CA2364614A1 - Adhesion promoter for a silicone composition - Google Patents

Abstract

An adhesion promoter comprising a pair of compounds selected from the groups of pairs consisting of: (I) an alkenyl, optionally alkoxyl, organosilane, a monomer or polymer devoid of silicon and having an OH group and an epoxy group; (2I) a polymer devoid of silicon, having an OH group and an ethylenic unsaturation, an epoxy organosilicon compound; (3I) a monomer or polymer, devoid of silicon, having an OH group and an ethylenic unsaturation, a monomer or polymer, devoid of silicon, having an OH group and an epoxy group, and optionallly a metal M chelate and/or a metal alkoxide.

Description

ADHESION PROMOTER ESPECIALLY FOR
SILICONE COMPOSITION
The invention relates to new useful adhesion promoters especially in the field of silicones.
It targets the field of silicone compositions developing adhesion properties. The invention applies in particular to compositions crosslinking by hydrosilylation or cold polyaddition (i.e.
temperature ambient, but whose crosslinking can be accelerated, eg by heat) and comprising an adhesion promoter according to the invention The invention relates more particularly to compositions of this type which are in two-component form, and which crosslink by hydrosilylation or polyaddition to produce a thin layer elastomer, usable between other as a covering, for example a protective or mechanical reinforcement of different substrates, for example in textile material (eg fibrous supports, woven, knitted or non-woven), metal (eg aluminum), plastics (eg resins epoxy). It relates in particular to their use for coating woven substrates in the manufacture of air bags for the protection of occupants of vehicles.
The invention also relates to compositions of this type which can be used as an adhesive. The silicone composition is intended to be applied to the interface of two solids. The adhesion mechanism results from crosslinking and hardening of the silicone composition comprising the adhesion promoter.
It can be applied to the different types of materials cited with regard to coating.
In these two applications, one of the essential properties of the silicone elastomer is its adhesive power vis-à-vis its support.
Various Membership agents or promoters have been proposed in the past.
Thus, EP-A-0 681 014 describes a silicone composition, applicable especially as an internal "airbag" coating and consisting of the mixture made of (I) at least one polyorganosiloxane having, per molecule, at least two C2-C6 alkenyl groups linked to silicon,

2 at least one polyorganosiloxane having, per molecule, at least two hydrogen atoms bonded to silicon, (III) a catalytically effective amount of at least one catalyst, composed of at least one metal belonging to the platinum group, (IV) an adhesion promoter, (V) optionally a filler, preferably mineral, (VI) optionally at least one crosslinking inhibitor, (VII) and optionally at least one polyorganosiloxane resin, - in which the adhesion promoter consists exclusively of at least ternary association of the following ingredients:
(IV.1) at least one alkoxylated organosilane containing, per molecule, at least a C2 - C6 alkenyl group, (IV.2) at least one organosilicon compound comprising at least one radical epoxy, (IV.3) at least one metal chelate M and / or a metal alkoxide of general formula: M (OJ) n, with n = valence of M and J = linear alkyl or branched into C1 - C8, M being chosen from the group formed by: Ti, Zr, Ge, Li, Mn, Fe, AI and Mg.
The availability of various adhesion promoting means in the silicone products in general is an important objective for industrialists of sector.
The applicant therefore set itself the objective of proposing new adhesion promoters allowing, among other things, to ensure the adhesion properties of silicone elastomers, eg those intended for the coating of substrates of the type described above or intended for to serve adhesive.
Another objective of the invention is to propose such promoters of adhesion which also make it possible to increase the properties of adhesion, external and / or internal, that is to say between constituents of the elastomer for which concerned internal adhesion.

3 The subject of the present invention is therefore an adhesion promoter comprising a pair of compounds chosen from the group of consisting pairs in - an organosilane, optionally alkoxylated, containing, per molecule at at least one C2-C6 alkenyl group, - a monomer or polymer without silicon atom having in its structure at least one OH and at least one epoxy group;
(2i) - a silicon-free polymer, having in its structure at least one OH group and at least one ethylenic unsaturation, - an organosilicon compound comprising at least one epoxy radical;
(3i) - a monomer or polymer without silicon, having in its structure at at least one OH group and at least one ethylenic unsaturation, - a monomer or polymer without silicon, having in its structure at at least one OH group and at least one epoxy group, and optionally a metal chelate M etlou metal alkoxide of formula 2o general: M (OJ) n, with n = valence of M and J = linear or branched alkyl in C ~ -Cs, M being chosen from the group formed by: Ti, Zr, Ge, Li, Mn, Fe, AI and Mg, The adhesion promoter thus obtained develops good properties grip that can be leveraged both inside of the elastomer obtained after crosslinking (internal adhesion between constituents) and outside (adhesion with a support for example). Favorite apps have been described before.
The polymers are preferably branched polymers and more particularly hyper-branched polymers. These hyper-branched polymers, who include dendrimers, can be described as molecules strongly branched in three dimensions and having a tree structure.
The dendrimers exhibit high degree symmetry, while polymers or simply referred to as hyperbranched macromolecules may have a

4 certain degree of asymmetry within their tree structure. We can say than dendrimers are hyper-branched macromolecules or polymers monodisperse or essentially monodisperse. Macromolecules hyper-branched dendritics or dendrimers are usually formed of a heart or nucleus comprising one or more reaction sites or functions and a certain number of layers of ramifications or generations, possibly one or several spacing layers, and a layer of terminal functions. The longer the the higher the number of layers, the more ramifications and therefore of functions terminal.
Among the hyperbranched polymers, dendrimers and more are preferred.
particularly polyester-based dendrimers.
One can for example use a hyper-branched polyester with functions (ethylenic) alkenyls capable of being obtained from a polymer having at minus one carboxyl group and m hydroxyl groups, m being a larger integer or equal to 3, such as in particular 3, 4, 5, 6, 8; 10, 16 or 32. The prepolymer is the condensation product obtained from at least one monomer chosen from the group consisting of di-, tri- and poly- monocarboxylic acids hydroxyfunctional having from 2 to 18 carbon atoms. The product of condensation obtained constitutes the prepolymer or can be used as product of intermediate condensation as part of a chain extension additional produced by adding at least one monocarboxylic acid monohydroxyfunctional or an internal ether thereof, namely a lactone having from 2 to 24 carbon atoms., The optional addition of an acid monohydroxyfunctional monocarboxylic is carried out by esterification with a molar ratio of intermediate condensation product to monocarboxylic acid monohydroxyfunctional between 1: 1 and at least 1: m. The prepolymer, to know the condensation product with or without chain extension additional, is functionalized (alkenyl functions) by the addition of less a monomer or polymer having at least one allylic unsaturation or acrylic.
3o The addition is carried out at a prepolymer to allyl compound molar ratio or acrylic between 1: 1 and at least 1: m, which leads to a hyper-branched polyester with alkenyl functions having at least one unsaturation allylic or acrylic. For more details, the skilled person can contact report to WO-A-97 23 539.
It is also possible, for example, to use a hyper-branched polyester with epoxy functions capable of being obtained from a prepolymer having at

