High-light-transmittance hot melt adhesive tape and preparation method thereof

Abstract

The invention relates to the technical field of adhesive tapes, in particular to a high-light-transmittance hot melt adhesive tape and a preparation method thereof. The high-light-transmittance hot melt adhesive tape is prepared from the following raw materials in parts by weight: 20 to 60 parts of softening agent, 2 to 10 parts of antioxidant, 90 to 160 parts of hydrogenated tackifying resin, 60 to 120 parts of thermoplastic elastomer, 1 to 5 parts of coupling agent and 40 to 80 parts of polydimethylsiloxane. According to the invention, the high-light-transmittance hot melt adhesive tape is used, the metal welding strip and the auxiliary grid are bonded to realize the bonding function, the process is simple, the production efficiency and the processing precision are greatly improved, the effects of high light transmittance, good flexibility and reliable bonding are achieved, and the product performance is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive tapes, and in particular to a high-transmittance hot-melt adhesive tape and a preparation method thereof. Background Art

[0002] With the continuous promotion and application of 0BB (busbar-free) technology in the photovoltaic industry, the main grid that uses a large amount of silver paste is replaced by a conductive solder strip, and the conductive solder strip is bonded to the secondary grid to gather current, which can reduce the shading area and the transmission distance of the current, thereby improving the efficiency of photovoltaic modules and greatly reducing production costs. At present, the methods for fixing the conductive solder strip to the secondary grid mainly include screen printing and direct welding. The disadvantages of the screen printing method are: 1. The conductive solder strip is fixed to the secondary grid by curing UV glue. This method requires many glue dispensing positions, low efficiency, high precision requirements, and complex process flow; 2. During the curing process of UV glue, since the conductive solder strip will block part of the light, it will affect the curing of the UV glue in the blocked part, resulting in poor bonding; 3. After long-term UV aging, the UV glue will turn yellow, reduce the transmittance, and affect the appearance of the module and energy conversion. The disadvantages of the direct welding method are: 1. It is difficult to provide sufficient bonding strength, and the conductive solder strip is very easy to fall off from the battery cell; 2. The welding flexibility is insufficient, and there is a risk of welding fracture failure during the aging test of hot and cold cycles. Therefore, it is necessary to improve the above problems. Summary of the invention

[0003] In view of the above problems, the present invention provides a high-transmittance hot-melt adhesive tape and a preparation method thereof, which greatly simplifies the construction process and provides reliable bonding performance and high transmittance.

[0004] To achieve the above objectives, the technical solutions adopted are:

[0005] One of the purposes of the present invention is to provide a high-transmittance hot-melt adhesive tape, the raw materials of which include the following substances in parts by weight: 20 to 60 parts of a softener, 2 to 10 parts of an antioxidant, 90 to 160 parts of a hydrogenated tackifying resin, 60 to 120 parts of a thermoplastic elastomer, 1 to 5 parts of a coupling agent, and 40 to 80 parts of polydimethylsiloxane.

[0006] The softener is one or more of naphthenic oil, polybutadiene, and polyisoprene, preferably naphthenic oil KN4010; the antioxidant is one or more of sterically hindered phenol, phosphite, and sulfur-containing synergist, preferably synergistic antioxidant 215; the hydrogenated tackifying resin is one or more of hydrogenated petroleum resin, hydrogenated terpene resin, and hydrogenated rosin resin, preferably hydrogenated petroleum resin; the thermoplastic elastomer is one or more of SIS, SBS, SEBS, and modified products of SIS, SBS, and SEBS, preferably SEBS; the coupling agent is one or more of silane coupling agents KH-550, KH-560, and KH-570, preferably KH-560; the polydimethylsiloxane is Dow Corning DC-184. The coating thickness is 0.005-0.050 mm, preferably 0.030 mm.

[0007] The second object of the present invention is to provide a method for preparing the high-transmittance hot-melt adhesive tape, comprising the following steps:

[0008] (1) Add softener and antioxidant into hot melt stirring kettle and stir thoroughly;

[0009] (2) Raise the temperature to 160-180°C, add hydrogenated tackifying resin and thermoplastic elastomer, and stir until all are melted evenly;

[0010] (3) Cooling to 140-160°C, adding coupling agent and polydimethylsiloxane, vacuuming and stirring until all are melted evenly;

[0011] (4) Coating with a hot melt coater, the coating thickness is 0.005-0.050 mm, and the semi-finished mother roll is obtained after natural cooling;

[0012] (5) The semi-finished mother roll is slit and rolled into a high-transmittance hot-melt adhesive tape according to the required width.

[0013] Preferably, the coating thickness is 0.030 mm.

