MXPA96004037A - Aqueous polygonosiloxan emulsion for the removal of tex material - Google Patents

Abstract

The present invention relates to aqueous polyorganosiloxane emulsion suitable for the coating of textiles, comprising: a silicone phase, which is a precursor of an elastomer comprising at least one polydiorganosiloxane, optionally a crosslinking agent, optionally an inorganic filler, and a catalyst, and an aqueous solution of protective hydrocolloid, where the silicone phase does not contain any surfactant, and the emulsion is obtained by direct emulsification of the silicone phase and the hydrocolloid solution.

Description

L AQUEOUS POLYGONOSILOXAN EMULSION FOR TEXTILE MATERIAL COATING.

The present invention relates to an aqueous, polyorganosiloxane emulsion, mainly for the coating of substrates. of textile material or the like such as for example woven or non-woven supports, intended to produce a thin-film elastomer, as well as a corresponding coating process, and to the products coated in this way. In the numerous applications, it is sought to protect the textile material from heat, fire or other aggressions by means of a layer of silicone elastomer and / or to confer specific properties on certain applications. tions (dielectric properties for example). As applications, they can be applied mainly to inflatable bags used for the protection of the occupants of a vehicle, in English "air bag", braided glass (covered with glass fabric, thermal protection and dielectric for electrical cables), conveyor belts, fire-fighting or heat-insulating fabrics, compensators (flexible sealing sleeves for pipes), awnings, clothing ... Mainly with regard to inflatable bags of the "air bag" type, the essential properties sought are fire and temperature resistance, gas impermeability, stability to aging and good adhesion to the textile material, see in particular French patent FR-A-2 668 106. The coatings of silicone by coating the substrate, then hardening (crosslinking) the composition to form the elastomer. In certain applications, for reasons of economic competitiveness, it is sought to apply very thin layers of silicone, which becomes difficult with an elastomer 100% silicone; for example on a polyamide fabric 6. 6 of 235 or 470 dtex, the minimum amount that can be deposited by the classic techniques of scraper type 2 is of the order of 40 g / m or an average thickness of the order of 40 microns. To obtain lower quantities, it is necessary to resort to a silica elastomer put into operation in solvent phase, which is not very satisfactory from an industrial point of view, mainly due to problems related to the environment. It has also been proposed for textile applications, aqueous emulsions of non-crosslinking and uncharged silicone oils, which do not confer any thermal resistance. Recent developments of aqueous silicone emulsions with fillers also do not allow very low coating thicknesses to be obtained. Thus, European patent application EP-A-0 535 649 proposes a composition for the coating of inflatable bags "air bag", which comprises an organopolysiloxane (A) in emulsion in water, in the presence of an anionic emulsifier, an adhesion promoter (B), chosen from the reaction product between a silane with amino functional group or a hydrolyzate thereof, with an acid anhydride, a silane with an epoxide functional group or a hydrolyzate thereof and / or an organosilane having an isocyanate radical and a hydrolatable radical or a hydrolyzate thereof, a colloidal silica (C) and a catalyst (B). The objective of this composition is to allow coatings of thickness ranging from 40 to 100 μm. Approximately 100 coatings are mentioned. Similarly, the European patent application EP-A-0 552 983 describes a composition of the same type, obtained from an organopolysiloxane (A) having at least two alkenyl groups, an organohydrogen poly-siloxane (B) having at least three hydrogen atoms and a crosslinking (C), by emulsification in water in the presence of an emulsifier. A reinforcing filler such as a colloidal silica can be added. The objective is also to allow coatings of thickness from 40 to 100 μm. A coating of approximately 100 μm is mentioned. The object of the present invention is to provide a new composition and a new technique for obtaining coatings where the weight of the deposit is less than 40 g / m., that is to say with a thickness of less than about 40 μm, mainly of deposited weight 2 comprised between 5 and 40 g / m (between approximately 5 and 40 μm, of thickness), which are exploitable in the domain of the textile covering, in particular inflatable bags "air bag", glass braids, conveyor belts, fire-retardant fabrics or thermal insulators, compensators, awnings, clothing, etc. Another object of the invention is that it can be applied to elastomeric compositions of silicones in general, in particular those which are cold-curing or optionally at a higher temperature, which are single-component or multi-component, or even polyaddition or polycondensation. Another object of the invention is to propose compositions and techniques which are easy and inexpensive to implement, and which also allow, in the case of a thinner coating than the ordinary, a material gain not negligible. Another object of the invention is therefore to allow reducing the amount of silicone material for a given application, without prejudice to the characteristics of the final product. The subject of the present invention is therefore an aqueous polyorganosiloxane emulsion, mainly for the coating of textile or analogue material, in particular fabrics of the type described above, comprising an organopolysiloxane formula, elastomer precursor, comprising a polydiorganosiloxane, preferably a filler. mineral, a catalyst and even a crosslinker, but devoid of surfactant, characterized in that the organopolysiloxane formula is an emulsion in an aqueous solution of protective hydrocolloid, and because this emulsion is obtained by direct emulsification of the complete organopolysiloxane formula in the Aqueous solution of protective hydrocolloid. By "protective hydrocolloid" is meant a polymer that has both hydrophilic groups and groups compatible with the silicone phase. The protective hydrocolloid is preferably a polyvinyl alcohol (APV) or a mixture of APV and, preferably APV in aqueous solution at a dynamic viscosity type rj comprised between 5 and 40 mPa.s, preferably between 10 and 30 mPa.s, and an ester index greater than or equal to 80, preferably to 100, and principally comprised between 120 and 200.

