Boron-containing oligomer for anti-aging high-transparency addition type silicone rubber as well as preparation method and application of boron-containing oligomer

Abstract

The invention discloses a boron-containing oligomer for anti-aging high-transparency addition type silicone rubber as well as a preparation method and application of the boron-containing oligomer. The boron-containing oligomer disclosed by the invention is a boron-containing oligomer containing an unsaturated bond; the unsaturated bond is selected from at least one of a carbon-carbon double bond, a carbon-carbon triple bond and a large pi bond; the boron-containing oligomer comprises at least one boron-oxygen-silicon bond. The boron-containing oligomer prepared by the invention is used as a tackifier in addition type silicone rubber, so that the adhesion performance of the addition type silicone rubber to metal and plastic substrates can be greatly improved on the premise of ensuring high transparency under the condition that a traditional primer is not used; therefore, the application range of the addition type silicone rubber bonding sealant is greatly expanded.

Description

Technical Field

[0001] The invention belongs to the field of silicone rubber bonding sealing materials and preparation thereof, and particularly relates to a boron-containing oligomer for aging-resistant high-transparency addition-type silicone rubber and a preparation method and application thereof. Background Art

[0002] Addition silicone rubber is a polysiloxane containing vinyl and polysiloxane containing multiple silicon-hydrogen bonds, which is vulcanized by silicon-hydrogen addition under the action of platinum catalyst. This type of silicone rubber is widely used due to its excellent properties such as no by-products produced during the vulcanization process, relatively low vulcanization temperature, and short vulcanization time. However, due to its poor adhesion to the substrate, addition silicone rubber requires a large amount of primer to treat the substrate surface during use. This shortcoming has increased the cost and workload of use. Therefore, the study of high-efficiency tackifiers to achieve bulk tackification of addition silicone rubber plays an important role in the development of addition silicone rubber.

[0003] In previous research work, many patent works have also reported on addition-type silicone rubber adhesives. Chinese patent CN202210664176.1 reported a two-component tackifier to prepare polysiloxanes containing epoxy groups and amino groups. Chinese patent CN202110272736.4 prepared silanes or siloxanes containing acrylic groups. The tackifiers mentioned in these patents have a certain effect on improving the adhesion of metals and plastics, but the effect is not obvious.

[0004] In the previous work of this research group, a borate ester thickener for addition silicone rubber was synthesized in Chinese patent CN201410748954.0, and a boron-containing small molecule thickener for addition silicone rubber was synthesized in Chinese patent CN201410725194.1. Both of these thickeners can significantly improve the bonding strength on metal steel sheets and the shear strength on PET films, but the transparency of addition silicone rubber will be affected after the addition of the above two thickeners, and their preparation process is complicated and costly, which is not conducive to promotion and utilization. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to improve the bonding performance of addition silicone rubber to metal and plastic substrates while maintaining high transparency and good aging resistance.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A boron-containing oligomer, wherein the boron-containing oligomer is a boron-containing oligomer containing unsaturated bonds; the unsaturated bonds are selected from at least one of carbon-carbon double bonds, carbon-carbon triple bonds, and large π bonds; the boron-containing oligomer includes at least one boron-oxygen-silicon bond, for example, two boron-oxygen-silicon bonds, three boron-oxygen-silicon bonds, and five boron-oxygen-silicon bonds.

[0008] According to an embodiment of the present invention, the raw materials of the boron-containing oligomer include: small molecular alkoxysilane containing unsaturated bonds and a compound containing active boron hydroxyl groups.

[0009] According to an embodiment of the present invention, the boron-containing oligomer is obtained by condensing a small molecular alkoxysilane containing an unsaturated bond with a compound containing an active boron hydroxyl group.

[0010] According to an embodiment of the present invention, the small molecule alkoxysilane containing an unsaturated bond is selected from at least one of the following: γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, allyltrimethoxysilane, triethoxyphenylsilane, triethoxyvinylsilane, 3-glycidyloxypropyltriethoxysilane, trimethoxyphenylsilane, tri(2-methoxyethoxy)vinylsilane, vinyltrimethoxysilane, trimethoxy(2-phenylethyl)silane, (3-glycidylpropoxy)trimethoxysilane, diethoxy(methyl)phenylsilane, dimethoxydiphenylsilane, diethoxymethyl[(3-oxiranylmethoxy)propyl]silane, diethoxy(methyl)vinylsilane.

