Composition for polarizing film, polarizing film, and flexible device

Abstract

The composition for a polarizing film according to embodiments of the present invention comprises: a polyolefin resin; and a dichroic dye comprising a compound having a structure represented by a specific chemical formula. Accordingly, a polarizing film having an improved polarization efficiency and dichroic ratio can be manufactured.

Description

Composition for polarizing film, polarizing film and flexible device

[0001] The present invention relates to a composition for a polarizing film, a polarizing film, and a flexible device. More specifically, the present invention relates to a composition for a polarizing film comprising heterogeneous components, a polarizing film formed therefrom, and a flexible device comprising the polarizing film.

[0002] Recently, with the advancement of multimedia, the need for display devices capable of displaying these images has increased. To meet this need, development of large-format, affordable, and high-quality flat-panel display devices is underway. Examples include liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays.

[0003] In addition, recently, there has been an increasing demand for flexible flat panel display devices (hereinafter simply referred to as flexible display devices) manufactured using flexible materials such as flexible plastic or metal foil as a substrate so that display performance can be maintained even when bent.

[0004] The above-described display devices have a polarizing plate attached to the outside of the display panel. The polarizing plate allows only light vibrating in a specific direction to pass through and absorbs or reflects other light, thereby controlling the direction of light incident on or emitted from the display panel.

[0005] A polarizing plate generally includes a polarizer and a protective layer to protect it. The polarizer may be made of, for example, iodine or a dichroic dye adsorbed and oriented in polyvinyl alcohol (PVA), and the protective layer may be made of, for example, triacetyl cellulose (TAC).

[0006] However, polarizing plates containing polarizers and protective layers are not only complex and expensive to produce, but also increase the thickness of the polarizing plate, potentially affecting the thickness of the display device. Accordingly, research is being conducted into polarizing films that do not require a protective layer.

[0007] For example, U.S. Patent Publication No. 2012-0050652, Korean Patent Publication No. 10-2015-0052681, and Korean Patent Publication No. 10-2014-0059145 disclose compositions for polarizing films and polarizing films manufactured using the same, but there is a problem that the polarizing efficiency and dichroic ratio of the polarizing films are insufficient.

[0008] One object of the present invention is to provide a composition for producing a polarizing film having improved polarization efficiency and dichroic ratio.

[0009] One object of the present invention is to provide a polarizing film manufactured using the above composition.

[0010] One object of the present invention is to provide a method for manufacturing the polarizing film.

[0011] One object of the present invention is to provide a flexible device including the polarizing film.

[0012] A composition for a polarizing film according to an exemplary embodiment may include a polyolefin resin; and a dichroic dye including a compound having a structure represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014]

[0015] In chemical formula 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 20 carbon atoms, and the arylene group is substituted or not substituted with a halogen atom,

[0016] R 1 is an alkoxy group having 1 to 24 carbon atoms,

[0017] R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 14-membered heteroaryl group containing at least one nitrogen atom, a 5 to 14-membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group,

[0018] The above heterocycloalkenyl group may be substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0019] In some embodiments, Ar in the above formula 1 1 Inland Ar 3 are each independently an arylene group having 6 to 12 carbon atoms, and the arylene group is substituted or not substituted with a halogen atom,

[0020] R 1 is an alkoxy group having 1 to 12 carbon atoms,

[0021] R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 10 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group,

[0022] The above heterocycloalkenyl group may be substituted or unsubstituted with an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0023] In some embodiments, Ar in the above formula 1 1 Inland Ar 3 are each independently an arylene group having 6 to 10 carbon atoms, and the arylene group is substituted or not substituted with a chlorine atom,

[0024] R 1 is an alkoxy group having 1 to 8 carbon atoms,

[0025] R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 6 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group,

[0026] The above heterocycloalkenyl group may be substituted or unsubstituted with an alkyl group or phenyl group having 1 to 3 carbon atoms.

[0027] In some embodiments, the compound having a structure represented by Chemical Formula 1 may include a compound having a structure represented by any one of Chemical Formulas 2 to 13 below.

[0028] [Chemical Formula 2]

[0029]

[0030] [Chemical Formula 3]

[0031]

[0032] [Chemical Formula 4]

[0033]

[0034] [Chemical Formula 5]

[0035]

[0036] [Chemical Formula 6]

[0037]

[0038] [Chemical Formula 7]

[0039]

[0040] [Chemical Formula 8]

[0041]

[0042] [Chemical Formula 9]

[0043]

[0044] [Chemical Formula 10]

[0045]

[0046] [Chemical Formula 11]

[0047]

[0048] [Chemical Formula 12]

[0049]

[0050] [Chemical Formula 13]

[0051]

[0052] In some embodiments, the polyolefin resin may include at least one selected from the group consisting of polyethylene, polypropylene, and polyethylene-polypropylene copolymers.

[0053] In some embodiments, the polyolefin resin may comprise polypropylene and a polyethylene-polypropylene copolymer in a weight ratio of 1:9 to 9:1.

