Production method and production device of phenolic resin

Abstract

The invention relates to the technical field of phenolic resin, in particular to a phenolic resin production method and a phenolic resin production device. Phenol, cresol, tert-butyl phenol and cardanol are added into a mixing tank to be evenly mixed to form mixed phenol; the mixed phenol and alkali liquor enter a mixer to be mixed to obtain mixed liquor; the mixed solution and a formaldehyde aqueous solution enter a first annular reactor to react to obtain a pre-polymerized solution; the pre-polymerized liquid and trimethyl hydroxyethyl ethylenediamine enter a second annular reactor for continuous reaction to obtain phenolic resin; the batching tank, the mixer, the first annular reactor and the second annular reactor are connected in sequence; according to the phenolic resin production method and the phenolic resin production device, the contact area and the heat dissipation effect of all the materials in the reaction process are increased, rapid reaction is promoted, phenolic resin is promoted to be upgraded to the high-performance and environment-friendly direction, and a high-solid and low-viscosity phenolic resin product is produced.

Description

Technical Field

[0001] The invention belongs to the field of phenolic resins, and in particular, relates to a production method and a production device for phenolic resins. Background Art

[0002] As a high-performance synthetic resin with a long history, phenolic resin is widely used in wood processing, refractory materials, casting sand molds, friction materials, anti-corrosion coatings, composite materials and other fields due to its excellent adhesion, high temperature resistance, chemical corrosion resistance and mechanical strength. In recent years, with the increasingly stringent environmental regulations, water-soluble phenolic resin has become an important development direction to replace traditional solvent-based resins due to its low volatile organic compound (VOC) emissions, environmental friendliness and ease of use. The market demand for high-solid and low-viscosity water-soluble phenolic resin has increased significantly, especially in the application of high-end wood adhesives and environmentally friendly composite materials.

[0003] At present, phenolic resins are mostly produced by intermittent devices. However, this intermittent production method has some obvious disadvantages. For example, during the intermittent reaction process, key parameters such as temperature, pH value, reaction time, etc. are difficult to control accurately, resulting in large fluctuations in product quality between batches, making it difficult to meet the precise requirements of solid content and viscosity, and poor production stability; intermittent production requires frequent operations such as feeding, heating, insulation, cooling, and discharging, with a long production cycle, low equipment utilization, and low production efficiency; because a large amount of toxic, flammable and explosive raw materials such as formaldehyde and phenol are required during the reaction process, the intermittent reactor is prone to local overheating or reaction out of control under high temperature and high pressure conditions, and there are safety hazards such as leakage and explosion, with high safety risks; the molecular weight distribution is wide and the product uniformity is poor, resulting in unstable mechanical properties after the resin is cured; higher free phenol and free aldehyde residues not only reduce product performance, but also make wastewater and waste gas treatment difficult, which is not in line with the development trend of green chemical industry.

[0004] Therefore, it is urgent to develop a production device and production method of phenolic resin that can ensure stable product quality, improve production efficiency, and be green and environmentally friendly. Breakthroughs in continuous production equipment and production processes will promote the upgrading of phenolic resins towards high performance and environmental protection, and meet the urgent needs for high-quality resins in new energy, high-end manufacturing and other fields. This is of extremely critical strategic significance for promoting the sustainable development of the phenolic resin industry. Summary of the invention

[0005] Based on the above problems, the present invention provides a method for producing a phenolic resin, comprising the following steps: S1, adding phenol, cresol, tert-butylphenol and cardanol into a mixing tank and mixing them evenly to form a mixed phenol; S2, the mixed phenol and the alkali solution enter into a mixer and are mixed to obtain a mixed solution; S3, the mixed solution and the formaldehyde aqueous solution enter the first annular reactor to react to obtain a prepolymer solution; S4, the prepolymer solution and trimethylolethylethylenediamine enter the second annular reactor to continue reacting to obtain a phenolic resin; The cresol is a mixture of one or more of o-cresol, m-cresol and p-cresol, and the tert-butylphenol is a mixture of one or more of o-tert-butylphenol, m-tert-butylphenol and p-tert-butylphenol; The batching tank, the mixer, the first annular reactor and the second annular reactor are connected in sequence; the first annular reactor comprises a first vertical tubular reactor, a first circulation pump and a first heat exchanger; the second annular reactor comprises a second vertical tubular reactor, a second circulation pump and a second heat exchanger; the first annular reactor and the second annular reactor are provided with a stirrer; and the reaction time is 5 to 20 minutes.

[0006] Furthermore, the mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:(1-3):(1-2):(1-2); and the temperature of the batching tank is controlled at 50-70°C.

[0007] Furthermore, the mass concentration of the alkali solution is 30-40% sodium hydroxide solution, the mass ratio of the alkali solution to the mixed phenol is 1:(3-10); and the temperature of the mixer is 50-90°C.

[0008] Furthermore, the mass concentration of the formaldehyde aqueous solution is 37-50%; the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1:(1-2); The agitator is provided with a discharge hole, and the formaldehyde aqueous solution is added into the first annular reactor through the discharge hole; a spray plug is installed on the discharge hole, and the spray plug has an intermediate column and an annular portion, a gap is formed between the annular portion and the intermediate column, and the formaldehyde aqueous solution is sprayed out through the gap; the reaction temperature of the first annular reactor is 60~80℃.

[0009] Furthermore, the mass ratio of the trimethylolethylethylenediamine to the mixed phenol is (0.1-0.5):1; the trimethylolethylethylenediamine is added into the second annular reactor through an agitator and a discharge hole on the agitator; a spray plug is installed on the discharge hole, the spray plug has an intermediate column and an annular portion, a gap is formed between the annular portion and the intermediate column, and the trimethylolethylethylenediamine is sprayed out through the gap; the gap between the intermediate column and the annular portion of the spray plug in the first annular reactor is smaller than the gap between the intermediate column and the annular portion of the spray plug in the second annular reactor; the reaction temperature of the second annular reactor is 90-120°C.

[0010] A phenolic resin production device comprises A batching tank, wherein the batching tank has a phenol inlet, a cresol inlet, a tert-butylphenol inlet, and a cardanol inlet, and is used to mix phenol, cresol, tert-butylphenol, and cardanol to form a mixed phenol; A mixer, wherein the mixer is provided with a mixed phenol inlet and an alkali solution inlet, and the mixer is used to mix the mixed phenol with the alkali solution; The first annular reactor comprises a first vertical tubular reactor, a first circulation pump and a first heat exchanger which are interconnected; the first annular reactor is used for the mixed liquid to react with the formaldehyde aqueous solution to form a prepolymer liquid; The second annular reactor comprises a second vertical tubular reactor, a second circulation pump and a second heat exchanger which are interconnected; the second annular reactor is used for reacting the prepolymer liquid with trimethylolethylethylenediamine to generate phenolic resin; The batching tank, the mixer, the first annular reactor and the second annular reactor are connected in series in sequence; The first vertical tubular reactor and the second vertical tubular reactor are provided with a stirrer; the stirrer is a hollow structure and is provided with a discharge hole.

