Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21 75531
POLYURETHANE-POLYUREAS AND THEIR USE
3~ AS EMULSIFIERS
Background of the Invention
Field of the Invention
5The present invention relates to emulsifiers, to a
process for their preparation, and to their use in
aqueous dispersions of synthetic resins.
.Description of Related Art
The range of water-dilutable binder systems is as yet
10still incomplete, so that the replacement of all
conventional coating materials is currently still not
possible. In particular, the alkyd resins for the two-
component coating and stoving enamel sectors, which are
generally employed in the form of solutions in aliphatic
15or aromatic hydrocarbons, cannot at present be replaced
by aqueous systems of equal quality. The low solids
contents and the poor shelf life of aqueous self-
emulsifying alkyd resins, in addition to the no more than
moderate water resistance of the films, are the main
20points of criticism by users.
In contrast, externally emulsified aqueous disper-
sions of synthetic resins (e.g., alkyd resins) should
enable an ideal solution of the problem: in this case,
organic solvents can in general be dispensed with, and
25the use of emulsifiers permits a very good shelf life and
high solids contents to be obtained despite the high
molar mass of the synthetic resins. Despite this, even
these synthetic-resin dispersions have not acquired any
great importance to date, since no-one has as yet come up
30with an optimum solution to the problem of stabilizing
the dispersions without impairing the other properties.
Synthetic resins, such as alkyd resins and polyester
resins, are predominantly hydrophobic substances which do
not per se form stable dispersions in water. It is
35therefore necessary to add emulsifiers. In general,
emulsifiers are substances with an amphipathic structure,
21 7553 1
_ 2
i.e., their molecule consists of a hydrophobic and a
~ hydrophilic moiety. As a consequence of this structure,
the emulsifier molecules accumulate at the water-resin
interface, reduce the interfacial tension, and thus
enable the formation of very fine resin droplets in the
aqueous phase.
The synthesis of high molar mass polyurethane-
polyureas by chain extension in the aqueous phase is
known and is described, for example, in DE-A 26 24 442
and in EP-A 0 089 497, both being incorporated by
reference. The suitability of particular polyurethane-
polyureas as emulsifiers, however, was not known.
In the case of alkyd resin dispersions, the most
favorable results achieved up to now have been with
nonionic emulsifiers formed'by condensation of ethylene
oxide with octyl- or nonylphenol, i.e., in which the
hydrophobic moiety is composed of the alkylphenol radical
and the hydrophilic moiety of the polyethylene glycol
chain. Systems of this type are described in U.S.
Patents No. 3,223,658; No. 3,26g,967; and No. 3,440,193;
and in the Laid-Open Specifications DD 88 833 and
DE-A 27 54 091. Emulsifiers of this kind, added in
quantities of from 5 to 10%, produce alkyd resin
dispersions of serviceable stability. The disadvantage
is that these emulsifiers are of relatively low molar
mass and consequently function as "internal plasticizers"
in the alkyd resin film.
German Laid-Open Specifications DE-A 27 54 141,
27 54 092 and 24 40 946 describe alkyd resin dispersions
which are stabilized in the aqueous phase with the aid of
emulsifiers comprising polyethylene glycols, fatty acids
and/or allyl ethers.
EP-A 0 501 247 describes olefinically unsaturated
polyurethanes comprising a ~,y-ethylenically unsaturated
ether alcohol component and their use as reactive emulsi-
fiers. They are principally employed as emulsifiers for
unsaturated polyester resins, but are unsuitable for
alkyd resins.
3 21 75531
.
Because of their double bonds, these emulsifiers can
be incorporated into the film during oxidative drying,
thereby making it possible to obtain films of enhanced
water resistance. Owing to a lack of reactive groups,
5they are unsuitable for stoving and for two-component
applications. In addition, the low molar mass of these
emulsifiers permits limited migration of the emulsifiers
in the film, impairing the properties of the film formed.
A further problem of these alkyd resin emulsions, in
10addition to their slow drying, is poor pigmentability: it
-is not possible by the methods described above to obtain
glossy highly pigmented films.
Summary of the Invent;on
An object of the invention was therefore to develop
15emulsifiers which are able to stabilize dispersions in
water of synthetic resins, such as those crosslinkable by
melamine resin and isocyanate, and which do not adversely
affect the film properties, especially in relation to
gloss, reactivity and resistance to chemicals, weather
20and water.
Another object of the present invention, was to find
aqueous coating systems which stand out from the known
prior art in terms of improved properties, especially in
respect of reactivity, film hardness, pigmentability, and
25shelf life.
