World Surface Coatings Abstracts (WSCA) - Highlights

January · February · March · April · May · June · July · August · September · October · November

Highlights of the Month - December 2003

The December 2003 issue contains abstracts of 802 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

CIULLO P A & ROBINSON S: Kaolin clay: functional optical additives. (Paint & Coatings Ind. (US) 2003, Vol 19 No 8, 42 (5 pp).)
The structure, types, properties, and applications of kaolin clay are described. Emphasis is given to the use of these clays as optical additives. Kaolin is the common name for the mineral products comprised totally or substantially of the aluminium silicate clay mineral kaolinite. Most of the clay used by the coatings industry is water-washed to remove mineral impurities. Kaolin clays are offered in more varieties than other silicate functional fillers in order to provide a range of particle crystallinity and shapes, controlled particle size fractions, brightness and opacification. These grades are made even more versatile through chemical modification. Grades are available with dispersant coatings for easy dispersion in water, as well as stearate or silane surface treatment for improved compatibility with organic matrices. The primary use of kaolin in coatings is as a titanium dioxide extender in water-borne architectural paints. Calcined clays generally provide the best brightness, titanium dioxide extension and dry hide. Water-washed and delaminated grades also contribute to extension and dry-hide, as well as covering power and gloss control. (WSCA Item Number 03/08214)

Section 07 Driers and Minor Additives

SAUER F: New approach to the understanding of rheological additives. (Proc. PRA 7th Nurnberg Congress 'Creative Advances in Coatings Technology' (PRA, Teddington/Vincentz Verlag, Hannover), Nurnberg 2003, Vol I, 145-59.)
Rheological additives which play a major role in the storage and application properties of liquid systems are discussed. Non-associative rheological additives and associative thickeners are considered together with several aspects of using associative thickeners in aqueous systems. The structure and rheological effectiveness of associative thickeners are examined as well as the reversible formation of networks through micelles and hydrophobic segments. 12 refs. (WSCA Item Number 03/08279)

Section 09 Natural Resins

ANON: Shellac is back. (Surface Coatings Austral. 2003, Vol 40 No 9, 15.)
An increase in use of shellac is noted. Consumers demanding more natural products are reported to be showing interest in shellac, furniture restorers are using it in preference to polyurethanes, and the low toxicity of shellac makes it suitable for use in food contact applications and for toys. Production and types are briefly discussed. (WSCA Item Number 03/08298)

DEMASI V: Advantages of shellac. III. (Am. Painting Contractor 2003, Vol 80 No 8, 18 (3 pp).)
Various applications of shellac are discussed. The use of alcohol in the removal of shellac, and the decoration of a light coloured wood-panelled room by the application and removal of wood stain glazes, is described. The use of shellac products as a superior ground, or basecoat, for the application of glazes is considered together with the creation of painted floors as imitations of marble or inlaid wood. The marketing of painted finishes, including those of decorated glass Christmas balls sprayed with shellac and then marbleised, is also discussed. (WSCA Item Number 03/08299)

Section 30 Patents: Cellulose Products

TOPPAN PRINTING CO: Coating agent. ( Japanese Unexamined Patent 2002/348522.)
The agent is produced from environmentally-friendly natural resources and is waste-treatable or recyclable inexpensively. The coatings have good gas barrier properties and inhibit moisture deterioration. The agent comprises very fine cellulose having as constituent units glucuronic acid residues and glucose residues that are formed by oxidising cellulose so that the carbon atom in the 6-position on the glucopyranose ring is selectively converted to a carboxy group. (WSCA Item Number 03/08419)

For further information on WSCA please contact the Editor Dr Norman Morgan

top

Highlights of the Month - November 2003

The November 2003 issue contains abstracts of 630 articles including the following examples on "titanium dioxide":

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

MAXIM C, PICA A & EPURE C: Optimisation of the selection process for titanium dioxide and titanium dioxide substitutes used in motor vehicle products. (Pitture Vernici 2003, Vol 79 No 9, 19-26.)
The results of a comparative study on the selection of pigments in the manufacture of alkyd-forming products are presented. Colour analysis (including systems subjected to ultraviolet exposure), emission spectrography, differential thermal analysis and gloss measurement were used to characterise products with the various titanium dioxide types and substitute pigments. (In Italian and English) (WSCA Item Number 03/07588)

Section 02 Patents: Pigments, Extenders, Dyestuffs and Phosphors

SUMITOMO CHEMICAL CO: Titanium hydroxide, photocatalyst obtainable from the same and coating agent comprising the same. ( United States Patent Application 20020132734, 10 pp. (Also European Patent Application 1,219,569).)
Photocatalyst and photocatalytic coatings with improved activity on irradiation with visible light are disclosed. A titanium hydroxide having primary differential spectrum as specified is claimed, as is titanium hydroxide containing 0.02-30 wt. % sulphur compound. Coating agent comprising titanium hydroxide and a solvent, photocatalyst obtained by calcining titanium hydroxide, and process for obtaining photocatalyst are also claimed. (WSCA Item Number 03/07606)

Section 07 Driers and Minor Additives

NISHIYAMA K & OTHERS: Nanoatomisation of titanium diboride using ordered mixture and metallothermic reaction methods. (Surface Coatings Internat. Coatings Trans. 2003, Vol 86 No B3, 169-74.)
The effects were investigated of the ordered mixture and metallothermic reaction methods for the preparation of titanium diboride on the atomisation of the boride in its production process using titanium dioxide contained in waste paints as the starting material. The metallothermic reaction method allowed the production of highly pure titanium diboride even when titanium dioxide recovered from the waste paints was used, instead of pure titanium oxide. The results of scanning electron microscopy (SEM), transmission electron microscopy (transmission EM) and X-ray diffraction (XRD) showed that the titanium diboride particles obtained were hexagonal plate-like nanoparticles. The ordered mixture method when adopted in the mixing process of starting powders improved the atomisation of titanium diboride and the reaction efficiency in the purifying process. Titanium diboride paint film strength tests with an ultramicrohardness meter revealed that titanium diboride produced from recovered titanium dioxide considerably strengthened the paint film as pure titanium dioxide does. The metallothermic method involves titanium dioxide, boric oxide, magnesium and, as a negative catalyst, magnesium oxide. 15 refs. (WSCA Item Number 03/07623)

Section 17 Oxygenated Polymers

GUSTAFSSON J, NORDENSWAN E & ROSENHOLM J B: Consolidation behaviour in sedimentation of titanium dioxide suspensions in the presence of electrolytes. (J. Colloid Interface Sci. 2003, Vol 258 No 2, 235-43.)
The consolidation of titanium dioxide suspensions due to gravity sedimentation in the presence of electrolytes was investigated as a function of pH. The particle interaction was related to the zeta potential and the thickness of the electrical double layer, by utilising the repulsive barrier in the classical Deryagin/Landau/Verwey/Overbeek (DLVO) theory. The stability of the suspensions was represented as the average final solids content in the sediment cake. The batch sedimentation process was followed by scanning the sample cell with X-rays, from which the solids content and the particle size were calculated. Generally, dense sediments, with average final solids content up to volume fractions of 0.5, were found for stable suspensions. The interpretation of average final solids content as a function of the repulsive barrier also made it possible to distinguish between the adsorption mechanisms of ions from solution. Addition of electrolyte at a fixed low and high pH clearly showed the specificity in adsorption of, and consequent flocculation by, the barium ion from the indifferent nitrate. Sodium was, however, again observed to flocculate the titanium dioxide suspensions slightly more strongly than nitrate. 58 refs. (WSCA Item Number 03/07648)

