Self-luminescent silicon rubber composition

Abstract

The present invention relates to a self-luminous silicone rubber composition, a method for manufacturing the same, and uses thereof.

Description

Technology Field

[0001] The present invention relates to a self-luminous silicone rubber composition, a method for manufacturing the same, and uses thereof. Background Technology

[0003] As the concentration of the population in large cities accelerates, traffic congestion caused by automobiles and climate change resulting from carbon dioxide emissions are becoming serious issues. Recently, Urban Air Mobility (UAM) has been attracting attention as a solution to address these problems. UAM is a new transportation system that utilizes low-altitude airspace (300–600m) to alleviate traffic congestion in metropolitan areas and ensure rapid transportation. It is an air transport system that safely and conveniently transports people and cargo within urban areas using eco-friendly electric Vertical Take-Off & Landing (eVTOL) aircraft and vertiports, and it is an environmentally friendly mode of transportation that emits no carbon.

[0004] Since automobiles, which are currently a common means of transportation, as well as the aforementioned UAM, a future mode of transport, inevitably involve vibrations caused by engine operation, there are efforts to convert this into electrical energy for utilization.

[0005] Meanwhile, as interest in health grows, the number of people enjoying outdoor exercise in the early morning or at night is increasing; however, engaging in activities in dark environments poses a risk of accidents. Therefore, providing light-emitting devices is of great help in ensuring their safety. However, providing separate lighting is cumbersome. Accordingly, there is a need to discover clothing or devices capable of emitting light using the energy from their activities. Prior art literature

[0007] Korean Registered Patent No. 10-2480363 The problem to be solved

[0008] One objective of the present invention is to provide a piezoelectric luminescent silicone rubber composition comprising, as a matrix, silicone rubber; as piezoelectric materials, one or more materials selected from the group consisting of polyvinylidene fluoride (PVDF), barium titanate (BaTiO3), and zinc oxide (ZnO); and as luminescent particles, one or more materials selected from the group consisting of quantum dots, zinc sulfide (ZnS), perovskite nanocrystals, silicon nanoparticles, and metal-organic frameworks (MOF), wherein the matrix, piezoelectric materials, and luminescent particles are each included in an amount of 70 to 80 wt%, 5 to 15 wt%, and 1 to 5 wt%, respectively, based on the weight of the total composition.

[0009] Another objective of the present invention is to provide a method for manufacturing a self-luminous silicone rubber product, comprising: a first step of uniformly mixing a piezoelectric material into a silicone rubber base and then additionally mixing in luminescent particles; a second step of uniformly dispersing the mixture and vacuum degassing; and a third step of molding and crosslinking the composition.

[0010] Another objective of the present invention is to provide a wearable device comprising a component made of the piezoelectric light-emitting silicone rubber composition. means of solving the problem

[0012] Each description and embodiment disclosed in the present invention may be applied to each other description and embodiment. That is, all combinations of the various elements disclosed in the present invention fall within the scope of the present invention. Furthermore, the scope of the present invention is not to be limited by the specific descriptions provided below.

[0013] Furthermore, a person skilled in the art can recognize or identify a number of equivalents to the specific embodiments of the present invention described in this invention using only ordinary experiments. In addition, such equivalents are intended to be included in the present invention.

[0014] Furthermore, throughout the specification of the present invention, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0016] The present invention will be described in more detail below.

[0018] As one embodiment for achieving the above objective, the present invention comprises, as a matrix, silicon rubber; and as piezoelectric materials, one or more materials selected from the group consisting of polyvinylidene fluoride (PVDF), barium titanate (BaTiO3), and zinc oxide (ZnO); The present invention provides a piezoelectric luminescent silicone rubber composition comprising one or more materials selected from the group consisting of quantum dots, zinc sulfide (ZnS), perovskite nanocrystals, silicon nanoparticles, and metal-organic frameworks (MOFs) as luminescent particles, wherein the substrate, the piezoelectric material, and the luminescent particles are each included in an amount of 70 to 80 wt%, 5 to 15 wt%, and 1 to 5 wt%, respectively, based on the weight of the total composition.

