WO2015113931A1

WO2015113931A1 - Liquid curing composition for curing polymer resins (ii)

Info

Publication number: WO2015113931A1
Application number: PCT/EP2015/051471
Authority: WO
Inventors: Peter Dijkink; Maximilian Hartl; Martin Ebener; Hans-Peter Krimmer
Original assignee: Alzchem Ag
Priority date: 2014-01-29
Filing date: 2015-01-26
Publication date: 2015-08-06
Also published as: WO2015113930A1

Abstract

The invention relates to novel curing compositions for curing polymer resins

Description

Liquid hardener composition for curing polymer resins (II)

description

The present invention relates to novel hardener compositions for curing

Polymer resins.

The use of thermosetting epoxy resins is due to their good

Chemical resistance, their very good thermal and dynamic mechanical properties and their high electrical insulation capacity widely used. In addition, epoxy resins show good adhesion on many substrates and are thus ideally suited for use in fiber composites. For use in fiber composites both good wetting of the fiber, d. H. a low viscosity of the selected resin formulation for compositing as well as high mechanical properties after curing desirable.

For the production of molded parts made of fiber composite materials are various

Process used, such as, for example, the prepreg process, and various infusion or injection methods, here in particular the RT method (Resin Transfer Molding). Of these methods, infusion or injection methods in particular have become more important in recent years. Thus, for example, in the infusion process, dry reinforcing materials such as fiber mats, nonwoven fabrics, woven or knitted fabrics are covered with a dense vacuum film and soaked with resin formulations via distribution channels after application of the vacuum. These methods have the advantage that large elements with complicated geometry can be formed in a short time.

The epoxy resin formulation for an infusion or injection process must have a low viscosity to allow impregnation of the fiber materials in vacuum

appropriate time to allow. If resin formulations having excessively high viscosities are used or if resin formulations are used which too rapidly produce excessively high viscosities during the injection period, unimpregnated parts and other imperfections in the resulting composite are obtained. The curing of epoxy resins proceeds according to different mechanisms. In addition to curing with phenols or anhydrides, hardening with amines is often carried out. These substances are usually liquid and mix very well with epoxy resins.

Due to the high reactivity and thus very low latency such

Epoxy resin compositions made two-component. This means that the resin (A component) and hardener (B component) are stored separately and mixed in the correct ratio just before use. In this case, "latent" means that a mixture of the individual components is stable under defined storage conditions. These two-component resin formulations are also known as cold-curing

Resin formulations referred to, the hardener used for this are usually selected from the group of amines or amidoamines.

One-component, thermosetting epoxy resin formulations, however, are ready to use ready-made, that is, that epoxy resin and hardener are factory mixed. Mixing errors of the individual components in use on site are therefore excluded. A prerequisite for this is formed by latent hardener systems which do not react with the epoxy resin at room temperature (can be stored), but readily react when heated, depending on the energy input. For such one-component epoxy resin formulations, for example, dicyandiamide is a particularly suitable and also cost-effective hardener. Under ambient conditions, appropriate resin-hardener mixtures can be stored for up to twelve (12) months.

Unfortunately, these epoxy resin blends with high latent dicyandiamide or other highly latent hardeners have the disadvantage that the hardeners are sparingly soluble in epoxy resins and are trapped and filtered out by the fiber mats in the infusion or injection process to produce fiber composites at the resin inlet sites. Thus, a homogeneous mixture of the hardener in the resins prior to application is separated during the process and thus a uniform homogeneous mixture of the hardener in the resins in the composite prevented. This prevents hardening of the entire composite.

The patent literature describes a few suggestions for overcoming these disadvantages. Thus, both in the German patent application DE 27 43 015 A1 and the Austrian patent AT 351 772 each a method for curing epoxy resins using aqueous solutions of cyanamide or a mixture of

Cyanamid described with up to 75 wt .-% urea. The hardening can also be done under Use of catalytic amounts of accelerators can be performed. Correspondingly prepared epoxy resin compositions can be used for the production of preimpregnated glass fiber fabrics, so-called prepregs. Thus, these two patent documents describe liquid or aqueous hardener solutions. The disadvantage here, however, is that the said hardeners are solutions whose solvent water must be removed during the curing process, so as not to adversely affect the quality of the finished cured molding. This disadvantage is independent of the choice of a solvent, since these solvents must always be removed during curing. Furthermore, in the international patent applications WO 2012/1 13 879 A1 and WO 2012/1 13 178 A1 liquid hardeners for curing curable polymer resins

which comprises cyanamide and at least one urea derivative of given formula. Due to their physical properties, these hardeners are particularly suitable for use in infusion, injection or RTM procedures. Furthermore, in the patent applications WO 2014/020072 (PCT / EP20 3/066102) and WO 2014/020060 (PCT / EP2013 / 066078) liquid hardeners for curing curable polymer resins

which comprise cyanamide and at least one urea derivative of given formula and additionally at least one curing accelerator from the group of imidazolines and imidazoles of given formulas.

The present invention therefore an object of the invention, novel hardener or

Hardener compositions for curing of curable polymer resins, in particular of curable epoxy resins, as well as those hardeners or hardener compositions containing epoxy resin compositions provide, which can be used in particular for the production of composites and fiber-reinforced matrices. There was also a need for such hardeners or hardener compositions to combine the advantages of the known amine hardeners and the known dicyandiamide powder hardeners without having their disadvantages such as low latency or filtration of the particles. These new hardeners should have a high latency thus a high storage stability below the

Curing temperature and have a high reactivity at the curing temperature, allow complete crosslinking of the epoxy resin, be soluble or completely miscible in epoxy resins and be suitable for use in infusion, injection or RTM method.

According to the invention, these objects are achieved by a hardener composition according to claim 1. Accordingly, a liquid hardener composition for curing polymer resins, in particular curable polymer resins, in particular of curable epoxy resins, polyurethane resins and mixtures thereof, is the subject of the present invention Invention comprising a) cyanamide, b) at least one urea derivative of formula (I) and c) at least one curing accelerator from the class of amines according to formula (II), wherein the urea derivatives have the following structure

Where R ¹ , R ² , R ^{3 are the} same or different and at least one R ¹ , R ² or R ^{3 is} other than hydrogen: simultaneously or independently of one another, hydrogen, C 1 - to C 15 -alkyl, C3 to C15 cycloalkyl or

together C2 to C10 alkylene;

Hydrogen, C1- to C15-alkyl, C3- to C15-cycloalkyl, aryl, arylalkyl, with -NHC (O) NR R ² substituted C1- to C15-alkyl,

with -NHC (O) NR R ² substituted C3 to C15 cycloalkyl,

with -NHC (0) NR ¹ R ² substituted aryl or

with -NHC (O) NR ¹ R ² substituted arylalkyl; and wherein the amines according to formula (II) have the following structure

Formula (II) wherein for the radicals R ⁵⁰ , R ⁵ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ^{57 is the} same or independent and at least one radical R ⁵⁰ , R ⁵¹ or R ^{52 is} different of hydrogen:

= simultaneously or independently of each other hydrogen,

C1 to C10 alkyl,

Aminoalkyl with - [(R ⁵⁶ ) -N (R ⁵³ )] _n - (R ⁵⁴ ),

Amidoalkyl - [(R ⁵⁷ ) -NHC (O)] _m - (R ⁵⁵ ) or

Alkylcarbonyl with -C (O) -R ⁵⁵ ; R ⁵³ , R ⁵⁴ = simultaneously or independently of one another hydrogen,

Alkylcarbonyl with -C (0) -R ⁵⁵ or

C1 to C10 alkyl;

R ⁵⁵ = C 1 - to C 10 -alkyl or C 2 - to C 20 -alkenyl;

R ⁵⁶ , R ⁵⁷ = simultaneously or independently

C1 to C10 alkylene or

C3 to C15 cycloalkylene;

n, m = simultaneously or independently of one another an integer from 1 to 10. In particular the hardener composition according to the invention or the hardening accelerator contained therein does not comprise compounds and in particular no hardening accelerators from the class of imidazolines according to formula (III) or imidazoles according to formula (IV )

Formula (III) formula (IV) where the radicals are the same or independent of one another:

R = simultaneously or independently of one another hydrogen, C 1 - to C 20 -alkyl,

in particular C1 to C15 alkyl, G3 to C20 cycloalkyl, in particular C3 to C15 cycloalkyl, aryl, arylalkyl;

R ³² , R ³⁴ = simultaneously or independently of one another hydrogen, C 1 - to C 15 -alkyl,

C3 to C15 cycloalkyl or

together forming a ring C3 to C15 alkylene;

R ³³ , R ³⁵ = simultaneously or independently of one another hydrogen, C 1 - to C 15 -alkyl,

C3 to C15 cycloalkyl or

together to form a ring C3 to C15 alkylene.

