Use of an ink in an electrowetting display device

Abstract

The application discloses application of an ink in an electrowetting display device, and the ink comprises an organic dye and a non-polar solvent; a structural formula of the organic dye is as follows: wherein R1 is selected from substituted or unsubstituted C 1～20 alkyl, C 1～20 alkyl ether; R2, R3, R4 and R5 are independently selected from substituted or unsubstituted C 1～20 alkoxy. The application obtains the organic dye with blue and cyan by combination of R1-R5 substituents. The main ring and the branch are matched with each other, so that the light stability of the organic dye is improved. The ink has pure color and high molar absorption coefficient, and the organic dye has high solubility in the non-polar organic solvent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ink, in particular to application of ink in electrofluide display device. BACKGROUND

[0002] Electrofluide display (EFD) is a display device based on electrofluide display principle, which is developed by Philips Company in 2003. It includes dye, polar liquid and hydrophobic layer. The principle is that the surface property of the hydrophobic layer is controlled by voltage, and then the contact angle of the ink layer on the hydrophobic layer is changed, so that the display image effect is obtained. Specifically, when no voltage is applied, the ink is evenly wetted on the hydrophobic layer to form a colored pixel point; when voltage is applied, the interfacial tension between the dye-polar liquid-hydrophobic layer changes, and the ink is compressed to form a transparent or substrate color pixel point.

[0003] The electrofluide display ink is a special material for displaying color of electrofluide display. The solubility of dye in non-polar solvent, color saturation and color strength in the electrofluide display ink are closely related to the color effect of the electrofluide display. In the electrofluide display, the commonly used organic dyes include anthraquinone organic dyes and azo organic dyes. Most of the anthraquinone organic dyes have low polarity and excellent light resistance, so they are concerned by researchers, but the color strength of the anthraquinone organic dyes is low. The azo organic dyes make up for the shortcomings of the anthraquinone organic dyes, and have the advantage of high color strength. However, most of the azo organic dyes have poor light stability, which is difficult to meet the application requirements of the electrofluide display device in outdoor.

[0004] Therefore, it is necessary to provide a new ink applied in the electrofluide display technology, so that it has high light stability, high non-polar solubility and high color strength. SUMMARY

[0005] The present application aims to at least solve one of the technical problems in the prior art. To this end, the present application provides application of ink in electrofluide display device, which can effectively improve the light stability, non-polar solubility and color strength.

[0006] According to the first aspect of the present application, an application of ink in electrofluide display device is provided, and the ink includes organic dye and non-polar solvent; the structural formula of the organic dye is as follows:

[0007]

[0008] In the formula, R1 is selected from substituted or unsubstituted C 1～20 alkyl, C 1～20 alkyl ether group.

[0009] R2, R3, R4, R5 are independently selected from substituted or unsubstituted C 1～20 alkoxy.

[0010] The application of the ink according to the embodiments of the present application in the electrowetting display device has at least the following beneficial effects:

[0011] The organic dye with blue and cyan phases is obtained by the combination of R1-R5 substituents.

[0012] On the other hand, the ink of the present application has a pure color and a high molar absorption coefficient, and the organic dye has a high solubility in a non-polar organic solvent.

[0013] According to some embodiments of the present application, R1 is selected from substituted or unsubstituted C 6～20 alkyl.

[0014] According to some embodiments of the present application, R1 is selected from one of n-hexyl, n-heptane, n-octane, iso-octane, 2-ethylhexyl, nonyl, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, n-icosane, 2-nonyldecyl, 2-pentylhexyl, 2-heptyloctyl or 2-octyldodecyl.

[0015] According to some embodiments of the present application, R1 is selected from at least one of 2-ethylhexyl, 2-nonyldecyl, 2-pentylhexyl, 2-heptyloctyl or 2-octyldodecyl.

[0016] When R1 is selected from at least one of 2-ethylhexyl, 2-nonyldecyl, 2-pentylhexyl, 2-heptyloctyl or 2-octyldodecyl, the organic dye has a high solubility in a non-polar organic solvent.

[0017] According to some embodiments of the present application, R2, R3, R4, R5 are independently selected from at least one of hydrogen, n-hexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecyloxy, n-icosyloxy, 2-nonyldecyloxy, 2-pentylhexyloxy, 2-heptyloctyloxy, 2-octyldodecyloxy, 3-octyl-1-tridecyloxy, 4-hexyl-1-dodecyloxy.

[0018] According to some embodiments of the present application, R2, R3, R4, R5 are independently selected from one of 2-ethylhexyloxy, 3-octyl-1-tridecyloxy, 4-hexyl-1-dodecyloxy and 2-octyl-1-dodecyloxy.

