Catalytic system and two-component dealcoholization type organic silicon adhesive

Abstract

The invention relates to the technical field of organic silicon adhesives, and provides a catalytic system and a bi-component dealcoholization type organic silicon adhesive, the catalytic system comprises a condensation reaction between silanol and a siloxane cross-linking agent, and tert-butyl imino-tris (pyrrolidinyl) phosphine for increasing the condensation reaction rate. Wherein tert-butyl imino-tris (pyrrolidinyl) phosphazene is used as a non-coordination proton transfer accelerant to promote the action process of an organic tin / titanium complex catalytic system and realize the synergistic interaction of the three, so that the catalytic activity is remarkably promoted. When being used in a two-component dealcoholization type organic silicon adhesive, the epoxy resin can obviously shorten the surface drying time, realizes rapid curing, and enables siloxane chain segments to form a compact and uniform cross-linked network, thereby obtaining excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and more particularly to a catalytic system and a two-component de-alcoholized silicone adhesive. Background Technology

[0002] Silicone rubber adhesives are among the most widely used organosilicon products. Before vulcanization, silicone rubber is a high-molecular-weight polysiloxane; after vulcanization, it exhibits a highly elastic network structure. The superior performance of silicone rubber stems from the chemical structure of the linear siloxane before vulcanization, namely the abundant silicon-oxygen bonds (Si-O-Si), which provide excellent temperature resistance, high electrical conductivity, weather resistance, and solvent resistance. It is widely used in electronic device housings, aerospace, and medical and health fields. Organosilicon adhesives can be classified into single-component and two-component adhesives based on their components. Two-component adhesives, due to their longer shelf life, faster curing rate, and better mechanical properties, are widely used in specific scenarios requiring rapid bonding.

[0003] Two-component condensation-type room temperature vulcanizing silicone adhesives are the most common type of two-component silicone adhesive, typically used as adhesives in building materials and electronic component housings. In application, AB adhesives are mixed in a specific ratio and applied between two components, where they rapidly cure and cross-link under the action of a catalyst. However, there is still room for improvement in the curing speed, surface drying time, and mechanical properties of current room temperature curing two-component dealcoholized silicone adhesives. Summary of the Invention

[0004] Research has found that the core reason why it is difficult to simultaneously achieve optimal surface drying time and mechanical properties in room-temperature curing two-component dealcoholized silicone adhesives is largely due to the unsatisfactory performance of existing catalyst systems. Among these, dibutyltin dilaurate is the most widely used and technologically mature organotin catalyst in room-temperature curing silicone rubber catalytic systems. Experiments have shown that simply adjusting the amount of dibutyltin dilaurate is insufficient to significantly increase the curing speed while simultaneously maintaining the adhesive's mechanical properties.

[0005] Based on this, this invention utilizes tert-butylimino-tris(pyrrolidinyl)phosphine in a two-component dealcoholized silicone adhesive, designing a novel two-component dealcoholized silicone adhesive and its preparation method. By employing tert-butylimino-tris(pyrrolidinyl)phosphine in combination with other catalysts, a novel catalytic system is constructed through a condensation reaction involving silanols and siloxane crosslinking agents. This significantly shortens surface drying time, achieving rapid curing while simultaneously obtaining excellent mechanical properties and facilitating application and production. Furthermore, to ensure that the silicone rubber possesses both good processability and good mechanical properties, the silanol selected in this invention is a mixture of a first viscosity fraction and a second viscosity fraction.

[0006] This invention proposes a catalytic system comprising a condensation reaction between silanol and a siloxane crosslinking agent, and a tert-butylimino-tris(pyrrolidinyl)phosphine to enhance the rate of the condensation reaction.

[0007] In the catalytic system provided by the present invention, the silanol is selected from α,ω-dihydroxypolydimethylsiloxane.

[0008] And / or, the siloxane crosslinking agent is selected from one or more combinations of methyltrimethoxysilane, methyltriethoxysilane, and tetra-n-butylsilane.

