FR2804440A1 - LATEX FLUORINATED IN MINIDISPERSION IN WATER WITHOUT SURFACTANT OR ORGANIC SOLVENT - Google Patents

Abstract

The invention describes aqueous dispersions of fluorinated and / or hydrocarbon-based polymers stabilized by a macromolecular surfactant based on a hydrophilic polymer having a fluorinated block. The dispersions of the invention do not contain any micromolecular surfactant or organic solvent. The invention also describes the applications of such dispersions in the hydrophobic and oleophobic treatment of surfaces.

Description

LATEX FLUORES IN MINIDISPERSION IN WATER

  WITHOUT SURFACTANT OR ORGANIC SOLVENT.

  The invention relates to the field of aqueous dispersions of fluorinated and / or hydrocarbon polymers. It relates in particular to dispersions of fluorinated and / or hydrocarbon polymers stabilized by a macromolecular surfactant and containing neither organic solvent nor micromolecular surfactant. It also relates to the mode of synthesis of such dispersions as well as their uses in the hydrophobic and oleophobic treatment of

surfaces.

  Fluoropolymers are used in various industries, in particular for the hydrophobic and oleophobic treatment of different substrates such as textiles, leathers, papers. These fluoropolymers are generally prepared by polymerization in an organic solvent or according to the aqueous emulsion polymerization technique. For reasons of environmental constraints, they are generally prepared by polymerization in aqueous emulsion. The polymerization in water of fluorinated monomers and / or hydrocarbons poorly soluble in water generally requires large amounts of surfactants of different kinds to stabilize the fluorinated particles during the polymerization and also during storage. However, the presence of surfactants in coatings, in particular for the oleophobic and hydrophobic treatment of surfaces, can have drawbacks at the application level. It is therefore desirable to be able to produce coatings containing only

  high molecular weight molecules.

  Furthermore, the polymerization of fluorinated and / or hydrocarbon monomers very poorly soluble in water generally requires the use of a cosolvent which must be removed at the end of polymerization by distillation in order to have products.

  free of volatile organic compounds and without flash point.

  The remaining problem to be solved is the preparation of a dispersion of fluoropolymers containing neither organic solvent nor micromolecular surfactant. -2- Micromolecular and macromolecular surfactants such as linear polymers are commonly used in industry as stabilizers for the synthesis of polymers in emulsion, suspension or dispersion. The use of diblock or triblock copolymers has also developed in recent years as described in WO 9727222 and DE

19704714.

  On the other hand, the use of polymers with pendant chains for the stabilization and polymerization of oil-in-water emulsion is more recent. The known examples are limited to the case where the polymer is grafted with hydrocarbon chains and is used, for example, to stabilize emulsions of

  dodecane in water or polymerize styrene.

  According to the invention, the term “hydrocarbon compound” means any compound having a solubility parameter of less than 20 MPa. The Applicant has found that hydrophilic polymers having a fluorinated sequence can be used as a macromolecular surfactant in

  the preparation of aqueous dispersions of fluorinated and / or hydrocarbon polymers.

  Indeed, the Applicant has found that it is possible to stabilize a fine dispersion of fluorinated and / or hydrocarbon-based monomers with a hydrophilic polymer having a fluorinated block, to polymerize said monomers and to keep the dispersion thus obtained stable. This allows an aqueous dispersion of fluorinated and / or hydrocarbon polymers containing neither

  organic solvent and micromolecular surfactant.

  In fact, hydrophilic polymers carrying fluorinated chains tend to form aggregates in aqueous solution. The hydrophobic core of these aggregates constitutes a favorable environment for solubilizing fluorinated monomers. The subsequent introduction of an initiator into the reaction medium thus formed makes it possible to obtain latexes containing only polymers and therefore free of surfactant. This type of polymerization which is more akin to a polymerization in minidispersion than in conventional emulsion has the following advantages for fluorinated latexes -3 - reduce, even eliminate the phenomena of migration of surfactants in coatings and the harmful effects they can induce on its properties; -improve the stability of the latex both during polymerization and during storage by providing a steric protective effect, in the same way increasing its tolerance with respect to chemical agents (eg salts) and to shearing; favor the adsorption of the latex on the substrates which one wishes to treat in

  adapting the nature of the monomers constituting the hydrophilic polymer.

  o10 In addition, it is expected to obtain stable latexes at very low hydrophilic fluoropolymer concentrations because the critical aggregation concentration of such polymers is generally low. As a result, the polymer concentrations required will a priori be much lower than those currently

used with surfactants.

  Finally, the aggregates of hydrophilic fluoropolymers constituting a medium favorable to the solubilization of fluorinated monomers, it is hoped to reduce or even eliminate the use of cosolvents, resulting in a significant gain in production if the usual final distillation step is eliminated. solvent after polymerization

  and the direct production of products without volatile organic compound.

  One of the objects of the invention is an aqueous dispersion of fluorinated and / or hydrocarbon polymers containing: - from 5 to 50% by weight of at least one polymer (A) chosen from fluorinated and / or hydrocarbon polymers, and 1 at 15% by weight relative to the total weight of the polymers of

  minus one hydrophilic polymer (B) having a fluorinated block.

