EP1828280A1

EP1828280A1 - Polyether silyl aqueous dispersion

Info

Publication number: EP1828280A1
Application number: EP05850060A
Authority: EP
Inventors: Michel Feder; Marc Chaussade
Original assignee: Bluestar Silicones France SAS
Current assignee: Elkem Silicones France SAS
Priority date: 2004-12-23
Filing date: 2005-12-23
Publication date: 2007-09-05
Also published as: US20090131567A1; KR20070117536A; WO2006070132A1; FR2880026B1; FR2880026A1; JP2008525561A; CN101189280A

Abstract

The invention concerns an aqueous dispersion capable of crosslinking by condensation into elastomer by eliminating water in the presence of a polycondensation catalyst, comprising, dispersed in a continuous aqueous phase, an organic phase containing at least one polymer including a polyether chain, optionally branched, bearing, per molecule, at least one terminal alkoxysilyl unit and at least two -OR groups borne by one or more silicon atoms, the dispersion containing further an emulsifier adapted to the formation of the dispersion and a polycondensation catalyst. The polymer preferably comprises at least two terminal alkoxysilyl units corresponding to the following formula (a): (R1 - O)n (R2)m Si -, wherein n is 1, 2 or 3 and m is 0, 1 or 2, with n + m = 3, the R1 groups, mutually identical or different, the R2 groups, mutually identical or different to R1, are selected from the linear or branched C1-C8 alkyl groups. The invention also concerns a mixed dispersion containing a silylated polyether organic phase and a silicone-based organic phase.

Description

AQUEOUS POLYETHER SILYL DISPERSION

The present invention relates to compositions based on silylated polyether having alkoxysilyl units capable of crosslinking into an elastomer. US Pat. No. 3,971,751 discloses silylated polyethers with alkoxysilyl units, commonly known as MSP or MS Polymers, which, in the presence of a condensation catalyst, can crosslink into elastomer under the action of humidity and at room temperature. The elastomer has adhesiveness and elasticity properties making it suitable for use in the field of sealing. The anhydrous compositions based on silylated polyether are extremely sensitive to ambient humidity, which requires taking precautions during their production and storage. They are also difficult to implement because cleaning tools, surfaces, etc. requires the use of organic solvents. Among the other disadvantages of these compositions is the release of alcohol, usually methanol.

The object of the present invention is to provide novel compositions capable of solving the problems of the anhydrous compositions based on silylated polyethers mentioned above, while at the same time making it possible to generate elastic and adherent elastomers, which can in particular be used in the field of mastics and analogs used for example in jointing in the building industry, the automotive industry or the household electrical appliance, or in the field of elastic coatings and paints.

Despite their high water reactivity, it has been unexpectedly found that stable aqueous dispersions based on silylated polyethers can be obtained which fully satisfy the objectives of the invention. In particular, these dispersions are convenient and easy to use, the cleaning being carried out with water, and, as an additional advantage, these dispersions can be diluted with water to reduce the viscosity.

The subject of the invention is thus an aqueous dispersion capable of crosslinking by elastomer condensation by elimination of water in the presence of a polycondensation catalyst, comprising, dispersed in a continuous aqueous phase, an organic phase containing at least one polymer comprising a polyether chain, optionally branched, carrying, per molecule, at least one terminal alkoxysilyl unit and at least two -OR groups carried by one or more silicon atoms (by definition, a silicon atom of an alkoxysilyl group), the dispersion still containing an emulsifier adapted to the formation of the dispersion. A condensation catalyst may be present in the organic phase or it may be added to a non-catalyzed dispersion at any time during the manufacture or processing of the final dispersion.

The polymer preferably comprises: at least two, more preferably at least three -OR groups borne by one or more (different) silicon atoms, and / or at least two terminal alkoxysilyl units, it being understood that when the polymer is branched, the branching, of polyether nature, may carry a terminal alkoxysilyl unit. In -OR, R may represent hydrogen or a linear or branched, C1 to C8, better still C1 to C3 alkyl group, more preferably methyl. Generally, the committed polyether polymer contains exclusively or mainly -OR in which R is an alkyl as described above. Then, within the organic phase, a certain degree of hydrolysis of the alkoxy -Oalkyl groups can occur, leading to hydroxy -OH groups. The case where R is hydrogen can therefore result from such hydrolysis, or it was directly possible to engage a polyether bearing -OH groups bound to the terminal silicon atoms.

