1889 – 1926: Inventions and patents
In 1889, the two sons of the company founder, Wilhelm and Heinrich Heraeus, took over the management.[11] Research and development was further pursued, and the physicist and chemist Richard Küch, a former school friend of the Heraeus brothers, joined the company in 1890. Küch's research resulted in the German Imperial Patent No. 63591 in 1891 for the gilding of platinum sheet, the first patent in the company's history. Küch then developed a process by which quartz glass could be obtained by melting rock crystal at around 2000 °C.[12][13]
The quartz glass produced by the company was almost entirely free of defects and was of outstanding purity. It is still used in medicine and is a highly sought-after material in manufacturing on account of its translucence and resistance to heat and acids. With the advent of ceramic colors, more platinum was needed for production processes, and Heraeus started supplying products to the electrochemical and plastics industries. As the company continued to expand, it needed new premises – so in 1896, the W.C. Heraeus Platinum Smelting Factory was established just outside Hanau, employing 40 people.[13]
Further experimentation in the platinum smelters’ laboratories resulted in a variety of inventions and new production processes. These included the production of pharmaceutical iron compounds, chemically pure hydrofluoric acid, rubidium, and caesium. Most production at this time still involved platinum, which was used in more applications due to its chemical and physical properties. As it is also highly resistant to acids and heat, platinum was also used to make instruments such as scientific tools, crucibles, and vessels used in chemistry and physics.[14]
As early as the 19th century, platinum had already been used in locking pins to hold false teeth in place. Platinum was also used to make filaments in light bulbs and non-corrosive electrical contacts in telephones. With the development of the tanning lamp in 1904, Küch and Heraeus are regarded as the inventors of the UV high-pressure lamp and pioneers of body irradiation with artificial light sources for medical light therapy. In 1906, Küch developed the standardized resistance thermometer made of platinum, the principle of which is still used today in cars and ovens.[15]
In 1902, Charles Engelhard (1867-1950), brother-in-law of the two Heraeus brothers, became representative of the group in the USA and founded the Engelhard Corporation, a company for refining platinum, gold and silver. In 1909, Heraeus was transformed from a general partnership into W. C. Heraeus GmbH. Richard Küch became a co-partner and one of three managing directors.[16]
One of the most significant technical innovations in metal processing is credited to Heraeus: the melting of metals under vacuum. Heraeus applied for a patent on this process on 12 January 1918 and was granted a German patent DE 345161.[17] Heraeus was subsequently granted British patent GB 138648, Swiss patent CH 89145, and several French patents on the process. For a short time, Heraeus set up an independent division dedicated to this technology, Heraeus Vacuumschmelze, which registered 84 German patents in 10 years.[18]
