A dumbbell-shaped phosphate ester salt anionic organosilicon surfactant and a method for preparing the same

Abstract

This invention relates to the fields of organosilicon chemistry and surfactant technology, specifically to a dumbbell-shaped phosphate ester anionic organosilicon surfactant and its preparation method. It can be used in particle dispersion, wetting and emulsification, low surface tension regulation, inorganic filler slurry stabilization, and dispersion systems for coatings, inks, lithium battery pastes, and functional materials. This surfactant consists of a dumbbell-shaped backbone formed by two 1,3,5,7-tetramethylcyclotetrasiloxane residues linked by an intermediate chain segment R. Each cyclic end group is site-fixed to three polyether phosphate monoester salt arms Q. Its preparation includes a first hydrosilylation to construct a hydrogen-containing dumbbell intermediate, a second hydrosilylation to introduce polyether hydroxyl arms, and segmented phosphate esterification, hydrolysis, and neutralization steps. This invention features a regular structure, rich anchoring sites, and strong steric hindrance effect, which can improve the wetting, dispersion, and storage stability of inorganic particles, pigments, fillers, and lithium battery pastes.

Description

Technical Field

[0001] This invention relates to the fields of organosilicon chemistry and surfactant technology, specifically to a dumbbell-type phosphate ester anionic organosilicon surfactant and its preparation method, which can be used in particle dispersion, wetting emulsification, low surface tension regulation, inorganic filler slurry stabilization, and dispersion systems for coatings, inks, lithium battery slurries, and functional materials. Background Technology

[0002] Organosilicon surfactants are a class of functional surfactants that use siloxane segments as hydrophobic or low surface energy structural units and polyether segments or ionic groups as hydrophilic structural units. Compared with traditional hydrocarbon surfactants, organosilicon surfactants typically have lower surface tension, better spreading and wetting ability, and better temperature resistance, weather resistance, and chemical stability. Therefore, they are widely used in coatings, inks, pesticide auxiliaries, textile finishing, electronic chemicals, and inorganic powder dispersion. Most commercially available organosilicon surfactants are based on polyether-modified polysiloxanes. Their main structure is a combination of linear or comb-shaped polysiloxane backbone and side polyether segments, which can improve the wetting, spreading, and compatibility of the system. However, in applications requiring strong anchoring, high stable dispersion, or multi-point interfacial bonding, the simple nonionic polyether structure often cannot provide sufficient particle surface adsorption strength.

[0003] To enhance the binding ability of organosilicon surfactants to inorganic particles, pigments, fillers, or polar interfaces, existing technologies have explored the introduction of anionic groups such as phosphate esters, carboxylates, and sulfonates into polyether-modified organosilicon structures. Among these, phosphate ester-type organosilicon surfactants combine the low surface energy of organosilicon segments, the hydrophilic compatibility of polyether segments, and the coordination or hydrogen bonding effects of phosphate ester groups on the surfaces of metal oxides, inorganic pigments, fillers, and polar particles. Therefore, they have high application value in wetting and dispersing agents, emulsifiers, leveling agents, and slurry stabilizers. In the prior art, Chinese patent CN106084238A discloses a method for preparing a wetting and dispersing agent for matte powders. This method involves hydrosilylation of terminal allyl polyoxyethylene ethers with low-hydrogen silicone oil under the action of a catalyst to obtain a water-soluble polyether-modified organosilicon polymer. Phosphoric acid or phosphorus pentoxide is then added to the polymer for phosphorylation esterification, and the pH is adjusted by an amine to obtain the final product. This method can improve the wetting and dispersing performance of matte powder systems and reduce the risk of gelation side reactions by controlling the water content of the polyether.

[0004] Chinese patent CN106622018A discloses a composite organosilicon surfactant, which includes components such as a phosphate ester type organosilicon surfactant, a carboxylated polyether organosilicon surfactant, and a polyether-modified polysiloxane nonionic surfactant. The phosphate ester type organosilicon surfactant is made from hydrogen-containing silicone oil, allyl polyoxyethylene polyoxypropylene ether, chloroplatinic acid, and phosphorus pentoxide. The polyether segments are first introduced through a hydrosilylation reaction, and then esterified with phosphorus pentoxide to obtain a phosphate ester type organosilicon surfactant with low surface tension and certain emulsifying properties.

[0005] The aforementioned prior art describes a common route for preparing polyether-modified organosilicon phosphate surfactants: hydrosilylation of hydrogen-containing silicone oil with unsaturated polyether, followed by phosphate esterification. However, existing polyether organosilicon phosphates are mostly based on linear hydrogen-containing silicone oil or randomly distributed hydrogen-containing polysiloxanes as the backbone. The phosphate groups are typically randomly or laterally distributed along the polysiloxane chain segments, resulting in insufficient molecular structural regularity. Because the distribution of reaction sites is significantly influenced by the structure of the hydrogen-containing silicone oil, the resulting products often suffer from problems such as wide degree of substitution distribution, dispersed molecular weight, uncertain number of end groups, and poor batch-to-batch stability. When used for dispersing pigments, fillers, metal oxides, carbon materials, or lithium battery active materials in slurries, the randomly distributed phosphate groups may be partially masked by the polysiloxane chain segments, making it difficult for them to fully participate in interfacial anchoring, leading to insufficient utilization of effective anchoring sites per molecule.

[0006] Furthermore, when linear or comb-shaped polyether organosilicon phosphates adsorb onto particle surfaces, the molecular chains tend to lie flat or adhere locally, resulting in a limited steric hindrance layer thickness. When the particle concentration in the dispersion system is high, the particle surface is highly polar, or the system requires long-term storage, the steric repulsion provided by a single linear segment is insufficient, easily leading to problems such as secondary particle agglomeration, particle size rebound, increased sedimentation, or increased slurry viscosity. Although partially branched or hyperbranched phosphorus-containing organosilicon materials can increase molecular volume, they mostly rely on condensation or polymerization reactions to form branched structures. The degree of branching, end-group positions, and the number of effective anionic groups are difficult to control precisely, which is not conducive to obtaining organosilicon anionic surfactants with well-defined structures, high reproducibility, and suitability for industrial scale-up.

