Viscosity-reducing adhesive, viscosity-reducing film and preparation method thereof

Abstract

The invention discloses a viscosity-reducing adhesive, a viscosity-reducing film and a preparation method of the viscosity-reducing film, and relates to the technical field of viscosity-reducing films. Wherein the viscosity-reducing adhesive comprises the following components in parts by weight: 100-105 parts of modified acrylic resin; 3 to 5 parts of bismaleimide; 1-2 parts of a photothermal conversion nano factor; 10 to 15 parts of cellulose aerogel microspheres; 2-3 parts of an ionic liquid; 40 to 50 parts of an ethyl acetate / propylene glycol monomethyl ether mixed solvent; according to the technical scheme provided by the invention, the initial stripping force level of the viscosity-reducing film can be effectively improved, meanwhile, the dependence on UV illumination in the viscosity-reducing process is reduced, in addition, a Diels-Alder bond generation reaction is introduced, a dynamic cross-linked network endows the adhesive layer with the self-repairing capability, and then a favorable premise is provided for reutilization of the viscosity-reducing film.

Description

Technical Field

[0001] This application relates to the technical field of anti-adhesion, and in particular to an anti-adhesive adhesive, an anti-adhesive film and a preparation method thereof. Background Art

[0002] During the processing of some products, tapes are needed to fix the raw materials for easy processing, and after processing, the products need to be easily removed without affecting product quality.

[0003] The above tape products are widely used in the fields of electronic packaging, wafer cutting and flexible electronics manufacturing, and are also known as anti-adhesive films. They can provide good bonding strength when bonding protection is required, and can achieve good peeling after processing, reducing damage to processed parts.

[0004] Currently, in the preparation process of traditional anti-adhesive adhesives, the antistatic agents (such as organic lithium / ammonium salts) used in them are prone to decomposition in high-temperature and high-humidity environments, resulting in a significant increase in surface resistance after long-term storage. For example, in the patent document disclosed under the publication number "CN 114085625 A", the adhesive disclosed therein has a peel strength retention rate of less than 70% after aging at 85°C / 85% RH for 1000 hours, making it difficult to meet the long-term stability requirements of precision electronic components; in addition, existing anti-adhesive films generally rely on UV light sources with specific wavelengths and energies to trigger anti-adhesion, and there are usage limitations under some special materials. Summary of the Invention

[0005] In order to solve at least one of the above technical problems, this application provides an anti-adhesive adhesive, an anti-adhesive film and a preparation method thereof.

[0006] In a first aspect, this application provides an anti-adhesive adhesive, which includes by weight:

[0007] 100 - 105 parts of modified acrylic resin;

[0008] 3 - 5 parts of bismaleimide;

[0009] 1 - 2 parts of photothermal conversion nano-factor;

[0010] 10 - 15 parts of cellulose aerogel microspheres;

[0011] 2 - 3 parts of ionic liquid;

[0012] 40 - 50 parts of ethyl acetate / propylene glycol methyl ether mixed solvent.

[0013] In a possible implementation, the modified acrylic resin is an acrylic resin containing furan groups, which is prepared by the following method:

[0014] Dissolve butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing a furan group;

[0015] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1.

[0016] In a possible implementation manner, the photothermal conversion nanofactor includes ITO.

[0017] In a possible implementation manner, the ionic liquid includes one of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium dicyanamide, and trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide.

[0018] In a possible implementation manner, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

[0019] In a second aspect, the present application provides a pressure-sensitive adhesive release film, which includes a base film layer, a heat-pressure-sensitive adhesive layer, and a release layer stacked in sequence. The heat-pressure-sensitive adhesive layer is thermally cured by using the pressure-sensitive adhesive described above.

[0020] In a third aspect, the present application provides a preparation method for preparing the above-mentioned pressure-sensitive adhesive release film. The preparation method includes the following steps:

[0021] S1. Prepare a modified acrylic resin;

[0022] S2. Mix the modified acrylic resin with bismaleimide, stir at a first temperature, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution;

[0023] S3. Under a nitrogen protection atmosphere, add an ionic liquid to the first solution, stir at 40 °C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a pressure-sensitive adhesive;

[0024] S4. Use a high-pressure spraying process to coat the pressure-sensitive adhesive on a substrate to form a heat-pressure-sensitive adhesive layer, then adhere a release film on the heat-pressure-sensitive adhesive layer, and cure to obtain a pressure-sensitive adhesive release film.

[0025] In a possible implementation, in step S2, after mixing the modified acrylic resin with bismaleimide, three-stage heating is carried out in the order of 50°C, 70°C, and 50°C, with each stage lasting 30 minutes, and 0.1% triphenylphosphine is added during the heating process.