[0054] In some embodiments, the content of the dichroic dye may be 0.05 parts by weight to 2 parts by weight per 100 parts by weight of the polyolefin resin.

[0055] A polarizing film according to an exemplary embodiment may include a polyolefin resin; and a dichroic dye including a compound having a structure represented by the above chemical formula 1.

[0056] In some embodiments, the polarizing film may have a dichroic ratio of 6 to 10.

[0057] In some embodiments, the polarizing film can have a polarization efficiency of 85% or greater in the wavelength range of 380 nm to 780 nm.

[0058] According to a method for manufacturing a polarizing film according to an exemplary embodiment, the composition for a polarizing film of the above-described embodiments is melted, the molten mixture is placed in a mold and pressed to manufacture a sheet, and the sheet can be uniaxially stretched.

[0059] In some embodiments, the step of uniaxially stretching the sheet may include stretching the sheet at an elongation of 300% to 1000%.

[0060] A flexible device according to an exemplary embodiment may include a flexible display panel; and a polarizing film of the above-described embodiments positioned on the display panel.

[0061] A composition for a polarizing film according to exemplary embodiments of the present invention comprises a dichroic dye comprising a compound represented by a specific chemical formula, and a polarizing film can be manufactured using the composition.

[0062] Since the above dichroic dye has high orientation, the polarizing film can have improved polarization efficiency and dichroic ratio, and can also be usefully used in flexible devices.

[0063] FIG. 1 is a schematic cross-sectional view illustrating a flexible device including a polarizing film according to exemplary embodiments.

[0064] Embodiments of the present invention provide a composition for a polarizing film comprising a dichroic dye comprising a compound represented by the following chemical formula 1. Embodiments of the present invention also provide a polarizing film and a flexible device manufactured using the composition.

[0065] The present invention will be described in more detail with reference to the drawings and examples below. However, the following drawings and examples attached and described in this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in such drawings and examples.

[0066] A composition for a polarizing film according to exemplary embodiments may include a polyolefin resin; and a dichroic dye including a compound having a structure represented by the following chemical formula 1. When a polarizing film is manufactured using the composition, the polarization efficiency and dichroic ratio of the polarizing film may be improved.

[0067] For example, the polyolefin resin is one of the polymer resins that can be melt-blended and made into a film, and can have an average light transmittance of about 85% or more in the visible light range.

[0068] In some embodiments, the polyolefin resin may include at least one selected from the group consisting of polyethylene, polypropylene, and a polyethylene-polypropylene copolymer. For example, the polyolefin resin may be a mixture of polypropylene and a polyethylene-polypropylene copolymer.

[0069] In some embodiments, the polyolefin resin may comprise polypropylene and a polyethylene-polypropylene copolymer in a weight ratio of 1:9 to 9:1. For example, the weight ratio of polypropylene and a polyethylene-polypropylene copolymer may be 2:8 to 8:2, 3:7 to 7:3, or 6:4 to 4:6.

[0070] Within the above range, a polarizing film having improved mechanical strength while preventing crystallization of polypropylene and improved polarization efficiency and dichroic ratio can be obtained.

[0071] In some embodiments, the solubility parameter of the polyolefin resin may be 15 to 18. The solubility parameter is a numerical value indicating the degree of interaction between two or more types of compounds. A smaller difference in the solubility parameters between compounds means a greater interaction, and a larger difference in the solubility parameters between compounds means a smaller interaction.

[0072] The above polyolefin resin may be replaced with another resin having similar physical and optical properties. For example, it may be replaced with a polyester resin such as polyethylene terephthalate, polyethylene terephthalate glycol, or polyethylene naphthalate.

[0073] In some embodiments, the dichroic dye may include a compound having a structure represented by the following chemical formula 1.

[0074] [Chemical Formula 1]

[0075]

[0076] In chemical formula 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 20 carbon atoms, and the arylene group is substituted or not substituted with a halogen atom,

[0077] R 1 is an alkoxy group having 1 to 24 carbon atoms,

[0078] R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 14-membered heteroaryl group containing at least one nitrogen atom, a 5 to 14-membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group,

[0079] The above heterocycloalkenyl group may be substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0080] Here, the replacement of an arylene group with a halogen atom means that a hydrogen atom contained in the arylene group is replaced with a halogen atom, and the replacement of a heterocycloalkenyl group with the alkyl group or aryl group may also mean that a hydrogen atom contained in the heterocycloalkenyl group is replaced with the alkyl group or aryl group.

[0081] For example, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an arylene group having 6 to 8 carbon atoms, and the arylene group may or may not be substituted with a halogen atom. The halogen atom may be a chlorine atom.

[0082] For example, Ar 1 Inland Ar 3 are each independently a phenyl group, and the phenyl group may or may not be substituted with a halogen atom, and the halogen atom may be a chlorine atom. Ar 1 Inland Ar 3 A halogen atom may be substituted in any one of them, for example Ar 3 A chlorine atom can be substituted in .

[0083] For example, R 1It may be an alkoxy group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an octoxy group.

