A method for synthesizing phenol-formaldehyde resin for rock wool

Abstract

The present application relates to the field of organic synthesis and chemical separation technology, a method for synthesizing phenolic resin for rock wool, which utilizes the difference in reaction rate of different phenols and formaldehyde, controls the addition sequence of reactants and reaction depth, and systematically makes the high-activity meta-phenol and most of phenol preferentially react with formaldehyde, then weak acid can be added for adjustment; free phenol is removed under reduced pressure and low temperature, solvent is added to remove water, and a small amount of water is added for washing, which is added into the initial solution of polymerized phenolic resin and continues to react with urea to generate phenolic resin polymer for rock wool, and water is added to adjust the viscosity and solid content of the resin; free phenol after water removal is rectified to obtain ortho-methylphenol, para-methylphenol, para-ethylphenol and other ortho-para phenols.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and chemical separation technology, and specifically relates to a method for synthesizing phenolic resin for rock wool. Background Technology

[0002] Phenolic resin, as an important synthetic resin, is widely used in refractory materials, friction materials, electronic packaging, thermal insulation foam materials, and other fields. Its traditional production mainly relies on petrochemical phenol, which is relatively expensive. At the same time, coal chemical industry (such as coal gasification and coal coking) produces a large amount of crude phenol resources as a byproduct. After distillation, it can obtain a mixture of various alkylphenols such as mixed phenols, cresols, xylenols, and tricresols. The market capacity of these mixed alkylphenols is currently limited, the price is low, and there is environmental pressure to treat them. Studies have found that the reactivity of different alkylphenols with formaldehyde varies significantly. For example, the reactivity of "m-cresols", "m-ethylphenols", and "3,5-xylenols" is much higher than that of phenol, while the reactivity of "ortho- and para-cresols" such as "o-cresols", "p-cresols", "p-ethylphenols", "2,6-xylenols", and "2,4-xylenols" is lower. Traditional production of high-purity phenolic resin requires the use of high-purity monophenol raw materials and has strict limits on impurity content. General-purpose or low-to-medium grade phenolic resins (such as those used in rock wool, binders, bakelite powder, etc.) have relatively broad requirements for the molecular weight distribution and specific impurity content of the resin, and pay more attention to indicators such as cost, solid content and residual carbon. In the existing technology, although there are reports of using specific high-purity alkylphenols to produce high-end phenolic resins and by-products of single high-purity phenols, the raw material requirements are high and the process is complex, making it difficult to process the large amount of cheap mixed alkylphenols generated by coal chemical industry on a large scale.

[0003] Northwest Yongxin Coatings Co., Ltd. disclosed in CN201910371885.9 a method for preparing ≤a waterborne rock wool adhesive phenolic resin≥. The method includes the following steps: A. Phenol and formaldehyde solution undergo a condensation reaction under the condition of a catalyst to obtain pure phenolic resin raw material. The formaldehyde solution and catalyst are added in two parts. First, phenol and catalyst are added to the reactor and heated to melt into a liquid state. A large amount of formaldehyde solution is added for the first time, the temperature is raised to 50-60℃, and the reaction is stirred for 90-180 min. The catalyst is added for the second time, the temperature is raised to 65-70℃, and the reaction is continued to be stirred for 30-120 min. Finally, the remaining formaldehyde solution is added, the temperature is raised to 80-90℃, and the reaction is continued to be stirred for 30-60 min at a constant temperature. B. Modifier and diluent are added to the pure phenolic resin raw material obtained in step A to obtain waterborne rock wool adhesive phenolic resin. This invention uses high-content phenol raw materials, with phenol mainly derived from the petrochemical industry. In contrast, this invention utilizes crude phenol, a byproduct of coal gasification and coal liquefaction processes in the coal chemical industry. The crude phenol is refined to obtain coal-derived phenol, mixed phenol (mainly phenol and o-cresol), o-cresol fraction (o-cresol, phenol, etc.), crude 2,6-xylenol (containing 2,6-xylenol, o-cresol, etc.), cresol (mainly m-p-cresol, o-cresol, phenol, 2,4 / 2,5-xylenol, phenol, 2,6-xylenol, etc., with m-cresol content 20-45%), and m-p-cresol (mainly m-p-cresol, also containing o-cresol). The invention utilizes phenolic materials such as 2,4 / 2,5-xylenol, phenol, 2,6-xylenol, and mixed xylenol to partially or completely replace petrochemical phenol, instead of using only pure phenol. When producing phenolic resin for rock wool, byproducts such as o-cresol, p-cresol, p-ethylphenol, and 2,4-xylenol can also be considered. Furthermore, the invention can use weak acids such as boric acid, phosphoric acid, and acetic acid to improve the resin's color, thermal stability, and flame retardant properties. During the dehydration and recovery of free phenol from the phenolic resin concentrate, the invention helps prevent excessive polymerization of the resin, which is beneficial for maintaining resin performance. Simultaneously, it helps reduce the free phenol content in the phenolic resin for rock wool, which is environmentally friendly.

[0004] Therefore, developing an integrated process that can utilize inexpensive mixed alkylphenols with complex compositions to partially or completely replace phenol, while efficiently separating and purifying various high-priced ortho- and para-alkylphenols during the production of qualified phenolic resins, has significant economic and environmental value. Summary of the Invention

[0005] The purpose of this invention is to provide a method for synthesizing phenolic resin for rock wool, using inexpensive coal-based phenol, mixed phenols, and various coal-based mixed alkylphenols (such as cresol, m-p-cresol, 2,4 / 2,5-xylenol, m-p-ethylphenol, 2,4,6-trimethylphenol, m-p-isopropylphenol, etc., including commercially available low-grade phenol, 25-35% cresol, 45% m-p-cresol, 90% or 95% m-p-cresol, industrial xylenol, mixed m-p-ethylphenol, etc., and also including mixed phenols, o-cresol fractions, etc.). The phenolic resin for rock wool can be produced by partially or completely replacing petrochemical phenol with intermediate products such as 2,6-xylenol fraction, 2,4 / 2,5-xylenol, 2,4 / 2,5-methylethylphenol, and mixtures of different types and proportions. By utilizing the differences in reactivity of different phenols and controlling the reaction process and subsequent separation and purification, high-purity phenol, o-cresol, 2,6-xylenol, p-cresol, p-ethylphenol, 2,4-xylenol, p-isopropylphenol, and other high-value products can be produced.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] Step 1: Phenolic Resin Synthesis

[0008] Add the first phenolic component to the reactor, then add a portion of the second phenolic component. Add an alkaline catalyst (1-10% of the total phenolic material) and a portion of aldehydes to the reactor. After the phenols and alkaline catalyst have been added, heat the reactor to 40-80°C and react for 1-4 hours. Continue heating to 50-90°C and add the remaining aldehydes and the remaining second component dropwise to the reactor over 1-4 hours. After the addition is complete, maintain the reactor temperature at 60-150°C for 1-6 hours. After sampling and analysis, if the free phenol content is ≤15%, quickly cool down to 60°C and add a weak acid as a modifier and stabilizer.

[0009] Step 2: Recovery of free phenols

[0010] Open the valve of the reflux separator on the reactor, gradually open the vacuum to remove free phenol, control the dehydration at low temperature (-0.08~-0.1MPa), and the dehydration temperature ≤60℃. Let the distilled liquid stand in the separator, continuously separating the lower layer of free phenol, and return the upper layer of water to the polymerization reactor; the free phenol removal time is 1~4 hours, and sampling and analysis should begin 1~2 hours after the free phenol removal, requiring free phenol ≤2%; the separated free phenol is purified by distillation in the fourth step.

[0011] Step 3: Synthesis of phenolic resin for rock wool

[0012] After the free phenol is qualified, urea and the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 20-80℃, and the mixture is stirred and reacted for 1-4 hours. Sampling and analysis are performed: pH 7.5-9.5, free phenol ≤2%, free aldehyde ≤1% are qualified. Water is added under stirring to adjust the viscosity and solid content. Sampling and analysis are performed: solid content 38-45%, pH 7.5-9.5, viscosity ≤12mpa.s / 25℃, free phenol ≤2%, free aldehyde ≤1%.

[0013] The material can be discharged after the temperature drops below 40℃ to obtain a light yellow to brownish-red transparent phenolic resin for rock wool.

[0014] Step 4: Recovery of ortho- and para-alkylphenols

[0015] Extract the free phenol obtained from the second distillation step by adding 0.5 to 2 times its volume of a non-water-soluble solvent. Allow it to stand to separate the lower layer of water. Wash the solvent layer once with water (0.1 to 0.5 times the mass of the non-water-soluble solvent). Return the separated water to the polymerization reactor and combine it with the phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 5 to 50 trays. Distill under normal pressure and then under reduced pressure (-0.03 to -0.07 MPa, reflux ratio 1 to 5) to remove the solvent and reuse the solution. Then, perform the following treatment:

[0016] The material in the distillation vessel is transferred to a high-efficiency distillation vessel with 100 to 300 trays, and the material is distilled under reduced pressure to obtain at least one of the following: 99.5% o-cresol, 99% 2,6-xylenol, 98% p-cresol or p-cresol / o-ethylphenol, 90% 2,4-xylenol, 98% p-ethylphenol or p-ethylphenol / 2,3-xylenol, 2,4,6-trimethylphenol, 2,4-methylethylphenol, 2,3,6-trimethylphenol, p-isopropylphenol, or p-isopropyl / p-propylphenol.

[0017] Through the above scheme, under alkaline catalysis, the reaction rate difference between different phenols and formaldehyde is utilized. By controlling the order of reactant addition and the reaction depth, highly reactive meta-phenols and most phenols are preferentially reacted with formaldehyde to generate phenolic resin polymers. Meanwhile, less reactive ortho- and para-alkylphenols are mostly retained in the unreacted products due to their slow reaction. During the dehydration process, these unreacted phenols are distilled off along with water, achieving preliminary separation from the resin product. The distilled aqueous phase is allowed to stand and separate into layers. The aqueous layer is returned to the polymerization reactor and reacted with urea along with the resin stock. The oil layer is dehydrated by adding a non-water-soluble solvent, washed, and distilled to obtain high-grade ortho- and para-alkylphenol products or mixtures thereof.

[0018] Preferably, the objective of this invention can also be achieved through the following technical solutions:

[0019] Step 1: Phenolic Resin Synthesis

[0020] Add the first phenolic component to the reactor, followed by a portion of the second phenolic component. Add an alkaline catalyst (1-10% of the total phenolic material) and a portion of aldehydes to the reactor. After the phenols and alkaline catalyst have been added, heat the reactor to 40-80°C and react for 1-4 hours. Continue heating to 50-90°C and add the remaining aldehydes and the remaining second component dropwise to the reactor over 1-4 hours. After the addition is complete, maintain the reactor temperature at 60-150°C for 1-6 hours. After sampling and analysis, ensure that the free phenol content is ≤1.5%. Then, rapidly cool the reactor to 60°C. A weak acid can be added as a modifier and stabilizer.

[0021] Step 2: Synthesis of phenolic resin for rock wool

[0022] After the free phenol is qualified, add urea when the temperature inside the reactor is controlled at 20-80℃, and stir for 1-4 hours. Take samples for analysis: pH 7.5-9.5, free phenol ≤1.5%, free aldehyde ≤1% are qualified. Add water under stirring to adjust the viscosity and solid content. Take samples for analysis: solid content 38-45%, pH 7.5-9.5, viscosity ≤12mpa.s / 25℃, free phenol ≤1.5%, free aldehyde ≤1%.

[0023] The material can be discharged after the temperature drops below 40℃ to obtain a light yellow to brownish-red transparent phenolic resin for rock wool.

[0024] More preferably, the objective of this invention can also be achieved through the following technical solutions:

[0025] Step 1: Phenolic Resin Synthesis

[0026] Add the first phenolic component to a medium-pressure reactor, followed by a portion of the second phenolic component. Add an alkaline catalyst (1-10% of the total phenolic material) and a portion of aldehydes to the reactor. After the phenols and alkaline catalyst have been added, heat the reactor to 40-80°C and react for 1-4 hours. Continue heating to 50-90°C and add the remaining aldehydes and the remaining second component dropwise over 1-4 hours. After the addition is complete, maintain the reactor temperature at 60-105°C for 1-6 hours, then heat to 105-150°C for 1-3 hours. After sampling and analysis, ensure that the free phenol content is ≤1%. Then, rapidly cool the reactor to 60°C. A weak acid can be added as a modifier and stabilizer.

