UV alkali-resistant glue for UTG glass and preparation method of UV alkali-resistant glue

Abstract

The invention discloses UV alkali-resistant glue for UTG glass and a preparation method of the UV alkali-resistant glue. The UV alkali-resistant glue for the UTG glass comprises a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant reactive diluent, a photoinitiator, a photo-thermal double-response dispergator, an adhesion promoter and a stability additive. The heterocyclic modified polyurethane acrylate prepolymer is obtained by synthesizing nitrogen-containing heterocyclic dihydric alcohol, diisocyanate and hydroxyl-containing acrylate. The heterocycle modified polyurethane acrylate prepolymer of the UV alkali-resistant glue simultaneously contains ureido, ester group, acrylate group and benzimidazole nitrogen-containing heterocycle structure, and can form coordinate bonds with alkali molecules to reduce attack of alkali to ester bonds, so that the UV alkali-resistant glue is kept stable in a molten alkali salt environment at the temperature of 400 DEG C or above. The initial peel strength of the UV alkali-resistant glue can reach 4.5 N / 25mm to 4.8 N / 25mm, the peel strength after dispergation is reduced to be less than 0.3 N / 25mm, and the dual requirements on fixing force and easy separation in the UTG glass processing process are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a UV alkali-resistant glue for UTG glass and a preparation method thereof. BACKGROUND

[0002] As the core substrate of flexible display, ultra-thin glass (UTG) usually has a thickness of 0.01mm-0.09mm. Due to its extremely thin thickness and inherent brittleness, UTG glass is not suitable for direct monolithic processing, and needs to be temporarily fixed together by using special glue for cutting, grinding and chemical strengthening processes, and then separated completely after processing.

[0003] The current UTG processing glue mainly faces two technical challenges: first, it needs to maintain stability in the strong alkaline chemical strengthening process, usually using molten alkali salt above 400℃ to protect the UTG glass from damage; second, it needs to be removed simply and completely after processing without leaving residual glue. However, some UV hydrolysis glues on the market can be delaminated in hot water, but their alkali resistance is insufficient, which can easily lead to glue layer failure or contamination of the alkali solution during chemical strengthening. Some glues on the market have good alkali resistance, but they are difficult to remove and are prone to residual problems. The UV debonding glue technology recently developed by China Aerospace Science and Technology Group has made progress in the semiconductor field, but it mainly targets precision cutting protection of wafers and PCB / FPC, and still has deficiencies in balancing the high-temperature alkali resistance and hydrolysis performance required for UTG glass processing.

[0004] Therefore, in view of the deficiencies of the prior art, it is necessary to provide a UV alkali-resistant glue for UTG glass and a preparation method thereof to solve the deficiencies of the prior art. SUMMARY

[0005] One of the purposes of the present application is to provide a UV alkali-resistant glue for UTG glass to avoid the deficiencies of the prior art. The UV alkali-resistant glue for UTG glass can provide effective temporary fixing and protection during UTG glass processing, especially maintaining structural stability in strong alkali environments such as chemical strengthening, and can be completely removed by simple photothermal treatment after processing without leaving residual glue.

[0006] The above purposes of the present application are achieved by the following technical measures: The present application provides a UV alkali-resistant glue for UTG glass, which comprises a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a light-thermal dual-responsive debonding agent, an adhesion promoter and a stability aid.

[0007] Preferably, the above-mentioned heterocycle-modified polyurethane acrylate prepolymer is synthesized by using a nitrogen-containing heterocycle diol, a diisocyanate and a hydroxyl-containing acrylate.

[0008] In the UV alkali-resistant glue, the components are as follows in parts by weight: Heterocycle-modified polyurethane acrylate prepolymer: 30-50 parts; Alkali-resistant active diluent: 20-40 parts; Photoinitiator: 3-8 parts; Photo-thermal dual-responsive debonder: 5-15 parts; Adhesion promoter: 1-5 parts; Stability aid: 0.5-2 parts.

[0009] In the UV alkali-resistant glue, the components are as follows in parts by weight: Heterocycle-modified polyurethane acrylate prepolymer: 40 parts; Alkali-resistant active diluent: 30 parts; Photoinitiator: 5 parts; Photo-thermal dual-responsive debonder: 10 parts; Adhesion promoter: 3 parts; Stability aid: 1 part.

[0010] Preferably, the above-mentioned heterocycle-modified polyurethane acrylate prepolymer is prepared by the following method: A1. Under nitrogen protection, benzimidazole diol and isophorone diisocyanate are added into a reactor, then dibutyltin dilaurate and butanone are added, and the mixture is reacted at 73-78°C for 2-4h to obtain an intermediate; A2. Hydroxyethyl acrylate is added into the intermediate, and the mixture is reacted at 58-62°C for 3-6h to obtain the heterocycle-modified polyurethane acrylate prepolymer.

