CN114555549A

CN114555549A - Powder, method for producing powder, and method for producing solution

Info

Publication number: CN114555549A
Application number: CN202080068632.5A
Authority: CN
Inventors: 细井健史; 渡边峰男
Original assignee: Central Glass Co Ltd
Current assignee: Central Glass Co Ltd
Priority date: 2019-09-30
Filing date: 2020-09-24
Publication date: 2022-05-27
Also published as: TW202120463A; KR20220069060A; WO2021065653A1; JPWO2021065653A1

Abstract

A powder of a compound represented by the general formula (A). For example, by excitation of the powderMode particle diameter D measured by light diffraction scattering method_m75 to 150 μm and less than 1ppm of Ca ion. In the general formula (A), R¹～R⁸Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom or an amino group. The powder can be obtained, for example, by a method comprising the steps of: (i) a melting step of melting a raw material substance including a compound represented by general formula (a) in the presence of an aqueous dispersion medium by placing the raw material substance and the aqueous dispersion medium (a poor solvent for the compound represented by general formula (a)) in a container and heating the raw material substance to obtain an inhomogeneous liquid; (ii) and a crystallization step of cooling the inhomogeneous liquid to crystallize the melt.

Description

Powder, method for producing powder, and method for producing solution

Technical Field

The present invention relates to a powder, a method for producing the powder, and a method for producing a solution. More specifically, the present invention relates to a powder of a fluorinated bisphenol compound represented by general formula (a) disclosed below, a method for producing the powder, and a method for producing a solution using the powder.

Background

Fluorinated bisphenol compounds represented by 2, 2-BIS (4-hydroxyphenyl) hexafluoropropane (hereinafter also abbreviated as "BIS-AF") are frequently used as a raw material for various resins and the like.

As an example, patent document 1 of a document relating to an epoxy resin composition describes: as production example 1, this white powder was obtained by crystallizing BIS-AF in a mixed solvent of ethylene glycol and pure water.

As another example, patent document 2 describes, for example: BIS-AF dissolved in an alkaline aqueous solution was precipitated by neutralization with hydrochloric acid to obtain a solid of BIS-AF in which hexafluoroacetone was reduced as an impurity.

As another example, patent document 3 discloses a purification method of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane, which comprises heating 2, 2-bis (4-hydroxyphenyl) hexafluoropropane and water to a temperature higher than room temperature, and cooling the solution (aqueous solution) to obtain a precipitated solid, in claims, examples and the like.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2007 and 246819

Patent document 2: japanese laid-open patent publication No. 4-054144

Patent document 3: japanese laid-open patent publication No. 2-067239

Disclosure of Invention

Problems to be solved by the invention

Fluorinated bisphenols such as BIS-AF are generally produced and sold industrially in the form of powder. In addition, the powder may be used in various industrial processes as it is.

According to the findings of the present inventors, there is room for improvement in the industrial operability of conventional powdery fluorinated bisphenols. "industrial operability" means, for example, 1 or 2 or more of the following items.

Good filterability

Drying time for drying wet powder is short

Not liable to absorb moisture

Good flowability of the powder

Good solubility in solvent, specifically, rapid dissolution in solvent

Less tendency to caking (caking)

The present invention has been made in view of such circumstances. An object of the present invention is to provide a powdery fluorinated bisphenol compound having excellent industrial operability.

Means for solving the problems

The present inventors have completed the following inventions 1 to 4.

The 1 st invention is as follows.

A powder of a compound represented by the following general formula (A),

mode particle diameter D measured by laser diffraction scattering method_mIs 75 to 150 μm in diameter,

the content of Ca ions is less than 1 ppm.

In the general formula (A), R¹～R⁸Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom or an amino group.

The invention 2 is as follows.

A powder of a compound represented by the following general formula (A),

d is the cumulative 50% diameter of the volume measured by laser diffraction scattering method₅₀The arithmetic volume mean diameter measured by a laser diffraction scattering method is defined as D_aveWhen the temperature of the water is higher than the set temperature,

D₅₀is 50 to 100 μm in diameter,

D₅₀/D_ave1.1 to 1.5.

The 3 rd invention is as follows.

A powder of a compound represented by the following general formula (A),

volume-based cumulative 50% diameter D by laser diffraction Scattering₅₀Is 50 to 100 μm in diameter,

the angle of repose of the powder is 35-49 degrees.

The 4 th invention is as follows.

A powder which is a powder of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane,

the half-value width of a peak near 22.3 DEG or more in an X-ray diffraction spectrum is 0.050 DEG to 0.180 DEG,

the half-value width of a peak near 23.7 DEG of 2 theta in an X-ray diffraction spectrum is 0.050 DEG to 0.120 DEG inclusive,

The half-value width of a peak in the vicinity of 25.8 ° 2 θ in the X-ray diffraction spectrum is 0.040 ° or more and 0.120 ° or less.

The present inventors have completed the following invention of a powder production method.

A method for producing a powder of a compound represented by the following general formula (A),

the method comprises the following steps:

a melting step of putting a raw material substance containing the compound represented by the general formula (a) and an aqueous dispersion medium into a container and heating the raw material substance to melt the raw material substance in the presence of the aqueous dispersion medium to obtain a heterogeneous liquid containing a melt of the raw material substance and the aqueous dispersion medium;

a crystallization step of obtaining crystals by cooling the heterogeneous liquid to crystallize the melt;

in the melting step, the melting temperature T of the raw material₁The solubility of the compound represented by the general formula (A) in the aqueous dispersion medium is 10[ g/100 g%]The following.

The present inventors have also completed the following invention of a solution preparation method.

A method for producing a solution containing a compound represented by the following general formula (A),

the method comprises a step of obtaining a solution of the compound represented by the general formula (A) by using a solvent and the powder of at least any one of the inventions 1 to 4.

ADVANTAGEOUS EFFECTS OF INVENTION

The powder of the present invention is excellent in industrial operability.

Drawings

Fig. 1 is a diagram for explaining a particle size distribution of the powder according to embodiment 2.

Fig. 2 is a diagram for explaining the particle size distribution of the powder of embodiment 2.

Detailed Description

The embodiments of the present invention will be described in detail below.

In the present specification, the expression "X to Y" in the description of the numerical range means X or more and Y or less unless otherwise specified. For example, "1 to 5 mass%" means "1 mass% or more and 5 mass% or less".

In the expression of a group (atomic group) in the present specification, the expression substituted or unsubstituted includes both the case of having no substituent and the case of having a substituent. For example, "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

The term "electronic device" in this specification is used in a meaning including a semiconductor chip, a semiconductor element, a printed wiring board, a circuit display device, an information communication terminal, a light emitting diode, a physical battery, a chemical battery, and the like, an element, a device, a final product, and the like to which an electronic engineering technique is applied.

In the present specification, the compound represented by the general formula (a) may be referred to as "compound (a)".

In this specification, the embodiment of the 1 st invention may be referred to as the 1 st embodiment, the embodiment of the 2 nd invention may be referred to as the 2 nd embodiment, the embodiment of the 3 rd invention may be referred to as the 3 rd embodiment, and the embodiment of the 4 th invention may be referred to as the 4 th embodiment.

In the present specification, an embodiment of the invention of the powder production method disclosed above may be referred to as a method 1. On the other hand, a method for producing a powder which can produce the powder of the present invention (the powder of at least any one of the inventions 1 to 4) may be referred to as the method 2, but the method 2 is not an invention of the powder production method disclosed above.

< powder >

The powder of embodiments 1 to 3 is a powder of a compound (a)) represented by the following general formula (a). In addition, the powder of embodiment 4 is represented by the following general formula (A) wherein R is ¹～R⁸Powders of compounds all of which are hydrogen atoms.

In the general formula (A), as R¹～R⁸Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

In the general formula (A), R is preferred¹～R⁸Each independently a hydrogen atom or an amino group.

In the general formula (A), in R¹～R⁸In the case where at least any one of them is a group other than a hydrogen atom, the group other than a hydrogen atom is preferably present in R²、R³、R⁶、R⁷At any position in (a). The reason is that the compound is easily synthesized.

General formula (VII)(A) In, R¹～R⁸Of these, 0 to 4 groups other than hydrogen atoms are preferable, and 0 to 2 groups other than hydrogen atoms are more preferable.

As the compound (A), specifically, examples thereof include 2, 2-bis (4-hydroxyphenyl) hexafluoropropane, 2-bis (4-hydroxy-3-methylphenyl) hexafluoropropane, 2-bis (3-ethyl-4-hydroxyphenyl) hexafluoropropane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) hexafluoropropane, 2-bis (3-fluoro-4-hydroxyphenyl) hexafluoropropane, 2-bis (3-bromo-4-hydroxyphenyl) hexafluoropropane, 2-bis (3, 5-dibromo-4-hydroxyphenyl) hexafluoropropane and 2, 2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane.

In particular, the following compounds are listed as preferable compounds (a).

(embodiment 1)

Mode particle diameter (Mode particle diameter) D of the powder of embodiment 1 measured by a laser diffraction scattering method_mIs 75 to 150 μm, preferably 75 to 135 μm, and more preferably 75 to 120 μm.

The powder of embodiment 1 has a Ca ion content of less than 1ppm, preferably 0.7ppm or less, and more preferably 0.5ppm or less. In the present specification, "ppm" of the content of Ca ions (and Na ions described below) is a part per million of "mass of Ca ions in powder/mass of powder", which is explained in advance for the sake of caution. The relationship between "ppm" and mass% is 1ppm to 0.0001 mass%.

The powder of embodiment 1 has good industrial operability. Specifically, the powder of embodiment 1 has advantages such as "good filterability" and "short drying time for drying wet powder". The reason for these advantages is presumed to be D_m75 to 150 μm.

Although the details are not clear, it is presumed that D may be the cause of_mAt least 75 μm, and therefore, there are moderate "gaps" between particles, and the liquid flows easily. In addition, push away Detect as a result of D_mSince the "gap" is not so large as to be 150 μm or less, a large amount of liquid is not easily held between particles.

In addition, the inventors of the present invention controlled the content of Ca ions in the powder to less than 1ppm in embodiment 1.

Ca ions are components inevitably contained in general industrial water. Thus, when the powder of the compound (a) is produced so that the amount thereof is less than 1ppm by using the content of Ca ions as an index, the amount of various trace impurities (derived from industrial water) other than Ca ions in the obtained powder can be reduced together. That is, it is considered that the compound (a) having a Ca ion content of less than 1ppm has a small amount of Ca ions and a small amount of various impurities, and the compound (a) can be suitably used in various technical fields. Further, since Ca ions can be measured by ion chromatography as described below, process control in a mass-production facility can be facilitated.

Incidentally, the content of Ca ions being less than 1ppm directly means that the powder of embodiment 1 can be preferably used as a material for electronic device fabrication requiring a small amount of metal ions.

The content of Ca ions is preferably 0.7ppm or less, more preferably 0.5ppm or less.

The smaller the amount of Ca ion, the more preferable. The content of Ca ions may be zero (not more than the measurement limit of the apparatus). From the viewpoint of practicality, the content of Ca ions is, for example, 0.01ppm or more.

The method and conditions for producing the powder of embodiment 1 are not limited. By selecting appropriate method and conditions, D can be obtained_mA powder of the compound (A) having a Ca ion content of less than 1ppm and a particle size of 75 to 150 μm. Preferably, as described in the following production method 1, the raw material is melted (undissolved) in an aqueous dispersion medium and then crystallized. D can be obtained by appropriately selecting the conditions for melting and crystallization_mA powder of the compound (A) having a Ca ion content of less than 1ppm and a particle size of 75 to 150 μm. The production method and production conditions are described later in detail.

The Na ion content of the powder of embodiment 1 is less than 1ppm, preferably 0.7ppm or less, and more preferably 0.5ppm or less. By setting the Na ion amount to less than 1ppm in addition to Ca ions, the powder of the present embodiment can be further suitably used for electronic device production. The content of Na ions may be zero (not more than the measurement limit of the apparatus). From the viewpoint of practicality, the content of Na ions is, for example, 0.01ppm or more.

