Tackifier, preparation method thereof and organic silicon pouring sealant prepared from tackifier

Abstract

The invention provides a tackifier. The structure of the tackifier is shown as a formula (I). The invention also provides a composition for the organic silicon pouring sealant and the organic silicon pouring sealant. Organosilicon pouring sealant prepared from the tackifier has the advantages of high-temperature rapid curing, excellent adhesion, good flame retardance and good thermal stability, and especially has good adhesiveness to epoxy resin insulating paint and phenyl silicone resin insulating paint under the condition of no primer, # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of silicone materials, and particularly to a tackifier and a preparation method thereof, a silicone potting adhesive prepared therefrom, and a preparation method thereof. Background Art

[0002] With the rapid development of global power technology, the motor manufacturing industry has also shown great vitality with the development of power, and its production and sales scale and economic benefits have been greatly improved. At the same time, its application scope has also expanded rapidly, developing from traditional industrial fields to new fields such as aviation, navigation, military, high-speed rail, and new energy vehicles. In the past decade or so, with the high attention of the world to environmental protection and sustainable development, the market demand for high-speed rail and new energy electric vehicles has been continuously rising. As one of the core components of high-speed rail and electric vehicles, the performance and reliability of the motor also play a crucial role in the performance and lifespan of high-speed rail and vehicles.

[0003] The adhesive potting adhesive for the motor stator is an important manufacturing material for motors in high-speed rail and new energy electric vehicles. The adhesive potting adhesive plays an important role in reducing noise, improving motor efficiency, and extending the lifespan of the motor. The stator adhesive potting adhesive is a material that tightly bonds the stator core (carbon steel sheet) and the stator coil together, mainly used for fixing the coil, isolating vibration, conducting heat, etc. High-quality stator adhesive potting adhesive not only improves the insulation performance of the motor, but also enhances the heat dissipation effect of the motor, reduces noise and vibration, and improves the comfort of the passengers.

[0004] At present, an insulating paint of epoxy resin or phenyl silicone resin will be cured on the surfaces of the stator core (carbon steel sheet) and the stator coil inside the motor. After the insulating paint is cured, a dense and smooth insulating layer will be formed on the surfaces of the core and the coil. Most potting adhesives cannot bond firmly well, so the method of applying a primer is adopted to improve the bonding strength, which complicates the process; and most potting adhesives have high volatiles, which affect the performance of the motor and the surrounding environment; in addition, the long-term heat resistance of the potting adhesive is insufficient, and problems such as cracking, powdering, and strength reduction will occur, thereby affecting the performance of the motor. These are all problems that need to be optimized urgently, and the above problems have a certain negative impact on the development of high-speed rail and new energy vehicles. Summary of the Invention

[0005] The purpose of the present invention is to increase its bonding strength and bonding stability through specific groups of the tackifier, and make it have high heat resistance. The structure of the tackifier is also good in uniformity and high in use stability in the product. Using this tackifier to prepare a silicone potting adhesive, it has high-temperature rapid curing, excellent adhesiveness, good flame retardancy, and good thermal stability. Especially under the condition of no primer, it has good adhesion to epoxy resin insulating paint and phenyl silicone resin insulating paint.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In the first aspect of the present invention, a tackifier is provided, and its structure is shown in formula (I):

[0008]

[0009] wherein, m = 3 - 5, n = 2 - 5.

[0010] Advantages of the above tackifier structure:

[0011] (1) A large number of alkoxy groups are contained in the structure, which can react with the hydroxyl groups on the substrate surface to enhance the bonding strength;

[0012] (2) A small number of vinyl groups are contained in the structure, and the double bonds of the vinyl groups can be opened to participate in the reaction, so as to be connected to the main structure together, enhancing the bonding stability;

[0013] (3) The -NCOO- five-membered ring in the structure can effectively improve the adhesion to various substrates, and has high heat resistance, which can further improve the thermal stability of the product;

[0014] (4) The above structure is overall symmetric, and its weight-average molecular weight is larger compared with that of conventional tackifiers, making its uniformity in the product better and its use stability higher.

[0015] In the second aspect of the present invention, a preparation method of a tackifier is provided, including the following steps:

[0016] Step 1:

[0017]

[0018] Step 2:

[0019]

[0020] Step 3:

[0021]

[0022] Step 4:

[0023]

[0024] wherein, m = 3 - 5, n = 2 - 5, and Ar represents a phenyl group;

[0025] The reaction in Step 1 is carried out under the catalysis of an organotitanium catalyst;

[0026] The reaction in Step 3 is carried out under the catalysis of lithium bromide and trialkylphosphine oxide;

[0027] The reaction in Step 4 is carried out under the catalysis of Kast platinum.

