CN112321779B

CN112321779B - Continuous production method of water-soluble phenolic resin

Info

Publication number: CN112321779B
Application number: CN202110001034.2A
Authority: CN
Inventors: 路平娟; 王威; 刘锦阳; 芦潇; 刘太恩; 焦玉坤
Original assignee: Shandong Youquan New Material Co ltd
Current assignee: Shandong Youquan New Material Co ltd
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-04-06
Anticipated expiration: 2041-01-04
Also published as: CN112321779A

Abstract

The invention provides a continuous production method of water-soluble phenolic resin, which is carried out in a continuous production device, wherein phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution are conveyed to a mixing unit through a continuous conveying system according to the molar ratio of phenol to formaldehyde to alkaline catalyst of 1: 1.5-2.5: 0.1-0.5, are uniformly mixed, and then enter a reaction unit to react for 1-10 min at the temperature of 60-140 ℃, so that the water-soluble phenolic resin with the water dilution multiple of not less than 10 times, the solid content of not less than 40% and the viscosity of not more than 200cP is obtained.

Description

Continuous production method of water-soluble phenolic resin

Technical Field

The invention relates to a production method of phenolic resin, in particular to a continuous production method of water-soluble phenolic resin.

Background

Phenolic resins prepared by reacting phenolic compounds with aldehyde compounds have a long history, the production of the phenolic resins has a history of more than 70 years in China, and phenolic resins with various properties are derived to meet different application requirements, wherein the water-soluble phenolic resin is a thermosetting resol, and is widely applied to adhesives, impregnating compounds, various coating products and refractory materials.

With the continuous development of green and environmental protection technologies, the synthesis and production technologies of water-soluble phenolic resins have been continuously improved, and many patent documents have been reported on the synthesis of water-soluble phenolic resins, for example, chinese patents with publication numbers CN107828033A and CN110982026A disclose a preparation method of water-soluble phenolic resins, which is obtained by slowly raising the temperature at a lower reaction temperature and slowly reacting in multiple temperature zones, but in the industrial production process, the reaction temperature needs to be controlled to be lower, the time for raising, maintaining and lowering the temperature is longer, the production efficiency is low, the reaction time is too long, the product quality is poor and unstable, the temperature is raised and maintained for many times in the reaction process in each production batch, the temperature is lowered and maintained after the reaction is finished, the energy is wasted, and the intermittent kettle type production method has the disadvantages of complicated operation, and the like, Low automation degree, poor safety, large waste water amount and the like.

Regarding the continuous production method, chinese patent publication No. CN102993390A discloses a continuous production method of thermoplastic phenolic resin, the reaction temperature is a stepwise reaction temperature control, the temperature is controlled by water bath and divided into 12 temperature sections, and the controlled temperature and tube pass need to be controlled accurately.

Disclosure of Invention

Problems to be solved by the invention

The invention provides a continuous production method of water-soluble phenolic resin, aiming at solving the problems of complex operation, low production efficiency, high energy consumption and heavy pollution in the prior art.

Means for solving the problems

In order to achieve the purpose, the invention provides a method for continuously producing water-soluble phenolic resin in a continuous production device, which comprises the following specific scheme.

[1] The invention provides a continuous production method of water-soluble phenolic resin, wherein the continuous production method is carried out in a continuous production device, wherein phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution are conveyed to a mixing unit 3 through a continuous conveying system 1 according to the molar ratio of phenol to formaldehyde to alkaline catalyst of 1: 1.5-2.5: 0.1-0.5, are uniformly mixed, and then enter a reaction unit 4 to react for 1-10 min at 60-140 ℃, so that the water-soluble phenolic resin with the water dilution multiple of not less than 10 times, the solid content of not less than 40% and the viscosity of not more than 200cP is obtained; the phenol is at least one of phenol, cresol, xylenol and resorcinol.

[2] The continuous production method according to [1], wherein the concentration of the aqueous formaldehyde solution is 37-50%; the alkaline catalyst is at least one of sodium carbonate, sodium hydroxide and potassium hydroxide; the concentration of the alkaline catalyst aqueous solution is 30-50%.

[3] The continuous production method according to [1] or [2], wherein the pressure of the reaction system is controlled to be 0.1 to 0.5MPa in the continuous production method of the water-soluble phenol resin.

[4] The continuous production method according to [1] or [2], wherein the continuous production apparatus comprises a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6 and a heat exchange system;

the outlet of the continuous conveying system 1 is connected with the raw material inlet of the heat exchange system, the raw material outlet of the heat exchange system is connected with the inlet of the mixing unit 3, the outlet of the mixing unit 3 is connected with the inlet of the reaction unit 4, the outlet of the reaction unit 4 is connected with the product inlet of the heat exchange system, and the product outlet of the heat exchange system is connected with the inlet of the product receiving unit 6.

[5] The continuous production method according to [4], wherein the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7.

[6] The continuous production method according to [5], wherein an outlet of the continuous conveying system 1 is connected with a raw material inlet of the material preheating-product first-stage cooling system 2, a raw material outlet of the material preheating-product first-stage cooling system 2 is connected with an inlet of the mixing unit 3, an outlet of the mixing unit 3 is connected with an inlet of the reaction unit 4, an outlet of the reaction unit 4 is connected with a product inlet of the material preheating-product first-stage cooling system 2, a product outlet of the material preheating-product first-stage cooling system 2 is connected with an inlet of the product second-stage cooling system 5, and an outlet of the product second-stage cooling system 5 is connected with an inlet of the product receiving unit 6.

[7] The continuous production method according to [5] or [6], wherein the preheating of the material and the first-stage cooling of the product are carried out simultaneously, the reaction temperature control system 7 comprises two-stage temperature control, the temperature of a lower temperature zone is 60-90 ℃, and the temperature of a higher temperature zone is 120-140 ℃;

or the preheating of the materials and the first-stage cooling of the products are carried out simultaneously, the reaction temperature control system 7 comprises three-stage temperature control, the temperature of a lower temperature zone is 60-90 ℃, the temperature of a middle temperature zone is higher than 90 ℃ and lower than 120 ℃, and the temperature of a higher temperature zone is 120-140 ℃.

[8] The continuous production method according to [1] or [2], wherein the reaction unit 4 is a static tubular reactor, and the pipe diameter of the static tubular reactor is 6-14 mm.

[9] The continuous production method according to [5] or [6], wherein the temperature of the raw material after the material preheating-product first-stage cooling system 2 is 60-90 ℃, the temperature of the product after the material preheating-product first-stage cooling system 2 is 60-100 ℃, the temperature of the product after the product second-stage cooling system 5 is 20-25 ℃, and the material preheating and the product first-stage cooling are performed simultaneously.

