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Description  |
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BACKGROUND OF THE INVENTION
It is known to use compounds which contain from two to six OH groups and
have a molecular weight of from 62 to about 10,000 for preparing
polyurethanes. The following are examples of such polyhydroxyl compounds:
simple polyhydric alcohols, e.g. ethylene glycol, diethylene glycol,
hexane diol, glycerol, trimethylol propane. Further examples include
higher molecular weight polyethers, polythioethers, polyesters and
polyacetals. These higher molecular weight polyhydroxyl compounds are
prepared from low molecular weight units in known manner. These hydroxyl
compounds generally have only a low polarity and carry no other functional
groups.
For preparing foams from polyisocyanates and polyhydroxyl compounds, it is
generally necessary to use surface active compounds, especially
organopolysiloxanes. These substances have an emulsifying action on the
reactants and stabilize the foam structure which initially is still
liquid. Emulsifiers are occasionally also used for the production of
non-cellular polyurethanes if the reactants are insufficiently compatible
or if fillers are used. In many cases, the emulsifier or stabilizer must
be added as a separate component to the reaction mixture, which may entail
problems of dosing because of the small quantities in which these
components are generally used.
It would be advantageous if, for example, in the case of incompatibility of
the reactants, it would be possible to dispense with the use of particular
surface active compounds because the polyols used already have the desired
surface active properties. There is therefore a need for polyols having
surface active properties. Moreover, there is a demand for polyols which
are hydrophilic and have a relatively high polarity so that they will have
better compatibility with water and so that the foams produced from the
polyols will have a certain water absorption capacity, as well as improved
resistance to solvents. There is also a demand for polyhydroxyl compounds
which yield polyurethanes having improved fire characteristics. Lastly, it
would be desirable to have OH prepolymers available which do not give rise
to toxic aromatic diamines when they undergo hydrolytic degradation.
The present invention provides a solution to these problems.
DESCRIPTION OF THE INVENTION
The instant invention is directed to a process wherein polyhydroxyl
compounds are reacted with sub-equivalent molar quantities of aromatic
isocyanatosulfonic acids, optionally in admixture with conventional
polyisocyanates. The reaction products will be a mixture of hydroxyl
containing compounds. These compounds have increased polarity and surface
active properties and impart to the products produced from them improved
fire characteristics, as well as the ability to be welded by high
frequency welding. The instant invention is directed to the process, the
mixture of compounds produced, specific compounds within the mixture, and
the products by this specific process.
The present invention relates to compounds having an average molecular
weight of from 300 to 12,000 which have at least one hydroxyl group and at
least one urethane-arylsulfonic acid group.
Preferred compounds are those which have an average molecular weight of
from 400 to 12,000 and are characterized by at least one OH-functional
long chain containing from 15 to 400, preferably from 30 to 300, chain
members. The chain members are, for example, --CH(CH.sub.3)--or--CH.sub.2
--groups, ether oxygen atoms, CO groups, sulfur atoms and/or nitrogen
atoms.
The compounds according to the present invention preferably contain at
least one structural unit corresponding to the following general formula:
##STR1##
wherein R.sub.1 represents the residue from a polyol containing from 2 to
6 OH groups e.g a polyester, polyether, polythioether or polyester amide;
and
Ar represents a polyvalent group of an aromatic isocyanate.
Compounds corresponding to the following general formula are preferred
according to the present invention:
##STR2##
The present invention also relates to a process for the preparation of
compounds having an average molecular weight of from 300 to 12,000 which
have at least one hydroxyl group and at least one urethano-aryl-sulfonic
acid group, characterized in that compounds having a molecular weight of
from 62 to 10,000 which have at least two hydroxyl groups are reacted with
aromatic isocyanato- sulfonic acids at from 0.degree. to 190.degree. C.,
using an equivalent ratio of the total quantity of isocyanate groups
(including any isocyanate groups present in dimerized form) to sulfonic
acid groups of from 0.5:1 to 50:1 and an equivalent ratio of hydroxyl
groups to isocyanate groups of from 1.5:1 to 30:1.
Furthermore, the present invention relates to the use of the compounds
according to the present invention as reactants for polyisocyanates for
the production of polyaddition products or polycondensation products.
Compared with the known polyhydroxyl compounds, the new compounds according
to the present invention have numerous advantageous properties, as
indicated below;
1. They are a highly polar or surface active character and an exceptionally
low vapor pressure and they have excellent compatibility with numerous
polar and apolar media and reactants.
2. Both the surface active properties and the hydrophilic character may be
controlled within wide limits as desired according to the nature and
quantity of the isocyanatoarylsulfonic acid used in the process and the
nature and quantity of the bases used for neutralizing the sulfonic acid
groups.
3. Hydrolytic degradation of the products results in toxicologically
harmless amino sulfonic acids.
