JP4485178B2 - Method for producing bisphenols - Google Patents

Description

  The present invention relates to a method for producing bisphenol F useful as a resin raw material.

  Bisphenols produced by the reaction of monophenols and formaldehydes, such as bis (hydroxyphenyl) methanes (hereinafter referred to as bisphenol F), have a lower viscosity and heat resistance than so-called bis-A type epoxy resins made from bisphenol A. In addition to providing an excellent epoxy resin, it is also used as a curing agent for epoxy resins and a phenol resin modifier, and is attracting attention. Among them, for epoxy resin applications, further improvement in viscosity and heat resistance is strongly desired as needs are diversified.

  In general, bisphenol F is produced by a condensation reaction of phenol and formaldehyde using an acidic catalyst, for example, oxalic acid as a catalyst. In the produced bisphenol F, 4,4′-bisphenol F, 2,4′-bisphenol F is produced. In addition to the three isomers (binuclear) of 2,2'-bisphenol F, various heavy substances including trinuclear bodies, which are further polycondensed with phenol after addition of formaldehyde, are included. It is. Epoxy resins obtained by epoxidizing bisphenol F containing these heavy substances have a high viscosity and greatly deteriorate the low viscosity characteristic of bisphenol F epoxy. It is also reported that paints containing bisphenol F epoxy resins containing heavy materials are inferior to paints containing high-purity bisphenol F epoxy resins in terms of corrosion resistance, chemical resistance, etc. (JP-A-2-166114).

  Therefore, in the production of bisphenol F, various methods for suppressing the formation of heavy substances have been studied. For example, currently used bisphenol F having a purity of 90 to 94% has a phenol / formaldehyde molar ratio of 30 to 40 which is 15 times or more of the theoretical molar ratio in the homogeneous reaction system using the oxalic acid catalyst. Therefore, a long time and operating cost are required to distill and recover excess phenol after the reaction is completed, and the pot productivity is very low, 10% or less.

  The following Patent Document 1 describes a method for obtaining bisphenol F having a purity of 88% by using a large amount of 85% high-concentration phosphoric acid, a phenol / formaldehyde molar ratio of about 5, and a reaction temperature of 45 ° C. ing. Patent Document 2 mainly uses a large amount of an organic solvent such as toluene, a catalyst such as water and oxalic acid, a low-molar ratio of phenol / formaldehyde, a liquid phase mainly composed of toluene and the like, water, oxalic acid, and the like. A method is disclosed in which a reaction is carried out in a liquid-liquid heterogeneous system with stirring with a liquid phase to be obtained, and after the reaction, an organic solvent such as toluene and phenol are recovered by distillation to obtain bisphenol F. Furthermore, in Patent Document 3, 50 to 80% phosphoric acid water is used as a catalyst, raw material aldehyde is added sequentially, and the produced bisphenol F is rapidly extracted into the phenol phase, thereby suppressing heavy by-products. A method has been proposed. However, in any case, no method has been provided that satisfies both productivity and quality.

Japanese Examined Patent Publication No. 3-72049 Japanese Patent Laid-Open No. 6-135872 JP 09-67287 A JP 2002-346355 A Japanese translation of PCT publication No. 2002-512272

  By the way, although the micromixer which has two or more microchannels and a mixing space or a mixing area | region is known by the said patent documents 4-5 etc., there is nothing which teaches that this is suitable as a manufacturing apparatus of bisphenol F.

  An object of the present invention is to provide a production method capable of improving the purity of bisphenol F to be produced while also having excellent productivity without significantly increasing the phenol / formaldehyde molar ratio.

  As a result of intensive studies in view of the above circumstances, the present inventors have produced hydroxybenzyl alcohol by reacting phenol and formaldehyde in the presence of a base catalyst, and then include a first liquid containing this component and an acidic catalyst. It has been found that by supplying the second liquid into the mixing space in a layer form from a micro flow channel having a width of 1 to 300 μm, the hydroxybenzyl alcohol can be reacted efficiently and quickly, and the production ratio of heavy substances can be reduced. Completed the invention.

That is, the present invention includes a hydroxybenzyl alcohol produced by reacting phenol and formaldehyde with a molar ratio of phenols / formaldehyde of 2 to 30 and a reaction temperature of 30 to 60 ° C. in the presence of a base catalyst. A liquid and a second liquid containing an acid catalyst are separately supplied to a mixing space from a plurality of micro flow channels having a width of 1 to 300 μm, and reacted under acidic conditions at a reaction temperature of 50 to 170 ° C. This is a method for producing bis (hydroxyphenyl) methanes.