Section 56 Patents: Fouling and Microbiological Attack

RECKITT BENCKISER (UK) LTD: Photocatalytic compositions and methods. ( United States Patent Application 20020040723, 25 pp. (Also European Patent Application 1,246,897).)
Photocatalytic cleaning and sanitising compositions are disclosed which are effective against soiling and odours. They contain photocatalytic material or precursor with sensitiser which absorbs visible, UV or IR radiation. Specific claims refer to titanium dioxide of specified particle size, use of 0.000001-1 wt. % sensitiser, and use in form of liquid compsn. also containing surfactant(s) and other components. (WSCA Item Number 03/07861)

Section 82 Statistics

EDWARDS E: Titanium dioxide: graceful maturation or spirited rejuvenation. (Mineral Pricewatch 2003, March, 7-11.)
Prospects for the titanium dioxide industry are discussed. It is noted that in recent years the ownership of the industry had changed completely, from diversified chemical industry businesses to specialised companies. The value of the market is estimated at $8 billion. Demand growth for the next decade is forecast at 2.5-3% per annum. Highest growth is expected in developing countries where per capita paint consumption is low, such as some Asian countries, Latin America and South America. (WSCA Item Number 03/08115)

Section 84 Organisation News and Profiles

ALPEROWICZ N: DuPont seeks to grow 'beyond titanium dioxide'. (Chem. Week 2003, Vol 165 No 5, 25.)
DuPont is planning to expand its operations beyond titanium dioxide to meet its 6% per annum growth target. The company's development initiatives include a paint branding effort which the company introduced in Europe, with do-it-yourself retailer B & Q, and nanoparticle technologies under development in the USA. DuPont is also looking at alliances, joint ventures and acquisitions in the titanium dioxide field. (WSCA Item Number 03/08133)

Reviews of the following books also appeared in the November 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

GOLDSCHMIDT A & STREITBERGER H-J: Basics of Coating Technology. (Vincentz Network, Hannover 2003, 792 pp. (ISBN 3-87870-798-3). Price 74 euros.) (WSCA Item Number 03/08205)

LOWE C: Characterisation and Measurement of Polymeric Materials. I. Analytical Methods for Surface Coatings. (Sita Technology Ltd, Edinburgh & London 2002, 256 pp. (ISBN 0-947-79898-6). Price œ100.00 ($150.00).) (WSCA Item Number 03/08206)

LOWE C: Characterisation and Measurement of Polymeric Materials. II. Applications for Surface Coatings. (Sita Technology Ltd, Edinburgh & London 2002, 233 pp. (ISBN 0-947-79804-8). Price œ100.00 ($150.00).) (WSCA Item Number 03/08207)

MITTAL K L (EDITOR): Particles on Surfaces 7: Detection, Adhesion and Removal. (VSP BV, Utrecht & Boston 2002, 451 pp. (ISBN 90-6764-372-6). Price 192 euros, $223.) (WSCA Item Number 03/08208)

WINKLER J: Titanium Dioxide. (Vincentz Network, Hannover 2003, 128 pp. (ISBN 3-87870-148-9). Price 69 euros.) (WSCA Item Number 03/08209)

top

Highlights of the Month - October 2003

The October 2003 issue contains abstracts of 756 articles including the following examples:

Section 43 Printing, Image-producing and Recording Materials

GRAHAM-ROWE D: Paper comes alive. (New Sci. 2003, Vol 179 No 2414, 16-7.)
A new display system is described, which may make 'electronic paper' a realistic prospect. The display is based on a phenomenon known as electrowetting, in which application of a voltage to a water-repellent surface makes it attract water. The new display system uses pixels comprising a chamber having a transparent water-repelling base, over a white substrate. A droplet of coloured or black oil is placed on the surface, which spreads and obscures the white base, and the chamber is filled with water. The pixels appear black or monochrome. When a voltage is applied the water is attracted to the base, wetting it and pushing the oil aside, thereby revealing the white background. The new process is said to be faster than previous methods, with change taking place in around 10 milliseconds, fast enough to cope with video images. To produce a multicolour display, each pixel comprises three sub-pixels, each of which contains two different primary-coloured oils, one covering a water-repelling surface at the top of the chamber and the second covering another surface at the bottom. On the top of each sub-pixel is a filter for the third primary colour. (WSCA Item Number 03/07104)

Section 64 Patents: Paints, Etc for Other Specific Uses

HRL LABORATORIES LLC: Photocatalytic coating and method for cleaning spacecraft surfaces. ( United States Patent 6537379, 11 pp. (Also European Patent Application 1,257,609).)
Photocatalytic coating, especially for prevention of build-up of polymerised hydrocarbon and/or silicone films on spacecraft surfaces is disclosed. It comprises titanium dioxide, titanium dioxide doped with copper or silver, or titanate of barium, strontium or lead. The coating may be applied by sputtering, electron beam evaporation or sol/gel processing. The cleaning process comprises reaction of the coating with a UV photon followed by oxidation of the hydrocarbons on the surface preventing polymerisation and resulting in evaporation and dissipation. A jet of oxidising agent (hydrogen peroxide or oxygen) is directed at the surface (at orbital altitudes) to regenerate the original form of titanium in the coating. Coating deposition and uses are claimed. (WSCA Item Number 03/07262)

Section 69 Analytical Methods

ANON: 'Litmus paper' developed for detecting lead paint. (Mat. Performance 2003, Vol 42 No 7, 4.)
It is briefly noted that chemists at a US university have claimed to have found a detection method that uses gold nanoparticles laced with deoxyribonucleic acid to produce a sheet that may be pressed against a wall, the sheet turning from blue to red in the presence of lead. (WSCA Item Number 03/07324)

Section 79 Radiation Curing

EL-GHAYOURY, BOUKAFTANE C, DE RUITER B & VAN DER LIND R: Ultraviolet/ultraviolet dual-cure process based on acrylate oxetane monomers. (J. Polym. Sci, Polym. Chem. 2003, Vol 41 No 4, 469-75.)
An approach was explored in which a liquid formulation is used that may be cured first by a radical photoinitiated polymerisation. This results in a flexible and hence deformable coating. At a later stage, the second cure with cationic, light-initiated cross-linking results in a coating with increased chemical and abrasion resistance. The approach was explored with two acrylate oxetane monomers: the first compound was prepared by the reaction of acryloyl chloride with 3-ethyl-3-hydroxymethyloxetane in the presence of triethylamine. Dual cure was demonstrated with these materials. It was shown that a spacer between the two reacting moieties was necessary in the second compound to prevent the failure of the second step, failure caused by the proximity of an ester to the oxetane group. High conversions of reactive species were obtained indicating the formation of a highly cross-linked coating. 22 refs. (WSCA Item Number 03/07436)

