A kind of high temperature resistant adhesive tape and preparation method thereof

Abstract

The present application relates to the field of tape formulations, and specifically discloses a high temperature resistant tape and a method for preparing the same. The raw materials of the high temperature resistant tape include, by weight: 160‑200 parts of polyethylene terephthalate, 100‑140 parts of polyimide powder, 100‑150 parts of phenolic resin, 90‑120 parts of polyvinyl butyral, 60‑90 parts of benzene, 40‑60 parts of ethanol, 80‑120 parts of lignin grafted acrylic pressure-sensitive adhesive, and 12‑24 parts of antioxidant. The method for preparing the high temperature resistant tape includes the following steps: S1, preparing a substrate; S2, preparing a phenolic acetal thermosetting adhesive; S3, preparing an adhesive component; S5, preparing a high temperature resistant tape. The high temperature resistant tape prepared in the present application has the characteristics of maintaining stable tape performance and high peel strength under high temperature conditions.

Description

Technical Field

[0001] The present application relates to the field of adhesive tape formulations, and more specifically, to a high temperature resistant adhesive tape and a preparation method thereof. Background Art

[0002] High temperature resistant tapes are mainly used in the electronics industry, including spray painting, paint-baked leather processing, quick-shielding coating, fixing during the manufacturing process of electronic parts, printed circuit boards, and high-temperature processing shielding. The high temperature resistant tapes in related technologies usually use polyimide as the base material and silicone as the adhesive. They have good high temperature resistance and can work for a long time at around 240°C. However, due to the high working environment temperature, such tapes are prone to aging and have safety hazards after being heated. After working at high temperatures for a long time, the peeling strength of the tape is severely reduced, and it is easy to break when peeling the tape. Residual glue remains on the surface of electronic components, and the peeling strength is reduced, affecting the basic performance of the tape, and the usage scenarios are relatively limited. Therefore, it is necessary to develop a high temperature resistant tape whose working performance is not affected by high temperatures. Summary of the invention

[0003] In order to improve the high temperature resistance of the tape so that the tape can maintain the peel strength of the tape under high temperature working conditions, the present application provides a high temperature resistant tape and a preparation method thereof.

[0004] In a first aspect, the present application provides a high temperature resistant adhesive tape, which adopts the following technical solution:

[0005] A high temperature resistant adhesive tape comprises raw materials, in parts by weight, of 160-200 parts of polyethylene terephthalate, 50-70 parts of polyimide powder, 100-150 parts of phenolic resin, 90-120 parts of polyvinyl butyral, 60-90 parts of benzene, 40-60 parts of ethanol, 80-120 parts of lignin grafted acrylic pressure-sensitive adhesive, and 12-24 parts of antioxidant.

[0006] By adopting the above technical scheme, a thermosetting high-temperature resistant adhesive having a phenolic-acetal structure is generated by a condensation reaction of phenolic resin and polyvinyl butyral, and an acrylic pressure-sensitive adhesive is grafted with lignin. The molecular hydrogen bonds between the phenolic hydroxyl group in the lignin and the adjacent methoxyl groups and the intermolecular interactions of polar groups such as hydroxyl, methoxy, carbonyl, and carboxyl groups cause the grafted lignin to self-aggregate to form irregular links, and the adhesive does not melt at high temperatures, maintaining its initial shape. Carbonization occurs at continuous ultra-high temperatures, and the formed carbonized layer can help maintain the shape of the tape. The carbonized layer is not easy to burn, which can not only improve the safety and stability of the tape, but also avoid shrinkage and rupture of the tape, so that the tape can maintain its working performance under high temperature conditions.

[0007] Preferably, the preparation method of the lignin grafted acrylic pressure-sensitive adhesive is as follows: stirring and mixing polyvinyl ether and lignin, slowly raising the reaction temperature, adding ethanol to dissolve, gradually dripping acrylic acid and dicyclopentenyloxyethyl acrylate, and keeping the temperature for reaction for 1-3 hours after the dripping is completed, cooling to 30-40° C., and adding an appropriate amount of plasticizer to adjust the solid content of the product to 45-55%, thereby obtaining the lignin grafted acrylic pressure-sensitive adhesive; wherein the monomer compound of acrylate, vinyl ether, dicyclopentenyloxyethyl acrylate, and lignin are added in a weight ratio of 1:(0.8-1.2):(0.2-0.4):1.