[0011] Furthermore, the discharge port of the mixer is connected to the feed port of the first annular reactor; the mixer has mixing and heat exchange functions; the first annular reactor is provided with a prepolymer liquid outlet, and the second annular reactor is provided with a prepolymer liquid inlet; the prepolymer liquid outlet of the first annular reactor is connected to the prepolymer liquid inlet of the second annular reactor.

[0012] Furthermore, a rotary joint is provided at the upper end of the agitator; the rotary joint of the first vertical tubular reactor is provided with an inlet for formaldehyde aqueous solution, and the rotary joint of the second vertical tubular reactor is provided with an inlet for trimethylhydroxyethylethylenediamine.

[0013] Furthermore, the agitator includes a stirring shaft and stirring fins, and a plurality of groups of stirring fins are arranged axially along the stirring shaft. The stirring fins in the same group are distributed circumferentially along the stirring shaft. The stirring shaft and / or the stirring fins are provided with discharge holes.

[0014] Furthermore, a spray plug is installed on the discharge hole, and the spray plug has an intermediate column and an annular portion, a gap is formed between the annular portion and the intermediate column, the inner diameter of the annular portion is larger than the outer diameter of the intermediate column, and the annular portion and the intermediate column are connected by a radial member.

[0015] The technical solution provided by the present invention has the following advantages compared with the prior art: 1. The present invention provides a phenolic resin production device, comprising a mixer, a first annular reactor and a second annular reactor connected in series in sequence, wherein the first annular reactor and the second annular reactor both comprise a vertical tubular reactor, a circulation pump and a heat exchanger which are interconnected. The production device can continuously and stably produce high-solid and low-viscosity phenolic resin, improve production efficiency, and ensure the quality stability of different batches of phenolic resin; by means of a stirring shaft, stirring fins and a discharge hole coordinated with the stirring shaft and stirring fins arranged inside the vertical tubular reactor, continuous dispersed feeding of formaldehyde aqueous solution and trimethylhydroxyethylethylenediamine in the vertical tubular reactor is achieved , which increases the contact area and contact opportunities between materials, improves the efficiency of mixing and reaction, and improves the mass transfer and heat transfer efficiency of materials, thereby improving the uniformity of molecular weight distribution and consistency of molecular weight of the product phenolic resin, and reducing the content of free aldehydes and free phenols; by arranging a circulating pump and a heat exchanger connected to the vertical tubular reactor in the first annular reactor and the second annular reactor, the coupling of forced mass transfer and heat exchange is realized, which promotes heat transfer, accelerates the diffusion rate of reactants and products, and further improves the uniformity of molecular weight distribution and consistency of molecular weight of the product phenolic resin, ensuring the safety, efficiency and sustainability of the reaction.

[0016] 2. Two discharge pipes are respectively provided in the first vertical tubular reactor and the second vertical tubular reactor. Discharging materials through the discharge pipes further promotes uniform distribution and mixing of materials, avoids the situation of excessively high or low local concentration, thereby improving reaction efficiency and further improving the uniformity of molecular weight distribution of phenolic resin.

[0017] 3. Trimethylolethylethylenediamine not only acts as a catalyst but also as a reaction aid in the prepolymer solution, which promotes the condensation reaction, enhances the crosslinking density of the phenolic resin, increases the solid content of the phenolic resin, and acts as a plasticizer to reduce the viscosity of the phenolic resin, thereby improving the mechanical properties, heat resistance, and chemical stability of the phenolic resin. On the one hand, it promotes the polymerization reaction of free aldehydes and free phenols in the prepolymer solution, and on the other hand, it reduces the content of free phenol and free aldehyde in the phenolic resin by reacting with free aldehydes and free phenols respectively. In the curing stage of the phenolic resin, the emission of free phenol and free aldehyde during curing is significantly reduced, thereby alleviating environmental pollution problems. In addition, the addition of trimethylolethylethylenediamine effectively prevents the oxidation process of free phenol, further improves the color performance of the phenolic resin, and improves the product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the production device structure of the present invention; Figure 2 yes Figure 1 A partial enlarged view of the middle discharge hole; Figure 3 It is a top view of the spray plug installed in the discharge hole in the present invention.

[0020] Description of reference numerals: 1-mixer; 2-first annular reactor; 21-first vertical tubular reactor; 22-first circulation pump; 23-first heat exchanger; 3-second annular reactor; 31-second vertical tubular reactor; 32-second circulation pump; 33-second heat exchanger; 4-dosing tank; 5-spray plug; 51-middle column; 52-annular part; 53-radial part; 6-discharge hole. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms, "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] The present invention also provides a method for producing phenolic resin, the operating steps are as follows: S1, adding phenol, cresol, tert-butylphenol and cardanol into a mixing tank and mixing them evenly to form a mixed phenol, S2, the mixed phenol and the alkali solution enter into a mixer to mix to obtain a mixed solution, S3, the mixed solution and the formaldehyde aqueous solution enter the first annular reactor to react to obtain a prepolymer solution, S4, the prepolymer solution and trimethylolethylethylenediamine enter the second annular reactor to continue reacting to obtain phenolic resin.

[0025] The cresol is a mixture of one or more of o-cresol, m-cresol and p-cresol, and the tert-butylphenol is a mixture of one or more of o-tert-butylphenol, m-tert-butylphenol and p-tert-butylphenol.

[0026] Phenol, cresol, tert-butylphenol and cardanol enter the batching tank, and are heated, melted and mixed by the heat exchange medium in the heat exchange jacket of the batching tank to obtain a mixed phenol. The mixed phenol enters the mixer and reacts with the alkali solution transported to the mixer to obtain a mixed liquid. The mixed liquid enters the first discharge pipe in the reaction chamber through the feed port of the first vertical tubular reactor. The formaldehyde aqueous solution is transported to the rotary joint by a centrifugal pump and flows into the hollow stirring shaft through the rotary joint. The formaldehyde aqueous solution flows out through the discharge holes of the stirring shaft and the stirring fins and enters the reaction chamber of the first vertical tubular reactor. At the same time, part of the first circulating liquid that has undergone heat exchange in the first heat exchanger is discharged through the second discharge pipe. The discharge hole of the pipe flows into the reaction chamber of the first vertical tubular reactor. In the reaction chamber, the mixed phenol reacts with formaldehyde under the catalytic action of the alkali solution to obtain the first circulating liquid. The first circulating liquid is transported to the first heat exchanger through the first circulating pump. The heat in the first circulating liquid is transferred to the heat exchange medium through heat exchange. Part of the first circulating liquid after heat exchange enters the second discharge pipe through the circulating liquid inlet of the first vertical tubular reactor, and flows into the reaction chamber through the second discharge pipe to continue to participate in the polycondensation reaction. At the same time, part of the first circulating liquid after heat exchange flows out through the prepolymer liquid outlet of the first annular reactor and enters the third discharge pipe of the second vertical tubular reactor. The prepolymer liquid flows out through the discharge hole on the third discharge pipe and enters the reaction chamber. At this time, the trimethylhydroxyethylethylenediamine enters the stirring shaft of the second vertical tubular reactor through the rotary joint of the second vertical tubular reactor. The trimethylhydroxyethylethylenediamine entering the stirring shaft flows out from the discharge holes on the stirring shaft and the stirring fins under the state of the stirring shaft rotating and stirring, and then enters the reaction chamber of the second vertical tubular reactor. At the same time, part of the second circulating liquid after heat exchange enters the fourth discharge pipe through the circulating liquid inlet of the second vertical tubular reactor and then flows into the reaction chamber of the second vertical tubular reactor from the discharge hole. In the reaction chamber, the prepolymer liquid and the second circulating liquid are mixed at The polymerization reaction continues in the reaction chamber, and at the same time, trimethylolethylethylenediamine reacts with the prepolymer liquid and unreacted mixed phenol and formaldehyde in the second circulating liquid to obtain a second circulating liquid. The second circulating liquid is transported to the second heat exchanger through a second circulating pump, and the heat in the second circulating liquid is transferred to the heat exchange medium through heat exchange. Part of the second circulating liquid after heat exchange enters the fourth discharge pipe through the circulating liquid inlet of the second vertical tubular reactor, and flows into the reaction chamber through the fourth discharge pipe to continue the reaction. At the same time, part of the second circulating liquid after heat exchange flows out through a discharge port on the connecting pipeline between the second heat exchanger and the second vertical tubular reactor to obtain a product phenolic resin.

