A method for preparing an epoxy-modified silicone oil

Abstract

The application provides a preparation method of epoxy-modified silicone oil. The preparation method comprises the following steps: preparing a hydrolysate of 3-[(2,3)-epoxypropoxy]propyl methyl dimethoxysilane, carrying out ring-opening copolymerization reaction of octamethylcyclotetrasiloxane and the aforementioned hydrolysate, finally adding a capping agent to react for a period of time under the conditions of reduced pressure and normal temperature, and then heating to deactivate the catalyst. During the ring-opening copolymerization reaction, a certain amount of dimethylformamide and a catalyst are added, and then a crown ether or the like is added to form a supramolecular complex with the catalyst to accelerate the catalytic reaction process. The epoxy-modified silicone oil prepared by the method has controllable viscosity, is extremely easy to emulsify into transparent microemulsion and has excellent stability, and exhibits good application effect when used as a fabric treatment agent.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon preparation, specifically relating to a method for preparing epoxy-modified silicone oil. Background Technology

[0002] The primary industrial application of epoxy-modified silicone oils is as fabric treatment agents. Treating polyester or polypropylene fibers with epoxy-modified silicone oil and aminopropyltriethoxysilane imparts a near-feather-like smoothness and softness. Additionally, some researchers have proposed using epoxy-modified and amino-modified silicone oils together to create a woolly or Angora goat-like feel. Furthermore, treating polyester sewing thread with epoxy-modified silicone oil can improve sewing speed and colorfastness. Due to the high reactivity of epoxy groups, epoxy-modified silicone oils can also be used as reactive intermediates in the synthesis of other silicone oils, such as quaternary ammonium salt-modified silicone oils, or as modifiers for epoxy resins.

[0003] There are two main methods for synthesizing epoxy-modified silicone oils in the existing technology. The first method involves catalytic hydrosilylation of hydrogen-containing silicone oil and unsaturated epoxy compounds. However, this method is not suitable for synthesizing epoxy-modified silicone oils with large molecular weights because the yield of the hydrosilylation reaction is low at higher degrees of polymerization, and the product is difficult to collect. The other method involves introducing epoxy hydrocarbon groups through hydrosilylation at the monomer or oligomeric siloxane stage, followed by equilibrium copolymerization with D4 or polydimethylsiloxane in the presence of an alkaline catalyst. However, the epoxy groups are easily destroyed by ring-opening by acids or bases, resulting in insufficient epoxy content in the final product. Summary of the Invention

[0004] To address the aforementioned problems in existing methods for synthesizing epoxy-modified silicone oils, this invention provides an improved method for preparing epoxy-modified silicone oils. This method effectively solves the problem that epoxy groups are easily destroyed by acid or alkali ring-opening, and can stably prepare epoxy-modified silicone oils with high yield. Furthermore, the epoxy-modified silicone oils prepared by this method have high epoxy content and controllable viscosity.

[0005] The method for preparing epoxy-modified silicone oil according to the present invention includes:

[0006] A hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane was prepared, and the hydrolysate was subjected to a ring-opening copolymerization reaction with octamethylcyclotetrasiloxane and hexamethyldisiloxane as a capping agent. The structural formula of the 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane is as follows: Wherein R is independently selected from methyl and ethyl. In one embodiment of the invention, the 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane is 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane.

[0007] According to the present invention, the preparation of the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane involves hydrolyzing 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane under alkaline conditions, at atmospheric pressure, and at 5-17°C for 0.5-2.5 h. In one embodiment of the present invention, the alkaline conditions are provided by a 0.15 wt% to 0.4 wt% aqueous sodium hydroxide solution. In some embodiments of the present invention, the mass ratio of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to the aqueous sodium hydroxide solution is (0.5-18):1, preferably (2-18):1, more preferably (5-18):1, and even more preferably (9-18):1.

[0008] According to the present invention, the preparation of the hydrolysate further includes dehydrating the hydrolysate under negative pressure, wherein the dehydration treatment substantially removes the free water from the hydrolysate to obtain the final hydrolysate. In one embodiment of the present invention, the negative pressure is -0.99 MPa to -0.95 MPa. Those skilled in the art will understand the meaning of substantially removing free water, which generally refers to the free water content in the substance being ≤1% after dehydration treatment.

