Photosensitive polyacrylate and method for producing the same, uv-adhesive, uv-adhesive tape

Abstract

The embodiment of the application discloses a photosensitive polyacrylate and a preparation method thereof, a UV adhesion-reducing glue and a UV adhesion-reducing adhesive tape. The synthetic monomers of the photosensitive polyacrylate include soft monomers, hard monomers, functional monomers and modified monomers; the functional monomers include hydroxyl-containing acrylic monomers, and the modified monomers are selected from any one of the following formula (1) to formula (3), wherein n8 is an integer of 1 to 3, and R7 is hydrogen or methyl.

Description

Technical Field

[0001] This application relates to the field of advanced materials technology, and in particular to a photosensitive polyacrylate and its preparation method, a UV anti-adhesive adhesive, and a UV anti-adhesive tape. Background Technology

[0002] UV curing technology can alter peel strength, adhesion, and mechanical properties through chemical cross-linking, and is widely used in industries such as adhesives, coatings, and printing. Taking wafer dicing as an example, UV-cured peelable pressure-sensitive adhesives used in wafer dicing need to provide sufficient adhesion before UV curing to fix the wafer during dicing, and the peel strength needs to be significantly reduced after UV curing to avoid contamination and damage to the wafer during pick-up.

[0003] UV-cured anti-tack tape consists of a substrate and a UV-cured anti-tack layer (i.e., UV-cured peelable pressure-sensitive adhesive) on the substrate. After a short period of exposure to light, an interpenetrating polymer network structure forms inside the UV-cured anti-tack tape. This structure causes changes in the system's flowability, crosslinking density, free volume, and surface energy, resulting in reduced tack and lower peel strength.

[0004] Traditional UV-cured adhesives use non-photosensitive resins combined with photosensitive oligomers and photosensitive small molecules as the adhesive layer. After UV curing, they only form a semi-interpenetrating network structure with a low degree of cross-linking, resulting in unsatisfactory tack reduction effect. Summary of the Invention

[0005] In view of this, this application provides a polyacrylate and its preparation method, as well as a UV anti-tack tape, aiming to improve the problem that the existing UV anti-tack adhesives have unsatisfactory anti-tack effect.

[0006] In a first aspect, embodiments of this application provide a photosensitive polyacrylate, wherein the monomers for synthesizing the photosensitive polyacrylate include: soft monomers, hard monomers, functional monomers, and modified monomers;

[0007] The functional monomer includes hydroxyl-containing acrylic monomers, and the modified monomer is selected from any one of the following formulas (1) to (3).

[0008]

[0009] Where n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

[0010] In some embodiments of this application, the soft monomer: the hard monomer: the functional monomer: the modified monomer, by mass, is (45-85): (5-45): (6-12): (2-30).

[0011] In some embodiments of this application, the hydroxyl-containing acrylic monomer includes at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate; and / or

[0012] The functional monomers also include acrylic monomers that do not contain hydroxyl groups.

[0013] In some embodiments of this application, the hydroxyl-free acrylic monomer includes at least one of acrylic acid, methacrylic acid, β-acryloyloxypropionic acid, glycidyl methacrylate, and acrylamide.

[0014] In some embodiments of this application, the soft monomer includes at least one selected from isooctyl acrylate, butyl acrylate, isononyl acrylate, n-octyl methacrylate, and ethyl acrylate; and / or

[0015] The hard monomer includes at least one of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate, vinyl acetate, vinyl acetate, N-vinylpyrrole, styrene, and acrylonitrile; and / or

[0016] The raw materials for preparing the polyacrylate also include a first solvent, wherein, by mass, the ratio of the first solvent to the synthetic monomer is (40-70):(30-60); and / or

[0017] The raw materials for synthesizing the polyacrylate also include a first initiator, wherein, by mass, the ratio of the first initiator to the synthetic monomer is (0.05 to 0.5): 100.

[0018] In some embodiments of this application, the first solvent includes at least one of ethyl acetate, butyl acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, dipropylene glycol butyl ether acetate, and toluene; and / or

[0019] The first initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, diethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, sodium persulfate, and ammonium persulfate.

[0020] A second aspect of this application provides a method for preparing photosensitive polyacrylate, the method comprising:

[0021] Add some of the synthetic monomer (excluding the modified monomer) and the first solvent to the reaction vessel, and heat to 70℃~75℃ to react and obtain the first reaction solution;

[0022] Continue heating to 76°C to 80°C, add the remaining synthetic monomers (excluding the modified monomers) to the first reaction solution, and continue the reaction to obtain the second reaction solution;

[0023] The second reaction solution was cooled to 45°C to 60°C, and a polymerization inhibitor and a modified monomer were added to continue the reaction, thereby obtaining the photosensitive polyacrylate.

[0024] Among them, the synthetic monomers include: soft monomers, hard monomers, functional monomers and modified monomers;

[0025] The functional monomers include hydroxyl-containing acrylic monomers, and the modified monomers are selected from the following formula (1).

[0026] To any one of the formulas (3),

[0027]

[0028]

[0029] Where n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

[0030] A third aspect of this application provides a UV-resistant adhesive, the UV-resistant adhesive comprising the aforementioned photosensitive polyacrylate or a photosensitive polyacrylate prepared by the preparation method of the aforementioned polyacrylate.

[0031] In some embodiments of this application, the UV-resistant adhesive further includes a polyurethane oligomer, a thermosetting agent, and a photoinitiator, wherein the ratio of photosensitive polyacrylate: polyurethane oligomer: thermosetting agent: photoinitiator is 100:(5-50):(0.4-10):(0.4-5) by mass; and / or

[0032] The UV-resistant adhesive does not contain reactive diluents or reactive monomers.

[0033] In some embodiments of this application, the structure of the polyurethane oligomer is shown in formula (4).

[0034]

[0035] Wherein, n is from 1 to 10, R includes at least one of the following formulas (5) and (6); R1 includes at least one of the following formulas (7) to (10); R2 includes at least one of the following formulas (11) to (12); further, n is an integer from 1 to 3;

[0036] Where n1 is an integer from 7 to 190, and R3 is methyl or hydrogen; further, n1 is an integer from 12 to 120;

[0037] Wherein, n2 is an integer from 1 to 50, R4 includes at least one of equations (13) to (16), and R5 includes at least one of equations (17) to (21); further, n2 is an integer from 1 to 30;

[0038]

[0039] Where R6 is methyl or hydrogen, and n7 is an integer from 1 to 3;

[0040] Where n3 is an integer from 1 to 22;

[0041]

[0042] Where n4 is an integer from 1 to 24;

[0043]

[0044] Where n5 is an integer from 1 to 7;

[0045] Where n3 is an integer from 1 to 3;

[0046]

[0047] A fourth aspect of this application provides a UV anti-adhesion tape, the UV anti-adhesion tape comprising the aforementioned UV anti-adhesion adhesive.

