Liquid crystal material composition and display device

Abstract

To provide a liquid crystal material composition that can prevent degradation of display quality.SOLUTION: A liquid crystal material composition comprises a liquid crystal mixture, a polymerization initiator, and a monomer mixture, wherein the monomer mixture comprises a first monomer compound having an acryloyl group at both terminals and a second monomer compound having an acryloyl group at only one terminal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a liquid crystal material composition and a display device. [Background technology]

[0002] Various lighting devices using polymer dispersed liquid crystal (PDLC) have been proposed. PDLC can switch between a scattering state that scatters incident light and a transparent state that transmits incident light. Because such display devices have high transmittance, they are expected to be used in a variety of fields. However, there is a demand for improved display quality in such display devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-248061 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present embodiment is to provide a liquid crystal material composition capable of suppressing degradation in display quality, and a display device capable of suppressing degradation in display quality. [Means for solving the problem]

[0005] According to one embodiment, a liquid crystal material composition includes a liquid crystal mixture, a polymerization initiator, and a monomer mixture, the monomer mixture including a first monomer compound having an acryloyl group at each end and a second monomer compound having an acryloyl group at only one end. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a plan view showing an example of the configuration of a display device DSP according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the configuration of the display device DSP shown in FIG. [Figure 3] FIG. 3 is a diagram for explaining an example of a method for manufacturing the display panel PNL shown in FIG. [Figure 4] FIG. 4 is a diagram for explaining an example of a method for manufacturing the display panel PNL shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present embodiment will be described below with reference to the drawings. The disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily make while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment for clarity of explanation, but these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, components that perform the same or similar functions as those described above with reference to the previous drawings are designated by the same reference numerals, and redundant detailed descriptions may be omitted as appropriate.

[0008] <Display device> FIG. 1 is a plan view showing an example of the configuration of the display device DSP of this embodiment. In one example, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other, but they may intersect at an angle other than 90 degrees. The first direction X and the second direction Y correspond to directions parallel to the main surfaces of the substrates constituting the display device DSP, and the third direction Z corresponds to the thickness direction of the display device DSP. In this specification, the direction from the first substrate SUB1 to the second substrate SUB2 is referred to as the "upper side" (or simply "up"), and the direction from the second substrate SUB2 to the first substrate SUB1 is referred to as the "lower side" (or simply "lower"). When referring to a "second member above the first member" and a "second member below the first member," the second member may be in contact with the first member or may be spaced apart from the first member. Furthermore, the tip of the arrow indicating the third direction Z is assumed to be an observation position for observing the display device DSP, and viewing from this observation position toward the XY plane defined by the first direction X and the second direction Y is referred to as planar viewing.

[0009] In this embodiment, the display device DSP is a display device that uses a polymer dispersed liquid crystal. The display device DSP includes a display panel PNL, an IC chip 1, a wiring substrate 2, a light emitting element LD, and a light guide element LG. The light guide element LG is omitted in FIG. 1.

[0010] The display panel PNL includes a first substrate SUB1, a second substrate SUB2, a liquid crystal layer LC, and a seal SE. The first substrate SUB1 and the second substrate SUB2 are formed in the shape of flat plates parallel to the XY plane. The first substrate SUB1 and the second substrate SUB2 overlap each other in a planar view. The first substrate SUB1 and the second substrate SUB2 are bonded together with the seal SE.

[0011] The liquid crystal layer LC is held between the first substrate SUB1 and the second substrate SUB2 and sealed with a seal SE. In Fig. 1, the liquid crystal layer LC and the seal SE are indicated by different diagonal lines.

[0012] As shown enlarged and schematically in FIG. 1, the liquid crystal layer LC comprises a polymer-dispersed liquid crystal containing a polymer 31 and a liquid crystal mixture 32. As will be described later, the polymer 31 is a polymer derived from a monomer mixture containing a first monomer compound having an acryloyl group at each end and a second monomer compound having an acryloyl group at only one end. The polymer 31 contains a polymer 31a derived mainly from the first monomer compound and a polymer 31b derived mainly from the second monomer compound. As will be described later, the liquid crystal mixture 32 contains at least one first liquid crystal compound, at least one second liquid crystal compound, and at least one third liquid crystal compound.

[0013] In the example shown in Fig. 1, the polymer 31 is formed in stripes extending along the first direction X. The liquid crystal mixture 32 is dispersed in the gaps between the polymer 31 and is oriented with its major axis aligned along the first direction X. Each of the polymer 31 and the liquid crystal mixture 32 has optical anisotropy or refractive index anisotropy. The responsiveness of the polymer 31 to an electric field is lower than that of the liquid crystal mixture 32 to an electric field.

[0014] In one example, the alignment direction of the polymer 31 hardly changes regardless of the presence or absence of an electric field. On the other hand, the alignment direction of the liquid crystal mixture 32 changes in response to an electric field when a high voltage equal to or greater than a threshold value is applied to the liquid crystal layer LC. When no voltage is applied to the liquid crystal layer LC, the optical axes of the polymer 31 and the liquid crystal mixture 32 are parallel to each other, and light incident on the liquid crystal layer LC is transmitted through the liquid crystal layer LC with almost no scattering within the liquid crystal layer LC (transparent state). When a voltage is applied to the liquid crystal layer LC, the optical axes of the polymer 31 and the liquid crystal mixture 32 intersect with each other, and light incident on the liquid crystal layer LC is scattered within the liquid crystal layer LC (scattered state). The liquid crystal layer LC is formed from a liquid crystal material composition, which will be described later.

