Process for making bisphenol A (BPA) in the presence of 2-methylbenzofuran

Abstract

The present invention relates to a process for making bisphenol A in the presence of 2-methylbenzofuran without poisoning a catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst, at least a portion of which is not covalently or ionically bonded to the ion exchange resin catalyst. Additionally, the present invention provides a process for making polycarbonate.

Description

[Technical field]

[0001] The present invention relates to a process for making bisphenol A and to a process for making polycarbonate. [Background technology]

[0002] Bisphenol A, or BPA, is an important monomer in the production of polycarbonate or epoxy resins. BPA is usually used in the form of para,para-BPA (2,2-bis(4-hydroxyphenol)propane; p,p-BPA), but ortho,ortho-BPA (o,o-BPA) and / or ortho,para-BPA (o,p-BPA) may also be formed in the production of BPA. When referring to BPA, it primarily refers to para,para-BPA, but also includes small amounts of ortho,ortho-BPA and / or ortho,para-BPA.

[0003] According to the current state of the art, BPA is produced by reacting phenol with acetone in the presence of an acid catalyst to obtain bisphenol. Previously, hydrochloric acid (HCl) was used in the commercial process of the condensation reaction. Currently, a heterogeneous continuous process for the production of BPA is used in the presence of an ion exchange resin catalyst, where the ion exchange resin comprises a crosslinked acid-functionalized polystyrene resin. The most important resin is polystyrene crosslinked by sulfonic acid groups. Divinylbenzene is most used as a crosslinking agent, as described in US Pat. No. 5,399,411; US ​​Pat. No. 5,499,523; US Pat. No. 5,599,633; and US Pat. No. 5,633,665, or in Non-Patent Document 1.

[0004] To achieve high selectivity, the reaction of phenol with acetone can be carried out in the presence of a suitable cocatalyst. US Pat. No. 5,399,433 and US Pat. No. 5,499,466 describe a process for making bisphenol A in the presence of an ion exchange catalyst and mercaptopropionic acid or mercaptan as a cocatalyst. It is known that catalysts deactivate over time. Deactivation is described, for example, in US Pat. No. 5,499,433, US Pat. No. 5,499,466 and US Pat. No. 5,599,466. One of the main objectives of the manufacturing process is to maximize the performance and residence time of the catalyst system. Therefore, to accommodate this objective, it is necessary to identify potential poisons, by-products, impurities in educts, etc.

[0005] US Patent No. 5,399,663 teaches the use of a specific catalyst system including an ion exchange resin catalyst and a sulfur-containing cocatalyst, the cocatalyst being chemically bound to the ion exchange resin catalyst, and also teaches a process for catalyzing the condensation reaction of phenols with ketones using the specific catalyst system. US Patent No. 5,399,663 further discloses a process for catalyzing the condensation reaction of phenols with ketones without utilizing a bulk promoter that is not chemically bound to the ion exchange resin catalyst.

[0006] Similarly, US Pat. No. 5,399,633 describes a process for making bisphenols in the presence of an acidic ion-exchange resin catalyst modified with a particular cationic compound.

[0007] Patent document 12 describes the production of BPA based on bio-derived phenol and / or bio-derived acetone in the presence of bio-derived impurities in the extract. This document only describes the use of promoter-bound ion-exchange resin catalysts, i.e., ion-bound ion-exchange resin catalysts with a promoter chemically bound (i.e., ionically bound). 2-Methylbenzofuran (2-MBF or MBF) was found to be a common impurity not only in fossil fuel-derived phenol but also in bio-derived phenol. It was found that 2-methylbenzofuran reacts completely during the reaction of phenol with acetone, so that no free 2-MBF is detected in the reaction product (BPA). Also, three new MBF reaction products were identified. Moreover, this BPA was visually pink, and polycarbonate made with this BPA also had an unacceptable color. At the same time, it was found that unknown MBF by-products obtained during the reaction of phenol with acetone, and not MBF itself, were responsible for this color. These unknown by-products could not be removed during BPA purification. Therefore, in order to obtain a low-color BPA PC, it is concluded that the amount of MBF in the bio-derived phenol must be as low as possible. This prior art document does not consider catalyst poisoning.

