A (meth)acryloyloxy-containing silane coupling agent, a preparation method and application thereof

Abstract

The application belongs to the technical field of silane coupling agents, and particularly relates to a (meth) acryloxy-containing silane coupling agent and a preparation method and application thereof. First, the (meth) acryloxyalkoxysilane coupling agent is reacted with a chlorinating agent under the action of a catalyst to remove low, a solvent is added, and filtration is performed to obtain a (meth) acryloxy-containing chlorosilane; then the (meth) acryloxy-containing chlorosilane is reacted with an organic small molecule compound under the action of an auxiliary, and after filtration or neutralization and filtration, distillation is performed to obtain the product. The preparation method provided by the application has the advantages of easy availability of raw materials, low cost, and mild conditions, breaks the limitation of the structure of the reaction substrate required for the synthesis of the (meth) acryloxy-containing silane coupling agent on the nucleophilic substitution reaction and the silicon-hydrogen addition reaction, and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of silane coupling agent technology, specifically relating to a silane coupling agent containing (meth)acryloyloxy group, its preparation method, and its application. Background Technology

[0002] γ-Methacryloxypropyltrimethoxysilane, containing both acryloyloxy and siloxy functional groups, is widely used in filler surface treatment and resin composite modification. However, its use is limited by the poor environmental impact of methanol release during hydrolysis. Retaining acryloyloxy functional groups while enriching the types of silicon functional groups in the silane molecule chain can expand its applications. For example, silanes with siloxyethoxy silicon functional groups have low VOCs after hydrolysis, making them more environmentally friendly; silanes with silacetoxy silicon functional groups are liquid at room temperature and can replace easily crystallizing methylacetoxysilane crosslinking agents, improving crosslinking activity; silanes with silamido silicon functional groups are highly reactive electron-donating silanes, providing good bonding properties; and silanes with silane-sulfur bonds can improve processing performance in rubber and other processing applications.

[0003] Silane coupling agents containing (meth)acryloyloxy groups are mostly prepared by nucleophilic substitution reaction of sodium salt with chloroalkylsilane or hydrosilylation reaction of (meth)acrylate with hydrogen-containing silane. The former is only applicable to chloroalkoxysilanes. After preparing chloroalkylsilanes containing siloxyethoxy, silacetoxy, silicon-nitrogen bonds, and silicon-sulfur bonds through the substitution reaction of Si-Cl bonds in chloroalkylchlorosilanes, it is difficult to react with sodium (potassium) salts of (meth)acrylate to prepare silane coupling agents containing both (meth)acryloyloxy carbon functional groups and Si-O silicon functional groups. The latter is only commonly found among hydrosilanes, namely methoxysilanes and ethoxysilanes. Directly reacting hydrochlorosilanes with ethylene glycol monomethyl ether, acetic acid, organic amines, ketoximes, etc., cannot yield hydrosilanes containing siloxyethoxy, silacetoxy, silicon-nitrogen bonds, etc. At the same time, allyl methacrylate has many addition sites with hydroalkoxysilanes and hydrochlorosilanes, resulting in many impurities, which is not advisable.

[0004] Existing technologies lack a reliable method for the simple, universal, and efficient synthesis of silane coupling agents possessing both (meth)acryloyloxy carbon functional groups and specific silicon functional groups. Therefore, there is an urgent need in the field to develop a new synthetic strategy to overcome the technical bottlenecks of current methods in terms of substrate scope, functional group compatibility, and product purity. Summary of the Invention

[0005] Based on this, the purpose of this invention is to provide a method for preparing a silane coupling agent containing (meth)acryloyloxy group. This method uses readily available raw materials, is low in cost, and operates under mild conditions. It breaks the limitations imposed by nucleophilic substitution and hydrosilylation reactions on the required substrate structure for the synthesis of (meth)acryloyloxy group silane coupling agents, and is suitable for industrial production.

[0006] This invention also provides a silane coupling agent containing (meth)acryloyloxy and its application. The coupling agent contains both acryloyloxy carbon functional groups and silicon functional groups such as silacetoxy and silisopropoxy, and can be widely used in filler surface treatment, resin composite material modification and other fields.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for preparing a silane coupling agent containing (meth)acryloyloxy group, comprising the following steps: S1, at 25±5℃ under an inert atmosphere, the (meth)acryloyloxyalkoxysilane coupling agent and the catalyst are first mixed to obtain a mixture, and then the chlorinating agent is added to the mixture for heating and reflux reaction. After the reaction is completed, the low-boiling substances are removed, and after solvent addition, filtration and distillation are performed to obtain a chlorosilane filtrate containing (meth)acryloyloxy. S2, add the auxiliary agent and small organic molecule compound to the filtrate described in S1 and heat the reaction. After the reaction is completed, remove the low-boiling substances, filter or neutralize and filter, and distill to obtain the silane coupling agent containing (meth)acryloyloxy group.

