CN104448512A - Encapsulation film composition for solar cell module - Google Patents

Abstract

The present invention provides a packaging film composition for a solar cell module, which comprises: a transparent resin accounting for 80-99% of the total weight of the composition; granular polymer particles accounting for 0.5-10% of the total weight of the composition; and additives accounting for 0.1-5% of the total weight of the composition; the light diffusion control mechanism of the granular polymer particles is used to control the refraction of light, which can increase the probability of a solar cell receiving light, thereby improving the light conversion efficiency of the cell.

Description

Encapsulation film composition for solar cell module

technical field

The present invention relates to an encapsulation film composition for a solar cell module; in particular, it relates to a composition containing granular polymer particles that can regulate the refraction of light through a light diffusion mechanism, so as to increase the probability of the solar cell receiving light. Further, the solar cell module encapsulating film composition improves the light conversion efficiency of the cell.

Background technique

A solar cell is a structure that converts sunlight into electricity. Around the 1970s, people began to use transparent resin for module packaging to block the influence of air and moisture on solar cells, and reduce the damage rate of the cells, so as to increase industrial practicability.

Common transparent resins are ethylene-vinyl acetate copolymer (EVA) resin, polyvinyl butyral (PVB) resin and thermoplastic polyolefin resin with high light transmittance, among which ethylene-vinyl acetate copolymer resin has With the advantages of low cost and good light transmittance, it is currently widely used as a packaging material for solar cells. In addition, there are also technical solutions using other transparent resins. For example, the US2012260975A1 patent uses thermoplastic acrylic elastomer resin. Through the characteristics of high light transmittance, low haze and no need to add ultraviolet light absorbers, it can improve the probability of solar cells receiving light. lifespan.

But there is the problem that ethylene-vinyl acetate copolymer (EVA) is easily damaged by ultraviolet (UV) light and/or heat and reduces lifespan, in order to solve this problem, US6093757, WO06093936, JP2000183382, US7368655, EA0001908 and US5447576 etc. Patent proposals include adding UV light absorbers to improve UV resistance of transparent resins, adding heat stabilizers to improve thermal degradation resistance of transparent resins, and/or adding resin accelerators such as peroxides to rapidly harden transparent resins And it will not form a solution such as photoacid. However, after improving the UV resistance and heat resistance of the transparent resin, the additive will absorb light sources of certain wavelengths, reducing the probability of solar cells receiving light, resulting in solar cells after packaging. Photovoltaic cells have a problem of reduced light conversion efficiency. In order to pursue low cost and high performance, improving the performance of solar cells by improving the packaging film is the current industry demand.

Contents of the invention

The object of the present invention is to provide an encapsulating film composition for a solar cell module that can increase the probability of the solar cell module receiving light, thereby improving the light conversion efficiency of the cell.

In order to achieve the above object, the present invention provides a solar cell module encapsulation film composition, which includes: accounting for 80-99% of the total weight of the composition transparent resin; accounting for 0.5-99% of the total weight of the composition 10% of granular polymer particles; and 0.1-5% of additives based on the total weight of the composition.

The encapsulation film composition for solar cell modules of the present invention regulates the refraction of light by means of the light diffusion mechanism of the granular polymer particles, thereby increasing the probability of the solar cell receiving light, so as to improve the light conversion efficiency of the cell.

Description of drawings

FIG. 1 is a schematic diagram of the application of the present invention to a solar cell module.

100 solar cell modules

1 transparent front panel

2 backplane

3 solar cells

4 Packaging film

Detailed ways

In order to achieve the above and other objects in the present invention, the technical means, components and functions thereof are adopted in preferred embodiments and described as follows with reference to the accompanying drawings.

As shown in Figure 1, the solar cell module packaging film composition of the present invention can be applied to a solar cell module 100, which includes: transparent resin accounting for 80% to 99% of the total weight of the composition; accounting for the composition 0.5-10% of the total weight of the granular polymer particles; and 0.1-5% of the additives of the total weight of the composition. The sum of the components in the composition is 100%. Compared with the known encapsulation film for solar cell modules, the present invention adds the granular polymer particles, uses the light diffusion mechanism to regulate the refraction of light, and then increases the probability that the solar cell receives light, so it can improve the battery life. light conversion efficiency. It will be explained in detail below.

