Phthalonitrile resins, methods for making them, and compositions thereof

Abstract

The present disclosure provides functionalized phthalonitrile monomers derived from a polyhydric phenol comprising at least one of a furan group or a thiophene group and 4-nitrophthalonitrile. The functionalized phthalonitrile monomers can be used in various thermosetting compositions, which can be cured to form thermosetting polymers with excellent thermal and mechanical properties, such as high thermal stability, heat resistance, high char yield, and structural rigidity.

Description

[Technical Field]

[0001] Relationship with related applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 928,466, filed October 31, 2019, the entire contents of which are expressly incorporated herein by reference.

[0002] Federal Research and Development Funding Commitments none

[0003] Field The present disclosure relates generally to novel phthalonitrile resins, methods for making such phthalonitrile resins, and their use in polymerizable thermoset compositions for applications in various industries, such as, but not limited to, building and construction, electronics packaging, energy and power production, aerospace, transportation, and medical device industries. [Background technology]

[0004] background Phthalonitrile monomers are a new class of high-performance monomers developed for high-temperature applications such as the production of prepregs, laminates, and structural composite parts. For example, U.S. Patents Nos. 5,629, 5,729, 5,800, 5,929, 5,930, 5,940, 5,950, 5,960, 5,970, 5,980, 5,990, 6,000, 6,000, 6,000, 7,000, 7,000, 8,000, 9,000, 10,000, 11,000, 12,000, 13,000, 14,000, 15,000, 16,000, 17,000, 18,000, 19,000, 20,000, 21,000, 22,000, 23,000, 24,000, 25,000, 26,000, 27,000, 28,000, 30,000, 31,000, 32,000, 33,000, 34,000, 35,000, 36,000, 37,000, 38,000, 40,000, 41,000, 42,000, 43,000, 44,000, 45,000, 46,000, 47,000, 48,000, 50,000, 51,000, 52,000, 53,000, 54

[0005] However, current phthalonitrile monomers are known to suffer from brittleness due to the rigidity of the monomer precursor and a high degree of cross-linking in the final cured product. In addition, such phthalonitrile monomers are generally solid at room temperature and therefore must be melted before use. Furthermore, complete curing can require higher than desirable cure temperatures (e.g., greater than 250°C) and longer times.

[0006] To overcome these drawbacks, attempts have been made to adjust the chain length between phthalonitrile monomer units to lower the melting point of the monomer and improve the flexibility of the cured product. Various catalysts have been used to improve the curing behavior of these phthalonitrile monomers. Finally, U.S. Patents 6, 751, 652 and 6, 753 disclose specific phthalonitrile monomers copolymerized with epoxy or benzoxazine resins to improve the processability, curing behavior, and final properties of the cured phthalonitrile products.

[0007] It would be desirable to further improve upon these state-of-the-art phthalonitrile monomers by developing new phthalonitrile monomers that can be used in polymerizable thermosetting compositions that exhibit even better processability and cure behavior and produce cured products with improved thermal and mechanical properties. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 6,420,464 [Patent Document 2] U.S. Patent No. 8,039,576 [Patent Document 3] U.S. Patent No. 8,853,343 [Patent Document 4] U.S. Patent No. 9,920,165 [Patent Document 5] US Patent Application Publication No. 2019 / 0047946 [Patent Document 6] U.S. Patent No. 5,939,508 [Patent Document 7] International Publication No. 2017105890 Brochure Summary of the Invention

[0009] The present disclosure generally provides functionalized phthalonitrile monomers obtained from the reaction of (i) a polyhydric phenol compound comprising at least one of a furan group or a thiophene group, and (ii) 4-nitrophthalonitrile.

[0010] According to another embodiment, there is provided a thermosetting composition comprising a functionalized phthalonitrile monomer and a curing agent. In yet another embodiment, the thermosetting composition can further comprise a second thermosetting resin comprising at least one of a vinyl, ethynyl, maleimide, imino, cyano, oxazine, or epoxy group, where the functionalized phthalonitrile monomer is the "first" thermosetting resin.

[0011] The thermosetting compositions of the present disclosure cure to thermoset compositions having improved thermal and mechanical properties. Chemical Policy Rimmer (Hereinafter, this may be referred to as "thermosetting polymer") Thus, thermosetting compositions may find use in a variety of applications, such as, but not limited to, the building and construction, electronics packaging, military, energy and power production, aerospace, transportation, and medical device industries. [Brief explanation of the drawings]

[0012] [Figure 1] LC-MS chromatogram of the compound produced in Example 2. [Figure 2] 1 is a GPC scan of the compound produced in Example 2. [Figure 3] 1 is a proton NMR of the compound produced in Example 2. [Figure 4] 13C-NMR of the compound produced in Example 2. [Figure 5]1 is a two-dimensional NMR of the proton-proton COSY spectrum of the compound produced in Example 2. [Figure 6] 1 is a two-dimensional NMR HSQC spectrum of the compound produced in Example 2. [Figure 7] 1 is a melting point measured by DSC of the compound produced in Example 2. [Figure 8] 1 is an FT-IR spectrum of the compound produced in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present disclosure generally provides functionalized phthalonitrile monomers obtained from the reaction of (i) a polyhydric phenol compound comprising at least one furan or thiophene group, and (ii) 4-nitrophthalonitrile. Surprisingly, the functionalized phthalonitrile monomers of the present disclosure have been found to offer several advantages over state-of-the-art phthalonitrile monomers. For example, the functionalized phthalonitrile monomers of the present disclosure contain furan / thiophene groups capable of homopolymerizing and crosslinking, and upon curing provide thermosets with improved thermal and mechanical properties, such as increased thermal stability, heat resistance, char yield, and enhanced structural rigidity. The functionalized phthalonitrile monomers of the present disclosure form a polymerization product. In addition, the functionalized phthalonitrile monomers of the present disclosure can react with other unsaturated thermosetting resins to further improve the processability, cure behavior, and properties of the final cured product. Thus, the functionalized phthalonitrile monomers of the present disclosure exhibit a superior balance of physical, mechanical, and thermal properties in the uncured and cured states compared to state-of-the-art phthalonitrile monomers.