[0020] The term "silicon rubber" in this invention refers to an elastomer composed of silicone as a self-polymer containing silicone along with carbon, hydrogen, and oxygen. This silicone rubber is formed by the condensation of dimethylsilanediol, and the precise term for this is polysiloxane, which exhibits a saturated Si-O backbone. This silicone rubber is widely used throughout industry in various formulations. Since silicone rubber is generally non-reactive, stable, and resistant to extreme environments, it can maintain useful properties over a temperature range of -55°C to 300°C. Due to these characteristics and the ease of manufacturing and molding, silicone rubber is applied to a wide range of products, from automotive parts / accessories including voltage line insulators, sportswear, footwear, electronics, and medical devices to cooking, baking, and food storage products. For example, the silicone rubber used as a base material in the composition of this invention is a material with excellent flexibility and / or heat resistance, providing the inherent physical properties of rubber products.

[0021] The term "piezoelectric materials" in this invention refers to materials capable of directly converting vibrational (elastic) energy into electrical energy. In other words, the piezoelectric materials serve to convert mechanical vibrations into electrical energy. Most materials existing in nature are electrically neutral, consisting of positively charged particles, such as protons in atomic nuclei, and negatively charged particles (typically electrons) arranged in a regular pattern. However, if pressure is generated in a very narrow space and the positions of positive and negative charges become slightly misaligned, a difference in the energy intensity of the charges arises depending on the positions of the particles, thereby creating a very minute electric field. This is called the "electric dipole" phenomenon. By utilizing this principle, if the atoms of a specific material form a specific arrangement, this phenomenon can be made to occur easily even with a small force. For example, the composition of this invention may include PVDF, BaTiO3, and ZnO as piezoelectric materials, either individually or in combination of two or more. The aforementioned PVDF is a material with excellent flexibility, BaTiO3 is a material with a high piezoelectric coefficient, and ZnO is an excellent material that can be produced into various forms of nanoparticles by solid-vapor phase thermal sublimation technology and exhibits piezoelectric and pyroelectric properties. Therefore, considering the characteristics of each of the above materials, a suitable piezoelectric material can be selected and used according to the application and purpose of the final product to be produced.

[0022] The term "luminescent particles" in this invention refers to a material in the form of particles that absorbs energy and emits it in the form of light. In this invention, the luminescent particles convert the electrical energy generated by the piezoelectric material into light energy. At this time, the light generated within the rubber substrate can pass through the rubber substrate and be emitted to the outside; since the composition of this invention includes a silicone rubber with a bright white color as a substrate, it may be advantageous for such light emission. For example, the composition of this invention may include one or more materials selected from quantum dots, ZnS, perovskite nanocrystals, silicon nanoparticles, and MOFs as luminescent particles. These materials are all materials that possess the characteristic of emitting light in response to an electric field; the quantum dots have high luminescence efficiency and can realize various colors, ZnS can emit light efficiently, perovskite nanocrystals exhibit very high luminescence efficiency and have the characteristic of color tone control, silicon nanoparticles are environmentally friendly materials with high luminescence efficiency, and MOFs not only exhibit high luminescence efficiency but also possess the possibility and potential for various functionalizations.

[0024] The piezoelectric luminescent silicone rubber composition of the present invention is characterized by emitting light using vibration energy generated during the operation of automobiles and urban air mobility (UAM) or according to the movement of an object without an external energy supply. As previously mentioned, automobiles and UAMs inevitably involve vibration during operation, and moving objects also involve vibration. Therefore, the rubber composition of the present invention can be used in interior lighting systems or smart flooring equipped in automobiles or UAMs worn by objects, wearable devices worn by objects, sports equipment, or safety equipment used in various fields, and can exhibit self-luminescence by absorbing the generated vibrations and / or converting them into light energy.

[0026] for example , The piezoelectric material included in the rubber composition of the present invention may be included in the form of nanoparticles with a size of 100 to 500 nm. By being provided with such a size, a uniform and stable distribution within the silicone rubber can be achieved. Specifically, BaTiO3 may be used as particles with a size of 100 to 200 nm for high electrical output, and PVDF and / or ZnO may be used as particles with a size of 200 to 500 nm to maintain flexibility and / or dispersibility, but are not limited thereto.

