Highly transparent composite glass cloth and lightweight solar cell module

Abstract

The present invention belongs to the technical field of solar cell modules, and specifically relates to a highly transparent composite glass cloth and a lightweight solar cell module. It includes a glass cloth and an adhesive coated on the surface of the glass cloth, and the adhesive includes an acrylic resin, a low molecular weight polyacrylate, a low temperature curing polyester resin and a curing agent. The technical solution provided by the present invention solves the problem that the lightweight solar cell module is not strong enough and cannot pass the hail resistance test by adding a highly light-transmitting composite glass cloth between the battery cell and the packaging film. The acrylic resin composite glass cloth provided has high light transmittance and will not affect the conversion efficiency of the battery. Through the compounding of multiple thermosetting resins, it is not sticky when dried at a relatively low temperature during compounding. The existing parts are assembled and cured at high temperature to produce strong adhesion with the packaging film and the battery cell, thus realizing the organic combination of preliminary preparation and subsequent processing.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cell modules, and in particular relates to a highly transparent composite glass cloth and a lightweight solar cell module. Background Art

[0002] The heavy overall weight of solar cell modules limits their application in certain areas with limited load capacity. In order to reduce the weight of the modules, most of them remove the glass and frames and use polymer materials as the front and back panels. The weight of the modules can be reduced by about 70% compared with conventional modules, effectively reducing the unit weight of the modules.

[0003] The structure of a lightweight solar cell module is generally: polymer transparent front plate + encapsulation film + battery cell + encapsulation film + polymer back plate. In the prior art, a lightweight solar cell module is produced by pressing a polymer transparent front plate, an encapsulation film, a battery cell, an encapsulation film and a polymer back plate together.

[0004] However, polymer materials generally have poor impact resistance and cannot pass hail resistance tests. Solar cell modules cannot be deployed in extreme climates, places with ice, snow, hail, or where there is a risk of falling objects from high altitudes. Lightweight modules need to be further strengthened. The strengthening method can be to add a reinforcement layer between the encapsulation film and the battery cell. The reinforcement layer on the front panel side needs to be impact-resistant and have strong adhesion to the encapsulation film and the battery cell. More importantly, it needs to be highly transparent, otherwise it will seriously affect the conversion efficiency of the battery cell. Summary of the invention

[0005] The invention provides a highly transparent composite glass cloth and a light solar cell assembly, which are used to solve the problem of poor impact resistance of the current light solar cell assembly.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: the highly transparent composite glass cloth comprises glass cloth and an adhesive coated on the surface of the glass cloth, wherein the adhesive comprises acrylic resin, low molecular weight polyacrylate, low temperature curing polyester resin and curing agent;

[0007] The softening point temperature of the acrylic resin is 90-110°C;

[0008] The relative molecular weight of the low molecular weight polyacrylic acid is 2000-4000;

[0009] The low-temperature curing polyester resin is a polyester resin prepared by using trimethylolpropane, neopentyl glycol and terephthalic acid as polymerization monomers;

[0010] The curing agent is TGIC (triglycidyl isocyanurate).

[0011] Optionally, the components of the adhesive are proportioned in parts by weight as follows:

[0012]

[0013] Optionally, the polymerizable monomers of the acrylic resin include styrene, methyl methacrylate, n-butyl methacrylate and glycidyl methacrylate, and the initiator is BOP (dibenzoyl peroxide).

[0014] Optionally, the polymerization monomers of the low-temperature curing polyester resin include neopentyl glycol, trimethylolpropane and terephthalic acid, and the catalyst is monobutyltin oxide.

[0015] Optionally, the method for preparing the acrylic adhesive comprises the following steps: weighing the components according to the formula and mixing them, kneading and extruding them into tablets in a twin-screw extruder, and after cooling, crushing the tablets into powder using a pulverizer.

[0016] Optionally, the preparation method of the high-transparency composite glass cloth includes the following steps: pulling the glass cloth roll through a traction roller, applying a powdered adhesive on both surfaces of the glass cloth through a high-voltage electrostatic spray gun, and then passing it through two heating rollers for extrusion and heating, the temperature of the heating rollers is 100-110°C, and the adhesive is partially solidified on the surface of the glass cloth.

[0017] The present invention also provides a solar cell lightweight component, which comprises a polymer front plate, a packaging film, the above-mentioned high-transparency composite glass cloth, a battery cell, the above-mentioned high-transparency composite glass cloth, a packaging film and a polymer back plate.

[0018] Optionally, the polymer front panel, the packaging film, the above-mentioned high-transparency composite glass cloth, the battery cell, the above-mentioned high-transparency composite glass cloth, the packaging film and the polymer back panel are stacked in sequence and pressed by a press in a vacuum environment at a pressing temperature of 130-150° C. for 30-40 minutes.

[0019] Optionally, the packaging film is an EVA (ethylene-vinyl acetate copolymer) film.

