Curing composition

Abstract

The present disclosure relates to a curing composition comprising: a) at least one carboxylic acid having 20-60 carbon atoms and at least two carboxyl groups and / or at least one ester derived from a carboxylic acid having 20-60 carbon atoms and at least two carboxyl groups; and a condensation product of at least one polyoxyalkylene amine, wherein the polyoxyalkylene amine comprises: I) at least two oxyalkylene moieties; and II) at least two primary amino groups; and b) at least one amine having at least one amino group. Also provided are an adhesive composition comprising the curing composition, a use of the adhesive, a wind turbine blade comprising the adhesive composition, and a method for manufacturing the curing composition.

Description

[0001] Public domain

[0002] The present disclosure relates to the field of polymer compositions, and in particular to curing compositions, and more particularly to curing compositions for epoxy resins.

[0003] background

[0004] The wind energy industry requires large wind turbine blades to generate electricity. Blades usually consist of two shells that are bonded together with a structural adhesive. Most often, epoxy resin adhesives are used as structural adhesives.

[0005] Many epoxy adhesives used in turbine blades are two-component adhesives that typically include a conventional epoxy resin or epoxy resin mixture, a curing agent and possibly a curing accelerator, and optionally a solvent or solvent mixture to adjust viscosity or solubility. Curing agents are ingredients or additives used to cure and harden various materials. These agents help to crosslink the components to aid hardening and provide strength to the product.

[0006] Epoxy curing agents are preferred for epoxy resins used to manufacture wind blades due to high sheer strength, compressive strength and light weight. The fatigue performance of epoxy curing agents improves the composite mechanical properties in rotor blades, thereby enhancing the performance of wind turbines.

[0007] As the demand for wind energy continues to grow, the size of turbine blades, especially those located offshore, is increasing significantly. Large blades may exceed 70 meters in length. The increased size of the blades results in an increased duration of the process of applying the epoxy adhesive to the blades. Sometimes, the epoxy adhesive may cure before the adhesive is fully applied. Premature curing causes difficulties in blade assembly.

[0008] In addition, the curing process is sometimes accompanied by a large release of heat. The exothermic effect may lead to a rapid increase in temperature and uncontrolled reactions between components within the adhesive composition, further damaging the finished product.

[0009] Therefore, the industry needs epoxy adhesives having an extended pot life and reduced exothermic effects during the curing process.

[0010] Overview

[0011] One object of the present disclosure is to provide a cured composition that, when combined with an epoxy resin, can form a two-component adhesive composition having a long pot life.

[0012] This object of the present disclosure is achieved by a curing composition comprising:

[0013] a) Condensation products of:

[0014] at least one carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups and / or at least one ester derived from a carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups; and

[0015] At least one polyoxyalkylene amine, wherein the polyoxyalkylene amine comprises:

[0016] I) at least two oxyalkylene moieties; and

[0017] II) at least two primary amino groups; and

[0018] b) at least one amine having at least one amino group.

[0019] Another object of the present disclosure is to provide an adhesive composition consisting of the curing composition of the present disclosure and an epoxy resin.

[0020] Another object of the present disclosure is to provide uses of the adhesive composition of the present disclosure.

[0021] Another object of the present disclosure is to provide a wind turbine blade comprising the adhesive composition of the present disclosure.

[0022] Yet another object of the present disclosure is to provide a method of making the cured composition.

[0023] Details

[0024] The following description is intended to be illustrative only and is not intended to limit the scope of the present disclosure.

[0025] [Polyoxyalkylene amine]

[0026] Polyoxyalkylene amines, sometimes called "polyetheramines" or "poly(alkyleneoxy)amines", are a class of organic amines having one or more amino groups attached to a polyether backbone. The amino groups include primary amino groups (-NH2), secondary amino groups (-NHR, where R is an organic group other than a H atom), and tertiary amino groups (-NR1R2, where R1 and R2 are independently organic groups other than a H atom).

[0027] The polyether backbone of the polyoxyalkylene amines used herein contains at least two oxyalkylene moieties (OC n H 2n, n is an integer from 2 to 10). In some preferred embodiments, the number of oxyalkylene moieties is greater than 2, such as 3, 4 or 5. The oxyalkylene moieties may preferably be selected from oxyethylene (-OCH2CH2-), oxypropylene (-OCH(CH3)CH2- or -OCH2CH2CH2-), oxybutylene (-OCH(CH3)CH(CH3)-, -OCH(CH2CH3)CH2- and -OC(CH3)2CH2-), or any other group having the chemical formula (OC n H 2n , n is an integer from 2 to 10). The oxyalkylene moieties may preferably be the same or different, for example a mixture of oxyethylene and oxypropylene.

[0028] The polyoxyalkylene amine used in the present disclosure has at least two primary amino groups, such as Jeffamine® D series polyetheramines. In some preferred embodiments, the polyoxyalkylene amine has three or more primary amino groups, such as Jeffamine® T series polyetheramines can be used.

[0029] In some preferred embodiments, the polyoxyalkylene amine comprises a polyoxyethylene amine having the formula:

[0030] H2NCH2CH2[OCH2CH2] x NH2

[0031] wherein x is an integer from 2 to 70. Specific examples are the Jeffamine® EDR series of diamines from Huntsman Corporation.

[0032] In some preferred embodiments, the polyoxyalkylene amine comprises a polyoxypropylene amine having the formula:

[0033] H2NCH(CH3)CH2[OCH2CH(CH3)] x NH2

[0034] wherein x is an integer from 2 to 70. Specific examples are the Jeffamine® D series diamines from Huntsman Corporation.

