Boron-containing organic silicon, optical adhesive, organic silicon OCA, and preparation method therefor and use thereof

Abstract

Disclosed herein are a boron-containing organic silicon, an optical adhesive, organic silicon OCA, and a preparation method therefor and the use thereof. The preparation raw materials of the boron-containing organic silicon comprise a combination of a silanol, a siloxane monomer and a boric acid compound. In the preparation raw materials of the boron-containing organic silicon, the ratio of the total molar weight of hydroxyl to the total molar weight of alkoxy is (0.8-1.1):1, and the ratio of the total molar weight of B to the total molar weight of Si is 1:(5-11.5). By means of the design of the preparation raw materials of the boron-containing organic silicon provided in the invention, the compatibility between the boron-containing organic silicon and an organic silicon material in an optical adhesive is good, the tackifying effect on the optical adhesive is excellent, and thus the optical adhesive has excellent low-temperature resistance and high-temperature and high-humidity resistance.

Description

A boron-containing organosilicon, an optical adhesive, organosilicon OCA, its preparation method and application Technical Field

[0001] This application relates to the field of organosilicon encapsulation materials technology, such as a boron-containing organosilicon, optical adhesive, organosilicon OCA, its preparation method and application. Background Technology

[0002] OCA optical adhesive is a double-sided bonding tape made of substrate-free material with a release film layer on both the top and bottom layers. It belongs to the category of pressure-sensitive adhesives and is widely used in the optical display field, such as for bonding display modules, glass covers, and touch screens. It features high light transmittance and high bonding strength. Currently, OCA optical adhesives can be classified according to the material used, including acrylic OCA, silicone OCA, polyurethane OCA, and epoxy resin OCA. Compared to other types of OCA, silicone OCA has superior weather resistance, yellowing resistance, aging resistance, and ease of repair. However, silicone OCA generally suffers from poor initial tack, with its peel strength being much lower than other resins. Due to the low initial tack, it cannot be transferred immediately after bonding, leading to low production efficiency and the risk of component detachment during display transfer, resulting in losses.

[0003] Currently, adding tackifiers to silicone materials is a common method to solve the problem of adhesion between materials and substrates. However, in actual production, conventional tackifiers have poor compatibility with silicone materials and do not have a significant tackifying effect on the substrate. Under certain temperature and humidity conditions, the adhesion decreases significantly, leading to severe separation between the silicone resin material and the substrate.

[0004] CN102775611A discloses a tackifier and its production method, which is a pale yellow liquid organosilicon tackifier obtained by reacting hydroxyl silicone oil, γ-glycidyl ether oxypropyltrimethoxysilane and γ-methylpropionyl oxypropyltrimethoxysilane under the catalysis of organotin; however, the organotin catalyst in the tackifier is difficult to completely remove, which seriously affects the normal curing of addition-type liquid silicone rubber.

[0005] CN104774333A discloses a tackifier for addition-type silicone oil prepared by a catalytic reaction of vinyl hydroxy silicone oil, glycidyl ether alkoxysilane and titanate. However, titanate, especially titanate complexes, are generally yellow or even dark brown. The resulting tackifier is colored, which may have an adverse effect on the preparation of colorless or light-colored addition-type silicone adhesives.

[0006] CN109824899A discloses a thickener for addition-type silica gel produced by reacting epoxy dialkoxysilane, boric acid and vinyl dialkoxysilane under the catalysis of an alkaline anion exchange resin. However, the ion exchange resin may break during the reaction, and there is a risk of incomplete filtration when removing the catalyst by vacuum filtration in the subsequent process.

[0007] Therefore, there is an urgent need to design a tackifier that has good compatibility with organosilicon materials, excellent tackifying effect, and can improve the low-temperature resistance and high-temperature and high-humidity resistance of organosilicon OCA. Summary of the Invention

[0008] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0009] To address the shortcomings of existing technologies, this application provides a boron-containing organosilicon, an optical adhesive, an organosilicon OCA, its preparation method, and its application. Through the design of the raw materials, the boron-containing organosilicon exhibits good compatibility with the organosilicon material in the optical adhesive, resulting in excellent tackifying effect on the optical adhesive and giving it excellent low-temperature resistance and high-temperature and high-humidity resistance.

[0010] To achieve this objective, the following technical solution is adopted in this application:

[0011] In a first aspect, embodiments of this application provide a boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include a combination of silanols, siloxane monomers and boric acid compounds; in the raw materials for preparing the boron-containing organosilicon, the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups is (0.8-1.1):1, and the ratio of the total molar amount of B elements to the total molar amount of Si elements is 1:(5-11.5).

[0012] This application embodiment forms a boron-containing organosilicon polymer macromolecule, namely boron-containing organosilicon, through siloxane monomers, silanols, and boric acid compounds. The target product structure is more controllable and has no by-products. Since the boron atom has electron vacancies, it can act as an acceptor of unpaired electrons on the polysiloxane chain segment or the substrate surface, forming electron bridges between adjacent molecules, thereby forming weak bond links. Furthermore, the boron-containing organosilicon provided in this application embodiment contains Si-OB bonds in its molecular structure, which can, to a certain extent, enable physical cross-linking between the organosilicon OCA and the substrate. Therefore, adding the boron-containing organosilicon provided in this application embodiment to optical adhesives allows the optical adhesives to have good adhesion to glass, inks, or polarizers after curing. In addition, the introduction of boron can disrupt the regularity of the chain segments, thereby lowering the glass transition temperature (Tg) of the boron-containing organosilicon and improving the low-temperature resistance of the organosilicon OCA.