[0008] However, the removal of MBFs from raw phenol (whether fossil-based or bio-based) takes time and money, which makes the raw phenol more expensive. Ultimately, this increases the cost of bisphenol A and the respective polymers prepared from it. Furthermore, the concentration of MBFs in raw phenol varies depending on the source and purification process of these feedstocks. This means that different feedstock qualities need to be accommodated (e.g., if the specifications exceed a certain threshold, another purification step needs to be performed), reducing flexibility in the selection of processes and raw material sources. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] British Patent No. 849965 [Patent Document 2] U.S. Patent No. 4,427,793 [Patent Document 3] European Patent Application Publication No. 0007791 [Patent Document 4] European Patent Application Publication No. 0621252 [Patent Document 5] US Patent Application Publication No. 2005 / 0177006 [Patent Document 6] U.S. Patent No. 4,859,803 [Patent Document 7] European Patent Application Publication No. 0583712 [Patent Document 8] European Patent Application Publication No. 10620041 [Patent Document 9] DE 14312038 [Patent Document 10] International Publication No. 2012 / 150560 [Patent Document 11] European Patent Application Publication No. 1520617 [Patent Document 12] U.S. Patent No. 8,247,619 [Non-patent literature]

[0010] [Non-Patent Document 1] Chemistry and properties of crosslinked polymers, edited by Santokh S. Labana, Academic Press, New York 1977 Summary of the Invention

[0011] The present invention therefore aimed to provide a process for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A via condensation of phenol with acetone, which is more economical than the prior art processes. Furthermore, the present invention aimed to provide a process for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A via condensation of phenol with acetone, which allows more flexibility and / or allows greater flexibility in the selection of the quality of the raw phenol. This flexibility is preferably provided with respect to the concentration of 2-methylbenzofuran as an impurity in the raw phenol.

[0012] At least one of the above problems, preferably all of these problems, have been solved by the present invention. Surprisingly, it has been found that a catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst, where at least a portion of the sulfur-containing cocatalyst is not covalently or ionically bonded (i.e., not chemically bonded) to the ion exchange resin catalyst, is not susceptible to catalyst poisoning by 2-methylbenzofuran. Furthermore, the prior art teaches that the amount of 2-methylbenzofuran in the feed phenol should be as low as possible. Since the specific catalyst system of the present invention is not affected by this impurity, cheaper feed phenol can be used without the risk of shortening the catalyst life. This makes the overall process more cost-effective. Also, the process is more environmentally advantageous since less energy is required to purify the feed. Furthermore, the process allows more flexibility in the choice of feed phenol quality, in particular the concentration of 2-methylbenzofuran in these feeds.

[0013] Moreover, the prior art teaches that the use of a catalyst system having an ionic bond between the ion exchange resin and the cocatalyst results in the complete reaction of MBF during the reaction of acetone with phenol. The resulting MBF by-product also adversely affects the color of the BPA and the BPA PC obtained therefrom. Surprisingly, it has been found that the formation of such MBF by-products can be reduced by using a catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst, where at least a portion of the sulfur-containing cocatalyst, preferably at least 75 mol %, is not covalently or ionically bonded to the ion exchange resin catalyst. This means that a portion of the MBF present in the reaction is also present in the resulting BPA. In the prior art, it has already been determined that MBF itself does not significantly affect the color of the BPA and the BPA PC obtained therefrom. Thus, the use of the catalyst system of the present invention allows for a higher amount of MBF to be accepted in the raw phenol without significantly affecting the color of the resulting BPA and BPA PC. Again, this means that the overall process is more cost-effective. It also makes the process more environmentally favorable, since less energy is required to purify the raw material. Furthermore, the process allows greater flexibility in the selection of feed phenol quality, and in particular the concentration of 2-methylbenzofuran in these feedstocks.