[0048] Beneficial effects:

[0049] The modified monomer in this application contains both isocyanate functional groups (-NCO) and double bonds. It can react with the hydroxyl groups in the functional monomers via the isocyanate functional groups, thereby incorporating the modified monomer into the polyacrylate to obtain a photosensitive polyacrylate. Since the photosensitive polyacrylate in this application can be UV cured, it is beneficial for improving the tack-reducing effect of UV-cured adhesives. Detailed Implementation

[0050] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0052] In the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0053] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0054] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0055] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0056] UV curing technology can alter peel strength, adhesion, and mechanical properties through chemical cross-linking, and is widely used in industries such as adhesives, coatings, and printing. Taking wafer dicing as an example, UV-cured peelable pressure-sensitive adhesives used in wafer dicing need to provide sufficient adhesion before UV curing to fix the wafer during dicing, and the peel strength needs to be significantly reduced after UV curing to avoid contamination and damage to the wafer during pick-up.

[0057] UV-cured anti-tack tape consists of a substrate and a UV-cured anti-tack layer (i.e., UV-cured peelable pressure-sensitive adhesive) on the substrate. After a short period of exposure to light, an interpenetrating polymer network structure forms inside the UV-cured anti-tack tape. This structure causes changes in the system's flowability, crosslinking density, free volume, and surface energy, resulting in reduced tack and lower peel strength.

[0058] Traditional UV-cured adhesives use non-photosensitive resins combined with photosensitive oligomers and photosensitive small molecules as the adhesive layer. After UV curing, they only form a semi-interpenetrating network structure with a low degree of cross-linking, resulting in unsatisfactory tack reduction effect.

[0059] Therefore, embodiments of this application provide a photosensitive polyacrylate, a method for preparing the photosensitive polyacrylate, a UV anti-adhesive adhesive containing the photosensitive polyacrylate, and a UV anti-adhesive tape. The following detailed embodiments further illustrate the photosensitive polyacrylate, the method for preparing the photosensitive polyacrylate, the UV anti-adhesive adhesive containing the photosensitive polyacrylate, and the UV anti-adhesive tape of this application.

[0060] The first aspect of this application provides a photosensitive polyacrylate. It should be noted that, in this application, the photosensitive polyacrylate refers to a class of polyacrylate materials capable of undergoing polymerization reactions initiated by ultraviolet (UV) light or other light sources.

[0061] The raw materials for preparing photosensitive polyacrylate include synthetic monomers, which include: soft monomers, hard monomers, functional monomers, and modified monomers; the functional monomers include hydroxyl-containing acrylic monomers, and the modified monomers are selected from any one of the following formulas (1) to (3).

[0062]

[0063] Where n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

[0064] The modified monomer in this application contains both isocyanate functional groups (-NCO) and double bonds. It can react with the hydroxyl groups in the functional monomers via the isocyanate functional groups, thereby incorporating the modified monomer into the polyacrylate to obtain a photosensitive polyacrylate. Since the photosensitive polyacrylate in this application can be UV cured, it is beneficial for improving the tack-reducing effect of UV-cured adhesives.

[0065] For example, n8 can be 1, 2, or 3.

[0066] In some embodiments of this application, the soft monomer: the hard monomer: the functional monomer: the modified monomer, by mass parts, is (45-85): (5-45): (6-12): (2-30).

[0067] For example, the mass fraction of the soft monomer is 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, or any value between any two of the above.

[0068] For example, the mass fraction of the hard monomer is 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, or any value between any two of the above.

[0069] For example, the mass fraction of the functional unit is 6, 7, 8, 9, 10, 11, 12 parts, or any value between any two of the above.

[0070] For example, the mass fraction of the modified monomer is 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, or any two of the above values. It should be noted that if the mass fraction of the modified monomer is too low, for example, less than 2 parts, its effect on improving the tack reduction of UV-resistant adhesives is not significant; if the mass fraction of the modified monomer is too high, for example, more than 30 parts, it is easy to exceed the limit and cause raw material residue.

[0071] In some embodiments of this application, the soft monomer includes at least one of isooctyl acrylate, butyl acrylate, isononyl acrylate, n-octyl methacrylate, and ethyl acrylate.

[0072] In some embodiments of this application, the hard monomer includes at least one selected from methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate, vinyl acetate, vinyl acetate, N-vinylpyrrole, styrene, and acrylonitrile.

[0073] In some embodiments of this application, the hydroxyl-containing acrylic monomer includes at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate.

[0074] In some embodiments of this application, the functional monomer further includes at least one of acrylic acid, methacrylic acid, β-acryloyloxypropionic acid, glycidyl methacrylate, and acrylamide. It is understood that the soft monomers in the embodiments of this application typically have a lower glass transition temperature (Tg), which can improve the toughness and flexibility of the resin. Hard monomers generally have a higher glass transition temperature, increasing the hardness and heat resistance of the resin; functional monomers and modified monomers possess special chemical functional groups, used to impart specific properties to the resin, such as chemical resistance, UV stability, and adhesion. It should be noted that although the main functions of soft monomers, hard monomers, functional monomers, and modified monomers in acrylate resins differ, the combined effect of soft monomers, hard monomers, modified monomers, and functional monomers influences the overall performance of the photosensitive polyacrylate polymer. Furthermore, the selection and ratio of different soft monomers, hard monomers, modified monomers, and functional monomers result in different properties of the photosensitive polyacrylate polymer. In this application, by adding specific components and amounts of modified monomers, functional monomers, soft monomers and hard monomers to the raw materials for synthesizing photosensitive polyacrylate, the UV-resistant adhesive containing the photosensitive polyacrylate in the embodiments of this application has a better anti-tack effect after UV curing and has greater adhesive strength before UV curing.

[0075] In some embodiments of this application, the raw materials for preparing the polyacrylate further include a first solvent. Exemplarily, the ratio of the first solvent to the synthetic monomer is (40-70):(30-60) by mass. It should be noted that the synthetic monomer in this application refers to the monomer used to synthesize the photosensitive polyacrylate, that is, the sum of the mass parts of the soft monomer, hard monomer, functional monomer, and modified monomer in the raw materials.

[0076] In some embodiments of this application, the first solvent used to prepare the polyacrylate is not particularly limited. Exemplarily, the first solvent includes at least one of ethyl acetate, butyl acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, dipropylene glycol butyl ether acetate, toluene, etc.

[0077] In some embodiments of this application, the raw materials for synthesizing the polyacrylate further include a first initiator. Further, the first initiator accounts for 0.05% to 0.5% of the mass of the synthetic monomer, that is, the ratio of the first initiator to the synthetic monomer is (0.05 to 0.5): 100. Exemplarily, the first initiator accounts for 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% of the mass of the synthetic monomer, and any value between any two of the above.

[0078] It should be noted that there are no particular limitations on the first initiator in this application. For example, the first initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumene peroxide, di-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyvalerate, diethylhexyl peroxide, diisopropyl peroxide, dicyclohexyl peroxide, sodium persulfate, and ammonium persulfate.

[0079] A second aspect of this application also provides a method for preparing polyacrylate, comprising the following steps:

[0080] Step (11) introduce a protective gas into the reaction vessel.

[0081] Specifically, the reaction vessel is a reaction flask (e.g., a five-necked flask), the protective gas is nitrogen, and the venting time is 5 to 60 minutes. Of course, in some other embodiments of this application, the protective gas can also be other inert gases. The protective gas and venting time can be set according to specific circumstances and are not limited here.

[0082] Step (12) Add some of the synthetic monomers other than the modified monomers and solvent A (i.e., the first solvent) to the reaction vessel. The amount of solvent A added is 1.5 to 2.5 times the mass of the added synthetic monomers, and the temperature is raised to 70℃ to 75℃ to obtain the first reaction solution.

[0083] Specifically, 15% to 40% of synthetic monomers other than the modified monomers are added to the reaction flask. For example, 15% to 40% of soft monomers, 15% to 40% of hard monomers, and 15% to 40% of functional monomers are dissolved in solvent A as a base material and added to a five-necked flask. The stirrer is turned on and the temperature is raised to 70 to 75°C. Then, a mixture of 25% to 50% of the synthetic monomers other than the modified monomers, 0.5 to 1.5 times the mass of solvent A, and 40% to 70% of the initiator is added dropwise to the five-necked flask over a period of 1.5 to 3 hours. After the addition is complete, the reaction is maintained at this temperature for 0.5 to 1.5 hours to obtain the first reaction solution.

[0084] Step (13) Continue heating to 76°C to 80°C, add the remaining synthetic monomers other than the modified monomers to the first reaction solution, and continue the reaction to obtain the second reaction solution.

[0085] Specifically, the remaining synthetic monomers (excluding the modified monomers) and a mixture of solvent A (0.5 to 1.5 times their mass) and the remaining initiator are added dropwise over a period of 2 to 4 hours. After the addition is complete, the mixture is kept at a constant temperature for 0.5 to 1.5 hours, and then heated to 81°C to 85°C for 1.5 to 2.5 hours to obtain the second reaction solution.

[0086] Step (14) cool the second reaction solution to 45°C to 60°C, add polymerization inhibitor and modified monomer to continue the reaction, and obtain polyacrylate for later use.

[0087] Specifically, after the second reaction solution is cooled to 45°C to 60°C, 70% of the remaining solvent A and the polymerization inhibitor mixture are added dropwise and stirred for 1 hour. Then, the remaining solvent A, modified monomer, and catalyst mixture are added dropwise over a period of 0.5 to 2 hours. After the addition is complete, the reaction is maintained at the temperature for 1 to 5 hours. The remaining initiator is then added dropwise. After the addition is complete, the reaction continues for about 1.5 hours until the monomer raw materials have basically reacted completely. Then, heating is stopped to obtain polyacrylate for later use.

[0088] Specifically, the catalyst in step (14) includes at least one of dibutyltin dilaurate and stannous octoate.

[0089] Specifically, the polymerization inhibitor in step (14) includes at least one of hydroquinone and p-hydroxyanisole.

[0090] In some embodiments of this application, solvent A is not particularly limited. Exemplarily, solvent A includes at least one of ethyl acetate, butyl acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, and dipropylene glycol butyl ether acetate.

[0091] A third aspect of this application provides a UV-resistant adhesive, comprising the aforementioned photosensitive polyacrylate or a photosensitive polyacrylate prepared by the aforementioned method for preparing polyacrylate. This application improves the adhesive's tack-reducing effect by adding a photosensitive polyacrylate with a specific structure to the UV-resistant adhesive.

[0092] In some embodiments of this application, the UV-resistant adhesive further includes a polyurethane oligomer, a thermosetting agent, and a photoinitiator. Further, the ratio of photosensitive polyacrylate: polyurethane oligomer: thermosetting agent: photoinitiator by mass parts is 100:(5-50):(0.4-10):(0.4-5).

[0093] In some embodiments of this application, the UV-resistant adhesive does not include reactive diluents or reactive monomers; that is, the UV-resistant adhesive does not include photosensitive small molecules. Exemplarily, the UV-resistant adhesive is composed of the photosensitive polyacrylate, the polyurethane oligomer, the thermosetting agent, and the photoinitiator.

[0094] In some embodiments of this application, the integrated area of ​​the infrared peak of the carbon-carbon double bond in the UV-cured UV-resistant adhesive is 0%-10% of the integrated area of ​​the infrared peak of the double bond in the UV-resistant adhesive before UV curing.

[0095] A fourth aspect of this application provides a polyurethane oligomer, the structure of which is shown in formula (4).

[0096]

[0097] Wherein, n is an integer from 1 to 10, R includes at least one of the following formulas (5) and (6); R1 includes at least one of the following formulas (7) to (10); R2 includes at least one of the following formulas (11) to (12); further, n is an integer from 1 to 3;

[0098] Where n1 is an integer from 7 to 190, and R3 is methyl or hydrogen; further, n1 is an integer from 12 to 120;

[0099] Wherein, n2 is an integer from 1 to 50, R4 includes at least one of equations (13) to (16), and R5 includes at least one of equations (17) to (21); further, n2 is an integer from 1 to 30;

[0100]

[0101] Where R6 is methyl or hydrogen, and n7 is an integer from 1 to 3;

[0102] Where n3 is an integer from 1 to 22;

[0103]

[0104] Where n4 is an integer from 1 to 24;

[0105]

[0106] Where n5 is an integer from 1 to 7;

[0107] Where n6 is an integer from 1 to 3;

[0108]

[0109] Alternatively, R can be one of equations (5) and (6).

