EP0422997A1 - Stable aqueous zeolite suspensions containing a succinoglycane - Google Patents

Abstract

Stable aqueous zeolite suspensions. …<??>According to the invention, these suspensions include a succinoglycan. …<??>They may additionally include a dispersant chosen from siliconates and silicone resins. …<??>These suspensions can be employed more particularly in the preparation of detergent compositions.

Description

The present invention relates to stable aqueous suspensions of zeolites.

The use of zeolites in detergency is well known. This use has developed in particular as a result of the at least partial substitution of zeolites for phosphates in detergents. They have been criticized, in fact, for causing eutrophication of the waters and therefore for posing ecological problems.

Zeolites are generally used in the form of aqueous suspensions or slurries which can for example be introduced into detergent slurries which can then be atomized.

However, these zeolite suspensions tend to sediment or gel, which makes them difficult to transport or store. We observe, in fact, very often at the end of transport or after a more or less long storage period the deposition of a hard layer of pigment topped with a more fluid slurry but poor in dry matter.

In addition, it is generally impossible to resuspend the zeolite or to obtain a slurry having a viscosity low enough to be pumpable and therefore usable industrially. So there is a very real problem there.

The main object of the invention is therefore a means of obtaining an aqueous suspension of zeolite which is stable, that is to say which no longer sediments or only very shortly after several days of storage.

A second object of the invention is a means of obtaining an aqueous suspension of zeolite which is not only stable, but which, moreover, is pumpable, that is to say which has a viscosity suitable for industrial use.

For this purpose, the suspensions according to the invention comprise zeolites and they are characterized in that they also comprise a succinoglycan.

Furthermore, according to a particular embodiment of the invention, the aqueous suspensions of zeolites further comprise a dispersant which is a siliconate and / or one of its derivatives.

Finally, according to another embodiment of the invention, the aqueous suspensions of zeolites further comprise a dispersant which is a silicone resin.

Other characteristics and details of the invention will be better understood on reading the description which follows and concrete but nonlimiting examples given below.

The zeolites used in the context of the present invention include crystalline, amorphous and mixed crystalline-amorphous, natural or synthetic zeolites.

Of course, preferably those capable of reacting quickly enough with the calcium and / or magnesium ions will be chosen so as to be able to soften the washing waters.

Generally, finely divided zeolites are used having an average diameter of primary particles of between 0.1 and 10 μm and, advantageously, between 0.5 and 5 μm, as well as a theoretical cation exchange power greater than 100 mg of CaCO₃ / g of anhydrous product and preferably greater than 200 mg.

Use is also more particularly made of zeolites of type A, X or Y and in particular 4A and 13X.

By way of example of zeolites which can be used in the context of the present invention, mention may be made of the products which are the subject of French patent applications n ° 2 225 568, 2 269 575, 2 283 220 whose teaching incorporated here.

Mention may more particularly be made of the zeolites obtained by the processes described in the French patent applications in the name of the Applicant No. 2,376,074, 2,384,716, 2,392,932, 2,528,722, the teaching of which is also incorporated herein request. The last reference cited refers in particular to zeolites having a speed constant, related to the surface of the zeolites per liter of solution greater than 0.15 s⁻¹.lm⁻², preferably greater than 0.25 and advantageously between 0.4 and 4 s⁻¹.lm⁻². These zeolites have particularly advantageous qualities in the use in detergency.

Application No. 2,392,932 in particular mentions zeolites obtained by a process consisting in injecting a sodium silicate solution in the axis of a venturi while a sodium aluminate solution is injected coaxially with the same venturi with recycling of the mixture obtained.

In particular, zeolites of the formula are obtained:
x Na₂O, y Al₂O₃, zSiO₂, wH₂O
in which if y = 1, x = 1, z = 1.8 to 2, w = 0 to 5 and having a particle size corresponding to the following distribution in number 95% <10µm, 99% <15µm, 50% between 2 and 6µm for the average diameter.

The suspensions may have a variable zeolite concentration depending on the application. In detergency, this concentration is generally between 40 and 51% by weight.

The pH of the suspensions is also a function of their use. Still in the detergency application, this pH expressed at 1% by weight of dry zeolite is approximately 11.

According to the main characteristic of the invention, a succinoglycan is used as a stabilizing agent for zeolite suspensions.

Thanks to this stabilizing agent, suspensions are obtained which after several days of storage do not settle or which at most have a slight sediment which is easy to resuspend.

A succinoglycan is a polysaccharide containing succinic acid and galactose and glucose as sugars.

The succinoglycans are generally obtained by fermentation of a medium comprising at least one carbon source assimilable by a strain or a recombinant or a mutant of this strain of the type given below:
- Pseudomonas, in particular of origin NCIB 11592
- Rhizobium meliloti, in particular of origin U-27, 1021, SU-27, SU-4, SU-231, SU-255, SU-256, K 24 (R 13), A 148 (R 15), J 7017
- Rhizobium trifolii, in particular of origin J-60W
- Alcaligenes faecalis of myxogenic varieties, in particular of origin 10C3,22-33
- Agrobacterium radiobacter, in particular of origin IFO 13533
- Agrobacterium rhizogenes, in particular of IFO 13259 origin
- Agrobacterium tumefaciens, in particular of origin IFO 3058, A-8, A-10.

Preferably, a succinoglycan is chosen from the group of those which, after having passed the transition temperature, have an intrinsic viscosity of at least 14,000 ml / g and more particularly of at least 15,000 ml / q.

This intrinsic viscosity is determined by the extrapolation at zero concentration of the reduced specific viscosity curve.

