High-temperature-resistant double-sided tape and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant double-sided tape and a preparation method thereof.The high-temperature-resistant double-sided tape comprises a double-sided tape body, the double-sided tape body comprises a cotton paper base material layer, and high-temperature-resistant acrylate pressure-sensitive adhesive layers are arranged on the two sides of the cotton paper base material layer; wherein double-silicon glassine release paper is arranged on the outer side of one high-temperature-resistant acrylate pressure-sensitive adhesive layer, and a single-silicon release film is arranged on the outer side of the other high-temperature-resistant acrylate pressure-sensitive adhesive layer. According to the invention, the pressure-sensitive adhesive has proper molecular weight and molecular weight distribution through the proportioning combination of the soft and hard monomers and the functional monomers in the formula and a polymerization mode of gradually dropwise adding and feeding, and the adhesive tape is endowed with good holding power and 180-degree peel strength; by introducing the high-temperature-resistant modified monomer and reasonably matching the curing agent, the rigidity and the stability of a PSA molecular chain are improved through the structural characteristics of the heat-resistant monomer, so that the pressure-sensitive adhesive has relatively high bonding strength and heat resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure-sensitive tapes, and particularly to a high-temperature resistant double-sided tape and a preparation method thereof. Background Art

[0002] The full name of the pressure-sensitive adhesive is pressure-sensitive adhesive, which means that a relatively small contact pressure can be used to bond the adhesive to the smooth surface of the adherend, and when the pressure-sensitive adhesive layer is torn off from the bonding surface of the adherend, the adhesive does not contaminate the surface of the adherend.

[0003] In the industry, pressure-sensitive adhesives are generally classified into rubber-based, acrylate-based, and silicone-based according to their materials. Among them, acrylate-based pressure-sensitive adhesives have a wide range of raw material sources, simple preparation processes, fast room-temperature curing, are suitable for bonding most metal and non-metal materials, and have the advantages of excellent light aging resistance, corrosion resistance, excellent antioxidant performance, wide use, and convenient use. They have been widely used in many scientific and industrial fields. However, general solvent-based acrylate pressure-sensitive adhesives have a linear molecular structure and insufficient crosslinking degree, usually having disadvantages such as poor high-temperature resistance, insufficient mechanical properties, and softening at high temperatures. Therefore, their application scope is greatly limited. With the continuous development of industrialization, the adhesive layer formed by traditional pressure-sensitive adhesives cannot meet the high-temperature requirements of the market. After high temperature, the adhesive layer will become soft, resulting in easy peeling. In addition, after the adhesive layer at high temperature returns to room temperature and after aging, there will also be a situation where the adhesive layer cannot be effectively peeled off from the bonding substrate, which will cause the problem of residual glue left on the surface of the bonding substrate after the adhesive layer is peeled off. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-temperature resistant double-sided tape and a preparation method thereof to solve the problems in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A high-temperature resistant double-sided tape, including a double-sided tape body, the double-sided tape body includes a cotton paper substrate layer, high-temperature resistant acrylate pressure-sensitive adhesive layers are provided on both sides of the cotton paper substrate layer, a double-silicone glassine release paper is provided on the outside of one of the high-temperature resistant acrylate pressure-sensitive adhesive layers, and a single-silicone release film is provided on the outside of the other high-temperature resistant acrylate pressure-sensitive adhesive layer.

[0006] Preferably, the preparation of the high-temperature resistant acrylate pressure-sensitive adhesive layer includes the following steps:

[0007] S1. Provide a high-temperature resistant acrylate base pressure-sensitive adhesive, including the following raw materials in parts by weight: 3 - 10 parts of hard monomer, 60 - 95 parts of soft monomer, 3 - 8 parts of functional monomer, 0.2 - 0.6 parts of initiator, 3 - 15 parts of high-temperature resistant modified monomer, and 30 - 80 parts of organic solvent;

[0008] S2. Prepare a high-temperature resistant acrylate pressure-sensitive adhesive from a high-temperature resistant acrylate base pressure-sensitive adhesive, including the following raw materials in parts by weight: 100 parts of the high-temperature resistant acrylate base pressure-sensitive adhesive, 0.2 - 1.5 parts of a curing agent, 0.1 - 0.3 parts of an antioxidant, and 20 - 45 parts of a diluent.

