Flexible copolymerized polyester solar cell backboard film and preparation method thereof

Abstract

The invention provides a flexible copolymerized polyester solar cell backboard film. The backboard film comprises a core layer and surface layers compounded on the upper surface and the lower surface of the core layer, the surface layer comprises the following raw material components: polyethylene glycol terephthalate A, polytrimethylene terephthalate and a functional master batch A; and the core layer comprises the following raw material components: polyethylene glycol terephthalate B, nano titanium dioxide and a functional master batch B. According to the flexible copolymerized polyester solar cell backboard film and the preparation method thereof, the anti-hydrolysis agent is added into the raw materials of the backboard film, so that the functional group-N = C = N-and the terminal carboxyl group generate stable ureide, and the hydrolysis resistance of the backboard film is improved. The surface layer comprises the following raw material components: polyethylene glycol terephthalate A and polytrimethylene terephthalate, the crystalline structures of the two components are different, and the properties such as water vapor permeability and thermal shrinkage rate of the backboard film are remarkably improved by compounding use of the two components.

Description

Technical Field

[0001] The invention belongs to the field of solar cells, and in particular relates to a flexible copolyester solar cell backplane film and a preparation method thereof. Background Art

[0002] The application of solar cells has expanded from military and aerospace fields to industry, commerce, agriculture, communications, household appliances, and public utilities. They are particularly suitable for decentralized deployment in remote areas, high mountains, deserts, islands, and rural areas, saving on expensive transmission lines. In the long term, with improvements in solar cell manufacturing technology and the invention of new photoelectric-to-electricity conversion devices, coupled with global environmental protection and the enormous demand for renewable clean energy, solar cells will continue to be a relatively viable method for utilizing solar radiation, opening up broad prospects for the future large-scale utilization of solar energy. A solar cell is a thin photovoltaic semiconductor wafer that directly generates electricity from sunlight. Once exposed to light that meets certain illumination conditions, it can instantly output voltage and, in the presence of a circuit, generate current. The solar cell backsheet film, located on the back of the solar panel, provides protection and support for the cells and requires reliable insulation, water resistance, and aging resistance. However, existing solar cell backsheet films exhibit unsatisfactory aging resistance, a problem that urgently needs to be addressed. Summary of the Invention

[0003] In order to solve the above problems, one aspect of the present invention provides a flexible copolyester solar cell backplane film and a preparation method thereof, characterized in that the backplane film includes a core layer and a surface layer composited on the upper and lower surfaces of the core layer; the raw material components of the surface layer include: polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A; the raw material components of the core layer include: polyethylene terephthalate B, nano titanium dioxide and functional masterbatch B.

[0004] Preferably, by weight, the raw material components of the surface layer include: 20-80 parts of polyethylene terephthalate A, 30-50 parts of polypropylene terephthalate, and 5-10 parts of functional masterbatch A; the raw material components of the core layer include: 60-80 parts of polyethylene terephthalate B and 10-20 parts of functional masterbatch B.

[0005] Preferably, the functional masterbatch A is prepared by high-speed mixing and melt granulation of polyethylene terephthalate A powder, pigment A and additive A; the functional masterbatch B is prepared by high-speed mixing and melt granulation of polyethylene terephthalate B powder, pigment B and additive B.

[0006] Preferably, the pigment A and the pigment B both include titanium dioxide, and further include one or more of zinc oxide, calcium carbonate, barium sulfate, and zirconium oxide.

[0007] Preferably, the auxiliary agent A and the auxiliary agent B both include an anti-hydrolysis agent, an antioxidant and a light stabilizer.

[0008] Preferably, the anti-hydrolysis agent is selected from one or more of Stabaxol 1, Stabaxol P, Stabaxol P100, Stabaxol P200, and Stabaxol P400.

[0009] Preferably, the anti-hydrolysis agent is Stabaxol 1.

[0010] Preferably, the antioxidant is selected from one or more of antioxidant 1076, antioxidant B215, antioxidant B900, and antioxidant 264.

[0011] Preferably, the light stabilizer is selected from one or more of light stabilizer 770, light stabilizer 292, and light stabilizer 944.

[0012] Preferably, the light stabilizer is light stabilizer 770.

[0013] Preferably, the viscosity of the polyethylene terephthalate is 0.82-0.89 dL / g.

[0014] Preferably, the viscosity of the polyethylene terephthalate is 0.85 dL / g.

[0015] Preferably, the weight ratio of polyethylene terephthalate, polypropylene terephthalate and functional masterbatch A is 50:40:7.

[0016] The second aspect of the present invention provides a method for preparing the flexible copolyester solar cell backsheet film, the method specifically comprising:

[0017] The vacuum-dried polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A are supplied to the A-layer extruder, while the vacuum-dried polyethylene terephthalate B and functional masterbatch B are supplied to the B-layer extruder. They are co-extruded into films, and then stretched longitudinally and transversely and heat-set simultaneously to obtain the backsheet film.