[0014] The following terms shall have the following meanings:

[0015] The term "comprising" and its derivatives are not intended to exclude the presence of any additional component, step, or procedure, whether or not it is disclosed in the specification. For the avoidance of doubt, any composition claimed herein using the term "comprising" may include any additional additive or compound, unless stated to the contrary. In contrast, when the term "consisting essentially of" appears in the specification, this term indicates the exclusion of any other component, step, or procedure from the scope of the succeeding description (except those that are not essential to operability), and when the term "consisting of" is used, this term indicates the exclusion of any component, step, or procedure not expressly described or listed. The term "or" refers to the listed individual members as well as any combination of members, unless otherwise specified.

[0016] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. For example, "a functionalized phthalonitrile monomer" means one functionalized phthalonitrile monomer or more than one functionalized phthalonitrile monomer.

[0017] Phrases such as "in one aspect" and "according to one aspect" generally mean that the particular features, structures, and characteristics that follow the phrase are included in at least one aspect of the disclosure, and may be included in more than one aspect of the disclosure. Importantly, such phrases do not necessarily refer to the same aspect.

[0018] When the specification states that a feature may include or have an ingredient or function ("may," "can," "could," or "might"), it does not require that the particular ingredient or function be included or have that feature.

[0019] According to one aspect, the present disclosure provides a functionalized phthalonitrile monomer obtained from the reaction of (i) a polyhydric phenol compound comprising at least one of a furan group or a thiophene group, and (ii) 4-nitrophthalonitrile.

[0020] The polyhydric phenol compound comprising at least one of a furan group and a thiophene group is prepared by mixing a phenol compound and a compound represented by formula (1) [ka] wherein X is oxygen or sulfur, and Q is hydrogen or a C1-C5 alkyl group; and j is an integer between 1 and 3 Such compounds of formula (1) include, but are not limited to, furfural, 3-furaldehyde, 5-methylfurfural, 5-ethylfurfural, 2-thiophene-carboxaldehyde, 3-thiophene-carboxaldehyde, 3-methyl-2-thiophene-carboxaldehyde, and the like.

[0021] Phenolic compounds include, but are not limited to, phenol, cresol, xylenol (dimethylphenol), e.g., 2,6-xylenol, trimethylphenol, 2,5-alkylphenols, e.g., 2-tert-butyl-5-methyl-phenol or 2-tert-butyl-4-methylphenol, allylphenol, alkynylphenol, octylphenol, phenylphenol, diphenylphenol, guaiacol, hydroquinone, resorcinol, catechol, naphthol, dihydroxynaphthalene, methylnaphthol, bisphenol A, bisphenol F, and the like.

[0022] The compounds of formula (1) and phenolic compounds are not limited to those specifically mentioned above. Furthermore, each compound of formula (1) and phenolic compound can be used alone or as a mixture of two or more compounds.

[0023] Polyhydric phenol compounds comprising at least one furan or thiophene group can be prepared by methods commonly known to those skilled in the art. For example, the phenolic compound can be prepared by condensing a compound of formula (1) in the presence of a base and, optionally, an alcohol or a mono-substituted benzene at a temperature between about 30°C and about 150°C, or between about 60°C and about 90°C. Generally, the amount of the phenolic compound and the compound of formula (1) present during the condensation can range from about 1.5 moles to about 20 moles of the phenolic compound per mole of the compound of formula (1). In some embodiments, the amount of the phenolic compound relative to the compound of formula (1) present during the condensation can range from about 1.8 moles to about 10 moles per mole of the compound of formula (1).

[0024] Examples of bases that can be used include, but are not limited to, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, and potassium tert-butoxide; and alkaline earth alkoxides such as magnesium methoxide and magnesium ethoxide. These bases can be used alone or in combination of two or more. These bases can be used in an amount of about 0.005 to about 2.0 moles per mole of phenolic compound, or about 0.01 to about 1.1 moles per mole of phenolic compound.

[0025] Alcohol or mono-substituted benzene solvents that can be used include, but are not limited to, methanol, ethanol, propanol, isopropanol, toluene, xylene, etc. These can be used alone or in mixtures. If necessary, such solvents can be used in an amount of between about 5 parts by weight and about 500 parts by weight per 100 parts by weight of the phenolic compound, or in an amount of between about 10 parts by weight and about 300 parts by weight per 100 parts by weight of the phenolic compound.

[0026] The reaction can be carried out by adding a base to a mixture of the phenolic compound and the compound of formula (1) (and optionally an alcohol or mono-substituted benzene solvent) and heating the resulting mixture. Alternatively, the compound of formula (1) can be added to a mixture of the phenolic compound and the base (and optionally an alcohol or mono-substituted benzene solvent) under heating. The reaction time can range from about 5 hours to about 100 hours. Once the reaction is complete, the reaction mixture can be neutralized. Any unreacted material can then be removed by filtration or by heating under vacuum.

[0027] According to one embodiment, the polyhydric phenol compound comprising at least one furan or thiophene group is a compound selected from formulas (2) to (10). [ka] wherein n is an integer from about 3 to about 3.2.