[0008] Further, the amount of catalyst used in S1 is 1.5~5% of the mass of the (meth)acryloyloxyalkoxysilane coupling agent; the molar ratio of alkoxy group to chlorinating agent in the (meth)acryloyloxyalkoxysilane coupling agent is 1:(1~1.2); preferably, the chlorinating agent is added dropwise at a rate of 90~100 g / h.

[0009] Furthermore, in S1, the heating reflux reaction temperature is 80±1℃, the time is 1.5~2.5h, the pressure for removing low-boiling substances is -0.03~-0.01MPa, until the system is free of bubbles, in order to remove highly volatile byproducts such as low-boiling-point chloromethane and sulfur dioxide; the solvent filtration temperature is below 50℃, and the amount of solvent used is 40~100% of the mass of the (meth)acryloyloxyalkoxysilane coupling agent; the distillation temperature is 90~100℃, and the pressure is -0.04~-0.03MPa, in order to remove the raw material chlorinating agent, solvent, catalyst, etc.

[0010] Further, the (meth)acryloyloxyalkoxysilane coupling agent in S1 includes γ-(meth)acryloyloxypropyltrialkoxysilane, γ-(meth)acryloyloxypropylmethyldialkoxysilane, or γ-(meth)acryloyloxypropyldimethylalkoxysilane; the alkoxy group in the (meth)acryloyloxyalkoxysilane coupling agent includes methoxy groups.

[0011] Further, the catalyst in S1 includes a Lewis acid, an organic base, or a metal salt; the Lewis acid includes aluminum trichloride, ferric trichloride, tin tetrachloride, magnesium chloride, or bismuth chloride; the organic base includes N,N-dimethylformamide, triethylamine, pyridine, or pyrrole; and the metal salt includes KI or NaI, preferably N,N-dimethylformamide.

[0012] Furthermore, the chlorinating agent mentioned in S1 includes thionyl chloride, phosphorus trichloride, or acetyl chloride, preferably thionyl chloride.

[0013] Furthermore, the solvent mentioned in S1 includes a non-polar solvent, such as cyclohexane, n-hexane, or petroleum ether. Filtration with a non-polar solvent can remove salts generated during the catalytic reaction, ensuring the quality of the target product.

[0014] Further, the amount of the auxiliary agent in S2 is 200~1000 ppm by mass of the (meth)acryloyloxysilane coupling agent, and the molar ratio of the organic small molecule compound to the alkoxy group in (meth)acryloyloxysilane is (1.1~1.3):1; preferably, the organic small molecule compound is added by dripping at a rate of 80~90 g / h.

[0015] Further, the heating reaction temperature in S2 is 65±1℃, and the pressure for removing low-boiling substances is -0.04MPa to -0.01MPa, until no bubbles are present in the system, in order to remove low-boiling-point byproducts such as hydrogen chloride and acetyl chloride; the filtration conditions are to filter in the absence of air and water vapor, and the neutralizing agent used in the neutralization includes sodium acetate or an organic base, wherein the organic base includes triethylamine, tripropylamine, pyridine, or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or hexamethyldisilazane, preferably triethylamine; the distillation temperature is 140~190℃, and the pressure is -0.09~-0.06MPa.

[0016] Further, the adjuvants described in S2 include 2,6-di-tert-butyl-p-cresol (BHT), 2,5-di-tert-butylhydroquinone, 3-tert-butylcatechol, bis(3,5-tri-tert-butyl-4-hydroxyphenyl) sulfide, cuprous chloride, ferric chloride, trioctyl ester, or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxo radical, preferably 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxo radical.

[0017] Furthermore, the small organic molecule compound mentioned in S2 is a compound that can react with silicon chloride bonds, including ethylene glycol monomethyl ether, n-propanol, isopropanol, n-butanol, glacial acetic acid, acetic anhydride, ketoxime, or acetone.

