阅读说明：本技术 一种耐候太阳能电池背板基膜及其制备方法 (Weather-proof solar cell backboard base film and preparation method thereof ) 是由 张世明 周柯 罗春明 于 2020-03-30 设计创作，主要内容包括：本发明公开了一种耐候太阳能电池背板基膜,其特征是：由耐紫外功能树脂层和耐水解聚酯树脂层复合组成；制备方法是：制备有机紫外PET功能母料、制备耐水解PET功能母料、制备PET扩链剂功能母料、耐紫外功能树脂的挤出、耐水解聚酯树脂的挤出、挤出的物料通过分配块共挤挤出制成铸片,经双向拉伸定型冷却后,即制得耐候太阳能电池背板基膜。采用本发明,通过PET扩链剂与耐紫外聚酯树脂层和耐水解聚酯树脂层的PET聚酯产生化学反应,有效解决耐候太阳能电池背板基膜在长期户外使用过程中由于环境温度变化及紫外辐照造成的耐紫外层和耐水解层分层的问题,获得的耐候太阳能电池背板基膜性能良好,适用于太阳能光伏电池背板材料的制造。(The invention discloses a weather-resistant solar cell backboard base film, which is characterized in that: the composite material is formed by compounding an ultraviolet-resistant functional resin layer and a hydrolysis-resistant polyester resin layer; the preparation method comprises the following steps: preparing organic ultraviolet PET functional master batch, preparing hydrolysis-resistant PET functional master batch, preparing PET chain extender functional master batch, extruding ultraviolet-resistant functional resin, extruding hydrolysis-resistant polyester resin, co-extruding the extruded materials through a distribution block to prepare a casting sheet, and performing biaxial stretching, shaping and cooling to obtain the weather-resistant solar cell backboard base film. According to the invention, the PET chain extender and the PET polyester of the ultraviolet-resistant polyester resin layer and the hydrolysis-resistant polyester resin layer are subjected to chemical reaction, so that the problem of layering of the ultraviolet-resistant layer and the hydrolysis-resistant layer caused by environmental temperature change and ultraviolet irradiation in the long-term outdoor use process of the weather-resistant solar cell backboard base film is effectively solved, and the obtained weather-resistant solar cell backboard base film has good performance and is suitable for manufacturing of solar cell backboard materials.)

1. A weather-resistant solar cell backboard base film is characterized in that: the weather-resistant solar cell backboard base film is formed by compounding an ultraviolet-resistant functional resin layer and a hydrolysis-resistant polyester resin layer, and the thickness of the weather-resistant solar cell backboard base film is 125-350 mu m, wherein: the thickness of the ultraviolet-resistant functional resin layer is 20-70 μm, and the thickness of the hydrolysis-resistant polyester resin layer is 55-330 μm;

the ultraviolet-resistant functional resin layer is prepared by mixing, melting and extruding 55-89% of polyethylene glycol terephthalate resin, 5-40% of rutile type titanium dioxide master batch and 5-20% of organic ultraviolet PET functional master batch by mass percentage;

the organic ultraviolet PET functional master batch is prepared by mixing, melting and extruding 70-90% of polyethylene terephthalate resin and 10-30% of organic ultraviolet absorbent in percentage by mass; the organic ultraviolet absorbent is one or a mixture of two of UV-234, UV-360, UV-1577 and UV-3638F;

the hydrolysis-resistant polyester resin layer is prepared by mixing, melting and extruding 50-89% of polyethylene terephthalate resin, 10-40% of hydrolysis-resistant PET functional master batch and 1-10% of PET chain extender functional master batch by mass percentage;

the hydrolysis-resistant PET functional master batch is prepared by mixing, melting, extruding and granulating 80-90% of polyethylene terephthalate resin and 10-20% of carbodiimide hydrolysis-resistant agent in percentage by mass;

the PET chain extender functional master batch is prepared by mixing, melting and extruding 90-99% of polyethylene terephthalate resin and 1-10% of chain extender in percentage by mass; the chain extender is an epoxy chain extender.