[0019] When R2, R3, R4, R5 are independently selected from one of 2-ethylhexyloxy, 3-octyl-1-tridecyloxy, 4-hexyl-1-dodecyloxy and 2-octyl-1-dodecyloxy, the organic dye has excellent solubility in non-polar solvents.

[0020] According to some embodiments of the present application, the organic dye is selected from at least one of the following structural formulae:

[0021]

[0022]

[0023] According to some embodiments of the present application, the ink comprises the following components by weight parts: organic dye 1-30 parts; non-polar solvent 5-100 parts.

[0024] According to some embodiments of the present application, the ink comprises the following components by weight parts: organic dye 1-30 parts; non-polar solvent 70-99 parts.

[0025] According to some embodiments of the present application, the non-polar solvent is selected from at least one of n-decane, n-dodecane, n-tetradecane, n-hexadecane, decane or fluorine-containing alkane.

[0026] In the present application, "substituted or unsubstituted" means that the group can or can not be further substituted by one or more groups selected from alkyl, alkenyl, alkynyl, aryl, halogen, haloalkyl, haloalkenyl, haloalkynyl, haloaryl, hydroxy, alkoxy, alkenyloxy, aryloxy, benzyloxy, haloalkoxy, haloalkenyloxy, haloaryloxy, nitro, nitroalkyl, nitroalkenyl, nitroalkynyl, nitroaryl, nitroheterocyclyl, amino, alkylamino, dialkylamino, alkenylamino, alkynylamino, arylamino, diarylamino, phenylamino, diphenylamino, benzylamino, dibenzylamino, hydrazino, acyl, acylamino, diacylamino, acyloxy, heterocyclyl, heterocyclyloxy, heterocyclylamino, haloheterocyclyl, carboxyl ester, carboxyl.

[0027] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0029] Figure 1 is a UV-Vis absorption spectrum of the organic dye prepared in Example 1;

[0030] Figure 2 is a UV-Vis absorption spectrum of the organic dye prepared in Example 2. DETAILED DESCRIPTION

[0031] The following are specific examples of the present application, and the technical solutions of the present application are further described in conjunction with the examples, but the present application is not limited to these examples.

[0032] The reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field unless otherwise specified.

[0033] Example 1

[0034] Example 1 provides an organic dye, which is prepared as follows:

[0035] Synthesis of N-(2-octyldodecyl)-4,5-dibromonaphthalimide:

[0036]

[0037] Reaction a: 13 grams, 0.0465 mol of naphthalic anhydride was dispersed in 300 mL of water, KOH (0.2321 mol, 13 grams, 5 eq) was added, and the temperature was raised to 85°C; bromine (2.5 eq, 21 g, 0.1167 mol) was slowly dropped into a constant pressure funnel, and the reaction was continued for 1 hour after dropping was completed; the temperature was lowered to room temperature, 100 mL of 2N concentrated dilute hydrochloric acid was added, and after stirring for half an hour, the filter cake was washed with water twice, the solid was dispersed in ethanol and filtered again, and after drying, 16 grams of intermediate 1 was obtained with a yield of 96.6%.

[0038] Reaction b: 0.01 mol, 3.56 g of intermediate 1 was weighed, dispersed in 100 ml of THF solvent with stirring, 0.01 mol, 1.98 g of 2-octyldodecylamine was added, 1 mL of propionic acid was added, argon protection was performed, heating was performed to 60°C, and the reaction was continued for 8 hours; after the reaction was completed, the temperature was lowered to room temperature, water was added for dilution, the product was precipitated, and filtration was performed; the filter residue was washed with ethyl acetate, and the filtrate was extracted 3 times; after concentration, column chromatography was performed, the eluent was dichloromethane: petroleum ether = 1:100, and the yield was 55%.

[0039] 1H NMR (600 MHz, CDC13, 27°C, TMS): 8.364-8.378 (d, 2H, CH aromat), 8.172-8.185 (d, 2H, CH aromat), 4.059-4.071 (d, 2H, NCH2), 1.947-1.967 (m, 1H), 1.213-1.320 (m, 32H, 16xCH2), 0.838-0.878 (m, 6H).

