(DE3933705-C)      Polyurethane foam material is produced by reacting an alcohol (I) having at least two hydroxyl gps., with an isocyanate having at least two isocyanate gps., in the presence of a catalyst, a stabiliser and a blowing agent.    The improvement is that an emulsion is formed with (I), and a halogen-free, organic liq. medium comprising of one or more 3-6C lower alkanes having b.pt., at normal press., (between -10 and 70 deg.C), which does not dissolve (I), with the addn. of other additives e.g. flame protectants and catalysts and other auxiliaries, and opt. with the addn. of an emulsifier. To this emulsion are added the isocyanate components, (conventional for PUR foams in proportions between (I) and the isocyanate components), which are conventional for PUR foams.    Polymerisation of starting materials for the PUR foam to be produced is performed under otherwise conventional conditions, esp. temp. Opt. a slight excess- or deficient press. is maintained during the foam-up process, if the b.pt. of the organic liq. medium requires it.    ADVANTAGE -   No halogen hydrocarbons are used as blowing agents. @(6pp)    (US5182309-A)      The pores of a polyurethane foam are free from halogenated hydrocarbons and contain a minor amount of (a mixt. of) 3-6C alkanes boiling under atmospheric press. at -10 to 70 deg.C, pref. n- or isopentane. The foam contains a catalyst, pore stabiliser and 5-35, pref. 10-20 wt.% solid or liquid flame retardant. The pores pref. also contain N2 in an amount larger than the N2 concentration in air and/or a noble gas, esp. A.    The solid flame retardant is pref. an NH4 salt and the liquid flame retardant is a 1-4C alcohol ester of a 1-4C alkane phosphonate. The foam is produced by (A) mixing an alcoholic starting component of the polyurethane, a flame retardant, catalyst and pore stabiliser, (B) emulsifying the mixt. with the liquid alkane and (C) adding to the emulsion the isocyanate starting components and polymerising the mixt.    ADVANTAGE -   A low density foam is provided having a low heat conductivity, high insulating properties and a high flame retardancy    (DE4003718-C2)      Polyurethane foam has cells free from halohydrocarbons and contg a high percentage of air and a small proportion of 3-6C hydrocarbon added during prepn. as propellant. The foam contains a liq. phosphoric acid ester as flameproofing agent which is added during prepn. in admixture with urea in an amt. of 5-30 wt.% (based on the phosphorus ester) to the emulsified alcoholic component.    ADVANTAGE -   Environmentally unfriendly halohydrocarbons are not present and the fireproofing lasts for many years.    (JP95062090-B2)      The foam (I), contg. catalysts, cell stabilisers, and/or flame retardants, has pores free from halogenated hydrocarbons but contg. minor amts. of blowing agent (II) consisting of at least 3-6C alkane with b.pt. at normal pressure (-)10 - (+)70 deg. C.    Pref. prepn. of (I) using (II), wherein (1) (II), in conventional amt., is finely distributed either (i) in mixt. of alcohol and isocyanate starting components in conventional ratio for (I), and other finely divided additives such as flame retardants, catalysts, and pore stabilisers, or (ii) in alcohol component, with mixing in of additives, then conventional amt. of isocyanate component for forming (I) is incorporated, finely divided, (2) components are polymerised to form (I) under conventional conditions, partic. of temp.    USE/ADVANTAGE -   Conventional uses, (I) are free from ozone layer-damaging halogen-contg. blowing agents, and have low density, low thermal conductivity, and good resistance to burning. @(10pp Dwg.No.0/0)    (RU2058336-C1)      The foam (I), contg. catalysts, cell stabilisers, and/or flame retardants, has pores free from halogenated hydrocarbons but contg. minor amts. of blowing agent (II) consisting of at least 3-6C alkane with b.pt. at normal pressure (-)10 - (+)70 deg. C.    Pref. prepn. of (I) using (II), wherein (1) (II), in conventional amt., is finely distributed either (i) in mixt. of alcohol and isocyanate starting components in conventional ratio for (I), and other finely divided additives such as flame retardants, catalysts, and pore stabilisers, or (ii) in alcohol component, with mixing in of additives, then conventional amt. of isocyanate component for forming (I) is incorporated, finely divided, (2) components are polymerised to form (I) under conventional conditions, partic. of temp.    USE/ADVANTAGE -   Conventional uses, (I) are free from ozone layer-damaging halogen-contg. blowing agents, and have low density, low thermal conductivity, and good resistance to burning.    (EP394769-B1)      The foam (I), contg. catalysts, cell stabilisers, and/or flame retardants, has pores free from halogenated hydrocarbons but contg. minor amts. of blowing agent (II) consisting of at least 3-6C alkane with b.pt. at normal pressure (-)10 - (+)70 deg. C.    Pref. prepn. of (I) using (II), wherein (1) (II), in conventional amt., is finely distributed either (i) in mixt. of alcohol and isocyanate starting components in conventional ratio for (I), and other finely divided additives such as flame retardants, catalysts, and pore stabilisers, or (ii) in alcohol component, with mixing in of additives, then conventional amt. of isocyanate component for forming (I) is incorporated, finely divided, (2) components are polymerised to form (I) under conventional conditions, partic. of temp.    USE/ADVANTAGE -   Conventional uses, (I) are free from ozone layer-damaging halogen-contg. blowing agents, and have low density, low thermal conductivity, and good resistance to burning.