Rapid growth in the 1950s and 60s

Thermoplastic Acrylic Lacquers, originally developed in the USA by du Font for both mass production coating and refinishing of cars, were introduced by Dulux Australia for GMH cars in 1960. This technology, at first exclusive to GMH Holden, established standards of gloss retention and colour choice previously not available.

Paint companies recognised the competitive advantages which these new polymer systems offered and several research and development laboratories were established. Some of these were quite large even by international standards, at least in proportion to the turnover of the companies (e.g. Dulux Research and Development Laboratory, Clayton, Victoria, 1960 grew to 120 staff) and eventually were able to sell their advances over the art internationally. Pilot plant facilities for technical service were established for spraying and stoving of cars and substantial capital was invested to modernise plants for acrylics.

Some valuable advances were made by Australians. Thus 'distortion resistance' of the film was improved by manipulating the polymer internally or substituting external plasticisers which reduced impact damage and etching by insects on the car surface.[134] Special acrylic recipes for car repairs were devised by incorporating an adhesion promoting co-monomer (dimethylamino-methyl methacrylate) in situ.[135]

Thermosetting acrylic enamels. As the advantages of acrylic lacquers became more apparent, car manufacturers who traditionally had used enamel topcoats, sought to match the appearance and durability of the former. In the fifties harder alkyd enamels incorporating melamine formaldehydes were devised, but by the mid-sixties the major companies were producing thermosetting acrylics for this market.

Between 1951 and 1971 Paints Division of ICI UK had evolved a departure from conventional processes based on the phenomenon that polymerisation in a non-aqueous, disperse phase led to higher molecular weight polymers with improved flowout and better durability. By 1967, however, adequate stability in mass production paint lines had not yet been attained. At that stage Dulux researchers in Melbourne invented a novel stabiliser which, in contrast to conventional surface active agents, was polymeric and hence could be tailored to be intimately associated with the polymeric paint particles.[136] It overcame the stability problem and the new non-aqueous dispersions were developed commercially for the car industry in the UK, Australia and USA. The joint technology package was licensed in Europe and the USA and Dulux earned over $A1.2 million in royalties overseas.

Thermosetting acrylics expanded from cars to refrigerators, washing machines, food tins and beverage cans. Taubmans developed and patented a special appliance enamel 'Araclad', (reg. trademark) based on a glycidyl methacrylate copolymer with an acid modified epoxy compound for these end uses.

Epoxy-based resins based on the reaction of bisphenol with epichlorhydrin had been researched in Switzerland in the late 1930s, but it was not until the late 1940s that commercial production of epoxy resins for paint commenced in the USA.

In the fifties and sixties Australian companies adapted these polymers to uses such as clear foodcan linings, drum coatings, primers for washing machiners, cars and car undercoats. One unique product of this type was Taubman's high performance enamel 'Epiclad' (reg. trademark).

Australian Academy of Technological Sciences and Engineering