Adhesion promoter, preparation method thereof, silicon resin composition and application thereof

Abstract

The invention provides an adhesion promoter, a preparation method of the adhesion promoter, a silicon resin composition and application of the silicon resin composition. The adhesion promoter has a structure as shown in a formula I. The adhesion promoter is applied to a deoximation type moisture hardening silicon resin composition, the adhesion of the deoximation type moisture hardening silicon resin composition to base materials such as aluminum alloy, fluorocarbon spraying aluminum alloy and plastic which are difficult to adhere is effectively improved, the advantages of high curing speed and high stability in a humid environment of an oxime type adhesive are reserved, and meanwhile, due to the existence of polar hydroxyl, the deep curing depth is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to an adhesion promoter, a preparation method thereof, a silicone resin composition and application thereof. BACKGROUND

[0002] Room temperature vulcanized silicone rubber (RTV) has excellent resistance to ultraviolet light, weathering resistance and resistance to high temperature and humidity. Compared with other types of sealant, the durability of room temperature vulcanized silicone rubber sealant under harsh conditions is particularly outstanding, especially one-component room temperature vulcanized silicone sealant, which has excellent aging resistance due to the stability of the silicon-oxygen bond in its main component, and is widely used in the fields of building, automobile, lighting, electronics and electrical appliances.

[0003] Generally, ordinary RTV silicone rubber uses silane coupling agent as a tackifier, which has good adhesion to most substrates, but the adhesion effect to some difficult-to-adhere materials such as plastics is not ideal. In recent years, with the diversification of materials, the types and quantities of difficult-to-adhere materials are continuously expanding, so it is necessary to continuously develop specific tackifiers to improve the adhesion of RTV silicone rubber to difficult-to-adhere materials.

[0004] Silicone sealant includes dealcoholized silicone sealant and dealcoholized silicone sealant; wherein the dealcoholized silicone sealant usually uses titanium ester as a catalyst; the dealcoholized silicone sealant generally uses amino silane and / or epoxy silane as an adhesion promoter. Compared with dealcoholized silicone sealant, dealcoholized silicone sealant has better initial adhesion, but its adhesion to difficult-to-adhere substrates such as aluminum alloy, fluorocarbon sprayed aluminum alloy and plastic is also poor, and the adhesion range is also narrow.

[0005] Therefore, it is urgent to develop an adhesion promoter to improve the adhesion of dealcoholized moisture curing silicone resin composition to difficult-to-adhere aluminum materials, fluorocarbon sprayed substrates and plastics. SUMMARY

[0006] In view of the deficiencies in the prior art, the purpose of the present application is to provide an adhesion promoter, a preparation method thereof, a silicone resin composition and application thereof. The adhesion promoter is applied to dealcoholized moisture curing silicone resin composition, which effectively improves the adhesion of the composition to difficult-to-adhere substrates such as aluminum alloy, fluorocarbon sprayed aluminum alloy and plastic, retains the advantages of fast curing speed and high stability in humid environment of oxime type sealant, and increases the depth of deep curing due to the presence of polar hydroxyl groups.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides an adhesion promoter, which has the structure shown in Formula I.

[0009] Formula I.

[0010] In Formula I, is selected from ethylene or propylene.

[0011] each is independently selected from any one of H, C1-C6 linear or branched alkyl, HO-R-; and at least one of R1and R2is selected from HO-R-; R is selected from C1-C6 linear or branched alkylene.

[0012] each is independently selected from any one of C1-C6 linear or branched alkyl.

[0013] each is independently selected from any one of C1-C6 linear or branched alkyl, at least one of R1and R2is selected from or ; each is independently selected from any one of C1-C6 linear or branched alkyl. is selected from ethylene or propylene. each is independently selected from any one of H, C1-C6 linear or branched alkyl, HO-R-; and at least one of R1and R2is selected from ; is selected from C1-C6 linear or branched alkylene.

[0014] “ ” represents a point of attachment.

[0015] the dashed line represents a coordination bond between N and Ti.

