摘要:
A silacyclohexane compound of the following formula (I) ##STR1## wherein R represents an organic residue; ##STR2## represents a trans-1-sila-1,4-cyclohexylene group or trans-4-sila-1,4-cyclohexylene group having a substituent of H, F, Cl or CH.sub.3 ; L.sub.1 represents F, L.sub.2 and L.sub.3 independently represent H, F, Cl or CH.sub.3 ; X represents an organic residue, F or Cl; and n is an integer of 0, 1, or 2 and a and b are, respectively, 0 or 1 provided that a+b=1. Silacyclohexane compounds are useful in liquid crystal compositions and also in liquid crystal devices.
摘要:
A triflate compound of the following general formula is provided ##STR1## wherein Ar represents a phenyl group or a tolyl group, R represents a phenyl group, a tolyl group, a linear alkyl group having from 1 to 10 carbon atoms, a mono or difluoroalkyl group having from 1 to 10 carbon atoms, a branched alkyl group having from 3 to 8 carbon atoms, an alkoxyalkyl group having from 2 to 7 carbon atoms and an alkenyl group having from 2 to 8 carbon atoms, Tf represents a trifluoromethanesulfonyl group, and Y represents H or F. A process for preparing silacyclohexane-based liquid crystal compounds from the triflate compound is also described.
摘要:
A silacyclohexane carbaldehyde compound of the following formula (I) ##STR1## wherein Ar represents a phenyl group or a tolyl group, and R represents a phenyl group, a tolyl group, a linear alkyl group, a mono or difluoroalkyl group, a branched alkyl group, an alkoxyalkyl group or an alkenyl group. Processes for preparing a silacyclohexane-based liquid crystal compound of the following formula (II) or (III) from the silacyclohexane carbaldehyde are also described ##STR2## wherein X represents CN, F, Cl, CF.sub.3, CClF.sub.2, CHClF, OCF.sub.3, OCClF.sub.2, OCHF.sub.2, OCHClF, (O).sub.m CT=CX.sub.1 X.sub.2, O(CH.sub.2).sub.r (CF.sub.2).sub.s X.sub.3, R or OR wherein m is a value of 0 or 1, T and X.sub.1 independently represent H, F or Cl, X.sub.2 represents F or Cl, r and s are, respectively, a value of 0, 1 or 2 provided that r+s=2, 3 or 4, X.sub.3 represents H, F or Cl, and R has the same meaning as defined before, Y and Z independently represent a halogen or a methyl group, i and j are independently a value of 0, 1 or 2.
摘要:
Processes for selectively preparing silacyclohexane compounds of a trans form from diarylsilacyclohexane compounds of the general formula ##STR1## wherein Ar and Ar' independently represent a phenyl group or a tolyl group, and Q represents a group of the type indicated below ##STR2## The diarylsilacyclohexanes are converted to dihalosilacyclohexanes and then to hydrohalosilacyclohexanes directly or via dialkoxylation and/or reduction step. The hydrohalosilacyclohexane are finally reacted with organometallic compounds having a group, Q', of the type indicated below ##STR3## to obtain silacyclohexane compounds of the general formula ##STR4## wherein Q' and Q have, respectively, the groups indicated hereinabove.
摘要:
A cyclohexane carbaldehyde compound of the following formula (I) ##STR1## wherein Ar represents a phenyl group or a tolyl group, and R represents a phenyl group, a tolyl group, a linear alkyl group, a mono or difiuoroalkyl group, a branched alkyl group or an alkoxyalkyl group. Processes for preparing a silacyclohexane-based liquid crystal compound of the following formula (II) or (III) from the cyclohexane carbaldehyde are also described ##STR2## wherein R represents a phenyl group, a tolyl group, a linear alkyl group, a mono or difiuoroalkyl group, a branched alkyl group or an alkoxyalkyl group, X represents R or OR, in which R has the same meaning as defined above, CN, F, C1, Br, CF.sub.3, OCF.sub.3, OCHFCL, OCF.sub.2 Cl, CF.sub.2 Cl, (O).sub.m CY.sub.1 =CX.sub.1 X.sub.2, O(CH.sub.2).sub.r (CF.sub.2).sub.s X.sub.3, wherein m is a value of 0 or 1, Y.sub.1 and X.sub.1 independently represent H, F or Cl, X.sub.2 represents F or Cl, r and s are, respectively, a value of 0, 1 or 2 provided that r+s=2, 3 or 4, and X.sub.3 represents H, F or Cl, Y represents a halogen or a methyl group, Z represents a halogen or CH.sub.3, i is a value of 0, 1 or 2, and j is a value of 0, 1 or 2.