5 minus one carboxylic group and m hydroxyl groups, m being an integer greater than or equal to 3, such as in particular 3, 4, 5, 6, 8, 10, 16, 32. The prepolymer is a condensation product obtained by a condensation reaction at go at least one monomer chosen from the oroune consisting pn arirlae di-, tri- and poly-hydroxyfunctional monocarboxyls having from 2 to 18 atoms of carbon. The condensation product obtained constitutes the prepolymer or can to be used as an intermediate condensation product for an elongation of additional chain, this extension being carried out by adding at least a monohydroxyfunctional monocarboxylic acid or an internal ether of this acid, i.e. a lactone having 2 to 24 carbon atoms. The bill possible of a monohydroxyfunctional monocarboxylic acid is carried out by esterification at a mole ratio of intermediate condensation product over acid monohydroxyfunctional monocarboxylic between 1: 1 and at least 1: m. The prepolymer, i.e. the condensation product with or without elongation of chain, is functionalized (epoxy functions) by - reaction between at least one hydroxyl group of the prepolymer and at least one monomeric or polymeric compound having at least one epoxy group. Of suitable compounds are, for example, haloalkyl oxyranes, preferably halomethyl oxyranes such as epichlorohydrin. The reaction is carried out at a prepolymer to monomer compound molar ratio or polymer between 1: 1 and at least 1: m.
- or by adding at least one unsaturated compound having at least one oxidizable unsaturation, this unsaturation being epoxidized by the use of a oxidizing agent, the addition being carried out at a prepolymer molar ratio over unsaturated compound between 1: 1 and 1: m.
For more details, the skilled person can refer to WO-A-97 23 538.

6 Those skilled in the art may also refer to the documents WO-A-96 12 754, WO-A-97 45474 and the book “les dendrimères”, Club CRIN
Heterochemistry, Association ECRIN 1998, 32, bd de Vaugirard 75015 PARIS.
Particularly suitable dendritic polymers are those sold.
by the company PERSTORP, for example under the name G2 and Boltorn U1 for dendrimers with allyl and Boltorn E1 functions for dendrimers epoxy.
The monomers are preferably linear or branched monomers.
The monomers with unsaturated functions can be mono or polyalcohols with unsaturated ethylenic groups and containing one or more oxygenated heteroatoms. Particularly suitable for mono or aliphatic polyalcohols with ether functions. Among them may be mentioned those who follow: glycerol monoallyl ether, glycerol diallyl ether, trimethylolethane monoallyl ether, trimethylolethane diallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, pentaerythritol monoallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether and their mixtures.
Also suitable are allyl ethers of monosaccharides or itols (in English “sugar alcohols”), such as glycosides, galactosides, talitol, mannitol, dulcitol, iditol, sorbitol, arabinitol, xylitol and their mixtures. They can also be combined with the aforementioned aliphatic alcohols.
The preferred monomers are - trimethylolpropane monoallylether (CAS 682-11-1).
- triallylpentaerythritol (CAS 1471-17-6) or pentaerythritol triallyl ether.
The epoxidized monomers are preferably epoxy alcohols or glycidols comprising the two required functional groups, namely the epoxy or oxyran configuration and the hydroxyl group. We can cite in particular the following compounds: 2,3-epoxy-1-propanol or glycidol, 2,3-epoxybutanol, 3,4-epoxypentanol, 2,3,4,5-diepoxyhexanol, 2-methyl-3,4-epoxybutanol, 1-2-epoxyhexanol-8, and mixtures thereof. Those skilled in the art may refer to US-A-3,005,832 and US-A-3,041,356 patents for description and preparation such compounds.
Epoxy phenols can also be used. We can thus cite for example polyglycidyl ethers of dihydrophenols such as bisphenol-A or 2,2-bis (4-hydroxyphenol) propane. Advantageously, the skilled person can refer

7 for example in US-A-3,062,840 describing a particular class of epoxy phenols.
These are epoxy-substituted polynuclear polyhydric phenols, comprising an epoxyalkyl chain in which a carbon atom is linked to two hydroxyphenyl substituents. As examples of such bisphenols, we can cite the following compounds: 1,2-epoxy-3,3-bis (hydroxyphenyl) butane, 1,2-epoxy-3,3-bis (hydroxyphenyl) hexane, 1,2-epoxy-4,4-bis (hydroxyphenyl) pentane, 1,2-epoxy-3,3-bis (dihydroxyphenyl) propane, 1,2-epoxy-3,3-bis (o-cresyl) propane, 1,2-epoxy-3,3-bis (dihydroxyphenyl) butane, and mixtures thereof. They can also be combined with epoxy alcohols.
Preferably, when present, the alkoxylated organosilane of the promoter (4) is more particularly selected from the products of formula general next (I) Ra at R ~ R2 C = C Ub Si \ (OR5) -R3 sa in which - R1, R2, R3 are identical hydrogenated or hydrocarbon radicals or different from each other and preferably represent hydrogen, alkyl linear or branched C1-C4 or phenyl optionally substituted with minus C1-C3 alkyl, - U is a linear or branched C ~ - C4 alkylene, or a divalent group of formula -CO-0-alkylene- where the alkylene residue is linear alkyl or branched in C ~ -C4 and the free valence on the right (in bold) is connected to Si - R4 and R5 are identical or different radicals and represent a alkyl in C1 - C4 linear or branched, - a = 0 to 2, preferably 0 or 1 and more preferably still 0 - b = Or 1.
Particular mention may be made of vinyltrimethoxysilane (VTMO) and y-methacryloxypropyltrimetoxysilane (MEMO).

