JP2020164523A - Crystal polymorph of 9,9-bis(6-hydroxy-2-naphthyl)fluorene and method for producing the same - Google Patents

Abstract

To provide a novel polymorph of BNF (crystal polymorph) that has an excellent heat stability or storage stability in a high temperature environment, and to provide a method for producing the same.SOLUTION: By crystallizing BNF from a mixed solvent of aromatic hydrocarbons and at least one solvent selected from phenols and ketones, a crystalline polymorph δ having diffraction peaks at diffraction angles 2θ=9.6±0.2°, 20.6±0.2° and 21.3±0.2° in powder X-ray diffraction pattern is obtained. The crystalline polymorph δ may also have diffraction peaks at at least one angle selected from diffraction angles 2θ=9.2±0.2°, 9.8±0.2°, 17.1±0.2°, 23.3±0.2° and 23.8±0.2°.SELECTED DRAWING: Figure 7

Description

The present invention relates to novel polymorphs (or crystalline polymorphs) of 9,9-bis (6-hydroxy-2-naphthyl) fluorene.

Compounds having a 9,9-bisarylfluorene skeleton are excellent in optical properties such as high refractive index and thermal properties such as heat resistance, and are effectively used as resin raw materials and additives.

As a compound having a 9,9-bisarylfluorene skeleton, for example, Patent Document 1 describes 6,6- (9-fluorenelidene) -di (2-naphthol) [or 9,9-bis (6-hydroxy-2-). Naphthol) fluorene: also referred to as BNF] is disclosed, and the BNF includes three crystalline polyforms produced by a predetermined method, that is, crystalline polymorph α (hereinafter, also referred to as α crystal) and crystal. It is described that the polymorph β (hereinafter, also referred to as β crystal) and the crystalline polyform γ (hereinafter, also referred to as γ crystal) are present.

Japanese Unexamined Patent Publication No. 2012-20708

The α, β and γ crystals of BNF obtained by the method described in Patent Document 1 are derived from the 9,9-bisarylfluorene skeleton and have relatively high heat resistance, and the melting point of each crystal is , 213 ° C., 226 ° C. and 230 ° C., respectively.

However, depending on the usage environment or storage condition, the thermal stability may not be sufficient, which may limit the usage. Therefore, even higher thermal stability or storage stability in a high temperature environment is required.

Therefore, an object of the present invention is to provide a novel polymorph (crystal polyform) of BNF having excellent thermal stability or storage stability in a high temperature environment, and a method for producing the same.

As a result of diligent studies to achieve the above problems, the present inventors have extremely high melting points when BNF is crystallized from a specific crystallization solvent, unlike the α crystal, β crystal and γ crystal described in Patent Document 1. The present invention has been completed by finding that a novel crystalline polyform δ (hereinafter, also referred to as δ crystal) having the above can be obtained.

That is, the crystal polymorph δ of the present invention is a crystal polyform of 9,9-bis (6-hydroxy-2-naphthyl) fluorene (BNF), and in the powder X-ray diffraction pattern, the diffraction angle 2θ = 9. It has diffraction peaks at 6 ± 0.2 °, 20.6 ± 0.2 ° and 21.3 ± 0.2 °.

The crystalline polymorph δ further has diffraction angles 2θ = 9.2 ± 0.2 °, 9.8 ± 0.2 °, 17.1 ± 0.2 °, 23.3 ± 0.2 ° and 23. It may have diffraction peaks at at least one angle selected from 8.8 ± 0.2 °. Further, the crystalline polymorph δ further has a diffraction angle of 2θ = 13.3 ± 0.2 °, 14.5 ± 0.2 °, 15.5 ± 0.2 ° and 26.8 ± 0.2 °. It may have diffraction peaks at at least one angle selected from. The crystal polymorph δ may have the highest peak intensity at a diffraction angle of 2θ = 19.5 ± 0.2 °. Further, the crystalline polymorph δ may have a melting point of 264 ± 3 ° C.

The present invention crystallizes 9,9-bis (6-hydroxy-2-naphthyl) fluorene from a mixed solvent of aromatic hydrocarbons and at least one solvent selected from phenols, ketones and ethers. It also includes a method of analyzing and producing the crystalline polyform δ. In the above method, the ratio of aromatic hydrocarbons to the total amount of phenols, ketones and ethers may be about 70/30 to 90/10 of the former / latter (mass ratio). Further, in the above method, precipitation (or crystallization) may occur at −10 ° C. to 10 ° C.

The crystal polymorph δ of the present invention may be the following polymorph. That is, it is a crystalline polymorph of 9,9-bis (6-hydroxy-2-naphthyl) fluorene (BNF), and in the powder X-ray diffraction pattern, the diffraction angles are 2θ = 9.6 ± 0.2 ° and 21. It may have a diffraction peak at 3 ± 0.2 °. The crystalline polymorph δ further has diffraction angles 2θ = 9.2 ± 0.2 °, 9.8 ± 0.2 °, 17.1 ± 0.2 °, 23.3 ± 0.2 ° and 23. It may have diffraction peaks at at least one angle selected from 8.8 ± 0.2 °. Further, the crystalline polymorph δ has a diffraction angle of 2θ = 14.2 ± 0.2 °, 16.7 ± 0.2 °, 19.1 ± 0.2 °, and 19.5 ± 0.2 °. And may have diffraction peaks at at least one angle selected from 20.6 ± 0.2 °. The crystal polymorph δ may have the highest peak intensity at a diffraction angle of 2θ = 19.5 ± 0.2 °. Further, the crystalline polymorph δ may have a melting point of 264 ± 3 ° C. Furthermore, the present invention crystallizes 9,9-bis (6-hydroxy-2-naphthyl) fluorene from a mixed solvent of aromatic hydrocarbons and at least one solvent selected from phenols and ketones. It also includes a method for producing the crystalline polyform δ.

