A process for the preparation of a sulfonate-based anionic organosilicon surfactant

Abstract

The present application relates to the technical field of silicone surfactant, in particular to a preparation method of anionic silicone surfactant based on sulfonate, which comprises the following steps: mixing, stirring and heating deionized water, solvent and end monoglycidyl ether terminated polydimethylsiloxane to 60-80 DEG C, adding dropwise ethylenediamine ethanesulfonic acid sodium aqueous solution, after dropwise addition, reacting at 60-80 DEG C until the material changes from turbid to transparent, obtaining transparent material, distilling the transparent material under reduced pressure to remove solvent and deionized water, obtaining anionic silicone surfactant based on sulfonate; the molar ratio of end monoglycidyl ether terminated polydimethylsiloxane and ethylenediamine ethanesulfonic acid sodium is (1.8-2):1. The novel silicone surfactant has good water solubility and strong salt resistance, significantly reduces the interfacial tension between water and silicone oil, and improves the stability of silicone oil in water-based resin, especially water-based polyurethane system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone surfactants, and particularly relates to a preparation method of an anionic silicone surfactant based on sulfonate. BACKGROUND

[0002] In order to play the roles of slip, wear resistance and hand feeling, water-based polyurethane resin and paint often add water-based silicone oil. Because the interface energy difference between silicone oil and water is very large, in the actual use process, the stability of silicone oil in the paint is not good, and the silicone oil is easy to precipitate, resulting in a series of problems such as shrinkage, shrinkage, uneven spraying thickness and the like of the water-based polyurethane resin paint. The surfactant is generally an organic amphiphilic molecule with hydrophilic and hydrophobic groups, and can be dissolved in organic solution and aqueous solution. In order to improve the stability of silicone oil in the paint, the key is to select a surfactant which can reduce the interface energy difference between water and silicone oil, and has good compatibility and compatibility with water-based resin.

[0003] The organic silicone surfactant is a new type of surfactant developed with the development of new organic silicone materials. The organic silicone surfactant is composed of polysiloxane and hydrophilic group. Due to the low surface tension and weak intermolecular force of polysiloxane, the organic silicone surfactant has excellent surface tension reduction performance, and excellent wetting property, defoaming property and foam stability. The organic silicone surfactant has good compatibility with silicone oil due to the similar molecular structure, can significantly reduce the interfacial tension between water and silicone oil, and form a stable oil-in-water emulsion.

[0004] However, the water-solubility of the current organic silicone surfactant is poor, the salt resistance is weak, the stability and antistatic property of water-based silicone oil are reduced, and especially the compatibility and compatibility of the organic silicone surfactant with water-based polyurethane paint are poor. Therefore, the present application needs to develop an organic silicone surfactant with good water-solubility, strong salt resistance, good compatibility and compatibility with water-based polyurethane paint. SUMMARY

[0005] In order to improve the defects of poor water-solubility, weak salt resistance and poor compatibility and compatibility of the organic silicone surfactant with water-based polyurethane paint, the present application provides a preparation method of an anionic silicone surfactant based on sulfonate.

[0006] In a first aspect, the present application provides a preparation method of an anionic silicone surfactant based on sulfonate, which adopts the following technical scheme:

[0007] The preparation method of the anionic silicone surfactant based on sulfonate comprises the following steps:

[0008] Mixing stirring deionized water, solvent and end monoglycidyl ether terminated polydimethylsiloxane, heating to 60-80℃, adding dropwise sodium ethylenediamine ethanesulfonate aqueous solution, after dropwise addition, reacting at 60-80℃ until the material changes from turbidity to transparency, obtaining transparent material, distilling the transparent material under reduced pressure to remove solvent and deionized water, obtaining sulfonate-based anionic organosilicon surfactant; the molar ratio of the end monoglycidyl ether terminated polydimethylsiloxane and sodium ethylenediamine ethanesulfonate is (1.8-2):1.

[0009] By adopting the above technical scheme, the application uses end monoglycidyl ether terminated polydimethylsiloxane to carry out addition reaction with sodium ethylenediamine ethanesulfonate in aqueous phase, synthesizes a sulfonate-based anionic organosilicon surfactant, which is a new type of organosilicon surfactant. On the one hand, the sulfonate-based anionic organosilicon surfactant prepared by the application has a strong hydrophilic sulfonate group, which is a sulfonate system with good salt formation. It not only improves the stability, compatibility and antistatic property of water-based silicone oil, but also forms good compatibility and stability with anionic water-based polyurethane resin, thereby improving the stability of silicone oil in the water-based polyurethane system. On the other hand, the sulfonate-based anionic organosilicon surfactant prepared by the application contains a similar molecular structure to silicone oil, which improves its compatibility with silicone oil, significantly reduces the interfacial tension between water and silicone oil, and then forms a stable oil-in-water emulsion, enabling the preparation of storage-stable water-based organosilicon oil, so that water-based organosilicon oil can be widely used in surface treatment of leather, synthetic leather and textile coating.

