The present invention relates to the field of dispersants and grinding aid agents for mineral matter, suitable respectively for improving the stability of the aqueous dispersions of mineral matter, and for facilitating the grinding of said mineral matter in aqueous suspension.
The invention relates primarily to the use, as dispersant and/or grinding aid agent for pigments and/or mineral fillers in aqueous suspension, of a water soluble polymer, with a controlled structure obtained by a controlled free radical polymerization method employing, as polymerization initiator, a particular alkoxyamine with the general formula (A):
where:
The invention further relates to methods for aqueous dispersing and for grinding of pigments and/or mineral fillers in aqueous suspensions, which put into practice this water soluble polymer.
The invention further relates to the aqueous dispersions and suspensions of pigments and/or mineral fillers thereby obtained.
The invention further relates to the use of the aqueous suspensions of pigments and/or mineral fillers thereby obtained in the paper field and in particular in the coating of the paper and the filling of the paper, or even in the fields of water based paints, plastics, cement, ceramics, detergents, cosmetics, and drilling muds.
The invention further relates to the paper formulations, water based paints, plastic compositions, cements, ceramic compositions, detergent compositions, cosmetic compositions, and the drilling muds thereby obtained.
The invention further relates to the direct use as a dispersant of said water soluble polymers in paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds.
It further relates to the paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds thereby obtained by direct use, as dispersant, of said water soluble polymers.
The manufacture, handling, transport and use of aqueous suspensions of mineral matter have always been operations in which the stability and the viscosity of these suspensions represent a crucial problem for a person skilled in the art, in order to avoid harmful mechanisms such as sedimentation, caking, pigment incompatibility or even problems of pumpability due to an excessively high viscosity.
Moreover, the person skilled in the art is also often led to perform a so-called grinding operation, which consists in reducing the size of the particles of pigments and/or mineral fillers via an input of energy, in order to adapt the particle size distribution of the particles to their intended application.
Thus, additives called “dispersants” have gradually been developed, suitable for improving the stability of said suspensions, as well as additives called “grinding aid agents” employed to facilitate the size reduction of the particles. These additives are generally based on acrylic and methacrylic polymers, as demonstrated by all the documents cited in the prior art relative to this application.
Numerous applied research projects and several patents have rapidly guided the person skilled in the art towards the choice of “controlled structure” polymers. We shall detail this concept through a number of examples and provide a precise meaning thereof, that will be used in the rest of this application.
In addition to the specific knowledge consisting of the synthesis of particular polymers, the person skilled in the art finds the following general teaching in U.S. Pat. No. 5,424,364: “controlled structure polymers” are effective dispersants for mineral fillers. Through a reading of this document, this expression must be interpreted as AB block polymers, to the detriment of polymers with a statistical architecture.
This concept is found in U.S. Pat. No. 5,231,131 which teaches the person skilled in the art that the purer these structured polymers, the more effective they are as dispersants: the privileged structure here is that of block or comb polymers, to the detriment of a random architecture.
Similarly, as regards the grinding methods, it appears in the document “Wetting and dispersing agents” (Chimia, 56, 2002, 170-176) that block copolymers can behave as very effective grinding aid agents for inorganic pigments used in paints and plastics.
In agreement with these documents, we shall therefore designate by “A method for obtaining a polymer with a controlled structure or architecture”, a method that enables the person skilled in the art to obtain a particular structure for the polymer that he wishes to prepare (such as block, comb, alternating, random, etc.).
By way of example, the person skilled in the art thus knows the documents WO 01/44388 and WO 01/44376 which describe a mineral dispersion containing water, a pigment, and a dispersant obtained by a controlled free radical polymerization method. The dispersant is a polymer having the structure of a comb with a hydrophobic skeleton and hydrophilic pendant groups. The two documents differ in the choice of the polymerization initiator: a compound containing a halide group (WO 01/44388) or a compound selected from the polyethers, polyesters, or polyurethanes (WO 01/44376).
As to the U.S. Pat. No. 4,656,226, it relates to a dispersant for pigments obtained by the GTP (Group Transfer Polymerization) technique, having a block structure of the type AB, where A is a segment consisting of polymerized methacrylic monomeric units and B is a segment consisting of polymerized methacrylic or acrylic monomeric units.
At this stage of the search, the aim of the person skilled in the art is therefore to obtain such polymers with a controlled architecture.
Pursuing his searches in this direction, the person skilled in the art then gains knowledge of the documents presenting the synthesis of controlled structure polymers, obtained by the ATRP (Atom Transfer Radical Polymerization) method. This technique has been extensively described in the document (Controlled Radical Polymerization, K. Matyjaszewski, Am. Chem. Soc., 1998, Chap16, pp 258).
Thus, the patent FR 2 797 633 describes a method for polymerizing acrylic and methacrylic monomers by ATRP. Similarly, “First example of the ATRP of an acidic monomer: direct synthesis of methacrylic acid copolymers in aqueous media” (Chem. Commun., 1999, 1285-1286) describes the use of this polymerization method applied to the synthesis of poly(ethylene oxide-sodium methacrylate) block copolymers.
Finally, document WO 00/40630 describes a composition containing an organic or inorganic pigment and a dispersant in the form of a block copolymer obtained by said technique.
However, all of these documents reveal new problems facing the person skilled in the art. On the one hand, the ATRP method employs catalysts based on copper salts which generate undesirable pollution; the copper is also found in the synthesized products, which is not necessarily the aim of the person skilled in the art. On the other hand, the ATRP method also involves amines that are often undesirable in the end product.
Faced with this serious drawback, the person skilled in the art accordingly turns to another polymerization method for obtaining controlled structures: the RAFT (Reversible Addition Fragmentation chain Transfer) technique. This technique has been extensively described in the document (Controlled/Living Radical Polymerization-Progress in ATRP, NMP, and RAFT, K. Matyjaszewski, Am. Chem. Soc., 2000, Chap20, pp 278).
In this field, the person skilled in the art knows the document WO 98/01478 which describes the synthesis of polymers of the block, graft or star type, employing a transfer agent of the R—C(═S)—S—R′ type.
At the same time, he knows the patent FR 2 821 620 which proposes a method of the RAFT type for polymerizing acrylic acid, employing a transfer agent of the R—X—C(═S)—S—R′ type. The polymer obtained can then be used as a dispersant or grinding aid agent in suspensions of mineral matter.
Yet a new problem, inherent in this polymerization technique, then appears: the use of sulfur bearing transfer agents. Apart from the drawback of being dangerous to the environment, these transfer agents impart a very unpleasant smell to the polymers obtained, and introduce not necessarily desirable organosulfur compounds into the end product.
To circumvent this new drawback, the person skilled in the art finally turns to the recent controlled free radical polymerization techniques, which employ nitroxides or alkoxyamines as polymerization initiators.
Thus the document WO 00/71501 teaches him that particular polyalkoxyaminees can be used to synthesize triblock copolymers in particular, each block being produced from monomers as different as alkyl acrylates and styrene derivatives, with excellent control of the polymerization and of the polydispersity index. However, this document does not reveal any particular use of said polymers.
Finally, the document WO 01/02345 teaches the person skilled in the art that polyalkoxyamines are suitable for obtaining controlled structure polymers such as block, comb, graft, or indeed random. These polymers have numerous applications as rheology modifiers or dispersants of mineral fillers in aqueous phase. However, this patent application reveals a serious drawback as regards the industrial manufacture of polymers. While it states in the text that the splitting of the O—C bond of the alkoxyamine selected takes place between 50 and 160° C. (page 35), it clearly appears in the examples that the operations must be conducted at temperatures substantially above 100° C. in order to be effective.
As demonstrated by examples C1 to C9 (pages 57 to 59) on the polymerization of butyl acrylate, the reaction must be carried out at 145° C. for 3 hours. In fact, in order to work in aqueous phase, as desired by the person skilled in the art to respect the environment, such temperatures make the polymerization method at atmospheric pressure impossible. Moreover, the fact of having to work at a such high temperatures is a prohibitive drawback for the synthesis of dispersants and grinding aid agents from acrylic compounds; this is because at such temperatures, operations take place near or indeed above the boiling points of the monomers used, these boiling points being 145° C., 141° C. and 161° C. respectively for butyl acrylate, acrylic acid and methacrylic acid.
Furthermore, at such temperatures, thermal initiation mechanisms occur, generating uncontrolled chains and commensurately degrinding the controlled architecture.
Pursuing his researches, the Applicant has surprisingly found the solution to the problem of obtaining stable aqueous suspensions of mineral matter employing controlled structure polymers presenting neither the pollution problems of the polymers produced by the use of copper based compounds, nor the problems of smell of the polymers obtained by the use of sulfur based compounds, nor the problems of pollution incurred by the incorporation of organosulfur compounds.
Thus the Applicant has surprisingly found that water soluble polymers with a controlled structure obtained by a controlled free radical polymerization method, at low temperature, that is at a temperature below the boiling point of the monomers employed and of water, are suitable for obtaining polymers used very effectively as dispersants and/or grinding aid agents for pigments and/or mineral fillers in aqueous suspension.
This polymerization method employs, as a polymerization initiator, a particular alkoxyamine with the general formula (A):
where:
The polymers thus obtained by the method present the advantage of not containing compounds based on copper salts contrary to the polymers obtained by ATRP, and of not containing sulfur compounds as opposed to the products obtained by the RAFT technique, while having an architecture controllable via their polymerization method.
The finished products obtained are also polymers usable upon completion of the polymerization reaction directly resulting from this polymerization without any need to carry out post-treatment reactions after polymerization such as filtration, precipitation or other, reactions that change the conformation of the resulting polymer.
The object of the invention is therefore the use, as dispersant and/or grinding aid agent for pigments and/or mineral fillers in aqueous suspension, of a water soluble polymer with a controlled structure obtained by a controlled free radical polymerization method employing, as a polymerization initiator, a particular alkoxyamine with the general formula (A).
A further object of the invention resides in the aqueous dispersions and suspensions of pigments and/or mineral fillers thereby obtained.
A further object of the invention is the use of the aqueous dispersions and suspensions of pigments and/or mineral fillers thereby obtained in the paper field such as in particular the coating that employs a formulation of coating colours and the filling in the manufacture of paper sheets, water based paints, plastics, cements, ceramics, detergents, cosmetics, and drilling muds.
A further object of the invention is the paper formulations, water based paints, plastic compositions, cements, ceramic compositions, detergent compositions, cosmetic compositions, and drilling muds thereby obtained.
A further object of the invention is the direct use of said water soluble homopolymers and/or copolymers in the paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions, and drilling muds, as a dispersant.
A final object of the invention resides in the paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions, and drilling muds, obtained by the direct use of said polymers as a dispersant.
The use of said water soluble polymers according to the invention therefore makes it possible to obtain stable aqueous dispersions of pigments and/or mineral fillers and finely ground aqueous suspensions of pigments and/or mineral fillers.
These aqueous dispersions and suspensions of pigments and/or mineral fillers are suitable for obtaining paper formulations, water based paints, plastic compositions, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds, the viscosity of which can be controlled according to the final intended application.
Finally, the direct use of said water soluble polymers is suitable for obtaining paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds, the viscosity of which can also be regulated according to the final intended application.
These objectives are achieved thanks to the use of a water soluble polymer according to the invention, which is characterized in that said polymer has a controlled structure and is obtained by a controlled free radical polymerization method that employs, as a polymerization initiator, a particular alkoxyamine with the general formula (A).
The use of a water soluble polymer according to the invention is further characterized in that the water soluble polymer is obtained by a controlled free radical polymerization method, involving the particular alkoxyamine previously described, of monomers selected from:
In a particular manner, the use of a water soluble polymer according to the invention is further characterized in that said water soluble polymer is obtained by the controlled free radical polymerization of monomers selected from:
R-A-Si(OB)3
More particularly the use of a water soluble monomer according to the invention is characterized in that said polymer consists of, expressed by weight:
R-A-Si(OB)3
Finally, the use of a water soluble polymer according to the invention is characterized in that said polymer is a water soluble copolymer and has a random, block, comb, graft, or alternating type of structure.
Depending on its use, the person skilled in the art will know how to adjust the molecular weight of the polymer employed according to the invention.
This molecular weight is determined by the GPC (Gel Permeability Chromatography) method using a Waters™ liquid chromatograph equipped with two detectors of which one combines the dynamic diffusion of light with viscometry measured by a Viscotek™ viscometer and the other is a Waters™ refractometric concentration detector.
This liquid chromatograph is equipped with steric hindrance columns suitably selected by the person skilled in the art in order to separate the different molecular weights of the polymers analyzed.
The liquid elution phase is an aqueous phase.
A further object of the invention resides in the dispersants and/or grinding aid agents for mineral matter in aqueous suspension.
Thus the dispersant of mineral matter in aqueous suspension according to the invention is characterized in that the polymer is a water soluble polymer having a controlled structure and obtained by a controlled free radical polymerization method employing, as a polymerization initiator, an alkoxyamine with the general formula (A) previously defined.
It is preferably characterized in that the water soluble polymer is obtained by the controlled free radical polymerization of monomers selected from the monomers previously discussed.
Another particular manner consists in that the dispersant according to the invention is characterized in that it is a water soluble copolymer and in that it has a random, block, comb, graft or alternating structure.
Similarly, the grinding aid agent for mineral matter according to the invention is characterized in that the polymer is a water soluble polymer having a controlled structure and obtained by a controlled free radical polymerization method employing, as a polymerization initiator, an alkoxyamine with the general formula (A) previously defined.
It is preferably characterized in that the water soluble polymer is obtained by the controlled free radical polymerization of monomers selected from the monomers previously discussed.
Another particular manner consists in that the dispersant according to the invention is characterized in that it is a water soluble copolymer and in that is has a random, block, comb, graft, or alternating structure.
A further object of the invention resides in the method for dispersing and the method for grinding mineral matter in aqueous suspension.
The method for dispersing mineral matter according to the invention is characterized in that the water soluble polymer according to the invention is used and particularly in that 0.05% to 5% by dry weight of said polymer is used with respect to the dry weight of pigment and/or mineral filler, and very preferably between 0.1% and 3% of said polymer with respect to the dry weight of pigment and/or mineral filler.
The method for grinding mineral matter according to the invention is characterized in that the water soluble polymer according to the invention is used and particularly in that 0.05% to 5% by dry weight of said polymer is used with respect to the dry weight of pigment and/or mineral filler, and very preferably between 0.1% and 3% of said polymer with respect to the dry weight of pigment and/or mineral filler.
Finally, a further object of the invention resides in the aqueous dispersions and suspensions of pigments and/or mineral fillers obtained thanks to the use of the above water soluble polymer according to the invention.
These aqueous dispersions of mineral matter are characterized in that they contain a pigment and/or a mineral filler selected from natural or synthetic calcium carbonate, dolomites, kaolonite, talc, gypsum, lime, magnesia, titanium oxide, satin white, aluminum trioxide or even aluminum trihydroxide, silicas, mica and the mixture of these fillers together, such as the talc-calcium carbonate, calcium carbonate-kaolinite mixtures, or even mixtures of calcium carbonate with aluminum trihydroxide or aluminum trioxide, or even mixtures with synthetic or natural fibers or even co-structures of minerals such as the talc-calcium carbonate or talc-titanium dioxide co-structures or mixtures thereof.
These aqueous suspensions of mineral matter are characterized in that they contain a pigment and/or a mineral filler selected from natural or synthetic calcium carbonate, dolomites, kaolonite, talc, gypsum, lime, magnesia, titanium oxide, satin white, aluminum trioxide or even aluminum trihydroxide, silicas, mica and the mixture of these fillers together, such as the talc-calcium carbonate, calcium carbonate-kaolinite mixtures, or even mixtures of calcium carbonate with aluminum trihydroxide or aluminum trioxide, or even mixtures with synthetic or natural fibers or even co-structures of minerals such as the talc-calcium carbonate or talc-titanium dioxide co-structures or mixtures thereof.
The aqueous dispersions according to the invention are characterized in that they contain in a particular manner natural or synthetic calcium carbonate or cement and more particularly a natural calcium carbonate selected from marble, calcite, chalk or mixtures thereof.
The aqueous suspensions according to the invention are characterized in that they contain in a particular manner natural or synthetic calcium carbonate and more particularly a natural calcium carbonate selected from marble, calcite, chalk or mixtures thereof.
Finally, the above aqueous suspensions and dispersions are characterized in that they contain 0.05 to 5% by dry weight of the water soluble polymer used according to the invention with respect to the dry weight of the pigments and/or mineral fillers, and in that they contain more particularly 0.1 to 3% by dry weight of the water soluble polymer used according to the invention with respect to the dry weight of the pigment and/or mineral fillers.
A further object of the invention is the use of the aqueous dispersions and suspensions of pigments and/or mineral fillers thus obtained in the paper field such as in particular the coating of the paper putting into practice a formulation of coating colours and the filling of the paper in the manufacture of paper sheets, water based paints, plastics, cement, ceramics, detergents, drilling muds.
A further object of the invention is a method for dispersing mineral matter in a paper formulation, in a water based paint, in a cement, in a ceramic composition, in a detergent composition, in a drilling mud. This method is accordingly characterized in that the water soluble polymer according to the invention is used directly as dispersant.
A further object of the invention resides in the paper formulations, water based paints, plastic composition, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds obtained from said above aqueous dispersions and suspensions of pigments and/or mineral fillers.
A further object of the invention is the direct use of the polymer according to the invention as dispersant in the paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds.
A final object of the invention resides in the paper formulations, water based paints, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds thus obtained.
Regardless of the method for obtaining them (using the aqueous dispersions and/or suspensions of mineral matter made with said polymer and/or said copolymer, or by direct introduction of said polymer and/or said copolymer in the formulations concerned) the paper formulations, water based paints, plastic compositions, cements, ceramic compositions, detergent compositions, cosmetic compositions and drilling muds, are characterized in that they contain 0.01% to 5% by dry weights of said water soluble polymer.
The scope and advantages of the invention will be better understood from the following examples which are non-limiting.
This example illustrates the obtaining of water soluble polymers put into practice according to the invention.
The following are introduced into a 1 liter glass reactor equipped with mechanical stirring and an oil bath type of heating system:
The medium is heated to 55° C. and a solution is introduced in one step consisting of 25 g of ethanol and 2.92 g of the following alkoxyamine:
The mixture is heated for 2 hours with stirring at 60° C. and the ethanol is distilled. The medium is neutralized to pH 7 with 50% caustic soda solution.
A clear aqueous solution is obtained containing 37% of dry matter of a polymer consisting by weight of:
The following are introduced into a 1 liter glass reactor equipped with mechanical stirring and an oil bath type of heating system:
The medium is heated to 65° C. and a solution is introduced in one step consisting of 25 g of ethanol and 2.92 g of the following alkoxyamine:
The mixture is heated for 2 hours with stirring at 70° C. and the ethanol is distilled. The medium is neutralized to pH 7 with 50% caustic soda solution.
A clear aqueous solution is obtained containing 36% of dry matter of a polymer consisting by weight of:
The following are introduced into a 1 liter glass reactor equipped with mechanical stirring and an oil bath type of heating system:
The medium is heated to 65° C. and a solution is introduced in one step consisting of 25 g of ethanol and 2.92 g of the following alkoxyamine:
The mixture is heated for 2 hours with stirring at 70° C. and the ethanol is distilled. The medium is neutralized to pH 7 with 50% caustic soda solution.
A clear aqueous solution is obtained containing 39% of dry matter of a polymer consisting by weight of:
The following are introduced into a 1 liter glass reactor equipped with mechanical stirring and an oil bath type of heating system:
The medium is heated to 65° C. and a solution is introduced in one step consisting of 25 g of ethanol and 2.92 g of the following alkoxyamine:
The mixture is heated for 2 hours with stirring at 70° C. and the ethanol is distilled. The medium is neutralized to pH 7 with 50% caustic soda solution.
A clear aqueous solution is obtained containing 40% of dry matter of a polymer consisting by weight of:
This example illustrates the putting into practice of the polymers obtained according to the invention as a grinding aid for mineral matter and more particularly for calcium carbonate. This example also illustrates the obtaining of an aqueous suspension of calcium carbonate according to the invention.
It should also be noted that these suspensions of calcium carbonate according to the invention are refined, strongly concentrated in mineral matter and easy to handle by the end user that is easily usable for paper coating and for paper filling.
This test, which illustrates the invention, puts into practice 1.2% by dry weight of the polymer of test No. 1, with respect to the dry weight of calcium carbonate.
This test, which illustrates the invention, puts into practice 1.2% by dry weight of the polymer of test No. 2, with respect to the dry weight of calcium carbonate.
This test, which illustrates the invention, puts into practice 1.2% by dry weight of the polymer of test No. 3, with respect to the dry weight of calcium carbonate.
This test, which illustrates the invention, puts into practice 1.2% by dry weight of the polymer of test No. 4, with respect to the dry weight of calcium carbonate.
For each test, an aqueous suspension was prepared using calcium carbonate from the Orgon deposit (France), with an average particle diameter of about 50 microns.
The aqueous suspension has a dry matter concentration of 78% by weight with respect to the total weight.
The grinding aid agent is introduced into this suspension according to the indicated quantities, expressed as percent by dry weight with respect to the weight of dry calcium carbonate to be ground.
The suspension circulates in a Dyno-Mill™ type of grinder with a fixed cylinder and a rotating impeller, of which the grinding material consists of corundum beads between 0.6 millimeter and 1.0 millimeter in diameter.
The total occupied by the grinding material is 1150 cubic centimeters whereas its weight is 2900 g.
The grinding chamber has a volume of 1400 cubic centimeters. The circumferential speed of the grinder is 10 meters per second.
The calcium carbonate suspension is recycled at the rate of 18 liters per hour.
The outlet of the Dyno-Mill™ grinder is equipped with a 200 micron mesh separator to separate the suspension produced by the grinding from the grinding material.
The temperature during each grinding test is kept at about 60° C.
At the end of grinding (To), a sample of the pigment suspension is recovered in a bottle. The particle size distribution of this suspension (% of particles under one micron) is measured using a Sedigraph™ 5100 granulometer manufactured by Micromeritics.
The Brookfield™ viscosity of the suspensions is measured using an RVT type Brookfield™ viscometer, at a temperature of 20° C. and speeds of rotation of 10 rpm and 100 rpm with the appropriate mobile element. The results represent the viscosity values at t=0.
After being left to rest for 8 days in the bottle, the bottle is shaken and the viscosity of the suspension is measured by introducing the appropriate spindle of the RVT type Brookfield™ viscometer into the bottle, at a temperature of 20° C. and speeds of rotation of 10 rpm and 100 rpm.
These viscosity measurements represents the APAG viscosity results at t=8 days after stirring.
All this experimental results are given in Table 1 below, which also indicates the consumption in percentage by weight of grinding aid agent used to obtain the indicated particle size distribution
A reading of the results of Table 1 shows that the polymers according to the invention can be used as grinding aids for mineral matter in aqueous suspension, and in particular natural calcium carbonate, and that it is also possible to obtain aqueous suspensions of natural calcium carbonate containing the polymer according to the invention.
This example concerns the demonstration of the use of the polymers according to the invention as cement dispersants. This example also illustrates the obtaining of the aqueous suspension of cement according to the invention.
For this purpose, for each of the tests of the example, the various components of the standard grout are poured into a grout mixer (EN 196-1) in the On position, with a real constant volume of 1 m3 per 450 kg of cement and of constant workability equal to 2 seconds measured on the Perrier worksite grout workability meter defined by standard NFP 18452.
For this purpose, the following are weighed in the bowl of the mixer:
After the end of the addition of these various components, the mixer is maintained at high speed for 30 seconds and then stopped for 90 seconds to scrape the walls of the mixer.
Once the grout adhering to the walls has been completely scraped off, the mixing is resumed for one minute at high speed.
Compliance with these time intervals enables us to obtain a mixing cycle that lasts 4 minutes and conforms to standard EN 196-1.
This test illustrates the control and puts into practice a cement formulation without additive.
This test illustrates the prior art and puts into practice a naphthalene sulfonate sold by Scheppens.
This test, which illustrates the invention, puts into practice the polymer of test No. 1.
This test, which illustrates the invention, puts into practice the polymer of test No. 3.
This test, which illustrates the invention, puts into practice the polymer of test No. 4.
This test, which illustrates the invention, puts into practice the polymer of test No. 2.
The quantities of components being adjusted for each of the grouts of the various tests in order to operate at a constant real volume (1 m3 per 450 kg of cement) and constant workability (2 seconds), the polymer put into practice is even more effective with less water and more sand.
The results obtained for the different tests are given in Table 2 below.
A reading of the table reveals the improvement provided by the use of the copolymers according to the invention as cement dispersants.
This example concerns the use of the polymers according to the invention in the field of ceramics.
For this purpose, the dispersant efficiency is evaluated of the polymers according to the invention contained in the aqueous suspensions of clay according to the invention put into practice in the field of ceramics.
For this purpose, and for each of the tests Nos. 16 to 19, 250 grams of raw water and 0.65 grams of dispersant to be tested are weighed in a 500 milliliter plastic beaker fitted with a stirring rod 60 mm in diameter.
After stirring the mixture contained in the beaker, 217.3 g of Fuchs-Ton clay for slurry, is poured in, in order to obtain a dry matter concentration of 46.5% and a test dispersant content of 0.3% by dry weight with respect to the dry weight of clay.
After 20 minutes of stirring at a speed of 750 rpm, the viscosity of the slurry is measured by measuring the RVT type Brookfield™ viscosity at 10 rpm and 100 rpm.
The various tests are as follows:
This test is a control and uses no dispersant.
The Brookfield™ viscosities obtained are 6400 mPa·s at 10 rpm and 870 mPa·s at 100 rpm.
This test illustrates the invention and puts into practice the polymer according to the invention of test No. 1.
The Brookfield™ viscosities obtained are 6000 mPa·s at 10 rpm and 800 mPa·s at 100 rpm.
This test illustrates the invention and puts into practice the polymer according to the invention of test No. 4.
The Brookfield™ viscosities obtained are 6000 mPa·s at 10 rpm and 800 mPa·s at 100 rpm.
This test illustrates the invention and puts into practice the polymer according to the invention of test No. 2.
The Brookfield™ viscosities obtained are 6000 mPa·s at 10 rpm and 800 mPa·s at 100 rpm.
This test illustrates the invention and puts into practice the polymer according to the invention of test No. 3.
The Brookfield™ viscosities obtained are 6000 mPa·s at 10 rpm and 800 mPa·s at 100 rpm.
A reading of the results of the various tests shows that the use of the polymers in the field of ceramics is feasible.
Number | Date | Country | Kind |
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0315385 | Dec 2003 | FR | national |
Number | Date | Country | |
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Parent | 10584147 | Jun 2006 | US |
Child | 12938682 | US |