Patent GB-492350-A (GB)
Title: Improvements in the obtention of water-soluble and technically valuable organic derivatives of polymeric metaphosphoric acids
IPC: C07F9/09
Filed: 1937-03-19
Abstract: Polymetaphosphoric acids are prepared by acidifying the known polymetaphosphates, e.g. the tri-, hexa-, octo-, or dodeca-metaphosphates.  Sodium tri- and hexa-metaphosphates may be prepared by heating NaH2PO4 or Na2H2P2O7 to 600 and 700 DEG  C. respectively. Octometaphosphate forms when hexametaphosphate is heated to 550 DEG  C.  Polymetaphosphoric acid mixtures are obtained by heating ortho- or pyro-phosphoric acid.  Mixtures of the acids and their alkali salts are obtained, e.g. by fusing an equimolecular mixture of H3PO4 and NaH2PO4, if desired in presence of sulphuric acid or acetic anhydride.ALSO:Polymethaphosphoric acids or fused mixtures containing them are reacted with organic compounds containing one alcoholic hydroxy group, one or more phenolic hydroxy groups or multiple linkages, e.g. hydroxy or unsaturated fatty acids or their glycerides, such as castor oil or oleic acid, unsaturated hydrocarbons such as octadecylene, higher fatty or naphthenyl alcohols, ethyl, propyl, or benzyl alcohol, phenols, and hydro-phenols.  The acids (HPO3)n where n=3 to 12 have not all been isolated and the use of crude mixtures thereof is included.  They may be obtained by acidifying the known polymetaphosphates, e.g. the tri-, hexa-, octo- or dodeca-metaphosphates.  Sodium tri- and hexa-metaphosphates may be prepared by heating NaH2PO4 or Na2H2P2O7 to 600 and 700 DEG  C. respectively. Octometaphosphate forms when hexametaphosphate is heated to 550 DEG  C.  Polymetaphosphoric acid mixtures are obtained by heating ortho- or pyro-phosphoric acid. Mixtures of the acids and their alkali salts are obtained, e.g. by fusing an equimolecular mixture of H3PO4 and NaH2PO4, if desired in presence of sulphuric acid or acetic anhydride.  The water soluble acid esters of the polymetaphosphoric acids obtained by the process according to the invention may be neutralized, directly or after taking up in water, with alkalis, alkaline - reacting salts, or organic bases.  They react, either before or after neutralizing, with compounds of polyvalent metals such as Ca, Mg, Cr, Fe and Cu to form complexes which contain the metal in non-ionized form.  They can therefore be employed to soften water or bring lime soaps into solution, and for impregnating, preserving, and like purposes in the textile, leather and fur industries.  Thus a solution of the product of example (1) below reacts with chromic salts, and can be used in tanning liquors containing chromium without precipitation thereof, and the product of example (2) will take up Al, Fe or Cu compounds without precipitation.  The acid esters may also be used for introducing alkyl, aryl or other groups, for example by reaction with aromatic hydrocarbons at 60-180 DEG  C.  Thus, n-butyltrimetaphosphoric acid ester with naphthalene at 120-150 DEG C. gives n-butylnaphthalene which in the form of its sulphonic acid is capillary active.  The sulphonic acid is obtained directly by reacting in the presence of sulphuric acid.  In examples: (1) castor oil in kneaded with anhydrous hexametaphosphoric acid.  The reaction product is treated with water, the ester layer separated and neutralized with ammonia or pyridine.  The product is an auxiliary agent in wool dyeing or leather greasing; (2) olein alcohol is similarly reacted and the product neutralized with caustic soda.  It is suitable as a wetting-agent for textile fibres.  Coconut oil alcohols may be used giving a washing agent for human hair; (3) olein and acetic anhydride are added to octometaphosphoric acid and the reaction product neutralized with triethanolamine to give a washing agent; (4) n-butanol is converted with trimetaphosphoric acid to the acid butyl ester which can be used for butylations or reacted with higher alcohols to form the corresponding esters.  Benzyl alcohol, cyclohexanol or cresol can replace butanol.  The Specification as open to inspection under Sect. 91 comprises also the use of organic compounds containing more than one alcoholic hydroxy group. Glycerine, polyglycerines, polyvinyl alcohols, sugar, and starch are specified.  An additional example describes the production of the sodium salt of starch hexametaphosphoric acid ester by mixing potato starch and the acid fusion mixture (NaPO3.HPO3)6.  The product is a size and dressing.  This subject-matter does not appear in the Specification as accepted.ALSO:The Specification as open to inspection under Sect. 91 describes the production of a size and dressing consisting of the sodium salt of starch hexametaphosphoric acid ester by reaction of potato starch and the acid fusion mixture (NaPO3.HPO3)6.  This subject-matter does not appear in the Specification as accepted.