8 As regards the organosilicon epoxy compound, it is preferred, when it is present to choose it - either among the products corresponding to the following general formula (II) ~ R6 O) 3_c X
IF
R ' vs in which ~ R6 is a linear or branched C 1 - C 4 alkyl radical, ~ R ~ is a linear or branched alkyl radical, ~ c is 0, 1, 2 or 3, preferably 0 or 1 and, more preferably still at 0, ~ X is O
E
CR $ CR9R'o ~ O _ D) d with 0 E and D which are identical or different radicals chosen from linear or branched C1-C4 alkyls, 0 d which is equal to 0 or 1, 0 R8, R9, R10 which are the same or different radicals representing hydrogen or a linear or branched alkyl C1-C4, hydrogen being more particularly preferred,

9 0 R8 and R9 or R10 which can alternately constitute together and with the two carbons carrying the epoxy, an alkyl ring having from 5 to 7 links, - either among the products consisting of polydiorganosiloxanes epoxy-functional comprising (i) at least one siloxyl unit of formula (I ~
XpGqSiO
4 - (p + q) in which ~ X is the radical as defined above for formula (II) ~ G is a monovalent hydrocarbon group, free from unfavorable action on the activity of the catalyst and chosen, preferably, from the groups alkyls having from 1 to 8 carbon atoms included, optionally substituted by at least one halogen atom, advantageously, among methyl, ethyl, propyl and 3,3,3-trifluoropropyl groups and also among the aryl groups and, advantageously, among the xylyl radicals and tolyl and phenyl, ~ p = 1 out, ~ q = 0, 1 out, ~ p + q = 1.2or3, and (2i) optionally at least one siloxyl unit of formula (~
Gr Si04-r where G has the same meaning as above and has a value understood between 0 and 3, for example between 1 and 3.
These compounds are preferably epoxyalkoxymonosilanes.
Examples of such compounds that may be mentioned - 3-glycidoxypropyltrimethoxysilane (GLYMO) - or 3,4-epoxycyclohexylethyltrimethoxysilane.
As regards the compound of chelate or aloxide type, it can consist in, or include a metal chelate. The chosen metal M can WO 00/600

10 PCT / FR00 / 00785 thus include one or more ligands such as those derived in particular from a beta-diketone, such as, for example, acetylacetone. This compound may consist still in, or understand, a metal alkoxide having the formula M (OJ) n defined above where the alkoxy radicals are for example the n-propoxy radicals and 5 n-butoxy. Note that, in this formula, one or more alkoxy radicals OJ
may be replaced by one or more ligands constituting a chelate, such as for example an acetylacetonate ligand.
The preferred compounds are those in which the metal M is chosen from the following list: Ti, Zr, Ge, Mn, AI.
It will be noted that titanium is more particularly preferred.
Concrete examples of suitable compounds are those in the structure of which the metal M is chosen from the list: Ti, Zr, Ge, Mn, and AI and is associated - in the case of a chelate: to ligands of acetylacetonate type - in the case of an alkoxide: to n-propoxy or n-butoxy radicals.
Quantitatively, it can be specified that the weight proportions between the various constituents of the adhesion promoter, expressed in percentages by weight of the total of the three are as follows - unsaturated compound> _ 10%
- epoxy compound <_ 90%
- chelate, alkoxide, silicate, polysilicate: from 0 to 25%.
Preferred adhesion promoters of types (i) and (2i) are preferred.
The most preferred adhesion promoters are those of type (2i) comprising an alkenyl-functional dendrimer, an organosilicon compound with epoxy function and a metal chelate and / or alkoxide. The compound organosilicon is preferably GLYMO or 3,4-epoxycyclohexyl-ethyltrimethoxysilane.
Other types of interesting promoters are the following - VTMO or MEMO + epoxy dendrimer + metal chelate or alkoxide - Alkenyl dendrimer + epoxy dendrimer + optionally chelate or alkoxide metallic or ethyl silicate.
The present invention also relates to silicone compositions of the type cold vulcanizable (EVF), including

11 (1) at least one polyorganosiloxane having, per molecule, at least two C2-C6 alkenyl groups linked to silicon, (2) at least one polyorganosiloxane having, per molecule, at least two hydrogen atoms bonded to silicon, (3) a catalytically effective amount of at least one catalyst, based at least one metal belonging to the platinum group, (4) an adhesion promoter according to the invention, (5) possibly a charge, (6) optionally a polyorganosiloxane qualified as an extender and having terminal siloxyl units with hydrogen functions, (7) possibly a neutralizer, (8) optionally a crosslinking inhibitor and / or other) additives) use in the type of composition targeted, (9) optionally a polyorganosiloxane resin.
Those skilled in the art know well that when the constituent (1) has 2 groups alkenyls per molecule, component (2) must have at least 3 atoms of hydrogen per molecule. Conversely, when the constituent (2) has 2 atoms of hydrogen per molecule, component (1) has at least 3 alkenyl groups through molecule.
Advantageously, the adhesion promoter is present at a rate of 0.1 to 10, preferably 0.5 to 5 and more preferably still 1 to 3% by weight through compared to all the constituents of the composition.
Polyorganosiloxane (1) is by weight one of the constituents essential of the composition according to the invention. Advantageously, it is a product with (i) siloxy units of formula TaZbSiO 4 _ (a + b) (1.1) in which - T is an alkenyl group, preferably vinyl or allyl, - Z is a monovalent hydrocarbon group, free of unfavorable action on the activity of the catalyst and chosen, preferably, from alkyl groups having from 1 to 8 carbon atoms included, optionally substituted with