  As reaction conditions, the first liquid is preferably a liquid containing hydroxybenzyl alcohol obtained by reacting at a molar ratio of phenols / formaldehydes of 2 to 30, and the reaction temperature under a base catalyst is 30 to 30. It is desirable that the reaction temperature under an acid catalyst is 50 to 170 ° C. at 60 ° C. It is also desirable that the reaction product under a base catalyst is continuously subjected to an acid catalyst reaction with a rapid temperature change.

  As the reaction apparatus, the number of microchannels is 10 to 1000, microchannels to which the first liquid and the second liquid are supplied are alternately or randomly arranged, and hydroxybenzyl alcohol is mixed from the microchannels to the mixing space. And an acid catalyst are supplied, and an apparatus having a structure in which the catalyst is rapidly and uniformly mixed is desirable. For example, a micromixer having such a structure is preferably exemplified.

Hereinafter, the reaction conditions of the present invention will be described.
The reaction raw materials are phenol and formaldehyde. Hydroxybenzyl alcohol is produced from the reaction raw material using a base catalyst, and bisphenol F is produced from a liquid containing hydroxybenzyl alcohol using an acidic catalyst. Hereinafter, the reaction for generating hydroxybenzyl alcohol is sometimes referred to as a first reaction, and the reaction for generating bisphenol F is sometimes referred to as a second reaction.

  Phenol that produces bisphenol F is preferred as the phenol, but mono- and di-substituted phenols can also be used in small amounts together with phenol for the purpose of controlling heat resistance and other physical properties. Preferred examples of the substituted phenol include lower alkyl-substituted phenols such as cresol and xylenol.

Examples of formaldehydes include formaldehyde, paraformaldehyde, trioxane, and tetraoxane that generate formaldehyde in the reaction system and formaldehyde. Paraformaldehyde is preferred.
As described above, the phenol and formaldehyde referred to in the present invention may include derivatives thereof. However, in order to facilitate understanding, the phenols and formaldehyde are referred to as phenol and formaldehyde within a range not causing misunderstanding.

  The basic catalyst used in the first reaction is more basic than phenols such as metal hydroxides such as sodium hydroxide and potassium hydroxide, metal alkoxides such as sodium methoxide, sodium ethoxide and potassium tert-butoxy. High metal bases are preferred. Of these, metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred.

  The molar ratio of phenol / formaldehyde used for the first reaction is 2-30, preferably 5-15. When this molar ratio exceeds 30, the productivity is greatly reduced, which is not economical. The molar ratio 2 is a stoichiometric ratio, but in the range of 2 to 5, the conversion of formaldehyde in the base-catalyzed reaction does not end depending on conditions, and reacts with phenol in the subsequent acid-catalyzed reaction. The content (dinuclear body / binuclear body + polynuclear body of trinuclear body or higher) may be low. In the range of 5 to 15, a bisphenol having a high binuclear content can be more efficiently produced.

  In the first reaction, formaldehyde and phenol are reacted in the presence of a base catalyst. The raw material phenol can be used as a molten phenol solution as it is or in a solution state using various solvents. The solvent is not particularly limited as long as it suitably dissolves phenol and catalyst, but aromatic hydrocarbons such as toluene and xylene, ethers such as 1,4-dioxane and diphenyl ether, and benzonitrile are preferable.

  The base catalyzed reaction which is the first reaction is 30 to 60 ° C, preferably 40 to 50 ° C. At 60 ° C. or higher, formaldehyde reacts with two or more phenols to form bis or tris- (hydroxymethyl) -phenol, which in turn causes heavy products in the acid-catalyzed second reaction. On the other hand, if the temperature is lower than 30 ° C., the reaction does not proceed sufficiently and it takes a long time, but unreacted formaldehyde reacts with phenols in a second order in the second reaction to produce a heavy product.

  In the first reaction, it is preferable to react 90% or more of formaldehyde, preferably 99% or more. However, a large amount of phenol added excessively may remain unreacted. After completion of the first reaction, the produced hydroxybenzyl alcohol may be separated and concentrated, but it is convenient to use the solution for the second reaction with a solvent, unreacted phenol, catalyst and the like.

  In the second reaction, the first liquid containing hydroxybenzyl alcohol obtained in the first reaction and the second liquid containing an acid catalyst are reacted under acidic conditions. The first liquid is a liquid containing hydroxybenzyl alcohol, and can be a liquid obtained by concentrating or separating the hydroxybenzyl alcohol obtained in the first reaction or a liquid obtained by adding a solvent to the liquid. The reaction mixture containing the hydroxybenzyl alcohol obtained in the first reaction is advantageous. In addition, you may mix | blend a solvent, phenol, etc. with this reaction liquid mixture as needed. The second liquid is a liquid containing an acid catalyst, and if necessary, a solvent such as water or an organic solvent, phenol or the like may be blended.

