Novel bismaleimide compounds with improved solubility and their use in curable compositions

Abstract

The present invention relates to certain bismaleimide compounds, curable compositions comprising at least one of these bismaleimides and at least one specific polyimide. Furthermore, the present invention relates to a method for producing these curable compositions and to the crosslinked polymers obtained by this method. Finally, the present invention relates to a method for producing a composite material, comprising curing a mixture of a fibrous or particulate reinforcing material and the curable composition or crosslinked polymer of the present invention, and to the composite material obtained.

Description

[Technical Field]

[0001] The present invention relates to a curable composition comprising a specific bismaleimide compound, at least one of these bismaleimides, and at least one specific polyimide. Furthermore, the present invention relates to a method for producing these curable compositions and a crosslinked polymer obtained by this method. Finally, the present invention relates to a method for producing a composite material comprising curing a mixture of a fibrous or particulate reinforcing material and the curable composition or crosslinked polymer of the present invention, and the resulting composite material.

[0002] Commercially available bismaleimide (BMI) monomers, including aliphatic monomers, are known to have low solubility. Therefore, producing solvent-based formulations with high resin content used in the manufacture of printed circuit boards requires the use of prepolymerized or chain-extended BMI, which imposes additional manufacturing costs, toxic chain extenders, and increased solution viscosity (Evsyukov, et al., Curr. Trends Polym. Sci, 2020, 20, 1-28). Alternatively, some degree of highly toxic, high-boiling-point amide solvents can be used (even with these potent solvents, the solubility of BMI remains limited).

[0003] Highly soluble aliphatic BMIs are required for the economical production of solution-treated prepregs and fiber-reinforced laminates therefrom. To date, no alternative aliphatic BMIs are known that offer high solubility and high heat resistance. Branched aliphatic C 36Dimerized BMI, also known as X-BMI (DeFusco, et al., NWC Tech. Publ. 6543, Naval Weapons Center, China Lake, California, USA, 1984; Dershem et al., U.S. Patent No. 7102015, 2006), based on dimerized diamines, is readily soluble in organic solvents, but its cured form has low heat resistance due to the long distance between functionalized maleimide groups. As a result, cured resins based on X-BMI have been reported to exhibit a glass transition temperature (Tg) in the range of 60-95°C, which is about 200°C lower than that of standard BMI resins (Gouzman, et al., Adv. Mater. Technol., 2019, 4, 1900368; Evsyukov, et al., Curr. Trends Polym. Sci, 2020, 20, 1-28).

[0004] Furthermore, for the production of BMI and BMI / comonomer products, it is desirable to improve the processability of solution-based BMI resins. Due to increasing limitations on the use of toxic amide-type solvents, which are typical BMI processing solvents in the prior art, there is a need to develop resins that can be processed from conventional low-boiling point solvents, preferably below 120°C, and more preferably below 100°C.

[0005] In addition, improved solubility should also improve compatibility with other monomers and comonomers in the hot melt formulation.

[0006] Therefore, the object of the present invention was to provide BMI having a high solubility of preferably at least 30%, more preferably at least 34%, in preferably at least three low-boiling point solvents.

[0007] Surprisingly, it has been found that using a specific propane-1,3-diamine as a starting material in standard BMI synthesis (reaction with maleic anhydride followed by dehydration and cyclization) results in the formation of a highly soluble bismaleimide of formula (I) that can be used in solution-based BMI formulations and hot-melt formulations in conventional low-boiling solvents without, for example, prepolymerization or chain extension. Due to its high solubility in conventional low-boiling solvents, high-concentration solutions can be obtained without prepolymerization or chain extension.

[0008] In this invention, 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine was used as an exemplary compound of a specific propane-1,3-diamine. It has been described that 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine is suitable for use as a curing agent in epoxy resin compositions by (i) the reaction of isophorone with malononitrile and (ii) the hydrogenation of 2-(3,5,5-trimethylcyclohex-2-ene-1-ylidene)malononitrile(II) with a cobalt alloy catalyst. Partial hydrogenation of II is performed by reacting II in THF with H2 at 75°C and 50 bar for 5 hours in the presence of Pd / alumina, and then hydrogenation of the resulting product solution is completed at 100°C and 100 bar for 5 hours using a cobalt alloy containing cobalt: 75.9 wt%, aluminum: 20.0 wt%, chromium: 1.5 wt%, and nickel: 2.6 wt%, thereby obtaining 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine in 76% yield (European Patent Application Publication No. 3255035).

[0009] Furthermore, 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine is used as a curing agent in an epoxy resin composition comprising (a) an epoxy resin, (b) a crosslinking agent consisting of 0.1 to 100% by weight of 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine and 0 to 99.9% by weight of another diamine and / or polyamine, (c) 0.1 to 10% by weight of another crosslinking catalyst, (d) optionally one or more crosslinking precursors, and (e) optionally other additives (European Patent Application Publication No. 3255079).

[0010] Definitions Unless explicitly stated otherwise, terms used collectively in the present specification, including the appended claims, have the following meanings.

[0011] As used herein, the term "curable" means that the original compound or mixed material can be converted into a solid, substantially non-flowable material, for example, by chemical reaction, crosslinking, or crosslinking induced by radiation.

[0012] As used herein, the term "mixture" means a combination of two or more distinct chemically different compounds that are not physically or mechanically aggregated, or chemically bonded.

[0013] As used herein, the term "comonomer" means a compound that can undergo polymerization or copolymerization, thereby contributing structural units to the essential structure of a polymer.

[0014] As used herein, the term "comonomer component" means one comonomer or a mixture of two or more comonomers, preferably one comonomer or a mixture of 2 to 4 comonomers.

[0015] As used herein, the term “alkenylphenol” means an organic compound containing at least one alkenyl-substituted phenol group. The term “alkenylphenol” includes alkylphenols in which two phenol groups are crosslinked via a difunctional group, such as alkenylbisphenols. An example is 2,2'-diallylbisphenol A.

[0016] As used herein, the term “alkenylphenyl ether” means an organic compound containing at least one alkenyloxyphenyl group, i.e., an organic compound containing an ether group in which an ether oxygen atom is bonded to an alkenyl residue on one side and to a phenyl residue on the other. The term “alkenylphenyl ether” includes alkenylphenyl ethers in which two phenyl groups are crosslinked by a difunctional group, such as alkenylbisphenol ethers. An example is diallyl ether of bisphenol A.