In addition, in this specification and claims, the number of carbon atoms may be indicated by C ₁ , C ₆ , C _{10, and the} like. For example, an alkyl group having 1 carbon atom is indicated by "C ₁ alkyl", and an aryl group having 6 to 10 carbon atoms is indicated by "C _6-10 aryl".

Since the crystalline polymorph δ of BNF of the present invention has an extremely high melting point, it is excellent in thermal stability or storage stability in a high temperature environment. Therefore, it can be widely used as an industrial product, an organic compound, a raw material for a resin, an additive for a resin, and the like.

FIG. 1 is a chart showing a powder X-ray diffraction pattern of BNF prepared as a raw material for obtaining a crystalline polymorph δ in Example 1. FIG. 2 is a chart showing a powder X-ray diffraction pattern of the crystal polymorph δ obtained in Example 1. FIG. 3 is a DSC chart of the crystalline polymorph δ obtained in Example 1, in which the solid line indicates DSC and the broken line indicates DDSC. FIG. 4 is a chart showing a powder X-ray diffraction pattern of the crystalline polymorph α obtained in Comparative Example 1. FIG. 5 is a chart showing a powder X-ray diffraction pattern of the crystalline polymorph β obtained in Comparative Example 2. FIG. 6 is a chart showing a powder X-ray diffraction pattern of the crystalline polymorph γ obtained in Comparative Example 3. FIG. 7 is a chart showing a powder X-ray diffraction pattern of the crystal polymorph δ obtained in Example 4. FIG. 8 is a chart showing a powder X-ray diffraction pattern of the crystal polymorph δ obtained in Example 6. FIG. 9 is a DSC chart of the crystalline polymorph δ obtained in Example 3, where the solid line indicates DSC and the broken line indicates DDSC. FIG. 10 is a DSC chart of the crystalline polymorph δ obtained in Example 4, where the solid line indicates DSC and the broken line indicates DDSC. FIG. 11 is a DSC chart of the crystalline polymorph δ obtained in Example 5, where the solid line indicates DSC and the broken line indicates DDSC. FIG. 12 is a DSC chart of the crystalline polymorph δ obtained in Example 6, in which the solid line indicates DSC and the broken line indicates DDSC. FIG. 13 is a DSC chart of the crystalline polymorph δ obtained in Example 7, where the solid line indicates DSC and the broken line indicates DDSC. FIG. 14 is a DSC chart of the mixture of crystalline polymorphs α and δ obtained in Example 8, where the solid line shows DSC and the broken line shows DDSC. FIG. 15 is a chart showing the powder X-ray diffraction pattern of the amorphous material obtained in Reference Example 1.

[Characteristics of crystalline polymorph δ]
The polymorph δ in the crystal form of the present invention is a crystal polyform of 9,9-bis (6-hydroxy-2-naphthyl) fluorene (BNF), and has a diffraction angle of 2θ in the powder X-ray diffraction pattern (XRD). = Has at least characteristic diffraction peaks at 9.6 ± 0.2 °, 20.6 ± 0.2 ° and 21.3 ± 0.2 °. Preferably, the diffraction angles 2θ = 9.2 ± 0.2 °, 9.8 ± 0.2 °, 17.1 ± 0.2 °, 23.3 ± 0.2 ° and 23.8 ± 0. Diffraction peaks characteristic of at least one angle selected from .2 °, more preferably step by step, at least two angles, at least three angles, at least four angles, and even more preferably all five angles. have.

Usually, the crystalline polymorph δ further has a diffraction angle of 2θ = 13.3 ± 0.2 °, 14.5 ± 0.2 °, 15.5 ± 0.2 ° and 26.8 ± 0.2 °. It often has diffraction peaks at at least one angle selected. Of these diffraction angles 2θ, preferably at least one angle selected from the diffraction angles 2θ = 14.5 ± 0.2 °, 15.5 ± 0.2 ° and 26.8 ± 0.2 °. More preferably, it has a diffraction peak at a diffraction angle of at least 2θ = 14.5 ± 0.2 °.

The crystalline polymorph δ further has a diffraction angle of 2θ = 12.4 ± 0.2 °, 13.9 ± 0.2 °, 14.2 ± 0.2 °, 15.1 ± 0.2 °, and so on. 17.5 ± 0.2 °, 18.6 ± 0.2 °, 19.1 ± 0.2 °, 19.5 ± 0.2 °, 24.7 ± 0.2 °, 26.4 ± 0 It may have diffraction peaks at at least one angle selected from .2 ° and 29.5 ± 0.2 °. Of these diffraction angles 2θ, preferably, the diffraction angles 2θ = 13.9 ± 0.2 °, 15.1 ± 0.2 °, 17.5 ± 0.2 °, and 24.7 ± 0.2 °. It has a diffraction peak at at least one angle selected from, more preferably at least one angle selected from diffraction angles 2θ = 17.5 ± 0.2 ° and 24.7 ± 0.2 °. ..