[0084] For example, R 2 and R 3 can be linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 10 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group.

[0085] For example, R 2 and R 3 can be linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 6 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group.

[0086] The above heterocycloalkenyl group may or may not be substituted with an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms, may or may not be substituted with an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 8 carbon atoms, may or may not be substituted with an alkyl group having 1 to 3 carbon atoms or a phenyl group, and may or may not be substituted with a methyl group or a phenyl group.

[0087] For example, R 2 and R 3 can be linked together with the nitrogen atom to which they are bonded to form a 5- to 9-membered heteroaryl group, tetrahydroquinolinyl group or indolinyl group containing at least one nitrogen atom.

[0088] For example, R 2 and R 3can be linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom.

[0089] In some embodiments, the compound having a structure represented by Chemical Formula 1 may include a compound having a structure represented by any one of Chemical Formulas 2 to 13 below.

[0090] [Chemical Formula 2]

[0091]

[0092] [Chemical Formula 3]

[0093]

[0094] [Chemical Formula 4]

[0095]

[0096] [Chemical Formula 5]

[0097]

[0098] [Chemical Formula 6]

[0099]

[0100] [Chemical Formula 7]

[0101]

[0102] [Chemical Formula 8]

[0103]

[0104] [Chemical Formula 9]

[0105]

[0106] [Chemical Formula 10]

[0107]

[0108] [Chemical Formula 11]

[0109]

[0110] [Chemical Formula 12]

[0111]

[0112] [Chemical Formula 13]

[0113]

[0114] In one embodiment, the thermal decomposition temperature of the dichroic dye may be about 245° C. or higher. The thermal decomposition temperature may refer to a temperature at which the weight of the dichroic dye decreases by 5% compared to the initial weight.

[0115] In some embodiments, the content of the dichroic dye may be included in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the polyolefin resin. Within this range, sufficient polarization characteristics can be exhibited without reducing transmittance when formed into a polarizing film.

[0116] For example, the composition for the polarizing film may contain the polyolefin resin and the dichroic dye in a solid form, such as a powder. The composition for the polarizing film may have a solid content of, for example, 90% by weight or more, and may not contain, for example, a solvent.

[0117] A polarizing film according to exemplary embodiments may include a polyolefin resin; and a dichroic dye comprising a compound having a structure represented by the above chemical formula 1. The description of the polyolefin resin and the dichroic dye comprising the compound having a structure represented by the above chemical formula 1 is as described above.

[0118] For example, the polarizing film may be a melt blend of a polyolefin resin and a dichroic dye. The melt blend may be a composition for a polarizing film comprising a polyolefin resin and a dichroic dye at a melting point (T) of the polyolefin resin. m ) can be obtained by melting and mixing at a temperature above.

[0119] In some embodiments, the dichroic ratio of the polarizing film may be 6 to 10. Here, the dichroic ratio is a value obtained by dividing the plane polarized light absorption in the direction perpendicular to the axis of the polymer by the polarized light absorption in the horizontal direction thereof, and can be obtained by the following mathematical equation 1.

[0120] [Mathematical Formula 1]

[0121] DR = Log(1 / T ⊥ ) / Log(1 / T ∥ )

[0122] In the above mathematical formula 1,

[0123] DR is the dichroic ratio of the polarizing film,

[0124] T ∥ is the transmittance of the polarizing film for light incident parallel to the transmission axis of the polarizing film,

[0125] T ⊥ may be the transmittance of a polarizing film for light incident perpendicular to the transmission axis of the polarizing film.

[0126] The above dichroic ratio can indicate the degree to which dichroic dyes are arranged in one direction in a polarizing film, and by having a dichroic ratio within the above range in the visible light wavelength region, it is possible to induce the orientation of the dichroic dye according to the orientation of the polymer chain, thereby improving the polarization characteristics.

[0127] In some embodiments, the polarizing film may have a polarization efficiency of 85% or greater in the wavelength range of 380 nm to 780 nm. For example, the polarizing film may have a polarization efficiency of 90% or greater, 95% to 100%, or 99.6% to 100%.

[0128] Within the above range, when applied to one side of a display device, it may not interfere with the emission of light from within the display device and may reproduce a clear image.

[0129] Here, the polarization efficiency can be obtained by the following mathematical equation 2.

[0130] [Equation 2]

[0131] PE (%) = [(T ∥ -T ⊥ ) / (T ∥ +T ⊥ )] 1 / 2 Ⅹ 100

[0132] In the above mathematical formula 2,

[0133] PE is the polarization efficiency,

[0134] T ∥ is the transmittance of the polarizing film for light incident parallel to the transmission axis of the polarizing film,

[0135] T ⊥ may be the transmittance of a polarizing film for light incident perpendicular to the transmission axis of the polarizing film.

[0136] For example, polarization efficiency and dichroic ratio can be obtained using transmittance in the wavelength range of the visible light region (e.g., 380 nm to 780 nm).