[0035] In some preferred embodiments, the polyoxyalkylene amine comprises a polyoxybutylene amine having the formula:

[0036] H2NCH(CH2CH3)CH2[OCH2CH(CH2CH3)] x NH2

[0037] wherein x is an integer from 2 to 70.

[0038] In some preferred embodiments, the polyoxyalkylene amine comprises a polyoxybutylene amine having the formula:

[0039] H2NCH(CH3)CH(CH3)[OCH(CH3)CH(CH3)] x NH2

[0040] wherein x is an integer from 2 to 70.

[0041] In some preferred embodiments, the polyoxyalkylene amine comprises a poly(oxypropylene-co-oxyethylene)amine having the formula:

[0042] H2NCH2CH2[OCH2CH2] x [OCH2CH(CH3)] y NH2

[0043] wherein x and y are independently integers ranging from 2 to 70.

[0044] In some preferred embodiments, the polyoxyalkylene amine comprises a poly(oxypropylene-co-oxyethylene)amine having the formula:

[0045] H2NCH2CH2[OCH2CH2] x [OCH2CH(CH3)] y [OCH2CH2] z NH2

[0046] wherein x, y and z are independently integers from 2 to 70.

[0047] In some preferred embodiments, the polyoxyalkylene amine comprises a poly(oxypropylene-co-oxyethylene)amine having the formula:

[0048] H2NCH(CH3)CH2[OCH2CH(CH3)] x [OCH2CH2] y [OCH2CH2] z NH2

[0049] wherein x, y and z are independently integers from 2 to 70. Specific examples are Jeffamine® HK511 diamine (prepared by amination of diethylene glycol grafted with propylene oxide, average molar mass 220) or Jeffamine® ED series diamines from Huntsman Corporation.

[0050] In some preferred embodiments, the polyoxyalkylene amines are based on copolymers of poly(tetramethylene ether) glycol and polypropylene glycol, for example, having the formula:

[0051] H2NCH(CH3)CH2[O(CH2)4] x OCH(CH3)CH2NH2

[0052] wherein x is an integer from 1 to 70. Specific examples are the Jeffamine® THF series of diamines from Huntsman Corporation.

[0053] In some preferred embodiments, the polyoxyalkylene amine comprises a poly(oxypropylene-co-oxyethylene)amine having the formula:

[0054] H2N(CH2)3[OCH2CH2] x O(CH2)3NH2

[0055] wherein x is an integer from 1 to 70. Specific examples are 1,13-diamino-4,7,10-trioxatridecane (Ancamine® 1922A from Evonik Resource Efficiency GmbH) or 4,7-dioxadecane-1,10-diamine.

[0056] In some preferred embodiments, the polyoxyalkylene amine comprises a polyoxypropylene amine having the formula:

[0057]

[0058] wherein R is a group selected from H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2; n is 0 or 1; x, y and z are independently integers from 1 to 30; and the sum of x, y and z is from 3 to 90. Specific examples are the Jeffamine® T series triamines from Huntsman Corporation.

[0059] It is to be appreciated that the polyoxyalkylene amines used in the present disclosure may be a mixture of polymers or oligomers having different degrees of polymerization. For example, when polyoxypropylene amines such as H2NCH(CH3)CH2[OCH2CH(CH3)] are used, x The repeating number x in NH2 may be within a certain distribution, for example, a distribution from 2 to 30, rather than a specific integer.

[0060] In some preferred embodiments, diamines, triamines or tetraamines having a primary amino-terminated polyoxyalkylene backbone may be used. Specific examples include Jeffamine® RFD270 amine from Huntsman Corporation, which contains a rigid alicyclic segment and a flexible polyetheramine segment in the same molecule. Mention may also be made of Jeffamine® XTJ616 from Huntsman Corporation, which contains a polyetheramine based on pentaerythritol and propylene oxide with an average molecular weight of about 660.

[0061] The polyoxyalkylene amines mentioned above are commercially available from various chemical manufacturers. For example, Jeffamine® D230, Jeffamine® D400, Jeffamine® D2000, Jeffamine® D4000, Jeffamine® ED600, Jeffamine® ED900, Jeffamine® ED2003, Jeffamine® EDR104, Jeffamine® EDR148, Jeffamine® EDR176, Jeffamine® from Huntsman Corporation EDR192, Jeffamine® THF100, Jeffamine® THF140, Jeffamine® THF170, Jeffamine® T403, Jeffamine® T3000, Jeffamine® T5000, Jeffamine® RFD270, Jeffamine® XTJ616; Baxxodur® EC 301, Baxxodur® EC 310, Baxxodur® EC from BASF SE 302. Baxxodur® EC 303, Baxxodur® EC 311; or Ancamine® 1922A from Evonik Resource Efficiency GmbH.

[0062] [carboxylic acid]

[0063] One or more carboxylic acids having 20-60 carbon atoms and at least two carboxyl groups are used in the present disclosure. Preferably, the carboxylic acid is in the form of a dimerized fatty acid. However, it will be appreciated that higher oligomeric fatty acids such as trimers and tetramers may be used as carboxylic acids. Other polycarboxylic acids may also be used.

[0064] Additionally or alternatively, one or more esters derived from carboxylic acids having 20-60 carbon atoms and at least two carboxyl groups may be used. Preferred are C1 to C4 alkyl esters.