[0028] In yet another embodiment, the polyhydric phenol compound comprising at least one furan group or thiophene group is derived from a compound of formula (1) where bisphenol A or bisphenol F and X is oxygen, and Q and j are as defined above.

[0029] A polyhydric phenol compound comprising at least one furan or thiophene group is then reacted with 4-nitrophthalonitrile to form the functionalized phthalonitrile monomer of the present disclosure. It is done.

[0030] According to one embodiment, a polyhydric phenol compound comprising at least one furan or thiophene group is reacted with 4-nitrophthalonitrile in the presence of a catalyst and, optionally, a solvent. Examples of catalysts include, but are not limited to, the aforementioned bases, as well as alkali metal salts such as cesium carbonate, potassium carbonate, or sodium carbonate, organolithium reagents such as methyl or n-butyllithium, Grignard reagents, or any combination thereof. Examples of solvents that can be used include, but are not limited to, any polar or nonpolar solvent, such as acetone, acetonitrile, alcohol, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, n-methylpyrrolidone, dimethyl sulfoxide, hexamethylphosulfamide, or combinations thereof. In another embodiment, the solvent can be a solvent capable of forming an azeotrope with water, such as toluene or xylene. Surprisingly, such solvents can be used to aid in the removal of both water found in the compounds forming the reaction mixture (i.e., the polyhydric phenol compound comprising at least one furan or thiophene group, 4-nitrophthalonitrile, and base) and water formed during the reaction of the polyhydric phenol compound comprising at least one furan or thiophene group with 4-nitrophthalonitrile. The functionalized phthalonitrile can be purified by recrystallization from a mixture of solvent and water to increase the monomer content of the resulting product.

[0031] According to another embodiment, the polyhydric phenol compound comprising at least one furan group or thiophene group and the functionalized phthalonitrile monomer can be formed in the same reaction vessel to improve overall process time and efficiency. In such an embodiment, in a first step, the polyhydric phenol comprising at least one furan group or thiophene group is formed in the reaction vessel as described above. In a second step, 4-nitrophthalonitrile is added to the polyhydric phenol comprising at least one furan group or thiophene group in the reaction vessel to form the functionalized phthalonitrile monomer. The base, catalyst, and solvent used in the reaction in the first and second steps can be the same or different. In some embodiments, the solvent is toluene or xylene.

[0032] The functionalized phthalonitrile monomers of the present disclosure can be thermally cured to form thermoset polymers that exhibit an excellent balance of chemical, mechanical, and thermal properties. A curing agent can be used to speed up the thermoset formation. Thus, in another aspect, a thermosetting composition is provided comprising a functionalized phthalonitrile monomer and a curing agent.

[0033] The amount of functionalized phthalonitrile monomer present in the thermosetting composition can be at least about 1 wt%, at least about 5 wt%, or at least about 10 wt%, or at least about 20 wt%, or at least about 30 wt%, or at least about 40 wt%, or at least about 50 wt%, or at least about 60 wt%, or at least about 70 wt%, or at least about 80 wt%, or at least about 90 wt%, or at least about 99 wt%, based on the total weight of the thermosetting composition. In other embodiments, the amount of functionalized phthalonitrile monomer present in the thermosetting composition can be between about 1 wt% and about 99 wt%, or between about 5 wt% and about 90 wt%, or between about 10 wt% and about 80 wt%, or between about 20 wt% and about 70 wt%, or between about 30 wt% and about 60 wt%, based on the total weight of the thermosetting composition.

[0034] Curing agents that can be used include, but are not limited to, aromatic amines, primary amines, secondary amines, diamines, polyamines, amine-substituted phosphazenes, phenols, strong acids, organic acids, strong organic acids, inorganic acids, metals, metal salts, metal salt hydrates, metal compounds, halogen-containing aromatic amines, clays, and chemically modified clays. The use of clays or chemically modified clays can improve the mechanical and flammability properties of thermoset resins. General Chemical modification of clay involves the exchange of sodium ions with ammonium to form quaternary ammonium salts.