The alkoxysilyl unit or units, which carry, by definition, said -OR groups may in particular satisfy the following formula (a): (R ¹ - 0) _n (R ² ) _m Si - in which n is 1, 2 or 3 and m is 0, 1 or 2, with n + m = 3; preferably, n is 2 or 3; the groups R ¹ , which are identical to or different from each other, and R ² , which are identical to or different from each other, and of R ¹ , are chosen from linear or branched alkyl groups, in C 1 to C 8 and better still in C 1 to C 3, more preferably all of them methyl.

Generally, the constituent units of the polyether chain intended to form the organic phase are, or include, a polyoxyalkylene structure:

- R ⁴ - O - wherein the R ⁴ groups, identical or different in the same chain, are divalent alkylene groups C1 to C6, preferably C3 or C4. It can therefore be polymers with a single pattern or with several units, eg block-copolymers and random polymers. Preferably, the polyoxyalkylene structure is essentially or exclusively of the R ⁴ = C 3 or C ⁴ , more preferably polyoxypropylene (C 3) type. As already mentioned, the polyether may be branched, that is to say comprise one or more polyether side chains having the same structure general - R ⁴ - O -, which may optionally be terminated by an alkoxylilyl unit of formula (a).

The termini of the polyether chains, when they are not of the alkoxysilyl type, can in particular be of the --CH ₂ OH type. In the presence of -OH groups, resulting from hydrolysis in situ, or provided by the original polyether, does not exclude a certain degree of crosslinking between polyether chains. The composition according to the invention may therefore also comprise a certain proportion of polyether chains of hydroxysilyl units and chains crosslinked together by Si - O - Si bonds. The dispersion may contain more than one type of these polymers.

On the other hand, the polymer (s) present may be further characterized in that they have a molecular weight of between 500 and 15,000, preferably between 3,000 and 12,000.

It is preferable to engage polymers which are liquid at room temperature (15-25 ^° C.). However, polymers whose glass transition temperature is slightly higher than ambient temperature can be used, and it may be desirable to liquefy them by mixing with a plasticizer. As a plasticizer, mention may be made of the low volatility solvents of polyethers (phthalates, alkylbenzenes, etc.). The organic phase may also comprise a crosslinking agent, in particular a crosslinking silane. In particular, such an agent is preferably present when the polymer has only 2 -OR groups per molecule. It can be a silane of formula

(R ") _u If X ₍₄ _ _u) in which the R" groups, which are identical or different, are monovalent organic radicals, in particular methyl or vinyl, u is equal to 1 or 0, the X, which are identical or different, are condensable and / or hydrolyzable organic groups chosen from:

- OH ; alkoxy or alkenyloxy containing from 1 to 10 carbon atoms; aryloxy containing from 6 to 13 carbon atoms;

acyloxy group containing from 1 to 13 carbon atoms;

cetiminoxy group containing from 1 to 8 carbon atoms;

amino or amido-functional group containing from 1 to 6 carbon atoms bonded to silicon via an Si-N bond. Such silanes are described in particular in US Pat. No. 3,294,725; US-A-4,584,341; U.S. Patent 4,618,642; US-A-4,608,412; US-A-4,525,565; EP-A-387157; EP-A-340,120; EP-A-364,375; FR-A-1,248,826; FR - 1 023477.

By way of examples, mention may be made of the following alkoxysilanes: Si (OC ₂ H ₅ ) ₄ ; CH ₃ Si (OCH ₃ ) ₃ ; CH ₃ Si (OC ₂ H ₅ ) 3; (C ₂ H ₅ O) ₃ Si (OCH ₃ );

CH ₂ = CHSi (OCH ₃ ) ₃ ; CH ₃ (CH ₂ = CH) Si (OCH ₃ ) ₂ ; CH ₂ = CH (OC ₂ H ₅ ) ₃ ; CH ₂ = CHSi [ON = C (CH ₃ ) C ₂ H ₅ ]; CH ₃ Si [CH = C (CH ₃ ) ₂ ] ₃ CH ₃ Si [-C (CH ₃ ) = CH ₂ ] ₃ ; methyltri (N-methylacetamidosilane); rnéthyitris (cyclohéxylaminosilane). These silanes can be employed in amounts of the order of 0 to 10 parts by weight, preferably of the order of 0 to 5 parts by weight per 100 parts of polyether.

Polycondensation catalysts are well known to those skilled in the art; mention may be made of carboxylic acid salts, alkoxides, chelates and halides of metals such as lead, zinc, zirconium, titanium, iron, barium, calcium, manganese, vanadium, bismuth, antimony, aluminum and especially tin, and mixtures thereof; or alternatively nitrogen or amine compounds. We can cite more particularly:

. the reaction products of tin dicarboxylates and ethyl polysilicate (US Pat. No. 3,862,919)

. the reaction products of dibutyltin diacetate and an alkyl silicate or an alkyltrialkoxysilane (BE-A-842 305). tin bischelates (EP-A-147,323; 235,049)

. diorganotin dicarboxylates (GB-A-1,289,900). They can be used in amounts of up to about 3 parts by weight, preferably about 0.05 to 1 part by weight per 100 parts of polymer. The catalyst may be dispersed in the organic phase before emulsification, or may be added to the dispersion, optionally in the form of a catalyst emulsion.

