Patent GB-835516-A (GB)
Title: Improvements in or relating to siloxanes
IPC: C08G77/388
Filed: 1958-04-16
Abstract: The invention comprises (i) siloxanes of the unit general formula <FORM:0835516/IV (a)/1> in which R is an aliphatic hydrocarbon radical of less than 4 C atoms, c is 0, 1, 2 or 3, a is 1 or 2, R1 is a di-or tri-valent saturated aliphatic or cycloaliphatic hydrocarbon radical containing at least 2 C atoms, Y is a monovalent hydrocarbon or fluorinated hydrocarbon radical, and m is 0, 1 or 2; (ii) copolymers of from 0.1 to 99.9 mol. per cent of the above units and 0.1 to 99.9 mol. per cent of siloxane units of the formula ZbSiO 4 - b/2 in which Z is a monovalent hydrocarbon or fluorinated hydrocarbon radical and b is 1, 2 or 3; and (iii) compositions comprising from 0.1 to 95% (by weight) of the above siloxane polymer or copolymer and from 5 to 99.9% of an organopolysiloxane having an average of from 1 to 3 substituents selected from H atoms and monovalent hydrocarbon and halogenated hydrocarbon radicals per Si atom.  In the amidomethyl siloxanes, R can be alkyl or alkenyl, R1 can be ethylene, propylene, butylene, octadecylene <FORM:0835516/IV (a)/2> cyclohexylene, cyclopentylene, methylcyclohexylene, <FORM:0835516/IV (a)/3> or <FORM:0835516/IV (a)/4> and Y can be alkyl, alkenyl, cycloaliphatic, alkaryl, aryl or fluorohydrocarbonyl.  The siloxanes (1) are best prepared by reacting a siloxane amide of the formula <FORM:0835516/IV (a)/5> described in Specification 788,984, with the hydrochloride of pyridine or a substituted pyridine and formaldehyde, preferably in the presence, as solvent, of pyridine or a substituted pyridine which corresponds to the hydrochloride reactant.  The siloxanes (1) may be copolymerized with any siloxane, preferably by cohydrohydrolysing a conventional silane with one of the formula <FORM:0835516/IV (a)/6> where R11 is alkyl, heating the resulting copolymer in an autoclave with NH3 to give the corresponding siloxane amide which is subsequently reacted with pyridine hydrochloride and formaldehyde as above.  The siloxanes (1) are useful as fixing agents for conventional siloxane water-repellents.  The copolymers and compositions are useful for rendering textiles water repellent; those copolymers containing at least 30 mol. per cent of aminomethylsiloxane units are water-soluble and can be applied from aqueous solution, whereas other copolymers and compositions are used in organic solvents or aqueous emulsions.  Additional curing agents may be added, e.g. dibutyl tin diacetate, lead 2-ethylhexoate, zinc hexoate, dibutyl tin dilaurate and ethanolamine titanate.  Other resins, e.g. melamine- and urea-formaldehyde resins, and other additives for decreasing slip of the fibres or for imparting soil resistance, e.g. colloidal silica, may also be added.  In typical examples: (1) the siloxane amide <FORM:0835516/IV (a)/7> was dissolved in pyridine, mixed with paraformaldehyde and pyridinehydrochloride and refluxed for 4 hours.  The solvent was then removed by distillation to yield a water-soluble viscous material of the unit formula <FORM:0835516/IV (a)/8> (5) the copolymer amide, obtained by heating the cohydrolysate of <FORM:0835516/IV (a)/9> and <FORM:0835516/IV (a)/100> with anhydrous NH3 in an autoclave, was dissolved in pyridine and refluxed with the reactants as above to give a water-soluble copolymer of <FORM:0835516/IV (a)/111> and <FORM:0835516/IV (a)/122> (16) a composition consisted of an aqueous emulsion of <FORM:0835516/IV (a)/133> a liquid siloxane containing Si-OH groups, a liquid trimethylsilyl end-blocked methylhydrogen siloxane, zinc octoate and dibutyl tin diacetate.  Specifications 769,496 and 788,842 also are referred to.