[0026] In a possible implementation, in step S4, when spraying the substrate, the substrate temperature is first preheated to 60°C.

[0027] In a possible implementation, in step S4, high-pressure spraying is pulsed, with a frequency of 100 Hz and a pressure of 0.5 MPa.

[0028] Compared with the prior art, the present application includes but is not limited to the following advantages:

[0029] (1) In the present application, the acrylic resin is modified to obtain an acrylic resin containing furan groups. The furan groups provide dynamic covalent bond reaction sites and form Diels-Alder bonds under the cross-linking action of BMI (bismaleimide), which can endow the adhesive layer with self-healing ability; in addition, the adhesion can be controlled by controlling the molecules of the acrylic resin, improving the initial peel strength level of the anti-adhesive film.

[0030] (2) The present application introduces a photothermal conversion nanofactor, specifically ITO nanoparticles, indium tin oxide nanoparticles. Under the irradiation of near-infrared light, the adhesive layer of the anti-adhesive film will be locally heated, triggering the reversible fracture of Diels-Alder bonds, and finally achieving rapid de-adhesion; this solution can reduce the dependence on UV light during the de-adhesion process, thereby expanding its applicable scenarios.

[0031] (3) The generation reaction of Diels-Alder bonds is introduced in this solution, and its dynamic cross-linking network endows the adhesive layer with self-healing ability, providing a favorable premise for the reuse of the anti-adhesive film.

[0032] (4) The present application selects ionic liquids to replace traditional antistatic agents. 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is selected, which has high conductivity, excellent antistatic performance, low viscosity, and is easily dispersed in the resin system; at the same time, it avoids the problems of easy decomposition and insufficient stability of organic lithium salts or ammonium salts in traditional antistatic agents; thus, the anti-adhesive film provided by the present application has multiple properties such as self-healing, long-term antistatic, and excellent weather resistance. Detailed implementation

[0033] To make the objectives, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific implementation manners of the present invention in conjunction with embodiments. The following presents several embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive:

[0034] This application provides a pressure-sensitive adhesive for reducing adhesion, which can be used in the adhesive layer of a pressure-sensitive adhesive film for reducing adhesion.

[0035] Specifically, the pressure-sensitive adhesive for reducing adhesion includes the following components by weight:

[0036] Modified acrylic resin: 100 - 105 parts;

[0037] Bismaleimide: 3 - 5 parts;

[0038] Photothermal conversion nano-factor: 1 - 2 parts;

[0039] Cellulose aerogel microspheres: 10 - 15 parts;

[0040] Ionic liquid: 2 - 3 parts;

[0041] Ethyl acetate / propylene glycol methyl ether mixed solvent: 40 - 50 parts;

[0042] It can be understood that the above components can obtain a pressure-sensitive adhesive for reducing adhesion with excellent performance when combined in the above proportions;

[0043] Specifically, in one implementation manner, the modified acrylic resin is an acrylic resin containing furan groups, which is prepared by the following method:

[0044] Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70°C for 6 hours under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0045] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN (azobisisobutyronitrile) is 20:1.

[0046] It is understandable that in this solution, the acrylic resin is modified, and the modified acrylic resin has furan groups. The carbon-carbon double bond in bismaleimide can react with the furan ring in the furfuryl methacrylate copolymer through a DA reaction, which is a concerted pericyclic reaction and proceeds through a six-membered ring transition state. In the reaction, bismaleimide acts as a dienophile, and its carbon-carbon double bond has high electrophilicity. The furan ring in the furfuryl methacrylate copolymer acts as a diene and has a high electron cloud density. The two undergo a [4+2] cycloaddition reaction to form a new six-membered unsaturated cyclic structure, thus forming a crosslinked network structure. Further, the DA reaction is reversible. Under certain temperature conditions, the reaction product undergoes a retro-Diels-Alder reaction to dissociate the crosslinked structure. That is, in practical applications, the Diels-Alder bond can be reversibly broken by controlling the reaction temperature, ultimately achieving rapid viscosity reduction.

[0047] In addition, under appropriate conditions, the DA reaction can occur again to restore the crosslinked structure, which provides a favorable premise for the self-repair and reuse of the pressure-sensitive adhesive film.

[0048] Specifically, in one of the embodiments, the photothermal conversion nanofactor includes ITO nanoparticles (indium tin oxide nanoparticles). Under the irradiation of near-infrared light, ITO is used to locally heat the adhesive layer of the pressure-sensitive adhesive film, thereby triggering the reversible breakage of the Diels-Alder bond. It is understandable that this solution reduces the dependence on UV light during the viscosity reduction process, thereby expanding the applicable scenarios of the pressure-sensitive adhesive film.

