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CN-118421148-B - Black infrared transmission paint and preparation method and application thereof

CN118421148BCN 118421148 BCN118421148 BCN 118421148BCN-118421148-B

Abstract

The invention relates to the technical field of coatings, and discloses a black infrared transmission coating, a preparation method and application thereof. The black infrared transmission paint comprises a resin composition (comprising organic silicon modified acrylic resin and polyester resin), a black pigment and filler composition (comprising yellow pigment, blue pigment, red pigment, filler particles and solvent) and an isocyanate curing agent, wherein the organic silicon modified acrylic resin is formed by carrying out hydrolysis and condensation reaction on blocked isocyanate group trimethoxysilane (with self-blocked isocyanate groups) and vinyl triethoxysilane under the condition of a catalyst and water to form an organic silicon material containing olefin and silicon hydroxyl, and then carrying out cross-linking reaction on the organic silicon material and the acrylic resin under a free radical initiator. The coating can better wrap and fix pigment, has high infrared light transmittance, good heat-resistant stability and aging-resistant migration of the coating, has high infrared light reflectivity and long-term stability of the obtained infrared reflection photovoltaic backboard, and can ensure stable increase of power of the component for a long time.

Inventors

  • LIN JIANWEI
  • ZHANG FUTE
  • SUN HAILONG
  • LI JUNJUN
  • WANG ZHAN
  • CHENG XUDONG

Assignees

  • 苏州中来光伏新材股份有限公司

Dates

Publication Date
20260508
Application Date
20240428

Claims (9)

  1. 1. The black infrared transmission paint is characterized by comprising, by weight, 40-70 parts of a resin composition, 15-40 parts of a black pigment-filler composition and 2-15 parts of an isocyanate curing agent; Wherein the resin composition is formed by mixing 20-40 parts of organosilicon modified acrylic resin and 20-40 parts of polyester resin; the organosilicon modified acrylic resin is prepared by hydrolyzing 10-20 parts of blocked isocyanate group trimethoxy silane and 10-20 parts of vinyl triethoxy silane under the action of 0.1-2 parts of catalyst and 5-10 parts of water to form an organosilicon material containing olefin and silicon hydroxyl, and then crosslinking with 50-80 parts of acrylic resin under the action of 0.1-5 parts of free radical initiator; The blocked isocyanate group trimethoxysilane has self-blocked isocyanate groups, and can release the isocyanate groups again when heated to more than 120 ℃; wherein the pigment-filler composition comprises 3-20 parts of yellow pigment, 25-40 parts of blue pigment, 35-60 parts of red pigment, 15-25 parts of filler particles and 70-90 parts of solvent.
  2. 2. A black infrared transmitting paint according to claim 1, wherein said blocked isocyanate group trimethoxysilane is formed by blocking reaction of 3-isocyanate group propyltrimethoxysilane with 3, 5-dimethylpyrazole through isocyanate group.
  3. 3. The black infrared transmitting paint according to claim 1, wherein said acrylic resin is a low molecular weight acrylic resin having a molecular weight of 3000-5000, and said catalyst is acetic acid or hydrochloric acid.
  4. 4. The black infrared transmission coating according to claim 1, wherein the filler particles are silica coating with a core-shell structure, the inner core is silica, and the outer layer is organic material; The organic material is at least one of fatty alcohol and silane coupling agent.
  5. 5. A method for producing a black infrared transmitting paint according to any one of claims 1 to 4, comprising the steps of: step S1, synthesizing organic silicon modified acrylic resin: S11, adding 3-isocyanate group propyl trimethoxy silane and 3, 5-dimethylpyrazole according to a molar ratio of 1:1-1.2, stirring and mixing, and reacting for 25-35 minutes at 55-65 ℃ to obtain blocked isocyanate group trimethoxy silane; Step S12, uniformly mixing 50-80 parts of acrylic resin, 10-20 parts of blocked isocyanate group trimethoxy silane, 10-20 parts of vinyl triethoxy silane and 0.1-2 parts of catalyst, heating to 60-70 ℃, slowly dropwise adding 5-10 parts of water, continuously carrying out reflux reaction for at least 1h after dropwise adding, heating to 105-115 ℃, dropwise adding 0.1-5 parts of free radical initiator, and continuously carrying out reaction for at least 2h to obtain the organosilicon modified acrylic resin; Step S2, uniformly mixing and stirring the polyester resin and the organosilicon modified acrylic resin according to the formula amount to obtain a resin composition; s3, adding the formula amount of yellow pigment, blue pigment, red pigment and filler particles into a solvent, grinding uniformly, and filtering to obtain a black pigment-filler composition; And S4, mixing the resin composition, the pigment and filler composition and the isocyanate curing agent according to the formula amount, fully stirring and uniformly mixing, and filtering to obtain the black infrared transmission coating.
  6. 6. The method for preparing the black infrared transmission coating according to claim 5, wherein the step S11 is to add 3-isocyanate group propyl trimethoxysilane and 3, 5-dimethylpyrazole in a molar ratio of 1:1, stir and mix, and react for 30 minutes at 60 ℃ to prepare the blocked isocyanate group trimethoxysilane.
  7. 7. The method for preparing the black infrared transmission coating according to claim 5, wherein the step S12 is characterized in that 60 parts of acrylic resin, 15 parts of closed isocyanate group trimethoxysilane, 10 parts of vinyl triethoxysilane and 0.2 part of acetic acid are uniformly mixed, then the temperature is raised to 65 ℃,8 parts of water is slowly added dropwise, the dropwise addition is carried out for 30min, after the dropwise addition is completed, the reflux reaction is continued for 1h, the temperature is raised to 110 ℃,2 parts of azobisisobutyronitrile is added dropwise, and the reaction is continued for 2h, so that the organosilicon modified acrylic resin is obtained.
  8. 8. Use of a black infrared transmitting coating according to any of claims 1-4, wherein the black infrared transmitting coating is applied to the preparation of an infrared reflecting photovoltaic backsheet, which is applied as follows: And (3) coating the black infrared transmission coating on one surface of the white substrate, which is close to the battery piece, and curing to form the black infrared transmission coating on the surface of the white substrate.
  9. 9. The application of the black infrared transmission coating according to claim 8, wherein the white substrate comprises a photovoltaic substrate and a weather-resistant coating layer positioned on the other surface of the photovoltaic substrate far away from the battery piece, wherein the photovoltaic substrate and/or the weather-resistant coating layer is a white reflecting layer; The photovoltaic substrate is a semi-transparent or super-white polyester film with the thickness of 275-325 mu m, and the weather-resistant coating is a white weather-resistant coating or a black weather-resistant coating with the thickness of 8-10 mu m; the thickness of the black infrared transmitting coating is 6-20 mu m.