[0015] The display panel PNL includes a display section DA that displays an image in an area where the first substrate SUB1 and the second substrate SUB2 overlap in a plan view, and a frame-shaped non-display section NDA that surrounds the display section DA. The seal SE is located in the non-display section NDA. The display section DA includes pixels PX arranged in a matrix in the first direction X and the second direction Y.

[0016] The first substrate SUB1 has an edge E1 extending along the first direction X. The second substrate SUB2 has an edge E2 extending along the first direction X. The edge E2 does not overlap the edge E1 in plan view. The first substrate SUB1 has an extending portion Ex extending from the edge E2 in the second direction Y in plan view. The extending portion Ex does not overlap the second substrate SUB2 in plan view.

[0017] The light emitting elements LD are connected to the wiring board 2. The light emitting elements LD are arranged at intervals in the first direction X and overlap the extending portion Ex in a plan view. The light emitting elements LD are, for example, light emitting diodes. Although not described in detail, the light emitting elements LD include a red light emitting portion, a green light emitting portion, and a blue light emitting portion.

[0018] As shown enlarged in FIG. 1, each pixel PX includes a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal layer LC, etc. The switching element SW is formed, for example, by a thin film transistor (TFT) and is electrically connected to a scanning line G and a signal line S. The scanning line G extends in a first direction X and is electrically connected to the switching element SW in each of the pixels PX aligned in the first direction X. The signal line S extends in a second direction Y, intersects the scanning line G, and is electrically connected to the switching element SW in each of the pixels PX aligned in the second direction Y. The pixel electrode PE is electrically connected to the switching element SW. Each pixel electrode PE faces the common electrode CE, and the liquid crystal layer LC is driven by an electric field generated between the pixel electrode PE and the common electrode CE. The capacitance CS is formed, for example, between an electrode having the same potential as the common electrode CE and an electrode having the same potential as the pixel electrode PE.

[0019] Fig. 2 is a cross-sectional view showing an example of the configuration of the display device DSP shown in Fig. 1. Here, a cross section of the display unit DA in the XZ plane defined by the first direction X and the third direction Z will be described.

[0020] The first substrate SUB1 includes a transparent substrate 10, insulating films 11, 12, and 13, a capacitance electrode 14, metal lines ML, signal lines S, pixel electrodes PE, and an alignment film AL1. The first substrate SUB1 further includes the switching elements SW and scanning lines G shown in FIG.

[0021] The transparent substrate 10 has a main surface (lower surface) 10A and a main surface (upper surface) 10B opposite to the main surface 10A. An insulating film 11 covers the main surface 10B. The signal lines S are arranged on the insulating film 11. The scanning lines G are arranged, for example, between the transparent substrate 10 and the insulating film 11. An insulating film 12 covers the signal lines S. Although not described in detail, the insulating film 12 is formed in a lattice shape overlapping the scanning lines G and the signal lines S. The capacitance electrodes 14 are arranged on the insulating film 12. The metal lines ML are arranged on the capacitance electrodes 14. Although not described in detail, the capacitance electrodes 14 and the metal lines ML are formed in a lattice shape overlapping the insulating film 12.

[0022] The insulating film 13 covers the insulating film 11, the capacitance electrode 14, and the metal line ML. The capacitance electrode 14 is provided between the insulating films 12 and 13. The pixel electrode PE is arranged for each pixel PX between the insulating film 13 and the alignment film AL1. The pixel electrode PE is electrically connected to the switching element SW. The pixel electrode PE faces the capacitance electrode 14 via the insulating film 13, and forms a capacitance CS of the pixel PX. The alignment film AL1 covers the pixel electrode PE and the insulating film 13.

[0023] The second substrate SUB2 includes a transparent substrate 20, a light-shielding layer BM, a common electrode CE, an alignment film AL2, and spacers PS.

[0024] The transparent substrate 20 has a main surface (lower surface) 20A and a main surface (upper surface) 20B opposite to the main surface 20A. The main surface 20A of the transparent substrate 20 faces the main surface 10B of the transparent substrate 10 and the alignment film AL1.

[0025] The light-shielding layer BM is provided, for example, between the principal surface 20A and the common electrode CE. The common electrode CE covers the principal surface 20A and the light-shielding layer BM. The spacers PS are arranged on the surface of the common electrode CE facing the liquid crystal layer LC, and penetrate the liquid crystal layer LC to contact the alignment film AL1. The alignment film AL2 covers the common electrode CE.

[0026] The alignment films AL1 and AL2 are horizontal alignment films having an alignment restriction force substantially parallel to the XY plane. In one example, the alignment films AL1 and AL2 are subjected to an alignment treatment along the first direction X. The alignment treatment may be a rubbing treatment or a photo-alignment treatment.

[0027] The liquid crystal layer LC is provided between the alignment film AL1 and the second substrate SUB2. In the example shown in Fig. 2, the liquid crystal layer LC is in contact with the alignment films AL1 and AL2.