[0007] Therefore, there is still a need in the field for anionic organosilicon surfactants that differ from existing linear hydrogen-containing silicone oil phosphate esterification products. This surfactant should be able to achieve site-specific enrichment of anchoring groups and regular distribution of hydrophilic segments in its molecular structure, making the anionic phosphate ester groups more accessible. Simultaneously, it should provide stable steric support through the organosilicon cyclic end groups, thereby improving the problems of insufficient structural regularity, low anchoring site utilization, limited steric hindrance dispersion ability, and insufficient batch-to-batch consistency of existing organosilicon phosphate esters. Based on this, the development of a dumbbell-shaped phosphate ester salt anionic organosilicon surfactant and its preparation method, comprising a bi-terminal cyclic backbone composed of two 1,3,5,7-tetramethylcyclotetrasiloxane residues and site-specific introduction of multiple polyether phosphate monoester salt arms on each cyclic end group, is of clear technical necessity. Summary of the Invention

[0008] The technical objective of this invention is to provide a dumbbell-shaped phosphate ester anionic organosilicon surfactant and its preparation method, which involves constructing a bi-terminal cyclic backbone with two 1,3,5,7-tetramethylcyclotetrasiloxane residues and introducing polyether phosphate monoester salt arms at specific sites on each cyclic end group. This process forms a dumbbell-shaped molecular structure with a regular six-arm distribution, thereby solving the problems of uneven distribution of anionic anchoring groups, low utilization rate of effective anchoring points, insufficient steric hindrance dispersion ability, and poor batch-to-batch consistency of existing linear or random comb-shaped organosilicon phosphate surfactants.

[0009] Firstly, in order to achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A dumbbell-shaped phosphate ester anionic silicone surfactant, wherein the dumbbell-shaped phosphate ester anionic silicone surfactant comprises two 1,3,5,7-tetramethylcyclotetrasiloxane residues and an intermediate linking segment located between them. Forming a dumbbell-shaped framework, the two 1,3,5,7-tetramethylcyclotetrasiloxane residues are connected by a silicon atom via... The key is connected to the intermediate connecting chain segment. At both ends, each of the 1,3,5,7-tetramethylcyclotetrasiloxane residues did not participate in connecting the intermediate linker segment. The three silicon atoms were respectively processed by A polyether phosphate monoester salt arm is linked by a bond. This results in an average of 5.4–6.0 polyether phosphate monoester salt arms per molecule. ;

[0011] Among them, the polyether phosphate monoester salt arm It has the following structure:

[0012] ;

[0013] In the formula, Integers between 2 and 4; It is an ethylene oxide structural unit. It is a propylene oxide structural unit. It is an epoxybutane structural unit; The range is 1 to 10. The range is 0 to 10. The range is 0 to 5; and Each independently selected , , , Or organic amine cations, and and At least one of them is , , Or organic amine cations;

[0014] The intermediate connecting chain segment The segments are alkane segments or organosilicon segments, wherein the alkane segments are:

[0015] ;

[0016] The organosilicon segments are:

[0017] ;

[0018] In the formula, The range is 2 to 12. The range is 1 to 100. It indicates a methyl group.

[0019] The dumbbell-shaped anionic organosilicon surfactant of this invention has the following structure:

[0020] ;

[0021] When R is an organosilicon segment:

[0022] .

[0023] When R is an alkane segment:

[0024] .

[0025] Preferably, the two 1,3,5,7-tetramethylcyclotetrasiloxane residues are each derived from one of the 1,3,5,7-tetramethylcyclotetrasiloxane molecules. The site undergoes a hydrosilylation reaction with the di-terminated unsaturated compound, the polyether phosphate monoester salt arm The remaining residues derived from the 1,3,5,7-tetramethylcyclotetrasiloxane residues The site involves the hydrosilylation reaction of unsaturated polyethers, as well as subsequent phosphorylation and neutralization reactions.

[0026] Preferably, the intermediate connecting chain segment When it is an alkane segment, the intermediate connecting segment for:

[0027] ;

[0028] In the formula, The range is 4 to 8;

[0029] Alternatively, the intermediate connecting chain segment When the linker is an organosilicon segment, the intermediate linker segment for:

[0030] ;

[0031] In the formula, The range is 1 to 50.

[0032] Preferably, the polyether phosphate monoester salt arm middle, It is 3. The range is 3 to 8. The range is 0 to 3. The range is 0 to 1. and One of them is The other is , , Triethanolamine cation or diethanolamine cation.

[0033] Preferably, the dumbbell-shaped phosphate ester anionic organosilicon surfactant does not exhibit a wavelength between 2150 and 2180 cm⁻¹ in its infrared spectrum. Characteristic absorption peaks, with a range of 1230–1260 cm⁻¹. Characteristic absorption peaks; the polyether phosphate monoester salt arm The average degree of substitution is 90% to 100% of the theoretical six-arm substitution degree.

[0034] Secondly, the present invention also provides a method for preparing the dumbbell-shaped phosphate ester anionic organosilicon surfactant, comprising the following steps:

[0035] S1. Mix 1 mol of the double-ended unsaturated compound with 1.9–2.1 mol of 1,3,5,7-tetramethylcyclotetrasiloxane, and carry out a first hydrosilylation reaction in the presence of a platinum catalyst, so that the two unsaturated end groups of the double-ended unsaturated compound are respectively attached to one of two 1,3,5,7-tetramethylcyclotetrasiloxane molecules. Site addition yields 5.7–6.3 mol retained per mole. dumbbell-shaped hydrogen-containing cyclosiloxane intermediates ;

[0036] S2, Add 1 mol of the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. A second hydrosilylation reaction is carried out with the unsaturated polyether to form the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. The remaining The site undergoes addition with the unsaturated polyether to obtain a dumbbell-shaped cyclosiloxane carbon alcohol intermediate. ;

[0037] S3. Under inert gas protection, the dumbbell-shaped cyclosiloxane carbon alcohol intermediate is... The dumbbell-shaped phosphate ester salt anionic organosilicon surfactant is obtained by fractional phosphate esterification reaction with phosphorus pentoxide, followed by hydrolysis, neutralization, desulfurization and filtration.

[0038] Preferably, in step S1, the double-ended unsaturated compound is selected from... -Dual-terminated vinyl polydimethylsiloxane, - One or two of the double-ended long-chain olefins; the feeding temperature of the first hydrosilylation reaction is 20-80℃, the reaction temperature is 80-120℃, the reaction time is 1-6h, the reaction endpoint is that the carbon-carbon double bond conversion rate of the double-ended unsaturated compound is not less than 98%, and the low-boiling components are removed for 1-6h under the conditions of 1-1000kPa and 80-120℃ after the reaction.

