CN111992156A

CN111992156A - Continuous synthesis method and application of sulfonated ketone-aldehyde condensation compound

Info

Publication number: CN111992156A
Application number: CN202010878756.1A
Authority: CN
Inventors: 姚型军; 姜松; 舒东博
Original assignee: Liaocheng University
Current assignee: Liaocheng University
Priority date: 2020-08-27
Filing date: 2020-08-27
Publication date: 2020-11-27

Abstract

The invention provides a continuous synthesis method and application of a sulfonated ketoaldehyde condensation compound, belonging to the technical field of preparation of high molecular compounds. The invention effectively overcomes the problems of inaccurate temperature control, long reaction time, easy generation of byproducts of reaction mixture and incapability of continuous production in the process of synthesizing SAF due to strong heat release in the reaction process by using the microstructure reactor for preparing the SAF, and really realizes the continuous synthesis of the SAF, thereby having good practical popularization and application values.

Description

Continuous synthesis method and application of sulfonated ketone-aldehyde condensation compound

Technical Field

The invention belongs to the technical field of preparation of high molecular compounds, and relates to a continuous synthesis method and application of a sulfonated ketoaldehyde condensation compound.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The aliphatic water reducing agent is a high molecular water reducing agent with surface activity, which is prepared by taking aldehyde and ketone carbonyl compounds as main raw materials, condensing under an alkaline condition to obtain an aliphatic macromolecular chain, and introducing hydrophilic sulfonic acid groups on the molecular chain through the addition of sulfite. The most representative is sulfonated acetone-formaldehyde condensate (SAF) prepared by using formaldehyde and acetone as raw materials and sodium sulfite and sodium bisulfite as sulfonating agents, which is an aliphatic sulfonate high-efficiency water reducing agent with the molecular weight of 4000-10000. The high-temperature dispersion drag reducer is used as a high-temperature dispersion drag reducer for cement in deep well cementing operation, has higher water reducing rate, can obviously improve the rheological property of the cement, reduces the time loss of fresh cement slurry, ensures that the cement slurry has good workability, has obvious reinforcing effect and good high-temperature resistance and salt resistance, is suitable for the cementing operation of deep wells, ultra-deep wells and saline wells, and quickly replaces a naphthalene sulfonate water reducer (Zhang Xin, the research on the synthesis and modification of SAF [ D ]. Jinan: Jinan university, 2012) in the drilling industry. The SAF water reducing agent can reduce the surface tension of water and is a novel water reducing agent with air entraining function. As a concrete high-efficiency water reducing agent, the concrete high-efficiency water reducing agent has no air entrainment, no retardation and small slump loss, is particularly suitable for being used under the condition of higher temperature, and is a high-efficiency water reducing agent with promising development prospect (EP0163459, DE3429068, CN 1066448A). The raw materials are easy to obtain, the production process is simple, the water reducing effect is excellent, and the like, so that the method is widely applied to various projects. The production process of the aliphatic sulfonate water reducer has no three-waste discharge, and the production and use processes have no pollution to the environment, so that the aliphatic sulfonate water reducer has better cost performance compared with a naphthalene high-efficiency water reducer, thereby causing wide attention of additive manufacturers and use units and accelerating the research on the production process and application performance of the additive. At present, there are two methods for synthesizing sulfonated acetone-formaldehyde polycondensate, one is to drop acetone into 45 ℃ sodium sulfite aqueous solution, mechanically stir for 20min until the solution becomes clear, then continue to drop 37% formaldehyde aqueous solution, and control the reaction temperature below 65 ℃. After the dropwise addition, heating the reaction system to 80-85 ℃. And (3) reacting for 3h, finishing the reaction, cooling the reaction liquid to room temperature, wherein the final pH is higher than 11, and the solid content of the obtained product is 35%. The formaldehyde dropping amount in the reaction process is controlled, the SAF molecular weight is controlled, the consumption of sodium sulfite is controlled to control the content of sulfonic acid groups, the molecular weight of the product is 2.08-3.18 ten thousand, and PDI is 1.16-1.59. (R.Li et al. energy Conversion and Management, 64(2012) 139-144; Hongming Lou et al, center and Concrete Research 42(2012) 1043-1048); zhongminsong et al, fine chemical, 2005, 22 (3): 18-188).

