Novel aliphatic polyamines for use as curing agents for epoxy resins.

Abstract

The present invention relates to novel aliphatic polyamines with methyl substituents for use in curing epoxy resins, and the preparation of such aliphatic polyamines. The present invention further relates to corresponding epoxy resin compositions comprising epoxy resins and such aliphatic polyamines, a process for curing such compositions, and the resulting cured epoxy resins. These curing agents combine relatively rapid curing at moderately high temperatures with a relatively long pot life at room temperature. At the same time, these curing agents enable cured epoxy resins with good mechanical properties and high glass transition temperatures.

Description

[Technical field]

[0001] The present invention relates to novel aliphatic polyamines having methyl substituents for use in curing epoxy resins, and the preparation of such aliphatic polyamines. These aliphatic polyamines have the general chemical formula HN(-Q-NH) n The aliphatic polyamine is represented by -A-NH-Q-NH2, where n is 0 or 1, A is -CH2-CH(CH3)-CH2- or -CH2-CH2-CH(CH3)- or -CH(CH3)-CH2-CH2-, and each Q is independently -CH(CH3)-CH2- or -CH2-CH(CH3)-. The present invention further relates to a corresponding epoxy resin composition comprising an epoxy resin and such an aliphatic polyamine, a process for curing such a composition, and the resulting cured epoxy resin. Such an epoxy resin composition combines relatively rapid curing at moderately high temperatures with a relatively long pot life at room temperature. At the same time, such an epoxy resin composition allows for a cured epoxy resin with good mechanical properties and a high glass transition temperature. [Background technology]

[0002] Epoxy resins are well known and are used as adhesives, as surface coating materials, and as molding and laminating materials, as well as for the production of fiber-reinforced composites, due to their toughness, flexibility, adhesion and chemical resistance.

[0003] Typical hardeners for epoxy resins are polyamines which undergo polyaddition reactions (chain extension). Highly reactive polyamines are generally added to the epoxy resin only shortly before the desired cure. Such systems are therefore so-called two-component (2K) systems.

[0004] In principle, amine-based hardeners (amino hardeners) are classified according to their chemical structure into aliphatic, cycloaliphatic, or aromatic types. In addition, they can be classified according to the degree of substitution of the amino group, which can be primary, secondary, or tertiary. However, in the case of tertiary amines, a catalytic mechanism of curing of epoxy resins is assumed, whereas the basis for the formation of the polymer network of secondary amines and of primary amines is a stoichiometric curing reaction.

[0005] In general, aliphatic amines have been shown to exhibit the highest reactivity among primary amino hardeners in epoxy curing. Cycloaliphatic amines typically exhibit somewhat slower reactivity, while aromatic amines (amines in which the amino group is attached directly to a carbon atom of an aromatic ring) are by far the least reactive.

[0006] These known differences in reactivity are exploited in the curing of epoxy resins so that processing times and curing rates can be adjusted as needed. In many applications, such as the production of fiber-reinforced composites (composites), it is desirable for a freshly prepared mixture of epoxy resin and amino curing agent (epoxy resin composition) to have a long processing time (pot life: the period until the composition can be processed), for example, to allow sufficient embedding and impregnation of the reinforcing fibers. In the production of composites by pultrusion or by injection or injection methods such as vacuum-assisted resin transfer molding (VARTM) or resin transfer molding (RTM), a sufficiently long processing time is necessary for the matrix components to efficiently wet the reinforcing fibers and, especially in the production of large parts, to be uniformly distributed around the reinforcing fibers. For the same reason, it is also desirable for the epoxy resin composition to have a low mixing viscosity. At the same time, the epoxy resin composition must cure within an acceptable time at high temperatures to allow short production cycles and thus high productivity.

[0007] Cycloaliphatic amines, such as isophorone diamine (IPDA), allow relatively long processing times and, with appropriate formulation, also at the same time high curing speeds and low mix viscosities (Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, Germany, 2012, Vol. 13, Epoxy Resins, H. Pham & M Marks, chpt. 15.1.1.2, Tab. 14 (online: 15.10.2005, DOI: 10.1002 / 14356007.a09_547.pub2)). Furthermore, epoxy resins cured with cycloaliphatic amines such as IPDA are generally characterized by a high glass transition temperature. Cycloaliphatic amines are therefore also used in particular for the production of composites. Aromatic amines and anhydrides, which are also used for the production of composites, have the disadvantage that long curing times and high curing temperatures are required. Furthermore, curing with anhydrides generally results in relatively brittle resins. EP 2307358A describes the addition of tetramethylguanidine to epoxy resins cured with IPDA and D230 polyetheramine to simultaneously increase pot life and cure speed, however the system described therein has a relatively low glass transition temperature.

[0008] Recently, WO 2020 / 212258A has described the fast cure speed typical of conventional aliphatic amino hardeners such as diethylenetriamine (DETA) and the long pot life and high glass transition temperature (T T ) typical of conventional cycloaliphatic amino hardeners such as isophoronediamine (IPDA). g Such amino curing agents are particularly suitable for the preparation of fiber-based composites, such as, for example, pultrusion, filament winding, prepreg, resin transfer molding (RTM), vacuum assisted resin transfer molding (VARTM), bulk mold compression (BMC) or sheet mold compression (SMC).