[0009] Preferably, the hard monomer is one or more of methyl acrylate, vinyl acetate, styrene, acrylamide, acrylonitrile, and methyl methacrylate;

[0010] The soft monomer is one or more of butyl acrylate, isooctyl acrylate, and ethyl acrylate;

[0011] The functional monomer is one or more of acrylic acid, 2-hydroxyethyl acrylate, N-methylolacrylamide, 2-hydroxyethyl methacrylate, itaconic acid, and maleic anhydride;

[0012] The initiator is one of azobisisobutyronitrile and benzoyl peroxide;

[0013] The high-temperature resistant modified monomer is one of maleimide, N-vinylpyrrolidone, and N-vinylcarbazole;

[0014] The organic solvent is one of cyclohexane, toluene, acetone, and ethyl acetate.

[0015] Preferably, the preparation of the high-temperature resistant acrylate base pressure-sensitive adhesive includes the following steps:

[0016] S11. Preparation of raw materials: 60 - 70 parts of isooctyl acrylate; 15 - 25 parts of butyl acrylate; 3 - 8 parts of vinyl acetate; 1 - 5 parts of acrylic acid; 1 - 5 parts of 2-hydroxyethyl acrylate; 0.1 - 0.6 parts of azobisisobutyronitrile; 1 - 10 parts of maleimide; 30 - 80 parts of ethyl acetate;

[0017] S12. Dissolution of the initiator: Add 1 / 3 of the total amount of the organic solvent and all of the initiator to a stirring reaction kettle, continuously stir for 0.5 h until the initiator is completely dissolved, and then fill the initiator solution into a preparation container;

[0018] S13. Mixing of monomers: Add the remaining 2 / 3 of the total amount of the organic solvent and all of the formulated monomers to a reaction kettle equipped with a stirrer, a thermometer, and a reflux condenser; continuously stir for 0.5 h to mix evenly, then discharge 60% of the monomer mixture into a preparation container; keep 40% of the mixture in the reaction kettle as the bottom material for the polymerization reaction;

[0019] S14. Polymerization reaction: Raise the temperature of the reaction kettle to 78 - 80 °C, add 15% - 20% of the initiator solution to initiate the polymerization reaction; observe the reaction system. When the system starts to react, that is, when reflux appears in the condenser, slowly drop the remaining initiator solution into the reaction kettle within 3 - 4 hours while maintaining the reaction temperature at 78 - 80 °C. The remaining 60% monomer mixture is uniformly dropped within the same time; after the dropping is completed, continue to keep the temperature for reaction for 1 - 2 hours to fully react the monomers; after the reaction is completed, cool it below 30 °C and filter to collect the material to obtain the high-temperature resistant acrylate-based pressure-sensitive adhesive.

[0020] Preferably, the antioxidant is one or more of hindered phenol antioxidants and phosphate antioxidants; the curing agent is one of the epoxy curing agent GA240 and the isocyanate curing agent L75, and the diluent is ethyl acetate.

[0021] Preferably, the preparation of the high-temperature resistant acrylate pressure-sensitive adhesive includes the following steps:

[0022] S21. Place the high-temperature resistant acrylate-based pressure-sensitive adhesive in a stirring kettle, and at a stirring speed of 300 - 700 revolutions per minute, sequentially add the curing agent and the antioxidant and stir for 30 - 60 min until the additives are completely dispersed and homogenized in the base pressure-sensitive adhesive solution;

[0023] S22. Let it stand and filter the mixed adhesive solution to obtain the high-temperature resistant acrylate pressure-sensitive adhesive.

[0024] A preparation method of a high-temperature resistant double-sided tape includes the following steps:

[0025] Step 1. Uniformly coat the high-temperature resistant acrylate pressure-sensitive adhesive on the high-temperature resistant Grax release paper through a coating process. Send the coated wet adhesive film into a continuous drying oven to fully volatilize the solvent and then laminate it onto the high-temperature resistant cotton paper substrate, and wind up the semi-finished product;

[0026] Step 2. Uniformly coat the high-temperature resistant acrylate pressure-sensitive adhesive on the release film through a coating process. After drying the coated wet adhesive film in the oven under the above conditions, laminate it on the other side of the cotton paper substrate of the semi-finished tape and wind up to obtain the high-temperature resistant double-sided tape;

[0027] Step 3. Put the wound tape into an environment at 40 °C and cure it for more than 48H to completely cure the pressure-sensitive adhesive to obtain the finished high-temperature resistant double-sided tape.