[0008] By adopting the above technical scheme, dicyclopentenyloxyethyl acrylate is activated to provide a chain initiator. Since lignin with a benzene ring is grafted with acrylate and vinyl ether, under the action of hydrogen bonds formed by the mutual aggregation of lignin active groups, the viscosity of the adhesive component is strengthened while the rigidity of the adhesive component is improved. Therefore, greater peel strength and stronger high temperature resistance can be obtained.

[0009] Preferably, the polyvinyl ether is polyvinyl isobutyl ether.

[0010] Preferably, the antioxidant is any one of N-phenylethylnaphthylamine and propyl gallate, and the added amount is 2-4% of the total amount of other raw materials.

[0011] By adopting the above technical solution and using N-phenylethylnaphthylamine and propyl gallate as antioxidants, the surface of the tape can be kept strong and smooth, the tape can be prevented from aging and cracking, and the service life of the tape can be extended.

[0012] Preferably, the phenolic resin is a phenolic resin prepared from butylphenol and 1,3-phthalaldehyde as raw materials.

[0013] By adopting the above technical solution, since butylphenol and 1,3-benzenedialdehyde are used to prepare the phenolic adhesive resin, the resin has a strong rigid structure after condensation, which can improve the high temperature resistance and play the role of a binder.

[0014] Preferably, 20-40 parts by weight of metal nickel powder and 15-30 parts by weight of nickel stearate are also added to the raw material.

[0015] By adopting the above technical solution, nickel stearate is used to disperse metal nickel powder and construct a thermal conductive network, so that the temperature of each part of the tape surface is kept consistent to avoid the problem of excessive temperature at a certain part of the tape, resulting in local differences causing deformation of the tape or even local over-temperature damage. Therefore, the addition of metal nickel powder has the effect of maintaining the stability of the tape performance at high temperatures.

[0016] In a second aspect, the present application provides a method for preparing a high temperature resistant adhesive tape, using the following technical solution:

[0017] A method for preparing a high temperature resistant adhesive tape comprises the following steps:

[0018] S1. Prepare a substrate: mix polyethylene terephthalate and polyimide evenly, and dry and shape them;

[0019] S2, preparing a phenolic-acetal thermosetting adhesive: mixing and stirring a phenolic resin, polyvinyl butyral, benzene, and ethanol to prepare a phenolic-acetal thermosetting adhesive;

[0020] S3, preparing an adhesive component: mixing and stirring the phenolic-acetal thermosetting adhesive and the lignin grafted acrylic pressure-sensitive adhesive in a weight ratio of 1:(1-3) to obtain an adhesive component;

[0021] S4. Prepare a high temperature resistant tape: evenly coat the adhesive component on the substrate, wherein the coating weight ratio of the adhesive component to the substrate is 1:(0.8-1.2), and then package to obtain the high temperature resistant tape.

[0022] Preferably, the step S1 further comprises 20-40 parts by weight of metallic nickel powder and 15-30 parts by weight of nickel stearate.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. Since the present application adopts a condensation reaction of phenolic resin and polyvinyl butyral to generate a thermosetting high temperature resistant adhesive having a phenolic-acetal structure, and adopts lignin grafted acrylic pressure-sensitive adhesive, the molecules of the polar groups in the lignin have mutual aggregation forces, and then a long-chain vinyl polyether is selected and combined with a phenolic-acetal thermosetting adhesive with a strong rigid structure, the melting point of the adhesive component is further improved, and the high temperature resistance is improved.

[0025] 2. In the present application, nickel stearate is preferably used to disperse metal nickel powder and construct a heat-conducting network so that the temperature of each part of the tape surface remains consistent to avoid excessive temperature at a certain part of the tape, resulting in local differences and causing deformation of the tape or even local over-temperature damage. The acrylic pressure-sensitive adhesive grafted with lignin can form a stable carbonized layer at continuous ultra-high temperatures to help maintain the shape of the tape, so that the tape can be smoothly peeled off, thereby maintaining the stability of the tape peeling performance at high temperatures. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0027] The phenol-formaldehyde resin used in this application is 9003-35-4 phenol-formaldehyde resin produced by Hubei Xinhongli Chemical Co., Ltd.;

[0028] The phenolic resin used in this application is PM-9630 phenolic resin glue from Sumitomo Chemical Co., Ltd. of Japan;

[0029] The acrylic pressure-sensitive adhesive used in this application is SK6480 water-based acrylic resin produced by Shanghai Shuai Ke Chemical Co., Ltd.

