discussed. Use of published literature, including material safety data sheets, is considered. Where no substance-specific data are available, a qualitative assessment should be made based upon the available reliable data, which may involve comparison with analogous materials. The information identified in the hazard assessment should be used to develop exposure scenarios. The information that should be documented in developing these scenarios is listed. (WSCA Item Number 09/06236)

Books

Reviews of the following books also appeared in the November 2009 issue of WSCA:

HEILEN W Additives for Waterborne Coatings. Vincentz Network, Hannover 2009, 222 pp. (ISBN 978-3-86630-850-3). Price 139.00 euros. (WSCA Item Number 09/06365)

TYLER S (EDITOR) Polymers Paint Colour Journal (PPCJ) Yearbook 2010. DMG World Media (UK) Ltd, Redhill (Surrey) 2009, 230 pp. (ISBN 1-84313-060-2). Price £168.00 (UK), £176.00 (elsewhere). (WSCA Item Number 09/06366)

WINKELAAR A Coatings Basics. Vincentz Network, Hannover 2009, 152 pp. (ISBN 978-3-86630-851-0). Price 79.00 euros. (WSCA Item Number 09/06367)

Section 02 Patents: Pigments, Extenders, Dyestuffs and Phosphors

CLARIANT INTERNATIONAL LTD Aqueous pigment preparations having non-ionic additives on the basis of allyl and vinyl ether. World (PCT) Patent Application 2009/024233, 41 pp.

Aqueous pigment preparations are disclosed, which contain at least one organic and/or inorganic pigment, (B) a dispersing agent (I) selected from one or a mixture of compounds of specified general formulae, optionally a wetting agent, optionally further surfactants and/or dispersing agents, optionally one or multiple organic solvents, or one or multiple hydrotropic substances, optionally further additives common for the production of aqueous pigment dispersions, and water. The dispersants (I) are specific non-ionic copolymers which may be produced using macromonomers from polyethylene glycol/polypropylene glycol monovinyl ethers or allyl ethers. (In German) (WSCA Item Number 09/05133)