Figure 1 is a schematic diagram of the module structure in an embodiment of the present invention. From top to bottom, there are transparent front plate (glass front plate) 1, encapsulation film 4, solar cells 3, encapsulation film 4, and back plate 2. The transparent front plate 1 , back plate 2 and packaging film 4 can effectively protect packaged components such as solar cells 3 and prevent the cells from being affected by air or moisture. The present invention mainly provides the composition of the encapsulation film 4 , so as to increase the probability that the solar cell receives light, and then improve the light conversion efficiency of the cell.

The transparent resin is the base material of the composition, accounting for 80-99% of the total weight of the composition. Materials with good light transmittance and haze can be selected, such as ethylene-vinyl acetate copolymer (EVA) resin or polyvinyl acetate. Vinyl butyral (PVB) resin or thermoplastic acrylic elastomer resin or thermoplastic polyolefin resin with high light transmittance, etc. The ethylene-vinyl acetate copolymer resin preferably contains 20-40% by weight of vinyl acetate. The thermoplastic acrylic elastomer resin is composed of a diblock (A-B) type or a triblock (A-B-A) type copolymer; its composition can be poly(formaldehyde) methylmethacrylate-b-isoprene) (poly(methylmethacrylate-b-isoprene)), poly(methylmethacrylate-b-butadiene) (poly(methylmethacrylate-b-butadiene)), Poly(methylmethacrylate-b-isoprene-b-methylmethacrylate) (poly(methylmethacrylate-b-isoprene-b-methylmethacrylate)), poly(methylmethacrylate-b-methylmethacrylate) -butadiene-b-butadiene-b-methylmethacrylate) (poly(methylmethacrylate-b-butadiene-b-methylmethacrylate)), poly(methylmethacrylate-b-butadiene-b-methylmethacrylate) Block - methyl methacrylate) (poly(methylmethacrylate-b-isoprene/butadiene-b-methylmethacrylate)), polymethylmethacrylate blocks (poly methylmethacrylate blocks) and vinyl-rich polyisoprene group Bond (a vinylbonded rich polyisoprene block). The thermoplastic acrylic elastomer resin may contain 20-60% by weight of polymethyl methacrylate (PMMA), preferably 30-50% by weight of polymethyl methacrylate.

Granular macromolecular particles are uniformly mixed in the transparent resin, accounting for 0.5-10% of the total weight of the composition, and can be acrylic macromolecules, polyacrylate resin (polyacrylate resin) and derived copolymers The composition of the polymer is better; it can be spherical particles, and the particle size is preferably between 3um and 300um. If the particle size is too high, the penetration rate will decrease. If the particle size is too low, the efficiency gain is poor. And the refractive index can be between 1.4-1.55, if the refractive index is too low, the light diffusivity will be poor. When the refractive index is too high, the transmittance decreases. The granular polymer particles have good dispersibility, and are easy to knead evenly with the transparent resin, and the phenomenon of particle aggregation is not easy to occur; and the granular polymer particles are directly kneaded with the transparent resin without additional processing procedures And equipment, can simplify process and reduce cost.

Additives are added to the transparent resin as required, accounting for 0.1-5% of the total weight of the composition, and can be various known resin accelerators, resin heat stabilizers and ultraviolet light absorbers used in solar cell module packaging materials. One or two or more of the agents are mixed, which can increase the life of the composition and improve the processability of the encapsulation process. For the convenience of description, an example is given as follows.

Resin accelerators can be peroxides such as benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1 - A mixture of one or two or more of di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, which can generate free radicals when heated to crosslink EVA, thereby making thermoplastic The transparent resin becomes thermosetting. In this way, the transparent resin after packaging will not be denatured by heat, which can effectively protect the packaged components such as solar cells and avoid being affected by air or moisture.

Resin heat stabilizer can be one or two or more mixtures in dibutyl hydroxytoluene and bis(2,2,6,6-tetrabutyl-4-piperidinyl) sebacate, which can be Stabilize the free radicals produced by EVA bond breaking due to heat or ultraviolet light, avoid these free radicals from continuing to react with the EVA skeleton and cut it into small pieces.

The ultraviolet light absorber can be one or two or more mixtures of benzophenone, benzotriazolyl, triazine and salicylate, which can convert ultraviolet light into heat energy and release it, thereby avoiding EVA is affected by ultraviolet light and causes deterioration and broken chains.