[0035] Specific curing agents include, but are not limited to, bis(4-(4-aminophenoxy)phenyl sulfone (p-BAPS), bis(4-(3-aminophenoxy)phenyl sulfone (m-BAPS), 1,4-bis(3-aminophenoxy)benzene (p-APB), 1,12-diaminododecane, diphenylamine, epoxy amine curing agent, 1,6-hexanediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, p-toluenesulfonic acid, cuprous iodide, cuprous bromide, 1,3-bis(3-aminophenoxy)benzene (m-APB), 3,3'-Dimethyl-4,4'-diaminodiphenyl sulfone, 3,3'-Diethoxy-4,4'-diaminodiphenyl sulfone, 3,3'-Dicarboxy-4,4'-diaminodiphenyl sulfone, 3,3'-Dihydroxy-4,4'-diaminodiphenyl sulfone, 3,3'-Disulfo-4,4'-diaminodiphenyl sulfone, 3,3'-Diaminobenzophenone, 4,4'-Diaminobenzophenone, 3,3'-Dimethyl-4,4'-diaminobenzophenone, 3,3'-Dimethoxy-4,4'-diaminobenzophenone, 3,3'-Dicarboxy -4,4'-Diaminobenzophenone, 3,3'-dihydroxy-4,4'-diaminobenzophenone, 3,3'-disulfo-4,4'-diaminobenzophenone, 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenylphenylphosphine oxide, bis(3-aminophenoxy-4'-phenyl)phenylphosphine oxide, methylenedianiline, hexakis(4-aminophenoxy)cyclotriphosphazene, 3,3'-dichloro-4,4'-diaminodiphenyl sulfone, 2,2'-bis(trifluoromethyl) Bis[4-(4-aminophenoxy)phenyl]2,2'-hexafluoropropane, 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane, 3,3'-dichloro-4,4'-diaminobenzophenone, 3,3'-dibromo-4,4'-diaminobenzophenone, aniline-2-sulfonic acid, 8-aniline-1-naphthalenesulfonic acid, benzenesulfonic acid, butylsulfonic acid, 10-camphorsulfonic acid, 2,5-Diaminobenzenesulfonic acid, 6-dimethylamino-4-hydroxy-2-naphthalenesulfonic acid, 5-dimethylamino-1-naphthalenesulfonic acid, 4-hydroxy-3-nitroso-1-naphthalenesulfonic acid tetrahydrate, 8-hydroxyquinoline-5-sulfonic acid, methylsulfonic acid, phenylboric acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 1,5-naphthalenedisulfonic acid, 2,6-naphthalenedisulfonic acid, 2,7-naphthalenedisulfonic acid, picrylsulfonic acid hydrate, 2-pyridineethanesulfonic acid, 4-pyridineethanesulfonic acid, 3-pyridinesulfonic acid, 2-pyridinylhydroxymethanesulfonic acid, sulfanilic acid, 2-sulfobenzoic acid hydrate, 5-sulfosalic acid Chilic acid hydrate, 2,4-xylene sulfonic acid, sulfonic acid-containing dyes, organic phosphorus-containing acids, phenylphosphinic acid, diphenylphosphinic acid, propylphosphonic acid, 1-aminoethylphosphonic acid, 4-aminophenylphosphonic acid, butylphosphonic acid, t-butylphosphonic acid, 2-carboxyethylphosphonic acid, 2-chloroethylphosphonic acid, dimethylphosphonic acid, ethylphosphonic acid, methylenediphosphonic acid, methylphosphonic acid, phosphonoacetic acid, bis(hydroxymethyl)phosphonic acid, chloromethylphosphonic acid, di-n-butylphosphonic acid, dichloromethylphosphonic acid, diphenyldithiophosphonic acid, 1,2-ethylenediphosphonic acid, n-hystaderylphosphonic acid acid), hydroxymethylphosphonic acid, n-octadecylphosphonic acid, n-octylphosphonic acid, phenylphosphonic acid, propylene diphosphonic acid, n-tetradecylphosphonic acid, concentrated sulfuric acid, phenylphosphonic acid, copper, iron, zinc, nickel, chromium, molybdenum, vanadium, beryllium, silver, mercury, tin, lead, antimony, calcium, barium, manganese, magnesium, cobalt, palladium, platinum, cuprous bromide, cuprous cyanide, cuprous ferricyanide, zinc chloride, zinc bromide, zinc iodide, zinc cyanide, zinc ferrocyanide, zinc acetate, , zinc sulfide, silver chloride, iron(II) chloride, iron(III) chloride, iron(II) ferricyanide, iron(II) chloroplatinate, iron(II) fluoride, iron(II) sulfate, cobaltous chloride, cobalt(II) sulfate, cobalt(II) cyanide, nickel(II) chloride, nickel(II) cyanide, nickel(II) sulfate, nickel(II) carbonate, stannic chloride, stannous chloride hydrate, stannous chloride dihydrate, aluminum nitrate hydrate, aluminum nitrate nonahydrate, triphenylphosphine oxide complex, montmorillonite, chemically modified montmorillonite, 4,4'-(1,3-phenylenedioxy)dianiline, 4,4'-(1,4-phenylenedioxy)dianiline, bis(4-(4-aminophenoxy)phenyl)sulfone, 4,4'-(4,4'-isopropyl) propylidenediphenyl-1,1'-diyldioxy)dianiline, 4,4'-(1,3-phenylenediisopropylidene)dianiline, 4,4'-(1,4-phenylenediisopropylidene)dianiline, 4,4'-(1,1'-biphenyl-4,4'-diyldioxy)dianiline, 4,4'-methylenedianiline, 4,4'-sulfonyldianiline, 4,4'-methylene-bis(2-methylaniline), 3,3'-methylenedianiline, 3,4'-methylenedianiline, 4,4'-oxydianiline, 4,4'-(isopropylidene)dianiline, 4,4'-(hexafluoroisopropylidene)dianiline, 4,4'-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline, 4,4'-diaminobenzophenone, compounds: [ka] and mixtures thereof.

[0036] The curing agent can be present in the thermosetting composition in an amount of at least about 0.5 wt%, or at least about 1 wt%, or at least about 2 wt%, or at least about 5 wt%, or at least about 10 wt%, or at least about 15 wt%, or even at least about 20 wt%, based on the total weight of the thermosetting composition. In other embodiments, the curing agent can be present in an amount less than about 40 wt%, or less than about 35 wt%, or less than about 30 wt%, or less than about 25 wt%, based on the total weight of the thermosetting composition. In still other embodiments, the curing agent can be present in an amount between about 0.25 wt% and about 45 wt%, or between about 1 wt% and about 40 wt%, based on the total weight of the thermosetting composition.

[0037] The thermosetting compositions may also include a second phthalonitrile monomer in addition to those disclosed herein, as well as optional additives to impart desirable structural and / or thermal properties, including, but not limited to, fillers such as carbon nanotubes, clays, carbon nanofibers, metal oxides, zinc oxide, diatomaceous earth, barium sulfate, talc, silica, calcium carbonate, calcium fluoride, and combinations thereof, colorants, and antioxidant stabilizers. The additives may include thermal decomposition stabilizers, light stabilizers, flow agents, bodying agents, matting agents, binders, foaming agents, fungicides, bactericides, surfactants, plasticizers, rubber toughening agents, and other additives known to those skilled in the art, which, when present, are added in amounts effective for their intended purpose.