[0011] In the preparation of the heterocycle-modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1: (1.8-2.2): (1.8-2.2); The mass of dibutyltin dilaurate is 0.05%-0.2% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate; The mass of butanone is 50%-80% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0012] In the preparation of the heterocycle-modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:2:2; The mass of dibutyltin dilaurate is 0.1% of the total mass of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate; The mass of butanone is 60% of the total mass of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate.

[0013] Preferably, the alkali-resistant active diluent is a mixture of a fluorine-containing acrylate monomer and a benzoxazole monomer.

[0014] Preferably, the photoinitiator is a mixture of a free radical type photoinitiator and a cationic type photoinitiator.

[0015] In the alkali-resistant active diluent, the weight ratio of the fluorine-containing acrylate monomer and the benzoxazole monomer is (2-4):1.

[0016] In the photoinitiator, the weight ratio of the free radical type photoinitiator and the cationic type photoinitiator is (2-6):(1-2).

[0017] Preferably, the photo-thermal dual-responsive debonder is a selenium-containing polyurethane of PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond.

[0018] Preferably, the fluorine-containing acrylate monomer is perfluorohexyl ethyl acrylate.

[0019] Preferably, the benzoxazole monomer is acryloyloxyethyl benzoxazole.

[0020] Preferably, the free radical type photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.

[0021] Preferably, the cationic type photoinitiator is bis(4-tert-butylphenyl) iodonium hexafluorophosphate.

[0022] Preferably, the selenium-containing polyurethane is PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond.

[0023] Preferably, the adhesion promoter is γ-glycidyl ether oxypropyl trimethoxysilane.

[0024] Preferably, the stability aid is β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate.

[0025] One of the purposes of the present application is to provide a preparation method of UV alkali-resistant glue for UTG glass to avoid the shortcomings of the prior art. The UV alkali-resistant glue obtained by the preparation method can provide effective temporary fixing and protection during the processing of UTG glass, especially stability in a strong alkali environment such as chemical strengthening, and can be completely removed by simple photothermal treatment after processing is completed without leaving residual glue.

[0026] The present application provides a preparation method of UV alkali-resistant glue for UTG glass as described above, characterized in that it comprises the following steps: S1, mixing a heterocyclic modified polyurethane acrylate prepolymer and an alkali-resistant active diluent to obtain a mixture I; S2, adding a photoinitiator, a light-thermal dual-responsive debonding agent and a stability aid to the mixture I of S1 and mixing to obtain a mixture II; S3, degassing the mixture II under vacuum to obtain the UV alkali-resistant glue.

[0027] The present application provides a preparation method of UV alkali-resistant glue for UTG glass as described above, characterized in that it comprises the following steps: S1, mixing a heterocyclic modified polyurethane acrylate prepolymer and an alkali-resistant active diluent at 48°C-52°C for 0.5h-1h to obtain a mixture I; S2, adding a photoinitiator, a light-thermal dual-responsive debonding agent and a stability aid to the mixture I of S1 and mixing for 1h-3h to obtain a mixture II; S3, degassing the mixture II under a vacuum degree of-0.1MPa for 10min-60min to obtain the UV alkali-resistant glue.

[0028] The application discloses a UV alkali-resistant glue for UTG glass and a preparation method thereof. The UV alkali-resistant glue for UTG glass comprises a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a photo-thermal dual-responsive debonding agent, an adhesion promoter and a stability aid. The heterocyclic modified polyurethane acrylate prepolymer is synthesized by using a nitrogen-containing heterocyclic diol, a diisocyanate-containing and a hydroxyl acrylate. In the UV alkali-resistant glue, the heterocyclic modified polyurethane acrylate prepolymer accounts for 30-50 parts by weight, the alkali-resistant active diluent accounts for 20-40 parts by weight, the photoinitiator accounts for 3-8 parts by weight, the photo-thermal dual-responsive debonding agent accounts for 5-15 parts by weight, the adhesion promoter accounts for 1-5 parts by weight and the stability aid accounts for 0.5-2 parts by weight. The heterocyclic modified polyurethane acrylate prepolymer of the UV alkali-resistant glue contains a urea group, an ester group, an acrylate group and a benzimidazole nitrogen-containing heterocyclic structure, can form a coordination bond with alkali molecules, reduces the attack of alkali on an ester bond, and can maintain the structural integrity after being soaked in a 400°C molten alkali salt for 4 hours. The initial peeling strength of the UV alkali-resistant glue can reach 4.5-4.8 N / 25 mm, and the peeling strength can be reduced to less than 0.3 N / 25 mm after debonding, thereby meeting the dual requirements of fixing force and easy separability in the processing of UTG glass. The glue has the advantages of fast curing speed, high transparency after curing, convenient laser cutting positioning and alignment mark identification, certain flexibility and the like, can adapt to the slight deformation of UTG glass in the processing, and can be easily removed in warm water without leaving residual glue. DETAILED DESCRIPTION

