Hans John

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Hans John 2016-12-06T05:35:21+00:00

Hanns
John
(1891-1942)

developed
aminoresins

The reaction of formaldehyde with urea, thiourea or melamine produces thermosetting resins known collectively as aminoplastics. (Resins formed from aniline with formaldehyde have been used for specialised electrical insulation but were not generally classified as aminoplastics.)

Resinous products prepared by heating urea with excess formaldehyde were patented by John in 1918. Pollak and Ripper in Austria developed clear liquid casting resins for the production of ‘organic glass’ called Pollopas in the early 1920s. Goldschmidt and Neuss in Germany and Ellis in USA experimented with hot press moulding compositions based on urea formaldehyde, but Rossiter of British Cyanides Co. Ltd. developed the first commercial moulding powder based n a mixture of urea and thiourea with formaldehyde in 1926. The possibility of a white or highly coloured thermosetting material which could be moulded using techniques developed for phenol formaldehyde (bakelite) was undoubtedly a powerful incentive.

The use of urea formaldehyde resins for impregnating cellulosic fibres to produce crease resistant fabrics was developed by Tootal Broadhurst Lee Co. Ltd. in 1926.

In the early 1930s resinous solutions for plywood adhesives were developed by I.G.Farben under the trade name Kaurit and by de Bruyne as Aerolite.

Resins derived from melamine and formaldehyde were patented by Henkel in 1935 and these were found to possess superior heat and moisture resistance, and thus found use for plastics tableware.

Decorative laminated sheet was envisaged by British Cyanides in 1924. Their use was pioneered by Formica in USA using thiourea materials in 1931 and melamine in 1938. Decorative laminates were used extensively on board the liner Queen Mary in 1935.