Photosensitive polyacrylate and preparation method thereof, UV viscosity-reducing adhesive and UV viscosity-reducing adhesive tape

Abstract

The embodiment of the invention discloses photosensitive polyacrylate and a preparation method thereof, a UV viscosity-reducing adhesive and a UV viscosity-reducing adhesive tape. Synthetic monomers of the photosensitive polyacrylate comprise a soft monomer, a hard monomer, a functional monomer and a modified monomer, the functional monomer comprises a hydroxyl-containing acrylic monomer, the modified monomer is selected from any one of the following formulas (1) to (3): # imgabs0 #, n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

Description

Technical Field

[0001] The present application relates to the field of advanced material technology, and in particular to a photosensitive polyacrylate and a preparation method thereof, a UV anti-viscosity adhesive, and a UV anti-viscosity tape. Background Art

[0002] UV curing technology can change its peel strength, viscosity and mechanical properties through chemical cross-linking, and is widely used in adhesives, coatings, printing and other industries. Taking the field of wafer cutting as an example, the UV-curable peelable pressure-sensitive adhesive used in the field of wafer cutting needs to provide sufficient adhesion before UV light curing to fix the wafer during the cutting process, and the peel strength needs to be greatly reduced after UV light curing to avoid contamination and damage to the wafer during the picking process.

[0003] UV anti-viscosity tape includes a substrate and a UV anti-viscosity adhesive layer (i.e., UV curable peelable pressure-sensitive adhesive) on the substrate. After a short period of light exposure, an interpenetrating polymer network structure is formed inside the UV anti-viscosity adhesive. This structure changes the fluidity, cross-linking density, free volume, and surface energy of the system, thereby reducing the viscosity and peel strength of the tape.

[0004] Traditional UV viscosity-reducing adhesives use non-photosensitive resins combined with photosensitive oligomers and photosensitive small molecules as the adhesive layer. After UV curing, only a semi-interpenetrating network structure with a low degree of cross-linking is formed, resulting in an unsatisfactory viscosity-reducing effect. Summary of the invention

[0005] In view of this, the present application provides a polyacrylate and a preparation method thereof, and a UV anti-viscosity tape, aiming to improve the problem that the existing UV anti-viscosity adhesive has an unsatisfactory anti-viscosity effect.

[0006] In a first aspect, an embodiment of the present application provides a photosensitive polyacrylate, wherein the synthetic monomers of the photosensitive polyacrylate include: a soft monomer, a hard monomer, a functional monomer, and a modified monomer;

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

[0008]

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

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

[0011] In some embodiments of the present 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 not containing hydroxyl groups.

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

[0014] In some embodiments of the present application, the soft monomer includes at least one of 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-vinyl pyrrole, styrene, and acrylonitrile; and / or

[0016] The raw material for preparing the polyacrylate further comprises a first solvent, wherein the first solvent: the synthetic monomer is (40-70): (30-60) by mass; and / or

[0017] The synthetic raw material of the polyacrylate also includes a first initiator. By mass, the ratio of the first initiator to the synthetic monomer is (0.05 to 0.5):100.

[0018] In some embodiments of the present 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, azobisisoheptylnitrile, dibenzoyl peroxide, dodecyl peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, tert-butyl perbenzoate, tert-butyl pervalerate, diethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, sodium persulfate, and ammonium persulfate.

[0020] The second aspect of the present application provides a method for preparing a photosensitive polyacrylate, the preparation method comprising:

[0021] Adding part of the synthetic monomers except the modified monomer and the first solvent into the reaction container, raising the temperature to 70° C. to 75° C. to react and obtain a first reaction liquid;

[0022] Continue to raise the temperature to 76° C. to 80° C., add the remaining synthetic monomers except the modified monomers to the first reaction liquid, and continue to react to obtain a second reaction liquid;

[0023] The second reaction liquid is cooled to 45° C. to 60° C., and a polymerization inhibitor and a modified monomer are added to continue the reaction to obtain the photosensitive polyacrylate;

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

[0025] The functional monomer includes a hydroxyl-containing acrylic monomer, and the modified monomer is selected from the following formula (1):

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

[0027]

[0028]

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

[0030] The third aspect of the present application provides a UV viscosity-reducing adhesive, wherein the UV viscosity-reducing adhesive comprises the photosensitive polyacrylate or the photosensitive polyacrylate prepared by the polyacrylate preparation method.

[0031] In some embodiments of the present application, the UV viscosity-reducing adhesive further comprises a polyurethane oligomer, a thermal curing agent and a photoinitiator, and the ratio of the photosensitive polyacrylate: polyurethane oligomer: thermal curing agent: photoinitiator is 100: (5-50): (0.4-10): (0.4-5) by weight; and / or

[0032] The UV viscosity-reducing adhesive does not include reactive diluents or reactive monomers.

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

[0034]

[0035] Wherein, n is 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] wherein 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 formula (13) to formula (16), and R5 includes at least one of formula (17) to formula (21); further, n2 is an integer from 1 to 30;

[0038]

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

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

[0041]

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

[0043]

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

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

[0046]

[0047] A fourth aspect of the present application provides a UV anti-viscosity tape, wherein the UV anti-viscosity tape comprises the UV anti-viscosity adhesive.