Emulsifiers are known compounds. They may be liquid or solid, and may be chosen from surfactants, water-soluble polymers such as polyvinyl alcohol and solid particles forming a Pickering emulsion or the like.

The surfactants used are preferably nonionic; examples that may be mentioned include alkoxylated fatty acids, polyalkoxylated alkylphenols, polyalkoxylated fatty alcohols, polyalkoxylated or polyglycerolated fatty amides, polyglycerolated alcohols and alpha diols, ethylene oxide-propylene oxide block polymers, and the like. as well as alkylglucosides, alkylpolyglucosides, sucroethers, sucroesters, sucroglycerides, sorbitan esters, etc., and the ethoxylated compounds of these sugar derivatives, etc. The anionic surfactants may be chosen from alkylbenzene sulphonates, alkyl sulphates, alkyl ether sulphates, alkylaryl ether sulphates, dioctylsulphosuccinates and alkali metals, and the like.

The surfactant or the mixture of surfactant (s) used may have an HLB of the order of 11 to 15, in particular when the surfactant is nonionic. The weight ratio water / water + surfactant (s) is a function of the viscosity of the polymer phase and the nature of the (mixture of) surfactant (s); this ratio is for example of the order of 20/100 to 70/100, preferably of the order of 25/100 to 60/100.

The dispersion may contain a filler, preferably in the aqueous phase. It may be a reinforcing filler, a semi-reinforcing filler or a filler, or a mixture of at least two types. Among the reinforcing fillers, mention will first be made of siliceous fillers such as colloidal silica and precipitated silica. Examples of semi-reinforcing fillers or stuffing are natural stuffing calcium carbonate, semi-reinforcing industrial carbonates, diatomaceous earths, ground quartz, hydrated alumina, magnesium hydroxide, carbon, titanium dioxide, aluminum oxide, vermiculite, zinc oxide, mica, talc, iron oxide, barium sulfate, slaked lime. The particle size of these charges is generally of the order of 0.001 to 300 μm.

In the preferred embodiments, a reinforcing filler, in particular a colloidal silica, and / or a semi-reinforcing filler, in particular based on carbonate, will be present.

Industrial carbonates can be used as semi-reinforcing fillers. There may be mentioned precipitation carbonates, eg precipitation calcium carbonate. Under these conditions, one can have access to carbonates whose average particle size is generally less than 1 μm, in particular less than or equal to 0.5 μm. These precipitation carbonates can then have a surface BET specific high, greater than 5 m ² / g. Preferably, such carbonates having an average particle size less than or equal to 0.1 μm, more preferably between 0.01 and 0.1 μm, and preferably a BET specific surface area ranging from 10 to 70 m ² , are preferably used. / g, preferably from 15 to 30 m ² / g. Particularly preferably, as is known per se for improving the dispersibility of carbonates in a hydrophobic medium, the carbonates according to the invention are treated in particular with carboxylic fatty acids such as stearic acid.

Different types of amorphous silica may be used as reinforcing filler, namely precipitated silicas and colloidal silicas. Of course, it is also possible to use blends of different silicas. Their BET surface area is generally greater than 40 m 2 / g and preferably between 100 and 300 m ² / g.

A charge dispersing agent may be provided, such as, for example, alkali metal polyacrylates having a molecular weight of less than 5,000, mineral phosphates, etc., in amounts of up to 10% by weight of the final aqueous dispersion.

The dispersion may also comprise at least one adhesion promoter, preferably chosen from amino or non-amino organosilicon compounds, preferably silanes, whether or not aminated, bearing at the same time:

(1) one or more hydrolysable groups bonded to the silicon atom and

(2) one or more organic groups containing radicals chosen from the group of amino (or diamino), (meth) acrylate, epoxy, alkenyl (typically 2 to 6 C) and / or alkyl (typically 1 to 8 C) radicals; ).

