JP5994352B2 - Method for producing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt - Google Patents

Description

  The present invention provides an industrial process for producing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salts.

  2,2-bis (4-hydroxyphenyl) hexafluoropropane [in this specification, sometimes referred to as “BIS-AF”. ] Is an important substance as an intermediate for fluororubber crosslinking agents, functional polymers and pharmaceuticals and agrochemicals, but the quaternary phosphonium salt of propane has excellent performance as a vulcanization accelerator for fluorine-containing elastomers. It has been known. For example, in Patent Document 1, as a fluoroelastomer vulcanized compound, (a) a fluorine-containing elastomer, (b) a divalent metal oxide, hydroxide, or a mixture of these divalent metal compound and weak acid metal salt, And (c) 4 of 2,2-bis (4-hydroxyphenyl) hexafluoropropane as “active hydrogen-containing aromatic compound—fourth phosphonium salt” for a vulcanized compound containing a polyhydroxy aromatic compound. It is disclosed that the properties of the vulcanizate, such as hardness, 100% modulus, stress at break, and elongation at break, are improved by adding a grade phosphonium salt. Among these, the molar ratio of 2,2-bis (4-hydroxyphenyl) hexafluoropropane and quaternary phosphonium salt is about 0.5 to 2, and a polar organic solvent (such as isopropyl alcohol) or a carbonyl group It is disclosed to react in a containing organic solvent.

  In Patent Document 2, 2,2-bis (4-hydroxyphenyl) hexafluoropropane is reacted with an alkali metal alkoxide in a methanol solvent to form an alkali metal salt of the propane, and then reacted with a quaternary phosphonium salt. To produce a 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt.

  In this specification, the quaternary phosphonium salt of 2,2-bis (4-hydroxyphenyl) hexafluoropropane is referred to as “2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt”. May represent.

Japanese Examined Patent Publication No. 59-023577 JP-A-11-147891

  According to the methods described in Patent Document 1 and Patent Document 2, the desired 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt can be produced. However, in this method, since methanol is used as a solvent, it can be obtained as a methanol solution even after the reaction, but the target 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is obtained. For example, in order to use with a vulcanization accelerator, it is necessary to take it out as a crystal. Actually, in Patent Document 1, in order to take out the target 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt as crystals, concentration operation by distilling off the solvent, followed by dripping into a large amount of water In this way, crystals are precipitated, and separated and dried to obtain crystals, so that a large number of steps are required for taking out the target product as crystals.

  Furthermore, in Patent Document 2, 2,2-bis (4-hydroxyphenyl) hexafluoropropane is added to the reaction system in two stages. It was large and not necessarily an advantageous production method.

  An object of the present invention is to establish a production method for 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt on an industrial scale and superior in production cost, safety and simplicity. Is an issue.

  As a result of intensive studies to solve the above problems, the present inventors have unexpectedly found that a target product can be synthesized by reacting with water as a solvent.

  In addition, after the reaction, it was also found that the target crystals can be obtained simply and in high yield by simply separating and drying, and the present invention has been completed.

  That is, the present invention provides a method for producing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt described in [Invention 1] to [Invention 7] below.

[Invention 1]
2,2-bis (4-hydroxyphenyl) hexafluoropropane is reacted with an alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate in the presence of water to give 2,2-bis (4-hydroxyphenyl). 2) A 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt, characterized by reacting a quaternary phosphonium salt with the alkali metal salt of hexafluoropropane. Manufacturing method.

[Invention 2]
The reaction is carried out with 0.5 mol of alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate with respect to 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
And reacting with 0.5 moles of a quaternary phosphonium salt.

[Invention 3]
The molar ratio of 2,2-bis (4-hydroxyphenyl) hexafluoropropane to quaternary phosphonium salt in 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is 2,2-bis ( 4-Hydroxyphenyl) hexafluoropropane: quaternary phosphonium salt = 2: 1 The process according to Invention 1 or 2.

[Invention 4]
The reaction is carried out by adding 0.25 mol of alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate to 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
And reacting with 0.25 mole of quaternary phosphonium salt.

[Invention 5]
The molar ratio of 2,2-bis (4-hydroxyphenyl) hexafluoropropane to quaternary phosphonium salt in 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is 2,2-bis ( 4-Hydroxyphenyl) hexafluoropropane: quaternary phosphonium salt = 4: 1.