Polyvinyl alcohols (APV) are compounds obtained indirectly from their esters, by hydrolysis in aqueous medium or by alcoholysis in anhydrous medium. In practice, the materials used as raw material are commonly polyvinyl acetates. In general, the lysis of the esters that leads to VCT is not complete. Acyl radicals remain in the molecule where the proportion influences the properties of the APV, mainly on its solubility. One mode of definition of the APV lies therefore in the indication of the ester index (I.E) which is inversely proportional to the rate of hydrolysis. The measurement of the IE is carried out in a manner known per se, by neutralization of the eventual acidity of the polyvinyl alcohol, saponification of the acyl groups and titration of the excess of alkalinity. The polyvinyl alcohols according to the invention are also characterized by their degree of condensation, which can be evaluated by determining the dynamic viscocity of a standard solution (designated by n .. in the present description), inferring that this variable is both higher when the degree of condensation is higher. The viscocity n. corresponds to the dynamic viscocity coefficient of an aqueous solution of APV at 4% by weight, measured at a temperature of 20 ± 5 ° C with the help of an Ostwald viscometer. As another protective hydrocolloid, mention may also be made of water-dispersible sulphonated polyesters, in particular of the sulfonated polyethylene terephthalate type. Water-dispersible sulfonated polyesters are known and commercially available products. These can be prepared by co-condensing an organic diacid (such as a saturated or unsaturated aliphatic diacid, an aromatic diacid, a diacid having several aromatic nuclei, an aryl-aliphatic diacid), one of the diesters or its anhydride and a sulfonated organic diacid, or one of its diesters with a diol, in the presence of a usual polyesterification catalyst such as tetraisopropyl orthotitanate. As starting monomers commonly used for the preparation of the sulfonated, water-dispersible polyesters, the following may be mentioned: organic diacids: saturated or unsaturated aliphatic diacids, aromatic diacids, such as succinic, adipic, suberic, sebacic acids , the maleic, fumaric, itaconic, orthophthalic, isophthalic, terephthalic acids, the anhydrides of these acids and their diesters, such as the methylene, tylic, propyl, butyl diesters. Preferred compounds are adipic acid, orthophthalic, isophthalic, terephthalic acids; - sulfonated organic diacids: sulfonated sodium diacids or their diesters such as dialkyl isophthalates and dialkylsulfosuccinates such as sodium 5-dimethylisophthalate sulphonate or sodium dimethyl sulfosuccinate; diols: aliphatic glycols such as ethylene glycol, diethylene glycol, dipropylene glycol and higher homologs, 1-butane-4-diol-1,6-hexanediol, neopentyl glycol and cyclic glycols such as cyclohexanediol, and dicyclohexanediolpropane. The diols chosen are preferably ethylene glycol and diethylene glycol. The preferred water-dispersible sulfonated polyesters are those having a number average molecular mass of between 10,000 and 35,000, an acid number of less than 5 mg of KOH / g, a proportion of sulfur comprised between 0.8 and 2% by weight. weight, preferably between 1.2 and 1.8%. As polyesters of this type, the products marketed by Rhone Poulenc under the trademark GER0L PS20 can be used mainly. Preferably, a ratio of 1 silicone phase / hydrocolloid phase is chosen in order to have a ratio of dry extract comprised between 10 and 60, preferably between 40 and 60. The aqueous solution of protective hydrocolloid 5 may also comprise at least one surfactant which can be anionic, cationic or non-ionic, in particular a polyethoxylated fatty alcohol. It is understood that in the case of the use of a polyester, the person skilled in the art will exclude cationic surfactants. Preferably, the surfactants will be non-ionic. The proportion of surfactant / hydrocolloid is mainly comprised between 0 and 10%. The role of the surfactant will be mainly to refine the granule size of the emulsion and eventually to improve its stability. The invention makes it possible to prepare an aqueous emulsion in the presence or in the absence of a mineral charge, and very advantageously in the absence of the surfactant, which makes it possible to obtain a preparation capable of being or applied in very thin layer, mainly of thickness less than 40 μm, for example between 5 and 40 μm, in order to secure the elastomer formed with good properties, compatible mainly with the aforementioned uses. The macromolecule (hydrocolloid) 5 also has the advantage of increasing the fixation of the elastomer on the tissue, in the manner of a glue or glue, and of conferring a waterproofing power to the gas, supplementary, particularly interesting in the applications of air bags . The formula of the polyorganosiloxanes according to the invention comprises the polyorganosiloxane (s) which will generate the elastomer. It is preferably a formula that is hardenable at room temperature (23 ° C) and then the withdrawal can be accelerated by a higher temperature. Preference is given to cold-vulcanizable, polyaddition or polycondensation elastomers. Hot vulcanizable elastomers also fall within the scope of the present invention. As said, the silicone elastomers can be prepared from a two-component precursor system, formed of two distinct parts intended to be mixed. Once in the presence, reactive two-part compounds can react and crosslinking ensues. For such systems, the emulsion according to the present invention comes from the meeting of two different emulsions, each prepared by the step of direct emulsification of the corresponding formula part. The present invention also has as its object a device comprising the two emulsions corresponding each to a part of the polyorganosiloxane formula, these two emulsions being prepared by direct emulsification of the formula part in its aqueous emulsion part of the formula. protective hydrocolloid However, the compositions of a single component also fall within the scope of the invention, and especially the polyaddition or polycondensation compositions designed not to crosslink except under the effect of an external action such as that known per se. For example, these single component compositions may comprise a classical crosslinking inhibitor or encapsulated catalysts in a manner known per se. Thus, in all cases where it is possible to collect all the components within a single formula, a single emulsion will be used. The curable organopolysiloxane compositions, usable in the context of the process according to the present invention, comprise a main constituent preferably composed of one or more polydiorganosiloxanes, preferably polydimethylsiloxane (PDMS), a suitable catalyst, at least one filler, a crosslinker according to the case and possibly an adhesion promoter. The organopolysiloxanes, main constituents of the compositions according to the invention, can be linear, branched or crosslinked, and possess hydrocarbon radicals and / or reactive groups such as, for example, hydroxyl groups, hydrolyzable groups, alkenyl groups, hydrogen atoms, etc. It should be noted that the organopolysiloxane compositions are widely described in the literature and principally in the work of alte NOLL: "Chemistry and Technology of Silicones", Academic Press, 1968, 2nd Edition, pages 386 to 409. More precisely, the organopolysiloxanes, main constituents of the compositions according to the invention, are composed of siloxyl portions of the general formula: RnSiO4.-n (II) 0 and / or of the siloxyl portions of the formula ZxRySiO4, -? - and (III) In the formulas, the various symbols have the following meaning: the symbols R, identical or different, each represent a group of hydrocarbon nature not hydrolysable, this radical can be: * an alkyl radical, halogenoalkyl having 1 to 5 carbon atoms, and having 1 to 6 chlorine and / or fluorine atoms, * the cycloalkyl and halogenocycloalkyl radicals having from 3 to 8 carbon atoms and containing from 1 to 4 chlorine atoms and / or of fluorine, * the aryl, alkylaryl and halogenaryl radicals having 6 to 8 carbon atoms, and containing 1 to 4 fluorine atoms, * the cyanoalkyl radicals having 3 to 4 carbon atoms; - the Z symbols, identical or different, each represent a hydrogen atom, an alkenyl group, a hydroxyl group, a hydrolysable atom, or a hydrolysable group; - n = an integer equal to 0, 1, 2 or 3; - x = an integer equal to 0, 1, 2 or 3; - y = an integer equal to 0, 1 or 2; - the sum of x + y is between 1 and 3. Illustratively, organic radicals R, directly linked to the silicon atoms: methyl groups; ethyl; propyl; isopropyl; butyl; isobutyl; n-pentyl; t-butyl; chloromethyl; dichloromethyl; alpha-chloroethyl, alpha.beta-dichloroethyl; flouromethyl; difluoromethyl; alpha.beta-difluoroethyl; 3, 3, 3-trifluoropropyl; trifluorocyc-clopropyl; 4, 4, 4-trifluorobutyl; 3, 3, 4, 4, 5, 5-hexafluoropentyl; beta-cyanoethyl; gamma-cyanopropyl; phenyl; p-chlorophenyl; m-chlorophenyl; 3, 5-dichlorophenyl; trichlorophenyl; tetrachlorophenyl; o-, p-, or m-tolyl; alpha, alpha, alpha-trifluorotolyl; xylyls such as 2,3-dimethylphenyl, 3,4-dimethylphenyl. Preferably, the organic radicals R linked to the silicon atoms are the methyl radicals, phenyl, these radicals possibly being halogenated or even the cyanoalkyl radicals. The symbols Z can be hydrogen atoms, hydrolysable atoms such as halogen atoms, in particular chlorine atoms, vinyl groups, hydroxyl groups or hydrolyzable groups such as: amino, amido, aminoxy, oxime, alkoxy, alkenyloxy, acyloxy, etc . The nature of the organopolysiloxane and the proportions between the siloxyl (II) and (III) portions and the distribution of these, is like that chosen according to the crosslinking treatment that will be carried out on the curable (or vulcanizable) composition with a view to its transformation into elastomer. It is possible to use a wide variety of one-component or two-component compositions, which are crosslinked by the polyaddition or polycondensation reactions in the presence of a metal catalyst, and optionally a crosslinker and / or an amine. The two-component or single-component organopolysiloxane compositions crosslinking at room temperature or with heat by polyaddition reactions, essentially by reaction of the hydrogenosilyl groups on the alkenyl-silyl groups, in the presence of a metal catalyst in general, preferably of platinum, are described for example in the North American patents Nos. 3 220 972, 3 284 406, 3 336 366, 3 697 473, and 4 340 709. The organopoly siloxanes which enter into these compositions are generally made up of pairs based on a part of at least one linear, branched or cross-linked polysiloxane, constituted of the portions (III) in which the residue Z represents an alkenyl group and where x is at least equal to 1, optionally associated with the portions (II) , and on the other hand of at least one linear, branched or crosslinked hydrogeny-polysiloxane, constituted of the portions (III) in which the residue Z represents in such case u n hydrogen atom, and where x is at least equal to 1, possibly associated with the portions (II). Concerning the unsaturated polysiloxane constituent in portions (III), it can be an oil of dynamic viscosity at 25 ° C, between 200 and 500,000 mPa. s. If necessary, a mixture based on the aforementioned oil can be used in the manner of this constituent, with an unsaturated gum with a viscosity of more than 500,000, and can even reach up to 10 raPa.s. Two-component or single-component organopolysiloxane compositions which crosslink at room temperature by the poly condensation reactions under the action of moisture, in the presence of a metal catalyst, for example a tin compound, are described by example for the one-component compositions in US Pat. Nos. 3 065 194, 3 542 901, 3 779 986, 4 417 042, and in French patent FR-A-2 638 752, and for compositions of two components in US Pat. Nos. 3,678,002, 3,888,815, 3,933,729 and 4,064,096. The organopolysiloxanes which enter these compositions are in general linear, branched or crosslinked polysiloxanes constituted of the portions (III) in the wherein the residue Z is a hydroxyl group or an atom or a hydrolyzable group, and where x is at least equal to 1, with the possibility of being able to have at least one residue Z that is equal to a hydroxyl group or an atom, or a gru hydrolysable product, the portions (III) being optionally associated with the portions (II). As regards the unsaturated polysiloxane constituent in portions (III), it can be an oil of dynamic viscosity at 25 ° C, between 200 and 500,000 mPa.s. Similar compositions may further contain a crosslinking agent which is primarily a silane having at least three hydrolyzable groups such as, for example, a silicate, an alkyl trialkoxysilane or an amino-alkyltrialkoxysilane. more preferably, the polycondensation compositions further possess at least one silicone resin. These silicone resins are branched organopolysiloxane polymers, well known and commercially available. These present per molecule, at least two different portions chosen from those of the formula R "SÍ0Q 5 (portions M), R2Si0 (portions D), RSi01 5 (portions T) and Si02 (portions Q).