[0009] According to the catalytic system provided by the present invention, the catalytic system further includes a metal-based catalyst; Preferably, the metal-based catalyst includes an organotitanium catalyst and / or an organotin catalyst.

[0010] According to the catalytic system provided by the present invention, the mass ratio of the tert-butylimino-tris(pyrrolidinyl)phosphine to the metal-based catalyst is 1:(7~15).

[0011] According to the catalytic system provided by the present invention, the catalytic system further includes: a coupling agent; Preferably, the coupling agent is selected from one or a combination of two or more of γ-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0012] According to the catalytic system provided by the present invention, the catalytic system further includes: a filler; preferably, the filler is selected from nano-calcium carbonate.

[0013] According to the catalytic system provided by the present invention, the catalytic system further includes: a lubricant; the lubricant is selected from dimethyl silicone oil.

[0014] The present invention also provides a two-component dealcoholized silicone adhesive, comprising: the catalyst system described above.

[0015] According to the two-component de-alcoholized silicone adhesive provided by the present invention, the surface drying time of the two-component de-alcoholized silicone adhesive is less than or equal to 5 minutes, preferably 3 to 5 minutes.

[0016] According to the two-component de-alcoholized silicone adhesive provided by the present invention, the base material of the two-component de-alcoholized silicone adhesive includes silanol, optional filler and lubricant.

[0017] The two-component de-alcoholized silicone adhesive provided by the present invention comprises component A and component B; Component A includes silanol, optional filler, lubricant, siloxane crosslinking agent, and optional coupling agent; Component B includes silanol, optional filler, lubricant, tert-butylimino-tris(pyrrolidinyl)phosphine, and metal-based catalyst.

[0018] The present invention provides a catalytic system and a two-component dealcohol-type organosilicon adhesive. From the perspective of catalyst system optimization, it was found that the catalytic composition of tert-butylimino-tris(pyrrolidinyl)phosphine, organotitanium catalyst, and organotin catalyst can improve the condensation reaction rate between silanol and siloxane crosslinking agent. At the same time, by optimizing other conditions, it is possible to significantly shorten the surface drying time, achieve rapid curing, and at the same time enable the siloxane segments to form a dense and uniform crosslinking network, thereby obtaining excellent mechanical properties and avoiding the viscosity from remaining relatively stable and moderate, which is easy to apply and produce.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0020] The embodiments of the present invention will be described in further detail below with reference to examples. These examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0021] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0022] In a specific embodiment of the present invention, a catalytic system is provided, comprising a condensation reaction between silanol and a siloxane crosslinking agent, and a tert-butylimino-tris(pyrrolidinyl)phosphine to enhance the rate of the condensation reaction.

[0023] Research has found that using tert-butylimino-tris(pyrrolidinyl)phosphine (t-Bu-P4) as a novel non-coordinate proton transfer promoter can utilize its strong basicity (pKa ~42.7) and unique non-coordinate properties to efficiently capture protons from silanol substrates in organosilicon curing systems, instantaneously generating highly reactive silanol anions, thereby significantly accelerating the proton transfer process, which is often the rate-determining step in the catalytic cycle.

[0024] Preferably, in the catalytic system, the mass ratio of the tert-butylimino-tris(pyrrolidinyl)phosphine to the silanol is (2~4):500; for example, it can be any value or a numerical range composed of any values ​​among 2.0:500, 2.5:500, 3.0:500, 3.5:500, 4.0:500.

[0025] Preferably, in the catalytic system, the mass ratio of the siloxane crosslinking agent to the silanol is (20~30):200. For example, it can be any value or a range of values ​​from 20:200, 22:200, 24:200, 26:200, 28:200, 30:200.

[0026] In some specific embodiments of the present invention, the silanol is selected from α,ω-dihydroxypolydimethylsiloxane.