[0137] In some embodiments, the thickness of the polarizing film may be 100 μm or less, for example, 30 μm to 95 μm. Within this range, the thickness can be significantly reduced compared to a polarizing plate requiring a protective layer such as triacetyl cellulose (TAC), thereby enabling the implementation of a thin display device.

[0138] According to exemplary embodiments, the composition for polarizing films of the above-described embodiments may be melted, the melted mixture may be placed in a mold and pressed to produce a sheet, and the sheet may be uniaxially stretched to produce a polarizing film.

[0139] For example, the composition for the polarizing film can be melted at 300°C or lower, for example, from 150°C to 300°C, to obtain a mixture. The melted mixture can be placed in a mold and pressurized with a high-pressure press, or discharged onto a chill roll through a T-die to produce a sheet. The produced sheet can be stretched at an elongation of 300% to 1000% at a temperature of from 30°C to 200°C.

[0140] Here, the elongation refers to the ratio of the length of the sheet before elongation to the length after elongation, and can mean the extent to which the sheet is stretched after uniaxial elongation.

[0141] In some embodiments, the polarizing film may be applied to various display devices, and the display devices may be liquid crystal displays. For example, the polarizing film may be included in a flexible device.

[0142] FIG. 1 is a schematic cross-sectional view illustrating a flexible device including a polarizing film according to exemplary embodiments.

[0143] Referring to FIG. 1, the flexible device may include a flexible display panel (100); and a polarizing film (200) positioned on the flexible display panel (100).

[0144] For example, the flexible display panel (100) may be a substrate including a flexible material such as plastic or metal foil. The description of the polarizing film (200) is the same as described above, and since the polarization efficiency and dichroic ratio are high, the display performance can be maintained even if the flexible device is bent or curved.

[0145] For convenience, the polarizing film (200) is illustrated as being positioned on the flexible display panel (100), but is not limited thereto and may be positioned on the upper and lower portions of the flexible display panel (100), or may be positioned on only one of the upper and lower portions.

[0146] The polarizing film according to the above-described embodiments can be equally applied not only to flexible devices but also to all display devices in which polarizing films can be used, such as flexible organic light-emitting diode (OLED) devices, liquid crystal displays, organic light-emitting devices, electroluminescent displays, plasma displays, field emission displays, etc.

[0147] Hereinafter, experimental examples including specific examples and comparative examples are presented to help understand the present invention, but these are only illustrative of the present invention and do not limit the scope of the appended claims. It is obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical idea of ​​the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims.

[0148]

[0149] Synthesis of dichromatic dyes

[0150] Synthesis Example 1

[0151] (1) Preparation of 4-amino-4'-octyloxyazobenzene

[0152]

[0153] (4-amino-4'-octyloxyazobenzene)

[0154] 4-Nitroaniline (8 g) was dissolved in 500 mL of water and 38 mL of 12 N HCl, and then 4.4 g (63.74 mmol) of sodium nitrite (NaNO2) dissolved in 100 mL of water was slowly added dropwise to the reaction mixture. After the addition was complete, the reaction mixture was stirred for one hour while maintaining it at 0°C. Next, 18.54 g of sodium hydroxide (NaOH) and 63.74 mmol of phenol were dissolved in 100 mL of methanol and 50 mL of water, and then slowly added dropwise to the reaction mixture and stirred at 0°C for one hour. The reaction was terminated by neutralization with an aqueous sodium hydroxide (NaOH) solution, and the precipitated solid was filtered. The solid compound was washed several times and then dried to obtain a monoazo compound.

[0155] After dissolving 20 mmol of a monoazo compound in 200 mL of acetone, 22 mmol of 1-bromooctane and 100 mmol of potassium carbonate (K2CO3) were added. The mixture was then refluxed and stirred at 60°C for 24 hours, and then cooled to room temperature (25°C). The reaction mixture was concentrated, and the precipitated solid was washed several times and filtered to obtain 7 g (17.9 mmol) of an octyloxy monoazo compound.

[0156] 9.75 g (25.0 mmol) of purified octyloxy monoazo compound was dissolved in 300 mL of hot ethanol, and 12.0 g (50.0 mmol) of Na2S·9H2O dissolved in hot ethanol and water was added. The reaction mixture was stirred at 80°C for 5 hours and then cooled to room temperature. The precipitated crystals were filtered, washed several times, and dried to obtain 7 g of 4-amino-4'-octyloxyazobenzene.

[0157] (2) Preparation of chloro-amino-hexadecane oxydiazobenzene

[0158]

[0159] (chloro-amino-hexadecane oxydiazobenzene)

[0160] 2.4 g of 4-amino-4'-hexadecaneoxyazobenzene obtained in the above (1) was dissolved in 100 mL of acetic acid (AcOH), and 2.33 g (12.5 mmol) of 2-chloro-4-nitro-1-nitrosobenzene was added, followed by stirring at 40°C for 12 hours. The precipitated solid crystals were then filtered, washed with water several times, and dried to obtain 2.4 g of a disazo compound in a yield of 75%.

