Patent GB-1476802-A (GB)
Title: Process for the manufacture of curable and thermosetting  synthetic resins containing boron
IPC: C08G8/28
Filed: 1974-08-02
Abstract: 1476802 Thermosetting synthetic resin containing boron HOECHST AG 2 Aug 1974 [28 Sept 1973 19 April 1974] 34205/74 Heading C3R A process for the manufacture of a curable and thermosetting synthetic resin containing boron is characterized in that (a) phenol by itself, or a mixture of phenol and at least one substituted phenol which has a hydrogen atom at least in the O-position on the phenol nucleus, the substituted phenols being selected from C 1 -C 30  alkyl phenols, C 5 -C 10  cycloalkylphenols, C 2 -C 30 -alkenyl -phenols, C 5 -C 10  cycloalkenylphenols the cycloalkyl and cycloalkenyl radicals being of mono- or bi-cyclic structure aryl-substituted phenols and aralkylsubstituted phenols with one aromatic ring in the substituent and halogen-substituted phenols (b) at least one esterifiable boron compound (c) at least one primary and/or secondary aliphatic saturated C 2 -C 5  monoalcohol and (d) formaldehyde paraformaldehyde and/ or trioxane are reacted conjointly in the presence of an excess of (d) or stepwise with removal of the water of reaction and in the conjoint reaction of (a), (b), (c) and (d) the water is removed by azeotropic distillation in the presence of a water-entraining agent, with heating to a maximum of 110‹ C., and the further volatile constituents are thereafter removed at 110-150‹ C. under reduced pressure and heating is discontinued when the resulting synthetic resin has reached a B-time of 30 seconds to 6 minutes at 160‹ C., or, in the case of the stepwise reaction, (I) first components (b) and (c) are reacted in a molar ratio of 1 : 1 to 1 : 4 to give an aliphatic boric acid ester (bc), in the presence of a water-entraining agent, where necessary, or an aliphatic boric acid ester (bc<SP>1</SP>) having an alcohol radical of primary and/or secondary aliphatic C 1 -C 5  monoalcohol is employed, or (Ia) first components (b) and (c) are reacted in a molar ratio of 1 : 1 to 1 : 4 to give an aliphatic boric acid ester (be) in the presence of component (a), where necessary in the presence of a water-entraining agent, at 120‹-150‹ C., components (a) and (b) being present in a weight ratio of 100 : 5 to 100 : 20, and (b) being calculated as boron oxide, and (II) the aliphatic boric acid ester (be) from stage (I) or the employed aliphatic boric acid ester (bc<SP>1</SP>) is reacted in the presence of components (a) and (d) at 95‹-100‹ C., the molar ratio of components (a) and (d) being from 1 : 1 to 1 : 2À5, components (a) and (be) or (bc<SP>1</SP>) respectively being present in a weight ratio of 100: 5 to 100 : 20, component (be) or (bc<SP>1</SP>) being calculated as boron oxide, or (IIa) the reaction mixture from stage (Ia) is reacted with component (d) at 95‹-100‹ C., the molar ratio of (a) to (d) being from 1 : 1 to 1 : 2À5, or (IIb) the boric acid ester (be) or (bc<SP>1</SP>) from stage (I) is reacted with a reaction product of components (a) and (d), which possesses at least one methylol group, per mol of component (a), in the O- position, by heating to 60‹-120‹ C., and (III) the batches from (II), (IIa) or (IIb) are heated under reduced pressure to 110‹-150‹ C., and the heating is discontinued when the resin obtained reaches a B-time of 30 seconds-6 minutes at 160‹ C. Component (a) may also be employed as a semi-formal in steps I, II and III or in the one-step process. The reaction may be carried out in the presence of an inorganic or organic acid of pK less than 2À5. The velocity of the reaction of the substituted phenol with HCHO is preferably 40-150% that of the unsubstituted phenol wilh HCHO. Suitable substituted phenols (a) are m-cresol, 3,4-, 3,5- and 2,5- dimethylphenol, m-ethylphenol, m-propylphenol, m-butylphenol, o- and/or pn- and/or isopropenyl - phenol, o- and/or pallylphenol, phenylphenol, o-and/or pa-and/or -#-phenylethylphenol or phenylisopropylphenol or methyl phenylethylphenol, technical alkylation products of olefins and phenols. Suitable components (b) are boric acid, boron trioxide, boron trichloride or trifluoride, and the reaction product of boric acid and acetic anhydride. Suitable component (bc<SP>1</SP>) is trimethyl-borate. Preferred components (c) are isobutanol and n-butanol. Suitable water-entraining agents are toluene, benzene and xylene. In the examples resins are prepared as above using as component (a) phenol alone and in admixture with phenylethylphenol; as component (ad) dimethylolphenol; as component (b) or (bc<SP>1</SP>) boric acid, boron oxide or trimethyl borate, as component (c) isobutanol or n-butanol; and as component (d) paraformaldehyde, trioxane or a butanol solution of formaldehyde. Uses:- Binders for compression-moulding compositions, resin-impregnated papers and brake linings.