[0013] The boron-containing organosilicon preparation raw materials provided in this application embodiment are catalyst-free, which to a certain extent avoids the adverse effects of catalyst residue on the color or curing of optical adhesives. This application embodiment effectively regulates the structure of boron-containing organosilicon by introducing silanol, controlling the molar ratio of hydroxyl to alkoxy groups in the reaction system, promoting a complete condensation reaction, and improving the yield of boron-containing organosilicon. Simultaneously, it reduces the residual amount of alkoxy groups in the boron-containing organosilicon, preventing alkoxy hydrolysis during subsequent use or storage, which could lead to fogging and failure to meet the requirements of optical adhesives. Furthermore, compared to fatty alcohols, silanols have better compatibility with siloxane monomers and boric acid compounds, do not separate after feeding, and react more thoroughly. Compared to hydroxyl silicone oils, silanols have higher reactivity and can form a denser network structure, effectively enhancing the hydrolysis resistance of boron-containing organosilicon to a certain extent.

[0014] In this embodiment of the application, "the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups in the raw materials for preparing boron-containing organosilicon is (0.8-1.1):1" means that the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups in all the raw materials for preparing boron-containing organosilicon is (0.8-1.1):1; "the ratio of the total molar amount of B elements to the total molar amount of Si elements is 1:(5-11.5)" means that the ratio of the total molar amount of B elements to the total molar amount of Si elements in all the raw materials for preparing boron-containing organosilicon is 1:(5-11.5).

[0015] In the raw materials for preparing boron-containing organosilicon, the hydroxyl groups are derived from the silanol hydroxyl groups and the boron hydroxyl groups of boric acid compounds. The ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups is (0.8-1.1):1, for example, it can be 0.82:1, 0.84:1, 0.86:1, 0.88:1, 0.9:1, 0.92:1, 0.94:1, 0.96:1, 0.98:1, 1:1, 1.02:1, 1.04:1, 1.06:1 or 1.08:1, etc.

[0016] In the raw materials for preparing boron-containing organosilicon, the ratio of the total molar amount of B element to the total molar amount of Si element is 1:(5-11.5), for example, it can be 1:5.1, 1:5.2, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, 1:10.5 or 1:11, etc.

[0017] In this embodiment, by controlling the molar ratio of boron (B) to silicon (Si) in the raw materials for preparing boron-containing organosilicon within a suitable range, boron-containing organosilicon with good adhesion promotion and no significant change in hydrolysis resistance can be obtained. If the molar ratio of B to Si is too large, the adhesive performance of the optical adhesive is improved, but the hydrolysis resistance deteriorates. This is because the BO-Si bond is more sensitive to hydrolysis than the Si-O-Si bond and is more prone to hydrolytic breakage. If the molar ratio of B to Si is too small, the improvement in the adhesive performance of organosilicon OCA is not significant.

[0018] The following are preferred technical solutions of this application, but are not intended to limit the technical solutions provided in this application. The purpose and beneficial effects of this application can be better achieved through the following preferred technical solutions.

[0019] As a preferred technical solution, the general formula of the silanol is R 11 4-a Si(OH) a Among them, R 11 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl or C3-C8 cyclic hydrocarbon groups; a is 2 or 3.

[0020] In the embodiments of this application, "each independently" means that when there are multiple subjects, they may be the same or different from each other. The same descriptions used below have the same meaning.

[0021] Preferably, the silanol includes any one or a combination of at least two of dimethylsilanediol, methylethylsilanediol, methylphenylsilanediol, methylsilanetriol, or phenylsilanetriol.

[0022] Preferably, the general formula of the siloxane monomer is R 12 4-b Si(OR 13 ) b Among them, R 12 Each is independently selected from any one of C2-C6 unsaturated hydrocarbon groups, C1-C5 straight-chain or branched alkyl groups; R 13 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl groups; b is selected from an integer of 1-3, optionally 2 or 3.

[0023] In this embodiment of the application, C1-C5 can each be independently C2, C3 or C4, etc.

[0024] Each of C3-C8 can independently be C4, C5, C6, or C7, etc.

[0025] The C1-C5 straight-chain or branched alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, or neopentyl.

[0026] The C3-C8 cycloalkyl group includes any one of C3-C8 cycloalkyl or phenyl; the C3-C8 cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

[0027] The C2-C6 unsaturated hydrocarbon group includes any one of the C2-C6 alkenyl groups, including but not limited to vinyl, propenyl, or butenyl groups.

[0028] Preferably, the siloxane monomer comprises a first siloxane monomer, a second siloxane monomer, and optionally a third siloxane monomer; the first siloxane monomer has the general formula R. A1 2Si(OR A2 )2; the general formula of the second siloxane monomer is R B1 Si(OR B2 )3; The general formula of the third siloxane monomer is R C1 3SiOR C2 Among them, R A1 R B1 and R C1 Each is independently selected from any one of C2-C6 unsaturated hydrocarbon groups or C1-C5 straight-chain or branched alkyl groups; R A2 R B2 and R C2 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl groups.

[0029] Preferably, the first siloxane monomer comprises any one or a combination of at least two of methylvinyldimethoxysilane, dimethyldimethoxysilane, or dimethyldiethoxysilane.

[0030] Preferably, the second siloxane monomer comprises methyltrimethoxysilane and / or methyltriethoxysilane.

[0031] Preferably, the third siloxane monomer comprises trimethylmethoxysilane.

[0032] Preferably, the boric acid compound includes any one or a combination of at least two of boric acid, phenylboronic acid, or tetrahydroxyboronic acid.

[0033] Preferably, the molar ratio of the hydroxyl group in the boric acid compound to the hydroxyl group in the silanol is 1:(1-7), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5 or 1:6, etc.

[0034] Preferably, in the boron-containing organosilicon preparation raw materials, the ratio of the total molar amount of B element to the total molar amount of Si element is 1:(6.5-11.5) (e.g., 1:6.6, 1:6.8, 1:7, 1:7.2, 1:7.4, 1:7.6, 1:7.8, 1:8.2, 1:8.6, 1:9.2, 1:9.4, 1:10.2, 1:10.6, 1:11.2 or 1:11.4, etc.), and optionally, it is 1:(7-8.5) (e.g., 1:7.1, 1:7.3, 1:7.7, 1:7.9, 1:8.1, 1:8.3 or 1:8.4, etc.).