[0027] Step 2: Synthesis of phenolic resin for rock wool

[0028] After the free phenol is qualified, urea is added when the temperature inside the reactor is controlled at 20-80℃, and the reaction is stirred for 1-4 hours. Sampling and analysis are performed: pH 7.5-9.5, free phenol ≤1%, free aldehyde ≤1% are qualified. Water is added under stirring to adjust the viscosity and solid content. Sampling and analysis are performed: solid content 38-45%, pH 7.5-9.5, viscosity ≤12mpa.s / 25℃, free phenol ≤1%, free aldehyde ≤1%.

[0029] The material can be discharged after the temperature drops below 40℃ to obtain a light yellow to brownish-red transparent phenolic resin for rock wool.

[0030] Further, the first phenolic component is phenol or a mixture of phenols; the phenol contains ≥90% phenol and ≤10% o-cresol; the mixture of phenols is composed of phenol and o-cresol, wherein the o-cresol content is 10-50% and the phenol content is 50-90%, and may also contain 0-40% m-p-cresol, 0-10% 2,6-xylenol and 0-5% 2,4 / 2,5-xylenol.

[0031] Further, the second phenolic component is selected from at least one of o-cresol fraction, cresol, 2,6-xylenol, m-p-cresol, 2,4 / 2,5-xylenol, m-p-ethylphenol, 2,4,6-trimethylphenol, 2,4 / 2,5-methylethylphenol, 3,4-xylenol / 2,3,6-trimethylphenol, m-p-propylphenol / isopropylphenol, or a mixture of two or more thereof; and the second phenolic component is obtained by distillation of crude phenol extracted from coal coking crude phenol, medium-low temperature coal gasification crude phenol, or crude phenol extracted from phenol-containing coal tar by coal pyrolysis.

[0032] Preferably, the o-cresol fraction contains: phenol 0-50%, o-cresol 50-95%, 2,6-xylenol 0-30%, and m-p-cresol 0-40%.

[0033] Preferred cresol composition: m-p-cresol 40-70%, o-ethylphenol 0-8%, phenol 5-25%, o-cresol 10-35%, 2,6-xylenol 0.5-20%, 2,4 / 2,5-xylenol 0-20%, 2-ethyl-6-cresol 0-5%, o-isopropylphenol 0-5%;

[0034] Preferred, 2,6-xylenol: m-p-cresol 0-50%, o-ethylphenol 0-6%, phenol 0-10%, o-cresol 0-50%, 2,6-xylenol 50-95%, 2,4 / 2,5-xylenol 0-10%, 2-ethyl-6-cresol 0-5%;

[0035] Preferred, m-p-cresol: m-p-cresol 70-100%, o-ethylphenol 0-12%, o-cresol 0-15%, 2,6-xylenol 0-15%, 2,4 / 2,5-xylenol 0-15%, 2-ethyl-6-cresol 0-10%, o-isopropylphenol 0-5%;

[0036] Preferably, 2,4 / 2,5-xylenol comprises: m-p-cresol 0-15%, o-ethylphenol 0-2%, 2,4 / 2,5-xylenol 70-100%, 2-ethyl-6-cresol 0-10%, o-isopropylphenol 0-5%, and 2,3-xylenol 0-30%.

[0037] Preferred ingredients: 2,3-xylenol / m-xylenol / 3,5-xylenol 80-100%, 3,5-xylenol 0-30%, 2,4 / 2,5-methylethylphenol 0-10%, 2,4 / 2,5-xylenol 0-10%, 2,4,6-trimethylphenol 0-10%, o-isopropylphenol 0-5%;

[0038] Preferably, 2,4,6-trimethylphenol; 10-40% of 2,4,6-trimethylphenol, 50-90% of 2,4,6-trimethylphenol, 10-30% of 3,5-xylenol, 0-30% of 2,4 / 2,5-methylethylphenol, and 0-10% of 3,4-xylenol;

[0039] Preferred composition: 2,4 / 2,5-methylethylphenol: 60-100% 2,4 / 2,5-methylethylphenol, 0-30% 3,5-xylenol, 0-20% m-p-ethylphenol, 0-30% 3,4-xylenol, and 0-10% 2,3,6-trimethylphenol;

[0040] Preferred composition: 3,4-xylenol / 2,3,6-trimethylphenol: 2,4 / 2,5-methylethylphenol 0-20%, 3,5-xylenol 0-10%, m-p-ethylphenol 0-10%, 3,4-xylenol 30-80%, 2,3,6-trimethylphenol 5-50%, m-p-isopropylphenol 0-30%;

[0041] Preferred components include: 2,3-methylethylphenol / m-isopropylphenol / m-propylphenol / 3-ethyl-5-methylphenol 80-100%, 3,4-xylenol 0-15%, 2,3,5-trimethylphenol 0-5%, 2,4 / 2,5-methylethylphenol 0-5%, 2,4,5-trimethylphenol 0-10%, and 2,3,6-trimethylphenol 0-5%.

[0042] Further, the mass ratio of the first phenolic component to the second phenolic component is 0:100 to 100:0, preferably 50:50 to 80:20; a portion of the second phenolic component accounts for 0 to 100% of its total mass, preferably 30 to 70%.

[0043] Further, the alkaline catalyst is an aqueous solution of sodium hydroxide, potassium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, sodium monohydrogen phosphate, trisodium phosphate, or ammonia; the aldehyde is an aqueous solution of formaldehyde, paraformaldehyde, or acetaldehyde; the amount of aldehyde used is phenol, meta-alkylphenol (including m-cresol, m-ethylphenol, m-isopropylphenol, m-propylphenol), meta-para-alkylphenol (including 3,4-xylenol, 3,4-methylethylphenol, 3,4-diethylphenol, 3,4-methylpropylphenol), and meta-ortho-alkylphenol (including 2,3-xylenol, 2,5-xylenol) from the phenolic materials. The total molar amount of phenols, 2,3-methylethylphenol, 2,5-methylethylphenol, 2,3-methylpropylphenol, 2,5-methylpropylphenol, meta- and meta-alkylphenols (including 3,5-xylenol, 3-ethyl-5-methylphenol, 3,5-diethylphenol), and meta- and ortho-alkylphenols (2,3,5-trimethylphenol, 2-ethyl-3,5-xylenol, 3-ethyl-2,5-xylenol, 5-ethyl-2,3-xylenol) is 1 to 8 times, preferably 2 to 5 times; the mass of the aldehyde portion is 0 to 100% of the total aldehyde feed mass, preferably 30 to 70%.

[0044] Furthermore, the weak acid is boric acid, phosphoric acid, acetic acid, formic acid, etc., preferably boric acid or phosphoric acid, and the amount used is 0-5% of the mass of the phenolic material.

[0045] Furthermore, the amount of urea used is 0.01 to 1.5 times the mass of the phenolic material, preferably 0.1 to 0.8 times.

[0046] Furthermore, the non-water-soluble solvent is an aromatic hydrocarbon, a chloroalkanes, an ether, or an ester, preferably toluene or methyl isobutyl ether; the amount of solvent used is 0.5 to 2 times the mass of the free phenol.

[0047] Furthermore, the high-efficiency vacuum distillation conditions are: pressure -0.07 to -0.1 MPa, reflux ratio 5 to 50, and number of trays 100 to 300.

[0048] The beneficial effects of this invention are:

[0049] 1. Significant economic benefits: Using inexpensive coal-based phenols, mixed phenols, and various coal-based mixed alkylphenols to partially replace the more expensive petrochemical phenols as raw materials significantly reduces the production cost of phenolic resins. At the same time, by-products such as o-cresol, p-cresol, 2,6-xylenol, p-ethylphenol, 2,4-xylenol, and p-isopropylphenol are all high-purity products with market value far exceeding that of the raw materials, creating additional profit sources and resulting in outstanding overall economic benefits.

[0050] 2. Comprehensive utilization of resources and significant environmental benefits: This invention provides a stable and large-scale high-value utilization pathway for the large quantities of crude phenols and their distillation byproducts (such as mixed cresols, mixed xylenols, and mixed tricresols) generated during coal gasification, coal coking, and coal pyrolysis. It helps solve the sales problem of by-product phenols in the coal chemical industry, reduces the pressure on solid waste and wastewater treatment, and makes a positive contribution to the healthy development of the industry and environmental protection.

[0051] 3. High degree of process integration and flexible and diverse products: Through a set of integrated processes, the synthesis of phenolic resin and the separation of various high-purity alkylphenols are realized simultaneously. The types and ratios of the first and second phenolic components can be flexibly adjusted according to market supply and demand, and the required combination of main and by-products can be produced in a targeted manner, which is highly adaptable.

[0052] 4. Superior product quality and high separation efficiency: The process is controlled by utilizing the difference in reactivity, so that the highly reactive meta-phenols can fully react during the resin synthesis stage, while the less reactive ortho- and para-phenols are enriched in the by-product ortho- and para-alkylphenols through distillation. Subsequently, impurities are removed by adding solvent for dehydration and washing, and combined with efficient distillation, ensuring the high purity of the final alkylphenol product.

[0053] 5. The quality requirements for various phenolic raw materials used are low. Due to the use of multiple methods such as dripping, the presence of 2,6-xylenol, 2-ethyl-6-cresol, 2,4-xylenol, 2,4,6-trimethylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol, and 2-ethyl-4-cresol in phenolic raw materials such as cresol, m-p-cresol, m-p-ethylphenol, and m-p-isopropylphenol is ensured. The hydroxymethylphenol intermediates generated by the reaction of tricresol, 2,4,5-tricresol, and 2-ethyl-4-cresol with formaldehyde preferentially react with m-cresol, m-ethylphenol, m-isopropylphenol, 3,5-xylenol, phenol, etc., to form condensates with a functionality of 2. These condensates further react with formaldehyde and m-alkylphenol, m-paraphenol, m-orthophenol, p-alkylphenol, or o-alkylphenol, etc., to form phenolic resins. This phenolic resin has an increased linear chain segment and an increased alkyl group in the resin molecule, thus improving the resin properties without affecting the properties of the phenolic resin.

[0054] 6. Improve resin performance: Introducing alkylphenol units with different structures (such as rigid meta-phenol and flexible ortho- and para-phenol) into the phenolic resin molecular chain can adjust and improve the heat resistance, toughness, char residue and other properties of the final resin to a certain extent, thus broadening the application range of the resin.

[0055] 7. After the initial synthesis of phenolic resin, in order to prevent dehydration under strongly alkaline conditions from causing further polymerization of the phenolic resin and affecting its performance, we use methods such as adding appropriate amounts of boric acid, a small amount of phosphoric acid or weak organic acid to control the pH value, and dehydrating under reduced pressure at low temperature. This can effectively reduce the deep polymerization of the resin, ensure that the resin has good water solubility, and at the same time, change the color of the product solution to a yellow to light red transparent liquid. The addition of boric acid and phosphoric acid can also improve the fire resistance and heat resistance of phenolic resin.

[0056] 8. In the synthesis of phenolic resin for rock wool, we can also control the reaction degree of the initial phenolic resin solution by adjusting the proportions of various phenolic components, the ratio of phenolic components to formaldehyde, the quantity and activity of alkaline catalysts, the synthesis temperature, and the dropping method. When we do not intend to recover the ortho- and para-alkylphenol products, we can quickly achieve a free phenol content of ≤1.5% in the initial resin solution by increasing the catalyst ratio, catalyst activity, and aldehyde-phenol ratio; we can even reduce the free phenol content of the initial resin solution to ≤0.5% by increasing the temperature and pressure; and then modify the free aldehyde by adding urea at a lower temperature and adjusting the viscosity with water, thus achieving the required performance of phenolic resin for rock wool in one step.

[0057] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is a process flow diagram of a synthetic phenolic resin for rock wool according to the present invention (byproduct: ortho- and para-alkylphenols).