[0014] Thus, the present invention provides (a) condensing feed phenol and feed acetone in the presence of a catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst, wherein at least a portion, preferably at least 75 mole percent, of the sulfur-containing cocatalyst is not covalently or ionically bonded to the ion exchange resin catalyst at the start of process step (a); 1. A process for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A, comprising: The amount of 2-methylbenzofuran present in step (a) is greater than 1 ppm, based on the total weight of the feed phenol.

[0015] According to the present invention, reference is made to "raw phenol" and / or "raw acetone". The term "raw" is used for the unreacted extract applied, especially added, in the process of making BPA. In particular, this term is used to distinguish between phenol newly added to the reaction (as raw phenol) and phenol recycled in the process of making BPA (recycled phenol). Such recycled phenol does not have the possibility of adding additional MBF to the process. The same is true for acetone newly added to the reaction (as raw acetone) and acetone recycled in the process of making BPA (recycled acetone). When referring to phenol and / or acetone, it is preferred to mean either the chemical compounds themselves or the sum of both raw phenol and recycled phenol and / or raw acetone and recycled acetone, unless otherwise specified.

[0016] MBF is an impurity in raw phenol, which is one of the products of the reaction of BPA. Raw phenol may contain MBF impurities. For example, routes to manufacture phenol are described in Arpe, Hans-Juergen, Industrielle Organische Chemie, 6. Auflage, January 2007, Wiley-VCH. In particular, processes to make phenol are described in the Ullmann Encyclopedia of Industrial Chemistry, chapter Phenol and Phenol Derivatives. The oxidation of cumene, also known as the Hock process, is by far the major route to synthesis of phenol. Among the poisons formed during the manufacture of phenol is 2-methylbenzofuran.

[0017] Furthermore, US Pat. No. 5,399,633 describes at least one process that provides bio-derived phenol that also contains MBF as an impurity.

[0018] The process of the present invention is characterised in that the amount of 2-methylbenzofuran present in step (a) is greater than 1 ppm, preferably greater than 2 ppm, more preferably greater than 3 ppm, even more preferably greater than 4 ppm, even more preferably greater than 5 ppm, even more preferably greater than 6 ppm, even more preferably greater than 7 ppm, even more preferably greater than 8 ppm, even more preferably greater than 9 ppm, even more preferably greater than 10 ppm, even more preferably greater than 11 ppm, even more preferably greater than 12 ppm, even more preferably greater than 13 ppm, even more preferably greater than 14 ppm, even more preferably greater than 15 ppm, even more preferably greater than 20 ppm, even more preferably greater than 25 ppm and most preferably greater than 50 ppm, based on the total weight of the feed phenol.

[0019] Further, it is preferred that the amount of MBF present in step (a) is greater than 1 ppm and not more than 5000 ppm, more preferably not more than 4500 ppm, even more preferably not more than 4000 ppm, even more preferably not more than 3500 ppm, even more preferably not more than 3000 ppm, even more preferably not more than 2500 ppm, and most preferably not more than 2000 ppm, based on the total weight of the raw phenol. It is understood that the upper limit values ​​presented here can be combined with the preferred lower limit values ​​presented above. Methods for determining the amount of MBF in the raw phenol are known to those skilled in the art. For example, the amount of 2-methylbenzofuran in the raw phenol can be determined according to ASTM D6142-12 (2013).

[0020] According to the present invention, "ppm" preferably refers to parts by weight.