[0110] Optionally, R4 can be one to three of the equations (13) to (16).

[0111] Optionally, R5 can be one to three of the equations (17) to (21).

[0112] In some embodiments of this application, the thermosetting agent is selected from one or more of isocyanate curing agents and amine curing agents. Further, the thermosetting agent is preferably an isocyanate curing agent with ≥2 functional groups and an isocyanate value of 5% to 25%.

[0113] Specifically, the isocyanate curing agent is selected from any one or more combinations of 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethyl diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0114] Specifically, the amine curing agent is selected from any one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, and polyethylenepolyamine.

[0115] In some embodiments of this application, the photoinitiator is at least one of acetophenone, diphenylethanol ketone, benzoyl ketone, 1-hydroxy-cyclohexylbenzophenone, 2-hydroxy-2-methyl-1-phenylpropanone, benzoin dimethyl ether, etc.

[0116] This application also provides a UV-resistant adhesive, which includes the above-mentioned polyurethane oligomer or a polyurethane oligomer prepared by the above-mentioned method for preparing polyurethane oligomer.

[0117] A fifth aspect of this application provides a method for preparing a polyurethane oligomer, the method comprising:

[0118] Step (21) introduce a protective gas into the reaction vessel.

[0119] Specifically, the reaction vessel is a reaction flask (e.g., a five-necked flask), the protective gas is nitrogen, and the venting time is 5 to 60 minutes. Of course, in some other embodiments of this application, the protective gas can also be other inert gases. The protective gas and venting time can be set according to specific circumstances and are not limited here.

[0120] Step (22) involves adding diisocyanate, catalyst, and second solvent (i.e., solvent B) into a reaction vessel under a protective gas environment, followed by the addition of diol to produce a third reaction solution.

[0121] Specifically, after adding the mixture of diisocyanate, catalyst and solvent B into the reaction vessel, the temperature is raised to 45°C to 55°C, and then the diol is slowly added dropwise for 1 to 3 hours. After the addition is complete, the reaction is kept at the temperature for 1 to 3 hours.

[0122] Step (23) Continue to add hydroxyl-containing acrylate and polymerization inhibitor into the reaction vessel and continue the reaction for a period of time. Check whether the raw materials have reacted completely to obtain polyurethane oligomer.

[0123] Specifically, the diisocyanate is NCO-R1-NCO, where R1 is R1 in Formula I. The diol is HO-R-OH, where R is R in Formula I; and the hydroxyl-containing acrylate is HO-R2, where R2 is R2 in Formula I.

[0124] Specifically, a mixture of hydroxyl-containing acrylate and polymerization inhibitor is added dropwise to the reaction vessel over a period of 1 to 2 hours, and then kept at the temperature for 2 to 4 hours after the addition is complete.

[0125] Specifically, the step of detecting whether the raw materials have reacted completely includes: taking a sample of the reaction solution for infrared analysis; if no 2240 cm⁻¹ is found... -1If a peak appears nearby, the reaction is considered complete. Alternatively, the reaction solution can be titrated with -NCO value. If the titration result is ≤0.5%, the reaction is considered complete.

[0126] Specifically, the weight-average molecular weight of the diol is 500 to 8000. Further, the weight-average molecular weight of the diol is 1000 to 5000.

[0127] Specifically, the catalyst in step (22) includes at least one of dibutyltin dilaurate and stannous octoate.

[0128] Specifically, the polymerization inhibitor in step (23) includes at least one of hydroquinone and p-hydroxyanisole.

[0129] In some embodiments of this application, the solvent B is not particularly limited to at least one of ethyl acetate, butyl acetate, acetone, butanone, toluene, etc.

[0130] In some embodiments of this application, the solid content of the polyurethane oligomer prepared in step (23) is 40% to 60%, that is, the solid content of the polyurethane oligomer is 40% to 60%. It should be noted that this reaction method is also a solution polymerization reaction. The solvent, as the carrier of the reaction, has a certain influence on the polymerization activity and gel effect. When the solid content is set in the range of 40% to 60%, the polymerization reaction rate is moderate, the viscosity is moderate, and the temperature is easy to control.

[0131] The sixth aspect of this application also provides a method for preparing UV anti-adhesive tape, comprising the following steps:

[0132] Step (31) provides UV-resistant adhesive.

[0133] Specifically, photosensitive polyacrylate, polyurethane oligomer, thermosetting agent, and photoinitiator are added to a container, stirred evenly, and allowed to stand to defoam, thus obtaining a UV-resistant adhesive. The ratio of photosensitive polyacrylate: polyurethane oligomer: thermosetting agent: photoinitiator is 100:(5-50):(0.4-10):(0.4-5) by mass.

[0134] Furthermore, before allowing the adhesive to stand and defoam, solvent C can be added to the UV anti-foaming adhesive to adjust the viscosity. For example, the viscosity of the UV anti-foaming adhesive is from 300 cps to 3000 cps, preferably from 600 cps to 1500 cps. Specifically, solvent C is not particularly limited. For example, solvent C includes at least one of ethyl acetate, butyl acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, dipropylene glycol butyl ether acetate, and toluene. It should be noted that solvent A and solvent C can be the same or different, and this is not limited here.

[0135] Step (32) Apply UV anti-tack adhesive to the release film.

[0136] Specifically, the above-mentioned adhesive is evenly coated onto the release film using a coating machine. For example, the release film is PET.

[0137] Step (33) The release film coated with UV anti-tack adhesive is dried and then transferred onto the substrate film to obtain the tape.

[0138] Specifically, the release film coated with UV-resistant adhesive is placed in an oven to dry the solvent at a temperature of 60℃ to 100℃ for 1 to 3 minutes, and then transferred onto a substrate film to obtain the tape. For example, the substrate film is one of EVA, PET, PO, and PVC.

[0139] For example, the substrate layer is PVC; the release layer is PET.

[0140] Step (34) Place the above tape in an oven for curing at a temperature of 40-70°C for 24-72 hours. Once curing is complete, the UV anti-tack tape is obtained.