The radicals R are identical or different and are selected from linear or branched alkyl radicals, vinyl, phenyl, 3, 3, 3-trifluoropropyl radicals. Preferably the alkyl radicals have from 1 to 6 carbon atoms inclusive. More particularly, alkyl radicals R, methyl, ethyl, isopropyl, tertbutyl and n-hexyl radicals may be mentioned. These resins are preferably hydroxylated and in this case have a weight ratio of hydroxyl groups comprised between 5 and 500 meq / lOOg. Examples of resins are MDQ resins, TD resins and MDT resins. Likewise, the polyadi-tion compositions may also possess resins of the above-mentioned, non-hydroxylated type, in which a part of the R radicals are vinyl residues (weight ratio in Vi mainly comprised between 10 and 40 meqVi / lOOg) . These vinyl functions are carried by the portions M, D or T. As an example we can mention the vinyl MDQ resins. The mineral charges are preferably chosen between the combustion silicas and the precipitated silicas. These have a specific surface, measured 2 according to the BET methods, of at least 50 m / g, mainly between 50 and 400 m / g, 2 preferably higher than 70 m / g, a mean dimension of lower primary particles at 0.1 micrometer (μm) and an apparent density of 200 g / liter. These silicas can be incorporated as such, then they can be eventually treated by one or more organosilicon compounds usually used for this use. These silicas can also be incorporated after treatment with an organosilicon compound. These compounds include methylpolysiloxanes such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, methylpolysilane-zanos such as hexamethyldisilazane. hexamethylcyclo-trisilazane »chlorosilanes such as dimethyl dichlorosilane, trimethylchlorosilane, methyl vinyl dichlorosilane, dimethylvinylc lorosilanes, alkoxysilanes such as dimethyldimethoxysilane, dimethyl vinyl ethoxy silane, trimethylmethoxysilane etc. After this treatment, the silicas can increase their initial weights up to a proportion of 20%. They can also be used in addition to the charges of silicon, other mineral charges such as crushed quartz, calcined clays and earths of diatoms. With regard to non-siliceous mineral materials, these can intervene as semi-reinforcing mineral fillers, fillers or for specific properties. Examples of these non-siliceous fillers, usable alone or as a mixture, are carbon black, titanium dioxide, aluminum oxide, hydrated alumina, expanded vermiculite, unexpanded vermiculite, calcium carbonate, zinc oxide, mica, talc, oxide of iron, barium sulfate and slaked lime. These fillers have a granule size in general between 0. 01 and 300 μm and a BET specific surface area below 100 m / g. It is generally possible to use 0.5 to 50% by weight, preferably 10 to 25% by weight, based on the weight of the silicone phase of the formula. Preferably, the organopolysiloxane formula further comprises one or more adhesion promoters. These may be classically used promoters. However, in the case of the polyaddition formulas, the adhesion promoters are mainly chosen from the group consisting of: the alkoxylated organosilanes containing, per molecule, at least one alkenyl group having from 2 to 6 carbon atoms, the compounds organosilicon compounds comprising at least one epoxy radical, and - the metal chelates M and / or the metal alkoxides of the general formula: M (OJ), with n - at the valence of M and J = linear or branched alkyl of 1 to 8 carbon atoms, M being selected from the group consisting of: Ti, Zr, Ge, Li, Fe, Al, Mg. It can be mainly an adhesion promoter mixture comprising at least one compound selected from the three groups defined above. According to a preferred embodiment of the invention, the alkoxylated organosilane is more particularly selected from the products of the following general formula: wherein: 1 2 3 - R, R, R are hydrogenated or identical hydrocarbon radicals or different and preferably represent hydrogen, a linear or branched alkyl of 1 to 4 carbon atoms, or a phenyl optionally substituted by at least an alkyl of 1 to 3 carbon atoms. - A is a linear or branched alkylene of 1 to 4 carbon atoms, - G is a valence bond or oxygen, - R 4 and R 5 are identical or different radicals and represent an alkyl of 1 to 4 carbon atoms, linear or branched, - x '- 0 or 1, - x = 0 to 3, preferably 0 or 1 and more preferably even 0. Without this being limiting, vinyltrimethoxysilane can be considered to be a particularly appropriate compound (IV). In the case of the organosilicon compound, it is provided according to the invention to choose it preferably from: - either among the products that meet the following general formula: *? in which a. R is a linear or branched alkyl radical of 1 to 4 carbon atoms, b. R is a linear or branched alkyl radical, c. and is equal to 0, 1, 2 or 3, preferably 0 or more preferably equal to 0, with 0 E and D being identical or different radicals are chosen from alkyl groups of 1 to 4 carbon atoms, linear or branched, z is equal to 0 or 1, ° R,. R, R being identical or different radicals, represent hydrogen or a linear or branched alkyl group of 1 to 4 carbon atoms, with hydrogen being more particularly preferred, and R and R or R may alternatively constitute together with the two carbon atoms carrying of the epoxy, a cycloalkyl having from 5 to 7 members, or else from the products constituted by the polyorganosiloxanes with epoxy functional groups, which possess at least a portion of the formula: XPGqSiO4.-, (p + .q) VI in which: X is the radical as defined above for formula V, G is a monovalent hydrocarbon group, free of unfavorable action on the activity of the catalyst and is preferably chosen from alkyl groups having from 1 to 8 carbon atoms inclusive, optionally substituted by at least one halogen atom, advantageously between the methyl, ethyl, propyl and 3, 3, 3-trifluoropropyl groups, as well as between the aryl groups and, advantageously, between the xylyl radicals, tolyl and phenyl,. p = 1 or 2,. q = 0, 1 or 2. p + q = 1, 2 6 3 optionally at least a part of other portions of these polyorganosiloxanes are the portions of average formula: GrSiO4.-r VII wherein G has the same meaning as the above-mentioned, and r has a value between 0 and 3, for example between 1 and 3. The organosilicon compounds are thus preferably epoxyalkoxysilicic and more preferably even the epoxyalkoxymonosilanes. By way of example of such compounds, there may be mentioned: 3-glycidoxypropyltrimethoxysilane (GLYMO) or 3,4-epoxycyclohexylethyltrimethoxysilane. As regards the last group, the preferred products are those in which the metal M is chosen from the following list: Ti, Zr, Ge, Li, Mn. It should be emphasized that titanium is more particularly preferred. It can be associated, for example, with an alkyl radical of butyl type. As regards the polycondensation compositions, the compounds belonging to the family of the aminated silanes, such as the aminoorganosilanes, aminoorganopolysiloxanes and guanidino-organosilanes which they possess per molecule at the same time, will advantageously be used as adhesion promoters: ) at least one organic group of 3 to 15 carbon atoms linked by a SiC bond to the silicon atom, and substituted by at least one amino radical or a guanidino radical, and (ii) at least one alkoxy radical of 1 to 6 atoms of carbon or an alkoxyalkylene-oxy radical of 3 to 6 carbon atoms. Mention may be made in particular of the silanes of formula ..

H2N (CH2) 3Si (OCH3) 3 H2N (CH2) 3Si (0C2H5) 3 H2N (CH2) 2NH (CH2) 3Si (OCH3) 3 It may also be epoxidized silanes (organosilicon compounds having at least one epoxy radical) such as described above for the polyaddition compositions. For more details on the synthesis of the organosiloxanes (a ') and on their use to prepare the organopolysiloxane compositions, mo > -non-components, which crosslink at room temperature by means of the polycondensation reactions under the action of humidity, can be mentioned very particularly in the French patent FR-A-2 638 752, where the content is incorporated herein by reference. The preferred formulas for polyaddition are in a general way an association. from 0 to 80% of a colloidal silica dispersion in a divinilated silicone oil. The silica is a reinforcing filler, with a specific surface 2 comprised between 50 and 400 m / g; This is between 10 and 60% in the dispersion. . from 10 to 90% of a omega-di-nylated alpha oil where the proportion of the vinyl groups is between 2 and 100 meq / lOOg. . from 0 to 10% of an alpha-omega-dihydrogenated oil, where the proportion in the hydrogen groups is between 30 and 300 meq / lOOg. . from 1 to 10% of a polyhydrogenated oil where the proportion of the hydrogen groups is between 100 and 1600 meq / lOOg. . preferably an adhesion promoter: from 0 to 5% of a mixture of silanes chosen from the range of unsaturates and epoxies; from 0 to 3% of a metal chelate and / or alkoxide; of a polyaddition catalyst with a proportion of 2 to 50 ppm of platinum; . optionally a polyorganosyl-xano resin having vinyl residues, in particular resin of the MDQ structure.

