FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules  2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. "" LOW-VISCOSITY EPOXY RESIN COMPOSITION WITH LOW BLUSHING ""

2.

1. (A) SIKA TECHNOLOGY AG
(B) Switzerland
(C) Zugerstrasse 50 CH-6340 Baar Switzerland

The following specification particularly describes the invention and the manner in which it is to be performed.

Technical field
The invention relates to the field of epoxy resin compositions and to their uses  particularly as coatings  floor covers  and paint finishes.

Prior art
Two-component epoxy resin compositions and their use as coatings are known. They usually consist of a resin component which comprises an epoxy resin  and of a hardener component which comprises compounds that are reactive with epoxy groups  usually primarily polyamines. The two components are mixed for use  and they cure at ambient temperature. The systems according to the prior art have several properties that are disadvantageous in practice.
Epoxy resins  particularly the most widespread types which are based on bisphenols  are viscous fluids or solids. For use in two-component epoxy resin compositions for coatings  they are usually diluted to achieve a good miscibility of the two components  and a good processability at ambient temperatures. For the dilution  low-viscosity epoxies  so-called epoxy reactive diluents  are used in many cases. However  they are expensive  they often have a strong irritating effect  and they can lower the strength of the cured system in an undesired manner. The epoxy resins can also be diluted with organic solvents. However  the latter are usually volatile organic compounds (VOC; Volatile Organic Compound) which  during and after the processing of the epoxy resin composition  enter into the atmosphere due to evaporation  and represent a hazard for humans and for the environment  because they are often highly flammable  they cause odor emissions  and they are capable of causing nausea  injuries to health  and environmental damage.
The polyamines that are usually used as hardeners present  due to their content of primary amino groups  the great disadvantage that they are capable of forming stable carbonate and carbamate salts  with gaseous carbon dioxide (CO2) from the air in combination with moisture. Hardeners that are based on such polyamines can therefore usually not be stored open in the air  because crusts form as a rule on the container. On the other hand  such hardeners  even when they are used in a coating — after mixing in the epoxy resin and during the curing — are capable of taking up CO2  which results in undesired effects  such as a tacky surface with tarnishing or spotting  and even incomplete curing. These effects are referred to as "blushing" by the person skilled in the art. To suppress crust formation and blushing  and at the same time to achieve dilution  epoxy resin compositions are often mixed with considerable quantities of benzyl alcohol  which  however  results again in disadvantages. Although benzyl alcohol is relatively free of odors and presents low volatility  it is nonetheless a VOC  and consequently benzyl alcohol-containing composition cannot be declared to be VOC-free. Epoxy resin compositions having a high content of benzyl alcohol  moreover  tend to form bubbles  particularly on porous substrates  they have a reduced resistance to abrasion  and they perform poorly in emission tests in interior spaces. Alkyl phenols  such as nonyl phenol  are also used to suppress blushing  but they are problematic for reasons pertaining to toxicity.
In general  secondary amino groups do not undergo a spontaneous reaction with CO2  or their carbonates and carbamates are not stable. Polyamines having primarily secondary amino groups therefore lead to little blushing in epoxy resin compositions. However  polyamines comprising only secondary amino groups are rarely used  because they are usually expensive to produce  and lead to long curing times. On the other hand  polyamines with adducted diepoxies  as well as so-called polyamidoamines  are often used. Both comprise besides primarily secondary amino groups also primary amino groups  and they exhibit little blushing; however their viscosity is usually so high that they have to be diluted  which again entails the mentioned disadvantages.

Description of the invention
The aim of the present invention therefore is to provide two-component epoxy resin compositions whose resin component presents a highly manageable viscosity  and which present few blushing effects in areal application  and cure to coatings of good quality.
It has now been found surprisingly that two-component epoxy resin compositions according to Claim 1 achieve this aim. On the one hand  the viscosity of the resin component is surprisingly low  since the aldehyde is surprisingly very compatible with the epoxy resin  and dilutes the latter well  particularly if the aldehyde is liquid at room temperature. On the other hand  using the composition according to the invention  even in areal application  few blushing effects occur  since the aldehyde reduces the content of primary amino groups during the mixing of the components by chemical reaction until they no longer react observably with CO2. In the process  the aldehyde is bound covalently in the composition. During the curing  substantially clear  glossy and nonadhesive films having excellent mechanical properties are produced. The invention consequently makes possible  in particular  high-quality epoxy resin coatings that comprise no or a clearly reduced content of VOC and epoxy reactive diluents.
Additional advantageous embodiments of the invention are the subject matter of additional independent and dependent claims.

Ways of carrying out the invention
The subject matter of the invention is a two-component epoxy resin composition consisting of
a resin component K1 which comprises at least one epoxy resin and at least one aldehyde  and
a hardener component K2 which comprises at least one polyamine A1 having at least one primary amino group.
The resin component K1 preferably has an aldehyde content of at least 1 wt%  preferably at least 3 wt%.
The two-component epoxy resin composition is particularly suitable as a coating.
In the present document  substance names starting with "poly " such as  polyamine  polyol or polyepoxy denote substances that according to the formula contain two or more of the functional groups occurring in their name per molecule. Compounds having two epoxy groups are referred to as "diepoxy."
The structural element

is referred to as "epoxy group" in the present document.
The broken lines in the formulas in this document in each case represent the bond between a substituent and the associated molecule residue.
The term "glycidyl ether" in the present document denotes an ether of 2 3-epoxy-1-propanol (glycidol).
The abbreviation "EEW" in the present document stands for "epoxy equivalent weight."
In the present document  the term "primary" amino group denotes an NH2 group which is bound to an organic residue  and the term "secondary" amino group denotes an NH group which is bound to two organic residues which together can also be part of a ring.
"Room temperature" in the present document denotes a temperature of 23 °C.
The term "diluting" in the present document denotes the lowering of the viscosity of a liquid.
The boldface designations  such as  K1  K2  A1  A2  ALD or the like  are used in the present document only to improve the readability and for identification.
The resin component K1 of the two-component epoxy resin composition comprises at least one epoxy resin.
Suitable epoxy resins are the epoxy resins conventionally used in epoxy chemistry. They are obtained in the known manner  for example  from the oxidation of the corresponding olefins or from the reaction of epichlorohydrin with the corresponding polyols  polyphenols or amines.
So-called polyepoxy liquid resins  hereafter referred to as "liquid resin " are particularly suitable as epoxy resin. They have a glass transition temperature that is usually less than 25 °C  in contrast to the so-called solid resins which have a glass transition temperature above 25 °C  and which can be comminuted at 25 °C to pourable powders.
In an embodiment  the liquid resin is an aromatic polyepoxy. For this purpose  suitable liquid resins have the formula (I)

