Preparation method of high temperature positioning tape

Abstract

This invention discloses a method for preparing a high-temperature positioning tape, comprising the following steps: stirring isooctyl acrylate, isobornyl acrylate, hydroxyethyl acrylate, dibutyl phthalate, methyl methacrylate, and ethyl acetate; gradually heating to 60-70°C, adding azobisisobutyronitrile (AIBN), reacting for 1-3 hours, adding AIBN again and raising the reaction temperature to 75-85°C, reacting for 2-4 hours, and after the reaction is complete, adding ethyl acetate to form a synthetic adhesive; adding an aliphatic isocyanate curing agent and a benzotriazole UV absorber to the synthetic adhesive, adjusting the solid content to 28-32% with an organic solvent, transferring it onto a substrate layer, and curing in an oven. This invention's photovoltaic high-temperature positioning tape improves both the weather resistance of the adhesive itself, enhancing its resistance to yellowing after high-temperature and high-humidity aging, and also increases its adhesive strength.

Description

Technical Field

[0001] This invention relates to the technical field of positioning tapes, and more particularly to a method for preparing high-temperature positioning tapes. Background Technology

[0002] Photovoltaic power generation, as one of the cleanest new energy technologies today, is widely used. The general manufacturing process of photovoltaic modules involves first welding photovoltaic panels to form a series structure, assembling solar cells. Then, tempered glass, transparent EVA (ethylene-vinyl acetate copolymer), solar cells, transparent EVA, and a backsheet—these five layers—are hot-pressed together to form a complete photovoltaic module. During the hot-pressing of these multi-layered structures, the temperature is typically around 210℃, while EVA's melting point is around 120℃. Therefore, after hot pressing, the EVA melts and flows, causing the solar cells to shift. Consequently, positioning tape is needed between the EVA and the solar cells to provide fixation. Currently available high-temperature positioning tapes have issues with yellowing properties after high temperatures and shrinkage at high temperatures, which can lead to problems with the photovoltaic panels. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing a high-temperature positioning tape. The high-temperature positioning tape obtained by the preparation method not only improves the weather resistance of the adhesive itself, thus improving its resistance to yellowing after aging in high temperature and high humidity, but also improves the bonding strength.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing a high-temperature positioning tape, comprising the following steps:

[0005] Step 1: Mix and stir 60 parts of isooctyl acrylate, 18-22 parts of isobornyl acrylate, 8-12 parts of hydroxyethyl acrylate, 6-8 parts of dibutyl phthalate, 2.5-3.5 parts of methyl methacrylate, and 100 parts of ethyl acetate.

[0006] Step 2: Gradually raise the temperature to 60~70℃, add 0.05~0.15 parts of azobisisobutyronitrile, react for 1~3 hours, add another 0.15~0.3 parts of azobisisobutyronitrile and raise the reaction temperature to 75~85℃, react for 2~4 hours, and after the reaction is completed, add 40~60 parts of ethyl acetate to form a synthetic adhesive.

[0007] Step 3: Add 0.1 to 0.5 parts of aliphatic isocyanate curing agent and 0.1 to 1 part of benzotriazole UV absorber to 100 parts of the synthetic adhesive obtained in Step 2. Adjust the solid content to 28 to 32% with organic solvent, transfer it to the substrate layer, and cure it in an oven to obtain photovoltaic high-temperature positioning tape.

[0008] The following is a further improvement to the above technical solution:

[0009] 1. In the above scheme, the curing temperature in step three is 55℃.

[0010] 2. In the above scheme, nitrogen gas is introduced and stirred for 20-40 minutes between step one and step two.

[0011] 3. In the above scheme, the substrate layer is a polyester film or a polypropylene film.

[0012] 4. In the above scheme, the organic solvent is one of ethyl acetate, toluene, and butyl acetate.

[0013] 5. In the above scheme, the curing agent is an aliphatic isocyanate curing agent.

[0014] 6. In the above scheme, the ultraviolet absorber is a benzotriazole ultraviolet absorber.

[0015] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0016] The method for preparing the high-temperature positioning tape of the present invention further includes adding 18-22 parts of isobornyl acrylate and 6-8 parts of dibutyl phthalate to the synthetic adhesive layer of the modified acrylate adhesive. This not only improves the weather resistance of the adhesive itself and enhances its resistance to yellowing after aging in high temperature and high humidity, but also improves the bonding strength. Attached Figure Description

[0017] Appendix Figure 1 This is a graph showing the ultraviolet transmittance of an embodiment of the present invention. Detailed Implementation

[0018] The present patent can be further understood through the specific embodiments given below, but they are not intended to limit the present patent.

