Fiber for flexible display cellulose liquid crystal device and preparation method thereof

Abstract

The invention discloses a fiber for a flexible display cellulose liquid crystal device, and relates to the technical field of fibers, the fiber comprises combed cotton, composite polyol and a modifier; wherein the modifier comprises iron tetracarboxyl phthalocyanine and aluminum tetracarboxyl phthalocyanine; rich hydroxyl groups on the surface of the composite polyol can be connected with hydroxyl groups on the surface of the nanofiber to form hydrogen bonds, due to the steric hindrance effect of the composite polyol, the fiber structure can become smaller and more uniform, the stability of the fiber structure is enhanced, the toughness of the fiber structure is further improved, meanwhile, the color of the fiber structure is more uniform, and therefore the optical performance of the fiber structure can be enhanced. The modifier can play a catalytic role when the composite polyol reacts with the nanofiber suspension, carboxyl in the modifier can be combined with hydroxyl on the surface of the nanofiber to form a hydrogen bond, the toughness of the nanofiber is further improved, and iron tetracarboxyl phthalocyanine and aluminum tetracarboxyl phthalocyanine have excellent optical characteristics, so that the composite polyol has excellent optical properties. Therefore, the optical performance of the flexible display cellulose liquid crystal device can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal fibers, and in particular to a fiber for a flexible display cellulose liquid crystal device and a preparation method thereof. Background Art

[0002] With the rapid development of science and technology, flexible display technology has become a hot topic of current research. Flexible display devices have the advantages of being thin, bendable, and portable, and show great application potential in smart phones, wearable devices, electronic paper and other fields. As a type of flexible display technology, cellulose liquid crystal devices have significant advantages in improving display quality and reducing costs due to their unique structure and performance. However, how to further improve the toughness and optical properties of flexible cellulose liquid crystal devices has become a key factor restricting their widespread application.

[0003] During the manufacturing process, traditional cellulose liquid crystal devices (LCDs) are prone to breakage or deformation when subjected to external forces due to the rigid structure and weak intermolecular interactions of cellulose, thus affecting their lifespan and stability. Furthermore, the optical performance of LCDs depends primarily on the arrangement and orientation of the liquid crystal molecules. However, in existing technologies, the arrangement of liquid crystal molecules is often uneven, resulting in scattering and polarization of light as it passes through the device, reducing display quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a fiber for flexible display cellulose liquid crystal device and a preparation method thereof, to solve the following technical problems:

[0005] How to improve the toughness and optical properties of liquid crystal fibers.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The present invention discloses a fiber for flexible display cellulose liquid crystal device, comprising the following raw materials in parts by weight: 70-90 parts of combed cotton, 5-15 parts of compound polyol, and 5-10 parts of modifier;

[0008] Preferably, the amount of combed cotton is 80 parts, the amount of complex polyol is 10 parts, and the amount of modifier is 8 parts.

[0009] In the technical solution of the present invention, the modifier comprises tetracarboxyl phthalocyanine iron and tetracarboxyl aluminum phthalocyanine in a mass ratio of 1:(2-4);

[0010] Preferably, the mass ratio of tetracarboxyphthalocyanine iron to tetracarboxyphthalocyanine aluminum in the modifier is 1:3.

[0011] Furthermore, the complex polyol is prepared by the following preparation method:

[0012] Step A: neopentyl glycol, methyl propylene glycol, and diethylene glycol are mixed and dried in an oven at 80° C. for 12 hours to obtain a mixture, the mixture is dissolved in ethanol, a catalyst and an inhibitor are added, and the mixture is stirred and reacted at 150-200° C. for 3 hours. After the reaction, the mixture is cooled to room temperature to obtain a crude material;

[0013] Step B: filtering and separating the crude material, and performing reduced pressure distillation on the obtained filter material to remove ethanol and other impurities, and finally obtaining a composite polyol.

[0014] Neopentyl glycol, methylpropylene glycol, and diethylene glycol all contain a large number of hydrophilic groups, namely hydroxyl groups. Under the action of a catalyst, the three react through some of the hydroxyl groups to form a cross-linked structure, forming a composite polyol with thermal and chemical stability. There are still many unreacted hydroxyl groups on the surface of the composite polyol, so it still maintains excellent dispersion properties in water.

[0015] Preferably, in step A, the mass ratio of the neopentyl glycol, methylpropylene glycol and diethylene glycol is 1:2:3.

[0016] Preferably, in step A, the amount of the catalyst used is 0.1%-0.5% of the mixed material amount, more preferably 0.3%.

[0017] Preferably, in step A, the amount of the inhibitor is 0.01%-0.1% of the mixed amount, more preferably 0.5%.

[0018] Preferably, the catalyst is tetrabutyl titanate or isopropyl titanate.

[0019] Preferably, the inhibitor is benzoquinone.

[0020] Furthermore, the modifier is prepared by the following preparation method:

[0021] Step M, dissolving tetracarboxyl phthalocyanine iron and tetracarboxyl aluminum phthalocyanine in an organic solvent and stirring uniformly, then adding acetic acid dropwise to adjust the pH to 4-5, and ultrasonically mixing for 2 hours to obtain a transparent mixed solution;

[0022] Step N: Place the mixed solution in a vacuum drying oven at 200° C. and dry for 4 hours. Grind the mixture after taking it out to obtain a powdered modifier.

[0023] Tetracarboxyl phthalocyanine iron and tetracarboxyl aluminum phthalocyanine have good catalytic activity and can use iron ions and aluminum ions as active centers to participate in the catalytic reaction. At the same time, both contain a large number of carboxyl groups and have excellent reaction activity.

[0024] Preferably, in step M, the organic solvent is any one of methanol, ethanol, acetone, dimethylformamide and dimethyl sulfoxide; more preferably methanol.

[0025] Preferably, in step M, the ratio of the total amount of tetracarboxyphthalocyanine iron and tetracarboxyphthalocyanine to the amount of the organic solvent is 1 g: (60-80) mL; more preferably 1 g: 70 mL.

[0026] In a second aspect, the present invention further discloses a method for preparing the fiber for the flexible display cellulose liquid crystal device as described above, characterized in that the method comprises the following steps:

[0027] S1. Grinding combed cotton to obtain combed cotton powder, adding 60%-70% by mass of concentrated sulfuric acid to the combed cotton powder, and then stirring at 45° C. for 2.5 hours to fully hydrolyze the combed cotton. After the reaction is completed, deionized water is added to terminate the reaction to obtain a reaction solution;

[0028] S2, centrifuging the reaction solution and removing the supernatant, retaining the precipitate, adding water to the precipitate, mixing, and centrifuging again, repeating this operation until the supernatant becomes colloidal, collecting the colloidal supernatant and dialyzing it until its pH reaches 7, and then heating and concentrating it at 80° C. to a nanofiber content of 5 wt%, thereby obtaining a nanofiber suspension;

[0029] S3, dissolving the modifier in water, stirring at 80°C, then adding the nanofiber suspension and stirring evenly, and finally adding the composite polyol and stirring evenly to obtain a mixed solution;

[0030] S4. The mixed solution is ultrasonically treated, and then poured into a mold. The mold is then transferred to a constant temperature box and dried at 25° C. for 6 hours. After being taken out, the mold is demoulded to obtain a fiber for a flexible display cellulose liquid crystal device.

[0031] Preferably, in step S1, the ratio of the combed cotton to concentrated sulfuric acid is 1 g:20 mL; and the amount of deionized water added is 8-10 times the amount of concentrated sulfuric acid.

[0032] Preferably, in step S3, the ratio of the modifier to water is 1 g:20 mL.

[0033] 1. The fibers for flexible display cellulose liquid crystal devices of the present invention contain a complex polyol composed of neopentyl glycol, methylpropylene glycol, and diethylene glycol. The abundant hydroxyl groups on the surface of the complex polyol will form hydrogen bonds with the hydroxyl groups on the surface of the nanofibers. Due to the steric hindrance effect of the complex polyol, the fiber structure can be made smaller and more uniform, thereby enhancing its stability and thereby improving its toughness. At the same time, its color is more uniform, thereby also enhancing its optical properties.

[0034] 2. A modifier composed of tetracarboxyphthalocyanine iron and tetracarboxyaluminum phthalocyanine is added to the fiber for flexible display cellulose liquid crystal device of the present invention. On the one hand, the modifier has a catalytic effect and can play a catalytic role in the reaction between the complex polyol and the nanofiber suspension, thereby promoting their reaction connection. On the other hand, tetracarboxyphthalocyanine iron and tetracarboxyaluminum phthalocyanine contain a large number of carboxyl groups, which can also combine with the hydroxyl groups on the surface of the nanofiber to form hydrogen bonds, thereby improving its toughness. In addition, tetracarboxyphthalocyanine iron and tetracarboxyaluminum phthalocyanine themselves have excellent optical properties, and therefore can also improve the optical performance of the flexible display cellulose liquid crystal device. DETAILED DESCRIPTION

[0035] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0037] Preparation Example 1

[0038] Preparation of complex polyols:

[0039] Step A: 10 g of neopentyl glycol, 20 g of methylpropylene glycol, and 30 g of diethylene glycol were mixed and dried in an oven at 80° C. for 12 h to obtain a mixture, which was dissolved in a stirring tank containing 500 mL of ethanol. 0.18 g of tetrabutyl titanate and 0.3 g of benzoquinone were added, and the mixture was stirred at 180° C. for 3 h. After the reaction, the mixture was cooled to room temperature to obtain a crude material.