[0011] According to an embodiment of the present invention, the compound containing active boronic hydroxyl group is selected from at least one of the following: 4-nitrobenzeneboronic acid, 2-chlorophenylboronic acid, 3-chlorophenylboronic acid, isopropylboronic acid, 3-hydroxyphenylboronic acid, 4-iodophenylboronic acid, butylboronic acid, 4-vinylbenzeneboronic acid, 3-cyanophenylboronic acid, 3-hydroxymethylbenzeneboronic acid, phenethylboronic acid, 3-furanboronic acid, 8-quinolineboronic acid, but-3-eneboronic acid, 2-thiopheneboronic acid, p-methylphenylboronic acid, cyclohexylboronic acid, 2-pyridineboronic acid, 4-ethylphenylboronic acid, and 1-phenylvinylboronic acid.

[0012] The present invention also provides a method for preparing the above-mentioned boron-containing oligomer, which comprises: subjecting a small molecule alkoxysilane containing an unsaturated bond to a condensation reaction with a compound containing an active boron hydroxyl group to obtain the boron-containing oligomer.

[0013] According to an embodiment of the present invention, in the preparation method, the small molecule alkoxysilane containing an unsaturated bond and the compound containing an active boron hydroxyl group have the meanings as described above.

[0014] According to an embodiment of the present invention, in the preparation method, the molar ratio of the small molecule alkoxysilane containing an unsaturated bond to the compound containing an active boron hydroxyl group is 1:0.3-3, for example, 1:0.33, 1:0.5, 1:0.83 or 1:1.

[0015] According to an embodiment of the present invention, a polycondensation catalyst is also added during the polycondensation reaction. Preferably, the polycondensation catalyst is selected from at least one of sulfonated resins, cation exchange resins, anion exchange resins, aluminosilicates, ZSM-5 zeolites, etc., preferably anion exchange resins. Further, the anion exchange resin is selected from at least one of FPA53 anion exchange resin, 717 strong basic styrene anion exchange resin, D392 macroporous anion exchange resin, LX-TS4 macroporous strong basic anion exchange resin, IRA-411 anion exchange resin, D900 macroporous weak basic anion exchange resin, Q strong anion exchange resin Rigose Q, and DEAE weak anion exchange resin Rigose DEAE HiRes.

[0016] According to an embodiment of the present invention, the temperature of the condensation reaction is 30-100°C, for example, 60°C or 70°C.

[0017] According to an embodiment of the present invention, the pressure of the reaction system of the condensation reaction is maintained at 0.01 MPa-2 MPa, for example, 0.1 MPa.

[0018] According to an embodiment of the present invention, in order to promote the condensation reaction to proceed fully, the preparation method further comprises adding a solvent during the condensation reaction so that the entire reaction system is carried out in a solvent environment.

[0019] According to an embodiment of the present invention, in the preparation method, the solvent is selected from at least one of ethanol, methanol, toluene, ethyl acetate, tetrahydrofuran, acetone, acetonitrile, n-hexane, dichloromethane, isopropanol, xylene, and petroleum ether.

[0020] According to an embodiment of the present invention, in the preparation method, after adding the solvent, the mass fraction of the reactants in the reaction system is 5%-50%, for example, 10%. In the present invention, the reactants include small molecular alkoxysilane containing unsaturated bonds and compounds containing active boron hydroxyl groups.

[0021] The present invention also provides the use of the above-mentioned boron-containing oligomer containing unsaturated bonds in aging-resistant addition-type silicone rubber, preferably as a tackifier.

[0022] The present invention also provides an addition type silicone rubber composition, which comprises the following components: an addition type silicone rubber base glue, a reinforcing filler, a tackifier and a catalyst, wherein the tackifier comprises the above-mentioned boron-containing oligomer.

[0023] According to an embodiment of the present invention, the reinforcing filler is selected from vinyl MQ silicone resin.

[0024] According to an embodiment of the present invention, the mass of the reinforcing filler is 30%-100% of the mass of the addition silicone rubber base, for example, 65%.

[0025] According to an embodiment of the present invention, the mass of the tackifier is 0.5%-3% of the mass of the addition silicone rubber base, for example, 0.61%, 1.57%, 1.75% or 2.49%.

[0026] According to an embodiment of the present invention, the catalyst is selected from platinum catalysts.

[0027] According to an embodiment of the present invention, the mass of the platinum catalyst is 0.5‰-2‰ of the mass of the addition silicone rubber base, for example, 1‰.

