JP2650753B2 - Alkali metal compound of carbon nitride and method for producing the same - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an alkali metal compound of carbon nitride having a novel chemical composition and a method for producing the same, and more particularly to an optical material, particularly a fluorescent material, and a semiconductive material. The present invention relates to a method for producing an alkali metal compound of carbon nitride useful as a functional material, a lubricating material, an ion exchanger, and an ion conductor.

[Prior art and problems to be solved] Conventionally, various compounds of nitrogen, such as silicon nitride and boron nitride, are known. For example, silicon nitride is formed by reacting silicon tetrachloride with ammonia. After the imide is produced, it can be obtained by pyrolyzing it, but carbon cannot be nitrided with nitrogen or ammonia, and no inorganic polymeric compound consisting solely of carbon, nitrogen and hydrogen has been known. .

Thus, the present inventors have conducted various studies under various conditions, and as a result, have found that carbon nitride synthesized by using a compound containing a triazine ring of carbon and nitrogen such as cyanuric chloride and melamine as a reaction raw material, and a method for producing the same. And has already filed an application [(Japanese Patent Application No. 63-173186) "Carbon nitride and its production method"].

Carbon nitride has the property of emitting fluorescence, and is desired as a phosphor for a high-pressure mercury lamp. However, in order to use it as a single-color light-emitting element, it is desirable to narrow the emission wavelength width and increase the intensity. I was

[Means for Solving the Problems] The present inventors have made various studies in order to solve the above-mentioned problems in the present situation, and as a result, reacted carbon nitride with an MOH aqueous solution (where M = K, Na, Li). As a result, a polymer containing an alkali metal can be synthesized, and it has been found that the compound narrows the emission wavelength width and increases the intensity, and has reached the present invention.

That is, the present invention has the general formula _{C 6 N α H β O γ} M δ ( However, M = K, Na, Li , 5.0 ≦ α ≦ 10.0,0 <β, γ ≦ 14.0,0
An alkali metal compound of carbon nitride having a layered structure represented by <δ ≦ 5.0) and carbon nitride [(C ₃ N ₃ ) ₂ N
_x H _y] (where, 2 ≦ x ≦ 4,0 ≦ y ≦ 8) and MOH solution (where, M = K, Na, Li ) preparation of said compounds, characterized by reacting, even the It is a fluorescent material composed of a compound.

The carbon nitride used as the raw material is the same as previously filed Japanese Patent Application No. 63-173186.
It is obtained by reacting cyanuric chloride with ammonia or cyanuric chloride and melamine, followed by thermal decomposition. The compound has the general formula [(C ₃ N ₃ ) ₂ N _x H
_y ] (where 2 ≦ x ≦ 4,0 ≦ y ≦ 8), a layered polymer synthesized from cyanuric chloride-ammonia type, melamine type only, or melamine-cyanuric chloride type as a raw material of the present invention. preferable. Note that, regarding carbon nitride, although the method of expressing the general formula is different from that in the earlier application, the ratio of the constituent atoms in the compound is exactly the same, indicating the same compound.

Next, the reaction of an aqueous solution of MOH (however, M = K, Na, Li) and carbon nitride is described. The aqueous solution of MOH (however, M = K, Na, Li) used for the reaction is an aqueous solution of KOH, NaOH, LiOH. It is suitable, preferably an aqueous KOH solution. The concentration is preferably 0.1 to 10N. At 0.1 N or less, alkali metal is hardly introduced, and 10
It is difficult to prepare an aqueous solution of N or more. However, LiOH aqueous solution
It can only be made up to a concentration of 1.25N.

The amount used is 100cc of MOH aqueous solution (M = K, Na, Li)
On the other hand, the amount of the polymer is preferably 0.1 to 3 g. If 3 g or more of the polymer is added, uniform mixing is difficult.

The reaction temperature is preferably around room temperature, and the mixture is stirred and reacted for 0.5 to 24 hours. After the completion of the reaction, the product is filtered and further washed until alkalinity disappears.

The compound obtained by the above reaction has the following structure.

This is a form in which an alkali metal is contained in pores of carbon nitride, which is a layered structure in which two-dimensional planes in which a triazine ring (CN six-membered ring) is crosslinked by -NH- are stacked. Also, the introduced alkali metal is present in the form of a hydroxide,
Further, since the compound is hydrated, it is considered that the compound contains oxygen and the hydrogen content also increases.

