A self-crosslinking epoxy silicone oil and its preparation method and application

Abstract

The present invention discloses a self-crosslinkable epoxy silicone oil and its preparation method and application, which is a side epoxy silicone oil with a terminal amide group. Using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double head as raw materials, terminal primary amino side hydrogen silicone oil is first synthesized by ring-opening polymerization; the terminal amino group of the silicone oil is amidated; then a side epoxy group is introduced by a side hydrogen silylation reaction, and the obtained epoxy silicone oil has an amide terminal group, which does not react with the side epoxy group at room temperature and lower temperature conditions, and can therefore be reprocessed and stably stored; the terminal amide group can react with the epoxy group under high temperature conditions, and belongs to a high-temperature self-crosslinking silicone material with a single-component high-temperature curing property. The epoxy silicone oil disclosed by the present invention can be used as a single-component high-temperature curing adhesive or resin matrix. The reaction conditions used in the preparation are mild, the raw materials are all industrial bulk goods, cheap and easy to obtain, the preparation process is simple, and it is suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to a self-crosslinkable epoxy silicone oil, a preparation method and application thereof, and in particular to a terminal amide epoxy silicone oil, a preparation method and application thereof, belonging to the field of organosilicon preparation and organosilicon material application. Background Art

[0002] As is well known, single-component silicone adhesives cure by moisture. They cure through hydrolysis of the alkoxysilanes contained in the system with trace amounts of water in the air to form silanols, followed by dehydration condensation between the silanols and the silanols. However, the curing process is dependent on the water content in the air and is uncontrollable. Furthermore, the byproduct alcohols generated by the hydrolysis of the alkoxy groups during curing can remain in the system or evaporate into the environment, raising significant environmental concerns. Decarboxylation-type silicone adhesives, while fast curing, produce a pungent odor from the organic carboxylic acid byproduct during the curing process.

[0003] Starting with epoxy-containing silicone oil, adding a primary or secondary amine crosslinker can cause an addition reaction with the epoxy groups. This process, similar to epoxy resin curing, does not release small molecule byproducts. However, when a tertiary amine is added, it cannot add to the epoxy groups, but it can catalyze the ring-opening homopolymerization of the epoxy groups via an ionic polymerization process. This is because the nitrogen atom of the tertiary amine has an unshared electron pair, making it nucleophilic and a proton acceptor. The electron-donating effect of the alkyl group in the tertiary amine gives it a strong electronegativity. This easily attacks the Cδ+ atom of the epoxy group, forming a negative oxygen ion. This oxygen ion can then continuously catalyze the ring-opening reaction of other epoxy groups, leading to chain extension or crosslinking. However, this process requires the addition of an ammonia (or amine) as an external crosslinker or curing catalyst to the curing formula before use. Summary of the Invention

[0004] The present invention discloses a novel self-crosslinking curable epoxy silicone oil, which contains an amide group at the end. The amide group has poor reactivity with the epoxy group at a relatively low temperature, but can undergo a ring-opening addition reaction with the epoxy group at a high temperature, thereby forming a single-component self-crosslinking curable epoxy silicone oil.

[0005] The technical solution for achieving the purpose of the present invention is:

[0006] A self-crosslinkable epoxy silicone oil, which is an epoxy silicone oil with a terminal amide group, has the following specific structure:

[0007]

[0008] Wherein, R is an alkyl group, preferably one of methyl, ethyl, propyl, pentyl, heptyl, undecyl, and heptadecyl; x = an integer of 5 to 500; y = an integer of 1 to 200.

[0009] The present invention discloses a method for preparing the self-crosslinkable epoxy silicone oil, comprising the following steps:

[0010] (1) Using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double capping as raw materials, terminal primary amino side hydrogen silicone oil was prepared by ring-opening polymerization;

[0011] (2) amidating the terminal primary amino side hydrogen silicone oil to obtain the terminal amide side hydrogen silicone oil;

[0012] (3) The terminal amide side hydrogen silicone oil is subjected to a silylation reaction with an epoxy compound to obtain a self-crosslinking epoxy silicone oil.