[0028] According to an embodiment of the present invention, the addition type silicone rubber base glue comprises a mixture of vinyl-terminated silicone oil and hydrogen-containing MQ silicone resin. Preferably, the hydrogen content of the hydrogen-containing MQ silicone resin is 0.1-1%, for example, 0.4%. Preferably, the viscosity of the vinyl-terminated silicone oil is 50000-200000 mPa.s, for example, 100000 mPa.s.

[0029] According to an embodiment of the present invention, in the addition type silicone rubber base adhesive, the mass ratio of the vinyl-terminated silicone oil to the hydrogenated MQ silicone resin is 1-10:0.1-5, for example, 10:3.6.

[0030] The present invention also provides a bonding sealant, which is prepared by the addition type silicone rubber composition.

[0031] Preferably, the adhesive sealant is prepared according to a method comprising the following steps: uniformly mixing the boron-containing oligomer, addition silicone rubber base, reinforcing filler and platinum catalyst, and then kneading the obtained mixture to obtain the adhesive sealant.

[0032] Beneficial effects:

[0033] The present invention conducts a condensation reaction between a small molecule alkoxysilane containing an unsaturated bond and a compound containing an active boron hydroxyl group to obtain a boron-containing oligomer containing an unsaturated bond. The boron-containing oligomer prepared according to the present invention is used as a tackifier in addition-type silicone rubber, and can greatly improve the bonding performance of the addition-type silicone rubber to metal and plastic substrates without using a traditional primer while ensuring high transparency, thereby greatly expanding the application range of addition-type silicone rubber adhesive sealants. The preparation method of the boron-containing oligomer containing an unsaturated bond according to the present invention is novel, efficient, low-cost, has a high product purity, and a simple operating process, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is the molecular structure formula of Example 1.

[0035] Figure 2 NMR of Example 1 29 Si spectrum.

[0036] Figure 3 It is the molecular structure formula of Example 3.

[0037] Figure 4 NMR of Example 3 29 Si spectrum.

[0038] Figure 5 The violet visible absorption spectra of Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, Example 5, and Example 7 are shown. DETAILED DESCRIPTION

[0039] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0040] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0041] In the following examples, the shear strength test of the samples was conducted with reference to GB 7124-2008, a method for determining the tensile shear strength of adhesives; and the transparency test was conducted with reference to GB / T 2410-2008, a method for determining the transmittance and haze of transparent plastics.

[0042] Example 1. Preparation of boron-containing oligomer 1

[0043] In a 500ml three-necked flask equipped with a serpentine condenser, 5.92g of p-vinylbenzeneboric acid and 15.2g of vinyltriethoxysilane (the molar ratio of vinyltriethoxysilane to p-vinylbenzeneboric acid is 1:0.5) were added, and 0.2112g of A854519 or 717 strong alkaline styrene anion exchange resin produced by MacLean Company was added as a catalyst, and completely dissolved in 211.2g of anhydrous ethanol. After stirring at room temperature for 1h to mix evenly, the mixture was heated to 65°C and reacted for 6 hours. The anion exchange resin was removed by suction filtration, most of the anhydrous ethanol was removed from the reaction system by rotary evaporation, and the residual anhydrous ethanol was removed by reduced pressure distillation. After about 1h, the reaction was stopped when no bubbles appeared to obtain boron-containing oligomer 1.

[0044] The structural formula of the boron-containing oligomer 1 synthesized in this example is as follows Figure 1 As shown, the synthesized boron-containing oligomer 1 has one, two, and three boron-oxygen-silicon bonds.

[0045] The NMR Si spectrum of the boron-containing oligomer 1 synthesized in this example is as follows Figure 2 As shown, -57.16ppm and -59.02ppm are the NMR peaks of one boron-oxygen-silicon bond in the oligomer and its split peak, -65.98ppm and -67.53ppm are the NMR peaks of two boron-oxygen-silicon bonds in the oligomer and their split peaks, and -74.06ppm and -75.29ppm are the NMR peaks of two boron-oxygen-silicon bonds in the oligomer and their split peaks. It can be seen from the NMR results that the boron-containing oligomer 1 obtained in this example has Figure 1 The structure shown.

