Composite resin comprising unsaturated phosphate ester compound

Abstract

The present invention relates to a reactive diluent system for use in a composite resin comprising (a) a reactive diluent composition comprising or consisting of an organophosphorus compound, and (b) an accelerator system comprising (i) at least one iron salt or complex; (ii) at least one transition metal salt or complex selected from cobalt and copper; and (iii) optionally at least one solvent.

Description

TECHNICAL FIELD

[0001] The present invention relates to a reactive diluent system for a composite resin comprising (a) a reactive diluent composition comprising an organic (meth)acrylate-based phosphorus compound, and (b) an accelerator system. BACKGROUND

[0002] Unsaturated (meth)acrylate-based phosphates, such as 2-hydroxyethyl methacrylate phosphate, are well known adhesion promoters in applications such as adhesives or coating resins, which provide improved adhesion to polar substrates. Furthermore, the introduction of (meth)acrylate-based phosphates can improve the corrosion protection of emulsion-based coating formulations due to the improved adhesion. In addition, it is also known that phosphorus-based compounds can improve the flame retardant properties. The introduction of unsaturated (meth)acrylate-based phosphates into a polymer resin results in the formation of a flame retardant material. Especially in composite applications such as transportation and construction, flame retardant properties are of high interest. In these fields of application, vinyl ester and unsaturated polyester resins are the main resin types used. These resins usually contain styrene as a reactive diluent. In addition to styrene, other reactive diluents or reactive solvents are used, such as vinyl toluene or (meth)acrylates. Unsaturated (meth)acrylate-based phosphates provide the option to be used as a reactive diluent to impart flame retardant properties. This is of particular interest for fields of application where flame retardancy and optical transparency need to be combined. Furthermore, unsaturated (meth)acrylate-based phosphates enhance the glass fiber adhesion in fiber reinforced plastics.

[0003] To cure a composite resin, usually a redox system is used, which comprises an oxidizing agent, such as a peroxide, and soluble cobalt ions as an accelerator. The accelerator increases the activity of the oxidizing agent at lower temperatures, such as room temperature (RT), and thus accelerates the curing. The cobalt ions can be present in the form of a cobalt salt and / or in the form of a cobalt complex.

[0004] However, a composite resin combined with an unsaturated phosphate does not cure sufficiently with a standard RT curing system based on cobalt. The phosphate reduces the stability of the cobalt complex and thus the activity of the accelerator. Furthermore, it is also known that cobalt-accelerated methyl ethyl ketone peroxide (MEKP) systems show a low ability to form radicals efficiently with acrylic monomers in the absence of styrene. The most common initiator / accelerator system currently put into practice with acrylic resin systems is benzoyl peroxide (BPO) with a tertiary amine accelerator. However, the use of amines is less desirable due to the potential salt formation with unsaturated phosphates and the known discoloration issues caused by exposure of the final composite to light or heat. SUMMARY

[0005] It is therefore an object of the present invention to provide a suitable accelerator system for such phosphate reactive diluents. In other words, the problem to be solved by the present invention is to provide a reactive diluent system comprising an organic (meth)acrylate-based phosphorus compound as reactive diluent and an optimized accelerator system. SUMMARY

[0007] The present invention has successfully achieved this object: the inventors of the present invention have surprisingly found that a resin composition comprising a reactive diluent system based on an organic (meth)acrylate-based phosphorus compound can be effectively cured with a curable resin composition under mild conditions (i.e. via RT curing) using an accelerator system comprising a combination of at least one iron salt or complex with at least one salt or complex of cobalt or copper.

[0008] Generally, and by way of brief description, the main aspects of the present invention can be described as follows:

[0009] In a first aspect, the present invention provides a reactive diluent system for a composite resin comprising (a) a reactive diluent composition, and (b) an accelerator system, wherein

[0010] The reactive diluent composition (a) comprises or consists of an organic phosphorus compound of the general formula (I):

[0011]

[0012] wherein

[0013] R 1 = H, Me

[0014] R n , R m = O - , OH, Z, X 2 - P(=X 3 )R n+1 R m+1

[0015] n, m = 2-15

[0016] X 1 , X 2 = O, CH2, S, NH

[0017] X 3 = O, S

[0018]

[0019] and L is a hydrocarbon linker optionally comprising one or more heteroatoms;

[0020] and

[0021] The accelerator system (b) comprises or consists of:

[0022] (i) at least one iron salt or complex;

[0023] (ii) at least one transition metal salt or complex based on cobalt and copper; and

[0024] (iii) optionally at least one solvent.

[0025] In a second aspect, the present application relates to a curable resin composition comprising a curable resin and the above-mentioned reactive diluent system, and as a third aspect, the present application relates to the use of the reactive diluent system or the curable resin composition for the preparation of a composite resin having flame retardant properties or for the preparation of a composite resin having enhanced glass fiber adhesion.

[0026] In a fourth aspect, the present application provides a method for the preparation of a cured composite resin composition, the method comprising:

[0027] (a) providing a curable resin composition as described above,

[0028] (b) optionally adding at least one organic or inorganic additive, and

[0029] (c) initiating the curing process by adding an initiator.

[0030] In a fifth aspect, the present application relates to a fiber-reinforced material comprising:

[0031] (a) a polymeric resin selected from the group consisting of (meth)acrylate resins, unsaturated polyester

[0032] resins (UPR) or vinyl ester resins (VER); and

[0033] (b) at least one reinforcing fiber material,

[0034] The fiber-reinforced material can be obtained by curing the components (a) and (b) in the presence of an initiator using the reactive diluent system as described above. DETAILED DESCRIPTION

[0036] Hereinafter, elements of the present application will be described. These elements are presented with respect to particular embodiments; however, it should be understood that they can be combined in any manner and in any number to create additional embodiments. The various described embodiments and preferred embodiments should not be construed as limiting the present application to only the explicitly described embodiments. This description should be understood as supporting and encompassing all possible embodiments including those yet to be devised. Additionally, any permutations and combinations of all described elements are to be considered disclosed herein unless the context clearly dictates otherwise.