Surprisingly, these objects have been found to be
achievable using polyurethane-polyurea emulsifiers
bearing hydroxy-functional polyesters as their hydro-
phobic moiety.
30It has been possible to achieve these objects by the
provision of the hydrophilic polyurethane-polyureas
described in more detail below and by their use, which is
likewise described in more detail below.
In accordance with these objectives, there has been
35provided aqueous polyurethane-polyureas which are obtain-
able by reaction of:
4 21 75531
.
(a) a polyisocyanate component, comprising at least
one organic polyisocyanate; with
(b) at least one isocyanate-reactive
polyesterpolyol which can be prepared from
(i) one or more dicarboxylic acids
(ii) one or more diols and
(iii) if desired, one or more
polyfunctional components whose
functional groups are selected from
hydroxyl and carboxyl groups, and
(iv) if desired, a monofunctional carboxylic
acid;
(c) if desired, an isocyanate-reactive fatty acid
derivative;
(d) if desired, a compound of relatively high
functionality (functionality greater than 2)
whose functional groups are selected from
hydroxyl and carboxyl groups;
(e) a polyalkylene glycol component having a
number-average molar mass of from 750 to
10,000 g/mol; and
(f) a compound which contains active hydrogen atoms
and in which the active hydrogen reacts with
the NCO groups more quickly than water,
while maintaining a ratio of the number of isocyanate
groups to the number of isocyanate-reactive hydrogen
atoms, based on all of the starting components (a) to
(f), of from 0.6:1 to 1:1, wherein the proportion by mass
of polyester-derived structural units in the emulsifier
resin derived from (b) is from 10 to 60%, preferably from
12 to 40% and particularly preferably from 18 to 30%, and
the proportion by mass of polyalkylene glycol-derived
structural units in the emulsifier resin derived from (e)
is from 25 to 75%, preferably from 30 to 60%.
In accordance with the above objectives, there are
also provided methods of using of these polyurethane-
polyureas as reactive emulsifiers for curable synthetic
resins, which are not per se dispersible in water, in the
preparation of aqueous synthetic-resin dispersions.
21 75531
Further objects, features, and advantages of the
invention will become apparent from the detailed
description of preferred embodiments that follows.
Detailed Descr;ption of Preferred Fmbodiments
The polyurethane-polyureas of the present invention
can be used in any desired manner, for example, as
emulsifiers for any desired synthetic resin systems. For
example, as synthetic resins it is possible to use
~polyesters, polyurethanes, alkyd resins, and other
commercially available resins. The polyurethane-
polyureas of the invention are particularly suitable as
emulsifiers for alkyd resins.
As alkyd resins, any desired resins can be used. -It
is preferred to employ commercially available types,
which in certain cases are modified slightly in order to
increase the shelf life. In preparing the dispersions,
the resins are generally employed in the solvent-free
state, although it is also possible to add small quanti-
ties of solvent. In order to increase the shelf life,
the alkyd resin can be modified such that its acid number
is as low as possible. This modification can either be
carried out during the preparation of the alkyd resin, by
esterification with further alcohols, or the acid groups
can also be esterified subsequently, using an epoxide.
Suitable epoxide compounds include all monoepoxides,
which are described, for example, in the handbook
"Epoxidverbindungen und Epoxidharze" [Epoxide Compounds
and Epoxy Resins] by A.M. Paquin, Springer Verlag, Berlin
1958, Chapter IV, and in the "Handbook of Epoxy Resins"
by Lee and Neville, 1967, Chapter 2. Particularly
suitable are epoxidized fatty acids and, for example,
Cardura~ E10 (Versatic~ acid glycidyl ester from Shell
Chemical).
The polyurethane-polyureas according to the invention
are reaction products of the above-mentioned starting
components (a) to (f), preferably prepared using, per
mole of component (a), from 0.05 to 0.4 mol of
21 75531
.
component (b), from 0 to 0.3 mol of component (c), from
0 to 0.6 mol of component (d), from 0.1 to 0.8 mol of
component (e) and from 0.01 to 0.3 mol of component (f).
Particular preference is given to the use, per mole of
component (a), of from 0.05 to 0.25 mol of component (b),
from 0.05 to 0.25 mol of component (c), from 0.05 to
0.4 mol of component (d), from 0.2 to 0.6 mol of
component (e) and from 0.02 to 0.25 mol of component (f).