In the context of the present invention, a very interesting family of products has turned out to be that comprising the succinoglycans obtained from an Agrobacterium tumefaciens I-736 strain, one of its recombinants or one of its mutants.

The so-called Agrobacterium tumefaciens strain was deposited in accordance with the Budapest Treaty with the National Collection of Culture of Microorganisms (CNCM), on March 1, 1988, where it is publicly accessible under number 1736. This strain comes from the National Collection of Phytophathogenic Bacteria and is listed under number CNBP 291 in the 1974 catalog of the curator.

The pure culture of Agrobacterium tumefaciens I-736 can be carried out in an inclined agar tube (slant) incubated at a temperature between 26 and 32 ° C, and more generally between 28 and 32 ° C.

At these temperatures, and in particular on media based on MY agar and Bennett agar, the compositions of which are indicated below, it has been possible to observe the formation of a bacterial mucoid mat covering the entire slant from 20 hours.

The following maintenance media were considered particularly advantageous for the cultivation of Agrobacterium tumefaciens I-736: - MY Agar medium (in g / l) Soy-Peptones 5 Yeast extract 3 Malt extract 3 Glucose 10 Agar 20 - TGY Agar medium (produced by the Pasteur Institute (in g / l) Peptones 5 Yeast extract 2.5 Glucose 1 Agar 20 - Middle Bennett Agar (in g / l) Peptones 1 Meat extract 1 NZ Amine A ^R 2 (Produced by Sheffield Chemical Co.) Glucose 10 Agar 20 - TS Agar medium (produced by Sté Bio Mérieux) (in g / l) Bio trypcase 17 Bio soyase 3 K₂HPO₄ 2.5 NaCl 5 Glucose 2.5 Agar 20

The Agrobacterium tumefaciens I-736 strain can also be cultivated in a Petri dish, for example on MY agar or TGY agar medium.
Under these conditions, the colonies are visible from 24 to 30 hours, and have the following characteristics, at 48 hours:
- cut ; 2 to 3 mm in diameter
- smooth and slightly curved appearance
- very light brown-yellow color
- colonies with a clear edge and less mucoid on a Petri dish than on a slant.

The Agrobacterium tumefaciens I-736 strain can use the following sugars:
- glucose
- sucrose
- starch hydrolysates
and optionally native starch and lactose.

Glucose and sucrose are preferred sugars.

It has been possible to demonstrate that, in general, the succinoglycan obtained from this strain comprises units derived from glucose, galactose and pyruvic, succinic and acetic acids or salts of these acids, generally in proportions molars respectively of 5-8 / 1-2 / 0.5-2 / 0.5-2 / 0.05-2 preferably of 6 -7.5 / 1 - 1.5 / 0.5 - 1/0 , 5 - 1 / 0.05-0.2 and more preferably still from 7/1 / 0.5 - 1 / 0.5 - 1 / 0.05 - 0.1.

Said pyruvic, succinic and acetic acids are generally in the form of salts such as sodium, potassium, calcium or ammonium salts.

The methods of analysis of succinoglycan which have made it possible to determine its crude formula as specified above, have as a principle the determination of the constituent elements (sugars and acids) after hydrolysis of said succinoglycan and chromatographic assays by internal or external calibration.

Thus, the dosage of sugars was carried out as follows:
100 mg of succinoglycan are hydrolyzed in hermetic tubes with 5 ml of molar trifluoroacetic acid at 105 ° C for three to six hours.

This is followed by dry evaporation and taking up the dry residue in 5 ml of pyridine containing 15 mg of sorbitol as an internal standard; then silylation on 1 ml of pyridine solution with 0.9 ml of hexamethyldisilazane. The silylation is catalyzed with 0.1 ml of trifluoroacetic acid.

The sugar dosage is then carried out by gas chromatography with F.I.D detection, on a capillary glass column 25 m long and 0.25 mm in diameter, loaded with methylsilicone phase having a film thickness of 0.14 μ. The carrier gas used is hydrogen, with a flow rate of 2 ml / minute.

The dosage of pyruvic acid is carried out from a stock solution obtained by hydrolysis of 80 mg of succinoglycan using 5 ml of 4N hydrochloric acid for 1 hour at 105 ° C., then addition of 2 mg of acid ketoglutaric (constituting the internal standard) and adjustment to 25 ml by distilled water.

The assay is then carried out by High Performance Liquid Chromatography (HPLC) using a column loaded with C₁₈ grafted silica of 5 μ in diameter, the length of which is 250 mm and the diameter of 4.6 mm. The eluent used is a 50/50 mixture by volume of 0.02 M phosphoric acid and acetonitrile. The flow rate is 1.5 ml / minute.

The detection of pyruvic acid is done by Ultraviolet at 375 nm.

The determination of succinic acid is carried out after hydrolysis of the succinoglycan under the same conditions as those used for the determination of pyruvic acid. The assay is direct, by external calibration. The standard succinic acid solution used contains 8 mg of succinic acid in 25 ml of water.

The HPLC technique is again used on Aminex HPX87H ^R columns from BIORAD ^R. The eluent is 0.01 N sulfuric acid, and the flow rate is 0.8 ml / minute. The detection of succinic acid is refractometric.

The dosage of acetic acid is carried out after hydrolysis of 300 to 350 mg of succinoglycan with 5 ml of 4 N trifluoroacetic acid at 120 ° C for three hours. Then 30 mg of propionic acid is added as an internal standard and assayed by gas chromatography with FID detection

For the assay, a glass column 2 m long and 3 mm in diameter is used, filled with 5% FFAP phase and 1% phosphoric acid absorbed on chromosorb G ^R (AW DMCS) from 80 to 100 mesh. . The carrier gas is helium with a flow rate of 30 ml / minute.