[0037] As used herein, the terms “of the present invention,” “according to the present invention,” “in accordance with the present invention,” and the like are intended to refer to all aspects and embodiments of the invention described and / or claimed herein.

[0038] As used herein, the term “comprising” is to be interpreted as encompassing both “including” and “consisting of,” both of which are expressly intended and are thus individually and separately disclosed embodiments according to the present invention. If used herein, “and / or” is to be taken as specific disclosure of each of the two specified features or components. For example, “A and / or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each was individually written out.

[0039] It will be understood that the teachings of the present application apply to specific problems or environments, and that variations or additional features are included within the scope of the present application, e.g. further aspects and embodiments, in accordance with the teachings contained herein, will be within the capabilities of persons skilled in the art.

[0040] The description and definitions of the above features are not limited to any particular aspect or embodiment of the present application, and apply equally to all aspects and embodiments described, unless the context dictates otherwise.

[0041] In the context of the present application, the term “(meth)acrylate” refers to an ester of methacrylic acid or an ester of acrylic acid.

[0042] As used herein, the term “reactive diluent” or “reactive solvent” refers to a solvent that is reactive during the curing step. They typically consist of ethylenically unsaturated monomeric compounds. In the context of the present application, a “reactive diluent composition” is a composition comprising or consisting of at least one reactive diluent. A “reactive diluent system” includes said reactive diluent composition and an accelerator system.

[0043] A coordination compound is a substance composed of one or more metal atoms or ions surrounded by a series of bound molecules or ions, which are called ligands or complexing agents. Coordination compounds centered on metal atoms / ions are called metal complexes. Coordination compounds can be ionic and exist as cationic or anionic species in combination with various corresponding counter ions.

[0044] All references, patents and publications cited herein are incorporated by reference in their entirety.

[0045] The present invention is based on the surprising discovery that a resin composition comprising a curable resin and a reactive diluent system based on an organic (meth)acrylate-based phosphorus compound can be effectively cured under mild conditions (i.e., via RT curing) using an accelerator system comprising at least one iron salt or complex in combination with at least one salt or complex selected from the group consisting of cobalt and copper.

[0046] Reactive diluent system

[0047] Reactive diluent composition (a)

[0048] The reactive diluent composition (a) comprises or consists of an organic phosphorus compound of the general formula (I):

[0049]

[0050] wherein

[0051] R 1 = H, Me

[0052] R n , R m = O - , OH, Z, X 2 - P(=X 3 )R n+1 R m+1

[0053] n, m = 2-15

[0054] X 1 , X 2 = O, CH2, S, NH

[0055] X 3 = O, S

[0056]

[0057] and L is a hydrocarbon linker optionally comprising one or more heteroatoms.

[0058] Thus, the linking group moiety links the phosphorus unit to the ethylenically unsaturated polymerizable monomer unit. As used in the context of the present application, the term "hydrocarbon linking group" includes linking groups that are straight chain and / or branched aliphatic (e.g., alkyl or alkenyl), cycloaliphatic (e.g., cycloalkyl, cycloalkenyl), and aromatic, with aromatic, aliphatic, cycloaliphatic, substituted aromatic substituents, and cyclic substituents where the ring is completed by another portion of the molecule (e.g., two substituents together form a ring).

[0059] The term "hydrocarbon linking group" includes linking groups having substituted hydrocarbon substituents that are substituents containing non-hydrocarbon groups (e.g., chloro, fluoro, bromo, iodo, hydroxy, alkoxy, mercapto, alkylmercapto, alkylhydroxy, nitro, amino, nitroso, sulfoxy) that do not alter the primary hydrocarbon character of the linking group.

[0060] The term "hydrocarbon linking group" also includes linking groups having hetero substituents that are substituents that, while having the primary hydrocarbon character, also contain atoms other than carbon in the ring or chain otherwise composed of carbon atoms. Included are ethyleneoxy (EO) and propyleneoxy (PO) linking groups. The hetero atoms include sulfur, oxygen, nitrogen, and encompass substituents such as pyridyl, furanyl, imidazolyl, and other heterocycles.

[0061] The hydrocarbon linking group can be a C0-C 70 hydrocarbon linking group.

[0062] The linking group can be, for example, X 1 (CH2CH2O) x -P (in this case, X 2 =O) where x = 1-20.

[0063] In one embodiment of the application, the organophosphorus compound of formula (I) is

[0064]

[0065] wherein

[0066] R 1 =H, Me,

[0067] R n , R m =O - , OH, Z, O-P(=O)R n+1 R m+1

[0068] n, m = 2-15

[0069] x = 1, 2, 3,..., 50

[0070]

[0071] x' = x, 1, 2, 3,..., 50

[0072] optionally in the presence of

[0073] H3PO4, H4P2O7, their salts as well as acyclic / cyclic (poly)phosphates and their salts, and (meth)acrylic acid methyl ester.

[0074] The polyphosphate moiety can contain mono-, di-, tri- or higher phosphates, or mono- and / or diphosphonates.

[0075] The reactive diluent composition can comprise a solvent, e.g. a reactive solvent.

[0076] The organic phosphorus compound of formula (I) present in the reactive diluent composition is preferably a 2-hydroxyalkyl (meth)acrylate phosphate ester, e.g. 2-hydroxyethyl methacrylate phosphate ester.

[0077] The reactive diluent composition can further comprise an organic solvent, e.g. an aliphatic hydrocarbon solvent or an aromatic hydrocarbon solvent, preferably a (meth)acrylate solvent.

[0078] Preferably, the reactive diluent composition contains 70 wt% of the phosphate ester component and 30 wt% of the reactive solvent.

