Polyether modified T-type siloxane wetting agent and preparation method thereof

Abstract

The invention belongs to the technical field of organosilicon materials, and relates to a polyether modified T-type siloxane wetting agent and a preparation method thereof. The structural formula of the polyether modified T-type siloxane wetting agent is shown in the specification. The polyether modified T-type siloxane wetting agent can remarkably reduce the surface tension of liquid, and the wetting agent is endowed with good spreading performance due to the similar umbrella-shaped molecular structure and has excellent wetting performance. Meanwhile, the polyether modified T-type siloxane wetting agent is added with methyl and a certain proportion of propoxy in a T-type structure, so that a silicon-oxygen bond is protected, the wetting agent can have good acid and alkali resistance stability, and the performance of the wetting agent can be kept stable under different environmental conditions; meanwhile, the preparation method is simple and easy to implement, raw materials are easy to obtain, and the method is suitable for large-scale industrial production. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of organic silicon materials, and in particular to a polyether-modified T-type siloxane wetting agent and a preparation method thereof. Background Art

[0002] Wetting agents play a vital role in many agricultural and industrial applications. Good wetting agents can significantly reduce the surface tension of liquids and improve the wetting and spreading properties of liquids on solid surfaces. However, existing wetting agents have problems such as insufficient performance and poor stability in certain specific application scenarios. Therefore, it is of great significance to develop a new wetting agent with excellent performance and good stability.

[0003] In the prior art, heptamethyltrisiloxane is usually used as a raw material to prepare a polyether-modified silicone oil with an "umbrella-shaped" structure. This structure has good wetting and spreading properties, but the exposure of its silicon-oxygen bonds makes it easily attacked by H + and OH - The attack of the acid and alkali hydrolysis resistance has deteriorated, and its use conditions are limited. Some patents have also improved their hydrolysis resistance through modification methods. For example, patent document CN101905134A discloses a hydrolysis-resistant double-tail trisiloxane surfactant containing alkyl trioxy groups. The prepared surfactant can not be hydrolyzed for 60 days under the conditions of pH = 4 and pH = 10; patent document CN101969780A discloses a hydrolysis-resistant organic modified trisiloxane ionic surfactant that has hydrolysis resistance in acid and alkaline. However, in order to achieve the purpose of hydrolysis resistance, the preparation process and molecular structure of the polyether-modified silicone surfactant prepared in the above patents are too complicated, difficult to prepare, and not conducive to large-scale production.

[0004] Based on this, the object of the present invention is to provide a tris(trimethylsiloxy)silane polyether modified T-type siloxane-based wetting agent and a preparation method thereof, wherein the wetting agent has good wetting performance and stability, and the preparation method is simple and easy to apply to industrial large-scale production. Summary of the invention

[0005] In view of the above-mentioned existing technical problems, the present invention provides a polyether-modified T-type siloxane wetting agent and a preparation method thereof. The present invention uses tris(trimethylsiloxy)silane and allyl polyether as raw materials and prepares the polyether-modified T-type siloxane wetting agent under the catalysis of a catalyst. The prepared polyether-modified silicone oil has a methyl group and a certain proportion of propoxy groups in its T-type structure, thereby protecting the siloxane bond, so that it has good acid and alkali resistance stability, and its "umbrella-like" molecular structure also gives the polyether-modified T-type siloxane wetting agent good spreading performance.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] One of the purposes of the present invention is to provide a polyether-modified T-type siloxane wetting agent, the general structural formula of the polyether-modified T-type siloxane wetting agent is as follows:

[0008]

[0009] In the formula, m is in the range of 5-10, n is in the range of 0-5, and R is one of -H, -CH3, and -C2H6.