[0038] The curing agent (and optionally other phthalonitrile monomers and / or additives) can be added to the functionalized phthalonitrile monomer in any desired order and mixed using conventional equipment such as a stirring vessel, stirring rod, ball mill, sample mixer, static mixer, or ribbon blended to form a thermosetting composition. The composition can then be cured to form a thermosetting polymer. As used herein, the term "cured" refers to the conversion of the thermosetting composition to an insoluble, infusible crosslinked product that can be simultaneously molded to provide a shaped article, such as a molded, pressure-formed, or laminate, or to provide a two-dimensional structure, such as a coating, enamel, or adhesive bond. Typical curing processes include ambient temperature curing to elevated temperature curing using any combination of heat, radiation, or energy sources. Additionally, curing can occur in one or more curing stages. Typical curing temperatures can range from about 50°C to about 500°C, e.g., from about 75°C to about 375°C, or from about 80°C to about 300°C, for a time sufficient to at least partially, substantially, or completely cure the composition, such as, for example, from 4 to 20 hours, or from 4 to 16 hours, or from 6 to 12 hours.

[0039] In yet another embodiment, the thermosetting composition can include a second thermosetting resin comprising at least one vinyl, ethynyl, maleimide, imino, cyano, oxazine, or epoxy group. Combining the functionalized phthalonitrile monomers of the present disclosure with such a second thermosetting resin provides a fast-curing matrix for the thermosetting composition that may exhibit lower viscosity and produce a thermosetting polymer with a wide range of improved properties after cure, such as higher heat resistance, improved mechanical performance, lower water absorption, flame retardancy, and high char generation.

[0040] Thus, in one particular embodiment, the functionalized phthalonitrile monomers of the present disclosure can be combined with a monofunctional benzoxazine or a multifunctional benzoxazine or a combination thereof, and optionally one or more curing agents, and optionally additives, or a second phthalonitrile monomer in addition to the functionalized phthalonitrile monomers of the present disclosure to form a thermosetting composition.

[0041] According to one embodiment, the monofunctional benzoxazine is an acetylene-bearing benzoxazine compound. Such acetylene-bearing benzoxazine compounds are described in WO 1999 / 18092, the contents of which are incorporated herein by reference. In particular, the acetylene-bearing benzoxazine compound can be prepared from the reaction of a monophenolic compound, an aldehyde, and a primary amine.

[0042] The phenolic compound can be a monophenolic compound, such as, but not limited to, phenol, cresol, 2-bromo-4-methylphenol, 2-allylphenol, 1,4-aminophenol, etc. In one particular embodiment, the phenolic compound is phenol.

[0043] Aldehyde compounds include, but are not limited to, formaldehyde, paraformaldehyde, polyoxymethylene, or compounds having the formula RaCHO, where Ra is C1-C 12 In one particular embodiment, the aldehyde compound is formaldehyde.

[0044] The primary amine can be an amine having 2 to 40 carbons, one or more carbon-to-carbon triple bond groups, and optionally containing an O, N, S, or halogen heteroatom. The intermediate between the nitrogen of the primary amine and the carbon-to-carbon triple bond group can be a C1-C6 alkyl group optionally substituted with an aromatic group having 6 to 12 carbons, or an aromatic group having 6 to 12 carbons optionally substituted with a C1-C6 alkyl group. The carbon-to-carbon triple bond group can be of the formula -C≡CRd, -CH2-C≡CR d , [ka] where Rd is hydrogen, a C1-C5 alkyl group optionally substituted with an aromatic group having 6 to 12 carbons, or an aromatic group having 6 to 12 carbons optionally substituted with a C1-C5 alkyl group. In one particular embodiment, the primary amine having one or more carbon-to-carbon triple bonds is 3-aminophenylacetylene.

[0045] According to another aspect, the polyfunctional benzoxazine has the formula [ka] wherein b is an integer ranging from 2 to 4; and each R is independently hydrogen, substituted or unsubstituted C-C 20 Alkyl groups, substituted or unsubstituted C2-C 20 Alkenyl groups, substituted or unsubstituted C6-C 20 Aryl groups, substituted or unsubstituted C2-C 20 Heteroaryl groups, substituted or unsubstituted C4-C 20 Carbocyclic groups, substituted or unsubstituted C2-C 20 a heterocyclic group, or a C3-C8 cycloalkyl group; each R1 is independently hydrogen, C1-C 20 Alkyl groups, C2-C 20 Alkenyl group, or C6-C 20 aryl group; and when b is 2, Z is a direct bond, a substituted or unsubstituted C-C 20Alkyl groups, substituted or unsubstituted C6-C 20 Aryl groups, substituted or unsubstituted C2-C 20 When Z is a heteroaryl group, O, S, S=O, O=S=O, or C=O, and b is 3 or 4, Z is a substituted or unsubstituted C-C 20 Alkyl groups, substituted or unsubstituted C6-C 20 Aryl groups, substituted or unsubstituted C2-C 20 Heteroaryl groups. Substituents include, but are not limited to, hydroxy, C1-C 20 Alkyl, C2-C 10 Alkoxy, mercapto, C3-C8 cycloalkyl, C6-C 14 Heterocyclic group, C6-C 14 Aryl, C6-C 14 Includes heteroaryl, halogen, cyano, nitro, nitrone, amino, amido, acyl, oxyacyl, carboxyl, carbamate, sulfonyl, sulfonamido, and sulfuryl.