[0029] The technical scheme of the application is further described in combination with the following examples. In the following examples, the experimental methods are conventional methods unless otherwise specified. In the following examples, the raw materials, reagent materials and the like can be purchased from conventional biochemical reagent stores or medicine business enterprises unless otherwise specified. The CAS of perfluoroalkyl ethyl acrylate is 65605-70-1, which is purchased from Fuxin Ruifeng Fluorine Chemical Co., Ltd. Acryloyloxyethyl benzoxazole is a commonly used ultraviolet light curing functional monomer, which is purchased from Changxing Material Industrial Co., Ltd. 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO is purchased from BASF. Bis(4-tert-butylphenyl) iodonium hexafluorophosphate is purchased from Sartomer, USA. PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond is purchased from Xi'an Qiyue Biological Technology Co., Ltd. Gamma-glycidyl ether oxypropyl trimethoxysilane KH-560 is purchased from Dow Corning. Beta-(3,5-di-tert-butyl-4-hydroxyphenyl) propyl octadecyl alcohol (antioxidant 1076) is purchased from BASF.

[0030] Example 1

[0031] The application discloses a UV alkali-resistant glue for UTG glass, which comprises a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a photo-thermal dual-responsive debonder, an adhesion promoter and a stability aid. The heterocyclic modified polyurethane acrylate prepolymer is synthesized by using a nitrogen-containing heterocyclic diol, a diisocyanate-containing and a hydroxyl acrylate.

[0032] In the UV alkali-resistant glue, the components are as follows in terms of weight parts: the heterocyclic modified polyurethane acrylate prepolymer: 30-50 parts; the alkali-resistant active diluent: 20-40 parts; the photoinitiator: 3-8 parts; the photo-thermal dual-responsive debonder: 5-15 parts; the adhesion promoter: 1-5 parts; the stability aid: 0.5-2 parts.

[0033] The heterocyclic modified polyurethane acrylate prepolymer is prepared by the following method: A1, under nitrogen protection, benzimidazole diol and isophorone diisocyanate are added into a reactor, then dibutyltin dilaurate and butanone are added, and reaction is carried out at 73-78°C for 2-4 hours to obtain an intermediate; A2, hydroxyethyl acrylate is added into the intermediate to react, and reaction is carried out at 58-62°C for 3-6 hours to obtain the heterocyclic modified polyurethane acrylate prepolymer. The molecular weight of the heterocyclic modified polyurethane acrylate prepolymer is 8000-12000, and the glass transition temperature (Tg) is -10-0°C.

[0034] In the preparation of the heterocyclic modified polyurethane acrylate prepolymer, the molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:(1.8-2.2):(1.8-2.2); the mass of dibutyltin dilaurate is 0.05%-0.2% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate; and the mass of butanone is 50%-80% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0035] It should be noted that the heterocyclic modified polyurethane acrylate prepolymer of the present application significantly improves the strong alkali resistance of the adhesive layer by introducing the nitrogen-containing heterocyclic structure of benzimidazole into the polyurethane acrylate main chain. These heterocyclic structures can form coordinate bonds with alkali molecules, reducing the attack of alkali on ester bonds, so that the structure remains intact after immersion in molten alkali salt at 400°C for 4 hours. Moreover, by adjusting the ratio of soft and hard segments and the crosslinking density of the heterocyclic modified polyurethane acrylate prepolymer, the precise control of the adhesive bonding strength can be achieved, the initial peel strength can reach 4.5N / 25mm-4.8N / 25mm, and the peel strength after debonding can be reduced to less than 0.3N / 25mm, meeting the dual requirements of fixing force and easy separability during UTG glass processing.

[0036] The alkali-resistant active diluent is a mixture of fluorine-containing acrylate monomer and benzoxazole monomer. The photoinitiator is a mixture of free radical photoinitiator and cationic photoinitiator.

[0037] In the alkali-resistant active diluent, the weight ratio of the fluorine-containing acrylate monomer and the benzoxazole monomer is (2-4):1; In the photoinitiator, the weight ratio of the free radical photoinitiator and the cationic photoinitiator is (2-6):(1-2).

