Method for synthesizing phenolic resin and by-producing ortho-position and para-position alkylphenol

Abstract

The invention relates to the technical field of organic synthesis and chemical separation, in particular to a method for synthesizing phenolic resin and by-producing ortho-alkylphenol and para-alkylphenol, which is characterized in that high-activity meta-phenol and most phenol are systematically and preferentially reacted with formaldehyde by controlling the feeding sequence and reaction depth of reactants according to the difference of reaction rates of different phenols and formaldehyde; according to the method, a phenolic resin product is subjected to dehydration to generate a phenolic resin polymer, most of low-activity ortho-alkylphenol and para-alkylphenol are retained in unreacted substances due to slow reaction, the unreacted phenols and water are evaporated in the dehydration process, primary separation from the resin product is realized, and a small amount of formaldehyde and incompletely reacted meta-phenol still exist in the evaporated water phase; according to the method, the ortho-phenol and para-phenol are subjected to a further reaction to generate a water-soluble oligomer, so that meta-phenol impurities are effectively prevented from being mixed into a subsequent oil phase, high purity of ortho-phenol and para-phenol products is ensured, and finally separation from water and the water-soluble impurities is completed through solvent extraction.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and chemical separation technology, specifically relating to a method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin synthesis. 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] Therefore, developing an integrated process that can utilize inexpensive mixed alkylphenols with complex compositions to partially replace phenol, while simultaneously producing qualified phenolic resins and efficiently separating and purifying various high-priced ortho- and para-alkylphenols, has significant economic and environmental value. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing ortho- and para-alkylphenols as byproducts of phenolic resin production. This method partially or completely replaces petrochemical phenols with inexpensive coal-based phenols, mixed phenols, and various coal-based mixed alkylphenols (such as cresol, m- and p-cresol, 2,4 / 2,5-xylenol, m- and p-ethylphenol, 2,4,6-trimethylphenol, and m- and p-isopropylphenol), producing general-purpose phenolic resins. Furthermore, by utilizing the differences in reactivity among different phenols and controlling the reaction process and subsequent separation and purification, high-purity phenols, ortho- and para-cresol, 2,6-xylenol, p-cresol, p-ethylphenol, 2,4-xylenol, and p-isopropylphenol, among other high-value products, are co-produced.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin synthesis includes the following steps:

[0007] Step 1: Synthesis of thermosetting phenolic resin

[0008] Add the previous batch of oligomers, the first phenolic component, a portion of the second phenolic component, a portion of the aldehydes, and an alkaline catalyst to the polymerization reactor, stir and heat to react; then add the remaining aldehydes and the remaining second phenolic component dropwise, and continue to keep the reaction at the temperature until the meta-phenol content is ≤1% and the free phenol content is 5-30% qualified; after the reaction is completed, neutralize, dehydrate, adjust the viscosity and discharge; add catalyst 2 to the distilled water to react, then add a non-water-soluble solvent for extraction, let stand and separate into layers to obtain an oil layer of unreacted phenolic substances;

[0009] Step 2: Distillation

[0010] After the oil layer is distilled to remove the solvent, it is subjected to high-efficiency vacuum distillation to obtain at least one of phenol, o-cresol, 2,6-xylenol, p-cresol or a mixture of p-cresol and o-ethylphenol, 2,4-xylenol, p-ethylphenol or a mixture of p-ethylphenol and 2,3-xylenol, 2,4,6-trimethylphenol, 2,4-methylethylphenol, 2,3,6-trimethylphenol, p-isopropylphenol or a mixture of p-isopropylphenol and p-propylphenol; the residue is returned to the first step to participate in the synthesis of the next batch of phenolic resin.

[0011] The above scheme utilizes the difference in reaction rates between different phenols and formaldehyde under alkaline catalysis. By controlling the order of reactant addition and the depth of reaction, highly reactive meta-phenols and most phenols preferentially react with formaldehyde to generate phenolic resin polymers. Meanwhile, less reactive ortho- and para-alkylphenols, due to their slow reaction, are mostly retained in the unreacted products. During dehydration, these unreacted phenols are distilled off along with water, achieving initial separation from the resin product. The distilled aqueous phase still contains a small amount of formaldehyde and unreacted meta-, meta-, and meta-, ortho-phenols (a small amount of aldehyde can be added if necessary). Catalyst 2 is added to further react and generate water-soluble oligomers, effectively preventing impurities such as meta-phenols from mixing into the subsequent oil phase, thus ensuring the high purity of the final ortho- and para-phenol products. Solvent extraction selectively transfers the target phenols from the aqueous phase to the oil phase, completing the separation from water and water-soluble impurities.

[0012] 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.

[0013] Further, the second phenolic component is selected from at least one of 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, and m-p-propylphenol / isopropylphenol; 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.

[0014] 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%;

[0015] 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%;

[0016] 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%;

[0017] 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%.

[0018] 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%;

[0019] 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;

[0020] 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;

[0021] 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%;

[0022] 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%.

[0023] 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%.

[0024] Further, the alkaline catalyst is an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, 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, 2,3-methylethylphenol, 2,5-methylethylphenol) from the phenolic materials. The total molar amount of phenols, 2,3-methylpropylphenol, 2,5-methylpropylphenol, meta- and meta-alkylphenols (including 3,5-xylenol, 3-ethyl-5-cresol, 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 0.6 to 6 times, preferably 1.0 to 2.0 times, and 3.0 to 5.0 times; the mass of the aldehyde portion is 0 to 100% of the total aldehyde feed mass, preferably 30 to 70%.

[0025] Furthermore, the catalyst 2 is an acidic catalyst selected from oxalic acid, formic acid, phosphoric acid, or hydrochloric acid; or an alkaline catalyst selected from an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, or ammonia.

[0026] 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 phenolic material.

[0027] Furthermore, the high-efficiency vacuum distillation conditions in the second step are: pressure -0.07 to -0.1 MPa, reflux ratio 5 to 50, and number of trays 100 to 300.

[0028] Furthermore, the method can also be used to prepare phenolic resin for rock wool or sulfonated phenolic resin as a high-temperature filtration agent; by adjusting the formulation and process parameters (such as adding urea, boric acid, or carrying out a sulfonation reaction), the by-product alkylphenol can be recovered while producing the corresponding resin products.

[0029] Furthermore, the method also includes a step of further reacting unreacted meta-phenol / meta-p-phenol / meta-ortho-phenol in the distilled water with formaldehyde to reduce the impurity content in the ortho-p-phenol product.