[0065] The term dimer fatty acid or dimer fatty acid is well known in the art and refers to the dimerization product of monounsaturated or polyunsaturated fatty acids and / or their esters. Preferred dimer fatty acids are dimers of C10 to C30, more preferably C12 to C24, particularly C14 to C22, and especially C16 to C20 alkyl chains. Particularly preferred dimer fatty acids include

[0066] Dimerization products of palmitoleic acid (C16), stearic acid (C18), oleic acid (C18), linoleic acid (C18), linolenic acid (C18), elaidic acid (C18), eicosapentaenoic acid (C20) or mixtures thereof. Dimerization products of unsaturated fatty acid mixtures obtained in the hydrolysis of natural fats and oils, such as sunflower oil, soybean oil, olive oil, rapeseed oil, cottonseed oil, jojoba oil and tall oil, may also be used. After dimerization, the mixture may be (partially or completely) hydrogenated to produce saturated dicarboxylic acids, tricarboxylic acids, etc.

[0067] Particularly preferred for the purposes of the present disclosure are dimerized fatty acids having a dimer content as determined by gas chromatography of 50 to 95% by weight, preferably 60 to 90% by weight; and a trimer and higher acid content of 3 to 40% by weight, preferably 5 to 20% by weight.

[0068] Preferred dimer fatty acids are those with a dimer acid range of 75% to 90% by weight. The dimer fatty acids mentioned above are available from chemical manufacturers. For example, Pripol® 1006, 1009, 1013, 1017, 1022, 1025 and 1029 dimer acids (Croda Coatings & Polymers), Empol® 1018 and 1019 (Cognis Corp.), Haridimer™ 250S (Harima MID, Inc.) and Unidyme® 18 and SYLVADYME™ T18 (Arizona Chemical Co.).

[0069] [Polyetheramide]

[0070] The term "polyetheramide" is used herein to denote a condensation product or a mixture of condensation products formed by the reaction between one or more carboxylic acids having 20 to 60 carbon atoms and at least two carboxyl groups and / or the corresponding esters and one or more polyoxyalkylene amines. When a mixture of carboxylic acids and polyoxyalkylene amines is heated, the mixture may undergo a condensation reaction and a mixture of polyetheramides may be produced.

[0071] The condensation reaction occurs by heating to a temperature of 120° C. to 280° C. The elevated temperature ensures that water, a byproduct of the condensation, can be removed from the mixture. The heating conditions are continued for 0.5 to 10 hours, preferably 1 to 5 hours. Preferably, the heating conditions are accompanied by vigorous stirring, for example, at 100 RPM, 150 RPM or 200 RPM stirring.

[0072] In order to prevent side reactions such as oxidation, it may be preferred to apply a non-oxidizing atmosphere during the condensation process. It may be preferred to form a non-oxidizing atmosphere by filling with nitrogen or any other inert or reducing gas, such as argon.

[0073] The stoichiometric ratio of carboxylic acid and / or ester to polyoxyalkylene amine in the present disclosure is preferably 0.01-0.8:1, more preferably 0.1-0.5:1, and more preferably 0.1-0.4:1.

[0074] The polyamide formed by the condensation reaction between the acid / ester and the polyamine under given conditions contains reactive primary and secondary amines in its molecule. Reactive primary and secondary amines are key to the curing of epoxy resins. In the present disclosure, polyoxyalkylene amines and carboxylic acids and / or corresponding esters having 20-60 carbon atoms and at least two carboxyl groups are used, thereby reducing the concentration or density of reactive groups in the entire molecule, so that the exothermic effect is reduced and the pot life is extended. It has been found that by controlling the stoichiometry and other conditions, the desired level or concentration of free or unreacted primary amino groups in the polyetheramide can be achieved.

[0075] [amine]

[0076] The amine used herein is an organic amine having at least one amino group. The amine is different from the polyoxyalkylene amine used to form the condensation product. Preferably, the amine is cyclic and has at least one carbon ring or a ring containing one or more heteroatoms (e.g., pyrrolidine, tetrahydrofuran, and piperidine). More preferably, the amine has at least two carbon rings or rings each containing one or more heteroatoms.

[0077] Preferably, the amine has at least two amino groups. Of the at least two amino groups, at least one is a primary amino group. In particular, amines having at least one primary amino group attached to the ring directly or indirectly (e.g. via a methylene moiety -CH2-) are preferred. The amine is preferably aliphatic or semi-aliphatic. However, araliphatic or aromatic amines may also be used.

[0078] Preferably, the amine comprises at least one five-membered or six-membered ring. Preferably, the amine comprises at least two five-membered or six-membered carbon rings. In some cases, the two six-membered carbon rings are connected via a methylene group (-CH2-).

[0079] The amine used in the curing composition according to the present disclosure may be a one-component system or a mixture of at least two amines.

[0080] Specifically, the amine preferably includes 1-aminopyrrolidine, 2-aminopyrrolidine, 3-aminopyrrolidine, 1,2-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, m-xylylenediamine (MXDA), p-xylylenediamine (PXDA), 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPD), 1-amino-1-methyl-4-(2-amino-2-propyl)cyclohexane, 3,3'- One or more compounds of dimethyl-4,4'-diaminodicyclohexylmethane (DMDC), 4,4'-(1-methylethylidene)bis[cyclohexylamine], 4,4'-ethylidenebis[cyclohexylamine], 4,4'-diaminodicyclohexylmethane, 2,4'-diaminodicyclohexylmethane, 2,2'-diaminodicyclohexylmethane (also known as PACM), or mixtures obtained by (complete or partial) hydrogenation of methylenedianiline, or dimethylenetris(cyclohexylamine), as follows:

[0081] , , , , , , , , , , , , , , , , , , or .

[0082] Other preferred amines include, alone or in mixtures, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 4-methyl-1,3-cyclohexanediamine, N-cyclohexyl-1,3-propylenediamine, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine), 3,3'-dimethylmethylenedicyclohexylamine, TCDdiamine (3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.02,6]decane), and the like.

[0083] In a preferred embodiment, 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine (AM-CPDA) as shown below may also be used.