[0010] The present invention adopts the polyether-modified T-type siloxane of the general structural formula as a wetting agent, which can show excellent wetting performance and excellent stability. The polyether-modified T-type siloxane wetting agent can significantly reduce the surface tension of the liquid, and its "umbrella-shaped" molecular structure gives the wetting agent good spreading performance and excellent wetting performance; at the same time, the polyether-modified T-type siloxane wetting agent has a methyl group and a certain proportion of propoxy groups in its T-type structure, thereby protecting the silicon-oxygen bond, so that it can have good acid and alkali resistance stability, and can maintain its stable performance under different environmental conditions.

[0011] The second object of the present invention is to provide a method for preparing the above-mentioned polyether-modified T-type siloxane wetting agent, wherein the preparation method is to use tris(trimethylsiloxy)silane and allyl polyether as raw materials, and react to obtain a polyether-modified T-type siloxane wetting agent; wherein the structure of the allyl polyether is as follows:

[0012]

[0013] wherein m ranges from 5 to 10, n ranges from 0 to 5, and R is -H, -CH3 or -C2H6.

[0014] Preferably, the preparation method comprises: putting a certain amount of tris(trimethylsiloxy)silane and all the allyl polyether into a reactor at one time, adding a stabilizer, heating the temperature to 80-85°C under stirring, adding a Pt catalyst, and gradually dripping the remaining tris(trimethylsiloxy)silane after the reaction exotherm ends, and the dripping speed is controlled to control the system temperature at 90-100°C; after the reaction ends, the temperature is lowered and the material is collected, and the reaction is carried out under a protective atmosphere throughout. More preferably, after the Pt catalyst is added and the exotherm ends, the temperature is controlled to 90-92°C and then the remaining tris(trimethylsiloxy)silane is dripped. During the reaction, the temperature is controlled at 90-92°C and then the remaining tris(trimethylsiloxy)silane is dripped, which can further make the reaction smooth and complete, and no side reactions occur. If the temperature control temperature is too low, the reaction will be incomplete and the energy consumption will be high.

[0015] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0016] Optionally, the mass ratio of the tris(trimethylsiloxy)silane to the allyl polyether is 2-3:8-7. Within this range, the reaction can be further ensured to be complete.

[0017] Optionally, the amount of tris(trimethylsiloxy)silane added for the first time is 10%-20% of the total mass of tris(trimethylsiloxy)silane. Within this range, the reaction can be effectively promoted to proceed stably and the occurrence of side reactions can be further avoided; if the amount of feed exceeds the range, the reaction may release heat too quickly, which is dangerous, and the side reactions increase, and the structure is destroyed.

[0018] Optionally, the stabilizer includes at least one of 2-(dibutylamino)ethanol, organic carboxylates, and vitamin E; more preferably, the organic carboxylates include at least one of sodium acetate, sodium citrate, and sodium propionate; more preferably, the stabilizer is added in an amount of 200-500 ppm of the total mass of tris(trimethylsiloxy)silane and allyl polyether. The stabilizer can further promote the stable progress of the reaction and further avoid the occurrence of side reactions.

[0019] Optionally, the stirring rate is 200-400 rpm.

[0020] Optionally, the Pt catalyst is an ethanol or isopropanol solution of chloroplatinic acid, or at least one of a Karstedt catalyst; more preferably, the amount of the Pt catalyst added converted to Pt is 1-5 ppm of the total mass of tri(trimethylsiloxy)silane and allyl polyether.

[0021] Optionally, the dropping speed varies depending on the amount of feed, and the system temperature can be controlled within 90-100° C. by adding the remaining tris(trimethylsiloxy)silane within 4-5 hours.

[0022] Optionally, the reaction is terminated with a silicon hydrogen content of ≤0.1 ml / g as a standard.

