Method of and apparatus for producing a foamed mass of a polyurea elastomer

Through three separate passages opening in a common plane at right angles to one another into a mixing chamber, three components of a reactant polyurethane or polyurea elastomer composition to form in a mold cavity are introduced. One of the components is an aliphatic polyether amine having primary amino function and substantially free from free hydroxyl groups, catalysts with tertiary amino groups, carbon dioxide as a carbamate reactive with the polyether amine and optionally other inert gases and conventional polyurea additives. The second component is a polyisocyanate or prepolymer thereof and the third component C is water. The reacting mixture is formed through a throttle gap into the mold to form low-density foamed products under low fuming conditions and has no unreacted diisocyanates.

FIELD OF THE INVENTION 
My present invention relates to a method of and an apparatus for producing 
a foamed mass of a polyurea elastomer basis and, more particularly, to the 
production of polyurea elastomers in an environment in which a foaming of 
the mass can be effected. 
BACKGROUND OF THE INVENTION 
In the production of foamed products, polyurethanes have been found to be 
highly advantageous because of their versatility and their ability to be 
matched to the production requirements and the product requirements. As a 
result, foamed polyurethanes have achieved world-wide significance in the 
industrial polymer field. The production of polyurethanes utilizes a 
variety of techniques. 
One of the most important factors in modern polyurethane technology is the 
need to avoid the use of fluorochlorohydrocarbons as expanding or foaming 
agents, because of the detrimental effect of such compounds upon the 
environment. More expensive replacement products may be uneconomical. 
The use in the past of halogen-free foaming agents, especially carbon 
dioxide on ecological grounds, has been found to be desirable although 
economic factors have hitherto made such use less than attractive. In 
spite of considerable research, the use of carbon dioxide frothing as a 
replacement for fluorochlorohydrocarbon foaming has not been found to be 
fully satisfactory as will be apparent from M. Taverna, Conference paper 
UTECH 1990, pages 70-73. 
Problems have also been encountered with other expanding gases used in 
foaming, particularly with respect to changes in polyurethane technology 
which are required when such gases are used. For example, an improvement 
in product quality is required, for instance to drastically increase the 
life span of the molded products which are produced. It is also necessary 
to improve the load-carrying capacities of such products and the aging 
characteristics thereof. 
Apart from quality factors, a reduction in the problem with respect to 
fumes and fogging in the industrial application of polyurethanes, which 
also can affect the consumer, is necessary. For example, efforts have been 
required to ensure that all of the additives which are not chemically 
fixed in the polymer matrix should be removed or eliminated to avoid the 
fume or fogging problems. As a practical matter, therefore, aspects of 
workplace hygiene, toxicology and ecology have affected the industry 
detrimentally. Nonreacted isocyanates, phthalates serving as solvents for 
certain additives, partly volatile metallo-organic compounds and even 
certain amine catalysts have contributed to these problems. 
However, the efforts to avoid volatile components as much as possible 
during production and in the finished product have not resulted in 
qualitative improvements in the products. They have been only limitedly 
successful in workplace improvements from the aspect of hygiene, 
toxicology and ecology. Nevertheless considerable efforts are being 
expended in this aspect of foam plastic technology. 
There is a considerable world-wide effort under way to find new raw 
materials with the aid of which the aforementioned problems in foam 
technology can be resolved. For example, considerable effort is under way 
to develop high molecular weight polyols a starting materials for 
polyurethane foam technology. 
In more recent technical literature, a trend can be discerned toward the 
use of polyether amines as reaction components for use in the production 
of polyurethanes. By contrast to classical polyols which have at least two 
free hydroxyl groups per molecule, the polyether amines have, instead of 
free hydroxyl groups or residues, primary or secondary aliphatic amine or 
primary aromatic ammine residues. 
In R.D. Priester, R.D. Peffley and R.B. Turner; Proceedings of the SPI-32nd 
Technical Marketing Conference, San Francisco, 1989, the use of 
aminopolyols with secondary aliphatic or primary aromatic amino 
functionality, is described for the production of foamed polyurea 
compositions of low bulk density. It has been shown that these materials 
have significant advantages by comparison with conventional polyurethane 
foam components in many ways. 
These advantages include increased load-carrying capacity and improved 
aging characteristics as well as an improvement in resistence to 
flammability. 
In EP-A 0 279 536, long-chain aliphatic oligofunctional secondary amines 
are reacted with polyisocyanates in the presence of conventional catalysts 
and additives to produce polyurea foams which are not further 
characterized. 