[0016] ​​​​​​​​​​​​In this invention, the adhesion promoter contains specific siloxane groups, which makes the solubility parameters of the adhesion promoter more compatible with the silicone resin system, thus improving its compatibility with silicone resin, preventing migration and precipitation, and improving adhesion durability. It also contains hydroxyl groups, which promote deep curing of the moisture-curing silicone resin composition and improve the shelf life of the deoxime-type moisture-curing silicone resin composition. Furthermore, it contains titanate fragments, which increase the adhesion of the moisture-curing silicone resin composition to difficult-to-bond substrates such as aluminum alloys, fluorocarbon-coated aluminum alloys, and plastics. Therefore, by using an adhesion promoter with a specific structure in the deoxime-type moisture-curing silicone resin composition, its adhesion to difficult-to-bond substrates such as aluminum alloys, fluorocarbon-coated aluminum alloys, and plastics is effectively improved. Simultaneously, it exhibits good stability and maintains good adhesion performance even in humid environments and after ultraviolet irradiation.

[0017] In this invention, C1-C6 straight-chain or branched alkylene refers to straight-chain or branched alkylene with 1-6 carbon atoms, such as C1, C2, C3, C4, C5, and C6 straight-chain or branched alkylene, including but not limited to methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, tert-butylene, n-pentylene, and n-hexylene; the same expressions in the following text have the same meaning.

[0018] In this invention, C1-C6 straight-chain or branched alkyl refers to a straight-chain or branched alkyl with 1 to 6 carbon atoms. For example, it can be a C1, C2, C3, C4, C5, or C6 straight-chain or branched alkyl, including but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, etc. In the following text, the same expression means the same meaning.

[0019] In this invention, "in "" indicates a connection site, meaning that Si is connected to O through a single bond.

[0020] Preferably, the adhesion promoter has the structure shown in Formula I-1.

[0021] Formula I-1.

[0022] In Equation I-1, , Each is independently selected from ethylidene or propyleneide.

[0023] , , , Each is independently selected from H, C1-C6 straight-chain or branched alkyl groups, HO-R-, and any one of them; and , At least one of them is selected from HO-R-; , at least one of R1and R2is selected from HO-R-; R is selected from C1-C6 linear or branched alkylene.

[0024] , , each independently is selected from any one of C1-C6 linear or branched alkyl.

[0025] selected from any one of C1-C6 linear or branched alkyl, , ; , , each independently is selected from any one of C1-C6 linear or branched alkyl; selected from ethylene or propylene; , each independently is selected from any one of C1-C6 linear or branched alkyl, HO-R-; and , at least one of R1and R2is selected from ; selected from C1-C6 linear or branched alkylene; " represents a linking site; the dotted line represents a coordination bond formed between N and Ti. Preferably, the adhesion promoter has any one of the following structures.

[0026]

[0027] Formula I-1-1; Formula I-1-2. in Formula I-1-1,

[0028] , , , , , , , , , each independently is selected from the same defined range as Formula I-1; selected from C1-C6 linear or branched alkyl.

[0029] in Formula I-1-2, , , , , , , , , each independently selected from the same defined range as Formula I-1; 、 、 each independently selected from any one of C1-C6 linear or branched alkyl.

[0030] Preferably, the adhesion promoter comprises at least one of the following compounds: 、 、 、 each independently selected from HO-R-, R selected from C1-C6 linear or branched alkylene.

[0031] Preferably, the adhesion promoter comprises at least one of the following compounds:

[0032] 、 、 、 .

[0033] In a second aspect, the present application provides a method for preparing the adhesion promoter according to the first aspect, the method comprising the following steps:

[0034] (1) reacting a tetraalkyl titanate with an acyloxyalkylsilane to obtain a first reactant;

[0035] (2) reacting the first reactant with an alcohol amine compound to obtain the adhesion promoter; the alcohol amine compound has a number of hydroxyl groups ≥ 2, for example, 2, 3, 4, 5, 6, etc.