By way of example, one of the following silanes, or a mixture of at least two of them: 3-aminopropyltriethoxysilane, may be used,

beta-aminoethyl-gamma-aminopropyltrimethoxysilane-beta-aminoethyl-gamma-aminopropylmethyldimethoxysilane

3-aminopropyltrimethoxysilane,

vinyltrimethoxysilane,

3-glycidyloxypropyltrimethoxysilane,

3-methacryloxypropyltrimethoxysilane, propyltrimethoxysilane,

methyltrimethoxysilane, retyltrimethoxysilane,

vinyltriethoxysilane,

3-aminopropylmethyldimethoxysilane,

3-aminopropylmethyldiethoxysilane, methyltriethoxysilane, propyltriethoxysilane,

tetraethoxysilane,

tetrapropoxysilane, tetraisopropoxysilane, or hydrolysis and condensation products, such as polyorganosiloxane oligomers containing such organic groups at a content greater than 20%.

The adhesion promoter will partition between the aqueous and organic phases depending on its solubility parameters. Among the preferred methods, there will be mentioned amino silanes, such as aminopropyltriethoxysilane, and aqueous silanes sold by Degussa under the name Hydrosyl® HS.

It is also possible to use, as adhesion promoter, a silicate bearing one or more hydrolyzable groups, in particular alkyl groups, typically from 1 to 8 C. Mention may be made of propyl silicates, isopropyl silicates and ethyl silicates. The silicates can be polycondensed or not.

For the adhesion promoter as for the condensation catalyst, it is conceivable to have a two-component product, on the one hand with the dispersion of the organic phase containing the polyether, and on the other hand, with a preparation of catalyst and / or promoter, eg in dispersed or emulsified form, the two parts being able to be mixed and to make it possible to produce the elastomer during drying.

The dispersions according to the invention can also be defined as those which are capable of crosslinking by elastomeric condensation by elimination of water in the presence of a polycondensation catalyst, and which are capable of being obtained by dispersion, in a single phase. continuous aqueous phase of an organic phase containing at least one polymer comprising a polyether chain, optionally branched, bearing at least one terminal alkoxysilyl unit and at least two-OR groups borne by a silicon atom, optionally a polycondensation catalyst, the dispersion still containing an emulsifier adapted to the formation of the dispersion. It has already been mentioned above, that the exact composition can evolve over time, with reactions of hydrolysis of the alkoxy -Oalkyl groups to hydroxyl groups and optionally inter-chain grafting. The dispersions that can thus be obtained thus comprise -Oalkyl and / or -OH groups in variable proportions, and optionally polyether chains that are more or less crosslinked with each other. A condensation catalyst may be present in the organic phase or it may be added to a non-catalyzed dispersion at any point in the manufacture or processing of the final dispersion.

According to a feature of the invention, the dispersion is as obtained after partial or complete hydrolysis of -Oalkyl to -OH and removal, e.g. devolatilization, of all or part of the alcohol, e.g. methanol, product. A low alcohol content dispersion, e.g. methanol, is obtained and subsequently, upon drying, will release little alcohol.

The "oil-in-water" emulsion of the organic phase can be carried out by introducing this phase into a water + surfactant (s) mixture or preferably by introducing the water into an organic phase mixture. + surfactant (s) and kneading in single or multiple screw extruder type mixers, turbine planetary mixers, static mixers, blade, propeller, arm, etc. mixers, a temperature of the order of 10 to 50 ° C.

The dry extract of the dispersions according to the invention may represent from 40 to 90%, preferably from 70 to 87% by weight of the total dispersion. For coating applications (in English "coating", the dry extract is advantageously between

70 and 80%. For mastic or cold-glue type applications, the solids content is advantageously greater than 80%.

As already mentioned, it is possible to allow a certain degree of hydrolysis to take place and then to eliminate, e.g., by devolatilization, the alcohol produced by this hydrolysis.

The dispersion according to the invention may furthermore comprise a second organic phase containing a silicone composition of the type conventionally used in aqueous dispersions based on silicone oils which can crosslink by elimination of water, of elastomer that can be used in buildings, automotive industry and household appliances, particularly in the form of seals, paints, etc. The complex dispersion according to the invention can simply be the result of the mixing between a first polyether polymer dispersion and a second silicone composition dispersion. It can also result from simultaneous or successive emulsification of the two organic phases. Can be used, in the context of this invention, the usual silicone compositions or silicone dispersions, for example those described in FR-A-2 697 021 and FR-A-2 780 067. These compositions contain a reactive silicone oil, that is to say carrying at least two condensable functional groups, for example chosen from:

. OH group (preferred mode); . alkoxy or alkenyloxy group containing from 1 to 10 carbon atoms;

. aryloxy group containing from 6 to 13 carbon atoms; . acyloxy group containing from 1 to 13 carbon atoms; . cetiminoxy group containing from 1 to 8 carbon atoms; . amino- or amido-functional group containing from 1 to 6 carbon atoms, bonded to silicon via an Si-N bond.