[0013] In the present invention, the dimethylcyclosiloxane monomer is one of octamethylcyclotetrasiloxane and mixed dimethylcyclosiloxane (DMC); the amino double head is 1,3-bis(aminopropyl)tetramethyldisiloxane; and the weight ratio of the dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double head is 800:1-100:1-100.

[0014] In the present invention, the amidation reagent includes an acyl chloride; the amidation is carried out in the presence of triethylamine, and the weight ratio of the amino-terminated pendant hydrogen silicone oil, triethylamine, and acyl chloride is 800:2-50:5-200. Furthermore, the amidation is carried out in a solvent, wherein the solvent is any one of toluene and xylene; and the acyl chloride is any one of acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, octanoyl chloride, lauroyl chloride, and octadecanoyl chloride. During the terminal amidation, the temperature is 0-25°C when the acyl chloride is added dropwise. After the addition is completed, the temperature is naturally raised to room temperature for reaction, and the reaction is carried out for 1-24 hours, preferably 3-15 hours. After the amidation is completed, the reaction solution is washed with water and dried to obtain the amino-terminated pendant hydrogen silicone oil; wherein the drying is performed using anhydrous sodium sulfate or anhydrous magnesium sulfate.

[0015] In the present invention, the hydrosilylation reaction is carried out in the presence of a platinum catalyst; the weight ratio of the terminal amide side hydrogen silicone oil, the epoxy compound, and the platinum catalyst is 10-1000:1-100:1.0×10 -4 ~1.0×10 -2 The weight of the platinum catalyst is based on the net weight of Pt. The epoxy compound includes allyl glycidyl ether.

[0016] In the present invention, the ring-opening polymerization temperature is 50-110° C., and the time is 1-24 hours, preferably 3-10 hours; the amidation reaction time is 1-24 hours, preferably 3-10 hours; the hydrosilylation reaction temperature is 50-85° C., and the time is 1-8 hours.

[0017] The invention discloses the application of the self-crosslinkable epoxy silicone oil in the preparation of organosilicon materials.

[0018] The present invention discloses an organosilicon material obtained by curing the self-crosslinkable epoxy silicone oil described above; or by curing the self-crosslinkable epoxy silicone oil by mixing it with other reagents. The organosilicon material is obtained by heating the self-crosslinkable epoxy silicone oil to undergo self-crosslinking and curing; or by curing the self-crosslinkable epoxy silicone oil by mixing it with other reagents. Preferably, the curing temperature is 120-180°C for 30 minutes to 5 hours.

[0019] The invention uses dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double-capped end as raw materials to prepare terminal primary amino side hydrogen silicone oil through ring-opening polymerization; then the terminal primary amino group of the silicone oil reacts with acyl chloride to amidate the terminal amino group and reduce its activity; then the side hydrogen reacts with allyl glycidol to undergo a silylation reaction to introduce an epoxy group into the side chain of the silicone oil, thereby producing a self-crosslinking epoxy silicone oil. The product can be stored for more than 6 months without changing its properties under room temperature conditions, and will solidify and crosslink if heated to a high temperature, thus becoming a high-temperature self-crosslinking epoxy silicone oil material.

[0020] The specific steps are:

[0021] (1) Ring-opening polymerization: In a reactor, dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double-capped end are mixed, tetramethylammonium hydroxide is added, and the temperature is raised to react to obtain terminal amino side hydrogen silicone oil; the reaction formula of ring-opening polymerization is as follows:

[0022]

[0023] wherein m = 4 or an integer of 3 to 6; x = an integer of 5 to 500, preferably 100 to 400, more preferably 100 to 300; and y = an integer of 1 to 200, preferably 10 to 150, more preferably 30 to 100.

[0024] (2) End group amidation: In a reactor, the terminal primary amino side hydrogen silicone oil is dissolved in a solvent, triethylamine is added as an acid binding agent, and then acyl chloride is added dropwise to react. After the reaction is completed, post-treatment (water washing and drying) is performed to obtain the terminal amide side hydrogen silicone oil; the amidation reaction formula is as follows:

[0025]

[0026] (3) Hydrosilylation: In the reactor, the above-mentioned terminal amide side hydrogen silicone oil undergoes a hydrosilylation reaction with allyl glycidyl ether to obtain terminal amide epoxy silicone oil; the hydrosilylation reaction formula is as follows:

[0027]

[0028] In the above chemical formula, R = one of methyl, ethyl, propyl, pentyl, heptyl, undecyl, and heptadecyl; x = an integer of 5 to 500, preferably 100 to 400, more preferably 100 to 300; y = an integer of 1 to 200, preferably 10 to 150, more preferably 30 to 100.

