Electroluminescent fiber and preparation method thereof

Abstract

The present invention relates to an electroluminescent fiber and a preparation method thereof. A solvent, a polymer binder and a luminescent powder are mixed, and then stirred to obtain a uniformly dispersed slurry; the conductor and the slurry are coaxially extruded through a porous composite spinneret, and then the slurry and two conductors wrapped therein are solidified and formed in one step through a coagulation bath to obtain a luminescent fiber; wherein each component unit in the porous composite spinneret is composed of a large channel wrapped with two parallel inner channels that can pass the conductors, wherein the two parallel inner channels are used to realize the drawing of the conductors, and the large channel is responsible for extruding the slurry; the luminescent fiber is washed with water to remove the surface coagulation bath liquid, and then dried to obtain the electroluminescent fiber. The method of the present invention can integrate the processes such as coating, molding and collection into a continuous production equipment, and the preparation process is simple and easy to realize industrial mass production. The brightness of the luminescent fiber prepared by this method is 10-100cd / m 2 , capable of lighting up luminous fibers over 100 meters in length.

Description

Technical Field

[0001] The invention belongs to the technical field of textile chemical fibers, and in particular relates to an electroluminescent fiber and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of information technology, the display technology accompanying it has shown a flourishing trend. People's requirements for display devices are increasing day by day. While meeting high resolution, they also put forward higher requirements for the portability, lightness and durability of display terminals. Compared with traditional cathode ray tube displays, plasma displays and liquid crystal displays, fabric display devices have great development prospects due to their significant advantages in flexibility and portability. Electroluminescent fibers used to prepare fabric displays are one of the key materials. Their preparation process and luminous effect will directly affect the performance and manufacturing cost of fabric displays.

[0003] Most of the electroluminescent fiber preparation methods reported so far use a coating process. The coating steps include batching, coating, drying, packaging, etc., which need to be completed step by step on multiple devices, and the coating process has strict requirements on the slurry ratio, viscosity, solid content, coating speed, drying process, etc. The steps are cumbersome and the process is complicated, which seriously affects the preparation efficiency and use effect of the luminescent fiber. Therefore, it is necessary to further develop new technologies for the manufacture of luminescent fibers to meet the development needs of flexible fabric display devices. The conventional wet spinning process is to extrude the slurry, form it through a coagulation bath, and then obtain a fibrous material after drying. The process is simple, the parameters are controllable, and it is easy to industrialize. Based on this, the present invention creatively pre-places the fiber electrode into the wet spinning die, then stretches the slurry and the fiber electrode synchronously, and finally forms it through a coagulation bath. After online drying, the integrated preparation of kilometer-level luminescent fibers is realized. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides an electroluminescent fiber and a preparation method thereof.

[0005] The present invention innovates the wet spinning process to continuously and integratedly prepare luminescent fibers. The present invention extrude fiber electrodes and luminescent slurry simultaneously through a multi-channel spinneret design, and then realizes the integrated construction of luminescent fibers through coagulation bath molding and online drying. The brightness of the luminescent fibers prepared by the present invention is 10-100 cd / m 2 , with diverse colors, and has achieved industrial-scale large-scale preparation of luminescent fibers.

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

[0007] The present invention first provides a method for preparing an electroluminescent fiber, specifically a wet spinning method, comprising the following steps:

[0008] (1) Preparation of luminescent slurry: mixing solvent, polymer binder and luminescent powder, and then mechanically stirring to obtain a uniformly dispersed slurry;

[0009] (2) Luminescent slurry extrusion molding: The conductor and slurry are coaxially extruded through a specially designed porous composite spinneret, and then the slurry and the two conductors wrapped therein are solidified in one step through a coagulation bath to obtain a luminescent fiber; wherein each component unit in the porous composite spinneret is composed of a large channel wrapped with two parallel inner channels that can pass the conductors, wherein the two parallel inner channels are used to realize the drawing of the conductors, and the large channel is responsible for extruding the slurry, and the entire process is drawn by a traction roller;

[0010] (3) Drying and packaging: The luminescent fiber prepared in step (2) is washed with water to remove the surface coagulation bath liquid, and then dried in an online hot air oven and collected into a roll to obtain the electroluminescent fiber. Thus, the integrated preparation of the electroluminescent fiber is completed.

[0011] In some embodiments of the present invention, in step (1), the solvent is selected from one or more of water, ethanol, acetone or N-methylpyrrolidone.