Component (a) comprises at least one organic polyiso-
cyanate. Suitable polyisocyanates include any organic
~polyisocyanates known per se from polyurethane chemistry
which contain isocyanate groups attached to aliphatic,
cycloaliphatic, and/or aromatic structures. The
polyisocyanates preferably have a molar mass of from 168
to 1,000 g/mol, more prefe~ably from 168 to 300 g/mol.
Diisocyanates are preferably employed. However, it is
also useful to replace up to 10% of the diisocyanates by
isocyanates with a functionality of three or more.
Preference is given to those isocyanate compounds in
which the isocyanate groups are attached to aliphatic
carbon atoms.
Suitable examples include 1,6-diisocyanatohexane
(HDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-
cyclohexane (IPDI), m-tetramethylxylylene diisocyanate
(TMXDI), 4,4'-diisocyanatodicyclohexylmethane, and also
4,4'-diisocyanatodiphenylmethane, its technical-grade
mixtures with 2,4'-diisocyanatodiphenylmethane and, if
appropriate, oligomers of these diisocyanates, and 2,4-
diisocyanatotoluene and its technical-grade mixtures with
2,6-diisocyanatotoluene.
Diisocyanates of the type given as examples are
preferred as component (a), but more highly functional
polyisocyanates such as, for example, biuret-,
isocyanurate- or urethane-modified polyisocyanates based
on the simple diisocyanates (mentioned by way of example)
are also suitable in principle. These derivatives
generally have a molar mass of up to 1,000 g/mol.
The preparation of such derivatives is described, for
example, in U.S. Patents No. 3,124,605; No. 3,183,112;
~1 75531
.
No. 3,919,218; and No. 4,324,879. These patents are
- hereby incorporated by reference in their entirety.
The isocyanate-reactive polyester polyol (b) can be
any such polymer, such as a hydroxy-functional polyester.
5 For example, useful polyesters, include linear or
branched polyesters, preferably having a hydroxyl number
(OHN) of from 30 to 180 mg/g and an acid number (AN) of
from 1 to 15 mg/g. They are built up by customary
polycondensation methods from dicarboxylic acids, diols
10 and, if desired, compounds of higher or lower
-functionality. The dicarboxylic acid component (i) can
be any desired and generally is selected from saturated
and unsaturated aliphatic, aromatic and cycloaliphatic
dicarboxylic acids, dimeric fatty acids, and mixtures of
15 two or more of these dicarboxylic acids. Examples of
such dicarboxylic acids include oxalic, malonic,
glutaric, pimelic, adipic, azelaic, sebacic, succinic,
fumaric, maleic and itaconic acid, 1,3-
cyclopentanedicarboxylic acid, l,2-cyclohexane-
20 dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-
cyclohexanedicarboxylic acid, phthalic, terephthalic and
isophthalic acid, tetrahydrophthalic acid, 2,5-
norbornanedicarboxylic acid, 1,4-naphthalenedicarboxylic
acid, 4,4'-biphenyldicarboxylic acid, 4,4'-sulfonyldi-
25 benzoic acid, and 2,5-naphthalenedicarboxylic acid, and
the esters and anhydrides thereof.
Preferred dicarboxylic acids (i) are phthalic,
isophthalic and terephthalic acid, tetrahydrophthalic
acid, adipic acid, succinic acid, succinic anhydride,
30 dimeric fatty acids, sebacic and azelaic acid, 1,3- and
1,4-cyclohexanedicarboxylic, and glutaric acid, and the
esters and anhydrides thereof.
The glycol (diol) component (ii) can be any desired
glycol, and, for example, can involve low molar mass
35 aliphatic, cycloaliphatic, or aromatic glycols. Examples
of the useful glycols include ethylene glycol, 1,2-
propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-propane-
diol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,2-
- 8 21 75531
cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-
- cyclohexanedimethanol, perhydrobisphenol A, p-xylylene-
diol, 2-ethyl- and 2-butylpropanediol.
As the optional polyfunctional component (iii) any
desired component is useful. In this context, Upoly-
functional" denotes a functionality in excess of 2.
Preferably, the component contains from 3 to 6 hydroxyl
and/or carboxyl groups. Preference is given to polyols
such as trimethylolpropane, trimethylolethane, glycerol,
ditrimethylolpropane, pentaerythritol and dipenta-
~erythritol; polycarboxylic acids such as trimellitic acid
(anhydride), pyromellitic acid (anhydride) and
benzophenonetetracarboxylic acid; hydroxycarboxylic
acids, such as dimethylolpropionic acid, dihydroxy-
propionic acid, dihydroxy~uccinic acid, malic acid,
tartaric acid, mesotartaric acid and dihydroxyhexanoic
acid; and polyanhydrides, as described, for example, in
DE-A 28 11 913, or mixtures of two or more of these
compounds. The proportion of the polyfunctional
component (iii) is preferably from 0 to 30 mol,
particularly preferably from 1 to 25 mol, per 100 mol of
all of components (i) to (iv).
Particular preference is given to the use of
trimethylolpropane as branching agent (iii).
The optional monofunctional carboxylic acid com-
ponent (iv) can include any such acid in a mole fraction
of 0 to 20 mol, preferably of 1 to 15 mol, and parti-
cularly preferably of of 2 to 10 mol per 100 mol of all
components. For example, it can comprise aliphatic
saturated and unsaturated monocarboxylic acids. Linear
unsaturated monocarboxylic acids having 10 to 22 carbon
atoms are particularly preferred, such as occur, for
example, in natural fats and oils. Specific examples of
suitable saturated fatty acids are 2-ethylhexanoic acid,
isononanoic acid, lauric acid, Versatic~ acid, or coconut
fatty acid.
Examples of suitable unsaturated fatty acids are
oleic acid, linoleic acid, and linolenic acid. Particu-
lar preference attaches to unsaturated monocarboxylic
9 21 75531
,
acids having an iodine number of more than 125 g/(100 g)
- and from 16 to 20 carbon atoms. These include, in
particular, fatty acids containing isolated unsaturation,
having two or three isolated double bonds of different
steric configuration, or corresponding fatty acids with
conjugated double bonds. Such fatty acids are present,
for example, in natural oils, such as linseed oil, soya
oil, safflower oil, cottonseed oil or castor oil,
sunflower oil, groundnut oil, wood oil and ricinene oil.
The unsaturated fatty acids obtained from these oils are
~linseed oil fatty acid, safflower oil fatty acid, tall
oil fatty acid, cottonseed fatty acid, groundnut oil
fatty acid, wood oil fatty acid, ricinenic fatty acid, or
sunflower oil fatty acid.
The fatty acids can a~lso be introduced into the
polyester (b) during synthesis by transesterification
from the respective oils.
The optional isocyanate-reactive fatty acid deriva-
tive (c) may be any such compound and generally contains
from 10 to 40 carbon atoms, at least one hydroxyl or
amino group, and optionally at least one, or two or more,
C=C double bonds. These derivatives are formed by
chemical transformation of the acid group, such as
reduction to the corresponding alcohol or reaction with
ammonia or amines to give the corresponding amides.
Simultaneous reduction and reaction with ammonia leads to
fatty amines. Other dervatives include ethoxylated fatty
alcohols, reaction products of fatty acids with epoxides
or polyamines, as exemplified below. Examples of these
fatty acid derivatives include fatty alcohols, such as
lauryl alcohol, stearyl alcohol, oleyl alcohol, linoleyl
alcohol or linolenyl alcohol. It is also useful to
employ ethoxylated fatty alcohols, generally containing
from 1 to 30, preferably 1 to 20, ethylene oxide units,
for example Genapol~ 0-020 (Hoechst AG). Other alcohols
which can be mentioned are those obtained by reaction
from an unsaturated acid and an epoxide, for example by
reaction of a fatty acid, such as linseed oil fatty acid
or soya oil fatty acid, with an epoxide, such as
~ ~5~3 ~
_, 10
Cardura~ E10 or other epoxides. It is also useful to
- employ partial esters of polyhydroxy compounds such as
glycerol, trimethylolpropane or pentaerythritol and also
partially hydrolyzed fats, for example Ligalub0 40/l
(fatty acid glycerol monoester from P. Graeven
Fettchemie). Also suitable, furthermore, are the fatty
amines, for example GenaminX grades (Hoechst AG).
The optional polyfunctional component (d) used, which
preferably contains 3 to 6 hydroxyl and/or carboxyl
groups, can be any such component, for example,
-trimethylolpropane, trimethylolethane, glycerol, ditri-
methylolpropane, pentaerythritol or dipentaerythritol.
Hydroxyalkanecarboxylic acids are similarly preferred,
especially bishydroxyalkanecarboxylic acids, such as
dimethylolpropionic acid, fior example, with the use-of
glycolic acid, malic acid, tartaric acid or 2,6-
dihydroxybenzoic acid also being possible. Other
possibilities are the mixtures of two or more of these
compounds.