[Invention 6]
6. The method according to any one of inventions 1 to 5, wherein an alkali metal hydrogen carbonate, an alkali metal phosphate, or an alkali metal carboxylate is further added to the reaction system.

[Invention 7]
The method according to any one of inventions 1 to 6, further comprising a step of filtering out a mixture containing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt obtained after the reaction and impurities and separating the impurities. The method in any one.

  According to the present invention, since water is used as a solvent, 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt can be produced without burdening the treatment of the waste liquid. Further, compared to Patent Document 2, it is not necessary to add 2,2-bis (4-hydroxyphenyl) hexafluoropropane to the reaction system in two portions, the reaction process can be simplified, and the obtained phosphonium Excellent in efficiently producing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt on an industrial scale, such as the point that impurities can be easily separated simply by filtration. It is a method.

  The production method of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt of the present invention will be described in detail.

  The scope of the present invention is not limited to these explanations, and other than the following examples, the scope of the present invention can be changed and implemented as appropriate without departing from the spirit of the present invention. In addition, all publications cited in this specification, for example, prior art documents, and publications, patent publications and other patent documents are incorporated herein by reference.

  In the present invention, water and 2,2-bis (4-hydroxyphenyl) hexafluoropropane are charged in a reaction system and stirred to obtain a uniform slurry liquid (suspension). An alkali metal hydroxide, an alkali metal alkoxide, or an alkali metal carbonate, and an alkali metal hydrogen carbonate, an alkali metal phosphate, or an alkali metal carboxylate as necessary are added, An alkali metal salt of bis (4-hydroxyphenyl) hexafluoropropane is produced. Next, an aqueous quaternary phosphonium salt solution is dropped, and an aqueous slurry liquid of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is produced through an aging reaction.

  2,2-bis (4-hydroxyphenyl) hexafluoropropane used in the present invention can be produced by a known production method. For example, it is produced by reacting hexafluoroacetone and phenol in the presence of an organic acid such as toluenesulfonic acid or trifluoromethanesulfonic acid (US Pat. No. 4,400,466), or hexafluoroacetone and phenol are fluorinated. Reaction with hydrogen (Izv Akad Nauk SSSR Otd Khim Nauk vol. 4 pp. 686-692 (1960); English version pp. 647-653, JP 7-126200 A, or JP 2010-275295 A) Any method can be adopted.

  As the reactor used in the present invention, a reaction vessel equipped with a stirrer lined with stainless steel, glass, glass, fluororesin or the like can be used.

  The present invention uses water as a solvent. The amount of water added to the reaction system is preferably 10 to 20% by mass relative to 2,2-bis (4-hydroxyphenyl) hexafluoropropane. If it is less than 10% by mass, it may cause malfunctions such as poor stirring and poor extraction. On the other hand, when the amount is more than 20% by mass, there is no particular problem. However, since the production amount per reaction decreases and the productivity may be lowered, it is preferably added to the reaction system in the above range.

  The types of alkali metal hydroxide, alkali metal alkoxide, and alkali metal carbonate used to produce the alkali salt of 2,2-bis (4-hydroxyphenyl) hexafluoropropane include sodium hydroxide, hydroxide Use potassium, lithium hydroxide, sodium methoxide, potassium methoxide, lithium methoxide, sodium ethoxide, potassium ethoxide, lithium ethoxide, sodium butoxide, potassium butoxide, lithium butoxide, sodium carbonate, potassium carbonate, lithium carbonate, etc. It is done. Moreover, although there is no problem even if these are used in a solid state, it is preferable to add them little by little in order to uniformly react and to adjust the temperature due to heat generation. From this, it is preferable to use them as a solution. As the solution, an alcohol solution such as methanol or ethanol, or an aqueous solution is used. However, the aqueous solution is preferably used, and the concentration of the aqueous solution is preferably 5 to 15% by mass. If it exceeds 15% by mass (dense), it may cause operational problems such as generation of insoluble matter. On the other hand, if it is less than 5% by mass (even if it is thin), there is no particular problem, but the slurry concentration becomes low and production occurs. It may reduce the sex.

  The present invention is a method for producing 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt, and 2,2-bis (4-hydroxyphenyl) hexafluoropropane, quaternary phosphonium salt, 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salts having different molar ratios can be produced in a shorter process and more efficiently than the aforementioned Patent Document 1-2.