[0038] The fluorine-containing acrylate monomer is perfluorohexyl ethyl acrylate. The benzoxazole monomer is acryloyloxyethyl benzoxazole. The free radical photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide. The cationic photoinitiator is a mixture of bis(4-tert-butylphenyl) iodonium hexafluorophosphate. The selenium-containing polyurethane is PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond. The adhesion promoter is gamma-glycidyl ether oxypropyl trimethoxysilane. The stability aid is beta-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate.

[0039] The photo-thermal dual-responsive debonder of the present application uses selenium-containing polyurethane as a block copolymer, PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond. This EG-PUSeSe-PEG triblock polyurethane containing diselenium bond-Se-Se- is a polyurethane containing diselenium bond-Se-Se-. This compound was first synthesized by Professor Xu Huaping's research group at Tsinghua University and has formed a commercial product. The diselenium bond in this structure has a low bond energy and is easy to break under specific wavelength ultraviolet light (such as 365nm) or heating conditions above 85°C, triggering the degradation of the entire adhesive layer and achieving the effect of easy removal in warm water without leaving residue.

[0040] The preparation method of the UV alkali-resistant adhesive for UTG glass comprises the following steps: S1, mixing the heterocycle-modified polyurethane acrylate prepolymer and the alkali-resistant active diluent at 48°C-52°C for 0.5h-1h to obtain a mixture I; S2, adding a photoinitiator, a light-heat dual-responsive debonding agent and a stability aid to the mixture I of S1 and mixing for 1h-3h to obtain a mixture II S3, defoaming the mixture II under a vacuum degree of-0.1MPa for 10min-60min to obtain the UV alkali-resistant adhesive.

[0041] This embodiment is a general process description, and the specific parameters can be adjusted according to the preferred range or optimal value of the following Examples 2-4.

[0042] The UV alkali-resistant adhesive has a heterocycle-modified polyurethane acrylate prepolymer containing urea groups, ester groups, acrylate groups and a benzimidazole nitrogen-containing heterocyclic structure, which can form a coordination bond with alkali molecules, reducing the attack of alkali on the ester bond, so that the structure remains intact after soaking in a 400°C molten alkali salt for 4 hours. The initial peel strength of the UV alkali-resistant adhesive of the present application can reach 4.5N / 25mm-4.8N / 25mm, and the peel strength after debonding decreases to less than 0.3N / 25mm, meeting the dual requirements of fixing force and easy separability during UTG glass processing. The adhesive of the present application has a fast curing speed, high transparency after curing, and is convenient for laser cutting positioning and alignment mark identification, and has a certain flexibility, which can adapt to the slight deformation of UTG glass during processing. The UV alkali-resistant adhesive can be easily removed in warm water without leaving residue.

[0043] Example 2

[0044] A UV alkali-resistant adhesive for UTG glass, comprising a heterocycle-modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a light-heat dual-responsive debonding agent, an adhesion promoter and a stability aid.

[0045] The heterocycle-modified polyurethane acrylate prepolymer is synthesized from a nitrogen-containing heterocyclic diol, a diisocyanate-containing and a hydroxyl-containing acrylate.

[0046] In the UV alkali-resistant adhesive, the components are as follows in parts by weight: Heterocycle-modified polyurethane acrylate prepolymer: 30 parts Alkali-resistant active diluent: 40 parts; Photoinitiator: 3 parts; Light-heat dual-responsive debonding agent: 5 parts; Adhesion promoter: 1 part; Stability aid: 2 parts.

[0047] The preparation method of the heterocycle modified polyurethane acrylate prepolymer is as follows: A1, under the protection of nitrogen, benzimidazole diol and isophorone diisocyanate are added into a reactor, then dibutyltin dilaurate and butanone are added, and the reaction is carried out at 73°C for 4h to obtain an intermediate; the benzimidazole diol is 1H-benzimidazole-4,7-diol; A2, hydroxyethyl acrylate is added into the intermediate to react, and the reaction is carried out at 58°C for 6h to obtain the heterocycle modified polyurethane acrylate prepolymer.

[0048] In the preparation of the heterocycle modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:1.8:1.8; The mass of dibutyltin dilaurate is 0.05% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate; The mass of butanone is 80% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0049] The alkali-resistant active diluent is a mixture of perfluorohexylethyl acrylate and acryloyloxyethyl benzoxazole; in the alkali-resistant active diluent, the weight ratio of the perfluorohexylethyl acrylate and the acryloyloxyethyl benzoxazole is 2:1.

[0050] The photoinitiator is a mixture of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and bis(4-tert-butylphenyl) iodonium hexafluorophosphate. In the photoinitiator, the weight ratio of the 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and the bis(4-tert-butylphenyl) iodonium hexafluorophosphate is 2:2.

