Process for making bisphenol A (BPA) in the presence of acetophenone

Abstract

The present invention relates to a method for making bisphenol A in the presence of acetophenone without poisoning a catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst. Additionally, the present invention provides a method for making polycarbonate.

Description

[Technical Field]

[0001] The present invention relates to a process for making bisphenol A and 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) can also be formed in the production of BPA. When referring to BPA, the general term refers to para,para-BPA, but small amounts of ortho,ortho-BPA and / or ortho,para-BPA are also included.

[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 commercial processes for the condensation reaction. Currently, heterogeneous continuous processes for the production of BPA are used in the presence of ion-exchange resin catalysts, where the ion-exchange resin contains crosslinked, acid-functionalized polystyrene resin. The most important resins are polystyrene crosslinked by sulfonic acid groups. Divinylbenzene is most often used as a crosslinking agent, as described in U.S. Patent Nos. 5,629,999; 5,729,999; 5,829,999; and 5,929,999, or 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 co-catalyst. Patent documents 5 and 6 describe a process for producing bisphenol A in the presence of an ion exchange catalyst and mercaptopropionic acid or mercaptan as a co-catalyst. Catalysts are known to deactivate over time. Deactivation is described, for example, in patent documents 7, 8, and 9. One of the main objectives of the production process is to maximize the performance and residence time of the catalyst system. Therefore, to address this objective, it is necessary to identify potential poisons, by-products, impurities in educts, etc.

[0005] Patent Document 10 teaches the use of a specific catalyst system including an ion exchange resin catalyst and a sulfur-containing co-catalyst, where the co-catalyst is chemically bound to the ion exchange resin catalyst, and also teaches a process for catalyzing the condensation reaction of phenols with ketones using such a specific catalyst system. Furthermore, Patent Document 10 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. 5,629,999 describes a process for producing bisphenols in the presence of an acidic ion-exchange resin catalyst modified with a specific 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 exchange resin catalysts to which a promoter is chemically bound (i.e., ionically bound). This prior art document does not consider catalyst poisoning.

[0008] Acetophenone is one of the impurities that may be present in the starting phenol, and as mentioned above, it is common to try to avoid or reduce the amount of impurities as much as possible in order to avoid any side reactions, catalyst poisoning, etc. in the desired reaction.

[0009] However, removing acetophenone from raw phenol (whether fossil-based or bio-based) takes time and money, making the raw phenol more expensive. Ultimately, this increases the cost of bisphenol A and the respective polymers prepared from this bisphenol A. Furthermore, the concentration of acetophenone in raw phenol varies depending on the source and purification process of these feedstocks. This means that different feedstock qualities must be accommodated (e.g., if specifications exceed a certain threshold, a separate purification step must be performed), reducing flexibility in the selection of process and raw material source. [Prior art documents] [Patent documents]

[0010] [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] U.S. 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] German Patent Application Publication No. 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]

[0011] [Non-Patent Document 1] Chemistry and properties of crosslinked polymers, edited by Santokh S. Labana, Academic Press, New York 1977 Summary of the Invention

[0012] Thus, the present invention has been directed to a process for producing ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A via the condensation of phenol with acetone, which is more economical than prior art processes. Furthermore, the present invention has been directed to a process for producing ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A via the condensation of phenol with acetone, which allows greater 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 acetophenone as an impurity in the raw phenol.

[0013] The present invention solves at least one of the above-mentioned problems, and preferably all of them. Surprisingly, it has been found that catalyst systems comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst are less susceptible to catalyst poisoning by acetophenone. Furthermore, it has been found that catalyst systems comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst, wherein 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, are less susceptible to catalyst poisoning by acetophenone. Furthermore, the amount of acetophenone in the feed phenol is typically as low as possible. Because certain catalyst systems of the present invention are not affected by this impurity, cheaper feed phenol can be used without risk of shortened catalyst life. This makes the overall process more cost-effective. Furthermore, the process is more environmentally friendly because less energy is required to purify the feed. Furthermore, the process allows greater flexibility in the selection of feed phenol quality, particularly with regard to the concentration of acetophenone in these feeds.