[0017] As used herein, the term “alkenylphenol ether” means an organic compound containing at least one alkenylphenoxy group, for example, an organic compound containing an ether group in which an ether oxygen atom is bonded on one side to an alkenylphenyl group and on the other side to an alkyl or aryl group. The term “alkenylphenol ether” includes organic compounds in which two alkenylphenoxy groups are crosslinked by a difunctional group, such as an aromatic group such as a benzophenone group. An example is bis-(o-propenylphenoxy)benzophenone.

[0018] As used herein, the term "polyamine" means an organic compound having two or more primary amino groups -NH2. Examples include, but are not limited to, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, diaminodiphenylindan, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, m-xylylenediamine, and aliphatic diamines, such as ethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, and 1,12-diaminododecane.

[0019] As used herein, the term "aminophenol" refers to amino-substituted phenols. Examples include m-aminophenol and p-aminophenol.

[0020] As used herein, the term “amino acid hydrazide” means any hydrazide of an amino acid. Examples include m-aminobenzhydrazide and p-aminobenzhydrazide.

[0021] As used herein, the term "cyanate ester" refers to bisphenols or polyphenols, such as novolacs, derivatives, in which the hydrogen atom of the phenolic OH group is replaced with a cyano group to form a -OCN group. Examples include bisphenol A dicyanate esters, commercially available from Lonza as Primaset BADCy or Huntsman as AroCy B-10, as well as other Primaset or AroCy types, such as bis(3,5-dimethyl-4-cyanatophenyl)methane (AroCy M-10), 1,1-bis(4-cyanatophenyl)ethane (AroCy L-10), 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane (AroCy F-10), 1,3-bis(1-(4-cyanatophenyl)-1-methylethylidene)benzene (AroCy XU-366), and di(4-cyanatophenyl)thioether (AroCy RDX-80371; AroCy Examples include T-10), bis(4-cyanatophenyl)dichloromethylidenemethane (AroCy RD98-228), bis(4-cyanatophenyl)octahydro-4,7-methanoindene (AroCy XU-71787.02L), as well as bis(4-cyanatophenyl)methane, bis(3-methyl-4-cyanatophenyl)methane, bis(3-ethyl-4-cyanatophenyl)methane, di(4-cyanatophenyl) ether, 4,4-dicyanatobiphenyl, 1,4-bis(1-(4-cyanatophenyl)-1-methylethylidene)benzene, and resorcinol dicyanates. A preferred example is bisphenol A dicyanate ester.

[0022] Bonds enclosed in parentheses represent bonds that connect the part inside the parentheses to another part of the same compound. For example, the following group [ka] The two bonds of the ethenyl group enclosed in parentheses on the right connect this site to another site in the compound containing this ethenyl group.

[0023] As used herein, the term "halogen" means a fluorine, chlorine, bromine, or iodine atom, preferably a fluorine or chlorine atom, more preferably a fluorine atom.

[0024] As used herein, “alkyl” means a linear or branched alkyl group. The term “n-m carbon atom alkyl group” means an alkyl group having n-m carbon atoms. Unless otherwise stated, “alkyl” means an alkyl group having 1 to 6 carbon atoms. In relation to the present invention, preferred alkyl groups are linear or branched alkyl groups having up to 4 carbon atoms. Examples of linear and branched alkyl groups, but not limited to, include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, isomer pentyl, isomer hexyl, preferably methyl and ethyl, most preferably methyl.

[0025] As used herein, “alkylene” means a difunctional alkyl group. The term “n to m carbon atom alkylene” means an alkylene group having n to m carbon atoms. Unless otherwise specified, “alkylene” means an alkylene having 1 to 12 carbon atoms. In relation to the present invention, preferred alkylene groups are alkylene groups having 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms. Examples, but not limited to, include methylene, ethylene, propylene, butylene, hexamethylene, and 2,2,4-trimethylhexamethylene. Particularly preferred is 2,2,4-trimethylhexamethylene.

[0026] As used herein, "alkenylene" means a bifunctional alkenyl group. The term "alkenylene having n to m carbon atoms" means an alkenylene group having n to m carbon atoms. Unless otherwise stated, "alkenylene" means an alkenylene having 2 to 12 carbon atoms. In relation to the present invention, preferred alkenylene groups are those having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms. Examples, but not limited to, include etenylene, propenylene, and butenylene. Ethenylene is particularly preferred.

[0027] As used herein, “alkoxy” means a linear or branched alkyl group bonded to a compound via an oxygen atom (-O-). The term “alkoxy having n to m carbon atoms” means an alkoxy having n to m carbon atoms. Unless otherwise stated, “alkoxy” means a linear or branched alkoxy group having up to six carbon atoms. In relation to the present invention, preferred alkoxy groups are linear or branched alkoxy groups having up to four carbon atoms.

[0028] As used herein, “alkenyl” means a linear or branched hydrocarbon group containing a carbon-carbon double bond. The term “alkenyl having n to m carbon atoms” means an alkenyl having n to m carbon atoms. Unless otherwise stated, “alkenyl” means a linear or branched hydrocarbon group containing a carbon-carbon double bond at any desired position and containing 2 to 10 carbon atoms. In relation to the present invention, preferred alkenyl groups contain a carbon-carbon double bond at any desired position and contain 2 to 6, more preferably 2 to 4 carbon atoms. Examples of alkenyl groups, but not limited to, include ethenyl, 1-propenyl, 2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, and isobutenyl. Preferred examples are 1-propenyl and 2-propenyl.

[0029] As used herein, the term "monocyclic carbocyclic group" means "monocyclic carbocyclic aliphatic group" or "monocyclic carbocyclic aromatic group."

[0030] As used herein, the term "bicyclic carbocyclic group" means a "bicyclic carbocyclic aliphatic group" or a "bicyclic carbocyclic aromatic group."

[0031] As used herein, the term "monocyclic carbocyclic aliphatic group" means "cycloalkylene group".

[0032] In this specification, "cycloalkyl" means a monofunctional saturated carbocyclic system. The term "cycloalkyl having n to m carbon atoms" means a cycloalkyl having n to m carbon atoms. Preferably, cycloalkyl means a cycloalkyl having 5 to 6 carbon atoms. Examples of cycloalkyls include, but are not limited to, cyclopropanyl, cyclobutanyl, cyclopentanyl, cyclohexanyl, cycloheptanyl, or cyclooctanyl, with cyclopentanyl and cyclohexanyl being preferred.

