Liquid crystal composition and liquid crystal display device

A liquid crystal composition having positive dielectric anisotropy and including at least one polymerizable compound represented by formula (1) as a first additive, and at least one polar compound represented by formula (5) as a second additive:

• MES-R5 (5)
• in formula (1), ring A and ring C are independently cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in these rings at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkyl having 1 to 12 carbons in which at least one hydrogen has been replaced by fluorine or chlorine;
• ring B is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in these rings at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkyl having 1 to 12 carbons in which at least one hydrogen has been replaced by fluorine or chlorine;
• Z1 and Z2 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene at least one —CH2— may be replaced by —O—, —CO—, —COO— or —OCO—, and at least one —CH2—CH2— may be replaced by —CH═CH—, —C(CH3)═CH—, —CH═C(CH3)— or —C(CH3)═C(CH3)—, and in these groups at least one hydrogen may be replaced by fluorine or chlorine;
• P1, P2 and P3 are a polymerizable group;
• Sp1, Sp2 and Sp3 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene at least one —CH2— may be replaced by —O—, —COO—, —OCO— or —OCOO—, and at least one —CH2—CH2— may be replaced by —CH═CH— or —C═C—, and in these groups at least one hydrogen may be replaced by fluorine or chlorine;
• a is 0, 1 or 2;
• and b and d are 1;
• c is independently 0, 1, 2, 3 or 4, with the proviso that a is 1 or 2 when ring A and ring C are phenyl and that Sp1 and Sp3 are a single bond when a is 1;
• in formula (5), MES is a mesogenic group having at least one ring;
• and R5 is a group represented by any one of formula (A2) to formula (A4):
• in formula (A2) to formula (A4), Sp4, Sp6 and Sp7 are independently a single bond or group (-Sp″-X″—), where Sp″ is alkylene having 1 to 20 carbons, and in the alkylene at least one —CH2— may be replaced by —O—, —S—, —NH—, —N(R0)—, —CO—, —CO—O—, —O—CO, —O—CO—O—, —S—CO—, —CO—S—, —N(R0)—CO—O—, —O—CO—N(R0)—, —N(R0)—CO—N(R0)—, —CH═CH— or —C≡C—, and in these groups at least one hydrogen may be replaced by fluorine, chlorine or —CN, and X″ is —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —CO—N(R0)—, —N(R0)—CO—, —N(R0)—CO—N(R0)—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —CF2CH2—, —CH2CF2—, —CF2CF2—, —CH═N—, —N═CH—, —N═N—, —CH═CR0—, —CY2═CY3—, —C═C—, —CH═CH—CO—O—, —O—CO—CH═CH— or a single bond, where R0 is hydrogen or alkyl having 1 to 12 carbons, and Y2 and Y3 are independently hydrogen, fluorine, chlorine or —CN;
• Sp1 is a trivalent group or a tetravalent group (namely, >CH—, >CR11—, >N—, >C<);
• X3 is —OH, —OR11, —COOH, —NH2, —NHR11, —N(R11)2, —SH, —SR11,
• where R0 is hydrogen or alkyl having 1 to 12 carbons;
• X4 is —O—, —CO—, —NH—, —NR11—, —S— or a single bond;
• R11 is alkyl having 1 to 15 carbons, and in the alkyl at least one —CH2— may be replaced by —C≡C—, —CH═CH—, —COO—, —OCO—, —CO— or —O—, and in these groups at least one hydrogen may be replaced by fluorine or chlorine;
• ring J is an aromatic group having 6 to 25 carbons or an alicyclic group having 3 to 25 carbons, and these groups may be a condensed ring, and in these groups one to three hydrogens may be replaced by RL;
• RL is —OH, —(CH2)i—OH, fluorine, chlorine, —CN, —NO2, —NCO, —NCS, —OCN, —SCN, —C(═O)N(R0)2, —C(═O)R0, —N(R)2, —(CH2)i—N(R)2, —SH, —SR0, aryl having 6 to 20 carbons, heteroaryl having 6 to 20 carbons, alkyl having 1 to 25 carbons, alkoxy having 1 to 25 carbons, alkylcarbonyl having 2 to 25 carbons, alkoxycarbonyl having 2 to 25 carbons, alkylcarbonyloxy having 2 to 25 carbons or alkoxycarbonyloxy having 2 to 25 carbons, and in these groups at least one hydrogen may be replaced by fluorine or chlorine, where R0 is hydrogen or alkyl having 1 to 12 carbons, i is 1, 2, 3 or 4;
• and k is 2, 3, 4 or 5.