JP2024520095A - Flexible reflective material for increasing light capture rate of double-glazed solar panels and its preparation method and use - Google Patents

Abstract

[Problem] The present invention discloses a flexible reflective material for increasing the light receiving rate of double-glazed solar panels, and its preparation method and use. [Solution] The above preparation method mainly includes the steps of waterproofing, tenter setting, primer coating with PVC paste resin slurry, cover coating with PVC paste resin slurry, gelling, drying and plasticizing, gravure printing surface treatment with polyvinylidene fluoride three times, followed by embossing and cooling setting. The flexible reflective material provided by the present invention has high reflectivity, excellent weather resistance, and does not cause the temperature rise of the solar panel, and the flexible reflective material prepared by the present invention is flexible as a whole, easy to construct, install and maintain, and suitable for the requirements of installation and use in various scenes of solar cells. [Selected Figure] Figure 1

Description

The present invention belongs to the technical field of reflective materials, and specifically relates to a flexible reflective material for increasing the light receiving rate of double-glazed solar panels, and its preparation method and use.

In recent years, solar power generation technology has been developing rapidly. Double-glass solar panels are an important component of photovoltaic power generation systems and are usually made by combining a solar panel between two pieces of glass. Compared with solar panels with traditional backsheets, double-glass solar panels have excellent wear resistance, corrosion resistance and other properties, and enhanced weather resistance, making them suitable for implementation and use in extreme weather conditions.

A double-glazed solar panel cannot generate electricity without sunlight, but how to increase the light receiving rate of the double-glazed solar panel is directly related to the benefits of solar power generation. In the conventional technology, the diffuse reflectance of a polished and oxidized 99.5% pure aluminum plate only reaches about 0.50, while the white ceramic tile with better diffuse reflectance is about 0.55. The aluminum plate and ceramic tile are relatively hard and have very limited installation scenarios, and it is troublesome and labor-intensive to seamlessly join the aluminum plate and ceramic tile, and the specular emission of the aluminum plate and ceramic tile will increase the temperature, which will further affect the service life of the solar panel. Coated high-density linear polyethylene is a high-performance material, but its diffuse reflectance is about 0.56 to 0.58. The physical properties of coated high-density linear polyethylene are poor in strength, and when coarse denier and high density mesh are used, it is difficult to make the surface flat even after repeated casting. This process requires multiple reciprocating casting coatings, mainly due to the limited extrusion capacity of the die head, which results in very low production efficiency and limited production volume.

Regarding the shortcomings of the prior art, the objective of the present invention is to provide a flexible reflective material for increasing the light receiving rate of a double-glass solar panel, and a preparation method and use thereof. By using the flexible reflective material provided by the present invention, a diffuse reflectance of about 82% can be generated in the wavelength band of 280 nm to 1100 nm, which greatly increases the light receiving rate of the double-glass solar panel and improves the power generation efficiency. At the same time, by using the flexible reflective material provided by the present invention, the temperature of the double-glass solar panel does not increase, and the service life of the double-glass solar panel is extended.

To achieve the above objectives, the present invention employs the following technical solutions:

A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel includes:
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment;
Step S2: applying a primer coating treatment of PVC (polyvinyl chloride) paste resin slurry to the basic mesh processed in step S1, and a cover coating treatment of PVC paste resin slurry;
The method includes a step S3 of subjecting the basic mesh coated in the step S2 to a gelling treatment, drying and plasticizing treatment, and a step S4 of subjecting the basic mesh treated in the step S3 to a gravure printing surface treatment using polyvinylidene fluoride three times, an embossing treatment and a cooling setting treatment to obtain a flexible reflective material.

As a more preferred technical solution of the present invention, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is composed of the following ingredients by weight:

As a further preferred technical solution of the present invention, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is composed of the following ingredients by weight:

As a further preferred technical solution of the present invention, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is composed of the following ingredients by weight:

As a more preferred technical solution of the present invention, the tenter setting process in step S1 is carried out at 170 to 200°C for 120 to 180 seconds.