The powder of embodiment 1 has a Mg ion content of less than 1ppm, preferably 0.7ppm or less, and more preferably 0.5ppm or less. Similarly to Ca ions, the content of Mg ions is also an index that can be used when calculating the hardness of water, and Mg ions are inevitably contained in industrial water in some cases. Accordingly, the amount of Mg ions other than Ca ions is less than 1ppm, and the powder of the present embodiment can be further suitably used for various applications such as electronic device manufacturing. The content of Mg ions may be zero (not more than the measurement limit of the apparatus). From the viewpoint of practicality, the content of Mg ions is preferably 0.01ppm or more, for example.

The content of metal ions such as Ca ions can be determined by ion chromatography. In the case of ion chromatography, a sample liquid is usually prepared by dissolving a powder of the compound (a) in an organic solvent such as t-butyl methyl ether. The content of metal ions in the sample liquid was measured, and "mass of Ca ions in powder/mass of powder" was calculated from the obtained measurement value.

In the conventional purification method of BIS-AF, particularly the reprecipitation method using water, since the water itself used contains metal ions, the amount of metal ions is not easily reduced in many cases. As described in the following production method 1, a powder containing a small amount of metal ions such as Ca ions can be obtained by recrystallizing the compound (a) using water by a method of "non-positively dissolving" the compound (a) in water.

The powder of embodiment 1 preferably contains no alcohol such as a monohydric alcohol or a dihydric alcohol, or contains a small amount of the alcohol. More preferably, the alcohol is contained in a small amount of a water-soluble monohydric alcohol having 4 or less carbon atoms, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, and 2-methyl-2-propanol.

The content of the alcohol in the powder of embodiment 1 is preferably 400ppm or less, more preferably 200ppm or less, and still more preferably 100ppm or less. The term "alcohol" as used herein, excluding a phenolic compound (a compound having a phenolic hydroxyl group), is common chemical knowledge, but is explained in advance for the sake of caution.

Since the powder does not contain an alcohol or contains a small amount of alcohol, when a polymer is produced using the powder of the present embodiment as a raw material, an unexpected reaction is less likely to occur, and a desired polymer is easily produced.

Further, since the compound (a) can form a hydrogen bond with an alcohol, there is an advantage that it is easy to accurately measure the amount of the pure compound (a) by making the powder contain no or a small amount of the alcohol. In this case, for example, the "equivalent ratio" in the reaction of the compound (a) and the epoxy compound can be accurately controlled, and the physical properties of the finally obtained resin can be easily and precisely controlled.

Incidentally, in patent document 1, since ethylene glycol is used in purifying BIS-AF, it is considered that the BIS-AF described in patent document 1 contains more than 400ppm of ethylene glycol.

On the other hand, when the powder of embodiment 1 is produced by the following production method (method 1), an alcohol may be used as a part of the dispersion medium in which the compound (a) is dispersed. However, since compound (a) is not actively "dissolved" in alcohol in process 1, the amount of alcohol in the powder is small. In addition, in the case of using only water as a dispersion medium, the compound (a) does not contain an alcohol in principle.

The amount of the alcohol in the compound (a) can be determined, for example, by gas chromatography.

D represents the cumulative 50% diameter of the powder of embodiment 1 on a volume basis as measured by a laser diffraction scattering method₅₀When D is₅₀Preferably 40 to 100 μm, more preferably 40 to 90 μm, and further preferably 40 to 80 μm.

The powder of embodiment 1 is due to D₅₀Within the specific numerical range, the operability can be further improved. Due to D₅₀Relatively large, it is considered that the contact area of the particles with each other becomes smaller and the friction of the particles with each other at the time of flowing becomes smaller. In addition, it is considered that the filterability, the drying property, and the like are further optimized.

In the powder of embodiment 1, D represents a volume-based cumulative 90% diameter measured by a laser diffraction scattering method₉₀When (D)₉₀-D₅₀)/D₅₀The value of (b) is preferably 1.3 to 1.7, more preferably 1.4 to 1.7.

(D₉₀-D₅₀)/D₅₀This index can be said to be an index showing the state of expansion of the "skirt" on the large particle diameter side in the particle diameter distribution curve. A value of 1.7 or less means that the particle size distribution is relatively sharp on at least the large particle size side. Since the particle size distribution is sharp, it is considered that the homogeneity of the powder is improved and the handling property is further improved.

In addition, (D)₉₀-D₅₀)/D₅₀A value of 1.7 or less is also considered to mean that coarse particles are relatively small. Since the coarse particles are relatively small, for example, the blocking may be suppressed.

At one hand, as (D)₉₀-D₅₀)/D₅₀The lower limit of the preferable range of (2) is 1.3, which is set within a range that does not require excessive costs and labor for recrystallization when obtaining a powder of the compound (a).

As an index similar to the above, (D) in the powder of embodiment 1₉₀-D_m)/D_mThe value of (b) is preferably 0.93 or less, more preferably 0.92 or less. (D)₉₀-D_m)/D_mThe lower limit of the value of (b) is, for example, 0.40 or more.

In another aspect, the average particle diameter of the powder of embodiment 1 measured by a laser diffraction scattering method is D_aveWhen D is_avePreferably 45 to 80 μm, and more preferably 45 to 60 μm. As a tendency to be large, the powder of embodiment 1 tends to have a larger average particle size than the powder of the conventional compound (a).

In embodiment 1, D_m、D₅₀Various values of correlation of the equal particle diameters can be obtained by scattering by laser diffractionThe volume-based particle size distribution curve was determined. Examples of the device capable of performing the measurement by the laser diffraction scattering method include a particle size distribution analyzer "SALD" series manufactured by Shimadzu corporation. The measurement is usually performed by wet measurement by dispersing the powder in a solvent (e.g., n-decane) which does not substantially dissolve the powder.

(embodiment 2)

D represents the cumulative 50% diameter of the powder of embodiment 2 on a volume basis as measured by a laser diffraction scattering method ₅₀And D is the arithmetic volume mean diameter measured by a laser diffraction scattering method_aveWhen, D₅₀50 to 100 μm, D₅₀/D_ave1.1 to 1.5.

The reason why the powder of embodiment 2 is excellent in handling is presumed as follows.

If the particle diameter of the particles included in the powder is relatively large, the contact area between the particles becomes relatively small, and therefore, it is estimated that the friction between the particles at the time of flowing becomes small.

In embodiment 2, D₅₀It is assumed that the powder has a particle size of 50 μm or more, that is, the powder contains 50% or more of relatively large particles having a particle size of 50 μm or more on a volume basis, and therefore the friction between the particles during the flow is reduced.

In embodiment 2, D₅₀/D_aveThe shape of the particle size distribution curve in which the frequency of plotting the particle size on the vertical axis is 1.1 or more and the particle size on the horizontal axis is not bilaterally symmetric (normal distribution) as shown in fig. 2, but is shifted to the right (larger particle size) as shown in fig. 1. Even if D is the same₅₀In the particle size distribution shown in fig. 1, the proportion of relatively large particles to the entire particles is large, and therefore the contact area between the particles is likely to become smaller. Thus, it is presumed that the friction between the particles at the time of flowing becomes smaller.

This is presumed to be good in operability.

From another viewpoint, the powder of embodiment 2 has good solvent solubility. That is, surprisingly, although the powder of the present embodiment has a relatively large D ₅₀But dissolves relatively quickly in the solvent.The inventors surmised that the reason for this is that expansion and aggregation of BIS-AF in the solvent are suppressed because of the small number of particles having a small particle diameter in the powder (when expansion and aggregation occur, the dispersibility of the powder is lowered and the dissolution rate is lowered).

At one's best, as D₅₀The upper limit of (2) is 100 μm, which is set within a range that does not excessively increase the cost and labor for recrystallization when obtaining a powder of the compound (A). D₅₀/D_aveThe same applies to the upper limit value of 1.5.

The method and conditions for producing the powder of embodiment 2 are not limited. However, to obtain D₅₀50 to 100 μm, D₅₀/D_aveThe compound (A) is 1.1 to 1.5 in powder form, and the method and conditions are preferably selected appropriately.

In the present embodiment, for example, when a powder of the compound (a) is obtained by recrystallization, it is preferable to use a specific organic solvent, use a seed crystal, or perform slow cooling. D can be obtained by selecting an appropriate production method and production conditions₅₀50 to 100 μm, D₅₀/D_ave1.1 to 1.5 in terms of a powder of the compound (A). The specific production method will be described below as "production method 2". To be careful, the powder of embodiment 2 may be produced by method 1.

As described above, D of the powder of embodiment 2₅₀50 to 100 μm, D₅₀/D_ave1.1 to 1.5.

D₅₀Preferably 50 to 90 μm, more preferably 50 to 80 μm, and further preferably 50 to 70 μm.

D₅₀/D_avePreferably 1.1 to 1.4, more preferably 1.1 to 1.3.

In the powder of embodiment 2, the Mode particle diameter (Mode particle diameter) D measured by the laser diffraction scattering method is used_mThe fluidity can be further improved by setting the amount to fall within a specific range. Due to D_mRelatively large, it is considered that the contact area of the particles with each other becomes smaller and the friction of the particles with each other at the time of flowing becomes smaller. In addition, the operability is considered to be further improved.

As a specific numerical value, D_mPreferably 75 to 150 μm, and more preferably 80 to 120 μm.

In the powder according to embodiment 2, the cumulative 90% diameter on volume basis as measured by the laser diffraction scattering method is denoted by D₉₀When (D)₉₀-D₅₀)/D₅₀The value of (b) is preferably 1.3 to 1.7, more preferably 1.4 to 1.7.

(D₉₀-D₅₀)/D₅₀This index can be said to be an index showing the expansion of the "downward swing" on the right side (large particle diameter side) on the particle diameter distribution curve. Consider (D)₉₀-D₅₀)/D₅₀A particle diameter of 1.7 or less means that the particle diameter distribution on the large particle diameter side is relatively sharp, and has a sharp transition from D to D₅₀/D_aveFrom a different viewpoint, the particle size distribution of the powder is a distribution deviating from the normal distribution of fig. 1. Thus, due to the removal of D ₅₀/D_aveIs other than 1.1 to 1.5, (D)₉₀-D₅₀)/D₅₀Since the content is 1.7 or less, the workability is further improved.

Further, consider (D)₉₀-D₅₀)/D₅₀A value of 1.7 or less also means that the number of coarse particles is relatively small. Since the coarse particles are relatively small, for example, the blocking may be further suppressed.

At one hand, as (D)₉₀-D₅₀)/D₅₀The lower limit of 1.3 of the preferable range is set to a range in which the cost and labor for recrystallization in obtaining the powder of the compound (a) are not excessive.

In embodiment 2, D₅₀、D₉₀、D_aveAnd D_mThe volume-based particle size distribution curve can be obtained by a laser diffraction scattering method. Examples of the device capable of performing the measurement by the laser diffraction scattering method include a particle size distribution analyzer "SALD" series manufactured by Shimadzu corporation. The measurement is usually performed by wet measurement by dispersing the powder in a solvent (e.g., n-decane) which does not substantially dissolve the powder. For details of the measurement method, reference is made to examples disclosed later.

(bulk Density)

The bulk density of the powder in embodiment 2 is within a certain range of values, and therefore the handling of the powder can be further improved.

Specifically, the loose bulk density of the powder of embodiment 2 is preferably 0.50 to 0.75g/cm ³More preferably 0.60 to 0.75g/cm³. The tap bulk density of the powder of the present embodiment is preferably 0.76 to 0.90g/cm³More preferably 0.80 to 0.90g/cm³。

For the method of measuring the loose bulk density and the tapped bulk density, please refer to the examples disclosed later.

(embodiment 3)

D of powder of embodiment 3₅₀50 to 100 μm. D₅₀Preferably 50 to 90 μm, more preferably 50 to 80 μm, and further preferably 50 to 70 μm.

In the powder of embodiment 3, the Mode particle diameter (Mode particle diameter) D measured by a laser diffraction scattering method is used_mSet within a specific numerical range, thereby enabling further improvement in fluidity. Due to D_mRelatively large, it is considered that the contact area of the particles with each other becomes smaller and the friction of the particles with each other at the time of flowing becomes smaller. In addition, the operability is considered to be further improved.