[0049] The technical solutions provided by the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0050] In the following embodiments, unless otherwise specified, all are conventional methods.

[0051] Specifically, in one of the embodiments, the ionic liquid includes one of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium dicyanamide, and trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide.

[0052] Furthermore, the ionic liquid is preferably 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide;

[0053] In the above solution, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide salt is selected in this solution. It has high conductivity and excellent antistatic performance. In addition, it has good compatibility with acrylic resin, can be evenly distributed in the polymer network, and will not cause problems such as phase separation. Further, it can adjust the rheological properties of the adhesive, so that the adhesive can maintain appropriate fluidity and viscosity under different temperature and shear force conditions. For example, it is not easy to flow at high temperature and not easy to harden and become brittle at low temperature, ensuring the use performance of the adhesive in different environments. Furthermore, it has good thermal stability and can remain stable during the preparation process of the adhesive and when encountering high temperature environments during use, and will not decompose or volatilize due to heat. Thus, stability can be achieved during the use process, debonding process, and self-healing recovery process of the release film.

[0054] Specifically, the present application also provides a release film, which includes a base film layer, a thermal debonding adhesive layer, and a release layer stacked in sequence.

[0055] Among them, the thermal debonding adhesive layer is formed by thermally curing the debonding adhesive as described in any of the above.

[0056] Specifically, the present application also provides a preparation method for preparing the above release film. The preparation method includes the following steps:

[0057] S1. Prepare a modified acrylic resin;

[0058] Specifically, butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate are dissolved in ethyl acetate, AIBN is added, and the reaction is carried out at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups.

[0059] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1.

[0060] S2. Mix the modified acrylic resin with bismaleimide, stir at the first temperature, and then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution.

[0061] Specifically, cellulose aerogel microspheres are added in this solution, which has an extremely high specific surface area. This enables it to fully contact and interact with other components in the adhesive, and can effectively improve the performance of the adhesive without increasing too much volume and weight. It can be understood that cellulose aerogel microspheres can be better dispersed in the adhesive system, enhancing the adsorption and binding ability to other substances. In addition, its unique pore structure is also beneficial to the leveling of the adhesive during coating or spraying, thereby making the adhesive layer more uniform.

[0062] S3. Under a nitrogen protection atmosphere, an ionic liquid is added to the first solution. After stirring at 40 °C for 1 h, propylene glycol methyl ether is added to adjust the viscosity to 2000 cP, obtaining a viscosity-reducing adhesive;

[0063] Specifically, adding the ionic liquid under a nitrogen protection atmosphere can effectively avoid the oxidation of the ionic liquid, thereby ensuring the stability of the components; after adding propylene glycol methyl ether, it cooperates with ethyl acetate to control the volatilization efficiency of the solvent. It can be understood that an appropriate volatilization rate helps to form a uniform and dense film structure during the film-forming process of the viscosity-reducing agent. If the solvent volatilizes too slowly, it may cause defects such as bubbles or pinholes in the film; while if the volatilization is too fast, the film surface may be rough, affecting the viscosity-reducing effect and the appearance quality of the film. The mixed solvent can form a high-quality viscosity-reducing film with a reasonable volatilization rate, improving the overall performance of the viscosity-reducing agent; in this solution, propylene glycol methyl ether is added to adjust the viscosity to 2000 cP, and at this viscosity, the subsequent spraying and film-forming effect is better, and the spraying thickness uniformity is better.

[0064] S4. The viscosity-reducing adhesive is coated on the substrate by a high-pressure spraying process, thermally cured to form a viscosity-reducing adhesive layer, and then a release film is adhered to the thermally viscosity-reducing adhesive layer and cured to obtain a viscosity-reducing film.

[0065] Specifically, in one embodiment, in step S2, the first temperature is 60 °C and the reaction time is 2 h;

[0066] In another embodiment, in step S2, after mixing the modified acrylic resin and bismaleimide, three-stage heating is carried out in the order of 50 °C, 70 °C, and 50 °C, each stage for 30 min, and 0.1% triphenylphosphine is added during the heating process;

[0067] In the above solution, this solution adopts a gradient temperature control to promote the forward / backward dynamic equilibrium of the Diels-Alder reaction, thereby effectively promoting the crosslinking density; further, 0.1% triphenylphosphine is further added in this solution, which can effectively catalyze the reaction activation energy, and then the pre-crosslinking time is shortened to 1.5 h; it can be understood that compared with a single reaction temperature of 60 °C, the above three-stage gradient temperature control combined with 0.1% triphenylphosphine can effectively shorten the reaction time and improve the crosslinking density at the same time.

