GB787051A - Polyphenylol derivatives of olefinic aldehydes - Google Patents

Abstract

Polyphenylol condensation products are prepared by reacting, in the presence of an acid catalyst, a molar amount of an olefinic aldehyde of formula CnH2n-1CHO wherein n is an integer from 2 to 6, with at least three mols. of a monohydric phenol having one active nuclear position or with at least five mols. of a monohydric phenol having two or three active nuclear positions. The term "active nuclear position" is defined as the reactive positions on the ring of monohydric phenols, for example in phenol there are three active nuclear positions, i.e. the 2-, 4- and 6-positions. The compounds obtained by the process are tri- or penta- or heptaphenylols wherein three, five or seven of the phenolic nuclei are linked by one, two or three <FORM:0787051/IV (b)/1> groups. The compounds exist in isomeric forms according to the nature of the linking in the aldehyde residues and the phenol nuclei. When the phenol contains only one active nuclear position, e.g. 2 : 6-xylenol, only the triphenylol derivative is obtained and in this case one mol. of aldehyde may be reacted with three mols. of phenol. When the phenol contains two or three active nuclear positions a mixture of tri-, penta- and hepta-phenylols is obtained, the nature of the product depending on the ratio of phenol to aldehyde. Thus to obtain a yield which is high in triphenylol derivatives, ten mols. of phenol per mol. of aldehyde are required. Any monohydric phenol having at least one active nuclear position may be used, those specified being phenol, cresols, xylenols, mono- or di- or triethyl-, butyl-, amyl-, octyl- and nonyl-phenols and p-phenylphenol. Specified olefinic aldehydes are acrolein, methyl- or ethyl-acrolein, crotonaldehyde, alpha-hexenaldehyde and tiglic aldehyde. Specified acid catalysts are hydrochloric, sulphuric, phosphoric and toluene sulphonic acids, aluminium chloride and potassium bisulphate. The polyphenylols may be converted to epoxy compounds by reaction with epichlorhydrin in the presence of caustic soda and the epoxy compounds used to prepare thermosetting resins (see Group IV (a)). In examples: (1) phenol (5 mols.) and acrolein ( 1/3 mol.) were mixed and reacted in the presence of hydrochloric acid, the unreacted phenol was removed and a crude triphenylol derivative obtained; (2) as in (1) but acrolein (1 mol.) added dropwise to phenol (10 mols.); (3) as in (2) but using a ratio of 1 : 5 a mixture of polyphenylols was obtained; (4) as in (2) but using p-cresol (6 mols.); (5) 2 : 6-xylenol (3 or 6 mols.) and acrolein (1 mol.) were dissolved in toluene and reacted in the presence of gaseous hydrogen chloride to give the triphenylol derivative.ALSO:Polyphenylols (i.e. compounds containing three, five or seven phenolic nuclei linked by one, two or three -(CnH2n)CH< groups) prepared by condensing, in the presence of an acid catalyst, an olefinic aldehyde with a monohydric phenol (see Group IV (b)), may be reacted with more olefinic aldehyde or with a saturated aldehyde to produce thermosetting resins. Alternatively, the polyphenylols may be reacted with epichlorhydrin to give polyglycidyl ethers which may be converted to thermoset resins by heating, by contact with basic or acid catalysts, such as sodium hydroxide, amines or sulphuric acid, or by reaction with a polyfunctional organic compound. Specified polyfunctional organic compounds are polyols, such as ethylene glycol and glycerol, polyhydric phenols, polythiols, polycarboxylic acids and anhydrides thereof, such as phthalic acid, adipic acid, phthalic anhydride and maleic anhydride and polyamines.