Resin composition and cured product thereof

Abstract

The present invention improves the glass transition temperature of a cured product. A resin composition according to an embodiment of the present invention contains a compound represented by formula (1) and a citraconimide represented by formula (2). In formula (1), R1 represents a divalent hydrocarbon group which may contain a hetero atom; R2 and R3 each represent an alkanediyl group having 1 to 10 carbon atoms; R4 and R5 each represent a hydrogen atom or a methyl group; R6 and R7 each represent a methyl group or an ethyl group; and p and q each represent an integer of 0 to 2. In formula (2), R8 represents an alkyl group having 1 to 3 carbon atoms; m represents an integer of 0 to 3; and n represents an average number of repeating units and is larger than 0.

Description

Resin composition and cured product thereof

[0001] Embodiments of the present invention relate to a resin composition containing benzoxazine and a cured product 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 when heated, as the benzoxazine ring undergoes ring-opening polymerization.

[0003] For example, Patent Document 1 discloses a benzoxazine having two benzoxazine rings in one molecule, obtained by condensing phenol with 4,4'-diaminodiphenylmethane and paraformaldehyde. Patent Document 2 discloses a benzoxazine 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] On the other hand, it is known that biscitraconimide is used as a printed circuit board material, for example. Biscitraconimide does not heat-cur on its own, but it is known that it can be heat-cured by adding a crosslinking agent (curing agent).

[0005] For example, Patent Document 3 describes that a resin material containing a maleimide compound having a skeleton derived from a dimer amine may have benzoxazine added as a curing agent, and that the maleimide compound may also be a citraconimide compound. Patent Document 4 describes that a lithography film-forming material containing a polycitraconimide compound may contain benzoxazine as a crosslinking agent.

[0006] Japanese Patent Publication No. 4647398, Japanese Unexamined Patent Publication No. 2018-184533, International Publication No. 2020 / 045408, International Publication No. 2020 / 004316

[0007] Some benzoxazines have an allyl group at the molecular terminal. Such a terminal unsaturated hydrocarbon group does not react through the thermal ring-opening polymerization of benzoxazine, but can be reacted with other polymerizable monomers. When such a benzoxazine having a terminal unsaturated hydrocarbon group is used, for example, as a printed circuit board material, it is required to increase the glass transition temperature of the cured product.

[0008] An object of an embodiment of the present invention is to increase the glass transition temperature of a cured product in a resin composition containing a benzoxazine having a terminal unsaturated hydrocarbon group.

[0009] The present invention includes the embodiments shown below. [1] Comprises a compound represented by the following general formula (1) and a citraconimide represented by the following general formula (2), In formula (1), R １ represents a divalent hydrocarbon group having 1 to 100 carbon atoms which may contain a hetero atom, R ２ and R ３ each independently represent an alkanediyl group having 1 to 10 carbon atoms, R ４ and R ５ each independently represent a hydrogen atom or a methyl group, R ６ and R ７ each independently represent a methyl group or an ethyl group, p and q each independently represent an integer of 0 to 2, In formula (2), R ８ each independently represent an alkyl group having 1 to 3 carbon atoms, m each independently represents an integer of 0 to 3, and n is the average number of repeating units and represents a number greater than 0. The resin composition.

[0010] [2] The resin composition according to [1], wherein R １ in the formula (1) is a divalent aromatic ring-containing hydrocarbon group having 6 to 50 carbon atoms which may contain a hetero atom.

[0011] [3] The compound represented by the formula (1) is represented by the following general formula (1A), In formula (1A), R １１ is a single bond, -CH ２ -, -CH(CH ３ )-, -C(CH ３ )２ - or -O- represents R １２ and R １３ Each independently represents a methyl group or an ethyl group, and s and t each independently represent an integer from 0 to 4, R ２ and R ３ Each of these independently represents an alkanediyl group having 1 to 10 carbon atoms, R ４ and R ５ Each of these independently represents a hydrogen atom or a methyl group, R ６ and R ７ The resin composition according to [1] or [2], wherein each represents independently a methyl group or an ethyl group, and p and q each represent independently an integer from 0 to 2.

[0012] [4] The resin composition according to any one of [1] to [3], wherein n in formula (2) is 0.10 to 15.0.

[0013] [5] A resin composition according to any one of [1] to [4], used as a printed circuit board material.

[0014] [6] A cured product obtained by curing the resin composition described in any one of items [1] to [5].

[0015] [7] Use of the resin composition described in any one of items [1] to [4] as a printed circuit board material.

