Epoxy resin composition and preparation method thereof

Abstract

Embodiments of the present disclosure generally relate to epoxy resin compositions and uses thereof. The epoxy resin composition includes an epoxy component including a first epoxy compound and a second epoxy compound. The epoxy resin composition includes a curing agent component including a first polyamine compound and a second polyamine compound.

Description

Epoxy Resin Compositions and Their Preparation Methods

[0001] Related applications for interaction

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 542,156, filed October 3, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of this disclosure generally relate to epoxy resin compositions and their uses. Background Technology

[0004] Aerospace structural components are typically manufactured in batch processes that incorporate one-component resin compositions, such as RTM6, Cycom 890, or EPS 600, including a premix of resin and hardener. Unfortunately, these one-component resin compositions lack temperature stability at temperatures above approximately -18°C and, once applied to aerospace structural components, have relatively long curing times, such as approximately 90 to approximately 120 minutes. Conventionally, cooling storage and transportation, such as below -18°C, are implemented. However, increased storage and transportation costs have been observed. Furthermore, the cooling temperatures during storage and transportation have been shown to alter one or more properties, such as viscosity, necessitating preheating of the one-component resin composition, thereby increasing processing time and reducing the number of parts that can be produced in a given time period.

[0005] Conventional methods for reducing processing time and the need for cooling storage and transportation focus on preparing two-component resin compositions. These compositions comprise a resin and a hardener, encapsulated as separate components and mixed before processing aerospace structural parts. While two-component compositions eliminate the need for preheating and reduce some costs associated with resin storage and transportation systems, curing times remain relatively long, such as from approximately 60 minutes to approximately 120 minutes. Furthermore, conventional two-component resin compositions typically rely on chemicals subject to regulatory review. Previous attempts to reduce the use of these chemicals and / or to reduce curing times, such as from approximately 2 minutes to approximately 5 minutes, of conventional bifunctional resin compositions, compared to the conventional glass transition temperatures of approximately 140°C or higher for aerospace structural parts, have also reduced the glass transition temperature of crosslinked epoxy resins to approximately 120°C. In fact, when operating at temperatures higher than the reduced glass transition temperature, this reduction can lead to the failure of the crosslinked epoxy resin.

[0006] Therefore, there is a need for new and improved two-component resin compositions that reduce curing time and produce higher glass transition temperatures. Summary of the Invention

[0007] Embodiments of this disclosure generally relate to epoxy resin compositions and their uses.

[0008] In some embodiments, this disclosure provides an epoxy resin composition comprising an epoxy component, the epoxy component comprising a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound. The epoxy resin composition includes a curing agent component comprising the first polyamine compound and the second polyamine compound. The second polyamine compound is an adduct of the first polyamine compound.

[0009] In some embodiments, this disclosure also provides a crosslinked epoxy resin composition as a reaction product of an epoxy component and a curing agent component. The epoxy component comprises a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound, and the curing agent component comprises a first polyamine compound and a second polyamine compound. The second polyamine compound is an adduct of the first polyamine compound.

[0010] In some embodiments, this disclosure also provides a method for forming a crosslinked epoxy resin composition. The method includes preparing a mixture by providing an epoxy component and a curing agent component to a resin transfer molding system. The epoxy component includes a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound. The curing agent component includes a first polyamine compound and a second polyamine compound. The second polyamine compound is an adduct of the first polyamine compound. A component is disposed in the resin transfer molding system. The mixture is disposed on the component. The crosslinked epoxy resin composition is formed by curing the mixture on the component at a temperature of about 120°C to about 180°C for about 10 minutes to about 30 minutes. Attached Figure Description

[0011] For a more detailed understanding of the features described above, a more specific description of the brief overview above can be obtained by referring to exemplary aspects, some of which are shown in the accompanying drawings.

[0012] Figure 1 is a graphical representation of the viscosity of the resin component relative to temperature according to an embodiment of the present disclosure.

[0013] Figure 2 is a graphical representation of the viscosity of the resin component at 80°C compared to time according to an embodiment of the present disclosure.

[0014] Figure 3 is a graphical representation of the viscosity of the curing agent component relative to temperature according to an embodiment of the present disclosure.

[0015] Figure 4 is a graphical representation of the viscosity of the curing agent component at 80°C compared to time according to an embodiment of the present disclosure.

[0016] Figure 5 is a graphical representation of the hot plate gelation time of epoxy resin relative to temperature according to an embodiment of the present disclosure.

[0017] Figure 6 is a graphical representation of the viscosity of the epoxy resin according to an embodiment of the present disclosure as a function of time.

[0018] Figure 7 is a graphical representation of the viscosity of epoxy resin at different temperatures compared to time according to embodiments of the present disclosure.

[0019] Figure 8 is a graphical representation of the refractive index of the epoxy resin composition according to an embodiment of the present disclosure compared to the stoichiometric deviation.

[0020] Figure 9 shows the glass transition temperature (T) of the epoxy resin composition according to embodiments of this disclosure. g A graphical representation of the initial deviation from stoichiometry.

[0021] Figure 10 is a graphical representation of the mechanical properties of the epoxy resin composition according to an embodiment of the present disclosure. Detailed Implementation

[0022] Embodiments of this disclosure generally relate to epoxy resin compositions and their uses. In some embodiments, this disclosure provides an epoxy resin composition comprising an epoxy component, the epoxy component comprising a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound. The epoxy resin composition comprises a curing agent component comprising a first polyamine compound and a second polyamine compound. The second polyamine compound is an adduct of the first polyamine compound. Without being theoretically limited, reduced curing times can be achieved using the epoxy resin compositions described herein, such as from about 10 minutes to about 30 minutes, such as from about 10 minutes to about 15 minutes, from about 15 minutes to about 20 minutes, from about 20 minutes to about 25 minutes, or from about 25 minutes to about 30 minutes. The crosslinked epoxy resin composition maintains a high drying glass transition temperature (T0) greater than 160°C. g (Initial, and higher humidity T such as above 140°C) g This is intended to allow application in the aerospace industry, thereby allowing the retention or modification of chemical properties such as tensile strength, thermal expansion, heat capacity, modulus, and / or electrical properties in crosslinked epoxy resins. Compared to conventional two-component resin compositions, the epoxy resin compositions have improved gelation time, thereby promoting safe chemical reactions during the formation of crosslinked epoxy resins. In summary, the crosslinked epoxy resin compositions of this disclosure can provide higher Tg values, such as greater than 140°C. g Initially, and with a relatively short curing time, and with limited to no deformation, porosity, shrinkage, and / or exothermic combustion zone.

[0023] For example, by using an epoxy component comprising at least two epoxy compounds including bisphenol A diglycidyl ether and tetraglycidyl methylenediphenylamine, and a curing agent component having at least two curing formulations including isophorone diamine and isophorone diamine adducts, a fast curing time and a high drying T can be prepared. g Initial and higher humidity T g The initial epoxy resin formulation.