ADVANTAGEOUS EFFECTS OF INVENTION

Compared with the prior art, the invention has the following advantages:

1. compared with the traditional production method of the water-soluble phenolic resin, the production efficiency is obviously improved. Production of traditional water-soluble phenolic resin is mostly intermittent kettle type production, in order to guarantee controllability and safety of reaction process, need divide in the production process dropwise add formaldehyde many times and strictly control the dropwise add speed of formaldehyde to need slowly heat up and carry out the heat preservation reaction to a plurality of reaction temperature regions, whole production process dropwise add formaldehyde, heat up, the heat preservation process is all consuming time longer, leads to production efficiency low. The water-soluble phenolic resin in the invention realizes continuous production through a continuous production device, simplifies operation by adopting automatic control, obviously improves production efficiency through a high-temperature short-time production mode, and can be effectively utilized in industrial production.

2. The invention realizes the quick preheating of the raw materials while regulating and controlling the constant temperature of each stage in the production process by designing the heat exchange system and quickly cooling the products by utilizing the high-efficiency heat exchange equipment, and reduces the energy waste compared with the processes of heating, preserving heat and cooling the reaction kettle for each production batch in kettle type production and the mode of directly cooling the reacted products.

3. The continuous production method of the water-soluble phenolic resin provided by the invention realizes continuous production, and compared with the industrial production mode in the prior art, the method is simple to operate and greatly reduces the amount of waste water. If one production batch is finished and the next batch is directly produced in the existing industrial production mode, the residual macromolecular polymer in the kettle can react with fresh raw materials to obtain a polymer with a complex molecular structure and a larger molecular weight, so that the product quality is reduced, and therefore, the reaction kettle can be cleaned after each production batch in the batch kettle type production, and a large amount of cleaning wastewater is generated during each cleaning. On the contrary, the invention adopts the continuous production method to produce the water-soluble phenolic resin, can realize the long-time continuous safe and stable production of the production device, greatly reduces the cleaning wastewater, and can directly apply the obtained product, thereby reducing the generation of the wastewater. In addition, the existing production mostly adopts the mode of normal pressure and kettle top condensation to reduce the waste gas amount, the continuous production method designed by the invention also greatly reduces the waste gas amount by controlling the pressure of the reaction system, and the production process is more green and environment-friendly.

Drawings

FIG. 1 is a schematic view showing an example of a continuous production method of a water-soluble phenol resin of the present invention;

FIG. 2 is a schematic view showing another example of the continuous production method of a water-soluble phenol resin of the present invention.

Description of the reference numerals

1. The system comprises a continuous conveying system, a material preheating-product first-stage cooling system, a mixing unit, a reaction unit, a product second-stage cooling system, a product receiving unit and a reaction temperature control system, wherein the material preheating-product first-stage cooling system is arranged in the mixing unit, the reaction unit is arranged in the reaction unit, the product second-stage cooling system is.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the drawings described herein are not to be construed as limiting the scope of the invention.

The invention provides a continuous production method of water-soluble phenolic resin, which is carried out in a continuous production device, wherein phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution are conveyed to a mixing unit 3 through a continuous conveying system 1 according to the proportion of the molar ratio of phenol to formaldehyde to alkaline catalyst of 1: 1.5-2.5: 0.1-0.5, are uniformly mixed, and then enter a reaction unit 4 to react for 1-10 min at 60-140 ℃, so that the water-soluble phenolic resin with the water dilution multiple of not less than 10 times, the solid content of not less than 40% and the viscosity of not more than 200cP is obtained.

According to the common knowledge of the technicians in the field, the phenol and the formaldehyde are subjected to addition reaction to obtain hydroxymethyl phenol, one molecule of phenol consumes three molecules of formaldehyde at most, the using amount of the formaldehyde is properly increased, the degree of the multi-hydroxymethylation of the phenol is increased, and the generated polyhydroxy phenol is increased, so that the water solubility of the phenolic resin is favorably increased.

In the invention, the phenol for producing the water-soluble phenolic resin is at least one of phenol, cresol, xylenol and resorcinol, and the concentration of the formaldehyde aqueous solution is 37-50%. In the high-temperature short-time rapid reaction, the reaction time of phenol and formaldehyde is short, and the addition reaction and the polycondensation reaction are almost simultaneously carried out, in this case, the use amount of formaldehyde is large, so that the formaldehyde reaction is incomplete, and the content of free aldehyde in the product is increased; when the amount of formaldehyde is low, the addition product is mostly monohydric methylol phenol, which not only reduces the water solubility of the polycondensation product, but also causes an increase in the content of free phenol. Therefore, the molar ratio of the phenol to the formaldehyde is 1: 1.5-2.5.

In the present invention, the basic catalyst is at least one of sodium carbonate and sodium hydroxide, and preferably sodium hydroxide. In the prior art, the catalyst is fed intermittently, and is generally completely added into a reaction kettle in advance to perform catalytic reaction at a lower temperature, so that the concentration of the catalyst is higher, and the reaction temperature is not high enough to ensure reaction controllability and avoid side reactions. The alkaline catalyst can promote the addition reaction of phenol and formaldehyde, and the amount of the polyhydric hydroxymethyl phenol can be increased by properly increasing the using amount of the alkaline catalyst, so that the water solubility of the phenolic resin is increased, but the excessive using amount of the alkaline catalyst can promote the disproportionation reaction of formaldehyde while promoting the addition reaction, and the formaldehyde is consumed. Therefore, in the present invention, a continuous production apparatus is used, preferably sodium hydroxide is used as an alkaline catalyst, and a sodium hydroxide solution and raw materials are conveyed to the continuous production apparatus together according to a certain ratio, so that a water-soluble phenolic resin with good performance can be obtained at a high temperature in a short time. The molar ratio of the phenol to the basic catalyst adopted by the invention is 1: 0.1-0.5, preferably 1: 0.1-0.3. The concentration of the alkaline catalyst aqueous solution is 30-50%.

According to the common knowledge of the technicians in the field, the synthesis of the phenolic resin has two reaction processes of addition and polycondensation, and the addition reaction of phenol and formaldehyde is taken as the main reaction at lower temperature, and the polycondensation reaction is rapidly carried out after the temperature is increased. Therefore, in the traditional process, the lower temperature is generally controlled to ensure that phenol and formaldehyde fully undergo addition reaction to obtain polyhydric hydroxymethyl phenol as much as possible, and after the addition reaction is finished, the temperature is raised to further cause the addition product to undergo polycondensation reaction. Therefore, a plurality of temperature zones are usually set, and the temperature is maintained for a period of time after the temperature is slowly raised to each temperature zone, so as to control the polycondensation reaction process and obtain a polycondensation product with a smaller polymerization degree difference.