[0028] In some preferred embodiments, the preparation method of the tackifier comprises the following steps:

[0029] Step 1: Under an inert gas atmosphere, under the catalysis of an organotitanium catalyst, the substance shown in formula (II) and the substance shown in formula (III) react at a molar ratio of 1:2 to 2.5 at 40 to 50 °C for 24 to 30 h to obtain the substance shown in formula (IV);

[0030] Step 2: Under an inert gas atmosphere, add the substance shown in formula (IV) prepared in Step 1 and Ar2NCOCl and react at a molar ratio of 1:2 to 2.5 at 60 to 70 °C for 8 to 12 h to obtain the substance shown in formula (V);

[0031] Step 3: Under an inert gas atmosphere, under the catalysis of lithium bromide and trialkylphosphine oxide, the substance shown in formula (V) prepared in Step 2 and the substance shown in formula (VI) react at a molar ratio of 1:2.2 to 2.5 at 80 to 90 °C for 4 to 6 h to obtain the substance shown in formula (VII);

[0032] Step 4: Under an inert gas atmosphere, under the catalysis of Kast platinum, the substance shown in formula (VII) prepared in Step 3 and the substance shown in formula (VIII) react at a molar ratio of 1:0.3 to 0.5 at 60 to 70 °C for 2 to 3 h to obtain the tackifier.

[0033] The third aspect of the present invention provides an application of the above-mentioned tackifier in the preparation of potting adhesives, preferably silicone potting adhesives.

[0034] The potting adhesive prepared by using the above-mentioned tackifier can achieve high-temperature rapid curing, has excellent adhesion, good flame retardancy and good thermal stability. Especially under the condition of no primer, it has good adhesion to epoxy resin insulating paint and phenyl silicone resin insulating paint.

[0035] The fourth aspect of the present invention provides a composition for silicone potting adhesive, comprising component A and component B;

[0036] Component A comprises the following components by weight: 10 - 20 parts of 900 - 1100 mPa·s vinyl silicone oil; 20 - 40 parts of 450 - 550 mPa·s vinyl silicone oil; 1 - 5 parts of methylphenylvinyl silicone oil; 10 - 30 parts of filler-1; 15 - 40 parts of filler-2; 3 - 6 parts of color paste; 0.1 - 1 part of catalyst;

[0037] Component B includes the following components by weight parts: 30 - 50 parts of vinyl silicone oil with a viscosity of 450 - 550 mPa·s; 10 - 30 parts of filler - 1; 5 - 15 parts of filler - 2; 5 - 10 parts of filler - 3; 1 - 3 parts of cross - linker - 1; 2 - 6 parts of cross - linker - 2; 0.001 - 0.01 part of inhibitor; 0.1 - 1 part of coupling agent; 0.5 - 2 parts of the tackifier described in Claim 1; 0.5 - 1 part of heat - resistant stabilizer;

[0038] Among them, the mass ratio of Component A to Component B is 1:0.8 - 2.

[0039] In the present invention, Component A and Component B are prepared separately and then mixed to obtain a two - component potting adhesive. The method of separate preparation can make the dispersion degree of each component in Component A and Component B better. The components with less dosage can be more evenly distributed, and the obtained silicone potting adhesive has better uniformity and higher use stability. By controlling the mass ratio of Component A to Component B to be 1:0.8 - 2, the obtained silicone potting adhesive can achieve high - temperature rapid curing and has more excellent adhesiveness.

[0040] In some preferred embodiments, the vinyl content of the 900 - 1100 mPa·s vinyl silicone oil is 0.27 - 0.32 wt%, the volatile content ≤ 0.05%, and the D3 - D10 siloxane content ≤ 100 mg / kg; and / or the vinyl content of the 450 - 550 mPa·s vinyl silicone is 0.40 - 0.45 wt%, the volatile content ≤ 0.05%, and the D3 - D10 siloxane content ≤ 100 mg / kg; and / or the molecular formula of the methylphenylvinyl silicone oil is as follows: (ViMePhSiO 0.5 )(Me2SiO)x(ViMePhSiO 0.5 ) Formula (IX), where the vinyl content is 0.03 - 0.08 wt%, and the weight - average molecular weight is 2000 - 5000;

[0041] Preferably, the 900 - 1100 mPa·s vinyl silicone oil is Wanhua Chemical's electronic - grade vinyl silicone oil SF - 61 - 1000E, and the 450 - 550 mPa·s vinyl silicone oil is Wanhua Chemical's electronic - grade vinyl silicone oil SF - 61 - 500E.

[0042] The present invention selects vinyl silicone oils with low - volatile organic compounds (low volatile content) and low cyclic body content (low D3 - D10 siloxane content), preferably electronic - grade silicone oils, so that the obtained silicone potting adhesive reaches a very low VOC level, reducing the impact of the silicone potting adhesive on each device inside the motor and the environment.

[0043] The present invention selects methylphenylvinyl silicone oil with a molecular formula as shown in formula (IX). Using the above-mentioned methylphenylvinyl silicone oil improves the wettability between the potting adhesive and the surface of phenyl silicone resin, and the phenyl group in the structure has rotatability, which helps to improve the heat resistance of the potting adhesive after curing and further ensures the thermal stability of the potting adhesive.

[0044] In some preferred embodiments, the filler-1 is spherical silica powder with a D50 of 2-3 microns; the filler-2 is spherical alumina powder with a D50 of 2-3 microns; the filler-3 is spherical aluminum hydroxide powder with a D50 of 5-6 microns.

[0045] The present invention selects filler-1, filler-2 and filler-3. The above three powders cooperate with each other, which not only ensures that the potting adhesive can meet the medium heat conduction requirements, but also has good flame retardancy and ensures that the system has good anti-settling property.

