JP2009249504A - Light-emitting material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting material which excels in durability, absorbs near-UV and blue light and emits light in a high efficiency, and in addition gives a multicolor emission. <P>SOLUTION: The light-emitting material contains a Si-based polymer containing a tetraphenylpyrene skeleton which is obtained by polymerizing an organic silane precursor represented by formula (2), a surfactant and a light-emitting compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting material, and more particularly to a light emitting material containing a polymer of an organosilicon compound.

  Organic light-emitting materials can be classified into low-molecular and high-molecular materials. Low-molecular light-emitting materials include aromatic fluorescent dyes such as anthracenes, benzenes, and biphenyls, aluminum complexes, iridium complexes, and rare earths. Examples of the polymer light emitting material include polyphenylene vinylenes, polyfluorenes, polythiophenes, and dye-containing non-conjugated polymers. However, conventional organic light-emitting materials have a problem that concentration quenching and emission color change due to interaction between molecules are large, and sufficient light emission luminance and light emission efficiency cannot be obtained. In addition, the lifetime of organic light emitting materials is generally shorter than that of other light emitting materials, and it has been difficult to maintain stable light emission characteristics over a long period of time. Furthermore, in recent years, high-efficiency light-emitting diodes having a light-emitting region in the near-ultraviolet region of 350 to 410 nm or a blue light region of 430 to 500 nm have been developed, and a light-emitting material that can effectively use these lights is demanded. .

  In order to solve these problems, Japanese Patent Application Laid-Open No. 2002-63888 (Patent Document 1) discloses an organic phosphor (luminescent material) containing a compound having a tetraphenylpyrene skeleton, and JP-A-2003-234190 (Patent Document 2) and JP-A-2006-269670 (Patent Document 3) disclose an organic thin film layer (light-emitting layer) containing a 1,3,6,8-tetraphenylpyrene compound. ) Is disclosed. However, these compounds having a tetraphenylpyrene skeleton are low molecular weight compounds.

  C.-H. Chen et al., J. Phys. Chem. B, 2005, 109, 17887-17891 (Non-patent Document 1) include an organosilane compound having an oligophenylene vinylene skeleton or an oligothiophene skeleton. An organic silica composite material synthesized by using two or more types is disclosed, and its light emission characteristics and energy transfer characteristics are also disclosed. However, this organic silica composite material does not contain a surfactant or other light-emitting compound, and no mesostructure is formed in the organic silica.

  Further, M. Ogawa et al., Chem. Mater., 1998, Vol. 10, p. 1382-1385 (Non-Patent Document 2) describes a surfactant in a system in which pyrene is introduced into pores of mesoporous silica. It is disclosed that the presence of pyrene inhibits the association of pyrene even at a high concentration, and concentration quenching hardly occurs. However, no organic group is introduced into the mesoporous silica, the mesoporous silica itself does not act as a light-emitting substance, and there is no energy transfer from mesoporous silica to pyrene.

Further, PN Minoofar et al., J. Am. Chem. Soc., 2005, 127, 2656-2665 (Non-Patent Document 3) describes mesopores from lanthanoid complexes immobilized in mesoporous silica structures. It is disclosed that energy is transferred to the internal rhodamine dye. However, the excitation wavelength of the lanthanoid complex is 330 nm, and it is difficult to use near ultraviolet light or blue light.
JP 2002-63988 A JP 2003-234190 A JP 2006-269670 A Chih-Hsien Chen et al., J. Phys. Chem. B, 2005, 109, 17887-17891. M. Ogawa et al., Chem. Mater., 1998, 10: 1382-1385. PN Minoofar et al., J. Am. Chem. Soc., 2005, 127, 2656-2665.

  This invention is made | formed in view of the subject which the said prior art has, is excellent in durability, absorbs near-ultraviolet rays (350-410 nm) and blue light (430-500 nm), emits light with high efficiency, An object is to provide a light emitting material that emits multicolor light.

  As a result of intensive studies to achieve the above object, the present inventors have used a polymer of an organosilicon compound having a tetraphenylpyrene skeleton or a derivative skeleton thereof, a surfactant, and a luminescent compound in combination. Thus, the light-emitting material containing these has excellent durability, absorbs near ultraviolet rays and blue light, emits light with high efficiency, and emits multicolor light, and has completed the present invention. .

  That is, the luminescent material of the present invention has the following formula (1):

(In the formula (1), Ar independently represents one selected from the group consisting of a phenylene group, a biphenylylene group and a naphthylene group, and L each independently represents an ether group, a thioether group, a carbonyl group, a carbonate group, It represents a divalent aliphatic organic group, an alkylene group or a single bond containing at least one group selected from the group consisting of an amino group, an amide group and a urethane group.)
It contains the polymer of the organosilicon compound which has a repeating unit represented by these, surfactant, and a luminescent compound, It is characterized by the above-mentioned.

  As the polymer of the organosilicon compound, those having a meso structure are preferable, and those having an absorption band at a wavelength of 350 to 410 nm or 430 to 500 nm are preferable. Furthermore, the luminescent material of the present invention preferably contains at least one selected from the group consisting of a polymerization inhibitor and an antioxidant as necessary.

  The reason why the light emitting material of the present invention is excellent in durability, absorbs near ultraviolet rays and blue light, emits light with high efficiency, and emits multicolor light is not necessarily clear. We infer as follows. That is, by introducing a sterically bulky tetraphenylpyrenyl skeleton or a derivative skeleton thereof into a polymer of an organosilicon compound, the durability of the luminescent material is improved and the interaction between molecules is suppressed. It is presumed that it will be possible to efficiently absorb near ultraviolet rays and blue light and emit light. In addition, by using a polymer of an organosilicon compound having a tetraphenylpyrenyl skeleton or a derivative skeleton thereof and a luminescent compound, light energy collected by the polymer of the organosilicon compound is transferred to the luminescent compound. It is assumed that multicolor emission is possible when the emission wavelength region of the polymer of the organosilicon compound and the emission compound are different. Furthermore, at this time, it is presumed that the association of the light-emitting compound can be suppressed by coexisting a surfactant, and the decrease in light emission efficiency and light emission intensity and concentration quenching can be suppressed.