2. The weatherable solar cell backsheet base film according to claim 1, wherein: the weather-resistant solar cell backboard base film is formed by compounding an ultraviolet-resistant functional resin layer and a hydrolysis-resistant polyester resin layer, and comprises the following components in parts by weight: the ultraviolet-resistant functional resin and the hydrolysis-resistant polyester resin are respectively extruded by an extruder, then are co-extruded by a distribution block, and then are subjected to biaxial tension to obtain the polyester resin.

3. The weatherable solar cell backsheet base film according to claim 1 or 2, wherein: the polyethylene terephthalate resin is a polyethylene terephthalate resin having an intrinsic viscosity of 0.60dl/g to 0.85 dl/g.

4. The weatherable solar cell backsheet base film according to claim 1 or 2, wherein: the rutile type titanium dioxide master batch is a rutile type titanium dioxide master batch which takes polyethylene terephthalate resin sold in China chemical industry markets as a base material.

5. The weatherable solar cell backsheet base film according to claim 1 or 2, wherein: the polyethylene terephthalate resin is any one of film-grade PET resins FG600, FG610, FG720 and FG760 produced and provided by China petrochemical characterization chemical fiber Limited liability company.

6. The weatherable solar cell backsheet base film according to claim 1 or 2, wherein: the epoxy chain extender is one or a mixture of two of epoxy chain extenders of ADR4370S, ADR4400F and ADR4468 provided by German Bassfungs company;

the carbodiimide hydrolysis resistant agent is one or two of monomeric/polymeric carbodiimide Stabaxol I, Stabaxol P100, Stabaxol P200 and Stabaxol P400 produced by Rhine chemical Lenao Co., Ltd.

7. A preparation method of a weather-resistant solar cell backboard base film is characterized by comprising the following steps:

a. preparing an organic ultraviolet PET functional master batch:

taking 70-90% of polyethylene terephthalate resin and 10-30% of organic ultraviolet absorbent according to the mass percentage, uniformly mixing the polyethylene terephthalate resin and the organic ultraviolet absorbent to obtain a mixture, and performing melt extrusion and granulation at the temperature of 215-255 ℃ through a double-screw extruder to obtain organic ultraviolet PET functional master batch for later use;

the organic ultraviolet absorbent is one or a mixture of two of organic ultraviolet absorbents with product types of UV-234, UV-360, UV-1577 and UV-3638F;

b. preparing hydrolysis-resistant PET functional master batch:

taking the polyethylene terephthalate resin and the carbodiimide hydrolysis resistant agent according to the mass percent of 80-90% of the polyethylene terephthalate resin and 10-20% of the carbodiimide hydrolysis resistant agent, uniformly mixing, drying at the temperature of 110-130 ℃ for 1-2 h, and then performing melt extrusion and granulation at the temperature of 235-275 ℃ through a double screw extruder to obtain the hydrolysis-resistant PET functional master batch for later use;

c. preparing a PET chain extender functional master batch:

taking the polyethylene terephthalate resin and the chain extender according to the mass percent of 90-99% of the polyethylene terephthalate resin and 1-10% of the chain extender, uniformly mixing to obtain a mixture, and then carrying out melt extrusion and granulation at the temperature of 215-255 ℃ through a double-screw extruder to obtain the PET chain extender functional master batch for later use;

the chain extender is an epoxy chain extender;

d. preparing a weather-resistant solar cell backboard base film:

(a) extruding ultraviolet-resistant functional resin: taking 55-89% of polyethylene terephthalate resin, 5-40% of rutile type titanium dioxide master batch and 5-20% of organic ultraviolet PET functional master batch by mass percent, drying the polyethylene terephthalate resin, the rutile type titanium dioxide master batch and the organic ultraviolet PET functional master batch at the temperature of 150-170 ℃ for 2-4 h, mixing by an extruder I, and then melting and extruding at the temperature of 265-285 ℃;

(b) extrusion of hydrolysis-resistant polyester resin: taking the polyethylene terephthalate resin, the hydrolysis-resistant PET functional master batch and the PET chain extender functional master batch according to the mass percentages of 50-89% of polyethylene terephthalate resin, 10-40% of hydrolysis-resistant PET functional master batch and 1-10% of PET chain extender functional master batch, drying the polyethylene terephthalate resin, the hydrolysis-resistant PET functional master batch and the PET chain extender functional master batch at the temperature of 150-170 ℃ for 2-4 h, mixing the materials by an extruder II, and then melting and extruding the materials at the temperature of 265-285 ℃;