[0048] Beneficial effects:

[0049] The modified monomer in the embodiment of the present application contains both an isocyanate functional group (-NCO) and a double bond, and can react with the hydroxyl group in the functional monomer through the isocyanate functional group, so that the modified monomer is connected to the polyacrylate to obtain a photosensitive polyacrylate. Since the photosensitive polyacrylate in the present application can be UV cured, it is beneficial to improve the viscosity reduction effect of the UV viscosity-reducing adhesive. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention 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 related listed items.

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

[0053] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0054] In the present application, "at least one" means one or more, and "plurality" 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 items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0055] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have 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., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0056] UV curing technology can change peel strength, viscosity and mechanical properties through chemical cross-linking, and is widely used in adhesives, coatings, printing and other industries. Taking the field of wafer cutting as an example, the UV-curable peelable pressure-sensitive adhesive used in the field of wafer cutting needs to provide sufficient adhesion before UV light curing to fix the wafer during the cutting process, and the peel strength needs to be greatly reduced after UV light curing to avoid contamination and damage to the wafer during the picking process.

[0057] UV anti-viscosity tape includes a substrate and a UV anti-viscosity adhesive layer (i.e., UV curable peelable pressure-sensitive adhesive) on the substrate. After a short period of light exposure, an interpenetrating polymer network structure is formed inside the UV anti-viscosity adhesive. This structure changes the fluidity, cross-linking density, free volume, and surface energy of the system, thereby reducing the viscosity and peel strength of the tape.

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

[0059] In view of this, the embodiments of the present application provide a photosensitive polyacrylate, a method for preparing the photosensitive polyacrylate, a UV viscosity-reducing adhesive having the photosensitive polyacrylate, and a UV viscosity-reducing tape. The photosensitive polyacrylate, the method for preparing the photosensitive polyacrylate, the UV viscosity-reducing adhesive having the photosensitive polyacrylate, and the UV viscosity-reducing tape in the present application are further described below in conjunction with specific embodiments.

[0060] In a first aspect, the embodiment of the present application provides a photosensitive polyacrylate. It should be noted that the photosensitive polyacrylate in the present application refers to a type of polyacrylate material that can be polymerized by ultraviolet light (UV) or other light sources.

[0061] 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 any one of the following formulas (1) to (3):

[0062]

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

[0064] The modified monomer in the embodiment of the present application contains both an isocyanate functional group (-NCO) and a double bond, and can react with the hydroxyl group in the functional monomer through the isocyanate functional group, so that the modified monomer is connected to the polyacrylate to obtain a photosensitive polyacrylate. Since the photosensitive polyacrylate in the present application can be UV cured, it is beneficial to improve the viscosity reduction effect of the UV viscosity-reducing adhesive.

[0065] Exemplarily, n8 is 1, or 2, or 3.

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

[0067] Exemplarily, the mass fractions of the soft monomer are 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, and values ​​between any two of the above values.

[0068] Exemplarily, 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, and values ​​between any two of the above values.

[0069] Exemplarily, the mass fraction of the functional monomer is 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, and a value between any two of the above values.

[0070] Exemplarily, 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 and values ​​between 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, it has no significant effect on improving the viscosity reduction of the UV viscosity-reducing adhesive; if the mass fraction of the modified monomer is too high, for example, more than 30 parts, it is easy to cause excessive raw material residues.

[0071] In some embodiments of the present 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 the present application, the hard monomer includes at least one of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate, vinyl acetate, vinyl acetate, N-vinyl pyrrole, styrene, and acrylonitrile.

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

[0074] In some embodiments of the present application, the functional monomer also includes at least one of acrylic acid, methacrylic acid, β-acryloxypropionic acid, glycidyl methacrylate, and acrylamide. It is understandable that the soft monomer in the embodiments of the present application usually has 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, which increases the hardness and heat resistance of the resin; functional monomers and modified monomers carry special chemical functional groups, which are used to give the resin specific properties, such as chemical resistance, UV stability, adhesion, etc. It should be noted that although the main functions of the soft monomer, hard monomer, functional monomer and modified monomer in the acrylic resin are different, the joint action of the soft monomer, hard monomer, modified monomer and functional monomer affects the performance of the entire photosensitive polyacrylate, and the selection and ratio of different soft monomers, hard monomers, modified monomers and functional monomers make the performance of the photosensitive polyacrylate polymer different. In the present application, by adding modified monomers, functional monomers, soft monomers and hard monomers of specific components and contents into the raw materials for synthesizing photosensitive polyacrylate, the UV viscosity-reducing adhesive having the photosensitive polyacrylate in the embodiment of the present application has a better viscosity-reducing effect after UV curing and has a greater adhesion before UV curing.

[0075] In some embodiments of the present application, the raw material for preparing the polyacrylate further includes a first solvent. Exemplarily, by weight, the first solvent: the synthetic monomer is (40-70): (30-60). It should be noted that the synthetic monomer in the present application refers to the monomer for synthesizing the photosensitive polyacrylate, that is, the sum of the weight fractions of the soft monomer, hard monomer, functional monomer and modified monomer in the raw material.