  According to the present invention, it is possible to provide a light emitting material that has excellent durability, absorbs near ultraviolet rays (350 to 410 nm) and blue light (430 to 500 nm), emits light with high efficiency, and emits multicolor light. Become.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

  First, the light emitting material of the present invention will be described. The light emitting material of the present invention is characterized by containing a polymer of an organosilicon compound, a surfactant, and a light emitting compound.

  A polymer of an organosilicon compound according to the present invention (hereinafter referred to as “Si polymer”) is represented by the following formula (1):

It has a repeating unit represented by.

  In said formula (1), Ar represents 1 type independently selected from the group which consists of a phenylene group, a biphenylylene group, and a naphthylene group. In addition, each L is independently a divalent aliphatic organic group containing at least one selected from the group consisting of an ether group, a thioether group, a carbonyl group, a carbonate group, an amino group, an amide group, and a urethane group, an alkylene group Or represents a single bond.

  1-12 are preferable and, as for carbon number of the said alkylene group, 1-6 are more preferable. Of these alkylene groups, a methylene group, an ethylene group, a propylene group, a butylene group, a pentamethylene group, and a hexamethylene group are preferable, and an ethylene group, a propylene group, and a butylene group are more preferable. The divalent aliphatic organic group preferably further contains a divalent hydrocarbon group having 1 to 12 carbon atoms (more preferably 1 to 6 carbon atoms), and the divalent hydrocarbon group is alkylene. Groups are preferred.

  In addition, the Si polymer according to the present invention preferably has an absorption band at a wavelength of 350 to 410 nm or 430 to 500 nm. This makes it possible to use a high-efficiency light-emitting diode whose light-emitting region is in the near ultraviolet region or blue light region as a light source. Furthermore, since the Si polymer according to the present invention has a tetraphenylpyrene skeleton or a derivative skeleton thereof, it emits light having a wavelength of 400 to 650 nm.

  10-80 mass% is preferable with respect to 100 mass% of luminescent materials, and, as for the content rate of the said Si type polymer in the luminescent material of this invention, 30-70 mass% is more preferable. When the content of the Si-based polymer is less than the lower limit, the amount of light absorbed by the Si-based polymer tends to decrease or the emission intensity tends to decrease. On the other hand, when the upper limit is exceeded, the order of the mesostructure decreases. It tends to be easy to do.

  The Si polymer according to the present invention having a repeating unit represented by the formula (1) is represented by the following formula (2):

It is formed by polymerizing an organosilane precursor represented by the formula:

Ar and L in the formula (2) have the same meanings as Ar and L in the formula (1). R ¹ represents a methyl group or an ethyl group, and R ² represents an allyl group which may have a substituent such as a methyl group. Although n is an integer of 0 to 3, n is preferably an integer of 1 to 3 from the viewpoint that the condensation reaction easily proceeds and the structure after condensation is stable.

  Moreover, in this invention, what copolymerized the organic silane precursor represented by said Formula (2) and another organic silane compound can also be used as Si type polymer. Examples of the other organic silane compounds include dialkoxysilanes such as dimethoxysilane and diethoxysilane; trialkoxysilanes such as trimethoxysilane and triethoxysilane; and known alkoxysilane compounds such as tetraalkoxysilane such as tetramethoxysilane and tetraethoxysilane. Is mentioned.

  When (co) polymerizing the organosilane precursor and, if necessary, the other organosilane compound (hereinafter collectively referred to as “silane monomer”), the ratio of the organosilane precursor is (co) 10-100 mass% is preferable with respect to 100 mass% of all the silane monomers used for superposition | polymerization, and 50-100 mass% is more preferable. The conditions for the (co) polymerization reaction are not particularly limited, but water or a mixed solvent of water and an organic solvent is used as a solvent, and the silane monomer is hydrolyzed and condensed in the presence of an acid or base catalyst. Preferably. Suitable organic solvents used at this time include alcohol, acetone and the like, and the content of the organic solvent when used as a mixed solvent is preferably about 5 to 99% by weight. Examples of the acid catalyst include mineral acids such as hydrochloric acid, nitric acid, and sulfuric acid, and the solution in the case of using the acid catalyst is preferably acidic with a pH of 6 or less (more preferably 2 to 5). . Furthermore, examples of the base catalyst include sodium hydroxide, ammonium hydroxide, potassium hydroxide, and the like. When the base catalyst is used, the solution has a basic pH of 8 or more (more preferably 9 to 11). Preferably there is.

  The concentration of the silane monomer in such a (co) polymerization step is preferably about 0.0055 to 0.33 mol / L in terms of silicon concentration. Further, various conditions (temperature, time, etc.) in the polymerization step are not particularly limited, and are appropriately selected according to the silane monomer to be used, the target Si-based polymer, and the like. The silane monomer is preferably hydrolyzed and condensed at a temperature of about 1 to 48 hours.

  When the organic silane precursor is (co) polymerized, the silyl group in the formula (2) is usually hydrolyzed to form a silanol group (Si—OH), and a siloxane bond (Si— O-Si) is formed. At this time, even if a part of the silanol group is not converted into a siloxane bond and remains as it is, or an allyl group bonded to Si remains as it is, the light emission characteristics are not affected.