[0039] Preferably, in step S2, the unsaturated polyether has the following structure:

[0040] ;

[0041] In the formula, Integers between 2 and 4 It is an ethylene oxide structural unit. It is a propylene oxide structural unit. It is an epoxybutane structural unit. The range is 1 to 10. The range is 0 to 10. The range is 0 to 5;

[0042] The amount of the unsaturated polyether added is the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. Remaining The molar amount is 1.02 to 1.20 times the normal amount. The feeding temperature of the second hydrosilylation reaction is 40 to 100°C, the reaction temperature is 80 to 150°C, the reaction time is 2 to 6 hours, and the reaction proceeds to the product. The content is not higher than 0.05 mmol / g.

[0043] Preferably, in step S3, 1 mol of the dumbbell-shaped cyclosiloxane carbon alcohol intermediate is first added. Add 0.1–1 wt% deionized water and mix thoroughly. Then, pre-disperse 1–3 mol of phosphorus pentoxide in mineral oil to form a phosphorus pentoxide dispersion. Add the phosphorus pentoxide dispersion in batches to the dumbbell-shaped cyclosiloxane carbon alcohol intermediate. In the process, the first stage of phosphorylation reaction is carried out at 40–60°C for 1–3 hours, and the second stage of phosphorylation reaction is carried out at 60–80°C for 1–3 hours.

[0044] Preferably, in step S3, after the second stage of phosphoesterification reaction is completed, 1-10 wt% deionized water is added, and hydrolysis is carried out at 50-100°C for 0.5-5 hours. Then, the mixture is neutralized to a final concentration using one or more of sodium hydroxide, potassium hydroxide, ammonia, and organic amines. The content is 7-9, and the low-boiling components are removed under the conditions of 1-1000 kPa and 40-120℃. The dumbbell-shaped phosphate ester salt anionic organosilicon surfactant is obtained by positive pressure filtration. The molar proportion of phosphate monoester salt in the total phosphate ester structure of the obtained product is not less than 60%.

[0045] This invention uses an intermediate connecting chain segment Two 1,3,5,7-tetramethylcyclotetrasiloxane residues were linked into a dumbbell-shaped backbone, and the unlinked residues in each cyclotetrasiloxane residue were utilized. Each of the three silicon atoms is connected to a polyether phosphate monoester salt arm. This results in an average of 5.4–6.0 anionic anchoring arms per molecule. Compared to existing polyether organosilicon phosphates with linear hydrogen-containing silicone oil as the backbone, the phosphate monoester salt groups of this invention are concentrated on the outside of the two cyclic end groups, making them less susceptible to being masked by long siloxane segments. This improves the coordination, hydrogen bonding, or electrostatic adsorption efficiency of the phosphate ester groups with the surfaces of metal oxides, inorganic pigments and fillers, carbon materials, or lithium battery active materials. Simultaneously, the bicyclic tetrasiloxane end groups provide a moderately rigid yet flexible spatial support, and multiple polyether segments extend into the dispersion medium to form a solvation layer, which reduces particle surface energy and enhances interparticle spatial repulsion, thereby reducing secondary particle agglomeration, sedimentation, and slurry viscosity rebound. Furthermore, this invention employs a first hydrosilylation reaction of a bicyclic unsaturated compound with 1,3,5,7-tetramethylcyclotetrasiloxane, followed by the remaining... The modular preparation route of site-specific secondary hydrosilylation of unsaturated polyethers and segmented phosphoesterification allows for controlled backbone construction, polyether arm introduction, and anionization modification, which can improve the uniformity of substitution degree and structural regularity, reduce random phosphorylation side reactions, and produce products with good wetting and spreading ability, anchoring and dispersing ability, and storage stability. Furthermore, the reaction conditions are mild, the raw materials are readily available, and it is easy to scale up industrially. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the molecular configuration of a dumbbell-shaped phosphate ester anionic organosilicon surfactant.

[0047] Figure 2 This is a schematic diagram of the preparation method of the present invention.

[0048] Figure 3 This is a curve showing the endpoint monitoring of the hydrosilylation reaction.

[0049] Figure 4 intermediate intermediates Comparison of infrared spectra with those of the target product.

[0050] Figure 5 The figures show a comparison of particle size distribution before and after standing in the titanium dioxide aqueous dispersion system of the examples and comparative examples.

[0051] Figure 6 This is a comparison graph of viscosity-shear rate curves for the examples and comparative examples of lithium iron phosphate slurry. Detailed Implementation

[0052] The following combination Figures 1-6The present invention will be further illustrated by specific embodiments. It should be understood that the following embodiments are used to illustrate the technical solutions of the present invention, and not to limit the scope of protection; without departing from the concept of the present invention, those skilled in the art can make conventional adjustments to the reaction temperature, feed ratio, depressurization pressure, type of neutralizing agent and polyether segment length according to the raw material supply, equipment conditions and application system.

[0053] I. Raw materials, instruments and testing methods

[0054] The 1,3,5,7-tetramethylcyclotetrasiloxane used in this specific embodiment is an industrial-grade product, obtained through vacuum distillation, with a gas chromatographic purity of not less than 98.5%; the Karstedt platinum catalyst is a divinyltetramethyldisiloxane complex with a platinum content of 3000 ppm; 1,5-hexadiene, vinyl bicapsulated... - The divinyl-terminated polydimethylsiloxane, unsaturated polyether, phosphorus pentoxide, mineral oil, sodium hydroxide, and triethanolamine are all commercially available industrial or analytical grade raw materials.

[0055] like Figure 1 As shown, in this embodiment, the polyether phosphate monoester salt arm The general formula is:

[0056] ;

[0057] In the formula, Integers between 2 and 4; It is an ethylene oxide structural unit; It is a propylene oxide structural unit; It is an epoxybutane structural unit; The range is 1 to 10; The range is 0 to 10; The range is 0 to 5; and Each independently selected , , , Or organic amine cations, and and At least one of them is , , Or organic amine cations.

[0058] Intermediate connecting chain segment It can be an alkane segment or an organosilicon segment. The alkane segment is as follows:

[0059] ;

[0060] The organosilicon segments are:

[0061] ;

[0062] In the formula, The range is 2 to 12. The range is 1 to 100. It indicates methyl.

