Self-crosslinking epoxy silicone oil as well as preparation method and application thereof

Abstract

The invention discloses self-crosslinking epoxy silicone oil as well as a preparation method and application thereof. The self-crosslinking epoxy silicone oil is side epoxy silicone oil with terminal acylamino. The preparation method comprises the following steps: by taking a dimethyl cyclosiloxane monomer, tetramethylcyclotetrasiloxane and an amino double-end socket as raw materials, firstly synthesizing terminal primary amino side hydrogen silicone oil through ring-opening polymerization; amidating amino at the tail end of the silicone oil; then a side epoxy group is introduced through a side hydrogen hydrosilylation reaction, and the end group of the obtained epoxy silicone oil is an amide group which does not react with the side epoxy group at room temperature and lower temperature, so that the epoxy silicone oil can be reprocessed and stably stored; the terminal group amide group can be subjected to addition reaction with the epoxy group under the condition of high temperature, and the organosilicon material belongs to a high-temperature self-crosslinking type organosilicon material and has the characteristic of single-component high-temperature curing. The epoxy silicone oil disclosed by the invention can be applied as a single-component high-temperature curing type adhesive or a resin matrix, the reaction conditions adopted for preparation are mild, the raw materials are all industrial products, bulk, cheap and easily available, the preparation process is simple and convenient, and the epoxy silicone oil is suitable for industrial production.

Description

Technical Field

[0001] The 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, and belongs to the field of organosilicon preparation and organosilicon material application. Background Art

[0002] As we all know, single-component organic silicone is wet-cured. The alkoxy silicon contained in the system is hydrolyzed with trace water in the air to form silanols, and the silanols undergo dehydration condensation to cure. However, the curing process depends on the water content in the air and is uncontrollable. In addition, during the curing process, the byproduct alcohols generated by the hydrolysis of alkoxy groups remain in the system or evaporate into the environment, causing environmental problems that cannot be ignored. Although decarboxylation-type organic silicone adhesives cure quickly, they produce a pungent odor caused by organic carboxylic acid byproducts during the curing process.

[0003] Starting from silicone oil containing epoxy groups, adding primary amine or secondary amine crosslinking agents can react with epoxy groups. This process does not release small molecular byproducts, similar to epoxy resin curing. When tertiary amine substances are added, tertiary amines cannot add to epoxy groups, but tertiary amines can catalyze the ring-opening homopolymerization of epoxy groups according to the process of ionic polymerization. This is because the outer layer of the N atom of the tertiary amine has a pair of unshared electron pairs, which has nucleophilic properties and is a proton acceptor. The electron-pushing effect of the alkyl group in the tertiary amine makes it very electronegative. It is easy to attack the Cδ+ atom on the epoxy group to form negative oxygen ions, which can continue to catalyze the ring-opening reaction of other epoxy groups to make the molecular chain grow or crosslink. However, this process requires the addition of ammonia (or amine) substances as external crosslinking agents or curing catalysts in the curing formula before use. Summary of the invention

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

[0005] The technical solution for achieving the purpose of the present invention is: A self-crosslinkable epoxy silicone oil, which is an epoxy silicone oil with a terminal amide group, and the specific structure is as follows:

[0006] 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.

[0007] The present invention discloses a method for preparing the self-crosslinkable epoxy silicone oil, comprising the following steps: (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.

[0008] In the present invention, the dimethylcyclosiloxane monomer is one of octamethylcyclotetrasiloxane or mixed dimethylcyclosiloxane (DMC); the amino double head is 1,3-bis(aminopropyl)tetramethyldisiloxane; the weight ratio of the dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and the amino double head is 800:1-100:1-100.

[0009] 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 terminal amino side hydrogen silicone oil, triethylamine, and acyl chloride is 800:2-50:5-200. Further, the amidation is carried out in a solvent, and the solvent is any one of toluene and xylene; the acyl chloride is any one of acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, octanoyl chloride, lauroyl chloride, and octadecanoyl chloride. In the terminal amidation, the temperature is 0-25°C when the acyl chloride is added dropwise, and the temperature rises to room temperature naturally after the addition is completed, 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 terminal amide side hydrogen silicone oil; wherein, anhydrous sodium sulfate or anhydrous magnesium sulfate is used for drying.

[0010] 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 to 1000: 1 to 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.

[0011] 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.

[0012] The invention discloses application of the self-crosslinkable epoxy silicone oil in preparing organic silicon materials.