Component (e) preferably comprises linear polyoxy-
alkylene glycols (polyether glycols) having a number-
average molar mass of from 750 to 10,000 g/mol,
preferably from 1,000 to 6,000 g/mol, in which at least
80 mol and preferably 100 mol of each 100 mol of alkylene
oxide units are ethylene oxide units.
The term polyethylene glycols is thus intended to
comprise not only actual polyethylene glycols whose
alkylene oxide units are exclusively ethylene oxide
units, but also polyalkylene glycols whose alkylene oxide
units are predominantly, i.e., to the extent of at least
80 mol per 100 mol, ethylene oxide units. "Mixed"
polyalkylene glycols of this kind are formed, for
example, by using mixtures of different alkylene oxides,
for example ethylene oxide and propylene oxide in a
quantitative ratio of about 8:2, in the preparation of
the polyether glycols by alkoxylation of suitable
divalent starter molecules, for example water, ethylene
glycol or propylene glycol.
21 75531
11
.
The compounds employed as component (f) are also
- referred to as chain extenders. Any desired chain
extenders can be used. Examples which may be mentioned
- include polyfunctional primary and secondary amines,
hydrazine, and substituted hydrazines.
Particular preference is given to di- and polyamines
such as ethylenediamine, butylenediamine, tolylenedi-
amine, isophoronediamine, 3,3'-dichlorobenzidine; poly-
alkylenepolyamines, such as trimethylenetetramine,
diethylenetriamine, hydrazine and substituted hydrazines,
-such as mono- and dimethylhydrazine and mono- and
diethylhydrazine. Also suitable are those chain
extenders which carry additional functional groups, for
example alkanolamines such as N-aminoethylethanolamine,
ethanolamine and diethanolamine. It is also useful-to
use carboxyl-containing amines or hydrazides, for example
lysine, glutamic acid, and adipic monohydrazide.
The hydrophilic polyurethanes of the invention which
are especially useful as emulsifiers may be prepared in
any manner, but generally are prepared in two stages.
First of all, a hydrophilic isocyanate-functional
prepolymer is synthesized from components (a) to (e) and
then, after dispersion in water, is reacted with the
chain extenders described under (f).
The preparation of the prepolymer by reacting the
above-mentioned starting components (a) to (e) can be
carried out in bulk or in solvents which are inert with
respect to isocyanate groups, such as ketones, tertiary
alcohols, substituted or unsubstituted aromatic
compounds, ethers or esters, examples being acetone,
methyl ethyl ketone, ethyl acetate, butyl acetate, N-
methylpyrrolidone, toluene and mixtures of such solvents,
preferably keeping to reaction temperatures of from 20 to
200C, in particular from 50 to 150C.
In this procedure, components (b) to (e) can be
reacted with component (a) simultaneously or in steps.
In practice, therefore, one example of a possible
procedure is to introduce components (b) to (e) as
initial charge and to react this charge, within the
12 21 75531
above-mentioned temperature ranges, with the iso-
- cyanate (a) until the NCO content has fallen to a
specific value, which must be calculated.
This prepolymer is then dispersed in water and
reacted with component (f) at temperatures, for example,
from 40 to 100C, resulting in chain extension. After a
reaction time of from 1 to 5 hours, the aqueous
dispersion of the emulsifier is then obtained following,
if appropriate, further addition of ammonia or amines.
10In this context, in principle, the nature and propor-
-tions of the starting components are chosen within the
specified ranges such that, based on all components (a)
to (f), a ratio of the number of isocyanate groups to the
number of reactive hydrogen ;atoms of from 0.6:1 to 1:1 is
15ensured.
The reactions of urethane formation can be catalyzed
in a manner known per se, for example with tin octoate,
dibutyltin dilaurate, or tertiary amines. Similarly, the
polyurethane can be protected against premature and
20unwanted polymerization or oxidation by the addition of
suitable inhibitors and antioxidants generally in respec-
tive amounts of from 0.001 to 0.3%, based on the mass of
the overall mixture.
The hydrophilic polyurethane-polyureas obtained in
25this way, which comprise unsaturated groups are generally
hydroxy functional with hydroxyl numbers (OHN) of from 1
to 80 mg/g, preferably of from 2 to 50 mg/g, and
generally have a number-average molar mass (gel
permeation chromatography, polystyrene as standard) Mn of
30from 2 to 40 kg/mol, preferably from 2 to 20 kg/mol, a
content by mass of olefinic double bonds (calculated as
-C=C-, molar mass = 24 g/mol) of from O to 6%, preferably
from 0.1 to 4%, a content by mass of polyester units of
from 15 to 60~, preferably from 18 to 40~, and a content
35by mass of ethylene oxide units -CH2-CH2-O-, incorporated
via polyethylene glycol, of from 25 to 75%, preferably
from 30 to 60%.