[0024] Epoxy Resin Composition

[0025] The epoxy resin composition disclosed herein comprises an epoxy component and a curing agent component. The composition of the disclosed invention may further comprise additional additives, such as sand, fibers, fillers, thickeners, toughening agents, flame retardants, stabilizers, or combinations thereof. The composition may be formulated using the following formulation, wherein the wt% of each component is based on weight %, and the total wt% of the epoxy resin composition does not exceed 100 wt%. As used herein, the epoxy resin composition may comprise components of the composition (such as the epoxy component, curing agent component, additional additives, etc.) and / or reaction products of two or more components of the composition. Compared to an uncrosslinked epoxy resin composition, a crosslinked epoxy resin composition has an increased amount of reaction products.

[0026] Based on the combined weight of the epoxy component and the curing agent component, the amount of epoxy component in the epoxy resin composition can be from about 60 wt% to about 80 wt%, such as from about 60 wt% to about 65 wt%, from about 65 wt% to about 70 wt%, from about 70 wt% to about 75 wt%, or from about 75 wt% to about 80 wt%. In at least one embodiment, the amount (wt%) of epoxy component in the epoxy resin composition is about 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, or a range thereof, however covering higher or lower amounts.

[0027] Based on the combined weight of the epoxy composition and the curing agent component, the amount of the curing agent component in the epoxy resin composition can be from about 20 wt% to about 40 wt%, such as from about 20 wt% to about 25 wt%, from about 25 wt% to about 30 wt%, from about 30 wt% to about 35 wt%, or from about 35 wt% to about 40 wt%. In at least one embodiment, the amount (wt%) of the curing agent component in the epoxy resin composition is about 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or a range thereof, however covering higher or lower amounts.

[0028] The epoxy resin composition disclosed herein comprises a certain amount of epoxy component (epoxy compound) and the same amount of curing agent component. In these embodiments, the molar ratio of epoxy component to curing agent component is from about 2:1 mol / mol to about 3:1 mol / mol. In some embodiments, the molar ratio of epoxy component to curing agent component is about 2.2:1 mol / mol, 2.4:1 mol / mol, 2.6:1 mol / mol, 2.8:1 mol / mol, or 3.0:1 mol / mol, or a range thereof, however covering higher or lower molar ratios.

[0029] The molar ratio of epoxy components to curing agent components is based on functional equivalence (the reactive groups present in each component). That is, the molar ratio refers to the number of moles of (epoxy groups): (active hydrogens located on groups (such as amine groups) in the curing agent component).

[0030] Epoxy components

[0031] The epoxy resin composition includes an epoxy component. The epoxy component includes a first epoxy compound and a second epoxy compound. In at least one embodiment, at least one of the first epoxy compound or the second epoxy compound is independently a bisphenol A diglycidyl ether epoxy resin compound (CAS No. 1675-54-3). For example, the bisphenol A diglycidyl ether epoxy resin may include bis-[4-(2,3-epoxypropoxy)phenyl]propane. Commercially available bisphenol A diglycidyl ether epoxy resins may include EPIKOTE. TM LVEL 828 resin and / or EPON® 828 resin (available from Westlake Epoxy), DER 331 (available from Dow Chemicals), Araldite 6010 (available from Huntsman), and Epotuf 37-140 (available from Reichhold Chemical Co.). For example, bisphenol A diglycidyl ether epoxy resins may include 4,4'-isopropylidene diphenol-epimercohydride copolymer, propane, 2,2-bis[p-(2,3-epoxypropoxy)phenyl], phenol, 4,4'-(1-methylethylidene)bispolymer with (chloromethyl)ethylene oxide, or diglycidyl ether of bisphenol A homopolymer.

[0032] In at least one embodiment, at least one of the first epoxy compound or the second epoxy compound is independently a diglycidylaniline, such as a tetraglycidylmethylenediphenylamine compound. Commercial tetraglycidylmethylenediphenylamine epoxy resins may include EPIKOTE. TM496 and / or EPON® 496 resin (available from Westlake Epoxy). As a further example, tetraglycidylmethylenediphenylamine compounds may include 4,4'-methylenebis[N,N-bis(2,3-epoxypropyl)aniline] (CAS No. 28768-32-3) or tetraglycidylmethylenediphenylamine.

[0033] In at least one embodiment, each of the first, second, or third epoxy compounds may independently be a tetramethylbisphenol F-diglycidyl ether compound (CAS No. 113693-69-9). For example, tetramethylbisphenol F-diglycidyl ether may include 4,4'-methylenebis(2,6-dimethylphenol) (CAS No. 93705-66-9).

[0034] For example, the first epoxy compound may be a bisphenol A diglycidyl ether compound, such as bis-[4-(2,3-epoxypropoxy)phenyl]propane, the second epoxy compound may be a tetramethylbisphenol F-diglycidyl ether compound, and the third epoxy compound may be a tetraglycidylmethylenediphenylamine compound, such as 4,4'-methylenebis[N,N-bis(2,3-epoxypropyl)aniline].

[0035] Based on the total weight of the first and second epoxy compounds in the epoxy component, the first and second epoxy compounds may independently have a weight percentage of about 20 wt% to about 80 wt% of the epoxy component, such as about 20 wt% to about 35 wt%, about 25 wt% to about 40 wt%, about 40 wt% to about 55 wt%, or about 25 wt% to about 80 wt%. In at least one embodiment, the amount (wt%) of the first epoxy compound in the epoxy component is about 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 70, 80, or a range thereof, however covering higher or lower amounts.

[0036] For example, the first epoxy compound has a weight percentage of about 20 wt% to about 30 wt%, such as about 20 wt% to about 23 wt%, about 23 wt% to about 26 wt%, or about 26 wt% to about 30 wt%, and the second epoxy compound has a weight percentage of about 20 wt% to about 60 wt%, such as about 20 wt% to about 33 wt%, about 33 wt% to about 46 wt%, or about 46 wt% to about 60 wt%, wherein the sum of the first compound and the second compound does not exceed 100 wt%.

[0037] In at least one embodiment, the epoxy component may include a third epoxy compound. Based on the total weight of the first and second epoxy compounds in the epoxy component, the third epoxy compound may have a weight percentage of about 20 wt% to about 80 wt% of the epoxy component, such as about 20 wt% to about 35 wt%, about 25 wt% to about 40 wt%, about 40 wt% to about 55 wt%, or about 25 wt% to about 60 wt%. In at least one embodiment, the amount (wt%) of the first epoxy compound in the epoxy component is about 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 70, 80, or a range thereof, however covering higher or lower amounts.

