Question:
Who was the chair of Industrial Union of Chemicals, Glass and Ceramics in May, 1947?

Context:
 Edith Weber is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1980 to Jan, 1989. 
 Nomen nescio is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1989 to Jan, 1991. 
 Max Reitersleben is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1946 to Jan, 1950. 
 Werner Oertelt is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1967 to Jan, 1980. 
 Horst Willim is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1952 to Jan, 1958. 
 Hans-Joachim Winkler is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1965 to Jan, 1967. 
 Rudolf Höppner is the chair of Industrial Union of Chemicals, Glass and Ceramics from Jan, 1959 to Jan, 1965.

Answer:
Max Reitersleben