[0027] In some specific embodiments of the present invention, the siloxane crosslinking agent is selected from one or a combination of two or more of methyltrimethoxysilane, methyltriethoxysilane, and tetra-n-butylsilane. Different siloxane crosslinking agents have different effects on the mechanical properties of the catalyzed material, with methyltrimethoxysilane showing the best effect.

[0028] In some specific embodiments of the present invention, the silanol includes a silanol of first viscosity and a silanol of second viscosity; the viscosity of the silanol of first viscosity is higher than the viscosity of the silanol of second viscosity.

[0029] In some specific embodiments of the present invention, the viscosity of the first viscosity silanol is 70,000 to 90,000 mPa·s. For example, it can be any value or a range of values ​​among 70,000 mPa·s, 75,000 mPa·s, 80,000 mPa·s, 85,000 mPa·s, and 90,000 mPa·s.

[0030] In some specific embodiments of the present invention, the viscosity of the second viscosity silanol is 8000~12000 mPa·s. For example, it can be any value or a range of values ​​among 8000 mPa·s, 9000 mPa·s, 10000 mPa·s, 11000 mPa·s, and 12000 mPa·s.

[0031] In some specific embodiments of the present invention, in the catalytic system, the mass ratio of the silanol with the first viscosity to the silanol with the second viscosity is (0.8~1.2):1. For example, it can be any value or a range of values ​​from 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1.

[0032] In some specific embodiments of the present invention, the catalytic system further includes a metal-based catalyst; In some specific embodiments of the present invention, the metal-based catalyst includes organotitanium catalysts and / or organotin catalysts.

[0033] In some specific embodiments of the present invention, in the catalytic system, the mass ratio of the metal-based catalyst to the silanol is (2.5~3.5):50; for example, it can be any value or a numerical range composed of any values ​​among 2.5:50, 2.7:50, 2.9:50, 3.1:50, 3.3:50, and 3.5:50.

[0034] In some specific embodiments of the present invention, the organotin catalyst is selected from dibutyltin dilaurate.

[0035] In some specific embodiments of the present invention, the organotitanium catalyst is selected from one or more combinations of tetrabutyl titanate, 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate, and tetraisopropyl titanate.

[0036] In some specific embodiments of the present invention, the mass ratio of the tert-butylimino-tris(pyrrolidinyl)phosphine to the metal-based catalyst is 1:(7~15). For example, it can be any value or a numerical range composed of any values ​​from 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15.

[0037] In some specific embodiments of the present invention, the mass ratio of tert-butylimino-tris(pyrrolidinyl)phosphine to organotitanium catalyst is (2~4):20; for example, it can be any value or a numerical range composed of any values ​​among 2.0:20, 2.5:20, 3.0:20, 3.5:20, 4.0:20.

[0038] In some specific embodiments of the present invention, the mass ratio of tert-butylimino-tris(pyrrolyl)phosphine to dibutyltin dilaurate is (2~4):10. For example, it can be any value among 2:10, 3:10, 4:10, or any numerical range of values.

[0039] While maintaining rapid curing, this invention also optimizes the types and amounts of reinforcing materials and coupling agents, enabling the mechanical properties of the catalyzed material system to reach a high level.

[0040] In some specific embodiments of the present invention, the catalytic system further includes: a coupling agent; In some specific embodiments of the present invention, the coupling agent is selected from one or more of γ-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0041] In some specific embodiments of the present invention, the mass ratio of the coupling agent to the silanol in the catalytic system is (2~3):200. For example, it can be any value or a range of values ​​from 2.0:200, 2.5:200, 3.0:200.

[0042] Different coupling agents have different effects on the mechanical properties of the catalyzed material, with γ-aminopropyltriethoxysilane showing the best effect.

[0043] In some specific embodiments of the present invention, the catalytic system further includes a filler.

[0044] In some specific embodiments of the present invention, the filler is selected from nano-calcium carbonate.