[0018] Compared with the prior art, the present invention offers the following advantages and benefits: It provides a flexible copolyester solar cell backsheet film and a method for preparing the same. The backsheet film's raw materials include an anti-hydrolysis agent, preferably Stabaxol 1 from Rhein Chemie, Germany, which allows the functional group -N=C=N- to react with the terminal carboxyl group to form a stable urea, thereby improving the backsheet film's hydrolysis resistance. The surface layer of the present invention comprises polyethylene terephthalate and polytrimethylene terephthalate, each with different crystalline structures. Their combined use significantly improves the backsheet film's water vapor transmission rate, thermal shrinkage, and other properties. DETAILED DESCRIPTION

[0019] The present invention can be further understood by referring to the following detailed description of the preferred embodiments of the present invention and the included Examples. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those generally understood by those of ordinary skill in the art to which this application belongs. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0020] The raw materials used in the present invention were purchased from the following manufacturers:

[0021] Dimethyl terephthalate: Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0022] Ethylene glycol: Qingdao Aorida Chemical and Electrical Co., Ltd.;

[0023] Antioxidant 1076: Yixing Angel Synthetic Chemical Co., Ltd.

[0024] Light stabilizer 770: Yixing Angel Synthetic Chemical Co., Ltd.

[0025] Polytrimethylene terephthalate: Changchun, Taiwan, China 3010-104XZ;

[0026] Stabaxol 1: German Rhein Chemie;

[0027] Stabaxol P: Rhein Chemie, Germany;

[0028] The present invention provides a flexible copolyester solar cell backplane film, which comprises a core layer and a surface layer composited on the upper and lower surfaces of the core layer; the raw material components of the surface layer include: polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A; the raw material components of the core layer include: polyethylene terephthalate B and functional masterbatch B.

[0029] Preferably, by weight, the raw material components of the surface layer include: 20-80 parts of polyethylene terephthalate A, 30-50 parts of polypropylene terephthalate, and 5-10 parts of functional masterbatch A; the raw material components of the core layer include: 60-80 parts of polyethylene terephthalate B and 10-20 parts of functional masterbatch B.

[0030] Preferably, the functional masterbatch A is prepared by high-speed mixing and melt granulation of polyethylene terephthalate A powder, pigment A and additive A; the functional masterbatch B is prepared by high-speed mixing and melt granulation of polyethylene terephthalate B powder, pigment B and additive B.

[0031] Preferably, the pigment A and the pigment B both include titanium dioxide, and further include one or more of zinc oxide, calcium carbonate, barium sulfate, and zirconium oxide.

[0032] Preferably, the auxiliary agent A and the auxiliary agent B both include an anti-hydrolysis agent, an antioxidant and a light stabilizer.

[0033] Preferably, the anti-hydrolysis agent is selected from one or more of Stabaxol 1, Stabaxol P, Stabaxol P100, Stabaxol P200, and Stabaxol P400.

[0034] Preferably, the anti-hydrolysis agent is Stabaxol 1.

[0035] Preferably, the antioxidant is selected from one or more of antioxidant 1076, antioxidant B215, antioxidant B900, and antioxidant 264.

[0036] Preferably, the light stabilizer is selected from one or more of light stabilizer 770, light stabilizer 292, and light stabilizer 944.

[0037] Preferably, the light stabilizer is light stabilizer 770.

[0038] Preferably, the viscosity of the polyethylene terephthalate is 0.82-0.89 dL / g.

[0039] Preferably, the viscosity of the polyethylene terephthalate is 0.85 dL / g.

[0040] Preferably, the weight ratio of polyethylene terephthalate, polypropylene terephthalate and functional masterbatch A is 50:40:7.

[0041] The second aspect of the present invention provides a method for preparing the flexible copolyester solar cell backsheet film, the method specifically comprising:

[0042] The vacuum-dried polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A are supplied to the A-layer extruder, while the vacuum-dried polyethylene terephthalate B and functional masterbatch B are supplied to the B-layer extruder. They are co-extruded into films, and then stretched longitudinally and transversely and heat-set simultaneously to obtain the backsheet film.

[0043] Compared to existing technologies, the present invention provides a flexible copolyester solar cell backsheet film and its preparation method. The backsheet film's raw materials include an anti-hydrolysis agent, preferably Stabaxol 1 from Rhein Chemie, Germany. This stabilizes the functional group -N=C=N- and the terminal carboxyl groups to form a stable urea, thereby improving the backsheet film's hydrolysis resistance. The surface layer of the present invention comprises polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT). These two components have different crystalline structures, and their combined use significantly improves the backsheet film's water vapor transmission rate (WVT) and thermal shrinkage.