[0068] Specifically, in one embodiment, in step S4, when spraying the substrate, the substrate temperature is first preheated to 60 °C;

[0069] In the above solution, the substrate is preheated first, which intensifies the molecular movement on the substrate surface, increases the surface energy, and enhances the activity. This is conducive to better contact and interaction between the film-forming substances in the anti-adhesive coating and the substrate surface, forming more physical adsorption points and chemical bonds, thus significantly improving the adhesion between the anti-adhesive film and the substrate, enabling the adhesive to adhere more firmly to the substrate surface and not easily fall off. In addition, the preheated substrate can make the anti-adhesive coating sprayed on the surface flow and spread better, and the adhesive has better fluidity on the hot substrate surface and can cover the substrate surface more evenly. Further, preheating the substrate can provide more favorable conditions for the curing reaction, accelerate the reaction rate, enable the anti-adhesive film to reach the final cured state faster, and improve production efficiency. Furthermore, in large-scale production, preheating the substrate can make the anti-adhesive film reach the state where the next process can be carried out faster, reduce the waiting time between processes, make the production process smoother, improve the overall operation efficiency of the production line, and is conducive to realizing continuous and automated production.

[0070] Specifically, in one embodiment, in step S4, the high-pressure spraying is pulsed, with a frequency of 100 Hz and a pressure of 0.5 MPa.

[0071] In the above solution, under the high-pressure pulsed spraying process at the above frequency and pressure, the anti-adhesive film adhesive can be fully broken and refined when ejected, forming very small and uniform droplets. This fine atomization effect helps the adhesive to be more evenly distributed on the surface to be coated, laying a foundation for forming a uniform and flat anti-adhesive film. The pulsed high-pressure spraying makes the contact between the adhesive and the substrate surface more sufficient and close. Under the action of high pressure, the adhesive droplets can better penetrate into the micro-pores and unevenness on the substrate surface, increasing the contact area with the substrate. Combining with the intermittent impact effect brought by the 100 Hz pulse frequency, it helps to break the air film on the substrate surface and form stronger physical and chemical bonding forces between the adhesive and the substrate, improving the adhesion and durability of the anti-adhesive film.

[0072] The following will further elaborate on the anti-adhesive adhesive and anti-adhesive film tape of the present invention through specific examples, but the present invention is not limited only to the content included in the examples. In the following examples, unless otherwise specified, the substances represented by the same name have the same type and quality of substances, and the process steps represented by the same description are the same.

[0073] The materials, reagents, etc. used in the following examples can be obtained from commercial channels without special instructions.

[0074] Example 1

[0075] The anti-adhesive film provided in this embodiment includes a base film layer, a heat anti-adhesive glue layer, and a release layer that are sequentially stacked. The heat anti-adhesive glue layer is formed by thermally curing an anti-adhesive glue. The formula of the anti-adhesive glue is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 40 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0076] The preparation method of the anti-adhesive film provided in this embodiment includes the following steps:

[0077] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0078] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0079] S2. Mix the modified acrylic resin and bismaleimide, perform three-stage heating in the order of 50 °C, 70 °C, and 50 °C, with each stage lasting 30 min, add 0.1% triphenylphosphine during the heating process, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution;

[0080] S3. Under a nitrogen protection atmosphere, add 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide to the first solution, stir at 40 °C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain an anti-adhesive glue;

[0081] S4. Preheat the substrate to 60 °C, coat the glue solution on the substrate using a high-pressure pulsed spraying process, with a frequency of 100 Hz and a pressure of 0.5 MPa, thermally cure to form an anti-adhesive glue layer, then adhere a release film on the heat anti-adhesive glue layer, and cure to obtain an anti-adhesive film.

[0082] Example 2

[0083] The anti-adhesive film provided in this embodiment includes a base film layer, a heat anti-adhesive glue layer, and a release layer that are sequentially stacked. The heat anti-adhesive glue layer is formed by thermally curing an anti-adhesive glue. The formula of the anti-adhesive glue is: 102.5 g of modified acrylic resin, 4 g of bismaleimide, 1.5 g of ITO, 12.5 g of cellulose aerogel microspheres, 2.5 g of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 45 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0084] The preparation method of the anti-adhesive film provided in this embodiment includes the following steps:

[0085] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0086] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0087] S2. Mix the modified acrylic resin with bismaleimide, and perform three-stage heating in the order of 50 °C, 70 °C, and 50 °C, 30 min for each stage. Add 0.1% triphenylphosphine during the heating process, and then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain the first solution;

[0088] S3. Under a nitrogen protection atmosphere, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution, stir at 40 °C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0089] S4. Preheat the substrate to 60 °C, and coat the adhesive solution on the substrate by a high-pressure pulse spraying process, with a frequency of 100 Hz and a pressure of 0.5 MPa, and thermally cure to form a viscosity-reducing adhesive layer. Then adhere a release film on the thermally viscosity-reducing adhesive layer and cure to obtain a viscosity-reducing film.

