Bisphenol-based silicone resin microspheres, their preparation method and applications

Abstract

The present invention discloses a bisphenol-based silicone resin microsphere, a preparation method thereof and an application thereof, relating to the technical field of silicone resins. The bisphenol-based silicone resin microsphere has a core-shell structure, wherein the core is a silicone resin and the shell is a bisphenol-based silicone resin. The bisphenol-based silicone resin microsphere provided by the present invention contains bisphenol groups on its surface, which can improve the compatibility between the silicone resin microsphere and the epoxy resin; the alkyl groups can adjust the flexibility of the molecule, further improve the compatibility between the silicone resin microsphere and the epoxy resin, and thereby improve the anti-settling performance of the silicone resin microsphere in the epoxy resin.

Description

Technical Field:

[0001] The present invention relates to the technical field of silicone resins, and particularly relates to a bisphenol-type silicone resin microsphere, a preparation method thereof, and an application thereof. Background Art:

[0002] Silicone resin microspheres are semi-inorganic and semi-organic micron-sized spherical particles with silicon-oxygen bonds, silicon-carbon bonds, and carbon-hydrogen bonds, and have excellent high and low temperature resistance, weather resistance, wear resistance, hydrophobicity, electrical insulation, special optical properties, chemical inertness, physiological inertness, non-toxic, odorless, and harmless characteristics. They can be widely used in the processing and modification fields of polymer materials such as plastics, rubbers, and coatings to improve the physical and chemical properties of materials such as heat resistance, cold resistance, wear resistance, flame retardancy, and light diffusion. At the same time, they can also be used in ink modification, cosmetics lubrication, biological engineering, chemical separation and other fields.

[0003] Silicone resin microspheres have excellent heat resistance and flexibility, and various properties are very complementary to epoxy resins. Modifying epoxy resins with silicone resin microspheres can not only introduce flexible Si-O bonds into the epoxy resins, reduce the internal stress of the cured product, and improve the toughness of the cured product; the high bond energy of the Si-O bond can also enhance the thermal stability of the system, endow the cured product with higher heat resistance, and increase the application range of epoxy resins. However, due to the overall weak polarity of silicone resin microspheres, when they are mixed with epoxy resins, the compatibility between the two is poor, and phase separation is likely to occur.

[0004] To solve this problem, those skilled in the art mainly adopt the following methods: (1) physically blending and modifying silicone resin microspheres with epoxy resins; (2) adding compatibilizers to the silicone resin microsphere and epoxy resin system. Due to the poor compatibility between silicone resin microspheres and epoxy resins, neither physical mixing nor adding compatibilizers can effectively improve the compatibility between silicone resin microspheres and epoxy resins. Summary of the Invention:

[0005] The purpose of the present invention is to overcome the problem of poor compatibility between silicone resin microspheres and epoxy resins existing in the prior art, and to provide a bisphenol-type silicone resin microsphere, a preparation method thereof, and an application thereof.

[0006] To achieve the above purpose, one of the purposes of the present invention is to provide a bisphenol-type silicone resin microsphere, the bisphenol-type silicone resin microsphere having a core-shell structure, the core being a silicone resin, and the shell being a bisphenol-type silicone resin.

[0007] The D10 of the bisphenol-type silicone resin microsphere is 3.5 - 4 μm, the D50 is 4.5 - 5.5 μm, and the D90 is 7 - 7.5 μm.

[0008] The infrared spectrum of the bisphenol-type silicone resin microspheres has characteristic absorption peaks near 1600 cm -1 , 1500 cm -1 , 1440 cm -1 and 820 cm -1 .

[0009] The second object of the present invention is to provide a method for preparing bisphenol-type silicone resin microspheres, and the method includes:

[0010] 1) In a buffer solution, subject the silane to a first polymerization reaction to obtain a mixed system;

[0011] 2) Add the compound shown in formula (I) to the mixed system to carry out a second polymerization reaction to obtain bisphenol-type silicone resin microspheres.

[0012]

[0013] Wherein, 0≤n≤12; R 1 is selected from one of hydrogen, hydroxyl group, epoxy group, amino group, carboxyl group and halogen; R 2 and R 3 are each independently selected from one of hydrogen or an alkyl group of C 1 ~C 12 ; R 4 , R 5 and R 6 are each independently selected from one of alkyl groups of C 1 ~C 6 .

[0014] The third object of the present invention is to provide bisphenol-type silicone resin microspheres prepared according to the foregoing method.

[0015] The fourth object of the present invention is to provide an application of the bisphenol-type silicone resin microspheres in epoxy resin, polyurethane resin or aspartic polyurea resin.

[0016] Through the above technical solutions, the present invention has the following technical effects:

[0017] 1. The bisphenol-type silicone resin microspheres provided by the present invention have bisphenol groups on the surface, which can improve the compatibility between the silicone resin microspheres and epoxy resin; the alkyl groups can adjust the flexibility of the molecule, further improve the compatibility between the silicone resin microspheres and epoxy resin, and thus improve the anti-settling performance of the silicone resin microspheres in epoxy resin.