[0033] In this specification, "cycloalkylene" means a bifunctional saturated carbocyclic system. The term "cycloalkylene having n to m carbon atoms" means a cycloalkylene having n to m carbon atoms. Unless otherwise specified, "cycloalkylene" means a cycloalkylene group having 3 to 8 carbon atoms. In relation to the present invention, preferred cycloalkylene groups are those having 5 to 7, more preferably 5 or 6 carbon atoms. Examples, but not limited to, include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, or cyclooctylene, preferably cyclopentylene and cyclohexylene.

[0034] In this specification, “bicyclic carbolic aliphatic group” means a bifunctional condensed, bridged, or fused bicyclic saturated ring system. Unless otherwise specified, “bicyclic carbolic aliphatic group” means a bifunctional condensed, bridged, or fused bicyclic saturated ring system having 9 to 20 carbon atoms. Examples include, but are not limited to, dekalinyl, hydrindanyl, and norbornyl.

[0035] As used herein, the term “monocyclic or bicyclic aromatic group” means a bifunctional monocyclic or bicyclic aromatic system having 6 to 12 carbon atoms, preferably a monocyclic aromatic system. Examples, but not limited to, include toluene, phenylene, naphthylene, tetrahydronaphthylene, indenylene, indanylene, pentanylene, and fluorenylene, with toluene, phenylene, or indanylene being preferred.

[0036] As used herein, the term "aryl" means a monofunctional monocyclic or bicyclic aromatic system having 6 to 12 carbon atoms, preferably a monocyclic aromatic system. Examples, but not limited to, include toluyl, phenyl, naphthyl, tetrahydronaphthyl, indenyl, indanyl, pentarenyl, and fluorenyl, with toluyl, phenyl, or indanyl being preferred.

[0037] As used herein, the term "heterocyclic group" means "heterocyclic aliphatic group" or "heterocyclic aromatic group."

[0038] As used herein, the term “heterocyclic aliphatic group” means a bifunctional saturated ring system containing one, two, or three atoms selected from nitrogen, oxygen, and / or sulfur in addition to carbon atoms. Preferred heterocyclic aliphatic groups are those containing three to five carbon atoms and one nitrogen, oxygen, or sulfur atom.

[0039] As used herein, the term “heterocyclic aromatic group” means a monocyclic aromatic five-membered or six-membered ring containing one, two, or three atoms selected from nitrogen, oxygen, and / or sulfur, or a bicyclic aromatic group containing two five-membered or six-membered rings in which one or both rings may contain one, two, or three atoms selected from nitrogen, oxygen, or sulfur. Examples include, but are not limited to, pyridyl, pyrazinyl, pyrimidinyl, pyridadinyl, oxazolyl, oxydiazolyl, isoxazolyl, thiadiazolyl, tetrazolyl, pyrazolyl, imidazolyl, thiazolyl, thienyl, quinolinyl, isoquinolinyl, synnolinyl, pyrazolo[1,5-a]pyridyl, imidazo[1,2-a]pyridyl, quinoxalinyl, benzothiazolyl, benzotriazolyl, indolyl, and indazolyl.

[0040] As used herein, the term "bridged polycyclic group" means a group consisting of at least two groups selected from monocyclic carbocyclic aromatic groups, bicyclic carbocyclic aromatic groups, and cycloalkylene groups, wherein these groups are linked to each other by direct carbon-carbon bonds or divalent groups.

[0041] Preferred divalent groups are oxy groups, thio groups, alkylene groups having 1 to 3 carbon atoms, sulfone groups, methanone groups, and the following groups: [ka] [In the formula, R 23 ~R 28 These are independently selected from alkyl groups having 1 to 6 carbon atoms. R 29 and R 30 [These are independently selected from alkylene groups having 1 to 6 carbon atoms.] That is the case.

[0042] In one embodiment, the term "bridged polycyclic group" refers to a group formed by a direct carbon-carbon bond, or via an oxy group, a thio group, an alkylene group having 1 to 3 carbon atoms, a sulfone group, a methanone group, or a group selected from the following:

Chemical Formula

[0043] In one embodiment, the term "bridged polycyclic group" refers to a group formed by a direct carbon-carbon bond, or via an oxy group, a thio group, an alkylene group having 1 to 3 carbon atoms, a sulfone group, a methanone group, or a group selected from the following:

Chemical Formula

[0044] In one embodiment, the term "bridged polycyclic group" refers to a group consisting of two phenylene groups connected to each other by a direct carbon-carbon bond or via a divalent group such as an oxy group, a thio group, an alkylene group having 1 to 3 carbon atoms, a sulfone group, or a methanone group.

[0045] As used herein, the terms “unsubstituted” or “substituted” mean that each group is either unsubstituted or has 1 to 4 substituents selected from alkyl, alkoxy, and halogen groups. Preferred substituents are methyl or ethyl.

[0046] As used herein, the terms “x functional group,” “y functional group,” “y' functional group,” and “y'' functional group” refer to groups that are bonded to the remainder of the compound via x, y, y', or y'' bonds, respectively. Preferably, the “x functional group,” “y functional group,” “y' functional group,” and “y'' functional group” are difunctional groups; that is, x, y, y', and y'' are preferably 2.

[0047] As used herein, the term “difunctional group” refers to a group that is bonded to the remainder of a compound via two bonds. Examples of difunctional groups include, but are not limited to, difunctional aliphatic groups and difunctional aromatic groups. Examples of difunctional aliphatic groups include, but are not limited to, the following groups: [ka] These are some examples.

[0048] The following are examples of difunctional aromatic groups, though not limited to them: [ka] These are some examples.

[0049] Further difunctional groups include, but are not limited to, the following: [ka] These are some examples.

[0050] As used herein, the term “glass transition temperature” or “Tg” refers to the temperature at which an amorphous solid, such as a polymer, undergoes a reversible transition between a highly elastic state and a glassy (vitreous) state, when the polymer becomes brittle when cooled and soft when heated. More specifically, it defines a pseudo-secondary phase transition, which occurs when a supercooled molten material is cooled, resulting in a glassy structure and properties similar to those of a crystalline material, such as an isotropic solid material.