[0046] The crosslinking agent-1 is hydrogen-terminated silicone oil with a viscosity of 5-20 mPa·s and a hydrogen content of 0.15-0.20 wt%; the crosslinking agent-2 is methyl-terminated side-hydrogenated silicone oil with a viscosity of 50-150 mPa·s and a hydrogen content of 0.6-1.0 wt%.

[0047] The present invention selects hydrogen-terminated silicone oil and methyl-terminated side-hydrogenated silicone oil. The side-hydrogenated silicone oil and the hydrogen-terminated silicone oil cooperate with each other, which not only ensures the crosslinking density and strength, but also makes the prepared potting adhesive have good toughness due to a certain chain segment length.

[0048] In some preferred embodiments, the color paste is iron red color paste; and / or the catalyst is a platinum-based catalyst, preferably a platinum-vinylsiloxane complex, with a platinum content of 3000-6000 ppm; and / or the inhibitor is an alkynol compound, preferably one or more of 1-ethynyl-1-cyclohexanol, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, more preferably 1-ethynyl-1-cyclohexanol; and / or the coupling agent is one or more of KH-550, KH-560, KH-570, A-186, KH-792; and / or the heat-resistant stabilizer is cerium dioxide.

[0049] The fifth aspect of the present invention provides an organosilicon potting adhesive, which is prepared by curing the above composition;

[0050] Preferably, the preparation process of the organosilicon potting adhesive includes: first, uniformly mix the components of the component A and the component B respectively, then mix the obtained component A mixture and component B mixture and cure at 100-120 °C for 30-60 min to obtain the organosilicon potting adhesive;

[0051] More preferably, the preparation process of the component A mixture includes: adding 450-550 mPa·s vinyl silicone oil, methylphenylvinyl silicone oil, and color paste into a mixing container; then adding filler-1 and filler-2; then adding 900-1100 mPa·s vinyl silicone oil; finally adding a catalyst;

[0052] The preparation process of the component B mixture includes: adding 450-550 mPa·s vinyl silicone oil, crosslinking agent-1, crosslinking agent-2, filler-1, filler-2, and filler-3 into a mixing container; then adding a tackifier, coupling agent, heat-resistant stabilizer, and inhibitor.

[0053] Most preferably, the preparation method of component A: 1) Add 450-550 mPa·s vinyl silicone oil, methylphenylvinyl silicone oil, and color paste into a mixing container, set the rotation speed of the high-speed mixer: revolution 15-25 rpm, high-speed dispersion 400-600 rpm, mix for 15-30 min; 2) Add filler-1 and filler-2, set the rotation speed of the high-speed mixer: revolution 35-45 rpm, high-speed dispersion 1200-1800 rpm, mix for 20-40 min, stop the machine and scrape the wall; 3) Add 900-1100 mPa·s vinyl silicone oil, set the rotation speed of the high-speed mixer: revolution 35-45 rpm, high-speed dispersion 800-1200 rpm, mix for 20-40 min, stop the machine and scrape the wall; set the rotation speed of the high-speed mixer: revolution 35-45 rpm, high-speed dispersion 800-1200 rpm, vacuum mix for 20-40 min, stop the machine, relieve pressure and scrape the wall; 4) Add a catalyst, set the rotation speed of the high-speed mixer: revolution 25-35 rpm, high-speed dispersion 600-800 rpm, vacuum mix for 20-40 min, stop the machine, relieve pressure and scrape the wall, then component A is obtained;

[0054] The preparation method of component B: 1) Add 450-550 mPa·s vinyl silicone oil, crosslinking agent-1, crosslinking agent-2, filler-1, filler-2, and filler-3 into a mixing container, set the rotation speed of the high-speed mixer: revolution 35-45 rpm, high-speed dispersion 1200-1800 rpm, after all the powder is mixed into the silicone oil, continue to mix for 20-40 min, stop the machine and scrape the wall; 2) Set the rotation speed of the high-speed mixer: revolution 35-45 rpm, high-speed dispersion 800-1200 rpm, vacuum mix for 20-40 min, stop the machine, relieve pressure and scrape the wall; 3) Under a nitrogen atmosphere, add a tackifier, coupling agent, heat-resistant stabilizer, and inhibitor, set the rotation speed of the high-speed mixer: revolution 25-35 rpm, high-speed dispersion 600-800 rpm, mix for 15-30 min, stop the machine and scrape the wall; 4) Set the rotation speed of the high-speed mixer: revolution 25-35 rpm, high-speed dispersion 600-800 rpm, vacuum mix for 8-12 min, stop the machine, relieve pressure and scrape the wall, then component B is obtained;

[0055] Preparation method of silicone potting adhesive: Mix the obtained component A and component B and cure them. The mixing conditions are: rotation speed 400 - 600 rpm, vacuum degree -0.98 Mpa, mixing for 20 - 40 min, and the curing conditions are: temperature 100 - 120 °C, time 30 - 60 min, to obtain the silicone potting adhesive.

[0056] In the present invention, component A and component B are respectively prepared and then mixed to obtain a two-component potting adhesive. By adopting the method of separate preparation, the dispersion degree of each component in component A and component B can be better, and the components with less dosage can be more evenly distributed. The obtained silicone potting adhesive has better uniformity and higher use stability. First, add the silicone oil with the largest required amount, and then add the powder materials, such as fillers. Since the viscosity of the system is relatively large in the early stage, the dispersion of the powder materials is better. Then add another silicone oil with a relatively large viscosity, disperse and stir under pressure, and finally add the components with less dosage to avoid the adsorption and aggregation of the components with less dosage. The above feeding sequence shortens the stirring time, reduces the energy consumption, and can effectively avoid the loss of the components with less dosage.

[0057] The sixth aspect of the present invention provides an application of the silicone potting adhesive in the thermal conduction bonding of motor stators.

[0058] The technical solution provided by the present invention has the following beneficial effects:

[0059] By providing a tackifier with a specific structure, the bonding strength and bonding stability are enhanced, the adhesion to various substrates is effectively improved, and at the same time, it has high heat resistance, which can further improve the thermal stability of the product; the above structure is overall symmetrical and has a large weight average molecular weight, making its uniformity in the product better and its use stability higher.

[0060] The silicone potting adhesive prepared by using the above tackifier can achieve high-temperature rapid curing, has excellent adhesiveness, good flame retardancy and good thermal stability. Especially under the condition of no primer, it has good adhesion to epoxy resin insulating paint and phenyl silicone resin insulating paint.

[0061] When the above silicone potting adhesive is used for the thermal conduction bonding of motor stators, due to its good adhesion to epoxy resin insulating paint and phenyl silicone resin insulating paint, no primer is required, the process is simple, and the volatile content of the above organic potting adhesive is low. At the same time, it can effectively reduce the impact of the potting adhesive on the performance of the motor and the surrounding environment. Specific embodiments

[0062] The present invention will be further described below through specific embodiments. The embodiments described in the present invention are only for the illustration of the present invention, and do not mean that the scope of the present invention is limited thereto.

[0063] The raw materials or reagents used in the examples and comparative examples of the present invention are as follows, and other raw materials or reagents are commercially available unless otherwise specified.

[0064] The substance represented by formula (II): MY 1203V from Anhui Mingyi Silicon Industry Co., Ltd.;

[0065] The substance represented by formula (III): LT-550 produced by Hubei New Blue Sky New Materials Co., Ltd.;

[0066] Ar2NCOCl: MacLean's N,N-diphenylchloroformamide;

[0067] The substance represented by formula (VI): KH-560 produced by Hangzhou Jessica Chemical Co., Ltd.;

[0068] The substance represented by formula (VIII): RH-DH01 produced by Zhejiang Runhe Organic Silicone New Materials Co., Ltd.;

[0069] Lithium bromide: Merck & Co., Ltd.;

[0070] Trialkylphosphine oxide: Aladdin's trihexylphosphine oxide / trioctylphosphine oxide;

[0071] Methylphenyl vinyl silicone oil: IOTA252 from Anhui Iyota Silicone Oil Co., Ltd.;

[0072] Platinum catalyst: Japan Shin-Etsu, CAT-PL-56 platinum catalyst;

[0073] Filler-1: SSF-002 from Tianjin Zexi New Materials Co., Ltd.;

[0074] Filler-2: MK-75E from Foshan Huaya Superfine Powder Co., Ltd.

[0075] Filler-3: KA-5D from Foshan Huaya Superfine Powder Co., Ltd.

[0076] Crosslinker-1: RH-H518 from Zhejiang Runhe Silicone New Materials Co., Ltd.

[0077] Crosslinker-2: RH-H802 from Zhejiang Runhe Silicone New Materials Co., Ltd.

[0078] Color paste: WH03-BR01 from Shanghai Jingyi.

[0079] Example 1

[0080] Synthesis of tackifier:

[0081] Step 1:

[0082]

[0083] Under a nitrogen atmosphere, 522 g of the substance shown by formula (II) (where m = 4, n = 2) and 442 g of the substance shown by formula (III) were added to a 2 L glass reaction kettle. The reaction kettle was equipped with a condensation reflux device; they were mixed at 500 rpm for 0.5 h; then 0.7 g of Tyzor 9000 catalyst was added and mixed at 500 rpm for 0.5 h; the reaction temperature was raised to 40 °C and reacted for 24 h; by-product ethanol was removed by vacuum distillation (under a vacuum of less than -0.98 MPa), and the substance shown by formula (IV) (where m = 4, n = 2) was obtained (stored sealed under nitrogen).

[0084] Step 2:

[0085]

[0086] Under a nitrogen atmosphere, 846 g of the substance shown by formula (IV) (where m = 4, n = 2) prepared in Step 1 was added to a 2 L glass reaction kettle. The rotation speed was set at 700 rpm, and 462 g of Ar2NCOCl was added dropwise to the substance shown by formula (IV) within 60 min; after the addition, the reaction was carried out at 60 °C for 8 h, and by-product HCl was removed by vacuum distillation (under a vacuum of less than -0.98 MPa); the temperature was raised and vacuum distillation was carried out (under a vacuum of less than -0.98 MPa), and the fraction at 220 - 225 °C was collected. This distillate was the substance shown by formula (V) (where m = 4, n = 2) (stored sealed under nitrogen); the remaining undistilled substance was by-product diphenylamine.

[0087] Step 3:

[0088]

[0089] Under a nitrogen atmosphere, 898 g of the substance shown by formula (V) (where m = 4, n = 2) prepared in Step 2 and 520 g of the substance shown by formula (VI) were added to a 2 L glass reaction kettle. The rotation speed was set at 600 rpm and mixed for 20 min; then 0.7 g of lithium bromide and 0.7 g of trihydrocarbylphosphine oxide were added, and the reaction was carried out at 80 °C for 4 h; the temperature was raised and vacuum distillation was carried out (under a vacuum of less than -0.98 MPa), and the fraction at 200 - 205 °C was collected. This distillate was the unreacted substance shown by formula (VI); the temperature was continuously raised and vacuum distillation was carried out (under a vacuum of less than -0.98 MPa), and the fraction at 240 - 245 °C was collected. This distillate was the substance shown by formula (VII) (where m = 4, n = 2) (stored sealed under nitrogen).

[0090] Step 4:

[0091]

[0092] Under a nitrogen atmosphere, 1370 g of the substance shown in formula (VII) prepared in step 3 was added to a 2 L glass reaction kettle, and then 1.513 g of Cast platinum catalyst (platinum content 5000 ppm) was added. The rotation speed was set at 800 rpm and mixed for 20 min; 143 g of the substance shown in formula (VIII) was dropped into the substance shown in formula (VII) within 60 min; after dropping, the reaction was carried out at 60 °C for 2 h; the temperature was raised and vacuum distillation was carried out (vacuum degree below -0.98 MPa), and the fraction at 240 - 245 °C was collected. This distillate was the unreacted substance shown in formula (VII) and the substance shown in formula (VIII); the temperature was continuously raised and vacuum distillation was carried out (vacuum degree below -0.98 MPa), and the fraction at 260 - 265 °C was collected. This distillate was the tackifier of formula (I) (where m = 4, n = 2) (stored sealed under nitrogen), and the total yield of the tackifier was 85%.

[0093] Nuclear magnetic resonance spectroscopy 13 C NMR(CDCl3, 150.0 MHz): δ 4.3 - 6.8 (m, CHCH2, OCH2CH3), 16.7 (s, CHCH2), 18.4, 41.9 [s, NC(O)OC], 50.2 (s, OCH3), 54 [m, NC(O)OC], 58.1 (s, OCH2), 72 - 83 [m, NC(O)OC].

[0094] Example 2

[0095] Preparation method of component A: 1) Add 2500 g of Wanhua Chemical electronic-grade vinyl silicone oil SF-61-500E, 300 g of methylphenylvinyl silicone oil (vinyl content 0.05 wt%, weight-average molecular weight 3000), and 400 g of WH03-BR01 to the mixing kettle. Set the rotation speed of the high-speed mixer: revolution 20 rpm, high-speed dispersion 500 rpm, and mix for 20 min; 2) Add 1500 g of SSF-002 and 3000 g of MK-75E. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm, and mix for 30 min, then stop and scrape the wall; 3) Add 1500 g of Wanhua Chemical electronic-grade vinyl silicone oil SF-61-1000E. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, and mix for 30 min, then stop and scrape the wall; Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop, relieve pressure and scrape the wall; 4) Add 50 g of platinum-based catalyst. Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop, relieve pressure and scrape the wall to obtain component A;

[0096] Preparation method of Component B: 1) Add 4000 g of Wanhua Chemical's electronic-grade vinyl silicone oil SF-61-500E, 200 g of RH-H518 (hydrogen content 0.18 wt%), 400 g of RH-H802 (hydrogen content 0.8 wt%), 1500 g of SSF-002, 1000 g of MK-75E, and 700 g of KA-5D into a mixing container. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm. After all the powder is mixed into the silicone oil, continue mixing for 30 min, then stop the machine and scrape the wall; 2) Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop the machine, relieve the pressure, and scrape the wall; 3) Under a nitrogen atmosphere, add 150 g of the tackifier of formula (I) (where m = 4, n = 2), 50 g of KH560, 80 g of cerium dioxide, 0.5 g of 1-ethynyl-1-cyclohexanol. Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, mix for 20 min, then stop the machine and scrape the wall; 4) Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, mix under vacuum (vacuum degree below -0.98 MPa) for 10 min, then stop the machine, relieve the pressure, and scrape the wall to obtain Component B;

[0097] Preparation method of silicone potting adhesive: Mix the obtained Component A and Component B in a mass ratio of 1:1 and cure them. The mixing conditions are: rotation speed 500 rpm, vacuum degree -0.98 Mpa, mixing for 30 min. The curing conditions are: temperature 100 °C, time 30 min to obtain the silicone potting adhesive.