[0030] Preparation example of lignin grafted acrylic pressure-sensitive adhesive

[0031] Preparation Example 1

[0032] The preparation method of lignin grafted acrylic pressure-sensitive adhesive comprises the following steps: adding 100 kg of polyvinyl isobutyl ether and 100 kg of lignin into a reaction kettle, slowly raising the reaction temperature to 70°C under mechanical stirring, adding 40 kg of ethanol, and keeping the temperature for reaction for 1 hour; gradually dropping 80 kg of acrylic acid and 20 kg of dicyclopentenyloxyethyl acrylate, keeping the temperature for reaction for 1 hour after the dropping is completed, standing and cooling to 40°C, adding 15 kg of ethyl acetate as a plasticizer, and adjusting the solid content of the product to 55%, thereby obtaining the lignin grafted acrylic pressure-sensitive adhesive.

[0033] Preparation Example 2

[0034] The preparation method of the lignin grafted acrylic pressure-sensitive adhesive comprises the following steps: adding 100 kg of polyvinyl isobutyl ether and 100 kg of lignin into a reaction kettle, slowly raising the reaction temperature to 70°C under mechanical stirring, adding 50 kg of ethanol, and keeping the temperature for reaction for 2 hours; gradually dropping 100 kg of acrylic acid and 30 kg of dicyclopentenyloxyethyl acrylate, keeping the temperature for reaction for 1 hour after the dropping is completed, standing and cooling to 35°C, adding 16 kg of ethyl acetate to adjust the solid content of the product to 50%, and obtaining the lignin grafted acrylic pressure-sensitive adhesive.

[0035] Preparation Example 3

[0036] The preparation method of the lignin grafted acrylic pressure-sensitive adhesive comprises the following steps: adding 100 kg of polyvinyl isobutyl ether and 100 kg of lignin into a reaction kettle, slowly raising the reaction temperature to 70°C under mechanical stirring, adding 60 kg of ethanol, and keeping the temperature for reaction for 3 hours; gradually dropping 120 kg of acrylic acid and 40 kg of dicyclopentenyloxyethyl acrylate, keeping the temperature for reaction for 1 hour after the dropping is completed, standing and cooling to 40°C, adding 15 kg of ethyl acetate, and adjusting the solid content of the product to 45%, thereby obtaining the lignin grafted acrylic pressure-sensitive adhesive.

[0037] Example

[0038] Example 1

[0039] A method for preparing a high temperature resistant adhesive tape comprises the following steps:

[0040] S1. Prepare substrate: mix 20 kg of nickel powder, 15 kg of nickel stearate, 200 kg of polyethylene terephthalate and 70 kg of polyimide powder, stir evenly, and dry to shape;

[0041] S2, preparing a phenolic-acetal thermosetting adhesive: 100 kg of phenolic resin, 90 kg of polyvinyl butyral, and 90 kg of benzene were mixed and stirred to prepare a phenolic-acetal thermosetting adhesive;

[0042] S3, preparing an adhesive component: 50 kg of phenolic-acetal thermosetting adhesive, 50 kg of lignin grafted acrylic pressure-sensitive adhesive prepared in Preparation Example 1, and 12 kg of propyl gallate were mixed and stirred to obtain an adhesive component;

[0043] S4. Preparing a high temperature resistant adhesive tape: coating 100 kg of the adhesive component on 80 kg of the substrate, and then packaging to obtain the high temperature resistant adhesive tape.

[0044] Example 2

[0045] A method for preparing a high temperature resistant adhesive tape comprises the following steps:

[0046] S1, preparing a substrate: 30 kg of metallic nickel powder, 22.5 kg of nickel stearate, 180 kg of polyethylene terephthalate and 60 kg of polyimide powder were mixed and stirred evenly, and dried and shaped;

[0047] S2, preparing a phenolic-acetal thermosetting adhesive: 125 kg of phenolic resin, 105 kg of polyvinyl butyral, and 75 kg of benzene were mixed and stirred to prepare a phenolic-acetal thermosetting adhesive;

[0048] S3, preparing an adhesive component: 50 kg of phenolic-acetal thermosetting adhesive, 50 kg of lignin grafted acrylic pressure-sensitive adhesive prepared in Preparation Example 2, and 18 kg of propyl gallate were mixed and stirred to obtain an adhesive component;

[0049] S5. Preparing a high temperature resistant adhesive tape: coating 100 kg of the adhesive component on 100 kg of the substrate, and then packaging to obtain the high temperature resistant adhesive tape.