  In the present invention, the (co) polymerization reaction is preferably carried out in the presence of a surfactant. Thus, by performing the (co) polymerization reaction in the presence of a surfactant, a Si-based polymer (mesoporous material) having mesopores having a central pore diameter of 1 to 30 nm in the pore size distribution curve. Is obtained. The central pore diameter is a curve (pore diameter distribution curve) in which a value (dV / dD) obtained by differentiating the pore volume (V) with respect to the pore diameter (D) is plotted against the pore diameter (D). ) At the maximum peak, and can be determined by the method described below. That is, the mesoporous material is cooled to a liquid nitrogen temperature (−196 ° C.), nitrogen gas is introduced, the adsorption amount is determined by a constant volume method or a gravimetric method, and then the pressure of the introduced nitrogen gas is gradually increased. Then, the adsorption amount of nitrogen gas with respect to each equilibrium pressure is plotted to obtain an adsorption isotherm. Using this adsorption isotherm, a pore size distribution curve can be obtained by a calculation method such as Cranston-Inklay method, Pollimore-Heal method, or BJH method.

Such a mesoporous material preferably contains 60% or more of the total pore volume in a range of ± 40% of the center pore diameter in the pore diameter distribution curve. A mesoporous material satisfying this condition means that the pore diameter is very uniform. The specific surface area of the mesoporous material is not particularly limited, but is preferably 700 m ² / g or more. The specific surface area can be calculated as a BET specific surface area from the adsorption isotherm using the BET isotherm adsorption equation.

  Further, such a mesoporous material preferably has one or more peaks at a diffraction angle corresponding to a d value of 1.5 to 30.5 nm in its X-ray diffraction (XRD) pattern. The X-ray diffraction peak means that a periodic structure having a d value corresponding to the peak angle is present in the sample. Therefore, having one or more peaks at a diffraction angle corresponding to a d value of 1.5 to 30.5 nm indicates that the pores are regularly arranged at intervals of 1.5 to 30.5 nm. means.

  The surfactant used in obtaining the Si-based polymer having mesopores according to the present invention is not particularly limited, and may be any of cationic, anionic and nonionic. Specifically, chlorides, bromides, iodides or hydroxides such as alkyltrimethylammonium, alkyltriethylammonium, dialkyldimethylammonium, benzylammonium; fatty acid salts, alkylsulfonates, alkylphosphates, polyethylene oxide non-ions Surfactants and primary alkylamines. These surfactants may be used alone or in combination of two or more.

Among the above surfactants, examples of the polyethylene oxide nonionic surfactant include a polyethylene oxide nonionic surfactant having a hydrocarbon group as a hydrophobic component and polyethylene oxide as a hydrophilic portion. . Such surfactants, for example, the general formula _{C n H 2n + 1 (OCH} 2 CH 2) expressed in m OH, n is 10 to 30, m can be preferably used those which are 1 to 30. As such a surfactant, an ester of a fatty acid such as oleic acid, lauric acid, stearic acid, and palmitic acid and sorbitan, or a compound obtained by adding polyethylene oxide to these esters can also be used.

Further, as such a surfactant, a triblock copolymer type polyalkylene oxide may be used. Examples of such surfactants include those composed of polyethylene oxide (EO) and polypropylene oxide (PO) and represented by the general formula (EO) _x (PO) _y (EO) _x . x and y represent the number of repetitions of EO and PO, respectively, x is preferably 5 to 110, y is preferably 15 to 70, x is preferably 13 to 106, and y is more preferably 29 to 70. Examples of the triblock copolymer include (EO) ₁₉ (PO) ₂₉ (EO) ₁₉ , (EO) ₁₃ (PO) ₇₀ (EO) ₁₃ , (EO) ₅ (PO) ₇₀ (EO) ₅ , (EO). ₁₃ (PO) ₃₀ (EO) ₁₃ , (EO) ₂₀ (PO) ₃₀ (EO) ₂₀ , (EO) ₂₆ (PO) ₃₉ (EO) ₂₆ , (EO) ₁₇ (PO) ₅₆ (EO) ₁₇ , ( EO) ₁₇ (PO) ₅₈ (EO) ₁₇ , (EO) ₂₀ (PO) ₇₀ (EO) ₂₀ , (EO) ₈₀ (PO) ₃₀ (EO) ₈₀ , (EO) ₁₀₆ (PO) ₇₀ (EO) ₁₀₆ , (EO) ₁₀₀ (PO) ₃₉ (EO) ₁₀₀ , (EO) ₁₉ (PO) ₃₃ (EO) ₁₉ , (EO) ₂₆ (PO) ₃₆ (EO) ₂₆ . These triblock copolymers are available from BASF, Aldrich, etc., and triblock copolymers having desired x and y values can be obtained at a small scale production level.

Also, a star diblock copolymer in which two polyethylene oxide (EO) chains-polypropylene oxide (PO) chains are bonded to two nitrogen atoms of ethylenediamine can be used. Examples of such star diblock copolymers include those represented by the general formula ((EO) _x (PO) _y ) ₂ NCH ₂ CH ₂ N ((PO) _y (EO) _x ) ₂ . Here, x and y represent the number of repetitions of EO and PO, respectively, x is preferably 5 to 110, y is preferably 15 to 70, x is 13 to 106, and y is 29 to 70. preferable.

Among such surfactants, since a mesoporous material having high pore ordering can be obtained, a salt (preferably a halide salt) of alkyltrimethylammonium [C _p H _{2p + 1} N (CH ₃ ) ₃ ]. ) Is preferably used. In that case, the alkyl group in the alkyltrimethylammonium preferably has 8 to 22 carbon atoms. Examples include octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, decyltrimethylammonium bromide, octyltrimethylammonium bromide, and docosyltrimethylammonium chloride. It is done.

  In the case of producing the Si-based polymer according to the present invention using the surfactant as described above, the organosilane precursor represented by the formula (2) is hydrolyzed in the solvent containing the surfactant. A porous precursor obtained by introducing the surfactant into the Si-based polymer is obtained by decomposing and condensing. The concentration of the surfactant in the solution is preferably 1 to 20% by mass. When the concentration of the surfactant is less than the lower limit, pore formation tends to be incomplete. On the other hand, when the concentration exceeds the upper limit, the amount of the unreacted surfactant remaining in the solution increases and becomes finer. There is a tendency that the uniformity of the holes tends to decrease.