[0060] Figure 2 This invention provides a process flow diagram for synthesizing phenolic resin for rock wool and a conventional process flow diagram for synthesizing phenolic resin for rock wool. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Example 1: Production of phenolic resin for rock wool using mixed phenols with o-cresol as a byproduct

[0063] Step 1: Synthesis of Phenolic Resin Stock Solution

[0064] Add 600 parts of coal-derived mixed phenol (containing 429.6 parts of phenol, 149.1 parts of o-cresol, and 21.3 parts of 2,6-xylenol), 200 parts of 31% sodium hydroxide aqueous solution (6.2% of the total mass of phenolic materials), and 770 parts of 36.5% formaldehyde (the total amount of formaldehyde is 3.8 times the molar mass of phenol) to the polymerization reactor. Start stirring, heat, and raise the temperature to 45-50℃. At 60℃, turn on the jacket cooling water to remove the heat of reaction. After reacting for 1 hour, raise the temperature to 70-75℃ and add the remaining 600 parts of formaldehyde dropwise, while simultaneously adding the remaining 400 parts of mixed phenol dropwise. The dropwise addition time is 2 hours. Within 1 hour, the material temperature rises to 85-90℃. Maintain the temperature for 3 hours. Take a sample for analysis. The free phenol content is 3.8%, which is qualified.

[0065] Step 2: Recovery of free phenols

[0066] After the reaction is complete, the temperature is lowered to 50℃. The vacuum is gradually increased to -0.085MPa over 0.5 to 1 hour to begin reflux to remove free phenol. The distilled liquid is returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator is collected in a receiving tank. When the amount of oily material in the removed liquid is low, a sample is taken from the reactor and analyzed. The free phenol removal is stopped when the free phenol content reaches 0.83%. Dehydration should be completed at the lowest possible temperature (≤60℃). 119.2 parts of aqueous free phenol were obtained (including 76.9 parts of o-cresol and 29.5 parts of 2,6-xylenol).

[0067] Step 3: Synthesis of phenolic resin for rock wool

[0068] After the free phenol in the polymerization reactor passed the test, 300 parts of urea and 23.6 parts of the water from the fourth step of the previous batch were added while the reactor temperature was controlled at 50℃. The mixture was stirred and reacted for 2 hours. The results showed that the pH was 9, the free phenol content was 0.21%, and the free aldehyde content was 0.77%, which were within acceptable limits. Then, 930 parts of water were added while stirring to adjust the viscosity and solid content. The results showed that the solid content was 44.11%, the pH was 8.5, the viscosity was 9.5 mPa·s / 25℃, the free phenol content was 0.15%, and the free aldehyde content was 0.75%.

[0069] The material can be discharged after the temperature drops below 40℃, resulting in 3685.9 parts of light brownish-red transparent phenolic resin for rock wool, with a nitrogen content of 3.8%, a refractive index of 1.502, and a curing time of 12 minutes at 130℃.

[0070] Step 4: Recovery of o-cresol

[0071] Add 110 parts by volume of methyl isobutyl ketone to the 119.2 parts of aqueous free phenol obtained from the second distillation, stir for 0.5 hours, let stand, and remove 12.6 parts of the lower water layer. Wash the solvent layer once with 20 parts of water. Return the 32.5 parts of water after the two separations to the polymerization reactor and combine it with the next batch of phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 30 trays, heat to atmospheric pressure, and then distill under reduced pressure (-0.05 MPa, reflux ratio 5) to remove 107.8 parts of solvent for reuse, and then perform the following treatment:

[0072] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays, and distilled at -0.085 MPa and a reflux ratio of 20:1 to obtain 53.1 parts of 99.8% o-cresol and 14.5 parts of 99.5% 2,6-xylenol.

[0073] Example 2: Production of phenolic resin for rock wool using o-cresol fraction, with o-cresol as a byproduct.

[0074] Step 1: Synthesis of Phenolic Resin Stock Solution

[0075] Add 1000 parts of 96.2% coal-derived phenol, 300 parts of o-cresol fraction (containing 66 parts phenol, 189 parts o-cresol, and 45 parts 2,6-xylenol), 480 parts of 25% ammonia (6% of the total mass of phenolic materials), and 2500 parts of 36.5% formaldehyde (the total amount of formaldehyde is 4.0 times the molar mass of phenol) to the polymerization reactor. Start stirring and heat to 45-50℃. At 60℃, turn on the jacket cooling water to remove the heat of reaction. After reacting for 1 hour, add the remaining 1635 parts of formaldehyde dropwise and the remaining 700 parts of o-cresol fraction dropwise over 3 hours. Within 1 hour, the material temperature rises to 85-90℃. Maintain the temperature for 4 hours. Take a sample for analysis. The free phenol content is 3.84%, which is qualified.

[0076] Step 2: Recovery of free phenols

[0077] After the reaction is complete, the temperature is lowered to 50℃, and 30 parts of boric acid and 20 parts of 85% phosphoric acid are added. The vacuum is gradually increased to -0.09MPa over 0.5 to 1 hour to begin reflux to remove free phenol. The distilled liquid is returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator is collected in a free phenol receiving tank. After 2.5 hours of dehydration, when the amount of oily material in the dehydrated liquid is low, a sample is taken from the reactor for analysis. The free phenol content is 0.22%, and the dehydration is stopped. Dehydration should be completed at the lowest possible temperature (≤60℃). 373.1 parts of aqueous free phenol were obtained (including 238.6 parts of o-cresol and 94.5 parts of 2,6-xylenol).

[0078] Step 3: Synthesis of phenolic resin for rock wool

[0079] After the free phenol in the polymerization reactor is qualified, 800 parts of urea and 90.2 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 40℃. The mixture is stirred and reacted for 2 hours. Then, 800 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 42.55%, pH 8.1, viscosity 8.5 mPa·s / 25℃, free phenol 0.17%, and free aldehyde 0.78%.

[0080] The material can be discharged after the temperature drops below 40℃, resulting in 7942.2 parts of light yellow to yellow transparent phenolic resin for rock wool, with a nitrogen content of 4.7%, a refractive index of 1.462, and a curing time of 11 minutes at 130℃.

[0081] Step 4: Recovery of o-cresol and 2,6-xylenol

[0082] Add 350 parts of toluene to the 373.1 parts of aqueous free phenol obtained from the second distillation step, stir for 0.5 hours, let stand, and remove 40.3 parts of the lower water layer. Wash the solvent layer once with 50 parts of water. Return 90.5 parts of water after the two separations to the polymerization reactor and combine it with the next batch of phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 20 trays, heat to atmospheric pressure, and then distill under reduced pressure (-0.05 MPa, reflux ratio 4) to remove 341.8 parts of toluene. Reuse the distillate and then perform the following treatment:

[0083] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 150 trays, and distilled at -0.085 MPa and a reflux ratio of 25:1 to obtain 163.8 parts of 99.6% o-cresol and 56.4 parts of 99.3% 2,6-xylenol.

[0084] Example 3: Using 2,6-xylenol as a raw material to produce phenolic resin for rock wool, with 2,6-xylenol as a byproduct.

[0085] Step 1: Synthesis of Phenolic Resin Stock Solution

[0086] Add the following to the polymerization reactor: 1000 parts of 99.2% coal-derived phenol, 200 parts of crude 2,6-xylenol (containing 35.2 parts of o-cresol, 20.4 parts of p-cresol, 36.9 parts of m-cresol, 0.5 parts of o-ethylphenol, and 107 parts of 2,6-xylenol), 516 parts of 31% liquid alkali (8% of the total mass of phenolic materials), and 2531 parts of 36.5% formaldehyde (the total amount of formaldehyde is 4 times the molar mass of phenol). Start stirring, heat to 45-50℃, and at 60℃, open the jacket cooling water to remove the heat of reaction. After reacting for 1.5 hours, raise the temperature to 75-80℃, add the remaining 1500 parts of formaldehyde and the remaining 800 parts of crude 2,6-xylenol dropwise over 2 hours. Seal the container and raise the temperature of the material to 110-120℃ within 1 hour. Maintain the temperature for 2.5 hours. Take a sample for analysis and the free phenol content is 6.2%, which is qualified.

[0087] Step 2: Recovery of free phenols

[0088] After the reaction is complete, the temperature is lowered to 50℃. The vacuum is gradually increased to -0.095MPa over 0.5 to 1 hour to begin reflux to remove free phenol. The distilled liquid is returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator is collected in a free phenol receiving tank. After 3 hours of dehydration, when the amount of oily material in the dehydrated liquid is low, a sample is taken from the reactor for analysis. The free phenol content is 0.31%, and the dehydration process is considered complete. Dehydration should be completed at the lowest possible temperature (≤50℃). 422.8 parts of aqueous free phenol were obtained (including 14.9 parts of o-cresol, 7.7 parts of p-cresol, and 358.4 parts of 2,6-xylenol).

[0089] Step 3: Synthesis of phenolic resin for rock wool

[0090] After the free phenol in the polymerization reactor is qualified, 600 parts of urea and 91.5 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 30℃. The mixture is stirred and reacted for 2 hours. Then, 300 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 42.41%, pH 9, viscosity 8.8 mPa·s / 25℃, free phenol 0.22%, and free aldehyde 0.83%.

[0091] The material can be discharged after the temperature drops below 40℃, resulting in 7080.1 parts of brownish-red transparent rock wool phenolic resin with a nitrogen content of 3.95%, a refractive index of 1.475, and a curing time of 13 minutes at 130℃.

[0092] Step 4: Recovery of 2,6-xylenol

[0093] Add 400 parts of ethyl acetate to the 422.8 parts of aqueous free phenol obtained from the second distillation step, stir for 0.5 hours, let stand, and remove 41.4 parts of the lower water layer. Wash the solvent layer once with 50 parts of water. Return 91.3 parts of the water after the two separations to the polymerization reactor and combine it with the next batch of phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 20 trays, heat to atmospheric pressure, and then distill under reduced pressure (-0.05 MPa, reflux ratio 5) to remove 393.2 parts of ethyl acetate, which is then reused and subjected to the following treatment:

[0094] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 150 trays, and distilled at -0.085 MPa and a reflux ratio of 25:1 to obtain 283.1 parts of 99.8% 2,6-xylenol.

[0095] Example 4: Using cresol as a raw material to produce phenolic resin for rock wool, with o-cresol, p-cresol, and 2,4-xylenol as byproducts.

[0096] Step 1: Synthesis of Phenolic Resin Stock Solution

[0097] Add 2000 parts of coking cresol (containing 181 parts of phenol, 406 parts of o-cresol, 10 parts of 2,6-xylenol, 458 parts of p-cresol, 824 parts of m-cresol, 2.5 parts of o-ethylphenol, 79.5 parts of 2,4-xylenol, and 39 parts of 2,5-xylenol), 323 parts of 31% liquid alkali, 50 parts of sodium monohydrogen phosphate (7.5% of the total mass of phenolic materials), and 2446 parts of 36.5% formaldehyde to the polymerization reactor. (The total amount of formaldehyde is 4 times the molar mass of phenol). Start stirring, heat, and raise the temperature to 45-50℃. At 60℃, open the jacket and cool with water to remove the heat of reaction. After reacting for 1.5 hours, raise the temperature to 75-80℃ and add the remaining 1000 parts of formaldehyde dropwise over 1.5 hours. Keep the temperature at 90-95℃ for 2.5 hours. Take a sample for analysis. The free phenol content is 6.33%, which is qualified. After the reaction is finished, cool down to 50℃ and add 100 parts of boric acid.

[0098] Step 2: Recovery of free phenols

[0099] The vacuum was gradually increased to -0.09 MPa over 0.5 to 1 hour to begin reflux for free phenol removal. The distilled liquid was returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator was collected in a free phenol receiving tank. After 2.5 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.63%, and the dehydration process was terminated. Dehydration should be completed at the lowest possible temperature (≤60℃). 354.5 parts of aqueous free phenol were obtained (including 131.6 parts of o-cresol, 5.9 parts of 2,6-xylenol, 136.1 parts of p-cresol, 1.3 parts of o-ethylphenol, 47.2 parts of 2,4-xylenol, and 0.2 parts of 2,5-xylenol).