[0016] According to embodiments of the present invention, the glass transition temperature of a cured product can be improved in a resin composition containing benzoxazine having terminally unsaturated hydrocarbon groups.

[0017] The resin composition according to this embodiment contains a compound represented by the following general formula (1) (hereinafter referred to as compound (1)). Compound (1) is a compound composed of one molecule of diamine, two molecules of phenols, and four molecules of formaldehyde, and has two benzoxazine rings in its molecule.

[0018] In equation (1), R １ R represents a divalent hydrocarbon group having 1 to 100 carbon atoms, which may contain heteroatoms. １The number of carbon atoms in the hydrocarbon group is preferably 2 to 70, more preferably 3 to 50, more preferably 5 to 30, and even more preferably 6 to 20. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, fluorine atoms, silicon atoms, etc., and oxygen atoms are preferred, but R １ It is preferable that it does not contain heteroatoms.

[0019] R １ The hydrocarbon group preferably contains an aromatic ring (i.e., is an aromatic ring-containing hydrocarbon group), more preferably contains a benzene ring, and even more preferably contains two or three benzene rings. Therefore, R １ The number of carbon atoms in the hydrocarbon group is preferably 6 to 50, more preferably 12 to 30, and even more preferably 12 to 20.

[0020] In equation (1), R ２ and R ３ Each of these independently represents an alkanediyl group (also called an alkylene group) having 1 to 10 carbon atoms. The alkanediyl group may be a straight chain or a branched chain. Preferably, R ２ and R ３ Each of these is independently an alkanediyl group having 1 to 5 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms, and more preferably an ethylene group (-CH ２ CH ２ -) or methylene group (-CH ２ -) and more preferably a methylene group.

[0021] In equation (1), R ４ and R ５ Each of these independently represents a hydrogen atom or a methyl group, and more preferably a hydrogen atom. ２ C=CR ４ R ２ - and H ２ C=CR ５ R ３ The unsaturated hydrocarbon group represented by - has an allyl group (H) at its terminal end. ２ C = CH - CH ２ -) or methallyl group (H ２ C = C(CH) ３ ) - CH２ CR ４ or CR ５ It is preferable that the carbon adjacent to it is a methylene group.

[0022] In equation (1), R ６ and R ７ Each independently represents a methyl group or an ethyl group, more preferably a methyl group. In formula (1), p and q each independently represent an integer from 0 to 2, more preferably independently 0 or 1, and even more preferably 0.

[0023] In equation (1), H ２ C=CR ４ R ２ - and H ２ C=CR ５ R ３ An unsaturated hydrocarbon group represented by - and R ６ and R ７ With respect to the substituents represented by , it is preferable that their bonding positions to the benzene ring be set as follows: One unsaturated hydrocarbon group and 0 to 2 substituents are bonded to the benzene ring, provided that at least one of the ortho or para positions relative to the oxygen atom bonded to the benzene ring is unsubstituted (i.e., a hydrogen atom). Preferably, the unsaturated hydrocarbon group is bonded to the ortho position relative to the oxygen atom.

[0024] Compound (1) is more preferably represented by the following general formula (1A).

[0025] In equation (1A), R １１ This is a single bond, -CH ２ -, -CH(CH ３ )-,-C(CH ３ ) ２ Represents - or -O-. １１ Preferably, a single bond, -CH ２ -, or -O-, more preferably a single bond or -CH ２ - is the case. R for the two benzene rings １１ The binding site is Ph-R １１ - A group represented by Ph (where Ph is substituent R) １２ or R１３ represents a benzene ring which may have a substituent. As for the bonding position of the benzoxazine ring relative to it, 4,4'-position, 3,4'-position, or 3,3'-position is preferred.

[0026] In formula (1A), R １２ and R １３ each independently represent a methyl group or an ethyl group, more preferably a methyl group. R １２ and R １３ , when a plurality of them are present in one molecule, may be the same or different. s and t each independently represent an integer of 0 to 4, more preferably an integer of 0 to 2, and still more preferably 0 or 1.

[0027] In formula (1A), R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , p and q are the same as R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , p and q in formula (1), respectively.

[0028] In one embodiment, the compound (1) is preferably represented by the following general formula (1B). In formula (1B), R １１ , R １２ , R １３ , R ２ , R ３ , R ４ , R ５ , s and t are the same as R １１ , R １２ , R １３ , R ２ , R ３ , R ４ , R ５ , s and t in formula (1A), respectively.

[0029] In one embodiment, the compound (1) may be a compound represented by the following general formula (1C). In formula (1C), R ２ , R ３, R ４ and R ５ These are R in equation (1A), respectively. ２ , R ３ , R ４ and R ５ It is the same as this.