  The luminescent material of the present invention contains a surfactant in addition to the Si-based polymer having the repeating unit represented by the formula (1). By this surfactant, association of the luminescent compound can be suppressed, and it becomes possible to suppress a decrease in luminous efficiency and luminescence intensity and concentration quenching. Examples of such surfactants include those exemplified for the Si-based polymer.

  In the light emitting material of the present invention, the surfactant may be added to the Si polymer, but when a surfactant is used during the (co) polymerization, it is not removed, It is preferable to leave it in the luminescent material as it is.

  20-90 mass% is preferable with respect to 100 mass% of luminescent materials, and, as for the content rate of the said surfactant in the luminescent material of this invention, 30-70 mass% is more preferable. When the content of the surfactant is less than the lower limit, the association of the luminescent compounds tends not to be sufficiently suppressed. On the other hand, when the content exceeds the upper limit, the light absorption rate and the emission intensity tend to decrease.

  Moreover, the luminescent material of the present invention contains a luminescent compound in addition to the Si polymer and the surfactant. In addition, this luminescent compound is different from the Si-based polymer, and in particular, a light-emitting wavelength region is preferably different from the Si-based polymer. This enables multicolor light emission.

The luminescent compound according to the present invention is not particularly limited, and examples thereof include organic dyes, metal complexes, and inorganic nanoparticles. Examples of the organic dye include porphyrins, anthracenes, fluorescein, rhodamine (B, 6G, etc.), coumarin, pyrene, dansylic acid, cyanine dye, merocyanine dye, styryl dye, and benzstyryl dye. Examples of the metal complex include an aluminum complex, a rare earth element, and a complex thereof. Examples of the inorganic nanoparticles include semiconductor nanoparticles typified by CdS, and oxide nanoparticles such as YAG: Ce and Y ₂ O ₂ S: Eu. These luminescent compounds may be used alone or in combination of two or more.

  Moreover, you may use a phosphorescent compound as a luminescent compound concerning this invention. Some of these phosphorescent compounds have a large difference between absorption and emission wavelengths compared to fluorescent compounds. Therefore, by using such a phosphorescent compound, it becomes possible to efficiently emit long-wavelength light by absorbing short-wavelength light. By combining such a phosphorescent compound with, for example, the Si-based polymer according to the present invention having an absorption band in the near-ultraviolet region or blue light region, the near-ultraviolet light or blue light emitted from the high-efficiency light-emitting diode can be efficiently absorbed. It is possible to achieve high luminous efficiency. Although it does not specifically limit as said phosphorescent compound, The thing of the following structural formulas which can light-emit comparatively efficiently at room temperature is mentioned as a suitable thing.

  0.01-10 mass% is preferable with respect to 100 mass% of luminescent materials, and, as for the content rate of the said luminescent compound in the luminescent material of this invention, 0.1-5 mass% is more preferable. If the content of the luminescent compound is less than the above lower limit, light emission by the luminescent compound tends to be insufficient, and sufficient multicolor emission tends not to occur. On the other hand, if the content exceeds the upper limit, the dispersion of the luminescent compound becomes insufficient and quenching occurs. It tends to be easy. Moreover, it becomes possible to easily adjust the luminescent color of the luminescent material by adjusting the content of the luminescent compound.

  The luminescent material of the present invention contains a polymerization inhibitor and / or an antioxidant as necessary in addition to the Si polymer, the surfactant and the luminescent compound. A conventionally well-known thing can be used as said polymerization inhibitor and antioxidant, For example, a phenol type compound is preferable and hydroquinone and its derivative (s) are preferable. By adding such a polymerization inhibitor and / or antioxidant, the stability of the luminescent material, for example, the durability of the luminescent material against light irradiation (particularly ultraviolet irradiation) is improved.

  0.01-30 mass% is preferable with respect to 100 mass% of light emitting materials, and, as for the content rate of the said polymerization inhibitor and antioxidant in the light emitting material of this invention, 0.2-20 mass% is more preferable. If the content of the polymerization inhibitor and the antioxidant is less than the lower limit, the stability of the light emitting material tends not to be sufficiently improved. On the other hand, if the content exceeds the upper limit, the luminous efficiency tends to decrease.

  In the luminescent material of the present invention, the form of the Si polymer is not particularly limited, and examples thereof include particles, thin films, and patterns obtained by patterning the thin film into a predetermined shape. In the luminescent material of the present invention, the Si polymer may be supported on mesoporous silica such as FSM.

  When manufacturing the luminescent material of this invention, after mixing the said silane monomer, the said surfactant, and the said luminescent compound, you may superpose | polymerize the said silane monomer. This makes it possible to fill the pores of the polymer of the silane monomer with the surfactant and the light emitting compound, and to efficiently emit light from the light emitting material. Moreover, after mixing the said silane monomer and the said surfactant and polymerizing the said silane monomer, you may add the said luminescent compound to this solution. At this time, it is preferable that the luminescent compound is dissolved in an appropriate solvent and added to the solution. Thereby, the luminescent compound can be uniformly mixed in the solution, and the luminescent material can emit light efficiently.

  For example, in order to obtain a thin-film luminescent material, first, the silane monomer is added to an acidic solution (hydrochloric acid, nitric acid aqueous solution or alcohol solution) containing the surfactant, and the solution is stirred to react. (Partial hydrolysis and partial condensation reaction) A sol solution containing the partial polymer is prepared. Since such hydrolysis reaction of the silane monomer is likely to occur in a low pH region, partial polymerization can be promoted by lowering the pH of the system. At this time, the pH is preferably 2 or less, and more preferably 1.5 or less. Further, the reaction temperature at that time is preferably about 15 to 25 ° C., and the reaction time is preferably about 30 minutes to 1 day.