[0079] In a particular embodiment of the present application, the reactive diluent composition is a solution of 2-hydroxyethyl methacrylate phosphate ester in methyl methacrylate (MMA). Preferably, the reactive diluent composition is a solution consisting of 70 wt% of 2-hydroxyethyl methacrylate phosphate ester in 30 wt% of MMA.

[0080] Often, the commercially available precursor molecules are mixtures, e.g. Sipomer PAM-4000 or PAM-100 or PAM-200 (from Solvay) or HEMA-P 70M / 100 (available from Evonik). Such mixtures are contemplated herein, as well as the pure precursor monomer units. HEMA (poly)phosphates (e.g. PAM-4000 available from Solvay) can be made directly from HEMA and P2O5 or (poly)phosphoric acid. Alternatively, other monomers can be used in place of HEMA, such as hydroxypropyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate. Other examples include polyethylene glycol (meth)acrylate (poly)phosphates (PAM-100 available from Solvay) and polypropylene glycol (meth)acrylate (poly)phosphates (PAM-200 available from Solvay).

[0081] Accelerator system (b)

[0082] The at least one iron salt or complex (i) present in the accelerator system (b) can be an iron (II) salt or complex, or an iron (III) salt or complex, or a mixture of iron (II) and iron (III) salts and complexes.

[0083] Advantageously, the iron salt or complex present in the accelerator system (b) is an iron (II) coordination compound. Preferably, the iron (II) coordination compound is selected from iron (II) species linked to mono- and polydentate N and / or O-donor ligands. Alternatively, the iron salt or complex present in the accelerator system (b) can also be selected from iron halides, carboxylates, 1,3-diketonates and cyclopentadienyl-based iron complexes.

[0084] Examples of suitable iron carboxylates are iron lactate, iron naphthenate, iron 2- ethylhexanoate (i.e. iron octoate), iron formate, iron acetate, iron propionate, iron butyrate, iron valerate, iron hexanoate, iron heptanoate, iron octanoate, iron nonanoate, iron decanoate, iron neodecanoate and iron dodecanoate, an example of an iron 1,3-diketonate is acetylacetonate iron, and iron complexes of acetylacetone, benzoylacetone, dibenzoylmethane and acetoacetic acid, such as diethylacetoacetamide, dimethylacetoacetamide, dipropylacetoacetamide, dibutylacetoacetamide, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate and butyl acetoacetate. An example of a cyclopentadienyl iron complex is a complex comprising iron and two substituted or unsubstituted cyclopentadienyl ligands, wherein the optional substituents on the cyclopentadienyl ring are selected from alkyl, aryl and alkenyl groups having from 1 to 12 carbon atoms, which can optionally be substituted with a heteroatom selected from O, N, S, Si and P. An example of a cyclopentadienyl iron complex is ferrocene.

[0085] In one embodiment of the present application, the at least one iron salt or complex (i) present in the accelerator system (b) is iron (1+), chloro[bis-methyl-9,9-dihydroxy-3-methyl-2,4-di(2-pyridyl- kappa N)-7-[(2-pyridyl-kappa N)methyl]-3,7-diazabicyclo[3.3.1]nonane-1,5- dicarboxylate-kappa N 3 , kappa N 7 ]-, chloride (1-) (CAS: 478945-46-9), wherein the oxidation state of iron is +II, as depicted in the following formula (II).

[0086]

[0087] Such Fe complexes are commercially available, for example as Nouryact CF40 (Nouryon) or BorchiOxy-Coat 1410 (Borchers GmbH). They are usually supplied as a solution in a solvent, for example 1,2-propanediol, or a reactive diluent, for example hydroxyethyl methacrylate.

[0088] The at least one transition metal salt or complex (ii) present in the accelerator system (b) can be a cobalt salt or complex, a copper salt or complex or a mixture of at least one cobalt salt or complex and at least one copper salt or complex.

[0089] Advantageously, the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is a cobalt (II) salt or complex. Suitable cobalt salts or complexes are, for example, halides, nitrates, sulfates, sulfonates, phosphates, phosphonates, oxides or carboxylates of cobalt. Suitable carboxylates are, for example, lactates, 2-ethylhexanoates, acetates, propionates, butyrates, oxalates, laurates, oleates, linoleates, palmitates, stearates, acetylacetonates, octoates, nonoates, heptanoates, neodecanates or naphthenates. The cobalt (II) salt or complex is preferably a cobalt alkylcarboxylate, for example cobalt (II) ethylhexanoate, cobalt (II) octoate or cobalt acetylacetonate or a cyclopentadienyl-based complex of cobalt. Particularly preferred are (2-ethylhexanoato)cobalt, (neodecanoato)cobalt or (naphthenato)cobalt.

[0090] Alternatively, the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is a salt or complex of copper (I) or copper (II). Suitable copper salts or complexes are, for example, halides (e.g. chlorides), nitrates, sulfates or alkylcarboxylates of copper. Suitable carboxylates are, for example, lactates, 2-ethylhexanoates, acetates, propionates, butyrates, oxalates, laurates, oleates, linoleates, palmitates, stearates, acetylacetonates, octanoates, nonanoates, heptanoates, neodecanates or naphthenates. The salt or complex of copper (I) or copper (II) is preferably an alkylcarboxylate. Particularly preferred is copper (2-ethylhexanoate).

[0091] The ratio of the at least one iron salt or complex (i) to the transition metal salt or complex (ii) can be in the range of 2:1 to 500:1, preferably between 10:1 and 300:1. Particularly preferred is a ratio of the at least one iron salt or complex (i) to the transition metal salt or complex (ii) of 10:1 to 200:1.

[0092] The ratio of the organic phosphorus compound in the reactive diluent composition (a) to the metal content in the accelerator system (b) can be in the range of 80:1 to 4000:1.

[0093] The accelerator composition can comprise at least one solvent. The solvent for the cobalt (or copper) compound and the iron compound can be the same or different and can be, for example, a hydroxyl functional solvent.