[0010] Preferably, the number average molecular weight of the end monoglycidyl ether terminated polydimethylsiloxane is 5000-15000.

[0011] By adopting the above technical scheme, the end monoglycidyl ether terminated polydimethylsiloxane with a number average molecular weight of 5000-15000 is conducive to the addition reaction of sodium ethylenediamine ethanesulfonate aqueous solution, thereby improving the salt resistance of the surfactant and reducing the interfacial tension of the surfactant.

[0012] Preferably, the mass ratio of the end monoglycidyl ether terminated polydimethylsiloxane and deionized water is 1:(0.8-1.2).

[0013] More preferably, the mass ratio of the end monoglycidyl ether terminated polydimethylsiloxane and deionized water is 1:1.

[0014] By adopting the technical scheme, the mass ratio of the end monoglycidyl ether-terminated polydimethylsiloxane and the deionized water is 1:1, which is beneficial to ring-opening of the end monoglycidyl ether-terminated polydimethylsiloxane, and thus is beneficial to addition reaction of the end monoglycidyl ether-terminated polydimethylsiloxane and sodium ethylenediamine ethanesulfonate, and the salt resistance and water solubility of the silicone surfactant are improved, and the surfactant can better reduce the interfacial tension between water and silicone oil.

[0015] Preferably, the concentration of the sodium ethylenediamine ethanesulfonate aqueous solution is 40-60 wt%.

[0016] More preferably, the concentration of the sodium ethylenediamine ethanesulfonate aqueous solution is 50 wt%.

[0017] By adopting the technical scheme, the concentration of the sodium ethylenediamine ethanesulfonate aqueous solution is increased from 40 wt% to 50 wt%, the salt resistance of the surfactant is enhanced, and the surface tension is reduced; and the concentration of the sodium ethylenediamine ethanesulfonate aqueous solution is increased from 50 wt% to 60 wt%, the surface tension is increased, and the salt resistance is also reduced.

[0018] Preferably, the dropping time of the sodium ethylenediamine ethanesulfonate aqueous solution is 2-3 h.

[0019] By adopting the technical scheme, the dropping time of the sodium ethylenediamine ethanesulfonate aqueous solution is 2-3 h, the sodium ethylenediamine ethanesulfonate better occurs addition reaction with the end monoglycidyl ether-terminated polydimethylsiloxane, the reaction rate is controlled, and the yield of the product is also improved, and the molecular weight of the product is controlled.

[0020] Preferably, the solvent is one or a combination of several of isopropyl alcohol, ethanol and methanol.

[0021] Preferably, the mass ratio of the solvent and the end monoglycidyl ether-terminated polydimethylsiloxane is (1-1.5):(3-10).

[0022] In summary, the application has the following beneficial effects:

[0023] 1. The application adopts the end monoglycidyl ether-terminated polydimethylsiloxane to occur addition reaction with sodium ethylenediamine ethanesulfonate in an aqueous phase, and a novel silicone surfactant containing a sulfonate is synthesized, which has good water solubility, strong salt resistance, significantly reduces the interfacial tension between water and silicone oil, and improves the stability of the silicone oil in a waterborne polyurethane system.

[0024] 2. The application adopts the end monoglycidyl ether-terminated polydimethylsiloxane with a number average molecular weight of 5000-15000, improves the salt resistance of the anionic silicone surfactant based on the sulfonate, and reduces the interfacial tension of the surfactant.

[0025] 3、The application uses a 50wt% ethylenediamine sodium ethanesulfonate aqueous solution, and the sulfonate-based anionic silicone surfactant has strong salt resistance and low surface tension. DETAILED DESCRIPTION

[0026] The application will be further described in detail below in combination with examples.

[0027] Examples

[0028] Examples 1-15 provide a preparation method of a sulfonate-based anionic silicone surfactant, which will be described below by taking Example 1 as an example.

[0029] The preparation method of the sulfonate-based anionic silicone surfactant provided in Example 1 has the following steps:

[0030] 500g of deionized water, 100g of isopropyl alcohol, and 500g of polydimethylsiloxane capped with terminal monoglycidyl ether (number average molecular weight of 5000) were added to a reaction kettle, mixed, and stirred at a speed of 100rpm for 10min, and then heated to 60℃. 26g of a 40wt% ethylenediamine sodium ethanesulfonate aqueous solution was added dropwise, and the dropwise addition was completed in 3h. The reaction was continued at 60℃ until the material changed from turbid to transparent. The transparent material was obtained, and the pH of the transparent material was tested. If the pH was about 7.5, the heating was stopped. The transparent material was distilled under reduced pressure. The pressure of the reduced pressure distillation was controlled to be 20mmHg, and the temperature of the reduced pressure distillation was controlled to be 100℃. Isopropyl alcohol and 95wt% deionized water were removed. The material was in a viscous and turbid state, and the sulfonate-based anionic silicone surfactant was obtained.