  Next, the luminescent compound is added to the sol solution thus obtained, and this is applied to a substrate to produce a thin-film luminescent material. The method for applying the sol solution to the substrate is not particularly limited, and various coating methods can be appropriately employed. Examples of the method include a solution casting method, a coating method using a bar coater, a roll coater, a gravure coater, and the like, a method such as dip coating, spin coating, and spray coating. Furthermore, it is also possible to form a patterned light emitting material on a substrate by applying a sol solution by an ink jet method.

  Next, the obtained thin film is preferably dried at about 25 to 120 ° C., and the polycondensation reaction of the partial polymer is advanced to form a three-dimensional crosslinked structure. The average film thickness of the obtained thin film is preferably 2 μm or less, and more preferably 0.1 to 0.5 μm.

  Such a thin-film luminescent material can be obtained in accordance with a method described in JP-A-2001-130911.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. The ultraviolet / visible absorption spectrum and emission spectrum of the obtained thin film were measured using “FP-6600 Spectrofluorometer” manufactured by JASCO.

(Synthesis Example 1)
<Synthesis of 1,3,6,8-tetrakis [4- (3-triethoxysilylpropylaminocarbonyloxy) phenyl] pyrene>
First, under an argon atmosphere, 1,3,6,8-tetrabromopyrene (4.14 g, 8.0 mmol), 4-methoxyphenylboronic acid (7.29 g, 48.0 mmol), K ₂ CO ₃ (8 .85 g, 64.0 mmol) and Pd (PPh ₃ ) ₄ (0.148 g, 0.128 mmol) were mixed and dehydrated 1,4-dioxane (80 ml) was added to the mixture. The mixture was stirred at 85 ° C. for 70 hours under an argon atmosphere and the following reaction formula (3):

The reaction represented by Then, after cooling to room temperature, the reaction product was poured into a mixture of concentrated hydrochloric acid and ice (volume ratio 1: 3) and stirred for 0.5 hour. Thereafter, the organic phase was extracted with chloroform, dried over anhydrous MgSO ₄ . MgSO ₄ was removed from the organic phase by filtration, and the solvent was distilled off with a rotary evaporator. The residue was recrystallized from toluene to obtain 1,3,6,8-tetrakis (4-methoxyphenyl) pyrene (4.65 g, yield 93%) as yellow crystals.

This 1,3,6,8-tetrakis (4-methoxyphenyl) pyrene was identified by ¹ H-NMR measurement. The results are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.16 (s, 4H), 7.96 (s, 2H), 7.59 (d, J = 8.7 Hz, 8H), 7.07 (d, J = 8.7 Hz, 8H), 3.91 (s, 12H).

Next, 1,3,6,8-tetrakis (4-methoxyphenyl) pyrene (4.00 g, 6.38 mmol) was dissolved in distilled dichloromethane (300 ml), and then cooled to 0 ° C. A 1 mol / L BBr ₃ dichloromethane solution (32 ml) was gradually added dropwise to this solution, followed by stirring at 0 ° C. for 0.5 hour and then at room temperature for 15 hours.

The reaction represented by Subsequently, after heating and refluxing for 2 hours, the reaction product was cooled to room temperature, and water (200 ml) was added to stop the reaction. The resulting precipitate was collected by suction filtration, dissolved in ethanol, and reprecipitated by adding water. Thereafter, the precipitate was collected by suction filtration and vacuum-dried to obtain 1,3,6,8-tetrakis (4-hydroxyphenyl) pyrene (3.40 g, yield 93%) as a yellow-green solid.

This 1,3,6,8-tetrakis (4-hydroxyphenyl) pyrene was identified by ¹ H-NMR measurement. The results are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 9.68 (s, 4H), 8.11 (s, 4H), 7.84 (s, 2H), 7.48 (d, J = 8.5 Hz, 8H), 6.97 (d, J = 8.5 Hz, 8H).

  Next, 1,3,6,8-tetrakis (4-hydroxyphenyl) pyrene (0.80 g, 1.40 mmol), distilled dichloromethane (80 ml) and triethylamine (10 ml) were mixed, and this mixture was mixed with 3-triethoxy. Silylpropyl isocyanate (1.98 g, 8.00 mmol) was added, and the mixture was stirred at room temperature for 24 hours, then heated to reflux for 2 hours, and the following reaction formula (5):

The reaction represented by After the solvent was distilled off from the obtained solution with a rotary evaporator, toluene was added and stirred, and insolubles were removed by filtration. The operation of adding hexane to the obtained toluene solution and reprecipitation was repeated twice, and then the precipitate was collected by suction filtration, dried in vacuo and dried as a light yellow solid 1,3,6,8-tetrakis [4- ( 3-Triethoxysilylpropylaminocarbonyloxy) phenyl] pyrene (1.62 g, yield 74%) was obtained.

This 1,3,6,8-tetrakis [4- (3-triethoxysilylpropylaminocarbonyloxy) phenyl] pyrene was identified by ¹ H-NMR measurement, ¹³ C-NMR measurement, IR measurement and MS measurement. The results are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.16 (s, 4H), 7.97 (s, 2H), 7.63 (d, J = 8.3 Hz, 8H), 7.31 (d, J = 8.3 Hz, 8H), 5.59 (t, J = 5.9 Hz, 4H), 3.87 (q, J = 7.0 Hz, 24H), 3.33 (m, 8H), 1. 76 (m, 8H), 1.27 (t, J = 7.0 Hz, 36H), 0.73 (t, J = 8.0 Hz, 8H).
¹³ C-NMR (100 MHz, CDCl ₃ ): δ 154.5, 150.5, 137.7, 136.4, 131.3, 129.6, 128.0, 125.8, 125.2, 121.4 , 58.4, 43.5, 23.0, 18.2, 7.6
IR (ATR, cm ⁻¹ ): 3329 (NH st), 3039, 2974, 2928, 2885, 1716 (C═O st), 1533, 1489, 1203, 1165, 1070.
MS (MALDI, m / z): calcd for 15588.6790 [M] ⁺ , found 15588.6809.