[0035] In the embodiments of this application, when the molar ratio of B to Si in the raw materials for preparing boron-containing organosilicon is 1:(7-8.5), the hydrolysis resistance of the boron-containing organosilicon can be optimized, and the adhesion performance of organosilicon OCA can be improved.

[0036] Preferably, the raw materials for preparing the boron-containing organosilicon also include a solvent.

[0037] Preferably, the solvent includes any one or a combination of at least two of N,N-dimethylformamide, dimethyl sulfoxide, methanol, acetonitrile, isopropanol, 1,4-dioxane, or cyclohexanone.

[0038] Preferably, the solvent accounts for 25-40% of the total mass of the silanol, siloxane monomer, and boric acid compound, which is 100% of the total mass. For example, it can be 25.5%, 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, 30.5%, 31%, 31.5%, 32%, 32.5%, 33%, 33.5%, 34%, 34.5%, 35%, 35.5%, 36%, 36.5%, 37%, 37.5%, 38%, or 39%, etc.

[0039] Secondly, embodiments of this application provide a method for preparing boron-containing organosilicon as described in the first aspect, the method comprising:

[0040] The boron-containing organosilicon is obtained by reacting silanols, siloxane monomers, and boric acid compounds.

[0041] Boron-containing organosilicones were prepared using the preparation method provided in the embodiments of this application, with high yield and no by-products, and the yield was 72-87%.

[0042] Preferably, the reaction temperature is 80-140℃, for example, it can be 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃ or 135℃, etc.

[0043] Preferably, the reaction time is 3-7 hours, for example, 3.2 hours, 3.5 hours, 3.8 hours, 4 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5 hours, 5.2 hours, 5.5 hours, 5.8 hours, 6 hours, 6.2 hours, 6.5 hours, or 6.8 hours.

[0044] Preferably, the reaction is carried out in the presence of a solvent.

[0045] Preferably, the reaction further includes a step of vacuum distillation after completion; the solvent in the reaction system is removed by vacuum distillation.

[0046] Thirdly, this application provides an application of boron-containing organosilicon as described in the first aspect, wherein the boron-containing organosilicon is used as a tackifier in optical adhesives.

[0047] Fourthly, this application provides an optical adhesive. The raw materials for preparing the optical adhesive, by weight, include:

[0048] The vinyl silicone resin is 10-30 parts by weight, for example, 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight or 28 parts by weight, etc.

[0049] The vinyl silicone oil is 30-50 parts by weight, for example, 32 parts by weight, 34 parts by weight, 36 parts by weight, 38 parts by weight, 40 parts by weight, 42 parts by weight, 44 parts by weight, 46 parts by weight or 48 parts by weight, etc.

[0050] The hydrogen-containing silicone oil is 5-20 parts by weight, for example, 6 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 14 parts by weight, 16 parts by weight or 18 parts by weight, etc.

[0051] The hydrogen-containing silicone resin is 10-30 parts by weight, for example, it can be 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight or 28 parts by weight, etc.

[0052] The catalyst is 0.01-0.5 parts by weight, for example, it can be 0.05 parts by weight, 0.1 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.25 parts by weight, 0.3 parts by weight, 0.35 parts by weight, 0.4 parts by weight or 0.45 parts by weight, etc.

[0053] The boron-containing organosilicon is 0.1-15 parts by weight, for example, it can be 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, 6.5 parts by weight, 7 parts by weight, 7.5 parts by weight, 8 parts by weight, 8.5 parts by weight, 9 parts by weight, 9.5 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, or 14 parts by weight, etc.

[0054] Preferably, the vinyl silicone resin includes any one or a combination of at least two of vinyl MQ silicone resin, vinyl MDT silicone resin, vinyl MTQ silicone resin, or vinyl DT silicone resin.

[0055] Preferably, the viscosity of the vinyl silicone resin at 25°C is 5000-50000 mPa·s, for example, it can be 5500 mPa·s, 6000 mPa·s, 6500 mPa·s, 7000 mPa·s, 7500 mPa·s, 8000 mPa·s, 8500 mPa·s, 9000 mPa·s, 9500 mPa·s, 10000 mPa·s, 15000 mPa·s, 20000 mPa·s, 25000 mPa·s, 30000 mPa·s, 35000 mPa·s, 40000 mPa·s, or 45000 mPa·s, etc.

[0056] Preferably, the vinyl content of the vinyl silicone resin is 0.3-1.0 mmol / g, for example, it can be 0.35 mmol / g, 0.4 mmol / g, 0.45 mmol / g, 0.5 mmol / g, 0.55 mmol / g, 0.6 mmol / g, 0.65 mmol / g, 0.7 mmol / g, 0.75 mmol / g, 0.8 mmol / g, 0.85 mmol / g, 0.9 mmol / g or 0.95 mmol / g, etc.

[0057] Preferably, the vinyl silicone oil includes any one or a combination of at least two of the following: silicone oil with vinyl ends, silicone oil with vinyl side groups, or silicone oil with vinyl ends and vinyl side groups.

[0058] Preferably, the viscosity of the vinyl silicone oil at 25°C is 100-20000 mPa·s, for example, it can be 500 mPa·s, 1000 mPa·s, 1500 mPa·s, 2000 mPa·s, 2500 mPa·s, 3000 mPa·s, 3500 mPa·s, 4000 mPa·s, 4500 mPa·s, 5000 mPa·s, 5500 mPa·s, 6000 mPa·s, 6500 mPa·s, 7000 mPa·s, 7500 mPa·s, 8000 mPa·s, 8500 mPa·s, 9000 mPa·s, 9500 mPa·s, 10000 mPa·s, 15000 mPa·s, or 20000 mPa·s.

[0059] Preferably, the vinyl content of the vinyl silicone oil is 0.1-0.75 mmol / g, for example, it can be 0.15 mmol / g, 0.2 mmol / g, 0.25 mmol / g, 0.3 mmol / g, 0.35 mmol / g, 0.4 mmol / g, 0.45 mmol / g, 0.5 mmol / g, 0.55 mmol / g, 0.6 mmol / g, 0.65 mmol / g, or 0.7 mmol / g, etc.