[0063] During the reaction, the endpoint of the first hydrosilylation was determined using a combination of infrared spectroscopy, iodometric titration, and gas chromatography. The control target for the first step of the reaction was not complete consumption. Instead, it aims to ensure that the carbon-carbon double bond conversion rate of the di-terminated unsaturated compound is not less than 98%, while simultaneously ensuring that the obtained dumbbell-shaped hydrogen-containing cyclosiloxane intermediate... Each mole retains 5.7–6.3 mol. The endpoint of the second hydrosilylation is the product... The content is not higher than 0.05 mmol / g. After the phosphorylation reaction is completed, the phosphorus content is measured by acid value, phosphorus content, infrared spectroscopy, and... 31 The product was confirmed by nuclear magnetic resonance (NMR).

[0064] Infrared spectra were measured using a Fourier transform infrared spectrometer, with a focus on the 2150–2180 cm⁻¹ range. -1 of Characteristic absorption peak, 1230–1260 cm⁻¹ -1 of Characteristic absorption peaks and 1020–1070 cm⁻¹ -1 of or Absorption peaks were observed. Surface tension was determined using the platinum plate method at 25°C, with a sample aqueous solution concentration of 0.1 wt%. The titanium dioxide dispersion experiment used rutile titanium dioxide with a solid content of 50 wt%, and the dispersant dosage was 1.0 wt% of the titanium dioxide mass. In the lithium iron phosphate slurry experiment, lithium iron phosphate, conductive carbon black, binder, and solvent were prepared according to standard laboratory slurry ratios, and the surfactant dosage was 0.6 wt% of the lithium iron phosphate mass. Particle size was determined using a laser particle size analyzer, and viscosity was determined using a rotational rheometer.

[0065] II. Example 1

[0066] This embodiment is used to illustrate the use of 1,5-hexadiene as the intermediate linking segment source and allyl polyether. A method for preparing dumbbell-shaped phosphate ester anionic organosilicon surfactants when the chain segment is a hydrophilic segment.

[0067] like Figure 2As shown, in a 2L dry four-necked flask purged with nitrogen, 1 mol of 1,5-hexadiene and 2.02 mol of 1,3,5,7-tetramethylcyclotetrasiloxane were added. Mechanical stirring was started, and the mixture was stirred at 300 rpm for 30 min at 40 °C. Then, Karstedt platinum catalyst was added to bring the platinum content in the system to 2 ppm. The temperature was slowly increased to 95 °C and maintained at 95–105 °C for 3 h. Samples were taken every 30 min during the reaction. Gas chromatography showed that the residual 1,5-hexadiene was less than 1.2%, and significant 1,5-hexadiene was still visible in the infrared spectrum. The characteristic absorption peaks indicate that the two terminal alkenyl groups have largely participated in hydrosilylation, while the remaining residues on the cyclotetrasiloxane residues... The sites were preserved. After the reaction was complete, the low-boiling components were removed at 100℃ and 20kPa for 2 hours to obtain a colorless and transparent dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. Its viscosity is 8.4 mPa·s, and its average retention per mole, as determined by iodometric titration, is 5.95 mol. .

[0068] 1 mol intermediate The mixture was transferred to another nitrogen-purged, dried reactor, and 6.8 mol of allyl polyether was added. The allyl polyether has the following structure:

[0069] ;

[0070] After adding, heat to 60°C and stir for 40 minutes to make the intermediate... The mixture was thoroughly mixed with allyl polyether. A Karstedt platinum catalyst was added to achieve a platinum content of 4 ppm. The temperature was raised to 105 °C and maintained at 105–120 °C for 4 hours. Infrared spectroscopy showed a range of 2150–2180 cm⁻¹. -1 of The peak basically disappeared, and the result was determined by iodometric titration. The content is 0.028 mmol / g, indicating that the remaining... The site has undergone sufficient addition with the unsaturated polyether. Then, it is de-lowered at 110℃ and 10kPa for 2 hours to remove unreacted polyether and low-boiling-point substances, yielding an amber-colored transparent liquid, namely the dumbbell-shaped cyclosiloxane carbon alcohol intermediate. The viscosity is 860 mPa·s.

[0071] Under nitrogen protection, 1 mol of intermediate Add to the reaction vessel, add deionized water, the amount added is the intermediate. 0.3 wt% of phosphorus pentoxide was stirred evenly at 40°C. Separately, 2.4 mol of phosphorus pentoxide was pre-dispersed in mineral oil to prepare a 50 wt% phosphorus pentoxide dispersion. This dispersion was added in batches to the intermediate over 2 hours. In the process, the first stage of phosphorylation was carried out at a temperature of 45–55 °C for 2 hours; then the temperature was increased to 65–70 °C for a second stage of phosphorylation for 3 hours. After esterification, an intermediate was added. 6 wt% deionized water was hydrolyzed at 80°C for 2 hours, and then slowly neutralized with a 20 wt% sodium hydroxide aqueous solution. The concentration was 7.6. Finally, the concentration was reduced at 100℃ and 15kPa for 2 hours, and then filtered under positive pressure through a 0.45μm filter membrane to obtain a yellow, transparent, viscous liquid, which is a dumbbell-type phosphate ester anionic organosilicon surfactant. .

[0072] Among them, such as Figure 3 As shown, this is a schematic diagram of the reaction endpoint monitoring curves for the first and second hydrosilylation reactions in the embodiment. Figure 4 The intermediate in Example 1 intermediates A schematic diagram comparing the infrared spectra of the target product and the target product.

[0073] The product was tested. Medium polyether phosphate monoester salt arm The average degree of substitution is 96.2% of the theoretical six-arm substitution degree, and the molar proportion of phosphate monoester salts in the total phosphate ester structure is 72.5%. For example... Figure 4 As shown, compared to intermediates intermediate 2150-2180cm -1 of The peak weakened significantly; the target product The peak disappeared in the middle, and a peak of 1241 cm appeared. -1 of absorption peak and 1048 cm^-1 The absorption peak indicates that the polyether phosphate monoester salt arm has been successfully introduced.

[0074] III. Example 2

[0075] This embodiment illustrates the use of vinyl double-ended caps as the intermediate connecting chain source, and the use of... Preparation method when unsaturated polyethers are used as hydrophilic segments.

