Note: Descriptions are shown in the official language in which they were submitted.
Mo-1~22-G
`~ LeA 16,340
.
la6ss40
A PROCESS FOR THE PRODUCTION
OF STABLE DISPERSIONS
.
Backaround of the Invention
.
Stable dispersions of polyaddition products of
diisocyanates and bifunctional primary or secondary amines,
hydrazines or hydra2ides in polypropylene glycol ethers are
generally ~nown. Dispersions of this type may be prepared
~y initially introducing the amine component in solution in
the polyether and adding the diisocyanate dropwise at room
temperature (see, e.g. German Auslegeschrift l,260,142).
However, even very small quantities of the polyaddition pro-
` duct (from 2 to 5%) are sufficient to produce a considerable
` increase in viscosity.
-` Polyurethane foams with improved mechanical prop-
erties (more especially increased tensile strength and hard-
;` ness) may be produced from dispersions of the type in question "
~- by reaction with polyisocyanates. However, dispersions with
a ~esinous solids content of approximately 10% by weight have
to be used in order to obtain distinct improvements in the
~;j 20 property spectrum which compiy with the requirements of the
motor vehicle and upholstery industries.Unfortunately, dispersions
with a solids content as high as this,produced by the proc~ss
described in German Auslegeschrift 1,260,142 (US-P~ 3,325,421),
... . .
~ may only be commercially processed into polyurethane foams
,~ 25 in low-pressure machines on account of their high viscosity.
x~ However, most foam manufacturers use high-pressure machines
:r~ in which the starting materials must have viscosities of
less than 2500 cP at 25C. The dispersions produced in accord-
ance with German Auslegeschrift 1,260,142 are not suitable
for foaming in high-pressure machines because of their high
,j .
~ I.eA 16,340
~.o6884
viscosities. Thus, for example, the reaction of tolylene
diisocyanate with hydrazine in a standard commercial-grade
soft foam polyether to form a 10% dispersion in accordance
with German Auslegeschrift 1,260,142 gives a product with a
viscosity of moxe than 10,000 cP/25C.
~ccordingly, an object of the present invention is
to provide non-sedimenting dispersions o~ polyureas and
polyhydrazo~dicarbonamides or corresponding mixed polyaddi-
tion products in polyethers containing hydroxyl- groups with
viscosities of less than 2500 cP/25C at a resinous solids
; content of approximately 10% ~y weight.
Description of the Invention
It has now surprisingly bèen found that dispersions
of this type with the low viscosities required may be obtained
by carrying out the polyaddition reaction in the presence of
the polyether in a continuous high-performance flow mixer.
Accordingly, the present invention relates to a
process for the _ situ production of stable dispèrslons-of
~ . -polyureas and/or polyhydrazo-dicarbonamides in polyethers
.- 20 containing hydroxyl groups by reacting: .
~ (1) organic polyisocyanates, with
:~ (2) polyamines containing primary and/or secondary amino
- ` groups and/or hydrazines and/or hydrazides, in
` ~ (3) relatively `h~gh` molecular weight polyethers containing
- 25 at least one hydroxyl group;
. wherein components (1), (2) and (3) are continuously
introduced into a flow mixer in such a quantity that
the average residence time in the mixer is le,ss than
LeA 16,340 -2-
'1~688~0
10 minutes, the equivalent ratio between components (1)
and (2) being from 0.8:1 to l.OS:l, and the reaction
product issuing from the flow mixer is subsequently
collected in a receiver. The three components may be
separately introduced into the flow mixer. Alterna-
tively, component (1) may be introduced separately from
a mixture of components (2) and (3). I~ desired, the
receiver is heated. When so heated, the temperature
is preferably maintained between 50 and 150C. Addi-
tionally, if desired, the product may be stirred while
in the receiver to complete the reaction if necessary.
:'
The instant invention also relates to stable dis-
persions produced according to the above-outlined process.
.~ . . , ' , ' .
In one particular embodiment of the process accord-
lS ing to the invention, monoisocyanates and/or primary or ~ ~-
secondary monoamines and/or monohydrazides may also be used
... .
in certain proportions in order to achieve selected molecu-
lar weights. Alkanolamines may also be added during the
polyaddition reaction for this purpose. In this way, reac-
; 20 tive groups are additionally introduced into the polyurea orpolyhydrazodicarbonamide particles.
In addition, it is often desirable to use certain
proportions of emulsifying sùbstances which stabilize the
dispersion, such as mono- or bi-functional polyethers con-
taining amino, semicarbazide or isocyanate groups.
.
Dispersions containing from 1 to 35% by weight of
polyureas and/or polyhydrazodicarbonamides (i.e., resinous
~ solids content) are preferred. Dispe~sions with a viscosity
j of less than 2500 cP/25C for a solids content of approximately
LeA 16,340 -3-
, ~;J ,.
. . .
1068840
10~ by weight are particularly preferred.
Although, in the reaction of polyisocyanates with
polyamines in the presence of polyethers containing hydroxyl
groups, the NCO-groups react preferentially with the NH2-
groups, the OH-groups also play their part in the reaction.
This reaction result~ in the formation of polyurea and/or
polyhydrazo dicarbonamide chains which are chemically attached
to polyether molecules. Molecules of this type presumably
have a dispersing effect upon the resinous particles. The
èxtent to which the OH-groups take part in the polyaddition
reàction is ~overned by the course of the reaction. If too
many polyether molecules react with the polyisocyanates,
` highly viscous dispersions are obtained. This is obviously
the case with the procedure described in German Auslegeschrift
1,260,142. If, on the other hand, the proportion of co-
reacting polyether molecules is too small, the dispersions
formed are in danger of being unstable. By following the
process of the instant invention, it is surprisingly possible
to control the NCO/OH-reaction to such a degree that finely
divided dispersions with the low viscosity required are
; formed. Additionally, the dispersions are still so stable
that they do not sediment even after prolonged storage and
even after storage at elevated temperatures.
Tn cases where low-viscosity polyethers containing
only secondary OH-groups or where substantially non-reactive
(aliphatic) isocyanates are used, the proportion of co-
reacting polyether molecules may be too small to form a
stable dispersion. In this case, it is best to include in
the polyaddition reaction substances which have an emulsifying
effect and, hence, increase the stability of the dispersion.