4. The use of the compounds according to the present invention, for example
for the production of polyurethanes, results in products which have
improved fire characteristics. When carrying out the process according to
the present invention, part of the OH groups of the polyhydroxyl compounds
used as starting material undergo addition with the isocyanate groups and
any uretdione groups optionally present in the isocyanatoaryl sulfonic
acid to form higher molecular weight new polyhydroxyl compounds which, at
least in part, contain urethane groups and one or more free sulfonic acid
groups. The sulfonic acid groups may subsequently be partly or completely
neutralized with conventional inorganic or organic bases.
Any of the compounds conventionally used in polyurethane chemistry which
have a molecular weight of from 62 to 10,000 and contain at least two
hydroxyl groups may be used as starting material for the process according
to the present invention. The following are examples: low molecular weight
glycols, polyesters, polyethers, polyester amides, OH-functional
oligomers, polymers, for example polyethers based on butadiene or grafted
with vinyl monomers or also polyethers which contain other polymers, such
as polyureas, urea resins, polyhydrazodicarbonamides or vinyl polymers
dispersed in them. Examples of suitable hydroxy-functional compounds are
given below.
Suitable polyesters containing hydroxyl groups include, e.g. reaction
products of polyhydric, preferably dihydric, alcohols, optionally with the
addition of trihydric alcohols, and polybasic, preferably dibasic,
carboxylic acids. Instead of free polycarboxylic acids, the corresponding
polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters
of lower alcohols or mixtures thereof may be used for preparing the
polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic,
aromatic and/or heterocyclic. They may be substituted, e.g. by halogen
atoms, and/or they may be unsaturated. The following are suitable
examples: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic
acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid
anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid
anhydride, tetrachlorophthalic acid anhydride, endomethylene
tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid,
maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids,
such as oleic acid, optionally mixed with monomeric fatty acids, dimethyl
terephthalate and terephthalic acid-bis-glycol esters. The following are
examples of suitable polyhydric alcohols: ethylene glycol, propylene
glycol-(1,2) and -(1,3), butylene glycol-(1,4) and -(2,3),
hexanediol-(1,6), octanediol-(1,8), neopentylglycol, cyclohexanedimethanol
(1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3 propanediol, glycerol,
trimethylolpropane, hexanetriol-(1,2,6), butanetriol-(1,2,4),
trimethylolethane, pentaerythritol, quinitol, mannitol, sorbitol,
methylglycoside, diethylene glycol, triethylene glycol, tetraethylene
glycol, polyethylene glycols, dipropylene glycol, polypropylene glycols,
dibutylene glycol and polybutylene glycols. The polyesters may also
contain a proportion of carboxyl end groups. Polyesters of lactones, such
as .epsilon.-caprolactone, or hydroxycarboxylic acids, such as
.omega.-hydroxycaproic acid, may also be used.
The polyethers of the invention, which preferably have two hydroxyl groups,
are also known and are prepared, for example, by polymerization of
epoxides, such as ethylene oxide, propylene oxide, butylene oxide,
tetrahydrofuran, styrene oxide or epichlorohydrin or
1.1.1-trichloroacetene-3,4-oxide. They may be polymerized on their own,
e.g. in the presence of BF.sub.3, or by addition of these epoxides, if
desired, as mixtures or successively, to starting components having
reactive hydrogen atoms. Examples of starting components include alcohols
such as ethylene glycol, propylene glycol-(1,3) or -(1,2), or
4,4'-dihydroxydiphenylpropane, amines such as aniline or water.
Polyethers modified by vinyl polymers, for example the compounds obtained
by the polymerization of styrene or acrylonitrile in the presence of
polyethers (U.S. Pat. Nos. 3,383,351; 3,304,273; 3,523,093; and 3,110,695
and German Pat. No. 1,152,536) are also suitable. The higher functional
polyethers which may also be included in limited amounts are obtained
analogously by the known method of alkoxylation of higher functional
starter molecules, such as ammonia, ethanolamine, ethylene diamine or
sucrose.
Preferred polythioethers are the condensation products obtained by reacting
thiodiglycol on its own and/or with other glycols, dicarboxylic acid,
formaldehyde, aminocarboxylic acids or amino alcohols. The products
obtained are polythio mixed ethers, polythio ether esters or polythio
ether ester amides, depending on the co-components.
Suitable polyacetals include, for example, the compounds which may be
prepared by the reaction of glycols, such as diethylene glycol,
triethylene glycol, 4,4'-dioxethoxydiphenyl dimethylmethane and
hexanediol, with formaldehyde. Suitable polyacetals for the purposes of
the instant invention may also be prepared by the polymerization of cyclic
acetals.