[0084]

[0085] Some of the above mentioned amines are available from chemical manufacturers. For example, 1,2-diaminocyclohexane available as Ancamine® 1770; 3-aminomethyl-3,5,5-trimethylcyclohexylamine available as Vestamin® IPD; hydrogenated methylenedianiline available as Vestamin® PACM; 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine) available as Ancamine® 2049; mixed polycyclic aliphatic amines (MPCAs) available as Ancamine® 2168; all from Evonik Resource Efficiency GmbH. Commercially available amines also include Baxxodur® from BASF SE (EC 331, EC 252, EC 210, EC 201), EPIKURE® curing agents from Hexion Inc. (3300, 3370, 3378, 3380, 3381, 3382, 3383, 3387, 3388, 3389).

[0086] The amine used herein may preferably be a mixture of several stereoisomers, such as cis and trans isomers, or chiral isomers. The amine may also preferably be a mixture of amines with different chemical formulas, such as a mixture of Ancamine® 2049 and Ancamine® 2168.

[0087] The weight percentage of the amine in the curing composition is preferably 1-99 wt %, more preferably 1-90 wt %, still more preferably 1 to 45 wt %, still more preferably 5 to 35 wt %.

[0088] While not being bound by any theory, it is believed that the amino groups attached directly or indirectly to the ring contribute to the mechanical strength in the final adhesive composition. By incorporating amines into the curing composition, the glass transition temperature (T g ), and enhance bond strength. In addition, the amine can introduce high chemical resistance into the adhesive composition, which is very desirable in the wind energy industry.

[0089] [Epoxy resin]

[0090] The curing composition of the present disclosure can be used together with epoxy resins known in the art to form a two-component adhesive composition. In the present disclosure, the epoxy resin may preferably be a bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol A / F epoxy resin, a novolac epoxy resin, an alicyclic epoxy resin, a glycidylamine epoxy resin or a combination thereof. Preferably, bisphenol A or bisphenol F epoxy resins are used in the adhesive composition. Epoxy resins can be purchased from various chemical manufacturers, such as DER™ 331, 351 or 731 from DOW Chemical Company. Several epoxy compounds are also described, for example, in EP 675 185 A1.

[0091] Useful compounds are many compounds known for this purpose which contain more than one epoxy group, preferably two epoxy groups per molecule. These epoxy compounds may preferably be saturated or unsaturated. They are preferably aliphatic, alicyclic, aromatic or heterocyclic and have hydroxyl groups. They preferably contain substituents which do not cause any side reactions under the mixing or reaction conditions, such as alkyl or aryl substituents, ether moieties, etc. They are preferably glycidyl ethers derived from polyphenols, especially bisphenols and novolac resins and having a molar mass ("epoxy equivalent", "EV value") based on the number of epoxy groups ME between 100 and 1500 g / eq, especially between 150 and 250 g / eq.

[0092] Examples of polyphenols include, inter alia, resorcinol, hydroquinone, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), isomer mixtures of dihydroxydiphenylmethane (bisphenol F), 4,4′-dihydroxydiphenylcyclohexane, 4,4′-dihydroxy-3,3′-dimethyldiphenylpropane, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxybenzophenone, bis(4-hydroxyphenyl)-1,1-ethane, bis(4-hydroxyphenyl)-1,1-isobutane, 2,2-bis(4-hydroxy-tert-butylphenyl)propane, bis(2-hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene, tris(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, and chlorinated and brominated products of the above compounds, for example tetrabromobisphenol A. Very particular preference is given to using liquid diglycidyl ethers based on bisphenol A and bisphenol F having an epoxy equivalent of 150 to 200 g / eq. It is also possible to use polyglycidyl ethers of polyols, for example ethane-1,2-diol diglycidyl ether, propylene-1,2-diol diglycidyl ether, propylene-1,3-diol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether (including neopentyl glycol diglycidyl ether), hexanediol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, higher polyoxyalkylene glycol diglycidyl ethers, for example higher polyoxyethylene glycol diglycidyl ether and polyoxypropylene glycol diglycidyl ether, copolyoxyethylene glycol diglycidyl ether, polyoxytetramethylene glycol diglycidyl ether. ethers, polyglycidyl ethers of glycerol, polyglycidyl ethers of hexane-1,2,6-triol, polyglycidyl ethers of trimethylolpropane, polyglycidyl ethers of trimethylolethane, polyglycidyl ethers of pentaerythritol or polyglycidyl ethers of sorbitol, polyglycidyl ethers of alkoxylated polyols such as, in particular, glycerol, trimethylolpropane, pentaerythritol, diglycidyl ether of cyclohexanedimethanol, diglycidyl ether of bis(4-hydroxycyclohexyl)methane and diglycidyl ether of 2,2-bis(4-hydroxycyclohexyl)propane, polyglycidyl ethers of castor oil, triglycidyl tris(2-hydroxyethyl)isocyanurate.

[0093] Further useful components A) include poly(N-glycidyl) compounds obtainable by dehydrohalogenation of the reaction products of epichlorohydrin and amines, such as aniline, n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine or bis(4-methylaminophenyl)methane. The poly(N-glycidyl) compounds also include, in particular, triglycidyl isocyanurate, triglycidyl urea azoles and oligomers thereof, N,N'-diglycidyl derivatives of cycloalkylene ureas and diglycidyl derivatives of hydantoins.

[0094] Furthermore, it is also possible to use polyglycidyl esters of polycarboxylic acids obtained by reaction of epichlorohydrin or similar epoxides with aliphatic, cycloaliphatic or aromatic polycarboxylic acids, such as oxalic acid, succinic acid, adipic acid, glutaric acid, phthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, naphthalene-2,6-dicarboxylic acid and higher diglycidyl dicarboxylates, such as dimer or trimer linolenic acid. Examples are diglycidyl adipate, diglycidyl phthalate and diglycidyl hexahydrophthalate.

[0095] Glycidyl esters of unsaturated carboxylic acids and epoxidized esters of unsaturated alcohols or unsaturated carboxylic acids should also be mentioned. In addition to the polyglycidyl ethers, it is also possible to use small amounts of monoepoxides, such as methyl glycidyl ether, butyl glycidyl ether, allyl glycidyl ether, ethylhexyl glycidyl ether, long-chain aliphatic glycidyl ethers, such as cetyl glycidyl ether and stearyl glycidyl ether, monoglycidyl ethers of mixtures of higher isomeric alcohols, glycidyl ethers of mixtures of C12 to C13 alcohols, phenyl glycidyl ether, cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, p-octylphenyl glycidyl ether, p-phenylphenyl glycidyl ether, glycidyl ethers of alkoxylated lauryl alcohols, and monoepoxides, such as epoxidized monounsaturated hydrocarbons (butylene oxide, cyclohexene oxide, styrene oxide). Detailed lists of epoxy compounds can be found in the handbook "Epoxidverbindungen und Epoxidharze" [Epoxides and Epoxy Resins], AM Paquin, Springer Verlag, Berlin 1958, Chapter IV and Lee Neville, "Handbook of Epoxy Resins", 1967, Chapter 2.

[0096] Useful epoxy compounds preferably include glycidyl ethers and glycidyl esters, aliphatic epoxides, diglycidyl ethers based on bisphenol A and / or bisphenol F, and glycidyl methacrylate. Other examples of such epoxides are triglycidyl isocyanurate (TGIC, trade name: ARALDIT 810, Huntsman), a mixture of diglycidyl terephthalate and triglycidyl trimellitate (trade name: ARALDIT PT 910 and 912, Huntsman), glycidyl ester of tert-butyl carbonate (trade name: CARDURA E10, Shell), 3,4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (ECC), ethylhexyl glycidyl ether, butyl glycidyl ether, pentaerythritol tetraglycidyl ether (trade name: POLYPDX R16, UPPC AG) and other Polypox products with free epoxy groups. It is also possible to use mixtures of the mentioned epoxy compounds.

[0097] Particularly preferred epoxy components are polyepoxides based on bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, 4,4′-methylenebis[N,N-bis(2,3-epoxypropyl)aniline], hexanediol diglycidyl ether, butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, propane-1,2,3-triol triglycidyl ether, pentaerythritol tetraglycidyl ether and hexahydrophthalic acid diglycidyl ether.

[0098] It may also be preferred to use mixtures of these epoxy compounds in the epoxy resin in accordance with the present disclosure.

[0099] The epoxy resin may be in various forms, such as crystalline form, powdered form, semi-solid form, liquid form, etc. For the liquid form, the epoxy resin may be dissolved in a solvent, such as water. Preferably, the epoxy resin is in liquid form to facilitate the mixing process.

[0100] In the two-component adhesive composition, the mass ratio of the epoxy resin to the curing composition is preferably in the range of 1:3 to 10:1, more preferably in the range of 1:1 to 5:1, and even more preferably in the range of 2:1 to 3:1.

[0101] [additive]

[0102] In order to introduce more functions or features to meet industrial requirements, the curing composition may preferably include additives. Additives are understood to mean substances added to change the properties of the epoxy composition in the desired direction, for example, to match the viscosity, wetting properties, stability, reaction rate, foaming, storability or adhesion and use properties with the final application. For example, several additives are described in WO99 / 55772, pages 15-25 and in "Plastics Additives, R. Gächter and H. Muller, Hanser Publishers 1983".

[0103] Preferred additives may be selected from fillers, reinforcing agents, coupling agents, toughening agents, defoaming agents, dispersants, lubricants, colorants, marking materials, dyes, pigments, infrared absorbers, antistatic agents, anti-caking agents, nucleating agents, crystallization accelerators, crystallization retarders, conductive additives, carbon black, graphite, carbon nanotubes, graphene, desiccants, mold release agents, leveling aids, flame retardants, separating agents, fluorescent brighteners, rheological additives, photochromic additives, softeners, adhesion promoters, anti-drip agents, metallic pigments, stabilizers, metal glitters, metal coated particles, porosity inducers, plasticizers, glass fibers, nanoparticles, flow aids, and combinations thereof.

[0104] The additive preferably accounts for a proportion of not more than 90 wt %, preferably not more than 70 wt %, more preferably not more than 50 wt %, and even more preferably not more than 30 wt % relative to the total weight of the adhesive composition.

[0105] For example, light stabilizers, such as sterically hindered amines, or other auxiliaries as described, for example, in EP 669 353 may advantageously be added in a total amount of 0.05% to 5% by weight.

[0106] In order to produce the cured composition of the present disclosure, it is additionally possible to add additives such as leveling agents, for example polysiloxanes, or adhesion promoters, for example those based on acrylates. In addition, other components may also be present optionally. Additional adjuvants and additives used may be chain transfer agents, plasticizers, stabilizers and / or inhibitors.

[0107] In some cases, the curing composition may preferably include an antioxidant additive. The antioxidant may include one or more structural units selected from the group consisting of hindered phenols, sulfides or benzoates. In the case of hindered phenols, the two ortho hydrogens are replaced by non-hydrogen compounds preferably having at least 1 to 20, particularly preferably 3 to 15 carbon atoms and preferably branched. Benzoates preferably also have non-hydrogen substituents in the ortho position relative to the OH group and particularly preferably 1 to 20, more preferably 3 to 15 carbon atoms, preferably branched.

[0108] In yet another embodiment, if desired, it may be preferred to introduce one or more catalysts into the adhesive composition, preferably as part of the curing composition, to promote the reaction of the epoxy groups of the epoxy resin and the amine groups of the curing composition. Available catalysts that may be introduced into the adhesive composition include the Ancamide® products available from Evonik Resource Efficiency GmbH and the products sold as "Accelerators" available from Huntsman Corporation. An exemplary catalyst is the piperazine-based Accelerator 399 available from Huntsman Corporation. When used, such catalysts may preferably be included in an amount of 0 to about 10% by weight of the total adhesive composition.

[0109] Preferably, the curing composition according to the present disclosure consists of the components specified above.

[0110] [adhesive]

[0111] Based on the curing composition, a preferred adhesive composition can be developed. The adhesive composition comprises the curing composition according to the present disclosure and an epoxy resin.

[0112] The adhesive composition can be preferably used in various fields, including electrical equipment, sports equipment, optical equipment, hygiene and health care products, household equipment, communication technology, automotive technology, energy and drive technology, mechanical engineering and medical equipment.

[0113] In particular, turbine blades comprising the adhesive composition of the present disclosure may preferably be used in wind energy. Likewise, the use of the curing composition or adhesive composition of the present invention for producing wind turbine blades is particularly preferred.

[0114] The present disclosure is illustrated by the following Examples and Comparative Examples. Example

[0115] The following materials were used in the Reference, Examples (Example 1 and Example 2) and Comparative Examples (CE).

[0116] DER™ 331 Liquid Epoxy Resin from Dow Chemical Company is the liquid reaction product of epichlorohydrin and bisphenol A.

[0117] Viscosity was measured at 25°C by a Brookfield DV-II+Pro viscometer. Tensile strength and elongation were measured according to ISO 527-2. Glass transition temperature was tested using DSC according to ASTM E1356-08. Peak temperature and exothermic peak duration of 150 g of the mixture at 40°C ambient temperature were tested by a temperature recorder 2103R (Shanghai Yadu Electronic Technology Co., Ltd.). Exothermic peak duration was measured as the duration from the mixing of the epoxy resin and the curing composition to the moment when the mixture reached its peak temperature. Exothermic peak duration is used here to determine a rough estimate of the pot life.

[0118] The color of the cured compositions is graded in this disclosure using the Gardner Color scale as specified in ASTM D1544.

[0119] Example 1

[0120] 437.9 g (about 0.755 mol) of dimerized C18 fatty acid (Jiangsu Yonglin Chemical Oil Co., Ltd.) was added to a nitrogen-filled four-necked flask and mixed. The mixing speed was slower than 200 revolutions per minute (RPM). 1351.24 g (about 3.071 mol) of Jeffamine® T403 triamine (available from Huntsman Corporation) was slowly added to the four-necked flask. The system was then kept at 200°C for 2 hours, then cooled to 120°C and dried under vacuum. 440.49 g of Ancamine® 2168 (available from Evonik Resource Efficiency GmbH) was added to the flask and mixed for 1 hour, and the color of the cured composition was measured to be Gardner 10. The viscosity was 4391 mPa·s. Ancamine 2168 had a weight percentage of about 19.8% in the final cured composition.

[0121] 100 g of DER™ 331 and 50 g of the curing composition obtained in Example 1 were thoroughly mixed. The exothermic peak duration at an ambient temperature of 40°C was 112 minutes. The exothermic peak temperature was 121°C.

[0122] 100 g of DER™ 331 and 50 g of the curing composition obtained in Example 1 were mixed thoroughly and then prepared into dumbbell specimens. The curing condition was 75° C. for 5 hours. According to ISO 527-2, the tensile strength was 73 MPa and the elongation was 5.3%. The glass transition temperature was 81° C.

[0123] Example 2

[0124] 437.9 grams (about 0.755 moles) of dimerized C18 fatty acid were placed in a nitrogen-filled four-necked flask and mixed. The mixing speed was slower than 200 RPM. 737.0 grams (about 3.204 moles) of Jeffamine® D230 were slowly added to the four-necked flask. The system was then kept at 200°C for 2 hours. The system was cooled to 120°C and dried under vacuum. 491.8 grams of Ancamine® 2168 were added to the flask and mixed for another hour. The Example 2 cured composition was then obtained. The color of the cured composition was measured to be Gardner 9. The viscosity was 1941 mPa·s. Ancamine 2168 had a weight percentage of about 29.5% in the final cured composition.

[0125] 102 g of DER™ 331 and 48 g of the curing composition obtained in Example 2 were thoroughly mixed. The exothermic peak duration at an ambient temperature of 40° C. was 83 minutes. The exothermic peak temperature at an ambient temperature of 40° C. was 119° C.

[0126] 100 g of DER™ 331 and 47 g of the curing composition obtained in Example 2 were mixed thoroughly and then prepared into dumbbell specimens. The curing conditions were 75° C. for 5 hours. According to ISO 527-2, the tensile strength was 67 MPa and the elongation was 6.0%. The glass transition temperature was 75° C.

[0127] Comparative Example

[0128] 85 g of Jeffamine® T403 was placed in a nitrogen-filled four-necked flask and mixed. The mixing speed was slower than 200 RPM. 15 g of Vestamin® IPD was slowly added to the four-necked flask and mixed for 1 hour. A comparative curing composition was then obtained.

[0129] 108 g of DER™ 331 and 42 g of the curing composition obtained in the comparative example were thoroughly mixed. The exothermic peak duration at an ambient temperature of 40°C was 81 minutes. The exothermic peak temperature at an ambient temperature of 40°C was 157°C.

[0130] 100 g of DER™ 331 and 39 g of the curing composition obtained in the comparative example were thoroughly mixed, and then a dumbbell specimen was prepared. The curing condition was 75°C for 5 hours. According to ISO 527-2, the tensile strength was 69 MPa and the elongation was 4.2%. The glass transition temperature was 87°C.

[0131] Various aspects and embodiments are possible. A part of these aspects and embodiments is described herein. After reading this specification, the technical staff will recognize that these aspects and embodiments are only exemplary and do not limit the scope of the present disclosure. The embodiment may be according to any one or more embodiments listed below.

[0132] Implementation

[0133] [Implementation 1]

[0134] A curing composition comprising:

[0135] a) condensation products of at least one carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups and / or at least one ester derived from a carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups, and at least one polyoxyalkylene amine, wherein the polyoxyalkylene amine comprises:

[0136] I) at least two oxyalkylene moieties; and

[0137] II) at least two primary amino groups;

[0138] and

[0139] b) at least one amine having at least one amino group.

[0140] [Implementation 2]

[0141] According to the curing composition of embodiment 1, the carboxylic acid is a dimerized fatty acid.

[0142] [Implementation Plan 3]

[0143] The curing composition according to embodiment 1 or 2, wherein the amine is cyclic.

[0144] [Implementation 4]

[0145] The curing composition according to any of the preceding embodiments, wherein the amine has at least two amino groups.

[0146] [Implementation 5]

[0147] The curing composition according to any of the preceding embodiments, wherein the carboxylic acid is a dimeric C16-C20 fatty acid.

[0148] [Implementation Plan 6]

[0149] The cured composition according to any of the preceding embodiments, wherein the oxyalkylene moiety comprises at least one oxyethylene, oxypropylene, or oxybutylene moiety.

[0150] [Implementation Plan 7]

[0151] A cured composition according to any one of the preceding embodiments, wherein the polyoxyalkylene amine comprises , wherein x is an integer from 2 to 70.

[0152] [Implementation Plan 8]

[0153] The cured composition according to any of the preceding embodiments, wherein the polyoxyalkylene amine comprises three primary amino groups.

[0154] [Implementation Plan 9]

[0155] According to any one of the preceding embodiments, the curing composition, the polyoxyalkylene amine comprises , and among them

[0156] R is a group selected from H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2;

[0157] n is 0 or 1;

[0158] x, y and z are independently integers from 1 to 30; and

[0159] The sum of x, y and z is from 3 to 90.

[0160] [Implementation Plan 10]

[0161] The curing composition according to any one of the preceding embodiments, wherein the molar ratio of the carboxylic acid to the polyoxyalkylene amine is 0.01-0.8:1, preferably 0.1-0.5:1, more preferably 0.1-0.4:1.

[0162] [Implementation Plan 11]

[0163] The curing composition according to any one of the preceding embodiments, wherein the amine has a weight percentage of 1-99 wt %, preferably 1-90 wt %, more preferably 1-45 wt %, and even more preferably 5-35 wt % in the curing composition.

[0164] [Implementation Plan 12]

[0165] The curing composition according to any of the preceding embodiments, wherein the amine comprises at least one five-membered or six-membered ring.

[0166] [Implementation Plan 13]

[0167] The curing composition according to any one of the preceding embodiments, wherein the amine comprises one or more selected from the group consisting of

[0168] , , , , , , , , , , , , , , , , , , or .

[0169] [Implementation Plan 14]

[0170] The cured composition according to any of the preceding embodiments, further comprising one or more additives selected from fillers, reinforcing agents, coupling agents, toughening agents (toughness improvers), defoamers, dispersants, lubricants, colorants, marking materials, dyes, pigments, infrared absorbers, antistatic agents, anti-caking agents, nucleating agents, crystallization accelerators, crystallization retarders, conductive additives, carbon black, graphite, carbon nanotubes, graphene, desiccants, mold release agents, leveling aids, flame retardants, separating agents, fluorescent whitening agents, rheological additives, photochromic additives, softeners, adhesion promoters, anti-drip agents, metallic pigments, stabilizers, metal glitters, metal coated particles, porosity inducers, plasticizers, glass fibers, nanoparticles or flow aids.

[0171] [Implementation Plan 15]

[0172] The curing composition according to any of the preceding embodiments, wherein the one or more additives account for a proportion of no more than 90 wt %, preferably no more than 70 wt %, more preferably no more than 50 wt %, and even more preferably no more than 30 wt % relative to the total weight of the adhesive composition.

[0173] [Implementation Plan 16]

[0174] The curing composition according to any of the preceding embodiments, further comprising one or more catalysts.

[0175] [Implementation Plan 17]

[0176] An adhesive composition comprising the curing composition according to any one of the preceding embodiments and an epoxy resin.

[0177] [Implementation Plan 18]

[0178] Use of the adhesive composition according to embodiment 17 in one of the following fields: electrical equipment, sports equipment, optical equipment, hygiene and health products, household equipment, communication technology, automotive technology, energy and drive technology, mechanical engineering and medical equipment.

[0179] [Implementation Plan 19]

[0180] A wind turbine blade comprising the adhesive composition according to embodiment 17.

[0181] [Implementation Plan 20]

[0182] A method for making a cured composition, comprising:

[0183] 1) Heating

[0184] a) at least one carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups and / or at least one ester derived from a carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups; and

[0185] b) at least one polyoxyalkylene amine, wherein the polyoxyalkylene amine comprises at least one oxyalkylene moiety and at least two primary amino groups;

[0186] to a temperature of 120°C to 280°C for 0.5 to 10 hours; and

[0187] 2) mixing the condensation product with at least one amine.

[0188] [Implementation Plan 21]

[0189] A method according to embodiment 20, wherein the heating condition is under a non-oxidizing atmosphere.

[0190] [Implementation Plan 22]

[0191] The method according to embodiment 20 or 21, wherein the stoichiometric ratio of carboxylic acid to polyoxyalkylene amine is 0.01-0.8:1, preferably 0.01-0.5:1, more preferably 0.1-0.4:1 molar ratio.

[0192] The above description is given to enable those skilled in the art to make and use the present disclosure, and is provided in the context of the application and its requirements. Various modifications to the preferred embodiments are apparent to those skilled in the art, and the general principles specified herein may be applicable to other embodiments and applications without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the illustrated embodiments, but rather has the widest scope consistent with the principles and features disclosed herein. In this regard, broadly speaking, certain embodiments within the present disclosure may not show all the benefits of the present disclosure.

Claims

1. A curing composition comprising: a) condensation products of: at least one carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups, said carboxylic acid being a dimerized fatty acid; and at least one polyoxyalkylene amine, Wherein the polyoxyalkylene amine comprises wherein x is an integer from 2 to 70; or Wherein the polyoxyalkylene amine comprises And among them R is a group selected from H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2; n is 0 or 1; x, y and z are independently integers from 1 to 30; and The sum of x, y and z is 3 to 90; and b) at least one amine having at least one amino group, wherein the amine comprises one or more selected from the group consisting of The stoichiometric ratio of carboxylic acid to polyoxyalkylene amine is 0.01-0.8:

1.

2. A curing composition according to claim 1, wherein the carboxylic acid is a dimeric C16-C20 fatty acid.

3. The curing composition according to claim 1 or 2, wherein the molar ratio of the carboxylic acid to the polyoxyalkylene amine is 0.1-0.5:

1.

4. The curing composition according to claim 1 or 2, wherein the amine has a weight percentage of 1-99 weight % in the curing composition.

5. The curing composition according to claim 1 or 2, further comprising one or more additives selected from fillers, reinforcing agents, coupling agents, toughening agents, defoamers, dispersants, lubricants, colorants, marking materials, infrared absorbers, antistatic agents, anti-caking agents, nucleating agents, conductive additives, desiccants, mold release agents, leveling aids, flame retardants, release agents, rheological additives, photochromic additives, softeners, adhesion promoters, anti-drip agents, stabilizers, metallic glitter, metal-coated particles, void inducing agents, plasticizers or flow aids.

6. The curing composition according to claim 1 or 2, further comprising one or more additives selected from dyes, pigments, graphite, graphene, glass fibers or nanoparticles.

7. The curing composition according to claim 5, wherein the one or more additives account for a proportion of no more than 90% by weight relative to the total weight of the curing composition.

8. The curing composition according to claim 1 or 2, wherein the molar ratio of the carboxylic acid to the polyoxyalkylene amine is 0.1-0.4:

1.

9. The curing composition according to claim 1 or 2, wherein the amine has a weight percentage of 1-90 weight % in the curing composition.

10. The curing composition according to claim 1 or 2, wherein the amine has a weight percentage of 1-45 weight % in the curing composition.

11. The curing composition according to claim 1 or 2, wherein the amine has a weight percentage of 5-35 weight % in the curing composition.

12. The curing composition according to claim 5, wherein the one or more additives account for a proportion of no greater than 70% by weight relative to the total weight of the curing composition.

13. The curing composition according to claim 5, wherein the one or more additives account for a proportion of no more than 50% by weight relative to the total weight of the curing composition.

14. The curing composition according to claim 5, wherein the one or more additives account for a proportion of no more than 30% by weight relative to the total weight of the curing composition.

15. The curing composition according to claim 1 or 2, further comprising one or more catalysts.

16. The curing composition according to claim 1 or 2, further comprising one or more additives selected from the group consisting of a crystallization accelerator, a crystallization retarder, and a fluorescent brightener.

17. The curing composition according to claim 1 or 2, further comprising one or more additives selected from carbon black, carbon nanotubes, and metal pigments.

18. An adhesive composition comprising the curing composition according to any one of claims 1 to 17 and an epoxy resin.

19. Use of the adhesive composition according to claim 18 in one of the following fields: electrical equipment, sports equipment, optical equipment, hygiene and health care products, household equipment, communication technology, automotive technology, energy and drive technology, mechanical engineering and medical equipment.

20. A wind turbine blade comprising the adhesive composition according to claim 18.

21. A method for making a cured composition, comprising: 1) Heating a) at least one carboxylic acid having 20 to 60 carbon atoms and at least two carboxyl groups, wherein the carboxylic acid is a dimerized fatty acid; and b) at least one polyoxyalkylene amine, Wherein the polyoxyalkylene amine comprises wherein x is an integer from 2 to 70; or The polyoxyalkylene amines include And among them R is a group selected from H, CH3, CH2CH3, CH2CH2CH3 or CH(CH3)2; n is 0 or 1; x, y and z are independently integers from 1 to 30; and The sum of x, y and z is 3 to 90; to a temperature of 120°C to 280°C for 0.5 to 10 hours; and 2) mixing the product of step 1) with at least one amine, wherein the amine comprises one or more selected from the following The stoichiometric ratio of carboxylic acid to polyoxyalkylene amine is 0.01-0.8:

1.

22. The method according to claim 21, wherein the heating condition is under a non-oxidizing atmosphere.

23. The method according to claim 21 or 22, wherein the stoichiometric ratio of carboxylic acid to polyoxyalkylene amine is a molar ratio of 0.01 to 0.5:

1.

24. The method according to claim 21 or 22, wherein the stoichiometric ratio of carboxylic acid to polyoxyalkylene amine is a molar ratio of 0.1-0.4:1.

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