[0038] For example, the epoxy component includes a first epoxy compound, a second epoxy compound, and a third epoxy compound, wherein the first epoxy compound has about 20 wt% to about 30 wt% of the total weight of the epoxy component, such as about 20 wt% to about 23 wt%, about 23 wt% to about 26 wt%, or about 26 wt% to about 30 wt% by weight; the second epoxy compound has about 20 wt% to about 60 wt% of the total weight of the epoxy component, such as about 20 wt% to about 33 wt%, about 33 wt% to about 46 wt%, or about 46 wt% to about 60 wt% by weight; and the third epoxy compound has about 25 wt% to about 55 wt% of the total weight of the epoxy component, such as about 20 wt% to about 453 wt%, about 43 wt% to about 56 wt%, or about 56 wt% to about 60 wt% by weight, wherein the sum of the first compound, the second compound, and the third compound does not exceed 100 wt%. As a further example, the epoxy component may include a first epoxy compound, a second epoxy compound, and a third epoxy compound, wherein the first epoxy compound has a weight percentage of about 14 wt% to about 25 wt% of the total weight of the epoxy resin composition, such as about 14 wt% to about 18 wt%, about 18 wt% to about 22 wt%, or about 22 wt% to about 25 wt%; the third epoxy compound has a weight percentage of about 14 wt% to about 25 wt% of the total weight of the epoxy resin composition, such as about 14 wt% to about 18 wt%, about 18 wt% to about 22 wt%, or about 22 wt% to about 25 wt%; and the second epoxy compound has a weight percentage of about 30 wt% to about 41 wt% of the total weight of the epoxy resin composition, such as about 30 wt% to about 34 wt%, about 34 wt% to about 38 wt%, or about 38 wt% to about 41 wt%, wherein the sum of the first compound, the second compound, and the third compound does not exceed 100 wt%.

[0039] In at least one embodiment, each of the first, second, or third epoxy compounds may have a weight-average molecular weight (Mw) of about 340 g / mol to about 470 g / mol and an epoxy equivalent of about 170 g / mol to about 235 g / mol, such as a weight-average molecular weight of about 360 g / mol to about 390 g / mol and an epoxy equivalent of about 180 g / mol to about 195 g / mol, or a weight-average molecular weight of about 360 g / mol to about 384 g / mol and an epoxy equivalent of about 185 g / mol to about 192 g / mol. As used herein, “epoxy equivalent” refers to the molecular weight of the epoxy compound divided by the number of epoxy groups present in the compound.

[0040] Curing agent components

[0041] The epoxy resin composition disclosed herein has a curing agent component. The curing agent component includes a first curing formulation and a second curing formulation. The first curing formulation and the second curing formulation may independently include one or more of the following: a first amine, a second amine, a third amine, a polyamine, an aliphatic polyamine, an alicyclic amine, an aromatic amine (such as imidazole), an anhydride, a thiol, an isocyanate, a Mannich base, a ketimine, an oxazoline, an amide amine, a modified polyamine resin prepared by reacting an aliphatic or alicyclic polyamine with a compound containing a functional group that reacts with an amine group, such as a compound containing a glycidyl ether or a compound containing a carboxyl group, or a combination thereof.

[0042] In one embodiment, the first and second formulations may independently be polyamines having a weight-average molecular weight (Mw) of about 15 g / mol to about 2000 g / mol, such as about 25 g / mol to about 1000 g / mol, such as about 35 g / mol to about 500 g / mol. In at least one embodiment, the Mw (g / mol) of one or more polyamines is about 15, 25, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, or 1000, or a range thereof, however covering higher or lower values. For example, the first and second formulations can independently be 1,3-bis(aminomethyl)cyclohexane, diethyltriamine, triethyltetramine, hexamethylenediamine, trimethylhexamethylenediamine, tetraethylpentamine, N,N',-dimethylpropanediamine, 1,3-bis(4-amino-3-methylcyclohexyl)methane, bis(p-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, 3,5,5-trimethyl-3-(aminomethyl)cyclohexylamine (CAS No. 2855-13-2), N-aminoethylpiperazine, m-phenylenediamine, p-phenylenediamine, bis(p-aminophenyl)methane, bis(p-aminophenyl)sulfone, m-xylenediamine, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 1,4-bis(aminomethyl)cyclohexane, phenol, 4,4'-(1-methylethylidene)bis-polymer and 5-amino-1,3,3-trimethylcyclohexanemethylamine and (chloromethyl)ethylene oxide (CAS No. 38294-64-3), and combinations thereof.

[0043] In one embodiment, the first cured formulation is a polyamine comprising isophorone diamine compounds such as 3,5,5-trimethyl-3-(aminomethyl)-cyclohexylamine. As a further example, the second cured formulation is a combination of a first polyamine and a second polyamine, the first polyamine comprising isophorone diamine compounds such as 3,5,5-trimethyl-3-(aminomethyl)-cyclohexylamine, and the second polyamine comprising isophorone diamine adduct compounds such as phenol, 4,4'-(1-methylethylidene) bispolymer, 5-amino-1,3,3-trimethylcyclohexanemethylamine, and (chloromethyl)ethylene oxide. Other suitable polyamines include any suitable amine-functionalized polymers, including but not limited to aminosilanes, amine-diacid adducts (industrially known as polyamide amines), and amine-epoxy adducts.

[0044] Based on the total weight of the first and second curing formulations in the curing agent component, the first curing formulation may have a weight percentage of about 30 wt% to about 80 wt% of the curing agent component, such as about 30 wt% to about 45 wt%, about 45 wt% to about 60 wt%, about 60 wt% to about 75 wt%, or about 75 wt% to about 80 wt%. In at least one embodiment, the amount (wt%) of the first curing formulation in the curing agent component is about 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, or a range thereof, however covering higher or lower amounts.

[0045] Based on the total weight of the first and second curing formulations in the curing agent component, the second curing formulation may have about 50 wt% to about 70 wt% of the curing agent component, such as about 50 wt% to about 55 wt%, about 55 wt% to about 60 wt%, about 60 wt% to about 65 wt%, or about 65 wt% to about 70 wt% by weight. In at least one embodiment, the amount (wt%) of the first curing formulation in the curing agent component is about 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, or a range thereof, however covering higher or lower amounts. For example, the first cured formulation may have a weight percentage of about 30 wt% to about 50 wt% of the curing agent component, and the second cured formulation may have a weight percentage of about 50 wt% to about 70 wt% of the curing agent component.

[0046] In one embodiment, the first cured formulation may contain 100 wt% isophorone diamine, such as 3-aminomethyl-3,5,5-trimethylcyclohexylamine. In one embodiment, the second cured formulation may be a mixture of one or more polyamines. For example, the second cured formulation may include about 40 wt% to about 50 wt% of a first polyamine, such as about 40 wt% to about 43 wt%, about 43 wt% to about 46 wt%, or about 46 wt% to about 50 wt%, and about 50 wt% to about 60 wt% and about 50 wt% to about 70 wt% of a second polyamine, such as about 50 wt% to about 53 wt%, about 53 wt% to about 56 wt%, or about 56 wt% to about 70 wt%, wherein the total weight percentage of the first and second polyamines does not exceed 100 wt%. For example, the second cured formulation may be about 40 wt% to about 50 wt% of a first polyamine, such as isophorone diamine such as 3,5,5-trimethyl-3-(aminomethyl)-cyclohexylamine, and about 50 wt% to about 70 wt% of a second polyamine, such as isophorone diamine adduct such as phenol, 4,4'-(1-methylethylidene) bis-polymer with 5-amino-1,3,3-trimethylcyclohexane methylamine and (chloromethyl) ethylene oxide.