[0141] In some embodiments of this application, the dry thickness of the adhesive layer is 6 μm to 20 μm. Exemplarily, the dry thickness of the adhesive layer is 8 μm to 12 μm.

[0142] The UV anti-adhesion tape of this application will be further described below with reference to specific embodiments and experimental data.

[0143] Example 1

[0144] Photosensitive polyacrylate synthesis monomers: 50 parts isooctyl acrylate, 40 parts vinyl acetate, 5 parts acrylic acid, 5 parts hydroxyethyl acrylate, 7.3 parts

[0145] Solvent: 200 parts ethyl acetate.

[0146] (1) The preparation of photosensitive polyacrylate includes the following steps:

[0147] Under nitrogen protection, 30% of the synthetic monomer (excluding the modified monomer) and twice the mass of the solvent (ethyl acetate) were added to the reaction flask. The temperature was raised to 74°C, and stirring was started. 30% of the synthetic monomer (excluding the modified monomer), once the mass of the solvent, and 50% of the initiator mixture were added dropwise to the reaction flask over a period of 2 hours. After the addition was complete, the reaction was kept at the temperature for 1 hour. Then, the temperature was raised to 78°C, and the remaining synthetic monomers (excluding the modified monomers), along with a mixture of solvent and remaining initiator equal in mass, were added dropwise to the reaction flask over a period of 3 hours. After the addition was complete, the mixture was kept at this temperature for 1 hour, then the temperature was raised to 82°C and reacted for 2 hours. The temperature was then lowered to 50°C, and 70% of the remaining solvent and 0.1 part of a mixture of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomers, and 0.1 part of a mixture of dibutyltin dilaurate were added dropwise over a period of 1 hour. After the addition was complete, the mixture was kept at this temperature for 4 hours. After the reaction was complete, the mixture was cooled and discharged to obtain photosensitive polyacrylate (labeled photosensitive polyacrylate 1) for later use.

[0148] (2) The preparation of polyurethane oligomers includes the following steps:

[0149] Under nitrogen protection, diisocyanate (22.3 parts isophorone diisocyanate), 0.12 parts dibutyltin dilaurate, and 120 parts ethyl acetate were added to a reaction flask. The temperature was raised to 50°C, and then a diol (100 parts poly(1,6-hexanediol phthalate) (Mw: 2000)) was slowly added dropwise over 2 hours. After the addition was complete, the reaction was maintained at this temperature for 1 hour. Hydroxyacrylates (5.8 parts hydroxyethyl acrylate and 14.9 parts pentaerythritol triacrylate) and 0.12 parts p-hydroxyanisole were then added dropwise to the reaction flask over 1 hour. After the addition was complete, the reaction was maintained at this temperature for 3 hours. Infrared spectroscopy showed no peaks for isocyanate groups. The mixture was cooled and discharged to obtain a polyurethane oligomer (labeled as polyurethane oligomer 1).

[0150] (3) The preparation of UV anti-adhesion tape includes the following steps:

[0151] 100 parts of photosensitive polyacrylate, 100 parts of polyurethane oligomer, 2 parts of thermosetting agent (-NCO value 18%), and 2.4 parts of photoinitiator (benzoin dimethyl ether) were added to a container, stirred evenly, and allowed to stand to defoam, resulting in an adhesive solution. The adhesive solution was then evenly coated onto a release film using a coating machine. The solvent was dried in an oven at 90°C for 1.5 minutes, and then transferred to a substrate film to obtain an adhesive tape. The tape was then cured in an oven at 50°C for 70 hours until curing was complete, yielding a UV-resistant adhesive tape.

[0152] Example 2

[0153] Synthetic monomers: 20 parts isooctyl acrylate, 30 parts butyl acrylate, 40 parts methyl acrylate, 3 parts acrylic acid, 7 parts hydroxypropyl acrylate, 10.9 parts

[0154] Solvent: 170 parts ethyl acetate.

[0155] (1) The preparation of photosensitive polyacrylate includes the following steps:

[0156] Under nitrogen protection, 20% of the synthetic monomer (excluding the modified monomer) and 1.5 times its mass of solvent (ethyl acetate) were added to the reaction flask. The temperature was raised to 72°C, and stirring was started. 50% of the synthetic monomer (excluding the modified monomer), 1.5 times its mass of solvent, and 50% of the initiator mixture were added dropwise to the reaction flask over a period of 1.5 hours. After the addition was complete, the reaction was kept at this temperature for 1.5 hours. Then, the temperature was raised to 76°C, and the remaining synthetic monomers (excluding the modified monomers), along with 0.8 times their mass of solvent and the remaining initiator mixture, were added dropwise to the reaction flask over a period of 2.5 hours. After the addition was complete, the mixture was kept at this temperature for 0.6 hours, then the temperature was raised to 81°C and the mixture was reacted for 1.5 hours. The temperature was then lowered to 45°C, and 70% of the remaining solvent and 0.15 parts of a mixture of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomers, and 0.15 parts of a mixture of dibutyltin dilaurate were added dropwise over a period of 0.8 hours. After the addition was complete, the mixture was kept at this temperature for 5 hours. After the reaction was complete, the mixture was cooled and discharged to obtain photosensitive polyacrylate (labeled photosensitive polyacrylate 2) for later use.

[0157] (2) The preparation of polyurethane oligomers includes the following steps:

[0158] Under nitrogen protection, diisocyanate (34.8 parts toluene-2,4-diisocyanate), 0.12 parts dioctylstannous, and 260 parts acetone were added to a reaction flask. The temperature was raised to 45°C, and then a diol (100 parts poly(1,4-butylene adipate) (Mw: 1000)) was slowly added dropwise over 3 hours. After the addition was complete, the reaction was maintained at this temperature for 2 hours. Hydroxyacrylates (15.6 parts hydroxypropyl acrylate and 23.8 parts pentaerythritol triacrylate) and 0.12 parts p-hydroxyanisole were then added dropwise to the reaction flask over 1.5 hours. After the addition was complete, the reaction was maintained at this temperature for 4 hours. Infrared spectroscopy showed no peaks for isocyanate groups. The mixture was cooled and discharged to obtain a polyurethane oligomer (labeled polyurethane oligomer 2).

[0159] (3) The preparation of UV anti-adhesion tape includes the following steps:

[0160] 100 parts of photosensitive polyacrylate, 20 parts of polyurethane oligomer, 1.5 parts of thermosetting agent (-NCO value 20%), and 1.8 parts of photoinitiator (1-hydroxy-cyclohexylbenzophenone) were added to a container, stirred evenly, and allowed to stand to defoam, resulting in an adhesive solution. The adhesive solution was then evenly coated onto a release film using a coating machine. The solvent was dried in an oven at 80°C for 2 minutes, and then transferred to a substrate film to obtain an adhesive tape. The tape was then cured in an oven at 60°C for 60 hours, resulting in a UV-resistant adhesive tape.

[0161] Example 3

[0162] Synthetic monomers: 60 parts butyl acrylate, 30 parts ethyl methacrylate, 2 parts styrene, 2 parts methacrylic acid, 6 parts hydroxyethyl acrylate, 5.1 parts

[0163] Solvent: 172 parts toluene.

[0164] (1) The preparation of photosensitive polyacrylate includes the following steps:

[0165] Under nitrogen protection, 33% of the synthetic monomer (excluding the modified monomer) and twice the mass of the solvent (toluene) were added to the reaction flask. The temperature was raised to 75°C, and stirring was started. 33% of the synthetic monomer (excluding the modified monomer), once the mass of the solvent, and 50% of the initiator mixture were added dropwise to the reaction flask over a period of 2 hours. After the addition was complete, the reaction was kept at the temperature for 1 hour. Then, the temperature was raised to 79°C, and the remaining synthetic monomers (excluding the modified monomers), along with a mixture of solvent and remaining initiator equal in mass, were added dropwise to the reaction flask over a period of 3 hours. After the addition was complete, the mixture was kept at this temperature for 1 hour, then the temperature was raised to 83°C and the reaction was continued for 2 hours. The temperature was then lowered to 50°C, and 70% of the remaining solvent and 0.2 parts of hydroquinone mixture were added and stirred for 1 hour. The final remaining solvent, modified monomers, and 0.2 parts of dibutyltin dilaurate mixture were added dropwise over a period of 1 hour. After the addition was complete, the mixture was kept at this temperature for 4 hours. After the reaction was complete, the temperature was lowered and the product was discharged to obtain photosensitive polyacrylate (labeled photosensitive polyacrylate 3) for later use.

[0166] (2) The preparation of polyurethane oligomers includes the following steps:

[0167] Under nitrogen protection, diisocyanate (11.1 parts isophorone diisocyanate), 0.12 parts dibutyltin dilaurate, and 80 parts ethyl acetate were added to a reaction flask. The temperature was raised to 50°C, and then a diol (100 parts polypentyl glycol adipate diol (Mw: 4000)) was slowly added dropwise over 2 hours. After the addition was complete, the reaction was maintained at this temperature for 1 hour. Hydroxyacrylates (3.6 parts hydroxybutyl acrylate and 7.4 parts pentaerythritol triacrylate) and 0.12 parts hydroquinone were then added dropwise to the reaction flask over 1 hour. After the addition was complete, the reaction was maintained at this temperature for 3 hours. Infrared spectroscopy showed no peaks for isocyanate groups. The mixture was cooled and discharged to obtain a polyurethane oligomer (labeled polyurethane oligomer 3) for later use.

[0168] (3) The preparation of UV anti-adhesion tape includes the following steps:

[0169] 100 parts of photosensitive polyacrylate, 12 parts of polyurethane oligomer, 7 parts of thermosetting agent (-NCO value 6%), and 1 part of photoinitiator (2-hydroxy-2-methyl-1-phenylpropanone) were added to a container, stirred evenly, and allowed to stand to defoam, resulting in an adhesive solution. The adhesive solution was then evenly coated onto a release film using a coating machine. The solvent was dried in an oven at 90°C for 1.5 minutes, and then transferred to a substrate film to obtain an adhesive tape. The tape was then cured in an oven at 50°C for 72 hours until curing was complete, yielding a UV-resistant adhesive tape.

[0170] Example 4

[0171] Synthetic monomers: 20 parts isooctyl acrylate, 35 parts ethyl acrylate, 30 parts butyl acrylate, 5 parts ethyl methacrylate, 2 parts acrylic acid, 8 parts hydroxyethyl methacrylate, 12.8 parts

[0172]

[0173] Solvent: 150 parts ethyl acetate.

[0174] (1) The preparation of photosensitive polyacrylate includes the following steps:

[0175] Under nitrogen protection, 40% of the synthetic monomer (excluding the modified monomer) and 2.5 times its mass of solvent (ethyl acetate) were added to the reaction flask. The temperature was raised to 74°C, and stirring was started. 25% of the synthetic monomer (excluding the modified monomer), 0.5 times its mass of solvent, and 50% of the initiator mixture were added dropwise to the reaction flask over a period of 3 hours. After the addition was complete, the reaction was kept at this temperature for 0.6 hours. The temperature was raised to 78°C, and the remaining synthetic monomers (excluding the modified monomers), along with 0.5 times their mass of solvent and the remaining initiator mixture, were added dropwise to the reaction flask over a period of 2 hours. After the addition was complete, the reaction was maintained at this temperature for 1.5 hours. The temperature was then raised to 82°C and reacted for another 2.5 hours. The temperature was lowered to 55°C, and 70% of the remaining solvent and 0.25 parts of a mixture of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomers, and 0.15 parts of a mixture of dibutyltin dilaurate were added dropwise over a period of 1 hour. After the addition was complete, the reaction was maintained at this temperature for 4 hours. After the reaction was complete, the temperature was lowered and the product was discharged to obtain photosensitive polyacrylate (numbered photosensitive polyacrylate 4) for later use.

[0176] (2) The preparation of polyurethane oligomers includes the following steps:

[0177] Under nitrogen protection, diisocyanate (87.45 parts of 4,4-diisocyanate dicyclohexylmethane), 0.12 parts of dibutyltin dilaurate, and 120 parts of ethyl acetate were added to a reaction flask. The temperature was raised to 50°C, and then a diol (100 parts of polypropylene glycol (Mw: 600)) was slowly added dropwise over 2 hours. After the addition was complete, the reaction was maintained at this temperature for 1 hour. Hydroxyacrylate (38.7 parts of hydroxyethyl acrylate) and 0.13 parts of p-hydroxyanisole were then added dropwise to the reaction flask over 2 hours. After the addition was complete, the reaction was maintained at this temperature for 2.5 hours. Infrared spectroscopy showed no peaks for isocyanate groups. The mixture was cooled and discharged to obtain a polyurethane oligomer (labeled polyurethane oligomer 4) for later use.