In another method for preparing SAF, acetone, formaldehyde and sodium sulfite are added into a reaction bottle according to the proportion that acetone, formaldehyde and sodium sulfite are added into the reaction bottle, the condensation polymerization reaction is carried out under the action of strong alkali, and the reaction is controlled by controlling the adding speed of alkali liquor. The concentration of alkali in the initial reaction mixture is low, the reaction speed is slow, when the concentration of alkali exceeds a certain value, the reaction speed is obviously accelerated, the reaction heat is difficult to disperse in time, the temperature in a reaction object is rapidly increased, so that the raw materials are seriously volatilized, the material flushing phenomenon is easy to occur, and the quality of the product is difficult to control.

In experimental studies on the synthesis method, different charging sequences have great influence on the synthesis reaction and the dispersion performance of the sulfonated polycondensate, which indicates that the charging methods are different and the reaction mechanisms are different. If the sulfite is prepared into solution with proper concentration, acetone is added at normal temperature, and after reaction for a period of time at low temperature, the formaldehyde solution is added dropwise, the reaction temperature is easy to control, and the obtained sulfonated polycondensate has good dispersion performance. Possible reaction mechanisms are nucleophilic addition reactions of the sulfonating agent with acetone, again cross aldol condensation reactions of acetone with formaldehyde, and finally polycondensation reactions of the sulfonation product and the condensation product:

a) adding acetone into a sulfite solution to generate alpha-hydroxy sulfonate, wherein the reaction is reversible:

after reacting for a period of time, formaldehyde is dripped in, and acetone and aldehyde are subjected to cross aldol condensation reaction in an alkaline medium due to excessive acetone in the reaction system to generate dimethylol acetone.

As the reaction time was extended, the concentration of dimethylol acetone in the solution increased; (ii) a Due to the exothermic reaction, the temperature increased and a dehydration reaction occurred between dimethylol acetone to form a polycondensate.

The polymerization degree of the dimethylol acetone polycondensate is a key factor influencing the SAF performance; the degree of polymerization is too small, the dispersibility is poor, the degree of polymerization is too large, the water solubility is poor, and the SAF with good water solubility and dispersibility can be obtained by controlling the polymerization process. The method of adding acetone and sulfite for reaction is adopted to ensure that the solution has enough hydroxy sulfonate, and the hydroxy sulfonate is monofunctional for polycondensation, so that the chain growth reaction can be stopped once the hydroxy sulfonate reacts with dimethylol acetone; by adopting the mode of dripping formaldehyde, the average polymerization degree of the dimethylol acetone can be effectively controlled, the cross-linking reaction caused by the generation of the poly-hydroxymethyl acetone can be effectively prevented, and the generation of gel precipitate is avoided. If acetone and formaldehyde are added into the sulfite solution together, because the generation of alpha-hydroxy sulfonate is reversible (reactions (1) - (3)), a large amount of acetone and formaldehyde generate cross aldol condensation reaction (4)), because the polycondensation reaction rate is high, the reaction heat is difficult to be removed in time, the reaction temperature is increased rapidly, and the material flushing accident is easy to occur; meanwhile, the produced dimethylol acetone rapidly undergoes dehydration reaction to produce a polycondensate (reaction (5)), resulting in an excessively large average degree of polymerization of the polycondensate and a decrease in water solubility and dispersibility. In addition, due to the presence of large amounts of formaldehyde, polyhydroxymethyl acetone is readily formed, and crosslinking between fatty chains leads to gel precipitation (Poncirus et al, proceedings of the university of Wuhan Arbitrary, 2002, 24 (6): 15-17).

The inventor finds that the methods for synthesizing the SAF are all batch operation, and the feeding process adopts a mode of dropwise feeding to prevent local overheating of the reaction. Inaccurate temperature control, long reaction time, low raw material utilization rate and complicated operation process. A method for continuously synthesizing SAF has not been reported so far.

Disclosure of Invention

The invention provides a continuous synthesis method of a sulfonated ketone-aldehyde condensation polymer (such as a sulfonated acetone-formaldehyde condensation polymer) and application thereof, aiming at the problems of inaccurate temperature control, long reaction time, easy generation of byproducts in a reaction process, incapability of continuous production and the like caused by strong heat release in the synthesis process of the sulfonated acetone-formaldehyde condensation polymer in the prior art.

In order to achieve the purpose, the invention relates to the following technical scheme:

in a first aspect of the invention, there is provided the use of a continuous reactor for the continuous synthesis of sulfonated keto-aldehyde condensates.