Description

Black infrared transmission paint and preparation method and application thereof Technical Field The invention relates to the technical field of coatings, in particular to a black infrared transmission coating and a preparation method and application thereof. Background Solar photovoltaic modules (photovoltaic modules for short) are used as an environment-friendly clean energy source, and have been widely popularized in recent years. Some photovoltaic modules built on industrial roofs and commercial building roofs often have requirements for attractive appearance and light pollution prevention, so black photovoltaic modules are generally adopted. In general, for a photovoltaic module with 60 cells, the spacing between the cell gaps is generally 2mm4mm, so that the area uncovered by the cells accounts for more than 2% of the total area of the photovoltaic module, that is, more than 2% of sunlight is transmitted through the cell gaps, and does not reach the cell surfaces to be absorbed and utilized by the cells. Moreover, the black photovoltaic module manufactured by the conventional black photovoltaic backboard has strong absorption to all-band light, the absorption to most of infrared light bands by the conventional black photovoltaic backboard can be directly converted into heat energy, the temperature of the photovoltaic module is increased, and the power generation efficiency of the photovoltaic module is reduced by about 0.4% when the temperature of the photovoltaic module is increased by 1 ℃. Therefore, 2% of sunlight which is transmitted through the cell gaps of the black photovoltaic module and is not utilized is easily absorbed and converted into heat energy by the conventional black photovoltaic back plate, so that the temperature of the photovoltaic module is increased to further reduce the power generation efficiency. Therefore, if the 2% sunlight can be fully utilized, the improvement of the power generation efficiency of the photovoltaic module is facilitated. Therefore, in the prior art, as shown in CN115926545A, weather-resistant black paint with infrared transmission performance can be matched with a base material with an infrared reflection function to obtain a photovoltaic backboard with a reflection function on an infrared light wave band, so that the working temperature of the photovoltaic module can be reduced, the absorption and utilization of a battery piece on reflected light can be improved, and the power generation efficiency of the photovoltaic module is improved. However, the prior photovoltaic backboard (CN 115926545A) with the reflection function on the infrared light wave band has the defects that the transmissivity of the used weather-resistant black coating in the infrared light wave band (750-1100 nm) needs to be improved, the wrapping and fixing performance of the weather-resistant black coating on the three-color pigment is poor, and the heat resistance stability and the ageing resistance migration performance of the weather-resistant black coating are poor in the long-term use process of the outdoor complex severe environment, so that the infrared reflectivity of the prior photovoltaic backboard is low, the long-term stability of the infrared reflectivity is poor, and the long-term stable growth of the power of a photovoltaic module is not facilitated. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a black infrared transmission coating, and a preparation method and application thereof. Based on the above, the invention discloses a black infrared transmission coating which comprises, by weight, 40-70 parts of a resin composition, 15-40 parts of a black pigment-filler composition and 2-15 parts of an isocyanate curing agent. Wherein the resin composition is formed by mixing 20-40 parts of organosilicon modified acrylic resin and 20-40 parts of polyester resin. The organosilicon modified acrylic resin is formed by hydrolyzing 10-20 parts of blocked isocyanate group trimethoxy silane and 10-20 parts of vinyl triethoxy silane under the action of 0.1-2 parts of catalyst (such as acetic acid or hydrochloric acid) and 5-10 parts of water to form an organosilicon material containing olefin and silicon hydroxyl, and then crosslinking 50-80 parts of the organosilicon modified acrylic resin with 50-80 parts of acrylic resin under the action of a free radical initiator (such as azodiisobutyronitrile). Preferably, the acrylic resin is a low molecular weight acrylic resin having a molecular weight of 3000 to 5000. Blocked isocyanate groups trimethoxysilane has self-blocked isocyanate groups. Preferably, the blocked isocyanate group trimethoxysilane is formed by the blocking reaction of 3-isocyanato propyl trimethoxysilane with 3, 5-dimethylpyrazole via isocyanate groups, and the blocked isocyanate group trimethoxysilane is heated to above 120 ℃ to re-release the isocyanate groups for self-polymerization. The synthetic principle of the o