In the powder according to embodiment 3, the cumulative 90% diameter on volume basis as measured by the laser diffraction scattering method is defined as D₉₀When (D)₉₀-D₅₀)/D₅₀The value of (b) is preferably 1.3 to 1.7, more preferably 1.4 to 1.7.

(D₉₀-D₅₀)/D₅₀This index can be said to be an index showing the state of expansion of the "skirt" on the large particle diameter side on the particle diameter distribution curve. A value of 1.7 or less means that the particle size distribution is relatively sharp on at least the large particle size side. Since the particle size distribution is sharp, it is considered that the homogeneity of the powder is improved and the handling property is further improved.

In addition, (D)₉₀-D₅₀)/D₅₀A value of 1.7 or less is considered to mean that coarse particles are relatively small. Since the coarse particles are relatively small, for example, the blocking may be further suppressed.

Taken as (D)₉₀-D₅₀)/D₅₀The lower limit of 1.3 of the preferable range is set to a range in which the cost and labor for recrystallization in obtaining the powder of the compound (a) are not excessive.

In embodiment 3, D₅₀、D₉₀And D_mThe volume-based particle size distribution curve can be obtained by a laser diffraction scattering method. Examples of the device capable of performing the measurement by the laser diffraction scattering method include a particle size distribution analyzer "SALD" series manufactured by Shimadzu corporation. The measurement is usually performed by wet measurement by dispersing the powder in a solvent (e.g., n-decane) which does not substantially dissolve the powder.

As described above, the powder of embodiment 3 has an angle of repose of 35 to 49 °. The angle of repose is preferably 40 to 49 degrees, and more preferably 40 to 47 degrees.

The method of measuring the angle of repose is described in examples disclosed below.

By appropriately designing the bulk density of the powder of embodiment 3, the handling properties of the powder can be further improved.

Specifically, the loose bulk density ρ of the powder of embodiment 3 ₁Preferably 0.50 to 0.75g/cm³More preferably 0.60 to 0.75g/cm³. In addition, the tap bulk density ρ of the powder of embodiment 3₂Preferably 0.76 to 0.90g/cm³More preferably 0.80 to 0.90g/cm³。

The loose bulk density and the tapped bulk density were measured by the following examples.

In particular, in embodiment 3, ρ₂/ρ₁Preferably 1.01 to 1.45, and more preferably 1.10 to 1.40. By making rho₂/ρ₁The amount is 1.45 or less, and for example, when the powder of the present embodiment is weighed, the variation in the weighed mass can be sufficiently reduced.

(embodiment 4)

The powder of embodiment 4 is 2, 2-bis (4-hydroxyphenyl) hexafluoropropane (R in the general formula (A))¹～R⁸All of hydrogen atoms) is added to the powder,

a half-value width of a peak near 22.3 DEG (2 theta) in an X-ray diffraction (XRD) spectrum is 0.050 DEG to 0.180 DEG inclusive,

Specifically, the powder according to embodiment 4 has advantages such as "a high dissolution rate in a solvent, particularly a polar solvent or an alkaline solvent", and "a short drying time for drying a wet powder". These advantages are presumed to originate as follows: the half width of a peak near 22.3 ° 2 θ in the X-ray diffraction spectrum is 0.050 ° to 0.180 °, the half width of a peak near 23.7 ° 2 θ in the X-ray diffraction spectrum is 0.050 ° to 0.120 °, and the half width of a peak near 25.8 ° 2 θ in the X-ray diffraction spectrum is 0.040 ° to 0.120 °.

The present inventors have focused on the half-value width of a peak at 3 specific 2 θ in the X-ray diffraction spectrum of the powder.

Although details are not clear, it is considered that the size of crystallites of the powder is large and the size of crystallites of the entire powder is uniform by designing the powder so that the half width of the peak near 22.3 ° 2 θ, near 23.7 ° 2 θ, and near 25.8 ° 2 θ, which are unique to 2, 2-bis (4-hydroxyphenyl) hexafluoropropane, is small.

From this, it is considered that when the fine crystal is dissolved in the solvent, aggregation due to the size unevenness of the fine crystal is suppressed, and the dissolution rate in the solvent becomes high. Further, when the wet powder is dried, aggregation due to the size unevenness of the fine crystals is suppressed, and therefore, it is presumed that the liquid component is less likely to exist between the particles of the powder and the drying time of the powder can be shortened.

The vicinity of 2 θ of 22.3 ° in the X-ray diffraction spectrum refers to a range of ± 1 ° centered on 2 θ of 22.3 °, and the peak of the vicinity of 2 θ of 22.3 ° in the X-ray diffraction spectrum refers to a maximum peak in a range of ± 1 ° centered on 2 θ of 22.3 °.

The vicinity of 23.7 ° in the X-ray diffraction spectrum means a range of ± 1 ° centered on 23.7 ° 2 θ, and the peak of the vicinity of 23.7 ° 2 θ in the X-ray diffraction spectrum means a maximum peak in a range of ± 1 ° centered on 23.7 ° 2 θ.

The vicinity of 25.8 ° in the X-ray diffraction spectrum means a range centered at ± 1 ° with 2 θ being 25.8 °, and the peak in the vicinity of 25.8 ° in the X-ray diffraction spectrum means a maximum peak in a range centered at ± 1 ° with 2 θ being 25.8 °.

The powder of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane has a peak half-value width at around 22.3 ° 2 θ in an X-ray diffraction spectrum of 0.050 ° to 0.180 °.

The half-value width of the peak in the vicinity of 22.3 ° 2 θ in the X-ray diffraction spectrum is preferably 0.055 ° or more, and more preferably 0.060 ° or more.

Further, it is preferably 0.170 ° or less, and more preferably 0.165 ° or less.

The powder of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane has a peak half-value width at about 23.7 ° in an X-ray diffraction spectrum of 0.050 ° to 0.120 °.

The half-value width of the peak in the vicinity of 23.7 ° 2 θ in the X-ray diffraction spectrum is preferably 0.055 ° or more, and more preferably 0.060 ° or more.

Further, it is preferably 0.100 ° or less, and more preferably 0.090 ° or less.

The half-value width of a peak near 25.8 ° of 2 θ in an X-ray diffraction spectrum of a powder of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane is 0.040 ° or more and 0.120 ° or less.

The half-value width of the peak in the vicinity of 25.8 ° 2 θ in the X-ray diffraction spectrum is preferably 0.045 ° or more, and more preferably 0.050 ° or more.

Further, it is preferably 0.115 ° or less, and more preferably 0.110 ° or less.

X-ray of powderLine diffraction (XRD) spectroscopy can be performed by using

The measurement was carried out by an X-ray powder diffractometer (Smart Lab; Rigaku corporation) for irradiation.

The measurement sample is prepared by grinding a sample in a mortar, collecting a non-reflective sample plate (available from Rigaku corporation, etc.) having no diffraction peak in the measurement range, flattening the sample plate, and measuring the sample plate by placing the sample plate in the apparatus. An example of the measurement conditions is as follows.

[ measurement conditions for X-ray diffraction ]

A bulb tube: cu

Voltage: 40kV

Current: 50mA

Solar energy gap: 2.5 degree (incident side, light receiving side)

Scanning range: 10 to 80 DEG

Step width: 0.01 degree

Scanning speed: 35 deg./min

A detector: one-dimensional X-ray detector (D/tex Ultra 250; manufactured by Rigaku corporation)

In the X-ray diffraction spectrum obtained by the measurement, the half-value widths (θ is the bragg angle) of peaks near 22.3 °, 23.7 °, and 25.8 ° were calculated, respectively. The half-value width of the peak was calculated using Smart Lab studio II (analytical software: Power XRD).

The method and conditions for producing the powder of embodiment 4 are not limited. For example, as described in the following method 1, a raw material is melted in an aqueous dispersion medium and then crystallized at the following temperature T ₂By maintaining the crystallization for a sufficient time (for example, 30 minutes or longer), a powder having a peak near 22.3 ° in the X-ray diffraction (XRD) spectrum, a peak near 23.7 ° in the X-ray diffraction (XRD) spectrum, and a half-value width of a peak near 25.8 ° in the X-ray diffraction (XRD) spectrum, which are within the above ranges, can be obtained.

The particle size of the powder of embodiment 4 is not particularly limited, and may have appropriate handling properties. For example, a volume measured by laser diffraction scatteringProduct benchmark cumulative 50% diameter (D)₅₀) Preferably 20 to 100 μm. The lower limit may be more preferably 30 μm or more, and even more preferably 40 μm or more, and the upper limit may be more preferably 90 μm or less, and even more preferably 80 μm or less.

Examples of the device capable of performing the measurement by the laser diffraction scattering method include a particle size distribution analyzer "SALD" series manufactured by Shimadzu corporation. The measurement is usually performed by wet measurement by dispersing the powder in a solvent (e.g., n-decane) which does not substantially dissolve the powder.

< method for producing powder >

The powder of embodiments 1 to 4 can be produced by an appropriate production method. Two preferred production methods (the 1 st production method and the 2 nd production method) for producing the powder of embodiments 1 to 4 will be described below.

(preparation 1)

Method for producing powder of compound represented by general formula (A) (method 1)

The method comprises the following steps:

a melting step of melting a raw material containing a compound represented by the general formula (a) and an aqueous dispersion medium in the presence of the aqueous dispersion medium by placing the raw material and the aqueous dispersion medium in a container and heating the raw material to obtain a heterogeneous liquid containing a melt of the raw material and the aqueous dispersion medium;

a crystallization step of cooling the heterogeneous liquid to crystallize the melt, thereby obtaining crystals.

In the melting step of the method 1, the melting temperature T of the raw material₁The solubility of the compound represented by the following general formula (A) in an aqueous dispersion medium is 10[ g/100g]Hereinafter, it is preferably 8[ g/100g ]]The following. The lower limit of the solubility may be zero, and the solubility is usually 0.5[ g/100g ]]The above.

"melting temperature T of raw Material substance₁"means the lowest temperature at which all of the powdery (solid) raw material is melted and loses its original shape. The total melting of the raw material substances can be confirmed by the following method or the like: (i) for the shape of the raw material in the containerVisually observing the state, and confirming that no powdery (solid) raw material exists, thereby confirming that all the raw material is melted; (ii) the water layer extracted from the container was rapidly visually observed, and it was confirmed that the raw material was not left in a powdery (solid) form.

The method 1 can be described as follows.

In the melting step, the raw material containing the compound (A) is heated in an aqueous dispersion medium at a temperature T₁Then, the resultant was melted (non-dissolved) to prepare a melt. The aqueous dispersion medium is simply said to be at a temperature T₁The following is a "poor solvent" for the compound (a) (a liquid in which the compound (a) is not easily dissolved). By heating the compound (a) in a poor solvent (aqueous system) for the compound (a), a heterogeneous liquid containing a melt of the raw material and an aqueous dispersion medium is obtained.

In the crystallization step, the melt in the heterogeneous liquid is crystallized.

In the method 1, it is considered that the amount of Ca ions or the like can be reduced because Ca ions or the like move from the raw material side to the aqueous dispersion side at the interface between the melt of the raw material and the aqueous dispersion. From the viewpoint of producing the powder of embodiment 1 (with a small amount of Ca ions), it is preferable.

In addition, in the method 1, since the raw material is not actively "dissolved" (without passing a state where the solute and the solvent are completely and uniformly mixed), it is considered that it is possible to suppress that Ca ions or the like, which are impurities derived from a solvent such as water, are mixed into the raw material and recrystallized. Similarly, it is considered that incorporation of impurities, i.e., Ca ions and the like, temporarily eluted from the raw material into the crystallized raw material is suppressed. These are also considered to be related to the ability to reduce the amount of impurities such as Ca ions.

Incidentally, for example, BIS-AF does not melt even when it is heated to 100 ℃ (boiling point of water) alone, but BIS-AF in water melts when it is heated to 100 ℃ (or a temperature lower than 100 ℃). The reason for this is that BIS-AF has a lowered melting point due to hydration, based on known information and findings of the present inventors. The known information reference is, for example, the above patent document 3.

The 1 st recipe also has an additional advantage of less environmental load. Specifically, in the case of the method 1, an aqueous dispersion is mainly used, and an organic solvent (a good solvent for the compound (a)) is not required. That is, by adopting the above-mentioned production method, the use of organic solvents can be reduced, and therefore, the environmental load can be reduced.

The melting step and the crystallization step will be described in detail below.

Melting step

In the melting step, the raw material containing the compound (a) and the aqueous dispersion medium are usually heated in a vessel equipped with a stirring mechanism and a heating mechanism. In this way, a heterogeneous liquid containing a melt of the raw material substance and the aqueous dispersion medium can be obtained. The heterogeneous liquid is usually changed to a liquid in a suspended state by heating while stirring. The heterogeneous liquid is usually in a 2-layer separated state without stirring or with stirring stopped and left to stand. Incidentally, it is considered that by heating while stirring, the melt of the raw material and the aqueous dispersion medium are sufficiently brought into contact with each other, and Ca ions and the like are more likely to move from the raw material side to the aqueous dispersion side.

As an example, the aqueous dispersion may substantially contain only water. By using an aqueous dispersion containing substantially only water, the amount of alcohol in the finally obtained compound (a) can be made substantially zero. Further, since the solubility of the compound (a) in water is very small, there is also an advantage that the compound (a) contained in the waste liquid can be reduced.

As another example, the aqueous dispersion may include water and an alcohol. In this case, the alcohol content in the aqueous dispersion medium is usually 30% by mass or less, preferably 1 to 30% by mass, and more preferably 5 to 25% by mass. If the ratio of the alcohol is too large, the raw material may not be properly dispersed in the aqueous dispersion, and most of the raw material may be "dissolved". Accordingly, the ratio of the alcohol in the aqueous dispersion is preferably set to the above-described level.

By using a water-based dispersion containing water and an alcohol, the temperature T can be lowered₁The advantages of (1). According to the findings of the present inventors, only water is used as a water systemIn the case of the dispersion, T₁At 90 ℃ or higher, and a water-based dispersion containing 30 mass% or less of an alcohol having T₁Less than 90 ℃ and about 30 to 90 ℃. Due to T₁Since the temperature is low, delicate temperature adjustment is easy, and crystals are easy to grow in a crystallization step described later, for example.

The ratio of the raw material to the aqueous dispersion can be appropriately set in consideration of the effect of reducing impurities such as Ca ions (the more the aqueous dispersion used, the more the Ca ions and the like in the raw material are moved to the side of the aqueous dispersion), and the cost. The amount of the aqueous dispersion is usually 100 to 3000 parts by mass, preferably 200 to 1500 parts by mass, per 100 parts by mass of the raw material.

Temperature T₁The specific structure of the compound (a) and the composition of the aqueous dispersion may vary. In the melting step, the temperature and time are appropriately set according to the need. In the melting step, all of the compound (a) may be melted except the amount dissolved in the aqueous dispersion.

Crystallization step

In the crystallization step, the heterogeneous liquid obtained in the melting step is cooled to crystallize the melt in the heterogeneous liquid. By appropriately selecting the specific conditions for lowering the temperature, it is possible to obtain a particle size distribution with a small amount of Ca ions or the like and with appropriate control (for example, D in embodiment 1_m75 to 150 μm) of the compound (A). Further, by appropriately selecting specific conditions for temperature reduction, or by allowing control of the crystallite size or the like, a powder of the compound (a) having a relatively small half-value width of the XRD spectrum can be obtained.

The crystallization step in the method 1 is different from a general crystallization step, i.e., a step of crystallizing a substance dissolved in a uniform "solution".

In a general crystallization step, it is necessary to gradually lower the temperature of the solution as crystals precipitate.

On the other hand, in the crystallization step in the method 1, the heterogeneous liquid may be cooled to a temperature not higher than a certain temperature (lower than the melting temperature), and it is not always necessary to "slowly lower" the temperature. Since most of the compound (a) is "melted" and not "dissolved", most of the compound (a) can be crystallized (solidified) by maintaining the temperature at a certain temperature or lower (lower than the melting temperature). The crystal (final product) obtained by such an unusual crystallization mechanism is different from the conventional crystal.

In particular, when the aqueous dispersion medium contains an alcohol, for example, the temperature reduction operation can be performed at an appropriate speed because a certain amount of the compound (a) "dissolves" in the dispersion medium. In the crystallization step, the temperature may be lowered after a certain temperature lower than the melting temperature is maintained.

Temperature T of crystallization step₂Preferably the specific temperature T₁The temperature is 1 to 10 ℃ lower, and more preferably 1 to 8 ℃ lower. Specifically, in the crystallization step, it is preferable that the system is kept at the temperature T ₂(specific temperature T)₁In the range of 1 to 10 ℃ lower) for preferably 30 minutes or longer, more preferably 60 minutes or longer. By adjusting the temperature T₂Maintaining for a sufficiently long time, it is easy to obtain a sufficient reduction in Ca ions and the like, and to appropriately control the particle size distribution (for example, as described in embodiment 1, D_m75 to 150 μm). On the other hand, from the viewpoint of production efficiency, the temperature T is maintained in the crystallization step₂The time of (c) is preferably 300 minutes or less, for example.

The crystallization step is preferably performed while stirring the heterogeneous liquid. When stirring is performed in the melting step, it is preferable to continue stirring as it is. Thus, the amount of impurities such as Ca ions can be easily reduced sufficiently. Further, since the dispersion is constantly stirred, it is easy to obtain a dispersion in which crystal growth is appropriately controlled and particle size distribution is appropriately controlled (for example, as described in embodiment 1, D_m75 to 150 μm). The stirring is preferably performed at a speed of 50 to 500rpm, more preferably at a speed of 150 to 300 rpm.

In the crystallization step, a seed crystal may be used or may not be used. When the seed crystal is used, the amount thereof added may be about 1/1000 to 1/100 in terms of mass ratio of the compound (a) dispersed in the aqueous dispersion medium. The seed crystal is not particularly limited, and may be a solid compound (a).

Treatment after the crystallization step

After the crystallization step, the system is usually cooled to room temperature (about 25 ℃).

The cooling conditions are not particularly limited. The cooling may or may not be natural cooling. As described above, the present embodiment is different from the conventional art in which the compound (a) is crystallized "dissolved", and therefore, a large amount of the compound (a) is precipitated without cooling.

However, since the aqueous dispersion medium dissolves a small amount of the compound (a), a small amount of crystals precipitates by cooling. From the viewpoint of fine adjustment of the amount of Ca ions and the particle size distribution, the cooling is preferably performed slowly at about 0.1 to 0.3[ deg.C/min ].

After cooling, the obtained crystals are recovered by, for example, filtration under reduced pressure, washed with water, and dried under reduced pressure in an environment of about 20 to 50 ℃, whereby a final powder can be obtained.

(preparation 2)

The method for producing a powder of a compound represented by general formula (a) (the 2 nd production method) includes, for example, a series of steps 1 to 4 below. By such a step, the particle size distribution can be appropriately controlled (for example, as described in embodiment 2, D₅₀50 to 100 μm, D₅₀/D_ave1.1 to 1.5) of the compound (A).

Step 1: preparation of the raw materials

First, a substance having a chemical structure represented by general formula (a) is prepared as a raw material. Such a raw material can be obtained by, for example, the method described in patent document 2. Commercially available raw materials can be used.

Step 2: dissolution in organic solvents (heating, etc.)

The raw material prepared in step 1 is put into an organic solvent. The raw material is dissolved in the organic solvent by heating while stirring the organic solvent.

At this time, it is important to select an appropriate solventAs an organic solvent. Specifically, a mixed solvent of a poor solvent and a good solvent containing the compound (a) is preferably used as the organic solvent. Thus, in the recrystallization (3) described later, crystals tend to grow slowly, and the particle size distribution is easily controlled appropriately (for example, as described in embodiment 2, D)₅₀And D₅₀/D_aveTo obtain suitably controlled) powder.

Examples of the poor solvent include: alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, and ethylcyclohexane; and aliphatic hydrocarbon solvents such as n-pentane, n-hexane, isohexane, n-heptane, n-octane, isooctane, and n-decane.

Examples of the good solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, methyl lactate, ethyl lactate, and butyl lactate.

The mixing ratio of the poor solvent and the good solvent is, for example, 99/1 to 50/50, preferably 95/5 to 75/25, and more preferably 95/5 to 80/20 in terms of mass ratio.

In the step 2, the organic solvent is heated to, for example, about 60 to 80 ℃. The raw materials are completely dissolved in the organic solvent by the heating and stirring. In other words, the amount of the raw material to be charged into the organic solvent is adjusted to such an extent that the raw material is completely dissolved when the organic solvent is heated to about 60 to 80 ℃ and is precipitated in the following step 3 (temperature reduction). The amount can be set as appropriate based on the solubility of the raw material, the organic solvent used, the heating temperature, and the like.

The amount of the raw material (the amount charged into the organic solvent) may be about 100g per 1000g of the organic solvent, but this amount is merely an example.

Step 3: cooling/addition of seed crystals/stirring

In the step 2, the organic solvent which is heated to about 60 to 80 ℃ and is completely dissolved in the raw material is slowly cooled to about 55 ℃ in about 30 minutes to 3 hours.

After cooling, adding the solid to an organic solventThe compound (A) in the form of a seed crystal. According to the findings of the present inventors, particularly in the case of using the poor solvent and the good solvent as the organic solvent, the particle size distribution can be appropriately controlled by using the seed crystal (for example, D in embodiment 2) ₅₀And D₅₀/D_aveControlled) compound (a).

The amount of the seed crystal added may be about 1/1000 to 1/100 mass% of the raw material dissolved in the organic solvent in step 2. The seed crystal is not particularly limited, and may be a solid compound (a). For example, the seed crystal obtained by the method described in the example of patent document 2 can be used. Further, a commercially available solid compound (a) may be used as a seed crystal.

After the seed crystal was added, the temperature was maintained at about 55 ℃, and the organic solvent was stirred in this state for about 30 minutes to 3 hours to precipitate crystals.

Step 4: cooling down

After the step 3, the organic solvent is slowly cooled for about 1 to 5 hours while being stirred until the temperature becomes about 30 to 40 ℃. Thereby, crystals are grown.

The obtained crystals are recovered by filtration under reduced pressure and dried under reduced pressure at about 20 to 50 ℃. In this way, a powder having a suitably controlled particle size distribution or the like can be obtained.

< method for producing solution >

A solution containing the compound represented by the general formula (a) can be produced using a solvent and the powder according to at least any one of embodiments 1 to 4. By using this solution, various low molecular compounds, oligomers, polymers, and the like can be produced.

In producing the solution, (i) the powder of at least any one of embodiments 1 to 4 may be directly added to the solvent and stirred or dissolved, and (ii) the powder of at least any one of embodiments 1 to 4 may be first pulverized to obtain a pulverized powder, and the pulverized powder may be added to the solvent and stirred or dissolved.

As described above, the powders according to embodiments 1 to 4 are excellent in industrial operability. For example, in embodiment 1, the mode particle diameter D_m75 to 150 μm, and thus has advantages of good filterability and short drying time for drying wet powder. On the other hand, in the mode particle diameter D_mWhen the particle size is relatively large, 75 to 150 μm, it may take a little time to dissolve the particles depending on the type of the solvent. Thus, it may be preferable to produce a solution as described in (ii) above.

The method of "micronization" is not particularly limited. A typical method for micronization is pulverization. Industrially, the pulverization can be carried out by a jet mill, a roll mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary ball mill, a bead mill or the like.

As another method for the pulverization, the powder of at least any one of embodiments 1 to 4 may be put into a solvent, and the undissolved powder may be taken out (for example, by filtration) before the powder is completely dissolved, to obtain a fine powder.

As another method for the refinement, a fine powder can be obtained by putting the powder of at least any one of embodiments 1 to 4 into a solvent in an amount that does not dissolve all the powder, and after the dissolution of the powder is saturated, taking out the undissolved powder. Alternatively, a solution in which undissolved powder is present may also be used directly.