[0027] In the present invention, the higher the mass ratio of phenol in the mixed phenol, the more favorable it is to increase the crosslinking density of the phenolic resin, improve the hardness of the phenolic resin after curing, and enhance the thermal stability and chemical stability of the phenolic resin after curing. However, too high hardness will reduce the flexibility and impact resistance of the paint film. The lower the mass ratio of phenol in the mixed phenol, the more favorable it is to improve the flexibility of the phenolic resin after curing, but it will reduce the thermal stability and chemical stability of the phenolic resin after curing. The viscosity of the phenolic resin is reduced by introducing cardanol. However, the higher the mass ratio of cardanol in the mixed phenol, the lower the viscosity of the phenolic resin and the higher its antioxidant property, but the production cost is increased. On the contrary, the lower the mass ratio of cardanol in the mixed phenol, the lower the production cost, but the effect on the flexibility and viscosity of the phenolic resin is not obvious. Preferably, the mass ratio of phenol, cresol, tert-butyl phenol and cardanol is 10: (1-3): (1-2): (1-2), and more preferably, the mass ratio of phenol, cresol, tert-butyl phenol and cardanol is 10: (1.5-2.5): (1.2-1.8): (1.2-1.8).

[0028] In step S1, in order to ensure that phenol, cresol, tert-butylphenol and cardanol are uniformly mixed and fully melted, the temperature of the batching tank is controlled at 50-70°C.

[0029] In the present invention, alkali solution is a catalyst for polycondensation reaction, and the mass ratio of alkali solution to mixed phenol indirectly affects the performance of phenolic resin by affecting the polycondensation reaction rate and crosslinking degree of phenolic resin. When the mass ratio of alkali solution to mixed phenol is higher, alkali solution can accelerate the polycondensation reaction rate, but when it is too high, it will affect the molecular weight and distribution of phenolic resin and destroy the thermal stability structure of phenolic resin after curing; when the mass ratio of alkali solution to mixed phenol is too low, the reaction rate is reduced, the production cycle is extended, and the crosslinking degree of phenolic resin is also reduced. Preferably, the mass ratio of alkali solution to mixed phenol is 1: (3~10), and the mass concentration of alkali solution is 30~40% sodium hydroxide solution. More preferably, the mass ratio of alkali solution to mixed phenol is 1: (5~7), and the mass concentration of alkali solution is 35% sodium hydroxide solution.

[0030] In order to prevent the mixed liquid from locally increasing in temperature and inducing side reactions when entering the first vertical tubular reactor, the temperature of the mixer is 50-90°C, preferably, the temperature of the mixer is 70-80°C.

[0031] In the present invention, when the mass ratio of the mixed phenol to the formaldehyde aqueous solution is relatively high, that is, the mixed phenol is excessive, the mixed phenol reacts with formaldehyde to mainly generate a phenolic resin with a linear structure, which has good flexibility after curing, but relatively low thermal stability and mechanical strength; when the mass ratio of the mixed phenol to the formaldehyde aqueous solution is relatively low, that is, the formaldehyde is excessive, the generated polyhydroxymethylphenol derivatives increase, and the derivatives are cross-linked and cured to form a phenolic resin with a network structure, which improves the thermal stability and mechanical strength of the phenolic resin after curing, but the hardness of the phenolic resin is relatively high. In order to balance the hardness and flexibility of the phenolic resin after curing and ensure its thermal stability and mechanical strength, preferably, the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1: (1~2), and the mass concentration of the formaldehyde aqueous solution is 37~50%. More preferably, the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1: (1.4~1.8), and the mass concentration of the formaldehyde aqueous solution is 40%.

[0032] In the second annular reactor, trimethylol hydroxyethyl ethylenediamine can not only act as a catalyst to promote the formation of hydroxymethyl phenol monomers and further condensation reactions, but can also act as a reaction aid to react with formaldehyde and mixed phenols that do not participate in the reaction in the reaction system to reduce the content of free phenol and free aldehyde in the phenolic resin. As a preferred embodiment, the mass ratio of trimethylol hydroxyethyl ethylenediamine to mixed phenol is (0.1-0.5):1, and more preferably, the mass ratio of trimethylol hydroxyethyl ethylenediamine to mixed phenol is (0.2-0.4):1.

[0033] In the present invention, under catalytic conditions, formaldehyde and mixed phenol are subjected to addition reaction in the first annular reactor to obtain hydroxymethylphenol monomers of different sizes, and then some monomers, formaldehyde and mixed phenol that do not participate in the reaction are subjected to polycondensation reaction to obtain thermosetting phenolic resin. When the reaction temperature of the first annular reactor is higher, the hydroxymethylphenol monomers are continuously polymerized to generate highly cross-linked phenolic resins, and the phenolic resins have high viscosity and high hardness after curing; when the reaction temperature of the first annular reactor is lower, the mixed phenol and formaldehyde are mainly subjected to addition reaction, and the polycondensation reaction rate is low, and the generated phenolic resin has good flexibility after curing, but poor hardness. Preferably, the reaction temperature of the first annular reactor is 60-80°C, and more preferably, the reaction temperature of the first annular reactor is 65-75°C.

[0034] The prepolymer liquid obtained in the first annular reactor enters the second annular reactor, which is conducive to promoting monomer polymerization and improving the crosslinking density of the phenolic resin under the catalytic action of trimethylol hydroxyethyl ethylenediamine, and trimethylol hydroxyethyl ethylenediamine can also be used as a reaction aid to react with unreacted mixed phenol and formaldehyde in the prepolymer liquid, reduce the content of free aldehyde and free phenol in the phenolic resin, and achieve the effect of increasing solid content and reducing viscosity. Due to the high temperature required for the polymerization of hydroxymethylphenol monomers and the low concentration of monomers, mixed phenols and formaldehyde in the prepolymer liquid, the temperature of the second annular reactor is higher than that of the first annular reactor, and the reaction temperature of the second annular reactor is 90-120°C, preferably, the reaction temperature of the second annular reactor is 100-110°C.