(Synthesis Example 2)
After synthesizing 1,3,6,8-tetrakis (4-hydroxyphenyl) pyrene in the same manner as in Synthesis Example 1, this 1,3,6,8-tetrakis (4-hydroxyphenyl) pyrene (0.6 g, 1.05 mmol), distilled dimethylformamide (20 ml) and potassium carbonate (2.49 g, 18.0 mmol) were added, and allyl bromide (1.45 g, 12.0 mmol) was added to the mixture and stirred at room temperature for 20 hours. The following reaction formula (6):

The reaction represented by Water (100 ml) was added to the resulting reaction solution, and the deposited precipitate was collected by suction filtration and then washed with water and ethanol. The filter cake was heated and stirred in ethanol, then subjected to suction filtration, vacuum dried, and 1,3,6,8-tetrakis [4- (allyloxy) phenyl] pyrene (0.67 g, yield) as a pale yellow solid. 87%).

This 1,3,6,8-tetrakis [4- (allyloxy) phenyl] pyrene was identified by ¹ H-NMR measurement. The results are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.15 (s, 4H), 7.95 (s, 2H), 7.58 (d, J = 8.7 Hz, 8H), 7.08 (d, J = 8.7 Hz, 8H), 6.13 (ddt, J = 17.4, 10.4, 5.4 Hz, 4H), 5.49 (dd, J = 17.4, 3.0 Hz, 4H) 5.34 (dd, J = 10.4, 3.0 Hz, 4H), 4.65 (d, J = 5.4 Hz, 8H).

  Next, 1,3,6,8-tetrakis [4- (allyloxy) phenyl] pyrene (0.6 g, 0.82 mmol), distilled tetrahydrofuran (20 ml) and triethoxysilane (0.82 g, 5.00 mmol) were added. Then, a platinum catalyst (platinum (0) -1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex in 3% by mass xylene, 50 mg) was added to the mixture, Stir for the following reaction formula (7):

The reaction represented by The resulting solution was cooled to room temperature and filtered through celite and activated carbon, and then the solvent was removed with a rotary evaporator, followed by vacuum drying to obtain 1,3,6,8-tetrakis [4- (3-tri Ethoxysilylpropyloxy) phenyl] pyrene (1.07 g, 94% yield) was obtained.

This 1,3,6,8-tetrakis [4- (3-triethoxysilylpropyloxy) phenyl] pyrene was identified by ¹ H-NMR measurement. The results are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.16 (s, 4H), 7.96 (s, 2H), 7.57 (d, J = 8.4 Hz, 8H), 7.07 (d, J = 8.4 Hz, 8H), 4.06 (t, J = 6.5 Hz, 8H), 3.88 (q, J = 7.0 Hz, 24H), 2.0 (m, 8H), 1. 76 (m, 8H), 1.27 (t, J = 7.0 Hz, 36H), 0.85 (m, 8H).

(Reference Example 1)
<Preparation of thin film made of tetraphenylpyrene skeleton-containing Si-based polymer / surfactant>
1,3,6,8-tetrakis [4- (3-triethoxysilylpropylaminocarbonyloxy) phenyl obtained in Synthesis Example 1 was added to a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1, 1.0 g). Pyrene (15 mg), tetraethoxysilane (15 mg), nonionic surfactant P123 (trade name, manufactured by Aldrich, chemical formula: HO (CH ₂ CH ₂ O) ₂₀ (CH ₂ CH (CH ₃ ) O) ₇₀ ( CH ₂ CH ₂ O) ₂₀ H, 20 mg), 2 mol / L hydrochloric acid (4 μl) and pure water (20 μl) were added and mixed, and the mixture was stirred at room temperature for 24 hours to prepare a sol solution.

  The obtained sol solution was applied onto a quartz substrate and a glass substrate by a spin casting method (rotation speed: 4000 rpm, 30 seconds) or a solution casting method, respectively, from a tetraphenylpyrene skeleton-containing Si polymer / surfactant. A thin film was obtained.

  The ultraviolet / visible absorption spectrum (dotted line) and emission spectrum (solid line) of this thin film are shown in FIG. 1, and the X-ray diffraction pattern is shown in FIG. The obtained thin film had absorption in the near-ultraviolet to visible light region centered around 390 nm and exhibited blue light emission around 450 nm. The fluorescence quantum yield when excited with light of 400 nm was 0.75. Further, as apparent from the results shown in FIG. 2, it was confirmed that this thin film had a mesostructure with a period of about 8.5 nm.

Example 1
<Preparation of a thin film comprising tetraphenylpyrene skeleton-containing Si polymer / surfactant / fluorescent dye>
1,3,6,8-tetrakis [4- (3-triethoxysilylpropylaminocarbonyloxy) phenyl] pyrene obtained in Synthesis Example 1 was added to a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1, 10 ml). (300 mg), tetraethoxysilane (300 mg), nonionic surfactant P123 (400 mg), 2 mol / L hydrochloric acid (80 μl) and pure water (400 μl) were added and mixed, and a mixed solvent of tetrahydrofuran and ethanol ( The mixture was prepared so that the total amount became 20 ml by adding mass ratio 1: 1). Next, this mixture was stirred at room temperature for 24 hours to prepare a sol solution (tetraphenylpyrene skeleton concentration: 9.6 mmol / L).

  In the obtained sol solution, the following formula (8):

In an ethanol solution (concentration: 9.6 mmol / L) of the fluorescent dye rhodamine 6G represented by the formula, rhodamine 6G is 0.2, 0.5, 1 or 2 mol with respect to 100 mol of the tetraphenylpyrene skeleton. Added. The sol solution containing the fluorescent dye was applied onto a quartz substrate by a spin cast method (rotation speed: 4000 rpm, 30 seconds) to obtain a thin film composed of a tetraphenylpyrene skeleton-containing Si polymer / surfactant / fluorescent dye. . FIG. 3 shows the emission spectrum of the thin film with respect to 400 nm excitation light, FIG. 4 shows the chromaticity diagram of the emission color, and Table 1 shows the chromaticity coordinates.