12 at least one halogen atom, advantageously, among the methyl groups, ethyl, propyl and 3,3,3-trifluoropropyl and as well as among the groups aryles and, advantageously, among the xylyl, tolyl and phenyl radicals, - a is 1 or 2, b is 0, 1 or 2 and a + b is between 1 and 3, from preference between 2 and 3, and (2i) optionally other siloxyl units of formula Z ~ SiO 4 _ c 2 (1.2) where Z has the same meaning as above and it has a value understood between 0 and 3, preferably between 2 and 3.
It is advantageous that this polydiorganosiloxane has a viscosity comprised between 100 and 200,000 mPa.s. It is preferably from 500 to 5000 mPa.s in the case where a reinforcing filler is used, in particular a reinforcing filler treated in situ. In the absence of such a charge, it preferably becomes between 10,000 and 200,000 mPa.s.
Of course, in the case of a mixture of several oils (1) of viscosity different, the viscosity of the mixture is taken into account.
All the viscosities in question here correspond to a quantity dynamic viscosity which is measured, in a manner known per se, at 25 ° C.
The polyorganosiloxane (1) can only be formed of units of formula (1.1) or may contain, in addition, reasons for formula (1.2).
Z is generally chosen from methyl, ethyl and phenyl radicals, At least 60 mol% (or by number) of the radicals Z being radicals methyl.
Examples of siloxyl units of formula (1.1) are the unit vinyldimethylsiloxyle, vinylphenylmethylsiloxyle motif, motif vinylmethylsiloxyle and the vinylsiloxyl motif.
Examples of siloxyl units of formula (1.2) are the SiOq. ~ 2 units, dimethylsiloxyl, methylphenylsiloxyl, diphenylsiloxyl, methylsiloxyl and phenylsiloxyl.

13 Examples of polyorganosiloxanes (1) are linear compounds and cyclic such as: dimethylpolysiloxanes with dimethylvinylsilyl ends, the (methylvinyl) (dimethyl) polysiloxane copolymers with ends trimethylsilyles, (methylvinyl) (dimethyl) polysiloxane copolymers with ends dimethylvinylsilyles; cyclic methylvinylpolysiloxanes.
The polyorganosiloxane (2) is preferably of the type of those comprising (i) siloxy units of formula (2.1):
Hd L e Si0 4- (d + e) in which - L is a monovalent hydrocarbon group, free of unfavorable action on the activity of the catalyst and chosen, preferably, from alkyl groups having from 1 to 8 carbon atoms included, optionally substituted with at least one halogen atom, advantageously, among the methyl groups, ethyl, propyl and 3,3,3-trifluoropropyl and as well as among the groups aryles and, advantageously, among the xylyl, tolyl and phenyl radicals, - d is 1 or 2, e is 0, 1 or 2, d + has a value between 1 and 3, of preferably between 2 and 3, and (2i) optionally other siloxyl units of average formula (2.2) Lg Si0 where L has the same meaning as above and g has a value understood between 0 and 3, preferably between 2 and 3.
The dynamic viscosity of this polyorganosiloxane (2) is at least equal to 10 mPa.s and, preferably, it is between 20 and 1000 mPa.s.
The polyorganosiloxane (2) can only be formed of units of formula (2.1) or include in addition patterns of formula (2.2).

14 The polyorganosiloxane (2) may have a branched linear structure cyclic or networked.
Group L has the same meaning as group Z above.
Examples of patterns of formula (2.1) are H (CH3) 2Si01 / 2, HCH3Si02 / 2, H (CgHS) Si02 / 2 The examples of patterns of formula (2.2) are the same as those given above for the reasons of formula (1.2).
Examples of polyorganosiloxane (2) are linear compounds and cyclical like - dimethylpolysiloxanes with hydrogenodimethylsilyl ends, - copolymers with (dimethyl) (hydrogenomethyl) polysiloxane units containing trimethylsilyl ends, - copolymers with (dimethyl) (hydrogenomethyl) polysiloxane units containing hydrogenodimethylsilyl ends, - hydrogenomethylpolysiloxanes with trimethylsilyl ends, - cyclic hydrogenomethylpolysiloxanes.
The ratio of the number of hydrogen atoms bonded to silicon in the polyorganosiloxane (2) out of the total number of alkenyl unsaturated groups of polyorganosiloxane (1) is between 1 and 5, preferably between 1 and 2.
2o The catalysts (3) are also well known. Preferably, platinum and rhodium compounds. We can, in particular, use the complexes of platinum and an organic product described in patents US-A-3 159 601, US-A-3 159 602, US-A-3 220 972 and European patents EP-A-0 057 459, EP-A-0 188 978 and EP-A-0 190 190, platinum complexes and vinylated organosiloxanes described in patents US-A-3,419,593, US-A-3 715 334, US-A-3 377 432 and US-A-3 814 730. The catalyst generally preferred is based on platinum. In this case, the weight quantity of catalyst (3), calculated by weight of platinum-metal, is generally between 2 and 400 ppm, preferably between 5 and 50 ppm based on the total weight of polyorganosiloxanes (1) and (2).
Advantageously, the silicone composition according to the invention can also include at least one additive retarder or inhibitor of crosslinking (8), chosen from the following compounds - polyorganosiloxanes substituted with at least one alkenyl which can be optionally present in cyclic form, tetramethylvinyltetrasiloxane being particularly preferred, - pyridine 5 - phosphines and organic phosphites, - unsaturated amides - alkylated maleates - and acetylenic alcohols.
These acetylenic alcohols, (Cf. FR-B-1 528 464 and FR-A-2 372 874), which 10 are part of the hydrosilylation reaction blockers favorite, have for formula R '- (R ") C (OH) -C-_CH
formula in which, - R 'is a linear or branched alkyl radical, or a phenyl radical;

15 - R "is H or a linear or branched alkyl radical, or a phenyl radical ; the radicals R ', R "and (carbon atom located at the triple bond which can possibly form a cycle;
the total number of carbon atoms contained in R 'and R "being at least 5, of preferably from 9 to 20.
Said alcohols are preferably chosen from those having a dot boiling above 250 ° C. There may be mentioned as examples - fethynyl-1-cyclohexanol-1;
- 3-methyl-dodecy-10 -10;
- trimethyl-3,7,11 dodécyne-1 0l-3;
- diphenyl-1,1 propyne-2 0l-1;
- 3-ethyl-6-ethyl nonyne-1 0l-3;
- 2-methyl-butyne-30l-2;
- 3-methyl-pentadécyne-1 0l-3.
These α-acetylenic alcohols are commercial products.
Such a retarder is present at a maximum of 5,000 ppm, preferably at a rate of 100 to 2000 ppm relative to the total weight of organopolysiloxanes (1) and (2).