[0045] In some specific embodiments of the present invention, the mass ratio of the filler to the silanol in the catalytic system is (180~220):200. For example, it can be any value or a range of values ​​among 180:200, 200:200, and 220:200.

[0046] In some specific embodiments of the present invention, the nano-calcium carbonate has a particle size of 50-80 nm and a specific surface area of ​​25-35 m². 2 ·g -1 .

[0047] In some specific embodiments of the present invention, the catalytic system further includes a lubricant.

[0048] In some specific embodiments of the present invention, the lubricant is selected from dimethyl silicone oil.

[0049] Preferably, the viscosity of the dimethyl silicone oil is 400~600 mPa·s.

[0050] In a specific embodiment of the present invention, a two-component dealcoholized silicone adhesive is also provided, comprising: the catalyst system described above.

[0051] In some specific embodiments of the present invention, the surface drying time of the two-component de-alcoholized silicone adhesive is less than or equal to 5 minutes, preferably 3 to 5 minutes.

[0052] In some specific embodiments of the present invention, the base material of the two-component de-alcoholized silicone adhesive includes silanol, optional fillers, and lubricants.

[0053] In some specific embodiments of the present invention, the two-component de-alcoholized silicone adhesive includes component A and component B; Component A includes silanol, optional filler, lubricant, siloxane crosslinking agent, and optional coupling agent; Component B includes silanol, optional filler, lubricant, tert-butylimino-tris(pyrrolidinyl)phosphine, and metal-based catalyst.

[0054] In a specific embodiment of the present invention, a method for preparing the two-component de-alcoholized silicone adhesive as described above is also provided, comprising: the two-component de-alcoholized silicone adhesive comprising component A and component B; The tert-butylimino-tris(pyrrolidinyl)phosphine and the metal-based catalyst are mixed in component B.

[0055] In some specific embodiments of the present invention, the preparation method includes: Silicon alcohol and lubricant were mixed and stirred under vacuum to remove air bubbles. Filler was added and stirred evenly. Then, under vacuum at 120°C, degassing was performed to obtain base material A. Base material A, siloxane crosslinking agent, and coupling agent were added to a high-speed centrifugal mixer and mixed to obtain component A.

[0056] Silicon alcohol and lubricant were mixed and stirred under vacuum to remove air bubbles. A filler was added and stirred evenly. The mixture was then degassed under vacuum at 120°C to obtain base material B. Base material B, metal-based catalyst, and tert-butylimino-tris(pyrrolidinyl)phosphine were added to a high-speed centrifugal mixer and mixed to obtain component B.

[0057] Mix components A and B thoroughly.

[0058] Generally, component A and component B are mixed in a volume ratio of 1:1.

[0059] The catalytic system and the two-component dealcoholized silicone adhesive of the present invention will be described in detail below with reference to some specific embodiments of the present invention.

[0060] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels. The structures of some raw materials are as follows: Nano-calcium carbonate: Particle size: 60 nm, specific surface area: 30.0 ± 1.0 m² 2 ·g -1 .

[0061] Example 1 This embodiment provides a two-component dealcoholized silicone adhesive, comprising component A and component B in a 1:1 mass ratio. Wherein: The composition of component A, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 10 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; Siloxane crosslinking agent: 25 parts methyltrimethoxysilane; Coupling agent: 2.5 parts of γ-aminopropyltriethoxysilane (KH550).

[0062] The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts of 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate; 1.2 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0063] This embodiment also provides a method for preparing a two-component dealcoholized silicone adhesive, the steps of which are as follows: (1) α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s was mixed with α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80000 mPa·s. Then, dimethyl silicone oil with a viscosity of 500 mPa·s was added. Under the conditions of vacuum degree of -0.05 MPa, temperature of 45℃, and reaction vessel shaft speed of 300 rpm, the mixture was stirred for 15 min to remove obvious bubbles. Subsequently, nano-calcium carbonate was added in two equal portions, with a stirring speed of 180 rpm. After stirring evenly, the mixture was degassed for 120 min at 120℃ and -0.05 MPa to obtain base material A. Base material A, siloxane crosslinking agent, and coupling agent were added to a high-speed centrifugal mixer and mixed to obtain component A.