FOUASSIER J P, ALLONAS X & BURGET D: Photopolymerisation reactions under visible lights: principle, mechanisms and examples of applications. (Progr. Org. Coat. 2003, Vol 47 No 1, 16-36.)
A general overview of visible light photoinduced polymerisation reactions is presented. Reaction mechanisms as well as practical efficiency in industrial applications are discussed. Several topics are considered in detail, these being photochemical reactivity of photoinitiating system (PIS), short overview of available photoinitiators (PIs) and photosensitisers (PSs), mechanisms involved in selected examples of dye-sensitised polymerisation reactions, examples of applications in pigmented coatings usable as paints, textile printing, glass-reinforced fibres, sunlight curing of water-borne latex paints, curing of inks, laser-induced polymerisation reactions, high-speed photopolymers for laser imaging, and photoinitiating systems for computer-to-plate systems. 50 refs. (WSCA Item Number 03/07439)

Reviews of the following books also appeared in the October 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

AZAPAGIC A, EMSLEY A & HAMERTON I: Polymers, the Environment and Sustainable Development. (John Wiley & Sons Ltd, Chichester 2003, 219 pp. (ISBN 0-471-87740-9). Price œ85.00.). (WSCA Item Number 03/07578)

INTERNATIONAL MARINE COATINGS: Tributyltin Free Antifoulings and Foul Release Systems: the Economic Importance of Hull Condition. (International Marine Coatings, Gateshead 2003, 101 pp. (Available from publisher on request).) (WSCA Item Number 03/07579)

top

Highlights of the Month - September 2003

The September 2003 issue contains abstracts of 772 articles including the following examples:

Section 05 Solvents, Plasticisers and Intermediates

DIETER R K: Copper-mediated chemistry: new opportunities for industrial applications. (Speciality Chem. 2003, Vol 23 No 3, 46 (3 pp).)
Organo-copper reagents are reviewed in relation to catalytic organo-copper chemistry, copper hydride chemistry, arylation reactions, and asymmetric organo-copper chemistry. Although organo-copper chemistry has developed a reputation for various difficulties, a considerable database of successful transformations has been built up over the past 50 years. More recently, reductions with copper hydride and the substitution of aryl groups on to amine groups at modest temperatures, catalysed by a copper(I) compound with a 1,2-diamine, etc, have become useful reactions. 17 refs. (WSCA Item Number 03/06085)

Section 53 Weathering, Corrosion, Etc

KALENDOVA A: Effects of particle sizes and shapes of zinc metal on the properties of anticorrosive coatings. (Progr. Org. Coat. 2003, Vol 46 No 4, 324-32.)
Zinc particle sizes and shape effects on anticorrosive coating properties were investigated. The zinc particle size and shape effects are discussed from the points of view of the mechanical coating properties, the film permeabilities to water vapour and above all, the pigment anticorrosive efficiency. A connection between the spherical particle sizes and the coating anticorrosive efficiency was found. The smaller particle sizes provide better anticorrosive coating properties. The lamellar zinc particles exhibit the highest anticorrosion efficiency at a concentration of around 20 volume %. Binder was epoxy ester resin. 12 refs. (WSCA Item Number 03/06422)

Section 63 Paints, Etc for Other Specific Uses

JAEGER M & OTHERS: Experience with epoxy vinyl ester resins for chemical-resistant pipeline coatings. (Rev. Plasticos 2003, Vol 85 No 559, 45-52.)
Selection of coating material, fabrication of fibre-reinforced plastics pipelines and testing methods are discussed. Visual inspection and non-destructive testing methods are considered. (In Spanish with 12 refs.) (WSCA Item Number 03/06477)

CLEEVELY S T: Sensitive surfaces from piezoelectric polymers. (Materials World 2003, Vol 11 No 5, 27-8.)
A new polymer coating is described which is not only being used to increase the accuracy of non-destructive testing, but is also being applied to electronic devices as a 'sensor skin' to increase the interaction with computer technology. The active substance of the new coating is a vinylidene fluoride copolymer. (WSCA Item Number 03/06475)

Section 69 Analytical Methods

MOONGKHAMKLANG P & TAYLOR S R: Delineation of ionic pathways in organic coatings using a molecular probe technique. (Progr. Org. Coat. 2003, Vol 46 No 4, 259-65.)
The mode of ion entry through thin (10 micrometres) epoxy coatings was investigated using a chloride-specific chromophore in conjunction with fluorescence microscopy. Epoxy coatings were spin cast on to glass slides and exposed to sodium chloride salt solutions at ambient and low (2.5) pH for 1, 3, and 7 days. An additional variable included the age of the coating component materials as assessed from the date of manufacture. Following exposure to chloride solutions, the films were exposed to a chloride-specific chromophore, 6-methoxy-N-ethylquinolinium iodide. Fluorescence microscopy indicated that chloride ions were clustered in discrete sites on the surface of the coatings. The number of defect sites appeared qualitatively to increase with salt exposure time, but not to increase at low pH. It is observed that this proof of concept experiment provides a possible new avenue for the characterisation and quantification of coating degradation. 16 refs. (WSCA Item Number 03/06596)

Reviews of the following books also appeared in the September 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

GRAHAM J M: From British Titan Products to Huntsman Tioxide. (Huntsman Tioxide/John M Graham, Thirsk (North Yorkshire) 2002, 266 pp. (ISBN 0-9538045-1-8). Price œ21.)
(WSCA Item Number 03/06821)

UTECH B: Guide to High-performance Powder Coating. (Society of Manufacturing Engineers/Association for Finishing Processes, Dearborn (Michigan) 2002, 357 pp. (ISBN 0-87263-547-3, available in Europe from American Technical Publishers Ltd, Hitchin). Price œ72.00.)
(WSCA Item Number 03/06822)

top

Highlights of the Month - August 2003

The August 2003 issue contains abstracts of 763 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

CHEN Y-F, LEE C-Y, YENG M-Y & CHIU H-T: Preparing titanium dioxide with various morphologies. (Mat. Chem. Phys. 2003, Vol 81 No 1, 39-44.)
Titanium dioxide powder was prepared by hydrolysing titanium tetraisopropoxide (TTIP) in aqueous solution at pH 2, using surfactants. The anatase phase was formed when the precipitants were dried at 373 K. When the calcination temperature was below 773 deg. K, all the powders were crystalline in the anatase phase. The powders changed to the rutile phase when the calcination temperature exceeded 1173 K. The powder calcined at 673 K had spherical primary particles with diameters of approximately 8 nm. When the powders calcined at 673 K were heated in sodium hydroxide solutions at various concentrations at 423 K for 20 hours, titanium dioxide powders with different morphologies were obtained. After the powders were refluxed in 5 M sodium hydroxide solutions, flower-like titanium dioxide particles were formed. Nanotubes of titanium dioxide about 8 nm in diameter and over 600 nm long were obtained when the powders were refluxed in 10 M sodium hydroxide solution. 15 refs. (WSCA Item Number 03/05289)