[0161] 2 g (3.12 mmol) of the synthesized disazo compound was dissolved in 50 mL of hot ethanol, and then 1.5 g (6.24 mmol) of Na2S·9H2O dissolved in hot ethanol and water was added. The reaction mixture was then stirred at 80°C for 5 hours and then cooled to room temperature. The precipitated crystals were filtered, washed several times, and dried to obtain chloro-amino-hexadecanoxydiazobenzene in a yield of 63%.

[0162] (3) Preparation of a compound having a structure represented by chemical formula 2

[0163] [Chemical Formula 2]

[0164]

[0165] 1 mmol of chloro-amino-hexadecane oxydiazobenzene obtained in the above (2) was dissolved in 20 mL of dimethylformamide (DMF) and acetic acid (AcOH), and 0.5 mL of 12 N HCl was added thereto and maintained at 0°C. Next, 72 mg (1.04 mmol) of sodium nitrite (NaNO2) was dissolved in 1 mL of water and slowly added dropwise to the reaction mixture, and after the addition was completed, the reaction mixture was stirred for one hour while maintaining it at 0°C. Next, 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole (1 mmol), an unsaturated cyclic aminothiophene, was dissolved in 25 mL of methanol and 2 mL of dimethylformamide (DMF), and slowly added dropwise to the reaction mixture, and the mixture was stirred at 0°C for about one hour. Subsequently, the reaction was terminated by neutralizing with an aqueous sodium hydroxide (NaOH) solution, and the precipitated solid was filtered. The mixture was purified by silica gel column chromatography (n-hexane:EtOAc=3:1) to obtain 600 mg (0.76 mmol) of a compound having a structure represented by the chemical formula 2.

[0166] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, was obtained by reacting 2-bromothiophene with 2,5-dihydro-1H-pyrrole in the presence of a transition metal catalyst.

[0167] (1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole)

[0168]

[0169] Synthesis Example 2

[0170] (1) Preparation of a compound having a structure represented by chemical formula 3

[0171] [Chemical Formula 3]

[0172]

[0173] Except for using 1-(thiophen-2-yl)-1H-imidazole instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 3.

[0174] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-1H-imidazole, was obtained by reacting 2-bromothiophene with 1H-imidazole in the presence of a transition metal catalyst.

[0175] (1-(thiophen-2-yl)-1H-imidazole)

[0176]

[0177] Synthesis Example 3

[0178] (1) Preparation of a compound having a structure represented by chemical formula 4

[0179] [Chemical Formula 4]

[0180]

[0181] Except for using 1-(thiophen-2-yl)-1H-pyrrole instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 4.

[0182] Here, the unsaturated cyclic aminothiophene, 1-(thiophene-2-yl)-1H-pyrrole, was obtained by reacting 2-bromothiophene with 1H-pyrrole in the presence of a transition metal catalyst.

[0183] (1-(thiophen-2-yl)-1H-pyrrole)

[0184]

[0185] Synthesis Example 4

[0186] (1) Preparation of a compound having a structure represented by chemical formula 5

[0187] [Chemical Formula 5]

[0188]

[0189] A compound having a structure represented by chemical formula 5 was prepared in the same manner as in Synthesis Example 1, except that 1-(thiophen-2-yl)-1H-indole was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthesis Example 1.

[0190] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-1H-indole, was obtained by reacting 2-bromothiophene with 1H-indole in the presence of a transition metal catalyst.

[0191] (1-(thiophen-2-yl)-1H-indole)

[0192]

[0193] Synthesis Example 5

[0194] (1) Preparation of a compound having a structure represented by chemical formula 6

[0195] [Chemical Formula 6]

[0196]

[0197] Except that 1-(thiophen-2-yl)-1H-benzo[d]imidazole was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 6.

[0198] Here, the unsaturated cyclic aminothiophene, 1-(thiophene-2-yl)-1H-benzo[d]imidazole, was obtained by reacting 2-bromothiophene with 1H-benzo[d]imidazole in the presence of a transition metal catalyst.

[0199] (1-(thiophen-2-yl)-1H-benzo[d]imidazole)

[0200]

[0201] Synthesis Example 6

[0202] (1) Preparation of a compound having a structure represented by chemical formula 7

[0203] [Chemical Formula 7]

[0204]

[0205] Except that 1-(thiophen-2-yl)-1,2,3,4-tetrahydropyridine was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by chemical formula 7.

[0206] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-1,2,3,4-tetrahydropyridine, was obtained by reacting 2-bromothiophene with 1,2,3,4-tetrahydropyridine in the presence of a transition metal catalyst.

[0207] (1-(thiophen-2-yl)-1,2,3,4-tetrahydropyridine)

[0208]

[0209] Synthesis Example 7

[0210] (1) Preparation of a compound having a structure represented by chemical formula 8

[0211] [Chemical Formula 8]

[0212]

[0213] Except that 1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 8.

[0214] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine, was obtained by reacting 2-bromothiophene with 1,2,3,6-tetrahydropyridine in the presence of a transition metal catalyst.