On the contrary, the present invention is not easily conceived by those skilled in the art in a production mode using a high temperature for a short time. If a traditional production mode is adopted, a single batch of materials is too much, mass transfer and heat transfer capacities of production equipment are limited, an obvious back mixing phenomenon exists, the temperature is raised too fast or the reaction temperature is too high in the production process, the reaction process is difficult to control, the safety and the stability of the production process are reduced, a polycondensate with too wide molecular mass distribution and complex molecular structure is obtained due to the aggravation of polycondensation reaction, the problems of gel, agglomeration, even solidification and the like are caused, the product quality is poor, and therefore the production mode with high temperature and short time cannot be realized. Although chinese patent publication No. CN102993390A discloses a continuous production method of thermoplastic phenolic resin, which employs a pipe reactor and a stepwise reaction temperature control, there is no significant breakthrough in reaction temperature and reaction time, and a method of obtaining a product by reacting at a lower reaction temperature for a long time is still employed, which mainly fails to solve the problems of safety and low product quality caused by too severe polycondensation reaction at a higher reaction temperature. According to the invention, a large number of experiments and researches show that a continuous production device is adopted for phenol and formaldehyde aqueous solution under the action of an alkaline catalyst, phenol and formaldehyde can quickly perform addition reaction in the continuous production device under the conditions of high temperature and short time to obtain monohydric or polyhydric hydroxymethyl phenol, then polycondensation is quickly performed, the temperature is immediately reduced after a certain polymerization degree is reached, and the reaction is stopped, so that the phenolic resin with good water solubility is obtained, a high-temperature short-time process method is obtained, and the problem which is difficult to solve in the existing process is effectively improved.

In the process of continuously producing the water-soluble phenolic resin, the control on the reaction temperature and the reaction time needs to be mastered, if the reaction temperature is too high, the polycondensation reaction is too fast, so that the requirement on the control precision of the reaction time is increased, the control difficulty is increased, and the risk that the resin is solidified in a reactor and blocks a reaction channel exists; if the reaction temperature is too low, the polycondensation reaction is slow, so that the polymerization degree of the resin is low, and although the viscosity is low, the resin is cured too slowly, so that the use of the phenolic resin is influenced; if the reaction time is too long, the polycondensation degree is too high and uneven, the viscosity is too high, and the risk of blocking a reaction channel due to resin solidification exists; if the reaction time is too short, the degree of polycondensation is too low, and the content of free monomers in the product is too high, which, although having high water solubility, may result in too slow curing of the resin during later use and greater environmental pollution. Therefore, the reaction temperature adopted by the invention is 60-140 ℃, and the reaction time is 1-10 min. At such a reaction temperature and reaction time, the production process of the present invention can control the progress of the addition and polycondensation reactions well, and can obtain a phenol resin having good water solubility without the above-mentioned adverse effects due to too fast polycondensation reaction.

In the invention, because the reaction temperature is higher, light components such as formaldehyde, water and the like are easy to vaporize at higher temperature, so that the reaction system is unstable, the material proportion is unbalanced, part of formaldehyde is lost, the environment is polluted, and the product quality is reduced. In order to ensure continuous and stable operation of production and avoid loss of formaldehyde, the invention carries out backpressure on a continuous production device, and controls the pressure of a reaction system to be 0.1-0.5 MPa.

The production of the water-soluble phenolic resin is carried out in a continuous production device, and the continuous production device comprises a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6 and a heat exchange system; the outlet of the continuous conveying system 1 is connected with the raw material inlet of the heat exchange system, the raw material outlet of the heat exchange system is connected with the inlet of the mixing unit 3, the outlet of the mixing unit 3 is connected with the inlet of the reaction unit 4, the outlet of the reaction unit 4 is connected with the product inlet of the heat exchange system, and the product outlet of the heat exchange system is connected with the inlet of the product receiving unit 6.

Further, the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7.

As shown in fig. 1 and fig. 2, as a non-limiting example, an outlet of the continuous conveying system 1 is connected to an inlet of a raw material of the material preheating-product first-stage cooling system 2, an outlet of the raw material of the material preheating-product first-stage cooling system 2 is connected to an inlet of the mixing unit 3, an outlet of the mixing unit 3 is connected to an inlet of the reaction unit 4, an outlet of the reaction unit 4 is connected to an inlet of the material preheating-product first-stage cooling system 2, an outlet of the material preheating-product first-stage cooling system 2 is connected to an inlet of the product second-stage cooling system 5, and an outlet of the product second-stage cooling system 5 is connected to an inlet of the product receiving unit 6.

In the invention, material preheating and first-stage product cooling are simultaneously carried out in the material preheating-first-stage product cooling system 2, the reaction temperature control system 7 at least comprises two-stage temperature control, the temperature of a lower temperature zone is 60-90 ℃, and the temperature of a higher temperature zone is 120-140 ℃.

In the invention, each system and unit in the continuous production device for producing the water-soluble phenolic resin are connected with the automatic control system, and the continuous automatic production of the water-soluble phenolic resin can be realized by adopting automatic operation.

In the present invention, it should be noted that, unless explicitly stated or limited, the connection between each system and the unit should be understood in a broad sense, for example, it may be a direct pipe connection, a pipe connection connected with a pipe valve, an indirect connection through an intermediate medium, a fixed connection, or a detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the invention, the preheating of the raw material and the first-stage cooling of the product are preferably completed in the same heat exchange equipment by the material preheating-product first-stage cooling system 2, so that the comprehensive utilization of energy is realized, and the problems that the polymerization degree is increased, the distribution of the polymerization molecular weight is widened and the quality of the product is influenced because the product continues to react at a higher temperature due to too slow cooling and too long cooling time in the cooling process of the product are solved. Therefore, the process of preheating the raw materials and cooling the products needs to be completed quickly, high-efficiency heat exchange equipment such as a plate heat exchanger or a wound tube heat exchanger is optimized, quick heat exchange of multiple strands of raw materials and products can be achieved, and the time for completing the heat exchange process of the multiple strands of raw materials and the products is preferably not longer than 1 min. The temperature of the raw materials is 60-90 ℃ after preheating and is not higher than the temperature of a lower temperature region in the reaction unit, the temperature of the product after primary cooling is 60-100 ℃, in order to directly obtain stable water-soluble phenolic resin, the product after primary cooling needs to be continuously and rapidly cooled, the product is cooled to 20-25 ℃ after secondary cooling of the product secondary cooling system 5, and the cooled product is collected in a product receiving unit 6, preferably a receiving tank.

