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

Abstract

The invention relates to a thermal viscosity-reducing adhesive, a preparation method thereof and a thermal viscosity-reducing adhesive product. The heat-reduced adhesive is prepared from the following raw materials in parts by weight: 180-230 parts of polyacrylate, 1-5 parts of a cross-linking agent and 20-50 parts of a first solvent; the polyacrylate is prepared from the following raw materials: 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 part of an initiator and 80 to 100 parts of a second solvent; two end groups of the polyacrylate monomer are double bonds, and the monomer contains a polycaprolactone structure; the polyacrylate monomer is prepared from the following raw materials in parts by weight: 1 to 5 parts of isocyanate-based acrylate, 10 to 16 parts of polycaprolactone diol, 0.01 to 0.05 part of a water removal agent, 0.05 to 0.1 part of a polymerization inhibitor and 10 to 25 parts of a third solvent. Reversibility can be achieved, the visbreaking effect is excellent, and no adhesive residue exists.

Description

Technical Field

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

[0002] At present, with the rapid development of the electronics industry, thermal de-tackifying tapes, UV de-tackifying tapes and other tapes that have both protective and adhesive properties have also developed. Among them, one type of thermal de-tackifying tape is disposable, such as heat expansion tape, which is to add heat expansion material to the pressure-sensitive adhesive. After heating, the material expands to achieve the effect of de-tackifying. This tape is more common; another type is reusable. However, traditional thermal de-tackifying tapes can either achieve the reversibility and de-tackifying properties of thermal de-tackifying tapes, but after de-tackifying, there will be less than 5% residual adhesive, or the residual force after de-tackifying is large, which affects the de-tackifying effect. Summary of the invention

[0003] Based on this, it is necessary to provide a thermal de-viscosity adhesive and a preparation method thereof and a thermal de-viscosity adhesive product in order to achieve reversibility, excellent de-viscosity 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 terms of weight fraction: Polyacrylate 180-230 parts; 1 to 5 parts of a cross-linking agent; and 20 to 50 parts of the first solvent; Wherein, 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; Polyacrylate monomer 25 to 45 parts; 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; Wherein, 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 dewatering agent; 0.05 to 0.1 parts of polymerization inhibitor; and The third solvent is 10 to 25 parts.

[0005] In the above-mentioned heat-debonding adhesive, the isocyanate group acrylate and the polycaprolactone diol can react to form a polyacrylate monomer with two double-bonded end groups and a polycaprolactone structure; the polyacrylate monomer, the soft monomer, the hard monomer, and the functional monomer are used as monomers together, and after reaction, a polyacrylate is formed; the polyacrylate can be further made into a heat-debonding adhesive. In the present invention, the polycaprolactone structure is connected to the heat-debonding adhesive by means of chemical bonds. The combination of these components and the above-mentioned mass fraction ranges of each component are determined through a large number of experiments. The above combination and mass fraction range enable the heat-debonding adhesive of the present invention to achieve reversibility, excellent debonding effect, and no residual glue.

[0006] In a feasible implementation manner, the molecular weight of the polycaprolactone diol is 1000-2000, and the melting point of the polycaprolactone diol is below 60 degrees; The isocyanate group acrylate includes ethyl isocyanate group acrylate.

[0007] In a feasible implementation manner, the water remover includes one or more mixtures of vinyltrimethoxysilane and vinyltriethoxysilane.

[0008] In a feasible implementation manner, the soft monomer includes one or more mixtures of isooctyl (meth)acrylate and butyl (meth)acrylate; The hard monomer includes one or more mixtures of methyl (meth)acrylate, styrene, and vinyl acetate; The functional monomer includes one or more mixtures of (meth)acrylic acid, (meth)acrylic acid hydroxyethyl ester, (meth)acrylic acid hydroxypropyl ester, acrylamide, and acrylonitrile.

[0009] In a feasible implementation manner, the initiator includes one or more mixtures 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.

[0010] In a feasible implementation manner, calculated by mass, the raw materials for preparing the heat-debonding adhesive further include 1 to 6 parts of tackifying resin and 0.1 to 0.5 parts of color powder; The tackifying resin includes one or more mixtures of terpene phenolic resin, modified phenolic resin, rosin, and petroleum resin.