[0051] The photo-thermal dual-responsive debonder is a selenium-containing polyurethane of PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond; the adhesion promoter is γ-glycidyl ether oxypropyl trimethoxysilane; and the stability aid is β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate (antioxidant 1076).

[0052] The preparation method of the UV alkali-resistant glue for UTG glass comprises the following steps: S1, mixing the heterocycle modified polyurethane acrylate prepolymer and the alkali-resistant active diluent at 48°C for 1h to obtain a mixture I; S2, adding the photoinitiator, the photo-thermal dual-responsive debonder and the stability aid into the mixture I of S1 and mixing for 3h to obtain a mixture II S3, the mixture II is degassed for 60 min under a vacuum degree of -0.1 MPa to obtain the UV alkali-resistant glue.

[0053] Example 3

[0054] A UV alkali-resistant glue for UTG glass, other features being the same as those of Example 1, differs from the latter in that: The UV alkali-resistant glue comprises a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a light-heat dual-responsive debonder, an adhesion promoter and a stability aid. The heterocyclic modified polyurethane acrylate prepolymer is synthesized from a nitrogen-containing heterocyclic diol, a diisocyanate-containing and a hydroxyl-containing acrylate. In the UV alkali-resistant glue, the components are present in the following amounts by weight: The heterocyclic modified polyurethane acrylate prepolymer: 50 parts; The alkali-resistant active diluent: 20 parts; The photoinitiator: 8 parts; The light-heat dual-responsive debonder: 15 parts; The adhesion promoter: 5 parts; The stability aid: 0.5 parts.

[0055] The heterocyclic modified polyurethane acrylate prepolymer is prepared by the following method: A1, under nitrogen protection, benzimidazole diol and isophorone diisocyanate are added to a reactor, then dibutyltin dilaurate and butanone are added, and the mixture is reacted at 78°C for 2 h to obtain an intermediate; the benzimidazole diol is 1H-benzimidazole-4,7-diol; A2, hydroxyethyl acrylate is added to the intermediate and reacted at 62°C for 3 h to obtain the heterocyclic modified polyurethane acrylate prepolymer.

[0056] In the preparation of the heterocyclic modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:2.2:2.2; The mass of dibutyltin dilaurate is 0.2% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate; The mass of butanone is 50% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0057] The alkali-resistant active diluent is a mixture of perfluorohexyl ethyl acrylate and acryloyloxyethyl benzoxazole; in the alkali-resistant active diluent, the weight ratio of perfluorohexyl ethyl acrylate to acryloyloxyethyl benzoxazole is 4:1.

[0058] The photoinitiator is a mixture of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and bis(4-tert-butylphenyl) iodonium hexafluorophosphate. In the photoinitiator, the weight ratio of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and bis(4-tert-butylphenyl) iodonium hexafluorophosphate is 6:1.

[0059] The photo-thermal dual-responsive debonder is a selenium-containing polyurethane of PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond; the adhesion promoter is γ-glycidyl ether oxypropyl trimethoxysilane; and the stability aid is β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate (antioxidant 1076).

[0060] The preparation method of the UV alkali-resistant glue for UTG glass comprises the following steps: S1, mixing the heterocyclic modified polyurethane acrylate prepolymer and the alkali-resistant active diluent at 52°C for 0.5h to obtain a mixture I; S2, adding a photoinitiator, a photo-thermal dual-responsive debonder and a stability aid to the mixture I of S1 and mixing for 1h to obtain a mixture II S3, defoaming the mixture II under a vacuum degree of-0.1MPa for 10min to obtain the UV alkali-resistant glue.

[0061] Example 4

[0062] A UV alkali-resistant glue for UTG glass, other features being the same as those of Example 1, differs in that: comprising a heterocyclic modified polyurethane acrylate prepolymer, an alkali-resistant active diluent, a photoinitiator, a photo-thermal dual-responsive debonder, an adhesion promoter and a stability aid; The heterocyclic modified polyurethane acrylate prepolymer is synthesized by using a nitrogen-containing heterocyclic diol, a diisocyanate-containing and a hydroxyl-containing acrylate; In the UV alkali-resistant glue, in terms of weight parts: heterocyclic modified polyurethane acrylate prepolymer: 40 parts; alkali-resistant active diluent: 30 parts; photoinitiator: 5 parts; photo-thermal dual-responsive debonder: 10 parts; adhesion promoter: 3 parts; stability aid: 1 part.