The hydrophilic polyurethane-polyureas represent
valuable emulsifiers for hydrophobic synthetic resins
_ 13 2175531
which are not dispersible in water. These synthetic
- resins generally have a number-average molar mass (Mn;
gel permeation chromatography, polystyrene as standard)
of from 500 to 10,000, preferably from 500 to 5,000,
g/mol. They are particularly suitable as an emulsifier
for alkyd resins and oil-free polyesters, and preferably
for polyesters modified with unsaturated fatty acids.
Synthetic-resin dispersions of this kind are prepared
as desired, for example, by first mixing these synthetic
resins with the above-described polyurethane-polyurea
~dispersions, in the presence if desired of the inert
solvents described above. Heating of the mixture to
temperatures of from about 30 to about 100C may be
necessary.
The mixtures generall~ comprise from 40 to 97,
preferably from 50 to 95, parts by weight of the
hydrophobic synthetic resins in a blend with from 3 to
60, preferably from 5 to 50, parts by weight of the
hydrophilic polyurethane-polyurea dispersions, which act
as emulsifiers. However, it is often important to select
the nature and proportions of the individual components,
within the scope of the comments made, such that the
content by mass in the water-dispersible mixtures of
ethylene oxide units originating from component (e) is
not more than 20%, preferably not more than 15%.
The mixtures of synthetic resins and emulsifier
dispersion are then dispersed in water, which can be done
either by simply stirring water into the initial mixture
of the synthetic resins with the emulsifier emulsion,
using conventional dissolvers or stirrers, or else by
pouring the mixture into water with vigorous stirring.
If desired, it is possible initially to add part of the
water to the mixture described above and then to pour
this mixture, with stirring, into the residual quantity
of water. In this way, stable oil-in-water emulsions can
be obtained.
These oil-in-water dispersions generally are free of
solvent. In special cases, however, small amounts of
solvent may be added, e.g., mass fractions of less than
14 21 75531
.
10%, preferably less than 5%, based on the mass of the
dlspers lon .
The shelf life of the resulting dispersions generally
exceeds one month, and preferably is longer than three
months, particularly preferably longer than six months,
at room temperature.
The aqueous dispersions obtained in this way are
valuable aqueous binders for coating compositions. They
can be used as they are or in combination with the
auxiliaries and additives known from coatings technology,
_such as, for example, fillers, pigments, solvents, or
leveling assistants, for producing coatings on any
desired substrates.
Suitable substrates treated with the coating composi-
tions include paper, cardboard packaging, leather, wood,
plastics, nonwovens, films, textiles, ceramic materials,
mineral materials, glass, metal, coated metal, synthetic
leather and photographic materials, for example paper
provided with a photographic coat.
These coating compositions can be applied in a known
manner, for example, by spraying, knife coating, roller
coating, brush coating, dipping or casting. After the
water and any inert solvents used have been evaporated,
the coatings can be crosslinked, for example, by reaction
with melamine resins or isocyanates at temperatures up to
250C, or by oxidative drying.
The invention is illustrated by the following non-
limiting examples.
In the examples below, all percentages are by mass.
EXAMPLES
Preparation of the polyurethane-polyurea dispersions
Example E1
26.8 g of dimethylolpropionic acid are suspended at
about 80C in 100 g of polyethylene glycol 1000. Then,
after heating to 70C, 51 g of tetramethylxylylene
diisocyanate (TMXDI) and 36.6 g of tolylene diisocyanate
21 75531
(TDI) are added dropwise at a rate such that the
- temperature does not exceed 70C (about 30 min). Once
all of the isocyanate has been added, the mixture is
stirred at the temperature for one hour and then the
reaction temperature is raised to 90C. The temperature
is maintained until the isocyanate content has fallen to
3.8%. Then 30 g of Genapol~ O-100 (an ethoxylated oleyl
alcohol, with 10 mol of ethylene oxide per 1 mol alcohol)
and 121 g of a polyester formed from isophthalic acid,
adipic acid, dimeric fatty acid and hexanediol ( hydroxyl
~number (OHN) 46 mg/g, acid number (AN) 2 mg/g) are added
and the mixture is stirred at 90C until the NCO content
has fallen to 1.15%. Then 400 g of heated deionized
water are added with vigorous stirring over the course of
10 minutes. This is foll~owed directly by the rapid
(about 5 min) dropwise addition of 3.75 g of
trimethylenetetramine dissolved in 37.5 g of water.