[0076] Under nitrogen protection, 1 mol of vinyl bicapsulated resin and 2.00 mol of 1,3,5,7-tetramethylcyclotetrasiloxane were added to a 1 L four-necked flask. The mixture was heated to 45 °C, and then Karstedt platinum catalyst was added to achieve a platinum content of 1.5 ppm. The reaction temperature was controlled at 90–100 °C, and the reaction was carried out for 2.5 h. Gas chromatography showed that the residual amount of vinyl bicapsulated resin was less than 1.0%, and the obtained intermediate was determined by iodometric titration. 5.88 mol of each mole are retained. The reaction solution was depressurized at 90℃ and 30kPa for 3 hours to obtain a colorless and transparent liquid. The viscosity is 6.7 mPa·s.

[0077] Then 6.6 mol of unsaturated polyether was added, with the following structure:

[0078] ;

[0079] After thorough mixing at 60°C, Karstedt platinum catalyst was added to achieve a platinum content of 3 ppm. The reaction temperature was controlled at 100–115°C for 3 hours. At the end of the reaction, the product… The content was 0.033 mmol / g. After degradation at 110℃ and 10 kPa for 2 h, a dumbbell-shaped cyclosiloxane carbon alcohol intermediate was obtained. The viscosity is 410 mPa·s.

[0080] 1 mol intermediate Add the mixture to the reactor, add 0.5 wt% deionized water, and stir until homogeneous at 40°C. Disperse 2.0 mol of phosphorus pentoxide in mineral oil and add it to the system in batches, controlling the first esterification temperature at 45–55°C for 2 hours; then raise the temperature to 65–75°C for the second esterification reaction for 2.5 hours. Subsequently, add 5 wt% deionized water and hydrolyze at 80°C for 2 hours, neutralizing with triethanolamine to... The concentration was 7.8. The product was degraded at 100℃ and 20kPa for 2 hours, and then filtered to obtain the target product. .

[0081] product It is a light yellow, transparent, viscous liquid with a viscosity of 1120 mPa·s. Infrared spectroscopy shows... The characteristic peaks disappear and appear and Characteristic absorption. The polyether phosphate monoester salt arm was detected. The average degree of substitution is 94.8% of the theoretical six-arm substitution degree, and the molar proportion of phosphate monoester salt in the total phosphate ester structure is 69.3%.

[0082] IV. Example 3

[0083] This embodiment is used to illustrate... - Preparation method when di-terminated vinyl polydimethylsiloxane is used as the source of intermediate linker segments.

[0084] Add 1 mol to the 3L reactor after nitrogen purging. - A divinyl-terminated polydimethylsiloxane with a number average molecular weight of approximately 1000 was added, followed by 2.08 mol of 1,3,5,7-tetramethylcyclotetrasiloxane. The mixture was heated to 50°C, and a Karstedt platinum catalyst was added to achieve a platinum content of 3 ppm. The reaction was maintained at 100–110°C for 4 hours. At the reaction endpoint, the vinyl conversion rate was 98.6%, and the resulting intermediate... 6.05 mol of each mole are retained. After degradation at 120℃ and 10kPa for 3 hours, a colorless, transparent, slightly viscous liquid was obtained. The viscosity is 24 mPa·s.

[0085] 1 mol intermediate When mixed with 7.2 mol of allyl polyether, the allyl polyether has the following structure:

[0086] ;

[0087] The mixture was stirred at 60°C for 30 min, then Karstedt platinum catalyst was added to achieve a platinum content of 3.5 ppm. The reaction temperature was controlled at 105–120°C for 4 h. At the end of the reaction... The content was 0.030 mmol / g. After de-lowering, an intermediate was obtained. It is a light yellow transparent liquid with a viscosity of 720 mPa·s.

[0088] intermediate Phosphorylation was carried out using deionized water and phosphorus pentoxide dispersion in a similar process to Example 1, but the amount of phosphorus pentoxide was adjusted to 2.2 mol. The first stage of esterification was carried out at 45–55 °C for 2 hours, and the second stage of esterification was carried out at 65–75 °C for 3 hours. After hydrolysis, the solution was neutralized with potassium hydroxide aqueous solution. The concentration was 8.1, and the product was obtained by de-filtration. .product The average six-arm substitution degree is 95.5%, and the molar proportion of phosphate monoester salt in the total phosphate ester structure is 70.8%.

[0089] In this embodiment, due to the intermediate connecting chain segment The product, consisting of organosilicon segments, exhibits better compatibility in low-polarity resins and silicon-containing systems than in Example 1, while still maintaining good water dispersibility and particle anchoring ability. This demonstrates that the structure described in this invention is suitable for various applications. Both can be implemented under the chain segment and achieve essentially the same dumbbell-shaped multi-arm anchoring dispersion effect.

[0090] V. Example 4

[0091] This example illustrates that the target structure and dispersion effect can still be obtained under conditions of shorter polyether chain segments.

[0092] The intermediate was prepared according to the method in Example 1. Then 1 mol of intermediate was added. It reacts with 7.5 mol of unsaturated polyether, the structure of which is:

[0093] ;

[0094] The second hydrosilylation reaction was carried out at 100–115 °C for 3 hours, with the endpoint... The content was 0.040 mmol / g, and the intermediate was obtained. Subsequently, fractional phosphorylation was carried out using 2.3 mol of phosphorus pentoxide. The first stage was carried out at 45–55 °C for 2 h, and the second stage was carried out at 65–70 °C for 2 h. After hydrolysis, the mixture was neutralized with sodium hydroxide. The concentration was 7.5, and the target product was obtained by de-filtration. .

[0095] product The average degree of six-arm substitution was 93.7%, and the proportion of phosphate monoester salt was 66.9%. Compared with Example 1, the product... Although the polyether segments are relatively short and the water solubility is slightly lower, it still exhibits significantly better dispersion stability than linear polyether organosilicon phosphates in the titanium dioxide and alumina system, indicating that the bicyclic end-group six-arm site-fixed structure of the present invention has a dominant contribution to the dispersion performance.

[0096] VI. Example 5

[0097] This embodiment is used to illustrate the use of higher... Dumbbell-shaped phosphate ester anionic organosilicon surfactants suitable for organic phases or aqueous composite systems are prepared by using polyether segments.

[0098] The intermediate was prepared according to Example 2. 1 mol of intermediate When mixed with 7.0 mol of unsaturated polyether, the unsaturated polyether has the following structure:

[0099] ;

[0100] The reaction was carried out at 105–125 °C for 4 h in the presence of Karstedt platinum catalyst, with the endpoint... The content was 0.036 mmol / g, and the intermediate was obtained by de-lowering. Intermediate The phosphoric acid was fractionally esterified with 2.1 mol of phosphorus pentoxide, followed by hydrolysis and neutralization with triethanolamine. The product was obtained after de-filtration at a concentration of 8.0. .

[0101] product The average degree of six-arm substitution was 94.1%, and the proportion of phosphate monoester salts was 68.5%. Due to... High chain segment content, product It exhibits good wetting and compatibility properties in dispersion systems containing certain organic solvents or resin components, and is suitable for coatings, inks and composite slurry systems.

[0102] VII. Comparative Example 1

[0103] This comparative example is a linear polyether organosilicon phosphate, used to illustrate the improvement effect of the dumbbell-shaped six-arm fixed-point structure of the present invention compared with conventional linear organosilicon phosphate.

[0104] Low-hydrogen silicone oil and allyl polyether were mixed according to... A linear polyether-modified organosilicon intermediate was prepared by mixing with vinyl in a molar ratio of 1:1.1 and reacting at 105–115 °C for 4 h in the presence of a Karstedt platinum catalyst. Subsequently, phosphorylation, hydrolysis, and neutralization with sodium hydroxide were carried out using phosphorus pentoxide to obtain the linear polyether organosilicon phosphate ester. The proportion The reaction endpoint and phosphate esterification process are basically the same as in Example 1, but its organosilicon skeleton is a linear structure, and the phosphate ester groups are randomly distributed along the molecular chain, without the six-arm site-accumulated structure on the two cyclic end groups.

[0105] 8. Comparative Example 2

[0106] This comparative example is a dumbbell-shaped polyether silicone that has not undergone phosphate esterification, used to illustrate the contribution of phosphate monoester salt groups to the particle anchoring effect.

[0107] The intermediate was prepared according to the method in Example 1. and intermediates However, without performing the phosphorus pentoxide phosphate esterification, hydrolysis, and neutralization in step S3, the intermediate is directly... As a comparative product This comparative example has a dumbbell-shaped bicyclic structure and polyether segments, but does not contain phosphate monoester salt anionic anchoring groups.

[0108] IX. Comparative Example 3

[0109] This comparative example is a non-silicone polyether phosphate ester, used to illustrate the contribution of the organosilicon bicyclic framework to low surface tension and steric hindrance.

[0110] Allyl polyether was directly phosphorylated with phosphorus pentoxide, hydrolyzed, and neutralized with sodium hydroxide to obtain polyether phosphate salt. The product contains a phosphate monoester salt anchoring group, but does not contain an organosilicon cyclic framework, nor does it have a dumbbell-shaped spatial structure.

[0111] 10. Comparative Example 4

[0112] This comparative example is a directly phosphorylated silanol silicone oil system, used to illustrate the difference between the random phosphorylation structure and the site-fixed six-arm structure of the present invention.

[0113] Hydroxyl-terminated polydimethylsiloxane was reacted with phosphorus pentoxide at 120–140 °C, followed by hydrolysis and neutralization to obtain silicic phosphate ester. The phosphate esterification sites in this product preparation route are uncontrollable, the product viscosity fluctuates greatly, and it is prone to turbidity and coagulation in aqueous dispersion systems.

[0114] XI. Comparative Example 5

[0115] This comparative example is a dumbbell-shaped structure with insufficient substitution of the polyether arms, used to illustrate the effect of the degree of substitution of the six arms on the technical performance.

[0116] The intermediate was prepared according to Example 1. However, during the second hydrosilylation, only 3.8 mol of allyl polyether was added to obtain a partially substituted dumbbell-shaped cyclosiloxane carbonol, which was then subjected to phosphorylation, hydrolysis, and neutralization to obtain the comparative product. Upon testing, the product... The average number of polyether phosphate monoester salt arms is approximately 3.7 per molecule, which is lower than 5.4–6.0 per molecule.

[0117] XII. Structural Confirmation Results

[0118] The results of confirming the main structures of Examples 1-5 and the comparative examples are shown in Table 1.

[0119] Table 1. Results of Product Structure Confirmation

[0120]

[0121] As shown in Table 1, Examples 1 through 5 all yielded [goods / goods]. The target product, with complete basic reaction, clear phosphate ester characteristic peaks, and an average number of polyether phosphate monoester salt arms in the range of 5.4 to 6.0, indicates that the present invention can achieve the preparation of a well-structured dumbbell-shaped six-armed phosphate ester anionic organosilicon surfactant through two-step hydrosilylation and segmented phosphate esterification.

[0122] XIII. Surface Tension and Wetting Properties Test

[0123] Examples 1-5 and Comparative Examples 1-5 were prepared into 0.1 wt% aqueous solutions, and their surface tension was measured at 25°C. The spreading diameter was also measured on the surfaces of glass slides and pressed alumina sheets. The results are shown in Table 2.

[0124] Table 2 Surface tension and wetting and spreading properties

[0125]

[0126] As shown in Table 2, the surface tension of the aqueous solutions in Examples 1-5 is all below 24 mN / m, indicating that the bicyclic tetrasiloxane end group can significantly reduce the surface tension of the system. Meanwhile, the spreading diameter of the examples on the alumina sheet surface is significantly higher than that of Comparative Examples 1 and 2, indicating that neither linear organosilicon phosphate esters nor nonionic dumbbell polyether structures alone can simultaneously achieve low surface tension and strong polar surface wetting. In this invention, the phosphate monoester salt arm... It has an anchoring effect on polar surfaces, and the bicyclic siloxane end groups provide low surface energy and spatial support, which synergistically improve the wetting and spreading effect.

[0127] XIV. Water Dispersion Stability Test of Titanium Dioxide

[0128] 50 wt% rutile titanium dioxide, 1.0 wt% dispersant and deionized water were added to a sand mill jar, and zirconia beads were used as the grinding medium. The mixture was sand milled for 60 min under the same grinding conditions, and the initial particle size was measured. The slurry was then sealed and allowed to stand for 30 days, and the particle size and sedimentation rate were measured again. Figure 5 The changes in particle size distribution of some samples before and after standing are shown in Table 3.