[0018] 2. By adding bisphenol-type silane for polymerization reaction after the hydrolysis polymerization of silane, the present invention can prepare silicone resin microspheres with bisphenol groups and alkyl groups on the surface, and effectively reduce the dosage of bisphenol-type silane, saving costs. Description of the Drawings:

[0019] Figure 1 is the SEM image of the bisphenol-based silicone resin microspheres prepared in Example 1 of the present invention;

[0020] Figure 2 is the particle size distribution diagram of the bisphenol-based silicone resin microspheres prepared in Example 1 of the present invention;

[0021] Figure 3 is the infrared spectrum diagram of the prepolymer microspheres C1 and the bisphenol-based silicone resin microspheres A1 in Example 1 of the present invention;

[0022] Figure 4 is the SEM image of the silicone resin prepared in Comparative Example 5 of the present invention. Detailed Embodiments:

[0023] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific examples and illustrations.

[0024] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0025] In the present invention, D10 refers to the particle size at which the particle cumulative distribution is 10%, that is, the volume content of particles smaller than this particle size accounts for 10% of all particles.

[0026] D50 refers to the particle size at which the particle cumulative distribution is 50%.

[0027] D90 refers to the particle size at which the particle cumulative distribution is 90%; that is, the volume content of particles smaller than this particle size accounts for 90% of all particles.

[0028] C 1 ~C 12 The alkyl group refers to an alkyl group containing 1 - 12 carbon atoms.

[0029] C 1 ~C 6 The alkyl group and C 1 ~C 3 The alkyl group is as defined above.

[0030] Unless otherwise specified, the "parts" mentioned in the present invention are all "parts by weight".

[0031] As described above, one of the objectives of the present invention is to provide a bisphenol-based silicone resin microsphere, the bisphenol-based silicone resin microsphere having a core-shell structure, the core of the core-shell structure being a silicone resin and the shell being a bisphenol-based silicone resin.

[0032] According to the present invention, under preferred conditions, the D10 of the bisphenol-based silicone resin microsphere is 3.5 - 4 μm, the D50 is 4.5 - 5.5 μm, and the D90 is 7 - 7.5 μm.

[0033] The infrared spectrum of the bisphenol-based silicone resin microsphere has absorption peaks near 1600 cm -1 , 1500 cm -1 , 1440 cm -1 and 820 cm -1 . Among them, the absorption peaks near 1600 cm -1 , 1500 cm -1 and 1440 cm -1 are the skeletal vibration peaks of the benzene ring of bisphenol A, indicating that there are bisphenol A groups on the silicone resin microsphere. The absorption peak near 820 cm -1 is the absorption peak of para-substitution on the benzene ring, indicating that the para-position on the benzene ring in the bisphenol A group is substituted.

[0034] The value of (D90 - D10) / D50 of the microsphere can illustrate the particle size distribution of the microsphere. The smaller the value of (D90 - D10) / D50, the narrower the overall particle size distribution of the microsphere, that is, the higher the particle size uniformity. According to the present invention, under preferred conditions, the value of (D90 - D10) / D50 of the bisphenol-based silicone resin microsphere is 0.6 - 1; preferably 0.6 - 0.7.

[0035] Furthermore, the specific surface area of the polyether-based silicone resin microsphere provided by the present invention is 0.8 - 1.5 m 2 / g, and the particle size consistency is 0.15 - 0.18. The particle size consistency is obtained by testing with a Malvern MS2000 type laser particle size analyzer.

[0036] Another objective of the present invention is to provide a method for preparing a bisphenol-based silicone resin microsphere, the method comprising:

[0037] 1) In a buffer solution, subject the silane to a first polymerization reaction to obtain a mixed system;

[0038] 2) Add the bisphenol-based silane shown in formula (I) to the mixed system to conduct a second polymerization reaction to obtain a bisphenol-based silicone resin microsphere.

[0039]

[0040] where 0 ≤ n ≤ 12; R1 Selected from one of hydroxyl group, epoxy group, amino group, carboxyl group, halogen, amide group, isocyanate group and ester group; R 2 and R 3 are each independently selected from hydrogen or C 1 ~C 12 alkyl; R 4 , R 5 and R 6 are each independently selected from C 1 ~C 6 alkyl.

[0041] In the present invention, n is a non-negative integer less than 12, for example, it can be 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, etc. Preferably, 0≤n≤6; more preferably, 0≤n≤3.

[0042] In the present invention, the bisphenol-based silane can be bisphenol A-based silane, bisphenol F-based silane, bisphenol D-based silane or modified bisphenol-based silane, and R 1 is selected from one of hydrogen, hydroxyl group, epoxy group, amino group, carboxyl group and halogen.