LeA 16,340 -4-
, ,
'; ,~ .
1068840
Substances of this type are linear polyethers having an
average molecular weight of from 300 to 4000 which contain
NCO-groups or amino or hydrazide groups at one or both ends
of the chain. It is preferred to use polyethers of the
type which contain one of the above-mentioned reactive groups
at only one end of the chain. Thus, the dispersions of the
instant invention ~preferably those having a solids content
of from 10 to 20% by weight) are generally added to the
, dispersion stabilizing polyethers of up to 5% by weight and
preferably in a quantity of up to 3~ by weight,' (based on
the total`quantity of polyether and resinous solids). In
the case of dispersions with a higher or lower solids con-
tent, the dispersion aid is u`sed in a correspondingly~ larger
or smaller quantity.
Modified polyethers with a di,spersing effect which '
may optionally be used in accordance with the invention in-
clude the addition products of excess diisocyanates andjor
polyisocyanates of the type mentioned below with monofunc-
tional and/or bifunctîonal hydroxyl polyethers having average
molecular weights of from 300 to 4000 which may optionally
have been freed from unreacted free isocyanate by thin-
,layer di,stillation. However, isocyanate prepolymers of thi$
type may also be reacted with the excess free isocyanate to
form allophanate isocyanates. It is also possible to con-
vert the addition products containing terminal isocyanate
gro,ups by reaction with excess diamines or hydrazine i,nto
polyethers containing terminal amino or semicarbazide groups
such as described in German Auslegeschrift 1,122,254 and
, 1,138,200~
,, ~: ., : '
Polyethers containing terminal amino groups, of the
LeA 16,340 -5-
1068840
type which may he obtained by the processes described in U.S.
Patent 3,155,~7~ or in German Auslegeschrift 1,215,373, may
also be used as dispersants in accordance with the inven-
tion.
Finally, hydroxyl polyethers may also be converted
by reaotion with phosgene into the chloroformic acid esters
which may be subsequently reacted with excess diamine or
hydra2ine. As mentioned above, it is preferred to use poly-
ethers of the type which contain an NCO- or NH2-group at only
'0 one end of the chain.
.. . .
The particle size of the dispersed polyaddition
products is also of'critical significance to the improvements
in properties which the final products herein bring about in
the polyurethane plastics produced from them. For example,
in cases where polyether dispersions are used as starting
materials for th-e production of polyurethane foams, the,dia-
meter of the filler particles must be considerably below the
- cell web dimensions (from 20 to 50 ~). In polyurethane
coatings, the particles also have to be so small that uni-
, form coatings with a smooth surface are obtained, even with
very thin applications. Dispe,rsions of particle size less
'than 1 ~'comply ideally with practical requirements and are
.. . . .
advantageously and,'easily formed by the process acco,ding
to the ins~ant invention.
;.' ' :
The polyethers useful in the instant invention
preferably contain from 1 to 8 and more preferably from 2 to
6 primary and/or secondary hydroxyl groups. The polyethers
preferably have molecular weights of from 200 to 16,000 and
, more preferably from 500 to 12,000. Polyethers of this type
LeA 16,~40 -6-
~068840
may be obtained in known manner by reacting startex compo~mds
containing reactive hydrogen atoms with alkylene oxides,
such as ethylene oxide, propylene oxide, butylene oxide,
styrene oxideF tetrahydrofuran or epichloxohydrin, or with
S mixtures of these alkylene oxides. In many cases, it is
preferred to use polyethers of the type which contain pre-
dominant amounts of primary OH-groups.
Suitable starter compounds containing reactive
hydro~en atoms include water, methanol, ethanol, ethylene
glycol, 1,2- or l,3-propylene glycol, 1,4- or 2`,3-butylene
glycol, 1,6-hexane diol, 1,8-octane diol, neopentyl glycol,
; . 1,4-bis-hydroxymethyl cyclohexane, 2-methyl-1,3-propane diol,
glycerol, trimethylolpropane, l,2,6-hexane triol, 1,2,4- -`
butane triol, trimethylolethane; pentaerythritol, ma~nitol,
sor~itol, methylglycoside, cane sugar, phenol, isononylphenol,
- resorcinol, hydroquinone, 1,2,2- and l,i,3-tris-(hydroxy-
phenyl)-ethane, ammonia, methylamine,` ethylene diamine,
tetra- or hqxa-methylene diamine, diethylene triamine, ethanol-
~ amine, diethanolamine, triethanolamine, aniline, phenylene
diamine, 2,4- and 2,6-diaminotoluene and polyphenyl-poly-
methylene-polyamines of the type obtained by condensing aniline
with formaldehyde. In addition, resin-like materials of the
' phenol and resol type may also be used as starters.
Suitable polyamines useful in the instant invention `
include: divalent and/or higher pol~valent, primary and/or
secondary, aliphatic, araliphatic, cycloaliphatic or aromatic
amines. Specific examples include ethylene diamine, 1,2-
and 1,3-propylene diamine, tetramethylene diamine, hexa-
methylene diamine~ dodecamethylene diamine, trimethyl diamino-
hexane, N,N'-dimethyl ethylene diamine, 2,2' bis-aminopropyl
~eA 16,340 -7~
. I;' .
_ _ _ _
~068840
methylamine, higher homologues of ethyl diamine, such as
diethylene triamine, triethylene tetramine and tetraethylene
pentamine, homologues of propylene diamine, such as dipro-
pylene triamine, piperazine, N,N'~bis-aminoethylpiperazine,
triazine, 4-aminobenzylamine, 4-aminophenylethylamine, 1-
amino-3,3,5-trimethyl-5-aminomethyl cyclohexane, 4,4'-diamino-
dicyclohexylmethane and propane, 1,4-diaminocyclohexane,
phenylene diamines, naphthylene diamines, condensates of
aniline and formaldehyde, tolylene diamines, bis-aminomethyl
benzenes and the derivatives of the above-mentioned aromatic
amines monoalkylated on one or both nitrogen atoms. The
polyamines useable will generally have molecular weights of
from about 60 to about 10,000, and preferably from 60 to
- 3000 with the molecular weight range of from 60 to 1000
being particularly preferred.