[0036] Preferably, the molar ratio of the tetraalkyl titanate, the acyloxytrialkylsilane and the trialkyl alcohol amine is 1:(1-2):(1-3), wherein the specific value of (1-2) can be, for example, 1, 1.2, 1.4, 1.6, 1.8, etc.; the specific value of (1-3) can be, for example, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3; more preferably 1:(1-2):(1.5-2.5).

[0037] In the present application, the alkyl group in the tetraalkyl titanate is selected from C1-C6 linear or branched alkyl.

[0038] Preferably, the tetraalkyl titanate comprises at least one of tetraisopropyl titanate, tetraethyl titanate.

[0039] Preferably, the acyloxyalkylsilane comprises at least one of acetyloxytrimethylsilane, acetyloxytriethylsilane.

[0040] Preferably, the alcohol amine compound comprises at least one of triethanolamine, N-methyldiethanolamine, hydroxyethyldiisopropanolamine.

[0041] Preferably, the reaction in step (1) and the reaction in step (2) are each independently carried out in the presence of a protective atmosphere.

[0042] Preferably, the protective atmosphere comprises nitrogen.

[0043] Preferably, the reaction in step (1) is carried out at a temperature of 20-60℃, for example, at 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, or the like; and the reaction is carried out for a time period of 1-6h, for example, for 1h, 2h, 3h, 4h, 5h, 6h, or the like.

[0044] Preferably, the reaction in step (2) is carried out at a temperature of 20-50℃, for example, at 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, or the like; and the reaction is carried out for a time period of 2-6h, for example, for 2h, 3h, 4h, 5h, 6h, or the like.

[0045] In the present application, after the reaction in step (2) is completed, a post-treatment step is further included; the post-treatment comprises vacuum distillation; the vacuum distillation is carried out at a temperature of 70-90℃, at a pressure of -0.09--0.1MPa, and for a time period of 30-60min.

[0046] In a third aspect, the present application provides a silicone composition comprising, in parts by weight, 100 parts of a first polydimethylsiloxane, 5-15 parts of a second polydimethylsiloxane, 1-10 parts of a crosslinking agent, 5-100 parts of a filler, 1-30 parts of a plasticizer, 0.1-5 parts of an adhesion promoter, 0-5 parts of a coupling agent, and 0-5 parts of a catalyst; the adhesion promoter comprises the adhesion promoter according to the first aspect.

[0047] In the present application, the 5-15 parts of the second polydimethylsiloxane can be, for example, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts, or the like.

[0048] In the present application, the 1-10 parts of the crosslinking agent can be, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, or the like.

[0049] In the present application, the 5-100 parts of the filler can be, for example, 5 parts, 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, 95 parts, or the like.

[0050] In the present application, 1-30 parts of the plasticizer, for example, can be 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, etc.

[0051] In the present application, 0.1-5 parts of the adhesion promoter, for example, can be 0.1 part, 0.5 part, 1 part, 1.5 part, 2 part, 2.5 part, 3 part, 3.5 part, 4 part, 4.5 part, 4.8 part, etc.

[0052] In the present application, 0-5 parts of the coupling agent, for example, can be 0.1 part, 0.5 part, 1 part, 1.5 part, 2 part, 2.5 part, 3 part, 3.5 part, 4 part, 4.5 part, 4.8 part, etc.; to reduce the cost of the silicone sealant, more preferably 0.1-5 parts.

[0053] In the present application, 0-5 parts of the catalyst, for example, can be 0.1 part, 0.5 part, 1 part, 1.5 part, 2 part, 2.5 part, 3 part, 3.5 part, 4 part, 4.5 part, 4.8 part, etc.

[0054] Preferably, the first polydimethylsiloxane includes at least one of alpha, omega-dihydroxypolydimethylsiloxane, methyl dimethoxy terminated polydimethylsiloxane.

[0055] Preferably, the first polydimethylsiloxane has a viscosity of 1000-150000 mPa•s at 25℃, for example, can be 1000 mPa•s, 2000 mPa•s, 5000 mPa•s, 10000 mPa•s, 20000 mPa•s, 50000 mPa•s, 100000 mPa•s, 120000 mPa•s, 140000 mPa•s, etc.