[0035] In the present invention, the circulation flow rate refers to the speed at which the reactants circulate in the first annular reactor or the second annular reactor. The residence time is the average time that the reactants experience from entering to leaving the first annular reactor or the second annular reactor. The reaction time is equal to the sum of the residence time of the reactants in the first annular reactor and the residence time of the reactants in the second annular reactor.

[0036] High circulation velocity can improve the material mixing and mass transfer efficiency in the annular reactor, improve the dispersibility of the material, avoid excessive local concentration, thereby improving the reaction rate and conversion rate, but reduce the reaction time, resulting in insufficient condensation degree of the phenolic resin, small molecular weight, and increase the content of free phenol and free aldehyde in the phenolic resin; lower circulation velocity can reduce the mixing and mass transfer efficiency in the annular reactor, resulting in excessive local concentration in the reactor, thereby reducing the reaction rate and conversion rate, but prolonging the reaction time, causing side reactions, and then affecting the color and performance of the phenolic resin. In order to improve the reaction speed as much as possible without affecting the performance of the phenolic resin, the circulation velocity of the circulation pump in the present invention is 10 to 50 times the sum of the mixed phenol feed flow rate, and the reaction time is 5 to 20 minutes. Preferably, the circulation velocity of the circulation pump is 20 to 40 times the sum of the mixed phenol feed flow rate, and the reaction time is 10 to 15 minutes.

[0037] The production device of synthesizing phenolic resin by the above production method is as follows: The production device of phenolic resin comprises a batching tank, a mixer, a first annular reactor and a second annular reactor which are connected in series in sequence, wherein the first annular reactor comprises a first vertical tubular reactor, a first circulation pump and a first heat exchanger which are interconnected; the second annular reactor comprises a second vertical tubular reactor, a second circulation pump and a second heat exchanger which are interconnected; the discharge port of the batching tank is connected to the mixed phenol inlet of the mixer, the mixer is also provided with an alkali solution inlet, the discharge port of the mixer is connected to the feed port of the first annular reactor, and the feed port of the first annular reactor is the feed port of the first vertical tubular reactor.

[0038] The first vertical tubular reactor is also provided with a reaction chamber, a stirring shaft and a heat exchange jacket in the first annular reactor; the formaldehyde aqueous solution inlet of the first vertical tubular reactor is arranged on a rotary joint, the rotary joint is connected to the stirring shaft, the stirring shaft is provided with stirring fins along the axial direction, and the stirring shaft and the stirring fins are both hollow and provided with discharge holes; the formaldehyde aqueous solution can be added into the hollow stirring shaft by means of the rotary joint when the stirring shaft rotates, and the formaldehyde aqueous solution entering the stirring shaft flows out through the discharge holes on the stirring shaft and the stirring fins and then enters the reaction chamber of the first vertical tubular reactor, and the formaldehyde aqueous solution entering the reaction chamber and the mixed phenol flowing into the reaction chamber through the feed port of the first vertical tubular reactor undergo a polycondensation reaction under the catalytic action of alkaline solution. The feeding setting of the rotary joint realizes the continuous supply of formaldehyde aqueous solution. The discharge holes on the stirring shaft and stirring fins can make the formaldehyde aqueous solution flow out at different heights and planes, realizing the continuous dispersed feeding of formaldehyde aqueous solution, which not only increases the contact area and contact opportunity between formaldehyde and mixed phenol, improves the efficiency of mixing and reaction, but also avoids the problem of more free phenol and free aldehyde caused by reduced contact probability during the reaction process, especially when there is less residual raw material; the interfacial tension between the materials is broken by the stirring shaft and stirring fins, the contact area between the materials is increased, and the coupling of forced mass transfer and heat exchange is realized under the action of the first circulating pump and the first heat exchanger, which not only promotes the transfer of heat, but also accelerates the diffusion rate of reactants and products, which plays a key role in improving the uniformity of molecular weight distribution and consistency of molecular weight of the product phenolic resin. The heat generated during the reaction is transferred through the heat exchange medium in the heat exchange jacket, and the external first heat exchanger is assisted in forced heat exchange, ensuring the safety, efficiency and sustainability of the reaction.

[0039] The first vertical tubular reactor is also provided with at least one circulating liquid outlet, which is located at the bottom of the first vertical tubular reactor and is connected to the feed port of the first circulating pump, and is used to continuously flow out the first circulating liquid, and drive the reaction liquid to flow by gravity, thereby reducing the load on the first circulating pump and other power equipment, reducing the adhesion of phenolic resin on the inner wall of the equipment, and thus reducing energy consumption and production costs; the first vertical tubular reactor is also provided with at least one circulating liquid inlet, which is located at the upper right end of the first vertical tubular reactor and is connected to the discharge port of the first heat exchanger, and is used to continuously add the first circulating liquid flowing out of the discharge port of the first heat exchanger into the first vertical tubular reactor.

[0040] The first circulating pump is used to transport the first circulating liquid flowing out of the circulating liquid outlet of the first vertical tubular reactor to the first heat exchanger, and under the impetus of the first circulating pump, part of the first circulating liquid is transported to the first vertical tubular reactor, and part of the first circulating liquid is transported to the second annular reactor; the second circulating pump is used to transport the second circulating liquid flowing out of the circulating liquid outlet of the second vertical tubular reactor to the second heat exchanger, and under the impetus of the second circulating pump, part of the second circulating liquid is transported to the second vertical tubular reactor, and part of the second circulating liquid is output in the form of products; wherein the first circulating pump and the second circulating pump are preferably centrifugal pumps, rotor pumps or axial flow pumps, and centrifugal pumps are most preferably used.

[0041] The first heat exchanger is provided with at least one feed port, which is connected to the discharge port of the first circulation pump, and is also provided with at least one discharge port, which is connected to the circulating liquid inlet of the first vertical tubular reactor; the second heat exchanger is provided with at least one feed port, which is connected to the discharge port of the second circulation pump, and is also provided with at least one discharge port, which is connected to the circulating liquid inlet of the second vertical tubular reactor.

