Abstracts

BRIDGING THE GAP IN PERFORMANCE DEFICIENCY OF ECO FRIENDLY WATERBORNE COATINGS BY MAKING USE OF A NANOPARTICLE CONTAINING ADDITIVE

Marc Herold and Frank Tabellion
Bühler PARTEC GmbH, Science Park 2, 66123 Saarbrücken
Phone: +49 681 394 6550, Email: oxylink@buhlergroup.com


Eco-friendly waterborne paints and coatings already gained considerable interest and market shares compared to traditional solvent borne systems driven by stricter legislation as well as the general environmental awareness. Nevertheless waterbornes have well known limitation in overall performance compared to classical solvent borne systems.

An innovative concept based on metal oxide nanoparticle technology potentially improving waterborne coatings will be introduced. With a chemo-mechanical milling process particles with tailored surface properties were generated. A verall good compatibility of the particles with a broad variety of binders was observed. The particles improve the overall coating performance due to direct particle-to-resin interaction. This effect closely depends on the high degree of dispersion as well as on the high surface area of the nanoparticles. Good advantages in performance enhancement of water-based acrylic emulsion systems, PUDs and alkyds for different substrates will be presented. In particular the significant enhancement regarding MEK rub stability, drying time, blocking resistance and stability against humidity will be highlighted. Kinetic data of the swelling behaviour of the coatings in water will give further insight in the proposed mechanism of the additive interaction in the coating.

In conclusion a new approach by making use of nanoscaled particles will be presented offering the potential to alter the landscape of eco friendly waterborne coatings.

ELECTRO-ACTIVE MEMBRANES, ARTIFICIAL MUSCLES AND SOFT MACHINES

Emilio P. Calius(*)(1), Katherine Ngatai, Todd Gisby(2), Kit Wong(1), Iain Anderson(2)

Imagine active paintings and sculptures capable of life-like motions, air flow systems that are part of walls or ceilings, morphing shutters and vents, haptic feedback systems on any touch interface, electric motors not much thicker than a sheet of paper and silent power generators. These are some of the new possibilities that are being enabled by a class of electro-active polymers known as dielectric elastomers (DE).

A DE device is essentially a compliant capacitor consisting of a light and flexible dielectric, such as a silicone film less than 0.1 mm thick, sandwiched between compliant electrodes. When an electric field is applied the forces generated by charge attraction and repulsion produce dramatic shape changes. This shape change can excess 100%, and can take place in a small fraction of a second, making them equal or superior to natural muscle. In addition to being inherently light and pliable, DE are also silent, resistant to corrosion, and have few if any moving parts. Acting in reverse, they can exhibit large changes in their electrical properties when deformed by an external influence, which means that DE can provide sensing and electrical power generation as well as actuation.

Significant recent advancements include the integration of sensing and electronic circuit functions into DE to create truly smart materials. The recently invented dielectric elastomer switch provides order of magnitude changes in electrical resistance, and the possibility of digital computation using DE sheets. It has also been shown to be possible to create capacitors and diodes using patterned electrodes on DE membranes. But there are still important hurdles to overcome.

In the Living Sculptures and Soft Machines project we are using DE to inject the breath of life into art through motion. By shaping electrodes on assemblies of DE sheets, patterns of motion are created. And these motions can respond to external stimuli, leading to active artworks with rich behaviours. In this phase, the challenges have included growing the device size from ~0.1 m2 to ~1 m2, and achieving an unprecedented number of independently controlled actuation channels.

In this paper we will provide an overview of this and related projects, summarize research results, and discuss the state of the art in dielectric elastomer materials and devices.

(1) Industrial Research Limited, Brooke House, 24 Balfour Road, P.O. Box 2225, Auckland 1052, New Zealand
(2) The Biomimetics Lab, Auckland Bioengineering Institute, University of Auckland: Level 6, 70
(3) Symonds Street, Auckland 1010, New Zealand

(*) Corresponding author: Dr. Emilio P. Calius; e.calius@irl.cri.nz; +64-9-920-3100

FROM PAINTWISE™ TO PAINTCRETE™

Nasser Almesfer1, Graeme Norton2

PaintWise™ is a nationwide product stewardship programme for unused/unwanted paint and paint packaging, established by Resene in 2004 and owned by The Resene Foundation. The aim of PaintWise™ is to direct the materials collected under the programme to beneficial end uses.

3R Group assisted in the programme design and now manages and delivers its services. 3R is also the Programme Manager for PaintCrete Partnership, an innovation partnership between Resene, 3R and Fletcher Concrete & Infrastructure. The partnership was formed in 2006 to find suitable uses for recovered waste paint in “cementitious applications” (concrete); and many cubic metres of PaintCreteTM have been poured since!

Waterborne paint exhibits many desirable properties that are similar to polymeric concrete admixtures, which have been commonly used in the modification of cementitious applications for well over 70 years. These properties include improved rheology, strength, toughness and durability. These improvements are due to the polymer resins found in paint exhibiting similar advantages to polymers found in conventional polymeric admixtures.

