Electroluminescent and thermochromic tunable color light emitting fibers and methods of making

Abstract

The present application relates to the technical field of smart electronic fibers, and particularly relates to an electrofluorescent and thermochromic color-adjustable light-emitting fiber and a preparation method, the light-emitting fiber comprises at least two conductive layers, a light-emitting color-changing layer and an insulating encapsulation layer, the light-emitting color-changing layer comprises two layers of electrofluorescent active layers and thermochromic active layers; the light-emitting color-changing layer is adjacent to the conductive layer, and the insulating encapsulation layer is located at the outermost layer of the light-emitting fiber. The electrofluorescent mode and the thermochromic mode in the light-emitting fiber can work independently or simultaneously, can realize relatively stable control of the light-emitting effect, can also realize real-time regulation and control of the color of the color-changing fiber, and provides a solution for future smart color-changing light-emitting fiber materials.

Description

Technical Field

[0001] This invention relates to an electroluminescent and thermochromic tunable luminescent fiber and its preparation method, belonging to the field of intelligent electronic fiber technology. Background Technology

[0002] Smart wearable electronics have garnered significant attention due to their advantages such as lightweight, flexibility, portability, and low power consumption. By combining various functional materials using physical or chemical strategies, wearable electronics can possess a range of basic functions, including light emission, heat generation, power generation, and sensing. Traditional planar and thin-film wearable electronics exhibit excellent and stable optoelectronic performance, but at the cost of breathability and comfort for a better user experience. In contrast, emerging wearable electronics based on functional fibers effectively combine the technological advantages of wearability, scalability, miniaturization, high adaptability, and multifunctionality, demonstrating greater development potential.

[0003] Among them, luminescent fiber electronic devices have numerous applications in portable lighting, displays, warning signs, warning clothing, and fashion apparel (such as traffic safety vests and recreational clothing). Furthermore, through reasonable selection of constituent materials and device structure design, luminescent fiber electronic devices have exhibited unique advantages such as high strength and brightness, good stretchability, excellent abrasion resistance, and outstanding water resistance; however, they typically emit monochromatic light. To broaden the range of emitted colors, one approach is to simply physically blend luminescent powders with different properties and adjust the mixing ratios to obtain multi-colored luminescent devices, or to introduce a light conversion layer, such as a red fluorescent dye, and adjust its content to achieve different colors of emission. However, the color change achieved through these methods is essentially a non-real-time and static process, making it difficult to achieve real-time dynamic control of multiple emitted colors in a single luminescent device. Research on multi-color or even color-changing luminescent fiber devices is still in its early stages. Exploring dynamic electroluminescent fiber devices with multi-color displays is an important foundation for future smart and wearable textiles.

[0004] Therefore, there is an urgent need for an electroluminescent fiber that can achieve dynamic color changing, and which has the characteristics of simple preparation process, mass production capability, and controllable fiber diameter and structure during the fiber preparation process, in order to meet the market demand for electroluminescent fibers. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing an electroluminescent and thermochromic tunable luminescent fiber and its preparation method. The electroluminescent and thermochromic modes in the luminescent fiber can operate independently or simultaneously, enabling relatively stable control of the luminescence effect and real-time adjustment of the color of the color-changing fiber, thus providing a solution for future intelligent color-changing luminescent fiber materials.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an electroluminescent and thermochromic tunable light-emitting fiber, the light-emitting fiber comprising at least two conductive layers, a light-emitting color-changing layer and an insulating encapsulation layer, wherein the light-emitting color-changing layer is a material that has both light-emitting and thermochromic functions, or the light-emitting color-changing layer comprises two layers: an electroluminescent active layer and a thermochromic active layer.

[0007] The light-emitting color-changing layer is adjacent to the conductive layer, and the insulating encapsulation layer is located on the outermost layer of the light-emitting fiber.

[0008] Furthermore, the conductive layer includes a core fiber electrode and an outer electrode conductive layer, wherein the core fiber electrode is the innermost layer of the luminescent fiber.

[0009] Furthermore, the luminescent fiber comprises, from the inside out, a core fiber electrode, an electroluminescent active layer, a thermochromic active layer, an outer electrode conductive layer, and an insulating encapsulation layer.

[0010] Alternatively, the luminescent fiber may include, from the inside out, a core fiber electrode, an electroluminescent active layer, an outer electrode conductive layer, a thermochromic active layer, and an insulating encapsulation layer.

[0011] Alternatively, the luminescent fiber may include, from the inside out, a core fiber electrode, a luminescent color-changing layer, an outer electrode conductive layer, and an insulating encapsulation layer.

[0012] Furthermore, the core fiber electrode is any one or more of metal conductive fibers, metal composite fibers, and carbon material fibers; the diameter of the core fiber electrode is 100-300 μm, and the conductivity is 10. -2 -10 2 S / cm;

[0013] The conductive layer of the external electrode is any one or more of the following: silver nanowires, adhesives containing metal particles, metal wires, chemical fibers containing metal particles, and carbon nanofibers.

