EP3328815A1

EP3328815A1 - Process for creating patterns on the surface of a composition based on hydraulic binder by printing

Info

Publication number: EP3328815A1
Application number: EP16745701.9A
Authority: EP
Inventors: Mathias Agnely; Sandrine Mateo; Bruno Pellerin
Original assignee: Chryso SAS
Current assignee: Chryso SAS
Priority date: 2015-07-31
Filing date: 2016-07-28
Publication date: 2018-06-06
Also published as: US20180215673A1; FR3039541B1; CA2994197A1; WO2017021284A1; ZA201800662B; FR3039541A1

Abstract

The application relates to a process for creating patterns on a surface of a composition based on hydraulic binder, comprising the application, by printing, of a deactivating (D1) or acid (A1) composition to a portion or to the whole of a surface of a composition based on hydraulic binder.

Description

Method of creating patterns on the surface of a hydraulic binder-based composition by printing

The present invention relates to a process for creating patterns on a surface of a composition based on hydraulic binder, especially concrete, by printing.

Concrete is a building material used in the manufacture of elements that can have very different forms and aspects.

The deactivated concrete, whose aggregates are apparent, allows in particular to decline in a wide range of aspects and colors. It is found on building sites (sidewalks, squares, car parks, courtyards, walks ...) but also in the manufacture of street furniture (planters, garbage cans ...), gravel tiles or wall panels.

The final appearance of deactivated concrete depends mainly on its composition. In particular, the aggregates used can be of different sizes, shapes and colors (white marble, red rock ...). Moreover, the color of the cement can add a specific touch, since it can be chosen gray, white or dyed by a dye.

The realization of deactivated concrete requires the application on the concrete surface of an agent to delay the setting of concrete surface. This agent is generally called "surface deactivator" or "surface setting retarder".

When it is desired to produce large-area molded parts or parts whose deactivated surface is not in contact with the mold, for example parts intended to form soils, the deactivating agent is sprayed on the surface of the concrete after it has been put into operation. in place and the float. Thus used, the deactivating agent is called "deactivating positive".

In contact with the surface of a composition based on fresh hydraulic binder, the surface deactivator penetrates by diffusion to a certain depth and induces retardation of setting. The surface uncured hydraulic binder layer remains brittle and can be removed. The objective is to make the aggregates appear on the surface. The depth of the layer retarded by the deactivating composition, also called digging force or attack force, is mainly chosen according to the size of the aggregates present. The objective is to make the aggregates appear on the surface, so the digging force depends on the desired aesthetic effect, as well as the size of the aggregates. The deactivating composition is chosen according to the desired effect, typically the larger the aggregates, the greater the need for the composition to have a large digging force. It may be interesting, for aesthetic reasons, to inscribe elements in the concrete, etc. to have a method for creating patterns on the concrete surface.

According to a first alternative, these patterns can be created by deactivating the desired areas of the surface of a composition based on fresh hydraulic binder.

The patent application EP 1 177 081 describes a method of creating a concrete coating having patterns with a deactivating agent transferred to a surface in contact with the concrete to be molded by means of a printing technique . In this application, the deactivating agent is placed on a surface that will be placed in contact with the concrete, but not on the surface of the concrete itself. In one embodiment, this surface is a membrane on which patterns have been printed using the deactivating agent as ink. The membrane is deposited at the bottom of the mold in which the concrete will be poured. It is therefore necessary to prepare or buy a printed membrane. In addition, once used, the membrane is a waste to be eliminated. In another embodiment, this surface is the mold in which the concrete will be poured. Thus, the desired patterns comprising the deactivating agent are printed directly at the bottom of the mold. This embodiment is however applicable only for molded parts.

Patent Application WO 2014/006102 discloses a method for patterning a surface of a hydraulic binder composition, comprising depositing a stencil on the surface of the fresh hydraulic binder composition and then storing the same. applying a deactivating composition (D1) to the surface thus covered. Again, it is necessary to prepare or buy a stencil, and the stencil is a waste to be removed after use.

According to a second alternative, these patterns can be created by acid etching of the desired areas of the surface of a cured hydraulic binder composition.

The patent application US 2010/0313519 describes a method for creating a non-slip hydraulic binder composition surface, one of the steps of which is the application of an acidic solution on the surface to attack and render it the apparent aggregate. The acid solution is applied by a sprinkler system or a sprayer. Application of the acidic solution to a localized portion of the surface to reveal surface patterns is not suggested. The surface may contain patterns, but these are created by making cuts in the composition based on fresh hydraulic binder, the geometry of which corresponds to the desired patterns. The development of a method of creating patterns on the surface of a concrete of a workpiece that can be molded or not and that does not require a membrane or stencil is therefore required.

To this end, the invention relates to a process for creating patterns on a surface of a composition based on hydraulic binder, comprising the application by printing of a deactivating composition (D1) or acid (A1) on part or all of a surface of a composition based on hydraulic binder.

Advantageously, the composition based on hydraulic binder used in the process according to the invention may be in the form of a molded part or an unmolded part.

In addition, the method according to the invention does not require stencil or membrane. There is therefore no prior step of preparing a stencil or a printed membrane. In addition, once the process implemented, there is no waste to eliminate.

Advantageously, the method provides access to an unlimited number of pattern shapes and patterns of complex shapes.

The method can be used for any type of hydraulic binder-based compositions, and regardless of the shape of the part formed by the hydraulic binder-based composition, including for a part whose surface to be deactivated is not flat, as detailed below.

The term "hydraulic binder" is understood to mean any compound having the property of hydrating in the presence of water and whose hydration makes it possible to obtain a solid having mechanical characteristics. The hydraulic binder can comprise or consist of a cement according to the EN 197-1 standard and in particular a CEM I, CEM II, CEM III, CEM IV or CEM V type cement according to the NF EN 197-1 (2012) cement standard. The cement can therefore in particular comprise mineral additions.

The term "composition based on hydraulic binder" means a composition comprising a hydraulic binder. It may be a composition based on fresh hydraulic binder, which then corresponds to a "hydraulic binder composition", or a composition based on hardened hydraulic binder, such as concrete.

The term "fresh" refers to such hydraulic binder-based compositions when they have been tempered with water, but have not yet hardened. It is then malleable enough to fill the mold or formwork.