The polycarbonates containing hydroxyl groups used may be of the type which
may be prepared by the reaction of diols, such as propanediol-(1,3),
butanediol-(1,4) and/or hexanediol-(1,6), diethylene glycol, triethylene
glycol or tetraethylene glycol, with diaryl carbonates, e.g. diphenyl
carbonate, or with phosgene.
Suitable polyester amides and polyamides include, for example, the
predominantly linear condensates prepared from poly-basic saturated and
unsaturated carboxylic acids or the anhydrides thereof and polyfunctional
saturated and unsaturated amino alcohols, diamines, polyamines and
mixtures thereof. Polyhydroxyl compounds which already contain urethane or
urea groups may also be used.
There may also be used polyhydroxyl compounds which contain high molecular
weight polyadducts or polycondensates in a finely dispersed or dissolved
form. Such modified polyhydroxyl compounds are obtained when polyaddition
reactions (e.g. reactions between polyisocyanates and amino-functional
compounds) or polycondensation reactions (e.g. between formaldeyhyde and
phenols and/or amines) are carried out in situ in the above-mentioned
hydroxyl group-containing compounds. Processes of this type have been
described in German Auslegeschriften Nos. 1,168,075 and No. 1,260,142 and
in German Offenlegungsschriften Nos. 2,324,134; 2,423,984; 2,512,385;
2,513,815; 2,550,796; 2,550,797; 2,550,833; and No. 2,550,662. Such
modified polyhydroxyl compounds may also be obtained according to U.S.
Pat. No. 3,869,413 or German Offenlegungsschrift No. 2,550,860 by mixing a
previously prepared aqueous polymer dispersion with a polyhydroxyl
compound and then removing the water from the mixture.
The following are examples of low molecular weight glycols which may be
reacted with isocyanatosulfonic acids, either on their own or as mixtures
with the above-mentioned higher molecular weight polyhydroxyl compounds:
ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene
glycol, propylene glycol, oligopropylene glycols, propylene glycol-(1,3),
butanediol hexanediol, 2-ethyl-hexanediol, octanediol, glycerol,
trimethylol-propane and dodecanediol. Amino-alcohols, such as
ethanolamine, propanolamine or diethanolamine, may also be used, provided
all the amino groups present are reacted with isocyanate groups. Mono-,
di- or poly-amines or water may also be used in minor quantities. The
products obtained from the reaction should at the most contain only minor
quantities of carboxyl groups or mercapto groups in addition to the OH
groups.
The isocyanato-ary-sulfonic acids used in the process according to the
present invention may be sulfonation product of any known aromatic
polyisocyanates. The following are examples of such aromatic
polyisocyanates which may be used in the form of the sulfonation products
thereof in the process: 4,4'-stilbene-diisocyanate;
4,4'-dibenzyl-diisocyanate; 3,3'-and
2,2'-dimethyl-4,4'-diisocyanatodiphenylmethane;
2,3,2',5'-tetramethyl-4,4'-diisocyanatodiphenylmethane;
3,3'-dimethoxy-4,4'-diisocyanatodiphenylmethane;
3,3'-dichloro-4,4'-diisocyanato-diphenylmethane;
4,4'-diisocyanatodiphenyl-cyclohexylmethane;
4,4'-diisocyanato-benzophenone; 4,4'-diisocyanatodiphenyl-sulphone;
4,4'-diisocyanatodiphenyl ether;
4,4'-diisocyanato-3,3'-dibromodiphenylmethane;
4,4-diisocyanato-3,3'-diethyldiphenylmethane;
4,4'-diisocyanatodiphenylethylene-(1,2),
4,4'-diisocyanatodiphenylsulphide; 1,3- and 1,4-phenylene-diisocyanate;
2,4- and 2,6-tolylene diisocyanate and mixtures of these isomers;
diphenylmethane-2,4'- and/or -4,4'-diisocyanate;
naphthylene-1,5-diisocyanate; triphenylmethane-4,4',4"-triisocyanate;
polyphenyl-polymetylene polyisocyanates of the type obtained by aniline
formaldehyde condensation followed by phosgenation, which have been
described, for example, in British Pat. No. 874,430 and 848,671;
polyisocyanates having carbodiimide groups as described in German Pat. No.
1,092,007; diisocyanates of the type described in U.S. Pat. No. 3,492,330,
polyisocyanates having allophanate groups are described, e.g. in British
Pat. No. 994,890, Belgian Pat. No. 761,626 and published Dutch patent
application No. 7,102,524; polyisocyanates having isocyanurate groups as
described, e.g. in German Pat. Nos. 1,022,789; 1,222,067 and No. 1,027,394
and in German Offenlegungsschriften No. 1,929,034 and No. 2,004,048;
polyisocyanates having acylated urea groups, according to German Pat. No.
1,230,778; polyisocyanates having biuret groups, e.g. as described in
German Pat. No. 1,101,394, British Pat. No. 889,050 and French Pat. No.
