JP2022152831A - Method for producing benzoxazine compound - Google Patents

Abstract

To provide a new production method for a benzoxazine compound that is excellent in reaction time, product yield, and environmental load.SOLUTION: A method for producing a benzoxazine compound according to an embodiment includes a reaction step for heating a mixture of phenol, a predetermined diamine, and paraformaldehyde for a reaction, the mixture having a solid content of 80-100 wt.%.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a method for producing a benzoxazine-based compound.

Conventionally, benzoxazine compounds are mainly synthesized by a method using a solution (solution method).

For example, Patent Document 1 discloses a method for producing a compound having a dihydrobenzoxazine ring, in which a mixture of a specific bisphenol compound and formaldehyde is reacted while gradually adding a primary amine.

Further, Patent Document 2 discloses a manufacturing method in which a specific bisphenol compound, paraformaldehyde, and an amine compound are mixed and heat-treated in the presence of a specific solvent.

Furthermore, Non-Patent Document 1 discloses a method for producing polybenzoxazine, in which diamine and phenol are reacted in toluene/ethanol.

On the other hand, there is also a method for producing a benzoxazine-based compound that does not use a solvent. For example, Patent Document 3 discloses a method for producing a benzoxazine monomer using phenol, paraformaldehyde, and m-cresol as substrates.

Japanese Patent Application Laid-Open No. 2004-217941 Japanese Unexamined Patent Application Publication No. 2012-126900 U.S. Publication No. 2017/0166537

Sarychev et al. "Benzoxazine monomers based on aromatic diamines and investigation of their polymerization by rheological and thermal methods" J Appl Polym Sci. 2020

However, the above-described method for producing a benzoxazine-based compound has room for improvement in terms of reaction time, product yield, and environmental load. One embodiment of the present invention has been made in view of the above problems, and the object thereof is to shorten the reaction time compared to the conventional production method, and to achieve a yield of a benzoxazine compound equal to or higher than that of the conventional method, Another object of the present invention is to provide a new method for producing a benzoxazine-based compound, which has a low environmental load because the present production method uses less solvent than the conventional production method using a solvent.

As a result of extensive studies to solve the above problems, the present inventors have found that phenol, a diamine having a specific structure, and paraformaldehyde are heated and reacted at a solid content concentration higher than that of the solution method. The inventors have found that a benzoxazine-based compound can be produced by a method that is superior in reaction time, product yield, and environmental load, and have completed the present invention. That is, one aspect of the present invention includes the following configurations.

<1> A mixture of (A) phenol, (B) an amine-based composition containing a diamine represented by the following general formula (1) and a monoamine as an optional component, and (C) paraformaldehyde is heated and reacted. A method for producing a benzoxazine-based compound, wherein the mixture has a solid content concentration of 80 to 100% by weight.

In formula (1), R1 is represented by the following general formula (2).

In formula (2), L1 and L3 are O (ether bond), L2 is O (ether bond), C═O, SO ₂ , C(CH ₃ ) ₂ , C(CF ₃ ) ₂ , or CH ₂ and p, q, r, s, and t are 0 or 1. However, p+q+r+s+t≧1, p or q is 0 when s=0, and q or r is 0 when t=0.

<2> The method for producing a benzoxazine-based compound according to <1>, wherein the heating temperature is 90° C. or higher in the reaction step.

<3> The method for producing a benzoxazine-based compound according to <1> or <2>, wherein the heating time in the reaction step is 5 hours or less.

<4> The benzoxazine system according to any one of <1> to <3>, wherein the mixture contains (D) a solvent having a boiling point of 100° C. or higher in an amount of more than 0% by weight and less than 20% by weight. A method for producing a compound.

<5> The solvent (D) includes N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), 1,4-dioxane, toluene, and acetic acid. The method for producing a benzoxazine-based compound according to <4>, wherein the compound is at least one selected from the group consisting of n-butyl and diethyl carbonate.

<6> Any of <1> to <5>, further comprising a purification step of washing the reaction product when the solid content concentration of the product is less than 100% by weight at the time the reaction step is completed. A method for producing the described benzoxazine-based compound.

<7> The method for producing a benzoxazine-based compound according to any one of <1> to <6>, wherein the diamine has a melting point of 60° C. or higher.

<8> The method for producing a benzoxazine-based compound according to any one of <1> to <6>, wherein the diamine is one or more selected from compounds represented by the following formulas (3) to (16).

<9> A mixture of (A1) a monophenol-based composition containing phenol, (B1) an amine-based composition containing a diamine and an optional monoamine, and (C) paraformaldehyde, or (A2) bisphenol and (B2) a monoamine composition containing aniline, and (C) a mixture of paraformaldehyde and heating to react, wherein the mixture has a solid content concentration of 80 to 100 % by weight, method for producing a benzoxazine-based compound.