MAILE F J: Substrate for pearlescent pigments: a review and future perspective. (Proc. PRA 7th Nurnberg Congress 'Creative Advances in Coatings Technology' (PRA, Teddington/Vincentz Verlag, Hannover), Nurnberg 2003., Vol I, 39-55.)
An insight into modern substrate/layer chemistry which results in a better understanding of pearlescent pigment technology is provided. Pearlescent pigments are introduced and the basic requirements for substrates and for layers used in pearlescent pigments are considered. Manufacturing procedures for substrate-free pigments, for pearlescent pigments and for the layers used in pearlescent pigments, are described. The evaluation of substrate materials and precipitated layers using scanning electron microscopy and transmission scanning electron microscopy is described. 89 refs. (WSCA Item Number 03/05295)

Section 49 Pretreatment and Application

JAHROMI S: Mechanism of bubble dissolution in reactive coatings: the role of benzoin. (Macromol. 2002, Vol 35 No 15, 5883-90.)
The fate of benzoin, or its polyethylene glycol ether, in a curing powder coating composition, in an air or nitrogen atmosphere indicated that the aromatic hydroxyketone accelerated the disappearance of bubbles, when they contained air. Mass spectroscopy revealed that, in presence of oxygen and when not etherified, benzoin was oxidised to benzil, which evaporated, above 100 deg. C. The powder coating consisted of proprietary polyester and epoxy resins, together with a phosphonium halide catalyst. 26 refs. (WSCA Item Number 03/05593)

Section 53 Weathering, Corrosion, Etc

MILLS D, MABUTT S & BIERWAGEN G: Investigation into the mechanism of protection of pigmented alkyd coatings using electrochemical and other methods. (Progr. Org. Coat. 2003, Vol 46 No 3, 176-81.)
Electrochemical techniques, particularly the electrochemical noise method (ENM), were used to monitor the performance of two- and three-coat alkyd systems in sodium chloride solutions. For one of the coating systems, comparison was made between the results from room temperature continuous immersion exposure and accelerated test, (both a cabinet test and a high temperature immersion test), and good correlation was obtained. Detached films were also examined to obtain mechanism information and to clarify how these alkyd coatings work to prevent corrosion. Both the direct current resistance characteristics, the noise resistance and the inhibitive properties of the extracts were examined. These tests appeared to provide information which is useful in deciding how effective the coating will be both when intact and when it needs to protect at a break or a scribe. It is noted that the work provides pointers for investigations of low volatile organic compound coatings from renewable resources such as water-soluble alkyd/linseed oil coatings. 12 refs. (WSCA Item Number 03/05652)

Reviews of the following books also appeared in the August 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

ANON: Environmental Consultancy Directory 2003. (Environmental Data Services Ltd, London, 2003, 112 pp. (ISBN 0-907673-20-1). Price œ50.00, free to ENDS Report subscribers.) (WSCA Item Number 03/06045)

ASH M & ASH I: Paint & Coating Raw Materials Electronic Handbook. Second Edition. (Synapse Information Resources Inc, Endicott (New York) 2003 . (ISBN 1-890595-61-6). Price $395.) (WSCA Item Number 03/06046)

INDUSTRY STATISTICS LTD: World Paint File. Third Edition. (DMG World Media (UK) Ltd, Redhill (Surrey) 2002, 420 pp. (ISBN 1-84313-025-4). Price œ999.00 (1578 euros).) (WSCA Item Number 03/06047)

McINTYRE P: Corrosion and Associated Costs in the UK Chemicals and Petrochemicals Sector. (Paint Research Association, Teddington 2001, 48 pp. Price œ25.) (WSCA Item Number 03/06048)

MORGAN N R & MORRELL S: WSCA Selected Topics: Concrete and Masonry. (Paint Research Association, Teddington (Middlesex) 2003, 122 pp. Price œ70 (œ60 to PRA Members). (Also available in Adobe Acrobat pdf format).) (WSCA Item Number 03/06049)

RANDALL D & LEE S (EDITORS): Polyurethanes Book. (John Wiley & Sons Ltd/Huntsman International LLC, 2002, 477 pp. (ISBN 0-470-85041-8). Price œ100.) (WSCA Item Number 03/06050)

top

Highlights of the Month - July 2003

The July 2003 issue contains abstracts of 775 articles including the following examples:

Section 35 Water-borne Paints and their Components

GHOSH B & CHATTOPADHYAY T: Novel approach to correlate permeability and porosity in latex coatings. (Paintindia 2002, Vol 52 No 12, 41 (6 pp).)
Experiments were conducted to establish conclusively the effect of pigment volume concentration (PVC) on porosity and on permeability to determine the product performance. The emulsion used was of the pure acrylate variety having a particle size of around 0.1 micrometres with a solid content and specific gravity (solid) of 50 and 1.1 respectively. The extender used was calcite having a particle size below 10 micrometres. Deionised water was used throughout the experiment. Based on the experimental results, it was concluded that porosity does not show any variation with varying film thickness, that porosity increases linearly with PVC above and below the critical PVC (CPVC), but there is a point of inflexion at CPVC, that permeability increases with PVC until CPVC, above which it decreases, and that the behaviour of permeability with porosity is similar to permeability with PVC. (WSCA Item Number 03/04682)

Section 55 Fouling and Microbiological Attack

ANON: Cooking fat reduces growths. (Farbe Lack 2003, Vol 109 No 4, 14.)
A baker from the North Sea island Sylt has developed an antifouling paint for boats based on old cooking fat from confectionary goods. The idea was based on the chance observation during sailing that a large fat clump did not attract any marine growth. (In German) (WSCA Item Number 03/04902)

Section 63 Paints, Etc for Other Specific Uses

MA Y, XU J, ZHU B & WU K: Study of infrared thermal images of chameleon-type building coatings. (J. Coatings Tech. 2003, Vol 75 No 940, 43-7.)
It was shown that when reversibly thermochromic pigments (going from coloured to white at a specific temperature) are added to normal white building coatings, the resulting coatings could absorb energy from a sunlamp below a switching temperature of 20 deg. C. The surface temperatures could reach almost the same value as that of a normal coloured building coating. The absorption stopped automatically above the switching temperature of 20 deg. C, and the surface temperatures could be lower than that of normal colourful building coatings by about 4 deg. C. Solar radiation exposure was also investigated; temperature/time plots at 23 and 32 deg. C measurement, showed that when the temperature was below the switching temperature, the chameleon-type building coating could absorb almost the same amount of solar energy as an ordinary coloured coating. When the temperature was above the switching temperature, these coatings could reflect more solar energy than the ordinary coloured coating. All the results showed that there is a possibility that the chameleon-type building coatings could be used to create a thermally comfortable building environment. (WSCA Item Number 03/04946)

