High-shrinkage-resistance EVA photovoltaic adhesive film and preparation method thereof

Abstract

The invention discloses an EVA photovoltaic adhesive film with high shrinkage resistance. The EVA photovoltaic adhesive film is prepared from the following raw materials in parts by weight: 90-95 parts of EVA particles, 5-10 parts of an anti-shrinkage agent, 1-3 parts of a crosslinking composition and 1.5-4 parts of an auxiliary agent. According to the invention, the poly (trimethylene terephthalate) fibers are introduced as the anti-shrinking agent, so that the prepared photovoltaic adhesive film is low in shrinkage rate, is applied to the photovoltaic field, and is good in aging resistance. The combination of the poly (1, 3-propylene glycol terephthalate) fibers and the palm fibers is adopted as the anti-shrinking agent, so that the shrinkage rate of the EVA adhesive film is further reduced, the tensile strength and the elongation at break are also maintained to be better, and the use performance requirements of the EVA photovoltaic adhesive film can be met.

Description

Technical Field

[0001] The invention relates to the field of preparation of plastics and composite materials thereof, and in particular to a high-shrinkage-resistant EVA photovoltaic adhesive film and a preparation method thereof. Background Art

[0002] EVA film is an important material in the field of solar cell encapsulation and an important component of photovoltaic modules. EVA film has the advantages of high light transmittance, high bonding strength and good flexibility, and is widely used in the field of photovoltaic modules. However, EVA film also has problems such as poor adhesion, poor aging resistance and poor material compatibility, which limits the application of EVA film. Traditional EVA film has the problem of dimensional shrinkage after curing, and its size is unstable, which has disadvantages in practical application. Therefore, it is very important to develop an EVA photovoltaic film with high shrinkage resistance.

[0003] Chinese invention patent CN104893108A discloses a low-shrinkage, high-impact, halogen-free, flame-retardant PP / PS alloy composite material and its preparation method. The use of chopped fibers as an anti-shrinkage agent will affect the toughness of the alloy composite material, and a toughening agent needs to be added to improve its mechanical effect. Chinese invention patent CN107459688A discloses an EVA rubber synthetic foam material. By introducing polyacrylonitrile fibers, it has a soft texture, better anti-shrinkage performance, and improved fatigue resistance, but it cannot be used in photovoltaic materials and has poor sealing effect. Summary of the invention

[0004] In order to develop a highly shrinkage-resistant EVA photovoltaic film, the first aspect of the present invention provides a highly shrinkage-resistant EVA photovoltaic film, the preparation raw materials comprising, by weight: 90-95 parts of EVA particles, 5-10 parts of anti-shrinkage agent, 1-3 parts of cross-linking composition, and 1.5-4 parts of auxiliary agent.

[0005] As a preferred embodiment, the density of the EVA particles is 0.5-1g / cm 3 , vinyl acetate content is 25-30wt%, and the melt flow rate at 190°C and 2.16kg is 5-8g / 10min.

[0006] As a preferred embodiment, the density of the EVA particles is 0.948 g / cm 3 , vinyl acetate content is 28wt%, and the melt flow rate at 190℃ and 2.16kg is 6g / 10min.

[0007] As a preferred embodiment, the anti-shrinkage agent is a fiber compound, and the fiber compound includes artificial fibers and natural fibers.

[0008] As a preferred embodiment, the man-made fiber is selected from at least one of polyester fiber, polyacrylonitrile fiber, polyamide fiber, polypropylene fiber, and polyvinyl formal fiber; the natural fiber is selected from at least one of hemp fiber, palm fiber, asbestos fiber, and metal fiber.

[0009] As a preferred embodiment, the anti-shrinkage agent includes polyester fiber, hemp fiber, and palm fiber.

[0010] As a preferred embodiment, the polyester fiber is poly(1,3-trimethylene terephthalate) fiber, and its parameters are: POY: 50-150D / 36-72F. The hemp fiber is jute fiber. The jute fiber is nano-silicon dioxide grafted jute fiber. The length of the palm fiber is 10-25 mm.

[0011] The inventor used poly(1,3-trimethylene terephthalate) fiber as an anti-shrinkage agent during the experiment, and the parameters of poly(1,3-trimethylene terephthalate) fiber were POY: 50-150D / 36-72F. The prepared photovoltaic adhesive film had a low shrinkage rate and good aging resistance when applied to the photovoltaic field. The possible reason is that the poly(1,3-trimethylene terephthalate) fiber, which is a composite of poly(1,3-trimethylene terephthalate) and propylene glycol, has certain support and elasticity in the EVA particles, and can achieve good anti-shrinkage in the structure of ethylene and vinyl acetate. And the poly(1,3-trimethylene terephthalate) fiber with preferred coarseness and structure is used as an anti-shrinkage agent, and the formed photovoltaic adhesive film has a certain degree of orientation, good stability, and is not easy to shrink after curing.

