Patent GB-578643-A (GB)
Title: Improvements in or relating to the production of urea-aldehyde compositions
IPC: C08L61/24
Filed: 1944-05-12
Abstract: A synthetic resinous composition comprises a mixture of 15-50 per cent by weight of hydrolysed interpolymer of a vinyl organic ester and ethylene with 85-50 per cent by weight of urea-aldehyde resin. The term urea is defined as including substances such as melamine, thiourea, ethylene urea, sym-dibutylurea, monopropylurea, monolaurylurea, sym.-trimethylmelamine, dicyandiamide, guanidine, biuret, and sym-dimethyl guanidine. Suitable aldehydes are formaldehyde, acetaldehyde, isobutyraldehyde, valeryl aldehyde, capryl-aldehyde, acrolein, crotonaldehyde, tiglic aldehyde, furfural, benzaldehyde, salicylaldehyde, anisaldehyde, perilla aldehyde, or cyclohexane carbonal.  Suitable vinyl organic esters are vinyl formate, vinyl acetate propionate, isobutyrate, laurate, oleate, stearate, feroate, benzoate, a -naphthoate, salicylate or cyclohexane carboxylate.  The hydrolysed interpolymers may have a molar ratio of ethylene to vinyl ester between 25 : 1 and 1 : 25, preferably between 5 : 1 and 12 : 1.  Preferably, ethylene and vinyl acetate are copolymerized at about 100 DEG  C. and at an ethylene pressure below 1000 atmospheres in the presence of a peroxide.  Hydrolysis which may be partial or complete, is carried out under acid or alkaline conditions in solution in an alcohol or alcoholhydrocarbon, e.g. toluene mixture.  The hydrolysed interpolymers may be added to the ureaaldehyde resin as powder, granules, flakes, films or solution. The urea-aldehyde resin may be solid or in solution.  Solids may be mixed by ball milling. For mixing in solution, water is preferred. Dioxane, methanol, ethanol or dimethyl-formamide may also be employed.  The hydrolysed interpolymer may be added to the components of the urea-aldehyde resin before reaction.  The products are mouldable with or without catalysts or may be used as binding agents, textile modifying agents, adhesives, or baking enamels.  Catalysts which may be used are ammonium sulphate, benzoic acid, b -bromohydrocinnamic acid or zinc sulphate.  Opacifiers, pigments, dyes, antioxidants, lubricants, plasticisers, inorganic fillers, or polymers such as phenol-formaldehyde, or sulphonamide - formaldehyde resins, nylons, polyvinyl ketals or acetals, cellulose derivatives, alkyd resins, polystyrene, polymethylmethacrylate, lignin, sawdust or a -cellulose may be added to the compositions.  Coloured products of great brilliance may be produced.  Colouring matters are preferably added during blending, e.g. in the ball mill.  In the examples, a ureaformaldehyde resin solution is used prepared by adjusting a mixture of urea and formaldehyde to pH 9.15 with disodium phosphate, refluxing for 1 hour, cooling, adjusting pH to 5.5 with formic acid, adding more urea, refluxing for another 20 minutes, cooling and again adding urea to give a total molar ratio of formaldehyde to urea of 1.7 : 1.  In examples I and II, this solution is mixed with a completely hydrolysed ethylene/vinyl acetate interpolymer having an ethylene: vinyl acetate molar ratio of 10.7 : 1 using a hexylphenol-ethylene oxide condensation product as dispersing agent. The mixture is dried, and ball-milled with b -bromohydrocinnamic acid and aluminium stearate to yield a powder which may be moulded at 155 DEG  C. and 2800 lbs./sq. in. for 8 minutes.  The hydrolysed interpolymer is prepared by mixing under nitrogen in a pressure vessel, vinyl acetate, oxygen-free water, the sodium salt of sulphonated white oil and benzoyl peroxide, and admitting ethylene to a pressure of 540 atmospheres.  The pH is adjusted to 2.9. Temperature is 73-75 DEG  C.  Product is steam distilled which coagulates the interpolymer and removes impurities.  Wash and dry on a rubber mill.  Dissolve in benzene, add alcoholic KOH, and reflux. Filter, cool slowly with vigorous agitation, wash with alcohol and water and dry.  A slurry of the resinous mixture in water was used as an adhesive for plywood.  Example III is similar, but employs an interpolymer having a molar ratio of ethylene: vinyl acetate of 3 : 1.  Example IV employs an interpolymer with an ethylene: vinyl acetate ratio of 1 : 1 : 3 dissolved in ethyl alcohol.  The products may be moulded to kitchen utensils, tableware, drinking cups, baking dishes, toilet articles, bathroom fixtures, fountain-pens, mechanical pencils or electrical equipment. Specifications 571,826, 575,260 and 575,689 are referred to.  The Specification as open to inspection under Sect. 91 includes also the use of hydrolysed interpolymers of a vinyl ester with any polymerizable unsaturated compound and mentions methyl, butyl octyl and lauryl acrylates, isobutyl and ethyl methacrylates, ethyl a -chloroacrylate, octyl a -bromoacrylate, lauryl a -iodoacrylate, dimethyl maleate, dioctyl fumarate, dipropyl fumarate, diisobutyl fumarate, acrylonitrile, methacrylonitrile, a -chloroacrylonitrile, methacrylamide, N-butyl methacrylamide, N-octyl-methacrylamide, N-vinyl maleimide, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene dichloride, trichlorethylene, isobutylene, propylene, styrene, tetrafluoroethylene, monovinyl ketone, and methyl isopropenyl ketone.  This subject-matter does not appear in the Specification as accepted.