[0014] Therefore, the present invention provides (a) condensing feed phenol and feed acetone in the presence of a catalyst system, the catalyst system comprising an ion exchange resin catalyst and a sulfur-containing co-catalyst; 1. A process for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A, comprising: The amount of acetophenone 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 unreacted extracts 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 may not add additional acetophenone to the process. The same applies to 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, unless otherwise specified, it is preferable to mean either the chemical compounds themselves or the sum of both raw phenol and recycled phenol and / or raw acetone and recycled acetone.

[0016] Acetophenone is an impurity in raw phenol, one of the products of the BPA reaction. Raw phenol may contain acetophenone impurities. For example, the manufacturing pathway for phenol is described in Arpe, Hans-Juergen, Industrielle Organische Chemie, 6. Auflage, January 2007, Wiley-VCH. In particular, the process for making phenol is described in the Ullmann Encyclopedia of Industrial Chemistry, chapter on phenol and phenol derivatives. The oxidation of cumene, also known as the Hock process, is by far the primary synthetic route for phenol. Among the toxic substances formed during the production of phenol is acetophenone.

[0017] The process of the present invention is characterised in that the amount of acetophenone present in step (a) is greater than 1 ppm, preferably greater than 1.5 ppm, more preferably greater than 2 ppm, more preferably greater than 2.5 ppm, more preferably greater than 3 ppm, even more preferably greater than 4 ppm, even more preferably greater than 5 ppm, 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 15 ppm, even more preferably greater than 20 ppm and most preferably greater than 50 ppm, based on the total weight of the feed phenol.

[0018] Furthermore, it is preferred that the amount of acetophenone present in step (a) is greater than 1 ppm and not greater than 5000 ppm, more preferably not greater than 4500 ppm, even more preferably not greater than 4000 ppm, even more preferably not greater than 3500 ppm, even more preferably not greater than 3000 ppm, even more preferably not greater than 2500 ppm, and most preferably not greater than 2000 ppm, based on the total weight of the starting phenol. It is understood that the upper limit values ​​provided herein can be combined with the preferred lower limit values ​​provided above. Methods for determining the amount of MBF in the starting phenol are known to those skilled in the art. For example, the amount of 2-acetophenone in the starting phenol can be determined according to ASTM D6142-12(2013).

[0019] According to the present invention, "ppm" preferably refers to parts by weight.

[0020] The process of the present invention is preferably characterized in that acetophenone is present throughout process step (a). It has been found that, when using the catalyst system of the present invention, acetophenone does not react or reacts only to a very small extent in process step (a). This means that at least a portion, preferably all, of the acetophenone is still present at the completion of process step (a) and / or in the resulting BPA. Based on the acetophenone present at the beginning of process step (a), preferably at least 25% by weight, more preferably at least 50% by weight, and most preferably at least 75% by weight is still present at the completion of process step (a), preferably at the beginning of process step (b) described below. Based on the acetophenone present at the beginning of process step (a), preferably at least 25% by weight, more preferably at least 50% by weight, and most preferably at least 75% by weight is still present in the resulting ortho,para-bisphenol A, ortho,ortho-bisphenol A, or para,para-bisphenol A.

[0021] Preferably, the process of the present invention comprises: (b) separating the mixture obtained after step (a) into a bisphenol A fraction containing 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 by the additional step of containing unreacted phenol and acetophenone.

[0022] The bisphenol A fraction is preferably recovered as a product and / or further purified. Several variations in the manufacturing process exist to provide highly pure bisphenol. This high purity is particularly important in the use of BPA as a monomer in the production of polycarbonate. International Publication No. 0172677 describes crystals of an adduct of bisphenol and phenol and a method for producing the crystals and ultimately producing bisphenol. It has been found that highly pure para,para-BPA can be obtained by crystallizing the adduct. European Patent Application Publication No. 1944284 describes a process for producing bisphenol, in which the crystallization involves a continuous suspension crystallizer. It is noted that the demand for purity of BPA is increasing, and that the disclosed method can produce highly pure BPA with a purity of over 99.7%. International Publication No. 2005075397 describes a process for producing bisphenol A, in which water produced during the reaction is removed by distillation. This method allows unreacted acetone to be recovered and recycled, resulting in an economically advantageous process.

