WO2013083632A1

WO2013083632A1 - Multi-component system

Info

Publication number: WO2013083632A1
Application number: PCT/EP2012/074511
Authority: WO
Inventors: Johan Franz Gradus Antonius Jansen; Guido Joseph Elisabeth Hensen
Original assignee: Dsm Ip Assets B.V.
Priority date: 2011-12-06
Filing date: 2012-12-05
Publication date: 2013-06-13

Abstract

This invention relates to a multi-component system comprising a first component, a second component and a third component wherein the first component being a resin composition comprising an hydroxy-functional unsaturated polyester resin with an acid value < 10 and/or an hydroxy-functional vinyl ester resin with an acid value < 10, reactive diluent and a ligand according to the following formula (1) wherein each R₁, R₂, R₃ and R₄ are independently selected from hydrogen, C1-C12 alkyl, C3-C8 cycloalkyl, C6-C12 aryl and C5-C12 heteroaryl; X is selected from C=O and -[C(R)₂]_z- wherein z is from 1 to 3 and each R is independently selected from hydrogen, hydroxyl, C1 -C4 alkoxy and C1 -C4 alkyl; each Rx and Ry are independently selected from hydrogen, C1 -C8 alkyl, C1-C8-alkyl-O-C1-C8-alkyl, C1-C8-alkyl-O-C6-C10-aryl, C6-C10-aryl, C1 -C8-hydroxyalkyl, and (CH₂)nC(O)OR₅ wherein n is from 0 to 4 and R₅ is hydrogen, C1-C12 alkyl or an amide; Ra is a 2-pyridyl group or an alkylidene-2-pyridyl group; Rb is selected from C1-C24 alkyl, C6-C10 aryl and a group containing a heteroatom; and wherein the resin composition comprises an iron salt and/or complex; and the second component comprises an isocyanate compound with an average functionality > 1.7, and the third component comprises a peroxide compound.

Description

MULTI-COMPONENT SYSTEM

The invention relates to a multi-component system comprising as first component a room temperature radically curable, thermosetting resin composition comprising an hydroxyfunctional unsaturated polyester resin with an acid value < 10 and/or an hydroxyfunctional vinyl ester resin with an acid value < 10 and a reactive diluent, as second component an isocyanate and as third component a peroxide.

In such a multi component system curing is performed via two ways, a peroxide initiated free radical (co-)polymerization and an hydroxyl isocyanate polyaddition reaction.

The most widely used initiation method for the peroxide initiated free radical (co-) polymerization in unsaturated polyester resins or vinyl ester resins is performed via the transition metal catalyzed peroxide decomposition which allows the curing of these materials at room temperature. Examples of such transition metal catalyzed peroxide decomposition for curing unsaturated polyester resins or vinyl ester resins can for example be found in WO200800349, WO2008003498, WO2008003494, WO200800396, WO2008003498 and WO2008003500. A serious drawback of using these transition metals for the peroxide decomposition is the fact that besides accelerating the decomposition of the peroxides they also accelerate the hydroxyl isocyanate polyaddition. Although the free radical polymerization can be inhibited with inhibitors, in order to obtain a sufficiently long pot life -needed for instance for a vacuum infusion- these inhibitors have almost no effect on the hydroxyl isocyanate reaction. As a result of this, the pot life is significantly reduced when these catalysts are used and in some cases even to the point at which it becomes impossible to prepare larger objects via vacuum infusion.

As a consequence there is still a need for a transition metal catalyst for the decomposition of peroxides which accelerates the peroxide decomposition at room temperatures and less or even without affecting the hydroxyl isocyanate reaction, thereby obtaining a sufficiently long pot-life. As used herein, pot life means the time period between adding the peroxide and the isocyanate and obtaining a viscosity of the mixture which is that high that processing of the mixture is difficult or even impossible.

The inventors now have surprisingly found that a sufficiently long pot life can be achieved with a multi-component system comprising a first component, a second component and a third component , wherein the first component being a room temperature radically curable, thermosetting resin composition comprising an hydroxyfunctional unsaturated polyester resin with an acid value < 10 and/or an hydroxyfunctional vinyl ester resin with an acid value < 10, reactive diluent and a ligand according to the following formula (1 )

wherein each R-i , R₂, R3 and R₄ are independently selected from hydrogen, C1 -C12 alkyl, C3-C8 cycloalkyl, C6-C12 aryl and C5-C12 heteroaryl;

X is selected from C=0 and -[C(R)₂]_Z- wherein z is from 1 to 3 and each R is

independently selected from hydrogen, hydroxyl, C1 -C4 alkoxy and C1 -C4 alkyl;

each Rx and Ry are independently selected from hydrogen, C1 -C8 alkyl, (C1 -C8)alkyl- 0-(C1 -C8)alkyl, (C1 -C8)alkyl-0-(C6-C10)aryl, C6-C10 aryl, C1 -C8 hydroxyalkyl, and (CH₂)nC(0)OR₅ wherein n is from 0 to 4 and R₅ is hydrogen, C1 -C12 alkyl or an amide; Ra is a 2-pyridyl group or an alkylidene-2-pyridyl group;

Rb is selected from C1 -C24 alkyl, C6-C10 aryl and a group containing a heteroatom; and wherein the resin composition comprises an iron salt and/or complex;

and the second component comprises an isocyanate compound with an average functionality > 1.7,

and the third component comprises a peroxide compound.