(c) preparing a weather-resistant solar cell backboard base film: after the materials extruded by the extruder I and the extruder II are extruded by the material distribution block in a double-layer co-extrusion way, making the mixture flow through a cold drum at the temperature of 15-20 ℃ to prepare a cast sheet, longitudinally stretching the cast sheet at the temperature of 70-80 ℃ for 2.5-3.5 times, then cooling the film to 15-20 ℃ after 1-5 s, then transversely stretching the film for 2.5-3.5 times at the temperature of 110-130 ℃, enabling the biaxially stretched film to enter an electric heating channel heat setting area, wherein the temperature of the first zone is 205-230 ℃, the temperature of the second zone is 205-230 ℃, the temperature of the third zone is 205-230 ℃, the temperature of the fourth zone is 205-230 ℃, the temperature of the fifth zone is 175-200 ℃, the temperature of the sixth zone is 140-160 ℃, the heat setting time of the film is 8-120 s, the film passing through the heat setting zone is cooled at 60-70 ℃, the time of the film is 1-20 s and the room temperature, and then the film is rolled, thus obtaining the weather-resistant solar cell backboard base film.

8. The method of making a weatherable solar cell backplane base film according to claim 7, wherein: the polyethylene terephthalate resin is a polyethylene terephthalate resin having an intrinsic viscosity of 0.60dl/g to 0.85 dl/g.

9. The method for preparing the weatherable solar cell back sheet base film according to claim 7 or 8, wherein: the rutile type titanium dioxide master batch is a rutile type titanium dioxide master batch which takes polyethylene terephthalate resin sold in China chemical industry markets as a base material.

10. The method for preparing the weatherable solar cell back sheet base film according to claim 7 or 8, wherein: the polyethylene terephthalate resin is any one of film-grade PET resins FG600, FG610, FG720 and FG760 produced and provided by China petrochemical characterization chemical fiber Limited liability company;

the epoxy chain extender is one or a mixture of two of epoxy chain extenders with product types of ADR4370S, ADR4400F and ADR4468 provided by German Bassfungs company;

the carbodiimide hydrolysis resistant agent is one or two of monomeric/polymeric carbodiimide Stabaxol I, Stabaxol P100, Stabaxol P200 and Stabaxol P400 produced by Rhine chemical Lenao Co., Ltd.

Technical Field

The invention belongs to an organic high molecular compound and preparation thereof, relates to a functional film taking polyester as a material and preparation thereof, and particularly relates to a weather-resistant solar cell backboard base film and a preparation method thereof. The weather-proof solar cell backboard base film is suitable for manufacturing solar photovoltaic cell backboard materials.

Background

With the development of the solar photovoltaic industry in recent years, the solar cell back plate with the structure of the fluorine film + the PET (polyethylene terephthalate) film + the fluorine film (TPT for short) becomes one of the mainstream solar cell back plates at present, and as the global fluorine film suppliers only have a few manufacturers such as DuPont, Japan Asahi glass, French Acoma and the like, the price of the fluorine film is high; meanwhile, the difficulty in degradation and environmental pollution of the fluorine film have led to the issue of controversy in research on weather-resistant PET films that can replace the fluorine film. The current technical development trend of weather-resistant PET for solar cell back panels mainly centers on both ultraviolet resistance and hydrolysis resistance.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a weather-resistant solar cell backboard base film and a preparation method thereof. In the preparation of the weather-resistant solar cell back plate base film, an A/B two-layer structure is adopted (the layer A is an ultraviolet-resistant functional resin layer, the layer B is a hydrolysis-resistant polyester resin layer), namely, the ultraviolet resistance of the layer A and the hydrolysis resistance of the layer B are endowed, and in the extrusion film-making process, the PET chain extension master batch is added into the hydrolysis-resistant polyester resin layer, so that the PET chain extension master batch and the polyester resin of the ultraviolet-resistant layer and the hydrolysis-resistant layer are subjected to chemical reaction, the bonding force between the ultraviolet-resistant layer and the hydrolysis-resistant layer is greatly enhanced, the problem that the ultraviolet-resistant layer and the hydrolysis-resistant layer are layered due to the change of environmental temperature and ultraviolet irradiation in the long-term outdoor use process of the weather-resistant solar cell back plate base film is solved, and the weather-.