[0046] Example 2: Preparation of Boron-Containing Oligomer 2

[0047] In a 500 ml three-necked flask equipped with a serpentine condenser, 5.92 g of p-vinylbenzeneboric acid and 22.8 g of vinyltriethoxysilane (the molar ratio of vinyltriethoxysilane to p-vinylbenzeneboric acid is 1:0.33) were added, and 0.2872 g of A854519 or 717 strong alkaline styrene anion exchange resin produced by MacLean Company was added as a catalyst, and completely dissolved in 287.2 g of anhydrous ethanol. After stirring at room temperature for 1 hour to mix evenly, the mixture was heated to 65°C and reacted for 6 hours. The anion exchange resin was removed by suction filtration, and most of the anhydrous ethanol was removed from the reaction system by rotary evaporation. The residual anhydrous ethanol was removed by reduced pressure distillation. After about 1 hour, the reaction was stopped when no bubbles appeared to obtain boron-containing oligomer 2.

[0048] Example 3. Preparation of Boron-Containing Oligomer 3

[0049] In a 500ml three-necked flask equipped with a serpentine condenser, 14.8g of p-vinylbenzeneboronic acid and 16g of methylvinyldiethoxysilane (the molar ratio of methylvinyldiethoxysilane to p-vinylbenzeneboronic acid is 1:1) were added, and 0.308g of A854519 or 717 strong alkaline styrene anion exchange resin produced by MacLean Company was added as a catalyst, and completely dissolved in 308g of anhydrous ethanol. After stirring at room temperature for 1h to mix evenly, the mixture was heated to 65°C and reacted for 6 hours. The anion exchange resin was removed by suction filtration, and most of the anhydrous ethanol was removed from the reaction system by rotary evaporation. The residual anhydrous ethanol was removed by vacuum distillation. After about 1h, the reaction was stopped when no bubbles appeared to obtain boron-containing oligomer 3. The structure of the synthesized oligomer is as follows: Figure 3 As shown in Figure 2, the synthesized oligomer has one or two boron-oxygen-silicon bonds. The peak at -18.61ppm is the peak of the raw material methyldiethoxyvinylsilane. The NMR silicon spectrum of the synthesized oligomer is as follows: Figure 2As shown, -27.56ppm and -35.52ppm are the end group peak and the silicon-oxygen main chain peak, respectively. It was judged by NMR that the above oligomer was successfully synthesized.

[0050] Example 4. Preparation of Boron-Containing Oligomer 4

[0051] In a 500 ml three-necked flask equipped with a serpentine condenser, 7.4 g of p-vinylbenzeneboric acid and 16 g of methylvinyldiethoxysilane (the molar ratio of methylvinyldiethoxysilane to p-vinylbenzeneboric acid is 1:0.5) were added, and 0.234 g of A854519 or 717 strong alkaline styrene anion exchange resin produced by MacLean Company was added as a catalyst, and completely dissolved in 234 g of anhydrous ethanol. After stirring at room temperature for 1 hour to mix evenly, the mixture was heated to 65°C and reacted for 6 hours. The anion exchange resin was removed by suction, and most of the anhydrous ethanol was removed from the reaction system by rotary evaporation. The residual anhydrous ethanol was removed by reduced pressure distillation. After about 1 hour, the reaction was stopped when no bubbles appeared to obtain boron-containing oligomer 4.

[0052] Example 5

[0053] Preparation and performance determination of addition type silicone rubber adhesive sealant 1:

[0054] A composition was obtained by uniformly mixing 0.17 g of the boron-containing oligomer 1 obtained in Example 1, 8.5 g of vinyl-terminated silicone oil with a viscosity of 100,000 mPa.s, 3 g of hydrogen-containing MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of a platinum catalyst.

[0055] The above composition was coated on a stainless steel sheet and a PET film respectively according to the method of GB 7124-2008 to prepare shear specimens, and the addition silicone rubber adhesive sealant was obtained after curing at 120°C for 2h. The stainless steel shear strength and the PET shear strength were tested respectively. The above composition was then prepared into a 200 μm film by a calender, and cured at 120°C for 2h. The light transmittance and haze of the film were measured on a TH-100 haze meter.

[0056] The shear strength and transmittance haze test results are shown in Table 1.

[0057] Example 6

[0058] The preparation of the addition type silicone rubber adhesive sealant 2 is basically the same as that of Example 5, except that:

[0059] 0.34 g of the boron-containing oligomer 1 obtained in Example 1 was added to the composition, and the rest was the same as in Example 5.