[0030] In one embodiment, compound (1) may be a compound represented by the following general formula (1D). In equation (1D), R １２ , R １３ , R ２ , R ３ , R ４ and R ５ These are R in equation (1A), respectively. １２ , R １３ , R ２ , R ３ , R ４ and R ５ It is the same as this.

[0031] The method for producing compound (1) is not particularly limited, and can be obtained, for example, by condensing phenols, diamines, and formaldehyde. More specifically, in the presence of a solvent, phenols represented by the following formula (3), diamines represented by the following formula (4), and formaldehyde (e.g., paraformaldehyde, i.e., (HClO)) ｎ One method involves stirring and mixing the two components and then carrying out a dehydration condensation reaction under heating. After the condensation reaction, the product may be purified by liquid-liquid washing, recrystallization, column purification, etc.

[0032] In equation (3), R １４ H ２ C=CR ４ R ２ - or H ２ C=CR ５ R ３ - represents, and here, R ２ , R ３ , R ４ and R ５ These are R in equation (1), respectively. ２ , R ３ , R ４ and R ５ It is the same as R １５ R in equation (1) above６ or R ７ It is the same as. r is the same as p or q in equation (1). In equation (4), R １ R in equation (1) above １ It is the same as this.

[0033] 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 dimethylformamide. These may be used individually or in combination of two or more.

[0034] 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.

[0035] The reaction products obtained by the condensation reaction described above typically include compound (1) as the main product, as well as by-products such as a one-ring open compound in which one of the two benzoxazine rings of compound (1) is not closed, and polymers (including oligomers) of compound (1). The resin composition according to the embodiment may include compound (1) and a by-product corresponding to compound (1) as benzoxazine. That is, compound (1) and the by-product (as an optional component) corresponding to compound (1) are collectively referred to as benzoxazine, and the resin composition according to the embodiment contains this benzoxazine. The proportion of compound (1) in the benzoxazine is not particularly limited, but is preferably 40% or more, more preferably 45% or more, and even more preferably 50% or more. There is no particular upper limit, but the proportion of compound (1) is usually 80% or less, and may be 70% or less. Here, the proportion of compound (1) is the ratio of peak areas by GPC.

[0036] The resin composition according to this embodiment contains a citraconimide represented by the following general formula (2) (hereinafter referred to as citraconimide (CI)). Citraconimide (CI) has multiple citraconimide groups in one molecule and is therefore also called polycitraconimide.

[0037] In equation (2), R ８ Each of the following independently represents an alkyl group having 1 to 3 carbon atoms, preferably a methyl group or an ethyl group. Each of the following independently represents an integer from 0 to 3, preferably 0 or 1, more preferably 0.

[0038] In equation (2), n is the average number of repeating units and represents a number greater than 0. That is, n is -CH ２ A repeating unit represented by -Ph(Ci)- (where Ph is substituent R) ８ This represents a benzene ring which may have a citraconimide group, where Ci represents a citraconimide group. The number of repeating units is the average value, and n > 0. By including a compound with one or more repeating units in this way, solvent solubility can be improved.

[0039] The average number of repeating units n is preferably 0.10 to 15.0, more preferably 0.10 to 10.0, more preferably 0.10 to 5.0, more preferably 0.10 to 2.0, even more preferably 0.10 to 1.5, and particularly preferably 0.10 to 1.0, from the viewpoint of solvent solubility and low water absorption. The average number of repeating units n is a value calculated from the number-average molecular weight Mn obtained by GPC.

[0040] In formula (2), the bonding positions of the citraconimide group and the methylene group to the benzene ring are not particularly limited and may be ortho, meta, or para, preferably ortho or para.

[0041] Citraconimide (CI) may be a mixture containing multiple compounds with different numbers of repeating units, and is usually such a mixture. In one embodiment, it is preferable that the peak area ratio of compounds with zero repeating units in the citracomimide (CI) by GPC is 65% or less. Citraconimide (CI) may consist only of compounds with one or more repeating units, but may also contain compounds with zero repeating units and compounds with one or more repeating units (for example, compounds with 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4 repeating units). For example, in terms of GPC peak area ratio, citracomimide (CI) may contain 5 to 65% (preferably 15 to 60%, more preferably 30 to 60%, and even more preferably 40 to 60%) of compounds with zero repeating units and 35 to 95% (preferably 40 to 85%, more preferably 40 to 70%, and even more preferably 40 to 60%) of compounds with one or more repeating units.