[0023] Optionally, the protective atmosphere includes at least one of nitrogen, helium and argon.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention provides a polyether-modified T-type siloxane wetting agent and a preparation method thereof. The tris(trimethylsiloxy)silane polyether-modified T-type siloxane-based wetting agent prepared by the invention has excellent wetting performance, can significantly reduce the surface tension of a liquid, and improve the wetting and spreading ability of a liquid on a solid surface; and the wetting agent has good hydrolysis resistance, can maintain its stable performance under different environmental conditions, and exhibits excellent stability; thus, the wetting agent has broad market application prospects in the fields of agricultural aids and the like; and the preparation method of the invention is simple and easy to implement, and the raw materials are readily available, and the agent is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 These are sample diagrams of Example 1, Example 2, Example 3 and Example 4 of the present invention. DETAILED DESCRIPTION

[0027] The content of the present invention is described in more detail below through examples, but the following examples are only used to illustrate the content of the present invention, rather than to limit it, so any changes within the meaning and scope equivalent to the claims of the present invention should be considered to be included in the scope of the claims of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. Unless otherwise specified, the reagents and materials used in the present invention are commercially available. The reaction conditions embodied in the content of the present invention are all capable of achieving the reaction and obtaining the product of the expected effect. Due to space limitations, some embodiments are listed below to further illustrate the advantages of the technical solution of the present invention.

[0029] Example 1

[0030] 20g tris(trimethylsiloxy)silane and 800g CH2=CHCH2(C2H4O)5(C3H6O)5H were put into the reactor at one time, 300ppm sodium propionate was added, the temperature was heated to 80°C under stirring at 300rpm, and 2ppm Pt catalyst was added, the Pt catalyst was 1wt.% chloroplatinic acid ethanol solution. The amount of sodium propionate added as stabilizer and the amount of Pt catalyst added (in terms of Pt) were both based on the total mass of tris(trimethylsiloxy)silane and allyl polyether. After the exothermic reaction is over, the temperature of the reaction system rises to about 91°C and is controlled at 90-92°C. The remaining 180g of tri(trimethylsiloxy)silane is gradually added dropwise. The addition is completed within 4 hours and the system temperature is controlled at 90-100°C. After the reaction is completed, the silicon hydrogen reaction is complete and the temperature is lowered to below 50°C to obtain a polyether modified T-type siloxane wetting agent. The entire reaction is carried out under a nitrogen atmosphere.

[0031] Example 2

[0032] 60g of tris(trimethylsiloxy)silane and 700g of CH2=CHCH2(C2H4O)2(C3H6O)5H were put into the reactor at one time, 400ppm of 2-(dibutylamino)ethanol was added, and the temperature was heated to 80°C under stirring at 300rpm. A 1wt.% chloroplatinic acid ethanol solution containing 3ppm Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 240g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 4.5h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The whole reaction was carried out under a nitrogen atmosphere.

[0033] Example 3

[0034] 25g of tris(trimethylsiloxy)silane and 750g of CH2=CHCH2(C2H4O)8(C3H6O)6H were put into the reactor at one time, 300ppm of sodium acetate was added, and the temperature was heated to 80°C under stirring at 300rpm. A 1wt.% chloroplatinic acid ethanol solution of 3ppm Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 225g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 4.5h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The reaction was carried out under a nitrogen atmosphere throughout.

[0035] Example 4

[0036] 20g of tris(trimethylsiloxy)silane and 800g of CH2=CHCH2(C3H6O)8H were put into the reactor at one time, 500ppm of sodium citrate was added, and the temperature was heated to 80°C under stirring at 300rpm. 5wt.‰Karstedt catalyst with 1ppm of Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 180g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 4h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon-hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The whole reaction was carried out under a nitrogen atmosphere.

[0037] Comparative Example 1

[0038] 200 g of tris(trimethylsiloxy)silane and 800 g of CH2=CHCH2(C2H4O)5(C3H6O)5H were put into the reactor at one time, 300 ppm of sodium propionate was added, and the temperature was heated to 80°C under stirring at 300 rpm. A 1 wt.% chloroplatinic acid ethanol solution containing 2 ppm of Pt catalyst was added, and the temperature was raised to 130°C after the exothermic reaction was completed. After the reaction was completed, the silicon-hydrogen reaction was complete, and the temperature was lowered to below 50°C to collect the material. The whole reaction was carried out under a nitrogen atmosphere.