[0023] The process of the present invention is preferably characterized in that the separation in step (b) is carried out using a crystallization method, more preferably by using at least one continuous suspension crystallizer.

[0024] The use of a mother liquor cycle was also described. After the reaction, 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, and this water 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 in a conventional manner.

[0025] 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. Additionally, as a result of acetone self-condensation and reaction with impurities in the raw materials, further secondary compounds such as anisole, mesityl oxide, mesitylene, and diacetone alcohol may be formed.

[0026] Recycling of the mother liquor can lead to the accumulation of by-products in the recycle 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.

[0027] More preferably, the process according to the invention comprises (c) The method is characterized by including an additional step of using at least a portion of the phenol fraction obtained in step (b) as the extract in step (a).

[0028] It is further preferred that said portion of the phenolic fraction comprises at least 10% by weight, more preferably at least 25% by weight, and most preferably at least 50% by weight of acetophenone, where weight percent of acetophenone refers to said portion of acetophenone compared to acetophenone present in the starting phenol.

[0029] To avoid the accumulation of introduced acetophenone, by-products, and / or impurities (either those added with the raw extract or those that may be formed in the system due to the presence of acetophenone in step (a)), several options exist. These options include, inter alia, a purge stream, wastewater, 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 solid-liquid separation and before or after removing water and residual acetone through a rearrangement unit, for example, filled with an acid ion exchanger. In this rearrangement unit, some of the by-products from the preparation of BPA are isomerized to obtain p,p-BPA. It is believed that acetophenone can be at least partially removed by the purge stream. Therefore, it is preferred to use at least a portion of the phenol fraction obtained in step (b) as the extract in step (a) and to purge at least a portion of this stream. It is preferred to use more than 50% by volume of the phenol fraction obtained in step (b) as the extract in step (a). Here, the volume percentages are relative to the total volume of the phenol fraction.

[0030] According to the present invention, a catalyst system is used that includes an ion exchange resin and a sulfur-containing cocatalyst. These catalyst systems are known to those skilled in the art. In particular, there are two different types of catalyst systems: one is commonly referred to as a "promoted catalyst" and the other is commonly referred to as an "unpromoted catalyst." A promoted catalyst includes a cocatalyst that is bound to a portion of the ion exchange resin. This bond can be either ionic or covalent in nature. Examples of such promoted catalyst systems are described, for example, in U.S. Patent No. 5,414,151, U.S. Patent Application Publication No. 2004 / 0192975, U.S. Patent No. 5,414,151, and the like. On the other hand, in an "unpromoted catalyst" system, the cocatalyst is typically not bound to the ion exchange resin.

[0031] Ion exchange resins that can be used in the process of the present invention are known to those skilled in the art. The ion exchange resin is preferably an acidic ion exchange resin. Such an ion exchange resin may have a crosslinking of 2% to 20%, preferably 3% to 10%, and most preferably 3.5% to 5.5%. The acidic ion exchange resin may 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 may contain sulfonic acid groups. The catalyst bed may be either a fixed bed or a fluidized bed.

[0032] The catalyst system of the present invention further includes a sulfur-containing cocatalyst. The sulfur-containing cocatalyst can be one substance or a mixture of at least two substances. Preferably, the sulfur-containing cocatalyst is selected from the group consisting of mercaptopropionic acid, hydrogen sulfide, alkyl sulfides such as ethyl sulfide, mercaptoalkylpyridines, mercaptoalkylamines, thiazolidins, aminothiophenols, and mixtures thereof. In the case of promoted catalysts, the sulfur-containing cocatalyst is preferably selected from mercaptoalkylpyridines such as 3-mercaptomethylpyridine, 3-(2-mercaptoethyl)pyridine, and 4-(2-mercaptoethyl)pyridine; mercaptoalkylamines such as 2-mercaptoethylamine, 3-mercaptopropylamine, and 4-mercaptobutylamine; thiazolidins such as thiazolidine, 2-2-dimethylthiazolidine, 2-methyl-2-phenylthiazolidine, and 3-methylthiazolidine; aminothiophenols such as 4-methylthiophenol, and mixtures thereof. In the case of an unpromoted catalyst, the sulfur-containing cocatalyst is selected from the group consisting of mercaptopropionic acid, hydrogen sulfide, alkyl sulfides such as ethyl sulfide, and mixtures thereof. According to the present invention, it is preferred to use an unpromoted catalyst system. This means that in the catalyst system, at the start of process step (a), at least a portion, preferably at least 75 mole %, of the sulfur-containing cocatalyst is preferably not covalently or ionically bonded to the ion exchange resin catalyst.