[0013] The present invention discloses an organosilicon material, which is obtained by curing the above-mentioned self-crosslinkable epoxy silicone oil; or by curing the above-mentioned self-crosslinkable epoxy silicone oil by mixing with other reagents. The above-mentioned self-crosslinkable epoxy silicone oil is heated and self-crosslinked to obtain the organosilicon material; or the above-mentioned self-crosslinkable epoxy silicone oil is mixed with other reagents to obtain the organosilicon material. Preferably, during curing, the heating temperature is 120 to 180°C and the time is 30 minutes to 5 hours.

[0014] The invention uses dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double cap as raw materials, and prepares 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 produce a silylation reaction to introduce an epoxy group into the side chain of the silicone oil, so as to produce a self-crosslinking epoxy silicone oil, which can be stored for more than 6 months without changing its nature under room temperature conditions, and is cured and cross-linked if heated to a high temperature, so as to be a high-temperature self-crosslinking epoxy silicone oil material.

[0015] The specific steps are: (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:

[0016] Among them, 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; y = an integer of 1 to 200, preferably 10 to 150, more preferably 30 to 100.

[0017] (2) Terminal 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 for reaction. 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:

[0018] (3) Hydrosilylation: In a reactor, the above-mentioned terminal amide side hydrogen silicone oil undergoes a hydrosilylation reaction with allyl glycidyl ether to obtain a terminal amide epoxy silicone oil; the hydrosilylation reaction formula is as follows:

[0019] 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, and more preferably 100 to 300; y = an integer of 1 to 200, preferably 10 to 150, and more preferably 30 to 100.

[0020] (4) Curing: Heat the silicone oil at high temperature for a certain period of time to cross-link and cure the silicone oil.

[0021] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1. The amide-terminated epoxy silicone oil disclosed in the present invention combines amide and epoxy groups on the same macromolecular chain. The two will not react at low temperatures and are stable under room temperature conditions; but after being heated to high temperatures, they can undergo addition and cross-linking and curing. Therefore, it is suitable for high-temperature one-component silicone adhesives or adhesives.

[0022] 2. The epoxy silicone oil disclosed in the present invention can control the crosslinking density formed by high temperature curing by adjusting the content of pendant epoxy groups in its molecular structure, and the crosslinking density can also be regulated by the molecular weight of the epoxy silicone oil. Unlike conventional epoxy silicone oils that add amine crosslinkers, the crosslinking structure formed by the addition reaction is not affected by the amount of crosslinking agents in the formula (such as the addition of ammonia or amine).

[0023] 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

[0024] 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.

[0025] Figure 3 and Figure 4 This is the hydrogen nuclear magnetic spectrum of the terminal lauramide pendant hydrogen silicone oil and the terminal lauramide epoxy silicone oil prepared in Example 2 of the present invention.

[0026] Figure 5 and Figure 6 These are optical photographs of epoxy silicone oil high-temperature cross-linked films prepared in Example 1 and Example 2 of the present invention. DETAILED DESCRIPTION

[0027] The preparation process of the self-crosslinkable epoxy silicone oil of the present invention comprises: (1) Ring-opening polymerization: Using dimethylcyclosiloxane monomer, tetramethylcyclotetrasiloxane and amino double-capped end as raw materials, terminal primary amino side hydrogen silicone oil is prepared by ring-opening polymerization; (2) Terminal amidation: dissolving the terminal primary amino side hydrogen silicone oil in a solvent, adding acyl chloride to amidate the terminal amino group, and then post-treating to obtain the terminal amide side hydrogen silicone oil; (3) Hydrosilylation: Further hydrosilylation reaction is carried out with allyl glycidol via the side group silicon-hydrogen bond to introduce epoxy groups into the side chains of the silicone oil, thereby obtaining the self-crosslinkable epoxy silicone oil, which is a terminal amide epoxy silicone oil; (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.

[0028] Preferably, in the preparation step (2) of terminal amidation, the solvent used is any one of toluene or xylene; the acid 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): acid chloride is 800: 100-800: 2-50: 5-200. The temperature is 0-25°C when the acid chloride is added dropwise. After the addition is completed, the reaction solution is allowed to naturally rise to room temperature and react for 1-24 hours.

[0029] 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 a desiccant is added for drying; the desiccant is any one of anhydrous sodium sulfate or anhydrous magnesium sulfate. Preferably, during post-treatment, the reaction solution: deionized water each time: desiccant (weight) = 10: 1~10: 0.1~1.

[0030] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The raw materials and reagents used are all existing products, and the specific preparation operations and performance tests are all conventional techniques. Embodiment 1

[0031] (1) Ring-opening polymerization: A 2L four-necked reaction flask was equipped with an electric heating jacket, 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 colorless transparent product, which was terminal amino side hydrogen silicone oil; (2) Terminal acetylamide: 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 for 30 minutes. The reaction was continued by stirring, and the cooling bath was removed to allow the reaction solution to naturally rise to room temperature. The reaction was carried out for a total of 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 with water, 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 2L single-necked flask. The solvent was evaporated under magnetic stirring at 100±5°C and 40 mmHg vacuum conditions and the solvent was removed for 2 hours to obtain 745.1 g of colorless and transparent terminal acetylamide 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 is that there are only two amide groups at the ends of the polymer chain, their concentration is low, and NH is active and easily exchanged by deuterium atoms.

[0032] (3) Hydrosilylation: A 2L four-necked reaction flask was equipped with an electric heating jacket, a reflux condenser, a thermometer and a mechanical stirrer. Under nitrogen protection, 705.0 g of the above-mentioned terminal acetamide side hydrogen silicone oil was added in sequence, and 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. Under stirring, 51.3 g of allyl glycidyl ether was added dropwise through a dropping funnel. The addition was completed in about 1 hour, and the reaction was kept warm for 3 hours after the addition was completed. 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 number average molecular weight (Mn) was measured to be 15190, and the epoxy value was 3.86mmol / g. 9.995g of the product silicone oil was dried at 105℃ for 2h, and the residual mass was weighed to be 9.961g. The volatile matter of the sample was calculated to be 3.4%.

[0033] The chemical structure of the product is:

[0034] After the prepared epoxy silicone oil was stored at room temperature for 6 months, the tested number average molecular weight was 15210 and the epoxy value was 3.85 mmol / g, indicating that the product did not denature after long-term storage.

[0035] (4) High temperature heating curing: Take 10.0g of the product silicone oil and spread it on a 10cm diameter surface dish. 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 10cm diameter surface dish. Add 0.01g of potassium hydroxide dissolved in 0.5g of isopropanol. After manual stirring, apply the film and dry at 155℃ for 30min to obtain a slightly white elastic silicone film ( Figure 5 ), the film breaking elongation was measured to be 320%. Embodiment 2

[0036] (1) The preparation of terminal amino side hydrogen silicone oil by ring-opening polymerization is the same as in Example 1.

[0037] (2) Terminal lauryl amidation: The above-mentioned terminal amino side hydrogen silicone oil was transferred to a 2L four-necked reaction bottle, 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 for a total of 5 hours. The reaction solution was then washed with water 220g × 5 times. After washing with water, 20g 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 2L single-necked flask. The solvent was evaporated and degassed 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 H 3); 0.19-0.06 (Si-C H3)ppm.

[0038] (3) Hydrosilylation: A 2 L four-necked reaction flask was equipped with an electric heating jacket, a reflux condenser, a thermometer and a mechanical stirrer. Under nitrogen protection, 701.0 g of the above-mentioned terminal lauramide side hydrogen silicone oil was added in sequence, and 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. Under stirring, 53.8 g of allyl glycidyl ether was added dropwise through a dropping funnel. The addition was completed in about 1 hour, and the reaction was kept warm for 3 hours after the addition was completed. After stopping the reaction, the reaction was cooled to obtain 743.7 g of a slightly yellow transparent terminal lauramide 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 number average molecular weight (Mn) of the product was measured to be 15660, and the epoxy value was 3.81mmol / g. 10.002g of the product silicone oil was taken and dried at 105℃ for 2h, and the residual mass was weighed to be 9.977g. The volatile matter of the sample was calculated to be 2.5%.

[0039] The chemical structure of the product is:

[0040] 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.

[0041] (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%. Embodiment 3

[0042] (1) Ring-opening polymerization: A 2L four-necked reaction flask was equipped with an electric heating jacket, reflux condenser, thermometer and mechanical stirring. 927.0g of commercially available industrial-grade mixed cyclosiloxane DMC, 30.0g of tetramethylcyclotetrasiloxane and 12.5g of aminopropyl double-capped were added, and 0.9g of tetramethylhydroxylamine was added at 90°C. After keeping the temperature for 5h, the reaction was stopped and the temperature was lowered to obtain 843.5g of colorless transparent product, which was terminal aminopropyl side hydrogen silicone oil.

[0043] (2) Terminal amidation: The above-mentioned terminal amino side hydrogen silicone oil was transferred to a 2L four-necked reaction bottle, 350g toluene and 11.1g triethylamine (TEA) were added, and after stirring to completely dissolve, 15.1g 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 rise to room temperature, and the reaction was carried out for a total of 5 hours; then the reaction solution was washed with water 200g×4 times, and the oil layer after washing was added with 20g anhydrous sodium sulfate and dried for 2 hours, and the desiccant was filtered out, and the filtrate was transferred to a 2L single-necked flask, and the solvent was evaporated and degassed for 2 hours under magnetic stirring at 100±5°C and 40mmHg vacuum conditions to obtain 778.5g of colorless and transparent terminal acetamide side hydrogen silicone oil, with a yield of 91.0%.

[0044] (3) Hydrosilylation: A 2L four-necked reaction flask was equipped with an electric heating jacket, a reflux condenser, a thermometer and a mechanical stirrer. Under nitrogen protection, 703.0 g of the above-mentioned terminal acetamide side hydrogen silicone oil was added in sequence, and 0.7 g of a commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70°C. Under stirring, 42.2 g of allyl glycidyl ether was added dropwise through a dropping funnel. The addition was completed in about 1 hour, and the reaction was kept warm for 3 hours after the addition was completed. After the reaction was stopped, the reaction 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. After taking 10.003 g of the product silicone oil and drying it at 105°C for 2 hours, the residual mass was weighed to be 9.970 g, and the volatile matter of the sample was calculated to be 3.3%.

[0045] The chemical structure of the product is: (4) High temperature heating curing: Take 10.0g of the product silicone oil and spread it in a 10cm diameter watch glass. 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 10.8g of the product silicone oil and spread it in a 10cm diameter watch glass. Add a solution prepared by dissolving 0.01g of potassium hydroxide in 0.5g of isopropanol. After manually stirring, dry it at 125℃ for 1h to obtain a slightly yellow soft elastic film.

[0046] Comparative Example 1 (1) Ring-opening polymerization: A 2L four-necked reaction flask was equipped with an electric heating jacket, 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 were added, 1.0g of tetramethylhydroxylamine was added at 90°C, the reaction was kept warm for 5h, and then 0.8g of acetic acid was added for neutralization reaction for 1h, and filtered to obtain 851.1g of colorless transparent filtrate, which was terminal aminopropyl pendant hydrogen silicone oil, direct hydrosilylation.

[0047] (2) Silicone hydroaddition: 705 g of terminal amino side hydrogen silicone oil was transferred to a 2L four-necked reaction bottle equipped with an electric heating jacket, reflux condenser, thermometer and mechanical stirring. Under nitrogen protection, 0.7 g of commercially available platinum catalyst (isopropanol type) with a platinum content of 5000 ppm was added at 70 ° C, and 51.5 g of allyl glycidyl ether was added dropwise through a dropping funnel under stirring. After the addition was completed, the reaction was kept warm for 3 h. After the reaction was stopped, it 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 shows that while the unsaturated bonds in glycidyl allyl ether reacted with the silicon hydroaddition group, the epoxy group also underwent a ring-opening addition with the primary amino group at the end of the silicone oil, resulting in cross-linking and gelation of the product.

[0048] The prior art believes that the same polymer chain cannot contain both epoxy groups and primary amino groups, because the primary amino group has strong alkalinity and can also undergo addition reaction with the epoxy group at room temperature or even below 0°C. The present invention is directed to the regulation of the molecular structure of silicone oil, and discloses a side chain epoxy silicone oil with a terminal amide group. Since the electron-withdrawing effect of -C=O in the amide group affects the alkalinity of -NH-, the activity of the terminal amide group is much smaller than that of the primary amine and the secondary amine, and the reaction between the epoxy group and the amide is difficult to occur at room temperature. For example, acetamide and epoxy groups react only at 150°C. That is, the present invention reduces the activity of the primary amine group by amidation, thereby concentrating the epoxy group and the amide group on the same polysiloxane macromolecule. The terminal amide group and the side chain epoxy group are difficult to react at room temperature and low temperature, but can produce a ring-opening addition reaction at high temperature, thereby forming 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 cap as raw materials, preparing terminal primary amino side hydrogen silicone oil through 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-treating to obtain the 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 side chain of the silicone oil. (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 = 1 to 200.

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

4. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 2, characterized in that: The amidation reagent includes 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.

5. The method for preparing the self-crosslinkable epoxy silicone oil according to claim 2, characterized in that: 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, characterized in that: The ring-opening polymerization temperature is 50-110° C., and the time is 1-24 hours; the amidation reaction time is 1-24 hours; 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 by mixing with other reagents.

9. The method for preparing the organosilicon material according to claim 8, comprising the following steps: 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 time is 30 minutes to 5 hours.

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