Liquid crystal medium

Abstract

The present invention relates to a liquid crystal (LC) medium comprising a terphenyl compound and at least two polymerisable compounds, to a process for its preparation, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in an LC display of the polymer sustained alignment (PSA) type, and to an LC display, especially a PSA display, comprising it.

1 - 17 . (canceled) 
     
     
         18 . A liquid crystal (LC) medium comprising
 one or more polymerisable compounds having two polymerisable groups at a concentration of 0.1 to 0.5% by weight, and   one or more polymerisable compounds having three polymerisable groups at a concentration of 0.01 to 0.15% by weight, which are selected from the following trireactive polymerisable compounds   
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           in which
 Sp 1 , Sp 2 , Sp 3  each, independently of one another, denotes a spacer group or a single bond, 
 P 1 , P 2 , P 3  each, independently of one another, denotes a polymerisable group, 
 L each, independently of one another, denotes F, Cl, —CN, —NO 2 , —NCO, —NCS, —OCN, —SCN, —C(═O)N(R x ) 2 , —C(═O)Y 1 , —C(═O)R x , —N(R x ) 2 , optionally substituted silyl, optionally substituted aryl or heteroaryl having 5 to 20 ring atoms, or straight-chain or branched alkyl having 1 to 25, in which one or more non-adjacent CH 2  groups are optionally each replaced, independently of one another, by —C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, —CN, 
 R x  each, independently of one another, denotes H, F, Cl, CN, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P— or P-Sp-, 
 R 0 , R 00  each, independently of one another, denotes H or alkyl having 1 to 20 C atoms, 
 Y 1  each, independently of one another, denotes halogen, 
 r each, independently of one another, denotes 0, 1, 2, 3 or 4, and 
 t each, independently of one another, denotes 0, 1 or 2, 
 X 1 , X 2 , X 3  is —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —NR 0 —CO—NR 00 — or a single bond, 
 
         
         and 
         one or more compounds of the following formulae 
       
       
         
           
           
               
               
           
         
         
           wherein 
           a denotes 1 or 2, 
           b denotes 0 or 1, 
         
       
       
         
           
           
               
               
           
         
       
       denotes 
       
         
           
           
               
               
           
         
         
           R 1  and R 2  each, independently of one another, denotes alkyl having 1 to 12 C atoms, in which one or two non-adjacent CH 2  groups are optionally replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another, 
           Z x  and Z y  each, independently of one another, denotes —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 F 4 —, —CF═CF—, —CH═CH—CH 2 O— or a single bond, 
           L 1-4  each, independently of one another, denotes F, Cl, OCF 3 , CF 3 , CH 3 , CH 2 F, or CHF 2 , 
         
         wherein the concentration of the compounds having two polymerisable groups is higher than the concentration of the compounds having three polymerisable groups, and 
         wherein the LC medium does not contain any unpolymerisable compounds having a terphenyl group. 
       
     
     
         19 . The LC medium of  claim 18 , comprising one or more of the following compounds 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in which a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denotes a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and “(O)” denotes an O-atom or a single bond. 
       
     
     
         20 . The LC medium of  claim 18 , comprising one or more of the following compounds 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in which alkyl and alkyl* each, independently of one another, denotes a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and “(O)” denotes an O-atom or a single bond. 
       
     
     
         21 . The LC medium of  claim 18 , comprising, as the one or more polymerisable compounds having two polymerisable groups, one or more of the following direactive polymerisable compounds 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in which 
         Sp 1 , Sp 2  each, independently of one another, denotes a spacer group or a single bond, 
         P 1 , P 2  each, independently of one another, denotes a polymerisable group, 
         L each, independently of one another, denotes F, Cl, —CN, —NO 2 , —NCO, —NCS, —OCN, —SCN, —C(═O)N(R x ) 2 , —C(═O)Y 1 , —C(═O)R x , —N(R x ) 2 , optionally substituted silyl, optionally substituted aryl or heteroaryl having 5 to 20 ring atoms, or straight-chain or branched alkyl having 1 to 25, in which one or more non-adjacent CH 2  groups are each optionally replaced, independently of one another, by —C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, —CN, 
         Z 1-3  each, independently of one another, denotes —O—, —CO—, —CO—O—, —O—CO—, —C(R y R z )—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 CH 2 — or —CF 2 CF 2 —, 
         R x  each, independently of one another, denotes H, F, Cl, CN, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P— or P-Sp-, 
         R y , R z  each, independently of one another, denotes H, F, CH 3  or CF 3 , 
         R 0 , R 00  each, independently of one another, denotes H or alkyl having 1 to 20 C atoms, 
         Y 1  each, independently of one another, denotes halogen, 
         r each, independently of one another, denotes 0, 1, 2, 3 or 4, 
         s each, independently of one another, denotes 0, 1, 2 or 3, and 
         t each, independently of one another, denotes 0, 1 or 2. 
       
     
     
         22 . The LC medium of  claim 18 , comprising, as the one or more polymerisable compounds having three polymerisable groups, one or more of the following trireactive polymerisable compounds 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         23 . The LC medium of  claim 18 , further comprising one or more of the following compounds 
       
         
           
           
               
               
           
         
         in which 
       
       
         
           
           
               
               
           
         
       
       each, independently of one another, denotes 
       
         
           
           
               
               
           
         
       
       each, independently of one another, denotes 
       
         
           
           
               
               
           
         
       
       each, independently of one another, denotes 
       
         
           
           
               
               
           
         
         R A1  each, independently of one another, denotes alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, also one of the meanings of R A2 , 
         R A2  each, independently of one another, denotes alkyl having 1 to 12 C atoms, in which one or two non-adjacent CH 2  groups are optionally replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another, 
         Z x  each, independently of one another, denotes —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 F 4 —, —CF═CF—, —CH═CH—CH 2 O—, or a single bond, 
         L 1,2  each, independently of one another, denotes H, F, Cl, OCF 3 , CF 3 , CH 3 , CH 2 F or CHF 2 H, 
         x each, independently of one another, denotes 1 or 2, and 
         z each, independently of one another, denotes 0 or 1. 
       
     
     
         24 . The LC medium of  claim 18 , further comprising one or more of the following compounds 
       
         
           
           
               
               
           
         
         in which m denotes 1, 2, 3, 4, 5 or 6, i denotes 0, 1, 2 or 3, and R b1  denotes H, CH 3  or C 2 H 5 . 
       
     
     
         25 . The LC medium of  claim 18 , further comprising one or more of the following compounds 
       
         
           
           
               
               
           
         
         in which m and n each, independently of one another, denote 1, 2, 3, 4, 5 or 6, and alkenyl denotes CH 2 ═CH—, CH 2 ═CHCH 2 CH 2 —, CH 3 —CH═CH—, CH 3 —CH 2 —CH═CH—, CH 3 —(CH 2 ) 2 —CH═CH—, CH 3 —(CH 2 ) 3 —CH═CH— or CH 3 —CH═CH—(CH 2 ) 2 —. 
       
     
     
         26 . The LC medium of  claim 18 , comprising a polymerisable component A) comprising one or more polymerisable compounds, and a liquid-crystalline component B) comprising one or more mesogenic or liquid-crystalline compounds, wherein
 the polymerisable component A) comprises   one or more polymerisable compounds having two or more polymerisable groups at a concentration 52% by weight, and   one or more polymerisable compounds having three polymerisable groups at a concentration ≤1% by weight, and   the liquid-crystalline component B) comprises one or more compounds of formula CY or PY, and   the LC medium does not contain any unpolymerisable compounds having a terphenyl group.   
     
     
         27 . The LC medium of  claim 18 , wherein the polymerisable compounds are polymerised. 
     
     
         28 . A LC display comprising an LC medium as defined in  claim 18 , which is preferably a PSA type display, and even more preferably a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA or PS-TN display. 
     
     
         29 . A LC display comprising two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the substrates a layer of an LC medium as defined in  claim 18  wherein the polymerisable compounds are polymerised between the substrates of the display. 
     
     
         30 . A process for the production of an LC display comprising two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the substrates a layer of an LC medium as defined in  claim 18  wherein the polymerisable compounds are polymerised between the substrates of the display, said process comprising the steps of providing said LC medium between the substrates of the display, and polymerising the polymerisable compounds. 
     
     
         31 . A process of preparing an LC medium according to  claim 18 , comprising the steps of mixing one or more compounds of formula CY and/or PY with one or more of said polymerisable compounds and optionally with further LC compounds and/or additives. 
     
     
         32 . The LC medium of  claim 18 , wherein
 R 1  and R 2  each, independently of one another, denotes alkyl or alkoxy having 1 to 6 C atoms, and/or   Z x  and Z y  each denotes a single bond.   
     
     
         33 . The LC medium of  claim 18 , comprising one or more compounds of each of formulae CY and PY. 
     
     
         34 . The LC medium of  claim 18 , in which the only polymerizable compounds are the one or more polymerisable compounds having two polymerisable groups at a concentration of 0.1 to 0.5% by weight, and
 the one or more polymerisable compounds having three polymerisable groups at a concentration of 0.01 to 0.15% by weight.   
     
     
         35 . The LC medium of  claim 18 , wherein the one or more polymerisable compounds having three polymerisable groups are of one or more of formulae II1, II2, II3, II4, II5, II6, II9, II10, II11, II12, II13, and/or II14. 
     
     
         36 . The LC medium of  claim 18 , wherein the one or more polymerisable compounds having three polymerisable groups are of one or more of formulae II3, II4, II5, II6, II13, and/or II14. 
     
     
         37 . The LC medium of  claim 18 , wherein at least one of the groups Sp 1 , Sp 2 , Sp 3  is not a single bond. 
     
     
         38 . The LC medium of  claim 18 , which contains trireactive compounds selected from the group consisting of compounds of formulae II1, II2, II3, II4 and II5. 
     
     
         39 . A liquid crystal (LC) medium comprising
 one or more polymerisable compounds having two polymerisable groups at a concentration of 0.2 to 0.5% by weight, and   one or more polymerisable compounds having three polymerisable groups at a concentration of 0.01 to 0.15% by weight, which are selected from the following trireactive polymerisable compounds   
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           in which 
           Sp 1 , Sp 2 , Sp 3  each, independently of one another, denotes a spacer group or a single bond, 
           P 1 , P 2 , P 3  each, independently of one another, denotes a polymerisable group, 
           L each, independently of one another, denotes F, Cl, —CN, —NO 2 , —NCO, —NCS, —OCN, —SCN, —C(═O)N(R x ) 2 , —C(═O)Y 1 , —C(═O)R x , —N(R x ) 2 , optionally substituted silyl, optionally substituted aryl or heteroaryl having 5 to 20 ring atoms, or straight-chain or branched alkyl having 1 to 25, in which one or more non-adjacent CH 2  groups are optionally each replaced, independently of one another, by —C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—U—, —O—CO—, or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, —CN, 
           R x  each, independently of one another, denotes H, F, Cl, CN, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P— or P-Sp-, 
           R 0 , R 00  each, independently of one another, denotes H or alkyl having 1 to 20 C atoms, 
           Y 1  each, independently of one another, denotes halogen, 
           r each, independently of one another, denotes 0, 1, 2, 3 or 4, and 
           t each, independently of one another, denotes 0, 1 or 2, 
           X 1 , X 2 , X 3  is —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR 0 —, —NR 0 —CO—, —NR 0 —CO—NR 00 — or a single bond, 
         
         and 
         one or more compounds of the following formulae 
       
       
         
           
           
               
               
           
         
         
           wherein 
           a denotes 1 or 2, 
           b denotes 0 or 1, 
         
       
       
         
           
           
               
               
           
         
       
       denotes 
       
         
           
           
               
               
           
         
         
           R 1  and R 2  each, independently of one another, denotes alkyl having 1 to 12 C atoms, in which one or two non-adjacent CH 2  groups are optionally replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another, 
           Z x  and Z y  each, independently of one another, denotes —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 F 4 —, —CF═CF—, —CH═CH—CH 2 O— or a single bond, 
           L 1-4  each, independently of one another, denotes F, Cl, OCF 3 , CF 3 , CH 3 , CH 2 F, or CHF 2 , 
         
         wherein the LC medium does not contain any unpolymerisable compounds having a terphenyl group.