  Examples of the acid catalyst include inorganic mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid, heteropolyacids such as phosphotungstic acid, phosphomolybdic acid and phosphomolybdotungstic acid, metal halide salts such as zinc chloride and aluminum chloride, trichloroacetic acid, Halogenated carboxylic acids such as dichloroacetic acid, aromatic sulfonic acids, formic acid, and oxalic acid can be mentioned, among which oxalic acid, inorganic mineral acids, and aromatic sulfonic acids are preferred. When the first liquid contains a base catalyst, the acid catalyst is used in an amount sufficient to neutralize the acid catalyst and make the whole acidic.

  In the second reaction, the first liquid containing hydroxybenzyl alcohol and the second liquid containing an acid catalyst are mixed through a plurality of microchannels, and the reaction is performed under acidic conditions. The temperature in this reaction is 50 to 170 ° C, preferably 80 to 140 ° C. Below 50 ° C., the reaction does not proceed sufficiently, the reaction does not end in the mixing space, and it becomes necessary to prepare a reaction space following the mixing space. Further, when the temperature exceeds 170 ° C., the quality is deteriorated due to coloring of the product, and there is a concern that the product is blocked in the mixed space due to partial vaporization of the solvent and unreacted phenol. The reaction time is adjusted so that 90% or more, preferably 99% or more of the hydroxybenzyl alcohol is reacted.

  Here, it is desirable to supply the first liquid to the second reaction promptly. In particular, when the first liquid containing the base catalyst is heated to a temperature of 60 ° C. or higher before being mixed with the second liquid, hydroxybenzyl alcohol condenses with each other to form a crosslinked heavy product. To do. Therefore, when the first liquid is continuously mixed with the second liquid, it is preferable that the first liquid is rapidly heated to the second reaction temperature and supplied to the second reaction quickly. For this purpose, it is desirable to rapidly heat to the second reaction temperature via a micro heat exchanger having high heat exchange efficiency, for example, and send the solution to the mixing space where the second reaction occurs.

Next, a reaction apparatus used in the second reaction, preferably a micromixer will be described.
Since it is important to perform the second reaction rapidly, an apparatus in which the first liquid and the second liquid are mixed rapidly is used. Such an apparatus has a plurality of microchannels having a width of 1 to 300 μm, preferably 10 to 200 μm, and a mixing space for mixing the liquid supplied from the microchannels. The height of the microchannel is appropriately about 1 to 300 μm, and the length of the channel is not limited, but about 1 to 200 mm is appropriate. The raw material liquid containing the catalyst supplied from the micro flow path is rapidly and uniformly mixed in the mixing space to cause a reaction. The volume of the mixing space is adjusted so as to obtain a predetermined residence time.

  Preferably, a plurality of layered raw material liquids are supplied from a plurality of microchannels to the mixing space, and in the mixing space, the two liquids are mixed so as to be positioned alternately. For example, a plurality of microfluidic channels for the first and second liquids are provided, and the microfluidic channels for the first and second liquids are alternately provided in parallel in the width direction, the vertical direction, or the width and the vertical direction. Thus, there is a method of accelerating the mixing in the mixing space by causing the B liquid to flow adjacent to the A liquid and the A liquid to flow adjacent thereto. In this case, the mixing space is provided so that the flow merges so that the flow of the first liquid and the second liquid is uniformly mixed at the inlet portion, and is cut in a direction substantially perpendicular to the flow direction, It is desirable to provide a slit having a length equal to or greater than the width of the blister flow. When passing through the slit, the first liquid and the second liquid are rapidly and uniformly mixed, flow into the mixing space, further mixed, and a reaction occurs. In this mixing space, it is preferable that the vicinity of the inlet portion has a width approximate to that of the micro flow path. Accordingly, the mixing space may be only the slit portion, or may have a space that also serves as the reaction space if the reaction time is long. The mixing space referred to in the present invention may be a space including at least a slit portion, and may additionally have a reaction space used only for the reaction. That is, in the case of the micromixer, the mixing space including the slit portion is provided in the micromixer, but the reaction space may be provided outside the micromixer. However, when the reaction is completed in the micromixer, it is not necessary to provide a reaction space outside the micromixer.

  The micromixer is typified by an interdigital type mixing method using the LIGA Micromixing System (Micromixer) manufactured by IMM, Germany. However, the present invention is not limited to a device called a micromixer, and may be applied to other devices. Can be implemented.