[0047] In one embodiment, the curing agent component may include a first curing formulation and a second curing formulation of 100 wt% 3-aminomethyl-3,5,5-trimethylcyclohexylamine, the second curing formulation comprising about 48.5 wt% 3-aminomethyl-3,5,5-trimethylcyclohexylamine and about 51.5 wt% phenol, 4,4'-(1-methylethylidene) bis-polymer, and a mixture of 5-amino-1,3,3-trimethylcyclohexane methylamine and (chloromethyl) ethylene oxide.

[0048] In one embodiment of a second cured formulation comprising a first cured formulation having 100 wt% of a first polyamine and a mixture of about 40 wt% to about 60 wt% of the first polyamine and about 40 wt% to about 70 wt% of a second polyamine, the first polyamine may be present in the cured formulation at a weight percentage of about 50 wt% to about 80 wt%, such as about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, or about 70 wt% to about 80 wt%. For example, the first cured formulation may be about 30 wt% to about 80 wt% of a first polyamine, such as 3-aminomethyl-3,5,5-trimethylcyclohexylamine, and the second cured formulation may be about 20 wt% to about 70 wt% of a second polyamine, such as phenol, 4,4'-(1-methylethylidene)bispolymer and 5-amino-1,3,3-trimethylcyclohexanemethylamine and (chloromethyl)ethylene oxide.

[0049] In one embodiment, the curing agent component includes a first polyamine compound and a second polyamine compound, wherein the first polyamine compound has a weight percentage of about 10 wt% to about 22 wt% of the total weight of the epoxy resin composition, such as about 10 wt% to about 14 wt%, about 14 wt% to about 22 wt%, or about 15 wt% to about 22 wt%, and the second polyamine compound has a weight percentage of about 5 wt% to about 10 wt% of the total weight of the epoxy resin composition, such as about 5 wt% to about 8 wt%, about 6 wt% to about 8 wt%, or about 8 wt% to about 10 wt%, wherein the sum of the first compound, the second compound, and the third compound does not exceed 100 wt%.

[0050] Unbound by theory, the curing agent components containing the first and second curing formulations can reduce the curing time of the epoxy resin composition by accelerating the gelation of the curing agent component containing the epoxy component. Furthermore, curing agent components containing phenol, 4,4'-(1-methylethylidene) bispolymer, 5-amino-1,3,3-trimethylcyclohexanemethylamine, and (chloromethyl)ethylene oxide can reduce the reaction energy (exothermic) of the epoxy resin composition, while simultaneously reducing or eliminating potential runaway reactions.

[0051] additive

[0052] Epoxy resin compositions may include one or more additives. These additives include one or more solvents. Suitable solvents include organic solvents. Organic solvents may include alcohols; aliphatic, cycloalkanes, and aromatic hydrocarbons; ethers; esters; and ketones. Illustrative but non-limiting examples of organic solvents include hexane, heptane, octane, methylcyclohexane, xylene, toluene, ethanol, isopropanol, butanol, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, tetrahydrofuranol, ethylene glycol monomethyl ether, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and combinations thereof. Other solvents are also included. In some embodiments, the epoxy resin composition is anhydrous or substantially anhydrous. In some embodiments, the organic solvent includes n-butanol, toluene, xylene, or mixtures thereof.

[0053] In one embodiment, the additive may include one or more of the following: sand; accelerators; fillers and extenders, such as resin modifiers, such as phenolic resins, urea resins, melamine resins, acrylic resins, polyester resins, vinyl resins, asphalt resins, and polystyrene; surfactants; UV absorbers; thickeners; toughening agents, such as Kane Ace. TM MX150 (available from Kaneka Belgium); flame retardants; stabilizers; and combinations thereof.

[0054] The amounts of epoxy components, curing agent components, and / or additives used to form the epoxy resin composition can be used to define the molecular structure, chemical properties, and physical properties of the crosslinked epoxy resin composition.

[0055] Properties of crosslinked compositions

[0056] In some embodiments, the crosslinked epoxy composition has a drying temperature of about 160°C to about 210°C, such as about 160°C to about 170°C, about 170°C to about 180°C, about 180°C to about 190°C, about 190°C to about 200°C, or about 200°C to about 210°C. g Start. Drying T g The glass transition temperature is initially determined by testing in a dry environment with humidity levels such as about 0% to about 10%, about 0% to about 4%, about 4% to about 8%, or about 8% to about 10%. In some embodiments, the crosslinked epoxy composition has a humid Tw of about 140°C to about 180°C, such as about 140°C to about 150°C, about 150°C to about 160°C, about 160°C to about 170°C, or about 170°C to about 180°C. g Beginning. Damp T g The glass transition temperature is initially determined by testing in a wet or humid environment with humidity levels such as approximately 10% to approximately 100%, approximately 10% to approximately 30%, approximately 30% to approximately 50%, approximately 50% to approximately 70%, or approximately 70% to approximately 100%. A dry TV greater than approximately 160°C is not intended to be theoretically determined. g The initial and humid T temperature is above approximately 140°C. g The initial goal is to promote uniform operation in aerospace applications so that aerospace structural components can operate safely under high humidity and / or high temperature conditions.

[0057] In some embodiments, the crosslinked epoxy composition has a compressive modulus at 0°C of about 110 GPa to about 120 GPa, such as about 110 GPa to about 112 GPa, about 112 GPa to about 114 GPa, about 114 GPa to about 116 GPa, about 116 GPa to about 118 GPa, or about 118 GPa to about 120 GPa.

[0058] In some embodiments, the crosslinked epoxy composition has a compressive strength of about 700 MPa to about 950 MPa at 0°C, as measured by EN 2850, such as about 700 MPa to about 800 MPa, about 800 MPa to about 900 MPa, or about 900 MPa to about 950 MPa.

[0059] In some embodiments, the crosslinked epoxy composition has a tensile modulus at 0°C of about 120 GPa to about 140 GPa, as measured by DIN EN ISO 527-4, such as about 120 GPa to about 124 GPa, about 124 GPa to about 128 GPa, about 128 GPa to about 132 GPa, about 132 GPa to about 136 GPa, or about 136 GPa to about 140 GPa.

[0060] In some embodiments, the crosslinked epoxy composition has a tensile modulus of about 9 GPa to about 10 GPa at 90°C, as measured by DIN EN ISO 527-4, such as about 9.1 GPa to about 9.4 GPa, about 9.4 GPa to about 9.6 GPa, about 9.6 GPa to about 9.8 GPa, or about 9.8 GPa to about 10 GPa.

