Thermal de-viscosity adhesive, preparation method thereof, and thermal de-viscosity adhesive product

Abstract

The present invention relates to a heat-reducing adhesive, a preparation method thereof, and a heat-reducing adhesive product. The raw materials for preparing the heat-reducing adhesive include: 180 to 230 parts of polyacrylate, 1 to 5 parts of a cross-linking agent, and 20 to 50 parts of a first solvent; the raw materials for preparing the polyacrylate include: 60 to 80 parts of a soft monomer, 10 to 30 parts of a hard monomer, 1 to 5 parts of a functional monomer, 25 to 45 parts of a polyacrylate monomer, 0.2 to 0.4 parts of an initiator, and 80 to 100 parts of a second solvent; the two end groups of the polyacrylate monomer are double bonds, and the monomer contains a polycaprolactone structure; the raw materials for preparing the polyacrylate monomer include: 1 to 5 parts of an isocyanate acrylate, 10 to 16 parts of a polycaprolactone diol, 0.01 to 0.05 parts of a water scavenger, 0.05 to 0.1 parts of a polymerization inhibitor, and 10 to 25 parts of a third solvent. The present invention can achieve reversibility, excellent viscosity reduction effect, and no residual adhesive.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesives, in particular to a heat-reducing adhesive and a preparation method thereof, and a heat-reducing adhesive product. Background Art

[0002] Currently, with the rapid development of the electronics industry, adhesive tapes with both protective and adhesive properties, such as heat-resistant and UV-resistant tapes, have also gained popularity. Some types of heat-resistant tapes are disposable, such as heat-expandable tapes, which are more common. These tapes are made by adding a heat-expandable material to a pressure-sensitive adhesive, which expands upon heating to achieve a tack-reducing effect. Other types are reusable. However, traditional heat-resistant tapes either achieve reversibility and tack-reducing properties, but leave less than 5% residual adhesive after tackification, or exhibit a high residual force after tackification, which compromises the tack-reducing effect. Summary of the Invention

[0003] Based on this, it is necessary to provide a thermal deviscosity adhesive and its preparation method and thermal deviscosity adhesive product to address the problem of how to achieve reversibility, excellent deviscosity effect and no residual adhesive.

[0004] A heat-reducing adhesive, wherein the raw materials for preparing the heat-reducing adhesive include the following components in parts by mass:

[0005] Polyacrylate 180-230 parts;

[0006] 1 to 5 parts of a cross-linking agent; and

[0007] 20 to 50 parts of the first solvent;

[0008] The raw materials for preparing the polyacrylate include the following components in parts by mass:

[0009] Soft monomer 60~80 parts;

[0010] 10~30 parts of hard monomer;

[0011] 1~5 parts of functional monomer;

[0012] 25 to 45 parts of polyacrylate monomer;

[0013] 0.2 to 0.4 parts of initiator; and

[0014] 80 to 100 parts of the second solvent;

[0015] Wherein, the two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure;

[0016] The raw materials for preparing the polyacrylate monomer include the following components in parts by mass:

[0017] 1 to 5 parts of isocyanate acrylate;

[0018] 10 to 16 parts of polycaprolactone diol;

[0019] 0.01~0.05 parts of water removal agent;

[0020] 0.05 to 0.1 parts of polymerization inhibitor; and

[0021] 10 to 25 parts of the third solvent.

[0022] In the aforementioned heat-reducing adhesive, isocyanate acrylate and polycaprolactone diol react to form a polyacrylate monomer containing a polycaprolactone structure and having two double bonds at the end. The polyacrylate monomer, soft monomer, hard monomer, and functional monomer react together as monomers to form a polyacrylate, which can be further made into a heat-reducing adhesive. The present invention chemically bonds the polycaprolactone structure within the heat-reducing adhesive. The combination of these components and the aforementioned mass ranges of each component were determined through extensive testing. These combinations and mass ranges enable the heat-reducing adhesive of the present invention to achieve reversibility, excellent viscosity reduction, and no residual adhesive.

[0023] In a feasible implementation, the molecular weight of the polycaprolactone diol is 1000-2000, and the melting point of the polycaprolactone diol is below 60 degrees;

[0024] The isocyanate acrylate includes isocyanate ethyl acrylate.