The structure as described above was estimated by comprehensively analyzing the results of element analysis, X-ray diffraction, IR spectrum, fluorescence spectrum, and the like described below.

Table 1 shows the elemental analysis values of the compounds produced under various conditions. Assuming that C ₆ N _α H _β O _γ K _δ , α takes a value exceeding 5, and β and γ take values of 4 or more. , Δ have a value of 0.1 or more.

Next, the results of analysis by the X-ray diffraction method will be described. The X-ray diffraction diagrams of the carbon nitride polymer and the alkali metal compound of carbon nitride represented by C ₆ N _8.7 H _7.9 O _3.9 K _1.0 are shown in FIGS.
As shown in the figure, the measurement conditions were Cu-kα ray, 30 KV,
20mA, scanning speed: 1 ゜ / min, time constant: 1sec, full scale: 10K
cps.

The carbon nitride polymer has a maximum diffraction line having a peak at 2θ of 26.5 to 28.0 °. This indicates that it has a graphite-like layered structure. It is considered that the position of the diffraction line did not change even after the alkali treatment, and the basic structure did not change. This is due to the fact that there are large pores of 0.394 nm each in the unit cell of the in-plane structure of carbon nitride, in which
Since it is considered that K ions of 04 nm, Na ions of 0.226 nm and Li ions of 0.146 nm have been introduced, the layered structure and the interlayer distance do not change.

However, it can be seen that the diffraction line after the alkali treatment became broad and the crystallinity was reduced. This is considered to be because the interlayer distance slightly varies due to the introduction of hydration water.

3 and 4 show IR spectra of the carbon nitride polymer and the compound of the present invention. Carbon nitride polymer is -NH-
Since it contains a group, it has an absorption band at 3200 cm, but after the alkali treatment, an absorption band due to -OH group and water of hydration appears at 3400 cm.

5 and 6 show the fluorescence spectra of the carbon nitride polymer and the compound after the alkali treatment. The carbon nitride polymer is excited by 365 nm ultraviolet light and emits strong fluorescence having a peak at 465 nm, but the compound containing an alkali metal, particularly potassium, shows an intensity twice or more that of that, and the peak width is also increased. It became narrow. Also, the peak position is 43
It shifted to 8 nm and emitted blue light. Since the intensity is large and the peak width is narrow, it is useful for use as a single color light emitting device. Among the alkali metals, the compound containing K had the highest strength, the highest after 1N-KOH treatment, and the strength did not increase even if the concentration was further increased. (7th
(Fig.) Also, like the carbon nitride polymer, an MOH aqueous solution (however,
The compound after the treatment (M = K, Na, Li) is also stable in air.
However, while the carbon nitride polymer was stable up to 400 ° C., the compound containing the alkali metal of the present invention was 200 ° C.
When heated to 300 ° C., decomposition began, and the color changed from white to yellow.

As described above, when the structure of the compound of the present invention is estimated by various analysis methods, it is considered that the compound has the structure described above.

However, the structure of carbon nitride proposed in Japanese Patent Application No. 63-173186 is as follows. In the case of this structure, considering the reaction with the alkali metal, the vacancies surrounded by the three nitrogen atoms of the triazine ring are filled with unpaired electron pairs of nitrogen and are smaller than the vacancies submitted this time. Alkali metal is considered to be difficult to enter.

Further, as a result of re-examination of the data such as the density according to the previous proposal, it is considered that the previously proposed structure is difficult to take and the structure according to the present invention described above is adopted.

As described above, the present invention will be described in more detail with reference to Examples. Example 1 0.3 g of a carbon nitride polymer was added to 100 ml of 1N-KOH aqueous solution.
The mixture was stirred for 12 hours, filtered, washed, and dried at about 100 ° C.

While the original polymer was yellowish white to yellow, it became slightly whitish after the treatment. Table 1 shows the elemental analysis values of the product. The composition of this product was C ₆ N _8.7 H _7.9 O _3.9 K _1.0 , with the introduction of K into the original polymer C ₆ N _9.2 H _4.1 containing oxygen and increasing the hydrogen content at the same time. This is presumably because the introduced K exists in the form of KOH and is hydrated.