:
Suitable hydrazines include hydrazlne itself and
mono- or N,N'-disubstituted hydrazines, the substituents
being, e.g. Cl-C6-alkyl groups, cyclohexyl groups or phenyl
groups. The hydrazines generally have a molecular weight
of from 32 to 500. It is generally preferred to use hydrazine
itself.
Suitable hydrazines and hydrazides useful in accord-
ance with the instant invention include hydrazine, methyl
hydrazine, ethyl hydrazine, hydrazine hydrate, propyl hydrazine,
2~ isopropyl hydrazine, n-butyl hydrazine, isobutyl hydrazine,
tert.-butyl hydrazine, butenyl hydrazine, dodecyl hydraæine,
phenyl hydrazine, tolyl hydrazine, chlorophenyl hydrazine,
nitrophenyl hydrazine, benzyl hydrazine, 2-phenylethyl hydra-
zine, cyclohexyl hydrazine, cyclopentyl hydrazine, B-cYano-
ethyl hydrazine, 1,2-dimethyl hydrazine, 1,2-diethyl hydrazine,
LeA 16,340 -8-
~068840
diisobut~l hydrazine, l-butyl-2-methyl hydrazine, hydra-
zobenzene, l-benzyl-2-phenyl hydxazine, oxallyl dihydrazide,
semicarbazide, carbohydrazide, 4-methyl semicarbaæide, 4-
phenyl semicarbaz`ide, isophthalic acid dihydrazide, ~-hydrazino-
propionic acid hydrazide, thiosemicarbazide, thiocarbohydrazide,
aminoguanidine, l-amino-piperazine and 1,4-diaminopiperazine.
The hydrazides useable are generally the hydrazides
of divalent or higher polyvalent carboxylic acids, such as
carbonic acid, oxalic acid, malonic acid, succinic acid,
adipic acid, sebacic acid, azelaic acid, maleic acid, fumaric
acid, phthalic acid, isophthalic acid, and terephthalic acid;
; the esters of hydrazinomonocarboxylic acid with dihydric or
higher polyhydric alcohols and phenols, such as ethane diol,
1,2-propane diol, 1,2-butane diol, 1,3-butane diol and 1,4-
butane diol, hexa~e diol, diethylene glycol, triethylene
glycol, tetraethylene glycol, dipropylene glycol, tripropyl-
ene glycol and hydroquinone; and the amides of hydrazinomono-
carboxylic acid (semicarbazides) with, for example, the above-
mentioned diamines and polyamines. The hydrazides generally
have molecular weights of from 90 to 10,000, preferably from
. . .
90 to 3000 and, with particular preference, from 90 to 1000.
The`above-mentioned amines and hydrazines are op-
? tionally used in the form of their standard commercial-grade
- aqueous solutions.
n 25 Isocyani~te`s suitable for use in accordance with the
-~ invention include aliphatic, cycloaliphatic, araliphatic,
,
aromatic and heterocyclic polyisocyanates of the type described,
for example, by W. Sief~en in Justus Liebigs Annalen der ~-
. .
Chemie, 562, pages 75 to 136. Specific examples include
~eA 16,340 -9
.~
.. ~" .
.
~068840
ethylene diisoc~anate; 1,4-tetramethylene diisocyanate; 1,6-
hexamethylene diisocyanate; 1,12-dodecane diisocyanate; cyclo-
; . butane-1,3i-diisocyanate; cyclohexane-1,3- and 1,4-diisocyanate,
and mixtures of these isomers; l-isocyanate-3,3,5-trimethyl-
5-isocyanato methyl cyclohexane (see, e.g. German Auslegeschri.ft
1,202,785 and U.S. Patent 3,401,190); 2,4- and 2,6-hexahydro-
tolylene diisocyanate and mixtures of these isomers; hexahydro-
1,3- and/or 1,4-phenylene diisocyanate; perhydro-2,4'- and/or
4,4'-diphenyl methane diisocyanate; 1,3- and 1,4-phenylene
~0 diisocyanate; 2,4- and 2,6-tolylene diisocyanate and mixtures
of these isomers; diphenyl methane-2,4'- and/or -4,4'-diisocya-
nate; naphthylene-1,5-diisocyanate; triphenyl methane-4,4',4"-
triisocyanate; polyphenyl polymethylene polyisocyanates of
the type which may be obtained by condensing aniline with
` 15 formaldehyde, followed by phosgenation, and which are described,
for example, in British Patents 878,430 and 848,671; m- and
.~ ~-isocyanatophenyl sulphonyl isocyanates of the type described
in U.S. Patent 3,454,606; perchlorinated aryl polyisocyanates
of the type describea, for example, in U.S. Patent 3,277,138;
polyisocyanates containing carbodiimide groups of the type
described in U.S. Patent 3,152,162; diisiocyanates of the type
described in U.S. Patent 3,492,330; po~yisocyanates containing
allophanate groups of the type described, for example, in
British Patent 994,890, Belgian Patent 761,626 and published
Dutch Patent Application 7,102,524; polyisocyanates containing
isocyanurate groups of the type described, for example, in
U.S. Patent 3,001,973, in German Patents 1,022,789; 1,222,067
and 1,.027,394, and in German Offenlegungsschriften 1,929,034
and 2,004,048; polyisocyanates containing urethane groups
30 of the type described, for example, in Belgian Patent 752,261
or in U.S. Patent 3,394,164; polyisocyanates containing
LeA 16,340 -10-
,~ ........ , . ; .
- S~
~068840
acylated urea groups of the type described in German Patent
1,230,778; polyisocyanates containing biuret groups of the type
described, for example, in German Patent 1,101,394, U.S.
Patents 3,124,605 and 3,201,372 and in British Patent 889,050;
S polyisocyanates obtained by telomerization reactions of
the type described, for example, in U.S. Patent 3,654,106;
polyisocyanates containing ester groups of the type described,
for example, in ~ritish Patents 965,474 and 1,072,956, in
U.S. Patent 3,567,763 and in German Patent 1,231,688; reac-
tion products of the above-mentioned isocyanates with acetals
. . as described in German Patent 1,072,385; and polyisocyanates
:~` containing polymeric fatty acid radicals of the type described
~ in U.S. Patent 3,455,883.