[0056] Preferably, the second polydimethylsiloxane has a viscosity of 100-1000 mPa•s at 25℃, for example, can be 150 mPa•s, 200 mPa•s, 250 mPa•s, 300 mPa•s, 350 mPa•s, 400 mPa•s, 450 mPa•s, 500 mPa•s, 550 mPa•s, 600 mPa•s, 650 mPa•s, 700 mPa•s, 750 mPa•s, 800 mPa•s, 850 mPa•s, 900 mPa•s, 950 mPa•s, etc.

[0057] In the present application, the second polydimethylsiloxane is dimethyl silicone oil.

[0058] Preferably, the crosslinking agent includes a ketoxime silane crosslinking agent.

[0059] Preferably, the ketoximosilane crosslinking agent comprises at least one of methyltributylketoximosilane, vinyltributylketoximosilane, tetrabutylketoximosilane.

[0060] Preferably, the filler comprises at least one of calcium carbonate, diatomite, quartz sand, white carbon black.

[0061] In the present application, the filler comprises a filler treated with stearic acid; the particle size of the filler is 0.04-0.1 μm, for example, it can be 0.04 μm, 0.06 μm, 0.08 μm, 0.1 μm, etc.

[0062] Preferably, the plasticizer comprises at least one of alkyl aromatic hydrocarbon, mineral oil, dimethyl silicone oil.

[0063] Preferably, the coupling agent comprises at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane (glycidyl ether propyl trimethoxysilane), γ-mercaptopropyltrimethoxysilane.

[0064] Preferably, the catalyst comprises an organic tin catalyst.

[0065] Preferably, the organic tin catalyst comprises at least one of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, dibutyltin acetylacetate.

[0066] In the present application, the preparation method of the silicone resin comprises: uniformly mixing the components, defoaming, to obtain the silicone resin composition.

[0067] In the present application, the silicone resin composition is a deoxime type moisture curing silicone resin composition (or a deoxime type moisture curing silicone resin composition).

[0068] In a fourth aspect, the present application provides a sealant comprising the adhesion promoter of the first aspect or comprising the silicone resin composition of the third aspect.

[0069] In the present application, the sealant can be used for bonding of difficult-to-bond materials (such as aluminum alloy, fluorocarbon spray aluminum alloy, plastic, etc.).

[0070] The numerical ranges recited in the present application include not only the point values listed explicitly, but also any intervening point values between the recited values. Due to the limitations of space and for the sake of simplicity, the present application does not exhaustively list the specific point values included in the ranges.

[0071] Compared with the prior art, the present application has the following beneficial effects:

[0072] (1) The adhesion promoter provided by the present application is applied to a de-oxime type moisture curing silicone resin composition, compared with a traditional titanate coupling agent, because of containing suitable siloxane groups, the solubility parameter matches the silica system, so that the compatibility with the organic silicon system is good, there is no migration and precipitation, the adhesion durability is improved; meanwhile, the polar hydroxyl group promotes the deep curing of the moisture curing silicone resin composition, improves the storage period of the de-oxime type moisture curing silicone resin composition; in addition, the titanate fragment increases the adhesion of the moisture curing silicone resin composition with difficult-to-adhere aluminum alloy, fluorocarbon spraying, plastic and other substrates.

[0073] (2) The adhesion promoter provided by the present application contains titanate, siloxane and alcohol amine units at the same time, can be applied to silicone sealant, acrylic resin, epoxy resin, polyurethane adhesive and other products, and has a wide application range.