[0027] For example, the luminescent particles included in the rubber composition of the present invention may be included in the form of nanoparticles with a size of 3 to 10 nm. By maintaining the particle size within the above range, the quantum confinement effect and surface area can operate most efficiently, thereby maximizing luminescence efficiency. On the other hand, if the particle size is smaller than the above range, surface defects increase, causing electron-hole recombination to occur inefficiently and reducing luminescence efficiency; and if the particle size is larger than the above range, the quantum confinement effect weakens, which may reduce luminescence efficiency.

[0028] For example, the piezoelectric luminescent silicone rubber composition of the present invention can exhibit a luminescence performance of 1 to 100 lm. This suggests that since the piezoelectric luminescent silicone rubber composition of the present invention can provide a minimum brightness (~1 lm) that can provide visual perception during nighttime activities, as well as sufficient brightness (~100 lm) required for vehicle interiors or wearable devices, it can be applied in a wide range of ways, from low-power display devices, wearable equipment, and night safety equipment that can be implemented even with low luminescence performance, to automotive interior lighting, displays, and environmental lighting that require high output.

[0030] For example, the rubber composition of the present invention may further include one or more selected from the group consisting of reinforcing agents, crosslinking agents, and other additives to achieve the physical / mechanical properties and / or functions required for each part.

[0031] For example, the above reinforcing agent may be added to improve strength and durability. As such a reinforcing agent, cellulose nanofiber (CNF) may be included in an amount of 2.5 to 10 wt% based on the weight of the total composition, but is not limited thereto.

[0032] For example, the above-mentioned crosslinking agent may be added to promote the crosslinking of rubber and improve physical properties. As such a crosslinking agent, a peroxide crosslinking agent may be included in an amount of 0.5 to 2 wt% based on the weight of the total composition, but is not limited thereto.

[0033] For example, the above other additives may be added to increase the flexibility of the rubber and / or improve its durability. Such other additives may include silicone oil and phenolic antioxidants in amounts of 1 to 5 wt% and 0.5 to 1 wt%, respectively, based on the weight of the total composition, but are not limited thereto.

[0035] In another aspect, the present invention provides a method for manufacturing a self-luminous silicone rubber product, comprising: a first step of uniformly mixing a piezoelectric material into a silicone rubber base and then additionally mixing in luminescent particles; a second step of uniformly dispersing the mixture and vacuum degassing; and a third step of molding and crosslinking the composition.

[0036] For example, the manufacturing method of the present invention may additionally include, but is not limited to, one or more processes selected from the group consisting of a step of heat treating the product, a step of surface treating, and a step of coating after the third step, as needed to impart desired physical properties to the final produced product. The durability and / or functionality of the product can be improved through the post-treatment.

[0037] In the manufacturing method of the present invention, each step may be performed using methods known in the art without limitation.

[0038] For example, the second step above may be performed using a high-speed mixer or an ultrasonic disperser for the uniform dispersion of each component and the complete removal of air from the mixed composition, but is not limited thereto.

[0040] In another aspect, the present invention provides a wearable device comprising a component made of the piezoelectric light-emitting silicone rubber composition.

[0041] For example, the piezoelectric luminescent silicone rubber composition of the present invention can be used in protective equipment such as luminescent athletic shoes and helmets, and accessories for bicycles and motorcycles, for the purpose of protecting users from nighttime exercise, driving, and dangerous work environments. Furthermore, it can be used in smart floors that emit light by detecting vibrations, interior lighting for autonomous vehicles, night sports equipment, and emergency lighting systems that emit light upon impact. Effects of the invention

[0043] The piezoelectric luminescent silicone rubber composition of the present invention includes piezoelectric materials and luminescent particles with optimized size and content, so that it can generate light without an external energy supply by utilizing vibrations generated from the movement of objects as well as vibrations generated during the operation of automobiles and urban air mobility, and thus can be usefully used for vehicle lighting or displays, wearable devices, clothing or safety equipment for nighttime exercise or work, etc. Brief explanation of the drawing

[0045] FIG. 1 is a diagram showing the operating principle of a self-luminous silicone rubber according to one embodiment of the present invention. FIG. 2 is a diagram showing a method for manufacturing a self-luminous silicone rubber product according to one embodiment of the present invention. Specific details for implementing the invention

[0046] The present invention will be explained in more detail below through examples. These examples are intended to explain the invention more specifically, and the scope of the invention is not limited by these examples.