  As a preferred embodiment of the present invention, for example, when an alkali metal hydroxide is used, the propane: quaternary phosphonium salt = 2: 1 salt of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium. Is used, 0.5 mol of alkali metal hydroxide is used per 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane (corresponding to [Invention 2]-[Invention 3] described above) In the production of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium propane: quaternary phosphonium salt = 4: 1, 2,2-bis (4-hydroxyphenyl) By using 0.25 mol of alkali metal hydroxide per 1 mol of hexafluoropropane (corresponding to [Invention 4]-[Invention 5] described above) The different target product can be favorably manufactured. Details of the quaternary phosphonium salt are described below.

  The quaternary phosphonium salt used in the present invention includes tetraphenylphosphonium chloride, triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, 3,4-dichlorobenzyltriphenylphosphonium chloride, 1- (prop-2-one-yl). -Triphenylphosphonium chloride, (ethoxycarbonylmethyl) triphenylphosphonium chloride, allyltriphenylphosphonium chloride, allyltriphenylphosphonium bromide, tetramethylphosphonium chloride, tetramethylphosphonium bromide, tetraethylphosphonium chloride, tetraethylphosphonium bromide Of these, a triphenylbenzylphosphonium salt (of course, a hydrogen atom on the phenyl group) Some halogen atom (chlorine atom, bromine atom) also include those substituted in) are used. These quaternary phosphonium salts may be used in a solid state, but it is preferable to add them little by little in order to cause a uniform reaction. Further, it is preferably used as a solution state in terms of operation, and used as an alcohol solution or an aqueous solution such as methanol or ethanol, preferably an aqueous solution. The concentration of the aqueous solution of the quaternary phosphonium salt to be used is preferably 5 to 10% by mass, and if it is higher than 10% by mass, it causes operational problems such as generation of insoluble matter. Although there is no problem, the slurry concentration becomes thin and the productivity is lowered.

  The amount of the quaternary phosphonium salt to be used is appropriately adjusted to a preferred ratio according to the molar ratio of the propane to the quaternary phosphonium salt of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium to be produced. Can be adjusted. For example, when producing the above-mentioned salt of propane: quaternary phosphonium salt of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium = 2: 1, 2,2-bis (4-hydroxy (Phenyl) 0.5 mol of quaternary phosphonium salt is used per 1 mol of hexafluoropropane (corresponding to [Invention 2]-[Invention 3] described above), while propane: quaternary phosphonium salt = 4: 1. In the case of producing a salt, 0.25 mol of quaternary phosphonium salt is used per 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane (corresponding to [Invention 4] to [Invention 5] described above). Therefore, it is possible to satisfactorily produce objects having different molar ratios.

In the present invention, an alkali metal hydrogen carbonate, an alkali metal phosphate, or an alkali metal carboxylate can coexist in the reaction system. The addition of these has the effect of suppressing the generation of triphenylphosphine oxide [(C ₆ H ₅ ) ₃ P (═O)], which is a by-product derived from a quaternary phosphonium salt, in the reaction system. It is desirable to do. Specific types of alkali metal bicarbonate, alkali metal phosphate, and alkali metal carboxylate include sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, disodium phosphate, dipotassium phosphate, phosphoric acid Examples thereof include sodium, potassium phosphate, sodium acetate, and potassium acetate. Among these, sodium hydrogen carbonate is particularly easily available and is preferably used. Further, the addition amount is preferably 5 to 20 mol% with respect to 2,2-bis (4-hydroxyphenyl) hexafluoropropane. If the amount is less than 5 mol%, no effect is observed. On the other hand, if the amount is added more than 20 mol%, the effect is the same.

  The reaction time required for the reaction in the present invention to proceed sufficiently is 3 to 15 hours after the addition of the quaternary phosphonium salt. If the time is shorter than this time, a portion that does not become a stable salt may be formed. On the other hand, if the time is longer than this time, the effect is the same, and the productivity may be lowered by taking a long time.