[0076] In some embodiments of the present application, there is no particular limitation on the first solvent used to prepare the polyacrylate. For example, 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 the present application, the synthetic raw material of the polyacrylate further includes a first initiator. Further, the first initiator accounts for 0.05% to 0.5% of the mass of the synthetic monomer, that is, the first initiator: 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 a value between any two of the above values.

[0078] It should be noted that the first initiator in the present application is not particularly limited. Exemplarily, the first initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptylnitrile, dibenzoyl peroxide, dodecyl peroxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, tert-butyl perbenzoate, tert-butyl pervalerate, diethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, sodium persulfate, ammonium persulfate, and the like.

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

[0080] Step (11) introducing protective gas into the reaction container.

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

[0082] Step (12) Add part of the synthetic monomers except the modified monomers and solvent A (i.e., the first solvent) into the reaction container, wherein the amount of solvent A added is 1.5 to 2.5 times the mass of the synthetic monomers added, and heat the reaction to 70° C. to 75° C. to obtain a first reaction solution.

[0083] Specifically, 15% to 40% of synthetic monomers other than the modified monomers are added to the reaction bottle. For example, 15% to 40% of soft monomers, 15% to 40% of hard monomers, and 15% to 40% of functional monomers are added to the reaction bottle and dissolved in solvent A as a base material, and then added to a five-necked flask, and the agitator is turned on and the temperature is increased. After the temperature is increased to 70 to 75° C., a mixture of 25% to 50% of 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, and the addition time is 1.5 hours to 3 hours. After the addition is completed, the mixture is kept warm for reaction for 0.5 hours to 1.5 hours to obtain the first reaction solution.

[0084] Step (13) continues to heat up to 76° C. to 80° C., adds the remaining synthetic monomers except the modified monomers to the first reaction liquid, and continues the reaction to obtain a second reaction liquid.

[0085] Specifically, the remaining synthetic monomers except the modified monomers and a mixture of 0.5 to 1.5 times their mass of solvent A and the remaining initiator are added dropwise for 2 to 4 hours. After the addition is completed, the mixture is kept warm for reaction for 0.5 to 1.5 hours, and then the temperature is raised to 81° C. to 85° C. for reaction for 1.5 to 2.5 hours to obtain the second reaction liquid.

[0086] Step (14) The second reaction liquid is cooled to 45° C. to 60° C., and a polymerization inhibitor and a modified monomer are added to continue the reaction to obtain a polyacrylate for standby use.

[0087] Specifically, after the second reaction liquid is cooled to 45°C to 60°C, 70% of the remaining solvent A and the inhibitor mixture are added dropwise and stirred for 1 hour, and then the remaining solvent A, modified monomer, and catalyst mixture are continued to be added dropwise for 0.5 to 2 hours. After the addition is completed, the reaction is kept warm for 1 to 5 hours, and the remaining initiator is added dropwise. After the addition is completed, the reaction is continued for about 1.5 hours. The monomer raw materials are basically reacted, and then the heating is stopped to obtain the polyacrylate for use.

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

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

[0090] In some embodiments of the present application, the solvent A is not particularly limited. For example, the 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] The third aspect of the embodiment of the present application provides a UV viscosity-reducing adhesive, which includes the above-mentioned photosensitive polyacrylate or the photosensitive polyacrylate prepared by the above-mentioned polyacrylate preparation method. The present application is beneficial to improving the viscosity-reducing effect of the UV viscosity-reducing adhesive by adding a photosensitive polyacrylate with a specific structure to the UV viscosity-reducing adhesive.

[0092] In some embodiments of the present application, the UV viscosity-reducing adhesive further comprises a polyurethane oligomer, a thermal curing agent and a photoinitiator. Further, calculated by weight, the photosensitive polyacrylate: polyurethane oligomer: thermal curing agent: photoinitiator is 100: (5-50): (0.4-10): (0.4-5).

[0093] In some embodiments of the present application, the UV viscosity-reducing adhesive does not include a reactive diluent or a reactive monomer, that is, the UV viscosity-reducing adhesive does not include a photosensitive small molecule. Exemplarily, the UV viscosity-reducing adhesive is composed of the photosensitive polyacrylate, the polyurethane oligomer, the thermal curing agent, and the photoinitiator.

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

[0095] A fourth aspect of the present application provides a polyurethane oligomer, the structure of which is shown in the following 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] wherein 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 formula (13) to formula (16), and R5 includes at least one of formula (17) to formula (21); further, n2 is an integer from 1 to 30;

[0100]

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

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

[0103]

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

[0105]

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

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

[0108]

[0109] Optionally, R is one of formula (5) and formula (6).

[0110] Optionally, R4 is 1 to 3 of formula (13) to formula (16).

[0111] Optionally, R5 is 1 to 3 of formula (17) to formula (21).