[0029] (4) Curing: Heat the silicone oil at high temperature for a certain period of time to cross-link and cure the silicone oil.

[0030] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0031] The amide-terminated epoxy silicone oil disclosed in this invention combines amide and epoxy groups on the same macromolecular chain. While the two groups do not react at low temperatures and are stable under room temperature, they undergo cross-linking and curing upon heating to elevated temperatures. Therefore, they are suitable for high-temperature, one-component silicone adhesives or adhesives.

[0032] 2. The epoxy silicone oil disclosed in this invention can control the crosslink density formed during high-temperature curing by adjusting the pendant epoxy group content in its molecular structure. The crosslink density can also be adjusted by the molecular weight of the epoxy silicone oil. Unlike conventional epoxy silicone oils that incorporate amine crosslinkers, the crosslinked structure formed by this addition reaction is not affected by the amount of crosslinker in the formulation (e.g., added ammonia or amine).

[0033] 3. The reaction conditions used in the preparation of epoxy silicone oil in the present invention are mild, the raw materials are cheap and easily available, the preparation process is simple, and it is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 and Figure 2 This is the hydrogen nuclear magnetic spectrum of the terminal acetamide side hydrogen silicone oil and the terminal acetamide epoxy silicone oil prepared in Example 1 of the present invention.

[0035] Figure 3 and Figure 4 This is the hydrogen nuclear magnetic spectrum of the terminal lauryl amide pendant hydrogen silicone oil and the terminal lauryl amide epoxy silicone oil prepared in Example 2 of the present invention.

[0036] Figure 5 and Figure 6 These are optical photographs of epoxy silicone oil high-temperature cross-linking films prepared in Example 1 and Example 2 of the present invention. DETAILED DESCRIPTION

[0037] The preparation process of the self-crosslinkable epoxy silicone oil of the present invention comprises:

[0038] (1) Ring-opening polymerization: Using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double capping as raw materials, terminal primary amino side hydrogen silicone oil is prepared by ring-opening polymerization;

[0039] (2) Terminal amidation: Dissolve the terminal primary amino side hydrogen silicone oil in a solvent, add acyl chloride to amidate the terminal amino group, and then post-treat to obtain the terminal amide side hydrogen silicone oil;

[0040] (3) Hydrosilylation: Further hydrosilylation reaction with allyl glycidol occurs through the side group silicon-hydrogen bond, and epoxy groups are introduced into the side chain of the silicone oil to obtain the self-crosslinkable epoxy silicone oil, which is a terminal amide epoxy silicone oil;

[0041] (4) Further curing: heating the self-crosslinkable epoxy silicone oil for a certain period of time and curing at high temperature to obtain an organosilicon material.

[0042] Preferably, in the preparation step (2) of the terminal amidation, the solvent used is any one of toluene or xylene; the acyl chloride is any one of acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, octanoyl chloride, lauroyl chloride, and octadecanoyl chloride. Preferably, in the terminal amidation, the weight ratio of amino-terminated side hydrogen silicone oil: solvent: triethylamine (TEA): acyl chloride is 800:100-800:2-50:5-200. The temperature during the dropwise addition of the acyl chloride is 0-25°C. After the dropwise addition is completed, the reaction solution is allowed to naturally warm to room temperature and the reaction is carried out for a total of 1-24 hours.

[0043] Furthermore, in the preparation step (2) of terminal amidation, the reaction solution is washed with water 4 to 6 times during post-treatment, and then dried with a desiccant; the desiccant is either anhydrous sodium sulfate or anhydrous magnesium sulfate. Preferably, during post-treatment, the reaction solution: deionized water: desiccant (by weight) is 10:1 to 10:0.1 to 1.

