Application of energy storage type luminous paint

Luminescent coatings can be divided into fluorescent coatings, self-illuminating coatings, energy storage type luminescent coatings three categories.
fluorescent paint refers to the ultraviolet radiation can emit fluorescent paint, after stopping the exposure is completely non-luminescent;
the luminescence of fluorescent lamps (fluorescent lamps)
On April 1, 1938, General Motors of the United States invented fluorescent lamps. This fluorescent lamp is a glass tube filled with a certain amount of mercury, the inner wall of the tube has phosphor

. There is a wire at each end of the tube to make an electrode. When powered on, the first is the release of mercury vapor, while producing ultraviolet light, which excites fluorescent material from the inner wall of the tube and emits visible light. Because this composition is similar to daylight, fluorescent lamps are also known as fluorescent lamps.
self-illuminating coating is a coating that does not require external energy to stimulate sustainable luminescence, adding luminous pigments containing radioactive material to continuously glow the paint using the energy generated by radioactive material.
-storage type luminescent powder
energy storage type luminescent coating refers to the sun or light can absorb and store light energy, in the absence of light exposure, by releasing stored energy and emit special fluorescent paint, this coating contains a luminous pigment non-radioactive, safe and stable luminescence properties, is the main direction of the development of luminous paint.
of energy storage type luminescent coatings
luminescent coatings are composed of film-forming substances, luminescent pigments and additives, such as functional coatings.
1. 1 film-forming substance
According to its luminous properties and application environment, the film-forming substances used in energy storage-type luminescent coatings should have the following characteristics: colorless transparent and good light transmission, especially for UV transmission, high solid content, good water resistance, strong adhesion, acid-base, solvent-resistant performance, weather resistance, good impact resistance.
acrylic resin, silicone modified acrylic resin, polyurethane resin, epoxy resin, aortic resin, fluorine resin, etc. can be used as a film-forming substance of this type of coating. Acrylic resin on the main absorption peak of light outside the solar spectrum, colorless transparent, high ultraviolet through rate, so it has excellent light resistance and outdoor aging.
Polyurethane resin main chain contains a strong polar amino acid group, easy to form hydrogen bonds between large molecules, can form with high strength, wear resistance, solvent resistance, high and low temperature performance is good, strong adhesion of the paint film. And polyurethane resin and other resins mix well, can be used with a variety of resins, preparation of different requirements of new varieties of coatings.
1. 2 Luminescent Pigments
Luminescent pigments are usually referred to as luminescent pigments, also known as long afterglow luminescent pigments, are the main substances that make coatings glow. The afterglow brightness, afterglow length and luminescence color of the energy storage type light-emitting coating mainly depend on the luminous pigment.
luminescent pigments are divided into two main categories: inorganic luminescent pigments and organic luminescent pigments.
, inorganic luminescent pigments are mainly composed of three categories: zinc sulfide luminescent pigments, rare earth-activated alkali-based metal bauxite luminescent pigments and rare earth doped silicate luminescent pigments.
zinc sulfide luminescent powder
zinc sulfide luminescent pigment chemical properties are unstable, in a certain amount of humidity and ultraviolet radiation will occur decomposition gradually decay fade black, and the luminescence time is short. To overcome these shortcomings, a small amount of radioactive material such as radon, Co, Pm, etc. needs to be added to this pigment as an activator, but the added radioactive material can cause harm to the human body and the environment, thus greatly limiting the use of zinc sulfide luminescent pigments.
Rare earth doped silicate luminescent pigments have good chemical stability and thermal stability, strong water resistance, a wide range of luminescent colors, and high purity SiO2 raw materials are inexpensive and easy to access, has long been a hot spot for research and development. However, the luminescence performance of rare earth doped silicate system, especially the luminous brightness and afterglow time has not yet reached the level of aluminumate system, and most of the results are still in the laboratory research stage, to make it to practical application, still need more efforts and exploration.
rare earth activated alkali metal bauxite system luminescent pigment refers to rare earths, especially eu as the activation element, alkaline metal bauxate as the base of the luminous pigment. This type of luminescent pigment has the following advantages: high luminous efficiency, long afterglow time, excellent chemical stability, non-radioactive, acid, alkali, weather, radiation, antioxidant and UV resistance, long life of the material, can be used in air and some special environment for a long time. It is precisely because the chemical properties of these materials are stable that they become the main pigments for the preparation of luminous coatings. However, aluminumate series luminescent pigments in the physical and chemical properties have their own shortcomings, such as aluminumate in the water environment easy to break down, water resistance, low high temperature resistance, and poor compatible with organic systems, so it is necessary to make surface changes to such luminescent pigments.
variety of organic luminescent pigments, good adjustability, rich color, high color purity, but the weather resistance and chemical resistance is generally poor, so its application areas have been greatly limited. Inororal luminescent pigments have good weather resistance, chemical resistance, and high luminescence strength, long afterglow time, making it the first choice for energy storage-type luminescent coatings.
1. 3 Additives
energy-storage luminescent coatings include leveling agents, thickeners, surfactants, pigment dispersants, dryers, stabilizers, and fillers. Light-emitting pigments have poor light resistance and easy to powder, in order to extend their service life, it is often necessary to add high-performance light stabilizers to the formulation; Add pigment dispersants, thickeners and anti-precipitation agents such as gas phase silica to help disperse luminous pigments; A small amount of talcum powder or titanium white powder as an auxiliary pigment can not only reduce the cost of the coating, but also enhance the luminous properties of the coating.