[0042] The number-average molecular weight Mn of citraconimide (CI) determined by GPC is not particularly limited and may be, for example, 400 to 3000, 400 to 2000, 400 to 1500, 400 to 1000, 400 to 800, or 400 to 600.

[0043] The method for producing citraconiamide (CI) is not particularly limited, and can be obtained, for example, by dehydrating citraconic anhydride with a condensate of substituted or unsubstituted aniline and formaldehyde.

[0044] The resin composition according to the embodiment is a thermosetting resin composition comprising compound (1) and citraconimide (CI). Specifically, since compound (1) has a benzoxazine ring, it is cured (thermosetting) by thermal ring-opening polymerization as a monomer. Also, the H of compound (1) ２ C=CR ４ R ２ - and H ２ C=CR ５ R ３ The unsaturated hydrocarbon group represented by - reacts with the citracomide group of citracomide (CI), causing the citracomide (CI) to thermally cure together with compound (1). Therefore, the cured product of the resin composition according to the embodiment is expected to have an improved glass transition temperature compared to the case where compound (1) is cured alone. Furthermore, in the resin composition according to the embodiment, citracomide (CI) has higher solvent solubility compared to its similar substance, bismaleimide. In addition, the resin composition according to the embodiment has high reactivity in the curing reaction and excellent moldability of the cured product. Moreover, the resin composition according to the embodiment has a low water absorption rate and excellent low water absorption properties.

[0045] In the resin composition according to the embodiment, the blending ratio of compound (1) to citraconimide (CI) is not particularly limited, but in one embodiment it may be set as follows. Since compound (1) is usually produced together with by-products such as ring-opened products and polymers as described above, it is preferable to set the blending ratio with citraconimide (CI) as a benzoxazine containing these by-products. That is, the mass ratio of benzoxazine (BZO) consisting of compound (1) and its by-products to citraconimide (CI), i.e., the mass ratio of BZO to CI, BZO / CI, is preferably 0.35 to 4.0, more preferably 0.4 to 3.0, and more preferably 0.8 to 2.0. By setting BZO / CI to 4.0 or less, the effect of improving the glass transition temperature of the cured product can be enhanced. By setting BZO / CI to 0.35 or more, the moldability and low water absorption of the cured product can be improved.

[0046] The resin composition according to the embodiment may consist only of the above-mentioned benzoxazine (BZO) containing compound (1) and citraconimide (CI), or it may contain, for example, other thermosetting resins and / or thermoplastic resins together with BZO and CI. The resin composition may also contain various known additives such as solvents, catalysts, crosslinking agents, curing accelerators, colorants, radical polymerization initiators, leveling agents, flame retardants, antioxidants, and inorganic fillers.

[0047] In the resin composition, the total amount of benzoxazine (BZO) and citraconimide (CI), excluding the solvent, is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and may be 100% by mass. In one embodiment, the resin composition is a resin solution containing a solvent. In that case, the solvent content in the resin composition is not particularly limited and may be, for example, 30 to 70% by mass or 40 to 60% by mass.

[0048] Examples of solvents included in the resin composition are organic solvents capable of dissolving benzoxazine (BZO) and citraconimide (CI), such as toluene, xylene, cumene, monochlorobenzene, methyl ethyl ketone, ethyl acetate, butyl acetate, chloroform, dichloromethane, THF, dioxane, and dimethylformamide. These may be used individually or in combination of two or more. Aromatic hydrocarbon solvents and ketone solvents are preferred as solvents. Furthermore, non-halogen solvents with a boiling point of 150°C or lower are preferred from the viewpoint of ease of removal of the solvent by evaporation during curing.

[0049] Examples of catalysts included in the resin composition include imidazole-based catalysts such as 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, and 1,2-dimethylimidazole, and organophosphorus-based catalysts such as triphenylphosphine and tributylphosphine.

[0050] The cured product according to this embodiment is obtained by curing the above resin composition, which is usually cured by heating. The curing conditions are not particularly limited, and for example, heating may be performed at 150°C to 250°C for 30 to 180 minutes. If the resin composition contains a solvent, the solvent may be evaporated by heating, and then the temperature may be further increased to perform thermal curing.

[0051] The resin composition according to this embodiment can be used in a variety of applications, such as electrical insulating materials and matrix resins for composite materials.

[0052] In one embodiment, the resin composition is preferably used as a printed circuit board material. That is, the printed circuit board material according to one embodiment includes a resin composition containing compound (1) and citraconimide (CI). Using this printed circuit board material, printed circuit boards such as printed wiring boards and printed circuit boards according to one embodiment can be manufactured.

[0053] Examples of printed circuit board materials include rigid printed circuit board materials for manufacturing single-sided boards, double-sided boards, multilayer boards, and build-up boards, as well as flexible printed circuit board materials for manufacturing film-like or sheet-like flexible printed circuit boards.

[0054] The present invention will be described in more detail below based on examples and comparative examples, but it is not limited thereto.

[0055] <Measurement and Evaluation Method> [Purity of the main product in benzoxazine] BZO1-4 obtained in Synthesis Examples 1-2 and Comparative Synthesis Examples 1-2 were dissolved in THF to a reaction product concentration of approximately 0.2 mg / mL, and GPC measurements were performed using gel permeation chromatography (GPC) (Prominence, Shimadzu Corporation) with four columns (Shodex GPC columns KF-601, KF-602, KF-603, KF-604, manufactured by Resonaq Corporation) lined up with polystyrene gel as the packing material. The measurement conditions were a column oven temperature of 40°C and a flow rate of 0.6 mL / min, and a differential refractive index detector (Shodex RI-504, manufactured by Resonaq Corporation) was used. From the obtained chromatogram, peaks originating from the solvent (toluene) were removed, and the purity of the main product was calculated as the ratio (%) of the peak area.

[0056] [Compositional Analysis of Citraconimide] For CI1 and CI2 obtained in Synthesis Examples 3 and 5, GPC measurements were performed in the same manner as for the purity of the main product in benzoxazine described above, and the peak area ratio of compounds with zero repeating units was measured. The peak positions of compounds with zero repeating units were assigned by GPC measurements of 4,4'-biscitraconimide diphenylmethane.

[0057] [Number-average molecular weight Mn] For CI1 and CI2 obtained in Synthesis Examples 3 and 5, and MI1 obtained in Comparative Synthesis Example 3, GPC measurements were performed in the same manner as for the purity of the main product in benzoxazine described above, and the number-average molecular weight Mn in terms of polystyrene was measured.

[0058] [Solubility] Each component was mixed according to the formulations shown in Tables 1 and 2 (units are in grams). The mixture that dissolved uniformly at room temperature was classified as "A", the mixture that dissolved uniformly after heating to 50°C was classified as "B", and the mixture that still contained insoluble matter even after heating to 50°C was classified as "C".

[0059] [Moldability] For the examples and comparative examples in which the solubility evaluation above was A or B, the resin composition prepared with the formulation (g) shown in Table 1 or Table 2 was placed in an aluminum cup 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 heating on a hot plate at 120°C for 1 hour. The hot plate was then heated to 250°C for 1 hour to perform heat curing, and a flat plate was produced by allowing it to cool to room temperature. Plates with significant appearance defects such as bubbles, cracks, and curing defects were classified as "B", while those with minor or no such appearance defects were classified as "A".

[0060] [Glass Transition Temperature (Tg)] For the examples and comparative examples where the solubility evaluation above was A or B, the resin composition prepared with the formulation (g) shown in Table 1 or Table 2 was placed in an aluminum cup 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. The hot plate was then heated to 250°C for 1 hour to perform thermosetting, and a flat plate was produced by allowing it to cool to room temperature. For those where the moldability evaluation above was A, a test piece with a width of 5 mm, a thickness of approximately 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 temperature at which the loss tangent (tanδ), measured under conditions of tensile sine wave, dynamic strain of 5 μm, frequency of 1 Hz, and heating rate of 3°C / min, took its maximum value was determined as the glass transition temperature.

[0061] [Water Absorption Rate] Test specimens similar to those used for measuring the glass transition temperature in Examples 1 to 9 and Comparative Example 7 were prepared, and the percentage increase in mass before and after immersion in water at 25°C for 24 hours was measured and calculated as the 25°C water absorption rate. Similarly, the percentage increase in mass before and after immersion in water at 40°C for 24 hours was measured and calculated as the 40°C water absorption rate.

[0062] <Synthesis 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 aqueous sodium hydroxide solution was added, stirred for 15 minutes, and 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 (IPA) were added to the resulting organic layer, stirred for 15 minutes, and allowed to stand to separate and remove the aqueous layer. This procedure was repeated five times. The water and IPA from the obtained organic layer were removed by vacuum distillation using a rotary evaporator to obtain a toluene solution (BZO1) containing the reaction product at a concentration of 49.8% by mass. The obtained reaction product was a benzoxazine containing the compound represented by the following formula as the main product, and the purity of the main product by GPC was 56.2%.

[0063] <Synthesis Example 2> In a 5 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 436.9 g of 4,4'-diamino-2,2'-dimethylbiphenyl, 552.0 g of 2-allylphenol, and 1257.6 g of toluene were added and dissolved at 75°C. Next, 268.7 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, 168.4 g of toluene was added to dilute it. 503.0 g of 10% by mass aqueous sodium hydroxide solution and 125.8 g of IPA were added, and the mixture was stirred for 15 minutes. After standing, the aqueous layer was separated and removed twice, and then 179.2 g of toluene was added to the resulting organic layer to dilute it. 503.0 g of water and 125.8 g of IPA 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 IPA from the resulting organic layer were removed by vacuum distillation to obtain a toluene solution (BZO2) containing the reaction product at a concentration of 51.4% by mass. The resulting reaction product was a benzoxazine containing the compound represented by the following formula as the main product, and the purity of the main product by GPC was 61.7%.

[0064] <Synthesis Example 3> In a 3 L reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 200.4 g of citraconic anhydride and 1135.6 g of toluene were added and mixed. A solution of 160.0 g of polydiaminodiphenylmethane (WANAMINE MDA-60R, manufactured by WANHUA CHEMICAL GROUP CO., LTD) dissolved in 480.0 g of N-methylpyrrolidone (NMP) was added dropwise and the mixture was reacted for 30 minutes. After adding 15.5 g of p-toluenesulfonic acid monohydrate to this reaction solution, the reaction solution was heated and the reaction was continued at 105-115°C for 4 hours while distilling off the water produced by the dehydration condensation reaction, and then the reaction solution was cooled. 480.0 g of water was added to the mixture, and the mixture was stirred at 55-65°C. After allowing it to stand, the aqueous layer was separated and removed. This process was repeated three times. The resulting organic layer was then concentrated using a rotary evaporator to obtain a toluene solution (CI1) containing the reaction product at a concentration of 67.8% by mass. The resulting reaction product was citraconimide, represented by the following formula, with a manganese (Mn) of 410. The peak area ratio of the compound with 0 repeating units, as determined by GPC, was 58.5%. The average number of repeating units (n) calculated from Mn was 0.12.

[0065] <Synthesis Example 4> In a 300 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 47.3 g of aniline and 25.3 g of 35% by mass aqueous hydrochloric acid solution were added and the temperature was raised to 60°C. 30.9 g of 37% by mass aqueous formaldehyde solution was added dropwise over 30 minutes and the reaction was carried out at 80°C for 1 hour. The reaction was continued at 120°C while raising the temperature of the reaction mixture and distilling off the water from the system, and the reaction was carried out for another 30 minutes after no more water was distilled off. After cooling to 90°C, 30.7 g of 30% by mass aqueous sodium hydroxide solution was added dropwise to neutralize the mixture, and the system was allowed to cool to below 50°C. 100.0 g of chloroform was added to dissolve the product, 100.0 g of water was added and stirred, and the aqueous layer was separated and removed. This procedure was repeated three times. The resulting organic layer was concentrated using a rotary evaporator and then vacuum-dried at 80°C to obtain an aniline formaldehyde condensate with an amine value of 539.7 mg-KOH / g.

[0066] <Synthesis Example 5> In a 300 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 23.7 g of citraconic anhydride, 134.3 g of toluene, and 30.0 g of N-methylpyrrolidone (NMP) were added and mixed. A solution of 20.0 g of the aniline formaldehyde condensate synthesized in Synthesis Example 4 dissolved in 30.0 g of NMP was added dropwise and the mixture was allowed to react for 30 minutes. After adding 1.8 g of p-toluenesulfonic acid monohydrate to this reaction solution, the reaction was heated and the water produced by the dehydration condensation reaction was removed from the system by distillation while the reaction was continued at 105-115°C for 4 hours, and the reaction solution was cooled. After removing the toluene from this reaction solution by reduced pressure, it was diluted with 134.3 g of methyl ethyl ketone (MEK). 60.0 g of water was added to the mixture, stirred, and allowed to stand. The aqueous layer was separated and removed four times. The resulting organic layer was then concentrated in a rotary evaporator to a solution of approximately 60% by mass. This solution was poured into 762 g of methanol, the precipitated solid was collected, and the reaction product (CI2) was obtained by vacuum drying at 80°C. The obtained reaction product was citraconimide represented by the formula described in Synthesis Example 3, with a Mn of 650. The peak area ratio by GPC for the compound with 0 repeating units was 20.1%. The average number of repeating units n calculated from Mn was 1.3.