[0009] Against this background, there is therefore a need for further amino hardeners, particularly in the production of composites, for example by pultrusion, filament winding, fiber impregnation, RTM, VARTM, BMC or SMC, which, like the hardeners described in WO 2020 / 212258 A, give cured epoxy resins which combine a relatively long pot life with a low mix viscosity at room temperature (23 ° C) and have a high glass transition temperature and good mechanical properties, such as especially low brittleness, but at the same time allow relatively high curing rates at moderate curing temperatures, for example 50 to 120 ° C, in particular 60 to 100 ° C. Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to provide novel amino hardeners and corresponding epoxy resin compositions having improved curing speeds at moderate curing temperatures of 50-120° C., in particular 60-100° C., with simultaneously a relatively long pot life and low mixed viscosity at room temperature, in particular in the production of composites, in particular in large composites such as wind rotors. The compositions should preferably allow high glass transition temperatures and good mechanical properties (in particular low brittleness) of the cured resins, similar to compositions consisting of an epoxy resin and the cycloaliphatic amino hardener IPDA. [Means for solving the problem]

[0011] In the context of the present invention, novel epoxy resin compositions based on methyl-substituted alkylene amines as amino hardeners have been identified, which combine a pot life and viscosity at room temperature comparable to those of epoxy resin compositions based on the cycloaliphatic amino hardener IPDA, resulting in cured epoxy resins with similar glass transition temperatures and similarly good mechanical properties, but at the same time cure particularly rapidly at moderate curing temperatures of 50-120° C., in particular 60-100° C., and are therefore particularly well suited for the production of composites, in particular large composites. The amino hardeners of the present invention unexpectedly combine the rapid cure typical of aliphatic amines with the relatively long pot life and relatively high glass transition temperatures typical of cycloaliphatic amines.

[0012] Thus, the present invention relates to a compound of formula I, H2N(-Q-NH) n -A-NH-Q-NH2(I) (In the formula, n is 0 or 1, A is -CH2-CH(CH3)-CH2- or -CH2-CH2-CH(CH3)- or -CH(CH3)-CH2-CH2-, Each Q is independently -CH(CH3)-CH2- or -CH2-CH(CH3)-. The present invention relates to an aliphatic polyamine compound represented by the formula:

[0013] In the context of the present invention, the term polyamine refers to a compound having at least two primary or secondary amine functional groups.

[0014] In a preferred embodiment, the present invention provides an aliphatic polyamine of formula I, where n is 1, a first Q is -CH(CH3)-CH2-, and a second Q is -CH2-CH(CH3)-. The aliphatic polyamine has formula II: H2N-CH(CH3)-CH2-NH-A-NH-CH2-CH(CH3)-NH2(II) It is a compound of the formula:

[0015] When A=-CH2-CH(CH3)-CH2-, this gives the formula IIa: H2N-CH(CH3)-CH2-NH-CH2-CH(CH3)-CH2-NH-CH2-CH(CH3)-NH2(IIa) where A=-CH-CH-CH(CH)- or -CH(CH)-CH-CH-, this gives an aliphatic polyamine of formula IIb: An aliphatic polyamine of the formula H2N-CH(CH3)-CH2-NH-CH2-CH2-CH(CH3)-NH-CH2-CH(CH3)-NH-CH2-CH(CH3)-NH2(IIb) is obtained.

[0016] In another preferred embodiment, the present invention provides an aliphatic polyamine of formula I, where n is 0 and A is -CH2-CH(CH3)-CH2-. The aliphatic polyamine has formula III: H2N-CH2-CH(CH3)-CH2-NH-Q-NH2(III) It is a compound of the formula:

[0017] When Q=-CH(CH3)-CH2-, this gives the compound of formula IIIa: H2N-CH2-CH(CH3)-CH2-NH-CH(CH3)-CH2-NH2(IIIa) and When Q=-CH2-CH(CH3)-, this gives the compound of formula IIIb: H2N-CH2-CH(CH3)-CH2-NH-CH2-CH(CH3)-NH2(IIIb) The aliphatic polyamine is obtained.

[0018] The present invention also provides any mixture of two or more different aliphatic polyamines of formula I, in particular mixtures of aliphatic polyamines of formula IIa and formula IIb, and mixtures of aliphatic polyamines of formula IIIa and formula IIIb.

[0019] Experimental Amine Hardener Equivalent Weights (AHEWs) of the Aliphatic Polyamines of the Invention 実験的) is preferably in the range of 33 to 40 g / equivalent, more preferably 33 to 35 g / equivalent, for the aliphatic polyamine of formula II, and is preferably in the range of 29 to 35 g / equivalent, more preferably 29 to 31 g / equivalent, for the aliphatic polyamine of formula III.

[0020] The present invention also relates to an epoxy resin composition comprising at least one epoxy resin and a hardener component, characterized in that the hardener component comprises at least one aliphatic polyamine of formula I, in particular at least one aliphatic polyamine of formula II, i.e. an aliphatic polyamine of formula IIa or formula IIb or a mixture thereof, or at least one aliphatic polyamine of formula III, i.e. an aliphatic polyamine of formula IIIa or formula IIIb or a mixture thereof.

[0021] The epoxy resin according to the invention typically has 2 to 10, preferably 2 to 6, even more preferably 2 to 4, in particular 2 epoxy groups. The epoxy groups are in particular glycidyl ether groups formed by reaction of an alcohol group with epichlorohydrin. The epoxy resin generally has an average molecular weight (M n) or higher molecular weight compounds (polymers). Such polymeric epoxy resins preferably have a degree of oligomerization of 2 to 25 units, more preferably 2 to 10 units. The resins may be aliphatic or cycloaliphatic compounds or compounds with aromatic groups. In particular, epoxy resins are compounds having two aromatic or aliphatic six-membered rings or oligomers thereof. Industrially important epoxy resins are those which can be obtained by reaction of epichlorohydrin with compounds having at least two reactive hydrogen atoms, in particular with polyols. Of particular importance are epoxy resins which can be obtained by reaction of epichlorohydrin with compounds containing at least two, preferably two hydroxyl groups and two aromatic or aliphatic six-membered rings. Such compounds include, in particular, bisphenol A and bisphenol F, and also hydrogenated bisphenol A and bisphenol F, the corresponding epoxy resins being the diglycidyl ethers of bisphenol A or bisphenol F, or of hydrogenated bisphenol A or bisphenol F. The epoxy resin used according to the invention is typically bisphenol A diglycidyl ether (DGEBA). Suitable epoxy resins according to the invention also include tetraglycidyl methylene dianiline (TGMDA) and triglycidyl aminophenol or mixtures thereof. Also suitable are reaction products of epichlorohydrin with other phenols, for example cresol or phenol-formaldehyde adducts, especially phenol-aldehyde resins such as novolaks. Epoxy resins not derived from epichlorohydrin are also suitable. Examples of useful resins include epoxy resins that contain epoxy groups by reaction with glycidyl (meth)acrylate. According to the invention, it is preferred to use epoxy resins or mixtures thereof that are liquid at room temperature (23° C.). The epoxy equivalent weight (EEW) indicates the average mass of epoxy resin in g per mole of epoxy group.