[0044] Example 1

[0045] The preparation of polyethylene terephthalate A and polyethylene terephthalate B is the same, both are:

[0046] Using dimethyl terephthalate and ethylene glycol as raw materials, a polymerization catalyst, germanium oxide, was added to carry out a polycondensation reaction to obtain polyethylene terephthalate I with a viscosity of 0.65 dL / g and a carboxyl terminal group number of 19 mol / t.

[0047] The obtained polyethylene terephthalate I was dried at 180°C for 6 hours to remove moisture and crystallize, and then solid-phase polymerized at 230°C and a vacuum degree of 0.3 atmospheres for 9 hours to obtain polyethylene terephthalate II with an intrinsic viscosity of 0.85 dL / g.

[0048] The preparation of functional masterbatch A and functional masterbatch B is the same, specifically:

[0049] 80 parts by weight of polyethylene terephthalate A or polyethylene terephthalate B powder, 5 parts of titanium dioxide, 5 parts of zinc oxide, 10,763 parts of an antioxidant, and 7,702 parts of a light stabilizer are mixed and dispersed uniformly in a high-speed mixer, and then extruded and granulated using a twin-screw granulator. Simultaneously, 15 parts of Stabaxol is added to the extruder through the exhaust port of the twin-screw using a screw pump to granulate. The granules are dried at 120°C for 4 hours to remove moisture, and then sealed and packaged.

[0050] Backsheet film preparation method:

[0051] Polyethylene terephthalate II, polypropylene terephthalate and functional masterbatch A which had been vacuum dried at 165°C for 6 hours were supplied to the A-layer extruder in a weight ratio of 50:40:7. At the same time, polyethylene terephthalate II which had been vacuum dried at 165°C for 6 hours and functional masterbatch B were supplied to the B-layer extruder in a weight ratio of 70:15. They were co-extruded into films at 270°C, and then stretched longitudinally and transversely at 100°C, and heat-set at 220°C to obtain a backsheet film.

[0052] Example 2

[0053] The difference between this embodiment and embodiment 2 lies in the preparation of polyethylene terephthalate A and polyethylene terephthalate B. The preparation methods of polyethylene terephthalate A and polyethylene terephthalate B in this embodiment are the same, specifically:

[0054] Dimethyl terephthalate and ethylene glycol were used as raw materials, and germanium oxide was added as a polymerization catalyst to carry out a polycondensation reaction to obtain polyethylene terephthalate particles I having a viscosity of 0.65 dL / g.

[0055] The obtained polyethylene terephthalate I was dried at 180°C for 6 hours to remove moisture and crystallize, and then solid-phase polymerized at 230°C and a vacuum degree of 0.3 atmospheres for 11 hours to obtain polyethylene terephthalate III with an intrinsic viscosity of 0.89 dL / g.

[0056] Backsheet film preparation method:

[0057] Polyethylene terephthalate III, polypropylene terephthalate and functional masterbatch A which had been vacuum dried at 165°C for 6 hours were supplied to the A-layer extruder in a weight ratio of 50:40:7. At the same time, polyethylene terephthalate III which had been vacuum dried at 165°C for 6 hours and functional masterbatch B were supplied to the B-layer extruder in a weight ratio of 70:15. They were co-extruded into films at 270°C, and then stretched longitudinally and transversely at 100°C, and heat-set at 220°C to obtain a backsheet film.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 1 lies in the preparation method of functional masterbatch A and functional masterbatch B.

[0060] The preparation methods of functional masterbatch A and functional masterbatch B in this embodiment are the same, both of which are:

[0061] 80 parts by weight of polyethylene terephthalate A or polyethylene terephthalate B powder, 5 parts of titanium dioxide, 5 parts of zinc oxide, 10,763 parts of an antioxidant, and 7,702 parts of a light stabilizer were mixed and dispersed uniformly in a high-speed mixer, and then extruded and granulated using a twin-screw granulator. Simultaneously, 5 parts of Stabaxol P was added to the extruder through the exhaust port of the twin-screw using a screw pump for granulation. The granules were dried at 120° C. for 4 hours to remove moisture, and then sealed and packaged.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 lies in the preparation of polyethylene terephthalate A and polyethylene terephthalate B. The preparation methods of polyethylene terephthalate A and polyethylene terephthalate B in this comparative example are the same, specifically:

[0064] Dimethyl terephthalate and ethylene glycol were used as raw materials, and germanium oxide was added as a polymerization catalyst to carry out a polycondensation reaction to obtain polyethylene terephthalate particles I having a viscosity of 0.65 dL / g.

[0065] The obtained polyethylene terephthalate I was dried at 180°C for 6 hours to remove moisture and crystallize, and then solid-phase polymerized at 230°C and a vacuum degree of 0.3 atmospheres for 15 hours to obtain polyethylene terephthalate IV with an intrinsic viscosity of 0.96 dL / g.