[0025] In a feasible implementation, the desiccant includes a mixture of one or more of vinyltrimethoxysilane and vinyltriethoxysilane.

[0026] In a feasible implementation, the soft monomer includes a mixture of one or more of isooctyl (meth)acrylate and butyl (meth)acrylate;

[0027] The hard monomer includes a mixture of one or more of methyl (meth)acrylate, styrene and vinyl acetate;

[0028] The functional monomer includes a mixture of one or more of (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, acrylamide and acrylonitrile.

[0029] In a feasible implementation, the initiator includes a mixture of one or more of benzoyl peroxide and azobisisobutyronitrile;

[0030] The first solvent, the second solvent and the third solvent are independently selected from at least one of ethyl acetate, butyl acetate and toluene.

[0031] In a feasible implementation, the raw materials for preparing the heat-reducing adhesive further include 1 to 6 parts of a tackifying resin and 0.1 to 0.5 parts of a color powder, calculated by weight.

[0032] The tackifying resin includes a mixture of one or more of terpene phenolic resin, modified phenolic resin, rosin and petroleum resin.

[0033] A method for preparing any of the above-mentioned heat-reducing adhesives comprises the following steps:

[0034] The dehydrating agent and the third solvent are mixed uniformly at a temperature of 60° C. to 70° C., and then polycaprolactone diol is added. The temperature is raised to 80° C. to 90° C., and after uniform mixing, isocyanate acrylate is added. After sufficient reaction, a polymerization inhibitor is added, and after uniform mixing, a polyacrylate monomer is obtained, wherein the two terminal groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure;

[0035] The polyacrylate monomer, soft monomer, hard monomer, functional monomer, initiator and second solvent are uniformly mixed and fully reacted at a temperature of 60° C. to 90° C. to obtain polyacrylate; and

[0036] The polyacrylate, the first solvent and the cross-linking agent are mixed uniformly at a temperature not higher than 28° C. to obtain a heat-reduced viscosity adhesive.

[0037] In the above-mentioned method for preparing a heat-reducing adhesive, an isocyanate acrylate and a polycaprolactone diol react to form a polyacrylate monomer containing a polycaprolactone structure and two double bonds at the end. The polyacrylate monomer, a soft monomer, a hard monomer, and a functional monomer react together to form a polyacrylate, which is then further made into a heat-reducing adhesive. Using this method for preparing a heat-reducing adhesive, the polycaprolactone structure is chemically bonded to the heat-reducing adhesive. The resulting heat-reducing adhesive is reversible, exhibits excellent viscosity-reducing properties, and is free of residual adhesive.

[0038] In a feasible implementation, the raw materials for preparing the thermal viscosity-reducing adhesive further include 1 to 6 parts of a tackifying resin and 0.1 to 0.5 parts of a color powder, calculated by weight; the preparation method of the thermal viscosity-reducing adhesive includes the following steps: uniformly mixing the polyacrylate, the first solvent, the tackifying resin, the color powder and the cross-linking agent at a temperature not higher than 28° C. to obtain the thermal viscosity-reducing adhesive.

[0039] A heat-reduced viscosity adhesive product comprises any one of the above-mentioned heat-reduced viscosity adhesives.

[0040] In the heat-reducing adhesive product of the technical solution of the present invention, the heat-reducing adhesive can achieve reversibility, excellent viscosity reduction effect and no residual adhesive. Therefore, the heat-reducing adhesive product of the present invention has high 180-degree peel strength and no residual adhesive, which is conducive to wide application.

[0041] In a feasible implementation, the heat-reducing adhesive product is a heat-reducing adhesive tape or a heat-reducing adhesive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention is a flow chart of a method for preparing a heat-reduced viscosity adhesive according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] The raw materials for preparing the heat-reducing adhesive of one embodiment include the following components in parts by mass:

[0046] Polyacrylate 180-230 parts;

[0047] 1 to 5 parts of a cross-linking agent; and

[0048] 20 to 50 parts of the first solvent;

[0049] The raw materials for preparing polyacrylate include the following components in parts by mass:

[0050] Soft monomer 60~80 parts;

[0051] 10~30 parts of hard monomer;

[0052] 1~5 parts of functional monomer;

[0053] 25 to 45 parts of polyacrylate monomer;

[0054] 0.2 to 0.4 parts of initiator; and

[0055] 80 to 100 parts of the second solvent;

[0056] Wherein, the two terminal groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure;

[0057] The raw materials for preparing the polyacrylate monomer include the following components in parts by mass:

[0058] 1 to 5 parts of isocyanate acrylate;

[0059] 10 to 16 parts of polycaprolactone diol;

[0060] 0.01~0.05 parts of water removal agent;

[0061] 0.05 to 0.1 parts of polymerization inhibitor; and

[0062] 10 to 25 parts of the third solvent.