[0018] More preferably, when the organic small molecule compound is an ether or alcohol such as ethylene glycol monomethyl ether, n-propanol, isopropanol, n-butanol, ketoxime, glacial acetic acid, or acetic anhydride, some of the low-boiling-point impurities by-products can be removed by negative pressure, reducing the amount of neutralizing agents such as sodium acetate and organic bases required for neutralization; if the pH of the system is close to neutral after removal, neutralization is not necessary, i.e., no neutralizing agent needs to be added.

[0019] The present invention further provides a silane coupling agent containing (meth)acryloyloxy group, which is prepared by the above-described method for preparing a silane coupling agent containing (meth)acryloyloxy group.

[0020] Furthermore, the silane coupling agent containing (meth)acryloyloxy group contains both acryloyloxy carbon functional group and silicon functional group.

[0021] This invention further provides the application of (meth)acryloyloxy-containing silane coupling agents in the fields of filler surface treatment or resin composite material modification. In the process of filler surface treatment or resin composite material modification, due to the rich variety of silicon functional groups in (meth)acryloyloxy-containing silane coupling agents, different silicon functional groups can endow them with excellent properties, such as: lower hydrolysis VOCs, making the process more environmentally friendly; improved crosslinking activity; good adhesion properties; or enhanced material processing properties, etc.

[0022] The beneficial effects of this invention are: This invention first uses common (meth)acryloyloxyalkoxysilane coupling agents and chlorinating agents as raw materials to convert (meth)acryloyloxyalkoxysilane coupling agents into (meth)acryloyloxychlorosilanes. Then, with the help of an auxiliary agent, various silane coupling agents containing both acryloyloxy carbon functional groups and Si-O or Si-N silicon functional groups are prepared through Si-Cl reactivity. This preparation method uses readily available raw materials, is low in cost, and operates under mild conditions. It breaks the limitations imposed by nucleophilic substitution and hydrosilylation reactions on the required substrate structure for the synthesis of (meth)acryloyloxysilane coupling agents, making it suitable for industrial production. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. All mentioned embodiments are implemented under the premise of the technical solutions of the present invention, and detailed implementation processes are given. However, it should be stated that the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the test methods used in the following experimental examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available reagents and materials; the room temperature or room temperature, unless otherwise specified, is 25±5℃. In the present invention, unless otherwise specified, "%" refers to mass percentage. The chloride ion test method refers to HG / T5154-2017, and the yield is calculated based on the absence of excessive (meth)acryloyloxypropyltrimethoxysilane.

[0024] Example 1

[0025] The preparation of a silane coupling agent containing (meth)acryloyloxy group is as follows: (1) Preparation of (meth)acryloyloxychlorosilane: Under nitrogen protection and stirring, 124.2 g of methacryloxypropyltrimethoxysilane and 3.1 g of N,N-dimethylformamide were mixed evenly. 192.7 g of thionyl chloride was added dropwise at room temperature over 2 hours. The mixture was then heated to approximately 80 °C and refluxed for 2 hours. After reflux, low-boiling substances such as chloromethane and sulfur dioxide were removed at -0.03 to -0.01 MPa until no obvious bubbles were observed. The gas phase test showed that the content of methacryloxypropyltrimethoxysilane was 0.37%. The mixture was then cooled to below 50 °C, and 62 g of cyclohexane solvent was added and stirred for 10-15 minutes before filtration.

[0026] (2) Preparation of silane coupling agents containing (meth)acryloyloxy groups: Add 0.05 g of 2,6-di-tert-butyl-p-cresol to the filtrate, heat to about 65 °C, and add 199.1 g of acetic anhydride dropwise over 2 hours and 20 minutes. Remove byproduct acetyl chloride and solvent cyclohexane at -0.04 MPa to -0.03 MPa until no bubbles are present. Distill at about 80 °C and at -0.05 to -0.04 MPa to recover excess acetic anhydride. Slowly raise the temperature and increase the vacuum to -0.08 to -0.07 MPa and distill at 150 to 152 °C to obtain 145.6 g of a colorless and transparent product with a purity of 97.2% and a chloride ion concentration of 43 ppm, yielding 87.6%.

[0027] The 1H NMR spectrum data of the product obtained in this embodiment are as follows: 1 H-NMR (400 MHz, CDCl3, δ): 1.17-1.22ppm (2H, Si CH2 CH2CH2O), 1.82ppm (2H,SiCH2) CH2 CH2O), 1.91ppm (3H, CH2=C) (CH3) COO-),2.04-2.11ppm (9H,Si(OCO CH3)3 ),4.08-4.11ppm (2H, SiCH2CH2 CH2 O), 5.53ppm and 6.08ppm (2H, CH2 =C(CH3)COO-).

