Solutions of polyphenols in amines

Abstract

The subject of the invention is a solution comprising from 5% to 65% by weight of a polyphenol that is solid at room temperature and from 35% to 95% by weight of an amine of formula (I). The solution of the invention is preferably used as a curing agent for preparing epoxy resins. The solution has a low viscosity and is well miscible and compatible with epoxy resins. The present invention relates to an epoxy resin composition which enables a particularly easy-to-process low-emission epoxy resin coating with fast curing, high final hardness, defect-free glossy surface and low yellowing, which can be cured without defects at low temperatures to form a coating with high quality and robustness even without or with only a small amount of diluent.

Description

Technical Field

[0001] The invention relates to a solution of polyphenol in amine, use of the solution in preparing a curing agent for epoxy resin, and an epoxy resin composition formed therefrom and cured at room temperature. Background Art

[0002] Room-temperature-curing polymer compositions based on epoxy resins are widely used in the construction industry. They consist of a liquid resin component and a curing agent component, which are mixed before application and cured at ambient temperature to form a material with high strength and stability. However, under colder ambient conditions, for example in a temperature range of 15°C to close to 0°C, such systems generally cure only slowly and no longer reach the required final hardness even with subsequent heating. In addition, they tend to develop surface defects such as turbidity, spots, roughness or stickiness (also known as "blushing"), especially at elevated air humidity. In particular in coating applications where high surface quality and hardness are essential, these defects are highly undesirable and often lead to laborious finishing. The use of common accelerators, such as 2,4,6-tris(dimethylaminomethyl)phenol, generally only partially solves the problem or does not solve it at all.

[0003] Well-known accelerators are phenolic compounds, especially for rapid curing at low temperatures. However, common liquid phenolic compounds, such as phenol itself, tert-butylphenol or nonylphenol, are highly toxic substances and have therefore hardly been used in epoxy resin products for some time. Also known is cardanol, a C-containing phenol obtained from the shell of the cashew nut. 15 - Hydrocarbon chain-substituted phenols. However, cardanol has only a small accelerating effect, has poor compatibility with epoxy resins when used in larger amounts, and has an undesirable lowering effect on the glass transition temperature of the cured product. Polyphenols are also known as accelerators, in particular the so-called phenolic resins, in particular those which are polymerized from phenol and formaldehyde. However, polyphenols are generally solid at room temperature, poorly soluble, and generally have a high viscosity when dissolved in the common amine curing agents. Dilution with solvents such as xylene is disadvantageous because this leads to undesirably high emissions.

[0004] US 6,649,729 describes the use of phenolic resins in epoxy resin products to promote cure and reduce haze, the epoxy resin products containing common amine curing agents such as isophorone diamine (IPDA) or diethylene triamine. US2010 / 0210758 describes the use of large amounts of phenolic resins in epoxy resin coatings to promote cure and improve chemical resistance, the epoxy resin coatings containing amine curing agents such as 1,3-bis (aminomethyl) benzene (MXDA) or trimethyl hexamethylene diamine (TMD).

[0005] For example, WO 2020 / 070082 discloses that alkylated amines such as N-benzyl-1,2-ethylenediamine can be used as curing agents for epoxy resins, which can achieve epoxy resin coatings with an aesthetically pleasing surface even at low temperatures, wherein the final hardness of the coating after curing at low temperatures tends to be lower than the final hardness after curing at room temperature. Summary of the invention

[0006] The object of the present invention is to provide an accelerator for epoxy resin curing which is liquid at room temperature and exhibits a high effect as an accelerator, has a low viscosity and is well miscible and compatible with epoxy resin, and ensures complete curing without defects under low temperature ambient conditions.

[0007] Surprisingly, this object is achieved by a solution comprising 5% to 65% by weight of polyphenols which are solid at room temperature and 35% to 95% by weight of amines of formula (I), as described in claim 1. Surprisingly, the amines of formula (I) are able to dissolve large amounts of polyphenols while having a viscosity which is easy to handle. The solution of the invention is particularly advantageous for preparing hardeners for epoxy resins. Using the solution of the invention, hardeners with an easily adjustable polyphenol content can be prepared in a simple manner, which have a particularly low viscosity and are well miscible and compatible with epoxy resins. Particularly surprising is the fact that the hardener enables epoxy resin products which cure particularly flawlessly at low temperatures and have a particularly high final hardness. In particular, the epoxy resin coatings which can be achieved have a surprisingly high hardness after curing for 7 days at low temperatures (8°C / 80% relative humidity) and then for 14 days in a standard climate, which is very close to the hardness obtained after curing for 14 days in a standard climate. Preferably, the hardness achieved (in The hardness (measured in hardness) is at least 70%, particularly preferably at least 80%, and in particular at least 90% of the hardness value after curing in standard climate. Surprisingly, curing at low temperatures can be achieved using small amounts of the solution according to the invention, so that even without diluent or with small amounts of diluent, the processability of such coatings is very good, and therefore the emissions are particularly low.

[0008] The common amines used as curing agents for epoxy resins in the prior art, such as IPDA or MXDA, are clearly less suitable for the preparation of polyphenol solutions. Thus, the use of certain polyphenols, such as diphenolic acids, results in solutions that are extremely viscous to the point of being pasty and / or incompatible with epoxy resins. Although the use of other polyphenols, such as, in particular, phenol-formaldehyde-novolacs, sometimes results in similarly low-viscosity and compatible solutions that are able to promote the curing of epoxy resins, when cured at low temperatures, the cured coatings show a greatly reduced final hardness, which limits the robustness of the coating or requires laborious finishing.

[0009] The solutions of the invention enable easy-to-process, low-emission epoxy resin coatings with rapid curing, high final hardness, a glossy surface without defects and low yellowing, which cure surprisingly without defects at low temperatures, in particular at temperatures of 5 to 8° C., even without or with only small amounts of diluents such as benzyl alcohol, to form coatings with high quality and durability.

[0010] Further aspects of the invention are the subject matter of further independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims. DETAILED DESCRIPTION

[0011] The subject of the invention is a solution comprising 5 to 65% by weight of a polyphenol which is solid at room temperature and 35 to 95% by weight of an amine of the formula (I),

[0012] R-NH-A-NH2 (I)

[0013] in

[0014] A represents a straight or branched alkylene group having 2 to 10 carbon atoms, and R represents a monovalent hydrocarbon group optionally containing an oxygen atom and having 1 to 12 carbon atoms,

[0015] Therein the amine of formula (I) has a total of 8 to 15 carbon atoms and the two nitrogen atoms are separated from one another by at least two carbon atoms.

[0016] "Solution" means a clear, homogeneous liquid in which the ingredients are completely dissolved.

[0017] "Polyphenol" means a compound having two or more phenolic groups (=phenolic OH-groups).

[0018] "Phenolic resin" means a polymer having repeating units containing phenol groups.

[0019] "Amine hydrogen" refers to the hydrogen atoms of primary and secondary amino groups.

[0020] "Amine hydrogen equivalent" refers to the mass of an amine or amine-containing composition containing one molar equivalent of amine hydrogen. It is expressed in units of "g / eq".

[0021] "Epoxy equivalent" means the mass of an epoxy group-containing compound or composition containing one molar equivalent of epoxy groups. It is expressed in the unit "g / eq".

[0022] Substance names beginning with "poly", such as polyamine or polyepoxide, denote substances that formally contain two or more of the functional groups appearing in their names per molecule.

[0023] "Primary amino group" means an amino group that is bonded to only one organic group and has two hydrogen atoms; "secondary amino group" means an amino group that is bonded to two organic groups (which may also together form part of a ring) and has one hydrogen atom; and "tertiary amino group" means an amino group that is bonded to three organic groups (two or three of which may also form part of one or more rings) and has no hydrogen atoms.

[0024] "Diluent" means a substance that is soluble in the epoxy resin and reduces its viscosity, which substance does not chemically bond to the epoxy resin polymer upon curing.

[0025] "Molecular weight" refers to the molar mass of a molecule (in grams / mole). "Average molecular weight" refers to the number average molecular weight of a polydisperse mixture of oligomer or polymer molecules. n , which is typically determined by gel permeation chromatography (GPC) relative to polystyrene standards.