[0011] A preparation method of any one of the above heat-debonding adhesives includes the following steps: The water remover and the third solvent are mixed evenly 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. After mixing evenly, isocyanate group acrylate is added. After sufficient reaction, an inhibitor is added. After mixing evenly, a polyacrylate monomer is obtained. The two end 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 the second solvent are mixed evenly and react sufficiently at a temperature of 60°C to 90°C to obtain a polyacrylate; and The polyacrylate, the first solvent and the crosslinking agent are mixed evenly under the condition of not higher than 28°C to obtain a heat-softening adhesive.

[0012] In the above preparation method of the heat-softening adhesive, isocyanate group acrylate and polycaprolactone diol react to form a polyacrylate monomer with two end groups being double bonds and containing a polycaprolactone structure; the polyacrylate monomer, soft monomer, hard monomer and functional monomer are used as monomers together and react to form a polyacrylate; the polyacrylate is further made into a heat-softening adhesive. By applying the above preparation method of the heat-softening adhesive, the polycaprolactone structure is connected to the heat-softening adhesive by chemical bonds, and the prepared heat-softening adhesive can achieve reversibility, excellent viscosity reduction effect and no residual glue.

[0013] In a feasible implementation manner, calculated by mass parts, the raw materials for preparing the heat-softening adhesive further include 1 part to 6 parts of tackifying resin and 0.1 part to 0.5 part of color powder; the preparation method of the heat-softening adhesive includes the following steps: the polyacrylate, the first solvent, the tackifying resin, the color powder and the crosslinking agent are mixed evenly under the condition of not higher than 28°C to obtain a heat-softening adhesive.

[0014] A heat-softening adhesive product includes the heat-softening adhesive according to any one of the above.

[0015] In the heat-softening adhesive product of the technical solution of the present invention, the heat-softening adhesive can achieve reversibility, excellent viscosity reduction effect and no residual glue. Therefore, the 180-degree peel strength of the heat-softening adhesive product of the present invention is relatively high and there is no residual glue, which is beneficial to wide application.

[0016] In a feasible implementation manner, the heat-softening adhesive product is a heat-softening adhesive tape or a heat-softening adhesive film. Description of the Drawings

[0017] Figure 1 It is a flowchart of the preparation method of the heat-softening adhesive according to an embodiment of the present invention. Detailed Embodiments

[0018] To make the above objects, features and advantages of the present invention more obvious and understandable, the following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0020] The hot tack reducing adhesive of one embodiment, calculated by mass parts, the raw materials for preparing the hot tack reducing adhesive include the following components: 180 parts to 230 parts of polyacrylate; 1 part to 5 parts of crosslinking agent; and 20 parts to 50 parts of the first solvent; Among them, calculated by mass parts, the raw materials for preparing polyacrylate include the following components: 60 parts to 80 parts of soft monomer; 10 parts to 30 parts of hard monomer; 1 part to 5 parts of functional monomer; 25 parts to 45 parts of polyacrylate monomer; 0.2 parts to 0.4 parts of initiator; and 80 parts to 100 parts of the second solvent; Among them, the two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure; Among them, calculated by mass parts, the raw materials for preparing the polyacrylate monomer include the following components: 1 part to 5 parts of isocyanate group acrylate; 10 parts to 16 parts of polycaprolactone diol; 0.01 part to 0.05 part of water scavenger; 0.05 part to 0.1 part of polymerization inhibitor; and 10 parts to 25 parts of the third solvent.

[0021] In the above hot tack reducing adhesive, the isocyanate group acrylate and the polycaprolactone diol can react to form a polyacrylate monomer with two end groups being double bonds and containing a polycaprolactone structure. Among them, the polycaprolactone diol can be purchased or prepared by oneself.

[0022] In the above-mentioned heat-softening adhesive, polyacrylate monomer, soft monomer, hard monomer and functional monomer together serve as monomers, and polyacrylate is formed after reaction; the polyacrylate can be further made into heat-softening adhesive.

[0023] In the present invention, the polycaprolactone structure is connected to the heat-softening adhesive by means of chemical bonds. The combination of these components and the above mass fraction ranges of each component are determined through a large number of experiments. The above combination and mass fraction range enable the heat-softening adhesive of the present invention to achieve reversibility, excellent viscosity reduction effect and no residual adhesive.

[0024] On the basis of the foregoing embodiments, the molecular weight of the polycaprolactone diol is 1000-2000, and the melting point of the polycaprolactone diol is below 60 degrees. Further, the polycaprolactone diol is waxy. Optionally, the polycaprolactone diol can be, for example, the 21 series or 22 series of crystallizable polycaprolactone diols of Julong Chemistry.

