Liquid crystal composition and liquid crystal display element

A liquid crystal composition, comprising:

• at least one first monomer having a first mesogenic skeleton, at least one polymerizable group represented by the general formula (PG1) linked to the first mesogenic skeleton, and at least one polar group linked to the mesogenic skeleton or the polymerizable group;
• and
• at least one second monomer having a second mesogenic skeleton and a polymerizable group represented by the general formula (PG2) linked to the second mesogenic skeleton, and having a chemical structure different from that of the first monomer, in an amount of more than 0.4% by mass:
• wherein the at least one polar group is represented by general formula (K):
• *—S11—P11 (PG1)
• *—S21—P21 (PG2)
• wherein
• P11 and P21 each independently represent a group represented by any of the following formulae (R-I) to (R-IX):
• wherein
• R21, R31, R41, R51 and R61 each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms;
• W1 is a single bond, —O—, or a methylene group;
• T1 is a single bond or —COO—;
• p1, t1 and q1 are each independently 0, 1, or 2;
• and one or more hydrogen atoms of the polymerizable group P11 may be substituted with the polar group, or the polar group may have a polymerizable group represented by the general formula (PG1) as a substituent;
• S11 and S21 each independently represent a single bond or an alkylene group having 1 to 15 carbon atoms, and one —CH2— or two or more —CH2— that are not adjacent to each other in the alkylene group each may be substituted with the polar group, —O—, —OCO—, or —COO— so long as oxygen atoms are not directly adjacent to each other, and * in the above chemical formulae represents a bonding site:
• *—Sik—Kik (K)
• wherein Sik represents a single bond or an alkylene group having 1 to 15 carbon atoms, and one —CH2— or two or more —CH2— that are not adjacent to each other in the alkylene group may be substituted with —O—, —OCO—, or —COO— so long as oxygen atoms are not directly adjacent to each other, and
• Kik is represented by formulae (K-1), (P-K-3) or (P-K-4):
• wherein in the formulae (K-1)
• WK1 represents a methine group, ≡C—CH3, ≡C—C2H5, ≡C—C3H7, ≡C—C4H9, ≡C—C5H11, ≡C—C6H13, or a nitrogen atom;
• wherein in the formulae (P-K-3) or (P-K-4) Rnk1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and nk1 and nk2 independently represent an integer of 0 to 8;
• wherein one or more hydrogen atoms of Sik or Kik may be substituted with a polymerizable group represented by the general formula (PG1);
• * in the above chemical formulae represents a bonding site.