[0012] As a preferred embodiment, the anti-shrinkage agent comprises a combination of poly(1,3-trimethylene terephthalate) fiber and palm fiber, and further preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the palm fiber is 1:(1-3). Preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the palm fiber is 1:(1-2). Preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the palm fiber is 1:1.

[0013] As a preferred embodiment, the anti-shrinkage agent comprises a combination of poly(1,3-trimethylene terephthalate) fiber and jute fiber, and further preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the jute fiber is 1:(1-3). Preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the jute fiber is 1:(1-2). Preferably, the weight ratio of the poly(1,3-trimethylene terephthalate) fiber to the jute fiber is 1:1.

[0014] The inventors found during the experiment that when the weight ratio of EVA to poly(1,3-trimethylene terephthalate) fiber is (90-95):(5-10), the prepared photovoltaic film can maintain a small shrinkage rate while maintaining excellent tensile properties. It is speculated that the possible reason is that the ethylene and vinyl acetate structures of EVA intersperse with terephthalic acid and propylene glycol, resulting in cross-linking, which can reduce the shrinkage of the ethylene and vinyl acetate structures. At the same time, the presence of propylene glycol, ethylene structure, and vinyl acetate maintains the toughness of the photovoltaic film. In addition, at the preferred weight ratio, EVA and poly(1,3-trimethylene terephthalate) fiber have good compatibility. Exceeding the preferred weight ratio, unreacted small molecules are easily generated, affecting the overall compatibility uniformity of the system, and further affecting the toughness and strength of the photovoltaic film.

[0015] As a preferred embodiment, the auxiliary agent includes at least one of an antioxidant, a silane coupling agent, an anti-hydrolysis agent, an ultraviolet absorber, and a light stabilizer.

[0016] As a preferred embodiment, the antioxidant is selected from at least one of a phenolic antioxidant or a phosphate antioxidant.

[0017] As a preferred embodiment, the antioxidant is selected from at least one of antioxidant 1010 or antioxidant 168.

[0018] As a preferred embodiment, the silane coupling agent includes but is not limited to KH-550, KH-570, and KH-560.

[0019] As a preferred embodiment, the auxiliary agent includes, by weight, 0.5-1 part of antioxidant, 0.7-1 part of silane coupling agent, 0.5-0.7 part of anti-hydrolysis agent, and 0.5-1 part of ultraviolet absorber.

[0020] As a preferred embodiment, the cross-linking composition comprises a cross-linking agent and a co-cross-linking agent, and the weight ratio of the cross-linking agent to the co-cross-linking agent is (1-1.5): (0.8-1). Further preferably, the weight ratio of the cross-linking agent to the co-cross-linking agent is (1.4-1.8): (0.7-0.8). Preferably, the weight ratio of the cross-linking agent to the co-cross-linking agent is 1.5:0.8

[0021] As a preferred embodiment, the crosslinking agent is dicumyl peroxide, and the auxiliary crosslinking agent is trimethylolpropane trimethacrylate.

[0022] As a preferred embodiment, the ultraviolet absorber includes but is not limited to UV-3346 and UV-770.

[0023] The second aspect of the present invention provides a method for preparing a high shrinkage-resistant EVA photovoltaic adhesive film, comprising the following steps:

[0024] S1: adding the prepared raw materials into a mixer and stirring them evenly to obtain a blend;

[0025] S2 adds the blended material into a twin-screw extruder, shears, blends and extrude, cools and pelletizes, and obtains a high shrinkage-resistant EVA photovoltaic film material;

[0026] S3 casts the high shrinkage-resistant EVA photovoltaic adhesive film material into a film, and performs lamination treatment to obtain the high shrinkage-resistant EVA photovoltaic adhesive film.

[0027] As a preferred embodiment, the shearing speed of the twin-screw extruder is 100-300 rpm.

[0028] As a preferred embodiment, the melt extrusion temperature of the twin-screw extruder is 65-85°C.