[0051] The solubility of the compound in this invention is determined as follows: Weigh 10 g of sample into a 100 ml Erlenmeyer flask. Add 50 ml of solvent to the flask and stir the mixture with a magnetic stirrer at 25°C for 1 hour to ensure a saturated solution is formed. If the entire sample is dissolved, add the additional sample and stir the mixture for another hour. Finally, some undissolved material should be clearly visible at the bottom of the flask. Filter the supernatant through a folded filter. Weigh approximately 15 g of the filtrate into a tare-weighted round-bottom flask and evaporate the solvent to dryness using a rotary evaporator at 90°C under reduced pressure. Finally, dry the flask in a vacuum drying cabinet at 120°C under reduced pressure for 2 hours, cool to room temperature in a desiccator, and weigh it.

[0052] Subsequently, the solubility value is calculated as follows: Solubility [%] = ([Output weight] × 100) / [Original sample weight]

[0053] The bismaleimide according to the present invention In the first aspect, the present invention relates to formula (I) [ka] [In the formula, R is a substituted or unsubstituted C 3~7 Alicyclic ring, preferably C 5~6 Alicyclic ring, or Formula (II) [ka] [In the formula, R 1 and R 2 They may be the same or they may be different, C 1~12 Preferably C 3~6 [Independently selected from alkyl or alkenyl groups] [It is the basis of] This relates to bismaleimide by a preferred embodiment, C 3~7 A alicyclic ring consists of 1 to 5 carbon atoms. 1~4 It is substituted with an alkyl group.

[0054] In a preferred embodiment, R of bismaleimide in formula (I) is equal to R of formula (III) [ka] [In the formula, R 3 ~R 6 They may be the same or different, H or C 1~3 [Selected independently of alkyl groups] It is a cyclohexyl group.

[0055] In a preferred embodiment, bismaleimide is of formula (IV) [ka] It is a 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide having [a specific compound].

[0056] Curable composition according to the present invention In a second aspect, the present invention is (i) at least one bismaleimide according to the present invention; (ii) General formula (V) [ka] [In the formula, B is a difunctional group containing a carbon-carbon double bond, A is a y-functional group, y is an integer greater than or equal to 2. At least one type of polyimide, (iii) at least one comonomer or a combination of at least two comonomers, (a) Equation (VI) [ka] [In the formula, R 7 It is a difunctional group, R 8 and R 9 These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (b) Formula (VII) [ka] [In the formula, R 10 It is a difunctional group, R 11 and R 12 These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (c) Formula (VIII) [ka] [In the formula, R 13 It is a difunctional group, R 14 and R 15 These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (d) Formula (IX) [ka] [In the formula, R 16 It is a difunctional group, R 17 and R 18These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (e) Formula (X) [ka] [In the formula, R 19 is a y' functional group, R 20 This is an alkenyl group having 2 to 6 carbon atoms. y' is an integer greater than or equal to 2. The compound, (f) Formula (XI) [ka] [In the formula, R 21 is a y'' functional group, R 22 This is an alkenyl group having 2 to 6 carbon atoms. y'' is an integer greater than or equal to 2. compounds A combination of at least one comonomer or at least two comonomers selected from This relates to a curable composition containing [a specific compound].

[0057] In a preferred embodiment, B in the polyimide of formula (V) is the following difunctional group: [ka] Selected from.

[0058] In one preferred embodiment, A in the polyimide of formula (V) is the following difunctional group: a) an alkylene group having 2 to 12 carbon atoms, b) A cycloalkylene group having 5 to 6 carbon atoms, c) A heterocyclic group having 4 to 5 carbon atoms and at least one nitrogen, oxygen, or sulfur atom in the ring, d) Monocyclic or bicyclic carbon rings, e) A bridging polycyclic group comprising at least two groups selected from monocyclic carbocyclic aromatic groups, bicyclic carbocyclic aromatic groups, and cycloalkylene groups, wherein the linkage is by direct carbon-carbon bonding, or by a divalent group, preferably an oxy group, a thio group, an alkylene group having 1 to 3 carbon atoms, a sulfone group, a methanone group, or the following groups: [ka] [In the formula, R 23 ~R 28 These are independently selected from alkyl groups having 1 to 6 carbon atoms. R 29 and R 30 [These are independently selected from alkylene groups having 1 to 6 carbon atoms.] A bridged polycyclic group linked to each other by a divalent group selected from one of the following, f) Formula (XII) [ka] [In the formula, R 31 The following is based on [ka] It is one of them. The base defined by Selected from.

[0059] In one preferred embodiment, the polyimide of formula (V) is of formula (Va) [ka] [In the formula, R 32 The following is based on [ka] It is one of them, and B is as defined in equation (V). It is a bisimide.

[0060] In a preferred embodiment, at least one polyimide of formula (V) is 4,4'-bismaleimidodiphenylmethane, bis(3-methyl-5-ethyl-4-maleimidophenyl)methane, bis(3,5-dimethyl-4-maleimidophenyl)methane, 4,4'-bismaleimidodiphenyl ether, 4,4'-bismaleimidodiphenylsulfone, 3,3'-bismaleimidodiphenylsulfone, bismaleimidodiphenylindan, 2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene, 1,3-bismaleimidobenzene, 1,2-bismaleim The bismaleimide is selected from dobenzene, 1,4-bismaleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, 1,6-bismaleimido-(2,4,4-trimethyl)hexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,3-bis(maleimidomethyl)cyclohexane, 1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene, 1,4-bis(maleimidomethyl)benzene, or a mixture thereof.

[0061] In a preferred embodiment, the bismaleimide of formula (I) is 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide, and the polyimide according to formula (V) is 4,4'-bismaleimidediphenylmethane, bis(3-methyl-5-ethyl-4-maleimimidephenyl)methane, bis(3,5-dimethyl-4-maleimimidephenyl)methane, 4,4'-bismaleimidediphenyl ether, 4,4'-bismaleimidediphenylsulfone, 3,3'-bismaleimidediphenylsulfone, bismaleimidediphenylindan, 2,4-bismaleimidetoluene, 2,6-bismaleimide Selected from reimidotoluene, 1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene, 1,4-bismaleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, 1,6-bismaleimido-(2,4,4-trimethyl)hexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,3-bis(maleimidomethyl)cyclohexane, 1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene, and 1,4-bis(maleimidomethyl)benzene.