[0112] In some embodiments of the present application, the thermal curing agent is selected from one or more of isocyanate curing agents and amine curing agents. Further, the thermal curing agent is preferably an isocyanate curing agent, the functional group of the curing agent is ≥2, and the isocyanate value is 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, dodecamethylene 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 the present application, the photoinitiator is at least one of acetophenone, dibenzoyl ketone, benzil ketal, benzophenone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-phenylpropanone, and benzoin dimethyl ether.

[0116] The embodiment of the present application further provides a UV viscosity-reducing adhesive, which includes the above-mentioned polyurethane oligomer or a polyurethane oligomer prepared by the above-mentioned method for preparing the polyurethane oligomer.

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

[0118] Step (21) introducing protective gas into the reaction container.

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

[0120] Step (22) adds diisocyanate, catalyst and second solvent (ie solvent B) into a reaction container in a protective gas environment, and then adds diol to react to obtain a third reaction solution.

[0121] Specifically, after adding a mixture of diisocyanate, catalyst and solvent B into a reaction container, the temperature is raised to 45° C. to 55° C., and then the diol is slowly added dropwise for reaction, the addition time is 1 h to 3 h, and after the addition is completed, the reaction is kept warm for 1 h to 3 h.

[0122] Step (23) continues to add hydroxyl-containing acrylate and polymerization inhibitor into the reaction container and continues to react for a period of time, and detects whether the raw materials have reacted completely to obtain a polyurethane oligomer.

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

[0124] Specifically, a mixed solution of hydroxyl-containing acrylate and polymerization inhibitor is added dropwise into a reaction container for 1 hour to 2 hours, and the mixture is kept warm for reaction for 2 hours to 4 hours after the addition is completed.

[0125] Specifically, the step of detecting whether the raw materials have been reacted comprises: taking the reaction solution for infrared analysis, if there is no 2240cm -1If a peak appears near the reaction solution, the reaction is considered complete, or the reaction solution is taken for -NCO value titration. 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 inhibitor in step (23) includes at least one of hydroquinone and p-hydroxyanisole.

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

[0130] In some embodiments of the present 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 the reaction method is also a solution polymerization reaction, and the solvent, as a carrier of the reaction, has a certain influence on the polymerization activity and the gel effect. When the solid content is set within the range of 40% to 60%, the polymerization reaction rate is moderate, the viscosity is moderate, and the temperature is easy to control.

[0131] A sixth aspect of the embodiment of the present application further provides a method for preparing a UV anti-viscosity tape, comprising the following steps:

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

[0133] Specifically, photosensitive polyacrylate, polyurethane oligomer, thermal curing agent and photoinitiator are added into a container, stirred evenly, and allowed to stand for defoaming to obtain UV viscosity-reducing adhesive. In terms of mass fraction, the photosensitive polyacrylate: polyurethane oligomer: thermal curing agent: photoinitiator is 100: (5-50): (0.4-10): (0.4-5).

[0134] Further, before standing and defoaming, solvent C can also be added to the UV viscosity-reducing adhesive to adjust the viscosity. Exemplarily, the viscosity of the UV viscosity-reducing adhesive is 300cps to 3000cps, preferably 600cps to 1500cps. Specifically, solvent C is not particularly limited, and exemplarily, the 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, toluene, etc. It should be noted that solvent A and solvent C can be the same or different, and are not limited here.

[0135] Step (32) is to coat the UV viscosity reducing adhesive on the release film.

[0136] Specifically, a coating machine is used to evenly coat the adhesive on the release film. Exemplarily, the release film is PET.

[0137] Step (33) dries the release film coated with the UV viscosity-reducing adhesive, and then coats it on the substrate film to obtain an adhesive tape.

[0138] Specifically, the release film coated with UV viscosity-reducing adhesive is placed in an oven to dry the solvent at a temperature of 60°C to 100°C for 1 min to 3 min, and then coated on the substrate film to obtain an adhesive tape. Exemplarily, the substrate film is one of EVA, PET, PO, and PVC.

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

[0140] Step (34) The above adhesive tape is placed in an oven for curing at a temperature of 40 to 70° C. for 24 to 72 hours. After curing is completed, a UV anti-viscosity tape is obtained.

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

[0142] The UV adhesive tape in this application is further described below in conjunction with specific examples and experimental data.

[0143] Example 1

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

[0145] Solvent: 200 parts of ethyl acetate.

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

[0147] Under nitrogen protection, add 30% of synthetic monomers except the modified monomers and 2 times the mass of solvent (ethyl acetate) into the reaction bottle, raise the temperature to 74°C, start stirring, and add 30% of synthetic monomers except the modified monomers, 1 times the mass of solvent and 50% of the initiator mixture into the reaction bottle. The addition time is 2 hours. After the addition is completed, keep the reaction warm for 1 hour. Then the temperature is raised to 78°C, and the remaining synthetic monomers except the modified monomer, and 1 times the mass of the solvent and the remaining initiator mixture are added dropwise into the reaction bottle. The dropping time is 3 hours. After the dropping is completed, the reaction is kept warm for 1 hour. The temperature is then raised to 82°C for reaction for 2 hours. The temperature is then lowered to 50°C, and 70% of the remaining solvent and 0.1 parts of p-hydroxyanisole are added and stirred for 1 hour. The final remaining solvent, modified monomer, and 0.1 parts of dibutyltin dilaurate mixture are continued to be dropped for 1 hour. After the dropping is completed, the reaction is kept warm for 4 hours. After the reaction is completed, the temperature is lowered and the material is discharged to obtain a photosensitive polyacrylate (numbered photosensitive polyacrylate 1) for standby use.