[0022] The epoxy resin composition of the present invention preferably comprises at least about 50% by weight of an epoxy resin.

[0023] In certain embodiments, the epoxy resin composition of the present invention may further comprise a reactive diluent. In the context of the present invention, a reactive diluent is a compound that reduces the mixed viscosity (also the initial viscosity) of the epoxy resin composition and forms chemical bonds with the developing network of the epoxy resin and the hardener during the curing of the epoxy resin composition. In the context of the present invention, a preferred reactive diluent is a low molecular weight organic compound, preferably an aliphatic compound, that contains one or more epoxy groups.

[0024] The reactive diluent of the present invention is preferably selected from the group consisting of butane-1,4-diol diglycidyl ether, hexane-1,6-diol diglycidyl ether (HDDE), glycidyl neodecanoate, glycidyl versatate, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, p-tert-butyl glycidyl ether, butyl glycidyl ether, C8-C10-alkyl glycidyl ethers, C12-C14-alkyl glycidyl ethers, nonylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, phenyl glycidyl ether, o-cresyl glycidyl ether, polyoxypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether (TMP), glycerol triglycidyl ether, triglycidyl paraaminophenol (TGPAP), divinylbenzyl dioxide and dicyclopentadiene diepoxide. They are more preferably selected from the group consisting of butane-1,4-diol diglycidyl ether, hexane-1,6-diol diglycidyl ether (HDDE), 2-ethylhexyl glycidyl ether, C8-C10-alkyl glycidyl ethers, C12-C14-alkyl glycidyl ethers, neopentyl glycol diglycidyl ether, p-tert-butyl glycidyl ether, butyl glycidyl ether, nonylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, phenyl glycidyl ether, o-cresyl glycidyl ether, trimethylolpropane triglycidyl ether (TMP), glycerol triglycidyl ether, divinylbenzyl dioxide and dicyclopentadiene dipoxide. They are in particular selected from the group consisting of butane-1,4-diol diglycidyl ether, C8-C10-alkyl monoglycidyl ethers, C12-C14-alkyl monoglycidyl ethers, hexane-1,6-diol diglycidyl ether (HDDE), neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether (TMP), glycerol triglycidyl ether and dicyclopentadiene dipoxide.

[0025] The reactive diluent according to the invention preferably accounts for up to 30% by weight, more preferably up to 25% by weight, in particular from 1% to 20% by weight, based on the amount of epoxy resin.

[0026] The hardener component of the epoxy resin composition of the present invention may comprise additional aliphatic, cycloaliphatic and aromatic polyamines or additional primary monoamines. Examples of suitable additional aliphatic, cycloaliphatic or aromatic polyamines include disicane, dimethyl disicane (DMDC), isophorone diamine (IPDA), diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), bis(p-aminocyclohexyl)methane (PACM), methylene dianiline (e.g. 4,4'-methylene dianiline), polyetheramines such as D230 polyetheramine, D400 polyetheramine, D2000 polyetheramine or T403 polyetheramine, 4,9-dioxadodecane-1,12-diamine (DODA), 4,7,10-trioxatridecane-1,13-diamine (TTD), Versamid. Polyaminoamides such as 140, diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), toluene-2,4-diamine, toluene-2,6-diamine, 4-methylcyclohexane-1,3-diamine, 2-methylcyclohexane-1,3-diamine, mixture of 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine (MCDA), 1,2-diaminocyclohexane (DACH), 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene (DETDA), 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diamino Aminobenzene, diaminodiphenyl oxide, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenyl, 1,12-diaminodecane, 1,10-diaminodecane, 1,5-diaminopentane (cadaverine), propane-1,2-diamine, propane-1,3-diamine, 2,2'-oxybis(ethylamine), 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4-ethyl-4-methylamino-1-octylamine, ethylenediamine, hexamethylenediamine, menthanediamine, meta-xylylenediamine (MXDA), benzene-1,These include reaction products of 3-dimethanamine with styrene (Gaskamine® 240), N-(2-aminoethyl)piperazine (AEPIP), neopentanediamine, norbornanediamine, dimethylaminopropylaminopropylamine (DMAPAPA), octamethylenediamine, 4,8-diaminotricyclo[5.2.1.0]decane, trimethylhexamethylenediamine, and piperazine. Preferentially suitable as additional aliphatic, cycloaliphatic or aromatic polyamines are disicane, dimethyl disicane (DMDC), isophorone diamine (IPDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), bis(p-aminocyclohexyl)methane (PACM), polyetheramines such as, for example, D230 polyetheramine, D400 polyetheramine, D2000 polyetheramine or T403 polyetheramine, 4,9-dioxadodecane-1,12-diamine (DODA), 4,7,10-trioxatridecane-1,13-diamine (TTD), Versamid 140, 4-methylcyclohexane-1,3-diamine, 2-methylcyclohexane-1,3-diamine, mixtures of 4-methylcyclohexane-1,3-diamine and 2-methylcyclohexane-1,3-diamine (MCDA), 1,2-diaminocyclohexane (DACH), 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene (DETDA), 1,5-diaminopentane (cadaverine), meta-xylylenediamine (MXDA), reaction products of benzene-1,3-dimethanamine with styrene (Gaskamine® 240), N-(2-aminoethyl)piperazine (AEPIP) and dimethylaminopropylamine (DMAPAPA). Examples of suitable additional primary monoamines include dimethylaminopropylamine (DMAPA) and diethylaminopropylamine (DEAPA).