[0014] This invention also discloses a method for preparing electroluminescent and thermochromic tunable luminescent fibers, wherein the preparation method is as follows:

[0015] S1. Preparation of electroluminescent paste, thermochromic paste, and mixed luminescent paste: Electroluminescent paste is obtained by uniformly mixing electroluminescent material, solvent, polymer binder, and dispersant; thermochromic paste is obtained by uniformly mixing thermochromic material, solvent, polymer binder, and dispersant; electroluminescent paste is obtained by uniformly mixing electroluminescent material, thermochromic material, solvent, polymer binder, and dispersant.

[0016] S2. Construction of the light-emitting color-changing layer and the outer electrode conductive layer: The mixed light-emitting paste is coated on the outer surface of the core fiber electrode and then dried to obtain the light-emitting color-changing layer. Then, the outer electrode conductive layer material is loaded on the outer surface of the light-emitting color-changing layer.

[0017] Alternatively, the electroluminescent paste and the thermochromic paste are sequentially coated on the outer surface of the core fiber electrode, and then dried to obtain a luminescent and color-changing layer. Then, the outer electrode conductive layer material is loaded onto the outer surface of the luminescent and color-changing layer.

[0018] Alternatively, the electroluminescent paste is coated on the outer surface of the core fiber electrode and then dried to obtain an electroluminescent active layer. Then, the outer electrode conductive layer material is loaded on the outer surface of the thermochromic active layer to form an outer electrode conductive layer. Then, thermochromic paste is coated on the outer surface of the outer electrode conductive layer and dried to obtain a thermochromic active layer.

[0019] S3. Construction of the insulating encapsulation layer: Insulating transparent polymer is used for insulating encapsulation, and after drying and winding, electroluminescent and thermochromic tunable luminescent fibers are obtained.

[0020] Furthermore, the electroluminescent material is one or more of SiO2-based luminescent powder, metal sulfide luminescent powder, GaN, or Zn2SiO4; the particle size of the electroluminescent material is 5-40 μm, and the mass content of the electroluminescent material in the electroluminescent paste is 10-80 wt%.

[0021] The thermochromic material is a microcapsule-structured thermochromic material, and the mass content of the thermochromic material in the thermochromic slurry is 10-30 wt%.

[0022] The electroluminescent material has a mass content of 20-70 wt% in the luminescent mixture, and the thermochromic material has a mass content of 10-30 wt% in the luminescent mixture.

[0023] Furthermore, the polymer binder is any one or more of polyvinyl alcohol, polyurethane, vinyl acetate, acrylic, epoxy resin, phenolic resin, and silicone resin; the polymer binder has a mass content of 1-50 wt% in the electroluminescent paste, thermochromic paste, or luminescent mixed paste.

[0024] The dispersant is any one or more of aqueous siloxanes, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, Tween 80, and hexadecyltrimethylammonium chloride, and the mass content of the dispersant in the electroluminescent paste, thermochromic paste, or luminescent mixed paste is 0.5-1 wt%.

[0025] The solvent is any one or more of water, ethanol, acetone or N-methylpyrrolidone.

[0026] Furthermore, the insulating transparent polymer is any one or more of epoxy resin, acrylate resin, polyurethane resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin, and silicone resin.

[0027] Furthermore, the thickness of the electroluminescent active layer is 20-150 μm;

[0028] The thickness of the thermochromic active layer is 10-50 μm;

[0029] The thickness of the conductive layer of the outer electrode is 5-50 μm;

[0030] The thickness of the insulating encapsulation layer is 10-80 μm.

[0031] Furthermore, the drying temperature is 60-180℃, and the drying time is 5-15s.

[0032] The beneficial effects of this invention are:

[0033] The thermochromic material added inside the luminescent fiber of the present invention can change color in response to changes in ambient temperature. It has the excellent characteristic of a wide spectral adjustment range, which enables the luminescent fiber to achieve reversible control of optical properties and color changes through direct and indirect means from the outside.

[0034] The electroluminescent and thermochromic modes in the luminescent fibers can operate independently or simultaneously. When both modes operate simultaneously, the color of the electroluminescent active layer can harmonize with the color change of the thermochromic active layer to achieve a luminous effect. By controlling the DC power supply voltage in the thermochromic mode, real-time color variation and multi-color display can be achieved on a single luminescent fiber, providing a solution for future intelligent color-changing luminescent fiber materials.

[0035] Compared with existing technologies, the luminescent fiber of this invention has a simple structure, is easy to prepare, can be mass-produced, has controllable filament diameter, and can achieve real-time color adjustment. The luminescent fiber has a good luminescent effect. The combination of the electroluminescent active layer and the thermochromic active layer allows the colors of the two luminescent layers to be mutually harmonized, achieving a relatively stable control of the luminescent effect. At the same time, it can also adjust the color change of the luminescent fiber in real time, effectively meeting the market demand for real-time color-changing luminescent fibers. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the working process of the light-emitting fiber;

[0037] Figure 2 This is a schematic diagram of the cross-section of the light-emitting fiber in Example 1;

[0038] Figure 3 This is a schematic diagram of the cross-section of the light-emitting fiber in Example 2;

[0039] Figure 4 This is a schematic diagram of the cross-section of the light-emitting fiber in Example 3;

[0040] In the figure, 1 is the core fiber electrode; 2 is the luminescent and color-changing layer; 3 is the outer electrode conductive layer; 4 is the insulating encapsulation layer; 5 is the electroluminescent active layer; and 6 is the thermochromic active layer. Detailed Implementation

[0041] The specific embodiments of the present invention will be described in detail below. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used is for describing particular embodiments only and is not intended to limit the invention.

[0043] A luminescent fiber that is electroluminescent and thermochromic and can be tunable, the luminescent fiber comprising at least two conductive layers, a luminescent color-changing layer and an insulating encapsulation layer, wherein the luminescent color-changing layer is a material that has both luminescent and thermochromic functions, or the luminescent color-changing layer comprises two layers: an electroluminescent active layer and a thermochromic active layer.

[0044] The light-emitting color-changing layer is adjacent to the conductive layer, and the insulating encapsulation layer is located on the outermost layer of the light-emitting fiber.

[0045] Specifically, the conductive layer includes a core fiber electrode and an outer electrode conductive layer, wherein the core fiber electrode is the innermost layer of the luminescent fiber.

[0046] Specifically, the luminescent fiber comprises, from the inside out, a core fiber electrode, an electroluminescent active layer, a thermochromic active layer, an outer electrode conductive layer, and an insulating encapsulation layer;

[0047] Alternatively, the luminescent fiber may include, from the inside out, a core fiber electrode, an electroluminescent active layer, an outer electrode conductive layer, a thermochromic active layer, and an insulating encapsulation layer.

[0048] Alternatively, the luminescent fiber may include, from the inside out, a core fiber electrode, a luminescent color-changing layer, an outer electrode conductive layer, and an insulating encapsulation layer.

[0049] Specifically, the core fiber electrode is any one or more of metal conductive fibers, metal composite fibers, and carbon material fibers; the diameter of the core fiber electrode is 100-300 μm, and the conductivity is 10.-2 -10 2 S / cm.

[0050] Preferably, the conductivity of the core fiber electrode is 10⁻¹⁰. 2 S / cm.

[0051] The conductive layer of the external electrode is any one or more of the following: silver nanowires, adhesives containing metal particles, metal wires, chemical fibers containing metal particles, and carbon nanofibers.

[0052] When the silver nanowires or the adhesive containing metal particles form a conductive layer, the thickness is 5-20 μm.

[0053] The diameter of the metal wire is 20-50 μm; the diameter of the chemical fiber containing metal particles is 20-50 μm, and the diameter of the carbon nanofiber is 20-50 μm; wherein, the chemical fiber containing metal particles is any one of copper-plated yarn, tin-plated yarn, or stainless steel yarn.

[0054] A method for preparing electroluminescent and thermochromic tunable luminescent fibers, wherein the preparation method is as follows:

[0055] S1. Preparation of electroluminescent paste, thermochromic paste, and mixed luminescent paste: Electroluminescent paste is obtained by uniformly mixing electroluminescent material, solvent, polymer binder, and dispersant; thermochromic paste is obtained by uniformly mixing thermochromic material, solvent, polymer binder, and dispersant; electroluminescent paste is obtained by uniformly mixing electroluminescent material, thermochromic material, solvent, polymer binder, and dispersant.

[0056] S2. Construction of the light-emitting color-changing layer and the outer electrode conductive layer: The mixed light-emitting paste is coated on the outer surface of the core fiber electrode and then dried to obtain the light-emitting color-changing layer. Then, the outer electrode conductive layer material is loaded on the outer surface of the light-emitting color-changing layer.

[0057] Alternatively, the electroluminescent paste and the thermochromic paste are sequentially coated on the outer surface of the core fiber electrode, and then dried to obtain a luminescent and color-changing layer. Then, the outer electrode conductive layer material is loaded onto the outer surface of the luminescent and color-changing layer.

[0058] Alternatively, the electroluminescent paste is coated on the outer surface of the core fiber electrode and then dried to obtain an electroluminescent active layer. Then, the outer electrode conductive layer material is loaded on the outer surface of the thermochromic active layer to form an outer electrode conductive layer. Then, thermochromic paste is coated on the outer surface of the outer electrode conductive layer and dried to obtain a thermochromic active layer.

[0059] S3. Construction of the insulating encapsulation layer: Insulating transparent polymer is used for insulating encapsulation, and after drying and winding, electroluminescent and thermochromic tunable luminescent fibers are obtained.

[0060] Specifically, the electroluminescent material is one or more of SiO2-based luminescent powder, metal sulfide luminescent powder, GaN, or Zn2SiO4; the particle size of the electroluminescent material is 5-40 μm, and the mass content of the electroluminescent material in the electroluminescent paste is 10-80 wt%.

[0061] Preferably, the electroluminescent material has a mass content of 30-50 wt% in the electroluminescent paste.

[0062] The SiO2-based luminescent powder includes, but is not limited to, SiO2:Ge and SiO2:Er; the metal sulfide luminescent powder includes, but is not limited to, CaS, SrS, ZnS, CaGa2S4, SrGa2S4, and (Zn, Cd)S:Cu luminescent powder.

[0063] The thermochromic material is an organic or inorganic thermochromic material that can undergo reversible color changes with temperature. The thermochromic material can be a single or composite thermochromic material, including but not limited to different types of thermochromic materials with different response temperatures, and / or different types of thermochromic materials with the same response temperature but different response colors.

[0064] The thermochromic material is a microcapsule-structured thermochromic material, which better protects it from damage during use. The mass content of the thermochromic material in the thermochromic slurry is 10-30 wt%.

[0065] The electroluminescent material has a mass content of 20-70 wt% in the luminescent mixture, and the thermochromic material has a mass content of 10-30 wt% in the luminescent mixture.

[0066] More specifically, in actual production applications, functional modification materials can be added to the thermochromic active layer as needed. The modification materials are one or more of heat stabilizers, plasticizers, antistatic agents, or UV stabilizers, but are not limited to these.

[0067] Specifically, the polymer binder is any one or more of polyvinyl alcohol, polyurethane, vinyl acetate, acrylic acid, epoxy resin binder, phenolic resin binder, and silicone resin binder; the polymer binder has a mass content of 1-50 wt% in the electroluminescent paste, thermochromic paste, or luminescent mixed paste.

[0068] Preferably, the polymer binder has a mass content of 2-10 wt% in the electroluminescent or thermochromic paste. The polymer binder and the corresponding solvent should meet the requirements of chemical compatibility.

[0069] The dispersant is any one or more of aqueous siloxanes, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, Tween 80, and hexadecyltrimethylammonium chloride, and the mass content of the dispersant in the electroluminescent paste, thermochromic paste, or luminescent mixed paste is 0.5-1 wt%.

[0070] The solvent is any one or more of water, ethanol, acetone or N-methylpyrrolidone.

[0071] Specifically, the insulating transparent polymer is any one or more of epoxy resin, acrylate resin, polyurethane resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin, and silicone resin.

[0072] Specifically, the thickness of the electroluminescent active layer is 20-150 μm; preferably, the thickness of the electroluminescent active layer is 40-100 μm.

[0073] Specifically, the thickness of the thermochromic active layer is 10-50 μm; preferably, the thickness of the thermochromic active layer is 10-30 μm.

[0074] More preferably, the thickness of the thermochromic active layer is (H±5) μm, where H=0.3h+5, and h is the thickness of the electroluminescent active layer, with the unit of h being μm. The coordinated thicknesses of the electroluminescent active layer and the thermochromic active layer are more conducive to the luminescent and color-changing properties of the luminescent fiber.

[0075] Specifically, the thickness of the conductive layer of the outer electrode is 5-50 μm;

[0076] Specifically, the thickness of the insulating encapsulation layer is 10-80 μm; preferably, the thickness of the insulating encapsulation layer is 20-50 μm.

[0077] Specifically, the drying temperature is 60-180℃, the drying time is 5-15s, and the winding speed is 5-20m / min.

[0078] Preferably, the drying temperature is 100-140℃.

[0079] The electroluminescent mode and thermochromic mode in the luminescent fiber described in this invention can work independently or simultaneously.

[0080] Electroluminescent mode: A driving device with a driving AC voltage of 30-500V and a driving frequency of 50-8000Hz is used to connect the core fiber electrode and the electrode conductive layer at one end of the light-emitting fiber to light up the light-emitting fiber.

[0081] Thermochromic mode: A DC power supply with a voltage of 0-50V is connected to both ends of the conductive electrode layer of the luminescent fiber. The conductive electrode layer itself has resistance, and the Joule heat generated by the luminescent fiber can be controlled by adjusting the DC power supply voltage, further regulating the temperature of the luminescent fiber itself in real time. The color of the thermochromic active layer in the middle changes with temperature, thus achieving the color-changing effect. The specific working principle is as follows... Figure 1 As shown.

[0082] Specifically, all reagents used in the examples were purchased externally, with all solvents sourced from Sinopharm Chemical Reagent Co., Ltd. The thermochromic material used in the examples was from Shenzhen Huancai Color Changing Technology Co., Ltd., specifically as thermochromic microcapsules. The particles are spherical with an average diameter of 2-7 μm. The interior contains the color-changing substance, while the exterior is a transparent, insoluble, and non-melting shell approximately 0.2-0.5 μm thick, protecting the color-changing substance from corrosion by other chemicals. All equipment used in the examples was commercially available. Room temperature refers to an ambient temperature of 10℃-30℃.

[0083] The thermochromic materials described in the embodiments are as follows: Thermochromic material A: changes from colorless to red at 40℃; Thermochromic material B: changes from violet to colorless at 31℃; Thermochromic material C: changes color at multiple temperatures, is dark green below 25℃, turns orange-yellow as the temperature increases, and becomes light pink above 31℃. The temperatures mentioned refer to the final temperature at which the transformation is completed.

[0084] The luminescent fibers prepared in the examples were subjected to color testing, with the Pantone color chart as the color standard.

[0085] Example 1

[0086] Step 1: At room temperature (25℃), 50g of (Zn, Cd)S:Cu luminescent powder (average particle size 25μm, national standard grade D522, Shanghai Keyan Optoelectronic Technology Co., Ltd.) was added to 30g of ethanol solvent. Then, 19.5g of polyvinyl alcohol binder (Kuraray International Trading Shanghai Co., Ltd.) and 0.5g of sodium dodecylbenzenesulfonate were added. The mixture was magnetically stirred for 30min at a stirring speed of 300rpm to obtain a uniformly dispersed electroluminescent slurry. 20g of thermoluminescent material A was added to 30g of water, followed by 19.5g of polyvinyl alcohol binder and 0.5g of sodium dodecylbenzenesulfonate. The mixture was magnetically stirred for 30min at a stirring speed of 300rpm to obtain a uniformly dispersed thermochromic slurry.

[0087] Step 2: The dip-coating device is activated, and the prepared electroluminescent paste and thermochromic paste are uniformly coated onto the core layer fiber electrode copper wire nylon core-spun conductive yarn (diameter 210 μm, Laiwu Longzhi Metal Yarn Co., Ltd.) at a speed of 10 m / min. After drying at 120°C, the mixture is finally collected on a roller. The thickness of the electroluminescent active layer is 70 μm, and the thickness of the thermochromic active layer is 25 μm.

[0088] Step 3: Turn on the twisting device and incorporate the copper wire (30μm in diameter) into the fiber by winding to form an outer electrode conductive layer with a thickness of 30μm.

[0089] Step 4: The encapsulation device is activated, and a 50 wt% aqueous solution of water-based epoxy resin (product model F0716, Shenzhen Yoshida Chemical Co., Ltd.) is uniformly coated onto the fiber surface at a speed of 8 m / min. The fiber is then dried online at 100°C, forming an insulating encapsulation layer with a thickness of 50 μm. Finally, the luminescent fibers are collected and wound onto a spool. The resulting cross-sectional view of the luminescent fiber is shown below. Figure 2 As shown.

[0090] The core fiber electrode and the outer conductive layer are peeled off from one end of the prepared luminescent fiber. A driving device with an AC voltage of 80V and a driving frequency of 1000Hz is used to connect the core fiber electrode and the outer conductive layer. The outer conductive layer is peeled off from the other end of the luminescent fiber, and a power supply with a DC voltage adjustment range of 0-10V is used to connect the two ends of the outer conductive layer. The high-voltage AC driving device is turned on, and the color-changing effect is achieved by adjusting the voltage of the DC power supply.

[0091] Example 2

[0092] Step 1: At room temperature (25℃), add 50g of ZnS:Cu luminescent powder (average particle size 25μm, national standard grade D502, Shanghai Keyan Optoelectronic Technology Co., Ltd.) and 20g of thermochromic material B to 60g of water, then add 39g of polyvinyl alcohol binder (Kuraray International Trading Shanghai Co., Ltd.) and 1g of sodium dodecylbenzenesulfonate, and magnetically stir for 30min at a stirring speed of 300rpm to obtain a uniformly dispersed mixed luminescent slurry.

[0093] Step 2: Turn on the dip-coating device and uniformly coat the prepared mixed luminescent paste onto the surface of the core fiber electrode copper wire nylon core-spun conductive yarn (diameter 210μm, Laiwu Longzhi Metal Yarn Co., Ltd.) at a speed of 10m / min. After drying at 120℃, it is finally collected on a roller. The total thickness of the luminescent color-changing layer is 100μm.

[0094] Step 3: Turn on the dip coating device and uniformly coat the core fiber electrode copper wire composite fiber material with ITO dispersion (13% amount, Yantai Jialong Nano Industry Co., Ltd.) at a speed of 10m / min. Dry it at 120℃ to form a conductive coating with a thickness of 10μm. Turn on the twisting device and incorporate copper wire fiber (30μm in diameter) into the fiber by winding to form an outer electrode conductive layer with a thickness of 35μm.

[0095] Step 4: The encapsulation device is activated, and 50 wt% aqueous polyurethane emulsion (product model F0410, Shenzhen Yoshida Chemical Co., Ltd.) is uniformly coated onto the fiber surface at a speed of 8 m / min. Then, it is dried online at 100℃, forming an insulating encapsulation layer with a thickness of 20 μm. Finally, the luminescent fibers are collected and wound onto a spool. The resulting cross-sectional view of the luminescent fiber is shown below. Figure 3 As shown.

[0096] The core fiber electrode and the outer conductive layer are peeled off from one end of the prepared luminescent fiber. A driving device with an AC voltage of 80V and a driving frequency of 1000Hz is used to connect the core fiber electrode and the outer conductive layer. The outer conductive layer is peeled off from the other end of the luminescent fiber, and a power supply with a DC voltage adjustment range of 0-10V is used to connect the two ends of the outer conductive layer. The high-voltage AC driving device is turned on, and the color-changing effect is achieved by adjusting the voltage of the DC power supply.