  Polymer B is the only surfactant in the dispersion.

  The dispersion of the invention also contains less than 1% by weight of

organic solvent.

  The polymer (A) according to the invention is synthesized from a) 0 to 100% by weight of one (or more) compounds (A1) having a polymerizable ethylene bond comprising a perfluoroalkyl group C2 to C20 -4 - b ) 0 to 100% by weight of an acrylic or methacrylic monomer (A2) with alkyl or alkoxyalkyl side chains of formula: R3- (R20) m (C (O) CH2) p-OOC-C (Rl) = CH2 ( 1) o R. represents a hydrogen atom or a methyl radical, R2 is an alkylene group of length C1 to C6, each R2 may be different from the other R3 is an alkyl group of length C1 to C24 or a cycloalkyl group of length C6 to C24, m is an integer between 0 and 10

and p is zero or one.

  c) 0 to 20% by weight of at least one polar monomer (A3) d) 0 to 30% by weight of one or more structural monomers (A4)

different from the previous ones.

  Examples of the structure of the monomers (A1) may be, without limitation, the following R 'I

(1) RFSO2-N - R "- OCOCR" '= CH2

R 'I

(2) RFR4SO2- N -R "- OCOCR" '= CH2

  (3) RF- (CH2) qOCOCR '= CH2 o RF represents a straight or branched perfluorinated chain, containing from 2 to 20 carbon atoms, preferably from 8 to 14 carbon atoms, R4 represents an alkyl radical comprising from 1 to 4 carbons, R 'is a hydrogen atom or an alkyl group containing from 1 to 10 carbon atoms, R "is an alkylene group containing from 1 to 10 carbon atoms, R"' is a hydrogen atom or a -5- methyl group, q is an integer between 1 and 11. Monomers of type (A1) whose structure is differentiated only by the length of the chain

  perfluorinated RF can be incorporated as a mixture in the copolymer.

  The preferred monomers (A1) of the invention are 2- (perfluorooctyl) ethyl acrylate or methacrylate and mixtures of 2- (perfluoroalkyl) ethyl acrylates or methacrylates comprising a perfluoroalkyl chain

in Csà C13.

  In the case of monomers of type (A2), R3 can be linear, connected

  or cyclical; R2 is a linear or branched chain and preferably is -

  C2H4-; preferably, m is 0 or 1 and p is zero. Representative monomers of formula (I) are, for example, butyl methacrylate, ethyl-2-hexyl methacrylate, stearyl acrylates and methacrylates

  and behenyl, acrylate and ethoxyethyl methacrylate.

  The preferred monomers (A2) of the invention are acrylate or

  stearyl methacrylate and behenyl acrylate.

  The polar monomers of type (A3) can be nonionic or ionic. As nonlimiting examples of nonionic monomers, mention may be made of: N-vinyl pyrrolidone-2 and its derivatives, acrylamide and methacrylamide and their derivatives, polyethylene glycol or ethylene glycol acrylates or methacrylates. As examples of ionic or ionizable monomers by variation of the pH, one can quote: Acrylic acid and methacrylic acid and their salts of alkali metals or of quaternary ammonium ions, sulfonated monomers like for example

  sodium vinyl sulfonate, sodium styrene sulfonate and 2- acid

  acrylamido-2-methyl-sulfonic, vinylpyridinium halides, acrylates and methacrylates of amino alcohols corresponding to the following formulas

HO-Y-NRsR6 or HO-Y-N + RsR6R7, A-

  In which the symbols Rs, R6, R7, identical or different, each represent an alkyl or hydroxyalkyl radical containing from 1 to 4 -6-carbons, Y represents an alkylene or hydroxyalkylene radical containing from 1 to 4

  carbons and A- is any monovalent anion.

  The monomers comprising reactive units capable of leading to chemical reactions between themselves or with other chemical groups present during the application (on the treated substrate for example) are also polar monomers included in the type monomers (A3). In particular, the monomers which can be commonly used comprise a hydroxyl group (N-methylolacrylamide or N-methylolmethacrylamide), or an epoxy group, or a tri or di alkoxysilane group, or an optionally blocked isocyanate group. Such monomers can be

used in combination.

  As monomers of type (A4), there may be mentioned, for example, vinyl or vinylidene halides such as: vinyl chloride, or vinylidene, vinyl fluoride or vinylidene, vinyl esters such as

  Vinyl acetate, vinyl propionate, trifluoro methacrylate 2,2,2-

  ethyl, isobornyl acrylate and methacrylate, acrylonitrile, styrene and its

  derivatives, butadiene, chloroprene, fluoroprene, isoprene and mixtures thereof.

  The hydrophilic fluoropolymer (B) used as sole surfactant consists of: (a) 0 to 80% by weight of at least one nonionic hydrophilic monomer (B1) (b) 1 to 75% of at least one monomer (B2 ) comprising a perfluoroalkyl radical, linear or branched, containing from 2 to 20 carbon atoms; and (c) 2 to 75% of one or more ionic hydrophilic monomer (s) or

ionizable (B3).