The polymorph δ has only to have a diffraction peak pattern as described above, the diffraction angle 2 [Theta] = 19.5 largest peak intensity to ± 0.2 ° I (integrated intensity I _s and / or peak heights I _It may or may not have the diffraction peak of _h ), but it may or may not have 17.5 ± 0.2 °, 20.6 ± 0.2 °, 21.3 ± 0.2 ° and 24. .7 is preferably intensity I of the diffraction peak of the selected angle from ± 0.2 ° (integrated intensity _{I s} and / or peak height _{I h)} is the largest, among others 20.6 of ± 0.2 ° It is preferable that the intensity I _{6 of the} diffraction peak (integral intensity I _6s and / or peak height I _6h ) is the largest. The integrated intensities at the peaks of these diffraction angles 2θ = 17.5 ± 0.2 °, 20.6 ± 0.2 °, 21.3 ± 0.2 ° and 24.7 ± 0.2 ° are shown in order. _Given I _5s , I _6s , I _7s and I _10s , the order (or relationship) of the integral strengths is usually I _6s ≥ I _5s , I _7s , I _10s (ie, I _6s is I _5s , I _7s and I _10s or more) is preferable.

In addition, in the present specification and claims, the description of the order of peak intensities, for example, "I _6s ≥ I _5s , I _7s , I _10s " means that I _6s is I _5s , I _7s, and I _10s or more. The order between the peak intensities described via ",", that is, the order between I _5s , I _7s , and I _10s in the above example is not particularly limited.

On the other hand, the diffraction angle 2θ = 9.6 ± 0.2 °, 21.3 ± 0.2 °, 9.2 ± 0.2 °, 9.8 ± 0.2 °, 23.3 ± 0.2 ° And assuming that the integrated intensities of the diffraction peaks at 23.8 ± 0.2 ° are I _2s , I _7s , I _1s , I _3s , I _8s and I _9s , respectively, the order (or relationship) of the integrated intensities is normal. , I _2s , I _7s ≧ I _1s , I _3s , I _8s , I _9s , preferably I _7s ≧ I _2s ≧ I _1s , I _3s , I _8s , I _9s .

Further, the order is preferably I _6s ≧ I _2s , I _7s .

The polymorphic body δ usually has at least a diffraction peak having a diffraction angle of 2θ = 20.6 ± 0.2 ° and a diffraction peak shown in Table 1 below. Further, in the polymorphic form δ, when the integrated intensity I _6s and the peak height I _6h at the diffraction angle 2θ = 20.6 ± 0.2 ° are set to “100”, the integrated intensity and the peak height are shown in Table 1 below. It can be shown in the above, and preferably has the powder X-ray diffraction pattern shown in FIG.

The powder X-ray diffraction pattern can be measured using a conventional powder X-ray diffractometer. The diffraction angle 2θ indicating the peak may change by about ± 0.2 ° or ± 0.1 ° depending on the measurement conditions and the like.

As shown in FIG. 4, the α crystal obtained by the method of Patent Document 1 has a diffraction angle of 2θ = 12.4 ± 0.2 ° and 14.3 ± 0.2 in the powder X-ray diffraction pattern. It shows characteristic peaks at °, 16.8 ± 0.2 °, 19.2 ± 0.2 °, 19.6 ± 0.2 °, and 22.1 ± 0.2 °. In addition, the peak with a diffraction angle of 2θ = 19.6 ± 0.2 ° is often the largest. In the diffraction pattern of α crystal, although there is a part similar to the pattern of δ crystal, the characteristic peak of δ crystal, that is, the diffraction angle 2θ = 9.6 ± 0.2 °, 20.6 ± 0.2 ° And 21.3 ± 0.2 ° do not have a diffraction peak, preferably diffraction angles 2θ = 9.2 ± 0.2 °, 9.8 ± 0.2 °, 17.1 ± 0.2. It also does not have diffraction peaks of °, 23.3 ± 0.2 ° and 23.8 ± 0.2 °, which is different from the diffraction pattern of delta crystals.

Further, as shown in FIG. 5, the β crystal obtained by the method of Patent Document 1 has a diffraction angle of 2θ = 11.9 ± 0.2 ° and 14.1 ± 0.2 in the powder X-ray diffraction pattern. Characteristic of °, 17.8 ± 0.2 °, 18.5 ± 0.2 °, 19.9 ± 0.2 °, 22.1 ± 0.2 °, 22.9 ± 0.2 ° Shows a peak. Of these peaks, the peak with a diffraction angle of 2θ = 17.8 ± 0.2 ° or 22.9 ± 0.2 ° is often large. Such a powder X-ray diffraction pattern is significantly different from the diffraction pattern of the δ crystal.

As shown in FIG. 6, the γ crystal obtained by the method of Patent Document 1 has a diffraction angle of 2θ = 6.0 ± 0.2 °, 17.4 ± 0.2 °, in a powder X-ray diffraction pattern. 17.9 ± 0.2 °, 18.5 ± 0.2 °, 21.1 ± 0.2 °, 21.8 ± 0.2 °, 22.7 ± 0.2 °, 23.6 ± 0 It shows a characteristic peak at .2 °. Such a powder X-ray diffraction pattern is also significantly different from the diffraction pattern of the δ crystal.

The crystalline polymorph δ of BNF of the present invention has a significantly higher melting point than the crystalline polyforms α, β and γ described in Patent Document 1, and when measured with a differential scanning calorimeter (DSC), it has a melting point. For example, it is 264 ± 5 ° C., preferably 264 ± 3 ° C., more preferably 264 ± 2 ° C. Therefore, the crystalline polymorph δ is excellent in thermal stability (or heat resistance) or storage stability in a high temperature environment. The melting point can be measured based on the peak top of the endothermic peak (or melting point) in differential scanning calorimetry (DSC).

[Manufacturing method of crystalline polymorph δ]
The crystalline polymorph δ uses a mixed solvent of aromatic hydrocarbons and at least one solvent selected from phenols, ketones and ethers as a crystallization solvent, and 9,9-bis from this crystallization solvent. It can be prepared by crystallizing (6-hydroxy-2-naphthyl) fluorene (BNF). A preferable crystallization solvent is a mixed solvent of aromatic hydrocarbons, phenols and ketones.

Examples of the aromatic hydrocarbons include benzene and alkylbenzene. Examples of alkylbenzene include mono- or tetra C _1-4 alkyl-benzene such as xylene, ethylbenzene, trimethylbenzene, ethyltoluene, propylbenzene and cumene.

These aromatic hydrocarbons can also be used alone or in combination of two or more. Among these aromatic hydrocarbons, mono- or tri-C _1-3 alkyl-benzene is preferable, di C _1-2 alkyl-benzene is more preferable, xylene is more preferable, and it is excellent in solubility. , O-xylene or m-xylene is preferred, and o-xylene is most preferred.

Examples of the phenols include C _6-12 phenols such as phenol, cresol, xylenol, naphthol, and methylnaphthol.

These phenols can also be used alone or in combination of two or more. Among these phenols, C _6-10 phenol is preferable, naphthol such as 1-naphthol and 2-naphthol is more preferable, and 2-naphthol is particularly preferable from the viewpoint of excellent solubility.

The ketones are usually chain ketones, for example, acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl isobutyl ketone (MIBK), diisopropyl ketone, butyl propyl ketone. C _3-8 ketone and the like can be mentioned.

These ketones can also be used alone or in combination of two or more. Among these ketones, C _4-7 ketone is preferable, and C _5-7 ketone such as methyl isobutyl ketone is more preferable from the viewpoint of solubility.

Examples of ethers include C _1-6 chain ethers such as diethyl ether and diisopropyl ether; and C _3-6 cyclic ethers such as tetrahydrofuran, tetrahydropyran and 1,4-dioxane.

These ethers can also be used alone or in combination of two or more. Among these ethers, cyclic ethers are preferable, and C _3-5 cyclic ethers such as 1,4-dioxane are more preferable from the viewpoint of solubility.

Typically, the crystallization solvent is mono or di C _1-2 alkyl-benzene and at least one solvent selected from C _6-12 phenol, C _4-7 ketone, and C _3-6 cyclic ether. Examples thereof include xylene such as o-xylene, naphthol such as 2-naphthol, C _5-7 ketone such as methylisobutyl ketone, and C _3-5 cyclic ether such as 1,4-dioxane. A mixed solvent with at least one solvent selected from the above, more preferably a mixed solvent of xylene such as o-xylene, naphthol such as 2-naphthol, and C _5-7 ketone such as methyl isobutyl ketone; Alternatively, it is a mixed solvent of xylene such as o-xylene and C _5-7 ketone such as methyl isobutyl ketone, and particularly in a mixed solvent of xylene such as o-xylene and C _5-7 ketone such as methyl isobutyl ketone. is there.

In the crystallization solvent, the mass ratio of aromatic hydrocarbons such as xylene to the total amount of phenols such as naphthol, ketones such as C _5-7 ketone and ethers such as cyclic ether is, for example, the former / the latter. = 1/99 to 99/1, and the preferred range is 10/90 to 97/3, 30/70 to 95/5, 50/50 to 95/5, 60 / in the following steps. It may be 40 to 90/10, 65/35 to 85/15, 70/30 to 80/20, 75/25 to 80/20, and in particular, it can be precipitated at a lower temperature to efficiently form δ crystals. From 70/30 to 90/10, preferably 75/25 to 88/12, and more preferably 80/20 to 85/15. If the total amount of phenols, ketones and ethers, which are good solvents for BNF, is too small, δ crystals may not be formed, and if it is too large, crystals may not be efficiently precipitated.

When the crystallization solvent contains both phenols such as naphthol and ketones such as C _5-7 ketone, the mass ratio of the phenols to the ketones is, for example, the former / the latter = 1/99 to 99 /. It may be about 1, and the preferable range is 5/95 to 90/10, 10/90 to 70/30, 15/85 to 60/40, 20/80 to 50/50, and so on. It is 25/75 to 45/55 and 30/70 to 40/60.

The crystallization solvent may contain other solvents different from the aromatic hydrocarbons, phenols and ketones. The other solvent may be a conventional organic solvent or the like, or water or the like. Water may be in the form of an aqueous solution, and typical aqueous solutions include aqueous solutions of inorganic acids such as hydrochloric acid and sulfuric acid, and the concentration of the aqueous solution is, for example, about 0.1 to 10% by mass. It may be. The ratio may be, for example, 30% by mass or less, usually 0 to 20% by mass, based on the whole crystallization solvent, and the preferable range is 10% by mass or less and 5% by mass in the following steps. Hereinafter, it is 1% by mass or less, 0.1% by mass or less, and more preferably 0% by mass, that is, substantially free of other solvents.

The ratio (or amount used) of the crystallization solvent is not particularly limited, and may be, for example, about 0.1 to 20 parts by mass with respect to 1 part by mass of the fluorene compound BNF (solid content equivalent), which is a preferable range. The amount is 0.5 to 15 parts by mass, 1 to 10 parts by mass, 2 to 7 parts by mass, 3 to 5 parts by mass, and 3.5 to 4.5 parts by mass.

The crystalline polymorph δ can be precipitated by dissolving BNF in the crystallization solvent and cooling the mixture. Usually, BNF can be precipitated or crystallized by heating, dissolving, and cooling the BNF in the crystallization solvent. After dissolution, if necessary, a predetermined amount of solvent may be distilled off under reduced pressure to adjust the amount of crystallization solvent within the above ratio range. Further, as the crystallization solvent, all the solvents may be added (or mixed) in advance before heating, and the crystallization solvent may be added stepwise, for example, after a part of the solvent is added and the temperature is raised to a predetermined temperature, the remaining solvent is added. May be added.

Further, BNF may be prepared by the method described in Patent Document 1, for example, 9-fluorenone and 2-naphthol (or β-naphthol) may be prepared by using an acid catalyst such as sulfuric acid and β-mercaptopropionic acid. It may be prepared by a conventional method such as a method of reacting in the presence of a co-catalyst. Further, BNF is, for example, an isolated fluorene compound regardless of whether it is in a crystalline form or an amorphous form such as a crystalline polymorphic form α, β or γ prepared by the method described in Patent Document 1. It may be dissolved in the crystallization solvent and crystallized, or in the synthesis reaction of BNF, after the reaction is completed, the solvent of the reaction mixture may be replaced with the crystallization solvent to crystallize the crystalline amorphous compound δ. .. For example, after neutralizing and washing the reaction mixture as necessary, the solvent or dispersion medium may be removed from the reaction mixture, and the residue may be dissolved in the crystallization solvent to crystallize the crystalline polymorph δ.

The temperature at which the BNF is dissolved in the crystallization solvent is a temperature below the boiling point of the solvent, for example, 30 to 200 ° C., preferably in a stepwise manner of 50 to 150 ° C., 60 to 130 ° C., 70 to 120 ° C. ° C., 80-110 ° C.

The obtained BNF solution is cooled to crystallize the crystalline polymorph δ. Crystallization may be carried out by quenching, allowing to cool or slowly cooling, and it seems that the crystalline polymorph δ can be obtained relatively easily by quenching. A typical cooling rate can be selected from, for example, a range of about 0.1 to 100 ° C./min, and the preferred range is 1 ° C./min or higher, 1 to 50 ° C./min, 3 to 30 in stages. ° C./min, 5-20 ° C./min, 7-15 ° C./min, 8-12 ° C./min, 9-11 ° C./min. Further, the lower the precipitation temperature (the temperature at which precipitation or crystallization starts) is adjusted, the easier it is to obtain the crystalline polymorphic δ. For example, it may be selected from a range of about 80 ° C. or lower. Stepwise, 70 ° C. or lower, 50 ° C. or lower, 30 ° C. or lower, 20 ° C. or lower, −10 ° C. to 20 ° C., −5 ° C. to 15 ° C., particularly preferably 10 ° C. or lower, 0 to 10 ° C. The ultimate cooling temperature is, for example, −10 ° C. to 30 ° C., preferably −5 ° C. to 20 ° C., and more preferably 0 to 10 ° C. The holding time at the ultimate cooling temperature is not particularly limited, and may be, for example, about 1 minute to 12 hours, preferably 0.5 to 6 hours, and more preferably 1 to 3 hours.

In the crystallization operation, if necessary, a seed crystal may be added, and the crystallization operation may be performed only once or repeated a plurality of times. Crystals produced by crystallization are usually filtered by filtration such as suction filtration, separated by a separation means such as centrifugation, and dried to obtain a crystal polymorph δ having a high melting point.

The drying may be reduced pressure drying, and the drying temperature may be, for example, about 50 to 200 ° C., and the preferred range is 80 to 160 ° C., 90 to 150 ° C., 100 in the following steps. The temperature is ~ 140 ° C., 110 to 130 ° C., and the temperature may be raised at one time to dry, but usually, the temperature is gradually raised and dried. The drying time may be, for example, about 1 hour to 1 week, preferably 1 to 3 days.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. Each evaluation method is as follows.

[Evaluation method]
(X-ray diffraction (XRD))
Using a powder X-ray diffractometer (“Fully automatic multipurpose horizontal X-ray diffractometer Smart Lab” manufactured by Rigaku Co., Ltd.), output 3 kW, radiation source (Cu tube), measurement angle 5 to 70 ° or 5 to 90 It was measured under the condition of °.

(Melting point)
Using a differential scanning calorimeter (“EXSTAR DSC6200” manufactured by SII Nanotechnology Co., Ltd.), the measurement was carried out under the conditions of a nitrogen atmosphere, a measurement temperature of 30 to 300 ° C., and a heating rate of 10 ° C./min. From the obtained DSC chart (DSC curve), the temperature of the peak top of the endothermic peak due to melting was determined as the melting point.

[Example 1]
(Preparation of BNF)
28.8 g of 99% 9-fluorenone and 69.2 g of β-naphthol, 0.43 ml of β-mercaptopropionic acid, 1,4-dioxane 40. In a 1 L glass container equipped with a stirrer, a cooler, and a thermometer. The reaction was carried out by charging 0 g, further adding 22.4 ml of 98 mass% sulfuric acid, and stirring at 60 ° C. for 6 hours. As a result of confirmation by HPLC, the residual amount of fluorenone was 0.1% or less. To the obtained reaction solution, 13.3 g of 1,4-dioxane, 200 g of o-xylene and 53.3 g of water were added, and then 53.3 g of 5% by mass aqueous sodium hydrogen carbonate solution (sodium hydrogen carbonate aqueous solution) was added to adjust the pH to 7. It was neutralized until it became, and the aqueous layer was removed. The obtained organic layer was heated to 80 ° C. and then washed 3 times with 80 g of water. The washed organic layer was concentrated under reduced pressure to obtain 9,9-bis (6-hydroxy-2-naphthyl) fluorene (BNF). It was confirmed by ^{1 1} H-NMR that the obtained compound was the target BNF.