[0028] Preferably, in Step 1 and Step 2, the dry adhesive coating thickness is 25 - 45 μm, the drying temperature is 50 - 120 °C, and the drying time is 5 minutes.

[0029] Preferably, the high-temperature resistant cotton paper substrate uses 14g cotton paper, and the thickness of the high-temperature resistant cotton paper substrate is 20 - 25 μm.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. Good adhesion performance: The ratio combination of soft and hard monomers and functional monomers in the formula and the polymerization method of stepwise dropping feeding make the pressure-sensitive adhesive have a suitable molecular weight and molecular weight distribution, endowing the tape with good holding adhesion and 180° peel strength.

[0032] 2. Improved heat resistance: The introduction of high-temperature resistant modified monomers and the reasonable combination of curing agents increase the rigidity and stability of the PSA molecular chain through the structural characteristics of heat-resistant monomers, so that the pressure-sensitive adhesive has high adhesion strength and heat resistance.

[0033] 3. Antioxidant performance: The addition of antioxidants improves the antioxidant performance of the tape and extends its service life, especially suitable for application scenarios exposed to the environment for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0035] Figure 1 is a schematic structural diagram of the present invention.

[0036] In the figure: 1. Double-silicone glassine release paper; 2. High-temperature resistant acrylate pressure-sensitive adhesive layer; 3. Cotton paper substrate layer; 4. Single-silicone release film. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0038] Please refer to Figure 1 , in an embodiment of the present invention, a high-temperature resistant double-sided tape includes a double-sided tape body. The double-sided tape body includes a cotton paper substrate layer 3. High-temperature resistant acrylate pressure-sensitive adhesive layers 2 are provided on both sides of the cotton paper substrate layer 3. A double-silicone glassine release paper 1 is provided on the outer side of one of the high-temperature resistant acrylate pressure-sensitive adhesive layers 2, and a single-silicone release film 4 is provided on the outer side of the other high-temperature resistant acrylate pressure-sensitive adhesive layer 2.

[0039] The preparation of the high-temperature resistant acrylate pressure-sensitive adhesive layer 2 comprises the following steps:

[0040] S1. Provide a high-temperature resistant acrylate base pressure-sensitive adhesive, comprising the following raw materials in parts by weight: 3-10 parts of a hard monomer, 60-95 parts of a soft monomer, 3-8 parts of a functional monomer, 0.2-0.6 part of an initiator, 3-15 parts of a high-temperature resistant modified monomer, and 30-80 parts of an organic solvent;

[0041] S2. Prepare a high-temperature resistant acrylate pressure-sensitive adhesive from the high-temperature resistant acrylate base pressure-sensitive adhesive, comprising the following raw materials in parts by weight: 100 parts of the temperature-resistant acrylate base pressure-sensitive adhesive, 0.2-1.5 parts of a curing agent, 0.1-0.3 part of an antioxidant, and 20-45 parts of a diluent.

[0042] The hard monomer is one or more of methyl acrylate, vinyl acetate, styrene, acrylamide, acrylonitrile, and methyl methacrylate;

[0043] The soft monomer is one or more of butyl acrylate, isooctyl acrylate, and ethyl acrylate;

[0044] The functional monomer is one or more of acrylic acid, 2-hydroxyethyl acrylate, N-hydroxymethylacrylamide, 2-hydroxyethyl methacrylate, itaconic acid, and maleic anhydride;

[0045] The initiator is one of azobisisobutyronitrile and benzoyl peroxide;

[0046] The high-temperature resistant modified monomer is one of maleimide, N-vinylpyrrolidone, and N-vinylcarbazole;

[0047] The organic solvent is one of cyclohexane, toluene, acetone, and ethyl acetate.