[0020] The technical solution provided by the present invention solves the problem that the lightweight solar cell module is not strong enough and cannot pass the hail resistance test by adding a high-transmittance composite glass cloth between the battery cell and the packaging film. The acrylic resin composite glass cloth provided has high light transmittance and will not affect the conversion efficiency of the battery. Through the compounding of multiple thermosetting resins, it is not sticky to the hands by drying at a relatively low temperature during compounding. The existing parts can be assembled and cured at a high temperature to produce strong adhesion with the packaging film and the battery cell, thereby realizing the organic combination of early preparation and subsequent processing. DETAILED DESCRIPTION

[0021] For ease of understanding, the highly transparent composite glass cloth and the lightweight solar cell assembly are described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0022] Example 1 Synthesis of acrylic resin

[0023] The preparation method is as follows: by weight, 15 parts of styrene, 30 parts of methyl methacrylate, 15 parts of n-butyl methacrylate, 40 parts of glycidyl methacrylate monomer and 2 parts of BPO are mixed evenly, the toluene solution is heated to about 120°C, and the above mixture is added dropwise at a uniform speed. After the polymerization reaction is completed, the mixture is cooled to room temperature, and the toluene is removed by reduced pressure distillation to obtain an acrylic resin with a softening point temperature of 90-100°C.

[0024] Example 2 Synthesis of low temperature curing polyester resin

[0025] In parts by weight, 42 parts of neopentyl glycol, 8 parts of trimethylolpropane, 50 parts of terephthalic acid, 0.1 parts of catalyst monobutyl tin oxide, etc. are added into a reaction kettle, and the temperature is slowly raised to 235-245°C under the protection of nitrogen and maintained. When the acid value reaches 5-10 mgKOH / g, the temperature is lowered to 210°C, adipic acid and isophthalic acid are added, the temperature is raised to about 240°C at a rate of 10°C / h and maintained to an acid value of 60-65 mgKOH / g, vacuum decompression is carried out for 2h, the temperature is lowered to 205-210°C, an antioxidant is added, and the temperature is maintained for 20 minutes before discharging.

[0026] Example 3-5 Preparation of Highly Transparent Composite Glass Cloth

[0027] Acrylic resin, low molecular weight polyacrylate, low temperature curing polyester resin and curing agent are weighed and mixed according to the formula in Table 1. When the gapless twin-screw extruder reaches the set temperature, the cooling water pipeline is opened, the feeding speed and the screw speed are adjusted, and the raw materials are poured into the twin-screw extruder for extrusion and sheeting. The extrusion temperature includes the first zone extrusion temperature and the second zone extrusion temperature. The first zone extrusion temperature is 80-100°C and the second zone extrusion temperature is 80-90°C. After the sheet is cooled, it is placed in a pulverizer and crushed into powder. The powder is sieved out with a 180-mesh sample sieve, that is, the powdered adhesive.

[0028] The glass cloth is pulled by a pulling roller, and a powdered adhesive is applied on both surfaces of the glass cloth by a high-voltage electrostatic spray gun. The glass cloth is then passed through two heating rollers for extrusion and heating. The temperature of the heating rollers is 100-110°C, and the adhesive is partially solidified on the surface of the glass cloth.

[0029] Table 1

[0030] Acrylic resin (parts) Low molecular weight polyacrylic acid (parts) Low temperature curing polyester resin (parts) TGIC (unit) Example 3 100 100 55 2 Example 4 100 110 50 2 Example 5 110 100 55 2.2

[0031] The acrylic resin is prepared as in Example 1;

[0032] Low molecular weight polyacrylic acid was purchased from Tolite Environmental Protection Technology (Guangzhou) Co., Ltd., with a relative molecular weight of about 2500;

[0033] The low temperature curing polyester resin is prepared as in Example 2;

[0034] TGIC was purchased from Nissan TEPIC-G in Japan.

[0035] Example 6-8 Lightweight solar cell assembly

[0036] The polymer front plate, the encapsulation film, the above-mentioned highly transparent composite glass cloth, the battery cell, the above-mentioned highly transparent composite glass cloth, the encapsulation film and the polymer back plate are stacked in sequence and pressed by a press in a vacuum environment at a temperature of 130-150° C. for 30-40 minutes.

[0037] The composite glass cloth for solar cells described in Examples 6-8 is prepared in Example 3-5, respectively.

[0038] The material of the polymer front plate is the composite film disclosed in CN108091715A.

[0039] The material of the polymer backplane is the PVDF film disclosed in CN105895722A.

[0040] Comparative Example 1

[0041] The difference from Example 1 is that the adhesive does not contain low-temperature curing polyester resin, and the surface is smooth and does not stick to the hands after being compounded with the glass cloth.