[0060] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0061] Example 7

[0062] The preparation of the addition type silicone rubber adhesive sealant 3 is basically the same as that of Example 5, except that:

[0063] 0.17 g of the boron-containing oligomer 2 obtained in Example 2 was added to the composition, and the rest was the same as in Example 5.

[0064] The shear strength and light transmittance haze tests are basically the same as those in Example 5, except that the composition of this example is used to prepare the sample and film, and then the test is performed.

[0065] Example 8

[0066] The preparation of addition type silicone rubber 4 is basically the same as that of Example 5, except that:

[0067] 0.34 g of the boron-containing oligomer 2 obtained in Example 2 was added to the composition, and the rest was the same as in Example 5.

[0068] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0069] Example 9

[0070] The preparation of the addition type silicone rubber adhesive sealant 5 is basically the same as that of Example 5, except that:

[0071] 0.17 g of the boron-containing oligomer 3 obtained in Example 3 was added to the composition, and the rest was the same as in Example 5.

[0072] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0073] Example 10

[0074] The preparation of the addition type silicone rubber adhesive sealant 6 is basically the same as that of Example 5, except that:

[0075] 0.34 g of the boron-containing oligomer 3 obtained in Example 3 was added to the composition, and the rest was the same as in Example 5.

[0076] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0077] Embodiment 11

[0078] The preparation of the addition type silicone rubber adhesive sealant 7 is basically the same as that of Example 5, except that:

[0079] 0.17 g of the boron-containing oligomer 4 obtained in Example 4 was added to the composition, and the rest was the same as in Example 5.

[0080] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0081] Example 12

[0082] The preparation of the addition type silicone rubber adhesive sealant 8 is basically the same as that of Example 5, except that:

[0083] 0.34 g of the boron-containing oligomer 4 obtained in Example 4 was added to the composition, and the rest was the same as in Example 5.

[0084] The shear strength and transmittance haze tests are basically the same as those in Example 5, except that the shear specimens and films are prepared using the composition of this example and tested.

[0085] Example 13

[0086] Aging test:

[0087] The shear samples and films prepared on the stainless steel sheet and PET film obtained in Example 5 were placed in a constant temperature and humidity chamber at 85°C and 85% relative humidity for 168 hours to simulate a 1000-hour aging experiment, and the shear strength and transmittance of the aged samples were tested.

[0088] Embodiment 14

[0089] The aging experiment of this embodiment is basically the same as that of Embodiment 13, except that the shear test specimens and films of Embodiment 7 are used for the aging test, and the shear strength and light transmittance of the obtained aged samples are tested.

[0090] Embodiment 15

[0091] The aging experiment of this embodiment is basically the same as that of Embodiment 13, except that the shear test specimens and films of Embodiment 9 are used for the aging test, and the shear strength and light transmittance of the obtained aged samples are tested.

[0092] Example 16

[0093] The aging experiment of this embodiment is basically the same as that of Embodiment 13, except that the shear test specimen and film of Embodiment 11 are used for the aging test, and the shear strength and light transmittance of the obtained aged samples are tested.

[0094] Comparative Example 1

[0095] 8.5 g of vinyl-terminated silicone oil with a viscosity of 100,000 mPa.s, 3 g of hydrogenated MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of platinum catalyst were uniformly mixed to obtain a composition, and the composition was respectively coated on a stainless steel sheet and a PET film to prepare a shear specimen, and cured at 120°C for 2 hours; and the composition was coated into a 200-micron thin film by a calender.

[0096] Referring to Example 5, the shear strength of the shear specimen of this comparative example and the light transmittance and haze of the film were tested respectively. The test results are shown in Table 1.

[0097] Comparative Example 2

[0098] 0.17 g of vinyl triethoxysilane, 8.5 g of terminal vinyl silicone oil with a viscosity of 100,000 mPa.s, 3 g of hydrogenated MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of platinum catalyst were mixed evenly, and applied on stainless steel sheets and PET films respectively to prepare shear specimens, cured at 120°C for 2 h, and coated on a calender to form a 200-micron film.

[0099] Referring to Example 5, the shear strength of the shear specimen of this comparative example and the light transmittance and haze of the film were tested respectively. The test results are shown in Table 1.

[0100] Comparative Example 3

[0101] 0.17 g of methylvinyldiethoxysilane, 8.5 g of terminal vinyl silicone oil with a viscosity of 100,000 mPa.s, 3 g of hydrogenated MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of platinum catalyst were mixed evenly, and applied on stainless steel sheets and PET films respectively to prepare shear specimens, cured at 120°C for 2 h, and coated on a calender to form a 200-micron film.

