Water-soluble, crosslinked nitrogenous condensation products produced by reaction of chlorohydrin-ethers with ethyleneimine

Water-soluble, crosslinked nitrogen-containing condensation products, the viscosity of which, in aqueous solution, increases with increasing temperature, are obtained by reacting a chlorohydrin-ether of the formula ##STR1## where x is from 50 to 250, y is from 20 to 100, the ratio x:y is from 6.1:1 to 1:15 and n is from 0.5 to 5, with ethyleneimine in the weight ratio of from 1:10.1 to 1:0.8; the condensation products are added to aqueous systems, e.g. polymer solutions and polymer dispersions, to improve the viscosity characteristics.

The present invention relates to water-soluble, crosslinked 
nitrogen-containing condensation products, the viscosity of which, in 
aqueous solution, increases with increasing temperature. 
U.S. Pat. No. 3,347,803 discloses incompletely condensed resins which can 
be cured in an alkaline medium and which are manufactured by reacting 
polyether-chlorohydrins, the polyether chain of which contains from 3 to 
70 alkylene oxide units, with polyamines or ammonia in certain molar 
ratios. The products are used as curable coatings for metal and glass, and 
as textile finishes. 
It is an object of the present invention to provide water-soluble resins, 
the viscosity of which, in aqueous solution, varies in the same sense as 
the temperature, or is virtually temperature independent. 
We have found that this object is achieved by water-soluble, crosslinked 
nitrogen-containing condensation products, the viscosity of which, in 
aqueous solution, increases reversibly with increasing temperature, and 
which are obtained by reacting a chlorohydrin-ether of the formula (I) 
##STR2## 
where x is from 50 to 250, y is from 20 to 100, the ratio x:y is from 
6.5:1 to 1:15 and n is from 0.5 to 5, with ethyleneimine in the weight 
ratio of from 1:0.1 to 1:0.8. 
Chlorohydrin-ethers of the general formula I can be manufactured by, for 
example, first forming an adduct of ethylene oxide with a polypropylene 
glycol containing from 20 to 100 propylene oxide units, under conditions 
such that the molar ratio of ethylene oxide units to propylene oxide units 
in the resulting block copolymer is from 6.5:1 to 1:15 and the degree of 
ethoxylation per hydroxyl group in the polypropylene glycol is from 50 to 
250, preferably from 75 to 150. The block copolymer is then reacted with 
epichlorohydrin in the molar ratio of from 1:1.5 to 1:6. 
To manufacture the water-soluble, crosslinked condensation products of the 
invention, the chlorohydrin-ethers of the formula I are reacted with 
ethyleneimine. The crosslinking of the chlorohydrin-ethers of the formula 
I with ethyleneimine may be carried out in aqueous solution, in alcoholic 
solution, e.g. in an alcohol of 1 to 6 carbon atoms, in emulsion, or by 
the inverse dispersion process. If the condensation is carried out in 
emulsion or in an inverse dispersion, the products of the invention are 
obtained in the form of granules, whilst in the other processes they are 
obtained as aqueous or alcoholic solutions. The crosslinking reaction 
takes place most rapidly in aqueous solution, but this frequently only 
gives very dilute solutions since the crosslinked condensates very greatly 
increase the viscosity. It is difficult to isolate the crosslinked 
products from the solutions. The crosslinking reaction may be carried out 
over a wide range of temperatures, e.g. at from 60.degree. to 140.degree. 
C., preferably from 80.degree. to 90.degree. C. 
The chlorohydrin-ethers of the formula I can also be crosslinked with 
mixtures of ethyleneimine and amines, provided the mixtures contain not 
less than 50% by weight of ethyleneimine. Examples of suitable amines are 
alkylamines, e.g. methylamine, ethylamine and butylamine, 
hydroxyalkylamines, e.g. .beta.-hydroxyethylamine or 
polyalkylene-polyamines of the formula 
EQU H.sub.2 N-[(CH.sub.2).sub.2 to 4 -NH].sub.1 to 4 H 
products according to the invention, having a particularly high viscosity, 
can be obtained by additionally crosslinking the reaction products of 
compounds of the formula I and ethyleneimine with chlorohydrin-ethers 
having a molecular weight of from 400 to 2,900 at from 60.degree. to 
90.degree. C. The crosslinking reaction may be carried out in solution, 
emulsion or inverse dispersion. The chlorohydrin-ethers which may be used 
for this subsequent crosslinking have a substantially lower molecular 
weight than the chlorohydrin-ethers of the formula I. The 
chlorohydrin-ethers acting as crosslinking agents, and having molecular 
weights of from 400 to 2,900, are manufactured, for example, by reacting 
polyglycols, e.g. polyethylene glycol, polypropylene glycol or block 
copolymers of ethylene oxide and propylene oxide with epichlorohydrin in a 
molar ratio of from 1:1 to 1:5. Such crosslinking agents are also 
described, for example, in U.S. Pat. No. 3,347,803 which is hereby 
incorporated by reference. 
