Two-component (2k) epoxy formulations

Abstract

The present invention relates to a two-component (2K) curable composition comprising: a first component comprising: a) at least one epoxy resin; and a second component comprising: b) a mixture of polyamines wherein each polyamine has at least two amine hydrogens reactive towards epoxy groups, the mixture comprising: b) i) m-xylenediamine (MXDA); and b) ii) at least one cycloaliphatic primary diamine; and / or b) iii) at least one aliphatic primary diamine compound, said compound further comprising one or more secondary amine groups; and c) at least one phenolic resin obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula Ra-(CHO) b in which: Ra is H, a C1-C18 alkyl group, a C2-C18 alkenyl group, a C6-C18 aryl group, a C7-C18 alkylaryl group, or a C7-C18 aralkyl group; and b is 1 or 2 wherein the curable composition is characterized in that the stoichiometric ratio of the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is from 0.5: 1 to 1.2: 1, preferably from 0.8: 1 to 1.0: 1.

Description

Technical Field

[0001] The present invention relates to a two-component (2K) curable composition based on epoxy resin. More particularly, the present invention relates to a low-toxicity two-component (2K) curable composition, characterized by comprising an epoxy resin in a first component and an amine-functional hardener or curing agent in a second component. Background Art

[0002] A wide range of applications of epoxy resins has been found, mainly based on the fact that a specific selection of resins, modifiers, and crosslinking agents (or curing agents) allows the properties of the cured epoxy resin to be adjusted to achieve specific performance characteristics.

[0003] This multifaceted applicability is recognized, and properly cured epoxy resins also have a variety of other properties, which particularly include: excellent chemical resistance, especially resistance to alkaline environments; high tensile strength and compressive strength; high fatigue strength; low cure shrinkage; the ability to cure within a certain temperature range; and electrical insulation properties and their retention after aging or environmental exposure.

[0004] Although reactive epoxy resin systems are known to have recognized benefits, they typically contain components that are classified and thus commercially labeled as: corrosive (C); toxic (T); highly toxic (T+); harmful (Xn); irritating (Xi); sensitizing; and / or dangerous. In the European Union countries, commercial epoxy resin systems are usually labeled with their trade names, the chemical names of the hazardous components of the formulation, hazard symbols, risk (R-) phrases, and safety (S-) phrases.

[0005] For reasons of environmental protection, safety, and industrial hygiene, it is important to develop reactive epoxy-containing formulations that do not require such labeling and exhibit a reduced likelihood of sensitization. However, such formulations should be developed without compromising the physico-chemical properties and technical processing conditions of the epoxy resin.

[0006] One known way to reduce the toxicity of epoxy-based compositions is to use Mannich bases as curing agents. For example, U.S. Patent No. 6,262,148 (Bender et al.) describes the use of phenalkamine based on cardanol and m-xylenediamine (MXDA) as a hardener for epoxy-based coatings. However, the production of such hardeners is complex, and it is considered that their viscosity is too high for good processability in coating applications without further dilution. Therefore, these difficulties have prompted research into alternative low-toxicity curing agents.

[0007] U.S. Patent No. 8,642,709 (Walter et al.) discloses a two-component (2K) composition comprising a first component and a second component, wherein:

[0008] i) The first component is a mixture of reactive epoxy resins, and based on the mass of all epoxy resins, the mixture comprises:

[0009] a) 30 - 45 wt% of a reaction product of epichlorohydrin and polypropylene glycol having an epoxy group with an epoxy equivalent weight of at least 250 g / eq;

[0010] b) 30 - 45 wt% of a reaction product of epichlorohydrin and a linear phenolic resin having an epoxy group with an epoxy equivalent weight of at least 175 g / eq;

[0011] c) 10 - 40 wt% of a reaction product of epichlorohydrin and bisphenol A having an epoxy group with an epoxy equivalent weight of at least 500 g / eq; and

[0012] d) Optionally present formulation ingredients; and

[0013] ii) The second component comprises at least one mercaptan group-containing hardener for epoxy resins.

[0014] U.S. Patent No. 11,053,346 (Gerber) describes a low-toxicity hardener for epoxy resins, the hardener comprising: a) an adduct (AD) obtained from the reaction of: i) at least one linear phenolic glycidyl ether having an average of 2.5 - 4 epoxy groups per molecule, with ii) an amine mixture comprising bis(6-aminohexyl)amine and at least one amine (A1) different from bis(6-aminohexyl)amine and having at least one primary amino group; and b) at least one other amine (A2) different from bis(6-aminohexyl)amine and having at least two amine hydrogens reactive with epoxy groups per molecule.

[0015] US20190177472 (Kasemi et al.) discloses a hardener for epoxy resins, which is alleged to be a low-odor, low-viscosity, low-toxicity curing agent and has a low tendency to form carbamates and a high reactivity with epoxy resins. The described hardener comprises: i) at least one amine of formula (I)

[0016]

[0017] wherein: A 1 is an alkylene group having 2 - 15 carbon atoms and not 1,2-propylene; R 1is a hydrogen radical, an alkyl radical having 1 to 8 carbon atoms, or a phenyl radical; X represents the same or different groups selected from a hydroxyl group, alkyl radicals, alkenyl radicals and alkoxy radicals each having 1 to 18 carbon atoms; m is 0 or 1 or 2; and n is 1, 2 or 3; and ii) at least one amine of formula (II)

[0018]

[0019] wherein: A 2 is an alkylene radical selected from 1,2-ethylene and 1,2-propylene; R 2 is hydrogen or methyl or phenyl; Q is a 5-membered, 6-membered or 7-membered cycloalkyl or aryl radical having 4 to 7 carbon atoms; Y represents the same or different groups selected from alkyl radicals, alkoxy radicals and dialkylamino radicals each having 1 to 18 carbon atoms; and p is 0, 1, 2 or 3.

[0020] It is considered that there is a need in the art to prepare alternative curable compositions which are based on epoxy resins and exhibit low toxicity, but whose cured products are not impaired in terms of their physico-chemical properties. Summary of the Invention

[0021] According to a first aspect of the present invention, there is provided a two-component (2K) curable composition comprising:

[0022] a first component comprising:

[0023] a) at least one epoxy resin; and

[0024] a second component comprising:

[0025] b) a polyamine mixture, wherein each polyamine has at least two amine hydrogens reactive towards epoxy groups, the polyamine mixture comprising:

[0026] b)i) m-xylene diamine (MXDA); and

[0027] b)ii) at least one alicyclic primary diamine; and / or

[0028] b)iii) at least one aliphatic primary diamine compound which further comprises one or more secondary amine groups; and

[0029] c) at least one phenolic resin which is obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula

[0030] R a -(CHO) b in which formula:

[0031] Ra is H, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 6 -C 18 aryl, C 7 -C 18 alkylaryl, or C 7 -C 18 aralkyl;

[0032] and

[0033] b is 1 or 2,

[0034] wherein the curable composition is characterized in that the stoichiometric ratio of all the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is 0.5:1 to 1.2:1, preferably 0.8:1 to 1.0:1.

[0035] For completeness, the polyamine mixture in the curing agent component may comprise either or both of the diamine compounds b)ii) and b)iii).

[0036] In an embodiment, the composition of component a) comprises at least one polyepoxide having an epoxy equivalent weight of 100 - 700 g / eq. In particular, component a) may comprise at least one polyepoxide selected from: glycidyl ethers of polyols; glycidyl ethers of polyphenols; glycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.

[0037] An effective composition has been obtained wherein component a) comprises at least one diepoxide having an epoxy equivalent weight less than 500 g / eq. In this case, it is particularly preferred that component a) comprises at least one diepoxide selected from: bisphenol A-based diglycidyl ether; hydrogenated bisphenol A-based diglycidyl ether; bisphenol F diglycidyl ether; and hydrogenated bisphenol F-based diglycidyl ether.

[0038] Supplementary to or independent of the preferred form of the epoxy resin a), preferably, within the polyamine mixture of the second component, both b)ii) said at least one alicyclic primary diamine and b)iii) said at least one aliphatic primary diamine compound are characterized by an amine hydrogen equivalent weight not exceeding 150 g / eq. In particular, good results have been obtained in the case where b)iii) said at least one aliphatic primary diamine compound is selected from the following substances: 3-(2-aminoethyl)aminopropylamine; triethylenetetramine (TETA); tetraethylenepentamine (TEPA); and pentaethylenehexamine (PEHA). It may be particularly preferred to have triethylenetetramine (TETA) present in the polyamine mixture of the second component.

[0039] In an embodiment, based on the weight of the composition, the two-component (2K) composition comprises 5-30 wt% of c) said at least one phenolic resin. Independently of or in addition to this statement, preferably, said at least one phenolic resin (c)) is obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula R a -(CHO) b wherein: R a is H, C 1 -C 8 alkyl, or C 2 -C 8 alkenyl; and b is 1 or 2. Desirably, said at least one phenolic compound comprises phenol or consists of phenol, and most desirably, component c) of the composition comprises a phenol-formaldehyde resin or consists of a phenol-formaldehyde resin.

[0040] The two-component (2K) composition of the present invention exhibits limited carcinogenicity and mutagenicity and has low toxicity and low repro-toxicity characteristics. In addition, the presence of the curing agent component m-xylene diamine (MXDA) provides aromatic rings to the backbone of the cured product and thus provides advantageous hardness, chemical resistance and heat resistance. The aromaticity also provides a viable glass transition temperature (Tg).

[0041] Without being bound by theory, one or more other diamine components of the polyamine mixture (i.e., b) ii) and / or b) iii)) maintain a very processable curing rate of the composition. The phenolic resin is believed to act as an effective diluent for MXDA and other polyamines.

[0042] According to a second aspect of the present invention, there is provided a cured product obtained from a two-component (2K) curable composition as defined above and in the appended claims. The present invention also provides the use of the cured reaction product as a coating, an adhesive, or a sealant.

[0043] Definition

[0044] Unless the context clearly dictates otherwise, the singular forms "a / an" and "the" as used herein include plural referents.