[0029] As a preferred embodiment, the melt extrusion temperature range of the twin-screw extruder is 65°C, 67°C, 70°C, 75°C, 80°C, 75°C, and 75°C.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The highly shrinkage-resistant EVA photovoltaic film of the present invention introduces poly(1,3-trimethylene terephthalate) fiber as an anti-shrinkage agent. The prepared photovoltaic film has a low shrinkage rate and is applied in the photovoltaic field with good aging resistance.

[0032] (2) The high shrinkage-resistant EVA photovoltaic film of the present invention has a weight ratio of EVA to poly(1,3-trimethylene terephthalate) fiber of (90-95):(5-10). The prepared photovoltaic film can maintain excellent tensile properties while maintaining a relatively small shrinkage rate.

[0033] (3) The highly shrinkage-resistant EVA photovoltaic film of the present invention adopts a combination of poly(1,3-trimethylene terephthalate) fiber and palm fiber as an anti-shrinkage agent, which further reduces the shrinkage rate of the EVA film, and also maintains a better tensile strength and elongation at break.

[0034] (4) The high shrinkage resistance EVA photovoltaic adhesive film of the present invention uses a combination of diisopropylbenzene peroxide and trimethylolpropane trimethacrylate as a cross-linking composition, which can improve the compatibility of the system and avoid mechanical problems caused by poor compatibility.

[0035] (5) The highly shrinkage-resistant EVA photovoltaic film of the present invention has high shrinkage resistance, can meet the performance requirements of the EVA photovoltaic film, and has good aging resistance and UV resistance. DETAILED DESCRIPTION

[0036] Example 1

[0037] A highly shrinkage-resistant EVA photovoltaic adhesive film, wherein the raw materials for its preparation include, by weight: 93 parts of EVA particles, 10 parts of an anti-shrinkage agent, 2.2 parts of a cross-linking composition, 0.7 parts of an antioxidant, 0.8 parts of a silane coupling agent, 0.7 parts of an anti-hydrolysis agent, and 0.7 parts of an ultraviolet absorber.

[0038] The density of the EVA particles is 0.948 g / cm 3 , vinyl acetate content is 28wt%, the melt flow rate at 190°C and 2.16kg is 6g / 10min, purchased from Formosa Plastics Corporation, brand EVA 7670S.

[0039] The cross-linking composition includes dicumyl peroxide and trimethylolpropane trimethacrylate in a weight ratio of 1.4:0.8.

[0040] The antioxidant is antioxidant 1010; the silane coupling agent is KH-550.

[0041] The anti-hydrolysis agent is purchased from BASF, with the brand name AW-200; the ultraviolet absorber is UV-3346.

[0042] The anti-shrinkage agent is poly(1,3-trimethylene terephthalate) fiber, and its parameters are: POY: 50-150D / 36-72F, purchased from Jiangsu Dongfang Shenghong Co., Ltd., brand H400.

[0043] A method for preparing a highly shrinkage-resistant EVA photovoltaic adhesive film comprises the following steps:

[0044] S1: adding the prepared raw materials into a mixer and stirring them evenly to obtain a blend;

[0045] S2 adds the blended material into a twin-screw extruder, shears, blends and extrude, cools and pelletizes, and obtains a high shrinkage-resistant EVA photovoltaic film material;

[0046] S3 casts the high shrinkage-resistant EVA photovoltaic adhesive film material into a film, and performs lamination treatment to obtain the high shrinkage-resistant EVA photovoltaic adhesive film.

[0047] The shear speed of the twin-screw extruder is 200 rpm. The melt extrusion temperature range of the twin-screw extruder is 65°C, 67°C, 70°C, 75°C, 80°C, 75°C, and 75°C.

[0048] The lamination temperature is 90° C., and the thickness of the prepared high shrinkage-resistant EVA photovoltaic adhesive film is 0.2 mm.

[0049] Example 2

[0050] A highly shrinkage-resistant EVA photovoltaic adhesive film, wherein the raw materials for its preparation include, by weight: 95 parts of EVA particles, 10 parts of an anti-shrinkage agent, 2.3 parts of a cross-linking composition, 0.8 parts of an antioxidant, 0.8 parts of a silane coupling agent, 0.8 parts of an anti-hydrolysis agent, and 0.7 parts of an ultraviolet absorber.

[0051] The density of the EVA particles is 0.948 g / cm 3 , vinyl acetate content is 28wt%, the melt flow rate is 6g / 10min at 190℃ and 2.16kg, purchased from Formosa Plastics Corporation, brand EVA7670S.

[0052] The cross-linking composition comprises dicumyl peroxide and trimethylolpropane trimethacrylate in a weight ratio of 1.5:0.8.