[0012] In some embodiments of the present invention, in step (1), the polymer binder is selected from one or more of carboxymethyl cellulose, sodium alginate, polyvinylidene fluoride resin, polyacrylate, polyurethane, polyethylene glycol, polyvinyl alcohol, styrene-butadiene rubber or polytetrafluoroethylene; the content of the polymer binder in the slurry is 1wt%-50wt%, wherein the preferred ratio is 2%-10%. The binder and the corresponding solvent should satisfy chemical compatibility.

[0013] In some embodiments of the present invention, in step (1), the luminescent powder is selected from one or more of SiO2-based luminescent powder, metal sulfide-type luminescent powder, GaN or Zn2SiO4, and the content of the luminescent powder in the slurry is 10wt%-80wt%, preferably 30wt%-50wt%. The solid content ratio is based on the viscosity. In some embodiments of the present invention, SiO2-based luminescent powder includes but is not limited to SiO2:Ge, SiO2:Er; metal sulfide-type luminescent powder includes but is not limited to CaS, SrS, ZnS, CaGa2S4, SrGa2S4.

[0014] In some embodiments of the present invention, in step (1), the viscosity of the slurry is 2000 mPa.s-100000 mPa.s, preferably 10000 mPa.s-50000 mPa.s.

[0015] In some embodiments of the present invention, in step (2), the wire is one or more of metal conductive fibers, metal composite fibers, and carbon fiber; the diameter of the wire is 10 μm-100 μm, and the conductivity is 10 -3 S / cm-10 2 S / cm, the best condition is 10-10 2 S / cm.

[0016] In some embodiments of the present invention, in step (2), the diameter of the external channel of each component unit in the porous composite spinneret is 0.01 mm-4.0 mm; the diameter ratio of the inner and outer channels is 1 / 20-2 / 5. The distance between the outer walls of the two parallel inner channels is kept equal to the distance between the outer wall of the inner channel and the inner wall of the outer channel in the diameter direction.

[0017] In some embodiments of the present invention, in step (2), the coagulation bath is selected from one or more of an alkaline solution with a pH>8, ethanol, boric acid, borax, a saturated sodium sulfate solution, or a salt solution containing a divalent metal ion.

[0018] In some embodiments of the present invention, in step (2), the concentration of the coagulation bath is 2 wt%-100 wt%, preferably 10-30 wt%.

[0019] In some embodiments of the present invention, in step (2) and step (3), the pulling speed is 1 m / min-50 m / min. In order to smoothly pull the luminescent fiber into shape, the pulling roller should be a two-roller wheel or a three-roller wheel.

[0020] In some embodiments of the present invention, in step (3), the drying temperature is 40°C-250°C, preferably 80°C-150°C; the drying time is 10s-400s, preferably 60s-200s.

[0021] On the basis of the above-mentioned preparation method provided by the present invention, the above-mentioned components and process conditions can be arbitrarily combined to obtain various preferred embodiments of the present invention.

[0022] The present invention also provides an electroluminescent fiber obtained based on the above preparation method.

[0023] Compared with the prior art, the positive and progressive effects of the present invention are:

[0024] (1) The present invention creatively improves the new coaxial wet spinning process, pre-places the fiber electrode in the equipment die, realizes the synchronous loading of the fiber electrode and the luminescent slurry, and completes the integrated preparation. The method of the present invention can integrate the coating, molding, collection and other processes into a continuous production equipment. The process is simple and efficient and suitable for industrial continuous production.

[0025] (2) The electroluminescent fiber prepared by the present invention has a controllable fiber diameter. The brightness of the luminescent fiber prepared by the present method is 10-100 cd / m 2 , which can light up luminous fibers over 100 meters in length, is beneficial for weaving large-scale luminous electronic textile devices.

[0026] (3) The reagents and raw materials used in the present invention are commercially available and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of preparing luminescent fibers by wet spinning.

[0028] Among them, 1 is a composite spinneret, 2 is a conducting wire, 3 is a slurry inlet, 4 is a coagulation bath tank, 5 is a coagulation bath, 6 is a traction roller, 7 is an air drying oven, and 8 is a wire collecting machine.

[0029] Figure 2 Schematic diagram of luminous fiber, wherein 2 is the conductor and 9 is the luminous layer. DETAILED DESCRIPTION

[0030] refer to Figure 1 The present invention provides a method for preparing an electroluminescent fiber, specifically a wet spinning method, comprising the following steps:

[0031] (1) Preparation of luminescent slurry: mixing solvent, polymer binder and luminescent powder, and then mechanically stirring to obtain a uniformly dispersed slurry;

[0032] (2) Luminescent slurry extrusion molding: The conductor 2 and the slurry entering from the slurry inlet 3 are coaxially extruded through the porous composite spinneret 1, and then the slurry and the two conductors wrapped therein are solidified in one step through the coagulation bath 5 in the coagulation bath tank 4 to obtain a luminescent fiber; wherein each component unit in the porous composite spinneret 1 is composed of a large channel wrapped with two parallel inner channels that can pass the conductors, wherein the two parallel inner channels are used to realize the drawing of the conductors, and the large channel is responsible for extruding the slurry, and the whole process is drawn by the traction roller 6;

[0033] (3) Drying and packaging: The luminescent fiber prepared in step (2) is washed with water to remove the surface coagulation bath liquid, and then dried in an online hot air drying oven 7, and then collected into a roll by a wire collecting machine 8 to obtain an electroluminescent fiber.