7,017,514. The distillation residues obtained from the commercial
production of isocyanates and still containing isocyanates groups may also
be used, optionally as solutions in one or more of the above-mentioned
polyisocyanates. Mixtures of the abovementioned polyisocyanates may also
be used.
Phosgenation products of condensates of aniline with aldehydes or ketones,
such as acetaldehyde, propionaldehyde, butyraldehyde, acetone or
methylethyl ketone, are also suitable. The phosgenation products of
condensates of aniline which are alkyl-substituted on the nucleus, such as
toluidines, with aldehydes or ketones, such as formaldehyde, acetaldehyde,
butyraldehyde, acetone or methylethyl ketone, are also suitable.
Reaction products of the above-mentioned aromatic polyisocyanate mixtures
with from 0.2 to 50 mol% of polyols are also suitable, provided the
viscosity of the resulting reaction products does not exceed 50,000 cP at
25.degree. C. and the isocyanate content of the reaction products is at
least 6%, by weight. Suitable polyols for the modification of the starting
materials include, in particular, polyether- and polyester- polyols with a
molecular weight of from 200 to 6,000, preferably from 300 to 4,000, which
are known in polyurethane chemistry, and low molecular weight polyols with
a molecular weight of from 62 to 200 are also suitable. Examples of such
low molecular weight polyols include ethylene glycol, propylene glycol,
glycerol, trimethylol propane and 1,4,6-hexanetriol.
Particularly preferred isocyanatoaryl-sulfonic acids are the sulfonation
products of tolylene-2,4-diisocyanate and mixtures of tolylene-2,4- and
-2,6-diisocyanate. Likewise preferred are the sulfonation products of di-
or poly-isocyanates obtained by the phosgenation of aniline/formaldehyde
condensates and the products of partial sulfonation of aromatic
polyisocyanates. The products of partial sulfonation of chemically uniform
diisocyanates or of binary isomeric mixtures are generally obtained as
suspensions whereas the partial sulfonation of multi-component mixtures
generally results in homogeneous solutions. For the process of the present
invention, it is immaterial in principle whether solutions or suspensions
are used. Partially sulfonated polyisocyanate mixtures of the type which
are obtained by the phosgenation of aniline/formaldehyde condensates and
which have been described in German Offenlegungsschriften Nos. 2,227,111;
2,359,614 and No. 2,359,615 are particularly suitable. Suspensions of
diisocyanatotoluene-sulfonic acid dimers and
diisocyanatodiphenylmethane-sulfonic acid dimers in diisocyanatotoluene or
diisocyanato-diphenylmethane are also particularly preferred.
The preparation of isocyanatoaryl-sulfonic acids used in the process, or
mixtures thereof with unsulfonated aromatic polyisocyanates, is carried
out by processes known in the art or by analogous processes such as those
based on the processes disclosed in the above-mentioned publications or in
U.S. Pat. No. 3,826,769. The processes according to German
Offenlegungsschriften No. 25 24, 476 and No. 26 15 876 are also suitable
for the preparation of isocyanatoaryl sulfonic acids which may be used in
the process according to the present invention.
Solutions or suspensions of the exemplified isocyanatoaryl sulfonic acids
in aliphatic polyisocyanates, such as tetramethylene diisocyanate or
hexamethylene diisocyanate, and/or in cycloaliphatic or mixed
aliphatic-cycloaliphatic polyisocyanates, such as
4,4'-diisocyanatodicyclohexylmethane, 2,4- or
2,6-diisocyanato-hexahydrotoluene or
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, may also be
used in the process. If it is desired to lower the isocyanate
functionality of the products obtained by the process of the invention,
there may also be used solutions or suspensions of the
isocyanatoaryl-sulfonic acids in aromatic, aliphatic or cycloaliphatic
monoisocyanates. Examples of suitable monoisocyanates include
phenylisocyanate, tosylisocyanate, n-hexylisocyanate,
6-chlorohexylisocyanate, cyclohexylisocyanate and
methoxymethylisocyanates. It would also be possible to use sulfonated
aromatic monoisocyanates, such as phenylisocyanate, as the
isocyanatoaryl-sulfonic acid in combination with unsulfonated
polyisocyanates of the type exemplified. The nature and proportions of the
isocyanates to be used in the process of the invention and the degree of
sulfonation are frequently chosen so that the equivalent ratio of
isocyanate groups which may be partially present in dimerized form, to
sulfonic acid groups is greater than 1:1, i.e. in particular from 1.05:1
to 50:1, preferably from 2:1 to 30:1. A ratio of from 2:1 to 12:1 is
particularly preferred.
Another group of preferred isocyanato sulfonic acids consists of those
aromatic mono-, di- or poly-isocyanates which contain more than one
sulfonic acid group and in particular two or three sulfonic acid groups.