[0061] In some embodiments, the crosslinked epoxy composition has a tensile strength of about 1600 MPa to about 1800 MPa at 0°C, as measured by DIN EN ISO 527-4, such as about 1600 MPa to about 1650 MPa, about 1650 MPa to about 1700 MPa, about 1700 MPa to about 1750 MPa, or about 1750 MPa to about 1800 MPa.

[0062] In some embodiments, the crosslinked epoxy composition has a tensile strength of about 35 MPa to about 50 MPa at 90°C, as measured by DIN EN ISO 527-4, such as about 35 MPa to about 40 MPa, about 40 MPa to about 45 MPa, or about 45 MPa to about 50 MPa.

[0063] Unbound by theory, the epoxy resin compositions of this disclosure can provide similar chemical properties to comparable epoxy resins while maintaining faster curing time and sufficient Tc. g Beginning.

[0064] method

[0065] The method disclosed herein may include forming an epoxy resin composition by providing an epoxy component and a curing agent component to a resin transfer molding system. The resin transfer molding (RTM) system may include one, two, or three storage tanks, which may be temperature-controlled and / or pressure-controlled, such as vacuum-controlled. The RTM system may include low-pressure RTM (LP RTM) such as less than 120 bar, including a static mixer. The RTM system may include high-pressure RTM (HP RTM) including a high-pressure component such as a mixing head, such as about 120 bar to about 160 bar, such as about 120 bar to about 140 bar, or about 140 bar to about 160 bar. The RTM may deliver the components to a tool such as a press, for example by injection. The resin transfer molding system can mix the curing agent component and the epoxy component in a ratio of about 2.1:1 mol / mol to about 3:1 mol / mol, such as about 2:1 mol / mol, about 2.4:1 mol / mol, about 2.6:1 mol / mol, about 2.8:1 mol / mol, or about 3:1 mol / mol.

[0066] Aerospace structural components can be disposed in a resin transfer molding system. Aerospace structural components may include one or more of a glass component, a carbon component, a polymer component, or a metal component. For example, aerospace structural components may include a carbon fiber component, such as graphene, graphite, single-walled nanotubes, or double-walled nanotubes. In some embodiments, the carbon component composition has about 50 wt% to about 70 wt% of carbon component and about 30 wt% to about 50 wt% of epoxy resin composition.

[0067] The method involves placing an epoxy resin composition of a resin transfer molding system onto or over an aerospace structural component such that the mixture covers and / or inserts into at least a portion of the aerospace component. In one embodiment, the epoxy resin composition can be injected via the resin transfer molding system at an injection rate of about 1 g / sec to about 200 g / sec, such as about 10 g / sec to about 100 g / sec, about 100 g / sec to about 150 g / sec, or about 150 g / sec to about 200 g / sec. Without being theoretically limited, higher injection rates can be used for larger aerospace components, such as wings, while slower injection rates can be used for smaller aerospace components, such as switches.

[0068] The epoxy resin composition is then crosslinked at a curing temperature of about 120°C to about 190°C, such as about 120°C to about 130°C, about 130°C to about 140°C, about 140°C to about 150°C, about 150°C to about 160°C, about 160°C to about 170°C, about 170°C to about 180°C, or about 180°C to about 190°C. The epoxy resin composition can crosslink for about 30 seconds to about 30 minutes, such as about 30 seconds to about 1 minute, about 1 minute to about 5 minutes, about 5 minutes to about 10 minutes, about 10 minutes to about 15 minutes, about 15 minutes to about 20 minutes, about 20 minutes to about 25 minutes, or about 25 minutes to about 30 minutes. For example, the epoxy resin composition can crosslink at a temperature of about 170°C for about 15 minutes. For example, the epoxy resin composition can crosslink at a temperature of about 120°C for about 30 minutes. Unbound by theory, the approximately 15-minute curing time reduces processing time to allow for faster fabrication of aerospace components, thereby reducing fabrication costs.

[0069] In at least one embodiment, the epoxy resin composition may undergo gelation within about 30 seconds to about 5 minutes, such as about 30 seconds to about 1 minute, about 1 minute to about 2 minutes, about 2 minutes to about 3 minutes, about 3 minutes to about 4 minutes, or about 4 minutes to about 5 minutes, wherein the gelation time is the amount of time for processing and / or injecting the mixture. Without being bound by theory, faster gelation, attributed to the rapid initial gelation of the epoxy compound and / or curing agent component compounds, followed by substantially complete curing, can promote a reduction or elimination of runaway reactions during the formation of the crosslinked epoxy resin.

[0070] In at least one embodiment, the epoxy resin composition can be crosslinked at a first temperature for a first time period and subsequently crosslinked at a second temperature for a second time period. The first temperature and the second temperature may be the same or different. For example, the epoxy resin composition can be crosslinked at a first temperature of about 120°C for about 30 minutes, wherein the resin transfer molding system can adapt to a second temperature of about 170°C and cure the epoxy resin composition for about 15 minutes. In at least one embodiment, the resin transfer molding system cures the epoxy resin composition by raising the temperature from room temperature, such as about 20°C to about 25°C, to a curing temperature, such as about 120°C to about 190°C, and holding the curing temperature for a period of time such as about 30 seconds to about 1 minute, about 1 minute to about 5 minutes, about 5 minutes to about 10 minutes, about 10 minutes to about 15 minutes, about 15 minutes to about 20 minutes, about 20 minutes to about 25 minutes, or about 25 minutes to about 30 minutes. Unbound by theory, a curing temperature of approximately 170°C can reduce the gelation time of the mixture from approximately 4 minutes to less than one minute, thereby increasing the viscosity of the epoxy composition so that it does not detach from the aerospace components, thus reducing the need for additional epoxy compositions on the aerospace components.

[0071] The method of this disclosure may also include forming an epoxy resin composition by providing an epoxy component and a curing agent component to a processing system, such as a pre-nailing system, wherein the epoxy resin system embeds a textile component or other components suitable for embedding the epoxy resin composition. The processing system may include a lamination system. The lamination system may include a system for providing a mixture of epoxy and curing agent components to a component, wherein the mixture is mechanically distributed on the component. The processing system may include an infusion system. The infusion system may include an open system or a closed system. The infusion system includes a storage tank that holds the mixture of epoxy and curing agent components. The infusion system includes a preform located within the infusion system, the infusion system having one or more screws or a vacuum structure with foil. The infusion system includes a vacuum pump that allows the epoxy resin composition to flow from a first side of the preform to a second side of the preform so that infusion occurs within the preform. The infused epoxy resin composition can then be cured. The method of this disclosure may also include forming an epoxy resin composition by providing an epoxy component and a curing agent component to a compression system. The compression system may include a compressor that mechanically forces the epoxy resin composition onto or into the components.

[0072] Example

[0073] The following examples are provided to offer a complete disclosure and description of how to prepare and use embodiments of this disclosure to those skilled in the art, and are not intended to limit the scope of embodiments of this disclosure. Every effort has been made to ensure the accuracy of the figures used, but some experimental errors and deviations should be taken into account.