[0097] Example 3

[0098] Step 1: At room temperature (25℃), add 50g of ZnS:Cu luminescent powder (average particle size 25μm, national standard grade D502, Shanghai Keyan Optoelectronic Technology Co., Ltd.) to 30g of water, then add 19.5g of polyurethane binder (Shenzhen Yoshida Chemical Co., Ltd.) and 0.5g of sodium dodecylbenzenesulfonate. Stir magnetically for 30 minutes at a stirring speed of 300rpm to obtain a uniformly dispersed electroluminescent slurry. Add 20g of thermoluminescent material C to 30g of water, then add 19.5g of polyurethane binder and 0.5g of sodium dodecylbenzenesulfonate. Stir magnetically for 30 minutes at a stirring speed of 300rpm to obtain a uniformly dispersed thermochromic slurry.

[0099] Step 2: Turn on the dip-coating device and uniformly coat the prepared electroluminescent paste onto the surface of the core fiber electrode copper wire nylon core-spun conductive yarn (diameter 210μm, Laiwu Longzhi Metal Yarn Co., Ltd.) at a speed of 10m / min. After drying at 120℃, it is finally collected on a roller. The thickness of the electroluminescent active layer is 40μm.

[0100] Step 3: Turn on the twisting device, and then incorporate the copper wire fiber (30μm in diameter) into the fiber by winding it, so as to form an outer electrode conductive layer together with the conductive coating. The thickness of the outer electrode conductive layer is 30μm.

[0101] Step 4: Turn on the dip coating device again and uniformly coat the prepared thermochromic slurry onto the surface of the core fiber electrode copper wire composite fiber material (diameter 100μm) at a speed of 10m / min. After drying at 120℃, it is finally collected on a roller. The thickness of the thermochromic active layer is 20μm.

[0102] Step 5: The encapsulation device is activated, and a 50wt% aqueous acrylic resin emulsion (product model E0512, Shenzhen Yoshida Chemical Co., Ltd.) is uniformly coated onto the fiber surface at a speed of 8 m / min. The fiber is then dried online at 100℃, forming an insulating encapsulation layer with a thickness of 40 μm. Finally, the luminescent fibers are collected and wound onto a spool. The resulting cross-sectional view of the luminescent fiber is shown below. Figure 4 As shown.

[0103] The core fiber electrode and the outer conductive layer are peeled off from one end of the prepared luminescent fiber. A driving device with an AC voltage of 80V and a driving frequency of 1000Hz is used to connect the core fiber electrode and the outer conductive layer. The outer conductive layer is peeled off from the other end of the luminescent fiber, and a power supply with a DC voltage adjustment range of 0-10V is used to connect the two ends of the outer conductive layer. The high-voltage AC driving device is turned on, and the color-changing effect is achieved by adjusting the voltage of the DC power supply.

[0104] Example 4

[0105] Step 1: At room temperature (25℃), add 40g of CaGa2S4 luminescent powder to 60g of water, then add 29.4g of polyacrylate binder (Shenzhen Yoshida Chemical Co., Ltd.) and 0.6g of Tween 80. Stir magnetically for 30 minutes at a stirring speed of 300 rpm to obtain a uniformly dispersed electroluminescent slurry. Add 20g of thermoluminescent material A to 50g of water, then add 29.5g of polyacrylate binder and 0.5g of Tween 80. Stir magnetically for 30 minutes at a stirring speed of 300 rpm to obtain a uniformly dispersed thermochromic slurry.

[0106] Step 2: Turn on the dip-coating device and uniformly coat the prepared electroluminescent paste onto the surface of the conductive fibers (100μm, model T700SC-12000-50C) of the core fiber electrode carbon material at a speed of 10m / min. After drying at 100℃, the paste is finally collected on a roller. The thickness of the electroluminescent active layer is 20μm.

[0107] Step 3: Turn on the twisting device and incorporate the silver-plated yarn (75D fineness, Shenzhen Teli Chemical Fiber Co., Ltd.) into the fiber by winding to form an outer electrode conductive layer with a thickness of 30μm.

[0108] Step 4: The dip-coating device is then turned on, and the prepared thermochromic slurry is uniformly coated onto the surface of the core fiber electrode at a speed of 10 m / min. After drying at 100°C, it is finally collected on a roller. The thickness of the thermochromic active layer is 10 μm.

[0109] Step 5: Turn on the encapsulation device and uniformly coat the fiber surface with 50wt% water-based fluorocarbon emulsion (product model E0802, Shenzhen Yoshida Chemical Co., Ltd.) at a speed of 8m / min. Then dry it online at 100℃. The resulting insulating encapsulation layer is 10μm thick. Finally, collect the luminescent fibers and wind them onto the spool.

[0110] The core fiber electrode and the outer conductive layer are peeled off from one end of the prepared luminescent fiber. A driving device with an AC voltage of 80V and a driving frequency of 1000Hz is used to connect the core fiber electrode and the outer conductive layer. The outer conductive layer is peeled off from the other end of the luminescent fiber, and a power supply with a DC voltage adjustment range of 0-10V is used to connect the two ends of the outer conductive layer. The high-voltage AC driving device is turned on, and the color-changing effect is achieved by adjusting the voltage of the DC power supply.