Isocyanatopolysulfonic acids of this type have been described in German
Offenlegungsschrift No. 2,615,876. If monocyanato-disulfonic acids are
used as part or all of the sulfonic acid component, the equivalent ratio
of NCO groups to SO.sub.3 H groups may also be from 1:1 to 0.5:1.
For the preparation of hydroxyl compounds which have sulfonic acid or
sulfonate groups in end positions, it is preferred to use
monoisocyanato-sulfonic acids, e.g. the sulfonation products of
phenylisocyanate, m-tolylisocyanate, p-tolylisocyanate,
p-chlorophenylisocyanate, p-nitrophenylisocyanate,
p-methoxyphenylisocyanate, p-chloromethyl-phenylisocyanate,
m-chlorophenylisocyanate and m-chloromethylphenylisocyanate.
The ratio of polyhydroxyl compounds to isocyanatosulfonic acid is in most
cases chosen so that OH-functional products having a molecular weight of
below 12,000, preferably below 6,000, are produced. This means that a
molar excess of hydroxy-functional components are used, amounting to at
least 1.5 OH groups per NCO group. By "NCO groups" are meant not only free
NCO groups but also dimerized NCO groups in the form of uretdione groups.
The hydroxy-functional compounds used as starting materials are most
preferably modified only partly with sulfonic acid groups, in which case
up to 30 OH groups may be used per NCO group. An equivalent ratio of OH
groups to NCO groups of from 2:1 to 20:1 is preferred.
The above-mentioned proportions apply mainly to reactions which are carried
out using di- or poly-isocyanates and which lead directly to polyhydroxyl
compounds which are modified with sulfonic acid groups.
However, monoisocyanates containing from 1 to 3 sulfonic acid groups may
also be used for the present invention. These monoisocyanates are reacted
in sub-equivalent molar quantities with the hydroxyl compounds used as
starting materials.
The equivalent ratio of OH groups to NCO groups is preferably from 2 to 6.
The method employed for reacting the hydroxyl compounds used as starting
materials with isocyanates which contain sulfonic acid groups is known in
principle. Generally, the hydroxyl compounds are first introduced into the
reaction vessel and the isocyanate component is added under conditions of
mixing. If the isocyanate is liquid, as, for example, in the case of
partially sulfonated MDI types, mixing of the components and the
subsequent reaction may easily be carried out at room temperature or
slightly elevated temperatures. The choice of temperature in this case
depends entirely on the viscosity of the reaction mixture and the desired
reaction time. If solid isocyanatoaryl mono- or poly-sulfonic acids are
used, a suspension is first formed when the reactants are mixed, and it is
advisable to carry out the reaction at a temperature at which the solid
isocyanate rapidly goes into solution.
Temperatures of from 40.degree. to 180.degree. C., particularly from
60.degree. to 120.degree. C., are suitable for this purpose. Temperatures
above 120.degree. C., up to about 200.degree. C., are preferred in
particular when relatively low molecular weight polyhydroxyl compounds are
used exclusively, in order to prevent solidification of the reaction
mixture during the reaction. Solid isocyanatosulfonic acids are preferably
used in the form of suspensions, pastes or moist powders, using inert
solvents as described in German Offenlegungsschrift No. 2,640,103.
Solid isocyanato-sulfonic acids may also be used in the form of solutions
in organic solvents, preferably using liquid esters of an inorganic or
organic acid of phosphorus as solvent (German Offenlegungsschrift No.
2,650,172).
Any inert solvents, such as hydrocarbons, halogenated hydrocarbons, ethers,
esters or ketones may be added to the reaction mixture. However, it is
preferred to carry out the reaction in the absence of solvents or with
only the small quantities of solvent required for dissolving solid
isocyanatosulfonic acids or converting them into pastes.
According to a preferred embodiment of the process, asymmetric hydroxyl
compounds are prepared by making use of the differing reactivities of the
isocyanate groups. For example, a diisocyanatoaryl-sulfonic acid may first
be reacted with a monofunctional alcohol, a fatty acid, an amino alcohol
or a primary or secondary amine, e.g. up to from 20 to 70% conversion.
Then the remaining isocyanate groups may be reacted with a di- or
polyhydroxyl compound. The surface active properties may be widely varied
according to the nature and quantity of the monofunctional component, as
well as of the polyfunctional component.
Monofunctional compounds which may be used in addition to the
above-mentioned polyhydroxyl compounds include, for example, methanol,
ethanol, isopropanol, n-butanol, glycolmonomethyl ether, glycolmonoethyl
ether, diglycolmonomethyl ether, n-octanol, n-dodecanol, oleyl alcohol,
stearyl alcohol, hydroxyfunctional fatty acid esters of glycerol,
trimethylolpropane, trimethylolethane, stearic acid, coconut fatty acid,
linseed oil fatty acid, soya-bean oil fatty acid, aminoethanol,
aminopropanol (amino alcohols of this type may be regarded as
approximately mono-functional for the purpose of the procedure described
above on account of the wide difference in reactivity between the amino
function and the hydroxyl function), butylamine, secondary butylamine and
coconut fatty amine.