[0129] Table 3. Particle size and storage stability of titanium dioxide aqueous dispersion system

[0130]

[0131] As shown in Table 3, Examples 1 through 5 all achieved smaller initial particle sizes and lower 30-day particle size growth rates. Among them, Example 1... With a growth rate of only 8.6% and a sedimentation rate of only 3.2%, it is significantly better than linear polyether organosilicon phosphates. Comparative Example 2, although possessing a dumbbell-shaped polyether silicone structure, lacks phosphate monoester salt groups, resulting in poor initial dispersed particle size and static stability. This indicates that phosphate monoester salt groups are crucial for improving the anchoring and adsorption of inorganic particles. Comparative Example 5 exhibits a partial dumbbell-shaped structure, but the average number of arms is insufficient, demonstrating that when the number of polyether phosphate monoester salt arms is below the range defined in this invention, multi-point anchoring and steric hindrance effects significantly decrease.

[0132] Combination Figure 5 It can be seen that the particle size distribution curve of the embodiment of the present invention changes little after standing for 30 days, while comparative examples 1, 2 and 5 all show large particle size tails, indicating that the six-arm fixed-point distribution structure of the present invention can effectively suppress secondary particle agglomeration.

[0133] XV. Rheological property testing of lithium iron phosphate slurry

[0134] The examples and comparative examples were used for dispersion tests of lithium iron phosphate slurry. The slurry contained 60 wt% lithium iron phosphate, 3 wt% conductive carbon black, 3 wt% binder, and the remainder was solvent; the amount of dispersant was 0.6 wt% based on the mass of lithium iron phosphate. Slurries were prepared under the same high-speed dispersion and ball milling conditions, and the viscosity at different shear rates was measured using a rotational rheometer. Figure 6 Table 4 lists the key data for representative viscosity-shear rate curves.

[0135] Table 4 Viscosity and Storage Stability of Lithium Iron Phosphate Slurry

[0136]

[0137] From Table 4 and Figure 6 It can be seen that Examples 1-5 can significantly reduce the viscosity of lithium iron phosphate slurry and maintain a low viscosity growth rate after 7 days of storage. This result demonstrates that the polyether monophosphate salt arm of the present invention… It can form multi-point anchoring on the surface of polar particles such as lithium iron phosphate, while the bicyclic tetrasiloxane structure and polyether segments together form a steric hindrance layer, allowing the particles to maintain good flowability in high-solids systems. Although Comparative Example 1 contains a polyether organosilicon phosphate structure, the phosphate groups are randomly distributed along the linear chain, making it easier for the molecules to spread evenly on the particle surface after adsorption, making it difficult to form a steric repulsion layer of sufficient thickness. Comparative Example 3 has phosphate anchoring groups but lacks a low surface energy organosilicon framework, resulting in insufficient wetting and viscosity reduction effects. Comparative Example 5 demonstrates that insufficient six-arm substitution significantly reduces dispersion stability.

[0138] XVI. Adsorption Capacity and Elution Resistance Tests

[0139] To further illustrate the multi-point anchoring effect of the present invention, Examples 1, 1, 2, and 3 were used for alumina powder adsorption experiments. Alumina powder was added to an aqueous dispersant solution, stirred for 2 hours, and then centrifuged. The residual organic phosphorus or total organic carbon content in the supernatant was measured, and the adsorption capacity per unit mass of alumina was calculated. Subsequently, the powder was washed three times with deionized water, and the retention rate after elution was measured. The results are shown in Table 5.

[0140] Table 5. Adsorption capacity and elution retention rate of alumina surface

[0141]

[0142] As shown in Table 5, the adsorption capacity and retention rate after elution of Example 1 on the alumina surface were significantly higher than those of the comparative example. This result indicates that the present invention does not simply splice together organosilicon segments, polyether segments, and phosphate groups, but rather achieves this by using the site-specific distribution of six polyether phosphate monoester salt arms on two cyclic end groups, enabling individual molecules to form multi-point bonds on the particle surface, thereby improving adsorption stability and elution resistance.

[0143] As can be seen from the above embodiments, the present invention achieves the target product through the following technical route: First, a bi-terminated unsaturated compound is selectively hydrosilylated with 1,3,5,7-tetramethylcyclotetrasiloxane to construct two cyclotetrasiloxane end groups connected by an intermediate linking segment. Connected dumbbell-shaped hydrogen-containing cyclosiloxane intermediates Then use intermediates The six that are retained in China The site undergoes a second hydrosilylation reaction with the unsaturated polyether to obtain an intermediate with six polyether hydroxyl arms. Finally, through segmental phosphorylation, hydrolysis, and neutralization with phosphorus pentoxide, the hydroxyl termini of the polyether are converted into polyether phosphate monoester salt arms. A dumbbell-shaped phosphate ester anionic organosilicon surfactant was obtained.

[0144] Compared to linear polyether organosilicon phosphates, the difference in this invention lies not in simply introducing phosphate salt groups, but in the targeted arrangement of phosphate salt anchoring groups on the outside of two cyclic tetrasiloxane end groups via polyether segments, resulting in an average of 5.4–6.0 polyether phosphate monoester salt arms per molecule. This structure improves the spatial accessibility of the anchoring groups, preventing randomly distributed phosphate groups from being obscured by siloxane segments. Simultaneously, the two cyclic siloxane end groups provide node-like spatial support, allowing multiple polyether segments to extend into the medium, which is beneficial for forming a thicker solvation layer and steric repulsion layer. Therefore, this invention exhibits lower particle size growth rate, lower sedimentation rate, and lower slurry viscosity in polar inorganic particulate systems such as titanium dioxide, alumina, and lithium iron phosphate.

[0145] From a feasibility perspective, all steps of this invention are completed using raw materials and conventional reaction equipment readily available in the art. The reaction endpoint can be determined by infrared spectroscopy, iodometric titration, acid value, phosphorus content, and... 31 Confirmed using conventional detection methods such as NMR. The first hydrosilylation reaction controlled the transformation of the bi-terminated unsaturated compound while retaining the residual... Second hydrosilylation control Basic consumption, segmented phosphorylation controls the proportion of phosphate monoester salts and the degree of side reactions, the logic between each step is clear, the conditions are mild, and it is suitable for laboratory pilot-scale and industrial scale-up.

