U.S. patent application number 10/510247 was filed with the patent office on 2005-10-13 for compositions for curing mortar or concrete mixtures ensuring water retention (during setting) and method therefor.
Invention is credited to Dubois-Brugger, Isabelle, Malbault, Olivier, Mosquet, Martin.
Application Number | 20050223948 10/510247 |
Document ID | / |
Family ID | 28052110 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050223948 |
Kind Code |
A1 |
Mosquet, Martin ; et
al. |
October 13, 2005 |
Compositions for curing mortar or concrete mixtures ensuring water
retention (during setting) and method therefor
Abstract
The invention relates to compositions intended to be applied to
surfaces of freshly poured mortar and/or concrete mixes, before the
start of setting, in order to prevent the evaporation of water
needed for them to set and harden, which are distinguished by the
fact that, for the purpose of making them synergistic with regard
to water retention, they are composed, in the form of aqueous
emulsions, of: a) at least one petroleum-derived or synthetic
paraffin wax containing, as a mixture, saturated and unsaturated
aliphatic hydrocarbons of general formulae C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n for which n is at least equal to 30 and the melting
point of which is between 40.degree. C. and 75.degree. C.; b) at
least one linear and/or cyclic hydrocarbon oil, of aliphatic and/or
naphthenic origin, which are hydrocarbon chains, by themselves or
as a mixture, of general formulae C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n for which n is less than 30, in a liquid state at
room temperature; and/or c) at least one oil formed from at least
one ester resulting from the condensation reaction between a
saturated and/or unsaturated fatty acid and a monohydric, dihydric
or trihydric alcohol.
Inventors: |
Mosquet, Martin; (Sermaises,
FR) ; Malbault, Olivier; (Boutigny sur Essonne,
FR) ; Dubois-Brugger, Isabelle; (Avon, FR) |
Correspondence
Address: |
MCCARTER & ENGLISH LLP
CITYPLACE I
185 ASYLUM STREET
HARTFORD
CT
06103
US
|
Family ID: |
28052110 |
Appl. No.: |
10/510247 |
Filed: |
May 2, 2005 |
PCT Filed: |
April 3, 2003 |
PCT NO: |
PCT/FR03/01046 |
Current U.S.
Class: |
106/713 |
Current CPC
Class: |
C04B 40/04 20130101 |
Class at
Publication: |
106/713 |
International
Class: |
C04B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 4, 2002 |
FR |
02/04208 |
Claims
1. Compositions intended to be applied to surfaces of freshly
poured mortar and/or concrete mixes, before the start of setting,
in order to prevent the evaporation of water needed for them to set
and harden, are characterized in that, for the purpose of making
them synergistic with regard to water retention, they are composed,
in the form of aqueous emulsions, of: a) at least one
petroleum-derived or synthetic paraffin wax containing, as a
mixture, saturated and unsaturated aliphatic hydrocarbons of
general formulae C.sub.nH.sub.2n+2 and C.sub.nH.sub.2n for which n
is at least equal to 30 and the melting point of which is between
40.degree. C. and 75.degree. C.; b) at least one linear and/or
cyclic hydrocarbon oil, of aliphatic and/or naphthenic origin,
which are hydrocarbon chains, by themselves or as a mixture, of
general formulae C.sub.nH.sub.2n+2 and C.sub.nH.sub.2n for which n
is less than 30, in a liquid state at room temperature; and/or c)
at least one oil formed from at least one ester resulting from the
condensation reaction between a saturated and/or unsaturated fatty
acid and a monohydric, dihydric or trihydric alcohol.
2. The compositions as claimed in claim 1, characterized in that
the paraffin wax is chosen from the group consisting of alkanes
and/or alkenes, by themselves or as a mixture, which are
petroleum-derived or synthetic saturated and/or unsaturated
hydrocarbons of general formulae C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n in which n preferably takes a value between
30.ltoreq.n.ltoreq.120.
3. The compositions as claimed in claim 2, characterized in that
the paraffin wax has a melting point preferably between 50.degree.
C. and 70.degree. C.
4. The compositions as claimed in claim 3, characterized in that
the paraffin wax has a density of between 0.85 and 0.95 and
preferably between 0.88 and 0.92.
5. The compositions as claimed in claim 4, characterized in that
the hydrocarbon oil is of general formulae C.sub.nH.sub.2n and/or
C.sub.nH.sub.2nl in which n preferably takes a value of between 10
and 25.
6. The compositions as claimed in claim 5, characterized in that
the hydrocarbon oil is chosen from those having a kinematic
viscosity of between 5 and 500 mm.sup.2/s.
7. The compositions as claimed in claim 6, characterized in that
the hydrocarbon oil is chosen from those having a density of
between 0.83 and 0.97.
8. The compositions as claimed in claim 7, characterized in that
the fatty acids used in the preparation of the oil formed from at
least one ester are chosen from the group of C.sub.8 to C.sub.24
fatty acids.
9. The compositions as claimed in claim 8, characterized in that
the fatty acids are chosen from the group consisting of C.sub.8 to
C.sub.24 fatty acids, such as, for example, caprylic, capric,
lauric, myristic, palmitic, stearic, arachidic, behenic,
lignoceric, palmitoleic, oleic, gadaleic, erucic, linoleic,
linolenic, and isolinolenic acids.
10. The compositions as claimed in claim 9, characterized in that
the monohydric, dihydric or trihydric alcohols used in the
preparation of the oil formed from at least one ester are chosen
from the group consisting of C.sub.2 to C.sub.20 alkanols and
alkenols.