[0021] According to the present invention, it was found that a by-product was formed due to the presence of MBF in reaction step (a), but not all of the MBF reacted to this impurity. This means that the MBF was not completely reacted to this impurity. This new by-product was analyzed by MS and a molecular weight of 226 g / mol was detected. This is because the C 15 H 14The atomic formula of O2 is suggested. Without being bound by theory, it is believed that phenol reacted with MBF. However, since no catalyst deactivation was observed, it is believed that this impurity (and all other possible impurities) does not poison the catalyst, at least in small amounts. It is therefore preferred to carry out process step (a) in the additional presence of at least one impurity formed due to the presence of MBF in process step (a). Furthermore, these impurities can be present in process step (a) if the phenol fraction of step (b) is recycled in process step (c).

[0022] It is further preferred that the process of the present invention is characterized in that 2-methylbenzofuran is present throughout the entire process step (a). As mentioned above, according to the present invention, it has been found that when using the catalyst system of the present invention, MBF is not completely reacted in process step (a). This means that a part of MBF is still present in the BPA. Based on the MBF present at the beginning of process step (a), preferably at least 5% by weight, more preferably at least 10% by weight, most preferably at least 15% by weight is also present at the end of process step (a), preferably at the beginning of process step (b) described below. Based on the MBF present at the beginning of process step (a), preferably at least 5% by weight, more preferably at least 10% by weight, most preferably at least 15% by weight is present in the resulting ortho,para-bisphenol A, ortho,ortho-bisphenol A, or para,para-bisphenol A.

[0023] Preferably, the process of the present invention comprises: (b) separating the mixture obtained after step (a) into a bisphenol A fraction comprising at least one of ortho,para-bisphenol A, ortho,ortho-bisphenol A, or para,para-bisphenol A, and a phenol fraction, The phenol fraction is characterized as additionally comprising a step of containing unreacted phenol and at least one impurity formed due to the presence of 2-methylbenzofuran in step (a).

[0024] The bisphenol A fraction is preferably recovered as a product and / or further purified. There are several variations in the manufacturing process to provide high purity bisphenol. This high purity is particularly important in the use of BPA as a monomer in the manufacture of polycarbonates. WO 0172677 describes crystals of an adduct of bisphenol with phenol and a method for producing the crystals and ultimately making bisphenol. It has been found that high purity para,para-BPA can be obtained by crystallization of the adduct. EP 1944284 describes a process for producing bisphenol, in which the crystallization comprises a continuous suspension crystallizer. It is stated that there is an increasing demand for the purity of BPA and that the disclosed method allows very pure BPA of more than 99.7% to be obtained. WO 2005075397 describes a process for producing bisphenol A, in which the water formed during the reaction is removed by distillation. In this way, unreacted acetone is recovered and recycled, resulting in an economically advantageous process.

[0025] The process of the invention is preferably characterized in that the separation in step (b) is carried out using a crystallization method, more preferably the separation in step (b) is carried out using at least one continuous suspension crystallizer.

[0026] It was further described that a mother liquor cycle is used. After the reaction, the BPA is removed from the solvent by crystallization and filtration. The mother liquor typically contains 5% to 20% BPA dissolved in unreacted phenol and by-products. Furthermore, water is formed during the reaction, which is removed from the mother liquor in a dehydration section. The fraction containing unreacted phenol is preferably recycled for further reaction, which preferably means recycling the mother liquor. This fraction is reused as unreacted phenol in the reaction with acetone to obtain BPA. The mother liquor stream is preferably recycled to the reaction unit according to conventional methods.

[0027] Typically, by-products in the mother liquor are, for example, o,p-BPA, o,o-BPA, substituted indenes, hydroxyphenylindanols, hydroxyphenylchromans, substituted xanthenes, and higher condensed compounds. Also, as a result of acetone self-condensation and reaction with impurities in the feedstock, further secondary compounds such as anisole, mesityl oxide, mesitylene, and diacetone alcohol may be formed.

[0028] Recycling of the mother liquor can lead to the accumulation of by-products in the circulation stream, which can lead to further deactivation of the catalytic system. This means that when using the catalyst for long periods of time, it is necessary to consider the influence of by-products that may arise in the reaction itself, either from the reaction of phenol with acetone or from the reaction of one of the impurities, as well as the influence of initial impurities in the extract.