[0040] Step B: filtering and separating the crude material, and performing reduced pressure distillation on the obtained filter material at 13.3 kPa and 60° C. to remove ethanol and other impurities to obtain a complex polyol.

[0041] Preparation Example 2

[0042] Preparation of modifier:

[0043] Step M: 5 g of tetracarboxylic iron phthalocyanine and 15 g of tetracarboxylic aluminum phthalocyanine were dissolved in 1400 mL of methanol and stirred evenly. Acetic acid was then added dropwise to adjust the pH to 4-5. The mixture was ultrasonically mixed for 2 h to obtain a transparent mixed solution.

[0044] Step N: Place the mixed solution in a vacuum drying oven at 200° C. and dry for 4 hours. Grind the mixture after taking it out to obtain a powdered modifier.

[0045] Example 1

[0046] Preparation of fibers for flexible display cellulose liquid crystal devices:

[0047] Step 1: 5 g of combed cotton was crushed to obtain combed cotton powder, 100 mL of 65% concentrated sulfuric acid was added to the combed cotton powder, and then stirred at 45 ° C for 2.5 hours to fully hydrolyze the combed cotton. After the reaction, deionized water was added to terminate the reaction to obtain a reaction solution containing nanofibers;

[0048] Step 2: After centrifuging the reaction solution, the supernatant was removed and the precipitate was retained. Water was added to the precipitate and mixed, and then centrifuged again. This operation was repeated until the supernatant was colloidal. The colloidal supernatant was collected and dialyzed until its pH reached 7. It was then heated at 80° C. and concentrated to a nanofiber content of 5 wt%, thereby obtaining a nanofiber suspension.

[0049] Step 3: Dissolve 0.5 g of the modifier in 10 mL of water and stir evenly at 80°C, then add the nanofiber suspension and stir evenly, and finally add 0.625 g of the complex polyol and stir evenly to obtain a mixed solution;

[0050] Step 4: ultrasonically treat the mixed solution at 1500 rpm for 15 minutes, then pour it into a glass mold with a thickness of 2 mm. Then transfer the mold to a constant temperature box and dry it at 25°C for 6 hours. After taking it out and demolding, the fiber for flexible display cellulose liquid crystal device is obtained.

[0051] Example 2

[0052] Preparation of fibers for flexible display cellulose liquid crystal devices:

[0053] Step 1: 4.375 g of combed cotton was crushed to obtain combed cotton powder, 87.5 mL of 60% concentrated sulfuric acid was added to the combed cotton powder, and then stirred at 45°C for 2.5 hours to fully hydrolyze the combed cotton. After the reaction, deionized water was added to terminate the reaction to obtain a reaction solution containing nanofibers;

[0054] Step 2: After centrifuging the reaction solution, the supernatant was removed and the precipitate was retained. Water was added to the precipitate and mixed, and then centrifuged again. This operation was repeated until the supernatant was colloidal. The colloidal supernatant was collected and dialyzed until its pH reached 7. It was then heated at 80° C. and concentrated to a nanofiber content of 5 wt%, thereby obtaining a nanofiber suspension.

[0055] Step 3: Dissolve 0.3125 g of the modifier in 6.25 mL of water and stir evenly at 80° C., then add the nanofiber suspension and stir evenly, and finally add 0.3125 g of the complex polyol and stir evenly to obtain a mixed solution;

[0056] Step 4: ultrasonically treat the mixed solution at 1500 rpm for 15 minutes, then pour it into a glass mold with a thickness of 2 mm. Then transfer the mold to a constant temperature box and dry it at 25°C for 6 hours. After taking it out and demolding, the fiber for flexible display cellulose liquid crystal device is obtained.

