Patent GB-1039362-A (GB)
Title: Flame-resistant foamed polyurethanes
Inventor: MERTEN RUDOLF
IPC: C08G18/38
Filed: 1965-02-10
Abstract: Polyhydroxyl phosphorus-containing polyols are made by the reaction of carboxylic acids, which may be unsaturated or halogenated, with phosphorous acid and alkylene oxides.  The carboxylic acids are preferably aliphatic or cycloaliphatic and have 8-24 C-atoms and an iodine value not less than 15. Preferably 0.1-10.0 mols. of acid are used per mol. of phosphorous acid.  In general the carboxylic acid is placed in a reaction vessel at 50-150 DEG C. and the phosphorous acid, preferably 60% or stronger aqueous solution, and alkylene oxide are dropped in simultaneously.  However, some alkylene oxide may be held back and added after all the phosphorous acid has been added. The alkylene oxide may also be added to a mixture of the two acids in a reaction vessel.  The reaction may be performed in a solvent, e.g. aromatic or aliphatic compounds, esters, ethers &c., which is subsequently stripped.  Almost any organic compound having a free -COOH group may be used as the carboxylic acid, and commercial mixtures of natural products are quite suitable. The examples describe numerous different products, and methods of preparation. The products should contain 3-25%, preferably 5-20%, of free OH, and at least 1% of phosphorus.ALSO:The invention comprises a process for the production of flame-resistant foam plastics containing urethane groups, derived from the reaction of polyisocyanates, phosphorus-containing polyhydroxyl compounds and blowing agents, in which the phosphorus-containing polyhydroxyl compounds used are the reaction products of carboxylic acids, which may be unsaturated or halogenated, with phosphorous acid and alkylene oxides.  The polyhydroxy compounds are generally prepared by dropping the phosphorous acid and alkylene oxide simultaneously into the carboxylic acid at 50-150 DEG  C., but the reagents may also be mixed in different ways (see also Division C2).  The reaction may be performed in a solvent which is then stripped.  In a preferred embodiment, the carboxylic acid is aliphatic or cycloaliphatic and has 8 to 24 C atoms, an iodine value of at least 15, and between 0.1-10.0 mols. are used per mole of phosphorous acid.  The phosphorous acid used is preferably aqueous, of at least 60% concentration, and in this case it is preferred that at least two mols. of alkylene oxide are used per mol. of phosphorous acid, per mol. of water and per mole of carboxylic acid.  The polyhydroxy compounds obtained in this way should have an OH content of 3-25%, particularly 5-20%, and a phosphorus content of at least 1%.  When unsaturated acids have been used in their preparation, halogenation may optionally be performed (using Cl2 or Br2) on the products.  The polyisocyanates employable include aromatic and aliphatic polyisocyanates which may additionally contain groups such as alkoxy, NO2 or Cl, and modified polyisocyanates containing sub-equivalent quantities of polyhydroxy compounds.  Also to be used include polyisocyanates, masked for example with phenols or bisulphite.  At least an equivalent amount of isocyanate should be used in the reaction, with respect to the amount of active hydrogen present in the polyol.  If water is used as the blowing agent, a corresponding excess of isocyanate must be used.  Other blowing agents include azo-compounds, and low-boiling organic liquids.  It is preferable to foam in the presence of a catalyst, e.g. a tertiary amine or organic tin compound.  Further additives include emulsifiers, foam-stabilizers, dyestuffs, pigments and flame-retardants.