[0048] The preparation of the high-temperature resistant acrylate base pressure-sensitive adhesive comprises the following steps:

[0049] S11. Preparation of raw materials: 60-70 parts of isooctyl acrylate; 15-25 parts of butyl acrylate; 3-8 parts of vinyl acetate; 1-5 parts of acrylic acid; 1-5 parts of 2-hydroxyethyl acrylate; 0.1-0.6 part of azobisisobutyronitrile; 1-10 parts of maleimide; 30-80 parts of ethyl acetate;

[0050] S12. Dissolution of the initiator: Add 1 / 3 of the total amount of the organic solvent and all of the initiator to a stirring reaction kettle, continuously stir for 0.5 h until the initiator is completely dissolved, and then fill the initiator solution into a preparation container;

[0051] S13. Monomer mixing: Add 2 / 3 of the remaining total amount of organic solvents and all the formulated monomers into a reaction kettle equipped with a stirrer, a thermometer, and a reflux condenser; continuously stir for 0.5 h until evenly mixed, then discharge 60% of the monomer mixture into a preparatory container; retain 40% of the mixture in the reaction kettle as the bottom material for the polymerization reaction.

[0052] S14. Polymerization reaction: Raise the temperature of the reaction kettle to 78 - 80 °C, add 15% - 20% of the initiator solution to initiate the polymerization reaction; observe the reaction system. When the system starts to react, i.e., when reflux appears in the condenser, slowly drop the remaining initiator solution into the reaction kettle within 3 - 4 h, while maintaining the reaction temperature at 78 - 80 °C. The remaining 60% of the monomer mixture is evenly dropped within the same time; after the dropping is completed, continue to keep the temperature for reaction for 1 - 2 h to allow the monomers to fully react; after the reaction is completed, cool to below 30 °C, filter, and collect the material to obtain a high-temperature resistant acrylate-based pressure-sensitive adhesive.

[0053] The antioxidant is one or more of hindered phenol antioxidants and phosphate antioxidants; the curing agent is one of epoxy curing agent GA240 and isocyanate curing agent L75, and the diluent is ethyl acetate.

[0054] The preparation of the high-temperature resistant acrylate pressure-sensitive adhesive includes the following steps:

[0055] S21. Place the high-temperature resistant acrylate-based pressure-sensitive adhesive in a stirring kettle, and at a stirring speed of 300 - 700 revolutions per minute, sequentially add the curing agent and the antioxidant and stir for 30 - 60 min until the additives are completely dispersed evenly in the polymer emulsion.

[0056] S22. Let it stand and filter the mixed glue solution to obtain the high-temperature resistant acrylate pressure-sensitive adhesive.

[0057] A preparation method of a high-temperature resistant double-sided tape includes the following steps:

[0058] Step 1. Uniformly coat the high-temperature resistant acrylate pressure-sensitive adhesive on a high-temperature resistant Grax release paper through a coating process. Send the coated wet glue film into a continuous drying oven to fully volatilize the solvent, then laminate it onto a high-temperature resistant cotton paper substrate, and wind up the semi-finished product. The dry glue coating thickness is 25 - 45 μm, the drying temperature is 50 - 120 °C, and the drying time is 5 minutes; the high-temperature resistant cotton paper substrate uses 14 g cotton paper, and the thickness of the high-temperature resistant cotton paper substrate is 20 - 25 μm.

[0059] Step 2: Uniformly coat the high-temperature resistant acrylate pressure-sensitive adhesive on the release film through a coating process. After drying the coated wet adhesive film in an oven under the above conditions, laminate it on the other side of the semi-finished tape cotton paper substrate and wind it up to obtain a high-temperature resistant double-sided tape. The dry adhesive coating thickness is 25 - 45 μm, the drying temperature is 50 - 120 °C, and the drying time is 5 minutes.

[0060] Step 3: Place the wound tape in an environment at 40 °C for curing for more than 48 hours to completely cure the pressure-sensitive adhesive and obtain the finished high-temperature resistant double-sided tape.

[0061] The following are the usage amounts of the formula raw materials for each example.

[0062] Example 1

[0063] The usage amounts of the basic adhesive raw materials (in parts by mass) are as follows:

[0064] Butyl acrylate, 23 parts

[0065] 2-Ethylhexyl acrylate, 68 parts

[0066] Vinyl acetate, 5 parts

[0067] Acrylic acid, 2 parts

[0068] 2-Hydroxyethyl acrylate, 2 parts

[0069] Maleimide, 7.5 parts

[0070] 2,2'-Azobis(2-methylpropionitrile), 0.3 part

[0071] Ethyl acetate, 60 parts

[0072] The usage amounts of the pressure-sensitive adhesive raw materials (in parts by mass) are as follows:

[0073] Basic adhesive, 100 parts

[0074] Antioxidant 1010, 0.15 part

[0075] Antioxidant 168, 0.15 part

[0076] Curing agent L-75, 0.3 part

[0077] Ethyl acetate, 30 parts.