[0057] Example 3

[0058] Preparation of fibers for flexible display cellulose liquid crystal devices:

[0059] Step 1: 5.625 g of combed cotton was crushed to obtain combed cotton powder, 100 mL of 65% concentrated sulfuric acid was added to the combed cotton powder, and then stirred at 45°C for 2.5 hours to fully hydrolyze the combed cotton. After the reaction, deionized water was added to terminate the reaction to obtain a reaction solution containing nanofibers;

[0060] Step 2: After centrifuging the reaction solution, the supernatant was removed and the precipitate was retained. Water was added to the precipitate and mixed, and then centrifuged again. This operation was repeated until the supernatant was colloidal. The colloidal supernatant was collected and dialyzed until its pH reached 7. It was then heated at 80° C. and concentrated to a nanofiber content of 5 wt%, thereby obtaining a nanofiber suspension.

[0061] Step 3: Dissolve 0.625 g of the modifier in 12.5 mL of water and stir evenly at 80°C, then add the nanofiber suspension and stir evenly, and finally add 0.9375 g of the complex polyol and stir evenly to obtain a mixed solution;

[0062] Step 4: ultrasonically treat the mixed solution at 1500 rpm for 15 minutes, then pour it into a glass mold with a thickness of 2 mm. Then transfer the mold to a constant temperature box and dry it at 25°C for 6 hours. After taking it out and demolding, the fiber for flexible display cellulose liquid crystal device is obtained.

[0063] Comparative Example 1

[0064] Compared with Example 1, the only difference is that step three is eliminated, and in step four, ultrasonic treatment of the mixed solution at 1500 rpm for 15 min is eliminated, and the nanofiber suspension obtained in step two is directly poured into a glass mold for subsequent treatment. The other steps and conditions are exactly the same, and finally, fibers for flexible display cellulose liquid crystal devices are obtained.

[0065] Comparative Example 2

[0066] Compared with Example 1, the only difference is that in step 3, no modifier is added, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0067] Comparative Example 3

[0068] Compared with Example 1, the only difference is that in step 3, no complex polyol is added. The other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0069] Comparative Example 4

[0070] Compared with Example 1, the only difference is that in step 3, the complex polyol is replaced by neopentyl glycol, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0071] Comparative Example 5

[0072] Compared with Example 1, the only difference is that in step 3, the complex polyol is replaced by methyl propylene glycol, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0073] Comparative Example 6

[0074] Compared with Example 1, the only difference is that in step 3, the complex polyol is replaced by diethylene glycol, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0075] Comparative Example 7

[0076] Compared with Example 1, the only difference is that in step 3, the modifier is replaced by tetracarboxyl phthalocyanine iron, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0077] Comparative Example 8

[0078] Compared with Example 1, the only difference is that in step 3, the modifier is replaced by tetracarboxyaluminum phthalocyanine, and the other steps and conditions are exactly the same, and finally a fiber for flexible display cellulose liquid crystal device is prepared.

[0079] The fibers for flexible display cellulose liquid crystal devices prepared in Examples 1-3 and Comparative Examples 1-8 were subjected to performance tests, including mechanical performance tests and optical performance tests, and the test methods are as follows.

[0080] Mechanical Properties: A universal testing machine (AG-I C50kN) was used to test the stress of the fibers for flexible display cellulose liquid crystal devices. The fibers for flexible display cellulose liquid crystal devices were cut into rectangles of the same size (5cm*4cm). The samples were gently clamped in the universal testing machine to test their tensile strength and elongation.

[0081] Optical Properties: A double-beam UV-visible spectrophotometer (TU-1901, Beijing Puxi General Instrument Co., Ltd.) was used to characterize the optical properties of the fibers used in flexible display cellulose liquid crystal devices. A baseline correction was performed by selecting a reference sample and determining the measurement parameters. The sample was then placed on a test bench for measurement, and its transmission spectrum was measured. The trough of the transmission spectrum represents the peak value of the reflected light of the sample.

[0082] The test results are listed in Table 1, which is as follows:

[0083] Table 1

[0084] Tensile strength (MPa) Elongation (100%) Reflected light peak (nm) Example 1 95.6 21.2 512 Example 2 93.8 20.9 516 Example 3 94.5 20.8 528 Comparative Example 1 16.3 2.6 854 Comparative Example 2 41.3 10.5 156 Comparative Example 3 45.6 11.2 865 Comparative Example 4 25.6 6.5 714 Comparative Example 5 28.6 6.8 754 Comparative Example 6 20.6 5.9 771 Comparative Example 7 56.9 9.8 256 Comparative Example 8 52.8 11.5 321

[0085] Analysis of the data in Table 1 shows that the tensile strength and elongation of the flexible display cellulose liquid crystal device fibers obtained in Examples 1-3 are significantly higher than those in Comparative Examples 1-8, indicating that the flexible display cellulose liquid crystal device fibers of the present invention have stronger toughness. At the same time, compared with Comparative Examples 1-8, the reflected light peaks of the flexible display cellulose liquid crystal device fibers obtained in Examples 1-3 are all around 520 nm, which is in a moderate range and is neither too high nor too low, so their optical properties are better.

