摘要:
Aromatic nitro compounds in waste waters from nitrobenzene production plants are degraded by treatment with ozone at 60-100° C. 1.5-10 bar and pH 3 to 12.
摘要:
Ruthenium tetroxide is obtained by oxidation of an alkali metal ruthenate in aqueous solution. The oxidizing agent used is ozone. The oxidation is carried out at a pH greater than or equal to 8.
摘要:
Lower polyhydric alcohols are prepared by catalytic hydrogenolysis of sucrose in an aqueous solution by using a catalyst whose active material essentially consists offrom 0 to 100% by weight of cobalt,from 0 to 85% by weight of copper andfrom 0 to 80% by weight of manganese,the percentages being based on the content of the metals.
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.
摘要:
p-Alkoxycyclohexylalkanols and their esters of the general formula I ##STR1## where R.sup.1 is C.sub.1 -C.sub.7 -alkyl, in particular tert.-butyl, or is cyclohexyl, R.sup.2 is C.sub.1 -C.sub.3 -alkyl, in particular methyl or ethyl, and R.sup.3 is hydrogen, acetyl, propionyl or butyryl, and scent compositions containing these compounds I and processes for their preparation. The novel compounds have fine woody or sandalwood notes and can be used as scents and as components of scent compositions.
摘要:
Polyurethane-urea elastomers with improved temperature characteristics, in particular improved low temperature properties, good mechanical properties over a large temperature range and excellent resistance to hydrolysis, are obtained by reacting(A) a prepolymer, possessing cycloaliphatic NCO groups, which has been prepared from essentially difunctional polyhydroxy compounds and organic diisocyanates possessing at least one NCO group bonded to a cycloaliphatic structure, these reactants being used so as to give a ratio of total hydroxyl: NCO groups of from 1:1.2 to 1:10, with(B) 3,3',5,5'-tetramethyl-4,4'-diamino-diphenylmethane, A and B being reacted in the molar ratio of from 1:0.8 to 1:1.2.
摘要:
A process for the selective hydrogenation of aromatic groups of organic molecules carrying at least one aromatic group and one epoxy group with hydrogen in the presence of a ruthenium-containing catalyst, in which a homogeneous ruthenium catalyst is used which can be prepared by reducing the ruthenium compound with a metal having a redox potential of from -0.75 to 2.5 V, a boron hydride, an aluminum hydride, an aluminum alkyl compound, a lithium alkyl compound, or a lithium aryl compound in the presence of an ether.
摘要:
The present invention relates to a process for the preparation of a hard foam containing urethane groups or urethane and isocyanurate groups by the polyisocyanate polyaddition process, by reactinga) a polyoxypropylene- or polyoxyethylene-polyoxypropylene-polyol containing secondary hydroxyl groups, having a functionality of from 3.5 to 4.3, a hydroxyl number of from 350 to 650 and a viscosity of from 500 to 2,500 mPa.multidot.s at 23.degree. C. and prepared by anionic polymerization of 1,2-propylene oxide or ethylene oxide and 1,2-propylene oxide onto an initiator molecule mixture containing, based on the total weight,a1) from 40 to 80% by weight of a hexanetetrol,a2) from 1 to 30% by weight of a hexanetriol,a3) from 0 to 35% by weight of glycerol anda4) from 0 to 15% by weight of sorbitol or mannitol, or a mixture thereof,b) optionally, a low-molecular-weight chain extender and/or crosslinking agent withc) an organic, modified or unmodified polyisocyanate; in the presence ofd) a blowing agent,e) a catalyst and, optionally,f) assistants and/or additives, and novel polyoxypropylene-polyols and polyoxyethylene-polyoxypropylene-polyols which can be used for this purpose.
摘要:
A process for the production of chlorofluorocarbon-free, urethane- or urethane- and urea-containing, soft-elastic, semirigid or rigid moldings having a cellular core and a compacted peripheral zone and an essentially pore-free, smooth surface involves reactinga) an organic and/or modified organic polyisocyanate withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) a low-molecular-weight chain extender and/or cross-linking agent,in the presence ofd) a blowing agent,e) a catalyst,f) at least one microporous activated charcoal and/or microporous carbon molecular sieve which preferably has a mean pore diameter with a frequency of occurrence of more than 40% in the range from 0.3 to 3 nm, a pore volume of from 0.20 to 1.4 ml/g and a BET surface area of from 500 to 2500 m.sup.2 /g, and, if desired, further additives andg) assistants,in a closed mold with compaction.
摘要:
A process for the preparation of lower polyhydric alcohols by catalytic hydrogenation of aqueous saccharose solutions at elevated temperature and pressure using a catalyst of which the catalytically active material essentially contains the metals cobalt, copper and manganese in the following concentrations, the total weight of said metals being standardized as 100%:from 0 to 100% w/w of cobalt,from 0 to 85% w/w of copper andfrom 0 to 80% w/w of manganese,this said metal content of said catalytically active material comprising either cobalt alone or at least two of said metals, which active material may also contain added inorganic poly acids and/or heteropoly acids, wherein from 0.01 to 5% w/w of one or more base-acting metal compounds of metals from the first and second main groups and from group IIIA of the Periodic Table are added to the saccharose solution to be hydrogenated.