[0042] The second vertical tubular reactor is also provided with a reaction chamber, a stirring shaft, and a heat exchange jacket. A rotary joint is provided at the upper end of the stirring shaft, and a trimethylolethylethylenediamine inlet is provided on the left side of the rotary joint. The stirring shaft is provided with stirring fins along the axial direction. The stirring shaft and the stirring fins are both hollow and provided with discharge holes. The rotary joint can be used to add trimethylolethylethylenediamine into the hollow stirring shaft when the stirring shaft rotates. The trimethylolethylethylenediamine entering the stirring shaft flows out through the discharge holes on the stirring shaft and the stirring fins and enters the reaction chamber of the second vertical tubular reactor. The prepolymer liquid flowing into the reaction chamber through the feed port of the second vertical tubular reactor continues to undergo polymerization reaction in the reaction chamber, and the mixed phenol and formaldehyde that do not participate in the reaction in the prepolymer liquid react with the trimethylolethylethylenediamine entering the reaction chamber, thereby reducing the content of free phenol and free aldehyde in the phenolic resin, improving the quality of the phenolic resin, improving the color and heat resistance of the phenolic resin, and reducing the release of free phenol and free aldehyde when the phenolic resin is cured, thereby reducing environmental pollution. The feeding setting of the rotary joint realizes the continuous supply of trimethyl hydroxyethyl ethylenediamine. The discharge holes on the stirring shaft and stirring fins can make trimethyl hydroxyethyl ethylenediamine flow out at different heights and planes, realizing the continuous dispersed feeding of trimethyl hydroxyethyl ethylenediamine, which not only increases the contact area and contact opportunity between trimethyl hydroxyethyl ethylenediamine and the prepolymer liquid, but also improves the efficiency of mixing and reaction, and further reduces the content of free phenol and free aldehyde in phenolic resin; the interfacial tension between the materials is broken by the stirring shaft and stirring fins, the contact area between the materials is increased, and the coupling of forced mass transfer and heat exchange is realized under the action of the second circulating pump and the second heat exchanger, which not only promotes the transfer of heat, but also accelerates the diffusion rate of reactants and products, and improves the molecular weight distribution uniformity and molecular weight consistency of the product phenolic resin. The heat generated during the reaction is transferred through the heat exchange medium in the heat exchange jacket, and the external second heat exchanger is assisted to force heat exchange, ensuring the safety, efficiency and sustainability of the reaction.

[0043] The second vertical tubular reactor is provided with at least one prepolymer liquid inlet, which is located at the upper left end of the second vertical tubular reactor and is connected to the prepolymer liquid outlet of the first annular reactor; the second vertical tubular reactor is also provided with at least one circulating liquid outlet, which is located at the bottom of the second vertical tubular reactor and is connected to the feed port of the second circulating pump, and is used to continuously flow out the second circulating liquid, so as to drive the prepolymer liquid to flow by gravity, reduce the load on the second circulating pump and other power equipment, reduce the adhesion of phenolic resin on the inner wall of the equipment, and thus reduce the production cost and energy consumption; the second vertical tubular reactor is also provided with at least one circulating liquid inlet, which is located at the upper right end of the second vertical tubular reactor and is connected to the discharge port of the second heat exchanger.

[0044] The first discharge pipe and the second discharge pipe are provided at the upper end of the reaction chamber of the first vertical tubular reactor, and the third discharge pipe and the fourth discharge pipe are provided at the upper end of the reaction chamber of the second vertical tubular reactor. The first discharge pipe, the second discharge pipe, the third discharge pipe, and the fourth discharge pipe are all hollow and provided with discharge holes. The first discharge pipe, the second discharge pipe, the third discharge pipe, and the fourth discharge pipe are all U-shaped, the bending part of the first discharge pipe is connected to the feed port of the first vertical tubular reactor, the bending part of the second discharge pipe is connected to the circulating liquid inlet of the first vertical tubular reactor, the bending part of the third discharge pipe is connected to the prepolymer liquid inlet of the second vertical tubular reactor, and the bending part of the fourth discharge pipe is connected to the circulating liquid inlet of the second vertical tubular reactor. The first discharge pipe and the second discharge pipe are horizontally opposite, and the third discharge pipe and the fourth discharge pipe are horizontally opposite. Discharging materials through the discharge pipe further promotes the uniform distribution and mixing of materials, avoids the situation of excessively high or low local concentration, thereby improving the reaction efficiency and further improving the uniform distribution of the molecular weight of the phenolic resin.

[0045] The first heat exchanger and the second heat exchanger include a shell side and a tube side, and are preferably shell-and-tube heat exchangers, plate heat exchangers, or shell-and-tube heat exchangers. More preferably, the first heat exchanger and the second heat exchanger are shell-and-tube heat exchangers.

[0046] The mixer is provided with at least one mixed phenol inlet and at least one alkali solution inlet, which are used for continuously inputting the mixed phenol and the alkali solution respectively; the mixer is also provided with a discharge port, which is used for continuously outputting the mixed solution to the first vertical tubular reactor; the mixed phenol feed is selected from one of a screw pump and a centrifugal pump, and the alkali solution feed is selected from one of a centrifugal pump, a diaphragm pump and a screw pump; the mixer is provided with a mixing channel and a heat exchange channel, the mixing channel is used to provide a place for the mixed phenol and the alkali solution to react, and the heat exchange medium flowing in the heat exchange channel is used to insulate and heat the mixed solution to prevent the precipitated solids from clogging the mixer or the temperature from suddenly rising to destroy the reaction process and reduce the product quality. The mixer is preferably a micro mixer, a microchannel reactor or a static mixer.

[0047] The outer sides of the mixer, the first vertical tubular reactor and the second vertical tubular reactor are provided with a heat-insulating shell, and the heat-insulating shell is filled with rock wool.

[0048] A spray plug is installed on the discharge hole, and the spray plug has an intermediate column and an annular portion, the inner diameter of the annular portion is larger than the outer diameter of the intermediate column, a gap is provided between the intermediate column and the annular portion, and the annular portion and the intermediate column are connected by a radial member; a thinner spray-like reaction liquid is sprayed from the inside of the agitator through the gap, and because the reaction liquid entering the agitator has a certain pressure, the arrangement of the intermediate column and the annular portion of the spray plug at the discharge hole makes it impossible for all the reaction liquid to be discharged through the discharge hole and can only flow out through the gap between the intermediate column and the annular portion, and the liquid is discharged through the gap under the action of pressure, so that the discharged liquid is in the form of a spray and is more evenly dispersed; in order to further make the dispersion more even, the distance range between the gaps is set to 3-7mm, so that it can be ensured that the reaction liquid in the agitator will not be unable to form a spray due to insufficient pressure due to the excessively large discharge diameter, and will not be unable to be sprayed due to excessive viscosity.

[0049] In the present production method, the viscosity of the material in the first annular reactor is lower than 10cp, and the viscosity of the material in the second annular reactor is between 10-80cp. In order to achieve a better spraying effect, the gap between the middle column and the annular portion of the spray plug in the first annular reactor of the production device is designed to be smaller than the gap between the middle column and the annular portion of the spray plug in the second annular reactor.

[0050] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0051] Please refer to Figure 1 , the present invention provides an implementation manner of a phenolic resin production method and a production device. Example 1

[0052] This embodiment provides a phenolic resin production device, such as Figure 1-Figure 2 As shown: The production device of phenolic resin includes a batching tank 4, a mixer 1, a first annular reactor 2 and a second annular reactor 3 which are connected in series in sequence, wherein the first annular reactor 2 includes a first vertical tubular reactor 21, a first circulation pump 22, and a first heat exchanger 23; the second annular reactor 3 includes a second vertical tubular reactor 31, a second circulation pump 32, and a second heat exchanger 33.

