TW201326190A - Phosphorous-containing benzoxazine compound, curable composition and cured article - Google Patents

Abstract

A phosphorous-containing benzoxazine compound is represented by the formula (I), wherein Ra to Rq are defined in the specification and claims. The phosphorous-containing benzoxazine compound, when being applied to polymeric materials, can improve the thermal property (e.g. the glass transition temperature, thermal stability or thermal expansion coefficient), the mechanical property (the storage modulus) and the flame retardancy of the polymeric material.

Description

Phosphorus-containing benzoxazine compound, curing composition and cured product

This invention relates to a benzoxazine compound, and more particularly to a phosphorus-containing benzoxazine compound.

A phenol formaldehyde resin is obtained by polycondensation of a phenol compound and an aldehyde compound. Although traditional phenolic resins have good dielectric properties and excellent mechanical properties, they also have some disadvantages, and the application is still limited in the electronics industry. The disadvantages include the following: (1) The residual phenolic group in the structure is easily oxidized and discolored, which is affected by the aesthetics and heat resistance of the subsequent application; (2) The small molecule is easily released due to condensation polymerization during the curing process ( Such as water), resulting in holes and defects in the structure; (3) the product is easy to absorb water, which will cause instability after the use of electrical products such as circuit boards. Therefore, it is necessary to develop alternatives to phenolic resins.

The benzoxazine polymer is one of the phenolic resins currently widely studied, and is characterized by being opened and cured after heating. Compared with traditional phenolic resin, the benzoxazine polymer has the advantages of high glass transition temperature, low moisture absorption rate, good electrical properties and high char yield. When the benzoxazine polymer is used in an electronic product that requires flame retardancy, its flame retardancy is not good, and the electronic product cannot be made into a flame retardant effect. Although the subsequent research hopes to improve the flame retardancy by adding a flame retardant, this method not only has the problem of mixing uniformity and compatibility, but also uses a halogen flame retardant to generate corrosive gas in addition to burning. In addition, harmful carcinogenic gases such as benzofuran are also produced.

TW200936602 discloses a phosphorus-containing compound which is represented by the formula (1):

In the formula (1), r ¹ and r ² may independently be hydrogen, C ₁ -C ₄ alkyl, -CF ₃ , -OCF ₃ , phenyl, halogen, phenoxy, C ₃ -C ₇ naphthenic. a group or a C ₁ -C ₄ alkoxy group; and x is a carboxyl group or a hydroxyl group. The phosphorus-containing compound is applied to the polymer material in the subsequent application. Although the polymer material has better flame retardancy, the glass transition temperature gradually decreases with the increase of the phosphorus content, and is not suitable for the subsequent processing. However, since it is only bonded to the polymer material through the ring opening itself, the network structure formed has a low crosslink density, and the properties of the polymer material (such as the coefficient of thermal expansion or the glass transition temperature) cannot be effectively improved.

Therefore, the use of molecular design to develop a phosphorus-containing compound having better flame retardancy, mechanical properties and thermal properties has become one of the goals of the research in the art.

Therefore, the first object of the present invention is to provide a phosphorus-containing benzoxazine compound which can be used in a polymer material to improve and improve the thermal properties of the polymer material (such as glass transition temperature and thermal stability). Or thermal expansion coefficient), mechanical properties (storage modulus) and flame retardancy.

Thus, the phosphorus-containing benzoxazine compound of the present invention is represented by the following formula (I):

In the formula (I), R ^a to R ^h are the same or different and each represents hydrogen or a C ₁ -C ₆ alkyl group; R ⁱ to R ^q represent hydrogen, a C ₁ -C ₆ alkyl group,

And the condition is that at least one of R ⁱ to R ^q represents ; n ₁ to n ₆ represent an integer of 0 to 12.

A second object of the invention is to provide a cured composition.

Thus, the cured composition of the present invention comprises a phosphorus-containing benzoxazine-based compound as described above.

A third object of the present invention is to provide a cured product.

Thus, the cured product of the present invention is obtained by subjecting a cured composition as described above to a curing treatment.

The effect of the present invention is that the phosphorus-containing benzoxazine compound of the present invention contains phosphorus which enhances flame retardancy and an unsaturated group which can increase the crosslinking density [e.g., propargyl ether, propylene). Alyl ether, nitrile ether, etc., when subsequently applied to a polymer material, the unsaturated group can be bonded to the polymer material, thereby enhancing the thermal properties of the polymer material (eg, Glass transition temperature, thermal stability or coefficient of thermal expansion) and mechanical properties (storage modulus), while introducing phosphorus into the polymer material, can improve the flame retardancy of the polymer material.

