摘要:
(Cyclo)aliphatic polyisocyanate compositions which have a long shelf life, are obtainable by phosgene-free methods, preferably by thermal cleavage of (cyclo)aliphatic polycarbamates, and, for stabilization, contain at least one primary stabilizer (2a), preferably a sterically hindered phenol and/or an aromatic amine, or at least one secondary stabilizer (2b), preferably an organic phosphite and/or a thioether, or at least one acidic stabilizer (2c), preferably a carboxylic acid, an acyl chloride, an inorganic acid, an inorganic acid chloride and/or a diester of phosphoric acid, or a stabilizer system comprising at least 2 of the stabilizers (2a) to (2c), a process for the preparation of the (cyclo)aliphatic polyisocyanate compositions and their preferred use for the preparation of isocyanurate-containing polyisocyanates.
摘要:
Polyisocyanates containing isocyanurate groups are prepared by a partial trimerization of (cyclo)aliphatic diisocyanates in the presence of at least one trimerization catalyst selected from the group consisting of tetraalkylammonium alkyl carbonates of the formula (I) ##STR1## (quaternary ammonioalkyl) carbonates having a betaine structure of the formula (II) ##STR2## and the preferred use of the polyisocyanates containing isocyanurate groups which are obtainable in this way is aspolyisocyanate component in polyurethane finishes.
摘要:
A process for the preparation of 3-cyano-3,5,5-trimethylcyclohexanone by the reaction of isophorone with hydrogen cyanide in the presence of quaternary ammonium catalysts at temperatures ranging from 80.degree. to 180.degree. C. and pressures ranging from 0.5 to 20 bar, in which the ammonium catalysts used are salts of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 denote C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.18 aralkyl or C.sub.2 -C.sub.18 hydroxyalkyl andX denotes HCO.sub.3 or ##STR2## with the proviso that R.sup.4 stands for C.sub.1 -C.sub.8 alkyl when X is ##STR3##
摘要:
Cyclopentanones of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each an organic radical or R.sup.1 or R.sup.2 may be hydrogen and R.sup.3 is hydrogen or formyl, are prepared by a process in which a 2-formyl-3,4-dihydropyran of the general formula II ##STR2## where R.sup.1 and R.sup.2 have the abovementioned meanings, a) where R.sup.3 is formyl, is converted in the presence of an acidic heterogeneous catalyst at from 50.degree. to 500.degree. C., andb) where R.sup.3 is hydrogen,b.sub.1) is reacted with water or an alcohol in the presence of an acidic heterogeneous catalyst at from 100.degree. to 500.degree. C. in the gas phase orb.sub.2) a compound II or an acrolein of the general formula III ##STR3## is reacted with water or with water in the presence of an acid or with an alcohol in the presence of an acid at from 150.degree. to 400.degree. C. in the liquid phase. Novel 2-formylcyclopentanones are obtained.
摘要:
A process for the preparation of 3-aminomethyl-3,5,5-trimethyl-cyclohexylamine from 3-cyano-3,5,5-trimethyl-cyclohexanone, wherein the following stages are carried out in discrete reaction chambers:a) the 3-cyano-3,5,5-trimethyl-cyclohexanone is reacted in a first reaction chamber with excess ammonia over an acidic metal oxide catalyst at a temperature of from 20.degree. to 150.degree. C. and a pressure of from 15 to 500 bar, andb) in a second reaction chamber, the reaction product from stage a) is hydrogenated with hydrogen at a temperature of from 60.degree. to 150.degree. C. and a pressure of from 50 to 300 bar in the presence of excess ammonia over a catalyst containing cobalt, nickel, ruthenium, and/or some other noble metal, which catalyst optionally contains a basic component or is supported by neutral or basic supporting material.
摘要:
3-Aminopropionitriles of the general formula I ##STR1## where R.sup.1,R.sup.2,R.sup.3,R.sup.4 and R.sup.5 independently of one another are each hydrogen, C.sub.1 -C.sub.20 -alkyl, C.sub.1 -C.sub.8 -aminoalkyl, C.sub.1 -C.sub.8 -cyanoalkyl, C.sub.3 -C.sub.20 -cycloalkyl, C.sub.7 -C.sub.20 -aralkyl or aryl,are prepared by a process in which an amine of the general formula II ##STR2## is reacted with an acrylonitrile of the general formula III ##STR3## where the substituents have the abovementioned meanings, in a molar ratio of from 0.9:1 to 100:1 over a heterogeneous catalyst at from 40.degree. to 200.degree. C. and from 1 to 350 bar.