[0027] In certain embodiments, the aliphatic polyamine of the present invention comprises at least 50% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight, based on the total amount of hardener in the epoxy resin composition. In a preferred embodiment, the epoxy resin composition does not comprise an anhydride hardener. In certain embodiments, the epoxy resin composition does not comprise any additional hardener other than the aliphatic polyamine of the present invention.

[0028] In the context of the present invention, curing agents are understood to mean amino or anhydride curing agents. In the context of the present invention, amino curing agents are understood to mean amines with an NH functionality of ≧2 (so, for example, primary monoamines have an NH functionality of 2, primary diamines have an NH functionality of 4, and amines with three secondary amino groups have an NH functionality of 3). In the context of the present invention, anhydride curing agents are understood to mean intramolecular carboxylic acid anhydrides, for example 4-methyltetrahydrophthalic anhydride.

[0029] In the epoxy resin composition of the present invention, the epoxy compound (epoxy resin with any reactive diluent having epoxy groups) and the amino hardener are preferably used in an approximately stoichiometric ratio based on the epoxy groups and NH functionality. A particularly suitable ratio of epoxy groups to NH functionality is, for example, 1:0.8 to 1:1.2. Alternatively, in certain embodiments of the present invention, the epoxy compound (epoxy resin with any reactive diluent having epoxy groups) and the amino hardener are preferably used in an approximately stoichiometric ratio based on the epoxy groups and NH functionality. 実験的 Based on these, they are used in the epoxy resin composition of the present invention in an approximately equivalent ratio, preferably in a ratio ranging from 1:0.8 to 1:1.2.

[0030] In certain embodiments, the epoxy resin composition of the present invention may further comprise reinforcing fibers, including reinforcing fibers impregnated with the epoxy resin composition.

[0031] The reinforcing fibers of the present invention are preferably glass fibers, carbon fibers, aramid fibers or basalt fibers, or mixtures thereof. Particularly preferred are glass fibers and carbon fibers, especially glass fibers. The glass fibers used are typically E-glass fibers, but also R-glass, S-glass and T-glass fibers are used. The choice of the type of glass can affect the mechanical properties of the composite material. According to the present invention, the reinforcing fibers are used in the form of monofilaments, but preferably in the form of fiber filaments, fiber rovings, fiber mats or combinations thereof. It is particularly preferred to use the reinforcing fibers in the form of fiber rovings. The reinforcing fibers can take the form of, for example, short fiber sections having a length of a few mm to cm, or medium length fiber sections having a length of a few cm to a few m, or long fiber sections having a length in the range of several meters or more. According to the present invention, the reinforcing fibers are preferably used in the form of continuous fiber filaments, continuous fiber rovings or continuous fiber mats, especially for use in pultrusion or filament winding. In the context of the present invention, continuous fibre filaments, continuous fibre rovings or continuous fibre mats have a length of at least 10 m, preferably at least 100 m, in particular at least 200 m.

[0032] The epoxy resin composition of the present invention may contain further additives, such as inert diluents, curing accelerators, pigments, colorants, fillers, mold release agents, reinforcing agents, flow agents, defoamers, flame retardants or thickeners. Such additives are typically added in a functional amount, for example pigments are typically added in an amount that provides the desired color to the composition. The composition of the present invention typically contains 0% to 50% by weight, preferably 0% to 20% by weight, for example 2% to 20% by weight, based on the total of all additives based on the epoxy resin composition. In the context of the present invention, additives are understood to mean all additives to the epoxy resin composition that are neither epoxy compounds nor curing agents (amino and / or anhydride curing agents) nor reinforcing fibers.

[0033] The present invention further provides the use of an aliphatic polyamine of the present invention for curing an epoxy resin.

[0034] The present invention further provides a method for producing a cured material from the epoxy resin composition of the present invention. In such a method, the epoxy resin composition of the present invention is provided and then cured. For this purpose, the components of the epoxy resin composition are contacted with each other and then cured at a practical temperature for use. Typically, for a cured composite material, the epoxy compounds, the curing agent, and the additives (if present) of the epoxy resin composition are first contacted with each other and mixed, followed by contacting (impregnating or embedding) the reinforcing fibers and then curing at a practical temperature for use. The curing is preferably carried out at a temperature of at least 50°C, more preferably at least 60°C. The curing can be carried out at a temperature below 120°C, especially below 100°C, especially within the temperature range of 50 to 120°C, most preferably within the temperature range of 60 to 120°C. The curing is preferably carried out under normal pressure. Processes for producing cured composites include the curing of pre-impregnated fibers or fiber webs (e.g., prepreg curing, filament winding or pultrusion), and the production of composite parts by pouring or injection methods such as vacuum assisted resin transfer molding (VARTM), resin transfer molding (RTM), and also wet compression methods such as BMC (bulk mold compression) and SMC (sheet mold compression).

[0035] The present invention further provides a cured material obtainable or obtainable by curing the epoxy resin composition of the present invention, e.g. a cured composite material obtainable or obtainable by curing the epoxy resin composition of the present invention comprising reinforcing fibers. More specifically, the present invention provides a cured material or a cured composite material obtainable or obtainable by the method of the present invention for producing the cured material or the cured composite material, respectively. The cured material, e.g. the cured composite material, cured according to the present invention has a relatively high glass transition temperature T g has.

[0036] By the method of the invention, in particular by the pultrusion method of the invention and the filament winding method of the invention, it is possible to produce rebars. Such rebars are particularly weather resistant, whereas conventional rebars made of steel are prone to corrosion. The use of such rebars in concrete structures therefore allows the construction of structures with a particularly long life. Such rebars can be produced in any length and thickness, the rebars preferably having a length in the range of 0.5 to 50 m, in particular 1 to 20 m, and a thickness of 0.5 to 5 cm, in particular 1 to 3 cm. The cross section of such rebars can have any shape, which is preferably essentially rectangular or circular. Such rebars preferably have a surface profile, for example one or more grooves or ridges forming a spiral around the rebar, in order to improve the anchoring in the concrete. Such a surface profile can for example subsequently be machined into the already hardened rebar or can be applied by wrapping it with a corresponding impregnated reinforcing fiber material before hardening. Such rebars may also have an additional surface coating, for example of a further epoxy resin composition, to further protect the reinforcing fibers from weathering and chemical and thermal influences or to improve interaction with the concrete.