[0060] Preferably, the general formula of the hydrogen-containing silicone resin is (R 21 R 22 R 23 SiO 1 / 2 ) x (R 24 R 25 SiO 2 / 2 ) y (R 26 SiO 3 / 2 ) z Among them, R 21 R 22 R 23 R 24 R 25 and R 26 Each is independently selected from any one of hydrogen atoms or C1-C5 straight-chain or branched alkyl groups, and R 21 R 22 R 23 R 24 R 25 and R 26At least one of them is a hydrogen atom; x:y:z is the molar ratio of each unit, and x:y:z = 1:(0.2-0.3):(2-3), for example, it can be 1:0.21:2.1, 1:0.22:2.2, 1:0.23:2.3, 1:0.24:2.4, 1:0.25:2.5, 1:0.26:2.6, 1:0.27:2.7, 1:0.28:2.8 or 1:0.29:2.9, etc.

[0061] Preferably, the viscosity of the hydrogen-containing silicone resin at 25°C is 10,000-40,000 mPa·s, for example, it can be 12,000 mPa·s, 14,000 mPa·s, 16,000 mPa·s, 18,000 mPa·s, 20,000 mPa·s, 22,000 mPa·s, 24,000 mPa·s, 26,000 mPa·s, 28,000 mPa·s, 30,000 mPa·s, 32,000 mPa·s, 34,000 mPa·s, 36,000 mPa·s, or 38,000 mPa·s, etc.

[0062] Preferably, the hydroxyl group content of the hydrogen-containing silicone resin is 0.1-1.2 mmol / g, for example, it can be 0.15 mmol / g, 0.2 mmol / g, 0.25 mmol / g, 0.3 mmol / g, 0.35 mmol / g, 0.4 mmol / g, 0.45 mmol / g, 0.5 mmol / g, 0.55 mmol / g, 0.6 mmol / g, 0.65 mmol / g, 0.7 mmol / g, 0.75 mmol / g, 0.8 mmol / g, 0.85 mmol / g, 0.9 mmol / g, 0.95 mmol / g, 1 mmol / g, 1.05 mmol / g, 1.1 mmol / g, or 1.15 mmol / g, etc.

[0063] Preferably, the general formula of the hydrogen-containing silicone oil is (R 31 R 32 R 33 SiO 1 / 2 ) p (R 34 R 35 SiO 2 / 2 ) m (R 36 R 37 SiO 2 / 2 ) n Among them, R 31 R 32 R 33 R 34 R 35 R 36 and R 37Each is independently selected from any one of hydrogen atoms or C1-C5 straight-chain or branched alkyl groups, and R 34 R 35 R 36 and R 37 At least one of them is a hydrogen atom; 1≤p≤2, 0≤m≤50 (e.g., 2, 5, 8, 10, 12, 15, 20, 25, 30, 35, 40 or 45, etc.), 0≤n≤50 (e.g., 2, 5, 8, 10, 12, 15, 20, 25, 30, 35, 40 or 45, etc.), and m and n are not both 0.

[0064] Preferably, the viscosity of the hydrogen-containing silicone oil at 25°C is 100-3000 mPa·s, for example, it can be 200 mPa·s, 400 mPa·s, 500 mPa·s, 600 mPa·s, 800 mPa·s, 1000 mPa·s, 1200 mPa·s, 1500 mPa·s, 1800 mPa·s, 2000 mPa·s, 2200 mPa·s, 2500 mPa·s, or 2800 mPa·s.

[0065] Preferably, the hydroxyl content of the hydrogen-containing silicone oil is 0.05-0.5 mmol / g, for example, it can be 0.1 mmol / g, 0.15 mmol / g, 0.2 mmol / g, 0.25 mmol / g, 0.3 mmol / g, 0.35 mmol / g, 0.4 mmol / g or 0.45 mmol / g, etc.

[0066] Preferably, in the raw materials for preparing the optical adhesive, the ratio of the total molar amount of vinyl groups to the total molar amount of silane groups is (0.95-1.05):1, for example, it can be 0.96:1, 0.97:1, 0.98:1, 0.99:1, 1:1, 1.01:1, 1.02:1, 1.03:1 or 1.04:1, etc.

[0067] Preferably, the catalyst comprises any one or a combination of at least two of chloroplatinic acid, Karstedt platinum catalyst, or Willing platinum catalyst.

[0068] Preferably, the raw materials for preparing the optical adhesive further include 0.2-0.5 parts by weight of inhibitor, such as 0.22 parts by weight, 0.24 parts by weight, 0.26 parts by weight, 0.28 parts by weight, 0.3 parts by weight, 0.32 parts by weight, 0.34 parts by weight, 0.36 parts by weight, 0.38 parts by weight, 0.4 parts by weight, 0.42 parts by weight, 0.44 parts by weight, 0.46 parts by weight, or 0.48 parts by weight.

[0069] Preferably, the inhibitor comprises an alcohol compound containing an unsaturated group and / or a siloxane containing at least two vinyl groups.

[0070] Preferably, the alcohol compound containing unsaturated groups includes any one of the alcohol compounds containing carbon-carbon triple bonds.

[0071] Preferably, the inhibitor comprises any one or a combination of at least two of 1,4-butynediol, ethynylcyclohexanol, tetramethyltetravinylcyclotetrasiloxane, or 2-methyl-3-butyn-2-ol.

[0072] Fifthly, this application provides an organosilicon OCA, the organosilicon OCA comprising a first release film, an optical adhesive layer, and a second release film sequentially stacked; the optical adhesive layer is formed by curing an optical adhesive as described in the fourth aspect.

[0073] Preferably, the thickness of the optical adhesive layer is 50-500μm, for example, it can be 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm or 450μm, etc.

[0074] Preferably, the first release film and the second release film are each independently selected from either a non-silicone release film or a fluorine release film.