[0026] The dashed lines in the formulas herein each represent a bond between a substituent and the molecular group to which it belongs. "Pot life" means the maximum time interval from mixing of the components and application of the epoxy resin composition during which the mixed composition is sufficiently fluid and can wet the substrate surface well.

[0027] "Room temperature" means a temperature of 23°C.

[0028] Unless otherwise stated, all industry standards or specifications referred to herein refer to the versions in effect prior to the time of filing this application.

[0029] Unless otherwise indicated, weight percent (wt%) indicates the mass content of an ingredient in a composition based on the entire composition. The terms "mass" and "weight" are used synonymously herein.

[0030] Preferred are polyphenols having a melting or softening point of at least 50°C.

[0031] Preferred polyphenols are compounds which are solid at room temperature and have 2 to 10 phenol groups, and in particular phenol group-containing polymers which are solid at room temperature and contain on average 3 to 100, preferably 3 to 50, phenol groups.

[0032] Suitable room temperature solid compounds having 2 to 10 phenolic groups are, in particular, catechol (1,2-dihydroxyphenol), resorcinol (1,3-dihydroxyphenol), hydroquinone (1,4-dihydroxyphenol), the isomeric dihydroxybenzoic acids, gallic acid (3,4,5-trihydroxybenzoic acid), bisphenol A (2,2-bis(4-hydroxyphenyl)propane), bisphenol F (bis(4-hydroxyphenyl)methane), bisphenol E (1,1-bis(4-hydroxyphenyl)ethane), bisphenol B (2,2-bis(4-hydroxyphenyl)butane), bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), diphenolic acid (4,4-bis(4-hydroxyphenyl)valeric acid), and degradation products of lignin such as, in particular, resveratrol (3,5,4'-trihydroxystilbene), malvidin (Ma lvidin) (3,4',5,7-tetrahydroxy-3',5'-dimethoxyflavanium (-flavyl ium)) or catechin (2-(3,4-dihydroxyphenyl)chromane-3,5,7-triol).

[0033] Preferably, the polyphenol that is solid at room temperature is selected from gallic acid, diphenolic acid, resveratrol, catechins and phenol-containing polymers, in particular phenolic resins.

[0034] Particularly preferred are diphenolic acids. These polyphenols are obtainable by simple processes from renewable raw materials, dissolve in large quantities in the amines of the formula (I), and enable easy-to-process epoxy resin coatings with rapid curing, high final hardness and an aesthetically pleasing surface.

[0035] Also particularly preferred as polyphenols are phenol-containing polymers which are solid at room temperature, in particular so-called novolac resins. Phenolic resins preferably contain repeating units which are obtained by polymerization of phenol, cresol, xylenol and / or cardanol with aldehydes, in particular formaldehyde.

[0036] Preferred are room temperature solid phenolic resins derived from phenol (hydroxybenzene), m-cresol or cardanol, especially phenol.

[0037] In particular, the polyphenol which is solid at room temperature is phenol-formaldehyde novolac or phenol-formaldehyde novolac containing cardanol, and phenol-formaldehyde novolac is particularly preferred.

[0038] Preferably, the polyphenol which is solid at room temperature is a phenolic resin of formula (II)

[0039]

[0040] in

[0041] The average value of n is 1 to 45, preferably 1 to 25, especially 1 to 10, and

[0042] R 1independently of one another represent H or an aliphatic hydrocarbon radical having 1 to 15 carbon atoms, preferably H, methyl or a straight-chain aliphatic C 15 - Hydrocarbyl.

[0043] The phenolic resin of formula (II) is particularly characterized by at least one The phenolic resin is obtained by polymerizing a phenolic compound with formaldehyde and releasing water. Preferably, formaldehyde is used in the form of paraformaldehyde. Preferably, the volatile components are removed after polymerization to make the free phenol (R 1 =H) content is less than 1 wt% and formaldehyde content is less than 0.1 wt%.

[0044] Preferably, the -CH2- unit in formula (II) is located in the ortho-position or para-position to the phenolic group.

[0045] Preferably, R not representing H 1 Located in the meta position of the phenol group.

[0046] If R 1 represents a straight-chain aliphatic C having 0, 1, 2 or 3 double bonds 15 -hydrocarbyl group, the group is preferably derived from cardanol.

[0047] "Cardanol" means the formula obtained from cashew nut shell liquid. A mixture of alkenylphenols, wherein R 1 Indicates straight chain aliphatic C 15 H 31 - or C 15 H 29 - or C 15 H 27 - or C 15 H 25 - a hydrocarbon group, in particular a group of the formula

[0048]

[0049] Preferably, all R in formula (II) 1 The groups all represent H, or at least half of them are R 1 The group represents H and the other R 1 The group is derived from cardanol.

[0050] Most preferably, all R 1 The phenolic resin is a phenol-formaldehyde resin in which the groups all represent H. Such phenolic resins are also called phenol-formaldehyde novolacs.

[0051] The average molecular weight M is preferably nThe phenolic resin of formula (II) is 300 to 5000 g / mol, preferably 350 to 3000 g / mol, and particularly 400 to 1500 g / mol.

[0052] Preference is given to phenolic resins of the formula (II) having a softening temperature of 55 to 140° C., in particular 60 to 120° C.

[0053] The preferred polyphenols can be dissolved in particularly large quantities in the amines of the formula (I), so that the solutions obtained thereby enable epoxy resin coatings which cure particularly flawlessly at low temperatures.

[0054] The solution of the invention further comprises at least one amine of formula (I),

[0055] R-NH-A-NH2 (I)

[0056] in

[0057] A represents a straight or branched alkylene group having 2 to 10 carbon atoms, and R represents a monovalent hydrocarbon group optionally containing an oxygen atom and having 1 to 12 carbon atoms,

[0058] Therein the amine of formula (I) has a total of 8 to 15 carbon atoms and the two nitrogen atoms are separated from one another by at least two carbon atoms.

[0059] Preferably, A is selected from 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,3-butylene, 2-methyl-1,2-propylene, 1,3-pentylene, 1,5-pentylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene, 2-methyl-1,5-pentylene, 1,7-heptylene, 1,8-octylene, 2,5-dimethyl-1,6-hexylene, 1,9-nonylene and 1,10-decylene.

[0060] Particularly preferred are 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, in particular 1,2-ethylene or 1,2-propylene.

[0061] Most preferred is 1,2-ethylene.

[0062] Preferably, R comprises at least one aromatic ring or aliphatic ring, in particular at least one aromatic ring.

[0063] In particular, R is selected from benzyl, furfuryl, 2-phenylethyl, cyclohexylmethyl and tetrahydrofurfuryl.

[0064] Preferred among them are benzyl or furfuryl, particularly benzyl.

[0065] Particularly preferred amines of the formula (I) are N-benzyl-1,2-ethylenediamine, N-benzyl-1,2-propylenediamine, N-furfuryl-1,2-ethylenediamine, N-tetrahydrofurfuryl-1,2-ethylenediamine, in particular N-benzyl-1,2-ethylenediamine, N-furfuryl-1,2-ethylenediamine or N-tetrahydrofurfuryl-1,2-ethylenediamine.

[0066] Most preferred as amine of formula (I) is N-benzyl-1,2-ethylenediamine.

[0067] Particularly large amounts of polyphenols can be dissolved in the preferred amines of the formula (I), the resulting solutions enabling epoxy resin coatings which cure particularly flawlessly at low temperatures.

[0068] The solution of the invention preferably contains 10% to 50% by weight, in particular 20% to 45% by weight, of polyphenols. Such a solution has a viscosity that is easy to handle and good miscibility or compatibility with epoxy resins.

[0069] The solutions according to the invention preferably contain 50% to 90% by weight, in particular 55% to 80% by weight, of the amine of the formula (I). Such solutions have a viscosity which is easy to handle and a high content of phenolic groups.

[0070] Preferably, the weight ratio between polyphenol and amine of formula (I) in the solution according to the invention is in the range from 5 / 95 to 65 / 35, particularly preferably from 10 / 90 to 50 / 50, in particular from 20 / 80 to 45 / 55.

[0071] The solution of the present invention may optionally contain other ingredients.