[0111] Example 5

[0112] Step 1: At room temperature (25℃), add 80g of CaN luminescent powder to 17.5g of ethanol, then add 20g of vinyl acetate binder (Nanjing Qinhai Trading Co., Ltd.) and 0.5g of sodium dodecyl sulfate. Stir magnetically for 30 minutes at a stirring speed of 300 rpm to obtain a uniformly dispersed electroluminescent slurry. Add 50g of thermoluminescent material A to 47g of ethanol, then add 25g of vinyl acetate binder and 0.5g of sodium dodecyl sulfate. Stir magnetically for 30 minutes at a stirring speed of 300 rpm to obtain a uniformly dispersed thermochromic slurry.

[0113] Step 2: Turn on the dip-coating device and uniformly coat the prepared electroluminescent paste onto the surface of the core fiber electrode copper wire nylon core-spun conductive yarn (diameter 210μm, Laiwu Longzhi Metal Yarn Co., Ltd.) at a speed of 10m / min. After drying at 60℃, it is finally collected on a roller. The thickness of the electroluminescent active layer is 80μm.

[0114] Step 3: Turn on the twisting device and incorporate the copper-plated yarn (fineness specification 20D / 3F, Shanghai Pusheng Gold and Silver Wire Textile Co., Ltd.) into the fiber by winding to form an outer electrode conductive layer with a thickness of 25μm.

[0115] Step 4: The dip-coating device is then turned on, and the prepared thermochromic slurry is uniformly coated onto the surface of the core fiber electrode at a speed of 10 m / min. After drying at 100°C, it is finally collected on a roller. The thickness of the thermochromic active layer is 25 μm.

[0116] Step 5: Turn on the encapsulation device and uniformly coat the fiber surface with 50wt% water-based acrylic resin emulsion (product model E0512, Shenzhen Yoshida Chemical Co., Ltd.) at a speed of 8m / min. Then dry it online at 100℃. The resulting insulating encapsulation layer is 30μm thick. Finally, collect the luminescent fibers and wind them onto the spool.

[0117] The core fiber electrode and the outer conductive layer are peeled off from one end of the prepared luminescent fiber. A driving device with an AC voltage of 80V and a driving frequency of 1000Hz is used to connect the core fiber electrode and the outer conductive layer. The outer conductive layer is peeled off from the other end of the luminescent fiber, and a power supply with a DC voltage adjustment range of 0-10V is used to connect the two ends of the outer conductive layer. The high-voltage AC driving device is turned on, and the color-changing effect is achieved by adjusting the voltage of the DC power supply.

[0118] Comparative Example 1

[0119] The luminescent fibers were prepared using the same method as in Example 3, except that the thickness of the thermochromic active layer in Comparative Example 1 was 50 μm. (Increasing the thickness of the thermochromic active layer does not conform to the rule: the thickness of the thermochromic active layer is (H±5) μm, where H=0.3h+5).

[0120] Comparative Example 2

[0121] The luminescent fibers were prepared using the same method as in Example 3, except that the thickness of the electroluminescent active layer in Comparative Example 2 was 100 μm. (This increases the thickness of the thermochromic active layer, which does not conform to the rule that the thickness of the thermochromic active layer is (H±5) μm, where H=0.3h+5).

[0122] Comparative Example 3

[0123] The luminescent fibers were prepared using the same method as in Example 3, except that step 5 was not performed in Comparative Example 3, that is, the luminescent fibers prepared in Comparative Example 5 did not contain an insulating encapsulation layer.

[0124] Comparative Example 4

[0125] The luminescent fibers were prepared using the same method as in Example 1, except that in Comparative Example 4, the order of the thermochromic active layer and the electroluminescent active layer was reversed.

[0126] The color control results of the luminescent fibers prepared in the above embodiments and comparative examples are shown in Table 1 below.

[0127] Table 1 Color Adjustment Results

[0128]

[0129] The luminescence brightness and abrasion resistance of the luminescent fibers prepared in the above embodiments and comparative examples were tested.

[0130] Luminescence brightness test method: The prepared luminescent fibers are normally lit, and the results are measured using a CM-HYPn-I colorimeter; Abrasion resistance test method: The prepared luminescent fibers are sewn onto the surface of a leather base fabric, and the abrasion resistance is tested according to the national standard GBT21196.2-2007.

[0131] The performance test results are shown in Table 2 below.

[0132] Table 2

[0133]

[0134] As can be seen from the data in Table 1-2, the luminescent fibers prepared in Examples 1-5 have both excellent electroluminescence and color-changing properties, and are also highly durable with a long service life.

[0135] The performance data comparison between Comparative Examples 1-2 and Example 3 shows that if the thickness relationship between the thermochromic active layer and the electroluminescent active layer is not appropriate, the electroluminescence and color-changing properties of the luminescent fiber will deteriorate. This is because if the thickness of the thermochromic active layer is too large, the electroluminescence performance will be affected. If the thickness of the thermochromic active layer is too small, the electroluminescence performance will be high, but the color-changing performance will be insignificant. As a result, the luminescent fiber cannot simultaneously possess both electroluminescence and color-changing properties.

[0136] The performance data comparison between Comparative Example 3 and Example 3 shows that: with the presence of an insulating encapsulation layer, the wear resistance of the luminescent fiber can reach 3000 cycles without damage; without an insulating encapsulation layer, the luminescent color-changing layer of the luminescent fiber is damaged after 500 cycles, and the service life of the luminescent fiber will be greatly reduced.