[0028] The light guide element LG includes a transparent substrate 30. The transparent substrate 30 includes a main surface (lower surface) 30A and a main surface (upper surface) 30B opposite to the main surface 30A. The main surfaces 30A and 30B are surfaces that are approximately parallel to the XY plane. The main surface 30A faces the main surface 20B of the transparent substrate 20. The transparent substrate 30 is bonded to the transparent substrate 20.

[0029] The configurations of the display device DSP and the display panel PNL are not limited to the examples in Figures 1 and 2. For example, the display device DSP does not have to include the light guide element LG.

[0030] <Liquid Crystal Material Composition> The liquid crystal layer LC is made of a liquid crystal material composition, which includes a liquid crystal mixture, a polymerization initiator, and a monomer mixture.

[0031] [Liquid crystal mixture] The liquid crystal mixture comprises at least one first liquid crystal compound, at least one second liquid crystal compound, and at least one third liquid crystal compound.

[0032] [First liquid crystal compound] The first liquid crystal compound is a compound represented by formula (1).

[0033] [ka]

[0034] In formula (1), Ar 1 , Ar 2 , and Ar 3 are each independently a benzene ring or a naphthalene ring. 1 and Ar 2 Each of the benzene rings or naphthalene rings represented by the formula (I) is substituted with one to three halogen groups. The halogen groups may be the same or different from one another. The halogen groups are preferably, for example, fluoro groups or chloro groups.

[0035] In formula (1), Ar 3 The benzene ring or naphthalene ring represented by the formula (I) is substituted with one or more aliphatic groups. The aliphatic group is an aliphatic group having 1 to 10 carbon atoms, such as an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. 3 The benzene ring or naphthalene ring represented by the formula (I) may be further substituted with an organic group other than an aliphatic group.

[0036] In formula (1), Z 1 and Z 2 are each independently a single bond, a -CH2CH2- group, a -CHO- group, a -OCH2- group, a -CH2CH2O- group, a -OCH2CH2- group, a -CH2CH2CH2O- group, a -OCH2CH2CH2- group, a -CH=CH- group, a -C≡C- group, a -CF2O- group, a -OCF2- group, a -COO- group, or a -OCO- group.

[0037] In formula (1), Ar 1 can be expressed by, for example, any of the formulas (2-1) to (2-8).

[0038] [ka]

[0039] In formula (1), Ar 2 can be expressed by, for example, any of the formulas (3-1) to (3-11).

[0040] [ka]

[0041] In formula (1), Ar 3 can be expressed by, for example, formula (4-1) or (4-2).

[0042] [ka]

[0043] In formulas (4-1) and (4-2), R is an aliphatic group having 1 to 10 carbon atoms. The aliphatic group is, for example, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0044] [Second liquid crystal compound] The second liquid crystal compound is a compound represented by formula (5).

[0045] [ka]

[0046] In formula (5), Ar 1 and Ar 2 are each independently a benzene ring or a naphthalene ring. 1and Ar 2 Each of the benzene rings or naphthalene rings represented by the formula (I) is substituted with 1 to 3 halogen groups. The halogen groups may be the same or different from one another. The halogen groups are preferably, for example, fluoro groups or chloro groups.

[0047] In equation (5), A 1 is a 1,4-cyclohexyl group substituted with an aliphatic group at position 4. The aliphatic group is an aliphatic group having 1 to 10 carbon atoms, such as an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0048] In equation (5), Z 1 is a single bond, -CH2CH2- group, -CH2O- group, -OCH2- group, -CH2CH2O- group, -OCH2CH2- group, -CH2CH2CH2CH2O- group, -OCH2CH2CH2CH2- group, -CH=CH- group, -C≡C- group, -CF2O- group, -OCF2- group, -COO- group or -OCO- group.

[0049] In equation (5), Z 3 is a single bond, a -CH2CH2- group, a -CHO- group, a -OCH2- group, a -CH2CH2O- group, a -OCH2CH2- group, a -CH2CH2CH2O- group, a -OCH2CH2CH2- group, a -CH=CH- group, a -C≡C- group, a -CF2O- group, a -OCF2- group, a -COO- group, a -OCO- group or a 1,4-cyclohexylene group.

[0050] In formula (5), Ar 1 can be expressed by, for example, any of the formulas (2-1) to (2-8).

[0051] In formula (5), Ar 2 can be expressed by, for example, any of the formulas (3-1) to (3-11).

[0052] In equation (5), A 1 can be expressed by, for example, equation (6).

[0053] [ka]

[0054] In the above formula (6), R is an aliphatic group having 1 to 10 carbon atoms. The aliphatic group is, for example, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0055] [Third liquid crystal compound] The third liquid crystal compound is a compound represented by formula (7).

[0056] [ka]

[0057] In formula (7), Ar 4 and Ar 5 are each independently a phenylene group or a naphthylene group. 4 and Ar 5 Each of the phenylene or naphthylene groups represented by the formula (I) may be substituted with one or more halogen groups. The halogen groups may be the same or different from one another. The halogen groups are preferably, for example, fluoro or chloro groups.