[0063] In the above-mentioned heat-reducing adhesive, isocyanate acrylate and polycaprolactone diol can react to generate a polyacrylate monomer with two terminal double bonds and a polycaprolactone structure. The polycaprolactone diol can be purchased or prepared.

[0064] In the above-mentioned heat-reducing adhesive, the polyacrylate monomer, the soft monomer, the hard monomer and the functional monomer serve as monomers and react to form polyacrylate; the polyacrylate can be further made into heat-reducing adhesive.

[0065] In the present invention, the polycaprolactone structure is connected to the thermal viscosity-reducing adhesive by chemical bonds. The combination of these components and the above-mentioned mass range of each component are determined through a large number of experiments. The above-mentioned combination and mass range enable the thermal viscosity-reducing adhesive of the present invention to achieve reversibility, excellent viscosity-reducing effect and no residual adhesive.

[0066] Based on the above embodiment, the molecular weight of the polycaprolactone diol is 1000-2000, and the melting point of the polycaprolactone diol is below 60 degrees. Furthermore, the polycaprolactone diol is waxy. Optionally, the polycaprolactone diol can be, for example, the 21 series or 22 series crystallizable polycaprolactone diols from Polyren Chemical.

[0067] Based on the aforementioned embodiment, the isocyanate acrylate includes ethyl isocyanate acrylate.

[0068] Based on the aforementioned embodiment, the dehydrating agent comprises a mixture of one or more of vinyltrimethoxysilane and vinyltriethoxysilane. These dehydrating agents are vinyl-containing siloxanes that can remove moisture from solvents and polycaprolactone diols. These dehydrating agents react rapidly with water to form small alcohols and organosilicon monomers with double bonds. These monomers can also undergo free radical polymerization with other monomers. Unreacted small molecules and alcohols can also be volatilized and removed during the drying step, resulting in no byproducts after dehydration. This also eliminates the need for high-temperature dehydration of the polyester, significantly reducing energy consumption.

[0069] Based on the aforementioned embodiment, the soft monomer comprises a mixture of one or more of isooctyl (meth)acrylate and butyl (meth)acrylate; the hard monomer comprises a mixture of one or more of methyl (meth)acrylate, styrene, and vinyl acetate; and the functional monomer comprises a mixture of one or more of (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, acrylamide, and acrylonitrile. The soft monomer is the most important monomer in the synthesis of polyacrylates, producing a polymer with a low glass transition temperature (Tg) and initial tack. The hard monomer, in turn, has a higher glass transition temperature and can copolymerize with the soft monomer. Copolymerization of the hard and soft monomers in the appropriate ratios described above produces a heat-resistant adhesive with high cohesive strength and excellent operating temperature performance. The functional monomer is an olefinic monomer with various functional groups that copolymerizes with both the soft and hard monomers. This allows for a certain degree of crosslinking in the heat-resistant adhesive, improving cohesive strength, heat resistance, and excellent holding power.

[0070] Based on the above embodiment, the initiator includes a mixture of one or more of benzoyl peroxide (BPO) and azobisisobutyronitrile (AIBN). These initiators are free radical initiators with a thermal decomposition temperature below 85°C, which is conducive to initiating the polymerization reaction of the above monomers.

[0071] Based on the above embodiment, the first solvent, the second solvent, and the third solvent are independently selected from at least one of ethyl acetate, butyl acetate, and toluene. These solvents are primarily used for the synthesis, dilution, and dissolution of tackifying resins of heat-reducing adhesives. Preferably, the first and second solvents are ethyl acetate, and the third solvent is butyl acetate, which facilitates controlling the reaction rate.

[0072] Based on the aforementioned embodiment, the raw materials for preparing the thermally debonded adhesive further include, by weight, 1 to 6 parts of a tackifying resin and 0.1 to 0.5 parts of a colorant. The tackifying resin enhances the adhesive's adhesion and initial tack, allowing the bonded materials to bond more tightly together, thereby improving overall connection strength and operational stability. The colorant enhances color development and identification, and can further include other oil-based colors such as red or green.