[0075] Preferably, the thickness of the first release film and the second release film are each independently 20-2000 μm, for example, they can be 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 400 μm, 600 μm, 800 μm, 1000 μm, 1200 μm, 1400 μm, 1600 μm or 1800 μm, etc.

[0076] Preferably, the release force difference between the first release film and the second release film is 15-20 gf / 25 mm, for example, it can be 15.5 gf / 25 mm, 16 gf / 25 mm, 16.5 gf / 25 mm, 17 gf / 25 mm, 17.5 gf / 25 mm, 18 gf / 25 mm, 18.5 gf / 25 mm, 19 gf / 25 mm or 19.5 gf / 25 mm, etc.

[0077] In a sixth aspect, this application provides the use of an optical adhesive as described in the fourth aspect or an organosilicon OCA as described in the fifth aspect in display bonding.

[0078] Compared with the prior art, this application has the following beneficial effects:

[0079] (1) The boron-containing organosilicon provided in this application has a more controllable structure and no by-products through the design of the raw materials. It can be used as a tackifier in optical adhesives. It has good compatibility with organosilicon materials in optical adhesives and has excellent tackifying effect on optical adhesives. It can enable organosilicon OCA to have good initial bonding performance with glass, ink and polarizer at the same time, and can improve the low temperature resistance and high temperature and high humidity resistance of organosilicon OCA.

[0080] (2) Using the boron-containing organosilicon OCA provided in the embodiments of this application, the initial peel force of the ink is 5.358-11.323 N / 25 mm, and the peel force after 5 min is 15.837-22.385 N / 25 mm; the initial peel force of the glass is 5.354-11.997 N / 25 mm, and the peel force after 5 min is 15.625-22.315 N / 25 mm; the initial peel force of the polarizer is 5.035-9.591 N / 25 mm, and the peel force after 5 min is 16.325-22.516 N / 25 mm.

[0081] (3) The light transmittance of the boron-containing organosilicon OCA provided in the embodiments of this application is 91.35-92.91%, the glass transition temperature is -50 to -40℃, the initial haze is 0.11-0.18%, the haze after aging at 105℃ for 1000h is 0.10-0.17%, and the haze after aging at 85℃ / 85%RH for 1000h is 0.26-0.29%.

[0082] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood. Attached Figure Description

[0083] Figure 1 is the infrared spectrum of the boron-containing organosilicon provided in Example 2;

[0084] Figure 2 is a gel permeation chromatogram of boron-containing organosilicon provided in Example 2. Detailed Implementation

[0085] The technical solution of this application will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of this application and should not be construed as specific limitations thereof.

[0086] Example 1

[0087] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0088] The method for preparing the boron-containing organosilicon includes:

[0089] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 46.37 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 173 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1:1, and the molar ratio of boron to silicon was 1:5.7. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 74%. No abnormalities were observed after standing at room temperature for 2 months.

[0090] Example 2

[0091] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0092] The method for preparing the boron-containing organosilicon includes:

[0093] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 38.64 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 170 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.93:1, and the molar ratio of boron to silicon was 1:6.8. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 h. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 85%. No abnormalities were observed after standing at room temperature for 2 months.

[0094] The boron-containing organosilicon was tested using a Bruker Fourier transform infrared spectrometer (model: ALPHA) from Germany. The test results are shown in Figure 1, which is the infrared spectrum of the boron-containing organosilicon provided in Example 2. As can be seen from Figure 1, at 1340 cm⁻¹... -1 A distinct Si-OB characteristic peak appears at this location;

[0095] The sample was injected with tetrahydrofuran as the mobile phase (concentration 0.02 g / mL) at a flow rate of 10 μL and a flow rate of 1 mL / min. A standard curve was prepared using polystyrene as the standard sample. The test was performed at 40 °C using a Waters 2414 differential refractive index detector. The test results are shown in Figure 2, which is the gel permeation chromatogram of the boron-containing organosilicon provided in Example 2. As shown in Figure 2, Example 2 synthesized the boron-containing organosilicon with a number-average molecular weight of 18721 and a dispersive index of 1.36.

[0096] Example 3

[0097] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0098] The method for preparing the boron-containing organosilicon includes:

[0099] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 35.55 g of boric acid, 95.35 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 167 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.93:1, and the molar ratio of boron to silicon was 1:7.3. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 87%. No abnormalities were observed after standing at room temperature for 2 months.

[0100] Example 4

[0101] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0102] The method for preparing the boron-containing organosilicon includes:

[0103] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 30.91 g of boric acid, 85.14 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 162 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.93:1, and the molar ratio of boron to silicon was 1:8.25. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 h. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 87%. No abnormalities were observed after standing at room temperature for 2 months.

[0104] Example 5

[0105] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0106] The method for preparing the boron-containing organosilicon includes:

[0107] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 27.82 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 167 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.84:1, and the molar ratio of boron to silicon was 1:9.4. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 80%. No abnormalities were observed after standing at room temperature for 2 months.

[0108] Example 6

[0109] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0110] The method for preparing the boron-containing organosilicon includes:

[0111] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 23.19 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 140 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.8:1, and the molar ratio of boron to silicon was 1:11.3. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 h. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 72%. No abnormalities were observed after standing at room temperature for 2 months.

[0112] Comparative Example 1

[0113] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0114] The method for preparing the boron-containing organosilicon includes:

[0115] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 179.73 g of dimethylsilanediol, 46.37 g of boric acid, 102.17 g of methyltrimethoxysilane, 185.14 g of dimethyldimethoxysilane, and 150 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.15:1, and the molar ratio of boron to silicon was 1:5.7. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 h. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 67%. No abnormalities were observed after standing at room temperature for 2 months.

[0116] Comparative Example 2

[0117] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0118] The method for preparing the boron-containing organosilicon includes:

[0119] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 211.07 g of dimethylsilanediol, 24.11 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 160 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1:1, and the molar ratio of boron to silicon was 1:12.3. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 75%. No abnormalities were observed after standing at room temperature for 2 months.