[0058] In equation (7), A 2 and A 3 are each independently a 1,4-cyclohexyl group substituted with an aliphatic group at position 4. The aliphatic group is an aliphatic group having 1 to 10 carbon atoms, such as an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0059] In equation (7), Z 4 , Z 5 and Z 6are each independently a single bond, a -CH2CH2- group, a -CHO- group, a -OCH2- group, a -CH2CH2O- group, a -OCH2CH2- group, a -CH2CH2CH2O- group, a -OCH2CH2CH2- group, a -CH=CH- group, a -C≡C- group, a -CF2O- group, a -OCF2- group, a -COO- group, or a -OCO- group.

[0060] In formula (7), Ar 4 can be expressed by, for example, formula (8-1) or (8-2).

[0061] [ka]

[0062] In formula (7), Ar 5 can be expressed by, for example, any of the formulas (9-1) to (9-6).

[0063] [ka]

[0064] In equation (7), A 2 can be expressed by, for example, equation (10).

[0065] [ka]

[0066] In equation (7), A 3 can be expressed by, for example, equation (11).

[0067] [ka]

[0068] In the above formulas (10) and (11), R is an aliphatic group having 1 to 10 carbon atoms. The aliphatic group is, for example, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0069] The liquid crystal mixture includes at least one first liquid crystal compound, at least one second liquid crystal compound, and at least one third liquid crystal compound. When the total weight of the first, second, and third liquid crystal compounds included in the liquid crystal mixture is 100 parts by weight, the liquid crystal mixture includes each of the first, second, and third liquid crystal compounds in an amount ranging from 5 to 50 parts by weight. The liquid crystal mixture includes, for example, 1 to 10 first liquid crystal compounds, 1 to 5 second liquid crystal compounds, and 1 to 5 third liquid crystal compounds.

[0070] [Monomer mixture] The liquid crystal material composition includes a monomer mixture, which includes a first monomer compound having an acryloyl group at each end, and a second monomer compound having an acryloyl group at only one end.

[0071] The first monomer compound is represented by formula (12):

[0072] [ka]

[0073] (Z in Eq. (12) 7 and Z 9 are each independently an alkylene group having 1 to 10 carbon atoms, Z in equation (12) 8-CH2CH2- group, -CH2O- group, -OCH2- group, -CH2CH2O- group, -OCH2CH2- group, -CH2CH2CH2O- group, -OCH2CH2CH2- group, -CH2CH2OCO- group, -CO OCH2CH2- group, -CH2CH2COO- group, -OCOCH2CH2- group, -CH=CH- group, -C≡C- group, -CF2O- group, -OCF2- group, -COO- group, -OCO- group or phenylene group, and Z 8 The phenylene group represented by the formula (I) may be substituted with at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, and a halogen group, Ar in formula (12) 6 and Ar 7 are each independently a phenylene group, and Ar 6 and Ar 7 Each of the phenylene groups represented by the formula (13) can be an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, a halogen group, and a phenyl group represented by the formula (13)

[0074] [ka]

[0075] (Z in Eq. (13) 10 is an alkylene group having 1 to 10 carbon atoms; Z in equation (12) 8 , Ar 6 and Ar 7 may be the same group or different groups, In formula (12), j is 0, 1, 2 or 3.

[0076] The first monomer compound is, for example, a compound represented by any one of formulas (14-1) to (14-14).

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] In formulae (14-1) to (14-14), g and h each independently represent an integer of 1 to 10.

[0081] The second monomer compound is represented by formula (15):

[0082] [ka]

[0083] (Z in Eq. (15) 11 and Z 13 are each independently an alkylene group having 1 to 10 carbon atoms, Z in equation (15) 12 -CH2CH2- group, -CH2O- group, -OCH2- group, -CH2CH2O- group, -OCH2CH2- group, -CH2CH2CH2O- group, -OCH2CH2CH2- group, -CH2CH2OCO- group, -CO OCH2CH2- group, -CH2CH2COO- group, -OCOCH2CH2- group, -CH=CH- group, -C≡C- group, -CF2O- group, -OCF2- group, -COO- group, -OCO- group, or phenylene group, and Z 12 The phenylene group represented by the formula (I) may be substituted with at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, and a halogen group, Ar in formula (15) 8 and Ar 9 are each independently a phenylene group, and Ar 8 and Ar 9 Each of the phenylene groups represented by the formula (16) can be an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, a halogen group, and a phenyl group represented by the formula (16)

[0084] [ka]

[0085] (Z in Eq. (16) 14 is an alkylene group having 1 to 10 carbon atoms; The multiple Z in Eq. (15) 12 , Ar 8 and Ar 9 may be the same group or different groups, In formula (15), k is 0, 1, 2 or 3.

[0086] The second monomer compound is, for example, a compound represented by any one of formulas (17-1) to (17-14).

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] In formulae (17-1) to (17-14), g and h each independently represent an integer of 1 to 10.

[0091] The monomer mixture includes a first monomer compound and a second monomer compound. The monomer mixture includes one or more compounds represented by formula (13) as the first monomer compound. The monomer mixture includes one or more compounds represented by formula (15) as the second monomer compound. It is preferred that the monomer mixture includes one compound represented by formula (13) as the first monomer compound and one compound represented by formula (15) as the second monomer compound.