After the addition of 4.5 g of triethylamine and after
reaction at 80C for 3 hours, a further 4.4 g of
triethylamine and 1000 g of deionized water are added and
then the mixture is cooled. A pastelike dispersion is
obtained.
Example E2
26.8 g of dimethylolpropionic acid are suspended at
about 80C in 100 g of polyethylene glycol 1000. Then,
after heating to 70C, 51 g of tetramethylxylylene
diisocyanate (TMXDI) and 36.6 g of tolylene diisocyanate
(TDI) are added dropwise at a rate such that the tempera-
ture does not exceed 70C (about 30 min). Once all of
the isocyanate has been added, the mixture is stirred at
the temperature for one hour and then the reaction
temperature is raised to 90C. The temperature is
maintained until the isocyanate content has fallen to
3.8~. Then 30 g of Genapol O-100 and 60 g of a polyester
formed from isophthalic acid, adipic acid, neopentyl
glycol and trimethylolpropane (OHN 107 mg/g, AN 3 mg/g)
are added and the mixture is stirred at 90C until the
NCO content has fallen to 1.4%. Then 400 g of heated
21 75531
16
deionized water are added with vigorous stirring over the
course of 10 minutes. This is followed directly by the
rapid (about 5 min) dropwise addition of 3.75 g of
trimethylenetetramine dissolved in 37.5 g of water.
After the addition of 4.5 g of triethylamine and after
reaction at 80C for 3 hours, a further 4.4 g of
triethylamine and 1000 g of deionized water are added and
then the mixture is cooled. A pastelike dispersion is
obtained.
~Example E3
26.8 g of dimethylolpropionic acid are suspended at
about 80C in 50 g of polyethylene glycol 1000 and 100 g
of polyethylene glycol 2000. Then, after heating to
70C, 51 g of tetramethylxylylene diisocyanate (TMXDI)
and 36.6 g of tolylene diisocyanate (TDI) are added
dropwise at a rate such that the temperature does not
exceed 70C (about 30 min). Once all of the isocyanate
has been added, the mixture is stirred at the temperature
for one hour and then the reaction temperature is raised
to 90C. The temperature is maintained until the
isocyanate content has fallen to 3.2%. Then 117 g of a
polyester formed from isophthalic acid, adipic acid and
neopentyl glycol (OHN 95 mg/g, AN 4 mg/g) are added and
the mixture is stirred at 90C until the NCO content has
fallen to 1.1~. Then 400 g of heated deionized water are
added with vigorous stirring over the course of
10 minutes. This is followed directly by the rapid
(about 5 min) dropwise addition of 3.75 g of
trimethylenetetramine dissolved in 37.5 g of water.
After the addition of 4.5 g of triethylamine and after
reaction at 80C for 3 hours, a further 4.4 g of
triethylamine and 1000 g of deionized water are added and
then the mixture is cooled. A pastelike dispersion is
obtained.
17 21 75531
,
Example E4
400 g of polyethylene glycol 4000 are initially
introduced into the flask. After heating to 70C, 49 g
of tetramethylxylylene diisocyanate (TMXDI) are added
dropwise at a rate such that the temperature does not
exceed 90C (about 30 min). Once all of the isocyanate
has been added stirring is continued at this temperature
until the isocyanate content has fallen to 1.9%. Then
117 g of a polyester formed from isophthalic acid, adipic
acid and neopentyl glycol (OHN 95 mg/g, AN 4 mg/g) are
~added and the mixture is stirred at 90C until the NCO
content has fallen to 0.75%. Then 400 g of heated
deionized water are added with vigorous stirring over the
course of 10 minutes. This is followed directly by the
rapid (about 5 min) dropwise addition of 3.75 g of
trimethylenetetramine dissolved in 37.5 g of water.
After reaction at 80C for 3 hours a further 1000 g of
deionized water are added and then the mixture is cooled.
A pastelike dispersion is obtained.