In the present invention, the continuous conveying system 1 is used for conveying raw materials and providing power for the flow of the raw materials in the continuous production device. In the industrialized small-batch production process, phenol, such as phenol, is in a solid state due to small purchase amount and most of the phenol is barreled, so that the phenol can be directly conveyed after being heated and melted or can be dissolved in formaldehyde aqueous solution and conveyed by a feeding pump for convenience of conveying the phenol; in the industrial mass production process, phenol is transported to a tank area by a tank truck for heat preservation and is stored in a heat preservation way, and the phenol is mostly in a liquid state and can be directly transported by a feeding pump. In order to realize smooth discharging of raw materials from feeding, the continuous conveying system preferably comprises at least two feeding pumps with a certain pressure tolerance range, the upper pressure limit of the feeding pumps is not lower than 0.2MPa, and if the upper pressure limit of the feeding pumps is lower than 0.2MPa, the power provided in the process of conveying the materials is limited, so that the products cannot be discharged smoothly, or the feeding is stopped due to the overpressure of the feeding pumps caused by too high pressure drop of the materials in the flowing process.

In the present invention, the mixing unit 3 in the continuous production apparatus is used for rapidly and fully mixing the phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution, and the mixer adopted by the mixing unit is preferably a micro mixer with a mixing channel and a heat exchange channel, or a micro channel reactor or a static mixer. The phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution undergo the process of preheating before entering the mixing unit 3, the preheated materials can react while being rapidly mixed in the mixing unit 3, and the reaction process releases heat, so the temperature control of the mixing process is preferably carried out, and is consistent with the temperature control range of a lower temperature zone of the reaction unit 4. The temperature control of the mixing unit 3 and the reaction unit 4 is realized by a reaction temperature control system 7. In the mixing unit 3, the time for mixing the materials is preferably not longer than 10 s.

In the invention, the phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution enter the reaction unit 4 to react after being preheated and mixed. The reaction unit 4 is preferably a static tubular reactor, the static tubular reactor can be coiled by a single pipe or multiple pipes, and is preferably a multi-pipe coiled static tubular reactor, wherein a pipe pass inlet of the static tubular reactor is connected with a mixed liquid outlet of the mixing unit 3, the reaction liquid flows in the pipe pass of the static tubular reactor and belongs to plug flow, back mixing is avoided, so that polycondensation can be rapidly carried out along with temperature rise in the flowing process after the addition product of the hydroxymethyl phenol is generated at high temperature, and a mixture of oligomers with similar polycondensation degree can be obtained.

The shell side of the static tubular reactor is connected with a reaction temperature control system 7 in the heat exchange system, the reaction temperature control system 7 at least comprises two-stage temperature control, the temperature of a lower temperature zone is 60-90 ℃, and the temperature of a higher temperature zone is 120-140 ℃. The addition and polycondensation reactions occur in both the lower temperature region and the higher temperature region, the addition reaction is mainly performed in the lower temperature region, the residual free phenol and free formaldehyde in the higher temperature region are quickly consumed, the content of the free phenol and the free formaldehyde in the product is reduced, and in addition, the polycondensation reaction of the hydroxymethyl phenol quickly occurs in the higher temperature region in a short time, so that the mixture of the oligomer is obtained. In one example, the reaction temperature control system 7 further comprises an intermediate temperature zone, the intermediate temperature zone is higher than 90 ℃ and lower than 120 ℃, i.e. the reaction temperature control system 7 comprises three-stage temperature control. After the reaction materials are transited from a lower temperature area to a higher temperature area through a middle temperature area, the reaction is smoothly carried out, and the reaction is more controllable. The residence time of the reaction liquid in the reaction unit 4 is 1-10 min, wherein the reaction time of the reaction liquid in a higher temperature region is not higher than that in a lower temperature region, so that the content of free phenol and free aldehyde in the product is reduced, and simultaneously, the oligomer with better water solubility is obtained.

In the invention, in order to ensure the heat exchange efficiency and the mass transfer effect of the static tubular reactor and to ensure the continuous safe and stable production of the phenolic resin, the proper pipe diameter size is usually selected through calculation and experiments, the heat exchange efficiency can be reduced and the mass transfer effect can be reduced due to too thick pipe diameter, the potential safety hazard of reaction out of control exists in the production process, the heat exchange efficiency and the mass transfer effect can be improved due to too thin pipe diameter, but the input cost and the processing difficulty of equipment can be increased, and the pipe diameter of the static tubular reactor adopted by the invention is 6-14 mm.

In the invention, the materials for producing the water-soluble phenolic resin are all industrial grade materials which are all commercially available; the various components of the continuous production unit employed, such as the piping, valves, controllers, feed pumps, mixers, static pipe reactors, receiving tanks, etc., are commercially available or custom made, but the entire continuous production unit is not commercially available or known to those skilled in the art.

In one example of the present invention, as shown in fig. 1, the continuous production apparatus includes a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6, and a heat exchange system; further, the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7. Wherein, the preheating of the materials and the first-stage cooling of the products are carried out simultaneously in the same heat exchange equipment, and the reaction temperature control system 7 comprises two-stage temperature control.

The exit linkage of continuous conveyor system 1 the material preheats-the raw materials entry of the first order cooling system of product 2, the material preheats-the raw materials exit linkage of the first order cooling system of product 2 the entry of mixing unit 3, the exit linkage of mixing unit 3 the entry of reaction unit 4, the exit linkage of reaction unit 4 the material preheats-the product entry of the first order cooling system of product 2, the material preheats-the product exit linkage of the first order cooling system of product 2 the entry of product second level cooling system 5, the exit linkage of product second level cooling system 5 the entry of product receiving element 6.

The continuous conveying system 1 in the continuous production device for the water-soluble phenolic resin comprises three feed pumps which can respectively convey the phenol, the formaldehyde aqueous solution and the alkaline catalyst aqueous solution in a liquid state. The mixing unit 3 is a micro mixer with a heat exchange channel and a mixing channel, the reaction unit 4 is a static tubular reactor with the pipe diameter of 6-14 mm, a pipe pass inlet of the static tubular reactor is connected with a mixed liquid outlet of the mixing unit 3, and a shell pass of the static tubular reactor is connected with a reaction temperature control system 7. The reaction temperature control system 7 comprises two-stage temperature control, wherein the temperature of a lower temperature zone is 60-90 ℃, and the temperature of a higher temperature zone is 120-140 ℃.

