摘要:
An improved method for preparing modified organopolysiloxanes which comprises graft polymerizing monomers containing aliphatic unsaturation onto organopolysiloxanes in the presence of a free radical and an inert liquid having a boiling point up to about 100.degree. C. at 760 mm Hg (abs.) and which is a nonsolvent for the organopolysiloxanes and the graft polymers at the applicable polymerization temperatures.
摘要:
The invention relates to a process for the preparation of three-dimensionally crosslinked polymeric materials having a broad cholesteric reflection band, which comprises bringing polymeric materials having cholesteric properties and an extractable material content into contact with a solvent or solvent mixture.
摘要:
Liquid-crystalline polyorganosiloxanes containing methacryloxy and/or acryloxy groups are prepared by reaction of polyorganosiloxanes containing hydrogen atoms bonded directly to silicon atoms with alkenes and/or alkynes containing mesogenic groups in two steps, wherein the polyorganosiloxanes mentioned are reacted in a first step with alkene and/or alkyne containing mesogenic groups and are reacted in a second step with an alkene and/or alkyne containing at least one methacryloxy and/or acryloxy group and mesogenic groups.
摘要:
The liquid-crystalline organosiloxanes containing, per molecule, at least one Si--C-bonded chiral tartarimide radical of the formula ##STR1## in which M, A.sup.5 and k are as defined in claim 1, can be employed as chiral filter materials, for decorative purposes and in optical elements.
摘要:
Hydrophilic, water-dilatable cyclodextrin polymerizates have a high cyclodextrin content and possess good mechanical properties. The cyclodextrin pearl polymerizates are produced by reacting hydroxyalkyl cyclodextrin derivatives with bifunctional crosslinking agents such as epichlorohydrin or diepoxides, followed by hydroxyalkylation of the primary product so obtained. The cyclodextrin polymerizates produced in this manner have mechanical properties appreciably superior to those of known, comparable cyclodextrin polymers.
摘要:
The invention relates to optical elements based on liquid-crystalline substances, and to a process for the production thereof. The optical elements based on liquid-crystalline substances are ones which exhibit no birefringence in a defined direction of incidence, optical elements in which no birefringence occurs perpendicularly to the surface being excepted. The process for preparing the optical elements comprises illuminating a liquid-crystalline substance with unpolarized light of suitable wavelength at a defined angle in such a way that, after illumination, the director of this substance is aligned parallel to the direction of the illuminating light on passing through said substance.
摘要:
The invention relates to dimethylsilyl-substituted benzoyl chlorides and a process for preparing the same, which comprises reacting a dihaloaromatic compound with dimethylchlorosilane and magnesium by the Grignard method to form halophenyldimethylsilanes, then reacting the halophenyldimethylsilanes with magnesium in the presence of carbon dioxide to form the corresponding dimethylsilyl-substituted benzoic acids, and thereafter reacting the dimethylsilyl-substituted benzoic acids with a halogenating agent, such as thionyl chloride, to form dimethylsilyl-substituted benzoyl chlorides.
摘要:
The liquid crystalline organosiloxanes contain per molecule at least one doristeryl group bonded at the 3.beta. position and can be used as right-handed filter materials and optical media.
摘要:
Wavelength-selective and polarization-selective optical elements contain pigments embedded in a transparent binder, in which the pigments include at least one three-dimensionally crosslinked substance having a liquid-crystalline structure with a chiral phase.
摘要:
The present invention relates to cyclic siloxanes which have at least one group of formula (1) bonded to a silicon atom--(CH.sub.2).sub.x --R"--[--L--A--].sub.y --(L).sub.z --T (1),in which x is an integer having a value of at least 2, preferably having a value of from 2 to 10, R" is a chemical bond or a divalent radical of the formula --COO--, --OOC--, --CH.sub.2 --CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C--, --N.dbd.N--, --N.dbd.N, --N.dbd.CH--, --CH.dbd.N or --Si(R).sub.2 --, where the radical R is identical or different and is an optionally substituted hydrocarbon radical having from 1 to 18 carbon atoms, L which is the same or different represents the 1,4-phenylene or 1,4-cyclohexylene radicals which are optionally 2-, 3-, 5- and/or 6-substituted by at least one radical Q, Q is the same or different radical selected from hydrogen, fluorine or chlorine atoms or cyano, methyl or trifluoromethyl groups, A is the same or different and represents divalent radicals R" is a chemical bond or a divalent radical of the formula --CH.sub.2 --O--, --O--CH.sub.2 --, y is an integer having a value of from 0 to 10, preferably from 0 to 2, z is an integer having a value of from 0 to 10, preferably from 0 to 2, with the proviso that the sum y+z is at least 1, and T is a cholesteryl radical or a substituted or unsubstituted hydrocarbon radical having from 1 to 18 carbon atoms, in which the substituents are preferably selected from the group consisting of halogen atoms, cyano groups, nitro groups, hydrocarbonoxy groups having from 1 to 10 carbon atoms and mixtures thereof.