[0019] The present invention will be further described below with reference to embodiments:

[0020] Examples 1-4: A method for preparing a high-temperature positioning tape, the high-temperature positioning tape comprising: a substrate layer 1 and a modified acrylic adhesive layer 2 located on the surface of the substrate layer 1, the modified acrylic adhesive layer 2 being composed of the following components in parts by weight, as shown in Table 1:

[0021] Table 1

[0022] Components Example 1 Example 2 Example 3 Example 4 Synthetic glue 100 copies 100 copies 100 copies 100 copies Aliphatic isocyanate curing agent 0.3 copies 0.2 copies 0.3 copies 0.35 copies Benzotriazole UV absorbers 0.3 copies 0.5 copies 0.2 copies 0.3 copies organic solvents 40 copies 50 copies 40 copies 45 copies ;

[0024] The synthetic adhesive is further composed of the following components in parts by weight, as shown in Table 2:

[0025] Table 2

[0026] Components Example 1 Example 2 Example 3 Example 4 60 parts of isooctyl acrylate 60 copies 60 copies 60 copies 60 copies 18-22 parts of isoborneol acrylate 20 copies 18 copies 18 copies 20 copies 8-12 parts of hydroxyethyl acrylate 10 copies 11 copies 10 copies 9 copies 6-8 parts of dibutyl phthalate 7 copies 6 copies 7 copies 7 copies 2.5 to 3.5 parts of methyl methacrylate 3 copies 3.2 copies 3 copies 2.5 portions 140-160 parts of ethyl acetate 150 copies 150 copies 150 copies 150 copies 0.2~0.4 parts of azobisisobutyronitrile (AIBN) 0.3 copies 0.32 copies 0.3 copies 0.3 copies ;

[0028] Includes the following steps:

[0029] Step 1: Mix and stir isooctyl acrylate, isobornyl acrylate, hydroxyethyl acrylate, dibutyl phthalate, methyl methacrylate, and ethyl acetate.

[0030] Step 2: Gradually raise the temperature to 65°C, add azobisisobutyronitrile, react for 2 hours, add azobisisobutyronitrile again and raise the reaction temperature to 80°C, react for 3 hours, and after the reaction is completed, add 50 parts of ethyl acetate to form a synthetic adhesive.

[0031] Step 3: Add an aliphatic isocyanate curing agent and a benzotriazole UV absorber to the synthetic adhesive obtained in Step 2, adjust the solid content to 30% with an organic solvent, transfer it onto the substrate layer, and cure it in an oven to obtain a photovoltaic high-temperature positioning tape.

[0032] In Examples 1-4, the substrate layer is a polypropylene film, and the organic solvent is ethyl acetate.

[0033] The curing temperature in step three above is 55℃.

[0034] Between steps one and two above, nitrogen gas is introduced and the mixture is stirred for 30 minutes.

[0035] Comparative Examples 1-2: A method for preparing a high-temperature positioning tape, the high-temperature positioning tape comprising: a substrate layer 1 and a modified acrylic adhesive layer 2 located on the surface of the substrate layer 1, the modified acrylic adhesive layer 2 being composed of the following components in parts by weight, as shown in Table 3:

[0036] Table 3

[0037] Components Comparative Example 1 Comparative Example 2 Comparative Example 3 Synthetic glue 100 copies 100 copies 100 copies Aliphatic isocyanate curing agent 0.3 copies 0.2 copies 0.3 copies Benzotriazole UV absorbers 0.3 copies 0.5 copies 0.3 copies organic solvents 40 copies 50 copies 40 copies ;

[0039] The synthetic adhesive is further composed of the following components in parts by weight, as shown in Table 4:

[0040] Table 4

[0041] Components Comparative Example 1 Comparative Example 2 Comparative Example 3 Isooctyl acrylate 60 copies 60 copies 60 copies Isoborneol acrylate - - 20 copies Hydroxyethyl acrylate 10 copies 11 copies 10 copies Dibutyl phthalate 7 copies - - Methyl methacrylate 3 copies 3.2 copies 3 copies Ethyl acetate 150 copies 150 copies 150 copies Azobisisobutyronitrile 0.3 copies 0.32 copies 0.3 copies ;

[0043] The steps for the comparative example are the same as those for the embodiment.

[0044] In Comparative Examples 1-3, the substrate layer is a polypropylene film, and the organic solvent is ethyl acetate.

[0045] The photovoltaic high-temperature positioning tapes obtained by the preparation methods of Examples 1-4 and Comparative Examples 1-3 above were subjected to performance testing, and the specific methods are as follows:

[0046] 1. Thickness test

[0047] (1) After taking samples from different locations on the tape, let them stand for 3 hours under standard conditions;

[0048] (2) Place the tape between the thickness gauge measuring heads with the adhesive side facing up, gently place the thickness gauge measuring head and record the value after the reading stabilizes, accurate to 0.001 mm;

[0049] (3) Take 20 points for measurement on each tape, record the values, and calculate the average value.

[0050] 2. Peel force test

[0051] (1) After taking samples from different locations on the tape, let them stand for 3 hours under standard conditions;

[0052] (2) Cut the tape into 3 pieces, each measuring 25.4mm*300mm;

[0053] (3) Wipe the steel plate clean with a lint-free cloth dampened with alcohol three times. Do not touch it with your hands after wiping.

[0054] (4) Remove the release film from the tape, use a rubber roller to stick the adhesive surface onto the steel plate, use a 2 kg pressure roller at a speed of 600 mm / min to press it back and forth twice, and let it stand for 20 minutes under standard conditions. No air bubbles are allowed between the adhesive surface and the steel plate.

[0055] (5) After the static period, use a tensile testing machine to clamp the lower end of the steel plate and the free end of the tape respectively, and peel it off at a speed of 300 mm / min at 180°. Record the readings in the software.

[0056] 3. Yellowing resistance test

[0057] (1) After taking samples from different locations on the tape, let them stand for 3 hours under standard conditions;

[0058] (2) Cut the tape into 50 mm*50 mm pieces and test the yellowness index YI1 of the tape with a UV spectrophotometer;

[0059] (3) Place the tape in the QUV ultraviolet aging test chamber, irradiate it with ultraviolet light for 200 kWh, take out the sample, and test the yellowness index YI2 of the tape with an ultraviolet spectrophotometer.

[0060] (4) Calculate △YI = YI2 - YI1

[0061] 4. Ultraviolet transmittance

[0062] (1) After taking samples from different locations on the tape, let them stand for 3 hours under standard conditions;

[0063] (2) Cut the tape into 50 mm*50 mm pieces and use a UV spectrophotometer to test the UV absorbance of the tape (300-380 nm).

[0064] Table 5

[0065] Test Project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Peel force gf / in 1982 1887 1835 2112 1442 1367 1489 Yellowing Index △YL 1.35 1.15 1.21 1.08 2.61 3.25 2.36 UV absorption ratio 87.7 92.6 82.5 86.4 82.5 85.6 83.9 ;

[0067] As shown in Table 5, the peel strengths of the tapes obtained in Examples 1-4 of this invention were 1982 gf / in, 1887 gf / in, 1835 gf / in, and 2112 gf / in, respectively, and the yellowing indices ΔYI were 1.35, 1.15, 1.21, and 1.08, respectively. The peel strengths of Comparative Examples 1-3 were 1442 gf / in, 1367 gf / in, and 1489 gf / in, respectively, and the yellowing indices ΔYI were 2.61, 3.25, and 2.36, respectively. The photovoltaic high-temperature positioning tapes of Examples 1-4 not only improved the weather resistance of the adhesive itself, thus improving its resistance to yellowing after high-temperature and high-humidity aging, but also increased the bonding strength.

[0068] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method of making a high temperature positioning adhesive tape, characterized by: It comprises the following steps: Step one, 60 parts of isooctyl acrylate, 18-22 parts of isobornyl acrylate, 8-12 parts of hydroxyethyl acrylate, 6-8 parts of dibutyl phthalate, 2.5-3.5 parts of methyl methacrylate, 100 parts of ethyl acetate are mixed and stirred; Step two, gradually increase the temperature to 60-70℃, add 0.05-0.15 parts of azobisisobutyronitrile, react for 1-3h, add 0.15-0.3 parts of azobisisobutyronitrile again and increase the reaction temperature to 75-85℃, react for 2-4h, then add 40-60 parts of ethyl acetate to form the synthetic glue water; Step three, 100 parts of the synthetic glue water obtained in step two, 0.1-0.5 parts of aliphatic isocyanate curing agent, 0.1-1 parts of benzotriazole ultraviolet absorber are added, the solid content is adjusted to 28-32% with organic solvent, transfer coating is carried out on the substrate layer, oven curing is carried out, and photovoltaic high-temperature positioning adhesive tape is obtained.

2. The method of making a high temperature positioning adhesive tape according to claim 1, wherein: The curing temperature of step three is 55℃.

3. The method of claim 1, wherein: Nitrogen is also introduced and stirred for 20-40 minutes between step one and step two.

4. The method of claim 1, wherein: The substrate layer is a polyester film or a polypropylene film.

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