The content of the invention is as follows: a weather-resistant solar cell backboard base film is characterized in that: the weather-resistant solar cell backboard base film is formed by compounding an ultraviolet-resistant functional resin layer (A layer) and a hydrolysis-resistant polyester resin layer (B layer) (namely an A layer/B layer structure), and has the thickness of 125-350 mu m, wherein: the thickness of the ultraviolet-resistant functional resin layer (layer A) is 20-70 μm, and the thickness of the hydrolysis-resistant polyester resin layer (layer B) is 55-330 μm;

the ultraviolet-resistant functional resin layer is prepared by mixing, melting and extruding 55-89 wt% of polyethylene terephthalate resin, 5-40 wt% of rutile titanium dioxide master batch and 5-20 wt% of organic ultraviolet PET (PET is polyethylene terephthalate, and the same later) functional master batch;

the organic ultraviolet PET functional master batch is prepared by mixing, melting and extruding 70-90% of polyethylene terephthalate resin and 10-30% of organic ultraviolet absorbent in percentage by mass; the organic ultraviolet absorbent is one or a mixture of two of UV-234, UV-360, UV-1577 and UV-3638F, and the organic ultraviolet absorbents are common products in the chemical industry market of China;

the hydrolysis-resistant polyester resin layer is prepared by mixing, melting and extruding 50-89% of polyethylene terephthalate resin, 10-40% of hydrolysis-resistant PET functional master batch and 1-10% of PET chain extender functional master batch by mass percentage;

the hydrolysis-resistant PET functional master batch is prepared by mixing, melting, extruding and granulating 80-90% of polyethylene terephthalate resin and 10-20% of carbodiimide hydrolysis-resistant agent in percentage by mass;

the PET chain extender functional master batch is prepared by mixing, melting and extruding 90-99% of polyethylene terephthalate resin and 1-10% of chain extender in percentage by mass; the chain extender is an epoxy (polymer) chain extender.

The invention comprises the following steps: the weather-resistant solar cell backboard base film is formed by compounding an ultraviolet-resistant functional resin layer (A layer) and a hydrolysis-resistant polyester resin layer (B layer) and comprises the following components in parts by weight: the ultraviolet-resistant functional resin and the hydrolysis-resistant polyester resin are respectively extruded by an extruder, then are co-extruded by a distribution block, and then are subjected to biaxial tension to obtain the polyester resin.

The invention comprises the following steps: the polyethylene terephthalate resin is preferably a polyethylene terephthalate resin having an intrinsic viscosity of 0.60dl/g to 0.85 dl/g.

The invention comprises the following steps: the rutile type titanium dioxide master batch is the rutile type titanium dioxide master batch (with the mass percentage concentration of 60%) which takes polyethylene terephthalate resin (PET) sold in the chemical industry market of China as a base material.

The invention comprises the following steps: the polyethylene terephthalate resin is preferably any one of film-grade PET resins FG600, FG610, FG720 and FG760 produced and provided by China petrochemical chemical characterization chemical fiber Limited liability company, and can also be other commercially available products.

The invention comprises the following steps: the epoxy (polymer) chain extender can be any one or a mixture of two of epoxy (polymer) chain extenders with the product types of ADR4370S, ADR4400F and ADR4468 provided by BASF (BASF for short);

the invention comprises the following steps: the carbodiimide hydrolysis-resistant agent can be any one or a mixture of two of monomeric/polymeric carbodiimide Stabaxol I, Stabaxol P100, Stabaxol P200 and Stabaxol P400, which are produced by Leanen chemical Leanen GmbH of Germany.

Another aspect of the invention is: a preparation method of a weather-resistant solar cell backboard base film is characterized by comprising the following steps:

a. preparing an organic ultraviolet PET functional master batch:

taking 70-90% of polyethylene terephthalate resin (PET polyester for short) and 10-30% of organic ultraviolet absorbent according to the mass percentage, uniformly mixing the polyethylene terephthalate resin (PET polyester for short) and the organic ultraviolet absorbent (in a bin) to obtain a mixture, and performing melt extrusion and granulation at the temperature of 215-255 ℃ by using a double-screw extruder to obtain organic ultraviolet PET functional master batch for later use;

the organic ultraviolet absorbent is one or a mixture of two of organic ultraviolet absorbents with product types of UV-234, UV-360, UV-1577 and UV-3638F, and the organic ultraviolet absorbents are common products in the chemical industry market of China;

b. preparing hydrolysis-resistant PET functional master batch:

taking and uniformly mixing 80-90% of polyethylene terephthalate resin (PET polyester for short) and 10-20% of carbodiimide hydrolysis resistant agent by mass percent, drying the mixture for 1-2 h by a dryer at the temperature of 110-130 ℃, and then performing melt extrusion and granulation by a double-screw extruder at the temperature of 235-275 ℃ to obtain hydrolysis-resistant PET functional master batch for later use;

c. preparing a PET chain extender functional master batch:

taking polyethylene terephthalate resin and a chain extender according to the mass percentage of 90-99 percent (PET polyester for short) and 1-10 percent of the chain extender, uniformly mixing the polyethylene terephthalate resin and the chain extender (in a storage bin) to obtain a mixture, and then carrying out melt extrusion and granulation by a double-screw extruder at the temperature of 215-255 ℃ to obtain the PET chain extender functional master batch for later use; the chain extender is an epoxy (polymer) chain extender;

d. preparing a weather-resistant solar cell backboard base film:

(a) extrusion of ultraviolet-resistant functional resin [ i.e. ultraviolet-resistant functional resin layer, or ultraviolet-resistant polyester resin (ultraviolet-resistant polyester resin layer) ]: taking 55-89% of polyethylene terephthalate resin, 5-40% of rutile type titanium dioxide master batch and 5-20% of organic ultraviolet PET functional master batch by mass percent, drying the polyethylene terephthalate resin, the rutile type titanium dioxide master batch and the organic ultraviolet PET functional master batch at the temperature of 150-170 ℃ (drying) for 2-4 h, mixing by an extruder I, and then melting and extruding at the temperature of 265-285 ℃;

(b) extrusion of hydrolysis-resistant polyester resin (i.e., hydrolysis-resistant polyester resin layer): taking polyethylene terephthalate resin, hydrolysis-resistant PET functional master batch and PET chain extender functional master batch according to the mass percent of 50-89% of polyethylene terephthalate resin, 10-40% of hydrolysis-resistant PET functional master batch and 1-10% of PET chain extender functional master batch, drying for 2-4 h at (drying) temperature of 150-170 ℃, mixing by an extruder II, and then performing melt extrusion at 265-285 ℃;

(c) preparing a weather-resistant solar cell backboard base film: after the materials extruded by the extruder I and the extruder II are extruded by the material distribution block in a double-layer co-extrusion way, making the mixture flow through a cold drum at the temperature of 15-20 ℃ to prepare a cast sheet, longitudinally stretching the cast sheet at the temperature of 70-80 ℃ for 2.5-3.5 times, then cooling to 15-20 ℃ after 1-5 s(s), then transversely stretching for 2.5-3.5 times at the temperature of 110-130 ℃, enabling the biaxially oriented film to enter an electric heating channel heat setting area, wherein the temperature of the first zone is 205-230 ℃, the temperature of the second zone is 205-230 ℃, the temperature of the third zone is 205-230 ℃, the temperature of the fourth zone is 205-230 ℃, the temperature of the fifth zone is 175-200 ℃, the temperature of the sixth zone is 140-160 ℃, the heat setting time of the film is 8-120 s, the film passing through the heat setting zone is cooled at 60-70 ℃, the time of the film is 1-20 s and the room temperature, and then the film is rolled, thus obtaining the weather-resistant solar cell backboard base film (or the weather-resistant solar cell photovoltaic backboard base film).