[0037] The present invention further relates to a process for producing a cyclopentadiene-based polymer comprising the steps of: [ka] to form a compound according to formula IV [ka] The present invention provides a method for producing an aliphatic polyamine of formula IIa, comprising forming a cyclic intermediate compound of formula IIa:

[0038] In a second step, this cyclic intermediate compound of formula IV is reacted with the cyclic intermediate compound of formula IV according to the following reaction scheme: [ka] with additional propane-1,2-diamine in the presence of hydrogen and a hydrogenation catalyst according to the formula IIa to form an aliphatic polyamine.

[0039] In the first step, propane-1,2-diamine is usually used in molar excess relative to methacrolein, usually in the range of 1.5 to 10 times, preferably in the range of 3 to 8 times. The preferred reaction temperature in the first step is in the range of 10 to 70 ° C, more preferably in the range of 20 to 50 ° C. The reaction mixture of the first step can be used in the second step without a purification step. In the second step, propane-1,2-diamine is usually used in molar excess relative to the cyclic intermediate compound of formula IV, usually in the range of 1.5 to 9 times, preferably in the range of 3 to 7 times. In the second step, a suitable amount of hydrogenation catalyst, preferably a heterogeneous hydrogenation catalyst, is added to the reaction mixture. Suitable hydrogenation catalysts are based on Co, Ni, Pt, Ru, Rh, Pd, and mixtures thereof. The catalytically active metals can be used in elemental form (such as, for example, Raney cobalt or Raney nickel) or in their oxidized form (oxide, chloride, nitrate, such as, for example, PtO2 (Adams catalyst)) and can be supported on a solid support selected from Al2O3, ZrO2, TiO2, SiO2, activated carbon and mixtures thereof (such as, for example, Ru / C or Co / Al2O3). Both fixed bed and suspension catalysts can be used. Particularly preferred is the use of hydrogenation catalysts having Pd as catalytically active metal on a support of activated carbon ("Pd / C"). Hydrogen for the hydrogenation is usually applied at a pressure in the range of 10 to 200 bar, preferably in the range of 20 to 100 bar. The preferred reaction temperature of the first step is in the range of 50 to 100 °C, more preferably in the range of 60 to 90 °C. The resulting aliphatic polyamine of formula IIa can be purified by fractional distillation, preferably after filtering off the catalyst and evaporating the remaining excess propane-1,2-diamine.

[0040] The present invention further relates to a process for the preparation of a methyl vinyl ketone-based ester having a carboxylic acid group, the carboxylic acid group being a carboxylic acid having a carboxylic acid group ... [ka] By reacting according to the formula V [ka] The present invention provides a method for producing an aliphatic polyamine of formula IIb, comprising forming a cyclic intermediate compound of formula IIb:

[0041] In a second step, this cyclic intermediate compound of formula V is reacted with the cyclic intermediate compound V according to the following reaction scheme: [ka] with additional propane-1,2-diamine in the presence of hydrogen and a hydrogenation catalyst according to the formula IIb to form an aliphatic polyamine.

[0042] In the first step, propane-1,2-diamine is usually used in molar excess relative to methyl vinyl ketone, usually in the range of 1.5 to 10 times, preferably in the range of 3 to 8 times. The preferred reaction temperature in the first step is in the range of 10 to 70 ° C, more preferably in the range of 20 to 50 ° C. The reaction mixture of the first step can be used in the second step without a purification step. In the second step, propane-1,2-diamine is usually used in molar excess relative to the cyclic intermediate compound of formula V, usually in the range of 1.5 to 9 times, preferably in the range of 3 to 7 times. In the second step, a suitable amount of hydrogenation catalyst, preferably a heterogeneous hydrogenation catalyst, is added to the reaction mixture. Suitable hydrogenation catalysts are based on Co, Ni, Pt, Ru, Rh, Pd, and mixtures thereof. The catalytically active metals can be used in elemental form (such as, for example, Raney cobalt or Raney nickel) or in their oxidized form (oxide, chloride, nitrate, such as, for example, PtO2 (Adams catalyst)) and can be supported on a solid support selected from Al2O3, ZrO2, TiO2, SiO2, activated carbon and mixtures thereof (such as, for example, Ru / C or Co / Al2O3). Both fixed bed and suspension catalysts can be used. Particularly preferred is the use of hydrogenation catalysts having Pd as catalytically active metal on a support of activated carbon ("Pd / C"). Hydrogen for the hydrogenation is usually applied at a pressure in the range of 10 to 200 bar, preferably in the range of 20 to 100 bar. The preferred reaction temperature of the first step is in the range of 50 to 100 °C, more preferably in the range of 60 to 90 °C. The resulting aliphatic polyamine of formula IIb can be purified by fractional distillation, preferably after filtering off the catalyst and evaporating any remaining excess propane-1,2-diamine.

[0043] The present invention further relates to a process for the preparation of a methacrylonitrile-based polymerizable compound having a structure similar to that described above, comprising reacting methacrylonitrile and propane-1,2-diamine in a first step according to the following reaction scheme: [ka] to form a compound according to formula VI. [ka] The present invention provides a method for producing aliphatic polyamines of formula IIIa and IIIb, comprising forming an intermediate nitrile compound of formula IIIa, IIIb, where Q=-CH(CH3)-CH2- or -CH2-CH(CH3)-.