[0102] Referring to Example 5, the shear strength of the shear specimen of this comparative example and the light transmittance and haze of the film were tested respectively. The test results are shown in Table 1.

[0103] Comparative Example 4

[0104] Referring to Example 3 in Chinese Patent CN201410748954.0, a borate ester thickener was prepared. 0.17 g of the borate ester thickener, 8.5 g of terminal vinyl silicone oil with a viscosity of 100000 mPa.s, 3 g of hydrogenated MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of platinum catalyst were mixed evenly, and applied on a stainless steel sheet and a PET film to prepare shear specimens, respectively, cured at 120°C for 2h, and coated on a calender to form a 200 μm film.

[0105] Referring to Example 5, the shear strength of the shear specimen of this comparative example and the light transmittance and haze of the film were tested respectively. The test results are shown in Table 1.

[0106] Comparative Example 5

[0107] Referring to Example 4 in Chinese Patent CN201410725194.1, a boron-containing small molecule thickener was prepared. 0.17 g of the boron-containing small molecule thickener, 8.5 g of terminal vinyl silicone oil with a viscosity of 100000 mPa.s, 3 g of hydrogen-containing MQ silicone resin with a hydrogen content of 0.4%, 5.5 g of vinyl MQ silicone resin and 0.017 g of platinum catalyst were mixed evenly, and applied on stainless steel sheets and PET films to prepare shear specimens, respectively, cured at 120°C for 2h, and coated on a calender to form a 200-micron film.

[0108] Referring to Example 5, the shear strength of the shear specimen of this comparative example and the light transmittance and haze of the film were tested respectively. The test results are shown in Table 1.

[0109] Table 1

[0110] performance Stainless steel shear strength (MPa) PET shear strength (MPa) Light transmittance (%) Haze Example 5 4.6 3.5 93.8 1.04 Example 6 5.72 3.86 93.6 1.13 Example 7 3.87 4.03 94.1 2.59 Example 8 4.89 4.59 94.2 2.31 Example 9 4.35 3.21 93.9 0.88 Example 10 4.37 3.17 94 1.63 Embodiment 11 5.16 4.05 93.8 1.43 Example 12 6.18 4.43 93.5 1.89 Example 13 4.43 2.96 92.7 3.14 Embodiment 14 3.91 3.27 93.1 4.17 Embodiment 15 4.07 2.81 93.7 2.61 Example 16 4.91 3.64 92.4 3.49 Comparative Example 1 3.25 2.35 94.4 1.02 Comparative Example 2 4.47 2.28 94.1 1.64 Comparative Example 3 4.15 2.83 94.6 1.81 Comparative Example 4 4.42 3.45 84.3 4.84 Comparative Example 5 5.44 3.87 81.7 4.47

[0111] As shown in Table 1, the bonding performance of traditional addition-type silicone rubber to stainless steel and PET film is very poor. After adding vinyl triethoxysilane and methyl vinyl diethoxysilane, there is a certain improvement. The shear strength of stainless steel substrate can be increased by up to 37%, and the shear strength of PET substrate can be increased by 20%. After adding the boron-containing oligomer in the present invention as a tackifier, the bonding performance is greatly improved, and the more the amount added, the greater the performance improvement. The shear strength of stainless steel substrate can be increased by up to 90%, and the shear strength of PET substrate can be increased by 95%. Moreover, from Table 1 and Figure 5 It can be seen from the data that the addition of the boron-containing oligomer as a tackifier in the present invention does not have a significant impact on the transmittance and haze of the addition type silicone rubber adhesive sealant system; the UV-visible absorption spectrum shows that the addition of the boron-containing small molecule tackifier and the borate ester tackifier will have a significant effect on the transmittance of the addition type silicone rubber adhesive sealant system in the UV-visible light band. After aging test at 85°C and relative humidity of 85% for 168 hours, the bonding strength of stainless steel and PET film is well maintained, and the transmittance and haze do not show obvious attenuation.

[0112] The above is a description of the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A boron-containing oligomer, characterized in that: The boron-containing oligomer is a boron-containing oligomer containing unsaturated bonds; the unsaturated bonds are selected from at least one of carbon-carbon double bonds, carbon-carbon triple bonds, and large π bonds; the boron-containing oligomer includes at least one boron-oxygen-silicon bond.