[0100] Step 3: Synthesis of phenolic resin for rock wool

[0101] After the free phenol in the polymerization reactor is qualified, 400 parts of urea and 82.6 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 30℃. The mixture is stirred and reacted for 2 hours. Then, 400 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 42.73%, pH 8, viscosity 8.6 mPa·s / 25℃, free phenol 0.48%, and free aldehyde 0.69%.

[0102] The material can be discharged after the temperature drops below 40℃, resulting in 6414.8 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 2.91%, a refractive index of 1.511, and a curing time of 14 minutes at 130℃.

[0103] Step 4: Recovery of o-cresol, p-cresol, and 2,4-xylenol

[0104] Add 350 parts of toluene to the 354.5 parts of aqueous free phenol obtained from the second distillation step, stir for 0.5 hours, let stand, and remove the lower layer of water (32.3 parts). Wash the solvent layer once with 50 parts of water. Return the 82.8 parts of water after the two separations to the polymerization reactor and combine it with the next batch of phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 20 trays, heat to atmospheric pressure, then reduce pressure (-0.04 MPa, reflux ratio 5) to remove 342.3 parts of toluene, reuse it, and then perform the following treatment:

[0105] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays, and distilled at -0.085 MPa and a reflux ratio of 20:1 to obtain 107.3 parts of 99.6% o-cresol, 105.6 parts of 99.1% p-cresol, and 41.8 parts of 99.5% 2,4-xylenol.

[0106] Example 5: Using m-p-cresol as a raw material to produce phenolic resin for rock wool, with p-cresol and phenol as byproducts.

[0107] Step 1: Synthesis of Phenolic Resin Stock Solution

[0108] In a stainless steel polymerization reactor equipped with a reflux condenser and an internal coil, add 2000 parts of molten 99.2% coal-derived phenol (first phenolic component) and 1000 parts of m-cresol (second phenolic component) (containing 359 parts of p-cresol, 639 parts of m-cresol, and 2 parts of o-ethylphenol). Pump 330 parts of 48% liquid alkali (sodium hydroxide being 5.28% of the mass of the first and second phenolic components) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (heated by a steam jacket) to 75°C. After the heating is completed, add 7780 parts of 36.5% formaldehyde (molar ratio of formaldehyde to phenol and m-cresol in the phenolic materials is 3.48) dropwise into the reactor from a formaldehyde metering tank within 2 hours. At this time, maintain the temperature inside the reactor at 75-80°C. After the dropwise addition is completed, maintain the reactor temperature at 90°C and react for 1 hour. Take a sample for analysis and find that the free phenol content is 3.5%, which is qualified. Add 150 parts of boric acid and stir for 0.5 hours.

[0109] Step 2: Recovery of free phenols

[0110] The material was cooled to 50°C, and a vacuum of -0.09 MPa was applied to control the dehydration below 50°C for 2 hours. At this point, the amount of oily substance in the dehydrated liquid was reduced, and dehydration was stopped. A total of 3227.9 parts of liquid were distilled off. After standing and separating, 377.9 parts of free phenol and 2849.3 parts of the upper aqueous layer were returned to the polymerization reactor. The free phenol obtained from the separation was extracted with 370 parts of methyl isobutyl ketone, and after standing, 31.2 parts of water were separated. After washing once with 40 parts of water, the layers were separated, and the aqueous layers were combined and returned to the polymerization reactor. At the same time, 713.5 parts of a methyl isobutyl ketone solution of p-cresol / phenol (including 112 parts of phenol and 233.5 parts of p-cresol) were obtained.

[0111] Step 3: Synthesis of phenolic resin for rock wool

[0112] After separating the distilled material into layers, the resulting water and wash water are mixed with the material in the polymerization reactor. Stirring is started for 0.5 hours, maintaining the material temperature at 50℃. 1200 parts of urea are then added and stirred for another 1.5 hours. After thorough mixing, 1000 parts of water are added. The mixture is discharged after the temperature drops below 40℃. The resulting wine-red transparent liquid comprises 13042.9 parts, with a solid content of 42.15%, viscosity of 8.9 mPa·s, pH of 8.1, free phenol of 0.26%, free aldehyde of 0.62%, nitrogen content of 4.29%, refractive index of 1.459, and curing time of 11 minutes at 130℃.

[0113] Step 4: Recovery of p-cresol and phenol

[0114] 713.5 parts of a methyl isobutyl ketone solution of p-cresol / phenol (112 parts of phenol and 233.5 parts of p-cresol) were added to a distillation vessel with 30 trays. The solution was heated to atmospheric pressure and then distilled under reduced pressure (-0.05 MPa) to remove 363.5 parts of solvent. The remaining solution was reused and then subjected to the following treatment:

[0115] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 160 trays, and the sample was distilled under reduced pressure (-0.085 MPa, reflux ratio 10:1) to obtain 100.6 parts of 99.7% phenol and 207.2 parts of 99.5% p-cresol.

[0116] Example 6: Using m-p-cresol and 2,4 / 2,5-xylenol as raw materials, a phenolic resin for rock wool was produced, with p-cresol and 2,4-xylenol as byproducts.

[0117] Step 1: Synthesis of Phenolic Resin Stock Solution

[0118] In a stainless steel polymerization reactor equipped with a reflux condenser and internal coil, add 2000 parts of the second phenolic component, m-cresol (containing 718 parts of p-cresol, 1232 parts of m-cresol, 4 parts of o-ethylphenol, 30.8 parts of 2,4-xylenol, and 15.2 parts of 2,5-xylenol), 403 parts of 31% liquid alkali (5% of the mass of m-cresol and 2,4 / 2,5-xylenol), and 3500 parts of 36.5% formaldehyde (the total amount of formaldehyde is 4.5 times the total molar mass of m-cresol, 2,5-xylenol, and 2,3-xylenol). After feeding, adjust the reflux and venting devices, open the steam valve to raise the temperature, start stirring, and heat to 40°C. At approximately 50-60°C, the jacket cooling water was turned off to remove the heat of reaction. The temperature was slowly increased to 75-80°C and maintained for 2 hours. The reactor temperature was 75-80°C. 1433 parts of the remaining 37% formaldehyde and 500 parts of 2,4 / 2,5-xylenol extracted from the vaporized phenol of the second phenol component were added dropwise (containing 6.5 parts of p-cresol, 11 parts of m-cresol, 18 parts of 2,3-xylenol, 274.5 parts of 2,4-xylenol, and 190 parts of 2,5-xylenol). The dropwise addition took 3 hours. After the addition was complete, the temperature was raised to 105°C and maintained for 2.5 hours. Samples were taken for analysis. The analysis showed that the free phenol content was 5.92%, which was acceptable. 125 parts of boric acid were added and stirred for 0.5 hours.

[0119] Step 2: Recovery of free phenols

[0120] The material was cooled to 50℃, and a vacuum of -0.09MPa was turned on to start the reflux process to remove free phenol. The distilled liquid was returned to the polymerization reactor in the water separator. The free phenol at the bottom of the water separator was collected in the free phenol receiving tank. After 3 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and the free phenol content was analyzed to be 0.31%, and the dehydration process was terminated. The dehydration process should be completed at the lowest possible temperature (≤60℃) to obtain 485.6 parts of aqueous free phenol (including 231.8 parts of p-cresol, 1.4 parts of o-ethylphenol, and 203.5 parts of 2,4-xylenol).

[0121] Step 3: Synthesis of phenolic resin for rock wool

[0122] After the free phenol in the polymerization reactor is qualified, 1500 parts of urea and 99.4 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 40℃. The mixture is stirred and reacted for 1.5 hours. Then, 2500 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 43.43%, pH 8.2, viscosity 9.0 mPa·s / 25℃, free phenol 0.24%, and free aldehyde 0.62%.

[0123] The material was fed to obtain 11516.9 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 6.08%, a refractive index of 1.448, a curing time of 10 minutes, and a curing temperature of 130℃.

[0124] Step 4: Recovery of p-cresol and 2,4-xylenol

[0125] 480 parts of toluene were added to 485.6 parts of a methyl isobutyl ketone solution containing water and free phenol. The mixture was stirred for 0.5 hours, allowed to stand, and 49.1 parts of the lower water layer were separated. The solvent layer was washed once with 50 parts of water. The remaining 99.6 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation reactor with 20 trays. The mixture was heated to atmospheric pressure and then distilled under reduced pressure (-0.06 MPa, reflux ratio 5) to remove 342.3 parts of toluene. This residue was then reused and subjected to the following treatment:

[0126] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays, and distilled at -0.085 MPa and a reflux ratio of 20:1 to obtain 194.4 parts of 99.3% p-cresol and 173.7 parts of 99.8% 2,4-xylenol.

[0127] Example 7: Using m-p-ethylphenol as a raw material to produce phenolic resin for rock wool, with p-ethylphenol and 2,4-xylenol as byproducts.

[0128] Step 1: Synthesis of Phenolic Resin Stock Solution

[0129] In a stainless steel polymerization reactor equipped with a reflux condenser and internal coil, add 1000 parts of the first phenolic component (99.9% molten petrified phenol), 600 parts of the second phenolic component (m- and p-ethylphenol, containing 235 parts of p-ethylphenol, 266.5 parts of m-ethylphenol, 58 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, 15 parts of 2,4 / 2,5-xylenol, and 1.5 parts of 2,4 / 2,5-methylethylphenol), 387 parts of 31% liquid alkali (6% of the mass of phenol and m- and p-ethylphenol), and 2500 parts of 36.5% formaldehyde (the total formaldehyde content is equal to the mass of phenol, m-ethylphenol, 2,5-xylenol, 2,3-xylenol, and 3,5-xylenol). After feeding (2.9 times the total molar mass of phenol and 2,5-methylethylphenol), adjust the reflux and venting devices, open the steam valve to raise the temperature, start the stirrer, and heat to 40-50℃. At around 50-60℃, open the jacket cooling water to remove the heat of reaction, slowly raise the temperature to 70℃, and maintain the temperature for 2 hours. With the reactor temperature at 75-80℃, add the remaining 1302 parts of 37% formaldehyde and the remaining 400 parts of m-p-ethylphenol for the second phenol component. The addition time is 3 hours. After the addition is complete, maintain the temperature at 85-90℃ for 3.5 hours and take a sample for analysis. The sample analysis shows that the free phenol content is 2.91%, which is qualified. Add 50 parts of boric acid and 50 parts of acetic acid and stir for 0.5 hours.

[0130] Step 2: Recovery of free phenols

[0131] The material was cooled to 50℃, and a vacuum of -0.088MPa was turned on to start the reflux process to remove free phenol. The distilled liquid was returned to the polymerization reactor in the water separator. The free phenol at the bottom of the water separator was collected in the free phenol receiving tank. After 3.5 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.13%, and the dehydration process was terminated. The dehydration should be completed at the lowest possible temperature (≤60℃) to obtain 185.1 parts of aqueous free phenol (including 155.3 parts of p-ethylphenol, 10.2 parts of 2,4-xylenol, and 1 part of 2,4-methylethylphenol).

[0132] Step 3: Synthesis of phenolic resin for rock wool

[0133] After the free phenol in the polymerization reactor is qualified, 300 parts of urea and 49.0 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 40℃. The mixture is stirred and reacted for 2 hours. 200 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 43.64%, pH 8.0, viscosity 9.2 mpa.s / 25℃, free phenol 0.10%, and free aldehyde 0.68%.

[0134] The material was fed to obtain 6570.9 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 2.14%, a refractive index of 1.522, and a curing time of 15 minutes at 130℃.

[0135] Step 4: Recovery of ethylphenol and 2,4-xylenol

[0136] In the second step, 185.1 parts of aqueous free phenol were added to 180 parts of toluene, stirred for 1 hour, and allowed to stand to separate the lower layer of water (18.7 parts). The solvent layer was washed once with 30 parts of water. The remaining 48.9 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation reactor with 20 trays, heated to atmospheric pressure, and then distilled under reduced pressure (-0.06 MPa, reflux ratio 3) to remove 170.9 parts of toluene. This residue was then reused and subjected to the following treatment:

[0137] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays, and distilled at -0.085 MPa and a reflux ratio of 20:1 to obtain 7.5 parts of 99.1% 2,4-xylenol and 129.7 parts of 99.7% p-ethylphenol.