As a non-limiting example, the water-soluble phenolic resin is continuously produced by using the continuous production device. Phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution are respectively conveyed to a material preheating-product first-stage cooling system 2 by three feed pumps of a continuous conveying system 1 according to the molar ratio of phenol to formaldehyde to alkaline catalyst of 1: 1.5-2.5: 0.1-0.5, and are quickly preheated to 60-90 ℃ in the material preheating-product first-stage cooling system 2. The preheated raw materials enter a mixing unit 3 to be quickly and uniformly mixed, and the uniformly mixed reaction liquid enters a lower temperature region with the temperature of 60-90 ℃ and a higher temperature region with the temperature of 120-140 ℃ in a reaction unit 4 to react for 1-10 min under the condition that the system backpressure is 0.1-0.5 MPa. The polycondensate obtained through the reaction is quickly cooled to 60-100 ℃ through a material preheating-product first-stage cooling system 2, then is quickly cooled to 20-25 ℃ through a product second-stage cooling system 5, and then is transferred to a receiving tank of a product receiving unit 6. The time for preheating the materials is preferably not longer than 1min, the time for mixing the materials is preferably not longer than 10s, and the time for cooling the product is preferably not longer than 1 min.

In another example of the present invention, as shown in fig. 2, the continuous production apparatus comprises a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6, and a heat exchange system; further, the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7. Wherein, the preheating of the materials and the first-stage cooling of the products are carried out simultaneously in the same heat exchange equipment, and the reaction temperature control system 7 comprises three-stage temperature control.

The continuous transfer system 1 in the continuous production apparatus for water-soluble phenol resin includes two feed pumps for transferring the aqueous solution of phenol and formaldehyde in a liquid state and the aqueous solution of the basic catalyst, respectively. The mixing unit 3 is a micro mixer with a heat exchange channel and a mixing channel, the reaction unit 4 is a static tubular reactor with the pipe diameter of 6-14 mm, a pipe pass inlet of the static tubular reactor is connected with a mixed liquid outlet of the mixing unit 3, and a shell pass of the static tubular reactor is connected with a reaction temperature control system 7. The reaction temperature control system 7 comprises three-stage temperature control, wherein the temperature of a lower temperature zone is 60-90 ℃, the temperature of a middle temperature zone is higher than 90 ℃ and lower than 120 ℃, and the temperature of a higher temperature zone is 120-140 ℃.

As a non-limiting example, the water-soluble phenolic resin is continuously produced by using the continuous production device. The method comprises the steps of preparing a uniform mixed raw material solution from phenol and formaldehyde aqueous solution in a molar ratio of 1: 1.5-2.5. The raw material liquid and the alkaline catalyst aqueous solution are respectively conveyed to a material preheating-product first-stage cooling system 2 by two feed pumps of a continuous conveying system 1 according to the molar ratio of phenol to alkaline catalyst of 1: 0.1-0.5, and are quickly preheated to 60-90 ℃ in the material preheating-product first-stage cooling system 2. The preheated raw materials enter a mixing unit 3 to be quickly and uniformly mixed, and the uniformly mixed reaction liquid enters a lower temperature region with the temperature of 60-90 ℃, a middle temperature region with the temperature higher than 90 ℃ and lower than 120 ℃ and a higher temperature region with the temperature of 120-140 ℃ in a reaction unit 4 to react for 1-10 min under the condition that the system backpressure is 0.1-0.5 MPa. The polycondensate obtained through the reaction is quickly cooled to 60-100 ℃ through a material preheating-product first-stage cooling system 2, then is quickly cooled to 20-25 ℃ through a product second-stage cooling system 5, and then is transferred to a receiving tank of a product receiving unit 6. The time for preheating the materials is preferably not longer than 1min, the time for mixing the materials is preferably not longer than 10s, and the time for cooling the product is preferably not longer than 1 min.

The invention obtains the process conditions which can obviously improve the production efficiency through a large amount of research and experiments, and is feasible through industrial amplification verification. The improvement in production efficiency is reflected in the percentage of annual production improvement in the continuous production process of water-soluble phenolic resins over the existing batch tank production processes. The environmental assessment document disclosed in 2018 of a certain company mentions that 4 sets of 20 cubic meter reaction kettles are adopted, the yield of 1042 batches produced every year is 5 ten thousand tons (please refer to https:// www.doc88.com/p-2894893882817. html), under the condition of using the same input cost, the adopted continuous production device in the technical scheme provided by the invention is equivalent to an 8 cubic meter reaction kettle device, the annual yield of 1042 batches produced every year by using the 8 cubic meter reaction kettles in the technical scheme in the environmental assessment is 5000 tons, and the production efficiency is at least doubled compared with that of the invention.

The continuous production method of the water-soluble phenolic resin provided by the invention not only can realize industrial continuous production and obviously improve the production efficiency, but also effectively overcomes the defect of high energy consumption in the prior production technology, and particularly embodies the energy-saving energy under the condition of producing equivalent products. Also by taking the technical scheme (please refer to https:// www.doc88.com/p-2894893882817. html) mentioned in the environmental comment document published by a company 2018 as comparison, the invention can produce at least 5 million energy-saving cards per hour.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in further detail with reference to specific examples, which include but are not limited to the following examples, and any modifications made to the details and forms of the technical solutions of the present invention without departing from the meaning and scope of the present application fall within the scope of the present invention.

In the examples, the viscosity was measured with an NDJ-1 type rotary viscometer with reference to GB/T14074-.

In the present invention, the solid content, the content of free aldehyde and free phenol are in mass% unless otherwise specified.

Example 1

As shown in fig. 1, the continuous production apparatus for water-soluble phenol resin comprises a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6 and a heat exchange system; the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7. Wherein, the preheating of the materials and the first-stage cooling of the products are carried out simultaneously in the same heat exchange equipment, and the reaction temperature control system 7 comprises two-stage temperature control.

The continuous conveying system 1 in the continuous production device for the water-soluble phenolic resin comprises three feed pumps which respectively convey the phenol, the formaldehyde aqueous solution and the alkaline catalyst aqueous solution in a liquid state. The mixing unit 3 is a micro mixer with a heat exchange channel and a mixing channel, the reaction unit 4 is a static tubular reactor with the pipe diameter of 6mm, a pipe pass inlet of the static tubular reactor is connected with a mixed liquid outlet of the mixing unit 3, and a shell pass of the static tubular reactor is connected with a reaction temperature control system 7.

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at a flow speed of 32.7kg/h through the continuous conveying system 1, and a 37% formaldehyde aqueous solution and a 50% sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 90 ℃ together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.5:0.3: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 3s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 1min, wherein the temperature of the lower temperature region is 90 ℃, the temperature of the higher temperature region is 140 ℃, and the pressure of a reaction system is controlled to be 0.5MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 30s to 100 ℃ by the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 100s to 25 ℃ by the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 40cP, water dilution factor of 50, solid content of 42.5%, free aldehyde content of 0.4%, and free phenol content of 10%.

Example 2

The composition and connection of the continuous production apparatus for a water-soluble phenol resin were the same as in example 1, wherein the reaction unit 4 was a static tubular reactor having a tube diameter of 8 mm.