When the miniaturization is performed, the degree of the miniaturization is not particularly limited. The degree of miniaturization can be determined in consideration of both the desired cost of miniaturization and the advantages of miniaturization (for example, the improvement of solubility described above). In one aspect, the method is to reduce the particle size before and after the step of micronizing (preferably pulverizing) the material D_aveThe fine particle size is 1/20 to 1/2, preferably 1/15 to 1/4. From D_aveFrom the viewpoint of the absolute value of (b), D is the amount of the finely (preferably pulverized) powder_avePreferably 0.1 to 15 μm, more preferably 0.5 to 10 μm.

The solvent to be used for producing the solution of the compound (a) may be appropriately selected depending on the purpose. The solvent to be used is not particularly limited, and the compound (a) may be dissolved. Specifically, it is possible to exemplify: amide solvents such as N, N-dimethylformamide, N-dimethylacetamide, N-methylformamide, hexamethylphosphoric triamide, and N-methyl-2-pyrrolidone; alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, and 2-methyl-2-propanol; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, diphenyl ether, dimethoxyethane, diethoxyethane, tetrahydrofuran, and dioxane 1-methoxy-2-propanol; ester-based solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and ethyl lactate; nitrile solvents such as acetonitrile, propionitrile, and benzonitrile; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and cumene; halogen-based solvents such as dichloromethane, chloroform, 1, 2-dichloroethane, and 1,1,2, 2-tetrachloroethane; lactone solvents of gamma-butyrolactone, gamma-valerolactone, delta-valerolactone and epsilon-caprolactone. The solvents may be used alone or in combination of two or more.

The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various configurations other than the above-described configurations may be adopted. The present invention is not limited to the above-described embodiments, and variations, improvements, and the like are included in the present invention within a range in which the object of the present invention can be achieved.

[ examples ]

The embodiments of the present invention will be described in detail based on examples and comparative examples. The invention is not to be considered as limited to the embodiments described herein, but is to be understood as being modified in all respects.

Examples 1 to 5 and comparative examples 1 to 6

Examples 1 to 5 and comparative examples 1 to 6 below are particularly used for examples and comparative examples for describing embodiment 1 in detail.

< example 1>

25.0g (74.4mmol) of BIS-AF powder manufactured by Central Glass was collected from a reagent bottle and placed in a 500mL borosilicate Glass container equipped with a stirrer and a cooling condenser. Subsequently, 225.0g of pure water was added to the vessel. Further, the temperature inside the vessel was raised to 95 ℃ while stirring.

During the temperature rise, the BIS-AF powder began to melt, and the inside of the container became a suspended state. The temperature was maintained at 95 ℃ and stirred for 1 hour in this state.

After 1 hour had elapsed, the stirring was temporarily stopped and the vessel was allowed to stand for observation. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

At this time, the BIS-AF concentration on the water layer side was measured. The concentration was about 1 mass%, and most of BIS-AF was not "dissolved" in water despite the high temperature of about 95 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly lower than 10[ g/100g ] at the melting temperature of the BIS-AF powder as the raw material.

Then, the internal temperature is slightly lowered from 95 ℃ and the mixture is stirred for 1 hour while maintaining the temperature of 92 to 94 ℃. Thus, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and collected by filtration under reduced pressure using a suction filter equipped with filter paper. After recovery, the column was washed with 75mL of pure water. The washed BIS-AF was dried at 75 ℃ under reduced pressure (1kPa or less) for 8 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 96% and 24.1 g.

< example 2>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 202.5g of pure water and 22.5g of methanol were added to the vessel, and the temperature inside the vessel was raised to 66 ℃ while stirring.

During the temperature rise, the BIS-AF powder starts to melt, and the inside of the container becomes a suspended state. The temperature was maintained in this state and stirred for 1.5 hours.

After 1.5 hours, the stirring was temporarily stopped and the vessel was left to stand, and the inside of the vessel was observed. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

At this time, the BIS-AF concentration on the water layer side was measured. The concentration was 2 mass% or less, and most of BIS-AF was not "dissolved" in water/methanol despite the high temperature of about 66 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly less than 10[ g/100g ] at a temperature at which the BIS-AF powder of the raw material would completely "melt".

Then, the mixture is stirred for 1 hour while maintaining the internal temperature at 60 to 65 ℃. Thus, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and collected by filtration under reduced pressure using a suction filter equipped with filter paper. After recovery, the column was washed with 75mL of pure water. The washed BIS-AF was dried at 80 ℃ under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The BIS-AF powder obtained after drying was 22.9g, yield 92%.

< example 3>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 112.5g of pure water and 12.5g of methanol were added to the vessel, and the temperature inside the vessel was raised to 66 ℃ while stirring.

During the temperature rise, the BIS-AF powder starts to melt, and the inside of the container becomes a suspended state. The temperature was maintained in this state, and stirring was carried out for 2 hours.

After 2 hours had elapsed, the stirring was temporarily stopped and the vessel was allowed to stand for observation. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

Then, the mixture is stirred for 1 hour while maintaining the internal temperature at 59 to 65 ℃. Thus, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and collected by filtration under reduced pressure using a suction filter equipped with a filter paper. After recovery, the precipitate was rinsed with 75mL of purified water. The washed BIS-AF was dried at 80 ℃ under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The BIS-AF powder obtained after drying was 23.4g, yield 94%.

< example 4>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 100.0g of pure water and 25.0g of methanol were added to the vessel, and the temperature inside the vessel was raised to 40 ℃ while stirring.

During the temperature rise, the BIS-AF powder began to melt, and the inside of the container became a suspended state. The temperature was maintained in this state and stirred for 2 hours.

At this time, the BIS-AF concentration on the water layer side was measured. At a concentration of 2 mass% or less, most of BIS-AF was not "dissolved" in water/methanol despite a temperature of about 40 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly less than 10[ g/100g ] at a temperature at which the BIS-AF powder of the raw material would completely "melt".

Then, the mixture is stirred for 1 hour while maintaining the internal temperature at 34 to 39 ℃. Thus, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 10 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and collected by filtration under reduced pressure using a suction filter equipped with a filter paper. After recovery, the column was washed with 75mL of pure water. The washed BIS-AF was dried at 80 ℃ under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 92% and 23.0 g.

< example 5>

100.0g (298mmol) of BIS-AF powder manufactured by Central Glass was collected from a reagent bottle and placed in a 2000mL borosilicate Glass container equipped with a stirrer and a cooling condenser. Next, 425.0g of pure water and 75.0g of methanol were added to the vessel. The temperature inside the vessel was raised to 55 ℃ while stirring.

During the temperature rise, the BIS-AF powder began to melt, and the inside of the container became a suspended state. The temperature was maintained at 55 ℃ and stirred for 1 hour in this state.

At this time, the BIS-AF concentration on the water layer side was measured. The concentration was about 1 mass%, and most of BIS-AF was not "dissolved" in water. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly lower than 10[ g/100g ] at the melting temperature of the BIS-AF powder as the raw material.

Subsequently, the internal temperature was slightly lowered from 55 ℃ and stirred for 1 hour while maintaining the temperature at 49 to 50 ℃. Thus, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and recovered by filtration under reduced pressure using a suction filter equipped with filter paper. After recovery, the column was washed with 300mL of pure water. The washed BIS-AF was dried at 75 ℃ under reduced pressure (1kPa or less) for 8 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 95.1g, 95%.

< comparative example 1>

Comparative example 1 is an example in which reduction of Ca ions was attempted by washing with water alone.

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a borosilicate glass container having a capacity of 300mL equipped with a stirrer. Next, 125.0g of pure water was added thereto, and the BIS-AF powder was washed while stirring at room temperature (about 20 ℃ C.) for 1 hour.

After the washing, the mixture was separated and collected by filtration under reduced pressure using a suction filter equipped with a filter paper.

Next, the mixture was dried at 80 ℃ and under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The BIS-AF powder obtained after drying was 24.0g, yield was 96%.

< comparative example 2>

Comparative example 2 is an example in which reduction of Ca ions by reprecipitation is attempted frequently in order to reduce the amount of metal in the crystalline compound.

200.0g of pure water was placed in a borosilicate glass container having a capacity of 300mL and equipped with a stirrer.

Then, 25.0g (74.4mmol) of BIS-AF powder collected from the same reagent bottle as in example 1 was dissolved in 50.0g of methanol to obtain a solution, and the solution was slowly dropped into a borosilicate glass container containing the pure water while rotating the stirrer. This caused the precipitation of a solid of BIS-AF.

The precipitated BIS-AF was collected by filtration under reduced pressure using a suction filter equipped with filter paper. Next, the mixture was dried at 80 ℃ under reduced pressure (1kPa or less) for 8 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 93% and 23.2 g.

< comparative example 3>

Comparative example 3 is an example of an attempt to reduce Ca ions by activated carbon, with reference to the description of patent document (CN 104529717A).

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a borosilicate glass container having a capacity of 300mL equipped with a stirrer. Subsequently, 50.0g of methanol and 2.0g of activated carbon (Shirasagi ANOX-1, product of Osaka Gas Chemical Co., Ltd.) were added to the vessel, and the mixture was stirred at room temperature (about 20 ℃ C.) for 5 hours.

After completion of the stirring, the activated carbon was removed by filtration using a suction filter equipped with a filter paper, and a methanol solution of BIS-AF was recovered. The metal ion concentration of the methanol solution was measured, and as a result, Na ion was 9ppm and Ca ion was 12 ppm.

Then, the methanol solution was slowly dropped into 200g of pure water, thereby reprecipitating BIS-AF. After precipitation of BIS-AF, BIS-AF was recovered by filtration under reduced pressure using a suction filter equipped with filter paper. Next, the mixture was dried at 80 ℃ under reduced pressure (1kPa or less) for 8 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 88% and 21.9 g.

< comparative example 4>

Comparative example 4 is an example obtained by replacing the activated carbon in comparative example 3 with an ion exchange resin.

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a borosilicate glass container having a capacity of 300mL equipped with a stirrer. Subsequently, 50.0g of methanol and 2.0g of an ion exchange resin (product name: Duolite C255LFH, manufactured by Sumika Chemtex Co., Ltd.) were added to the vessel, and the mixture was stirred at room temperature (about 20 ℃ C.) for 5 hours.

After completion of the stirring, the ion exchange resin was removed by filtration using a suction filter equipped with a filter paper, and the methanol solution of BIS-AF was recovered. When the metal ion concentration of the methanol solution was measured, Na ion was 3ppm and Ca ion was 2 ppm.

Then, the methanol solution was slowly dropped into 200g of pure water to reprecipitate BIS-AF. After precipitation of BIS-AF, BIS-AF was recovered by filtration under reduced pressure using a suction filter equipped with a filter paper. Next, the mixture was dried at 80 ℃ and under reduced pressure (1kPa or less) for 7 hours using a vacuum dryer.

The BIS-AF powder obtained after drying was 22.2g, yield was 89%.

< comparative example 5>

Comparative example 5 is an example in which the activated carbon in comparative example 3 was replaced with activated clay.

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 1, and placed in a borosilicate glass container having a capacity of 300mL equipped with a stirrer. Subsequently, 50.0g of methanol and 2.0g of activated clay (product name of Galleon Earth, manufactured by Kagaku Kogyo Co., Ltd.) were added to the vessel, and the mixture was stirred at room temperature (about 20 ℃ C.) for 5 hours.

After completion of the stirring, the activated clay was removed by filtration using a suction filter equipped with filter paper, and the methanol solution of BIS-AF was recovered. The metal ion concentration of the methanol solution was measured, and as a result, Na ion was 18ppm and Ca ion was 4 ppm.

(since the metal concentration in the methanol solution was significantly higher than that in comparative example 4, it is assumed that even if the metal could not be removed by the subsequent reprecipitation, the reprecipitation was not performed).

< comparative example 6>

Comparative example 6 is an example obtained with reference to the matters described in japanese patent laid-open No. 2007-a 246819.