[0046] According to one embodiment, the polyfunctional benzoxazine compound is a compound obtained from the reaction of a polyfunctional phenolic compound, an aldehyde, such as formaldehyde, and a primary amine.

[0047] Polyfunctional phenolic compounds include, but are not limited to, resorcinol, bisphenol A, The phenols may be bisphenol A, bisphenol F, bisphenol E, bisphenol S, 1,2,2,2-tetraphenolethane, thiodiphenol, phenolphthalein, dicyclopentadienyldiphenol, 1,8-hydroxyanthraquinone, 1,6-dihydroxynaphthalene, 2-2'-dihydroxyazobenzene, and 1,3,5-trihydroxybenzene.

[0048] The primary amine can be, but is not limited to, those primary amines having at least one carbon-to-carbon triple bond group described above, as well as aniline, o-, m-, and p-phenylenediamine, benzidine, 4,4'-diaminodiphenylmethane, cyclohexylamine, 1,4-diaminocyclohexyl, butylamine, methylamine, hexylamine, allylamine, furfurylamine, ethylenediamine, propylenediamine, and diaminodiphenylsulfone.

[0049] According to one embodiment, the thermosetting composition can include monofunctional or polyfunctional benzoxazine or a combination thereof, and functionalized phthalonitrile monomer in a total benzoxazine:functionalized phthalonitrile monomer weight ratio of between about 1:1 to about 10:0.1, or about 1.5:1 to about 10:1, or about 2:1 to about 10:1.

[0050] The thermosetting composition can be prepared by mixing, in any order, the phthalonitrile monomer functionalized with at least one of monofunctional or polyfunctional benzoxazine and optional curing agent, the functionalized phthalonitrile monomer of the present disclosure plus other phthalonitrile monomers, and additives using conventional equipment such as a stirring vessel, a stirring rod, a ball mill, a sample mixer, a static mixer, or by ribbon blending to form the thermosetting composition, which can then be cured as described above to form a thermosetting polymer.

[0051] In yet another aspect, a thermoset polymer is provided by contacting any suitable substrate with any one of the above-described thermosetting compositions and subjecting the substrate / thermosetting composition to heat, radiation, or a combination of energy sources to cure the substrate / thermosetting composition. In one aspect, the thermosetting compositions of the present disclosure can be used to bond one or more substrates together by contacting one or more surfaces of the like or dissimilar substrates to be bonded with the thermosetting composition under conditions sufficient to cure the thermosetting composition.

[0052] In another embodiment, the thermosetting compositions of the present disclosure can be cured to provide composite articles by techniques well known in the industry, such as pultrusion, injection, molding, encapsulation, or coating. Thus, the thermosetting compositions of the present disclosure can be used in methods to make composite articles such as castings, prepregs, bonded sheets, laminates, and metal-foil clad laminates.

[0053] The properties of composite articles can be tailored to specific applications by the addition of reinforcing fibers. Examples of reinforcing fibers include glass, quartz, carbon, alumina, ceramic, metal, aramid, natural fibers (e.g., flax, jute, sisal, hemp), paper, acrylic, and polyethylene fibers, and mixtures thereof. The reinforcing fibers can be in any of a variety of forms, such as strands or rovings formed from unidirectional parallel continuous or discontinuous fibers (short fibers), cloth such as woven fabrics or mats, braids, unidirectional, bidirectional, random, quasi-isotropic, or three-dimensionally dispersed mat-like materials, non-uniform lattice or mesh materials, and three-dimensional materials such as triaxial woven fabrics.

[0054] Thus, in another aspect, a process for producing a composite article is provided, comprising: a layer of reinforcing fibers; with a thermosetting composition to coat and / or impregnate the reinforcing fibers; and curing the coated and / or impregnated reinforcing fibers to form the composite article.

[0055] The coating and / or impregnation can be carried out by either a wet method or a hot melt method, in which the thermosetting composition is first dissolved in a solvent to reduce the viscosity, after which the coating and / or impregnation of the reinforcing fibers is carried out, and the solvent is evaporated using an oven or the like.

[0056] In the hot melt method, the coating and / or impregnation can be carried out by directly coating and / or impregnating the reinforcing fibers with the thermosetting composition, which may already be heated to reduce viscosity, or alternatively, a film coated with the thermosetting composition can first be produced on a release paper or the like, and the film can be placed on one or both sides of the reinforcing fibers, and the coating and / or impregnation can be carried out by applying heat and pressure.

[0057] In another aspect, a process for producing a composite article in an RTM system is provided, the process comprising the steps of: a) introducing a fiber matrix comprising reinforcing fibers into a mold; b) injecting a thermosetting composition into the mold; c) impregnating the fiber matrix with the thermosetting composition; and d) heating the resin-impregnated matrix for a period of time to produce an at least partially cured solid article; and optionally e) subjecting the partially cured solid article to additional heat.

[0058] In yet another embodiment, a process for forming a composite article with a VaRTM system is provided, the process comprising: a) introducing a fiber matrix comprising reinforcing fibers into a mold; b) injecting a thermosetting composition into the mold; c) reducing the pressure within the mold; d) maintaining the mold at about the reduced pressure; e) impregnating the fiber matrix with the thermosetting composition; f) heating the resin-impregnated matrix to produce an at least partially cured solid article; and optionally g) subjecting the at least partially cured solid article to additional heat.

[0059] In addition to RTM and VaRTM systems, thermosetting compositions can be used in other processes and systems for producing composite articles, including prepreg hot-pressing, sheet molding compounding, molding, casting, pultrusion, and filament winding.