[0066] Backsheet film preparation method:

[0067] Polyethylene terephthalate IV, polypropylene terephthalate and functional masterbatch A which had been vacuum dried at 165°C for 6 hours were supplied to the A-layer extruder in a weight ratio of 50:40:7. At the same time, polyethylene terephthalate IV which had been vacuum dried at 165°C for 6 hours and functional masterbatch B were supplied to the B-layer extruder in a weight ratio of 70:15. The films were co-extruded at 270°C, stretched longitudinally and transversely at 100°C, and heat-set at 220°C to obtain the backsheet film.

[0068] Comparative Example 2

[0069] The difference between this comparative example and Example 1 is:

[0070] Backsheet film preparation method:

[0071] Polyethylene terephthalate II and functional masterbatch A, which had been vacuum-dried at 165°C for 6 hours, were supplied to the A-layer extruder in a weight ratio of 50:7. Meanwhile, polyethylene terephthalate II and functional masterbatch B, which had been vacuum-dried at 165°C for 6 hours, were supplied to the B-layer extruder in a weight ratio of 70:15. The films were co-extruded at 270°C, stretched longitudinally and transversely at 100°C, and heat-set at 220°C to obtain the backsheet film.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 1 is:

[0074] Backsheet film preparation method:

[0075] Polyethylene terephthalate II, polypropylene terephthalate and functional masterbatch A which were vacuum dried at 165°C for 6 hours were supplied to the A layer extruder in a weight ratio of 50:20:7. At the same time, polyethylene terephthalate II which were vacuum dried at 165°C for 6 hours and functional masterbatch B were supplied to the B layer extruder in a weight ratio of 70:15. They were co-extruded into films at 270°C, and then stretched longitudinally and transversely at 100°C, and heat-set at 220°C to obtain the backsheet film.

[0076] Performance Testing

[0077] The properties of the backsheet films of Examples 1-3 and Comparative Examples 1-3 were measured, and the results are shown in Table 1.

[0078] Table 1. Performance test results

[0079]

[0080]

[0081] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A flexible copolyester solar cell backsheet film, characterized in that: The backboard film includes a core layer and a surface layer composited on the upper and lower surfaces of the core layer; the raw material components of the surface layer include: polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A; the raw material components of the core layer include: polyethylene terephthalate B, nano titanium dioxide and functional masterbatch B.

2. The flexible copolyester solar cell backsheet film according to claim 1, characterized in that: By weight, the raw material components of the surface layer include: 20-80 parts of polyethylene terephthalate A, 30-50 parts of polypropylene terephthalate, and 5-10 parts of functional masterbatch A; the raw material components of the core layer include: 60-80 parts of polyethylene terephthalate B and 10-20 parts of functional masterbatch B.

3. The flexible copolyester solar cell backsheet film according to claim 1, characterized in that: The functional masterbatch A is prepared by high-speed mixing and melt granulation of polyethylene terephthalate A powder, pigment A and additive A; the functional masterbatch B is prepared by high-speed mixing and melt granulation of polyethylene terephthalate B powder, pigment B and additive B.

4. The flexible copolyester solar cell backsheet film according to claim 3, characterized in that: The pigment A and the pigment B both include titanium dioxide and one or more of zinc oxide, calcium carbonate, barium sulfate, and zirconium oxide.

5. The flexible copolyester solar cell backsheet film according to claim 3, characterized in that: The auxiliary agent A and the auxiliary agent B both include an anti-hydrolysis agent, an antioxidant and a light stabilizer.

6. The flexible copolyester solar cell backsheet film according to claim 5, characterized in that: The anti-hydrolysis agent is selected from one or more of Stabaxol 1, Stabaxol P, Stabaxol P100, Stabaxol P200, and Stabaxol P400.

7. The flexible copolyester solar cell backsheet film according to claim 6, characterized in that: The anti-hydrolysis agent is Stabaxol 1.

8. The flexible copolyester solar cell backsheet film according to claim 5, characterized in that: The antioxidant is selected from one or more of antioxidant 1076, antioxidant B215, antioxidant B900, and antioxidant 264.

9. The flexible copolyester solar cell backsheet film according to claim 5, characterized in that: The light stabilizer is selected from one or more of light stabilizer 770, light stabilizer 292, and light stabilizer 944.

10. A method for preparing a flexible copolyester solar cell backsheet film, for preparing a flexible copolyester solar cell backsheet film according to any one of claims 1 to 9, characterized in that: The method is specifically: The vacuum-dried polyethylene terephthalate A, polypropylene terephthalate and functional masterbatch A are supplied to the A-layer extruder, while the vacuum-dried polyethylene terephthalate B and functional masterbatch B are supplied to the B-layer extruder. They are co-extruded into films, and then stretched longitudinally and transversely and heat-set simultaneously to obtain the backsheet film.

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