[0043] In the present invention, when R 1 is hydrogen and n≠0, the group connected to the bisphenol group is an alkyl group; for example, when n = 1, this group is methyl; when n = 2, this group is ethyl.

[0044] In the present invention, R 2 and R 3 can be the same or different. In some preferred embodiments of the present invention, R 2 and R 3 are each independently selected from hydrogen or C 1 ~C 6 alkyl, including but not limited to at least one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, isobutyl, tert-butyl, etc.; preferably, R 2 and R 3 are each independently selected from one of hydrogen, methyl, ethyl and n-propyl.

[0045] In the present invention, R 4 , R 5 and R 6 can be the same or different. In some preferred embodiments of the present invention, R 4 , R 5 and R 6 are each independently selected from C 1 ~C 4 alkyl, including but not limited to one of methyl, ethyl, n-propyl, isopropyl and n-butyl.

[0046] In some preferred embodiments of the present invention, the molecular formula of the silane is shown as formula (IV):

[0047]

[0048] Wherein, R 7 、R 8 and R 9 may be the same or different. Preferably, R 7 、R 8 and R 9 each independently selected from one of C 1 ~C 6 alkyl groups, including but not limited to at least one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, isobutyl, tert-butyl, etc.; more preferably one of C 1 ~C 3 alkyl groups.

[0049] In the present invention, preferably, R 10 is selected from substituted or unsubstituted phenyl, C 1 ~C 6 alkyl, C 1 ~C 6 haloalkyl, C 1 ~C 6 mercaptoalkyl, C 1 ~C 6 alkoxy and C 1 ~C 6 alkenyl; more preferably, R 10 is selected from phenyl, C 1 ~C 3 alkyl, C 1 ~C 3 haloalkyl, C 1 ~C 3 mercaptoalkyl, C 1 ~C 3 alkoxy and C 1 ~C 3 alkenyl. More preferably, R 10 is selected from phenyl, C 1 ~C 3 alkyl, C 1 ~C 3 haloalkyl, C 1 ~C 3 mercaptoalkyl and C 1 ~C 3 alkenyl, including but not limited to at least one of phenyl, methyl, ethyl, n-propyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, chloromethyl, chloroethyl, chloropropyl, vinyl and propenyl.

[0050] In some preferred embodiments of the present invention, the silane may be at least one of phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, chloropropyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, tetraethoxysilane or tetramethoxysilane, and further preferably at least one of phenyltriethoxysilane, ethyltrimethoxysilane and propyltriethoxysilane.

[0051] In the present invention, in step (1), the conditions of the first polymerization reaction include: the temperature is 0 - 90 °C, and the time is 3 - 10 h; under the above conditions, the aforementioned silane can be hydrolyzed and pre-polymerized to form pre-polymerized microspheres; further preferably, the conditions of the first polymerization reaction include: the temperature is 0 - 60 °C, and the time is 3 - 7 h.

[0052] In the present invention, hydrolyzing and polymerizing the silane in a buffer solution can maintain the stability of the pH of the system, making the hydrolysis and polymerization rate of the bisphenol-type silane stable in the buffer solution, thereby synthesizing bisphenol-type organosilicon resin microspheres with good dispersibility; under preferred conditions, the pH value of the buffer solution is 2 - 6 or 8 - 13; further preferably, the pH value of the buffer solution is 3 - 5 or 9 - 12.

[0053] In the present invention, the buffer solution can be known to those skilled in the art as long as its pH value is within the above range. For example, it can be a mixture of a weak acid and its salt, a mixture of a weak base and its salt, or a mixture of an acid salt of a polybasic weak acid and its corresponding secondary salt. Exemplarily, the buffer solution can be an aqueous solution of acetic acid and potassium acetate, a mixed solution of ammonia water and ammonium chloride, or an aqueous solution of sodium dihydrogen phosphate and disodium hydrogen phosphate.

[0054] Under preferred conditions, the method for preparing the bisphenol-type silane shown in formula (I) includes: reacting the compound shown in formula (II) with the compound shown in formula (III) at 40 - 100 °C for 5 - 12 h in the presence of a catalyst.

[0055]

[0056]

[0057] Wherein, 0 ≤ n ≤ 12, preferably 0 ≤ n ≤ 6; further preferably 0 ≤ n ≤ 3;

[0058] R 1 is selected from one of hydrogen, hydroxyl, epoxy, amino, carboxyl and halogen;

[0059] R 2 and R 3 each independently selected from hydrogen or C 1 -C 12 alkyl, preferably hydrogen or C 1 -C 6 alkyl; more preferably, R 2 and R 3 each independently selected from one of hydrogen, methyl, ethyl and n-propyl.

[0060] R 4 、R 5 and R 6 each independently selected from C 1 -C 6 alkyl; preferably C 1 -C 3 alkyl.

[0061] In the present invention, the reaction for preparing the above-mentioned bisphenol-based silane can be carried out under solvent-free conditions or in the presence of a solvent. When carried out in the presence of a solvent, the solvent can be an organic solvent such as benzene, xylene and / or toluene.

[0062] In the present invention, the molar ratio of the compound represented by formula (II) to the compound represented by formula (III) is 1:(0.8 - 1.2).

[0063] Preferably, the catalyst is selected from noble metal catalysts, such as platinum catalysts and / or palladium catalysts.

[0064] According to the present invention, under preferred conditions, in step (2), the weight ratio of the silane to the compound represented by formula (I) is (5 - 40):1; preferably (10 - 25):1, for example, it can be 10:1, 12:1, 15:1, 18:1, 20:1, 25:1 or any ratio within the range composed of any two of the above ratios.

[0065] In the present invention, a bisphenol-based silicone resin coating layer can be formed on the surface of the prepolymer microspheres through a second polymerization reaction. Under preferred conditions, the conditions of the second polymerization reaction include: temperature 0 - 70°C, time 2 - 8 h; more preferably: temperature 0 - 60°C, time 2 - 7 h.

[0066] The third object of the present invention is to provide a bisphenol-based silicone resin microsphere prepared by the method described above. The bisphenol-based silicone resin microsphere has a core-shell structure, with the core being a silicone resin and the shell being a bisphenol-based silicone resin.

[0067] A fourth object of the present invention is to provide an application of bisphenol-type silicone resin microspheres in epoxy resin, polyurethane resin or aspartic polyurea resin.

[0068] The present invention will be described in detail below through examples.

[0069] In the following examples, the particle sizes (D10, D50 and D90) of the microspheres were measured by a Malvern MS2000 laser particle size analyzer.

[0070] In the following examples, the molecular formulas of the raw materials and their corresponding groups are shown in Table 1:

[0071] Table 1

[0072]

[0073] Preparation Example 1

[0074] In the presence of a platinum catalyst, raw material A and trimethoxysilane were mixed evenly in xylene according to a molar ratio of 1:1.05, and then reacted at 70 °C for 8 h. The reaction product was subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, and the bisphenol-type silane shown in formula (V-1) was obtained.

[0075] The reaction equation is as follows:

[0076]

[0077] Preparation Example 2

[0078] In the presence of a platinum catalyst, raw material C and trimethoxysilane were mixed evenly in xylene according to a molar ratio of 1:1.05, and then reacted at 70 °C for 8 h. The reaction product was subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, and the bisphenol-type silane shown in formula (V-2) was obtained.

[0079] The reaction equation is as follows:

[0080]

[0081] Preparation Example 3

[0082] In the presence of a platinum catalyst, raw material B and trimethoxysilane were mixed evenly in xylene according to a molar ratio of 1:1.05, and then reacted at 80 °C for 6 h. The reaction product was subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, and the bisphenol-type silane shown in formula (VI-1) was obtained.

[0083] The reaction equation is as follows:

[0084]

[0085] Preparation Example 4

[0086] In the presence of a platinum catalyst, raw material D and trimethoxysilane are mixed evenly in xylene at a molar ratio of 1:1.05, and then reacted at 80 °C for 6 h. The reaction product is subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, obtaining the bisphenol-type silane shown in formula (VI-2).

[0087] The reaction equation is as follows:

[0088]

[0089] Preparation Example 5

[0090] In the presence of a platinum catalyst, raw material E and trimethoxysilane are mixed evenly in xylene at a molar ratio of 1:1.05, and then reacted at 80 °C for 6 h. The reaction product is subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, obtaining the bisphenol-type silane shown in formula (VII).

[0091] The reaction equation is as follows:

[0092]

[0093] Preparation Example 6

[0094] In the presence of a platinum catalyst, raw material F and trimethoxysilane are mixed evenly in xylene at a molar ratio of 1:1.05, and then reacted at 80 °C for 6 h. The reaction product is subjected to rotary evaporation under reduced pressure to remove the unreacted trimethoxysilane, obtaining the bisphenol-type silane shown in formula (VIII).

[0095] The reaction equation is as follows:

[0096]

[0097] Example 1

[0098] (1) Weigh 75 parts of dipotassium hydrogen phosphate and 6 parts of potassium dihydrogen phosphate, dissolve them in deionized water, and dilute to a pH of 11 to obtain a buffer solution;

[0099] (2) Add 25 parts of ethyltrimethoxysilane to 235 parts of the buffer solution, and react at 40 °C for 4 h under the condition of a stirring speed of 50 r / min to obtain a mixed system containing prepolymer microspheres C1 (D50 is 4.071 μm);

[0100] (3) Add 2 parts of the bisphenol-type silane shown in formula (V-1) to the mixed system, and continue to react at 50 °C for 3 h under the condition of a stirring speed of 400 r / min; wash and centrifuge the reaction product with methanol at a centrifugation speed of 5000 r / min, and then dry at 100 °C for 12 h to obtain bisphenol-type silicone resin microspheres A1.