[0044] In a second step, these intermediate nitrile compounds of formula VI are reacted with 1,2-dichlorophenyl nitriles according to the following reaction scheme: [ka] to form aliphatic polyamines of formula IIIa and IIIb. In the first step, propane-1,2-diamine is usually used in molar excess relative to methacrylonitrile, preferably in the range of 1.5 to 8 times, more preferably in the range of 2 to 5 times. The reaction in the first step is usually carried out under a pressure in the range of 5 to 200 bar, preferably in the range of 10 to 50 bar, using a gas that is inert under the given conditions, such as N2, Ar or H2, or a mixture thereof. The preferred reaction temperature in the first step is in the range of 120 to 220 ° C, more preferably in the range of 150 to 200 ° C. Before starting the second step, it is preferred to remove the remaining excess propane-1,2-diamine and other low boiling compounds from the intermediate nitrile compound of formula VI by distillation, preferably under reduced pressure. In the second step, an appropriate amount of a hydrogenation catalyst, preferably a heterogeneous hydrogenation catalyst, is added to the reaction mixture. Suitable hydrogenation catalysts are based on Co, Ni, Pt, Ru, Rh, Pd, and mixtures thereof. The catalytically active metals can be used in elemental form (such as Raney cobalt or Raney nickel) or in their oxidized form (oxides, chlorides, nitrates, such as PtO2 (Adams catalyst)) and can be supported on a solid support selected from Al2O3, ZrO2, TiO2, SiO2, activated carbon, and mixtures thereof (such as Ru / C or Co / Al2O3). Both fixed bed and suspension catalysts can be used. Hydrogen for the hydrogenation is usually applied at a pressure in the range of 50-300 bar, preferably in the range of 100-200 bar. The preferred reaction temperature of the second step is in the range of 60-150 °C, more preferably in the range of 80-120 °C. Preferably, the second step is carried out in the presence of ammonia, preferably in molar excess relative to the intermediate nitrile compound of formula VI, usually in the range of 2 to 20 times, preferably in the range of 2 to 15 times. The resulting aliphatic polyamines of formulae IIIa and IIIb can be purified by fractional distillation, preferably after filtering off the catalyst.

[0045] The gel time according to standard DIN 16 945 (1989) indicates the time between the addition of the curing agent to the reaction mixture and the transition of the reactive resin composition from the liquid state to the gel state. Temperature plays an important role, so the gel time is determined in each case at a given temperature. Dynamic mechanical methods, in particular rotational viscometry, allow even small samples to be analyzed quasi-isothermally and their entire viscosity / stiffness profile to be captured. According to standard ASTM D 4473-08 (2016), the crossing point between the storage modulus G' and the loss modulus G'' at which the damping tan δ has a value of 1 is the gel point, and the time from the addition of the curing agent to the reaction mixture until the gel point is reached is the gel time. Thus, a gel time determined at an elevated temperature (for example 90°C or 110°C) can be considered as a measure of the curing rate at such elevated temperature, whereas a gel time determined in this way at room temperature (23°C) can be considered as a measure of the handling time at such ambient temperature.

[0046] In order to determine the B time, which likewise serves as a measure of the curing speed, according to standard DIN EN ISO 8987 (2005), a sample (e.g. 0.5 g) of the freshly produced reactive resin composition is applied to a hot plate (e.g. a plate without a recess, e.g. 145° C.) and the time until threads are formed (gel point) or until sudden solidification (curing) is determined.

[0047] Glass transition temperature (T g ) can be determined using a differential scanning calorimeter (DSC), for example according to standard ASTM D 3418-15 (2015). This involves heating a very small amount of sample (e.g., about 10 mg) in an aluminum crucible (e.g., at 20 °C / min) and measuring the heat flow to a reference crucible. This cycle is repeated three times. The glass transition is determined from the second measurement or as the average of the second and third measurements. The T of the heat flow curve is g The process evaluation can be determined via the inflection point according to the half-width or midpoint temperature method.

[0048] Amine hydrogen equivalent weight (AHEW) can be determined theoretically or experimentally as described by B. Burton et al (Huntsman, “Epoxy Formulations using Jeffamine Polyetheramines”, Apr. 27, 2005, p. 8-11). The theoretically calculated AHEW is defined as the molecular weight of the amine divided by the number of available amine hydrogens (e.g., 2 for each primary amino group and 1 for each secondary amino group). For example, for IPDA with a molecular weight of 170.3 g / mol and two primary amino groups, i.e., four available amine hydrogens, the theoretically calculated AHEW is 170.3 / 4 g / eq = 42.6 g / eq. Experimental AHEW determination is based on the maximum heat distortion resistance (heat distortion temperature (HDT)) or maximum gas transition temperature (T g Therefore, to experimentally determine the AHEW, a mixture of a fixed amount of epoxy resin and various amounts of amino hardener is cured as completely as possible and its HDT or T is obtained. g is determined and the properties thus ascertained are plotted against the ratio of the starting materials. 実験的 ) is defined as follows: AHEW 実験的 =(AH 最大 *EEW エポキシ ) / ER, In the formula, AH 最大 = Maximum DT or T g Amount of Amino Hardener in grams E.E.W. エポキシ = EEW value of the epoxy resin used in the test ER = amount of epoxy resin used in the test (in grams)

[0049] In the context of the present invention, AHEW 実験的 is the maximum T g (measured by DSC according to standard ASTM D3418-15 (2015)) 実験的is particularly important when theoretically calculated AHEWs are not available, e.g., in the case of mixtures of polymeric amines.

[0050] The initial viscosity ("mixed viscosity") of the curable composition, for example the matrix component of the fiber-matrix composition of the invention, can be measured immediately after mixing the components according to standard DIN ISO 3219 (1993). The mixed viscosity is measured using a shear-controlled rheometer (for example MCR301 from Anton Paar) in a cone-plate configuration (for example cone and plate diameter: 50 mm, cone angle: 1°, gap width: 0.1 mm). The measurement temperature is an important factor in these measurements, since it has a significant effect on the viscosity and curing speed of the curable composition. Therefore, for comparison, the mixed viscosity needs to be determined at a specific temperature, for example room temperature (23°C).

[0051] The impact resistance of test specimens made of cured epoxy resins can be determined by Charpy notched bar impact tests at room temperature in accordance with standard DIN EN ISO 179-1 (2010). High impact resistance corresponds to low brittleness. EXAMPLES

[0052] Example 1a Synthesis of Aliphatic Polyamines of Formula IIa In the first step, 491.4 g (6.56 mol) of excess propane-1,2-diamine was added to 100.0 g (1.31 mol) of methacrolein at room temperature within 90 min. The temperature was kept constant in the range of 25-30 °C using an ice bath. The mixture was stirred for 1 h. This reaction step led to the formation of a cyclic intermediate compound of formula IV. The formation of this intermediate compound based on a seven-membered ring was confirmed by GC-MS analysis.