[0090] Example 3

[0091] The viscosity-reducing film provided in this example includes a base film layer, a thermally viscosity-reducing adhesive layer and a release layer stacked in sequence. The thermally viscosity-reducing adhesive layer is formed by thermally curing a viscosity-reducing adhesive. The formula of the viscosity-reducing adhesive is: 105 g of modified acrylic resin, 5 g of bismaleimide, 2 g of ITO, 15 g of cellulose aerogel microspheres, 3 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 50 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0092] The preparation method of the viscosity-reducing film provided in this example includes the following steps:

[0093] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0094] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0095] S2. Mix the modified acrylic resin with bismaleimide, and conduct three-stage heating in the order of 50°C, 70°C, and 50°C, with each stage lasting 30 minutes. Add 0.1% triphenylphosphine during the heating process, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 minutes to obtain the first solution;

[0096] S3. Under a nitrogen protective atmosphere, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution. After stirring at 40°C for 1 hour, add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0097] S4. Preheat the substrate to 60°C, and apply the adhesive solution to the substrate using a high-pressure pulsed spraying process at a frequency of 100 Hz and a pressure of 0.5 MPa. Thermally cure to form a viscosity-reducing adhesive layer, and then adhere a release film on the thermally viscosity-reducing adhesive layer and cure to obtain a viscosity-reducing film.

[0098] Example 4

[0099] The viscosity-reducing film provided in this example includes a base film layer, a thermally viscosity-reducing adhesive layer, and a release layer stacked in sequence. The thermally viscosity-reducing adhesive layer is formed by thermally curing a viscosity-reducing adhesive. The formula of the viscosity-reducing adhesive is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 40 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0100] The preparation method of the viscosity-reducing film provided in this example includes the following steps:

[0101] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70°C for 6 hours under a nitrogen protective atmosphere to obtain an acrylic resin containing furan groups;

[0102] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0103] S2. Mix the modified acrylic resin with bismaleimide, and conduct three-stage heating in the order of 50°C, 70°C, and 50°C, with each stage lasting 30 minutes. Add 0.1% triphenylphosphine during the heating process, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 minutes to obtain the first solution;

[0104] S3. Under a nitrogen protective atmosphere, add 1-butyl-3-methylimidazolium hexafluorophosphate to the first solution. After stirring at 40°C for 1 hour, add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0105] S4. Preheat the substrate to 60°C, and apply the adhesive solution to the substrate by using a high-pressure pulsed spraying process with a frequency of 100 Hz and a pressure of 0.5 MPa. Then, thermally cure to form a tack-reducing adhesive layer, and adhere a release film on the thermally tack-reducing adhesive layer and cure it to obtain a tack-reducing film.

[0106] Example 5

[0107] The tack-reducing film provided in this example includes a base film layer, a thermally tack-reducing adhesive layer, and a release layer that are sequentially stacked. The thermally tack-reducing adhesive layer is formed by thermally curing a tack-reducing adhesive. The formula of the tack-reducing adhesive is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-hexyl-3-methylimidazolium tetrafluoroborate, and 40 g of an ethyl acetate / propylene glycol methyl ether mixed solvent.

[0108] The preparation method of the tack-reducing film provided in this example includes the following steps:

[0109] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70°C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups.

[0110] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1.

[0111] S2. Mix the modified acrylic resin with bismaleimide, and perform three-stage heating in the order of 50°C, 70°C, and 50°C for 30 min each. During the heating process, add 0.1% triphenylphosphine, and then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution.

[0112] S3. Under a nitrogen protection atmosphere, add 1-hexyl-3-methylimidazolium tetrafluoroborate to the first solution, stir at 40°C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a tack-reducing adhesive.

[0113] S4. Preheat the substrate to 60°C, and apply the adhesive solution to the substrate by using a high-pressure pulsed spraying process with a frequency of 100 Hz and a pressure of 0.5 MPa. Then, thermally cure to form a tack-reducing adhesive layer, and adhere a release film on the thermally tack-reducing adhesive layer and cure it to obtain a tack-reducing film.