[0098] Example 3

[0099] Preparation method of Component A: 1) Add 4000 g of Wanhua Chemical's electronic-grade vinyl silicone oil SF-61-500E, 200 g of methylphenylvinyl silicone oil (vinyl content 0.05 wt%, weight-average molecular weight 3000), and 500 g of WH03-BR01 into the mixing kettle. Set the rotation speed of the high-speed mixer: revolution 20 rpm, high-speed dispersion 500 rpm, and mix for 20 min; 2) Add 2000 g of SSF-002 and 3500 g of MK-75E. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm, and mix for 30 min, then stop the machine and scrape the wall; 3) Add 1000 g of Wanhua Chemical's electronic-grade vinyl silicone oil SF-61-1000E. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, and mix for 30 min, then stop the machine and scrape the wall; Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop the machine, release the pressure, and scrape the wall; 4) Add 70 g of platinum-based catalyst. Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop the machine, release the pressure, and scrape the wall, thus obtaining Component A;

[0100] Preparation method of Component B: 1) Add 3500 g of Wanhua Chemical's electronic-grade vinyl silicone oil SF-61-500E, 150 g of RH-H518 (hydrogen content 0.18 wt%), 300 g of RH-H802 (hydrogen content 1.0 wt%), 2000 g of SSF-002, 800 g of MK-75E, and 600 g of KA-5D into the mixing container. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm. After all the powder is mixed into the silicone oil, continue to mix for 30 min, then stop the machine and scrape the wall; 2) Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop the machine, release the pressure, and scrape the wall; 3) Under a nitrogen atmosphere, add 100 g of the tackifier of formula (I) (where m = 4, n = 2), 70 g of KH570, 70 g of cerium dioxide, and 0.7 g of 1-ethynyl-1-cyclohexanol. Set the rotation speed of the high-speed mixer: revolution 30 pm, high-speed dispersion 700 rpm, and mix for 20 min, then stop the machine and scrape the wall; 4) Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, and mix under vacuum (vacuum degree below -0.98 MPa) for 10 min, then stop the machine, release the pressure, and scrape the wall, thus obtaining Component B;

[0101] Preparation method of silicone potting adhesive: Mix the obtained Component A and Component B in a mass ratio of 1:1.2 and cure them. The mixing conditions are: rotation speed 500 rpm, vacuum degree -0.98 Mpa, mixing for 30 min, and the curing conditions are: temperature 100 °C, time 30 min, to obtain the silicone potting adhesive.

[0102] Example 4

[0103] Preparation method of Component A: 1) Add 2500 g of Wanhua Chemical electronic-grade vinyl silicone oil SF-61-500E, 400 g of methylphenylvinyl silicone oil (vinyl content 0.05 wt%, weight-average molecular weight 5000), and 350 g of WH03-BR01 into a mixing kettle, and set the rotation speed of the high-speed mixer: revolution 20 rpm, high-speed dispersion 500 rpm, mix for 20 min; 2) Add 3000 g of SSF-002 and 1500 g of MK-75E, and set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm, mix for 30 min, and stop the machine to scrape the wall; 3) Add 2000 g of Wanhua Chemical electronic-grade vinyl silicone oil SF-61-1000E, and set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, mix for 30 min, and stop the machine to scrape the wall; set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, vacuum (vacuum degree below -0.98 MPa) mix for 30 min, and stop the machine to release pressure and scrape the wall; 4) Add 30 g of platinum-based catalyst, and set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, vacuum (vacuum degree below -0.98 MPa) mix for 30 min, and stop the machine to release pressure and scrape the wall, to obtain Component A;

[0104] Preparation method of Component B: 1) Add 5000 g of Wanhua Chemical's electronic-grade vinyl silicone oil SF-61-500E, 250 g of RH-H518 (hydrogen content 0.2 wt%), 600 g of RH-H802 (hydrogen content 0.7 wt%), 2500 g of SSF-002, 1200 g of MK-75E, and 900 g of KA-5D into a mixing container. Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1500 rpm. After all the powder is mixed into the silicone oil, continue mixing for 30 min, then stop the machine and scrape the wall; 2) Set the rotation speed of the high-speed mixer: revolution 40 rpm, high-speed dispersion 1000 rpm, mix under vacuum (vacuum degree below -0.98 MPa) for 30 min, then stop the machine, release the pressure, and scrape the wall; 3) Under a nitrogen atmosphere, add 200 g of the tackifier of formula (I) (where m = 4, n = 2), 90 g of KH560, 50 g of cerium dioxide, and 0.3 g of 1-ethynyl-1-cyclohexanol. Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, mix for 20 min, then stop the machine and scrape the wall; 4) Set the rotation speed of the high-speed mixer: revolution 30 rpm, high-speed dispersion 700 rpm, mix under vacuum (vacuum degree below -0.98 MPa) for 10 min, then stop the machine, release the pressure, and scrape the wall to obtain Component B;

[0105] Preparation method of silicone potting adhesive: Mix the obtained Component A and Component B in a mass ratio of 1:0.8 and cure them. The mixing conditions are: rotation speed 500 rpm, vacuum degree -0.98 Mpa, mixing for 30 min. The curing conditions are: temperature 100 °C, time 30 min to obtain the silicone potting adhesive.

[0106] Comparative Example 1

[0107] Comparative Example 1 is the same as Example 4, except that 290 g of KH560 is used to replace 200 g of the tackifier of formula (I) and 90 g of KH560.

[0108] Comparative Example 2

[0109] In Comparative Example 2, the adhesive potting adhesive Wacker 607 (Wacker Chemie (China) Co., Ltd.) is used instead of the silicone potting adhesive prepared through Example 4, without a primer. The curing conditions are changed to: temperature 100 °C, time 120 min.