[0078] Example 2

[0079] The usage amounts of the basic adhesive raw materials (in parts by mass) are as follows:

[0080] Butyl acrylate, 23 parts

[0081] 2-Ethylhexyl acrylate, 67 parts

[0082] Vinyl acetate, 5 parts

[0083] Acrylic acid, 2 parts

[0084] Hydroxyethyl acrylate, 2 parts

[0085] Maleimide, 2.5 parts

[0086] 2,2'-Azobis(2-methylpropionitrile), 0.3 part

[0087] Ethyl acetate, 55 parts

[0088] The dosage (parts by mass) of the pressure-sensitive adhesive raw materials is as follows:

[0089] Base rubber, 100 parts

[0090] Antioxidant 1010, 0.15 part

[0091] Antioxidant 168, 0.15 part

[0092] Curing agent L-75, 0.3 part

[0093] Ethyl acetate, 30 parts.

[0094] Example 3

[0095] The dosage (parts by mass) of the base rubber raw materials is as follows:

[0096] Butyl acrylate, 22 parts

[0097] 2-Ethylhexyl acrylate, 65 parts

[0098] Vinyl acetate, 5 parts

[0099] Acrylic acid, 2 parts

[0100] Hydroxyethyl acrylate, 2 parts

[0101] Maleimide, 5 parts

[0102] 2,2'-Azobis(2-methylpropionitrile), 0.3 part

[0103] Ethyl acetate, 55 parts

[0104] The dosage (parts by mass) of the pressure-sensitive adhesive raw materials is as follows:

[0105] Base rubber, 100 parts

[0106] Antioxidant 1010, 0.15 part

[0107] Antioxidant 168, 0.15 part

[0108] Curing agent L-75, 0.3 part

[0109] Ethyl acetate, 30 parts.

[0110] Example 4

[0111] The dosage of the base glue raw materials (parts by mass) is as follows:

[0112] Butyl acrylate, 21 parts

[0113] 2-Ethylhexyl acrylate, 63 parts

[0114] Vinyl acetate, 5 parts

[0115] Acrylic acid, 2 parts

[0116] 2-Hydroxyethyl acrylate, 2 parts

[0117] N-Vinylpyrrolidone, 7.5 parts

[0118] 2,2'-Azobis(2-methylpropionitrile), 0.3 part

[0119] Ethyl acetate, 60 parts

[0120] The dosage of the pressure-sensitive adhesive raw materials (parts by mass) is as follows:

[0121] Base glue, 100 parts

[0122] Antioxidant 1010, 0.15 part

[0123] Antioxidant 168, 0.15 part

[0124] Curing agent L-75, 0.3 part

[0125] Ethyl acetate, 30 parts.

[0126] Example 5

[0127] The dosage of the base glue raw materials (parts by mass) is as follows:

[0128] Butyl acrylate, 20 parts

[0129] 2-Ethylhexyl acrylate, 61 parts

[0130] Vinyl acetate, 5 parts

[0131] Acrylic acid, 2 parts

[0132] 2-Hydroxyethyl acrylate, 2 parts

[0133] Maleimide, 10 parts

[0134] 2,2'-Azobis(2-methylpropionitrile), 0.3 part

[0135] Ethyl acetate, 65 parts

[0136] The dosage of the pressure-sensitive adhesive raw materials (parts by mass) is as follows:

[0137] Base glue, 100 parts

[0138] Antioxidant 1010, 0.15 parts

[0139] Antioxidant 168, 0.15 parts

[0140] Curing agent L-75, 0.3 parts

[0141] Ethyl acetate, 30 parts.

[0142] Comparative Example 1

[0143] This comparative example was carried out with reference to Example 4, in which the curing agent was replaced with zirconium acetylacetonate (ZrACA), and the other components and their preparation methods were the same as those described above.