[0030] The beneficial effects of this invention are:

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 4. Superior product quality and high separation efficiency: By utilizing the difference in reactivity for process control, the highly reactive meta-phenols are fully reacted during the resin synthesis stage, while the less reactive ortho- and para-phenols are enriched in the byproducts. Subsequently, impurities are further removed through aqueous phase "secondary polymerization" and combined with efficient distillation, ensuring the high purity of the final alkylphenol product. The prepolymer residue in the distillation kettle can be reused, realizing a closed-loop material system and reducing waste.

[0035] 5. The quality requirements for various phenolic raw materials used are low. Due to the adoption of multiple methods such as raw material prepolymerization and drip addition, the quality of phenolic raw materials such as cresol, m-p-cresol, m-p-ethylphenol, and m-p-isopropylphenol is guaranteed to be within acceptable limits. Specifically, this ensures 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 these raw materials. The hydroxymethylphenol intermediates generated by the reaction of 6-trimethylphenol, 2,4,5-trimethylphenol, and 2-ethyl-4-methylphenol 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.

[0036] 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.

[0037] 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

[0038] 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.

[0039] Figure 1 This is a process flow diagram of the synthesis of ortho- and para-alkylphenols as a byproduct of phenolic resin according to the present invention. Detailed Implementation

[0040] 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.

[0041] Example 1: Production of phenolic resin using mixed phenols with o-cresol as a byproduct

[0042] Add 8.5 parts of the previous batch of oligomers, 600 parts of coal-derived mixed phenols (containing 429.6 parts of phenol, 149.1 parts of o-cresol, and 21.3 parts of 2,6-xylenol), 15 parts of sodium hydroxide (1.5% of the total mass of phenolic materials, dissolved in 20 parts of water to form an aqueous solution), and 540 parts of 36.5% formaldehyde (the total amount of formaldehyde is 1.5 times the molar mass of phenol) to the polymerization reactor. Start stirring, heat, and raise the temperature to 45-50℃. At 60℃, open the jacket cooling water to remove the heat of reaction. After reacting for 1 hour, add the remaining 400 parts of formaldehyde dropwise, and simultaneously add the remaining 400 parts of mixed phenols dropwise over 1 hour. During this 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 10.8%, which is qualified.

[0043] After the reaction is complete, add 17 parts of glacial acetic acid to neutralize to pH 6-7. Gradually increase the vacuum to -0.08 MPa over 0.5-1 hour to begin dehydration. Observe the dehydration rate as it slows down or until the temperature drops to around 70-75℃. Then, heat the solution. During dehydration, continuously adjust the heating rate according to the rate of water output to ensure dehydration is completed at the lowest possible temperature. Control the final liquid temperature at 80℃ until the water level reaches the required value (sample analysis shows 4.3% moisture content). After passing the test, add 30 parts of ethylene glycol, stir evenly, and sample to analyze moisture and viscosity. Stop vacuuming when the moisture content reaches 2.5%. Add 20 parts of ethanol to adjust the viscosity to the specified value of 15 Pa·s. After the viscosity reaches the required level, cool to 50℃ and discharge the material, yielding 1101 parts. Test the free phenol content to 8.2%, free aldehyde content to 0.93%, solid content to 77.6%, residual carbon to 47.1%, moisture content to 2.4%, and viscosity to 15 Pa·s.

[0044] The distilled water was placed in an extraction vessel, and 1 part of 36% hydrochloric acid was added. The temperature was raised to 95-100℃ and reacted for 1 hour. The formaldehyde content was analyzed and found to be 0.2%. Then, 500 parts of methyl isobutyl ketone were added, stirred for 1 hour, and allowed to stand for 0.5 hours. The mixture separated into layers. The lower water layer was sent to the formaldehyde preparation workshop to absorb formaldehyde gas and prepare a 37% formaldehyde aqueous solution. The upper oil layer was washed once with 100 parts of water and separated into layers. The oil layer, consisting of 610.3 parts, was a solution of unreacted phenolic substances (2 parts phenol, 63.7 parts o-cresol, 33.8 parts 2,6-xylenol, and 7.3 parts prepolymer).

[0045] Step 2: Distillation of o-cresol

[0046] The 610.3 parts of the water-washed oil layer from the first step were added to a distillation vessel with 10 trays. The mixture was heated to atmospheric pressure and then reduced pressure (-0.05 MPa) to remove the solvent, resulting in 491.8 parts of solvent that were reused and then subjected to the following treatment:

[0047] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 250 trays. Distillation (-0.085 MPa, reflux ratio 25:1) yielded 46.4 parts of 99.7% o-cresol and 21.8 parts of 99.5% 2,6-xylenol. 8.9 parts of residue were left in the bottom of the distillation vessel (1.6 parts of 2,6-xylenol and 7.3 parts of prepolymer). The 8.9 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0048] Example 2: Using 2,6-xylenol as a raw material

[0049] The difference from Example 1 is that the second phenolic component is replaced with 200 + 800 parts of crude 2,6-xylenol, which is added dropwise in two batches. The first batch of 200 parts is added and mixed with the first phenolic component, and the second batch of 800 parts is added dropwise. The same expressions used in the following examples and comparative examples are synonymous with this; (containing 176 parts of o-cresol, 102 parts of p-cresol, 184.5 parts of m-cresol, 2.5 parts of o-ethylphenol, and 535 parts of 2,6-xylenol). The first phenolic component is 1000 parts of 97.9% coal-fired phenol and 40.1 parts of the previous batch of oligomers. The catalyst is replaced with 31% liquid alkali (2.5% dosage). The total formaldehyde dosage was 1.9 times the total molar amount of phenol and m-cresol (900 parts as a base + 1000 parts added dropwise); the resulting phenolic resin consisted of 5.2% free phenol, 0.89% free aldehyde, 78.3% solids, 47.7% residual carbon, 2.8% moisture, and a viscosity of 16 Pa·s. After distillation of the by-product phenol, 102.1 parts of 99.8% phenol, 86.7 parts of 99.7% o-cresol, 316.7 parts of 99.8% 2,6-xylenol, and 44 parts of 98.4% p-cresol were obtained. 40.4 parts of the prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0050] Example 3: Using m-p-cresol as a raw material

[0051] The difference from Example 1 is that the second phenolic component is changed to 500 parts of m-cresol as a base and 500 parts added dropwise (containing 359 parts of p-cresol, 616 parts of m-cresol, 2 parts of o-ethylphenol, 15.4 parts of 2,4-xylenol, and 7.6 parts of 2,5-xylenol). The first phenolic component is 2000 parts of 99.2% coal-derived phenol and 18.1 parts of the previous batch of oligomers. The catalyst is changed to 60 parts of 20% ammonia water. The amount of 36.5% formaldehyde is 1.5 times the total molar amount of phenol, m-cresol, and 2,5-xylenol, with 0 parts added as a base and 3300 parts added dropwise. 3474 parts of phenolic resin were obtained, and the free phenol content was 3.2%, the free aldehyde content was 0.85%, the solid content was 78.1%, the residual carbon content was 47.9%, the moisture content was 2.3%, and the viscosity was 18 Pa·s. After distillation of the by-product phenol, 125.8 parts of 99.8% phenol and 188.3 parts of 99.7% p-cresol were obtained. 18.2 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0052] Example 4: Using 2,4 / 2,5-xylenol as a raw material

[0053] The difference from Example 1 is that the second phenolic component is changed to 200 parts + 800 parts of 2,4 / 2,5-xylenol (containing 48 parts of p-cresol, 53 parts of m-cresol, 94 parts of 2,3-xylenol, 86 parts of 2-ethyl-6-cresol, 428 parts of 2,4-xylenol, and 291 parts of 2,5-xylenol), the first phenolic component is 1000 parts of 99.2% coal-fired phenol and 49.5 parts of the previous batch of oligomers, the catalyst is 31% liquid alkali (3.1% dosage), and the total dosage of 36.5% formaldehyde is 969 parts + 1000 parts, which is 1.7 times the total molar amount of phenol, m-cresol, 2,5-xylenol, and 2,3-xylenol. The obtained phenolic resin was 1785.6 parts, and the free phenol content was 3.9%, the free aldehyde content was 0.79%, the solid content was 80.6%, the residual carbon content was 48.9%, the moisture content was 2.4%, and the viscosity was up to 15 Pa·s. The by-product phenols were mainly 21.2 parts of 99.6% p-cresol and 338.6 parts of a mixture of 99.67% 2,4-xylenol / 2-ethyl-6-cresol. The prepolymer of 49.6 parts was returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0054] Example 5: Using m-p-ethylphenol as a raw material

[0055] The difference from Example 1 is that the second phenolic component is changed to 600 parts + 600 parts of m- and p-ethylphenol (containing 470 parts of p-ethylphenol, 533 parts of m-ethylphenol, 116 parts of 2,3-xylenol, 48 parts of 3,5-xylenol, 30 parts of 2,4 / 2,5-xylenol, and 3 parts of 2,4 / 2,5-methylethylphenol), the first phenolic component is 1000 parts of 99.9% petrochemical phenol and 25.7 parts of the previous batch of oligomers, the catalyst is 103 parts of 31% liquid alkali, and the 36.5% formaldehyde is added at 1.5 times the total molar amount of phenol, m-ethylphenol, 3,5-xylenol, 2,3-xylenol, 2,5-xylenol, and 2,5-methylethylphenol, plus 0 + 3275 parts. The obtained phenolic resin was 2082.6 parts, and the free phenol content was 3.8%, the free aldehyde content was 0.88%, the solid content was 80.8%, the residual carbon content was 48.8%, the moisture content was 2.2%, and the viscosity was 15 Pa·s. The by-product phenol was distilled to obtain 212.8 parts of 99.9% phenol and 239.9 parts of 95.8% p-ethylphenol (which can be crystallized and purified to 99.2%). 25.9 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0056] Example 6: Using crude 2,4,6-trimethylphenol as raw material

[0057] The difference from Example 1 is that the first phenol component is changed to 500 parts of 99.2% coal-fired phenol and 25.8 parts of the previous batch of oligomers. The second phenol component is 1000 parts + 0 parts of crude 2,4,6-trimethylphenol (containing 86 parts of p-ethylphenol, 102 parts of m-ethylphenol, 183 parts of 3,5-xylenol, 45 parts of 3,4-xylenol, 511 parts of 2,4,6-trimethylphenol, 52 parts of 2,4-methylethylphenol, and 21 parts of 2,5-methylethylphenol), 242 parts of 31% liquid alkali (5% of the total phenol raw materials), the catalyst is 31% liquid alkali (5% of the dosage), and the dosage of 36.5% formaldehyde is 1130 parts + 0 parts, which is 1.7 times the total molar amount of phenol, m-ethylphenol, 3,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol. 1128 parts of phenolic resin were obtained, and the free phenol content was 4.5%, the free aldehyde content was 0.79%, the solid content was 82.3%, the residual carbon content was 51.2%, the moisture content was 2.7%, and the viscosity was 17 Pa·s. The by-product phenol was distilled to obtain 17 parts of 99.6% p-ethylphenol, high-purity 2,4,6-trimethylphenol and 2,4-methylethylphenol. 25.6 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0058] Example 7: Using 2,4 / 2,5-methylethylphenol as a raw material

[0059] The difference from Example 1 is that the second phenolic component is changed to 400 parts + 600 parts of 2,4 / 2,5-methylethylphenol (containing 37 parts of p-ethylphenol, 42 parts of m-ethylphenol, 95 parts of 3,5-xylenol, 148 parts of 3,4-xylenol, 63 parts of 2,3,6-trimethylphenol, 428 parts of 2,4-methylethylphenol, and 187 parts of 2,5-methylethylphenol). The first phenolic component is 1000 parts of 99.2% coal-derived phenol and 32.7 parts of the previous batch of oligomers. The catalyst is 31% liquid alkali (4% dosage). The dosage of 36.5% formaldehyde is 745 parts + 1000 parts, which is 1.5 times the total molar amount of phenol, m-ethylphenol, 3,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol. The obtained phenolic resin was 1962.5 parts, and the free phenol content was 4.1%, the free aldehyde content was 0.72%, the solid content was 81.1%, the residual carbon content was 49.8%, the moisture content was 2.7%, and the viscosity was 17 Pa·s. The by-product phenol was distilled to obtain 11.9 parts of 99.5% p-ethylphenol and high-purity 2,4-methylethylphenol. 32.9 parts of the prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0060] Example 8: Using 3,4-xylenol / 2,3,6-trimethylphenol as raw materials and adding them in steps.

[0061] The difference from Example 1 is that the second phenolic component is changed to 0 parts + 1000 parts of 3,4-xylenol / 2,3,6-trimethylphenol (containing 24 parts of p-ethylphenol, 26 parts of m-ethylphenol, 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). The first phenolic component is 1000 parts of 99.2% coal-derived phenol and 57.9 parts of the previous batch of oligomers. The feeding method is to first prepolymerize all the phenol with formaldehyde and then add the second phenolic component dropwise. The amount of 36.5% formaldehyde is 2270 parts + 0 parts, which is 1.95 times the total molar mass of phenol, m-ethylphenol, 3,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol. 1973 parts of phenolic resin were obtained, and the free phenol content was 5.2%, the free aldehyde content was 0.87%, the solid content was 82.3%, the residual carbon content was 50.5%, the moisture content was 2.9%, and the viscosity was up to 15 Pa·s. The by-product phenol was distilled to obtain 193.8 parts of 99.2% 2,3,6-trimethylphenol and 58.2 parts of prepolymer, which were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0062] Example 9: Using m-p-isopropylphenol as a raw material

[0063] The difference from Example 1 is that the second phenolic component is changed to 800 parts of m-, p-isopropylphenol + 800 parts of methyl-, p-isopropylphenol (containing 71 parts of 3,4-xylenol, 4 parts of 2,3,6-trimethylphenol, 464 parts of p-isopropylphenol, 635 parts of m-isopropylphenol, 126 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, 2,4-... (3 parts of 2,5-methylethylphenol, 54 parts of 2,4,5-trimethylphenol), the first phenolic component is 1000 parts of 99.2% coal-processed phenol, the catalyst is 168 parts of 31% liquid alkali, and the dosage of 36.5% formaldehyde is 1.65 times the total molar amount of phenol, 3,4-dimethylphenol, m-isopropylphenol / m-propylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, and 2,3,5-trimethylphenol, plus 2480 parts + 0 parts. The obtained phenolic resin was 2679.8 parts, and the free phenol content was 5.86%, the free aldehyde content was 0.98%, the solid content was 82.5%, the residual carbon content was 50.9%, the moisture content was 2.8%, and the viscosity was up to 15 Pa·s. The by-product phenol was distilled to obtain 82.5 parts of 99.8% phenol and 335.9 parts of a 98.15% p-isopropylphenol / p-propylphenol mixture. 34.9 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0064] Example 10: Using mixed phenols as raw materials

[0065] The difference from Example 1 is that the phenol and second phenol components in the first component are not used. Instead, 1000 parts of mixed phenols in the first component (containing 610.4 parts of phenol, 104.3 parts of o-cresol, 2.8 parts of 2,6-xylenol, 97.5 parts of p-cresol, 173.9 parts of m-cresol, 2.3 parts of o-ethylphenol, 5.6 parts of 2,4-xylenol, and 3.2 parts of 2,5-xylenol) are used as raw materials, along with 10.3 parts of the previous batch of oligomers, 97 parts of 31% liquid alkali as catalyst, and 36.5% formaldehyde at a dosage of 1.49 times the total molar amount of phenol, m-cresol, and 2,5-xylenol (986 parts + 0 parts). 1069 parts of phenolic resin were obtained, with 3.25% free phenol, 0.79% free aldehyde, 78.8% solid content, 47.2% residual carbon, 2.5% moisture, and a viscosity of 17 Pa·s. The by-product phenol was distilled to obtain 30.9 parts of 99.6% phenol, 60.5 parts of 99.6% o-cresol, and 49.7 parts of 97.8% p-cresol. 10.2 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0066] Example 11: Prepolymerization using pyrocresol as raw material

[0067] The difference from Example 1 is that the first phenolic component is 500 parts of 99.9% petrochemical phenol and 14.2 parts of the previous batch of oligomers; the second phenolic component is 400 parts + 600 parts of coking cresol (containing 90.5 parts of phenol, 203 parts of o-cresol, 5 parts of 2,6-xylenol, 229 parts of p-cresol, 412 parts of m-cresol, 2.5 parts of o-ethylphenol, 38.5 parts of 2,4-xylenol, and 19.5 parts of 2,5-xylenol); the catalyst is 97 parts of 31% liquid alkali; the process involves mixing phenol with a portion of cresol and then adding the remaining cresol dropwise; and the amount of 36.5% formaldehyde is 1.67 times the total molar amount of phenol, m-cresol, and 2,5-xylenol (0 parts + 1390 parts). 1397 parts of phenolic resin were obtained, with 3.61% free phenol, 0.91% free aldehyde, 78.6% solid content, 47.5% residual carbon, 2.2% moisture, and a viscosity of 14 Pa·s. The by-product phenol was distilled to obtain 91.1 parts of 99.8% phenol, 110 parts of 99.7% o-cresol, and 107.9 parts of 98.4% p-cresol. 14.1 parts of prepolymer were returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0068] Example 12: Prepolymerization using only the second phenolic components, p-cresol and 2,4 / 2,5-xylenol, without using the first phenolic component, was carried out.

[0069] The difference from Example 1 is that the second phenolic component consists of 2000 parts of coking m-cresol (base) (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) + 500 parts of gasified phenol extract 2,4 / 2,5-xylenol (dropped) (containing 6.5 parts of p-cresol, 11 parts of m-cresol, and 2,3-xylenol). The reagents consist of 18 parts cresol, 274.5 parts 2,4-xylenol, and 190 parts 2,5-xylenol. The catalyst is 242 parts 31% liquid alkali. The process involves reacting m-cresol with a portion of the formaldehyde first, followed by the addition of the remaining formaldehyde and 2,4 / 2,5-xylenol. The amount of 36.5% formaldehyde is 1.7 times the total molar amount of m-cresol, 2,5-xylenol, and 2,3-xylenol (1000 parts + 838 parts). The obtained phenolic resin was 2526.1 parts, and the free phenol content was 7.8%, the free aldehyde content was 0.91%, the solid content was 78.8%, the carbon residue was 47.2%, the moisture content was 2.4%, and the viscosity was 14 Pa·s. The by-product phenol was distilled to obtain 326.4 parts of 99.7% p-cresol and 153.7 parts of 99.6% 2,4-xylenol. The bottom residue of the tower was 98.4 parts (3.3 parts of 2,4-xylenol and 95.1 parts of prepolymer). The prepolymer was returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0070] Example 13: Prepolymerization using only the second phenolic component (p-ethylphenol as a base) and crude 2,4,6-trimethylphenol (drop-added) without using the first phenolic component.

[0071] The difference from Example 1 is that the second phenolic component consists of m-p-ethylphenol extracted from tar (as a base) + crude 2,4,6-trimethylphenol extracted from tar (added dropwise), with 25% ammonia as the catalyst. The process involves reacting m-p-ethylphenol with a portion of the formaldehyde first, followed by the dropwise addition of the remaining formaldehyde and crude 2,4,6-trimethylphenol. After the reaction, the product is directly distilled without neutralization to generate phenolic resin, as detailed below:

[0072] In the polymerization reactor, stirring was started, and the following were added sequentially: 127.2 parts of the previous batch of prepolymer, 1000 parts of m-p-ethylphenol extracted from the second phenolic component tar (96.7 parts of 2,3-xylenol, 14.5 parts of 2,4-xylenol, 10.5 parts of 2,5-xylenol, 391.7 parts of p-ethylphenol, 444.2 parts of m-ethylphenol, 40 parts of 3,5-xylenol, 1.6 parts of 2,4-methylethylphenol, and 0.8 parts of 2,5-methylethylphenol), and 4 parts of 25% ammonia water. 00 parts (5% of the total phenol raw material), 1000 parts (37% formaldehyde, the total formaldehyde content is twice the total molar mass of m-ethylphenol, 2,3-xylenol, 2,5-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 stirrer, heat, raise the temperature to 60-70℃, open the jacket cooling water to remove the heat of reaction, slowly raise the temperature to 85-90℃, and hold for 2 hours. Then, at 85–90°C, add the remaining 312 parts of 37% formaldehyde, 500 parts of the second component crude 2,4,6-trimethylphenol (43 parts of p-ethylphenol, 51 parts of m-ethylphenol, 91.5 parts of 3,5-dimethylphenol, 26 parts of 2,4-methylethylphenol, 10.5 parts of 2,5-methylethylphenol, 255.5 parts of 2,4,6-trimethylphenol, and 22.5 parts of 3,4-dimethylphenol), and 500 parts of 2,4 / 2,5-dimethylphenol (6.5 parts of p-cresol, ... A mixture of 11 parts m-cresol, 18 parts 2,3-xylenol, 274.5 parts 2,4-xylenol, and 190 parts 2,5-xylenol was added dropwise over 3 hours. After the addition was complete, the mixture was kept at 90°C for 5 hours before sampling and analysis. Liquid chromatography analysis showed that the levels of m / ortho- and m / para-phenols were 0.31% (2,3-xylenol, 2,5-xylenol, 3,4-xylenol, and 2,5-methylethylphenol), and the free phenol level was 22.68%, which met the acceptable standards.

[0073] After the reaction was completed, the vacuum was gradually increased to -0.095 MPa over 2 hours for dehydration. During dehydration, the water in the upper part of the water separator was returned to the reactor through the water separator on the reactor. The dehydration rate was observed to slow down or until the temperature dropped to 70°C. Heating was then resumed for dehydration for about 1 hour. At this point, the distilled water was directly fed into the phenol water receiving tank. After 3 hours, the liquid temperature in the reactor reached 80°C. The moisture content of the material was 3.3%, which is acceptable. 55 parts of ethylene glycol were added and stirred evenly. The moisture content and viscosity were analyzed. The vacuum was stopped when the moisture content was 3.0%. 20 parts of ethanol were added to adjust the viscosity to 16 Pa·s. The material was cooled to 50°C and discharged, yielding 1812.1 parts. The free phenol content was 6.8%, the free aldehyde content was 0.93%, the solid content was 80.5%, the residual carbon content was 49.3%, the moisture content was 3.0%, and the viscosity was adjusted to 17 Pa·s.

[0074] Add 3 parts hydrochloric acid and 10 parts 37% formaldehyde to the distilled water, heat to 100℃ and react for 2 hours. Sampling and analysis showed that 0.06% of 2,3-xylenol / 2,5-xylenol / 3,4-xylenol / 2,5-methylethylphenol was within acceptable limits. After 0.5 hours, cool the material to 60℃, add 2000 parts methyl isobutyl ketone, stir for 1 hour, let stand for 0.5 hours, and allow to separate into layers. Recover 7.9 parts methyl isobutyl ketone from the lower water layer and send it to the wastewater treatment workshop (wastewater approximately 1...). 402.5 parts), the upper oil layer was washed once with 100 parts of water, and the resulting oil layer was an unreacted phenolic solution of 2710.1 parts (1.9 parts of p-cresol, 0.1 parts of 2,3-xylenol, 213.8 parts of 2,4-xylenol, 0.2 parts of 2,5-xylenol, 160.3 parts of p-ethylphenol, 20.8 parts of 2,4-methylethylphenol, 0.1 parts of 2,5-methylethylphenol, 218.7 parts of 2,4,6-trimethylphenol, and 122.2 parts of prepolymer).

[0075] Step 2: Distillation of p-ethylphenol, 2,4,6-trimethylphenol, etc.

[0076] The 2710.1 parts of the water-washed oil layer from the first step were added to a distillation vessel with 20 trays. The temperature was raised first to atmospheric pressure, then reduced to vacuum (-0.06 MPa) to distill off 1956 parts of solvent. This was then reused and subjected to the following treatment:

[0077] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 300 trays. Distillation (-0.09 MPa, reflux ratio 20-40:1) yielded 190.5 parts of 99.8% 2,4-xylenol, 83.6 parts of 99.7% p-ethylphenol, 155 parts of a p-ethylphenol / 2,4,6-trimethylphenol mixture (73.8 parts of p-ethylphenol and 81.2 parts of 2,4,6-trimethylphenol), 88.6 parts of 99.2% 2,4,6-trimethylphenol, and 63.6 parts of a 2,4,6-trimethylphenol / 2,4-methylethylphenol mixture (46.9 parts of 2,4,6-trimethylphenol, 16.5 parts of 2,4-methylethylphenol, and 0.2 parts of other phenols). 127 parts of residue were collected from the distillation vessel (4.8 parts of phenol and 122.2 parts of prepolymer). The prepolymer was returned to the polymerization reactor for the next batch of phenolic resin synthesis.

[0078] Comparative Example 1: Production of general-purpose phenolic resin using traditional pure phenol process

[0079] In a 2000L jacketed enamel-lined reactor, 800kg of 99.9% petrochemical phenol, 12kg of sodium hydroxide, and 1020kg of 36.5% formaldehyde are fed in sequence (the sodium hydroxide is dissolved in 20kg of water). Steam is passed through the jacket to raise the temperature. The steam is turned off when the temperature reaches about 40-45℃, and the steam in the jacket is turned off again when the temperature reaches about 50-55℃. The steam in the jacket is then discharged, and an appropriate amount of cooling water is passed through. The temperature is slowly raised to 80-85℃ and maintained for 2 hours. The temperature changes of the materials before and after the steam and cooling water are turned on and off should be carefully observed.

[0080] After the reaction was complete, 13.2 kg of glacial acetic acid was added to neutralize to pH 6.5. The pH was maintained for 10 minutes and then sampled and retested. Dehydration began. The vacuum was gradually controlled to -0.075 MPa over 1 hour. The dehydration rate was observed to slow down and the temperature dropped to 70°C. The jacket was then turned on for steam heating. During dehydration, the steam output was continuously adjusted according to the rate of water output to ensure that dehydration was completed at the lowest possible temperature. Steam was continuously supplied during the later stages of dehydration to control the final liquid temperature at 80°C. When the water level reached the required value (638 kg), a sample was taken to analyze the moisture content and viscosity. When the moisture content was 2.7%, the vacuum was stopped, and 40 kg of ethylene glycol was added and stirred for 0.5 hours. The viscosity was sampled at 28 Pa·s. Then, 10 kg of anhydrous ethanol was used to adjust the viscosity to 18 Pa·s.

[0081] After the viscosity reaches the required level, the material is cooled to 50°C and discharged, yielding 1030 kg of liquid. Tests showed 8.8% free phenol, 1.21% free aldehyde, 75.8% solid content, 45.6% residual carbon, 2.6% moisture, and a viscosity of 18 Pa·s.

[0082] Compared with Examples 1-13, the resin performance is comparable, but all of them use high-priced petrochemical raw materials and have no high-value by-product phenols. The resin solid content and residual carbon content are lower than those of Examples 1-13.

[0083] Example 14: Production of phenolic resin for rock wool (using mixed phenols)

[0084] The process route differs from Example 1 in that, in this example, phenolic resin for rock wool is produced using 2000 parts of the first phenolic component mixed phenol (1432 parts of phenol and 568 parts of o-cresol). Under alkaline conditions (sodium hydroxide at 6% of the mass of the mixed phenol), it reacts with a large amount of formaldehyde (molar ratio of formaldehyde to phenol in the mixed phenol 4.79) at 85°C. After passing the reaction, without dehydration, 40 parts of boric acid, 1500 parts of urea, and 1800 parts of water are added directly after cooling. The mixture is stirred and reacted for 1 hour, then cooled to 40°C and discharged to obtain 11532 parts of qualified reddish-brown transparent liquid rock wool resin with a solid content of 42.32%, viscosity of 7.8 mPa·s, pH of 9, free phenol of 0.39%, and free aldehyde of 0.45%.

[0085] Example 15: Production of phenolic resin for rock wool (using m-p-cresol)

[0086] The difference from Example 14 is that the raw materials are 2000 parts of 99.2% coal-fired phenol (first phenol component) and 1000 parts of coking m-cresol (second phenol component) (containing 359 parts of p-cresol, 639 parts of m-cresol, and 2 parts of o-ethylphenol), sodium hydroxide at 5.28% of the mass of the first and second phenol components, formaldehyde (molar ratio of formaldehyde to phenol and m-cresol in phenolic materials is 3.94), 150 parts of boric acid, 2500 parts of urea, and 2500 parts of water; 17192.6 parts of qualified reddish-brown transparent liquid rock wool resin are obtained, with a solid content of 43.12%, viscosity of 8.2 mPa·s, pH of 8.3, free phenol of 0.41%, and free aldehyde of 0.43%.

[0087] Example 16: Production of phenolic resin for rock wool (using m-p-ethylphenol)

[0088] The difference from Example 14 is that the raw materials are 2000 parts of 99.2% coal-fired phenol (first phenol component) and 1200 parts of p-ethylphenol (second phenol component) (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), and sodium hydroxide is 5.25% of the mass of the first and second phenol components. Formaldehyde (molar ratio of formaldehyde to phenol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, and 2,5-methylethylphenol in a ratio of 4.08), boric acid 150 parts, urea 2500 parts, and water 2500 parts were used to obtain 17688.1 parts of qualified reddish-brown transparent liquid rock wool resin, with a solid content of 43.55%, viscosity of 7.5 mPa·s, pH of 8.5, free phenol of 0.44%, and free aldehyde of 0.47%.

[0089] Example 17: Production of phenolic resin for rock wool (using m-p-isopropylphenol)

[0090] The difference from Example 14 is that the raw materials are 2000 parts of 97.8% coal-fired phenol (first phenol component) and 1600 parts of p-isopropylphenol (second phenol component) (containing 71 parts of 3,4-xylenol, 4 parts of 2,3,6-trimethylphenol, 504 parts of p-isopropylphenol, 635 parts of m-isopropylphenol, 136 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 4 parts of 2,4,5-trimethylphenol), and sodium hydroxide is... The following components were added: 5.5% by mass of the first and second phenolic components, formaldehyde (molar ratio of formaldehyde to phenol, 3,4-xylenol, m-isopropylphenol, m-propylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, 2,3,5-trimethylphenol, and 2,5-methylethylphenol in the phenolic materials was 4.44), 100 parts of boric acid, 2900 parts of urea, and 3500 parts of water; 20747.6 parts of qualified reddish-brown transparent liquid rock wool resin were obtained, with a solid content of 43.89%, viscosity of 8.8 mPa·s, pH of 8.4, free phenol of 0.41%, and free aldehyde of 0.43%.

[0091] Example 18: Production of phenolic resin for rock wool (using a mixture of multiple phenols)

[0092] The difference from Example 14 is that the raw materials are: 2000 parts of 95.2% coal-processed 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 and m-ethylphenol). The product contained 266 parts of methylphenol, 58 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, 2 parts of 2,4 / 2,5-xylenol, and 2 parts of 2,4 / 2,5-methylethylphenol, and 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, and 3-ethyl-5-methyl... A mixture of phenols (20 parts, 2,3,5-trimethylphenol, 11 parts, 1 part, 2,4 / 2,5-methylethylphenol, 1 part, 2,4,5-trimethylphenol) in a quantity of 5300 parts, sodium hydroxide at 5.89% of the mass of the first and second phenolic components, and formaldehyde (formaldehyde mixed with phenol, m-cresol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, 2,5-methylethylphenol, 3...). The following were prepared: 4-dimethylphenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, and 2,3,5-trimethylphenol in a molar ratio of 4.41; 150 parts of boric acid; 4000 parts of urea; and 5300 parts of water; 30029.1 parts of qualified reddish-brown transparent liquid rock wool resin were obtained, with a solid content of 43.26%, a viscosity of 8.6 mPa·s, a pH of 8.9, 0.48% free phenol, and 0.47% free aldehyde.

[0093] Example 19: Production of phenolic resin for rock wool (stepwise feeding)

[0094] The difference from Examples 14 and 17 is that a stepwise feeding method is used: first, 2000 parts of 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), and alkaline solution (sodium hydroxide at 5.89% of the mass of the first and second phenol components) are added to the reactor; then, 600 parts of m-cresol (second phenol component, including 264 parts of p-cresol and 278 parts of m-cresol) are simultaneously added dropwise. The second phenolic component contains 58 parts of o-ethylphenol, 600 parts of m-ethylphenol (containing 248 parts of m-ethylphenol, 266 parts of 2,3-xylenol, 24 parts of 3,5-xylenol, 2 parts of 2,4 / 2,5-xylenol, and 2 parts of 2,4 / 2,5-methylethylphenol), and 600 parts of m-isopropylphenol (containing 26 parts of 3,4-xylenol, 2 parts of 2,3,6-trimethylphenol, and 24 parts of p-isopropylphenol). The second component, a mixture consisting of 0 parts of m-isopropylphenol, 294 parts of m-isopropylphenol, 5 parts of 2,3-methylethylphenol, 20 parts of 3-ethyl-5-cresol, 11 parts of 2,3,5-trimethylphenol, 1 part of 2,4 / 2,5-methylethylphenol, and 1 part of 2,4,5-trimethylphenol, is then added dropwise with formaldehyde (formaldehyde mixed with phenolic materials containing phenol, m-cresol, m-ethylphenol, 2,3-xylenol, 3,5-xylenol, 2,5-xylenol, 2,5-methylethylphenol, 3,4...). The reaction was carried out with xylenol, m-isopropylphenol, 2,3-methylethylphenol, 3-ethyl-5-methylphenol, and 2,3,5-trimethylphenol in a molar ratio of 4.66. After the sample passed the test, 150 parts of boric acid, 4000 parts of urea, and 5000 parts of water were added to obtain 30566.4 parts of qualified reddish-brown transparent liquid rock wool resin, with a solid content of 42.88%, a viscosity of 7.1 mPa·s, a pH of 8.8, 0.40% free phenol, and 0.41% free aldehyde.

[0095] Example 20: Coupling of dehydration and phenol recovery in rock wool resin process

[0096] The difference from Example 14 is that after the rock wool resin reaction is qualified, a low-temperature dehydration operation is attempted. Phenol and p-cresol are recovered from the dehydrated material. At the same time, the free phenol in the resin is reduced and the solid content is increased.

[0097] In a stainless steel polymerization reactor equipped with a reflux condenser and an internal coil, 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) were added. 330 parts of 48% liquid alkali (sodium hydroxide being 5.28% of the mass of the first and second phenolic components) were pumped into the reactor. After the phenolic materials and liquid alkali were added, the reactor (heated by a steam jacket) was raised to 85°C. After the temperature was raised, 7780 parts of 36.5% formaldehyde (molar ratio of formaldehyde to phenol and m-cresol in the phenolic materials was 3.48) were added dropwise to the reactor from a formaldehyde metering tank within 2 hours. The reactor temperature was maintained at 75–80°C. After the addition was complete, the reactor temperature was maintained at 90°C for 1 hour. Gel chromatography analysis showed 0.01% m-cresol and 3.5% phenol, which was acceptable. (This step is basically the same as in Example 14, and not much different from Examples 1-13.)

[0098] The material was cooled to 50°C, and a vacuum of -0.09 MPa was applied to maintain the temperature below 50°C for dehydration for 2 hours. At this point, the amount of oily substance in the dehydrated liquid was minimal, and dehydration was stopped. A total of 3260 parts of liquid were distilled off. The dehydrated liquid was extracted twice with 500 parts of methyl isobutyl ketone each, yielding 1334.7 parts of a methyl isobutyl ketone solution of p-cresol / phenol (112 parts of phenol and 233.5 parts of p-cresol). The aqueous layer after extraction was added to a dehydration reactor and heated to remove 6.3 parts of methyl isobutyl ketone from the water for reuse. The aqueous layer after removing the methyl isobutyl ketone was then subjected to the following operation. (This step differs from Example 14 but is the same as in Examples 1-13.)

[0099] The aqueous layer, after solvent removal, is added to the polymerization reactor and mixed with the materials already in the reactor. Stirring is started for 1 hour, maintaining the material temperature at 50°C. 150 parts of boric acid are added and stirred for 0.5 hours. Then, 2500 parts of urea are added and stirred for 1.5 hours. After thorough mixing, 2500 parts of water are added. The mixture is discharged after the temperature drops below 40°C. 15745.2 parts of a reddish-brown transparent liquid are obtained, with a solid content of 44.23%, a viscosity of 8.9 mPa·s, a pH of 8.1, 0.26% free phenol, and 0.62% free aldehyde. (This step is the same as in Example 14.)

[0100] 1334.7 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 974.3 parts of solvent. The remaining solution was reused and then subjected to the following treatment:

[0101] The material in the distillation vessel was transferred to a high-efficiency distillation vessel with 160 trays, and 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. (This step differs from Example 14, but is the same as in Examples 1-13.)

[0102] Comparative Example 2: Production of Rock Wool Resin using Traditional Pure Phenol Process

[0103] The difference from Example 14 is that the raw materials are 1000 parts of 99.9% petrochemical phenol, 5.04% sodium hydroxide by mass of petrochemical phenol, formaldehyde (aldehyde-phenol molar ratio 3.35), 25 parts of boric acid, 750 parts of urea, and 1000 parts of water; 5752 parts of qualified reddish-brown transparent liquid rock wool resin were obtained, with a solid content of 41.72%, viscosity of 8 mPa·s, pH of 7.9, free phenol of 0.82%, and free aldehyde of 0.68%; it is comparable to Examples 14-20, but the raw material cost is significantly higher.

[0104] Example 21: Production of high-temperature filtration agent for sulfonated phenolic resin (using mixed phenols)

[0105] In this example, sulfonated phenolic resin (high-temperature filtration agent) is produced by reacting 225.7 parts of the first phenolic component (coal-processed mixed phenols, 82.01% phenol, 17.99% o-cresol) and 130 parts of 36.5% formaldehyde at 80°C and pH 9 (adjusted with 31% liquid alkali) for 2 hours; then, 40.5 parts of 36.5% formaldehyde, 41.6 parts of sodium bisulfite, and 12.6 parts of sodium sulfite (adjusted to pH 5-6) are reacted at 90°C for 2 hours; finally, the two reaction solutions are mixed and reacted according to the sulfonation process for 3 hours. (The pH was adjusted to 9 using 31% liquid alkali, and the temperature was 85-90℃). After polycondensation, water and unreacted phenol were removed by vacuum distillation to obtain 296.1 parts of qualified sulfonated resin (46.6% effective component). The distillate was subjected to secondary polymerization (0.05 parts of 36% hydrochloric acid catalysis, 95℃ for 2 hours), extraction (100 parts of isobutyl ketone extraction), and distillation (-0.085MPa, reflux ratio 20:1) to recover 11.4 parts of 99.8% phenol and 20.2 parts of 99.6% o-cresol.

[0106] Example 22: Production of high-temperature filtration agent for sulfonated phenolic resin (using m-p-cresol)

[0107] The difference from Example 21 is that the raw materials are 207 parts of the first phenol component (99.2% coal-derived phenol) and 288 parts of the second phenol component (m-p-cresol (47.15% m-cresol, 44.93% p-cresol, 7.92 parts o-ethylphenol) obtained by crude phenol distillation from coal tar, 245 parts of 36.5% formaldehyde; 81 parts of 36.5% formaldehyde, 83 parts of sodium bisulfite, and 25 parts of sodium sulfite; the resulting sulfonated resin is 613.2 parts, which meets the performance requirements (47.2% effective component), and the distillate is recovered to obtain 80.9 parts of a 99.9% p-cresol / o-ethylphenol mixture.

[0108] Example 23: Production of high-temperature filtration agent for sulfonated phenolic resin (using m-p-ethylphenol)

[0109] The difference from Example 21 is that the raw materials are 208 parts of 99.2% coal-fired phenol (first phenol component) and 325 parts of coal-fired m- and p-ethylphenol (containing 41.25% p-ethylphenol, 44.42% m-ethylphenol, 9.67% 2,3-xylenol, 4% 3,5-xylenol, 0.42% 2,4 / 2,5-xylenol, and 0.24% 2,4 / 2,5-methylethylphenol). The resulting sulfonated resin is 641.8 parts, which meets the performance requirements (47.7% effective component). The distillate is recovered to obtain 92.8 parts of a 2,3-xylenol / p-ethylphenol mixture.

[0110] Example 24: Production of high-temperature filtration agent for sulfonated phenolic resin (using m- and p-isopropylphenol)

[0111] The difference from Example 21 is that the raw materials are 208 parts of the first phenolic component (99.9% petrochemical phenol) and 362 parts of the second phenolic component (coal-processed m-p-isopropylphenol, containing 44.83% p-isopropylphenol, 46.33% m-isopropylphenol, and 8.84% 3-ethyl-5-cresol); the resulting sulfonated resin is 659.6 parts, with qualified performance (48.3% effective component), and the distillate is recovered to obtain 107.3 parts of 99.1% p-isopropylphenol.

[0112] Example 25: Production of high-temperature filtration agent for sulfonated phenolic resin (using only the second phenolic component m-p-cresol)

[0113] The difference from Example 21 is that the raw materials are 621 parts of the second phenolic component, obtained by distillation of crude phenol extracted from coal tar, containing m-p-cresol (47.15% m-cresol, 44.93% p-cresol, and 7.92 parts o-ethylphenol), 350 parts of 36.5% formaldehyde, 81 parts of 36.5% formaldehyde, 83 parts of sodium bisulfite, and 25 parts of sodium sulfite. After the reaction is completed, water and free phenol are distilled off, and 20 parts of water are added to the reaction material. The resulting sulfonated resin is 761.3 parts, which meets the performance requirements (48.7% effective component). The distillate is recovered to obtain 176.9 parts of a 99.7% p-cresol / o-ethylphenol mixture.

[0114] Comparative Example 3: Production of Sulfonated Phenolic Resin using Traditional Pure Phenol Process

[0115] The difference from Example 21 is that the raw materials are 206.8 parts of 99.9% petrochemical phenol and 121.6 parts of 36.5% formaldehyde; after polycondensation, water and unreacted phenol are removed by vacuum distillation to obtain 284.2 parts of qualified sulfonated resin (46.0% effective component); the distillate is not subjected to extractive distillation.

[0116] Pure petrochemical phenol was used to produce the resin using the sulfonation process described in Example 21. The resulting sulfonated resin had comparable properties, but no integrated byproduct phenol recovery and refining step was included.

[0117] 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 adjustment, produce a variety of qualified phenolic resins such as general-purpose, rock wool, and sulfonated resins, and simultaneously and efficiently co-produce a variety of high-purity, high-value-added alkylphenols, with significant economic benefits and advantages in comprehensive resource utilization.

[0118] 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.

[0119] 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 ortho- and para-alkylphenols as a byproduct of phenolic resin synthesis, characterized in that, Includes the following steps: Step 1: Synthesis of thermosetting phenolic resin Add the previous batch of oligomers, the first phenolic component, a portion of the second phenolic component, a portion of the aldehydes, and an alkaline catalyst to the polymerization reactor, stir and heat to react; then add the remaining aldehydes and the remaining second phenolic component dropwise, and continue to keep the reaction at the temperature until the meta-phenol content is ≤1% and the free phenol content is 5-30% qualified; after the reaction is completed, neutralize, dehydrate, adjust the viscosity and discharge; add catalyst 2 to the distilled water to react, then add a non-water-soluble solvent for extraction, let stand and separate into layers to obtain an oil layer of unreacted phenolic substances; Step 2: Distillation After the oil layer is distilled to remove the solvent, it is subjected to high-efficiency vacuum distillation to obtain at least one of phenol, o-cresol, 2,6-xylenol, p-cresol or a mixture of p-cresol and o-ethylphenol, 2,4-xylenol, p-ethylphenol or a mixture of p-ethylphenol and 2,3-xylenol, 2,4,6-trimethylphenol, 2,4-methylethylphenol, 2,3,6-trimethylphenol, p-isopropylphenol or a mixture of p-isopropylphenol and p-propylphenol; the residue is returned to the first step to participate in the synthesis of the next batch of phenolic resin.

2. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin 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 ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The second phenolic component is selected from at least one of 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, and m-p-propylphenol / isopropylphenol; 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.

4. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in 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; a portion of the second phenolic component accounts for 0 to 100% of its total mass.

5. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The alkaline catalyst is an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, or ammonia; the aldehyde is an aqueous solution of formaldehyde, paraformaldehyde, or acetaldehyde; the amount of aldehyde is 0.6 to 6 times the total molar amount of phenol, meta-alkylphenol, meta-para-alkylphenol, meta-ortho-alkylphenol, meta-meta-alkylphenol, and meta-meta-ortho-alkylphenol in the phenolic material; the mass of the portion of aldehyde is 0 to 100% of the total mass of aldehydes fed.

6. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The catalyst 2 is an acidic catalyst selected from oxalic acid, formic acid, phosphoric acid, or hydrochloric acid; or a basic catalyst selected from an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, or ammonia.

7. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The non-water-soluble solvent is an aromatic hydrocarbon, chloroalkanes, ethers, or esters, preferably toluene or methyl isobutyl ether; the amount of solvent used is 0.5 to 2 times the mass of the phenolic material.

8. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The efficient vacuum distillation conditions in the second step are: pressure -0.07 to -0.1 MPa, reflux ratio 5 to 50, and number of trays 100 to 300.

9. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The method can also be used to prepare phenolic resin for rock wool or sulfonated phenolic resin as a high-temperature filtration agent; wherein the preparation of phenolic resin for rock wool further includes the steps of adding boric acid, urea and water; and the preparation of sulfonated phenolic resin further includes the step of sulfonation using sodium bisulfite and sodium sulfite.

10. The method for synthesizing ortho- and para-alkylphenols as a byproduct of phenolic resin according to claim 1, characterized in that, The method further includes a step of reacting unreacted meta-phenol / meta-para-phenol / meta-ortho-phenol in the distilled water with formaldehyde to reduce the impurity content in the ortho-para-phenol product.

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