Cross references to related applications
This application claims priority of the US provisional patent application serial number TO US. Patent No. 62/455,018, filed February 6, 2017, is expressly incorporated by reference in its entirety.
Federally Sponsored Research or Development Statement
not usable
the field of invention
The present description relates generally to curing agents comprising polyether amines, tertiary amines and glycerin. A curing agent can be combined with the epoxy resin to form a curable composition that can be applied to a substrate and cured to form a cured article.
Background of the invention
Curable compositions based on epoxy resins and various curing agents are widely used in industry for the production of cured epoxy resins. Typical representative examples of curing agents include diethylenetriamine, triethylenetetramine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, polyamide, dicyandiamide, hexaamine complexes of hydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl boronaphthalic anhydride and methyl boronaphthalic anhydride.
Polyetheramines have also been used to cure epoxy resins to provide cured articles that exhibit excellent physical properties in many applications such as composites, castings, adhesives, etc. (see, for example, WO 2016/089663; US Patent 8,399,577; US Patent Application Publication No. 2013/0012669; US Patent No. there is a need to develop a new agent A polyetheramine-based curing agent that has a reduced amount of polyetheramine to reduce raw material costs but still effectively cures epoxy resins to produce cured articles with acceptable physical and thermal properties.
Content of the invention
The present disclosure generally provides a curing agent comprising (i) a polyether amine, (ii) a tertiary amine substantially free of aromatic tertiary amines, (iii) glycerin.
In other aspects, curable compositions are provided comprising a curing agent of the present disclosure and an epoxy resin.
In yet another aspect, there is provided a cured article obtained by applying a curable composition to a substrate and curing the curable composition.
Detailed description of the invention
The present disclosure generally provides a curing agent comprising (i) a polyether amine selected from the group consisting of polyether monoamines, polyether diamines, polyether triamines, multifunctional polyether amines, and mixtures thereof; (ii) tertiary amines substantially free of aromatic tertiary amines; (iii) glycerol. Surprisingly, it has been found that this combination of components not only produces a curing agent at a much lower cost than known polyetheramine based curing agents, but also allows rapid curing of epoxy resins to provide cured articles with a excellent physical and thermal balance.
The following terms have the following meanings:
As used herein, the term "curing" or "curing" refers to the curing of an epoxy resin by chemical crosslinking. The term "curable" means that the composition is capable of being subjected to conditions that bring the composition to a hardened or thermosetting state or condition.
The term "alkyl" refers to straight or branched chain alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, and pentyl.
The term "aromatic tertiary amine" refers to a tertiary amine containing an aryl moiety, and the term "aryl" refers to a substituted or unsubstituted aromatic carbocyclic group having 6 to 14 carbon atoms.
The term "cycloalkyl" refers to an alicyclic group containing from 3 to 10 carbon atoms, including, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.
The term "heterocycloalkyl" includes heterocycloalkyl groups containing from 3 to 6 carbon atoms and one or two oxygen, sulfur or nitrogen atoms. Specific examples of such groups include azetidinyl, pyrrolidinyl, piperidinyl, homopiperidinyl, piperazinyl, homopiperazinyl, morpholinyl, and thiomorpholinyl.
The term "substantially free" means that when used to indicate that a material is substantially absent from a formulation, that material is either absent or, if present, present as an incidental impurity or by-product. In other words, the material does not affect the properties of the formulation.
The term "complete" and its derivatives are not intended to exclude the presence of additional components, steps, or procedures, whether or not described herein. For the avoidance of doubt, all compositions claimed herein, when the term "comprising" is used, may include additional additives or compounds, unless otherwise indicated. In contrast, the phrase "consisting essentially of", if it appears here, excludes from the scope of any subsequent statement any other components, steps or procedures, except those essential to the operation and the phrase "consisting of...consisting of " is not essential and, if used, does not include any component, step, or procedure that is not specifically described or stated. Unless otherwise indicated, the term "or" refers to members listed individually as well as in any combination.
The articles "a" and "an" are used here to refer to one or more (ie at least one) of the grammatical object of the article. For example, "epoxy resin" means one epoxy resin or more than one epoxy resin.
Phrases like "in one aspect", "according to one aspect", etc. they generally mean that the particular feature, structure, or characteristic that follows the phrase is included in at least one aspect of the disclosure and may be included in more than one aspect. of the publication. . It is important that these stages do not necessarily refer to the same aspect.
If a specification indicates that a component or function "may", "may", "may" or "could" contain or have a function, then that component or function need not contain or have that function.
hardener
According to one aspect, the curing agent of the present disclosure includes: (i) a polyether amine selected from the group consisting of: polyether monoamine; polyetherdiamine; polyether triamine; multifunctional polyetheramine and mixtures thereof; ii) tertiary amines substantially free of aromatic tertiary amines (iii) glycerol.
In one aspect, the polyether amine is a polyether monoamine of formula (1) or (1a):
where R is hydrogen, methyl or ethyl, and
a and b are independently an integer of approx. 1 to approx. 150; either
where Y is hydrogen, methyl or ethyl,
Z is a C1-C40Rental Salesperson C1-C40Alkylphenol and
w is an integer of approx. 1 to approx. 100.
In another aspect, the polyether amine is a polyether monoamine of formula (2) or (2a):
where Me is methyl and Et is ethyl.
Commercially available polyether monoamines include JEFFAMINE® M-Series and XTJ-Series amines, including but not limited to JEFFAMINE® M-600, M-1000, M-2005, M-2070, XTJ-435, and XTJ-Amines. 436, available from Huntsman Petrochemical LLC Acquisition.
In another aspect, the polyether amine is a polyether diamine of formula (3), (4) or (5):
where c is an integer of approx. 2 to approx. 100,
H is hydrogen, Me is methyl, Et is ethyl,
where H is hydrogen, Me is methyl, Et is ethyl,
e is an integer of approx. 2 to approx. 40, and
d and f are independent integers of approx. 1 to approx. 10; either
where g is an integer from about 2 to about 3.
Commercially available polyether diamines include JEFFAMINE® D, ED and EDR amines, including but not limited to JEFFAMINE® D-230, D-400, D-2000, D-4000, ED-600, ED-900, ED-20003 , EDR-148 and EDR-176 amines were purchased from Huntsman Petrochemical LLC.
In another aspect, the polyether amine is a polyether triamine of formula (6):
where R1Hydrogen, methyl or ethyl,
H is hydrogen, Me is methyl, Et is ethyl,
n is an integer of 0 or 1, and
h, i and j are independent integers of approx. 1 to approx. 100.
Commercially available polyether triamines include the JEFFAMINE® T series of amines, including, but not limited to, JEFFAMINE® T-403, T-3000, and T-5000 amines, available from Huntsman Petrochemical LLC.
In another aspect, the polyetheramines are multifunctional polyetheramines. The multifunctional polyether amine can be a polyether diamine or triamine, such as those described herein, in which at least one hydrogen of the amine group is replaced by a hydroxyl group. For example, a multifunctional polyetheramine may have the formula (7)
where each R4y R5independent hydrogen or hydroxyl, provided that at least one of R4is hydrogen and at least one of R5is a hydroxyl group
H is hydrogen, Me is methyl, and Et is ethyl.
In a particular aspect, the polyether amine is selected from polyether monoamines, polyether diamines, and mixtures thereof. In another specific aspect, the polyether amine is a polyether diamine.
According to another aspect, the curing agent includes at least about 65% by weight of polyetheramine, where the weight percentage is based on the total weight of the curing agent. In another aspect, the curing agent includes at least about 70% by weight polyetheramine or at least ca. 75% by weight of polyetheramine, where the percentage by weight is based on the total weight of the curing agent. In another aspect, the curing agent includes polyetheramine in an amount of at least about 80% by weight or at least ca. 81% by weight or at least approx. 82% by weight or at least approx. 83% by weight or at least approx. 84% by weight. %, or at least approx. 85% by weight, where the % by weight is based on the total weight of the hardener.
In another aspect, the curing agent includes from about 65 to approx. 95% by weight of polyetheramine, where the percentages by weight refer to the total weight of the hardener. In another aspect, the curing agent includes from about 70 to ca. 90% by weight of polyetheramine, where the percentages by weight refer to the total weight of the hardener. In another aspect, the curing agent includes from about 75% by weight to ca. 85% by weight polyetheramine, where the weight percentages are based on the total weight of the curing agent.
Curing agents also include tertiary amines that are essentially free of aromatic tertiary amines. In one aspect, the tertiary amine is a compound of the formula NR7R8R9Where are they7, R8y R9regardless is C1-C10I rent; seller (b) R7y R8Connected as a heterocycloalkyl residue and R9it's a c1-C10I rent; seller (c) R7y R8regardless is C1-C10rent and R9is a cycloalkyl group.
Examples of tertiary amines include, but are not limited to, trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, triisopropylamine, triisobutylamine, dimethylaminocyclohexane, diethylaminocyclohexane, dimethylaminocyclohexane, cyclopentane, diethylaminocyclopentane, N-methylmorpholine, N-N-methylpyrrolidine, N-N- methyl. ethylpyrrolidine, N-n-propylpyrrolidine, N-isopropylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-n-propylpiperidine, N-isopropylpiperidine, N,N'-dimethylpiperazine, N,N'-diethylpiperazine, N,N'-dipropyl-deraflopiperazine and dipropyl -piperazine mixture. In a specific aspect, the tertiary amine is trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, dimethylaminocyclohexane, or N-methylmorpholine. In another aspect, the tertiary amine is dimethylaminocyclohexane or N-methylmorpholine.
In one aspect, the curing agent may comprise less than about 10 weight percent tertiary amine, where the weight percent is based on the total weight of the curing agent. In another aspect, the curing agent comprises less than about 8% by weight of tertiary amines or less than ca. 7.5% by weight of tertiary amines, where the percentages by weight are based on the total weight of the curing agent. In another aspect, the curing agent comprises a tertiary amine in an amount of less than about 5% by weight or less than ca. 4% by weight or less than approx. 3% by weight or less than approx. 2.5% by weight. or less than approx. 2% by weight or less than approx. 1% by weight, where the percentage by weight is based on the total weight of the curing agent.
In another aspect, the curing agent includes from about 0.1 to about. 10% by weight of a tertiary amine, the percentages by weight being based on the total weight of the hardener. In another aspect, the curing agent includes from about 0.5% by weight to ca. 5% by weight of a tertiary amine, the weight percentage being based on the total weight of the curing agent. In another aspect, the curing agent includes from about 1 to about. 3% by weight of a tertiary amine, the weight percentage being based on the total weight of the hardener.
Hardeners also include glycerin. In one aspect, the curing agent includes less than about 30% glycerin by weight, where the weight percent is based on the total weight of the curing agent. In another aspect, the curing agent comprises less than about 25% by weight glycerin or at least less than ca. 20% by weight of glycerin, where the percentages by weight are based on the total weight of the hardener. In another aspect, the curing agent comprises glycerin in an amount of less than about 15% by weight or less than ca. 14% by weight or less of approx. 13% by weight or less of approx. 12% by weight or less 11% by weight or less than 10% by weight, where the percentage by weight is based on the total weight of the hardener.
In another aspect, the curing agent includes from about 1 to about. 25% by weight of glycerin, where the percentage by weight refers to the total weight of the hardener. In another aspect, the curing agent includes from about 5% by weight to ca. 20% by weight of glycerin, where the percentage by weight is based on the total weight of the curing agent. In another aspect, the curing agent includes from about 10% by weight to ca. 15% by weight of glycerin, where the percentage by weight is based on the total weight of the hardener.
curable composition
According to another aspect, there is provided a curable composition comprising: (i) an epoxy resin, (ii) a curing agent according to the present disclosure comprising a polyetheramine as described above substantially free of aromatic tertiary amines, tertiary amines and glycerol .
In general, any epoxy group-containing compound is suitable for use as the epoxy resin of the present invention, such as the epoxy group-containing compound described in US Patent No. 5,577,36. US. Patent No. 5,476,748, which is incorporated herein by reference. Epoxy resins can be solid or liquid. In one embodiment, the epoxy resin is selected from the group consisting of: polyglycidyl epoxy compounds, non-glycidyl epoxy compounds, cresol novolac epoxy compounds, epoxyphenol novolac compounds, cresol novolac epoxy compounds, polyglycidyl epoxy compounds, non-glycidyl epoxy compounds, epoxy compounds of cresol novolak,
The epoxy polyglycidyl compound can be polyglycidyl ether, poly(β-methylglycidyl) ether, polyglycidyl ester or poly(β-methylglycidyl) ester. Synthesis and examples of polyglycidyl ethers, poly(β-methylglycidyl) ethers, polyglycidyl esters, and poly(β-methylglycidyl) esters are described in US Patent No. 5,888,883. US. Patent No. 5,972,563, which is incorporated herein by reference. For example, ethers can be obtained by reacting a compound with at least one free alcoholic and/or phenolic hydroxyl group with suitably substituted epichlorohydrin under basic conditions or in the presence of an acid catalyst, followed by basic treatment. The alcohols can be, for example, acyclic alcohols, such as ethylene glycol, diethylene glycol and higher poly(oxyethylene)diols, propane-1,2-diol or poly(oxypropylene)diols, propane-1,3-diols, butane-1,4 -diol, poly(oxytetramethylene)diol, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triols, glycerin, 1,1,1-trimethylolpropane, ditrimethylolpropane, pentaerythritol, and sorbitol . However, suitable glycidyl ethers can also be obtained from cycloaliphatic alcohols, such as 1,3- or 1,4-dihydroxycyclohexane, bis(4-hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)propane or 1,1 - bis(hydroxymethyl)cyclohex-3-ene, or they may have aromatic rings, such as N,N-bis(2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)diphenylmethane.
Particularly important representatives of polyglycidyl ethers or poly((3-methylglycidyl)ethers are based on monocyclic phenols, for example on resorcinol or hydroquinone, on polycyclic phenols, for example on bis(4-hydroxyphenyl)methane (bisphenol F), 2,2- bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)sulfone (bisphenol S), alkylated bisphenol Phenol A, F or S, triol extended bisphenol A, F or S, brominated bisphenol A, F or S S , hydrogenated bisphenol A, F or S, glycidol of phenols and phenols with side groups or ether chains, condensation products of phenols or cresols with formaldehyde obtained under acidic conditions, such as phenol novolacs and cresol novolacs, or dilicidyl siloxane.
Polyglycidyl esters and poly(β-methylglycidyl) esters can be prepared by reacting epichlorohydrin or glycerol dichlorohydrin or 3-methylepichlorohydrin with a polycarboxylic acid compound. The reaction is conveniently carried out in the presence of a base. The polycarboxylic acid compound can be, for example, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or dimerized or trimerized linoleic acid. However, it is also possible to use cycloaliphatic polycarboxylic acids, such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid or 4-methylhexahydrophthalic acid formic dicarboxylic acid. It is also possible to use aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, trimellitic acid or pyromellitic acid, or for example trimellitic acid and polyalcohols such as glycerol or 2,2-bis(4-hydroxycyclohexyl)propane.
Epoxy resins, on the other hand, are epoxy compounds without glycidyl. Non-glycidyl epoxy compounds can have a linear, branched, or cyclic structure. For example, one or more epoxy compounds may be included where the epoxy group forms part of an alicyclic or heterocyclic ring system. Others include epoxy-containing compounds with at least one epoxycyclohexyl group attached directly or indirectly to a group containing at least one silicon atom. Examples are described in US Patent No. US Patent No. 5,639,413, which is incorporated herein by reference. Still others include epoxides containing one or more cyclohexenyloxy groups and epoxides containing one or more cyclopentenyloxy groups.
Specific examples of non-glycidyl epoxy compounds include the following difunctional non-glycidyl epoxy compounds in which the epoxy group forms part of an alicyclic or heterocyclic ring system: bis(2,3-epoxycyclopentyl)ether, 1,2-bis(2 , 3-epoxycyclopentyloxy)ethane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-cyclohexane Oxy-6-methyl-cyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl) ethylene glycol bis(3,4-epoxy-6-methylcyclohexylmethyl), bis(3,4-epoxycyclohexylcarboxylate), ethylene glycol bis(3,4-epoxycyclohexylmethyl) adipate adipate.
In particular aspects, difunctional epoxy non-glycidyl compounds include cycloaliphatic difunctional epoxy non-glycidyl compounds, such as 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylalkanecarboxylate and 2,2'-bis-(3,4)-epoxycyclohexyl. )-propane, more preferably the former.
In another aspect, the epoxy resin is a poly(N-glycidyl) compound or a poly(S-glycidyl) compound. Poly(N-glycidyl) compounds can e.g. it is obtained by dehydrochlorination of reaction products of epichlorohydrin with amines containing at least two amine hydrogen atoms. These amines can be, for example, n-butylamine, aniline, toluidine, m-xylylenediamine, bis(4-aminophenyl)methane or bis(4-methylaminophenyl)methane. Other examples of poly(N-glycidyl) compounds include N,N'-diglycidyl derivatives of cycloalkylene ureas, such as ethylene urea or 1,3-propylene urea, and hydantoin N,N'-diglycidyl derivatives of urea, such as 5,5- dimethylhydantoin Examples of poly(S-glycidyl) compounds are di-S-glycidyl derivatives derived from glyceryl derivative dithiols such as ethane-1,2-dithiol or bis(4-mercaptomethylphenyl)ether.
Epoxy resins in which the 1,2-epoxy groups are attached to various heteroatoms or functional groups can also be used. Examples include N,N,O-triglycidyl derivatives of 4-aminophenol, glycidyl ethers/glycidyl esters of salicylic acid, N-glycidyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin or 2-glycidyloxy-1,3-bis (5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.
Other epoxide derivatives may also be used, such as vinylcyclohexene dioxide, limonene dioxide, limonene monoxide, vinylcyclohexene monoxide, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxy-6-methylcyclohexylmethyl-9,10-epoxystearate, and 1,2-bis(2,3-epoxy-2-methylpropoxy)ethylalkyl.
In addition, the epoxy resin may be a prereacted adduct of an epoxy resin, such as those described above, with a free hydrogen compound reactive with the epoxy groups. Typically, such active hydrogens are present on carboxylic acid groups, aromatic hydroxyl groups, amino groups, and mercapto groups.
The amount of epoxy resin used in the curable composition may depend on the target molecular weight and epoxy functionality. In some aspects, the curable composition may comprise the epoxy resin in an amount of from about 30% to ca. 85% by weight, where the weight percentage is based on the total weight of the curable composition. In other aspects, the curable composition can include the epoxy resin in an amount of from about 40 to about. 85% by weight or approx. 45 to approx. 80% by weight, where the weight percentages are based on the total weight of the curable material. composition.
In another aspect, the curable composition comprises the above curing agent of the present invention. In some aspects, the curable composition may comprise the curing agent in an amount of at least about 5% or at least 10% or at least 15% or at least 20% by weight of the curable composition, based on total weight.
In another aspect, in addition to the epoxy resins and curing agents of the present disclosure, the curable compositions may contain one or more additives useful for their intended use. For example, optional additives that may be used in the curable composition may include, but are not limited to, diluents (1,4-butanediol diglycidyl ether (BDDGE), 1,6-hexanediol diglycidyl ether (HDDGE), cresol diglycidyl ether (CGE) , C12-14 alkylglycidyl ether (AGE), trimethylolpropane triglycidyl ether (TMPTGE)), inert filler, reinforcing fibers (carbon fiber, glass fiber, aramid fiber, boron fiber, silicon carbide fiber), stabilizers , surfactants, flow modifiers, pigments or dyes, release agents, matting agents, degassing agents, flame retardants (such as inorganic flame retardants, halogenated flame retardants, phosphorous-containing materials and other non-halogenated flame retardants), cured (as carboxyl-terminated liquid nickel rubber) (CTBN), acrylic-terminated liquid butadiene-acrylonitrile rubber (ATBN), epoxy-terminated liquid butadiene-acrylonitrile rubber adducts (ETBN), liquid epoxy resin elastomer (LER ) and preformed core and cover rubber), cure initiators, cure inhibitors, wetting agents, processing aids, fluorescent compounds, UV stabilizers, antioxidants, impact modifiers, and mixtures thereof.
When present, the additive can be included in the curable composition in an amount of at least about the composition.
Furthermore, the curable compositions within the scope of the present disclosure may be free of solvents, also referred to as solvent-free. Alternatively, the curable compositions of the present disclosure may further comprise at least one organic or aqueous solvent. Typically, such a solvent or mixture of solvents is selected to provide a particular evaporation rate profile for the curable composition while maintaining solubility of the components of the curable composition.
Examples of solvents that can be used herein include, but are not limited to, aliphatic hydrocarbons, aromatic hydrocarbons, glycol ethers, amides, sulfoxides, sulfones, and mixtures thereof. Specific solvents may include, for example, hexane, heptane, octane, nonane, decane, toluene, xylene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-butyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, Glycol Methyl Ether Phenyl Ether, Tripropylene Glycol Methyl Ether, Diethylene Glycol Methyl Ether, Diethylene Glycol Ethyl Ether, Diethylene Glycol n-Butyl Ether, Diethylene Glycol Phenyl Ether, Butylene Glycol Methyl Ether, N,N-Dimethylformamide, N-Methylpyramide, N -methylpyramidal dimethylacetamide, Dimethylsulfoxide, Sulfolane and mixtures thereof.
In some aspects, the solvent can be included in the curable composition in an amount of from about 5% to approx. 95% by weight, where the weight percentage is based on the total weight of the curable composition and the solvent. In other aspects, the solvent can be used in an amount from about 10% by weight to ca. 60% by weight or from approx. 20% by weight to approx. 40% by weight, where the weight percentages are based on the curable composition and the solvent.
Formulation of curable compositions.
The curable composition is not particularly limited and can be prepared by stirring and mixing while heating as necessary. The curable composition of the present disclosure may be a multipack (eg, 2-pack) composition in which at least two components of the curable composition are manufactured separately and packaged in separate containers (or containers), curable composition La composition is obtained by mixing two or more separately prepared components (for example, part A is an epoxy resin and part B is a hardener) in a predetermined ratio before use. The stirring/mixing method is not particularly limited. E.g. Known or customary stirring and mixing devices may be used, such as mixers (dissolvers, homogenizers, static mixers, etc.), kneading machines, rollers, bead mills and planetary stirring devices. The stirred mixture can be skimmed under vacuum.
In another aspect, the curable composition of the present disclosure is a one-pot composition obtained by mixing components including the epoxy resin of the present disclosure and a curing agent in a container and then metering these components into a curable composition. The order of mixing is not critical, ie, the components can be mixed in any order to provide the curable compositions of the present disclosure. Any of the aforementioned optional additives may also be added.
In one aspect, the epoxy resin and hardener are combined such that the ratio of equivalents of reactive amine hydrogens in the hardener to equivalents of epoxide present in the curable composition is from about 0.2 to about. 1.3 or from approx. 0.4 to approx. 0.4 to around 0.9, or even around 0.5 to around 0.85, even around 0.6 to around 0.8, and in some cases around 0.65 to around 0 .75. In other aspects, the epoxy resin and hardener are combined in an epoxy:hardener weight ratio of at least about 1:1, or at least 1.2:1, or even at least approx. 1.5:1. In other aspects, the weight ratio of epoxy resin to curing agent can be at least 2:1, even at least 2.5:1, even at least ca. 3:1.
In addition, the components of the curable composition can be mixed and dispersed at a temperature capable of producing an effective curable composition with a low viscosity for the desired application. The temperature during mixing of the components can be approx. 0°C to approx. 100°C or from approx. 0°C to approx. 50°C.
fix article
According to another aspect, the curable composition, once formulated, can be contacted or applied to any suitable substrate and cured according to typical processes practiced in the industry to form a cured article. Cured articles herein include, but are not limited to, coatings, adhesives, building products, flooring products, or composite products.
Typical curing processes range from room temperature curing to high temperature curing using heat, radiation, or a combination of energy sources. The curable composition may be cured in one or more stages, such as the A and B stage cure that is often implemented in the industry. Alternatively, the curable composition can be further cured using a different temperature or energy source after the initial cure cycle.
The temperature at which the curing reaction can take place will depend on the particular epoxy resin and hardener used. Thus, in one aspect, the curing temperature can range from approx. 25°C to 200°C or from approx. 40°C to approx. 195°C or from approx. 45°C to approx. 190°C. 50°C to approx. 185°C or approx. 60°C to approx. 180°C or approx. 70°C at approx. 135°C. In other aspects, the curable composition can be cured at a temperature in the range of about 80°C to ca. 130°C.
The curable composition can be cured at the above curing temperature for an effective time to cure the epoxy resin and form a cured article. In some aspects, the curing time may be less than 72 hours. In other aspects, the curing time may be less than 48 hours or less than 24 hours or less than 16 hours or less than 12 hours or less than 10 hours or less than 8 hours or less than 6 hours. or less than Within 4 hours or less than 2 hours. In other aspects, the curing time may be less than 60 minutes or less than 45 minutes or less than 30 minutes.
In one aspect, the curable compositions described above can be used as coatings. For example, a method of forming a coated substrate may include the step of applying a curable composition to a substrate to form a coated substrate. The curable composition can be applied to the substrate by any known technique, such as by dipping, spraying, die coating, rolling, resin dipping, and contacting the substrate with a bath containing the curable composition. Types of substrates that can be coated include, for example, glass, wood, concrete, plastic, or those with a relatively high glass transition temperature (TGRAMS) and/or melting point, reinforcing fibers and metals. The substrate can be a flat sheet or roll of the desired material, or it can have more complex contours, such as tubes, pipes, wires, or other shapes.
In another particular aspect, the curable compositions are useful in industrial coating applications. Such industrial coatings can include surface protective coatings applied to a substrate that cure or crosslink to form a continuous film for decorative purposes as well as to protect the substrate. Protective coatings often contain organic polymeric binders, pigments, and various paint additives, where the polymeric binder acts as a liquid vehicle for the pigments and imparts rheological properties to the liquid paint coating. After curing or crosslinking, the polymeric binder hardens and acts as a binder for the pigment and provides adhesion of the dry paint film to the substrate. Pigments can be organic or inorganic and can contribute functionally to opacity and color as well as durability and hardness.
In another aspect, a powder coating can be obtained comprising the curable composition described herein together with suitable pigments, catalysts and additives. These powder coatings and coatings made from them can have a surprisingly good combination of properties. Depending on the choice and amount of epoxy resin, hardener and other optional additives, the resulting powder coatings can have good flowability, good chemical resistance, high gloss, high scratch resistance, good mechanical performance, good outdoor durability and good color stability.
In other aspects, the curable compositions described herein can form part of water-based and oil-based dispersions. For example, water dispersible coating compositions comprising the curable compositions described herein are useful in can and spiral coating compositions.
In yet another aspect, the curable composition can be prepared by contacting one or more surfaces of similar or dissimilar substrates to be bonded with the curable composition under conditions sufficient to cure the curable composition.The substrates are used as an adhesive in a method of Union. substrates together involving the application of pressure and/or heat.
In yet another aspect, the curable compositions are also useful in marine coatings, civil engineering applications, flooring, molding, crack or defect repair, casting, embedding, filament winding, encapsulation and laminating, and structural and electrical composites. For example, the compounds formed using the curable compositions described herein can be used in wind turbine blades and other applications.
In an alternative aspect, the curable composition can be used for encapsulation or coating by techniques well known in the industry, such as pultrusion, infusion, casting or coating. The properties of composite articles can be tailored for certain applications by adding reinforcing fibers.
Accordingly, in another aspect, there is provided a method of making a composite article comprising the steps of: (i) providing a reinforcing fiber layer or bundle; (ii) provide a curable composition; (iii) combining the reinforcing fibers with a curable cure (iv) of the coated and/or impregnated reinforcement at a temperature of at least approx. 60°C or at least approx. 120°C or even at least approx. Fiber 195°C.
Example
Examples 1 to 14. Bisphenol A epoxy resin (ARALDITE® GY 6010 epoxy resin) with polyetheramine (JEFFAMINE® D-230 amine), glycerol and tertiary amine (dimethylaminocyclohexane (DMCHA)) of the hardener mixed to form a curable composition as shown in Table 1 below. Each curable composition was cured at 80°C for three hours and then at 125°C for two hours. Next, the glass transition temperature of the resulting cured article was measured by DSC with Example 1 as a reference. The results below show that in order to react the glycerol in the polymer backbone, a tertiary amine catalyst is required. In fact, phase separation was observed when an insufficient amount of DMCHA was used.
Examples 15 and 16. Bisphenol A epoxy resin (ARALDITE® GY 6010 epoxy resin) with polyetheramine (JEFFAMINE® D-230 amine), glycerol and tertiary amine (N-methylmorpholine (NMM)) The curing agent was mixed to form the composition curable is shown in Table 2 below. Each curable composition was cured at 80°C for three hours and then at 125°C for two hours. Next, the glass transition temperature of the resulting cured object was measured by DSC.
To compare the properties of the final cured article, curable compositions based on Examples 1 (reference), 6 (15% by weight glycerol) and 8 (10% by weight glycerol) were evaluated. The results are given in Table 3 below.
The above results indicate that a portion of the polyetheramine in the hardener can be replaced by glycerol in epoxy-containing curable compositions without sacrificing the physical properties of the post-cured article.
While the manufacture and use of various embodiments of the invention have been described in detail above, it is to be understood that the invention provides many useful inventive concepts that can be practiced in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to implement and use the present invention and do not limit the scope of the present invention.