In order to make the above and other purposes, features and advantages of the present invention more understandable, the following examples are hereby described in detail:

Example 1

Get 1000g of ethylene-vinyl acetate copolymer (EVA) (available from DuPont's D250, VA content 28%) resin, insert the additive of 30g in the twin-screw kneader and carry out mixing and granulation, and then mix with 10g Granular polymer particles (purchased from Riken MX-1000, particle size 10um) were mixed and granulated in a twin-screw kneader and pressed into a film (the light transmittance of the packaging film can be measured at this time), Then take monocrystalline silicon solar cells, and use a solar simulator to measure the light conversion efficiency of the cells before packaging; Plate (glass front panel) 1, encapsulation film 4, solar cell 3, encapsulation film 4 and back plate 2, after the stacking is completed, put it into the laminator for module encapsulation, and measure it with a solar simulator after encapsulation The measured values of the light conversion efficiency of the cells after encapsulation are shown in Table 1.

Example 2

The manufacturing process of Example 2 is roughly the same as that of Example 1. The difference between it and Example 1 is that 30 g of granular polymer particles are used, and the light conversion efficiency measurements before and after battery packaging are shown in Table 1.

Example 3

Get 1000g of ethylene-vinyl acetate copolymer (EVA) (available from DuPont's D250, VA content 28%) resin, insert the additive of 30g in the twin-screw kneader and carry out mixing and granulation, and then mix with 10g The granular polymer particles (MX-3000 purchased from Riken, particle size 30um) were placed in a twin-screw kneader, kneaded and granulated and pressed to form a film, and then the monocrystalline silicon solar cells were taken and measured by a solar simulator. Measure the light conversion efficiency of the battery before packaging; after the measurement is completed, stack according to the structure of the solar cell module shown in Figure 1, in order of transparent front plate (glass front plate) 1, packaging film 4, and solar cells 3. The encapsulation film 4 and the back plate 2 are stacked and placed in a laminator for encapsulation of the module. After the encapsulation is completed, the solar simulator is used to measure the light conversion efficiency of the encapsulated cells. The measured values are shown in the table 1.

Example 4

The manufacturing process of Example 4 is roughly the same as that of Example 3. The difference between it and Example 3 is that 30 g of granular polymer particles are used.

Example 5

Get 1000g of thermoplastic acrylic elastomer resin (LA2140e purchased from Kuraray, PMMA block content 20%), and put 10g of granular polymer particles (MX-1000 purchased from Riken, particle size 10um) into a twin-screw mixer In the training machine, kneading, granulation and pressing to form a film are carried out, and then monocrystalline silicon solar cells are taken, and the light conversion efficiency before cell packaging is measured with a solar simulator; after the measurement is completed, the solar cells shown in Figure 1 The structure of the module is stacked, which is the transparent front plate (glass front plate) 1, the encapsulation film 4, the solar cell 3, the encapsulation film 4 and the back plate 2. After the stacking is completed, put it into the laminator for module assembly After the packaging is completed, the solar simulator is used to measure the light conversion efficiency of the battery after packaging, and the measured values are shown in Table 1.

Example 6

The manufacturing process of Example 6 is roughly the same as that of Example 5. The difference between it and Example 5 is that 30 g of granular polymer particles are used. Table 1 shows the light conversion efficiency measurements before and after battery packaging.

Example 7

Get 1000g of thermoplastic acrylic elastomer resin (LA2140e purchased from Kuraray, PMMA block content 20%), and put 10g of granular polymer particles (MX-300 purchased from Riken, particle size 3um) into a twin-screw mixer Mix and granulate in the training machine and press to form a film, then take polycrystalline silicon solar cells, and use a solar simulator to measure the light conversion efficiency before cell packaging; after the measurement is completed, follow the solar cell module shown in Figure 1 The structure is stacked, in order of transparent front plate (glass front plate) 1, encapsulation film 4, solar cell 3, encapsulation film 4 and back plate 2, after the stacking is completed, put it into a laminator for module encapsulation After the encapsulation is completed, the light conversion efficiency of the encapsulated cell is measured with a solar simulator, and the measured values are shown in Table 1.

Example 8

Take 1000g of acrylic resin (LA2140e purchased from Kuraray, PMMA block content 20%), and 10g of granular polymer particles (MX-3000 purchased from Riken, particle size 30um) into the twin-screw kneader Kneading, granulation and pressing to form a film, then taking polycrystalline silicon solar cells, and using a solar simulator to measure the light conversion efficiency of the cells before packaging; after the measurement is completed, stack according to the structure of the solar cell module shown in Figure 1 Stacked, in order of transparent front plate (glass front plate) 1, encapsulation film 4, solar cell 3, encapsulation film 4 and back plate 2, after the stacking is completed, put it into the laminator for module encapsulation, after encapsulation is completed Then, the photoconversion efficiency of the cells after encapsulation was measured with a solar simulator, and the measured values are shown in Table 1.