An ongoing programme of work by PaintCrete Partnership has been underway in New Zealand to understand the properties of recovered paint as a polymeric admixture substitute to improve the fresh and hardened properties of concrete mixes. Performance-based laboratory trials have been conducted to establish potentially successful mixes, while also conducting commercial trials to replicate the lab-based results and obtain additional input from placing contractors. Performance-based procedures were adopted for the trials so as not to limit the development of PaintCreteTM since standard specifications can put prescriptive restrictions on new materials and methods, potentially inhibiting innovation.

This conference presentation will outline the PaintWise™ story and the progress of the PaintCrete Partnership.

Graeme, a director of 3R and the Programme Manager for PaintCrete Partnership has been on the journey throughout. Nasser, an honours graduate from University of Auckland’s Engineering School, is undertaking his PhD in GlassCrete™, a variant of PaintCrete™.

CHANGING FILM BIOCIDES: REDUCING THE ENVIRONMENTAL IMPACT FROM DRY FILM BIOCIDES IN DECORATIVE COATINGS

Kevin Roden
Regional Technical Manager, Asia Pacific, Thor Specialties
PO Box 3124, Wetherill Park 2164, Australia
Phone: 02 9725 1177, Fax: 02 9725 5677, Email: kevinr@thorchem.com.au


Dry Film Biocides are a necessary inclusion in decorative paints to protect them from unsightly surface growth of fungi and algae. Increasing the concentration of the biocides in the coating will extend the period of protection provided to the coating but will also increase the amount of biocide lost to the environment. The paper will discuss the loss of biocide from the coating due to a number of factors and show how protection of the biocide can keep it in the film longer. The decrease in the loss of the biocide extends the period of protection to the coating and at the same time lessens any potential environmental impact.

Kevin Roden graduated from the University of Sydney with a degree in Microbiology and Pharmacology.

He has had extensive experience in microbiological testing and has been employed as Manager for two consultant Microbiological Testing Laboratories and Quality Assurance Manager for a vaccine manufacturer.

Kevin was employed in 1991 by Thor Specialties Limited in the position of Technical Services Manager and established a NATA accredited Microbiological Testing Laboratory for evaluating the performance of biocides in industrial and personal care products.

He is currently Regional Technical Manager Asia Pacific, responsible for technical support to the Thor Specialties operating companies in the Asia Pacific region.

NEW ACRYLIC HYBRID TECHNOLOGY FOR SUPERIOR DURABILITY OF EXTERIOR COATINGS

Neil Unthank, Dow Coating Materials, Australia

The durability of an exterior coating is affected by many factors, such as climatic conditions, UV intensity, substrate conditions and quality of application, just to name a few. Even though 100% acrylic polymers today deliver excellent exterior performance, further improvements in properties including dirt pick-up resistance, colour and gloss retention, chalking and moisture resistance and film integrity can lead to longer lasting paints with lower environmental impact and better cost efficiency for asset owners. New acrylic hybrid polymer technology is demonstrating superior performance in properties such as these, under a range of exterior exposure conditions.

NEW ACTIVE BUILDING BLOCK FOR ROBUST IN-CAN PRESERVATION

Tim Dewhurst, Dow Microbial Control, Australia

Due to increasing restrictions on many traditional active ingredients used as in-can preservatives, the remaining choices decrease. At the same time, the development worldwide of environmentally more acceptable coatings (lower VOC, residual monomer restrictions, natural ingredients) can result in a higher susceptibility to microbial spoilage. The most frequently used active preservative ingredients however, are limited in their efficacy spectrum, speed of kill and/or chemical stability. This has led to the development of a new active building block, methyl BIT, for robust in-can preservation.

NEW OPEN-TIME BINDER FOR THE AUSTRALASIAN MARKET

Nuplex

The movement away from solvent borne alkyd trim enamels over the past 15 years has given the paint formulator numerous headaches, especially when attempting to achieve gloss and open time on par with traditional solvent based systems. The phenomenon of narrow open time window is in part exacerbated by the nature of acrylic emulsion technology.

In light of this, Nuplex has recently developed a novel binder designed to exceed the expectations of current waterborne enamel technology. This new polymer delivers a 20° gloss between 65-70% in pigmented systems and can give open times nearly three times greater than the market leading waterborne enamels at a significantly lower coalescent demand.

UNISPAR®: THE STARTING POINT OF HIGH PERFORMANCE DECORATIVE COATINGS

The use of UNISPAR® in coatings has evolved over the years as functional filler that enhances the product performances particularly in marine and protective coatings where durability is a major concern. With years of experiences that we have acquired through these Industries, we have successfully developed UNISPAR® for use in decorative segments where performance does matters.

This paper further described the clear advantages of UNISPAR® in comparison to commonly used soft minerals eg. calcium carbonate, hydrous kaolin and calcined clays. Being hard and angular in shape, UNISPAR® particles create a rigid packaging network to produce tough coatings that resist blistering, blooming or frosting that enables formulators to produce coatings with excellent abrasion properties for better stain and burnish resistance.