Method for producing bisphenol compounds

Abstract

To provide a method for producing a bisphenol compound which can improve the conversion rate and purity of a bisphenol compound, reduce the solvent used in the condensation reaction and is easy to industrialize.SOLUTION: There is provided a method for producing a bisphenol compound which comprises: a condensation step of subjecting an aldehyde compound having 2 to 10 carbon atoms and a specific phenol to a condensation reaction in an equivalent ratio [the aldehyde compound A / the compound B=0.15 to 0.35] to obtain a reaction mixture; an extraction step of neutralizing the reaction compound with a basic compound, followed by extracting with an extraction solvent to obtain a crude product; and a recrystallization step of to recrystallizing the crude product with a recrystallization solvent containing 35 mass% or more of methanol, wherein in the condensation step, the condensation reaction is carried out under the condition where the content of a reaction solvent is 5 mass% or less based on the total content of the aldehyde compound and the phenol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a bisphenol compound. [Background technology]

[0002] Bisphenol compounds are useful compounds that are widely used as raw materials for thermoplastic resins such as polycarbonate resins and acrylate resins, and for thermosetting resins such as epoxy resins, polyimide resins, and phenolic resins, as well as additives for curing agents, antioxidants, color developers, bactericides, fungicides, and flame retardants. Therefore, various studies have been conducted on methods for producing bisphenol compounds.

[0003] For example, Patent Document 1 discloses a method for producing a bisphenol compound by condensing a specific monophenol compound with a ketone compound or an aldehyde compound in the presence of an acidic catalyst, followed by purification by preparative thin-layer chromatography or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-189526 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method described in Patent Document 1 has problems such as a low conversion rate of the bisphenol compound and a low purity of the bisphenol compound. Furthermore, the method of purifying bisphenol compounds by preparative thin-layer chromatography described in Patent Document 1 has also had the problem that it is difficult to scale up to an industrial scale. Furthermore, the method described in Patent Document 1 requires the use of a sufficient amount of solvent during the condensation reaction, and therefore there is room for improvement in terms of cost.

[0006] Therefore, the present invention provides a method for producing a bisphenol compound, which can improve the conversion rate and purity of the bisphenol compound, reduce the amount of solvent used in the condensation reaction, and is easy to commercialize. [Means for solving the problem]

[0007] That is, the present invention is a method for producing a bisphenol compound represented by the following general formula (1), which comprises a condensation step of subjecting an aldehyde compound A having 2 to 10 carbon atoms and a compound B represented by the following general formula (2) to a condensation reaction in an equivalent ratio [aldehyde compound A / compound B=0.15 to 0.35] to obtain a reaction mixture; an extraction step of neutralizing the reaction mixture with a basic compound and extracting it with an extraction solvent to obtain a crude product; and a recrystallization step of recrystallizing the crude product in a recrystallization solvent containing 35 mass% or more of methanol, wherein the condensation step is performed under conditions where the content of the reaction solvent is 5 mass% or less based on the total content of the aldehyde compound A and the compound B.

[0008] [ka] [ka] (In general formula (1), X 1 R is a divalent linking group derived from hydrocarbons with 2 to 10 carbon atoms, 1 R is a hydrocarbon group having 10 to 18 carbon atoms, and in general formula (2), 1 (A hydrocarbon group has 10 to 18 carbon atoms.)

[0009] In the method for producing bisphenol compounds of the present invention, it is preferable to use an acid as a catalyst in the condensation step. Furthermore, the above acid is preferably a sulfonic acid. Furthermore, the above-mentioned recrystallization solvent preferably contains 65% by mass or more of methanol. Moreover, the compound B is preferably derived from a hydrogenated cardanol. The aldehyde compound A is preferably an aldehyde compound having 3 to 7 carbon atoms. In addition, in the general formula (1), R 1 is X 1 In the general formula (1), R 1 may be in the meta position relative to O, and in the general formula (1), O is X 1 It may be in the ortho position relative to [Effects of the Invention]

[0010] The present invention can provide a method for producing a bisphenol compound that can improve the conversion rate and purity of the bisphenol compound, reduce the amount of solvent used in the condensation reaction, and is easy to commercialize. [Brief explanation of the drawings]