[0048] Components

[0049] - silicone rubber (silicon rubber): As a material with excellent flexibility and heat resistance and a bright white color, it was selected to provide the basic physical properties of the product.

[0050] - piezoelectric material (piezoelectric materials): To convert mechanical vibrations into electrical energy, polyvinylidene fluoride (PVDF), barium titanate (BaTiO3), or a combination of both were used as piezoelectric materials.

[0051] - luminescent particles(luminescent particles): As a material for converting electrical energy generated by the above-mentioned piezoelectric material into light energy, one or more materials selected from the group consisting of quantum dots, zinc sulfide (ZnS), perovskite nanocrystals, silicon nanoparticles, and metal-organic frameworks (MOF) were used in the form of nanoparticles.

[0053] Example: Preparation of a self-luminous rubber composition

[0055] A self-luminous rubber composition suitable for each application was prepared by combining the above components in the amounts shown in Table 1 below.

[0056] Components Content (wt%) silicone rubber 70-80 piezoelectric material PVDF 5-15 BaTiO3 ZnO luminescent particles quantum dots 1-5 ZnS Perovskite nanocrystals silicon nanoparticles metal-organic framework Cellulose nanofiber (CNF) 2-10 Peroxide crosslinker 0.5-2 silicone oil 1-5 phenolic antioxidants 0.5-1

[0058] Preparation Example: Preparation of a standard composition

[0060] A self-luminous silicone rubber composition was prepared according to the specific compositional examples in Table 2 below.

[0061] rubber piezoelectric material luminescent particles reinforcing agent crosslinking agent Other additives Silicone rubber 80wt% BaTiO310wt% Perovskite nanocrystals 3wt% CNF2wt% Peroxide crosslinking agent 1 wt% Silicone oil 3wt% phenolic antioxidant 1wt%

[0063] Experimental Example 1: Luminescence performance data according to the content of piezoelectric material

[0065] Luminescence performance experiments were conducted using an electromechanical vibration generator, and the frequency of the applied stimulus was set from 0.5 Hz to 600 Hz using data reflecting actual vibration conditions in automotive and UAM environments. For example, the highest luminescence performance was observed at 100 Hz under vibration intensity conditions of 5 g, and measurements were taken while gradually increasing the vibration intensity from 1 g to 10 g. Vibration energy was delivered uniformly to the rubber sample, and luminescence performance was measured using a high-sensitivity photometer.

[0067] In order to verify the luminescence performance according to the content of the piezoelectric material in a silicone rubber composition comprising BaTiO3 as the piezoelectric material of the present invention and perovskite nanocrystals as luminescent particles, compositions containing 3 wt% perovskite nanocrystals and 5, 10, and 15 wt% of BaTiO3, respectively, were prepared, and the luminescence performance of each was measured and is shown in Table 3 below. Each composition was controlled based on the content of the reference composition in Table 2 above, by partially adjusting the content of silicone rubber and / or reinforcing agents, crosslinking agents, and other additives according to changes in the content of BaTiO3, while maintaining the total content constant.

[0068] BaTiO3 content (wt%) Perovskite nanocrystal content (wt%) Luminous performance (lm) 5 3 8.4-14.4 10 24-48 15 42-84

[0069] As shown in Table 3, it was found that luminescence performance increased as the content of the piezoelectric material increased, but at content exceeding the above, particle aggregation occurred, resulting in a decrease in actual luminescence performance. This suggests that it is necessary to control the content of the piezoelectric material at an appropriate level to obtain the desired performance.

[0071] Experimental Example 2: Luminescence performance data according to the content of luminescent particles

[0073] In order to verify the luminescence performance according to the content of luminescent particles in a silicone rubber composition comprising BaTiO3 as the piezoelectric material of the present invention and perovskite nanocrystals as luminescent particles, compositions containing 10 wt% BaTiO3 and 1, 3, and 5 wt% perovskite nanocrystals, respectively, were prepared, and the luminescence performance of each was measured and is shown in Table 4 below. Each composition was controlled by adjusting the content of silicone rubber and / or the content of reinforcing agents, crosslinking agents, and other additives according to the change in the content of perovskite nanocrystals, based on the content of the reference composition in Table 2 above, while maintaining the total content constant.