16 The filler (5) can be a reinforcing or non-reinforcing filler, or a combination of the two, depending on the properties sought.
The reinforcing filler is preferably a siliceous filler.
The reinforcing siliceous fillers are chosen from silicas colloidal, combustion and precipitation silica powders or their mixtures.
These powders have an average particle size generally close to or less than 0.1 Nm and a BET specific surface greater than 50 m2 / g, preferably between 50 and 400 m2 / g, in particular between 150 and 350 m2 / g.
Among the non-reinforcing additional fillers, there may be mentioned especially diatomaceous earth, calcium carbonate, ground quartz and zirconium oxide or ground zirconia. These fillers have a particle size generally between 0.001 and 300 ~, m and a BET surface less than 100 m 2 / g.
Other additional charges are for example carbon black, titanium dioxide, aluminum oxide, hydrated alumina, vermiculite expanded, unexpanded vermiculite, zinc oxide, mica, talc, oxide of iron, barium sulfate and slaked lime.
Other additional charges may be charges microspheres.
The reinforcing silicas can preferably be incorporated such which or after being treated with organosilicon compounds usually used for this purpose. Among these compounds are methylpolysiloxanes such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, methylpolysilazanes such as hexamethyldisilazane, hexamethylcyclotrisilazane, chlorosilanes such that the dimethyldichlorosilane, trimethylchlorosilane, methylvinyldichlorosilane, the dimethylvinylchlorosilane, alkoxysilanes such as dimethyldimethoxysilane, dimethylvinylethoxysilane, trimethylmethoxysilane. During this treatment, the silanes can increase their starting weight by up to 20%, from preferably about 10%.
Preferably the siliceous filler is treated in situ.

17 By in situ treatment of the siliceous filler is preferably meant the bringing together the load and the compatibilization agent in the presence at least one portion of polyorganosiloxane silicone oil (1). So particularly preferred, the procedure is as described in WO-A-98 58997 which those skilled in the art can refer to this for more details. So particularly preferred, this essentially consists of introducing the agent of compatibilization (CA) in two stages in the preparation medium on the one hand, before and / or substantially simultaneously with contact at least part of the silicone oil used with at least one portion of the siliceous filler used, this introduction of AC (portion 1) operating in one or several times and corresponding to a proportion less than or equal to 8%, of preferably at 5% and, more preferably still, at 3% by dry weight per compared to the total load;
~ and on the other hand (portion 2), after this placing in the presence of oil silicone / filler.
The compatibilization agent for portion 1 is thus chosen from molecules that meet at least two criteria present a strong interaction with silica at the level of its bonds hydrogen with itself, and with the surrounding silicone oil - be itself, or its degradation products, easily removed from the final mixing by heating under vacuum or under gas flow, and the low molecular weight compounds are therefore preferred, By globally equivalent quantity is meant compliance with the order of magnitude of the molar quantities of AC with respect to hydrogen bonds.
The agent of portion 1 could for example be - a silazane, preferably a disilazane, or mixtures thereof, hexamethyldisilazane (HMDZ) being the preferred silazane and being able to be associated with divinyltetramethyldisilazane - a di- or preferably mono-functional hydroxylated siloxane - an amine such as ammonia or a low-weight alkylamine molecular like diethylamine - a low molecular weight organic acid such as formic acids or acetic,

18 - And is preferably used in the presence of water.
The compatibilizers of portion 2 can be chosen from the different silazanes and disilazanes encountered above, taken alone or in combination mixtures with one another, preferably from disilazanes, hexamethyldisilazane associated or not with divinyltetramethyldisilazane being particularly preferred.
The silicic reinforcing filler represents from 10 to 50% by weight of the suspension obtained. In practice, this charge is of the order of 25 ~ 10%.
Advantageously, the proportion of compatibilization agent introduced initially is at most equal to 8% of the reinforcing filler (and by example between 1 and 3% of the reinforcing filler, preferably between and 2%). In addition, it can be indicated that the total quantity of agent AC is, of preferably between 5 and 30% of the silicic filler, preferably Between 10 and 20%.
Alternatively, one can use art compatibilization methods prior providing for early treatment with silazane (eg FR-A-2 320 324) or late treatment (eg EP-A-462 032) knowing, however, that according to the silicas used their use will generally not allow obtaining the best results in terms of mechanical properties, in particular extensibility, obtained by a two-stage treatment in accordance with the invention.
In the case where the in situ treatment leads to a basic pH, one can add a neutralizer (7) such as for example weak acids (eg acid acetic and buffered phosphoric acid). Note that this neutralization may to be advantageously obtained by incorporating acidic fillers such than ground quartz.
The microspheric fillers are preferably microspheres expandable organics comprising, as is known per se, a wall polymer containing liquid or gas. We cause the expansion of these microspheres by heating them beyond the softening point of the polymer and at a temperature sufficient to vaporize the liquid or expand properly gas, which may for example be an alkane such as isobutane or isopentane.
The wall may consist, as is known per se, of polymers or copolymers, for example prepared from vinyl chloride monomers, vinylidene chloride, acrylonitrile, methyl methacrylate or styrene or