In another aspect of the invention: the polyethylene terephthalate resin is preferably a polyethylene terephthalate resin having an intrinsic viscosity of 0.60dl/g to 0.85 dl/g.

In another aspect of the invention: the rutile type titanium dioxide master batch is the rutile type titanium dioxide master batch (with the mass percentage concentration of 60%) which takes polyethylene terephthalate resin (PET) sold in the chemical industry market of China as a base material.

In another aspect of the invention: the polyethylene terephthalate resin is preferably any one of film-grade PET resins FG600, FG610, FG720 and FG760 produced and provided by China petrochemical chemical characterization chemical fiber Limited liability company, and can also be other commercially available products;

in another aspect of the invention: the epoxy (polymer) chain extender can be any one or a mixture of two of epoxy (polymer) chain extenders with product types of ADR4370S, ADR4400F and ADR4468 provided by BASF (BASF for short);

in another aspect of the invention: the carbodiimide hydrolysis-resistant agent can be any one or a mixture of two of monomeric/polymeric carbodiimide Stabaxol I, Stabaxol P100, Stabaxol P200 and Stabaxol P400, which are produced by Leanen chemical Leanen GmbH of Germany.

Compared with the prior art, the invention has the following characteristics and beneficial effects:

(1) by adopting the preparation method, the core key point of preparing the base film of the back plate of the weather-resistant solar cell (photovoltaic) is that the PET chain extender and the PET polyester of the ultraviolet-resistant polyester resin layer and the hydrolysis-resistant polyester resin layer are subjected to chemical reaction, so that the problem of layering caused by long-term damp-heat aging and ultraviolet aging of the ultraviolet-resistant polyester resin layer and the hydrolysis-resistant polyester resin layer is effectively solved;

(2) by adopting the preparation method, in the preparation method of the weather-resistant solar cell (photovoltaic) backboard base film, the viscosity and the molecular weight of PET are improved by the PET chain extender, so that the water vapor transmission rate of the photovoltaic backboard base film can be reduced excellently; through the test: the water vapor transmission rate of the basal membrane with the thickness of 125-350 mu m is 0.8g/m under the test environment of 38 ℃ and 90 percent RH (RH: relative humidity)²·24h～2.5g/m²24h (infrared method);

(3) by adopting the preparation method of the base film of the weather-resistant solar cell (photovoltaic) backboard, the ultraviolet performance of the base film of the backboard can be greatly enhanced due to the high content of the inorganic additive in the ultraviolet-resistant polyester resin layer and the auxiliary double ultraviolet function of the organic ultraviolet absorbent, and tests show that: aging the base film with the thickness of 125-350 mu m by ultraviolet light for 300kW.h/m²Then, the yellow index change value (delta b) is 0.5-3;

(4) by adopting the preparation method, because the anti-hydrolysis agent, the chain extender and the PET polyester resin are blended, the terminal carboxyl group of the PET resin is reduced, and the anti-hydrolysis performance of the PET backboard base film is greatly improved; the retention rate of the elongation at break of the film reaches more than 50% after the base film is cooked at the high temperature of 121 ℃ and 2MPa for 60 hours, so that the moisture and heat resistance of the base film of the PET backboard can be effectively improved;

(5) the weather-resistant solar cell (photovoltaic) backboard base film is subjected to cold-heat cycle treatment for 3000h (6 h/cycle, 500 cycles) at 85 ℃ and 85% RH (RH: relative humidity) and 40-85 ℃, the end face (thickness direction) of the backboard base film is observed by amplifying and co-extruding with an optical imager, a UV-resistant layer and a hydrolysis-resistant layer are not separated, and the backboard base film has no powder falling, cracks and the like; ultraviolet aging of 300kW.h/m²The end face (thickness direction) of the back plate base film is observed by amplifying and co-extruding through an optical imager, the ultraviolet-resistant layer and the hydrolysis-resistant layer are not separated, the back plate base film does not have powder falling, cracks and the like, and the performance is excellent;

(6) the preparation process of the weather-resistant solar cell (photovoltaic) backboard base film product is simple, the working procedure is simple and convenient, the operation is easy, and the practicability is high.

Detailed Description

The following examples are intended to further illustrate the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims appended hereto.