[0028] The 1H NMR data showed that the product obtained was methacryloyloxypropyltriacetoxysilane.

[0029] Example 2

[0030] The preparation of a silane coupling agent containing (meth)acryloyloxy group is as follows: (1) Preparation of (meth)acryloyloxychlorosilane: Under nitrogen protection and stirring, 116.2 g of methacryloxypropylmethyldimethoxysilane and 3.5 g of pyridine were mixed evenly, and 214.1 g of thionyl chloride was added dropwise at room temperature over 2 hours and 20 minutes. The mixture was then heated to about 80°C and refluxed for 2 hours. After reflux, the pressure was reduced to -0.03 to -0.01 MPa until no obvious bubbles were observed. The mixture was then cooled to below 50°C, and 60 g of n-hexane solvent was added and stirred for 10 to 15 minutes before filtration.

[0031] (2) Preparation of silane coupling agents containing (meth)acryloyloxy groups: Add 0.07 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxo radical to the filtrate, heat to about 65 °C, and add 108.1 g of glacial acetic acid dropwise over 1 hour and 15 minutes. Remove low-boiling byproduct hydrogen chloride at -0.02 MPa to -0.01 MPa until no bubbles are produced. Neutralize with sodium acetate to pH 5.53, filter, and distill at -0.04 to -0.03 MPa to recover excess acetic acid. Slowly raise the temperature and increase the vacuum to -0.08 to -0.07 MPa at 138 to 140 °C to distill, yielding 114.2 g of a colorless, transparent product with 97.4% purity and 31 ppm chloride ions, with a yield of 79.2%.

[0032] The 1H NMR spectrum data of the product obtained in this embodiment are as follows: 1 H-NMR (400 MHz, CDCl3, δ): 0.12ppm(3H,Si-CH 3 ), 1.16-1.20ppm (2H, Si) CH2 CH2CH2O), 1.73ppm (2H,SiCH2) CH2 CH2O) 1.93ppm (3H, CH2=C) (CH3) COO-), 2.05-2.10ppm(6H,Si(OCO) CH3)2 ), 4.1ppm (2H, SiCH2CH2) CH2 O), 5.56ppm and 6.1ppm (2H, CH2 =C(CH3)COO-).

[0033] The 1H NMR data showed that the product obtained was methacryloyloxypropylmethyldiacetoxysilane.

[0034] Example 3

[0035] The difference between this embodiment and Example 1 is that the 199.1g acetic anhydride in step (2) was replaced with 136.4g ethylene glycol monomethyl ether, resulting in 158.5g of a colorless, transparent liquid with 97.6% chloride ion concentration and 8.9ppm, yielding a yield of 83.3%. The 1H NMR spectrum of the product obtained in this embodiment is as follows: 1 H-NMR (400 MHz, CDCl3, δ): 1.13-1.17 ppm (2H, Si) CH2 CH2CH2O), 1.83ppm (2H, SiCH2) CH2 CH2O), 1.98ppm (3H, CH2=C) (CH3) COO-),3.3-3.4ppm(9H,Si(OCH2CH2O CH3)3 ), 3.52-3.65ppm(6H,Si(OCH2 CH2 OCH3)3),3.74-3.89ppm(6H,Si(O CH2 CH2OCH3)3),4.16ppm (2H, SiCH2CH2 CH2 O), 5.51ppm and 6.07ppm (2H, CH2 =C(CH3)COO-).

[0036] The 1H NMR data showed that the product obtained was methacryloyloxypropyltris(2-methoxyethoxy)silane.

[0037] Example 4

[0038] The difference between this embodiment and Example 1 is that 199.1g of acetic anhydride in step (2) was replaced with 117g of isopropanol, resulting in 131.6g of a colorless, transparent liquid with 98.3% chloride ion concentration and 6.2ppm, yielding 81.6%. The 1H NMR spectrum of the product obtained in this embodiment is as follows: 1 H-NMR (400 MHz, CDCl3, δ): 0.58ppm(2H,Si CH2 CH2CH2O), 1.21ppm((9H,Si(OCH) CH3)3 ), 1.7ppm (2H,SiCH2) CH2 CH2O), 1.95ppm (3H, CH2=C) (CH3) COO-), 3.82ppm(3H,Si(O) CH CH3)3), 4.1ppm (2H,SiCH2CH2) CH2 O), 5.53ppm and 6.1ppm (2H, CH2 =C(CH3)COO-).