According to one aspect of the present invention, there is provided a new method for producing a benzoxazine-based compound that can shorten the reaction time, improve the yield of the product, and reduce the environmental load compared to conventional methods. can be done.

[1. Method for producing benzoxazine-based compound]
A method for producing a benzoxazine-based compound according to one embodiment of the present invention (hereinafter also referred to as the present production method) comprises (A) phenol, (B) a diamine represented by the following general formula (1), and an optional component A reaction step of heating and reacting a mixture of an amine-based composition containing a monoamine as and (C) paraformaldehyde, and the solid content concentration of the mixture is 80 to 100% by weight. Here, (B) the amine-based composition contains 30 to 100% by weight of a diamine represented by the following general formula (1) and 70 to 0% by weight of a monoamine, preferably represented by the following general formula (1): 50 to 100% by weight of the diamine represented by the formula (1) and 50 to 0% by weight of the monoamine, more preferably 70 to 100% by weight of the diamine represented by the following general formula (1) and 30 to 0% by weight of the monoamine. It is a thing.

In formula (1), R1 is represented by the following general formula (2).

In formula (2), L1 and L3 are O, L2 is O, C=O, SO2, C( _CH3 ) ₂ , _C ( _CF3 ) ₂ , or _CH2 , p, q, r, s, and t are 0 or 1; However, p+q+r+s+t≧1, p or q is 0 when s=0, and q or r is 0 when t=0.

As described above, the inventors of the present invention reduce the amount of solvent used when producing benzoxazine-based compounds, and set the solid content concentration (SC) of the raw material to 80 to 100% by weight, which is higher than that of the conventional solution method. We succeeded in shortening the reaction time and increasing the yield of the resulting benzoxazine compound. In addition, this can reduce the amount of by-products or unreacted substances, resulting in an increase in the consumption of paraformaldehyde. The technique for producing a benzoxazine-based compound based on such an idea is unprecedented and surprising.

In the present specification, "environmental load is low" can be evaluated based on the ratio of paraformaldehyde remaining at the end of the reaction process. It can be evaluated that the smaller the amount of paraformaldehyde remaining at the end of the reaction process, the lower the environmental load. Aside from that, "low environmental impact" also means that a small amount of solvent can be used in the production of the benzoxazine-based compound.

<1-1. Reaction process>
This production method has a reaction step of heating and reacting a mixture of (A) phenol, (B) an amine-based composition containing a diamine represented by the general formula (1), and (C) paraformaldehyde. .

In the reaction step, for example, raw materials (A) phenol, (B) an amine-based composition, and (C) paraformaldehyde are mixed to form a mixture, which is then charged into a three-necked flask or the like and heated. carried out by

In the above reaction step, when (B) the amine-based composition consists only of diamine, the molar ratio of (A) phenol:the diamine:(C) paraformaldehyde is 2:1:4 to 2:1:6. Preferably. If the molar ratio is within the above range, the yield of the product is excellent. Here, when the (B) amine-based composition contains a monoamine, 2 mol of monoamine is converted to 1 mol of diamine, and after adding the number of moles with diamine, the molar ratio can be calculated. As for the order of addition of the amine-based composition, the diamine and the monoamine may be added at the same time and reacted, or the monoamine may be added first, and then the diamine may be added after partial reaction. When the monoamine is added first, it is possible to suppress the formation of gel due to the reaction between the diamine and paraformaldehyde.

In the above reaction step, the heating temperature is preferably 90° C. or higher, more preferably 100° C. or higher, still more preferably 120° C. or higher, and most preferably 130° C. or higher. If the temperature during the heating reaction is 80° C. or higher, it can exceed the melting point of the diamine used in the production method, so that the diamine can be melted and the efficiency of the reaction process is improved. Although the upper limit of the temperature during the heating reaction is not particularly limited, it may be, for example, 250° C. or lower.

In the above reaction step, the heating time is preferably 5 hours or less, more preferably 4 hours or less, still more preferably 3 hours or less, and most preferably 2 hours or less. If the time for performing the reaction step is within the above range, the production efficiency of the benzoxazine-based compound is improved because it is shorter than the conventional production method. The lower limit of the heating time is not particularly limited as long as the raw material can be sufficiently heated and reacted, but may be, for example, 20 minutes or longer.

The method for determining the heating time in the reaction step is not particularly limited, but for example, it can be determined based on the consumption of the raw material (A) phenol. (A) When the heating time is determined based on the consumption of phenol, the heating time may be a time during which 90% or more of (A) phenol is expected to be consumed. (A) The consumption of phenol can be measured by 1H-NMR.