[0063] The preparation method of the heterocyclic modified polyurethane acrylate prepolymer is as follows: A1, under the protection of nitrogen, benzimidazole diol and isophorone diisocyanate are added into a reactor, then dibutyltin dilaurate and butanone are added, and the reaction is carried out at 75°C for 3h to obtain an intermediate; the benzimidazole diol is 1H-benzimidazole-4,7-diol; A2, hydroxyethyl acrylate is added into the intermediate to react, and the reaction is carried out at 60°C for 4h to obtain the heterocycle-modified polyurethane acrylate prepolymer.

[0064] In the preparation of the heterocycle-modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:2.0:2.0; The mass of dibutyltin dilaurate is 0.1% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate; The mass of butanone is 60% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0065] The alkali-resistant active diluent is a mixture of perfluorohexylethyl acrylate and acryloyloxyethyl benzoxazole; in the alkali-resistant active diluent, the weight ratio of the perfluorohexylethyl acrylate and the acryloyloxyethyl benzoxazole is 2.75:1.

[0066] The photoinitiator is a mixture of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and bis(4-tert-butylphenyl) iodonium hexafluorophosphate. In the photoinitiator, the weight ratio of the 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide TPO and the bis(4-tert-butylphenyl) iodonium hexafluorophosphate is 4:1.

[0067] The photo-thermal dual-responsive debonder is a selenium-containing polyurethane of PEG-PUSeSe-PEG triblock polyurethane containing diselenium bond; the adhesion promoter is γ-glycidyl ether oxypropyl trimethoxysilane; and the stability aid is β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate (antioxidant 1076).

[0068] The preparation method of the UV alkali-resistant glue for UTG glass comprises the following steps: S1, the heterocycle-modified polyurethane acrylate prepolymer and the alkali-resistant active diluent are mixed at 50°C for 0.6h to obtain a mixture I; S2, the photoinitiator, the photo-thermal dual-responsive debonder and the stability aid are added into the mixture I of S1, and then mixed for 2h to obtain a mixture II S3, the mixture II is degassed at a vacuum degree of -0.1MPa for 30min to obtain the UV alkali-resistant glue.

[0069] Comparative Example 1

[0070] A UV alkali-resistant glue for UTG glass, other features being the same as Example 4, except that in the UV alkali-resistant glue, by weight parts: heterocyclic modified polyurethane acrylate prepolymer: 20 parts; alkali-resistant active diluent: 50 parts; photoinitiator: 5 parts; light-heat dual-responsive debonder: 10 parts; adhesion promoter: 3 parts; stability aid: 1 part.

[0071] The preparation method of the UV alkali-resistant glue for UTG glass is the same as Example 4.

[0072] Comparative Example 2

[0073] A UV alkali-resistant glue for UTG glass, other features being the same as Example 4, except that in the UV alkali-resistant glue, by weight parts: heterocyclic modified polyurethane acrylate prepolymer: 100 parts; alkali-resistant active diluent: 10 parts; photoinitiator: 5 parts; light-heat dual-responsive debonder: 10 parts; adhesion promoter: 3 parts; stability aid: 1 part.

[0074] The preparation method of the UV alkali-resistant glue for UTG glass is the same as Example 4.

[0075] Comparative Example 3

[0076] A UV alkali-resistant glue for UTG glass, other features being the same as Example 4, except that in the UV alkali-resistant glue, by weight parts: heterocyclic modified polyurethane acrylate prepolymer: 40 parts; alkali-resistant active diluent: 30 parts; photoinitiator: 5 parts; light-heat dual-responsive debonder: 20 parts; adhesion promoter: 3 parts; stability aid: 1 part.

[0077] The preparation method of the UV alkali-resistant glue for UTG glass is the same as Example 4.

[0078] Comparative Example 4

[0079] A UV alkali-resistant glue for UTG glass, other features are the same as example 4, the difference is that in the UV alkali-resistant glue, by weight: heterocyclic modified polyurethane acrylate prepolymer: 40 parts; alkali-resistant active diluent: 30 parts; photoinitiator: 5 parts; light-thermal dual-responsive debonder: 40 parts; adhesion promoter: 3 parts; stability aid: 1 part.

[0080] The preparation method of the UV alkali-resistant glue for UTG glass is the same as example 4.

[0081] Comparative example 5

[0082] A UV alkali-resistant glue for UTG glass, other features are the same as example 4, the difference is that in the preparation of the heterocyclic modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 1:3:3; The mass of dibutyltin dilaurate is 0.5% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0083] The preparation method of the UV alkali-resistant glue for UTG glass is the same as example 4.

