World Surface Coatings Abstracts (WSCA) - Highlights 2008

January - February

WSCA Highlights of the Month - March 2008

The March 2008 issue of WSCA contains abstracts of 610 articles including the following examples:

Section 02 Patents: Pigments, Extenders, Dyestuffs and Phosphors

OMYA DEVELOPMENT AG Composites of inorganic and/or organic microparticles and nano-dolomite particles. World (PCT) Patent Application 2007/141271, 73 pp.
Composites are disclosed, which comprise inorganic and/or organic pigments and/or fillers in the form of microparticles, the surface of which is coated at least partially with finely divided nano-dolomite with the help of binders based on copolymers comprising as monomers one or more dicarboxylic acids and one or more monomers from the group of diamines, triamines, dialkanolamines or trialkanolamines. A method for producing such composites, aqueous slurries thereof, their use, and the use of the binders for coating the microparticles with nano-dolomite are also claimed. Use of the composites in fillers and coatings, especially paper coatings, is also claimed. (WSCA Item Number 08/01363)

Section 04 Patents: Oils, Waxes and Related Materials

ZHANG G Natural plant type paint and its preparation method. Chinese Patent 1786095.
A natural plant type coating and its preparation method are disclosed. The coating is formed from high-molecular film-forming material, pigment, adjuvant and solvent. It is characterised in that the oil material adopted in the high-molecular film-forming material contains 30-40 parts of linseed oil, 35-45 parts of limonene, 5-15 parts of polybasic alcohol, polybasic acid which comprises 8-15 parts of phthalic anhydride and 2-5 parts of trimellitic anhydride, adjuvant comprising 0.02-0.1 parts of catalyst lithium hydroxide, drier comprising 1-3 parts of composite rare earth, and solvent containing 5-10 parts of pine cone oil and 5-10 parts of terpineol. The raw materials are mixed to obtain the film-forming material. A slurry material is formed by mixing deionised water, 18-35 parts of pigment titanium dioxide, drying, dispersing, anti-freezing, defoaming, anticorrosion and film-forming adjuvants, talc and natural calcium carbonate. 10-20 parts of film-forming material are employed to make emulsion, deionised water, the slurry material and thickening agent are added, and mixed so as to obtain the coating. (WSCA Item Number 08/01375)

Section 22 Patents: Nitrogenous Polymers

SIKA TECHNOLOGY AG Volatile organic compound (VOC) free or low VOC polyurethane coating. European Patent Application 1876196, 19 pp. (Also PCT WO 20(WSCA Item Number 08/000831).
Humidity-hardening compounds containing at least one polyurethane polymer are disclosed. They contain an isocyanate group, at least one polyimine of specified general formula in an amount of at least 22 wt. %, in relation to the sum of the components of the compound which contain the isocyanate group, as well as, if necessary, a polyisocyanate oligomer. The humidity-hardening compound is particularly suitable for providing coatings and linings. The use of the imines makes possible VOC-free or VOC poor compounds, which is a substantial advantage for indoor applications. (In German) (WSCA Item Number 08/01467)

Section 55 Fouling and Microbiological Attack

CHANG Q & OTHERS Bactericidal mechanism of silver/aluminium oxide against Escherichia coli. Langmuir 2007, Vol 23 No 22, 11197-9.
Escherichia coli cells became severely disrupted by contact with the prepared silver/aluminium oxide bactericide. In contrast, little change in the cells resulted from treatment with aqueous silver ions. Furthermore, prior treatment of the binary biocide with superoxide dismutase and/or catalase, which respectively deactivate superoxide anion radicals and hydrogen peroxide, weakened the bactericidal efficacy of the modified aluminium oxide. Hence, it was concluded that the bactericide acted by a catalysed oxidation of the bacterial cells. Ultraviolet irradiation weakened this, whilst blackening the initially white bactericide. This indicated that silver oxide was beneficial for the bactericidal activity. Synergy of the two components in the cell disruption was also identified. 14 refs. (WSCA Item Number 08/01632)

Section 64 Patents: Paints, Etc for Other Specific Uses

ADVANCED CARDIOVASCULAR SYSTEMS INC Bioabsorbable, biobeneficial polyester polymers for stent coatings. United States Patent 7301001: Off. Gaz. 2007, Vol 1324 No 4.
A polymer is disclosed comprising an alcoholic moiety derived from an aliphatic diol, triol, or polyol, an acidic moiety derived from a polycarboxylic acid (I), and a biobeneficial moiety. The biobeneficial moiety is derived from polypropylene glycol, proprietary surfactants, block copolymers comprising polyethylene glycol and polypropylene glycol, hydroxy-functional polyvinylpyrrolidone, dextrin, sodium hyaluronate, hyaluronic acid, elastin, water-soluble heparin, water-soluble elastin, tropoelastin, poly(2-hydroxyethyl methylmethacrylate), heparin, hirudin, sulphonated polystyrene, superoxide dismutase mimetics, antioxidants, or free radical scavengers. The polycarboxylic acid (I) is selected from the acidic moiety derived from at least one diacid selected from straight chain aliphatic diacids having 2 to 20 C atoms, terephthalic acid, fumaric acid, citric acid, citramalic acid, tricarballylic acid, tartaric acid, isophthalic acid, 1,6-bis(p-carboxyphenoxy)hexane, 1,3-bis(p-phenoxycarboxy)propane, 1,4-bis(p-phenoxycarboxy)butane, and oligomeric diacids with anhydride bonds in the backbone. (WSCA Item Number 08/01685)

For further information on WSCA please contact Dr Norman Morgan

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WSCA Highlights of the Month - February 2008

The February 2008 issue of WSCA contains abstracts of 603 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

BURGIO L & OTHERS Spherical copper resinate on Coromandel objects: analysis and conservation of matt green paint. Studies Conservat. 2007, Vol 52, No 4, 241-54.
An unusual green pigment was found on a seventeenth-century kuan cai (Coromandel) lacquer screen at the Victoria and Albert Museum, London. The particles were perfectly spherical and translucent, with the appearance of green fish roe. Analysis revealed that the pigment was a copper resinate, produced by reacting a copper salt with a resin, probably from a Pinus species. The binding medium for the pigment is proteinaceous. In light or olive green areas, the pigment is mixed with lead white, and the paint is glossy and well-preserved. In contrast, in the dark green areas where the pigment was used alone, the paint is matt and powdery and there is significant paint loss and abrasion. The problem of consolidation of the powdery paint, while still preserving the matt appearance of the surface, was resolved by the use of immiscible solvents and consolidant. 45 refs. (WSCA Item Number 08/00716)

SHI X & GAN Z Preparation and characterisation of polypropylene carbonate/montmorillonite nanocomposites by solution intercalation. Europ. Polym. J. 2007, Vol 43 No 12, 4852-8.
Nanocomposites of polypropylene carbonate of stated molecular weight, together with various proportions of organically-modified montmorillonite, exhibited, e.g, tensile strength and a glass transition temperature higher than those of the unmodified silicate. Thus, the improved properties were 23.1 MPa and 34 deg. C, which is 13 deg. higher than that of the polycarbonate alone. The optimum content in the nanocomposites of layered, modified silicate, containing cetyltrimethylammonium cations, was 4% by wt. 20 refs. (WSCA Item Number 08/00735)

Section 03 Oils, Waxes and Related Materials

KOBAYASHI S, UYAMA H, TSUJIMOTO T & KUWABARA M New synthesis of functional polymers using renewable resources from plant oils. ACS, Polym. Preprints 2007, Vol 48 No 2, 830-1.
The production of functional polymeric materials using renewable resources mainly based on plant oils is examined and the lipase-catalysed polyester synthesis from natural alcohols and fatty acids is described together with the green nanocomposite synthesis from plant oils. Thus, reaction of divinyl sebacate with triols such as glycerol, and of sorbitol with divinyl sebacate, and incorporation of unsaturated fatty acid or epoxidised fatty acid in the polyester, are considered in the former synthesis. In the latter, green nanocomposites showing elasticity were prepared as an organic/inorganic hybrid material by acid-catalysed curing of epoxidised plant oils in the presence of organophilic clay or with a silane compound. 12 refs. (WSCA Item Number 08/00772)

Section 53 Weathering, Corrosion, Etc

LEE C-H, SHIN C-S & BAEK K-K Electrochemical impedance spectroscopy studied to evaluate coatings for ballast tanks and splash zones. J. Protect. Coat. Linings 2007, Vol 24 No 10, 17 (3 pp).
Electrochemical impedance spectroscopy (EIS) was adopted to quantitatively and effectively select coating systems having optimised performance for the protection of water ballast tanks of ships and the splash zone of offshore structures. Several epoxy and epoxy/polyurethane coating systems were tested using a wet/dry cyclic exposure to accelerate their degradation. A plausible prediction model for determining the remaining lifetime of coating systems was also proposed. The electrochemical impedance spectroscopy measurements were carried out in natural sea water at room temperature. By using electrochemical impedance spectroscopy it was found possible to predict the lifetime of coatings by determining the time taken for their impedance to fall to about 10 to the power 7 ohms/sq. cm. It was also concluded that the use of temperatures higher than the glass transition temperature (Tg) of the coating to accelerate coating degradation in a wet/dry cyclic test causes unrealistic and unpredictable results. (WSCA Item Number 08/01025)

SHI X, FERNANDO B M D & CROLL S G Concurrent physical ageing and degradation of cross-linked systems in accelerated weathering: examination of thermal cycling and cross-link density effect. Proc. Federation of Societies for Coating Technology '2007 FutureCoat' (ICE 2007) Conf, Toronto 2007, Paper, 19 pp.
Two cross-linked coating systems (polyurethane and epoxy) were investigated in order to compare different chemical composition, their glass transition temperature, and their thermal response in accelerated weathering. During thermal cycling, physical ageing measured by enthalpy recovery exhibited different trends in the two coatings. A rejuvenation mechanism was observed in the coating with a glass transition temperature between the top and bottom limits of the exposure cycle, continued ageing being observed for the coating with a high glass transition temperature. Stress relaxation tests detected ageing and memory behaviour over periods comparable with accelerated weathering cycles. It is considered that when various coatings are evaluated, simply judging their performance under the same weathering environment is not reliable since polymer relaxation behaviour depends on the relationship between the exposure temperatures and the glass transition temperature of each polymer. 41 refs. (WSCA Item Number 08/01031)

A review of the following book also appeared in the February 2008 issue of WSCA: book reviews can be read on the Library Catalogue page of the PRA web site.

STREITBERGER H-J & DOSSEL K-F Automotive Paints and Coatings. 2nd Edition. Wiley-VCH Verlag GmbH, Weinheim 2008, 493 pp. (ISBN 978-3-527-30971-9). Price £110.00 (154.00 euros)
(WSCA Item Number 08/01315)

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WSCA Highlights of the Month - January 2008

The January 2008 issue of WSCA contains abstracts of 712 articles including the following examples:

Section 01 Pigments, Extenders, Dyestuffs and Phosphors

KROGER N & OTHERS Bio-enabled synthesis of amorphous and crystalline titanium dioxide at ambient temperature and neutral hydrogen ion concentration (pH). ACS, Div. of PMSE, Papers 2007, Vol 96, 71-2.
It was demonstrated that recombinant proteins, encoded by selected regions of silaffin genes from diatoms, exhibit titanium dioxide-forming, as well as silica-forming activities. The substrate was a titanium complex. The unique molecular characteristics of one of the recombinant silaffin enabled the synthesis of rutile titanium dioxide at ambient temperature and pH 7. The protein-induced rutile formation is expected to enable previously inaccessible pathways for the synthesis of photonic materials. (WSCA Item Number 08/00018)

Section 49 Pretreatment and Application

ELLIOTT P T, STEFFENHAGEN M J & GLASS J E Spray applications. III. Assessment of viscosities at high shear rates and dynamic uniaxial extensional viscosities on fan nozzle air sprayability. J. Coatings Tech. Res. 2007, Vol 4 No 4, 341-9.
Water-soluble polymer blends of high molecular volume hydroxyethylcellulose/high molecular volume polyoxyethylene and low molecular volume hydroxyethylcellulose/high molecular volume polyoxyethylene were prepared with similar low shear viscosities but different high shear rate viscosities. The three solutions within a set of blends all had essentially the same low and high shear viscosities, surface tension and elasticity, but different dynamic uniaxial extensional viscosities; this allowed the role of high shear rates and dynamic uniaxial extensional viscosity to be separated in their influence on atomisation and sprayability. It was determined through visual analysis of air spray (55 pounds per square inch, fan nozzle) patterns that the dynamic uniaxial extensional viscosity is the dominant parameter in controlling the atomisation and sprayability of these simple water-soluble polymer blends. It was found that the low molecular volume hydroxyethylcellulose blends with high molecular volume polyoxyethylene produced higher dynamic uniaxial extensional viscosity. 19 refs. (WSCA Item Number 08/00324)

GEHRKE J, DRUMMER B & BAUER H K Powder coating on metal parts using eddy current curing. Besser Lackieren 2007, Vol 9 No 11, 16.
The application of eddy current curing to powder coatings applied to metal parts is described. Eddy current techniques have previously been used for coating removal, and for precleaning, and the results of a research project into their use for curing of powder coatings are provided. The eddy currents generated cause an increase in temperature in the metals to be coated, thus providing sufficient energy to cure the applied powder coatings. Due to the more rapid warming than may be achieved in conventional ovens, there are potential cost, time and energy savings from using eddy current curing. (In German) (WSCA Item Number 08/00326)

Section 69 Analytical Methods

KEUNE K & BOON J J Analytical imaging studies of cross-sections of paintings affected by lead soap aggregate formation. Studies Conservat. 2007, Vol 52 No 3, 161-76.
Paint cross-sections from five paintings affected by lead soaps were examined by the analytical imaging techniques of Fourier transform infrared spectroscopy, secondary ion mass spectroscopy and scanning electron microscopy combined with X-ray analysis. Interactions between the reactive components in paints forming lead soaps are discussed, as are multilayered paint systems with various lead-containing pigments, remineralisation inside lead soaps aggregates, and chloride inside lead soap aggregates. It is concluded that the various case studies demonstrate that one general scenario describing all aspects of the lead soap aggregates is unable to be given yet, the difficulty being that although formation of lead soaps is straightforward, the conditions under which this is happening are so multifaceted. 36 refs. (WSCA Item Number 08/00516)

Section 87 Legislation and Other Official Publications

ANON REACH (registration, evaluation and authorisation of chemicals): the basics. UK REACH Competent Authority Leaflet No 5, 2008, 4 pp. (Available at www.hse.gov.uk/reach/resources/basics.pdf).
The key stages in the REACH (registration, evaluation and authorisation of chemicals) process are described, considering preregistration, registration, evaluation, and authorisation. Reference is also made to restrictions, to classification and labelling, and to safety data sheets. (WSCA Item Number 08/00677)

For further information on WSCA please contact Dr Norman Morgan

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