Patent GB-788556-A (GB)
Title: Heat-curable resinous compositions containing glycidyl phenolic ethers and their method of manufacture
Inventor: FARNHAM ALFORD GAILEY
IPC: C08G59/06
Filed: 1955-04-01
Abstract: In the production of glycidyl polyethers from polyphenylols by reacting the polyphenylols with 1-3 mols. epichlorhydrin (or glycerol dichlorhydrin) per phenol group in the presence of alkali, the polyphenols are prepared by reacting a monohydric phenol, e.g. phenol or cresols, with an olefinic aldehyde, e.g. acrolein, ethyl acrolein, crotonaldehyde as described in Specification 787,051.  The Specification describes the production of four polyphenylols designated A, B, C and D.  A was obtained by reacting 2820 gs. (30 mols.) phenols containing 1.8 c.c. conc. HCl with 168 gs. acrolein added dropwise.  After the exothermic reaction had subsided the mixture was heated for 1 hour at 100 DEG  C., unreacted phenol was distilled off under vacuum and a reddish coloured liquid was obtained which solidified at room temperature.  Under similar reaction conditions (B) 15 mols. phenol were reacted with 3 mols. acrolein; (C) 6 mols. cresol were reacted with 1 mol. acrolein; (D) 6 mols. xylenol were reacted with 1 mol. acrolein.ALSO:Glycidyl polyethers of a polyphenylol having 2X+1 phenylol groups and X tervalent <FORM:0788556/IV (a)/1> aldehyde residues linking the phenylol groups, X being an integer from 1 to 3 and n being an integer from 2-6, the polyether having an epoxy equivalency of at least 1 and preferably above 2, are obtained by reacting the polyphenol with epichlorhydrin or glycerol dichlorhydrin in the presence of 1-3 mols. epichlorhydrin per phenol group in the presence of sufficient caustic alkali added in two stages, first to act catalytically in the etherification of the polyphenol and in the second stage to bind the chlorine released.  The polyphenols are obtained by reacting a monohydric phenol, e.g. phenol or cresol, with an olefinic aldehyde, e.g. acrolein, ethyl acrolein, crotonaldehyde as described in Specification 787,051 (see Group IV (b)).  The Specification describes the preparation of four polyphenylols designated A, B, C and D, which are used for the preparation of the glycidyl polyethers; (A) was obtained by reacting 2820 gs. (30 mols.) phenol containing 1.8 c.c. conc. HCl with 168 gs. acrolein added dropwise.  After the exothermic reaction had subsided the mixture was heated for 1 hour at 100 DEG  C., unreacted phenol was distilled off under vacuum and a reddish coloured liquid was obtained which solidified at room temperature.  Under similar reaction conditions (B) 15 mols. phenol were reacted with 3 mols. acrolein; (C) 6 mols. cresol were reacted with 1 mol. acrolein; and (D) 6 mols. xylenol were reacted with 1 mol. acrolein.  In examples: (1) 800 gs. polyphenylol A dissolved in 525 gs. alcohol were reacted with 2060 gs. epichlorhydrin in the presence of 703 gs. NaOH (50 per cent aqueous solution) added in 4 portions at 60-55 DEG  C.; after dissolving in toluene and washing and redistilling a light amber liquid was obtained having a viscosity of 500,000 centipoises at 25 DEG  C. and an epoxy equivalency of 3; (2) this product, mixed with a further amount of A and benzyl dimethylamine as curing agent, cured in one hour at 100 DEG  C.; (3) the product of Example (1) cured with 4,41-diamine diphenyl methane in 3/4 hour at 80 DEG  C.; (4) a glycidyl ether prepared by reacting B dissolved in ethanol with epichlorhydrin was mixed with 12 parts polyphenol B and the mixture gelled without catalyst in 40 minutes at 165 DEG  C. and in 15-20 seconds, when mixed with benzyl diethylamine; gels were also obtained with 4,41-diamine diphenylamine and diphenyl sulphone or diethylene triamine.  The preparation of glycidyl ethers from polyphenylols C and D are described in Examples (5) and (6); (8) a mixture of the polyether of Example (1) and the equivalent amount of polyphenol A was ball-milled with nylon flock and the mixture used to mould discs; (9) discs were also obtained by moulding a mixture of the polyphenols and (a) calcium stearate, whiting and asbestos flock; (b) clay and calcium stearate. Examples (10 and (11) illustrate the preparation of panels from laminated glass cloth impregnated with the polyethers and benzidine or diamine diphenyl methane as catalyst; Example (12) describes curing in presence of (a) phthalic anhydride; (b) adipic acid; and (c) a thiokol; (d) acrylonitrile and diethylene triamine.  The glycidyl polyethers are stated to be stable in the absence of acids, amines and bases by which they are cured to stiff gels.  They are reactable with polythiokols, polycarboxylic acids, polyamines, and polyhydric phenols to give hard resins; they may be mixed with fillers, e.g. wood flour, asbestos, cotton flock.