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at the flow speed of 43.6kg/h through the continuous conveying system 1, 37% of formaldehyde aqueous solution and 50% of sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.7:0.1:1 and are preheated to 80 ℃. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 4s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 3min, wherein the temperature of the lower temperature region is 80 ℃, the temperature of the higher temperature region is 135 ℃, and the pressure of a reaction system is controlled to be 0.5MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 30s to 93 ℃ through the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 85s to 23 ℃ through the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 68cP, water dilution factor of 45, solid content of 43.1%, free aldehyde content of 0.4%, and free phenol content of 8.5%.

Example 3

The composition and connection of the continuous production apparatus for a water-soluble phenol resin were the same as in example 1, wherein the reaction unit 4 was a static tubular reactor having a tube diameter of 12 mm.

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at the flow speed of 50.1kg/h through the continuous conveying system 1, 44% of formaldehyde aqueous solution and 40% of potassium hydroxide solution enter the material preheating-product first-stage cooling system 2 together with phenol according to the molar ratio of 2:0.3:1 of formaldehyde to sodium hydroxide to the phenol and are preheated to 70 ℃. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 5s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 7min, wherein the temperature of the lower temperature region is 70 ℃, the temperature of the higher temperature region is 130 ℃, and the pressure of a reaction system is controlled to be 0.4MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 45s to 84 ℃ through the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 80s to 20 ℃ through the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity 105cP, water dilution 28 times, solid content 48.2%, free aldehyde content 0.3%, free phenol content 5.2%.

Example 4

The composition and connection of the continuous production apparatus for a water-soluble phenol resin were the same as in example 1, wherein the reaction unit 4 was a static tubular reactor having a tube diameter of 14 mm.

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at the flow speed of 89.2kg/h through the continuous conveying system 1, and a 50% formaldehyde aqueous solution and a 30% sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 60 ℃ together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 2.2:0.5: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 5s to be uniformly mixed, and then enter a lower temperature area and a higher temperature area of the reaction unit 4 to react for 5min, wherein the temperature of the lower temperature area is 65 ℃, the temperature of the higher temperature area is 125 ℃, and the pressure of a reaction system is controlled to be 0.2MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 55s to 71 ℃ through the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 60s to 22 ℃ through the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 85cP, water dilution factor of 37 times, solid content of 45.8%, free aldehyde content of 0.3%, and free phenol content of 6.3%.

Example 5

The composition and connection of the continuous production apparatus for a water-soluble phenol resin were the same as in example 1, wherein the reaction unit 4 was a static tubular reactor having a tube diameter of 10 mm.

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at a flow speed of 77.2kg/h through the continuous conveying system 1, and a 50% formaldehyde aqueous solution and a 30% sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 60 ℃ together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 2.5:0.2: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 5s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 10min, wherein the temperature of the lower temperature region is 60 ℃, the temperature of the higher temperature region is 120 ℃, and the pressure of a reaction system is controlled to be 0.1MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 60s to 60 ℃ by the material preheating-product first-stage cooling system 2, and then is cooled for 45s to 23 ℃ by the product second-stage cooling system 5 and then transferred to a receiving tank of the product receiving unit 6.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 200cP, water dilution factor of 10, solid content of 52.8%, free aldehyde content of 0.5%, and free phenol content of 3.1%.

Example 6

As shown in fig. 2, the continuous production apparatus for water-soluble phenol resin comprises a continuous conveying system 1, a mixing unit 3, a reaction unit 4, a product receiving unit 6 and a heat exchange system; the heat exchange system comprises a material preheating-product first-stage cooling system 2, a product second-stage cooling system 5 and a reaction temperature control system 7. Wherein, the preheating of the materials and the first-stage cooling of the products are carried out simultaneously in the same heat exchange equipment, and the reaction temperature control system 7 comprises three-stage temperature control.

The continuous conveying system 1 in the continuous production device for the water-soluble phenolic resin comprises two feeding pumps which respectively convey a mixed solution of phenol and formaldehyde aqueous solution and an alkaline catalyst aqueous solution. The mixing unit 3 is a micro mixer with a heat exchange channel and a mixing channel, the reaction unit 4 is a static tubular reactor with the pipe diameter of 10mm, a pipe pass inlet of the static tubular reactor is connected with a mixed liquid outlet of the mixing unit 3, and a shell pass of the static tubular reactor is connected with a reaction temperature control system 7.

Phenol and xylenol with the molar ratio of 1:1 are dissolved in 44% formaldehyde water solution, wherein the molar ratio of the phenol to the formaldehyde is 1:1.8, the mixed solution of the phenol and the formaldehyde is continuously conveyed to a material preheating-product first-stage cooling system 2 through a continuous conveying system 1 at the flow rate of 125.6 kg/h, and meanwhile, 30% sodium hydroxide solution is conveyed to the material preheating-product first-stage cooling system 2 at the molar ratio of the sodium hydroxide to the phenol of 0.3:1 and is preheated to 80 ℃. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 7s to be uniformly mixed, and then enter a lower temperature area, an intermediate temperature area and a higher temperature area of the reaction unit 4 to react for 8min, wherein the temperature of the lower temperature area is 80 ℃, the temperature of the intermediate temperature area is 110 ℃, the temperature of the higher temperature area is 130 ℃, and the pressure of a reaction system is controlled to be 0.2MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 50s to 81 ℃ through the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 65s to 21 ℃ through the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: the viscosity was 145cP, the water dilution factor was 18 times, the solids content was 50%, the free aldehyde content was 0.4%, and the free phenol content was 3.4%.

Example 7

The composition and connection of the continuous production apparatus for a water-soluble phenol resin were the same as in example 6, wherein the reaction unit 4 was a static tubular reactor having a tube diameter of 10 mm.

Phenol, cresol, xylenol and resorcinol in a molar ratio of 1:1:1:1 are dissolved into 37% of formaldehyde water solution, wherein the molar ratio of the phenol to the formaldehyde is 1:2, the mixed solution of the phenol and the formaldehyde is continuously conveyed to a material preheating-product first-stage cooling system 2 through a continuous conveying system 1 at a flow rate of 72.9 kg/h, and meanwhile, a 30% sodium hydroxide solution is conveyed to the material preheating-product first-stage cooling system 2 at a molar ratio of the sodium hydroxide to the phenol of 0.3:1 and preheated to 60 ℃. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 6s to be uniformly mixed, and then enter a lower temperature area, an intermediate temperature area and a higher temperature area of the reaction unit 4 to react for 9min, wherein the temperature of the lower temperature area is 65 ℃, the temperature of the intermediate temperature area is 90 ℃, the temperature of the higher temperature area is 135 ℃, and the pressure of a reaction system is controlled to be 0.3MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 55s to 85 ℃ by the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 60s to 22 ℃ by the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: the viscosity was 55cP, the dilution factor with water was 31 times, the solids content was 40%, the free aldehyde content was 0.5%, and the free phenol content was 8.4%.