[0062] In one embodiment, the curable composition further comprises one or more curing inhibitors. The curing inhibitors slow down the polymerization reaction, thereby altering the processability and storage stability of the composition and intermediate products, such as prepregs, molding compounds, and resin solutions. Suitable curing inhibitors include hydroquinone, 1,4-naphthoquinone, ionol, and phenothiazine, which are used at concentrations of 0.1% to 2.0% by weight based on the total weight of the composition. It is advantageous to dissolve the inhibitor in one of the components before preparing the mixture.

[0063] In one embodiment, the curable composition further comprises one or more curing accelerators. The curing accelerators accelerate the curing process. Typically, the curing accelerator is added in an amount of 0.01% to 5% by weight, preferably 0.1% to 2% by weight, based on the total weight of the curable composition. Suitable curing accelerators include ionic polymerization catalysts and free radical polymerization catalysts. Examples of free radical polymerization catalysts include (a) organic peroxides such as di-tert-butyl peroxide, diamyl peroxide, and t-butyl perbenzoate, and (b) azo compounds such as azobisisobutyronitrile. Examples of ionic catalysts include alkali metal compounds, tertiary amines such as triethylamine, dimethylbenzylamine, dimethylaniline, azabicyclooctane, heterocyclic amines such as quinoline, N-methylmorpholine, methylimidazole, and phenylimidazole, and phosphorus compounds such as triphenylphosphine and quaternary phosphonium halides. The curing accelerator can be mixed with the components of the curable composition by either a powder blending process or a solvent blending process.

[0064] The curable composition may further comprise at least one comonomer. In one embodiment, the at least one comonomer is selected from 2,2'-diallylbisphenol-A, bisphenol-A diallyl ether, bis(o-propenylphenoxy)benzophenone, m-aminobenzhydrazide, bisphenol-A dicyanate ester, diallyl phthalate, triallyl isocyanurate, triallyl cyanurate, styrene, divinylbenzene, or a mixture thereof.

[0065] In one embodiment, at least one comonomer is selected from alkenylphenol, alkenylphenyl ether, alkenylphenol ether, polyamine, aminophenol, amino acid hydrazide, cyanate ester, diallyl phthalate, triallyl isocyanurate, triallyl cyanurate, styrene, and divinylbenzene, and this comonomer is preferably present in an amount of 1% to 30% by weight based on the total weight of the composition.

[0066] In one embodiment, the molar ratio between unsaturated imide groups and reactive alkenyl groups in the curable composition is in the range of 1.0 to 0.1, for example, 1.0 to 0.2, 1.0 to 0.3, 1.0 to 0.4, 1.0 to 0.5, 1.0 to 0.6, 1.0 to 0.7, or 1.0 to 0.8. These ranges allow for a desirable curing rate.

[0067] In one embodiment, the curable composition further comprises at least one reaction inhibitor. The reaction inhibitor improves the processability before use and storage stability. Suitable reaction inhibitors include hydroquinone, 1,4-naphthoquinone, and phenothiazine, which can be used at a concentration of 0.1% to 2.0% by weight based on the total weight of the composition. It is advantageous to dissolve the inhibitor in one of the components before preparing the composition.

[0068] In one embodiment, the curable composition further comprises at least one reaction modifier selected from alkenylphenols, alkenylphenyl ethers, alkenylphenol ethers, polyamines, aminophenols, amino acid hydrazides, cyanate esters, diallyl phthalates, triallyl isocyanurates, triallyl cyanurates, styrene, divinylbenzene, or mixtures thereof. The reaction modifier may be present in an amount of 1% to 30% by weight based on the total weight of the composition. Among these, allyl-type components such as diallylbisphenol A, bisphenol A diallyl ether, diallyl phthalate, triallyl isocyanurate, and triallyl cyanurate are preferred. These can slow down the polymerization rate and thus widen the processing window. Reaction modifiers such as styrene and divinylbenzene are very effective at concentrations of 10% to 20% by weight, but they accelerate the polymerization rate, speed up the curing of the resin, and lower the polymerization temperature. Therefore, reaction modifiers are additional means for modifying the curing rate of the curable composition of the present invention. When such a reaction modifier is used, it is advantageous to first blend the bismaleimide according to the present invention with the reaction modifier in the required proportion, and then, in a second step, dissolve the polyimide portion of the mixture in this blend, if necessary, at a high temperature.

[0069] In one embodiment, the curable composition of the present invention may further contain, based on the total weight of the composition, at least one thermoplastic polymer in an amount of 0.01% to about 30% by weight, such as polyaryl ethers, polyaryl sulfones, polyarylates, polyamides, polyaryl ketones, polyimides different from formula (V), polyimide ethers, polyolefins, ABS resins, polydienes or diene copolymers, or mixtures thereof. Thermoplastic resins such as polysulfones and phenoxy resins are particularly miscible with the curable composition of the present invention and can be used to adjust the viscosity of the resin and to control the flow during curing. Thermoplastic polymers may also be added to improve fracture toughness. Thermoplastic polymers can be added to the curable composition as a fine powder or dissolved in either bismaleimide according to formula (I) or a reaction modifier.

[0070] In one embodiment, the curable composition may contain at least one catalyst. The catalyst may be present in an amount of 0.01% to 5% by weight, preferably 0.1% to 2% by weight, based on the total weight of the curable composition. Suitable catalysts include ionic polymerization catalysts and free radical polymerization catalysts. Examples of free radical polymerization catalysts include (a) organic peroxides such as di-tert-butyl peroxide, diamyl peroxide, and t-butyl perbenzoate, and (b) azo compounds such as azobisisobutyronitrile. Examples of ionic catalysts include alkali metal compounds, tertiary amines such as triethylamine, dimethylbenzylamine, dimethylaniline, azabicyclooctane, heterocyclic amines such as quinoline, N-methylmorpholine, methylimidazole, and phenylimidazole, and phosphorus compounds such as triphenylphosphine and quaternary phosphonium halides. The catalyst may be mixed with the components of the curable composition or added during processing by either the powder blending process or the solvent blending process described later.