Thermosetting resin compositions harden by chemical reaction, often generating heat when they are formed, and cannot be melted or readily re-formed once hardened. The resin compositions are liquids at normal temperatures and pressures, so can be used to impregnate reinforcements, for instance fibrous reinforcements, especially glass fibers, and/or fillers may be present in the resin composition, but, when treated with suitable radical forming initiators, the various unsaturated components of the resin composition crosslink with each other via a free radical copolymerization mechanism to produce a hard, thermoset plastic mass (also referred to as structural part). Preferably, the resin composition comprises an iron²⁺ salt or complex or iron³⁺salt or complex. Non-limiting examples of suitable iron salt and complexes are iron carboxylates such iron ethyl hexanoate and iron naphthenate; iron acetoacetates; iron acetyl acetonates: iron halides such as iron chloride . It will be clear that, instead of a single iron salt or complex also a mixture of iron salts and complexes can be used.

In a preferred embodiment according to the present invention, the resin composition comprises an iron complex with the ligand according to formula (1 ). In one embodiment, such iron complex is formed in situ by adding, to a resin composition comprising an unsaturated polyester resin and/or a vinyl ester resin and a reactive diluent, the ligand according to formula (1 ) and an iron salt or an iron complex (with a ligand not according to formula (1 )). In another and more preferred

embodiment, an iron complex with the ligand according to formula (1 ) (a preformed complex of iron and ligand according to formula (1 )) is added to a resin composition comprising an unsaturated polyester resin and/or a vinyl ester resin and a reactive diluent. In this embodiment of the invention, the iron in the complex is preferably present as an iron²⁺ or iron³⁺ salt. Although in view of solubility organic iron salts are preferred, in view of ease of formation simple iron halides are preferred especially iron chlorides.

The ligands according to formula (1 ) and iron complexes thereof can be prepared according to methods known in the art, as for example described in WO02/48301 .

Preferably, the ligand is present in the resin composition in an amount of at least 0.2 μηηοΙ per kilogram of primary resin system, more preferably in an amount of at least 0.5 μηηοΙ, even more preferably in an amount of at least 1 μηηοΙ, even more preferably in an amount of at least 5 μηηοΙ and even more preferably in an amount of at least 10 μηηοΙ. Preferably, the ligand is present in the resin composition in an amount of at most 4000 μηηοΙ per kilogram of primary resin system, more preferably in an amount of at most 3000 μηηοΙ, even more preferably in an amount of at most 2000 μηηοΙ, even more preferably in an amount of at most 1000 μηηοΙ and even more preferably in an amount of at most 500 μηηοΙ. In a preferred embodiment, the amount of ligand according to formula (1 ) in the resin composition is from 1 to 2000 μηηοΙ per kilogram of primary resin system.

Preferably, the iron salt or complex is present in the resin composition in such an amount that the amount of iron in the resin composition is at least 0.2 μηηοΙ per kilogram of primary resin system, more preferably at least 0.5 μηηοΙ, even more preferably at least 1 μηηοΙ, even more preferably at least 5 μηηοΙ and even more preferably at least 10 μηηοΙ. Preferably, the iron salt or complex is present in the resin composition in such an amount that the amount of iron in the resin composition is at most 4000 μηηοΙ per kilogram of primary resin system, more preferably at most 3000 μηηοΙ, even more preferably at most 2000 μηηοΙ, even more preferably at most 1000 μηηοΙ and even more preferably at most 500 μηηοΙ. In a preferred embodiment, the amount of iron in the resin composition is from 1 to 2000 μηηοΙ per kilogram of primary resin system.

Preferably, the molar ratio of iron to ligand according to formula (1 ) is from 0.02 to 20, more preferably from 0.02 to 10, even more preferably from 0.2 to 5, even more preferably from 0.5 to 2 and even more preferably from 1 to 2 and even more preferably iron and ligand according to formula (1 ) are present in an equimolar amount.

As used herein, the term primary resin system means the

combination of the unsaturated polyester resin(s), the vinyl ester resin(s) and the reactive diluent(s).

Preferably, Ri and/or R₂ is hydrogen. In a preferred embodiment, R-i and R₂ are hydrogen.

Preferably, R₃ and/or R₄ is a 2-pyridyl group. More preferably both R3 and R4 are a 2-pyridyl group.