[0074] The crosslinked epoxy resin composition disclosed herein is prepared by mixing about 100 g of an epoxy component comprising 25 wt% bisphenol A diglycidyl ether, 25 wt% tetramethylbisphenol F-diglycidyl ether, and 50 wt% 4,4'-methylenebis[N,N-bis(2,3-epoxypropyl)aniline] with about 37.2 g of a curing agent component comprising 40 wt% 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 48.5 wt% 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 51.5 wt% phenol, 4,4'-(1-methylethylidene) bis-polymer and 5-amino-1,3,3-trimethylcyclohexane methylamine and (chloromethyl) ethylene oxide, as shown in Tables 1 and 2.

[0075] Table 1. Epoxy Components

[0076]

[0077] Table 2. Curing agent components

[0078]

[0079] The crosslinked epoxy resin composition was cured at 170°C for 15 min, and two samples were analyzed. Sample 1 consisted of pure crosslinked epoxy resin without fibers, while the sample contained crosslinked epoxy resin with approximately 61 wt% fibers. The enthalpy of reaction was determined according to DIN 53445. The gel point was determined according to DIN 16945. Drying temperature... g Initial and damp T g The starting point was determined according to DIN EN 61006. Moisture absorption was determined according to DIN EN 2823, a modified version of this standard, by immersing the sample in boiling water for 48 hours. Interlaminar shear strength (ILSS) was determined based on interlaminar shear strength (ILSS). The results are shown in Table 3.

[0080] Table 3. Crosslinked epoxy resin compositions

[0081]

[0082] Crosslinked epoxy resin compositions exhibit low moisture absorption, which indicates a longer shelf life during curing, thereby reducing the amount of maintenance required.

[0083] Referring now to Figure 1, a graph showing the viscosity of the epoxy component versus temperature is presented. At room temperature, such as about 25°C, the viscosity is about 68 Pa*s, decreasing to about 8 Pa*s at a temperature of about 40°C. The viscosity then continues to decrease to less than 200 mPa*s as the temperature approaches 120°C. Without being theoretically constrained, a viscosity of less than 200 mPa*s allows for increased processability of the epoxy composition.

[0084] Referring now to Figure 2, the viscosity of the epoxy component compared to time is shown. At approximately 200 mPa*s, the viscosity of the epoxy component stabilizes up to 70 hours. Without being theoretically constrained, this viscosity stabilization up to 70 hours at approximately 200 mPa*s allows for improvements in the shelf life of the epoxy component.

[0085] Referring now to Figure 3, a graph showing the viscosity of the curing agent component compared to temperature is presented. At room temperature, such as approximately 25°C, the viscosity is approximately 1,000 mPa*s, decreasing to approximately 300 mPa*s at approximately 40°C. Then, as the temperature approaches 120°C, the viscosity continues to decrease to less than 50 mPa*s. Due to this temperature-based decrease in viscosity, and its ability to cure at temperatures from room temperature up to 120°C, the curing agent component can be incorporated into multiple processes. Furthermore, due to the curing agent component's ability to cure at lower temperatures, a reduction in aging of the curing agent component can occur.

[0086] Referring now to Figure 4, a graph showing the viscosity of the curing agent component compared to time is presented. When tested at 80°C, the viscosity of the curing agent component remained stable at approximately 25 mPa*s for up to 70 hours. This stability up to 70 hours prevents aging of the curing agent component, allowing the reaction to continue even after storage periods such as seconds, days, weeks, months, or years.

[0087] Referring now to Figure 5, a hot plate gelation time graph of the epoxy resin composition versus temperature is shown. When curing at a temperature of approximately 120°C, gelation of the epoxy resin composition occurs at a rate of approximately 280 seconds, while when curing at a temperature of 170°C, gelation occurs even faster, such as approximately 50 seconds. Without being theoretically constrained, by curing at lower temperatures and having longer gelation times, more epoxy resin composition can be injected while the existing composition is being processed, thus allowing for the fabrication of larger parts in a single coating process.

[0088] Referring now to Figure 6, a viscosity-time graph of the epoxy resin composition is shown. The temperature is approximately 25°C, where the viscosity of the epoxy resin composition increases from approximately 18 Pa*s to approximately 120 Pa*s after approximately 170 min. Without being theoretically constrained, this viscosity increase indicates that the epoxy resin composition cures even at a temperature of approximately 25°C.

[0089] Referring now to Figure 7, a graph showing the viscosity of epoxy resin compositions cured at different temperatures versus time is presented. Epoxy resin compositions cured at approximately 170°C show a faster increase in viscosity, such as in about 40–60 seconds, compared to approximately 4 minutes for compositions cured at approximately 120°C. Without being theoretically constrained, higher curing temperatures could result in faster curing rates for epoxy resin compositions, allowing for increased fabrication of aerospace components due to reduced processing time.

[0090] Referring now to Figure 8, the refractive index of the epoxy resin composition is shown relative to the stoichiometric deviation. When the stoichiometric deviation is 0%, the epoxy resin composition exhibits a refractive index of approximately 1.56075. Without being bound by theory, mixing ratios can be confirmed using the refractive index to ensure proper formation of the epoxy resin composition.

[0091] Referring now to Figure 9, the T of the epoxy resin composition is shown. g The initial value is compared to the stoichiometric deviation. When the stoichiometric deviation percentage is 0%, the epoxy resin composition exhibits a T value of approximately 195°C. g Initially, when the stoichiometric deviation percentage is approximately 5%, T g Initially maintained at approximately 195°C. Unbound by theory, T remains stable even during periods of stoichiometric deviation, despite incorrect mixing ratios. g Initial allow T g Consistency at the start increases the ease of use of the epoxy resin composition.

[0092] Referring now to Figure 10, the mechanical properties of the epoxy resin composition compared to a comparable composition are shown. The epoxy resin composition exhibits similar and / or equivalent chemical properties to the comparable epoxy resin, but has a faster curing time and sufficient Tc. gStarting point. The comparable chemical properties and faster curing time of epoxy resin compositions allow for faster preparation of parts suitable for the aerospace or automotive industries. Comparable compositions have a compressive modulus of about 110 GPa to about 130 GPa at 0°C, as measured by EN 2850. Comparable compositions have a compressive strength of about 1000 MPa to about 1300 MPa at 0°C, as measured by EN 2850. Comparable compositions have a tensile modulus of about 125 GPa to about 135 GPa at 0°C, as measured by DIN EN ISO 527-4. Comparable compositions have a tensile modulus of about 8 GPa to about 10 GPa at 90°C, as measured by DIN EN ISO 527-4. Comparable compositions have a tensile strength of about 1800 MPa to about 2200 MPa at 0°C, as measured by DIN EN ISO 527-4. Comparable compositions have tensile strengths of about 35 MPa to about 80 MPa at 90°C, as measured by DIN ENISO 527-4, as shown in Table 4.

[0093] Table 4. Comparable Mechanical Properties

[0094]

[0095] The epoxy resin composition has a compressive modulus of about 110 GPa to about 120 GPa at 0°C, as measured by EN 2850. A comparable composition has a compressive strength of about 700 MPa to about 950 MPa at 0°C, as measured by EN 2850. A comparable composition has a tensile modulus of about 120 GPa to about 140 GPa at 0°C, as measured by DIN EN ISO 527-4. A comparable composition has a tensile modulus of about 9 GPa to about 10 GPa at 90°C, as measured by DIN EN ISO 527-4. A comparable composition has a tensile strength of about 1600 MPa to about 1800 MPa at 0°C, as measured by DIN EN ISO 527-4. A comparable composition has a tensile strength of about 35 MPa to about 50 MPa at 90°C, as measured by DIN EN ISO 527-4. Unbound by theory, the epoxy resin compositions of this disclosure exhibit chemical properties similar to comparable epoxy resins, while maintaining faster curing times and sufficient Tc. g The initial steps are shown in Table 5.

[0096] Table 5. Mechanical properties of epoxy resin compositions

[0097]

[0098] Comparable compositions have properties suitable for methyl ethyl ketone, fuels, and Skydrol. TM (Available from Eastman Aviation Solutions), Propylene Glycol, ABC-S TM The resistance of the medium for Type IV (supplied by Killfrost) and non-phenolic paint strippers tested according to EN 2563 is shown in Table 6.

[0099] Table 6. Comparison of fluid resistance

[0100]

[0101] The epoxy resin composition has properties suitable for methyl ethyl ketone, fuels, Skydrol TM (Available from Eastman Aviation Solutions), Propylene Glycol, ABC-S TM The resistance of the medium for Type IV (supplied by Killfrost) and non-phenolic paint strippers tested according to EN 2563 is shown in Table 7.

[0102] List of Implementation Methods

[0103] This disclosure specifically provides the following aspects, each of which may be considered to include any alternative implementations as appropriate:

[0104] E1. An epoxy resin composition comprising a first epoxy compound as a bisphenol A diglycidyl ether compound; an epoxy component as a second epoxy compound as a diglycidyl aniline compound; and a curing agent component comprising a first polyamine compound and a second polyamine compound, wherein the second polyamine compound comprises an adduct of the polyamine compound.

[0105] E2. An epoxy resin composition as described in embodiment E1, wherein the epoxy resin composition further comprises a third epoxy compound.

[0106] E3. An epoxy resin composition as described in embodiment E2, wherein the third epoxy compound comprises a tetramethylbisphenol F-diglycidyl ether compound.

[0107] E4. An epoxy resin composition as described in embodiment E2 or E3, wherein, based on the total weight of the epoxy components, a first epoxy compound is present in the epoxy components at about 20 wt% to about 30 wt%, a second epoxy compound is present in the epoxy components at about 20 wt% to about 60 wt%, and a third epoxy compound is present in the epoxy components at about 20 wt% to about 60 wt%, wherein the total weight does not exceed 100 wt%.

[0108] E5. An epoxy resin composition as described in any one of embodiments E1-E4, wherein the first polyamine compound comprises an isophorone diamine compound.

[0109] E6. An epoxy resin composition as described in embodiment E5, wherein isophorone diamine is 3-aminomethyl-3,5,5-trimethylcyclohexylamine.

[0110] E7. An epoxy resin composition as described in any of embodiments E1-E6, wherein the second polyamine compound comprises an isophorone diamine adduct compound.

[0111] E8. An epoxy resin composition as described in embodiment E7, wherein the isophorone diamine adduct compound is phenol, 4,4'-(1-methylethylidene) bis-polymer, 5-amino-1,3,3-trimethylcyclohexanemethylamine, and (chloromethyl)ethylene oxide.

[0112] E9. The epoxy resin composition of embodiment E8, wherein the first polyamine compound is about 30 wt% to about 50 wt% based on the total weight of the curing agent components, and the second polyamine compound is about 50 wt% to about 70 wt% based on the total weight of the curing agent components, wherein the total weight does not exceed 100 wt%.

[0113] E10. A crosslinked epoxy resin as a reaction product of an epoxy component and a curing agent component: the epoxy component comprises a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound; and the curing agent component comprises a first polyamine compound and a second polyamine compound, wherein the second polyamine compound is an adduct of the polyamine compound.

[0114] E11. A crosslinked epoxy resin composition according to any one of embodiments E1-E10, wherein the crosslinked epoxy resin is cured at a temperature of about 120°C to about 130°C for about 20 to about 30 minutes.

[0115] E12. A crosslinked resin composition of any one of embodiments E1-E11, wherein the crosslinked epoxy resin composition is cured at a temperature of about 160°C to about 170°C for about 10 minutes to about 20 minutes.

[0116] E13. A crosslinked epoxy resin composition as described in any one of embodiments E1-E12, wherein the crosslinked epoxy resin composition has a dry glass transition temperature (Tg) starting at about 160°C to about 210°C.

[0117] E14. A crosslinked epoxy resin composition as described in any one of embodiments E1-E13, wherein the crosslinked epoxy resin composition has a moisture glass transition temperature (Tg) starting at about 140°C to about 180°C.

[0118] E15. A method for forming a crosslinked epoxy resin composition, the method comprising preparing a mixture by providing an epoxy component and a curing agent component to a resin transfer molding system, wherein the epoxy component comprises a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound, and wherein the curing agent component comprises a first polyamine compound and a second polyamine compound, wherein the second polyamine compound is an adduct of the polyamine compound; disposing a component in the resin transfer molding system; disposing the mixture on the component; and forming the crosslinked epoxy resin composition by curing the mixture on the component.

[0119] E16. The method of embodiment E15, wherein preparing the mixture comprises mixing the epoxy component and the curing agent component at a ratio of about 2:1 mol / mol to about 3:1 mol / mol.

[0120] E17. The method of embodiment E15 or E16, wherein placing the mixture on the aerospace structural component comprises injecting the mixture onto the aerospace structural component at an injection rate of about 1 g / sec to about 200 g / sec.

[0121] E18. The method of any one of embodiments E15-E17, wherein curing the mixture comprises curing at a temperature of about 120°C to about 180°C for about 10 minutes to about 30 minutes.

[0122] E19. The method of embodiment E18, wherein curing the mixture comprises curing at a temperature of about 120°C to about 130°C for about 20 to about 30 minutes.

[0123] E20. The method of embodiment E18, wherein curing the mixture comprises curing at a temperature of about 160°C to about 170°C for about 10 minutes to about 20 minutes.

[0124] E21. The method of any one of embodiments E15-E20, wherein curing the mixture comprises curing the mixture for a first time period at a first temperature and curing the mixture for a second time period at a second temperature, wherein the first temperature is different from the second temperature and the first time period is the same as or different from the second time period.