  As is apparent from the results shown in FIG. 3, in the thin film, in addition to light emission from the tetraphenylpyrene skeleton near 450 nm, light emission from rhodamine 6G by excitation energy transfer from the tetraphenylpyrene skeleton to rhodamine 6G ( Around 560 nm) was observed.

  Further, as apparent from the results shown in FIG. 4 and Table 1, the thin film emitted blue to white light depending on the amount of rhodamine 6G added. The quantum yield at the time of 400 nm excitation of the thin film in which the addition amount of rhodamine 6G was 0.2 mol was 0.68.

(Example 2)
<Preparation of a thin film comprising tetraphenylpyrene skeleton-containing Si polymer / surfactant / fluorescent dye / hydroquinone>
To the sol solution containing rhodamine 6G prepared in Example 1, a tetrahydrofuran solution (concentration: 9.6 mmol / L) of hydroquinone was further added so that the hydroquinone was equimolar with respect to the tetraphenylpyrene skeleton. A tetraphenylpyrene skeleton-containing Si-based polymer in the same manner as in Example 1 except that a sol solution containing a surfactant, a fluorescent dye, and hydroquinone was used instead of the sol solution containing the surfactant and the fluorescent dye. A thin film made of surfactant / fluorescent dye / hydroquinone was prepared. FIG. 5 shows an emission spectrum of the thin film with respect to 400 nm excitation light, FIG. 6 shows a chromaticity diagram of emission colors, and Table 2 shows chromaticity coordinates.

  As is apparent from the results shown in FIG. 5, in the thin film, in addition to light emission from the tetraphenylpyrene skeleton near 450 nm, light emission from rhodamine 6G by excitation energy transfer from the tetraphenylpyrene skeleton to rhodamine 6G ( Around 560 nm) was observed.

  Further, as apparent from the results shown in FIG. 6 and Table 2, the thin film emitted blue to white light depending on the amount of rhodamine 6G added. The quantum yield at the time of 400 nm excitation of the thin film in which the addition amount of rhodamine 6G was 0.2 mol was 0.61.

(Comparative Example 1)
<Preparation of thin film composed of tetraphenylpyrene skeleton-containing Si polymer / fluorescent dye>
1,3,6,8-tetrakis [4- (3-triethoxysilylpropylaminocarbonyloxy) phenyl] pyrene obtained in Synthesis Example 1 was added to a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1, 1 ml). (30 mg), tetraethoxysilane (30 mg), 2 mol / L hydrochloric acid (4 μl) and pure water (20 μl) were added and mixed, and a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1) was further added. The mixture was prepared so that the total amount was 2 ml. Next, this mixture was stirred at room temperature for 24 hours to prepare a sol solution containing no surfactant (tetraphenylpyrene skeleton concentration: 9.6 mmol / L).

  An ethanol solution of rhodamine 6G (concentration: 9.6 mmol / L) was added to the obtained sol solution so that rhodamine 6G was 0.2 mol or 1 mol with respect to 100 mol of tetraphenylpyrene skeleton. A thin film comprising a tetraphenylpyrene skeleton-containing Si polymer / fluorescent dye (surfactant) in the same manner as in Example 1 except that this sol solution containing no surfactant was used instead of the sol solution containing the surfactant. None). This thin film absorbed fluorescence at 400 nm and emitted fluorescence. FIG. 7 shows an emission spectrum of a thin film having an addition amount of rhodamine 6G of 0.2 mol when excited at 400 nm.

  As is apparent from the results shown in FIG. 7, in the thin film, in addition to light emission from the tetraphenylpyrene skeleton near 450 nm, light emission from rhodamine 6G by excitation energy transfer from the tetraphenylpyrene skeleton to rhodamine 6G ( Around 560 nm) was observed. When the addition amount of rhodamine 6G is 0.2 mol, the quantum yield at the time of 400 nm excitation of the thin film not containing the surfactant is 0.23, and when the surfactant is added (Example 1) Compared to a large drop.

(Comparative Example 2)
<Manufacture of anthracene skeleton-containing Si-based polymer / thin film made of fluorescent dye>
In a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1, 1 ml), the following formula (9):

9,10-bis (triethoxysilyl) anthracene represented by the formula (9.7 mg), tetraethoxysilane (9.7 mg), 2 mol / L hydrochloric acid hydrochloric acid (8 μl) and pure water (40 μl) were added and mixed. Further, a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1) was added to prepare a mixture so that the total amount was 2 ml. Next, this mixture was stirred at room temperature for 24 hours to prepare a sol solution containing no surfactant (concentration of anthracene skeleton: 9.6 mmol / L).

  An ethanol solution of rhodamine 6G (concentration: 9.6 mmol / L) was added to the obtained sol solution so that rhodamine 6G was 0.2 mol or 1 mol with respect to 100 mol of anthracene skeleton. Comparative Example 1 was used except that this sol solution of an anthracene skeleton-containing Si polymer (no surfactant) was used instead of the tetraphenylpyrene skeleton-containing Si polymer sol solution (no surfactant). A thin film (no surfactant) made of an anthracene skeleton-containing Si-based polymer / fluorescent dye was prepared. This thin film absorbed fluorescence at 400 nm and emitted fluorescence. FIG. 8 shows an emission spectrum at 400 nm excitation of a thin film having an addition amount of rhodamine 6G of 0.2 mol.

  As is clear from the results shown in FIG. 8, in the thin film, light emission from the anthracene skeleton is only slightly observed at around 500 nm, and from the rhodamine 6G due to excitation energy transfer from the anthracene skeleton to rhodamine 6G. Luminescence (near 560 nm) was observed. When the amount of rhodamine 6G added is 0.2 mol, the quantum yield of the thin film having an anthracene skeleton at 400 nm excitation is 0.04, and in the case of the thin film having a tetraphenylpyrene skeleton (Comparative Example 1). Compared to a large drop.