[0074] Perovskite nanocrystal content (wt%) BaTiO3 content (wt%) Luminous performance (lm) 1 10 18-36 3 24-48 5 27-54

[0075] As shown in Table 4, it was found that luminescence performance increased as the content of the contained luminescent particles increased, but at content exceeding the above, aggregation between particles occurred, resulting in a decrease in actual luminescence performance. This suggests that it is necessary to control the content of the luminescent particles at an appropriate level to obtain the desired performance.

[0077] Experimental Example 3: Luminescence Performance Data According to Combination of Piezoelectric Material and Luminescent Particles

[0079] As disclosed in Table 5 below, samples were prepared by changing the combination and content of various types of piezoelectric materials and light-emitting particles, and the light-emitting performance was measured and the results were presented together.

[0080] piezoelectric material luminescent particles Luminous performance (lm) ingredient Content (wt%) ingredient Content (wt%) PVDF 10 quantum dots 3 6-24 BaTiO3 10 Perovskite nanocrystals 3 24-48 ZnO 10 MOF 3 1.5-7 BaTiO3 12 ZnS 3 24-63 ZnO 8 Perovskite nanocrystals 4 14-28

[0081] As shown in Table 5, it was confirmed that various levels of luminescence performance were exhibited depending on the combination of the piezoelectric material and the luminescent particles. This suggests that the piezoelectric material and the luminescent particles can be combined and used according to the intended application and / or desired luminescence performance.

[0083] From the foregoing description, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. In this regard, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention should be interpreted as including all modifications or variations derived from the meaning and scope of the claims set forth below and their equivalents, rather than from the detailed description above.

Claims

Claim 1 A piezoelectric luminescent silicone rubber composition comprising: silicon rubber as a matrix; one or more materials selected from the group consisting of polyvinylidene fluoride (PVDF), barium titanate (BaTiO3), and zinc oxide (ZnO) as piezoelectric materials; and one or more materials selected from the group consisting of quantum dots, zinc sulfide (ZnS), perovskite nanocrystals, silicon nanoparticles, and metal-organic frameworks (MOF) as luminescent particles, wherein the matrix, piezoelectric material, and luminescent particles are each included in an amount of 70 to 80 wt%, 5 to 15 wt%, and 1 to 5 wt%, respectively, based on the weight of the total composition. Claim 2 A piezoelectric luminescent silicone rubber composition according to claim 1, which emits light using vibration energy without an external energy supply. Claim 3 A piezoelectric luminescent silicone rubber composition according to claim 1, wherein the piezoelectric material is included in the form of nanoparticles with a size of 100 to 500 nm. Claim 4 A piezoelectric luminescent silicone rubber composition according to claim 1, wherein the luminescent particles are included in the form of nanoparticles with a size of 3 to 10 nm. Claim 5 A piezoelectric luminescent silicone rubber composition according to claim 1, exhibiting a luminescence performance of 1 to 100 lm. Claim 6 A piezoelectric luminescent silicone rubber composition according to claim 1, further comprising one or more selected from the group consisting of reinforcing agents, crosslinking agents, and other additives. Claim 7 A piezoelectric luminescent silicone rubber composition according to claim 6, wherein the reinforcing agent comprises cellulose nanofiber (CNF) in an amount of 2.5 to 10 wt% based on the weight of the total composition. Claim 8 A piezoelectric luminescent silicone rubber composition according to claim 6, wherein the crosslinking agent comprises a peroxide crosslinking agent in an amount of 0.5 to 2 wt% based on the weight of the total composition. Claim 9 A piezoelectric luminescent silicone rubber composition according to claim 6, wherein the other additives include silicone oil and a phenolic antioxidant in amounts of 1 to 5 wt% and 0.5 to 1 wt%, respectively, based on the weight of the total composition. Claim 10 A method for manufacturing a self-luminous silicone rubber product, comprising: a first step of uniformly mixing a piezoelectric material into a silicone rubber base and then additionally mixing in luminescent particles; a second step of uniformly dispersing the mixture and vacuum degassing; and a third step of molding and crosslinking the composition. Claim 11 A manufacturing method according to claim 10, further comprising one or more processes selected from the group consisting of a step of heat treating the product, a step of surface treating, and a step of coating after the third step. Claim 12 A wearable device comprising a component made of a piezoelectric light-emitting silicone rubber composition according to any one of claims 1 to 9.

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