[0071] Method for producing a curable composition according to the present invention In a third aspect, the present invention relates to a method for producing a curable composition according to the present invention, comprising the step of blending at least one polyimide and at least one bismaleimide using a powder blending process, a melt blending process, or a solvent-assisted blending process to obtain a curable composition. The curable composition may be a solid, low-melting-point, tacky, or liquid curable composition.

[0072] Solvent blending process In one embodiment, a method for producing the curable composition of the present invention is a solvent blending process, comprising the step of dissolving the components of the curable composition in a solvent or diluent to obtain a stable solution that can be further processed into a prepreg. Alternatively, the solvent or diluent can be subsequently removed to obtain the curable composition as a solvent-free mass (resin), which can then be used in a variety of hot-melt processing techniques.

[0073] In one embodiment, the dissolution process is carried out at a temperature above 30°C.

[0074] Suitable solvents and diluents are all conventional inert organic solvents. These include, but are not limited to, ketones such as acetone, methyl ethyl ketone, and cyclohexanone; glycol ethers such as methyl glycol, methyl glycol acetate, propylene glycol monomethyl ether (methyl proxitol), methyl proxitol acetate, diethylene glycol, and diethylene glycol monomethyl ether; toluene and xylene, preferably combinations thereof with 1,3-dioxolane as a cosolvent.

[0075] In one embodiment, the solvent mixture contains up to 50% by weight, preferably up to 40% by weight, of ketones, such as acetone, methyl ethyl ketone, cyclohexanone, or glycol ethers, such as ethylene glycol ether, propylene glycol ether, butylene glycol ether, and their acetate esters, based on the total weight of the solvent mixture.

[0076] In one embodiment, the solution of the curable composition of the present invention contains 30% to 70% by weight, preferably 40% to 60% by weight, of a solvent, such as a solvent for 1,3-dioxolane, or a solvent mixture containing 1,3-dioxolane and the above solvent. Such concentrations are typically used in industrial dip coating processes.

[0077] Melt Blending Process In one embodiment, the method for producing the curable composition of the present invention is a melt blending process. In one embodiment, the melt blending is carried out at a temperature of 70°C to 250°C. In a preferred embodiment, this method is carried out at a temperature of 90°C to 170°C, more preferably 100°C to 150°C. The curable composition is obtained as a low melting point mass (resin).

[0078] Crosslinked polymer of curable composition according to the present invention In a further embodiment, the present invention relates to a crosslinked polymer obtained from a curable composition by heating the curable composition according to the present invention to a temperature in the range of 70°C to 280°C.

[0079] The curable composition of the present invention has been found to be useful in the preparation of crosslinked polymers.

[0080] In one embodiment, heating is performed at a temperature of 90°C to 260°C, preferably 100°C to 250°C.

[0081] Composite material and method for producing the same according to the present invention The curable composition of the present invention has been found to be useful in the preparation of composite materials.

[0082] In a further embodiment, the present invention relates to a method for producing a composite material, comprising the steps of: mixing a curable composition or a crosslinked polymer according to the present invention with a fibrous or particulate reinforcing material; and curing the mixture.

[0083] In the final aspect, the present invention relates to a composite material obtained by a method according to the present invention.

[0084] In one embodiment, the curing process can be carried out by simultaneous molding under pressure to obtain a molded product, a laminate, an adhesive, and a foam.

[0085] In one embodiment, a curable composition or a crosslinked polymer containing fibrous or particulate reinforcing material can be processed by known methods of the powder molding industry for producing molded articles, with curing occurring along with co-molding under pressure. For these applications, the curable composition is mixed with fibrous or particulate reinforcing material (hereinafter also called filler), as well as optionally colorants and flame retardants. Ideal fillers include, for example, glass short fibers, carbon short fibers, or aramid short fibers, and particulate fillers such as quartz, silica, ceramics, metal powders, and carbon powders. Depending on the technical application of the molded article, two or more different fillers may be used simultaneously.

[0086] Purpose In one embodiment, the composite material is a fiber composite material. For this application, a filler, particularly fibers such as glass, carbon, or aramid in the form of roving, fabric, short fiber mat, or felt, is impregnated with the curable composition using a solution of the curable composition for impregnating the reinforcing material. After the solvent has dried and been removed, a prepreg remains, which can be cured in a second step, optionally under pressure, at a temperature of 180°C to 350°C.

[0087] molten prepreg In one embodiment, the composite material is a fiber-reinforced composite material obtained by a hot-melt process. To obtain such a fiber-reinforced composite material, a curable composition is processed as a hot melt into a resin film on a carrier foil, and then a filler, such as fibers in the form of roving or fabric, is injected into the molten resin film to form a prepreg. In this process, a low-temperature, low-viscosity curable composition is advantageous in order to sufficiently impregnate the fiber roving or fabric.

[0088] Laminate In one embodiment, the composite material is a fiber laminate. Prepregs, manufactured from glass fibers, carbon fibers, or aramid fibers in the form of fabric or roving by either a solvent / solution process or a hot melt process, are stacked to form a prepreg laminate, which is then cured under pressure or in a vacuum bag at a temperature of 150°C to 280°C, preferably 170°C to 260°C.

[0089] In one embodiment, the curable composition defined above is mixed with fibrous or particulate reinforcing materials (fillers) using standard processing techniques, such as hot melt or solution-based prepregation, resin transfer molding (RTM), resin injection molding (RIM), filament winding (FW), or compounding techniques, for example, by being coated on them or blended with them.

[0090] Curing can be carried out at a temperature in the range of 70°C to 280°C, preferably in the range of 80°C to 270°C, more preferably in the range of 90°C to 260°C, most preferably in the range of 100°C to 250°C, preferably for a sufficient amount of time to allow for complete curing.

[0091] In one embodiment, the composite material is a fiber-reinforced composite material. In another embodiment, the composite material is a particle-filled composite material.

[0092] In one embodiment, the present invention is a method for preparing a composite material, (a) A step of preparing the curable composition defined above, (b) A step of applying the curable composition defined above onto a fibrous reinforcing material or blending it with particulate filler, (c) A step of curing the curable composition defined above at a temperature in the range of 70°C to 280°C, preferably for a time sufficient to cure completely, and (d) A process of obtaining a composite material by simultaneously applying pressure, This includes methods.

[0093] Processing step c) can be carried out at a temperature in the range of 70°C to 280°C, preferably in the range of 80°C to 270°C, more preferably in the range of 90°C to 260°C, most preferably in the range of 100°C to 250°C, and preferably for a time sufficient to allow for complete curing.

[0094] In the implementation of processing step c), the conversion of the curable composition of the present invention to a crosslinked (cured) polymer can be carried out in the presence of the curing catalyst defined above.

[0095] In processing step d), molding is performed under pressure to obtain the composite material of the present invention. Processing steps c) and d) are preferably performed simultaneously.

[0096] A preferred application of the curable composition of the present invention is as a resin for fiber-reinforced composite materials. To obtain such a fiber-reinforced composite material, the curable composition of the present invention is processed as a hot melt into a resin film on a carrier foil, which is then used to prepare a prepolymer by press-fitting fibers in the form of roving or fabric into the resin film. In this process, a low-temperature, low-viscosity curable composition is advantageous for adequately impregnating the fiber roving or fabric.

[0097] In one embodiment, the composite material of the present invention is a fiber-reinforced laminate or a copper-clad laminate for use in printed circuit boards.

[0098] Examples The following examples are intended to illustrate the present invention, but are not intended to limit it.

[0099] Examples: A. Preparation of 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide Example 1 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide was prepared according to the following reaction scheme: [ka]

[0100] In a glass reactor equipped with a mechanical stirrer, thermometer, and dropping funnel, 120 ml of N,N-dimethylacetamide was added under nitrogen. 100 g of maleic anhydride was added, and the mixture was stirred until dissolution was complete. Next, 99.2 g of 2-(3,3,5-trimethylcyclohexyl)propane-1,3-diamine was added dropwise, ensuring the temperature did not exceed 60°C. After the addition, the mixture was stirred at 50-55°C for 1 hour. Next, 128 g of acetic anhydride was added, followed by 200 g of triethylamine. The reaction mixture was heated to 90°C, stirred for 1 hour, and then cooled to 60°C. Next, the mixture was stirred at 60°C for 20 minutes, and then poured into 2 liters of water with vigorous stirring. The precipitate was filtered off and washed by slurring in distilled water. Finally, the product was filtered off and dried under reduced pressure at 60°C. For analytical purposes, the product was purified by column chromatography using silica gel as the solid phase and methyl ethyl ketone as the eluent. Melting point: 119°C (DSC, 10°C / min). [ka]

[0101] The resulting 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide exhibits high solubility in various organic solvents compared to other aliphatic bismaleimides.

[0102] [Table 1]

[0103] The solubility of the examples and comparative examples was determined as follows: 10 g of the sample was weighed into a 100 ml Erlenmeyer flask. 50 ml of solvent was added to the flask, and the mixture was stirred using a magnetic stirrer at 25°C for 1 hour to ensure a saturated solution was formed. If the entire sample was dissolved, additional sample should be added, and the mixture should be stirred for another hour. Ultimately, some undissolved material should be clearly visible at the bottom of the flask. The supernatant was then filtered through a folded filter. Approximately 15 g of the filtrate was weighed into a round-bottom flask, and the solvent was evaporated to dryness under reduced pressure at 90°C using a rotary evaporator. Finally, the flask was dried under reduced pressure at 120°C for 2 hours in a vacuum drying cabinet, cooled to room temperature in a desiccator, and weighed.

[0104] Subsequently, the solubility value is calculated as follows: Solubility [%] = ([Output weight] × 100) / [Original sample weight]

[0105] B. Preparation of a curable mixture according to the present invention based on bismaleimide of formula (I), polymaleimide of formula (V), and a comonomer.

[0106] The curable mixture according to the present invention can be obtained by following the general process below: (a) Solvent-assisted process At least one polymaleimide of formula (V), at least one bismaleimide of formula (I), and, if necessary, at least one additional comonomer component, along with an organic solvent, preferably toluene or methylene chloride, are heated to 90–100°C in a 1:1 solid-to-solvent weight ratio until a clear solution is obtained. Subsequently, the solvent is removed under reduced pressure while simultaneously raising the temperature to 100–120°C. Finally, the mixture is degassed under reduced pressure of 20 hPa [15 mmHg] for 2–10 minutes to obtain a curable mixture. The resin / solvent ratio may vary depending on the solubility of the components. Other solvents or diluents described in this patent may also be used.

[0107] (b) Melting process At least one polymaleimide of formula (V), at least one bismaleimide of formula (I), and at least one additional comonomer component, if necessary, are melt-blended at a temperature range of 100–120°C until a homogeneous mixture is obtained. Subsequently, the resulting melt is further heated at the same temperature range for a time sufficient to obtain a stable melt. Finally, the melt is degassed under reduced pressure of 20 hPa [15 mmHg] for 2–10 minutes to obtain a curable mixture.

[0108] (c) Reactivity measurement (c.1) Differential scanning calorimetry (DSC) To characterize the curing rate of the curable composition of the present invention, differential scanning calorimetry (DSC) traces obtained at a specified heating rate (10°C / min) in a temperature range of 20 to 380°C are used. Maximum curing heat generation T MAX This represents the maximum heat dissipation temperature due to polymerization at a specified heating rate. The start of the exothermic peak growth is at the polymerization initiation temperature T. ONSET It represents T ONSET and T MAX The higher the value, the slower the resin hardens.

[0109] (c.2) Hot plate gel time Gel time, a standard measure of resin reactivity, is measured by placing 1 g of resin on a polished, electrically heated metal block that can be maintained at a temperature between 130°C and 230°C, and examining the molten sample after continuous stirring with a wooden rod, as described in ISO 8987:2005-12 and ASTM D4217-07 (2017) standards.