[0050] Example 3

[0051] A method for preparing a high temperature resistant adhesive tape comprises the following steps:

[0052] S1, preparing a substrate: 40 kg of nickel powder, 30 kg of nickel stearate, 160 kg of polyethylene terephthalate and 50 kg of polyimide were mixed and stirred evenly, and dried and shaped;

[0053] S2, preparing a phenolic-acetal thermosetting adhesive: 150 kg of phenolic resin, 120 kg of polyvinyl butyral, and 60 kg of benzene were mixed and stirred to prepare a phenolic-acetal thermosetting adhesive;

[0054] S3, preparing an adhesive component: 50 kg of phenolic-acetal thermosetting adhesive, 150 kg of lignin grafted acrylic pressure-sensitive adhesive prepared in Preparation Example 3 and 24 kg of propyl gallate were mixed and stirred to obtain an adhesive component;

[0055] S5. Preparing a high temperature resistant adhesive tape: coating 100 kg of the adhesive component on 120 kg of the substrate, and then packaging to obtain the high temperature resistant adhesive tape.

[0056] Example 4

[0057] The method of Example 1 was followed, except that the aldehyde of the phenolic resin used to prepare the phenolic-acetal thermosetting adhesive was replaced by formaldehyde in an equal amount.

[0058] Example 5

[0059] The method of Example 1 was followed, except that an equal amount of polyvinyl isobutyl ether was replaced by polyvinyl ether when preparing the lignin grafted acrylic pressure-sensitive adhesive.

[0060] Example 6

[0061] The method of Example 1 is followed, except that no metallic nickel powder and nickel stearate are added to the raw materials.

[0062] Example 7

[0063] The method of Example 1 is followed, except that an equal amount of nickel stearate is replaced by nickel powder, that is, nickel stearate is not added to the raw material.

[0064] Comparative Example

[0065] Comparative Example 1

[0066] The method of Example 1 is followed, except that an equal amount of the lignin grafted acrylic pressure-sensitive adhesive in the adhesive component of step S3 is replaced by acrylic pressure-sensitive adhesive.

[0067] Comparative Example 2

[0068] The method of Example 1 is followed, except that the phenol-acetal thermosetting adhesive in the adhesive component of step S3 is replaced by an equal amount of phenol-formaldehyde resin.

[0069] Comparative Example 3

[0070] The method of Example 1 is followed, except that the phenolic-acetal thermosetting adhesive in the adhesive component of step S3 is replaced by an acrylic pressure-sensitive adhesive in equal amounts.

[0071] Comparative Example 4

[0072] The method of Example 1 is followed, except that the grafted lignin pressure-sensitive adhesive in the adhesive component of step S3 is replaced by an equal amount of a phenolic-acetal thermosetting adhesive.

[0073] Performance testing

[0074] 1. Peel strength test

[0075] 2. High temperature resistance test

[0076] Detection Methods

[0077] 1. Peel strength test: The 180° peel strength test refers to GB / T 2792-1998 standard, stainless steel is used as the test substrate, and the test is carried out using an electronic tensile testing machine. The peel strength test results are shown in Table 1;

[0078] 2. High temperature resistance test: The high temperature resistant tapes prepared in the examples and comparative examples were tested. The tapes were pasted on steel plates and placed in ovens at different temperatures for 20 minutes. After being taken out and cooled, the tapes were torn off at a uniform speed. The steel plates were observed for residual adhesive. The highest temperature at which no residual adhesive appeared was set as the tolerance temperature. The high temperature resistance test results are shown in Table 1.

[0079] Table 1

[0080]

[0081] Combining the performance test results of Example 1 and Example 4, it can be seen that the tape prepared by reacting phenolic resin using formaldehyde as raw material has a lower maximum tolerance temperature than the high-temperature resistant tape prepared in Example 1 of the present application, resulting in a decrease in the high-temperature resistance of the tape.

[0082] Combining the performance test results of Example 1 and Example 5, it can be seen that the tape prepared by grafting polyethylene ether with lignin and acrylate as raw material has a lower maximum tolerance temperature than the high temperature resistant tape prepared in Example 1 of the present application, resulting in a decrease in the high temperature resistance of the tape.

[0083] Combining the performance test results of Example 1, Example 6 and Example 7, it can be seen that when nickel powder is not added, the tape is prone to local overheating, and cannot quickly and sufficiently conduct heat and dissipate heat, resulting in local damage to the tape and mottled traces of glue after peeling. When nickel stearate is not added, the fluidity and wettability of the nickel powder are poor, which can play a partial heat transfer effect, but the effect in Example 1 is better, and both heat resistance and peel strength performance are better.