where R"" and R"  independently of each other  in each case stand for a hydrogen atom or for a methyl group  and s on average stands for a value from 0 to 1. Preferred liquid resins of formula (I) are those in which the index s on average has a value of less than 0.2.
The liquid resins of formula (I) are diglycidyl ethers of bisphenol A  bisphenol F and bisphenol A/F  where A stands for acetone and F for formaldehyde  which are used as educts for the preparation of these bisphenols. A bisphenol A liquid resin accordingly comprises methyl groups  a bisphenol F liquid resin comprises hydrogen atoms  and a bisphenol A/F liquid resin comprises both methyl groups and also hydrocarbon atoms as R"" and R" in formula (I). In the case of bisphenol F  positional isomers can also be present  particularly those derived from 2 4""- and 2 2""-hydroxyphenylmethane.
Additional suitable aromatic liquid resins are the glycidylization products of
- dihydroxybenzene derivatives  such as  resorcinol  hydroquinone and catechol;
- additional bisphenols or polyphenols  such as  bis-(4-hydroxy-3-methylphenyl)-methane  2 2-bis-(4-hydroxy-3-methylyphenyl)-propane (bisphenol C)  bis-(3 5-dimethyl-4-hydroxyphenyl)-methane  2 2-bis-(3 5-dimethyl-4-hydroxyphenyl)-propane  2 2-bis-(3 5-dibromo-4-hydroxyphenyl)-propane  2 2-bis-(4-hydroxy-3-tert.-butylphenyl)-propane  2 2-bis-(4-hydroxyphenyl)-butane (bisphenol B)  3 3-bis-(4-hydroxyphenyl)-pentane  3 4-bis-(4-hydroxyphenyl)-hexane  4 4-bis-(4-hydroxyphenyl)-heptane  2 4-bis-(4-hydroxyphenyl)-2-methylbutane  2 4-bis-(3 5-dimethyl-4-hydroxyphenyl)-2-methylbutane  1 1-bis-(4-hydroxyphenyl)-cyclohexane (bisphenol Z)  1 1-bis-(4-hydroxyphenyl)-3 3 5-trimethylcyclohexane (bisphenol TMC)  1 1-bis-(4-hydroxyphenyl)-1-phenylethane  1 4-bis[2-(4-hydroxyphenyl)-2-propyl]-benzene) (bisphenol P)  1 3-bis-[2-(4-hydroxyphenyl)-2-propyl]-benzene) (bisphenol M)  4 4""-dihydroxydiphenyl (DOD)  4 4""-dihydroxybenzophenone  bis-(2-hydroxynaphth-1-yl)-methane  bis-(4-hydroxynaphth-1-yl)-methane 1 5-dihydroxy-naphthalene  tris-(4-hydroxyphenyl)-methane  1 1 2 2-tetrakis-(4-hydroxyphenyl)-ethane bis-(4-hydroxyphenyl)-ether  bis-(4-hydroxyphenyl)sulfone;
- condensation products of phenols with formaldehyde  which are obtained under acidic conditions  such as  phenol novolaquers or cresol novolacquers  also referred to as bisphenol F novolacquers;
- aromatic amines  such as  aniline  toluidine  4-aminophenol  4 4""-methylenediphenyldiamine (MDA)  4 4""-methylenediphenyldi(N-methyl)-amine  4 4""-[1 4-phenylene-bis-(1-methylethylidene)]-bisaniline (bisaniline P)  and 4 4""-[1 3-phenylene-bis-(1-methylethylidene)]-bisaniline (bisaniline M).
Also suitable  as epoxy resin  is an aliphatic or cycloaliphatic polyepoxy  such as  for example
- a glycidyl ether of a saturated or unsaturated  branched or unbranched  cyclic or open-chained C2-C30 diol  such as  for example  ethylene glycol  propylene glycol  butylene glycol  hexanediol  octanediol  a polypropylene glycol  dimethylolcyclohexane  neopentyl glycol or dibromoneopentyl glycol;
- a glycidyl ether of a tri- or tetrafunctional  saturated or unsaturated  branched or unbranched  cyclic or open-chained polyol  such as  castor bean oil  trimethylolpropane  trimethylolethane  pentaerythrol  sorbitol or glycerol  as well as alkoxylated glycerol or alkoxylated trimethylolpropane;
- a hydrated bisphenol A  F or A/F liquid resin  or the glycidylization products of hydrated bisphenol A  F or A/F; and
- an N-glycidyl derivative of amides or heterocyclic nitrogen bases  such as  triglycidyl cyanurate and triglycidyl isocyanurate  as well as reaction products of epichlorohydrin and hydantoin.
Additional possible epoxy resins are bisphenol A  F or A/F solid resin whose structure is similar to that of the already mentioned liquid resins of formula (I)  except that the index s has a value of 2-12  and the glass transition temperature is higher than 25 °C.
Finally  as epoxy resin  it is also suitable to use epoxy resins from the oxidation of olefins  for example  from the oxidation of vinylcylohexene  dicyclopentadiene  cyclohexadiene  cyclododecadiene  cyclododecatriene  isoprene  1 5-hexadiene  butadiene  polybutadiene or divinylbenzene.
As epoxy resin  it is preferable to use liquid resins based on a bisphenol  particularly based on bisphenol A  bisphenol F or bisphenol A/F  which are commercially available  for example  from Dow  Huntsman  and Hexion  wherein said liquid resins are optionally present in combination with bisphenol A solid resin or bisphenol F novolacquer epoxy resin.
The epoxy resin can comprise a reactive diluent  particularly an epoxy reactive diluent. Suitable as epoxy reactive diluents are low-viscosity mono- and polyepoxies  such as  for example  the glycidyl ethers of monovalent or polyvalent phenols  and aliphatic or cycloaliphatic phenols  such as particularly the already mentioned polyglycidyl ethers of di- or polyols  as well as moreover particularly phenyl glycidyl ether  cresyl glycidyl ether  p-n-butylphenyl glycidyl ether  p-tert-butylphenyl glycidyl ether  nonylphenyl glycidyl ether  allyl glycidyl ether  butyl glycidyl ether  hexyl glycidyl ether  2-ethylhexyl glycidyl ether  as well as glycidyl ethers of natural alcohols  such as  for example  C8-C10 alkyl glycidyl ethers or C12-C14 alkyl glycidyl ethers. The addition of a reactive diluent to the epoxy resin results in a reduction of the viscosity  as well as — in the cured state of the epoxy resin composition — a reduction of the glass transition temperature and of the mechanical values.
The resin component K1 comprises preferably only a low content of epoxy reactive diluent  or in particular it is free of epoxy reactive diluent.
The resin component K1 of the two-component epoxy resin composition moreover comprises at least one aldehyde.
Particularly suitable aldehydes  on the one hand  are aldehydes that are liquid at room temperature  particularly propanol  2-methylpropanal  butanal  2-methylbutanal  2-ethylbutanal  pentanal  pivalaldehyde  2-methylpentanal  3-methylpentanal  4-methylpentanal  2 3-dimethylpentanal  hexanal  2-ethylhexanal  heptanal  octanal  nonanal  decanal  undecanal  2-methylundecanal  dodecanal  methoxyacetaldehyde  cyclopropanecarboxaldehyde  cyclopentanecarboxaldehyde  cyclohexanecarboxaldehyde  2 2-dimethyl-3-phenylpropanal; 1-naphthaldehyde  benzaldehyde or substituted benzaldehydes  particularly the isomeric tolualdehydes  salicylaldehyde  and m-phenoxybenzaldehyde; and cinnamic aldehyde.
On the other hand  as aldehyde  aldehydes of formula (II) are particularly suitable.

In formula (II) 
R1 and R2
in each case stand  independently of each other  either for a monovalent hydrocarbon residue having 1-12 C atoms 
or together for a bivalent hydrocarbon residue having 4-12 C atoms  which is part of an optionally substituted carbocyclic ring having 5-8  preferably 6 C atoms;
R3 stands for a hydrogen atom or for an arylalkyl or cycloalkyl or alkyl group having 1-12 C atoms  particularly for a hydrogen atom; and
Z stands for an ester  ether  tertiary amino or amido group having up to 31 C atoms  which groups optionally comprise additional ether oxygens.
R1 and R2 preferably stand in each case for a methyl residue.
R3 preferably stands for a hydrogen atom.
Z preferably stands for a residue of formula (III) or (IV) 