[0039] The 1H NMR data showed that the product obtained was methacryloyloxypropyltris(isopropoxy)silane.

[0040] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a silane coupling agent containing (meth)acryloyloxy group, characterized in that, Includes the following steps: S1, at 25±5℃ under an inert atmosphere, the (meth)acryloyloxyalkoxysilane coupling agent and the catalyst are first mixed to obtain a mixture, and then the chlorinating agent is added to the mixture for heating and reflux reaction. After the reaction is completed, the low-boiling substances are removed, and after solvent addition, filtration and distillation, a chlorosilane filtrate containing (meth)acryloyloxy is obtained. S2, add the auxiliary agent and small organic molecule compound to the filtrate described in S1 and heat the reaction. After the reaction is completed, remove the low-boiling substances, and after filtration or neutralization, filter and distill to obtain the silane coupling agent containing (meth)acryloyloxy group.

2. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The amount of catalyst used in S1 is 1.5 to 5% of the mass of the (meth)acryloyloxyalkoxysilane coupling agent; the molar ratio of alkoxy to chlorinating agent in the (meth)acryloyloxyalkoxysilane coupling agent is 1:(1 to 1.2).

3. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The heating and reflux reaction in S1 is carried out at a temperature of 80±1℃ for 1.5~2.5h, and the pressure for removing low-boiling substances is -0.03~-0.01MPa, until no bubbles are present in the system; the solvent addition and filtration temperature is below 50℃, and the amount of solvent used is 40~100% of the mass of the (meth)acryloyloxyalkoxysilane coupling agent; the distillation temperature is 90~100℃, and the pressure is -0.04~-0.03MPa.

4. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The (meth)acryloyloxyalkoxysilane coupling agent in S1 includes γ-(meth)acryloyloxypropyltrialkoxysilane, γ-(meth)acryloyloxypropylmethyldialkoxysilane, or γ-(meth)acryloyloxypropyldimethylalkoxysilane; the alkoxy group in the (meth)acryloyloxyalkoxysilane coupling agent includes methoxy; the catalyst includes a Lewis acid, an organic base, or a metal salt; the Lewis acid includes aluminum trichloride, ferric chloride, tin tetrachloride, magnesium chloride, or bismuth chloride; the organic base includes N,N-dimethylformamide, triethylamine, pyridine, or pyrrole; the metal salt includes KI or NaI; the chlorinating agent includes sulfoxide, phosphorus trichloride, or acetyl chloride; the solvent includes a nonpolar solvent, which includes cyclohexane, n-hexane, or petroleum ether.

5. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The amount of the auxiliary agent in S2 is 200~1000 ppm of the mass of the (meth)acryloyloxysilane coupling agent, and the molar ratio of the organic small molecule compound to the alkoxy group in (meth)acryloyloxysilane is (1.1~1.3):

1.

6. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The heating reaction in S2 is carried out at a temperature of 65±1℃, and the pressure for removing low-boiling substances is -0.04MPa to -0.01MPa, until no bubbles are present in the system. The neutralizing agent used in the neutralization includes sodium acetate or an organic base. The distillation temperature is 140 to 190℃, and the pressure is -0.09 to -0.06MPa.

7. The method for preparing the (meth)acryloyloxy silane coupling agent according to claim 1, characterized in that, The adjuvants described in S2 include 2,6-di-tert-butyl-p-cresol, 2,5-di-tert-butylhydroquinone, 3-tert-butylcatechol, bis(3,5-tri-tert-butyl-4-hydroxyphenyl) sulfide, cuprous chloride, ferric chloride, trioctyl ester, or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxo radical; the organic small molecule compounds include ethylene glycol monomethyl ether, n-propanol, isopropanol, n-butanol, glacial acetic acid, acetic anhydride, ketoxime, or acetone.

8. A silane coupling agent containing (meth)acryloyloxy group, characterized in that, It is prepared using the method for preparing (meth)acryloyloxy silane coupling agents according to any one of claims 1 to 7.

9. The silane coupling agent containing (meth)acryloyloxy group according to claim 8, characterized in that, The silane coupling agent containing (meth)acryloyloxy group contains both acryloyloxy carbon functional group and silicon functional group.

10. The application of a silane coupling agent containing (meth)acryloyloxy group as described in claim 8 or 9 in the field of filler surface treatment or resin composite material modification.