[0120] Comparative Example 3

[0121] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0122] The method for preparing the boron-containing organosilicon includes:

[0123] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 71.10 g of boric acid, 238.39 g of methyltrimethoxysilane, 90.16 g of dimethyldimethoxysilane, and 187 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.03:1, and the molar ratio of boron to silicon was 1:3.7. After the feed was stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100 °C and reacted for 4 h. Subsequently, the oil temperature was raised to 160 °C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 67%. No abnormalities were observed after standing at room temperature for 2 months.

[0124] Comparative Example 4

[0125] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include dimethylsilanediol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0126] The method for preparing the boron-containing organosilicon includes:

[0127] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 161.30 g of dimethylsilanediol, 35.55 g of boric acid, 272.44 g of methyltrimethoxysilane, 54.10 g of dimethyldimethoxysilane, and 174 g of cyclohexanone were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.76:1, and the molar ratio of boron to silicon was 1:7.3. After the materials were stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100°C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160°C, and the solvent was removed by vacuum distillation to obtain a colorless and transparent liquid product with a yield of 64%. After being left at room temperature for 2 weeks, fogging occurred, which could not meet the optical performance requirements of optical adhesives.

[0128] Comparative Example 5

[0129] A boron-containing organosilicon, wherein the raw materials for preparing the boron-containing organosilicon include neopentyl glycol, methyltrimethoxysilane, dimethyldimethoxysilane, boric acid, and cyclohexanone;

[0130] The method for preparing the boron-containing organosilicon includes:

[0131] A dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. 222.50 g of neopentyl glycol, 22.73 g of boric acid, 102.17 g of methyltrimethoxysilane, 210.38 g of dimethyldimethoxysilane, and 178 g of cyclohexanone were added to the flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 0.93:1, and the molar ratio of boron to silicon was 1:6.8. After the materials were stirred evenly by mechanical stirring at room temperature, the oil bath was heated to 100°C and reacted for 4 hours. Subsequently, the oil temperature was raised to 160°C, and the solvent was removed by vacuum distillation, yielding a colorless and transparent liquid product with a yield of 65%. No abnormalities were observed after two months of storage.

[0132] The boron-containing organosilicon preparation method provided in this application is simple, requires no catalyst, and is colorless and transparent. After two months of storage, there are no adverse phenomena such as fogging or precipitation, and the yield is 72-87%. In Comparative Example 4, although colorless and transparent boron-containing organosilicon can be obtained due to the molar ratio of hydroxyl to alkoxy groups in the reaction system being 0.76:1, the residual alkoxy groups absorb moisture from the air and undergo hydrolysis, resulting in fogging and turbidity of the boron-containing organosilicon after 14 days of storage. The storage stability is poor, making it unsuitable for use in optical adhesives. In Comparative Example 5, fatty alcohols are used instead of silanols. Fatty alcohols have poor compatibility with siloxane monomers and boric acid compounds. After being added to the reaction vessel, the mixture becomes cloudy and foggy, indicating a low degree of reaction and a product yield of only 65%.

[0133] The sources of raw materials and equipment used in the following application examples and comparative examples are as follows:

[0134] (A) Vinyl silicone oil

[0135] (B) Vinyl silicone resin

[0136] (C) Hydrogen-containing silicone oil

[0137] (D) Hydrogen-containing silicone resin

[0138] The general formula is: (HMe2SiO) 1 / 2 ) x (HMeSiO 2 / 2 ) y (MeSiO 3 / 2 ) z , where Me is a methyl group.

[0139] (E) catalyst

[0140] (F) Inhibitors

[0141] Coating equipment

[0142] Application Example 1

[0143] An optical adhesive, wherein the raw materials for preparing the optical adhesive include 27 parts by weight of vinyl silicone resin B-1, 40 parts by weight of vinyl silicone oil A-1, 5 parts by weight of hydrogen-containing silicone oil C-1, 23 parts by weight of hydrogen-containing silicone resin D-1, 4.4 parts by weight of boron-containing organosilicon provided in Example 1, 0.1 parts by weight of catalyst E-1 and 0.5 parts by weight of inhibitor F-1;

[0144] The preparation method of the optical adhesive includes:

[0145] Vinyl silicone resin B-1, vinyl silicone oil A-1, hydrogen-containing silicone oil C-1, hydrogen-containing silicone resin D-1, boron-containing organosilicon provided in Example 1, catalyst E-1 and inhibitor F-1 are mixed, stirred evenly, and degassed under vacuum to obtain the optical adhesive.

[0146] The optical adhesive is used in the preparation of organosilicon OCA, and the specific method is as follows:

[0147] The optical adhesive was coated onto a non-silicone release film (75 μm thick, release force 30 gf / 25 mm) with a thickness of 250 μm by a scraper, and then thermo-cured (curing conditions: 60 °C, 10 min). A fluorine release film (50 μm thick, release force 13 gf / 25 mm) was then attached to the side of the resulting optical adhesive layer away from the non-silicone release film to obtain the organosilicon OCA.

[0148] Application Example 2-6, Application Comparative Example 1-3

[0149] An optical adhesive and its preparation method are disclosed. The only difference between this adhesive and Application Example 1 is that the boron-containing organosilicon provided in Example 1 is replaced in equal amounts with the boron-containing organosilicon provided in Examples 2-6 and Comparative Examples 1-3. All other raw materials, process parameters and steps are the same as in Application Example 1.

[0150] The optical adhesive is used in the preparation of organosilicon OCA, and the preparation method of the organosilicon OCA is the same as in Application Example 1.

[0151] Application Comparative Example 4

[0152] An optical adhesive and its preparation method are disclosed. The only difference between this adhesive and Application Example 1 is that the boron-containing organosilicon provided in Example 1 is replaced with an equal amount of silane coupling agent KH-560. All other raw materials, process parameters and steps are the same as in Application Example 1.

[0153] The optical adhesive is used in the preparation of organosilicon OCA, and the preparation method of the organosilicon OCA is the same as in Application Example 1.