[0011] [Figure 1] Figure 1 shows the infrared absorption spectrum of 3-pentadecylphenol as a sample. [Figure 2] FIG. 2 is an infrared absorption spectrum obtained by using the compound obtained in Example 1 as a sample. [Figure 3] FIG. 3 is an infrared absorption spectrum obtained by using the compound obtained in Example 6 as a sample. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention is a method for producing a bisphenol compound represented by the following general formula (1), which comprises a condensation step of subjecting an aldehyde compound A having 2 to 10 carbon atoms and a compound B represented by the following general formula (2) to a condensation reaction in an equivalent ratio [aldehyde compound A / compound B=0.15 to 0.35] to obtain a reaction mixture; an extraction step of neutralizing the reaction mixture with a basic compound and extracting the mixture with an extraction solvent to obtain a crude product; and a recrystallization step of recrystallizing the crude product in a recrystallization solvent containing 35% by mass or more of methanol, wherein the condensation step is carried out under conditions where the content of the reaction solvent is 5% by mass or less based on the total content of the aldehyde compound A and the compound B.

[0013] [ka] [ka] (In general formula (1), X 1 R is a divalent linking group derived from hydrocarbons with 2 to 10 carbon atoms, 1 R is a hydrocarbon group having 10 to 18 carbon atoms, and in general formula (2), 1 (A hydrocarbon group has 10 to 18 carbon atoms.)

[0014] Typically, in a system for synthesizing a bisphenol compound having a hydrocarbon group (long-chain alkyl group) with 10 to 18 carbon atoms, the formula weight of the long-chain alkyl group is large, so the entire system is rich in hydrocarbons and is considered to have low polarity. Therefore, it is unlikely that a polar catalyst will dissolve or act in the system, and a solvent is usually required. Furthermore, even if the catalyst is dissolved in the system, it is thought that the steric hindrance of the long-chain alkyl group makes it difficult for the catalyst molecules to approach the reaction site, and this also makes it difficult for the reaction to be promoted. However, the present inventors have found that the condensation reaction of a bisphenol compound having a hydrocarbon group (long-chain alkyl group) having 10 to 18 carbon atoms can be promoted by the use of a catalyst even in a solvent-free system for synthesizing the compound. They have also found that the conversion rate and purity of the bisphenol compound can be improved by recrystallizing the resulting crude product of the bisphenol compound using a recrystallization solvent containing a predetermined amount of methanol, and that the process can be easily commercialized because purification can be performed without using preparative thin-layer chromatography, thereby completing the present invention. However, the present invention does not have to be interpreted as being limited to the above mechanism.

[0015] (condensation process) In the method for producing a bisphenol compound of the present invention, the condensation step is a step of subjecting an aldehyde compound A having 2 to 10 carbon atoms and a compound B represented by the following general formula (2) to a condensation reaction in an equivalent ratio [aldehyde compound A / compound B=0.15 to 0.35] to obtain a reaction mixture.

[0016] [ka] (In general formula (2), R 1 (A hydrocarbon group has 10 to 18 carbon atoms.)

[0017] Examples of the aldehyde compound A having 2 to 10 carbon atoms include acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, pentylaldehyde, hexylaldehyde, heptylaldehyde, octylaldehyde, cyclohexanecarboxaldehyde, benzaldehyde, p-tolualdehyde, cuminaldehyde, and 2,4-dimethylbenzaldehyde. The above aldehyde compounds may be linear, branched, or cyclic, as long as they have 2 to 10 carbon atoms. Among these, from the viewpoint of miscibility and reactivity with compound B, an aldehyde compound having 3 to 7 carbon atoms is preferred, and propionaldehyde is more preferred. The aldehyde compound A may be used alone or in combination of two or more types.

[0018] The compound B represented by the general formula (2) is a hydrocarbon group R having 10 to 18 carbon atoms. 1 It has. R 1 As the carbon number, it may be a straight chain or a branched chain, but from the viewpoint of availability, R 1 Preferably, the number of carbon atoms is 15. The compound B represented by the general formula (2) may be used alone or in combination of two or more types.