Examples 1 to 7 were all pilot scale examples, and these pilot scale experiments were industrially scaled up to obtain the following examples 8 to 11.

Example 8

Phenol is continuously conveyed to the material preheating-product first-stage cooling system 2 at a flow speed of 752kg/h through the continuous conveying system 1, and a 44% formaldehyde aqueous solution and a 40% sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 70 ℃ simultaneously with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 2:0.3: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 8s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 7min, wherein the temperature of the lower temperature region is 80 ℃, the temperature of the higher temperature region is 130 ℃, and the pressure of a reaction system is controlled to be 0.4MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 40s to 83 ℃ by the material preheating-product first-stage cooling system 2, and then is cooled for 75s to 20 ℃ by the product second-stage cooling system 5 and then transferred to a receiving tank of the product receiving unit 6.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 112cP, water dilution factor of 26, solid content of 48.4%, free aldehyde content of 0.4%, and free phenol content of 5.9%.

Compared with the existing batch kettle type production, the annual output of the single set of continuous production device of the embodiment is improved by 2 times compared with that of 1042 batches of 8 cubic meters of reaction kettle production, and at least 7.5 ten thousand kilocalories per hour of energy is saved.

Example 9

Phenol is continuously conveyed to a material preheating-product first-stage cooling system 2 at a flow speed of 698kg/h through a continuous conveying system 1, and a 37% formaldehyde aqueous solution and a 50% sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 80 ℃ simultaneously with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 2.5:0.5: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 9s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 3min, wherein the temperature of the lower temperature region is 85 ℃, the temperature of the higher temperature region is 135 ℃, and the pressure of a reaction system is controlled to be 0.2MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 55s to 82 ℃ by the material preheating-product first-stage cooling system 2, and then is cooled for 65s to 23 ℃ by the product second-stage cooling system 5 and then transferred to a receiving tank of the product receiving unit 6.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: the viscosity was 134cP, the dilution factor with water was 24 times, the solids content was 43.5%, the free aldehyde content was 0.1%, and the free phenol content was 2.4%.

Compared with the existing batch kettle type production, the annual output of the single set of continuous production device of the embodiment is improved by 2.6 times compared with that of 1042 batches of 8 cubic meters of reaction kettle production, and at least 10.3 ten thousand calories per hour of energy is saved.

Example 10

Phenol is continuously conveyed to a material preheating-product first-stage cooling system 2 at the flow speed of 584kg/h through a continuous conveying system 1, 37% of formaldehyde aqueous solution and 50% of sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.5:0.1:1 and are preheated to 60 ℃. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 5s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 10min, wherein the temperature of the lower temperature region is 60 ℃, the temperature of the higher temperature region is 125 ℃, and the pressure of a reaction system is controlled to be 0.2MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 20s to 90 ℃ through the material preheating-product first-stage cooling system 2, and then is transferred to a receiving tank of the product receiving unit 6 after being cooled for 80s to 21 ℃ through the product second-stage cooling system 5.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 44cP, water dilution factor of 48, solid content of 45%, free aldehyde content of 0.3%, and free phenol content of 9%.

Compared with the existing batch kettle type production, the annual output of the single set of continuous production device of the embodiment is improved by 1 time compared with that of 1042 batches of 8 cubic meters of reaction kettle production, and at least 5 ten thousand calories per hour is saved.

Example 11

Phenol is continuously conveyed to a material preheating-product first-stage cooling system 2 at the flow speed of 960kg/h through a continuous conveying system 1, 37 percent of formaldehyde aqueous solution and 50 percent of sodium hydroxide solution enter the material preheating-product first-stage cooling system 2 to be preheated to 85 ℃ together with phenol according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.8:0.4: 1. The preheated materials simultaneously enter the mixing unit 3 to be mixed for 10s to be uniformly mixed, and then enter a lower temperature region and a higher temperature region of the reaction unit 4 to react for 1min, wherein the temperature of the lower temperature region is 90 ℃, the temperature of the higher temperature region is 140 ℃, and the pressure of a reaction system is controlled to be 0.5MPa in the reaction process. The reaction liquid flowing out of the reaction unit 4 is cooled for 55s to 85 ℃ by the material preheating-product first-stage cooling system 2, and then is cooled for 70s to 25 ℃ by the product second-stage cooling system 5 and then transferred to a receiving tank of the product receiving unit 6.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 75cP, water dilution factor of 35, solid content of 44.5%, free aldehyde content of 0.3%, and free phenol content of 6.2%.

Compared with the existing batch kettle type production, the annual output of the single set of continuous production device of the embodiment is improved by 3 times compared with that of 1042 batches of 8 cubic meters of reaction kettle production, and at least 11.9 ten thousand calories per hour of energy is saved.

Comparative example 1

The continuous production apparatus used in this comparative example did not include a material preheating-product first-stage cooling system, and the other units were the same as in example 9, in which the pipe diameter of the static tubular reactor was 12 mm.

Phenol, 37% formaldehyde aqueous solution and 50% sodium hydroxide solution are conveyed into a mixer (mixing unit) by a feeding pump according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.5:0.1:1 and mixed for 5s at 60 ℃, wherein the flow rate of phenol is 194.6kg/h, the mixed solution flowing out of the mixing unit enters a static tubular reactor (reaction unit) and reacts for 30min at 80 ℃ and normal pressure, and the reaction solution flowing out of the reaction unit is transferred into a receiving tank of a product receiving unit after being cooled to 21 ℃ by a product cooling system.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: the viscosity was 350cP, the water dilution factor was 8 times, the solid content was 39.5%, the free aldehyde content was 0.6%, and the free phenol content was 12.5%.

Compared with the single set of production device in the example 9, the single set of continuous production device of the comparative example has 67 percent of production efficiency, saves energy and reduces 5 ten thousand kilocalories per hour under the condition of the same productivity as the example 9, and has 34 percent of production efficiency lower than that of two 15 cubic meters of reaction kettles in the conventional batch kettle type production.

Compared with the example 9, the comparative example adopts the same material ratio, the difference lies in that the production device is different and the production mode of low temperature and long time is adopted in the comparative example, compared with the example 9, the product quality of the comparative example is reduced, and the production efficiency is obviously reduced.

Comparative example 2

The continuous production apparatus used in this comparative example did not include a material preheating-product first-stage cooling system, and the reaction unit used a microchannel reactor having a channel size of 3mm, which was otherwise the same as that of example 10.

Phenol, 37% formaldehyde aqueous solution and 50% sodium hydroxide solution are conveyed into a mixer (mixing unit) by a feeding pump according to the molar ratio of formaldehyde to sodium hydroxide to phenol of 1.8:0.4:1 and mixed for 8s at 70 ℃, wherein the flow rate of phenol is 96kg/h, the mixed solution flowing out of the mixing unit enters a microchannel reactor (reaction unit) and reacts for 30s at the temperature of 90 ℃ and 140 ℃ in sequence, the reaction system is normal pressure, and the reaction solution flowing out of the reaction unit is transferred into a receiving tank of a product receiving unit after being cooled to 21 ℃ by a product cooling system.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity 230cP, water dilution factor 9, solid content 39.1%, free aldehyde content 0.7%, free phenol content 11%.

The production efficiency of the single set of continuous production device of the comparative example is one tenth of that of the single set of production device in the example 10, the energy is saved by 11.9 ten thousand calories/h under the condition of the same production energy as that of the example 10, and the production efficiency is reduced by 60 percent compared with that of two 15 cubic meters of reaction kettles produced by the conventional batch kettle type.

Compared with the example 10, the comparative example adopts the same material proportion and the same continuous production mode, and has the difference that the comparative example adopts a micro-channel reactor with smaller channel size and a mixed structure, a material preheating-product first-stage cooling system is not arranged in the production device, and normal pressure conditions are adopted in the production process, compared with the example 10, the product quality of the comparative example is reduced, and the production efficiency of a single set of production device is far lower than that of the example 10.

Comparative example 3

Adding 291.9kg of phenol into a stirring kettle with heat exchange, heating to 50 ℃ until the phenol is molten, adding 50% of sodium hydroxide solution, uniformly stirring, heating to 70-90 ℃, dropwise adding 37% of formaldehyde solution, continuing to keep the temperature for 2 hours after the dropwise adding is finished, cooling to 21 ℃ after the reaction is finished, and transferring the product into a storage tank. The molar ratio of formaldehyde, sodium hydroxide and phenol used was 1.5:0.1: 1.

The viscosity, the water solubility, the solid content and the contents of free aldehyde and free phenol of the produced water-soluble phenolic resin are detected in sequence, and the detection result is as follows: viscosity of 600cP, water dilution factor of 3, solid content of 38.5%, free aldehyde content of 1.1%, and free phenol content of 13%.

The comparative example and the example 9 adopt the same material ratio, the difference is that the adopted production device is a batch reaction kettle, and compared with the example 9, the product of the comparative example has obviously larger viscosity and obviously lower water dilution factor.

Claims

1. The continuous production method of the water-soluble phenolic resin is characterized by being carried out in a continuous production device, wherein phenol, formaldehyde aqueous solution and alkaline catalyst aqueous solution are conveyed to a mixing unit (3) through a continuous conveying system (1) according to the molar ratio of phenol to formaldehyde to alkaline catalyst of 1: 1.5-2.5: 0.1-0.5, are uniformly mixed, and then enter a reaction unit (4) to react for 1-10 min at the temperature of 60-140 ℃, so that the water-soluble phenolic resin with the water dilution multiple of not less than 10 times, the solid content of not less than 40% and the viscosity of not more than 200cP is obtained;

the phenol is at least one of phenol, cresol, xylenol and resorcinol; wherein,

the reaction unit (4) comprises a lower temperature region with the temperature of 60-90 ℃ and a higher temperature region with the temperature of 120-140 ℃.

2. The continuous production method according to claim 1, wherein the concentration of the aqueous formaldehyde solution is 37 to 50%; the alkaline catalyst is at least one of sodium carbonate, sodium hydroxide and potassium hydroxide; the concentration of the alkaline catalyst aqueous solution is 30-50%.

3. The continuous production method according to claim 1 or 2, wherein the pressure of the reaction system is controlled to 0.1 to 0.5MPa in the continuous production method of the water-soluble phenol resin.

4. The continuous production process according to claim 1 or 2, wherein the continuous production apparatus comprises a continuous conveying system (1), a mixing unit (3), a reaction unit (4), a product receiving unit (6) and a heat exchange system;

the outlet of the continuous conveying system (1) is connected with the raw material inlet of the heat exchange system, the raw material outlet of the heat exchange system is connected with the inlet of the mixing unit (3), the outlet of the mixing unit (3) is connected with the inlet of the reaction unit (4), the outlet of the reaction unit (4) is connected with the product inlet of the heat exchange system, and the product outlet of the heat exchange system is connected with the inlet of the product receiving unit (6).

5. The continuous production method according to claim 4, characterized in that the heat exchange system comprises a material preheating-product first-stage cooling system (2), a product second-stage cooling system (5) and a reaction temperature control system (7).

6. The continuous production method according to claim 5, characterized in that the outlet of the continuous conveying system (1) is connected with the raw material inlet of the material preheating-product first-stage cooling system (2), the raw material outlet of the material preheating-product first-stage cooling system (2) is connected with the inlet of the mixing unit (3), the outlet of the mixing unit (3) is connected with the inlet of the reaction unit (4), the outlet of the reaction unit (4) is connected with the product inlet of the material preheating-product first-stage cooling system (2), the product outlet of the material preheating-product first-stage cooling system (2) is connected with the inlet of the product second-stage cooling system (5), the outlet of the product second-stage cooling system (5) is connected with the inlet of the product receiving unit (6).

7. The continuous production method according to claim 5 or 6, characterized in that the preheating of the material and the first-stage cooling of the product are carried out simultaneously, the reaction temperature control system (7) comprises two-stage temperature control, the temperature of the lower temperature zone is 60-90 ℃, and the temperature of the higher temperature zone is 120-140 ℃;

or the preheating of the materials and the first-stage cooling of the products are carried out simultaneously, the reaction temperature control system (7) comprises three-stage temperature control, the temperature of a lower temperature zone is 60-90 ℃, the temperature of a middle temperature zone is higher than 90 ℃ and lower than 120 ℃, and the temperature of a higher temperature zone is 120-140 ℃.

8. The continuous production process according to claim 1 or 2, wherein the reaction unit (4) is a static tubular reactor having a tube diameter of 6 to 14 mm.

9. The continuous production method according to claim 5 or 6, wherein the temperature of the raw material after being preheated by the material preheating-product first-stage cooling system (2) is 60-90 ℃, the temperature of the product after being preheated by the material preheating-product first-stage cooling system (2) is 60-100 ℃, and the temperature of the product after being cooled by the product second-stage cooling system (5) is 20-25 ℃, wherein the material preheating and the product first-stage cooling are carried out simultaneously.