Polymerizable liquid crystal composition and optically anisotropic medium

1. A polymerizable liquid crystal composition, comprising a liquid crystal compound having a polymerizable group, wherein said composition comprises from 0.1 to 6.0% by weight of a (meth)acrylic copolymer (H), which

1) has a side chain containing a fluorine group, and a side chain containing a group represented by a general formula (h):

(wherein, 6-membered rings A, B, and C each represent, independently:

(and said 6-membered rings A, B, and C may include a fluorine atom or a methyl group), n represents an integer of either 0 or 1, Y 1 , and Y 2 each represent, independently, a single bond, —CH 2 CH 2 —, —CH 2 O—, —OCH 2 —, —COO—, —OCO—, —C≡C—, —CH═CH—, —CF═CF—, —(CH 2 ) 4 —, —CH 2 CH 2 CH 2 O—, —OCH 2 CH 2 CH 2 —, —CH 2 ═CHCH 2 CH 2 —, or —CH 2 CH 2 CH═CH—, and Y 3 represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group, alkoxy group, alkenyl group or alkenyloxy group of 1 to 20 carbon atoms),

2) has a fluorine group content of 3 to 30% by weight,

3) has a ratio of side chains containing said group represented by said general formula (h) relative to a combined total of all side chains that falls within a range from 9 to 95 mol %, and

4) has a weight average molecular weight within a range from 10,000 to 300,000.

2. A polymerizable liquid crystal composition according to claim 1 , wherein said (meth)acrylic copolymer (H) is a (meth)acrylic copolymer produced using, as essential raw materials, a mono(meth)acrylate containing a group represented by said general formula (h), and a mono(meth)acrylate containing a fluoroalkyl group of 1 to 18 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom.

3. A polymerizable liquid crystal composition according to claim 2 , wherein said mono(meth)acrylate containing a group represented by said general formula (h) is a compound represented by a general formula (1) shown below:

(wherein, X represents a hydrogen atom or a methyl group, R represents an alkylene group of 1 to 18 carbon atoms (although within said alkylene group, either one, or two or more methylene groups that are not bonded directly to a —COO— group may be substituted, mutually independently, with an —O— group, provided oxygen atoms are not bonded directly to each other), 6-membered ring A, 6-membered ring B, 6-membered ring C, and groups Y 1 , Y 2 , and Y 3 all represent identical groups to those defined in relation to said general formula (h), and n represents an identical integer to that defined for said general formula (h)).

4. A polymerizable liquid crystal composition according to claim 1 , wherein Y 3 in said general formula (h) is a hydrogen atom.

5. A polymerizable liquid crystal composition according to claim 1 , wherein in said general formula (h), said 6-membered rings A, B, and C are 1,4-phenylene groups or 1,4-cyclohexylene groups.

6. A polymerizable liquid crystal composition according to claim 1 , wherein said general formula (h) is a biphenyl group or a phenylcyclohexyl group.

7. A polymerizable liquid crystal composition according to claim 1 , wherein said (meth)acrylic copolymer (H) comprises from 9 to 95 mol % of structural units represented by a general formula (2), and from 3 to 45 mol % of structural units represented by a general formula (3):

(wherein, R, 6-membered ring A, 6-membered ring B, 6-membered ring C, and groups Y 1 , Y 2 , and Y 3 all represent identical groups to those defined in relation to said general formula (1), n represents an identical integer to that defined for said general formula (1), X 1 and X 2 each represent, independently, a hydrogen atom or a methyl group, and Z represents a fluoroalkyl group of 1 to 18 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom (although methylene groups within said group may be substituted, mutually independently, with a —SO 2 NZ 2 — or —CONZ 2 — group, wherein Z 2 represents an alkyl group, and moreover, said fluoroalkyl group may also include substituent groups)).

8. A polymerizable liquid crystal composition according to claim 1 , wherein said (meth)acrylic copolymer (H) comprises from 9 to 95 mol % of structural units represented by a general formula (2-1), and from 3 to 45 mol % of structural units represented by a general formula (3-1):

(wherein, X represents a hydrogen atom or a methyl group, r represents an integer from 1 to 18, p represents an integer from 1 to 8, q represents an integer from 1 to 13 (provided p+q is at least 2 but no greater than 17), and s represents an integer from 0 to 7).

9. A polymerizable liquid crystal composition according to claim 1 , which exhibits a nematic liquid crystalline phase.

10. A polymerizable liquid crystal composition according to claim 1 , wherein a mixing liquid crystal temperature reduction ΔT defined below is within a range from −10° C. to −0.1° C.:

ΔT=T h −T 0

(wherein, T h =(a liquid-liquid crystal transition temperature when said polymerizable liquid crystal composition comprises 20% by weight of said (meth)acrylic copolymer (H)), and T 0 =(a liquid-liquid crystal transition temperature of a composition in which said (meth)acrylic copolymer (H) is excluded from said polymerizable liquid crystal composition)).

11. An optically anisotropic medium, produced by applying a polymerizable liquid crystal composition according to claim 1 to a substrate that exhibits an alignment function, and then polymerizing said composition in an aligned state.

12. An optically anisotropic medium according to claim 11 , wherein said substrate that exhibits an alignment function is a substrate that exhibits an approximately horizontal alignment function.

13. An optically anisotropic medium according to claim 11 , wherein said substrate that exhibits an alignment function is a substrate with an alignment function in which regions with differing alignment directions are dispersed in a pattern.

14. An optically anisotropic medium according to claim 11 , wherein said substrate that exhibits an alignment function is a substrate containing a photoalignment film.

15. A retardation film, produced by applying a polymerizable liquid crystal composition according to claim 1 to a substrate that exhibits a approximately horizontal alignment function in which regions with differing alignment directions are dispersed in a pattern, and then polymerizing said composition in an aligned state.