  The 2,2-bis (4-hydroxyphenyl) hexafluoropropane-4 quaternary phosphonium salt slurry obtained by the above method was filtered to obtain 2,2-bis (4-hydroxyphenyl) hexafluoropropane-4. A crystal of a quaternary phosphonium salt is taken out. Thereafter, by drying, a 2,2-bis (4-hydroxyphenyl) hexafluoropropane quaternary phosphonium salt that can be used as a vulcanization accelerator for a fluorine-containing elastomer is produced.

  The filtering operation at this time (also referred to as “filtering operation”) will be described.

  In the present invention, the 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt contains many impurities such as inorganic substances such as alkali metals and halides in addition to the target substance. Although obtained as a state, the obtained target product can be easily separated from impurities by a normal filtration operation.

  Examples of the filtration method include vacuum filtration, pressure filtration, and centrifugal separation, but the method is not limited. In order to remove impurities adhering to the crystals at the time of filtration and separation, it is preferable to wash with water. The amount of water used for washing is 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt. An amount of 1 to 3 times the theoretical recovered weight is preferred. If the amount is less than this amount, the attached impurities may not be removed. On the other hand, if the amount is greater than this amount, there is no problem, but no further effect is observed, and the amount of wastewater increases and wastewater treatment costs increase. May cause disadvantages.

  When drying the target product obtained after filtration, the drying equipment used for drying includes a vacuum stationary dryer, a vacuum vibration dryer, a vacuum conical dryer, a vacuum nauter dryer, etc. There are no particular restrictions. Drying is carried out under reduced pressure. Since the water-containing crystals may melt when dried at a high temperature from the beginning, it is preferable to start at a low temperature of 40 ° C. and gradually increase the temperature to 60 ° C. at the initial stage of drying. Although there are no particular rules for the temperature raising method, it is preferable to raise the temperature so that the crystals are not melted under reduced pressure (for details, see Examples).

[Example]
Embodiments of the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

In the specification, benzyltriphenylphosphonium may be represented as “BTP” and benzyltriphenylphosphonium chloride may be represented as “BTPCl”.

  A 1 L four-necked flask equipped with a Dimroth tube and a thermometer was charged with BIS-AF: 50.0 g (0.149 mol) and water: 345.5 g, and the internal temperature was raised to 40 ° C. while stirring, and 5 wt% water. Add 30.3 g (0.038 mol) of an aqueous sodium oxide solution and stir for 30 minutes to form a slurry of BIS-AF 0.25Na salt. Next, 7 wt% BTPCl aqueous solution: 210.7 g (0.038 mol) was added dropwise at a rate of 3 to 4 g / min, stirred for 3 hours, and 2,2-bis (4-hydroxyphenyl) hexafluoropropane-benzyltri A slurry of phenylphosphonium 4: 1 salt was obtained.

  Subsequently, a slurry of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-benzyltriphenylphosphonium 4: 1 salt was collected by filtration, and the collected solid was washed with 570.0 g of water to obtain 1333 pa. 1 hour 30 minutes at a temperature of 40 ° C, 1333pa, 1 hour at a temperature of 45 ° C, 1333pa, 2 hours at a temperature of 50 ° C, 1333pa, 1 hour at a temperature of 60 ° C. The weight after drying was 60.3 g. As a result, the composition was analyzed by liquid chromatography. BIS-AF was 65.11% (79.68 mol%), BTP was 34.72% (20.32 mol%), and impurities derived from BTPCl, triphenylphosphine oxide The melting point was 100 to 118 ° C. (TG-DTA endothermic peak reading). The overall yield from BIS-AF was 95%.

  A 1 L four-necked flask equipped with a Dimroth tube and a thermometer was charged with BIS-AF: 50.0 g (0.149 mol) and water: 345.5 g, and the internal temperature was raised to 20 ° C. while stirring, and 5 wt% water. Add 30.3 g (0.038 mol) of an aqueous sodium oxide solution and stir for 30 minutes to form a slurry of BIS-AF 0.25Na salt. Next, 1.3 g of sodium bicarbonate was added, the internal temperature was raised to 40 ° C., and the mixture was stirred for 30 minutes, and then 7 wt% BTPCl aqueous solution: 210.7 g (0.038 mol) was added at a rate of 3 to 4 g / min. And stirred for 3 hours to obtain a slurry of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-benzyltriphenylphosphonium 4: 1 salt.

  Subsequently, a slurry of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-benzyltriphenylphosphonium 4: 1 salt was collected by filtration, and the collected solid was washed with 450.0 g of water to obtain 1333 pa. 1 hour 30 minutes at a temperature of 40 ° C, 1333pa, 1 hour at a temperature of 45 ° C, 1333pa, 2 hours at a temperature of 50 ° C, 1333pa, 1 hour at a temperature of 60 ° C. The weight after drying was 60.0 g. As a result, the composition was analyzed by liquid chromatography, BIS-AF was 64.91% (79.47 mol%), BTP was 35.08% (20.53 mol%), and impurities derived from BTPCl, triphenylphosphine oxide Was not detected, and the melting point was 116 to 118 ° C. (TG-DTA endothermic peak reading). The overall yield from BIS-AF was 95%.

A 1 L four-necked flask equipped with a Dimroth tube and a thermometer was charged with BIS-AF: 50.0 g (0.149 mol) and water: 520.9 g, and the internal temperature was raised to 20 ° C. while stirring to 5.7 wt. 52.2 g (0.074 mol) of an aqueous sodium hydroxide solution is added and stirred for 30 minutes to form a 0.5Na salt slurry of BIS-AF. Next, 2.5 g of sodium hydrogen carbonate was added, the internal temperature was raised to 40 ° C., and the mixture was stirred for 30 minutes. And stirred for 1 hour to obtain a slurry of 2,2-bis (4-hydroxyphenyl) hexafluoropropane-benzyltriphenylphosphonium 2: 1 salt, followed by 2,2-bis (4-hydroxy A slurry of a 2: 1 salt of (phenyl) hexafluoropropane-benzyltriphenylphosphonium was collected by filtration, and the collected solid was washed with 450.0 g of water, 1333 pa, temperature 40 ° C. for 1 hour 30 minutes, 1333 pa, It was dried at a temperature of 45 ° C. for 1 hour, 1333 pa, at a temperature of 50 ° C. for 2 hours, 1333 pa and a temperature of 60 ° C. for 1 hour. The weight after drying was 73.43g. As a result, the composition was analyzed by liquid chromatography. BIS-AF was 49.03% (66.71 mol%), BTP was 50.91% (33.29 mol%), and impurities derived from BTPCl were triphenylphosphine oxide. The melting point was 187 to 194 ° C. (TG-DTA endothermic peak reading). The overall yield from BIS-AF was 96%.

The 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt targeted in the present invention can be used as a vulcanization accelerator for a fluorine-containing elastomer.

Claims (6)

2,2-bis (4-hydroxyphenyl) hexafluoropropane is reacted with an alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate in the presence of water to give 2,2-bis (4-hydroxyphenyl). ) Hexafluoropropane alkali metal salt, the obtained alkali metal salt is reacted with a quaternary phosphonium salt , and an alkali metal bicarbonate, alkali metal phosphate, or alkali metal carboxylate is further added to the reaction system. Additionally characterized Rukoto, 2,2-bis (4-hydroxyphenyl) mETHOD hexafluoropropane -4 quaternary phosphonium salts. The reaction is carried out with 0.5 mol of alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate with respect to 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
And reacting with 0.5 mol of a quaternary phosphonium salt. The molar ratio of 2,2-bis (4-hydroxyphenyl) hexafluoropropane to quaternary phosphonium salt in 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is 2,2-bis ( The method according to claim 1 or 2, wherein 4-hydroxyphenyl) hexafluoropropane: quaternary phosphonium salt = 2: 1. The reaction is carried out by adding 0.25 mol of alkali metal hydroxide, alkali metal alkoxide, or alkali metal carbonate to 1 mol of 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
And reacting with 0.25 mol of quaternary phosphonium salt. The molar ratio of 2,2-bis (4-hydroxyphenyl) hexafluoropropane to quaternary phosphonium salt in 2,2-bis (4-hydroxyphenyl) hexafluoropropane-quaternary phosphonium salt is 2,2-bis ( The method according to claim 1 or 4, wherein 4-hydroxyphenyl) hexafluoropropane: quaternary phosphonium salt = 4: 1. Obtained after the reaction of 2,2-bis and (4-hydroxyphenyl) hexafluoropropane -4 quaternary phosphonium salt was filtered off a mixture containing impurities, further comprising the step of separating the impurities, according to claim 1 to 5 The method in any one of.