Essential to the invention comprises a liquid hardener composition according to the

present invention cyanamide (CAS 420-04-2) and at least one urea derivative according to formula (I) with the meanings given above. Previous investigations have shown that intensive mixing of cyanamide and these urea derivatives produces liquid to semi-liquid mixtures with low melting points (compared to the Starting materials) which dissolve completely in epoxy resin at room temperature or completely mix. Although analytically separate substances are still present, DSC analyzes show endothermic melting peaks of single-component systems. Surprisingly, it has now been found that curing accelerators from the class of the amines according to formula (II) can be added to these mixtures without significantly influencing their liquid state. It has further been shown that the resulting

Hardener compositions excellent for curing of polymer resins, in particular of curable polymer resins, in particular of curable epoxy resins, curable

Polyurethane resins or mixtures thereof are suitable and the added

Hardening accelerator curing of the polymer resins in comparison to a cure without these amines accelerate. Their mode of action in the epoxy resin is comparable to the curing properties of imidazole-accelerated dicyandiamide. In contrast to epoxy resin compositions containing amines or aminoamines in one

Cured two-component system, however, a latency of several days is maintained at room temperature. This is all the more surprising as it is widely known that amines show a high reactivity in epoxy resins as curing agents for epoxy resins even at room temperature and thus are classified as little latent. In addition, hardened polymer resins can be provided with the hardener compositions according to the invention, which are high in comparison with amine resins cured polymer resins

Have glass transition temperatures. These results were unpredictable in their entirety.

In general, it should be noted that a hardener curing, ie the networking of

Polymer resins, in particular of epoxy resins causes. By contrast, a cure accelerator does not cure itself per se, but rather lowers the activation energy of hardeners. By adding hardening accelerators, in particular, curing takes place even at low temperature.

Overall, a hardener composition can thus be provided due to the high latency in the polymer resin compositions as well as the high reactivity in the polymer resin compositions at the curing temperature

Excellent for use in infusion or injection procedures.

In a further development of the present invention, it may be provided that the liquid hardener composition cyanamide and at least one urea derivative of the formula (I) or mixtures of these urea derivatives are preferably in a molar ratio

Cyanamide: urea derivative or urea derivative mixture of 1: 1 to 4: 1. In particular, it is provided according to the present invention that the molar ratio cyanamide: urea derivative or urea derivative mixture is in particular from 1: 1 to 3: 1 and further preferably from 1: 1 to 2: 1 or more preferably from 2: 1 to 4: 1.

In the presence of a cure accelerator from the class of amines of formula (II), the molar ratios of cyanamide: urea derivative may also be outside the preferred range of 1: 1 to 4: 1. For example, molar ratios of cyanamide: urea derivative of 0, 1 to <1: 1, in particular from 0.2 to <1: 1, possible, but also molar ratios of cyanamide: urea derivative of> 4: 1 to 20: 1, in particular > 4: 1 to 10: 1.

In this case, a hardener composition according to the present invention is to be understood as meaning a hardener composition which has a melting point S _m with S _m <20 ° C. (normal pressure) or is liquid at a temperature of 20 ° C. (normal pressure) and has a viscosity of less than 1 Pa * s has. The liquid hardener compositions according to the invention preferably have a viscosity of about 300 mPa * s, more preferably <200 mPa * s and even more preferably about 100 mPa ^* s at 25 ° C.

(Normal pressure). However, particularly preferred are those liquid

Hardener compositions having a melting point S _m with S _m <10 ° C (atmospheric pressure), most preferably a melting point S _m with S _m <0 ° C (atmospheric pressure), or at a temperature of

10 ° C (atmospheric pressure), most preferably at a temperature of 0 ° C.

(Normal pressure), liquid and have a viscosity of less than 1 Pa ^* s.

It should be emphasized in this case that these hardener compositions are liquid as such and in particular in addition to cyanamide, at least one urea derivative or mixtures thereof and at least one curing accelerator from the class of amides according to formula (II) in particular no solvent and / or no solubilizer and thus solvent-free or / and solubilizer-free. It is in connection with the present invention under a solvent or solubilizer Any

inorganic or organic solvents or solubilizers or mixtures thereof, which is used in the chemical synthesis or in the analysis for the preparation of a solution. However, viscosity modifiers according to the present invention are not solvents. In the context of the present invention, a hardener composition is understood to be solvent-free or solubilizer-free, which in the Essentially free of solvents or solubilizers and manufacturing conditionally contains at most 1, 0 wt .-% solvent or solubilizer.

In an alternative embodiment, it is also possible that the

Hardener composition containing a solvent, in particular water. The addition of solvent is not required to make the mixtures liquid, but may be favorable for other process engineering requirements.

Furthermore, in the context of the present invention, C 1 - to C 15 -alkyl is intended to mean a linear or, in turn, alkyl-substituted alkyl radical having a chain length of up to 15

Be understood carbon atoms, which in particular has the general formula C _n H _{2n +} i, where n = 1 to 15 meaning. It is preferably provided that C 1 - to C 15 -alkyl methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl or pentadecyl, these alkyl radicals furthermore preferably unbranched or in turn may be monosubstituted or polysubstituted alkyl. If a C 1 - to C 15 -alkyl in turn is alkyl-substituted, preference is given to C 1 - to C 15 -alkyl radicals which in turn are substituted by C 1 - to C 5 -alkyl. In this case, C 1 - to C 5 -alkyl may furthermore preferably be methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl,

2-methylpropyl, 1, 1-dimethylethyl], n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1, 1-dimethylpropyl, 1, 2-dimethylpropyl, 2,2-dimethylpropyl or 1-ethylpropyl.

Furthermore, in the context of the present invention, C 1 - to C 10 -alkyl is understood to mean a linear or, in turn, alkyl-substituted alkyl radical having a chain length of up to 10 carbon atoms, in particular the general formula C _n H _{2n +} i

where n = 1 to 10. It is provided in particular that C 1 - to C 10 -alkyl methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl, where these alkyl radicals may furthermore preferably be unbranched or themselves mono- or polysubstituted alkyl. Should a C 1 - to C 10 -alkyl radical in turn be alkyl-substituted, preference is given to C 1 - to C 10 -alkyl radicals which in turn are substituted by C 1 - to C 5 -alkyl. C.sub.1-5-alkyl may furthermore preferably be methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl,

2-methylbutyl, 3-methylbutyl, 1, 1-dimethylpropyl, 1, 2-dimethylpropyl, 2,2-dimethylpropyl or 1-ethylpropyl mean.

Preference is given to those C.sub.1-C.sub.15-alkyl radicals or those C.sub.1-C.sub.10-alkyl radicals which, in turn, are monosubstituted or polysubstituted by alkyl, in particular by C1- to C5-alkyl. Thus, C1 to C15 alkyl and simultaneously or independently thereof C 1 - to C 10 -alkyl according to the present invention, in particular also 1-methylethyl, 1-methylpropyl, 1-methylbutyl, 1-methylpentyl, 1-methylhexyl, 1-methylheptyl, 1-methyloctyl, 1-methylnonyl, 1-ethyldecanyl, 1 Ethylpropyl, 1-ethylbutyl, ethylpentyl, 1-ethylhexyl,

1-ethylheptyl, 1-ethyl octyl, 1-ethylnonyl, 1-ethyldecanyl, 2-methylpropyl, 2-methylbutyl,

2-methylpentyl, 2-methylhexyl, 2-methylhexyl, 2-methyl-octyl, 2-ethylnonyl,

2-methyldecanyl, 2-ethylpropyl, 2-ethylbutyl, 2-ethylpentyl, 2-ethylhexyl, 2-ethylheptyl, 2-ethyloctyl, 2-ethylnonyl, 2-ethyldecanyl, 1, 1-dimethylethyl, 1, 1-dimethylpropyl,

1, 1-dimethylbutyl, 1, 1-dimethylpentyl, 1, 1-dimethylhexyl, 1, 1-dimethylheptyl,

1, 1-dimethyloctyl, 1, 1-dimethylnonyl, 1, 1-dimethyldecanyl, 1, 2-dimethylpropyl,

1,2-dimethylbutyl, 1, 2-dimethylpentyl, 1, 2-dimethylhexyl, 1, 2-dimethylheptyl,

1, 2-dimethyloctyl, 1, 2-dimethylnonyl, 1, 2-dimethyldecanyl, 2-ethyl-1-methylbutyl,

2-ethyl-1-methylpentyl, 2-ethyl-1-methylhexyl, 2-ethyl-1-methylheptyl, 2-ethyl-1-methyloctyl, 2-ethyl-1-methylnonyl, 2-ethyl-1-methyldecanyl, 1 - ethyl-2-methylpropyl,

1-ethyl-2-methylbutyl, 1-ethyl-2-methylpentyl, 1-ethyl-2-methylhexyl, 1-ethyl-2-methylheptyl, 1-ethyl-2-methyl-1-ethyl-1-ethyl-2-methylnonyl or 1-ethyl-2-methyldecanyl.