[0040] Preparation of the compound of formula la:

[0041]

[0042] Reaction C: Weighed intermediate 2 (649.5 g / mol, 2.1 mmol, 1.364 g), 1,8- naphthalene diboronic acid (380 g / mol, 1 mmol, 0.38 g); Pd2(dba)3 (912.5 g / mol, 0.2 mmol, 0.182 g), Pcy3: (280.43 g / mol; 0.8 mmol, 0.224 g), potassium carbonate 10 eq, 10 mmol, 50 mL of super dry o-xylene, argon protection, 145°C for 24 hours. After the reaction, 100 mL of petroleum ether was added to dilute it, and after standing for 1 hour, it was filtered, and the filter residue was washed with petroleum ether twice, and after drying, 0.33 g of blue product was obtained, yield: 30%.

[0043] 1 H NMR (600 MHz, CDC13, 27°C, TMS): 8.364-8.378 (d, 2H, CH aromat), 8.172-8.185 (d, 2H, CH aromat), 4.059-4.071 (d, 2H, NCH2), 1.947-1.967 (m, 1H), 1.213-1.320 (m, 32H, 16xCH2), 0.838-0.878 (m, 6H).

[0044] Figure 1 is the UV-Vis absorption spectrum of the compound of formula la of Example 1, whose data are as follows: Uv(vis) n-hexane: λmax= 595 nm, 645 nm.

[0045] Example 2

[0046] Example 2 provides an organic dye, whose reaction equation is as follows, and its preparation method is as follows,

[0047]

[0048] Reaction d: The compound of formula la (1075.55 g / mol, 1 mmol, 1.075 g) was weighed and dissolved in 1.2-dichloroethane, 20 mmol of bromine (3.6 g) and 8 mmol of anhydrous potassium carbonate (1.2 g) were added. The reaction was heated to 60°C and left for 36 hours. Once the reaction was finished, 100% of a 10% aqueous solution of sodium dithionite was added and stirred for 10 min, it was transferred to a separation funnel, washed twice with water and concentrated to dryness to obtain the intermediate 3 with a yield of 90%.

[0049] The NMR data of the intermediate 3 are as follows:

[0050] 1 NMR (600 MHz, CDC13, 27°C, TMS): 8.944 (s, 4H, CH Z ), 8.634 (s, 4H, CH terrylene ), 8.165 (s, 4H, CH terrylene ), 7.399-7.413 (d, 8H, J = 7.79 Hz 1 ), 7.061-7.075 (d, 8H, J = 8.1 Hz Z ), 4.144-4.156 (d, 4H, NCH2); 1.958-1.976 (m, 2H,); 1.239-1.283 (m, 64H, 32 x CH2) δ = 0.843-0.895 (m, 12H).

[0051] Reaction e: The product of reaction d, intermediate 3, was dissolved in 20 mL of toluene, 20 mL of DMF, p-t-octylphenol (206.32 g / mol, 0.01 mol, 2.06 g), cesium carbonate (325.82 g / mol, 0.006 mol, 1.955 g) were added and heated to 120°C for 12 hours under argon. Once the reaction was finished, it was cooled to 20°C, 30 mL of water were added to the reaction, it was stirred and left to separate, the aqueous layer was separated and the reaction was added to 100 mL of ethanol and frozen to 0°C below, left for 1 hour and filtered to obtain a blue solid which was recrystallized once with ethanol. The product was chromatographed over a column with eluent n-hexane: dichloromethane = 50:1 to obtain 1.36 g of the blue product of formula lb with a yield of 80%.

[0052] The NMR data of the compound of formula lb are as follows:

[0053] 1 NMR (600 MHz, CDC13, 27°C, TMS): 8.944 (s, 4H, CH Z ), 8.634 (s, 4H, CH terrylene ), 8.165 (s, 4H, CH terrylene ), 7.399-7.413 (d, 8H, J = 7.79 Hz Z ), 7.061-7.075 (d, 8H, J = 8.1 Hz Z), 3.975-3.987 (d, 4H, NCH2); 1.886-1.905 (m, 2H,); 1.754 (s, 8H, J = 8H Z ), 1.416 (s, 24H, J = 24H Z ), 1.205-1.261 (m, 64H, 32 x CH2, J = 64H Z ); 0.812-0.854 (m, 16H, J = 16H Z ); 0.792 (s, 32H, J = 31.69H Z ) ppm;

[0054] 13 C-NMR (600 MH Z , CDCI3, 27°C, TMS): 14.1, 22.6, 26.5, 29,3, 29.6, 30.0, 31.4, 31.7, 32.4, 36.6, 38.4, 44.6, 57.2, 118.9, 121.6, 121.7, 122.7, 128.6, 129.0, 130.6, 146.8, 153.0, 154.7, 163.3 ppm.

[0055] Figure 2 is the UV-Vis absorption spectrum of the compound of Example lb, and the data is as follows: Uv (vis) n-hexane: λmax (ε) = 610 nm, 650 nm.