[0084] Comparative example 6

[0085] A UV alkali-resistant glue for UTG glass, other features are the same as example 4, the difference is that in the preparation of the heterocyclic modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate is 2:1:1; The mass of dibutyltin dilaurate is 0.01% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

[0086] The preparation method of the UV alkali-resistant glue for UTG glass is the same as example 4.

[0087] Effect example

[0088] 1. Curing time and average visible light transparency after curing

[0089] Under the same conditions, the UV alkali-resistant glue obtained by Examples 2 to 4 and the UV alkali-resistant glue obtained by Comparative Examples 1 to 6 were coated on the surface of UTG glass, the coating thickness was 40 μm, the curing was performed by using a UV LED light source with a wavelength of 365 nm, the energy density was 1500 mJ / cm2, and the curing time was recorded; after curing, the visible light transparency was tested according to the standard GB / T 2410-2008 “Determination of transparency and haze of transparent plastics”, and Table 1 was obtained.

[0090] Table 1, curing time of UV alkali-resistant glue

[0091] As can be seen from Table 1, Example 4 of the present application performs best, with a curing time of only 3 s and a visible light transparency of 96.1%; the curing times of Examples 2 and 3 are 6 s and 10 s respectively, and the transparencies are both ≥95.6%, both of which meet the core requirements of rapid curing and transparency >95%.

[0092] 2, peel strength and tackiness reduction rate

[0093] Under the same conditions, the UV alkali-resistant glue obtained by Examples 2 to 4 and the UV alkali-resistant glue obtained by Comparative Examples 1 to 6 were coated on the surface of UTG glass, the coating thickness was 40 μm, the curing was performed by using a UV LED light source with a wavelength of 365 nm, the energy density was 1500 mJ / cm2, and the curing time was recorded; after curing, the visible light transparency was tested according to the standard GB / T 2410-2008 “Determination of transparency and haze of transparent plastics”, and Table 1 was obtained.

[0094] Table 2, peel strength and tackiness reduction rate of UV alkali-resistant glue

[0095] As can be seen from Table 2, the initial peel strength of Examples 2-4 is 4.5 N / 25 mm-4.8 N / 25 mm, which can meet the temporary fixing requirements of UTG glass lamination, and the peel strength is significantly reduced to less than 0.3 N / 25 mm after UV or heat treatment, and the tackiness reduction rate is more than 93%, realizing easy removal without residual glue.

[0096] 3, alkali resistance

[0097] Under the same conditions, the UV alkali-resistant glue obtained by Examples 2 to 4 and the UV alkali-resistant glue obtained by Comparative Examples 1 to 6 were coated on the surface of UTG glass, the coating thickness was 40 μm, the curing was performed by using a UV LED light source with a wavelength of 365 nm, the energy density was 1500 mJ / cm2, and the curing time was recorded; after curing, the visible light transparency was tested according to the standard GB / T 2410-2008 “Determination of transparency and haze of transparent plastics”, and Table 1 was obtained. ​

[0098] Table 3, alkali resistance of UV alkali-resistant glue

[0099] As can be seen from Table 3, the UV alkali-resistant glue of the present application can maintain structural integrity after soaking in 400°C molten alkali salt for 4 hours, and the mass change rate is less than 1%, showing excellent resistance to strong alkali.

[0100] In summary, it is proved that the UV alkali-resistant glue of the present application contains urea group, ester group, acrylic ester group and benzimidazole nitrogen-containing heterocyclic structure in the heterocyclic modified polyurethane acrylate prepolymer, which can form coordination bond with alkali molecules, reducing the attack of alkali on ester bond, so that it can maintain structural integrity after soaking in 400°C molten alkali salt for 4 hours. The initial peel strength of the UV alkali-resistant glue of the present application can reach 4.5N / 25mm-4.8N / 25mm, and the peel strength after debonding decreases to less than 0.3N / 25mm, meeting the dual requirements of fixing force and easy separability in the processing of UTG glass. The glue of the present application has fast curing speed, high transparency after curing, is convenient for laser cutting positioning and alignment mark identification, and has certain flexibility, which can adapt to the slight deformation of UTG glass in the processing. The UV alkali-resistant glue can be easily removed in warm water, and no residue is left.

[0101] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A UV-resistant alkali-resistant adhesive for UTG glass, characterized in that: Including heterocyclic modified polyurethane acrylate prepolymers, alkali-resistant reactive diluents, photoinitiators, photothermal dual-response depolymerizing agents, adhesion promoters, and stabilizing agents; The heterocyclic modified polyurethane acrylate prepolymer was synthesized by nitrogen-containing heterocyclic diols, diisocyanates, and hydroxyl-containing acrylates. In the UV-resistant alkali-resistant adhesive, by weight: Heterocyclic modified polyurethane acrylate prepolymer: 30 parts to 50 parts; Alkali-resistant reactive diluent: 20 to 40 parts; Photoinitiator: 3 to 8 parts; Photothermal dual-response degumming agent: 5 parts to 15 parts; Adhesion promoter: 1 to 5 parts; Stabilizing agent: 0.5 to 2 parts.