The term "hardened" is understood to mean such hydraulic binder-based compositions when cured. By the term "setting" is meant the passage to the solid state by hydration reaction of the binder.

By the term "concrete" is meant a mixture of hydraulic binders, aggregates, sands, water, optionally additives, and possibly mineral additions. The term "concrete" also includes mortars and screeds.

The term "mineral additions" refers to slags (as defined in NF Cement Standard EN 197-1 (2012) section 5.2.2), steelmaking slags, pozzolanic materials (as defined in NF Cement Standard). EN 197-1 paragraph 5.2.3), fly ash (as defined in standard Cement NF EN 197-1 paragraph 5.2.4), calcined schists (as defined in standard Cement NF EN 197-1 paragraph 5.2 .5), limestones (as defined in standard Cement NF EN 197-1 paragraph 5.2.6) or even fumes of silicas (as defined in standard Cement NF EN 197-1 paragraph 5.2.7) or their mixtures. Other additions, not currently recognized by the standard Cement NF EN 197-1 (2012), can also be used. These include metakaolins, such as type A metakaolins conforming to standard NF P 18-513, and siliceous additions, such as the siliceous additions of mineralogy Qz conforming to standard NF P 18-509 (2012). .

By the term "aggregates" is meant a set of mineral grains with a mean diameter of between 0 and 125 mm. Depending on their diameter, aggregates are classified into one of six families: fillers, sand, sand, gravels, chippings and ballast (standard XP P 18-545 of September 201 1). The most widely used aggregates are the following: fillers, which have a diameter of less than 2 mm and for which at least 85% of the aggregates have a diameter less than 1.25 mm and at least 70% of the aggregates have a diameter less than 0.063 mm, sands with a diameter between 0 and 4 mm (in standard 13-242, diameter up to 6 mm), lobes with a diameter greater than 6.3 mm, gravel diameters between 2 and mm and 63 mm. Sand is therefore included in the definition of granulate according to the invention. The fillers may in particular be of calcareous, siliceous or dolomitic origin.

In the process according to the invention, a deactivating (D1) or acid (A1) composition is applied to part or all of a surface of the hydraulic binder composition by printing. Both the deactivating (D1) and acid (A1) printing compositions are capable of etching / digging the hydraulic binder composition to form patterns. In the process according to the invention, the patterns are created by removing a portion of the hydraulic binder composition. Patterns are not created by adding material to the hydraulic binder composition. Preferably, the deactivating (D1) or acid (A1) composition is applied to a portion of the surface of the hydraulic binder composition.

If a repeated pattern is produced, for example on an aisle, the application step can be performed by printing a deactivating (D1) or acid (A1) composition on a first part of the surface. of the hydraulic binder composition, then repeat this step for each part, which allows to create each pattern of the aisle one after the other. Typically, the printer is placed where a pattern is desired, then, after printing, moved to the next location where a pattern is desired, and repeated as many times as necessary.

In the process according to the invention, the deactivating (D1) or acidic

(A1) is applied by printing. Typically, this composition is the printing ink.

Preferably, in the method according to the invention, the printing is carried out by an ink jet printer. For example, a PolyJet printer (Stratasys company) can be used. The print head of the inkjet printer expels a jet / droplets of deactivating composition (D1) (or possibly another deactivating composition, for example a deactivating composition (D2) or (D3) described hereinafter) or of acid composition (A1) (or optionally of another acid composition, for example of an acid composition (A2) or (A3) described hereinafter) . The jet forms dots on the surface of the hydraulic binder composition. The patterns are formed by dot concentrations.

Advantageously, with an ink jet printer, the diameter of the expelled jet / expelled droplets is controllable, which makes it possible to control the resolution of the printing, the amount of deactivating composition (D1) or acid (A1 ) deposited at a given location on the surface, and thus digs at a given location. The larger the diameter of the expelled jet / expelled droplets, the better the fineness of the details obtained, but the faster the treatment of a given surface.

"Hollow" means the difference in height between:

the surface of the composition based on hydraulic binder before printing, and

the lowest point of the surface of the hydraulic binder-based composition to which the deactivating composition (D1) has been applied, this point being obtained after the step of removing the uncured hydraulic binder layer; surface, or the lowest point of the surface of the hydraulic binder-based composition to which the acid composition (A1) has been applied, this point being obtained after the rinsing step of the cured hydraulic binder-based composition .

The hollow refers to a given area of the surface of the composition based on hydraulic binder. Indeed, the surface of the composition based on hydraulic binder may have different digs, as explained below.

The smaller the droplet / jet diameter, the better the definition of the pattern, but the longer the printing. Therefore, the droplet / jet diameter is a compromise between the definition of patterns, the desired hollow and the speed of printing.

The diameter of the expelled droplets can be measured by laser diffraction, for example with a Malvern Spraytec apparatus. Generally, droplets have a diameter measured by laser diffraction between 1 μηι and 1000 μηι, for example between 2 μηι and 500 μηι. For example, PolyJet printers (Stratasys company) make it possible to achieve these droplet sizes even for viscous liquids. On parts of several meters of side, the desired precision of the position of the pattern is of the order of a few hundred microns.

In one embodiment, the surface of the hydraulic binder composition is planar. The printing can then be performed with a printer to control the location of the application of the deactivating composition (D1) or acid (A1) in two dimensions. The printing is then performed by a conventional printer that allows to apply a controlled amount of printing ink at a point of coordinates (X, Y) controlled.

In another embodiment, the surface of the hydraulic binder composition is not planar. The printing can then be performed with a printer to control the location of the application of the deactivating composition (D1) or acid (A1) in three dimensions. The printing is then performed by a printer which makes it possible to apply a controlled quantity of printing ink at a controlled coordinate point (X, Y, Z). Such an impression is not necessarily a "3D printing" in the usual sense of the term, because in this embodiment of the method according to the invention, the application of the deactivating composition (D1) or acid (A1) is not an additive manufacturing process (we do not form a new object). However, printing can be done by a 3D printer. By "3D printer" is meant a system for programmatically depositing a quantity of material at a point defined by its coordinates in the three dimensions of the space. According to a first alternative, the method comprises the application by printing of a deactivating composition (D1) on part or all of a surface of a composition based on fresh hydraulic binder.

The method according to the invention generally comprises, before the step of applying by printing the deactivating composition (D1) on the composition based on fresh hydraulic binder, a step of shaping the composition based on hydraulic binder. fresh.