The powder X-ray diffraction pattern of the obtained BNF (raw material of delta crystal) is shown in FIG.

X-ray diffraction peak (in parentheses, relative integral intensity; relative peak height): diffraction angle 2θ = 8.22 ° (43.01; 38.57), 10.99 ° (53.61; 49. 35), 11.97 ° (31.81; 38.5), 12.33 ° (28.17; 40.99), 12.59 ° (38.15; 39.84), 13.45 ° ( 14.78; 20.68), 13.72 ° (46.13; 34.48), 14.25 ° (15.39; 26.58), 14.51 ° (1.2; 5.15) , 15.50 ° (25.18; 34.76), 16.22 ° (34.33; 48.35), 16.66 ° (89.56; 88.09), 17.38 ° (27. 98; 22.08), 17.72 ° (74.81; 90.45), 19.13 ° (77.59; 65.6), 19.53 ° (37.68; 68.31), 20 .52 ° (88.03; 86.5), 21.53 ° (54.37; 23.92), 21.97 ° (100; 100), 22.78 ° (20.41; 14.85) , 23.08 ° (40.07; 41.07), 23.00 ° (17.31; 24.85), 25.35 ° (18.49; 24.29), 25.95 ° (13. 94; 21.02), 26.36 ° (10.43; 12.3), 26.82 ° (63.93; 67.12), 27.41 ° (34.45; 38.52), 27 .74 ° (8.75; 13.36), 28.17 ° (5.14; 7.38), 29.04 ° (6.52; 8.83), 29.58 ° (3.63; 8.75), 30.48 ° (15.37; 12.51), 31.90 ° (1.57; 3.7), 33.58 ° (2.79; 2.87), 37.83 ° (4.75; 5.21), 39.61 ° (0.98; 2.13), 40.62 ° (4.19; 3.94), 43.44 ° (13.91; 7. 47), 44.86 ° (4.15; 2.74), 46.54 ° (3.09; 0.84), 53.16 ° (2.74; 1.97), 56.82 ° ( 1.44; 0.46), 58.97 ° (1.06; 0.36).

It is presumed that the obtained BNF is a mixture (or mixture) of α crystals and β crystals.

(Preparation of crystalline polymorph δ of BNF)
15 g of o-xylene and 1.5 g of 2-naphthol were mixed with 5 g of BNF, the temperature was raised to 100 ° C., and then 3 g of methyl isobutyl ketone (MIBK) was added and dissolved. Then, the crystals were precipitated by cooling at 10 ° C./min and ice-cooling at 10 ° C. or lower for 2 hours (after reaching 10 ° C. by cooling, holding in ice in a temperature range of 0 to 10 ° C. for 2 hours). .. The crystals recovered by suction filtration were washed with o-xylene, dried under reduced pressure at 90 ° C. for 1 day, and then dried under reduced pressure at 120 ° C. for 1 day to obtain a crystal polyform δ (δ crystal) of BNF.

The powder X-ray diffraction pattern of the obtained δ crystal is shown in FIG.

X-ray diffraction peak (in parentheses, relative integral intensity; relative peak height): diffraction angle 2θ = 9.23 ° (23.1; 21.3), 9.60 ° (50.2; 40. 5), 9.82 ° (32.4; 26.4), 12.35 ° (46.3; 41.5), 13.25 ° (27.2; 18.1), 13.91 ° ( 38.6; 34.4), 14.17 ° (66.2; 57.1), 14.52 ° (58.5; 40.6), 15.13 ° (31.1; 23.5) , 15.51 ° (37.5; 43.6), 17.13 ° (32.7; 34.4), 17.54 ° (59.3; 56.3), 18.56 ° (21. 1; 25.1), 19.07 ° (86.7; 64.6), 19.53 ° (124.8; 112.8), 20.63 ° (100; 100), 21.28 ° ( 55.5; 46.2), 23.31 ° (29.2; 26.4), 23.75 ° (20.8; 15.3), 24.69 ° (55.4; 37.0) , 26.35 ° (49.4; 34.9), 26.77 ° (38.4; 34.5), 29.51 ° (37.2; 25.5).

The melting point of the obtained delta crystal was 264.4 ° C. The DSC chart of the obtained δ crystal is shown in FIG.

[Example 2]
Delta crystals of BNF were obtained in the same manner as in Example 1 except that 197 g of o-xylene, 20 g of 2-naphthol and 39 g of MIBK were added to 66 g of BNF and dissolved by heating at 88 ° C. The powder X-ray diffraction pattern of the obtained δ crystal was the same as the diffraction pattern of the δ crystal obtained in Example 1 (FIG. 2). It was found that δ crystals could be obtained even if MIBK was added in advance before the temperature was raised. The melting point was 263.9 ° C.

[Comparative Example 1] α crystal described in Patent Document 1 A crystal polymorph α (α crystal) of BNF was obtained according to Example 1 of Patent Document 1. Since the crystals (α crystals) started to precipitate when toluene was added after removing o-xylene from the organic layer, the precipitation temperature of the crystals was 60 ° C. or higher. The powder X-ray diffraction pattern of the obtained α crystal is shown in FIG.