[0039] Comparative Example 2

[0040] 40g of tris(trimethylsiloxy)silane and 600g of CH2=CHCH2(C2H4O)2(C3H6O)5H were put into the reactor at one time, 400ppm of sodium acetate was added, and the temperature was heated to 80°C under stirring at 300rpm. A 1wt.% chloroplatinic acid ethanol solution of 3ppm Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 360g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 5h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen was not completely reacted, and the temperature was lowered to below 50°C to collect the material. The whole reaction was carried out under a nitrogen atmosphere.

[0041] Comparative Example 3

[0042] 60g of tris(trimethylsiloxy)silane and 700g of CH2=CHCH2(C2H4O)6H were put into the reactor at one time, 300ppm of 2-(dibutylamino)ethanol was added, and the temperature was heated to 80°C under stirring at 300rpm. A 1wt.% chloroplatinic acid ethanol solution of 3ppm Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 240g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 4.5h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The whole reaction was carried out under a nitrogen atmosphere.

[0043] Comparative Example 4

[0044] 60 g of tris(trimethylsiloxy)silane and 800 g of CH2=CHCH2(C3H6O)8H were put into the reactor at one time, 300 ppm of sodium propionate was added, and the temperature was heated to 80°C under stirring at 300 rpm. A 1 wt.% chloroplatinic acid ethanol solution containing 2 ppm of Pt catalyst was added. After the exothermic reaction was completed, the temperature was raised to 110°C, and then dropped to 90-92°C. The remaining 140 g of tris(trimethylsiloxy)silane was gradually added dropwise. The addition was completed within 4 hours, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The whole reaction was carried out under a nitrogen atmosphere.

[0045] Comparative Example 5

[0046] 60g of heptamethyltrisiloxane and 750g of CH2=CHCH2(C2H4O)6H were put into the reactor at one time, 300ppm of sodium propionate was added, and the temperature was heated to 80°C under stirring at 300rpm. A 1wt.% chloroplatinic acid ethanol solution of 3ppm Pt catalyst was added. After the exothermic reaction was completed, the temperature was controlled to 90-92°C, and the remaining 240g of heptamethyltrisiloxane was gradually added dropwise. The addition was completed within 4.5h, and the system temperature was controlled at 90-100°C. After the reaction was completed, the silicon hydrogen reaction was complete, and the temperature was lowered to below 50°C for collection. The reaction was carried out under a nitrogen atmosphere throughout.

[0047] Performance Testing

[0048] The polyether-modified silicone surfactants prepared in Examples 1 to 4 and the polyether-modified silicone surfactants prepared in Comparative Examples 1 to 5 were tested for surface tension, spreadability, acid and alkali resistance stability, and residual silicon hydrogen content.

[0049] The specific test method is as follows:

[0050] Surface tension: The surface tension was tested using the JK99B fully automatic tension meter with platinum plate method.

[0051] Spreadability test: dilute the sample into a 0.1% aqueous solution, then drop 25 μl of the sample onto a culture dish under constant temperature (40-60°C) and constant humidity (80-100% RH) conditions, allow it to diffuse freely, and measure its expansion diameter after 1 minute.

[0052] Acid and alkali stability test: HAc and AMP-95 were used to prepare aqueous solutions of pH = 4 and pH = 10, and then the samples were diluted with these aqueous solutions to become 0.1% solutions, and the surface tension of different pH values ​​was tested every two months.

[0053] Test for residual silicon hydrogen: Fill a fermentation tube with alkali solution (20% ethanol solution), take 1 g of polyether-modified silicone oil, mix it thoroughly with the alkali solution, and read the volume of hydrogen produced.

[0054] The test results are shown in Table 1-3.