An example of a micromixer preferably used in the reaction of the present invention will be described with reference to FIGS.
1 to 3 show a plurality of micro-channel type micromixers 20, FIG. 1 shows an assembly diagram of the micromixer, FIG. 2 shows an enlarged schematic view, and FIG. 3 shows an enlarged plan view of the micro-channels. Show.
In FIG. 1, the upper body 4 has a raw material liquid A inlet portion 7, a raw material liquid B inlet portion 9, a reaction mixture outlet portion 8 and a slit 10. The intermediate member 5 has a large number of micro flow channels 11, one end of which is connected to the raw material liquid A inlet portion 7, and the other end is connected to the raw material liquid B inlet portion 9, and is integrated with the upper body 4 and the lower body 6. By doing so, the micromixer 20 is configured. Respective raw material liquids flowing from both ends of the microchannel 11 merge at the intermediate part, and have a slit 10 at the inlet and are sent to a mixing space having a predetermined volume to cause a reaction. This mixing space is provided in the micromixer 20, where mixing and reaction occur. When the reaction is insufficient, a reaction space is provided by connecting to the reaction mixture outlet 8.

  2 and 3, fluid A (first liquid) flows through the plurality of microchannels 23, fluid B (second liquid) flows through the plurality of microchannels 22, and is disposed substantially perpendicular to the flow direction. It passes through a slit 10 having a length approximately equal to the flow width. The fluids A and B are alternately layered at the entrance of the slit, but at the exit of the slit, mixing of these proceeds and the subsequent mixing space (which may be a tube or space constituting the reaction mixture outlet 8). Mixing) is complete. In the figure, the number of microchannels is reduced for the sake of clarity, but if the width of the microchannels is reduced and the number is increased, mixing is promoted, so 10 or more, preferably 100 or more are provided. Good.

  In addition to the reaction apparatus described above, various reaction apparatuses or micromixers known in Patent Documents 4 to 5 can be used.

  As a conventional reaction apparatus, there is a T-shaped mixer as shown in FIG. This mixer has microchannels 1 and 2, the first liquid is supplied from microchannel 1, the second liquid is supplied from microchannel 2, and uniform in microchannel 3, which is a mixing space. To produce a reaction. A reaction space may be provided following this mixing space. In the case of such a single-channel mixer, it is necessary to increase the width of the micro-channel in order to secure the reaction production amount, and it is usually 0.5 mm or more.

  The raw material liquids of the first liquid and the second liquid are supplied at a flow rate sufficient to alternately form layers. For example, in the case of the above-mentioned IMM Micromixer, each solution is preferably 0.5 to 10 ml / min, more preferably 1 to 5 ml / min. Since both liquids are preferably mixed at the same flow rate, when the raw material molar ratios are different, it is preferable to dilute one with a solvent, increase the dilution ratio, or mix phenol. .

  After completion of the reaction, bisphenol having a high binuclear content can be easily obtained by removing the solvent, unreacted phenol, catalyst and the like by conventional methods (eg, distillation, extraction, etc.).

  According to the present invention, it has excellent productivity without increasing the molar ratio of phenol and formaldehyde, and the purity of bisphenol F produced can be improved. Moreover, when obtaining the same dinuclear content rate, the molar ratio of formaldehyde can be raised and productivity can be improved.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The analysis was performed using a high performance liquid chromatograph. Further,% is% by weight unless otherwise specified.

Example 1
A mixture of 20 g of phenol and 20 g of 1,4-dioxane and 0.9 g of paraformaldehyde were added to a 100 ml eggplant flask and heated and stirred in a 50 ° C. water bath to dissolve paraformaldehyde. Further, 0.5 ml of 2N aqueous sodium hydroxide solution was added and stirred for 2 hours to complete the reaction and obtain liquid A. As a result of analysis, the formaldehyde conversion was 99.1%, and the yields of o-hydroxybenzyl alcohol and p-hydroxybenzyl alcohol were 71.0% and 27.2%, respectively.
Similarly, 0.76 g of paratoluenesulfonic acid monohydrate is added to a mixed solution of 20 g of phenol and 20 g of 1,4-dioxane, and heated and stirred in a water bath at 80 ° C. to dissolve paratoluenesulfonic acid monohydrate. This was designated as B liquid.
After sufficiently cooling both A and B liquids, it was filtered through a 0.45 μm membrane filter to obtain a raw material liquid. Micromixer manufactured by IMM was immersed in an oil bath, and the raw material liquids A and B were fed at 1.5 ml / min. A 30 cm long Teflon (registered trademark) tube (outer diameter 1.6 mm, inner diameter 1.0 mm) equipment was immersed in the same oil bath at the rear of the outlet of the Micromixer to serve as an auxiliary part of the reaction space. The micromixer internal microchannel width is 40 μm, the number of channels is 30 (15 per fluid), the slit width is 60 μm, the length is 4 mm, and the mixing unit volume in the mixer is 0.038 cc including the slit outlet. The reaction temperature was 90 ° C. The product was rapidly cooled to stop the reaction and then analyzed. The bisphenol F yield and the binuclear content are shown in Table 1. Note that FIGS. 1 to 3 are referred to for the structure of the Micromixer.