11. The compositions as claimed in claim 10, characterized in that
the monohydric alcohol is chosen from the group consisting of
ethanol, propanol, butanol, pentanol, stearic alcohol and oleic
alcohol; the dihydric alcohol is chosen from the group consisting
of propanediol, butanediol, pentanediol, hexanediol, heptanediol,
octanediol, nonanediol, decanediol, undecanediol and dodecanediol
and other dihydroxyalkanes or alkenes; and the trihydric alcohol is
chosen from the group consisting of glycerol, butanetriol,
pentanetriol, hexanetriol, heptanetriol, octanetriol, nonanetriol,
decanetriol, undecanetriol and dodecanetriol and other
trihydroxyalkanes or alkenes.
12. The compositions as claimed in claim 11, characterized in that:
component (a), which is formed from at least one paraffin wax, is
present in said compositions in an amount of 2% to 90% by weight,
preferably 5% to 60% by weight and very preferably 5% to 40% by
weight; component (b), which is formed from at least one
hydrocarbon oil, is present in said compositions in an amount of 5%
to 90% by weight, preferably 8% to 40% by weight and very
preferably 9% to 30% by weight; and/or component (c), which is
formed from at least one oil composed of at least one ester, is
present in said compositions in an amount of 5% to 90% by weight,
preferably 10% to 50% by weight and very preferably 15% to 40% by
weight; and water: Q.S. to 100% by weight.
13. The compositions as claimed in claim 12, characterized in that
the weight ratio of dry active matter of the sum of the oils and of
the paraffin wax that are present is at least 0.25, is preferably
at least 0.63 and is very preferably between 0.64 and 9.
14. The compositions as claimed in claim 13, characterized in that
said compositions, in emulsion form, have a dry matter content of
between 10% by weight and 60% by weight and preferably between 30%
by weight and 50% by weight.
15. A method of preparing the compositions as defined in claim 14,
characterized in that it comprises the successive steps of
introducing the various components into a preparation region
subjected to stirring, the contents of which may be heated and/or
cooled, these steps being: i) the introduction, in the calculated
amount, of water, needed to create the emulsion, optionally
followed by the introduction of an emulsifier into said region,
this first mixing being carried out with vigorous stirring for the
time needed to obtain a homogeneous medium; ii) the introduction,
in the calculated amounts, of the mixture of the oils of component
(b) and/or (c), forming a second mixture, which is subjected to the
same vigorous stirring for the time needed to obtain the first
"oil-in-water" emulsion; iii) the introduction, in the calculated
amount and with gentle stirring, of the paraffin wax into the
second mixture: preheated to a temperature sufficient to cause the
wax to melt and to pass into the emulsion state when said wax is
introduced in the form of a very fine powder; at room temperature
when the wax is introduced in the form of an aqueous emulsion; and
with the gentle stirring maintained for the prolonged time needed
to form the emulsion, possibly with cooling of the emulsion; and
then iv) subjection of the emulsion resulting from the second
mixture converted into an aqueous emulsion to gentle stirring for a
prolonged time in order to homogenize the aqueous emulsion
containing all the components that has been formed.
16. The application of the compositions as defined in claim 14 for
the protection of freshly poured mortar and/or concrete surfaces
from water evaporation by spraying said compositions as aqueous
emulsions onto said surfaces with a useful weight deposited per
unit area of between 50 g/m.sup.2 and 150 g/m.sup.2 in order to
achieve complete protection.
Description
FIELD OF THE INVENTION
[0001] The invention relates to compositions for treating the
surfaces of freshly applied mortar and/or concrete mixes, ensuring
retention of water needed for them to set and harden.
[0002] The invention relates more particularly to curing
compositions for freshly applied mortar and/or concrete mixes in
order to prevent the evaporation of some of the water involved in
their preparation, this water being needed for them to set and
harden, which compositions comprise, in aqueous emulsion, at least
one paraffin wax and at least one ester-based oil and/or at least
one oil based on branched or unbranched, linear and/or cyclic
hydrocarbon chains resulting from the distillation of crude oil,
these various compounds acting in complete synergy.
[0003] The invention also relates to the method of preparing said
compositions and of applying them to the surface of freshly poured
mortar and/or concrete mixes.
[0004] Finally, the invention relates to the use of said
compositions in the form of a layer, deposited on the surface of
freshly poured mortar and/or concrete mixes, applied in order to
ensure water retention within the mortar and/or concrete mixes when
they set and harden, and to maintain within them a sufficient
amount of water for the purpose of preventing, or at the least
limiting, shrinkage effects with the appearance of cracks, and to
maintain, in these mortar and/or concrete mixes, the desired
characteristics such as, for example, a very low shrinkage, good
water impermeability, excellent frost resistance and other
properties.
PRIOR ART
[0005] The incorporation of water into a medium containing a
hydraulic binder among its constituents, such as mortar and/or
concrete mixes, causes irreversible reactions involving the
formation of needle-like crystals by hydration of the initially
amorphous and anhydrous mineral salts present, and results in the
setting of the hydraulic binder by interpenetration of these
needle-like crystals, causing the medium containing them to
thicken, strengthen and then harden.
[0006] Since a hydraulic binder, or a medium containing it, is used
in the open air and since, in addition, the setting reaction is
exothermic, it is known that a fraction of the water incorporated
into the binder, or into the medium containing it, evaporates and
that consequently there is a lack of water for continuing the
crystallization during the maidening step over the course of which
the hydraulic binder, or the medium containing it, acquires all the
desired mechanical properties, such as, for example, a low amount
of shrinkage, water impermeability, low-temperature resistance and
high mechanical strength.
[0007] For a long time one of the most common defects has been the
appearance of cracks during curing, these being due to the
shrinkage of the mortar or concrete containing a hydraulic binder,
this shrinkage very often being the consequence of a loss of water
by evaporation when the medium containing the hydraulic binder,
particularly mortar and concrete mixes, is subjected to the
simultaneous action of the exothermicity developed by the setting
reaction, its exposure to sunshine and to the presence of natural
drying ventilation.