Preferably, X is selected from C=0 and CH₂. More preferably, X is

C=0.

Preferably, each Rx and Ry are independently selected from C6-C10- aryl and (CH₂)_nC(0)0 R₅ wherein n is from 0 to 4 and R₅ is hydrogen, C1 -C12 alkyl or an amide. More preferably, each Rx and Ry are independently selected from C6 aryl and C(0)OR₅ wherein R₅ is C1 -C4 alkyl. Even more preferably, each Rx and Ry are independently selected from C(0)OR₅ wherein R₅ is C1 -C4 alkyl. In a preferred embodiment, Rx and Ry are the same. Preferably, Rx and Ry are C(0)OCH₃ (i.e. R₅.is methyl).

Preferably, Ra is an alkylidene-2-pyridyl group and more preferably

Ra is methylene-2-pyridyl.

Preferably, Rb is C1 -C12 alkyl, more preferably Rb is methyl or octyl and even more preferably, Rb is methyl.

The composition according to the invention preferably comprises hydroxyl-functional unsaturated polyester resin with acid value < 10 and hydroxyl- functional vinyl ester resin with acid value < 10 in such amount that the summed amount of hydroxyl-functional unsaturated polyester resins with acid value < 10 and hydroxyl-functional vinyl ester resins with acid value < 10 is from 30 to 85 wt.%

(relative to the total amount of hydroxyl-functional unsaturated polyester resins with acid value < 10, hydroxyl-functional vinyl ester resins with an acid value < 10 and reactive diluent). The hydroxyl-functional unsaturated polyester resin with acid value < 10 and hydroxyl-functional vinyl ester resin with an acid value < 10 as is comprised in the resin compositions according to the present invention, may suitably be selected from the unsaturated polyester resins or vinyl ester resin as are known to the skilled man. Unsaturated polyester and vinyl ester resins are characterised by having carbon- carbon unsaturations which are in conjugation with a carbonyl bond. Examples of suitable unsaturated polyester to be used in the resin composition of the present invention are, subdivided in the categories as classified by M. Malik et al. in J. M.S. - Rev. Macromol. Chem. Phys., C40(2&3), p.139-165 (2000).

(1 ) Ortho-resins: these are based on phthalic anhydride, maleic anhydride, or fumaric acid and glycols, such as 1 ,2-propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, 1 ,3-propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol or hydrogenated bisphenol-A. Commonly the ones derived from 1 ,2-propylene glycol are used in combination with a reactive diluent such as styrene.

(2) Iso-resins: these are prepared from isophthalic acid, maleic anhydride or

fumaric acid, and glycols. These resins may contain higher proportions of reactive diluent than the ortho resins.

(3) Bisphenol-A-fumarates: these are based on ethoxylated bisphenol-A and

fumaric acid.

(4) Chlorendics: are resins prepared from chlorine/bromine containing anhydrides or phenols in the preparation of the UP resins.

Besides these classes of resins also so-called dicyclopentadiene (DCPD) resins can be distinguished as unsaturated polyester resins. The class of DCPD-resins is obtained either by modification of any of the above resin types by Diels-Alder reaction with cyclopentadiene, or they are obtained alternatively by first reacting a diacid for example maleic acid with dicyclopentadiene, followed by the usual steps for manufacturing a unsaturated polyester resin, further referred to as a DCPD- maleate resin. Furthermore, unsaturated polyester resins based on itaconic acid as unsaturated dicarboxylic acid can be used. As used herein, a vinyl ester resin is a (meth)acrylate functional resin. The vinyl ester resin may suitably be selected from the vinyl ester resins as are known to the skilled man. Vinyl ester resins are mostly used because of their hydrolytic resistance and excellent mechanical properties. Vinyl ester resins having unsaturated sites only in the terminal position are for example prepared by reaction of epoxy oligomers or polymers (e.g. diglycidyl ether of bisphenol-A, epoxies of the phenol- novolac type, or epoxies based on tetrabromobisphenol-A) with for example

(meth)acrylic acid. Instead of (meth)acrylic acid also (meth)acrylamide may be used. As used herein, a vinyl ester resin is an oligomer or polymer containing at least one (meth)acrylate functional end group, also known as (meth)acrylate functional resins. This also includes the class of vinyl ester urethane resins (also referred to as urethane (meth)acrylate resins). Preferred vinyl ester resins are methacrylate functional resins including urethane methacrylate resins and resins obtained by reaction of an epoxy oligomer or polymer with methacrylic acid or methacrylamide, preferably with methacrylic acid. Most preferred vinyl ester resins are resins obtained by reaction of an epoxy oligomer or polymer with methacrylic acid.