[0154] Application Comparative Example 5

[0155] An optical adhesive and its preparation method are disclosed. The only difference between this and Application Example 1 is that the boron-containing organosilicon provided in Example 1 is replaced with an equal amount of the boron-containing organosilicon provided in Comparative Example 5. All other raw materials, process parameters and steps are the same as in Application Example 1. Since the refractive index of the boron-containing organosilicon provided in Comparative Example 5 is significantly different from that of the organosilicon polymer, severe fogging occurs during the preparation of the optical adhesive, which does not meet the requirements of the optical adhesive.

[0156] Performance testing

[0157] (1) Peel strength test: The optical adhesive layer of the silicone OCA provided in the application example and the application comparison example was attached to the substrate on one side and to the PET film (purchased from Hefei Lucky Technology, with a thickness of 100μm) on the other side to form a combination structure of PET-silicone OCA-substrate. The film was placed on an electric roller machine (Beidou Instruments, PT-509) and rolled once at a speed of 10mm / s using a 3kg roller to obtain the peel test sample of the corresponding substrate. After sample preparation, the peel strength at 180° was tested at different placement times according to GB / T2792-2014 after waiting for 0min, 3min and 5min respectively.

[0158] (2) Transmittance and haze test: The test shall be conducted in accordance with GB / T 2410 7.1;

[0159] (3) Glass transition temperature: tested using Hitachi's DSC200;

[0160] The organosilicon OCAs provided in Application Examples 1-6 and Comparative Examples 1-4 were tested according to the above method. The test results are shown in Tables 1 and 2 below:

[0161] Table 1

[0162] Table 2

[0163] The test data in the table show that controlling the molar ratio of B to Si in the raw materials for preparing boron-containing organosilicon within the range of 1:(5-11.5) enables the organosilicon OCA to exhibit good adhesion to substrates such as inks, glass, and polarizers, and also demonstrates excellent hydrolysis resistance. Compared to the commonly used tackifiers, silane coupling agents, in organosilicon OCA applications, the organosilicon OCAs provided in Examples 1-6 show varying degrees of improvement in the adhesion performance to inks, glass, and polarizer substrates. The initial peel force is greater than 2N / 25mm, and the peel force increases rapidly, reaching its final value within 5 minutes. The final peel force for inks, glass, and polarizers can reach a maximum of approximately 22N / 25mm. Furthermore, after double 85 aging, the haze change is small, and the high temperature and humidity resistance is excellent.

[0164] In Application Examples 2-6, the molar ratio of B to Si in the boron-containing organosilicon raw materials is within the range of 1:(6.5-11.5). The organosilicon OCA shows a particularly significant improvement in the adhesion performance of ink, glass, and polarizer substrates. In Comparative Example 4, KH-560 was used as an tackifier. The peel force of the organosilicon OCA increased slowly after bonding. For the polarizer, the peel force only reached its final value of 2.44 N / 25 mm after 96 hours. For glass and ink, the peel force reached its final value of 13.8 N / 25 mm and 3.57 N / 25 mm, respectively, after 48 hours. Furthermore, the organosilicon OCA provided in this application has a glass transition temperature below -40°C, exhibiting excellent low-temperature resistance and meeting the application requirements of various scenarios.

[0165] In Comparative Example 1, the molar ratio of hydroxyl to alkoxy groups in the boron-containing organosilicon raw material was 1.15:1. The high OH content in the boron-containing organosilicon raw material increased the likelihood of boric acid being exposed at the end. The boron-containing organosilicon was easily attacked by moisture and fogged. The organosilicon OCA had poor hydrolysis resistance and would absorb moisture from the air, causing the film to fog.

[0166] In Comparative Example 2 and Comparative Example 3, the molar ratio of B to Si in the raw materials for preparing boron-containing organosilicon was 1:12.3 and 1:3.7, respectively. If the B content in the raw materials for preparing boron-containing organosilicon was too low, the adhesive performance would be significantly worse; if the B content was too high, the organosilicon OCA would have poor hydrolysis resistance and would absorb moisture from the air, causing the adhesive film to fog up.

[0167] The applicant declares that this application illustrates the boron-containing organosilicon, optical adhesive, organosilicon OCA, and their preparation methods and applications through the above embodiments and application examples. However, this application is not limited to the above embodiments and application examples, that is, it does not mean that this application must rely on the above embodiments and application examples to be implemented.

Claims

1. A boron-containing organosilicon, the raw materials for its preparation comprising a combination of silanols, siloxane monomers and boric acid compounds; In the raw materials for preparing boron-containing organosilicon, the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups is (0.8-1.1):1, and the ratio of the total molar amount of B elements to the total molar amount of Si elements is 1:(5-11.5).

2. The boron-containing organosilicon according to claim 1, wherein, The general formula of the silanol is R 11 4-a Si(OH) a ; Among them, R 11 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl or C3-C8 cyclic hydrocarbon groups; a is 2 or 3; Preferably, the silanol includes any one or a combination of at least two of dimethylsilanediol, methylethylsilanediol, methylphenylsilanediol, methylsilanetriol, or phenylsilanetriol.

3. The boron-containing organosilicon according to claim 1 or 2, wherein, The general formula of the siloxane monomer is R 12 4-b Si(OR 13 ) b ; Among them, R 12 Each is independently selected from any one of C2-C6 unsaturated hydrocarbon groups or C1-C5 straight-chain or branched alkyl groups; R 13 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl groups; b is selected from an integer between 1 and 3, preferably 2 or 3; Preferably, the siloxane monomer includes a first siloxane monomer, a second siloxane monomer, and optionally a third siloxane monomer; The general formula of the first siloxane monomer is R A1 2Si(OR A2 )2; The general formula of the second siloxane monomer is R B1 Si(OR B2 )3; The general formula of the third siloxane monomer is R C1 3SiOR C2 ; Among them, R A1 R B1 and R C1 Each is independently selected from any one of C2-C6 unsaturated hydrocarbon groups or C1-C5 straight-chain or branched alkyl groups; R A2 R B2 and R C2 Each is independently selected from any one of C1-C5 straight-chain or branched alkyl groups; Preferably, the first siloxane monomer comprises any one or a combination of at least two of methylvinyldimethoxysilane, dimethyldimethoxysilane, or dimethyldiethoxysilane; Preferably, the second siloxane monomer comprises methyltrimethoxysilane and / or methyltriethoxysilane; Preferably, the third siloxane monomer comprises trimethylmethoxysilane.