[0148] (2) The preparation of polyurethane oligomer comprises the following steps:

[0149] Under nitrogen protection, diisocyanate (22.3 parts of isophorone diisocyanate), 0.12 parts of dibutyltin dilaurate and 120 parts of ethyl acetate were added to the reaction bottle, the temperature was raised to 50°C, and then diol (100 parts of poly(1,6-hexanediol phthalate) (Mw: 2000)) was slowly added dropwise for 2 hours, and the reaction was kept warm for 1 hour after the addition was completed. Hydroxyl acrylate (5.8 parts of hydroxyethyl acrylate and 14.9 parts of pentaerythritol triacrylate) and 0.12 parts of p-hydroxyanisole were continued to be added dropwise to the reaction bottle for 1 hour, and the reaction was kept warm for 3 hours after the addition was completed. No isocyanate group peak was detected by infrared detection, and the polyurethane oligomer was obtained by cooling and discharging for standby use (numbered polyurethane oligomer 1).

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

[0151] Add 100 parts of photosensitive polyacrylate, 30 parts of polyurethane oligomer, 2 parts of thermal curing agent (-NCO value is 18%), and 2.4 parts of photoinitiator (benzoin dimethyl ether) into a container, stir evenly, and let it stand to defoam to obtain a glue solution. Use a coating machine to evenly coat the above glue solution on the release film; put it in an oven to dry the solvent at a temperature of 90°C for 1.5 minutes, and then transfer it to the substrate film to obtain a tape; put the tape in an oven to mature at a temperature of 50°C for 70 hours, and after the maturation is completed, a UV anti-adhesive tape is obtained.

[0152] Example 2

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

[0154] Solvent: 170 parts of ethyl acetate.

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

[0156] Under nitrogen protection, add 20% of synthetic monomers except the modified monomers and 1.5 times the mass of solvent (ethyl acetate) into the reaction bottle, raise the temperature to 72°C, start stirring, and add 50% of synthetic monomers except the modified monomers, 1.5 times the mass of solvent and 50% of the initiator mixture into the reaction bottle. The addition time is 1.5 hours. After the addition is completed, keep the reaction warm for 1.5 hours. Then the temperature is raised to 76°C, and the remaining synthetic monomers except the modified monomer, and 0.8 times the mass of the solvent and the remaining initiator mixture are added dropwise into the reaction bottle. The dropping time is 2.5 hours. After the dropping is completed, the reaction is kept warm for 0.6 hours. The temperature is then raised to 81°C for 1.5 hours. The temperature is then lowered to 45°C, and 70% of the remaining solvent and 0.15 parts of p-hydroxyanisole are added and stirred for 1 hour. The final remaining solvent, modified monomer, and 0.15 parts of dibutyltin dilaurate mixture are continued to be dropped for 0.8 hours. After the addition is completed, the reaction is kept warm for 5 hours. After the reaction is completed, the temperature is lowered and the material is discharged to obtain a photosensitive polyacrylate (numbered photosensitive polyacrylate 2) for standby use.

[0157] (2) The preparation of polyurethane oligomer comprises the following steps:

[0158] Under nitrogen protection, diisocyanate (34.8 parts of toluene-2,4-diisocyanate), 0.12 parts of dioctyl tin, and 260 parts of acetone were added to the reaction bottle, heated to 45°C, and then diol (100 parts of polyadipate-1,4-butylene glycol ester diol (Mw: 1000)) was slowly added dropwise for reaction, and the addition was continued for 3 hours. After the addition was completed, the reaction was kept warm for 2 hours. Hydroxyl acrylate (15.6 parts of hydroxypropyl acrylate and 23.8 parts of pentaerythritol triacrylate) and 0.12 parts of p-hydroxyanisole were continued to be added dropwise to the reaction bottle for 1.5 hours. After the addition was completed, the reaction was kept warm for 4 hours. No isocyanate group peak was detected by infrared detection, and the polyurethane oligomer was obtained by cooling and discharging for standby use (numbered polyurethane oligomer 2).

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

[0160] Add 100 parts of photosensitive polyacrylate 2, 20 parts of polyurethane oligomer 2, 1.5 parts of thermal curing agent (-NCO value is 20%), and 1.8 parts of photoinitiator (1-hydroxy-cyclohexyl benzophenone) into a container, stir evenly, and let it stand to defoam to obtain a glue solution. Use a coating machine to evenly coat the above glue solution on the release film; put it in an oven to dry the solvent at a temperature of 80°C for 2 minutes, and then transfer it to the substrate film to obtain a tape. Put the tape in an oven to mature at a temperature of 60°C for 60 hours. After the maturation is completed, a UV anti-viscosity tape is obtained.

