There are a range of applications where a ceramic thin film or coating on a metal part would be of benefit. There are a limited number of cost-effective processes for producing such a coating, particularly on complex shaped parts. This paper reports progress in materials and processing over the past ten years. The pulsed pressure processing method (PP-MOCVD) eliminates thermally driven flow effects and produces a uniform molecular arrival rate over the surface of the part. SEM images show the uniformity of the coating over the macro and micro scale. A new type of flow modeling was used to describe the deposition process. The model was used to perform a hypothetical reactor design investigation for coating a batch of parts to a prescribed film thickness and uniformity at a required production throughput. The experience to-date indicates that the PP-MOCVD system can provide a high quality ceramic coating in production with low tool complexity and accessible cost.

With the continuing drive toward development of coatings with minimal VOC levels, formulators are facing challenges with additives ranging from rheology modifiers to dispersants and beyond. We will show how a new approach to HEUR rheology modifier design, ACID SUPPRESSION™ Technology, is enabling the development of both mid and high shear viscosity-builders that meet the rheological requirements of minimal- VOC coatings, while simultaneously addressing additional formulation needs. New formulations must also deliver hiding and stability, and thus the dispersant becomes an ever more important component. As a result, there is a need for more finely tuning the dispersants in formulations.

This paper will describe results of research into resolving a number of perplexing problems for pigment research and development chemists such as:
A high performance blue shade violet pigment suitable for the automotive industry achieved by mixed crystal phase pigments.
The ability to produce organic pigments that can be easily dispersed without any loss of performance characteristics. A novel patented method of producing a range of organic pigments that can be incorporated by simple slow speed stirring alone will be discussed.
A new delta crystal form of PB60, Indanthrone blue, which has all the characteristics of the alpha crystal but is redder in shade.
New Generation Pearl Pigments achieved by a novel multi-layer coating process. The results of intensely coloured, highly opaque pearlescent in all four quadrants of colour space will be presented, along with the potential use of magnetic fields during application of the coating.

Dry film biocides are an integral component of coatings and have been so for many years. Changes to regulations and consumer desires have meant ongoing demands for biocides with lower toxicity and improved performance characteristics.

There is now a greater desire for harvesting rain water and water that was traditionally fed down drains to the creek and river systems is now being collected for use in gardens and also for drinking. Much of this water runs across coated surfaces on its way to the collection tank and there is concern about what might be picked up by the water on its journey.

This paper will look at techniques being developed to measure the biocide content coming from fresh and aged films containing various biocide actives and discuss one technology designed to reduce leaching from the film.

Results will be presented to show the concentration of different biocide actives leached into the water and the effect of the new technology on reducing the amount of biocide lost from the film. The results will be compared with drinking water standards to determine if a problem exists, and if so, what are the requirement on paint producers to ensure the safety of their customers and the environment.

Waterborne resins offer an attractive alternative for the traditional alkyd resins used in interior and exterior trim paints. Unfortunately some of the application properties of waterborne binders are not yet up to standards. Especially properties such as the open time and wet edge time of the applied paint need to be improved in order to obtain the same high quality finishing that was possible with conventional solvent-borne trim paint. Currently, both alkyd emulsions and acrylic polymer dispersions are two frequently used technologies used in the formulation of waterborne VOC-compliant coatings. Coatings based on alkyd emulsions exhibit advantages over those based on acrylic dispersions in terms of gloss, brush-ability, open time, flow and leveling, hiding per coat and adhesion. Advantages of acrylic dispersions over alkyd emulsions include quick drying, durability, non-yellowing, non-embrittling, and non-chalking. Coating formulators therefore often combine acrylic dispersions with alkyd emulsions. The main advantage formulators are looking for are improved film forming properties due to the presence of alkyd moieties, which typically have a low glass transition temperature. However, the presence of the alkyd and especially the presence of substantial quantities of surfactant used in the production of the alkyd emulsion, results in some critical problems, such as soft films (causing dirt pick-up and poor block resistance). Another problem that may be encountered is the occurrence of phase separation between the binders due to incompatibility. Therefore the use of alkyd-acrylic composite binders, prepared by means of mini-emulsion polymerization offers interesting perspectives. In this paper the development and optimization of such hybrid polymer dispersions is discussed.

Coating technologies are rapidly advancing, producing thinner layered films with faster cure times and functionalised substrate adhesion. The surface properties of these coatings systems have a strong influence on their overall performance and service life. Properties such as surface morphology, microstructure and mechanical properties are important for understanding coating integrity and enabling accurate failure prediction.