[0072] A preferred solution comprises

[0073] 5 to 65% by weight, preferably 10 to 50% by weight, in particular 20 to 45% by weight, of polyphenols which are solid at room temperature,

[0074] 35 to 95% by weight, in particular 50 to 90% by weight, of an amine of the formula (I), and

[0075] - 0% to 30% by weight of other amines and / or diluents and / or accelerators not conforming to formula (I).

[0076] In a preferred embodiment, the solution comprises as further constituent at least one amine of the formula (Ia) and / or an amine of the formula (Ib) and / or an amine-functional adduct of an amine of the formula (I) with at least one mono- or polyepoxide,

[0077] R-NH-A-NH-R (Ia)

[0078] NH2-A-NH2 (Ib)

[0079] wherein A and R have the meanings indicated above and each represent the same radical as in the corresponding amine of formula (I).

[0080] The amine of formula (Ia) corresponds to the N,N'-dialkylated amine of the corresponding monoalkylated amine of formula (I), and the amine of formula (Ib) corresponds to the corresponding non-alkylated amine. Such amine mixtures are in particular the reaction products of the reductive alkylation of amines of formula (Ib) with substoichiometric amounts of aldehydes or ketones, in particular benzaldehyde or furfural, and hydrogen.

[0081] Preferably, after the alkylation, unreacted amine of formula (Ib) is substantially removed from the reaction mixture, in particular by distillation, to obtain an amine mixture containing the amine of formula (I) and the corresponding amine of formula (Ia).

[0082] In a preferred embodiment of the invention, the amines of formula (I) are used in a purity of >95% for dissolving the polyphenols. The solutions of the invention are essentially free of amines of formulae (Ia) and (Ib).

[0083] In another preferred embodiment of the invention, the amines of formula (I) are used in a mixture with the corresponding amines of formula (Ia) and (Ib), wherein the weight ratio between the amines of formula (I) and the amines of formula (Ia) is preferably in the range of 70 / 30 to 90 / 10 and the content of the amines of formula (Ib) is preferably less than 1% by weight, based on the sum of the amines of formula (I) and (Ia). Such amine mixtures can be prepared particularly cheaply and are just as suitable for dissolving polyphenols as the amines of formula (I) of higher purity.

[0084] The solutions according to the invention may also contain amine-functional adducts of amines of the formula (I) with at least one mono- or polyepoxide. Suitable monoepoxides are in particular cresyl glycidyl ether. Preference is given to adducts with at least one polyepoxide, in particular bisphenol A diglycidyl ether or bisphenol F diglycidyl ether or phenol-novolac glycidyl ethers with an average functionality of 2.3 to 4. Most preferred are amine-functional adducts of amines of the formula (I) with bisphenol A diglycidyl ether.

[0085] Other ingredients that the solution of the invention may contain are in particular

[0086] - accelerators, such as, in particular, 3-(3-dimethylaminopropylamino)propylamine (DMAPAPA), 2,4,6-tris(dimethylaminomethyl)phenol, salicylic acid, calcium nitrate and / or water, or

[0087] - diluents, such as, in particular, benzyl alcohol, styrenated phenols, ethoxylated phenols, aromatic hydrocarbon resins containing phenolic groups which are liquid at room temperature, such as, in particular Types LS 500, LX 200, LA 300 or LA 700 (from Rütgers), diisopropylnaphthalene, diisopropylbiphenyl, isopropylbiphenyl or cardanol, in particular benzyl alcohol.

[0088] The solutions according to the invention preferably contain less than 0.5% by weight, preferably less than 0.2% by weight, in particular less than 0.1% by weight, of free phenol (hydroxybenzene), based on the total solution. Such solutions are particularly advantageous from a toxicological point of view.

[0089] Preferably, the viscosity of the solution of the present invention at 20° C. is in the range of 0.01 to 100 Pa·s, more preferably 0.02 to 50 Pa·s, particularly preferably 0.03 to 20 Pa·s, in particular 0.05 to 10 Pa·s.

[0090] The solution of the invention is particularly suitable for preparing curing agents for epoxy resins. Using the solution of the invention, curing agents can be prepared quickly and easily, and the polyphenol content can be easily adjusted. The curing agents obtained with the solution are excellently miscible and compatible with epoxy resins, enabling easy processing and low-emission epoxy resin coatings to be achieved, which have fast curing, high final hardness, defect-free glossy surface, low yellowing and defect-free curing, especially at low temperatures.

[0091] A further subject matter of the present invention is therefore the use of the solution for preparing a hardener for epoxy resins, wherein the hardener contains at least one further amine having at least three amine hydrogens.

[0092] Preferably, the further amine having at least three amine hydrogens is selected from the group consisting of amines of formula (I), 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine), 2,2(4),4-trimethyl-1,6-hexanediamine (TMD), 1,2-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, isophoronediamine (IPDA), 2(4)-methyl-1,3-diaminocyclohexane (IPDA), ...1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, Aminocyclohexane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 1,3-bis(aminomethyl)benzene (MXDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), dipropylenetriamine (DPTA), N-(2-aminoethyl)-1,3-propylenediamine (N3-amine), N,N'-bis(3-aminopropyl)ethylenediamine (N4-amine), bis(hexamethylene)triamine (BHMT), average molecular weight M n Polyoxypropylene diamine, average molecular weight M in the range of 200 to 500 g / mol nPolyoxypropylenetriamine in the range of 300 to 500 g / mol, 3-(3-(dimethylamino)propylamino)propylamine (DMAPAPA), 2,5-bis(aminomethyl)furan, 2,5-bis(aminomethyl)tetrahydrofuran, bis(5-aminomethylfuran-2-yl)methane, bis(5-aminomethyltetrahydrofuran-2-yl)methane, 2,2-bis(5-aminomethylfuran-2-yl)propane, 2,2-bis(5-aminomethyltetrahydrofuran-2-yl)propane, amine-functional adducts of the above amines with mono- or polyepoxides, phenalkamines and mixtures of two or more of the above amines.

[0093] Preferred mono- or poly-epoxides as amine-functional adducts are cresol glycidyl ethers, in particular bisphenol A diglycidyl ether or phenol novolac glycidyl ethers having an average functionality of 2.3 to 4. Preference is given to amine-functional adducts with bisphenol A diglycidyl ether.

[0094] Preferred phenalkamines are reaction products of cardanol with formaldehyde and amines, such as, in particular, DETA, TETA or MXDA.

[0095] Particularly preferred further amines having at least three amine hydrogens are amines of the formula (I), in particular N-benzyl-1,2-ethylenediamine, N-furfuryl-1,2-ethylenediamine or N-tetrahydrofurfuryl-1,2-ethylenediamine, and also IPDA, MXDA, 1,3-bis(aminomethyl)cyclohexane, TETA, TEPA, N4-amine, DMAPAPA or adducts of these amines with bisphenol A diglycidyl ether.

[0096] The curing agent preferably contains further components, in particular accelerators and / or diluents.

[0097] Suitable accelerators are, in particular, acids or compounds which can be hydrolyzed to acids, in particular organic carboxylic acids such as acetic acid, benzoic acid, salicylic acid, 2-nitrobenzoic acid, lactic acid, organic sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid or 4-dodecylbenzenesulfonic acid, sulfonic acid esters, other organic or inorganic acids such as, in particular, phosphoric acid, or mixtures of the abovementioned acids and esters; nitrates such as, in particular, calcium nitrate; tertiary amines such as, in particular, 1,4-diazabicyclo[2.2.2]octane, benzyldimethylamine, α-methylbenzyldimethylamine, triethanolamine, dimethylaminopropylamine, imidazoles such as Such as, in particular, N-methylimidazole, N-vinylimidazole or 1,2-dimethylimidazole, salts of the tertiary amines, quaternary ammonium salts, such as, in particular, benzyltrimethylammonium chloride, amidines, such as, in particular, 1,8-diazabicyclo[5.4.0]-7-undecene, guanidines, such as, in particular, 1,1,3,3-tetramethylguanidine, compounds containing phenolic groups, in particular, Mannich bases, such as, in particular, 2-(dimethylaminomethyl)phenol or 2,4,6-tris(dimethylaminomethyl)phenol, phosphites, such as, in particular, di- or triphenylphosphite, or compounds having mercapto groups.

[0098] Preference is given to acids, nitrates, tertiary amines or Mannich bases, in particular salicylic acid, calcium nitrate or 2,4,6-tris(dimethylaminomethyl)phenol, or combinations of these accelerators.

[0099] Suitable diluents are, in particular, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, n-hexanol, 2-ethylhexanol, xylene, 2-methoxyethanol, dimethoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, benzyl alcohol, ethylene glycol, ethylene glycol dimethyl ether, ethyl acetate, Glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-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, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, diphenylmethane, diisopropylnaphthalene, diisopropylbiphenyl, isopropylbiphenyl, petroleum fractions such as -type (from Exxon), alkylphenols such as tert-butylphenol, nonylphenol, dodecylphenol, cardanol, styrenated phenols, bisphenols, aromatic resins, in particular types containing phenolic groups, alkoxylated phenols, in particular ethoxylated or propoxylated phenols, in particular 2-phenoxyethanol, adipates, sebacates, phthalates, benzoates, organic phosphates or sulfonates or sulfonamides.

[0100] Preferred among them are diluents having a boiling point of more than 200° C., in particular benzyl alcohol, styrenated phenols, ethoxylated phenols, aromatic hydrocarbon resins containing phenolic groups, such as in particular Types LS 500, LX 200, LA 300 or LA 700 (from Rütgers), diisopropylnaphthalene, diisopropylbiphenyl, isopropylbiphenyl or cardanol, in particular benzyl alcohol.

[0101] The curing agent preferably contains only a small amount of diluent, in particular 0 to 30% by weight, particularly preferably 0 to 20% by weight, based on the total curing agent, of diluent. This enables particularly low-emission epoxy resin products.

[0102] The curing agent may be water-based and contain water in the range of 15 to 90 wt %, preferably 20 to 80 wt %.

[0103] The curing agent is preferably not water-based. Based on the entire curing agent, it preferably contains less than 15% by weight, especially less than 10% by weight of water. Such a curing agent is particularly suitable for non-aqueous epoxy resin products.

[0104] The curing agent may contain other ingredients, in particular:

[0105] - additional amines of formula (I),

[0106] - further adducts, in particular adducts of MPMD or 1,2-ethylenediamine or 1,2-propylenediamine with cresol glycidyl ether or aromatic epoxy resins, wherein unreacted MPMD, 1,2-ethylenediamine or 1,2-propylenediamine is removed by distillation after the reaction;

[0107] - monoamines, such as, in particular, benzylamine or furfurylamine;

[0108] - polyamidoamines, in particular reaction products of mono- or polycarboxylic acids or their esters or anhydrides (in particular dimerized fatty acids) with a polyamine (in particular DETA or TETA) used in a stoichiometric excess;

[0109] - Mannich base,

[0110] - aromatic polyamines, such as, in particular, 4,4′-, 2,4′- and / or 2,2′-diaminodiphenylmethane, 2,4(6)-toluenediamine, 3,5-dimethylthio-2,4(6)-toluenediamine or 3,5-diethyl-2,4(6)-toluenediamine;

[0111] - compounds having mercapto groups, in particular mercaptan-terminated polysulfide polymers, mercaptan-terminated polyoxyalkylene ethers, mercaptan-terminated polyoxyalkylene derivatives, polyesters of thiocarboxylic acids, 2,4,6-trimercapto-1,3,5-triazine, triethylene glycol dithiol or ethanedithiol in liquid form,

[0112] - surface-active additives, in particular defoamers, deaerators, wetting agents, dispersants or leveling agents, or

[0113] - Stabilizers, in particular stabilizers against oxidation, heat, light or UV rays.

[0114] Preferably, the curing agent contains 2% to 30% by weight, preferably 5% to 25% by weight, of polyphenols which are solid at room temperature, based on the sum of all liquid or dissolved components contained in the curing agent. Such curing agents enable easy-to-process epoxy resin coatings with particularly flawless curing at low temperatures. If the curing agent contains pigments, carbon black or mineral fillers, these do not contribute to the calculation of the polyphenol content.

[0115] Preferably, the amine hydrogen equivalent of the curing agent is 50 to 140 g / eq, preferably 55 to 120 g / eq, particularly preferably 60 to 100 g / eq, in particular 65 to 90 g / eq, based on the sum of all liquid or dissolved components contained in the curing agent. Such a curing agent enables low-emission epoxy resin coatings with high final hardness and particularly aesthetic surfaces (especially after curing at low temperatures).

[0116] The curing agent has a low viscosity. In particular, the viscosity of the curing agent at 20° C. measured by a cone-plate viscometer is in the range of 10 to 5000 mPa·s, preferably 10 to 1000 mPa·s, particularly preferably 10 to 500 mPa·s, and in particular 10 to 250 mPa·s, based on the sum of all liquid or dissolved components contained in the curing agent.

[0117] The curing agent containing the solution of the invention is particularly used for curing at least one epoxy resin. The solution can first be mixed with the other components and optionally stored as such. Alternatively, the solution is added as a separate component only when the curing agent is used to cure the epoxy resin.

[0118] Therefore, another subject of the present invention is an epoxy resin composition comprising a resin component containing at least one epoxy resin and

[0119] a curing agent component comprising a curing agent containing the solution of the invention and at least one other amine having at least three amine hydrogens, as described above,

[0120] or

[0121] A curing agent component comprising at least one amine having at least three amine hydrogens and, as a separate third component, a solution according to the invention.

[0122] Suitable epoxy resins are obtainable in a known manner, in particular by reaction of epichlorohydrin with polyols, polyphenols or amines.

[0123] Suitable epoxy resins are in particular aromatic epoxy resins, in particular the glycidyl ethers of:

[0124] Bisphenol A, bisphenol F or bisphenol A / F, where A is acetone and F is formaldehyde, serve as reactants for the preparation of the bisphenols. In the case of bisphenol F, positional isomers, in particular derived from 2,4′- or 2,2′-hydroxyphenylmethane, may also be present.

[0125] - dihydroxybenzene derivatives such as resorcinol, hydroquinone or catechol;

[0126] - other bisphenols or polyphenols such as bis(4-hydroxy-3-methyl-phenyl)methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane (bisphenol-C), bis(3,5-dimethyl-4-hydroxy-phenyl)methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane (bisphenol-B), 3,3-bis(4-hydroxyphenyl)pentane, 3,4-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)heptane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methyl butane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol-Z), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol-TMC), 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol-P), 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol-M), 4,4'-dihydroxybiphenyl (DOD), 4,4'-dihydroxybenzophenone, bis(2-hydroxynaphthalen-1-yl)methane, bis(4-hydroxynaphthalen-1-yl)methane, 1,5-dihydroxynaphthalene, tris(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)ether or bis(4-hydroxyphenyl)sulfone;

[0127] - novolacs, in particular condensation products of phenol or cresol with formaldehyde or paraformaldehyde or acetaldehyde or crotonaldehyde or isobutyraldehyde or 2-ethylhexanal or benzaldehyde or furfural;

[0128] Aromatic amines, for example aniline, p-toluidine, 4-aminophenol, 4,4′-methylenediphenyldiamine, 4,4′-methylenediphenyldi-(N-methyl)amine, 4,4′-[1,4-phenylene-bis(1-methylethylidene)]diphenylamine (diphenylamine-P) or 4,4′-[1,3-phenylene-bis(1-methylethylidene)]diphenylamine (diphenylamine-M).

[0129] Other suitable epoxy resins are aliphatic or cycloaliphatic polyepoxides, in particular

[0130] - saturated or unsaturated, branched or unbranched, cyclic or open-chain, difunctional, trifunctional or tetrafunctional, C2- to C 30 - glycidyl ethers of alcohols, in particular ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, octanediol, polypropylene glycol, dimethylolcyclohexane, neopentyl glycol, dibromoneopentyl glycol, castor oil, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol or glycerol, or alkoxylated glycerol or alkoxylated trimethylolpropane;

[0131] - hydrogenated bisphenol-A-, -F- or -A / F-liquid resins, or glycidylation products of hydrogenated bisphenol-A-, -F- or -A / F;

[0132] -amides or N-glycidyl derivatives of heterocyclic nitrogenous bases, such as triglycidyl cyanurate or triglycidyl isocyanurate, or the reaction products of epichlorohydrin and hydantoin.

[0133] The epoxy resin is preferably a liquid resin or a mixture comprising two or more liquid epoxy resins.

[0134] "Liquid epoxy resin" means a commercial polyepoxide having a glass transition temperature below 25°C.

[0135] The resin component optionally further comprises a certain amount of solid epoxy resin.

[0136] The epoxy resin is in particular a liquid resin based on bisphenol or novolac, in particular a liquid resin having an average epoxy equivalent weight in the range of 156 to 210 g / eq.

[0137] Particularly suitable are bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether, such as those commercially available from Ol in, Huntsman or Momentive. These liquid resins have a lower viscosity than epoxy resins and enable fast curing and high hardness. They may contain a certain amount of bisphenol A solid resin or novolac epoxy resin.

[0138] Also particularly suitable are phenol-formaldehyde novolac glycidyl ethers having an average functionality of 2.3 to 4, preferably 2.5 to 3. These may contain certain proportions of other epoxy resins, in particular bisphenol A diglycidyl ether or bisphenol F diglycidyl ether.

[0139] The resin component may contain a reactive diluent.

[0140] Preferred reactive diluents are reactive diluents containing epoxy groups, in particular butanediol diglycidyl ether, hexanediol diglycidyl ether, trimethylolpropane di- or triglycidyl ether, phenyl glycidyl ether, cresol glycidyl ether, guaiacol glycidyl ether, 4-methoxyphenyl glycidyl ether, p-n-butylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, 4-nonylphenyl glycidyl ether, 4-dodecylphenyl glycidyl ether, cardanol glycidyl ether, benzyl glycidyl ether, allyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, 2-ethylhexyl glycidyl ether or glycidyl ethers of natural alcohols, for example, in particular C8- to C6-containing alcohols. 10 - or C 12 - to C 14 - or C 13 - to C 15 -Alkyl glycidyl ether.

[0141] In one embodiment, the curing agent component comprises the above-described curing agent containing solution of the present invention.

[0142] In another embodiment, the curing agent component comprises at least one amine having at least three amine hydrogens and the solution of the present invention is present as a separate third component.

[0143] Preferably, the epoxy resin composition comprises at least one further ingredient selected from diluents, accelerators, fillers, pigments and surface active additives.

[0144] Suitable diluents or promoters are in particular those mentioned above.

[0145] Suitable fillers are in particular ground calcium carbonate or precipitated calcium carbonate optionally coated with fatty acids (in particular stearates), barite (settled crystal stone), talcum, quartz powder, quartz sand, silicon carbide, mica iron ore, dolomite, wollastonite, kaolin, mica (potassium-aluminum-silicate), molecular sieves, aluminum oxide, zinc oxide, aluminum-doped zinc oxide, aluminum hydroxide, magnesium hydroxide, silicon dioxide, cement, gypsum, fly ash, carbon black, graphite, metal powders such as aluminum, copper, iron, zinc, silver or steel, PVC-powder or hollow spheres. Among them, calcium carbonate, barite, quartz powder, talcum, aluminum powder or a combination thereof are preferred.

[0146] Suitable pigments are in particular titanium dioxide, iron oxide, chromium(III) oxide, organic pigments, carbon black or anticorrosive pigments, in particular phosphates, orthophosphates or polyphosphates which contain, in particular, chromium, zinc, aluminum, calcium, strontium or a combination of these metals as counterions. Titanium dioxide is particularly suitable.

[0147] Suitable surface-active additives are, in particular, defoamers, deaerators, wetting agents, dispersants, leveling agents and / or dispersing waxes.

[0148] The epoxy resin composition optionally contains other auxiliaries and additives, in particular:

[0149] - reactive diluents, in particular those already mentioned above, or epoxidized soybean oil or linseed oil, compounds having acetoacetate groups, in particular acetoacetated polyols, butyrolactone, carbonates, aldehydes, isocyanates or silicones having reactive groups,

[0150] polymers, in particular polyamides, polysulfides, polyvinyl formal (PVF), polyvinyl butyral (PVB), polyurethanes (PUR), polymers containing carboxyl groups, polyamides, butadiene-acrylonitrile copolymers, styrene-acrylonitrile copolymers, butadiene-styrene copolymers, homopolymers or copolymers of unsaturated monomers, in particular selected from ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate or alkyl (meth)acrylates, in particular chlorosulfonated polyethylene or fluorinated polymers or sulfonamide-modified melamine,

[0151] - fibers, in particular glass fibers, carbon fibers, metal fibers, ceramic fibers or plastic fibers, such as polyamide fibers or polyethylene fibers,

[0152] - nanofillers, especially carbon nanotubes,

[0153] - rheology modifiers, in particular thickeners or anti-settling agents,

[0154] - adhesion promoters, in particular organoalkoxysilanes,

[0155] flame retardants, in particular the fillers already mentioned, aluminum hydroxide or magnesium hydroxide, antimony trioxide, antimony pentoxide, boric acid, zinc borate, zinc phosphate, melammonium borate, melammonium cyanurate, ammonium polyphosphate, melammonium phosphate, melammonium pyrophosphate, polybrominated diphenyl oxide or diphenyl ether, phosphates such as, in particular, diphenylcresyl phosphate, resorcinol-bis(diphenyl phosphate), resorcinol-diphosphat oligomers, tetraphenylresorcinol diphosphite, ethylenediamine diphosphate, bisphenol A-bis(diphenyl phosphate), tris(chloroethyl)phosphate, tris(chloropropyl)phosphate, tris(dichloroisopropyl)phosphate, tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate, tetrabromo-bisphenol A, bis(2,3-dibromopropyl ether) of bisphenol A, brominated epoxy resin, ethylene-bis(tetrabromophthalimide), ethylene-bis(dibromonorbornanedicarboximide), 1,2-bis-(tribromophenoxy)ethane, tris(2,3-dibromopropyl)isocyanurate, tribromophenol, hexabromocyclododecane, bis(hexachlorocyclopentadienyl)cyclooctane, or chlorinated paraffin, or

[0156] - Stabilizers or biocides against oxidation, heat, light or UV rays.

[0157] The epoxy resin composition preferably contains only a relatively low content of diluent. It preferably contains less than 20% by weight, particularly preferably less than 10% by weight, in particular less than 5% by weight, and most preferably less than 1% by weight of diluent. Such epoxy resin products are particularly low-emission.

[0158] The epoxy resin composition may contain water.

[0159] In one embodiment, the epoxy resin composition is water-based. The epoxy resin is preferably emulsified in water in an amount of 50 to 85 wt %, and the curing agent component preferably comprises 20 to 80 wt % water.

[0160] Preferably, the epoxy resin composition contains only a small amount of water, preferably less than 5% by weight, in particular less than 1% by weight of water. Such non-aqueous epoxy resin compositions are particularly versatile and particularly water-resistant.

[0161] The resin component, the curing agent component and, if present, the third component or the solution of the invention are stored in containers separate from one another. Suitable containers are in particular barrels, bottles, bags, buckets, cans, magazines or tubes. The components are storable, i.e. they can be stored for several months to a year and longer before use without changing their respective properties to an extent relevant to their use.

[0162] If the solution of the invention is present as a constituent of the hardener component, the resin component and the hardener component are mixed with one another only immediately before or during application.

[0163] If the solution of the invention is present as a separate third component, the three components are mixed with one another only immediately before or during application. Any order is possible here. It is preferred to mix all three components together, or to first mix the curing agent component and the third component and then mix with the resin component. It is also possible, but less preferred, to first mix the resin component and the curing agent component and then mix the third component.

[0164] The mixing ratio of the components is preferably selected so that the molar ratio of the groups reactive toward epoxy groups to the epoxy groups is in the range of 0.5 to 1.5, in particular 0.7 to 1.2, and so that the polyphenol content in the curing agent is in the above-mentioned preferred range. The mixing ratio between the resin component and the curing agent component is usually in the range of 1:2 to 20:1 in parts by weight.

[0165] The components are mixed continuously or batchwise by suitable methods, ensuring that not too much time elapses between mixing and application of the components and that application is carried out within the pot life. Mixing and application are preferably carried out at ambient temperature, which is typically in the range of about 5 to 40° C., preferably about 10 to 35° C.

[0166] With the mixing of the components, curing of the epoxy resin composition begins by chemical reaction. The primary and secondary amino groups and optionally other groups reactive to epoxy groups react with the epoxy groups by ring opening thereof. The main result of the reaction is polymerization of the composition and final curing.

[0167] Curing usually lasts from a few hours to a few days. The duration depends mainly on the temperature, the reactivity of the ingredients, their stoichiometry, the content of polyphenols and the presence or amount of other accelerators.

[0168] The epoxy resin composition has a low viscosity in the freshly mixed state. Preferably, the viscosity at 20° C. measured by means of a cone-plate viscometer as described above 5 minutes after the components have been mixed is in the range of 0.1 to 20 Pa·s, preferably 0.2 to 10 Pa·s, particularly preferably 0.3 to 5 Pa·s.

[0169] The epoxy resin composition is applied to at least one substrate and / or to at least one casting mold.

[0170] Suitable substrates are in particular:

[0171] - glass, glass ceramics, concrete, mortar, cement flooring, fibre cement, brick, tile, plaster or natural stone such as granite or marble;

[0172] - Repair or levelling materials based on PCC (polymer modified cement mortar) or ECC (epoxy modified cement mortar);

[0173] - metals or alloys, such as aluminium, iron, steel, copper, other non-ferrous metals, including metals or alloys with surface treatments, such as zinc-plated or chromium-plated metals;

[0174] - tar or bitumen;

[0175] - leather, fabric, paper, wood, wooden materials combined with resins (for example phenolic resins, melamine resins or epoxy resins), resin-fabric composites or other so-called polymer composites;

[0176] - plastics, for example hard and soft PVC, polycarbonate, polystyrene, polyester, polyamide, PMMA, ABS, SAN, epoxy resins, phenolic resins, PUR, POM, TPO, PE, PP, EPM or EPDM, each untreated or surface-treated, for example by plasma, corona or flame;

[0177] - Fiber-reinforced plastics, such as carbon fiber-reinforced plastics (CFK), glass fiber-reinforced plastics (GFK) and sheet molding compounds (SMC);

[0178] - insulating foams, in particular made of EPS, XPS, PUR, PIR, asbestos, glass wool, aerogel or expanded glass (cellular glass);

[0179] - coated or painted substrates, in particular painted tiles, coated concrete, powder-coated metals or alloys or painted sheets;

[0180] - Paints, coatings or lacquers, in particular coated floor coverings covered by other floor coverings.

[0181] If necessary, the substrate can be pretreated before application, in particular by physical and / or chemical cleaning methods or by application of activators or primers.

[0182] In particular, the substrate is coated and / or bonded.

[0183] Suitable casting molds are devices into which the mixed liquid epoxy resin composition is cast and in which it cures, and from which it can be demolded or removed after curing, the cured composition forming a shaped body.

[0184] Preferably, at least the surface of the casting mold consists of a material from which the cured epoxy resin composition can be separated again without damage, in particular metal, ceramic, plastic or silicone, optionally with an anti-stick coating, in particular Teflon, silicone or wax.

[0185] Another subject of the present invention is a cured composition which is obtained from the epoxy resin composition after mixing the individual components.

[0186] The epoxy resin composition is preferably used as a coating, primer, adhesive, sealant, casting compound, casting resin, impregnation resin, injection resin, anchoring adhesive, adhesive mortar or as a matrix for shaped parts or composite materials.

[0187] The epoxy resin composition is particularly preferably used as a coating, in particular as a floor coating, wall coating, component coating, pipeline coating, tank interior coating, roof coating or protective coating, in particular anticorrosive coating.

[0188] The solutions according to the invention enable epoxy resin products having particularly advantageous properties to be achieved. The polyphenols can be metered in particularly easily without the use of diluents or solvents, and particularly low-emission epoxy resin coatings are obtained which have rapid curing, particularly low tendency to cause surface defects by haze, high final hardness, and surprisingly defect-free curing at low temperatures. These advantageous properties can be achieved even with low doses of the solutions according to the invention, so that the processability of such coatings is very good even without diluents.

[0189] Particularly defect-free curing at low temperatures is manifested by the following Comparison of hardness:

[0190] a) After curing for 7 days at 8°C / 80% RH followed by post-curing for 14 days at 23°C / 50% RH Hardness, and

[0191] b) After curing for 14 days at 23°C / 50% relative humidity hardness,

[0192] The epoxy resin coating of the present invention achieves Hardness a), and the Hardness a) corresponds almost or completely to Hardness b). In particular, the epoxy resin coating of the present invention achieves The value of hardness a) corresponds to At least 70%, preferably at least 80%, particularly preferably at least 90% of the value of hardness b).

[0193] The epoxy resin coatings according to the invention enable such a particularly defect-free curing, in particular even with no or only small amounts of diluents such as benzyl alcohol. Such epoxy resin coatings therefore have particularly low emissions and are particularly robust with regard to environmental conditions during processing and durability during use.

[0194] Example

[0195] Examples are described below which explain the invention in more detail. The invention is of course not limited to the examples described.

[0196] "AHEW" stands for amine hydrogen equivalent weight.

[0197] "EEW" stands for epoxide equivalent weight.

[0198] "Standard climate" ("NK") means a temperature of 23±1° C. and a relative air humidity of 50±5%.

[0199] If not stated otherwise, the chemicals used were from Sigma-Aldrich Chemie GmbH.

[0200] Substances and abbreviations used

[0201] GY 250: Bisphenol A diglycidyl ether, EEW about 187g / eq (Huntsman)

[0202] DY-E:C 12 To C 14Monoglycidyl ether of alcohol, EEW about 290g / eq (Huntsman)

[0203] DY-H: hexanediol diglycidyl ether, EEW about 147 g / eq (Huntsman) B-EDA: N-benzyl-1,2-ethylenediamine, 150.2 g / mol, AHEW 50.1 g / eq, prepared as follows

[0204] B-EDA mixture: a reaction mixture containing N-benzyl-1,2-ethylenediamine and N,N'-diphenylmethyl-1,2-ethylenediamine in a weight ratio of 85 / 15 prepared as follows, AHEW 55 g / eq

[0205] F-EDA: N-furfuryl-1,2-ethylenediamine, 140.1 g / mol, AHEW 46.7 g / eq, prepared as follows

[0206] B-PDA: N-benzyl-1,2-propylenediamine, 164.4 g / mol, AHEW 54.8 g / eq, prepared as follows

[0207] DMAPAPA: 3-(3-dimethylaminopropylamino)propylamine, AHEW 53 g / eq (DMAPAPA from Arkema)

[0208] IPDA 3-aminomethyl-3,5,5-trimethylcyclohexylamine, AHEW 42.6g / eq( IPD, Evonik)

[0209] MXDA: 1,3-bis(aminomethyl)benzene, AHEW 34g / eq (Mitsubishi Gas Chemical)

[0210] BAC 1,3-bis(aminomethyl)cyclohexane, AHEW 35.5 g / eq (from Mitsubishi Gas Chemical)

[0211] Phenolic resin PH-1 phenol-formaldehyde novolac, average molecular weight M n About 430g / mol, softening point 65 to 75℃ ( PN 327 / 100, from Allnex)

[0212] Phenolic resin PH-2 phenol-formaldehyde novolac, average molecular weight M n About 440g / mol, softening point 65 to 75℃ ( 3616 from Süd-West-Chemie)

[0213] Phenolic resin PH-3 phenol-formaldehyde novolac, average molecular weight M n About 950g / mol, softening point 78 to 82℃ ( TD-2131, from DIC)

[0214] Phenolic resin PH-4 phenol-formaldehyde novolac, average molecular weight M n About 2,400g / mol, softening point 108 to 120℃ ( PN 320, from Allnex)

[0215] Phenolic resin PH-5 phenol-formaldehyde novolac, average molecular weight M n About 2,600g / mol, softening point 95 to 110℃ ( FB8000SH, from Sumimoto Bakelite)

[0216] DPA diphenolic acid (4,4-bis(4-hydroxyphenyl)valeric acid)

[0217] K54 2,4,6-Tris(dimethylaminomethyl)phenol( K54, from Evonik)

[0218] Reaction mixture containing N-benzyl-1,2-ethylenediamine (B-EDA mixture):

[0219] 180.3 g (3 mol) of 1,2-ethylenediamine were charged at room temperature, mixed with a solution of 106.0 g (1 mol) of benzaldehyde in 1200 ml of isopropanol, hydrogenated in a continuously operating hydrogenation apparatus with a Pd / C fixed-bed catalyst at 80° C., 80 bar hydrogen pressure and an H2 flow rate of 5 ml / min, and the hydrogenated solution was freed from volatile components on a rotary evaporator at 65° C. A yellow, transparent liquid was obtained, which had an N-benzyl-1,2-ethylenediamine content of about 81% by weight, determined by GC, an N,N′-dibenzyl-1,2-ethylenediamine content of about 14% by weight, an 1,2-ethylenediamine content of 0.3% by weight, and a calculated AHEW of 55 g / eq, which was used hereinafter as B-EDA mixture.

[0220] N-Benzyl-1,2-ethylenediamine (B-EDA):

[0221] A portion of the reaction mixture containing N-benzyl-1,2-ethylenediamine (B-EDA mixture) prepared as described above was purified by vacuum distillation at 80° C. A colorless liquid was obtained with an AHEW of 50.1 g / eq and an N-benzyl-1,2-ethylenediamine content of >97% determined by GC, which was used hereinafter as B-EDA.

[0222] N-Furfuryl-1,2-ethylenediamine (F-EDA):

[0223] 105.2 g (1.75 mol) of 1,2-ethylenediamine were charged at room temperature, mixed with a solution of 48.1 g (0.5 mol) of furfural in 1200 ml of isopropanol, hydrogenated at 80° C., 80 bar hydrogen pressure and 5 ml / min H2 flow rate in a continuously operated hydrogenation apparatus with a Pd / C fixed bed catalyst, and the hydrogenated solution was freed from volatile components on a rotary evaporator at 65° C. The resulting reaction mixture was purified by vacuum distillation at 70° C. A colorless liquid was obtained, which had an AHEW of 46.7 g / eq and a content of 94.6% by weight of N-furfuryl-1,2-ethylenediamine and 5.3% by weight of N-tetrahydrofurfuryl-1,2-ethylenediamine determined by GC, and was used as F-EDA hereinafter.

[0224] N-Benzyl-1,2-propylenediamine (B-PDA):

[0225] 222.4 g (3 mol) of 1,2-propylenediamine were introduced at room temperature, mixed with a solution of 106.0 g (1 mol) of benzaldehyde in 1200 ml of isopropanol, hydrogenated in a continuously operating hydrogenation apparatus with a Pd / C fixed bed catalyst at 80° C., 80 bar hydrogen pressure and a H2 flow rate of 5 ml / min, and the hydrogenated solution was freed from volatile components on a rotary evaporator at 65° C. The resulting reaction mixture was purified by vacuum distillation at 80° C. A colorless liquid was obtained with an AHEW of 54.8 g / eq and a content of N-benzyl-1,2-propylenediamine determined by GC of >97% by weight, according to 1 H-NMR determination of N 1 -Benzyl-1,2-propylenediamine and N 2 -benzyl-1,2-propylenediamine was used as B-PDA in the following text in a ratio of about 2 / 1.

[0226] Solution preparation:

[0227] Solutions L-1 to L-28:

[0228] According to Table 1 and Table 2, for each solution, the designated amine was preliminarily charged, heated to 50 to 80° C., a designated amount of polyphenol was dissolved in the amine with stirring, and the solution was cooled to room temperature.

[0229] After storing the solution at room temperature for 24 h, the viscosity of the solution was measured at the specified temperature on a thermostatic cone and plate viscometer Rheotec RC30 (cone diameter 50 mm, cone angle 1°, distance from cone tip to plate 0.05 mm), where 100 s was used for viscosities less than 100 mPa·s. -1 For viscosities of 100 mPa·s or higher, use 10 s -1 The shear rate.

[0230] Solutions denoted by "(Ref.)" are comparative examples not of the present invention.

[0231]

[0232]

[0233] Table 1: Composition and viscosity of solutions L-1 to L-22.

[0234] 1 Amine / phenolic resin weight ratio

[0235]

[0236] Table 2: Composition and viscosity of solutions L-23 to L-28.

[0237] 1 Amine / polyphenol weight ratio

[0238] Preparation of epoxy resin curing agent:

[0239] Curing agent H-1 to H-19:

[0240] For each curing agent, a centrifugal mixer (SpeedMixer TM DAC 150, FlackTek Inc.) The ingredients specified in Table 3 were mixed in the specified amounts (parts by weight) and stored while excluding moisture.

[0241] The viscosity of the curing agent was measured as described above.

[0242] The amine equivalent weight (AHEW) of the curing agent is calculated.

[0243] The results are listed in Table 3.

[0244] The curing agents indicated by "(Ref.)" are comparative examples not related to the present invention.

[0245]

[0246] Table 3: Composition (in wt %) and properties of curing agents H-1 to H-19.

[0247] "nb" means "not determined"

[0248] Preparation of epoxy resin composition

[0249] Compositions Z-1 to Z-19:

[0250] For each composition, the mixture was mixed by a centrifugal mixer (SpeedMixer TM DAC 150, FlackTek Inc.) The ingredients of the resin components specified in Tables 4 to 7 were mixed in the specified amounts (parts by weight) and stored with exclusion of moisture.

[0251] Subsequently, the curing agents specified in Tables 4 to 7 were mixed with the resin components in the specified amounts (parts by weight) using a centrifugal mixer, and the mixed compositions were immediately tested as follows:

[0252] The viscosity (5') was measured at a temperature of 20° C. 5 minutes after the resin component and the curing agent component were mixed as described above.

[0253] The gel time is determined by moving a freshly mixed amount of about 3 g with a spatula at regular intervals under standard conditions until the material gels.

[0254] The Shore D hardness was determined according to DIN 53505 on two cylindrical test pieces (20 mm diameter, 5 mm thickness), one of which was stored in a standard climate and one at 8° C. and 80% relative humidity, and the hardness was measured after 1 day (24 h) and after 2 days.

[0255] Furthermore, the films were applied to glass plates with a layer thickness of 500 μm and stored or cured under standard climate. The film properties were determined after 1 day, 2 days, 7 days and 14 days. Hardness (according to DIN EN ISO 1522 Pendulum hardness) (1dNK), (2d NK), (7dNK), (14d NK). The appearance of the films was evaluated after 14 days (NK). "Appearance" means a clear film with a shiny, non-tacky and structureless surface. "Structure" means any kind of markings or patterns on the surface.

[0256] A further film was applied to a glass plate with a layer thickness of 500 μm and immediately after application was left to cure at 8° C. and 80% relative humidity for 7 days and then left to cure at standard climate for 2 weeks. 24 hours after application, a polypropylene bottle cap was placed on the film, under which a damp sponge was placed. After a further 24 hours, the sponge and cap were removed and placed in a new position on the film, from which they were removed again and replaced 24 hours later, for a total of 4 times. The appearance of the film was then evaluated in the same way as described for appearance (NK) (indicated in the table by “Appearance (8° / 80%)”). The table also gives the number and type of visible marks produced in the film due to the damp sponge or the placed cap, respectively. “Haze” indicates the number of white spots. “(1)” indicates a faint white spot. “1” indicates a distinct white spot. “Ring” indicates the number of annular indentations that occur due to the sinking of the placed bottle cap. “(1)” indicates a faint bottle cap indentation, and “1” indicates a clear indentation. (The circular indentation indicates that the coating is not yet treadable.) Re-measure on the cured film Hardness: After 7 days at 8°C and 80% relative humidity ( (7d 8° / 80%)), then 2 days later under NK ( (+2dNK)) or after 7 days under NK ( (+7d NK)) or after 14 days under NK ( (+14d NK)).

[0257] As a measure of yellowing, the color change after loading was also determined in a weathering tester. For this purpose, a further film was applied to a glass plate with a layer thickness of 500 μm and stored or cured in a standard climate for 2 weeks and then loaded in a Q-Sun XenonXe-1 type weathering tester at 340 nm at a temperature of 65° C. for 72 hours (Q-Sun (72h)), the weathering tester having a filter Q-SUN Daylight-Q and a light intensity of 0.51 W / m 2 The color difference ΔE of the film thus loaded compared to the corresponding unloaded film was then determined by a colorimeter NH310 from Shenzen3NH Technology Co.LTD, which was provided with a silicon photodiode detector, illuminant A, and the color space measurement interface CIE L*a*b*C*H*. A ΔE-value of up to 5 indicates a slight yellowing.

[0258] The results are listed in Tables 4 to 7.

[0259] The compositions indicated by "(Ref.)" are comparative examples not related to the present invention.

[0260]

[0261] Table 4: Composition and properties of Z-1 to Z-7.

[0262] 1 Unmeasurable (too soft)

[0263] 2 Hardness (7d 8° / 80%+14d NK) relative to Percentage of hardness (14d NK)

[0264]

[0265] Table 5: Composition and properties of Z-8 to Z-11.

[0266] 1 Hardness (7d 8° / 80%+14d NK) relative to Percentage of hardness (14d NK)

[0267]

[0268] Table 6: Composition and properties of Z-12 to Z-15.

[0269] 1 Hardness (7d 8° / 80%+14d NK) relative to Percentage of hardness (14d NK)

[0270]

[0271] Table 7: Composition and properties of Z-16 to Z-19.

[0272] 1 Undetectable: Uneven mixing due to incompatibility of curing agent and resin components

[0273] 2 Hardness (7d 8° / 80%+14d NK) relative to Percentage of hardness (14d NK) Polyphenol solution used as a single component:

[0274] Compositions Z-20 to Z-22:

[0275] For these compositions, the indicated resin components in the indicated amounts (parts by weight) in Table 8 were used as the first component.

[0276] The specified curing agent component in the specified amount (parts by weight) in Table 8 was also used as the second component.

[0277] As the additional third component, the specified solution in the specified amount (parts by weight) in Table 8 was used.

[0278] The components of the respective composition were processed into a homogeneous liquid by means of a centrifugal mixer and immediately subjected to the following tests:

[0279] Viscosity, gel time and Shore D were tested as described for composition Z-1.

[0280] Furthermore, a film with a layer thickness of 500 μm was applied to a glass plate and stored at 8° C. and 80% relative humidity for 7 days. Here, 24 hours after application, a polypropylene bottle cap was placed on the film, under which a damp sponge was placed. After a further 24 hours, the sponge and the cap were removed and placed in a new position on the film, where they were removed again after 24 hours and replaced, a total of 4 times. The appearance of the film was then evaluated as described for the appearance of the composition Z-1 (8° / 80%).

[0281] The results are listed in Table 8.

[0282] The compositions denoted by "(Ref.)" are comparative examples.

[0283]

[0284] Table 8: Composition and properties of Z-20 to Z-22.

[0285] 1 Pigmented resin component for epoxy floor coatings, EEW 436 g / eq (from Sika) 2 Formulated unfilled curing agent for epoxy resin, AHEW 120 g / eq (from Sika).

Claims

1. A solution comprising 5 to 65% by weight of a polyphenol which is solid at room temperature and 35 to 95% by weight of an amine of formula (I), R-NH-A-NH2(I) in A represents a linear or branched alkylene group having 2 to 10 carbon atoms, and R represents a monovalent hydrocarbon radical which optionally contains oxygen atoms and has 1 to 12 carbon atoms, wherein the amine of formula (I) has a total of 8 to 15 carbon atoms and the two nitrogen atoms are separated from each other by at least two carbon atoms.

2. The solution according to claim 1, characterized in that The polyphenol which is solid at room temperature is selected from gallic acid, diphenolic acid, resveratrol, catechin and phenol-containing polymers, in particular phenolic resins.

3. The solution according to any one of claims 1 or 2, characterized in that The polyphenol which is solid at room temperature is a phenolic resin of formula (II), in The average value of n is 1 to 45, preferably 1 to 25, especially 1 to 8, and R 1 independently of one another represent H or an aliphatic hydrocarbon radical having 1 to 15 carbon atoms, preferably H, methyl or a straight-chain aliphatic C 15 - Hydrocarbyl.

4. The solution according to any one of claims 1 to 3, characterized in that A is selected from 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,3-butylene, 2-methyl-1,2-propylene, 1,3-pentylene, 1,5-pentylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene, 2-methyl-1,5-pentylene, 1,7-heptylene, 1,8-octylene, 2,5-dimethyl-1,6-hexylene, 1,9-nonylene and 1,10-decylene, in particular 1,2-ethylene.

5. The solution according to any one of claims 1 to 4, characterized in that R contains at least one aromatic or aliphatic ring and is particularly selected from benzyl, furfuryl, 2-phenylethyl, cyclohexylmethyl and tetrahydrofurfuryl.

6. The solution according to any one of claims 1 to 5, characterized in that It contains: 5 to 65% by weight, preferably 10 to 50% by weight and in particular 20 to 45% by weight of polyphenols which are solid at room temperature, 35 to 95% by weight, in particular 50 to 90% by weight, of an amine of the formula (I), and - 0% to 30% by weight of other amines and / or diluents and / or other accelerators not conforming to formula (I).

7. The solution according to claim 6, characterized in that It also includes - at least one amine of formula (Ia) and / or amine of formula (Ib) R -NH-A-NH-R(Ia) NH2-A-NH2(Ib) wherein A and R each represent the same group as in the corresponding amine of formula (I), - and / or amine-functional adducts of an amine of the formula (I) with at least one mono- or polyepoxide.

8. The solution according to any one of claims 1 to 7, characterized in that The viscosity at 20° C. measured by means of a cone and plate viscometer is in the range of 0.01 to 100 Pa·s, more preferably 0.02 to 50 Pa·s, more preferably 0.03 to 20 Pa·s, particularly 0.05 to 10 Pa·s.

9. Use of a solution according to any one of claims 1 to 8 for preparing a hardener for epoxy resins, wherein the hardener contains at least one further amine having at least three amine hydrogens.

10. The use according to claim 9, characterized in that The further amine having at least three amine hydrogens is selected from the group consisting of amines of formula (I), 1,5-diamino-2-methylpentane, 2-butyl-2-ethyl-1,5-pentanediamine, 2,2(4),4-trimethyl-1,6-hexanediamine, 1,2-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, isophoronediamine, 2 (4)-methyl-1,3-diaminocyclohexane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,3-bis(aminomethyl)benzene, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, N-(2-aminoethyl)-1,3-propylenediamine, N,N'-bis(3-aminopropyl)ethylenediamine, bis(hexamethylene)triamine, average molecular weight M n Polyoxypropylene diamine, average molecular weight M in the range of 200 to 500 g / mol n Polyoxypropylenetriamine in the range of 300 to 500 g / mol, 3-(3-(dimethylamino)propylamino)propylamine, 2,5-bis(aminomethyl)furan, 2,5-bis(aminomethyl)tetrahydrofuran, bis(5-aminomethylfuran-2-yl)methane, bis(5-aminomethyltetrahydrofuran-2-yl)methane, 2,2-bis(5-aminomethylfuran-2-yl)propane, 2,2-bis(5-aminomethyltetrahydrofuran-2-yl)propane, amine-functional adducts of the above amines with mono- or polyepoxides, phenalkamines and mixtures of two or more of the above amines.

11. The use according to any one of claims 9 or 10, characterized in that The curing agent contains 2% to 30% by weight, preferably 5% to 25% by weight, of polyphenols which are solid at room temperature, based on the sum of all liquid or dissolved components contained in the curing agent.

12. The use according to any one of claims 9 to 11, characterized in that The amine hydrogen equivalent of the curing agent is 50 to 140 g / eq, preferably 55 to 120 g / eq, particularly preferably 60 to 100 g / eq, and in particular 65 to 90 g / eq, based on the sum of all liquid or dissolved components contained in the curing agent.

13. The use according to any one of claims 9 to 12, characterized in that The viscosity of the curing agent at 20° C. measured by a cone and plate viscometer is in the range of 10 to 5000 mPa·s, preferably 10 to 1000 mPa·s, particularly preferably 10 to 500 mPa·s, and in particular 10 to 250 mPa·s, based on the sum of all liquid or dissolved components contained in the curing agent.

14. An epoxy resin composition comprising a resin component containing at least one epoxy resin and - a curing agent component comprising a curing agent according to any one of claims 9 to 13, or A curing agent component comprising at least one amine having at least three amine hydrogens and, as a separate third component, a solution according to any one of claims 1 to 8.

15. A cured epoxy resin composition obtained from the epoxy resin composition according to claim 14 after mixing the components.

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