The stepwise preparation of such asymmetric hydroxyl compounds is most
preferably carried out in a solvent, e.g. in acetone or an organic
phosphoric acid ester. Short-chain hydrophilic monofunctional compounds
are preferably combined with predominantly hydrophobic polyhydroxyl
compounds, whereas long-chain hydrophobic monofunctional compounds are
preferably combined with hydrophilic polyhydroxyl compounds.
The hydroxyl compounds containing sulfonic acid groups may be partly or
completely neutralized using organic or inorganic bases. Suitable
neutralizing agents are, e.g. organic bases, such as monofunctional
primary, secondary and tertiary amines. Examples are methylamine,
diethylamine, triethylamine, trimethylamine, dimethylamine, ethylamine,
tributylamine, pyridine, aniline, toluidine, alkoxylated amines, such as
ethanolamine, diethanolamine, triethanolamine, methyldiethanolamine,
dimethylaminoethanol or oleyldiethanolamine. Other neutralizing agents are
polyfunctional polyamines in which the individual amino groups may differ
in the basicity thereof, e.g. the polyamines obtained by the hydrogenation
of addition products of acrylonitrile with primary and secondary amines,
per alkylated or partially alkylated polyamines, such as
N,N-dimethylethylene diamine, or compounds, such as .alpha.-aminopyridine
or N,N-dimethylhydrazine. Inorganic bases, compounds which are basic in
reaction or split off bases, such as ammonia or monovalent metal
hydroxides, carbonates or oxides, such as sodium hydroxide or potassium
hydroxide may also be used.
Suitable neutralizing agents also include guanidines, guanidine carbonate,
urea, methyl urea, dimethyl urea, caprolactam, dimethylformamide,
dimethylacetamide, pyrrolidone and solid inorganic bases. Examples of
solid inorganic bases are calcium oxide, calcium hydroxide, calcium
carbonate, magnesium oxide, magnesium carbonate, dolomite, lithium
hydroxide, lithium carbonate, zinc oxide, zinc carbonate and basic
inorganic fillers.
Weak basic neutralizing agents, such as urea or caprolactam, and basic
fillers may be used in excess over the sulfonic acid groups present.
The products of the present invention are valuable starting materials for
the production of polyurethane plastics by the isocyanate polyaddition
process. They are suitable, for example, for the production of
non-cellular or cellular elastomers, flexible foams and rigid foams,
especially where high demands are made on the cross-linking density, fire
characteristics or degradability. Thus, for example, the polyhydroxyl
compounds of the invention are suitable for the manufacture of upholstery
padding, mattresses, elastic underlays, motor car seats, damping
materials, shock absorbers, constructional materials, sound damping
insulations and moisture absorbing materials, e.g. for the surgical field,
and for the manufacture of substrates for cultivating plants, and for
protection against heat and cold. The polyhydroxyl compounds are
particularly suitable for the production of inorganic-organic synthetic
materials, for example by processes analogous to those described in German
Patent 2,310,559 and German Offenlegungsschriften No. 2,227,147 and No.
2,359,608, and for the production of surface coatings, impregnations and
bonds.
The products are versatile in their use. They can be used as surface active
compounds, e.g. as emulsifiers or foam stabilizers, and as dye auxiliaries
or flotation substances and for the preparation of polyurethane
dispersions.
One particular advantage of the hydroxyl compounds of the invention is
their increased polarity. This distinguishes the products, for example
from pure polypropylene glycol ethers, in rendering them compatible with
low molecular weight glycols, such as ethylene glycol, diethylene glycol,
1,4-butanediol or glycerol. Mixtures are homogeneous and therefore stable
in storage.
The reaction of the polyhydroxyl compounds of the invention with
polyisocyanates which contain sulfonic acid ester groups is particularly
suitable for the preparation of polyaddition products which have good fire
characteristics.
The compounds of the invention are particularly to be recommended when
polyisocyanate components and polyhydroxyl components, due to the
incompatibility thereof, first form emulsions which must subsequently be
rendered homogeneous after a certain period of induction. Even very small
quantities of the products promote the formation of exceptionally finely
divided emulsions which react much more rapidly. Moreover, the new
products influence the pore structure of foams produced from them and in
many cases effect a desirable increase in the compression resistance.
Lastly, the products are also suitable for rendering surface-modified
inorganic fillers hydrophobic.