[0029] More preferably, the process according to the invention comprises the steps of: (c) comprising an additional step of using at least a portion of the phenol fraction obtained in step (b) as an extract in step (a).

[0030] More preferably, said portion of the phenol fraction comprises at least 5 wt. %, more preferably at least 10 wt. %, and most preferably at least 15 wt. % MBF, where the weight percentage of MBF refers to said portion of MBF compared to the MBF present in the starting phenol.

[0031] In order to avoid the accumulation of the introduced MBF, by-products and / or impurities formed due to the presence of MBF in step (a), several options exist in the system. The options include, in particular, a purge stream, waste water, off-gas and BPA itself as product. The main stream would be a purge stream, for example discharging a portion of the mother liquor. Another approach involves passing a portion of the total amount of the circulating stream after the solid-liquid separation and before or after the removal of water and residual acetone, for example through a rearrangement unit filled with an acid ion exchanger. In this rearrangement unit, a portion of the by-products from the preparation of BPA are isomerized to obtain p,p-BPA. It has been found that the new impurities formed due to the presence of MBF in process step (a) can be at least partially removed by the purge stream. It is therefore preferred to use at least a portion of the phenol fraction obtained in step (b) as extract in step (a) and to purge at least a portion of this stream. It is preferred that more than 50% by volume of the phenolic fraction obtained in step (b) is used as extract in step (a), where the % by volume is relative to the total volume of the phenolic fraction.

[0032] The catalyst systems that can be used in the process of the present invention are known to those skilled in the art. The catalyst system is preferably an acidic ion exchange resin. Such an ion exchange resin can have a crosslinking of 2% to 20%, preferably 3% to 10%, most preferably 3.5% to 5.5%. The acidic ion exchange resin can preferably be selected from the group consisting of sulfonated styrene divinylbenzene resin, sulfonated styrene resin, phenol formaldehyde sulfonic acid resin, and benzene formaldehyde sulfonic acid. Furthermore, the ion exchange resin can contain sulfonic acid groups. The catalyst bed can be either a fixed bed or a fluidized bed.

[0033] Furthermore, the catalyst system of the present invention comprises a sulfur-containing cocatalyst, at least a portion of which is not covalently or ionically bonded to the ion exchange resin catalyst. The sulfur-containing cocatalyst can be one substance or a mixture of at least two substances. The cocatalyst is preferably dissolved in the reaction solution of process step (a). More preferably, the cocatalyst is homogeneously dissolved in the reaction solution of process step (a). The process of the present invention is preferably characterized in that the sulfur-containing cocatalyst is selected from the group consisting of mercaptopropionic acid, hydrogen sulfide, alkyl sulfides such as ethyl sulfide, and mixtures thereof. Most preferably, the sulfur-containing cocatalyst is 3-mercaptopropionic acid.

[0034] The catalyst system of the present invention comprises a sulfur-containing cocatalyst, and preferably, all of the sulfur-containing cocatalyst is not covalently or ionically bonded to the ion-exchange resin catalyst. This means that preferably, all of the sulfur-containing cocatalyst is added in process step (a). According to the present invention, the expressions "not chemically bonded" or "not covalently or ionically bonded" refer to a catalyst system in which, at the start of process step (a), there are no covalent or ionic bonds between the ion-exchange resin catalyst and the sulfur-containing cocatalyst. However, this does not mean that at least a part of the sulfur-containing cocatalyst may be fixed to the heterogeneous catalyst matrix via ionic or covalent bonds. In any case, at the start of process step (a), such ionic or covalent bonds of the sulfur-containing cocatalyst are not present and, if they are formed at all, they are formed over time. Therefore, it is preferred to add the sulfur-containing cocatalyst to process step (a). The term "addition" denotes an active process step. This means that, as mentioned above, it is preferred to dissolve the cocatalyst in the reaction solution of process step (a). Additionally, the co-catalyst may be added in any other process step or may be added more than once in process step (a). Furthermore, it is preferred that the majority of the sulfur-containing co-catalyst is not covalently or ionically bonded to the ion exchange resin catalyst. This means that at least 75 mol %, more preferably at least 80 mol %, and most preferably at least 90 mol % of the sulfur-containing co-catalyst is not chemically bonded to the ion exchange resin catalyst, where the mol % is relative to the total co-catalyst present in process step (a).