[0094] The term "hydroxyl functional solvent" includes compounds of formula (III)

[0095] HO-(CH2-C(R 1 )2-(CH2) m -O-) n -R 2 (III)

[0096] wherein each R 1 is independently selected from hydrogen, an alkyl group having 1 to 10 carbon atoms and a hydroxyalkyl group having 1 to 10 carbon atoms, n = 1 to 10, m = 0 or 1, and R 2 is hydrogen or an alkyl group having 1 to 10 carbon atoms. Most preferably, each R 1 is independently selected from H, CH3and CH2OH. Examples of suitable hydroxyl functional solvents are diols such as diethylene monobutyl ether, ethylene glycol, diethylene glycol, dipropylene glycol and polyethylene glycol, glycerol and pentaerythritol.

[0097] Furthermore, the accelerator solution according to the present application can further comprise additional organic compounds, such as aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents and solvents bearing aldehyde, ketone, ether, ester, alcohol, phosphate or carboxylic acid groups. Examples of suitable solvents are aliphatic hydrocarbon solvents, such as white spirit and odourless mineral spirit (OMS), aromatic hydrocarbon solvents, such as naphthene and mixtures of naphthene and paraffin, isobutanol; amyl alcohol; 1,2-dioximes, N-methylpyrrolidone, N-ethylpyrrolidone; dimethylformamide (DMF); dimethylsulfoxide (DMSO); 2,2,4-trimethylpentanediol diisobutyrate (TxIB); esters, such as dibutyl maleate, dibutyl succinate, ethyl acetate, butyl acetate, mono- and diesters of ketopentanoic acid, acetates of pyruvic acid and ascorbic acid, such as ascorbyl palmitate; aldehydes; mono- and diesters, more particularly diethyl malonate and succinate; 1,2-diketones, in particular diacetyl and glyoxal; benzyl alcohol, fatty alcohols and reactive diluents, such as styrene, styrene derivatives or (meth)acrylates.

[0098] The total amount of solvent present in the accelerator solution is preferably from 1 to 50 wt.%, preferably from 5 to 30 wt.%.

[0099] If the accelerator composition is an accelerator solution, the cobalt or copper can be present in an amount of at least 0.5 mmol / kg of the resin containing the reactive diluent, preferably at least 2 mmol / kg. The cobalt or copper is preferably present in the accelerator solution in an amount of less than 200 mmol / kg of the resin, preferably less than 50 mmol / kg of the resin, and more preferably less than 25 mmol / kg of the resin.

[0100] If the accelerator composition is an accelerator solution, the iron can be present in an amount of at least 0.0001 mmol / kg of the resin, more preferably at least 0.01 mmol / kg of the resin. The iron is preferably present in the accelerator solution in an amount of less than 20 mmol / kg of the resin, more preferably less than 10 mmol / kg of the resin, and most preferably less than 1 mmol / kg of the resin.

[0101] The total amount of transition metal to be used in the process and composition according to the present application is preferably from 0.5 to 100 mmol / kg of the resin containing the reactive diluent, more preferably from 1 to 50 mmol / kg, and most preferably from 1 to 10 mmol / kg of the resin.

[0102] The accelerator composition can optionally contain one or more accelerators, bases, water, inhibitors, additives and / or fillers.

[0103] There are three important classes of accelerators: ammonium, alkali or alkaline earth metal carboxylates, phosphorus-containing compounds, and 1,3-diketones. Examples of 1,3-diketones are acetylacetone, benzoylacetone and dibenzoylmethane, and acetoacetates such as diethylacetoacetamide, dimethylacetoacetamide, dipropylacetoacetamide, dibutylacetoacetamide, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate and butyl acetoacetate.

[0104] Examples of suitable ammonium, alkali and alkaline earth metal carboxylates are 2- ethylhexanoate (i.e. octoate), nonanoate, heptanoate, neodecanoate and naphthenate. The preferred alkali metal is potassium (K). The salts can be added as such to the accelerator composition or the resin, or they can be formed in situ. For example, the alkali metal 2- ethylhexanoate can be prepared in situ in the accelerator composition after adding alkali metal hydroxide and 2-ethylhexanoic acid to the solution.

[0105] Examples of suitable phosphorus-containing compounds are compounds of the formula P(R)3and P(R)3=0, wherein each R is independently selected from hydrogen, an alkyl group having 1 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. Preferably, at least two R-groups are selected from alkyl groups or alkoxy groups. Specific examples of suitable phosphorus-containing compounds are diethylphosphate, dibutylphosphate, tributylphosphate, triethylphosphate (TEP), dibutylphosphite and triethylphosphate.

[0106] Acetoacetates are particularly preferred accelerators. Particularly preferred is diethylacetoacetamide. Even more preferred is a combination of diethylacetoacetamide and potassium 2- ethylhexanoate.

[0107] If one or more accelerators are present in the accelerator composition, their amount is preferably at least 0.01 wt.-%, more preferably at least 0.1 wt.-%, even more preferably at least 1 wt.-%, more preferably at least 10 wt.-%, and most preferably at least 20 wt.-%; preferably not more than 90 wt.-%, more preferably not more than 80 wt.-%, and most preferably not more than 70 wt.-%, all based on the total weight of the accelerator composition.

[0108] Suitable nitrogen-containing bases present in the accelerator composition and pre-accelerated resin are primary, secondary and tertiary amines such as triethylamine, dimethyl aniline, diethyl aniline or N,N-dimethyl-p-toluidine (DMPT), polyamines such as 1,2-(dimethylamine)ethane, secondary amines such as diethylamine, ethoxylated amines such as triethanolamine, dimethylaminoethanol, diethanolamine or monoethanolamine, and aromatic amines such as pyridine or bipyridine. The amount of the nitrogen-containing base present in the accelerator composition is preferably 5 to 50 wt.-%.

[0109] To prevent the occurrence of undesired polymerization, a polymerization inhibitor (stabilizer) can be used in the accelerator composition according to the present application. In the context of the present application, the terms "(polymerization) inhibitor" and "stabilizer" are used synonymously. Advantageously, the polymerization inhibitor is selected from the group consisting of hydroquinone, hydroquinone ethers, such as hydroquinone monomethyl ether or di-tert-butyl-hydroquinone, phenothiazine, N,N'-(diphenyl)-p-phenylenediamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, p-phenylenediamine, methylene blue or sterically hindered phenols, wherein the amount of stabilizer is between 0 and 1000 ppm. The amount of stabilizer is preferably between 5 and 500 ppm, and most preferably between 20 and 300 ppm. Preferably, the polymerization inhibitor is selected from the group consisting of hydroquinone monomethyl ether, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methyl-phenol, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid octadecyl ester (e.g. Irganox 1076) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and mixtures thereof.

[0110] In a particularly preferred embodiment of the present application, the reactive diluent composition (a) comprises or consists of 2-hydroxyethyl methacrylate phosphate ester and the accelerator system (b) comprises iron (1+), chloro[bisdimethyl-9,9-dihydroxy-3-methyl-2,4-di(2-pyridyl-KN)-7-[(2-pyridyl-KN)methyl]-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarboxylate-KN 3 ,KN 7 ] - , chloride (1-) (CAS: 478945-46-9) and Co(II) 2-ethylhexanoate.

[0111] In an alternative embodiment, the reactive diluent composition (a) comprises or consists of 2-hydroxyethyl methacrylate phosphate ester and the accelerator system (b) comprises iron (1+), chloro[bisdimethyl-9,9-dihydroxy-3-methyl-2,4-di(2-pyridyl-KN)-7-[(2-pyridyl-KN)methyl]-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarboxylate-KN 3 ,KN 7 ] - , chloride (1-) (CAS: 478945-46-9) and Cu(II) 2-ethylhexanoate.

[0112] The reactive diluent system according to the present application is particularly suitable for the preparation of composite resins having flame retardant properties and / or for the preparation of composite resins having enhanced glass fiber adhesion.

[0113] Curable resin composition

[0114] The present application further relates to a curable resin composition comprising a curable resin and the reactive diluent system as described above in various embodiments.

[0115] In a particularly preferred embodiment of the present application, the organophosphorous compound of general formula (I) is 2-hydroxyethyl methacrylate phosphate.

[0116] Resins suitable for curing using the reactive diluent system according to the present application include alkyd resins, unsaturated polyester (UP) resins, vinyl ester (VE) resins, (meth)acrylate resins, polyurethanes, epoxy resins and mixtures thereof.

[0117] Preferred resins are (meth)acrylate resins, UP resins and vinyl ester resins. In the context of the present application, the terms "unsaturated polyester resin" and "UP resin" refer to a combination of an unsaturated polyester resin and an olefinically unsaturated monomer compound. The term "(meth)acrylate resin" refers to a combination of an acrylate or methacrylate resin and an olefinically unsaturated monomer compound. UP resins and acrylate resins as defined above are well known and commercially available.

[0118] Curing is typically initiated by adding an accelerator solution according to the present application and an initiator (peroxide) to the resin or by adding the initiator (peroxide) to a pre-accelerated resin.

[0119] UP resins suitable for curing by the method of the present application are so-called ortho-resins, iso-resins, iso-NPG resins and dicyclopentadiene (DCPD) resins. Examples of such resins are ortho-phthalic, iso-phthalic, maleic, fumaric, allyl, vinyl and epoxy type resins, bisphenol A resins, terephthalic resins and mixed resins.

[0120] Vinyl ester resins have unsaturation sites only in terminal positions, which are introduced via reaction of an epoxy resin with (meth)acrylic acid or are hydroxyethylated with (meth)acrylic acid. Typical examples of epoxy resins include bisphenol-A, novolak, tetraphenyl ethane, cycloaliphatic, tetra-bromo bisphenol-A and the like. Thus, vinyl ester resins are (meth)acrylate functional resins. Another class of vinyl ester resins are vinyl ester polyurethane resins, which are also known as polyurethane methacrylate resins.

[0121] The acrylic resin included in the resin composition can be selected from thermosetting acrylic resins or acrylic modified resins well known in the art. Acrylic resins include acrylates, methacrylates, diacrylates and dimethacrylates, and oligomers thereof. The oligomeric acrylates can be acrylated polyurethanes, epoxide polyesters polyethers and acrylics. Furthermore, the acrylic resins can use a slurry of pre-reacted polymers in monomers made by polymerizing acrylic monomers to a specific degree of polymerization or copolymerizing mixtures of different acrylic monomers to a specific degree of polymerization. Acrylic modified resins are a large class of resins similar to oligomeric acrylates except that acrylic modified resins use a base resin with a molecular weight sufficient that it cannot be considered an oligomer. Methods of making acrylic modified resins are well known to those skilled in the art. Thus, acrylic modified resins can contain solvents. The solvents can be inert to the resin system or they can be reactive with it during the curing step. Particularly preferred are reactive solvents or so-called reactive diluents. They are usually composed of ethylenically unsaturated monomeric compounds. Examples of ethylenically unsaturated monomeric compounds include styrene and styrene derivatives such as alpha-methyl styrene, vinyl toluene, indene, divinyl benzene, vinyl pyrrolidone, vinyl siloxane, vinyl caprolactam, stilbene, and diallyl phthalate, benzylidene acetone, allyl benzene, methyl methacrylate, methyl acrylate, (meth)acrylic acid, diacrylates, dimethacrylates, acrylamide; vinyl acetate, triallyl cyanurate, triallyl isocyanurate, allyl compounds for optical applications (e.g. (di)glycol diallyl carbonate), chlorostyrene, t-butyl styrene, t-butyl acrylate, butanediol dimethacrylate and mixtures thereof. Suitable examples of (meth)acrylated reactive diluents are PEG 200 di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 2,3-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate and its isomers, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, PPG 250 di(meth)acrylate, tricyclodecane dimethylol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycidyl (meth)acrylate, (bis)maleimide, (bis)citraconimide, (bis)itaconimide and mixtures thereof.

[0122] The amount of ethylenically unsaturated monomer in the pre-accelerated resin is preferably at least 0.1 wt%, more preferably at least 1 wt%, and most preferably at least 5 wt%, based on the weight of the resin. The amount of ethylenically unsaturated monomer is preferably no more than 50 wt%, more preferably no more than 40 wt%, and most preferably no more than 35 wt%.

[0123] Further, the present application also provides a two-component composition comprising (a) as a first component the curable resin composition as described above, and (b) as a second component an initiator, such as a peroxide.

[0124] Peroxides suitable for curing the resin and suitable for being present in the second component of the two-component composition include inorganic peroxides and organic peroxides, such as the commonly used ketone peroxides, peroxyesters, di-aryl peroxides, di-alkyl peroxides and peroxydicarbonates, as well as peroxy carbonates, peroxy ketals, hydroperoxides, diacyl peroxides and hydrogen peroxide. Preferred peroxides are organic hydroperoxides, ketone peroxides, peroxyesters and peroxy carbonates. Even more preferred are hydroperoxides and ketone peroxides. Preferred hydroperoxides include cumyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butyl hydroperoxide, isopropyl cumyl hydroperoxide, t-amyl hydroperoxide, 2,5-dimethylhexyl-2,5-dihydroperoxide, pinane hydroperoxide, p alkyl hydroperoxide, terpene hydroperoxide and pinene hydroperoxide. Preferred ketone peroxides include methyl ethyl ketone peroxide, methyl isopropyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide and acetyl propyl ketone peroxide. Mixtures of two or more peroxides can also be used; for example, a hydroperoxide or ketone peroxide in combination with a peroxyester.

[0125] A particularly preferred peroxide is methyl ethyl ketone peroxide. Those skilled in the art will appreciate that these peroxides can be combined with conventional additives, such as fillers, pigments and de-sensitizers. Examples of de-sensitizers are hydrophilic esters and hydrocarbon solvents. The amount of peroxide to be used for curing the resin is preferably at least 0.1 parts per hundred parts of resin (phr), more preferably at least 0.5 phr, and most preferably at least 1 phr. The amount of peroxide is preferably no more than 8 phr, more preferably no more than 5 phr, and most preferably no more than 2 phr.

[0126] The above-described reactive diluent system in various embodiments and / or the above-described curable resin composition in various embodiments can be used to make a composite resin having flame retardant properties and / or to make a composite resin having enhanced glass fiber adhesion.

[0127] Method of making a cured, composite resin composition

[0128] In another aspect, the present application relates to a method for preparing a cured composite resin composition, the method comprising:

[0129] (a) providing a curable resin composition as described above,

[0130] (b) optionally, adding at least one organic or inorganic additive, and

[0131] (c) initiating the curing process by adding an initiator.

[0132] The curing process can be carried out at any temperature from -15 °C up to 250 °C, depending on the initiator system, accelerator system, compounds to adapt the curing rate, and the resin composition to be cured. Preferably, it is carried out at ambient temperature in the context of applications such as hand lay-up, spray-up, filament winding, resin transfer molding, coating (e.g. gel coat and standard coating), button production, centrifugal casting, corrugated or flat sheet, relining systems, kitchen sinks made via pouring compounds, etc. However, it can also be used in sheet molding compound (SMC), bulk molding compound (BMC), pultrusion technology, etc., using temperatures up to 180 °C, more preferably up to 150 °C, most preferably up to 100 °C.

[0133] Other optional additives can be used in the curing process, such as fillers, fibers, pigments, dispersants, inhibitors, auxiliaries and accelerators. Examples of fibers are glass fibers, carbon fibers, aramid fibers, polyamide fibers, boron fibers, ceramic fibers, metal fibers, carbon fibers and natural fibers (e.g. jute, kenaf, industrial hemp, flax (linen), ramie, etc.) or any combination thereof. The fiber content depends on the fiber type, the used preparation method and the final field of application. For example, in SMC formulations, the glass fiber content is preferably up to 35 wt.-%, e.g. in combination with a high filler content of up to 40 wt.-%. The resin content in SMC applications is preferably between 10 and 20 wt.-%. BMC formulations contain a higher filler content of preferably 60 wt.-%, and a lower fiber content of preferably 15 wt.-%. In hand lay-up processes, a fiber content of up to 60 wt.-% is preferred. In spray-up applications, a moderate glass fiber content of 30-35 wt.-% is preferred, mainly using chopped glass fibers. In filament winding and pultrusion, glass roving is used in a range of 30-80 wt.-%.

[0134] The initiator can be as defined above. Advantageously, the initiator is an organic peroxide, which is preferably selected from the group consisting of methyl ethyl ketone peroxide (MEKP), benzoyl peroxide (BPO), cumene hydroperoxide (CuHP) or any combination thereof.

[0135] Cured, fiber-reinforced, composite resin composition

[0136] Generally, fiber-reinforced resins (fiber-reinforced plastics - FRP) have the advantages of relatively high strength, good product surface state, high corrosion resistance, and high chemical resistance. With these advantages, they are mainly used as parts of housing materials, industrial materials, tanks, containers, ships, automobiles, trains, and the like. Fiber-reinforced resins include a synthetic resin as a binder and a reinforcing fiber added thereto, and are cured. If the adhesion between the reinforcing fiber and the resin is insufficient, their mechanical strength (including rigidity and flexibility) will often be deteriorated.

[0137] According to the above findings, the present application also provides a fiber-reinforced material comprising:

[0138] (a) a polymeric resin selected from a (meth)acrylate resin, an unsaturated polyester resin (UPR) or a vinyl ester resin (VER); and

[0139] (b) at least one reinforcing fiber material, preferably glass fibers;

[0140] The fiber-reinforced material can be obtained by curing the components (a) and (b) in the presence of an initiator using the reactive diluent system according to the present application.

[0141] The initiator as well as the curing conditions can be as described hereinabove.

[0142] The reinforcing fibers for use in the fiber-reinforced material can be as defined hereinabove. Any common fiber that can be used for reinforcing resins can be used in the fiber-reinforced material according to the present application. In particular, they can include, for example, glass fibers, carbon fibers, aramid fibers, polyamide fibers, boron fibers, ceramic fibers (e.g., silicon carbide fibers, alumina fibers), metal fibers, or natural fibers. These reinforcing fibers can have any form of yarn, roving, strand, chopped strand, scrim, roving scrim, and the like.

[0143] The fiber-reinforced resin composition can further comprise at least one filler. Such a filler can be selected from ATH (aluminum trihydroxide) or antimony oxides for flame retardation, calcium carbonate, and / or kaolin. Alternatively, or in addition thereto, the fiber-reinforced resin can further comprise at least one additional additive selected from inhibitors, retarders, thixotropic agents (e.g., fumed silica) and / or UV absorbers, or mixtures thereof. DETAILED DESCRIPTION

[0144] In the following, the present application is illustrated by non-limiting examples and exemplary embodiments.

[0145] Examples

[0146] Table 1 : Components used

[0147]

[0148] Method

[0149] Determination of bulk polymerization and polymerization time

[0150] For the bulk polymerization, the UPR was mixed with the reactive diluent and / or the phosphate compound according to Table 2 and Table 3. The accelerator or accelerator mixture was added and the mixture was homogenized by stirring for 1 minute, after which the initiator solution was added. The mixture was stirred for another 1 minute and then transferred to a standard test tube (18 x 180 mm) to monitor the polymerization time. The temperature profile of the reaction was recorded by means of a temperature sensor. This temperature sensor was located in a second, smaller tube with tetraethylene glycol as transfer fluid, which was fixed in the middle of the test tube so that it was immersed in the sample liquid low enough to be able to measure the sample temperature accurately. The start of the measurement was taken as the time at which the redox components were combined. The position of the maximum reaction temperature T 最大 corresponds to the polymerization time.

[0151] DSC measurement (determination of glass transition temperature)

[0152] Before determining the glass transition temperature, all samples were post-cured at 80 °C for 8 hours. For the determination of the glass transition temperature, the commonly used analytical method, differential scanning calorimetry (DSC) was used (see Ehrenstein, Gottfried W. Riedel, Gabriela, Trawiel, Pia (2004); Thermal Analysis of Plastics - Theory and Practice, Hanser Publishers). The samples prepared by bulk polymerization were analyzed in aluminum crucibles with perforated lid (Mettler Toledo DSC instrument with liquid nitrogen cooling) under nitrogen in the temperature range from -50 °C to 150 °C at a heating rate of 10 K / min (after rapid cooling).

[0153] Mechanical testing

[0154] Tensile testing was performed according to ISO 527-2. Dog bone samples were cast using 200 g resin formulations. All samples were post-cured in an oven at 80 °C for 24 hours prior to the tensile testing.

[0155] Water uptake

[0156] The casting sample materials of Example AC and Reference 1 were immersed in demineralized water for three weeks. After 7 days and 21 days, the samples were weighed and the weight increase was recorded.

[0157] Table 2: UPR 1+ HEMA-P 70M uses a cobalt-based curing system under standard curing conditions.

[0158]

[0159] Results:

[0160] As can be clearly seen from the polymerization time measurements shown in Table 2, in the presence of phosphorus compounds (such as...) In the case of HEMA-P 70M, it is not possible to cure UPR using a cobalt-based curing system under standard conditions.

[0161] Table 3: Standard Resin 1+ HEMA-P 70M New Curing System

[0162]

[0163] *Unavailable Results:

[0164] Examples 3 through 8 demonstrate that curing can be achieved with varying concentrations of reactive diluents and different Fe-based accelerators.

[0165] Examples 3 to 8 demonstrate that, when using the described accelerator system based on cobalt and iron, it is possible to produce accelerators containing 20% ​​by weight of... HEMA-P 70M resin curing. A comparison of Examples 3 and 7 also shows that the Fe metal content can be significantly reduced depending on the form of supply of the accelerator. Nouryact CF40 was supplied at a concentration of 0.8 to 0.9 mg / kg in hydroxyethyl methacrylate as a reactive diluent. The reactive diluent increases the reactivity and solubility of the accelerator in the resin mixture.

[0166] UPR 2– HEMA-P 70M Novel Catalyst System and Mechanical Testing

[0167] Table 4: General Formulations

[0168]

[0169] Examples 9 to 11 and Reference 3 were cured according to the formulations given in Tables 4 and 5. The accelerator solution was mixed before adding to the resin. The initiator was added to the accelerated resin. All resins cured at room temperature in 2.5 to 3.5 hours when cast in 50 grams of resin formulation in a layer thickness of 2 cm.

[0170] Table 5: UPR resin 2 and Detailed formulation of HEMA-P and test results

[0171]

[0172] * The sample was very brittle and only 4 measurements were possible instead of 6

[0173] Examples 9 to 11 cured well and the mechanical data were in good agreement with the styrene based reference samples. The mechanical properties of Examples 9 and 10 were comparable to the pure styrene based reference systems. Due to its hydrophilic nature the water uptake increased with increasing amount of HEMA-P.

[0174] Figure 1 It is shown that using a standard cobalt based curing system, UPR 1 polymerizes in the presence of Comparison of the measured polymerization time of HEMA-P70M with the styrene based reference samples.

Claims

1. A reactive diluent system for a composite resin comprising (a) a reactive diluent composition and (b) an accelerator system, wherein the reactive diluent composition (a) comprises or consists of an organophosphorus compound of the general formula (I): wherein n, m = 2 - 15 and L is a hydrocarbon linker optionally comprising one or more heteroatoms; and the accelerator system (b) comprises or consists of: (i) at least one iron salt or complex; (ii) at least one transition metal salt or complex selected from cobalt and copper; and (iii) optionally at least one solvent.

2. The reactive diluent system according to claim 1, wherein the organophosphorus compound of formula (I) is wherein n, m = 2 - 15 x' = x, 1, 2, 3..., 50 optionally in the presence of: H3PO4, H4P2O7, their salts as well as acyclic / cyclic (poly)phosphates and their salts, and methyl(meth)acrylate, wherein the (poly)phosphate moiety can contain mono, di, tri or higher phosphates, or mono and / or diphosphonates.

3. The reactive diluent system according to claim 1 or 2, wherein the organophosphorus compound of formula (I) present in the reactive diluent composition (a) comprises a 2-hydroxyalkyl(meth)acrylate phosphate, optionally in the presence of: H3PO4, H4P2O7, their salts as well as acyclic / cyclic (poly)phosphates and their salts, and methyl(meth)acrylate, wherein the (poly)phosphate moiety can contain mono, di, tri or higher phosphates, or mono and / or diphosphonates. R 1 = H, Me R n , R m = OH, Z, X 2 -P(=X 3 )R n+1 R m+1 4. The reactive diluent system according to claim 1 or 2, wherein the organophosphorus compound of formula (I) present in the reactive diluent composition (a) comprises 2-hydroxyethyl methacrylate phosphate, optionally in the presence of: H3PO4, H4P2O7, their salts as well as acyclic / cyclic (poly)phosphates and their salts, and methyl(meth)acrylate, wherein the (poly)phosphate moiety can contain mono, di, tri or higher phosphates, or mono and / or diphosphonates. X 1 , X 2 = O, CH2, S, NH X 3 = O, S 5. The reactive diluent system according to claim 1 or 2, wherein the at least one iron salt or complex (i) present in the accelerator system (b) is selected from iron (II) species associated with monodentate and polydentate N and / or O-donor ligands; or, wherein the at least one iron salt or complex (i) present in the accelerator system (b) is selected from iron halides, carboxylates, 1,3-dioxo complexes and cyclopentadienyl-based iron complexes.

6. The reactive diluent system according to claim 1 or 2, wherein the at least one iron salt or complex (i) present in the accelerator system (b) is an iron complex comprising tridentate or tetradentate or pentadentate or hexadentate nitrogen / oxygen donor ligands. ​ ​ ​ ​ ​ ​ R 1 = H, Me, R n , R m = OH, Z, O-P(=O)R n+1 R m+1 ​ x = 1，2，3…，50 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The reactive diluent system according to claim 1 or 2, wherein the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is a cobalt (II) salt or complex.

8. The reactive diluent system according to claim 1 or 2, wherein the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is an alkyl carboxylate salt of cobalt (II).

9. The reactive diluent system according to claim 1 or 2, wherein the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is a copper (I) or copper (II) salt or complex.

10. The reactive diluent system according to claim 1 or 2, wherein the at least one transition metal salt or complex (ii) selected from cobalt and copper present in the accelerator system (b) is an alkyl carboxylate salt of copper (I) or copper (II).

11. The reactive diluent system according to claim 1 or 2, wherein the ratio of the at least one iron salt or complex (i) to the transition metal salt or complex (ii) is in the range of 2:1 to 100:

1.

12. The reactive diluent system according to claim 1 or 2, wherein the ratio of the at least one iron salt or complex (i) to the transition metal salt or complex (ii) is between 10:1 to 20:

1.

13. The reactive diluent system according to claim 1 or 2, wherein the ratio of the organic phosphorous compound in the reactive diluent composition (a) to the metal content in the accelerator system (b) is in the range of 90:1 to 3000:

1.

14. A curable resin composition comprising a curable resin; and the reactive diluent system according to any one of the preceding claims 1 to 13.

15. Use of the reactive diluent system according to any one of claims 1 to 13 or the curable resin composition according to claim 14 for the preparation of a composite resin having flame retardant properties and / or for the preparation of a composite resin having enhanced glass fiber adhesion.

16. A method of preparing a cured composite resin composition, the method comprising: (a) providing a curable resin composition according to claim 14, (b) optionally, adding at least one organic or inorganic additive, and (c) initiating the curing process by adding an initiator.

17. The method according to claim 16, wherein the at least one organic or inorganic additive is a pigment, a dispersing agent and / or a fibrous material.

18. The method according to claim 16, wherein the fibrous material is selected from glass fibers, carbon fibers, aramid fibers, polyamide fibers, boron fibers, ceramic fibers, metal fibers and natural fibers or any combination thereof.

19. The method according to claim 16 or 17, wherein the initiator is an organic peroxide selected from methyl ethyl ketone peroxide (MEKP), benzoyl peroxide (BPO), cumene hydroperoxide (CuHP) or any combination thereof.

20. A fiber reinforced material comprising: (a) a polymeric resin selected from a (meth)acrylate resin, an unsaturated polyester resin (UPR) or a vinyl ester resin (VER); and (b) at least one reinforcing fiber material, said fiber reinforced material being obtained by curing the components (a) and (b) in the presence of an initiator using the reactive diluent system according to any one of claims 1 to 13.

21. The fiber reinforced resin composition according to claim 20, wherein the resin composition further comprises at least one filler selected from aluminum trihydroxide (ATH), oxides of antimony, calcium carbonate, kaolin or mixtures thereof, and / or wherein the resin composition further comprises at least one additive selected from an inhibitor, a retarder, a thixotropic agent or a UV absorber, or mixtures thereof.

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