' `.: . , . .': -
: It is also possible to usè~~the isocyanate-group-
,
containing distillation residues accumulating in the production
`. of isocyanates on a commercial scale, optionally in ~olution
~ in one or more of the aforementioned polyisocyanates. It is
. also possible to use mixtures of the aforementioned polyiso- .
cyanates. ~.,. . - - . . . .
. 20 In general,-it is; particularly preferred to use .- .
readily available polyisocyanates, such as 2,4- and 2,6-
tolylene diisocyanates and mixtures of these isomers ("TDI"); -
`. polyphenyl polymethylene polyisocyanates of the type obtained .~ by condensing aniline with formaldehyde, followed by phos-
.. 25 genation (ncrude MDI"); and, polyisocyanates containing car- :
. bodiimide groups, urethane groups, allophanate groups, iso-
~ .
cyanurate groups, urea groups or biuret groups ("modified
. polyisocyanates").
The process according to the invention also enables
isocyanates and amines, hydrazines or hydrazides with a
Le~ 16,340 -11-
, ~ .
.~ . . _ ~. . ,
,
1068840
functionality of more than two to be proportionately or
exclusively used. It is surprising that the reaction of
compounds of such relatively high functionality in polyethers
containing hydroxyl groups does not result in the formation
of soli~ or at the least, very highly viscous reaction prod-
ucts. Rather the reaction results once again in the forma-
tion of finely divided, low-viscosity dispersions.
The polyaddition products obtained by the process
according to the invention, dispersed in polyethers containing
hydroxyl groups, may also be modified by the proportionate
use of monofunctionàl isocyanates, amines, hydràzine deriva-
tives or ammonia. For example, the average molecular weight
of the polyaddition products may be adjusted by incorporating
monofunctional compounds of this type. In cases where aikan-
olamines with primary or secondary amino groups are used,
- it is possible to synthesize polyureas and polyurea poly- -
hydrazo-dicarbonamides containing free hydroxyl groups. It
is also possibie to introduce other groups, such as ester r
groups, relatively long aliphatic radicals, tertiary amino
groups, and active double bonds, by utiiizing correspondingly
substituted monoamines or diamines and/or isocyanates.
According to the invention, the monofunctional
`~ compounds may generally be used in proportions o~ up to 40 mol
% and more preferably in proportions of up to 25 mol % (based
~` 25 on total isocyanate" amine, hydrazine and hydrazide content).
Suitable monofunctional isocyanates include: alkyl
. . .
isocyanates, such as methyl, ethyl, isopropyll isob~tyl,
hexyl, lauryl and stearyl isocyanate; chlorohexyl isocyanate;
cyclohexyl isocyanate; phenyl isocyanate; tolyl isocyanate,
4-chlorophenyl isocyanate, and diisopropyl phenyl isocyanate.
LeA 16,340 -12-
~.j ~ ' ' .. '
. . . . . .
., .. .. - . ~
. . : . . : . . .
1068840
Examples of suitable monoamines include alkyl and
- dialXyl amines with Cl-C18 alkyl groups: cycloaliphatic amines,
such as cyclohexyl amine and homologues thereof; aniline and
N~alkyl anilines; aniline derivatives substituted on the f
benzene nucleus; alkanolamines, such as ethanolamine, di-
ethanolamine, propanolamine, dipropanolamine, butanolamine
`~ and dibutanolamine; diamines with one tertiary and one pri-
` mary or secondary amino group, such as N,N-dimethyl ethylene
diamine and N-methyl piperazine. Suitable monofunctional
hydrazine derivatives and hydrazides include: N,N-dialkyl
. . . j .
hydrazines, the hydrazides of monocarboxylic acids, hydrazine
monocarboxylic acid esters of monofunctional alcohols or
phenols, and semicarbazides, such as methyl, ethyl, propyl~
butyl, hexyl, dodecyl, stearyl, phenyl and cyclohexyl semi-
c~rbazide.
The molecular weight of the polyaddition products
formed in dispersion in polyethers is determined by the
quantitative ratio between the polyamine, hydrazine or
hydrazide on the one hand and the polyisocyanate on the other
~ 20 hand (and by the monofunctional compounds used, if any). It
is particularly prefèrred to react substantially equivalent
quantities of isocyanates and NH-functional compounds in
the polyether containing hydroxyl groups. However, it is
3~ also possible to use a small excess of isocyanate (approxi-
mately 5~), although in this case products of higher viscosity
~ are obtained because the excess of polyisocyanate reacts with
`~ the polyether. In the case of the amine, hydrazine or hydra-
side, it is possible to use a larger excess, in which case
polyaddition products with reactive terminal groups and a
30 limited molecular weight are obtained. In general, an NCO:NH
; LeA 16,340 -13-
~ , .
. ~ ' ' ~.
"~ , -~, ,.. . . : , .... . . . .
~C~68840
ratio of from 0~80 to 1.05, more preferably from 0.90 to 1.02,
is maintained. - -
The concentration of the polyaddition products inthe polyether containing hydroxyl groups may vary within wide
limits, althou~h it is generally from 1 to 35% by weight~more
preferably from 3 to 30~ by weight. The quantity of dispersed
polyaddition product required for foams with optimal prop-
er~ies is generally about 10% by weight. It is readily
possible in accordance with the instant invention to produce
~10 10% by weight dispersions, of this type. For economic reasons,
however, it is preferred to prepare a dispersion with as
; large a content of polyaddition products as possible (in
general from 20 to 30% by weight) and to then dilute this
~ . . .
dispersion with a polyether to the required concentration.
This highly economic procedure represents yet another advan-
tage of the process according to the invention over the pro~
cess described in German Auslegeschrift 1,260,142.
In general, the reaction components are introduced ' -
into a flow mixer of the type generally known in the art a~
.. . , ~ .
room temperature.~ The reaction temperatures may rise to from
50 to l50~C under the effect of the shear `forces generated in
... . .
~ cases where a dynamic mixer is used and under the effect of
`~ the heat of the polyaddition reaction generated depending
upon the quantity of resinous solids. In general, however,
it~is best to keep the temperature below 110C (optionally by
`r . cooling the mixer), because otherwise any water which may
be present evaporates and can give ri`se to disturbances as
a result of bubble formation. In cases where hydrazine is
used, it is important to ensure that the decomposition
temperature of hydrazine is not exceeded.
LeA 16,340 -19-
~ : , . , . : -
1~6~3840
An important feature of this process is that the
polyaddition reaction of polyisocyanates and polyamines,
hydrazines or hydrazides is carr,ied out in high-performance
continuous flow mixers with average residence times of less
than 10 minutes and preferably less than 3 minutes.
The homogenization or dispersion time ~, should only
amount to at most 10~ of the average residence time, T, in
order to obtain thorough admixture of the components. Accord-
ing to the invention, it is possible, although not essential,
to arrange two or even more flow mixers one behind the other.
The times quoted above then apply logically to the mixer system
as a whole.
Flow mixers are known and divided into two groups,
;~ namely static mixers with fixed fittings, and dynamic mixers
with movable fittings operating on the rotor-stator principle.
~; They may optionally be heated or cooled. In the case of static
mixers, the mixing energy required is applied through pumps,
whereas in the case of dynamic mixers a separate motor drives
the rotor.
In every case, the dispersing effect and, hence, the
particle size in the dispersion is governed by the energy
applied and the shear forces correspondingly generated.
!j' Static mixers may be divided into the following
groups:
(a) Mixers with simple fittings. (see e.g. US-P 3,286,992, German
Offenlegungsschrift 2,119,239 and US-P 3,704,006).
. (b) Multi-channel mixers (for example, the AMK-Ross-ISG* Mixers
j manufactured by Aachener Misch-und Knetmaschinen-Fabrik,
'~ West Germany).
`, * Trademark
LeA 16,340 -Ca. ~ -15
.
1068840
(c) So-called packing mixers, for example, the static mixers
manufactured by Sulzer AG (Winterthur, Switzerland) and
the BKM*-Mixers manufactured by Bayer AG (West Germany).
~' .
.
. ,i .
.'~
.~ .
, .
.~ ,~,, .
.
. ~ .
~, ..
,:~
* Trademark
LeA 16,340-Ca. -15a-
"' ~A,'
1~681340
(See, e.g. U.S.-P 3,785,620 and German Offenlegungs-
schrift 2,238,795 corresponding to US-SN. 474,836,
respectively).
` (d) Further variants of static mixers are mixing nozzles,
for example, those manufactured by the Lechler Company
(Stuttgart, West Germany) or the mixing chambers in the
HK*-machines manufactured by the Hennecke Company
`~ (Birlinghofen, West Germany) into which the starting
products are injected under high pressure (countercurrent
injection).
" Dynamic mixers suitable for use in the process
according to the invention include the ~low mixers manufactured
by the companies Ekato RMT (Schopfheim, West Germany), Lightnin
(Neu-Isenburg, West Germany) and Hennecke (toothed stirrer)
~i 15 which, like the known impeller-type homogenizing machines
y operate on the stator-rotor principle, but cannot be used to
perform fieed or delivery functions. The energy required for
dispersion in general amounts to from 1 to more than 10 kW
per liter of mixer volume, depending upon the required particle
;~ 2Q size, the type of mixer used and the viscosity of the starting
materials.
.
In cases where anhydrous amines, hydrazines and
i hydrazides are used, there is no need for any further working-
up on completion of the polyaddition reaction. However, in
cases where aqueous amines (for example, aqueous ethylene
diamine solution or hydrazine hydrate) are used, it is aduisable
in some cases to remove the water from the dispersion in vacuo.
~ In general, the process according to the invention
i * Trademark
' LeA 16,340-Ca. -16-
,
1068840
is carried out by introducing the three components (polye~her,
NH-component and polyisocyanate) from separate supply vessels
through metering pumps into the flow mixer in which they are
thoroughly mixed and in which, at the same time, most of the
polyaddition reaction takes place. However, it is also possi-
ble to combine the amine component with the polyether com-
ponent before introduction into the flow mixer. ~he sllb-
stantially reacted product is then introduced into a receiver
in which it is optionally stirred to complete the reaction,
optionally with heating to from 50 to 150C. In cases where
aqueous amines are used, the end products are, if desired,
freed in vacuo from the water present in them.
Additives, such as activators, stabilizers, water,
blowing agents, flameproofing agents and pigment pastes, may
1~ be added to the dispersions prepared by the process according
to the invention either during or after the reaction.
., , , . . ..
The dispersions prepared by the process according to
the invention may be processed, for example, into soft, sem.i~
hard and hard polyurethane foams with improved properties,
such as increased tensile strength and hardness. In addition!, L ~ ` `
foams of the polyhydrazodicarbonamide dispersions are distin~
guished by increased whiteness. The dispersions are also
suitable for the production of, for example, elastomers, ¦~
coverings and coatings based on polyurethanes. -
The process according to the invention is illustrated
by the following Examples. Unless otherwise indicated, parts
are parts by weight and percentages percent by weight. ~-
~ he abbreviations used in the Examples for the poly-
ethers have the following meanings:
LeA 16,340
:. .
10~8840
Polyether (A,. ~ trimeth~lol propane-started polyether of
propylene oxide and ethylene oxide with an
OH number of 34 and a primary OH-group con-
tent of approximately 80% based on the total
OH content of the polyether.
Polyether (B): Same as Polyether (A), but with an OH number
of 35 and a primary OH-group content of
approximately 70% based on the total OH con-
tent of the polyether.
`- ` . ` I
Polye~her ~C): A glycerol-started polyether of propylene
oxide and ethylene oxide with an OH number of
56 and a primary OH-group content of approxi- '~
mately 50~ based on the total OH content of ~ `
the polyether. ¦
Polyether (D): Same as Polyether (A), but with an OH number s
of 28 and a primary OH-group content of approx- ~ -
~' imately 80~ based on the total OH content of
the polyether. ;~
Polyether (E): A trimethylol propane-started polyether of
propylene oxide and ethylene oxide with an O~
~ ~ I
number of 49 and containing essentially
only secondarY OH gFoups.
Polyether (F): A linear polypropylene glycol (OH number 56)
Polyether (G): A linear polypropylene glycol terminally ,~
modified with ethylene oxide (OH number 28;
approximately 80% by weight of the OH groups
, are primary OH-groups).
- LeA 16,340 -18~
t
106884Q
Pol~ether (H): A trimethylol propane-started polyethylene
oxide (OH number 550).
EX~MPLE 1
-- .
800 g/minute of Polyether (D), 169 g/minute of a
S mixture of 80% of 2,4- and 20% of 2,6-tolylene diisocyanate
and 49 g/minute of hydrazine hydrate are continuously intro-
duced at room temperature into two toothed stirrers arranged
one behind the other (chamber volumes 1.5 liter and 0.5 liter,
respectively; rotational speed 1500 rpm). The three com-
.
ponents are directly introduced separately from one another
into the mixing zone of the first toothed stirrer. The poly-
ether is delivered from the supply vessel through a gear pump,
while the two thinly liquid components are introduced from
separate supply vessels through piston-type metering pumps.
The highly exothermic polyaddition reaction takes place in
the toothed stirrers. The reaction temperature is adjusted
to from 100 to 105C by cooling the toothed stirrers. After
a residence time of approximately 2 minutes, an almost com-
pletely reacted white dispersion leaves the second toothed
~, .
` 20 stirrer. The dispersion is transferred to a dwell vessel
where it is stirred at from 8p to 100C. After stirring,
. . . ..
the water emanating from the hydrazine hydrate is distilled ~-
off in vacuo àt 100C. A stable, white, finely divided
dispersion having a solids content of 20~, with an OH number
~25 of 22;5, a visco~ity of 3700 cP/25C and a pH-value of 8.3
is obtained. ~ -
~' After dilution with Polyether (D) to a polyhydrazo-
dicarbonamide content of 10~ by weight the visco~ity amounts
to 1900 cP/25C (OH number: 25.2).
~eA 16,340 -19-
.
. ~ .
. . , . , ~ ,
106~8~0
:
Comparison Example la (According to German Auslegeschrift
.
1,260,142)
Following the addition of 1.225 kg of hydrazine hy-
drate, 4.225 kg of a mixture of 80% of 2,4- and 20% of 2,6-
tolylene diisocyanate are run with intensive stirring over a
period of 30 minutes at room temperature into 45 kg of Poly-
ether (D). The temperature rises to 55C, accompanied by
precipitation of the polyhydrazodicarbonamide. After stirring
for 1 hour, the water emanating from the hydrazine hydrate is
removed in vacuo at 100C- A white dispersion having a solids
content of }0%, with an OH number of 25.2, a viscosity of
19,000 cP/25C and a pH-value of 8.3 is obtained.
., '
EXAMPLE 2
.~ -- ` . ~ .
The procedure is as in Example 1. 800 g/minute of
Polyether (A), 169 g/minute of a mixture of 80% of 2,4- and
20% of 2,6-tolylene diisocyanate and 49 g/minute of hydrazine
` hydrate are continuously introduced into the first toothed
stirrer.The total residence time amounts to about 2 minutes. ¦;
A stable, white, finely divided dispersion having a ,
~solids content of 20%, with an OH number of 27, a viscosity
of 3300 cP/25C and a pH-value of 8.2, is obtained following
removal of the water by dlstillation. ¦ ~
After dilution with Polyether (A) to a solids con- ~ -
tent of 10%, the ~iscosity amounts to 1600 cP/25C (OH
number 30.5).
` Comparison Example 2a (According to German Auslegeschrift
1,260,142) ; ~
., ., '. ~ .
The procedure is the same as in Comparison ~xample la.
LeA 16,340 -20-
, ~I ' .
. , . , . : , . : , ,, :. .
~-` 106884()
.~ kg of Polyether (A) and 1.225 kg of hydrazine hydrate are
initially introduced, and 4.225 kg of a mixture of 80% of
2,4- and 20% of 2,6-tolylene diisocyanate are added thereto
over a period of 30 minutes. A dispersion having a 10%
solids content, with an OH number r~f 30.5, a viscosity of
17,500 cP/25C and a pH--value of 8.2, is obtained after
stirring for 1 hour and removal of the watex by evaporation.
EXAMPLE 3
The procedure is as in Example 1, except that 1600
g/minute of Polyether (B), 338 g/minute of a mixture of 80%
of 2,4- and 20% of 2,6-tolylene diisocyanate and 98 g/minute
o~ hydrazine hydrate are introduced into the toothed stirrer. `
The total residence time in the stirrers amounts to approxi- :
mately 1 minute.
A stable, white, finely divided dispersion having a
solids content of.20%, an OH number of 28, a viscosity of 2900
cP/25C and a pH-value of 8.1, is obtained following removal .
of the water by distillation. . . ;:
After dilution with Polyether (B) to a solids con-
tent of 10~, the viscosity amounts to 1500 cP/25C (OH number:
31.5).
. EXA.~PLE 4
'
; T~e procedure is as in ~xample 1, except that 800
~ g/minute of Polyether (C), 169 g/minute of a mixture of ~0%
5. 25 of ~,4- and 20% of 2,6-tolylene diisocyanate and 49 g/minute
of hydrazine hydratè, are introduced into the two toothed stirrers.
.. In this Example, however, the total volume of the two.stirrers
. was only 100 ml and the residence time about 6 seconds. The tem-
. perature of the dispersion issuing from the mixer is maintained
at approximately 60C by cooling the ..~ .
LeA 16,340 -21- ^ -
.
1~68840
toothed stirrers.
A stable, white, finely divided dispersion having a
solids content of 20~, with an OH nu~ber of 45, a viscosity of
1400 cP/25C and a pH-value of 7.8A is obtained after working-
up.
EXAMPLE 5
The procedure is as in Example 1, except that 800
g/minute of Polyether (A), 148.8 g/minute of the mixture of
Example 4 of 2,4- and 2,6-tolylene diisocyanate and 67.4 g/
minute of a 76% aqueous ethylene diamine solution are intro~ t,.', ` "
duced into the two toothed stirrers. The total residence time
amounts to about 2 minutes.
Removal of the water by distillation leaves a
; stable, white, finely divided dispersion (solids content = 20%)
, 15 with an OH number of 27, a viscosity of 4600 cP/25C and a pH-
value of 10.1.
After dilution with Polyether (A) to a solids
content of 10~, the viscosity amounts to 1730 cP/25C.
EXAMPLE 6
,,
Dispersions with different polyhydrazodicarbonamide
' contents are prepared in a standard foaming machine (UFS*-
machine, a product of the Hennecke Company) with a maximum
' polyether input of 12 kg. The three starting components are
introduced into the mixing chamber of a stirrer (chamber
- 25 volume 159 ml, toothed stirrer: 35~0 rpm) through injection
nozzles by means of reciprocating pumps. After an average
residence time of approximately 2 seconds in the mixing
chamber of the stirrer, the dispersion is stirred for 30
* Trademark
LeA 16,340 -Ca. ~22-
.. . .. . . .
~068840
.~ .
minutes at 80C in a dwell vessel and subsequently freed from
' ~ter in vacuo.
~ .
(a) 5700 g/minute of Polyether (A), 253.5 g/minute of a
mixture of 80~ of 2,4- and 20% of 2,6-tolylene diiso-
S ~yanate and 73.5 g/minute of hydrazine hydrate are
introduced into the mixing chamber by means of the
three reciprocating pumps. A finely divided disper-
sion tsolids content = 5~) with an OH number of 32,
a viscosity o 1600 cP/25C and a pH-value of 7.7, is
~0 obtained after stirring and removal of the water by
distillation. ' ~ '
.
' (b) 5400 g/,minute of Polyether (A), 507 g/minute of the
tolylene diisocyanate mixture and 147 g/minute of
, hydrazine hydrate, are introduced into the mixing cham-
ber by the pumps. Workin~-up in the same way as in (a) '
gives a finely divid,ed dispersion (solids content =
` 10%) wi,th an O~ number of 30.5, a viscosity of 1900
' -, cP/25C and a p~-value of 8Ø
'. . , . ;
- (c) 5100 g/minute of Polyether (A), 760.5 g/minute of the
, 20 tolylene diisocyanate mixture and 220.5 g/minute of
~ hydrazine hydrate are introduced into the mixing cham- `
`~I ber. Working-up in the same way as in '(a) gives a finely
divided dispersion (solids content = 15%) with an OH
' number of 29, a viscosity of 2450 cP/25C and a pH-
value of 8.1. ,,
. . ,
(d) 4800 g/minute of Polyether (A~, 1014 g/minute of the
tolylene diisocyanate mixture and 294 g/minute of
hydrazine hydrate are introduced into the mixing cham- '
bex. Working-up in the same way as'in (a) gives a
~eA 16,340 -23-
~ - .
~ . ~ . ....
1068840
- finely divided, dispersion (solids content = 20~) with
an OH number of 27, a viscosity of 3600 cP/25C and a
~H~value of Q. 1.
EXAMPLE 7
400 g/minute of Polyether (G) and 49 g/minute of
hydrazine hydrate are synchronously introduced at room tem-
perature into a static mixer according to US-P 3,286,992
(diameter: 6.3 mm, length:
~ 29Q mm, number of elements: 24) for emulsification through
'~ 10 two of the heads of a four-head reciprocating pu~mp. while
400 g/minute of Polyether (G) and 169 g/minute of a mixture
~ of 803 by weight, of 2,4-"`and'2`0~ by weight, of 2,6-tolylene
`~ ~ diisocyanate are synchronously pumped by the other two heads
' throuyh a second, identical static mixer. The mixtures -
~5 leaving the two static mixers are then thoroughly mixed i'n
` a third static mixer (diameter: 6.3 mm, length: 152 mm,
`~;- number of elements: 12). Part of the polyaddition reaction
actually takes place in this static mixer, the mixture under- -
' going an increase in temperature to from 60 to 80C. The
dispersion flows from the mixer into a dwell ~essel, in
~ , . . .
which it is stirred for 30 minutes at from 80 to 100C to
' complete the reaction. The dispersion is then freed from
;' water in vacuo.
A stable, white, finely divided dispersion (solids '' ~'
content = 20%) with an OH number of 22.5, a viscosity of '~
2470 cP/25C and a pH-value of 8.1 is obtainedO After '
; ~ dilution with Polyether (G) to a filler content of 10% by
weight the viscosity amounts to 1250 cP/25C.
~'~ EXAMPLE 8 i~--
,
A mixture of 4000 g/minute of Polyether (H) and 245
; LeA 16,340 -24-
1068840
.
g/minute of hydrazine hydrate, which has been mixed in a
pxeceding toothed stirrer (chamber volume 0.5 liter), and
845 g/minute of a mixture of 80% of 2,4- and 20~ of 2,6-
toiylene diisocyanate, are continuously introduced at room
S temperature into a high-speed impeller-type homogenizer
(volume 0.15 liter, rotational speed 3800 rpm). Both com-
ponents directly enter the mixing zone of the homogenizer
separately rom one another. The mixture undergoes an
increase in temperature both under the effect of the incipi-
ent polyaddition reaction and under the effect of the
intense shear forces generated. The dispersion issuing from
the homogenizer at a temperature of approximately 90C is
transfer~ed to a dwell vessel in which it is stirred for
30 minutes at from 80 to 100C. Removal of the water by
distillation leaves a white, stable, finely divided disper~
sion (solids content = 20%) with an OH number of 495, a
~ viscosity of 3200 cP/25~ and a pH-value of 8.1. After di-
; lution with Polyether (H) to a solids content of 10~, the
; ~iscosity amounts to 1450 cP/25C.
~XAMPLE 9
` The procedure is as in Example 1, except that an
excess of hydrazine is used and that the en~ire quantity of
; hydra2ine hydrate is additionally emulsified beforehand in
the polyether.
An emulsion of 800 g/minute of Polyether (A) and
53.7 g/minute of hydrazine hydrate and 166 g/~inute of a
mixture of 80~ of 2,4- and 20~ of 2,6-tolylene diisocyanate,
are introduced into the two toothed stirrers.
LeA 16,340 -25-
.
~ , ' '.