[0053] The antioxidant is antioxidant 1010; the silane coupling agent is KH-550.

[0054] The anti-hydrolysis agent is purchased from BASF, with the brand name AW-200; the ultraviolet absorber is UV-3346.

[0055] The anti-shrinkage agent is a combination of poly(1,3-trimethylene terephthalate) fiber and jute fiber, with a weight ratio of 1:1. The parameters of poly(1,3-trimethylene terephthalate) fiber are: POY: 50-150D / 36-72F, purchased from Jiangsu Dongfang Shenghong Co., Ltd., brand H400. The jute fiber is nano-silicon dioxide grafted jute fiber, purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0056] A method for preparing a highly shrinkage-resistant EVA photovoltaic adhesive film comprises the following steps:

[0057] S1: adding the prepared raw materials into a mixer and stirring them evenly to obtain a blend;

[0058] S2 adds the blended material into a twin-screw extruder, shears, blends and extrude, cools and pelletizes, and obtains a high shrinkage-resistant EVA photovoltaic film material;

[0059] S3 casts the high shrinkage-resistant EVA photovoltaic adhesive film material into a film, and performs lamination treatment to obtain the high shrinkage-resistant EVA photovoltaic adhesive film.

[0060] The shear speed of the twin-screw extruder is 200 rpm. The melt extrusion temperature range of the twin-screw extruder is 65°C, 67°C, 70°C, 75°C, 80°C, 75°C, and 75°C.

[0061] The lamination temperature is 90° C., and the thickness of the prepared high shrinkage-resistant EVA photovoltaic adhesive film is 0.2 mm.

[0062] Example 3

[0063] A highly shrinkage-resistant EVA photovoltaic adhesive film, wherein the raw materials for its preparation include, by weight, 90 parts of EVA particles, 10 parts of an anti-shrinkage agent, 2.1 parts of a cross-linking composition, 0.7 parts of an antioxidant, 0.9 parts of a silane coupling agent, 0.7 parts of an anti-hydrolysis agent, and 0.8 parts of an ultraviolet absorber.

[0064] The density of the EVA particles is 0.948 g / cm 3 , vinyl acetate content is 28wt%, the melt flow rate is 6g / 10min at 190℃ and 2.16kg, purchased from Formosa Plastics Corporation, brand EVA7670S.

[0065] The cross-linking composition includes dicumyl peroxide and trimethylolpropane trimethacrylate in a weight ratio of 1.4:0.7.

[0066] The antioxidant is antioxidant 1010; the silane coupling agent is KH-550.

[0067] The anti-hydrolysis agent is purchased from BASF, with the brand name AW-200; the ultraviolet absorber is UV-3346.

[0068] The anti-shrinkage agent is a combination of poly(1,3-trimethylene terephthalate) fiber and palm fiber, with a weight ratio of 1:1. The parameters of poly(1,3-trimethylene terephthalate) fiber are: POY: 50-150D / 36-72F, purchased from Jiangsu Dongfang Shenghong Co., Ltd., brand H400. The length of the palm fiber is 10-25 mm, purchased from Tianjin Weijia Chemical Products Co., Ltd.

[0069] A method for preparing a highly shrinkage-resistant EVA photovoltaic adhesive film comprises the following steps:

[0070] S1: adding the prepared raw materials into a mixer and stirring them evenly to obtain a blend;

[0071] S2 adds the blended material into a twin-screw extruder, shears, blends and extrude, cools and pelletizes, and obtains a high shrinkage-resistant EVA photovoltaic film material;

[0072] S3 casts the high shrinkage-resistant EVA photovoltaic adhesive film material into a film, and performs lamination treatment to obtain the high shrinkage-resistant EVA photovoltaic adhesive film.

[0073] The shear speed of the twin-screw extruder is 200 rpm. The melt extrusion temperature range of the twin-screw extruder is 65°C, 67°C, 70°C, 75°C, 80°C, 75°C, and 75°C.

[0074] The lamination temperature is 90° C., and the thickness of the prepared high shrinkage-resistant EVA photovoltaic adhesive film is 0.2 mm.

[0075] Comparative Example 1

[0076] A highly shrinkage-resistant EVA photovoltaic adhesive film and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the added amount of the anti-shrinkage agent is 0 parts by weight.

[0077] Comparative Example 2

[0078] A highly shrinkage-resistant EVA photovoltaic adhesive film and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the added amount of the anti-shrinkage agent is 5 parts by weight.