[0092] In the first monomer compound and the second monomer compound contained in the monomer mixture, Z in formula (13) 7 and Z in Eq. (15) 11 and Z in formula (13) are preferably the same group. 8 and Z in Eq. (15) 12 and Z in formula (13) are preferably the same group. 9 and Z in Eq. (15) 13 It is preferable that Ar in formula (13) are the same group. 6 and Ar in Eq. (15) 8 It is preferable that Ar in formula (13) are the same group. 7 and Ar in Eq. (15) 9 It is preferable that j in formula (13) and k in formula (15) are the same group.

[0093] The combination of the first monomer compound and the second monomer compound contained in the monomer mixture is a combination of a compound represented by formula (13-1) and a compound represented by formula (15-1), a combination of a compound represented by formula (13-2) and a compound represented by formula (15-2), a combination of a compound represented by formula (13-3) and a compound represented by formula (15-3), a combination of a compound represented by formula (13-4) and a compound represented by formula (15-4), a combination of a compound represented by formula (13-5) and a compound represented by formula (15-5), a combination of a compound represented by formula (13-6) and a compound represented by formula (15-6), a combination of a compound represented by formula (13-7) and a compound represented by formula (15-7), a combination of a compound represented by formula (13-8) and a compound represented by formula (15-8), a combination of a compound represented by formula (13-9) and a compound represented by formula (15-9), a combination of a compound represented by formula (13-10) and a compound represented by formula (15-10), a combination of a compound represented by formula (13-11) and a compound represented by formula (15-11), a combination of a compound represented by formula (13-12) and a compound represented by formula (15-12), a combination of a compound represented by formula (13-13) and a compound represented by formula (15-13), or a combination of a compound represented by formula (13-14) and a compound represented by formula (15-14).

[0094] Depending on the combination of monomer compounds contained in the monomer mixture, the compatibility between the monomer compounds may be low. If the compatibility between the monomer compounds is low, an additional step for making the monomer compounds compatible may be required in the production of the display panel PNL, which will be described later, and this may make the production of the display panel PNL more complicated.

[0095] As mentioned above, in equation (13), Z 7 , Z 8 , Z 9 , Ar 6 and Ar 7 and each of the groups represented by the formula (15) 11 , Z 12 , Z 13 , Ar 8 and Ar 9and the groups represented by the formula (13) are the same, it is possible to prevent the compatibility between the first monomer compound and the second monomer compound contained in the monomer mixture from decreasing. Furthermore, as described above, it is possible to prevent the compatibility between the first monomer compound and the second monomer compound contained in the monomer mixture from decreasing by making j in formula (13) and k in formula (15) the same.

[0096] The content (mol %) of the first monomer compound contained in the monomer mixture is preferably higher than the content (mol %) of the second monomer compound.

[0097] As will be described later, in the manufacture of the display panel PNL, a liquid crystal material composition is introduced between the alignment films AL1 and AL2. At this time, the first and second monomer compounds are aligned in the same direction as the liquid crystal mixture 32 (e.g., the first direction X) due to the alignment restraining force of the alignment films AL1 and AL2. A polymer 31 is obtained by polymerizing such a monomer mixture containing the first and second monomer compounds. The polymer 31 includes a polymer 31a derived mainly from the first monomer compound and a polymer 31b derived mainly from the second monomer compound. The polymer 31a derived mainly from the first monomer compound has a structure in which both ends of the first monomer compound are sequentially bonded and a structural unit derived from the first monomer compound is introduced into the main chain. The polymer 31a has, for example, a repeating structural unit represented by formula (18).

[0098] [ka]

[0099] In equation (18), Z 7 , Z 8 , Z 9 , Ar 6 , Ar 7 and j are as defined in the above formula (13).

[0100] Polymer 31b derived mainly from the second monomer compound has a structure in which one end of the second monomer compound is sequentially bonded and a structural unit derived from the second monomer compound is introduced into the side chain. Polymer 31b has, for example, a repeating unit represented by formula (19).

[0101] [ka]

[0102] In equation (19), Z 11 , Z 12 , Z 13 , Ar 8 , Ar 9 and k are as defined in the above formula (15).

[0103] [Polymerization initiator] The liquid crystal material composition contains a polymerization initiator, such as a thermal polymerization initiator or a photopolymerization initiator.

[0104] The thermal polymerization initiator is, for example, a compound that generates active species when heated to a temperature of 80° C. or higher. The thermal polymerization initiator is, for example, a thermal radical polymerization initiator or a thermal cationic polymerization initiator.

[0105] The thermal radical polymerization initiator includes, for example, an azo-based compound or a peroxide-based compound.

[0106] Examples of the azo compound include 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2-methylbutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(2-methylpropionate) dimethyl, 2,2′-azobis(2-methylpropionamidine) dihydrochloride, 2,2′-azobis(2-methylpropionamidine) dihydrochloride, and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride.

[0107] The peroxide compound is, for example, tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, or benzoyl peroxide.

[0108] Examples of the thermal cationic polymerization initiator include dicyandiamide, cyclohexyl p-toluenesulfonate, diphenyl(methyl)sulfonium tetrafluoroborate, benzyl(4-hydroxyphenyl)methylsulfonium hexafluoroantimonate, and (4-hydroxyphenyl)methyl(2-methylbenzyl)sulfonium hexafluoroantimonate.