[0019] In the above general formula (2), R 1 may be in the para position relative to O, and in the general formula (2), R 1 may be in the meta position relative to O, and in the general formula (2), R 1 may be ortho-positioned relative to O, but from the viewpoint of availability, R 1 is preferably in the meta position relative to O.

[0020] Examples of compound B represented by the general formula (2) above include alkylphenols such as 3-octylphenol, 3-nonylphenol, 3-decylphenol, 3-dodecylphenol, 3-pentadecylphenol, 3-hexadecylphenol, 3-octadecylphenol, and 3-nonadecylphenol. Among these, 3-pentadecylphenol, which is obtained by hydrogenating an alkyl-substituted monophenol derived from cardanol, is preferred. The cardanol is a component derived from cashew nut shell liquid, and allows for the effective use of cashew nut shells that have been treated as waste.

[0021] The equivalent ratio of the aldehyde compound A to the compound B represented by the general formula (2) is [aldehyde compound A / compound B=0.15 to 0.35]. By carrying out the condensation reaction at such an equivalent ratio, the conversion rate and purity of the resulting bisphenol compound can be improved. The equivalent ratio of the aldehyde compound A to the compound B represented by the general formula (2) is preferably [aldehyde compound A / compound B=0.20 to 0.35], and more preferably [aldehyde compound A / compound B=0.20 to 0.30]. The above-mentioned equivalent ratio means the ratio of the molar equivalent of the aldehyde compound A to the molar equivalent of the compound B.

[0022] In the condensation step, an acid is preferably used as a catalyst.

[0023] Preferred examples of the acid used as the catalyst include organic acid catalysts such as toluenesulfonic acid, xylenesulfonic acid, and oxalic acid; inorganic acid catalysts such as hydrochloric acid and sulfuric acid; and heteropolyacids such as tungstophosphoric acid, silicotungstic acid, phosphomolybdic acid, sodium phosphomolybdate, tungstophosphomolybdic acid, and phosphovanadomolybdic acid. The above catalysts may be used alone or in combination of two or more kinds.

[0024] The acid used as the catalyst is preferably a sulfonic acid, more preferably p-toluenesulfonic acid, from the viewpoints that no reaction solvent is required and that it is easily available.

[0025] The amount of the catalyst used is preferably 0.001 to 1 mole, and more preferably 0.01 to 0.05 mole, per mole of the compound represented by the general formula (2).

[0026] In the condensation step, the condensation reaction is carried out under conditions in which the content of the reaction solvent is 5% by mass or less based on the total content of the aldehyde compound A and the compound B. The content of the reaction solvent is preferably 2% by mass or less, more preferably 1% by mass or less, based on the total content of the aldehyde compound A and the compound B. The reaction solvent is a solvent that is neither the aldehyde compound A nor the compound B, nor the bisphenol compound represented by the general formula (1).

[0027] When the reaction solvent is used, examples of the reaction solvent include alcohols such as methanol, ethanol, and isopropyl alcohol; esters such as ethyl acetate; aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as toluene and xylene; and other solvents such as acetonitrile, dimethylformamide, dimethylacetamide, chloroform, methylene chloride, carbon tetrachloride, tetrahydrofuran, and dimethyl sulfoxide. The above reaction solvents may be used alone or in combination of two or more kinds.

[0028] The reaction temperature for the condensation reaction is preferably 10 to 150°C, more preferably 30 to 130°C, and even more preferably 50 to 120°C. The reaction pressure for the condensation reaction is not particularly limited, and may be increased, normal pressure, or reduced pressure, but it is preferable to carry out the condensation reaction under normal pressure.

[0029] The reaction time for the condensation reaction is preferably 0.5 to 20 hours, but is not limited to this because reactivity differs depending on the type of compound used in the condensation reaction.

[0030] The apparatus used in the condensation step is not particularly limited, and for example, a known reflux apparatus can be used.

[0031] (extraction process) In the method for producing a bisphenol compound of the present invention, the extraction step is a step in which the reaction mixture is neutralized with a basic compound and extracted with an extraction solvent to obtain a crude product.