[0060] In another aspect, the thermosetting composition provides a thermosetting polymer upon cure that has an excellent balance of physical, mechanical, and thermal properties. According to the present disclosure, the well-balanced thermosetting polymer properties can include at least two of: a glass transition temperature (Tg) greater than about 250° C., or greater than about 270° C., or greater than about 290° C.; a storage modulus greater than 3500 MPa, or greater than 3750 MPa, or greater than 4000 MPa; a viscosity at 75° C. less than 250 centipoise, or less than 200 centipoise, or less than 175 centipoise; and a char yield of at least 60%, or at least 65%, or at least 70%.

[0061] The thermosetting compositions and composite articles of the present disclosure can be used in a variety of applications, such as aerospace applications, where they can be used as primary structural materials (wings, tails, floor beams, etc.) for airplanes, secondary structural materials (flaps, ailerons, cowls, fairings, interior trim, etc.), rocket motor casings, for satellites or other moving objects, such as structural materials for cars, ships and passenger carriages, in drive shafts, fuel cells, leaf springs, wind turbine blades, pressurized vessels, flywheels, papermaking rollers and civil engineering, and building materials (roofing materials, cables, reinforcing rods, retrofitting materials).

[0062] Example [Example]

[0063] Synthesis of tetramethylbisphenolfuran [ka] To a 500 ml four-neck round-bottom flask equipped with a mechanical stirrer and reflux condenser, 61.08 grams of 2,6-xylenol and 32.04 grams of methanol were added. Then, 2 grams of sodium hydroxide was added and stirred to dissolve. The resulting mixture was heated to reflux, and 24.0 grams of furfural was added dropwise under reflux over a period of 2 hours. The mixture was then refluxed for an additional 15 hours and monitored by HPLC for complete conversion, after which the mixture was neutralized with 35 grams of 20% aqueous sodium dihydrogen phosphate. The precipitated crystals were collected by filtration, washed with a 1:1 methanol / water solution, and dried in a vacuum drying oven. 72.6 grams of tetramethylbisphenolfuran (90.8%) was produced. The product was found to be very pure by HPLC (99.7%). [Example]

[0064] Synthesis of tetramethylbisphenolfuranphthalonitrile [ka] A 1000-ml four-neck round-bottom flask equipped with a thermometer, a Dean-Stark trap with a condenser, and a nitrogen inlet was charged with tetramethylbisphenolfuran (32.2 grams, 0.1 mole) from Example 1, powdered K2CO3 (33.2 grams, 0.24 mole), toluene (100 mL), and N,N-dimethylformamide (DMF) (146.1 grams). The resulting mixture was degassed with nitrogen, and the mixture was heated to reflux at 140°C for 10-12 hours. The toluene was then removed by distillation, and the reaction mixture was cooled to 30°C. 4-Nitrophthalonitrile (35.3 grams, 0.204 mole) was then added in one portion, and the reaction mixture was heated to 80°C and monitored by HPLC for complete conversion. The mixture was then cooled to ambient temperature and poured into chilled deionized water, resulting in the formation of a solid. The precipitated crystals were collected by filtration, washed with deionized water until neutral, and then with a 1:1 methanol / water solution. The resulting dark yellow solid was dried under vacuum to yield 54.5 grams (95%) of functionalized phthalonitrile monomer product. The structure of this product was confirmed by LC-MS, GPC, NMR, and FT-IR. The LC-MS chromatogram in Figure 1, the GPC scan in Figure 2, the NMR in Figures 3-6, and the FT-IR spectrum in Figure 9 show the desired product. The melting point for tetramethylbisphenolfuranphthalonitrile was found to be 219.6°C, as shown in Figure 8, consistent with the tetramethylbisphenolfuranphthalonitrile product. [Example]

[0065] Functionalized Phthalonitrile Monomer / Benzoxazine To a 4-ounce glass jar, 20 grams of phenol 3-aminophenylacetylene benzoxazine was added. The jar was then placed in an oven at 80°C until the material melted. Then, with stirring, 6 grams of phthalonitrile (4,4'-(((furan-2-ylmethylene)bis(2,6-dimethyl-4,1-phenylene))bis(oxy))diphthalonitrile) was added to the jar. The resulting mixture was stirred occasionally until the added material dissolved in the molten benzoxazine. Approximately 14 grams of the mixture was then transferred to an aluminum pan. After degassing at 65°C, the mixture was staged cured at 120°C for 2 hours, 150°C for 2 hours, 180°C for 2 hours, and 200°C for 2 hours. DSC was measured on a fresh sample, and DMA and TGA were measured on half of the cured product. The other half of the cured product was post-cured at 250°C for an additional 3 hours. The cured product was subjected to DMA and TGA analysis, and the results are shown in Table 1 below. [Example]

[0066] Functionalized Phthalonitrile Monomer / Benzoxazine Twelve grams of phenol 3-aminophenylacetylene benzoxazine was added to a 4-ounce glass jar. The jar was then placed in an oven at 80°C until the material melted. Then, with stirring, 2.4 grams of phthalonitrile (4,4'-(((furan-2-ylmethylene)bis(2,6-dimethyl-4,1-phenylene))bis(oxy))diphthalonitrile) was added to the jar. The resulting mixture was stirred occasionally until the added material dissolved in the molten benzoxazine. Approximately 12.5 grams of the mixture was transferred to an aluminum pan. After degassing at 65°C, the mixture was step-cured at 120°C for 2 hours, 150°C for 2 hours, 180°C for 2 hours, and 200°C for 2 hours. DSC of a freshly prepared sample and DMA and TGA of one half of the cured product were measured. The other half of the cured product was further post-cured at 250°C for 3 hours, and the DMA and TGA of this cured product were also measured, the results of which are shown in Table 1 below. [Example]