[0008] Various means have been used to make up for, or prevent,
evaporative loss of some of the water incorporated into media
containing, among their constituents, a hydraulic binder such as,
in particular, mortar and concrete mixes.
[0009] According to a first type of means, a conventional and
long-established treatment for preventing water evaporation
consists in keeping the surface of freshly poured mortar and/or
concrete mixes in contact with the most permanently humid
environment possible during the setting time, by the creation of a
sustained film of water or by the use of a textile substrate of
spongy character, imbibed with water, or else by the use of a
polymer film unwound over said surface in order to prevent
evaporation, by creating a greenhouse environment between the
surface to be protected and the atmosphere.
[0010] However, this first type of means is not very practical
nowadays on building sites or sites involving substantial
renovation, as diligent surveillance and consequently mobilization
of the workforce are required.
[0011] According to another type of means, a continuous adherent
and protective film is created on the surface of the mortar and/or
concrete mixes by depositing thereon, by spraying or by brushing, a
paraffin wax by itself or combined with at least one hydrocarbon
resin dissolved in an organic solvent in order to form a barrier
between said surface and the ambient atmosphere and thus prevent
evaporation of the water present in the composition of the mortar
and/or concrete mixes from occurring.
[0012] However, this type of means has several drawbacks, which may
make its use unacceptable. Among the most important drawbacks, the
use of organic solvents constitutes an environmental hazard, most
particularly when solvents are used that are carcinogenic, such as
benzene, toluene and other aromatic solvents, or else halogenated
solvents such as chlorinated hydrocarbons (trichloroethylene and
perchloroethylene). Other major drawbacks are also perceptible,
such as, for example:
[0013] incompatibility between organic solvents and water, which
means having to wait, in order to create the protective film on the
surface to be protected, for the moisture of this surface to be as
low as possible, said film being created once the setting of the
mortar and/or concrete mixes has already been well initiated. As a
consequence, the film is created belatedly and is often inoperative
since the water evaporation, which has to be prevented, has already
started, or is even well advanced;
[0014] poorly controlled, incomplete and irregular degradation of
the film created in order to form a barrier to evaporation, by the
action of ultraviolet radiation that leaves residues of the
protective film adhering to the treated surface; and
[0015] reduction in the adhesion to the surfaces thus treated, of
the finishing materials such as plaster coatings, paints, adhesives
for ceramics and the like, when the film created in order to form
an evaporation barrier is partially degraded at the moment when the
finishing work starts.
[0016] Finally, according to another type of means, a continuous
protective film is created on the surface of the freshly poured
mortar and/or concrete mixes via depositing thereon, by spraying or
brushing, an emulsion in water of a paraffin wax by itself or one
combined with at least one other compound such as a hydrocarbon
resin, a hydrocarbon oil and/or a pigmentary filler and/or fatty
alcohols and/or fatty acids, in order to form, prior to the start
of setting, a barrier between said surface and the ambient
atmosphere and thus prevent the evaporation of water involved in
the composition of the mortar and/or concrete mixes from occurring.
This emulsion has, in common with the mortar and concrete mixes,
the presence of water that makes this type of anti-evaporation
treatment compatible and particularly beneficial.
[0017] Falling within this latter type of means are many documents
that describe water emulsion compositions intended for the surface
treatment of the freshly applied mortar and/or concrete mixes, the
function of which is to prevent evaporation of water involved in
the formation of said mortar and concrete mixes.
[0018] A first document (U.S. Pat. No. 2,928,752) discloses aqueous
emulsions intended for the protection of mortar and/or concrete
surfaces during the setting period, and then at the start of the
hardening period, in order to prevent water evaporation, these
emulsions comprising a paraffin wax, a product resulting from the
reaction of ethylene oxide with an unsaturated oleic alcohol, an
amine salt of a C.sub.12 to C.sub.18 long-chain carboxylic acid, a
c.sub.12 to c.sub.20 long-chain fatty alcohol and, optionally, a
small amount (0 to 10% by weight) of a mineral oil intimately
mixed, when it is present, with the molten wax in order to make
this wax more malleable.
[0019] These compositions, the essential drawback of which is their
complexity owing to the number of components from which they are
formed, are deemed to adhere better to the surfaces of the mortar
and/or concrete mixes to be protected from the evaporation of water
thanks to the presence of the amine functional group which has an
affinity for components of the mortar and/or concrete mixes.
[0020] However, these coating compositions for protecting the
surfaces of mortar and/or concrete mixes, in order to prevent the
evaporation of water, have drawbacks, these being, apart from the
complexity of their formulations, for example:
[0021] deactivation of the mortar and/or concrete by the presence
of the alcohol or acid functional groups, this drawback being well
known to those skilled in the art and manifested by chemical attack
of the surface to be protected, with disappearance of the hydraulic
binder on or around the aggregate present, and creation of an
irregular surface finish after setting and curing;
[0022] introduction of a setting delay on the surface of the
treated mortar and/or concrete, owing to the presence of the
alcohol functional group and, consequently, a delay in the
evaporation;
[0023] lack of adhesion of the finishing materials applied to the
surfaces treated by means of said compositions; and
[0024] water retention that is often insufficient in
surface-treated mortar and/or concrete mixes, resulting in cracking
phenomena.
[0025] Another document (U.S. Pat. No. 3,189,469) discloses aqueous
emulsions with a reflective capacity when they are applied to the
surfaces of freshly poured mortar and/or concrete mixes, to be
protected from water evaporation during the setting period and the
start of curing, which are composed, in combination, of a
hydrocarbon wax, which is essentially a paraffin wax, in an amount
from 15 to 50% by weight, of a product resulting from the reaction
between C.sub.12 to C.sub.22 saturated and unsaturated fatty acids
and an alkaline agent, such as an alkali metal hydroxide, or an
amine in an amount from 1 to 10% by weight of said product, of a
mineral pigment with a high reflecting power, such as TiO.sub.2, in
an amount from 1 to 10% by weight, and a nonionic and anionic
dispersing agent in an amount from 1 to 3% by weight.
