Abstract: A process for the preparation of organophosphorus derivatives of 2,4-di-tert-butylphenol with a high proportion of organophosphorus derivatives of biphenyl, which comprises reacting, in a first step, a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35, under Grignard conditions with magnesium to form the corresponding Grignard compound and this is further reacted in a second step with bis(2,4-di-tert-butylphenyl) chlorophosphite with the formation of a mixture in which at least 50% by weight of the phosphorus is combined in the form of tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphonite. The invention further relates to a polyolefin molding composition containing tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphonite which was prepared by reaction of a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35 with magnesium to form the Grignard compound and by subsequent reaction with bis(2,4-di-tert-butylphenyl) chlorophosphite.

Abstract: The invention relates 6-acyl-(6H)-dibenz[c,e][1,2]oxaphosphorine-6-oxides of the formula ##STR1## wherein each of R.sup.1, R.sup.2 and R.sup.3 may be present one or more times and R.sup.1, R.sup.2 and R.sup.3 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbon atoms and wherein Ar represents an aromatic hydrocarbon group having from 6 to 10 carbon atoms.The invention further relates to a process for the preparation of the afore-mentioned compounds and polymerizable compositions containing them as an essential ingredient as a photo-initiator. Finally the invention relates to 6-alkoxy-(6H)-dibenz[c,e][1,2]oxaphosphorin of the formula II ##STR2## wherein each of R.sup.1 and R.sup.2 may be present once or more times and R.sup.1 and R.sup.2 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbom atoms, at least one R.sup.1 being, however, halogen, and wherein R.sup.

Abstract: The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RSiCL.sub.2 --NR'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.

Abstract: A 3-component lacquer composed of A) compounds containing at least two R.sup.1 R.sup.2 C.dbd.CR.sup.3 --X groups (I) wherein R.sup.1 denotes hydrogen or a hydrocarbon radical having 1 to 10 carbon atoms, R.sup.2 and R.sup.3 are individually hydrogen, a hydrocarbon radical having 1 to 10 carbon atoms, an ester group containing the radical R.sup.4 of a monohydric alcohol having up to 12 carbon atoms, --CN, --NO.sub.2 or a --CO--NHR.sup.1 or --CO--R.sup.1 group, X is --CO-- which is attached to a further R.sup.1 R.sup.2 C.dbd.CR.sup.

Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation, to its processing to form silicon nitride ceramic and to said material itself and its use. The sinterable ceramic powder is prepared by dissolving the polysilazane of formula (I)[CH.sub.3 SiHNH].sub.n [CH.sub.3 SiN].sub.nwhere n is about 10 to 12, in an organic solvent, suspending a pulverulent sinter aid in this solution and then evaporating the solvent and pyrolyzing the residue in an inert gas atmosphere at 500.degree. to 1600.degree. C.The resulting ceramic powder can be used to form a shaped article and then to manufacture silicon nitride ceramic by sintering. It is also possible, however, to form a shaped article from the as yet unpyrolyzed residue obtained after evaporation of the solvent, and then to pyrolyze and sinter said article.The ceramic obtained can be used to manufacture components subject to high mechanical, thermal and corrosive stress.

Abstract: The invention relates to a process for the production of ceramic material containing silicon nitride, such as fibers, coatings or moldings. In this process, polymeric hydridochlorosilazanes are rendered infusible at a temperature below their softening point by treatment with gaseous NH.sub.3 and are then pyrolyzed in an atmosphere containing NH.sub.3 at 700.degree. to 1500.degree. C. Fibers, coatings or moldings containing silicon nitride are produced by first producing appropriate structures from a melt of the polymeric hydridochlorosilazane and then rendering them infusible and pyrolyzing them.

Abstract: The present invention relates to compounds of the general formula I ##STR1## in which R.sup.1, R.sup.1', R.sup.2, A and n are as defined in the description, a process for their preparation, their use and also hydrogels prepared using them.

Abstract: Alkenylphosphonic and -phosphinic acid esters of 1,1,1-tris(hydroxymethyl)alkanes and of 2,2-bis-hydroxymethyl-1,3-propanediol are useful as cross-linking agents in polymeric hydrogels.

Abstract: The invention relates to novel polymeric hydridosilazanes, processes for their preparation and their use for the preparation of ceramic material containing silicon nitride. To prepare the polymeric hydridosilazanes, polymeric hydridochlorosilazanes are reacted with NH.sub.3. To prepare the ceramic material containing silicon nitride, the polymeric hydridosilazanes are then pyrolyzed.

Abstract: The invention relates to rhodium complexes of the formula[A--O--(CH.sub.2 CH.sub.2 O).sub.n --A].sup.2+ 2X.sup.- (Ia)and[A--O--(CH.sub.2 CH.sub.2 O).sub.m --CH.sub.3 ].sup.+ X.sup.-(Ib)in whichn=5-1,000,m=5-250,X.sup.- denotes a tetrafluoroborate, hexafluorophosphate or per-chlorate anion,A denotes a radical of the formula ##STR1## (en).sub.2 denotes two molecules of a monoolefin or one molecule of a diolefinAr denotes phenyl or phenyl which is substituted by one or two alkyl groups having 1 or 2 carbon atoms andR.sup.1 denotes an arylene or alkylene bridge,and their use for the preparation of L-phosphinothricin and its derivatives by enantioselective catalytic hydrogenation of 2,3-dehydrophosphinothricin (derivatives).

Abstract: Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives.

Abstract: The invention relates to novel polysilazanes, their preparation, their further processing to ceramic material containing silicon nitride and this material itself. To prepare the polysilazanes, Si,Si'-diorganyl-N-alkyltetrachloro-disilazanes of the formula RSiCl.sub.2 -NR'-SiCl.sub.2 R are reacted with ammonia. The polysilazanes can then be pyrolyzed to ceramic material containing silicon nitride. The polysilazanes according to the invention dissolve in the customary aprotic solvents.

Abstract: The invention relates to novel polymeric hydridochlorosilazanes and a process for their preparation. The compounds according to the invention can be converted into polyhydridosilaznes by reaction with ammonia, and these can in turn be pyrolyzed to ceramic material containing silicon nitride. To prepare the polymeric hydridochlorosilazanes, oligohydridoalkylsilazanes (R.sup.1 SiHNH).sub.n are reacted with a dichlorohydridoalkylsilane R.sup.2 SiHCl.sub.2.

Abstract: The invention relates 6-acyl-(6H)-dibenz[c,e][1,2]oxaphosphorin-6-oxides of the formula ##STR1## wherein each of R.sup.1, R.sup.2 and R.sup.3 may be present one or more times and R.sup.1, R.sup.2 and R.sup.3 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbon atoms and wherein Ar represents an aromatic hydrocarbon group having from 6 to 10 carbon atoms.The invention further relates to a process for the preparation of the afore-mentioned compounds and polymerizable compositions containing them as an essential ingredient as a photo-initiator. Finally the invention relates to 6-alkoxy-(6H)-dibenz[c,e][1,2]oxaphosphorin of the formula II ##STR2## wherein each of R.sup.1 and R.sup.2 may be present once or more times and R.sup.1 and R.sup.2 represent halogen having an atomic number of from 9 to 35, alkyl or alkoxy each having from 1 to 6 carbon atoms, at least one R.sup.1 being, however, halogen and wherein R.sup.

Abstract: Esters of trihydric or tetrahydric alcohols with alkenylphosphonic or -phosphinic acids, which can be polymerized by means of actinic light, are disclosed. They are combined with polymeric binders, in particular water-soluble polymers, and free-radical-forming photoinitiators to form photopolymerizable mixtures which are suitable for the preparation of photoresists and the production of printing plates. The mixtures show reduced temperature sensitivity and have long shelf lives.

Abstract: A process for the preparation of alkyl esters of alkenylphosphinic acid, having the general formula I ##STR1## wherein R.sup.1 represents H or CH.sub.3, R.sup.2 alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 alkyl having from 1 to 8 carbon atoms, which comprises cleaving an alkyl ester of 2-acetoxyethyl phosphinic acid, having the general formula II ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the meaning indicated above, in contact with a liquid catalytically acting medium and at a partial pressure of the total of the components of the reaction system in the range of from 1 to 500 mbar, and drawing off the resulting alkyl esters of alkenyl phosphinic acid and other volatile reaction products.The invention also relates to compounds of the formula I ##STR3## wherein (a) R.sup.1 represents H, R.sup.2 represents alkyl having from 1 to 4 carbon atoms or phenyl and R.sup.3 represents isobutyl or alkyl having from 5 to 8 carbon atoms, or(b) R.sup.1 represents CH.sub.3, R.sup.

Abstract: Alkenylphosphonic and -phosphinic acid esters of 1,1,1-tris(hydroxymethyl)alkanes and of 2,2-bis-hydroxymethyl-1,3-propanediol are useful as cross-linking agents in polymeric hydrogels.

Abstract: Polymeric hydridothiosilazanes, processes for the preparation thereof, silicon nitride-containing ceramic materials which can be prepared therefrom, and the preparation thereof.The invention relates to novel polymeric hydridothiosilazanes, the preparation thereof, the conversion thereof into silicon nitride-containing ceramic material, and this material itself. To prepare the polymeric hydridothiosilazanes, oligohydridoalkylsilazanes (RSiHNH).sub.n are reacted with elemental sulfur and ether as solvents. The polymeric hydridothiosilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material.

Abstract: A process for the production of .alpha.-aminoalkylphosphonic acids or salts thereof of the formula A ##STR1## wherein R.sup.1 represents hydrogen, alkyl having from 1 to 4 carbon atoms or CH.sub.2 --C.sub.6 H.sub.5 and X hydrogen or a metal cation, which comprises reacting a compound of the formula B ##STR2## in which R.sup.1 has the same meaning as in formula A and Mp.sym. represents hydrogen or a p-valent metal cation, with a hypohalite of a p-valent metal cation, and isolating the metal salt produced or acidifying the reaction mixture obtained to produce the .alpha.-aminoalkyl-phosphonic acid.

Abstract: The invention relates to novel polysilazanes, their preparation, their further processing to ceramic material containing silicon nitride and this material itself. To prepare the polysilazanes, Si,Si'-diorganyl-N-alkyl-tetrachloro-disilazanes of the formula RSiCl.sub.2 -NR'-SiCl.sub.2 R are reacted with ammonia. The polysilazanes can then be pyrolyzed to ceramic material containing silicon nitride. The polysilazanes according to the invention dissolve in the customary aprotic solvents.