In comparative example 6, a mixed solvent of water and alcohol (ethylene glycol) was used. However, comparative example 6 is fundamentally different from the present embodiment in that the BIS-AF powder as a raw material is completely dissolved in the mixed solvent (to form a uniform 1-layer) in a series of processes.

From the same reagent bottle as in example 1, 150g of BIS-AF powder was placed in a 2L borosilicate glass container equipped with a stirrer and a cooling condenser, and 300g of ethylene glycol and 700g of ion-exchanged water were poured into the container. Then, BIS-AF was dissolved while heating and stirring with an oil bath until the internal temperature of the flask was changed to 85 ℃. The temperature was maintained in this state, and stirring was performed for 1 hour. After 1 hour had elapsed, the stirring was temporarily stopped and the vessel was allowed to stand for observation. Thus, the solution was confirmed to be uniform.

Subsequently, the flask was cooled at a cooling rate of 10 ℃/hr while continuing the stirring until the internal temperature of the flask was changed to 25 ℃. Thus, crystallization began to precipitate slowly (recrystallization) at the same time as the temperature was decreased. The precipitated crystals were collected by filtration under reduced pressure (1kPa or less), and dried under reduced pressure at 60 ℃.

The BIS-AF powder obtained after drying was 137.0g, yield was 91%. Further, the Na ion concentration was 0.2ppm, and the Ca ion concentration was 0.3 ppm.

< measurement >

(particle size distribution)

The particle size distribution of a sample obtained by dispersing the obtained powdered BIS-AF in an n-decane solvent was measured by a particle size distribution analyzer SALD-2200 manufactured by Shimadzu corporation. For the measurement, BIS-AF was mixed with an n-decane solvent on a slide glass in advance to prepare a paste-like BIS-AF. Then, BIS-AF in paste form was added little by little to n-decane as a dispersion solvent, and the particle size distribution was measured by adjusting the amount of addition so that the absorbance value became 0.1L/(mol. cm) or less.

D was calculated by analyzing the obtained measurement results (particle size distribution)_mAnd the like.

(content of Ca, Na and Mg ions)

The contents of Ca, Na and Mg ions in the powder were determined by ion chromatography. The analytical method is detailed below.

First, 0.4g of each BIA-AF powder obtained in examples/comparative examples was dissolved in 2.0mL of t-butyl methyl ether to prepare a solution. This solution and 2.0mL of ultrapure water were placed in a separatory funnel, and the separatory funnel was vigorously shaken to extract the metal ion component on the ultrapure water (water layer) side. The separatory funnel was allowed to stand, and the side of the separated aqueous layer was used as an analysis sample liquid for analysis of the metal ion component.

The metal ion content of the analysis sample liquid was measured by using an ion chromatography apparatus (CS-2100) manufactured by Thermo Fisher Scientific. As the column, a separation column (Ion Pac CS16 (inner diameter 4 mm. times.250 mm)) and a guard column (Ion Pac CG16 (inner diameter 4 mm. times.100 mm)) were used. Further, 30mM methanesulfonic acid was used as an eluent, the flow rate of the eluent was 1.0 mL/min, and the temperature was set at 35 ℃.

The following table summarizes the information on the particle size distribution and the contents of Ca, Na, and Mg ions. Incidentally, in some of the comparative examples, since the content of the metal ion was significantly large, the particle size distribution was not measured (shown by n.d. in the table).

[ Table 1]

(content of alcohol)

In example 2, 1.00g of dried BIS-AF was dissolved in 1.00g of ethyl acetate and analyzed by gas chromatography. The methanol content was less than 100ppm based on the area of the peak other than ethyl acetate.

In comparative example 6, 1.00g of dried BIS-AF was dissolved in 1.00g of ethyl acetate and analyzed by gas chromatography. The ethylene glycol content was 500ppm based on the area of the peak other than ethyl acetate.

< evaluation >

The dispersion of BIS-AF powder in water was passed through a suction filter equipped with filter paper to separate the powder from the water. The filter performance (liquid removal) at this time was evaluated as follows.

Good: after the reduced pressure started, the dropping from the filter (bottom of funnel) disappeared rapidly.

Difference: the dropping from the filter (bottom of funnel) continued for a short time after the start of the depressurization.

The moisture content of the powder after suction filtration until the disappearance of the dropping from the filter (bottom of the funnel) was measured by the karl fischer method.

The evaluation results are summarized in the following table. Incidentally, as described above, since re-precipitation was not performed in comparative example 5, the evaluation results of liquid removal and water content (n.d.: No Data) were not found.

[ Table 2]

TABLE 2

As shown in Table 2, the powders of BIS-AF of examples 1 to 5 were excellent in filterability. Further, as a result of evaluation of the water-containing rate, it was found that the drying time was short when the powders of BIS-AF of examples 1 to 5 were dried. That is, the powders of BIS-AF of examples 1 to 5 were excellent in industrial workability.

Furthermore, the powders of BIS-AF of examples 1 to 5 had a Ca ion content of less than 1 ppm. Thus, the BIS-AF powders of examples 1 to 5 can be suitably used in various technical fields (for example, electronic device production).

Examples 2-1 to 2-4 and comparative examples 2-1 to 2-3

The following examples 2-1 to 2-4 and comparative examples 2-1 to 2-3 are particularly used for the examples and comparative examples that will explain the embodiment 2 in detail.

< example 2-1>

First, 200g of BIS-AF (manufactured by Central Glass) was placed in a 3L flask made of borosilicate Glass equipped with a stirring motor, a thermometer, and a cooling condenser, and 1800g of n-hexane and 200g of ethyl acetate were injected thereinto.

Then, BIS-AF was dissolved while heating and stirring with an oil bath until the internal temperature of the flask was changed to 65 ℃.

After the internal temperature of the flask reached 65 ℃ and the temperature was gradually decreased over 1 hour until the internal temperature became 55 ℃, 1g of BIS-AF (manufactured by Central Glass) was added as a seed crystal after the temperature was decreased, and the mixture was stirred for 1 hour in this state to precipitate the objective BIS-AF.

Then, the mixture was cooled for 2 hours until the internal temperature became 35 ℃, and the precipitated crystals were collected by filtration under reduced pressure. The recovered crystals were dried under reduced pressure at 30 ℃ to obtain 24g of powdered BIS-AF.

< examples 2 to 2>

First, 200g of BIS-AF (manufactured by Central Glass) was placed in a 3L flask made of borosilicate Glass equipped with a stirring motor, a thermometer, and a cooling condenser, and 1800g of n-hexane and 200g of ethyl acetate were charged therein.

After the internal temperature of the flask reached 65 ℃ and the temperature was gradually decreased over 2 hours until the internal temperature became 55 ℃, 1g of BIS-AF (manufactured by Central Glass) was added as a seed crystal after the temperature was decreased, and the mixture was stirred for 2 hours in this state to precipitate the objective BIS-AF.

Then, the mixture was cooled for 4 hours until the internal temperature became 35 ℃, and the precipitated crystals were collected by filtration under reduced pressure. The recovered crystals were dried under reduced pressure at 30 ℃ to obtain 27g of powdered BIS-AF.

< examples 2 to 3>

First, 200g of BIS-AF (manufactured by Central Glass) was placed in a 3L flask made of borosilicate Glass equipped with a stirring motor, a thermometer, and a cooling condenser, and 1800g of n-heptane and 200g of ethyl acetate were poured thereinto.

Then, the reaction mixture was cooled for 2 hours until the internal temperature became 35 ℃ and the precipitated crystals were collected by filtration under reduced pressure. The recovered crystals were dried under reduced pressure at 30 ℃ to obtain 23g of powdered BIS-AF.

< examples 2 to 4>

BIS-AF powder was obtained in the same manner as < example 5> described above.

< comparative example 2-1>

Comparative example 2-1 is an example in which a powder was produced by the method according to the example of patent document 2 (BIF-AF was precipitated by neutralization reaction).

200g of BIS-AF (manufactured by Central Glass) and 52g of sodium hydroxide were placed in a 3L flask made of borosilicate Glass equipped with a stirring motor and a thermometer. Then, 1800g of water was added and stirred while paying attention to the heat release, thereby obtaining a uniform solution (salt in which BIF-AF was dissolved).

Subsequently, the mixture was cooled in an ice bath until the internal temperature became 10 ℃, and then neutralized while dropping 136g of 35% hydrochloric acid water, thereby precipitating BIS-AF.

The precipitated crystals were recovered by filtration under reduced pressure and dried under reduced pressure at 60 ℃. 171g of powdered BIS-AF were thus obtained.

< comparative example 2-2>

Comparative example 2-2 is an example of producing a powder according to the method and conditions according to the example of patent document 1 (the main component of the solvent is water).

In a 2L flask made of borosilicate Glass and equipped with a stirring motor, a thermometer, and a cooling condenser, 150g of BIS-AF (manufactured by Central Glass Co., Ltd.) was placed, and 300g of ethylene glycol and 700g of ion-exchanged water were charged.

After the internal temperature of the flask reached 65 ℃, BIS-AF was precipitated while cooling at a cooling rate of 10 ℃/hr until the internal temperature of the flask was changed to 25 ℃.

The precipitated crystals were recovered by filtration under reduced pressure and dried under reduced pressure at 60 ℃. Thus, 135g of powdered BIS-AF was obtained.

< comparative examples 2 to 3>

Comparative examples 2 to 3 are examples in which powders were produced according to the method and conditions according to examples of patent document (CN104529717A) (BIS-AF was precipitated by reprecipitation).

800g of ion-exchanged water was poured into a 1L flask made of borosilicate glass equipped with a stirring motor and a thermometer. A solution prepared by dissolving 100g of BIS-AF (manufactured by Central Glass Co., Ltd.) in 100g of methanol was added dropwise thereto at an internal temperature of 20 to 23 ℃ and the flask was stirred to reprecipitate BIS-AF.

The precipitated crystals were recovered by filtration under reduced pressure and dried under reduced pressure at 60 ℃. 89g of powdered BIS-AF were thus obtained.

< various measurements/evaluations >

(particle size distribution)

The particle size distribution of a sample obtained by dispersing the obtained powdered BIS-AF in an n-decane solvent was measured by a particle size distribution analyzer SALD-2200 manufactured by Shimadzu corporation. For the measurement, BIS-AF paste was prepared by mixing BIS-AF with n-decane solvent on a glass slide in advance. Then, BIS-AF in paste form was added little by little to n-decane as a dispersion solvent, and the particle size distribution was measured by adjusting the amount of addition so that the absorbance value became 0.1L/(mol. cm) or less. D is calculated by analyzing the obtained measurement results ₅₀、D₉₀、D_aveAnd D_m。

The information on the particle size is shown in table 3.

[ Table 3]

TABLE 3

(evaluation of handling Properties: blocking)

50g of BIS-AF powder was placed in a 100mL polyethylene container with a lid and left at room temperature for 1 month. Then, the container was opened, and all of the BIS-AF powder was taken out, and the presence or absence of the blocking due to the aggregation of BIS-AF was visually confirmed.

The case where no blocking was observed was evaluated as good, and the case where blocking was observed as bad.

(operability: fluidity evaluation (funnel test))

60g of all BIS-AF powder was put into a funnel having an aperture of 150mm, a nozzle diameter of 12mm and a nozzle length of 22mm, and it was confirmed whether the powder could be naturally discharged. At this time, the case where all BIS-AF powders were naturally discharged was evaluated as good (good), and the case where all BIS-AF powders were not naturally discharged was evaluated as X (bad).

(operability: measurement of angle of repose)

A funnel having a funnel diameter of 150mm, a nozzle diameter of 12mm and a nozzle length of 22mm was used, and a sieve plate having a sieve opening of 0.5mm was placed on each funnel, and a horizontal table was placed at a position 4.5cm from the tip of the nozzle of the funnel toward the lower portion. Next, 50g of BIS-AF powder was put on a sieve plate, and the BIS-AF powder was dropped in the direction of the funnel nozzle by using a brush and deposited on a horizontal table. Then, the accumulated mountain-like powder was photographed, and the angle of repose was measured on the photograph. The smaller the angle of repose, the powder was more likely to flow smoothly, i.e., the workability was excellent.