[0055] Table 1 Properties of polyether modified T-type siloxane wetting agents

[0056]

[0057] Table 2 Acid resistance (pH = 4) stability of polyether modified T-type siloxane wetting agent

[0058]

[0059]

[0060] Table 3 Alkali resistance (pH = 10) stability of polyether modified T-type siloxane wetting agent

[0061]

[0062] As can be seen from Table 1, the surface tension and spreading diameter of the polyether-modified T-type siloxane wetting agent prepared by Examples 1 to 4 under the raw material ratio and process parameters of the present invention are good. However, due to the change in the feeding method and the first feeding ratio of tri(trimethylsiloxy)silane, Comparative Examples 1 and 4 failed to control the reaction temperature of the system within 90-100°C, resulting in side reactions and poor spreading properties; Comparative Example 2 had a relatively large feeding amount of tri(trimethylsiloxy)silane, so the silicon-hydrogen reaction was not complete, which would affect the use of the product in the later stage and the product quality was not guaranteed; Comparative Example 3 had only ethoxy groups. As can be seen from Tables 2-3, the other embodiments and comparative examples showed excellent hydrolysis resistance due to the structure required by the present invention. The hydrolysis resistance of Comparative Example 3 was poor due to the absence of propoxy groups in the allyl polyether, which made H + and OH - It is easier to attack the silicon-oxygen bond, making its acid-base stability worse. Comparative Example 5 Since the wetting agent is synthesized from heptamethyltrisiloxane, there is no T-shaped structure to protect the silicon-oxygen bond, so H + and OH - It is easy to attack its main structure, which can be reflected from the significant decrease of its surface tension and spreading diameter with the extension of storage time under acid and alkaline conditions.

[0063] In summary, it can be seen from the examples and comparative examples that only the polyether-modified T-type siloxane wetting agent prepared under the raw material ratio and process parameters required by the patent of the present invention can comprehensively have good spreadability, reduce surface tension and acid-base stability.

[0064] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A polyether-modified T-type siloxane wetting agent, characterized in that: The structural formula of the polyether-modified T-type siloxane wetting agent is as follows: In the formula, m is in the range of 5-10, n is in the range of 0-5, and R is one of -H, -CH3, and -C2H6.

2. A method for preparing the polyether-modified T-type siloxane wetting agent as claimed in claim 1, characterized in that: The preparation method is to use tris(trimethylsiloxy)silane and allyl polyether as raw materials to react and obtain a polyether-modified T-type siloxane wetting agent; wherein the structure of the allyl polyether is as follows: wherein m ranges from 5 to 10, n ranges from 0 to 5, and R is -H, -CH3 or -C2H6.

3. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 2, characterized in that: The preparation method comprises: putting a certain amount of tri(trimethylsiloxy)silane and all the allyl polyether into a reactor, adding a stabilizer, heating the temperature to 80-85°C under stirring, adding a Pt catalyst, and gradually dropping the remaining tri(trimethylsiloxy)silane after the exothermic reaction ends, and controlling the system temperature at 90-100°C during the dropping process; and the whole reaction is carried out under a protective atmosphere.

4. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 2, characterized in that: The mass ratio of the tris(trimethylsiloxy)silane to the allyl polyether is 2-3:8-7.

5. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 3, characterized in that: The amount of tri(trimethylsiloxy)silane added for the first time is 10%-20% of the total mass of tri(trimethylsiloxy)silane.

6. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 3, characterized in that: The stabilizer is at least one of 2-(dibutylamino)ethanol, organic carboxylate and vitamin E.

7. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 6, characterized in that: The amount of the stabilizer added is 200-500 ppm based on the total mass of tri(trimethylsiloxy)silane and allyl polyether.

8. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 3, characterized in that: The Pt catalyst is at least one of an ethanol solution of chloroplatinic acid, an isopropanol solution of chloroplatinic acid, and a Karstedt catalyst.

9. The method for preparing a polyether-modified T-type siloxane wetting agent according to claim 8, characterized in that: The amount of the Pt catalyst added is 1-5 ppm based on the total mass of tri(trimethylsiloxy)silane and allyl polyether in terms of Pt.

10. A method for preparing a polyether-modified T-type siloxane wetting agent according to any one of claims 2 to 9, characterized in that: The reaction is terminated when the content of silicon hydrogen is ≤ 0.1 ml / g.

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