[0045] As used herein, the terms "comprising", "comprises", or "comprised of" are synonymous with "including", "includes", or "containing", are inclusive or open-ended, and do not exclude additional unrecited members, elements, or method steps. If used, the phrase "consisting of" is closed and excludes all additional elements. Additionally, the phrase "consisting essentially of" excludes additional essential elements, but allows the inclusion of non-essential elements that do not substantially change the nature of the invention.

[0046] When values, concentrations, dimensions, and other parameters are expressed in the form of ranges, preferred ranges, upper limit values, lower limit values, or preferred upper limit values and preferred lower limit values, it should be understood that any range obtainable by combining any upper limit value or preferred value with any lower limit value or preferred value is also expressly disclosed, regardless of whether the obtained range is explicitly mentioned in the context.

[0047] In addition, in accordance with standard understanding, a weight range expressed as "0 to x" or "0-x" clearly includes 0 weight %: the component defined by the range may not be present in the composition, or may be present in the composition in an amount up to x weight %.

[0048] The terms "preferred", "preferably", "desirably", "particularly", "in particular", and their synonyms are generally used herein to refer to embodiments of the present disclosure that may provide certain benefits in certain circumstances. However, the recitation of one or more preferred, preferable, desirable, or particular embodiments does not mean that other embodiments are not available, and is not intended to exclude those other embodiments from the scope of the present disclosure.

[0049] The word "may" used throughout this application is used in an allowed sense (i.e., meaning it is possible), rather than in a mandatory sense.

[0050] As used herein, room temperature is 23°C ± 2°C. As used herein, "ambient conditions" means the temperature and pressure of the environment in which the composition is located or the coating or the substrate of the coating is located.

[0051] The molecular weights mentioned in this specification can be measured by gel permeation chromatography (GPC) using polystyrene calibration standards, as carried out in accordance with ASTM 3536.

[0052] Unless otherwise specified, the viscosity of the coating compositions described herein is measured using a Brookfield viscometer under standard conditions of 25 °C and 50% relative humidity (RH). The calibration method, rotor type, and rotational speed of the Brookfield viscometer are selected according to the manufacturer's instructions to be suitable for the composition to be measured.

[0053] The term "acute toxicity" is defined in the European Chemicals Agency Guidance to Regulation (EC) No 1272 / 2008 on classification, labelling and packaging (CLP) of substances and mixtures, Version 5.0, 7:2017, as meaning those adverse reactions that occur after the oral or dermal administration of a single dose of a substance or mixture, or after the administration of multiple doses within 24 hours, or after an inhalation exposure of 4 hours. Based on numerical criteria expressed as (approximate) LD50 (oral, dermal) or LC50 (inhalation) values, chemicals can be assigned to one of five toxicity categories based on acute toxicity via the oral, dermal, or inhalation route. Where applicable, the formula provided in the above guidance for calculating acute toxicity estimate (ATE) values for mixtures of ingredients (ATE Mix )(including mixtures where the ATE of each component of the mixture is unknown) has been used.

[0054] As used herein, the term "equivalent (eq.)" refers to the relative number of reactive groups present in a reaction, as is customary in chemical notation.

[0055] As used herein, the term "monofunctional" means having one polymerizable moiety. As used herein, the term "polyfunctional" means having more than one polymerizable moiety.

[0056] As used herein, the term "equivalent (eq.)" refers to the relative number of reactive groups present in a reaction, as is customary in chemical notation.

[0057] As used herein, the term "equivalent weight" means the molecular weight divided by the number of functional groups involved. Thus, "epoxy equivalent weight" (EEW) means the weight (in g) of a resin containing one equivalent of epoxy groups. Similarly, "amine hydrogen equivalent weight" (AHEW) is the weight (in g) of an organic amine containing one amine hydrogen.

[0058] As used herein, the term "epoxide" refers to a compound characterized by the presence of at least one cyclic ether group, i.e., a compound in which an ether oxygen atom is connected to two adjacent carbon atoms to form a cyclic structure. This term is intended to include monoepoxides, polyepoxides (having two or more epoxy groups), and prepolymers capped with epoxy groups. The term "monoepoxide" is intended to mean an epoxide having one epoxy group. The term "polyepoxide" is intended to mean an epoxide having at least two epoxy groups. The term "diepoxide" is intended to mean an epoxide having two epoxy groups.

[0059] Epoxides can be unsubstituted, but can also be inertly substituted. Exemplary inert substituents include chlorine, bromine, fluorine, and phenyl.

[0060] As used herein, "(meth)acryloyl" is a shorthand term for "acryloyl" and / or "methacryloyl". Thus, the term "(meth)acrylamide" collectively refers to acrylamide and methacrylamide.

[0061] As used herein, "C 1 -C n alkyl" group refers to a monovalent group containing 1 - n carbon atoms, which is a group of an alkane and includes straight-chain and branched organic groups. Thus, "C 1 -C 18 alkyl" group refers to a monovalent group containing 1 - 18 carbon atoms, which is a group of an alkane and includes straight-chain and branched organic groups. Examples of alkyl groups include, but are not limited to: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; tert-butyl; n-pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In the present invention, such alkyl groups can be unsubstituted or can be substituted with one or more halogens. When applicable to a given moiety (R), the specification will indicate the tolerance for one or more non-halogen substituents in the alkyl group.

[0062] As used herein, the term "C 1 -C 18 hydroxyalkyl" refers to an HO-(alkyl) group having 1 - 18 carbon atoms, where the point of attachment of the substituent is through an oxygen atom and the alkyl group is as defined above.

[0063] "Alkoxy" refers to a monovalent group represented by -OA, where A is an alkyl group: non-limiting examples thereof are methoxy, ethoxy, and isopropoxy. As used herein, the term "C 1 -C 18"Alkoxyalkyl" means an alkyl group having an alkoxy substituent as defined above, and wherein the moiety (alkyl-O-alkyl) contains in total from 1 to 18 carbon atoms: such groups include methoxymethyl (-CH 2 OCH 3 ), 2-methoxyethyl (-CH 2 CH 2 OCH 3 ), and 2-ethoxyethyl. Similarly, as used herein, the term "C 7 -C 18 alkoxyaryl" means an aryl group having an alkoxy substituent as defined above, and wherein the moiety (aryl-O-alkyl) contains in total from 7 to 18 carbon atoms.

[0064] As used herein, the term "C 2 -C 4 alkylene" is defined as a saturated divalent hydrocarbon group having from 2 to 4 carbon atoms.

[0065] The term "C 3 -C 18 cycloalkyl" shall be understood to mean a saturated monocyclic or polycyclic hydrocarbon group having from 3 to 18 carbon atoms. In the present invention, such cycloalkyl groups may be unsubstituted or may be substituted by one or more halogens. When applicable to a given moiety (R), the specification will indicate the tolerance for one or more non-halogen substituents in the cycloalkyl group. Examples of cycloalkyl groups include: cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; adamantane; and norbornane.

[0066] As used herein, "C 2 -C 18 alkenyl" means a hydrocarbon group having from 2 to 18 carbon atoms and at least one ethylenically unsaturated unit. The alkenyl group may be straight-chain, branched, or cyclic, and may optionally be substituted by one or more halogens. When applicable to a given moiety (R), the specification will indicate the tolerance for one or more non-halogen substituents in the alkenyl group. As will be understood by those of ordinary skill in the art, the term "alkenyl" also includes groups having a "cis" configuration and a "trans" configuration, or alternatively an "E" configuration and a "Z" configuration. Examples of the C 2 -C 20 alkenyl include, but are not limited to: —CH═CH 2 ; —CH═CHCH 3 ; —CH 2 CH═CH 2 ; —C(═CH 2 )(CH 3 ); —CH═CHCH 2 CH 3; —CH 2 CH═CHCH 3 ; —CH 2 CH 2 CH═CH 2 ; —CH═C(CH 3 ) 2 ; —CH 2 C(═CH 2 )(CH 3 );—C(═CH 2 )CH 2 CH 3 ; —C(CH 3 )═CHCH 3 ; —C(CH 3 )CH═CH 2 ; —CH═CHCH 2 CH 2 CH 3 ; —CH 2 CH═CHCH 2 CH 3 ; —CH 2 CH 2 CH═CHCH 3 ; —CH 2 CH 2 CH 2 CH═CH 2 ; —C(═CH 2 )CH 2 CH 2 CH 3 ; —C(CH 3 )═CHCH 2 CH 3 ; —CH(CH 3 )CH═CHCH; —CH(CH 3 )CH 2 CH═CH 2 ; —CH 2 CH═C(CH 3 ) 2 ; 1-Cyclopenten-1-yl; 1-Cyclopenten-2-yl; 1-Cyclopenten-3-yl; 1-Cyclohexen-1-yl; 1-Cyclohexen-2-yl; and 1-Cyclohexen-3-yl.

[0067] As used herein, "C 6 -C 18The term "aryl" refers to monocyclic ring systems, bicyclic ring systems, and tricyclic ring systems, where the monocyclic ring system is aromatic, or at least one of the rings in the bicyclic or tricyclic ring system is aromatic. Bicyclic and tricyclic ring systems include benzo-fused 2-3 membered carbocyclic rings. In the present invention, such aryl may be unsubstituted or may be substituted with one or more halogens. When applicable to a given moiety (R), the specification will indicate the tolerance for one or more non-halogen substituents in the aryl. Exemplary aryl groups include: phenyl; (C 1 -C 4 )alkylphenyls such as tolyl and ethylphenyl; indenyl; naphthyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and anthracenyl. Additionally, phenyl is preferably noted.

[0068] As used herein, "alkylaryl" refers to an aryl group substituted with an alkyl group, both groups being as defined above. Further, as used herein, "aralkyl" means an alkyl group substituted with an aryl group as defined above.

[0069] As used herein, the term "hetero" refers to a group or moiety containing one or more heteroatoms (such as N, O, Si, and S). Thus, for example, "heterocyclic" refers to a cyclic group having, for example, N, O, Si, or S as part of the ring structure. "Heteroalkyl", "heterocycloalkyl", and "heteroaryl" moieties are alkyl, cycloalkyl, and aryl as defined above, respectively, containing N, O, Si, or S as part of their structure.

[0070] As used herein, the term "metal" refers to any type of metal, metal alloy, or mixture thereof.

[0071] As used herein, except where otherwise expressly stated, the term "catalytic amount" means a sub-stoichiometric amount of catalyst relative to the reactants.

[0072] As used herein, "primary amino" refers to an NH 2 group attached to an organic group, and "secondary amino" refers to an NH group attached to two organic groups, which may also together form part of a ring. Thus, the term "tertiary amine" refers to a nitrogen-containing moiety in which the nitrogen atom is not bonded to a hydrogen atom. In use, the term "amine hydrogen" refers to the hydrogen atoms of primary and secondary amino groups.

[0073] The term "meta-xylenediamine" is sometimes abbreviated herein as meta-xylenediamine (m-xylenediamine) or MXDA. According to IUPAC nomenclature, MXDA is 1,1'-(1,3-phenylene)bis(methanamine), and in each instance where meta-xylenediamine or MXDA is mentioned herein, this IUPAC name may be substituted.

[0074] As used herein, "anhydrous" means that the relevant composition contains less than 0.25% by weight of water. For example, the composition may contain less than 0.1% by weight of water or be completely free of water. The term "substantially solvent-free" should be similarly interpreted to mean that the relevant composition contains less than 0.25% by weight of solvent.

[0075] The compositions of the present invention may be defined herein as "substantially free" of certain compounds, elements, ions, or other similar components. The term "substantially free" is intended to mean that the compound, element, ion, or other similar component is not intentionally added to the composition and is present at most in trace amounts that do not (adversely) affect the desired properties of the composition. Exemplary trace amounts are less than 1000 ppm by weight of the composition. The term "substantially free" expressly encompasses those embodiments in which the specified compound, element, ion, or other similar component is completely absent from the composition or is not present in any amount measurable by techniques commonly used in the art. Detailed Description

[0076] First component

[0077] a) Epoxy compound

[0078] The first component of the two-component (2K) composition comprises a) at least one epoxy resin. Desirably, based on the weight of the composition, the two-component (2K) composition contains 20 - 60% by weight, preferably 25 - 50% by weight of a) the at least one epoxy resin.

[0079] The epoxy resins used herein may include monofunctional epoxy resins, multi-functional (multi- or poly-functional) epoxy resins, and combinations thereof. The epoxy resin may be a pure compound but may equally be a mixture of epoxy-functional compounds (including mixtures of compounds having different numbers of epoxy groups per molecule). The epoxy resin may be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic, or heterocyclic, and may be substituted. In addition, the epoxy resin may also be monomeric or polymeric.

[0080] Without wishing to limit the present invention, exemplary monocyclic epoxides include: alkylene oxides; epoxy-substituted alicyclic hydrocarbons such as cyclohexene oxide, vinylcyclohexene monoxide, (+)-cis-limonene oxide, (+)-cis,trans-limonene oxide, (-)-cis,trans-limonene oxide, cyclooctene oxide, cyclododecene oxide, and α-pinene oxide; epoxy-substituted aromatic hydrocarbons; monoepoxy-substituted alkyl ethers of monohydric alcohols or phenols such as glycidyl ethers of aliphatic, alicyclic, and aromatic alcohols; monoepoxy-substituted alkyl esters of monocarboxylic acids such as glycidyl esters of aliphatic, alicyclic, and aromatic monocarboxylic acids; monoepoxy-substituted alkyl esters of polycarboxylic acids in which one or more other carboxyl groups are esterified with alkanols; alkyl and alkenyl esters of epoxy-substituted monocarboxylic acids; epoxyalkyl ethers of polyhydric alcohols in which one or more other OH groups are esterified or etherified with carboxylic acids or alcohols; and monoesters of polyhydric alcohols and epoxy monocarboxylic acids in which one or more other OH groups are esterified or etherified with carboxylic acids or alcohols.

[0081] For example, the following glycidyl ethers may be mentioned as particularly suitable monocyclic epoxides for use herein: ethyl glycidyl ether; propyl glycidyl ether; pentyl glycidyl ether; hexyl glycidyl ether; cyclohexyl glycidyl ether; 2-ethylhexyl glycidyl ether; benzyl glycidyl ether; 4-tert-butylphenyl glycidyl ether; 2-chlorophenyl glycidyl ether; 4-chlorophenyl glycidyl ether; 4-bromophenyl glycidyl ether; 2,4,6-trichlorophenyl glycidyl ether; 2,4,6-tribromophenyl glycidyl ether; and pentafluorophenyl glycidyl ether. In particular, one or more glycidyl ethers selected from the following may be used: ethyl glycidyl ether; pentyl glycidyl ether; 2-ethylhexyl glycidyl ether; benzyl glycidyl ether; 4-tert-butylphenyl glycidyl ether; 2-chlorophenyl glycidyl ether; and 4-chlorophenyl glycidyl ether.

[0082] In an important embodiment, the monocyclic epoxide conforms to formula (III) below:

[0083]

[0084] wherein: R 2 , R 3 , R 4 and R 5 may be the same or different and are independently selected from hydrogen, halogen atoms, C 1 -C 8 alkyl, C 3 -C 10 cycloalkyl, C 2 -C 12 alkenyl, C 6 -C 18 aryl, or C 7 -C 18an aralkyl group, provided that R 3 and R 4 at least one of which is not hydrogen.

[0085] Preferably, R 2 , R 3 and R 5 are hydrogen, and R 4 is phenyl or C 1 -C 8 alkyl, more preferably C 1 -C 4 alkyl.

[0086] In view of this embodiment, exemplary monocyclic epoxides include: 1,2-epoxyhexane; 1,2-epoxyheptane; epoxydecane; butadiene monoxide; and isoprene monoxide.

[0087] In the present invention, mention is made of using at least one monocyclic epoxide selected from the following: (+)-cis-limonene oxide; (+)-cis,trans-limonene oxide; (-)-cis,trans-limonene oxide; cyclooctene oxide; and cyclododecene oxide.

[0088] Similarly, without wishing to limit the present invention, suitable polycyclic epoxides can be liquids, solids, or solutions in solvents. Additionally, such polycyclic epoxides should have an epoxy equivalent weight of 100 - 700 g / eq, for example 120 - 320 g / eq. Additionally, generally, bicyclic epoxides with an epoxy equivalent weight less than 500 g / eq or even less than 400 g / eq are preferred: this is mainly from a cost perspective, since in their production, lower molecular weight epoxy resins require more limited processing in purification.

[0089] As examples of the types or groups of polycyclic epoxides that can be polymerized in the present invention, mention may be made of: glycidyl ethers of polyols and polyphenols; glycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.

[0090] Suitable diglycidyl ether compounds can be aromatic, aliphatic, or cycloaliphatic in nature and can thus be derived from dihydric phenols and dihydric alcohols. Additionally, useful classes of such diglycidyl ethers are: diglycidyl ethers of aliphatic diols and cycloaliphatic diols (such as 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,12-dodecanediol, and cyclohexanedimethanol); bisphenol A-based diglycidyl ethers; epoxies based on bisphenol A epichlorohydrin; bisphenol F diglycidyl ether; diglycidyl terephthalate; diglycidyl ethers based on polyalkylene glycols, especially polypropylene glycol diglycidyl ether; and glycidyl ethers based on polycarbonate diols. Other suitable diepoxides that may also be mentioned include: diepoxides of bisunsaturated fatty acid C 1 -C 18 alkyl esters; diglycidyl esters of dimer acids; polybutadiene diglycidyl ether; and limonene diepoxide.

[0091] Additional exemplary polyepoxides useful in the present invention include: glycerol polyglycidyl ether; bis(2,3-epoxy-2-methylpropyl) ether; trimethylolethane triglycidyl ether; trimethylolpropane polyglycidyl ether; pentaerythritol polyglycidyl ether; diglycerol polyglycidyl ether; polyglycerol polyglycidyl ether; sorbitol polyglycidyl ether; propoxylated glycerol polyglycidyl ether; polyglycidyl ether of castor oil; epoxidized propylene glycol dioleate; 1,2-epoxytetradecane; and internally epoxidized 1,3-butadiene homopolymer.

[0092] Additionally, examples of highly preferred polyepoxides include: toughened epoxy resins available from Shell Chemical Company under the Heloxy TM Modifier numbers 32, 56, 67, 68, 69, 71, 84, 107, and 505; epoxy novolac resins such as those of the EPIKOTE TM and EPON TM series available from Hexion and DEN TM 438 available from Dow Chemical Company; bisphenol A epoxy resins such as DER TM 331 and DER TM 383; bisphenol F epoxy resins such as DER TM 354; bisphenol A / F epoxy resin blends such as DER TM 353; aliphatic glycidyl ethers such as DER TM 736; polypropylene glycol diglycidyl ether such as DER TM 732; solid bisphenol A epoxy resins such as DERTM 661 and DER TM 664UE; solutions of bisphenol A solid epoxy resins such as DER TM 671-X75; castor oil triglycidyl ether such as ERISYS TM GE-35H; polyglycerol-3 polyglycidyl ether such as ERISYS TM GE-38; sorbitol glycidyl ether such as ERISYS TM GE-60; and PolyBD 600, Poly BD 650, Vikoflex available from Elf Atochem TM 4050 and Vikoflex TM 5075

[0093] In addition to the foregoing, the composition may in certain embodiments further comprise a glycidoxyalkylalkoxysilane having the following formula:

[0094]

[0095] wherein: each R is independently selected from methyl or ethyl; and

[0096] n is from 1 to 10

[0097] Exemplary silanes include, but are not limited to: γ-glycidoxypropyltrimethoxysilane, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxymethyltrimethoxysilane, γ-glycidoxymethyltriethoxysilane, γ-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltriethoxysilane; and 8-glycidoxyoctyltrimethoxysilane. When present, the epoxy-functional silane should be less than 10 wt%, preferably less than 5 wt% or less than 2 wt% based on the total weight of the epoxide

[0098] The present invention does not exclude that the first component of the curable composition may further comprise one or more cyclic monomers selected from the following: oxetane; cyclic carbonate; cyclic anhydride; and lactone. The disclosures of the following citations may be instructive in disclosing suitable cyclic carbonate functional compounds: U.S. Patent No. 3,535,342; U.S. Patent No. 4,835,289; U.S. Patent No. 4,892,954; British Patent No. GB-A-1,485,925; and EP-A-0 119 840. However, such cyclic comonomers should be less than 10 wt%, preferably less than 7.5 wt% or less than 5 wt% based on the total weight of the epoxy-functional compounds in the first component

[0099] Second component

[0100] b) Reactant polyamine

[0101] The second component or curing agent component of the composition must contain b) i) m-xylenediamine (MXDA). The curing agent component further contains: b) ii) at least one alicyclic primary diamine; and / or b) iii) at least one aliphatic primary diamine compound which also contains one or more secondary amine groups. In an important embodiment, each of the at least one alicyclic primary diamine of b) ii) and the at least one aliphatic primary diamine compound of b) iii) is characterized by an amine hydrogen equivalent weight of not more than 150 g / eq.

[0102] Exemplary alicyclic primary diamines (b) ii)) that can be used alone or in combination include: 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, and 1,4-diaminocyclohexane; bis(4-aminocyclohexyl)methane (PACM); bis(4-amino-3,5-dimethylcyclohexyl)methane; 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophorone diamine, IPDA); 2-methyl-1,3-diaminocyclohexane and / or 4-methyl-1,3-diaminocyclohexane; 1,3-bis(aminomethyl)-cyclohexane; 2,5(2,6)-bis(aminomethyl)-bicyclo[2.2.1]heptane (norbornanediamine, NBDA); 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 -decane (TCD-diamine).

[0103] Exemplary aliphatic primary diamine compounds having secondary amine groups (b) iii)) that can be used alone or in combination include: triethylenetetramine (TETA); tetraethylenepentamine (TEPA); pentaethylenehexamine (PEHA); higher homologues of linear polyethylenamines, such as polyethylenepolyamines having 5-7 ethylenamine units (so-called "higher ethylenepolyamines", HEPA); products from the multiple cyanoethylation or cyanobutylation and subsequent hydrogenation of primary diamines and polyamines having at least two primary amine groups, such as dipropylenetriamine (DPTA), N-(2-aminoethyl)-1,3-propanediamine (N3-amine), N,N'-bis(3-aminopropyl)ethylenediamine (N4-amine), N,N'-bis(3-aminopropyl)-1,4-diaminobutane, N5-(3-aminopropyl)-2-methyl-1,5-pentanediamine, N3-(3-aminopentyl)-1,3-pentanediamine, N5-(3-amino-1-ethylpropyl)-2-methyl-1,5-pentanediamine, or N,N'-bis(3-amino-1-ethylpropyl)-2-methyl-1,5-pentanediamine.

[0104] According to a preferred embodiment, the aliphatic primary diamine compound (b) iii) is selected from: triethylenetetramine (TETA); tetraethylenepentamine (TEPA); and pentaethylenehexamine (PEHA).

[0105] As described above, when formulating a two-component (2K) curable composition, it must generally be characterized in that the stoichiometric ratio of the active hydrogen atoms of the second component to the epoxy groups of the first component (a) is from 0.5:1 to 1.2:1, for example from 0.8:1 to 1.0:1.

[0106] In addition to satisfying this equivalent ratio, in an embodiment, based on the total weight of the polyamine in the second component, the second component is further characterized by comprising:

[0107] 5-50% by weight, preferably 20-50% by weight of b) i) m-xylenediamine (MXDA);

[0108] 50-95% by weight, preferably 50-80% by weight of b) ii) the at least one alicyclic primary diamine.

[0109] In an alternative embodiment, based on the total weight of the polyamine in the second component, the second component is further characterized by comprising:

[0110] 5-50% by weight, preferably 20-50% by weight of b) i) m-xylenediamine (MXDA);

[0111] 50-95% by weight, preferably 50-80% by weight of b) iii) the at least one aliphatic primary diamine compound which further comprises one or more secondary amine groups.

[0112] In another alternative embodiment, based on the total weight of the polyamine in the second component, the second component is further characterized by comprising:

[0113] 5-50% by weight, preferably 20-50% by weight of b) i) m-xylenediamine (MXDA);

[0114] 25-90% by weight, preferably 25-40% by weight of b) ii) the at least one alicyclic primary diamine; and

[0115] 25-90% by weight, preferably 25-40% by weight of b) iii) the at least one aliphatic primary diamine compound which further comprises one or more secondary amine groups.

[0116] Subject to the equivalence of the active hydrogen and epoxy groups being satisfied as described above, it is not excluded that the curing agent component further comprises b)iv) at least one other polyamine having at least two amine hydrogens reactive towards epoxy groups. For the sake of completeness, the said other polyamine (b)iv)) is different from the compounds b)i) to b)iii) as described above. In particular, the at least one polyamine b)iv) having at least two amine hydrogens reactive towards epoxy groups should contain primary amine groups and / or secondary amine groups and have an amine hydrogen equivalent weight of not more than 150 g / eq, preferably not more than 125 g / eq, more preferably not more than 100 g / eq.

[0117] Exemplary other polyamines b)iv) that can be used alone or in combination include, but are not limited to, the following:

[0118] i) Aliphatic primary diamines, examples of which include the following: 2,2-dimethyl-1,3-propanediamine; 1,3-pentanediamine (DAMP); 1,5-pentanediamine; 1,5-diamino-2-methylpentane (MPMD); 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine); 1,6-hexanediamine (hexamethylenediamine, HMDA); 2,5-dimethyl-1,6-hexanediamine; 2,2,4-trimethylhexamethylenediamine and / or 2,4,4-trimethylhexamethylenediamine; 1,7-heptanediamine; 1,8-octanediamine; 1,9-nonanediamine; 1,10-decanediamine; 1,11-undecanediamine; 1,12-dodecanediamine.

[0119] ii) Polyamines containing tertiary amine groups and having two or three aliphatic primary amine groups, specific examples of which include: N,N'-bis(aminopropyl)-piperazine; tris(3-aminopropyl)amine; and products obtained from the double cyanethylation and subsequent reduction of fatty amines derived from natural fatty acids, such as N,N-bis(3-aminopropyl)tallow alkylamine, which can Y12D and YT (from Akzo Nobel) can be commercially obtained.

[0120] iii) Aliphatic primary polyamines containing ether groups, specific examples of which include: bis(2-aminoethyl)ether; 3,6-dioxaoctane-1,8-diamine; 4,7-dioxadecane-1,10-diamine; 4,9-dioxadodecane-1,12-diamine; 4,7,10-trioxatridecane-1,13-diamine and higher oligomers of these diamines; bis(3-aminopropyl)polytetrahydrofuran and other polytetrahydrofuran diamines; diamines containing alicyclic ether groups obtained from the propoxylation and subsequent amination of 1,4-dihydroxymethylcyclohexane, such as This material obtained commercially as RFD-270 (from Huntsman); polyoxyalkylene diamine or polyoxyalkylene triamine, which is obtained as the amination product of polyoxyalkylene diol and polyoxyalkylene triol, and can be obtained commercially under the name of (from Huntsman), under the name of polyetheramine (from BASF), or under the name of PC (from Nitroil). It may be noted that it is particularly preferred to use D-230, D-400, D-600, D-2000, D-4000, T-403, T-3000, T-5000, EDR-104, EDR-148 and EDR-176, as well as the corresponding amines from BASF or Nitroil.

[0122] iv) Polyamines having one primary amino group and at least one secondary amino group, and the following examples may be mentioned: N-butyl-1,2-ethylenediamine;

[0123] 4-aminomethyl-piperidine; N-methyl-1,3-propanediamine; N-cyclohexyl-1,3-propanediamine; products from the Michael-type addition reaction of aliphatic primary diamines with acrylonitrile, diesters of maleic acid, fumaric acid, citraconic acid, acrylic acid and methacrylic acid, acrylamides and methacrylamides, and diesters of itaconic acid in a 1:1 molar ratio; products from the partial reductive alkylation of primary polyamines with aldehydes or ketones, especially the N-monoalkylation products of the previously mentioned polyamines having two primary amine groups, in particular the N-monoalkylation products of 1,6-hexanediamine, 1,5-diamino-2-methylpentane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)benzene, BHMT, DETA, TETA, TEPA, DPTA, N3-amine and N4-amine, where the preferred alkyl groups are benzyl, isobutyl, hexyl and 2-ethylhexyl; and partially styrenated polyamines, such as those obtained commercially as 240 (from Mitsubishi Gas Chemical).

[0124] v) secondary diamines, and in particular N,N'-dialkylation products of the above-mentioned polyamines having two primary amine groups, especially 1,6-hexanediamine, 1,5-diamino-2-methylpentane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane,

[0125] N,N'-dialkylation products of 1,3-bis(aminomethyl)benzene, BHMT, DETA, TETA, TEPA, DPTA, N3-amine or N4-amine, wherein the preferred alkyl groups are 2-phenylethyl, benzyl, isobutyl, hexyl and 2-ethylhexyl.

[0126] vi) aromatic polyamines, among which may be mentioned: a mixture of 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine (obtained from Albermarle as 300); a mixture of 3,5-diethyl-2,4-toluenediamine and 3,5-diethyl-2,6-toluenediamine (DETDA); 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane (M-DEA); 3,3',5,5'-tetraethyl-2,2'-dichloro-4,4'-diaminodiphenylmethane (M-CDEA); 4,4'-diaminodiphenyl sulfone (DDS); 4-amino

[0127] -N-(4-aminophenyl)benzenesulfonamide; 1,3-propylene-bis(4-aminobenzoate); 1,4-butylene-bis(4-aminobenzoate); polyoxytetramethylene-bis(4-aminobenzoate) (obtained from Air Products as ); 1,2-bis(2-aminophenylthio)ethane, 2-methylpropyl-(4-chloro-3,5-diaminobenzoate); and tert-butyl-(4-chloro-3,5-diaminobenzoate).

[0128] vii) polyamide-type amines, among which representative members include reaction products of monocarboxylic acids or polycarboxylic acids or their esters or acid anhydrides (especially dimer fatty acids) with aliphatic, alicyclic or aromatic polyamines (e.g., polyalkyleneamines such as DETA or TETA). Commercially available polyamide-type amines include: 100, 125, 140 and 150 (from Cognis);

[0129] 223, 250 and 848 (from Huntsman); 3607 and 530 (from Huntsman); and

[0130] EH 651, EH 654, EH 655, EH 661, and EH 663 (from Cytec).

[0131] When present in the polyamine mixture, the additional polyamine b) iv) should provide less than 25%, preferably less than 20% or less than 10% of its total number of amine hydrogen atoms.

[0132] c) Phenolic resin

[0133] The second component of the composition of the present invention further comprises: c) at least one phenolic resin obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula R a -(CHO) b In the general formula:

[0134] R a is H, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 6 -C 18 aryl, C 7 -C 18 alkylaryl, or C 7 -C 18 aralkyl; and

[0135] b is 1 or 2.

[0136] Based on the weight of the composition, the composition should preferably contain 5 - 30% by weight, preferably 10 - 25% by weight of c) the at least one phenolic resin.

[0137] Regarding the one or more reactant aldehydes, preferably: R a is H, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 6 -C 18 aryl, C 7 -C 18 alkylaryl, or C 7 -C 18 aralkyl; and b is 1 or 2. Particularly preferably: R a is H or C 1 -C 8 alkyl or C 2 -C 8 alkenyl; and b is 1 or 2. It can be confirmed that the following selection is more particularly preferred: where R a is H or C 1 -C 4Alkyl or C 2 -C 4 alkenyl; and b is 1.

[0138] Exemplary reactant aldehydes that can react alone or in combination include: formaldehyde; acetaldehyde; propionaldehyde; butyraldehyde; prop-2-enal; (2E)-but-2-enal; glyoxal; 1,3-propanedial; 1,5-pentanedial; benzaldehyde; and 4-methylbenzaldehyde. It can be noted that formaldehyde is particularly preferably used.

[0139] The use of natural lignin and tannins as the at least one phenolic compound is not excluded. However, preferably, the at least one phenolic compound is selected from: phenol; hydroxy phenols; C 1 -C 6 alkoxyphenols; C 1 -C 12 alkylphenols; phenylphenols; hydroxy group containing polyphenylmethanes; and hydroxy naphthalenes. It can be mentioned that phenol is particularly preferably used as any reactant phenolic compound from which a phenolic resin is obtained, or more desirably as the sole reactant phenolic compound.

[0140] Exemplary hydroxy phenols are phenols substituted with one or more hydroxy groups, including but not limited to: resorcinol (benzene-1,3-diol), C 1 -C 6 alkylresorcinols; catechol (benzene-1,2-diol), C 1 -C 6 alkylcatechols, and hydroquinone (benzene-1,4-diol). Illustrative C 1 -C 6 alkoxyphenols are 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, 2-ethoxyphenol, and 4-ethoxyphenol. Exemplary C 1 -C 12 alkylphenols are 2-methylphenol, 3-methylphenol, 4-methylphenol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 4-tert-butylphenol, 4-isooctylphenol, and 4-nonylphenol. Exemplary phenylphenols are 2-phenylphenol and 4-phenylphenol. Illustrative hydroxy group containing polyphenylmethanes will generally have 1-4 hydroxy groups and particularly include bisphenols such as bisphenol A, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol C2, bisphenol E, bisphenol F, bisphenol G, bisphenol PH, bisphenol TMC, bisphenol Z, bisphenol M, bisphenol S, bisphenol P, and bisphenol FL. Exemplary hydroxy naphthalenes are 1-hydroxy naphthalene and 2-hydroxy naphthalene.

[0141] The conditions for the reaction of the at least one phenolic compound with the at least one aldehyde are not intended to be particularly limited. However, preferably, the reaction occurs under basic conditions, and the conditions are such that an aldehyde group (-CHO) is used in a stoichiometric excess relative to the hydroxyl group (-OH). In this embodiment, the ratio of the aldehyde group to the hydroxyl group should preferably be from 1.1:1 to 5:1, such as from 1.1:1 to 3:1.

[0142] The basic reaction conditions are established by adding a catalytic amount of a basic compound to the reactants. The amount of a suitable basic catalyst can be determined by a person of ordinary skill in the art: this amount can be initially added to the reactants, or the catalyst can be added incrementally or continuously over a defined period of time. Additionally, exemplary basic catalysts include: alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkaline earth metal carbonates; and amines.

[0143] For inclusion in the compositions of the present invention, preferably, based on the weight of the resin, the at least one phenolic resin has: a free aldehyde content of less than 1 wt%; and a free phenolic compound content of less than 1 wt%. More preferably, the at least one phenolic resin should be substantially free of free aldehyde and free phenolic compounds. The terms "free phenolic compound" and "free aldehyde" refer respectively to one or more phenolic compounds or one or more aldehydes that are not bound within the resin and can thus evaporate from the resin. The amount of residual phenolic compounds can be determined according to the method described in DIN EN ISO 8974:2002-09.

[0144] Additive and auxiliary component

[0145] The compositions obtained in the present invention will generally also contain auxiliaries and additives that can impart improved properties to these compositions. For example, the auxiliaries and additives can impart one or more of the following: improved elasticity; improved elastic recovery; faster curing time; and lower residual tack. Such auxiliaries and additives (which can independently be included in a single component or both components of a two-component (2K) composition) include: catalysts; plasticizers; stabilizers (including UV stabilizers); antioxidants; toughening agents; fillers; drying agents; adhesion promoters; fungicides; flame retardants; rheology aids; color pastes or colored pigments such as titanium dioxide, iron oxide, or carbon black; solvents; and / or non-reactive diluents.

[0146] For completeness, it should be noted that auxiliary materials and additives containing epoxy group-reactive groups are usually blended into the hardener component of a two-component (2K) composition. Materials containing epoxy groups or reactive towards one or more hardeners are usually formulated into the epoxy-containing component of a two-component (2K) composition. Non-reactive materials can be formulated into either or both of the first and second components.

[0147] Suitable catalysts are substances that promote the reaction between epoxy groups and amine groups. Without wishing to limit the catalysts for use in the present invention, the following suitable catalysts may be mentioned: i) acids or compounds hydrolysable to acids, in particular a) organic carboxylic acids such as acetic acid, benzoic acid, salicylic acid, 2-nitrobenzoic acid and lactic acid; b) organic sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid and 4-dodecylbenzenesulfonic acid; c) sulfonic acid esters; d) inorganic acids such as phosphoric acid; e) Lewis acid compounds such as BF 3 amine complexes, SbF 6 sulfonium compounds, bisarene iron complexes; f) Bronsted acid compounds such as pentafluoroantimonic acid complexes; and e) mixtures of the above acids and acid esters; ii) tertiary amines such as 1,4-diazabicyclo[2.2.2]octane, benzyldimethylamine, α-methylbenzyldimethylamine, triethanolamine, dimethylaminopropylamine, imidazoles (including N-methylimidazole, N-vinylimidazole and 1,2-dimethylimidazole) and salts of such tertiary amines; iii) quaternary ammonium salts such as benzyltrimethylammonium chloride; iv) amidines such as 1,8-diazabicyclo[5.4.0]undec-7-ene; v) guanidines such as 1,1,3,3-tetramethylguanidine; vi) bisphenols; vii) phenolic resins; viii) Mannich bases; and ix) phosphite esters such as diphenyl phosphite and triphenyl phosphite.

[0148] A "plasticizer" for the purposes of the present invention is a substance that reduces the viscosity of the composition and thus promotes its processability. Herein, based on the total weight of the composition, the plasticizer can be present up to 10 wt% or up to 5 wt%, and is preferably selected from: polydimethylsiloxane (PDMS); dicarbamates; monofunctional, linear or branched C 4 -C 16Ethers of alcohols, such as Cetiol OE (available from Cognis Deutschland GmbH, Düsseldorf); rosin acid esters, butyrate esters, thiobutyrate esters, acetate esters, propionate esters, and citrate esters; esters based on nitrocellulose and polyvinyl acetate; fatty acid esters; dicarboxylic acid esters; esters of fatty acids with OH groups or epoxidized fatty acids; glycolate esters; benzoate esters; phosphate esters; sulfonate esters; trimellitate esters; epoxidized plasticizers; polyether plasticizers, such as end-capped polyethylene glycol or polypropylene glycol; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. It should be noted that, in principle, phthalate esters can be used as plasticizers, but due to their toxicological potential, these are not preferred. Preferably, the plasticizer comprises one or more polydimethylsiloxanes (PDMS) or consists of one or more polydimethylsiloxanes (PDMS).

[0149] The "stabilizer" for the purposes of the present invention should be understood as an antioxidant, a UV stabilizer, or a hydrolysis stabilizer. Herein, based on the total weight of the composition, the stabilizer can total up to 10 wt% or up to 5 wt%. Standard commercial examples of stabilizers suitable herein include: sterically hindered phenols; thioethers; benzotriazoles; benzophenones; benzoate esters; cyanoacrylates; acrylate esters; amines of the hindered amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof.

[0150] The composition of the present invention can optionally comprise a toughening rubber in the form of core-shell particles dispersed in an epoxy resin matrix. The term "core-shell rubber" or CSR is used herein in its standard meaning in the art to denote a rubber particle core formed from a polymer comprising an elastomeric or rubber-like polymer as the main component, and a shell layer formed from a polymer graft-polymerized onto the core. The shell layer partially or completely covers the surface of the rubber particle core during the graft polymerization process. By weight, the core should account for at least 50 wt% of the core-shell rubber particles. The polymeric material of the core should have a glass transition temperature (T g ) not higher than 0 °C, preferably -20 °C or lower, more preferably -40 °C or lower, even more preferably -60 °C or lower. The polymer of the shell is a non-elastomeric, thermoplastic, or thermosetting polymer having a glass transition temperature (T g ) higher than room temperature, preferably higher than 30 °C, more preferably higher than 50 °C.

[0151] Without wishing to limit the invention, the core can consist of: homopolymers of dienes, such as homopolymers of butadiene or isoprene; copolymers of dienes, such as copolymers of butadiene or isoprene with one or more ethylenically unsaturated monomers (such as vinyl aromatic monomers, (meth)acrylonitrile or (meth)acrylate); polymers based on (meth)acrylate monomers, such as butyl acrylate; and polysiloxane elastomers, such as polydimethylsiloxane and crosslinked polydimethylsiloxane.

[0152] Similarly, without wishing to limit the invention, the shell can consist of a polymer or copolymer of one or more monomers selected from: (meth)acrylates, such as methyl methacrylate; vinyl aromatic monomers, such as styrene; vinyl cyanides, such as acrylonitrile; unsaturated acids and acid anhydrides, such as acrylic acid; and (meth)acrylamides. The polymer or copolymer used in the shell can have acid groups that are ionically crosslinked by forming metal carboxylates, in particular by forming salts of divalent metal cations. The shell polymer or copolymer can also be covalently crosslinked by monomers having two or more double bonds per molecule.

[0153] Preferably, any included core - shell rubber particles have an average particle size (d50) of 10 nm to 300 nm, such as 50 nm to 200 nm: the particle size refers to the diameter or the largest dimension of the particles in the particle distribution and is measured via dynamic light scattering.

[0154] This application does not exclude the situation where there are two types of core - shell rubber (CSR) particles with different particle sizes in the composition to provide a balance of the key properties (including shear strength, peel strength, and resin fracture toughness) of the resulting cured product. In this embodiment, the smaller particles (the first CSR type) contained can have an average particle size of 10 - 100 nm, and the larger particles (the second CSR type) contained can have an average particle size of 120 - 300 nm, such as 150 - 300 nm. Based on weight, the amount of the smaller core - shell rubber particles should generally exceed that of the larger particles: for example, a weight ratio of smaller CSR particles to larger CSR particles of 3:1 to 5:1 can be employed.

[0155] The core - shell rubber can be selected from commercially available products, examples of which include: Paraloid EXL 2650A, EXL 2655, and EXL 2691A available from The Dow Chemical Company; Kane MX series from Kaneka Corporation, especially MX 120, MX 125, MX 130, MX 136, MX 551, MX 553; and METABLEN SX - 006 available from Mitsubishi Rayon.

[0156] Based on the total weight of the composition, the core-shell rubber particles should be included in the composition in an amount of 0 - 10% by weight, for example 0 - 5% by weight.

[0157] As described above, the composition according to the invention may additionally comprise fillers. Suitable here are, for example, chalk, lime powder, precipitated silica and / or pyrogenic silica, zeolites, bentonite, magnesium carbonate, diatomaceous earth, alumina, clay, talc, titanium oxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass powder and other ground minerals. Organic fillers may also be used, in particular carbon black, graphite, wood fibres, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, chopped straw, husks, ground walnut shells and other chopped fibres. Short fibres such as glass fibres, glass filaments, polyacrylonitrile, carbon fibres, Kevlar fibres or polyethylene fibres may also be added. Aluminium powder is likewise suitable as a filler.

[0158] Also suitable as fillers are hollow spheres having a mineral or plastic shell. For example, these can be hollow glass spheres, which are commercially available under the trade name Glass and can be obtained commercially. Hollow spheres based on plastics (such as or ) can be used and are described in EP 0 520 426B1: they consist of an inorganic or organic substance and each have a diameter of 1 mm or less, preferably 500 μm or less.

[0159] Fillers which impart thixotropy to the composition may be preferred for many applications: such fillers are also described as rheological aids, for example hydrogenated castor oil, fatty acid amides, or expandable plastics (such as PVC).

[0160] Based on the total weight of the composition, the total amount of filler present in the composition according to the invention will preferably be 0 - 30% by weight, more preferably 0 - 20% by weight. The desired viscosity of the curable composition will generally be determined by the total amount of filler added, and it is considered that, in order to be easily extrudable from a suitable dispensing device (such as a tube), the curable composition should have a viscosity of 3000 - 150000 mPa·s, preferably 40000 - 80000 mPa·s, or even 50000 - 60000 mPa·s.

[0161] It should be noted that compounds having metal chelating properties can be used in the composition according to the invention to help enhance the adhesion of the cured adhesive to the substrate surface. In addition, also suitable as an adhesion promoter is an acetoacetate-functionalized modified resin sold by King Industries under the trade name K-FLEX XM-B301.

[0162] To further improve the storage period, it is generally recommended to further stabilize the composition of the present invention in terms of moisture permeability by using a desiccant. Occasionally, it is also necessary to reduce the viscosity of the composition according to the present invention for a specific application by using one or more reactive diluents. Based on the total weight of the composition, the total amount of reactive diluent present will generally be at most 10% by weight, preferably 1 - 5% by weight.

[0163] The presence of solvents and non-reactive diluents in the composition of the present invention is not excluded, which can effectively adjust its viscosity. For example, but for illustrative purposes only, the composition may contain one or more of the following: xylene; 2-methoxyethanol; dimethoxyethanol; 2-ethoxyethanol; 2-propoxyethanol; 2-isopropoxyethanol; 2-butoxyethanol; 2-phenoxyethanol; 2-benzyloxyethanol; benzyl alcohol; ethylene glycol; ethylene glycol dimethyl ether; ethylene glycol diethyl ether; ethylene glycol dibutyl ether; ethylene glycol diphenyl ether; diethylene glycol; diethylene glycol monomethyl ether; diethylene glycol monoethyl ether; diethylene glycol monon-butyl ether; diethylene glycol dimethyl ether; diethylene glycol diethyl ether; diethylene glycol di-n-butyl ether; propylene glycol butyl ether; propylene glycol phenyl ether; dipropylene glycol; dipropylene glycol monomethyl ether; dipropylene glycol dimethyl ether; dipropylene glycol di-n-butyl ether; N-methylpyrrolidone; diphenylmethane; diisopropylnaphthalene; petroleum fractions such as products (available from Exxon); alkylphenols such as tert-butylphenol, nonylphenol, dodecylphenol, and 8,11,14-pentadecatrienylphenol; styrenated phenols; bisphenols; aromatic hydrocarbon resins, especially those containing phenolic groups, such as ethoxylated or propoxylated phenols; adipates; sebacates; phthalates; benzoates; organic phosphates or sulfonates; and sulfonamides.

[0164] In addition to the above, preferably, based on the total weight of the composition, the solvents and non-reactive diluents together account for less than 10% by weight, especially less than 5% by weight or less than 2% by weight.

[0165] Exemplary embodiments of the two-component composition

[0166] In an exemplary embodiment of the present invention, based on the weight of the composition, the two-component (2K) composition comprises:

[0167] A first component, the first component comprising:

[0168] 20 - 60% by weight of a) at least one diepoxide selected from: diglycidyl ethers based on bisphenol A; diglycidyl ethers based on hydrogenated bisphenol A; bisphenol F diglycidyl ether; and diglycidyl ethers based on hydrogenated bisphenol F; and

[0169] A second component, the second component comprising:

[0170] b) A polyamine mixture, wherein each polyamine has at least two amine hydrogens reactive towards epoxy groups, and the mixture comprises:

[0171] b) i) m-Xylylenediamine (MXDA); and

[0172] b) ii) at least one alicyclic primary diamine having an amine hydrogen equivalent weight of not more than 150 g / eq; and / or

[0173] b) iii) at least one aliphatic primary diamine compound selected from: 3-(2-aminoethyl)aminopropylamine; triethylenetetramine (TETA); tetraethylenepentamine (TEPA); and pentaethylenehexamine (PEHA); and

[0174] 5 - 30% by weight of c) at least one phenolic resin obtained by reacting at least one phenolic compound with at least one

[0175] aldehyde having the general formula R a -(CHO) b wherein in said general formula:

[0176] R a is H, C 1 -C 8 alkyl, or C 2 -C 8 alkenyl; and

[0177] b is 1 or 2,

[0178] wherein the curable composition is characterized in that the stoichiometric ratio of the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is from 0.5:1 to 1.2:1, preferably from 0.8:1 to 1.0:1.

[0179] In yet another exemplary embodiment of the present invention, based on the weight of the composition, the two-component (2K) composition comprises:

[0180] A first component, said first component comprising:

[0181] 20 - 60% by weight of a) at least one diepoxide selected from: diglycidyl ethers based on bisphenol A; diglycidyl ethers based on hydrogenated bisphenol A; bisphenol F diglycidyl ether; and diglycidyl ethers based on hydrogenated bisphenol F; and

[0182] A second component, said second component comprising:

[0183] b) A polyamine mixture, wherein each polyamine has at least two amine hydrogens reactive towards epoxy groups, and the mixture comprises:

[0184] b) i) m - Xylylenediamine (MXDA); and

[0185] b) ii) at least one alicyclic primary diamine having an amine hydrogen equivalent weight of not more than 150 g / eq; and / or

[0186] b) iii) Triethylenetetramine (TETA); and

[0187] 5 - 30% by weight of c) at least one phenolic resin obtained by reacting phenol with at least one aldehyde having the general formula R a -(CHO) b wherein in said general formula:

[0188] R a is H, C 1 -C 4 alkyl, or C 2 -C 4 alkenyl; and

[0189] b is 1,

[0190] wherein the curable composition is characterized in that the stoichiometric ratio of the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is from 0.5:1 to 1.2:1, preferably from 0.8:1 to 1.0:1.

[0191] Methods and applications

[0192] For two - component (2K) curable compositions, the reactive components are combined and mixed in a manner that causes them to harden: the reactive compounds should be mixed under shear forces sufficient to produce a homogeneous mixture. It is considered that this can be achieved without special conditions or special equipment. That is, suitable mixing devices can include: static mixing devices; magnetic stir bar equipment; wire stirrer devices; augers; batch mixers; planetary mixers; C.W. Brabender or type mixers; and high - shear mixers such as blade - type blend mixers and rotary mixers.

[0193] For small-scale liner applications that typically use volumes of less than 2 liters, a preferred packaging for two-component (2K) compositions will be side-by-side or coaxial cartridges, where two tubular chambers are arranged side-by-side or one inside the other and sealed with pistons: actuation of these pistons allows the components to be advantageously extruded from the cartridges through a closely mounted static or dynamic mixer. For larger volume applications, the two components of the composition can be advantageously stored in drums or pails: in this case, the two components are extruded via a hydraulic press, in particular through a follower plate, and supplied via pipes to a mixing device that can ensure a fine and highly homogeneous mixing of the hardener component with the binder component. In any case, for any packaging, it is important to place the binder component within an airtight and watertight seal such that both components can be stored for a long time, desirably for 12 months or longer.

[0194] Non-limiting examples of two-component dispensing devices and methods that can be applied to the present invention include those described in U.S. Patent No. 6,129,244 and U.S. Patent No. 8,313,006.

[0195] The two-component (2K) curable composition should be formulated broadly to exhibit an initial viscosity of less than 200,000 mPa·s at 25°C, e.g., less than 100,000 mPa·s, which is measured immediately after mixing (e.g., up to two minutes after mixing). Independently of or in addition to the viscosity characteristic, the two-component (2K) composition should be formulated to be bubble-free (foam-free) upon mixing and subsequent curing.

[0196] Curing of the compositions of the present invention can occur in the temperature range of -10°C to 150°C, preferably 0°C to 120°C, particularly 20°C to 120°C. The appropriate temperature depends on the specific compounds present and the desired curing rate and can be determined by those skilled in the art in each case using simple preliminary tests as needed. Of course, curing at a temperature of 10°C to 35°C or 20°C to 30°C is particularly advantageous as it avoids the need to heat or cool the mixture significantly from the ambient temperature that is typically prevalent. However, where applicable, the temperature of the mixture formed from the individual components of the two-component (2K) composition can be raised above the mixing temperature and / or the application temperature using conventional means, including microwave induction.

[0197] The curable composition according to the invention can in particular be used for: varnishes; inks; adhesives for fibres and / or particles; coating of glass; coating of mineral building materials (such as lime and / or cement bonded plasters, gypsum-containing surfaces, fibre-cement building materials and concrete); coating and sealing of wood and wood-based materials (such as particle boards, fibre boards and paper); coating of metal surfaces; coating of bitumen- and tar-containing road surfaces; coating and sealing of various plastic surfaces; and coating of leather and textiles.

[0198] It is also considered that the composition of the invention is suitable as a pourable sealant for building electrical components such as cables, optical fibres, cover strips, or plugs. The sealant can be used to protect those components against the ingress of water and other contaminants, against thermal exposure, temperature fluctuations and thermal shocks, and against mechanical damage.

[0199] Due to the fact that the composition of the invention is capable of generating a high bond strength in a short time, usually at room temperature, the composition is most suitable for forming composite structures by surface-to-surface bonding of the same or different materials to each other. The bonding together of wood and wood-based materials and of metal materials can be mentioned as exemplary adhesive applications of the composition of the invention.

[0200] In each of the above applications, the composition can be applied by conventional application methods such as: brushing; roll coating; doctor blade application; printing methods; and spraying methods including, but not limited to, air atomization spraying, air-assisted spraying, airless spraying and high volume low pressure spraying. For coating and adhesive applications, it is recommended to apply the composition with a wet film thickness of 10 - 500 μm. Applying a thinner layer within this range is more economical and provides the possibility of reducing thick cured areas which may require sanding for coating applications. However, sufficient control must be exercised when applying thinner coatings or layers to avoid the formation of discontinuous cured films.

[0201] For the sake of completeness, it should be noted that the invention does not exclude the preparation of epoxy adhesives in the form of "film adhesives". A prepolymer mixture of epoxy resin, hardener and other desired components is applied as a coating to a polymer film substrate, rolled up and stored at a low temperature sufficient to inhibit the chemical reaction between the components. When needed, the film adhesive is removed from the low temperature environment and applied to metal or composite parts, the backing is peeled off, the assembly is completed and cured in an oven or autoclave.

[0202] The following examples describe various features and embodiments of the present disclosure, which are intended to be representative and not restrictive.

[0203] Examples

[0204] The following commercial products were used in the examples:

[0205] DER 356: Reaction product of bisphenol A and bisphenol F with epichlorohydrin, available from Olin.

[0206] BB-AMIDE 5033: Medium to low viscosity reactive polyamide resin (AHEW 95 - 110 g / eq.), available from BBResins S.r.l.

[0207] BB-Amine 3004: Amino-functional bisphenol A, available from BB Resins S.r.l.

[0208] Hard D140G: Medium to low viscosity reactive polyamide resin (AHEW 95 - 110 g / eq.), available from BB ResinsS.r.l.

[0209] DCH99: Cyclohexane-1,2-diamine, available from Huntsman.

[0210] Amicure PACM: Bis(para-aminocyclohexyl)methane, available from Evonik Operations GmbH.

[0211] Ancamine 1916: Phenol-free amine adduct (AHEW 43 g / eq.), available from Evonik OperationsGmbH.

[0212] Ancamine 2280: Low viscosity modified alicyclic amine (AHEW), available from Evonik Operations GmbH.

[0213] Ancamine 2914UF: Blend of aliphatic amines (AHEW 95 g / eq.) available from Evonik OperationsGmbH.

[0214] Ancamine 2432: Blend of m-xylene diamine and phenol-formaldehyde resin (AHEW 88 g / eq.), available from Evonik Operations GmbH.

[0215] Omicure 24EMI: 2-Ethyl-4-methylimidazole, available from Huntsman.

[0216] Aradur 33641: Blend of m-xylene diamine and phenol-formaldehyde resin (AHEW 58 g / eq.), available from Huntsman.

[0217] Triethylenetetramine: A polyamine having primary and secondary amine groups (AHEW 24 g / eq.), available from Dow Chemical.

[0218] Genamid 490: A liquid amidoamine (AHEW 95 g / eq.), available from Cognis.

[0219] Novares LS 500: An aromatic hydrocarbon resin tackifier, available from Rütgers Chemicals.

[0220] Silquest TM A-187: An epoxy-functional silane, available from Momentive Performance Materials.

[0221] Silanol A1120: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, available from Uniquechem Solutions Inc.

[0222] The above components are used to prepare the formulations given in Tables 1 and 3 below. The weight percentages (%) given in those tables are based on the weight of each component of the composition.

[0223] Then, the following test methods are used to characterize the two-component formulations:

[0224] Viscosity : The initial viscosity of the freshly mixed composition (first component plus second component) is calculated based on the viscosities of the components (first, second) contained therein and their content ratios.

[0225] Pot life : Broadly speaking, the "pot life" means the following time period: within this time period, the composition is a liquid that is sufficient to be applied to a substrate. The "pot life" of the present disclosure specifically means the measured time required for the viscosity of the composition (400 g) to increase to 10 times the initial calculated viscosity of the composition. For example, if the initial viscosity of the composition when mixing the two components (first, second) is 100 cPs, then the pot life of the composition will be the amount of time required for the composition to reach a viscosity of 1000 cPs.

[0226] Tensile lap shear (TLS) test: The substrate is stainless steel (1.4301) with a thickness of 0.1 inches. The substrate is cut into dimensions of 2.5 cm × 10 cm (1" × 4") for tensile testing. The tensile lap shear (TLS) test is a standard test method based on ASTM D3163 - 01 for determining the strength of adhesively - bonded rigid plastic lap - shear joints in shear by tension loading at room temperature (Standard Test Method for Determining Strength of Adhesively Bonded Rigid Plastic Lap - Shear Joints in Shear by Tension Loading). The adhesive overlap area of each said substrate is 2.5 cm × 1.3 cm (1" × 1"), where the adhesive thickness is 0.1 cm (40 mil). The applied two - component (2K) adhesive composition is cured in the overlap area under two scenarios: a) before the initial tensile test, the bonded structure is stored at room temperature for 24 hours and then a temperature of 100 °C is applied for 30 minutes; and b) before the initial tensile test, the bonded structure is stored at room temperature for 7 days (168 hours).

[0227] Shore hardness : The sample disk is prepared as follows: The components of the composition (Table 1) are mixed in a polypropylene (PP) vial at room temperature and the mixture is further homogenized in a planetary mixer (Speed Mixer: 800 rpm; 30 seconds; ambient pressure). Then, the vial is subjected to one of the two curing scenarios described above, specifically either of the following: a) the bonded structure is stored at room temperature for 24 hours and then a temperature of 100 °C is applied for 30 minutes; and b) the bonded structure is stored at room temperature for 7 days (168 hours). The Shore hardness is determined according to DIN ISO 7619 - 1 by pressing a hand - held hardness tester (Zwick 3131) onto the sample (≥6 mm thickness; 3 - second contact time before measurement). The hardness is recorded after 30 minutes (condition a)) (thus after the initial curing conditions (30 minutes, 100 °C) if applicable), or after 7 days (condition b)), and the hardness is further monitored every 30 minutes when stored at room temperature and pressure. Another data point (final hardness) is recorded after storing at room temperature for 24 hours.

[0228] Glass transition temperature (Tg, °C): The glass transition temperature is the starting temperature at which a cured resin changes from a glassy (solid) state to a soft rubbery state: it can be considered the point at which a measurable decrease in physical properties occurs due to exposure to elevated temperatures. In this article, the glass transition temperature is reported during the second heating: the cured sample is exposed to a first heating program that goes from room temperature to 200 °C at a rate of 10 °C / min, cooled, and then heated a second time using the same heating program. Differential scanning calorimetry (DSC) is used to measure the heat flow into and out of the sample to determine its Tg during the second heating. This test is conducted by placing the fully cured sample in a small container in the DSC and heating it according to a given program. The heat flow into the sample is measured and compared to an empty reference container. The difference in heat flow is measured and plotted, and the onset of the inflection point in the plotted curve is recorded as the Tg.

[0229] Abrasion resistance (Miller) test : This test is conducted according to ASTM G75. In this test, clay is mixed with water to produce a flowing slurry that contacts the coating of the composition applied to a stainless-steel test piece.

[0230] Boeing Flow Test : According to the Standard Test Method for Slump of Sealants (ASTM D2202), the slump of the cured composition when applied to vertical joints is tested.

[0231] Hazard statement (H-statement) : These instructions are part of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). For the exemplary composition, the health hazards (H3xx) evaluated include: H302, Harmful if swallowed; H314, Causes severe skin burns and eye damage; H317, May cause an allergic skin reaction; H318, Causes serious eye damage; H331, Toxic if inhaled; H332, Harmful if inhaled; H335, May cause respiratory irritation; H360, May damage fertility or the unborn child; H360d, May damage the unborn child; H360Fd, May damage fertility and may damage the unborn child; and H373, Causes damage to organs through repeated or prolonged exposure. For the exemplary composition, the environmental hazards (H4xx) evaluated include: H412, Harmful to aquatic life. Reference can be made to https: / / www.msds-europe.com / wp-content / uploads / 2020 / 10 / Hazard-statement.pdf.

[0232] Experiment 1

[0233] Prepare a two-component formulation according to Table 1 below: Reference Example 1 represents a known commercial product. The weight percentages (wt%) given are based on the total weight of each component.

[0234] Table 1

[0235]

[0236] For each formulation, degas the described first resin component and second component under vacuum at room temperature. Then, with stirring using a spatula, mix the components in the stated weight ratio corresponding to the desired functional group equivalent ratio.

[0237] Conduct the above tests, and the results are provided in Table 2 below.

[0238] Table 2

[0239]

[0240] Experiment 2

[0241] Prepare a two-component formulation according to Table 3 below: Reference Example 2 represents a known commercial product. The weight percentages (wt%) given are based on the total weight of each component.

[0242] Table 3

[0243] Material description Reference Example 2 Example 2 Example 3 Example 4 Example 5 First component (A) DER 356 35.0 35.0 35.0 35.0 35.0 Filler 62.5 62.5 62.5 62.5 62.5 Silquest A187 0.4 0.4 0.4 0.4 0.4 Additive 2.1 2.1 2.1 2.1 2.1 Second component (B) Ancamine 2280 73.8 73.8 64.8 65.3 BB Amine 3004 11.8 Amicure PACM 14.4 14.4 21.2 26.7 13.4 DCH99 - 5.9 - - - Ancamine 2914UF - 5.9 - - - Aradur 33641 - - 15.0 8.0 - Ancamine 2432 - - - - 86.6

[0244] For each formulation, degas the described first resin component and second component under vacuum at room temperature. Then, load the components into the respective barrels of a dual-barrel syringe in the stated weight ratio corresponding to the desired functional group equivalent ratio. Then, attach a static mixing tip to the outlet of the syringe, and dispense the components through the static mixing tip at a constant pressure to ensure a uniform flow from both barrels and thorough mixing before application to the substrate.

[0245] Conduct the above tests, and the results are provided in Table 4 below.

[0246] Table 4

[0247]

[0248] Experiment 3

[0249] Prepare a two-component formulation according to Table 5 below. The weights given in the table are the weight percentages (wt%) of each component of the two-component composition.

[0250] Table 5

[0251] Material description Reference Example 3 Example 6 Example 7 First component (A) DER 331 24.1 24.1 22.6 Epodil 750 2.0 2.0 2 Silquest A187 0.2 0.2 0.2 Filler 72.9 72.9 71.9 Additive 0.8 0.8 3.3 Second component (B) Hard E908 8.0 Genamid 490 4.4 2.5 2.5 Hard D140G 4.4 4.5 4.5 Silanol A1120 0.2 0.2 0.2 Aradur 33461 5.2 5.2 TETA 4.6 4.6 Filler 80.2 80.2 80.2 Additive 2.8 2.8 2.8

[0252] For each formulation, the described first resin component and second component are degassed under vacuum at room temperature. The components are then loaded separately into the respective barrels of a dual-barrel syringe at a weight ratio of the first (A) component to the second (B) component of 2:1 (corresponding to the desired functional group equivalent ratio). A static mixing tip is then attached to the outlet of the syringe, and the components are dispensed through the static mixing tip at a constant pressure to ensure a uniform flow from both barrels and sufficient mixing prior to application to the substrate.

[0253] The above tests were conducted and the results are provided in Table 6 below.

[0254] Table 6

[0255]

[0256] In view of the foregoing description and examples, it will be apparent to those skilled in the art that equivalent modifications can be made without departing from the scope of the appended claims.

Claims

1. Two-component (2K) curable composition, said two-component (2K) curable composition comprising: A first component, said first component comprising: a) At least one epoxy resin; and A second component, said second component comprising: b) A polyamine mixture, wherein each polyamine has at least two amine hydrogens reactive with epoxy groups, said mixture comprising: b)i) m-Xylylenediamine (MXDA); and b)ii) At least one alicyclic primary diamine; and / or b)iii) At least one aliphatic primary diamine compound further comprising one or more secondary amine groups; and c) at least one phenolic resin, said phenolic resin being obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula R a -(CHO) b wherein in said general formula: R a is H, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 6 -C 18 aryl, C 7 -C 18 alkylaryl, or C 7 -C 18 aralkyl; and b is 1 or 2, wherein said curable composition is characterized in that the stoichiometric ratio of the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is 0.5:1 to 1.2:1, preferably 0.8:1 to 1.0:

1.

2. The two-component (2K) composition according to claim 1, wherein said ingredient a) comprises at least one polyepoxide having an epoxy equivalent weight of 100 - 700 g / eq.

3. The two-component (2K) composition according to claim 1 or claim 2, wherein said ingredient a) comprises at least one polyepoxide selected from the following: glycidyl ethers of polyols; glycidyl ethers of polyphenols; glycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.

4. The two-component (2K) composition according to claim 1, wherein said ingredient a) comprises at least one diepoxide having an epoxy equivalent weight less than 500 g / eq.

5. The two-component (2K) composition according to claim 4, wherein said ingredient a) comprises at least one diepoxide selected from the following: diglycidyl ether based on bisphenol A; diglycidyl ether based on hydrogenated bisphenol A; bisphenol F diglycidyl ether; and diglycidyl ether based on hydrogenated bisphenol F.

6. The two-component (2K) composition according to any one of claims 1 - 5, wherein said second component is characterized by comprising, based on the total weight of the polyamines in the second component: 5 - 50 wt%, preferably 20 - 50 wt% of b)i) m-Xylylenediamine (MXDA); 50 - 95 wt%, preferably 50 - 80 wt% of b)ii) said at least one alicyclic primary diamine.

7. The two-component (2K) composition according to any one of claims 1 - 5, wherein said second component is characterized by comprising, based on the total weight of the polyamines in the second component: 5 - 50 wt%, preferably 20 - 50 wt% of b)i) m-Xylylenediamine (MXDA); 50 - 95 wt%, preferably 50 - 80 wt% of b)iii) said at least one aliphatic primary diamine compound further comprising one or more secondary amine groups.

8. The two-component (2K) composition according to any one of claims 1 - 5, wherein said second component is characterized by comprising, based on the total weight of the polyamines in the second component: 5 - 50 wt%, preferably 20 - 50 wt% of b)i) m-Xylylenediamine (MXDA); 25 - 90% by weight, preferably 25 - 40% by weight of the at least one alicyclic primary diamine as defined in b)ii); and 25 - 90% by weight, preferably 25 - 40% by weight of the at least one aliphatic primary diamine compound as defined in b)iii), said compound further comprising one or more secondary amine groups.

9. The two - component (2K) composition according to any one of claims 1 - 8, wherein the at least one alicyclic primary diamine as defined in b)ii) and the at least one aliphatic primary diamine compound as defined in b)iii) are characterized in that the amine hydrogen equivalent weight does not exceed 150 g / eq.

10. The two - component (2K) composition according to any one of claims 1 - 9, wherein the at least one aliphatic primary diamine compound as defined in b)iii) is selected from: 3-(2 - aminoethyl)aminopropylamine; triethylenetetramine (TETA); tetraethylenepentamine (TEPA); and pentaethylenehexamine (PEHA).

11. The two - component (2K) composition according to any one of claims 1 - 10, comprising 5 - 30% by weight, based on the weight of the composition, of the at least one phenolic resin as defined in c).

12. A two-component (2K) composition according to any one of claims 1-11, wherein the at least one phenolic resin is obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula R a -(CHO) b wherein in the general formula: R a is H, C 1 -C 8 alkyl, or C 2 -C 8 alkenyl; and b is 1 or 2.

13. The two - component (2K) composition according to any one of claims 1 - 12, wherein the at least one phenolic compound comprises phenol or consists of phenol.

14. The two - component (2K) curable composition according to claim 1, said composition comprising: A first component, said first component comprising: a) at least one diepoxide compound selected from: diglycidyl ethers based on bisphenol A; diglycidyl ethers based on hydrogenated bisphenol A; bisphenol F diglycidyl ether; and diglycidyl ethers based on hydrogenated bisphenol F; and A second component, said second component comprising: b) A polyamine mixture, wherein each polyamine has at least two amine hydrogens reactive towards epoxy groups, said mixture comprising: b)i) m - xylylenediamine (MXDA); and b)ii) at least one alicyclic primary diamine having an amine hydrogen equivalent weight not exceeding 150 g / eq; and / or b)iii) at least one aliphatic primary diamine compound selected from: 3-(2 - aminoethyl)aminopropylamine; triethylenetetramine (TETA); tetraethylenepentamine (TEPA); and pentaethylenehexamine (PEHA); and c) at least one phenolic resin, which is obtained by reacting at least one phenolic compound with at least one aldehyde having the general formula R a -(CHO) b wherein in said general formula: R a is H, C 1 -C 8 alkyl, or C 2 -C 8 alkenyl; and wherein the curable composition is characterized in that the stoichiometric ratio of the amine hydrogen atoms of the second component to the epoxy groups of the first component (a) is from 0.5:1 to 1.2:1, preferably from 0.8:1 to 1.0:

1.

15. A cured product obtained from the two - component (2K) composition as defined in any one of claims 1 - 14.

16. Use of the cured reaction product as defined in claim 15 as a coating, an adhesive, or a sealant.

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