Patent GB-936978-A (GB)
Title: N-nitroso-hydroxylamine derivatives and a process for the production thereof
IPC: C07F9/06
Filed: 1960-08-10
Abstract: The curing of rubbers in an acidic environment is effected by means of compounds of type <FORM:0936978/IV(a)/1> or of type <FORM:0936978/IV(a)/2> where M is a cation of a base (organic or inorganic) and R is an organic radical (for preparation see Group IV(b)).  In addition to any acidic carbon black or filler present, a free organic or inorganic acid or a latent, acid liberating material which will liberate acid at curing temperature is advantageously present. Latent, acid-liberating materials include molecular sieves having acids absorbed thereon.  The amount of curing agent may be 0,5-4% by weight of the rubber.  Examples describe the curing of polychloroprene using zinc, piperazine and piperidine salts of p-phenylene-N,N1-dinitrosodihydroxylamine, and the sodium salt of 1-oximino-1-(N-nitrosohydroxylamine)-n-butane (the latter also acts as a foaming agent).  Other substances present in one or other of the examples are acidic carbon black, phenyl b -naphthylamine, salicylic acid, mineral oil, stearic acid, a hydrocarbon polymer plasticizer, petrolatum, and liquid soap lubricant.  The curing agents are also said to be effective in curing carboxylic rubbers such as copolymers of acrylonitrile, butadiene and acrylic or methacrylic acid, and rubbers prepared by partial hydrolysis of acrylonitrile-butadiene copolymers.ALSO:Salts of arylene-N,N-dinitrosodihydroxylamines and of 1-oximino-1-N-nitrosohydroxylamines are prepared by reacting a quinone dioxime or an aldoxime, respectively, with at least one equivalent of nitric oxide and at least one equivalent of a base per oxime group in the absence of oxygen.  The invention also comprises compounds of the following formulae:  <FORM:0936978/IV(a)/1> where Aryl is a phenylene, naphthylene, anthrylene or phenanthrylene radical, R is an organic radical, and M is a cation.  Suitable bases for the reaction include alkali metal and ammonium hydroxide, alkali metal alkoxides and organic nitrogenous bases.  Salts of other metals may be obtained from products using such bases by methathesis. Aqueous or organic solutions may be used, as may subatmospheric, atmospheric or superatmospheric pressures.  Reaction temperatures are not generally above 100 DEG C. and may be below 0 DEG C.  The products are useful as curing and foaming agents for rubbers (see Groups IV(a) and V), fuel additives, accelerators, explosives and pesticides.ALSO:Foams may be produced by curing rubbers in an acidic environment by means of a compound of type <FORM:0936978/V/1> where M is a cation of an organic or inorganic base and R is an organic radical (for preparation see Group IV(b)).  In addition to any acidic carbon black or filler, there is advantageously present a free organic or inorganic acid or a substance which will liberate acid at curing temperature, e.g. a molecular sieve having an acid absorbed thereon.  In Example 14, polychloroprene is converted to a closed cell foam by means of the sodium salt of 1-oximino-1-(N-nitrosohydroxylamine)-n-butane.  Also present are stearic and salicylic acids, carbon black, a polymerized hydrocarbon plasticiser, petrolatum, N-phenyl-b -naphthylamine, liquid soap lubricant.