The phosphorus-containing benzoxazine compound of the present invention is represented by the formula (I):

In the formula (I), R ^a to R ^h are the same or different and each represents hydrogen or a C ₁ -C ₆ alkyl group; R ⁱ to R ^q represent hydrogen, a C ₁ -C ₆ alkyl group,

And the condition is that at least one of R ⁱ to R ^q represents ,or ;n ₁ to n ₆ represent an integer of 0 to 12.

Preferably, in the formula (I), R ⁿ to R ^q represent hydrogen.

Preferably, in the formula (I), R ⁱ to R ^m represent hydrogen.

Preferably, in the formula (I), R ^a to R ^h represent hydrogen, R ⁿ to R ^q represent hydrogen, and at least one of R ⁱ to R ^m represents And the rest represents hydrogen.

Preferably, in the formula (I), at least one of the R ⁱ to R ^m represents At least one of R ⁿ to R ^q represents And the rest represents hydrogen.

Preferably, in the formula (I), at least one of the R ⁱ to R ^m represents At least one of R ⁿ to R ^q represents And the rest represents hydrogen.

Preferably, in the formula (I), at least one of the R ⁱ to R ^m represents At least one of R ⁿ to R ^q represents And the rest represents hydrogen.

Specific examples of the phosphorus-containing benzoxazine compound of the present invention, for example

The phosphorus-containing benzoxazine compound of the present invention contains phosphorus which enhances flame retardancy and an unsaturated group which can increase the crosslinking density [e.g., propynyl ether group, propylene ether group, cyanocyano group, etc.], When subsequently applied to a polymer material, the unsaturated group can be bonded to the polymer material, thereby improving the glass transition temperature and thermal stability of the polymer material and effectively reducing the coefficient of thermal expansion, and simultaneously introducing phosphorus into the polymer material. Inside, it can improve the flame retardancy of polymer materials.

The method for preparing a phosphorus-containing benzoxazine compound of the present invention comprises the steps of: reacting a compound represented by the formula (II) with a halogenated unsaturated compound to obtain the phosphorus-containing benzoxazine-based compound, Wherein the halogenated unsaturated compound is selected from a halogenated olefinic compound, a halogenated acetylenic compound, or a halogenated nitrile compound;

In the formula (II), X ^a to X ^h are the same or different and each represents hydrogen or a C ₁ -C ₆ alkyl group; X ⁱ -X ^q represents hydrogen, a C ₁ -C ₆ alkyl group, -OH Or -SH, and the condition is that at least one of X ⁱ to X ^q represents -OH or -SH.

The halogenated acetylene compound is And X represents halogen and m ₁ represents an integer of 0 to 12.

The halogenated olefinic compound is And X represents halogen and m ₂ represents an integer of 0 to 12.

The halogenated nitrile compound is And X represents halogen and m ₃ represents an integer of 0 to 12.

Preferably, the compound represented by the formula (II) is a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 oxide compound, a 2-hydroxybenzaldehyde compound (2-hydroxybenzaldehyde). And the aniline compound is obtained by a ring closure reaction in the presence of formaldehyde; the 2-hydroxybenzaldehyde compound and the aniline compound have a first reactive group, and the first reactive group represents - OH or -SH.

Preferably, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide compound is of the formula ( III):

In the formula (III), R ¹¹ to R ¹⁸ are the same or different and each represents hydrogen or a C ₁ -C ₆ alkyl group.

Preferably, the 2-hydroxybenzaldehyde compound is represented by the following formula (IV):

In the formula (IV), R ²¹ to R ²⁴ are the same or different and each represents hydrogen, a C ₁ -C ₆ alkyl group, -OH or -SH.

Preferably, the aniline compound is represented by the following formula (V):

In the formula (V), R ³¹ to R ³⁵ are the same or different and each represents hydrogen, a C ₁ -C ₆ alkyl group, -OH or -SH.

In the formula (IV), R ²¹ to R ²⁴ and R ³¹ to R ³⁵ in the formula (V) are required to match each other. When R ²¹ to R ²⁴ are all hydrogen, at least one of R ³¹ to R ³⁵ is -OH or -SH; in other words, when R ³¹ to R ³⁵ are all hydrogen, at least one of R ²¹ to R ²⁴ is -OH or -SH.

The cured composition of the present invention comprises a phosphorus-containing benzoxazine-based compound as described above.