[0026] These compositions are regarded as being more adherent to
the surfaces of mortar and/or concrete mixes to be protected from
the evaporation of water, thanks to the presence of the amine
functional group or of the alkaline compound that neutralizes the
acid function of the saturated and unsaturated fatty acids, this
amine functional group and the alkaline compound having the
advantage of exhibiting affinity for the components of the mortar
and/or concrete mixes.
[0027] Despite this advantage, these coating compositions for
protecting the surfaces of mortar and/or concrete mixes in order to
prevent the evaporation of water, while they are setting and
curing, have drawbacks, these being, for example:
[0028] the complexity of their formulation;
[0029] the deactivation of the mortar and/or concrete by the
presence of the acid functional group provided by the fatty acids,
which results in the hydraulic binder being attacked on the
surface, exposing the mineral fillers;
[0030] the introduction of a delay in the setting on the surface of
the treated mortar and/or concrete mixes and, consequently a shift
in the evaporation of the surface water;
[0031] the lack of adhesion of finishing material applied to the
treated surfaces;
[0032] the presence of a pigment such as TiO.sub.2 for providing
said compositions with a high reflectivity capable of helping to
reduce evaporation of water on the surface of the mortar and/or
concrete mixes during setting and hardening; and
[0033] water retention deemed to be insufficient.
[0034] Another document (U.S. Pat. No. 4,239,540) describes an
aqueous emulsion for protecting the surfaces of freshly poured
mortar and/or concrete mixes, in order to prevent the evaporation
of water during the setting period and then the hardening period,
which is composed of a paraffin wax (18.2% by weight), a mixture of
oils formed from a coconut oil (4.2% by weight), a soybean oil
(3.3% by weight), a linseed oil (4.2% by weight), stearic acids
(3.4% by weight), hexacosanoic acid (1.6% by weight), water (62.5%
by weight) and an ethyl/cyanuric acid ester (2.6% by weight) as
emulsifier.
[0035] This aqueous emulsion of very particular and very narrow
composition, which might appear beneficial for treatment for
preventing the evaporation of water from the surfaces of mortar
and/or concrete mixes during setting and curing, is in fact not
able to be exploited as the results indicated show that it has a
very low water retention capability (0.027 to 0.038 g of
water/cm.sup.2). Furthermore, this aqueous emulsion contains
organic acids whose acid functional group:
[0036] has the property of deactivating the mortar and/or concrete
surfaces on which said emulsion is deposited; and
[0037] also causes a delay in surface setting of said treated
mortar and/or concrete mixes.
[0038] Another document (U.S. Pat. No. 4,495,319) discloses a
method of preparing an emulsion intended for the curing treatment
of the surfaces of freshly poured mortar and/or concrete mixes in
order to prevent the evaporation of water present on the surface of
said mortar and/or concrete mixes during the setting period and the
hardening period. This emulsion is formed from a hydrocarbon resin,
a paraffin wax, and emulsifiers obtained from fatty acids and
morpholine. The presence of pigments, such as TiO.sub.2, and/or of
a mineral filler, such as CaCO.sub.3, is also disclosed.
[0039] However, this emulsion has the drawback of being composed of
materials that are solid at room temperature, that is to say
hydrocarbon resins and waxes in the solid state, making it
difficult to prepare the emulsion and resulting in an emulsion that
may be unstable and whose use, as protective film against the
evaporation of water from the surface of freshly poured mortar
and/or concrete mixes, is rather disappointing--the ability of this
emulsion to prevent water loss by evaporation appears to be
insufficient even when this emulsion contains a pigment for
increasing the reflectance thereof and, consequently, for trying to
increase its efficiency.
[0040] Another document (FR-2 691 962) discloses aqueous emulsions
of a paraffin wax and natural or synthetic hydrocarbon resins,
particularly pine resins, which emulsions are intended to be
applied to the surfaces of freshly poured mortar and/or concrete
mixes in order to limit the evaporation of water during the setting
period and the start of hardening.
[0041] However, these emulsions are composed of materials that are
solid at room temperature, making them difficult to prepare, making
their stability for a time uncertain and making their use as
protective film against the evaporation of water from the surface
of mortar and/or concrete mixes unsatisfactory as regards the
stated results (52.8% after two hours--much less than the 85% from
the paraffin wax alone).
SUBJECTS OF THE INVENTION
[0042] As the prior art reveals, the aqueous emulsions proposed and
intended to be applied to surfaces of freshly poured mortar and/or
concrete mixes in order to limit the evaporation of water right
from the start of setting have many drawbacks.
[0043] This is the reason why the subjects of the invention are
numerous and multifarious, as are the aforementioned drawbacks, in
order to provide at least one improvement thereto.
[0044] The various subjects assigned to the invention appear to be
the creation of organic compositions that are aqueous emulsions
provided with necessary and desirable essential characteristics so
that they are applied to surfaces of freshly poured mortar and/or
concrete mixes and, once applied, they limit, and preferably
prevent, evaporation of the water needed absolutely for them to set
and harden.