Example E5
26.8 g of dimethylolpropionic acid are suspended at
about 80C in 100 g of polyethylene glycol 1000. Then,
after heating to 70C, 51 g of tetramethylxylylene diiso-
cyanate (TMXDI) and 36.6 g of tolylene diisocyanate (TDI)
are added dropwise at a rate such that the temperature
does not exceed 70C (about 30 min). Once all of the
isocyanate has been added, the mixture is stirred at the
temperature for one hour and then the reaction tempera-
ture is raised to 90C. The temperature is maintained
until the isocyanate content has fallen to 3.8%. Then
30 g of Genapol 0-100 and 71 g of a polyester formed from
isophthalic acid, adipic acid, soya oil fatty acid,
neopentyl glycol and trimethylolpropane (OHN 90 mg/g,
acid number 5 mg/g) are added and the mixture is stirred
at 90C until the NCO content has fallen to 1.3%. Then
400 g of heated deionized water are added with vigorous
stirring over the course of 10 minutes. This is followed
directly by the rapid (about 5 min) dropwise addition of
21 75531
18
._
3.75 g of trimethylenetetramine dissolved in 37.5 g of
water. After the addition of 4.5 g of triethylamine and
after reaction at 80C for 3 hours, a further 4.4 g of
triethylamine and 1000 g of deionized water are added and
then the mixture is cooled. A pastelike dispersion is
obtained.
Example E6
26.8 g of dimethylolpropionic acid are suspended at
about 80C in 150 g of polyethylene glycol 1500 and 27 g
-~of Ocenol HD 150 (unsaturated fatty alcohol, iodine
number 130). Then, after heating to 70C, 49 g of tetra-
methylxylylene diisocyanate (TMXDI) and 35 g of tolylene
diisocyanate (TDI) are added;dropwise at a rate such that
the temperature does not exceed 70C (about 30 min).
Once all of the isocyanate has been added, the mixture is
stirred at the temperature for one hour and then the
reaction temperature is raised to 85C. The temperature
is maintained until the isocyanate content has fallen to
about 1.5%. Then, with vigorous stirring, 475 g of
-20 heated deionized water to which 3.5 g of diethylenetri-
amine have been added are introduced over the course of
10 minutes. After reaction at 80C for 3 hours, 7 g of
25% ammonia water, diluted with 64 g of deionized water,
are added and the mixture is cooled. A pastelike disper-
sion is obtained.
Dispersions
Example Dl
220 g of emulsifier E1 are added to 200 g of a
commercial alkyd resin with an oil content of 34%
(Alftalat~ AF 342 100%) and the mixture is stirred at
70C for about 60 min until it is homogeneous.
Following the addition of 1 ml of ammonia water
(25%), 70 g of deionized water heated at 70C is added
dropwise very slowly with vigorous stirring (about
2 hours). A milky, pseudoplastic dispersion is obtained.
2 1 7 5531
19
Example D2
205 g of emulsifier E3 are added to 200 g of a
commercial urethane group-containing oil-free polyester
having an OHN of 120 mg/g and an AN of 3 mg/g and the
mixture is stirred at 70C for about 60 min until it is
homogeneous.
Following the addition of 1 ml of ammonia water
(25%), 50 g of deionized water heated at 70C is added
dropwise very slowly with vigorous stirring (about
1 hour). A milky, pseudoplastic dispersion is obtained.
Example D3
140 g of emulsifier E3 are added to 200 g of a
commercial oil-free polyester having an OHN of 115 mg/g
and an AN of 5 mg/g (Alftalat AN 950) and the mixture is
stirred at 70C for about 60 min until it is homogeneous.
Following the addition of 1 ml of ammonia water (25%),
50 g of deionized water heated at 70C is added dropwise
very slowly with vigorous stirring (about 1 hour). A
milky, pseudoplastic dispersion is obtained.
Example D4
230 g of emulsifier E5 are added to 200 g of a
commercial alkyd resin with an oil content of 62% (e.g.,
Alftalat AS 632 100%) and the mixture is stirred at 50C
for about 60 min until it is homogeneous.
Following the addition of 1 ml of ammonia water
(25%), 70 g of deionized water heated at 70C is added
dropwise very slowly with vigorous stirring (about
2 hours). A milky, pseudoplastic dispersion is obtained.
All of the other emulsifiers listed are processed to
give dispersions in accordance with the examples
described above.
Although only a few exemplary embodiments of this
invention have been described in detail above, those
skilled in the art will readily appreciate that many
modifications are possible in the exemplary embodiments
without materially departing from the novel teachings and
~ 20 21 75531
advantages of this invention. Accordingly, all such
modifications are intended to be included within the
scope of this invention.