19 mixtures of polymers and / or copolymers, for example in particular of acrylonitrile / methacrylonitrile copolymer, acrylonitrile / chloride copolymer of vinylidene. See in particular US-A-3,615,972.
They can be incorporated into the composition either in the expanded state or before their expansion, which can be induced, by appropriate heating, during crosslinking the composition.
It may be advantageous for the microspheres to be treated on a surface as is known per se; to promote its dispersion in the composition; they may in particular be expandable microspheres or expanded having an inorganic coating, for example silica or salts or metal hydroxides such as Ca, Mg, Ba, Fe, Zn, Ni, Mn, as is describes for example in EP-A-486 080, or even carbonates, for example carbonate calcium.
As a preferred example, the microspheres sold under the designation Dualite ~ by UCB-chemicals.
Before their expansion, the microspheres will preferably have a diameter between 3 and 50 Nm, more particularly between 5 and 30 Nm.
We will also look for a diameter after expansion (in situ or original) between 10 and 150, in particular between 20 and 100 pm.
These microspheres will be present in particular at a rate of 1 to 30% by weight, preferably from 2 to 10% and more preferably from more than 3 or 4 %, by weight relative to the total composition.
The polyaddition composition, can also comprise a polyorganosiloxane extender (6) having, per molecule, two groups siloxyls carrying a hydrogen atom linked to silicon. These polyorganosiloxane extenders are perfectly known to those skilled in the art.
The polyorganosiloxane extender (6) has siloxyl units terminals HR ° 2Si0 ~ r ~
with . Identical or different between them and corresponding to a group linear or branched C ~ -Cs alkyl and / or substituted or unsubstituted aryl, R °
being preferably CH3.
Note that the rest of the molecule is a polydiorganosiloxane, of Preferably a polydimethylsiloxane.
By way of example, mention may be made of poly (dimethylsiloxy) -a, w-(dimethylhydrogenosiloxy).
According to a particular form of the invention, the silicone composition combines a reinforcing filler (5) treated in situ, preferably according to WO-A-98 58997, and an extender polyorganosiloxane (6). In such composition, if the alkoxylated organosilane is present, b is preferably 1. This type of composition is particularly useful for coating substrates, in particular of fibrous substrates, for example for the production of "airbags".
The composition according to the invention can also comprise at least one 15 polyorganosiloxane resin (9) comprising at least one alkenyl residue in its structure, and this resin has a weight content in groups) alkenyl (s) between 0.1 and 20% by weight and preferably between 0.2 and 10% by weight.
These resins are organopolysiloxane oligomers or polymers well-known and commercially available branched branches. They come under

20 in the form of solutions, preferably siloxane. They present, in their structure, at least two different motifs chosen from those of formula R3Si0 °, 5 (motil M) 1, R2Si0 (motif D) 1, RSi0 ~, 5 (motif T) and Si02 (motif Q), one at less of these patterns being a T or Q pattern, The radials R are identical or different and are chosen from among the linear or branched C1-C6 alkyl radicals, C2- alkenyl radicals C4, phenyl, trifluoro-3,3,3 propyl. We can cite for example: as radicals R
alkyls, methyl, ethyl, isopropyl, tert-butyl and n-hexyl radicals, and as alkenyl radicals R, vinyl radicals.
It should be understood that in the resins (9) of the aforementioned type, part radicals R are alkenyl radicals.
As examples of organopolysiloxane oligomers or polymers branched, there may be mentioned MQ resins, MDQ resins, TD resins and MDT resins, the alkenyl functions can be carried by the M, D units

21 and / or T. As an example of resins which are particularly suitable, we Mention may be made of vinylized MDQ resins having a group weight content vinyl between 0.2 and 10% by weight.
This compound (9) has in particular the function of increasing the resistance mechanics of the elastomer, eg of the silicone elastomer coating, as well as his adhesion, eg in the coating of the faces of a synthetic fabric (through polyamide), for example in the manufacture of "airbags".
When present, this structural resin is advantageously present in a concentration of between 10 and 70% by weight relative to all the constituents of the composition, preferably between 30 and 60%
in by weight and, more preferably still, between 40 and 60% by weight.
In a particularly preferred manner, the polyorganosiloxane resin (9) will comprise at least 2% by weight of SiO 2 units (Q units), in particular from 4 to 14%, preferably from 5% to 12%.
The incorporation of these resins allows, if desired, to dispense with filler and in particular of reinforcing siliceous filler. The interest is then ability to apply very thin layers of elastomer, for example with deposited weight less than or equal to 30 g / m2.
According to another of its aspects, the present invention relates to a two-component precursor system of this preferred silicone composition described supra. Such a precursor system is presented in two parts A and B
separate, intended to be mixed to form the composition, one of these parts A
or B comprising the catalyst (3) and urge only species (1) or (2) of polyorganosiloxane. Another characteristic of this precursor system is that its part A or B containing the polyorganosiloxane (2) is free of compounds of chelate or metal alkoxide type of the promoter (4) and that its part A or B
including the unsaturated promoter compound (4) does not include the catalyst (3); when present, the charge (5) treated in situ is present in where parts A and B which contain the polyorganosiloxane (1).
The determination and optimization of the two parts A and B to avoid bring together in one of the parts species likely to react together, are part of the normal abilities of those skilled in the art.

22 Once mixed together, parts A and B form a ready-to-use silicone composition which can be applied to the support through any suitable coating means (for example doctor blade, cylinder, screen printing, etc.).
Although crosslinking can be done cold (i.e. at a temperature near room temperature near 20 ° C), the compounds according to the invention are crosslinked by appropriate means, in particular by thermal and / or by electromagnetic radiation (electron radiation accelerated or "electron beam"), and / or infrared.
Another subject of the invention is the use of the adhesion promoter according to the invention in the preparation of silicone compositions, in particular those usable for coating various substrates such as those described above and or for adhesive use.
According to a first preferred embodiment of the invention, the compositions silicone comprising the above promoter can be used in particular for coating or coating, woven fibrous supports, knitted or not woven, and preferably woven, knitted or non-woven fiber supports classic or technical synthetics, advantageously polyester or polyamide and glass fabrics.
The invention relates more particularly to the coating or coating of at least one of the faces (interior and / or exterior) of the flexible support material (polyamide fabric for example) useful for making bags by sewing inflatable for the personal protection of vehicle occupants, in the event of of shock.
According to a second preferred method, the compositions according to the invention can also be used as an adhesive, in particular for textile pieces, of metal or plastic.
The present invention also relates to the use of these compositions or of their precursor systems as described above, for coating or coating of fibrous supports as described above or for adhesion.
Finally, adhesion promoters can also be used in heat-crosslinkable silicone compositions known under the name EVC and in particularly those which crosslink by polyaddition or EVCs with peroxide.