where
R5
stands either for a hydrogen atom 
or for a linear or branched alkyl residue having 1-30 C atoms  optionally with cyclic portions  and optionally with at least one heteroatom  particularly oxygen in the form of ether  carbonyl or ester groups 
or for a singly or multiply unsaturated  linear or branched hydrocarbon residue having 5-30 C atoms 
or for an optionally substituted  aromatic or heteroaromatic  5- or 6-membered ring; and
R9 and R10 
independently of each other  in each case stand either for a monovalent aliphatic  cycloaliphatic or arylaliphatic residue having 1-20 C atoms  which optionally comprises heteroatoms in the form of ether oxygen or tertiary amine nitrogen 
or together they stand for a bivalent aliphatic residue having 3-20 C atoms  which is part of an optionally substituted  heterocyclic ring having 5-8  preferably 6 ring atoms  and comprises  besides the nitrogen atom  optionally additional heteroatoms in the form of ether oxygen or tertiary amine nitrogen.
R5 preferably stands for a linear or branched alkyl residue having 6-30  particularly 11-30 C atoms  optionally with cyclic portions  and optionally with at least one heteroatom  or for a singly or multiply unsaturated  linear or branched hydrocarbon residue having 6-30  particularly 11-30 C atoms.
R5 stands particularly preferably for a linear or branched alkyl residue having 6-30  particularly 11-30 C atoms  optionally with cyclic portions and optionally with at least one heteroatom.
R9 and R10 preferably stand  in each case independently of each other  for a methyl  ethyl  propyl  isopropyl  butyl  isobutyl  2-ethylhexyl  cyclohexyl  benzyl or alkoxyethyl group  or they form together — including the nitrogen atom — a ring  particularly a pyrrolidine  piperidine  morpholine or N-alkylpiperazine ring  wherein said ring is optionally substituted. R9 and R10 stand particularly preferably  in each case independently of each other  for a benzyl or methoxyethyl group  or they form together  including the nitrogen atom  a morpholine ring.
Aldehydes of formula (II) that are liquid at room temperature are preferred.
Most of the mentioned aldehydes are liquid at room temperature. However  it has been found that aldehydes that are solid at room temperature also dilute the resin component K1 very well  provided that the latter is heated to a temperature above the melting point of the aldehyde in question.
Aldehydes of formula (II)  which contain a residue of formula (III) as residue Z  are esters of aliphatic  cycloaliphatic or arylaliphatic 2 2-disubstituted 3-hydroxyaldehydes  such as  in particular  2 2-dimethyl-3-hydroxypropanal  with suitable carboxylic acids  wherein  as carboxylic acids  the following are particularly suited: saturated aliphatic carboxylic acids  such as  in particular  formic acid  acetic acid  propionic acid  butyric acid  isobutyric acid  valeric acid  caproic acid  2-ethylcaproic acid  enanthic acid  caprylic acid  pelargonic acid  capric acid  undecanoic acid  lauric acid  tridecanoic acid  myristic acid  pentadecanoic acid  palmitic acid  heptadecanoic acid  stearic acid  nonadecanoic acid  icosanoic acid; simple unsaturated aliphatic carboxylic acids  such as  palmitoleic acid  oleic acid  erucic acid; multiply unsaturated aliphatic carboxylic acids  such as  linoleic acid  linolenic acid  eleostearic acid  arachidonic acid; cycloaliphatic carboxylic acids  such as cyclohexanoic carboxylic acid; arylaliphatic carboxylic acids  such as  phenylacetic acid; aromatic carboxylic acids  such as  benzoic acid  naphthoic acid  toluic acid  anisic acid; isomers of said acids; fatty acid mixtures from the technical saponification of natural oils and fats  such as  for example  rapeseed oil  sunflower seed oil  linseed oil  olive oil  coconut oil  palm kernel oil  palm oil; as well as dicarboxylic acid monoalkyl and aryl esters  such as those obtained from the simple esterification of dicarboxylic acids  such as  succinic acid  glutaric acid  adipic acid  pimelic acid  octanedioic acid  nonanedioic acid  sebacic acid  1 12-dodecanedioic acid  maleic acid  fumaric acid  hexahydrophthalic acid  hexahydroisophthalic acid  hexahydroterephthalic acid  3 6 9-trioxaundecanedioic acid  and similar derivatives of polyethylene glycol  with alcohols  such as  methanol  ethanol  propanol  butanol  higher homologs and isomers of said alcohols. Carboxylic acids having at least 7 C atoms are preferred  particularly those having 12-31 C atoms  particularly lauric acid  myristic acid  palmitic acid  stearic acid and oleic acid. Lauric acid is particularly preferred.
The aldehyde is preferably selected from the group consisting of 2-ethylbutanal  pentanal  pivalaldehyde  2-methylpentanal  3-methylpentanal  4-methylpentanal  2 3-dimethylpentanal  hexanal  2-ethylhexanal  heptanal  octanal  methoxyacetaldehyde  2 2-dimethyl-3-phenylpropanal  benzaldehyde  1-naphthaldehyde  salicylaldehyde and aldehydes of formula (II)  in particular 3-acetoxy-2 2-dimethylpropanal  2 2-dimethyl-3-lauroyloxypropanal  2 2-dimethyl-3-(N-morpholino)-propanal and 2 2-dimethyl-3-bis-(methoxyethyl)-aminopropanal.
Particularly preferably  the aldehyde is selected from the group consisting of benzaldehyde  salicylaldehyde  2 2-dimethyl-3-phenylpropanal  3-acetoxy-2 2-dimethylpropanal  2 2-dimethyl-3-lauroyloxypropanal  and 2 2-dimethyl-3-(N-morpholino)-propanal.
As aldehyde  it is especially preferable to use the aldehydes of formula (II)  which have a residue of formula (III) as residue Z  wherein R5 comprises 11-30 C atoms  particularly 11-20 C atoms. Such aldehydes are also referred to as ALD aldehydes below. The ALD aldehydes are odorless substances. An "odorless" substance is understood to be a substance which has no odor for most human individuals  that is  it presents no perceivable odor. When using such ALD aldehydes  resin components K1 can be produced that are odorless and VOC-free.
2 2-Dimethyl-3-lauroyloxypropanal is preferred as ALD aldehyde.
The hardener component K2 of the two-component epoxy resin composition comprises at least one polyamine A1 having at least one primary amino group.
The following polyamines are particularly suitable as polyamine A1:
- aliphatic  cycloaliphatic or arylaliphatic primary diamines  for example  ethylenediamine  1 2-propanediamine  1 3-propanediamine  2-methyl-1 2-propanediamine  2 2-dimethyl-1 3-propanediamine  1 3-butanediamine  1 4-butanediamine  1 3-pentanediamine (DAMP)  1 5-pentanediamine  1 5-diamino-2-methylpentane (MPMD)  2-butyl-2-ethyl-1 5-pentanediamine (C11-neodiamine)  1 6-hexanediamine  2 5-dimethyl-1 6-hexanediamine  2 2 4- and 2 4 4-trimethylhexamethylenediamine (TMD)  1 7-heptanediamine  1 8-octanediamine  1 9-nonanediamine  1 10-decanediamine  1 11-undecanediamine  1 12-dodecanediamine  1 2-  1 3- and 1 4-diaminocyclohexane  bis-(4-aminocyclohexyl)-methane (H12-MDA)  bis-(4-amino-3-methylcyclohexyl)-methane  bis-(4-amino-3-ethylcyclohexyl)-methane  bis-(4-amino-3 5-dimethylcyclohexyl)-methane  bis-(4-amino-3-ethyl-5-methylcyclohexyl)-methane (M-MECA)  1-amino-3-aminomethyl-3 5 5-trimethylcyclohexane (= isophoronediamine or IPDA)  2- and 4-methyl-1 3-diaminocyclohexane and mixtures thereof  1 3- and 1 4-bis-(aminomethyl)cyclohexane  2 5(2 6)-bis-(aminomethyl)-bicyclo[2.2.1]heptane (NBDA)  3(4) 8(9)-bis-(aminomethyl)-tricyclo[5.2.1.02 6]decane  1 4-diamino-2 2 6-trimethylcyclohexane (TMCDA)  1 8-menthanediamine  3 9-bis-(3-aminopropyl)-2 4 8 10-tetraoxaspiro[5.5]undecane as well as 1 3- and 1 4-xylylenediamine;
- ether group-containing aliphatic primary diamines  for example  bis-(2-aminoethyl)ether  3 6-dioxaoctane-1 8-diamine  4 7-dioxadecane-1 10-diamine  4 7-dioxadecane-2 9-diamine  4 9-dioxadodecane-1 12-diamine  5 8-dioxadodecane-3 10-diamine  4 7 10-trioxatridecane-1 13-diamine and higher oligomers of said diamines  bis-(3-aminopropyl)polytetrahydrofurans and other polytetrahydrofuran-diamines with molecular weights in the range of  for example  350-2000  as well as polyoxyalkylenediamines. The latter typically represent products from the amination of polyoxyalkylenediols  and they are available  for example  under the name Jeffamine® (from Huntsman)  under the name polyetheramine (from BASF) or under the name PC Amine® (from Nitroil). Particularly suitable polyoxyalkylenediamines are Jeffamine® D-230  Jeffamine® D-400  Jeffamine® D-2000  Jeffamine® XTJ-511  Jeffamine® ED-600  Jeffamine® ED-900  Jeffamine® ED-2003  Jeffamine® XTJ-568  Jeffamine® XTJ-569  Jeffamine® XTJ-523  Jeffamine® XTJ-536  Jeffamine® XTJ-542  Jeffamine® XTJ-559  Jeffamine® EDR-104  Jeffamine® EDR-148  Jeffamine® EDR-176; Polyetheramine D 230  Polyetheramine D 400 and Polyetheramine D 2000  PC Amine® DA 250  PC Amine® DA 400  PC Amine® DA 650 and PC Amine® DA 2000;
- aliphatic  cycloaliphatic or arylaliphatic primary triamines  such as  4-aminomethyl-1 8-octanediamine  1 3 5-tris-(aminomethyl)-benzene  1 3 5-tris-(aminomethyl)-cyclohexane  tris-(2-aminoethyl)-amine  tris-(2-aminopropyl)-amine  and tris-(3-aminopropyl)-amine;
- primary polyoxyalkylene-triamines  which typically are products from the amination of polyoxyalkylenetriols  and are available  for example  under the commercial name Jeffamine® (from Huntsman)  under the name polyetheramine (from BASF) or under the name PC Amine® (from Nitroil)  such as  for example  Jeffamine® T-403  Jeffamine® T-3000  polyetheramine T403 and PC Amine® TA 403;
- tertiary amino group-comprising polyamines  such as  for example  N N""-bis-(aminopropyl)-piperazine  N N-bis-(3-aminopropyl)methylamine  N N-bis-(3-aminopropyl)ethylamine  N N-bis-(3-aminopropyl)propylamine  N N-bis-(3-aminopropyl)cyclohexylamine  N N-bis-(3-aminopropyl)-2-ethylhexylamine  as well as the products of the double cyanoethylation and subsequent reduction of fatty amines which are derived from natural fatty acids  such as  N N-bis-(3-aminopropyl)-dodecylamine and N N-bis-(3-aminopropyl)-talc alkylamine  available as Triameen® Y12D and Triameen® YT (from Akzo Nobel);
- secondary amino group-comprising polyamines  such as  for example  diethylenetriamine (DETA)  dipropylenetriamine (DPTA)  bis-hexamethylenetriamine (BHMT)  3-(2-aminoethyl)aminopropylamine  N3-(3-aminopentyl)-1 3-pentanediamine  N5-(3-aminopropyl)-2-methyl-1 5-pentanediamine  N5-(3-amino-1-ethylpropyl)-2-methyl-1 5-pentanediamine  N N""-dibutylethylenediamine; N N""-di-tert-butyl-ethylenediamine  N N""-diethyl-1 6-hexanediamine  1-(1-methylethyl-amino)-3-(1-methylethyl-aminomethyl)-3 5 5-trimethylcyclohexane (Jefflink® 754 from Huntsman)  N4-cyclohexyl-2-methyl-N2-(2-methylpropyl)-2 4-pentanediamine  N N""-dialkyl-1 3-xylylenediamine  bis-(4-(N-alkylamino)-cyclohexyl)-methane  4 4""-trimethylene-dipiperidine  N-alkylated polyether amines  for example  the Jeffamine® types SD-231  SD-401  SD-404 and SD-2001 (from Huntsman);
- amine/polyepoxy adducts  particularly adducts from the mentioned polyamines with diepoxies in the molar ratio of at least 2/1  particularly in the molar ratio from 2/1 to 6/1;
- as well as polyamidoamines which are reaction products from a monovalent or polyvalent carboxylic acid  or its esters or anhydrides  particularly a dimer fatty acid  and an aliphatic  cycloaliphatic or aromatic polyamine used in stoichiometric excess  particularly a polyalkyleneamine  such as  for example  DETA or triethylenetetramine (TETA)  particularly the commercially available polyamidoamines Versamid® 100  125  140 and 150 (from Cognis)  Aradur® 223  250 and 848 (from Huntsman)  Euretek® 3607  Euretek® 530 (from Huntsman)  Beckopox® EH 651  EH 654  EH 655  EH 661 and EH 663 (from Cytec);
- polyamines A2 having at least one primary and at least two secondary amino groups.
As polyamine A2  the following are particularly suitable:
- aliphatic polyamines comprising two primary and at least two secondary amino groups  for example  so-called polyalkyleneamines  such as  triethylenetetramine (TETA)  tetraethylenepentamine (TEPA)  pentaethylenehexamine (PEHA)  polyethylenepolyamine having 5-7 ethyleneamine units (the so-called "higher ethylenepolyamine " HEPA) and N N""-bis(3-aminopropyl)ethylenediamine. Such polyalkyleneamines are prepared  for example  from 1 2-dichloroethane and ammonia  or by cyanoethylation or cyanobutylation followed by hydration of primary polyamines;
- so-called polyethyleneimines (PEI); they are branched polymer amines from the polymerization of ethyleneimine. An appropriate polyethyleneimine typically has an average molecular weight in the range of 250-25 000 g/mol  and it comprises tertiary  secondary and primary amino groups. Polyethyleneimines are available  for example  under the trade names Lupasol® (from BASF)  for example the types Lupasol® FG  Lupasol® G20 and Lupasol® PR 8515;
- amine/polyepoxy adducts which comprise at least one primary and at least two secondary amino groups  particularly the adducts of polyalkyleneamines with diepoxies in the molar ratio of at least 2/1  particularly in the molar ratio from 2/1 to 6/1  wherein the following are particularly suitable as polyalkyleneamine: DETA  DPTA  BHMT  3-(2-aminoethyl)aminopropylamine  N3-(3-aminopentyl)-1 3-pentanediamine  N5-(3-aminopropyl)-2-methyl-1 5-pentanediamine  N5-(3-amino-1-ethylpropyl)-2-methyl-1 5-pentanediamine  TETA  TEPA  PEHA  HEPA and N N""-bis(3-aminopropyl)ethylenediamine;
- polyamidoamines which comprise at least one primary and at least two secondary amino groups  such as  for example  the reaction product of a monovalent or polyvalent carboxylic acid  or its esters or anhydrides  and a polyalkyleneamine  such as  for example  DETA or TETA.
As polyamine A1  the polyamines A2 are preferred as well as 1 5-diamino-2-methylpentane (MPMD)  2-butyl-2-ethyl-1 5-pentanediamine (C11-neodiamine)  2 2 4- and 2 4 4-trimethylhexamethylenediamine (TMD)  bis-(4-amino-3-methylcyclohexyl)-methane  1-amino-3-aminomethyl-3 5 5-trimethylcyclohexane (= isophoronediamine or IPDA)  1 3-bis-(aminomethyl)cyclohexane  3(4) 8(9)-bis-(aminomethyl)-tricyclo[5.2.1.02 6]decane  1 3-xylylenediamine  and ether group-containing di- and triamines from the amination of polyoxyalkylene diolenes and triolenes having a molecular weight of 500 g/mol  particularly the commercial types Jeffamine® D-230  Jeffamine® D-400 and Jeffamine® T-403 (from Huntsman).
A particularly preferred polyamine A1 is a polyamine A2 having at least one primary and at least two secondary amino groups.
The polyamine A2 is preferably selected from the group consisting of TETA  TEPA  PEHA  HEPA  N N""-bis(3-aminopropyl)ethylenediamine; adducts of DETA  DPTA  BHMT  TETA  TEPA  PEHA  HEPA or N N""-bis(3-aminopropyl)ethylenediamine with a diglycidyl ether  particularly diglycidyl ether of bisphenol A  bisphenol F  bisphenol A/F  ethylene glycol  propylene glycol  butylene glycol  hexanediol  octanediol or a polypropylene glycol; and polyamidoamines.
Also suitable as polyamine A1 are mixtures of different polyamines  particularly mixtures of at least one polyamine A2 and at least one additional polyamine having at least one primary amino group.
The ratio of the number of aldehyde groups in the resin component K1 to the number of primary amino groups in the hardener component K2 is preferably in the range from 0.1 to 1.1.
For the case where the polyamine A1 comprises only one or no secondary amino group  the ratio of the number of aldehyde groups in the resin component K1 to the number of primary amino groups in the hardener component K2 is preferably in the range from 0.1 to 0.5.
For the case where the polyamine A1 comprises at least two secondary amino groups — that is  it is in the form of a polyamine A2 —  the ratio of the number of aldehyde groups in the resin component K1 to the number of primary amino groups of said polyamine A2 in the hardener component K2 is preferably in the range from 0.5 to 1.0  particularly in the range from 0.8 to 1.0.
The hardener component K2 of the two-component epoxy resin compositions can comprise  besides the polyamine A1  additional compounds that are reactive with respect to epoxy groups  particularly mercapto group-comprising compounds  such as  in particular
- liquid mercaptan-terminated polysulfide polymers  known under the trade name Thiokol® (from Morton Thiokol; available  for example  from SPI Supplies or from Toray Fine Chemicals)  particularly the types LP-3  LP-33  LP-980  LP-23  LP-55  LP-56  LP-12  LP-31  LP-32 and LP-2; and also known under the trade name Thioplast® (from Akzo Nobel)  particularly the types G 10  G 112  G 131  G 1  G 12  G 21  G 22  G 44 and G 4;
- mercaptan-terminated polyoxyalkylene ethers  which can be produced  for example  by reacting polyoxyalkylene diols and triols with epichlorohydrin or with an alkylene oxide  followed by sodium hydrogen sulfide;
- mercaptan-terminated epoxy hardener in the form of polyoxyalkylene derivatives  known under the trade name Capcure® (from Cognis)  particularly the types WR-8  LOF and 3-800;
- polyesters of thiocarboxylic acids  for example  pentaerythritol tetramercaptoacetate  trimethylolpropane trimercaptoacetate  glycol dimercaptoacetate  pentaerythritol tetra-(3-mercaptopropionate)  trimethylolpropane tri-(3-mercaptopropionate) and glycol di-(3-mercaptopropionate)  as well as the esterification products of polyoxyalkylene diols and triols  ethoxylated trimethylolpropane and polyester diols with thiocarboxylic acids  such as  thioglycolic acid and 2- or 3-mercaptopropionic acid; and
- additional mercapto group-comprising compounds  such as  particularly  2 4 6-trimercapto-1 3 5-triazine  2 2""-(ethylenedioxy)-diethanethiol (triethylene glycol dimercaptan) and ethanedithiol.
Both the resin component K1 and also the hardener component K2 can contain additional auxiliary products and additives  such as  for example:
- solvents  film forming agents or extenders  such as  toluene  xylene  methyl ethyl ketone  2-ethoxy ethanol  2-ethoxy-ethylacetate  benzyl alcohol  ethylene glycol  diethylene glycol butyl ether  dipropylene glycol butyl ether  ethylene glycol butyl ether  ethylene glycol phenyl ether  N-methylpyrrolidone  propylene glycol butyl ether  propylene glycol phenyl ether  diphenylmethane  diisopropylnaphthalene  mineral oil fractions  such as  for example  Solvesso types (from Exxon)  aromatic hydrocarbon resins  particularly phenol group-containing types  sebacates  phthalates  organic phosphoric and sulfonic acid esters and sulfonamides;
- reactive diluents  for example  epoxy reactive diluents  as already mentioned above  epoxidized soybean oil or linseed oil  acetoacetate group-comprising compounds  particularly acetoacetylated polyols  butyrolactone  as well as furthermore isocyanates  and reactive group-comprising silicones;
- polymers  such as  for example  polyamides  polysulfides  polyvinylformal (PVF)  polyvinylbutyral (PVB)  polyurethanes (PUR)  polymers with carboxyl groups; polyamides  butadiene-acrylonitrile copolymers  styrene-acrylonitrile copolymers  butadiene-styrene copolymers  homo- or copolymers of unsaturated monomers  particularly from the group comprising ethylene  propylene  butylene  isobutylene  isoprene  vinyl acetate and alkyl(meth)acrylates  particularly chlorosulfonated polyethylenes and fluorine-containing polymers  sulfonamide-modified melamines and purified Montan waxes;
- inorganic and organic fillers  for example  ground or precipitated calcium carbonates coated optionally with fatty acids  particularly stearates; barite (heavy spar)  talcs  quartz flours  quartz sand  dolomites  wollastonites  kaolins  mica (potassium-aluminum silicate)  molecular sieves  aluminum oxides  aluminum hydroxides  silicic acids  cements  gypsums  flue ashes  carbon black  graphite  metal powders  such as  aluminum  copper  iron  silver or steel  PVC powder or hollow beads;
- fibers  for example  made of plastic or glass;
- pigments  for example  titanium dioxide and iron oxides;
- accelerators which accelerate the reaction between amino groups and epoxy groups  for example  acids or compounds that can be hydrolyzed to acids  for example  organic carboxylic acids  such as  acetic acid  benzoic acid  salicylic acid  2-nitrobenzoic acid  lactic acid  organic sulfonic acids  such as  methanesulfonic acid  p-toluenesulfonic acid or 4-dodecylbenzenesulfonic acid  sulfonic acid esters  other organic or inorganic acids  such as  for example  phosphoric acids  or mixtures of the above-mentioned acids and acid esters; moreover tertiary amines  such as  1 4-diazabicyclo[2.2.2]octane  benzyldimethylamine  a-methylbenzyldimethylamine  triethanolamine  dimethylaminopropylamine  salts of such tertiary amines  quaternary ammonium salts  such as  for example  benzyltrimethylammonium chloride  phenols  particularly bisphenols  phenol resins  and Mannich bases  such as  for example  2-(dimethylaminomethyl)-phenol and 2 4 6-tris-(dimethylaminomethyl)-phenol  phosphites  such as  for example  di- and triphenyl phosphites  as well as mercapto group-comprising compounds  as already mentioned above;
- rheology modifying agents  such as  particularly  thickeners  for example  layer silicates  such as  bentonites  derivatives of castor bean oil  hydrated castor bean oil  polyamides  polyurethanes  urea compounds  pyrogenic silicic acids  cellulose ethers  and hydrophobically modified polyoxyethylenes;
- bonding enhancers  for example  organoalkoxysilanes  such as  3-glycidoxypropyltrimethoxysilane  3-aminopropyltrimethoxysilane  N-(2-aminoethyl)-3-aminopropyltrimethoxysilane  N-(2-aminoethyl)-N""-[3-(trimethoxysilyl)propyl]ethylenediamine  3-ureidopropyltrimethoxysilane  3-chloropropyltrimethoxysilane  vinyltrimethoxysilanes  or the corresponding organosilanes with ethoxy groups instead of the methoxy groups;
- stabilizers against oxidation  heat  light and UV radiation;
- flame retardant substances  particularly compounds such as aluminum hydroxide (Al(OH)3; also referred to as ATH for "aluminum trihydrate")  magnesium hydroxide (Mg(OH)2; also referred to as MDH for "magnesium dihydrate")  ammonium sulfate ((NH4)2SO4)  boric acid (B(OH)3)  zinc borate  melamine borate  and melamine cyanurate; phosphorus-containing compounds  such as  ammonium phosphate ((NH4)3PO4)  ammonium polyphosphate  melamine phosphate  melamine pyrophosphate  triphenyl phosphate  diphenyl cresyl phosphate  tricresyl phosphate  triethyl phosphate  tris-(2-ethylhexyl)phosphate  trioctyl phosphate  mono-  bis- and tris-(isopropylphenyl) phosphate  resorcinol-bis(diphenyl phosphate)  resorcinol-diphosphate oligomer  tetraphenyl-resorcinol diphosphite  ethylenediamine diphosphate  and bisphenol A-bis(diphenyl phosphate); halogen-containing compounds  such as  chloroalkyl phosphates  particularly tris-(chloroethyl) phosphate  tris-(chloropropyl) phosphate  and tris-(dichloroisopropyl) phosphate  polybrominated diphenyl ethers  particularly decabromodiphenyl ether  polybromimated diphenyl oxide  tris-[3-bromo-2 2-bis(bromomethyl)propyl] phosphate  tetrabromo-bisphenol A  bis-(2 3-dibromopropyl ether) of bisphenol A  brominated epoxy resins  ethylene-bis(tetrabromophtalimide)  ethylene-bis(dibromonorbornane dicarboximide)  1 2-bis-(tribromophenoxy) ethane  tris-(2 3-dibromopropyl) isocyanurate  tribromophenol  hexabromocyclododecane  bis-(hexachlorocyclopentadieno) cyclooctane and chloroparaffins; as well as combinations of a halogen-containing compound and antimony trioxide (Sb2O3) or antimony pentoxide (Sb2O5);
- surfactants such as  for example  crosslinking agents  levelling agents  aeration agents or defoaming agents;
- biocides  such as  for example  algicides  fungicides or fungal growth-inhibiting substances.
The two-component epoxy resin composition preferably comprises additional auxiliary products and additives  particularly crosslinking agents  diluents  defoaming agents  stabilizers  pigments and accelerators  particularly  salicylic acid or 2 4 6-tris-(dimethylaminomethyl)phenol.
The two-component epoxy resin composition preferably comprises less than 10 wt%  preferably less than 5 wt%  benzyl alcohol. In particular  the two-component epoxy resin composition is free of benzyl alcohol.
The resin component K1 and the hardener component K2 can each be stored in a suitable packaging or arrangement  such as  for example  a drum  a hobbock  a pouch  a bucket  a can  a cartridge  or a tube  before their use  for several months up to a year and longer  without their respective properties changing to an extent of relevance for their use.
To use the two-component epoxy resin composition  the resin component K1 and the hardener component K2 are mixed with each other. The mixing ratio between the resin component K1 and the hardener component K2 is preferably selected in such a manner that the groups that are reactive with respect to epoxy groups  in the hardener component K2  are in a suitable ratio to the epoxy groups in the resin component K1.
The ratio of the number of groups that are reactive with respect to epoxy groups  in the hardener component K2  to the number of epoxy groups in the resin component K1 is appropriately in the range from 0.5 to 1.5  particularly 0.8 to 1.2  wherein as many primary amino groups are not counted as groups that are reactive with respect to epoxy groups as there are aldehyde groups present in the resin component K1.
It is known to the person skilled in the art that primary amino groups with respect to epoxy groups are bifunctional  and that a primary amino group is thus counted as two groups that are reactive with respect to epoxy groups.
In parts by weight  the mixing ratio between the resin component K1 and the hardener component K2 is usually in the range from 1:10 to 10:1.
The mixing of the two components occurs by means of an appropriate method; it can be carried out continuously or in batch mode. If the mixing occurs prior to the use  one must make sure that not too much time passes between the mixing of the components and the application  because this could lead to disturbances  such as  for example  a slowed or incomplete development of the adhesion to the substrate. The mixing is carried out particularly at ambient temperature  which is typically in the range from approximately 5 to 50 °C  preferably approximately 10-30 °C.
The curing of the described epoxy resin composition by chemical reaction starts with the mixing of the two components.
In the process  in the mixed composition  the aldehyde groups of the aldehyde from the resin component K1 react  on the one hand  rapidly with primary amino groups of the polyamine A1 from the hardener component K2  with the formation of aldimino groups and water (condensation reaction). The primary amino groups of the polyamine A1  which have reacted in this manner  are therefore subsequently substantially no longer available for a reaction with epoxy groups  under the given reaction conditions. For illustration  the reaction of benzaldehyde with PEHA at a molar ratio of 2:1 is represented here as an example in the following formula diagram (V).

Here  after the reaction  a hardener is produced according to the formula  which has four secondary amino groups  and which is free of primary amino groups. The water produced during the condensation reaction remains in the mixed composition  where it can have an accelerating effect during the curing under some circumstances. Depending on the ambient humidity  and on the temperature  the water evaporates more or less rapidly from the composition.
On the other hand  the NH hydrogens present in the mixed composition  and any additional groups that are present and reactive with respect to epoxy groups  start to react with epoxy groups with ring opening (addition reaction). As a result of these reactions  the composition polymerizes  and thus cures. It is observed that the described two-component epoxy resin composition  in spite of the lower content of primary amino groups  cures surprisingly rapidly  also at relatively low temperatures in the range from 5 to 10 °C.
The curing occurs particularly at ambient temperature  which is typically in the range from approximately 5 to 50 °C  preferably approximately 10-30 °C.
The curing typically takes several days to weeks  until it is substantially completed under the given conditions. The duration depends on the temperature  the reactivity of the components and their stoichiometry  and on the presence of accelerators  among other factors.
Thus  the present invention also describes a cured composition which was prepared by mixing the resin component K1 and the hardener component K2 of a two-component epoxy resin composition as described above.
A clear indication that the aldehyde binds covalently via aldimino groups to the cured polymer  during the curing of the two-component epoxy resin composition  is obtained from the observation that  in the two-component epoxy resin compositions according to the invention  shortly after the mixing of the two components  the band in the IR spectrum is no longer detectable in the range from 1750 to 1650 cm-1  which is typical for the given aldehyde group  while in the range from 1680 to 1620 cm-1  the band which is typical for the respective corresponding aldimino group is clearly and unequivocally detectable.
In the case of areal application of the described epoxy resin composition  wherein the application is in the form of a thin film which typically has a layer thickness of approximately 50 µm to approximately 5 mm  to a substrate  a substantially clear  glossy and nonadhesive film forms during the curing  which is of excellent quantity in terms of hardness and viscosity as well as adhesion to the substrate. In contrast to the above  corresponding compositions of the prior art that contain no aldehyde in the resin component K1 cure to films with blushing-caused surface defects  such as  roughness  spottiness  turbidity  and tackiness.
The application of the described epoxy resin composition occurs on at least one substrate  wherein  as substrate  the following are particularly suitable:
- glass  glass ceramic  concrete  mortar  brick  clay brick  gypsum and natural rock  such as granite or marble;
- metals or alloys  such as  aluminum  steel  iron  non-ferrous metals  zinc-coated metals;
- leather  textiles  paper  wood  resin-bonded wood materials  resin-textile composite materials  and additional so-called polymer composites;
- plastics  such as  polyvinyl chloride (hard and soft PVC)  acrylonitrile-butadiene-styrene copolymers (ABS)  SMC (Sheet Moulding Compounds)  polycarbonate (PC)  polyamide (PA)  polyester  poly(methylmethacrylate) (PMMA)  polyesters  epoxy resins  polyurethanes (PUR)  polyoxymethylene (POM)  polyolefins (PO)  polyethylene (PE) or polypropylene (PP)  ethylene/propylene copolymers (EPM) and ethylene/propylene/diene terpolymers (EPDM)  wherein the plastics can preferably be surface-treated by a plasma  corona or flame treatment; and
- coated substrates  such as  powder coated metals or alloys; as well as paints and lacquers.
If needed  the substrates can be subjected to a preliminary treatment before the application of the epoxy resin composition. Such preliminary treatments comprise in particular physical and/or chemical cleaning processes  for example  polishing  sandblasting  shot blasting  brushing or the like  wherein dust produced in the process are advantageously removed by suctioning  and also a treatment with cleaners or solvents  or the application of an adhesion promoting agent  an adhesion promoting agent solution  or a primer.
The two-component epoxy resin composition is especially suitable for areal applications.
The described epoxy resin composition can be used particularly as a coating  floor cover  paint  lacquer  primer or base coat  as well as an adhesive  sealant or casting compound. In these uses  its excellent properties  such as  waterproofness  corrosion protection  adhesion  resistance to chemicals  and/or hardness and viscosity are exploited. It can be used  for example  in above ground level construction or in underground construction  for example  as floor cover or as coating  for interior spaces  such as  offices  industrial halls  gymnasiums  or cooling chambers  or  outside  for balconies  terraces  parking decks  bridges or roofs  and as protective coating for concrete or metal  particularly as a protective paint against corrosion. Moreover  it can be used for the manufacture or repair of industrial products or consumer products.
The described two-component epoxy resin composition presents various advantages.
On the one hand  the resin component K1 has a relatively low viscosity  since the epoxy resin is diluted surprisingly well by the aldehyde  particularly if the latter is liquid at room temperature. For a coating  a low basic viscosity is an important prerequisite in order to ensure a good flow behavior  and thus a good application. Diepoxy liquid resins typically have a rather high viscosity  and they usually have to be diluted for use in coatings. The epoxy reactive diluents that are usually used for the dilution in the prior art are expensive  they often have a strong irritating effect  and they can induce allergies. The dilution effect of the aldehyde makes it possible to substantially or completely omit the use of epoxy reactive diluents or solvents in particular. Moreover  it is substantially simpler to pigment the resin component K1 if desired  if its viscosity is excessively low.
The presence of the aldehyde in the resin component K1 as well as any pigmentation of the resin component K1 moreover have the effect of increasing the volume of said component  which can be a great advantage for setting the mixing ratio that is suitable in practice. For application as a coating  the hardener component is often transferred by pouring in the container of the resin component  and the two components are mixed in it  and applied from it. In such a use it is advantageous if the mixing ratio is set in such a manner that the resin component has a rather large volume and the hardener component a rather small volume  because otherwise the resin component would have to be packaged in a container having a relatively large empty space  which results in high container costs and a high space requirement during storage and during transport.
The use of the described odorless aldehydes ALD presents additional advantages. They are odorless substances which have a relatively high molecular weight and a surprisingly good dilution effect  and which are not considered VOC. As a result  resin components K1 can be produced which are odorless and VOC-free  and which  under some circumstances  make it possible to completely omit the use of an epoxy reactive diluent.
On the other hand  few blushing effects occur with the described composition  particularly in areal application. This is presumably explained by the fact that the aldehyde reduces the content of primary amino groups during the mixing of the components  by the described reaction  to such an extent that said groups no longer react detectably with CO2. Surprisingly  this reaction  in spite of the absence of removal of the condensation water  and thus the absence of pressure on the reaction equilibrium  appears to take place rapidly  and to such an extent that the primary amino groups present in stoichiometric quantity with respect to the aldehyde no longer have sufficient time to react with CO2. This also applies under unfavorable reaction conditions  that is reaction conditions favoring blushing  in particular at lower curing temperature and higher air humidity. Therefore  it is possible to substantially or completely omit the addition of the blushing-reducing additives of the prior art  which are not bound covalently in the composition during the curing  and which outgas as VOC  particularly as benzyl alcohol.
In contrast  the aldehyde is bound covalently to the primary amino groups during the reaction  and it thus remains permanently in the cured composition  even in the presence of water. Thus  hardly any outgassing of the aldehyde from the curing  or cured  composition occurs  which has a very advantageous effect on the emission values as well as on the resistance to abrasion of the cured composition. The described composition can thus also be used particularly advantageously in interior spaces.
The water formed during the reaction between the aldehyde and the primary amino groups can accelerate the curing.
During the curing of the described composition  substantially clear  glossy or slightly opaque and adhesion-free films form  which have excellent mechanical properties  such as high hardness  good scratch resistance and toughness  as well as good adhesion on substrates of a great variety.
With the described composition  high-quality two-component epoxy resin systems are thus available  which  after their curing  have only a low content of volatile organic compounds (VOC) or are VOC-free.
It is an essential aspect of the invention that the aldehyde is part of the resin component K1 and not of the hardener component K2. Indeed  if the aldehyde were used as part of the hardener component K2  then  on the one hand  it would have no dilution effect in the resin component; on the other hand  during the areal use of such an epoxy resin composition that is not according to the invention  the films that form have a clearly poorer quality.
The present invention also relates to the use of an aldehyde for diluting an epoxy resin or an epoxy resin composition. Particularly suitable as aldehyde are the above-described aldehydes  particularly benzaldehyde or an aldehyde of formula (II).
The present invention further relates to a method for reducing blushing effects during the curing of a two-component epoxy resin composition  whose hardener component comprises at least one polyamine having at least one primary amino group  by adding an aldehyde to the resin component. As polyamine having at least one primary amino group  the above-described polyamines A1 are suitable  particularly the above-described polyamines A2 having at least one primary and one at least two secondary amino groups. The above-described aldehydes  particularly benzaldehyde or an aldehyde of formula (II)  are particularly suitable as aldehyde.

Examples
1. Description of the measurement methods
The viscosity was measured with a cone-plate viscometer Rheotec RC30 (cone diameter 50 mm  conical angle 1°  cone tip-plate separation 0.05 mm  shearing rate 10-100 s-1).

2. Raw materials used
Araldite® GY 250 (Huntsman) Bisphenol A diglycidyl ether  EEW approximately 187.5 g/Eq
Araldite® DY-E (Huntsman) Monoglycidyl ether of a C12-C14 alcohol  EEW approximately 290 g/Eq
Araldite® HY-960 (Huntsman) 2 4 6-Tris-(dimethylaminomethyl)phenol
Jeffamine® D-230 (Huntsman) Polypropylene glycol diamine 
average molecular weight approximately 240 g/mol
Pentaethylenehexamine
(Delamine) ("PEHA") Technical  molecular weight approximately 232 g/mol  amino number approximately 1220 mg KOH/g
Tetraethylenepentamine
(Delamine) ("TEPA") Technical  molecular weight approximately 189 g/mol 
amine number approximately 1350 mg KOH/g
N4-Amine (BASF) ("N4-amine") N N""-Bis(3-aminopropyl)ethylenediamine  molecular weight 174 g/mol
Diethylenetriamine (Delamine) ("DETA") Technical  molecular weight approximately 103 g/mol
Isophoronediamine (Evonik) ("IPDA") 1-Amino-3-aminomethyl-3 5 5-trimethylcyclohexane  molecular weight 170 g/mol
meta-Xylylenediamine (Mitsubishi Gas Chem.) "MXDA") 1 3-Bis(aminomethyl) benzene  molecular weight 136 g/mol
"AP-Ald" 3-Acetoxy-2 2-dimethylpropanal
"EH-Ald" 2-Ethylhexanal
"LP-Ald" 2 2-Dimethyl-3-lauroyloxypropanal
"MP-Ald" 2 2-Dimethyl-3-(N-morpholino) propanal
"PP-Ald" 2 2-Dimethyl-3-phenylpropanal

3. Preparation of two-component epoxy resin compositions
Comparison Examples 1-4 and Examples 5-7
For each one of the examples  a resin component and a hardener component were prepared separately  with the ingredients indicated in Table 1  in the indicated quantities (in parts by weight) (by mixing  if the component consisted of more than one ingredient)  and subsequently the resin component was mixed with the hardener component in a centrifugal mixer (SpeedMixer™ DAC 150  FlackTek Inc.). Using the mixed compositions  in each case a film in a layer thickness of 500 µm was applied to a glass plate  and said film was stored at 23 °C and 50% relative humidity (= normal climate  hereafter abbreviated "NC")  respectively cured. After 4 weeks  the appearance of the films was evaluated. A film was considered "defect-free" if it was clear  and had a hard  glossy  and nonadhesive surface without structure. The term "structure" is used here to denote any type of marking or pattern on the surface. Moreover  the König hardness (pendulum hardness according to König  measured according to DIN EN ISO 1522) of the films was determined after 14 days ("König hardness (14d)")  after 4 weeks ("König hardness (4w)")  and after 5 months ("König hardness (5mt)"). The odor of the mixed composition was evaluated twice by smelling with the nose at a separation of 1 cm  the first time 15 minutes after the mixing of the two components ("odor (15"")")  and the second time after a curing time of 4 weeks ("odor (4w)").
The results are reproduced in Table 1.

Example 1
(Compar.) 2
(Compar.) 3
(Compar.) 4
(Compar.)
5
6
7
Resin component:
Araldite® GY-250
Araldite® DY-E
Benzyl alcohol
Benzaldehyde
167.2
31.8
-
-
167.2
31.8
-
-
167.2
31.8
-
-
167.2
31.8
27.0
-
167.2
31.8
-
53.0
167.2
31.8
-
70.8
167.2
31.8
-
106.0
Hardener component:
PEHA
TEPA
N4-amine

29.0
-
-

-
27.0
-

-
-
29.0

29.0
-
-

58.0
-
-

-
63.0
-

-
-
87.0
Odor (15"") Amine Amine Amine Amine Amine Amine Amine
Odor (4w) None None None None None None None
König hardness (4w) n.m.1 n.m.1 n.m.1 151 s 163 s 130 s 70 s
Appearance msc msc msc kbB df df df
Table 1: Composition and properties of Comparison Examples 1-4 and of Examples 5-7.
"Compar." stands for "Comparison " "n.m." stands for "not measurable"
"Amine" stands for "smells slightly like an amine"
"msc" stands for "matte  strong structure  tacky coating"
"kbB"stands for "clear and glossy  but many small bubbles in the film"
"df" stands for "defect-free " 1 The coating distorts the measurements

From the Comparison Examples 1-3 it is apparent that two-component epoxy resin compositions which contain PEHA  TEPA or N4-amine as hardener  applied by areal application  during the curing in NC tend to considerable blushing  leading to cured films of poor quality. From Comparison Example 4  it is evident that  although the addition of benzyl alcohol suppresses blushing  bubbles form during the curing.
From Examples 5-7 according to the invention it is evident that the benzaldehyde of the resin component prevents blushing during the curing  and that the mixed compositions no longer smell like benzaldehyde  already shortly after the mixing of the two components in each case  although benzaldehyde is a substance with a strong  typically almond-like odor which is still detectable even in the smallest concentrations.

Example 8 and Comparison Examples 9  10 and 11
For each one of the examples  a resin component and a hardener component were prepared separately with the ingredients indicated in Table 2  in the quantities indicated (in parts by weight)  and then mixed as described for Example 5. Using the mixed compositions  in each case three films in a layer thickness of 500 µm were applied to a glass plate  and said glass plates were stored under different conditions  respectively cured. All three films were weighed immediately after the application and then left to stand for 4 days in NC ("(4d)")  and then the weight loss (in wt% with respect to the starting weight immediately after the application) was determined by renewed weighing. In each case one of the three plates was left in NC — marked "storage in NC" in the table — and  after 28 days  the weight loss ("(28d)") with respect to the same starting weight was determined again by renewed weighing. The other two glass plates were stored in a circulating air oven at 80 °C. In each case after 3  7 and 14 days  the weight loss of these plates after cooling for 2 hours in NC was determined ("(3d) " or "(7d)" or "(14d)")  with respect to the same starting weight  by renewed weighing. The appearance and the König hardness of the plates were determined in the same manner as for Example 5.
The results are indicated in Table 2.

Example
8 9
(Comparison) 10
(Comparison) 11
(Comparison)
Resin component:
Araldite® GY-250
Araldite® DY-E
Benzaldehyde
Benzyl alcohol
167.2
31.8
53.0
-
167.2
31.8
-
27.0
167.2
31.8
-
43.3
167.2
31.8
-
-
Hardener component:
PEHA
DETA
IPDA
Benzyl alcohol
Salicylic acid
58.0
-
-
-
-
29.0
-
-
-
-
-
20.6
-
-
-
-
-
42.5
47.2
4.7
Benzyl alcohol content - 10.5 wt% 16.5 wt% 16.1 wt%
Theoretical water content1 2.9 wt% - - -
Storage in NC:
Weight loss

Appearance

König hardness (4w)
1.5% (4d)
1.5% (28d)
defect-free

165 s
1.3% (4d)
1.3% (28d)
clear  fine bubbles
151 s
2.7% (4d)
3.7% (28d)
clear  fine bubbles
122 s
1.9% (4d)
2.3% (28d)
defect-free

160 s
Storage at 80 °C:
Weight loss

Appearance

König hardness (14d)
4.5% (3d)
5.1% (7d)
5.1% (14d)
yellow  slightly matte
189 s
7.6% (3d)
8.5% (7d)
8.9% (14d)
yellowish  larger bubbles
n.m.2
15.1% (3d)
16.0% (7d)
16.8% (14d)
yellowish  larger bubbles
n.m.2
8.8% (3e)
10.5% (7d)
12.0% (14d)
yellowish

182 s
Table 2: Composition and properties of Example 8 and of Comparison Examples 9-11. "n.m." stands for "not measurable"
1 from the aldimine formation 2 Bubbles distort the measurements

It is evident from Table 2 that Example 8 according to the invention loses only slightly more weight than the water formed by the reaction of benzaldehyde with the primary amino groups of PEHA during the 80 °C storage. This low weight loss is clearly a sign that the benzaldehyde is bound to the cured epoxy polymer  and therefore does not evaporate at 80 °C. Comparison Examples 9-11  on the other hand  lose considerably more weight during the 80 °C storage. Since benzyl alcohol is not bound to the epoxy polymer  most of it evaporates from the films. In Comparison Examples 9 and 10  which already presented bubbles in the film  the latter became clearly larger during the 80 °C storage.

Comparison Examples 12 and 13 and Examples 14-18
For each one of the examples  a resin component and a hardener component was prepared separately with the ingredients indicated in Table 3  in the indicated quantities (in parts by weight)  and then mixed as described for Example 5. Using the mixed compositions  a film in a layer thickness of 500 µm was applied in each case to a glass plate  and the latter was stored in NC  respectively cured. After 5 months  the appearance of the films and the König hardness were determined in the same manner as for Example 5.
The results are indicated in Table 3.
PEHA-aldimine-1 was prepared as follows:
29 parts by weight PEHA were used to start; 26.5 parts by weight benzaldehyde were added under stirring  and then the water produced was removed from the reaction mixture at 80 °C and under a vacuum for one hour.
It is evident from Table 3 that the benzaldehyde dose of Examples 14-16 is sufficiently high to substantially prevent blushing effects during the curing  while the films of Examples 17 and 18 present signs of slight blushing. Moreover  it is evident that the films of Examples 15 and 16 present the highest hardness values. The films of Examples 17 and 18 present a lower hardness  presumably also due to slight blushing effects.

Example 12
(Compar.) 13
(Compar.) 14
15 16 17 18
Resin component:
Araldite® GY-250
Araldite® DY-E
Benzaldehyde
167.2
31.8
-
167.2
31.8
-
167.2
31.8
53.0
167.2
31.8
43.4
167.2
31.8
35.4
167.2
31.8
28.5
167.2
31.8
22.7
Hardener component:
PEHA
Benzaldehyde
PEHA-Aldimine-1
-
-
102.0
58.0
53.0
-
58.0
-
-
52.7
-
-
48.3
-
-
44.6
-
-
41.4
-
-
Aldehyde/NH21 1.0 1.0 1.0 0.9 0.8 0.7 0.6
König hardness (5mt) 167 s 171 s 185 s 193 s 197 s 167 s 134 s
Appearance slightly turbid  slightly tacky slightly turbid defect-free defect-free minimally turbid slightly turbid  slightly tacky slightly turbid  slightly tacky
Table 3: Composition and properties of Comparison Examples 12 and 13 and of Examples 14-18. 1 Ratio of the number of aldehyde groups to the number of primary amino groups.

Comparison Examples 12 and 13 comprise benzaldehyde as component of the hardener component instead of the resin component  wherein  in Comparison Example 12  the water formed during the aldimine formation was removed. The corresponding cured films  however  are of poorer quality than the cured film of Example 14  both in terms of appearance and also hardness.

Examples 19-24
For each one of the examples  a resin component and a hardener component was produced separately with the ingredients indicated in Table 4  in the indicated quantities (in parts by weight)  and then mixed as described for Example 5. Using the mixed compositions  in each case a film in a layer thickness of 500 µm was applied to a glass plate  and the latter was stored in NC  respectively cured. After 4 weeks  the appearance of the film and the König hardness were determined in the same manner as described for Example 5.
The results are indicated in Table 4.
Example 19 20 21 22 23 24
Resin comp.:
Araldite® GY-250
Araldite® DY-E
Benzaldehyde
LP-Ald
167.2
31.8
47.8
-
167.2
31.8
47.8
-
167.2
31.8
47.8
-
187.5
-
-
71.0
187.5
-
-
47.3
167.2
31.8
17.1
-
Hardener comp.:
PEHA
IPDA
MXDA
Jeffamine® D-230
Araldite® HY-960
52.2
4.25
-
-
-
52.2
-
3.4
-
-
52.2
-
-
6.0
-
29.0
21.25
-
-
6.0
-
28.3
-
40.0
-
-
28.3
-
40.0
-
König hardness (4w) 164 s 150 s 154 s 161 s 157 s 170 s
Appearance clear  fine structure defect-free defect-free clear  fine structure opaque  minimal structure clear  fine structure
Table 4: Composition and properties of Examples 19-24.
"Comp." stands for "component"

It is evident from Table 4 that Examples 19-22 which comprise a combination of PEHA and IPDA  or MXDA  or Jeffamine® D-230  as hardener  and wherein benzaldehyde  respectively L-Ald  is added by metering in each case stoichiometrically with respect to the primary amino groups of PEHA  cure to qualitatively good films. Moreover  it is evident from Table 4 that Examples 23 and 24  which both comprise a hardener component without secondary amino groups  cured to a qualitatively good films.

Examples 25-31
For each one of the examples  a resin component and a hardener component were produced with the ingredients indicated in Table 5  in the indicated quantities (in parts by weight)  and subsequently mixed as described for Example 5. Using the mixed compositions  in each case a film in a layer thickness of 500 µm was applied to a glass plate  and the latter was stored in NC  respectively cured. After 5 months  the appearance of the film and the König hardness were determined in the same manner as described for Example 5.
The results are indicated in Table 5.
Example 25 26 27
28 29 30 31
Resin comp.:
Araldite® GY-250
Araldite® DY-E
Benzaldehyde
LP-Ald
EH-Ald
PP-Ald
AP-Ald
MP-Ald
Salicylaldehyde
167.2
31.8
38.6
38.6
-
-
-
-
-
167.2
31.8
-
-
64.1
-
-
-
-
167.2
31.8
-
-
-
81.0
-
-
-
167.2
31.8
-
-
-
-
72.0
-
-
167.2
31.8
-
-
-
-
-
85.5
-
167.2
31.8
-
-
-
-
-
-
61.0
187.5
-
-
142.0
-
-
-
-
-
Hardener comp.:
PEHA
58.0
58.0
58.0
58.0
58.0
58.0
58.0
König hardness (5mt) 105 s 56 s 145 s 115 s 95 s 220 s 50 s
Appearance defect-free clear  fine structure defect-free defect-free defect-free defect-free  yellow defect-free
Table 5: Composition and properties of Examples 25-31.
"Comp." stands for "Component"

It is evident from Table 5 that using aldehydes combined with PEHA  films of good quality are obtained.

Examples 32-35
For each one of the examples  a resin component and a hardener component were prepared with the ingredients indicated in Table 6  in the indicated quantities (in parts by weight)  and then mixed as described for Example 5. Using the mixed compositions  in each case a film in a layer thickness of 500 µm was applied to the glass plate  the latter was stored in NC  respectively cured. After 4 weeks  the appearance of the film and the König hardness were determined in the same manner as described for Example 5.
The results are indicated in Table 6.
The adduct 1 was prepared as follows:
36.8 g N4-amine were mixed with 13.2 g Araldite® GY-250 and left to stand for 2 hours at 60 °C. A clear fluid formed having a viscosity at 20 °C of 1.1 Pa·s.
The adduct 2 was prepared as follows:
20.0 g adduct 1 were mixed with 11.2 g benzaldehyde. A clear fluid having a viscosity at 20 °C of 76.8 Pa·s formed.
The adduct 3 was prepared as follows:
10.26 g TEPA and 19.55 g Jeffamine® D-230 were mixed with 10.18 g Araldite® GY-250  and left to stand for 2 hours at 60 °C. A clear fluid having a viscosity at 20 °C of 3.5 Pa·s formed.
It is evident from Table 6 that the compositions which contain  as polyamine A1  an amine/polyepoxy adduct having primary and secondary amino groups  cured to qualitatively good films exhibiting hardly any blushing.
Example 32 33 34 35
Resin component:
Araldite® GY-250
Araldite® DY-E
Benzaldehyde
LP-Ald
167.2
31.8
75.8
-
187.5
-
56.9
50.7
187.5
-
-
50.7
187.5
-
-
28.4
Hardener component:
Adduct 1
Adduct 2
Adduct 3
101.4
-
-
101.4
-
-
-
158.3
-
-
-
73.7
König hardness (4w) 195 s 172 s 154 s 200 s
Appearance defect-free defect-free clear  fine structure minimally turbid
Table 6: Composition and properties of Examples 32-35.

Example 36
Using the composition of Example 5  a film in a layer thickness of 500 µm was applied six times to glass plates  and said plates were stored under different conditions  as described below.
Plate No. 1 was stored for 21 days in NC (marked "NC" in Table 7).
Plate No. 2 was stored for 11 days in NC  then immersed for 7 days in water  and then stored again for 3 days in NC (marked "NC  H2O" in Table 7).
Plate No. 3 was stored for 11 days in NC  then for 7 days at 70 °C and 100% relative humidity  and then again for 3 days in NC (marked "NC  70/100" in Table 7).
Plate No. 4 was stored for 4 days in NC  then for 7 days in a circulating air oven at 80 °C  and then again for 10 days in NC (marked "80 °C" in Table 7).
Plates No. 5 were stored for 4 days in NC  then for 7 days in a circulating air oven at 80 °C  then immersed for 7 days in water  and then stored again for 3 days in NC (marked "80 °C  H2O" in Table 7).
Plate No. 6 was stored for 4 days in NC  then for 7 days in a circulating air oven at 80 °C  then for 7 days at 70 °C and 100% relative air humidity  and then again for 3 days in NC (marked "80 °C  70/100" in Table 7).
All the plates were weighed immediately after the application of the composition and then stored as described  and subsequently the weight loss was measured by renewed weighing  and the appearance and the König hardness were determined in the same manner as described for Example 5.
The results are indicated in Table 7.
Plate No. 1 No. 2 No. 3 No. 4 No. 5 No. 6
Storage NC NC 
H2O NC 
70/100 80 °C 80 °C 
H2O 80 °C 
70/100
Weight loss 1.5% 0.5% 2.8% 3.4% 2.8% 3.7%
König hardness 155 s 153 s 167 s 189 s 177 s 188 s
Appearance df df df ym ym ym
Table 7: Results of Example 36.
"df" stands for "defect-free"
"ym" stands for "yellow  slightly matte"

It is evident from Table 7 that storage for 7 days in water  respectively at 70 °C and 100% relative air humidity  has no substantial effect on the properties of the cured composition. In particular  it is apparent that even in a wet  respectively a moist and warm  environment  benzaldehdye is not released to a substantial extent from the cured composition.

Examples 37 and 38 and Comparison Examples 39 and 40
For each one of the examples  a resin component was prepared with the ingredients indicated in Table 8  in the indicated quantities (in parts by weight)  and subsequently the viscosity was determined.
The results are indicated in Table 8.
Example 37 38 39
(Comparison) 40
(Comparison)
Araldite® GY-250 80 80 80 100
Benzyl alcohol - - 20 -
Benzaldehyde 20 - - -
LP-Ald - 20 - -
Viscosity at 20 °C 0.5 Pa·s 1.2 Pa·s 0.7 Pa·s 18.6 Pa·s
Table 8: Composition and viscosity of Examples 37 and 38 and of the Comparison Examples 39 and 40.

It is evident from Table 8 that both benzaldehyde and also LP-Ald dilute the epoxy resin Araldite® GY-250 similarly to  or even better than  benzyl alcohol.

Examples 41-43 and Comparison Examples 44 and 45
For each one of the examples  a resin component was prepared with the ingredients indicated in Table 9  in the indicated quantities (in parts by weight)  and subsequently the viscosity at 20 °C of each composition was measured (marked "Visc. (Start)" in Table 9)  and then each composition was filled into two aluminum tubes and sealed airtight.
In each case one of the tubes was stored for 7 days at 20 °C and then the viscosity was measured at 20 °C (marked "Visc. (7d 20 °C)" in Table 9).
The second tube was stored for 7 days at 60 °C  and in each case the viscosity was subsequently measured at 20 °C (marked "Visc. (7d 60 °C)" in Table 9).
The results are indicated in Table 9.
It is evident from Table 9 that all the tested resin components (Examples 41-43 and Comparison Examples 44 and 45) presented no measurable viscosity increase in the case of storage for 7 days at room temperature  respectively only a slight viscosity increase in the case of storage for 7 days at 60 °C.
Example 41 42 43 44
(Comparison) 45
(Comparison)
Araldite® GY-250 167.2 167.2 187.5 167.2 167.2
Araldite® DY-E 31.8 31.8 - 31.8 31.8
Benzaldehyde 53.0 - - - -
Salicylaldehyde - 61.0 - - -
LP-Ald - - 50.7 - -
Benzyl alcohol - - - 50.0 -
Visc. (Start) [mPa·s] 195 205 1200 230 1020
Visc. (7d 20 °C) [mPa·s] 195 205 1200 230 1020
Visc. (7d 60 °C) [mPa·s] 210 225 1250 245 1100
Table 9: Composition and properties of Examples 41-43 and of Comparison Examples 44 and 45.

We claim:-
1. Two-component epoxy resin composition consisting of a resin component K1 which comprises at least one epoxy resin and at least one aldehyde  and
a hardener component K2 which comprises at least one polyamine A1 having at least one primary amino group.
2. Two-component epoxy resin composition according to Claim 1  characterized in that the aldehyde is selected from the group consisting of 2-ethylbutanal  pentanal  pivalaldehyde  2-methylpentanal  3-methylpentanal  4-methylpentanal  2 3-dimethylpentanal  hexanal  2-ethylhexanal  heptanal  octanal  methoxyacetaldehyde  2 2-dimethyl-3-phenylpropanal  benzaldehyde  1-naphthaldehyde  salicylaldehyde and aldehydes of formula (II)  particularly 3-acetoxy-2 2-dimethylpropanal  2 2-dimethyl-3-lauroyloxypropanal  2 2-dimethyl-3-(N-morpholino)-propanal  and 2 2-dimethyl-3-bis-(methoxyethyl)-aminopropanal 

where R1 and R2
in each case stand  independently of each other  either for a monovalent hydrocarbon residue having 1-12 C atoms 
or together for a bivalent hydrocarbon residue having 4-12 C atoms  which is part of an optionally substituted carbocyclic ring having 5-8  preferably 6 C atoms;
R3 stands for a hydrogen atom or for an arylalkyl or cycloalkyl or alkyl group having 1-12 C atoms  particularly for a hydrogen atom; and
Z stands for an ester  ether  tertiary amino or amido group having up to 31 C atoms  which groups optionally contain additional ether oxygens.
3. Two-component epoxy resin composition according to Claim 2  characterized in that Z stands for a residue of formula (III) or (IV) 

where R5
stands either for a hydrogen atom
or for a linear or branched alkyl residue having 1-30  preferably 6-30  most preferably 11-30 C atoms  optionally with cyclic portions  and optionally with at least one heteroatom  particularly oxygen in the form of ether  carbonyl or ester groups 
or for a singly or multiply unsaturated  linear or branched hydrocarbon residue having 5-30 C atoms 
or for an optionally substituted aromatic or heteroaromatic  5- or 6-membered ring; and
R9 and R10 
independently of each other  in each case stand either for a monovalent aliphatic  cycloaliphatic or arylaliphatic residue having 1-20 C atoms  which optionally contains heteroatoms in the form of ether oxygen or tertiary amine nitrogen 
or together they stand for a bivalent aliphatic residue having 3-20 C atoms  which is part of an optionally substituted  heterocyclic ring having 5-8  preferably 6 ring atoms  and contains  besides the nitrogen atom  optionally additional heteroatoms in the form of ether oxygen or tertiary amine nitrogen.
4. Two-component epoxy resin composition according to Claim 2 or 3  characterized in that R1 and R2 each stand for a methyl residue.
5. Two-component epoxy resin composition according to Claim 2 or 3 or 4  characterized in that R5 has 11-30 C atoms  particularly 11-20 C atoms.
6. Two-component epoxy resin composition according to one of the previous claims  characterized in that the aldehyde is selected from the group consisting of benzaldehyde  salicylaldehyde  2 2-dimethyl-3-phenylpropanal  3-acetoxy-2 2-dimethylpropanal  2 2-dimethyl-3-lauroyloxypropanal  and 2 2-dimethyl-3-(N-morpholino)-propanal.
7. Two-component epoxy resin composition according to one of the previous claims  characterized in that the resin component K1 has an aldehyde content of at least 1 wt%  preferably at least 3 wt%.
8. Two-component epoxy resin composition according to one of the previous claims  characterized in that the epoxy resin is a liquid resin based on a bisphenol  particularly based on bisphenol A  bisphenol F or bisphenol A/F.
9. Two-component epoxy resin composition according to one of the previous claims  characterized in that the polyamine A1 is a polyamine A2  where the polyamine A2 has at least one primary and at least two secondary amino groups.
10. Two-component epoxy resin composition according to Claim 9  characterized in that the polyamine A2 is selected from the group consisting of
triethylenetetramine (TETA)  tetraethylenepentamine (TEPA)  pentaethylenehexamine (PEHA)  polyethylenepolyamine having 5-7 ethyleneamine units (HEPA)  N N""-bis(3-aminopropyl)ethylenediamine;
adducts of diethylenetriamine (DETA)  dipropylenetriamine (DPTA)  bis-hexamethylenetriamine (BHMT)  triethylenetetramine (TETA)  tetraethylenepentamine (TEPA)  pentaethylenehexamine (PEHA)  polyethylenepolyamine having 5-7 ethyleneamine units (HEPA) or N N""-bis(3-aminopropyl)ethylenediamine with a diglycidyl ether  particularly a diglycidyl ether of bisphenol A  bisphenol F  bisphenol A/F  ethylene glycol  propylene glycol  butylene glycol  hexanediol  octanediol or a polypropylene glycol; and polyamidoamines.
11. Two-component epoxy resin composition according to one of the previous claims  characterized in that the ratio of the number of aldehyde groups in the resin component K1 to the number of primary amino groups in the hardener component K2 is in the range from 0.1 to 1.1.
12. Cured composition which is obtained by mixing the resin component K1 and the hardener component K2 of a two-component epoxy resin composition according to one of Claims 1-11.
13. Use of a two-component epoxy resin composition according to one of Claims 1-11 as a coating  floor cover  paint  lacquer  primer or base coat  and as adhesive  sealant or casting composition.
14. Use of an aldehyde  particularly benzaldehyde or an aldehyde of formula (II)  for diluting an epoxy resin or an epoxy resin composition

where R1 and R2
in each case stand  independently of each other  either for a monovalent hydrocarbon residue having 1-12 C atoms 
or together for a bivalent hydrocarbon residue having 4-12 C atoms  which is part of an optionally substituted carbocyclic ring having 5-8  preferably 6 C atoms;
R3 stands for a hydrogen atom or for an arylalkyl or cycloalkyl or alkyl group having 1-12 C atoms  particularly for a hydrogen atom; and
Z stands for an ester  ether  tertiary amino or amido group having up to 31 C atoms  which groups optionally contain additional ether oxygens.
15. Method for reducing blushing effects during the curing of a two-component epoxy resin composition whose hardener component comprises at least one polyamine having at least one primary amino group  by adding an aldehyde to the resin component  particularly benzaldehyde or an aldehyde of formula (II) 

where R1 and R2
in each case stand  independently of each other  either for a monovalent hydrocarbon residue having 1-12 C atoms 
or together stand for a bivalent hydrocarbon residue having 4-12 C atoms  which is part of an optionally substituted carbocyclic ring having 5-8  preferably 6 C atoms;
R3 stands for a hydrogen atom or for an arylalkyl or cycloalkyl or alkyl group having 1-12 C atoms  particularly for a hydrogen atom; and
Z stands for an ester  ether  tertiary amino or amido group having up to 31 C atoms  which groups optionally contain additional ether oxygens.

Dated this 5th day of June 2012