[0073] Based on the above embodiment, the tackifying resin includes a mixture of one or more of terpene phenolic resin, modified phenolic resin, rosin, and petroleum resin. The rosin may be, for example, 138# rosin. These types of tackifying resins have good compatibility with the thermal detackifying adhesive system of the present invention.

[0074] Based on the aforementioned embodiment, the polymerization inhibitor includes hydroquinone.

[0075] In the aforementioned heat-reducing adhesive, isocyanate acrylate and polycaprolactone diol react to form a polyacrylate monomer containing a polycaprolactone structure and having two double bonds at the end. The polyacrylate monomer, soft monomer, hard monomer, and functional monomer react together as monomers to form a polyacrylate, which can be further made into a heat-reducing adhesive. The present invention chemically bonds the polycaprolactone structure within the heat-reducing adhesive. The combination of these components and the aforementioned mass ranges of each component were determined through extensive testing. These combinations and mass ranges enable the heat-reducing adhesive of the present invention to achieve reversibility, excellent viscosity reduction, and no residual adhesive.

[0076] See Figure 1 The method for preparing a heat-reducing adhesive according to one embodiment of the present invention comprises the following steps:

[0077] S10. Mix the dehydrating agent and the third solvent evenly at a temperature of 60°C to 70°C, then add polycaprolactone diol, raise the temperature to 80°C to 90°C, mix evenly, add isocyanate acrylate, add a polymerization inhibitor after sufficient reaction, and mix evenly to obtain a polyacrylate monomer, wherein the two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure.

[0078] In step S10, isocyanate acrylate and polycaprolactone diol may react to generate a polyacrylate monomer having two terminal double bonds and a polycaprolactone structure. The reaction equation is as follows:

[0079] .

[0080] Furthermore, after adding isocyanate acrylate and fully reacting, before adding the polymerization inhibitor, you can also take samples to measure the solid content and NCO mass fraction. After passing the test, add the polymerization inhibitor. After mixing evenly, you can pass the material through a 200-mesh filter and discharge it into a HDPE barrel, seal it and set aside.

[0081] S20, uniformly mixing the polyacrylate monomer, soft monomer, hard monomer, functional monomer, initiator and second solvent obtained in step S10, and fully reacting them at a temperature of 60° C. to 90° C. to obtain polyacrylate.

[0082] In step S20 , the polyacrylate monomer, the soft monomer, the hard monomer and the functional monomer are used as monomers to react to generate polyacrylate.

[0083] Furthermore, the solid content can be measured after the reaction is fully completed, and qualified materials can be discharged into HDPE barrels and sealed for use.

[0084] S30, uniformly mixing the polyacrylate obtained in step S20, the first solvent, and the cross-linking agent at a temperature not higher than 28°C to obtain a heat-reduced viscosity adhesive.

[0085] In step S30 , the cross-linking agent is used in an appropriate mass fraction, which can ensure that the cross-linking density and Tg of the synthesized heat-reducing adhesive are appropriate, and is conducive to maintaining a relatively good initial peeling force.

[0086] In one feasible implementation, the raw materials for preparing the heat-reducing adhesive further include, by weight, 1 to 6 parts of a tackifying resin and 0.1 to 0.5 parts of a color powder. The preparation method of the heat-reducing adhesive comprises the following steps: uniformly mixing a polyacrylate, a first solvent, a tackifying resin, a color powder, and a crosslinking agent at a temperature not exceeding 28°C to obtain the heat-reducing adhesive. Specifically, the polyacrylate, the first solvent, the tackifying resin, and the color powder are dispersed at high speed in a planetary mixer for 1 hour, during which the temperature is controlled to be not above 28°C; then, the crosslinking agent is added and stirred for 0.5 hours; the solid content is measured; and an appropriate amount of solvent is added to the theoretical value; then, the heat-reducing adhesive is rapidly ground in a three-roll mill; the solid content can be measured again after grinding; and an appropriate amount of solvent is added to the theoretical solid content to obtain the heat-reducing adhesive.

[0087] Among them, the theoretical solid content is 40%~45%. At this time, the adhesion, fluidity and permeability of the heat-reducing adhesive are better, and it is suitable for coating.