[0110] Comparative Example 3

[0111] In Comparative Example 3, the adhesive potting adhesive Wacker 607 is used instead of the silicone potting adhesive prepared through Example 4, and the primer Wacker G790 (Wacker Chemie (China) Co., Ltd.) is used in combination on the substrate surface. The curing conditions are changed to: temperature 100 °C, time 120 min.

[0112] Comparative Example 4

[0113] In Comparative Example 4, the adhesive potting compound Wacker 607 was used instead of the silicone potting compound prepared in Example 4, and was used in combination with the primer Wacker G790 on the substrate surface. The curing conditions were the same as those in Example 4.

[0114] Test Example

[0115] The mixing ratio of the adhesive potting compound Wacker 607 was mixed at a mass ratio of 9:1 of Component A (catalyst component) to Component B (crosslinking agent component).

[0116] Shear strength: in accordance with ASTM D1002 standard

[0117] (1) Phenyl silicone resin insulating paint - shear strength: Carbon steel with dimensions of 10 mm * 25 mm * 2 mm was selected. First, a layer of phenyl silicone resin insulating paint was applied to the surface of the carbon steel, and then baked at 200 °C for 24 h. The insulating paint was cured into a film. The potting compounds of Examples 2 - 4 and Comparative Examples 1 - 4 were respectively applied (the thickness of the glue layer was 2 mm), and the primer Wacker G790 needed to be additionally applied in Comparative Examples 3 and 4, and heated for curing. After curing, it was cooled to room temperature for testing. Using a universal tensile machine with a tensile rate of 5 mm / min, the shear strength of the sample against the insulating paint was measured, and the result was the average value of 5 tests.

[0118] (2) Epoxy resin insulating paint - shear strength: Carbon steel with dimensions of 10 mm * 25 mm * 2 mm was selected. First, a layer of epoxy resin insulating paint was applied to the surface of the carbon steel, and then baked at 175 °C for 12 h. The insulating paint was cured into a film. The potting compounds of Examples 2 - 4 and Comparative Examples 1 - 4 were respectively applied (the thickness of the glue layer was 2 mm), and the primer Wacker G790 needed to be additionally applied in Comparative Examples 3 and 4, and heated for curing. After curing, it was cooled to room temperature for testing. Using a universal tensile machine with a tensile rate of 5 mm / min, the shear strength of the sample against the insulating paint was measured, and the result was the average value of 5 tests.

[0119] The performance test results of the samples are shown in Table 1:

[0120] Table 1

[0121]

[0122] Note: Explanation of failure state

[0123] Cohesive failure: It refers to the phenomenon that the glue layer itself breaks, separates or peels off.

[0124] Interface failure: After two objects are bonded together by an adhesive, under the action of an external force, the failure occurs between the interface of the object and the adhesive.

[0125] Mixed failure: That is, the mixture of interface failure and cohesive failure.

[0126] It can be clearly seen from the test data in Table 1 that: compared with Comparative Examples 1-4, in Examples 2-4 where the tackifier of formula (I) is used to prepare the potting adhesive, the tackifier significantly improves the bonding strength and bonding stability of the potting adhesive. This potting adhesive shows good adhesion to both phenyl silicone resin insulating paint and epoxy resin insulating paint, and this tackifier also significantly improves the heat resistance stability of the potting adhesive.

[0127] From the data analysis of Example 4 and Comparative Example 1, it can be seen that the tackifier can significantly improve the adhesiveness of the potting adhesive to the two insulating paints and also has a good improvement effect on the heat resistance stability of the potting adhesive; from the data comparison between Examples 2-4 and Comparative Example 2, it can be seen that the potting adhesive of the present invention has obvious advantages in bonding performance without a primer; from the data comparison between Examples 2-4 and Comparative Example 3, it can be seen that in terms of bonding performance, the potting adhesive of the present invention still has strong bonding performance advantages compared with other brands using a primer; from the data comparison between Examples 2-4 and Comparative Examples 2, 3, and 4, it can be seen that even after shortening the curing time by 75%, the bonding strength of the potting adhesive of the present invention still has obvious advantages.

[0128] Obviously, the above examples are only for clear illustration and not for limitation of the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A tackifier, the structure of which is shown in formula (I): Among them, m = 3 - 5, n = 2 - 5.

2. A preparation method of a tackifier, comprising the following steps: Step 1: Step 2: Step 3: Step 4: Among them, m = 3 - 5, n = 2 - 5, Ar represents phenyl; The reaction in Step 1 is carried out under the catalysis of an organotitanium catalyst; The reaction in Step 3 is carried out under the catalysis of lithium bromide and trialkylphosphine oxide; The reaction in Step 4 is carried out under the catalysis of Karstedt's platinum.