  (d) 0 to 30% by weight of one or more monomers of structure different from

previous (B4).

  It can be obtained by radical polymerization in a precipitating medium (as described in patent application No. 96 15097 of 09.12.96) or by other synthetic methods which are easier to carry out and less expensive than the polymerizations making it possible to obtain diblock or triblock copolymers

  (anionic polymerization, for example).

  -7- The monomers (B1), (B2) and (B 3) are described in patent No. 96 15097 incorporated by reference. The preferred monomer (B1) is acrylamide, the preferred monomers (B3) are acrylic acid, methacrylic acid, chloride

  of N- [2- (acryloyloxy) ethyl] -N, N, N-trimethylammonium and N- [2-

  (methacryloyloxy) ethyl] -N, N, N-trimethylammonium. The monomers of type (B4) have a different chemical structure from the monomers (B1) to (B3). In particular, the copolymer (B) can comprise a monomer with an alkyl side chain such as

  stearyl or palmitoyl methacrylate.

  Examples of hydrophilic fluoropolymers of type B are provided by the copolymers P1 and P2, obtained by reacting acrylamide, acrylic acid and a mixture of 2- (perfluoroalkyl) ethyl methacrylate in the following proportions: mole% introduced P P2 Acrylam ide 76 75.2 Acrylic acid 20 19.8 2 (Perfluoralkyl) ethyl methacrylate 3.4 4.9 Measured fluorine content 10.2 14 The copolymers Pl and P2 can for example be synthesized by a method of polymerization in a precipitating medium as described in the

  Patent application no 96 15097 dated 09.12.96).

  Another subject of the invention is a process for the preparation of aqueous dispersions of fluorinated and / or hydrocarbon polymers (A) such as those described above, consisting in - the dispersion in water of the mixture of monomers using 'an "efficient" disperser such as a high-pressure homogenizer, for example a valve homogenizer of the Manton Gaulin type, or an ultrasonic probe, and in the presence of a hydrophilic fluoropolymer

  (B) used as a macromolecular surfactant.

  - the polymerization of the mixture of monomers in the presence of an initiator at a temperature conventionally between 40 and c. The monomer mixture consists of: a) 0 to 100% by weight of one (or more) compounds (A1) having a polymerizable ethylene bond comprising a C2 to C20 perfluoroalkyl group b) 0 to 100% by weight of a acrylic or methacrylic monomer (A2) with alkyl or alkoxyalkyl side chains of formula: R3- (R20) m- (C (O) CH2) p-OOC-C (Rl) = CH2 (1) where Ri represents an atom of hydrogen or a methyl radical, R2 is an alkylene group of length C1 to C6, each R2 may be different from the other R3 is an alkyl group of length C1 to C24 or a cycloalkyl group, m is an integer between 0 and 10

and p is zero or one.

  c) 0 to 20% by weight of at least one polar monomer (A3) d) 0 to 30% by weight of one or more structural monomers (A4)

different from the previous ones.

  Examples of the structure of the monomers (A1I) can be, without limitation, the following: R 'I

(1) RFSO2 -N - R "- OCOCR" = C H 2

R '

(2) RFR4SO2 -N-R "- OCOCR" '= C H2

  (3) RF- (CH2) qOCOCR '"= CH2 99-o RF represents a straight or branched perfluorinated chain, containing from 2 to 20 carbon atoms, preferably from 8 to 14 carbon atoms, R4 represents an alkyl radical comprising from 1 to 4 carbons, R 'is a hydrogen atom or an alkyl group containing from 1 to 10 carbon atoms, R "is an alkyl group containing from 1 to 10 carbon atoms, R"' is an atom from hydrogen or a methyl group, q is an integer between 1 and 11 1. Monomers of type (A1) whose structure is differentiated only by the length of the chain

  perfluorinated RF can be incorporated as a mixture in the copolymer.

  The preferred monomers (A1) of the invention are acrylate or methacrylate

  2- (perfluorooctyl) ethyl and mixtures of 2- or acrylates or methacrylates

  (perfluoroalkyl) ethyl comprising a perfluoroalkyl chain from CQ to Cl3.

  In the case of monomers of type (A2), R3 can be linear, connected

  or cyclical; R2 is a linear or branched chain and preferably is -

  C2H4-; preferably, m is 0 or 1 and p is zero. Representative monomers of formula (I) are, for example, butyl methacrylate, ethyl-2-hexyl methacrylate, stearyl acrylates and methacrylates

  and behenyl, acrylate and ethoxyethyl methacrylate.

  The preferred monomers (A2) of the invention are acrylate or

  stearyl methacrylate and behenyl acrylate.

  The polar monomers of type (A3) can be nonionic or ionic.

  As nonlimiting examples of nonionic monomers, there may be mentioned: N-

  vinyl pyrrolidone-2 and its derivatives, acrylamide and methacrylamide and their

  derivatives, polyethylene glycol or ethylene glycol acrylates or methacrylates.