Section 75 Pollution and Utilisation of Wastes

SAVASTANO D: Design for the environment. (Ink World 2002, Vol 8 No 8, 29-30.)
The results are discussed of a study carried out by the US Environmental Protection Agency on the environmental impact, cost and performance of solvent-based, water-based, and ultraviolet (UV) ink systems for the flexographic process. Health and safety was also considered. More than fifty trade organisations, ink companies, printers and related industries donated their time and products for the study, which took more than six years. It was found that no ink system was superior across performance, environmental, health and cost criteria, although each system had advantages. The choice of formulations within an ink system were just as important as the choice of ink system itself. Breaking the comparisons down, the study concluded that water-based inks outperformed solvent inks on low-density polyethylene and polyethylene/ethylene vinyl acetate, while solvent-based did better on the adhesive lamination test. UV did worse on the gloss, which is contrary to typical performance, although UV-cured inks displayed good trapping and resistance to blocking. In terms of average cost, factoring in materials, labour, energy and capital, water-based systems were the least expensive. (WSCA Item Number 03/05156)

Reviews of the following books also appeared in the July 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

ROBERTS M (EDITOR): Waste Management Yearbook 2003. (McMillan-Scott plc, Birmingham 2003, 132 pp. Price £25.00.) (WSCA Item Number 03/05286)

WARSON H: Applied Thixotropy and Allied Phenomena. (Warson H, Solihull 2003, 132 pp. (ISBN 0-9544724-0-3, available from warchem@warson.fslife.co.uk). Price £85, ?140 and $145, postage as specified.) (WSCA Item Number 03/05287)

top

Highlights of the Month - June 2003

The June 2003 issue contains abstracts of 763 articles including the following examples:

Section 53 Weathering, Corrosion, Etc

PLUMMER H & RACE J: Determining pipeline corrosion growth rates. (Corros. Management 2003, No 52, 16-21.) Inspection run comparison software which provides a direct, quantitative comparison of data from successive high-resolution in-line inspections is presented together with its use for external corrosion growth on an onshore pipeline, its use in probabilistic assessments and its use for internal corrosion of a North Sea offshore pipeline. The advantage of the assessment is that raw inspection data is compared allowing any differences due to tool technologies and analysis methods to be identified and eliminated. Therefore, corrosion growth rates associated with both new sites of corrosion and active corrosion sites in a pipeline are able to be accurately located and measured. 10 refs. (WSCA Item Number 03/04113)

MANSOUR E M E & OTHERS: Developing and testing a new anticorrosive coating containing algae as a natural inhibitor for preventing marine corrosion of steel. (J. Sci. Eng. Corros. 2003, Vol 59 No 3, 242-9.) Green algae were tested as a natural additive for a paint formulation based on vinyl chloride copolymer to evaluate its efficiency for protection of steel against corrosion in sea water using spectrophotometry, alternating current and direct current electrochemical measurements, visual inspection, and surface analysis. Both suspended and extracted forms of algae were used to achieve optimum performance of the algae-contained coatings. Poorest performance was obtained when algae was added in its suspended form, whereas the extracted form exhibited better performance based on impedance measurements. The data demonstrated that highest protection was obtained at the algae threshold concentration of approximately 1.4 wt. %. The scanning electron microscopy and energy-dispersive X-ray analysis together with visual inspection of coated specimens exposed to the marine environment gave very good support to the electrochemical data. The algal species was Ulva lactuca. 15 refs. (WSCA Item Number 03/04109)

Section 55 Fouling and Microbiological Attack

VEAZEY M V: Antifouling coating research borrows an old concept. (Mat. Performance 2003, Vol 42 No 3, 37.) The efforts of the US Navy and a Washington University polymer chemist to develop an antifouling coating based on dolphin skin is presented. The research is built on the hypothesis that interrupting the attachment of adhesion proteins - (glue-like substances secreted by the organisms) discourages the organisms from settling on these surfaces. Tests were carried out by mixing two contrary types of polymer, these being smooth, linear, and hydrophilic polyethylene glycol and a highly fluorinated, hyperbranched, and hydrophobic polytetrafluoroethylene-like polymer. (WSCA Item Number 03/04145)

Section 56 Patents: Fouling and Microbiological Attack

KING'S COLLEGE LONDON: Product from starfish. (European Patent Application 1192180, 66 pp. (Also PCT 00/75183).) The invention relates to a compound capable of providing antifouling properties and anti-adhesive properties, and which is obtainable from starfish, especially mucus secretions of Marthasterias glacialis. In a preferred embodiment the compound is a proteoglycan (derivative). A method of preparation and uses are also claimed. (WSCA Item Number 03/04157)

Reviews of the following books also appeared in the June 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

MURPHY M (EDITOR): Metal Finishing: 71st Guidebook and Directory Issue 2003. (Metal Fin. 2003, Vol 101 No 1A, 864 pp.) (WSCA Item Number 03/04510)

SURFACE COATINGS ASSOCIATION AUSTRALIA: Surface Coatings. Volume 2. Paints and their Applications. (Third Edition). (Surface Coatings Association Australia, Victoria 2002, 1233 pp. (ISBN 0-646-41711-8). Price A$90 (SCAA Members), A$115 (non-members).) (WSCA Item Number 03/04511)

top

Highlights of the Month - May 2003

The May 2003 issue contains abstracts of 748 articles including the following examples:

Section 53 Weathering, Corrosion, Etc

VINKA T-G: Corrosion of zinc-coated steel and carbon steel in carbonated concrete and chloride-containing concrete. (Nordisk Korrosion 2002, Vol 6 No 3, 6-11.)
Results showed that zinc-coated steel has a good corrosion resistance in carbonated concrete and also performs well in chloride-containing concrete for total chloride levels lower than 1.5 wt. % of the cement mass. For chloride levels above 1.5, the zinc coating still protects the steel but for a more limited period. (In Swedish with 10 refs.) (WSCA Item Number 03/03335)

Section 55 Fouling and Microbiological Attack

JELVESTAM M, EDRUD S, PETRONIS S & GATENHOLM P: Biomimetic materials with tailored surface micro-architecture for prevention of marine biofouling. (Surface & Interface Anal. 2003, Vol 35 No 2, 168-73.)
The preparation of materials with a designed surface micro-architecture that is able to prevent marine fouling by barnacles is described. Rows of steep microstructures with an elevation of a few micrometres separated from each other by 60 micrometres were manufactured using a biomimetic approach based on crystallisation of calcite on surfaces of chemically-patterned templates with carboxylate functionality. Templates were produced by the microcontact printing process using microfabricated silicone stamps with a surface micro-structure that was shown to prevent barnacle settling. Electron spectroscopy for chemical analysis, secondary ion mass spectrometry imaging and observations of wetting behaviour were used to examine the surfaces. The templates were used to grow surface microstructures by controlled crystallisation of calcium carbonate by immersion in calcium chloride solution. Crystals grew randomly on the acidic areas of surfaces with 60/40 micrometre lines, whereas they grew in a regular fashion on a surface stamped with tiny (3-6 micrometres) 16-mercaptohexadecanoic acid lines. The investigation showed that it is possible to prepare stable surface microstructures of a size up to 50 micrometres in a regular arrangement of lines. 37 refs. (WSCA Item Number 03/03361)