This technique is characterized by improvement in many of the requirements 
outlined above and thus is considered a true advance in the art. However, 
it does not satisfy the need to eliminate classical additives such as 
tin-containing compounds and amine catalysts which contribute to the 
toxicity and fogging problems noted above. Furthermore, the technique has 
a further disadvantage which has limited its applicability, namely, the 
problem of obtaining the polyether amines. Up to now the production of 
polyether amines by simple methods which are both economically and 
technologically suitable for widespread use in polymer technology has not 
been possible. This disadvantage results in means that the raw material 
caused output and/or the chemical integrity of the resulting product could 
not be guaranteed. 
The production and use of mixtures of polyether amines having secondary 
amine functional groups in the production of foamed polyurea compositions 
is described at many locations in the literature. Large-chain aliphatic 
oligofunctional primary amines (U.S. Pat. No. 3,654,370) can be subjected 
to reaction by alkoxylation, cyanethylation, alcohol aminylation and 
reductive catalytic aminylation. 
Alternatively, short-chain primary aliphatic amines can be subjected to a 
catalytic reaction with polyoxyalkylene compounds (U.S. Pat. No. 
3,654,370) to long-chain aliphatic oligofunctional secondary amines (U.S. 
Pat. No. 4,904,705). 
It has been proposed further to produce aromatic polyether amines in a 
variety of processes, for example, by reacting commercially-available 
polyhydroxy polyethers with isatic acid anhydride in one or more steps. In 
this sense, DE-A 29 48 419 describes the transformation of 
commercially-available polyhydroxy polyethers with aromatic diisocyanates 
into prepolymers, with subsequent hydrolysis of the remaining isocyanate 
products to yield an aminopolyol with terminal amino groups bound to 
aromatic residues. 
In the polymer chemical field it is known that the product characteristics 
of polymers can be better controlled and influenced if the raw materials 
used are homogeneous and invariant. This applies as well for the 
formulation and product characteristics of polyurethane polymers under 
discussion. It is, therefore, important to avoid statistical distribution 
and differently substituted amines in the raw materials employed and this 
can be achieved by utilizing reactive terminal groups. 
With the teachings of DE-A 38 25 637, albeit at increased cost, it is 
possible to obtain highly uniform and invarient, long-chain aliphatic 
oligofunctional secondary amines. This is achieved by hydrogenation of 
Schiff bases produced from ketones and oligofunctional primary 
polyoxypropylene amines. 
Oligofunctional polyoxypropanol amines with terminal primary amine groups 
are used in accordance with DE-A 38 25 637 to produce polyether amines 
with secondary amino groups and are commercially available under the 
designation JEFFAMINE.RTM. (Texaco). The molecular weight of this starting 
material is in the range of 230 to 8,000 and its amine functionality lies 
between 1 and 3. 
These compounds are produced, for example, as described in U.S. Pat. No. 
3,654,370, in a single step from commercially-available petrochemical 
compounds, namely, dioxypropylenepolyols and ammonia. 
A direct use of such products for the production of foamed polyurea 
compositions of low bulk density is advantageous on both economical and 
technological grounds because these compounds have an especially high 
degree of amination and high compositional consistency with respect to 
their terminal groups. It is also an advantage that the formation of 
polyol compounds does not result in a significant reduction of esters, 
urethanes or ethoxy residues; indeed these residues can be completely 
avoided in most instances. 
In the literature, the use of aliphatic polyether amines with primary amino 
function is described for the production of hard elastic foamed polyurea 
compositions of high bulk density. In fact, the literature teaches that 
the extremely high reactivity of these polyether amines precludes the 
formation of foamed polyurea compositions of low bulk density. 
In the production of "foamed" polyurea compositions with such high bulk 
densities (800 to 1,300 kg/m.sup.3), the reaction times of a maximum of 2 
to 3 seconds must be observed with the use of such primary oligofunctional 
long-chain aliphatic amines, because the liquid raw material solidifies in 
such a short time into solid and no longer flowable masses. 
In EP-A 0 081 701 and U.S. Pat. No. 4,269,945, the addition of a blowing or 
foaming agent to this process is described. The result is an improvement 
in the product characteristics, namely, the surface quality of the hard 
elastic foam body which results. With this approach, microcellular "foams" 
can be obtained with a high bulk density of greater than 800 kg/m.sup.3. 
In this process, the use of permanent dried gases, especially nitrogen or 
air, has been found to be advantageous. The process has been described as 
"nucleation". While in connection with this approach, the use and/or 
collateral effect of autogenously produced carbon dioxide has been 
proposed it has not resulted in any practical applications because it has 
been accompanied in the past with an extremely rapid reaction rate 
predominantly causing the reaction mixture to harden into a nonflowable 
mass. The velocity of the reaction is far more rapid than the much slower 
catalytic reaction of water with isocyanates. 
U.S. Pat. No. 4,910,231 describes the reaction of a primary amino group 
containing polyether amines with an excess of polyisocyanate and water to 
form a hard foam which is not unlike the hard foams described with their 
disadvantages. 