3. The preparation method of the tackifier according to claim 2, comprising the following steps: Step 1: Under an inert gas atmosphere, under the catalysis of an organotitanium catalyst, the substance shown in formula (II) and the substance shown in formula (III) react at a molar ratio of 1:2 - 2.5 at 40 - 50 °C for 24 - 30 h to obtain the substance shown in formula (IV); Step 2: Under an inert gas atmosphere, the substance shown in formula (IV) prepared in Step 1 and Ar2NCOCl react at a molar ratio of 1:2 - 2.5 at 60 - 70 °C for 8 - 12 h to obtain the substance shown in formula (V); Step 3: Under an inert gas atmosphere, under the catalysis of lithium bromide and trialkylphosphine oxide, the substance shown in formula (V) prepared in Step 2 and the substance shown in formula (VI) react at a molar ratio of 1:2.2 - 2.5 at 80 - 90 °C for 4 - 6 h to obtain the substance shown in formula (VII); Step 4: Under an inert gas atmosphere, under the catalysis of Karstedt's platinum, the substance shown in formula (VII) prepared in Step 3 and the substance shown in formula (VIII) react at a molar ratio of 1:0.3 - 0.5 at 60 - 70 °C for 2 - 3 h to obtain the said tackifier.

4. The application of the tackifier according to claim 1 in the preparation of potting adhesives, preferably silicone potting adhesives.

5. A composition for silicone potting adhesive, characterized in that, It includes component A and component B; Component A includes the following components by weight: 10 - 20 parts of 900 - 1100 mPa·s vinyl silicone oil; 20 - 40 parts of 450 - 550 mPa·s vinyl silicone oil; 1 - 5 parts of methylphenylvinyl silicone oil; 10 - 30 parts of filler - 1; 15 - 40 parts of filler - 2; 3 - 6 parts of color paste; 0.1 - 1 part of catalyst; Component B includes the following components by weight: 30 - 50 parts of 450 - 550 mPa·s vinyl silicone oil; 10 - 30 parts of filler - 1; 5 - 15 parts of filler - 2; 5 - 10 parts of filler - 3; 1 - 3 parts of cross - linker - 1; 2 - 6 parts of cross - linker - 2; 0.001 - 0.01 part of inhibitor; 0.1 - 1 part of coupling agent; 0.5 - 2 parts of the tackifier according to claim 1; 0.5 - 1 part of heat - resistant stabilizer; Wherein, the mass ratio of the said component A to the said component B is 1:0.8 - 2.

6. The composition according to claim 5, wherein The vinyl content of the 900 - 1100 mPa·s vinyl silicone oil is 0.27 - 0.32 wt%, the volatile matter ≤ 0.05%, and the D3 - D10 siloxane content ≤ 100 mg / kg; and / or The vinyl content of the 450 - 550 mPa·s vinyl silicone is 0.40 - 0.45 wt%, the volatile content ≤ 0.05%, and the D3 - D10 siloxane content ≤ 100 mg / kg; and / or The molecular formula of the methylphenylvinyl silicone oil is as follows: (ViMePhSiO 0.5 )(Me2SiO)x(ViMePhSiO 0.5 ) Formula (IX), wherein the vinyl content is 0.03 to 0.08 wt%, and the weight-average molecular weight is 2,000 to 5,000.

7. The composition according to claim 5, wherein The filler - 1 is spherical silica powder with a D50 of 2 - 3 microns; the filler - 2 is spherical alumina powder with a D50 of 2 - 3 microns; the filler - 3 is spherical aluminum hydroxide powder with a D50 of 5 - 6 microns; and / or The cross - linker - 1 is hydrogen - terminated silicone oil with a viscosity of 5 - 20 mPa·s and a hydrogen content of 0.15 - 0.20 wt%; the cross - linker - 2 is methyl - terminated side - hydrogen - containing silicone oil with a viscosity of 50 - 150 mPa·s and a hydrogen content of 0.6 - 1.0 wt%.

8. The composition according to claim 5, wherein The color paste is iron - red color paste; and / or The catalyst is a platinum - based catalyst, preferably a platinum - vinylsiloxane complex, with a platinum content of 3000 - 6000 ppm; and / or The inhibitor is an alkynol compound, preferably one or more of 1 - ethynyl - 1 - cyclohexanol, 3 - methyl - 1 - butyn - 3 - ol, 3,5 - dimethyl - 1 - hexyn - 3 - ol, and more preferably 1 - ethynyl - 1 - cyclohexanol; and / or The coupling agent is one or more of KH - 550, KH - 560, KH - 570, A - 186, KH - 792; and / or The heat - resistant stabilizer is cerium dioxide.

9. A silicone potting adhesive, which is prepared by curing the composition according to any one of claims 5 - 8; Preferably, the preparation process of the silicone potting adhesive includes: first, uniformly mix the components of the A component and the B component respectively, then mix the obtained A - component mixture and B - component mixture and cure at 100 - 120 °C for 30 - 60 min to obtain the silicone potting adhesive; More preferably, the preparation process of the A - component mixture includes: adding 450 - 550 mPa·s vinyl silicone oil, methylphenylvinyl silicone oil, and color paste into a mixing container; then adding filler - 1 and filler - 2; then adding 900 - 1100 mPa·s vinyl silicone oil; finally adding the catalyst; The preparation process of the B - component mixture includes: adding 450 - 550 mPa·s vinyl silicone oil, cross - linker - 1, cross - linker - 2, filler - 1, filler - 2, and filler - 3 into a mixing container; then adding tackifier, coupling agent, heat - resistant stabilizer, and inhibitor.

10. The application of the silicone potting adhesive according to claim 9 in the thermal conduction bonding of motor stators.

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