摘要:
The preparation of 2-substituted but-2-ene-1,4-dial-4-acetals of the formula I ##STR1## in which the substituents R.sup.1 to R.sup.4 stand for hydrogen or C.sub.1 -C.sub.6 aliphatic radicals, and R.sup.2 and R.sup.3 or R.sup.1 and R.sup.2 are in each case common members of an aliphatic 4-membered to 7-membered ring, which can contain a hetero atom, and R.sup.5 denotes an alkyl, alkenyl, or alkynyl radical having from 1 to 12 C atoms, which can be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxy, ether, thioether, acyl, alkylamino, carboxy, or carbalkoxy groups, an optionally substituted aryl radical or an alkoxy, alkylthio, or acyloxy group, whereina) glyoxal is caused to react with a 1,3-propanediol of the formula II ##STR2## in aqueous solution in the presence of an acid to form a monoacetal of the formula III ##STR3## is neutralized, and if necessary the components more readily volatile than the monoacetal III are distilled off,b) the monoacetal III obtained is caused to react with an aldehyde R.sup.5 CH.sub.2 --CHO in the presence of from 0.01 to 10 mol %, based on glyoxal, of a catalyst mixture of a secondary amine and an acid to form an aldol of the formula IV ##STR4## the components which are more volatile than the aldol IV being distilled off if necessary, andc) the aldol IV is dehydrated in the presence of a water-eliminating agent to form the product I,and novel hemiacetals of glyoxal monoacetals.
摘要:
Process for preparing a pentane-1,5-diamine of the formula ##STR1## where R.sup.1 represents a variety of organic radicals including alkyl which can bear substituents such as hydroxyl, halogen, alkoxy, carbalkoxy, carboxyl, alkylamino, cycloalkyl or aryl, andR.sup.2 and R.sup.3 independently of one another, represent hydrogen or have the same meanings as R.sup.1 or together are a C.sub.4 -C.sub.7 -alkylene chain which is unsubstituted or substituted by one to five C.sub.1 -C.sub.4 -alkyl groups,which comprises:(a) reacting a .gamma.-cyanoketone of the formula ##STR2## where R.sup.1, R.sup.2 and R.sup.3 have the meanings given above, with excess ammonia in a first reaction space on an acidic heterogeneous catalyst at 20.degree.-150.degree. C. and 15-500 bar, and(b) hydrogenating the resulting reaction product in a second separate reaction space in the presence of excess ammonia on a cobalt, nickel or noble metal catalyst at 50.degree.-180.degree. C. and 30-500 bar.Novel pentane-1,5-diamines are obtained, in which R.sup.1 must contain at least two carbon atoms if R.sup.2 and R.sup.3 are both hydrogen. These new compounds containing two primary amine groups possess advantageous properties of lower volatility and also greater asymmetry (with different reactivity of the two amine functions). They provide useful curing agents for epoxides and act as improved components of polyamides.
摘要:
A process for the preparation of a 2,2-disubstituted pentane-1,5-diamine of the formula I ##STR1## where R.sup.1 and R.sup.2, independently of one another, are C.sub.1 - to C.sub.10 -alkyl or C.sub.2 - to C.sub.10 -alkenyl or together are a C.sub.4 - to C.sub.7 -alkylene chain which is unsubstituted or monosubstituted to pentasubstituted by C.sub.1 - to C.sub.4 -alkyl, from a 2,2-disubstituted 4-cyanobutanal of the formula II ##STR2## where R.sup.1 and R.sup.2 are as defined above, comprises, in two spatially separate reaction spaces,a) reacting the 4-cyanobutanal of the formula II, in a first reaction space, with excess ammonia on an acidic heterogeneous catalyst at from 20.degree. to 150.degree. C. and at from 15 to 500 bar, andb) hydrogenating the resultant reaction product, in a second reaction space, using excess hydrogen in the presence of excess ammonia on a catalyst containing cobalt, nickel, ruthenium and/or another noble metal, if desired with a basic component or on a basic or neutral carrier, at from 60.degree. to 150.degree. C. and at from 50 to 500 bar.