Preferred formulas for polycondensation are in general, an association: from 0 to 80% of a colloidal silica dispersion in a hydroxylated silicone oil. Silica is a reinforcing filler, with a specific surface area comprised between 50 and 400 m / g; there are between 10 and 50% in the dispersion. . from 10 to 90% of an alpha, omega-dihi-hydroxylated oil where the proportion of the hydroxyl groups is between 1 and 20 meq / lOOg. . from 10 to 40% of an MQ resin where the proportion of the hydroxyl groups is between 30 and 200 meq / lOOg. . preferably an adhesion promoter: from 0 to 5% of a silane selected from the range of amines and epoxides; . from 1 to 10% of a polycondensation catalyst. The present invention also has for its object a method for the preparation of an aqueous polyorganosiloxane emulsion of the type described above, in which the formula of the polyorganosiloxane precursor of the elastomer, comprising a polydiorganosiloxane, preferably a mineral filler, a catalyst and optionally a crosslinker, it is prepared ready, emulsified in an aqueous solution of protective hydrocolloid. In the case of the two component precursor formula, each part of the previously prepared formula is emulsified in its part of aqueous hydro-collide protective solution, subsequently the obtained emulsions are conserved separately. If necessary, a refinement of the emulsion can be carried out by means known per se, such as a grinder. The subject of the present invention is also a method of coating a textile or analog material, with the aid of an aqueous polyorganosiloxane emulsion as defined above, generally by emulsifying a polyorganosiloxane formula as defined previously, or as obtained by the above method, process in which an emulsion layer is applied on one or both sides of the textile material, then reticulated, in order to obtain a coated textile material, on at least one of its faces, of an elastomer layer, preferably 2 less than 40 g / m, mainly comprised between 2 5 and 40 g / m. In the case of two-component emulsion, the method comprises a previous step consisting in the mixing of two components. The coating step can be carried out mainly by means of a doctor blade, in particular by means of a scraper on a cylinder, an air scraper and a scraper on a carpet or a mat, or by means of rolling, that is to say, the action of squeezing between two rolls, or even by means of a buffing roller, table rotary, reverse roll (reverse roll), transfer, spray. It is possible to coat one or both sides of the textile material, the covering of the two faces is thus advantageously carried out by beating after the impregnation of the fabric with the emulsion. For a coating on two faces, by rolling, the fabric is preferably presented vertically between the two rollers where the emulsion is deposited continuously. For a single-sided coating by beading, the fabric is more horizontally placed between the rollers. After the passage between the rollers, the fabric is uniformly coated with a thin layer of emulsion. The drying and crosslinking is then carried out, preferably by heat or infrared rays, mainly from 30 seconds to 5 minutes, at a crosslinking temperature without exceeding the degradation temperature of the substrate.

The doctor blade is intended for coating on one side only. The emulsion is continuously deposited on the upper side of the fabric, then passes over the doctor blade, "before drying and crosslinking as described above." The present invention also has as an objective the textile or coated materials according to the present invention. This includes, in particular, bags or inflatable bags "airbag", glass braids, conveyor belts, fireproof or insulating fabrics, compensators, awnings and clothing, covered in accordance with the invention. The invention will now be described with more detail with the help of non-limiting embodiments.

Coating procedure 2 «a) By scraper on cylinder.

The scraper is regulated to the minimum thickness (between 0 and 5 μm) above the fabric, so that it can barely pass between the doctor blade and the cylinder.

~ .. The emulsion is deposited continuously on the upper face of the fabric before passing under the doctor blade. The tissue is then passed through a 1 minute oven at 150 ° C. b) By grooving (squeezed between two rollers).

The pressure of the rollers is regulated at 2 bars. Whether the fabric arrives vertically between the two rollers where the emulsion is deposited continuously, the fabric is impregnated on both sides at the exit of the ridillos, or the fabric arrives horizontally between the rollers and the emulsion is deposited at continuous on the upper face of the fabric that is coated on a single face after the passage between these rollers. The tissue is then passed through a 1 minute oven at 150 ° C. The tissues are weighed before and after the coating to measure the weight deposited.

Validation of good cross-linking and adhesion on the tissue after coating.

In the first approach, it is verified if the coated fabric has a dry touch after drying at the exit of the oven. The level of crosslinking and adhesion of the elastomeric backstop is evaluated simultaneously by means of a wrinkling test according to the norm NF G 37,110 (wrinkling behavior or "scrub test"). Cross-linking and adhesion are correct if 200 wrinkles are achieved.

Example of polyaddition I - In the presence of a load Preparation of parts A and B of the alastomer This operation is performed in an agitator arm mixer, laboratory. The following are mixed: * part A 505 g of a dispersion at 30% by weight of hydrophobic colloidal silica in the silicone oil; 2 developed silica of 300 m / g; alpha.omega divined oil with a titre of 15 meq Vi / 100 g 417.6 g of alpha.omega-divinylated oil with a titre of 7 meq Vi / 100 g 25.2 g of alpha, omega-dihydrogenated oil with a titre of 190 meq H / 100 g 40.5 g of polyhydrogenated oil with a titre of 160 meq H / 100 g 11.1 g of vinyltrimethoxysilane 0.6 g of ethynylcyclohexanol * part B 521.7 g of a dispersion at 30% by weight of hydrophobic colloidal silica in silicone oil; 2 developed silica of 300 m / g and alpha, omega divined oil with a titre of 15 meq Vi / 100 g 431 g of alpha, omega-divinillated oil with the title of 7 meq Vi / 100 g 45 g of butyl titanate 2.3 g of platinum catalyst with a titer of 12% by weight of platinum.

Emulsification of parts A and B of the elastomer The emulsification is carried out in a laboratory reactor by emptying the silicone phase in the portion of its weight of polyvinyl alcohol solution. After the mixture of the formula is completed with the rest of the water. The stirring is continued to refine the emulsion. * emulsion 500 g of part A 475 g of water 25 g of APV 25 / l40, ie viscocity 25 and ester index 140, marketed by Rhone Poulenc under the trademark Rhodoviol * emulsion B 500 g of part B 475 g of water 25 g of APV 25/140 Put in operation Emulsions A and B are associated at the time of their use at the rate of: 100 g of emulsion A 10 g of emulsion B II - In the absence of charge * Preparation of parts A and B of the elastomer reinforced with a silicone resin Part A 300 g of alpha, omega-divinylated oil at 3 meq Vi / 100 g 150 g of alpha.omega-divinylated oil at 5 meq Vi / 100 g 480 g of vinylated polysiloxane resin at 22 meq Vi / 100 g of viscosity 3.8 Pa.s 50 g of polyhydrogenated oil at 690 meq H / 100 g 10 g of vinyltrimethoxysilane 10 g of gamma-glycidoxypropyltrimethoxysilane 0.25 g of ethynylcyclohexanol part B 363 g of alpha, omega-divinylated oil at 3 meq Vi / 100 g; 145 g of alpha, omega-divinylated oil at 5 meq Vi / 100 g 446 g of vinylated polysiloxane resin at 22 meq Vi / 100 g of viscosity 3.8 Pa.s 40 g of butyl titanate 1.8 g of catalyst with titre of 12 % platinum * Emulsification as in I, with 500 g of part A 485 g of water 15 g of APV 500 of part B 485 g of water 15 g of APV * Start up: Mix with a proportion of 100 g of emulsion A + 10 g of emulsion B.

* Test results on polyamide fabric: with 22 g / m deposited: 400 wrinkles Example of polycondensation Preparation of parts A and B of the elastomer This operation is performed in a mixer with agitator arm, laboratory. They are mixed: * Part A 500 g of dispersion at 35% by weight of hydrophobic colloidal silica in silicone oil; 2 developed silica of 300 m / g; Hydroxylated oil with titre of 2 meq 0H / 100 g 375 g of alpha, omega-dihydroxylated oil with title meq OH / 100 g 125 g of a MQ silicone resin with a titre of 55 meq 0H / 100 g * Part B 100 g of d-lactide d-octil-tin Emulsification of parts A and B of the elastomer The emulsification is done in a laboratory reactor by emptying the silicone phase in the portion of its weight of polyvinyl alcohol solution. After the mixing of the formula is completed with the rest of the water. The stirring is continued to refine the emulsion.

* Emulsion A 500 g of part A 475 g of water 25 g of APV 25/140 * Emulsion B 500 g of part B 480 g of water 20 g of APV 25/140 Put in operation Emulsions A and B are associated at the time of use at the rate of: 100 g of emulsion A 5 g of emulsion B Results Three coating procedures were carried out: - RC: scraper on cylinder - IF: impregnation by beating - BC: coating of one face per cylinder (variant of beating). 1. On polyamide fabric 6.6 470 dtex 21x21 threads / cm, destemmed with: PA = polyaddition formula with loading of the previous example PC = Polycondensation formula of the previous example Crosslinking: 1 minute at 150 ° C.

Process RC IF BC RC RC Emulsion PA PA PA PC PA Appearance dry dry dry dry 2 Weight deposited (g / m) 25 20 20 20 40 NB wrinkles 500 200 200 200 600 The polyamide fabric is adapted for the manufacture of inflatable bags "airbag". The results with the emulsions loaded according to the invention show that a product with a thin coating layer is obtained and that it has properties compatible with the use of inflatable bags. 2. On glass fabric 230 g / i Process RC Emulsion PA Crosslinking 1 minute at 150 ° C Dry appearance Deposited weight 20 g / m 'Good adhesion The rubbing test is not adapted on the glass fabric, the adhesion is good when the coating resists the action of a prolonged scraping with the help of a metal spatula. In addition, the coating of the glass fabric is possible without de-screening of this fabric.

Claims (30)

1. An aqueous emulsion of polyorganosiloxane, mainly for the coating of textile or similar materials, comprising a formula of polyorganosiloxane precursor of the elastomer, comprising a polydiorganosiloxane, preferably a mineral filler, a catalyst and optionally a crosslinker, this formula forms the phase of silicone and is devoid of surfactant, characterized in that the organopolysiloxane formula is an emulsion in an aqueous solution of protective hydrocolloid, and because this emulsion is obtained by direct emulsification of the complete organopolysiloxane formula in the aqueous solution of protective hydrocolloid.

2. The emulsion according to claim 1, characterized in that the protective hydrocolloid is a polyvinyl alcohol (APV) or a mixture of APV.

3. The emulsion according to claim 2, characterized in that the aqueous solution of APV has a dynamic viscosity type (n,) comprised between 5 and 40 mPa.s, preferably between 10 and 30 mPa.s, and a higher ester index or equal to 80, preferably to 100 and mainly comprised between 120 and 200.

4. The emulsion according to claim 1, characterized in that the protective hydrocolloid is a sulfonated polyester, dispersible in water.

5. The emulsion according to claim 4, characterized in that the sulfonated polyester 0 dispersible in water has a number average molecular mass between 10,000 and 35,000, an acid number below 5 mg KOH / g, a sulfur content between 0.8 and 2% by weight, preferably between 1.2 and 1.8% .

6. The emulsion according to claim 4 or 5, characterized in that the sulfonated polyester soluble in water is a sulfonated polyethylene terephthalate. or

7. The emulsion according to any of claims 1 to 6, characterized in that the silicone phase / protective hydrocolloid phase ratio is chosen to have a dry extract ratio between 10 and 60, preferably 5 between 40 and 60.

8. The emulsion according to any of claims 1 to 7, characterized in that the aqueous solution of hydrocolloid potector further comprises a surfactant, preferably a non-ionic surfactant.

9. The emulsion according to claim 8, characterized in that the surfactant is a polyethoxylated fatty alcohol.

10. The emulsion according to claim 8 and 9, characterized in that the proportion of surfactant / hydrocolloid protector is between 0 and 10%.

11. The emulsion according to any of claims 1 to 10, characterized in that the organopolysiloxane formula is chosen from the group formed of the formulas for cold vulcanizable, polyaddition or polycondensation elastomer.

12. The emulsion according to claim 11, characterized in that the polyorganosiloxane formula is a polyaddition or polycondensation formula and further comprises at least one polyorganosiloxane resin.

13. The emulsion according to claim 12, characterized in that the polyorganosiloxane formula is a polycondensation formula, and further comprises a hydroxylated resin.

14. The emulsion according to any of claims 1 to 13, characterized in that it comprises a charge selected from the combustion silicas and precipitated silicas.

15. The emulsion according to claim 14, characterized in that the silicas have a BET specific surface area of at least 50 m / g, mainly between 50 and 400 ra / g, and an average dimension of primary particles, lower than 0.1 micrometer, and a bulk density less than 200 g / 1.

16. The emulsion according to claim 15, characterized in that the silicas are treated with one or more organosilicon compounds.

17. The emulsion according to claim 16, characterized in that the silicas are treated with one or more organosilicon compounds selected from the group consisting of methylpolysiloxanes such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, methylpolysilazanes such as hexamethyldisilazane, hexamethylcyclotrisilazane, chlorosilanes such as dimethyldichlorosilane, triraethylchlorosilane, methylvinyl dichlorosilane, dimethylvinylchlorosilane, alkoxysilanes such as dimethyldimethoxysilane, dimethylvinylethoxysilane, and trimethylmethoxysilane.

18. The emulsion according to any of claims 14 to 17, characterized in that the filler further comprises one or more mineral fillers such as crushed quartz, calcined clays and diatomaceous earths.

19. The emulsion according to any one of claims 14 to 18, characterized in that the formula comprises 0.5 to 50% by weight, preferably 10 to 25% by weight, based on the weight of the organopolysiloxane constituent.

20. The emulsion according to any of claims 1 to 19, characterized in that the organopolysiloxane formula further comprises one or more adhesion promoters.

21. The emulsion according to claim 20, characterized in that the organopolysiloxane formula is a polyaddition formula, and in that the adhesion promoter (s) are selected from the group consisting of: - alkoxylated organosilanes containing, per molecule, at least an alkenyl group having 2 to 6 carbon atoms, the organosilicon compounds comprising at least one epoxy radical, and the metal chelates M and / or the metal alkoxides of the general formula: M (0J), with n = > valence of M, and J = linear or branched alkyl of 1 to 8 carbon atoms, M being chosen from the group consisting of: TI, Zr, Ge, Li, Mn, Fe, Al, Mg.

22. The emulsion according to claim 20, characterized in that the organopolysiloxane formula is a polycondensation formula, and in that the adhesion promoter or promoters are chosen from the group possessing the amino silanes, such as the aminoorganosilanes, aminoorganopolysiloxanes, guanidi- noorganosilanes and epoxidized silanes.

23. The emulsion according to any one of claims 1 to 12 and 14 to 21, characterized in that it comprises, as a polyaddition formula: from 0 to 80% of a colloidal silica dispersion in a divinilated silicone oil, at the rate of 10 to 60% of silica in the dispersion, from 10 to 90% of an alpha, omega-divinilado oil where the proportion of vinyl groups is between 2 and 100 meq / 100 g,. from 0 to 10% of an alpha, omega-dihydrogenated oil, where the proportion of hydrogen groups is between 30 and 300 meq / 100 g,. from 1 to 10% of a polyhydrogenated oil where the proportion of hydrogen groups is between 100 and 1600 meq / 100 g,. preferably an adhesion promoter: from 0 to 5% of a mixture of silanes chosen from the gamma of unsaturates and epoxides; from 0 to 3% of a metal chelate and / or alkoxide,. of a polyaddition catalyst at a ratio of 2 to 50 ppm of platinum, optionally a polyorganosiloxane resin having vinyl residues, in particular resin of MDQ structure.

24. The emulsion according to any of claims 1 to 20 and 22, characterized in that it comprises, as a polycondensation formula: from 0 to 80% of a colloidal silica dispersion in a hydroxylated silicone oil, at a ratio of 10 to 50 % of silica in the dispersion, from 10 to 90% of an alpha, omega-dihydroxylated oil, where the proportion of hydroxyl groups is between 0.1 and 20 meq / 100 g, from 10 to 40% of an MQ resin where the ratio of hydroxyl groups is between 30 and 200 meq / 100 g. . preferably an adhesion promoter: from 0 to 5% of a silane selected from the range of amine-two and epoxy,. from 1 to 10% of a polycondensation catalyst.

25. An equipment, intended for carrying out an aqueous polyorganosiloxane emulsion according to any of claims 1 to 24, comprising two parts of the polyorganosiloxane formula wherein the meeting forms the organopolysiloxane formula precursor of the elastomer, each part of the emulsion formula in an aqueous solution of protective hydrocolloid, each emulsion being obtained by direct emulsification of the formula part in an aqueous solution of protective hydrocolloid.

26. The method of preparing a polyorganosiloxane aqueous emulsion according to any of claims 1 to 24, characterized in that the polyorganosiloxane precursor formula of the elastomer is prepared, and after emulsification in an aqueous solution of protective hydrocolloid.

27. The method according to claim 26, characterized in that in the case of a two component precursor formula, each part of the previously prepared formula is emulsified in its part of aqueous solution of protective hydrocolloid, and the obtained solutions are conserved separately.

28. The process of coating a textile or similar material with the aid of an aqueous polyorganosiloxane emulsion according to any of claims 1 to 24 or a device according to claim 25, characterized in that an emulsion layer is applied on a or the two faces of the textile material, then reticulate in order to obtain a coated textile material, on at least one of its faces, with an elastomer layer, preferably 2 less than 40 g / m, mainly comprised between 2 5 and 40 g / m.

29. The process according to claim 28, characterized in that the coating is carried out by scraper or by beating.

30. The product that can be obtained by the process according to claim 28 or 29. SUMMARY An aqueous polyorganosiloxane emulsion is described, mainly for coating textile or analogous materials, comprising an organopolysiloxane formula, precursor of the elastomer, comprising a polydiorganosiloxane, preferably a mineral filler, a catalyst and optionally a crosslinker, in the absence of surfactant in this formula, which is characterized by the fact that the organopolysiloxane formula is an emulsion in an aqueous solution of protective hydrocolloid, and because this emulsion is obtained by direct emulsification of the complete organopolysiloxane formula in the solution aqueous hydroco-loide protector. The protective hydrocolloid is preferably a polyvinyl alcohol (APV) or a mixture of APV. The method of relative preparation, the coating process with the aid of these emulsions and the products coated in this way are also described.