[0045] Among the essential features assigned to the aqueous
emulsions according to the invention, certain of them are mentioned
by way of illustration. Thus, the aqueous emulsions according to
the invention:
[0046] must be formed, apart from the paraffin wax normally
present, from hydrocarbon compounds that are liquid at room
temperature;
[0047] cannot include compounds liable to deactivate the mortar
and/or concrete mixes that receive them;
[0048] must be free of compounds liable to retard, at the surface,
the setting of the mortar and/or concrete mixes that are covered
thereby;
[0049] must be easy to prepare and be stable after their
preparation;
[0050] must be easy to apply preferably by spraying, onto the
surfaces to be treated;
[0051] must be applied very rapidly to the surfaces of freshly
poured mortar and/or concrete mixes before they start to set;
[0052] must be able to provide said treated surfaces with greater
protection against the evaporation of water than that provided by
the paraffin wax alone;
[0053] must not contain compounds that are particularly harmful to
the environment;
[0054] must be free of carcinogenic compounds such as, in
particular, benzene, toluene and xylene; and
[0055] must allow, after their degradation, good adhesion to the
finishing materials applied to the treated surfaces.
BRIEF DESCRIPTION OF THE INVENTION
[0056] According to the invention, the aqueous emulsions intended
to be applied to surfaces of freshly poured mortar and/or concrete
mixes, in order to prevent the evaporation of water right from the
start of setting, at least partly eliminate the drawbacks
manifested in the prior art and also provide substantial
improvements not existing in the means described hitherto for
making the emulsions particularly effective in the role assigned to
them.
[0057] According to the invention, the compositions intended to be
applied to surfaces of freshly poured mortar and/or concrete mixes,
before the start of setting, in order to prevent the evaporation of
water needed for them to set and harden, are distinguished by the
fact that, for the purpose of making them synergistic with regard
to water retention, they are composed, in the form of aqueous
emulsions, of:
[0058] a) at least one petroleum-derived or synthetic paraffin wax
containing, as a mixture, saturated and unsaturated aliphatic
hydrocarbons of general formulae C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n for which n is at least equal to 30 and the melting
point of which is between 40.degree. C. and 75.degree. C.;
[0059] b) at least one linear and/or cyclic hydrocarbon oil, of
aliphatic and/or naphthenic origin, which are hydrocarbon chains,
by themselves or as a mixture, of general formulae
C.sub.nH.sub.2n+2 and C.sub.nH.sub.2n for which n is less than 30,
in a liquid state at room temperature; and/or
[0060] c) at least one oil formed from at least one ester resulting
from the condensation reaction between a saturated and/or
unsaturated fatty acid and a monohydric, dihydric or trihydric
alcohol.
DETAILED DESCRIPTION OF THE INVENTION
[0061] The compositions according to the invention, intended to be
applied to surfaces of freshly poured mortar and/or concrete mixes
before the start of setting, in order to prevent the evaporation of
the water needed for them to set:
[0062] are aqueous paraffin wax and oil emulsions;
[0063] are synergistic with regard to water retention through their
components and the relative amounts of these various components
involved; and
[0064] are storage stable, even for long periods.
[0065] According to the invention, the compositions intended, by
their presence, to prevent the evaporation of water from freshly
poured mortar and/or concrete mixes, are aqueous paraffin wax
emulsions. As a matter of fact, an emulsion is, by definition, a
dispersion of a liquid compound, or one that is made liquid, in
another liquid compound. In the case of the invention, the
paraffinic compound, called component (a), which at room
temperature is a water-immiscible solid compound, is made liquid by
a slight rise in temperature and simultaneously dispersed in the
water heated to a suitable temperature in order to form by vigorous
stirring, an emulsion. However, the paraffinic compound may already
be in the form of an aqueous emulsion sold and be used in this
state for the preparation of the compositions according to the
invention.
[0066] The paraffin wax, used within the context of the invention
for producing the aforementioned emulsion, is chosen from the group
consisting of alkanes and/or alkenes, by themselves or as a
mixture, which are petroleum-derived or synthetic saturated and/or
unsaturated hydrocarbons of general formulae C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n for which n is at least equal to 30 and preferably
lies between 30.ltoreq.n.ltoreq.120 and the melting point of which
is between 40.degree. C. and 75.degree. C. and preferably between
50.degree. C. and 70.degree. C.
[0067] Depending on the value of "n" and the relative amounts of
alkanes and alkenes forming the paraffin wax employed, the density
of said paraffin wax is between 0.85 and 0.95 and preferably
between 0.88 and 0.92.
[0068] To prevent the emulsion produced by dispersing the molten
paraffin wax in water from undergoing a coalescent effect, that is
to say one in which the paraffin wax and the water separate into
two layers, an emulsifier for promoting stability of the emulsion
may be introduced into said emulsion, this emulsifier being
capillarily active and, as a result of an adsorption phenomenon,
coating the surfaces that separate the paraffin wax microdroplets
from the water, enveloping them with an interfacial film.
[0069] Such an emulsifier may be of the anionic and/or nonionic
kind. It may be chosen from well-known emulsifying products such as
C.sub.8 to C.sub.22 fatty acids neutralized by an amine, in
particular by triethanolamine; sulfonated and phosphonated
compounds; fatty alcohols; sorbitan esters; ethylene
oxide/propylene oxide copolymers, etc. Such emulsifiers are sold,
for example, by SEPPIC under the names SIMULSOL, MONTANE, and
MONTANOX and by Lambert-Rivire under the name SYNTOPON.
[0070] Wax-in-water emulsions, the wax of which meets the
aforementioned characteristics, are sold, for example, by
Exxon-Mobil Oil under the brand names MOBILCER 115, MOBILCER 730,
MOBILCER C, PROWAX 397 and MOBILWAX 2370 or by Suddeutsche
Emulsions Chemie under the brand names WUKONIL KN 50, WUKONIL LP 50
and WUKONIL LP 38 or by Michelman under the brand name
ME91240E.
[0071] The compositions according to the invention also contain at
least one petroleum-derived hydrocarbon oil called component (b),
of aliphatic and/or naphthenic type and, in the latter case,
obtained from the series of cyclopentanes and cyclohexanes, which
are hydrocarbons, present by themselves or as mixtures, which are
saturated and/or unsaturated and of general formulae
C.sub.nH.sub.2n+2 and/or C.sub.nH.sub.2n for which n is less than
30 and preferably between 10 and 25, these hydrocarbon oils being
in a liquid state at room temperature.