[0138] Example 8: Using only m- and p-ethylphenol as raw materials to produce phenolic resin for rock wool, with p-ethylphenol as a byproduct.

[0139] Step 1: Synthesis of Phenolic Resin Stock Solution

[0140] In a stainless steel polymerization reactor equipped with a reflux condenser and an internal coil, add 1000 parts of the second phenolic component, m-ethylphenol (containing 391 parts of p-ethylphenol, 443 parts of m-ethylphenol, 97 parts of 2,3-xylenol, 40 parts of 3,5-xylenol, 27 parts of 2,4 / 2,5-xylenol, and 2 parts of 2,4 / 2,5-methylethylphenol), 387 parts of 31% liquid alkali (6% of the mass of m-ethylphenol), and 2000 parts of 36.5% formaldehyde (the total amount of formaldehyde is the total molar mass of m-ethylphenol, 2,5-xylenol, 2,3-xylenol, 3,5-xylenol, and 2,5-methylethylphenol). (3.7 times), after feeding is complete, adjust the reflux and venting devices, open the steam valve to raise the temperature, start stirring, heat, raise the temperature to 40-50℃, at about 50-60℃ open the jacket cooling water to remove the heat of reaction, slowly raise the temperature to 70-75℃, keep the reaction at this temperature for 2 hours, the kettle temperature is 75-80℃, add the remaining 37% formaldehyde 1226 parts, add the remaining 1000 parts of m-p-ethylphenol of the second phenol component, the adding time is 3 hours, after the addition is complete, keep the reaction at 100-105℃, keep the temperature for 1.5 hours and take a sample for analysis, the sample analysis shows that the free phenol is 9.93%, which is qualified, add 60 parts of acetic acid and stir for 0.5 hours.

[0141] Step 2: Recovery of free phenols

[0142] The material was cooled to 50℃, and a vacuum of -0.09MPa was applied to begin reflux to remove free phenol. The distilled liquid was returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator was collected in a free phenol receiving tank. After 4 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.33%, and the dehydration process was terminated. Dehydration should be completed at the lowest possible temperature (≤60℃). 589.8 parts of aqueous free phenol were obtained (including 461.8 parts of p-ethylphenol, 31.7 parts of 2,3-xylenol, 31.3 parts of 2,4-xylenol, 1.9 parts of 2,5-xylenol, 2.1 parts of 2,4-methylethylphenol, and 0.2 parts of 2,5-methylethylphenol).

[0143] Step 3: Synthesis of phenolic resin for rock wool

[0144] After the free phenol in the polymerization reactor is qualified, 800 parts of urea and 99.7 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 50℃. The mixture is stirred and reacted for 2 hours. Then, 900 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 42.09%, pH 8.3, viscosity 7.9 mpa.s / 25℃, free phenol 0.26%, and free aldehyde 0.73%.

[0145] The material can be discharged after the temperature drops below 40℃, resulting in 6570.9 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 5.68%, a refractive index of 1.451, and a curing time of 11 minutes at 130℃.

[0146] Step 4: Recovery of ethylphenol and 2,4-xylenol

[0147] In the second step, 300 parts of methyl isobutyl ketone were added to 589.8 parts of aqueous free phenol, stirred for 1 hour, and allowed to stand to separate the lower layer of water (49.3 parts). The solvent layer was washed once with 50 parts of water. The remaining 99.8 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation reactor with 20 trays, and the mixture was heated to atmospheric pressure and then reduced pressure (-0.06 MPa, reflux ratio 3) to remove 294.8 parts of methyl isobutyl ketone. This residue was then reused and subjected to the following treatment:

[0148] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays. Distillation was carried out at -0.085 MPa and a reflux ratio of 30:1 to obtain 22.8 parts of 93.4% 2,4-xylenol (21.3 parts of 2,4-xylenol and 1.2 parts of 2,5-xylenol), 89.4 parts of mixed xylenol (7.1 parts of 2,4-xylenol, 0.5 parts of 2,5-xylenol, 28.6 parts of 2,3-xylenol and 53.2 parts of p-ethylphenol), and 400.3 parts of 99.2% p-ethylphenol.

[0149] Example 9: Using crude 2,4,6-trimethylphenol as raw material to produce phenolic resin for rock wool, with 2,4-xylenol and 2,4,6-trimethylphenol as byproducts.

[0150] Step 1: Synthesis of Phenolic Resin Stock Solution

[0151] In a stainless steel polymerization reactor equipped with a reflux condenser and internal coil, add 1000 parts of the second phenolic component, m-ethylphenol (containing 391 parts of p-ethylphenol, 443 parts of m-ethylphenol, 97 parts of 2,3-xylenol, 40 parts of 3,5-xylenol, 27 parts of 2,4 / 2,5-xylenol, and 2 parts of 2,4 / 2,5-methylethylphenol), 160 parts of 25% ammonia (8% of the mass of m-ethylphenol and 2,4,6-trimethylphenol), and 1845 parts of 36.5% formaldehyde (the total amount of formaldehyde is 4.5 times the total molar mass of m-ethylphenol, 2,5-xylenol, 2,3-xylenol, 3,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol). After feeding, adjust the reflux and venting devices, open the steam valve to raise the temperature, start the stirring, and add... Heat the mixture to 40-50℃, then remove the heat of reaction by opening the jacket and cooling water at around 50-60℃. Slowly raise the temperature to 75-80℃ and maintain the reaction temperature for 4 hours. Keep the reactor temperature at 75-80℃. Add 1000 parts of the remaining 36.5% formaldehyde and 1000 parts of crude 2,4,6-trimethylphenol (containing 86 parts of p-ethylphenol, 102 parts of m-ethylphenol, 183 parts of 3,5-dimethylphenol, 45 parts of 3,4-dimethylphenol, 511 parts of 2,4,6-trimethylphenol, 52 parts of 2,4-methylethylphenol, and 21 parts of 2,5-methylethylphenol) dropwise over 3 hours. After the addition is complete, maintain the reaction temperature at 90-95℃ for 3 hours and take a sample for analysis. The sample analysis showed that the free phenol content was 14.59%, which is acceptable. Add 40 parts of boric acid and 60 parts of acetic acid and stir for 0.5 hours.

[0152] Step 2: Recovery of free phenols

[0153] The material was cooled to 50℃, and a vacuum of -0.095MPa was applied to begin reflux to remove free phenol. The distilled liquid was returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator was collected in a free phenol receiving tank. After 4 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.63%, and the dehydration process was terminated. Dehydration should be completed at the lowest possible temperature (≤55℃). 767.1 parts of aqueous free phenol were obtained (including 155.3 parts of p-ethylphenol, 12.3 parts of 2,4-xylenol, 37.2 parts of 2,4-methylethylphenol, and 485.6 parts of 2,4,6-trimethylphenol).

[0154] Step 3: Synthesis of phenolic resin for rock wool

[0155] After the free phenol in the polymerization reactor is qualified, 1000 parts of urea and 197 parts of water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 50℃. The mixture is stirred and reacted for 2 hours. Then, 1800 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 44.03%, pH 7.8, viscosity 9.8 mpa.s / 25℃, free phenol 0.49%, and free aldehyde 0.87%.

[0156] The material can be discharged after the temperature drops below 40℃, resulting in 7298.2 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 6.39%, a refractive index of 1.441, and a curing time of 10 minutes at 130℃.

[0157] Step 4: Recovery of crude 2,4,6-trimethylphenol and 2,4-xylenol

[0158] In the second step, 767.1 parts of aqueous free phenol were added to 1000 parts of methyl isobutyl ketone, stirred for 1 hour, and allowed to stand to separate the lower layer of water (76.9 parts). The solvent layer was washed once with 120 parts of water. The 197.3 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation reactor with 20 trays, heated to atmospheric pressure, and then distilled under reduced pressure (-0.06 MPa, reflux ratio 3) to remove 979.8 parts of methyl isobutyl ketone. This residue was reused and then treated as follows:

[0159] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays. Distillation was carried out at -0.085 MPa and a reflux ratio of 30:1 to obtain 7.7 parts of 99.1% 2,4-xylenol, 646.3 parts of p-ethylphenol / 2,4,6-trimethylphenol (147.5 parts of p-ethylphenol, 475.7 parts of 2,4,6-trimethylphenol, and 23.1 parts of 2,4-methylethylphenol), and 10.4 parts of 99.2% 2,4-methylethylphenol.

[0160] Example 10: Using 2,4 / 2,5-methylethylphenol and 3,4-xylenol / 2,3,6-trimethylphenol as raw materials, phenolic resin for rock wool was produced, with 2,4-methylethylphenol and 2,3,6-trimethylphenol as byproducts.

[0161] Step 1: Synthesis of Phenolic Resin Stock Solution

[0162] In a stainless steel polymerization reactor equipped with a reflux condenser and an internal coil, 1000 parts of the first phenolic component (92.8% coal-derived phenol) and 400 parts of the second phenolic component (2,4 / 2,5-methylethylphenol) were added (containing 14.8 parts of p-ethylphenol, 16.8 parts of m-ethylphenol, 38 parts of 3,5-xylenol, 59.2 parts of 3,4-xylenol, 25.2 parts of 2,3,6-trimethylphenol, and 171.2 parts of 2,4-methylethylphenol). 74.8 parts of 2,5-methylethylphenol), 168 parts of sodium monohydrogen phosphate (7% of the total mass of all phenolic components, dissolved in 300 parts of water), and 3345 parts of 36.5% formaldehyde (the total amount of formaldehyde is 4.0 times the total molar mass of m-ethylphenol, 2,5-xylenol, 2,3-xylenol, 3,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol). After feeding, adjust the reflux and venting devices, and open the steam valve to raise the temperature. Start stirring, heat to 40-50℃, and at around 50-60℃, open the jacket to remove the heat of reaction by cooling water. Slowly raise the temperature to 75-80℃ and maintain the temperature for 4 hours. When the reactor temperature is 80-85℃, add 1500 parts of the remaining 36.5% formaldehyde and 1000 parts of the second phenolic component 3,4-xylenol / 2,3,6-trimethylphenol (containing 24 parts of p-ethylphenol, 26 parts of m-ethylphenol, and 72 parts of 3,5-xylenol). 274 parts of 3,4-xylenol, 481 parts of 2,3,6-trimethylphenol, 55 parts of 2,4-methylethylphenol, 18 parts of 2,5-methylethylphenol, 27 parts of m-isopropylphenol, and 23 parts of p-isopropylphenol were added dropwise over 3 hours. After the addition was complete, the container was sealed, the temperature was raised to 110-115℃ and kept at that temperature for 2.5 hours. Samples were taken for analysis. The analysis showed that the free phenol content was 7.82%, which was acceptable. 100 parts of boric acid and 20 parts of acetic acid were then added and stirred for 0.5 hours.

[0163] Step 2: Recovery of free phenols

[0164] The material was cooled to 50℃, and a vacuum of -0.088MPa was applied to begin reflux to remove free phenol. The distilled liquid was returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator was collected in a free phenol receiving tank. After 4 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.42%, and the dehydration process was terminated. Dehydration should be completed at the lowest possible temperature (≤60℃). 629.2 parts of aqueous free phenol were obtained (including 25.2 parts of o-cresol, 13.8 parts of p-ethylphenol, 350.2 parts of 2,3,6-trimethylphenol, 165.1 parts of 2,4-methylethylphenol, and 8.5 parts of p-isopropylphenol).

[0165] Step 3: Synthesis of phenolic resin for rock wool

[0166] After the free phenol in the polymerization reactor is qualified, 1000 parts of urea and 147.5 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 30℃. The mixture is stirred and reacted for 3 hours. Then, 1000 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 41.78%, pH 7.7, viscosity 7.6 mPa·s / 25℃, free phenol 0.32%, and free aldehyde 0.83%.

[0167] The material was fed to obtain 9304.5 parts of light yellow to wine red transparent phenolic resin for rock wool, with a nitrogen content of 5.02%, a refractive index of 1.453, a curing time of 12 minutes, and a curing temperature of 130℃.

[0168] Step 4: Recovery of o-cresol, 2,4-methylethylphenol, and 2,3,6-trimethylphenol

[0169] In the second step, 629.2 parts of aqueous free phenol were added to 600 parts of ethyl acetate, stirred for 1 hour, and allowed to stand to separate the lower layer of water (66.8 parts). The solvent layer was washed once with 80 parts of water. The 147.3 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation vessel with 30 trays, heated to atmospheric pressure, and then distilled under reduced pressure (-0.06 MPa, reflux ratio 5) to remove 576.3 parts of ethyl acetate, which was then reused and subjected to the following treatment:

[0170] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 250 trays, and distilled at -0.085 MPa and a reflux ratio of 30:1 to obtain 19.8 parts of 99.7% o-cresol, 8.5 parts of 99.3% p-ethylphenol, 46.8 parts of 99.1% 2,4 / 2,5-methylethylphenol, and 430.8 parts of 77.18% crude 2,3,6-trimethylphenol (332.5 parts of 2,3,6-trimethylphenol, 92.8 parts of 2,4-methylethylphenol, and 5.5 parts of p-isopropylphenol).

[0171] Example 11: Production of phenolic resin for rock wool using m-p-isopropylphenol as raw material, with p-isopropylphenol / p-propylphenol and 2,4,5-trimethylphenol as byproducts.

[0172] Step 1: Synthesis of Phenolic Resin Stock Solution

[0173] In a stainless steel polymerization reactor equipped with a reflux condenser and an internal coil, add 1600 parts of the second phenolic component, m-p-isopropylphenol (containing 71 parts of 3,4-xylenol, 4 parts of 2,3,6-trimethylphenol, 504 parts of p-isopropylphenol, 635 parts of m-isopropylphenol, 110 parts of p-propylphenol, 149 parts of m-propylphenol, 13 parts of 2,3-methylethylphenol, 52 parts of 3-ethyl-5-methylphenol, 29 parts of 2,3,5-trimethylphenol, 3 parts of 2,4 / 2,5-methylethylphenol, and 30 parts of 2,4,5-trimethylphenol), 465 parts of 31% liquid alkali (the liquid alkali is an aqueous solution of sodium hydroxide, accounting for 7% of the mass of m-p-isopropylphenol), and 2040 parts of 36.5% formaldehyde (the total amount of formaldehyde used is 3,4-xylenol, 2,5-methylethylphenol, and m-p-isopropylphenol). After feeding is complete (3.5 times the total molar mass of isopropylphenol, m-propylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, and 2,3,5-trimethylphenol), adjust the reflux and venting devices, open the steam valve to raise the temperature, start stirring, and heat to 40-50℃. At around 50-60℃, open the jacket cooling water to remove the heat of reaction, slowly raise the temperature to 75-80℃, and maintain the reaction temperature for 3 hours. At a reactor temperature of 80-85℃, add 1000 parts of the remaining 36.5% formaldehyde and 800 parts of the second phenol component, m-p-isopropylphenol, over a period of 2 hours. After the addition is complete, maintain the reaction temperature at 100-105℃ for 5 hours, and take a sample for analysis. The sample analysis shows that the free phenol content is 7.24%, which is acceptable. Add 20 parts of phosphoric acid and 80 parts of acetic acid and stir for 1 hour.

[0174] Step 2: Recovery of free phenols

[0175] The material was cooled to 50℃, and a vacuum of -0.095MPa was applied to begin reflux to remove free phenol. The distilled liquid was returned to the polymerization reactor via a water separator. The free phenol at the bottom of the water separator was collected in a free phenol receiving tank. After 4 hours of dehydration, when the amount of oily material in the dehydrated liquid was low, a sample was taken from the reactor and analyzed. The free phenol content was 0.55%, and the dehydration process was terminated. Dehydration should be completed at the lowest possible temperature (≤50℃). 428.8 parts of aqueous free phenol were obtained (including 4.2 parts of 2,3,6-trimethylphenol, 2.2 parts of 2,4-methylethylphenol, 279.8 parts of p-isopropylphenol, 59.3 parts of p-propylphenol, and 40.5 parts of 2,4,5-trimethylphenol).

[0176] Step 3: Synthesis of phenolic resin for rock wool

[0177] After the free phenol in the polymerization reactor is qualified, 800 parts of urea and 143.3 parts of the water from the fourth step of the previous batch are added when the temperature inside the reactor is controlled at 50℃. The mixture is stirred and reacted for 1.5 hours. 2000 parts of water are added to adjust the viscosity and solid content. The sample analysis shows: solid content 43.72%, pH 7.9, viscosity 9.5 mpa.s / 25℃, free phenol 0.43%, and free aldehyde 0.76%.

[0178] The material can be discharged after the temperature drops below 40℃, resulting in 8476.9 parts of light yellow transparent phenolic resin for rock wool, with a nitrogen content of 4.40%, a refractive index of 1.473, and a curing time of 13 minutes at 130℃.

[0179] Step 4: Recovery of isopropylphenol / p-propylphenol and 2,4,5-trimethylphenol

[0180] In the second step, 500 parts of toluene were added to 428.8 parts of the aqueous free phenol, stirred for 1 hour, and allowed to stand to separate the lower layer of water (43.1 parts). The solvent layer was washed once with 100 parts of water. The 143.7 parts of water after the two separations were returned to the polymerization reactor and combined with the next batch of phenolic resin for rock wool. The washed solvent layer was added to a distillation reactor with 30 trays, heated to atmospheric pressure, and then distilled under reduced pressure (-0.06 MPa, reflux ratio 5) to remove 489.3 parts of toluene. This was then reused and subjected to the following treatment:

[0181] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 200 trays, and distilled at -0.085 MPa and a reflux ratio of 30:1 to obtain 353.8 parts of 93.02% p-isopropylphenol / p-propylphenol (2.6 parts of 2,3,6-trimethylphenol, 271.5 parts of p-isopropylphenol, 57.6 parts of p-propylphenol, and 22.1 parts of 2,4,5-trimethylphenol) and 16.3 parts of 98.2% 2,4,5-trimethylphenol.

[0182] Example 12: Production of phenolic resin for rock wool using mixed phenols as raw materials

[0183] In a stainless steel reactor equipped with a reflux condenser and internal coil, 2000 parts of mixed phenols (containing 1432 parts phenol and 568 parts o-cresol) were extracted from the tar of the first phenol component. 250 parts of 48% liquid alkali (sodium hydroxide at 6% of the mass of the mixed phenols) were pumped into the reactor. After the mixed phenols and liquid alkali were added, the reactor (heated by a steam jacket) was heated to 75°C. After heating, 6000 parts of 36.5% formaldehyde were added dropwise to the reactor from the formaldehyde metering tank within 3 hours. The phenol content in the mixed phenols is 4.79 times the molar mass of phenol. At this point, the temperature inside the reactor is maintained at 75–80°C. After the addition is complete, the reactor temperature is maintained at 90–95°C for 3 hours. After the o-cresol content is found to be 0.82% and meets the standard, the temperature is rapidly reduced (circulating cooling water is used for cooling through the reactor coils) to 55°C. When the reactor temperature drops to 50°C, 1500 parts of urea are added and stirred for 1 hour. After thorough stirring, 1840 parts of water are added. The mixture is discharged after the temperature drops below 40°C. 11532 parts of a brownish-red transparent liquid are obtained, with a solid content of 42.32%, viscosity of 7.8 mPa·s, pH 9, free phenol of 0.52%, free aldehyde of 0.68%, nitrogen content of 6.07%, refractive index of 1.455, and curing time of 10.5 minutes at 130°C.

[0184] Example 13: Production of phenolic resin for rock wool using gasified phenol and coked m-p-cresol as raw materials

[0185] In a stainless steel reactor equipped with a reflux condenser and internal coil, add 2000 parts of molten 99.2% vaporized phenol (first phenolic component) and 500 parts of coking m-p-cresol (second phenolic component) (containing 179.5 parts of p-cresol, 319.5 parts of m-cresol, and 1 part of o-ethylphenol). Pump 330 parts of 48% liquid alkali (sodium hydroxide being 5.28% of the mass of phenol and m-p-cresol) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (steam-jacketed heating) to 75°C. After heating, add 880g of 36.5% formaldehyde dropwise into the reactor from the formaldehyde metering tank within 3 hours. Add 0 parts (3.94 times the molar mass of phenol and m-cresol in the phenolic material) and 500 parts of coking m-p-cresol dropwise, maintaining the reactor temperature at 75-80℃. After the dropwise addition is complete, maintain the reactor temperature at 85-90℃ for 3 hours. After the p-cresol (free phenol) content is found to be 0.61% and meets the standard, rapidly cool down (using circulating cooling water through the reactor coils) to 50℃, and add 150 parts of boric acid and stir for 0.5 hours. Continue to add 2500 parts of urea and stir for 1.5 hours. After stirring evenly, add 2500 parts of water. Discharge the material after the temperature drops below 40℃. A reddish-brown transparent liquid of 17192.6 parts is obtained, with a solid content of 43.12%, viscosity of 8.2 mPa·s, pH of 8.3, free phenol of 0.41%, free aldehyde of 0.63%, nitrogen content of 6.77%, refractive index of 1.438, and curing time of 10 minutes at 130℃.

[0186] Example 14: Production of phenolic resin for rock wool using petrochemical phenol and tar-based m-p-ethylphenol as raw materials

[0187] In a stainless steel reactor equipped with a reflux condenser and internal coil, add 2000 parts of molten petrified 99.9% phenol (first phenolic component) and 600 parts of m- and p-ethylphenol (second phenolic component) (containing 247.5 parts of p-ethylphenol, 266.5 parts of m-ethylphenol, 58 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, 2.5 parts of 2,4 / 2,5-xylenol, and 1.5 parts of 2,4 / 2,5-methylethylphenol). Pump 350 parts of 48% liquid alkali (sodium hydroxide being 5.25% of the mass of phenol and m- and p-ethylphenol) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (steam-jacketed heating) to 80°C. After heating, add 9 parts of 36.5% formaldehyde dropwise into the reactor from the formaldehyde metering tank within 2.5 hours. Add 0.077 parts (4.08 times the molar mass of phenol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, and 2,5-methylethylphenol) of the second phenolic component, and dropwise add 600 parts of m-p-ethylphenol. At this time, maintain the temperature inside the reactor at 80-85℃. After the dropwise addition is complete, seal the container and first maintain the reactor temperature at 120-130℃ for 1.5 hours. After the p-ethylphenol content is found to be 0.43% and meets the requirements, quickly cool down (circulating cooling water is used to cool down through the coil inside the reactor) to 60℃, and add 150 parts of boric acid and stir for 0.5 hours. Continue to cool down to 50℃ and add 2500 parts of urea, stirring for 2 hours. After stirring evenly, add 2500 parts of water. Discharge the material after the temperature drops below 40℃. 17688.1 parts of a reddish-brown transparent liquid were obtained, with a solid content of 43.55%, a viscosity of 7.5 mPa·s, a pH of 8.5, 0.34% free phenol, 0.71% free aldehyde, a nitrogen content of 6.6%, a refractive index of 1.442, and a curing time of 10 minutes at 130℃.

[0188] Example 15: Production of phenolic resin for rock wool using coal-derived phenol and tar-derived m- and p-isopropylphenol as raw materials.