[0215] (1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine)

[0216]

[0217] Synthesis Example 8

[0218] (1) Preparation of a compound having a structure represented by chemical formula 9

[0219] [Chemical Formula 9]

[0220]

[0221] Except that 2-methyl-1-(thiophen-2-yl)-4,5-dihydro-1H-imidazole was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by chemical formula 9.

[0222] Here, the unsaturated cyclic aminothiophene, 2-methyl-1-(thiophen-2-yl)-4,5-dihydro-1H-imidazole, was obtained by reacting 2-bromothiophene with 2-methyl-4,5-dihydro-1H-imidazole in the presence of a transition metal catalyst.

[0223] (2-methyl-1-(thiophen-2-yl)-4,5-dihydro-1H-imidazole)

[0224]

[0225] Synthesis Example 9

[0226] (1) Preparation of a compound having a structure represented by chemical formula 10

[0227] [Chemical Formula 10]

[0228]

[0229] Except that 2-(thiophen-2-yl)-1,2,3,4-tetrahydroisoquinoline was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 10.

[0230] Here, the unsaturated cyclic aminothiophene, 2-(thiophen-2-yl)-1,2,3,4-tetrahydroisoquinoline, was obtained by reacting 2-bromothiophene with 1,2,3,4-tetrahydroisoquinoline in the presence of a transition metal catalyst.

[0231] (2-(thiophen-2-yl)-1,2,3,4-tetrahydroisoquinoline)

[0232]

[0233] Synthesis Example 10

[0234] (1) Preparation of a compound having a structure represented by chemical formula 11

[0235] [Chemical Formula 11]

[0236]

[0237] Except that 4-phenyl-1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 11.

[0238] Here, the unsaturated cyclic aminothiophene, 4-phenyl-1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine, was obtained by reacting 2-bromothiophene with 4-phenyl-1,2,3,6-tetrahydropyridine in the presence of a transition metal catalyst.

[0239] (4-phenyl-1-(thiophen-2-yl)-1,2,3,6-tetrahydropyridine)

[0240]

[0241] Synthesis Example 11

[0242] (1) Preparation of a compound having a structure represented by chemical formula 12

[0243] [Chemical Formula 12]

[0244]

[0245] Except that 1-(thiophen-2-yl)-1,2,3,4-tetrahydroquinoline was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 12.

[0246] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)-1,2,3,4-tetrahydroquinoline, was obtained by reacting 2-bromothiophene with 1,2,3,4-tetrahydroquinoline in the presence of a transition metal catalyst.

[0247] (1-(thiophen-2-yl)-1,2,3,4-tetrahydroquinoline)

[0248]

[0249] Synthesis Example 12

[0250] (1) Preparation of a compound having a structure represented by chemical formula 13

[0251] [Chemical Formula 13]

[0252]

[0253] Except that 1-(thiophen-2-yl)indoline was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, which is an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 13.

[0254] Here, the unsaturated cyclic aminothiophene, 1-(thiophen-2-yl)indoline, was obtained by reacting 2-bromothiophene with indoline in the presence of a transition metal catalyst.

[0255] (1-(thiophen-2-yl)indoline)

[0256]

[0257] Comparative synthesis example 1

[0258] (1) Preparation of a compound having a structure represented by chemical formula 14

[0259] [Chemical Formula 14]

[0260]

[0261] Except that 1-(thiophen-2-yl)pyrrolidine, a saturated cyclic aminothiophene, was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, an unsaturated cyclic aminothiophene, in (3) of Synthetic Example 1, the same procedure as in Synthetic Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 14.

[0262] Here, the saturated cyclic aminothiophene, 1-(thiophen-2-yl)pyrrolidine, was obtained by reacting 2-bromothiophene with pyrrolidine in the presence of a transition metal catalyst.

[0263] (1-(thiophen-2-yl)pyrrolidine)

[0264]

[0265] Comparative synthesis example 2

[0266] (1) Preparation of a compound having a structure represented by chemical formula 15

[0267] [Chemical Formula 15]

[0268]

[0269] In (2) of Synthesis Example 1, 4-nitro-1-nitrosobenzene was used instead of 2-chloro-4-nitro-1-nitrosobenzene, and in (3) of Synthesis Example 1, 1-(thiophen-2-yl)pyrrolidine, a saturated cyclic aminothiophene, was used instead of 1-(thiophen-2-yl)-2,5-dihydro-1H-pyrrole, an unsaturated cyclic aminothiophene, was used instead of 1-(thiophen-2-yl)pyrrolidine, a saturated cyclic aminothiophene, was used, and the same procedure as in Synthesis Example 1 was carried out to prepare a compound having a structure represented by Chemical Formula 14.

[0270] Here, the saturated cyclic aminothiophene, 1-(thiophen-2-yl)pyrrolidine, was obtained by reacting 2-bromothiophene with pyrrolidine in the presence of a transition metal catalyst.