[0009] According to the present invention, the reaction system of the ring-opening copolymerization reaction contains a solvent and a catalyst. The solvent is an organic solvent with water-oil two-phase miscibility, such as dimethylformamide, ethyl acetate, etc., and the catalyst is a basic salt of a silanol. From the perspective of environmental friendliness in production, dimethylformamide is more preferred as the solvent. The catalyst can be a basic salt of a silanol, or a mixture of two or more basic salts of silanols. Examples of basic salts of silanols include tetramethylammonium hydroxide silanolate, sodium methylsilanolate, etc.

[0010] According to the present invention, the ring-opening copolymerization reaction is carried out in two stages. The first stage involves the ring-opening copolymerization of the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane with octamethylcyclotetrasiloxane. The second stage involves the addition of the end-capping agent hexamethyldisiloxane, followed by continued ring-opening copolymerization. The reaction is carried out under a negative pressure of -0.99 MPa to -0.95 MPa and at 70-80 °C. The first stage reaction lasts 10-40 mins, and the second stage reaction lasts 1.5-3.5 h.

[0011] According to the present invention, in the ring-opening copolymerization reaction, the mass ratio of the hydrolysate of octamethylcyclotetrasiloxane, 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane and the capping agent is 50-90:5-50:0.1-2.0.

[0012] According to the present invention, in the ring-opening copolymerization reaction, the mass amount of solvent is 10% to 100% of the mass of octamethylcyclotetrasiloxane, for example, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc. In some embodiments of the present invention, the mass amount of solvent is 30% to 60% of the mass of octamethylcyclotetrasiloxane. According to the present invention, to improve the catalytic reactivity, substances that can form supramolecular complexes with the catalyst, such as polyethylene glycol, crown ethers, cryptands, and polyethers, can be added. According to the present invention, the mass ratio of the catalyst to the crown ether (or polyethylene glycol, cryptand, or polyether) is (0.02 to 1):1, preferably (0.05 to 0.1):1.

[0013] According to the present invention, after the ring-opening copolymerization reaction is completed, the temperature is increased to deactivate the catalyst and remove low molecular weight compounds from the reaction system.

[0014] According to the present invention, the method further includes the steps of separating and collecting the oil phase, washing it with water until neutral, and allowing it to stand and cool to obtain epoxy-modified silicone oil.

[0015] In some preferred embodiments of the present invention, the preparation method includes:

[0016] 1) Preparation of hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane: 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane was mixed with 0.15 wt.% to 0.4 wt.% sodium hydroxide aqueous solution in a closed container and stirred at a constant speed. The hydrolysis reaction was carried out under normal pressure and 10 to 15 °C for 0.5 to 2.0 h. Then, the dehydration was carried out under reduced pressure of -0.99 MPa to -0.95 MPa for 0.5 to 2.0 h. After cooling, the mixture was allowed to stand to obtain the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane.

[0017] 2) Ring-opening copolymerization reaction: Octamethylcyclotetrasiloxane is mixed with the hydrolysate obtained in step 1), and dimethylformamide, catalyst and crown ether (or polyethylene glycol, cryptane, polyether) are added. The mixture is first reacted under reduced pressure of -0.99MPa to -0.95MPa and at 70-80℃ for 20-30 mins; then, hexamethyldisiloxane (MM) is added as a capping agent and the reaction is continued for another 2.0-3.0 h; after that, the temperature is raised to 160℃ to deactivate the catalyst and remove low molecular weight compounds from the reaction system for 0.5-2.0 h.

[0018] Optional, further including step 3): separating and collecting the oil phase and washing it with water until neutral, then allowing it to stand and cool to obtain epoxy-modified silicone oil.

[0019] The structural formula of the epoxy-modified silicone oil prepared by this method is as follows:

[0020]

[0021] It is a random copolymer, where x and y are non-zero positive integers. The two structures above are linked and repeated to form units, and the degree of polymerization is represented by n; R1 is...

[0022] This invention first hydrolyzes 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane containing epoxy groups under alkaline, low-temperature reaction conditions. This yields a silanediol-based hydrolysate that can copolymerize with D4, while simultaneously protecting the epoxy groups from ring-opening under alkaline conditions. Secondly, under improved catalytic reaction conditions, the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane undergoes a rapid equilibrium copolymerization reaction with D4 in high yield. The epoxy groups in the resulting epoxy-modified silicone oil are also protected during this reaction process.

[0023] Obviously, this invention solves the problems of low yield in the hydrosilylation reaction synthesis route and easy destruction of epoxy groups in the two conventional synthesis routes of existing epoxy-modified silicone oil preparation technology.