The succinoglycans of the family described above generally also have the following properties:

1. Their intrinsic viscosity is between 3000 and 25000 ml / g and more particularly between 14000 and 25000 ml / g and preferably between 15000 and 24000 ml / g.

formule dans laquelle :
- η est la viscosité de la solution au plateau Newtonien
- ηo est la viscosité du solvant
et - C est la concentration en succinoglycane,
en utilisant l'équation du Huggins ;

k′ étant la constante de Huggins au 1er plateau NewtonienThe intrinsic viscosity (η) as specified is determined by extrapolation at zero concentration of the reduced viscosity

formula in which:
- η is the viscosity of the solution on the Newtonian plateau
- ηo is the viscosity of the solvent
and - C is the succinoglycan concentration,
using the Huggins equation;

k ′ being Huggins constant on the 1st Newtonian plateau

est mesurée de la façon suivante :The specific viscosity

is measured as follows:

A stock solution of 0.2 g / l of succinoglycan is prepared in a 0.1 M NaCl aqueous solution.

We then prepare a range of solutions including succinoglycan at concentrations between 0.03 and 0.1 g / l by dilution of the mother solution with the 0.1 M Nacl aqueous solution.

The measurements are then carried out at 23 ° C. using a LOW SHEAR viscometer.

The specific viscosity curve is plotted as a function of the concentration and extrapolated to zero concentration.

2. The molecular weights of these succinoglycans measured by light scattering are generally between 6.10⁶ and 10.10⁶, preferably between 6.5.10⁶ and 9.5.10⁶.

3. These succinoglycans also have very good rheological properties in solution in distilled water, especially at low concentrations.

Thus solutions at 0.1% by weight of a succinoglycan of this type in distilled water at 25 ° C have viscosities at 24 hours greater than 400 mPa.s and more particularly between 400 and 700 mPa.s; the viscosities being measured at a speed gradient of 1 s⁻¹ using a LOW SHEAR viscometer.

Similarly, 0.2% by weight aqueous solutions of one of these succinoglycans, at pH 1.7 and at 25 ° C., have a viscosity at 24 hours of between 1000 and 2500 mPa.s, more particularly between 1400 and 2000 mPa.s, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻¹.

Finally solutions of these same succinoglycans at 0.2% by weight in distilled water, subjected to a temperature of 80 ° C for 24 hours, generally have viscosities between 500 and 2500 mPa s and more particularly between 1000 and 2000 mPa s, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻¹.

The succinoglycans from the Agrobacterium tumefaciens I-736 strain can be obtained by a process which will be described in more detail below.

As mentioned above, these succinoglycans result from the fermentation by the aforementioned strain of a medium comprising at least one assimilable carbon source.

The medium is conventionally innoculated by the Agrobacterium tumefaciens I-736 strain.

When the volume of the fermentation medium is large, it can advantageously be inoculated by means of an innoculum medium, seeded with a liquid preculture medium; the latter being previously seeded itself by a pure culture of Agrobacterium tumefaciens I-736.

As an innoculum medium, any medium conventionally used for this purpose can be used, and advantageously a medium of a mineral nature. As preculture medium, mention may be made, for example, of YM bioth DIFCO Ref. 07101 and preferably a medium prepared from the following compounds: - Soy - peptones 5 g / l - Malt extract 3 g / l - Yeast extract 3 g / l - Glucose or sucrose 10 g / l

The natural pH of this medium from 7 to 7.2 and is not adjusted.

As organic source of carbon constituting the fermentation medium, there may be mentioned sugars such as glucose, sucrose, starch hydrolysates, and optionally lactose or native starch, as well as mixtures of these sugars. Glucose and sucrose are preferred sugars. The concentration of organic carbon source in the fermentation medium can be between 1 and 100 g / l and preferably between 15 and 60 g / l.

In addition to said assimilable carbon source, the fermentation medium can also contain at least one nitrogen source, preferably a source of organic nitrogen and optionally one or more mineral salts.

Mention may be made, as organic nitrogen source, of casein and caseinates, fish hydrolysates, wheat, corn or soy flour, yeast extracts (baker's yeast, brewer's yeast, lactic yeasts, etc.). .) Soluble dry distillers, potato proteins, corn steap liquor (CSL) and CSL solubles which are obtained by diluting the CSL, followed by elimination of solid particles by centrifugation, settling or decantation. CSL, and especially CSL solubles, have been found to be particularly advantageous in the context of the present invention.

The concentration of nitrogenous organic source in the fermentation medium can be between 3 and 80 g / l and preferably between 5 and 50 g / l.

Mention may be made, as mineral salts which may optionally be introduced into the fermentation medium, of the sulfates such as magnesium, manganese, zinc, iron sulfates, carbonates such as calcium carbonate, the salts soluble calcium, phosphates such as potassium, sodium phosphates.

The concentration of each of these mineral salts in the fermentation medium can vary between 0.01 and 5 g / l and preferably between 0.05 and 2 g / l.

The fermentation medium can also contain trace elements such as traces of cobalt and / or molybdenum salts, as well as vitamins and nucleotides.

Fermentation can be carried out at pressures between 1 and 4 bar at a temperature between 25 and 35 ° C, preferably between 28 and 32 ° C, under submerged aerobic conditions.

The pH of the fermentation medium can be between 5 and 9 and preferably between 6 and 8. The pH can be adjusted, as the case may be, with a base such as soda or potash or with an acid such as acid sulfuric, phosphoric acid, hydrochloric acid or nitric acid. The fermentation medium, placed for example in a fermentation tank or container, can advantageously be subjected to stirring.