[0034] The obtained electroluminescent fiber structure includes two conductors 2 in the middle and a luminescent layer 9 on the outside.

[0035] At this point, the integrated preparation of electroluminescent fibers has been completed.

[0036] In step (1), the solvent is selected from one or more of water, ethanol, acetone or N-methylpyrrolidone.

[0037] In step (1), the polymer binder is selected from one or more of carboxymethyl cellulose, sodium alginate, polyvinylidene fluoride resin, polyacrylate, polyurethane, polyethylene glycol, polyvinyl alcohol, styrene-butadiene rubber or polytetrafluoroethylene; the content of the polymer binder in the slurry is 1wt%-50wt%, wherein the preferred ratio is 2%-10%. The binder and the corresponding solvent should meet chemical compatibility.

[0038] In step (1), the luminescent powder is selected from one or more of SiO2-based luminescent powder, metal sulfide-type luminescent powder, GaN or Zn2SiO4, and the content of the luminescent powder in the slurry is 10wt%-80wt%, preferably 30wt%-50wt%. The solid content ratio is based on the viscosity. In some embodiments of the present invention, SiO2-based luminescent powders include but are not limited to SiO2:Ge, SiO2:Er; metal sulfide-type luminescent powders include but are not limited to CaS, SrS, ZnS, CaGa2S4, SrGa2S4.

[0039] In step (1), the viscosity of the slurry is 2000mPa.s-100000mPa.s, and the preferred ratio is 10000mPa.s-50000mPa.s.

[0040] In step (2), the wire is one or more of metal conductive fibers, metal composite fibers, and carbon fiber; the diameter of the wire is 10 μm-100 μm, and the conductivity is 10 -3 S / cm-10 2 S / cm, the best condition is 10-10 2 S / cm.

[0041] In step (2), the diameter of the external channel of each component unit in the porous composite spinneret is 0.01 mm-4.0 mm; the diameter ratio of the inner and outer channels is 1 / 20-2 / 5. The distance between the outer walls of the two parallel inner channels is kept equal to the distance between the outer wall of the inner channel and the inner wall of the outer channel in the diameter direction.

[0042] In step (2), the coagulation bath is selected from one or more of an alkaline solution with a pH value greater than 8, ethanol, boric acid, borax, a saturated sodium sulfate solution, or a salt solution containing divalent metal ions.

[0043] In step (2), the concentration of the coagulation bath is 2wt%-100wt%, preferably 10-30wt%.

[0044] In step (2) and step (3), the pulling speed is 1 m / min-50 m / min. In order to smoothly pull the luminescent fiber into shape, the pulling roller should be a two-roller wheel or a three-roller wheel.

[0045] In step (3), the drying temperature is 40°C-250°C, preferably 80°C-150°C; the drying time is 10s-400s, preferably 60s-200s.

[0046] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. Experimental methods without specific conditions in the examples are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0047] In the present invention, room temperature refers to an ambient temperature of 15°C-30°C.

[0048] The reagents used in the following examples are all purchased reagents, and various solvents are purchased from Sinopharm Chemical Reagent Co., Ltd. All equipment in the following examples are commercially available equipment.

[0049] Example 1

[0050] Step 1: At room temperature 25°C, add 2g of sodium alginate to 98g of deionized water and stir for 2 hours at a stirring speed of 500rpm to form a sodium alginate sol. Then add 100g of SiO2:Ge luminescent powder (diameter 10μm) to the sodium alginate sol and stir for 30min at a stirring speed of 300rpm to obtain a uniformly dispersed luminescent slurry.

[0051] Step 2: Add 10kg of calcium chloride into 90kg of deionized water, stir evenly and pour into a coagulation bath that is 10 meters long and 10cm deep.

[0052] Step 3: Pass two copper fibers (100 μm in diameter) through the inner channel of the spinneret. Then pour the slurry into the barrel and extrude it through the spinneret, while drawing the copper fibers at a speed of 5 m / min, so that the copper fibers and the slurry flow into the coagulation bath at the same time. After 2 minutes in the coagulation bath, the luminous fiber is formed.

