摘要:
A homopolymer or copolymer which contains, as a monomer unit, at least one styrene of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 independently of one another denote hydrogen, fluorine or partly or completely fluorinated alkyl or alkoxy andR.sup.4 and R.sup.5 independently of one another represent hydrogen or fluoride, the total number of fluorine atoms in the radicals R.sup.1 to R.sup.5 being at least 3 and the total number of carbon atoms in the radicals R.sup.1 to R.sup.3 being at most 8. The homo- or copolymers can be prepared by vinyl polymerization. They are useful as lenses or other components in an optical system where they have a refractive index n.sub.D of 1.42 to 1.55 with an Abbe number v.sub.D of 30 to 50.
摘要:
In a photopolymerizable composition comprising(a) at least one ethylenically unsaturated photopolymerizable monomer.(b) at least one photoinitiator selected from organic mono- and/or di-carbonyl compounds and(c) a photoactivator, the improvement which comprises employing as said photoactivator at least one alkylaminoarylsulphonyl compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each independently is a hydrogen atom or an alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl group which has 1 to 11 carbon atoms and is optionally substituted by at least one hydroxyl, amino, epoxy, urethane, urea, ether of ether group, or R.sub.1 and R.sub.2 together form a 3- to 6-membered ring, which optionally contains nitrogen, oxygen or sulphur as a hetero-atom,R.sub.3 independently of R.sub.1, has any of the meanings given for R.sub.1 or is a group of the formula ##STR2## R.sub.4 and R.sub.5 each independently is a hydrogen atom, an alkyl or alkenyl group which has 1 to 10 carbon atoms and is optionally substituted by halogen, or a halogen atom, orR.sub.4 and R.sub.5 are in ortho-positions relative to one another and, together with the aromatic nucleus, form a 4- to 8-membered ring, andX is an alkyl or alkenyl group which has 1 to 10 carbon atoms and is optionally substituted by a hydroxyl, amino, urethane, urea or ester group, or is a group of the formula ##STR3## wherein R.sub.6 and R.sub.7, independently of R.sub.1 and R.sub.2, have any of the meanings given above for R.sub.1 and R.sub.2.The compositions are especially useful for dental prostheses, fillings and coatings since they are not irritating to human tissue.
摘要:
The invention relates to novel (meth)-acrylic acid derivatives of tricyclodecanes of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote hydrogen, lower alkyl, lower alkoxy, halogen or trifluoromethyl and R.sup.3 and R.sup.4 are identical or different and represent the groups. ##STR2## in which X is a divalent bridge member comprising the group ##STR3## and Y is a linear or branched hydrocarbon chain which has 2 to 10 carbon atoms and can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals, andR.sup.5 represent hydrogen or methyl andR.sup.6 represents hydrogen, lower alkyl or phenyland to their use in dental compositions.
摘要:
(Meth)-acrylic acid derivatives of tricyclodecanes of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote hydrogen, lower alkyl, lower alkoxy, halogen or trifluoromethyl and R.sup.3 and R.sup.4 are identical or different and represent the group ##STR2## wherein X denotes a divalent bridge member from the group ##STR3## and Y denotes a divalent bridge member from the group ##STR4## and wherein R.sup.5 represents hydrogen or methyl and R.sup.6 represents lower alkyl or phenyl, have been found. Dental compositions in which the present (meth)-acrylic acid derivatives of tricyclodecanes are used, exhibit considerably less polymerization shrinkage.
摘要:
Cationic sizing agents for paper, obtainable by a process in which a water-soluble cationic terpolymer compound, built up in a chemically uniform manner, of (a) 7 to 40% by weight of N,N-dimethylaminoethyl acrylate and/or methacrylate, (b) 40 to 80% by weight of styrene and (c) 4 to 50% by weight of acrylonitrile, the sum of components (a) to (c) always being 100% by weight and at least 10% of the dimethylamino groups of the terpolymer being quaternized with monoepoxides, with the exception of epihalogenohydrins, and the remainder being protonated, is dissolved in an aqueous medium and, in the presence of 10 to 70% by weight--based on the following monomer mixture--of this emulsifier, (d) 5 to 95% by weight of acrylonitrile, meth-acrylonitrile or styrene or mixtures thereof and (e) 5 to 95% by weight of acrylic acid ester and/or methacrylic acid ester with 1 to 12 C atoms in the alcohol radical--the sum of components (d) and (e) always being 100% by weight--are emulsified and the emulsion thus obtained is subjected to emulsion polymerization, initiated by free radicals, at temperatures of 20.degree. to 150.degree. C.
摘要:
The invention relates to a new process for the preparation of cellulose-containing material provided with a dry-strength and wet-strength finish and/or sized, characterised in that the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I), which contains tertiary amino and/or ammonium groups, optionally polyether units and optionally hydrophobic groups.
摘要:
The invention relates to a new process for the preparation of cellulose-containing material provided with a dry-strength and wet-strength finish and/or sized, characterized in that the cellulose-containing material is treated with a water-dispersible polyisocyanate mixture (I), which contains tertiary amino and/or ammonium groups, optionally polyether units and optionally hydrophobic groups.
摘要:
The present invention relates to polymer dyestuffs, i.e. polymer-bound dyestuffs, to a process for their preparation and to their use, for example as markers in analytical procedures. Polymer dyestuffs contain linkable functional groups and are water-soluble under customary conditions of analysis. The polymer portion is usually responsible for this water solubility. The dyestuffs per se are often water-insoluble.
摘要:
An optically active N-(meth)acryloyl amino acid amide of the formula ##STR1## in which R is hydrogen or methyl,R.sub.1 represents an optionally substituted alkyl, cycloalkyl, aralkyl, aryl or heteroaryl radical,R.sub.3 represents hydrogen or denotes together with R.sub.1 a tri- or tetramethylene group;X denotes oxygen or a NR.sub.4 -group wherein R.sub.4 represents hydrogen or alkyl or denotes together with R.sub.2 and the nitrogen atom a 5- to 7-membered ring which ring is optionally substituted by the group COO-alkyl (1-6 carbon atoms) or by one or two alkyl radicals (1-4 carbon atoms) andR.sub.2 denotes a strongly space-filling hydrocarbon radical.The amide is polymerized and optionally bound to a support such as silica, and can then be used for the chromatographic separation of racemic mixtures of pharmacologically active compounds.
摘要:
Process for the preparation of aliphatic polycarbonates by polymerizing cyclic aliphatic carbonates in the presence of initiators and/or catalysts, in which the initiators used are alkoxy silanes of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 independently of one another represent a C.sub.1 -C.sub.4 -alkyl radical, n is an interger from 1 to 6 andR.sub.4 denotes an n-valent, optionally substituted, aliphatic hydrocarbon radical,and the catalysts used are the nucleophilic catalysts which are known from group transfer polymerization.