[0271] (1-(thiophen-2-yl)pyrrolidine)

[0272]

[0273] Manufacturing of polarizing films

[0274] Example 1

[0275] A dichroic dye comprising a polyolefin resin (solubility parameter: 16.6) containing polypropylene (PP) and polypropylene-polyethylene copolymer (PP-PE) in a 5:5 (w / w) ratio and a compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1 was prepared, and 0.5 parts by weight of the dichroic dye was mixed with 100 parts by weight of the polyolefin resin to prepare a composition for a polarizing film.

[0276] The composition for the above polarizing film was melt-mixed at 250°C using a Micro-compounder (manufactured by DSM). The melt-mixed mixture was placed in a sheet-shaped mold and pressed using a high-temperature, high-pressure press to produce a sheet. The sheet was uniaxially stretched at 1000% magnification (using a tensile tester manufactured by Instron) at a temperature of 125°C to produce a polarizing film.

[0277]

[0278] Example 2

[0279] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 3 obtained in Synthesis Example 2 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0280]

[0281] Example 3

[0282] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 4 obtained in Synthesis Example 3 was used instead of a compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0283]

[0284] Example 4

[0285] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 5 obtained in Synthesis Example 4 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0286]

[0287] Example 5

[0288] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 6 obtained in Synthesis Example 5 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0289]

[0290] Example 6

[0291] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 7 obtained in Synthesis Example 6 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0292]

[0293] Example 7

[0294] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 8 obtained in Synthesis Example 7 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0295]

[0296] Example 8

[0297] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 9 obtained in Synthesis Example 8 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0298]

[0299] Example 9

[0300] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye including a compound having a structure represented by Chemical Formula 10 obtained in Synthesis Example 9 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0301]

[0302] Example 10

[0303] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye comprising a compound having a structure represented by Chemical Formula 11 obtained in Synthesis Example 10 was used instead of a compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0304]

[0305] Example 11

[0306] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye comprising a compound having a structure represented by Chemical Formula 12 obtained in Synthesis Example 11 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0307]

[0308] Example 12

[0309] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye comprising a compound having a structure represented by Chemical Formula 13 obtained in Synthesis Example 12 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0310]

[0311] Comparative Example 1

[0312] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye comprising a compound having a structure represented by Chemical Formula 14 obtained in Comparative Synthesis Example 1 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0313]

[0314] Comparative Example 2

[0315] A polarizing film was manufactured in the same manner as in Example 1, except that a dichroic dye comprising a compound having a structure represented by Chemical Formula 15 obtained in Comparative Synthesis Example 2 was used instead of the compound having a structure represented by Chemical Formula 2 obtained in Synthesis Example 1.

[0316]

[0317] Experimental example

[0318] Polarization characteristics (polarization efficiency and dichroic ratio) of the polarizing films of the examples and comparative examples were evaluated as follows. Polarization efficiency and dichroic ratio were obtained using transmittance in the wavelength range of the visible light region (e.g., 380 nm to 780 nm).

[0319] Transmittance is the transmittance (T) of a polarizing film for light incident parallel to the transmission axis of the polarizing film. ∥ ) and the transmittance (T) of the polarizing film for light incident perpendicular to the transmission axis of the polarizing film. ⊥ ) were measured respectively, and measured using a UV-VIS spectrophotometer (JASCO, V-7100).

[0320] The dichroic ratio (DR) was calculated according to the following mathematical equation 1.

[0321] [Mathematical Formula 1]

[0322] DR = Log(1 / T ⊥ ) / Log(1 / T ∥ )

[0323] In the above mathematical expression 1, DR is the dichroic ratio of the polarizing film, and T ∥ is the transmittance of the polarizing film for light incident parallel to the transmission axis of the polarizing film, and T ⊥ is the transmittance of a polarizing film for light incident perpendicular to the transmission axis of the polarizing film.

[0324] The polarization efficiency was calculated according to the following mathematical equation 2.

[0325] [Equation 2]

[0326] PE (%) = [(T ∥ -T ⊥ ) / (T ∥ +T ⊥ )] 1 / 2 Ⅹ 100

[0327] In the above mathematical expression 2, PE is the polarization efficiency, and T ∥ is the transmittance of the polarizing film for light incident parallel to the transmission axis of the polarizing film, and T ⊥ is the transmittance of a polarizing film for light incident perpendicular to the transmission axis of the polarizing film.

[0328] The calculated dichroic ratio and polarization efficiency are listed in Table 1 below.

[0329] Polarization Efficiency (%) Dichroic Ratio Example 199.6 5.6 Example 299.7 5.8 Example 399.6 5.9 Example 499.8 6.1 Example 599.8 6.0 Example 699.8 6.2 Example 799.8 5.7 Example 899.9 6.2 Example 999.6 5.6 Example 1099.7 5.7 Example 1199.9 6.0 Example 1299.86.1 Comparative Example 199.3 5.4 Comparative Example 282.3 2.1

[0330] Referring to Table 1, the polarizing films of Examples 1 to 12 manufactured using a dichroic dye containing a compound containing a thiophene structure linked to an unsaturated cyclic amine had improved polarization efficiency and dichroic ratio.

