Triphenylene compounds and preparation of discotic liquid crysta

Details Triphenylene compounds and preparation of discotic liquid crysta Triphenylene compounds and preparation of discotic liquid crysta

1996-05-22

1998-04-07

Kelly, Cynthia Harris

Compositions

Liquid crystal compositions

Containing nonsteryl liquid crystalline compound of...

25229901, 25229961, 2522996, 252582, C09K 1932, C09K 1952, C09K 1934, F21V 900

Patent

active

057360685

DESCRIPTION:

BRIEF SUMMARY
This application is a 371 of PCT/EP 94/03649 filed Nov. 8, 1994.
The present invention relates to novel triphenylene compounds, processes for the preparation of discotic liquid crystalline crosslinked polymers using these novel triphenylene compounds and the use of the crosslinked polymers as charge transport materials, for example in photocopiers or in laser printers.
Photoconductor coatings based on inorganic substances, for example on selenium, tellurium or cadmium, and those based on organic polymers are already known. Thus, the production of drum coatings of organic polymers by photochemical methods is described, for example, in EP-A-0 504 059.
Organic photoconductors (OPC) are mainly used as photosensitive materials in electrophotography and the printing industry.
Aspects of the interaction of light with discotic liquid crystalline systems are described in the publication by A. M. Fox et al. in C & EN 71 (1993), 38-48.
Van der Pol et al. (Macromolecules 23 (1990) 155) describe the synthesis and properties of discotic liquid crystalline metallophthalocyanines having the functionality of eight. It is true that thermal crosslinking gives insoluble liquid crystalline materials which have increased electrical conductivity, particularly after doping with iodine. However, utilization of the photoconductivity is technically impossible here since it is superposed by the high intrinsic conductivity.
The photoconductive properties of low molecular weight liquid crystals in the discotic phase or one of the kalamitic liquid crystalline phases (cf. for example EP-A 254 060) are also known. In the case of these, however, the mechanical stability in the liquid crystalline phase is not guaranteed. Furthermore, polymeric discotic liquid crystalline phases, possibly doped with trinitrofluorenone, are known and are proposed for use as photoconductors (cf. U.S. Pat. No. 4,865,762). However, such polymeric systems have serious disadvantages in the orientation, since it is not possible to achieve defect-free orientation of the columns in the discotic liquid crystalline phase.
In some of the coating processes currently employed, toxic substances are used and in some large amounts of organic solvents are released, which make it more difficult to comply with special regulations on reduction of emissions. Moreover, the organic photoconductors used at present have very low charge carrier mobilities.
Discotic liquid crystalline triphenylenes have excellent photoconductivity in the liquid crystalline phase, which is due to the molecular orientation of the substance. However, this technical advantage cannot be used in the conventional OPC technology since the liquid crystalline properties are lost.
It is an object of the present invention to provide novel polyfunctional compounds which are suitable for the preparation of discotic liquid crystalline crosslinked polymers, the prior art disadvantages described above being avoided.
We have found that this object is achieved and that, surprisingly, the applied layer can be crosslinked and cured by direct application of a polymerizable mixture of triphenylene compounds polysubstituted by polymerizable functions and subsequent thermal and/or photochemical polymerization. Particularly owing to the mild photochemical polymerization procedure, the special arrangement for increased conductivity is not destroyed.
The present invention relates to compounds of the general formula (I) ##STR1## where R.sup.1 to R.sup.12 are identical or different and are each hydrogen, halogen, alkyl, X-alkyl, where X is O, S or NH, or N(alkyl).sub.2, where each alkyl radical is 1 to 20 carbon atoms, or are each such additionally substituted alkyl radicals or are each radicals which contain C--C double bonds, C--C triple bonds, oxiranyl groups or thiiranyl groups, with the proviso that at least three of the radicals R.sup.1 to R.sup.12 are radicals containing C--C double bonds, C--C triple bonds or oxiranyl or thiiranyl groups.
Particularly suitable radicals containing C--C double bonds are those of the general f

REFERENCES:
patent: 4333709 (1982-06-01), Dubois et al.
patent: 4430650 (1984-02-01), Billard
patent: 4631143 (1986-12-01), Praefcke et al.
patent: 4865762 (1989-09-01), Kreuder et al.
patent: 4980081 (1990-12-01), Ringsdorf et al.
patent: 5308535 (1994-05-01), Scheuble et al.
Bechgaard et al., J. Am. Chem. Soc., vol. 94, pp.
Piatelli et al., Tetrahedron, 1965, vol. 21, pp. 3229-3236.
Matheson et al., Chem. Comm., no. 13, 1965, pp. 278-279.
van der Pol et al., Macromolecules, 1990, vol. 23, pp. 155-162.
Fox et al., C&EN, vol. 71, pp.38-48, 1993.
Kurihara et al., Mol. Crystl. Ordered Fluids, vol. 4, pp. 57-74, 1984.
LeBarny et al., Liq. Crystl. Ordered Fluids, vol. 4, pp. 57-74, 1984.
Chapuzet et al., Tetrahedron, vol. 47, no. 4/5, pp. 791-798, 1991.
Collard et al., J. of Amer. Chem. Society, vol. 113, no. 23, Nov. 6 1991.
Shenouda et al., Polym. Prepr.(Am. Chem. Soc., Div. Polym. Chem.), vol. 33, no. 1, pp. 1048-9, 1992.

Affiliated with

Also associated with

Rating

Triphenylene compounds and preparation of discotic liquid crysta does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Triphenylene compounds and preparation of discotic liquid crysta, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Triphenylene compounds and preparation of discotic liquid crysta will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-9880