[0033] In this case, the co-catalyst is preferably dissolved in the reaction solution of process step (a). More preferably, the co-catalyst 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 co-catalyst 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 co-catalyst is 3-mercaptopropionic acid.

[0034] The catalyst system of the present invention includes a sulfur-containing cocatalyst, and it is preferred that none of the sulfur-containing cocatalyst is 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 terms "not chemically bonded" or "not covalently or ionically bonded" refer to a catalyst system in which, at the start of process step (a), there is no covalent or ionic bond between the ion-exchange resin catalyst and the sulfur-containing cocatalyst. However, this does not mean that at least a portion of the sulfur-containing cocatalyst may be fixed to the heterogeneous catalyst matrix via an ionic or covalent bond. In any case, at the start of process step (a), such ionic or covalent bonds of the sulfur-containing cocatalyst do not exist, and if they are formed, they are formed over time. Therefore, it is preferred that the sulfur-containing cocatalyst is added in process step (a). The term "addition" refers to an active process step. This means that, as described above, it is preferred that the cocatalyst is dissolved 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 a 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 mole percent, more preferably at least 80 mole percent, and most preferably at least 90 mole percent of the sulfur-containing co-catalyst is not chemically bonded to the ion exchange resin catalyst. Here, mole percent refers to the total co-catalyst present in process step (a).

[0035] Since acetophenone is a common impurity in raw phenol, it is preferred that the acetophenone 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 acetophenone may be present in process step (a) for other reasons. For example, a portion of the acetophenone present in process step (a) may be present due to phenol recycle.

[0036] According to the present invention, the raw phenol and / or raw acetone used in process step (a) may be bio-based.

[0037] As used in accordance with the present invention, the terms "bio-derived" or "bio-based" refer to (raw) phenol and / or (raw) acetone obtained from currently renewable resources. In particular, the term is used in contrast to phenol derived from fossil fuels. Whether a feedstock is bio-based can be confirmed by measuring carbon isotope levels, 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 polycarbonates according to the present invention more economical and / or environmentally friendly.

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

[0041] In interphase phosgenation, a bisphenol and an optional branching agent are dissolved in an aqueous alkaline solution and reacted with a carbonate 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 multiple stages. This process for making polycarbonates is known in principle as an interfacial process, 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, and therefore the basic conditions are well known to those skilled in the art.

[0042] Alternatively, polycarbonates can also be prepared by melt transesterification. 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 German Patent Application Publication No. 1031512. In the melt transesterification process, aromatic dihydroxy compounds already described in the interfacial process are transesterified with carbonic acid diesters in the melt with the aid of a suitable catalyst and any further additives.

[0043] Preferably, the process for making polycarbonates according to the present invention is characterized in that process step (i) further comprises purifying ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A to reduce the amount of acetophenone. As mentioned above, cheaper raw phenols can be used in the process of the present invention. However, if acetophenone is present as an impurity in these cheaper raw materials, it is believed that this impurity is substantially unreacted. Therefore, acetophenone is preferably removed prior to polymerization. This removal is preferably carried out using the crystallization method described above. DETAILED DESCRIPTION OF THE INVENTION [Example]

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

[0045] TIFF2024508776000001.tif50170

[0046] The column reactor was equipped with 150 g of phenol wet catalyst (amount of phenol wet catalyst in the reactor: 210 ml to 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 pressurized 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, after which samples were taken and analyzed by GC at 48, 49, 50, and 51 hours.