[0053] In the second step, the reaction mixture of the first step, still containing excess propane-1,2-diamine, was transferred to an autoclave. 20 g of Pd / C hydrogenation catalyst (5% Pd on activated carbon, Sigma Aldrich) was added. Subsequently, 10 bar of hydrogen was added, then the autoclave was heated to 80° C. within 15 minutes, and finally 50 bar of hydrogen was added. The mixture was stirred at a temperature of 80° C. for 24 hours, forming an aliphatic polyamine of formula IIa.

[0054] The catalyst was filtered off, the excess propane-1,2-diamine was evaporated in a rotavap at a temperature of 90° C. and the residue was subjected to distillation.

[0055] The above reaction was repeated and both samples were combined and distilled. The distillation was carried out under reduced pressure ranging from 1.7 to 2.1 mbar using a reflux ratio between 5:2 and 5:1. 244.5 g (1.21 mol, 46% yield, purity >99% GC) of aliphatic polyamine of formula IIa was obtained in the form of a colorless liquid with a boiling point of 117-119 °C (at 2.1 mbar). NMR analysis of the final product revealed a stereoisomeric mixture.

[0056] Example 1b Synthesis of Aliphatic Polyamines of Formula IIb In the first step, 467.3 g (6.24 mol) of excess propane-1,2-diamine was added to 100.0 g (1.25 mol) of methyl vinyl ketone within 53 minutes at room temperature. The temperature was kept constant in the range of 21-30 °C using an ice bath. The mixture was stirred for 1 h. This reaction step resulted in the formation of a cyclic intermediate compound of formula V. The formation of this intermediate compound based on a seven-membered ring was confirmed by GC-MS analysis. This reaction step was carried out twice.

[0057] In the second step, 56.7 g of the above reaction mixture of the first step, still containing excess propane-1,2-diamine, was transferred to a 150 ml autoclave. 2 g of Pd / C hydrogenation catalyst (5% Pd on activated carbon, Sigma Aldrich) was added. Subsequently, 10 bar of hydrogen was added, then the autoclave was heated to 80° C. within 15 minutes, and finally 50 bar of hydrogen was added. The mixture was stirred at a temperature of 80° C. for 12 hours, forming an aliphatic polyamine of formula IIb.

[0058] The catalyst was filtered off, the excess propane-1,2-diamine was evaporated on a rotary evaporator at a temperature of 60° C. and the residue was subjected to distillation.

[0059] The above second step was carried out a total of 20 times and all samples were combined and distilled.

[0060] The distillation was carried out at a reduced pressure of 1.8 mbar using a reflux ratio between 5:2 and 5:1. 33 g (purity >98% GC) of aliphatic polyamine of formula IIb in the form of a yellow liquid having a boiling point of 108.6° C. (1.8 mbar) were obtained. NMR analysis of the final product revealed a stereoisomeric mixture.

[0061] Example 1c Synthesis of Aliphatic Polyamine Mixtures of Formulae IIIa and IIIb The autoclave was charged with a mixture of methacrylonitrile (30 g, 0.45 mol) and propane-1,2-diamine (100 g, 1.35 mol). The autoclave was sealed, pressurized to 20 bar with H2 and heated to 170°C within 3 h. The mixture was stirred at 170°C overnight, cooled to ambient temperature and depressurized. The crude mixture contained about 50% propane-1,2-diamine, about 35% mixture of 3-((2-aminopropyl)amino)-2-methylpropanenitrile and 3-((1-aminopropan-2-yl)amino)-2-methylpropanenitrile, and about 5% other compounds by GC (GC area % values).

[0062] Five identical batches of crude reaction mixture were pooled and the propane-1,2-diamine was removed together with other light boilers by distillation under reduced pressure. The distillation sump (p=20 mbar, T サンプ、最大 = 85 °C) contained about 2% propane-1,2-diamine, about 89% mixture of 3-((2-aminopropyl)amino)-2-methylpropanenitrile and 3-((1-aminopropan-2-yl)amino)-2-methylpropanenitrile, and about 9% other compounds by GC (GC area % values). The mixture was used as is in the subsequent hydrogenation reaction.

[0063] The autoclave was charged with the crude sump product of the previous reaction step (50 g) and 5 g of Raney cobalt (washed with THF to remove water). The autoclave was sealed, pressurized to 10 bar with H2, and NH3 (40 g, 2.4 mol) was added. The reaction mixture was heated to 100°C and pressurized to 170 bar with H2. After 8 hours of reaction time, the mixture was cooled to ambient temperature, depressurized, and the Raney cobalt was removed by filtration. The crude mixture contained about 2% propylene-1,2-diamine, about 90% N 1 -(3-amino-2-methylpropyl)propane-1,2-diamine (compound of formula IIIb) and N 2 The mixture contained -(3-amino-2-methylpropyl)propane-1,2-diamine (compound of formula IIIa) and 8% of other compounds by GC (GC area % values, not including residual THF).

[0064] The crude reaction mixture of four identical batches was pooled and purified by distillation at 2 mbar. The mixture of 3-((2-aminopropyl)amino)-2-methylpropanenitrile and 3-((1-aminopropan-2-yl)amino)-2-methylpropanenitrile (113 g) was purified by tetrahydrofuran. 先端(head) = 58-62 ° C. The identity of the obtained compound was confirmed by GC-MS with a molecular weight of 145 g.