This is the ideal structure of carbon nitride [(C ₃ N ₃ ) ₂ (NH)
₃ ] Theoretical composition C ₆ N ₉ H with KOH · 2H ₂ O introduced into the unit cell of _n
It is almost the same as ₈ O ₃ K ₁ .

Example 2 0.3 g of a polymer was added to 100 ml of a 10N-KOH aqueous solution, and the same reaction as in Example 1 was carried out. The analysis results are shown in Table 1.

The reaction product turned whiter than in Example 1. A part was dissolved in the aqueous solution and passed through a 1 μm filter paper. The composition of the filtered product was C ₆ N _5.6 H ₁₃ O ₁₂ K _3.4 , and the nitrogen content was extremely reduced and O, H, and K were increased as compared with the original polymer. Even if it is considered that a part was dissolved, it is considered that the treatment with a concentrated aqueous solution resulted in cleavage of the -NH- group to lower the molecular weight.

Example 3 0.3 g of a polymer was added to 100 ml of 0.1N-KOH aqueous solution, and
And the results of analysis are shown in Table 1.

The color of the product was little different from the original polymer. The composition of the product is C ₆ N _9.3 H _4.2 O _0.61 K _0.11 ,
The contents of K and O were smaller than those in Examples 1 and 2.

Example 4 0.3 g of a polymer was added to 100 ml of an aqueous 1N-NaOH solution, and the same reaction as in Example 1 was carried out. The analysis results are shown in Table 1.

The product became slightly whitish than the original polymer.
The composition of the product was C ₆ N _8.4 H _5.0 O _0.83 Na _0.47 , and the alkali metal content was lower than that of Example 1.

Example 5 0.3 g of a polymer was added to 100 ml of an aqueous 1N-LiOH solution, and the same reaction as in Example 1 was carried out. The analysis results are shown in Table 1.

The color of the product was little different from the original polymer. The composition of the product is C ₆ N _9.2 H _4.2 O _0.49 Li _0.10 ,
When treated at the same concentration, the content of Li was the lowest among K, Na, and Li.

[Effect of the Invention] The compound of the present invention is a completely new alkali metal compound of carbon nitride having a novel chemical composition and structure, and has excellent fluorescent properties, lubricating properties, ion exchange properties, ionic conductivity, etc. It has the property of

[Brief description of the drawings]

1 and 2 are X-ray diffraction diagrams of the carbon nitride polymer and the compound of the present invention. FIGS. 3 and 4 are diagrams showing the IR spectra of the carbon nitride polymer and the compound of the present invention. 5 and 6 show the fluorescence spectra of the carbon nitride polymer and the compound of the present invention, and FIG. 7 shows the relationship between the KOH concentration and the emission intensity and peak half width of the carbon nitride polymer after KOH treatment. .

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-253021 (JP, A) JP-A-2-79047 (JP, A) JP-A-57-11810 (JP, A) JP-A-57-210 145019 (JP, A) JP-A-60-91528 (JP, A) JP-B-5-16364 (JP, B2)

Claims (3)

(57) [Claims] (1) A general formula C ₆ N _α H _β O _γ M _δ (where M =
K, Na, Li, 5.0 ≦ α ≦ 10.0,0 <β, γ ≦ 14.0,0 <δ ≦ 5.0)
An alkali metal compound of carbon nitride having a layered structure represented by (2) Carbon nitride [(C ₃ N ₃ ) ₂ N _x H _y ] (2
≤x≤4,0≤y≤8 and MOH aqueous solution (where M = K, Na, L
i) reacting the compound of the general formula C ₆ N _α H _β O _γ
M _δ (However, M = K, Na, Li, 5.0 ≦ α ≦ 10.0,0 <β, γ
≦ 14.0, 0 <δ ≦ 5.0) A method for producing an alkali metal compound of carbon nitride having a layered structure represented by the formula: 3. A compound of the general formula C ₆ N _α H _β O _γ M _δ (where M =
K, Na, Li, 5.0 ≦ α ≦ 10.0,0 <β, γ ≦ 14.0,0 <δ ≦ 5.0)
A fluorescent material comprising an alkali metal compound of carbon nitride having a layered structure represented by: