U.S. patent application number 10/218562 was filed with the patent office on 2002-12-19 for process for the preparation of aqueous emulsions of advantageously masked (poly) isocyanate oils and/or gums and/or resins and emulsions obtained.
Invention is credited to Derian, Paul-Joel, Langlois, Bruno, Senechal, Alain.
Application Number | 20020193508 10/218562 |
Document ID | / |
Family ID | 26230217 |
Filed Date | 2002-12-19 |
United States Patent
Application |
20020193508 |
Kind Code |
A1 |
Derian, Paul-Joel ; et
al. |
December 19, 2002 |
Process for the preparation of aqueous emulsions of advantageously
masked (poly) isocyanate oils and/or gums and/or resins and
emulsions obtained
Abstract
A method for preparing aqueous emulsions of oils, gums or
preferably masked (poly)isocyanate resins by kneading a mixture
consisting of (1) a preferably masked (poly)isocyanate phase (A)
with a viscosity of at least 3 Pa.s or a consistency of at least
200, and (2) an aqueous phase consisting of water, at least one
surfactant (B) and optionally at least one water-soluble thickening
polymer (C), the relative amounts water, (B) and optionally (C)
being such that said aqueous phase has a viscosity or consistency
preferably no lower than that of the preferably masked
(poly)isocyante phase (A), and said kneading being performed for a
sufficient time and with sufficient shear to give an oil-in-water
emulsion with a particle size of 0.1-5 .mu.m, and optionally by
diluting the medium with water.
Inventors: |
Derian, Paul-Joel;
(Fontenay-aux-Roses, FR) ; Langlois, Bruno;
(Sainte-Genevieve-des-Bois, FR) ; Senechal, Alain;
(Malson-Alfort, FR) |
Correspondence
Address: |
Norman H. Stepno
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Family ID: |
26230217 |
Appl. No.: |
10/218562 |
Filed: |
August 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10218562 |
Aug 15, 2002 |
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08530193 |
Mar 4, 1996 |
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08530193 |
Mar 4, 1996 |
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PCT/FR94/00353 |
Mar 30, 1994 |
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Current U.S.
Class: |
524/589 |
Current CPC
Class: |
C08G 18/8061 20130101;
C08G 18/706 20130101 |
Class at
Publication: |
524/589 |
International
Class: |
C08J 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 1993 |
FR |
93/03795 |
Mar 31, 1993 |
FR |
93/03796 |
Claims
1) Process for the preparation of aqueous emulsions of
(poly)isocyanate oils and/or gums and/or resins, characterized in
that a mixture consisting of the following is blended 100 parts by
weight of an advantageously masked (poly)isocyanate phase (A) of
dynamic viscosity at 25.degree. C. at least equal to 3 Pa s,
preferably at least equal to 30 Pa s. Or [sic] of consistency at
25.degree. C. at least equal to 200, advantageously masked
(poly)isocyanate phase including at least one oil and/or at least
one gum and/or at least one resin containing advantageously masked
(poly)isocyanate groups; 2 to 20 parts by weight, preferably from 3
to 15 parts by weight of water; 3 to 20 parts by weight, preferably
from 5 to 15 parts by weight of at one least surface-active agent
(B) or a combination of 0.5 to 10 parts by weight, preferably from
1 to 10 parts by weight of at least one surface-active agent (B)
and of 2.5.times.10.sup.-4 to 20 parts by weight, preferably of
0.001 to 15 parts by weight of at least one thickening
water-soluble polymer (C) of molecular mass which is higher than 10
000 g/mole, preferably higher than 100 000 g/mole, the said
surface-active agent or mixture of surface-active agents exhibiting
an HLB of at least 10 and the relative quantities of water, of
constituent(s) (B) and optionally (C) being such that the viscosity
or the consistency of the mixture of water+surface-active
agent(s)+optional thickening water-soluble polymer(s) is close to
or higher than one tenth of the viscosity or consistency of the
advantageously masked (poly)isocyanate phase (A), preferably close
to or higher than the viscosity or consistency of the
advantageously masked (poly)isocyanate phase (A); the said blending
being carried out over a period and in shear conditions which are
sufficient to obtain an emulsion of "oil-in-water" type with a
particle size of the order of 0.1 to 5 micrometers, preferably of
the order of 0.2 to 3 micrometers; and in that the mixture is
optionally diluted with water as a function of the desired solids
content.
2) Process according to claim 1), characterized in that the
(poly)isocyanate(s) phase (A) is chosen from the following phases
consisting respectively of: An oil and/or a gum and/or a resin
containing (poly)isocyanate groups of viscosity at least equal to 3
Pa s, preferably of the order of 30 to 2,500 Pa s. Or [sic] of
consistency of the order of 200 to 2,000; A mixture of oil(s)
and/or gum(s) and/or resin(s) containing (poly)isocyanate groups
(s) [sic] mixture of viscosity at least equal to 3 Pa s, preferably
of the order of 30 to 2,500 Pa s. Or [sic] of consistency of the
order of 200 to 2,000; A mixture of oil(s) and/or gum(s) and/or
resin(s) containing (poly)isocyanate groups (s) [sic] and of at
least one solvent for the said oil and/or gum and/or resin, mixture
of viscosity at least equal to 3 Pa s, preferably of the order of
30 to 2,500 Pa s. Or [sic] of consistency of the order of 200 to
2,000.
3) Process according td one of claims 1) to 2), characterized in
that the surface-active agents (B) are nonionic, of HLB higher than
10, preferably of the order of 10 to 20, anionic, cationic,
zwitterionic or amphoteric of HLB higher than 10.
4) Process according to one of claims 1) to 3), characterized in
that the thickening polymers (C) are soluble to at least 50% in
water and are chosen from polyvinyl alcohols, polyethylene glycols,
polyvinylpyrrolidones, alkali metal polyacrylates, carrageenans,
alginates, methyl celluloses, hydroxypropyl celluloses,
hydroxyethyl celluloses etc.
5) Process according to one of claims 1) to 4), characterized in
that the operation of emulsifying of the (poly)isocyanate(s) phase
is carried out by introducing at least one oil and/or one gum
and/or at least one resin into a mixture of water+surface-active
agent(s)+optional water-soluble polymer(s), and then blending at a
temperature of the order of 10 to 50.degree. C. in mixers of the
extruder type with single or multiple screw(s), turbine planet
wheel mixers, static mixers, blade, screw and arm mixers, etc.
6) Process according to one of claims 1) to 5), characterized in
that the said (poly)isocyanate oils and/or gums and/or resins are
masked.
7) Emulsion of the oil-in-water type, characterized in that it
contains at least one (poly)isocyanate(s) and that it can be
obtained by the process according to claim 1.
8) Emulsion of oil-in-water type, characterized in that the said at
least one (poly)isocyanate(s) is masked.
Description
[0001] The present invention relates to a process for the
preparation of emulsions of oils and/or gums and/or resins, which
are preferably viscous. Its subject is more particularly a process
for emulsifying (poly)isocyanates.
[0002] Furthermore, diisocyanates, especially alkylene
diisocyanates (tolonates) and their derivatives of biuret type or
their trimers are widely employed in the activity of paints and
varnishes.
[0003] However, among the problems which remain unsolved to date,
there is one that is particularly acute, namely the use of large
quantity of organic solvent, the presence of which is considered to
be toxic and detrimental to the environment.
[0004] This is why one of the aims of the present invention is to
provide a process which makes it possible to obtain a stable
dispersion of (poly)isocyanates in water.
[0005] Another aim of the present invention is to provide a monomer
which permits (poly)isocyanate formulations in aqueous phase, with
a view to responding to the progress in the techniques and
regulations which tend to make the organic solvents disappear.
[0006] In order to solve this problem, there is already a
description of the preparation of aqueous emulsions of oils,
especially of high viscosity, by separate introduction in two
different steps [sic] of two types of amphiphilic surface-active
agents (which have different "HLB" values when this scale can be
employed) into a conventional mixing apparatus.
[0007] However, these techniques are expensive in respect of
energies and difficult to use. They demand mixing devices capable
of giving high shears.
[0008] This is why one of the aims of the present invention is to
provide a process which makes it possible to employ equipment which
does not give high shears.
[0009] Another aim of the present invention is to provide a process
which avoids high consumptions of energies.
[0010] Another aim of the present invention is to provide a process
which makes it possible to obtain a narrow particle size
distribution of particularly fine droplets.
[0011] The Applicant Company has found a process for the
preparation of aqueous emulsions of viscous phases based on
preferably viscous, advantageously masked (poly)isocyanate oils
and/or gums and/or resins, using a conventional mixing apparatus
and not requiring the obligatory use of two types of surface-active
agents.
[0012] Such a process makes it possible to prepare emulsions of
advantageously masked (poly)isocyanate oils and/or gums and/or
resins of completely controlled and relatively homogeneous particle
size.
[0013] The process forming the subject of the invention is
characterized in that a mixture consisting of the following is
blended
[0014] 100 parts by weight of an advantageously masked
(poly)isocyanate(s) phase (A) of dynamic viscosity at 25.degree. C.
which is at least equal to 3 Pa s, preferably at least equal to 30
Pa s. Or [sic] of consistency at 25.degree. C. which does not
exceed 2000, advantageously masked (poly)isocyanate(s) phase
including at least one oil and/or at least one gum and/or at least
one resin:
[0015] 2 to 20 parts by weight, preferably from 3 to 15 parts by
weight of water;
[0016] 2 to 20 parts by weight, preferably from 3 to 15 parts by
weight of at one least surface-active agent (B) or a combination of
0.5 to 10 parts by weight, preferably of 1 to 10 parts by weight of
at least one surface-active agent (B) and of 2.5.times.10.sup.-4 to
20 parts by weight, preferably of 0.001 to 15 parts by weight of at
least one thickening water-soluble polymer (C) of molecular mass
higher than 10 000 g/mole, preferably higher than 100 000
g/mole,
[0017] the said surface-active agent or mixture of surface-active
agents exhibiting an HLB of at least 10 and the relative quantities
of water and of constituent(s) (B) and optionally (C) being such
that the viscosity or the consistency of the mixture of
water+surface-active agent(s)+optional thickening water-soluble
polymer(s) is close to or higher than one tenth of the viscosity or
consistency of the advantageously masked (poly)isocyanate(s) phase
(A), preferably close to or higher than the viscosity or
consistency of the advantageously masked (poly)isocyanate(s) phase
(A);
[0018] the said blending being carried out over a period and in
shearing conditions which are sufficient to obtain an emulsion of
"oil-in-water" type of particle size of the order of 0.1 to 5
micrometers, preferably of the order of 0.2 to 3 micrometers;
[0019] in that the mixture is then optionally diluted with water as
a function of the desired solids content.
[0020] According to the invention a small scatter is obtained with
a d.sub.90-d.sub.10 which is at most equal to 4, more generally to
1.5 micrometers, preferably to 1 micrometer.
[0021] For a good implementation of the invention the dynamic
viscosity measurements are preferably carried out at 25.degree. C.
with the aid of a Brookfield viscometer according to AFNOR standard
NFT 76 102 of February 1972; the determination of the consistency
may be performed by measuring the penetrability with the aid of a
penetrometer, for example according to one of the standards AFNOR
NFT 60 119, NFT 60 123, NFT 66 004, ASTM D 217, D 937, D 1321 and D
5.
[0022] As examples of advantageously masked (poly)isocyanate(s) (A)
which can be used there may be mentioned those consisting of:
[0023] polymethylene diisocyanates (generally .omega.,.omega.'), it
being possible for the chain sequencing of the methylenes to be
interrupted by an aromatic nucleus or by an oxygen,
[0024] the compounds originating from these derivatives to obtain a
biuret, a dimer or a trimer.
[0025] it is appropriate to cite the prepolymer(s) of these
products, which are formed by the reaction of isocyanate functional
group(s) with a diol in proportions which define the number of the
prepolycondensate units and ensures [sic] that virtually all of the
end functional groups are isocyanates.
[0026] It is also possible to cite the compounds of addition of the
above derivatives to polyols which have at least 3 alcohol
functional groups.
[0027] The isocyanate functional groups are advantageously masked
(this term is preferable to that of "blocked", frequently employed
in texts of Anglo-American sources or those culturally adapted
thereto, and this for two reasons the isocyanate functional group
has actually reacted so that it are no longer at all isocyanate and
when they are "released" there is no certainty in any case that one
passes through an isocyanate intermediate, secondly this masking is
not absolute since properties similar to the isocyanate are
gradually encountered again at certain temperature). [sic]
[0028] According to one of the most surprising methods of the
present invention, it has been possible to demonstrate that the
emulsion technique employed makes it possible to obtain stable
emulsions of unmasked (poly)isocyanate(s).
[0029] The relative chemical instability of the isocyanates in the
presence of phases containing water molecules not only has not
prevented the formation of the emulsion whose physical stability is
remarkable, but also appears to have been significantly reduced by
the emulsification. It appears, to an extent which depends
especially on the dilution, on the surface-active agents and on the
emulsifiers, that the emulsion technique protects the
(poly)isocyanates for a while from chemical decomposition.
[0030] Thus the advantageously masked (poly)isocyanate(s) may
advantageously correspond to the following formula:
A(--NCOblock).sub.p (Formula I)
[0031] where A denotes an organic backbone which has n free
valencies, p being between 2 and 7 (closed interval) advantageously
between 2 and 4 (closed interval);
[0032] where NCOblock denotes an isocyanate functional group which
is advantageously masked (or protected) or otherwise.
[0033] It is appropriate to mention that the total number of
carbons of the said monomer is advantageously between 10 and 100,
preferably between 20 and 100, more preferably between 25 and
75.
[0034] The backbone A may be made up from a heavy polyamine
(including anilines) which, for example, has a carbon number equal
to at least 6 advantageously to 10, preferably to 15 [which is
converted into isocyanate by the action of phosgene in a manner
which is per se known].
[0035] The backbone A may also be that of the trimers and of the
biurets.
[0036] Among the masking groups it is possible to choose groups
containing mobile hydrogen whose pKa is at most equal to 14,
advantageously to 12 preferably to 10 more preferably 8.
[0037] The higher the pKa, the more it is desirable that the
masking agent should be volatile.
[0038] The masking agents are chosen so that the emulsion should be
stable at its storage temperature.
[0039] Among the chemical functional groups capable of masking
isocyanates, the following functional groups may be mentioned by
way of examples, or rather of paradigm:
[0040] alcohols and thiols
[0041] oximes
[0042] hydroxylamines
[0043] acids
[0044] amides and imides
[0045] betadiketones
[0046] pyrazoles
[0047] The advantageously masked (poly)isocyanate(s) phase (A) may
advantageously be chosen from the phases of the list
hereinafter:
[0048] An oil and/or a gum and/or a resin containing a
(poly)isocyanate group of viscosity of at least 3 Pa s, preferably
of the order of 30 to 2,500 Pa s. Or [sic] of consistency of the
order of 200 to 2,000.
[0049] A mixture of oil(s) and/or gum(s) and/or resin(s) containing
a (poly)isocyanate group, mixture of viscosity at least equal to 3
Pa s, preferably of the order of 30 to 2,500 Pa s. Or [sic] of
consistency of the order of 200 to 2,000.
[0050] A mixture of oil(s) and/or gum(s) and/or resin(s) containing
advantageously masked (poly)isocyanate groups and of at least one
solvent (or diluent) for the said oil and/or gum and/or resin,
mixture of viscosity at least equal to 3 Pa s, preferably of the
order of 30 to 2,500 Pa s. Or [sic] of consistency of the order of
200 to 2,000.
[0051] The surface-active agents (B) used may be nonionic of HLB
higher than 10, preferably of the order of 10 to 20, anionic,
cationic, zwitterionic or amphoteric of HLB higher than 10.
[0052] The nonionic surface-active agents may be chosen from
alkoxylated fatty acids, polyalkoxylated alkylphenols,
polyalkoxylated fatty alcohols, polyalkoxylated or polyglycerolated
fatty amides, polyglycerolated alcohols and alphadiols, ethylene
oxide-propylene oxide block polymers etc. As well as
alkylglucosides, alkylpolyglucosides, sugar ethers, sugar esters,
sugar glycerides, sorbitan esters, etc. And the ethoxylated
compounds of these sugar derivatives exhibiting an HLB of at least
10. [sic]
[0053] The anionic surface-active agents may be chosen from alkali
metal alkylbenzenesulphonates, monoalkyl sulphates, alkyl ether
sulphates, alkylaryl ether sulphates, dialkylsulphosuccinates,
alkyl phosphates, ether phosphates, etc., exhibiting an HLB of at
least 10.
[0054] Among the cationic surface-active agents there may be
mentioned aliphatic or aromatic fatty amines, aliphatic fatty
amides, quaternary ammonium derivatives, etc. exhibiting an HLB of
at least 10.
[0055] Among the zwitterionic or amphoteric surface-active agents
there may be mentioned betaines and their derivatives, sultaines
and their derivatives, lecithins, imidazoline derivatives,
glycinates and their derivatives, amidopropionates, fatty amine
oxides, etc. exhibiting an HLB of at least 10.
[0056] The thickening polymers (C) are soluble in water to at least
50%; examples of thickening polymers which may be mentioned
are:
[0057] Those obtained by chemical synthesis, such as polyvinyl
alcohols, polyethylene glycols, polyvinylpyrrolidones, alkali metal
polyacrylates etc.
[0058] Those extracted from plants and optionally modified, such as
carrageenates, alginates, methyl celluloses, hydroxypropyl
celluloses, hydroxyethyl celluloses etc.
[0059] The relative quantities of water, of surface-active agent(s)
and of optional thickening polymer(s) are functions of the
viscosity of the advantageously masked (poly)isocyanate(s) phase
including at least one oil and/or one gum and/or one resin
containing a (poly)isocyanate group and of the nature of the
(mixture of) surfactant(s) and of the nature of the (mixture of)
optional thickening polymer(s).
[0060] In the absence of thickening polymer the weight ratio of
water/water+surface-active agent(s) is, for example, of the order
of 20/100 to 70/100, preferably of the order 25/100 to 60/100 so as
to stabilize an emulsion of an advantageously masked
(poly)isocyanate(s) phase consisting of an oil containing a
(poly)isocyanate group of viscosity of the order of 30 Pa s to 500
Pa s, with the aid of a nonylphenol which has 9 or 10 ethoxy units
as the only surface-active agent.
[0061] The use of an aqueous phase consisting of water and sodium
dodecyl sulphate as the only surface-active agent, in a weight
ratio of water/water+surface-active agent of 5/7 and containing
from 0.5 to 2% of its weight of hydroxyethyl cellulose as
thickening polymer, allows the stabilization of oils of viscosity
of the order of 5 Pa s TO [sic] 30 Pa s.
[0062] It is preferable, above all when the isocyanates are not
masked, to choose thickening agents and surfactants which are
substantially inert towards the isocyanate functional groups under
the conditions of manufacture of the emulsion, especially at the
temperature at which the emulsion is made, and in the storage
conditions.
[0063] The operation of emulsifying the is advantageously masked
(poly)isocyanate(s) phase may be carried out:
[0064] by the introduction of at least one oil and/or one gum
and/or at least one resin+optional solvent(s)+optional
(poly)isocyanate into a mixture of water+surface-active
agent(s)+optional water-soluble polymer(s), the optional filler(s)
being present in the aqueous mixture and/or introduced into the
said mixture, and then blending at a temperature of the order of 10
to 50.degree. C. in mixers of the extruder type with single or
multiple screw(s), turbine planet wheel mixers, static mixers,
blade, screw and arm mixers;
[0065] or, preferably, by introduction of water into an oil(s)
and/or gum(s) and/or resin(s) present in totality or partially [for
example 50-90% of the total quantity of oil(s) and/or gum(s) and/or
resin(s)]+optional solvent(s)+optional filler(s)+surface-active
agent(s)+optional water-soluble polymer(s) mixture, then blending
at a temperature of the order of 10 to 50.degree. C. in mixers of
the extruder type with single or multiple screw(s), turbine planet
wheel mixers, static mixers, blade, screw and arm mixers etc. The
optionally remaining quantity of oil(s) and/or gum(s) and/or
resin(s) being introduced into the mixture after the formation of
the "oil-in-water" emulsion while the blending is maintained.
[sic]
[0066] One of the advantages of the present invention lies in the
use of equipment developing relatively low shears, in general at
least equal to 10.sup.2 but advantageously at most equal to
10.sup.5 preferably to 10.sup.4, more preferably around 10.sup.3.
These reference measurements are carried out in continuous pure
water phase.
[0067] The emulsions of advantageously masked (poly)isocyanate oils
and/or gums and/or resins obtained according to the process of the
invention are particularly stable in storage; they can be very fine
and monodisperse; their solids content may range from 25 (or less,
depending on the intended application of the said emulsions) to
98%, it being possible for the adjustment of the solids content to
be carried out by dilution.
[0068] It is possible to obtain emulsions with organic diluent
contents which are as varied as possible; it is thus possible to
obtain emulsions containing no organic diluents.
[0069] When it is desired to emulsify an unmasked tolonate, it is
preferable that the solids content should be as high as possible in
general at least higher than 3/4 advantageously than {fraction
(9/10)} preferably than {fraction (19/20)}.
[0070] According to the invention it is possible to obtain such
emulsions either directly, for example at higher temperature, or by
producing an emulsion with organic diluent, an emulsion which will
be subsequently treated to evaporate the said organic diluents.
[0071] It is obvious that the organic diluents will have been
chosen so that they are easily capable of being evaporated in
presence of water.
[0072] These emulsions may be employed for the preparation of
(poly)isocyanate-based compositions in virtually all their uses,
etc.
[0073] The invention is also aimed at an emulsion of mixtures of
the (poly)isocyanate(s) with the compounds which must be
polycondensed with it, this being especially when the
(poly)isocyanate(s) are masked.
[0074] In particular, these emulsions may be useful for, and usable
in, paints.
[0075] The composition of the paints may also include a coloured
base. Consisting of a pigment and of titanium oxide. [sic]
[0076] The aqueous phase advantageously contains soluble oligo- or
poly-mers [sic] of polyol or polyol(poly)amine condensate or
polyester-polyol type in sufficient quantity to permit the final
polycondensation.
[0077] Either the condensation reactant(s) is liposoluble and in
this case the emulsion is produced by introducing the said
reactant(s) into the (poly)isocyanates phase (noncontinuous phase)
or by emulsifying them separately and mixing the various emulsions
in which the continuous phase is the aqueous phase; or the
reactant(s) are water-soluble and can, with appropriate
surface-active agents, be used as agent for diluting the aqueous
phase (continuous phase).
[0078] These are the polyols usually employed during condensations
with the common isocyanates.
[0079] Among the polyols it is possible especially to employ those
which are mentioned in European Patent Application published under
No. 0358979, especially when the isocyanates are not masked.
[0080] When the (poly)isocyanate(s) are masked, either phase may
contain a "demasking" catalyst in an appropriate form which is
known per se. Thus, according to an embodiment of the invention the
composition additionally comprises a catalyst for deblocking the
isocyanate functional groups. (cf. Journal of Applied Polymer
Science "Catalysis of the Isocyanate--Hydroxyl Reaction" vol. IV,
issue No. 11, p. 207, (1960), J. W. Britain).
[0081] These catalysts are known in themselves and are
advantageously chosen from those which induce a temperature of
release of the isocyanate functional groups which is at most equal
to the usual temperature of the final operations of setting of the
varnish or of the paint or of equivalents.
[0082] The release temperature induced by the catalysts is
advantageously at least equal to approximately 100.degree. C.
[sic].
[0083] It is appropriate to point out that the protecting groups
are released more easily if the nitrogen of the protected
isocyanate functional group is bonded to an unsaturated, especially
aromatic, carbon, which may sometimes be a drawbacks [sic].
[0084] In the coating application it is preferable that the
nitrogen of the protected isocyanate functional group should be
bonded to a saturated carbon (sp.sup.3 hybridization). In the case
where the isocyanates are not masked; [sic] such isocyanates bonded
to a saturated carbon (sp.sup.3 hybridization) resist hydrolysis
well especially in the case where the said carbon is secondary and
preferably tertiary.
[0085] The backbone A may also be that of the trimers and of the
biurets.
[0086] The mean size of the droplets is advantageously between 0.01
.mu.m and 20 .mu.m, preferably between 0.1 .mu.m and 10 .mu.m.
[0087] The examples are given by way of indication and cannot be
considered as a limit of the field and of the spirit of the
invention.
[0088] Definition
[0089] The Tolonate employed here is the product of the
trimerization of hexamethylene diisocyanate [lacuna]
[0090] The tolonate D2 is the product of the trimerization of
hexamethylene diisocyanate advantageously masked with methyl ethyl
ketoxime and diluted with an aromatic petroleum fraction [Solvesso
100 (registered trademark)] until the latter reaches 25% by
volume.
EXAMPLE 1
[0091] The following are introduced into a closed 250-cm.sup.3
reactor fitted with a scraper blade stirring system (IKA model
(registered trademark) [sic]:
[0092] 2.5 g of Antarox 461 P (registered trademark)
[0093] 2.5 g of water
[0094] The mixture is stirred at 150 revolutions/min.sup.-1 [sic]
for 5 minutes. A thick paste is formed, with a dynamic viscosity of
780 Pa s at a 1 s.sup.-1 shear rate. 85 g of Tolonate D2
(registered trademark), of 4.2 Pa s dynamic viscosity at a shear
rate of 1.sup.-1 [sic] are added over approximately 20 minutes,
with constant stirring at approximately 350 revolutions/min.sup.-1
[sic].
[0095] At the end of the addition of the Tolonate D2 (registered
trademark) the mixture is blended with the same stirring so as to
reach a limiting particle size.
[0096] 10 g of water are added.
[0097] The emulsion obtained has a solids content of 87.5% and a
particle size, measured with the Sympatec (registered trademark)
laser particle size analyser, of 0.6 .mu.m with a d.sub.90-d.sub.10
size distribution equal to 0.70 .mu.m.
EXAMPLE 2
[0098] The operation described above is repeated with, on the one
hand:
[0099] 0.7 g of Antarox 461 P (registered trademark)
[0100] 0.9 g of water
[0101] and, on the other hand, 15 g of methyl ketoxime-blocked
[sic] Tolonate (registered trademark) at a concentration of 15% in
Solvesso. This isocyanate has a dynamic viscosity of 57 Pa s at a
shear rate of 1 s.sup.-1. At the end of the addition of the
Tolonate (registered trademark) the emulsion is stirred for about
ten minutes and then diluted with water to have a Tolonate
(registered trademark) solids content of 70%. The final emulsion
has a particle size, measured with the Sympatec (registered
trademark) laser particle size analyser, of 1.1 .mu.m with a
d.sub.90-d.sub.10 size distribution equal to 1.2 .mu.m.
EXAMPLE 3
[0102] The operation described in Example 1 is repeated with, on
the one hand, the same surface agents and, on the other hand, the
.epsilon.-caprolactam-blocked Tolonate (registered trademark) at a
concentration of 25% in RPDE of dynamic viscosity 7.2 Pa s at a
shear rate of 1 s.sup.-1.
[0103] The emulsion is kept stirred for about fifteen minutes at
350 revolutions/min.sup.-1 [sic] to have a mean particle size,
measured with Sympatec (registered trademark) laser particle size
analyser, of 0.55 .mu.m with a d.sub.90-d.sub.10 size distribution
equal to 0.75 .mu.m.