[0146] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A dumbbell-shaped phosphate ester anionic organosilicon surfactant, characterized in that, The dumbbell-shaped phosphate salt anionic organosilicon surfactant consists of two 1,3,5,7-tetramethylcyclotetrasiloxane residues and an intermediate linking segment between them. Forming a dumbbell-shaped framework, the two 1,3,5,7-tetramethylcyclotetrasiloxane residues are connected by a silicon atom via... The key is connected to the intermediate connecting chain segment. At both ends, each of the 1,3,5,7-tetramethylcyclotetrasiloxane residues did not participate in connecting the intermediate linker segment. The three silicon atoms were respectively processed by A polyether phosphate monoester salt arm is linked by a bond. This results in an average of 5.4–6.0 polyether phosphate monoester salt arms per molecule. ; Among them, the polyether phosphate monoester salt arm It has the following structure: In the formula, Integers between 2 and 4; It is an ethylene oxide structural unit. It is a propylene oxide structural unit. It is an epoxybutane structural unit; The range is 1 to 10. The range is 0 to 10. The range is 0 to 5; and Each independently selected , , , Or organic amine cations, and and At least one of them is , , Or organic amine cations; The intermediate connecting chain segment The segments are alkane segments or organosilicon segments, wherein the alkane segments are: ； The organosilicon segments are: ； In the formula, The range is 2 to 12. The range is 1 to 100. It indicates a methyl group.

2. The dumbbell-shaped phosphate ester anionic organosilicon surfactant according to claim 1, characterized in that, The two 1,3,5,7-tetramethylcyclotetrasiloxane residues are each derived from one of the 1,3,5,7-tetramethylcyclotetrasiloxane molecules. The site undergoes a hydrosilylation reaction with the di-terminated unsaturated compound, the polyether phosphate monoester salt arm The remaining residues derived from the 1,3,5,7-tetramethylcyclotetrasiloxane residues The site involves the hydrosilylation reaction of unsaturated polyethers, as well as subsequent phosphorylation and neutralization reactions.

3. The dumbbell-shaped phosphate ester anionic organosilicon surfactant according to claim 1, characterized in that, The intermediate connecting chain segment When it is an alkane segment, the intermediate connecting segment for: ； In the formula, The value is 4 to 8; or, the intermediate connecting chain segment When the linker is an organosilicon segment, the intermediate connecting segment for: ； In the formula, The range is 1 to 50.

4. The dumbbell-shaped phosphate ester anionic organosilicon surfactant according to claim 1, characterized in that, The polyether phosphate monoester salt arm middle, It is 3. The range is 3 to 8. The range is 0 to 3. The range is 0 to 1. and One of them is The other is , , Triethanolamine cation or diethanolamine cation.

5. The dumbbell-shaped phosphate ester anionic organosilicon surfactant according to claim 1, characterized in that, The dumbbell-shaped phosphate ester anionic organosilicon surfactant does not exhibit an infrared spectrum in the 2150–2180 cm⁻¹ range. Characteristic absorption peaks, with a range of 1230–1260 cm⁻¹. Characteristic absorption peaks; the polyether phosphate monoester salt arm The average degree of substitution is 90% to 100% of the theoretical six-arm substitution degree.

6. A method for preparing the dumbbell-shaped phosphate ester anionic organosilicon surfactant according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Mix 1 mol of the double-ended unsaturated compound with 1.9–2.1 mol of 1,3,5,7-tetramethylcyclotetrasiloxane, and carry out a first hydrosilylation reaction in the presence of a platinum catalyst, so that the two unsaturated end groups of the double-ended unsaturated compound are respectively attached to one of two 1,3,5,7-tetramethylcyclotetrasiloxane molecules. Site addition yields 5.7–6.3 mol retained per mole. dumbbell-shaped hydrogen-containing cyclosiloxane intermediates ; S2, Add 1 mol of the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. A second hydrosilylation reaction is carried out with the unsaturated polyether to form the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. The remaining The site undergoes addition with the unsaturated polyether to obtain a dumbbell-shaped cyclosiloxane carbon alcohol intermediate. ; S3. Under inert gas protection, the dumbbell-shaped cyclosiloxane carbon alcohol intermediate is... The dumbbell-shaped phosphate ester salt anionic organosilicon surfactant is obtained by fractional phosphate esterification reaction with phosphorus pentoxide, followed by hydrolysis, neutralization, desulfurization and filtration.

7. The method according to claim 6, characterized in that, In step S1, the double-ended unsaturated compound is selected from... -Dual-terminated vinyl polydimethylsiloxane, - One or two of the double-ended long-chain olefins; the feeding temperature of the first hydrosilylation reaction is 20-80℃, the reaction temperature is 80-120℃, the reaction time is 1-6h, the reaction endpoint is that the carbon-carbon double bond conversion rate of the double-ended unsaturated compound is not less than 98%, and the low-boiling components are removed for 1-6h under the conditions of 1-1000kPa and 80-120℃ after the reaction.

8. The method according to claim 6, characterized in that, In step S2, the unsaturated polyether has the following structure: In the formula, Integers between 2 and 4 It is an ethylene oxide structural unit. It is a propylene oxide structural unit. It is an epoxybutane structural unit. The range is 1 to 10. The range is 0 to 10. The range is 0 to 5; The amount of the unsaturated polyether added is the dumbbell-shaped hydrogen-containing cyclosiloxane intermediate. Remaining The molar amount is 1.02 to 1.20 times the normal amount. The feeding temperature of the second hydrosilylation reaction is 40 to 100°C, the reaction temperature is 80 to 150°C, the reaction time is 2 to 6 hours, and the reaction proceeds to the product. The content is not higher than 0.05 mmol / g.

9. The method according to claim 6, characterized in that, In step S3, 1 mol of the dumbbell-shaped cyclosiloxane carbon alcohol intermediate is first added. Add 0.1–1 wt% deionized water and mix thoroughly. Then, pre-disperse 1–3 mol of phosphorus pentoxide in mineral oil to form a phosphorus pentoxide dispersion. Add the phosphorus pentoxide dispersion in batches to the dumbbell-shaped cyclosiloxane carbon alcohol intermediate. In the process, the first stage of phosphorylation reaction is carried out at 40–60°C for 1–3 hours, and the second stage of phosphorylation reaction is carried out at 60–80°C for 1–3 hours.

10. The method according to claim 9, characterized in that, In step S3, after the second stage of phosphorylation reaction is completed, 1-10 wt% deionized water is added, and hydrolysis is carried out at 50-100°C for 0.5-5 hours. Then, the mixture is neutralized with one or more of sodium hydroxide, potassium hydroxide, ammonia, and organic amines. The content is 7-9, and the low-boiling components are removed under the conditions of 1-1000 kPa and 40-120℃. The dumbbell-shaped phosphate ester salt anionic organosilicon surfactant is obtained by positive pressure filtration. The molar proportion of phosphate monoester salt in the total phosphate ester structure of the obtained product is not less than 60%.

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