Typically, the shaping is performed by casting, float and if necessary by vibration.

Bubbles and / or air lenses may form on the surface of the fresh hydraulic binder composition. They come from the upwelling of the composition based on fresh hydraulic binder. Air bubbles can be very difficult to remove even by smoothing the surface and impart an unsightly appearance to the hardened surface. To limit this phenomenon, the composition based on fresh hydraulic binder is advantageously floated before application of the deactivating composition (D1). Advantageously, the process according to the invention makes it possible to limit the appearance of unsightly bubbles or air lenses on the surface of the composition based on hydraulic binder than the processes of the prior art using a stencil or a membrane. , especially those described above. Indeed, in these processes, bubbles may form at the interface between the surface of the fresh hydraulic binder composition and the stencil or membrane.

In a particular embodiment, the shaping of the composition based on fresh hydraulic binder is performed by 3D printing (by an additive manufacturing process). Typically, the method then comprises a step of shaping the composition based on fresh hydraulic binder by a 3D printer, and a step of application by the 3D printer of the deactivating composition (D1) on a part of the surface of the composition based on fresh hydraulic binder. The shaping step and the application step of the deactivating composition (D1) can be successive or simultaneous.

Different levels of deactivation (or digging) may be desired for a given pattern. Two embodiments of this first alternative of the method are conceivable to obtain this effect.

According to a first embodiment, the method comprises the application by printing of a deactivating composition (D1) on part or all of a surface of a composition based on fresh hydraulic binder, then another application. by printing the deactivating composition (D1) on a part of the surface on which of the deactivating composition (D1) has been applied, this other application possibly being repeatable. This first embodiment makes it possible to apply different amounts of deactivating composition (D1) to different parts of the surface of the fresh hydraulic binder-based composition which it is desired to deactivate. Typically, successive passes of the printhead of the printer are performed on the part (s) of the surface for which a deeper hollow is desired. The greater the amount of deactivating composition (D1), the deeper the resulting hollow will be. Thus, to obtain a pattern with two levels of deactivation, the deactivating composition (D1) is applied once to a first part of the surface, and more than once (typically twice) to a second part of the surface. . Similarly, to obtain a pattern with three levels of deactivation, for example, the deactivating composition (D1) is applied once to a first portion of the surface, twice to a second portion of the surface, and three times to a third part of the surface.

In this first embodiment, the method may comprise, between two successive applications of deactivating composition (D1), an accelerated drying step of the part of the surface on which the other application will be carried out. This drying can be carried out under UV or infrared light. It allows faster preparation and a sharper outline of the different levels of the pattern.

According to a second embodiment, the method comprises applying by printing a deactivating composition (D1) on part or all of a surface of a composition based on fresh hydraulic binder, and then applying by printing a deactivating composition (D2) on part or all of the surface of the fresh hydraulic binder composition, it being understood that the deactivating compositions (D1) and (D2) have off-axis forces different and are not applied to identical surfaces.

Of course, the fact that the deactivating compositions (D1) and (D2) are not applied to identical surfaces does not exclude that the surface on which the deactivating composition (D1) is applied is included in the surface on which the deactivating composition (D2) is applied, or vice versa. In addition, the fact that the deactivating compositions (D1) and (D2) are not applied to identical surfaces does not exclude that the deactivating compositions (D1) and (D2) are applied to surfaces which are overlap. When they overlap, a pattern with three levels of deactivation will be obtained: a first part of the pattern with a first level of hollow on which only the deactivating composition (D1) has been applied, a second part of the pattern with a second level of hollow on which only the deactivating composition (D2) has been applied, and a third part of the pattern with a third level of hollow on which the deactivating compositions (D1) and ( D2) have been applied.

Of course, as many different hollow force deactivating compositions can be used as desired. Thus, in one embodiment of this second embodiment, the method comprises applying by printing a deactivating composition (D1) to a portion or to an entire surface of a binder-based composition. cool hydraulic, then applying by printing a deactivating composition (D2) on part or all of the surface of the fresh hydraulic binder composition, and then applying by printing a deactivating composition (D3) on part or all of the surface of the fresh hydraulic binder composition, it being understood that the deactivating compositions (D1), (D2) and (D3) have different digging forces and are not not applied to identical surfaces.

Typically, each deactivator composition (D1), (D2) and (D3) corresponds to the ink of an ink cartridge of the printer.

The deactivating compositions (D1), (D2) and (D3) comprise a surface setting retarder. They may be in the form of a solution in an aqueous or oily solvent or in a petroleum fraction, or in the form of a dispersion in an aqueous or oily solvent or in a petroleum fraction, in particular in the form of a suspension or in the form of an emulsion.

In the context of this disclosure, the term "surface setting retarder" is intended to mean a compound having the effect of delaying the setting of the composition based on hydraulic binder, that is to say of delaying or inhibiting the related phenomena such as hydration phenomena, thereby inducing a later hardening of the composition. In general, a surface-setting retarder delays the setting time of a composition based on hydraulic binder in which it has been introduced at a dosage of at most 5% by dry weight relative to the weight of said hydraulic binder, setting time being measured according to test EN480-2 (2006). Preferably, setting time is delayed by at least 30 minutes with respect to a control hydraulic binder composition.

In the context of the invention, the term "oily solvent" a solvent comprising fats of vegetable origin, animal or mineral, which may be liquid at room temperature or not. These oils can be recycled or regenerated. However, when they are not liquid at room temperature, the composition is preferably prepared at a temperature at which all its components are liquid.

The vegetable oil may especially be chosen from rapeseed oil, palm oil, coconut oil, castor oil, peanut oil, grape seed oil, corn oil, canola oil, linseed oil, coconut oil, soybean oil, sunflower oil and mixtures thereof.

The animal oils can be chosen in particular from tallow, suintine, lard oil, herring oil, cod liver oil, sardine oil, fish oil and oil. lanolin and mixtures thereof.

The mineral oils may in particular be aliphatic, paraffinic or naphthenic oils, they include, in particular, the fractions comprising on average 8 to 30 carbon atoms, preferably 1 to 25 carbon atoms, alone or as a mixture, in particular mineral oil. Claire. The preferred oils will be mineral oils CnH2n + 2, with n between 8 and 19.

In the context of the present invention, the term "emulsion" denotes both water-in-oil emulsions and oil-in-water emulsions, the oil being chosen in particular from the oils mentioned above.

The retarder of the deactivating composition (D1), (D2) and (D3) used in the process according to the invention is chosen from the compounds known for this purpose.

The surface-setting retarder of the deactivating composition in aqueous solvent may be chosen from compounds known for this purpose, such as carboxylic acids, their salts and their derivatives; carbohydrates, especially sugars, their salts and derivatives; but also lignosulfonic acid, phosphonic acids, in particular those carrying amino or hydroxy groups, their salts and their derivatives; or inorganic acids such as phosphoric acid, their salts and derivatives.

In the context of the present invention, derivatives of carboxylic acids, carbohydrates, lignosulfonic acids, phosphonic acids, in particular those bearing amino or hydroxy groups; and inorganic acids, also include the salts of these derivatives.

The surface-setting retarder of the deactivating composition in aqueous solution is preferably selected from carboxylic acids, their salts and their derivatives; sugars, their salts and their derivatives; or a mixture thereof.

Of the sugars, the surface-setting retarder of the deactivating composition may be chosen in particular from glucose, fructose, sucrose, meritose, lactose, maltotriose, dextrose, maltose, galactose and mannose. , glycogen or one of their mixtures.

Among the carboxylic acids, mention may in particular be made of maleic acid and hydroxycarboxylic acids and among these in particular citric acid, tartaric acid, malic acid, gluconic acid, and lactic acid, their salts or a mixture thereof.

Among the carboxylic acid salts, mention may be made of sodium salts, calcium salts or potassium salts. As a particular example, mention may be made of sodium citrate, sodium tartrate or sodium gluconate.

The term "carboxylic acid derivatives" is intended to denote their salts and esters, by way of a particular example, mention may be made of ethyl acetate.

In the case of hydroxycarboxylic acids, the derivatives include lactones.

The surface-setting retarder of the deactivating composition in oily solution may be chosen from the compounds known for this purpose, such as those disclosed in application EP 2 935 140, in particular the alkyl esters of hydroxycarboxylic acids which are soluble in oils / solvents. , or dispersible in oils / solvents. It is for example an alkyl ester of citric acid such as triethyl citrate.

The retarder of the deactivating composition used in the emulsions may be chosen from the aqueous solvent retarders and the oily solvent retarders defined above.

The retardant of the deactivating composition in solution in an emulsion, in particular in an oil-in-water emulsion, may be chosen from carboxylic or hydroxycarboxylic acids which may comprise a saturated or unsaturated carbon chain and have 1, 2 or 3 hydroxyl groups, it may also be be in the form of a salt, especially sodium salt, potassium salt or calcium salt. The acid is preferably selected from acetic acid, gluconic acid, citric acid, tartaric acid, maleic acid, mixtures thereof or salts thereof. Particularly preferred are citric acid, malic acid and tartaric acid. In the case of oil-in-water emulsion, the emulsion preferably comprises from 5 to 50% by weight of oily phase, preferably from 10 to 40% and from 50 to 95% by weight of aqueous phase, preferably from 60 to 90%. In the case of an emulsion, the deactivating composition further comprises a surfactant. For oil-in-water emulsions the surfactant is preferably a non-quaternary amine surfactant. Such oil-in-water emulsions are described in application WO 2012/056162.

The surface-setting retarder of the deactivating composition in solution in the petroleum fractions may be chosen from the aforementioned retarders for the phases aqueous or oily which are crushed and then dispersed within the oil cuts.

The deactivating composition (D1), (D2) or (D3) generally comprises from 0.1 to 20% by weight of surface setting retarder. Typically, when an ink jet printer is used, the proportions of retarding agent in the deactivating composition (D1), (D2) or (D3) are adapted so that the surface setting retarder is in a proportion from 0.01 to 100 g / m ² , preferably from 0.1 to 10 g / m ² , more preferably from 0.5 to 5 g / m ² relative to the jet section.

Advantageously, the deactivating compositions (D1), (D2) and optionally (D3) if a deactivating composition (D3) is used, have the same type of formulation (for example liquids, or water-in-oil emulsions, or emulsions oil in water) and / or include solvents of the same nature, for example water, or an oil of the same kind, or a petroleum cut.

The deactivating compositions (D1), (D2) and (D3) have different hollow forces.

This different digging force can be achieved by using an identical surface setting retarder in the deactivating compositions, but at a different concentration (generally, the higher the surface setting retardation concentration in the deactivating composition, the greater the hollow force is high).

This different digging force can also be obtained by using deactivating compositions comprising surface-setting retardants of different natures and having different digging forces. Preferably, the deactivating compositions (D1), (D2) and optionally (D3) if a deactivating composition (D3) is used, then differ only in the nature of the retarder, and possibly by the nature of the possible additives.

The deactivating compositions (D1), (D2) and / or (D3) may optionally contain additives making it possible to improve its properties chosen from fillers, opacifying agents, anti-foam agents, surfactants, agents and curing agents, biocides, thickeners, pigments, wetting agents (to improve the regularity of the application of the deactivating composition (D1) to the surface), plasticizers, film-forming agents, dispersants, viscosity regulating agents (especially for net deposition of the droplet during printing, without spreading or shrinking), antioxidants (in particular to prevent the decomposition of the surface-setting retarder, in particular in case of local drying forced) or a mixture of these.

In particular, the deactivating composition may comprise a viscosity regulating agent to adjust the rheological properties of the deactivating composition. used to allow easy application by printing. Preferably, the deactivating (D1) and / or (D2) and / or (D3) composition has a Brookfield viscosity of less than 500 mPa.s measured at 20 ° C.

Preferably, these viscosity-regulating agents are present in the deactivating composition at contents not exceeding 15% by weight, and preferably not exceeding 10% by weight.

The deactivating composition may also include a curing agent. The curing agents are chosen in particular from vegetable oils, animal oils or mineral oils such as those described above.

The curing agents may also be chosen from solubilized resins in a solvent as described in application FR 2 828 192, styrene-butadiene latices, aqueous emulsions of acrylic resin as described in patent application EP 1 661 874, paraffinic emulsions, acrylic polymers. They may also be chosen from emulsions of paraffin waxes (paraffins of petroleum, synthetic or vegetable origin).

In order to allow time for the operator to imprint the deactivating composition (D1) on part or all of a surface of the fresh hydraulic binder composition, it may be necessary to delay the setting. of the composition based on hydraulic binder and / or to increase its workability or open time.

In the context of the present invention, the term "open time" is understood to mean the time during which the composition based on hydraulic binder is manipulable, that is to say the time during which the spreading or settling of the cementitious composition is greater than 50% of the initial value, this value being measured by the slump height at the Abrams cone according to the French standard NF EN12350-2 (2012) or by the cone spreading of Abrams according to the NF standard EN12350-8 (2010).

The composition based on fresh hydraulic binder can thus advantageously have an open time of at least 30 minutes, preferably 30 minutes to 4 hours. The set retardation and / or the increase of its workability can be brought about by the use of a retarding and / or fluidifying additive in the composition based on fresh hydraulic binder. Thus, and advantageously, the composition based on fresh hydraulic binder may further comprise at least one retarding additive and / or fluidifying. The retarding and / or fluidifying additives may be any additive known to those skilled in the art and fulfilling this function.

In the context of the invention, the term "retarding additive" is understood to mean a compound having the effect of delaying the setting of the composition based on hydraulic binder, that is to say of delaying or inhibiting the phenomena related to this setting. such as phenomena of hydration, thereby inducing a later hardening of the composition. Such compounds are well known to those skilled in the art. In general, a retarding additive delays the setting time of a composition based on hydraulic binder in which it has been introduced at a dosage of at most 5% by dry weight relative to the weight of said hydraulic binder, the time of taken being measured according to test EN480-2 (2006). Preferably, setting time is delayed by at least 30 minutes with respect to a control hydraulic binder composition.

In the context of the invention the term "fluidizing additive", also called "water-reducing additive", an additive to reduce the amount of water required for the production of a composition based on hydraulic binder.

The retarding and / or fluidifying additive may be chosen from the family of comb-structure polymers, compounds comprising a polyalkoxylated chain and at least one amino-alkylene phosphonic group, gluconic acid, sugars, lignosulfonic acid, polynaphthalene sulfonic acid, polymelamine sulfonic acid and their salts, alone or in admixture.

The comb structure polymers are especially chosen from polycarboxylate main chain comb copolymers bearing grafted side chains of polyalkylene oxide (or PCP).

The compounds comprising a polyalkoxylated chain and at least one amino-alkylene phosphonic group may be chosen from the compounds of formula (I):

Rj

[R-O (R 1 -O) _n ] r _{+ q} [Q (-N /) _y ] (I) AA-P0 ₃ H ₂ in which:

R is a hydrogen atom or a monovalent hydrocarbon group having from 1 to 18 carbon atoms and optionally one or more heteroatoms;

the R, are similar or different from each other and represent an alkylene such as ethylene, propylene, butylene, amylene, octylene or cyclohexene, or an arylene such as styrene or methylstyrene, the R, optionally contain one or more heteroatoms;

Q is a hydrocarbon group having 2 to 18 carbon atoms and optionally one or more heteroatoms;

A is an alkylidene group having 1 to 5 carbon atoms;

the R _j are similar or different from each other and can be chosen from: the group A-P0 ₃ H ₂ , A having the abovementioned meaning,

the alkyl group comprising from 1 to 18 carbon atoms and capable of bearing [R-O (R 1 -O) _n ], R and R groups, having the abovementioned meanings,

and the group

-B-N

^ A-P0 ₃ H ₂

R _k denotes a group such that R _j , preferably R _k is selected from a group A-P0 ₃ H ₂ , A having the meaning mentioned above; and an alkyl group having from 1 to 18 carbon atoms and capable of bearing [R-O (R 1 -O) _n ], R and R groups, having the abovementioned meanings;

B denotes an alkylene group containing from 2 to 18 carbon atoms,

"n" is a number greater than or equal to 0,

"r" is the number of groups [R-0 (Ri-0) _n ] carried by the set of R ,,

"q" is the number of groups [R-0 (RiO) _n ] carried by Q, the sum

"r + q" is between 1 and 1 0,

"y" is an integer from 1 to 3,

Q, N and R _j may together form one or more rings, which ring (s) may further contain one or more other heteroatoms.

Particularly preferred is a polyalkoxylated polyphosphonate consisting of a water-soluble or water-dispersible organic compound having at least one amino-di- (alkylene-phosphonic) group and at least one polyoxyalkylated chain or at least one of its salts. In particular, the compounds of formula (I) in which R is a methyl group, the R, are ethylene and propylene groups, not being between 30 and 50, r + q is 1, Q is an ethylene group, A is a methylene group, y is 1 and R _j is CH2-PO ₃ H ₂ .

Such compounds are described in particular in application EP 0 663 892. Preferably, this compound is in particular contained in the product CHRYSO®Fluid Optima 100 available from CHRYSO.

A particular example of a retarding and / or fluidizing additive contained in the products CHRYSO®Fluid Optima 100 and CHRYSO®Fluid Optima 175 available from the company CHRYSO may be mentioned.

The sugars may be selected from glucose, fructose, sucrose, meritose, lactose, maltotriose, dextrose, maltose, galactose, mannose, glycogen, or a mixture thereof. The retarding and / or fluidizing additive may preferably be chosen from polycarboxylate main chain comb copolymers bearing polyalkyleneoxide (or PCP) grafted side chains or the compounds of formula (I), or their mixture.

Preferably, the content of retarding and / or fluidifying additive in the composition based on fresh hydraulic binder is from 0.2 to 3% by dry weight relative to the weight of fresh hydraulic binder.

After the deactivating composition (D1) has been imprinted on part or all of a surface of the fresh hydraulic binder composition, the process generally comprises a step of curing the fresh hydraulic binder composition. then a step of removing the surface uncured hydraulic binder layer. This last step makes it possible to reveal the aggregates on the surface of the composition based on hydraulic binder and to make the pattern appear. It is typically carried out by washing with water jet, generally under high pressure, or by brushing. The hardening step of the composition based on fresh hydraulic binder generally lasts from 8 to 24 hours.

According to a second alternative, the method comprises applying by printing an acid composition (A1) on part or all of a surface of a cured hydraulic binder composition.

The process according to the invention generally comprises, before the step of applying by printing the acid composition (A1) on the cured hydraulic binder-based composition, a step of shaping a composition based on fresh hydraulic binder, followed by a step of curing the fresh hydraulic binder composition to obtain the cured hydraulic binder composition. The shaping of the composition based on fresh hydraulic binder can be achieved by casting, floatation and if necessary, by vibration, or by 3D printing (by an additive manufacturing process).

Different levels of dig can be desired for a given pattern. Two embodiments of this second alternative of the method can be envisaged to obtain this effect.

According to a first embodiment, the method comprises the application by printing of an acid composition (A1) on part or all of a surface of a composition based on hardened hydraulic binder, then another printing application of the acid composition (A1) to a part of the surface on which the acid composition (A1) has been applied, this other application possibly being to be repeated. This first embodiment makes it possible to apply different amounts of acid composition (A1) to different parts of the surface of the cured hydraulic binder-based composition which it is desired to deactivate. Typically, successive passes of the printhead of the printer are performed on the part (s) of the surface for which a deeper hollow is desired. The greater the amount of acid composition (A1), the deeper the resulting hollow will be. Thus, to obtain a pattern with two levels of deactivation, the acid composition (A1) is applied once to a first part of the surface, and more than once (typically twice) to a second part of the surface. area. Similarly, to obtain a pattern with three levels of deactivation, for example, the acid composition (A1) is applied once to a first portion of the surface, twice to a second portion of the surface, and three times on a third part of the surface.

In this first embodiment, the method may comprise, between two successive applications of acid composition (A1), an accelerated drying step of the part of the surface on which the other application will be carried out. This drying can be carried out under UV or infrared light. It allows faster preparation and a sharper outline of the different levels of the pattern.

According to a second embodiment, the method comprises applying by printing an acid composition (A1) on part or all of a surface of a cured hydraulic binder composition, and then printing application of an acid composition (A2) to a portion or the entire surface of the cured hydraulic binder composition, it being understood that the acid compositions (A1) and (A2) have different hollow forces and are not applied to identical surfaces.

Of course, the fact that the acid compositions (A1) and (A2) are not applied to identical surfaces does not exclude that the surface on which the acid composition (A1) is applied is included in the surface on which the acid composition (A2) is applied, or vice versa. In addition, the fact that the acid compositions (A1) and (A2) are not applied to identical surfaces does not exclude that the acid compositions (A1) and (A2) are applied to surfaces overlapping. When they overlap, a pattern with three levels of deactivation will be obtained: a first part of the pattern with a first level of hollow on which only the acid composition (A1) has been applied, a second part of the pattern with a second a level of digestion on which only the acid composition (A2) has been applied, and a third part of the pattern with a third level of hollow on which the acid compositions (A1) and (A2) were applied.

Of course, as many different hollow force acid compositions can be used as desired. Thus, in one embodiment of this second embodiment, the method comprises applying by printing an acid composition (A1) on part or all of a surface of a composition based on hardened hydraulic binder, then applying by printing an acid composition (A2) on part or all of the surface of the cured hydraulic binder composition, and then applying by printing a composition of acid (A3) on part or all of the surface of the cured hydraulic binder composition, it being understood that the acid compositions (A1), (A2) and (A3) have off-axis forces different and are not applied to identical surfaces.

Typically, each acid composition (A1), (A2) and (A3) corresponds to the ink of an ink cartridge of the printer.

The acid compositions (A1), (A2) and (A3) comprise an acid. They may be in the form of a solution in an aqueous or oily solvent or in a petroleum fraction, or in the form of a dispersion in an aqueous or oily solvent or in a petroleum fraction, in particular in the form of a suspension or in the form of an emulsion. Advantageously, the acid compositions (A1), (A2) and optionally (A3) if an acid composition (A3) is used, have the same type of formulation (for example liquids, or water-in-oil emulsions). or oil-in-water emulsions) and / or comprise solvents of the same kind, for example water, or an oil of the same kind, or a petroleum cut. Typically, each acid composition (A1), (A2) and (A3) is an aqueous solution of one or more acids.

In the context of this disclosure, is meant by the term "acid" refer to a compound whose pK _a at 25 ° C is less than or equal to 6.

The acid can be an acid:

- Inorganic, preferably selected from hydrochloric acid (also called muriatic acid), sulfamic acid (HOSO ₂ NH ₂ ), phosphoric acid and nitric acid,

organic, preferably a carboxylic acid, an amino acid hydrochloride, preferably glycine hydrochloride (HOOC-CH ₂ -NH ₃ ⁺ , OI), or an alkylsulfonic acid, preferably methanesulfonic acid.

The acid may be a strong acid (hydrochloric acid, sulphamic acid, nitric acid, methanesulphonic acid) or weak (phosphoric acid, carboxylic acid, hydrochloride of glycine).

The acid composition may comprise a mixture of several acids.

The acid composition may comprise as glycine hydrochloride acid, for example, the composition consisting essentially of glycine hydrochloride as described in WO 2012/075091 A2.

The carboxylic acid may comprise a saturated or unsaturated carbon chain, preferably from 1 to 6 carbon atoms, for example from 1 to 3 (the carbon of the COOH of the carboxylic acid not being counted). It may comprise one, two or three carboxylic acid groups. The carboxylic acid may be a hydroxycarboxylic acid, which typically comprises one, two, three or more hydroxyl groups. Preferably, the pK _a (or a pK _{a thereof} ) of the carboxylic acid is from 2 to 6. It may especially be chosen from the group consisting of glycolic acid, citric acid and tartaric acid. , malic acid, lactic acid, acetic acid and mixtures thereof. Citric acid, tartaric acid and malic acid are preferred.

The acid composition (A1), (A2) or (A3) generally comprises from 1 to 50% by weight of acid. Typically, when an ink jet printer is used, the proportions of acid in the acid composition (A1), (A2) or (A3) are adapted so that the acid is in a proportion of 0, 1 to 500 g / m ² , preferably from 0.1 to 100 g / m ² , more preferably from 0.5 to 50 g / m ² relative to the jet section.

The acid compositions (A1), (A2) and (A3) have different hollow forces.

This different digging force can be achieved by using an identical acid in the acid compositions, but at a different concentration (generally, the higher the acid concentration in the acid composition, the higher its digging force is) . Typically, the lower the pH of the acid composition, the greater its digging force is important.

This different digging force can also be obtained by using acid compositions comprising acids of different natures and having different digging forces. Preferably, the acid compositions (A1), (A2) and optionally (A3) if an acid composition (A3) is used, then differ only in the nature of the acid, and possibly in the nature of the acids. possible additives. For example, a strong acid (A1) is used to carry out the part of the pattern with the deepest hollow and a weak acid (A2) to achieve the part of the pattern with the shallower hollow.

The acid compositions (A1), (A2) and / or (A3) may optionally contain additives making it possible to improve its properties chosen from fillers, opacifying agents, anti-foam agents, surfactants, biocides, thickeners, pigments, wetting agents (to improve the regularity of the application of the acid composition (A1) to the surface), plasticizers, film-forming agents, dispersants, viscosity control agents (in particular for net deposition of the droplet during printing, without spreading or retraction), antioxidants (especially to prevent acid decomposition, especially in case of forced local drying) or a mixture thereof.

In particular, the acid composition may comprise a viscosity regulating agent to control the rheological properties of the acid composition used so as to allow easy application by printing. Preferably, the acid composition (A1) and / or (A2) and / or (A3) has a Brookfield dynamic viscosity of less than 500 mPa.s measured at 20 ° C.

Preferably, these viscosity regulating agents are present in the acid composition at levels not exceeding 15% by weight, and preferably not exceeding 10% by weight.

In particular, the acid composition may include an antifoam agent to control the foam generated upon application of the acid. This antifoaming agent may be based on oil, siloxane, silicone or alkoxylated fatty alcohols.

After printing the acid composition (A1) on part or all of a surface of the cured hydraulic binder composition, the process generally comprises a step of rinsing the hydraulic binder composition hardened. Rinsing makes it possible to eliminate the acid and also the deposits of composition based on hydraulic binder which has been attacked on the surface, which makes apparent the aggregates on the surface of the composition based on hydraulic binder and thus the pattern. It is typically carried out by washing with water jet, preferably under high pressure. Generally, a few minutes are expected, typically between 5 and 60 minutes before rinsing so that the acid composition has time to attack the surface of the hydraulic binder composition.

As detailed above, whatever the alternative of the method used, the desired hollow can be obtained by adapting:

the diameter of the jet (or droplets) of the inkjet printer (the larger the diameter, the greater the amount of deactivating composition (D1) or acid (A1) applied, and the larger the hollow is important), and / or

the hollow force of the deactivating (D1) or acid (A1) composition, by adapting:

the nature of the surface-setting retarder in the deactivating composition (D1) or the nature of the acid in the acid composition (A1), and / or the concentration of the surface-setting retarder in the deactivating composition (D1) or the concentration of the acid in the acid composition (A1) (and therefore its pH).

The surface of the composition based on hydraulic binder may have different digs depending on the location. A hollow means for a given area of the surface of the composition based on hydraulic binder.

The patterns may in particular be created by making the aggregates (or some aggregates) of the hydraulic binder composition apparent. The amount of deactivating composition (D1) or acid (A1) applied and / or the hollow force of the deactivating composition (D1) or of acid (A1) are then adapted so that at least one of the hollow is smaller than the bottom dimension of the granulate of the hydraulic binder-based composition that is to be made apparent, wherein the lower dimension of the aggregate is measured by sieve size analysis.

The amount of deactivating composition (D1) or acid (A1) applied can be adapted by adapting the size of the jet / droplets of the printer and / or by making successive passes of the print head of the printer. printer as described above.

Indeed, if the hollow is greater than the size of the granulate of the composition based on hydraulic binder that it is desired to make apparent, the granulate off the hydraulic composition and is removed during rinsing, which is not wish. Typically, the amount of deactivating (D1) or acid (A1) composition applied and / or the digging force of the deactivating (D1) or acid (A1) composition are adapted so that at least one of hollow at least 2 times lower, in particular at least 5 times lower, for example at least 10 times lower than the lower dimension of the granulate of the composition based on hydraulic binder that is to be made apparent, where the dimension The bottom of the granulate is measured by sieve analysis.

By way of illustration, if it is desired to make a granulometric fraction of the aggregates of the composition based on hydraulic binder apparent, the desired hollow is smaller than the lower dimension of this granulometric fraction of the granules of the composition based on hydraulic binder, where the smaller size of the granulometric distribution of aggregates is measured by sieve analysis. Typically, the hollow is at least 2 times smaller, especially at least 5 times smaller, for example at least 10 times smaller than the smaller dimension of the finest aggregate of the composition based on hydraulic binder. For example, we want to make apparent aggregates larger than 1 mm of a composition based on hydraulic binder, prepared from the standardized sand of the company SNL. The particle size distribution of this sand where the diameters are measured by sieves is given in Table 1:

Table 1: Particle size distribution of standardized sand from SNL

In this example, a hollow less than or equal to 10 times 1 mm, or less than or equal to 100 μηι would therefore be particularly preferred.

Patterns can also be created by placing the hydraulic binder composition on a different color substrate.

In one embodiment, the hydraulic binder-based composition is on a substrate whose color is different from that of the hydraulic binder-based composition, and the amount of deactivating (D1) or acid (A1) composition. ) applied and / or the hollow force of the deactivating composition (D1) or acid (A1) are adapted so that at least one of the hollow is greater than or equal to the thickness of the composition based on hydraulic binder .

By "thickness of the hydraulic binder composition" is meant the distance between the surface of the substrate on which the binder composition is placed and the surface of the hydraulic binder composition.

When the hollow is greater than or equal to the thickness of the hydraulic binder composition, the hydraulic binder composition is removed in a localized manner throughout its thickness to the substrate. After rinsing, the surface portions to which the deactivating (D1) or acid (A1) composition has been applied form patterns whose color will be that of the substrate, while the remainder of the surface will be of the color of the composition based on hydraulic binder.

The substrate may in particular be a second composition based on hydraulic binder, the color of which is different from that of the composition based on hydraulic binder on which the deactivating composition (D1) or acid (A1) is applied. It is usual to introduce one or more pigments in a composition based on hydraulic binder to give it a desired color. For example, a dark gray concrete (as a substrate) can be coated with a light gray, fresh hydraulic binder-based composition to a thickness of 1 to 5 mm, and then applied by printing a deactivating composition ( D1) on a portion of the surface of the cool light gray hydraulic binder composition so that the hollow is greater than or equal to the thickness of the fresh hydraulic binder composition. After rinsing, the surface portions to which the deactivating composition (D1) has been applied will form dark gray patterns, while the remainder of the surface will be light gray.