Further preferably, a C 1 - to C 15 -alkyl radical or a C 1 - to C 10 -alkyl radical, in particular methyl, ethyl, propyl, butyl, in turn be substituted by a C 3 - to C 15 -cycloalkyl radical or C 3 - to C 10 -cycloalkyl radical, where C 3 - to C 15 -cycloalkyl and C 3 to C 10 -cycloalkyl has the meaning given below. Thus, C1- to C15-alkyl, in particular also C3- to C15-cycloalkylmethyl, 1- (C3- to C5-cycloalkyl) -1-ethyl, 2- (C3- to C15-cycloalkyl) -1-ethyl, 1- (C3 to C15 cycloalkyl) -1-propyl, 2- (C3 to C15 cycloalkyl) -1-propyl or 3- (C3 to C15 cycloalkyl) -1-propyl, wherein C3 bis C15 cycloalkyl having the order given below. In particular, C1-C10-alkyl may also be C3-C10-C5cycloalkyl-methyl, C3-C10-C10-cycloalkyl-1-ethyl, C3-C10-cycloalkyl-1-ethyl, 1- (C3 to C10 cycloalkyl) -1-propyl, 2- (C3 to C10 cycloalkyl) -1-propyl or 3- (C3 to C10 cycloalkyl) -1-propyl, where C3- until G10-cycloalkyl has the order given below.

In the context of the present invention, C3- to C15-cycloalkyl is understood as meaning a monocyclic or bicyclic cycloalkyl radical having 3 to 15 carbon atoms, in particular a cycloalkyl radical which has the general formula C _n H _2n -i where n = 3 to 15. C 3 -C 15 -cycloalkyl, cyclopropyl, cyclobutyl,

Cyclopentyl, cyclohexyl or cycloheptyl, wherein these cycloalkyl radicals in turn further preferably mono- or polysubstituted with C1 to C5-alkyl radicals of the above

can be substituted. It is furthermore preferably possible for C 3 -C 15 -cycloalkyl to also contain 1-methyl-1-cyclopropyl, 1-methyl-cyclobutyl, 1-methyl-1 Cyclopentyl, 1-methyl-1-cyclohexyl, 1-methyl-1-cycloheptyl, 2-methyl-1-cyclopropyl, 2-methyl-1-cyclobutyl, 2-methyl-1-cyclopentyl, 2-methyl-1-cyclohexyl, 2-methyl-1-cycloheptyl, 3-ethyl-1-cyclobutyl, 3-methyl-1-cyclopentyl, 3-methyl-1-cyclohexyl, 3-methyl-cycloheptyl, 4-methyl-1-cyclohexyl, 4-methyl 1-cycloheptyl, 1, 2-dimethyl-1-cyclopropyl,

2.2-dimethyl-1-cyclopropyl, 2, 3-dimethyl-1-cyclopropyl, 1, 2-dimethyl-1-cyclobutyl,

1,3-dimethyl-1-cyclobutyl, 2,2-dimethyl-1-cyclobutyl, 2,3-dimethyl-1-cyclobutyl,

2,4-dimethyl-1-cyclobutyl, 3,3-dimethyl-1-cyclobutyl, 1, 2-dimethyl-1-cyclopentyl,

1, 3-dimethyl-1-cyclopentyl, 2,2-dimethyl-1-cyclopentyl, 2,3-dimethyl-1-cyclopentyl,

2,4-dimethyl-1-cyclopentyl, 2,5-dimethyl-1-cyclopentyl, 3,3-dimethyl-1-cyclopentyl, 3,4-dimethyl-1-cyclopentyl, 1, 2-dimethyl-1-cyclohexyl, 1, 3-dimethyl-1-cyclohexyl,

1, 4-dimethyl-1-cyclohexyl, 1, 5-dimethyl-1-cyclohexyl, 1, 6-dimethyl-1-cyclohexyl,

2, 2-Dimethyl-1-cyclohexyl, 2,3-dimethyl-1-cyclohexyl, 2,4-dimethyl-1-cyclohexyl,

2.5-dimethyl-1-cyclohexyl, 2,6-dimethyl-1-cyclohexyl, 3,3-dimethyl-1-cyclohexyl,

3,4-dimethyl-1-cyclohexyl, 3,5-dimethyl-1-cyclohexyl, 3,6-dimethyl-1-cyclohexyl,

4,4-dimethyl-1-cyclohexyl, 1, 2, 2-trimethyl-1-cyclopropyl, 1, 2,3-trimethyl-1-cyclopropyl,

1,2,2-trimethyl-1-cyclobutyl, 1,3,3-trimethyl-1-cyclobutyl, 1,2,3-trimethyl-1-cyclobutyl,

2.2.3- trimethyl-1-cyclobutyl, 2, 2,4-trimethyl-1-cyclobutyl, 1,2,2-trimethyl-1-cyclopentyl,

1, 2, 3-trimethyl-1-cyclopentyl, 1, 2,4-trimethyl-1-cyclopentyl, 1, 2, 5-trimethyl-1-cyclopentyl, 1, 3, 3-trimethyl-1-cyclopentyl, 1, 3,4-trimethyl-1-cyclopentyl, 1, 3,5-trimethyl-1-cyclopentyl, 2,2,3-trimethyl-1-cyclopentyl, 2,2,4-trimethyl-1-cyclopentyl, 2,2, 5-trimethyl-1-cyclopentyl, 2,3,3-trimethyl-1-cyclopentyl, 2, 3,4-trimethyl-1-cyclopentyl, 2,3,5-trimethyl-1-cyclopentyl, 2,3,3- Trimethyl-1-cyclopentyl, 2,4,4-thymyl-1-cyclopentyl, 2,4,5-trimethyl-1-cyclopentyl, 2,5,5-trimethyl-1-cyclopentyl, 3,3,4-trimethyl 1-cyclopentyl, 3,3,5-trimethyl-1-cyclopentyl,

3,4,5- trimethyl-1-cyclopentyl, 3,4,4-trimethyl-1-cyclopentyl, 1,2,3-trimethyl-1-cyclohexyl, 1,2,3-trimethyl-1-cyclohexyl, 1,2, 4-trimethyl-1-cyclohexyl, 1, 2, 5-trimethyl-1-cyclohexyl,

1 .2.6-trimethyl-1-cyclohexyl, 1, 3, 3-trimethyl-1-cyclohexyl, 1, 3,4-trimethyl-1-cyclohexyl,

1 .3.5- trimethyl-1-cyclohexyl, 1, 3, 6-trimethyl-1-cyclohexyl, 1,4,4-trimethyl-1-cyclohexyl, 2,2,3-trimethyl-1-cyclohexyl, 2,2, 4-trimethyl-1-cyclohexyl, 2,2,5-trimethyl-1-cyclohexyl,

2.2.6- trimethyl-1-cyclohexyl, 2,3,3-trimethyl-1-cyclohexyl, 2,3,4-trimethyl-1-cyclohexyl, 2, 3, 5-trimethyl-1-cyclohexyl, 2,3, 6-trimethyl-1-cyclohexyl, 2,4,4-trimethyl-1-cyclohexyl,

2,4,5-trimethyl-1-cyclohexyl, 2,4,6-trimethyl-1-cyclohexyl, 2,5,5-trimethyl-1-cyclohexyl,

2.5.6- trimethyl-1-cyclohexyl, 2, 6, 6-trimethyl-1-cyclohexyl, 3,3,4-trimethyl-1-cyclohexyl, 3, 3, 5-trimethyl-1-cyclohexyl, 3, 3, 6-trimethyl-1-cyclohexyl, 3,4,4-trimethyl-1-cyclohexyl, 3,4,5-trimethyl-1-cyclohexyl, 3,4,6-trimethyl-1-cyclohexyl, 3,5,6- Trimethyl-1-cyclohexyl,

1, 2,3,3-tetramethyl-1-cyclopropyl, 2,2,3,3-tetramethyl-1-cyclopropyl, 1, 2,2,3-tetramethyl-1-cyclopropyl, 1, 2,2, 3 Tetramethyl-1-cyclobutyl, 1, 2,3,3-tetramethyl-1-cyclobutyl,

2,2,3,3-Tetramethyl-cyclobutyl, 2,3,3,4-tetramethyl-1-cyclobutyl, 1, 2,2,3-tetramethyl-1 - Cyclopentyl, 1, 2,2,4-tetramethyl-1-cyclopentyl, 1, 2,2,5-tetramethyl-1-cyclopentyl,

1, 2, 3, 3-tetramethylMyclopentyl, 1,2,3,4-tetramethyl-1-cyclopentyl, 1,2,3,5-tetramethyl-1-cyclopentyl, 1,2,5,5-tetramethyl- 1-cyclopentyl, 2, 2, 3, 3-tetramethylcyclopentyl,

2,2,3,3-tetramethyl-1-cyclohexyl, 2,2,4,4-tetramethyl-1-cyclohexyl, 2,2,5,5-tetramethyl-1-cyclohexyl, 3,3,4,4- Tetramethyl-1-cyclohexyl, 3,3,5,5-tetramethyl-1-cyclohexyl, 1-ethyl-1-cyclopropyl, 1-ethyl-1-cyclobutyl, 1-ethyl-1-cyclopentyl, 1-ethyl-1 - Cyclohexyl), 1-ethyl-1-cycloheptyl, 2-ethyl-1-cyclopropyl, 2-ethyl-1-cyclobutyl, 2-ethyl-1-cyclopentyl, 2-ethyl-1-cyclohexyl, 2-ethyl-1-cycloheptyl , 3-ethyl-1-cyclobutyl, 3-ethyl-1-cyclopentyl, 3-ethyl-1-cyclohexyl, 3-ethyl-1-cycloheptyl, 4-ethyl-1-cyclohexyl or 4-ethyl-1-cycloheptyl.

In the context of the present invention, further C3-to C10-cycloalkyl is an unsubstituted or in turn alkyl-substituted monocyclic

Be understood cycloalkyl radical having 3 to 10 carbon atoms in the ring, which in particular has the general formula C _n H _2n -i with n = 3 to 10. C 3 -C 10 -cycloalkyl may furthermore preferably be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl, these cycloalkyl radicals furthermore preferably being mono- or polysubstituted

may be alkyl-substituted. Should a C3 to C10 cycloalkyl radical in turn be alkyl-substituted, C3 to C10 cycloalkyl radicals are preferred, which in turn are substituted by C1 to C5 alkyl. In this case, C 1 - to C 5 -alkyl may furthermore preferably have the abovementioned meaning.

According to the present invention, R ¹ and R ² according to formula (I) may also together be C ² - to C 10 -alkylene, where R ¹ and R ² together with the nitrogen of the

Urea derivatives form a nitrogen-containing ring. In particular, it may be provided in this case that R ¹ and R ² together denote ethylene, propylene, butylene, pentylene or hexylene, these alkylene radicals in turn may optionally be mono- or polysubstituted by alkyl radicals. In this case, R ¹ and R ² together with the nitrogen of the urea derivative forms an aziridine, azetidine, azolidine, azinan or azepane, which in turn may optionally be monosubstituted or polysubstituted by C 1 - to C 5 -alkyl radicals of the meaning given above.

According to the present invention, -NHC (O) NR ¹ R ^{2 represents} a 1-uryl radical substituted on nitrogen N 3 with the radicals R ¹ and R ² , wherein R ¹ and R ² are as above

have meanings given, and the via the nitrogen N 1 to a

Backbone is bound.

Halogen means according to the present invention, in particular fluorine, chlorine or bromine. According to the present invention, aryl is an aromatic aryl radical, in particular an aromatic aryl radical having 3 to 20 carbon atoms, in particular a monocyclic or bicyclic aromatic aryl radical having 3 to 20 carbon atoms, which furthermore preferably in turn is monosubstituted or polysubstituted by a C1 to C5 radical. Alkyl radical of the meaning given above can be substituted. Particularly preferably it can be provided that the aryl radical used is a benzene radical (phenyl), naphthalene radical (naphthyl), anthracene radical or perylene radical, which in turn may be monosubstituted or polysubstituted by a C 1 - to C 5 -alkyl radical of the meaning given above , Thus, aryl in particular also denotes toluyl, xylenyl, pseudocumolyl or mesitylenyl.

According to the present invention, arylalkyl means a C 1 -C 15 -alkyl radical of the meaning given above, which is substituted by an aryl radical of the meaning given above. In particular, arylalkyl may be a benzyl radical.

Particular preference is given to liquid hardener compositions according to the invention comprising at least one aliphatic urea derivative according to formula (I). In these aliphatic urea derivatives according to formula (I), R ¹ and R ^{2 are} simultaneously or independently hydrogen or C ¹ - to C 15 -alkyl and R ³ is hydrogen, C ¹ - to C -alkyl, C ³ - to C -cycloalkyl, with -NHC (O) NR R ² substituted C1 to C15-alkyl or C1-C15-cycloalkyl substituted with -NHC (0) NR ¹ R ² .

Particularly preferably, the inventive liquid

Hardener compositions at least one urea derivative of the formula (I) in which at least one of the radicals R ¹ and R ^{2 is} a methyl radical. Particularly preferred is methylurea, 1, 3-dimethylurea or 1, 1-dimethylurea (ie R ¹ = R ² = methyl and

R ³ = H).

Further preferred are aliphatic urea derivatives according to formula (I), in which R ¹ and R ^{2 have} the abovementioned meaning, in particular hydrogen, methyl or ethyl, and R ³ with -NHC (O) NR R ² substituted C1 to C15 cycloalkyl means. Very particular preference is given to liquid hardener compositions comprising aliphatic urea derivatives of the formula (V)

Formula (V) where the radicals are the same or independent of each other:

R ¹ , R ² simultaneously or independently

Is hydrogen, C1 to C15 alkyl, C3 to C15 cycloalkyl or

together C2 to C10 alkylene;

R ⁴ , R ⁴ , R ⁵ , R ⁵ , R ⁶ , R ⁶ , R ⁷ , R ^{7 '} , R ⁸ , R ^8' = simultaneously or independently

Hydrogen, C1 - to C15-alkyl C3- to C15-

Cycloalkyl, -NHC (O) NR ¹ R ² or

with -NHC (O) NR R ² substituted C1 to C5 alkyl.

Also preferred are liquid hardener compositions comprising aliphatic urea derivatives of the formula (V) in which R ¹ and R ^{2 are,} simultaneously or independently, hydrogen or methyl and R ⁴ , R ⁴ , R ⁵ , R ⁵ , R ⁶ , R ⁶ , R ⁷ , R ⁷ , R ⁸ , R ^{8 are,} simultaneously or independently, hydrogen, methyl, ethyl, -NHC (O) NR R ² or -NHC (O) NR ¹ R ² substituted methyl or ethyl. Particularly preferred is 1 - (N, N-dimethylurea) -3- (N, N-dimethylureamethyl) -3,5,5-trimethylcyclohexane, hereinafter also N '- [3- [[[(dimethylamino) carbonyl] amino] methyl ] -3,5,5-trimethylcyclohexyl] -N, N-dimethyl-urea (ie R ¹ = R ² = R ⁵ = R ^{5 '} = R ⁷ = methyl and R ^7' = -CH ₂ -NHC (0) N (CH ₃ ) ₂ and R ⁴ = R ⁴ = R ⁶ = R ⁶ = R ⁸ = R ⁸ = hydrogen).

In an alternative embodiment, however, it can also be provided that a

A liquid hardener composition according to the invention comprises an aromatic urea derivative. Thus, this liquid curing agent compositions comprise at least one urea derivative of the formula (I) in which the radical R ³ = aryl, arylalkyl, with -NHC (0) NR ¹ R ² substituertes aryl or -NHC (0) NR R ² substituertes arylalkyl for a Rest of the general formula (VI) stands

Formula (VI) where the radicals R ¹ , R ^{2 have} the abovementioned meaning and for the other radicals simultaneously or independently of one another:

Hydrogen, halogen, C1 to C15 alkyl, C3 to C15 cycloa

Aryl, arylalkyl, -CF ₃ , -NHC (O) NR ¹ R ² ,

with -NHC (O) NR ¹ R ² substituted C ¹ - to C 15 -alkyl,

with -NHC (O) NR R ² substituted aryl or

with -NHC (0) NR ¹ R ² substituted arylalkyl:

simultaneously or independently hydrogen or

C1 to C5 alkyl;

an integer from 0 to 10.

Of these aromatic urea derivatives, those are particularly preferred

Urea derivatives in which the radicals R ⁴ , R ⁵ , R ^e , R ⁷ and R ^{8 are,} simultaneously or independently, hydrogen, C 1 - to C 15 -alkyl, -NHC (O) NR R ² , with -NHC (O) NR ¹ R ² substituted C1 - to C15-aryl or -NHC (0) NR R ² substituted C1- to C 5 -arylalkyl. Also preferred are liquid hardener compositions comprising urea derivatives of the formula (VII)

Formula (VII) in which R ¹ , R ² , R ⁴ and R ^{5 have} the meanings given above and in particular simultaneously or independently of one another represent hydrogen, C ¹ -C 5 -alkyl. The radicals R ¹ and R ² in connection with the formula (VII) preferably represent a methyl radical. 1, 1 '- (4-methyl-m-phenylene) bis (3,3-dimethylurea) and 1, 1' - (2-methyl-m-phenylene) bis- (3,3-) are particularly preferred. dimethylurea) (ie R ¹ = R ² = R ⁵ methyl and R ^{4 is} hydrogen). According to a further embodiment it can be provided in particular that the liquid hardener compositions according to the invention a) cyanamide, b) two different urea derivatives of the formulas (I), (V) and / or (VII) and c) at least one curing accelerator from the class of amines according to formula (II), in particular, these hardener compositions furthermore preferably containing cyanamide and two different urea derivatives of the formula (I), (V) and / or (VII) in a molar ratio cyanamide: urea derivative or urea derivative mixture of 1 : 1 to 4: 1, especially included.

According to a further embodiment of the invention are such liquid

The invention relates to hardener compositions which comprise a) cyanamide, b) at least one urea derivative selected from the group consisting of urea, 1-methylurea,

1, 1-dimethylurea, 1, 3-dimethylurea, 3- (3-chloro-4-methylphenyl) -1, 1-dimethylurea, 3- (p-chlorophenyl) -1, 1-dimethylurea, 3-phenyl-1, 1-dimethylurea, 3- (3,4-dichlorophenyl) -1, 1-dimethylurea, 1, 1 '- (methylenedi-p-phenylene) bis (3,3-dimethylurea), 3- (3-trifluoromethylphenyl) 1, 1-dimethylurea,

1, 1 '- (2-methyl-m-phenylene) bis- (3,3-dimethylurea) and / or 1, 1' - (4-methyl-m-phenylene) - bis- (3,3-dimethylurea ) and c) comprise at least one curing accelerator from the class of amines according to formula (II), in particular, wherein further preferably cyanamide and the urea derivative or urea derivative mixture in a molar ratio of 1: 1 to 4: 1 are used.

Essential to the invention, liquid hardener compositions according to the present invention comprise at least one curing accelerator from the class of amines according to formula (II). These amines, in combination with liquid cyanamide masterbatches and at least one urea derivative of the type described herein, have a very good curing accelerator activity, with little or no change in the liquid properties. Although they are amines of different structure, these cure accelerators can be used without affecting significant physical properties of the curing agent compositions. By using different amine curing accelerators, however, can be compared to each other

Hardener compositions are provided which initiate a different speed curing of polymer resins, especially epoxy resins. Overall, therefore, a hardener composition can be provided which, due to their high latency in the polymer resin compositions, in particular in epoxy resin compositions, as well as the high reactivity in the polymer resin compositions, in particular in Epoxy resin compositions where cure temperature is excellent for use in infusion or injection procedures.

Substantially essential to the invention, amines of the formula (II) can be used, for the radicals R ⁵⁰ to R ^{57 are the} same or independent and at least one radical R ⁵⁰ , R ⁵¹ or R ^{52 is} different from hydrogen:

R ⁵⁰ , R ⁵¹ , R ⁵² = simultaneously or independently of one another hydrogen,

C1 to C10 alkyl,

Aminoalkyl with - [(R ⁵⁶ ) -N (R ⁵³ )] _n - (R ⁵⁴ ),

Amidoalkyl - [(R ⁵⁷ ) -NHC (O)] _m - (R ⁵⁵ ) or

Alkylcarbonyl with -C (O) -R ⁵⁵ ;

R ⁵³ , R ⁵⁴ = simultaneously or independently of one another hydrogen,

Alkylcarbonyl with -C (0) -R ⁵⁵ or

C1 - to C10-A! Kyl;

R ⁵⁵ = C 1 - to C 10 -alkyl or C 2 - to C 20 -alkenyl;

R ⁵⁶ , R ⁵⁷ = simultaneously or independently

C1 to C10 alkylene or

C3 to C15 cycloalkylene;

n, m = simultaneously or independently of one another an integer from 1 to 10.

According to the present invention, R or R may be C1 to C10 alkylene or C3 to C10 cycloalkylene. Under C1 to C10 alkylene is to be understood as a divalent alkyl radical having a chain length of up to 10 carbon atoms, which in particular has the general formula C _n H _2n , where n = 1 to 10. In particular, it may be provided here that R ⁵⁶ or R ⁵⁷ denote methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene or decanylene, these alkylene radicals in turn may optionally be mono- or poly-alkyl substituted. Should a C 1 - to C 10 -alkylene in turn be alkyl-substituted, preference is given to C 1 - to C 10 -alkylene radicals which in turn are substituted by C 1 - to C 5 -alkyl according to the abovementioned meaning. The binding sites may be located at both the backbone and the alkyl substituent.

However, according to the present invention, R ⁵⁶ or R ⁵⁷ may also be C 3 to C 15 cycloalkylene. Here, C3-C15-cycloalkylene is intended to mean a monocyclic or bicyclic, divalent cycloalkyl radical having 3 to 15 carbon atoms, in particular has the general formula C _n H _2n , where n = 1 to 15. In particular, it may be provided here that R ⁵⁶ or R ^{57 is} cyclohexylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, ethylene-bis-cyclopentylene or methylene-bis-cyclohexylene, where these cycloalkylene radicals may in turn be optionally mono- or poly-alkyl-substituted. If a C3 to C15-cycloalkylene in turn be alkyl-substituted, then C3 to C15-cycloalkylene radicals are preferred, which in turn are substituted by C1 to C5-alkyl according to the abovementioned meaning. The binding sites may be located at both the cycloalkyl ring and the alkyl substituent.

Furthermore, in the context of the present invention, C 2 -C 20 -alkenyl is to be understood as meaning a linear or, in turn, alkyl-substituted alkenyl radical having a chain length of 2 to 20 carbon atoms, each having one to four double bonds

in particular the general formula C _n H _2n .i with n = 2 to 20, C _n H _2n -3 with n = 4 to 20, C _n H _2n -5 with n = 6 to 20 or C _n H _2n _ ₇ with n = 8 to 20. It is particularly provided that C2 to C20 alkenyl ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl,

Hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, butadienyl, pentadienyl, hexadienyl, heptadienyl, octadienyl, nonadienyl, decadienyl, undecadienyl, dodecadienyl, tridecadienyl, tetradecadienyl, pentadecadienyl, hexadecadienyl, heptadecadienyl,

Octadecadienyl, nonadecadienyl, eicosadienyl, hexatrienyl, heptatrienyl, octatrienyl, nonatrienyl, decatrienyl, undecatrienyl, dodecatrienyl, tridecatrienyl, tetradecatrienyl, pentadecatrienyl, hexadecatrienyl, heptadecatrienyl, octadecatrienyl, nonadecatrienyl or eicosatrienyl, these alkenyl radicals furthermore preferably being unbranched or in turn being monosubstituted or polysubstituted by alkyl can. If a C 2 - to C 20 -alkenyl radical in turn be alkyl-substituted, preference is given to C 2 - to C 20 -alkenyl radicals which are in turn substituted by C 1 - to C 5 -alkyl. In this case, C 1 - to C 5 -alkyl may furthermore preferably have the abovementioned meaning.

According to the present invention, preference is given to curing accelerators of the class of the amines according to formula (II), to which the following applies: where R ⁵⁰ , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ^{56 are the} same or independent of one another and at least one radical R ⁵⁰ , R ⁵¹ or R ^{52 is} different from hydrogen:

Aminoalkyl with - [(R ⁵⁶ ) -N (R ⁵³ )] _n - (R ⁵⁴ ),

R ⁵³ , R ⁵⁴ = simultaneously or independently of one another hydrogen, methyl, or ethyl R ⁵⁶ = C 1 - to C 10 -alkylene or

C3 to C15 cycloalkylene;

n = an integer from 1 to 10.

However, according to the present invention, such may alternatively be used

Hardening accelerators from the class of amines according to formula (II) are used, for which applies: wherein for the radicals R ⁵⁰ , R ⁵¹ , R ⁵² , R ^{55 are the} same or independently and at least one radical R ⁵⁰ , R ⁵ or R ⁵² is different from hydrogen:

R ⁵⁰ , R ⁵ , R ⁵² = simultaneously or independently of one another hydrogen,

C1 - to Cl-O-alkyl, or

Alkylcarbonyl with -C (O) -R ⁵⁵ ;

R ⁵⁵ = C 1 - to C 10 -alkyl or C 2 - to C 20 -alkenyl.

Further preferred are amines according to formula (II) for which applies: wherein for the radicals R ⁵⁰ , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁶ simultaneously or independently and at least one radical R ⁵⁰ , R ⁵¹ or R ^{52 is} different from hydrogen:

Aminoalkyl with - [(R ⁵⁶ ) -N (R ⁵³ )] _n - (R ⁵⁴ ),

R ⁵³ , R ⁵⁴ = simultaneously or independently

Hydrogen, methyl, or ethyl

R ⁵⁶ = methylene, ethylene, propylene, 1, 3 '- (3,5,5-methyl) hexylene, methylene-bis-cyclohexylene,

n = an integer from 1 to 10.

By way of example and not by way of limitation, the curing accelerators according to the invention from the class of amines of the general formula (II) are preferred representatives

Diethylenetriamine (R ⁵⁰ = R ⁵¹ = R ⁵³ = R ⁵⁴ = hydrogen, R ⁵⁶ = ethylene, n = 2),

Triethylenetetramine (R ⁵⁰ = R ⁵¹ = R ⁵³ = R ⁵⁴ = hydrogen, R ⁵⁶ = ethylene, n = 3),

Isophoronediamine (R ⁵⁰ = R ⁵¹ = R ⁵³ = R ⁵⁴ = hydrogen, R ⁵⁶ = 3-methylene-3,5,5-trimethylhexylene, n = 1) and / or 2,2'-dimethyl-4,4'methylene -bis-cyclohexylamine (R ⁵⁰ = R ⁵¹ = R ⁵³ = R ⁵⁴ = hydrogen, R ⁵⁶ = 2,2'-dimethyl-4,4'methylene-bis-cyclohexylene, n = 1) used. In addition, studies have shown that better processing can be provided in infusion or injection processes, but also in prepreg processes, of a polymeric resin composition, especially an epoxy resin composition comprising a liquid hardener of the type described herein, if the liquid hardeners Furthermore, a viscosity modifier is added. So can

For example, to prepare prepregs, a viscosity modifier may be used which causes an increase in viscosity of the resulting resin composition. As a result, a particularly good adhesion of the resulting resin composition is achieved on the Trägerermatrialien. On the other hand, the viscosity of the resin composition to be produced can be reduced by adding suitable viscosity modifiers by adding a corresponding amount to the liquid hardener according to the invention

Viscosity modifier is added. Such liquid hardeners with viscosity-reducing properties are particularly well applicable in infusion or injection procedures. These viscosity modifiers can be added to the liquid hardeners according to the invention without significantly affecting their liquid state. It was particularly surprising here that these modifiers do not adversely affect the latency of the resinous compositions mixed with the liquid hardeners in many cases. Rather, it could also be shown that the latency was increased and thus the shelf life of the resulting resin compositions could be improved.

Thus, according to a further advantageous embodiment, a liquid

Hardener composition of the present invention which comprises, in addition to a) cyanamide, b) at least one urea derivative of the formula (I), (V) and / or (VII), c) at least one curing accelerator from the class of the amines according to formula (II) , furthermore d) at least one viscosity modifier selected from the group of mono-, di- and polyols, ethers, polyethers and polyether polyols, ketones, aldehydes, nitriles,

Carboxylic acid esters or mixtures thereof. Particularly preferred are liquid hardener compositions comprising a viscosity modifier from the listed group, which in turn has a boiling point of at least 100 ° C. These

Modifiers remain in the curing in the moldings to be produced and are preferably incorporated into the polymer matrix or crosslink this polymer matrix additionally.

As particularly effective viscosity modifiers have this

Viscosity modifiers from the group of mono-, di- and polyols, ethers, ether alcohols, Polyethers, polyether polyols or mixtures thereof, in particular those which in turn have a boiling point of at least 100 ° C.

In a particularly preferred embodiment, a liquid hardener composition comprises at least one viscosity modifier selected from the group of mono-, di- and polyols, ethers, polyethers, ether alcohols and polyether polyols or mixtures thereof according to general formula (IX)

Formula (IX) where the radicals are the same or independent of each other:

R ^{1 1,} R ²² = the same or independently hydrogen, -OH or C1 to C15 alkyl;

R ¹² , R ¹⁴ , R ¹⁶ , R ¹⁸ , R ²⁰ = simultaneously or independently of one another are hydrogen, -OH or C 1 - to C 5 -alkyl;

R ³ , R ¹⁵ , R ¹⁷ , R ¹⁹ , R ²¹ = simultaneously or independently of one another hydrogen,

-OH, -NH ₂ or C 1 to C 5 alkyl;

With

m, n, o, s, p, q, t = simultaneously or independently of one another a number from 0 to

10, in particular from 0 to 5; and in which

i) m, s, u = simultaneously or independently of one another a number from 1 to

10, in particular from 1 to 5; and or

ii) p, t, u = simultaneously or independently of one another a number from 1 to

10, in particular from 1 to 5.

Monoalcohols from the group of C 2 - to C 10 -amino alcohols and C 6 - to C 12 -alcohols, in particular -hexanol, 1-heptanol,

Octanol, 1-nonanol, 1-decanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol,

2-aminoethanol, 3-aminopropanol, 4-aminobutanol, 5-aminopentanol, 6-aminohexanol, 7-aminoheptanol, 8-aminooctanol, 9-aminononanol, 10-aminodecanol, or mixtures thereof containing dialcohols from the group of C2 to C12 Alcohols, in particular

Ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol or mixtures thereof, the trialcohols from the group of C3 to C12 alcohols, in particular 1, 2,3-propanetriol, 1, 2,3-butanetriol, 1, 2,3-pentanetriol, 1, 2,3-hexanetriol, 1, 2,4-hexanetriol, 1, 2,6-hexanetriol or mixtures thereof , the aldehydes from the group of the C6 to C12 aldehydes, in particular hexanal, heptanal, octanal, nonanal, decanal or mixtures thereof, the ketones, in particular 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, 2- Heptanone, 3-heptanone, 2-octanone, 3-octanone or mixtures thereof, the ethers, nitriles, polyethers, ether alcohols or polyether polyols from the group dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecanyl ether, methoxy and ethoxy alcohols, methoxy and ethoxydialcohols, polyethylene glycols, polypropylene glycols, polyethylene propylene glycols, polyethylene glycol monoalkyl ethers, in particular

Polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether, ethylhexyl ether, ethylheptyl ether, ethyloctyl ether, ethylnonyl ether, ethyldecanyl ether, benzonitrile, acetonitrile, or mixtures thereof.

According to a further advantageous embodiment is thus also a liquid

A curative composition for the curing of curable polymer resins. The present invention, which comprises a) cyanamide, b) at least one urea derivative of the formula (I), (V) and / or (VII), c) at least one curing accelerator from the class of the amines according to formula ( II) and d) a viscosity modifier, in particular a

Viscosity modifier according to formula (IX) comprises, in particular contains, wherein the liquid hardener composition preferably cyanamide and at least one urea derivative of formula (I), (V) or (VII) in a molar ratio of cyanamide: urea derivative or urea derivative mixture from 1: 1 to 4: 1 includes.

In the presence of at least one viscosity modifier, the molar ratios of cyanamide urea derivative may also be outside the preferred range of 1: 1 to 4: 1. For example, molar ratios of cyanamide: urea derivative of 0, 1 to <1: 1, in particular from 0.2 to <1: 1, possible, but also molar ratios of cyanamide: urea derivative of> 4: 1 to 20: 1, in particular > 4: 1 to 10: 1.

Furthermore, it has surprisingly been found that a particularly high latency and thus high storage stability of the hardener composition itself as well as of epoxy resin compositions comprising this hardener composition can be adjusted if the hardener composition is further added to a stabilizer from the group of inorganic or organic acids , By adding stabilizers from the group of inorganic or organic acids, the storage stability could be doubled, in some cases even tripled. At the same time the excellent curing properties, such as the high Reactivity at the curing temperature, compared to the hardeners without stabilizers maintained.

Thus, according to another embodiment, the present invention also encompasses a liquid hardener composition which preferably further comprises e) a stabilizer selected from the group of inorganic or organic acids.

As stabilizers in particular organic acids from the group of aromatic and non-aromatic carboxylic acids, dicarboxylic acids or tricarboxylic acids have been found particularly suitable. Also preferred as organic acids or as aromatic and non-aromatic carboxylic acids, dicarboxylic acids or tricarboxylic acids are acids from the group of formic acid, acetic acid, propionic acid, maleic acid, malonic acid, salicylic acid, lactic acid, citric acid, oxalic acid, adipic acid, benzoic acid, phthalic acid, alkyl sulfonic acids, arylsulfonic acids , in particular toluenesulfonic acid, or their anhydrides are used.

However, it can also be provided that hardener compositions according to the invention as stabilizer inorganic acids selected from the group of hydrochloric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, ortho-phosphoric acid,

Diphosphoric acid, triphosphoric acid, polyphosphoric acid, nitric acid or their

Anhydrides include. Thus, a liquid hardener composition is the subject of the present invention which comprises as stabilizer an inorganic or organic acid from the group of salicylic acid, phthalic acid, toluenesulfonic acid, sulfuric acid, phosphoric acid or their anhydrides or mixtures thereof.

According to a further advantageous embodiment is thus also a liquid

The present invention provides a) cyanamide, b) at least one urea derivative of the formula (I), c) at least one curing accelerator from the class of the amines according to formula (II), d) optionally a viscosity modifier and e ) at least one stabilizer selected from the group of organic acids, in particular aromatic and non-aromatic carboxylic acids, dicarboxylic acids or tricarboxylic acids, or inorganic acids, in particular inorganic acids selected from the group of hydrochloric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, ortho-phosphoric acid,

Anhydrides comprises, in particular contains, wherein the liquid hardener in particular cyanamide and at least one urea derivative of formula (I), (V) or (VII) in a molar ratio of cyanamide: urea derivative or urea derivative mixture of from 1: 1 to 4: 1.

In the presence of at least one stabilizer, the molar ratios of

Cyanamide: H substance derivative also outside the preferred range of 1: 1 to 4: 1. For example, molar ratios of cyanamide: urea derivative of 0.1 to <1: 1, in particular from 0.2 to <1: 1, possible, but also molar ratios of cyanamide: urea derivative of> 4: 1 to 20: 1, in particular > 4: 1 to 10: 1.

Particular preference is given to those acids, in particular inorganic acids, which have a water content of less than 20% by weight (based on the acid). Very particular preference is given to those acids, in particular inorganic acids, which have a water content of less than 15% by weight, more preferably less than 10% by weight and very particularly less than 5% by weight (in each case based on the acid) , Thus, liquid hardeners can be provided, which in turn are liquid and solvent-free in the sense of the present invention.

According to a particularly preferred embodiment of the present invention contains a liquid hardener composition

a) 1 to 50 parts by weight of cyanamide,

b) 1 to 50 parts by weight of at least one urea derivative of the formula (I),

(V), and / or (VII),

c) 0.01 to 50 parts by weight of at least one curing accelerator from the

Class of amines according to formula (II),

d) 0 to 50 parts by weight of at least one viscose od od i kato r.

e) 0 to 10 parts by weight of at least one stabilizer.

In a further development of the present invention are also epoxy resin compositions comprising a) at least one curable epoxy resin and b) at least one liquid

A hardener composition according to the above-described kind, and polyurethane resin compositions comprising a) at least one curable polyurethane resin and b) at least one liquid hardener composition according to the type described above, the subject of the present invention.

With respect to the epoxy resins to be cured, the present invention is not limited. There are in particular all commercially available products in question, which usually have more than one 1, 2-epoxide group (oxirane) and thereby saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic.

In addition, the epoxy resins may have substituents such as halogens, phosphorus and hydroxyl groups. 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) -based epoxy resins and the bromine-substituted derivative (tetrabromobisphenol A), glycidyl polyethers of 2,2-bis (4-hydroxyphenyl) methane (bisphenol F) and Glycidyl polyethers of novolaks and of aniline or substituted anilines, such as, for example, p-aminophenol or 4,4'-diaminodiphenylmethane, can be obtained by using

hardener composition according to the invention are hardened particularly well.

The amount of use of the liquid hardener compositions according to the invention is not subject to any restrictions. Preferably, however, to 100 parts of resin, in particular curable epoxy resin or curable polyurethane resin, 0.01 to 15 parts are used, preferably 0, 1 to 15 parts, preferably 0.1 to 10 parts and most preferably 1 to 10 parts (in each case based on the weight). A combination of several liquid hardeners according to the invention or a combination of liquid hardeners according to the invention with further co-hardeners is also covered by this invention.

The curing of the epoxy resins using the inventively used

Hardener compositions usually take place at temperatures from 80 ° C. The choice of curing temperature depends on the specific processing and

Product requirement and can be varied on the formulation, especially by regulating the amounts and by adding other additives. It is irrelevant in which way the resin formulations energy is supplied. For example, this can be done in the form of heat through an oven or heating elements, but also by means of infrared radiators or excitation by microwaves or other radiation.

By adding further commercially available additives, as are known to the person skilled in the art for curing epoxy resins, the curing profile of the formulations according to the invention can be varied.

Additives for improving the processability of the uncured epoxy resin compositions or the uncured polyurethane compositions or additives for adapting the thermo-mechanical properties of the thereof

produced thermoset products to the requirement profile include, for example, reactive diluents, fillers, rheology additives such as thixotropic agents or

Dispersing additives, defoamer, dyes, pigments, toughening modifiers,

Impact improvers or fire protection additives. Epoxy resin formulations with the hardener compositions according to the invention are suitable for both manual and mechanical processing methods and in particular for the production of impregnated reinforcing fibers and composites, as described, inter alia, in the writings of GW Ehrenstein, Faserverbund-Kunststoffe, 2006, 2nd edition, Carl Hanser Verlag , Munich, chapter 5, page 148ff, and M. Reyne, Composite Solutions, 2006, JEC Publications, chapter 5, page 51ff. In addition to use in prepreg processes, handling in infusion and injection processes is a preferred form of processing. Here, the generally very good miscibilities of the liquid hardener according to the invention in the epoxy resins are advantageous because of the

Impregnation process flowable infusion resins with low viscosity are required (see, inter alia, M. Reyne, Composite Solutions, 2006, JEC Publications, Chapter 5, page 65 and GW Ehrenstein, fiber reinforced plastics, 2006, 2nd edition, Carl Hanser Verlag, Munich, Chapter 5, page 166).

This is also a composite material comprising a) a carrier material, in particular a fiber material, b) at least one curable epoxy resin and / or curable polyurethane resin and c) at least one liquid hardener composition of the type described above, the subject of the invention.

Thus, the use of liquid hardener compositions of the type described above for curing curable compositions is also an object of the present invention. In particular, this use is directed to compositions comprising at least one curable epoxy resin and / or a curable polyurethane resin.

Furthermore, the present invention also encompasses the use of liquid hardeners of the type described above for curing impregnated fiber materials or impregnated fabrics, knits or braids.

Due to the favorable application properties of the liquid hardener according to the invention and its low dosage, an advantageous cost-benefit ratio is achieved, with which these hardeners are particularly well suited for industrial application.

The following examples are intended to explain the invention in more detail. Examples

1) Raw materials used:

E 828 LVEL epoxy resin Epikote 828 LVEL - Momentive

Liquid Hardener DYHARD Fluid 1 11, AlzChem AG

Accelerator B1 isophoronediamine, Vestamin IPD - Evonik AG

Accelerator B2 Amidoamine, EPICURE Curing Agent 3055 - Momentive

Accelerator B3 Diethylenetriamine, Epikure 3223 - Momentive

Accelerator B4 Triethylenetetramine, Aradur HY951 - Huntsman

Accelerator B5 2,2'-dimethyl-4,4'methylenebis (cyclohexylamine), Aradur 8615 - Huntsman

Example 1-5

Composition Standard _{Hz 1 H} Z 2 HZ 3 HZ 4 HZ 5 mol: mol

Liquid Hardener 1 1 1 1 1 1

Accelerator B1 0,0015

Accelerator B2 0.0005

Accelerator B3 0,002

Accelerator B4 0,0016

Accelerator B5 0,001 1

Dynamic DSC: Measurement on Mettler Toledo DSC 822

Heating from 30 ° C to 250 ° C at 10 K / min

Isothermal DSC: Measurement on Mettler Toledo DSC 822

Keep at 120 ° C for 120 minutes.

Tg: Measurement on Mettler Toledo DSC 822

Heating from 30 ° C to 200 ° C at 29 K / min

Keep at 200 ° C for 10 minutes

Cooling from 200 ° C to 50 ° C at 20 K / min

Keep at 50 ° C for 5 min

Heating from 50 ° C to 200 ° C at 20 K / min Hold for 10 min at 200X

Cooling from 200 ° C to 50 ° C at 20 K / min

Keep at 50 ° C for 5 min

Heating from 50 ° C to 200 ° C at 20 K / min

Shelf life of the epoxy resin composition in days after storage at 23 ° C in a climatic chamber.

Latency definition is the time after which the viscosity of the epoxy resin composition has doubled.

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2 HZ 1 HZ 2

Dynamic DSC

Onset temperature (X) 144 132 127

Peak temperature (° C) 152 145 143

Reaction enthalpy (J / g) 239 215 242

Isothermal DSC at 120X

Time to Peak (min: sec) 09:20 01: 45 04:00

Time to 90% conversion (min) 61 48 54

Tg (X), DSC 1 19 1 15 120

Latency @ 23X (days) 45 8 5

The results clearly show that the accelerators have a great influence on the cure rate. The onset temperatures are significantly lower and the reaction times at 120X much shorter. Despite this faster cure, a sufficiently long latency of several days remains.

Claims

claims

A liquid hardener composition for curing polymer resins, comprising a) cyanamide,

b) at least one urea derivative of the formula (I)

Formula (I) where R ¹ , R ² , R ^{3 is the} same or independent of one another and at least one R ¹ , R ² or R ^{3 is} other than hydrogen:

R ¹ , R ² = simultaneously or independently of one another hydrogen, C 1 - to C 15 -alkyl, C 3 - to C 15 -cycloalkyl or

together C2 to C10 alkylene;

R ³ = hydrogen, C 1 - to C 15 -alkyl, C 3 - to C 15 -cycloalkyl, aryl, arylalkyl, with -NHC (O) NR R ² substituted C ¹ - to C 15 -alkyl, with -NHC (O) NR ¹ R ² substituted C3 to C15 cycloalkyl,

with -NHC (0) NR ¹ R ² substituted aryl or

with -NHC (O) NR ¹ R ² substituted arylalkyl; and c) at least one curing accelerator from the class of the amines according to formula (II)

N

I

R ⁵² formula (II) where R ⁵⁰ , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ^{57 are the} same or independent and at least one radical R ⁵⁰ , R ⁵¹ or R ⁵² is different from hydrogen: R ⁵⁰ , R ⁵¹ , R ⁵² = simultaneously or independently

Hydrogen,

C1 to C10 alkyl,

Aminoalkyl with - [(R ⁵⁶ ) -N (R ⁵³ )] _n - (R ⁵⁴ ),

Amidoalkyl - [(R ⁵⁷ ) -NHC (O)] _m - (R ⁵⁵ ) or

Alkylcarbonyl with -C (O) -R ⁵⁵ ;

R ⁵³ , R ⁵⁴ = simultaneously or independently

Hydrogen,

Alkylcarbonyl with -C (0) -R ⁵⁵ or

C1 to C10 alkyl;

R ⁵⁵ = C 1 - to C 10 -alkyl or C 2 - to C 20 -alkenyl;

R ⁵⁶ , R ⁵⁷ = simultaneously or independently

C1 to C10 alkylene or

C3 to C15 cycloalkylene;

n, m = simultaneously or independently of one another an integer from 1 to 10.

2. hardener composition according to claim 1, characterized in that the

Cyanamide hardener composition and at least one urea derivative of the formula (I) in a molar ratio of cyanamide: urea derivative or urea derivative mixture of 1: 1 to 4: 1.

3. hardener composition according to claim 1 or 2, characterized in that the hardener composition comprises a urea derivative of the formula (I), wherein for the radical R ³ = aryl, arylalkyl, with -NHC (0) NR R ² substituted aryl or with -NHC ( 0) NR ¹ R ² substituted arylalkyl is a radical of the general formula (V)

Formula (V) where the radicals R ¹ , R ^{2 have} the abovementioned meaning and for the other radicals simultaneously or independently of one another: R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ = hydrogen, halogen, C 1 - to C 15 -alkyl, C ³ - to C 15 -cycloalkyl,

Aryl, arylalkyl, -CF ₃ , -NHC (O) NR R ² ,

with -NHC (0) NR ¹ R ² substituted C 1 to C 15 -alkyl,

with -NHC (0) NR ¹ R ² substituted aryl or

with -NHC (O) NR R ² substituted arylalkyl;

R ⁹ , R ¹⁰ = simultaneously or independently of one another hydrogen or

C1 to C5 alkyl;

n = a number between 0 and 10.

4. hardener composition according to at least one of the preceding claims

characterized in that the hardener composition comprises a urea derivative of the formula (I), where the radicals simultaneously or independently of one another are:

R ¹ , R ² = simultaneously or independently of one another hydrogen or

C1 to C15 alkyl;

R ³ = hydrogen, C 1 - to C 15 -alkyl, C ³ - to C 15 -cycloalkyl,

with -NHC (O) NR R ² substituted C ¹ - to C 15 -alkyl or C 3 - to C 15 -cycloalkyl substituted by -NHC (O) NR ¹ R ² .

5. hardener composition according to at least one of the preceding claims

characterized in that the hardener composition is a urea derivative according to formula (I) selected from the group 1 -methylurea, 1, 1-dimethylurea, 1, 3-dimethylurea, 3- (3-chloro-4-methylphenyl) -1, 1-dimethylurea , 3- (p-Chlorophenyl) -1, 1-dimethylurea, 3-phenyl-1, 1-dimethylurea, 3- (3,4-dichlorophenyl) -1, 1-dimethylurea, 1, 1 '- (methylenedi-p -phenylene) -bis- (3,3-dimethylurea), 3- (3-trifluoromethylphenyl) -1, 1-dimethylurea, 1,1 '- (2-methyl-m-phenylene) -bis (3,3 -dimethylurea) and / or 1, 1 '- (4-methyl-m-phenylene) bis- (3,3-dimethylurea).

6. hardener composition according to at least one of the preceding claims

characterized in that the hardener composition is a

Hardening accelerator from the group diethylenetriamine, triethylenetetramine,

Isophoronediamine and / or 2,2'-dimethyl-4,4'methylene-bis-cyclohexylamine.

7. hardener composition according to at least one of the preceding claims

characterized in that the hardener composition furthermore comprises d) at least one viscosity modifier selected from the group of mono-, di- and polyols, Ethers, ether alcohols, polyethers and polyether polyols, ketones, aldehydes, nitriles, carboxylic acid esters or mixtures thereof.

8. hardener composition according to at least one of the preceding claims

characterized in that the hardener composition further comprises e) a

Stabilizer selected from the group comprising inorganic or organic acids.

9. hardener composition according to at least one of the preceding claims

characterized in that the stabilizer comprises an inorganic or organic acid from the group of salicylic acid, phthalic acid, toluenesulfonic acid, sulfuric acid, phosphoric acid or their anhydrides or mixtures thereof.

10. comprising epoxy resin composition

a) at least one curable epoxy resin and

b) at least one liquid hardener composition according to at least one of the preceding claims 1 to 9.

1 1. polyurethane resin composition comprising

a) at least one curable polyurethane resin and

12. comprising composite material

a) a carrier material, in particular a fiber material,

b) at least one curable epoxy resin and / or curable polyurethane resin and c) at least one liquid hardener composition according to at least one of the preceding claims 1 to 9.

13. Use of a liquid hardener composition according to at least one of the preceding claims 1 to 9 for curing curable polymer resins, in particular curable epoxy resins, curable polyurethane resins or mixtures thereof, or for curing with curable polymer resins, in particular epoxy resins, impregnated fiber materials, impregnated fabrics, impregnated knitted or impregnated braids.