OBJECTS OF THE INVENTION 
It is the principal object of the present invention, therefore, to provide 
an improved method or process for the formation of polyurea/polyurethane 
foams from polyether amines with primary amino groups and polyisocyanates 
to yield, with sufficient reaction time and a more satisfactory reaction 
rate, foamed products with lower density and more advantageous properties 
as regards freedom from the release of toxic substances, elasticity, 
demoldability, content of unreacted diisocyanates and the like by 
comparison with earlier processes. 
Another object of this invention is to provide an improved apparatus for 
producing improved foam polyurea compositions with the latter advantages. 
Still another object of the invention is to provide a method of producing 
polyurea foams whereby drawbacks of earlier techniques are avoided. 
SUMMARY OF THE INVENTION 
These objects and others which will become apparent hereinafter are 
attained, in accordance with the invention, in a process for producing a 
foamed composition based upon polyurea elastomers and in which, with 
intensive mixing, there are reacted: 
(a) aliphatic polyether amines, with primary amino functionality and 
substantially devoid of free hydroxyl groups, 
(b) polyisocyanides including prepolymers thereof, 
(c) water, and 
(d) catalysts with tertiary amino groups, in the presence of 
(e) carbon dioxide and optionally other, inert halogen-free gases and 
optionally also in the presence of 
(f) customary polyurea additives whereby the carbon dioxide at least partly 
is formed by the reaction of carbamate with the aliphatic polyether amines 
and in which the intensive mixing is effected through the use of a mixing 
head with 
(g) a cylindrical mixing chamber, 
(h) three component supply ducts or passages for the components A, B and C, 
whereby component A consists of the reactants a, d, e and f with the 
carbon dioxide present as a carbamate reacting with aliphatic polyether 
amine, the component B as the substance d and the component C as water, 
(i) a reversible displaceable piston is provided in the mixing chamber for 
synchronous control of the passage opening into the mixing chamber and 
(k) a throttle gap is provided at the outlet opening of the mixing chamber. 
Stated otherwise, the method can comprise the steps of: 
(a) forming a component A by combining at least one aliphatic polyether 
amine having primary amine functional groups and substantially devoid of 
free hydroxyl groups, a catalyst for polyurea elastomer formation having 
tertiary amino groups, carbon dioxide at least in part produced by 
reaction of carbamate with the aliphatic polyether amine and optional 
inert gases, and optional polyurea additives; 
(b) forming a component B as a polyisocyanate reactive to produce the 
polyurea elastomer or a prepolymer of the polyisocyanate; 
(c) forming as a component C, water reactive to produce the polyurea 
elastomer; 
(d) separately continuously feeding the components A, B and C through three 
separate passages into an elongated mixing chamber of a mixing head having 
a mixing chamber piston displaceable in the mixing chamber, and 
intensively mixing the components A, B and C in the chamber to form a 
mixture; 
(e) controlling the feeding of the components A, B and C into the mixing 
chamber from the passages by axially shifting the mixing chamber piston 
therein; 
(f) discharging the mixture from a mouth of the mixing chamber into a 
discharge chamber; 
(g) during discharge of the mixture from the mixing chamber into the 
discharge chamber, partly obstructing the mouth to form a throttle gap 
through which the mixture is forced; and 
(h) delivering the mixture from the discharge chamber into a chamber to 
enable the mixture to foam into a mass of the polyurea elastomer. 
Preferably the pressure in the component feed passages directly before they 
open into the mixing chamber is between 80 and 180 bar. Most 
advantageously, the pressure in the component passages for components A 
and B immediately upstream of their discharge into the mixing chamber 
ranges from 140 to 160 bar and the pressure in the passage for component C 
directly before it opens into the mixing chamber is in the range of 80 to 
110 bar. 
Advantageously, the temperature of the components A, B and optionally C 
directly before discharge into the mixing chamber is in the range of 
20.degree. to 60.degree. C. From the point of view of product quality, it 
is most advantageous to provide for the component C a temperature in the 
range of 90.degree. to 120.degree. C. 
The components A, B and C are fed at such rates and the mixing chamber and 
the throttle gap are so diminished that the outlet or discharge velocity 
of the component mixture is in the range of 8 to 16 m/s. 
According to the apparatus aspect of this invention, the throttle gap is 
formed by a transverse slider in the discharge chamber into which the 
mixing chamber opens at a right angle. Alternatively that throttle gap is 
formed by a constriction in the flow passage of the die or mold into which 
the foamable mass is injected for foaming. 
