CAPROLACTAM-BASED FATTY AMIDE AS GELLING ADDITIVE
The present invention relates to a fatty amide additive having an amine or salified
amine ending and used as gelator for organic or aqueous media, in particular as
hydrogelator for aqueous media, such as coatings or adhesives or treatment of fibres or
textiles or for detergents, stripping agents, depolluting agents or flocculating agents.
Various systems which can gel in water or in an organic solvent with respectively
hydrogelating and organogelating additives are already known and used in various
applications.
FR 2 976 948 describes a ternary combination of an acid of boron, such as boric
acid, with an N-alkylaldonamide, in particular N-dodecyl-D-glucoanamide, and a
monovalent salt, such as NaCI, for the achievement of gels in a (saline) aqueous medium
for various applications and in particular in detergency.
The known hydrogelators include those based on lysine derivatives, such as
described by M. Suzuki et al. in Chem. Soc. Rev., 2009, 38, 967-975, where derivatives
used as organogelators are also described. A description is given, among these
derivatives, of diurea-esters, amide-esters or amide-urea-esters, starting from lysine.
A review of hydrogelators has been carried out by L.A. Estroff et al. in Chemical
Reviews, 2004, 104, 3, 1201-1217, with an inventory of the characterization methods and
structures which are known. Conventional amphiphilic derivatives having a hydrophilic
head and one or two hydrophobic chains, bolaamphiphiles having two hydrophilic heads
bonded via a hydrophobic chain, surfactants having a double ionic head separated by a
rigid spacer with two flexible end chains, systems derived from sugars, are singled out,
inter alia. It is recognized that there is no rule generally applicable which makes it possible
to find a satisfactory compromise between hydrophilicity and hydrophobicity of a molecule
and consequently there is no general rule either between the ability to form a gel in an
aqueous medium and the tendency to prevent the precipitation of the fibres.
The disadvantage of these hydrogelators or organogelators is the fact that they are
based on amino acids which can undergo side reactions and in particular uncontrolled
chain elongations according to the conditions for the preparation of the said gelators and
can thus affect their fine structure and consequently their performance of gelator.
Furthermore, none of the documents cited describes or teaches how to obtain amide
additives modified by caprolactam and with an improved performance, a subject-matter of
the present invention, in order to overcome the disadvantages of the state of the art.
Specifically, the present invention attempts to develop novel amide additives
modified by a caprolactam structure (equivalent to a C6 amino acid) without having

recourse to amino acids or to acids and to amines which react by polycondensation and in
several stages requiring acyl chlorides.
These novel amides must make possible the use of a preparation process which is
simple and practical to carry out, with the controlled opening of the ring of the caprolactam,
in order to prevent side reactions which are difficult to avoid with an equivalent amino acid
or by acid/amine condensation and without needing stages of separation and/or
purification of the final product. The said novel amides must exhibit a satisfactory gelator
rheological performance in an organic or aqueous medium and in particular in an aqueous
medium, without affecting the specific performances of the binders, in particular aqueous,
which may be used in association with them.
The first subject-matter of the invention is a gelating additive based on fatty amide
which is the product of the addition reaction (without elimination of by-products) of a fatty
amine with caprolactam in a controlled specific ratio with a specific composition.
Thus, the first subject-matter of the invention is a gelating additive based on fatty
amide which is the product of the addition reaction of a fatty amine R1NH2 with
caprolactam with an end amine functional group, either in the amine form or in the salified
ammonium salt form, by neutralization of the said amine functional group by a neutralizing
agent, and which (the said additive) consists of or comprises the mixture of 3 different
amide compounds resulting from the said reaction (condensation) and which are
characterized by the number n of incorporated caprolactam units, which is respectively 1,
2 and 3, with a mean number n of units (mean per molecule) ranging from 0.8 to 3,
preferably from 0.9 to 2.75 and more preferably from 0.9 to 2.5. More particularly, the said
3 amide compounds can be defined according to the formula (I) and respectively
correspond to n = 1, n = 2 and n = 3
R1-NH- [-C(=O)(CH2)5 NH] n-rC(=O)(CH2)5-Y (I)
with Y being -NH2 or -NH3+X-, if the amine is in the salified form and with X- being an
organic or inorganic counteranion related to the acid neutralizing agent used, X-H.
Preferably, the said fatty amine R1NH2 comprises a number of carbon atoms,
ranging from 10 to 24, which means that R1 is a C10 to C24 alkyl, and R1 is preferably linear.
Mention may be made, as suitable examples of R1NH2, of fatty monoamines, such
as ...decylamine, undecylamine, dodecylamine (or laurylamine), tridecylamine,
tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine
(or stearylamine), eicosanamine, doeicosanamine or tetraeicosanamine, or their isomers
and their mixtures. More particularly, the said amine functional group can be in the salified
form, in particular for use as hydro.gelator and the said neutralizing agent used is selected
from organic or inorganic acids.