[0088] In the above-mentioned method for preparing a heat-reducing adhesive, an isocyanate acrylate and a polycaprolactone diol react to form a polyacrylate monomer containing a polycaprolactone structure and two double bonds at the end. The polyacrylate monomer, a soft monomer, a hard monomer, and a functional monomer react together to form a polyacrylate, which is then further made into a heat-reducing adhesive. Using this method for preparing a heat-reducing adhesive, the polycaprolactone structure is chemically bonded to the heat-reducing adhesive. The resulting heat-reducing adhesive is reversible, exhibits excellent viscosity-reducing properties, and is free of residual adhesive.

[0089] A heat-reduced viscosity adhesive product according to one embodiment includes any one of the above-mentioned heat-reduced viscosity adhesives.

[0090] On the basis of the above-mentioned embodiment, the heat-reducing adhesive product is a heat-reducing adhesive tape or a heat-reducing adhesive film.

[0091] Among them, the heat-reducing adhesive tape can be produced by the following steps: coating the prepared heat-reducing adhesive on a base film such as PET. The thickness of the base film is not limited and can be 50 microns or any other thickness. The thickness of the dry adhesive is controlled to be 20 microns to 30 microns. After drying at 95℃ to 125℃ for 5min to 10min, covering it with a fluorine release film and curing it at 50 degrees for 72h, the heat-reducing adhesive tape can be obtained.

[0092] Among them, the thermal viscosity-reducing adhesive film can be prepared by the following steps: coating the prepared thermal viscosity-reducing adhesive on a fluorine release film, controlling the thickness of the dry adhesive to be 20 microns to 30 microns, drying at 95°C to 125°C for 5min to 10min, covering it with another fluorine release film with different release force, and curing it at 50 degrees for 72h to obtain the thermal viscosity-reducing adhesive film.

[0093] In the heat-reducing adhesive product of the technical solution of the present invention, the heat-reducing adhesive can achieve reversibility, excellent viscosity reduction effect and no residual adhesive. Therefore, the heat-reducing adhesive product of the present invention has high 180-degree peel strength and no residual adhesive, which is conducive to wide application.

[0094] With reference to the above implementation contents, in order to make the technical solution of the present invention more specific, clear and easy to understand, the technical solution of the present invention is now given as an example. However, it should be noted that the content to be protected by the present invention is not limited to the following embodiments.

[0095] The raw materials used in the following examples include: ethyl isocyanate acrylate, reagent grade, manufactured by McLean Biochemical Technology Co., Ltd.; polycaprolactone polyol 2102, manufactured by Polyren Chemical; polycaprolactone polyol 2202, manufactured by Polyren Chemical; vinyltrimethoxysilane, reagent grade, manufactured by McLean Biochemical Technology Co., Ltd.; L-75, manufactured by Covestro; thermal expansion microspheres, 120DU15, manufactured by POLYCHEM.

[0096] Examples 1 to 4, Comparative Example 1 and Comparative Example 3

[0097] The preparation process of the heat-reducing adhesive of Examples 1 to 4, Comparative Example 1 and Comparative Example 3 is as follows:

[0098] Weigh the raw materials according to Table 1. Add the third solvent and dehydrating agent to a dry, dust-free kettle equipped with a reflux system. Raise the temperature to 60°C and stir for 1 hour. Then add polycaprolactone diol and raise the temperature to 90°C. Stir until the polycaprolactone diol is completely melted and dissolved in the third solvent. Stir for 1 hour. Then add isocyanate acrylate and maintain the reaction at 90°C for 5 hours. Samples should be measured for solid content ① and NCO mass fraction. A solid content ① ≥ 48% and an NCO mass fraction ≤ 0.05% are considered acceptable. See Table 2 for specific values. After passing the test, add a polymerization inhibitor. Stir for 30 minutes, filter through a 200-mesh screen, and discharge into a sealed HDPE drum for later use. This yields the polyacrylate monomer.

[0099] Add soft monomer, hard monomer, functional monomer, polyacrylate monomer, second solvent, and initiator to a dry, dust-free autoclave equipped with a reflux device. Use a one-step method to heat and react at 80°C for 8 hours. After the reaction, measure the solid content (②). Specific values ​​are shown in Table 2. Qualified material is discharged into an HDPE barrel, sealed, and set aside for use to obtain polyacrylate.

[0100] The polyacrylate, the first solvent, the tackifying resin and the color powder are dispersed at high speed in a planetary mixer for 1 hour. During this period, the temperature should be controlled not higher than 28°C. Then, the cross-linking agent is added and stirred for 0.5 hour. The solid content is measured and an appropriate amount of the first solvent is added to the theoretical value. Then, the polyacrylate is quickly ground in a three-roll grinder. After grinding, the solid content can be measured again and an appropriate amount of the first solvent is added to the theoretical solid content to obtain a heat-reduced viscosity adhesive.

[0101] Table 1

[0102]

[0103] In Table 1, “ / ” represents none.

[0104] Comparative Example 2

[0105] This comparative example is a comparative example of Example 1, and provides a heat-reducing adhesive and a preparation method thereof. The only difference from Example 1 is that the raw materials are as shown in Table 1, heat-expandable microspheres are used as raw material components, and isocyanate acrylate, polycaprolactone diol, water scavenger, polymerization inhibitor and third solvent are not included. The remaining components are the same;

[0106] The preparation process of the heat-reducing adhesive of Comparative Example 2 is as follows:

[0107] Add soft monomer, hard monomer, functional monomer, second solvent, and initiator to a dry, dust-free autoclave equipped with a reflux device. Use a one-step method and heat-retain at 80°C for 8 hours. After the reaction, measure the solid content (②). Specific values ​​are shown in Table 2. Qualified material is discharged into an HDPE barrel and sealed for later use to obtain polyacrylate.

[0108] The polyacrylate, the first solvent, the heat-expandable microspheres, the tackifying resin and the color powder are dispersed at high speed in a planetary mixer for 1 hour. During this period, attention is paid to temperature control, not higher than 28°C. Then, the cross-linking agent is added and stirred for 0.5 hour. The solid content is measured and an appropriate amount of the first solvent is added to the theoretical value. Then, the mixture is quickly ground on a three-roll grinder. After grinding, the solid content can be measured again, and an appropriate amount of the first solvent is added to the theoretical solid content to obtain the heat-reduced viscosity adhesive of Comparative Example 2.

[0109] Table 2

[0110]

[0111] In Table 2, “ / ” represents none. Since the polycaprolactone polyol and heat-expandable microspheres in Comparative Examples 1 and 2 were added by blending and did not participate in the synthesis of monomers, only conventional monomers were used in the synthesis of polyacrylate.

[0112] Performance testing:

[0113] The heat-reducing adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 were coated on a 50 μm PET film with a thickness of 30 μm. The film was dried under a preset temperature, wherein Examples 1 to 3 and Comparative Examples 1 and 3 were dried at 110°C for 5 min, and Comparative Example 2 was dried at 70°C for 20 min. The film was then coated with a fluorine release film and aged at 50°C for 72 h. The performance was then tested as shown in Table 3.

[0114] The standard adopts GB / T2792-1998. When doing the viscosity reduction test, the tensile gauge fixture is connected to the oven to ensure that the bonded tape completes the test at 80°C, and the residual glue on the steel plate is observed with a microscope.

[0115] Table 3

[0116]

[0117] As can be seen from Table 3, although Comparative Example 1 has good peeling force before and after viscosity reduction, since it is directly added to the acrylic ester for blending, it will lead to the generation of residual glue and oily matter; and although Comparative Example 2 also has good peeling force before viscosity reduction and excellent performance of automatic shedding, no residual glue appears, but it is not repeatable; Comparative Example 3 is the formula after removing the dewatering agent. Although its performance also meets the conditions of use, due to the presence of moisture in the solvent and polycaprolactone itself, it is preferred to heat and vacuum to remove moisture. This step is the key to energy consumption. Also, due to the lack of the presence of the dewatering agent, the synthesized hot viscosity-reducing adhesive lacks a certain wetting effect on the substrate, so its peeling force will be smaller than that of Example 2; Examples 1, 2, 3 and 4 of the present invention use a synthetic method to introduce the polycaprolactone structure, which not only achieves the purpose of having good peeling force before and after viscosity reduction, but also achieves the purpose of being reusable and having no residual glue before and after viscosity reduction. At the same time, the introduction of the dewatering agent greatly reduces the energy consumption required for dehydration, does not produce by-products, and also has a better wetting effect with the substrate.