The apparatus can comprise: 
means forming a cylindrical mixing chamber having a mouth at one end, a 
mixing chamber piston displaceable from an opposite end in the mixing 
chamber and a mixing region between the mouth and the piston; 
a first passage opening into the mixing region for feeding thereto a 
component A formed by combining at least one aliphatic polyether amine 
having primary amine functional groups and substantially devoid of free 
hydroxyl groups, a catalyst for polyurea elastomer formation having 
tertiary amino groups, carbon dioxide at least in part produced by 
reaction of carbamate with the aliphatic polyether amine and optional 
inert gases, and optional polyurea additives; 
a second passage opening into the mixing region for feeding thereto a 
component B formed from a polyisocyanate reactive to produce the polyurea 
elastomer or a prepolymer of the polyisocyanate; 
a third passage opening into the mixing region independently of the first 
and second passages and in addition thereto for feeding into the region as 
a component C, water reactive to produce the polyurea elastomer, the 
components A, B and C intensively mixing in the chamber to form a mixture; 
means for controlling the feeding of the components A, B and C into the 
mixing chamber from the passages by axially shifting the mixing chamber 
piston therein, the mixture being discharged from the mouth of the mixing 
chamber; and 
means for partly obstructing the mouth to form a throttle gap through which 
the mixture is forced into a chamber to enable the mixture to foam into a 
mass of the polyurea elastomer. 
When a calming chamber is used with a larger cross section than the mixing 
chamber, it also can be provided with a reversible piston or plunger which 
can be positioned ahead of the mouth of the mixing chamber to form the 
adjustable throttle gap. 
It has been found to be advantageous to have the component passages located 
in the same plane but at angles of 90.degree. between them. 
The polyether amines which may be used can be aliphatic polyether amines 
known in the art and substantially devoid of free hydroxyl groups and 
whose amino functions are primary amine groups. Mixtures of these 
aliphatic polyether amines can be used. The polyether amines can include 
other polyether amines which are free from hydroxyl groups and can have 
secondary amino functionality, such other polyether amines also being 
known in the art but can be present only in an amount up to 65% of the 
aliphatic polyether amine with primary amino function. Upon the addition 
of such secondary polyether amines, which are less reactive than the 
primary aliphatic polyether amines, the reaction time to achieve the 
desired product characteristics may have to be adjusted. 
Preferably the polyether amines corresponding to the Formula I 
EQU R.sup.2 ([O--(CH.sub.2m)--CHR.sup.1 ].sub.n [O--(CH.sub.2).sub.3 --].sub.o 
--NH.sub.2).sub.p I 
in which 
R.sup.1 is hydrogen and m an integer which may be 1 or 3 or 
R.sup.1 is methyl and m is the integer 1, 
n is an integer in the range of 1 to 100 o is 0 or 1 
and 
R.sup.2 is a di-bonding residue according to one of the Formulas IIa to IIc 
EQU --CH.sub.2 --CHR.sup.3 -- (IIa) 
EQU --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 -- (IIb) 
EQU --CHR.sup.3 CH.sub.2 --NH--CO--NH--CH.sub.2 --CHR.sub.3 -- (IIc) 
in which 
R.sup.3 is hydrogen or methyl, 
and p is the number 2 or 
R.sup.2 is a tri-bonding residue according to one of the Formulas IIIa to 
IIIc: 
EQU CH.sub.3 --C(CH.sub.2 --).sub.3 (IIIa) 
EQU CH.sub.3 --CH.sub.2 --C(CH.sub.2 --).sub.3 (IIIb) 
EQU (--CH.sub.2).sub.2 CH-- (IIIc) 
and p is the number 3. 
The production of the polyetheramine of Formula I is described, for 
example, in U.S. Pat. No. 3,654,370. As there described, 
polypropyleneglycolether is reacted with ammonia and hydrogen in the 
presence of appropriate catalysts. The functionality of the resulting 
products can be influenced by introducing as starters for the 
polypropyleneglycolether, low molecular weight diols or triols. Usually 
these are ethyleneglycol, propyleneglycol, butanediol, glycerine, 
trimethylpropane and the like which are initially ethoxylated and/or 
propoxylated. These compounds can be "the JEFFAMINE polyoxyalkylene 
amines", distributed by Texaco Chemical Company, Houston, Tex. 
Other starters which can be used include polyethyleneglycol or polymerized 
1,4-butanediol which can be subjected to propoxylation and which may be 
employed to modify the crystallinity, flexibility and/or water take-up 
characteristics of the product. 
In the process of the present invention, polyether amines can be employed 
which have primary amino function and which are the result of 
cyanoethylation of polyhydroxypolyols with acrylonitrile and subsequent 
catalytic reduction (see DE-B 1 193 671). Other processes for producing 
the polyether amine with primary amino function as can be used in the 
present invention are described in U.S. Pat. No. 3,155,728, U.S. Pat. No. 
3,236,895 and FR-A 1,551,605. 