[0053] The batching tank 4 is provided with a phenol inlet, a cresol inlet, a tert-butylphenol inlet and a cardanol inlet, the discharge port of the batching tank 4 is connected to the mixed phenol inlet of the mixer 1, the mixer 1 is also provided with an alkali solution inlet, the discharge port of the mixer 1 is connected to the feed port of the first annular reactor 2, the feed port of the first annular reactor 2 is the feed port of the first vertical tubular reactor 21, in the first annular reactor 2, the formaldehyde aqueous solution inlet of the first vertical tubular reactor 21 is arranged on a rotary joint, the rotary joint is connected to the stirring shaft, the stirring shaft is provided with stirring fins along the axial direction, the stirring shaft and the stirring fins are both hollow and provided with a discharge hole 6, the discharge The hole 6 is provided with a spray plug 5, which has an intermediate column 51 and an annular portion 52. The inner diameter of the annular portion 52 is larger than the outer diameter of the intermediate column 51. The intermediate column 51 is connected to the annular portion 52 through a radial member 53. The spray plug 5 is fixed to the discharge hole 6 through the annular portion 52. There is a gap between the intermediate column 51 and the annular portion 52, and the distance of the gap ranges from 3 to 7 mm. The gap between the intermediate column 51 and the annular portion 52 of the spray plug 5 in the first annular reactor 2 is smaller than the gap between the intermediate column 51 and the annular portion 52 of the spray plug 5 in the second annular reactor 3. The circulating liquid outlet of the first vertical tubular reactor 21 is connected to the outlet of the second vertical tubular reactor 3. The feed inlet of the first circulation pump 22 is connected, the discharge port of the first circulation pump 22 is connected to the feed inlet of the first heat exchanger 23, the discharge port of the first heat exchanger 23 is connected to the circulating liquid inlet of the first vertical tubular reactor 21, the prepolymer liquid outlet of the first annular reactor 2 is located on the connecting pipeline between the first heat exchanger 23 and the first vertical tubular reactor 21, the prepolymer liquid outlet of the first annular reactor 2 is connected to the prepolymer liquid inlet of the second annular reactor 3, the prepolymer liquid inlet of the second annular reactor 3 is the prepolymer liquid inlet of the second vertical tubular reactor 31, and in the second annular reactor 3, the second vertical tubular reactor 31 is connected to the second vertical tubular reactor 31. The trimethylolethylethylenediamine inlet of 31 is arranged on a rotary joint, and the rotary joint is connected to the upper end of the stirring shaft. The stirring shaft is provided with stirring fins along the axial direction. The stirring shaft and the stirring fins are both hollow and provided with a discharge hole 6. The circulating liquid outlet of the second vertical tubular reactor 31 is connected to the feed port of the second circulation pump 32, the discharge port of the second circulation pump 32 is connected to the feed port of the second heat exchanger 33, the discharge port of the second heat exchanger 33 is connected to the circulating liquid inlet of the second vertical tubular reactor 31, and the discharge port of the second annular reactor 3 is located on the connecting pipeline between the second heat exchanger 33 and the second vertical tubular reactor 31. Example 2

[0054] This example uses the production device described in Example 1 to provide a method for producing phenolic resin.

[0055] Phenol, cresol, tert-butylphenol, and cardanol enter the batching tank 4 at flow rates of 0.94 kg / min, 94.11 g / min, 188.22 g / min, and 188.22 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol, and cardanol is 10:1:2:2, and the temperature of the batching tank 4 is controlled to be 70° C. Phenol, cresol, tert-butylphenol, and cardanol are mixed and melted in the batching tank 4 to obtain a mixed phenol, and the mixed phenol and a 40% sodium hydroxide solution are mixed. The mixed solution was transported to the mixer 1 at a flow rate of 1.41 kg / min and 141.17 g / min respectively by a centrifugal pump for mixing to obtain a mixed solution. The mass ratio of the sodium hydroxide solution with a mass concentration of 40% to the mixed phenol was 1:10. The temperature of the mixer was 90°C. After the mixed solution flowed out from the mixer outlet, it entered the first annular reactor 2 through the feed port of the first annular reactor 2. At the same time, the formaldehyde aqueous solution with a mass concentration of 50% entered the first annular reactor 2 at a flow rate of 1.41 kg / min. In the annular reactor 2, the mass ratio of mixed phenol to formaldehyde aqueous solution is 1:1, the reaction temperature of the first annular reactor 2 is controlled to be 80°C, the residence time is 3min, the circulation flow rate of the first circulation pump 22 is 50 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 70.58kg / min. After the reaction is completed, the prepolymer liquid enters the second annular reactor 3 through the outlet of the first annular reactor 2. At the same time, trimethylhydroxyethylethylenediamine enters the second annular reactor 3 at a flow rate of 141.17g / min, wherein the mass ratio of trimethylhydroxyethylethylenediamine to mixed phenol is 0.1:1, the reaction temperature of the second annular reactor 3 is controlled to be 120°C, the residence time is 3min, the circulation flow rate of the second circulation pump 32 is 50 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 70.58kg / min. After the reaction is completed, the product phenolic resin is collected from the discharge port of the second annular reactor 3, and the collection is continuous for 20min, and the phenolic resin is sent for sampling and detection. Example 3

[0056] This example uses the production device described in Example 1 to provide a method for producing phenolic resin.

[0057] Phenol, cresol, tert-butylphenol and cardanol enter the batching tank 4 at flow rates of 0.94 kg / min, 188.22 g / min, 141.17 g / min and 150.58 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:2:1.5:1.6, the temperature of the batching tank 4 is controlled to be 60°C, phenol, cresol, tert-butylphenol and cardanol are mixed and melted in the batching tank 4 to obtain a mixed phenol, and the mixed phenol and 35% hydroxide by mass concentration are mixed. The sodium solution was transported to the mixer 1 at a flow rate of 1.42 kg / min and 236.84 g / min respectively by a centrifugal pump to mix and obtain a mixed solution. The mass ratio of the 35% sodium hydroxide solution to the mixed phenol was 1:6. The temperature of the mixer 1 was 75°C. After the mixed solution flowed out of the mixer 1 discharge port, it entered the first annular reactor 2 through the feed port of the first annular reactor 2. At the same time, the 45% formaldehyde aqueous solution entered the first annular reactor 2 at a flow rate of 2.27 kg / min. In the annular reactor 2, the mass ratio of mixed phenol to formaldehyde aqueous solution is 1:1.6, the reaction temperature of the first annular reactor 2 is controlled to be 70°C, the residence time is 10min, the circulation flow rate of the first circulation pump 22 is 30 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 42.63kg / min. After the reaction is completed, the prepolymer liquid enters the second annular reactor 3 through the outlet of the first annular reactor 2. At the same time, trimethylhydroxyethylethylenediamine enters the second annular reactor 3 at a flow rate of 423.32g / min, wherein the mass ratio of trimethylhydroxyethylethylenediamine to mixed phenol is 0.3:1, the reaction temperature of the second annular reactor 3 is controlled to be 105°C, the residence time is 10min, the circulation flow rate of the second circulation pump 32 is 30 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 42.63kg / min. After the reaction is completed, the product phenolic resin is collected from the discharge port of the second annular reactor 3, and the collection is continuous for 20min, and the phenolic resin is sent for sampling and detection. Example 4

[0058] This example uses the production device described in Example 1 to provide a method for producing phenolic resin.