EXAMPLE 1
2,000 g of a polypropylene ether having an OH number of 42 and started on
84% of trimethylol propane and 16% of 1,2-propylene glycol are intimately
mixed at room temperature with 62 g of the toluene-moist uretdione of
diisocyanatotoluene sulfonic acid (prepared from tolylene diisocyanate,
isomeric mixture 2,4:2,6=80:20), corresponding to 40 g of dry substance.
The suspension is heated to 100.degree. C. within 45 minutes and
maintained at from 100.degree. to 125.degree. C. for 3 hours. Toluene is
evaporated off at 14 Torr and 100.degree. C. and the solution is filtered.
Sulfur content: 0.24%;
Viscosity: 2,200 cP;
pH of a solution of 1 g of product in 90 g of methanol and 10 g of water:
2.7.
EXAMPLE 2
38 g of a 15% methanolic potassium hydroxide solution are added to 1021 g
of the product from Example 1 and the methanol is evaporated off under
vacuum at 35.degree. C.
pH: 8;
Viscosity: 1700 cP.
EXAMPLE 3
The procedure is the same as in Example 1, but using 154 g (100 g of dry
substance) of uretdione.
Viscosity: 32,000 cP
EXAMPLE 4
83 g of a 15% methanolic potassium hydroxide solution are added to 1064 g
of the product from Example 3 and the methanol is evaporated off under
vacuum at 35.degree. C.
pH: 8;
Viscosity: 90,000 cP.
EXAMPLE 5
4,000 g of a polypropylene polyether which has been started on trimethylol
propane and contains 13% of ethylene glycol ether groups in end positions
and has an OH number of 35 are intimately mixed at room temperature with
123 g (80 g of dry substance) of the uretdione described in Example 1. The
reaction mixture is stirred at from 25.degree. to 27.degree. C. under
nitrogen for 1 hour, then heated to 50.degree. C. and maintained at this
temperature for 4 hours, during which time the toluene is evaporated off
by application of a water jet vacuum. Most of the uretdione goes into
solution. Stirring is then continued for 8 hours at from 60.degree. to
65.degree. C. and the solution is filtered. Ca. 0.3 g of residue are left
on the filter.
OH number: 36.4;
Acid number: 4.7.
EXAMPLE 6
77 g of a 15% methanolic potassium hydroxide solution are added to 2060 g
of the product from Example 5 and the methanol is evaporated off under
vacuum at 35.degree. C.
pH: 8;
OH number: 32.6
Acid number: 0.2.
EXAMPLE 7
The procedure is the same as in Example 5, but starting from a
corresponding polyether of OH number 28. A yellowish-brown, viscous
modified polyether is obtained.
OH number: 28.1;
Acid number: 4.7.
EXAMPLE 8
69 g of a 15% methanolic potassium hydroxide solution are added to 2060 g
of the product from Example 7 and the methanol is evaporated off under
vacuum at 35.degree. C.
pH: 7.5;
OH number: 21.4;
Acid number: 0.2.
EXAMPLE 9
200 g of the uretdione of diisocyanatotoluene sulfonic acid (see Example 1)
are triturated with 373 g of toluene and mixed, with stirring at
50.degree. C. with 10 kg of a polypropylene ether which has been started
on trimethylol propane and contains 17% of ethylene glycol ether groups as
end groups and has an OH number of 35. The temperature is then raised to
60.degree. C. and the toluene is evaporated off by application of a water
jet vacuum. The uretdione dissolves virtually quantitatively within 9
hours. The modified polyether is finally filtered over a fine metal sieve
at 60.degree. C.
OH number: 34.5;
Acid number: 4.3;
Sulfur content: 0.2%.
If the uretdione is triturated with 200 g of trischloroethyl phosphate
instead of with toluene before it is added to the polyether, the product
goes into solution after a short time at 60.degree. C.
EXAMPLE 10
380 g of toluene-moist uretdione of diisocyanatotoluene sulfonic acid (see
Example 1) corresponding to 300 g of dry substance are thoroughly
triturated with 550 g of toluene and added with stirring at 50.degree. C.
to 15 kg of a polypropylene ether which has been started on trimethylol
propane, contains 13% of ethylene glycol ether groups in end positions and
has an OH number of 28. The reaction mixture is then heated to 65.degree.
C. and stirred for 5 hours, during which time most of the uretdione goes
into solution. During a further 3 hours stirring at 65.degree. C., the
toluene is distilled off in a water jet vacuum and the product obtained is
filtered over a metal sieve at 50.degree. C. to remove ca. 4 g of
undissolved constituents.
OH number: 22.2;
Acid number: 4.7;
Sulfur content: 0.22%
Toluene content: 0.6%.
EXAMPLE 11
156 g of a 15% methanolic potassium hydroxide solution are added dropwise
with stirring at room temperature over a period of 1 hour to 5000 g of the
product obtained according to Example 10. The methanol is then distilled
off in a water jet vacuum at temperatures of up to 55.degree. C. The
resulting sulfonate group-containing polyether has a viscosity of 3,400
cP.