Surprisingly, the viscosity of dilute aqueous solutions of the products of 
the invention increases with increasing temperature or remains 
approximately constant on increasing the temperature of the aqueous 
solution and decreases on decreasing the temperature of the solution. The 
products of the invention are employed as thickeners for aqueous systems, 
e.g. in the print pastes, paper coating compositions and emulsion paints 
or, quite generally, as anti-migration agents for aqueous solutions and 
polymer dispersions, the amounts employed being from 0.1 to 5% by weight, 
based on the aqueous solution or dispersion. Larger amounts, e.g. from 20 
to 40% by weight, of the condensation products of the invention may also 
be used. The products of the invention may be used in conjunction with any 
aqueous polymer dispersions: for example, when used in connection with the 
impregnation of non-woven fibrous products with dispersions, they ensure a 
particularly uniform distribution of the dispersion. In the coating of 
absorbent substrates, a mixture of an aqueous polymer solution or 
dispersion and the antimigration agent of the invention penetrates less 
deeply into the substrate. When the products of the invention are used in 
the paints sector, uniform application of the polymer is achieved with 
aqueous systems, and the coating can be dried at an elevated temperature 
without causing local changes in the thickness of the layer applied. 
The products of the invention are additionally used, in the form of an 
aqueous solution of from 0.1 to 5% strength by weight, as quenching baths 
for tempering steels. For example, in the Jominy end-face quenching test, 
quenching characteristics and temper curves resembling those achieved with 
tempering oils are obtained, i.e., the steel is tempered more gently than 
is feasible with pure water. Compared to the oils conventionally used for 
tempering steel, the aqueous solution of the products according to the 
invention offers substantial advantages; in particular, the aqueous 
solution is odorless and non-flammable, and rinsing-off the tempered 
workpiece is not necessary. 
The Examples which follow illustrate the invention; parts and percentages 
are by weight.

EXAMPLE 1 
A chlorohydrin-ether of the general formula I, where x is 75, y is 30, the 
ratio x:y is 2.5:1 and n is 2, is prepared by adding 9 g of 
epichlorohydrin, followed by 5 g of boron trifluoride-etherate, to 2,500 g 
of a polyether-diol of the formula 
##STR3## 
where x is 75 and y is 30, at 75.degree. C. After about 15 minutes, 75 g 
of epichlorohydrin are added, as a single portion, to the batch. After a 
reaction time of 4 hours at 75.degree. C., all the epoxide has been 
converted. 
600 g of the resulting chlorohydrin-ether are then dissolved in 600 g of 
water. The solution is heated to from 70.degree. to 90.degree. C. and 360 
g of a 50% strength aqueous ethyleneimine solution are added in the course 
of 90 minutes. The reaction mixture is kept at 80.degree. C. for a further 
4 hours and is then diluted with water to give a 20% strength aqueous 
solution. The viscosity of the aqueous solution at 20.degree. C. is 130 
mPas, whilst at 50.degree. C. it is 2,400 mPas. 
The water-soluble, crosslinked nitrogen-containing condensation product is 
used as an additive in water-based paints, in an amount of 2% based on the 
paint. 
EXAMPLE 2 
600 g of a 10% strength aqueous solution of the crosslinked, 
nitrogen-containing condensation product described in Example 1 are 
reacted at 70.degree. C. with 180 g of a 10% strength aqueous solution of 
a chlorohydrin-ether of the general formula 
##STR4## 
where x is 34 and n is 1.6. The reaction takes 5 hours. During the 
reaction, water is added so that a 4% strength aqueous solution of the 
reaction product is obtained. This solution has a viscosity of 200 mPas at 
20.degree. C. 
The resulting product is used, as an 0.5% strength aqueous solution, as a 
quenching bath for tempering steels. When tempering a K8, 30 Cr Mo V9 
steel, a tempering curve (Vickers hardness as a function of the quenched 
surface) is obtained which is similar to that obtained on tempering with 
quenching oil and is thus substantially below the curve for pure water. 
EXAMPLE 3 
14 g of epichlorohydrin and 10.4 g of boron trifluoride-etherate are added, 
at 65.degree. C., to 4,164 g of a polyether-diol of the general formula 
II, where x is 113 and y is 44. After 15 minutes, 125 g of epichlorohydrin 
are added. The reaction mixture is heated for 4 hours at 75.degree. C. A 
chlorohydrin-ether of the formula I, where x is 113, y is 44, n is 3.5 and 
the ratio x:y is 2.56:1 is obtained. 