[0056] Example 3

[0057] Example 3 provides an organic dye, the structure of which is as follows, and the preparation method thereof is the same as that of Example 2.

[0058]

[0059] Example 4

[0060] Example 4 provides an organic dye, the structure of which is as follows, and the preparation method thereof is the same as that of Example 2.

[0061]

[0062] Example 5

[0063] 0.1 g of the organic dye of Examples 1-4, respectively, is weighed and dissolved in 10 mL of a non-polar solvent to obtain an ink, respectively.

[0064] The color, the maximum absorption wavelength (λmax), the solubility C at 20°C, the molar absorption coefficient ε and ε-C of the prepared ink materials are observed and shown in Table 1.

[0065] Table 1 Properties of inks

[0066]

[0067] From Table 1, it can be seen that the electro wetting ink material of the present application has very high solubility and molar extinction coefficient, and the value of ε·C is also very high, most of the inks can reach 1 x 10 3 The above has bright color and high saturation.

[0068] The ink of Example 1 was filled into an electro wetting display device, and its light stability was tested, and the results are shown in Table 2.

[0069] Before aging Aging 20h Aging 40h Aging 60h Aging 80h Aging 100h L 89.1 90.0 88.0 90.1 89.0 88.3 a -71.9 -72.3 -72.7 -72.5 -72.9 -73.3 b -53.4 -52.0 -52.4 -52.8 -52.4 -52.1 △E -(standard) 1.69 1.61 1.80 1.36 2.0

[0070] Aging conditions: xenon lamp, light intensity 0.55 W / m 2 (340 nm), T = 45℃;

[0071] From Table 2, it can be seen that the color difference value of the dye in Example 1 is only 2.0 after 100 h of high-intensity light aging, indicating that the dye disclosed in the present application has very high stability in the electro wetting system.

[0072] The inks of Examples 1-4 were filled into an electro wetting display device, and its electrical response performance was tested, and the results are shown in Table 3.

[0073] Table 3 Electrical response performance of electro wetting display device using ink

[0074]

[0075] From Table 3, it can be seen that the electro wetting display device filled with the ink of the present application has low switching voltage, fast response time, and no backflow phenomenon under constant voltage, and the ink prepared from the dye described in the present application is very suitable for electro wetting display.

[0076] The above has been described in detail in combination with the embodiments of the present application, but the present application is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the purpose of the present application.

Claims

1. The application of an ink in an electrowetting display device, characterized in that, The ink comprises organic dyes and non-polar solvents; the structural formula of the organic dyes is as follows: Formula I; Wherein, R1 is selected from one of n-hexyl, n-heptyl, n-octyl, isooctyl, 2-ethylhexyl, nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecanyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecanyl, n-eicosyl, 2-nonyldecyl, 2-pentylhexyl, 2-heptyloctyl, or 2-octyldodecyl; R2, R3, R4, and R5 are each independently selected from at least one of hydrogen, n-hexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecanyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecanyloxy, n-eicosyloxy, 2-nonyldecyloxy, 2-pentylhexyloxy, 2-heptyloctyloxy, 2-octyl-1-dodecyloxy, 3-octyl-1-tridecyloxy, and 4-hexyl-1-dodecyloxy.

2. The application of the ink according to claim 1 in an electrowetting display device, characterized in that, R1 is selected from at least one of 2-ethylhexyl, 2-nonyldecyl, 2-pentylhexyl, 2-heptyloctyl, or 2-octyldodecyl.

3. The application of the ink according to claim 1 in an electrowetting display device, characterized in that, R2, R3, R4, and R5 are each independently selected from one of 2-ethylhexyloxy, 3-octyl-1-tetrateoxy, 4-hexyl-1-dodecanooxy, and 2-octyl-1-dodecanooxy.

4. The application of an ink in an electrowetting display device, characterized in that, The ink comprises organic dyes and nonpolar solvents; the organic dyes are selected from at least one of the following structural formulas: Formula Ia; Formula Ib; Formula Ic.

5. The application of the ink according to claim 1 in an electrowetting display device, characterized in that, The ink comprises the following components by weight: 1-30 parts organic dye; 5-100 parts non-polar solvent.

6. The application of the ink according to claim 5 in an electrowetting display device, characterized in that, The ink comprises the following components by weight: 1-30 parts organic dye; 70-99 parts non-polar solvent.

7. The application of the ink according to claim 5 in an electrowetting display device, characterized in that, The nonpolar solvent is selected from at least one of n-decane, n-dodecane, n-tetradecane, n-hexadecane, or fluorinated alkanes.

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