[0189] In a stainless steel reactor equipped with a reflux condenser and an internal coil, add 2000 parts of the first phenolic component (99.2% molten coal-derived phenol) and 1000 parts of the second phenolic component (tar-derived m-isopropylphenol), which contains 44.4 parts of 3,4-xylenol, 2.5 parts of 2,3,6-trimethylphenol, 315 parts of p-isopropylphenol, 396.9 parts of m-isopropylphenol, 85 parts of p-propylphenol, 93.1 parts of m-propylphenol, and 2,3-... 8.1 parts of methyl ethyl phenol, 32.5 parts of 3-ethyl-5-methyl phenol, 18.1 parts of 2,3,5-trimethyl phenol, 1.9 parts of 2,4 / 2,5-methyl ethyl phenol, and 2.5 parts of 2,4,5-trimethyl phenol were added to the reactor. 412 parts of 48% liquid alkali (sodium hydroxide being 5.5% of the mass of phenol and m- and p-isopropyl phenol) were pumped into the reactor. After the phenolic materials and liquid alkali were added, the reactor (heated by a steam jacket) was raised... After heating to 75℃, add 10340 parts of 36.5% formaldehyde (4.44 times the molar mass of phenol, 3,4-xylenol, m-isopropylphenol, m-propylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, 2,3,5-trimethylphenol, and 2,5-methylethylphenol) dropwise to the reactor from the formaldehyde metering tank within 3 hours. Add 600 parts of the second phenolic component, m-p-isopropylphenol. At this time, maintain the temperature inside the reactor at 80-85℃. After the addition is complete, maintain the temperature inside the reactor at 90-95℃ for 5 hours. After the p-isopropylphenol / p-propylphenol ratio is found to be 0.76% and meets the requirements, quickly cool down (circulating cooling water is used to cool down through the coil inside the reactor) to 50℃ and add 2900 parts of urea. Stir for 2 hours and stir evenly. After stirring, add 3600 parts of water. Discharge the material after the temperature drops below 40℃. 20747.6 parts of a reddish-brown transparent liquid were obtained, with a solid content of 43.89%, viscosity of 8.8 mPa·s, pH of 8.4, free phenol of 0.41%, free aldehyde of 0.55%, nitrogen content of 6.52%, refractive index of 1.452, and curing time of 10.3 m at 130℃.

[0190] Example 16: Production of phenolic resin for rock wool using tar-based low-grade 95% phenol, mixed phenols, m-p-cresol, m-p-ethylphenol, and m-p-isopropylphenol as raw materials.

[0191] In a stainless steel reactor equipped with a reflux condenser and an internal coil, add 2000 parts of molten coal-coated 95.2% phenol (first phenol component), 1500 parts of mixed phenols (first phenol component, including 1074 parts of phenol and 426 parts of o-cresol), 600 parts of m-p-cresol (second phenol component, including 264 parts of p-cresol, 278 parts of m-cresol, and 58 parts of o-ethylphenol), and 600 parts of m-p-ethylphenol (second phenol component, including 248 parts of p-ethylphenol, 266 parts of m-ethylphenol, 58 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, and 2,3-xylenol). 2 parts of 4 / 2,5-xylenol and 2 parts of 2,4 / 2,5-methylethylphenol; 600 parts of the second phenolic component, m-p-isopropylphenol (containing 26 parts of 3,4-xylenol, 2 parts of 2,3,6-trimethylphenol, 240 parts of p-isopropylphenol, 294 parts of m-isopropylphenol, 5 parts of 2,3-methylethylphenol, 20 parts of 3-ethyl-5-methylphenol, 11 parts of 2,3,5-trimethylphenol, 1 part of 2,4 / 2,5-methylethylphenol, and 1 part of 2,4,5-trimethylphenol); and 650 parts of 48% liquid alkali (sodium hydroxide is the first phenolic component and the second phenolic component). 5.89% of the phenolic components (by mass) are pumped into the reactor; after the phenolic materials and liquid alkali have been added, the reactor (heated by steam jacket) is heated to 80°C. After heating, 14,780 parts of 36.5% formaldehyde (containing phenol, m-cresol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, 2,5-methylethylphenol, 3,4-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-cresol, 2,3,5-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-cresol, 2,3,5-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-cresol, 2,3,5-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-cresol, 2,3,5-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 2,3,5-xylenol, m-methyl-5-cresol, m-methylethylphenol ... Add 4.41 times the molar mass of tricresyl (at this point, maintain the temperature inside the reactor at 80-85℃); after the addition is complete, seal the container and maintain the reactor temperature at 100-105℃ for 4.5 hours. After the free phenol content is found to be 0.48% and meets the standard, rapidly cool down (circulating cooling water is used to cool the reactor through the internal coil) to 50℃, and add 150 parts of boric acid and stir for 0.5 hours; cool down to 40℃ and add 4000 parts of urea, stirring for 2 hours. After stirring evenly, add 5300 parts of water, and discharge the material after the temperature drops below 40℃. A yellow to wine-red transparent liquid of 30029.1 parts is obtained, with a solid content of 43.26%, viscosity of 8.6 mPa·s, pH of 8.4, free phenol of 0.36%, free aldehyde of 0.68%, nitrogen content of 6.22%, refractive index of 1.448, and curing time of 10.8 m at 130℃.

[0192] Example 17: Phenolic resin for rock wool was produced using tar-based low-grade 95% phenol, mixed phenols, m-p-cresol, m-p-ethylphenol, and m-p-isopropylphenol as raw materials.

[0193] In a stainless steel medium-pressure reactor equipped with a reflux condenser and an internal coil, 2000 parts of molten coal-derived 95.2% phenol (first phenol component) and 1500 parts of mixed phenols (first phenol component, including 1074 parts of phenol and 426 parts of o-cresol) were added. 600 parts of m-p-cresol (including 264 parts of p-cresol, 278 parts of m-cresol, and 58 parts of o-ethylphenol) and 600 parts of m-p-ethylphenol (including 248 parts of p-ethylphenol, 266 parts of m-ethylphenol, 58 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, and 2 parts of 2,4 / 2,5-xylenol) were extracted from the tar. 2 parts of 2,4 / 2,5-methylethylphenol and 600 parts of tar-derived m-p-isopropylphenol (containing 26 parts of 3,4-xylenol, 2 parts of 2,3,6-trimethylphenol, 240 parts of p-isopropylphenol, 294 parts of m-isopropylphenol, 5 parts of 2,3-methylethylphenol, 20 parts of 3-ethyl-5-methylphenol, 11 parts of 2,3,5-trimethylphenol, 1 part of 2,4 / 2,5-methylethylphenol, and 1 part of 2,4,5-trimethylphenol) are mixed and prepared for dropwise addition to obtain 1800 parts of the second phenolic component mixed with m-p-alkylphenol; 650 parts of 48% liquid alkali (sodium hydroxide is used for the first and second phenolic components) are added. 5.89% of the phenolic components (by mass) were pumped into a stainless steel reactor. After the addition of 95.2% phenol, mixed phenols, and liquid alkali, the reactor (heated by a steam jacket) was raised to 85°C. After the temperature was raised, 15,620 parts of 36.5% formaldehyde (containing phenol, m-cresol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, 2,5-methylethylphenol, 3,4-xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-cresol, and 2,3,5-trimethylphenol) were added dropwise to the reactor from the formaldehyde metering tank within 3 hours. (4.66 times the molar mass), while simultaneously adding 1800 parts of the second phenol component mixed with m- and p-alkylphenols dropwise over 2 hours, maintaining the reactor temperature at 80-85℃. After the addition is complete, maintain the reactor temperature at 90-95℃ for 3 hours, then seal the reactor and react at 130-135℃ for 1 hour. After the free phenol content is found to be 0.08% and meets the standard, rapidly cool down (using circulating cooling water through the reactor coils) to 50℃ and add 4000 parts of urea, stirring for 2 hours. After thorough mixing, add 5150 parts of water, and discharge the material after the temperature drops below 40℃. A reddish-brown transparent liquid of 30566.4 parts is obtained, with a solid content of 42.88%, viscosity of 8.3 mPa·s, pH of 8.4, free phenol of 0.08%, free aldehyde of 0.59%, nitrogen content of 6.11%, refractive index of 1.449, and curing time of 10.9 m at 130℃.

[0194] Example 18: Production of phenolic resin for rock wool using low-grade 95% phenol from tar as raw material

[0195] Add 2000 parts of 95.2% phenol (1904 parts phenol, 96 parts o-cresol) to a stainless steel reactor equipped with a reflux condenser and internal coil. Pump 221 parts of 48% liquid alkali (sodium hydroxide at 5.3% of the phenol mass) into the stainless steel reactor. After the 95.2% phenol and liquid alkali have been added, heat the reactor (steam-jacketed) to 70°C. After heating, transfer formaldehyde from the formaldehyde metering tank to the reactor within 3 hours. Add 5827 parts of 36.5% formaldehyde (3.5 times the molar mass of phenol in phenolic compounds) dropwise. After the addition is complete, maintain the reactor temperature at 90-95℃ for 5 hours. After gel permeation chromatography analysis shows that o-cresol is 0.28% and meets the requirements, rapidly cool down (circulating cooling water is used for cooling through the coil inside the reactor) to 50℃ and add 1500 parts of urea, stirring for 2 hours. After stirring evenly, add 1900 parts of water. Discharge the material after the temperature drops below 40℃. A wine-red transparent liquid of 11390.8 parts is obtained, with a solid content of 42.23%, viscosity of 7.6 mPa·s, pH of 8.4, free phenol of 0.22%, free aldehyde of 0.71%, nitrogen content of 6.15%, refractive index of 1.445, and curing time of 10.6 minutes at 130℃.

[0196] Example 19: Production of phenolic resin for rock wool using tar-based m-p-ethylphenol as a raw material

[0197] Add 1200 parts of the second phenolic component, m-ethylphenol (containing 495 parts of p-ethylphenol, 533 parts of m-ethylphenol, 116 parts of 2,3-xylenol, 48 parts of 3,5-xylenol, 5 parts of 2,4 / 2,5-xylenol, and 3 parts of 2,4 / 2,5-methylethylphenol), to a stainless steel reactor equipped with a reflux condenser and internal coil. Pump 138 parts of 48% liquid alkali (sodium hydroxide being 5.5% of the mass of m-ethylphenol) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (steam-jacketed heating) to 70°C. After heating, add 217 parts of 36.5% formaldehyde dropwise into the reactor from the formaldehyde metering tank within 3 hours. Add 0 parts (4.6 times the molar mass of phenolic materials: intermediate ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, and 2,5-methylethylphenol). At this point, maintain the temperature inside the reactor at 70-75℃. After the addition is complete, maintain the reactor temperature at 90-95℃ for 3.5 hours. After the ethylphenol content is found to be 0.83%, quickly cool down (using circulating cooling water through the reactor coils) to 60℃, and add 30 parts of boric acid and stir for 0.5 hours. Continue cooling to 45℃ and add 600 parts of urea, stirring for 2 hours. After stirring evenly, add 1500 parts of water. Discharge the material after the temperature drops below 40℃. 5609.8 parts of a wine-red transparent liquid were obtained, with a solid content of 43.11%, a viscosity of 8.1 mPa·s, a pH of 8.8, 0.65% free phenol, 0.77% free aldehyde, a nitrogen content of 4.99%, a refractive index of 1.475, and a curing time of 12.8 m at 130℃.

[0198] Example 20: Production of phenolic resin for rock wool using tar-cresol as a raw material

[0199] Add 1000 parts of vaporized cresol (containing 65.5 parts phenol, 203 parts o-cresol, 5 parts 2,6-xylenol, 224 parts p-cresol, 407 parts m-cresol, 11.2 parts o-ethylphenol, 54.8 parts 2,4-xylenol, and 29.5 parts 2,5-xylenol) to a stainless steel reactor equipped with a reflux condenser and internal coil. Then pump 146 parts of 48% liquid alkali (sodium hydroxide being 7% of the mass of m- and p-ethylphenol) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (steam-jacketed) to 70°C. Then, within 4 hours, 2321 parts of 36.5% formaldehyde (6 times the molar mass of phenol, m-cresol, and 2,5-xylenol in the phenolic materials) were added dropwise from the formaldehyde metering tank into the reactor. During this time, the reactor temperature was maintained at 70-75℃. After the addition was complete, the reactor temperature was maintained at 90-95℃ for 4 hours. After the free phenol content was found to be 1.13% (qualified), the temperature was rapidly lowered (circulating cooling water was used for cooling through the reactor coils) to 40℃. 600 parts of urea were then added and stirred for 2 hours. After thorough stirring, 1000 parts of water were added. The mixture was discharged after the temperature dropped below 40℃. 5041.7 parts of a reddish-brown transparent liquid were obtained, with a solid content of 42.6%, viscosity of 7.8 mPa·s, pH of 8.9, free phenol of 0.78%, free aldehyde of 0.91%, nitrogen content of 5.55%, refractive index of 1.469, and curing time of 11.7 minutes at 130℃.

[0200] Example 21: Production of phenolic resin for rock wool using tar-p-cresol as raw material

[0201] Add 800 parts of 45% m-p-cresol (containing 2.4 parts o-cresol, 7.2 parts 2,6-xylenol, 344 parts p-cresol, 366.4 parts m-cresol, 66.4 parts o-ethylphenol, 8.8 parts 2,4-xylenol, and 4.8 parts 2,5-xylenol) to a stainless steel reactor equipped with a reflux condenser and internal coil. Pump 100 parts of 25% ammonia water (sodium hydroxide being 10% of the mass of m-p-ethylphenol) into the reactor. After the phenolic materials and ammonia water have been added, heat the reactor (steam-jacketed heating) to 85°C. After heating, allow 3.5 hours... 2116 parts of 36.5% formaldehyde (6 times the molar mass of the phenolic materials intermediate cresol and 2,5-xylenol) were added dropwise from the formaldehyde metering tank to the reactor, along with 200 parts of 45% m-p-cresol tar. The reactor temperature was maintained at 85–90°C. After the addition was complete, the reactor temperature was maintained at 90–95°C for 6 hours. Once the free phenol content was found to be 1.04% (qualified), the temperature was rapidly lowered (circulating cooling water was used for cooling through the reactor's internal coils) to 40°C. 400 parts of urea were then added and stirred for 2 hours. After thorough mixing, 800 parts of water were added. The mixture was discharged after the temperature dropped below 40°C. The resulting product was a reddish-brown transparent liquid with a solid content of 42.2%, viscosity of 8.7 mPa·s, pH of 7.7, free phenol content of 0.69%, free aldehyde content of 0.88%, nitrogen content of 4.25%, refractive index of 1.483, and curing time of 13 minutes at 130°C.

[0202] Example 22: Production of phenolic resin for rock wool using tar-based m-p-isopropylphenol as a raw material

[0203] Add 1200 parts of the second phenolic component tar (containing 52 parts of 3,4-xylenol, 15 parts of 2,3,6-trimethylphenol, 469 parts of p-isopropylphenol, 571 parts of m-isopropylphenol, 10 parts of 2,3-methylethylphenol, 40 parts of 3-ethyl-5-methylphenol, 22 parts of 2,3,5-trimethylphenol, 2 parts of 2,4 / 2,5-methylethylphenol, and 19 parts of 2,4,5-trimethylphenol) and 250 parts of urea to a stainless steel medium-pressure reactor equipped with a reflux condenser and internal coil. Pump 150 parts of 48% liquid alkali (sodium hydroxide is 6% of the mass of m-p-isopropylphenol) into the reactor. After the phenolic materials and liquid alkali have been added, heat the reactor (steam jacket heating) to 70°C. After heating, [the process continues at 4...] Within one hour, 2120 parts of 36.5% formaldehyde (5 times the molar mass of 3,4-xylenol, m-isopropylphenol, 2,3 / 2,5-methylethylphenol, 3-ethyl-5-methylphenol, and 2,3,5-trimethylphenol) are added dropwise from the formaldehyde metering tank into the reactor. At this time, the temperature inside the reactor is maintained at 70-75℃. After the addition is completed, the temperature of the reactor is maintained at 85-90℃ for 5 hours, and the free phenol content is analyzed to be 1.3%. Then, the reactor is sealed and reacted at 140-145℃ for 2 hours, and the free phenol content is analyzed to be 0.13%. The temperature is rapidly reduced (circulating cooling water is used to cool the reactor through the coil inside the reactor) to 50℃. 800 parts of water and 30 parts of boric acid are added and stirred for 1 hour. The material is discharged after the temperature drops below 40℃. 4528.2 parts of a reddish-brown transparent liquid were obtained, with a solid content of 42.1%, a viscosity of 7.9 mPa·s, a pH of 8.1, 0.12% free phenol, 0.78% free aldehyde, a nitrogen content of 2.58%, a refractive index of 1.518, and a curing time of 15 minutes at 130℃.

[0204] Comparative Example 1: Production of rock wool resin using traditional pure phenol process (urea added after phenolic resin synthesis).

[0205] Add 1000 kg of petrochemical 99.9% phenol to a 6300L stainless steel reactor equipped with a reflux condenser and internal coil. Pump 105 kg of 48% liquid alkali (sodium hydroxide aqueous solution) into the reactor simultaneously through a metering tank. After the phenol and sodium hydroxide are added, heat the reactor (steam jacket heating) to 70°C. After heating, add 2933 kg of 36.5% formaldehyde dropwise to the reactor through a formaldehyde metering tank within 120 minutes, maintaining the reactor temperature at 68–70°C. After the dropwise addition is complete, maintain the reactor temperature at 70°C for 120 minutes. After gel chromatography analysis confirms the phenol content is 1.42% and meets the standard, rapidly cool down the reactor (using circulating cooling water through the internal coil). When the reactor temperature drops to 50°C, add 750 kg of urea and stir for 1 hour. After stirring evenly, add 1000 kg of water. Discharge the reactor after the temperature drops below 40°C. 5726 kg of wine-red transparent liquid was obtained, with a solid content of 41.72%, viscosity of 8 mPa·s, pH of 7.9, free phenol of 0.82%, free aldehyde of 0.93%, nitrogen content of 6.11%, refractive index of 1.458, and curing time of 11 m at 130℃.

[0206] Comparative Example 2: Production of rock wool resin using traditional pure phenol process (urea is added during the synthesis of phenolic resin).

[0207] Add 1000 kg of 99.9% petrochemical phenol and 200 kg of urea to a 6300L stainless steel reactor equipped with a reflux condenser and internal coil. Pump 105 kg of 48% liquid alkali (sodium hydroxide aqueous solution) into the reactor via a metering tank. After the phenol and sodium hydroxide are added, heat the reactor (heated by a steam jacket) to 70°C. After heating, add 2728 kg of 36.5% formaldehyde dropwise into the reactor via a formaldehyde metering tank within 2 hours, maintaining the reactor temperature between 68 and 70°C. After the dropwise addition is complete, maintain the reactor temperature at 70°C for 2 hours and then at 80°C for 2 hours. After the phenol content reaches 0.97% and is deemed acceptable, rapidly cool the reactor to 50°C (using circulating cooling water through the internal coil). Add 100 kg of water while stirring, and discharge the material once the temperature drops below 40°C. 4316.3 kg of brownish-red transparent liquid was obtained, with a solid content of 38.22%, viscosity of 7 mPa·s, pH of 8.9, free phenol of 0.95%, free aldehyde of 0.90%, nitrogen content of 2.16%, refractive index of 1.488, and curing time of 15 minutes at 130℃.

[0208] Compared with Examples 1-22, Comparative Examples 1 and 2 have similar product performance, with slightly higher levels of free phenol, but significantly higher raw material costs.

[0209] The above examples and comparative examples fully demonstrate that the present invention can use various inexpensive coal-based mixed phenols as raw materials and, through flexible process adjustments, produce qualified phenolic resin for rock wool. It can also simultaneously and efficiently co-produce a variety of high-purity, high-value-added alkylphenols, resulting in significant economic benefits and advantages in comprehensive resource utilization.

[0210] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0211] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A method for synthesizing phenolic resin for rock wool, characterized in that, Includes the following steps: Step 1: Phenolic Resin Synthesis Add the first phenolic component to the reactor, then add a portion of the second phenolic component. Add an alkaline catalyst (1-10% of the total phenolic material) and a portion of aldehydes to the reactor. After the phenols and alkaline catalyst have been added, heat the reactor to 40-80°C and react for 1-4 hours. Continue heating to 50-90°C and add the remaining aldehydes and the remaining second component dropwise to the reactor over 1-4 hours. After the addition is complete, maintain the reactor temperature at 60-150°C for 1-6 hours. After sampling and analysis, if the free phenol content is ≤15%, quickly cool the reactor to below 60°C and add a weak acid as a modifier and stabilizer. Step 2: Recovery of free phenols Open the valve of the reflux separator on the reactor, gradually open the vacuum to remove free phenol, control the dehydration at low temperature (-0.08~-0.1MPa), and keep the dehydration temperature ≤60℃. Let the distilled liquid stand in the separator, continuously separating the lower layer of free phenol, and return the upper layer of water to the polymerization reactor. The free phenol removal time is 1~4 hours. Sampling and analysis should begin 1~2 hours after the free phenol removal is completed, and the free phenol in the reaction solution should be ≤2%. The separated free phenol is purified by distillation in the fourth step. Step 3: Synthesis of phenolic resin for rock wool After the free phenol is qualified, urea and the water from the fourth step of the previous batch are added while the temperature inside the reactor is controlled at 20-80℃. The mixture is stirred and reacted for 1-4 hours. Sampling and analysis are performed: pH 7.5-9.5, free phenol ≤2%, free aldehyde ≤1% are qualified. Water is added under stirring to adjust the viscosity and solid content. Sampling and analysis are performed: solid content 38-45%, pH 7.5-9.5, viscosity ≤12mpa.s / 25℃, free phenol ≤2%, free aldehyde ≤1%. The material can be discharged after the temperature drops below 40℃ to obtain light yellow to reddish brown transparent phenolic resin for rock wool. Step 4: Recovery of ortho- and para-alkylphenols Extract the free phenol obtained from the second distillation step by adding 0.5 to 2 times its volume of a non-water-soluble solvent. Allow it to stand to separate the lower layer of water. Wash the solvent layer once with water (0.1 to 0.5 times the mass of the non-water-soluble solvent). Return the separated water to the polymerization reactor and combine it with the phenolic resin for rock wool. Add the washed solvent layer to a distillation reactor with 5 to 50 trays. Distill under normal pressure and then under reduced pressure (-0.03 to -0.07 MPa, reflux ratio 1 to 5) to remove the solvent and reuse the solution. Then, perform the following treatment: The material in the distillation vessel is transferred to a high-efficiency distillation vessel with 100 to 300 trays, and the material is distilled under reduced pressure to obtain at least one of the following: 99.5% o-cresol, 99% 2,6-xylenol, 98% p-cresol or p-cresol / o-ethylphenol, 90% 2,4-xylenol, 98% p-ethylphenol or p-ethylphenol / 2,3-xylenol, 2,4,6-trimethylphenol, 2,4-methylethylphenol, 2,3,6-trimethylphenol, p-isopropylphenol, or p-isopropyl / p-propylphenol.

2. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The first phenolic component is phenol or a mixture of phenols; the phenol contains ≥90% phenol and ≤10% o-cresol; the mixture of phenols is composed of phenol and o-cresol, wherein the o-cresol content is 10-50% and the phenol content is 50-90%, and may also contain 0-40% m-p-cresol, 0-10% 2,6-xylenol and 0-5% 2,4 / 2,5-xylenol.

3. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The first step involves selecting at least one or a mixture of two or more of the following: o-cresol fraction, cresol, 2,6-xylenol, m-p-cresol, 2,4 / 2,5-xylenol, m-p-ethylphenol, 2,4,6-trimethylphenol, 2,4 / 2,5-methylethylphenol, 3,4-xylenol / 2,3,6-trimethylphenol, m-p-propylphenol / isopropylphenol; and the second phenolic component is obtained by distillation of crude phenol extracted from coal coking, crude phenol extracted from medium-low temperature coal gasification, or crude phenol extracted from phenol-containing coal tar by coal pyrolysis.

4. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The first step is that the mass ratio of the first phenolic component to the second phenolic component is 0:100 to 100:0, preferably 50:50 to 80:

20.

5. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The first step involves the alkaline catalyst being an aqueous solution of sodium hydroxide, potassium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, sodium monohydrogen phosphate, sodium phosphate, or ammonia; the aldehyde being an aqueous solution of formaldehyde, paraformaldehyde, or acetaldehyde; and the amount of aldehyde being used being 1 to 8 times the total molar amount of the phenolic materials, preferably 2 to 5 times.

6. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The first step involves using a weak acid such as boric acid, phosphoric acid, acetic acid, or formic acid, with boric acid and phosphoric acid being preferred. The amount of boric acid or phosphoric acid used is 0-5% of the mass of the phenolic material.

7. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... The third step involves using urea at a rate of 0.01 to 1.5 times the mass of the phenolic materials, preferably 0.1 to 0.8 times.

8. The method for synthesizing phenolic resin for rock wool according to claim 1, characterized in that... Fourth step, the non-water-soluble solvent is an aromatic hydrocarbon, a chlorinated alkane, an ether, an ester, etc., preferably toluene or methyl isobutyl ether.

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