[0067] <Comparative Synthesis Example 1> 79.3 g of 4,4'-diaminodiphenylmethane, 75.3 g of phenol, and 206.8 g of toluene were added to a 500 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, and dissolved at 75°C. Next, 52.2 g of 92% by mass paraformaldehyde was added in five portions. The reaction solution was heated to 105°C over approximately 3 hours, and after the water produced by the dehydration condensation reaction was removed from the system, the reaction solution was cooled to room temperature. This reaction solution was poured into 1034 g of IPA, the precipitated solid was collected, and the reaction product (BZO3) was obtained by vacuum drying at 50°C. The obtained reaction product was a benzoxazine containing the compound represented by the following formula as the main product, and the purity of the main product by GPC analysis was 44.1%.

[0068] <Comparative Synthesis Example 2> In a 300 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 21.2 g of 4,4'-diamino-2,2'-dimethylbiphenyl, 18.8 g of phenol, and 53.0 g of toluene were added and dissolved at 75°C. Next, 13.0 g of 92% by mass of 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 4 hours, after which the reaction mixture was cooled to room temperature. This reaction mixture was poured into 530 g of methanol, the precipitated solid was collected, and the reaction product (BZO4) was obtained by vacuum drying at 40°C. The obtained reaction product was a benzoxazine containing the compound represented by the following formula as the main product, and the purity of the main product by GPC analysis was 45.1%.

[0069] <Comparative Synthesis Example 3> In a 500 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 43.8 g of maleic anhydride, 65.7 g of toluene, and 60.0 g of NMP were added and mixed. A solution of 40.0 g of polydiaminodiphenylmethane (WANAMINE MDA-60R, manufactured by WANHUA CHEMICAL GROUP CO., LTD) dissolved in 60.0 g of NMP was added dropwise and the mixture was reacted for 30 minutes. After adding 3.9 g of p-toluenesulfonic acid monohydrate to this reaction solution, the reaction solution was heated and the reaction was continued at 105-120°C for 4 hours while distilling off the water produced by the dehydration condensation reaction, and then the reaction solution was cooled. After distilling off the toluene in this reaction solution under reduced pressure, it was poured into 1450 g of water and the precipitated crude crystals were recovered. Furthermore, the crude crystals were dissolved in methyl ethyl ketone (MEK) at a concentration of 2.3 times the mass of the crude crystals, then poured into 20 times the mass of water, and the precipitated solid was vacuum-dried at 70-80°C to obtain the reaction product (MI1). The obtained reaction product was maleimide represented by the following formula, and its Mn value was 520.

[0070] <Comparative Synthesis Example 4> In a 300 mL reactor equipped with a condenser, a Dean-Stark apparatus, and a stirrer, 20.7 g of maleic anhydride, 117.3 g of toluene, and 30.0 g of N-methylpyrrolidone (NMP) were added and mixed. A solution of 20.0 g of the aniline formaldehyde condensate synthesized in Synthesis Example 4 dissolved in 30.0 g of NMP was added dropwise and the mixture was reacted for 30 minutes. After adding 1.8 g of p-toluenesulfonic acid monohydrate to this reaction solution, the reaction solution was heated and the reaction was continued at 105-115°C for 4 hours while distilling off the water produced by the dehydration condensation reaction, and then the reaction solution was cooled. After distilling off the toluene in this reaction solution under reduced pressure, it was diluted with 117.3 g of methyl ethyl ketone (MEK). 120.0 g of water was added and stirred, then allowed to stand and separate and remove the aqueous layer once. 60.0 g of water was added and stirred, then allowed to stand and separate and remove the aqueous layer once. The resulting organic layer was then diluted with 57.5 g of MEK. Another 60.0 g of water was added and stirred at 45-55°C, then allowed to stand and separate and remove the aqueous layer twice. The resulting organic layer was then concentrated in a rotary evaporator to a solution of approximately 70% by mass. This solution was poured into 708 g of methanol, the precipitated solid was collected, and the reaction product (MI2) was obtained by vacuum drying at 80°C. The obtained reaction product was maleimide represented by the formula described in Comparative Synthesis Example 3, with a Mn value of 660.

[0071] <Examples 1-5 and Comparative Examples 1-4> Resin compositions for Examples 1-5 and Comparative Examples 1-4 were prepared according to the formulations shown in Table 1 below, and their solubility, moldability, glass transition temperature (Tg), and water absorption rate were evaluated or measured. In the table, "BZO / CI" refers to the mass ratio of benzoxazine (BZO) to citraconimide (CI), except for Comparative Examples 2 and 3, where it refers to the mass ratio of benzoxazine (BZO) to maleimide (MI).

[0072]

[0073] As shown in Table 1, the resin compositions of Examples 1 to 5, which used allyl group-containing benzoxazine BZO1 and citraconimide CI1 and CI2 in combination, showed a significantly improved glass transition temperature of the cured product compared to the resin composition of Comparative Example 1, which used allyl group-containing benzoxazine BZO1 alone. Furthermore, while Comparative Examples 2 and 3, which used the similar substance maleimide MI1 and MI2 instead of citraconimide CI1 and CI2, exhibited inferior solvent solubility, Examples 1 to 5, which used citraconimide CI1 and CI2 in combination, showed better solvent solubility and superior moldability compared to Comparative Examples 2 and 3. Examples 1 to 5 also exhibited excellent low water absorption. In addition, Comparative Example 4, which used benzoxazine BZO3 without an allyl group, showed inferior moldability compared to Examples 1 to 5, and a satisfactory cured product could not be obtained.

[0074] <Examples 6-9 and Comparative Examples 5-9> Resin compositions for Examples 6-9 and Comparative Examples 5-9 were prepared according to the formulations shown in Table 2 below, and their solubility, moldability, glass transition temperature (Tg), and water absorption rate were evaluated or measured. In the table, "BZO / CI" refers to the mass ratio of benzoxazine (BZO) to citraconimide (CI), except for Comparative Example 6, where it refers to the mass ratio of benzoxazine (BZO) to maleimide (MI).

[0075]

[0076] As shown in Table 2, the resin compositions of Examples 6 to 9, which used allyl group-containing benzoxazine BZO2 and citraconimide CI1 in combination, showed a significantly improved glass transition temperature of the cured product compared to the resin composition of Comparative Example 5, which used allyl group-containing benzoxazine BZO2 alone. Furthermore, while Comparative Example 6, which used maleimide MI1, a similar substance, instead of citraconimide CI1, exhibited poor solvent solubility, Examples 6 to 9, which used citraconimide CI1 in combination, showed better solvent solubility than Comparative Example 6. In addition, the resin composition of Comparative Example 7, which used another allyl group-containing compound (allyl 1) instead of allyl group-containing benzoxazine BZO2, showed good solvent solubility and moldability, and a cured plate could be obtained, but its Tg was significantly lower than that of the examples. Furthermore, the resin composition of Comparative Example 8, which used another allyl group-containing compound (allyl 2) instead of allyl group-containing benzoxazine BZO2, showed poor solvent solubility due to the generation of insoluble matter upon addition of catalyst 2E4MZ. Furthermore, in the resin composition of Comparative Example 9, which used benzoxazine BZO4 without an allyl group, the moldability deteriorated, a satisfactory cured plate could not be obtained, and test specimens for measuring the glass transition temperature could not be obtained.

[0077] 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.

[0078] 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.

[0079] The resin composition according to this embodiment can 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 compound represented by the following general formula (1) and a citraconimide represented by the following general formula (2) are included. In formula (1), R １ R represents a divalent hydrocarbon group having 1 to 100 carbon atoms, which may contain heteroatoms. ２ and R ３ Each of these independently represents an alkanediyl group having 1 to 10 carbon atoms, R ４ and R ５ Each of these independently represents a hydrogen atom or a methyl group, R ６ and R ７ Each of these independently represents either a methyl group or an ethyl group, and each of p and q independently represents an integer between 0 and 2. In formula (2), R ８ A resin composition in which each of the following independently represents an alkyl group having 1 to 3 carbon atoms, each of the following independently represents an integer from 0 to 3, and n represents the average number of repeating units, which is a number greater than 0.

2. R in the above formula (1) １ is a divalent aromatic ring-containing hydrocarbon group having 6 to 50 carbon atoms which may optionally contain a hetero atom, the resin composition according to claim 1.

3. The compound represented by formula (1) above is represented by the following general formula (1A), In formula (1A), R １１ This is a single bond, -CH ２ -, -CH(CH ３ )-,-C(CH ３ ) ２ - or -O- represents R １２ and R １３ Each independently represents a methyl group or an ethyl group, and s and t each independently represent an integer from 0 to 4, R ２ and R ３ Each of these independently represents an alkanediyl group having 1 to 10 carbon atoms, R ４ and R ５ Each of these independently represents a hydrogen atom or a methyl group, R ６ and R ７ The resin composition according to claim 1, wherein each of the following independently represents a methyl group or an ethyl group, and p and q each independently represent an integer from 0 to 2.

4. The resin composition according to claim 1, wherein n in formula (2) is 0.10 to 15.

0.

5. A resin composition according to any one of claims 1 to 4, which is used as a printed circuit board material.

6. A cured product obtained by curing the resin composition according to any one of claims 1 to 4.

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