[0044] The technical solution of the present invention is further described below with reference to the accompanying drawings and examples. The raw materials and reagents used are all existing products, and the specific preparation operations and performance tests are all conventional techniques. Example 1

[0045] (1) Ring-opening polymerization: A 2L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. 742.0g of commercially available industrial-grade mixed cyclosiloxane DMC, 30.1g of tetramethylcyclotetrasiloxane, and 12.4g of amino double-capped (1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane) were added; then 0.8g of tetramethylhydroxylamine was added at 90°C and the reaction was kept warm for 5h to obtain 779.5g of a colorless, transparent product, which was an amino-terminated side hydrogen silicone oil.

[0046] (2) Terminal acetamidate: 350 g of toluene and 11.1 g of triethylamine (TEA) were added to the above-mentioned terminal amino side hydrogen silicone oil. After stirring and dissolving, 17.4 g of acetyl chloride was added dropwise at 5-8 ° C. The addition was completed within 30 minutes. The reaction was continued by stirring, and the cooling bath was removed. The reaction solution was allowed to naturally rise to room temperature. The reaction was continued for 5 hours. During this period, in addition to achieving the amidation of the primary amino group, the alkaline catalyst tetramethylhydroxylamine added during the ring-opening polymerization was also neutralized. The final reaction solution was washed with water 200 g × 4 times. After washing, 20 g of anhydrous sodium sulfate was added to the oil layer and dried for 2 hours. The desiccant was filtered out and the filtrate was transferred to a 2 L single-necked flask. The solvent was evaporated and degassed under magnetic stirring at 100 ± 5 ° C and 40 mmHg vacuum for 2 hours to obtain 745.1 g of colorless and transparent terminal acetamido side hydrogen silicone oil with a yield of 93.9%. Product FT-IR(n): 2980, 2921 (CH3, CH2), 2119 (Si-H), 1652 (NHC=O), 1266 (Si-CH3), 1050-1062 (Si-O-Si) cm -1 . 1 H NMR (CDCl3): d 4.68 (Si- H );1.56(-C H 3); 0.19~0.06(Si-C H 3) ppm. The reason why amide hydrogen was not detected was that there were only two amide groups at the ends of the polymer chain, their concentration was low, and NH was active and easily exchanged by deuterium atoms.

[0047] (3) Hydrosilylation: A 2L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. Under nitrogen protection, 705.0 g of the above-mentioned terminal acetamide side hydrogen silicone oil was added in sequence. 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. 51.3 g of allyl glycidyl ether was added dropwise through a dropping funnel under stirring. The addition was completed in about 1 hour. After the addition was completed, the reaction was kept warm for 3 hours. After stopping the reaction, the reaction was cooled to obtain 741.1 g of a light yellow transparent terminal acetamide epoxy silicone oil product with a yield of 97.9%. Product FT-IR (n): 2981, 2921 (CH3, CH2), 1655 (NHC=O), 1265 (Si-CH3), 1051-1063 (Si-O-Si) cm -1 . 1 H NMR (CDCl3): d 3.47~1.58 (epoxy H );1.55(-C H 3); 0.09~0.05(Si-C H3) ppm. The product's number average molecular weight (Mn) was measured to be 15190, and its epoxy value was 3.86 mmol / g. After drying 9.995 g of the silicone oil at 105°C for 2 hours, the residual mass was weighed to be 9.961 g. The volatile content of the sample was calculated to be 3.4%.

[0048] The chemical structure of the product is:

[0049]

[0050] After the prepared epoxy silicone oil was stored at room temperature for 6 months, the number average molecular weight was tested to be 15210 and the epoxy value was 3.85 mmol / g, indicating that the product did not denature after long-term storage.

[0051] (4) High temperature heating curing: Take 10.0g of the product silicone oil and spread it on a surface dish with a diameter of 10cm. After drying at 155℃ for 3h, a light yellow transparent film is obtained. The silicone oil is completely cured and the surface is not sticky. Take another 10.0g of the product silicone oil and spread it on a surface dish with a diameter of 10cm. Add a solution prepared by dissolving 0.01g of potassium hydroxide in 0.5g of isopropanol. After manual stirring, apply the film and dry it at 155℃ for 30min to obtain a slightly white elastic silicone film ( Figure 5 ), the elongation at break of the film was measured to be 320%. Example 2

[0052] (1) The preparation of terminal amino side hydrogen silicone oil by ring-opening polymerization is the same as in Example 1.