X-ray diffraction peak (in parentheses, relative peak height): Diffraction angle 2θ = 7.12 ° (18.86), 8.22 ° (34.91), 10.90 ° (20.75) , 12.40 ° (43.55), 14.30 ° (52.32), 16.78 ° (86.54), 19.18 ° (65.79), 19.64 ° (100.00) , 22.12 ° (56.71), 22.82 ° (41.05), 22.90 ° (41.05), 25.08 ° (36.10), 26.50 ° (32.02) , 27.82 ° (21.93), 29.62 ° (23.38), 32.02 ° (16.93).

The melting point of the obtained α crystal was 213 ° C.

[Comparative Example 2] β crystal described in Patent Document 1 A crystal polymorph β (β crystal) of BNF was obtained according to Example 3 of Patent Document 1. The powder X-ray diffraction pattern of the obtained β crystal is shown in FIG.

X-ray diffraction peak (in parentheses, relative peak height): Diffraction angle 2θ = 5.88 ° (30.96), 10.86 ° (41.56), 11.92 ° (59.38) , 11.94 ° (59.38), 14.06 ° (68.76), 17.84 ° (88.74), 18.48 ° (80.96), 19.92 ° (86.59). , 21.88 ° (65.95), 22.06 ° (61.91), 22.92 ° (100.00), 27.90 ° (46.53).

The melting point of the obtained β crystal was 226 ° C.

[Comparative Example 3] γ crystal described in Patent Document 1 A crystal polymorph γ (γ crystal) of BNF was obtained according to Reference Example 1 of Patent Document 1. The powder X-ray diffraction pattern of the obtained γ crystal is shown in FIG.

X-ray diffraction peak (in parentheses, relative integral intensity; relative peak height): Diffraction angle 2θ = 6.00 ° (100.00), 12.16 ° (29.78), 15.12 ° ( 37.04), 16.50 ° (44.21), 17.40 ° (69.14), 17.92 ° (53.47), 18.46 ° (53.47), 18.50 ° ( 53.47), 19.14 ° (46.30), 21.08 ° (56.79), 21.84 ° (59.88), 22.68 ° (52.16), 23.62 ° ( 53.47), 24.74 ° (40.59), 27.36 ° (35.96).

The melting point of the obtained γ crystal was 230 ° C.

Table 2 shows the characteristics of the polymorphs obtained in Example 1 and Comparative Examples 1 to 3.

As is clear from Table 2, it was found that the delta crystal obtained in Example 1 exhibited a melting point as high as about 30 to 50 ° C. as compared with Comparative Example.

[Examples 3 to 7]
Each component shown in Table 3 was added to the vial, mixed, and dissolved by raising the temperature to the dissolution temperature shown in Table 3. As the BNF, BNF (a mixture of α and β crystals) prepared in the same manner as in Example 1 (Preparation of BNF) was used. Then, the obtained solution was cooled at 10 ° C./min and ice-cooled at 10 ° C. or lower for 2 hours (after reaching 10 ° C. by cooling, kept in the temperature range of 0 to 10 ° C. with ice for 2 hours). Crystals were precipitated. The crystals recovered by suction filtration were washed with o-xylene, dried under reduced pressure at 90 ° C. for 1 day, and then dried under reduced pressure at 120 ° C. for 1 day to obtain BNF crystals.

The powder X-ray diffraction pattern of the crystal obtained in Example 4 is shown in FIG. 7, the powder X-ray diffraction pattern of the crystal obtained in Example 6 is shown in FIG. 8, and the main diffraction peaks are shown below. The melting points of each crystal are shown in Table 3, and the DSC charts are shown in FIGS. 9 to 13.

X-ray diffraction peak of the crystal obtained in Example 4 (in parentheses, relative integral intensity; relative peak height): diffraction angle 2θ = 9.25 ° (25.4; 17.6), 9. 59 ° (40.9; 35.6), 9.82 ° (18.7; 20.5), 12.32 ° (8.0; 7.0), 13.27 ° (20.0; 18) .3), 13.95 ° (34.0; 31.5), 14.17 ° (13.8; 22.1), 14.60 ° (32.4; 20.6), 15.12 ° (25.5; 22.2), 15.52 ° (28.1; 33.9), 17.13 ° (55.4; 41.1), 17.53 ° (49.0; 56.7) ), 18.54 ° (14.0; 16.9), 18.89 ° (10.5; 10.9), 19.52 ° (8.7; 8.1), 20.62 ° (100) .0; 100.0), 21.26 ° (64.9; 51.9), 23.23 ° (25.2; 24.4), 23.77 ° (21.7; 21.8), 24.54 ° (69.1; 42.9), 26.35 ° (25.0; 16.9), 26.80 ° (31.9; 29.8), 29.48 ° (15.4) 10.2).

X-ray diffraction peak of the crystal obtained in Example 6 (in parentheses, relative integral intensity; relative peak height): diffraction angle 2θ = 9.20 ° (22.7; 14.9), 9. 54 ° (37.3; 29.9), 9.78 ° (21.7; 20.3), 12.50 ° (10.3; 7.3), 13.26 ° (36.8; 24) .6), 13.87 ° (39.4; 30.6), 14.10 ° (29.8; 29.9), 14.53 ° (39.1; 30.4), 15.07 ° (33.4; 29.8), 15.46 ° (46.2; 43.6), 17.15 ° (41.6; 41.2), 17.49 ° (74.1; 69.0) ), 18.51 ° (19.7; 21.4), 18.87 ° (8.8; 9.1), 19.76 ° (7.8; 3.8), 20.58 ° (100) .0; 100.0), 21.22 ° (71.8; 53.9), 23.15 ° (36.2; 26.1), 23.71 ° (14.7; 18.8), 24.52 ° (62.4; 40.3), 26.31 ° (19.6; 15.1), 26.72 ° (27.5; 29.5), 29.34 ° (12.7) 9.6).

