Patent GB-961894-A (GB)
Title: Process for the preparation of alkylated bisphenols
Filed: 1962-03-12
Abstract: In a process for the production of alkylated bisphenols by first condensing an aldehyde with a phenol and subsequently alkylating the bisphenol formed with an olefine, the water formed during the condensation reaction is removed from the reaction mixture by adding to the mixture the olefin to be used for alkylation, and distilling. An azeotropic mixture of water and the olefin distils over, and may be separated into two layers, and the olefin layer may be returned to the reaction mixture. When all the water has been removed, an alkylation catalyst is added to the reaction mixture and the alkylation of the bisphenol with the olefine is carried out in the conventional manner.  Phenols specified are phenol, cresols, xylenols and ethylphenols; aldehydes specified are glyoxal, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, formaldehyde, benzaldehyde, p-chlorobenzaldehyde, salicylaldehyde, chloroacetaldehyde, b -chloropropionaldehyde, crotonaldehyde, acrolein, glutaraldehyde, 2-ethylhexaldehyde, chloral and aldol; and olefines specified are 2,4,4,-trimethylpentene-2, 2, 4, 4-trimethyl-pentene-1, 2-methylbutene-1, 2-methyl butene-2, mixed amylenes, mixed hexenes, mixed heptenes, mixed octenes, mixed nonenes, cyclohexene, a -methyl-cyclohexene, cyclopentene, a -methyl cyclopentene, 4-methylcyclohexene, styrene, 4-methylstyrene, 4-ethylstyrene, 3-chlorostyrene and 2-methylstyrene. The molar ratio of the aldehyde to the phenol is in the range of 0.3-1.5 to 1, the condensation reaction temperature is 20 DEG -100 DEG C., and an acid catalyst such as sulphuric, phosphoric, p-toluenesulphonic or acetic acid is present during the condensation.  Alkylation catalysts specified are sulphuric acid, hydrochloric acid, p-toluenesulphonic acid, AlCl3, ZnCl2, SnCl4, H3PO4 and BF3.  The molar ratio of olefin to the phenol used is in the range of 1-3 to 1. The final product obtained in the process is a viscous oil suitable for use as a rubber antioxidant.ALSO:Alkylated bisphenol compounds suitable for use as antioxidants for rubber are obtained by condensing an aldehyde with a phenol to obtain a bisphenol, adding to the crude condensate thus formed an olefin, azeotropically distilling the mixture of the condensate and olefin to remove therefrom the water formed during the condensation reaction and then alkylating the dehydrated reaction mixture with an olefin in the presence of an alkylation catalyst. The phenolic starting material may be phenol, a cresol, a xylenol, or an ethyl phenol, mixtures of phenol with cresols being preferred.  The aldehyde may be formaldehyde, acetaldehyde, glyoxal, propionaldehyde, n- or iso-butyraldehyde, n- or isovaleraldehyde, benzaldehyde, salicylaldehyde, crotonaldehyde, acrolein, glutaraldehyde, 2-ethyl hexaldehyde, chloral, or aldol. In the case of a dialdehyde such as glyoxal the condensate contains four phenolic nuclei per molecule, and the expression "bisphenol" is defined to include such compounds. Specified olefins include amylenes, hexenes, heptenes, octenes, and nonenes. Tertiary alkenes such as di-isobutylene are preferred. Cyclohexene, 3-chloro styrene, or other cycloalkenes or aralkenes may be used.  The final product is obtained as a viscous oil.