[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 of toluene.

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

[0165] Under nitrogen protection, add 33% of synthetic monomers except the modified monomers and 2 times the mass of solvent (toluene) into the reaction bottle, raise the temperature to 75°C, start stirring, and add 33% of synthetic monomers except the modified monomers, 1 times the mass of solvent and 50% of the initiator mixture into the reaction bottle. The addition time is 2 hours. After the addition is completed, keep the reaction warm for 1 hour. Then the temperature was raised to 79°C, and the remaining synthetic monomers except the modified monomers, and 1 times the mass of the solvent and the remaining initiator mixture were added dropwise into the reaction bottle. The dropping time was 3 hours. After the dropping was completed, the mixture was kept warm for reaction for 1 hour. The temperature was raised to 83°C for reaction for 2 hours. The temperature was lowered to 50°C, and 70% of the remaining solvent and 0.2 parts of a mixture of hydroquinone were added and stirred for 1 hour. The final remaining solvent, modified monomer, and 0.2 parts of a mixture of dibutyltin dilaurate were continued to be dropped for 1 hour. After the dropping was completed, the mixture was kept warm for reaction for 4 hours. After the reaction was completed, the temperature was lowered and the material was discharged to obtain a photosensitive polyacrylate (numbered photosensitive polyacrylate 3) for standby use.

[0166] (2) The preparation of polyurethane oligomer comprises the following steps:

[0167] Under nitrogen protection, diisocyanate (11.1 parts of isophorone diisocyanate), 0.12 parts of dibutyltin dilaurate, and 80 parts of ethyl acetate were added to the reaction bottle, the temperature was raised to 50°C, and then diol (100 parts of polyneopentyl glycol adipate diol (Mw: 4000)) was slowly added dropwise for reaction, and the addition was continued for 2 hours. After the addition was completed, the reaction was kept warm for 1 hour. Hydroxyl acrylate (3.6 parts of hydroxybutyl acrylate and 7.4 parts of pentaerythritol triacrylate) and 0.12 parts of hydroquinone were continued to be added to the reaction bottle, and the addition was continued for 1 hour. After the addition was completed, the reaction was kept warm for 3 hours. No isocyanate group peak was detected by infrared detection, and the polyurethane oligomer was obtained by cooling and discharging for standby use (numbered polyurethane oligomer 3).

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

[0169] Add 100 parts of photosensitive polyacrylate 3, 12 parts of polyurethane oligomer 3, 7 parts of thermal curing agent (-NCO value 6%), and 1 part of photoinitiator (2-hydroxy-2-methyl-1-phenylacetone) into a container, stir evenly, and let it stand to defoam to obtain a glue solution. Use a coating machine to evenly coat the above glue solution on the release film; put it in an oven to dry the solvent at a temperature of 90°C for 1.5 minutes, and then transfer it to the substrate film to obtain a tape. Put the tape in an oven for aging at a temperature of 50°C for 72 hours. After aging is completed, a UV anti-viscosity tape is obtained.

[0170] Example 4

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

[0172]

[0173] Solvent: 150 parts of ethyl acetate.

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

[0175] Under nitrogen protection, add 40% of the synthetic monomers except the modified monomers and 2.5 times the mass of the solvent (ethyl acetate) into the reaction bottle, raise the temperature to 74°C, start stirring, and add 25% of the synthetic monomers except the modified monomers, 0.5 times the mass of the solvent and 50% of the initiator mixture into the reaction bottle. The addition time is 3 hours. After the addition is completed, keep the reaction warm for 0.6 hours. The temperature was raised to 78°C, and the remaining synthetic monomers except the modified monomers, and 0.5 times the mass of the solvent and the remaining initiator mixture were added dropwise into the reaction bottle. The addition time was 2 hours. After the addition was completed, the mixture was kept warm for reaction for 1.5 hours. The temperature was raised to 82°C for reaction for 2.5 hours. The temperature was lowered to 55°C, and 70% of the remaining solvent and 0.25 parts of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomer, and 0.15 parts of dibutyltin dilaurate mixture were continued to be added dropwise for 1 hour. After the addition was completed, the mixture was kept warm for reaction for 4 hours. After the reaction was completed, the temperature was lowered and the material was discharged to obtain a photosensitive polyacrylate (numbered photosensitive polyacrylate 4) for standby use.

[0176] (2) The preparation of polyurethane oligomer comprises 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 the reaction bottle, the temperature was raised to 50°C, and then diol (100 parts of polypropylene glycol (Mw: 600)) was slowly added dropwise for reaction, and the addition was continued for 2 hours. After the addition was completed, the reaction was kept warm for 1 hour. Hydroxyl acrylate (38.7 parts of hydroxyethyl acrylate) and 0.13 parts of p-hydroxyanisole were continued to be added dropwise to the reaction bottle, and the addition was continued for 2 hours. After the addition was completed, the reaction was kept warm for 2.5 hours. No isocyanate group peak was detected by infrared detection, and the polyurethane oligomer was obtained by cooling and discharging for standby use (numbered polyurethane oligomer 4).