[0114] Comparative Example 1

[0115] The anti-adhesive film provided in this embodiment includes a base film layer, a heat anti-adhesive glue layer, and a release layer stacked in sequence. The heat anti-adhesive glue layer is formed by thermosetting an anti-adhesive glue. The formula of the anti-adhesive glue is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 40 g of a mixed solvent of ethyl acetate / propylene glycol methyl ether;

[0116] The preparation method of the anti-adhesive film provided in this embodiment includes the following steps:

[0117] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0118] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0119] S2. Mix the modified acrylic resin and bismaleimide, heat and stir at 60 °C for 1.5 h, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution;

[0120] S3. Under a nitrogen protection atmosphere, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution, stir at 40 °C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain an anti-adhesive glue;

[0121] S4. Preheat the substrate to 60 °C, coat the glue solution on the substrate by a high-pressure pulsed spraying process, with a frequency of 100 Hz and a pressure of 0.5 MPa, thermoset to form an anti-adhesive glue layer, and then adhere a release film on the heat anti-adhesive glue layer and cure to obtain an anti-adhesive film.

[0122] Comparative Example 2

[0123] The anti-adhesive film provided in this embodiment includes a base film layer, a heat anti-adhesive glue layer, and a release layer stacked in sequence. The heat anti-adhesive glue layer is formed by thermosetting an anti-adhesive glue. The formula of the anti-adhesive glue is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of cetyltrimethylammonium bromide, and 40 g of a mixed solvent of ethyl acetate / propylene glycol methyl ether;

[0124] The preparation method of the anti-adhesive film provided in this embodiment includes the following steps:

[0125] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0126] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0127] S2. Mix the modified acrylic resin with bismaleimide, heat and stir at 60 °C for 2 h, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution;

[0128] S3. Under a nitrogen protection atmosphere, add cetyltrimethylammonium bromide to the first solution, stir at 40 °C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0129] S4. Preheat the substrate to 60 °C, coat the adhesive solution on the substrate by using a high-pressure pulse spraying process, with a frequency of 100 Hz and a pressure of 0.5 MPa, thermally cure to form a viscosity-reducing adhesive layer, and then adhere a release film on the thermally viscosity-reducing adhesive layer and cure to obtain a viscosity-reducing film.

[0130] Comparative Example 3

[0131] The viscosity-reducing film provided in this example includes a base film layer, a thermally viscosity-reducing adhesive layer and a release layer stacked in sequence. The thermally viscosity-reducing adhesive layer is formed by thermally curing a viscosity-reducing adhesive. The formula of the viscosity-reducing adhesive is: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 40 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0132] The preparation method of the viscosity-reducing film provided in this example includes the following steps:

[0133] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70 °C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0134] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0135] S2. Mix the modified acrylic resin with bismaleimide, and conduct three-stage heating in the order of 50°C, 70°C, and 50°C, with each stage lasting 30 minutes. Add 0.1% triphenylphosphine during the heating process, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 minutes to obtain the first solution;

[0136] S3. Under the atmosphere of nitrogen protection, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution. After stirring at 40°C for 1 hour, add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0137] S4. Use the high-pressure pulsed spraying process to coat the adhesive solution on the substrate, with a frequency of 100 Hz and a pressure of 0.5 MPa. Thermally cure to form a viscosity-reducing adhesive layer, and then adhere a release film on the thermally viscosity-reducing adhesive layer and cure to obtain a release film.

[0138] Comparative Example 4

[0139] The release film provided in this example includes a base film layer, a thermally viscosity-reducing adhesive layer, and a release layer stacked in sequence. The thermally viscosity-reducing adhesive layer is formed by thermally curing the viscosity-reducing adhesive. The formula of the viscosity-reducing adhesive is: 100 g of modified acrylic resin, 3 g of bismaleimide, 0.5 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 40 g of an ethyl acetate / propylene glycol methyl ether mixed solvent;

[0140] The preparation method of the release film provided in this example includes the following steps:

[0141] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70°C for 6 hours under the atmosphere of nitrogen protection to obtain an acrylic resin containing furan groups;

[0142] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 7:2:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0143] S2. Mix the modified acrylic resin with bismaleimide, and conduct three-stage heating in the order of 50°C, 70°C, and 50°C, with each stage lasting 30 minutes. Add 0.1% triphenylphosphine during the heating process, then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 minutes to obtain the first solution;

[0144] S3. Under the atmosphere of nitrogen protection, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution. After stirring at 40°C for 1 hour, add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive;

[0145] S4. Preheat the substrate to 60°C, and apply the adhesive solution onto the substrate by using a high-pressure pulsed spraying process with a frequency of 100 Hz and a pressure of 0.5 MPa. Then, thermally cure to form a tack-reducing adhesive layer, and adhere a release film onto the thermally tack-reducing adhesive layer and cure it to obtain a tack-reducing film.

[0146] Comparative Example 5

[0147] The tack-reducing film provided in this example includes a base film layer, a thermally tack-reducing adhesive layer, and a release layer which are sequentially stacked. The thermally tack-reducing adhesive layer is formed by thermally curing a tack-reducing adhesive. The formulation of the tack-reducing adhesive is as follows: 100 g of modified acrylic resin, 3 g of bismaleimide, 1 g of ITO, 10 g of cellulose aerogel microspheres, 2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 40 g of a mixed solvent of ethyl acetate / propylene glycol methyl ether;

[0148] The preparation method of the tack-reducing film provided in this example includes the following steps:

[0149] S1. Dissolve butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate in ethyl acetate, add AIBN, and react at 70°C for 6 h under a nitrogen protection atmosphere to obtain an acrylic resin containing furan groups;

[0150] Among them, the ratio of butyl acrylate, 2-hydroxyethyl methacrylate, and furfuryl methacrylate is 10:4:1, and the ratio of furfuryl methacrylate to AIBN is 20:1;

[0151] S2. Mix the modified acrylic resin with bismaleimide, and perform three-stage heating in the order of 50°C, 70°C, and 50°C for 30 min each. During the heating process, add 0.1% triphenylphosphine, and then add cellulose aerogel microspheres and ITO, and ultrasonically disperse for 30 min to obtain a first solution;

[0152] S3. Under a nitrogen protection atmosphere, add 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the first solution, stir at 40°C for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a tack-reducing adhesive;

[0153] S4. Preheat the substrate to 60°C, and apply the adhesive solution onto the substrate by using a high-pressure pulsed spraying process with a frequency of 100 Hz and a pressure of 0.5 MPa. Then, thermally cure to form a tack-reducing adhesive layer, and adhere a release film onto the thermally tack-reducing adhesive layer and cure it to obtain a tack-reducing film.

[0154] Example 6

[0155] Test the tack-reducing films obtained in the above Examples 1-5 and Comparative Examples 1-5 respectively, specifically including

[0156] (1) Initial peel strength: Tested according to the standard of GB / T 7122-1996, with a 25-mm-wide tape attached to a steel plate (unit: gf / 25 mm);

[0157] (2) Peel strength after near-infrared light-induced adhesion reduction: Tested after irradiation at 808 nm, 1 W / cm 2 ;

[0158] (3) Surface resistance: Tested by the four-probe method according to the standard of ASTM D257 (unit: Ω);

[0159] (4) Damp heat aging resistance performance: Stored in an environment of 85°C / 85% RH for 1000 hours, and the peel strength retention rate was tested;

[0160] (5) Self-healing efficiency: After NIR-triggered adhesion reduction, hot pressing repair was carried out at 120°C, and the adhesion recovery rate was tested.

[0161] The specific test results are shown in the following table:

[0162]

[0163]

[0164] Refer to the test results in the above table. It can be seen from the table that for Examples 1-5, the initial peel strength can all reach more than 430 gf / 25 mm, and the peel strength after near-infrared light irradiation can all reach less than 10 gf / 25 mm. It can be seen that the adhesion reduction effect of Examples 1-5 is excellent, and the initial viscosity is also relatively high. Secondly, in the test of damp heat aging resistance, the retention rate of Example 1 is the highest, and its initial peel strength can basically be maintained well. In the test of self-healing efficiency, the self-healing rate of the pressure-sensitive adhesive film in Example 1 can reach 90%, providing a favorable premise for reusing. At the same time, its surface resistance can reach 10 4 Ω, indicating that it also has excellent antistatic performance.

[0165] Furthermore, referring to Example 1 and Comparative Example 1, in the preparation method of Comparative Example 1, in step S2, a modified acrylic resin and bismaleimide were directly stirred at 60°C for 1.5 h. It can be seen from Comparative Example 1 that its initial peel strength decreased, and the surface resistance increased to 10 6 Ω. The damp heat aging resistance performance and self-healing performance both decreased to varying degrees. It is speculated that the stirring time of 1.5 h was insufficient, resulting in insufficient crosslinking degree of the adhesive, affecting subsequent related performances; while in Example 1, although the stirring time was also 1.5 h, under the adjustment of gradient temperature, the crosslinking effect was better.