[0086] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A fiber for flexible display cellulose liquid crystal device, characterized in that: The method comprises the following raw materials in parts by weight: 70-90 parts of combed cotton, 5-15 parts of compound polyol, and 5-10 parts of modifier; Wherein, the modifier comprises tetracarboxyl phthalocyanine iron and tetracarboxyl aluminum phthalocyanine in a mass ratio of 1:(2-4).

2. The fiber for flexible display cellulose liquid crystal device according to claim 1, characterized in that: The complex polyol is prepared by the following preparation method: Step A: neopentyl glycol, methyl propylene glycol, and diethylene glycol are mixed and dried to obtain a mixture, the mixture is dissolved in ethanol, a catalyst and an inhibitor are added, and the mixture is stirred at 150-200° C. for 3 hours. After the reaction, the mixture is cooled to room temperature to obtain a crude material; Step B: filtering and separating the crude material, and performing reduced pressure distillation on the obtained filter material to obtain a composite polyol.

3. The fiber for flexible display cellulose liquid crystal device according to claim 2, characterized in that: In step A, the mass ratio of the neopentyl glycol, methylpropylene glycol and diethylene glycol is 1:2:3; the amount of the catalyst is 0.1%-0.5% of the mixed amount, and the amount of the inhibitor is 0.01%-0.1% of the mixed amount.

4. The fiber for flexible display cellulose liquid crystal device according to claim 3, characterized in that: The catalyst is tetrabutyl titanate or isopropyl titanate, and the inhibitor is benzoquinone.

5. The fiber for flexible display cellulose liquid crystal device according to claim 1, characterized in that: The modifier is prepared by the following preparation method: Step M, dissolving tetracarboxyl phthalocyanine iron and tetracarboxyl aluminum phthalocyanine in an organic solvent and stirring uniformly, then adding acetic acid dropwise to adjust the pH to 4-5, and ultrasonically mixing for 2 hours to obtain a transparent mixed solution; Step N: Place the mixed solution in a vacuum drying oven at 200° C. and dry for 4 hours. Grind the mixture after taking it out to obtain a powdered modifier.

6. The fiber for flexible display cellulose liquid crystal device according to claim 5, characterized in that: In step M, the organic solvent is any one of methanol, ethanol, acetone, dimethylformamide and dimethyl sulfoxide.

7. The fiber for flexible display cellulose liquid crystal device according to claim 5, characterized in that: In step M, the ratio of the total amount of tetracarboxy phthalocyanine iron and tetracarboxy aluminum phthalocyanine to the amount of the organic solvent is 1 g: (60-80) mL.

8. A method for preparing a fiber for a flexible display cellulose liquid crystal device according to any one of claims 1 to 7, characterized in that: Follow the steps below: S1. Grinding combed cotton to obtain combed cotton powder, adding 60%-70% by mass of concentrated sulfuric acid to the combed cotton powder, and then stirring at 45° C. for 2.5 hours. After the reaction is completed, deionized water is added to terminate the reaction to obtain a reaction solution; S2, centrifuging the reaction solution and removing the supernatant, retaining the precipitate, adding water to the precipitate, mixing, and centrifuging again, repeating this operation until the supernatant becomes colloidal, collecting the colloidal supernatant and dialyzing it until its pH reaches 7, and then heating and concentrating it at 80° C. to a nanofiber content of 5 wt%, thereby obtaining a nanofiber suspension; S3, dissolving the modifier in water, stirring at 80°C, then adding the nanofiber suspension and stirring evenly, and finally adding the composite polyol and stirring evenly to obtain a mixed solution; S4. The mixed solution is ultrasonically treated, and then poured into a mold. The mold is then transferred to a constant temperature box and dried at 25° C. for 6 hours. After being taken out, the mold is demoulded to obtain a fiber for a flexible display cellulose liquid crystal device.

9. The method for preparing fibers for flexible display cellulosic liquid crystal devices according to claim 8, characterized in that: In step S1, the ratio of the combed cotton to concentrated sulfuric acid is 1 g:20 mL; and the amount of deionized water added is 8-10 times the amount of concentrated sulfuric acid.

10. The method for preparing fibers for flexible display cellulose liquid crystal devices according to claim 8, characterized in that: In step S3, the ratio of the modifier to water is 1 g:20 mL.