摘要翻译:下式(I)的环己烷甲醛化合物其中Ar表示苯基或甲苯基,R表示苯基,甲苯基,直链烷基,单或二氟烷基, 支链烷基或烷氧基烷基。 还描述了从环己烷甲醛制备下式(II)或(III)的硅环己烷基液晶化合物的方法,其中苯基,甲苯基,直链烷基,单或二氟烷基,支链 烷基或烷氧基烷基,X表示R或OR,其中R的定义同上,CN,F,C1,Br,CF3,OCF3,OCHFCL,OCF2Cl,CF2Cl,(O)mCY1 = CX1X2,O (CH 2)r(CF 2)s X 3,其中m为0或1,Y1和X1独立地表示H,F或Cl,X2表示F或Cl,r和s分别为0,1或 2,条件是r + s = 2,3或4,X3表示H,F或Cl,Y表示卤素或甲基,Z表示卤素或CH3,i表示0,1或2, j是0,1或2的值。
摘要:
A silacyclohexane compound represented by the following general formula (I). ##STR1## R denotes hydrogen, a linear-chain alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8. For ##STR2## at least one of these is trans-1-silacyclohexylene or trans-4-silacyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3, and the other denotes trans-1,4-cyclohexylene group. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group.
摘要:
A synthetic silica glass article made by hydrolyzing an alkoxysilane and thermally sintering the resulting silica; this synthetic silica glass article has a viscosity of not lower than 10.sup.10 poise at 1400.degree. C., and contains, as metallic impurities, less than 1 ppm of Al, less than 0.2 ppm of Fe, less than 0.2 ppm of Na, less than 0.2 ppm of K, less than 0.01 ppm of Li, less than 0.2 ppm of Ca, less than 0.02 ppm of Ti, less than 0.01 ppm of B, less than 0.01 ppm of P, less than 0.01 ppm of As.
摘要:
The surface-modified polymethylsilsesquioxane spherical fine particles of this invention comprise polymethylsilsesquioxane spherical fine particles serving as nuclei, and at least one member of an alkyl group having two or more carbon atoms, an alkenyl group, a phenyl group, an epoxy group, an acryloxy group and an amino group is bonded to the surface of a particle. They are prepared by a process comprising the step of carrying out reaction in an aqueous suspension of polymethylsilsesquioxane fine particles in the presence of an alkali catalyst. The surface-modified spherical fine particles can have various organic groups on their surfaces, and are used in various fields such as rubbers, plastics, coating materials, inks, and cosmetics, depending on the types of the organic groups.
摘要:
A method for manufacturing synthetic silica glass by reacting methyl silicate and aqueous ammonia, dispersing the silica particles produced in water, solidifying the silica by the addition of methyl silicate and heating, dehydrating, de-solventing, decarburizing and sintering the solid silica to produce a glass product. The sintered glass may be pulverized to produce a powder. The inventive method is easily carried out and avoids the high energy costs of the prior art. The glass product obtained exhibits excellent high temperature viscosity.
摘要:
A process for producing fine spherical silica, comprising a step of hydrolyzing an alkoxysilane in a mixed solution comprising water and alcohol and containing an alkaline catalyst, wherein the amount of said alkaline catalyst is 0.5 to 10 in molar ratio to the alkoxysilane used, the concentration of water in said mixed solution of water and alcohol in 5 to 20 mol/lit., and the reaction temperature for said hydrolysis is 30.degree. C. or more.According to this process, there can be obtained highly monodisperse spherical silica containing only a very small amount of impurities and having a particle size of 100 nm or less.