2. The UV alkali-resistant adhesive for UTG glass according to claim 1, characterized in that: In the UV-resistant alkali-resistant adhesive, by weight: Heterocyclic modified polyurethane acrylate prepolymer: 40 parts; Alkali-resistant reactive diluent: 30 parts; Photoinitiator: 5 parts; Photothermal dual-response degumming agent: 10 parts; Adhesion promoter: 3 parts; Stabilizing agent: 1 part.

3. The UV alkali-resistant adhesive for UTG glass according to claim 1 or 2, characterized in that, The preparation method of the heterocyclic modified polyurethane acrylate prepolymer is as follows: A1. Under nitrogen protection, benzimidazole diol and isophorone diisocyanate were added to the reactor, followed by dibutyltin dilaurate and butanone. The mixture was reacted at 73°C to 78°C for 2 to 4 hours to obtain the intermediate. A2. Add hydroxyethyl acrylate to the intermediate and react at 58°C to 62°C for 3 to 6 hours to obtain the heterocyclic modified polyurethane acrylate prepolymer.

4. The UV alkali-resistant adhesive for UTG glass according to claim 3, characterized in that: In the preparation of the heterocyclic modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate is 1:(1.8–2.2):(1.8–2.2). The mass of dibutyltin dilaurate is 0.05% to 0.2% of the total mass of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate. The mass of methyl ethyl ketone is 50% to 80% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

5. The UV alkali-resistant adhesive for UTG glass according to claim 4, characterized in that: In the preparation of the heterocyclic modified polyurethane acrylate prepolymer: The molar ratio of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate is 1:2:2; The mass of dibutyltin dilaurate is 0.1% of the total mass of benzimidazole diol, isophorone diisocyanate, and hydroxyethyl acrylate; The mass of methyl ethyl ketone is 60% of the total mass of benzimidazole diol, isophorone diisocyanate and hydroxyethyl acrylate.

6. The UV alkali-resistant adhesive for UTG glass according to any one of claims 1 to 5, characterized in that: The alkali-resistant reactive diluent is a mixture of fluorinated acrylate monomers and benzoxazole monomers; The photoinitiator is a mixture of free radical photoinitiators and cationic photoinitiators.

7. The UV alkali-resistant adhesive for UTG glass according to claim 2, characterized in that: In the alkali-resistant reactive diluent, the weight ratio of the fluorinated acrylate monomer to the benzoxazole monomer is (2-4):1; In the photoinitiator, the weight ratio of the free radical photoinitiator to the cationic photoinitiator is (2-6):(1-2); The photothermal dual-responsive degumming agent is a selenium-containing polyurethane of the PEG-PUSeSe-PEG triblock polyurethane containing diselenobonds.

8. The UV alkali-resistant adhesive for UTG glass according to claim 7, characterized in that: The fluorinated acrylate monomer is perfluorohexylethyl acrylate; The benzoxazole monomer is acryloyloxyethylbenzoxazole; The free radical photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; The cationic photoinitiator is bis(4-tert-butylphenyl)iodonium hexafluorophosphate; The selenium-containing polyurethane is a PEG-PUSeSe-PEG triblock polyurethane containing diselenyl bonds; The adhesion promoter is γ-glycidoxypropyltrimethoxysilane; The stabilizing agent is β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester.

9. A method for preparing a UV alkali-resistant adhesive for UTG glass as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Mix heterocyclic modified polyurethane acrylate prepolymer and alkali-resistant reactive diluent to obtain mixture I; S2. Add a photoinitiator, a photothermal dual-response desiccant, and a stabilizing agent to mixture I in S1 and mix to obtain mixture II; S3. Mixture II is degassed under vacuum to obtain the UV-resistant alkali-resistant adhesive.

10. The method for preparing UV alkali-resistant adhesive for UTG glass according to claim 9, characterized in that, Includes the following steps: S1. Mix the heterocyclic modified polyurethane acrylate prepolymer and the alkali-resistant reactive diluent at 48°C to 52°C for 0.5 h to 1 h to obtain mixture I; S2. Add the photoinitiator, photothermal dual-response deflocculant, and stabilizing agent to mixture I of S1, and mix for 1 to 3 hours to obtain mixture II. S3. Mixture II is degassed under a vacuum of -0.1 MPa for 10 min to 60 min to obtain the UV alkali resistant adhesive.

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