[0035] Since MBF is a common impurity in raw phenol, it is preferred that the MBF present in step (a) is introduced into process step (a) as an impurity in the raw phenol. In this situation, at least a portion of the MBF may be present in process step (a) for other reasons. For example, a portion of the MBF present in process step (a) may be present for phenol recycle.

[0036] The process according to the invention is furthermore characterised in that the feed phenol used in process step (a) is bio-based.More preferably the feed phenol containing MBF as an impurity is bio-based.

[0037] As used in accordance with the present invention, the term "bio-derived" or "bio-based" refers to (raw) phenol obtained from currently renewable resources. In particular, the term is used in contrast to phenol derived from fossil fuels. Whether a raw material is bio-based can be confirmed by measuring the carbon isotope level, since the relative amount of the carbon isotope C14 is lower in fossil fuel materials. Such measurements, which can be performed according to, for example, ASTM D6866-18 (2018) or ISO 16620-1 to -5 (2015), are known to those skilled in the art.

[0038] In another aspect, the present invention provides a method for producing a pharmaceutical composition comprising: (i) in any or preferred embodiment, obtaining ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A by the process of the present invention; (ii) polymerizing the ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A obtained in step (i), optionally in the presence of at least one further monomer, to obtain a polycarbonate; The present invention provides a process for making a polycarbonate comprising:

[0039] As explained above, the process for producing ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A of the present invention provides BPA that can be obtained in a more economical and / or environmentally friendly manner. Therefore, the use of this BPA obtained by the process according to the present invention also makes the process for making polycarbonate according to the present invention more economical and / or environmentally friendly.

[0040] Reaction step (ii) is known to those skilled in the art. The polycarbonates can be prepared in known manner from BPA, carbonic acid derivatives, optional chain terminators, and optional branching agents by interphase phosgenation or melt transesterification.

[0041] In interphase phosgenation, the bisphenol and any branching agent are dissolved in an aqueous alkaline solution and reacted with a carbonic acid source, such as phosgene, optionally dissolved in a solvent, in a two-phase mixture containing an aqueous alkaline solution, an organic solvent and a catalyst, preferably an amine compound. The reaction procedure can also be carried out in several stages. Such processes for making polycarbonates are known in principle as interfacial processes, for example in H. Schnell, Chemistry and Physics of Polycarbonates, Polymer Reviews, Vol. 9, Interscience Publishers, New York 1964 page 33 et seq. and Polymer Reviews, Vol. 10, "Condensation Polymers by Interfacial and Solution Methods", Paul W. Morgan, Interscience Publishers, New York 1965, chapter VIII, page 325, so that the basic conditions are well known to those skilled in the art.

[0042] Alternatively, polycarbonates can also be prepared by melt transesterification process.The melt transesterification process is described, for example, in Encyclopedia of Polymer Science, Vol. 10 (1969), Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, Vol. 9, John Wiley and Sons, Inc. (1964), and in German Patent Application Publication No. 1031512.In the melt transesterification process, the aromatic dihydroxy compounds already described in the interfacial process are transesterified with carbonic acid diesters in the melt with the aid of suitable catalysts and any further additives.