150 g of the chlorohydrin-ether are then dissolved in 150 g of water and 45 
g of a 50% strength aqueous ethyleneimine solution are added at 80.degree. 
C. The reaction is complete after eight hours. Since the viscosity of the 
reaction mixture rises during crosslinking, it is advisable to dilute the 
reaction mixture with water, during the reaction, to a solids content of 
10%. The viscosity of the 10% strength solution is about 4,500 mPas at 
50.degree. C. and 1,200 mPas at 20.degree. C. 
If a glass fiber web is impregnated with a dye dispersion to which 0.2% of 
the crosslinking product has been added, the dye is absorbed uniformly and 
after drying the web exhibits a level shade. No dye agglomerates form even 
at the cross-over points of the glass fibers in the web. 
EXAMPLE 4 
200 g of the chlorohydrin-ether described in Example 1 and 100 g of a 
chlorohydrin-ether of the general formula I, where x is 13.5, y is 30, the 
ratio x:y is 1:2.2 and n is 1.2 are mixed and dissolved in 300 g of water. 
180 g of a 50% strength aqueous ethyleneimine solution are then added at 
80.degree. C., and the reaction mixture is kept for 6 hours at from 
80.degree. to 90.degree. C. and is then diluted with water so as to give a 
10% strength aqueous solution of the cross-linked, nitrogen-containing 
condensation product. The viscosity of the 10% strength solution is 140 
mPas at 20.degree. C. and 1,200 mPas at 50.degree. C. 
The resulting aqueous solution of the nitrogen-containing condensation 
product is used in an amount of 3% as an antimigration agent for a 
styrene-butadiene-acrylic acid copolymer dispersion employed for 
impregnating webs. 
EXAMPLE 5 
1,200 ml of octane are mixed with 30 g of a commercial oxyalkylated 
alkylphenol (as an emulsifier) and 30 g of water. An aqueous solution of 
225 g of the chlorohydrin-ether described in Example 1 is then added with 
vigorous stirring at from 80.degree. to 95.degree. C., followed by 22.5 g 
of ethyleneimine dissolved in 600 g of water. After a reaction time of 18 
hours at 85.degree. C., the water is separated off. The condensation 
product hereupon separates out as fine granules. The viscosity of a 10% 
strength aqueous solution is 50 mPas at 20.degree. C. and 90,000 mPas at 
80.degree. C. 
EXAMPLE 6 
6 g of diethylenetriamine, 6 g of concentrated hydrochloric acid, 24 g of 
ethyleneimine and 150 g of the chlorohydrin-ether described in Example 3 
are introduced into a flask. 800 ml of octane and 40 g of water are then 
added. The resulting coarse dispersion is stirred vigorously for 20 hours 
at 80.degree. C. A nitrogen-containing water-soluble condensation product 
is obtained, which on cooling the dispersion separates out as coarse 
granules. The condensation product can be isolated easily. A 10% strength 
aqueous solution of the product has a viscosity of 500 mPas at 20.degree. 
C. and of more than 100,000 mPas at 50.degree. C. 
The condensation product is used to prepare non-migrating solutions and 
polymer dispersions. If, for example, a web is impregnated with a 
butadiene-styrene copolymer dispersion of about 25% strength, the excess 
dispersion is squeezed off between two rollers and the web is dried at an 
elevated temperature, the polymer of the dispersion is found to have 
coalesced into large drops which have migrated to the surface of the web 
so that the polymer is non-uniformly distributed. 
If, on the other hand, 0.5%, based on solids, of the nitrogen-containing 
condensation product described above is added, in aqueous solution, to the 
25% strength butadiene-styrene polymer dispersion and the impregnation of 
the web is repeated, using the same procedure, the polymer of the 
dispersion is found to be uniformly distributed even after squeezing off 
and drying the web. 
The polymer dispersion behaves similarly when sprayed onto a web. Only if 
the crosslinked, water-soluble nitrogen-containing condensation product 
has been added to the polymer dispersion does the binder remain uniformly 
distributed on the web. 
EXAMPLE 7 
6 g of diethylenetriamine, 6 g of concentrated hydrochloric acid, 24 g of 
ethyleneimine and 150 g of the chlorohydrin-ether described in Example 3 
are introduced into a flask. An emulsion of 40 g of water in 400 ml of 
octane, containing 20 g of an emulsifier (HLB value 4) is then added. 
After a reaction time of 18 hours at 85.degree. C., fine, porous granules 
separate out on cooling the reaction mixture. The viscosity of a 10% 
strength aqueous solution is above 100,000 mPas at 50.degree. C., whilst 
at 20.degree. C. it is only 80 mPas. The cross-linked, water-soluble 
condensation product obtained is employed as a thickener in water-based 
paints.