Note: Descriptions are shown in the official language in which they were submitted.
21387~8
- NOVEL EPOXY-AMINE ADDUCTS AS CURING
AGENTS FOR AQUEOUS EPOXY SYSTEMS
Back~round of the Invention
1. Field of Invention
This invention relates to the use of aminourethanes in preparing water-
dilutable epoxy-amine adducts to improve the surface quality of the adducts
and provide readily sandable films.
2. Description of Related Art
Because of environmental regulations, which are becoming more and
more stringent, aqueous systems are g~ining increasing importance for use in
coating articles. In terms of their properties, they must be measured against
conventional, ie., solvent-cont~ining systems. Water-dilutable epoxy resin
systems have gained increasing importance among cold-curing water-based
coating systems. These two-component systems have outstanding properties.
The following positive properties are to be emphasized: little or no solvent
content, not a fire hazard, little or no odor, ease of processing, low degree ofsensitivity toward moist substrates, good drying and rapid through-hardening,
excellent adhesion to most substrates, very good intercoat adhesion, good pro-
tection of metals against corrosion, and easy cleaning of equipment directly
after use.
Nonionically dispersed epoxy resin systems, in particular those described
in DE-A 3 643 751, together with aqueous amine-based curing agents specified
in EP-A 0 000 605, exhibit these outstanding properties and can therefore be
used in a versatile manner as coating compositions. The disclosures of these
documents are incorporated by references herein in their entirety. A
disadvantage of these systems, however, is that they do not produce defect-free
surfaces in certain coating applications. Furthermore, it has not hitherto been
possible to use aqueous two-component systems based preferably, because of
their outstanding properties, on epoxy resins, to produce primers and fillers
~13874~
which, after a short drying time, can be wet- or even dry-sanded. In general,
the systems previously known are much too soft. Because of the pronounced
thermoplasticity, after a short time the sandpaper exerts a severe effect and
the surface is damaged.
Summary of the Invention
It is an object of the present invention to provide an improved aqueous,
epoxy-amine curing agent that possesses the advantages mentioned above and
further can be sanded.
The present invention therefore describes the incorporation into
10 aqueous, epoxy-amine adduct-based curing agents, compounds which have
other uses and are known per se (EP-A 0 234 395), which not only possess
urethane structures insensitive to hydrolysis and contribute to improving the
surface quality but also, because of their specific chemical structure, produce
very readily sandable films.
In accordance with these objectives, and other objectives readily
apparent to those skilled in the art, there is provided a method of using
aminourethanes in the preparation of water-dilutable epoxy-amine adducts,
the aminourethanes (A) being obtained by reaction of
(al) oligomeric or polymeric compounds containing at least one,
preferably two or more, cyclic carbonate groups such as terminal
2-oxo-1,3-dioxolane groups, and
(a2) compounds cont~ining at least one primary, preferably two or
more primary and, if desired, also secondary and tertiary amino
groups,
25 wherein the ratios of numbers of cyclic carbonate groups such as 2-oxo-1,3-
dioxolane groups to primary amino groups preferably is from 1:10 to 1:1.1, and
more preferably from 1:5 to 1:1.5.
In accordance with another object of the present invention, there is
provided curing compositions for epoxy resins at room temperature or for
30 forced drying, comprising an adduct of the abovementioned aminourethanes
~1387~8
(A), and if desired, in a mixture with further polyamines (a2), with water
dilutable epoxy resins (B). These epoxy resins (B) may comprise condensation
products of a polyol having a weight-average molar mass (Mw) of from 200 to
20,000 g/mol with an epoxy compound having at least two epoxide groups per
5 molecule and having a molar mass divided by the number of epoxy groups
(epoxide equivalent weight) of from 100 to 2000 g/mol, the ratio of numbers
of the OH groups to the epoxy groups being from 1:3.51 to 1:10, preferably
from 1:4 to 1:8, and the epoxide equivalent weight of these condensation
products being between 150 g/mol and at least 8000 g/mol, preferably
between 250 g/mol and 1000 g/mol.
In accordance with an additional object of the invention, there is
provided a process for the preparation of these novel epoxy-amine adducts.
These and other objects of the invention will be readily apparent to those
skilled in the art upon review of the detailed description of the invention thatfollows.
Detailed Description of the Preferred Embodiments
Suitable aminourethanes (A) for use in the invention have been
described in EP-A 0 234 395 where, however, they are preferably employed
as a flexibilizing binder which, after partial neutralization with organic and
inorganic acids, are employed for electrodeposition coating. The disclosure
of EP-A 0 239 355 is incorporated by reference herein in its entirety. This
document also mentions their use in combination with curing agents for 2-
component coating systems which crosslink by means of external agents, such
curing agents being blocked isocyanates, ,~-hydroxy esters of at least
difunctional polycarboxylic acids, reaction products of dialkyl malonates with
aldehydes and ketones, transesterification curing agents and Michael addition
products, but does not mention their use for the preparation of water-dilutable
epoxy-amine adducts as aqueous curing agents for aqueous epoxy resin
systems.
The compounds (A) can be subjected alone, or preferably in combina-
tion with, conventional polyamines (a2), to an addition reaction with
21387~
- hydrophilic epoxy resins, and in this form they can be employed as a curing
component for aqueous epoxy resin formulations as described in, for example,
DE-A 3 643 751. Surprisingly, in this context the abovementioned favorable
properties (improved surface and sandability) are achieved without any
5 impairment in the hitherto good properties of the aqueous 2-component epoxy
systems. There is, therefore, a surprisingly unexpected combination of the
outst~n(lin~ properties of the aminourethanes (A) with the aqueous polyamine
curing agents in accordance with, for example, EP-A 0 000 605.
Suitable components (al) are all carbonates which can be obtained by
10 reacting carbon dioxide with epoxy compounds in a known manner (see e.g,
PCT(WO) 84/03 701, DE-A 35 29 263 and DE-A 36 00 602). These epoxy
compounds preferably are polyglycidyl ethers based on polyhydric, preferably
dihydric, alcohols, phenols, hydrogenation products of these phenols and/or
on novolaks (reaction products of mono- or polyhydric phenols with aldehydes,
15 especially formaldehyde, in the presence of acidic catalysts). The epoxide
equivalent weights of these epoxy compounds are preferably between 100 and
2000, in particular between 100 and 350 g/mol.
Suitable polyhydric phenols are mono- and multinuclear phenols, and
those derived from aromatic systems linked by a covalent bond or bridging
20 groups such as alkylene, carbonyl, ether, thioether, or sulphone groups.
Examples of polyhydric phenols include resorcinol, hydroquinone, 2,2-
bis-(4'-hydroxyphenyl)propane (bisphenol A), isomer mixtures of
dihydroxydiphenylmethane (bisphenol F), tetrabromobisphenol A, 4,4'-
dihydroxydiphenylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenylpropane,
4,4'-dihydroxybiphenyl, 4,4'-dihydroxybenzophenone, 1,1-bis(4'-
hydroxyphenyl)ethane, 2,2-bis[4'-(2"-hydlo~y~ropoxy)phenyl]propane, 1,1-bis(4'-
hydroxyphenyl)isobutane, 2,2-bis-(4'-hydroxy-tert-butylphenyl)propane, bis(2-
hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene, tris(4-
hydroxyphenyl)methane, bis(4-hydroxyphenyl) ether, bis(4-hydroxyphenyl)
sulfone etc., and also the halogenation and hydrogenation products of the
abovementioned compounds. Bisphenol A is particularly preferred in this
regard.
21387~
s
Examples of polyhydric alcohols include ethylene glycol, diethylene
glycol, triethylene glycol, polyethylene glycols (n = 4 to 35), 1,2-propylene
glycol, polypropylene glycols (n = 2 to 15), 1,3-propylene glycol, 1,4-
butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, glycerol,
neopentylglycol, trimethylolethane and trimethylolpropane. Polyethylene
glycols (n = 8 - 10) are particularly preferred in this regard.
A comprehensive list of suitable epoxy compounds can be found in the
handbook "Epoxidverbindungen und Epoxidharze" (Epoxy Compounds and
Epoxy Resins) by A.M. Paquin, Springer Verlag, Berlin 1958, chapter IV and
in Lee, Neville "Handbook of Epoxy Resins", McGraw-Hill Book Co., 1967,
chapter 2. The abovementioned epoxy compounds may be employed
individually or as a mixture.
Suitable amine components (a2) are all amines, preferably polyamine
compounds, which contain primary amino groups which are able to react with
the carbonate groups of the compounds of component (al); these may be
polyamines, amine-epoxy adducts or modified derivatives thereof.
The polyamines (a2) preferably have the formula
~ N--A--R-- NHz C I ~
3/
in which
Rl is a divalent hydrocarbon radical, preferably a straight-chain or
branched alkylene radical having 2 to 18 carbon atoms, preferably 2 to
4 carbon atoms,
R2 is hydrogen, alkyl having 1 to 8 carbon atoms, preferably 1 to 4 carbon
atoms, or hydroxyalkyl having 1 to 8 carbon atoms, preferably 1 to 2
carbon atoms, in the alkyl radical,
213~7~
R3 is selected from the same group as R2, and R2 and R3 may also form a
cyclic ring compound, preferably a 5-, 6- or 7-membered aliphatic ring,
or if R2 is hydrogen, R3 may also be a group of the formula
Cl to Cl8-alkyl-COO-CH2-CH(OH)-CH2-,
S Cl to Cl8-alkyl-O-CH2-CH(OH)-CH2-,
NC-CH2-CH2- or
Cl to Cl8-alkyl-CHOH-CH2-, and
A is a chemical bond or may represent -(Rl-NH)r-RlNH in which r is zero or
an integer from 1 to 6 and Rl is as defined above.
Examples of suitable polyamines include alkyleneamines such as
ethylenediamine, propylenediamine, polyalkyleneamines such as
diethylenetriamine, triethylenetetramine, tetraethylenepentamine,
pentaethylenehexamine, propylene(li~mine, dipropylenetriamine etc., and also
2,2,4- and 2,4,4-trimethylhexamethylenediamine, bis(3-aminopropyl)amine,
N,N-bis(3-aminopropyl)ethylenediamine, neopentanediamine, 2-methyl-1,5-
pentanediamine, 1,3-diaminopentane, hexamethylenediamine, and also
cycloaliphatic amines such as 1,2- or 1,3-diaminocyclohexane, 1,4-rli~minn-3,6-
diethylcyclohexane, 1,2-diamino-4-ethylcyclohexane, 1-cyclohexyl-3,4-
di~3minncyclohexane, isophoronediamine and reaction products thereof, 4,4'-
~ minc)dicyclohexylmethane and -propane, 2,2-bis(4-aminocyclohexyl)methane
and -propane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3-amino-1-
cyclohexylaminopropane [1,4-bis(3'-aminopropyl)piperazinel and 1,3- and
1,4-bis(aminomethyl)cyclohexane.
Araliphatic amines which can be employed include, in particular, those
in which aliphatic amino groups are present, for example meta- and para-
xylylenediamine or hydrogenation products thereof. The abovementioned
amines may be used alone or in the form of mixtures. In any case, the amines
should be chosen such that the final product contains at least one, but
preferably more than one, free primary amino group.
Examples of suitable amine-epoxy adducts include reaction products of
polyamines, for example ethylenediamine, propylenediamine, hexa-
methylenediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, meta-
xylylenediamine and/or bis(aminomethyl)cyclohexane, with terminal mono- or
213~
polyepoxides, for example propylene oxide, hexene oxide or cyclohexene oxide,
or with glycidyl ethers such as phenyl glycidyl ether, tert-butyl glycidyl ether,
ethylhexyl glycidyl ether or butyl glycidyl ether, or with glycidyl esters, such as
the glycidyl ester of ~Versatic acid marketed by Shell, ~Cardura E, or the
5 abovementioned polyglycidyl ethers and polyglycidyl esters.
In addition to the abovementioned polyamines, it also is possible to
employ water-soluble polyoxyalkylene-~ mines and polyoxyalkylenepolyamines
having molecular weights of from 100 to 2000 g/mol, for example the products
marketed by Texaco under the tradename Jeffamine~, and readily water-
dispersible curing agents as described in DE-B 23 32 177 and EP-B 0 000 605,
ie., for example modified amine adducts, in order to increase the
hydrophilicity and therefore the solubility or dispersibility of the amino-
urethanes in water or in aqueous amine curing agents.
The reaction of components (al) and (a2) is generally carried out in the
15 stoichiometric ratios required by conventional methods at elevated
temperatures, if desired with the use of inert solvents. Reaction in the
presence of solvents which are inert toward the cyclocarbonate group is a
preferred process variant. The basis for the stoichiometric evaluation of both
the starting materials and the end products, and for monitoring the reaction,
20 is the amine number (determined by titration with perchloric acid) and the
cyclocarbonate equivalent number (determined by titration with potassium
hydroxide solution). In the reaction of components (al) and (a2) the
polyamino compounds can be employed individually or as mixtures,
simultaneously or in chronological succession, and if desired dissolved in inert25 solvents. Those skilled in the art are capable of determining the
stoichiometric amount of (al) and (a2) to be reacted in accordance with the
present invention.
With regard to the reaction, care should be taken to ensure that the
reaction conditions and process conditions observed are those under which the
30 cyclocarbonate groups of component (al) can preferably only react with the
primary amino groups of component (a2). This can be achieved by known
methods, without corresponding reactions also taking place with any secondary
amino groups which may be present, which are considerably slower to react.
~13874~
In addition, excessively high temperatures should be avoided, in order to
prevent the elimin~tion of urethane structures from polyalkylenepolyamines
to form cyclic urea derivatives.
Examples of suitable inert solvents include aromatic hydrocarbons such
5 as xylene and toluene, alcohols such as butanols and pentanols, and glycol
ethers such as methoxyethanol, ethoxyethanol, methoxypropanol, butoxy-
ethanol, methoxybutanol, glycol dimethyl ethers and diglycol dimethyl ethers
and the like. The solvents to be chosen preferably are those which can be
removed readily by distillation after the reaction has taken place or which do
10 not interfere subsequently with the aqueous formulation. In the latter case,
the solvent should only be used in a quantity which is sufficient to lower the
viscosity to a manageable level. Because of their potential reactivity with the
components, esters and ketones are of only limited suitability.
The reaction temperature should be sufficient to sufficiently react the
components and preferably is within the range from 50C to 150C, its lower
limit being determined by solubility and viscosity and its upper limit by the
tendency of secondary reactions and follow-on reactions and by the boiling
point of the solvent. It is preferred to operate the reaction at temperatures
between 80C and 130C. Catalysts typically are not required for this reaction
20 but may be used if desired. For instance, reactions between carbonates and
primary amines proceed rapidly even at room temperature; however, relatively
high temperatures are required for the systems described, since the products
often have a high viscosity even in solvents.
The chosen relative proportions of (al) and (a2) must ensure that
25 amino-functional reaction products are formed which, via these functions, areable to react with the glycidyl groups of an epoxy resin (B). These groups are
preferably primary amino groups, of which at least one, but even better two
or more, should be present per molecule of the aminourethane. By varying
the relative proportions of components, it is possible to obtain products whose
30 character ranges from oligomeric to polymeric, with oligomers being
particularly preferred. Thus relative proportions of carbonate (al) to
polyamine (a2) in the region of 1 mol of polyamine (a2) per mole of
carbonate groups of component (al) are to be employed for the formation of
21 387~
oligomers. The skilled artisan is capable of varying the relative proportions
of components to achieve the desired product.
The aminourethanes (A) obtained in this manner can be reacted alone
or, if desired, in combination with further amines (a2), with water-dilutable
epoxy resins (B); the reaction products can be used as curing agents for
aqueous epoxy resin systems, preferably for curing at room temperature
and/or lower temperatures, generally in a molar ratio of epoxide groups to
amine hydrogen atoms of from 1:0.75 to 1:2Ø
The polyepoxy compounds useful as component (B) can be the same as
the compounds described under (al), and preferably include polyglycidyl
ethers of polyhydric alcohols or phenols (polyols).
The water-dilutable epoxy compounds (B) can preferably be condensa-
tion products of
(bl) aliphatic polyhydroxy compounds having a molar mass of
from 200 to 20,000 g/mol; and
(b2) epoxides having at least two epoxide groups and an
epoxide equivalent weight of from 100 to 2000 g/mol, wherein the ratio of the
number of hydroxyl groups of (bl) to the number of epoxide groups (b2)
preferably is from 1:3.5 to 1:10, and more preferably from 1:4 to 1:8.
The polyols useful in the present invention preferably include
polyetherpolyols (polyalkylene glycols) having weight-average molar masses
(Mw; determined by gel permeation chromatography using a polystyrene
standard) of preferably between 600 and 12,000 g/mol, in particular from 2000
to 8000 g/mol, and OH numbers which are expediently from 10 to 600 mg of
KOH/g, preferably from 15 to 120 mg of KOH/g. These polyetherpolyols
preferably possess only terminal, primary OH groups. Examples which may
be mentioned in this context are block copolymers of ethylene oxide and
propylene oxide, and polyethylene glycols, polypropylene glycols and
polybutylene glycols, it also being possible to employ mixtures of the
respective polyalkylene glycols. Polyethylene glycols are preferably used.
However, it also is possible to employ any other polyols described as
compounds (al).
21387~
The hydrophilic condensation products (B) can be synthesized by, for
example, reacting hydrophilic epoxy compounds (for example polyethylene
glycol diglycidyl ethers) with hydrophobic polyols (e.g., bisphenol A) or,
preferably and alternatively, reacting hydrophobic epoxy compounds (e.g.,
bisphenol A diglycidyl ether) with hydrophilic polyols (e.g., polyethylene
glycol). In this context reference may be made to EP-A 0 000 605 and
application DE-A 43 09 639, which describe in detail the preparation of
hydrophilic epoxy resins (B). Those skilled in the art are capable of carrying
out the methods described in the aforementioned documents to prepare epoxy
resins (B).
The epoxy-amine adducts according to the invention can be used alone
or as a mixture with aqueous curing agents or amines which are known;
suitable examples are all of the epoxy-amine adducts, Mannich bases,
polyamidoamines and amines described as compounds (a2), which may be
used alone or in the form of mixtures. Suitable Mannich bases can be
prepared by condensation of polyamines, preferably diethylenetriamine,
triethylenetetramine, isophoronediamine, 2,2,4- and/or 2,4,4-
trimethylhexamethylenediamine, 1,3- and 1,4-bis(aminomethyl)cyclohexane,
especially meta- and para-xylylenediamine, with aldehydes, preferably
formaldehyde, and mono- or polyhydric phenols which have at least one ring
position which is reactive toward aldehydes, for example the various cresols
and xylenols, para-tert-butylphenol, resorcinol, 4,4'-dihydroxydiphenylmethane
and 2,2-bis(4'-hydroxyphenyl)propane, and preferably phenol.
Polyamidoamines which can be used to cure the epoxy resin dispersions
according to the invention can be obtained by, for example, reacting
polyamines with mono- or polycarboxylic acids, for example dimerized fatty
acids. Preference is given to employing as amine curing agents, in addition
to the abovementioned systems, water-soluble polyoxyalkylenediamines and
polyoxyalkylenepolyamines, and also readily water-dispersible curing agents as
described in, for example, EP-A 0 000 605.
The preparation of the curing compositions according to the invention
can be carried out by various methods; all of these processes are included in
21387~
11
this invention. Variants which are particularly preferred and are to be
mentioned in particular include the following:
(I) A polyepoxy compound (al) is taken as an initial charge and reacted
with carbon dioxide to yield the carbonate (al). Further reaction then
is carried out with an initial quantity of an amine (a2), which is
employed in excess, if desired, in the described manner to yield the
aminourethane (A), it being possible if desired for suitable inert solvents
to be present. This is followed, if desired, by the addition of a second
quantity of amine whose composition may be identical or different to
that of the first quantity of amine. The product, which exclusively
comprises aminourethane (A) or, if desired, comprises a mixture of (A)
and excess amines, then is reacted with hydrophilic epoxy resin (B).
Care should be taken to ensure that sufficient free amino groups
remain, which are used for curing.
(II) Isolated aminourethanes (A) are homogenized together with amines
(al) and, if desired, inert solvents and then reacted with a
substoichiometric amount of hydrophilic epoxy resin (B) in such a way
that a sufficient quantity of free amino groups remain for curing.
(III) The hydrophilic epoxy resin (B) is reacted with an excess of polyamines
(a2), and the epoxy-amine adduct mixed with unreacted amines is
reacted with carbonate compounds (al) in the manner described such
that sufficient free amino groups for curing remain.
The urethane-cont~ining epoxy-amine adducts obtained by the various
processes may, if required, be admixed with water-dilutable solvents and
further curing compositions, in order to formulate an appropriate curing
composition.
Suitable epoxy resin components for the formulation of cold-curing
binders are all aqueous epoxy resin systems, very good properties being
achieved, in particular, by using the nonionically stabilized solid-resin
21387~
- 12
dispersions described in DE-A 36 43 751. The ratio of amino groups to
epoxide groups in the corresponding binders is between 5:1 and 1:5, preferably
between 1.5:1 and 1:1.5.
The sandability of correspondingly formulated sanding fillers is
5 outstanding, and this quality cannot be achieved with the conventional or
aqueous epoxy systems known hitherto. It is thus possible for the first time
to retain the abovementioned good properties of aqueous epoxy resin systems,
in the case of curing with aminourethanes in combination with conventional
aqueous curing agents, while at the same time achieving a marked reduction
10 in thermoplasticity, leading to a considerable improvement in both the wet-
and dry-sandability.
Examples
The examples which follow are intended to illustrate the invention but
not to limit it. In particular, it is not possible to illustrate every conceivable
15 process variant by a corresponding example. In addition, those skilled in the art appreciate that various modifications may be made to the invention
without departing significantly from the spirit and scope thereof.
Preparation of aminourethanes (A)
and curing compositions
The following abbreviations are used throughout the examples:
Abbreviations of amines
EDA ethylenediamine
mXDA meta-xylylenediamine
DMAPA N,N-dimethylaminopropylamine
DETA diethylenetriamine
IPDA isophoronediamine
21387~
13
Abbreviations of solvents
BuGl butylglycol
MeGl methylglycol
BuDiGl butyldiglycol
IPP isopropoxypropanol
BZA benzyl alcohol
Abbreviations of further terms
BDC see Example 1.1
AN amine number (mg of KOH/g)
EQ epoxide equivalent weight (g/mol)
m.p. melting point
1. Preparation of isolated aminoureth~res (A)
1.1: BDC (229 g, reaction product of bisphenol A diglycidyl ether with
carbon dioxide until complete disappearance of the epoxide groups) were
dissolved in 190 g of a 1:1 mixture of BuGl and IPP at 140C. The
temperature was reduced to 125C, 25.8 g of DETA were added slowly to the
clear solution over the course of 15 minutes, and the mixture was held at
120C until a constant AN of about 27 had been reached. The temperature
then was reduced to 110C, and 30.1 g of EDA were added over the course
20 of 20 minutes. During this addition a slight exothermic response was observedand the viscosity rose. When addition was complete the AN was 88. Volatile
components then were distilled off in vacuo (about 20 torr) up to a m~ximllm
of 140C (about 159 g of these components were present in the initial fraction,
which contained amine) giving 312 g of product as residue; AN 97, purity
25 66~o.
~1387~
14
1.2: BDC (229 g) were heated to 120C together with 120 g of MeGl
and maintained at this temperature with thorough stirring. The solution soon
became almost clear, and then 128 g of IPDA were added at a uniform rate
in the course of 10 minlltes at 100C and the temperature was m~int~ined
5 until the AN had reached a constant value of 62. The solvent (first rllnnings
74 g) then was distilled off in vacuo up to a m~ximllm of 120C to such an
extent that the residue just remained still stirrable, to give 395 g of a product
having an AN of 73 (theoretically 79) which still contained 8% solvent. The
m.p. was 51C.
1.3: A solution of BDC prepared as described in Example 1.2 was
reacted first with 25.8 g of DETA to an AN of 35 and then with 85.2 g of
IPDA to an AN of 91. After volatile compounds had been distilled off there
remained 359 g of product having an AN of 114, 6% residual solvent and m.p.
56C.
1.4: A solution of BDC prepared as described in Example 1.2 was
reacted first with 15.0 g of EDA to an AN of < 4 and then with 85.2 g of
IPDA to an AN of 65. After volatile compounds had been distilled off there
remained 353 g of product having an AN of 81, 5% residual solvent and m.p.
SOC.
1.5: A solution of 916 g of BDC in 404 g of MeGl, prepared as
described in Example 1.2, was reacted first with 103 g of DETA until the AN
was 39 and then with 120 g of EDA until the AN was 106. After volatile
compounds had been distilled off there remained 1176 g of product having an
AN of 116 and 22~ residual solvent, m.p. below room temperature.
1.6: A solution of BDC prepared as described in 1.2 was reacted with
102 g of mXDA until the AN was 65. After volatile compounds had been
distilled off there remained 364 g of product having an AN of 77, 9~o residual
solvent and m.p. 51C.
~ 1 3 8 r~ 4 ~
1.7: A solution of BDC prepared as described in Example 1.2 was
reacted first with 25.8 g of DETA until the AN was 40 and then with 68 g of
mXDA until the AN was 101. After volatile compounds had been distilled off
there remained 331 g of product having an AN of 125, 4% residual solvent
5 and m.p. 51C.
1.8: A solution of BDC prepared as described in Example 1.2 was
reacted first with 15.0 g of EDA until the AN was < 4 and then with 68 g of
mXDA until the AN was 69. After volatile compounds had been distilled off
there remained 318 g of product having an AN of 86, 4% residual solvent and
10 m.p. 58C.
1.9: A solution of BDC prepared as described in Example 1.2 was
reacted with 60.0 g of EDA until the AN was 76. After volatile compounds
had been distilled off there remained 369 g of product having an AN of 82,
11% residual solvent and m.p. 53C.
1.10: A solution of BDC prepared as described in Example 1.2 was
reacted with 103 g of mXDA until the AN was 171. After volatile compounds
had been distilled off there remained 420 g of product having an AN of 203,
1.5% residual solvent and m.p. 42C.
1.11: A solution of 229 g of BDC prepared in 95 g of BZA was reacted
first with 25.8 g of DETA until the AN was 35 and then with 30.0 g of EDA
until the AN was 105. About 380 g of a product were obtained which had an
AN of 103, contained 25% BZA and was highly viscous at room temperature.
1.12: A solution of 229 g of BDC prepared in 95 g of BuGl was
reacted first with 25.8 g of DETA until the AN was 34 and then with 30.0 g
of EDA until the AN was 106. About 380 g of a product were obtained which
had an AN of 102, contained 25% BuGl and was highly viscous at room
temperature.
2138748
16
1.13: A solution of 229 g of BDC prepared in 95 g of BuDiGl was
reacted first with 25.8 g of DETA until the AN was 39 and then with 30.0 g
of EDA until the AN was 107. About 380 g of a product were obtained which
had an AN of 104, contained 25% BuDiGl and was highly viscous at room
5 temperature.
1.14: A solution of BDC prepared as described in Example 1.2 was
reacted first with 15.0 g of EDA until the AN was < 4 and then with a
mixture of 22.6 g of EDA and 16.3 g of DMAPA until the AN was 75. After
volatile compounds had been distilled off there remained 287 g of product
10 having an AN of 87 and a m.p. of 57C.
1.15: A solution of 229 g of BDC in 100 g of MeGl was reacted with
111 g of XJeffamin EDR-148 until the AN was 63. The solvent was distilled
off to give 440 g of product having an AN of 102 and a MeGl content of 6%.
1.16: A solution of 229 g of BDC in 100 g of MeGl was reacted with
134 g of mXDA until the AN was 120. The solvent was distilled off to give
463 g of product having an AN of 145 and a MeGl content of 7%.
2. Preparation of the curing composition
2.1: IPDA, (43.8 g), 35.2 g of mXDA and 131.6 g of the product from
Example 1.12, containing 25% BuGl, were heated to 70C with thorough
stirring. The mixture was then clear, had an AN of 95 and was reacted with
155.2 g of an epoxy-functional emulsifier (EQ value 420 g/eq) as described in
DE-A 43 10 198 (Example I.4, Hoechst), the reaction being markedly
exotherrnic. The mixture, which was still clear, was adjusted to a solids
content of 80% with 59 g of water and had an AN of 166 and a viscosity at
25C of about 28,000 mPas. The product contained 7.8% BuGl.
2.2: BDC (149 g) were added to 62 g of BuGl at 100C and the
mixture was reacted with 16.8 g of DETA until the AN was 40 and then with
2138748
17
EDA until the AN was 121. The mixture was then cooled to 70C and 82.5
g of IPDA and 66.3 g of mXDA were added, followed by 292 g of the
polyepoxide described under 2.1. When the exothermic reaction had subsided,
the temperature was maintained at 70C for one hour more and the product
5 was adjusted to a solids content of 80% with 96 g of water. The clear product
contained 8% BuGl and had an AN of 181 and a viscosity at 25C of 36,000
mPas.
2.3: BDC (183 g) were suspended in 61 g of BuGl at 115C and, at
this temperature, a mixture of 65.8 g of mXDA and 116 g of IPDA was
10 metered in over the course of one hour. The now virtually clear batch had an
AN of 202. The polyepoxide described under 2.1 (144 g) was added at 75C
in the course of 30 min and the batch, which was turbid, was diluted with
water to a solids content of 80%. The clear solution was highly viscous and
had an AN of 136.
2.4: BDC (192 g) were homogenized together with 52 g of BuGl and
165 g of IPDA and the mixture was maintained at 125C until the AN had
reached 154. The highly viscous product was cooled to 80C, and n-butyl
glycidyl ether was added at a uniform rate over the course of 20 min, a slight
exothermic response occurring. A condensation product of PEG 1000 and a
mixture of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether (175
g EQ 415) were added, followed by 30 g of mXDA. The mixture was cooled
to 70C and diluted with 50 g of 2-propanol and 37 g of water to give a clear,
highly viscous liquid having an AN of 117.
2.5: BDC (149 g) were suspended in 62 g of BuGl at 120C and were
reacted first with 17 g of DETA until the AN was 40 and then with 20 g of
EDA until the AN was 119. The product was cooled to 70C and then 82.5
g of IPDA and 66.5 g of mXDA were added, followed by 292 g of the
polyepoxide described under 2.1 which, however, had this time been
condensed to an EQ value of 410. After addition of water a clear, highly
viscous product was obtained having an AN of 204.
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3. Examples of application as sanding fillers
3.1 Production of a filler
An aminourethane corresponding to Example 2.1 (48.5 g) and 350 g of
fully deionized water were mixed thoroughly with one another. A
S commercially available polyurethane thickener (13 g) and 1.3 g of a corrosion
inhibitor were added to the mixture and were likewise mixed in thoroughly.
The following pigments and fillers were dispersed in this mixture in a
customary manner:
32 g of silicon dioxide;
114 g of barium sulfate;
95 g of alllmimlm silicate;
104 g of titanium dioxide;
S g of yellow iron oxide;
The resulting polyamine component was admixed shortly before
application with 238 g of a commercial aqueous epoxy resin (SO~ Beckopox
EP 384 from Hoechst AG), and the two components were mixed intensively
by stirring.
3.2 Production of a filler
(Comparative Example)
The polyamine component was prepared in accordance with Example
2.2, but with the difference that 37 g of the commercially available polyamine
curing agent were mixed with 334 g of fully deionized water without the
addition of aminourethane.
Application of the coating composition
The filler coating compositions were each sprayed onto steel substrates,
coated beforehand with a cataphoretic primer, and were dried at 60C for 1/2
hour.
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19
The properties of the resulting coatings are summarized in the following
table:
Filler 3.1Filler 3.2
(Comparative)
Coat thickness in ,um 30/130 30/60
Wet sanding + + / + + + /
S Dry sanding + + / + + + /
+ + very good
+ good
- poor
-- very poor
The invention has been described in detail with reference to preferred
embodiments and examples. Various modifications of the invention are
readily apparent to those skilled in the art. In addition, all of the
aforementioned documents are incorporated by reference herein in their
entirety.