In the reaction step, the mixture is preferably stirred while being heated. Stirring can be performed by, for example, a stirring blade, a magnetic stirrer, a shaker, or the like, but is not limited thereto.

The mixture may be preheated in advance before performing the reaction step. Preheating facilitates the dispersion of (A) phenol and (B) the amine-based composition containing the diamine. Although the preheating temperature is not particularly limited, it may be, for example, about 30 to 70.degree.

In the reaction step of the production method, SC is more preferably more than 80% by weight and less than 100% by weight, more preferably 85-99% by weight, most preferably 90-98% by weight. In the present specification, "solid content concentration (SC)" means that (B) the amine-based composition containing the diamine, (A) phenol, and (C) paraformaldehyde in the present production method are all solid. It is the percentage of solids in the mixture, if hypothesized. In the reaction step of the present production method, when the SC is 80% by weight or more, the concentration of the raw materials is high, so the time required for the reaction is shortened, and the yield of the obtained benzoxazine-based compound is improved. In the reaction step of this production method, SC can be adjusted, for example, by adding a solvent to the above mixture.

In the reaction step of the production method, the mixture preferably contains (D) a solvent having a boiling point of 100° C. or higher in an amount of more than 0% by weight and less than 20% by weight. The amount of the solvent (D) used is more preferably 1 to 15% by weight, more preferably 2 to 10% by weight. If the amount of the solvent (D) used is less than 20% by weight, the concentration of the raw materials will be high, so the time required for the reaction will be shortened and the yield of the resulting benzoxazine-based compound will be improved. Moreover, when the amount of the solvent (D) used is more than 0% by weight, the following advantages are obtained. For example, raw materials that do not melt at the reaction temperature of a normal melting method (manufacturing method that does not use a solvent), that is, have a high melting point can be used. In addition, although each raw material is melted in the melting method, there may be raw materials that are difficult to react because they form a heterogeneous phase when combined. Combinations of such ingredients can also be used as long as the amount of the solvent used is greater than 0% by weight.

The boiling point of the solvent (D) is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. When the boiling point of the solvent (D) is within the above range, the solvent (D) in the reactant does not evaporate during the heating reaction, and the solvent (D) continues to exist in the reactant, resulting in stability of the reaction. Excellent for

The solvent (D) may be either an organic solvent or an aqueous solvent, but is preferably an organic solvent from the viewpoint of the above boiling point.

Examples of the solvent (D) include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), 1,4-dioxane, toluene, and acetic acid. It may be one or more selected from the group consisting of n-butyl and diethyl carbonate. Among these, the solvent (D) is preferably NMP from the viewpoint of high solubility of the raw material.

(diamine)
The (B) amine-based composition used in this production method contains a diamine represented by the following general formula (1).

In formula (1), R1 is represented by the following general formula (2).

In formula (2), L1 and L3 are O, L2 is O, C=O, SO2, C( _CH3 ) ₂ , _C ( _CF3 ) ₂ , or _CH2 , p, q, r, s, and t are 0 or 1; However, p+q+r+s+t≧1, p or q is 0 when s=0, and q or r is 0 when t=0.

In the above diamine, the amino group may be in any of para-, ortho-, and meta-positions with respect to R1. Each amino group may have the same coordination or different coordination with respect to R1. Thus, for example, both amino groups may be para to R1, or one amino group may be meta and the other para. Among these, either both amino groups are para to R, both amino groups are meta to R, or one amino group is meta and the other Para position is preferred. It is also more preferred that both amino groups are para to R1 or one amino group is meta and the other is para. Furthermore, it is most preferred that both amino groups are para to R1.

In the above formula (2), the coordination of L1, L2 and L3 is not particularly limited. That is, as in the case of formula (1), L1 and L3 may be para-, ortho-, or meta-positions relative to L2.

In the above formula (2), p to t are 0 or 1. Portions having a value of 0 among the above p to t are single bonds between carbon atoms. That is, for example, when q is 0, the carbon atoms of the benzene rings on both sides of L2 are single-bonded. Also in this case, the coordination is not particularly limited. That is, the benzene ring to which L3 is bound may be at any of the para-position, ortho-position, and meta-position with respect to L1. Moreover, in the above formula (2), p+q+r+s+t≧1. That is, p to t are not all 0. That is, the benzene rings of formula (1) are not directly bonded to each other.

In the above formula (2), p or q is 0 when s=0. Also, when t=0, q or r is 0. That is, L1 (ether bond) and L2 are not continuous, and L2 and L3 (ether bond) are not continuous.

The diamine preferably has a melting point of 60° C. or higher, more preferably 80° C. or higher, and even more preferably 100° C. or higher. When the melting point of the diamine is within the above range, the reactivity is excellent, and the production efficiency of the benzoxazine-based compound is improved. Although the upper limit of the melting point of the diamine is not particularly limited, it may be 250° C. or lower in reality.

Specifically, the diamine may be one or more selected from the following compounds.

1,3-bis(4-aminophenoxy)benzene [RODA] (formula (3) below, melting point: 115.0 to 119.0° C.)

3,4'-diaminodiphenyl ether [3,4'-ODA] (the following formula (4), melting point: 67-71°C)

3,3'-methylenedianiline [3,3'-MDA] (the following formula (5), melting point: 82.0 to 85.0°C)

4,4'-methylenedianiline [4,4'-MDA] (the following formula (6), melting point: 91.0 to 94.0°C)

1,3-bis(3-aminophenoxy)benzene [TPE-M] (formula (7) below, melting point: 107.0 to 109.0° C.)

2,2-bis[4-(4-aminophenoxy)phenyl]propane [BAPP] (formula (8) below, melting point: 128.0 to 131.0° C.)

4,4'-diaminodiphenyl ether [4,4'-ODA] (the following formula (9), melting point: 190.0 to 194.0°C)

4,4'-bis(4-aminophenoxy)biphenyl [BAPB] (the following formula (10), melting point: 196.0 to 200.0°C)

4,4'-bis(3-aminophenoxy)biphenyl [3,3'-BAPB] (the following formula (11))

3,3'-diaminobenzophenone [3,3'-DABP], (the following formula (12), melting point: 149.0 to 156.0°C)

4,4'-diaminobenzophenone [4,4'-DABP], (the following formula (13), melting point: 245.0 to 249.0°C)

3,3'-sulfonyldianiline [3,3'-DDS] (the following formula (14), melting point: 170 to 173°C)

4,4'-sulfonyldianiline [4,4'-DDS] (the following formula (15), melting point: 175 to 177°C)

Bis[4-(4-aminophenoxy)phenyl]sulfone [BAPS] (the following formula (16))

Among the above-mentioned compounds, the melting point of the raw material is between 100 ° C. and 250 ° C., the stability and reactivity of the resulting benzoxazine compound, and the heat resistance and mechanical properties of the cured product obtained therefrom. From the point of view, the diamine is preferably 1,3-bis(4-aminophenoxy)benzene [RODA].

(monoamine)
In the present production method, when monoamines are used, examples include aniline, toluidines, xylidines, ethylanilines, ethynylanilines, chloroanilines, bromoanilines, nitroanilines, aminophenols, aminocresols, amino Benzyl alcohols, anisidines, phenetidines, aminobenzaldehydes, aminobenzonitriles, aminobiphenyls, aminophenylphenyl ethers, aminobenzophenones, aminophenylphenyl sulfides, aminophenylphenyl sulfones, naphthylamines, amino- Aromatic monoamines such as naphthols and aminoanthracenes can be used. There are no particular restrictions on the melting point and the like.

Among these, aniline or ethynylaniline is preferred from the viewpoint of handleability, stability and reactivity of the obtained benzoxazine-based compound, heat resistance and mechanical properties of the cured product obtained therefrom, and the like. When the monoamine is an ethynylaniline, it can be expected that thermal cross-linking of the ethynyl site will further improve the thermal properties of the cured product.

(others)
In this production method, (A) phenol is monophenol in which only one hydroxy group is bonded to the benzene ring.

Moreover, (C) paraformaldehyde can be represented by the following general formula (17).

<1-2. Purification process>
When the SC of the product is less than 100% by weight at the end of the reaction step, the production method may further include a purification step of washing the product. The purification step is performed to remove the solvent contained in the product.

In the purification step, the liquid for washing the product is not particularly limited, and may be, for example, water, an alkaline solution, and/or an acidic solution. The alkaline solution is not particularly limited, but may be, for example, an aqueous NaOH solution. Although the acidic solution is not particularly limited, it may be, for example, an HCl aqueous solution. Any solution may be used for washing, and the order of washing is not particularly limited. That is, for example, washing with an alkaline solution may be followed by washing with water, or washing with water may be followed by washing with an alkaline solution. Also, after washing with an alkaline solution, washing with an acidic solution may be performed. Among these, cleaning with an alkaline solution or cleaning with water is preferred, and a combination of cleaning with an alkaline solution and cleaning with water is more preferred.

The product obtained in the reaction step may be diluted with a solvent such as chloroform before performing the purification step. The solvent used for dilution can be removed by distillation under reduced pressure or the like after the purification step is completed.

<1-3. Others>
This production method comprises a mixture of (A1) a monophenol-based composition containing phenol, (B1) an amine-based composition containing a diamine and an optional monoamine, and (C) paraformaldehyde, or (A2) A reaction step of heating and reacting a mixture of a phenol-based composition containing bisphenol, (B2) a monoamine-based composition containing aniline, and (C) paraformaldehyde, wherein the SC of the mixture is 80 to 100 wt. %, it may be a method for producing a benzoxazine-based compound.

In the reaction step of this production method, SC is more preferably more than 80% by weight and less than 100% by weight, more preferably 85 to 99% by weight, most preferably 90 to 98% by weight.

<1-3-1>
A case of using a mixture of (A1), (B1) and (C) will be described below.

In the reaction step of the present production method, when SC is 100% by weight, (A1) the phenol-containing monophenolic composition preferably consists of phenol only. Further, when the SC is 80% by weight or more and less than 100% by weight, (A1) the monophenol composition containing phenol contains 51 to 100% by weight of phenol and 49 to 0% by weight of monophenol other than phenol. %, preferably 70 to 100% by weight of phenol and 30 to 0% by weight of monophenol other than phenol, more preferably 80 to 100% by weight of phenol and 20% by weight of monophenol other than phenol. 0% by weight, most preferably 90-100% by weight of phenol and 10-0% by weight of monophenols other than phenol.

Examples of the monophenols other than phenol include those having one or more phenolic hydroxyl groups in the aromatic ring, such as cresols, 3-methoxyphenols, 4-ethoxyphenols, fluorophenols, fluorocresol , ethynylphenols, cyanophenols, hydroxybenzaldehydes, dimethylphenols, ethylphenols, hydroxybenzyl alcohols, hydroxybenzenethiols, chlorophenols, allylphenols, naphthols, nitronaphthols, hydroxypyrene, etc. There are no particular restrictions on the melting point and the like. Among these, ethynylphenols are preferred from the viewpoint of handleability, stability and reactivity of the obtained benzoxazine-based compound, and heat resistance and mechanical properties of the cured product obtained therefrom. When the monophenol is ethynylphenol, thermal cross-linking of the ethynyl moiety is expected to further improve the thermal properties of the cured product.

The conditions for using (A1) a monophenol-based composition containing phenol and (B1) an amine-based composition containing a diamine and a monoamine as an optional component, SC in the reaction step, and heating conditions are described in [ 1. Method for producing benzoxazine-based compound].

<1-3-2>
A case where a mixture of (A2), (B2) and (C) is used is described below.

In the present production method, when only bisphenol is used as (A2) the phenolic composition containing bisphenol, the molar ratio of bisphenol:aniline and monoamine:paraformaldehyde should be 1:2:4 to 1:2:6. is preferred. Here, when (A2) the phenol-based composition containing bisphenol contains monophenol, 2 mol of monophenol is converted to 1 mol of bisphenol, and the molar ratio is calculated after summing the number of moles with bisphenol. do it.

(monophenol)
(A2) The phenolic composition containing bisphenol contains 30 to 100% by weight of bisphenol and 70 to 0% by weight of monophenol, preferably 50 to 100% by weight of bisphenol and 50 to 0% by weight of monophenol. %, more preferably 70 to 100% by weight of bisphenol and 30 to 0% by weight of monophenol.

In the present production method, when using bisphenol, for example, 2,2-bis(4-hydroxyphenyl)propane (common name: bisphenol A), bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxy phenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 2,2-bis(4-hydroxy-1-methylphenyl)propane, 1,1 -bis(4-hydroxy-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl ) Bis(hydroxyaryl)alkanes such as propane; Bis(hydroxyaryl)arylalkanes such as 2,2-bis(4-hydroxyphenyl)phenylmethane and bis(4-hydroxyphenyl)naphthylmethane; 1,1- Bis(hydroxyaryl) such as bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,5,5-trimethylcyclohexane, etc. Cycloalkanes; Dihydroxyaryl ethers such as 4,4'-dihydroxyphenyl ether, 4,4'-dihydroxy-3,3'-dimethylphenyl ether; 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy -dihydroxydiarylsulfoxides such as 3,3'-dimethyldiphenylsulfide; dihydroxydiarylsulfoxides such as 4,4'-dihydroxydiphenylsulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide;4,4 Dihydroxydiarylsulfones such as '-dihydroxydiphenylsulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone; dihydroxydiphenyls such as 4,4'-dihydroxydiphenyl; Among these, from the viewpoint of handling ease due to the melting point of the raw material being between 100°C and 250°C, the stability and reactivity of the resulting benzoxazine-based compound, and the heat resistance and mechanical properties of the cured product obtained therefrom, Bisphenol A is preferred.

The monophenols mentioned above have one or more phenolic hydroxyl groups in the aromatic ring, and examples thereof include phenol, cresols, 3-methoxyphenols, 4-ethoxyphenols, fluorophenols, and fluorocresols. , ethynylphenols, cyanophenols, hydroxybenzaldehydes, dimethylphenols, ethylphenols, hydroxybenzyl alcohols, hydroxybenzenethiols, chlorophenols, allylphenols, naphthols, nitronaphthols, hydroxypyrene, etc. There are no particular restrictions on the melting point and the like. Among these, phenol or ethynylphenols are preferred from the viewpoint of handleability, stability and reactivity of the obtained benzoxazine-based compound, and heat resistance and mechanical properties of the cured product obtained therefrom. In the case of ethynylphenol, thermal cross-linking of the ethynyl moiety can be expected to further improve the thermal properties of the cured product.

(B2) The monoamine-based composition containing aniline contains 51 to 100% by weight of aniline and 49 to 0% by weight of monoamine other than aniline, preferably 70 to 100% by weight of aniline and monoamine other than aniline. 30 to 0% by weight, more preferably 80 to 100% by weight of aniline and 20 to 0% by weight of monoamines other than aniline, and most preferably 90 to 100% by weight of aniline and other than aniline. It contains 10 to 0% by weight of monoamine.

Examples of the above monoamines other than aniline include toluidines, xylidines, ethylanilines, ethynylanilines, chloroanilines, bromoanilines, nitroanilines, aminophenols, aminocresols, aminobenzyl alcohols, Anisidines, phenetidines, aminobenzaldehydes, aminobenzonitriles, aminobiphenyls, aminophenylphenyl ethers, aminobenzophenones, aminophenylphenylsulfides, aminophenylphenylsulfones, naphthylamines, amino-naphthols, amino Examples include aromatic monoamines such as anthracenes, and there are no particular restrictions on the melting point. Among these, ethynylanilines are preferred from the viewpoint of handleability, stability and reactivity of the obtained benzoxazine-based compound, heat resistance and mechanical properties of the cured product obtained therefrom, and the like. When the monoamine is an ethynylaniline, it can be expected that thermal cross-linking of the ethynyl site will further improve the thermal properties of the cured product.

[2. Benzoxazine compound]
The benzoxazine-based compound produced by this production method (hereinafter also referred to as the present benzoxazine-based compound) is a compound represented by the following formula (17).

In formula (17) above, R1 is determined by the diamine used as a raw material. That is, it can be said that R1 is represented by the above formula (2). For example, when 1,3-bis(4-aminophenoxy)benzene represented by formula (3) is used as the diamine, a benzoxazine compound represented by the following general formula (18) is obtained.

The glass transition temperature (Tg) of the present benzoxazine compound is preferably 110° C. or higher, more preferably 120° C. or higher, and even more preferably 130° C. or higher. If the Tg of the present benzoxazine-based compound is 110° C. or higher, it can be said that the present benzoxazine-based compound has excellent heat resistance. Although the upper limit of Tg is not particularly limited, it may be 300° C. or lower in reality. As used herein, "glass transition temperature (Tg)" means the temperature at which a cured product obtained by curing the present benzoxazine compound by heating undergoes a glass transition.

The curing temperature (Tc) of the present benzoxazine-based compound is preferably 270° C. or lower, more preferably 260° C. or lower, and even more preferably 250° C. or lower. If the Tc of the present benzoxazine-based compound is 270° C. or less, it becomes easy to produce a cured product from the present benzoxazine-based compound. As used herein, "curing temperature (Tc)" means the temperature at which the present uncured benzoxazine compound is cured by heating.

The 5% weight loss temperature (Td5) of the present benzoxazine compound is preferably 290°C or higher, more preferably 300°C or higher, and even more preferably 310°C or higher. If the present benzoxazine-based compound has a temperature of 290° C. or higher, it can be said that the present benzoxazine-based compound has excellent heat resistance. In this specification, the "5% weight loss temperature (Td5)" is the point at which the weight of the uncured benzoxazine compound is reduced by 5% due to thermal decomposition, which is measured in an environment where the uncured benzoxazine compound is cured. means the temperature at

The present benzoxazine compounds are suitable for electronic parts, printed wiring board laminates and printed wiring boards, semiconductor encapsulation materials, electronic materials such as semiconductor-mounted modules, automobiles or vehicles, aircraft parts, building materials, machine tools, etc. can be used. Among these, in particular, it can be used for parts that require heat resistance.

Specifically, for example, when used as a molding material for the above parts or a semiconductor encapsulating material, the present benzoxazine-based compound can be used as is, or if necessary, a filler, release agent, flame retardant, coloring agent, coupling agent, or the like. It can be used by adding an agent or the like. Also, a varnish is prepared by adding a solvent or the like to the present benzoxazine-based compound, impregnating a base material such as a glass cloth with the varnish, and heating and drying the varnish to prepare a prepreg for a laminated board. Furthermore, a printed wiring board can be produced by heating and pressing this prepreg together with a metal foil to produce a laminate for a printed wiring board, and further forming a circuit on the laminate. The printed wiring board produced in this manner is excellent in heat resistance, mechanical properties, etc., and is therefore suitable for use as a semiconductor mounting substrate or the like.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

Examples and comparative examples are given below to illustrate the present invention, but are not intended to limit the present invention. First, the method for measuring each physical property was as follows.

〔Measuring method〕
(1. Glass transition temperature (Tg))
Differential scanning calorimetry (DSC) of the powdery uncured product was measured using a differential thermal scanning calorimeter DSC7000X (manufactured by Hitachi High-Tech). Specifically, the DSC curve was measured under the conditions of a nitrogen stream (40 mL/min) and a heating rate of 10° C./min. The temperature at the intersection of the tangent line at the inflection point of the obtained DSC curve and the baseline was defined as Tg. In addition, as Tg, the numerical value of the 2nd scan of DSC was employ|adopted.

(2. Curing temperature (Tc))
Tc was calculated in the same manner as Tg, except that the value of the 1st scan was used as DSC.

(3. Thermal decomposition temperature (Td5))
For the powder-shaped uncured material, by the thermogravimetric analysis (TGA) method using Hitachi High-Tech's product name "TG/DTA6300", the temperature of 5% weight loss (Td5) is measured at a temperature increase rate of 10 ° C./min. evaluated. As Td5, the value of differential thermal analysis (TG-DTA) measured under N ₂ stream was used.

[Example 1]
2.193 g (0.0075 mol) of 1,3-bis(4-aminophenoxy)benzene, 1.412 g (0.015 mol) of phenol, and 1.081 g (0.036 mol) of paraformaldehyde were charged into a three-necked flask and heated to 130°C. The mixture was heated and stirred at , and reacted for 30 minutes. The heating time is determined based on the time when the consumption rate of phenol as a raw material is about 93%, calculated by 1H-NMR. Since no solvent was used, the solid content concentration (SC) was set to 100% by weight.

After the heat reaction, 80 ml of chloroform was added to dissolve the product. Then, after washing three times with 80 ml of 1N NaOH aqueous solution and three times with 80 ml of pure water, the solvent in the chloroform layer was distilled off under reduced pressure at 40°C. Then, it was vacuum-dried at 60° C. for 6 hours to obtain a powder of the benzoxazine-based compound of the above formula (18).

The obtained benzoxazine-based compound powder was measured for molecular weight by GPC.

[Example 2]
1,3-bis(4-aminophenoxy)benzene 2.193 g (0.0075 mol), phenol 1.412 g (0.015 mol), paraformaldehyde 1.081 g (0.036 mol), N-methylpyrrolidone 0.247 g The mixture was put into a three-necked flask, heated with stirring at 130° C., and reacted for 60 minutes. The heating time was determined in the same manner as in Example 1. The solid content concentration (SC) was calculated based on the assumption that all of the above diamine, phenol, and aldehyde were solidified. SC=95% by weight.

After the reaction, 30 ml of chloroform was added to dilute the product, and the product was washed 5 times with 30 ml of pure water. Then, after washing three times with 30 ml of 1N NaOH aqueous solution and three times with 30 ml of pure water, the solvent in the chloroform layer was distilled off under reduced pressure at 40°C. Then, it was vacuum-dried at 60° C. for 6 hours to obtain a powder of the benzoxazine-based compound of the above formula (18).

The obtained benzoxazine-based compound powder was measured for molecular weight by GPC.

[Example 3]
1,3-bis(4-aminophenoxy)benzene 2.193 g (0.0075 mol), phenol 1.412 g (0.015 mol), paraformaldehyde 1.081 g (0.036 mol), N-methylpyrrolidone 1.172 g The mixture was put into a three-necked flask, heated with stirring at 130° C., and reacted for 120 minutes. The heating time was determined in the same manner as in Example 1. The solid content concentration (SC) was calculated in the same manner as in Example 2. SC=80% by weight.

After the reaction, 30 ml of chloroform was added to dilute the product, and the product was washed 5 times with 30 ml of pure water. After that, it was washed three times with 100 ml of 1N NaOH aqueous solution and three times with 100 ml of pure water. Subsequently, after washing with 100 ml of 0.1N HCl aqueous solution three times, washing with 100 ml of pure water three times was performed, and the solvent in the chloroform layer was distilled off under reduced pressure at 40°C. Then, it was vacuum-dried at 60° C. for 6 hours to obtain a powder of the benzoxazine-based compound of the above formula (18).

The obtained benzoxazine-based compound powder was measured for molecular weight by GPC.

[Comparative Example 1]
1,3-bis(4-aminophenoxy)benzene 2.195 g (0.0075 mol), phenol 1.413 g (0.015 mol), 37% formalin 2.925 g (0.036 mol), ethyl acetate 1.285 g in three mouths It was put into a flask, heated with stirring at 80° C., and reacted for 25 hours. The heating time was determined in the same manner as in Example 1. The solid content concentration (SC) was calculated in the same manner as in Example 2. SC=60% by weight.

After the reaction, 80 ml of chloroform was added to dilute the product, and after washing three times with 80 ml of 1N NaOH aqueous solution and three times with 40 ml of pure water, the chloroform layer was distilled off under reduced pressure at 40°C. Then, it was vacuum-dried at 60° C. for 6 hours to obtain a powder of the benzoxazine-based compound of the above formula (18).

The obtained benzoxazine-based compound powder was measured for molecular weight by GPC.

〔result〕
Table 1 shows the heating conditions during the reaction in Examples 1 to 3 and Comparative Example 1, and the results of evaluating the thermal properties of the obtained benzoxazine-based compound powder of formula (18) by DSC and TGA. show.

From Table 1, it was found that the heating times of Examples 1 to 3 with SC of 80 to 100% by weight were much shorter than the heating time of Comparative Example 1 with SC of 60% by weight. It was also found that the benzoxazines of Examples 1-3 have comparable performances in terms of Tg, Tc and Td5 compared to the benzoxazine of Comparative Example 1 obtained by the conventional solution method. Therefore, it was shown that the present production method can produce a benzoxazine-based compound in a shorter time than the conventional production method.

INDUSTRIAL APPLICABILITY The present invention can be suitably used as a method for producing a benzoxazine-based compound.

Claims (9)

A reaction step of heating and reacting a mixture of (A) phenol, (B) an amine-based composition containing a diamine represented by the following general formula (1) and a monoamine as an optional component, and (C) paraformaldehyde. A method for producing a benzoxazine-based compound, wherein the mixture has a solid content concentration of 80 to 100% by weight.

In formula (1), R1 is represented by the following general formula (2).

In formula (2), L1 and L3 are O (ether bond), L2 is O (ether bond), C═O, SO ₂ , C(CH ₃ ) ₂ , C(CF ₃ ) ₂ , or CH ₂ and p, q, r, s, and t are 0 or 1. However, p+q+r+s+t≧1, p or q is 0 when s=0, and q or r is 0 when t=0. The method for producing a benzoxazine-based compound according to claim 1, wherein the heating temperature is 90°C or higher in the reaction step. 3. The method for producing a benzoxazine-based compound according to claim 1, wherein the heating time in the reaction step is 5 hours or less. Production of the benzoxazine-based compound according to any one of claims 1 to 3, wherein the mixture contains (D) a solvent having a boiling point of 100°C or higher in an amount of more than 0% by weight and less than 20% by weight. Method. The solvent (D) is N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), 1,4-dioxane, toluene, n-butyl acetate. , and diethyl carbonate, the method for producing a benzoxazine-based compound according to claim 4. 6. The benzo according to any one of claims 1 to 5, further comprising a purification step of washing the product when the solid content of the product is less than 100% by weight at the time the reaction step is completed. A method for producing an oxazine-based compound. The method for producing a benzoxazine compound according to any one of claims 1 to 6, wherein the diamine has a melting point of 60°C or higher. The method for producing a benzoxazine-based compound according to any one of claims 1 to 7, wherein the diamine is one or more selected from compounds represented by the following formulas (3) to (16).

A mixture of (A1) a monophenolic composition containing phenol, (B1) an amine composition containing a diamine and optionally a monoamine, and (C) paraformaldehyde, or (A2) a bisphenol A reaction step of heating and reacting a mixture of a phenol-based composition, (B2) a monoamine-based composition containing aniline, and (C) paraformaldehyde, wherein the solid content concentration of the mixture is 80 to 100% by weight. A method for producing a benzoxazine-based compound.