Abstract: Reversibly crosslinked, water-soluble cellulose ethers having at least two different ether components is disclosed. At least one ether component is an alkyl, hydroxyalkyl or carboxymethyl group and at least one is an alkyl group having an aldehyde function which forms hydrolyzable hemiacetals with free OH groups of the cellulose ether. The cellulose ethers are obtainable by selective oxidation of cellulose ethers containing alkyl groups having vicinal OH groups (glycol cleavage). Preferably, water-soluble cellulose ethers are co-etherified simultaneously or subsequently with 2,3-epoxypropanol (glycidol) or 3-chloro-1,2-propanediol and the 2,3-dihydroxypropyl ether groups converted entirely or partly into 2-oxoethyl ether groups by oxidation. Suitable oxidants include periodate, periodic acid or lead tetraacetate. After washing and drying, cellulose ethers reversibly crosslinked via hemiacetals can be dispersed in water or aqueous solutions, going into solution homogeneously with a time delay.

Abstract: Reversibly crosslinked, water-soluble cellulose ethers having at least two different ether components is disclosed. At least one ether component is an alkyl, hydroxyalkyl or carboxymethyl group and at least one is an alkyl group having an aldehyde function which forms hydrolyzable hemiacetals with free OH groups of the cellulose ether. The cellulose ethers are obtainable by selective oxidation of cellulose ethers containing alkyl groups having vicinal OH groups (glycol cleavage). Preferably, water-soluble cellulose ethers are co-etherified simultaneously or subsequently with 2,3-epoxypropanol (glycidol) or 3-chloro-1,2-propanediol and the 2,3-dihydroxypropyl ether groups converted entirely or partly into 2-oxoethyl ether groups by oxidation. Suitable oxidants include periodate, periodic acid or lead tetraacetate. After washing and drying, cellulose ethers reversibly crosslinked via hemiacetals can be dispersed in water or aqueous solutions, going into solution homogeneously with a time delay.

Abstract: Use in electrooptical switching and display devices of a polymer comprising conjugatively linked chromophore segments whose emission properties are determined by the emission properties of the individual chromophore segments.Electroluminescence devices comprising the polymers of the present invention have, inter alia, a high color purity. The polymers used according to the present invention enable, in particular, blue and white electroluminescence to also be achieved.

Abstract: Use of spiro compounds of the formula (I) ##STR1## where K.sup.1 and K.sup.2 are, independently of one another, conjugated systems, in electroluminescence devices.Preferred compounds of the formula (I) are 9,9'-spirobifluorene derivatives of the formula (II) ##STR2## where the benzo groups can be substituted independently of one another. Compounds of the formula (I) have a good solubility in customary organic solvents, improved film-forming properties and a significantly reduced tendency to crystallize. The production of electroluminescence devices is thereby made easier and their service life is increased.

Abstract: A process for producing polymers of .alpha.,.omega.-unsaturated conjugated compounds, comprising reacting a precursor monomer of the formula I, ##STR1## wherein P denotes --SR.sup.3, --SO--R.sup.3, --SO.sub.2 --R.sup.3, --COOR.sup.3, --NO.sub.2, --CN, --CF.sub.3 or R.sup.3 ; L denotes --Cl, --Br, --I, --O-tosylate, --O-mesylate, --O-triflate, --(NR.sup.3.sub.3).sym. or --(SR.sup.3 R.sup.4).sym.; R.sup.1,R.sup.2 are the same or different and denote H, R.sup.3 or P; R.sup.3, R.sup.4 and A are as defined in the application. This reaction is characterized in that, on reaction of the base with the compound of the formula (I), a polymer is formed which is essentially soluble in said solvent, and a salt is formed as a by-product, which is essentially soluble in the solvent. That solvent comprises a compound selected from the group consisting of a) amides of the general formula (II) R.sup.5 --CO--NR.sup.6 H; b) amines of the general formula (III) R.sup.7.sub.2 --N--R.sup.8 ; c) sulfones of the general formula (IV) R.

Abstract: Poly(4,5,9,10-tetrahydropyrene-2,7-diyl) derivatives of the formula (I) ##STR1## where the symbols R.sup.1 to R.sup.4 have the following meanings: R.sup.1, R.sup.2, R.sup.3, R.sup.4 are identically or variously H, a straight-chain or branched alkyl chain containing 1 to 22 carbon atoms, it being possible for one or more nonadjacent CH.sub.2 groups also to be replaced by --O--, --COO--, --OOC-- and/or phenylene, aryl or aryloxy groups, it being possible for the aromatic to be substituted by C.sub.1 -C.sub.22 -alkyl, C.sub.1 -C.sub.22 -alkoxy, Br, Cl, F, CN, and/or NO.sub.2, Br, Cl, F, CN, NO.sub.2, or carboalkoxy containing 2 to 23 carbon atoms;n is 10 to 150,are suitable as electroluminescence materials.

Abstract: Conjugated polymers containing ansa substructures and their use as electroluminescence materials.Conjugated polymers containing ansa substructures, which contain aromatic groups and in which adjacent aromatic groups are connected to one another in such a way that one ring atom of one aromatic group is directly linked to one ring atom of the other aromatic group and any further linkages of these two aromatic groups are possible only via a bridge containing at least one tetravalent carbon atom and/or heteroatom.The polymers of the invention having ansa substructures are outstandingly suitable as electroluminescence materials, since they have a very high color purity.

Abstract: Transparent thermoplastic molding composition of a polymer containinga) 10 to 95% by weight of units which are derived from a compound of the formula (I)R.sup.1.sub.2 C.dbd.CF--COO--C(CF.sub.3).sub.2 R.sup.2 (I)b) 90 to 5% by weight of units which are derived from one or more compounds of the formula (II) ##STR1## and c) 0 to 85% by weight of units which are derived from a compound of the formula (III)R.sup.7.sub.2 C.dbd.CF--COO--CR.sup.8.sub.3 (III)The molding composition is used for the production of optical objects, in particular for the production of optical fibers.

Abstract: Transparent thermoplastic molding composition of a polymer containinga) 10 to 95% by weight of units which are derived from a compound of the formula (I)R.sub.2.sup.1 C.dbd.CF--COO--C(CF.sub.3).sub.2 R.sup.2 (I)b) 90 to 5% by weight of units which are derived from one or more compounds of the formula (II) ##STR1## and c) 0 to 85% by weight of units which are derived from a compound of the formula (III)R.sub.2.sup.7 C.dbd.CF--COO--CR.sub.3.sup.8 (III)The molding composition is used for the production of optical objects, in particular for the production of optical fibers.