EXAMPLE 4
[0104] The operation described in Example 1 is repeated with, on
the one hand, the same surface agents and, on the other hand, a
mixture of hydoxylated [sic] polyester resin Desmophen 690
(registered trademark) and of Tolonate D2 (registered trademark) in
the mass ratio of 1:1 which has a 21 Pa s dynamic viscosity at a
shear rate of 1 s.sup.-1.
[0105] The emulsion is kept stirred for about fifteen minutes at
300 revolutions/min.sup.-1 to have a mean particle size, measured
with the Sympatec (registered trademark) laser particle size
analyser, of 1.1 .mu.m with a d.sub.90-d.sub.10 size distribution
equal to 1.4 .mu.m.
[0106] The final emulsion is diluted with water to have a solids
content of 85%.
EXAMPLE 5
[0107] The following are introduced into a closed 250 cm.sup.3
reactor fitted with a scraper blade stirring system:
[0108] 2.0 g of TTAB, cationic surfactant
[0109] 3.0 g of water
[0110] The mixture is stirred at 150 revolutions/min.sup.-1 [sic]
for 5 minutes. A thick paste is formed, with a dynamic viscosity of
86 Pa s at a 1 s.sup.-1 shear rate.
[0111] 80 g of Tolonate D2a (registered trademark), of 5 Pa s
dynamic viscosity at a shear rate of 1 s.sup.-1, are added over
approximately 120 minutes with continuous stirring at approximately
350 revolutions/min.sup.-1. The particle size of the emulsion is
measured for each addition of 10 g. The polydispersity of the
emulsion is followed so as to obtain a D90-D10 [sic] size
distribution close to 0.5 (curve).
[0112] At the end of the addition of the Tolonate D2a (registered
trademark) 10 g of water are added.
[0113] The emulsion obtained has a solids content of 82% and a
particle size, measured with the Sympatec (registered trademark)
laser particle size analyser, of 0.75 .mu.m with a
d.sub.90-d.sub.10 size distribution equal to 0.95 .mu.m.
EXAMPLE 6
[0114] The following are introduced into a 200-cm.sup.3 beaker with
continuous stirring at 300 revolution/min.sup.-1 [sic]:
[0115] 4.0 g of sodium dodecyl sulphate, anionic surfactant
[0116] 4.0 of water [sic].
[0117] A thick paste is formed, with a dynamic viscosity of 93 Pa s
at a 1 s.sup.-1 shear rate, to which 91.5 g of Tolonate D2
(registered trademark) and 2 g of water are added slowly with the
same stirring.
[0118] After addition, the stirring is continued for 10 minutes
while the proportions of the various constituents are kept
constant.
[0119] The concentrated emulsion is diluted by addition of water,
still with the same stirring for 5 minutes. The final emulsion has
the following composition: 73% of Tolonate D2 (registered
trademark), 3.2% of sodium sulphate dodecyl [sic] and 23.8% of
water and a particle size, measured with the Sympatec (registered
trademark) laser particle size analyser, of 0;97 .mu.m [sic] with a
d.sub.90-d.sub.10 size distribution equal to 1.45 .mu.m.
EXAMPLE 7
[0120] The following are introduced into a closed 250-cm.sup.3
reactor fitted with a scraper blade stirring system (IKA model
(registered trademark) [sic]:
[0121] 2.0 g of TTAB cationic surfactant
[0122] 3.0 g of water
[0123] The mixture is stirred at 150 revolutions/min.sup.-1 [sic]
for 5 minutes. A thick paste is formed, with a dynamic viscosity of
86 Pa s at a 1 s.sup.-1 shear rate. 85 g of unmasked Tolonate HDT
(registered trademark) are added over approximately 20 minutes with
continuous stirring at approximately 350 revolutions/min.sup.-1
[sic].
[0124] At the end of the addition of the Tolonate D2 [sic]
(registered trademark), the mixture is blended with the same
stirring so as to reach a limiting particle size.
[0125] 30 g of water are added.
[0126] The emulsion obtained has a solids content of 87.5% and a
particle size, measured with the Sympatec (registered trademark)
laser particle size analyser, of 0.8 .mu.m with a d.sub.90-d.sub.10
size distribution equal to 1 .mu.m.
* * * * *