[0074] (3) The adhesion promoter provided by the present application has a simple preparation method, can be prepared by one-pot two-step reaction, and the raw materials are easy to obtain, and the product purification is simple and easy to operate. DETAILED DESCRIPTION

[0075] The technical solutions of the present application are further illustrated by specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0076] Example 1

[0077] The adhesion promoter provided by the present application has the structure of The preparation method of the adhesion promoter comprises the following steps:

[0078] 284.2g of titanium tetraisopropylate is added into a four-necked flask equipped with a thermometer, a dropping funnel, a mechanical stirrer and a condenser, and stirring is started, and then 132g of acetoxytrimethylsilane is added dropwise into the flask at a temperature not higher than 60℃, the dropping time is 30min, after the dropping is completed, the reaction is carried out at 35℃ for 3h. Then 298.4g of triethanolamine is added dropwise into the flask at 25℃ (the dropping time is 1h), after the dropping is completed, the reaction is carried out at 25℃ for 3h, and then low boiling point substances are removed by distillation under reduced pressure (80℃, -0.095MPa, 60min), to obtain the adhesion promoter, which is recorded as TS-1.

[0079] Example 2

[0080] The adhesion promoter provided by the present application has the structure of The preparation method of the adhesion promoter comprises the following steps:

[0081] Into a four-necked flask equipped with a thermometer, a dropping funnel, a mechanical stirrer, and a condenser, 284.2 g of tetraisopropyl titanate was added, and stirring was started. Then, 264 g of acetoxytrimethylsilane was added dropwise at a temperature of not more than 60°C over a period of 30 min. After the addition was completed, the reaction was continued at 45°C for 4 h. Subsequently, 298.4 g of triethanolamine was added dropwise at 25°C over a period of 1 h, and the reaction was continued at 25°C for 3 h. Then, low-boiling substances were removed by distillation under reduced pressure (80°C, -0.095 MPa, 60 min) to obtain the adhesion promoter, which is referred to as TS-2.

[0082] Example 3

[0083] This example provides an adhesion promoter, the structure of which is ; in the preparation method, tetraisopropyl titanate is replaced with tetraethyl titanate in an equal molar amount, acetoxytrimethylsilane is replaced with acetoxytriethylsilane in an equal molar amount, and triethanolamine is replaced with hydroxyethyldiisopropyl ethanolamine in an equal molar amount, and the other parameters are the same as in Example 1.

[0084] Example 4

[0085] This example provides an adhesion promoter, the structure of which is ; in the preparation method, the difference from Example 1 is that the mass of acetoxytrimethylsilane and triethanolamine is adjusted so that the molar ratio of tetraisopropyl titanate, acetoxytrimethylsilane, and triethanolamine is 1:2:1, and the other parameters are the same as in Example 1.

[0086] Example 5

[0087] This example provides an adhesion promoter, the structure of which is ; in the preparation method, the difference from Example 1 is that the mass of triethanolamine is adjusted so that the molar ratio of tetraisopropyl titanate, acetoxytrimethylsilane, and triethanolamine is 1:1:3, and the other parameters are the same as in Example 1.

[0088] Comparative Example 1

[0089] This comparative example provides an adhesion promoter, the preparation method of which is different from Example 1 in that acetoxytrimethylsilane is not used in the raw materials, and the other raw materials and process parameters are the same as in Example 1.

[0090] Comparative Example 2

[0091] This comparative example provides an adhesion promoter, the preparation method of which is different from Example 1 in that triethanolamine is not used in the raw materials, and the other raw materials and process parameters are the same as in Example 1.

[0092] Comparative Example 3

[0093] The present comparative example provides an adhesion promoter, which is isopropyl tris(dioctylpyrophosphato) titanate.

[0094] Comparative Example 4

[0095] The present comparative example provides an adhesion promoter, which is a mixture of aminopropyl triethoxysilane and glycidyl ether propyl trimethoxysilane in a mass ratio of 3:1.

[0096] Application Example 1

[0097] The present application example provides a silicone resin composition, which comprises 100 parts of α, ω-dihydroxypolydimethylsiloxane having a viscosity of 20000 mPa•s at 25℃, 9.1 parts of dimethyl silicone oil having a viscosity of 350 cps at 25℃, 66.7 parts of calcium carbonate treated with 2.0 wt% stearic acid (D50 particle size 0.06 μm, purchased from Warner New Material), 5 parts of methyltris(butanone oxime) silane, 1.67 parts of vinyltris(butanone oxime) silane, 0.67 parts of γ-aminopropyl trimethoxysilane, 0.33 parts of glycidyl ether propyl trimethoxysilane, 0.5 parts of adhesion promoter TS-1 (Example 1), and 0.17 parts of dibutyltin dilaurate.

[0098] The preparation method of the silicone resin composition comprises: defoaming and mixing α, ω-dihydroxypolydimethylsiloxane, dimethyl silicone oil, calcium carbonate treated with 2.0 wt% stearic acid, methyltris(butanone oxime) silane, vinyltris(butanone oxime) silane, γ-aminopropyl trimethoxysilane, glycidyl ether propyl trimethoxysilane, adhesion promoter TS-1 (Example 1), and dibutyltin dilaurate in a universal mixer to obtain the silicone resin composition.

[0099] Application Example 2

[0100] The present application example provides a silicone resin composition, which is different from Application Example 1 in that adhesion promoter TS-1 is replaced by equal mass of adhesion promoter TS-2 provided in Example 2, and other components, amounts and preparation methods are the same as those in Application Example 1.

[0101] Application Examples 3-5

[0102] The present application examples respectively provide a silicone resin composition, which is different from Application Example 1 in that adhesion promoter TS-1 is replaced by equal mass of adhesion promoter provided in Examples 3-5, and other components, amounts and preparation methods are the same as those in Application Example 1.

[0103] Application Example 6

[0104] The application example provides a kind of silicone resin composition, including 100 parts α, ω-dihydroxy polydimethylsiloxane at 25 ℃ The viscosity is 20000 mPa · s, 6 parts dimethyl silicone oil at 25 ℃ The viscosity is 350 cps, 5 parts calcium carbonate (D50 particle size 0.06 μm, purchased from Warner New Material) treated with 2.0 wt% stearic acid, 2 parts methyl tributyl ketoxime silane, 1 part vinyl tributyl ketoxime silane, 2 parts γ-aminopropyl trimethoxysilane, 0.5 parts glycidyl ether propyl trimethoxysilane, 2 parts adhesion promoter TS-1 (example 1) and 0.5 parts dibutyltin dilaurate, the preparation method is same with application example 1.

[0105] Application example 7

[0106] The application example provides a kind of silicone resin composition, 100 parts α, ω-dihydroxy polydimethylsiloxane at 25 ℃ The viscosity is 20000 mPa · s, 12 parts dimethyl silicone oil at 25 ℃ The viscosity is 350 cps, 100 parts calcium carbonate (D50 particle size 0.06 μm, purchased from Warner New Material) treated with 2.0 wt% stearic acid, 7 parts methyl tributyl ketoxime silane, 1.8 parts vinyl tributyl ketoxime silane, 2.65 parts γ-aminopropyl trimethoxysilane, 1.35 parts glycidyl ether propyl trimethoxysilane, 5 parts adhesion promoter TS-1 (example 1) and 1 parts dibutyltin dilaurate, the preparation method is same with application example 1.

[0107] Comparative application example 1-4

[0108] Respectively provide a kind of silicone resin composition, which is different from application example 1, adhesion promoter TS-1 is replaced by the adhesion promoter provided in comparative example 1-4 with equal mass, other components, dosage and preparation method are same with application example 1.

[0109] Comparative application example 5

[0110] Provide a kind of silicone resin composition, which is different from application example 1, without adhesion promoter, other components, dosage and preparation method are same with application example 1.

[0111] Performance test

[0112] The preparation and maintenance of test sample:

[0113] Silicone resin composition is prepared according to the method provided in chapter 7 of GB / T13477.8-2002 H type adhesive test piece, vulcanization maintenance 7 days in temperature (23±2) ℃, relative humidity (50±5) % environment, carries out following performance test.

[0114] The treatment and performance test of adhesive test piece:

[0115] The test piece is placed in a water-ultraviolet test box for a certain period of time according to the method provided in GB / T 14683-2017, or taken out after being soaked in water at (23±2) °C for a certain period of time, and then placed for 24 h under standard conditions (23±2 °C, 50% humidity), and then the tensile bonding strength test is carried out and the bonding failure area is recorded.

[0116] The test method of the curing depth is as follows:

[0117] The silicone compositions provided in the application examples and the comparative application examples are placed in a mold, leveled, so that the silicone compositions form a right-angle shape, placed for 24 h under standard conditions (23±2 °C, 50% humidity), cut down along the vertical long side with a craft knife until there is an uncured glue position, and the thickness of the cured glue layer is measured, which is the 24 h curing depth.

[0118] Taking the silicone compositions provided in the application examples 1, 2 and the comparative application example 5 as examples, the specific test results of the bonding properties to different substrates are shown in Table 1; in Table 1, Tmax represents the maximum tensile strength, with the unit of MPa; CF represents the cohesive failure area, with the unit of %; the initial is the initial bonding property of the silicone composition to the corresponding substrate; the dyne value of anodic aluminum is 24-28.

[0119] Table 1

[0120]

[0121] Taking the fluorocarbon sprayed aluminum plate substrate as an example, the bonding properties of the silicone compositions provided in the application examples 3-7 and the comparative application examples 1-4 are shown in Table 2.

[0122] Table 2

[0123]

[0124] As shown in Table 1 and Table 2, the 24 h curing depth reaches more than 3.0 mm by using the silicon-based modified titanium acid ester containing active hydroxyl groups as the adhesion promoter, which effectively improves the deep curing speed of the system. The silicon-based modification can effectively improve the adhesion of the adhesion promoter to the fluorocarbon sprayed aluminum plate, anodic aluminum, PA and other difficult-to-stick substrates, and the change amount of the bonding failure area is less than 5% after the initial, 28 days of 23 °C water immersion and 168 h of 45 °C water-ultraviolet treatment, and the retention rate of the tensile strength Tmax after aging is higher than 85%.

[0125] As shown in the comparative application examples 1-4, the silicone compositions obtained by using the adhesion promoters with the specific structure and kind of the application have small curing depth and / or poor bonding properties after 28 days of 23 °C water immersion and 168 h of 45 °C water-ultraviolet treatment.

[0126] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above-described specific embodiments are merely examples of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An adhesion promoter characterized by comprising: The adhesion promoter has a structure shown in Formula I; Formula I; in formula I, is selected from ethylene or propylene; , each independently is selected from H, C1-C6 straight chain or branched alkyl, any one of HO-R-; and , at least one of R1and R2is selected from HO-R-; R is selected from C1-C6 straight chain or branched alkylene; , , each is independently selected from any one of C1-C6linear or branched alkyl; 、 each independently selected from any one of C1-C6 linear or branched alkyl, 、 ; and 、 at least one of R1and R2is selected from or ; 、 、 each independently selected from any one of C1-C6 linear or branched alkyl; is selected from ethylene or propylene; 、 each independently selected from any one of C1-C6 linear or branched alkyl, HO-R-; and 、 at least one of R1and R2is selected from ; is selected from C1-C6 linear or branched alkylene; " indicates a connection site;​ The dotted line represents a coordination bond formed between N and Ti.

2. The adhesion promoter according to claim 1, characterized in that The adhesion promoter has a structure shown in Formula I-1; Formula I-1; In formula I-1, , each independently is selected from ethylene or propylene; 、 、 、 each is independently selected from H, C1-C6 straight chain or branched alkyl, HO-R-; 、 at least one of R1and R2is selected from HO-R-; 、 at least one of R1and R2is selected from HO-R-; R is selected from C1-C6 straight chain or branched alkylene; , , each is independently selected from any one of C1-C6linear or branched alkyl; any one selected from the group consisting of C1-C6 linear or branched alkyl, , any one selected from the group consisting of C1-C6 linear or branched alkyl, , , each independently selected from any one of C1-C6 linear or branched alkyl; selected from ethylene or propylene; , each independently selected from any one of C1-C6 linear or branched alkyl, HO-R-; and , at least one of ; selected from C1-C6 linear or branched alkylene; " indicates a point of attachment; the dotted line indicates a coordination bond formed between N and Ti.

3. The adhesion promoter according to claim 2, characterized in that The adhesion promoter has any one of the following structures: Formula I-1-1; Formula I-1-2; in formula I-1-1, , , , , , , , , each independently is selected from the same defined range as formula I-1 ; is selected from C1-C6 linear or branched alkyl; in formulae I-1-2, , , , , , , , , each independently is selected from the same defined range as in formula I-1 ; , , each independently is selected from any one of C1-C6 linear or branched alkyl.

4. The adhesion promoter according to claim 3, characterized in that The , , , each independently is selected from HO-R-, R is selected from C1-C6 straight chain or branched alkylene.

5. The adhesion promoter according to any one of claims 1 to 4, characterized in that, The adhesion promoter comprises at least one of the following compounds: 、 、 、 。 6. A process for producing the adhesion promoter according to any one of claims 1 to 5, characterized by, The preparation method comprises the following steps: (1) reacting tetraalkyl titanate with acyloxyalkyl silane to obtain a first reactant; (2) reacting the first reactant with an alcohol amine compound to obtain the adhesion promoter; the alcohol amine compound has a number of hydroxyl groups ≥ 2.

7. The production method according to claim 6, characterized by, The molar ratio of the tetraalkyl titanate, the acyloxyalkyl silane and the alcohol amine compound is 1:(1-2):(1-3); Preferably, the tetraalkyl titanate comprises at least one of tetraisopropyl titanate and tetraethyl titanate; Preferably, the acyloxyalkyl silane comprises at least one of acetyloxytrimethylsilane and acetyloxytriethylsilane; Preferably, the alcohol amine compound comprises at least one of triethanolamine, N-methyldiethanolamine and hydroxyethyldiisopropanolamine; Preferably, the reaction in step (1) and the reaction in step (2) are each independently carried out in the presence of a protective atmosphere; Preferably, the protective atmosphere comprises nitrogen; Preferably, the reaction in step (1) is carried out at a temperature of 20-60℃ and for a time of 1-6h; Preferably, the reaction in step (2) is carried out at a temperature of 20-50℃ and for a time of 2-6h.

8. A silicone composition characterized in that, The silicone composition comprises, in parts by weight, 100 parts of first polydimethylsiloxane, 5-15 parts of second polydimethylsiloxane, 1-10 parts of crosslinking agent, 5-100 parts of filler, 1-30 parts of plasticizer, 0.1-5 parts of adhesion promoter, 0-5 parts of coupling agent and 0-5 parts of catalyst; the adhesion promoter comprises the adhesion promoter according to any one of claims 1-5.

9. The silicone composition of claim 8, wherein The first polydimethylsiloxane comprises at least one of a dihydroxypolydimethylsiloxane, a methyldimethoxy terminated polydimethylsiloxane; Preferably, the first polydimethylsiloxane has a viscosity of 1000-150000 mPa•s at 25℃; Preferably, the second polydimethylsiloxane has a viscosity of 100-1000 mPa•s at 25℃; Preferably, the crosslinking agent comprises a ketoximosilane crosslinking agent; Preferably, the ketoximosilane crosslinking agent comprises at least one of methyltributylketoximosilane, vinyltributylketoximosilane and tetrabutylketoximosilane; Preferably, the filler comprises at least one of calcium carbonate, diatomite, quartz sand and white carbon black; Preferably, the plasticizer comprises at least one of alkyl aromatic hydrocarbon, mineral oil and dimethyl silicone oil; Preferably, the coupling agent comprises at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane; Preferably, the catalyst comprises an organic tin catalyst; Preferably, the organic tin catalyst comprises at least one of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate and dibutyltin acetylacetate.

10. A sealant, characterized by, The sealant includes the adhesion promoter according to any one of claims 1 to 5 or includes the silicone composition according to any one of claims 8 to 9. The sealant includes the adhesion promoter according to any one of claims 1 to 5 or includes the silicone composition according to any one of claims 8 to 9.

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