Patent GB-946087-A (GB)
Title: Resins containing urea and method for their production
IPC: C08L75/02
Filed: 1961-09-25
Abstract: Intermediates in the formation of thermoset condensation polymers are prepared by reacting urea with a diaromatic compound, such as diphenyloxide, diphenylmethane, dibenzyl, 1,1-diphenylethane, or 1,1-diphenylpropane, which contains an average of at least 1.5 halomethyl groups per molecule.  The dry products may be reacted together a reaction may take place in solution or dispersion in a liquid medium, e.g. water.  The products are said to have the formula: <FORM:0946087/C2/1> in which n is an integer from 2 to 4 and Y is oxygen, methylene, ethylene, ethylidene, propylidene or isopropylidene.  In an example 4,41-di-(chloromethyl)-diphenyl-oxide, urea and water were heated together at 85-95 DEG C. for 11.5 hours, and the precipitate filtered, washed and dried.  It was a snow white powder, beginning to melt at 180 DEG C. and polymerizing at 200 DEG C. with evolution of ammonia.ALSO:A condensation product of urea with a diaromatic compound having at least 1.5 halomethyl groups per molecule or a thermoset resin or a precursor thereof. In one embodiment of the invention 0.25-1 mol of urea is used per equivalent of halomethyl groups and condensation taken direct preferably under anhydrous conditions at at least 140 DEG C. to the thermoset stage. In another, 1-2 mols of urea are used per equivalent of halomethyl and condensation is performed e.g. at 60-100 DEG C. in solution or dispersion in a relatively inert medium, e.g. water to form an intermediate capable of being thermoset.  Suitable diaromatic compounds are diphenyloxide, diphenylmethane, dibenzyl, 1,1-diphenylethane, 1,1-diphenylpropane and halo and alkyl derivatives of these substances.  Fillers may be incorporated into the reaction mixture and the thermoset product prepared in a mould. The intermediates may also be set in a mould, or used as adhesives. They may be used as powders, or applied to a filler from a dispersion or solution e.g. by spraying followed by drying, the product-coated filler mass being subsequently shaped and cured.  In examples (1). 4,41-di(chloromethyl)-diphenyloxide, urea and water were heated together at 85-95 DEG C, and the solid product recovered by filtration. It polymerised further at 200 DEG C. with evolution of ammonia and became thermoset. (2) is similar the product being dissolved in dimethyl formamide and coated on to glass slides. A similar product was prepared using a mixture of five different chloromethyl diphenyloxides. (3) A product prepared by mixing urea powder with 4,41-di-(chloromethyl) diphenyloxide formed an infusible resin when heated at 225 DEG C.  (4) A solution of 4,41-di-(chloromethyl)-diphenyloxide and urea in a mixture of methanol and acetone was poured on to a glass wool mat which was dried and heated to cure the resin.  (5) 4,41-di-(chloromethyl)-diphenyloxide, tri-(chloromethyl)-diphenyloxide, tetra-(chloromethyl)-diphenyloxide, and mono (chloromethyl) diphenyloxide were dispersed with colloidal silica in water using two mixed surfactants.  Urea and water were added, the resulting emulsion poured over a glass fibre mat which was dried, and the coated mat then heated to cure the resin.  A number of other halomethylated aromatic compounds which are useful in the invention are mentioned.