Mention may be made, as suitable examples of inorganic acid, inter alia, of
hydrochloric acid, sulphuric acid, phosphoric acid, boric acid or nitric acid.
Mention may be made, as suitable examples of organic acids, of carboxylic acids,
sulphonic acids, phosphonic acids and phosphinic acids.
The said additive of the invention can be used in particular in the gel form in water
or in the gel form in an organic solvent, preferably at a content by weight of less than 5%
and more preferably at a content not exceeding 1% by weight, this percentage being
defined with respect to the weight of the water + additive, and more preferably still the
said additive is used as hydrogelator in the gel form in water or, in other words, in the
hydrogel form.
The said additive can be in the form of a micronized powder, preferably having a
volume-average size of less than 50 µm, preferably of less than 25 urn. This particle size
distribution can be determined directly on the dry powder by laser diffraction. This
technique is based on the principle that particles passing through a laser beam diffract the
light along a different angle as a function of their size: the particles having small sizes
diffract at large angles, whereas the particles having larger sizes diffract at small angles.
The said organic solvent is preferably a polar organic solvent or an organic solvent
which is a homogeneous mixture without phase separation and which comprises a polar
organic solvent, such as a C1 to C4 alcohol, dimethyl sulphoxide (DMSO) or
dimethylformamide (DMF), N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP) or a
polar organic plasticizer.
The second subject-matter of the invention is a process for the preparation of the
gelating additive according to the invention, which process comprises a stage of an
addition reaction between a fatty amine P1NH2 and caprolactam with a molar ratio of the
said caprolactam with respect to the said fatty amine ranging from 0.8 to 3, preferably
from 0.9 to 2.75 and more preferably from 0.9 to 2.5, the said process not comprising any
separation or purification stage. This reaction is a bulk addition reaction in the.molten
state, which can take place at a temperature ranging from 200°C to 300°C and under an
inert atmosphere. After cooling, the product obtained is micronized by mechanical grinding
or an air jet. A sieving can make it possible to obtain a fine and controlled particle size
distribution with a volume-average size of less.than .50 µm,. preferably less than 25 µm,
measured by laser diffraction, such as, for example, on the Mastersizer® S from Malvern.
A catalyst can be used for this reaction, such as, for example, a Lewis acid or a Lewis
base.
Another subjeckmatter of the invention is an aqueous composition or a
composition in an organic solvent medium, preferably an aqueous composition, which
comprises at least one additive as defined above or obtained by the process as defined

above according to the invention, the said additive being used as gelator and in particular
for an aqueous composition as hydrogelator and more particularly as rheology additive.
Preferably, the said composition is aqueous and has an acidic pH preferably of less than 5,
more preferably of less than 4.
This pH is also valid for the additive present in the gel form in water (hydrogel).
This pH can be adjusted by addition of the said organic or inorganic acid in excess.
According to a more specific option, the said composition is an aqueous organic
binder composition and in particular a coating composition, more particularly as regards a
coating composition from varnishes, paints or inks or an adhesive or cosmetic
composition or an aqueous composition for the treatment of fibres or textiles and the said
hydrogelating additive is a rheology additive. In this composition option, the said aqueous
composition is an organic binder composition and thus comprises, in addition to the said
additive, at least one organic binder related to the targeted application. According to
another aqueous composition option, this composition may not comprise an organic
binder and may be a composition of the said additive in water in the hydrogel form or it
can be a surfactant, in particular detergent, or stripping agent or depolluting agent or
flocculating agent composition.
In the case where the said additive is used as prganogelator in an organic solvent
medium (or an organic medium), preferably a polar medium, the said composition in an
organic medium which results therefrom can be a composition of the said additive in the
said solvent in the organogel form or it can be a coating composition, in particular from
paints, varnishes, inks or gel coats, or an adhesive composition or a mastic or
leaktightness agent or stripping agent composition or a moulding composition.
The aqueous compositions comprising the said additive as hydrogelator are more
particularly preferred.
The invention also relates to the use of a fatty amide additive as defined above
according to the invention as gelating additive for compositions in an organic solvent
medium, as organogelator, or for aqueous compositions, as hydrogelator. More
particularly, the said additive is used as hydrogelator in water, in order to obtain a
hydrogel, or in an aqueous detergent, depolluting agent, stripping agent or flocculating
agent composition or in an.aqueous coating or adhesive or cosmetic composition or an
aqueous composition for the treatment of fibres or textiles. The aqueous coating
composition is particularly preferred where the said hydrogelating additive is used as
rheology additive.
The said additive can also be used, in particular in the nonsalified form, as
organogelator in an organic solvent, preferably a polar solvent, in order to obtain an
organogel, or in a composition in an organic solvent medium, in particular in a coating

composition from paints, varnishes, inks or gel coats, or in an adhesive composition or in
a cosmetic composition or a moulding composition or a mastic or leaktightness agent or
stripping agent composition.
The gel strength or the gelling intensity depends on and can be adjusted according
to the application targeted and the medium used.
The invention also covers a gel from organogel or hydrogel, in particular hydrogel,
which is the product resulting from the use of the said additive. It is an organogel in an
organic solvent or medium or a hydrogel in water or in an aqueous medium.
Finally, the final product resulting from the use in an aqueous medium, as
hydrogelator and more particularly as rheology additive, of at least one additive as defined
above or obtained by a process as defined above according to the invention, and in
particular the said final product being selected from coating or adhesive or cosmetic or
detergent or stripping agent or depolluting agent or treated fibre or treated textile, also
come within the invention.
The following examples are presented by way of illustration of the invention and of
its performance and, for this reason, do not in any way limit its coverage.

II - Examples of the preparation of caprolactam-based hvdroqelatinq amides
Example 1: Preparation of the amide A1 by reaction of 1 mol of octadecylamine with 1 mol
of caprolactam:

113.16 g of caprolactam (1 mol), 274.84 g of octadecylamine (1 mol) and 1.95 g of
Borchikat® 22 are introduced, under a stream of nitrogen, into a 1 litre reactor equipped
with a thermometer, a condenser and a stirrer.
The mixture is heated to 250°C, still under a stream of nitrogen. The reaction is
controlled by the viscosity. After 15 hours, the viscosity value becomes unvarying (and
>0.23 P or >23 mPa.s, measured on a Brookfield® CAP1000 at 100°C), the reaction
mixture is cooled to 150°C and then it is discharged into a silicone mould. Once cooled to
ambient temperature, the product is micronized mechanically by grinding. A sieving is
carried out in order to obtain a fine and controlled particle size distribution with a mean
size obtained of 7 um.
Example 2: Preparation of the amide A2 by reaction of 1 mol of octadecylamine with 2 mol
of caprolactam:
226.32 g of caprolactam (i.e., 2 mol), 274.84 g of octadecylamine (i.e., 1 mol) and
1.95 g of Borchikat® 22 are introduced, under a stream of nitrogen, into a 1 litre reactor
equipped with a thermometer, a condenser and a stirrer. .
The remainder of the procedure is carried out as described above for Example 1.
Ill - Evaluation of the gelling performance
1. Formulation for the evaluation of the amide additives as hvdrogelators
99 grams of demineralized water, 1 g of ground or micronized hydrogelating .amide
additive to be tested and then a few drops of hydrochloric acid with an excess
corresponding to more than 4 times the amine equivalents of the hydrogelating amide to
be tested are introduced into an Erlenmeyer flask equipped with a magnetic bar. The
Erlenmeyer flask is subsequently closed. The mixture is then stirred for more than 5 hours
at 85°C in order to have complete dissolution of the hydrogelator and a milky but
precipitate-free mixture. Finally, the mixture is introduced into a test tube and then left
standing at 25°C for 24 hours.
Three formulations were prepared under these preparation conditions with the
amide Aland the .amide A2 as. described respectively in Preparation Examples 1 and 2
and also octadecylamine as comparison reference. These 3 tests are summarized in
Table 2 below.


2. Evaluation of the gel
The 3 tests on formulations were evaluated in two ways: first according to the
appearance of the formulations prepared in the test tubes after 24 hours (see Table 3)
and subsequently according to their viscosities at different shear rates on a Brookfield®
viscometer (see Table 4).

* Comment: the results are not very repeatable (reproducible), the formulation not being
homogeneous
In contrast to octadecylamine the formulations with amides A1 or A2 according to
the invention exist in the gel form characteristic of a hydrogelator.

With regard to the viscosity results, they show that the formulation comprising the
amide A1 (Test 2) is thixotropic but also more viscous than water or the formulation
comprising octadecylamine.

CLAIMS
1. Gelating additive based on fatty amide, characterized in that it is the product of the
addition reaction of a fatty amine R1NH2 with caprolactam with an end amine functional
group in the amine form or in the salified ammonium salt form, by neutralization of the said
amine functional group by a neutralizing agent, and that it consists of or comprises the
mixture of 3 different amide compounds resulting from the said reaction and which are
characterized by the number n of incorporated caprolactam units, which is respectively 1,
2 and 3, with a mean number n of units (mean per molecule) ranging from 0.8 to 3,
preferably from 0.9 to 2.75 and more preferably from 0.9 to 2.5.
2. Additive according to Claim 1, characterized in that the said 3 amide compounds
are defined according to the following formula (I) and respectively correspond to n = 1,
n = 2 and n = 3
R1-NH- [-C(=O)(CH2)5 NH] n-1C(=O)(CH2)5-Y (I)
with Y being -NH2 or -NH3+X-, if the amine is in the salified form and with X- being an
organic or inorganic counteranion related to the acid neutralizing agent used, X-H.
3. Additive according to Claim 1 or 2, characterized in that the said fatty amine
comprises a number of carbon atoms ranging from 10 to 24.
4. Additive according to one of Claims 1 to 3, characterized in that the said amine
functional group is in the salified form and that the said neutralizing agent is selected from
organic or inorganic acids.
5. Additjve according to one of Claims 1 to 4, characterized in that the said additive is
in the form of a micronized powder, preferably having a volume-average size of less than
50 urn, preferably of less than 25 urn.
6. Additive according to one of Claims 1 to 5, characterized in that it is in the gel form
in water or in the gel form in an organic solvent, preferably at a content by weight of less
than 5%, more preferably at a content not exceeding 1% by weight, the said additive more
preferably still being used as hydrogelator in the gel form in water.
7. Process for thevpreparation of an/additive as defined according to one of Claims 1
to 6, characterized in that it comprises a stage of an addition reaction between a fatty
amine R1NH2 and caprolactam with a molar ratio of the said caprolactam with respect to

the said fatty amine ranging from 0.8 to 3, preferably from 0.9 to 2.75 and more preferably
from 0.9 to 2.5, the said process not comprising any separation or purification stage.
8. Aqueous composition or composition in an organic solvent medium, preferably an
aqueous composition, characterized in that it comprises at least one additive as defined
according to one of Claims 1 to 6 or as obtained by the process as defined according to
Claim 7 as gelator, in particular as hydrogelator for an aqueous composition.
9. Composition according to Claim 8, characterized in that it is an aqueous
composition and that it has an acidic pH, preferably of less than 5, more preferably of less
than 4.
10. Composition according to Claim 8 or 9, characterized in that it is an aqueous
surfactant and in particular detergent, stripping agent, depolluting agent or flocculating
agent composition.
11. Aqueous composition according to Claim 8 or 9, characterized in that it is an
aqueous organic binder composition, in particular a coating, adhesive or cosmetic
composition or an aqueous composition for the treatment of fibres or textiles, with the said
hydrogelator being a rheology additive.
12. Composition according to Claim 11, characterized in that it is a coating
composition from varnishes, paints or inks.
13. Composition according to Claim 8, characterized in that it is a composition in an
organic solvent medium which is a composition of the said additive in the said solvent in
the organogel form or a coating composition, in particular from paints, varnishes, inks or
gel coats, or an adhesive composition or a mastic or leaktightness agent or stripping
agent composition or a moulding composition.
14. Use of a fatty amide as defined in one of Claims 1 to 6 as gelating additive for
compositions in an organic solvent medium, as organogelator, or aqueous compositions,
as hydrogelator.
15. Use according to Claim 14 characterized in that the said additive is used as
hydrogelator in water, in order to obtain a hydrogel, or in an aqueous detergent,
depolluting agent, stripping agent or flocculating agent composition or in an aqueous

coating composition, in particular an aqueous paint, varnish or ink composition, or in an
adhesive composition or in a cosmetic composition or in a composition for the treatment of
fibres or textiles.
16. Use according to Claim 14, characterized in that the said additive is used as
organogelator in an organic solvent, in order to obtain an organogel, or in a composition in
an organic solvent medium, in particular in a coating composition from paints, varnishes,
inks or gel coats, or in an adhesive composition or in a cosmetic composition or in a
moulding composition or in a mastic or leaktightness agent or stripping agent composition.
17. Gel from organogel or hydrogel, in particular hydrogel, characterized in that it is the
product resulting from the use as defined according to one of Claims 14 to 16 of an
additive, as defined according to one of Claims 1 to 6 or obtained by a process as defined
according to Claim 7.
18. Final product resulting from the use in an aqueous medium, as hydrogelator and
more particularly as rheology additive, of at least one additive as defined according to one
of Claims 1 to 6 or obtained by a process as defined according to Claim 7, in particular
selected from coating or adhesive or cosmetic or detergent or stripping agent or
depolluting agent or treated fibre or treated textile.