It is sufficient that at least one of the hollow is greater than or equal to the thickness of the composition based on hydraulic binder. For example, one can have two different digs depending on the locations of the surface of the hydraulic binder composition:

in certain parts of the surface, a first hollow greater than or equal to the thickness of the composition based on hydraulic binder in order to make the substrate (and therefore its color) apparent, and

at other places on the surface, a second hollow less than the lower dimension of the granulate of the composition based on hydraulic binder which it is desired to make apparent (and therefore less than the thickness of the composition based on binder hydraulic), in order to make apparent the aggregates of the composition based on hydraulic binder.

Using the previous example in which is covered with a dark gray concrete (as a substrate) of a composition based on fresh hydraulic binder light gray color, with two different hollow according to the locations of the surface of the composition cool hydraulic binder:

in some parts of the surface, a first hollow greater than or equal to the thickness of the composition based on hydraulic binder makes apparent after rinsing dark gray patterns,

at other locations on the surface, a second hollow less than the lower dimension of the granulate of the composition based on hydraulic binder that is to be made apparent, makes it possible to form light gray patterns in which the aggregates of the composition based on hydraulic binder are apparent, - if there are other areas of the surface where no deactivating composition has been applied, the surface is light gray and the aggregates are not visible.

In one embodiment of the method, both alternatives are implemented one after the other. The process then comprises:

printing the application of a deactivating composition (D1) on part or all of a surface of a composition based on fresh hydraulic binder, then

the hardening of the composition based on fresh hydraulic binder, then

the elimination of the layer of uncured hydraulic binder at the surface and then

- The application by printing of an acid composition (A1) on part or all of the surface of a composition based on cured hydraulic binder.

The deactivating composition (D1) and the acid composition (A1) can be applied to the same or different surface parts.

Whatever the alternative of the method used, the composition based on hydraulic binder may undergo, before or during the creation of the pattern, all or part of its surface, an aesthetic treatment to protect it and / or to color it. It may for example, during the creation of the pattern, on all or part of the surface, undergo a mineralizing treatment (or hardener), in particular to induce coloring. It may also, after creating the pattern, on all or part of its surface, be covered with a protective product. The protective product is typically applied to the cured compositions for the purpose of protecting it, in particular from external aggression. Such products are known to those skilled in the art. The surface treated and / or covered may be both the surface of the areas intended to produce the pattern or the surface of the areas having the pattern, as the surrounding areas.

The surface may also, after creating the patterns undergo mechanical treatments known to those skilled in the art such as polishing, sandblasting ...

Claims

1. A method of patterning a surface of a hydraulic binder composition, comprising applying by printing a deactivating (D1) or acid (A1) composition to a part or all of a surface of a composition based on hydraulic binder.

2. - The method of claim 1, wherein the printing is performed by an ink jet printer whose print head expels droplets of deactivating composition (D1) or acid (A1).

3. A process according to any one of the preceding claims, wherein the surface of the hydraulic binder-based composition is not flat and the printing is carried out with a printer to control the location of the application of the disabling composition (D1) or acid (A1) in three dimensions.

4. A process according to any one of the preceding claims, wherein a deactivating composition (D1) is applied and the hydraulic binder composition is a fresh hydraulic binder based composition.

5. - Method according to claim 4, comprising a step of shaping the composition based on fresh hydraulic binder by a 3D printer, and a step of application by the 3D printer of the deactivating composition (D1) on a part of the surface of the composition based on fresh hydraulic binder.

6. A process according to any one of claims 4 to 5, comprising applying by printing a deactivating composition (D1) on part or all of a surface of a composition based on hydraulic binder. cool, and then another application by printing the deactivating composition (D1) on a part of the surface on which the deactivating composition (D1) has been applied, this other application possibly being repeated.

7. A process according to any one of claims 4 to 5, comprising applying by printing a deactivating composition (D1) on part or all of a surface of a composition based on hydraulic binder. cool, and then applying by printing a deactivating composition (D2) on part or all of the surface of the composition based on fresh hydraulic binder, it being understood that the deactivating compositions (D1) and (D2) ) have different digging forces and are not applied to identical surfaces.

8. - Process according to any one of claims 4 to 7, comprising after the step of applying by printing the deactivating composition (D1), a step of curing the composition based on fresh hydraulic binder, then a step removal of the surface uncured hydraulic binder layer, typically by high pressure water jet washing or brushing.

The process of any one of claims 1 to 3, wherein an acid composition (A1) is applied and the hydraulic binder composition is a cured hydraulic binder composition.

The method of claim 9, comprising applying by printing an acid composition (A1) to one or all of a surface of a cured hydraulic binder composition, and another printing application of the acid composition (A1) on a part of the surface on which the acid composition (A1) has been applied, this other application possibly being repeated.

1 1. A process according to claim 9, comprising applying by printing an acid composition (A1) on a part or all of a surface of a cured hydraulic binder composition, and then applying the printing an acid composition (A2) on part or all of the surface of the cured hydraulic binder composition, it being understood that the acid compositions (A1) and (A2) have hollow and are not applied to identical surfaces.

12. - Process according to any one of claims 9 to 1 1, comprising after the step of applying by printing of the acid composition (A1), a step of rinsing the composition based on cured hydraulic binder.

The process according to any one of the preceding claims, wherein the amount of deactivating (D1) or acid (A1) applied composition and / or the digging force of the deactivating (D1) composition or acid (A1) are adapted so that at least one of the digs is smaller than the bottom dimension of the granulate of the hydraulic binder-based composition that is to be made apparent, wherein the lower dimension of the granulate is measured by particle size analysis with sieves.

The method of any of the preceding claims, wherein the hydraulic binder composition is on a substrate whose color is different from that of the hydraulic binder composition, and the amount of deactivating composition. (D1) or acid (A1) applied and / or the hollow force of the deactivating composition (D1) or acid (A1) are adapted so that at least one of the hollow is greater than or equal to thickness of the composition based on hydraulic binder.

15. - Method according to one of the preceding claims, wherein the hydraulic binder comprises a cement.