[0042] Comparative Example 2

[0043] The difference from Example 1 is that the adhesive does not contain acrylic resin and low molecular weight polyacrylic acid, and after being heated by the heating roller, the adhesive cannot be completely attached to the surface of the glass cloth, and lamination cannot be achieved. The temperature of the heating roller is increased to above 150° C. to complete the lamination.

[0044] Comparative Example 3

[0045] The difference from Example 1 is that the content of acrylic resin in the adhesive is 100 parts, the content of low molecular weight polyacrylic acid is 50 parts, and the surface of the prepared composite glass cloth for solar cells is sticky.

[0046] Comparative Examples 4-6 Lightweight Solar Cell Components

[0047] The difference between Comparative Examples 4-5 and Examples 6-8 is that the composite glass cloths on both sides of the battery cells are prepared in turn by Comparative Examples 1, 2 and 3. In Comparative Example 3, the composite glass cloth layers adhere to each other during lamination, and it is easy to adhere to other layers when laying a multi-layer structure, making it difficult to lay in place.

[0048] Comparative Example 7

[0049] The difference from Example 6 is that no reinforcing material is provided on both sides of the battery cell.

[0050] Performance Experiment

[0051] In order to verify that the prepared composite glass cloth meets the requirements of solar cell modules, the solar cell modules of Examples 6-8 and Comparative Examples 4-5 were subjected to weather resistance tests, electrical performance tests, impact resistance tests, bonding strength tests with EVA, bonding strength tests with battery cells, and transmittance tests. The test results are shown in Table 2.

[0052] Table 2

[0053]

[0054] In Comparative Example 4, since there is no low-temperature curing polyester resin, the adhesive is basically completely cross-linked and cured after being compounded with the glass cloth, so when it is subsequently pressed with other layers, it cannot bond with the EVA and the battery sheet. Since it is impossible to prepare a usable solar cell module, other properties are not examined.

[0055] In Comparative Example 5, since the composite was achieved by direct drying at 150°C when composited with glass, no cross-linking and curing reaction could occur when subsequently laminated with other layers, and no adhesion could be generated with EVA and the cell sheet. Since a usable solar cell module could not be prepared, other properties were not examined.

[0056] The content of low molecular weight polyacrylic acid in Comparative Example 6 is greatly reduced, which makes mixing difficult and the composite glass cloth has the problem of being sticky to the hands, which is not conducive to subsequent processing.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly transparent composite glass cloth, characterized in that: It comprises glass cloth and an adhesive coated on the surface of the glass cloth, wherein the adhesive comprises acrylic resin, low molecular weight polyacrylate, low temperature curing polyester resin and curing agent; The softening point temperature of the acrylic resin is 90-110°C; The relative molecular weight of the low molecular weight polyacrylic acid is 2000-4000; The low-temperature curing polyester resin is a polyester resin prepared by using trimethylolpropane, neopentyl glycol and terephthalic acid as polymerization monomers; The curing agent is TGIC.

2. The highly transparent composite glass cloth according to claim 1, characterized in that: The components of the adhesive are proportioned in parts by weight as follows:

3. The highly transparent composite glass cloth according to claim 1, characterized in that: The polymerization monomers of the acrylic resin include styrene, methyl methacrylate, n-butyl methacrylate and glycidyl methacrylate, and the initiator is BOP.

4. The highly transparent composite glass cloth according to claim 1, characterized in that: The polymerization monomers of the low-temperature curing polyester resin include neopentyl glycol, trimethylolpropane and terephthalic acid, and the catalyst is monobutyl tin oxide.

5. The highly transparent composite glass cloth according to claim 1, characterized in that: The preparation method of the acrylic adhesive comprises the following steps: weighing the components according to the formula and mixing them, kneading and extruding them in a twin-screw extruder to form tablets, and after cooling, crushing the tablets into powders by a crusher.

6. The highly transparent composite glass cloth according to claim 1, characterized in that: The preparation method of the high-transparency composite glass cloth comprises the following steps: pulling a glass cloth roll by a pulling roller, applying a powdered adhesive on the two surfaces of the glass cloth by a high-voltage electrostatic spray gun, and then passing the glass cloth through two heating rollers for extrusion heating, the temperature of the heating rollers is 100-110° C., and the adhesive is partially solidified on the surface of the glass cloth.

7. A lightweight solar cell assembly, comprising a polymer front sheet, a packaging film, a thermosetting resin composite glass cloth, a battery sheet, a thermosetting resin composite glass cloth, a packaging film and a polymer back sheet, characterized in that: The thermosetting resin composite glass cloth near the polymer front plate is the highly transparent composite glass cloth as claimed in any one of claims 1 to 6.

8. The solar cell lightweight assembly according to claim 7, characterized in that: The seven layers of membranes are stacked in sequence and pressed by a press under a vacuum environment at a temperature of 130-150°C for 30-40 minutes.

9. The solar cell lightweight assembly according to claim 7, characterized in that: The packaging film is an EVA film.

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