[0067] Functionalized Phthalonitrile Monomer / Benzoxazine To a 4-ounce glass jar was added 10.8 grams of phenol 3-aminophenylacetylene benzoxazine. The jar was then placed in an oven at 80°C until the material melted. Then, with stirring, 5.38 grams of phthalonitrile (4,4'-(((furan-2-ylmethylene)bis(2,6-dimethyl-4,1-phenylene))bis(oxy))diphthalonitrile) was added to the jar. The resulting mixture was stirred occasionally until the added material dissolved in the molten benzoxazine. Approximately 12.5 grams of the mixture was transferred to an aluminum pan. After degassing at 65°C, the mixture was step-cured at 120°C for 2 hours, 150°C for 2 hours, 180°C for 2 hours, and 200°C for 2 hours. DSC of a freshly prepared sample and DMA and TGA of half of the cured product were measured. The other half of the cured product was further post-cured at 250°C for 3 hours, and the DMA and TGA of this cured product were also measured, the results of which are shown in Table 1 below. [Example]

[0068] Comparative Example In an aluminum pan, add 14 grams of slightly polymerized phenol 3-aminophenyl Acetylene benzoxazine was added. The aluminum pan was then placed in a vacuum oven at 80°C to melt and degass for 1 hour. After degassing, the material was step-cured at 120°C for 2 hours, 150°C for 2 hours, 180°C for 2 hours, and 200°C for 2 hours. DSC was measured on a freshly prepared sample, and DMA and TGA were measured on half of the cured product. The other half of the cured product was post-cured at 250°C for an additional 3 hours, and DMA and TGA were also measured on this cured product. The results are shown in Table 1 below. [Table 1]

[0069] While making and using various embodiments of the present invention have been described in detail above, it should be understood that the present invention provides many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely examples of specific ways to make and use the invention and do not limit the scope of the invention.

Claims

1. A functionalized phthalonitrile monomer obtained from the reaction of (i) a polyhydric phenol compound comprising at least one of a furan group or a thiophene group, and (ii) 4-nitrophthalonitrile, The polyhydric phenol compound is a phenol compound and a compound represented by the formula (1) 【Chemical 1】 where X is oxygen or sulfur, and Q is hydrogen or C 1 -C 5 is an alkyl group, and j is 3 It is derived from the compound the phenolic compound comprises phenol, cresol, xylenol (dimethylphenol), 2-tert-butyl-5-methyl-phenol, 2-tert-butyl-4-methylphenol, allylphenol, alkynylphenol, octylphenol, phenylphenol, diphenylphenol, guaiacol, hydroquinone, resorcinol, catechol, naphthol, dihydroxynaphthalene, methylnaphthol, bisphenol A, or bisphenol F; The polyhydric phenol compound containing at least one of a furan group and a thiophene group is represented by the formulas (2) to (10): 【Chemistry 2】 wherein n is an integer from 3 to 3.

2. Selected from: Functionalized phthalonitrile monomer.

2. A thermosetting composition comprising the functionalized phthalonitrile monomer of claim 1 and a curing agent.

3. 3. The thermosetting composition of claim 2, further comprising at least one second phthalonitrile monomer other than the functionalized phthalonitrile monomer of claim 1, and an additive.

4. at least one of vinyl, ethynyl, maleimide, imino, cyano, or epoxy groups 3. The thermosetting composition of claim 2, further comprising a thermosetting resin comprising:

5. 10. The functionalized phthalonitrile monomer of claim 1; a thermosetting resin selected from monofunctional benzoxazines, polyfunctional benzoxazines, and mixtures thereof; and hardener A thermosetting composition comprising:

6. 6. The thermosetting performance composition of claim 5, wherein the monofunctional benzoxazine is an acetylene-functional benzoxazine compound and the weight ratio of the acetylene-functional benzoxazine compound to the functionalized phthalonitrile monomer is between 1:1 and 1:

10.

7. A thermosetting polymer obtained by curing the thermosetting composition according to claim 2. wherein the thermoset polymer comprises two or more of: (i) a glass transition temperature (Tg) greater than 250°C; (ii) a storage modulus greater than 3500 MPa; (iii) a viscosity less than 250 centipoise at 75°C; and (iv) a char yield of at least 60%.

8. A thermosetting polymer obtained by curing the thermosetting composition according to claim 5.

9. 10. A process for producing a composite article comprising contacting a layer of reinforcing fibers with the thermosetting composition of claim 2 to coat and / or impregnate the reinforcing fibers; and curing the coated and / or impregnated reinforcing fibers to produce the composite article.

10. 10. A process for producing a composite article comprising contacting a layer of reinforcing fibers with the thermosetting composition of claim 5 to coat and / or impregnate the reinforcing fibers; and curing the coated and / or impregnated reinforcing fibers to produce the composite article.

11. 10. A method for producing a composite article in an RTM system, comprising the steps of: a) introducing a fiber matrix comprising reinforcing fibers into a mold; b) injecting the thermosetting composition of claim 5 into the mold; c) impregnating the fiber matrix with the thermosetting composition; d) heating the resin-impregnated matrix for a period of time to produce an at least partially cured solid article; and optionally e) subjecting the partially cured solid article to additional heat.

12. 10. A method of forming a composite article with a VaRTM system, comprising the steps of: a) introducing a fiber matrix comprising reinforcing fibers into a mold; b) injecting the thermosetting composition of claim 5 into the mold; c) reducing the pressure within the mold; d) maintaining the mold at the reduced pressure; e) impregnating the fiber matrix with the thermosetting composition; f) heating the resin-impregnated matrix to produce an at least partially cured solid article; and optionally g) subjecting the at least partially cured solid article to additional heat.

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