This agitation can be exercised for example by means of a reciprocal shaker, a gyratory shaker, a stirring mobile or a bubble column. The fermentation time is usually more than 30 hours, but is generally between 40 and 90 hours.

Fermentation yields are generally greater than 40%, more particularly between 55-75% and very particularly between 60 and 75% by weight of succinoglycan produced relative to the carbon source used.

The succinoglycan can be separated from the fermentation medium.

To do this, the fermentation must containing the succinoglycan can advantageously be heated to temperatures between 80 and 120 ° C, for 10 to 60 minutes and preferably between 15 and 45 minutes.

The must subjected to the above heat treatment advantageously has a pH of between 6 and 8.

However, this pH can be adjusted if necessary, with a base or an acid as appropriate.

The latter can be chosen from the bases and the acids mentioned above used for adjusting the pH of the fermentation medium.

Recovery of the succinoglycan from the end of fermentation must can then be carried out by precipitation of said succinoglycan using an organic liquid miscible with water and in which the succinoglycan is insoluble or practically insoluble.

Mention may be made, as suitable organic liquids according to the present invention, of acetone, alcohols such as ethanol, propanol, isopropanol, butanol and tert-butanol.

Isopropanol is more particularly preferred in the context of the present invention.

The volume of organic liquid used is generally 2 to 3 times that of the volume of must to be treated.

The precipitation of succinoglycan by an organic liquid can also be carried out in the presence of salts such as sulfates, chlorides or phosphates of sodium, potassium, or calcium.

The succinoglycan once precipitated, can then be separated from the organic liquid by filtration, centrifugation or spinning.

The fibers obtained can be dehydrated, for example using acetone or an alcohol such as ethanol, propanol, isopropanol or tert-butanol.

The weight of alcohol required to perform this dehydration operation is generally 1 to 10 times that of the fibers to be treated.

The dehydrated fibers can undergo new centrifugation or spin filtration operations.

The fibers can then be dried, ground and sieved to obtain a powder.

In order to obtain an even purer powder, it is possible to treat either the fermentation must or an aqueous solution reconstituted from the powder obtained according to the process described above, by means of one or more enzymes.

As enzymes which may be suitable for this purpose, mention may be made of proteases, mutanases, lipoproteases, cellulases and chitinases.

Enzymatic purification can be combined or replaced by physical purification methods such as the various modes of filtration, of dialysis, or by the various techniques of chromatography.

Fermentation musts and reconstituted aqueous solutions of succinoglycan, whether or not subjected to a purification treatment, can be concentrated. Concentration can be advantageous in certain cases, in particular insofar as transport costs can be reduced. In addition, concentrated solutions can be implemented more quickly than powders. Concentration can be achieved by techniques such as evaporation, ultrafiltration, or by diafiltration.

The succinoglycans are used, in the context of the invention, in solid form in powder or in aqueous solution.

According to the invention, generally used from 0.001 to 2% by weight, preferably between 0.01 and 0.5% by weight of succinoglycan relative to the final suspension.

The suspensions of the invention comprising a succinoglycan of the type described above are particularly stable.

However, in order to reduce their viscosity and on a practical level to make them more manipulable and more pumpable, it is also possible to incorporate a dispersant therein.

According to a preferred embodiment of the invention, this dispersant is chosen from the group of siliconates and their derivatives.

Siliconates are well known products, they are salts of siliconic acid or its derivatives.

Mention may in particular be made of the products corresponding to formula (1):
R - Si (OM) _m (OH) _3-m (1)
and / or the condensation products thereof, formula in which R is a hydrocarbon residue generally of 1 to 18 carbon atoms, optionally substituted by a halogen atom, an amino group, ether, ester, epoxy, mercapto, cyano, (poly) glycol;
m is an integer or fractional number varying between 0.1 and 3;
M is an alkali metal or an ammonium or phosphonium group.

Preferably, R is a hydrocarbon residue of 1 to 10 carbon atoms and more particularly of 1 to 6 atoms.

More specifically, R can be an alkyl radical, for example methyl, ethyl, propyl, butyl, isobutyl; an alkenyl radical such as for example vinyl, an aryl radical, for example phenyl or naphthyl, an arylalkyl radical such as for example benzyl or phenylethyl, alkylaryl such as for example tolyl, xylyl, or an araryl radical such as biphenylyl.

For M, there may be mentioned more particularly sodium or potassium as well as the groups N + R′₄, P + R′₄ in which R ′ are identical or different and are hydrocarbon residues of 1 to 6 carbon atoms.

More particularly, alkaline siliconates are used. Alkaline earth siliconates can also be used.

Likewise, particular use is made of alkylsiliconates and in particular alkaline alkylsiliconates such as, for example, sodium or potassium methylsiliconates.

It is also possible to use the siliconates of formula 1 for which R is a vinyl or phenyl radical, and more particularly the alkali siliconates of this type.

It should be noted that alkali or alkaline earth siliconates are products, most of which are commercially available.

They can be prepared for example by hydrolysis of the corresponding silanes having 3 hydrolyzable groups such as halogen atoms, alkoxy radicals, followed by dissolution of the product obtained in a solution of a strong inorganic base in proportions such as there is at least one equivalent in base per atom of silicon (see for example US-A-2,441,422, US-A-2,441,423).

As an example of commercially available siliconates of this type, mention may in particular be made of RHODORSIL ^R SILICONATE 51T, sold by the Applicant, which is a potassium methylsiliconate.

As indicated above, the dispersant can also be chosen from siliconate derivatives.

By derivative products is meant here the condensation products of the products corresponding in particular to formula (1) described above, or those resulting from the at least partial polymerization into silicone compounds or polymers.

