Catalyst for synthesizing bisphenol A

Abstract

The invention discloses a catalyst for synthesizing bisphenol A. The catalyst is prepared by the following steps: firstly, carrying out suspension free radical copolymerization reaction on polymerizable monomers styrene, divinylbenzene and glycidyl methacrylate to obtain epoxy group-containing resin; the preparation method comprises the following steps: reacting resin containing epoxy groups with a compound containing primary amine groups / secondary amine groups and sulfydryl groups, carrying out nucleophilic addition reaction on the primary amine groups or the secondary amine groups and the epoxy groups on the resin, and immobilizing the sulfydryl groups on the resin to obtain sulfydryl group resin; and reacting the sulfydryl-loaded resin with sulfuric acid to sulfonate the resin to obtain the covalent sulfydryl-loaded strong-acid cation exchange resin. The resin covalently loaded with the sulfydryl and the sulfonic acid group is used as a catalyst for condensation reaction of phenol and ketone, and is particularly used as a catalyst for preparing bisphenol A by condensation of phenol and acetone.

Description

Technical Field

[0001] The invention relates to a catalyst for synthesizing bisphenol A, in particular to a strongly acidic cation exchange resin containing a mercapto group and a preparation method and application thereof, belonging to the technical field of catalyst synthesis. Background Art

[0002] Bisphenol A is an important chemical raw material. As a raw material for producing epoxy resins, polycarbonates, etc., it is in great demand. The production process of bisphenol A is to form phenol and acetone by condensation reaction under acid catalysis. Strong acid catalysts such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, and strong acid cation exchange resin can catalyze the condensation reaction of phenol and acetone. At present, strong acid cation exchange resin heterogeneous catalysts are mostly used in industry. The advantages of heterogeneous catalysts include easy separation of catalyst and product and reusability.

[0003] The side reaction in the condensation process of phenol and acetone catalyzed by strongly acidic cation exchange resin is to generate polyphenol compounds with larger molecular weight. The formation of polyphenol compounds not only consumes raw materials, but also gathers in the resin interior, and the catalytic activity of the resin is gradually reduced. In order to solve this problem, a sulfhydryl compound is introduced in the reaction system to stop the formation of polyphenol compounds, which is called a catalytic reaction promoter. Promoting groups such as ethyl mercaptan are directly added to the mixed solution of acetone and phenol to carry out catalytic condensation reaction, which can reduce the formation of polyphenol compounds and delay the reduction of the catalytic activity of strongly acidic cation exchange resin. However, the promoter pollutes the final product, increases the cost of product purification, and the stink of mercaptan compounds is extremely large.

[0004] In order to solve these problems, the method currently adopted is to immobilize the compound containing amino or amido and sulfydryl (such as cysteamine) on the strongly acidic cation exchange resin as catalyst through ion action (US3394089; US4820740), 15-20% of the sulfonic acid groups on the resin are combined with the compound containing amino or amido and sulfydryl and lose the strong acidity, and the remaining sulfonic acid groups play a catalytic role. Because the reaction of the amino or amido in the compound containing amino or amido and sulfydryl with the sulfonic acid group on the resin is very fast, the compound containing amino or amido and sulfydryl should all be concentrated on the surface of the resin, and the center of the resin may be very few, unevenly distributed, so its effect of promoting catalysis and reducing side reactions is not good. In addition, the compound containing amino or amido and sulfydryl will still fall off gradually during the catalytic reaction, which not only gradually reduces the activity of the catalyst, but also pollutes the product bisphenol A with the promotor that falls off.

[0005] In order to solve this problem, the US patent (US3049568) uses a strong acid cation exchange resin to react with mercaptoethanol so that part of the sulfonic acid groups on the resin and the hydroxyl groups of mercaptoethanol form sulfonates and the mercapto groups are immobilized on the resin through covalent bonds. The disadvantage of this method is that the sulfonates are unstable and will fall off during use. In addition, subsequent studies (RA Reinicker, BC Gates, AI ChE J. 1974, 20, 933; K. Jerabek, J. Odnoha, K. Setinek, Appl. Catal. 1987, 52, 1272) show that this covalent immobilization of mercapto groups does not improve the catalytic activity of the resin in catalyzing the synthesis of bisphenol A. The scholars of this study believe that the formation of sulfonates described in the patent is not correct, but rather a dehydration reaction of mercaptoethanol occurs.

[0006] Another US patent (US3172916) adopts a method in which dry Dowex-50-WX4 (sulfonated styrene-divinylbenzene ion exchange resin) is reacted with chlorosulfonic acid using dichloroethane as a solvent to introduce sulfonyl chloride groups on the resin. The resin is washed with dichloroethane several times and then suspended in 37% hydrochloric acid, and then granular tin is added to react to reduce the sulfonyl chloride groups on the resin to thiol groups. The preparation process of this catalyst is complicated, polluting, and costly. Summary of the invention

[0007] The technical problem to be solved by the present invention is to solve the disadvantage of the prior art that sulfhydryl groups are immobilized on strongly acidic cation exchange resins as catalysts for the reaction of phenol and acetone to generate bisphenol A, and to provide a preparation method of a strongly acidic cation exchange resin on which sulfhydryl compounds are covalently immobilized and an application of the resin as a catalyst for the reaction of phenol and acetone to generate bisphenol A. The present invention has the advantages of high catalyst acetone conversion rate, long service life, and the like.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] The present invention first provides a method for preparing a catalyst for synthesizing bisphenol A, wherein the catalyst is a resin covalently loaded with thiol groups and sulfonic acid groups, comprising the following steps:

[0010] (1) firstly, polymerizable monomers styrene, divinylbenzene and glycidyl methacrylate are subjected to suspended radical copolymerization to obtain an epoxy group-containing resin;

[0011] (2) reacting the epoxy group-containing resin obtained in step (1) with a compound containing a primary / secondary amine group and a thiol group, wherein the primary / secondary amine group reacts with the epoxy group on the resin by a nucleophilic addition reaction, so that the thiol group is fixed on the resin, thereby obtaining a thiol-containing resin;

[0012] (3) reacting the thiol-loaded resin obtained in step (2) with sulfuric acid to sulfonate the resin, thereby obtaining a strongly acidic cation exchange resin covalently loaded with thiol groups, wherein the reaction formula is shown in Formula I:

[0013]

[0014] Where: R1=H, R2=(CH2) n SH; or R1=R2=(CH2) n SH; n=2, 3, 4, 5 or 6.

[0015] In the above technical scheme, in step (1), the epoxy-containing resin prepared by copolymerization of styrene, divinylbenzene and glycidyl methacrylate is a gel-type resin, and no porogen is added during the copolymerization; or it is a macroporous resin, and a porogen is added during the copolymerization. The preparation method of the gel-type resin and the macroporous resin in the present invention can adopt any method conventionally used in the art, and there is no special restriction on the preparation method of the gel-type resin and the macroporous resin and the pore structure parameters of the resin: for example, the porogen can be any organic matter that does not participate in free radical polymerization, is insoluble in water, or has a low solubility in water, including alkanes, aromatic hydrocarbons, alcohols, carboxylic acids, ketones, esters, etc.

[0016] In the above technical scheme, in step (1), the epoxy group-containing resin is preferably prepared by the following preparation method: dissolving sodium chloride and polyvinyl alcohol in water to prepare an aqueous phase, then uniformly mixing divinylbenzene, styrene, glycidyl methacrylate and other polymerizable monomers with benzoyl peroxide to form an organic phase, and if a macroporous resin is required, adding a porogen in the preparation of the organic phase; then adding the organic phase to the aqueous phase, stirring, adjusting the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heating to 40-85°C for reaction for 2-10h, and then heating to 90-100°C for reaction for 2-10h. Cooling, filtering, and fully washing the obtained resin with hot water, drying, and sieving to obtain the epoxy group-containing resin.

[0017] In the above technical scheme, the mass concentration of sodium chloride in the aqueous phase is 0.1-20%, preferably 5%, and the mass concentration of polyvinyl alcohol is 0.1-5%, preferably 0.5%; the mass ratio of divinylbenzene, styrene, and glycidyl methacrylate in the polymerizable monomer is (0.1-20): (0.1-100): (0.1-50); the mass of the benzoyl peroxide is 0.1-5% of the total weight of the polymerizable monomer, the mass of the porogen is 0.1-100% of the total weight of the polymerizable monomer, and the porogen is any one of liquid paraffin, isooctyl alcohol or No. 200 gasoline; the mass ratio of the organic phase (or the total weight of the polymerizable monomer) to the aqueous phase is (0.1-200): (0.1-1000).

[0018] In the above technical solution, the glycidyl methacrylate accounts for 2-20% of the total weight of all polymerizable monomers for preparing the epoxy-containing resin.

[0019] In the above technical solution, the cross-linking degree of the gel-type resin is 1-7%; the cross-linking degree of the macroporous resin is 5-20%.

[0020] In the above technical solution, in step (2), the compound containing primary / secondary amine and thiol has a general chemical structure as shown in Formula II:

[0021]

[0022] Where: R1=H, R2=(CH2) n SH; or R1=R2=(CH2) n SH; n = 2, 3, 4, 5 or 6; preferably cysteamine H2NCH2CH2SH, wherein R1 = H, R2 = (CH2) n SH, n = 2, or preferably di(mercaptoethyl)amine, wherein R1 = R2 = (CH2) n SH, n=2.

[0023] In the above technical scheme, in step (2), the compound containing a primary / secondary amine group and a thiol group is preferably used in the form of its hydrochloride when participating in the reaction. The general formula of the hydrochloride of the compound containing a primary / secondary amine group and a thiol group is as shown in Formula III:

[0024]

[0025] Where: R1=H, R2=(CH2) n SH; or R1=R2=(CH2) n SH; n=2, 3, 4, 5 or 6; preferably cysteamine hydrochloride or bis(mercaptoethyl)amine hydrochloride.

[0026] In the above technical scheme, in step (2), the preparation method of the common strong acid cation exchange resin is to carry out suspension polymerization of styrene and divinylbenzene (if a porogen is added to prepare a macroporous resin), obtain so-called white balls, swell the dried white balls with ethylene dichloride and sulfonate with sulfuric acid; the preparation method of the strong acid cation exchange resin with immobilized thiol groups of the present invention is to first prepare a resin with immobilized thiol groups, wash and dry the resin with immobilized thiol groups, and then further carry out sulfonation according to the preparation method of the common strong acid cation exchange resin, or directly sulfonate the thiol groups without separation after immobilizing the thiol groups with the epoxy group-containing resin, i.e., the "one-pot method": the epoxy group-containing resin is reacted with a compound containing an amino group or a secondary amine group and a thiol group with ethylene dichloride as a solvent, and then sulfuric acid is directly added for sulfonation; the present invention is more inclined to adopt the "one-pot method" for preparation, because the "one-pot method" is simpler, more environmentally friendly, and has a low preparation cost. The invention adopts a "one-pot method" to prepare a strongly acidic cation exchange resin, wherein the mass ratio of the epoxy group-containing resin to the compound containing primary / secondary amine groups and mercapto groups is (0.1-100): (0.1-20); when a nucleophilic addition reaction is carried out, solvents dichloroethane and triethylamine need to be added into the system, the amount of dichloroethane is 0.1-1000% of the mass of the resin, and the amount of triethylamine is 0.1-100% of the mass of the resin; when a nucleophilic addition reaction is carried out, the reaction conditions are: a reaction temperature of 25-100°C and a reaction time of 1-10h.

[0027] In the above technical solution, in step (3), the mass ratio of the thiol-loaded resin to sulfuric acid is (0.1-100):

[0028] (100-1000), the sulfuric acid is sulfuric acid with a mass concentration of 80-98%; the sulfonation reaction, the reaction conditions are: stirring and heating to 60-70°C and reacting at this temperature for 1-10h, then heating to 75-80°C and reacting at this temperature for 1-10h, continuing to heat to 85-120°C in 1-10h, reacting at this temperature for 1-10h and then cooling to room temperature; after the sulfonation reaction is completed, dilute sulfuric acid with a mass concentration of 0.1-90% is added dropwise to the system to reduce the sulfuric acid specific gravity of the mother liquor in the bottle to 1.0 according to the sulfuric acid specific gravity from high to low, filtering, and washing with deionized water to neutrality to obtain the finished resin.

[0029] The present invention also provides a resin covalently loaded with thiol and sulfonic acid groups obtained by the above preparation method, and the general chemical structure is represented by Formula IV:

[0030]

[0031] Where R1=H、R2=(CH2) n SH, or R1=R2=(CH2) nSH; n=2, 3, 4, 5 or 6.

[0032] The present invention also provides an application of the covalently loaded mercapto and sulfonic acid resin as a catalyst for catalyzing the condensation reaction of phenol and ketone, preferably as a catalyst for condensing phenol and acetone to prepare bisphenol A.

[0033] Compared with the existing technology, it has the following characteristics:

[0034] (1) High acetone conversion rate.

[0035] (2) The catalyst has a long service life. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] A catalyst for synthesizing bisphenol A, which is a resin covalently loaded with mercapto groups and sulfonic acid groups, is prepared by the following preparation method:

[0039] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) as the aqueous phase to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser, and mix 2.5 g of divinylbenzene (content 80%), 89.5 g of styrene, 8 g of glycidyl methacrylate and 0.5 g of benzoyl peroxide as the organic phase; add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the obtained resin with hot water, dry it, and sieve to obtain a 40-26 mesh epoxy-containing resin, which is a gel-type resin with a crosslinking degree of 2%.

[0040] (2) Under nitrogen protection, 20 g of the resin obtained in step (1), 120 mL of dichloroethane, 5.84 g of di(mercaptoethyl)amine hydrochloride and 3.40 g of triethylamine were added to a 500 mL three-necked flask, heated to 80° C. for reaction for 6 h with stirring, and cooled to room temperature.

[0041] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70° C. for reaction for 1 h under stirring, then heat to 80° C. for reaction for 6 h, heat to 110° C. for 4 h, cool to room temperature after reaction for 4 h, and dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1% from high to low, reduce the specific gravity of sulfuric acid in the mother liquor in the flask to 1.0 in sequence, filter, and wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-01.

[0042] Example 2

[0043] A catalyst for synthesizing bisphenol A, which is a resin covalently loaded with mercapto groups and sulfonic acid groups, is prepared by the following preparation method:

[0044] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) as the aqueous phase to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser, and mix 5 g of divinylbenzene (content 80%), 80 g of styrene, 15 g of glycidyl methacrylate and 0.5 g of benzoyl peroxide as the organic phase; add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the obtained resin with hot water, dry it, and sieve it to obtain a 40-26 mesh epoxy-containing resin, which is a gel-type resin with a crosslinking degree of 4%.

[0045] (2) Under nitrogen protection, 20 g of the resin obtained in step (1), 100 mL of dichloroethane, 7.16 g of cysteamine hydrochloride and 6.38 g of triethylamine were added to a 500 mL three-necked flask, heated to 80° C. with stirring for 6 h, and cooled to room temperature.

[0046] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70° C. for reaction for 1 h under stirring, then heat to 80° C. for reaction for 6 h, heat to 110° C. for 4 h, cool to room temperature after reaction for 4 h, dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1%, reduce the specific gravity of the mother liquor sulfuric acid in the flask to 1.0 in sequence, filter, and wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-02.

[0047] Example 3

[0048] A catalyst for synthesizing bisphenol A, which is a resin covalently loaded with mercapto groups and sulfonic acid groups, is prepared by the following preparation method:

[0049] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) as the aqueous phase to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser, and mix 7.5 g of divinylbenzene (content 80%), 80.5 g of styrene, 12 g of glycidyl methacrylate and 0.5 g of benzoyl peroxide as the organic phase; add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the obtained resin with hot water, dry it, and sieve it to obtain a 40-26 mesh epoxy-containing resin, which is a gel-type resin with a crosslinking degree of 6%.

[0050] (2) Under nitrogen protection, 20 g of the resin obtained in step (1), 100 mL of ethylene dichloride, 6.46 g of 3-mercaptopropylamine hydrochloride and 5.12 g of triethylamine were added to a 500 mL three-necked flask, heated to 80° C. with stirring for 6 h, and cooled to room temperature.

[0051] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70°C for reaction for 1 h under stirring, then heat to 80°C for reaction for 6 h, heat to 110°C for 4 h, cool to room temperature after reaction for 4 h, dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1%, reduce the specific gravity of the mother liquor sulfuric acid in the flask to 1.0 in sequence, filter, and wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-03.

[0052] Example 4

[0053] A catalyst for synthesizing bisphenol A, which is a resin covalently loaded with mercapto groups and sulfonic acid groups, is prepared by the following preparation method:

[0054] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser as the aqueous phase, and mix 7 g of divinylbenzene (content 80%), 58.8 g of styrene, 10.5 g of glycidyl methacrylate, 28 g of liquid paraffin and 0.35 g of benzoyl peroxide as the organic phase. Add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the resulting resin with hot water, dry, extract with No. 120 gasoline for 8 hours, dry, vacuum dry, and sieve to obtain a 40-26 mesh epoxy-containing resin, which is a macroporous resin with a crosslinking degree of 7.3%.

[0055] (2) Under nitrogen protection, 20 g of the resin obtained in step (1), 100 mL of dichloroethane, 7.16 g of cysteamine hydrochloride and 6.38 g of triethylamine were added to a 500 mL three-necked flask, heated to 80° C. with stirring for 6 h, and cooled to room temperature.

[0056] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70°C for reaction for 1 h under stirring, then heat to 80°C for reaction for 6 h, heat to 110°C for 4 h, cool to room temperature after reaction for 4 h, dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1%, reduce the specific gravity of the mother liquor sulfuric acid in the flask to 1.0 in sequence, filter, and then wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-04.

[0057] Example 5

[0058] A catalyst for synthesizing bisphenol A, which is a resin covalently loaded with mercapto groups and sulfonic acid groups, is prepared by the following preparation method:

[0059] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) as the aqueous phase to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser, and mix 8.75 g of divinylbenzene (content 80%), 57.05 g of styrene, 4.2 g of glycidyl methacrylate, 28 g of isooctyl alcohol and 0.35 g of benzoyl peroxide as the organic phase. Add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the resulting resin with hot water, dry, extract with acetone for 8 hours, dry, vacuum dry, and sieve to obtain a 40-26 mesh epoxy-containing resin, which is a macroporous resin with a crosslinking degree of 10%.

[0060] (2) Under nitrogen protection, 20 g of the resin obtained in step (1), 80 mL of ethylene dichloride, 4.38 g of di(mercaptoethyl)amine hydrochloride and 2.55 g of triethylamine were added to a 500 mL three-necked flask, heated to 80° C. with stirring for 6 h, and cooled to room temperature.

[0061] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70° C. for reaction for 1 h under stirring, then heat to 80° C. for reaction for 6 h, heat to 110° C. for 4 h, cool to room temperature after reaction for 4 h, dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1%, reduce the specific gravity of the mother liquor sulfuric acid in the flask to 1.0 in sequence, filter, and then wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-05.

[0062] Example 6

[0063] (1) Add 500 mL of an aqueous solution containing 5% sodium chloride and 0.5% polyvinyl alcohol (model 1788) as the aqueous phase to a 1000 mL three-necked flask equipped with a mechanical stirring device and a reflux condenser. Also, mix 10.5 g of divinylbenzene (content 80%), 57.4 g of styrene, 2.1 g of glycidyl methacrylate, 28 g of No. 200 gasoline and 0.35 g of benzoyl peroxide as the organic phase. Add the organic phase to the aqueous phase in the three-necked flask, start stirring, adjust the stirring speed so that the organic droplets are mainly concentrated in 30-60 mesh, heat to 80°C for reaction for 6 hours, and then heat to 90°C for reaction for 6 hours. Cool, filter, and wash the resulting resin with hot water, air dry, extract with acetone for 8 hours, air dry, vacuum dry, and sieve to obtain a 40-26 mesh epoxy-containing resin. The resin is a macroporous resin with a crosslinking degree of 12%.

[0064] (2) Under nitrogen protection, add 20 g of the resin obtained in step (1), 100 mL of dichloroethane, 2.19 g of di(mercaptoethyl)amine hydrochloride and 1.28 g of triethylamine into a 500 mL three-necked flask, heat to 80° C. and react for 6 h. Cool to room temperature.

[0065] (3) Add 200 mL of 93% sulfuric acid to the three-necked flask in step (2), heat to 70°C for reaction for 1 h under stirring, then heat to 80°C for reaction for 6 h, heat to 110°C for 4 h, cool to room temperature after reaction for 4 h, dropwise add dilute sulfuric acid with concentrations of 70%, 50%, 20%, and 1%, reduce the specific gravity of the mother liquor sulfuric acid in the flask to 1.0 in sequence, filter, and then wash with deionized water to neutrality to obtain a finished product of a resin covalently loaded with thiol and sulfonic acid groups, resin number: KRC-06.

[0066] Verification Example

[0067] Take 20 ml of the resin catalyst in Examples 1 to 6 respectively, place it in a 100 mL stainless steel reactor with an inner diameter of 20 mm, dehydrate it with a mixture of phenol and water (90 wt% phenol), repeat twice, and continuously dehydrate with pure phenol until the water content in the reactor effluent is less than 1 wt%, then pump phenol and acetone (prepared with a molar ratio of 8.7:1) at 80°C and 1.2 MPa, with an air velocity of 0.9 h-, run continuously for 1 month, and measure the average conversion rate of acetone. Detection instrument: Elite HPLC3100 detection, using a visible ultraviolet detector. The above experimental results are shown in Table 1.

[0068] Table 1 Acetone conversion rate of bisphenol A synthesis reaction

[0069]

[0070] It can be seen from Table 1 that the resin in the embodiment is used as a catalyst in the synthesis reaction of bisphenol A. The initial average conversion rate of acetone of KRC-01 to KRC-06 is above 89%, and the acetone conversion rate is high. After 30 days of reaction, the average conversion rate of acetone of KRC-01 to KRC-06 is above 74.8%, indicating that the resin catalyst has a long service life.

[0071] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a catalyst for synthesizing bisphenol A, wherein the catalyst is a resin covalently loaded with thiol and sulfonic acid groups, characterized in that: The following steps are involved: (1) firstly, polymerizable monomers styrene, divinylbenzene and glycidyl methacrylate are subjected to suspended radical copolymerization to obtain an epoxy group-containing resin; (2) reacting the epoxy group-containing resin obtained in step (1) with a compound containing a primary / secondary amine group and a thiol group, wherein the primary / secondary amine group reacts with the epoxy group on the resin by a nucleophilic addition reaction, so that the thiol group is fixed on the resin, thereby obtaining a thiol-containing resin; (3) reacting the thiol-loaded resin obtained in step (2) with sulfuric acid to sulfonate the resin, thereby obtaining a strongly acidic cation exchange resin covalently loaded with thiol groups, wherein the reaction formula is shown in Formula I: Where: R1=H, R2=(CH2) n SH; or R1=R2=(CH2) n SH; n=2, 3, 4, 5 or 6.

2. The preparation method according to claim 1, characterized in that: In step (1), the epoxy-containing resin prepared by copolymerization of styrene, divinylbenzene and glycidyl methacrylate is a gel-type resin, and no porogen is added during the copolymerization; or it is a macroporous resin, and a porogen is added during the copolymerization.

3. The preparation method according to claim 2, characterized in that: The epoxy group-containing resin is prepared by the following preparation method: sodium chloride and polyvinyl alcohol are dissolved in water to prepare a water phase, and then divinylbenzene, styrene, glycidyl methacrylate and other polymerizable monomers are mixed evenly with benzoyl peroxide to form an organic phase. If a macroporous resin is required, a porogen is added in the preparation of the organic phase; then the organic phase is added to the water phase, stirring is started, and the stirring speed is adjusted so that the organic droplets are mainly concentrated in 30-60 meshes, heated to 40-85°C for reaction for 2-10h, and then heated to 90-100°C for reaction for 2-10h. Cool, filter, and fully wash the obtained resin with hot water, dry it, and sieve it to obtain the epoxy group-containing resin.

4. The preparation method according to claim 2, characterized in that: The glycidyl methacrylate accounts for 2-20% of the total weight of all polymerizable monomers for preparing the epoxy-containing resin; the crosslinking degree of the gel-type resin is 1-7%; and the crosslinking degree of the macroporous resin is 5-20%.

5. The preparation method according to claim 1, characterized in that: In step (2), the compound containing primary / secondary amine and thiol has a general chemical structure as shown in Formula II: Where: R1=H, R2=(CH2) n SH; or R1=R2=(CH2) n SH; n=2, 3, 4, 5 or 6.

6. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of the epoxy group-containing resin to the compound containing primary / secondary amine groups and mercapto groups is (0.1-100):(0.1-20); when performing the nucleophilic addition reaction, solvents dichloroethane and triethylamine need to be added to the system, the amount of dichloroethane is 0.1-1000% of the mass of the resin, and the amount of triethylamine is 0.1-100% of the mass of the resin; when performing the nucleophilic addition reaction, the reaction conditions are: reaction temperature 25-100° C., reaction time 1-10 h.

7. The preparation method according to claim 1, characterized in that: In step (3), the mass ratio of the thiol-loaded resin to sulfuric acid is (0.1-100): (100-1000), and the sulfuric acid is sulfuric acid with a mass concentration of 80-98%; the reaction conditions of the sulfonation reaction are: stirring and heating to 60-70°C and reacting at this temperature for 1-10h, then heating to 75-80°C and reacting at this temperature for 1-10h, continuing to heat to 85-120°C in 1-10, reacting at this temperature for 1-10h and then cooling to room temperature; after the sulfonation reaction is completed, dilute sulfuric acid with a mass concentration of 0.1-90% is added dropwise to the system to reduce the sulfuric acid specific gravity of the mother liquor in the bottle from high to low to 1.0 according to the sulfuric acid specific gravity, filtering, and washing with deionized water to neutrality to obtain a finished resin.

8. A resin covalently loaded with thiol and sulfonic acid groups obtained by the preparation method according to any one of claims 1 to 7, characterized in that: The general formula of the chemical structure of the resin is represented by Formula IV: wherein R1=H, R2=(CH2)nSH, or R1=R2=(CH2)nSH; n=2, 3, 4, 5 or 6.

9. Use of the resin covalently loaded with mercapto groups and sulfonic acid groups as claimed in claim 8 as a catalyst for catalyzing the condensation reaction of phenol and ketone.

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