However, these thinner coatings bring new challenges in mechanical property measurements where pull off tests are difficult, substrate effects become apparent and geometry specific samples are difficult to prepare.
Nanoindentation is a technique used to measure the mechanical properties of small scale materials. Recent technological adaptations have enabled simultaneous measurement of forces and displacements at nanoscale resolution to be measured using a small diamond indentation probe which penetrates the coating. This technique allows nanomechanical and tribological measurements to be made without any prior sample preparation on coatings of varying thicknesses and compositions.

This presentation will show recent results from studies on polymer coatings ranging from several nanometres to microns in thickness. Delamination and adhesion forces were measured using a nanoscratch function and used to predict failure mode, observe brittle cracking and ductile pile-up features. Hardness and modulus measurements as a function of coating depth were taken with nanoindentation tests over extended time periods to enable accurate prediction of curing times and reduce unnecessary holding time in batch production. Finally nanowear tests showed both wear resistance and coating durability in a quantifiable manner and completed the coating test sequence.

Using the most recent equipment and analysis methods, the measurement of the mechanical properties of polymer films and coatings is now achievable for accurate and fast durability and failure predictions.

Plants and trees produce a range of chemical compounds that play specific roles in the function and protection of the plant. Some of these compounds can be obtained in reasonable yield on extraction of harvested plants, seeds or processing residues. Scion, a Crown Research Institute, has a background in the production, processing and isolation of materials from plants and trees. Within Scion there are several research streams investigating the isolation, characterisations and utilisation of by-products and materials from crops, forestry and processing wastes for use in various industrial applications. Some materials of interest include polyphenolics such as lignin and condensed tannins. The inherent chemistry present in polyphenolics provides opportunities for these materials to be substituted into a range of products with potential to provide a similar role as they play within plants. Discussed are some recent examples of bioderived materials including polyphenolics being used in paint and coating formulations.

Historically, waterborne paints have been growing in volume since the late 1950’s with the advent of micro-dispersed polymer particles in water produced by the emulsion process.

The early polymers were based on vinyl alcohol or vinyl acetate homopolymers which were relatively large particle size and sensitive to water limiting their use to interior low demand decorative applications.

Acrylic polymers were well known for their exterior durability in solvent-borne systems, and soon trialled with the emulsion process to produce durable waterborne polymers. Their high molecular weight being in the region of 10 to 100 times that of their solvent- borne counterparts resulted in superior resistance to UV degradation and erosion.

Improvements in emulsion polymerization have lead to reduced particle size polymers and much lower levels of water sensitive materials in the resultant dry paint but until recently, the level of water resistance has not been sufficient to completely displace some solvent-borne systems in more demanding applications.

Medium density fibreboard (MDF) is one of the substrates suffering from poor water resistance properties due to the hydrophilic nature of the wood fibres but more importantly due to the nitrogen functional polymers employed to bind those fibres.

MDF producers constrained by raw material cost, processing needs and competitive pressures have found that Urea Formaldehyde (UF) resins combined with various waterproofing additives are the only commercial option. Future low cost polymer developments may eventually displace UF’s but it is more likely that increasing consumer and legislative resistance to formaldehyde levels will drive change. Until then UF bound MDF board is an important substrate for paint manufacturers.

One of the most important steps in the manufacturing of mill bases, pigment concentrates and other pigmented systems is the dispersing process. During this process the pigments which are insoluble solids, need to be distributed within the liquid medium in order to be wetted, effectively dispersed mechanically and finally stabilized to prevent the re-agglomeration of the pigments. Conventionally nonyl phenol ethoxylates are used as wetters and sodium polyacrylates as stabilizers.

In this paper, the work done involves the replacement of nonyl phenol ethoxylates with more environmentally friendly wetters that have excellent compatibility with no negative impact on coating performance. These green wetters from Cognis were found to synergistically increase the performance of dispersing agents based on sodium polyacrylates relative to the existing wetters without affecting the properties of the paint or in fact improving the properties in some cases such as gloss. Also some of these wetters have a defoaming property,

One of the most expensive steps in the manufacturing of paint is the preparation of mill bases. As mentioned above the improvement of the performance of the sodium polyacrylate based dispersing agent by Cognis new green wetters has lead to the increase in pigment loading by 10 – 20 % (depending on the pigment type) in the mill base. This increase in pigment loading allows for the preparation of more concentrated mill base and hence more paint.