Patent GB-550280-A (GB)
Title: Manufacture of rubber-like materials
IPC: C08F236/16
Filed: 1941-03-24
Abstract: 550,280. Synthetic rubber ; resinous polymerization products. DU PONT DE NEMOURS & CO., E. I. March 24, 1941, No. 3945. Convention date, March 22, 1940. [Class 2 (iii)] Rubber-like materials of improved resistance to mineral oils are obtained by interpolymerizing, e.g. in aqueous emulsion or in an inert solvent, butadiene -1 : 3 or its 2 -chloro derivative with a minor proportion of an ester derived from a monohydric aliphatic nitroalcohol and an aliphatic α : #-unsaturated carboxylic acid. A polymerization catalyst such as hydrogen peroxide, benzoyl peroxide, sodium peroxide, barium peroxide or ammonium persulphate may be employed. Examples relate to the interpolymerization of (1) 17.5 parts of butadiene with 14 parts of 2-nitro -2- methylpropyl methacrylate in an aqueous emulsion containing sodium oleate, sodium hydroxide, ammonium persulphate, a sulphonated naphthalene - formaldehyde condensation product and carbon tetrachloride by heating the emulsion in a sealed vessel for 65 hours at 40‹C. with constant agitation, adding an aqueous dispersion of phenyl - 1 - naphthylamine and diphenylamine and coagulating with brine and alcohol; the emulsifying agents may be replaced by N - y - hydroxylpropyl - C - cetyl-betaine ; (2) 35 parts of butadiene with 15 parts of 2 - nitro - 2 - methylpropyl acrylate in an aqueous emulsion containing N - γ - hydroxypropyl - C - cetyl - betaine, a sulphonated naphthalene - formaldehyde condensation product, acetic acid, ammonium persulphate and carbon tetrachloride by heating the emulsion in a sealed vessel for 10 hours at 60‹C. with constant agitation, adding a dispersion of amines as in (1) and coagulating by adding ethyl chloride and saturated brine ; (3) 60 parts of 2 - chlorobutadiene - 1 : 3 with 15 parts of 2 - nitro - 2 - methylpropyl methacrylate in an aqueous emulsion containing sulphur, the sodium salt of the sulphated ester of oleyl acetate, and a sulphonated naphthaleneformaldehyde condensation product by maintaining the emulsion for 1¢ hours at 40‹C., adding a dispersion of amines as in (1) and coagulating with brine and alcohol;' (4) 60 parts of 2 - chlorobutadiene - 1 : 3 with 15 parts of 2 - nitro - 2 - methylpropyl methacrylate by heating for 5 hours at 80‹C. in carbon tetrachloride containing benzoyl peroxide, washing the solution with alcohol and milling the product with phenyl - 2 - naphthylamine between hot rolls. Other specified emulsifying agents are the sodium sulphato esters of the alcohols obtained by hydrogenation of coconut oil or sperm oil, sodium ligninsulphonates, cetyl pdimethylaminobenzoate methosulphate, cetyltrimethyl - ammonium bromide, cetyl - methylpiperidinium methosulphate, oleylamidoethyl-diethylamine acetate, N-stearylbetaine and p - stearamidophenyl - trimethylamine methosulphate. The carbon tetrachloride may be replaced by dioxane, ethylene dichloride, acetone, butyl acetate, benzene or toluene. The nitroalcohol esters may be derived on the one hand from 1 : 2 - , 2 : 1 - or 3 : 2 - nitrobutanol, 1 : 2-, 2 : 1-, 2 : 3- or 3 : 2 - nitropentanol, 2 : 3- or 3 : 2-nitrohexanol, 3 : 4 - nitroheptanol, 5 : 4 - nitrooctanol, 2 - methyl - 2 - nitropropanol, 3 - methyl - 1 - or 3 - nitro - 2 - butanol, 2 - or 3 - methyl - 2 - nitrobutanol, 3 - or 4 - methyl - 3 - nitro - 2 - pentanol, 4 - methyl - 2 - nitro - 3 - pentariol, 2 - methyl - 2 - or 4 - nitro - 3 - hexanol, 2- or 3- methyl 3 - nitro- 4 - heptanol, 4 - nitro - 2 - methyl - 3 - heptanol, 2 - nitro - 2 : 4 - dimethyl - 3 - pentanol or 4 - nitro - 2 : 4 - or 2 : 5 - dimethyl - 3 - hexanol, and, on the other hand, acrylic, methacrylic, α - chloroacrylic, itaconic, crotonic or sorbic acid. Specifications 469,976, 494,752 and 547,525 are referred to. Nitroalcohol esters as defined above are obtained by heating the nitroalcohol (a) with the acid in presence of an esterification catalyst, such as p-toluenesulphonic acid or sulphuric acid, and of an anti-oxidants such as hydroquinone, preferably in an inert solvent such as benzene or (b) with a lower alkyl ester of the acid in the presence of an ester-interchange catalyst, such as p-toluenesulphonic acid, and of an anti-oxidant. N-γ-hydroxypropyl - C- cetyl-betaine is obtainable by reaction of α- bromostearic acid with dimethyl-γ-hydroxypropylamine N - - stearyl - betaine is obtainable by reaction of octodecyl bromide with N - dimethyl-glycine. The Specification as open to inspection under Sect. 91 comprises also (a) examples of the production of the ester from 2 - nitro - 2 - methylpropanol and methacrylic acid by boiling a solution of the alcohol in benzene with a strong aqueous solution of the acid for 30 hours in presence of p-toluenesulphonic acid and hydroquinone., and of the ester from 2 - nitro - 2 - methylpropanol and acrylic acid by boiling their solution in toluene in presence of p-toluenesulphonic acid and hydroquinone ; the use of the acid anhydride halide or nitrile in place of the unsaturated acid is also specified ; (b) the polymerization of the unmodified nitro-alcohol esters, an example being given of the polymerization of 2 - nitro - 2 - methylpropyl methacrylate, (c) the interpolymerization of the esters with other polymerizable organic substances in general, such as acrylic, methacrylic, fumaric, maleic, a - chloroacrylic, itaconic, crotonic and atropic acids, their alkyl esters, anhydrides, amides and nitriles, vinyl chloride and styrene, examples being given of the interpolymerization of 2 - nitro - 2 - methylpropyl methacrylate with methyl methacrylate, methyl acrylate, vinyl acetate and vinyl methyl ketone. To obtain a granular product, the polymerization or interpolymerization may be effected in a 0.1 to 1 per cent. aqueous solution of a relatively poor dispersing agent such as an interpolymer of methacrylic acid and methyl methacrylate neutralized to a pH of 7 to 8, sodium cellulose glycollate, sodium starch glycollate, methyl starch, soluble starch, gum tragacanth, gum acacia, polymethacrylamide, partially hydrolysed polyvinyl acetate, partially neutralized polymethacrylic acid, glue, gelatin, agar-agar or sodium alginate. Additional polymerization catalysts specified are inorganic perborates and persulphates in general organic peracids, acetyl benzoyl peroxide, dilauryl peroxide, dibutyryl peroxide and succinyl peroxide. This subjectmatter does not appear in the Specification as accepted.