Patent GB-1508895-A (GB)
Title: Process for the manufacture of a synthetic resin containing nitrogen and boron
IPC: C08G8/28
Filed: 1975-04-17
Abstract: 1508895 Synthetic resins containing boron and nitrogen HOECHST AG 17 April 1975 [18 April 1974 20 March 1975] 15926/75 Addition to 1474753 Heading C3R A synthetic resin containing nitrogen and boron is manufactured by a process wherein (a) phenol or a mixture of phenol and a bisphenol and/or at least one substituted phenol having a hydrogen atom at least in the ortho-position on the phenol nucleus capable of reacting with formaldehyde, the substituted phenol being selected from C1-C30-alkylphenols, C5-C10- cycloalkylphenols, C2-C30-alkenylphenols, C5- C10-cyoloalkenylphenols, the cycloalkyl and cycloalkenyl radicals being mono- or bi-cyclic, aryl-substituted phenols and aralkyl-substituted phenols with one aromatic ring in the substituent, halogen-substituted phenols and amino-substituted phenols, (b) at least one esterifiable boron compound, (c) at least one primary and/or secondary aliphatic saturated C2-C5- monoalcohol, (d) hexamethylenetetramine and (e) formaldehyde and/or paraformaldehyde and/or trioxane are reacted conjointly, using an excess of (e), or stepwise, with removal of water by azeotropic distillation in the presence of a waterentraining agent, and in the conjoint reaction the water of reaction is removed by said azeotropic distillation, with warming to a maximum of 110‹ C., and optionally the further volatile constituents are thereafter removed by heating the molar ratio (b) : (d), calculated as boron in the case of (b) and as nitrogen in the case of (d) being from 1 : 0À5 to 1 : 1, and the molar ratio of (a) to (e) being from 1 : 1 to 1 : 2À5, and heating is discontinued as soon as the resulting synthetic resin has reached a melting point above 75‹ C. but below 170‹ C. Components (a) and (b) may be used in a weight ratio ranging from either 100 : 8 to 100 : 20 or from 100 : 20 to 100 : 40. The stepwise reaction may be carried out by first (I) eitherreacting components (b) and (c) in a molar ratio of 1 : 1 to 1 : 4, (b) being calculated as boron, at 120-150‹ C. to give an ester (bc), optionally in the presence of (a), and in the presence of a water-entraining agent, or a preformed aliphatic boric acid ester (bc<1>) is used, then (II) reacting the reaction mixture from step (I) at 95-100‹ C. with components (d) and (e) and also with (a) when not used in step (I), then (III) either heating under reduced pressure with removal of the volatile constituents at 110-180‹ C. or subjecting the reaction mixture from step II to azeotropic distillation for removal of the water of reaction, with recycling of the water-entraining agent and continuing heating at 120-140‹ C. until the resin being soluted has the desired melting point. Suitable components (b) are boric acid, boron trioxide, boron trifluoride or trichloride, boric acid trimethyl ester and reaction products of boric acid and acetic anhydride. Preferred components (c) are isobutanol and n-butanol. Suitable water-entraining agents are benzene, toluene and xylene. Oxalic acid may be used as an esterification catalyst in step (I). In the examples non-thermosetting synthetic resins are prepared by the stepwise reaction by first reacting at 150‹ C. boric acid and iso-butanol in the presence of phenol using toluene as water entraining agent and oxalic acid as catalyst, with azeotropic removal of water, then reacting the resulting mixture with hexamethylenetetramine and paraformaldehyde at 95‹ C., then distilling off the solvent in vacuo at a temperature of 120-180‹ C. In a similar example the phenolic component used is a mixture of phenols prepared by heating styrene, phenol, oxalic acid and tetrabromide bisphenol A. Uses.-As binders for compression-moulding compositions, resin-impregnated papers and brake linings, in combination with other reactive synthetic resins.