Section 64 Patents: Paints, Etc for Other Specific Uses

COLLOID SURFACE TECHNOLOGIES GMBH: Ski coating, compound for producing said coating and method for producing the compound . (European Patent Application 114451629 pp, (Also PCT 00/29490).)
The coatings are useful for skis and snowboards, providing good sliding properties; they also provide abrasion resistance over wider range of (snow) conditions, temperatures and humidity than conventional wax coatings. They contain polyions of polyelectrolyte(s) and, for counter charging the polyions, ions of fluorinated surfactant(s) with opposite charge to the charge of the polyions. The polyions and at least part of the surfactant ions form complexes in the coatings. The coatings may also contain fluorinated organic solvent or organic solvents and acids or bases. Preparation method is also claimed. (In German) (WSCA Item Number 03/03422)

Section 71 Other Properties and Testing Methods

LEE D I: Structure of model coatings: latex-bound plastics pigment coatings. (Progr. Org. Coat. 2002, Vol 45 No 4, 341-58.)
The immobilisation and consolidation of model coatings based on monodisperse polystyrene (plastics pigment/polymeric pigment) and styrene/butadiene copolymer latices of known particle sizes were investigated in terms of their packing volumes and the extent of latex shrinkage. The latex shrinkage was found to increase with increasing pigment volume up to the critical pigment volume concentration. The porosity of the coatings was calculated based on three proposed latex shrinkage models. The number of pores and the average equivalent spherical pore diameters were also calculated. The opacity and gloss of model coatings on polyester film substrates were measured and porosity was determined by a simple coating weight/thickness method. A minimum crack-free temperature of latex-bound coatings was proposed to better predict the behaviour of latices as pigment binders. The wet state of model coating dispersions, the surfaces of consolidated model coatings, and their internal structure were examined by electron microscopy and atomic force microscopy. (WSCA Item Number 03/03548

Section 75 Pollution and Utilisation of Wastes

WINTER E: Use of plants in treating paint shop effluents. (Besser Lackieren 2002, Vol 4 No 4, 3.)
A new organic plant-containing unit for effluent water treatment set up as a pilot project by an industrial painting undertaking in Mannheim is discussed. The plants stand on their roots in water in a container, and effluent to be purified is passed through the container. Together with the microorganisms present in the container the plants render the harmful materials in the effluent harmless by chemical action. The plants also store heavy metals in their leaves; the contaminated part of the plants must be removed and burnt. (WSCA Item Number 03/03598) (In German)

Section 82 Statistics

ANON: Corrosion costs by industry sector. (Mat. Performance 2002, Supplement (July) 4-8.)
Results from a US Federal Highway Administration investigation on the direct costs associated with metallic corrosion are presented. The US economy was divided into five major sector categories (infrastructure, utilities, transportation, production and manufacturing, and government) for analysis and these were further broken down into twenty-six sectors. The total direct cost of corrosion for all these sectors was $137.9 billion. This figure was then extrapolated to the total US economy ($8.79 trillion) for an annual cost of corrosion of $276 billion. Figures are provided for the various sectors, e.g, ships $2.7 billion, motor vehicles $23.4 billion, aircraft $2.2 billion, and chemical, petrochemical and pharmaceutical $1.7 billion. (WSCA Item Number 03/03662)

top

Highlights of the Month - April 2003

The April 2003 issue contains abstracts of 758 articles including the following examples:

Section 06 Patents: Solvents, Plasticisers and Intermediates

OXENO OLEFINCHEMIE GMBH: Process for preparing carboxylic esters. (United States Patent Application 20020028963, 10 pp. (Also European Patent Application 1,186,953.)
The carboxylic esters are obtained in improved yield by relatively quick batch process, which comprises reacting dicarboxylic or polycarboxylic acids or anhydrides with alcohols in liquid medium, with continuous removal of water and alcohol by azeotropic distillation, under specified conditions, preferably with neutralisation of excess acid or anhydride at end of reaction by adding base. Liquid removed from the reaction medium by azeotropic distillation is replaced in whole or in part with the alcohol. (WSCA Item Number 03/02305)

Section 17 Oxygenated Polymers

CZECH Z: Inhibition of radical polymerisation in solvent-based systems (security of solvent-based radical polymerisation of pressure-sensitive adhesive acrylic in a plant reactor). (J. Appl. Polym. Sci. 2003, Vol 87 No 8, 1354-7.)
The inhibitory effects were investigated of the addition, as an emergency shut down procedure, of a range of chain transfer agents and inhibitors in the preparation of acrylic resins. Materials added were phenothiazine, diphenylphenylenediamine, cuprous oxide, isopropanol, carbon tetrachloride, dodecyl mercaptan and trimethylolpropane tris(mercaptoacetate) (TTMA), all at 1% level. Best results were from trimethylolpropane trimercaptoacetate addition with phenothiazine and dodecyl mercaptan also being very effective. Isopropanol had little effect, while toluene and cuprous oxide additions had some effect. (WSCA Item Number 03/02351)

Section 49 Pretreatment and Application

SCHALEK R L, ASKELAND P & DRZAL L T: Ultraviolet surface treatments for improving copper/polyimide laminates. (Proc. RadTech 2002, Indianapolis 2002, 779-90.)
The use of ultraviolet and ultraviolet/ozone surface treatments for enhancement of copper/polyimide adhesion using toughened epoxy and polyester adhesives is discussed. ESCA results indicate that UV treatments create polar functionalities on the polyimide (hydroxyl and carboxylic acid) and the copper surface. The positive wettability and surface chemistry results, however, did not translate into a measurable improvement in laminate peel strength. 11 refs. (WSCA Item Number 03/02560)

Section 53 Weathering, Corrosion, Etc

OVERALL R: Double trouble. (Asia Pacific Coatings J. 2002, Vol 15 No 6, 64.)
Causes of corrosion problems in double-hulled tankers are described, it being noted that the first generation of double-hulled tankers were more susceptible than the single-hulled, with problems at the bottom of the inner cargo tanks and at the tank tops. The slower cooling in the double-skinned tankers allowed corrosive bacteria to thrive, causing problems at the tank bottoms. The tank tops were not double-skinned, allowing condensation within the tank when the outside temperature dropped; this, in combination with the carbon and nitrates in the head-space inert gas, resulted in corrosive potency. The high-tensile steel (a weight-saving measure) aboard double-hulled ships was suffering more because its constant flexing was shedding corroded layers, exposing fresh steel to the corrosive condensation. Preventive coatings are now commonly applied to a one- or two-metre band at the top and bottom of cargo tanks aboard double-hulled tankers. (WSCA Item Number 03/02597)