[0109] A photopolymerization initiator is a compound that generates active species when irradiated with light, such as ultraviolet light. The photopolymerization initiator is, for example, a compound that generates active species by absorbing light having a wavelength of 350 nm to 380 nm. The photopolymerization initiator is, for example, a photoradical polymerization initiator, a photocationic polymerization initiator, or a photoanionic polymerization initiator.

[0110] The photoradical polymerization initiator includes, for example, a benzophenone-based compound, an acetophenone-based compound, a benzoin-based compound, a thioxanthone-based compound, or a phosphine oxide-based compound.

[0111] Examples of benzophenone compounds include benzophenone, 4-benzoylbenzoic acid, 2-benzoylbenzoic acid, methyl 2-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-dichlorobenzophenone, 1,4'-dibenzoylbenzene, 4-methylbenzophenone, hydroxybenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4-methoxy-3,3'-dimethylbenzophenone, 4-benzoyl4'-methyldiphenyl sulfide, and 4,4'-carbonylbis(di-tert-butyl diperoxyphthalate).

[0112] Examples of acetophenone compounds include acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-isonitrosopropiophenone, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one.

[0113] Examples of benzoin-based compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone, 2,2-diethoxyacetophenone, and 2,2-dimethoxy-2-phenylacetophenone.

[0114] The thioxanthone compound is, for example, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-isopropylthioxanthone, or 2,4-diethylthioxanthen-9-one.

[0115] Examples of the phosphine oxide compound include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate.

[0116] In addition to the compounds described above, the photoradical polymerization initiator may be (±)-camphorquinone, benzil, methyl benzoylformate, p-anisil, 2-ethylanthraquinone, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, or 1-(9-ethyl-9H-carbazol-3-yl)ethanone O-acetyloxime.

[0117] The photocationic polymerization initiator includes, for example, an iodonium salt-based compound, a sulfonium salt-based compound, or a triazine-based compound.

[0118] Examples of the iodonium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, bis(4-tert-butylphenyl)iodonium triflate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, and 4-isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate.

[0119] Examples of sulfonium salt compounds include cyclopropyldiphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, triphenylsulfonium tetrafluoroborate, tri-p-tolylsulfonium trifluoromethanesulfonate, and tri-p-tolylsulfonium hexafluorophosphate.

[0120] Examples of the triazine compound include 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(1,3-benzodioxol-5-yl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-dimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(furan-2-yl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine.

[0121] The cationic photopolymerization initiator may be 4-nitrobenzenediazonium tetrafluoroborate in addition to the above-mentioned compounds.

[0122] Examples of the photoanionic polymerization initiator include 2-(9-oxoxanthen-2-yl)propionic acid 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 2-(9-oxoxanthen-2-yl)propionic acid 1,5-diazabicyclo[4.3.0]non-5-ene, 2-(9-oxoxanthen-2-yl)propionic acid 1,8-diazabicyclo[5.4.0]undec-7-ene, acetophenone O-benzoyloxime, 2-nitrobenzyl cyclohexylcarbamate, 1,2-bis(4-methoxyphenyl)-2-oxoethyl cyclohexylcarbamate, and nifedipine.

[0123] It is preferable to use a photopolymerization initiator as the polymerization initiator, which allows the monomer mixture to be easily polymerized by irradiating the liquid crystal material composition with ultraviolet light in the production of the display panel PNL described below.

[0124] The amount of the polymerization initiator contained in the liquid crystal material composition is, for example, 0.1 to 30% by weight, preferably 1 to 20% by weight, and more preferably 5 to 15% by weight, based on the monomer mixture.

[0125] According to this embodiment, it is possible to suppress a decrease in the display quality of the display panel PNL.

[0126] In the display device DSP, when no voltage is applied to the liquid crystal layer LC, the alignment directions of the polymer 31 and the liquid crystal mixture 32 are the same, and their optical axes are parallel to each other. Therefore, light incident on the liquid crystal layer LC is transmitted through the liquid crystal layer LC with almost no scattering within the liquid crystal layer LC (transparent state). When a voltage is applied to the liquid crystal layer LC, the alignment direction of the polymer 31 does not change, but the alignment direction of the liquid crystal mixture 32 does change. As a result, the optical axes of the polymer 31 and the liquid crystal mixture 32 intersect with each other, and the light incident on the liquid crystal layer LC is scattered within the liquid crystal layer LC (scattered state).

[0127] In the display device DSP in the transparent state, if there is a portion where the alignment directions of the polymer 31 and the liquid crystal mixture 32 do not match, the optical axes of the polymer 31 and the liquid crystal mixture 32 will not be parallel to each other, which may cause undesired scattering of light. Furthermore, if the alignment of the polymer 31 is unstable, the alignment direction of the polymer 31 may change when a voltage is applied to the liquid crystal layer LC, which may result in a deterioration in the display quality of the display panel PNL.

[0128] The liquid crystal material composition according to this embodiment includes a monomer mixture containing a first monomer compound having an acryloyl group at each end and a second monomer compound having an acryloyl group at only one end, and a polymer 31 derived from the monomer mixture contains a polymer 31a derived mainly from the first monomer compound and a polymer 31b derived mainly from the second monomer compound.