The cured product of the present invention is obtained by subjecting a cured composition as described above to a curing treatment. Preferably, the phosphorus content in the cured product ranges from 0.5% by weight to 4.0% by weight.

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

< EXAMPLES [Preparation of Phosphorus-Containing Benzooxazine Compounds] <Example 1>

Take 12.97 g (0.06 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 oxide (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide, hereinafter referred to as DOPO), 6.55 g (0.06 mol) of 4-aminophenol, 7.33 g (0.06 mol) of 2-hydroxybenzaldehyde were placed in a three-neck reaction flask, and methanol was added and stirred to dissolve at 30 After reacting for 8 hours at ° C, 8.9 g (0.11 mol) of 37 wt% aqueous formaldehyde solution was dropped into the reaction flask, and after reacting for 4 hours at room temperature, the temperature was raised to reflux temperature, and the reaction was continued for 12 hours. hour. After the reaction, the filter cake was filtered and taken out, and the filter cake was washed with 1000 ml of deionized water, followed by filtration using an air suction filter. The resulting filter cake was dried using a vacuum oven at 110 ° C. The filter cake weighed 23.8 g and the yield was 90%.

The above 4.41 g (0.01 mol) filter cake, 2.07 g (0.015 mol) potassium carbonate, 1.78 g (0.012 mol) of bromopropyne were placed in a three-neck reaction flask and nitrogen, nitrogen-dimethyl was added. N, N-dimethylacetamide (hereinafter referred to as DMAc) was dissolved, followed by a reaction at 80 ° C for 24 hours. After the reaction, the temperature is lowered to room temperature, and the filtrate is filtered to obtain a brown powder product. The brown powder product is obtained by suction filtration, and further dried. The product weighs 4.21 g. The rate was 88%, the melting point was 174 ° C, and the exothermic peak was 255 ° C. The structural formula is as follows. ¹ H NMR (400 MHz, CDCl ₃ , 298 K), δ (ppm): 2.4 (1H), 4.5 (2H), 4.7 (1H), 4.9 to 5.3 (2H), 6.6 to 8.0 (16H).

<Example 2>

12.97 g (0.06 mol) of DOPO, 6.55 g (0.06 mol) of 4-aminophenol, 7.33 g (0.06 mol) of 2-hydroxybenzaldehyde were placed in a three-necked reaction flask, and methanol was added. After stirring for 30 hours at 30 ° C, 8.9 g (0.11 mol) of 37 wt% aqueous formaldehyde solution was dropped into the reaction flask, and the temperature was raised after reacting for 4 hours at room temperature. The temperature was refluxed and the reaction was continued for 12 hours. After the reaction, the filter cake was filtered and taken out, and the filter cake was washed with 1000 ml of deionized water, followed by filtration using an air suction filter. The resulting filter cake was dried using a vacuum oven at 110 ° C. The filter cake weighed 23.8 g and the yield was 90%.

The above 4.41 g (0.01 mol) filter cake, 2.07 g (0.015 mol) potassium carbonate, 1.49 g (0.012 mol) of bromopropene were placed in a three-neck reaction flask and dissolved by adding DMAc, followed by The reaction was carried out at 80 ° C for 24 hours. After the reaction, the temperature was lowered to room temperature, and the filtrate was filtered, and then deionized water was added, and a brown powder product was precipitated. The brown powder product was obtained by suction filtration, and further dried, and the product weighed 4.14 g. The rate is 86% and its structural formula is as follows. ¹ H NMR (400 MHz, CDCl ₃ , 298 K), δ (ppm): 4.4 (2H), 5.0-5.4 (5H), 5.9 (1H), 6.6-8.4 (16H).

<Example 3>

12.97 g (0.06 mol) of DOPO, 6.55 g (0.06 mol) of 4-aminophenol, and 8.28 g (0.06 mol) of 2,4-dihydroxybenzaldehyde were placed in a three-necked reaction flask, and Methanol was added and stirred to dissolve. After reacting at 30 ° C for 8 hours, 8.9 g (0.11 mol) of 37 wt% aqueous formaldehyde solution was dropped into the reaction flask, and reacted at room temperature for 4 hours, and then The temperature was raised to reflux temperature and the reaction was continued for 12 hours. After the reaction, the filter cake was filtered and taken out, and the filter cake was washed with 1,000 ml of deionized water, followed by filtration using an air suction filter. The resulting filter cake was dried using a vacuum oven at 110 ° C. The filter cake weighed 24.15 g and the yield was 88%.