[0024] Furthermore, the epoxy-modified silicone oil prepared by this invention has the characteristic of controllable viscosity. To prepare epoxy-modified silicone oils with different viscosities, it is only necessary to adjust the ratio of the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to D4 during the second reaction step. The epoxy-modified silicone oil prepared by this invention readily emulsifies into a transparent microemulsion and exhibits excellent stability, demonstrating good application performance as a fabric treatment agent.

[0025] The epoxy-modified silicone oil prepared by this invention can also be used to prepare other block-modified silicone oils. For example, the epoxy-modified silicone oil of this invention, polyetheramine, and solvent are mixed, and triethylamine is used as a catalyst to react and prepare modified silicone oil. Because the epoxy-modified silicone oil of this invention has a higher epoxy content than commercially available epoxy-modified silicone oils, the block-modified silicone oil for textiles prepared using it can increase the number of siloxane chain segments, allowing the prepared block-modified silicone oil to have good water dispersibility with only a small amount of emulsifier.

[0026] In this invention, unless otherwise specified, the pressure value is the gauge pressure. Gauge pressure refers to pressure measurement based on atmospheric pressure. Its output signal is the difference between atmospheric pressure and the measured pressure, i.e.: Gauge pressure = Absolute pressure - Standard atmospheric pressure. In the vacuum industry, gauge pressure is represented by a negative number, which refers to the difference between the measured gas pressure and atmospheric pressure, also called negative pressure. For example, -0.99 MPa means that the absolute pressure is standard atmospheric pressure minus 0.99 MPa. Attached Figure Description

[0027] Figure 1 Mid-infrared spectrum of the epoxy-modified silicone oil prepared in Example 1. Detailed Implementation

[0028] The technical solution of the present invention will be further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the scope of the embodiments described below.

[0029] In the embodiments of the present invention, unless otherwise specified, all parts and percentages are units of mass. Unless otherwise specified, the methods for testing product properties such as viscosity in the embodiments are conventional methods in the art.

[0030] Comparative Example

[0031] 50 parts of octamethylcyclotetrasiloxane and 20 parts of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane were mixed, and 20 parts of dimethylformamide and 0.1 parts of tetramethylammonium hydroxide silanolate were added. Then, 0.1 parts of the end-capping agent hexamethyldisiloxane (MM) were added and the mixture was reacted at -0.99 MPa reduced pressure and 70 °C for 2.0 h. After that, the temperature was raised to 160 °C to deactivate the catalyst and remove low molecular weight compounds from the reaction system for 2.0 h. Finally, the oil phase was separated and collected, washed with water until neutral, and allowed to stand and cool to obtain epoxy-modified silicone oil.

[0032] Example 1

[0033] 1) Mix 50 parts of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane with 5 parts of 0.2 wt.% sodium hydroxide aqueous solution in a closed container and carry out hydrolysis reaction at atmospheric pressure and 10 °C for 0.5 h. Then, dehydrate the above reaction system under reduced pressure of -0.99 MPa for 1.0 h, and after cooling and standing, obtain silane hydrolysate.

[0034] 2) Mix 50 parts of octamethylcyclotetrasiloxane with 20 parts of the hydrolysate obtained in step 1), add 20 parts of dimethylformamide and 0.1 parts of tetramethylammonium hydroxide silanolate; then add 2.0 parts of crown ether to form a supramolecular complex with the catalyst to accelerate the catalytic reaction process. First, pre-react at -0.99 MPa reduced pressure and 70 °C for 30 mins; then, add 0.1 parts of the end-capping agent hexamethyldisiloxane (MM) and react at -0.99 MPa reduced pressure and 70 °C for 2.0 h; then, raise the temperature to 160 °C to deactivate the catalyst and remove low molecular weight compounds from the reaction system for 2.0 h; finally, separate and collect the oil phase and wash it with water until neutral, and let it stand and cool to obtain epoxy-modified silicone oil.

[0035] Example 2

[0036] 1) The conditions and material usage in step 1) of this embodiment are the same as those in step 1) of embodiment 1.

[0037] 2) Mix 50 parts of octamethylcyclotetrasiloxane with 50 parts of the hydrolysate obtained in step 1). The other conditions and material amounts in step 2) of this example are the same as in step 2) of Example 1. Finally, separate and collect the oil phase, wash it with water until neutral, and allow it to stand and cool to obtain epoxy-modified silicone oil.

[0038] Example 3

[0039] 1) Mix 90 parts of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane with 5 parts of 0.2 wt.% sodium hydroxide aqueous solution in a closed container. The other conditions in step 1) of this example are the same as those in step 1) of Example 1.

[0040] 2) The conditions and material amounts in step 2) of this embodiment are the same as those in step 2) of Example 1. Finally, the oil phase is separated and collected, washed with water until neutral, and allowed to stand and cool to obtain epoxy-modified silicone oil.

[0041] Example 4

[0042] 1) The conditions and material usage in step 1) of this embodiment are the same as those in step 1) of embodiment 1.

[0043] 2) Mix 50 parts of octamethylcyclotetrasiloxane with 20 parts of the hydrolysate obtained in step 1), add 20 parts of dimethylformamide and 0.1 parts of sodium methylsiloxane; the other conditions and material amounts in step 2) of this example are the same as in step 2) of Example 1. Finally, separate and collect the oil phase and wash it with water until neutral, then let it stand and cool to obtain epoxy-modified silicone oil.

[0044] Example 5

[0045] 1) The conditions and material usage in step 1) of this embodiment are the same as those in step 1) of embodiment 1.

[0046] 2) Mix 50 parts of octamethylcyclotetrasiloxane with 50 parts of the hydrolysate obtained in step 1), add 20 parts of dimethylformamide and 0.1 parts of sodium methylsiloxane; the other conditions and material amounts in step 2) of this example are the same as in step 2) of Example 1. Finally, separate and collect the oil phase and wash it with water until neutral, then let it stand and cool to obtain epoxy-modified silicone oil.

[0047] Example 6

[0048] 1) Mix 90 parts of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane with 5 parts of 0.2 wt.% sodium hydroxide aqueous solution in a closed container. The other conditions in step 1) of this example are the same as those in step 1) of Example 1.

[0049] 2) Mix 50 parts of octamethylcyclotetrasiloxane with 50 parts of the hydrolysate as required by the material, and add 20 parts of dimethylformamide and 0.1 parts of sodium methylsiloxane. The other conditions and material amounts in step 2) of this example are the same as in step 2) of Example 1. Finally, separate and collect the oil phase, wash it with water until neutral, and let it stand and cool to obtain epoxy-modified silicone oil.

[0050] The epoxy-modified silicone oil obtained in the above embodiments and commercially available epoxy-modified silicone oils were subjected to performance tests, including their viscosity and epoxy content. The viscosity was tested according to the capillary method in GB / T 10247-2008, using a Pinton viscometer under constant temperature water bath conditions at 25°C.

[0051] Table 1 compares the performance of epoxy-modified silicone oils in the comparative examples and embodiments with those of commercially available epoxy-modified silicone oils.

[0052]

[0053] As shown in the table above, the epoxy content of the side-chain epoxy-based silicone oil in Comparative Example 1 is significantly lower than that in Examples 1, 3, and 4, which were prepared under the same conditions. Meanwhile, the epoxy content of the side-chain epoxy-based silicone oil prepared by this invention is also higher than that of commercially available epoxy-modified silicone oils. It is evident that the technical approach of this invention achieves the preparation of epoxy-based side-chain branched silicone oils while effectively protecting the epoxy structure.

[0054] The epoxy-modified silicone oil obtained in Example 1 was subjected to mid-infrared scanning, and the results are shown in the appendix. Figure 1 As shown. (From the appendix) Figure 1 As can be seen, in the infrared spectrum of the silicone oil prepared in Example 1, the values ​​in the 1000-1100 cm⁻¹ range are... -1The epoxy group signal at the position is strong, and the prepared modified silicone oil does indeed have epoxy group structures branched on the side.

Claims

1. A method for preparing epoxy-modified silicone oil, characterized in that... include: A hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane was prepared, and the hydrolysate was subjected to a ring-opening copolymerization reaction with octamethylcyclotetrasiloxane and hexamethyldisiloxane as a capping agent. The structural formula of the 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane is as follows: R is independently selected from methyl and ethyl; The preparation of the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane involves hydrolyzing 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane under alkaline conditions, at atmospheric pressure, and at 5-17°C for 0.5-2.5 h. The reaction system of the ring-opening copolymerization reaction contains a solvent and a catalyst. The solvent is an organic solvent with water-oil two-phase mixing characteristics, and the catalyst is a basic salt of silanol. A substance that can form a supramolecular complex with the catalyst is added. The substance is selected from one or more of crown ethers, cryptoethers, and polyethers. The ring-opening copolymerization reaction is carried out in two stages. The first stage is the ring-opening copolymerization reaction of the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane with octamethylcyclotetrasiloxane. The second stage is the ring-opening copolymerization reaction continued after the addition of the end-capping agent hexamethyldisiloxane. The ring-opening copolymerization reaction is carried out under a negative pressure of -0.99 MPa to -0.95 MPa and at 70-80°C. The first stage reaction lasts for 10-40 mins, and the second stage reaction lasts for 1.5-3.5 h.

2. The method as described in claim 1, characterized in that, The 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane is 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane. .

3. The method as described in claim 1, characterized in that, In the ring-opening copolymerization reaction, the mass ratio of the hydrolysate of octamethylcyclotetrasiloxane, 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane, and the end-capping agent is 50~90:5~50:0.1~2.

0.

4. The method as described in claim 1, characterized in that, The solvent is dimethylformamide; the catalyst is selected from one or a mixture of two of tetramethylammonium hydroxide silanolate and sodium methylsilanolate.

5. The method according to any one of claims 1-4, characterized in that, In the ring-opening copolymerization reaction, the mass of the solvent used is 10% to 100% of the mass of octamethylcyclotetrasiloxane.

6. The method according to any one of claims 1-4, characterized in that, The polyether is polyethylene glycol.

7. The method according to any one of claims 1-4, characterized in that, The mass ratio of the catalyst to the substance that can form a supramolecular complex with the catalyst is (0.02 ~ 1):

1.

8. The method as described in claim 7, characterized in that, The mass ratio of the catalyst to the substance that can form a supramolecular complex with the catalyst is (0.05 ~ 0.1):

1.

9. The method according to any one of claims 1-4, characterized in that, The alkaline conditions for preparing the hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane were provided by an aqueous solution of 0.15 wt% to 0.4 wt% sodium hydroxide.

10. The method as described in claim 9, characterized in that, The mass ratio of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to sodium hydroxide aqueous solution is (0.5~18):

1.

11. The method as described in claim 10, characterized in that, The mass ratio of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to sodium hydroxide aqueous solution is (2-18):

1.

12. The method as described in claim 11, characterized in that, The mass ratio of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to sodium hydroxide aqueous solution is (5-18):

1.

13. The method as described in claim 12, characterized in that, The mass ratio of 3-[(2,3)-epoxypropoxy]propylmethyldialkoxysilane to sodium hydroxide aqueous solution is (9-18):

1.

14. The method according to any one of claims 1-4, characterized in that, The preparation of the hydrolysate further includes dehydrating the hydrolysate under negative pressure, wherein the dehydration process essentially removes the free water from the hydrolysate, so that the free water content is ≤1%, in order to obtain the final hydrolysate; the negative pressure is -0.99 MPa ~ -0.95 MPa.

15. The method according to any one of claims 1-4, characterized in that, After the ring-opening copolymerization reaction is completed, the temperature is increased to deactivate the catalyst and remove low-molecular-weight compounds from the reaction system.

16. The method according to any one of claims 1-4, characterized in that, It also includes the steps of separating and collecting the oil phase, washing it with water until neutral, and allowing it to stand and cool to obtain epoxy-modified silicone oil.

17. The method as described in claim 1, characterized in that: 1) Preparation of hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane: 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane was mixed with 0.15 wt.% ~ 0.4 wt.% sodium hydroxide aqueous solution in a closed container, stirred at a constant speed, and hydrolyzed at atmospheric pressure and 10~15℃ for 0.5~2.0 h; then dehydrated under reduced pressure of -0.99MPa ~ -0.95MPa for 0.5~2.0 h, and after cooling, allowed to stand to obtain hydrolysate of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane; 2) Ring-opening copolymerization reaction: Octamethylcyclotetrasiloxane is mixed with the hydrolysate obtained in step 1), and dimethylformamide, a catalyst, and a substance that can form a supramolecular complex with the catalyst are added. The substance is selected from one or more of crown ethers, cryptethers, and polyethers. The reaction is first carried out under reduced pressure of -0.99MPa to -0.95MPa and at 70-80℃ for 20-30 mins; then, the end-capping agent hexamethyldisiloxane is added; the reaction is continued for another 2.0-3.0 h; after that, the temperature is raised to 160℃ to deactivate the catalyst and remove low molecular weight compounds from the reaction system for 0.5-2.0 h. Optional, further including step 3): Separate and collect the oil phase and wash it with water until neutral, then let it stand and cool to obtain epoxy-modified silicone oil.

18. The method as described in claim 17, characterized in that, The polyether is selected from polyethylene glycol.

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