[0101] The SEM image of the bisphenol-based silicone resin microspheres A1 is as Figure 1 shown, and the particle size distribution is as Figure 2 shown.

[0102] From Figure 1 it can be seen that the bisphenol-based silicone resin microspheres A1 are monodisperse, and the particle size is about 5 μm. From Figure 2 it can be seen that the D50 of the bisphenol-based silicone resin microspheres A1 is about 5 μm. In addition, measured by a laser particle size analyzer, the specific surface area of the bisphenol-based silicone resin microspheres A1 is 1.22 m 2 / g, and the particle size uniformity is 0.2.

[0103] The infrared spectra of the prepolymer microspheres C1 and the bisphenol-based silicone resin microspheres A1 are as Figure 3 shown. From Figure 3 it can be seen that, compared with the infrared spectrum of the prepolymer microspheres C1, the bisphenol-based silicone resin microspheres A1 have absorption peaks near 1600 cm -1 , 1500 cm -1 , 1440 cm -1 and 820 cm -1 . These peaks are the skeletal vibration peaks of the benzene ring of bisphenol A, indicating that bisphenol A groups exist on the silicone resin microspheres; the absorption peak at 910 -1 -920 -1 corresponds to the vibration peak of the epoxy group. The absorption peaks in the range of 1300 - 1050 cm -1 can be attributed to C-O, and the absorption peak near 820 cm -1 is the absorption peak of para-substitution on the benzene ring, indicating that the para-position on the benzene ring in the bisphenol A group is substituted. In summary, bisphenol A groups exist on the surface of the bisphenol-based silicone resin microspheres A1 provided in this example.

[0104] Example 2

[0105] (1) Dissolve 85 parts of acetic acid and 75 parts of potassium acetate in deionized water and dilute to pH 4 to obtain a buffer solution;

[0106] (2) Add 21 parts of phenyltriethoxysilane to 210 parts of the buffer solution, and react at 10 °C for 6 h under the condition of a stirring speed of 40 r / min to obtain a mixed system;

[0107] (3) Add 1 part of the bisphenol-type silane shown in formula (VI-1) to the mixed system, and continue to react at 30 °C for 7 h under the condition that the stirring speed is 200 r / min; wash the product obtained by reaction with methanol and centrifuge at a centrifuge speed of 5000 r / min, and then dry at 90 °C for 11 h to obtain bisphenol-type silicone resin microspheres A2.

[0108] Example 3

[0109] (1) Weigh 20 parts of ammonia water and 15 parts of ammonium chloride, dissolve them in deionized water, and dilute to pH 11 to obtain a buffer solution;

[0110] (2) Add 20 parts of ethyltriethoxysilane to 220 parts of the buffer solution, and react at 0 °C for 4 h under the condition that the stirring speed is 50 r / min to obtain a mixed system;

[0111] (3) Add 1 part of the bisphenol-type silane shown in formula (V-2) to the mixed system, and continue to react at 20 °C for 4 h under the condition that the stirring speed is 400 r / min; wash the product obtained by reaction with methanol and centrifuge at a centrifuge speed of 5000 r / min, and then dry at 110 °C for 12 h to obtain bisphenol-type silicone resin microspheres A3.

[0112] Example 4

[0113] (1) Weigh 65 parts by weight of disodium hydrogen phosphate and 15 parts by weight of sodium dihydrogen phosphate, dissolve them in deionized water, and dilute to pH 11 to obtain a buffer solution;

[0114] (2) Add 21 parts of ethyltrimethoxysilane to 250 parts of the buffer solution, and react at 60 °C for 3 h under the condition that the stirring speed is 20 r / min to obtain a mixed system;

[0115] (3) Add 2 parts of the bisphenol-type silane shown in formula (VI-2) to the mixed system, and continue to react at 30 °C for 5 h under the condition that the stirring speed is 700 r / min; wash the product obtained by reaction with methanol and centrifuge at a centrifuge speed of 5000 r / min, and then dry at 100 °C for 12 h to obtain bisphenol-type silicone resin microspheres A4.

[0116] Example 5

[0117] (1) Weigh 85 parts of acetic acid and 75 parts of sodium acetate, dissolve them in deionized water, and dilute to pH 5 to obtain a buffer solution;

[0118] (2) Add 23 parts of propyltriethoxysilane to 240 parts of the buffer solution, and react at 30 °C for 3 h under the condition that the stirring speed is 60 r / min to obtain a mixed system;

[0119] (3) Add 1 part of the bisphenol-type silane shown in formula (V-1) to the mixed system, and continue to react at 0 °C for 5 h under the condition that the stirring speed is 200 r / min; wash and centrifuge the product obtained from the reaction with methanol at a centrifuge speed of 7000 r / min, and then dry at 90 °C for 11 h to obtain bisphenol-type silicone resin microspheres A5.

[0120] Example 6

[0121] According to the method of Example 4, the difference is that: the bisphenol-type silane shown in formula (VII) is used instead of the bisphenol-type silane shown in formula (VI-2) to obtain bisphenol-type silicone resin microspheres A6.

[0122] Example 7

[0123] According to the method of Example 4, the difference is that: the bisphenol-type silane shown in formula (VIII) is used instead of the bisphenol-type silane shown in formula (VI-2) to obtain bisphenol-type silicone resin microspheres A7.

[0124] Comparative Example 1

[0125] According to the method of Example 2, the difference is that: hydrochloric acid solution with a pH of 4 is used instead of acetic acid / acetic potassium buffer solution to obtain bisphenol-type silicone resin B1.

[0126] Comparative Example 2

[0127] According to the method of Example 1, the difference is that: ethyltrimethoxysilane is used instead of the bisphenol-type silane shown in formula (V-1), and no bisphenol-type silane is added during the preparation process of the silicone resin microspheres; the method is as follows:

[0128] (1) Weigh 75 parts of dipotassium hydrogen phosphate and 6 parts of potassium dihydrogen phosphate, dissolve them in deionized water, and dilute to pH 11 to obtain a buffer solution;

[0129] (2) Add 25 parts of ethyltrimethoxysilane to 235 parts of the buffer solution, and react at 40 °C for 4 h under the condition that the stirring speed is 50 r / min to obtain a mixed system;

[0130] (3) Add 2 parts of ethyltrimethoxysilane to the mixed system, and continue to react at 50 °C for 3 h under the condition that the stirring speed is 400 r / min; wash and centrifuge the product obtained from the reaction with methanol at a centrifuge speed of 5000 r / min, and then dry at 100 °C for 12 h to obtain bisphenol-type silicone resin microspheres B2, and the infrared spectrum of the bisphenol-type silicone resin microspheres B2 is as Figure 3 shown.

[0131] Comparative Example 3

[0132] According to the method of Example 3, the difference is that ethyltriethoxysilane and the bisphenol-type silane shown in formula (V-2) are reacted simultaneously. The specific method is as follows:

[0133] (1) Weigh 20 parts of ammonia water and 15 parts of ammonium chloride, dissolve them in deionized water, and dilute to a pH of 11 to obtain a buffer solution;

[0134] (2) Add 20 parts of ethyltriethoxysilane and 1 part of the bisphenol-type silane shown in formula (V-2) to 220 parts of the buffer solution. Under the condition of a stirring speed of 500 r / min, first react at 0 °C for 4 h, and then continue to react at 20 °C for 4 h; Wash and centrifuge the reaction product with methanol at a centrifuge speed of 5000 r / min, and then dry at 110 °C for 12 h to obtain organosilicon resin microspheres B3.

[0135] Comparative Example 4

[0136] According to the method of Comparative Example 3, the difference is that the dosage ratio of ethyltriethoxysilane to the bisphenol-type silane shown in formula (V-2) is 2:1. The specific method is as follows:

[0137] Add 20 parts of ethyltriethoxysilane and 10 parts of the bisphenol-type silane shown in formula (V-2) to 220 parts of the ammonia water / ammonium chloride buffer solution (pH = 11). Under the condition of a stirring speed of 500 r / min, first react at 0 °C for 4 h, and then continue to react at 20 °C for 4 h; Wash and centrifuge the reaction product with methanol at a centrifuge speed of 5000 r / min, and then dry at 110 °C for 12 h to obtain organosilicon resin microspheres B4.

[0138] Comparative Example 5

[0139] According to the method of Example 1, the difference is that the bisphenol-type silane shown in (V-1) is used instead of ethyltrimethoxysilane. The specific method is as follows:

[0140] (1) Weigh 75 parts of dipotassium hydrogen phosphate and 6 parts of potassium dihydrogen phosphate, dissolve them in deionized water, and dilute to a pH of 11 to obtain a buffer solution;

[0141] (2) Add 25 parts of the bisphenol-type silane shown in formula (V-1) to 235 parts of the buffer solution. Under the condition of a stirring speed of 50 r / min, react at 40 °C for 4 h to obtain a mixed system;

[0142] (3) Add 2 parts of the bisphenol-type silane shown in formula (V-1) to the mixed system. Under the condition of a stirring speed of 400 r / min, continue to react at 50 °C for 3 h; Wash and centrifuge the reaction product with methanol at a centrifuge speed of 5000 r / min, and then dry at 100 °C for 12 h to obtain bisphenol-type organosilicon resin B5.

[0143] Comparative Example 6

[0144] According to the method of Example 1, the difference is that 3-glycidoxypropyltrimethoxysilane is used instead of the bisphenol-type silane shown in (V-1). The specific method is as follows:

[0145] (1) Weigh 75 parts of dipotassium hydrogen phosphate and 6 parts of potassium dihydrogen phosphate, dissolve them in deionized water, and dilute to a pH of 11 to obtain a buffer solution;

[0146] (2) Add 25 parts of dimethyldimethoxysilane to 235 parts of the buffer solution, react at 40 °C for 4 h under the condition of a stirring speed of 50 r / min to obtain a mixed system;

[0147] (3) Add 2 parts of the bisphenol-type silane shown in formula (V-1) to the mixed system, continue to react at 50 °C for 3 h under the condition of a stirring speed of 400 r / min; wash and centrifuge the reaction product with methanol at a centrifuge speed of 5000 r / min, and then dry at 100 °C for 12 h to obtain organosilicon resin microspheres B6.

[0148] Experimental Example

[0149] Respectively mix the bisphenol-type organosilicon resin microspheres synthesized in Examples 1-7 and the organosilicon resins synthesized in Comparative Examples 1-6 with E-51 type liquid epoxy resin in a mass ratio of 25:45, and stir at room temperature for 1 h in a 2 L double planetary mixer to obtain a homogeneous and transparent mixed system. Then let it stand, and observe whether microsphere sedimentation occurs in the mixed system after standing for 30 days and 60 days.

[0150] Table 3

[0151]

[0152] As can be seen from Table 3, the D50 of the bisphenol-type organosilicon resin microspheres prepared in Examples 1 to 5 is about 5 μm, and the value of (D90 - D10) / D50 is 0.65 - 0.7, indicating that its overall particle size distribution is narrow and the particle size uniformity is high; and after mixing with bisphenol-type epoxy resin E51, the dispersion is still very uniform after standing for 30 days and 60 days, and no sedimentation occurs, indicating that the bisphenol-type organosilicon resin microspheres prepared in Examples 1 to 5 all have good compatibility with bisphenol-type epoxy resin.

[0153] By comparing Examples 3, 4, 6 and 7, it can be seen that when R 1When it is epoxy group (Example 4) or hydroxyl group (Example 3), the value of (D90 - D10) / D50 of the silicone resin microspheres is about 0.65, and there is no sedimentation even after standing for 120 days in the epoxy resin system; while when R 1 is amino group (Example 7), the value of (D90 - D10) / D50 of the silicone resin microspheres is 0.866, that is, the particle size uniformity of the silicone resin microspheres A7 is poorer than that of the silicone resin microspheres A4; when the group connected to the bisphenol group is alkyl group (Example 6, R 1 is hydrogen and n≠0), the value of (D90 - D10) / D50 of the silicone resin microspheres is 1.02, that is, the particle size uniformity of the silicone resin microspheres A6 is poorer than that of the silicone resin microspheres A7.

[0154] It can be seen from the comparison between Example 2 and Comparative Example 1 that the particle size distribution of the bisphenol - type silicone resin microspheres prepared in the buffer system (Example 2) is more uniform.

[0155] It can be seen from the comparison between Example 3 and Comparative Example 2 that no bisphenol - type silane was added in Comparative Example 2, and the synthesized silicone resin microspheres B2 were poorly dispersed in the E - 51 type liquid epoxy resin system and sedimented after standing for 30 days.

[0156] It can be seen from the comparison between Example 3 and Comparative Example 3 that if the bisphenol - type silane and ethyltriethoxysilane are reacted simultaneously, the prepared silicone resin microspheres are poorly dispersed in the E - 51 type liquid epoxy resin system and sedimented after standing for 30 days.

[0157] It can be seen from the comparison between Example 3 and Comparative Example 4 that if the bisphenol - type silane and ethyltriethoxysilane are reacted simultaneously, compared with Example 3, the dosage of the bisphenol - type silane needs to be increased by 10 times to obtain silicone resin microspheres with good dispersibility, that is, the production cost also increases significantly.

[0158] Figure 4 is the SEM image of the silicone resin microspheres prepared in Comparative Example 5; from Figure 4 it can be seen that only using the bisphenol - type silane for the polymerization reaction results in a poor ball - forming rate of the product and poor dispersibility in the E - 51 type liquid epoxy resin system.

[0159] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments. What is described in the above - mentioned embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A method for preparing bisphenol-based silicone resin microspheres, characterized in that, the method comprises: 1) In a buffer solution, subjecting a silane to a first polymerization reaction to obtain a mixed system containing prepolymer microspheres; the pH value of the buffer solution is 2 - 6 or 8 - 13; the molecular formula of the silane is as shown in formula (IV): Among them, R 7 , R 8 and R 9 are each independently selected from one of C 1 to C 6 alkyl groups; R 10 is selected from substituted or unsubstituted phenyl, C 1 to C 6 alkyl, C 1 to C 6 haloalkyl, C 1 to C 6 mercaptoalkyl, C 1 to C 6 alkoxy and C 1 to C 6 alkenyl; 2) Adding a bisphenol-based silane shown in formula (I) to the mixed system to carry out a second polymerization reaction to obtain bisphenol-based silicone resin microspheres; where 0 ≤ n ≤ 12; R 1 is selected from one of a hydroxyl group, an epoxy group, an amino group, a carboxyl group, a halogen, an amide group, an isocyanate group, and an ester group; R 2 and R 3 are each independently selected from hydrogen or a C 1 -C 12 alkyl group; R 4 , R 5 and R 6 are each independently selected from a C 1 -C 6 alkyl group.

2. The method according to claim 1, characterized in that: the bisphenol-based silicone resin microspheres have a core-shell structure, the core is a silicone resin, and the shell is a bisphenol-based silicone resin.

3. The method according to claim 1, characterized in that: the D10 of the bisphenol-based silicone resin microspheres is 3.5 - 4 μm, the D50 is 4.5 - 5.5 μm, and the D90 is 7 - 7.5 μm.

4. The method according to claim 3, characterized in that: the (D90 - D10) / D50 value of the bisphenol-based silicone resin microspheres is 0.6 - 0.

7.

5. The method according to claim 1, characterized in that: The specific surface area of the bisphenol-type silicone resin microspheres is 0.8 - 1.5 m 2 / g.

6. The method according to claim 1, characterized in that: The infrared spectrum of the bisphenol-based silicone resin microspheres has characteristic absorption peaks near 1600 cm -1 , 1500 cm -1 , 1440 cm -1 and 820 cm -1 positions.

7. The method according to claim 1, characterized in that: R 7 , R 8 and R 9 Each independently selected from C 1 ~C 3 One of the alkyl groups; R 10 Selected from phenyl, C 1 ~C 3 alkyl, C 1 ~C 3 haloalkyl, C 1 ~C 3 mercaptoalkyl, C 1 ~C 3 alkoxy and C 1 ~C 3 one of alkenyls.

8. The method according to claim 1, characterized in that: the conditions of the first polymerization reaction include: temperature is 0 - 90 °C, and time is 3 - 10 h.

9. The method according to claim 1, characterized in that: the weight usage ratio of the silane to the compound shown in formula (I) is (5 - 40):

1.

10. The method according to claim 1, characterized in that: the conditions of the second polymerization reaction include: temperature is 0 - 70 °C, and time is 2 - 8 h.

11. The method according to claim 8, characterized in that: the conditions of the first polymerization reaction include: temperature is 0 - 60 °C, and time is 3 - 7 h.

12. The method according to claim 1, characterized in that: the pH value of the buffer solution is 3 - 5 or 9 - 12.

13. The method according to claim 9, characterized in that: the weight usage ratio of the silane to the compound shown in formula (I) is (10 - 25):

1.

14. The method according to claim 10, characterized in that: the conditions of the second polymerization reaction include: temperature is 0 - 60 °C, and time is 2 - 7 h.

15. The method according to claim 1, characterized in that: 0≤n≤6。 16. The method according to claim 15, characterized in that: 0≤n≤3。 17. The method according to claim 1, characterized in that: R 2 and R 3 each independently selected from hydrogen or C 1 ~C 6 alkyl group.

18. The method according to claim 1, characterized in that: R 4 , R 5 and R 6 Each independently selected from C 1 ~C 4 One of the alkyl groups.

19. The method according to claim 1, characterized in that: The method for preparing the bisphenol-based silane shown in formula (I) comprises: reacting a compound shown in formula (II) with a compound shown in formula (III) at 40 - 100 °C for 5 - 12 h in the presence of a catalyst; wherein, 0 ≤ n ≤ 12; R 1 selected from one of hydrogen, hydroxyl, epoxy, amino, carboxyl and halogen; R 2 and R 3 each independently selected from hydrogen or C 1 ~C 12 alkyl; R 4 、R 5 and R 6 each independently selected from C 1 ~C 6 alkyl group.

20. The method according to claim 19, characterized in that: 0≤n≤6。 21. The method according to claim 20, It is characterized in that: 0≤n≤3。 22. The method according to claim 19, It is characterized in that: R 2 and R 3 each independently selected from hydrogen or C 1 ~C 6 alkyl of one kind.

23. The method according to claim 19, It is characterized in that: R 4 , R 5 and R 6 Each independently selected from C 1 ~C 3 One of the alkyl groups.

24. The method according to claim 19, It is characterized in that: The molar ratio of the compound shown in formula (II) to the compound shown in formula (III) is 1:(0.8 - 1.2).

25. The method according to claim 19, It is characterized in that: The catalyst is selected from noble metal catalysts.

26. The bisphenol-based silicone resin microspheres prepared by the method according to any one of claims 1 - 25.

27. The application of the bisphenol-based silicone resin microspheres according to claim 26 in epoxy resin, polyurethane resin or aspartic polyurea resin.

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