[0072] All these oils have, under normal temperature and pressure
conditions, a kinematic viscosity of between 5 and 500 mm2/s and a
density of between 0.83 and 0.97.
[0073] As aliphatic and/or naphthenic hydrocarbon oil, mention may
be made, by way of example, of the oil NEUTRAL sold by Exxon-Mobil,
which has a kinematic viscosity of 20 mm.sup.2/s, or the oils HMVIP
30 and HVI 65 sold by Shell and the oils 60 NEUTRAL, 80 NEUTRAL and
150 NEUTRAL sold by Exxon-Mobil.
[0074] The compositions according to the invention also contain,
combined with or as a replacement for component (b), at least one
oil that is liquid at room temperature and formed by an ester
resulting from the condensation reaction between a saturated and/or
unsaturated fatty acid and a monohydric, dihydric or trihydic
alcohol, constituting component (c).
[0075] The fatty acids used to form the ester according to the
invention are branched or unbranched, saturated and/or unsaturated
hydrocarbon compounds coming from the hydrogenation of oils and
fats, preferably carrying a single carboxylic acid functional
group. They are generally chosen, for example, from the group
consisting of C.sub.8 to C.sub.24 fatty acids, such as for example
caprylic, capric, lauric, myristic, palmitic, stearic, arachidic,
behenic, lignoceric, palmitoleic, oleic, gadaleic, erucic,
linoleic, linolenic and isolinolenic acids.
[0076] The alcohols used to form the ester according to the
invention are hydrocarbon compounds comprising one, two or three
C.sub.2 to C.sub.20 alcohol functional groups. These alcohols may
be chosen from the group consisting of alkanols and/or alkenols,
such as for example ethanol, propanol, butanol, pentanol, stearic
alcohol and oleic alcohol, when a monohydric alcohol is to be used,
from the group consisting for example of propanediol, butanediol,
pentanediol, hexanediol, heptanediol, octanediol, nonanediol,
decanediol, undecanediol and dodecanediol and other
dihydroxyalkanes and alkenes, when a dihydric alcohol is to be used
and/or from the group consisting of glycerol, butanetriol,
pentanetriol, hexanetriol, heptanetriol, octanetriol, nonanetriol,
decanetriol, undecanetriol and dodecanetriol and other
trihydroxyalkanes or alkenes when a trihydric alcohol is to be
used.
[0077] The compositions according to the invention, produced by
means of components (a), (b) or (c), these being:
[0078] petroleum-derived or synthetic paraffin waxes containing, as
a mixture, saturated and/or unsaturated hydrocarbons of general
formula C.sub.nH.sub.2n+2 and/or C.sub.nH.sub.2n with
n.gtoreq.30;
[0079] at least one aliphatic and/or naphthenic, linear and/or
cyclic hydrocarbon oil of general formula C.sub.nH.sub.2n+2 and
C.sub.nH.sub.2n with n.ltoreq.30 in a liquid state at room
temperature; and/or
[0080] at least one oil formed from an ester resulting from the
condensation reaction between a saturated and/or unsaturated fatty
acid and a monohydric, dihydric or trihydric alcohol;
[0081] are synergistic compositions intended to be applied to
surfaces of freshly poured mortar and/or concrete mixes, before the
start of setting, in order to prevent the evaporation necessary for
them to set and harden, the synergistic character of which is
asserted through their ability to prevent the evaporation of water
infinitely better than paraffin wax emulsions by themselves or oils
by themselves.
[0082] This synergistic character is achieved whenever the various
components of these aqueous compositions or emulsions are present,
in percentage amounts of active materials (or dry matter) of:
[0083] component (a) or paraffin wax: from 2% to 90% by weight,
preferably from 5% to 60% by weight and very preferably from 5% to
40% by weight;
[0084] component (b) or hydrocarbon oil: from 5% to 90% by weight,
preferably from 8% to 40% by weight and very preferably from 9% to
30% by weight;
[0085] component (c) or oil formed from at least one ester: from 5%
to 90% by weight, preferably from 10% to 50% by weight and very
preferably from 15% to 40% by weight: and
[0086] water: Q.S. ("sufficient quantity") to 100% by weight.
[0087] In addition, the weight ratio. of dry active matter of the
sum of the oils and of the paraffin wax that are present in the
aqueous emulsions of the compositions according to the invention
must be at least equal to 0.25, may preferably be at least equal to
0.63 and very preferably may vary between 0.64 and 9.
[0088] The compositions according to the invention, in the form of
aqueous emulsions, have a dry matter content that may vary, in
general, from 10% to 60% by weight but preferably from 30% to 50%
by weight.
[0089] Said compositions in the form of aqueous emulsions are used
by spraying them onto the surfaces to be protected, the useful
weight deposited per unit area being between 50 g/m.sup.2 and 150
g/m.sup.2 in order to achieve total protection, that is to say no
evaporation from said surfaces.
[0090] The compositions according to the invention, which are
aqueous emulsions, are storage stable, even for prolonged
periods.
[0091] In addition, when these compositions according to the
invention are applied, they prove to be very effective since, as
opposed to the compositions of the prior art, they require an
infinitely smaller amount of active dry matter deposited per
m.sup.2 of area to be protected, thus making them both very
effective and very inexpensive.
[0092] The invention also relates to a method of preparing the
compositions for protecting surfaces of freshly poured mortar
and/or concrete mixes from water evaporation, which comprises the
successive steps of introducing the various components into a
preparation region subjected to very vigorous stirring, the
contents of which may be heated and/or cooled, these steps
being:
[0093] i) the introduction, in the calculated amount, of water,
needed to create the emulsion, optionally followed by the
introduction of an emulsifier into said region, this first mixing
being carried out with vigorous stirring for the time needed to
obtain a homogeneous medium;
[0094] ii) the introduction, in the calculated amounts, of the
mixture of the oils of component (b) and/or (c), forming a second
mixture, which is subjected to the same vigorous stirring for the
time needed to obtain the first "oil-in-water" emulsion;
[0095] iii) the introduction, in the calculated amount and with
gentle stirring, of the paraffin wax into the second mixture:
[0096] preheated to a temperature sufficient to cause the wax to
melt and to pass into the emulsion state when said wax is
introduced in the form of a very fine powder and
[0097] at room temperature when the wax is introduced in the form
of an aqueous emulsion; and
[0098] with the gentle stirring maintained for the prolonged time
needed to form the emulsion, possibly with cooling of the emulsion;
and then
[0099] iv) subjection of the emulsion resulting from the second
mixture converted into an aqueous emulsion to gentle stirring for a
prolonged time in order to homogenize the aqueous emulsion
containing all the components that has been formed.
[0100] The latter gentle stirring time of step iv) may be up to 90
minutes, or even longer.
EXAMPLE 1
[0101] Compositions according to the invention were prepared, in
the form of an aqueous emulsion, these being formed from:
[0102] paraffin wax: MOBILCER 115 (registered trademark) sold by
Mobil in the form of an aqueous emulsion with a 45% solids content
by weight;
[0103] oil of type (c), which was a triglyceride fatty acid ester
resulting from the esterification of a mixture of acids (Tungoil)
which are eleostearic acid (C.sub.18 acid with three unsaturated
groups) in an amount of 80% by weight, palmitic (C.sub.16) acid in
an amount of 1% and linoleic, linolenic and oleic (C.sub.18) acids
in an amount of 19%, by glycerol; and
[0104] water: Q.S. to 100% by weight.
[0105] The method of preparation was as below.
[0106] Firstly, the amount of water needed to produce the
composition according to the invention, by the formation of an
aqueous emulsion, was introduced into a suitable reactor.
[0107] When the wax had the appearance of an aqueous emulsion, the
amount of water initially introduced took account of the amount of
water contained in the aqueous wax emulsion.
[0108] If required, an emulsifier (surfactant) was introduced into
the initial volume of water, for example MONTANOX 85 (registered
trademark) sold by SEPPIC.
[0109] The water initially introduced was subjected, whether or not
it contained a dispersing agent, to vigorous stirring by a
ULTRA-TURRAX.RTM. stirrer rotating at 20 000 rpm.
[0110] The oil of type (c) was introduced into the aqueous volume,
with this vigorous stirring, forming a mixture which was vigorously
stirred for five minutes, in order to form the "oil-in-water"
emulsion.
[0111] At the end of these five minutes of vigorous stirring, said
stirring was lessened, the rotation speed of the ULTRA-TURRAX.RTM.
being reduced to 5 000 rpm. The aqueous wax emulsion was
introduced, with this gentle stirring, into the oil-in-water
emulsion.
[0112] When the introduction of the aqueous wax emulsion was
complete, the emulsion mixture formed was subjected, for more than
90 minutes, to gentle stirring, the rotation speed of the
ULTRA-TURRAX.RTM. being maintained at 5 000 rpm.
[0113] At the end of this final stirring time, the composition
according to the invention was ready to be applied by spraying, in
an amount of 60 g/m.sup.2 having a 50% solids content by
weight.
[0114] Eight formulations (1 to 8) of compositions according to the
invention were produced, the percentages by weight of the
components of which are given in Table I below.
1TABLE I Total water in Wax Total the solids Ester- solids
Formulation emulsion content based oil content No. (wt %) (wt %)
(wt %) (wt %) 1 50.87 39.13 10.00 49.13 2 50.76 34.24 15.00 49.24 3
50.65 29.35 20.00 49.35 4 50.51 24.46 25.03 49.49 5 50.43 19.57
30.00 49.57 6 50.22 14.54 35.00 49.54 7 49.71 9.99 40.30 50.29 8
49.90 4.99 45.10 50.09
[0115] In the above Table I, the percentage by weight of water
present in the composition according to the invention is the sum of
the water present in the MOBILCER 115 emulsion (having a solids
content of 45 wt %) and of the water introduced as make-up, the
percentage by weight of wax thus being expressed as the % solids
content by weight, and likewise the % by weight of the ester-based
oil employed.
[0116] By way of comparison, four composition formulations in
aqueous emulsion form were prepared, two of them (9 and 10)
containing the same oil emulsified in water as that used in the
eight formulations of the invention, the other two (11 and 12)
containing the same wax emulsified in water as that employed in the
eight formulations of the invention.
[0117] The formulations of each of these comparative compositions
are given in Table II below.
2TABLE II Total water in Wax Ester- Total the solids based solids
Formulation emulsion Emulsifier content oil content No. (wt %) (wt
%) (wt %) (wt %) (wt %) Control 9 62 3 0 35 38 Control 10 48 3 0 49
52 Control 11 55 0 45 0 45 Control 12 82.15 0 14.85 0 14.85
[0118] Trials were carried out on said compositions in the form of
a sprayed layer in the case of each of them, this being deposited
on the surface of the freshly poured mortar and/or concrete mixes,
for the purpose of retaining water within said mortar and/or
concrete mixes until they set, and then harden.
[0119] These surface protection trials were carried out for
equivalent dosage, this dosage being 60 g/m.sup.2 of the emulsion
with a 50% solids content.
[0120] The results of this water retention are given in Table II
below in the form of a protection factor at 6 hours and 24 hours
after pouring the concrete, which indicates the percentage by
weight of water retained on the treated surfaces.
3 TABLE III Protection factor Formulation No. at 6 hours at 24
hours 1 67.9 63.2 2 80.6 75.3 3 79.4 73.5 4 85.9 73.6 5 89.6 78.2 6
88.9 80.5 7 79.3 76.5 8 72.0 70.3 Control 9 58.3 45.3 Control 10
80.9 66.2 Control 11 18.8 12.3 Control 12 13.5 8.4
[0121] These three tables show the following:
[0122] there is good synergy in the compositions according to the
invention since comparison of trials 1 to 8 with control trials 9
and 10 in the case of the oil and 11 and 12 in the case of the wax
shows that the simultaneous presence of the oil and the wax in the
aqueous emulsion composition leads to results in terms of
protection that are greatly superior to the results of the
controls;
[0123] a maximization phenomenon occurs in the protection of the
treated surfaces when the ratio of the percentage oil by weight to
the percentage wax solids content by weight in the compositions
according to the invention is very preferably between 0.64 and 9;
and
[0124] the protection of the treated surfaces is achieved with a
low active dry matter content of the compositions according to the
invention compared with the control compositions.
EXAMPLE 2
[0125] Compositions according to the invention were prepared, in
the form of an aqueous emulsion, these being formed from:
[0126] paraffin wax: MOBILCER 115 (registered trademark) sold by
Mobil in the form of an aqueous emulsion with a 45% solids content
by weight;
[0127] oil of type (b), which is a paraffinic oil, of low viscosity
equal to 20 mm2/s, sold by Mobil under the brand name 60
NEUTRAL;
[0128] water: Q.S. to 100% by weight.
[0129] The method of preparing the compositions according to the
invention was the same as that described in Example 1.
[0130] Seven formulations were produced, the percentages by weight
of the components of which are given in Table IV below.
4TABLE IV Total Paraffin water in Wax waxic Total the solids oil of
solids Formulation emulsion Emulsifier content type b) content No.
(wt %) (wt %) (wt %) (wt %) (wt %) 13 69.57 0.95 23.47 6.00 30.43
14 69.12 1.34 20.54 9.00 30.88 15 68.60 1.79 17.61 12.00 31.40 16
68.77 2.14 14.26 14.53 30.94 17 68.71 2.60 11.27 17.42 31.29 18
68.33 3.10 8.40 20.17 31.67 19 68.02 3.50 5.57 22.91 31.98
[0131] In the above Table IV, the percentage by weight of water
present in the composition according to the invention is the sum of
the water present in the MOBILCER 115 emulsion (having a solids
content of 45 wt %), the percentage by weight of wax thus being
expressed as the % solids content by weight, and likewise the % by
weight of the paraffinic oil employed.
[0132] In addition, compositions 13 to 19 according to the
invention contained an emulsifier, which was a nonionic sorbitan
ester emulsifier, possessing 85 ethylene oxide units, sold by
SEPPIC under the brand name MONTANOX 85.
[0133] By way of comparison, four composition formulations in
aqueous emulsion form were prepared, two of them (20 and 21)
containing the same oil emulsified in water as that used in the
seven formulations of the invention, the other two (22 and 23)
containing the same wax emulsified in water as that employed in the
seven formulations of the invention.
[0134] The formulations of each of these comparative compositions
are given in Table V below.
5TABLE V Total water in Wax Paraffin Total the solids waxic solids
Formulation emulsion Emulsifier content oil content No. (wt %) (wt
%) (wt %) (wt %) (wt %) 20 77 3 0 20 23 21 48 3 0 49 52 22 55 0 45
0 45 23 85.15 0 14.85 0 14.85
[0135] Trials were carried out on said compositions in the form of
a sprayed layer in the case of each of them, this being deposited
on the surface of the freshly poured mortar and/or concrete mixes,
for the purpose of retaining water within said mortar and/or
concrete mixes until they set, and then harden.
[0136] These surface protection trials were carried out for
equivalent dosage, this dosage being 60 g/m.sup.2 of the emulsion
with a 30% solids content in one case and 150 g/m.sup.2 of the 30%
emulsion in the other case.
[0137] The results of this water retention are given in Tables VI
and VII below in the form of a protection factor at 6 hours and 24
hours after pouring the concrete, which indicates the percentage by
weight of water retained on the treated surfaces.
6TABLE VI Surface protection trials carried out with a dosage
equivalent to 60 g/m.sup.2 of the emulsion with a 30% solids
content Protection factor Formulation No. at 6 hours at 24 hours 13
78.6 76.9 14 79.5 77.4 15 82.6 80.3 16 83.5 80.6 17 83.4 81.2 18
82.5 78.7 19 79.0 76.6
[0138]
7TABLE VII Surface protection trials carried out with a dosage
equivalent to 150 g/m.sup.2 of the emulsion with a 30% solids
content Protection factor Formulation No. at 6 hours at 24 hours 13
94.3 92.3 14 95.4 92.9 15 99.1 96.4 16 100 96.7 17 100 97.5 18 99.0
94.4 19 94.9 91.9 Control 20 32.6 25.2 Control 21 77.1 64.8 Control
22 26.0 17.1 Control 23 13.5 8.4
[0139] These three tables show the following:
[0140] there is good synergy in the compositions according to the
invention since comparison of trials 13 to 19 with control trials
20 and 21 in the case of the oil and 22 and 23 in the case of the
wax shows that the simultaneous presence of the oil and the wax in
the aqueous emulsion composition leads to results in terms of
protection that are greatly superior to the results of the
controls;
[0141] a maximization phenomenon occurs in the protection of the
treated surfaces when the ratio of the percentage oil by weight to
the percentage wax solids content by weight in the compositions
according to the invention is very preferably between 0.64 and 9;
and
[0142] the protection of the treated surfaces is achieved with a
low active dry matter content of the compositions according to the
invention compared with the control compositions.
* * * * *