Liquid crystal optical element and process for its production

A liquid crystal optical element, comprising:

• a pair of substrates with electrodes, of which at least one is transparent;
• and
• an electrooptical functional layer containing a liquid crystal and a polymer sandwiched between the substrates, and which is configured to exhibit a light beam transmitting state and a light beam scattering state by changing an alignment state of the liquid crystal in response to application of a voltage, wherein
• the polymer forms a plurality of assemblies of column resins;
• each of the assemblies of the column resins is formed so that it has an axial core which substantially agrees with a normal direction of a plane of the substrates with electrodes, and an area occupied by the column resins in the electrooptical functional layer on the horizontal plane to the plane of the substrates with electrodes substantially decreases as the distance from the substrates with electrodes increases;
• and
• the assemblies of the column resins are connected to one another to form a domain region of the liquid crystal.

A process for producing a liquid crystal optical element comprising a pair of substrates with electrodes, a pair of alignment films and an electrooptical functional layer containing a liquid crystal and a polymer sandwiched between the substrates and disposed to be in contact with the pair of alignment films, the process comprising:

• forming a liquid crystalline mixture (D) containing at least one type of a bifunctional polymerizable compound (A) represented by the formula (1), at least one type of a bifunctional polymerizable compound (B) represented by the formula (2) and a non-polymerizable liquid crystalline composition (C);
• disposing the mixture (D) between a pair of alignment films;
• and
• polymerizing the polymerizable compounds in the mixture (D) in a state where the mixture (D) shows liquid crystallinity, to form a polymer:
• A1-R1-X1-(Q3-Z2)p-Q1-Z1-Q2(Z3-Q4)q-X2-R2-A2 (1)
• A3-R3-A4 (2)
• wherein each of A1, A2, A3 and A4 which are independent of one another, is an acryloyloxy group, a methacryloyloxy group, a vinyl ether group, a vinyl group or a glycidyl ether group;
• each of Q1, Q2, Q3 and Q4 which are independent of one another, is a 1,4-phenylene group which may have a substituent, a 1,4-cyclohexylene group or a pyrimidine-2,5-diyl group;
• each of X1 and X2 which are independent of each other, is a single bond, an oxygen atom or an ester linkage;
• each of R1 and R2 which are independent of each other, is a single bond or a linear or branched C1-20 alkylene group which may have one or more ethereal oxygen atoms between carbon atoms;
• each of Z1, Z2 and Z3 which are independent of one another, is a single bond, C(═O)—O—, —O—C(═O)—, —CH2—CH2—, —C≡C—, —CH2—O—, —O—CH2—, —CH═N — or N═CH—;
• R3 is a linear or branched C1-50 alkylene group which may have one or more ethereal oxygen atoms between carbon atoms;
• and
• each of p and q, which are independent of each other, is 0 or 1.

A liquid crystal optical element, comprising:

• a pair of substrates with electrodes, of which at least one is transparent;
• and
• an electrooptical functional layer containing a liquid crystal and a polymer sandwiched between the substrates, and which is configured to exhibit a light beam transmitting state and a light beam scattering state by changing an alignment state of the liquid crystal in response to application of a voltage, wherein
• the polymer forms column resins, which include resins of which the major axis directions substantially agree with a normal direction of a plane of the substrates with electrodes, and resins which tilt from the normal direction;
• a content of the polymer in the electrooptical functional layer is at least 10 wt %;
• the alignment direction of the liquid crystal in the light beam transmitting state substantially agrees with the normal direction of the substrate plane;
• and
• among the column resins, the resins which tilt from the normal direction of the plane of the substrates with electrodes, have an average tilt angle of from 15 to 50°.

A liquid crystal optical element, comprising:

• a pair of substrates with electrodes, of which at least one is transparent;
• and
• an electrooptical functional layer containing a liquid crystal and a polymer sandwiched between the substrates, and which is configured to exhibit a light beam transmitting state and a light beam scattering state by changing an alignment state of the liquid crystal in response to application of a voltage, wherein
• the polymer forms column resins, which include resins of which the major axis directions substantially agree with a normal direction of a plane of the substrates with electrodes, and resins which tilt from the normal direction;
• a content of the polymer in the electrooptical functional layer is at least 10 wt %;
• the alignment direction of the liquid crystal in the light beam transmitting state substantially agrees with the normal direction of the substrate plane;
• and
• at least part of the column resins have a branched moiety;
• and
• at least part of the column resins having a branched moiety are connected to different column resins by means of the branched moiety.

A liquid crystal optical element, comprising:

• a pair of substrates with electrodes, of which at least one is transparent;
• and
• an electrooptical functional layer containing a liquid crystal and a polymer sandwiched between the substrates, and which is configured to exhibit a light beam transmitting state and a light beam scattering state by changing an alignment state of the liquid crystal in response to application of a voltage, wherein
• the polymer forms column resins, which include resins of which the major axis directions substantially agree with a normal direction of a plane of the substrates with electrodes, and resins which tilt from the normal direction;
• a content of the polymer in the electrooptical functional layer is at least 10 wt %;
• the alignment direction of the liquid crystal in the light beam transmitting state substantially agrees with the normal direction of the substrate plane;
• and
• the diameter of a cross-section vertical to the major axis direction of the column resins is from 0.05 to 1 μm.