[0129] The polymer 31a derived mainly from the first monomer compound has a structure in which a structural unit derived from the first monomer compound is introduced into the main chain, as shown in formula (15). Since both ends of the structural unit of such polymer 31a are fixed by bonds, the orientation stability is high, and the orientation of polymer 31 can be prevented from becoming unstable.

[0130] On the other hand, polymer 31b, which is mainly composed of the second monomer compound, has a structure in which a structural unit derived from the second monomer compound is introduced into the side chain, as shown in formula (16). The side chain of such polymer 31b has a flexible structure, so that it is likely to be aligned in the same direction as liquid crystal mixture 32 along the alignment restraining force of alignment film AL, and the alignment directions are likely to coincide. Therefore, in the display device DSP in the transparent state, the optical axes of polymer 31 and liquid crystal mixture 32 can be prevented from being misaligned with each other.

[0131] As described above, according to this embodiment, it is possible to prevent the orientation of the polymer 31 from becoming unstable, and also possible to prevent the optical axes of the polymer 31 and the liquid crystal mixture 32 from becoming non-parallel to each other. Therefore, according to this embodiment, it is possible to prevent a decrease in the display quality of the display panel PNL.

[0132] Next, an example of a manufacturing method of the display panel PNL shown in Fig. 1 will be described. Fig. 3 and Fig. 4 are schematic cross-sectional views each showing a part of the manufacturing process of the display panel PNL. In Fig. 3 and Fig. 4, the insulating films 11, 12, and 13, the capacitance electrode 14, the metal wire ML, the signal line S, the switching element SW, and the scanning line G are omitted.

[0133] In manufacturing the display panel PNL, as shown in the upper left of Fig. 3, pixel electrodes PE and the like are formed on the main surface 10B of the transparent substrate 10, and an alignment film AL1 is formed thereon to form a first substrate SUB1. Also, as shown in the upper right of Fig. 3, a common electrode CE and the like are formed on the main surface 20A of the transparent substrate 20, and an alignment film AL2 is formed thereon to form a second substrate SUB2 (step P1). An alignment treatment is performed on the alignment films AL1 and AL2.

[0134] After step P1, as shown in the lower part of Figure 3, the first substrate SUB1 and the second substrate SUB2 are arranged with a gap 40 between them so that the main surface 10B and the main surface 20A face each other, and are bonded together with a seal SE while the gap 40 is formed (step P2).

[0135] After step P2, as shown in the upper part of Fig. 4, a liquid crystal material composition 50 is introduced into the gap 40 (step P3). Although not shown, the liquid crystal mixture 32, the first monomer compound, and the second monomer compound contained in the liquid crystal material composition 50 are aligned in the same direction (for example, the first direction X) by the alignment regulating forces of the alignment films AL1 and AL2.

[0136] After step P3, as shown in the lower part of FIG. 4, the monomer mixture contained in the liquid crystal material composition 50 introduced into the gap 40 is polymerized to form a liquid crystal layer LC (step P4).

[0137] In step P4, if the polymerization initiator contained in the liquid crystal material composition 50 is a thermal polymerization initiator, the monomer mixture is polymerized by heating the liquid crystal material composition 50 introduced into the gap 40. The heating temperature is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher.

[0138] In step P4, if the polymerization initiator contained in the liquid crystal material composition 50 is a photopolymerization initiator, the liquid crystal material composition 50 is irradiated with light, for example, ultraviolet light, to polymerize the monomer mixture.

[0139] Examples of light sources that can be used for irradiating ultraviolet light include metal halide lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and UV-LED lamps. The wavelength of the irradiated ultraviolet light is preferably within the absorption wavelength range of the photopolymerization initiator, but not within the absorption wavelength range of the liquid crystal mixture 32 contained in the liquid crystal material composition 50. When a metal halide lamp, high-pressure mercury lamp, or ultra-high-pressure mercury lamp is used as the light source, it is preferable to irradiate the liquid crystal material composition with light that filters out ultraviolet light having a wavelength of 330 nm or less, and it is more preferable to irradiate the liquid crystal material composition with light that filters out ultraviolet light having a wavelength of 350 nm or less.

[0140] The exposure dose of ultraviolet light irradiated onto the liquid crystal material composition 50 is 10 to 10,000 mJ / cm 2 is preferred, and 50 to 5000 mJ / cm 2 is more preferred.

[0141] The illuminance of the ultraviolet light irradiated onto the liquid crystal material composition 50 is 1 to 200 mW / cm 2 is preferred, and 2 to 100 mW / cm 2 is more preferred.

[0142] The time for irradiating the liquid crystal material composition 50 with ultraviolet light is appropriately selected depending on the intensity of the ultraviolet light to be irradiated.

[0143] In one example, the illuminance is 2 to 100 mW / cm 2The liquid crystal material composition 50 is irradiated with ultraviolet light of 1200 mJ / cm for 10 to 600 seconds, and the exposure amount is 1200 mJ / cm 2 ~2400mJ / cm 2 It is preferable to set the following.