1068840
Removal of the water by distillation leaves a stable,
white~ finel~ divided dispersion (solids content = 20%) with
a viscosity of 2880 cP/25C and a pH-value of 8.2. After
dilution with Polyether (A) to a solids content of 10%,
the viscosity amounts to 1450 cP/25C.
E.Y~MPLE 10
The procedure is as in Example 7. 400 g/minute of
Polyether ~C) and 57 g/minute of diethylene triamine are
pxemixed in one static mixer, while 40Q g/minute of Poly-
ether (C) and 143 g/minute of a mixture of 80% of 2,4- and
20~ of 2,6-tolylene diisocyanate are mixed in the other
static mixer. Both streams then enter the third mixer f~r
reaction. A stable, white, finely divided dispersion (solids
content = 20%) with an OH number of 45, a viscosity of 3250
cP/25C and a pH-value of 10, is obtained after stirring.
. - .
After dilution with Polyether (C) to a solids con-
tent of 10~, the viscosity amounts to 1300 cP/25C.
EXAMPLE 11
''`'~. ' .' ' , ' . " ~
The procedure is as in Example 1. 800 g/minute of
Polyether (A), 45.3 g/minute of hydrazine hydrate and 171 ~/
:. . , .:
minute of a mixture of 80~ of the above tolylene diisocyanate
mixture and 20~ of a polyphenyl-polymethylene-polyisocyanate,
obtained by phosgenating an aniline-formaldehyde condensate -
with an approximately 50% binuclear content, are introduced
into the two toothed stirrers.
A stable, finely divided dispersion (solids content =
20~) with an OH number of 27, a viscosity of 2900 cP/25C and
a pH-value of 7.5, is obtained.
¦ Le~ 16,340 -26-
.. - : . . . .
1068840
After dilution to a solids content of 10% with
Polyether (A), the viscosity amounts to 1450 cP/25C.
EXAMPLE 12
. .
The procedure is as in Example 7. 400 g/minute of
Polyether (A) and 53.5 g/minute of an amine mixture of hydra-
zine hydrate and ethanolamine ~molar ratio 9 : 2; calculated
molecular weight of the dispersed particles: 2150) are mixed
" in the first static mixer, while 400 g/minute of Polyether
~) and 162 g/minute of the above tolylene diisocyanate
mixture are mixed in the other static mixer. Both streams
.. , . . . ~
enter the third mixer for reaction. Removal of the water by
distill'ation leaves a stable, white, finely divided dispersion
' ~solids content = 20%) with an OH number of 37.6, a viscosity
: . .
~; of 2850 cP/25C and a p~-value of 9.5. '
~; .
'~ 15 After dilution with Polyether (A) to a solids con-
-`~ , tent of 10~ by weight thè viscosity amounts to 1500 c'P/25C.
-'` EXAMPLE 13
The procedure is as in Example 1, except that the
amine is previously dissolved in the polyether.
A solution of 97.7 g/minute of an aniline/formalde-
hyde condensate, consisting f ?% by weight of 4,4'-diamino
`~ diphenyl methane and 30% by weight of higher condensates, in
800 g of Polyether (E), and a mixture of 79.8 g/minute of ~ '
the above tolylene dii'socyanate with 22.5 g/minute of an
allophanate (11.5% NCO) of 6 mols ~f tolylene diisocyanate
and 1 mol of a polypropylene oxide with a terminal OH group
(molecular weight: 2600), are introduced into the two toothed
stirrers.
LeA 16,340 -27-
:: -
... ,, ..... _
, .
1068840
A stable, finely divided dispersion with an OH num-
ber of 39, a viscosity of 3500 cP/25C and a pH-value of 7.5
is obtained.
r
After dilution with Polyether (E) to a solids con-
tent of 10% by weight the viscosity amounts to 1450 cP/25C.
!`
EXAMPLE 14
The procedure is as in Example 1, except that the
amine is previously dissolved in the polyether. ~ -
A solution of 61.5 g/minute of hexamethylene diamine
and 20 g/minute of the reaction product of hydrazine and the
chlorocarbonic acid ester of a monofunctional polypropylene
` oxide (molecular weight: 2000) in 800 g/minute of Polyether
(F), and 117.5 g/minute of 1-isocyanàto-3,3,5-trimethyl-5-
-~ isocyanatomethyl cyclohexane, are introduced into the two
toothed stirrers.
A stable, white, finely divided dispersion (solids
.~,
content = 20~) with an OH number of 45, a viscosity of 2400 ~ : -~
` cP/25C and a pH-value of 10 is obtained. ¦
f ~
After dilution with Polyether (F) to a solids con-
tent of 10~ by weight, the viscosity amounts to 1200 cP/25C.
. EXAMPLE 15
The proçed~re is as in Example 7. 350 g/minute of
Polyether (F), 66 g/minute of hydrazine hydrate and 30 g/
minute of a linear polypropylene oxide with a terminal NH2-
125 group and a secondary OH-group (molecular weight: 2000) are
mixed in the first static mixer, while 350 g/minute of Poly- ¦ -
; ether (F) and 228 g/minute of the above tolylene diisocya-
LeA 16,340 -28-
.. .... . . ..
, .
. .
,. 1068840
nate mixture are mixed in the other static mixer. The two
mixtures then enter the third mixer for reaction. A stable,
white, finely divided dispersion (solids content = 30~) with
an OH number of 39, a viscosity of 2900 cP/25C and a pH-
vaLue of ~.1, is obtained after stirring and removal of thewater by distillation.
After dilution with Polyether (F) to a solids con-
tent of 10% by weight the viscosity amounts to 900 cP/25C.
It is to be understoodrthat any of the components
~ and conditions mentioned as suitabIe herein can be substituted
for its counterpart in the foregoing examples and that al-
though the invention has been described in considerable detail `
; in the foregoing, such dètail is solely for the purpose of
` illustration. Variations can be made in the invention by
; ~ .
those skille~ in the art without departing from the spirit and
15 : `scope of the invention except as it may be limited by the
` claims.
.
- :
~ .
. - .
. .
: - .
,, ;;,
; ' ' ' .
LeA t6,340 -29-
`
.` ` ' ` ' ' ` `~ `