[0166] Furthermore, referring to Example 1 and Comparative Example 2, Comparative Example 2 uses traditional quaternary ammonium salts as antistatic agents. The initial viscosity of the anti-adhesive film and the anti-adhesive performance after light exposure have decreased, but not significantly. Among them, the decrease in the ability to resist damp heat aging is more obvious, and at the same time, the surface resistance has decreased to a certain extent.

[0167] Furthermore, referring to Example 1 and Comparative Example 3, in step S4 of the preparation method of Comparative Example 3, the substrate was not preheated. The initial viscosity of the prepared anti-adhesive film and the anti-adhesive effect after light exposure are not as good as those of Example 1, but the overall decrease is not large. Among them, the decrease in its resistance to damp heat aging performance and self-healing performance is obvious.

[0168] Furthermore, referring to Example 1 and Comparative Example 4, the addition amount of ITO was reduced in Comparative Example 4. The influence on the initial viscosity of the prepared anti-adhesive film is not obvious, but the influence on the anti-adhesive effect after light exposure is relatively large. In addition, the self-healing performance also decreases significantly.

[0169] Furthermore, referring to Example 1 and Comparative Example 5, in step S1 of Comparative Example 5, the proportion of furfuryl methacrylate was reduced. As can be seen from the above table, there are different degrees of decrease in the test results. Among them, the self-healing performance is greatly affected, only 72%.

[0170] The above description is only a preferred embodiment of the present application, and does not impose any form of limitation on the present application. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application shall fall within the scope of the technical solution of the present application.

Claims

1. A viscosity-reducing adhesive, characterized in that: It includes by weight: 100-105 parts of modified acrylic resin; 3-5 parts of bismaleimide; 1-2 copies of photothermal conversion nanofactor; 10-15 parts of cellulose aerogel microspheres; 2-3 parts of ionic liquid; 40-50 parts of ethyl acetate / propylene glycol methyl ether mixed solvent.

2. The viscosity-reducing adhesive according to claim 1, characterized in that: The modified acrylic resin is an acrylic resin containing a furan group, which is prepared by the following method: Butyl acrylate, hydroxyethyl methacrylate and furan methacrylate were dissolved in ethyl acetate, AIBN was added, and the mixture was reacted at 70°C for 6 hours under a nitrogen atmosphere to obtain an acrylic resin containing a furan group. The ratio of butyl acrylate, hydroxyethyl methacrylate and furan methacrylate is 7:2:1, and the ratio of furan methacrylate to AIBN is 20:

1.

3. The viscosity-reducing adhesive according to claim 2, characterized in that: The photothermal conversion nanofactor includes ITO.

4. The viscosity-reducing adhesive according to claim 2, characterized in that: The ionic liquid includes one of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium dicyanamide salt and trihexyltetradecylphosphonium bis(trifluoromethanesulfonyl)imide salt.

5. The viscosity-reducing adhesive according to claim 4, characterized in that: The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

6. A viscosity-reducing film, characterized in that: The viscosity-reducing film comprises a base film layer, a thermal viscosity-reducing adhesive layer and a release layer which are sequentially stacked, and the thermal viscosity-reducing adhesive layer is formed by thermally curing the viscosity-reducing adhesive according to any one of claims 2 to 5.

7. A method for preparing the viscosity-reducing film according to claim 6, characterized in that: The preparation method comprises the following steps: S1, preparing modified acrylic resin; S2, mixing the modified acrylic resin and bismaleimide, stirring at a first temperature, then adding cellulose aerogel microspheres and ITO, and ultrasonically dispersing for 30 minutes to obtain a first solution; S3. Under a nitrogen protective gas atmosphere, add the ionic liquid to the first solution, stir at 40° C. for 1 h, and then add propylene glycol methyl ether to adjust the viscosity to 2000 cP to obtain a viscosity-reducing adhesive; S4, applying the viscosity-reducing adhesive to the substrate by a high-pressure spraying process, thermally curing to form a viscosity-reducing adhesive layer, and then adhering a release film to the thermal viscosity-reducing adhesive layer, and curing to obtain a viscosity-reducing film.

8. The preparation method according to claim 7, characterized in that: In step S2, after the modified acrylic resin and bismaleimide are mixed, they are heated in three stages in the order of 50° C., 70° C., and 50° C., each stage for 30 minutes, and 0.1% triphenylphosphine is added during the heating process.

9. The preparation method according to claim 7, characterized in that: In step S4, when spraying the substrate, the substrate temperature is preheated to 60°C.

10. The preparation method according to claim 9, characterized in that: In step S4, the high pressure spraying is performed in a pulsed manner with a frequency of 100 Hz and a pressure of 0.5 MPa.

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