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

[0179] Add 100 parts of photosensitive polyacrylate 4, 35 parts of polyurethane oligomer 4, 0.8 parts of thermal curing agent (-NCO value 15%), and 3 parts of photoinitiator (benzoin dimethyl ether) into a container, stir evenly, and let it stand to defoam to obtain a glue solution. Use a coating machine to evenly coat the above glue solution on the release film; put it in an oven to dry the solvent at a temperature of 100°C for 1.2 minutes, and then transfer it to the substrate film to obtain a tape. Put the tape in an oven to mature at a temperature of 40°C for 72 hours. After the maturation is completed, a UV anti-viscosity tape is obtained.

[0180] Example 5

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

[0182] Solvent: 200 parts of ethyl acetate.

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

[0184] Under nitrogen protection, add 30% of synthetic monomers except the modified monomers and 2 times the mass of solvent (ethyl acetate) into the reaction bottle, raise the temperature to 74°C, start stirring, and add 30% of synthetic monomers except the modified monomers, 1 times the mass of solvent and 50% of the initiator mixture into the reaction bottle. The addition time is 2 hours. After the addition is completed, keep the reaction warm for 1 hour. The temperature was raised to 78°C, and the remaining synthetic monomers except the modified monomers, and a solvent with a weight of 1 times that of the solvent and the remaining initiator mixture were added dropwise into the reaction bottle for 3 hours. After the addition was completed, the mixture was kept warm for 1 hour. The temperature was raised to 82°C for 2 hours. The mixture was cooled to 50°C, and 70% of the remaining solvent and 0.1 part of p-hydroxyanisole were added and stirred for 1 hour. The final remaining solvent, modified monomer, and 0.1 part of dibutyltin dilaurate mixture were continued to be added dropwise for 1 hour. After the addition was completed, the mixture was kept warm for 4 hours. After the reaction was completed, the temperature was lowered and the material was discharged to obtain a photosensitive polyacrylate (numbered as photosensitive polyacrylate 1) for standby use.

[0185] (2) The preparation of polyurethane oligomer comprises the following steps:

[0186] Under nitrogen protection, diisocyanate (22.3 parts of isophorone diisocyanate), 0.12 parts of dibutyltin dilaurate and 120 parts of ethyl acetate were added to the reaction bottle, the temperature was raised to 50°C, and then diol (100 parts of poly(1,6-hexanediol phthalate) (Mw: 2000)) was slowly added dropwise for 2 hours, and the reaction was kept warm for 1 hour after the addition was completed. Hydroxyl acrylate (5.8 parts of hydroxyethyl acrylate and 14.9 parts of pentaerythritol triacrylate) and 0.12 parts of p-hydroxyanisole were continued to be added dropwise to the reaction bottle for 1 hour, and the reaction was kept warm for 3 hours after the addition was completed. No isocyanate group peak was detected by infrared detection, and the polyurethane oligomer was obtained by cooling and discharging for standby use (numbered polyurethane oligomer 1).

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

[0188] Add 100 parts of photosensitive polyacrylate 1, 4 parts of polyurethane oligomer 1, 13 parts of pentaerythritol triacrylate, 13 parts of trimethylolpropane triacrylate, 2 parts of thermal curing agent (-NCO value is 18%), and 2.4 parts of photoinitiator (benzoin dimethyl ether) into a container, stir evenly, and let it stand to defoam to obtain a glue solution. Use a coating machine to evenly coat the above glue solution on the release film; put it in an oven to dry the solvent at a temperature of 90°C for 1.5 minutes, and then transfer it to the substrate film to obtain a tape. Put the tape in an oven for aging at a temperature of 50°C for 70 hours. After aging is completed, a UV anti-viscosity tape is obtained.

[0189] The difference between Example 5 and Example 1 is that when preparing the UV anti-viscosity 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 in Comparative Example 1, no modified monomer is used in the preparation of the photosensitive polyacrylate.

[0192] Comparative Example 2

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

[0194] Comparative Example 3

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

[0196] Comparative Example 4

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

[0198] Performance Testing

[0199] The following performance tests were performed on the UV adhesive tapes in the above embodiments and comparative examples:

[0200] Peel force: 180° peel force test was carried out according to GB / T 2792-2014, sample size 25mm×300mm.

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

[0202] Residual glue: Use a microscope to observe whether there is residual glue on the chip after picking up.

[0203] Cutting quality: Cut three wafers and observe under a microscope that the surface damage size of all chips is less than 30×5μm and the vertical damage size is less than 15μm, which is qualified.

[0204] Picking performance: After cutting three wafers, if all chips can be picked up successfully without damage or flying materials, it is qualified.

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

[0206] Table 1

[0207]

[0208]

[0209] It can be seen from Examples 1 to 5, Comparative Examples 1 to 4 and Table 1 that adding modified monomers to the reaction raw materials of polyacrylate can make the prepared UV detackifying tape have a larger peeling force before UV irradiation, and a lower peeling force after UV irradiation, and has a better detackifying effect.