Comparative example 1

Take a commercially available EVA (KhtcEVA purchased from Guoxin Technology Co., Ltd.), and its efficiency measurement before and after packaging is shown in Table 1.

Comparative example 2

Taking a commercially available thermoplastic acrylic elastomer resin (LA2140e purchased from Kuraray, with a PMMA block content of 20%), the efficiency measurements before and after encapsulation are shown in Table 1.

Table 1

As shown in Table 1, although the conventional EVA packaging film used in Comparative Example 1 has the effect of protecting packaging components such as solar cells, after the module is packaged, the additive will absorb light sources of certain wavelengths, resulting in a decrease in the light conversion efficiency of the cell. Although comparative example 2 does not add ultraviolet light absorbers, the light conversion efficiency of the battery will not decrease, but in the examples 1 to 8 of the present invention, granular polymer particles are added to the packaging film, and the solar cell modules after packaging Compared with the comparative example, the light conversion efficiency has been significantly improved, and the power generation of the solar module after packaging has been significantly increased.

The above embodiments are only for detailed description, and are not intended to limit the present invention. Modifications and changes made by those skilled in the art to which the present invention belongs without departing from the spirit or scope of the present invention still belong to the scope of the present invention.

Claims (14)

1. A solar cell module packaging film composition, comprising: A transparent resin accounting for 80-99% of the total weight of the composition; Granular polymer particles accounting for 0.5-10% of the total weight of the composition; and additives accounting for 0.1-5% of the total weight of the composition. 2. The solar cell module packaging film composition as claimed in claim 1, wherein said transparent resin is ethylene-vinyl acetate copolymer resin or thermoplastic acrylic elastomer resin or polyvinyl butyral resin or Thermoplastic polyolefin resin with high light transmission. 3. The encapsulating film composition for solar cell modules according to claim 2, wherein the ethylene-vinyl acetate copolymer resin contains 20-40% by weight of vinyl acetate groups. 4. The encapsulating film composition for solar cell modules as claimed in claim 2, wherein said thermoplastic acrylic elastomer resin is composed of a double-stage or three-stage copolymer; its composition Can be poly(methyl methacrylate-segmented-isoprene), poly(methyl methacrylate-segmented-butadiene), poly(methyl methacrylate-segmented-isoprene -Methyl methacrylate), Poly(methyl methacrylate-Deg-butadiene-Deg-methyl methacrylate), Poly(methyl methacrylate-Deg-isoprene ene/butadiene-block-methyl methacrylate), polymethyl methacrylate groups and vinyl-rich polyisoprene group linkages. 5 . The solar cell module encapsulation film composition according to claim 4 , wherein the thermoplastic acrylic elastomer resin contains 30-50% by weight of polymethyl methacrylate. 6. The encapsulating film composition for solar cell modules according to claim 1, wherein the granular polymer particles are composed of acrylic polymers. 7. The encapsulating film composition for solar cell modules as claimed in claim 6, wherein the acrylic polymer is composed of polyacrylate resin and derived copolymer. 8 . The encapsulating film composition for solar cell modules according to claim 6 , wherein the granular polymer particles are spherical particles with a particle size between 3 um and 300 um. 9. The encapsulation film composition for solar cell modules according to claim 6, wherein the refractive index of the granular polymer particles is between 1.4-1.55. 10. The encapsulating film composition for solar cell modules according to claim 1, wherein the additive is one or more than two of a resin accelerator, a resin heat stabilizer and an ultraviolet light absorber mixed together. 11. The solar cell module encapsulation film composition according to claim 10, wherein the resin accelerator is a peroxide. 12. The solar cell module encapsulation film composition as claimed in claim 11, wherein the resin accelerator is benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5 -One or two or more of di(tert-butylperoxy)hexane and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane . 13. The encapsulating film composition for solar cell modules as claimed in claim 10, wherein the resin heat stabilizer is dibutyl hydroxytoluene, bis(2,2,6,6-tetrabutyl- 4-piperidinyl) esters or a mixture of two or more. 14. The encapsulation film composition for solar cell modules as claimed in claim 10, wherein the ultraviolet light absorber is a kind of benzophenone, benzotriazolyl, triazine series and salicylate series Or a mixture of two or more.