[0137] A comparison of the performance data from Comparative Example 4 and Example 1 shows that if the order of the thermochromic active layer and the electroluminescent active layer is reversed, although the brightness of the luminescent fiber increases, it is almost impossible to exhibit color-changing properties. The luminescent fiber prepared using the method described in this invention can combine both electroluminescent and color-changing properties.

[0138] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. An electroluminescent and thermochromic color-tunable light emitting fiber, characterized in that, The luminescent fiber comprises at least two conductive layers, a luminescent color-changing layer and an insulating encapsulating layer, wherein the luminescent color-changing layer comprises two layers of electroluminescent active layer and thermochromic active layer; The luminescent color-changing layer is adjacent to the conductive layer, and the insulating encapsulating layer is the outermost layer of the luminescent fiber; The conductive layer comprises a core fiber electrode and an outer electrode conductive layer, and the core fiber electrode is the innermost layer of the luminescent fiber; The luminescent fiber comprises, from inside to outside, a core fiber electrode, an electroluminescent active layer, a thermochromic active layer, an outer electrode conductive layer and an insulating encapsulating layer; Alternatively, the luminescent fiber comprises, from inside to outside, a core fiber electrode, an electroluminescent active layer, an outer electrode conductive layer, a thermochromic active layer and an insulating encapsulating layer; The thickness of the electroluminescent active layer is 20-150 μm; The thickness of the thermochromic active layer is 10-50 μm; The thermochromic material used in the thermochromic active layer is a thermochromic material in a microcapsule structure.

2. The electrochromic and thermochromic color-tunable light-emitting fiber according to claim 1, characterized in that The core layer fiber electrode is any one or several of metal conductive fiber, metal composite fiber, and carbon material fiber; the diameter of the core layer fiber electrode is 100-300 μm, and the conductivity is 10 -2 -10 2 S / cm; The outer electrode conductive layer is any one or several of silver nanowires, an adhesive containing metal particles, metal wires, chemical fibers containing metal particles and carbon nanofibers.

3. A method for preparing the electroluminescent and thermochromic color-tunable luminescent fiber according to any one of claims 1-2, characterized in that, The preparation method is as follows: S1, preparation of electroluminescent paste and thermochromic paste: mixing electroluminescent material, solvent, polymer binder and dispersant to obtain electroluminescent paste; mixing thermochromic material, solvent, polymer binder and dispersant to obtain thermochromic paste; S2, construction of luminescent color-changing layer and outer electrode conductive layer: coating the electroluminescent paste and the thermochromic paste on the outer surface of the core fiber electrode in turn, and then drying to obtain the luminescent color-changing layer, and then loading the outer electrode conductive layer material on the outer surface of the luminescent color-changing layer; Alternatively, coating the electroluminescent paste on the outer surface of the core fiber electrode, and then drying to obtain the electroluminescent active layer, and then loading the outer electrode conductive layer material on the outer surface of the thermochromic active layer to form the outer electrode conductive layer, and then coating the thermochromic paste on the outer surface of the outer electrode conductive layer, and then drying to obtain the thermochromic active layer; S3, construction of insulating encapsulating layer: using an insulating transparent polymer for encapsulation, and then drying and winding to obtain the electroluminescent and thermochromic color-adjustable luminescent fiber.

4. The method for preparing an electroluminescent and thermochromic tunable luminescent fiber according to claim 3, characterized in that, The electroluminescent material is one or several of SiO2-based luminescent powder, metal sulfide type luminescent powder, GaN or Zn2SiO4; the particle size of the electroluminescent material is 5-40 μm, and the mass content of the electroluminescent material in the electroluminescent paste is 10-80 wt%; The mass content of the thermochromic material in the thermochromic paste is 10-30 wt%.

5. The method for preparing an electroluminescent and thermochromic tunable luminescent fiber according to claim 3, characterized in that, The polymer is any one or several of polyvinyl alcohol, polyurethane, vinyl acetate, acrylic, epoxy resin binder, phenolic resin binder and silicone resin binder; the mass content of the polymer in the electroluminescent paste or the thermochromic paste is 1-50 wt%. The dispersant is any one or several of aqueous siloxane, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, Tween 80, cetyl trimethyl ammonium chloride, and the mass content of the dispersant in the electroluminescent paste or thermochromic paste is 0.5-1wt%; The solvent is any one or several of water, ethanol, acetone or N-methyl pyrrolidone.

6. The method for preparing an electroluminescent and thermochromic tunable luminescent fiber according to claim 3, characterized in that, The insulating transparent polymer is any one or several of epoxy resin, acrylate resin, polyurethane resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin or silicone resin.

7. The method for preparing an electroluminescent and thermochromic tunable luminescent fiber according to claim 3, characterized in that, The thickness of the outer electrode conductive layer is 5-50μm. The thickness of the insulating encapsulation layer is 10-80μm.

8. The method for preparing an electroluminescent and thermochromic tunable luminescent fiber according to claim 3, characterized in that, The drying temperature is 60-180℃, and the drying time is 5-15s.

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