Preferably, a hydroxylated silicone oil will be chosen as the base. Such an oil may be an α, ω-hydroxylated polydiorganosiloxane (POS) of formula:

the groups R 1, which may be identical or different, each represent a substituted or unsubstituted, aliphatic, cyclanic or aromatic saturated monovalent hydrocarbon radical C 1 to C 13;

n has a value sufficient to give the POS A 'a dynamic viscosity at 25 ° C ranging from 500 to 1,000,000 mPa.s.

The organic silicone phase may comprise the usual additives, and in the first place, a polycondensation catalyst chosen from those described above for the polyether phase. It will preferably be the same catalyst. The quantities involved will also be of the same order of magnitude.

As regards the emulsifier, this will also meet the definition given for the polyether phase, and will preferably be the same. The quantities involved will also be of the same order of magnitude.

A charge may also be provided. Preferably, the silicone phase comprises a reinforcing filler, semi-reinforcing or filler, or a mixture of at least two types. These charges are generally chosen from those described above for the polyether phase. Colloidal silicas and carbonate fillers are preferred. The quantities involved will also be of the same order of magnitude. The silicone phase may also comprise: a crosslinking agent and / or a crosslinking silane, eg as described above for the polymer dispersion, a hydroxylated or alkoxylated silicone resin,

a plasticizer for the organic phase, for example polydimethylsiloxane oils with a viscosity of the order of 300 to 10,000 mPa.s, dioctylphthalates, dialkylbenzenes, etc., optionally in aqueous emulsion, in amounts of 0 to 70 parts by weight per 100 parts by weight of oil (A '); and / or a charge dispersing agent for the aqueous phase, such as, for example, alkali metal polyacrylates having a molecular weight of less than 5,000, mineral phosphates, etc., in amounts of up to 10% by weight of the dispersion. final aqueous. When a silicone phase is present in the dispersion, the dry extract values mentioned above, which remain valid, are the summation of the solids content of the polyether phase and that of the silicone phase.

Generally, the silicone phase to polyether phase ratio in the dispersion will be between 0.1 and 10, preferably between 0.5 and 5. In the present application, the viscosity of the oils is a Newtonian dynamic viscosity at 25 ° C. measured at using a BROOKFIELD viscometer as specified in the AFNOR NFT 76102 standard of May 1982.

The BET surface area is determined according to the method BRUNAUER, EMMET, TELLER described in "The Journal of the American Chemical Society, Vol. 80, page 309 (1938) "corresponding to the AFNOR standard NFT 45007 of November 1987.

The invention also relates to elastomers obtainable by crosslinking by condensation by removal of water, in the presence of a polycondensation catalyst, a dispersion according to the invention.

The subject of the invention is also a kit comprising, separately in the same package, an aqueous dispersion according to the invention without a catalyst and a preparation of the condensation catalyst of the invention, for example in the form of an emulsion, these two parts being intended to be mixed before use.

The present invention will now be explained in more detail, using implementation modes taken as non-limiting examples. The making of a putty comprises two steps: the emulsification of the polyether oil or MSP oil in water (Example 1), and then the formulation of the final product (Examples 2, 3 and 4).

EXAMPLE 1 Production of a concentrated emulsion (MSP in water), emulsification step

The emulsification is done in a device with scraping blades and central agitator of the butterfly type (here a mixer Euromélange batch mixer). In a 10-liter jacketed vessel, the following are charged: MSP oil S303H® (KANEKA): 3000 g MSP polymer oil is a polypropoxy chain oil with silylated ends, functionalized methoxy, of average general formula:

- Rhodasurf® ROX surfactant from Rhodia Chimie (ethoxylated isotridecyl alcohol, with an average of 8 CH ₂ CH ₂ O units, at 85% active ingredient in water): 450g - Demineralized water: 525g

Stirred at: - Scraper at 60 rpm - Central butterfly at 400 rpm

The mixture is cooled by circulation of water in the jacket during the entire duration of the handling, so as not to exceed 40 ^° C. After about 2 minutes, a concentrated oil-in-water emulsion is obtained by phase inversion: the mixture takes a gel appearance, and acquires a threshold of flowability. The product is no longer flowing as was the starting oil. To verify that the phase inversion took place, a small sample was taken from the mixture and placed in a little demineralized water. It is observed a dissolution of the product in water, the emulsification has been successful (we have an oil-in-water emulsion).

Then poured slowly (in 5 min with stirring) an additional 3000g of MSP oil. After addition, stirring is continued for 5 minutes (still scraping at 60 rpm and throttle at 400 rpm). The particle size of the emulsion is then measured using a Coulter LS 130 granulometer, an average particle size of 0.4 μm is measured. The concentrated emulsion is packaged in an airtight container of 10 liters to avoid the loss of water which would harm the stability of the product. The solids content of the emulsion obtained is 91%.

Example 1a: Production of a concentrated emulsion (Silicone in water), emulsification step

The emulsification is done in a device with scraping blades and central agitator of the butterfly type (here a mixer Euromélange batch mixer). In a 10-liter double-jacketed tank, we charge:

Α, ω-hydroxylated polydimethylsiloxane oil having a viscosity of approximately 135,000 mPa.s: 2000 g

Surfactant (the same as in Example 1): 142 g

- Demineralised water: 66 g

Stirring at: - scraping at 60 rpm

central butterfly at 400 rpm The mixture is cooled by circulation of water in the jacket during the entire duration of the handling, so as not to exceed 40 ^° C. After about 2 minutes, an oil-in-oil concentrated emulsion is obtained. phase inversion water: the mixture takes on a gel appearance, and acquires a pourability threshold. The product is no longer flowing as was the starting oil. To verify that the phase inversion took place, a small sample was taken from the mixture and placed in a little demineralized water. It is observed a dissolution of the product in water, the emulsification has been successful (we have a silicone oil emulsion in water). The final dry extract of the product is 96% and the average particle size is 0.4 μm.

EXAMPLE 2 Formulation of an Emulsion MSP Putty

The constituents of the following formula are added successively in a 2 liter mixer, with very slow stirring during the entire handling. The mixer used is a LAB MAX® from MOLTENI, the rotation speed of the tools is 20 rpm, and the scraper is activated. Cold water circulates in the jacket for the duration of the handling.

MSP putty in

Emulsion component, little reinforced emulsion

Concentrated emulsion of MSP (eg 1) 465 465 Water 88 77 Na Coatex® polyacrylate dispersant P50 8 8 Socal® 312 treated carbonate, surface 120 60 specific 20 m ² / g (SOLVAY) 72% Omyacoat® slurry carbonate

200 100 carbonate in water (OMYA) Aminopropyltriethoxysilane hydrolyzed and 26 26 oligomerized in solution, Silquest VS 142 (OSI) Dioctyltin dilute 2 2 (emulsion of RHODIA CHEMISTRY)

TOTAL 909 g 738 g

FINAL DRY EXTRACT 77.5% 77.5%

The slow stirring is maintained until perfect homogeneity of the mixture. Degassing is then carried out under a vacuum of 50 mbar for about 20 minutes until the occluded air and volatiles have been evacuated. The product is then packaged in 310 mL polyethylene cartridges. The residual amount of methanol and methoxy groups is lower than in the starting MSP given the hydrolysis of methoxy in the presence of water and the devolatilization conditions used.

Example 3 Formulation of an MSP Hybrid Sealant / Emulsion Silicone

The process is the same as for Example 2.

* Description of the resin: it is a silicone resin consisting of MeSiO _{3/2 units} (about 68 mol%), Me ₂ SiO (about 21%) and Me ₃ SiOv ₂ (about 10%), of Mn = 1680 g / mole, ratio R / Si = 1.4, at 0.5% OH (by weight) and viscosity about 5 1000 mPa.s.

The slow stirring is maintained until perfect homogeneity of the mixture. Degassing is then carried out under a vacuum of 50 mbar for about 20 minutes until the occluded air and volatiles have been evacuated. The product is then packaged in 310 mL polyethylene cartridges. 10

EXAMPLE 4 Addition of an MSP Emulsion to an Emulsion Silicone Sealant (Rhodalis® 4000 or Revetosil® P40)

Rhodalis® 4000 (Trade Mark Revetosil® 4000) is a fluid formulation used for coating applications, and the main constituent of which is a silicone emulsion. By combining this product with an MSP emulsion (example 1), the properties of the final material are modified.

The MSP emulsion can be added directly to Rhodalis® 4000, with slow stirring (20 rpm). For 100 g of Rhodalis® 4000, 50 g of the MSP emulsion of Example 1 were added. 20.

EXAMPLE 5 Results The following tests are: DCH 81-2: emulsion MSP sealant (example 2) DCH 81-4: hybrid MSP / emulsion silicone sealant (example 3) 25 DCH 81-5: emulsion MSP sealant, few reinforced (example 2)

Qualitative adhesion tests

In order to carry out qualitative adhesion tests, a bead of product is deposited on the previously cleaned supports. After a cure time of 7

30 days (at 23 ° C and 50% RH = residual moisture), a manual coat is made after have made a detachment primer at the support / mastic interface. The results are expressed according to the type of rupture of the product cord:

RA if you have an adhesive break (the cord comes off the support)

RA + break with adhesive tendency, but requiring to apply a force to take off the cord

RA ++ breaking with adhesive tendency, but needing to apply a strong force to take off the cord

RC if there is a cohesive rupture (the cord breaks under the application of a very high force, without having taken off the support, even partially); in this case the adhesion on the support is optimal

ES = dry extract

Tracking Shore A hardness

Shore A hardness is measured using a ZWICK® durometer. It characterizes the penetration rate of a calibrated tip in a stack of 3 films 2 mm thick, crosslinked at 23 ° C and 50% relative humidity. The shore A hardness (DSA) of the film characterizes the progress of the crosslinking:

Shore hardness A '> DCH 81-2J DCH 81-4 DCH 81-5 ^ι _< - ύ '

DSA 1d 31 8 22

DSA 2d 38 11 26

DSA 3j 39 - -

DSA 4j - - -

DSA 5d - 17 28

DSA 6j 39 - - DSA 7d 40 18 28

Mechanical properties of emulsion sealants

The mechanical properties are measured using an INSTRON® dynamometer on H2 specimens punched in the elastomer obtained by drying 7 days of a film of 2 mm thick. The modulus at 100% elongation, elongation at break and tensile strength are noted:

Rhodalis 4000 +

Mechanical properties Rhodalis 4000 Emulsion MSP (40g + 20g)

Module 100% (MPa) 0.5 0.25

Elongation break (%) 423 663

Rupture resistance (MPa) 0.79 0.92

It can be seen that these emulsions can be diluted with water and that it is possible to clean the tools with water; that MSP polymer emulsions have a very low toxicity risk in that they release less methanol than conventional anhydrous MSP mastics; that hybrid silicone / MSP emulsion compositions lead to a final elastomer obtained after drying which is macroscopically homogeneous, despite the fact that the two polymers are incompatible (immiscible); and that the MSP emulsion improves the ultimate properties (elongation and breaking strength) of the aqueous silicone sealant.

It should be understood that the invention as defined by the appended claims is not limited to the particular embodiments set forth in the above description, but encompasses variants thereof that do not depart from the scope or spirit of the present invention. present invention.

Claims

An aqueous dispersion capable of crosslinking by elastomeric condensation by elimination of water in the presence of a polycondensation catalyst, comprising, dispersed in a continuous aqueous phase, an organic phase containing at least one polymer comprising an optionally branched polyether chain, carrying, per molecule, at least one terminal alkoxysilyl unit and at least two -OR groups carried by one or more silicon atom (s), the dispersion still containing an emulsifier suitable for forming the dispersion and a polycondensation catalyst.

2. Dispersion according to claim 1, wherein the polymer comprises at least two or at least three -OR groups carried by one or more silicon atom (s), and / or at least two terminal alkoxysilyl units.

3. Dispersion according to claim 1, wherein the polymer comprises at least one or at least two terminal alkoxysilyl units corresponding to the following formula (a):

(R ¹ - O) _n (R ² ) _m Si - wherein n is 1, 2 or 3 and m is 0, 1 or 2, with n + m = 3; the groups R ¹ , which are identical to or different from each other, and R ² , which are identical to or different from each other and from R ¹ , are chosen from linear or branched C ¹ to C ⁸ alkyl groups.

4. Dispersion according to claim 3, wherein n is 2 or 3.

5. Dispersion according to one of claims 1 to 3, wherein the constituent units of the polyether chain are, or include, the polyoxyalkylene structure:

- R ⁴ - O - wherein the R ⁴ groups, identical or different, are C1 to C6 divalent alkylene groups.

The dispersion of claim 5, wherein the R ⁴ are divalent C 3 or C ⁴ alkylene groups.

The dispersion of claim 5 or 6, wherein the polyether has one or more polyether side chains having the same structure. general - R ⁴ - O -, terminated by an alkoxysilyl unit having the following formula (a):

8. Dispersion according to one of claims 1 to 7, containing a polycondensation catalyst in the organic phase.

9. Dispersion according to one of claims 1 to 8, wherein the aqueous phase contains a filler.

10. Dispersion according to claim 9, containing a colloidal silica or a semi-reinforcing filler based on carbonate.

11. Dispersion according to any one of the preceding claims, containing an adhesion promoter.

12. Dispersion according to claim 11, comprising as adhesion promoter an organosilicic compound, whether or not amine, bearing both:

(1) one or more hydrolysable groups bonded to the silicon atom and

(2) one or more organic groups containing radicals chosen from the group of amino (or diamino), (meth) acrylate, epoxy, alkenyl and / or alkyl radicals.

The dispersion of claim 12, wherein the organosilicon compound is a silane.