[0031] Example 2 differs from Example 1 only in that the temperature of the addition reaction of the polydimethylsiloxane capped with terminal monoglycidyl ether and the ethylenediamine sodium ethanesulfonate is 80℃.

[0032] Examples 3-6 differ from Example 2 only in that the concentration and mass of the ethylenediamine sodium ethanesulfonate aqueous solution are different, as shown in Table 1.

[0033] Table 1 Concentration and mass of ethylenediamine sodium ethanesulfonate aqueous solution in Examples 2, 3-6

[0034]

[0035]

[0036] Example 7 differs from Example 4 only in that the dropwise addition time of the ethylenediamine sodium ethanesulfonate aqueous solution is 2h.

[0037] Examples 8-13 differ from Example 4 only in that the number average molecular weight and mass of the terminal monoglycidyl ether-capped polydimethylsiloxane, the mass of deionized water are different, see Table 2.

[0038] Table 2 Number average molecular weight and mass of the terminal monoglycidyl ether-capped polydimethylsiloxane, mass of deionized water of Examples 4, 8-13

[0039]

[0040] Examples 14-15 differ from Example 10 only in that the type and mass of the solvent are different, see Table 3.

[0041] Table 3 Type and mass of the solvent of Examples 10, 14-15

[0042]

[0043] Performance detection tests were carried out on the sulfonate-based anionic organosilicon surfactants prepared in Examples 1-15 of the application as follows.

[0044] 1. Surface tension

[0045] An aqueous silicone oil was prepared by mixing the silicone oil and deionized water at a mass ratio of 1:4, stirring uniformly, and obtaining an aqueous silicone oil;

[0046] 1 g of the sulfonate-based anionic organosilicon surfactant prepared in Examples 1-15 was added to 1000 g of the above aqueous silicone oil, mixed uniformly, and a mixed solution was obtained; the surface tension of the mixed solution at 25°C was determined according to the method of GB / T 5549-2010 “Surface tension of surfactants by the pull-up liquid film method”, and the test results are shown in Table 4.

[0047] 2. Stability of aqueous silicone oil

[0048] An aqueous silicone oil was prepared by mixing the silicone oil and deionized water at a mass ratio of 1:4, stirring uniformly, and obtaining an aqueous silicone oil;

[0049] 1 g of the sulfonate-based anionic organosilicon surfactant prepared in Examples 1-15 was added to 1000 g of the above aqueous silicone oil, mixed uniformly, and a mixed solution was obtained;

[0050] The mixed solution was placed at 25°C for 1 h, and whether the mixed solution and the above aqueous silicone oil were layered was observed, and the test results are shown in Table 4.

[0051] 3. Stability of silicone oil in aqueous polyurethane paint

[0052] Preparation of the silicone oil aqueous polyurethane solution: 1 g of the silicone oil was mixed with 20 g of the ADM-6556A aqueous polyurethane varnish according to the mass ratio of 1:20, and stirred uniformly to obtain a silicone oil aqueous polyurethane solution;

[0053] 1 g of the sulfonate-based anionic organosilicon surfactant prepared in each of Examples 1-15 was added into 1000 g of the above silicone oil aqueous polyurethane solution, and mixed uniformly to obtain a polyurethane mixture;

[0054] The mixture was placed at 25℃ for 1 h, and whether the silicone oil in the polyurethane mixture and the silicone oil aqueous polyurethane solution was precipitated was observed, and the test results are shown in Table 4.

[0055] 4. Water solubility: 10 g of the sulfonate-based anionic organosilicon surfactant prepared in each of Examples 1-15 was added into 100 g of deionized water, and stirred uniformly. After being placed at 25℃ for 30 min, whether the mixture was layered was observed, and the test results are shown in Table 4.

[0056] 5. Salt resistance: the Ca 2+ Stability of the sulfonate-based anionic organosilicon surfactant prepared in each of Examples 1-15 and sodium dodecyl benzene sulfonate was determined according to the method of GB / T 7381-2010 “Determination method of stability of surfactants in hard water”, and the salt resistance was represented by the Ca

[0057] Table 4 Test results

[0058]

[0059]

[0060] The following details of the present application are based on the test data in Table 4.

[0061] The present application utilizes the addition reaction of the terminal monoglycidyl ether-terminated polydimethylsiloxane and sodium ethylenediamine sulfonate in the aqueous phase to synthesize a new type of organosilicon surfactant, which has a hydrophilic sulfonate group, good water solubility, Ca 2+ good stability, improves the water solubility and salt resistance of the organosilicon surfactant, and the salt resistance is also better than that of sodium dodecyl benzene sulfonate; at the same time, the organosilicon surfactant contains a similar molecular structure to the silicone oil, improves the stability of the aqueous silicone oil and the stability of the silicone oil in the aqueous polyurethane coating, significantly reduces the interfacial tension between the water and the silicone oil, and the surface activity is better than that of the polyether-modified organosilicon surfactant WET-628.

[0062] From the test data of Example 2, Example 3 or Example 4, Example 6, it can be known that, in the case of a certain concentration of the aqueous sodium ethylenediamine sulfonate solution, reducing the mass of the aqueous sodium ethylenediamine sulfonate solution can reduce the salt tolerance of the surfactant, but can improve the surface activity of the surfactant, and can reduce the surface tension performance, and the surface tension of water and silicone oil is relatively low.

[0063] From the test data of Example 3, 4, 5, it can be known that, in the case of a certain molar ratio of the end monoglycidyl ether-terminated polydimethylsiloxane and the aqueous sodium ethylenediamine sulfonate solution, when the concentration of the aqueous sodium ethylenediamine sulfonate solution increases from 40wt% to 50wt%, the salt tolerance of the surfactant is enhanced, and the surface tension is reduced; when the concentration of the aqueous sodium ethylenediamine sulfonate solution increases from 50wt% to 60wt%, the surface tension rises, and the salt tolerance also decreases.

[0064] From the test data of Example 4 and Example 8-9, it can be known that, in Example 4, the mass ratio of the end monoglycidyl ether-terminated polydimethylsiloxane and the deionized water is 1:1, in Example 8, the content of the deionized water is less, and in Example 9, the content of the deionized water is more, and reducing or increasing the mass of the deionized water is not conducive to reducing the interfacial tension of the surfactant, and is also not conducive to improving the salt tolerance of the surfactant.

[0065] From the test data of Example 4, Example 10-11 and Example 12-13, it can be known that, in the case of a certain mass ratio of the end monoglycidyl ether-terminated polydimethylsiloxane and the deionized water, increasing the number average molecular weight of the end monoglycidyl ether-terminated polydimethylsiloxane, the surface tension of the sulfonate-based anionic organosilicon surfactant shows a trend of first decreasing and then increasing, and the salt tolerance of the surfactant first becomes better and then becomes worse, wherein, the end monoglycidyl ether-terminated polydimethylsiloxane with a number average molecular weight of 5000-15000, especially the end monoglycidyl ether-terminated polydimethylsiloxane with a number average molecular weight of 10000, is more conducive to the addition reaction with the 50wt% aqueous sodium ethylenediamine sulfonate solution, reduces the interfacial tension of the surfactant, and improves the salt tolerance of the surfactant.

[0066] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A process for the preparation of a sulfonate-based anionic organosilicon surfactant, characterized in that, The method comprises the following steps: The deionized water, solvent and end monoglycidyl ether terminated polydimethylsiloxane are mixed and stirred, and the temperature is raised to 60-80℃. The aqueous solution of ethylenediamine ethanesulfonic acid sodium is added dropwise. After the dropwise addition is completed, the reaction is carried out at 60-80℃ until the material changes from turbid to transparent. The transparent material is subjected to reduced pressure distillation to remove the solvent and deionized water, and an anionic organic silicon surfactant based on sulfonate is obtained. The molar ratio of the end monoglycidyl ether terminated polydimethylsiloxane and the aqueous solution of ethylenediamine ethanesulfonic acid sodium is (1.8-2):

1. The mass ratio of the end monoglycidyl ether terminated polydimethylsiloxane and the deionized water is 1:

1. The number average molecular weight of the end monoglycidyl ether terminated polydimethylsiloxane is 5000-15000.

2. The method of preparing a sulfonate-based anionic organosilicon surfactant according to claim 1, characterized in that, The concentration of the aqueous solution of ethylenediamine ethanesulfonic acid sodium is 40-60wt%.

3. A process for the preparation of a sulfonate-based anionic organosilicon surfactant according to claim 2, characterized in that, The concentration of the aqueous solution of ethylenediamine ethanesulfonic acid sodium is 50wt%.

4. The method of claim 3, wherein the sulfonate-based anionic organosilicon surfactant is prepared by the reaction of a sulfonic acid with a hydrolyzed organosilicon compound. The dropwise addition time of the aqueous solution of ethylenediamine ethanesulfonic acid sodium is 2-3h.

5. A process for the preparation of a sulfonate-based anionic organosilicon surfactant according to any one of claims 1 to 4, characterized in that, The solvent is one or a combination of several of isopropyl alcohol, ethanol and methanol.

6. The method of preparing a sulfonate-based anionic organosilicon surfactant according to claim 5, characterized in that, The mass ratio of the solvent and the end monoglycidyl ether terminated polydimethylsiloxane is (1-1.5):(3-10).

Images