Abstract: MDI is prepared by a process comprising the following steps:

Abstract: Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (raw MDI) having a reduced iodine color number and a reduced chlorine content are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, and then, after phosgenation is complete, incorporating into the reaction mixture, in the presence or absence of the phosgene, a mixture of water and at least one monohydric or polyhydric polyoxyalkylene alcohol, preferably having a functionality of from 2 to 3, and advantageously having a hydroxyl number of from 20 to 1800, in an effective amount which advantageously comprises from more than 0.01 to 0.3% by weight of water (i) and from 0.

Abstract: 4,4'-disubstituted bis(2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: 4,4'-disubstituted bis-(2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: Novel carbodiimides and/or oligomeric polycarbodiimides containing terminal isocyanate, urethane and/or urea groups are obtainable, for example, by condensation of 1,3-bis(1-methyl-1-isocyanatoethyl)benzene with elimination of carbon dioxide followed, if desired, by reaction of all or some of the free isocyanate groups of the resultant (poly)carbodiimides with aliphatic, cycloaliphatic or araliphatic amines, alcohols and/or alkoxypolyoxyalkylene alcohols, and are used as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups.

Abstract: 4,4'-disubstituted bis-2,6-diisopropylphenyl)carbodiimides of the formula (I) ##STR1## where R is 1-methyl-1-phenylethyl, phenoxy or tert-butyl, a process for their preparation, their use as stabilizers against hydrolytic degradation of polyaddition and polycondensation products containing ester groups, and the novel 4-(1-methyl-1-phenylethyl)-2,6-diisopropyl-, 4-phenoxy-2,6-diisopropyl- and 4-tert-butyl-2,6-diisopropylphenyl isocyanates which can be used for their preparation.

Abstract: There is now provided a carbodiimide or polycarbodiimide of the formula: ##STR1## where the R radicals are identical or different and are selected from the group consisting of --NHCONHR.sup.1 --, --NHCONR.sup.1 R.sup.2 --, and --NHCOOR.sup.3 --, where R.sup.1 and R.sup.2 may be identical or different and are alkyl, cycloalkyl, or aralkyl, and R.sup.3 is identical to R.sup.1 or is alkoxypolyoxyalkylene, and n is an integer from 0 to 10.There is also provided an ester containing plastic which contains this carbodiimide as an anti-hydrolysis agent. The plastics may be a polyurethane cellular or non-cellular elastomer or thermoplastic.

Abstract: The present invention relates to novel carbodiimides or oligomeric polycarbodiimides containing terminal isocyanate, urea and/or urethane groups, methods for their preparation, and their use as hydrolysis stabilizers.