(Comparative Example 3)
<Preparation of a thin film comprising an anthracene skeleton-containing Si-based polymer / surfactant / fluorescent dye>
9,10-bis (triethoxysilyl) anthracene (9.7 mg), tetraethoxysilane (9.7 mg), nonionic surfactant P123 in a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1, 1 ml). (20 mg), 2 mol / L hydrochloric acid (8 μl) and pure water (40 μl) are added and mixed, and a mixed solvent of tetrahydrofuran and ethanol (mass ratio 1: 1) is further added so that the total amount becomes 2 ml. A mixture was prepared. Next, this mixture was stirred at room temperature for 24 hours to prepare a sol solution (concentration of anthracene skeleton: 9.6 mmol / L).

  An ethanol solution of rhodamine 6G (concentration: 9.6 mmol / L) was added to the obtained sol solution so that rhodamine 6G was 0.2 mol or 1 mol with respect to 100 mol of anthracene skeleton. Example 1 was used except that this sol solution of an anthracene skeleton-containing Si polymer (with a surfactant) was used instead of the tetraphenylpyrene skeleton-containing Si polymer sol solution (with a surfactant). A thin film comprising an anthracene skeleton-containing Si polymer / surfactant / fluorescent dye was prepared. This thin film absorbed fluorescence at 400 nm and emitted fluorescence. FIG. 9 shows an emission spectrum at 400 nm excitation of a thin film having an addition amount of rhodamine 6G of 0.2 mol.

  As is clear from the results shown in FIG. 9, in the thin film, light emission from the anthracene skeleton is only slightly observed at around 500 nm, and from the rhodamine 6G due to excitation energy transfer from the anthracene skeleton to rhodamine 6G. Luminescence (near 560 nm) was observed. When the amount of rhodamine 6G added is 0.2 mol, the quantum yield of the thin film having an anthracene skeleton at 400 nm excitation is 0.25, and in the case of the thin film having a tetraphenylpyrene skeleton (Example 1). Compared to a large drop.

<Durability test>
Of the Si polymer thin films prepared in Examples 1-2 and Comparative Examples 2-3, a Si polymer thin film in which the addition amount of rhodamine 6G is 1 mol per 100 mol of tetraphenylpyrene skeleton or 100 mol of anthracene skeleton. On the other hand, light of 400 nm was irradiated in the atmosphere at 3 J / cm ² (0.05 mW / cm ² , 16.7 hours). The absorption intensity at 400 nm after light irradiation was determined as a relative value with respect to the absorption intensity before light irradiation (the absorption intensity before light irradiation is 100). The result is shown in FIG.

  As is clear from the results shown in FIG. 10, in the case of the Si polymer thin film of the present invention containing no hydroquinone (Example 1), the decrease in absorption intensity due to light irradiation was about 4%. When hydroquinone was contained (Example 2), it was less than 2%. On the other hand, in the Si-based polymer thin film (without hydroquinone) having an anthracene skeleton, the decrease in absorption intensity due to light irradiation includes 30% or more of the surfactant when the surfactant is not included (Comparative Example 2). In the case (Comparative Example 3), it was 60% or more.

  As described above, according to the present invention, it is possible to cause a light emitting material to absorb near ultraviolet rays and blue light to emit light with high efficiency and to emit multicolor light.

  Therefore, since the light emitting material of the present invention is excellent in durability, it is useful for light emitting elements such as light emitting diodes, and is particularly useful for light emitting diodes that require multicolor light emission.

2 is a graph showing an ultraviolet / visible absorption spectrum and an emission spectrum of the Si polymer thin film obtained in Reference Example 1. FIG. 4 is a graph showing an X-ray diffraction pattern of the Si-based polymer thin film obtained in Reference Example 1. 4 is a graph showing an emission spectrum of the Si polymer thin film obtained in Example 1 with respect to 400 nm excitation light. 3 is a graph showing the chromaticity of light emission of the Si-based polymer thin film obtained in Example 1. 4 is a graph showing an emission spectrum of the Si polymer thin film obtained in Example 2 with respect to 400 nm excitation light. 4 is a graph showing the chromaticity of light emission of the Si polymer thin film obtained in Example 2. FIG. It is a graph which shows the emission spectrum with respect to the excitation light of 400 nm of the Si type polymer thin film whose addition amount of the fluorescent pigment | dye obtained in the comparative example 1 is 0.2 mol. It is a graph which shows the emission spectrum with respect to the excitation light of 400 nm of the Si type polymer thin film whose addition amount of the fluorescent pigment | dye obtained in the comparative example 2 is 0.2 mol. It is a graph which shows the emission spectrum with respect to the excitation light of 400 nm of the Si type polymer thin film whose addition amount of the fluorescent pigment | dye obtained in the comparative example 3 is 0.2 mol. It is a graph which shows the absorption intensity before and behind light irradiation of the Si type polymer thin film whose addition amount of the fluorescent pigment | dye obtained in Examples 1-2 and Comparative Examples 2-3 was 1 mol.

Claims (4)

Following formula (1):

(In the formula (1), each Ar independently represents one selected from the group consisting of a phenylene group, a biphenylylene group and a naphthylene group, and each L independently represents an ether group, a thioether group, a carbonyl group, a carbonate group, It represents a divalent aliphatic organic group, an alkylene group or a single bond containing at least one group selected from the group consisting of an amino group, an amide group and a urethane group.)
A light-emitting material comprising a polymer of an organosilicon compound having a repeating unit represented by formula (II), a surfactant, and a light-emitting compound.   The light-emitting material according to claim 1, wherein the polymer of the organosilicon compound has a mesostructure.   The light emitting material according to claim 1 or 2, wherein the polymer of the organosilicon compound has an absorption band at a wavelength of 350 to 410 nm or 430 to 500 nm.   Furthermore, at least 1 sort (s) selected from the group which consists of a polymerization inhibitor and antioxidant is contained, The luminescent material as described in any one of Claims 1-3 characterized by the above-mentioned.

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