[0084] Combining the performance test results of Example 1 and Comparative Example 1, it can be seen that when only acrylic pressure-sensitive adhesive is used without lignin grafting, the maximum tolerance temperature decreases, the adhesive retention area increases, the high temperature resistance decreases, and the peel strength decreases slightly.

[0085] From the performance test results of Example 1 and Comparative Example 2, it can be seen that the tape prepared by mixing phenolic resin and acrylic pressure-sensitive adhesive grafted with lignin as the adhesive component has a reduced polymer chain rigidity and a decreased maximum tolerance temperature, compared with the high-temperature resistant tape prepared in Example 1 of the present application, and the high-temperature resistance of the tape is reduced.

[0086] It can be seen from the performance test results of Example 1 and Comparative Example 3 that the tape made by using only acrylic pressure-sensitive adhesive as the adhesive component cannot increase the melting point and has insufficient high temperature resistance because the adhesive component has no lignin grafting and no high temperature resistant phenolic-acetal thermosetting adhesive, and the high temperature resistance of the tape is significantly reduced.

[0087] Combining the performance test results of Example 1 and Comparative Example 4, it can be seen that the tape prepared by adding only phenolic-acetal thermosetting adhesive as the adhesive component has high temperature resistance, but the peel strength is significantly reduced, and the deterioration of the tape's viscosity will affect the normal use of the high temperature resistant tape.

[0088] It can be seen that the high temperature resistant tape prepared in the embodiment of the present application has a temperature resistance of ≥250°C, can be used in a high temperature environment, and has a peel strength of ≥6N / 25mm, which can meet various performance requirements of the high temperature resistant tape.

[0089] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high temperature resistant tape, characterized in that: The raw materials include, by weight: 160-200 parts of polyethylene terephthalate, 100-140 parts of polyimide powder, 100-150 parts of phenolic resin, 90-120 parts of polyvinyl butyral, 60-90 parts of benzene, 40-60 parts of ethanol, 80-120 parts of lignin grafted acrylic pressure-sensitive adhesive, and 12-24 parts of antioxidant; The preparation method of the lignin grafted acrylic pressure-sensitive adhesive comprises the following steps: stirring and mixing polyvinyl ether and lignin, slowly raising the reaction temperature, adding ethanol to dissolve, gradually dripping acrylic acid and dicyclopentenyloxyethyl acrylate, keeping the temperature for reaction for 1-3 hours after the dripping is completed, cooling to 30-40° C., adding a proper amount of plasticizer to adjust the solid content of the product to 45-55%, and obtaining the lignin grafted acrylic pressure-sensitive adhesive; wherein the monomer compound of acrylate and vinyl ether, dicyclopentenyloxyethyl acrylate and lignin are added in a weight ratio of 1:(0.8-1.2):(0.2-0.4):1; and 20-40 parts by weight of metal nickel powder and 15-30 parts by weight of nickel stearate are also added to the raw materials.

2. A high temperature resistant tape according to claim 1, characterized in that: The polyvinyl ether is polyvinyl isobutyl ether.

3. A high temperature resistant adhesive tape according to claim 1, characterized in that: The antioxidant is any one of N-phenylethylnaphthylamine and propyl gallate.

4. A high temperature resistant adhesive tape according to claim 1, characterized in that: The phenolic resin is a phenolic resin prepared from butylphenol and 1,3-phthalaldehyde as raw materials.

5. The method for preparing a high temperature resistant adhesive tape according to claim 1, characterized in that: The following steps are involved: S1. Prepare a substrate: mix polyethylene terephthalate and polyimide evenly, and dry and shape them; S2, preparing a phenolic-acetal thermosetting adhesive: mixing and stirring a phenolic resin, polyvinyl butyral, benzene, and ethanol to prepare a phenolic-acetal thermosetting adhesive; S3, preparing an adhesive component: mixing and stirring the phenolic-acetal thermosetting adhesive and the lignin grafted acrylic pressure-sensitive adhesive in a weight ratio of 1:(1-3) to obtain an adhesive component; S4. Prepare a high temperature resistant tape: evenly coat the adhesive component on the substrate, wherein the coating weight ratio of the adhesive component to the substrate is 1:(0.8-1.2), and then package to obtain the high temperature resistant tape.

6. The method for preparing a high temperature resistant adhesive tape according to claim 5, characterized in that: The step S1 further comprises 20-40 parts by weight of metal nickel powder and 15-30 parts by weight of stearic acid.

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