It is known, for example, that the alkali metal alkylsiliconates can be transformed into polyalkylsiloxanes, in particular by the action of carbon dioxide or other acidifying agent.

As a second type of dispersant suitable for the present invention, mention may also be made of silicone resins.

These silicone resins are well-known and commercially available branched organopolysiloxane polymers. They present, per molecule, at least two different motifs chosen among those of formula R₃SiO _0.5 (unit M), R₂SiO (unit D), RSiO _1.5 (unit T) and SiO₂ (unit Q).

The radicals R are identical or different and are chosen from linear or branched alkyl radicals, these radicals more particularly having from 1 to 6 carbon atoms included, vinyl, phenyl, trifluoro-3,3,3 propyl radicals.

More particularly, mention may be made, as alkyl radicals R, of methyl, ethyl, isopropyl, tert-butyl and n-hexyl radicals.

These resins are generally hydroxylated and in this case have a weight content of hydroxyl group of between 0.1 and 10%.

Examples of resins include MQ resins, MDQ resins, TD resins and MDT resins.

Resins having a molecular mass of less than 25,000 can be used more particularly.

As resin of this type, it is possible, for example, to use the products sold by the Applicant under the names RHODORSIL 865 A or 878 A.

It goes without saying that in the context of the present invention, it is possible to use in combination in the suspension two or more siliconates or derivatives or resins.

The siliconates are usually used in the form of aqueous solutions.

The amount of siliconate used depends on the specific surface of the zeolite. This amount is usually between 0.01 and 2%, more particularly between 0.05 and 0.3% by weight relative to the final suspension. This quantity is understood for a solution at 50% by weight in water of the siliconate or derivative.

The resins can be used in the solid state or in the form of aqueous emulsions or emulsion or solution in an organic solvent.

The amounts used are between 0.01 and 2% by weight of solid product, more particularly between 0.05 and 0.3 relative to the final suspension.

The use of siliconates or derivatives and resins as defined above has the effect of considerably lowering the viscosity of the zeolite suspensions. It also makes it possible to obtain stable suspensions with a higher dry extract, for example at least 55%.

However, without departing from the scope of the present invention, known dispersants can be used. Of course, here too, these dispersants can be used alone or in combination and even optionally in combination with the siliconates, their derivatives or the resins.

These dispersants can be chosen from the group comprising nonionic or anionic surfactants, macromolecular organic polymer compounds carrying carboxyl and / or hydroxyl groups, phosphates.

As nonionic surfactants, use may generally be made of compounds obtained by condensation of alkylene oxide with an organic compound which may be aliphatic or alkylaromatic.

Mention may in particular be made of polyoxyethylenated alkylphenols, polyoxyethylenated aliphatic alcohols, carboxylic amides, polyoxyethylenated and polyoxypropylene alcohols, in particular of the "PLURONICS" type.

Mention may also be made, by way of example, of ethoxylated tristirylphenol and ethoxylated nonylphenol.

Finally, mention may be made of surfactants of the sucroglyceride type.

As anionic surfactants, there are mentioned alkali metal soaps, alkali sulfonates, such as methylnaphthalene sulfonate, xylenesulfonate, beta-sulfoethyl esters of fatty acids, sulfates and sulfated products such as alkyl sulfates, fatty alcohols polyoxyethylenated and sulphated.

For macromolecular organic polymer compounds, the polymers of acrylic, hydroxyacrylic, maleic, itaconic acids, the copolymers of the acids mentioned above may be given together or with unsaturated compounds ethylenic such as ethylene, propylene, vinyl alcohol, vinyl acetate, methacrylic acid. We can refer in particular to the products given in FR-A-2 287 504.

Finally, as regards the phosphates, these can be chosen from the group of primary or secondary esters of orthophosphoric acid or one of its salts and mono or diesters of this acid or of its polyoxyethylenated salts. Mention may also be made of inorganic in particular alkaline phosphates such as pyrophosphate, tripolyphosphate, sodium hexametaphosphate.

Finally, it will be noted that it is possible to add a bactericidal agent to the suspensions of the invention.

The zeolite suspensions according to the invention are prepared in a simple manner by introducing the additives described above into the suspension and mixture. If necessary the pH of the zeolite suspension can be adjusted to the desired value in a known manner by the addition of any suitable neutralizing agent.

Suspensions comprising zeolites and stabilized by the systems which have just been described can be used in numerous applications.

They can be used in the form of suspensions based essentially on zeolites and the stabilizing additives mentioned above. In this case, they can enter into the preparation of detergent compositions. They can be used in any field other than detergency for which zeolites are used, for example in stationery.

The present invention also covers detergent compositions, in particular for liquid detergents, comprising, in addition to the suspensions based on zeolite and stabilizers of the invention, all the other additives known in detergency such as bleaching agents, foam control agents, anti-redeposition agents, perfumes, solvents, enzymes, optical agents.

Concrete examples will now be given.

EXAMPLES

Some definitions and details are given beforehand.

The dry extract of the suspension is given in percentage by weight of anhydrous zeolite determined by a measurement of loss on ignition at 850 ° C. for one hour.

The pH indicated is given for an aqueous dispersion containing 1% of dry zeolite and it is measured using a high alkalinity pH electrode.

The exchange capacity is given by the amount of calcium (expressed in mg of CaCO₃) exchanged with 1 g of anhydrous zeolite at 25 ° C. The measurement is carried out in the following manner: 0.4 g of zeolite (expressed as anhydrous) is introduced into a solution of 5.10⁻³ mole / l CaCl₂. The mixture is kept stirring for 15 minutes. After filtration, the excess calcium is dosed at pH 10 in return by EDTA in the presence of a colored indicator, black eriochrome T.

It will be noted that the system of the invention stabilizer-dispersant does not disturb this capacity.

As regards rheology, the RHEOMAT 30 equipped with the centered measurement system B is used as rheometer. The measurement consists in performing a cycle in speed gradient (ascent plus descent). The range of speed gradient explored is between 0.0215 and 157.9 s⁻¹, which corresponds to rotational speeds of the mobile from 0.0476 to 350 revolutions per minute. The viscosities reported in the examples correspond to measurements obtained during the descent in speed gradient.

The sedimentation is determined by introducing the zeolite suspension into graduated cylinders from 50 to 100 cc. The volumes of supernatant and decantate are measured every five days. The test pieces are left at room temperature (20 ° C) or placed in a thermostatically controlled enclosure.

The zeolite used is a 4A zeolite with an average diameter of primary particles of 3.5 μm.

Succinoglycan stabilizer

The succinoglycan used in the following examples can be prepared as follows:

A medium Agrobacterium tumefaciens I-736 is fermented containing a medium (in g / l): CSL (corn steap liquor) 11 K₂ HPO₄ 4 MgSO₄, 7H₂O 0.5 Sucrose 25 Drinking water qs 1 l

This medium is fermented by said strain at a temperature of 28 ° C., in a 20 liter BIOLAFFITE ^R tank containing a useful volume of 15 liters.

The medium is subjected to stirring at 400 revolutions / min obtained by means of RUSHTON ^R type mobiles.

The medium is aerated under an air flow of 825 l / h.

At the end of the fermentation, the recovery of the succinoglycan was carried out from 2 kg of must.

The must is heat treated at 90 ° C for 30 min.

To the must thus treated are added 2300 ml of isopropyl alcohol (IPA). The precipitation is carried out in the presence of 150 g of sodium sulfate.

The fibers from the precipitation are then dehydrated twice in the presence of 1200 ml of IPA.

The fibers are then wrung, shredded and dried in an oven at 85 ° C.

The collected dry matter is crushed and sieved.

A cream-colored product powder is then obtained.

EXAMPLE 1 TO 3

These examples show the stabilization of the zeolite suspensions by succinoglycan.

The suspension contains 45% by weight of zeolite.

The results are given in Table 1 below. Table 1 Example 1 2 3 comparative. Succinoglycan% by weight relative to the suspension 0.1 0.05 0 pH 11.48 11.48 11.52 Sedimentation supernatant% volume 20 ° C 50 ° C 20 ° C 20 ° C 50 ° C 5 days 0 2 <1 16 21 10 days <1 2 2.5 18 23 15 days 1 2 3 20 23 % Volume decantate 5 days 0 0 0 60 60 10 days 0 0 0 60 77 15 days 0 0 "1 80 77

EXAMPLES 4 TO 7

The results are given in Table 2 below.

With regard to RHODORSIL 51 T, the quantities indicated are in percentages by weight for a 50% aqueous solution of siliconate.

Resin A is a resin of the type described above for which R is a methyl radical. This resin is used here in the dry or solid state. It is marketed by the Applicant in the form of an emulsion under the reference RHODORSIL 865 A. Table 2 Example 4 5 6 7 comparison Suspension% anhydrous zeolite 48.8 49.9 49.2 49.7 Exchange capacity 291 297 274 323 Succinoglycan% by weight relative to the suspension 0.08 0.08 0.12 0 Dispersant% by weight relative to the suspension Rhodorsil Siliconate 51T 0.17 Rhodorsil Siliconate 51T 0.21 resin A 0.2 0 pH of the suspension 10.87 10.44 11.48 11.57 Rheology Viscosity (poises) at 4.74 s⁻¹ 11 15.4 14.4 59.2 at 32 s⁻¹ 6.3 6.6 6.6 Sedimentation Supernatant in% of volume 5 days 1 0 0 3.5 10 days 2 0.5 0 15 days 2 1 1 Decantate in% of volume 5 days 0 0 0 60 10 days <1 "1 0 15 days 1 1 "1

EXAMPLES 8 AND 9

Example 8 is a low quantity example of succinoglycan.

In Example 9, a resin "Resin B" is used which is a resin of the type described above in which R is methyl.

This resin is used here in the dry state. It is marketed by the Applicant in the form of an emulsion and under the reference RHODORSIL 878 A.

The results are given in Table 3 below.

EXAMPLES 10 TO 14

Example 10 describes the use as a dispersant of a nonionic surfactant of the sucroglyceride type sold by the Applicant under the name CELYNOL X8063.

Example 11 describes the use as a dispersant of a nonionic surfactant of the ethoxylated tristirylphenol type sold under the name SOPROPHOR S25, sold by the Applicant.

Example 12 relates to a dispersant of the anionic surfactant type which is a phosphated ethoxylated tristyrylphenol marketed under the name SOPROPHOR FL, marketed by the Applicants.

Examples 13 to 14 relate to acrylic polymers. Polymer 1 is an acrylic homopolymer with a mass of 2000. Polymer 2 is an acrylic-maleic copolymer with a mass of 70,000 and an acrylic / maleic ratio of 60/40.

The results are given in Table 4. Table 3 Example 8 9 Suspension% anhydrous zeolite 49.6 49.3 Exchange capacity 295 Succinoglycan in% by weight relative to the suspension 0.02 0.12 Dispersant% by weight relative to the suspension Siliconate 0.2 Resin B 0.2 pH of the suspension 10.67 11.49 Rheology Viscosity (poises) at 4.74s⁻¹ 13.3 14 at 32s⁻¹ 6.9 12.6 Sedimentation Supernatant in% of volume 5 days 1 5 10 days 5 15 days 2 5 Decantate in% of volume 5 days 2.5 0 10 days 0 15 days 0 Example 10 11 12 13 14 Suspension% anhydrous zeolite 49.3 49.3 49.3 49.3 49.3 Exchange capacity Succinoglycan in% by weight relative to the suspension 0.04 0.04 0.04 0.08 0.08 Dispersant% by weight relative to the suspension CELANOL 0.2 SOPROPHOR S25 0.2 SOPROPHOR FL 0.2 POLYMER 1 0.2 POLYMER 2 0.2 pH of the suspension 11.6 11.6 11.6 11.6 11.6 Sedimentation Supernatant in% of volume 5 days 0 0 0 0 0 10 days 15 days Decantate in% of volume 5 days 0 0 0 0 0 10 days 15 days

Claims (51)

1 - Aqueous suspension based on a zeolite, characterized in that it also comprises a succinoglycan. 2 - Suspension according to claim 1 characterized in that the zeolite represents from 40 to 51% of the weight of said suspension and the succinoglycan from 0.001 to 2% of the weight of said suspension. 3 - Suspension according to claim 2 characterized in that the succinoglycan represents from 0.01 to 0.5% of the weight of said suspension. 4 - Suspension according to any one of the preceding claims, characterized in that it comprises a succinoglycan obtained by fermentation of a medium comprising at least one carbon source assimilable by a strain of the Pseudomonas, Rhizobium meliloti, Rhizobium trifoli, Alcaligenes type faecalis, Agrobacterium radiobacter, Agrobacterium rhizogenes, Agrobacterium tumefaciens, one of their recombinants or one of their mutants. 5 - Suspension according to any one of the preceding claims, characterized in that it comprises a succinoglycan which after having passed the transition temperature has an intrinsic viscosity of at least 14000 ml / g, in particular at least 15000 ml / g. 6 - Suspension according to any one of the preceding claims, characterized in that it comprises a succinoglycan obtained by an Agrobacterium tumefaciens I-736 strain, one of its recombinants or one of its mutants. 7 - Suspension according to claim 6, characterized in that it comprises a succinoglycan which, after having passed the transition temperature, has an intrinsic viscosity of between 14000 ml / g and 25000 ml / g. 8 - Suspension according to claim 6 or 7, characterized in that it comprises a succinoglycan whose solutions at 0.1% by weight in distilled water at 25 ° C have viscosities at 24 hours greater than 350 mPa.s , and more particularly between 400 and 700 mPa.s, the viscosities being measured using a LOW SHEAR viscometer at a speed gradient of 1 s⁻¹. 9 - Suspension according to any one of claims 6 to 8, characterized in that it comprises a succinoglycan of which aqueous solutions at 0.2% by weight and whose pH is 1.7 and the temperature of 25 ° C , have a 24-hour viscosity between 1000 and 2500 mPa.s, and more particularly between 1400 and 2000 mPa.s, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻ ¹. 10 - Suspension according to any one of claims 6 to 9, characterized in that it comprises a succinoglycan of which 0.2% solutions in distilled water, subjected to a temperature of 80 ° C for 24 hours, have viscosities between 500 and 2500 mPa.s, and more particularly between 1000 and 2000 mPa.S, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻¹. 11 - Suspension according to any one of claims 6 to 10, characterized in that it comprises a succinoglycan which comprises units derived from glucose, galactose and pyruvic, succinic and acetic acids or salts of these acids in proportions molars, respectively from 5-8 / 1-2 / 0.5-2 / 0.5 - 2 / 0.05-2. 12 - Suspension according to claim 11, characterized in that it comprises a succinoglycan for which the abovementioned molar proportions are respectively from 6-7.5 / 1 - 1.5 / 0.5 - 1 / 0.5 - 1 / 0.05 - 0.2. 13 - Suspension according to claim 10, characterized in that it comprises a succinoglycan for which the abovementioned molar proportions are respectively 7/1 / 0.5 - 1 / 0.5 - 1 / 0.05 - 0.1. 14 - Suspension according to any one of claims 6 to 13, characterized in that it comprises a succinoglycan obtained by fermentation of a medium comprising as assimilable carbon source glucose, sucrose or a starch hydrolyzate. 15 - Suspension according to claim 14, characterized in that it comprises a succinoglycan obtained by fermentation of a medium further comprising a source of organic nitrogen. 16 - Suspension according to claim 15, characterized in that said organic nitrogen source is chosen from the group comprising casein and caseinates, wheat, corn or soy flour, yeast extracts, soluble dry distillers , potato protein, corn steap liquor and corn steap liquor solubles. 17 - Suspension according to any one of the preceding claims, characterized in that it further comprises a dispersant. 18 - Suspension according to claim 17, characterized in that it comprises as a dispersant a siliconate and / or a siliconate derivative. 19 - Suspension according to claim 18, characterized in that it comprises as dispersant a siliconate comprising as organic radical an alkyl, vinyl or phenyl group. 20 - Suspension according to claim 17 or 18, characterized in that it comprises an alkaline or alkaline earth siliconate. 21 - Suspension according to claim 17, characterized in that it comprises as a dispersant a silicone resin. 22 - Suspension according to claim 21, characterized in that the silicone resin has, per molecule, at least two different units chosen from those of formula: R₃SiO _0.5 , R₂SiO, RSiO _1.5 and SiO₂, the radicals R, identical or different, being chosen from vinyl, phenyl, trifluoro-3,3,3 propyl and linear or branched alkyl radicals. 23 - Suspension according to claim 22, characterized in that the silicone resin is hydroxylated and has a weight content of hydroxyl group of between 0.1 and 10%. 24 - Suspension according to claim 17, characterized in that it comprises a dispersant chosen from the group comprising nonionic or anionic surfactants, macromolecular organic polymer compounds, some comprising carboxyl and / or hydroxyl groups; phosphates. 25 - Suspension according to any one of the preceding claims, characterized in that it comprises a zeolite of type A, X or Y, in particular 4A or 13X. 26 - Process for the preparation of an aqueous suspension based on a zeolite characterized in that a succinoglycan is introduced into an aqueous suspension of zeolite and mixed. 27 - Process according to claim 26 characterized in that the zeolite and the succinoglycan are used in an amount such that the zeolite represents from 40 to 51% by weight of the fluid aqueous suspension and the succinoglycan from 0.001 to 2% by weight the fluid aqueous suspension. 28 - Process according to claim 26 or 27 characterized in that the succinoglycan is used in an amount such that the succinoglycan represents from 0.01 to 0.5% of the weight of the final suspension. 29 - Method according to any one of claims 26 to 28 characterized in that said succinoglycan is obtained by fermentation of a medium comprising at least one source of carbon assimilable by a strain of the type Pseudomonas, Rhizobium meliloti, Rhizobium trifoli, Alcaligenes faecalis , Agrobacterium radiobacter, Agrobacterium rhizogenes, Agrobacterium tumefaciens, one of their recombinants or one of their mutants. 30 - Method according to any one of claims 26 to 29 characterized in that said succinoglycan, after having passed the transition temperature, has an intrinsic viscosity of at least 14000 ml / g, in particular at least 15000 ml / g. 31 - Method according to any one of claims 26 to 30, characterized in that said succinoglycan is obtained by a strain Agrobacterium tumefaciens I-736, one of its recombinants or one of its mutants. 32 - Method according to claim 31, characterized in that said succinoglycan, after having passed the transition temperature, has an intrinsic viscosity between 14000 ml / g and 25000 ml / g. 33 - Method according to claim 31 or 32, characterized in that said succinoglycan is chosen from those whose solutions at 0.1% by weight in distilled water at 25 ° C have viscosities at 24 hours greater than 350 mPa. s, and more particularly between 400 and 700 mPa.s, the viscosities being measured using a LOW SHEAR viscometer at a speed gradient of 1 s⁻¹. 34 Method according to any one of claims 31 to 33, characterized in that said succinoglycan is chosen from those of which 0.2% by weight aqueous solutions, the pH of which is 1.7 and the temperature of 25 ° C, have a 24-hour viscosity between 1000 and 2500 mPa.s, and more particularly between 1400 and 2000 mPa.s, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻¹. 35 - Method according to any one of claims 31 to 34, characterized in that said succinoglycan is chosen from those of which solutions at 0.2% in distilled water, subjected to a temperature of 80 ° C for 24 hours, have viscosities between 500 and 2500 mPa.s, and more particularly between 1000 and 2000 mPa.s, the viscosities being measured using a LOW SHEAR viscometer, at a speed gradient of 1 s⁻¹. 36 - Process according to any one of claims 31 to 35, characterized in that said succinoglycan comprises units derived from glucose, galactose and pyruvic, succinic and acetic acids or salts of these acids in molar proportions, respectively of 5-8 / 1 - 2 / 0.5 - 2 / 0.5 - 2 / 0.05-2. 37 - Method according to claim 36, characterized in that the aforementioned molar proportions are respectively from 6-7.5 / 1 - 1.5 / 0.5 - 1 / 0.5 - 1 / 0.05 - 0.2 . 38 - Process according to claim 37, characterized in that the abovementioned molar proportions are respectively 7/1 / 0.5 1 / 0.5 - 1 / 0.05 - 0.1. 39 - Method according to any one of claims 31 to 38, characterized in that said succinoglycan is obtained by fermentation of a medium comprising as assimilable carbon source glucose, sucrose or a starch hydrolyzate. 40 - The method of claim 39, characterized in that said succinoglycan is obtained by fermentation of a medium further comprising a source of organic nitrogen. 41 - Method according to claim 40, characterized in that said organic nitrogen source is chosen from the group comprising casein and caseinates, wheat, corn or soy flour, yeast extracts, soluble dry distillers , potato protein, corn steap liquor and corn steap liquor solubles. 42 - Method according to one of claims 26 to 41, characterized in that one further introduces a dispersant. 43 - Process according to claim 42, characterized in that said dispersant is a siliconate and / or a siliconate derivative. 44 - Process according to claim 43, characterized in that said dispersant is a siliconate comprising as organic radical an alkyl, vinyl or phenyl group. 45 - Process according to claim 42 or 43, characterized in that said siliconate is an alkaline or alkaline earth siliconate. 46 - Process according to claim 42, characterized in that said dispersant is a silicone resin. 47 - Process according to claim 46, characterized in that the silicone resin has, per molecule, at least two different units chosen from those of formula: R₃SiO _0.5 , R₂SiO, RSiO _1.5 , and SiO₂, the radicals R, identical or different, being chosen from vinyl, phenyl, trifluoro-3,3,3 propyl and linear or branched alkyl radicals. 48 - Process according to claim 47, characterized in that the silicone resin is hydroxylated and has a weight content of hydroxyl group of between 0.1 and 10%. 49 - Process according to claim 42, characterized in that said dispersant is chosen from the group comprising non-surfactants ionic or anionic, macromolecular organic polymer compounds, some having carboxyl and / or hydroxyl groups; phosphates. 50 - Method according to any one of claims 26 to 49, characterized in that it comprises a zeolite of type A, X or Y, in particular 4A or 13X. 51 - Detergent composition, characterized in that it comprises a zeolite suspension according to any one of claims 1 to 25.