(measurement of bulk Density (Loose bulk Density, tap bulk Density))

The bulk density was measured using a JIS (Japanese Industrial Standards) bulk specific gravity measuring instrument manufactured by a cartridge well chemical instrument. The bulk specific gravity measuring device is provided with a funnel with the caliber of 150mm, the diameter of a nozzle of 12mm and the length of the nozzle of 22 mm; the sieve pore on the funnel is a sieve plate with 0.5 mm; and a cylindrical 30mL receiving container at the lower part of the funnel nozzle. 50g of BIS-AF powder was taken out onto the sieve plate, and slowly dropped into the receiving container using a brush, thereby allowing it to fill naturally. After scraping the BIS-AF powder overflowing from the receiving container, the weight of the receiving container was measured, and the loose bulk density was calculated therefrom. When the BIS-AF powder was dropped, the powder was compressed and filled while gently tapping the lower part of the receiving container, and the tap bulk density was calculated from the obtained weight.

(evaluation of solvent solubility/insolubilization)

The BIS-AF powders of example 2-1 and comparative examples 2-1 to 2-3 were evaluated for solvent solubility by the following procedure.

(i) Comparison of dissolution rates in 40% aqueous methanol solution

10g of BIS-AF powder was weighed and placed in a 100mL flask made of borosilicate glass equipped with a stirrer and a thermometer. During stirring of powdered BIS-AF at a uniform speed, 40g of 40% methanol aqueous solution was rapidly injected. And then, stirring at a uniform speed, and completely dissolving the BIS-AF powder at 18-20 ℃.

The time taken from immediately after the addition of the aqueous methanol solution to the complete dissolution of the BIS-AF powder in the above-mentioned step was measured.

(ii) Comparison of dissolution rates in 10% aqueous sodium hydroxide solution

40g of a 10% aqueous sodium hydroxide solution was measured and placed in a 100mL flask made of borosilicate glass equipped with a stirrer and a thermometer. To a 10% aqueous solution of sodium hydroxide stirred at a uniform speed, 10g of BIS-AF powder was put in a little by little for 30 seconds. Then, the stirring was maintained at a uniform speed, and the cumulative time until the BIS-AF powder was completely dissolved at 18 to 20 ℃ was measured.

The results of various measurements/evaluations are shown in Table 4.

[ Table 4]

According to tables 3 and 4, the powders of examples 2-1 to 2-4 were inhibited from being agglomerated. In addition, the powder of examples 2-1 to 2-4 showed good results in the funnel test. Furthermore, the powders of examples 2-1 to 2-4 had smaller angles of repose than the powders of comparative examples 2-1 and 2-2. From these results, D can be understood₅₀50 to 100 μm, D₅₀/D_aveThe powder of the compound (A) is 1.1 to 1.5, and has good operability.

The powders of examples 2-1 to 2-4 had bulk densities (loose bulk density, tapped bulk density) higher than those of comparative examples 2-1 to 2-3. From this, it is also clear that the powder of examples 2-1 to 2-3 is excellent in handling property.

The powder of example 2-1 had good solvent solubility. From this, it was also found that the powder of example 2-1 was excellent in handling properties.

Examples 3-1 to 3-4 and comparative examples 3-1 to 3-3

The following examples 3-1 to 3-4 and comparative examples 3-1 to 3-3 are particularly used for the examples and comparative examples that will explain embodiment 3 in detail.

< example 3-1>

< examples 3 and 2>

After the internal temperature of the flask reached 65 ℃ and the temperature was gradually decreased over 2 hours until the internal temperature became 55 ℃, 1g of BIS-AF (manufactured by Central Glass) was added as a seed crystal after the temperature decrease, and the mixture was stirred for 2 hours in this state to precipitate the objective BIS-AF.

< examples 3 to 3>

< examples 3 to 4>

BIS-AF powder was obtained in the same manner as < example 5> described above.

< comparative example 3-1>

Comparative example 3-1 is an example of producing a powder by the method according to the example of patent document 2 (precipitation of BIF-AF by neutralization reaction).

200g of BIS-AF (manufactured by Central Glass) and 52g of sodium hydroxide were placed in a 3L flask made of borosilicate Glass and equipped with a stirring motor and a thermometer. Then, 1800g of water was added and stirred while paying attention to the heat release, thereby obtaining a uniform solution (salt in which BIF-AF was dissolved).

< comparative example 3-2>

Comparative example 3-2 is an example of producing a powder according to the method and conditions according to the example of patent document 1 (the main component of the solvent is water).

In a 2L flask made of borosilicate Glass and equipped with a stirring motor, a thermometer and a cooling condenser, 150g of BIS-AF (Central Glass) was placed, and 300g of ethylene glycol and 700g of ion exchange water were poured.

< comparative examples 3 to 3>

Comparative example 3-3 is an example of producing a powder (precipitation of BIS-AF by reprecipitation) according to the method and conditions according to the examples of patent document (CN 104529717A).

< various measurements/evaluations >

(particle size distribution)

The particle size distribution of a sample obtained by dispersing the obtained powdered BIS-AF in an n-decane solvent was measured by a particle size distribution analyzer SALD-2200 manufactured by Shimadzu corporation. For the measurement, BIS-AF paste was prepared by mixing BIS-AF with n-decane solvent on a glass slide in advance. Then, BIS-AF in paste form was added little by little to n-decane as a dispersion solvent, and the particle size distribution was measured by adjusting the amount of addition so that the absorbance value became 0.1L/(mol. cm) or less. D is calculated by analyzing the obtained measurement results₅₀、D₉₀、D_aveAnd D_m。

(measurement of repose Angle)

A funnel having a funnel diameter of 150mm, a nozzle diameter of 12mm and a nozzle length of 22mm was used, and a sieve plate having a sieve opening of 0.5mm was placed on each funnel, and a horizontal table was placed at a position 4.5cm from the tip of the nozzle of the funnel toward the lower portion. Next, 50g of BIS-AF powder was put on a sieve plate, and the BIS-AF powder was dropped in the direction of the funnel nozzle by using a brush and deposited on a horizontal table. Then, the accumulated mountain-like powder was photographed, and the angle of repose was measured on the photograph.

(measurement of bulk Density (Loose bulk Density, tap bulk Density))

The bulk density was measured using a JIS bulk specific gravity measuring instrument manufactured by mitsui chemical instruments. The bulk specific gravity measuring device is provided with funnels with funnel caliber of 150mm, nozzle diameter of 12mm and nozzle length of 22 mm; the sieve pore on the funnel is a sieve plate with the diameter of 0.5 mm; and a cylindrical 30mL receiving container at the lower part of the funnel nozzle. 50g of BIS-AF powder was taken onto the sieve plate, and slowly dropped into the receiving container using a brush, thereby allowing it to fill naturally. After scraping the BIS-AF powder overflowing from the receiving container, the weight of the receiving container was measured, and the loose bulk density was calculated therefrom. When the BIS-AF powder was dropped, the powder was compressed and filled while gently tapping the lower part of the receiving container, and the tap bulk density was calculated from the obtained weight.

(evaluation of blocking)

(evaluation of flowability: funnel test)

(evaluation of solvent solubility/insolubility)

The BIS-AF powders of example 3-1 and comparative examples 3-1 to 3-4 were evaluated for solvent solubility by the following procedure.

(i) Comparison of dissolution rates in 40% aqueous methanol solution

The time taken from immediately after the addition of the aqueous methanol solution to the completion of dissolution of the BIS-AF powder in the above-mentioned step was measured.

(ii) Comparison of dissolution rates in 10% aqueous sodium hydroxide solution

The above various information is shown in tables 5 and 6.

[ Table 5]

[ Table 6]

TABLE 6

According to tables 5 and 6, the powders of examples 3-1 to 3-4 were excellent in the results of the evaluations relating to the blocking and the funnel test. In addition, the powder of example 3-1 was good in solvent solubility. I.e. D₅₀The powder of the compound (A) having an angle of repose of 35 to 49 DEG and an average particle diameter of 50 to 100 μm is excellent in industrial workability.

Examples 4-1 to 4-5 and comparative examples 4-1 to 4-3

Examples 4-1 to 4-5 and comparative examples 4-1 to 4-3 below are particularly examples and comparative examples for describing embodiment 4 in detail.

< example 4-1>

25.0g (74.4mmol) of BIS-AF powder manufactured by Tokyo chemical industry Co., Ltd was collected from a reagent bottle and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 202.5g of pure water and 22.5g of methanol were added to the vessel, and the temperature inside the vessel was raised to 65 ℃ while stirring.

During the temperature rise, the BIS-AF powder began to melt, and the inside of the container became a suspended state. The temperature was maintained in this state and stirred for 1.5 hours.

After 1.5 hours, the stirring was temporarily stopped and the vessel was left to stand, and the inside of the vessel was visually observed. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

At this time, the BIS-AF concentration on the water layer side was measured by 19F-NMR (Nuclear Magnetic Resonance) using p-BIS (trifluoromethyl) benzene as an internal standard. At a concentration of 2 mass% or less, most of BIS-AF was not "dissolved" in water/methanol despite a high temperature of about 65 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly less than 10[ g/100g ] at a temperature at which the BIS-AF powder of the raw material would completely "melt".

Then, the mixture was stirred for 1 hour while maintaining the internal temperature at 60 to 65 ℃, and as a result, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

After cooling, the precipitated BIS-AF was separated and recovered by filtration under reduced pressure using a suction filter equipped with filter paper. After recovery, the precipitate was rinsed with 75mL of purified water. The washed BIS-AF was dried at 80 ℃ under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The BIS-AF powder obtained after drying was 22.9g, yield was 92%.

< examples 4 and 2>

BIS-AF powder was obtained in the same manner as in example 4-1, except that the amount of BIS-AF powder was changed to 100.0g (298mmol), the amount of pure water was changed to 810.0g, and the amount of methanol was changed to 90.0 g.

The BIS-AF powder obtained after drying was 94.6g, yield 95%.

After 1.5 hours had elapsed, the stirring was temporarily stopped and the vessel was left to stand, as in example 1, and the inside of the vessel was visually observed. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

At this time, the BIS-AF concentration on the water layer side was measured by 19F-NMR using p-BIS (trifluoromethyl) benzene as an internal standard. The concentration was 2 mass% or less, and most of BIS-AF was not "dissolved" in water/methanol despite the high temperature of about 65 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly less than 10[ g/100g ] at a temperature at which the BIS-AF powder of the raw material would completely "melt".

< examples 4 to 3>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 4-1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Subsequently, 225.0g of pure water was added to the vessel. Further, the temperature inside the vessel was raised to 95 ℃ while stirring.

After 1 hour had passed, the stirring was temporarily stopped and the vessel was left to stand, and the inside of the vessel was visually observed. As a result, it was confirmed that two phases, i.e., an aqueous layer and a melt of BIS-AF were present separately (incompletely mixed) in the container. Further, it was not confirmed that BIS-AF was not melted.

At this time, the BIS-AF concentration on the water layer side was measured by 19F-NMR using p-BIS (trifluoromethyl) benzene as an internal standard. The concentration was about 2 mass%, and most of BIS-AF was not "dissolved" in water even at a high temperature of about 95 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly lower than 10[ g/100g ] at the melting temperature of the BIS-AF powder as the raw material.

Then, the mixture was stirred for 1 hour while maintaining the internal temperature at 92 to 94 ℃, and as a result, crystals were precipitated. Then, the internal temperature was cooled to room temperature at a cooling rate of 15 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

The yield of BIS-AF powder obtained after drying was 96% and 24.1 g.

< examples 4 to 4>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 4-1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 112.5g of pure water and 12.5g of methanol were added to the vessel, and the temperature inside the vessel was raised to 65 ℃ while stirring.

During the temperature rise, the BIS-AF powder starts to melt, and the inside of the container becomes a suspended state. The temperature was maintained in this state, and stirring was performed for 1.5 hours.

After 1.5 hours had passed, the stirring was temporarily stopped and the vessel was left to stand for visual observation. As a result, it was confirmed that two phases, i.e., the aqueous layer and the melt of BIS-AF were present separately (incompletely mixed) in the vessel. In addition, unmelted BIS-AF was not confirmed.

After cooling, the precipitated BIS-AF was separated and recovered by filtration under reduced pressure using a suction filter equipped with filter paper. After recovery, the column was washed with 75mL of pure water. The washed BIS-AF was dried at 80 ℃ under reduced pressure (1kPa or less) for 6 hours using a vacuum dryer.

The yield of BIS-AF powder obtained after drying was 94% at 23.5 g.

< examples 4 to 5>

25.0g (74.4mmol) of BIS-AF powder was collected from the same reagent bottle as in example 4-1, and placed in a 500mL borosilicate glass container equipped with a stirrer and a cooling condenser. Then, 100.0g of pure water and 25.0g of methanol were added to the vessel, and the temperature inside the vessel was raised to 45 ℃ while stirring.

At this time, the BIS-AF concentration on the water layer side was measured by 19F-NMR using p-BIS (trifluoromethyl) benzene as an internal standard. At a concentration of 2 mass% or less, most of BIS-AF was not "dissolved" in water/methanol despite a temperature of about 45 ℃. That is, the solubility of BIS-AF in the aqueous dispersion medium is significantly less than 10[ g/100g ] at a temperature at which the BIS-AF powder of the raw material would completely "melt".

Then, the mixture was stirred for 1 hour while maintaining the internal temperature at 35 to 40 ℃ to precipitate crystals. Then, the internal temperature was cooled to room temperature at a cooling rate of 10 ℃ per 1 hour. The room temperature at this time was about 25 ℃.

The yield of BIS-AF powder obtained after drying was 96% and 24.1 g.

< comparative example 4-1>

BIS-AF (manufactured by Tokyo chemical industry Co., Ltd.) was collected from the reagent bottle.

< comparative example 4-2>

200g of pure water was poured into a 500L borosilicate glass container equipped with a stirrer, and stirring was started at room temperature (about 20 ℃). 25.0g of BIS-AF (manufactured by Tokyo chemical Co., Ltd.) obtained by dissolving 50g of methanol was slowly dropped into the solution through a dropping funnel, and then reprecipitation of BIS-AF was carried out.

After precipitation of BIS-AF, BIS-AF was recovered by filtration under reduced pressure using a suction filter equipped with filter paper. Then, the mixture was dried at 80 ℃ under reduced pressure for 8 hours using a vacuum dryer. The BIS-AF powder obtained after drying was 22.1g, yield 88%.

< comparative examples 4 to 3>

150g of BIS-AF (manufactured by Tokyo chemical industry Co., Ltd.) was placed in a 2L borosilicate glass container equipped with a stirrer and a cooling condenser, and 300g of ethylene glycol and 700g of ion exchange water were poured into the container. Then, BIS-AF was dissolved while heating and stirring with an oil bath until the internal temperature of the flask was changed to 85 ℃. The temperature was maintained in this state, the mixture was stirred for 1 hour, and after 1 hour, the stirring was temporarily stopped and the mixture was left to stand, and the inside of the vessel was visually observed, whereby it was confirmed that the solution was uniform.

Subsequently, the flask was cooled at a cooling rate of 10 ℃/hr while stirring until the internal temperature of the flask was changed to 25 ℃, and as a result, it was confirmed that crystals were precipitated during the cooling. The precipitated crystals were recovered by filtration under reduced pressure and dried under reduced pressure at 60 ℃. The yield of BIS-AF powder obtained after drying was 137g, 91%.

< measurement >

(X-ray diffraction (XRD) Spectroscopy)

The X-ray diffraction (XRD) spectrum of the powder is based on the above measurement method and measurement conditions.

The information on the X-ray diffraction spectrum is shown in table 7.

[ Table 7]

< evaluation >

(dissolution speed)

(i) Comparison of dissolution rates in 40% aqueous methanol (40% aqueous MeOH)

10g of BIS-AF powder was weighed and placed in a 100mL flask made of borosilicate glass equipped with a stirrer and a thermometer. During stirring of the powdered BIS-AF at a uniform speed (200rpm), 40g of a 40% aqueous methanol solution was rapidly injected. Then, stirring was performed at a uniform speed (200rpm) to completely dissolve the BIS-AF powder at 18 to 20 ℃.

The time taken from immediately after the addition of the aqueous methanol solution to the completion of dissolution of the BIS-AF powder in the above-mentioned step was measured. Complete dissolution of BIS-AF powder was confirmed by visual observation.

(ii) Comparison of dissolution rates in 10% aqueous sodium hydroxide solution (10% aqueous NaOH)

40g of a 10% aqueous sodium hydroxide solution was measured and placed in a 100mL flask made of borosilicate glass equipped with a stirrer and a thermometer. To a 10% aqueous solution of sodium hydroxide stirred at a uniform speed (200rpm), 10g of BIS-AF powder was gradually charged over 30 seconds. Then, the cumulative time from the start of addition of the BIS-AF powder to the complete dissolution of the BIS-AF powder at 18 to 20 ℃ was measured while maintaining the stirring at the uniform speed (200 rpm). Complete dissolution of BIS-AF powder was confirmed by visual observation.

(drying test)

The dispersion of BIS-AF powder in water was filtered through a filter equipped with filter paper to obtain BIS-AF powder wetted with water. The BIS-AF powder thus obtained was dried at 60 ℃ under 0.5KPa in a vacuum dryer manufactured by Yamato Scientific Co.Ltd, and the water content of the powder was measured.

10g of BIS-AF powder was charged, and the water content of the powder at 0.5kPa and 60 ℃ was measured at the time (0 hour) of starting drying, 0.5 hour later and 1 hour later by a volumetric titration Karl Fischer water content titrator (MKV-710B, manufactured by Kyoto electronics industries, Ltd.).

The evaluation results are summarized in the following table.

[ Table 8]

N/A represents "no data".

As shown in Table 8, the powders of BIS-AF of examples 4-1, 4-4 and 4-5 exhibited good dissolution rates. Further, as a result of evaluation of the water content, it was found that the drying time was short when the powders of BIS-AF of examples 4-1, 4-4 and 4-5 were dried. That is, the powders of BIS-AF of example 4-1 and the like were excellent in industrial workability.

In addition, the moisture absorption test was performed as follows for example 4-1.

(moisture absorption test)

10g of BIS-AF powder was weighed in a petri dish, and the water content of the BIS-AF powder was measured by a volumetric Karl Fischer water titrator (MKV-710B, manufactured by Kyoto electronics industries, Ltd.).

In addition, 10g of BIS-AF powder was weighed in a petri dish, and left to stand in a constant-temperature and constant-humidity tank at a temperature of 30 ℃ and a humidity of 98%, and after 24 hours, the water content of the BIS-AF powder was measured by a volumetric Karl Fischer water titrator (MKV-710B, manufactured by Kyoto electronics industries, Ltd.).

The evaluation results are shown in the following table.

[ Table 9]

As shown in Table 9, it was found that the powder of BIS-AF in example 4-1 did not change in water content even after 24 hours and did not readily absorb moisture. That is, the BIS-AF powder of example 4-1 was excellent in industrial operability.

This application claims priority based on japanese application laid-open No. 2019-178923 applied on 30.9.2019, japanese application laid-open No. 2019-178924 applied on 30.9.2019, japanese application laid-open No. 2019-238016 applied on 27.12.2019 and japanese application laid-open No. 2020-033388 applied on 28.2.2020, the disclosures of which are incorporated herein in their entireties.

Claims

1. A powder of a compound represented by the following general formula (A),

the content of Ca ions is less than 1ppm,

2. The powder according to claim 1,

the Na ion content is less than 1 ppm.

3. The powder according to claim 1 or 2,

d is the cumulative 50% diameter of the volume measured by laser diffraction scattering method₅₀When D is₅₀The value of (b) is 40 to 100 μm.

4. A powder according to any one of claims 1 to 3,

d is the cumulative 50% diameter of the volume basis measured by the laser diffraction scattering method₅₀D represents a volume-based cumulative 90% diameter measured by a laser diffraction/scattering method₉₀When the utility model is used, the water is discharged,

(D₉₀-D₅₀)/D₅₀the value of (A) is 1.3 to 1.7.

5. The powder according to any one of claims 1 to 4,

the alcohol content is 400ppm or less.

6. A powder of a compound represented by the following general formula (A),

D₅₀is 50 to 100 μm in diameter,

D₅₀/D_ave1.1 to 1.5 of a surfactant,

7. The powder according to claim 6,

mode particle diameter D measured by laser diffraction scattering method_m75 to 150 μm.

8. The powder according to claim 6 or 7,

d is the cumulative 90% diameter of the volume measured by laser diffraction scattering method₉₀When the temperature of the water is higher than the set temperature,

(D₉₀-D₅₀)/D₅₀the value of (A) is 1.3 to 1.7.

9. The powder according to any one of claims 6 to 8,

The loose bulk density is 0.50-0.75 g/cm³The tap bulk density is 0.76 to 0.90g/cm³。

10. A powder of a compound represented by the following general formula (A),

the angle of repose of the powder is 35 to 49 degrees,

11. The powder according to claim 10,

12. The powder according to claim 10 or 11,

(D₉₀-D₅₀)/D₅₀the value of (A) is 1.3 to 1.7.

13. The powder according to any one of claims 10 to 12,

the loose bulk density of the powder is defined as rho₁And the tap bulk density of the powder is defined as rho₂Time, rho₂/ρ₁Is 1.01 to 1.45.

14. A powder which is a powder of 2, 2-bis (4-hydroxyphenyl) hexafluoropropane,

The half-value width of a peak near 25.8 ° in the X-ray diffraction spectrum is 0.040 ° or more and 0.120 ° or less.

15. The powder according to claim 14,

the half-value width of a peak near 22.3 ° in the X-ray diffraction spectrum is 0.055 ° to 0.170 °.

16. The powder according to claim 14 or 15,

the half-value width of a peak near 22.3 ° 2 θ in the X-ray diffraction spectrum is 0.060 ° or more and 0.165 ° or less.

17. A powder according to any one of claims 14 to 16,

the half-value width of a peak near 23.7 ° 2 θ in the X-ray diffraction spectrum is 0.055 ° or more and 0.100 ° or less.

18. The powder according to any one of claims 14 to 17,

the half-value width of a peak near 23.7 ° 2 θ in the X-ray diffraction spectrum is 0.060 ° or more and 0.090 ° or less.

19. The powder according to any one of claims 14 to 18,

the half-value width of a peak in the vicinity of 25.8 ° 2 θ in the X-ray diffraction spectrum is 0.045 ° or more and 0.115 ° or less.

20. The powder according to any one of claims 14 to 19,

the half-value width of a peak in the vicinity of 25.8 ° 2 θ in the X-ray diffraction spectrum is 0.050 ° to 0.110 °.

21. A method for producing a powder of a compound represented by the following general formula (A), the method comprising the steps of:

a melting step of putting a raw material substance containing the compound represented by the general formula (a) and an aqueous dispersion medium into a container and heating the raw material substance to melt the raw material substance in the presence of the aqueous dispersion medium to obtain a non-uniform liquid containing a melt of the raw material substance and the aqueous dispersion medium;

in the melting step, the melting temperature T of the raw material substance₁The solubility of the compound represented by the general formula (A) in the aqueous dispersion medium is 10[ g/100g ]]In the following, the following description is given,

22. The method for producing a powder according to claim 21,

the aqueous dispersion medium substantially contains only water.

23. The method for producing a powder according to claim 21,

the aqueous dispersion medium contains water and an alcohol,

The alcohol content in the aqueous dispersion medium is 30% by mass or less.

24. The method for producing a powder according to any one of claims 21 to 23,

temperature T of the crystallization step₂Specific temperature T₁The temperature is 1-10 ℃ lower.

25. The method for producing a powder according to any one of claims 21 to 24,

the crystallization step is performed while stirring the heterogeneous liquid.

26. A method for producing a solution containing a compound represented by the following general formula (A),

the method comprises a step of obtaining a solution of the compound represented by the general formula (A) by using a solvent and the powder according to any one of claims 1 to 20,

27. The method for producing a solution according to claim 26, comprising a step of micronizing the powder.