[0043] Preferably, the process for making polycarbonates according to the invention is characterized in that process step (i) further comprises a step of purifying ortho,para-bisphenol A, ortho,ortho-bisphenol A and / or para,para-bisphenol A in order to reduce the amount of at least one impurity formed due to the presence of MBF in step (a). As mentioned above, cheaper raw phenols can be used in the process of the invention. However, if MBF is present as an impurity in these cheaper raw materials, other impurities are formed. These impurities are preferably removed before polymerization. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0044] The materials used in the examples are as follows:

[0045] TIFF2024507889000001.tif49170

[0046] The column reactor was equipped with 150 g of phenol wet catalyst (amount of phenol wet catalyst in the reactor: 210 ml-230 ml). The column reactor was heated to 60° C. (catalyst bed temperature during the reaction: 63° C.). A mixture of phenol, acetone (3.9 wt %), and MEPA (160 ppm relative to the total mass of phenol and acetone) was prepared and heated to 60° C. This mixture was pressed into the column reactor at a flow rate of 45 g / h. The column reactor had a sampling point at the bottom. Various samples were taken during the reaction using the opening of the sampling point. The sampling time was 1 hour, and the amount of sample taken every hour was 45 g.

[0047] The first run (standard run) was carried out for 52 hours. Samples were taken and analyzed by GC after 48, 49, 50, and 51 hours.

[0048] A second run (impurity run) was performed for 52 hours. At the beginning of the second run, 1590 ppm of 2-methylbenzofuran (relative to the combined mass of phenol and acetone) was dosed to the reaction system. Samples were taken and analyzed by GC after 48, 49, 50, and 51 hours, respectively. A third run (standard run) was then performed for 52 hours using a new mixture of acetone, phenol, and MEPA. Samples were taken via syringe and analyzed by GC after 48, 49, 50, and 51 hours, respectively. A fourth run (impurity run) was then performed for 52 hours. At the beginning of the fourth run, 1580 ppm of 2-methylbenzofuran (relative to the combined mass of phenol and acetone) was dosed to the reaction system. Samples were taken and analyzed by GC after 48, 49, 50, and 51 hours, respectively. Finally, a fifth run (standard run) was performed for 52 hours. Samples were taken after 48, 49, 50, and 51 hours and analyzed by GC.

[0049] Gas chromatography (GC) of methanol was performed using an Agilent J&W VF-1MS column (100% dimethylpolysiloxane) with dimensions of 50 m x 0.25 mm x 0.25 μm, with a temperature profile of 60° C. for 0.10 min, heating at 12° C. / min to 320° C. and holding at this temperature for 10.00 min, at 300° C. with a 10 / 1 split to inject 1 μl of sample, with a flow rate of 2 ml / min at an initial pressure of 18.3 psi (1.26 bar).

[0050] Gas chromatography (GC) of 2-methylbenzofuran, phenol, and para,para-BPA was performed using an Agilent J&W VF-1MS column (100% dimethylpolysiloxane) with dimensions of 50 m x 0.25 mm x 0.25 μm, with a temperature profile of 80°C for 0.10 min, heating at 12°C / min to 320°C and holding at this temperature for 10.00 min, with a 10 / 1 split at 300°C to inject 1 μl of sample, with a flow rate of 2 ml / min at an initial pressure of 18.3 psi (1.26 bar).

[0051] Gas chromatography (GC) coupled with mass spectrometry (MS) for the identification of unknown compounds is performed using an Agilent J&W VF-1MS column (100% dimethylpolysiloxane) with dimensions of 30 m x 0.25 mm x 0.25 μm, injecting 0.5 μl of sample with a 10 / 1 split at 250 °C, using a temperature profile of 0.10 min at 60 °C, heating at 12 °C / min to 350 °C and holding at this temperature for 5 min, where the flow rate is 1 ml / min with an initial pressure of 24.45 psi (1.685768 bar), and the mass spectrometer scans from mz35 to mz700.