[0014] Preferably, the above steps (2) and (3) are both carried out under nitrogen protection conditions.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the present invention uses high-transmittance hot-melt adhesive tape to bond the metal welding strip and the auxiliary grid to achieve the bonding function, the process is simple, the production efficiency and processing accuracy are greatly improved, and the effects of high transmittance, good flexibility and reliable bonding are achieved, greatly improving product performance. DETAILED DESCRIPTION

[0016] The present invention is described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0017] Example 1

[0018] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw materials are composed of the following components (the parts mentioned are all parts by weight):

[0019] 20 parts of softener (Xinjiang Karamay Petroleum, KN4010); 2 parts of antioxidant (antioxidant 215); 90 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 60 parts of thermoplastic elastomer (American Kraton, G1660), 1 part of coupling agent (KH-560), 60 parts of polydimethylsiloxane (Dow Corning DC-184).

[0020] The preparation method comprises the following steps:

[0021] (1) Add softener and antioxidant into hot melt stirring kettle and stir thoroughly;

[0022] (2) Raise the temperature to 170°C, add hydrogenated tackifying resin and thermoplastic elastomer, and stir until they are completely dissolved;

[0023] (3) Cooling to 150°C, adding coupling agent and polydimethylsiloxane, vacuuming and stirring until all are dissolved evenly;

[0024] (4) Coating with a hot melt coater, the coating thickness is 0.030 mm, and the semi-finished mother roll is obtained after natural cooling;

[0025] (5) The semi-finished mother roll is slit and rolled into a high-transmittance hot-melt adhesive tape according to the required width.

[0026] Example 2

[0027] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw materials are composed of the following components (the parts mentioned are all parts by weight):

[0028] 30 parts of softener (Xinjiang Karamay Petroleum, KN4010); 4 parts of antioxidant (antioxidant 215); 110 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 75 parts of thermoplastic elastomer (American Kraton, G1660), 3 parts of coupling agent (KH-560), 50 parts of polydimethylsiloxane (Dow Corning DC-184).

[0029] The preparation steps are the same as those in Example 1, and a high light transmittance hot melt adhesive tape with a thickness of 0.030 mm is prepared.

[0030] Example 3

[0031] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw materials are composed of the following components (the parts mentioned are all parts by weight):

[0032] 40 parts of softener (Xinjiang Karamay Petroleum, KN4010); 6 parts of antioxidant (Antioxidant 215); 135 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 90 parts of thermoplastic elastomer (American Kraton, G1660), 4 parts of coupling agent (KH-560), 70 parts of polydimethylsiloxane (Dow Corning DC-184).

[0033] The preparation steps are the same as those in Example 1, and a high light transmittance hot melt adhesive tape with a thickness of 0.030 mm is prepared.

[0034] Example 4

[0035] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw materials are composed of the following components (the parts mentioned are all parts by weight):

[0036] 60 parts of softener (Xinjiang Karamay Petroleum, KN4010); 10 parts of antioxidant (Antioxidant 215); 160 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 120 parts of thermoplastic elastomer (American Kraton, G1660), 5 parts of coupling agent (KH-560), 80 parts of polydimethylsiloxane (Dow Corning DC-184).

[0037] The preparation steps are the same as those in Example 1, and a high light transmittance hot melt adhesive tape with a thickness of 0.030 mm is prepared.

[0038] Example 5

[0039] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw material composition is the same as that of Example 2, except that the high-transmittance hot-melt adhesive tape is made to have a thickness of 0.005 mm.

[0040] Example 6

[0041] A high-transmittance hot-melt adhesive tape and a preparation method thereof, wherein the raw material composition is the same as that of Example 2, except that the high-transmittance hot-melt adhesive tape is made to have a thickness of 0.050 mm.

[0042] Comparative Example 1

[0043] The polydimethylsiloxane is not contained, and the rest is the same as that in Example 1.

[0044] The raw materials are composed of the following components (the parts are all by weight):

[0045] 20 parts of softener (Xinjiang Karamay Petroleum, KN4010); 2 parts of antioxidant (antioxidant 215); 90 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 60 parts of thermoplastic elastomer (American Kraton, G1660), 1 part of coupling agent (KH-560).

[0046] A hot melt adhesive tape with a thickness of 0.030 mm was prepared according to the above preparation method.

[0047] Comparative Example 2

[0048] Contains less polydimethylsiloxane, and the rest is the same as Example 1.

[0049] The raw materials are composed of the following components (the parts are all by weight):

[0050] 20 parts of softener (Xinjiang Karamay Petroleum, KN4010); 2 parts of antioxidant (antioxidant 215); 90 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 60 parts of thermoplastic elastomer (American Kraton, G1660), 1 part of coupling agent (KH-560), 30 parts of polydimethylsiloxane (Dow Corning DC-184).