The dispersion of claim 13, wherein the silane is:

3-aminopropyltriethoxysilane,

beta-aminoethyl-gamma-aminopropyltrimethoxysilane

beta-aminoethyl-gamma-aminopropylmethyldimethoxysilane

3-aminopropyltrimethoxysilane, vinyltrimethoxysilane,

3-glycidyloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane,

propyltrimethoxysilane,

methyltrimethoxysilane,

- ethyltrimethoxysilane - vinyltriethoxysilane ^'

3-aminopropylmethyldimethoxysilane,

3-aminopropylmethyldiethoxysilane,

methyltriethoxysilane,

propyltriethoxysilane, tetraethoxysilane,

tetrapropoxysilane,

tetraisopropoxysilane, or hydrolysis and condensation products, or mixtures thereof.

15. Dispersion according to any one of the preceding claims, containing a crosslinking silane.

16. Dispersion according to claim 15, wherein the crosslinking silane corresponds to the formula: (R ") _u Si X ( ₄ _ _u) in which the R" groups, which are identical or different, are monovalent organic radicals, in particular methyl or vinyl, u is equal to 1 or 0, the X, which are identical or different, are condensable and / or organic hydrolysable groups chosen from: - OH; alkoxy or alkenyloxy containing from 1 to 10 carbon atoms;

aryloxy containing from 6 to 13 carbon atoms; acyloxy group containing from 1 to 13 carbon atoms;

cetiminoxy group containing from 1 to 8 carbon atoms; amino or amido-functional group containing from 1 to 6 carbon atoms bonded to silicon via an Si-N bond.

17. Dispersion according to claim 16, comprising as crosslinking silane: Si (OC ₂ H ₅ ) ₄ ; CH ₃ Si (OCH ₃ ) ₃ ; CH ₃ Si (OC ₂ H ₅ ) S; (C ₂ H ₅ O) ₃ Si (OCH ₃ );

CH ₂ = CHSi (OCH ₃ ) ₃ ; CH ₃ (CH ₂ = CH) Si (OCH ₃ ) ₂ ; CH ₂ = CH (OC ₂ H ₅ ) ₃ ; CH ₂ = CHSi [ON = C (CH ₃ ) C ₂ H ₅ ]; CH ₃ Si [ON = C (CH ₃ ) ₂ ] ₃

CH ₃ Si [-C (CH ₃ ) = CH ₂ ] ₃ ; methyltri (N-methylacetamidosilane); or methyltris (cyclohexylaminosilane).

18. Dispersion according to any one of the preceding claims, further comprising a second dispersed organic phase containing a silicone oil.

19. Dispersion according to claim 18, wherein the second organic phase is of the crosslinking type by polycondensation.

The dispersion of claim 18 or 19, wherein said second dispersed organic phase comprises a reactive silicone oil having at least two condensable functional groups.

The dispersion of claim 20, wherein the condensable functional groups are selected from:

. OH group;

. alkoxy or alkenyloxy group containing from 1 to 10 carbon atoms; . aryloxy group containing from 6 to 13 carbon atoms;

. acyloxy group containing from 1 to 13 carbon atoms;

. cetiminoxy group containing from 1 to 8 carbon atoms;

. amino- or amido-functional group containing from 1 to 6 carbon atoms, bonded to silicon via an Si-N bond.

22. Dispersion according to claim 20, wherein the second organic phase comprises an α, ω-hydroxylated polydiorganosiloxane (POS) of formula:

- the R, identical or different, each represents a saturated monovalent hydrocarbon radical or unsaturated C ^ CJ _3, substituted or unsubstituted, aliphatic, cyclanic or aromatic; is of sufficient value to give the POS A 'a dynamic viscosity at 25 ° C. ranging from 500 to 1,000,000 mPa.s.

23. Dispersion according to one of claims 18 to 22, wherein the second organic phase comprises a polycondensation catalyst, a filler, a crosslinking agent, a crosslinking silane, a hydroxylated or alkoxylated silicone resin, a plasticizer, a dispersing agent. fillers, or a mixture of at least two of these additives.

24. Dispersion according to one of claims 18 to 24, wherein the silicone phase to polyether phase ratio in the dispersion is between 0.1 and 10.

25. Dispersion according to claim 25, wherein the ratio is between 0.5 and 5.

26. Elastomer obtainable by crosslinking in the presence of a polycondensation catalyst, and by removal of water, a dispersion according to any one of the preceding claims.

27. Kit comprising separately in the same package, on the one hand an aqueous dispersion according to any one of claims 1 to 25, devoid of polycondensation catalyst, and secondly a preparation of a polycondensation catalyst.