[0125] In summary, the epoxy resin compositions and their preparation methods described herein can provide higher T values, such as greater than 140°C, after a relatively short curing time. gThe initial cross-linked epoxy resin composition reduces processing time, increases the number of aerospace components that can be produced per unit time, and lowers the cost of producing aerospace components. Furthermore, compared to conventional two-component resin compositions, the epoxy resin composition has an improved gelation time, thereby promoting the reduction or elimination of runaway reactions during the formation of the cross-linked epoxy resin.

[0126] Each of the aforementioned figures may be preceded by the words “about,” “at least about,” “less than about,” or “greater than about,” and any of the aforementioned figures may be used alone to describe the open range of the end or in combination to describe the closed range of the end.

[0127] As will be apparent from the foregoing general description and specific aspects, various modifications may be made without departing from the spirit and scope of this disclosure, although the forms shown and described are as follows. Therefore, this disclosure is not intended to be limited thereto. Similarly, the term “comprising” is considered synonymous with the term “including.” Likewise, whenever the transitional phrase “comprising” precedes a composition, element, or group of elements, it should be understood that we also consider the same composition or group of elements preceded by the transitional phrases “substantially composed of,” “composed of,” “selected from,” or “is,” and vice versa, terms such as “comprising,” “substantially composed of,” and “composed of” also include the product of the combination of elements listed after that term.

[0128] For the purposes of this disclosure, and unless otherwise specified, all numerical values ​​in the embodiments and claims herein are modified by the terms "about" or "approximately" and take into account experimental errors and variations expected by those skilled in the art. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, a range from any lower limit may be combined with any upper limit to describe a range not explicitly stated, and a range from any lower limit may be combined with any other lower limit to describe a range not explicitly stated, and in the same manner, a range from any upper limit may be combined with any other upper limit to describe a range not explicitly stated. Furthermore, each point or individual value between its endpoints is included within a range, even if not explicitly stated. Thus, each point or individual value may serve as its own lower or upper limit in combination with any other point or individual value or any other lower or upper limit to describe a range not explicitly stated.

[0129] As used herein, the indefinite article “a / an” shall mean “at least one” unless otherwise specified or the context clearly indicates otherwise. For example, an aspect containing “monosome” includes an aspect containing one, two, or more monosomes, unless otherwise specified or the context clearly indicates that it contains only one monosome.

[0130] While the foregoing pertains to aspects of this disclosure, other and further aspects of this disclosure may be designed without departing from its essential scope, which is defined by the following claims.

Claims

1. An epoxy resin composition, the composition comprising: an epoxy component, the component comprising: As the first epoxy compound of bisphenol A diglycidyl ether compounds; As a second epoxide compound of diglycidyl aniline; and curing agent components, said components including: a first polyamine compound; and a second polyamine compound, wherein the second polyamine compound comprises an adduct of the polyamine compound.

2. The epoxy resin composition of claim 1, wherein the epoxy resin composition further comprises a third epoxy compound.

3. The epoxy resin composition of claim 2, wherein the third epoxy compound comprises a tetramethylbisphenol F-diglycidyl ether compound.

4. The epoxy resin composition of claim 3, wherein: Based on the total weight of the epoxy components, the first epoxy compound is present in the epoxy agent at about 20 wt% to about 30 wt%, the second epoxy compound is present in the epoxy component at about 20 wt% to about 60 wt%, and the third epoxy compound is present in the epoxy component at about 20 wt% to about 60 wt%, wherein the total weight does not exceed 100 wt%.

5. The epoxy resin composition of claim 1, wherein the first polyamine compound comprises isophorone diamine compound.

6. The epoxy resin composition of claim 5, wherein the isophorone diamine compound is 3-aminomethyl-3,5,5-trimethylcyclohexylamine.

7. The epoxy resin composition of claim 1, wherein the second polyamine compound comprises an isophorone diamine adduct compound.

8. The epoxy resin composition of claim 7, wherein the isophorone diamine adduct compound is phenol, 4,4'-(1-methylethylidene) bis-polymer, 5-amino-1,3,3-trimethylcyclohexane methylamine, and (chloromethyl) ethylene oxide.

9. The epoxy resin composition of claim 1, wherein: Based on the total weight of the curing agent components, the first polyamine compound is about 30 wt% to about 50 wt%, and based on the total weight of the curing agent components, the second polyamine compound is about 50 wt% to about 70 wt%, wherein the total weight does not exceed 100 wt%.

10. A crosslinked epoxy resin composition as a reaction product of: an epoxy component comprising a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound; and a curing agent component comprising a first polyamine compound and a second polyamine compound, wherein the second polyamine compound is an adduct of the polyamine compound.

11. The crosslinked epoxy resin composition of claim 10, wherein the crosslinked epoxy resin is cured at a temperature of about 120°C to about 130°C for about 20 to about 30 minutes.

12. The crosslinked epoxy resin composition of claim 10, wherein the crosslinked epoxy resin composition is cured at a temperature of about 160°C to about 170°C for about 10 minutes to about 20 minutes.

13. The crosslinked epoxy resin composition of claim 10, wherein the crosslinked epoxy resin composition has a dry glass transition temperature (Tg) starting at about 160°C to about 210°C.

14. The crosslinked epoxy resin composition of claim 10, wherein the crosslinked epoxy resin composition has a starting wet glass transition temperature (Tg) of about 140°C to about 180°C.

15. A method for forming a crosslinked epoxy resin composition, the method comprising: A mixture is produced by providing an epoxy component and a curing agent component to a resin transfer molding system, wherein the epoxy component comprises a first epoxy compound as a bisphenol A diglycidyl ether compound and a second epoxy compound as a diglycidyl aniline compound, and wherein the curing agent component comprises a first polyamine compound and a second polyamine compound, wherein the second polyamine compound is an adduct of the polyamine compound; The component is placed in the resin transfer molding system; The mixture is applied to the component; The crosslinked epoxy resin composition is formed by curing the mixture on the component.

16. The method of claim 15, wherein generating the mixture comprises: The epoxy component and the curing agent component are mixed at a ratio of about 2:1 mol / mol to about 3:1 mol / mol.

17. The method of claim 15, wherein disposing of the mixture on the aerospace structural component comprises: The mixture is injected onto the aerospace structural component at an injection rate of about 1 g / sec to about 200 g / sec.

18. The method of claim 15, wherein curing the mixture comprises: Curing time is approximately 10 to 30 minutes at a temperature of approximately 120°C to approximately 180°C.

19. The method of claim 18, wherein curing the mixture comprises: Curing time is approximately 20 to 30 minutes at a temperature of approximately 120°C to approximately 130°C.

20. The method of claim 18, wherein curing the mixture comprises: Curing time is approximately 10 to 20 minutes at a temperature of approximately 160°C to approximately 170°C.

21. The method of claim 15, wherein curing the mixture comprises: The mixture is cured at a first temperature for a first time period and at a second temperature for a second time period, wherein the first temperature is different from the second temperature and the first time period is the same as or different from the second time period.

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