[Example 8]
90 g of BNF (mixture of α crystal and β crystal), 260 g of o-xylene, 75 g of 1,4-dioxane, and 33 g of 2-naphthol prepared in the same manner as in Example 1 (Preparation of BNF) in a 1 L eggplant flask. Was added and dissolved at 80 ° C., and then 245 g of the solvent was distilled off with an evaporator. The evaporator was operated under the conditions of 70 ° C., 40 to 60 Torr, and 30 minutes. 260 g of o-xylene heated to 70 ° C. was added to the residual liquid, and it was confirmed that there was no precipitation. The mixture was stirred while being held at 70 ° C., and when rapid precipitation of crystals was confirmed, the mixture was held at 70 ° C. for 30 minutes. The precipitated crystals were suction-filtered, washed with o-xylene, and dried under reduced pressure at 80 ° C. for 2 days to obtain BNF crystals.

The melting points of the crystals obtained in Example 8 are shown in Table 3, and the DSC chart is shown in FIG. From these results, it is presumed that the crystal obtained in Example 8 is a mixture (or mixed crystal) of α crystal and δ crystal.

As is clear from Table 3, at least one selected from aromatic hydrocarbons such as o-xylene and 2-naphthol (phenols), MIBK (ketones), and 1,4-dioxane (ethers). It was found that δ crystals were obtained by crystallization with a crystallization solvent containing a seed component.

Further, from Examples 2 and 3, it seems that the dissolution temperature does not affect the formation of δ crystals so much, but in Example 8 where the precipitation temperature is high, α crystals are mixed, so that in Examples 1 to 7. As described above, it is considered that the lower the precipitation temperature, the easier it is to form δ crystals.

[Reference example 1]
The delta crystal obtained in Example 1 was heated and melted in a heat block at 280 ° C. and then cooled at room temperature to obtain an amorphous BNF. When the obtained amorphous body was analyzed by XRD, a halo pattern was confirmed as shown in FIG.

Since the polymorphic form δ of BNF of the present invention has an extremely high melting point, it is excellent in thermal stability (or heat resistance) or storage stability in a high temperature environment. In addition, since it has a 9,9-bisarylfluorene skeleton, it is excellent in various properties such as optical properties, heat resistance, water resistance, moisture resistance, chemical resistance, electrical properties, mechanical properties, and dimensional stability. .. Therefore, it can be suitably used as a raw material for industrial products, organic synthesis, resin synthesis, etc., and also as an additive (or resin additive) such as a heat resistance improver, a refractive index improver, and an epoxy resin curing agent. it can.

Further, when used as a resin raw material, excellent properties such as high heat resistance, high crosslinkability, high refractive index, high transparency, and low linear expansion coefficient can be efficiently imparted to the resin. Examples of such resins include epoxy resins, thermosetting resins such as (meth) acrylic resins (or polyfunctional (meth) acrylates), and thermoplastic resins such as polyester resins, polycarbonate resins, and polyurethane resins. Can be mentioned. The epoxy resin is suitable for applications that require the above characteristics, such as semiconductor encapsulants and electrical substrates. Further, the (meth) acrylic resin is useful for optical material applications such as optical overcoating agents, hard coating agents, antireflection films, spectacle lenses, optical fibers, optical waveguides, holograms and the like. In addition, the thermoplastic resin can be used as a molding material for optical members, heat-resistant members, and the like.

Claims (7)

A crystalline polymorph of 9,9-bis (6-hydroxy-2-naphthyl) fluorene, which has a diffraction angle of 2θ = 9.6 ± 0.2 °, 20.6 ± 0.2 in a powder X-ray diffraction pattern. Crystal polymorph δ with diffraction peaks at ° and 21.3 ± 0.2 °. Furthermore, the diffraction angles 2θ = 9.2 ± 0.2 °, 9.8 ± 0.2 °, 17.1 ± 0.2 °, 23.3 ± 0.2 ° and 23.8 ± 0.2 °. The crystalline polymorph δ according to claim 1, which has a diffraction peak at at least one angle selected from. Further, at least one angle selected from diffraction angles 2θ = 13.3 ± 0.2 °, 14.5 ± 0.2 °, 15.5 ± 0.2 ° and 26.8 ± 0.2 °. The crystalline polymorph δ according to claim 1 or 2, which has a diffraction peak. The crystalline polymorph δ according to any one of claims 1 to 3, which has a melting point of 264 ± 3 ° C. 9,9-Bis (6-hydroxy-2-naphthyl) fluorene is crystallized from a mixed solvent of aromatic hydrocarbons and at least one solvent selected from phenols, ketones and ethers, and claimed. Item 8. The method for producing a crystalline polyform δ according to any one of Items 1 to 4. The method according to claim 5, wherein the ratio of the aromatic hydrocarbons to the total amount of phenols, ketones and ethers is the former / latter (mass ratio) = 70/30 to 90/10. The method according to claim 5 or 6, wherein precipitation is performed at −10 ° C. to 10 ° C.

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