23 The invention also relates to the use of the monomers and polymers described more high for the realization of adhesion promoters and for the preparation of silicone compositions.
The invention will now be described in more detail using methods of realization then by way of nonlimiting examples.
EXAMPLES
The polymer tested is a dendritic polymer of the ester type. It is characterized by ~ a basic star heart with 4 branches ~ level 2 generation ~ an allylic functionality ~ allyl functionality rate: 2.06 mmol / g 14.4 mole allyle / mole G2 ~ residual hydroxyl functionality ~ rate of residual OH functionality: 0.11 mmol / g 0.8 mole hydroxy / mole G2 This dendritic polymer hereinafter called G2 is available from the PERSTORP company.
EXAMPLE 1: REFERENCE COMPOSITION 1 It is a two-component silicone composition the composition of which is particularly suitable for bonding.
First, a suspension called premix is prepared by mixing in a reactor at room temperature - 51.7 parts of resin of structure MM ~ 'DD ~' Q containing 0.9% by weight of vinyl groups (Vi) and consisting of: 21% by weight of units (CH3) 3Si0o, s; 0.2% by weight of units (CH3) 2ViSi0o, 5; 67.8% by weight of (CH3) 2Si0 units; 3% by weight of (CH3) ViSiO units; 8% by weight of Si02 patterns.

24 - 15 parts by weight of a polydimethylsiloxane (PDMS) blocked by (CH3) 2ViSi0o, 5 units with a viscosity of 10,000 mPa.s and containing 0.005 SiVi functions per 100 g of oil - 33.3 parts by weight of a crushed silica of average particle size about 2Nm.
This premix is used for the preparation of parts A and B of the two-component Part A of bicomponent n ° 1 In a reactor at room temperature is mixed - 99.3 parts by weight of premix - 0.7 part by weight of butyl orthotitanate - 0.004 part by weight of platinum metal in the form of a complex metallic known as Karstedt catalyst Part B of bicomaose n ° 1 In a reactor at room temperature, mixing - 90.3 parts by weight of premix - 4.52 parts by weight of a poly (dimethyl) (hydrogen methyl) siloxane blocked by (CH3) ZHSiOo patterns, s having a viscosity of 25 mPa.s and containing a total of 0.7 SiH function per 100 g of oil - 0.04 part by weight of EthynyICycIoHexanol - 1.8 parts by weight of vinyltrimethoxy silane (VTMO) - 1.8 parts by weight of 3-glycidoxypropyltrimethoxysilane (GLYMO) - 0.2 part by weight of a coloring base.
The bicomponent is obtained by mixing at room temperature 100 parts of A # 1 and 100 parts of B # 1.
Composition C1 is thus obtained.
EXAMPLE 2: REFERENCE COMPOSITION 2 This is the previous two-component silicone composition to which we have removed the unsaturated silane from the adhesion promoter.

We use the same suspension called premix and the same part A
as described in example 1.
Part A of bicomponent n ° 2 5 This is part A of bicomponent n ° 1 Part B of two-component n ° 2 In a reactor at room temperature is mixed - 90.3 parts by weight of premix 10 - 4.52 parts by weight of a poly (dimethyl) (hydrogen methyl) siloxane blocked by (CH3) 2HSi0o patterns, s having a viscosity of 25 mPa.s and containing a total of 0.7 SiH function per 100 g of oil.
- 0.04 part by weight of EthyInyICycIoHexanol - 1.8 parts by weight of 3-glycidoxypropyltrimethoxsilane (GLYMO) 15 - 0.2 parts by weight of a coloring base The bicomponent is obtained by mixing at room temperature 100 parts of A n ° 2 and 100 parts of B n ° 2. We thus obtain composition C2.
EXAMPLE 3: COMPOSITION ACCORDING TO THE INVENTION
The composition is that of the two-component silicone preparation of reference to which the dendritic polymer has been added.
We use the same suspension called premix and the same part A

25 as described in Example 1.
Part A of bicomponent n ° 3 This is part A of bicomponent n ° 1 Part B of two-component n ° 3 In a reactor at room temperature is mixed - 90.3 parts by weight of premix

26 4.52 parts by weight of a poly (dimethyl) (hydrogen methyl) siloxane blocked by patterns (CHs) 2HSi0o, s having a viscosity of 25 mPa.s and containing a total of 0.7 SiH function per 100g of oil - 0.04 part by weight of EthynyICycIoHexanol - 3.6 parts by weight of the dentritic polymer with allylic functions (G2) - 1.8 parts by weight of 3-glycidoxypropyltrimethoxysilane (GLYMO) - 0.2 part by weight of a coloring base.
The bicomponent is obtained by mixing at room temperature 100 parts of A n ° 3 and 100 parts of B n ° 3. We thus obtain the composition C3.

Adhesive disturbances are assessed by a peel test.
For this, a layer of controlled thickness of the two-component is deposited.
between two substrates and the two-component crosslinking is carried out.
After cooling, the force necessary to cause the peeling of substrates by means of a traction machine provided with a device for recording the force exerted.
The substrate S used for these assessments is a polyamide 66 fabric of 470 dtex, woven in 18x18 strands.
The following results were recorded: Table 1 Bicomponent Substrate 1 Substrate 2 Weight Strength of coat Nlmm 9lmz C 1 SS 120 0.82 C2 SS 110 0.36 C3 SS 115 0.7 ~

27 Products tested The tested products are described below Boltorn U 1 is a dendrimer of mass approximately 8000 which carries approximately 14 allyl functions.
Boltorn E1 is a dendrimer of mass approximately 10500 which carries approximately 11 epoxy functions.
Polyol PS50 is an ethoxylated pentaerythritol of mass around 350 which carries 4 hydroxy functions but no unsaturated function (for comparison.
These products are available from PERSTORP
The composition is that of the standard two-component silicone preparation of Example 1 in which one of the promoter silanes has been replaced by Mon tested products (dendritic polymers). Type promoter additives 1 (to unsaturated function) replace the VTMO; type 2 promoter additives (to epoxy function) replace the GLYMO.
We use the same suspension called premix and the same part A
as described in example 1.
Part A of two components n ° 4 to 7 This is part A of bicomponent n ° 1 Part B of bicomponents n ° 4 to 7 In a reactor at room temperature is mixed - 90.3 parts by weight of premix, - 4.52 parts by weight of a poly (dimethyl) (hydrogen methyl) siloxane blocked by patterns (CHs) 2HSi0o, 5 having a viscosity of 25 mPa.s and containing a total of 0.7 SiH function per 1008 of oil - 0.04 part by weight of EthynyICycIoHexanol - 1.8 parts by weight of VTMO or one of the type 1 promoter additives (see table 2) - 1.8 parts by weight of GLYMO or one of the promoter additives of the type 2 (see table 2) - 0.2 part by weight of a coloring base.

