Patent GB-1422410-A (GB)
Title: Process for the manufacutre of dispersions of thermosetting reaction products
IPC: C08G8/08
Filed: 1973-06-19
Abstract: 1422410 Aqueous phenolic resin dispersions HOECHST AG 19 June 1973 [19 June 1972 21 June 1972 14 May 1973] 29020/73 Heading C3R A water-dilutable aqueous phenolic resin dispersion is prepared in a 2-stage process comprising heating a mixture consisting of at least 1 substituted phenol having a functionality of 1- 2 and either (1) phenol (mixture A), or (2) at least one substituted phenol having a functionality of 3 (mixture B), or (3) phenol and at least 1 substituted phenol having a functionality of 3 (mixture C), with formaldehyde or a formaldehyde donor a non-ionic emulsifier and at least 1 basic nitrogen compound selected from ammonia, primary and secondary amines until a sample of the condensation product when withdrawn has a B-time of 6-15 minutes at 160‹ C., and the batch is then cooled to below 100‹ C. and the resulting water-in-phenolic resin dispersion is mixed with water and a protective colloid in a second stage and agitated mechanically until a phase inversion has taken place, and the resulting phenolic resin-in-water dispersion is further condensed by heating, under a sample when withdrawn has a B-time of 30 seconds to 10 minutes at 160‹ C., and then the batch is cooled whilst stirring, the mixture A, B or C being employed in such amounts that the average functionality of the sum of the phenolic compounds in mixture A, B or C relative to HCHO is 2À1 to 2À8, the amount of HCHO being such that the molar ratio of HCHO added to the sum of the phenolic compounds in mixture A, B or C is 0À9-1À5 : 1, and the basic nitrogen compound being used in amount of 5- 50 mol per cent relative to the total weight of phenols in mixture A, B or C. In an embodiment mixture A, B or C is prepared in a first step by reacting 1 mole of styrene or styrene derivative with either a molar excess of phenol (for mixture A), or a molar excess of a substituted phenol having a functionality of 3 (for mixture B), or a molar excess of phenol and a substituted phenol having a functionality of 3 (for mixture C) in the presence of 2-5% wt. of oxalic acid by heating to 150-160‹ C. until 95% of the styrene has reacted. In general suitable substituted phenols having a functionality of 1-2 are p-tert butyl phenol, α- and/or #-phenylethylphenol, p-phenylisopropylphenol, p-isopropenylphenol, and o- and/or p-cresol. Suitable substituted phenols having a functionality of 3 are m-cresol, m-pentadecenylphenyl and 3,5- dimethylphenol. Suitable styrene derivatives are α-methylstyrene and p-bromostyrene. Suitable HCHO donors are paraformaldehyde and hexamethylenetetramine. The preferred basic nitrogen compounds are ammonia, dimethylamine, morpholine or diethanolamine. The preferred non-ionic emulsifiers are addition products of ethylene oxide and p-n-nonyl phenol or of ethylene oxide end polypropylene glycols. Preferred protective colloids are polyvinyl alcohol saponified to 88 mol per cent and hydroxyethylcellulose. Examples are given for the preparation of the dispersions. Uses.-As binders in the manufacture of lacquers and coatings, mineral wool slabs, hard paper and hard cotton or glass fabrics, battery separators, air and oil filter papers abrasives, curable moulding materials, e.g. brake limings, plywood, chipboard and hardboard.