As a more preferred technical solution of the present invention, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes preparing rutile titanium dioxide into a 2%wt suspension, then adding 3% of sodium hexametaphosphate by weight of the suspension, shaking uniformly and heating to 70-75°C, adding 3% of sodium silicate solution by weight of the suspension, and adding dilute sulfuric acid to adjust the pH value of the system to 9, aging for 1.5 hours while keeping the temperature constant, and finally drying at 115°C, and grinding to a particle size of 0.15-0.5μm after drying to obtain modified titanium dioxide, where the modified titanium dioxide of 0.15-0.2μm is 53%-55%, the modified titanium dioxide of 0.2-0.5μm is 42%-46%, and the modified titanium dioxide of 0.4-0.5μm is 3%-5%.

As a more preferred technical solution of the present invention, the preparation of the above PVC paste resin slurry includes proportionally weighing each ingredient and mixing them uniformly.

As a more preferred technical solution of the present invention, the basis weight of the primer coating in step S2 is 115-125 grams, and the basis weight of the cover coating is 105-120 grams.

As a more preferred technical solution of the present invention, the gel treatment in step S3 is performed at 135 to 150°C for 35 to 45 seconds.

As a more preferred technical solution of the present invention, the dry plasticization in step S3 is carried out at 170 to 190°C for 60 to 90 seconds.

As a more preferred technical solution of the present invention, each gravure printing surface treatment with polyvinylidene fluoride in step S4 is dried at 130 to 150°C for 60 to 90 seconds to form a film, the thickness of which is 30 μm.

At the same time, the present invention further provides a flexible reflective material prepared by any one of the above methods.

At the same time, the present invention further provides the use of the above-mentioned flexible reflector to increase the light reception rate of a double-glazed solar panel.

Compared to the prior art, the present invention has the following beneficial effects:

(1) The method for preparing a flexible reflective material for enhancing the light receiving rate of a double-glazed solar panel provided by the present invention uses a special PVC paste resin slurry primer and overlay, and multiple surface treatments with polyvinylidene fluoride, to give the prepared flexible reflective material high diffuse reflectance (diffuse reflectance of 0.91 under visible light of 380 nm to 780 nm, and diffuse reflectance of 0.82 under ultraviolet UVA and UVB to near infrared light of 280 nm to 1100 nm), tensile strength, tear strength, weather resistance, and self-cleaning properties, which are suitable for the implementation requirements of solar cells in areas such as desertification.

(2) In the method for preparing a flexible reflective material for increasing the light receiving rate of a double-glazed solar panel provided by the present invention, the base mesh is treated with an ionic waterproofing agent by a padder and set, and has a wicking prevention function to prevent the absorption of dirt, sewage, etc., and the main material is protected from mold growth due to the absorption of dirt and sewage. The cationic waterproofing agent does not contain ammonium perfluorooctanoate and perfluorooctanesulfonyl compounds, so there is no environmental pollution. The functional coat of the primer and overlay PVC paste resin slurry provides excellent flame retardancy, weather resistance, and high diffuse reflectivity after gelation, drying, and plasticization. After three gravure printing surface treatments with polyvinylidene fluoride, a dense layer is formed on the surface, providing a plasticizer barrier, self-cleaning properties, abrasion resistance, and UV resistance. The surface of the three designed polyvinylidene fluoride By surface treatment, the entire surface can be coated with polyvinylidene fluoride film, but with a single surface treatment, the anilox roller has mesh-like walls and each mesh cannot transfer 100% of the ink carrying capacity to the substrate surface. Therefore, a process designed by overlapping surface treatment three times can completely coat the entire substrate surface, forming a good dense layer and providing excellent weather resistance and self-cleaning properties. The bond energy of polyvinylidene fluoride is 485 KJ/mol, which is higher than UVA's 340 KJ/mol and UVB's 380 KJ/mol, providing excellent weather resistance. Polyvinylidene fluoride has low surface energy, so sand that falls on the material surface is easily blown away by the wind, and dirt on the surface is easily washed away by rain, giving it excellent self-cleaning properties as a reflective material.

(3) The PVC paste resin slurry used in the primer and overlay provided by the present invention was creatively proposed by the applicant. The cresyl diphenyl phosphate used in the slurry has excellent electrical insulation, low temperature resistance, and hydrolysis resistance, as well as good plasticity. The coating film is light in weight, making it difficult to achieve an ideal coat using antimony trioxide alone. Because it has a flame retardant effect, the flame retardant effect is achieved through the synergistic effect of toluene diphenyl phosphate, a flame retardant plasticizer, and antimony trioxide.