2 preparation of energy storage type luminescent coatings
preparation of energy storage type luminescent coatings commonly used methods are mixed method, in-place polylex legal and powder coating method. Among them, the co-mixing method is the most common method of preparing energy storage type luminous coating, mainly through high-speed grinding stirring, the luminous pigment is evenly distributed in the film-forming material under the effect of additives, to obtain excellent performance of energy storage type luminescent coating. The general water-based luminescent coating preparation process is as follows: First, deionized water, thickener added to the high-speed dispersion kettle, and then added fillers such as talcum powder, titanium dioxide, etc., continue to stir at high speed, to achieve the required fineness; Add emulsion and film-forming additives under the condition of medium-speed stirring; Then add luminescent pigments, anti-sinking agents and other additives; Adjust the viscosity and pH of the coating, i.e. water-based energy storage type luminescent coating. 3 The structure and performance of the energy storage type luminescent coating
the afterglow brightness of the energy storage type luminescent coating is related to the particle size of the luminescent pigment, if the particle size is too small, reaching the nanoscale, due to the effect of small size, the luminescence intensity of the coating will be reduced, or even not glow; The particle size of the luminescent pigments generally selected is between 20 and 40 m.
The larger the particle size of the night light powder, the higher the initial brightness after the absorption of light, the longer the afterglow time, but the particle size is too large night powder in the preparation of the paint is also easier to precipitate, at the same time, will also make the paint surface too rough. In contrast, the particle size is too small night light powder in the paint dispersion is better and not easy to precipitate, prepared into a coating after its surface is more smooth, but the particle size is too small night light powder, whether after the initial brightness or afterglow time is not as good as the large particle size night light powder. Reasonable selection of the particle size of night light powder is particularly important for the preparation of night light coating.
brightness and afterglow time of energy storage-type luminescent coatings are also related to the amount of addition, coating thickness and light source of luminous pigments. The afterglow brightness of the luminous paint increases with the increase of the amount of luminous pigment, but when the content of the luminous pigment is higher than 50%, the increase of afterglow strength is no longer obvious, and the performance of the coating is worse. The afterglow brightness of the coating increases with the increase of the thickness of the film layer, but it will reach saturation to a certain extent.
pigment particle size is large in the energy storage type luminescent coating, if not treated, it will sink rapidly in water or other solvents, and even gather in a clump. In response to this problem, scholars at home and abroad have carried out a lot of research, such as the use of titanium esters or silane coupled agent for hydrophobic powder hydrophosphation, can also be used with sodium tripophosphate as a dispersant, organic benthic soil as a sediment inhibitor, the night light coating has a good dispersion effect and anti-precipitation. The U.S. patent refers to silica, a denatured material, as a precipitant, which can improve the deposition of luminous pigments.
4 Application of energy storage-type luminescent coatings
energy storage type luminescent coatings non-toxic, harmless, non-radioactive, weather-resistant, light-resistant better, environmental protection, strong adsorption capacity, long-term use of non-coloring, good luminescence effect, so in architecture, textiles and other aspects of widespread application. Energy storage type luminescent coating has a special absorption, release, re-absorption, re-release of light energy, this cycle can be carried out countless times, this characteristic in people's daily life, industrial production and national defense construction can play an important role.
4. 1 Architectural decoration
the application of energy storage luminescent coatings in architectural decoration
energy storage luminescent coatings can absorb and store energy after exposure to light, when the emergency power supply is cut off, the part coated with energy-absorbing luminescent coatings can glow in the dark, leading to the safe evacuation of trapped people, so the coating can be used for public places safe passages, safety doors and other indicators.
4. 2 Road marking aspects
energy storage luminescent coatings in the day and night comparison
Jiangxi high-speed in the already running tunnels using rare earth light-storage luminescent coatings sprayed on the road surface, to make a glowing road surface, the use of light-emitting materials in a short period of time to absorb the light energy of moving vehicles, long-term diffuse fluorescence, light tunnel to achieve the purpose of safe driving. When used as a road sign, the energy-storage luminescent coating has excellent identifiability and can greatly improve the safety of pedestrians and vehicle users travelling at night.
4. 3 Fabric decoration
the application of energy storage luminescent coating in clothing
the special luminescence characteristics of energy storage luminescent coating can also be used in life jackets, fire clothing, evening clothing and other special clothing products, not only with lighting, safety warning function, but also play a decorative, beautifying effect. 5 problems and development trends
although energy storage type luminescent coatings have many excellent performance, but its application is still limited, especially in some large areas of the site, such as building interior and exterior wall coatings, flooring and other difficult to be promoted and used. The main reasons are as follows:
(1) from the economic level, energy storage type luminescent coating costs are high, difficult to promote the use of large areas;
(2) From the technical level, the comprehensive performance of energy storage-type luminescent coating is difficult to meet the requirements of the use of variable environment, especially weather resistance, impact resistance, scratch resistance performance is not strong;
(3) From the theoretical research level, most of the focus in this field is on the luminous intensity, afterglow time and durability of luminous pigments, which is still lacking in systematic basic theoretical research.
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