[0079] Performance Testing

[0080] 1. Shrinkage rate: refer to GB / T29848-2018 standard test examples and comparative examples to prepare the shrinkage rate of photovoltaic adhesive films.

[0081] 2. Tensile strength: Refer to the tensile strength of the photovoltaic adhesive film prepared in the test examples and comparative examples in GB / T 1040.1-2006 standard, take two 200mm×200mm uncured adhesive films and overlap them, and fully cure the adhesive films according to the lamination treatment regulations in the standard (crosslinking degree above 75%, flat upper and lower surfaces, uniform thickness), and then prepare dumbbell-shaped specimens according to the 5-type specimen standard, at least 5 in each group. The dumbbell-shaped specimens are mounted on a universal material testing machine, fixed with a pneumatic clamp, and tensile tested at a speed of 100mm / min±10mm / min, and the maximum stress is recorded as the tensile strength, and the average test value of the specimen is calculated and recorded in Table 1.

[0082] 3. Elongation at break: Refer to the elongation at break of the photovoltaic adhesive film prepared in the test examples and comparative examples in GB / T 1040.1-2006 standard, take two 200mm×200mm uncured adhesive films and overlap them, and fully cure the adhesive films according to the lamination treatment regulations in the standard (crosslinking degree above 75%, flat upper and lower surfaces, uniform thickness), and then prepare dumbbell-shaped specimens according to the 5-type specimen standard. The dumbbell-shaped specimens are mounted on a universal material testing machine, fixed with a pneumatic clamp, and subjected to a tensile test at a speed of 100mm / min±10mm / min until they break, and the elongation at break is calculated according to the formula in the standard.

[0083] The test results are shown in Table 1.

[0084] Table 1

[0085]

Claims

1. A highly shrinkage-resistant EVA photovoltaic film, characterized in that: The raw materials for preparation include, by weight: 90-95 parts of EVA particles, 5-10 parts of anti-shrinkage agent, 1-3 parts of cross-linking composition, and 1.5-4 parts of auxiliary agent.

2. The high shrinkage resistant EVA photovoltaic adhesive film according to claim 1, characterized in that: The density of the EVA particles is 0.5-1 g / cm 3 , vinyl acetate content is 25-30wt%, and the melt flow rate at 190°C and 2.16kg is 5-8g / 10min.

3. The high shrinkage-resistant EVA photovoltaic adhesive film according to claim 1, characterized in that: The anti-shrinkage agent is a fiber compound, and the fiber compound includes artificial fiber and natural fiber.

4. The high shrinkage-resistant EVA photovoltaic adhesive film according to claim 3, characterized in that: The man-made fiber is selected from at least one of polyester fiber, polyacrylonitrile fiber, polyamide fiber, polypropylene fiber, and polyvinyl formal fiber; the natural fiber is selected from at least one of hemp fiber, palm fiber, asbestos fiber, and metal fiber.

5. The high shrinkage-resistant EVA photovoltaic film according to claim 4, characterized in that: The polyester fiber is poly(1,3-trimethylene terephthalate) fiber, and the hemp fiber is jute fiber.

6. The high shrinkage-resistant EVA photovoltaic adhesive film according to claim 1, characterized in that: The auxiliary agent includes at least one of an antioxidant, a silane coupling agent, an anti-hydrolysis agent, an ultraviolet absorber, and a light stabilizer.

7. The high shrinkage-resistant EVA photovoltaic adhesive film according to claim 1, characterized in that: The cross-linking composition comprises a cross-linking agent and an auxiliary cross-linking agent, and the weight ratio of the cross-linking agent to the auxiliary cross-linking agent is (1-1.5): (0.8-1).

8. A method for preparing the highly shrinkage-resistant EVA photovoltaic adhesive film according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: adding the prepared raw materials into a mixer and stirring them evenly to obtain a blend; S2 adds the blended material into a twin-screw extruder, shears, blends and extrude, cools and pelletizes, and obtains a high shrinkage-resistant EVA photovoltaic film material; S3 casts the high shrinkage-resistant EVA photovoltaic adhesive film material into a film, and performs lamination treatment to obtain the high shrinkage-resistant EVA photovoltaic adhesive film.

9. The method for preparing the highly shrinkage-resistant EVA photovoltaic adhesive film according to claim 8, characterized in that: The shearing speed of the twin-screw extruder is 100-300 rpm.

10. The method for preparing the highly shrinkage-resistant EVA photovoltaic adhesive film according to claim 8, characterized in that: The melt extrusion temperature of the twin-screw extruder is 65-85°C.

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