[0025] On the basis of the foregoing embodiments, the isocyanate group acrylate includes ethyl isocyanate group acrylate.

[0026] On the basis of the foregoing embodiments, the water scavenger includes a mixture of one or more of vinyltrimethoxysilane and vinyltriethoxysilane. These types of water scavengers are vinyl-containing siloxanes, which can remove the moisture in the solvent and polycaprolactone diol. These types of water scavengers can react quickly with water to combine and form small molecule alcohols and organic silicon monomers with double bonds. The formed monomers can also undergo free radical polymerization with other monomers. The unreacted small molecules and small molecule alcohols can also be volatilized and removed in the drying step, so as to achieve the purpose of no other by-products after water removal, and also save the step of high-temperature water removal of polyester, greatly saving energy consumption.

[0027] On the basis of the foregoing embodiments, 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, (meth)acrylic acid hydroxyethyl ester, (meth)acrylic acid hydroxypropyl ester, acrylamide and acrylonitrile. Among them, the soft monomer is the most important monomer in the synthesis of polyacrylate, and its function is to produce a polymer with a relatively low glass transition temperature (Tg) and initial tack. The hard monomer can also produce a relatively high glass transition temperature and can copolymerize with the soft monomer. After the hard monomer and the soft monomer copolymerize in the above appropriate ratio, a heat-softening adhesive with relatively high cohesive strength and good service temperature performance can be prepared. The functional monomer is an olefin monomer with various functional groups and can copolymerize with the soft monomer and the hard monomer, which can cause a certain degree of crosslinking of the heat-softening adhesive, improve the cohesive strength, heat resistance performance and excellent holding tack.

[0028] On the basis of the foregoing embodiments, the initiator includes one or more mixtures of benzoyl peroxide (BPO) and azobisisobutyronitrile (AIBN). These types of initiators are free radical initiators with a thermal decomposition temperature below 85°C, which is beneficial to initiating the polymerization reaction of the above-mentioned monomers.

[0029] On the basis of the foregoing embodiments, 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 types of solvents are mainly used for the synthesis of thermal viscosity-reducing adhesives, dilution, dissolution of tackifying resins, etc. Preferably, the first solvent and the second solvent are ethyl acetate, and the third solvent is butyl acetate, which is beneficial to controlling the reaction rate.

[0030] On the basis of the foregoing embodiments, based on parts by mass, the raw materials for preparing the thermal viscosity-reducing adhesive further include 1 to 6 parts of tackifying resin and 0.1 to 0.5 parts of color powder. The tackifying resin is beneficial to enhancing the adhesion ability and initial tack performance of the thermal viscosity-reducing adhesive, enabling the materials to be bonded to be more closely combined together, thereby improving the overall connection strength and use stability. The color powder can better display color and be recognized, and the color powder can further be other oily color powders such as red powder or green powder.

[0031] On the basis of the foregoing embodiments, the tackifying resin includes one or more mixtures of terpene phenolic resin, modified phenolic resin, rosin and petroleum resin. Among them, the rosin can be, for example, 138# rosin. These types of tackifying resins have good compatibility with the thermal viscosity-reducing adhesive system of the technical solution of the present invention.

[0032] On the basis of the foregoing embodiments, the polymerization inhibitor includes hydroquinone.

[0033] In the above thermal viscosity-reducing adhesive, isocyanate group acrylate and polycaprolactone diol can react to form a polyacrylate monomer with two double bond end groups and a polycaprolactone structure; the polyacrylate monomer, soft monomer, hard monomer and functional monomer are used as monomers together, and after reaction, polyacrylate is formed; the polyacrylate can be further made into a thermal viscosity-reducing adhesive. The present invention connects the polycaprolactone structure to the thermal viscosity-reducing adhesive by means of chemical bonds. The combination of these components and the above mass fraction ranges of each component are determined through a large number of experiments. The above combination and mass fraction range enable the thermal viscosity-reducing adhesive of the present invention to achieve reversibility, excellent viscosity-reducing effect and no residual glue.

[0034] Please refer to Figure 1 , a method for preparing a thermal viscosity-reducing adhesive according to an embodiment of the present invention, includes the following steps: S10. Mix the water remover 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, add isocyanate group acrylate after mixing evenly, add an inhibitor after full reaction, and obtain a polyacrylate monomer after mixing evenly. The two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure.

[0035] In step S10, isocyanate group acrylate and polycaprolactone diol can react to form a polyacrylate monomer with two end groups being double bonds and containing a polycaprolactone structure. The reaction equation is as follows: 。

[0036] Furthermore, before adding isocyanate group acrylate and adding an inhibitor after full reaction, it is also possible to sample and measure the solid content and the mass fraction of NCO. After passing the inspection, add an inhibitor, and after mixing evenly, pass through a 200-mesh filter and discharge it into an HDPE barrel for sealing and standby.

[0037] S20. Mix the polyacrylate monomer, soft monomer, hard monomer, functional monomer, initiator and the second solvent obtained in step S10 evenly, and fully react under the temperature condition of 60°C to 90°C to obtain polyacrylate.

[0038] In step S20, the polyacrylate monomer, soft monomer, hard monomer and functional monomer together serve as monomers and react to form polyacrylate.

[0039] Furthermore, after the full reaction, the solid content can be measured, and after passing the inspection, it is discharged into an HDPE barrel for sealing and standby.

[0040] S30. Mix the polyacrylate obtained in step S20, the first solvent and the crosslinking agent evenly under the condition of not higher than 28°C to obtain a heat-softening adhesive.

[0041] In step S30, the mass fraction of the crosslinking agent is appropriate, which can make the crosslinking density of the synthesized heat-softening adhesive appropriate and the Tg appropriate, which is beneficial to maintaining a better initial peeling force.

[0042] In a feasible implementation, by mass parts, the raw materials for preparing the heat-debonding adhesive further include 1 to 6 parts of tackifying resin and 0.1 to 0.5 parts of color powder; the preparation method of the heat-debonding adhesive includes the following steps: mixing polyacrylate, a first solvent, tackifying resin, color powder and a crosslinking agent evenly under the condition of not higher than 28°C to obtain the heat-debonding adhesive. Specifically, polyacrylate, the first solvent, tackifying resin and color powder are highly dispersed in a planetary stirrer for 1 h, during which the temperature is controlled and not higher than 28°C, then the crosslinking agent is added and stirred for 0.5 h, the solid content is measured, and an appropriate amount of solvent is added to reach the theoretical value; then it is quickly ground by a three-roll grinder, and the solid content can be measured again after grinding, and an appropriate amount of solvent is added to reach the theoretical solid content to obtain the heat-debonding adhesive.

[0043] Among them, the theoretical solid content is 40% - 45%. At this time, the adhesion, fluidity and permeability of the heat-debonding adhesive are all relatively excellent and suitable for coating.

[0044] In the above preparation method of the heat-debonding adhesive, isocyanate group acrylate and polycaprolactone diol react to form a polyacrylate monomer with two double bonds at the end groups and containing a polycaprolactone structure; the polyacrylate monomer, soft monomer, hard monomer and functional monomer are used as monomers together and react to form polyacrylate; the polyacrylate is further made into the heat-debonding adhesive. By applying the above preparation method of the heat-debonding adhesive, the polycaprolactone structure is connected to the heat-debonding adhesive in a chemical bond manner, and the prepared heat-debonding adhesive can achieve reversibility, excellent debonding effect and no residual glue.

[0045] A heat-debonding adhesive product in an embodiment includes the heat-debonding adhesive in any of the above.

[0046] On the basis of the foregoing embodiment, the heat-debonding adhesive product is a heat-debonding tape or a heat-debonding adhesive film.

[0047] Among them, the heat-debonding tape can be made by the following steps: coating the prepared heat-debonding adhesive on a base film such as PET, the thickness of the base film is not limited, it can be 50 microns or any other thickness, controlling the dry adhesive thickness to be 20 to 30 microns, drying at 95°C to 125°C for 5 to 10 min, covering a fluorine release film, and curing at 50°C for 72 h to obtain the heat-debonding tape.

[0048] Among them, the heat-debonding adhesive film can be made by the following steps: coating the prepared heat-debonding adhesive on a fluorine release film, controlling the dry adhesive thickness to be 20 to 30 microns, drying at 95°C to 125°C for 5 to 10 min, covering another fluorine release film with a different release force, and curing at 50°C for 72 h to obtain the heat-debonding adhesive film.

[0049] In the heat-debonding adhesive product of the technical solution of the present invention, the heat-debonding adhesive can achieve reversibility, excellent debonding effect and no residual glue. Therefore, the 180-degree peel strength of the heat-debonding adhesive product of the present invention is relatively high and there is no residual glue, which is beneficial to wide application.

[0050] Referring to the above-mentioned implementation content, 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 exemplified. However, it should be noted that the content to be protected by the present invention is not limited to the following embodiments.

[0051] The raw materials used in the following examples include: ethyl isocyanate acrylate, reagent grade, produced by Macklin Biochemical Technology Co., Ltd.; polycaprolactone diol 2102, produced by Julong Chemistry; polycaprolactone diol 2202, produced by Julong Chemistry; vinyltrimethoxysilane, reagent grade, produced by Macklin Biochemical Technology Co., Ltd.; L-75, produced by Covestro; thermally expandable microspheres, 120DU15, produced by POLYCHEM.

[0052] Examples 1 to 4, Comparative Example 1 and Comparative Example 3 The preparation processes of the heat-debonding adhesives of Examples 1 to 4, Comparative Example 1 and Comparative Example 3 are as follows: Weigh each raw material according to Table 1. Add the third solvent and water scavenger into a dry and dust-free kettle with a reflux device, heat up to 60 °C, stir for 1 h, then add polycaprolactone diol, heat up to 90 °C, stir until the polycaprolactone diol is completely melted and completely dissolved in the third solvent, then stir for 1 h, and then add isocyanate group acrylate, keep the temperature at 90 °C and react for 5 h. Take a sample to measure the solid content ① and the NCO mass fraction. If the solid content ① ≥ 48% and the NCO mass fraction ≤ 0.05%, it is considered qualified. The specific values are shown in Table 2. After passing the test, add a polymerization inhibitor, stir for 30 min, then pass through a 200-mesh filter and discharge it into an HDPE barrel for sealing and standby to obtain a polyacrylate monomer; Add soft monomer, hard monomer, functional monomer, polyacrylate monomer, the second solvent and initiator into a dry and dust-free kettle with a reflux device, and carry out a one-step reaction at 80 °C for 8 h. After the reaction is completed, measure the solid content ②. The specific values are shown in Table 2. After passing the test, discharge it into an HDPE barrel for sealing and standby to obtain a polyacrylate; Disperse the polyacrylate, the first solvent, the tackifying resin and the color powder in a planetary stirrer at high speed for 1 h, pay attention to temperature control during this period, not higher than 28 °C, then add the crosslinking agent and stir for 0.5 h, measure the solid content, and supplement an appropriate amount of the first solvent to the theoretical value; then quickly pass through a three-roll mill for grinding. After grinding, the solid content can be measured again, and an appropriate amount of the first solvent is supplemented to the theoretical solid content to obtain a heat-debonding adhesive.

[0053] Table 1 Among them, " / " in Table 1 represents none.

[0054] Comparative Example 2 This comparative example is the comparative example of Example 1, providing a heat-debonding adhesive and its preparation method. The difference from Example 1 is only that: the raw materials are as shown in Table 1, using thermally expandable microspheres as raw material components, and not including isocyanate group acrylate, polycaprolactone diol, water remover, inhibitor, and the third solvent, and the other components are the same; The preparation process of the heat-debonding adhesive of Comparative Example 2 is as follows: Add soft monomer, hard monomer, functional monomer, the second solvent, and initiator into a dry and dust-free kettle with a reflux device, and carry out a one-step reaction at 80 °C for 8 h. After the reaction is completed, measure the solid content ②, and the specific values are shown in Table 2. After passing the inspection, discharge the product into an HDPE barrel and seal it for later use to obtain polyacrylate; Disperse polyacrylate, the first solvent, thermally expandable microspheres, tackifying resin, and color powder in a planetary stirrer at high speed for 1 h. During this period, pay attention to temperature control, not higher than 28 °C, then add the crosslinking agent and stir for 0.5 h, measure the solid content, and supplement an appropriate amount of the first solvent to the theoretical value; then quickly grind through a three-roll mill. After grinding, the solid content can be measured again, and supplement an appropriate amount of the first solvent to the theoretical solid content to obtain the heat-debonding adhesive of Comparative Example 2.

[0055] Table 2 Among them, " / " in Table 2 represents none. Since the polycaprolactone diol and thermally expandable microspheres in Comparative Example 1 and Comparative Example 2 are added by blending and do not participate in the synthesis of monomers, there are only conventional monomers when synthesizing polyacrylate.

[0056] Performance test: Apply the heat-debonding adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 on a 50-μm PET film with a glue thickness of 30 μm; dry under preset temperature conditions. Among them, Examples 1 to 3 and Comparative Examples 1 and 3 are dried at 110 °C for 5 min, and Comparative Example 2 is dried at 70 °C for 20 min; then cover with a fluorine release film and cure at 50 °C for 72 h; then test the performance according to the following method, as shown in Table 3.

[0057] The standard adopts GB / T2792-1998. When doing the debonding test, connect the tensiometer clamp to the oven to ensure that the bonded tape is tested at 80 °C, and observe the residual glue on the steel plate with a microscope.

[0058] Table 3 As can be seen from Table 3, although Comparative Example 1 has good peel strength before and after tack reduction, since it is directly added to the acrylate for blending, it will cause the generation of residual glue and oily substances; while Comparative Example 2 also has good peel strength before tack reduction and excellent performance of automatic shedding, and there is no residual glue, but it is not repeatable; Comparative Example 3 is the formulation after removing the water remover. Although its performance also meets the use conditions, due to the presence of moisture in the solvent and polycaprolactone itself, it is necessary to preferentially remove the moisture by heating and vacuum pumping. This step is the key to energy consumption. Also, because of the absence of the water remover, the synthesized heat-tack-reducing adhesive has a certain lack of wetting effect on the substrate, so its peel strength is smaller than that of Example 2; Examples 1, 2, 3 and 4 of the present invention introduce the polycaprolactone structure by a synthesis method, which not only achieves the purpose of having good peel strength before and after tack reduction, but also achieves the purpose of being reusable and having no residual glue before and after tack reduction. At the same time, a water remover is introduced, which greatly reduces the energy consumption required for water removal and does not produce by-products. At the same time, it also has a better wetting effect with the substrate.

[0059] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0060] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A hot viscosity-reducing adhesive, characterized in that, The raw materials for preparing the heat-removable tackifier glue, by mass parts, include the following components: 180 to 230 parts of polyacrylate; 1 to 5 parts of crosslinking agent; and 20 to 50 parts of first solvent; Among them, the raw materials for preparing the polyacrylate, by mass parts, include the following components: 60 to 80 parts of soft monomer; 10 to 30 parts of hard monomer; 1 to 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 second solvent; Among them, the two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure; Among them, the raw materials for preparing the polyacrylate monomer, by mass parts, include the following components: 1 to 5 parts of isocyanate group acrylate; 10 to 16 parts of polycaprolactone diol; 0.01 to 0.05 parts of water scavenger; 0.05 to 0.1 parts of inhibitor; and 10 to 25 parts of third solvent.

2. The hot viscosity-reducing adhesive according to claim 1, wherein The molecular weight of the polycaprolactone diol is 1000 to 2000, and the melting point of the polycaprolactone diol is below 60 degrees Celsius; The isocyanate group acrylate includes ethyl isocyanate group acrylate.

3. The hot viscosity-reducing adhesive according to claim 1, characterized in that, The water scavenger includes one or more mixtures of vinyltrimethoxysilane and vinyltriethoxysilane.

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

5. The hot-debonding adhesive according to claim 1, wherein The initiator includes one or more mixtures 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 hot viscosity-reducing adhesive according to claim 1, wherein The raw materials for preparing the heat-removable tackifier glue, by mass parts, further include 1 to 6 parts of tackifying resin and 0.1 to 0.5 parts of color powder; The tackifying resin includes one or more mixtures of terpene phenolic resin, modified phenolic resin, rosin, and petroleum resin.

7. The preparation method of the heat-debonding adhesive according to any one of claims 1 to 6, characterized in that, Including the following steps: Mix the water scavenger 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, then add isocyanate group acrylate, after fully reacting, add inhibitor, and mix evenly to obtain the polyacrylate monomer, the two end groups of the polyacrylate monomer are double bonds, and the polyacrylate monomer contains a polycaprolactone structure; Mix the polyacrylate monomer, soft monomer, hard monomer, functional monomer, initiator, and second solvent evenly, and fully react at a temperature of 60°C to 90°C to obtain polyacrylate; And Mix the polyacrylate, first solvent, and crosslinking agent evenly under the condition of not higher than 28°C to obtain the heat-removable tackifier glue.

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

9. A hot-debonding adhesive product, characterized in that, Comprising the heat-debonding adhesive according to any one of claims 1 to 6.

10. The hot-debonding adhesive product according to claim 9, wherein The heat-debonding adhesive product is a heat-debonding tape or a heat-debonding adhesive film.

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