[0178] (3) The preparation of UV anti-adhesion tape includes the following steps:

[0179] 100 parts of photosensitive polyacrylate, 35 parts of polyurethane oligomer, 0.8 parts of thermosetting agent (-NCO value 15%), and 3 parts of photoinitiator (benzoin dimethyl ether) were added to a container, stirred evenly, and allowed to stand to defoam, resulting in an adhesive solution. The adhesive solution was then evenly coated onto a release film using a coating machine. The solvent was dried in an oven at 100°C for 1.2 minutes, and then transferred to a substrate film to obtain an adhesive tape. The tape was then cured in an oven at 40°C for 72 hours until curing was complete, yielding a UV-resistant adhesive tape.

[0180] Example 5

[0181] Synthetic monomers: 50 parts isooctyl acrylate, 40 parts vinyl acetate, 5 parts acrylic acid, 5 parts hydroxyethyl acrylate, 7.3 parts

[0182] Solvent: 200 parts ethyl acetate.

[0183] (1) The preparation of photosensitive polyacrylate includes the following steps:

[0184] Under nitrogen protection, 30% of the synthetic monomer (excluding the modified monomer) and twice the mass of the solvent (ethyl acetate) were added to the reaction flask. The temperature was raised to 74°C, and stirring was started. 30% of the synthetic monomer (excluding the modified monomer), once the mass of the solvent, and 50% of the initiator mixture were added dropwise to the reaction flask over a period of 2 hours. After the addition was complete, the reaction was kept at the temperature for 1 hour. The temperature was raised to 78°C, and the remaining synthetic monomers (excluding the modified monomers), along with a mixture of solvent and remaining initiator of equal mass, were added dropwise to the reaction flask over a period of 3 hours. After the addition was complete, the reaction was maintained at this temperature for 1 hour, then the temperature was raised to 82°C and the reaction was maintained for 2 hours. The temperature was then lowered to 50°C, and 70% of the remaining solvent and 0.1 part of a mixture of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomers, and 0.1 part of a mixture of dibutyltin dilaurate were added dropwise over a period of 1 hour. After the addition was complete, the reaction was maintained at this temperature for 4 hours. After the reaction was complete, the temperature was lowered and the product was discharged to obtain photosensitive polyacrylate (labeled photosensitive polyacrylate 1) for later use.

[0185] (2) The preparation of polyurethane oligomers includes the following steps:

[0186] Under nitrogen protection, diisocyanate (22.3 parts isophorone diisocyanate), 0.12 parts dibutyltin dilaurate, and 120 parts ethyl acetate were added to a reaction flask. The temperature was raised to 50°C, and then a diol (100 parts poly(1,6-hexanediol phthalate) (Mw: 2000)) was slowly added dropwise over 2 hours. After the addition was complete, the reaction was maintained at this temperature for 1 hour. Hydroxyacrylates (5.8 parts hydroxyethyl acrylate and 14.9 parts pentaerythritol triacrylate) and 0.12 parts p-hydroxyanisole were then added dropwise to the reaction flask over 1 hour. After the addition was complete, the reaction was maintained at this temperature for 3 hours. Infrared spectroscopy showed no peaks for isocyanate groups. The mixture was cooled and discharged to obtain a polyurethane oligomer (labeled as polyurethane oligomer 1).

[0187] (3) The preparation of UV anti-adhesion tape includes the following steps:

[0188] 100 parts of photosensitive polyacrylate, 1.4 parts of polyurethane oligomer, 13 parts of pentaerythritol triacrylate, 13 parts of trimethylolpropane triacrylate, 2 parts of thermosetting agent (-NCO value 18%), and 2.4 parts of photoinitiator (benzoin dimethyl ether) were added to a container, stirred evenly, and allowed to stand to defoam, resulting in an adhesive solution. The adhesive solution was then evenly coated onto a release film using a coating machine. The solvent was dried in an oven at 90°C for 1.5 minutes, and then transferred to a substrate film to obtain an adhesive tape. The tape was then cured in an oven at 50°C for 70 hours until curing was complete, yielding a UV-resistant adhesive tape.

[0189] The difference between Example 5 and Example 1 is that, in the preparation of UV anti-adhesion tape, photosensitive small molecules are used to replace most of the polyurethane oligomers.

[0190] Comparative Example 1

[0191] The difference between Comparative Example 1 and Example 1 is that no modified monomer was used in the preparation of photosensitive polyacrylate in Comparative Example 1.

[0192] Comparative Example 2

[0193] The difference between Comparative Example 2 and Example 2 is that no modified monomer was used in the preparation of photosensitive polyacrylate in Comparative Example 2.

[0194] Comparative Example 3

[0195] The difference between Comparative Example 3 and Example 3 is that no modified monomer was used in the preparation of photosensitive polyacrylate in Comparative Example 3.

[0196] Comparative Example 4

[0197] The difference between Comparative Example 4 and Example 4 is that no modified monomer was used in the preparation of photosensitive polyacrylate in Comparative Example 4.

[0198] Performance testing

[0199] The following performance tests were conducted on the UV anti-tack tapes used in the above embodiments and comparative examples:

[0200] Peel force: The peel force was tested at 180° according to GB / T 2792-2014. The sample size was 25mm×300mm.

[0201] UV curing rate: The UV curing rate is calculated by measuring the integral area of ​​the carbon-carbon double bond infrared peaks in the adhesive layer before and after UV curing. UV curing rate = (before UV curing - after UV curing) / before UV curing × 100%.

[0202] Residual adhesive: Use a microscope to observe whether there is any residual adhesive on the picked-up chip.

[0203] Cleavage test: Cut three wafers and observe under a microscope that the surface damage size of all chips is <30×5μm and the vertical damage size is <15μm, then it is considered qualified.

[0204] Pickup capability: If all chips can be successfully picked up without damage or flying material when cutting three wafers, it is considered qualified.

[0205] The UV-resistant adhesive tapes prepared in each experimental example were tested, and the test results are shown in Table 1:

[0206] Table 1

[0207]

[0208]

[0209] As can be seen from Examples 1 to 5, Comparative Examples 1 to 4 and Table 1, adding modified monomers to the reaction raw materials of polyacrylate can make the prepared UV anti-adhesion tape have greater peel force before UV irradiation and lower peel force after UV irradiation, thus having a better anti-adhesion effect.