4. The boron-containing organosilicon according to any one of claims 1-3, wherein, The boric acid compounds include any one or a combination of at least two of boric acid, phenylboronic acid, or tetrahydroxyboronic acid; Preferably, the molar ratio of the hydroxyl groups in the boric acid compound to the hydroxyl groups in the silanol is 1:(1-7); Preferably, in the raw materials for preparing boron-containing organosilicon, the ratio of the total molar amount of B element to the total molar amount of Si element is 1:(6.5-11.5), more preferably 1:(7-8.5).

5. The boron-containing organosilicon according to any one of claims 1-4, wherein the raw materials for its preparation further include a solvent; Preferably, the solvent includes any one or a combination of at least two of N,N-dimethylformamide, dimethyl sulfoxide, methanol, acetonitrile, isopropanol, 1,4-dioxane or cyclohexanone; Preferably, the solvent comprises 25-40% of the total mass of the silanol, siloxane monomer, and boric acid compound, which is 100% of the total mass.

6. A method for preparing boron-containing organosilicon as described in any one of claims 1-5, comprising: The boron-containing organosilicon is obtained by reacting silanols, siloxane monomers, and boric acid compounds. Preferably, the reaction temperature is 80-140°C; Preferably, the reaction time is 3-7 hours; Preferably, the reaction is carried out in the presence of a solvent; Preferably, the reaction further includes a step of vacuum distillation after completion.

7. An application of the boron-containing organosilicon as described in any one of claims 1-5, wherein, The boron-containing organosilicon is used as a tackifier in optical adhesives.

8. An optical adhesive, comprising, by weight, the following raw materials:

9. The optical adhesive according to claim 8, wherein, The vinyl silicone resin includes any one or a combination of at least two of vinyl MQ silicone resin, vinyl MDT silicone resin, vinyl MTQ silicone resin, or vinyl DT silicone resin. Preferably, the viscosity of the vinyl silicone resin at 25°C is 5000-50000 mPa·s; Preferably, the vinyl content of the vinyl silicone resin is 0.3-1.0 mmol / g.

10. The optical adhesive according to claim 8 or 9, wherein, The vinyl silicone oil includes any one or a combination of at least two of the following: silicone oil with vinyl end groups, silicone oil with vinyl side groups, or silicone oil with vinyl end groups and vinyl side groups. Preferably, the viscosity of the vinyl silicone oil at 25°C is 100-20000 mPa·s; Preferably, the vinyl content of the vinyl silicone oil is 0.1-0.75 mmol / g.

11. The optical adhesive according to any one of claims 8-10, wherein, The general formula of the hydrogen-containing silicone resin is (R 21 R 22 R 23 SiO 1 / 2 ) x (R 24 R 25 SiO 2 / 2 ) y (R 26 SiO 3 / 2 ) z ; Among them, R 21 R 22 R 23 R 24 R 25 and R 26 Each is independently selected from any one of hydrogen atoms or C1-C5 straight-chain or branched alkyl groups, and R 21 R 22 R 23 R 24 R 25 and R 26 At least one of them is a hydrogen atom; x:y:z = 1:(0.2-0.3):(2-3); Preferably, the viscosity of the hydrogen-containing silicone resin at 25°C is 10000-40000 mPa·s; Preferably, the hydroxyl group content of the hydrogen-containing silicone resin is 0.1-1.2 mmol / g.

12. The optical adhesive according to any one of claims 8-11, wherein, The general formula of the hydrogen-containing silicone oil is (R 31 R 32 R 33 SiO 1 / 2 ) p (R 34 R 35 SiO 2 / 2 ) m (R 36 R 37 SiO 2 / 2 ) n ; Among them, R 31 R 32 R 33 R 34 R 35 R 36 and R 37 Each is independently selected from any one of hydrogen atoms or C1-C5 straight-chain or branched alkyl groups, and R 34 R 35 R 36 and R 37 At least one of them is a hydrogen atom; 1≤p≤2, 0≤m≤50, 0≤n≤50, and m and n are not both 0; Preferably, the viscosity of the hydrogen-containing silicone oil at 25°C is 100-3000 mPa·s; Preferably, the hydrogen-containing silicone oil has a hydroxyl content of 0.05-0.5 mmol / g; Preferably, in the raw materials for preparing the optical adhesive, the ratio of the total molar amount of vinyl groups to the total molar amount of silane groups is (0.95-1.05):

1.

13. The optical adhesive according to any one of claims 8-12, wherein, The catalyst includes any one or a combination of at least two of chloroplatinic acid, Karstedt platinum catalyst or Willing platinum catalyst; Preferably, the raw materials for preparing the optical adhesive further include 0.2-0.5 parts by weight of an inhibitor; Preferably, the inhibitor comprises an alcohol compound containing an unsaturated group and / or a siloxane containing at least two vinyl groups; Preferably, the inhibitor comprises any one or a combination of at least two of 1,4-butynediol, ethynylcyclohexanol, tetramethyltetravinylcyclotetrasiloxane, or 2-methyl-3-butyn-2-ol.

14. An organosilicon OCA, comprising a first release film, an optical adhesive layer, and a second release film sequentially stacked; wherein the optical adhesive layer is formed by curing an optical adhesive as described in any one of claims 8-13; Preferably, the thickness of the optical adhesive layer is 20-2000 μm; Preferably, the thickness of the first release film and the second release film are each independently 50-200 μm; Preferably, the release force difference between the first release film and the second release film is 15-20 gf / 25 mm.

15. The use of an optical adhesive as described in any one of claims 8-13 or an organosilicon OCA as described in claim 14 in display bonding.

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