[0048] A second run (impurity run) was conducted for 52 hours. At the beginning of the second run, 1670 ppm of acetophenone (relative to the combined mass of phenol and acetone) was dosed to the reaction system. Samples were taken after 48, 49, 50, and 51 hours and analyzed by GC. A third run (standard run) was then conducted for 52 hours using a new mixture of acetone, phenol, and MEPA. Samples were taken via syringe after 48, 49, 50, and 51 hours and analyzed by GC. A fourth run (impurity run) was then conducted for 52 hours. At the beginning of the fourth run, 1680 ppm of acetophenone (relative to the combined mass of phenol and acetone) was dosed to the reaction system. Samples were taken after 48, 49, 50, and 51 hours and analyzed by GC. Finally, a fifth run (standard run) was conducted for 52 hours. Samples were taken after 48 hours, 49 hours, 50 hours, and 51 hours, respectively, and analyzed by GC.

[0049] Gas chromatography (GC) of methanol was performed using a 50 m × 0.25 mm × 0.25 μm Agilent J&W VF-1MS column (100% dimethylpolysiloxane) 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, with a 10 / 1 split injection of 1 μl of sample at 300°C, where the flow rate was 2 ml / min at an initial pressure of 18.3 psi (1.26 bar).

[0050] Gas chromatography (GC) of acetophenone, phenol, and para,para-BPA was performed using a 50 m × 0.25 mm × 0.25 μm Agilent J&W VF-1MS column (100% dimethylpolysiloxane) 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 1 μl sample injection at 300°C with a 10 / 1 split, and a flow rate of 2 ml / min at an initial pressure of 18.3 psi (1.26 bar).

[0051] The standard runs represent the reaction of acetone with phenol to form BPA in the presence of a catalyst and cocatalyst. From the standard runs, the acetone conversion, including the respective error bars, could be estimated. This conversion represented a baseline for assessing whether impurities affected catalyst deactivation. The acetone conversions in the third and fifth standard runs were compared with those in the first standard run to determine the effect of acetophenone on the catalyst. A lower acetone conversion indicates that acetophenone is affecting the BPA catalyst. To demonstrate that this type of evaluation can be used to determine catalyst poisoning, a reference run was performed using methanol as an impurity. Methanol, as described, for example, in U.S. Patent No. 8,143,456, is a known poison for catalysts in BPA processes. The respective results are shown in Table 1. The values ​​shown in the table are averages obtained from four samples taken during each run (48 hours, 49 hours, 50 hours, and 51 hours).

[0052] TIFF2024508776000002.tif49170

[0053] 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 irreversible reactions that reduced the catalytic activity.

[0054] The following table shows the results for the first run (standard run), second run (impurity run), third run (standard run), fourth run (impurity run), and fifth run (standard run) for acetophenone as an impurity. The values ​​shown in the table are the average values ​​obtained from four samples taken during each run (48 hours, 49 hours, 50 hours, and 51 hours).

[0055] TIFF2024508776000003.tif72170

[0056] As can be seen from the results in Table 2, the addition of acetophenone to the reaction of phenol with acetone to produce para,para-BPA causes little decrease in acetone conversion in the first, third, and fifth standard runs. This means that acetophenone is not a poison for the catalyst system used. This effect is evident after each impurity run. Furthermore, it can be seen that acetophenone does not appear to react at all in this system (acetophenone OUT is approximately equal to acetophenone IN).

Claims

1. (a) condensing feed phenol and feed acetone in the presence of a catalyst system, the catalyst system comprising an ion exchange resin catalyst and a sulfur-containing cocatalyst; 1. A method for making ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A, comprising:

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

2. 2. The method of claim 1, wherein the catalyst system comprises at least a portion of the sulfur-containing cocatalyst that is not covalently or ionically bonded to the ion exchange resin catalyst in the catalyst system at the start of step (a).

3. 3. The process according to claim 1 or 2, characterized in that the acetophenone is present throughout 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 method according to claim 1, further comprising the step of: the phenol fraction comprising unreacted phenol and acetophenone.

5. 5. The method 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, mercaptoalkylpyridines, mercaptoalkylamines, thiazolidines, aminothiophenols, and mixtures thereof.

7. 7. The method according to claim 1, wherein the acetophenone present in step (a) is introduced into step (a) as an impurity in the raw material phenol.

8. (i) obtaining ortho,para-bisphenol A, ortho,ortho-bisphenol A, and / or para,para-bisphenol A according to the method 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 method for making a polycarbonate comprising: