Reaction product containing benzoxazine, and cured product thereof

Abstract

The present invention lessens reduction in mass during thermal curing of a reaction product obtained through a condensation reaction of a phenol, a diamine, and formaldehyde.　A reaction product according to an embodiment of the present invention comprises a first product represented by formula (1) and a second product represented by formula (2). With respect to 100% of the total peak area of the reaction product determined through HPLC, the peak area of the second product is 5-15%, and the total of the peak areas of the first product and the second product is 65-75%. In the formula , R1 represents -CH2-, -CH(CH3)-, -C(CH3)2-, or -O-, R2 and R3 each represent a methyl group or an ethyl group, R4 and R5 each represent an alkyl group or an alkenyl group, and p and q each represent an integer of 0-4.

Description

Reaction products containing benzoxazine, and their cured products

[0001] Embodiments of the present invention relate to reaction products containing benzoxazine and cured products thereof.

[0002] Benzoxazines are compounds containing a benzoxazine ring formed by the condensation reaction of phenols, amines, and formaldehyde. Benzoxazines are thermosetting monomers that harden upon heating through ring-opening polymerization of the benzoxazine ring, and the hardened product forms intramolecular and intermolecular hydrogen bonds.

[0003] For example, Patent Document 1 discloses a benzoxazine compound having two benzoxazine rings in one molecule, obtained by condensing phenol with 4,4'-diaminodiphenylmethane and paraformaldehyde. Patent Document 2 discloses a benzoxazine compound having benzoxazine rings at the 3 and 4' positions of a diphenyl ether group, obtained by condensing phenol with 3,4'-diaminodiphenyl ether and formaldehyde.

[0004] Japanese Patent Publication No. 4647398, Japanese Unexamined Patent Publication No. 2018-184533

[0005] The reaction products obtained by the condensation reaction of phenols, diamines, and formaldehyde may include, as the main product, benzoxazine having two benzoxazine rings, as well as by-products such as polymers of the benzoxazine, products resulting from incomplete reactions such as mono-ring products where one benzoxazine ring is not closed, and unreacted starting materials.

[0006] Incidentally, during thermal ring-opening polymerization of benzoxazine, the imine is detached from the zwitterionic intermediate and released as a gas, resulting in a decrease in mass and the formation of voids in the cured product. Therefore, it is necessary to reduce the mass loss during thermal curing.

[0007] The embodiments of the present invention aim to reduce the mass loss during thermal curing of reaction products obtained by condensation reactions of phenols, diamines, and formaldehyde.

[0008] In the process of earnestly studying to reduce the mass loss during thermosetting of the reaction product obtained by subjecting phenols, diamines and formaldehyde to a condensation reaction, the inventors have found that by containing a first product which is the main product represented by the following formula (1) and a second product which is a ring-opened product represented by the following formula (2) in a specific ratio, the mass loss during thermosetting can be reduced, and thus the present invention has been completed.

[0009] The present invention includes the following embodiments. [1] A reaction product obtained by subjecting phenols, diamines and formaldehyde to a condensation reaction, comprising a first product represented by the following formula (1) and a second product represented by the following formula (2), In the formulas (1) and (2), R １ represents -CH ２ -, -CH(CH ３ )-, -C(CH ３ ) ２ -, or -O-, R ２ and R ３ each independently represent a methyl group or an ethyl group, R ４ and R ５ each independently represent an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, p and q each independently represent an integer of 0 to 4, based on 100% of the total peak area of the reaction product by HPLC, provided that when the reaction product contains a solvent, based on 100% of the total peak area excluding the solvent, the peak area of the second product is 5 to 15%, and the total peak area of the first product and the second product is 65 to 75%, the reaction product.

[0010] [2] In the formulas (1) and (2), R １ represents -CH ２ - or -O-, p and q each independently represent an integer of 0 to 2, the reaction product according to [1].

[0011] [3] The first product is represented by the following formula (3), and the second product is represented by the following formula (4), In the formulas (3) and (4), R ４ and R５ The reaction product according to [1] or [2], each independently representing an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms.

[0012] [4] A cured product obtained by curing the reaction product according to any one of [1] to [3].

[0013] According to an embodiment of the present invention, in a reaction product obtained by subjecting phenols, diamines, and formaldehyde to a condensation reaction, the mass loss during thermosetting can be reduced.

[0014] UV chromatogram of the reaction product obtained in Example 1 UV chromatogram of toluene Mass chromatogram of the reaction product obtained in Example 1 Mass chromatogram of the component (first product) having a molecular weight of 515 among the reaction products obtained in Example 1 Mass chromatogram of the component (second product) having a molecular weight of 503 among the reaction products obtained in Example 1 Chromatogram of the reaction product obtained in Example 1

[0015] The reaction product according to the present embodiment is obtained by a condensation reaction of phenols, diamines, and formaldehyde, and includes a first product represented by the following formula (1) and a second product represented by the following formula (2).

[0016] In formula (1) and formula (2), R １ represents -CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, or -O -, preferably -CH ２ - or -O -, more preferably -CH ２ -. In one embodiment, the bonding position of R １ to the two benzene rings is preferably the 4,4'-position, 3,4'-position, or 3,3'-position as the bonding position of the benzoxazine ring or NH to the group represented by Ph-R １ -Ph (where Ph represents a benzene ring which may have a substituent R ２ or R ３ ).)

[0017] In Formula (1) and Formula (2), R ２ and R ３ each independently represents a methyl group or an ethyl group, more preferably a methyl group. When there are a plurality of R ２ and R ３ in one molecule, they may be the same or different. p and q each independently represent an integer from 0 to 4, more preferably an integer from 0 to 2, and even more preferably 0.

[0018] In Formula (1) and Formula (2), R ４ and R ５ each independently represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, more preferably represents an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 or 3 carbon atoms. These alkyl groups and alkenyl groups may be linear or branched. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 2-methylallyl group, a 1-methylallyl group, and a 2-methyl-1-propenyl group.

[0019] When R ４ and R ５ are alkenyl groups, they do not react by the thermal ring-opening polymerization of benzoxazine, but can be used for copolymerization with other polymerizable monomers.

[0020] The first product represented by Formula (1) is the main product as the target product, which is composed of one molecule of diamine, two molecules of phenols, and four molecules of formaldehyde, and has two benzoxazine rings in one molecule. The second product represented by Formula (2) is a ring-opened product in which one of the two benzoxazine rings of the first product is not ring-closed but ring-opened.

[0021] The first product is preferably a compound represented by the following Formula (3), and the second product is preferably a compound represented by the following Formula (4).

[0022] In equations (3) and (4), R ４ and R ５ R is in equations (1) and (2). ４ and R ５ It is the same as this.

[0023] In the reaction product according to this embodiment, the content of the first product and the second product is as follows: The peak area of ​​the second product is 5 to 15% of the total peak area of ​​the reaction product by HPLC (however, if the reaction product contains a solvent, the total peak area excluding the solvent is 100%), and the sum of the peak areas of the first and second products is 65 to 75%. By including the target product, the first product, and the second product, which is a one-ring opened product, in such proportions, the mass loss during thermal curing of the reaction product can be reduced, and the glass transition temperature Tg of the cured product can be increased. The reason for this is not intended to be limited thereto, but is presumed to be as follows: Since the one-ring opened product has a phenolic hydroxyl group, it undergoes thermal ring-opening polymerization during thermal curing and also functions as a catalyst, which is thought to improve the reactivity of thermal ring-opening polymerization. It is believed that the presence of the ring-opening compound and the target product (first product) in the above amounts moderately promotes the thermal ring-opening polymerization reaction, thereby improving the glass transition temperature during curing and suppressing the mass loss due to imine detachment.

[0024] More specifically, by having a combined peak area of ​​65% or more and 75% or less for the first and second products, the mass loss of the reaction products during thermal curing can be reduced. The combined peak area of ​​the first and second products is more preferably 66-73%, more preferably 67-72%, and even more preferably 68-71%.

[0025] Furthermore, by having a peak area of ​​5% to 15% of the second product, the mass loss of the reaction product during thermal curing can be reduced, and the decrease in the glass transition temperature of the cured product can be suppressed. The peak area of ​​the second product is more preferably 6 to 13%, more preferably 7 to 12%, and even more preferably 8 to 11%.

[0026] The peak area of ​​the first product is not particularly limited, but is preferably 50-70%, more preferably 52-67%, more preferably 54-66%, and even more preferably 56-65%.

[0027] The peak area of ​​the second product, the sum of the peak areas of the first and second products, and the peak area of ​​the first product, relative to 100% of the total peak area of ​​the reaction products obtained by HPLC, are determined by performing HPLC (high-performance liquid chromatography) on the reaction products. For the chromatogram obtained by HPLC, the sum of the peak areas of all peaks (except, if the reaction product contains a solvent, the peak areas of all peaks excluding those originating from the solvent) is taken as 100%, and the peak area ratio of each peak is calculated. This allows for the determination of the peak area ratio of the peaks originating from the first product and the peak area ratio of the peaks originating from the second product. The sum of the peak areas of the first and second products is obtained by calculating the sum of these ratios. Details regarding the HPLC measurement conditions are described in detail in the Examples section.

[0028] The reaction product according to this embodiment is obtained by condensing phenols, diamines, and formaldehyde, and is a mixture (and therefore also called the reaction product composition) containing a first product and a second product, both of which are benzoxazines. In addition to the first product, which is the main product, and the second product, which is a by-product, the reaction product may also contain polymers (including oligomers) of the benzoxazine, other by-products, unreacted raw materials, and a solvent. Examples of other by-products include compounds obtained by dehydration condensation of one molecule of diamine and three or four molecules of phenols via formaldehyde, and compounds obtained by dehydration condensation of two molecules of diamine and three molecules of phenols via formaldehyde. These may have one or more benzoxazine rings, and some of the benzoxazine rings may be open rather than closed.

[0029] If the reaction product contains a solvent, examples of solvents include organic solvents capable of dissolving benzoxazine, such as toluene, xylene, cumene, monochlorobenzene, methyl ethyl ketone, ethyl acetate, butyl acetate, chloroform, dichloromethane, THF, dioxane, and dimethylformaldehyde. These may be used individually or in combination of two or more. In this case, the concentration of the reaction product solution is not particularly limited and may be, for example, 30 to 65% by mass or 40 to 60% by mass.

[0030] The reaction product according to this embodiment may be a reaction product obtained by condensing phenols, diamines, and formaldehyde, or it may be obtained by liquid-liquid washing, recrystallization, column purification, etc.

[0031] The method for producing the above reaction product is not particularly limited. For example, one method involves stirring and mixing phenols, diamines, and formaldehyde in the presence of a solvent, and then carrying out a dehydration condensation reaction under heating. Preferably, this method involves adding formaldehyde to a mixed solution obtained by dissolving phenols and diamines in a solvent such as toluene, carrying out a dehydration condensation reaction under heating, and then further increasing the temperature and aging at a high temperature.

[0032] Examples of phenols include compounds represented by formula (5) below, examples of diamines include compounds represented by formula (6) below, and examples of formaldehyde include paraformaldehyde, i.e., (HClO) ｎ These are some examples.

[0033] In equation (5), R ６ R in the above formula (1) is ４ and R ５ This is equivalent to, that is, it represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, and more preferably, an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 or 3 carbon atoms.

[0034] In equation (6), R １ , R ２ , R ３ p and q are R in formula (1) above, respectively. １, R ２ , R ３ , is the same as p and q, that is, R １ is, -CH ２ -, -CH(CH ３ )-,-C(CH ３ ) ２ - or -O- represents R ２ and R ３ Each of these independently represents either a methyl group or an ethyl group, and each of p and q independently represents an integer from 0 to 4.

[0035] Specific examples of the diamine in formula (6) include 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-diamino-2,2',4,4'-tetramethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraethyldiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyl-5,5'-diethyldiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, etc. One or more of these may be used.

[0036] Specific examples of phenols in formula (5) include 2-methylphenol, 2-ethylphenol, 2-propylphenol, 2-isopropylphenol, 2-tert-butylphenol, 2-vinylphenol, 2-propenylphenol, 2-allylphenol, 2-isopropenylphenol, 2-(3-butenyl)phenol, and 2-(2-methyl-2-propenyl)phenol. Any one or more of these may be used.

[0037] Regarding the ratio of phenols, diamines, and formaldehyde, since the target product represented by formula (1) is obtained by reacting 2 moles of phenols and 4 moles of formaldehyde with 1 mole of diamine, the amount of charge can be set based on this. For example, it is preferable to charge 2.0 to 2.5 moles of phenols per mole of diamine, more preferably 2.0 to 2.2 moles, and even more preferably 2.0 to 2.1 moles. It is preferable to charge 3.9 to 5.0 moles of formaldehyde per mole of diamine, more preferably 4.0 to 4.5 moles, and even more preferably 4.0 to 4.3 moles. Reducing the amount of formaldehyde tends to increase the content of the secondary product, while increasing the amount of formaldehyde tends to increase the content of the primary product and decrease the content of the secondary product.

[0038] The temperature during the dehydration condensation reaction is not particularly limited; for example, it may be 70-90°C or 75-85°C. The temperature during aging is not particularly limited; for example, it may be 95-130°C, 100-120°C or 105-115°C. The aging time is not particularly limited; for example, it may be 1-20 hours, 3-15 hours or 5-12 hours. Increasing the aging time tends to reduce the content of the secondary product.

[0039] The concentration of the reactants when carrying out a dehydration condensation reaction in the presence of a solvent is not particularly limited; for example, it may be 30-65% by mass or 40-60% by mass. Increasing the concentration tends to reduce the amount of the first product, and also tends to reduce the total amount of the first and second products.

[0040] The reaction product according to this embodiment contains benzoxazine, and is a thermosetting resin that hardens (thermally cured) by thermal ring-opening polymerization of the benzoxazine as a monomer. The cured product according to this embodiment is obtained by curing the reaction product, and may be used alone or in combination with other resins. In other words, the reaction product according to one embodiment can constitute a thermosetting composition either alone or in combination with other resins.

[0041] The thermosetting composition contains the above-mentioned reaction product, and may also contain a thermosetting resin and / or a thermoplastic resin together with the reaction product. The thermosetting composition may also contain various known additives such as crosslinking agents, curing accelerators, and colorants.

[0042] The present invention will be described in more detail below based on examples and comparative examples, but it is not limited thereto.

[0043] <Measurement and Evaluation Method> The content of the first and second products in the reaction product can be determined by assigning the peaks derived from the first and second products to the chromatogram obtained by HPLC, and then determining the peak area ratio of each peak based on the result. In this example, the measurement was performed as follows.

[0044] [Assignment of HPLC Peaks] The reaction product obtained in Example 1 or toluene was dissolved in acetonitrile to a concentration of approximately 0.2 mg / ml, and measured using a high-performance liquid chromatograph (HPLC) (Agilent 1200 series, Agilent Technologies) equipped with a reversed-phase column (Inertsil ODS-3, 2.1 × 150 mm, particle size 3 μm, manufactured by GL Sciences Co., Ltd.). The measurement conditions were a column oven temperature of 40°C and a flow rate of 0.3 ml / min. A diode array (DAD) detector (G1315B, manufactured by Agilent Technologies, detection wavelength 254 nm) and an atmospheric pressure ionization time-of-flight mass spectrometer (JMS-T100LP, manufactured by JEOL Ltd.) were used as detectors. The needle voltage of the atmospheric pressure ionization time-of-flight mass spectrometer was set to 2500V, the detector voltage to 2000V, the peak voltage to 2100V, and the orifice 1 voltage to 50V.

[0045] Figure 1 shows the UV chromatogram of the reaction product obtained in Example 1 as detected by a DAD detector, and Figure 2 shows the UV chromatogram of toluene. Figure 3 shows the mass chromatogram of the reaction product obtained in Example 1 as detected by a mass spectrometer, Figure 4 shows the mass chromatogram of the component with a molecular weight of 515, and Figure 5 shows the mass chromatogram of the component with a molecular weight of 503.

[0046] From Figures 1 and 2, the peak at elution time 1.72 minutes in Figure 1 was assigned to toluene. Next, from Figures 3 to 5, the peak at elution time 2.91 minutes in Figure 3 was assigned to the first product, and the peak at elution time 2.39 minutes was assigned to the second product. Furthermore, since the peaks in Figures 1 and 3 are similar in shape, the peak at elution time 2.53 minutes in Figure 1 was assigned to the first product, and the peak at elution time 2.17 minutes was assigned to the second product.

[0047] Next, the reaction product obtained in Example 1 was dissolved in acetonitrile to a concentration of approximately 0.2 mg / ml, and measured using an integrated liquid chromatograph (model name: LC-2050C, detector type: UV, manufactured by Shimadzu Corporation, detection wavelength 254 nm) equipped with a reversed-phase column (Inertsil ODS-3, 4.6 × 150 mm, particle size 5 μm, manufactured by GL Sciences Co., Ltd.). The measurement conditions were a column oven temperature of 40°C and a flow rate of 1.44 ml / min. The obtained chromatogram is shown in Figure 6. Since the chromatogram in Figure 6 is similar in shape to the chromatogram in Figure 1, it was determined that in the chromatogram in Figure 6, the peak at elution time of 1.55 minutes was toluene, the peak at elution time of 2.26 minutes was the first product, and the peak at elution time of 1.93 minutes was the second product.

[0048] [Calculation of the sum of the peak areas of the first and second products and the peak area of ​​the second product] The reaction products obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were dissolved in acetonitrile to a concentration of approximately 0.2 mg / ml, and HPLC measurements were performed using an integrated liquid chromatograph (model name: LC-2050C, detector type: UV, manufactured by Shimadzu Corporation, detection wavelength 254 nm) equipped with a reversed-phase column (Inertsil ODS-3, 4.6 × 150 mm, particle size 5 μm, manufactured by GL Sciences Co., Ltd.). The measurement conditions were a column oven temperature of 40°C and a flow rate of 1.44 ml / min.

[0049] For the obtained chromatogram, the area ratio of each peak was calculated so that the sum of the peak areas of all peaks except those derived from toluene equaled 100%. The peak area ratio (%) of the peak derived from the first product and the peak area ratio (%) of the peak derived from the second product were determined, and the sum of these ratios was calculated to find the total peak area (%) of the first and second products.

[0050] [Mass Loss Rate] Approximately 2 g of the reaction products obtained in Examples 1-5 and Comparative Examples 1-4 were placed in aluminum cups with an upper diameter of 60 mm, a lower diameter of 54 mm, and a depth of 16 mm, and the solvent was removed by distillation after heating at 120°C for 30 minutes. Then, using a differential thermobalance (Rigaku Corporation, Thermo Plus EVO TG8120), the temperature was raised from room temperature to 250°C at a heating rate of 10°C / min, and the mass loss rate was measured after holding at 250°C for 1 hour.

[0051] [Glass Transition Temperature (Tg)] 7.5 g of the reaction products obtained in Examples 1-5 and Comparative Examples 1-4 were placed in aluminum cups with an upper diameter of 60 mm, a lower diameter of 54 mm, and a depth of 16 mm, and heated on a hot plate at 120°C for 1 hour to remove the solvent by distillation. Furthermore, the hot plate was heated to 250°C for 1 hour to perform thermal curing, and a flat plate was prepared by allowing it to cool at room temperature. A test piece with a width of 5 mm, a thickness of 1 mm, and a length of 30 mm was prepared from the obtained flat plate. Next, the glass transition temperature was measured using a dynamic viscoelasticity measuring device: Rheogel-E4000 (manufactured by UBM Co., Ltd.). For the test piece, the maximum value of the loss tangent (tanδ) measured under the conditions of a tensile sine wave, dynamic strain of 5 μm, frequency of 1 Hz, and heating rate of 3°C / min was determined as the glass transition temperature.

[0052] <Example 1> In a 5 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 521.0 g of 4,4'-diaminodiphenylmethane, 705.2 g of 2-allylphenol, and 1569.3 g of toluene were added and dissolved at 75°C. Next, 343.1 g of 92% by mass paraformaldehyde was added in five portions, and the reaction mixture was heated to remove the water produced by the dehydration condensation reaction. The reaction mixture was further heated to 105-110°C and the reaction was continued for 6 hours. After the reaction mixture was cooled to room temperature, 301.7 g of toluene was added to dilute it. 784.6 g of 10% by mass sodium hydroxide aqueous solution was added and stirred for 15 minutes, then allowed to stand to separate and remove the aqueous layer. This procedure was repeated twice. Furthermore, 627.7 g of water and 156.9 g of isopropyl alcohol were added to the obtained organic layer and stirred for 15 minutes, then allowed to stand to separate and remove the aqueous layer. This procedure was repeated five times. The water and isopropyl alcohol in the obtained organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the first product, represented by formula (7) below, was 61.2%, the peak area of ​​the second product, represented by formula (8) below, was 8.2%, and the total peak area of ​​the first and second products was 69.4%.

[0053] <Example 2> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 81.6 g of 4,4'-diaminodiphenylmethane, 110.4 g of 2-allylphenol, and 245.8 g of toluene were added and dissolved at 75°C. Next, 53.8 g of 91% by mass paraformaldehyde was added in five portions, and the reaction mixture was heated to remove the water produced by the dehydration condensation reaction. The reaction mixture was further heated to 105-110°C and the reaction was continued for 6 hours. After the reaction mixture was cooled to room temperature, 69.5 g of toluene was added to dilute it. 98.3 g of 10% by mass aqueous sodium hydroxide solution and 24.6 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. After standing, the aqueous layer was separated and removed twice, and then 31.5 g of toluene was added to the resulting organic layer to dilute it. 98.3 g of water and 24.6 g of isopropyl alcohol were added to the mixture, stirred for 15 minutes, and allowed to stand. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol in the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the second product was 14.6%, and the combined peak area of ​​the first and second products was 67.6%.

[0054] <Example 3> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 81.6 g of 4,4'-diaminodiphenylmethane, 110.4 g of 2-allylphenol, and 245.8 g of toluene were added and dissolved at 75°C. Next, 60.4 g of 92% by mass paraformaldehyde was added in five portions, and the reaction solution was heated to remove the water produced by the dehydration condensation reaction. The reaction solution was further heated to 105-110°C and the reaction was continued for 6 hours, after which the reaction solution was cooled to room temperature (hereinafter this reaction solution will be referred to as "reaction solution A"). 200 g of reaction solution A was taken and diluted with 22.4 g of toluene. 42.8 g of 10% by mass sodium hydroxide aqueous solution and 10.7 g of isopropyl alcohol were added and stirred for 15 minutes, then allowed to stand to separate and remove the aqueous layer. This operation was repeated twice, and then 16.2 g of toluene was added to the resulting organic layer to dilute it. 42.8 g of water and 10.7 g of isopropyl alcohol were added to the mixture, stirred for 15 minutes, and allowed to stand. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol in the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the second product was 5.4%, and the combined peak area of ​​the first and second products was 70.5%.

[0055] <Example 4> 194.2 g of reaction solution A from Example 3 was taken, and the temperature was raised again to 105-110°C to continue the reaction for another 6 hours. After the reaction solution was cooled to room temperature, 60.3 g of toluene was added to dilute it. 42.8 g of 10% by mass aqueous sodium hydroxide solution and 10.7 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. This process of separating and removing the aqueous layer was repeated twice. Then, 25.3 g of toluene was added to the resulting organic layer to dilute it. 42.8 g of water and 10.7 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol from the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product showed that the peak area of ​​the second product was 6.8%, and the combined peak area of ​​the first and second products was 70.7%.

[0056] <Example 5> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 81.6 g of 4,4'-diaminodiphenylmethane, 110.4 g of 2-allylphenol, and 245.8 g of toluene were added and dissolved at 75°C. Next, 53.8 g of 92% by mass paraformaldehyde was added in five portions, and the reaction mixture was heated to remove the water produced by the dehydration condensation reaction. The reaction mixture was further heated to 105-110°C and the reaction was continued for 6 hours. After the reaction mixture was cooled to room temperature, 65.8 g of toluene was added to dilute it. 98.3 g of 10% by mass aqueous sodium hydroxide solution and 24.6 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. After standing, the aqueous layer was separated and removed twice, and then 18.0 g of toluene was added to the resulting organic layer to dilute it. 98.3 g of water and 24.6 g of isopropyl alcohol were added to the mixture, stirred for 15 minutes, and allowed to stand. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol in the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the second product was 10.3%, and the combined peak area of ​​the first and second products was 67.3%.

[0057] <Comparative Synthesis Example 1> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 165.6 g of 2-allylphenol, 107.5 g of 92% paraformaldehyde, and 328.3 g of toluene were added and dissolved at 80°C. Next, a solution of 81.6 g of 4,4'-diaminodiphenylmethane and 55.2 g of 2-allylphenol dissolved in 81.6 g of toluene at 70°C was added dropwise over 6 hours, and the reaction mixture was heated to remove the water produced by the dehydration condensation reaction. The reaction mixture was further heated to 105-110°C and the reaction was continued for 20 minutes, after which the reaction mixture was cooled to room temperature. 98.3 g of 20% by mass aqueous sodium hydroxide solution and 24.6 g of isopropyl alcohol were added to the mixture and stirred for 15 minutes. After allowing the mixture to stand, the aqueous layer was separated and removed. This procedure was repeated three times. Then, 98.3 g of water and 24.6 g of isopropyl alcohol were added to the resulting organic layer and stirred for 15 minutes. After allowing the mixture to stand, the aqueous layer was separated and removed. This procedure was repeated five times. The water and isopropyl alcohol from the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product showed that the peak area of ​​the second product was 2.1%, and the combined peak area of ​​the first and second products was 82.6%.

[0058] <Comparative Example 1> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 122.4 g of 4,4'-diaminodiphenylmethane, 165.6 g of 2-allylphenol, and 368.6 g of toluene were added and dissolved at 75°C. Next, 70.6 g of 92% by mass paraformaldehyde was added in five portions, and the reaction solution was heated to remove the water produced by the dehydration condensation reaction. The reaction solution was further heated to 105-110°C and the reaction was continued for 6 hours, after which the reaction solution was cooled to room temperature (hereinafter this reaction solution will be referred to as "reaction solution B"). 200 g of reaction solution B was taken and diluted with 16.0 g of toluene. 42.8 g of 10% by mass sodium hydroxide aqueous solution and 10.7 g of isopropyl alcohol were added and stirred for 15 minutes, then allowed to stand to separate and remove the aqueous layer. This operation was repeated twice, and then 22.9 g of toluene was added to the resulting organic layer to dilute it. 42.8 g of water and 10.7 g of isopropyl alcohol were added to the mixture, stirred for 15 minutes, and allowed to stand. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol in the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the second product was 17.2%, and the combined peak area of ​​the first and second products was 67.2%.

[0059] <Comparative Example 2> 200 g of reaction solution B from Comparative Example 1 was taken, heated to 75°C, and 2.9 g of 92% by mass paraformaldehyde was added. The reaction solution was then heated further to 105-110°C and the reaction was continued for 2 hours. After the reaction solution was cooled to room temperature, 30.3 g of toluene was added to dilute it. 42.8 g of 10% by mass sodium hydroxide aqueous solution and 10.7 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. The aqueous layer was separated and removed twice. Then, 23.5 g of toluene was added to the resulting organic layer to dilute it. 42.8 g of water and 10.7 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. The aqueous layer was separated and removed five times. The water and isopropyl alcohol from the resulting organic layer were removed by vacuum distillation using a rotary evaporator, and the reaction product was obtained as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction products revealed that the peak area of ​​the second product was 4.1%, and the combined peak area of ​​the first and second products was 69.0%.

[0060] <Comparative Example 3> The reaction product obtained in Comparative Synthesis Example 1 and the reaction product obtained in Comparative Example 1 were mixed in a mass ratio of 6 / 4. When this mixture was analyzed by HPLC, the peak area of ​​the second product was 8.8%, and the combined peak area of ​​the first and second products was 77.3%.

[0061] <Comparative Example 4> In a 1 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 81.6 g of 4,4'-diaminodiphenylmethane, 110.4 g of 2-allylphenol, and 105.3 g of toluene were added and dissolved at 75°C. Next, 53.8 g of 92% by mass paraformaldehyde was added in five portions, and the reaction solution was heated to remove the water produced by the dehydration condensation reaction. The reaction solution was further heated to 105-110°C and the reaction was continued for 6 hours. After the reaction solution was cooled to room temperature, 238.4 g of toluene was added to dilute it. 98.3 g of 10% by mass aqueous sodium hydroxide solution and 24.6 g of isopropyl alcohol were added, and the mixture was stirred for 15 minutes. After standing, the aqueous layer was separated and removed twice, and then 30.7 g of toluene was added to the resulting organic layer to dilute it. 98.3 g of water and 24.6 g of isopropyl alcohol were added to the mixture, stirred for 15 minutes, and allowed to stand. This process of separating and removing the aqueous layer was repeated five times. The water and isopropyl alcohol in the resulting organic layer were removed by vacuum distillation using a rotary evaporator to obtain the reaction product as a toluene solution with a concentration of approximately 50% by mass. HPLC analysis of the obtained reaction product revealed that the peak area of ​​the second product was 10.0%, and the combined peak area of ​​the first and second products was 62.9%.

[0062] The mass loss rate and glass transition temperature were measured for the reaction products of Examples 1-5 and Comparative Examples 1-4. The results are shown in Tables 1 and 2.

[0063]

[0064]

[0065] In Comparative Examples 1 to 4, the mass loss rate was 12.2% by mass or more, whereas in Examples 1 to 5, the mass loss rate was 10.4% by mass or less, indicating a smaller mass loss rate. Therefore, outgassing during thermal curing was suppressed in the reaction products of Examples 1 to 5. Furthermore, in Examples 1 to 5, the glass transition temperature was 125°C or higher, whereas in Comparative Examples 1 and 2, where the peak area of ​​the second product deviated from the specified value, the glass transition temperature was lower.

[0066] Furthermore, the various numerical ranges described in this specification can be any combination of their upper and lower limits, and all such combinations are described herein as preferred numerical ranges. Also, the description of a numerical range as "X to Y" means X or greater and Y or less.

[0067] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their omissions, substitutions, and modifications are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0068] The reaction product according to this embodiment can produce a heat-resistant cured product while suppressing outgassing during thermal curing, and can therefore be used, for example, in printed circuit board materials, semiconductor encapsulating resins, matrix resins for composite materials, paints, adhesives, and the like.

Claims

1. A reaction product obtained by subjecting phenols, diamines, and formaldehyde to a condensation reaction, which contains a first product represented by the following formula (1) and a second product represented by the following formula (2). In the above formula (1) and formula (2), R １ represents -CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, or -O -, R ２ and R ３ each independently represent a methyl group or an ethyl group, R ４ and R ５ each independently represent an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, p and q each independently represent an integer of 0 to 4. With respect to 100% of the total peak area of the reaction product by HPLC, provided that when the reaction product contains a solvent, 100% of the total peak area excluding the solvent, the peak area of the second product is 5 to 15%, and the sum of the peak areas of the first product and the second product is 65 to 75%. A reaction product.

2. In equations (1) and (2) above, R １ ha-CH ２ The reaction product according to claim 1, wherein - or -O- represents a value, and p and q each independently represent an integer from 0 to 2.

3. The first product is represented by the following formula (3), and the second product is represented by the following formula (4), In equations (3) and (4) above, R ４ and R ５ The reaction product according to claim 1, wherein each of the elements independently represents an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms.

4. A cured product obtained by curing the reaction product according to any one of claims 1 to 3.

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