[0053] (2) Terminal lauryl amidation: The above-mentioned terminal amino side hydrogen silicone oil was transferred to a 2L four-necked reaction flask, and 355g of xylene and 11.1g of triethylamine (TEA) were added. After stirring and dissolving, 43.8g of lauryl chloride was added dropwise at 5-8°C for 50 minutes. After the addition was completed, the reaction was continued to stir and react, and the cooling bath was removed to allow the reaction solution to naturally warm to room temperature. The reaction was continued for 5 hours. The reaction solution was then washed with water 220g × 5 times. After washing, 20g of anhydrous sodium sulfate was added to the oil layer and dried for 2 hours. The desiccant was filtered and the filtrate was transferred to a 2L single-necked flask. The solvent was evaporated and desorbed for 2 hours under magnetic stirring at 100±5°C and 40mmHg vacuum to obtain 752.5g of colorless and transparent terminal lauryl amide side hydrogen silicone oil with a yield of 92.1%. Product FT-IR(n): 2986, 2928 (CH3, CH2), 2120 (Si-H), 1654 (NHC=O), 1265 (Si-CH3), 1051-1064 (Si-O-Si) cm -1 . 1 H NMR (CDCl3): d 4.70 (Si- H );1.58(-C H3); 0.19-0.06 (Si-C H 3)ppm.

[0054] (3) Hydrosilylation: A 2 L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. Under nitrogen protection, 701.0 g of the above-mentioned terminal lauryl amide side hydrogen silicone oil was added in sequence. 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. 53.8 g of allyl glycidyl ether was added dropwise through a dropping funnel under stirring. The addition was completed in about 1 hour. After the addition was completed, the reaction was kept warm for 3 hours. After stopping the reaction, the reaction was cooled to obtain 743.7 g of a slightly yellow transparent terminal lauryl amide epoxy silicone oil product with a yield of 98.5%. Product FT-IR (n): 2986, 2930 (CH3, CH2), 1654 (NHC=O), 1265 (Si-CH3), 1059-1070 (Si-O-Si) cm -1 . 1 H NMR (CDCl3): d 3.48~2.56 (epoxy H ); 1.55 (-C H 3); 0.09~0.05 (-C H 2C H 2-C H 2-);0.12(Si-C H 3) ppm. The product's number average molecular weight (Mn) was measured to be 15660, and its epoxy value was 3.81 mmol / g. After drying 10.002 g of the silicone oil at 105°C for 2 hours, the residual mass was weighed to be 9.977 g. The volatile content of the sample was calculated to be 2.5%.

[0055] The chemical structure of the product is:

[0056]

[0057] After the product was stored at room temperature for 6 months, the re-measured number average molecular weight was 15600, and the epoxy value was 3.83 mmol / g. The product did not denature after storage.

[0058] (4) High temperature heating curing: Take 10.0g of the product silicone oil and spread it on a glass surface dish with a diameter of 10cm. After drying at 145℃ for 3h, a transparent film is obtained. The silicone oil is completely cured and the surface is not sticky. Take another 10.5g of the product silicone oil and spread it on a glass surface dish with a diameter of 10cm. Add a solution prepared by dissolving 0.01g of potassium hydroxide in 0.5g of isopropanol. After manually stirring, apply the film and dry it at 125℃ for 1h to obtain a slightly white silica gel film ( Figure 6 ), the film is soft, and the elongation at break of the film is measured to be 383%. Example 3

[0059] (1) Ring-opening polymerization: A 2 L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. 927.0 g of commercially available industrial-grade mixed cyclosiloxane DMC, 30.0 g of tetramethylcyclotetrasiloxane, and 12.5 g of aminopropyl double-capped siloxane were added. 0.9 g of tetramethylhydroxylamine was added at 90°C. After incubation for 5 h, the reaction was stopped and the temperature was lowered to obtain 843.5 g of a colorless, transparent product, which was a terminal aminopropyl pendant hydrogen silicone oil.

[0060] (2) End group amidation: The above-mentioned terminal amino side hydrogen silicone oil was transferred to a 2L four-necked reaction flask, and 350g of toluene and 11.1g of triethylamine (TEA) were added. After stirring and dissolving completely, 15.1g of acetyl chloride was added dropwise at 5-8°C for 30 minutes. After the addition was completed, the reaction was continued to stir, and the cooling bath was removed, and the reaction solution was allowed to naturally warm to room temperature and reacted for a total of 5 hours. The reaction solution was then washed with water 200g × 4 times. After washing, 20g of anhydrous sodium sulfate was added to the oil layer and dried for 2 hours. The desiccant was filtered and the filtrate was transferred to a 2L single-necked flask. The solvent was evaporated and the solution was stripped for 2 hours at 100±5°C and 40mmHg vacuum under magnetic stirring to obtain 778.5g of colorless and transparent terminal acetamide side hydrogen silicone oil with a yield of 91.0%.

[0061] (3) Hydrosilylation: A 2L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. Under nitrogen protection, 703.0 g of the above-mentioned terminal acetamide side hydrogen silicone oil was added in sequence. 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. 42.2 g of allyl glycidyl ether was added dropwise through a dropping funnel under stirring. The addition was completed in about 1 hour. After the addition was completed, the reaction was kept warm for 3 hours. After stopping the reaction, the mixture was cooled to obtain 730.3 g of a light yellow transparent product with a yield of 98.0%. The number average molecular weight (Mn) of the product was measured to be 18890, and the epoxy value was 3.02 mmol / g. 10.003 g of the product silicone oil was dried at 105°C for 2 hours. The residual mass was weighed to be 9.970 g, and the volatile content of the sample was calculated to be 3.3%.

[0062] The chemical structure of the product is:

[0063]

[0064] (4) High-temperature curing: 10.0 g of the silicone oil was spread on a 10 cm diameter watch glass. After drying at 145 °C for 3 h, a transparent film was obtained. The silicone oil was completely cured and the surface was not sticky. 10.8 g of the silicone oil was spread on a 10 cm diameter watch glass. A solution of 0.01 g potassium hydroxide dissolved in 0.5 g isopropyl alcohol was added. After manual stirring, the solution was dried at 125 °C for 1 h to obtain a slightly yellowish, soft, elastic film.

[0065] Comparative Example 1

[0066] (1) Ring-opening polymerization: A 2L four-necked reaction flask was equipped with an electric heating mantle, reflux condenser, thermometer, and mechanical stirring. 933.0g of commercially available industrial-grade mixed cyclosiloxane DMC, 31.6g of tetramethylcyclotetrasiloxane, and 12.9g of aminopropyl double-capped siloxane were added. 1.0g of tetramethylhydroxylamine was added at 90°C and the reaction was kept warm for 5h. 0.8g of acetic acid was then added for neutralization and reaction for 1h. Filtering was performed to obtain 851.1g of colorless, transparent filtrate, which was terminal aminopropyl pendant hydrogen silicone oil, which was subjected to direct hydrosilylation.

[0067] (2) Silicone Hydrogenation: 705 g of terminal amino-side hydrogenated silicone oil was transferred to a 2 L four-necked reaction flask equipped with an electric heating jacket, reflux condenser, thermometer, and mechanical stirring. Under nitrogen protection, 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70 ° C. 51.5 g of allyl glycidyl ether was added dropwise through a dropping funnel with stirring. After the addition was completed, the mixture was kept warm for 3 h. After stopping the reaction, the mixture was cooled to obtain 750.9 g of a light yellow transparent gel product. The epoxy value of the product was measured to be 0.08 mmol / g. This indicates that while the unsaturated bonds in glycidyl allyl ether reacted with the silicon hydrogen group, the epoxy group also underwent ring-opening addition with the primary amino group at the end of the silicone oil, resulting in cross-linking and gelation of the product.

[0068] Prior art suggests that epoxy groups and primary amino groups cannot coexist in the same polymer chain because primary amino groups are highly basic and can undergo addition reactions with epoxy groups at room temperature or even below 0°C. This invention, focusing on the molecular structure of silicone oils, discloses a side-chain epoxy silicone oil with terminal amide groups. Because the electron-withdrawing effect of the -C=O in the amide group affects the basicity of the -NH- group, the terminal amide group is much less reactive than primary and secondary amines, making the reaction between epoxy and amide groups difficult at room temperature. For example, acetamide and epoxy groups only react at 150°C. This invention reduces the reactivity of primary amino groups by amidating them, thereby concentrating the epoxy and amide groups on the same polysiloxane macromolecule. While terminal amide groups rarely react with side-chain epoxy groups at room temperature or low temperatures, they can undergo a ring-opening addition reaction at high temperatures, resulting in a single-component, self-crosslinking, curable epoxy silicone oil. Specifically, the present invention discloses a method for preparing a self-crosslinkable epoxy silicone oil, the preparation process comprising: (1) ring-opening polymerization: using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double capping as raw materials, preparing terminal primary amino side hydrogen silicone oil by ring-opening polymerization; (2) terminal amidation: dissolving the terminal primary amino side hydrogen silicone oil in a solvent, adding acyl chloride, amidating the terminal amino group, and then post-processing to obtain terminal amide side hydrogen silicone oil; (3) silylation: further reacting the side group silane-hydrogen bond with allyl glycidol to introduce an epoxy group into the silicone oil side chain. (4) curing: heating the terminal amide epoxy silicone oil for a certain period of time and curing at high temperature.

Claims

1. A self-crosslinkable epoxy silicone oil, characterized in that, The chemical structural formula of the self-crosslinkable epoxy silicone oil is as follows: ； Wherein, R is an alkyl group; x = 5 to 500; y = 10 to 150.

2. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 1, wherein The following steps are involved: (1) Using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double capping as raw materials, terminal primary amino side hydrogen silicone oil was prepared by ring-opening polymerization; (2) amidating the terminal primary amino side hydrogen silicone oil to obtain the terminal amide side hydrogen silicone oil; (3) The terminal amide side hydrogen silicone oil is subjected to a silylation reaction with an epoxy compound to obtain a self-crosslinking epoxy silicone oil.

3. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 2, wherein: The dimethylcyclosiloxane monomer is one of octamethylcyclotetrasiloxane and mixed dimethylcyclosiloxane; the amino double head is 1,3-bis(aminopropyl)tetramethyldisiloxane; and the weight ratio of the dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double head is 800:1-100:1-100.

4. The method for preparing a self-crosslinkable epoxy silicone oil according to claim 2, wherein The amidation reagent includes acyl chloride; the amidation is carried out in the presence of triethylamine, and the weight ratio of amino-terminated pendant hydrogen silicone oil, triethylamine and acyl chloride is 800:2-50:5-200.

5. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 2, wherein: The hydrosilylation reaction is carried out in the presence of a platinum catalyst; the weight ratio of the terminal amide side hydrogen silicone oil, the epoxy compound, and the platinum catalyst is 10-1000:1-100:1.0×10 -4 ~1.0×10 -2 .

6. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 2, wherein: The ring-opening polymerization temperature is 50-110° C., and the time is 1-24 hours; the amidation reaction time is 1-24 hours; and the hydrosilylation reaction temperature is 50-85° C., and the time is 1-8 hours.

7. Use of the self-crosslinkable epoxy silicone oil according to claim 1 in the preparation of organosilicon materials.

8. An organosilicon material obtained by curing the self-crosslinkable epoxy silicone oil according to claim 1; or obtained by curing the self-crosslinkable epoxy silicone oil according to claim 1 mixed with other reagents.

9. The method for preparing the organosilicon material according to claim 8, comprising the steps of curing the self-crosslinkable epoxy silicone oil according to claim 1 to obtain the organosilicon material; or mixing the self-crosslinkable epoxy silicone oil according to claim 1 with other reagents and curing them to obtain the organosilicon material.

10. The method for preparing the organosilicon material according to claim 9, characterized in that: During curing, the heating temperature is 120 to 180°C and the curing time is 30 minutes to 5 hours.

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