[0210] It can be seen from the test results of Example 5 that its viscosity reduction effect is improved compared with that of Comparative Example 1, but it can be seen from the comparison between Example 1 and Example 5 that the use of photosensitive small molecules instead of polyurethane oligomers in UV viscosity-reducing tapes will lead to a decrease in the pre-UV peeling force of the UV viscosity-reducing adhesive, a poor viscosity reduction effect, and the presence of residual adhesive, and the cutting and picking properties are also unqualified. In addition, after UV irradiation, the crosslinking degree of the entire adhesive layer is greatly increased, and the unreacted photosensitive small molecules are easily free in the adhesive layer and difficult to react, resulting in a lower UV curing rate than other experimental examples.

[0211] The technical solutions provided by the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A photosensitive polyacrylate, characterized in that: The raw materials for preparing the photosensitive polyacrylate include synthetic monomers, and the synthetic monomers include: soft monomers, hard monomers, functional monomers and modified monomers; The functional monomer includes a hydroxyl-containing acrylic monomer, and the modified monomer is selected from any one of the following formulas (1) to (3): as well as Wherein, n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

2. The photosensitive polyacrylate according to claim 1, characterized in that By mass, the soft monomer: the hard monomer: the functional monomer: the modified monomer is (45-85): (5-45): (6-12): (2-30).

3. The photosensitive polyacrylate according to claim 2, characterized in that: The hydroxyl-containing acrylic monomer includes at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate; and / or The functional monomers also include acrylic monomers not containing hydroxyl groups.

4. The photosensitive polyacrylate according to claim 3, characterized in that The acrylic monomer not containing a hydroxyl group includes at least one of acrylic acid, methacrylic acid, β-acryloxypropionic acid, glycidyl methacrylate, and acrylamide.

5. The photosensitive polyacrylate according to any one of claims 1 to 4, characterized in that: The soft monomer comprises 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, vinyl acetate, N-vinyl pyrrole, styrene, and acrylonitrile; and / or The raw material for preparing the polyacrylate further comprises a first solvent, wherein the first solvent: the synthetic monomer is (40-70): (30-60) by mass; and / or The synthetic raw material of the polyacrylate also includes a first initiator. By mass, the ratio of the first initiator to the synthetic monomer is (0.05 to 0.5):

100.

6. The photosensitive polyacrylate according to claim 5, 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, azobisisoheptylnitrile, dibenzoyl peroxide, dodecyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, diisopropyl peroxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, tert-butyl perbenzoate, tert-butyl pervalerate, diethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, sodium persulfate, and ammonium persulfate.

7. A method for preparing a photosensitive polyacrylate, characterized in that: The preparation method comprises: Adding part of the synthetic monomers except the modified monomer and the first solvent into the reaction container, raising the temperature to 70° C. to 75° C. to react and obtain a first reaction liquid; Continue to raise the temperature to 76° C. to 80° C., add the remaining synthetic monomers except the modified monomers to the first reaction liquid, and continue to react to obtain a second reaction liquid; The second reaction liquid is cooled to 45° C. to 60° C., and a polymerization inhibitor and a modified monomer are added to continue the reaction to obtain the photosensitive polyacrylate; Among them, synthetic monomers include: soft monomers, hard monomers, functional monomers and modified monomers; The functional monomer includes a hydroxyl-containing acrylic monomer, and the modified monomer is selected from any one of the following formulas (1) to (3): as well as Wherein, n8 is an integer from 1 to 3, and R7 is hydrogen or methyl.

8. A UV viscosity-reducing adhesive, characterized in that: The UV viscosity-reducing adhesive comprises the photosensitive polyacrylate according to any one of claims 1 to 6 or the photosensitive polyacrylate prepared by the method for preparing polyacrylate according to claim 7.

9. The UV viscosity-reducing adhesive according to claim 8, characterized in that: The UV viscosity-reducing adhesive further comprises a polyurethane oligomer, a thermal curing agent and a photoinitiator, and the ratio of the photosensitive polyacrylate: polyurethane oligomer: thermal curing agent: photoinitiator is 100: (5-50): (0.4-10): (0.4-5) by weight; and / or The UV viscosity-reducing adhesive does not include reactive diluents or reactive monomers.

10. The UV viscosity-reducing adhesive according to claim 8, characterized in that: The UV viscosity-reducing adhesive further comprises a polyurethane oligomer, and the structure of the polyurethane oligomer is shown in the following formula (4): 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; wherein n1 is an integer from 7 to 190, and R3 is methyl or hydrogen; further, n1 is an integer from 12 to 120; Wherein, n2 is an integer from 1 to 50, R4 includes at least one of formula (13) to formula (16), and R5 includes at least one of formula (17) to formula (21); further, n2 is an integer from 1 to 30; Wherein, R6 is methyl or hydrogen, and n7 is an integer from 1 to 3; Wherein, n3 is an integer from 1 to 22; Wherein, n4 is an integer from 1 to 24; Wherein, n5 is an integer from 1 to 7; Wherein, n3 is an integer from 1 to 3; 11. A UV anti-viscosity tape, characterized in that: The UV anti-viscosity tape comprises the UV anti-viscosity adhesive according to any one of claims 8 to 10.

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