[0052] The standard runs represent the reaction of acetone with phenol to form BPA in the presence of catalyst and cocatalyst. From the standard runs, the acetone conversion, including the respective error bars, can be estimated. This conversion represented a baseline for evaluating whether impurities affect the deactivation of the catalyst. The acetone conversion in the third and fifth standard runs was compared with that of the first standard run to determine the effect of 2-methylbenzofuran on the catalyst. If the acetone conversion is lower than this conversion, it indicates that 2-methylbenzofuran affects the BPA catalyst. To show that this type of evaluation can be used to determine catalyst poisoning, a reference run was performed using methanol as an impurity. Methanol is known from the current state of the art to be a known poison for catalysts in the BPA process, as described, for example, in US Pat. No. 8,143,456. The respective results are shown in Table 1. The values ​​shown in the table are the average values ​​obtained from four samples taken during each run (after 48 hours, 49 hours, 50 hours, and 51 hours).

[0053] TIFF2024507889000002.tif44170

[0054] As can be clearly seen from Table 1, the acetone conversion rate decreased in the first, third and fifth standard runs, which means that the catalyst was poisoned by methanol and could not recover the conversion rate due to the irreversible reaction that reduced the catalytic activity.

[0055] The following table shows the results of the first run (standard run), second run (impurity run), third run (standard run), fourth run (impurity run), and fifth run (standard run) for 2-methylbenzofuran as an impurity. The values ​​shown in the table are the average values ​​obtained from four samples taken during each run (after 48 hours, 49 hours, 50 hours, and 51 hours).

[0056] TIFF2024507889000003.tif94170

[0057] As can be seen from the results in Table 2, the addition of 2-methylbenzofuran in the reaction of phenol with acetone to para,para-BPA causes almost no decrease in the acetone conversion in the first, third and fifth standard runs. This means that MBF is not a poison for the catalyst system used. This effect is seen after each impurity run. Furthermore, it can be seen that during the impurity run, some MBF still leaves the reactor (2-methylbenzofuran OUT can be detected). This means that during the impurity run, not all MBF reacts. Furthermore, at least one unknown compound was found to have a molecular weight of 226 g / mol.

Claims

1. (a) condensing a feed phenol with a feed acetone in the presence of a catalyst system, the catalyst system comprises an ion exchange resin catalyst and a sulfur-containing cocatalyst, and at least a portion of the sulfur-containing cocatalyst is not covalently or ionically bonded to the ion exchange resin catalyst at the start of process step (a); 1. A process for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A, comprising:

13. The process of claim 12, wherein the amount of 2-methylbenzofuran present in step (a) is greater than 1 ppm based on the total weight of the feed phenol.

2. 2. The process according to claim 1, characterized in that step (a) is carried out in the additional presence of at least one impurity formed due to the presence of 2-methylbenzofuran in step (a).

3. 3. The process of claim 1 or 2, characterized in that said 2-methylbenzofuran is present throughout said process step (a).

4. (b) separating the mixture obtained after step (a) into a bisphenol A fraction comprising at least one of ortho,para-bisphenol A, ortho,ortho-bisphenol A, or para,para-bisphenol A, and a phenol fraction, 4. The process according to claim 1, further comprising the step, wherein the phenol fraction contains unreacted phenol and at least one impurity formed due to the presence of 2-methylbenzofuran in step (a).

5. 5. The process according to claim 4, characterized in that it comprises the additional step of: (c) using at least a portion of the phenolic fraction obtained in step (b) as extract in step (a).

6. 6. The process according to any one of claims 1 to 5, characterized in that the sulfur-containing cocatalyst is selected from the group consisting of mercaptopropionic acid, hydrogen sulfide, alkyl sulfides such as ethyl sulfide, and mixtures thereof.

7. 7. The process according to any one of claims 1 to 6, characterized in that the 2-methylbenzofuran present in step (a) is introduced into process step (a) as an impurity in the raw phenol.

8. (i) obtaining ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A according to the process of any one of claims 1 to 7; (ii) polymerizing the ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A obtained in step (i), optionally in the presence of at least one further monomer, to obtain a polycarbonate; A process for making a polycarbonate comprising: