Note: Descriptions are shown in the official language in which they were submitted.
X28~ 23443-2~0
The present invention relates to epoxy resin diammonium
salt emulsions comprising a liquid epoxy resin, a latent curing
agent and an emulsifier. Epoxy resins have many uses in the con-
struction field (cf., for example, B.H. S~ECHTLING, "Bauen mit
KunststoEfen", Carl-Hanser Verlag, Munich 1973). In addition to
pure epoxy resin mortars used for coatings and primers, for
example, there are many interesting applications in the construc-
tion field for epoxy resin cement mortars because of their good
adhesion, their good shrinkage behaviour and their ability to
retain water.
An essential pre-requisite for the processing of epoxy
resins i5 that the resin and the curing agent react completely
with each other, within a reasonable time, under the a-tmospheric
conditions at the site.
A mixture of bonding agen-ts is described in Gérman
Offenlegungsschrift 28 40 874 and consists of a hydraulic binder,
an epoxy resin (the adduct oE a polyamine and an epoxy compound),
water and, if necessary, reactive diluents, pigments and other
auxiliary substances. This mixture is particularly suitable for
restoring damaged reinforced-concrete parts because the use of a
primer, to provide protection against corrosion, is unnecessary
with this mixture.
A disadvantage of this two-component system is that, due
to its limited stability, it must be prepared at the building site
and used within a relatively short time (about half an hour). The
hardener : epoxy resin ratio is known to be of critical impor-
tance. Thus, the method cited, which requires rapid, very careful
~,~
I.
~2~89S~)
and thorough mixing if the quality is not to suffer has practicaldisadvantages.
As described in United States Patent 3,926/886, it is
better to start with an epoxy resin diammonium-acetate or -formate
emulsion consisting of a liquid epoxy resin, water and a substi-
tuted diammonium salt and to effect curing in the presence of
cement.
In the method described in United States Patent
3,926,886, the diammonium salt has two functions to perform.
Firstly, it releases the basic diamine after reacting with the
alkaline-reacting cement, the diamine then curing the epoxy resin;
secondly, it fulfills the function of an emulsifier. However, the
stability of this emulsion is not assured, especially if the pro-
cess must be carried out under extreme atmospheric conditions. It
is therefore already proposed, in United States Patent 3,926,886,
to add to the mixture up to 15% of a commercially available emul-
siEier, but even after this, the stability of the emulsion is a
critical factor.
another unsatisfactory feature is that the amine compo-
nents used must be specific diamines containing ether groups, ofthe Eormula: -
R1 - O - R2 - NH - R3 - NH2,
where R1 represents an alkyl residue with at least 8 carbon atoms
and R2 and R3 are lower alkyl residues with 2 to 4 carbon atoms.
It is, however, desirable to be able to use more readily available
diamines for the production of emulsions. In contrast to the
diamines of United States Patent 3,926,886, most of the readily
- 2 -
~ZZ8950
available diamines are miscible with water in any proportion.
The formates and acetates thereof cannot be emulsified with con-
ventional emulsifiers, such as fatty alcohol ethoxylates, alkyl
sulphonates or alkyl phosphoric-acid semi-esters. On the other
hand, only homogeneous, stable emulsions are capable of ensuring
cold-curing of uniform quality of the liquid epoxy compounds
used.
It is therefore a purpose of the invention to develop
formulations which will make it possible to produce, with diamines
1 n suitable for curing epoxy resins and which themselves have no
emulsifying action, stable aqueous epoxy-resin diammonium-salt
emulsions, useful in the construction field.
Thus, in accordance with an aspect of the present invention,
there is provided an epoxy resin diammonium salt emulsion compris-
ing a liquid epoxy resin, a latent curing agent, an emulsifier and
water, wherein:
a) the emulsifier is a primary aliphatic alcohol of 8 to 14
carbon atoms or its adduct with up to 10 ethylene-oxide groups;
and
b) the latent curing agent is a reaction product obtained by
complete neutralization with an acid consisting of or containing
oxalic acid of a diamine of the formula I or II;
H2N - CH2 - R - NH2 (I)
H2N - R - CH2 - R - NH2 (II)
wherein R is selected from the group consisting of a substituted
alkylene, a cycloalkylene residue with 6 to 9 carbon atoms and an
aralkylene residue with 7 to 9 carbon atoms.
, - 3 -
~2~
23443-260
In accordance with another aspect of the present
invention there is provided a method for producing an epoxy resin
diammonium salt emulsion described above which comprises:
a) adding sufficient acid to an aqueous solution of
the diamine to neutralize the solution,
b) adding khe emulsifier and
c) adding the liquid epoxy resin.
In accordance with a further aspect of the invention,
there is provided a method for sealing fresh concrete surfaces
for improving the water-retaining ability of the concrete, which
comprises coating the surface with the epoxy-resin diammonium-
salt emulsion.
In accordance with a further aspect of the present
invention, there is provided an epoxy resin cement mortar mixture
comprising the epoxy resin diammonium salt emulsion and cement
mortar. In accordance with a still further aspect of the present
invention, there is provided with an epoxy resin mortar compris-
ing the epoxy resin diammonium salt emulsion and a hardening
mixture containing an alkaline-reacting substance. The amount
of the epoxy resin diammonium salt emulsion in the epoxy resin
cement mortar mixture or in the epoxy resin mortar is such that
the epoxy resin cures under atmospheric conditions, preferably
10 to 30~ by weight based on the mortar or the hardening mixture.
Within the scope of this application, emulsions mean
not only the two-phase systems produced by dispersion of one
liquid phase in another liquid phase, but also those systems in
which a solid phase is dispersed in a liquid phase, and all
-- 4
~Z~39~;~
23443-260
transitions of these two systems.
Thus, the amine component is not to react, us described
for example in EP-Al-00-43 463, with epoxy resins or with adducts
- 4a -
, ::
~Z~3g50
which are rendered water-soluble and dispersible by addition of
acid, at an elevated temperature. Instead, an emulsion is to be
produced from a diammonium salt and an epoxy resin, in which the
curing process is initiated after the addition of an alkaline-
reacting substance.
According to the present invention, the emulsions may be
used in epoxy resin mortars and also in epoxy resin cement mor-
tars. They are also suitable for sealing fresh concrete surfaces
for the purpose of improving the water-retaining ability of the
concrete.
Diamines which are components of the latent curing agent
are of formula I or II:
H2N - CH2 - R - NH2 (I)
2N - R - CH2 - R - NH2 (II)
wherein R is a substituted alkylene or a cycloalkylene residue
with 6 to 9 carbon atoms or an aralkylene residue with 7 to 9
carbon atoms. Particularly suitable are tolylene residues and
alkylene and cyclohexylene residues substituted by one to three
methyl groups. It is preferable to use 2,2,4-trimethylhexamethyl-
ene diamine (TMD), xylyl-diamines, or diamines containing one or
two cyclohexane rings, for example 3-aminomethyl-3,5,5-trimethyl-
cyclohexylamine (isophorone-diamine, IPD) or 4,4'-diamine-3,3'-
dimethyldicyclohexylmethane.
Up to 25% by weight of the oxalic acid may be replaced
by acetic acid. The oxalic acid may also be replaced by aliphatc
dicarboxylic acids with 3 to 6 carbon atoms or by isomers of
phthalic acid, but the acid mixture must contain at least 40% by
-- 5
3950
weight of oxalic acid. Aliphatic dicarboxylic acids, for example
malonic acid or adipic acid, unsaturated acids, for example fumar-
ic acid, or acids containing hydroxyl groups, for example tartaric
acid, can be used.
IJinear primary alcohols with to 14 carbon atoms, and
mixtures thereof, are suitable as the emulsifiers. Also suitable
are adducts of these alcohols with up to 10 ethylene-oxide groups.
lauryl alcohol is particularly preferred. If necessary, the sta-
bility of the emulsions can be improved by addition of lauric
acid. Addition of from 10 to 25~ of emulsifiers, in relation to
the amount of epoxy resin used, have been found to be satisfac-
tory.
Liquid epoxy-compounds suitable for cold-curing are
mainly reaction products of epichlorhydrin or glycidol and
2,2-bis(4-hydroxyphenyl)alkanes. The precise chemical structure
of commercially obtainable epoxy resins, for example EUREPOX* by
Schering, Berlin or XUTAPOX* VE 2913 by Bakelite GmbH, Duisburg,
is unknown.
mulsions are produced by preparing an aqueous solution
of the diamine. The amount of diamine is governed by data from
the epoxy resin manufacturer, for example the epoxy value of the
epoxy resin used or the ratio of the mixture of resin and curing
agent. The most satisfactory amount of water for an emulsion
depends mainly upon the type of diamine. In the case of diamines
with a relatively small number of carbon atoms for example 7,
*Trade Mark
- 6 -
3~XZ8~5~
less water is needed than for diamines with a larger number of
carbon atoms, for example 12. The optimal amount may be easily
determined in comparative test by varying the amount of water
between 30 and 130% of the amount of epoxy resin used.
Enough acid is then added to the aqueous solution of
diamine for complete neutralization. If the reaction heat is
considerable, it is desirable to cool the reaction mixture. The
emulsifier is then stirred into the solution which is at room
temperature. The epoxy resin is then slowly added to the mixture,
which is again at room temperature, with rapid stirring. Stirring
is continued for 0.5 to 1.0 hours after all of the epoxy resin has
been added. In this way, emulsions are obtained which are stable
at a room temperature for months. If phase separation occurs, the
mixtures may be rapidly homogenized again by renewed stirring.
The invention is further illustrated in the following
examples.
a) Production of emulsions.
(Amounts of oxalic acid always relate to the dihy-
drate).
Example 1.
105 parts by weight of water and 28.2 parts by weight of
isophoronediamine (IPD) were placed in a flat-bottomed flask
having a magnetic stirrer. 10.2 parts by weight of oxalic acid,
4.5 parts by weight of acetic acid, and 7.5 parts by weight of
phthalic acid were added to this solution. After the reaction
mixture had cooled to room temperature, 6.0 parts by weight of
lauryl alcohol and 17.4 parts by weight of luric acid, in por-
- 7 -
~2;~:~950
tions, were stirred into the mixture. Thereafter, 120 parts by
weight of epoxy resin RUTAPOX* VE 2913 were slowly added to the
mixture with rapid stirring (at about 1,000 r.p.m.). Stirring was
continued, at the same r.p.m., for another hour. This produced a
low-viscosity emulsion which showed no change after two months.
Comparison example A.
The procedure was as in Example 1, but in this case
neutralization of the diamine was effected entirely with 21.6
parts by weight of acetic acid. The emulsion obtained kroke down
after a few mintutes.
Comparison example B.
The procedure was as in Example 1, but in this case
neutralization of the diamine was effected entirely with 16.2
parts by weight oE formic acid. The emulsion obtained broke down
after a few minutes.
Example 2.
A stable, low viscosity emulsion was produced, as des-
cribed in Example 1, from 90 parts by weight of water, 28.2 parts
by weight of IPD, 19.8 parts by weight of oxalic acid, 3 parts by
weight of tartaric acid, 12 parts by weight of lauryl alcohol J and
120 parts by weight of epoxy resin RUTAPOX* VE 2913. The slight
segregation arising after three months of storage was eliminated
by stirring the mixture.
Example 3.
A stable, low viscosity emulsion was produced, as
* Trade Mark
- 8 -
o
described in Example 1, from 15 parts by weight of water, 4.4
parts by weight of 2,2,4-trimethylhexamethylene-diamine (TED), 3.5
parts by weight of oxalic acid, 2.0 parts by weight of lauryl
alcohol, and 20 parts by weight of epoxy resin RUTAPOX* VE 2913.
Example 4.
A stable, medium viscosity emulsion was produced, as
described in Example 1, from 20 parts by weight of water, 6.6
parts by weight of 4,4'-diamino-3,3'-diemthyldicyclohexyl-methane,
- 3.8 parts by weight of oxalic acid, 2.0 parts by weight of lauryl
alcohol, and 20 parts by weight of epoxy resin ~UTAPOX* VE 2913.
Example 5.
A stable emulsion was produced, as described in Example
1, from 10 parts by weight of water, 3.8 parts by weight of
xylylene~diamine (a mixture of isomers), 3.6 parts by weight of
oxalic acid, 2.0 parts by weight of lauryl alcohol, 2.0 parts by
weight of lauric acid, and 20 parts by weight of RUTAPOX * VE
2913.
Example 6.
A low viscosity emulsion was produced, as described in
Example 1, from 40 parts by weight of water, 9.4 parts by weight
of IPD, 3.2 parts by weight of fumaric acid, 3.5 parts by weight
of oxalic acid, 4.0 parts by weight of lauryl alcohol, 4.0 parts
by weight of lauric acid, and 40 parts by weight of epoxy resin
R~TAPOX* VE 2913.
* Trade Mark
,~
_ g _
~8g~0
Example 7.
A low viscosity emulsion was produced, as described in
Example 1, from 35 parts by weight of water, 9.4 parts by weight
of IPD, 3O5 parts by weight of oxalic acid, 4.1 parts by weight of
adipic acid, 2.0 parts by weight of lauryl alcohol, 2.0 parts by
eight of lauric acid, and 40 parts by weight of epoxy resin
RUT~POX* VE 2913.
Example 8.
A low viscosity emulsion was produced, as described in
Example 1, from 35 parts by weight of water, 9.4 parts by weight
of IPD, 3.5 parts by weight of oxalic acid, 2.9 parts by weight of
malonic acid, 2.0 parts by weight of lauryl alcohol, 2.0 parts by
weight of lauric acid, and 40 parts by weight of epoxy resin
RUTAPOX* VE 2913.
Example 9.
A low viscosity emulsion was produced, as described in
Example 1, from 35 parts by weight oE water, 9.4 parts by weight
of IPD, 1.5 parts by weight of acetic acid, 2.5 parts by weight of
phthalic acid, 3.5 parts by weight of oxalic acid, 2.0 parts by
weight oE lauryltriglycol, 2.0 parts by lauric acid, and 40 parts
by weight of epoxy resin RUTAPOX* VE 2913.
Example 10.
A low viscosity emulsion was produced, as described in
Example 1, from 15 parts by weight of water, 4.7 parts by weight
of IPD, 0.5 parts by weight of tartaric acid, 3.3 parts by weight
of oxalic acid, 2.0 parts by weight of lauryl alcohol, 0.5 parts
* Trade Mark
- 10 -
~:28950
by weight of a mixture of dodecyl- and tetradecyl alcohol (ALFOL*
12/14) which had been reacted with 9 moles of ethylene-oxide, and
20 parts by weight of epoxy resin RUTAPOX* VE 2913.
Example 11.
A medium viscosity emulsion was produced, as described
in Example 1, from 12 parts by weight of water, 4.7 parts by
weight of IPD, 0.5 parts by weight of tartaric acid, 3.3 parts by
weight of oxalic acid, 2.0 parts by weight of lauryl triglycol,
and 20 parts by weight of epoxy resin RUTAPOX* VE 2913.
10 Example 12.
A stable emulsion was produced, as described in Example
1, from 10 parts by weight of water, 3.5 parts by weight of oxalic
acid, 4.7 parts by weight of isophorone-diamine, 1.5 parts by
weight of 2-ethylhexanol, and 20 parts by weight of epoxy resin
RUTAPOX* VE 2g13.
b) Production of epoxy resin cement mortars.
Example 13.
For the purpose of producing an epoxy resin cement
mortar, 100 parts by weight of Portland cement 35F were mixed with
20 45 parts by weight of water, 20 parts by weight of the emulsion
described in Example 1, and 485 parts by weight of filler (60
parts by weight of EFA filler, 170 parts by weight of sand HSE
2/3 mm, 170 parts by weight of sand 0/1 mm, 85 parts by weight of
sand 1/3 mm) (as in DIN 1164). Test specimens prepared from this
mixture were subjected to seven days of storage in a humid
* Trade Mark
~LZ;~895~
atmosphere and 21 days of storage at room temperature. Proper-
ties, measured in accordance with DIN 1164, amounted to 53.5 N/mm2
compressive strength and 8.67 N/mm2 tensile bending strength.
Example 14.
As described in Example 13, the mortar was produced from
100 parts by weight of Portland cement 35F with 60 parts by weight
of water, 23.4 parts by weight of the emulsion from Example 2, and
485 parts by weight of filler. The properties of the test speci-
mens, measured in accordance with DIN 1164, amounted to 43.8 N/mm2
compressive strength and 8.88 N/mm2 tensile bending strength.
c) Production of epoxy-resin mortars.
Example 15.
40 parts by weight of 0/1 mm sand were mixed with 15
parts by weight of the emulsion described in Example 1. 1.5 parts
by weight of a 50% caustic soda solution were incorporated in the
mass obtained producing a`homogeneous mortar capable of flowing
which cured to a solid, tack-free mass within 24 hours at a
temperature of 23C.
Example 16.
An epoxy resin mortar was produced, as described in
Example 15, from 40 parts by weight of 0/1 mm sand, 15 parts by
weight of the emulsion described in Example 1, and 0.65 parts by
weight of calcium hydroxide.
Example 17.
An epoxy resin mortar was produced, as described in
Example 15, from 40 parts by weight of 0/1 mm sand, 10 parts, by
weight of the emulsion described in Example 2, and 1 part by
- 12 -
Z289~
weight o:E a 50% caustic soda solution.
d) Sealing fresh concrete surfaces
Example 18
-
The surface of a fresh concrete test piece with a bulk
density of 2,380 kg/m3 (made from Portland cement 35F, water-
cement value 0.55 and ac3ditives) was coated with the emulsion
described in Example 1 (169 g/m2). After six weeks of room
storage, the bulk-density of the test piece was 2,292 kg/m3. In
the case of the reference test piece (with the same fresh bulk
density of 2t380 kg/m3), the surface of which remained untreated,
the bulk density after six weeks storage under the same conditions
was 2,262 kg/m3.
.
i
- 13 -