OH number: 21.2;
Acid number: 0.9.
EXAMPLE 12
42 g of triethylamine are added dropwise at room temperature within 2 hours
to 5000 g of the polyether obtained according to Example 10. Stirring is
then continued for a further 5 hours at room temperature.
Viscosity: 3,400 cP;
OH number: 23.9.
EXAMPLE 13
142 g of bis-(2-hydroxyethyl)-oleylamine are added dropwise to 4,800 g of
the polyether obtained according to Example 10. The reaction mixture is
then stirred for 4 hours at room temperature.
Vicosity: 3,800 cP;
OH number: 34.4.
The following materials were used for the foaming experiments:
Polyol A: polyoxyalkylene ether triol having an equivalent weight of 2000,
containing polyoxyethylene blocks in end positions and containing over 80%
of primary hydroxyl groups.
Polyol B: the sulfonic acid group-containing polyetherpolyol from Example
8, neutralized with KOH.
Polyol C: the sulfonic acid group-containing polyetherpolyol from Example
11, neutralized with KOH.
Polyol D: corresponds to polyol C, but neutralized with triethylamine
(Example 12).
Polyol E: corresponds to polyol C, but neutralized with
N,N-dihydroxy-ethyloleylamine (Example 13).
Dabco: 1,4-diazabicyclo octane (triethylene diamine).
TCAP: tris-(2-chloroethyl)-phosphate.
EXAMPLE 14
The following components were weighed into a cardboard cup and vigorously
stirred using a high-speed stirrer for 60 seconds:
100 parts, by weight, of polyol A
100 parts, by weight, of polyol B
6.4 parts, by weight, of water
0.2 parts, by weight, of "Dabco"
7.2 parts, by weight, of diisopropanolamine
2.0 parts, by weight, of triethanolamine
2.0 parts, by weight, of diethanolamine
4.0 parts, by weight, of TCAP
1.0 part, by weight, of a short-chain polyphenylsiloxane stabilizer
according to German Offenlegungsschrift No. 2,232,525.
55.4 parts, by weight, (corresponding to an NCO/OH index=100) of a modified
tolylene diisocyanate (Desmodur MT 58, allophanate-TDI) were added to the
homogeneous mixture and rapidly mixed in. The mixture began to foam after
5 seconds. It was immediately poured into a rectangular mold formed by
folding paper and it foamed within 60 seconds and had set 10 seconds after
foaming ended. A highly elastic foam having a fine cell structure, a unit
weight of 36 g/l and high compression resistance and tensile strength was
obtained. A strip of the foam 2 cm in thickness and 10 cm in width was
exposed at one end to the blue flame of a Bunsen burner. The foam burned
with a small amount of smoke and melted slightly, but extinguished itself
shortly after removal of the Bunsen flame.
EXAMPLES 15 TO 17
Foams were produced from the following formulations (quantities in parts,
by weight) by the methods described in Example 14:
______________________________________
15 16 17
Polyol C 100 -- --
Polyol D -- 100 --
Polyol E -- -- 100
Water 3.2 3.2 3.2
Dabco 0.2 0.2 0.2
Diisopropanolamine 3.6 3.6 3.6
Triethanolamine 1.0 1.0 1.0
Diethanolamine 1.0 1.0 1.0
TCAP 2.0 2.0 2.0
Polyphenylsiloxane as in
Example 1 3.0 3.5 3.0
Bis-2-N,N-dimethyl-
aminoethyl ether 0.2 0.2 0.25
Modified tolylene diisocyanate
55.2 55.2 55.2
(according to example 14)
NCO/OH index 100 100 100
______________________________________
The following reaction times were found during foaming:
______________________________________
a b c
______________________________________
Stirring time (cream time)
10" 6" 6"
Rise time 90" 80" 90"
Gel time 25" 20" 20"
______________________________________
The foams obtained correspond generally to the mechanical properties and
fire characteristics to the foam from Example 14.
COMPARISON EXAMPLE
For comparison, a foam was produced from the same formulation, but using
polyol A alone.
______________________________________
Polyol A 100 parts, by weight
Water 3.2 parts, by weight
Dabco 0.1 part, by weight
Diisopropanolamine 3.6 parts, by weight
Triethanolamine 1.0 part, by weight
Diethanolamine 1.0 part, by weight
TCAP 2.0 parts, by weight
Polyphenylsiloxane as in
Example 1 1.0 part, by weight
Modified tolylene diisocyanate
56.3 parts, by weight
NCO/OH index 100
The following reaction times were found:
Stirring time 15"
Rise time 240"
Gel time 165"
______________________________________
The comparison foam requires considerably longer periods for rising and
hardening than the foams described in the Examples. The surface also
remains tacky for considerably longer.
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