[0118] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A heat-reducing adhesive, characterized in that: The raw materials for preparing the heat-reducing adhesive include the following components in parts by mass: Polyacrylate 180-230 parts; 1 to 5 parts of a cross-linking agent; and 20 to 50 parts of the first solvent; The raw materials for preparing the polyacrylate include the following components in parts by mass: Soft monomer 60~80 parts; 10~30 parts of hard monomer; 1~5 parts of functional monomer; 25 to 45 parts of polyacrylate monomer; 0.2 to 0.4 parts of initiator; and 80 to 100 parts of the second solvent; Wherein, the two terminal groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure; the polyacrylate monomer is prepared by reacting isocyanate acrylate with polycaprolactone diol in the presence of a water scavenger; The raw materials for preparing the polyacrylate monomer include the following components in parts by mass: 1 to 5 parts of isocyanate acrylate; 10 to 16 parts of polycaprolactone diol; 0.01~0.05 parts of water removal agent; 0.05 to 0.1 parts of polymerization inhibitor; and 10 to 25 parts of the third solvent.

2. The heat-reducing adhesive according to claim 1, characterized in that: The molecular weight of the polycaprolactone diol is 1000-2000, and the melting point of the polycaprolactone diol is below 60 degrees; The isocyanate acrylate includes isocyanate ethyl acrylate.

3. The heat-reducing adhesive according to claim 1, characterized in that: The desiccant comprises a mixture of one or more of vinyltrimethoxysilane and vinyltriethoxysilane.

4. The heat-reducing adhesive according to claim 1, characterized in that: The soft monomer includes a mixture of one or more of isooctyl (meth)acrylate and butyl (meth)acrylate; The hard monomer includes a mixture of one or more of methyl (meth)acrylate, styrene and vinyl acetate; The functional monomer includes a mixture of one or more of (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, acrylamide and acrylonitrile.

5. The heat-reducing adhesive according to claim 1, characterized in that: The initiator includes a mixture of one or more of benzoyl peroxide and azobisisobutyronitrile; The first solvent, the second solvent and the third solvent are independently selected from at least one of ethyl acetate, butyl acetate and toluene.

6. The heat-reducing adhesive according to claim 1, characterized in that: The raw materials for preparing the heat-reducing adhesive further include 1 to 6 parts of tackifying resin and 0.1 to 0.5 parts of color powder in parts by mass; The tackifying resin includes a mixture of one or more of terpene phenolic resin, modified phenolic resin, rosin and petroleum resin.

7. A method for preparing the heat-reducing adhesive according to any one of claims 1 to 6, characterized in that: The steps include: The dehydrating agent and the third solvent are mixed uniformly at a temperature of 60° C. to 70° C., and then polycaprolactone diol is added. The temperature is raised to 80° C. to 90° C., and after uniform mixing, isocyanate acrylate is added. After sufficient reaction, a polymerization inhibitor is added, and after uniform mixing, a polyacrylate monomer is obtained, wherein the two terminal groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure; The polyacrylate monomer, soft monomer, hard monomer, functional monomer, initiator and second solvent are uniformly mixed and fully reacted at a temperature of 60° C. to 90° C. to obtain polyacrylate; as well as The polyacrylate, the first solvent and the cross-linking agent are mixed uniformly at a temperature not higher than 28° C. to obtain a heat-reduced viscosity adhesive.

8. The method for preparing the heat-reducing adhesive according to claim 7, characterized in that: The raw materials for preparing the heat-reducing viscosity adhesive further include 1 to 6 parts of a tackifying resin and 0.1 to 0.5 parts of a color powder in parts by mass. The preparation method of the heat-reducing viscosity adhesive comprises the following steps: uniformly mixing the polyacrylate, the first solvent, the tackifying resin, the color powder and the cross-linking agent at a temperature not higher than 28° C. to obtain the heat-reducing viscosity adhesive.

9. A heat-reduced adhesive product, characterized in that: The invention comprises the heat-reducing viscosity adhesive according to any one of claims 1 to 6.

10. The heat-reduced adhesive product according to claim 9, characterized in that: The thermally debonding adhesive product is a thermally debonding adhesive tape or a thermally debonding adhesive film.

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