[0051] A hot melt adhesive tape with a thickness of 0.030 mm was prepared according to the above preparation method.

[0052] Comparative Example 3

[0053] It contains more polydimethylsiloxane, and the rest is the same as Example 4.

[0054] The raw materials are composed of the following components (the parts are all by weight):

[0055] 60 parts of softener (Xinjiang Karamay Petroleum, KN4010); 10 parts of antioxidant (Antioxidant 215); 160 parts of hydrogenated petroleum resin (ExxonMobil, 5600); 120 parts of thermoplastic elastomer (American Kraton, G1660), 1 part of coupling agent (KH-560), 90 parts of polydimethylsiloxane (Dow Corning DC-184).

[0056] A hot melt adhesive tape with a thickness of 0.030 mm was prepared according to the above preparation method.

[0057] Comparative Example 4

[0058] Use UV glue for bonding.

[0059] Comparative Example 5

[0060] Direct welding is used.

[0061] test

[0062] The following tests were performed on the high light transmittance hot melt adhesive tapes obtained in Examples 1 to 6 and Comparative Examples 1 to 5:

[0063] (1) Adhesion performance: A 180° peel strength test was performed using a tensile testing machine in accordance with GB2792-2014.

[0064] (2) Light transmittance: Use a colorimeter (instrument manufacturer: Konica Minolta, model: CM-3700A) to test the light transmittance under normal conditions and after UV 120 kwh.

[0065] The results of the above tests are shown in Table 1.

[0066] Table 1. Test results of hot melt adhesive tapes of Examples 1 to 6 and Comparative Examples 1 to 5

[0067]

[0068] It can be seen from the test results in Table 1 that Examples 3 and 4 have better comprehensive performance and can be used as better embodiments of the present invention. It can be seen from the results shown in Table 1 that the present invention has found that polydimethylsiloxane has the dual effects of light transmission and viscosity enhancement. When polydimethylsiloxane is not contained or contained in small amounts, such as Comparative Examples 1 and 2, its bonding performance and light transmittance are much lower than those of the embodiments; when polydimethylsiloxane is contained in large amounts, such as Comparative Example 3, the bonding performance will decrease. Due to the poor toughness of UV glue, there is a yellowing phenomenon, such as in Comparative Example 4, whose bonding performance and light transmittance are lower than those of the embodiments. When direct welding is used, such as in Comparative Example 5, due to the high and low temperature positions of the solder joints, the deformation caused by the resulting solder joints to fall off, resulting in bonding failure. In summary, it can be explained that the high transmittance hot melt adhesive tape of the present invention meets the requirements.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high light transmittance hot melt adhesive tape, characterized in that: The raw materials include the following substances in parts by weight: 20-60 parts of softener, 2-10 parts of antioxidant, 90-160 parts of hydrogenated tackifying resin, 60-120 parts of thermoplastic elastomer, 1-5 parts of coupling agent and 40-80 parts of polydimethylsiloxane.

2. The high light transmittance hot melt adhesive tape according to claim 1, characterized in that: The softener is one or more of naphthenic oil, polybutadiene and polyisoprene.

3. The high light transmittance hot melt adhesive tape according to claim 1, characterized in that: The antioxidant is one or more of sterically hindered phenol, phosphite, and sulfur-containing synergist.

4. The high light transmittance hot melt adhesive tape according to claim 1, characterized in that: The hydrogenated tackifying resin is one or more of hydrogenated petroleum resin, hydrogenated terpene resin and hydrogenated rosin resin.

5. The high light transmittance hot melt adhesive tape according to claim 1, characterized in that: The thermoplastic elastomer is one or more of SIS, SBS, SEBS and modified products of SIS, SBS and SEBS.

6. The high light transmittance hot melt adhesive tape according to claim 1, characterized in that: The coupling agent is one or more of the silane coupling agents KH-550, KH-560, and KH-570.

7. A method for preparing a high light transmittance hot melt adhesive tape according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Add softener and antioxidant into hot melt stirring kettle and stir thoroughly; (2) Raise the temperature to 160-180°C, add hydrogenated tackifying resin and thermoplastic elastomer, and stir until all are melted evenly; (3) Cooling to 140-160°C, adding coupling agent and polydimethylsiloxane, vacuuming and stirring until all are melted evenly; (4) Coating with a hot melt coater, the coating thickness is 0.005-0.050 mm, and the semi-finished mother roll is obtained after natural cooling; (5) The semi-finished mother roll is slit and rolled into a high-transmittance hot-melt adhesive tape according to the required width.

8. A method for preparing a high-transmittance hot-melt adhesive tape as claimed in claim 7, characterized in that: The coating thickness is 0.030 mm.

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