Section 63 Paints, Etc for Other Specific Uses

NIESING B Smart coatings. (Fraunhofer Mag. 2002, No 2, 8-12.)
Current applications and the future potential of thin-film coatings are discussed. Thin coatings suppress glare, protect tools and components from wear and friction, enhance the appearance of buildings, make plastics as hard as steel and prevent food from sticking to the frying pan. To allow new developments in thin-film coating and surface technology to make the leap from research laboratory to industrial application, however, processes are required which makes it possible to apply thin-film coatings cost-efficiently to large surface areas. New applications for thin-film coatings are seen to regularly emerge, such as the force-sensor coatings which provide a warning of wear and may thus add a 'smart' dimension to tools, components and machines. Further potential applications of thin-film coatings are providing a warning when a tool needs replacing or when a screw is no longer tight, coated mirrors that reflect X-ray light, and light-emitting plastics films. (WSCA Item Number 03/02652)

top

Highlights of the Month - March 2003

The March 2003 issue contains abstracts of 750 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

NAYAK C: Role of micaceous iron oxide in protective coatings. (Paintindia 2002, Vol 52 No 11, 57 (10 pp).)
The physical and chemical characteristics of micaceous iron oxide pigments and their effects on the final coating performance are discussed. Several other factors such as their incorporation level, the influence of pigment volume concentrations, their compatibility with different binders and extenders, are also discussed. The mechanism, using micaceous iron oxide is also discussed in detail. Special emphasis is focused on their water permeability and weatherability characteristics. The blistering behaviour of the pigmented paint film is explained on the basis of water vapour transmission phenomena. 25 refs. (WSCA Item Number 03/01514)

Section 53 Weathering, Corrosion, Etc

McMURRAY H N, WILLIAMS G, O'DRISCOLL S & MORGAN P C: Scanning electro probe techniques in aluminium alloy corrosion. (Corros. Management 2002, No 50, 12-6.)
Two scanning techniques, scanning vibrating electrode technique (SVET) and the scanning Kelvin probe (SKP), are described together with their respective use in quantifying the inhibition of pitting corrosion and filiform corrosion affecting uncoated and organic-coated aluminium alloy. The data obtained are capable of being analysed to provide both quantitative kinetic relationships and mechanistic insight. Furthermore, because data may be acquired quickly, and under conditions of minimal perturbation, the techniques may form the basis of accelerated corrosion tests for the comparison of, for example, different corrosion inhibitor systems. Consequently, it is to be anticipated that scanning electrochemical probe techniques will see increasing application in the development of anticorrosion treatments and coatings. (WSCA Item Number 03/01827)

Section 54 Patents: Weathering, Corrosion, Etc

DU PONT DE NEMOURS & CO: Coating composition having improved acid etch resistance. (United States Patent 6379807: Off. Gaz. 2002, Vol 1257 No 5, 5550.)
A coating composition comprises 40 to 75 wt. % of a film-forming binder and 25 to 60 wt. % of a volatile liquid carrier. The binder comprises 20 to 70 wt. % of a silyl-containing acrylic polymer, 10-60 wt. % organic polyisocyanate and 5-40 wt. % melamine component. The silyl-containing acrylic polymer comprises polymerised monomers (selected from the group consisting of an alkyl methacrylate, an alkyl acrylate, each having 1 to 12 C atoms in the alkyl group, cycloaliphatic alkyl methacrylate, cycloaliphatic alkyl acrylate, styrene and any mixture of these monomers), hydroxy-containing monomers (selected from the group consisting of hydroxyalkyl methacrylate, hydroxyalkyl acrylate each having 1 to 4 C atoms in the alkyl group, or any mixtures of these monomers) and an monoethylenically unsaturated silane monomer. (WSCA Item Number 03/01848)

Section 79 Radiation Curing

KIM Y-B, KIM W-S, YU J-A & HONG J-W: Ultraviolet (UV)-cured transparent films including non-aqueous conductive microgels. (Polym. Adv. Technol. 2002, Vol 13 No 7, 522-6.)
Ultraviolet-curable compositions were prepared, with potential as transparent antistatic coatings, having stability to thermal ageing and humidity. A lightly cross-linked acrylic copolymer dispersion was first prepared. The water content was reduced by stirring with butanol. Subsequently, aniline was oxidised with ammonium persulphate to polyaniline, in presence of dodecylbenzenesulphonic acid and the acrylic copolymer dispersed in butyl acetate. The microgel acrylic dispersion was thereby coated with the conductive polymer, which was doped with the sulphonic acid. Finally, UV-curable compositions were formulated with the conductive dispersion, various polyfunctional acrylates and photoinitiators. Coatings cured on a flexible polyester substrate displayed surface resistivities of 10-100 megohms/sq. 16 refs. (WSCA Item Number 03/02092)

Section 87 Legislation and Other Official Publications

VELTMAN C: Navigating European Union paint transport regulations. (Coatings World 2002, Vol 7 No 5, 16-7.)
Problems such as varying restrictions between countries and lever-lid tins are discussed as is the way in which a level of consolidation in European policies surrounding the transportation of dangerous goods is beginning to take shape. Different countries are very particular about moving paint and keeping up with the rules may be difficult. France and Spain, for instance, have a number of route restrictions for dangerous goods. Paint is not allowed to be transported through tunnels on Paris's Peripherique. Meanwhile, in Spain, the transportation of dangerous goods is prohibited during the weekends. Rules for transporting paint by sea also vary from sending it by road or rail. Hence, while the trigger level for classifying pollutant levels in a particular cargo of paint is 10% for transport by sea, it is 25% for both road and rail. Paint is also only allowed to travel if it contains known substances, that is, substances listed in the European inventory of existing chemical substances (EINECS). (WSCA Item Number 03/02215)

Reviews of the following books also appeared in the March 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

top

Highlights of the Month - February 2003

The February 2003 issue contains abstracts of 751 articles including the following examples:

Section 21 Nitrogenous Polymers

GURKE T: New advances in polymeric diphenylmethane diisocyanate variants. (Paint & Resin Times 2002, Vol 1 No 4, 22-3.)
Results are presented of cold stability and cure behaviour of several mixtures based on polymeric and monomeric diphenylmethane diisocyanate, and uretonimine-modified products. The complexity of polymeric diphenylmethane diisocyanate chemistry is also discussed, together with polyol/isocyanate systems. It is considered that polymeric diphenylmethane diisocyanate and its variants have a strong influence on the final performance of an adhesive and coating. Parameters such as cure behaviour and viscosity are directly related to the polymeric diphenylmethane diisocyanate variant used. Choosing the right isocyanate is crucial as it provides more versatility for the production of one- or two-component products. (WSCA Item Number 03/00858)

Section 55 Fouling and Microbiological Attack

HELLIO C & OTHERS: Screening of marine algal extracts for anti-settlement activities against microalgae and macroalgae. (Biofouling 2002, Vol 18 No 3, 205-15.)
The antifouling activity of a series of aqueous, ethanolic and methylene chloride extracts from thirty algae from the north-east Atlantic coast was investigated. The extracts were tested in laboratory assays against species representative of two major groups of fouling organisms, i.e, macroalgae and microalgae. The activity of several extracts was comparable to that of heavy metals and biocides (such as tributyltin oxide and copper sulphate) currently used in antifouling paints, and their lack of toxicity with respect to the larvae of oysters and sea urchins suggests a potential for novel active ingredients. 35 refs. (WSCA Item Number 03/01091)

