Verfahren zur Herstellung neuer Polyaether und von davon abgeleiteten Polyurethanschaeumen

摘要

A polyether composition is prepared by the reaction of sucrose, glycerol and propylene oxide in the relative amounts by weight of 552-210, 100 and 1900-570 respectively in the presence of an alkali metal hydroxide as catalyst at 50-150 DEG C. to give a polyether containing 2.0-1.2 molecules of propylene oxide per hydroxyl group of sucrose and glycerol. The preferred polyether contains 1.7-1.3 molecules propylene oxide per hydroxyl group and is made from 375-270 parts sucrose, 100 parts glycerol and 1000-600 parts propylene oxide. The preferred temperature range is 60-95 DEG C. and the reaction time varies, according to temperature employed, from about 4 to about 40 hours. The reaction may be effected at atmospheric or superatmospheric pressures. Potassium hydroxide is the preferred catalyst and may be used in amounts of, e.g. 1/2 -5 parts, measured as potassium, per 100 parts glycerol. The presence of more than 1% by weight of water based on weight of reactants has a detrimental effect on the product and it is desirable to keep the water content below 0.25%. The reaction may be carried out in, e.g. a kettle or vertical column reactor generally by mixing the catalyst and glycerol, gradually adding sucrose and reacting the mixture with propylene oxide. The polyether compositions are used to make polyurethane foams (see Division C3). Examples describe the preparation of polyethers characterized by their hydroxyl numbers and viscosity. Specification 935,424 is referred to.ALSO:Polyurethane foams are prepared from aromatic polyisocyanates and polyethers obtained by the reaction of 100 parts by weight of glycerol with 550-210 parts sucrose and 1900-570 parts propylene oxide in the presence of an alkali metal hydroxide as catalyst at 50-150 DEG C., the resulting polyether containing an average of 2.0-1.2 molecules of propylene oxide per hydroxyl group of sucrose and glycerol. Toluene diisocyanate is the preferred isocyanate; other aromatic diisocyanates are specified. The foams are prepared by conventional methods. The preferred blowing agents are water and halogenated aliphatic hydrocarbons. Suitable catalysts are (a) tertiary amines, e.g. triethyl amine, (b) tertiary amines containing OH groups and capable of cross-linking the polyurethane, i.e. those of the general formula where X1-4 are the same or different and represent H-(O-alkylene)z, where z is 1-4 and alkylene is a divalent aliphatic saturated hydrocarbon radical having 1-10 C's and also one of X1-4 can be a 1-20 C alkyl group, n is 1-10, preferably 2 or 3, m is 0 or 1-3 and y is 1-10, e.g. tetra(hydroxyethyl) ethylene diamine, (c) an organo tin compound of the general formula where X is a 1-18 C alkyl group, R1-3 are 1-18 C alkyl groups, H, halogen or a hydrocarbon acyl group, R1-3 being the same or different and two of R1-3 may be together oxygen or sulphur, e.g. tetramethyltin, tetra-octyltin, dimethyldioctyltin, triethyltin-chloride, dioctyltindichloride, dilauryltindifluoride, 2 - ethylhexyltintriiodide, di-n-octyltin oxide, di-n-butyltindilaurate, di-n-butyltindiacetate, di-n-octyltin bis(monobutylmaleate, di - 2 - ethylhexyltin bis(2 - ethylhexanoate), tri - n - butyltin acetonate and dibutyltin diacetate, and (d) organic tin salts, e.g. stannous octoate, stannous oleate. The catalysts may be single compounds or one or more of above types or mixtures of types. Dispersing agents which can be used include polyethylene oxide, phenyl ethers, blends of polyalcohol carboxylic esters, oil-soluble sulphonates and siloxane-oxyyalkylene block copolymers. The foams may also contain cross-linking agents, auxiliary blowing agents and pigments. Examples (1)-(3) describe the preparation of a foam using toluene diisocyanate in the one-shot technique using tetrakis (hydroxypropyl)ethylene diamine as a cross-linking agent, a silicone oil as an emulsifying agent, dibutyl tin laurate and dimethylethanolamine as catalysts and trichlorofluoroethane as the blowing agent. Example (4) describes the preparation of a foam using the pre-polymer technique. Specification 935,424 is referred to.