[0053] Step 4: air-dry the formed luminescent fiber at 70°C for 10 minutes to obtain an electroluminescent fiber.

[0054] Example 2

[0055] Step 1: Add 10 g of polyvinyl alcohol into 98 g of deionized water at 90° C. and stir for 2 hours at a stirring speed of 500 rpm to form a polyvinyl alcohol sol.

[0056] Step 2: Then add 120g ZnS luminescent powder (diameter 10μm) into the polyvinyl alcohol sol and stir for 60min at a stirring speed of 300rpm to obtain a uniformly dispersed luminescent slurry.

[0057] Step 3: Add 3kg of borax into 100kg of saturated sodium sulfate solution, stir evenly and pour into the coagulation bath.

[0058] Step 4: Pass two carbon fibers (100 μm in diameter) through the inner channel of the spinneret. Then pour the slurry into the barrel and extrude it through the spinneret. At the same time, draw the carbon fiber at a speed of 3 m / min, so that the carbon fiber and the slurry flow into the coagulation bath at the same time. After 5 minutes in the coagulation bath, the luminous fiber is formed.

[0059] Step 5: Air-dry the formed luminescent fiber at 80° C. for 15 minutes to obtain an electroluminescent fiber.

[0060] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing an electroluminescent fiber, characterized in that: The steps include: (1) Preparation of luminescent slurry: Mix the solvent, polymer binder and luminescent powder, and then stir to obtain a uniformly dispersed slurry; (2) Luminescent slurry extrusion molding: The conductor and slurry are coaxially extruded through a porous composite spinneret, and then the slurry and the two conductors wrapped therein are solidified in one step through a coagulation bath to obtain a luminescent fiber; wherein each component unit in the porous composite spinneret is composed of a large channel wrapped with two parallel inner channels that can pass the conductor, wherein the two parallel inner channels are used to realize the drawing of the conductor, and the large channel is responsible for extruding the slurry, and the entire process is drawn by a pulling roller; (3) Drying and packaging: The luminescent fiber prepared in step (2) is washed with water to remove the surface coagulation bath liquid, and then dried and collected into a roll to obtain an electroluminescent fiber; The content of the polymer binder in the slurry is 2%-10%, the content of the luminescent powder in the slurry is 30 wt%-50wt%; the viscosity of the slurry is 10000 mPa.s-50000 mPa.s; The diameter of the wire is 10μm-100μm; The coagulation bath is selected from one or more of an alkaline solution with a pH>8, ethanol, boric acid, borax, a saturated sodium sulfate solution, or a salt solution containing a divalent metal ion; the concentration of the coagulation bath is 10-30wt%; In step (1), the polymer binder is selected from one or more of carboxymethyl cellulose, sodium alginate, polyvinylidene fluoride resin, polyacrylate, polyurethane, polyethylene glycol, polyvinyl alcohol, styrene-butadiene rubber or polytetrafluoroethylene; In step (1), the luminescent powder is selected from one or more of SiO2-based luminescent powder, metal sulfide-based luminescent powder, GaN or Zn2SiO4.

2. The method for preparing an electroluminescent fiber according to claim 1, characterized in that: In step (1), the solvent is selected from one or more of water, ethanol, acetone or N-methylpyrrolidone.

3. The method for preparing an electroluminescent fiber according to claim 1, characterized in that: In step (2), the conductor is one or more of metal conductive fibers, metal composite fibers, and carbon fiber; the conductivity is 10 -3 S / cm -10 2 S / cm.

4. The method for preparing an electroluminescent fiber according to claim 3, characterized in that: In step (2), the electrical conductivity of the wire is 10-10 2 S / cm.

5. The method for preparing an electroluminescent fiber according to claim 1, characterized in that: In step (2), the diameter of the external channel of each component unit in the porous composite spinneret is 0.01 mm-4.0 mm; and the diameter ratio of the inner and outer channels is 1 / 20-2 / 5.

6. The method for preparing an electroluminescent fiber according to claim 1, characterized in that: In step (2) and step (3), the pulling speed is 1 m / min-50 m / min.

7. The method for preparing an electroluminescent fiber according to claim 1, characterized in that: In step (3), the drying temperature is 40°C-250°C, and the drying time is 10s-400s.

8. The method for preparing an electroluminescent fiber according to claim 7, characterized in that: In step (3), the drying temperature is 80°C-150°C; and the drying time is 60s-200s.

9. An electroluminescent fiber, characterized in that: An electroluminescent fiber obtained based on the preparation method according to any one of claims 1 to 8.

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