28 The bicomponent is obtained by mixing at room temperature 100 parts of A n ° 4 to 7 and 100 parts of B n ° 4 to 7. We so gets them compositions C4 to C9.
PERFORMANCES
The adhesive performances are evaluated as previously by the peel test.
your applied surface weights are always around 120 g / m2.
The following results have been recorded Table 2 Bicomponent Additive 1 Additive 2 Peel strength Nlmm C 1 VTMO GLYMO 0.82 C4 U 1 GLYMO 0.52 C5 ~ ITMO E1 0.15 COMMENTS ON EXAMPLES
The results presented demonstrate the equivalence of the disturbances according to compositions C1 and C3 and the advantage over composition C2 which does not contains no unsaturated promoter.
Example 4 demonstrates the capacity of the dendrimers multi-functional in terms of self-adhesion to the compositions which contain. We also observe the need for a double function of these molecules for this use.
We also know that the adhesive power of these compositions is not limited to the area of bonding textiles. This is how they allow also bonding to metal, especially aluminum and plastics, especially epoxy resins.
It has also been noted, without being limiting, that the G2 dendrimer introduced into a heat-crosslinkable silicone rubber under the action of a peroxide sticks to the mold in which it is shaped. This further demonstrates the potential of these products to give a self-adhesive character to silicone elastomer compositions.

Claims (18)

1.- Adhesion promoter comprising a couple of selected compounds in the group of couples consisting of:
- an organosilane, optionally alkoxylated, containing, per molecule at least one C2-C6 alkenyl group, - a monomer or polymer without silicon atoms having in its structure at least one OH and at least one epoxy group;
(2i) - a polymer without silicon, having in its structure at least one OH group and at least one ethylenic unsaturation, - an organosilicon compound comprising at least one epoxy radical;
(3i) - a monomer or polymer without silicon, having in its structure at at least one OH group and at least one ethylenic unsaturation, - a monomer or polymer without silicon, having in its structure at at least one OH group and at least one epoxy group, and optionally a chelate of metal M and/or metal alkoxide of formula general: M(OJ)n, with n = valence of M and J = linear or branched alkyl in C8, M being chosen from the group consisting of: Ti, Zr, Ge, Li, Mn, Fe, Al and Mg, 2. Adhesion promoter according to claim 1, characterized in that the polymers are selected from the group consisting of branched polymers and hyper-branched polymers. 3. Adhesion promoter according to claim 2, characterized in that the hyperamified polymers are dendrimers. 4.- adhesion promoter according to claim 3, characterized in that dendrimers are based on polyesters. 5.- adhesion promoter according to claim 1, characterized in that the monomers are linear or branched monomers. 6.- adhesion promoter according to claim 5, characterized in that the monomers are selected from the group consisting of mono and polyhydric alcohols unsaturated ethylenic groups containing one or more heteroatoms oxygenates, allyl ethers of monosaccharides or itols and mixtures thereof. 7.- adhesion promoter according to claim 6, characterized in that the alcohols are aliphatic mono or polyalcohols with ether functions. 8. Adhesion promoter according to claim 5, characterized in that the monomers are selected from the group consisting of: glycerol monoallyl ether, glycerol diallyl ether, trimethylolethane monoallyl ether, trimethylolethane diallyl ether, trimethylopropane monoally ether, trimethylolpropane diallyl ether, pentaerythritol monoallyl ether pentaerythritol diallyl ether, pentaerythritol trially ether, glycosides, galactosides, talitol, mannitol, dulcitol, iditol, sobitol, arabinitol, xylitol and mixtures thereof. 9.- adhesion promoter according to claim 5, characterized in that the monomers are selected from the group consisting of: trimethylopropane monoallyl ether, triallylpentaerythritol. 10.- adhesion promoter according to claim 5, characterized in that the monomers are selected from the group consisting of epoxy and epoxy alcohols phenols. 11. Adhesion promoter according to claim 10, characterized in that that they are chosen from the group consisting of: 2,3-epoxy-1-propanol or glycidol, 2,3-epoxybutanol, 3,4-epoxypentanol, 2,3,4,5-diepoxyhexanol, 2-methyl-3,4-epoxybutanol, 1-2-epoxyhexanol-8, 3,4-epoxyhexanol (?), 2,3-epoxypentanol (?) , 2,2-bis(4-hydroxyphenol)propane, 1,2-epoxy-3,3-bis(hydroxyphenyl)butane, 1,2-epoxy-3,3-bis(hydroxy-phenyl)hexane, 1,2-epoxy-4,4-bis(hydroxyphenyl)-pentane, 1,2-epoxy-3,3-bis(dihydroxyphenyl)propane, 1,2-epoxy-3,3-bis(o-cresyl)-propane, 1,2-epoxy-3,3-bis(dihydroxyphenyl)butane, and mixtures thereof. 12. Adhesion promoter according to claim 1, characterized in that it comprises the pair (3i) and an alkyl silicate or polysilicate. 13.-Cold vulcanizable silicone composition, including:
(1) at least one polyorganosiloxane having, per molecule, at least two alkenyl groups, C2-C6 bonded to silicon, (2) at least one polyorganosiloxane having, per molecule, at least two hydrogen atoms bonded to silicon, (3) a catalytically effective amount of at least one catalyst, based on at least one metal belonging to the platinum group, (4) an adhesion promoter characterized in that it comprises an adhesion promoter according to one any of claims 1 to 12. 14.-Composition according to claim 13, characterized in that it further comprises a compound selected from the group consisting of:
(5) a load, (6) a polyorganosiloxane qualified as an extender and having patterns terminal siloxyls with hydrogen functions, (7) a neutralizer, (8) a crosslinking inhibitor, (9) expanded inorganic hollow microspherical fillers or expandable, (10) a polyorganosiloxane resin, and mixtures thereof. 15.-Use of an adhesion promoter according to any one of claims 1 to 12, for the preparation of silicone compositions having adhesion properties. 16.-Use of an adhesion promoter according to claim 15, for the preparation of a crosslinking silicone composition at room temperature by hydrosilylation or polyaddition. 17.-Use of an adhesion promoter according to claim 15 or 16, for the preparation of silicone compositions intended for the coating of substrates. 18.-Use of an adhesion promoter according to claim 15 or 16, for the preparation of silicone compositions intended to serve as an adhesive.