[0065] Example 2: Curing of epoxy resin with aliphatic polyamines The aliphatic polyamine from Example 1a, 1b or 1c and the epoxy resin (bisphenol A diglycidyl ether, Epilox A19-03, Leuna, EEW: 185 g / mol) were mixed in a stirrer system (1 min at 2000 rpm). DSC measurements (differential scanning calorimetry) and rheological analysis were carried out immediately after mixing. As a comparison, the corresponding compositions containing IPDA (Baxxodur® EC201, BASF), diethylenetriamine (DETA, BASF), dimethyldiethylenetriamine (DMDETA, prepared according to Example 1a of WO 2020 / 212258 A) and tetramethyltriethyltetramine (TMTETA, preparation of DMDETA according to Example 1a of WO 2020 / 212258 A also results in the formation of smaller amounts of the corresponding TMTETA, which is isolated from the reaction mixture by fractional distillation) were also tested.

[0066] Starting temperature (T o ), exothermic enthalpy (ΔH), and glass transition temperature (T g DSC analysis of the curing reaction of these mixtures to determine the T was carried out according to ASTM D 3418-15 (2015) using the following temperature profile: 0 °C → 20 K / min 200 °C → 10 min 200 °C. g was determined in the second run. The results are shown in Table 1.

[0067] Rheological measurements to investigate the reactivity profile (pot life and gel time) of epoxy resins with different amino hardeners were carried out at different temperatures on a shear-controlled plate-plate rheometer (MCR 301, Anton Paar) with a plate diameter of 15 mm and a gap of 0.25 mm. The gel time was determined by oscillation of the rheometer at 23 °C, 70 °C, 90 °C or 110 °C, by the intersection of the loss modulus (G'') and the storage modulus (G'), which gives the gel time according to standard ASTM D 4473-08 (2016). The gel time at 23 °C serves as a measure of the handling time at room temperature, while the gel time at 70 °C, 90 °C or 110 °C serves as a measure of the curing rate at higher temperatures. The mix viscosity (η o ) was measured at room temperature (23 °C) according to standard DIN ISO 3219 (1993) immediately after mixing the components using a rheometer (e.g. MCR 301 from Anton Paar) with controlled shear stress in a cone-plate configuration (e.g.: cone and plate diameter: 50 mm, cone angle: 1°, gap width: 0.1 mm). To determine the B-time, which also serves as a measure of the curing speed, a sample (approx. 0.5 g) of the freshly formed reactive resin composition was applied to a non-recessed plate at 145 °C and the time taken for the formation of fibers (gel point) and the time until rapid solidification (curing) were determined according to standard DIN EN ISO 8987 (2005). The results of the rheological measurements are summarized in Table 1.

[0068] Immediately after mixing the epoxy resin and amino hardener system, the mixture was degassed at 1 mbar and then cured (8 h at 60°C, then 4 h at 100°C, then 2 h at 160°C). After curing, the mechanical properties of the cured resins (tensile modulus (Et), tensile strength (σ-M), tensile elongation (ε-M), flexural modulus (Ef), flexural strength (σ-fM) and flexural elongation (ε-fM)) were determined at room temperature according to standards ISO 527-2:1993 and ISO 178:2006. The results are also shown in Table 1. The impact resistance was determined by Charpy notched bar impact testing at room temperature according to standard DIN EN ISO 179-1 (2010). High impact resistance corresponds to low brittleness.

[0069] [Table 1]

Claims

1. Formula I, H ２ N(-Q-NH) ｎ -A-NH-Q-NH ２ (I) (wherein n is 0 or 1; A is -CH ２ -CH(CH ３ )-CH ２ - or -CH ２ -CH ２ -CH(CH ３ ) - or -CH(CH ３ )-CH ２ -CH ２ - and Each Q is independently —CH(CH ３ )-CH ２ - or -CH ２ -CH(CH ３ ) - is) Aliphatic polyamines.

2. n and Q are such that the aliphatic polyamine is of formula II: H ２ N-CH(CH ３ )-CH ２ -NH-A-NH-CH ２ -CH(CH ３ )-NH ２ (II) 2. The aliphatic polyamine of claim 1 selected to have

3. A is -CH ２ -CH(CH ３ )-CH ２ The aliphatic polyamine according to claim 2, wherein

4. A is -CH ２ -CH ２ CH (CH ３ ) - or -CH(CH ３ )-CH ２ -CH ２ The aliphatic polyamine according to claim 2, wherein

5. n is 0 and A is —CH ２ -CH(CH ３ )-CH ２ The aliphatic polyamine according to claim 1, wherein

6. 10. An epoxy resin composition comprising at least one epoxy resin and a hardener component, wherein the hardener component comprises at least one aliphatic polyamine according to claim 1.

7. 7. The epoxy resin composition of claim 6, further comprising reinforcing fibers.

8. 10. Use of the aliphatic polyamines according to claim 1 for curing epoxy resins.

9. 10. A method of producing a cured material comprising providing the epoxy resin composition of claim 6 and then curing.

10. A hardened material obtainable by the method of claim 9.

11. In the first step, methacrolein is reacted with propane-1,2-diamine to form a compound of formula IV 【Chemistry 1】 forming a cyclic compound of 4. A method for producing the aliphatic polyamine of claim 3, characterized in that in a second step, the cyclic compound of formula IV is reacted with additional propane-1,2-diamine in the presence of hydrogen and a hydrogenation catalyst to form the aliphatic polyamine of claim 3.

12. In the first step, methyl vinyl ketone is reacted with propane-1,2-diamine to give a compound of formula V 【Chemistry 2】 forming a cyclic compound of 5. A method for producing the aliphatic polyamines of claim 4, characterized in that in a second step, the cyclic compound of formula V is reacted with additional propane-1,2-diamine in the presence of hydrogen and a hydrogenation catalyst to form the aliphatic polyamines of claim 4.

13. In the first step, methacrylonitrile is reacted with propane-1,2-diamine to form a compound of formula VI 【Transformation 3】 (where Q=-CH(CH ３ )-CH ２ - or -CH ２ -CH(CH ３ )-) nitrile, 6. A process for producing the aliphatic polyamine of claim 5, characterized in that in a second step, the nitrile of formula VI is hydrogenated in the presence of hydrogen and a hydrogenation catalyst to produce the aliphatic polyamine of claim 5.

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