[0064] (2) α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s was mixed with α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80000 mPa·s. Then, dimethyl silicone oil with a viscosity of 500 mPa·s was added, and the mixture was stirred for 15 min under the conditions of vacuum degree of -0.05 MPa, temperature of 45℃, and reaction vessel shaft speed of 300 rpm to remove large bubbles. Subsequently, nano-calcium carbonate was added in two equal portions, with a stirring speed of 180 rpm. After stirring evenly, the mixture was degassed for 120 min under the conditions of 120℃ and -0.05 MPa to obtain base material B. Base material B, dibutyltin dilaurate, organotitanium catalyst, and tert-butylimino-tris(pyrrolidinyl)phosphine were added to a high-speed centrifugal mixer and mixed to obtain component B.

[0065] (3) Mix the obtained components A and B evenly.

[0066] Example 2 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component A, as follows: The composition of component A, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 10 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; Siloxane crosslinking agent: 25 parts methyltriethoxysilane; Coupling agent: 2.5 parts of γ-aminopropyltriethoxysilane (KH550).

[0067] Example 3 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component A, as follows: The composition of component A, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 10 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; Siloxane crosslinking agent: 25 parts tetra-n-butylsilane; Coupling agent: 2.5 parts of γ-aminopropyltriethoxysilane (KH550).

[0068] Example 4 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component A, as follows: The composition of component A, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 10 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; Siloxane crosslinking agent: 25 parts methyltrimethoxysilane; Coupling agent: 2.5 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane.

[0069] Example 5 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component A, as follows: The composition of component A, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 10 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; Siloxane crosslinking agent: 25 parts methyltrimethoxysilane; Coupling agent: 2.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0070] Example 6 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts tetrabutyl titanate; 1.2 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0071] Example 7 This embodiment provides a two-component dealcoholized silicone adhesive, which differs from Example 1 only in the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts tetraisopropyl titanate; 1.2 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0072] Example 8 The only difference between it and Example 1 is the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts of 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate; 0.4 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0073] Example 9 The only difference between it and Example 1 is the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts of 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate; 0.8 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0074] Example 10 The only difference between it and Example 1 is the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts of 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate; 1.6 parts tert-butylimino-tris(pyrrolidinyl)phosphine.

[0075] Comparative Example 1 The only difference between it and Example 1 is the composition and amount of component B, as follows: The composition of component B, by mass parts, is as follows: 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 10000 mPa·s; 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 80,000 mPa·s; 30 parts of dimethyl silicone oil with a viscosity of 500 mPa·s; 101 parts of nano-calcium carbonate; 4 parts dibutyltin dilaurate; Organotitanium catalyst: 8 parts of 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate.

[0076] Test Example 1 4-hour curing depth: Silicone rubber was poured into a PTFE test plate with a groove of 1cm×1cm×1cm. The test plate was then placed in an air-conditioned room at 21±1℃ and 55±5% relative humidity for four hours. Samples were then taken and the difference in curing depth between the samples was compared.

[0077] Test Example 2 The adhesives prepared in Examples 1-7 above were tested for surface drying time, shear strength, and tensile strength according to GB / T 13477-2002, GB / T 528-2009, and GB / T 7124-2008. The results are shown in Table 1. Table 1

[0078] Comparing Examples 1-3, it can be seen that Example 1 not only dries faster but also has a higher curing depth and stronger mechanical properties than Examples 2 and 3. Therefore, methyltrimethoxysilane is a better choice when selecting a siloxane crosslinking agent.

[0079] Comparing Examples 1, 4, and 5, it can be seen that since the combination of siloxane crosslinking agent and catalyst remains unchanged, the coupling agent mainly affects the adhesion, resulting in a significant decrease in shear strength and frequent interfacial fracture.

[0080] Comparing Examples 1, 6, and 7, the experiment found that the change in titanium catalyst caused the viscosity of component B in Examples 6 and 7 to increase dramatically and visibly. This resulted in an excessively significant viscosity difference between components A and B, making it difficult to extrude and mix evenly. Consequently, the surface drying time became longer, the curing depth after 4 hours became shallower, and the mechanical properties all decreased.

[0081] Comparing Example 1 with Comparative Examples 1 and Examples 8-10. Example 1 had a faster surface drying time and a deeper curing depth at 4 hours compared to Comparative Examples 1 and Examples 8-9, but there was no significant difference in the mechanical properties of the final product. Example 10 used more tert-butylimino-tris(pyrrolidinyl)phosphine than Example 1, which accelerated the local reaction rate of the mixed compound, but resulted in a lower degree of crosslinking than Example 1, and ultimately, the mechanical properties of Example 10 were worse.

[0082] As can be seen from the table above, when methyltrimethoxysilane of the present invention is used as a siloxane crosslinking agent and γ-aminopropyltriethoxysilane is used as a coupling agent, and when combined with dibutyltin dilaurate catalyst, 1,4-butadioxytitanium bis(ethyl acetoacetate) chelate catalyst and tert-butylimino-tris(pyrrolidinyl)phosphine catalyst, not only is the surface drying time short, but the mechanical properties are also the best.

[0083] Finally, it should be noted that the above embodiments are only for illustrating the present invention and not for limiting the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. A catalytic system, characterized in that, This includes a condensation reaction between silanol and a siloxane crosslinking agent, and a tert-butylimino-tris(pyrrolidinyl)phosphine that enhances the rate of the condensation reaction.

2. The catalytic system according to claim 1, characterized in that, The silanol is selected from α,ω-dihydroxypolydimethylsiloxane, and the siloxane crosslinking agent is selected from one or more combinations of methyltrimethoxysilane, methyltriethoxysilane, and tetra-n-butylsilane.

3. The catalytic system according to claim 1 or 2, characterized in that, The catalytic system also includes a metal-based catalyst; Preferably, the metal-based catalyst includes an organotitanium catalyst and / or an organotin catalyst.

4. The catalytic system according to any one of claims 1 to 3, characterized in that, The mass ratio of the tert-butylimino-tris(pyrrolidinyl)phosphine to the metal-based catalyst is 1:(7~15).

5. The catalytic system according to any one of claims 1 to 4, characterized in that, The catalytic system further includes: a coupling agent; Preferably, the coupling agent is selected from one or a combination of two or more of γ-aminopropyltriethoxysilane (KH550), γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

6. The catalytic system according to any one of claims 1 to 5, characterized in that, The catalytic system further includes a filler; preferably, the filler is selected from nano-calcium carbonate.

7. The catalytic system according to any one of claims 1 to 6, characterized in that, The catalytic system further includes a lubricant; the lubricant is selected from dimethyl silicone oil.

8. A two-component dealcoholized silicone adhesive, characterized in that, include: The catalyst system according to any one of claims 1 to 7.

9. The two-component dealcoholized silicone adhesive according to claim 8, characterized in that, The surface drying time of the two-component de-alcoholized silicone adhesive is less than or equal to 5 minutes, preferably 3 to 5 minutes.

10. The two-component dealcoholized silicone adhesive according to claim 8 or 9, characterized in that, The base material of the two-component de-alcoholized silicone adhesive includes silanol, optional fillers, and lubricants; Preferably, the two-component dealcoholized silicone adhesive comprises component A and component B; Component A includes silanol, optional filler, lubricant, siloxane crosslinking agent, and optional coupling agent; Component B includes silanol, optional filler, lubricant, tert-butylimino-tris(pyrrolidinyl)phosphine, and metal-based catalyst.

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