The hydroxyl-functional unsaturated polyester resin with acid value < 10 as may be comprised in the resin composition according to the invention preferably has a molecular weight in the range from 500 to 10.000 Dalton, more preferably in the range from 500 to 5000 Dalton even more preferably in the range from 750 to 4000 Dalton. The hydroxyl-functional vinyl ester resin with acid value < 10 as may be comprised in the resin composition according to the invention preferably has a molecular weight in the range from 500 to 3000 Dalton, more preferably in the range from 500 to 1500 Dalton. As used herein, the molecular weight of the resin is determined in tetrahydrofurane using gel permeation chromatography according to ISO 13885-1 employing polystyrene standards and appropriate columns designed for the determination of the molecular weights.

Preferably, the acid value of the hydroxy-functional unsaturated polyester resin and hydroxy-functional vinyl ester resin is < 5 mg KOH/g resin, more preferably £ 2 mg KOH/g resin and even more preferably < 1 mg KOH/g resin. As used herein, the acid value of the resin is determined titrimetrically according to ISO 21 14- 2000.

Preferably the hydroxyl value of the hydroxy-functional unsaturated polyester resin and of the hydroxy-functional vinyl ester resin is >20 mg KOH/g resin, more preferably >30 and even more preferably >45. Preferably the hydroxyl value of the hydroxy-functional unsaturated polyester resin and of the hydroxy-functional vinyl ester resin is <250 mg KOH/g resin, more preferably <200 and even more preferably <150. As used herein, the hydroxyl value of the resin js determined according to ISO 4629-1996.

Preferably, the hydroxy-functional unsaturated polyester resin with an acid value < 10 and/or hydroxy-functional vinyl ester resin with an acid value < 10 is an hydroxy-functional unsaturated polyester, more preferably the hydroxy-functional unsaturated polyester comprises fumaric building blocks (introduced in the unsaturated polyester resin by using fumaric acid, maleic acid and/or maleic anhydride as raw material during the preparation of the unsaturated polyester resin).

All of these resins, as can suitably used in the context of the present invention, may be modified according to methods known to the skilled man, e.g. for achieving lower acid number, hydroxyl number or anhydride number, or for becoming more flexible due to insertion of flexible units in the backbone, etc. The class of DCPD- resins is obtained either by modification of any of the above resin types by Diels-Alder reaction with cyclopentadiene, or they are obtained alternatively by first reacting maleic acid with dicyclopentadiene, followed by the resin manufacture as shown above.

Of course, also other reactive groups curable by reaction with peroxides may be present in the resins, for instance reactive groups derived from itaconic acid, citraconic acid and allylic groups, etc. The unsaturated polyester resins or vinyl ester resins used in the present invention may contain solvents. The solvents may be inert to the resin system or may be reactive therewith during the curing step.

The unsaturated polyester resins as are being used in the context of the present invention may be any type of such resins, but preferably are chosen from the group of DCPD-resins, iso-phthalic resins and ortho-phthalic resins. More detailed examples of resins belonging to such groups of resins have been shown in the foregoing part of the specification. More preferably, the resin is an unsaturated polyester resin preferably chosen from the group of DCPD-resins, iso-phthalic resins and ortho-phthalic resins.

The resin composition according to the present invention generally contains less than 5 wt.% water.

According to one embodiment of the invention, the hydroxy-functional unsaturated polyester further comprises ethoxylated or propoxylated bisphenol A and/or F building blocks

The resin composition comprises at least one reactive diluent. The total amount of reactive diluents in the resin composition according to the invention is in the range from 15 to 70 wt.% (relative to the total amount of hydroxyl-functional unsaturated polyester resins with acid value < 10, hydroxyl-functional vinyl ester resins with an acid value < 10 and reactive diluent). These diluents and mixtures thereof will be applied, for instance, for lowering of the viscosity of the resin composition in order to make handling thereof more easy. For clarity purpose, a reactive diluent is a diluent that is able to copolymerize with the unsaturated polyester resin and the vinyl ester resin. Ethylenically unsaturated compounds can be advantageously used as reactive diluent such as styrene, substituted styrene like omethylstyrene, 4-methylstyrene; , (meth)acrylates, N-vinylpyrrolidone and/or N-vinylcaprolactam. Preferably, styrene, dialkyl itaconates like dimethyl itaconate and/or methacrylates are used as reactive diluents.

The second component comprises an isocyanate compound with an average functionality > 1 .7, preferably with an average functionality > 2.

Non-limiting examples of aromatic and/or aliphatic di isocyanates

(f=2) are toluene diisocyanate (TDI), 4,4'-methylene diphenyl diisocyanate (MDI), hexanediisocyanate (HDI), isopherone diisocyanate (IPDI) hydrogenated 4,4'- methylene diphenyl diisocyanate (HMDI).

Non-limiting examples of aromatic and/or aliphatic tri- isocyanates (f=3) are TDI trimers, HDI trimers and polymeric MDI . Polymeric MDI usually has an average functionality from 2 to 3 and may comprise triisocyanates next to for example diisocyanates. Mixtures of the above mentioned isocyanates can be used as well

Preferred aromatic and/or aliphatic di and/or tri- isocyanates are toluene diisocyanate (TDI), 4,4'-methylene diphenyl diisocyanate (MDI),

hexanediisocyanate (HDI), isopherone diisocyanate (IPDI) TDI trimers, HDI trimers, and polymeric MDI (pMDI) especially MDI and polymeric MDI are preferred. In a preferred embodiment of the invention, aromatic and/or aliphatic isocyanate with average functionality from 2 up to and including 3 are used as isocyanate compound. In a more preferred embodiment of the invention the isocyanate compound (C) comprises aromatic and / or aliphatic diisocyanate.

The resin composition may further comprise a radical inhibitor which retards the peroxide initiated radical copolymerization of the unsaturated polyester resin and/or vinyl ester resin with the reactive diluent. These radical inhibitors are preferably chosen from the group of phenolic compounds, hydroquinones, catechols, benzoquinones stable radicals and/or phenothiazines. The amount of radical inhibitor that can be added may vary within rather wide ranges, and may be chosen as a first indication of the pot-life as is desired to be achieved.

Suitable examples of radical inhibitors that can be used in the resin compositions according to the invention are, for instance, 2-methoxyphenol,

4-methoxyphenol, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butylphenol,

2,4,6-trimethyl-phenol, 2,4,6-tris-dimethylaminomethyl phenol,

4,4'-thio-bis(3-methyl-6-t-butylphenol), 4,4'-isopropylidene diphenol,

2,4-di-t-butylphenol, 6,6'-di-t-butyl-2,2'-methylene di-p-cresol, hydroquinone,

2-methylhydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone,

2,6-di-t-butylhydroquinone, 2,6-dimethylhydroquinone , 2,3,5-trimethylhydroquinone, catechol, 4-t-butylcatechol, 4,6-di-t-butylcatechol, benzoquinone,

2,3,5,6-tetrachloro-1 ,4-benzoquinone, methylbenzoquinone, 2,6-dimethylbenzoquinone, napthoquinone, 1 -oxyl-2,2,6,6-tetramethylpiperidine, 1 -oxyl-2,2,6,6- tetramethylpiperidine-4-ol (a compound also referred to as TEMPOL), 1 -oxyl-2,2,6,6- tetramethylpiperidine-4-one (a compound also referred to as TEMPON),

1 -oxyl-2,2,6,6-tetramethyl-4-carboxyl-piperidine (a compound also referred to as 4-carboxy-TEMPO), 1 -oxyl-2,2,5,5-tetramethylpyrrolidine,

1 -oxyl-2,2,5,5-tetramethyl-3-carboxylpyrrolidine (also called 3-carboxy-PROXYL), galvinoxyl, aluminium-N-nitrosophenyl hydroxylamine, diethylhydroxylamine, phenothiazine and/or derivatives or combinations of any of these compounds.

Advantageously, the amount of radical inhibitor in the resin

composition according to the invention (relative to the total amount of unsaturated polyester and vinyl ester resin and reactive diluent present in the resin composition) is in the range of from 0.0001 to 10 % by weight. More preferably, the amount of inhibitor in the resin composition is in the range of from 0.001 to 1 % by weight. The skilled man quite easily can assess, in dependence of the type of inhibitor selected, which amount thereof leads to good results according to the invention.

According to a preferred embodiment of the invention, the inhibitor is a stable radical more preferably from the group of stable N-oxyl radicals.

The peroxide in the resin composition can in principle be any peroxide which the iron complex can decompose into radicals. Preferably, the peroxide is selected from the group of hydroperoxides, peresters, percarbonates and perketones or perketals. The peroxide being most preferred in terms of handling properties and economics is methyl ethyl ketone peroxide (MEK peroxide, which can be regarded both as a hydroperoxide as well as a perketone). The amount of peroxide can be varied within wide ranges, in general less than 20 wt.%, and preferably less than 10 wt.% (relative to the total amount of unsaturated polyester and vinyl ester resin and reactive diluent present in the resin composition).

For obtaining improved mechanical properties the multicomponent resin system preferably further comprises fibers. The type of fiber to be used depends on the type of application. According to one preferred embodiment the fibers are glass fibers. According to yet another preferred embodiment the fibers are carbon fibers.

In certain applications like for instance automotive applications the surface quality is important therefore the invention also relates to multi-component systems whereby the system, preferably the resin composition, further comprise low profile additives. The invention further relates to multi-component systems whereby the system, preferably the resin composition, further comprises fillers and/or pigments.

The invention also relates to the cured objects or structural parts obtained by mixing the components from the multi-component system according to the invention. As used herein, the term "multi-component system" refers to systems where separate components (at least 3) are being spatially separated from each other, for instance in separate cartridges or the like, and is intended to include any system wherein each of such separate components may contain further separate compounds. The components are combined at the time the system is used.

The present invention further relates to a process for curing a resin composition comprising an hydroxyl functional unsaturated polyester resin with acid value < 10 and/or hydroxyl-functional vinyl ester resin with acid value < 10, a reactive diluent, with a peroxide and an isocyanate, wherein the curing is performed by mixing the components from the multi-component system as described above. Preferably, the curing is effected essentially free of cobalt. Essentially free of cobalt means that the cobalt concentration is lower than 0.02 mmol Co per kg unsaturated polyester resin and vinyl ester resin, preferably lower than 0.01 mmol Co per kg unsaturated polyester resin and vinyl ester resin. Most preferably the multi-component composition is free of cobalt. Preferably, the curing is effected at a temperature in the range of from -20 to +200 °C, preferably in the range of from -20 to +150 °C, more preferably in the range of from -10 to +80 °C and even more preferably at room temperature (from 20 up to and including 25 °C).

The present invention also relates to the use of a multi component system as described above in any one of the areas of chemical anchoring,

construction, roofing, flooring, windmill blades, containers, tanks, pipes, automotive parts or boats.

The present invention further relates to a process for the preparation of fiber reinforced composite materials comprising mixing the components of the multi- component system as described above; impregnating fibers with this mixture and allowing the resin composition to cure preferably at room temperature. According to a preferred embodiment, the process of fiber impregnation is performed via vacuum infusion. As fibers both organic as well as inorganic fibers can be used. Preferred inorganic fibers are glass fibers and carbon fibers.

The invention is now demonstrated by means of a series of examples and comparative examples. All examples are supportive of the scope of claims. The invention, however, is not restricted to the specific embodiments as shown in the examples.

EXPERIMENTAL

Dimethyl 2,4-di-(2-pyridyl)-3-methyl-7-(pyridine-2-ylmethyl)-3,7-diaza- bicyclo[3.3.1]nonan-9-one-1 ,5-dicarboxylate (N2Py3o) and the iron (II) complex thereof [Fe(N2Py3o)CI]CI was prepared as followed (following the procedure described in WO0248301 , page 28-34). Preparation of dimethyl 2,6-di-(2-pyridyl)-1 -methyl-piperid-4-one-3,5-dicarboxylate (NPv2)

2-Pyridinecarboxaldehyde (166.3 mmol; 17.81 g) was added drop wise to an ice-bath cooled solution of dimethyl-1 ,3-acetonedicarboxylate (83.1 mmol; 14.48 g) in methanol (60 ml). Next an aqueous solution (40%) of methylamine (83.1 mmol; 6.5 g) was added. The solution was stirred for 15 minutes at 0°C and then left at 19 °C for seven days. At this time crystals were formed that were removed by filtration and washed with cold ethanol. The yield of the title compound was 23.90 g, and it was used for further synthesis without further purification. Preparation of dimethyl 2,4-di-(2-pyridyl)-3-methyl-7-(pyridine-4-ylmethyl) 3,7-diaza- bicyclo[3.3.1lnonan-9-one-1 ,5-dicarboxylate (N2Py2Pv'o) (Ra=methylene-4-pyridyl)

To a suspension of NPy2 (32.3 mmol; 12.38 g) in 175 ml of ethanol was added an aqueous (37%) formaldehyde solution (81 mmol; 6.63 g) followed by 4- picolylamine (37.2 mmol; 4.02 g). The yellow suspension was stirred under reflux for 30 minutes, after which the suspension was turned in a clear brown solution. The solvent was removed under reduced pressure and the remaining solid was crystallized from methanol to yield 4 g (25%) of the title compound as a white solid

Preparation of dimethyl 2,4-di-(2-pyridyl)-3-methyl-7-(pyridine-2-ylmethyl) 3,7-diaza- bicyclo[3.3.1lnonan-9-one-1 ,5-dicarboxylate (N2Py3o) (Ra=methylene-2-pyridyl)

To a suspension of NPy2 (32.3 mmol; 12.38 g) in 175 ml of ethanol was added an aqueous (37%) formaldehyde solution (81 mmol; 6.63 g) followed by 2- picolylamine (37.2 mmol; 4.02 g). The yellow suspension was stirred under reflux for 30 minutes, after which the suspension was turned in a clear brown solution. The solvent was removed under reduced pressure and the remaining solid was crystallized from ethanol to yield 3.9 g (23%) of the title compound as a white solid.

Preparation of chloro(dimethyl-2,4-di-(2-pyridyl)-3-methyl-7(pyridine-2-ylmethyl)-3,7- diaza-bicvclo[3.3.1lnonan-9-one-1 ,5-dicarboxylate)iron(ll)-chloride hydrate

( e(N2Pv3o)CllCI)

Solution of 0.254 g (2.0 mmol) of FeCI2 in 1 .0 ml of methanol was added to a solution of 1 .030 g (2.0 mmol) of N2Py3o in 2 ml of methanol. After one day orange-yellow crystals precipitated from the dark brown solution.

The crystals were filtered and dried.

The crystals were either dissolved in (a) 1 ,2-propylene glycol to obtain a 1 % solution (Fe solution (a)).

The crystals were either dissolved in (b) methanol to obtain a 10% solution (Fe solution (b)).

The crystals were either dissolved in (c) 1 ,2-propylene glycol to obtain a 5% solution (Fe solution (c)).

The peroxides used for curing are commercially available products from Akzo Nobel Inc. Monitoring of curing

In the Examples presented hereinafter it is mentioned, that curing was monitored by means of standard gel time equipment. This is intended to mean that both the gel time (T_gei or T₂₅->35°c) and peak time (T_peak or T₂₅-> eak) were determined by exotherm measurements according to the method of DIN 16945 when curing the resin with the peroxides as indicated in the Examples and Comparative Examples. The equipment used therefore was a Soform gel timer, with a Peakpro software package and National Instruments hardware; the waterbath and thermostat used were respectively Haake W26, and Haake DL30. Viscosity measurements

Viscosities were measured on a Brookfield CAP1000 cone-plate viscometer using the following settings: 23°C, 750rpm and 30 sec measuring time with a CAP 2 Spindle. DMA measurements

Dynamic mechanical Analysis was performed according to ASTM D5026using a Rheometrics RSA-III employing a 1 Hz frequency over a temperature range from -130°C-250°C with a heating ramp of 5°C/min using 0.2 mm thick samples

Resin synthesis (resin A)

901 g tetrapropoxylated bisphenol A (BPA(PO)4), 1 17 g fumaric acid (FA) were charged in a vessel equipped with a stirrer, reflux condenser, a temperature measurement device and inert gas inlet. The mixture was heated slowly to 210°C at which temperature it was kept under reduced pressure until the acid value reached a value below 5mg KOH/g resin. After relieving the vacuum with nitrogen and cooling down to 170°C 12.8 g epon 828 and 90 mg triphenyl ethylphosphonium bromide in 1 .3 g ethanol were added and the reaction mixture is kept at 170°C until the acid value is below 0.5 mg KOH/g resin. After cooling down to 100°C the reaction mixture was added to a mixture of 486 g styrene and 146 mg tempol whilst maintaining a

temperature below 80°C yielding resin A with a viscosity at 23°C of 190mPa^*s and a solid content of 65.4wt%.

Example 1 and comparative experiments A-E

100 g resin A, 5 g styrene and 17.9 g polymeric methylene

diphenyldiisocyanate (pMDI) were mixed rapidly. To 1 10 g of this formulation, various metal catalysts and, when needed for the fair comparison, propylene glycol were added. After homogenization the viscosity development at 22°C was monitored in time in order to determine the pot life of the mixtures. The pot life is defined as the time which it takes until the viscosity exceeds 500 mPa.s. The results are shown in table 1.

Tablel

complex there is no effect on the rate of OH-NCO reaction (Comparing example 1 with comparative experiment E). This is very surprising as the other transition metal solutions in propylene glycol as (co)-solvent all have an accelerating effect as can be clearly seen when comparing A,B,C or D with E. The simple fact that this transition metal catalyst for the decomposition of peroxides has no effect on the OH-NCO reaction enables the separation of radical curing and OH-NCO reaction in the multi- component systems according to the invention and thus enabling long pot lifes.

Example 2

To 100 g resin A, 2.9 g styrene and 0.02 g tempol and 1 g Fe solution (b) were added. To 30 g of this resin mixture, 5.4 g polymeric methylene

diphenyldiisocyanate (pMDI) was added. After quick homogenization, 0.6 g peroxide (Perkadox CH-50L) was added and the radical cure was monitored using the gel time equipment. Free radical cure resulted in a gel time of 520 min and a peak time of 555min.

This example clearly demonstrates that it is possible to perform a free radical polymerization after the OH-NCO reaction when using a multi component resin system according to the invention. Example 3-7

To 100 g resin A, 5 g styrene and 0.1 g tempol and 2 g of Fe solution (c) were added. To 30 g of this resin mixture, 5.4 g polymeric methylene

diphenyldiisocyanate (pMDI) and 0.6 g peroxide was added. This mixture is quickly homogenised after which the radical cure was monitored with the gel time equipment. The results are shown in table 2.

Table 2

be used in the multi component resin system according to the invention. Furthermore this table indicates that by selecting a type of peroxide the man skilled in the art can easily tune the radical polymerization. It should be noted that using fast peroxides like in example 3-5 the radical reaction, when needed, can easily be retarded using various inhibitors.

Example 8

To 300 g resin A, 15 g styrene, 0.12 g tempol, 0.37g of BYK A-555 and 3 g of iron solution (a) were added. After homogenization 55 g polymeric methylene diphenyldiisocyanate (pMDI) was added. This mixture is again homogenised and subsequently degassed to eliminate entrapped air. Next 6.3 g of Butanox LPT was added and the formulation is gently homogenized resulting in a mixture with an initial viscosity of 165mPa^*s at 23°C.

From this formulation a 4mm casting was prepared and the mechanical properties were determined using DMA (see Table 3) Table 3

Table 3 clearly shows that by using multicomponent resin systems according to the invention good mechanical properties can be obtained making these multicomponent resin systems suitable for construction purposes.

Claims

1 . Multi-component system comprising a first component, a second component and a third component wherein the first component being a resin composition comprising an hydroxy-functional unsaturated polyester resin with an acid value < 10 and/or an hydroxy-functional vinyl ester resin with an acid value < 10, reactive diluent and a ligand according to the following formula (1 )

X is selected from C=0 and -[C(R)₂]_Z- wherein z is from 1 to 3 and each R is independently selected from hydrogen, hydroxyl, C1 -C4 alkoxy and C1 -C4 alkyl;

each Rx and Ry are independently selected from hydrogen, C1 -C8 alkyl, (C1 - C8)alkyl-0-(C1 -C8)alkyl, (C1 -C8)alkyl-0-(C6-C10)aryl, C6-C10-aryl, C1 -C8- hydroxyalkyl, and (CH₂)nC(0)OR₅ wherein n is from 0 to 4 and R₅ is hydrogen, C1 -C12 alkyl or an amide;

Ra is a 2-pyridyl group or an alkylidene-2-pyridyl group;

Rb is selected from C1 -C24 alkyl, C6-C10 aryl and a group containing a heteroatom;

and wherein the resin composition comprises an iron salt and/or complex; and the second component comprises an isocyanate compound with an average functionality > 1 .7,

and the third component comprises a peroxide compound.

2. Multi -component system according to claim 1 , wherein the system comprises an iron complex with the ligand according to formula (1 ). Multi -component system according anyone of the above claims, wherein Ra is methylene-2-pyridyl, R₃ and R₄ is a 2-pyridyl group, Ri and R₂ is hydrogen, X is C=0, Rx and Ry are C(0)OCH₃ and Rb is methyl.

Multi -component system according to anyone of the above claims, wherein the ligand according to formula 1 is present in an amount of from 1 to 2000 μηιοΙ per kilogram of primary resin system.

Multi -component system according to anyone of the above claims, wherein the molar ratio of iron to ligand is from 0.02 to 20, preferably from 1 to 2.

Multi-component system according to any of the above claims, wherein the hydroxy-functional unsaturated polyester resin and the hydroxy-functional vinyl ester resin has an acid value < 5 mg KOH/g resin, preferably <_2 mg KOH/g resin, more preferably < 1 mg KOH/g resin.

Multi-component system according to any of the above claims, wherein the hydroxy-functional unsaturated polyester resin and the hydroxy-functional vinyl ester resin has an hydroxyl value higher than 20 and lower than 250 mg KOH/g resin, preferably higher than 45 and lower than 150 mg KOH/g resin. Multi-component system according to any of the above claims, wherein the hydroxy-functional resin with an acid value < 10 is an hydroxy-functional unsaturated polyester.

Multi-component system according to any of the above claims, wherein the hydroxy-functional unsaturated polyester comprises fumaric building blocks Multi-component system according to any of the above claims, wherein the hydroxy-functional unsaturated polyester comprises ethoxylated or

propoxylated bisphenol A or F building blocks.

Multi-component system according to anyone of the above claims, wherein the resin composition comprises styrene, dimethyl itaconate and/or a methacrylate as reactive diluent.

Multi-component system according to any of the above claims, wherein the peroxide is selected from the group of hydroperoxides, peresters,

percarbonates and perketones.

Cured objects or structural parts obtained from a multi-component system according to any of claims 1 -12.

Process for curing a resin composition comprising an hydroxyl functional unsaturated polyester resin with acid value < 10 and/or an hydroxy-functional vinyl ester resin with acid value < 10, a reactive diluent, with a peroxide and an isocyanate, wherein the curing is performed by mixing the components from the multi-component system according to any one of claims 1 -12.

15. Process according to claim 14, wherein the curing is effected at room

temperature.

16. Use of the multi component system according to any of claims 1 -12, in any one of the areas of chemical anchoring, construction, roofing, flooring, windmill blades, containers, tanks, pipes, automotive parts or boats.

17. Process for the preparation of fiber reinforced composite materials comprising mixing the components of the multi-component system according to any of the claims 1 -12; impregnating fibers with this mixture and allowing the resin composition to cure.

18. Process according to claim 17 in which the impregnation is performed via

vacuum infusion.

19. Process according to claim 17 or 18, wherein the fibres are glass fibers or carbon fibers.