(4) The dioctadecyl pentaerythritol diphosphite used in the PVC paste resin slurry provided by the present invention is a substance containing tetraerythritol ester and phosphite ester, and the phosphite ester has excellent hydroperoxide decomposition ability (not found in tetraerythritol ester, a hindered phenol antioxidant), as well as good color protection performance, and can bleach the dye base after the oxidation of tetraerythritol ester, a hindered phenol antioxidant. In addition, dioctadecyl pentaerythritol diphosphite, fatty acid zinc in the powdered calcium zinc stabilizer, and epoxidized soybean oil in the formulation form a stable system and obtain a synergistic effect with the ultraviolet absorber, and the three substances synergistically make the antioxidant effect more prominent and efficient, can capture free radicals, have a good stabilization effect, have good thermal stability and color stabilization effects during product processing, and are excellent in thermal stability, weather resistance, hydrolysis resistance, and product transparency retention during subsequent use. At the same time, the dioctadecyl pentaerythritol diphosphite and powdered calcium zinc stabilizer used in the present invention have low toxicity, avoiding potential toxicity caused by substances such as nonylphenol, bisphenol A, and free phenol that are present when using traditional phosphate antioxidants and liquid barium zinc stabilizers.

(5) The plasticizer used in the PVC paste resin slurry provided by the present invention is LINPLAST 1012 BP, which has high temperature resistance and can avoid the deficiencies such as high viscosity, rapid increase in slurry viscosity during coating, and short open time that are present in substances such as trioctyl trimellitate that are conventionally used. At the same time, the plasticizer LINPLAST 1012 BP is also low temperature resistant and has low toxicity, and is equivalent to dioctyl sebacate.

(6) The modified titanium dioxide used in the PVC paste resin slurry provided by the present invention is obtained by coating rutile titanium dioxide with silicon dioxide. The refractive index of rutile titanium dioxide is about 2.73, but the surface of pure rutile titanium dioxide particles is photochemically active and non-photochemically stable in the presence of water vapor and oxygen, which may promote the decomposition of the substrate around the particles. Therefore, in the present invention, when it is used after being coated with silicon dioxide, a shielding net is formed between the surface around the titanium dioxide particles and the organic resin, which greatly reduces the decomposition of the organic resin and photostabilizes the rutile titanium dioxide. And the rutile titanium dioxide coated with silicon dioxide can effectively prevent the aggregation of rutile titanium dioxide, which reduces the diffuse reflection of light. The rutile titanium dioxide coated with silicon dioxide has strong powder resistance, and even if the surface of the main resin undergoes photochemical decomposition under various harsh environments, the titanium dioxide and the like protrude to the surface, greatly delaying further grinding.

(7) The nano calcium carbonate used in the PVC paste resin slurry provided by the present invention can form a synergistic high diffuse reflection effect with the modified titanium dioxide. However, when the diameter of the filler particles is large, a window effect is formed, the light flux increases, and the effective diffuse reflection decreases. As a result of repeated experiments in the present invention, it has been found that the 3000 mesh nano calcium carbonate has a space-filling effect, and can effectively synergistically modify the titanium dioxide to increase the diffuse reflectance. In addition, the plasticizer LINPLAST 1012 BP and the powdered calcium zinc stabilizer do not contain nonylphenol, bisphenol A, and free phenol, so that the modified titanium dioxide can also be effectively prevented from reacting with phenol to form colored products at a later stage. At the same time, UVA is long-wave infrared radiation with a wavelength of 320 to 400 nm, UVB is medium-wave ultraviolet radiation with a wavelength of 290 to 320 nm, visible light (long wave) has a wavelength of 380 to 780 nm, and near-infrared short wave has a wavelength of 780 to 1100 nm, and the light that reaches the earth is mainly visible light centered around these bands. If effective light reflection is required, the diameter of the modified titanium dioxide should be slightly smaller than half of the scattered light. According to the spectral wavelength distribution near the ground, the diameter of the modified titanium dioxide is determined to be 0.15 μm to 0.5 μm. By adjusting the particle size distribution of the modified titanium dioxide, the linear diffuse reflection of different wavelength bands from 280 nm to 1100 nm is realized, where the modified titanium dioxide of 0.15 μm to 0.2 μm is 53% to 55%, the modified titanium dioxide of 0.2 to 0.5 μm is 42% to 46%, and the modified titanium dioxide of 0.4 μm to 0.5 μm is 3% to 5%. This distribution achieves a high diffuse reflectance of 91% at 380nm to 780nm (visible light) and 82% at 280nm to 1100nm (from ultraviolet UVA and UVB to near infrared), and the linear diffuse reflection of each wavelength band does not increase the temperature of the solar panel, so it does not affect the service life of the solar panel.