[0144] Comparative Example 2

[0145] This comparative example was carried out with reference to Example 1, in which the curing agent was replaced with an epoxy curing agent (GA240), and the other components and their preparation methods were the same as those described above.

[0146] Comparative Example 3

[0147] This comparative example was carried out with reference to Example 1, in which the bottom material in the kettle before the start of the basic rubber polymerization reaction was changed from 40% to 20%, and the other components and their preparation methods were the same as those described above.

[0148] Comparative Example 4

[0149] This comparative example was carried out with reference to Example 1, in which the bottom material in the kettle before the start of the basic rubber polymerization reaction was changed from 40% to 80%, and the other components and their preparation methods were the same as those described above.

[0150] Comparative Example 5

[0151] This comparative example was carried out with reference to Example 1, in which no antioxidant was contained, and the other components and their preparation methods were the same as those described above.

[0152] Comparative Example 6

[0153] This comparative example was carried out with reference to Example 1, in which no curing agent was contained, and the other components and their preparation methods were the same as those described above.

[0154] The adhesive tapes prepared in each example and comparative example were subjected to performance tests. The specific test methods are as follows, and the measured results are shown in Table 1.

[0155] (1) 180° peel strength: According to GB / T 2792—2014 "Test Method for Peel Strength of Adhesive Tapes", it was measured using a peel strength tensile testing machine (the tape width was 25 mm, a 25-μm PET substrate replacement film was used for back sticking for reinforcement, and the peel rate was 300 mm / min);

[0156] (2) Initial adhesion: Measured according to the method of GB / T4582 - 2002. Prepare a 100mm×100mm tape sample and stick it on the inclined plane of the instrument. Then release steel balls with specified numbers and different diameters from the standard line of the 30° inclined plane and let them roll freely. Select a suitable steel ball so that it stops completely on the tape, and use the number of this steel ball to represent the initial adhesion performance of the pressure - sensitive tape;

[0157] (3) Holding power: According to GB / T 4851—2014, hang the specimen (the width of the specimen tape is 25mm, and a 25μm PET substrate replacement film back - sticker is used for reinforcement) vertically on the test rack. Hang a weight of 1000g at room temperature and a weight of 500g under the condition of 85℃. The holding time of the pressure - sensitive adhesive is characterized by the time when the adhered specimen completely detaches;

[0158] (4) Aging performance test: After accelerated aging tests (①85℃ / 85%RH / 168H, ②80℃ / 226H, ③ - 40℃ / 48H), observe its appearance and test the 180° peel strength;

[0159] (7) Heat - resistance test; Wipe the stainless - steel plate clean with absorbent cotton dipped in absolute ethanol. Uniformly stick the specimen (the tape width is 25mm, and a 25μm PI substrate replacement film back - sticker is used for reinforcement) on the stainless - steel plate, put it into the oven, bake it at high temperature (160℃ - 240℃) for 2H, then take it out and cool it to room temperature. Then slowly peel the tape and observe the surface condition of the stainless - steel plate, mainly observing the residual glue situation on the test steel plate. If there is no residual glue on the test steel plate, it is represented by the symbol "-"; if there is residual glue but it is not serious, it is represented by the symbol "+"; if there is residual glue and it is relatively serious, it is represented by the symbol "++"; if there is residual glue and it is very serious, it is represented by the symbol "+++".

[0160] Table 1: Test results of tape performance

[0161]

[0162] From the above test results, it can be seen that for the high - temperature - resistant double - sided tape prepared by the pressure - sensitive adhesive provided by the present invention, the 180° peel force can reach more than 15N / 25mm; its holding power can reach more than 72H, and its high - temperature resistance, aging resistance and antioxidant performance are excellent.

[0163] It can be seen from Examples 1, Comparative Examples 1, 2 and 6 that under the same test conditions: after being placed for 2 h under different temperature conditions, adding two curing agents, L75 and GA240, can greatly improve their high-temperature resistance. This is because increasing the crosslinking degree in the PSA structure keeps the polymer molecular chains in a relatively stable state under high-temperature conditions; when using ZrACA, its heat resistance is not ideal. This is because the curing principle of ZrACA is mainly the ionic chelation between ZrACA and -COOH in the PSA structure to form crosslinks, while the crosslinks formed by L75 and GA240 are stable chemical bonds. Therefore, comparing the coordination bonds formed by ZrACA in terms of bond energy, the bond energy is weaker than that formed by L75 and GA240.

[0164] It can be seen from Examples 1-5 that the heat-resistant monomers, MAL and NVP, in PSA can improve the heat resistance of PSA, and the heat resistance of PSA gradually increases with the increase in the amount of maleimide. This is attributed to the fact that maleimide has a cyclic group, which can increase the rigidity of PSA. At the same time, the imide group of maleimide and the hydroxyl groups in other monomers are prone to form hydrogen bonds, increasing the degree of physical crosslinking and reducing the free mobility of molecular chains, playing an important role in improving the heat resistance of PSA.

[0165] The initial adhesion of PSA decreases with the increase in the amount of maleimide. The reason is that a large amount of maleimide participates in the reaction system, making PSA have a higher Tg. Therefore, PSA becomes harder, reducing its viscosity and thus the initial adhesion of PSA. The peel strength of PSA first increases and then decreases with the increase in the amount of maleimide. When the amount of maleimide is 7.5%, the 180° peel strength reaches the maximum. This is mainly because before the amount of maleimide reaches 7.5%, the wettability of the PSA system increases, gradually increasing the peel strength at the interface. However, when the amount of maleimide exceeds 7.5%, the cohesive strength of PSA increases too much, reducing the viscosity of PSA and causing a sharp drop in the peel strength.

[0166] It can be known from Example 1, Comparative Example 2 and Comparative Example 3 that the 180° peel force first increases and then decreases with the increase in the bottom material of the kettle. When the bottom material of the kettle is 40%, the peel strength reaches the maximum value. This is because as the amount of the bottom material of the kettle increases, the molecular weight of the system gradually increases. With the increase in molecular weight, it is not easy to wet the surface of the adherend. Therefore, when the amount of the bottom material of the kettle continues to increase, PSA will lose its flexibility, ultimately leading to a decrease in the peel strength.

[0167] It can be seen from Example 1 and Comparative Example 5 that the addition of antioxidants can significantly improve the antioxidant performance of PSA.

[0168] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high temperature resistant double-sided tape, comprising a double-sided tape body, characterized in that: The double-sided adhesive tape body comprises a cotton paper substrate layer (3), and high-temperature resistant acrylic pressure-sensitive adhesive layers (2) are provided on both sides of the cotton paper substrate layer (3), wherein a double-silicon glassine release paper (1) is provided on the outer side of one of the high-temperature resistant acrylic pressure-sensitive adhesive layers (2), and a single-silicon release film (4) is provided on the outer side of the other high-temperature resistant acrylic pressure-sensitive adhesive layer (2).

2. A high temperature resistant double-sided adhesive tape according to claim 1, characterized in that: The preparation of the high temperature resistant acrylic pressure sensitive adhesive layer (2) comprises the following steps: S1. Provide a high temperature resistant acrylic base pressure sensitive adhesive, comprising the following raw materials in parts by weight: 3-10 parts of hard monomer, 60-95 parts of soft monomer, 3-8 parts of functional monomer, 0.2-0.6 parts of initiator, 3-15 parts of high temperature resistant modified monomer, and 30-80 parts of organic solvent; S2. Prepare a high temperature resistant acrylic pressure-sensitive adhesive through a high temperature resistant acrylic base pressure-sensitive adhesive, comprising the following raw materials in parts by weight: 100 parts of a heat resistant acrylic base pressure-sensitive adhesive, 0.2-1.5 parts of a curing agent, 0.1-0.3 parts of an antioxidant, and 20-45 parts of a diluent.

3. A high temperature resistant double-sided adhesive tape according to claim 2, characterized in that: The hard monomer is one or more of methyl acrylate, vinyl acetate, styrene, acrylamide, acrylonitrile, and methyl methacrylate; The soft monomer is one or more of butyl acrylate, isooctyl acrylate, and ethyl acrylate; The functional monomer is one or more of acrylic acid, hydroxyethyl acrylate, N-hydroxymethyl acrylamide, hydroxyethyl methacrylate, itaconic acid, and maleic anhydride; The initiator is azobisisobutyl cyanide or benzoyl peroxide; One of the high temperature resistant modified monomers maleimide, N-vinyl pyrrolidone and N-vinyl carbazole; The organic solvent is one of cyclohexane, toluene, acetone and ethyl acetate.

4. A high temperature resistant double-sided adhesive tape according to claim 3, characterized in that: The preparation of the high temperature resistant acrylate based pressure sensitive adhesive comprises the following steps: S11, preparation of raw materials: 60-70 parts of isooctyl acrylate; 15-25 parts of butyl acrylate; 3-8 parts of vinyl acetate; 1-5 parts of acrylic acid; 1-5 parts of hydroxyethyl acrylate; 0.1-0.6 parts of azobisisobutyl cyanide; 1-10 parts of maleimide; 30-80 parts of ethyl acetate; S12, dissolving the initiator: add 1 / 3 of the total amount of the organic solvent and all the initiators into a stirred reactor, continue stirring for 0.5 hours to completely dissolve the initiator, and then fill the initiator solution into a prepared container; S13, monomer mixing: add the remaining 2 / 3 of the total amount of organic solvent and all the formula monomers into a reactor equipped with a stirrer, a thermometer and a reflux condenser; continue stirring for 0.5 hours to mix evenly, release 60% of the monomer mixture and fill it into a prepared container; retain 40% of the mixture in the reactor as the bottom material of the polymerization reaction; S14, polymerization reaction: raise the temperature of the reactor to 78-80°C, add 15%-20% initiator solution to initiate the polymerization reaction; observe the reaction system, when the system starts to react, i.e. when reflux occurs in the condenser, slowly drop the remaining initiator solution into the reactor within 3-4 hours, while maintaining the reaction temperature at 78-80°C, and drop the remaining 60% monomer mixture at a uniform rate within the same time; after the addition is completed, continue to keep warm for 1-2 hours to allow the monomer to fully react; after the reaction is completed, cool to below 30°C and filter to obtain the high temperature resistant acrylate based pressure sensitive adhesive.

5. The high temperature resistant double-sided adhesive tape according to claim 2, characterized in that: The antioxidant is one or more of a hindered phenol antioxidant and a phosphate antioxidant; the curing agent is one of an epoxy curing agent GA240 and an isocyanate curing agent L75; and the diluent is ethyl acetate.

6. The method for preparing a high temperature resistant double-sided adhesive tape according to claim 5, characterized in that: The preparation of the high temperature resistant acrylic pressure sensitive adhesive comprises the following steps: S21, placing the heat-resistant acrylic base pressure-sensitive adhesive in a stirring kettle, adding a diluent, an antioxidant and a curing agent in sequence at a stirring speed of 300-700 rpm, and stirring for 30-60 min until the additives are completely and evenly dispersed in the base pressure-sensitive adhesive solution; S22, standing and filtering the mixed adhesive solution to obtain a high temperature resistant acrylic pressure sensitive adhesive.

7. A method for preparing a high temperature resistant double-sided adhesive tape according to any one of claims 2 to 6, characterized in that: The following steps are involved: Step 1: Evenly coat the high temperature resistant acrylic pressure sensitive adhesive on the high temperature resistant adhesive release paper through a coating process, send the coated wet adhesive film into a continuous drying oven, allow the solvent to fully evaporate, and then adhere it to the heat resistant cotton paper substrate, and roll up the semi-finished product; Step 2: uniformly coating the high temperature resistant acrylic pressure sensitive adhesive on the release film through a coating process, drying the coated wet adhesive film in an oven under the above conditions, and then laminating the coated wet adhesive film on the other side of the semi-finished adhesive tape cotton paper substrate and rolling it up to obtain a high temperature resistant double-sided adhesive tape; Step 3: Place the rolled tape in a 40°C environment and age it for more than 48 hours to allow the pressure-sensitive adhesive to fully cure, thereby obtaining a finished high-temperature resistant double-sided tape.

8. The method for preparing a high temperature resistant double-sided adhesive tape according to claim 7, characterized in that: In the step 1 and the step 2, the thickness of the coated dry glue is 25-45 μm, the drying temperature is 50-120° C., and the drying time is 5 minutes.

9. The method for preparing a high temperature resistant double-sided adhesive tape according to claim 7, characterized in that: The heat-resistant cotton paper substrate is made of 14g cotton paper, and the thickness of the heat-resistant cotton paper substrate is 20-25 μm.

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