[0210] The test results of Example 5 show that its tack reduction effect is improved compared to Comparative Example 1. However, a comparison between Example 1 and Example 5 shows that using photosensitive small molecules to replace polyurethane oligomers in UV tack reduction tape leads to a decrease in the UV pre-peel force of the UV tack reduction adhesive, a worse tack reduction effect, and the presence of adhesive residue. Furthermore, its cutability and pick-up performance are also unsatisfactory. In addition, after UV irradiation, the cross-linking degree of the entire adhesive layer increases significantly, and unreacted photosensitive small molecules are easily released in the adhesive layer, making them difficult to react, resulting in a lower UV curing rate compared to other experimental examples.

[0211] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A photosensitive polyacrylate, characterized in that, The raw materials for preparing the photosensitive polyacrylate include synthetic monomers, which include: soft monomers, hard monomers, functional monomers, and modified monomers. The functional monomers include hydroxyl-containing acrylic monomers, and the modified monomers are selected from the compounds shown in formula (3); Equation (3); By mass, the soft monomer: the hard monomer: the functional monomer: the modified monomer is (45-85): (5-45): (6-12): (2-30); The preparation method of the photosensitive polyacrylate includes: adding a portion of the synthetic monomer other than the modified monomer and the first solvent into the reaction vessel, and heating to 70℃~75℃ to react and obtain the first reaction solution; Continue heating to 76°C to 80°C, add the remaining synthetic monomers (excluding the modified monomers) to the first reaction solution, and continue the reaction to obtain the second reaction solution; The second reaction solution is cooled to 45°C to 60°C, and a polymerization inhibitor and a modified monomer are added to continue the reaction, thereby obtaining the photosensitive polyacrylate.

2. The photosensitive polyacrylate as described in claim 1, characterized in that, The hydroxyl-containing acrylic monomers include at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate; and / or The functional monomers also include hydroxyl-free acrylic monomers or acrylamides.

3. The photosensitive polyacrylate as described in claim 2, characterized in that, The hydroxyl-free acrylic monomers include at least one of acrylic acid, methacrylic acid, β-acryloyloxypropionic acid, and glycidyl methacrylate.

4. The photosensitive polyacrylate according to any one of claims 1 to 3, characterized in that, The soft monomer includes at least one of isooctyl acrylate, butyl acrylate, isononyl acrylate, n-octyl methacrylate, and ethyl acrylate; and / or The hard monomer includes at least one of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate, vinyl acetate, N-vinylpyrrole, styrene, and acrylonitrile; and / or The raw materials for preparing the polyacrylate also include a first solvent, wherein, by mass, the first solvent: the synthetic monomer is (40-70): (30-60); and / or The raw materials for synthesizing the polyacrylate also include a first initiator, wherein, by mass, the ratio of the first initiator to the synthetic monomer is (0.05 to 0.5):

100.

5. The photosensitive polyacrylate as described in claim 4, characterized in that, The first solvent comprises at least one of ethyl acetate, butyl acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, dipropylene glycol butyl ether acetate, and toluene; and / or The first initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxide, tert-butyl peroxybenzoate, diethylhexyl peroxide, diisopropyl peroxide, dicyclohexyl peroxide, sodium persulfate, and ammonium persulfate.

6. A method for preparing photosensitive polyacrylate, characterized in that, The preparation method includes: Add some of the synthetic monomer (excluding the modified monomer) and the first solvent to the reaction vessel, and heat to 70℃~75℃ to react and obtain the first reaction solution; Continue heating to 76°C to 80°C, add the remaining synthetic monomers (excluding the modified monomers) to the first reaction solution, and continue the reaction to obtain the second reaction solution; The second reaction solution was cooled to 45°C to 60°C, and a polymerization inhibitor and a modified monomer were added to continue the reaction, thereby obtaining the photosensitive polyacrylate. The synthetic monomers include: soft monomers, hard monomers, functional monomers and modified monomers; by mass, the ratio of the soft monomer: the hard monomer: the functional monomer: the modified monomer is (45-85): (5-45): (6-12): (2-30). The functional monomers include hydroxyl-containing acrylic monomers, and the modified monomers are selected from the compounds shown in formula (3); Equation (3).

7. A UV-resistant adhesive, characterized in that, The UV-resistant adhesive includes the photosensitive polyacrylate as described in any one of claims 1 to 5 or the photosensitive polyacrylate prepared by the method for preparing the polyacrylate as described in claim 6.

8. The UV anti-tack adhesive as described in claim 7, characterized in that, The UV-resistant adhesive further includes polyurethane oligomers, thermosetting agents, and photoinitiators. The photosensitive polyacrylate:polyurethane oligomer:thermosetting agent:photoinitiator ratio, calculated by mass parts, is 100:(5-50):(0.4-10):(0.4-5); and / or The UV-resistant adhesive does not contain reactive diluents or reactive monomers.

9. The UV anti-tack adhesive as described in claim 7, characterized in that, The UV-resistant adhesive also includes a polyurethane oligomer, the structure of which is shown in formula (4). Equation (4), Where n is an integer from 1 to 10, R includes at least one of the following equations (5) and (6); R1 includes at least one of the following equations (7) to (10); R2 includes at least one of the following equations (11) to (12); Equation (5); where n1 is an integer from 7 to 190, and R3 is methyl or hydrogen; Equation (6); where n2 is an integer from 1 to 50, R4 includes at least one of Equations (13) to (16), and R5 includes at least one of Equations (17) to (21); Equation (7); Equation (8); Equation (9); Equation (10); Equation (11); Equation (12); where R6 is methyl or hydrogen, and n7 is an integer from 1 to 3; Equation (13); where n3 is an integer from 1 to 22; Equation 14; Formula 15; Formula 16; Equation 17; where n4 is an integer from 1 to 24; Formula 18; Equation 19; where n5 is an integer from 1 to 7; Equation 20; where n6 is an integer from 1 to 3; Equation 21.

10. The UV anti-tack adhesive as described in claim 9, characterized in that, The n is an integer from 1 to 3.

11. The UV anti-tack adhesive as described in claim 9, characterized in that, The n1 is an integer from 12 to 120.

12. The UV anti-tack adhesive as described in claim 9, characterized in that, n2 is an integer from 1 to 30.

13. A UV-resistant adhesive tape, characterized in that, The UV anti-adhesion tape includes the UV anti-adhesion adhesive as described in any one of claims 7 to 12.

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