Section 64 Patents: Paints, Etc for Other Specific Uses

BASF COATINGS AG: Intrinsically viscous clear powder coating slurry which is free of organic solvents and external emulsifiers, method for producing said slurry and use of the same. (European Patent Application 1123355, 28 pp. (Also PCT 00/15721).)
Intrinsically clear viscous powder coating slurry free of organic solvents and of external emulsifiers is disclosed. It provides high gloss with good scratch and weather resistance, and good adhesion to metal, glass, wood and plastics. It contains spherical particles of specified size, together with ionic thickener(s) and non-ionic associative thickener(s); the slurry contains specified proportions of ion-forming groups and neutralising groups. Particles may contain polyacrylate binder and blocked polyisocyanate cross-linking agent, or may contain polyol with blocked polyisocyanate and/or tris(alkoxycarbonylamino)triazine. Preparation and use for original-equipment-manufacture and refinishing are also claimed. (WSCA Item Number 03/01145) (In German)

BREWER SCIENCE INC: Anti-reflective coating compositions comprising polymerised amino resins. (United States Patent 6432611: Off. Gaz. 2002, Vol 1261 No 2, 1768.)
The combination of a substrate having a surface, and an anti-reflective layer on the substrate surface, is described. The anti-reflective layer includes a quantity of a polymer comprising specified recurring triazine monomers, the polymer having an average molecular weight of at least 1000. (WSCA Item Number 03/01151)

Section 71 Other Properties and Testing Methods

STIRLING C: Assessing moisture in building materials. II. Measuring moisture content. (BRE Good Repair Guide 2002, No 33 part 2, 1-6.)
Techniques available for measuring moisture content in building materials are discussed, considering the electrical resistance method, drilling techniques, the calcium carbide technique, removable cores and samples, and environmental monitoring (data logging). It is noted that environmental monitoring is generally more appropriate in the assessment of consideration risk; it may, however, be used to establish the extent of moisture storage within building materials and components. (WSCA Item Number 03/01323)

Reviews of the following books also appeared in the February 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

top

Highlights of the Month - January 2003

The January 2003 issue contains abstracts of 751 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

TATSUMA T & OTHERS: Energy storage of titanium dioxide/tungsten trioxide photocatalysis systems in the gas phase. (Langmuir 2002, Vol 18 No 21, 7777-9.)
Storage of energy in a mixed titanium dioxide/tungsten trioxide coating, on a conductive glass substrate, was demonstrated to occur in pure water or moist air. This extension of the conditions under which energy storage is possible, following ultraviolet irradiation of the mixture, is considered significant for anticorrosive, antibacterial and photochromicity applications. Recycling of the energy storage was investigated. 17 refs. (WSCA Item Number 03/00010)

Section 07 Driers and Minor Additives

WICKERS A G: Amide organo-wax rheology modifying additives: a perspective on organo-wax selection for high-build coatings. (Surface Coatings Austral. 2002, Vol 39 No 9, 10-5.)
Some of the issues that need to be addressed in high build coatings are discussed, as are selecting the best type of rheological modifier, and various organo-wax rheological modifiers. Hydrogenated castor oil organo-waxes, amide organo-waxes, first generation amide waxes, broadband/focused applications, and second generation amide waxes are considered. A selection chart for a proprietary range of amide waxes is provided. (WSCA Item Number 03/00058)

Section 49 Pretreatment and Application

SVANE P: Heavy-duty paints for salt-spreading vehicles. (Industriel Overfladebehandling 2002, Vol 11 No 2, 8 (2 pp).)
A new unit, for application of a two-component coating system and using computer control, is described. (In Danish) (WSCA Item Number 03/00268)

Section 53 Weathering, Corrosion, Etc

CAPANESCU C & CINCU C: Ultraviolet inhibitors in polyester gel coats. (Paint & Coatings Ind. (US) 2002, Vol 18 No 9, 50 (7 pp).)
Two UV light stabilisers (a hydroxylated benzotriazole and a hydroxylated benzophenone) and a hindered amine light stabiliser (a piperidinyl sebacate) were evaluated in the polyester gel coat of fibre-reinforced plastics panels. Gloss and colour changes on weathering were measured. Accelerated and natural weathering were employed. Both the hydroxyphenylbenzotriazole and the hydroxybenzophenone evaluated provided equal results. The total colour change was significantly reduced when combined with the hindered amine light stabiliser. By itself, the hindered amine light stabiliser does not provide any surface stability improvement in the gel coat. The best results were obtained with the highest amounts of inhibitors. 12 refs. (WSCA Item Number 03/00297)

Section 69 Analytical Methods

MALLEGOL J & OTHERS: Influence of drier combination on through-drying in water-borne alkyd emulsion coatings observed with magnetic resonance profiling. (J. Coatings Tech. 2002, Vol 74 No 933, 113-24.)
An examination was made of the physical changes that accompany autoxidative cross-linking in alkyd films (cast from water-borne emulsions) in the presence of various combinations of metal carboxylate driers. A newly developed type of magnetic resonance (MR) profiling was used in conjunction with conventional techniques (drying tests, pendulum hardness, and mass uptake). The magnetic resonance profiling non-invasively probes the molecular mobility of the alkyd as a function of depth (with a pixel resolution of about 9 micrometres), over drying times ranging from minutes to weeks. It thereby indicates drier efficiency by its sensitivity to viscosity build-up during drying and to subsequent film hardening. It was shown unequivocally that more uniform cross-linking is achieved using a combination of a primary (cobalt) and a secondary (calcium) drier, in support of conventional belief. Furthermore, these results yielded new insight into the chemical mechanisms induced by the driers and are thus of clear benefit to coatings researchers and formulators. Notably, the secondary driers improve the efficiency of the hydroperoxide decomposition reactions, but they are only active during an initial period, after which cross-linking non-uniformity develops. Measurements involved cobalt drier alone, or with calcium and/or zirconium driers. 39 refs. (WSCA Item Number 03/00488)

Reviews of the following books also appeared in the January 2003 issue of WSCA: the full book reviews can be read on the library catalogue page of the PRA web site - www.pra.org.uk.

LANG H: Colour and its Reproduction. I. Colorimetry. (Muster-Schmidt Verlag, Gottingen/Zurich 2002, 181 pp. (ISBN 3-7881-4056-9). Price 35 euros.) (WSCA Item Number 03/00750)

MORGAN N R & MORRELL S: WSCA Selected Topics: Wood. (Fourth edition). (Paint Research Association, Teddington (Middlesex) 2002, 126 pp. Price £70, £60 to PRA Members. Also available in Adobe Acrobat pdf format.) (WSCA Item Number 03/00751)

top