  As examples of ionic or ionizable monomers by variation of the pH, one can quote: Acrylic acid and methacrylic acid and their salts of alkali metals or of quaternary ammonium ions, sulfonated monomers like for example

  sodium vinyl sulfonate, sodium styrene sulfonate and 2- acid

  - 10- acrylamido-2-methyl-sulfonic, vinylpyridinium halides, acrylates and methacrylates of amino alcohols corresponding to the following formulas:

HO-Y-NRsR6 or HO-Y-N + RsR6R7, A-

  In which the symbols R5, R6, R7, identical or different, each represent an alkyl or hydroxyalkyl radical containing from 1 to 4 carbons, Y represents an alkylene or hydroxyalkylene radical containing from 1 to 4

  carbons and A- is any monovalent anion.

  The monomers comprising reactive units capable of leading to chemical reactions between themselves or with other chemical groups present during the application (on the treated substrate for example) are also polar monomers included in the type monomers (A3). In particular, the monomers which can be commonly used comprise a hydroxyl group (N-methylolacrylamide or N-methylolmethacrylamide), or an epoxy group, or a tri or di alkoxysilane group, or an optionally blocked isocyanate group. Such monomers can be

used in combination.

  As monomers of type (A4), there may be mentioned, for example, vinyl or vinylidene halides such as: vinyl chloride, or vinylidene, vinyl fluoride or vinylidene, vinyl esters such as

  Vinyl acetate, vinyl propionate, trifluoro methacrylate 2,2,2-

  ethyl, isobornyl acrylate and methacrylate, acrylonitrile, styrene and its

  derivatives, butadiene, chloroprene, fluoroprene, isoprene and mixtures thereof.

  The hydrophilic polymer B is that described above.

  By way of non-limiting example, an embodiment is described below.

of the process of the invention.

  The preparation of the aqueous dispersion is obtained by mixing the hydrophilic fluoropolymer, the monomers to be dispersed and water. The dispersion

  of the monomers is produced by supplying mechanical energy.

  To facilitate the dispersion, the procedure is carried out in 2 stages: a) in the first step, the hydrophilic fluoropolymer (B) used as stabilizer of the dispersion is dissolved in water at room temperature. Liquid monomers at temperature

- 11 -

  ambient can be poured as in the stirred aqueous phase. In the case of monomers crystallized at room temperature, the mixing is carried out at a temperature higher than the melting temperature of

  monomers and preferably less than 65 C.

  A pre-dispersion is prepared using a high shear agitator of the rotor-stator type (for example an Ultra Turax agitator) and leads to particles of size close to one micron which tend to sediment. b) The aim of the 2nd stage is to obtain smaller dispersed particles (= 100 nm) which will not sediment quickly. It consists in homogenizing the pre-dispersion using a high pressure homogenizer with Manton Gaulin valves. The dispersion thus obtained contains between 20 and 30% by weight of monomers between 1.5 to 2% of

  hydrophilic fluoropolymer (B) and the complement to 100% water.

  The polymerization of the monomers is carried out in batch, under nitrogen circulation. To initiate the polymerization reaction, it is possible to use catalysts or mixtures of catalysts capable of producing free radicals, such as peroxygen compounds, such as sodium, ammonium or potassium persulfate, alkaline perborates, hydrogen peroxide, hydrogen peroxide. sodium or barium, cumene hydroperoxide, butyl hydroperoxide, benzoyl peroxide, peracetic acid, amine oxides, ceric and ammonium nitrate, azo compounds such as azo 2, 2 'bis-isobutyronitrile, azo -2, 2 'bis (2,4-dimethyl-4, 4-methoxy valeronitrile), azo-4, 4' bis (4-cyano-pentanoic acid) or its alkaline salts, 2'-az dihydrochloride -isobutyramidine. The amounts to be used can vary between 0.01 and 5% relative to the weight of the monomers to be copolymerized, preferably from 0.1 to 1.5% /. The initiator used from

  preferentially is azo 2,2 'bis-isobutyronitrile.

  The copolymerization is generally carried out at a pH ranging from 2 to 9 and at a temperature between 40 o and 100 C, preferably between 50 o and 95 C. But it is possible to operate at higher or lower temperatures. For example, the use of redox catalysts, such as the persulfate-ferrous salt, sodium persulfate-hydroxy-methanesulfinate, hydrogen peroxide-bisulfite, hydrogen peroxide-butane-2,3-dione systems, may be useful for activating the reaction or lower the copolymerization temperature. The reaction can also be initiated under radiation, for example, with a mercury lamp

or sodium.

  The maximum conversion rate is usually reached in 30 minutes. The copolymers used according to the invention can be presented according to different types of structure. They can be homogeneous or have a segmented or heterogeneous shape. They can also consist of mixtures of homopolymers or fluorinated or non-fluorinated copolymers. The term copolymer used in the present invention encompasses all these structures, as well as all types of

  copolymers known to those skilled in the art.

  In order to adjust the molecular weight of the copolymers, it is possible to use

  chain transfer agents, such as alkyl mercaptans such as tertiary

  dodecyl-mercaptan, N-dodecyl-mercaptan, N-octyl-mercaptan,

  carbon tetrachloride, carbon tetrabromide, chloroform, triphenyl-

  methane. The quantities to be used can vary from 0.01% to 3% per

  relative to the weight of the monomers, and preferably between 0.05% and 0.5%.

  We preferentially use N-dodecylmercaptan.

  The dispersion and polymerization of fluorinated or / and hydrocarbon monomers are thus obtained without using a cosolvent, and without forming preflocs, unlike conventional methods of polymerization of this type of molecules. The usual final distillation step of the solvent is then avoided and

  directly obtains a product free of volatile organic compound (C.O.V.).

  The present invention also relates to the use of the dispersions of fluorinated and / or hydrocarbon polymers according to the invention for the hydrophobic and oleophobic treatment of a wide variety of supports, such as carpets, rugs, wall coverings, leathers, papers, materials for construction such as bricks, tiles, natural or reconstituted stones, ceramics, plasters, concretes, cements, mortars, wood, glass, metals and plastics. Mention may also be made of other very diverse supports such as, for example, woven or non-woven articles based on cellulose or regenerated cellulose, natural, artificial or synthetic fibers such as cotton, cellulose acetate, wool. , -13 silk, polyamide, polyester, polyolefin, polyurethane fibers or

polyacrylon itri le.

  The dispersions according to the invention can be applied, after dilution with water, using techniques known to those skilled in the art, for example, by coating with a doctor blade, a brush or a roller, impregnation, immersion, spraying, padding or coating. The amount of dispersion to be used varies within wide limits depending on the nature of the support and the fluorine content of the dispersion. Depending on their nature, the treated substrates can be dried at room temperature or at temperatures which can range from

up to 200 C.

  To obtain a particular effect or better fixation, it may be advantageous on certain supports to combine the dispersions according to the invention with certain additives such as fixing resins, catalysts, anti UV, fungicides,

  anti-static agents, anti-foaming agents etc ...

  For the treatment of leathers, the application of the diluted dispersions can be carried out according to different techniques, for example by spraying. You can also operate in full bath in a fuller or a sewing machine during the last stage of the wet process. The amount of fluorinated copolymer (A) applied is generally between 1 and 10 g of dry copolymer / m2. The leathers are preferably dried at room temperature or at a moderate temperature

up to around 100 C.

  Textile articles are, for example, commonly treated in padding baths containing a composition according to the invention diluted in water to a concentration of copolymer (A) conventionally between 4 and 20 g / l. The fabrics are then subjected to drying and optionally a heat treatment at a temperature of, for example, between 120 and 200 C. In order to give the textile substrates additional characteristics, various ingredients such as : catalysts capable of promoting the crosslinking of the copolymers with the substrate, thermally condensable products, reactive extenders comprising, for example, blocked isocyanate groups, water-repellent, flame-retardant, fungicides, antistatic, softeners, buffering agents, sequestering agents, bulking agents, bleaching agents optics, vinyl or acrylic latexes, polyalkylenes, polyglycols,

collar lodes.

  In the case of paper and cardboard, the compositions according to the invention can be applied either in the mass, ie added to the paper pulp, or superficially on the support already finished, using a press gluing machine, for example. To obtain the desired hydrophobicity and oleophobicity characteristics, the dispersions according to the invention are applied, diluted in water, to a concentration of copolymer conventionally of the order of 0.2 to 2% relative to the weight of fibers of cellulose. In the case of bulk application, a cationic polymer type retention agent (for example a polyamidoamine) can be added to the paper pulp before the addition of the fluorinated copolymer, so as to limit the loss of the fluorinated copolymer in white waters, when the sheet of paper is formed. A completely satisfactory retention of the fluorinated copolymer (of the order of 80% and more) is generally achieved for an amount of retention agent of between 0.1 and 2% relative to the weight of fibers. To obtain good fixation of the copolymers according to the invention on the papers and / or cartons to which they are applied and to additionally give a particular effect, it may also be advantageous to combine them with other adjuvants, polymers, thermally condensable products. and catalysts capable of promoting their crosslinking with the support. As such, there may be mentioned starches, polyvinyl alcohols, condensates and precondensates of urea formaldehyde or melamine formaldehyde, epoxy derivatives, polyamine-epichlorohydrin resins, glyoxal and its derivatives. The treated papers are dried under the conditions conventionally used in stationery, ie at a temperature of the order of 90 to 130 C. These fluorinated dispersions are applicable on paper according to different techniques (in size-press or in bulk) and confer excellent hydrophobic and oleophobic properties, in particular a spectacular resistance to original liquids

  aqueous, fatty substances and solvents of low surface tension.

  Such papers are used, for example, for the labeling of oil bottles or in the field of packaging of wet and / or fatty food products in markets as varied as the sector of - biscuit / pastry, fast food, the margarine and butter market, the meat and poultry market, the chocolate area,

  frozen products, the dry food market for dogs and cats (pet food).

  The hydrophobic and oleophobic performances of the substrates treated according to the invention are measured by means of oleophobia and hydrophobia tests.

conventional for those skilled in the art.

  The following examples illustrate the invention without limiting it.

Examples

Example 1

  a) preparation of the aqueous dispersion

  7 g of hydrophilic fluoropolymer P1 are dissolved in 238 g of water.

  The solution is brought to 40 C. 105 g of a mixture of 2- acrylates

  (perfluoroalkyl) ethyl CH2 = CH-COO-C2H4- (CF2) nCF3 with n between 5 and 13 (monomers of type A1) (0.185 mol) preheated to 40 C are poured into this

solution with mechanical stirring.

  The pre-dispersion is carried out using Ultra Turax for 3 minutes between 10 and 20,000 rpm depending on the foaming level. The system obtained is

opalescent and slightly fishy.

  This dispersion is then homogenized by making 10 passages with Manton Gaulin at a pressure of 1,000 bars. The final dispersion obtained is

  perfectly clear, no foaming is observed.

  a) polymerization of the fluorinated monomer dispersion In a 0.25 liter reactor, equipped with a thermometer, a reflux condenser, an anhydrous nitrogen supply, a dropping funnel, a mechanical stirrer, 221.5 g of the dispersion are introduced. Stirring is started, the reaction medium is brought to the temperature of 62 C, under nitrogen circulation. The reaction medium is maintained at this temperature under nitrogen for 30 minutes. A solution of 0.136 g (0.0008 mole) of azobis-isobutyronitrile in 2.67 ml of N-methyl pyrrolidone is then introduced into the reactor using the funnel, ie an initiator concentration of 0.68 % molar with respect to - 16 monomer, the initiation of the polymerization is practically carried out

the introduction of the initiator.

  A dry extract of 30.8% is obtained in the first 30 minutes of polymerization. b) characteristics of the dispersion The dispersion is stable stored at room temperature and at 60 ° C. for at least 2 months. The average particle size measured by diffusion of

  light is between 160 and 200 nm.

  Example 2: kinetics a) preparation of the aqueous dispersion

  7 g of the hydrophilic fluoropolymer P1 are dissolved in 238 g of water.

  g of 2- (perfluorooctyl) ethyl acrylate CH2 = CH-COO-C2H4- (CF2) 7-CF3 (monomer of type A1) (0.203 mol) are poured into the mechanically stirred aqueous phase. The dispersion is prepared as in Example 1 by carrying out 10 passages with Manton Gaulin at a pressure of 700 bars. The dispersion obtained is clear. b) polymerization of the fluorinated monomer dispersion In a 0.25 liter reactor, equipped with a thermometer, a reflux condenser, an anhydrous nitrogen supply, a dropping funnel, a mechanical stirrer, 223 g of the dispersion are introduced. Stirring is started, the reaction medium is brought to the temperature of 60 ° C., under nitrogen circulation and

  maintained at this temperature under nitrogen for 30 minutes.

  A solution of 0.138 g (0.0008 mole) of azobis isobutyronitrile in 2.68 g of N-methyl pyrrolidone is introduced into the reactor using the funnel, ie an initiator concentration of 0.63 mol% relative to the monomer. c) characterization of the dispersion During the polymerization, the dry extract (E.S.,% by weight) and the size of the particles formed are determined by light scattering (mean hydrodynamic diameter, nm). The values obtained before priming and over time after priming are indicated in the table below Time after E. S. Hydrodynamic priming diameter (% by weight) (min) (nm) o0

3.1 176

(before priming)

24.3 203

29.9 204

30.7 199

31.0 200

31.2 203

240 31.6 201

  A dry extract greater than 30% is obtained from the first 30 minutes after the introduction of the initiator, azobis isobutyronitrile. A dry extract of 31.6% is obtained at the end of polymerization. The average particle size is close to 200 nm throughout the polymerization, the polydispersity index being less than 0.15. The polymerization therefore takes place inside the particles.

  formed during the preparation of the dispersion.

  The final dispersion is stable stored at room temperature for at

  minus 4 months and at 60 C for at least 15 days.

Example 3

  a) preparation of the aqueous dispersion -18 -

  7 g of hydrophilic fluoropolymer P2 are dissolved in 238 g of water.

The solution is brought to 40 C.

  g of a mixture 50 / mol% of a mixture of 2- acrylates

  (perfluoroalkyl) ethyl CH2 = CH-COO-C2H4- (CF2), CF3 with n between 5 and 13 (type A1 monomers (0.116 mole) and stearyl methacrylate (type A2 monomer) (0.116 mole), preheated to 40 C, are poured into this solution under

mechanical agitation.

  The dispersion is prepared as in Example 1. The dispersion obtained

is white.

  b) polymerization of the dispersion of the monomer mixture 234.2 g of dispersion are introduced into a 0.25 liter reactor equipped as in Example 1. The reaction medium is brought to 60 ° C. with stirring and circulation of nitrogen and is kept there for 30 minutes. A reactor is introduced into the reactor.

  solution of 0.144 g (0.0009 mole) of azobis isobutyronitrile in 2.8 ml of N-

  methyl pyrrolidone, i.e. an initiator concentration of 0.39 mol% per

  compared to the monomers. A dry extract of 31.5% is obtained at the end of the test.

  c) characterization of the dispersion The dispersion is stable stored at room temperature for at least

  2 months. The average particle size is 164 nm.

  Examples 4: tests Oleophobia tests: The oleophobia is measured according to the test described in "AATCC Technical Manual", test method 118 (1992), which evaluates the non-wettability of the substrate by a series of oily liquids including surface tensions are becoming weaker. The rating of the treated substrate is defined as the maximum value of the test liquid which does not wet the support. The test liquids used in the evaluation are listed in the following table: -19- Rating Test liquids to measure Surface tension at oleophobia 25 C (mN / m) 1 N ujol 31.5 2 Nujol / n-hexadecane 29 , 6 (65/35 by volume) 3 nhexadecane 27.3 4 n-tetradecane 26.4 n-dodecane 24.7 6 n-decane 23.5 7 noctane 21.4 8 n-heptane 19.8 Hydrophobicity tests The hydrophobic effect is measured using test solutions numbered from 1 to 10 and constituted by water / isopropanol (IPA) mixtures in the following weight proportions: Test solution Isopropanol Water

1 90 10

2 80 20

3 70 30

4 60 40

50 50

6 40 60

7 30 70

8 20 80

9 10 90

0 100

  The test consists in depositing drops of these mixtures on the treated substrates, then observing the effect produced. The number corresponding to the solution which contains the highest percentage of isopropanol and which has not penetrated or wetted the substrate after 30 seconds of contact is noted, giving as a value. Application on leather: The dispersion synthesized in Example 3 is diluted at room temperature with distilled water to a concentration of 1% of active materials and the solution (S1) thus obtained is deposited on the surface of samples of leather on

- 20 -

  stain by cross spraying using a Volumair T21 sprayer. The

  average amount of solution (S1) deposited per unit area is 160 g / m2.

  The same latex is also diluted with 2% of active material to obtain the solution (S2) which is applied under identical conditions on the same support with a deposited quantity of 130 g / m2. After drying at room temperature for 18 hours and one hour in an oven at 80 ° C., the hydrophobic and oleophobic resistance of the treated leathers is evaluated, compared with that of untreated leathers. The results gathered in the

  following table demonstrate the effectiveness of dispersion 3 according to the invention.

  Test Test Quality of untreated hydrophobic oil repellency 0 0 Treated with (S1) 5 9 Treated with (S2) 6 10 The dispersion synthesized in Example 2 is diluted at room temperature with distilled water to a concentration of 1% of active ingredients and the solution (S3) thus obtained is deposited on the surface of leather samples on stain by cross-spraying using a Volumair T21 sprayer. During the first application test, the average amount of solution (S3) deposited by

surface unit is 131 g / m2.

  During a second test, the quantity deposited is 254 g / m2.

  After drying at room temperature for 18 hours and one hour in an oven at 80 ° C., the hydrophobic and oleophobic resistance of the treated leathers is evaluated, compared with that of untreated leathers. The results gathered in the

  following table demonstrate the effectiveness of dispersion 2 according to the invention.

  Test Test Quality of oleophobia hydrophobia leather Untreated 0 0 1st test 7 9 2nd test 8 10 -21 -

Claims (13)

CLAIMS:   1. Aqueous dispersion of fluorinated and / or hydrocarbon polymers containing: - from 5 to 50% by weight of at least one polymer (A) chosen from fluorinated and / or hydrocarbon polymers, and - from 1 to 15% by weight relative to the total weight of the polymers (A) of at least one hydrophilic polymer (B) having a fluorinated block, acting as the only surfactant,   the dispersion further containing less than 1% by weight of organic solvent.   2. Dispersion according to claim 1 characterized in that the polymer (A) is obtained by polymerization of a mixture of monomers containing: a) 0 to 100% by weight of one (or more) compounds (A1) having a polymerizable ethylene bond comprising a C2 to C20 perfluoroalkyl group, b) 0 to 100% by weight of an acrylic or methacrylic monomer (A2) with alkyl or alkoxyalkyl side chains of formula: R3- (R20) m (C (O) CH2) p-OOC-C (Rl) = CH2 (1) o R. represents a hydrogen atom or a methyl radical, R2 is an alkylene group of length C, at C6, each R2 may be different from the other R3 is an alkyl group of length C1 to C24 or a cycloalkyl group of length C6 to C24 m is an integer between 0 and 10 and p is zero or one, c) 0 to 20% by weight of at least one polar monomer (A3), d) 0 to 30% by weight of one or more monomers (A4) of structure different from the previous ones.   3. Dispersion according to claim 2 characterized in that the monomer A1 is chosen from the group containing the molecules corresponding to the following general formulas -22 - R 'I (1) RFSO2-N-- R "! - OCOCR" '= C H 2 R 'I   (2) RFR4SO2-N - R "! - OCOCR" '= C H 2   (3) RF- (CH2) qOCOCR "'= CH2 o RF represents a straight or branched linear perfluorinated chain, containing from 2 to 20 carbon atoms, preferably from 8 to 14 carbon atoms, R4 represents an alkyl radical containing from 1 to 4 carbons, R 'is a hydrogen atom or an alkyl group containing from 1 to 10 carbon atoms, R "is an alkylene group containing from 1 to 10 carbon atoms, R"' is a hydrogen atom or a methyl group, q is an integer included between 1 and 11.   4. Dispersion according to claim 3 characterized in that the monomer A1   preferred of the invention is chosen from 2- acrylate or methacrylate   (perfluorooctyl) ethyl and mixtures of 2- or 2- acrylates   (perfluoroalkyl) ethyl comprising a Cs to C13 perfluoroalkyl chain.   5. Dispersion according to one of the preceding claims, characterized in that the   monomer A2 is chosen from butyl methacrylate, ethyl-2-hexyl methacrylate, stearyl and behenyl acrylates and methacrylates,   ethoxyethyl acrylate and methacrylate.   -23 - 6. Dispersion according to claim 5 characterized in that the preferred monomer A2 is chosen from acrylate or stearyl methacrylate and acrylate of behenyl.   7. Dispersion according to any one of the preceding claims, characterized   in that the monomer A3 is chosen: - either from the group of nonionic monomers containing N-vinyl pyrrolidone-2 and its derivatives, acrylamide and methacrylamide and their derivatives, polyethylene glycol or ethylene glycol acrylates or methacrylates , - either in the group of ionic or ionizable monomers by variation of the pH, containing acrylic acid and methacrylic acid and their alkali metal salts or of quaternary ammonium ions, the sulfonated monomers such as for example vinyl sulfonate of   sodium, sodium styrene sulfonate and 2- acrylamido-2- acid   methyl sulfonic, vinylpyridinium halides, acrylates and methacrylates of amino alcohols corresponding to the following formulas: HO-Y-NRsR6 or HO-Y-N + RsR6R7, A-   In which the symbols Rs, R6, R7, identical or different, each represent an alkyl or hydroxyalkyl radical containing from 1 to 4 carbons, Y represents an alkylene or hydroxyalkylene radical containing from 1 to 4 carbons and A- is any monovalent anion. - either in the group containing the monomers comprising a   hydroxyl group (N-methylolacrylamide or N-   methylolmethacrylamide), or an epoxy group, or a tri or di alkoxysilane group, or an isocyanate group possibly blocked.   8. Dispersion according to any one of the preceding claims, characterized   in that the monomer A4 is chosen from vinyl halides or vinylidene halides such as: vinyl chloride, or vinylidene, vinyl fluoride or vinylidene, vinyl esters such as vinyl acetate, vinyl propionate vinyl, 2,2,2ethyl trifluoro methacrylate, isobornyl acrylate and methacrylate, acrylonitrile, styrene and its derivatives, butadiene, chloroprene, fluoroprene, isoprene and their mixtures.   9. Dispersion according to any one of the preceding claims, characterized   in that the hydrophilic fluoropolymer (B) used as sole surfactant consists of:   (e) 0 to 80% by weight of at least one non-hydrophilic monomer   ionic (B1) such as acrylamide, (f) 2 to 75% of at least one monomer (B2) comprising a perfluoroalkyl radical, linear or branched, containing from 2 to 20 carbon atoms; and (g) 1 to 75% of one or more ionic or ionizable hydrophilic monomer (s) (B3) chosen from acrylic acid, methacrylic acid,   N- [2- (acryloyloxy) ethyl] -N, N, N, trimethylammonium chloride and N-   [2- (methacryloyloxy) ethyl] -N, N, N-trimethylam monium.   (h) 0 to 30% by weight of one or more monomers of different structure precedents (B4).   10. Dispersion according to Claim 9, characterized in that the said polymer B preferably consists of: (e) 70 to 80% by weight of acrylamide, (f) 2 to 10% enpoidsdeB2,   (g) 10 to 30% by weight of acrylic acid or methacrylic acid.   11. Method for obtaining a dispersion according to any one of   previous claims consisting of   - dispersing the mixture of monomers in water using an "efficient" disperser such as a high pressure homogenizer, for example a valve homogenizer of the Manton Gaulin type, or a - 25 -   ultrasonic probe, and in the presence of a hydrophilic fluoropolymer (B) used as a macromolecular surfactant, - the polymerization of the mixture of monomers in the presence of an initiator or of a mixture of initiators at a temperature conventionally between 40 and 1 00 C, The mixture of monomers consisting of a) 0 to 100% by weight of one (or more) monomer (A1), b) 0 to 100% by weight of an acrylic or methacrylic monomer (A2), c) from 0 to 20% by weight of at least one polar monomer (A3), d) from 0 to 30% by weight of one or more monomers (A4) of structure different from the previous ones.   12. Use of the dispersion according to one of claims 1 to 10 in the   hydrophobic treatment of various supports, such as carpets, rugs, wall coverings, leathers, papers, building materials, woven or non-woven articles based on cellulose or regenerated cellulose and natural fibers or artificial.   13. Use of the dispersion according to one of claims 1 to 10 in the   oleophobic treatment of various supports, such as carpets, rugs, wall coverings, leathers, papers, building materials, woven or non-woven articles to   cellulose or regenerated cellulose base, and natural or artificial fibers.