[0110] C. Curable polymaleimide / asymmetrically substituted bisalkenyl diphenyl ether mixture Example 2 A curable mixture comprising 60 wt% bismaleimide of formula (IV) and 40 wt% 2,2'-bis(3-allyl-4-hydroxyphenyl)propane, prepared by a solvent-assisted process (a) using toluene as a solvent. Gel time: 54 minutes Kinematic viscosity at 90°C: 487 mPa·s; 110°C: 122 mPa·s DSC polymerization initiation (T ONSET ): 150℃ DSC polymerization highest (T MAX ): 279℃

[0111] Example 3 A curable mixture comprising 35 wt% bismaleimide of formula (IV), 35 wt% metaxylylenebismaleimide, and 30 wt% 4,4'-bis(ortho-propenylphenoxy)benzophenone, prepared by a solvent-assisted process (a) using toluene as a solvent. Gel time: 48 minutes Kinematic viscosity at 90°C: 867 mPa·s; 110°C: 194 mPa·s DSC polymerization initiation (T ONSET ): 136℃ DSC polymerization highest (T MAX ): 253℃

[0112] Example 4 A curable mixture comprising 30% by weight of bismaleimide of formula (IV) prepared by a solvent-assisted process (a) using toluene as a solvent, 30% by weight of 4,4'-bismaleimidediphenylmethane, 26.7% by weight of 4,4'-bis(ortho-propenylphenoxy)benzophenone, and 13.3% by weight of 2,2'-bis(3-allyl-4-hydroxyphenyl)propane. Gel time: 27 minutes Kinematic viscosity at 90°C: 2043 mPa·s; at 110°C: 3302 mPa·s DSC polymerization initiation (T ONSET ): 135℃ DSC polymerization highest (T MAX ): 260℃

[0113] Example 5 A mixture containing 21 g of bismaleimide of formula (IV), 9 g of 2,2'-bis(3-allyl-4-hydroxyphenyl)propane, and 30 g of methyl ethyl ketone was stirred at 60°C for 10 minutes, filtered, and cooled to room temperature to obtain a resin solution containing 50% by weight of solids. No crystallization was observed even after 6 weeks at room temperature. Gel time: 62 minutes Kinematic viscosity: 17mPa·s

Claims

1. Equation (I) 【Chemistry 1】 [In the formula, R is a substituted or unsubstituted cyclohexyl group. Bismaleimide by

2. R is given by equation (III) 【Transformation 3】 [In the formula, R ３ ~R ６ They may be the same or different, H or C １～３ Selected independently of alkyl groups, * indicates the bonding position with the carbon atom to which R is bonded. The bismaleimide according to claim 1, wherein the cyclohexyl group is...

3. The bismaleimide mentioned above is of formula (IV) 【Chemistry 4】 The bismaleimide according to claim 1, which is a 2-(3,3,5-trimethylcyclohexyl)propane-1,3-bismaleimide having the above.

4. (i) at least one bismaleimide according to claim 1 or 2, (ii) General formula (V) 【Transformation 5】 [In the formula, B is a difunctional group containing a carbon-carbon double bond, A is the base of y values, y is an integer greater than or equal to 2. At least one type of polyimide, (iii) at least one comonomer or a combination of at least two comonomers, (a) Equation (VI) 【Transformation 6】 [In the formula, R ７ It is a difunctional group, R ８ and R ９ These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (b) Formula (VII) 【Transformation 7】 [In the formula, R １０ It is a difunctional group, R １１ and R １２ may be the same or different, and are each independently selected from alkenyl groups having 2 to 6 carbon atoms] The compound, (c) Formula (VIII) 【Transformation 8】 [In the formula, R １３ It is a difunctional group, R １４ and R １５ These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (d) Formula (IX) 【Chemistry 9】 [In the formula, R １６ It is a difunctional group, R １７ and R １８ These may be the same or different, and are independently selected from alkenyl groups having 2 to 6 carbon atoms. The compound, (e) Formula (X) 【Chemistry 10】 [In the formula, R １９ is the base of the y' valence, R ２０ This is an alkenyl group having 2 to 6 carbon atoms. y' is an integer greater than or equal to 2. The compound, (f) Formula (XI) 【Chemistry 11】 [In the formula, R ２１ is the base of y'' values, R ２２ This is an alkenyl group having 2 to 6 carbon atoms. y'' is an integer greater than or equal to 2. compounds A combination of at least one comonomer or at least two comonomers selected from A curable composition containing the following:

5. The B in the polyimide of formula (V) is the following difunctional group: 【Chemistry 12】 A curable composition according to claim 4, selected from the following.

6. The A in the polyimide of formula (V) is the following difunctional group: a) an alkylene group having 2 to 12 carbon atoms, b) A cycloalkylene group having 5 to 6 carbon atoms, c) A heterocyclic group having 4 to 5 carbon atoms and at least one nitrogen, oxygen, or sulfur atom in the ring, d) Monocyclic or bicyclic carbon rings, e) A bridged polycyclic group comprising at least two groups selected from a monocyclic carbocyclic aromatic group, a bicyclic carbocyclic aromatic group, and a cycloalkylene group, wherein the bridged polycyclic groups are linked to each other by direct carbon-carbon bonds or by divalent groups. f) Formula (XII) 【Chemistry 13】 [In the formula, R ３１ The following is based 【Chemistry 14】 It is one of them. The base defined by A curable composition according to claim 4, selected from the following.

7. The polyimide of formula (V) is of formula (Va) 【Chemistry 15】 [In the formula, R ３２ The following is based 【Chemistry 16】 It is one of them. The curable composition according to claim 4, wherein the bisimide is...

8. The at least one polyimide of formula (V) is 4,4'-bismaleimidodiphenylmethane, bis(3-methyl-5-ethyl-4-maleimidophenyl)methane, bis(3,5-dimethyl-4-maleimidophenyl)methane, 4,4'-bismaleimidodiphenyl ether, 4,4'-bismaleimidodiphenylsulfone, 3,3'-bismaleimidodiphenylsulfone, bismaleimidodiphenylindan, 2,4-bismaleimidotoluene, 2,6-bismaleimidotoluene, 1,3-bismaleimidobenzene, 1,2-bismaleimidobenzene, 1,4-bis The curable composition according to claim 4, wherein the bismaleimide is selected from maleimidobenzene, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, 1,6-bismaleimido-(2,4,4-trimethyl)hexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,3-bis(maleimidomethyl)cyclohexane, 1,4-bismaleimidodicyclohexylmethane, 1,3-bis(maleimidomethyl)benzene, 1,4-bis(maleimidomethyl)benzene, or a mixture thereof.

9. A method for producing the curable composition according to claim 4, comprising the step of blending the at least one polyimide and the at least one bismaleimide using a powder blending process, a melt blending process, or a solvent-assisted blending process to obtain the curable composition.

10. A method for producing a crosslinked polymer, comprising heating the curable composition according to claim 4 to a temperature in the range of 70°C to 280°C.

11. A method for producing a composite material, comprising the steps of: mixing the curable composition according to claim 4 with a fibrous or particulate reinforcing material; and curing the mixture.

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