Wherein the continuous reactor is a micro-structured reactor; according to the invention, researches show that the sulfonated ketoaldehyde polycondensate (such as SAF) is synthesized in the microstructure reactor, the temperature can be accurately controlled, the accumulation of heat released in the subsequent polycondensation reaction is effectively reduced, the problems of serious volatilization of raw materials and too fast polymerization to form a colloid caused by overheating of a reaction system are avoided, and the solid content in the reaction can reach more than 52%. Meanwhile, sulfonation polymerization in the microstructure reactor can be completed within millisecond, the improvement effect of the difference of reaction kinetics on the selectivity of reactants is obviously enhanced, and the size, distribution and solid content of the molecular weight of the SAF can be conveniently controlled only by regulating and controlling the proportion and temperature of the reactants.

It should be noted that like the micro-structure reactor, the all mixed flow reactor and the tubular reactor are also continuous reactors, which can control the reaction time, improve the reaction efficiency and improve the selectivity of reactants to different degrees, so the application of the continuous reactor in the continuous synthesis of sulfonated ketone-aldehyde polycondensate (such as SAF) is also within the scope of the present application.

In a second aspect of the present invention, there is provided a method for continuously synthesizing a sulfonated ketone-aldehyde condensate, the method comprising: the sulfonated ketone-aldehyde condensate is continuously synthesized in a continuous reactor based on the ketone sulfonation method.

As in the synthesis of SAF, the effect of the microstructured reactor is best in a continuous reactor, since sulfonated acetone is condensed directly with dihydroxyacetone in short of forming large particle precipitates. It should be noted that, in the research, the invention also performs experiments on other fatty aldehyde preparation methods, but other process flows are longer, the operation process links are more, and the product yield is not stable.

Specifically, the method comprises the following steps:

the sulfonating agent and the ketone compound react in a continuous reactor to obtain sulfonated ketone compound solution;

and (3) reacting the sulfonated ketone compound solution with the aldehyde compound solution in a continuous reactor under an alkaline condition, and purifying a reaction product to obtain a sulfonated ketone-aldehyde condensation product.

The purification step comprises neutralization, (rotary evaporation) drying, (ethanol) crystallization, secondary drying and grinding.

Wherein the continuous reactor is a micro-structure reactor, a full mixed flow reactor or a tubular reactor; preferably a microstructured reactor.

Preferably, the molar ratio of the sulfonating agent to the ketone compound is 1: 0.1 to 5; more preferably 1: 0.5 to 5;

preferably, the reaction conditions of the sulfonating agent and the ketone compound in the continuous reactor are as follows: the temperature is 10-60 ℃, and the retention time is 0.1-600 s; more preferably: the temperature is 10-50 ℃, and the retention time is 0.5-600 s.

Wherein, the sulfonating agent comprises but is not limited to sodium lignosulfonate, sodium sulfite, sodium pyrosulfite, sodium imidazolyl-containing sulfonate, thiazolyl sodium sulfonate, pyridyl sodium sulfonate, aryl sodium sulfonate, substituted naphthalene sodium sulfonate and fatty sodium sulfonate solution;

the ketone compounds include, but are not limited to, aromatic ketones, aromatic polyketones, aliphatic ketones, or aliphatic polyketones, such as acetone, butanone, methyl ethyl ketone, acetophenone, and the like.

The molar ratio of the sulfonated ketone to the aldehydes is (0.8-4): 1.

the aldehyde compounds include, but are not limited to, aliphatic aldehydes, aliphatic polyaldehydes, aromatic aldehydes, or aromatic polyaldehydes; such as formaldehyde, acetaldehyde, and the like.

Preferably, the microstructure reactor comprises a micro mixer and a micro channel reactor which are connected in sequence, and further preferably, the microstructure reactor is placed in a constant temperature water bath.

Adding alkali liquor to form an alkaline environment, wherein the pH value of the alkaline environment is 7-12;

preferably, the solvent used for dissolving the sulfonating agent and the solid base is water; the mass ratio of water to sodium hydroxide is 1-8: 1; in particular, when the mass ratio is 6: at 1, the solid content of the reactant is increased by about 5.3 percent.

Preferably, the microstructure reactor material may be stainless steel, glass, quartz, ceramic, polytetrafluoroethylene, inorganic silicon or Peek material;

preferably, the size of the channel of the micro-structure reactor is 0.1 mu m-10 mm;

preferably, the microstructure reactor is of a tubular structure.

In a third aspect of the present invention, there is provided a preferred continuous reaction process for preparing a sulfonated acetone-formaldehyde condensate, comprising:

s1, mixing liquid raw materials of sodium sulfite and acetone according to the molar ratio of the sodium sulfite to the acetone of 1: (2-5) respectively injecting the mixture into a full mixed flow reactor, a tubular reactor or a micro-structure reactor which are connected in series by a pump at the same time, and reacting at the reaction temperature of 20-50 ℃ for 0.1-600 s to obtain a sulfonated acetone solution;

s2, mixing the reaction product sulfonated acetone solution in the step S1 with a formaldehyde water solution according to the molar ratio of sulfonated acetone to formaldehyde being (0.8-4): 1, injecting the mixture into another full mixed flow reactor, a tubular reactor or a micro-structure reactor, controlling the pH value to be 7-12, and reacting under the conditions that the reaction temperature is controlled to be 20-50 ℃ and the retention time is 0.5-600 s; and drying the reactant by rotary evaporation, precipitating crystals by ethanol, drying and grinding to obtain the SAF product.

Adding alkali liquor to form an alkaline condition, wherein the alkali can be sodium hydroxide, sodium phosphate, sodium acetate, sodium carbonate or alkaline ionic liquid; preferably an aqueous sodium hydroxide solution; the mass ratio of water to sodium hydroxide is 1-8: 1; preferably 5-6: 1.

preferably, the micro-structure reactor is a micro mixer or is formed by connecting a micro mixer and a micro-channel reactor.

The diameter of the tubular reactor is 10-100 mm, and the length of the tubular reactor is 5-15 m.

The channel size of the micro mixer and the micro channel reactor is 0.2-8 mm, and the length of the micro channel reactor is 0.5-20 m.

In a third aspect of the present invention, there is provided a sulfonated keto-aldehyde condensate prepared by any one of the above-mentioned methods; preferably, the sulfonated ketone-aldehyde condensate is a sulfonated acetone-formaldehyde condensate.

In a fourth aspect of the invention, there is provided the use of a sulfonated keto-aldehyde condensate as described above in any one or more of:

1) a dispersant;

2) a water reducing agent.

The one or more technical solutions have the beneficial technical effects that:

(1) the technical scheme provides a process method for preparing sulfonated ketone-aldehyde condensation compound, in particular to SAF (safety and safety improvement) by utilizing a continuous reactor, and the method solves the problems that in a conventional kettle-type reactor, because the reaction time is too long, the temperature control is inaccurate, sulfonated acetone is unstable and is easy to generate precipitation reaction, the acetone is easy to volatilize, and the solid content of the product is low;

(2) the technical scheme solves the problem of unsafe production process caused by local hot spots in the reaction process, realizes the continuous safe production of the SAF and is convenient to operate. The SAF is obtained by carrying out rotary evaporation drying, ethanol precipitation and grinding on the reaction mixture.

(3) The preparation method in the technical scheme is simple, efficient, high in practicability and easy to popularize.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a schematic flow diagram of an apparatus for preparing SAF using a microstructured reactor according to an embodiment of the present invention;

wherein, A1, A2 and A3 are liquid chromatography pumps, B1 and B2 are micromixers, C1 and C2 are microchannel reactors, D1 and D2 microstructure reactors, E1 and E2 are thermostated chambers, and F1, F2 and F3 are respectively sulfonating agents, ketone compounds and aldehyde compound solution reagent bottles.

FIG. 2 is a graph of the SAF according to example 3 of the present invention, wherein the illustration B is the SAF.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise. It is to be understood that the scope of the invention is not to be limited to the specific embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.

As mentioned above, there are mainly the following 6 existing SAF synthesis processes:

(1) dissolving NaOH in a certain amount of water to form a solution, adding the solution into a reactor with a reflux condenser, then adding acetone, controlling the temperature below 52 ℃, and dropwise adding a mixture consisting of formaldehyde (37%), sodium metabisulfite and water after the addition; after the dropwise addition is finished, the temperature is raised to 80 ℃ for constant-temperature reaction for 2 hours, water is added for dilution, and the temperature is cooled to below 50 ℃ to obtain a finished product. The process is mainly characterized in that: the reaction period is longer (about 22h), the molecular weight distribution of the reaction product is not uniform, the product color is dark, the dispersibility and the stability of the product are poor, and the product has certain air-entraining property when being added into concrete.

(2) In the reaction flask with reflux condenser, prepare the sodium sulfite solution of certain concentration earlier, add acetone under the low temperature (40 ℃), after the backward flow certain time, slowly add formaldehyde by dropping funnel, the stirring prevents to overflow the pot: after the addition, the mixture is heated to 80-120 ℃, and the mixture reacts for 3-6 hours at constant temperature, so that a brownish red liquid finished product with the concentration of 30-40% can be obtained. The process is mainly characterized in that: the technological process is simple to operate, the equipment investment is less, the alkali amount and the temperature in the synthesis process are key, the temperature rise speed of the system can be controlled by adjusting the formaldehyde dripping speed in the reaction process, the obtained product has deep color and luster, and the water reducing rate, namely the dispersibility is good.

(3) Adding required amount of sodium sulfite and proper amount of water into a reaction bottle with a reflux condenser, controlling the temperature of the system (below 70 ℃), and gradually adding mixed solution of acetone, formaldehyde and sodium metabisulfite within specified time; after the addition is finished, reacting for 0.5-3 h at 50-70 ℃, then heating to 60-70 ℃ and reacting for 1-3 h at constant temperature to obtain a dark brown red liquid product. The process controls the reaction temperature by adding a mixed solution of formaldehyde, acetone and sodium metabisulfite step by step. The feeding temperature is low and the volatilization of raw materials is less in the technical process; the obtained product has dark color and moderate water reducing rate, namely, dispersity; but has the disadvantages of complicated equipment, more production steps and great influence by environment and climate.

(4) Dissolving a certain amount of sodium metabisulfite in a certain amount of water, respectively adding a 30% NaOH solution and 37% formaldehyde, heating to 50-70 ℃ after adding, then dripping a mixed solution of acetone and formaldehyde, reacting for lh, heating to 95 ℃, and then carrying out reflux reaction for 1h to obtain a finished product. The technological process is simple to operate, but the temperature control is critical. The obtained product has light color and good water solubility, and has good water reducing rate and slump retaining effect for the water reducing agent; the disadvantages of easy gelling, long reaction time, complex process and need of additional catalyst in the production process.

(5) Dissolving a sulfonating agent and a catalyst into water under stirring in a reactor with a reflux condenser, adding 37% of formaldehyde, and dropwise adding a mixed solution consisting of acetone and formaldehyde at 60-65 ℃; and quickly dripping formaldehyde after the addition, reacting for 2 hours at the temperature of 95 ℃, and then cooling to the temperature below 50 ℃ to obtain a finished product. The process has low requirement on the control of the reaction temperature and short reaction period (about 7 hours). The obtained product has light color, high water reducing rate, good high-temperature slump retaining effect and good adaptability to different cements; the disadvantage is that formaldehyde is added in three portions, and the addition amount of each portion is difficult to determine accurately.

(6) Sequentially adding water, sodium sulfite and acetone into a reaction bottle with a reflux condenser, uniformly stirring, heating to 50-60 ℃, and preserving heat for a period of time; dropwise adding a quantitative mixture of formaldehyde and crotonaldehyde, and keeping the temperature at 70 ℃ in the feeding process; after the aldehyde is added, reacting for 4 hours at the constant temperature of 90 ℃; cooling to room temperature, and adjusting the pH value of the product to about 2 by using a 50% sulfuric acid solution; heating the reaction solution to 60 ℃, and continuously introducing nitrogen into the reactor to exhaust air; weighing quantitative ferric sulfate, water and coated furfural, and respectively adding into a reactor; then adding a certain amount of 30% hydrogen peroxide solution, and stirring and reacting for 2h at 60 ℃; after cooling to room temperature, the reaction mixture was neutralized with 35% strength sodium hydroxide to give a graft polymer solution having a solids content of 27%. The process has the characteristics of relatively complex process and high precision requirement; the synthesized product has lighter color, lower viscosity and better water reducing rate, namely, dispersibility; the disadvantages are that the equipment is complex and not easy to operate. The above six processes have different problems respectively, and the invention adopts a continuous process, wherein the raw materials of acetone, formaldehyde and sodium sulfite in the step (2) are mixed according to the following proportion: acetone: formaldehyde: sodium sulfite-6: 3:1, performing molecular design by controlling process conditions to prepare a sulfonated acetone-formaldehyde polycondensate SAF coal water slurry dispersant.

According to the above method for synthesizing SAF, the synthesis reaction mechanism of SAF is divided into 3 steps, i.e., cross aldol condensation reaction, nucleophilic addition reaction of ketone, and subsequent condensation reaction. Wherein the cross aldol condensation reaction is in an alkaline medium, enol negative ions generated by acetone with alpha-hydrogen react with carbon positive ions provided by carbonyl in formaldehyde without alpha-hydrogen to generate hydroxymethyl acetone, so that the hydroxymethyl acetone and ketene reach chemical equilibrium in the first stage and perform addition reaction with a sulfite sulfonation nucleophilic reaction component, and finally, a hydroxyl compound in the solution is dehydrated under the heating condition to generate polycondensate hydroxyl sulfonate. Firstly, dropwise adding acetone at normal temperature, reacting at low temperature for a period of time, and then dropwise adding formaldehyde solution, wherein the reaction temperature is easy to control, and the obtained SAF is a condensate with good water solubility. However, in this process, when acetone and formaldehyde are added dropwise to a sodium sulfite solution, the reaction temperature is difficult to control, and the obtained SAF is a gel. In the condensation reaction stage, along with the increase of the viscosity, the water reducing performance of the water reducing agent is firstly improved, and is gradually reduced after reaching the maximum, the viscosity of the reaction product is synchronously increased, and if the reaction is not stopped in time, the system product is converted into a three-dimensional polymer to lose the water reducing performance and the water solubility. Because the system is continuously reacted in the normal-pressure water solution, formaldehyde still participates in the condensation process, and not only is the dehydration condensation process between linear polymers.

In view of the above, the invention innovatively provides the synthesis of SAF in the microstructure reactor, so that the temperature can be accurately controlled, the accumulation of heat released in the subsequent polycondensation reaction is effectively reduced, the problems of serious volatilization of raw materials and formation of a colloid due to over-heating of a reaction system caused by over-heating are avoided, and the solid content in the reaction can reach more than 55%. Meanwhile, sulfonation polymerization in the microstructure reactor can be completed within millisecond, the improvement effect of the difference of reaction kinetics on the selectivity of reactants is obviously enhanced, and the molecular weight, distribution and solid content of the SAF can be conveniently controlled only by regulating and controlling the reactant proportion and temperature.

As shown in fig. 1, taking the continuous synthesis of SAF as an example, sodium sulfite solution and organic ketone are respectively pumped into a micro mixer B1 by liquid chromatography pumps a1 and a2 to react, then enter a micro-channel reactor C1 to continue to react, an intermediate product solution of sulfonated ketone is obtained at the outlet of the reactor, and continuously react with an aldehyde solution pumped into the micro mixer B2 and the micro-channel reactor C2 by a liquid chromatography pump A3 for a certain time to obtain an SAF solution, and the SAF product is obtained by rotary evaporation, ethanol precipitation, drying and grinding. D1 and D2 were placed in thermostatic water baths of different temperatures, respectively, and the raw materials used were analytically pure. The sulfonation and condensation reactions of the examples are liquid-liquid reactions.

In the sulfonation reactions in examples 1, 2, 3, 4 and 5, sodium p-toluenesulfonate, sodium amino-substituted naphthalenesulfonate, sodium metabisulfite solution, sodium sulfite and sodium lignosulfonate are respectively used as sulfonating agents, and sulfonated acetone generated in the first-step reaction is used as a raw material to carry out condensation reaction; in the embodiment 1 and 2, acetone and acetophenone are used as raw materials to carry out sulfonation reaction in a continuous kettle type reactor; examples 3 and 4 are condensation reactions in a tubular reactor using formaldehyde and acetaldehyde as starting materials, respectively. Example 5 is a condensation reaction of sulfonated acetone in a micro-structured reactor with an aqueous solution of sodium hydroxide (5: 1 mass ratio of water to sodium hydroxide) as a catalyst.

The invention is further illustrated by the following examples, which are not to be construed as limiting the invention thereto. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

The method for measuring the solid content of the product in the embodiment of the invention comprises the following steps: the dried weighing flask and the lid were weighed first for mass m₁Adding the fully stirred dispersing agent into a weighing bottle, immediately covering the bottle, and weighing the mass m₂Finally, the total mass m after drying and cooling is weighed₃Solids content is generally expressed as a percentage.

The calculation formula is as follows: dispersant solid content (%) ═ m₃-m₁)/(m₂-m₁))×100。

The equipment conditions for determining the molecular weight and molecular weight distribution of the product in the embodiment of the invention are as follows: gel permeation chromatography Waters1515, Waters 2487Dual adsorbent Detector, USA, Ultrahydrogel 120and 250columns, mobile phase 0.10mol/L NaNO₃The relative molecular mass is based on the standard sample of sodium polystyrene sulfonate, and the flow rate of the mobile phase is 0.50 ml/min. The apparent viscosity and slurry rheology of the coal water slurry was determined by ARES-G2, Anton Paar MCR 302.

Example 1

The sodium p-toluenesulfonate and acetone solution were added into a volume of 10m³In the continuous stirred tank reactor, the equivalent ratio of sodium p-toluenesulfonate to acetone is 2.0: respectively introducing the generated sulfonated acetone solution and formaldehyde solution into another continuous stirring tank type reactor, controlling the temperature at minus 10 ℃, the stirring speed at 218r/min, the average retention time at 160min, collecting a reaction product at an outlet, neutralizing the product solution, drying by rotary evaporation, precipitating by ethanol, drying and grinding to obtain the sulfonated acetone-formaldehyde condensation polymer, wherein the solid content of the sulfonated acetone-formaldehyde condensation polymer is 18%.

Example 2

The acetophenone solution and the amino-substituted sodium naphthalene sulfonate solution are introduced into a reactor with the volume of 10m³In the continuous stirred tank reactor, the ratio of the acetophenone solution to the sodium amino-substituted naphthalenesulfonate is 1: 1.5, respectively introducing the generated sulfonated acetophenone solution and formaldehyde into another continuous stirring kettle type reactor, controlling the temperature at 0 ℃, stirring speed at 120r/min, average residence time at 160min, collecting reaction products at an outlet, neutralizing the product solution, drying by rotary evaporation, precipitating ethanol, and dryingDrying and grinding to obtain the substituted naphthalene sulfonated acetophenone formaldehyde polycondensate with the solid content of 28 percent.

Example 3

Sodium sulfite solution was mixed with acetone according to 1: 3, pumping the mixture into a tubular reactor with the temperature controlled at 20 ℃, the diameter of 100mm and the length of 5m by a liquid chromatography pump, controlling the retention time of the materials to be 10min, respectively introducing the generated sulfonated acetone solution and formaldehyde solution into the other tubular reactor, controlling the temperature to be 90 ℃, controlling the average retention time to be 20min, neutralizing and rotary-evaporating the product solution to be dry, precipitating ethanol, drying and grinding to obtain SAF, wherein the solid content of the SAF is 35%.

As seen from the spectrum of FIG. 2, 3425.5cm is the stretching vibration absorption peak of hydroxyl; 2923.2cm is the stretching vibration peak of C-H bond on aliphatic molecular chain, 2852.5cm is CH₃The stretching vibration peak of (2), 1619.6cm is the stretching vibration absorption peak of carbonyl; 1449.4cm is the asymmetric deformation vibration absorption peak of methyl; 1180. at l045cm is-SO₃A stretching vibration peak of the alkylsulfonate; SAF is explained to be a polymer compound containing hydrophilic groups such as carbonyl group, hydroxyl group and sulfonic group, which not only provide water solubility of the SAF polycondensate, but also give color to the polycondensate as a color-forming or color-assisting group.

Example 4

Sodium sulfite solution was mixed with acetone according to 1: 5, pumping the mixture into a tubular reactor with the temperature controlled at 20 ℃, the diameter of 10mm and the length of 15m by a liquid chromatography pump, controlling the retention time of the materials at 15min, respectively introducing the generated sulfonated acetone solution and acetaldehyde solution into the other tubular reactor, controlling the temperature at 65 ℃, controlling the average retention time at 25min, neutralizing the product solution, evaporating to dryness, precipitating with ethanol, drying and grinding to obtain the sulfonated acetone-acetaldehyde polycondensate, wherein the solid content of the sulfonated acetone-acetaldehyde polycondensate is 40%.

Example 5

Mixing sodium lignosulfonate with acetone according to a ratio of 1: 3 in an equivalent ratio, and simultaneously pumped by a liquid chromatography pump into a cross-toe micromixer reactor (V2, IMM, Germany) whose channel dimensions (μm) are 25 × 21 × 37, followed by a polytetrafluoroethylene capillary tube with an internal diameter of 0.6mm and a length of 10m, the reaction product and the formaldehyde solution being injected into a further glass T-type micromixer: and (3) controlling the reaction temperature of the T-mixer to be 10 ℃, and neutralizing, evaporating to dryness, precipitating with ethanol, drying and grinding the collected reaction product solution to obtain the lignin sulfonated acetone formaldehyde polycondensate, wherein the solid content of the lignin sulfonated acetone formaldehyde polycondensate is 52%.

Examples 6 to 11

Examples 6 to 8 were carried out in a continuous tubular reactor under the same reaction conditions as in example 4, using sodium sulfite solution and acetone as raw materials in B₁，C₁The intermediate product of sulfonated acetone and dihydroxyacetone solution is put in B₂，C₂The solid content of the product is shown in the table I.

Examples 9-11 were conducted in a micro-structured reactor using the same reaction conditions as in example 5 (different reaction conditions are shown in Table I), and using sodium lignosulfonate solution and acetone as raw materials B₁，C₁Performing sulfonation reaction, and dissolving formaldehyde solution in B₂，C₂The polycondensation reaction is carried out, and the solid content of the product is shown in the table I.

Examples 6 to 8, examples 9 to 11

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents can be made in the technical solutions described in the foregoing embodiments, or equivalents thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.

Claims

1. The application of a continuous reactor in the continuous synthesis of sulfonated ketone-aldehyde condensates;

2. A method for continuously synthesizing a sulfonated ketone aldehyde condensate, comprising: the sulfonated ketone-aldehyde condensate is continuously synthesized in a continuous reactor based on the ketone sulfonation method.

3. The method of claim 2, wherein the method comprises:

and (3) reacting the sulfonated ketone compound solution with the aldehyde compound solution in a continuous reactor under an alkaline environment, and purifying a reaction product to obtain a sulfonated ketone-aldehyde condensation product.

4. The method of claim 3, wherein the purifying step comprises neutralization, drying, crystallization, secondary drying, and grinding.

5. The method of claim 2, wherein the continuous reactor is a micro-structured reactor, a fully mixed flow reactor, or a tubular reactor; preferably a micro-structured reactor;

Wherein the sulfonating agent comprises sodium lignosulfonate, sodium sulfite, sodium pyrosulfite, sodium imidazolyl-containing sulfonate, thiazolyl sodium sulfonate, pyridyl sodium sulfonate, aryl sodium sulfonate, substituted naphthalene sodium sulfonate and aliphatic sodium sulfonate solution;

the ketone compound comprises aromatic ketone, aromatic polyketone, aliphatic ketone or aliphatic polyketone, and further comprises acetone, butanone, methyl ethyl ketone and acetophenone;

the molar ratio of the sulfonated acetone to the aldehydes is (0.8-4): 1.

the aldehyde compound comprises aliphatic aldehyde, aliphatic polyaldehyde, aromatic aldehyde or aromatic polyaldehyde; further comprising formaldehyde, acetaldehyde;

preferably, the microstructure reactor comprises a micro mixer and a micro channel reactor which are connected in sequence, and further preferably, the microstructure reactor is placed in a constant temperature water bath;

preferably, the solvent used for dissolving the sulfonating agent and the solid base is water; the mass ratio of water to sodium hydroxide is 1-8: 1.

6. The method of claim 5, wherein the micro-structured reactor is made of stainless steel, glass, quartz, ceramic, teflon, inorganic silicon or Peek material;

preferably, the microstructure reactor is of a tubular structure.

7. A method for preparing a sulfonated ketone aldehyde condensate by a continuous reaction, wherein the sulfonated ketone aldehyde condensate is SAF, the method comprising:

s2, mixing the reaction product sulfonated acetone solution in the step S1 with a formaldehyde water solution according to the molar ratio of sulfonated acetone to formaldehyde being (0.8-4): 1, injecting the mixture into another full mixed flow reactor, a tubular reactor or a micro-structure reactor, and reacting under the alkaline condition, wherein the reaction temperature is controlled to be 20-50 ℃ and the retention time is 0.5-600 s; and drying the reactant by rotary evaporation, precipitating crystals by ethanol, drying and grinding to obtain the SAF product.

8. The method of claim 7,

adding alkali liquor to form an alkaline condition, wherein the alkali is sodium hydroxide, sodium phosphate, sodium acetate, sodium carbonate or alkaline ionic liquid; preferably, the water is sodium hydroxide aqueous solution, and the mass ratio of water to sodium hydroxide is 1-8: 1;

preferably, the micro-structure reactor is a micro mixer or is formed by connecting a micro mixer and a micro-channel reactor;

9. The sulfonated ketone-aldehyde condensate produced by any one of claims 2 to 8.

10. Use of the sulfonated acetone formaldehyde condensate of claim 9 in any one or more of the following:

1) a dispersant;

2) a water reducing agent.