The above 4.57 g (0.01 mol) filter cake, 2.07 g (0.015 mol) of potassium carbonate, 3.56 g (0.024 mol) of bromopropyne were placed in a three-necked reaction flask and DMAc was added to dissolve it, followed by dissolution. The reaction was carried out at 80 ° C for 24 hours. After the reaction, the temperature is lowered to room temperature, and the filtrate is filtered to obtain a brown powder product. The brown powder product is obtained by suction filtration, and further dried. The product is 4.53 g. The rate is 85% and its structural formula is as follows. ¹ H NMR (400 MHz, CDCl ₃ , 298 K), δ (ppm): 2.4 (2H), 4.5 (4H), 4.7 (1H), 4.9 to 5.3 (2H), 6.5 to 8.0 (15H).

<Example 4>

12.97 g (0.06 mol) of DOPO, 6.55 g (0.06 mol) of 4-aminophenol, and 8.28 g (0.06 mol) of 2,4-dihydroxybenzaldehyde were placed in a three-necked reaction flask, and Methanol was added and stirred to dissolve. After reacting at 30 ° C for 8 hours, 8.9 g (0.11 mol) of 37 wt% aqueous formaldehyde solution was dropped into the reaction flask, and reacted at room temperature for 4 hours, and then The temperature was raised to reflux temperature and the reaction was continued for 12 hours. After the reaction, the filter cake was filtered and taken out, and the filter cake was washed with 1000 ml of deionized water, followed by filtration using an air suction filter. The resulting filter cake was dried using a vacuum oven at 110 ° C. The filter cake weighed 28.02 g and the yield was 85%.

The above 4.57 g (0.01 mol) filter cake, 2.07 g (0.015 mol) of potassium carbonate, 2.98 g (0.024 mol) of bromopropene were placed in a three-neck reaction flask and dissolved by adding DMAc, followed by The reaction was carried out at 80 ° C for 24 hours. After the reaction, the temperature was lowered to room temperature, and the filtrate was filtered to obtain a brown powder product. The brown powder product was precipitated by suction filtration, and further dried. The product weighed 4.34 g. The rate is 81% and its structural formula is as follows. ¹ H NMR (400 MHz, CDCl ₃ , 298 K), δ (ppm): 4.4 (4H), 5.0-5.4 (7H), 6.0 (2H), 6.5-8.0 (15H).

<Comparative Example 1>

12.97 g (0.06 mol) of DOPO, 6.55 g (0.06 mol) of 4-aminophenol, 7.33 g (0.06 mol) of 2-hydroxybenzaldehyde were placed in a three-necked reaction flask, and methanol was added. After stirring for 30 hours at 30 ° C, 8.9 g (0.11 mol) of 37 wt% aqueous formaldehyde solution was dropped into the reaction flask, and the temperature was raised after reacting for 4 hours at room temperature. The temperature was refluxed and the reaction was continued for 12 hours. After the reaction, the filter cake was filtered and taken out, and the filter cake was washed with 1,000 ml of deionized water, followed by filtration using an air suction filter. The resulting filter cake was dried using a vacuum oven at 110 ° C. The filter cake weighed 23.8 g and the yield was 90%. Finally, the chemical structure of the filter cake was identified as follows:

<Application Example> Curing composition and cured product <Application Example 1>

10 g of bis(benzoxazine)methane was heated on a hot plate to 160 ° C in a molten state, and then 0.084 g of the product of Example 1 was added and stirred uniformly to form a solidified composition, which was then poured into a mold. Then, it is heated in an oven to be cured to obtain a cured product, wherein the heating process is heating at 180 ° C for 2 hours → heating at 200 ° C for 2 hours → heating at 220 ° C for 2 hours → heating at 240 ° C for 1 hour . The phosphorus content in the cured product was 0.5 wt%. The chemical structure of the bis(benzoxazine) methane is

<Application Examples 2 to 5>

In Application Examples 2 to 5, the cured composition and the cured product were prepared in the same manner as in Application Example 1, except that the amount of the product of Example 1 was changed. The amount of the product of the first embodiment and the evaluation results of the test items of the cured products are shown in Table 1.

<Comparative Application Example 1>

10 g of bis(benzoxazine)methane was heated to 150 ° C on a hot plate to be in a molten state, and then poured into a mold, followed by heating in an oven to harden it to obtain a cured product, wherein The heating course was heating at 180 ° C for 2 hours → heating at 200 ° C for 2 hours → heating at 220 ° C for 2 hours → heating at 240 ° C for 1 hour.

<Comparative Application Example 2>

10 g of bis(benzoxazine)methane was heated to 160 ° C on a hot plate to be in a molten state, and 1.19 g of Comparative Example 1 was added and stirred uniformly, and then poured into a mold, followed by heating in an oven. It was solidified to obtain a cured product in which the heating course was heating at 180 ° C for 2 hours → heating at 200 ° C for 2 hours → heating at 220 ° C for 2 hours → heating at 240 ° C for 1 hour. The phosphorus content in the cured product was 0.75 wt%.

<Comparative Application Examples 3 to 5>

Comparative Examples 3 to 5 were prepared in the same manner as in Comparative Application Example 2, except that the amount of the product of Comparative Example 1 was changed. The amount of the product of Comparative Example 1 and the evaluation results of the test items of the cured products are shown in Table 1.

[ Test items ]

1. Thermogravimetric Analysis (TGA): The cured product of Application Examples 1 to 5 and the cured product of Comparative Application Example 1 were respectively analyzed using a Thermo Cahn Versa Therm machine, and the analysis conditions were as follows: nitrogen and air. In a mixed environment, the flow rate of the mixed gas is 100 mL/min, the temperature is raised from 100 ° C to 800 ° C, and the heating rate is 20 ° C / min, and the thermal decomposition temperature of the cured product at a loss of 5 wt % is measured ( T _d , ° C).

2. Dynamic mechanical analyzer (DMA): The cured product of Application Examples 1 to 5 and the cured product of Comparative Application Example 1 were analyzed using a Perkin-Elmer Pyris Diamond machine, and the heating rate was 5 ° C / min, frequency. The storage modulus (E', Pa) and loss tangent (Tan δ) of the cured products were measured at 1 Hz and amplitude of 25 μm.

3. Thermal mechanical analysis (TMA): The cured products of Application Examples 1 to 5 and the cured product of Comparative Application Example 1 were analyzed using a Perkin-Elmer Pyris Diamond machine, and the analysis conditions were as follows: in a nitrogen atmosphere Next, the heating rate was 5 ° C / min, and the thermal expansion coefficients (CTE, ppm / ° C) and glass transition temperatures (T _g , ° C) of the cured materials were measured.

4. High coke residual yield: From the curve measured in the above test item 1, a high coke residual amount (wt%) at 800 ° C was obtained.

5. Flame retardancy measurement: The cured compositions of Application Examples 1 to 5 and the cured compositions of Comparative Application Example 1 were placed in a hollow mold having a length of 127 mm, a width of 12.7 mm, and a height of 1.27 mm, respectively, and placed in a high-temperature oven. After curing, after the molding is completed, a rectangular parallelepiped test piece can be obtained.

During the test, the rectangular test piece of the rectangular parallelepiped is fixed at one end, and the other end is heated by the Bunsen burner. After heating for 10 seconds, the fire source is removed. If it is not burned or extinguished within 30 seconds, wait for a while, and wait for a rectangular shape. The test piece was no longer hot. Then, the cuboid test piece of the rectangular parallelepiped was heated for 10 seconds, and then the fire source was removed to record the time of secondary combustion.

The method for judging the level is as follows:

(a) V-0: The rectangular test piece of the rectangular parallelepiped has a first burning time of t ₁ second, and the material of the drooping does not burn the cotton at the bottom, and the second burning time is t ₂ seconds. If t ₁ + t ₂ < 10 seconds, it is V-0 level.

(b) V-1: The rectangular test piece of the cuboid is burned for less than 30 seconds for the first time, and does not burn to the upper end of the fixed clamp. The material of the drip does not burn the cotton at the bottom, and the second burning time does not exceed 30 seconds.

(c) V-2: Judging the same as V-1, but the material of the drip will cause the bottom cotton to burn.

From the results of the data of Application Examples 1 to 5 of Table 1, it is understood that the phosphorus-containing benzoxazine-based compound of the present invention is added to bis(benzoxazine)methane and solidified, along with the phosphorus-containing benzoxazine-based compound. The addition amount increases, and the glass transition temperature (220 ° C ~ 237 ° C) and thermal cracking temperature (418 ° C ~ 440 ° C) of the cured product gradually increase, and the thermal expansion coefficient of the cured product (37 ppm / ° C ~ 40 ppm / ° C The gradual decrease indicates that the addition of the phosphorus-containing benzoxazine-based compound of the present invention allows the cured product to have better thermal properties. Further, the flame retardancy of the cured product increases the total amount of combustion as the phosphorus content increases, indicating that the addition of the phosphorus-containing benzoxazine-based compound of the present invention can enhance the flame retardancy of the cured product.

Compared with the data of Comparative Application Example 1, the cured product formed by bis(benzoxazine) methane has not only a low glass transition temperature (208 ° C), but also a high coefficient of thermal expansion (50 ppm / ° C), and its solidification The flame retardancy of the object is not good.

Further, compared with the data results of Comparative Application Examples 2 to 5, the phosphorus-containing compound of TW200936602 was added to bis(benzoxazine)methane and solidified, and as the amount of the phosphorus-containing compound added increased, not only the curing could not be improved. The glass transition temperature and the thermal cracking temperature of the material, at the same time, the thermal expansion coefficient of the cured product is not effectively lowered, and the flame retardancy of the cured product is not good.

3 and 4 are analysis diagrams of dynamic mechanical properties of the cured products of Application Examples 1 to 5 and the cured product of Comparative Application Example 1. Referring to FIG. 3, the curves are the storage modulus of the cured products, and the cured products of the application examples 1 to 5 of the present invention have good mechanical properties; and referring to FIG. 4, the curves are glass transitions of the cured products. The temperature shows that the cured product of Application Examples 1 to 5 of the present invention has a relatively high glass transition temperature and can be operated at a high temperature of about 150 °C to 220 °C.

In summary, the phosphorus-containing benzoxazine compound of the present invention contains phosphorus which enhances flame retardancy and an unsaturated group which can increase the crosslinking density (for example, propynyl ether group, propylene ether group, and cyanogen). The ether group, etc., is subsequently applied to the polymer material, and the unsaturated group can be bonded to the polymer material, thereby improving the thermal properties (such as glass transition temperature, thermal stability or thermal expansion coefficient) and mechanical properties of the polymer material. (Storage modulus), at the same time, the introduction of phosphorus into the polymer material can improve the flame retardancy of the polymer material, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1 is an NMR chart illustrating a structural analysis diagram of a phosphorus-containing benzoxazine-based compound of Example 1 of the present invention;

Figure 2 is an NMR chart showing the structural analysis of the phosphorus-containing benzoxazine-based compound of Example 2 of the present invention;

3 is a graph showing the storage modulus of the cured product of the preferred application example of the present invention and the cured product of Comparative Application Example 1;

Fig. 4 is a graph showing the glass transition temperature of the cured product of the preferred application of the present invention and the cured product of Comparative Application Example 1.

Claims (10)

A phosphorus-containing benzoxazine compound is represented by the formula (I): In the formula (I), R ^a to R ^h are the same or different and each represents hydrogen or a C ₁ -C ₆ alkyl group; R ⁱ to R ^q represent hydrogen, a C ₁ -C ₆ alkyl group, And the condition is that at least one of R ⁱ to R ^q represents n ₁ to n ₆ represent an integer of 0 to 12. The phosphorus-containing benzoxazine-based compound according to the first aspect of the invention, wherein, in the formula (I), R ⁿ to R ^q represent hydrogen. The phosphorus-containing benzoxazine-based compound according to the first aspect of the invention, wherein, in the formula (I), R ⁱ to R ^m represent hydrogen. The phosphorus-containing benzoxazine-based compound according to the first aspect of the invention, wherein, in the formula (I), R ^a to R ^h represent hydrogen, R ⁿ to R ^q represent hydrogen, and the R ⁱ ～ At least one of R ^m represents And the rest represents hydrogen. The phosphorus-containing benzoxazine-based compound according to claim 1, wherein in the formula (I), at least one of the R ⁱ to R ^m is represented by At least one of R ⁿ to R ^q represents And the rest represents hydrogen. The phosphorus-containing benzoxazine-based compound according to claim 1, wherein in the formula (I), at least one of the R ⁱ to R ^m is represented by At least one of R ⁿ to R ^q represents And the rest represents hydrogen. The phosphorus-containing benzoxazine-based compound according to claim 1, wherein in the formula (I), at least one of the R ⁱ to R ^m is represented by At least one of R ⁿ to R ^q represents And the rest represents hydrogen. A curing composition comprising a phosphorus-containing benzoxazine-based compound according to any one of claims 1 to 7. A cured product obtained by curing a cured composition as described in claim 8 of the application. The cured product according to claim 9, wherein the content of phosphorus in the cured product ranges from 0.5% by weight to 4.0% by weight.