Titles and abstracts

Citation

(2009), "Titles and abstracts", Pigment & Resin Technology, Vol. 38 No. 1. https://doi.org/10.1108/prt.2009.12938aad.016

Titles and abstracts

Article Type: Conferences, training and publications From: Pigment & Resin Technology, Volume 38, Issue 1

Progress in the development and evaluation of coating additives

The development and evolution of coatings has been accelerated in the past decade by impending legislation, including the Solvent Emissions Directive, which is now having a real impact on the choice of coatings technology, and the constraints under which it operates. In parallel with this are operational and economic pressures and a market drive for innovative products. Few if any modern coatings are viable without additives, which enable the potential of any coating formulation to be delivered, confer additional properties and are instrumental in reducing operational problems. This review considers examples of developments that have been necessary for additives to maintain their crucial role in the current climate. The potential for combinatorial and service life prediction techniques, in speeding development, is also considered.

Jon Graystone

PRA, UK

The European coating dispersant market

Coating dispersants are the speciality additives class chemicals which are applied to coating formulations to enhance the dispersion process, stabilise pigments in coating formulations and improve compatibility between ingredients. Dispersants significantly reduce manufacturing costs for coating formulations and upgrade final products. The dispersants are divided by product type into high-molecular weight dispersants, low-molecular weight dispersants and surfactants. The dispersant range in the market is represented by acrylics, polyurethanes, polycarboxylates, vinyl acetate esters, polyphosphates, ethoxylates, lecitins, sulphates and fatty acid derivates. The technological developments in the market are driven by legislation and demand towards aqueous and high-solids systems, high-performance and high-molecular weight dispersants, environmentally friendly compounds. The research covers coating dispersants applied to the following three major sectors: automotive, industrial and decorative coatings.

Yana Charushkina

Frost & Sullivan, UK

Specialty anionic wetting additives for low VOC aqueous coatings

The development of VOC compliant, aqueous coatings has increased the need for wetting additives. The absence of solvent has affected critical coating properties such as substrate wetting and adhesion, surface flow and levelling, gloss and colour uniformity. The use of a unique, anionic, low surface tension additive to improve these coating properties is featured in this presentation. Performance of a no VOC version of the wetting additive is presented. The presentation compares the performance of low VOC aqueous coatings with various wetting additive chemistries.

Gerald Krätschmer

Troy Chemie, Germany

Optimising performance with tailored pigment dispersing technology

The dispersion of pigments and their performance properties are critical factors for many coatings applications, from automotive and industrial systems to decorative coatings. Improvements in this area offer a coatings formulator options to decrease cost, improve quality, or differentiate their product to achive competitive advantage. Dispersants play a vital function in maximising the performance of pigments in aqueous systems, but their use can be difficult and time consuming to optimise due to the diversity of pigment chemistries and grades available, as well as the competitive interactions often seen with other functional additives. Compounding this issue is the often proprietary nature of the dispersants themselves, limiting the ability of a formulating chemist to use fundamental theory and forcing greater reliance on trial and error methodology. A solution to this dilemma is the development of surface active additives which are essentially pre-optimised for specific performance needs. Through tailoring the affinic characteristics for maximum interaction with targeted pigment chemistries, significant reductions in competitive behaviour can be achieved and destabilisation issues such as shock in letdown are minimised. Additional optimisation of the stabilisation mechanisms can yield robust dispersion resistance to flocculation with efficient additive levels and minimal waste. This paper will describe the methodologies employed and the results achieved in the development of this type of additive solution.

Wim Stout* and Mike Peck

Air Products, The Netherlands

New siloxane-based superspreaders for excellent substrate wetting

One of the major issues for coatings development and applications is the adhesion to various substrates, particularly of water based systems. Adhesion highly depends on several factors like wetting of the substrate, interfacial relation (surface tensions) or chemical bonding. This paper will focus on substrate wetting and show how to control the wetting with specific siloxane-copolymers. Trisiloxane alkoxylates are a unique class of silicone surfactants that exhibit a very interesting phenomenon called superspreading. Low surface tension (20.7 mN/m) and adynamic surface tension gradient setup by the unique structure of trisiloxane alkoxylates in dilute aqueous solutions results in a greater than 100× increase in spread area as compared to water. This has resulted in enhanced wetting (Contact angles <1°) on non-polar substrates and flow-leveling benefits in many coatings formulations. An issue with the trisiloxane alkoxylates was the limited hydrolytic stability outside a narrow pH window (6.5-7.7) that has limited its acceptance in many coatings and inks formulations with operating pH’s in 8-10 range.

To address this serious pH stability issue, this presentation will introduce two new superspreading silicone surfactants that have enhanced hydrolytic stability of pH 6-11 respective of pH 6-8 stable. Their excellent performance as wetting additives in various coatings formulations will be discussed.

Karl-Heinz Kaesler*, S, Rajaraman, A. Lejeune, G. Policello, M. Leatherman

Momentive Performance Materials

Surface modification and characterisation of nano TiO₂ particles as an additive in a polyurethane clear coating

Surface modification and characterisation of nano TiO₂ particles as an additive in a polyurethane clear coating were investigated. For improvement of nano particles dispersion, and increasing interactions between nano particles and polymer matrix, the surface of the nano particles was modified with APS silane. Equivalent amount of APS for monolayer formation on the nano particles surface was determined by means of elemental analysis (CHN). The grafting of APS on the nano TiO₂ particles surface was characterised with TGA and FTIR techniques. Mechanical properties of coatings containing various amount of nano TiO₂ particles, were evaluated with DMA technique and tensile strength measurement. The light stability of coatings with different levels of nano particle has been tested in an accelerated QUV weather-o-metre. The results showed that surface treatment of nano TiO₂ particles with APS, improves nano particles dispersion, mechanical properties and UV protection of urethane clear coating.

Mojtaba Mirabedini*, M.J. Zohuriaan-Mehr, M. Sabzi

Iran Polymer and Petrochemical Institute, Iran

New polymeric dispersant technology for universal colorants

Due to legislative pressure to eliminate alkyl phenol ethoxylates from general use and the new restrictions on the VOC content of decorative coatings, the re-formulation of universal colorants has been a priority for specialist producers and paint manufacturers over the last 3-5 years. There is a continuing requirement for cost effective polymeric dispersants that can suitably replace the traditional technology. The paper describes the development of a new range of polymeric dispersants for this application field and the formulating approaches that can be used to combat the common issues of paint compatibility and tinter stability.

David Cartridge

Lubrizol Advanced Materials, UK

Silicone surfactants for aqueous coatings

Silicone surfactants (polyether modified oligosiloxanes) with various molecular weight and molecular composition have been synthesized and tested for substrate wetting properties and overall coating performance in aqueous coatings. Surface tension reduction, leveling, intercoat adhesion, foam stabilisation and recoatability have been evaluated in comparison with classic types of substrate wetting additives (polyether modified polysiloxanes, fluorosurfactants and acetylene glycol derivatives). Silicone surfactants provide a good balance of substrate wetting and leveling properties, together with a low level of foam stabilisation, and they are in many cases an environmentally friendly alternative to fluorinated surfactants.

Janos Hajas

BYK-Chemie, Germany

This paper has been cancelled

Relating performance to claims for antimicrobial coatings

With conventional coatings equipped with antimicrobial agents, designed to protect a paint film from spoilage in service, relating the claim to the effect seen is relatively straight forward. Durability and performance are easily modelled and field exposure can generate data in which the effects can be clearly observed. With coatings designed to produce hygienic benefits, the effects are less clear and the relationship between efficacy data, claim and demonstrable benefit can be complex and difficult to establish. This paper discusses the manner in which realistic claims can be established and how such an approach can help with the design of coating systems that address the control of hygiene in a number of end uses in a realistic and credible manner. The way in which supporting data can be generated and the manner in which field evaluations should be performed is discussed.

Peter Askew

Industrial Microbiological Service (IMSL), UK

Influence of the additives loading on fire retardant coatings

Intumescent fire retardant coatings reduce the flame spread and the fire risk through the formation of a voluminous char protective layer. WKI research focuses on the development of intumescent fire retardant coatings capable of providing sufficient char layer with enhanced mechanical properties by introducing specific additives without compromising the fire retardant performance. The influence of added additives on the fire retardant performance has been studied via lab scale fire testing. Char strength was determined according to a method developed by WKI. It was indicated that combinations of different additives have significantly enhanced fire retardant performance and the char strength.

Mohd Yusof Keton*, Dirk Kruse, Barbora Deppe

Fraunhofer Institute/WKI, Germany

Durability of an anti-microbial coating on a hydrophobic surface

This paper presents a demonstration of the efficacy, durability and longevity of an actively anti-microbial coating on a hydrophobic surface. Hydrophobic surfaces are largely non-stick when dry and are self-cleaning when wet. When augmented with an anti-microbial additive, the combined effects produce a coating with rapid biocidal efficacy and long lasting properties.

Allen Chasteauneuf

Nano Hygiene Coatings, UK

Oxime free anti-skinning agents

The best know and most widely used anti-skinning agent methylethylketoxime (MEKO) is a known class three carcinogen and as such will be in the first phase of testing in the REACH process. Based on the results of earlier testing it is possible that MEKO will be reclassified as class two, which will seriously restrict its usage. New Oxime free anti-skinning agents have been developed as effective alternatives to MEKO. Earlier alternatives to MEKO have often shown the required anti-skinning performance but have been unacceptable due to a negative impact on other film properties such as drying, colour and hardness development. The latest developments overcome these problems by balancing the requirements of anti-skinning against those of other film properties.

Andrew Mason

Rockwood Pigments, UK

Enhancing productivity in coil coatings

Sophisticated analytical instruments are vital for pursuing research in many areas of modern science and technology. Confocal imaging techniques provide detailed images of coating surfaces whilst multi angled spectrophotometers are ideal for measuring colour differences at various angles. In conjunction with each other these techniques have enabled Eastman to differentiate between coating additives and understand the effect that molecular weight of cellulose esters has on the level of metallic flake alignment in coil coatings. This understanding should enable coil producers to increase production through fewer rejects and reduce the need for re-coating whilst substantially improving metallic flake alignment.

Carlo Testa

Eastman, UK

Optimising the rheology of waterborne coatings: new non-ionic rheology modifier technology for reducing viscosity loss on tinting and improving sag resistance

Strongly tinted paints are growing in popularity world-wide. While the best overall performance is delivered by non-ionic associative rheology modifiers, coatings thickened this way often have excessive loss of viscosity and low sag resistance when tinted. A new technology for such thickeners offers significant improvements in these performance parameters.

Marie Bleuzen*, Dr Daniel Saucy, Barrett Bobsein

Rohm and Haas, France

Evaluation of chromate-based and chromium-free polyurethane primers for coil coated strip building and construction applications

Coil-coating systems involving the use of chromate-based pretreatments and primers are still widely used for building and construction applications. In the future, however, customers and/or legislation are likely to demand a switch to chromium-free alternatives. The aim of this study was to evaluate the protective capabilities of some chromium-free polyurethane (PU) primers that are already available commercially or that are presently undergoing development, and to identify products that may be acceptable alternatives to conventional chromium-based products. Different commercial chromium-free primer and Bayer and Corus in-house development Cr-free primer pigments were evaluated. The performance of each primer was evaluated by means of electrochemical impedance spectroscopy (EIS) and accelerated testing. EIS studies showed a clear difference between different primer systems and water permeability. The results of EIS studies are compared and contrasted with data generated using accelerated tests.

Siva Bohm1*, Pete Longdon1, Hefin Dafydd¹, Bernadette Gerhartz-Quirin², Beate Baumbach²

¹ Corus UK Ltd

² Bayer Material Science, Germany

New findings for nanosilica particles in UV coatings

The topics covered in this paper will include:

• •

  improvements of the nanoparticles for UV-curing plastic clear coats;

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  limitations for improvements of UV-curing plastic clear coats; and

• •

  additional benefits for nanocomposite containing UV-curing plastic clear coats.

  Marco Yann Heuer

  Nanoresins, Germany

The influence of nanoadditives on surface, permeability and mechanical properties of self-organised organic-inorganic nanocomposite coatings

Transparent and colourless nanocomposite coatings featured by high degree of self-assembly of the organic – inorganic matrix were prepared from functionalised organosilicon precursors and oligomeric diamine or triamine. Unmodified and chemically modified montmorillonite, bentonite, laponite or colloidal silica was used as coating nanoadditives, differentiating in the shape, size and origin. The concentration of nanoparticles in coatings was mainly units of percent. The influence of the kind and concentration of additives on surface properties (surface roughness, surface hardness determined from nanoindentation experiments or as the scratch resistance), on permeability and on mechanical properties (static and dynamic mechanical analysis) will be discussed.

Milena Spirkova*, Libuse Brozova, Adam Strachota, Jiri Kotek, Miroslav Slouf

Institute of Macromolecular Chemistry, Czech Republic

New concepts in matting agents

Silica technology is well known in the coatings industry as a base for efficient and universal to be used matting agents. Modern industrial coatings and new applications challenge the formulator to improve paint properties that are related to film surface or interaction with chemicals from the environment. This requires also matting agents with additional benefits. Furthermore, a matting agent interacts with other formulation components which raises the need to modify to avoid negative impact on film properties and processing of the liquid paint. In this presentation, new developed matting agents that fulfill these needs are presented.

Uwe Ferner

Grace, Germany

Organosilanes and sol-gel technology for optical coating applications

Higher performance coatings with improved visual quality while being environmentally compliant have become of prime importance in growing areas such as primers, automotive, architectural, and industrial maintenance applications. As such, the organosilane technology – alone or in combination with other materials as additives has proven to be effective at improving the performance of a variety of coating systems, owing to the unique ability of organosilane molecules to form covalent bonding between inorganic and organic compounds along with the inherent stability and flexibility of the siloxane bond. This paper will review the fundamentals of organosilane chemistry including sol-gel technology and its relevance to various coating applications, focusing onto optical properties.

Pierre Chevalier*, Ana Marques

Dow Corning, Belgium