(8) In the PVC paste resin slurry provided by the present invention, the cellulose acetate butyrate used can improve the distribution of nano calcium carbonate and modified titanium dioxide, further improving the reflective ability of the material.

In summary, the flexible reflective material provided by the present invention has high reflectivity, excellent weather resistance, and does not cause the temperature of the solar panel to rise. The flexible reflective material prepared by the present invention is flexible overall, easy to construct, install, and maintain, and is suitable for the installation and use requirements of solar cells in various situations.

FIG. 1 is a schematic diagram of the product prepared in Example 1 of the present invention. FIG. 2 is a schematic diagram of the implementation of the use of the product prepared in Example 1 of the present invention to enhance the light receiving efficiency of a double-glass solar panel.

In order to make the present invention, its technical solution and advantages clearer, the present invention will be described in more detail in the following in combination with examples. All raw materials used in the present invention are purchased from the market unless otherwise specified.

Some of the grades or specifications of the materials used in the present invention are as follows:
TDI adhesive: TDI-100,
Nano calcium carbonate: 3000 mesh,
PVC paste resin: Germany Vinnolit S3157/11,
Waterproofing agent: Grade is KDWF-528.

Example 1
A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel includes:
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment, in which the tenter setting treatment is performed at 180° C. for 150 seconds;
Step S2, the basic mesh processed in step S1 is subjected to a primer coating of PVC paste resin slurry and a cover coating of PVC paste resin slurry, where the basis weight of the primer coating is 115 grams and the basis weight of the cover coating is 105 grams;
The basic mesh coated in step S2 is subjected to a gelling treatment, a drying and plasticizing treatment, in which the gelling treatment is performed at 135°C for 35 seconds, and the drying and plasticizing treatment is performed at 175°C for 65 seconds; and the basic mesh treated in step S3 is subjected to a gravure printing surface treatment with polyvinylidene fluoride three times (each gravure printing surface treatment with polyvinylidene fluoride is dried at 135°C for 60 seconds to form a film, and the thickness of the film is 30 μm), an embossing treatment, and a cooling and setting treatment to obtain a flexible reflective material in step S4.
Here, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is prepared from the following raw materials.

The processes involved in this embodiment, such as waterproofing, tenter setting, gelation, drying plasticization, and gravure printing surface treatment using polyvinylidene fluoride, all exist in the prior art, and the specific steps of the above processes are not limited in this embodiment.

As a more preferred technical solution of this embodiment, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes preparing rutile titanium dioxide into a 2%wt suspension, then adding 3% of sodium hexametaphosphate by weight of the suspension, shaking uniformly and heating to 75°C, then adding 3% of sodium silicate solution by weight of the suspension and adding dilute sulfuric acid to adjust the pH value of the system to 9, keeping the temperature constant and aging for 1.5 hours, finally drying at 115°C, and grinding to a particle size of 0.15-0.5μm after drying to obtain modified titanium dioxide, where 0.15-0.2μm modified titanium dioxide is 53%, 0.2-0.5μm modified titanium dioxide is 42%, and 0.4-0.5μm modified titanium dioxide is 5%.

As a further preferred technical solution of this embodiment, the preparation of the above PVC paste resin slurry includes proportionally weighing each ingredient and mixing them uniformly.

As a more preferred technical solution of this embodiment, the ultraviolet absorber is one or two selected from benzophenones such as 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 4-dihydroxybenzophenone, and in this embodiment, 2-hydroxy-4-n-octyloxybenzophenone is specifically used.

A schematic diagram of the flexible reflective product prepared in this example is shown in Figure 1.

Example 2
A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel includes:
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment, in which the tenter setting treatment is performed at 180° C. for 160 seconds;
Step S2: the basic mesh processed in step S1 is subjected to a primer coating of PVC paste resin slurry and a cover coating of PVC paste resin slurry, where the basis weight of the primer coating is 120 grams and the basis weight of the cover coating is 110 grams;
The method includes: (a) subjecting the basic mesh coated in step S2 to a gelling treatment, a drying and plasticizing treatment, in which the gelling treatment is gelling at 140°C for 40 seconds, and the drying and plasticizing treatment is drying and plasticizing at 180°C for 70 seconds; and (b) subjecting the basic mesh treated in step S3 to a gravure printing surface treatment with polyvinylidene fluoride three times (each gravure printing surface treatment with polyvinylidene fluoride is formed at 140°C for 70 seconds, and the thickness of the formed film is 30 μm), an embossing treatment, and a cooling and setting treatment to obtain a flexible reflective material in step S4;
Here, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is prepared from the following raw materials.

The processes involved in this embodiment, such as waterproofing, tenter setting, gelation, drying plasticization, and gravure printing surface treatment using polyvinylidene fluoride, all exist in the prior art, and the specific steps of the above processes are not limited in this embodiment.

As a more preferred technical solution of this embodiment, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes preparing rutile titanium dioxide into a 2%wt suspension, then adding 3% of sodium hexametaphosphate by weight of the suspension, shaking uniformly and heating to 75°C, then adding 3% of sodium silicate solution by weight of the suspension and adding dilute sulfuric acid to adjust the pH value of the system to 9, keeping the temperature constant and aging for 1.5 hours, finally drying at 115°C, and grinding to a particle size of 0.15-0.5μm after drying to obtain modified titanium dioxide, where 0.15-0.2μm modified titanium dioxide is 54%, 0.2-0.5μm modified titanium dioxide is 43%, and 0.4-0.5μm modified titanium dioxide is 3%.

As a further preferred technical solution of this embodiment, the preparation of the above PVC paste resin slurry includes proportionally weighing each ingredient and mixing them uniformly.

As a more preferred technical solution of this embodiment, the ultraviolet absorber is one or two selected from benzophenones such as 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 4-dihydroxybenzophenone, and in this embodiment, 2-hydroxy-4-n-octyloxybenzophenone is specifically used.

Example 3
A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel includes:
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment, in which the tenter setting treatment is performed at 190° C. for 1750 seconds;
Step S2, the basic mesh processed in step S1 is subjected to a primer coating of PVC paste resin slurry and a cover coating of PVC paste resin slurry, where the basis weight of the primer coating is 125 grams and the basis weight of the cover coating is 115 grams;
The basic mesh coated in step S2 is subjected to a gelling treatment, a drying and plasticizing treatment, in which the gelling treatment is performed at 145°C for 45 seconds, and the drying and plasticizing treatment is performed at 185°C for 75 seconds; and the basic mesh treated in step S3 is subjected to a gravure printing surface treatment with polyvinylidene fluoride three times (each gravure printing surface treatment with polyvinylidene fluoride is dried at 145°C for 60 seconds to form a film, and the thickness of the film is 30 μm), an embossing treatment, and a cooling and setting treatment to obtain a flexible reflective material in step S4.
Here, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is prepared from the following raw materials.

The processes involved in this embodiment, such as waterproofing, tenter setting, gelation, drying plasticization, and gravure printing surface treatment using polyvinylidene fluoride, all exist in the prior art, and the specific steps of the above processes are not limited in this embodiment.

As a more preferred technical solution of this embodiment, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes preparing rutile titanium dioxide into a 2%wt suspension, then adding 3% of sodium hexametaphosphate by weight of the suspension, shaking uniformly and heating to 75℃, then adding 3% of sodium silicate solution by weight of the suspension and adding dilute sulfuric acid to adjust the pH value of the system to 9, keeping the temperature constant and aging for 1.5 hours, finally drying at 115℃, and grinding to a particle size of 0.15-0.5μm after drying to obtain modified titanium dioxide, where 0.15-0.2μm modified titanium dioxide is 54%, 0.2-0.5μm modified titanium dioxide is 42%, and 0.4-0.5μm modified titanium dioxide is 4%.

As a further preferred technical solution of this embodiment, the preparation of the above PVC paste resin slurry includes proportionally weighing each ingredient and mixing them uniformly.

As a more preferred technical solution of this embodiment, the ultraviolet absorber is one or two selected from benzophenones such as 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 4-dihydroxybenzophenone, and in this embodiment, 2-hydroxy-4-n-octyloxybenzophenone is specifically used.

Comparative Example 1
A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel;
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment, in which the tenter setting treatment is performed at 180° C. for 150 seconds;
Step S2: the basic mesh processed in step S1 is subjected to a primer coating of PVC paste resin slurry and a cover coating of PVC paste resin slurry, where the basis weight of the primer coating is 115 grams and the basis weight of the cover coating is 105 grams;
The basic mesh coated in step S2 is subjected to a gelling treatment, a drying and plasticizing treatment, in which the gelling treatment is performed at 135°C for 35 seconds, and the drying and plasticizing treatment is performed at 175°C for 65 seconds; and the basic mesh treated in step S3 is subjected to a gravure printing surface treatment with polyvinylidene fluoride three times (each gravure printing surface treatment with polyvinylidene fluoride is dried at 135°C for 60 seconds to form a film, and the thickness of the film is 30 μm), an embossing treatment, and a cooling and setting treatment to obtain a flexible reflective material in step S4.
Here, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is prepared from the following raw materials.

The processes involved in this embodiment, such as waterproofing, tenter setting, gelation, drying plasticization, and gravure printing surface treatment using polyvinylidene fluoride, all exist in the prior art, and the specific steps of the above processes are not limited in this embodiment.

In this comparative example, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes preparing rutile titanium dioxide into a 2% wt suspension, then adding sodium hexametaphosphate at 3% of the suspension weight, shaking uniformly and heating to 75°C, then adding sodium silicate solution at 3% of the suspension weight and adding dilute sulfuric acid to adjust the pH value of the system to 9, aging for 1.5 hours while keeping the temperature constant, and finally drying at 115°C to obtain modified titanium dioxide, where the modified titanium dioxide has a particle size of more than 0.5 μm at about 90%.

In this comparative example, the preparation of the PVC paste resin slurry involves proportionally weighing each ingredient and mixing them uniformly.

In this comparative example, the UV absorber is 2-hydroxy-4-n-octyloxybenzophenone.

Comparative Example 2
A method for preparing a flexible reflective material for increasing the light receiving rate of a double glass solar panel includes:
A step S1 of obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material, and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment, in which the tenter setting treatment is performed at 180° C. for 150 seconds;
Step S2, the basic mesh processed in step S1 is subjected to a primer coating of PVC paste resin slurry and a cover coating of PVC paste resin slurry, where the basis weight of the primer coating is 115 grams and the basis weight of the cover coating is 105 grams;
The basic mesh coated in step S2 is subjected to a gelling treatment, a drying and plasticizing treatment, in which the gelling treatment is performed at 135°C for 35 seconds, and the drying and plasticizing treatment is performed at 175°C for 65 seconds; and the basic mesh treated in step S3 is subjected to a gravure printing surface treatment with polyvinylidene fluoride three times (each gravure printing surface treatment with polyvinylidene fluoride is dried at 135°C for 60 seconds to form a film, and the thickness of the film is 30 μm), an embossing treatment, and a cooling and setting treatment to obtain a flexible reflective material in step S4.
Here, the PVC paste resin slurry used for the primer coating and cover coating in step S2 is prepared from the following raw materials.

The processes involved in this embodiment, such as waterproofing, tenter setting, gelation, drying plasticization, and gravure printing surface treatment using polyvinylidene fluoride, all exist in the prior art, and the specific steps of the above processes are not limited in this embodiment.

In this comparative example, the preparation of modified titanium dioxide in the above PVC paste resin slurry includes mixing rutile titanium dioxide and silicon dioxide in a weight ratio of 1:1, and then grinding to a particle size of 0.15-0.5 μm to obtain modified titanium dioxide, in which the modified titanium dioxide of 0.15-0.2 μm is 53%, the modified titanium dioxide of 0.2-0.5 μm is 42%, and the modified titanium dioxide of 0.4-0.5 μm is 5%.

In this comparative example, the preparation of the PVC paste resin slurry involves proportionally weighing each ingredient and mixing them uniformly.

In this comparative example, the UV absorber is 2-hydroxy-4-n-octyloxybenzophenone.

The reflectance performance tests of the flexible reflective materials prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were conducted in accordance with ASTM E903, and the test results are shown in Table 1.

From Table 1, it can be seen that the flexible reflective materials prepared in each embodiment of the present invention can produce high diffuse reflectance at 380-780 nm (visible light) and 280-1100 nm (ultraviolet rays UVA and UVB to near infrared), which can reach 0.91 or more and 0.82 or more, respectively, and have better reflective effects than white ceramic tiles (0.55), polished oxidized aluminum plates (about 0.50), and coated high-density linear polyethylene (about 0.56-0.58). At the same time, the flexible reflective materials prepared by the present invention are flexible as a whole, applicable to various scenes, and easy to construct, implement, and maintain.

In an actual application project (see Figure 2 for the implementation schematic), the flexible reflective material prepared in Example 1 of the present invention is used in a solar power generation project, which can increase the light receiving rate of the double-glass solar panel, improve the power generation efficiency, and increase the power generation rate by about 10.32%. At the same time, the double-glass solar panel using the flexible reflective material of the present invention does not increase in temperature, and the service life of the solar panel is extended, which indirectly improves the economic benefits.

The above examples are only intended to illustrate the technical concepts and features of the present invention, to enable those skilled in the art to understand and implement the contents of the present invention accordingly, and do not limit the scope of protection. All equivalent changes or modifications made in accordance with the spirit of the present invention shall be included within the scope of protection of the present invention.

Claims (9)

A method for preparing a flexible reflective material for increasing the light receiving rate of a double-glazed solar panel, comprising the steps of: obtaining a basic mesh by warp knitting or machine weaving using polyester yarn as a raw material; and then subjecting the basic mesh to a waterproofing treatment and a tenter setting treatment in step S1;
A process S2 of subjecting the basic mesh processed in the process S1 to a primer coating process using a PVC paste resin slurry and a cover coating process using a PVC paste resin slurry;
The method includes a step S3 of subjecting the basic mesh coated in the step S2 to a gelling treatment, a drying and plasticizing treatment, and a step S4 of subjecting the basic mesh treated in the step S3 to a gravure printing surface treatment using polyvinylidene fluoride three times, an embossing treatment, and a cooling setting treatment to obtain a flexible reflective material.
The PVC paste resin slurry used for the primer coating and cover coating in step S2 is composed of the following ingredients by weight:

The preparation of the PVC paste resin slurry comprises proportionally weighing each ingredient and mixing them uniformly. The preparation method according to claim 1, characterized in that the tenter setting process in step S1 is performed at 170 to 200°C for 120 to 180 seconds. The preparation of the modified titanium dioxide in the PVC paste resin slurry includes: preparing rutile titanium dioxide into a 2% wt suspension; then adding sodium hexametaphosphate of 3% of the suspension weight; shaking uniformly and heating to 70-75°C; adding sodium silicate solution of 3% of the suspension weight and adding dilute sulfuric acid to adjust the pH value of the system to 9; keeping the temperature constant and aging for 1.5 hours; finally drying at 115°C; and polishing to a particle size of 0.15-0.5 μm after drying to obtain modified titanium dioxide;
The preparation method according to claim 1, characterized in that the modified titanium dioxide of 0.15-0.2 μm is 53%-55%, the modified titanium dioxide of 0.2-0.5 μm is 42%-46%, and the modified titanium dioxide of 0.4-0.5 μm is 3%-5%. The preparation method according to claim 1, characterized in that the basis weight of the primer coating in step S2 is 115 to 125 grams, and the basis weight of the cover coating is 105 to 120 grams. The preparation method according to claim 1, characterized in that the gelling treatment in step S3 is carried out at 135 to 150°C for 35 to 45 seconds. The preparation method according to claim 1, characterized in that the drying and plasticizing in step S3 is carried out at 170 to 190°C for 60 to 90 seconds. The preparation method according to claim 1, characterized in that each gravure printing surface treatment with polyvinylidene fluoride in step S4 is dried at 130 to 150°C for 60 to 90 seconds to form a film, and the thickness of the formed film is 30 μm. A flexible reflective material obtained by the preparation method according to any one of claims 1 to 7. Use of the flexible reflector of claim 8 to increase the light reception rate of a double-glazed solar panel.

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