Example 2
All reactions were the same as in Example 1 except that the temperature of the oil bath in which the Micromixer was immersed was 130 ° C. The analysis results are shown in Table 1.

Comparative Example 1
A 100 ml eggplant flask was mixed with 20 g of phenol and 20 g of 1,4-dioxane and 0.9 g of paraformaldehyde, and heated and stirred in a 50 ° C. water bath to dissolve paraformaldehyde. Furthermore, 0.5 ml of 2N sodium hydroxide aqueous solution was added and stirred for 2 hours to complete the reaction. To this was added a mixed solution of 20 g of phenol in which 0.76 g of paratoluenesulfonic acid monohydrate was dissolved and 20 g of 1,4-dioxane, and the mixture was heated and stirred in an oil bath for 2 hours to complete the reaction. The reaction temperature was 90 ° C. The analysis results of the product are shown in Table 2.

Comparative Example 2
The same reaction as in Example 1 was performed except that instead of the Micromixer, a PEEK T-shaped channel mixer as shown in FIG. 4 having a channel width of 800 μm was used. The analysis results are shown in Table 2.

Comparative Example 3
Using a Micromixer equipped with a preheating part spirally wound with a 50 cm stainless pipe (outer diameter 1.6 mm, inner diameter 1.0 mm) on the upstream side of the entrance, with the preheating part and Micromixer immersed in an oil bath, The same reaction as in Example 1 was performed. The analysis results are shown in Table 2.

Comparative Example 4
A 100 ml eggplant flask was mixed with 20 g of phenol and 20 g of 1,4-dioxane and 0.9 g of paraformaldehyde, and heated and stirred in an 80 ° C. water bath to dissolve paraformaldehyde. Furthermore, 0.5 ml of 2N sodium hydroxide aqueous solution was added and stirred for 2 hours to complete the reaction. The analysis results are shown in Table 3.

Assembly drawing of micromixer Magnified schematic diagram of a micromixer Expanded plan view of micromixer Schematic diagram of a conventional mixer

Explanation of symbols

  4: upper body, 5: intermediate member, 6: lower body, 7, 9: inlet, 8: reaction mixture outlet, 10: slit, 11: microchannel, 20: micromixer, 22, 23: microflow Road

Claims (6)

A first liquid containing hydroxybenzyl alcohol produced by reacting phenol and formaldehyde with a phenol / formaldehyde molar ratio of 2 to 30 and a reaction temperature of 30 to 60 ° C. in the presence of a base catalyst, and an acid catalyst The bis (hydroxyphenyl) methane, wherein the second liquid is separately supplied to the mixing space from a plurality of micro flow channels having a width of 1 to 300 μm and reacted under acidic conditions at a reaction temperature of 50 to 170 ° C. Manufacturing method. The method for producing bis (hydroxyphenyl) methanes according to claim 1, wherein the first liquid is a liquid containing hydroxybenzyl alcohol obtained by reacting at a molar ratio of phenols / formaldehydes of 5 to 15 . The method for producing bis (hydroxyphenyl) methanes according to claim 1 or 2, wherein the reaction temperature in the presence of a base catalyst is 40 to 50 ° C , and the reaction temperature under acidic conditions is 80 to 140 ° C. The method for producing bis (hydroxyphenyl) methanes according to claim 1, 2 or 3, wherein the reaction product in the presence of a base catalyst is continuously subjected to a reaction under acidic conditions. The number of microchannels is 10 to 1000, the microchannels to which the first liquid and the second liquid are supplied are alternately or randomly arranged, and hydroxybenzyl alcohol and the acid catalyst are supplied from this microchannel to the mixing space The method for producing bis (hydroxyphenyl) methanes according to claim 1, wherein the bis (hydroxyphenyl) methanes are configured to be uniformly mixed.   The method for producing bis (hydroxyphenyl) methanes according to any one of claims 1 to 5, wherein the apparatus having a microchannel and a mixing space is a micromixer.

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