[0032] The extraction step is carried out, for example, in the following manner. First, the reaction mixture is cooled to room temperature, and then an extracting solvent and a basic compound are added to the reaction mixture, followed by shaking and then allowing to stand, and the aqueous phase is removed to obtain an organic phase. The obtained organic phase is washed with water, and the organic solvent is removed by heating or vacuum distillation of the organic phase obtained after washing, and the organic solvent is then dried to obtain a crude product.

[0033] The basic compound is not particularly limited, but preferred examples include metal hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate and potassium carbonate; phosphates such as sodium phosphate, sodium hydrogen phosphate, and pentasodium tripolyphosphate; ion exchange resins; basic solids such as alumina; and ammonia. In this case, it is preferable to gradually add the basic compound dropwise in the form of an aqueous solution in order to disperse the basic compound uniformly. The basic compounds may be used alone or in combination of two or more.

[0034] The extraction solvent is not particularly limited, but examples thereof include hexane, heptane, octane, methylcyclohexane, ethylcyclohexane, toluene, ethylbenzene, ethyl acetate, diethyl ether, chloroform, and methylene chloride. Among these, hexane is preferred from the viewpoint of its ability to dissolve bisphenol compounds and ease of distillation.

[0035] The method for carrying out the extraction step is not particularly limited, and any known extraction method can be used.

[0036] (Recrystallization process) In the method for producing a bisphenol compound of the present invention, the recrystallization step is a step in which the crude product is recrystallized in a recrystallization solvent containing 35% by mass or more of methanol.

[0037] The recrystallization solvent contains 35% by mass or more of methanol. Methanol has low solubility for the bisphenol compound of the general formula (1) and high solubility for the bisphenol compound of the general formula (2). Therefore, by using such a recrystallization solvent, the conversion rate and purity of the bisphenol compound of the general formula (1) can be improved. Furthermore, in the method for producing a bisphenol compound of the present invention, purification is performed without using preparative thin-layer chromatography, making it easy to commercialize. The recrystallization solvent preferably contains 50% by mass or more of methanol, more preferably 65% ​​by mass or more, even more preferably 85% by mass or more, and particularly preferably 95% by mass or more, and most preferably the recrystallization solvent consists solely of methanol.

[0038] Examples of the recrystallization solvent other than methanol include ethanol and water.

[0039] The amount of the recrystallization solvent used is, for example, preferably 50 to 5000 mass %, more preferably 100 to 1000 mass %, and even more preferably 150 to 500 mass %, relative to the mass (100 mass %) of the crude product.

[0040] In the recrystallization step, the crude product is dissolved in the recrystallization solvent heated to 55 to 65°C, and then the solution is preferably cooled to 0 to 20°C and allowed to stand, and particularly preferably cooled to 0 to 10°C and allowed to stand. By heating the crude product within the above temperature range, the solubility of the compound of general formula (1) in the recrystallization solvent can be improved, and the conversion rate of the compound of general formula (1) can be suitably improved. Furthermore, by cooling at such a temperature, it is possible to suitably promote the recrystallization of the bisphenol compound represented by the general formula (1) while suitably suppressing the recrystallization of the compound represented by the general formula (2). The standing time in the recrystallization step is not particularly limited, but is, for example, 1 hour.

[0041] (bisphenol compounds) According to the method for producing a bisphenol compound of the present invention, a bisphenol compound represented by the following general formula (1) can be produced.

[0042] [ka] (In general formula (1), X 1 R is a divalent linking group derived from hydrocarbons with 2 to 10 carbon atoms, 1 (A hydrocarbon group has 10 to 18 carbon atoms.)

[0043] In the above general formula (1), R 1 is X 1 In the general formula (1), R 1 may be in the meta position relative to O, and in the general formula (1), O is X 1 It may be in the ortho position relative to

[0044] The fact that the bisphenol compound represented by the above general formula (1) could be produced is 1 This can be confirmed by H NMR, infrared spectroscopy, etc. 1 For 1 H NMR, a product name "ECX300" manufactured by JEOL Ltd. can be used. For infrared spectroscopy, a product named "Nicolet iN10MX" manufactured by Thremo Fisher Scientific or the like can be used. In the infrared spectroscopy, the infrared absorption spectrum of the compound B represented by the general formula (2) used in the condensation step as a sample was compared with the infrared absorption spectrum of the compound obtained by the method for producing a bisphenol compound of the present invention as a sample, and the 1585 cm peak derived from the aromatic skeleton of the compound B represented by the general formula (2) was detected. -1 Nearby and 786cm -1 By checking the decrease in absorbance in the vicinity, it can be confirmed that the bisphenol compound represented by the above general formula (1) has been obtained.

[0045] The bisphenol compound represented by the general formula (1) produced by the method for producing a bisphenol compound of the present invention has a high conversion rate and a high purity. Specifically, in the method for producing a bisphenol compound of the present invention, the conversion rate of the bisphenol compound represented by the general formula (1) can be set to 25% or more and the Gardner color scale can be set to 17 or less. Furthermore, in the method for producing a bisphenol compound of the present invention, purification is carried out without using preparative thin-layer chromatography, and therefore industrialization is easy.

[0046] Here, the conversion rate can be calculated from the molar equivalent of the obtained bisphenol compound represented by the general formula (1) relative to the molar equivalent of the compound B represented by the general formula (2) used in the condensation step. Specifically, taking into consideration that two compounds B represented by the general formula (2) are required to obtain one bisphenol compound represented by the general formula (1), the amount can be calculated using the following formula. Conversion rate = (molar equivalent of the obtained bisphenol compound represented by general formula (1) × 2) / (molar equivalent of the compound B represented by general formula (2) used in the condensation step)

[0047] In the method for producing a bisphenol compound of the present invention, the conversion rate of the bisphenol compound represented by the general formula (1) can be set to 27% or more, 30% or more, 33% or more, or 35% or more.

[0048] The Gardner color number is measured based on ASTM-D154 (Standard Guide for Testing Varnishes). Specifically, 0.2 g of the obtained bisphenol compound represented by the general formula (1) was diluted with 0.1 ml of acetone to prepare a sample, which was then set in a "DAYLITE COMPARATOR ILLUMINATOR" manufactured by ORBECO ANLYTICAL SYSTEMS, and the color was compared with a color scale based on the 1933 GARDNER COLOR SCALE. The Gardner color number that most closely resembled the sample was determined as the Gardner color number.

[0049] In the bisphenol compound represented by the general formula (1) above, the smaller the Gardner color index, the higher the purity, and a value of 17 or less can be evaluated as having sufficient purity (few impurities). On the other hand, if the Gardner color number is 18 or more, it means that the purity is not sufficient. In conventional methods for producing bisphenol compounds represented by the above general formula (1), the Gardner color scale was 18 or more, but in the method for producing bisphenol compounds of the present invention, the Gardner color scale can be reduced to 17 or less. There is a clear difference in appearance between Gardner color numbers 17 and 18.

[0050] In the method for producing a bisphenol compound of the present invention, the Gardner color number of the bisphenol compound represented by the general formula (1) can be adjusted to 16 or less, 15 or less, 14 or less, or 13 or less. [Example]

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0052] Example 1 In a flask equipped with a stirrer, a reflux condenser, and a stirring device, 100 parts by mass of a cardanol hydrogenation product (3-pentadecylphenol) was weighed out while purging with nitrogen, and 1.6 parts by mass of p-toluenesulfonic acid and 6 parts by mass of propionaldehyde were added. Thereafter, the reaction solution was heated to 100°C and stirred under reflux for 3 hours to obtain a reaction mixture (condensation step). The reaction temperature was then returned to room temperature, and the resulting reaction mixture was neutralized with aqueous sodium hydroxide. The aqueous layer was extracted three times with hexane (extraction solvent), and the organic layer was dehydrated with sodium sulfate. The sodium sulfate was then removed by filtration, and the hexane was distilled off using an evaporator to obtain a crude product (extraction step). The obtained crude product was dissolved in methanol (recrystallization solvent, 300% by mass of the recrystallization solvent relative to 100% by mass of the crude product) at 60°C, then cooled to 5°C and allowed to stand for 1 hour to recrystallize, followed by filtration (recrystallization step). 1 is a linear C 15 H 31 and X 1 35 parts by mass of a linear bisphenol compound represented by C3H6 was obtained. The obtained bisphenol compound 1 H-NMR spectrum was measured. 1 H NMR (product name "ECX300", manufactured by JEOL Ltd., 300MHz, CDCl3): δ=7.17(d,2H),6.71(d,2H),6.58(s,2H),4.24(t,1H), 2.44(t,4H),2.13(quin,2H),1.50(quin,4H),1.25(m,48H),0.87(t+t,6H+3H) The infrared absorption spectrum of the 3-pentadecylphenol used in the condensation step as a sample and the infrared absorption spectrum of the compound obtained in Example 1 as a sample were measured using a Nicolet iN10MX (trade name) manufactured by Thremo Fisher Scientific. FIG. 1 is an infrared absorption spectrum obtained by using 3-pentadecylphenol as a sample, and FIG. 2 is an infrared absorption spectrum obtained by using the compound obtained in Example 1 as a sample. Comparing Figures 1 and 2, the peak at 1585 cm originating from the aromatic skeleton of 3-pentadecylphenol -1 and 786cm -1 A decrease in absorbance was confirmed. 1 The structure of the obtained bisphenol compound was identified from the results of H NMR and infrared absorption spectroscopy.

[0053] <Conversion rate> Conversion was calculated by the method described herein. That is, the conversion rate was calculated using the following formula based on the molar equivalent of the obtained bisphenol compound represented by the general formula (1) relative to the molar equivalent of 3-pentadecylphenol, which is compound B represented by the general formula (2) used in the condensation step. Conversion rate = (molar equivalent of the obtained bisphenol compound represented by general formula (1) × 2) / (molar equivalent of 3-pentadecylphenol, which is compound B represented by general formula (2) used in the condensation step) A calculated conversion rate of 25% or more was evaluated as passing.

[0054] <Gardner color number> The Gardner color number of the bisphenol compound was measured based on ASTM-D154 (Standard Guide for Testing Varnishes). Specifically, 0.2 g of the bisphenol compound represented by the general formula (1) was diluted with 0.1 ml of acetone to prepare a sample, which was then set in a "DAYLITE COMPARATOR ILLUMINATOR" manufactured by ORBECO ANLYTICAL SYSTEMS, Inc., and the color was compared with the color scale based on the 1933 GARDNER COLOR SCALE. The Gardner color number that most closely matched the sample was determined as the Gardner color number.

[0055] (Examples 2 to 5, Comparative Examples 1 to 6) The condensation step, extraction step, and recrystallization step were carried out in the same manner as in Example 1, except that the molar equivalent of aldehyde compound A and the recrystallization solvent were changed to those shown in Tables 1 and 2. In Examples 2 to 5 and Comparative Examples 1 to 4, R 1 is a linear C 15 H 31 and X 1 A linear bisphenol compound represented by C3H6 was obtained. In Comparative Examples 5 and 6, the bisphenol compound represented by the above general formula (1) could not be obtained. The conversion rate and Gardner color index of the bisphenol compounds obtained in each of the Examples and Comparative Examples were measured and calculated in the same manner as in Example 1, and are shown in Tables 1 and 2.

[0056] Example 6 The condensation step, extraction step, and recrystallization step were carried out in the same manner as in Example 1, except that the type of aldehyde compound A was changed to n-hexylaldehyde. In the above general formula (1), R 1 is a linear C 15 H 31 and X 1 is a straight chain CH 12 A bisphenol compound represented by the formula: The obtained bisphenol compound 1 H-NMR spectrum was measured. 1 H NMR (product name "ECX300", manufactured by JEOL Ltd., 300MHz, CDCl3): δ=7.17(d,2H),6.72(d,2H),6.57(s,2H),6.45(broad ,2H),4.33(t,1H),2.44(t,4H),2.09(quin,2H),1.50(quin,4H),1.25(m,56H),0.90(t+t,6H+3H) The infrared absorption spectrum of the 3-pentadecylphenol used in the condensation step as a sample and the infrared absorption spectrum of the sample obtained in Example 6 were measured using a Nicolet iN10MX (trade name) manufactured by Thremo Fisher Scientific. FIG. 1 is an infrared absorption spectrum obtained by using 3-pentadecylphenol as a sample, and FIG. 3 is an infrared absorption spectrum obtained by using the compound obtained in Example 6 as a sample. Comparing Figures 1 and 3, the peak at 1585 cm originating from the aromatic skeleton of 3-pentadecylphenol -1 and 786cm -1 A decrease in absorbance was confirmed. 1 The structure of the obtained bisphenol compound was identified from the results of H NMR and infrared absorption spectroscopy. The conversion rate and Gardner color number of the bisphenol compound obtained in Example 6 were measured and calculated in the same manner as in Example 1, and are shown in Table 1.

[0057] (Comparative Example 7) According to the method described in Example 2 of JP 2014-189526 A, R 1 is a linear C 15 H 31 and X 1 A linear bisphenol compound represented by C3H6 was obtained. The conversion rate of the bisphenol compound was measured and calculated in the same manner as in Example 1, and is shown in Table 2.

[0058] [Table 1]

[0059] [Table 2]

[0060] From the examples, in the method for producing a bisphenol compound of the present invention, it is clear that in the general formula (1) R 1 is a linear C 15 H 31 and X 1 is a straight chain C3H6 or C6H 12 It was possible to obtain a bisphenol compound represented by the formula (I) with a conversion rate of 25% or more and a Gardner color index of 17 or less. Furthermore, it is clear from the examples that the method for producing a bisphenol compound of the present invention is easy to commercialize because purification is carried out without using preparative thin-layer chromatography. On the other hand, in Comparative Examples 1 to 3 in which the equivalent of aldehyde relative to hydrogenated cardanol was not within the predetermined range, the Gardner color score was 18 or more, and the purity was insufficient. In Comparative Example 4, in which the specified recrystallization solvent was not used, the conversion rate decreased, and in Comparative Examples 5 and 6, a bisphenol compound could not be obtained. Furthermore, in Comparative Example 7, in which the reaction solvent was used in an amount of 5 mass % or more relative to the total content of the hydrogenated cardanol and the aldehyde compound, the conversion rate decreased. [Industrial Applicability]

[0061] The method for producing a bisphenol compound of the present invention can improve the conversion rate and purity of the bisphenol compound, reduce the amount of solvent used in the condensation reaction, and provide a method for producing a bisphenol compound that is easy to commercialize.

Claims

1. A method for producing a bisphenol compound represented by the following general formula (1): a condensation step of subjecting an aldehyde compound A having 2 to 10 carbon atoms and a compound B represented by the following general formula (2) to a condensation reaction in an equivalent ratio [aldehyde compound A / compound B=0.15 to 0.35] to obtain a reaction mixture; an extraction step of neutralizing the reaction mixture with a basic compound and extracting the mixture with an extraction solvent to obtain a crude product; a recrystallization step of recrystallizing the crude product in a recrystallization solvent containing 35% by mass or more of methanol, The condensation step is carried out under the conditions that the content of the reaction solvent is 5% by mass or less based on the total content of the aldehyde compound A and the compound B, and p-toluenesulfonic acid is used as a catalyst. A method for producing bisphenol compounds. 【Chemistry 1】 【Chemistry 2】 (In general formula (1), X １ is a divalent linking group having 2 to 10 carbon atoms derived from a hydrocarbon, and R １ is a hydrocarbon group having 10 to 18 carbon atoms, and in general formula (2), R １ is a hydrocarbon group having 10 to 18 carbon atoms.

2. 2. The method for producing a bisphenol compound according to claim 1, wherein the recrystallization solvent contains 65% by mass or more of methanol.

3. The method for producing a bisphenol compound according to claim 1 or 2, wherein the compound B is derived from a hydrogenated cardanol.

4. 4. The method for producing a bisphenol compound according to claim 1, wherein the aldehyde compound A is an aldehyde compound having 3 to 7 carbon atoms.

5. In the general formula (1), R １ is X １ The method for producing a bisphenol compound according to any one of claims 1 to 4, wherein

6. In the general formula (1), R １ The method for producing a bisphenol compound according to any one of claims 1 to 4, wherein

7. In the general formula (1), O represents X １ The method for producing a bisphenol compound according to any one of claims 1 to 4, wherein the hydroxyl group is at the ortho position relative to

Images