2. The boron-containing oligomer according to claim 1, characterized in that The raw materials of the boron-containing oligomer include: small molecular alkoxysilane containing unsaturated bonds and compounds containing active boron hydroxyl groups. Preferably, the boron-containing oligomer is obtained by condensing a small molecular alkoxysilane containing an unsaturated bond with a compound containing an active boron hydroxyl group.

3. The boron-containing oligomer according to claim 1 or 2, characterized in that The small molecule alkoxysilane containing unsaturated bonds is selected from at least one of the following: γ-glycidyloxypropyl trimethoxysilane, γ-(methacryloyloxy)propyl trimethoxysilane, γ-aminopropyl triethoxysilane, allyl trimethoxysilane, triethoxyphenyl silane, triethoxyvinyl silane, 3-glycidyloxypropyl triethoxysilane, trimethoxyphenyl silane, tri(2-methoxyethoxy)vinyl silane, vinyl trimethoxysilane, trimethoxy(2-phenylethyl)silane, (3-glycidylpropoxy)trimethoxysilane, diethoxy(methyl)phenyl silane, dimethoxydiphenylsilane, diethoxymethyl[(3-oxiranylmethoxy)propyl]silane, diethoxy(methyl)vinyl silane. Preferably, the compound containing an active boron hydroxyl group is selected from at least one of the following: 4-nitrobenzeneboronic acid, 2-chlorophenylboronic acid, 3-chlorophenylboronic acid, isopropylboronic acid, 3-hydroxyphenylboronic acid, 4-iodophenylboronic acid, butylboronic acid, 4-vinylbenzeneboronic acid, 3-cyanophenylboronic acid, 3-hydroxymethylbenzeneboronic acid, phenethylboronic acid, 3-furanboronic acid, 8-quinolineboronic acid, but-3-eneboronic acid, 2-thiopheneboronic acid, p-methylphenylboronic acid, cyclohexylboronic acid, 2-pyridineboronic acid, 4-ethylphenylboronic acid, and 1-phenylvinylboronic acid.

4. The method for preparing a boron-containing oligomer according to any one of claims 1 to 3, characterized in that: The preparation method comprises: carrying out condensation reaction of small molecular alkoxysilane containing unsaturated bonds and a compound containing active boron hydroxyl groups to obtain the boron-containing oligomer.

5. The preparation method according to claim 4, characterized in that: In the preparation method, the molar ratio of the small molecule alkoxysilane containing unsaturated bonds to the compound containing active boron hydroxyl groups is 1:0.3-3. Preferably, a polycondensation catalyst is also added during the polycondensation reaction. Preferably, the condensation reaction temperature is 30-100°C. Preferably, the pressure of the reaction system of the condensation reaction is maintained at 0.01 MPa-2 MPa. Preferably, in order to promote the condensation reaction to proceed fully, the preparation method further comprises adding a solvent during the condensation reaction so that the entire reaction system is carried out in a solvent environment.

6. Use of the boron-containing oligomer according to any one of claims 1 to 3 in ageing-resistant addition silicone rubber.

7. An addition type silicone rubber composition, characterized in that: The addition silicone rubber composition comprises the following components: an addition silicone rubber base, a reinforcing filler, a tackifier and a catalyst, wherein the tackifier comprises the boron-containing oligomer according to any one of claims 1 to 3.

8. The addition type silicone rubber composition according to claim 7, characterized in that: The reinforcing filler is selected from vinyl MQ silicone resin. Preferably, the mass of the reinforcing filler is 30%-100% of the mass of the addition silicone rubber base. Preferably, the mass of the tackifier is 0.5%-3% of the mass of the addition silicone rubber base.

9. The addition type silicone rubber composition according to claim 7 or 8, characterized in that: The catalyst is selected from platinum catalysts. Preferably, the mass of the platinum catalyst is 0.5‰-2‰ of the mass of the addition silicone rubber base. Preferably, the addition type silicone rubber base comprises a mixture of vinyl terminated silicone oil and hydrogenated MQ silicone resin. Preferably, in the addition type silicone rubber base adhesive, the mass ratio of the vinyl-terminated silicone oil to the hydrogenated MQ silicone resin is 1-10:0.1-5.

10. A bonding sealant, characterized in that: The bonding sealant is prepared by the addition type silicone rubber composition according to any one of claims 7 to 9.

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