[0144] In the above example, liquid crystal material composition 50 is injected into gap 40 after first substrate SUB1 and second substrate SUB2 are bonded together, but this is not limiting. For example, before bonding first substrate SUB1 and second substrate SUB2 together, a loop-shaped seal SE may be formed on first substrate SUB1, liquid crystal material composition 50 may be dispensed inside the area surrounded by seal SE, second substrate SUB2 may be superimposed on liquid crystal material composition 50, and the first substrate SUB1 and second substrate SUB2 may then be bonded together.

[0145] As described above, according to this embodiment, it is possible to provide a display device capable of suppressing degradation in display quality.

[0146] In this embodiment, for example, the transparent substrate 10 corresponds to a first transparent substrate, and the transparent substrate 20 corresponds to a second transparent substrate.

[0147] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be created by appropriately combining multiple components disclosed in each embodiment. For example, some components may be omitted from all the components shown in each embodiment. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0148] DSP...Display device PNL...Display panel SE...Seal DA...Display area NDA...Non-display area PX...Pixel LC...liquid crystal layer 31...polymer 32...liquid crystal mixture LG: Light guide element LD: Light emitting element SW: Switching element PE: Pixel electrode CE: Common electrode G...Scanning line S...Signal line 10...Transparent substrate 20...Transparent substrate 30...Transparent substrate AL...Alignment film LC...Liquid crystal layer

Claims

1. a liquid crystal mixture, a polymerization initiator, and a monomer mixture; The monomer mixture comprises a first monomer compound having an acryloyl group at each end, and a second monomer compound having an acryloyl group at only one end.

2. The first monomer compound is represented by formula (1) 【Chemical 1】 (The Z in the formula (1) ７ and Z ９ are each independently an alkylene group having 1 to 10 carbon atoms, The Z ８ is -CH ２ CH ２ - group, -CH ２ O- group, —OCH ２ - group, -CH ２ CH ２ O- group, —OCH ２ CH ２ - group, -CH ２ CH ２ CH ２ O- group, —OCH ２ CH ２ CH ２ - group, -CH ２ CH ２ OCO- group, -COOCH ２ CH ２ - group, -CH ２ CH ２ COO- group, -OCOCH ２ CH ２ - group, -CH=CH- group, -C≡C- group, -CF ２ O-group, —OCF ２ - group, -COO- group, -OCO- group or phenylene group, ８ The phenylene group represented by the formula (I) may be substituted with at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, and a halogen group, The Ar of the formula (1) ６ and Ar ７ are each independently a phenylene group, and ６ and Ar ７ Each of the phenylene groups represented by the formula (2) can be an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, a halogen group, or a phenyl group represented by the formula (2) 【Chemistry 2】 (The Z in the formula (2) １０ is an alkylene group having 1 to 10 carbon atoms; The Z ８ , the Ar ６ and the Ar ７ may be the same group or different groups, The liquid crystal material composition according to claim 1 , wherein the compound is a compound represented by the formula (1):

3. The second monomer compound is represented by formula (3): 【Chemistry 3】 (The Z in the formula (3) １１ and Z １３ are each independently an alkylene group having 1 to 10 carbon atoms, The Z １２ is -CH ２ CH ２ - group, -CH ２ O- group, —OCH ２ - group, -CH ２ CH ２ O- group, —OCH ２ CH ２ - group, -CH ２ CH ２ CH ２ O- group, —OCH ２ CH ２ CH ２ - group, -CH ２ CH ２ OCO- group, -COOCH ２ CH ２ - group, -CH ２ CH ２ COO- group, -OCOCH ２ CH ２ - group, -CH=CH- group, -C≡C- group, -CF ２ O-group, —OCF ２ - group, -COO- group, -OCO- group, or phenylene group, １２ The phenylene group represented by the formula (I) may be substituted with at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, and a halogen group, The Ar of the formula (3) ８ and the Ar ９ are each independently a phenylene group, and ８ and the Ar ９ Each of the phenylene groups represented by the formula (4) can be an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a phenyl group, a halogen group, or a phenylene group represented by the formula (4) 【Chemistry 4】 (The Z in the formula (4) １４ is an alkylene group having 1 to 10 carbon atoms; The plurality of Z １２ , the Ar ８ and the Ar ９ may be the same group or different groups, The liquid crystal material composition according to claim 2, wherein the compound is represented by the formula (3), wherein k is 0, 1, 2, or 3.

4. In the formula (1) and the formula (3), Said Z ７ and the Z １１ and are the same group, Said Z ８ and the Z １２ and are the same group, Said Z ９ and the Z １３ and are the same group, The Ar ６ and the Ar ８ and are the same group, The Ar ７ and the Ar ９ and are the same group, 4. The liquid crystal material composition according to claim 3, wherein j and k are the same.

5. 2. The liquid crystal material composition according to claim 1, wherein the content (mol %) of the first monomer compound contained in the monomer mixture is greater than the content (mol %) of the second monomer compound.

6. The liquid crystal material composition according to claim 1 , wherein the polymerization initiator is a photopolymerization initiator.

7. a first substrate including a first transparent substrate and an alignment film disposed on the first transparent substrate; a second substrate facing the alignment film; a liquid crystal layer disposed between the alignment film and the second substrate, the liquid crystal layer including a liquid crystal mixture and a polymer; The polymer is derived from a monomer mixture containing a first monomer compound having an acryloyl group at each end and a second monomer compound having an acryloyl group at only one end.

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