[0059] Phenol, cresol, tert-butylphenol and cardanol enter the batching tank 4 at flow rates of 0.94 kg / min, 235.28 g / min, 112.93 g / min and 112.93 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:2.5:1.2:1.2, the temperature of the batching tank 4 is controlled to be 55°C, phenol, cresol, tert-butylphenol and cardanol are mixed and melted in the batching tank 4 to obtain a mixed phenol, and the mixed phenol and 35% hydrogen by mass concentration are mixed. The sodium hydroxide solution was transported to the mixer 1 at a flow rate of 1.40 kg / min and 280.45 g / min respectively by a centrifugal pump to mix and obtain a mixed solution. The mass ratio of the 35% sodium hydroxide solution to the mixed phenol was 1:5. The temperature of the mixer 1 was 70°C. After the mixed solution flowed out from the discharge port of the mixer 1, it entered the first annular reactor 2 through the feed port of the first annular reactor 2. At the same time, the 40% formaldehyde aqueous solution entered at a flow rate of 2.52 kg / min. In the first annular reactor 2, the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1:1.8, the reaction temperature of the first annular reactor 2 is controlled to be 65°C, the residence time is 3min, the circulation flow rate of the first circulation pump 22 is 20 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 28.04kg / min. After the reaction is completed, the prepolymer liquid enters the second annular reactor 3 through the outlet of the first annular reactor 2. At the same time, trimethylhydroxyethylethylenediamine enters the second annular reactor 3 at a flow rate of 560.90g / min, wherein the mass ratio of trimethylhydroxyethylethylenediamine to the mixed phenol is 0.4:1, the reaction temperature of the second annular reactor 3 is controlled to be 100°C, the residence time is 2min, the circulation flow rate of the second circulation pump 32 is 20 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 28.04kg / min. After the reaction is completed, the product phenolic resin is collected from the discharge port of the second annular reactor 3, and the collection is continuous for 20min, and the phenolic resin is sent for sampling and detection. Example 5

[0060] This example uses the production device described in Example 1 to provide a method for producing phenolic resin.

[0061] Phenol, cresol, tert-butylphenol, and cardanol enter the batching tank 4 at flow rates of 0.94 kg / min, 282.33 g / min, 94.11 g / min, and 94.11 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol, and cardanol is 10:3:1:1, and the temperature of the batching tank 4 is controlled to be 50° C. Phenol, cresol, tert-butylphenol, and cardanol are mixed and melted in the batching tank 4 to obtain a mixed phenol, and the mixed phenol and a 30% sodium hydroxide solution are mixed. The mixed solution was transported to the mixer 1 at a flow rate of 1.41 kg / min and 470.55 g / min respectively by a centrifugal pump for mixing to obtain a mixed solution. The mass ratio of the 30% sodium hydroxide solution to the mixed phenol was 1:3. The temperature of the mixer 1 was 50°C. After the mixed solution flowed out of the mixer 1 discharge port, it entered the first annular reactor 2 through the feed port of the first annular reactor 2. At the same time, the 37% formaldehyde aqueous solution entered the first annular reactor 2 at a flow rate of 2.82 kg / min. shaped reactor 2, wherein the mass ratio of mixed phenol to formaldehyde aqueous solution is 1:2, the reaction temperature of the first annular reactor 2 is controlled to be 60°C, the residence time is 7min, the circulation flow rate of the first circulation pump 22 is 10 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 14.12kg / min. After the reaction is completed, the prepolymer liquid outlet of the first annular reactor 2 enters the second annular reactor 3, and at the same time, trimethylhydroxyethylethylenediamine enters the second annular reactor 3 at a flow rate of 705.83g / min, wherein the mass ratio of trimethylhydroxyethylethylenediamine to mixed phenol is 0.5:1, the reaction temperature of the second annular reactor 3 is controlled to be 90°C, the residence time is 3min, the circulation flow rate of the second circulation pump 32 is 10 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 14.12kg / min. After the reaction is completed, the product phenolic resin is collected from the discharge port of the second annular reactor 3, and the collection is continuous for 20min, and the phenolic resin is sent for sampling and detection. Example 6

[0062] This example uses the production device described in Example 1 to provide a method for producing phenolic resin.

[0063] Phenol, cresol, tert-butylphenol and cardanol enter the batching tank 4 at flow rates of 0.94 kg / min, 141.17 g / min, 169.40 g / min and 169.40 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:1.5:1.8:1.8, the temperature of the batching tank 4 is controlled to be 65°C, phenol, cresol, tert-butylphenol and cardanol are mixed and melted in the batching tank 4 to obtain a mixed phenol, and the mixed phenol and 35% hydrogen peroxide by mass concentration are mixed. The sodium hydroxide solution is transported to the mixer 1 at a flow rate of 1.42 kg / min and 203.01 g / min respectively through a centrifugal pump to mix and obtain a mixed solution. The mass ratio of the 35% sodium hydroxide solution to the mixed phenol is 1:7. The temperature of the mixer is 80°C. After the mixed solution flows out of the discharge port of the mixer 1, it enters the first annular reactor 2 through the feed port of the first annular reactor 2. At the same time, the 50% formaldehyde aqueous solution enters the first annular reactor 2 at a flow rate of 1.99 kg / min. In a ring reactor 2, the mass ratio of mixed phenol to formaldehyde aqueous solution is 1:1.4, the reaction temperature of the first ring reactor 2 is controlled to be 75°C, the residence time is 8min, the circulation flow rate of the first circulation pump 22 is 40 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 56.84kg / min. After the reaction is completed, the prepolymer liquid enters the second ring reactor 3 through the outlet of the first ring reactor 2. At the same time, trimethylhydroxyethylethylenediamine enters the second ring reactor 3 at a flow rate of 284.21g / min, wherein the mass ratio of trimethylhydroxyethylethylenediamine to mixed phenol is 0.2:1, the reaction temperature of the second ring reactor 3 is controlled to be 110°C, the residence time is 7min, the circulation flow rate of the second circulation pump 32 is 40 times the sum of the mixed phenol feed flow rates, and the circulation flow rate is 56.84kg / min. After the reaction is completed, the product phenolic resin is collected from the discharge port of the second ring reactor 3, and the collection is continuous for 20min, and the phenolic resin is sent for sampling and detection.

[0064] Comparative Example 1 The difference between the production device used in this embodiment and the production device described in Example 1 is that the ordinary two-stage series-connected tubular reactor replaces the two-stage series-connected annular reactor.

[0065] Phenol, cresol, tert-butylphenol and cardanol enter the batching tank at flow rates of 0.94 kg / min, 188.22 g / min, 141.17 g / min and 150.58 g / min, respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:2:1.5:1.6, the temperature of the batching tank is controlled to be 60°C, phenol, cresol, tert-butylphenol and cardanol are mixed and melted in the batching tank to obtain a mixed phenol, the mixed phenol and a 35% sodium hydroxide solution are transported to a mixer at flow rates of 1.42 kg / min and 236.84 g / min, respectively, by a centrifugal pump to mix and obtain a mixed solution, the mass ratio of the 35% sodium hydroxide solution to the mixed phenol is 1:6, and the temperature of the mixer is 40°C. The temperature is 75°C. After the mixed liquid flows out from the mixer outlet, it enters the first tubular reactor through the feed port of the first tubular reactor. At the same time, a 45% formaldehyde aqueous solution enters the first tubular reactor at a flow rate of 2.27 kg / min, wherein the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1:1.6. The reaction temperature of the first tubular reactor is controlled to be 70°C, and the residence time is 10 min. After the reaction is completed, the prepolymer liquid enters the second tubular reactor through the outlet of the first tubular reactor. The reaction temperature of the second tubular reactor is controlled to be 105°C, and the residence time is 10 min. After the reaction is completed, the product phenolic resin is collected from the outlet of the second tubular reactor for 20 minutes. The collection is continuous and the phenolic resin is sent for sampling and testing.

[0066] Comparative Example 2 Phenol, cresol, tert-butylphenol and cardanol were fed into the reactor at a feeding amount of 18.82kg, 3.76kg, 2.82kg and 3.01kg respectively, wherein the mass ratio of phenol, cresol, tert-butylphenol and cardanol was 10:2:1.5:1.6, and the temperature of the reactor was controlled to be 75°C. After phenol, cresol, tert-butylphenol and cardanol were mixed and melted in the reactor, 4.74kg of 35% sodium hydroxide solution was added, and the mass ratio of 35% sodium hydroxide solution to mixed phenol was 1:6. After mixing evenly, 45.47kg of 45% formaldehyde aqueous solution was added, wherein the mass ratio of mixed phenol to formaldehyde aqueous solution was 1:1.6. The temperature of the reactor was controlled to be 70°C, the reaction time was 1.5h, and then the temperature of the reactor was controlled to be 105°C. After reacting for 1.5h, the sample was sent for testing of phenolic resin.

[0067] The test results of Examples 2-6 and Comparative Examples 1-2:

[0068] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for producing a phenolic resin, characterized in that: The following steps are involved: S1, adding phenol, cresol, tert-butylphenol and cardanol into a mixing tank and mixing them evenly to form a mixed phenol; S2, the mixed phenol and the alkali solution enter into a mixer and are mixed to obtain a mixed solution; S3, the mixed solution and the formaldehyde aqueous solution enter the first annular reactor to react to obtain a prepolymer solution; S4, the prepolymer solution and trimethylolethylethylenediamine enter the second annular reactor to continue reacting to obtain a phenolic resin; The cresol is a mixture of one or more of o-cresol, m-cresol and p-cresol, and the tert-butylphenol is a mixture of one or more of o-tert-butylphenol, m-tert-butylphenol and p-tert-butylphenol; The batching tank, the mixer, the first annular reactor and the second annular reactor are connected in sequence; the first annular reactor comprises a first vertical tubular reactor, a first circulation pump and a first heat exchanger; the second annular reactor comprises a second vertical tubular reactor, a second circulation pump and a second heat exchanger; the first annular reactor and the second annular reactor are provided with a stirrer; and the reaction time is 5 to 20 minutes.

2. The method for producing a phenolic resin according to claim 1, characterized in that: The mass ratio of phenol, cresol, tert-butylphenol and cardanol is 10:(1-3):(1-2):(1-2); the temperature of the batching tank is controlled at 50-70°C.

3. The method for producing a phenolic resin according to claim 1, characterized in that: The alkali solution is a sodium hydroxide solution with a mass concentration of 30-40%, and the mass ratio of the alkali solution to the mixed phenol is 1:(3-10); the temperature of the mixer is 50-90°C.

4. The method for producing a phenolic resin according to claim 1, characterized in that: The mass concentration of the formaldehyde aqueous solution is 37-50%; the mass ratio of the mixed phenol to the formaldehyde aqueous solution is 1:(1-2); The agitator is provided with a discharge hole, and the formaldehyde aqueous solution is added into the first annular reactor through the discharge hole; a spray plug is installed on the discharge hole, and the spray plug has an intermediate column and an annular portion, a gap is formed between the annular portion and the intermediate column, and the formaldehyde aqueous solution is sprayed out through the gap; the reaction temperature of the first annular reactor is 60~80℃.

5. The method for producing a phenolic resin according to claim 4, characterized in that: The mass ratio of trimethylolethylethylenediamine to mixed phenol is (0.1-0.5):1; the trimethylolethylethylenediamine is added into the second annular reactor through an agitator and a discharge hole on the agitator; a spray plug is installed on the discharge hole, the spray plug has an intermediate column and an annular portion, a gap is formed between the annular portion and the intermediate column, and the trimethylolethylethylenediamine is sprayed out through the gap; the gap between the intermediate column and the annular portion of the spray plug in the first annular reactor is smaller than the gap between the intermediate column and the annular portion of the spray plug in the second annular reactor; the reaction temperature of the second annular reactor is 90-120°C.

6. A phenolic resin production device, characterized in that: The production device comprises A batching tank, wherein the batching tank has a phenol inlet, a cresol inlet, a tert-butylphenol inlet, and a cardanol inlet, and is used to mix phenol, cresol, tert-butylphenol, and cardanol to form a mixed phenol; A mixer, wherein the mixer is provided with a mixed phenol inlet and an alkali solution inlet, and the mixer is used to mix the mixed phenol with the alkali solution; The first annular reactor comprises a first vertical tubular reactor, a first circulation pump and a first heat exchanger which are interconnected; the first annular reactor is used for the mixed liquid to react with the formaldehyde aqueous solution to form a prepolymer liquid; The second annular reactor comprises a second vertical tubular reactor, a second circulation pump and a second heat exchanger which are interconnected; the second annular reactor is used for reacting the prepolymer liquid with trimethylolethylethylenediamine to generate phenolic resin; The batching tank, the mixer, the first annular reactor and the second annular reactor are connected in series in sequence; The first vertical tubular reactor and the second vertical tubular reactor are provided with a stirrer; the stirrer is a hollow structure and is provided with a discharge hole.

7. A phenolic resin production device according to claim 6, characterized in that: The outlet of the mixer is connected to the feed inlet of the first annular reactor; the mixer has mixing and heat exchange functions; The first annular reactor is provided with a prepolymer liquid outlet, and the second annular reactor is provided with a prepolymer liquid inlet; The prepolymer liquid outlet of the first annular reactor is connected to the prepolymer liquid inlet of the second annular reactor.

8. A phenolic resin production device according to claim 6, characterized in that: The upper end of the stirrer is provided with a rotary joint; the rotary joint of the first vertical tubular reactor is provided with an inlet for formaldehyde aqueous solution; the rotary joint of the second vertical tubular reactor is provided with an inlet for trimethylolethylethylenediamine.

9. A phenolic resin production device according to claim 7, characterized in that: The agitator comprises an agitating shaft and agitating fins. A plurality of groups of the agitating fins are arranged axially along the agitating shaft. The agitating fins in the same group are distributed circumferentially along the agitating shaft. The agitating shaft and / or the agitating fins are provided with discharge holes.

10. The phenolic resin production device according to claim 6, characterized in that: A spray plug is installed on the discharge hole. The spray plug has an intermediate column and an annular portion. A gap is formed between the annular portion and the intermediate column. The inner diameter of the annular portion is greater than the outer diameter of the intermediate column. The annular portion and the intermediate column are connected via a radial member.

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