[0331] However, compared to the polarizing films of Examples 1 to 12, the polarizing films of Comparative Examples 1 and 2, which were manufactured using a dichroic dye containing a compound containing a thiophene structure linked to a saturated cyclic amine and not containing the compound, had lower polarization efficiency and dichroic ratio.

[0332] For example, the compounds containing a thiophene structure linked to an unsaturated cyclic amine of Examples 1 to 12 include a π bond in the unsaturated cyclic amine, or the unsaturated cyclic amine is conjugated with the thiophene ring to form sp 2 It can form resonant hybrid structures.

[0333] On the other hand, in the case of Comparative Examples 1 and 2, only the unshared electron pair in the nitrogen atom of the saturated cyclic amine is delocalized to the thiophene ring, so the degree of conjugation is low.

[0334] Accordingly, since the compounds included in the dichroic dyes of Examples 1 to 12 have higher linearity or planarity of molecular structure, when the polyolefin resin is aligned by stretching, the dichroic dyes can also be sufficiently aligned in the stretching direction, and since the orientation of the dichroic dyes of Examples 1 to 12 is higher, the polarization characteristics of the polarizing films of Examples 1 to 12 can be further improved.

Claims

1. Polyolefin resin; and A composition for a polarizing film, comprising a dichroic dye comprising a compound having a structure represented by the following chemical formula 1: [Chemical Formula 1] (In chemical formula 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 20 carbon atoms, and the arylene group is optionally substituted with a halogen atom, R 1 is an alkoxy group having 1 to 24 carbon atoms, R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 14 membered heteroaryl group containing at least one nitrogen atom, a 5 to 14 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group, The above heterocycloalkenyl group is optionally substituted with an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

2. In claim 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 12 carbon atoms, and the arylene group is optionally substituted with a halogen atom, R 1 is an alkoxy group having 1 to 12 carbon atoms, R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 10 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group, A composition for a polarizing film, wherein the heterocycloalkenyl group is unsubstituted or substituted with an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms.

3. In claim 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 10 carbon atoms, wherein the arylene group is substituted or not substituted with a chlorine atom, R 1 is an alkoxy group having 1 to 8 carbon atoms, R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 9 membered heteroaryl group containing at least one nitrogen atom, a 5 to 6 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group, A composition for a polarizing film, wherein the heterocycloalkenyl group is optionally substituted with an alkyl group or a phenyl group having 1 to 3 carbon atoms.

4. In claim 1, a composition for a polarizing film, wherein the compound having a structure represented by the chemical formula 1 comprises a compound having a structure represented by any one of the following chemical formulas 2 to 13: [Chemical formula 2] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5] [Chemical formula 6] [Chemical formula 7] [Chemical formula 8] [Chemical formula 9] [Chemical Formula 10] [Chemical Formula 11] [Chemical Formula 12] [Chemical Formula 13] 5. A composition for a polarizing film according to claim 1, wherein the polyolefin resin comprises at least one selected from the group consisting of polyethylene, polypropylene, and a polyethylene-polypropylene copolymer.

6. A composition for a polarizing film according to claim 5, wherein the polyolefin resin comprises polypropylene and a polyethylene-polypropylene copolymer in a weight ratio of 1:9 to 9:

1.

7. A composition for a polarizing film according to claim 1, wherein the content of the dichroic dye is 0.05 parts by weight to 2 parts by weight based on 100 parts by weight of the polyolefin resin.

8. Polyolefin resin; and A polarizing film comprising a dichroic dye comprising a compound having a structure represented by the following chemical formula 1: [Chemical Formula 1] (In chemical formula 1, Ar 1 Inland Ar 3 are each independently an arylene group having 6 to 20 carbon atoms, and the arylene group is optionally substituted with a halogen atom, R 1 is an alkoxy group having 1 to 24 carbon atoms, R 2 and R 3 are linked together with the nitrogen atom to which they are bonded to form a 5 to 14 membered heteroaryl group containing at least one nitrogen atom, a 5 to 14 membered heterocycloalkenyl group containing at least one nitrogen atom, a tetrahydroquinolinyl group, a tetrahydroisoquinolinyl group or an indolinyl group, The above heterocycloalkenyl group is optionally substituted with an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

9. A polarizing film having a dichroic ratio of 6 to 10 according to claim 8.

10. A polarizing film according to claim 8, having a polarization efficiency of 85% or more in a wavelength range of 380 nm to 780 nm.

11. A step of melting the composition for a polarizing film of claim 1; A step of putting the above molten mixture into a mold and pressurizing it to produce a sheet; and A method for manufacturing a polarizing film, comprising the step of uniaxially stretching the above sheet.

12. A method for manufacturing a polarizing film according to claim 11, wherein the step of uniaxially stretching the sheet includes stretching the sheet at an elongation of 300% to 1000%.

13. Flexible display panel; and A flexible device comprising a polarizing film according to claim 8 positioned on the display panel.

Images