Especially preferred polyether amines with primary amino groups are those 
which predominantly or exclusively contain propyleneoxy groups, i.e. those 
which are propyleneoxide compounds in which the propyleneoxy groups have 
replaced reactive hydroxy groups since these produce products with the 
best characteristics, i.e. reduced water pick-up, high flexibility, etc. 
If it is desirable for the foamed product to have a high water pick-up and 
an increased crystallinity, polyether amines with primary amino groups are 
employed which have a greater proportion of ethyleneoxy or butyleneoxy 
units or only such units, optionally in admixture with the aforedescribed 
polyether amines with propyleneoxide units. 
As has already been indicated, together with a primary amino function, we 
may add secondary amino function polyether amines. The latter can be of 
the type described in U.S. Pat. No. 3,666,788, U.S. Pat. No. 3,155,728 and 
German Patent document DE-A 38 25 637. With the use of these accompanying 
polyether amines, the following terminal group and/or residue substituents 
are preferably employed: 2-hydroxyethyl, 2-hydroxypropyl, propionitrile or 
the alkyl residues n-butyl s-butyl, i-butyl, 1,3-dimethyl-1-pentyl and 
cyclohexyl. 
As has also been stated previously, the preferred aliphatic polyether 
amines with primary amino groups which are used according to the 
invention, are those which contain propyleneoxy units in accordance with 
the Formula I and best results are obtained where R.sup.1 is methyl, n is 
1 and R.sup.2, R.sup.3, n, o and p are as defined above. 
According to a further feature of the invention, polyether amines with 
primary amino groups which are used have molecular weights in the range of 
200 to 12,000. 
The polyisocyanates used in accordance with the invention can have, as 
carrier groups, aromatic, aliphatic and/or mixed aliphatic/aromatic 
groups. Typical examples of the polyisocyanate compounds used in 
accordance with the invention are straight-chain aliphatic diisocyanates 
like 1,4-diisocyantobutane, 1,5-diisoscyanatopentane, 
1,5-diisocyanatohexane or the like. 
The cycloaliphatic diisocyanates are preferably 1,4-diisocyantocyclohexane 
or isophoronodiisocyanate or isomer mixtures thereof. A variety of 
aromatic diisocyanates ca also be included. Suitable isomer mixtures are 
mixtures of 2,4-diisocyantotoluene and/or 2,6 diisocyanatotoluene 
(so-called TDI isomer mixtures), isomer mixtures of 2,2'- or 2,4'- and/or 
4,4' diisooyanatodiphenylmethane (so called MDI isomer mixtures), isomer 
mixtures containing 2,4-diisocyanato-1-chlorobenzene and isomer mixtures 
of diisocyanatoxylenes and the like. A detailed listing of commercially 
available suitable polyisocyanates can be found at G. Oertel, 
Kunststoffhandbuch, Band VII (Polyurethane), Carl-Hanser-Verlag, Munchen 
und Wien 1983, especially at pages 63-73 thereof. Preferred are the 
aforementioned TDI and MDI types and especially the MDI types, optionally 
in admixture with the TDI type. 
With the MDI types, preferably such mixtures are used which contain either 
reduced quantities of high homologs resulting from the synthesis of these 
compounds or carbodiamide derivatives of commercially available MDI-type 
compounds and is likewise a commercial product. 
In the diisocyanate compound, we include prepolymers, especially MDI 
prepolymers such as described in U.S. Pat. No. 4,737,919 and which can be 
obtained by reacting diisocyanates and primary long-chain aliphatic 
amines. It has been found to be advantageous, in accordance with the 
invention, that these products need not be separately produced and 
recovered but can be generated during the injection process in a suitable 
device in an "on-line" manner. 
The prepolymers can also be added in admixture with the "monomeric" 
polyisocyanates. 
Workers in the art are aware that, to generate optimum characteristics in 
the foamed polyurethane plastics, so-called "hard segments" must be 
obtained in the polymer matrix on morphological grounds. It is further 
known that, for this purpose, especially aromatic polyisocyanates can be 
reacted with water with the aid of appropriate catalysts. In the course of 
this reaction of the polyisocyanates and water, carbamic acid which 
results from a dicarboxilation of the primary aromatic amine and carbon 
dioxide are formed. While the primary aromatic amine reacts spontaneously 
with further isocyanate to form polymeric urea compounds, constituting the 
hard segments, the autogenously-generated carbon dioxide forms an 
expanding gas. It is, therefore, possible to utilize this technique for 
producing the entire quantity of the expanding gas of the invention but 
with the disadvantage that an undesirable high proportion of the hard 
segment will result. 
For ideal product properties, therefore, it is advantageous to avoid 
generating excessive proportions of the hard segment and hence 
autogenously-formed expanding gases, so that the residual requirements for 
expanding gas according to the prior art, is usually supplied by easily 
vaporizable liquids. For this purpose, in the past 
fluorochlorohydrocarbons have been used. 
One of the advantages of the invention, pointed out above, is that such 
fluorochlorohydrocarbons need not be used, and it is an important aspect 
of the invention that carbon dioxide is used as the expanding agent 
optionally in the presence of inert gases like nitrogen or air. 
According to the invention, these gases can be supplied with precisely 
predetermined quantities to the polyether amine component under pressure. 
While there will be a reaction of at least a part of the supplied carbon 
dioxide with the polyether amines to form carbamates, this serves to 
reduce the extreme radioactivity of the polyether amines to a practical 
level. The mixture will contain, optionally, carbon dioxide bonded to the 
carbamate apart from dissolved carbon dioxide. The nucleated polyether 
amine which thus results is then fed to the reaction system through the 
respective passage. This ensures that during the foaming phase, there will 
not be an uncontrolled loss of gas during the mixing. 
In the process of the invention, moreover, there is also a formation of 
hard segment components by the catalytic decomposition of excess 
isocyanate with water. For this purpose, such catalysts are used which 
accelerate the isocyanate-water reaction as selectively as possible. The 
catalysts are from the class of blowing catalysts which have a boiling 
point of at least 190.degree. C. or chemically are bound in the polymer 
matrix. These characteristics are important for effecting the process of 
the invention as well as of great significance in avoiding or reducing 
toxic emissions and the fogging characteristics of the foamed products. 
The preferred catalysts are those used in polyurethane chemistry and are 
tertiary amines. The types and effects are found in "Kunststoffhandbuch", 
Band VII (Polyurethane), especially at pages 92-98. 
According to a preferred embodiment of the invention, the catalysts having 
tertiary amino groups conform to the Formula IV 
EQU X--CH.sub.2 --CH.sub.2 --M--CH.sub.2 --CH.sub.2 --Y (IV) 
in which M is an oxygen atom or a methylamino group X and Y can be the same 
or different and are selected from the group which consists of 
N-morpholinyl-,N-azanorbornyl-,dimethylamino and dimethylaminoethyl groups 
or X is one of these groups and Y is an hydroxyl group or an 
N-methyl-N-(2-hydroxy-C.sub.1 - to C.sub.2 -alkyl)-amino group. 
Especially preferred catalysts include 2,2-dimorpholinoethylether, 
2-(2-dimethylamino)ethoxyethanol, bis-(2-dimethylaminoethyl-)ether, 
2-(2-dimethylaminoethyl-)-2-methylaminoethanol and 
2-(2-(dimethylaminoethoxy)-ethyl-methyl-aminoethanol. 
Typical examples of the catalysts are: 
Bis-(2-dimethylaminoethyl-)ether 
2,2-dimorpholinodiethylether 
2-(2-(dimethylaminoethoxy)-ethyl-methyl-amino-ethanol 
2-(2-dimethylaminoethoxy-)ethanol 
N,N,N',N',N"-pentamethyldiethylantriamine 
Bis-(azanorbornylethyl-)ether, (DE-A 37 07 911) 
2-(2-hydroxyethoxy-)ethyl-azanorbornane, (DE-A 37 07 911) 
2-(2-dimethylaminoethyl-)-2-methylaminoethanol 
N,N,N'-trimethyl-N'(ethoxyethanol)ethylendiamine. (U.S. Pat. No. 4,582,983) 
2,5,11-trimethyl-2,5,11-triaza-8-oxa-dodecane (U.S. Pat. No. 4,582,983). 
(Unless otherwise indicated, the compounds are commercially available.) 
A highly preferred catalyst containing a tertiary amino group is 
2,2,4-trimethyl-1-oxa-2-sila-4-aza-cyclohexane. 
According to a particularly advantageous embodiment of the invention, the 
catalyst or catalysts can be used in amounts of 0.01 to 5 phr with respect 
to the polyether amine. The catalysts are preferred dissolved in water and 
supplied to the reaction system as aqueous solutions. The quantity of 
water is so calculated that it conforms to an aliquot of the 
polyisocyanate quantity required for formation of the desired amount of 
the hard segment and to produce autogenously the blowing gas. The quantity 
of water actually used can be a many-fold excess over this quantity. 
Since, according to the invention products which are especially fume-free 
can be generated, it has been found that many of the catalysts which have 
been found to be problematical in the polyurethane field because of their 
fume activity, for example 1,4-diazabiacyclo(2,2,2)octane, 
dimethylethanolamine, dimethylcyclohexylamine, methylazanorbornane and the 
like, can be employed. 
According to a further feature of the invention, apart from the so-called 
blowing catalyst mentioned above, other catalysts are not required 
although it was common practice in polyurethane chemistry to employ such 
other catalysts, for example, metallo-organic catalysts. As we have 
indicated previously, it is not a disadvantage that a water excess is 
present over the amount calculated to be necessary. As a consequence, the 
free polyisocyanate content in the end product can be reduced to a 
minimum. 
In the process of the invention, conventional polyurethane or polyurea 
additives can be employed as is described at Kunststoffhandbuch, Band VII 
(Polyurethane), especially pages 100 to 109 thereof. Typical examples of 
such additives are foam stabilizers, antiflammability agents, antiaging 
agents, inert mineral inorganic or organic fillers, inert parting agents 
enabling separation of the foamed mass from the mold in which it is 
injected, and the like. 
For carrying out the process of the invention, we preferably use a mixing 
head of the type described in German Patent 23 27 269 or as described in 
the aforementioned publication of M. Taverna, especially page 70. This 
mixing head need be modified only to provide a further inlet for the 
water/catalyst mixture. According to the invention, separate streams of 
the aliphatic polyether amine containing carbon dioxide bound up as 
carbamate and optionally soluble carbon dioxide inert halogen-free blowing 
gases as well as possible conventional polyurea additives, the 
polyisocyanate including prepolymers thereof and the catalyst in admixture 
with water so that the resulting mixture is formed within the cylindrical 
mixing chamber. The reactive mixture flows from the mouth of the mixing 
chamber through the throttle gap. It is thus possible to supply the 
catalyst separately or in whole or in part together with the polyether 
amines. 
To reduce the Viscosity and/or adjust the reaction time, it is advantageous 
to heat the reagent streams before they enter the chamber. 
It has also been found to be advantageous to carry out the reaction at 
superatmospheric pressure. 
With the use of a mixing head having a throttle gap in the manner 
described, foamed elastic polyurea losses of a bulk density in the range 
of about 20 to 300 g/l can be produced. The streams of the components of 
their action can interact in a one-shot system according to the invention. 
SPECIFIC EXAMPLES 
In the following examples, the process is carried out in a mixing head of 
the type illustrated in FIGS. 1 and 2 and described below, the mixing head 
having three separate feed passages for three different streams. 
EXAMPLE 1 
______________________________________ 
Material Weight % Density 
______________________________________ 
Stream 1: 
Jeffamine T 5000.sup.1) 
80 
Jeffamine D 2000.sup.2) 
2 
Tegostab B 4690.sup.3) 
1 
Texacat ZF 20.sup.4) 
0.1 
Carbon dioxide 2.7.sup.5) 
103.8 1.034 
Stream 2: 
Suprasec VM 25.sup.6) 
54 1.175 
Stream 3: 
Water 4 1.000 
______________________________________ 
.sup.1) Product of Texaco Chemical Company, polyoxypropylenetriamine, 
amine equivalent: 52 mVal/g 
.sup.2) Product of Texaco Chemical Company, polyoxypropylenediamine, amin 
equivalent: 98 mVal/g 
.sup.3) Product of Th. Goldschmidt AG, Silicone 
.sup.4) Product of Texaco Chemical Company, 
Bis(2-dimethylaminoethyl-)ether 
.sup.5) At a nitrogen pressure of 5 bar, gaseous carbon dioxide is 
introduced until the volumetrically calculated amount has been taken up. 
.sup.6) ICI modified MDI 24.3 weight % NCO content. 
The streams 1, 2 and 3 are combined in the high-pressure mixing head to 
produce a compact foamed material in a closed mold after injection. 
______________________________________ 
Test 1 
Test 2 
______________________________________ 
Components 
Temperature, .degree.C./Pressure (bar) 
Stream 1 40/150 43/150 
Stream 2 28/150 30/150 
Stream 3 20/90 50/90 
Outlet velocity at throttle 
12 m/s 
gap of mixing heat 
Mold temperature, .degree.C.: 
70 70 
Injection weight, g: 500 450 
Mold volume, ml: 7320 7320 
Mold rise time, Sec.: 
40 36 
Tack-free time, Sec.: 
180 170 
Removal time, Sec.: 240 240 
Bulk density, kg/m.sup.3 : 
65 57 
after compression and cooling. 
______________________________________ 
Molar ratio of NH.sub.2 groups of the polyether amine to the NCO groups in 
this example was 1:5.12 and the molar ratio of the surplus NCO groups to 
water was 1:1.77. 
EXAMPLE 2 
______________________________________ 
Material Weight % Density 
______________________________________ 
Stream 1: 
Jeffamine T 5000.sup.1) 
80 
Jeffamine D 2000.sup.2) 
20 
Tegostab B 4690.sup.3) 
1 
Texacat ZF 20.sup.4) 
0.1 
Carbon dioxide 2.7.sup.5) 
103.8 1.034 
+ After charging with 0.601 
CO.sub.2 to Density (42% 
Nucleation) 
Stream 2: 
Suprasec VM 25.sup.6) 
48 1.175 
Stream 3: 
Water 4 1.000 
______________________________________ 
.sup.1) Product of Texaco Chemical Company, polyoxypropylenetriamine, 
amine equivalent: 52 mVal/g 
.sup.2) Product of Texaco Chemical Company, polyoxypropylenediamine amine 
equivalent: 98 mVal/g 
.sup.3) Product of Th. Goldschmidt AG, Silicone 
.sup.4) Product of Texaco Chemical Company, 
Bis(2-dimethylaminoethyl-)ether 
.sup.5) At a nitrogen pressure of 5 bar, gaseous carbon dioxide is 
introduced until the volumetrically calculated amount has been taken up. 
.sup.6) ICI modified MDI 24.3 weight % NCO content. 
The streams 1, 2 and 3 are combined in the high-pressure mixing head as 
described and injected into a closed mold to produce a compacted foam 
body. 
Molar Ratio 
EQU NH.sub.2 :NCO=1:4.55; NCO (Excess): Water 1:2.05 
______________________________________ 
Test 3 
______________________________________ 
Components 
Temperature, .degree.C./Pressure (bar) 
Stream 1 40/150 
Stream 2 28/150 
Stream 3 20/90 
Outlet velocity at throttle 
12 m/s 
gap of mixing heat 
Mold temperature, .degree.C.: 
70 
Injection weight, g: 350 
Mold volume, ml: 7320 
Mold rise time, Sec.: 40 
Tack-free time, Sec.: 180 
Removal time, Sec.: 240 
Bulk density, kg/m.sup.3 : 
44 
after compression and cooling. 
______________________________________ 
The foam material produced in tests 1, 2 and 3 can be easily pressed out of 
the molds and result in a very fine-pore open-cell foam.

SPECIFIC DESCRIPTION 
The mixing head 1 shown in FIGS. 1 and 2 comprises a cylindrical mixing 
chamber 2 into which three distinct component feed passages 3, 4 and 5 
open so that the passages 3 and 4 include an angle of 90.degree. between 
them and the passages 4 and 5 include an angle of 90.degree. between them. 
The feed passages 3, 4 and 5 serve to feed respectively the components A, 
B and C as above defined to the mixing chamber. 
The inlet orifices 6, 7 and 8 are controlled with absolute time 
synchronization by a single reversible axially-shiftable mixing chamber 
piston 9 which can simultaneously close off all of the orifices 6-8 or 
open all of the orifices. 
The mixing chamber piston 9 is actuatable by a hydraulic piston 10 and in 
the illustrated position in FIG. 1 is in its mixing position in which the 
inlet orifices 6, 7 and 8 are unblocked or freely open and the reactants 
contained in the components A, B and C at high pressure can intimately 
flow into the mixing chamber and intimately mix therein. In the blocked 
phase, with the piston 9 advanced to the right, the end face 11 of the 
piston 9 can lie flush with the outlet opening 12 of the mixing chamber 2 
to close the latter and expel any residues from the mixing chamber. 
In the mixing phase shown in FIG. 1, however, the reactive mixture from the 
components A-C flow at high velocity through the outlet opening 12 into a 
calming chamber 13 disposed at a right angle to the mixing chamber 2 and 
of a larger flow cross section. In the calming chamber, a further piston 
14 is reversibly axially displaceable and can abut a positioning screw 16 
which sets the width of a throttle gap 15 through which the reaction 
mixture is forced in the manner described into the mold cavity or chamber 
17. The piston 14, moreover, is provided with a hydraulic actuating piston 
17 in a cylinder 18 so that, at the end of the discharge of the reacting 
mixture into the mold cavity, and after the piston 9 has closed the 
orifices 6-8 and is advancing to the mouth 12, the piston 14 can drive any 
residue of the reaction mixture out of the calming chamber 13. Ultimately, 
the end 19 of the piston 14 will lie flush with the mouth 20 of the 
calming chamber 13. 
In FIG. 3, we have shown an embodiment in which the mixing chamber 22 of 
the mixing head 21 opens into the mold cavity 37 via a throttle orifice 35 
corresponding to the throttle gap 15 previously mentioned but provided in 
a feed channel of the mold 40 communicating between the mixing chamber 22 
and the cavity 37. As described in connection with FIGS. 1 and 2, separate 
feed passages 23, 24 and 25 can be provided for the components A, B and C, 
respectively, at right angles to one another so that the outlet orifices 
of these passages can be simultaneously blocked and unblocked by the 
mixing chamber piston 29. 
The apparatus of FIG. 3 operates similarly to that of FIGS. 1 and 2 except 
that the reacting mixture from the mixing chamber 22 passes through the 
flow channels of the mold into the mold cavity rather than into a calming 
chamber before entering the mold. The examples previously given are 
appropriate to this embodiment of the mixing head as well.