EP1844104A1

EP1844104A1 - Single-constituent polyorganosiloxane composition crosslinkable by condensation and comprising a filler

Info

Publication number: EP1844104A1
Application number: EP05850588A
Authority: EP
Inventors: Pascale Monti; Marc Chaussade; Christine Prebet
Original assignee: Rhodia Chimie SAS
Current assignee: Elkem Silicones France SAS
Priority date: 2004-12-23
Filing date: 2005-12-22
Publication date: 2007-10-17
Also published as: JP2008525560A; KR20070090951A; FR2880030B1; WO2006070118A1; FR2880030A1; CN101160357A; US20090082506A1

Abstract

The invention concerns a single-constituent polycondensation polyorganosiloxane composition comprising a filler. The invention concerns single-constituent polyorganosiloxane (POS) compositions storage-stable in the absence of humidity and crosslinkable, in the presence of water, into elastomer, compositions comprising at least one crosslinkable linear polyorganopolysiloxane POS, a filler and a crosslinking catalyst, the POS having alkoxy, oxime, acyl and/or enoxy, preferably alkoxy, ends, and the composition being essentially free of hydroxylated POS at the ends and the catalyst comprising a vanadium compound and a titanium compound.

Description

A one-component polyorganosiloxane polycondensation composition comprising a filler

The field of the invention is that of single-component silicone compositions, comprising a filler, stable to storage in the absence of moisture, and crosslinking by elastomeric polycondensation, at room temperature (for example 5 to 35 ° C.) and in the presence of water (eg ambient humidity). These compositions are sometimes called EVF-1 for one-component cold vulcanizable elastomer.

The formulations of the cold-vulcanizable elastomers by polycondensation generally involve a silicone oil, generally polydimethylsiloxane (PDMS), with hydroxyl endings, optionally pre-functionalized with a silane so as to have Si (OR) ₃ ends, a crosslinking agent R _b Si (OR ') _4-b> where b <3, a polycondensation catalyst, typically a tin salt or an alkyl titanate, a reinforcing filler and any other additives such as fillers, adhesion promoters , dyes, biocides, etc. During the crosslinking, the atmospheric humidity allows the polycondensation reaction, which leads to the formation of the elastomeric network.

These elastomers can be used in a wide range of applications, such as gluing, sealing and molding. The largest markets are single-component products (EVF-1) in the form of sealants, adhesives or coatings that crosslink with the aid of air humidity.

Such EVF-1 are used in particular in the building, automotive, household appliances as a means of sealing, grouting and / or assembly among others. The rheological properties of these monocomponent silicone materials (pasty form) are the subject of much attention in these applications. It is the same with regard to their resistance to weather and heat, their flexibility at low temperature, their ease of implementation and their rapid crosslinking / hardening in situ, in contact with the humidity of the air.

When it is set, the material first forms a superficial skin (taken at the surface whose rate is measured by the TFP skin formation time), then the crosslinking must be continued until complete hardening (taken to heart ). Kinetics of setting is an essential criterion of EVF-1. It is therefore of great interest to be able to have compositions which are crosslinkable at heart and which have a setting kinetics as fast as possible. The crosslinking catalysts conventionally used are either titanium compounds or vanadium compounds. Titanium compounds are known to lead to compositions having slow surface uptake. Surface uptake is known to be faster with vanadium compounds. However, taking it to heart is not always optimal. In particular, the present inventors have found that the presence of a carbonate filler interferes with the crosslinking of a vanadium compound catalyzed EVF-1 composition. This interference is reflected in particular by taking a slow heart.

In addition, the EVF-1s whose alkoxy reactive groups have a much slower cross-linking kinetics than EVF-1s having acetic or oxime groups as reactive groups.

The authors therefore set themselves the objective of proposing a solution to these problems, in order to propose single-component silicone compositions comprising a filler, including a filler based on carbonate, which is capable of crosslinking under good elastomer conditions, by polycondensation. and at room temperature under the effect of moisture.

Another object of the invention is to accelerate the kinetics of crosslinking of EVF-1 reactive groups of alkoxy type.

Among other things, the compositions according to the invention must be capable of crosslinking according to a setting kinetics combining rapid surface uptake and good grip at heart. In particular, a skin formation time of less than 15 minutes, preferably less than or equal to 10 minutes, is aimed at.

Another object of the invention is to provide such a composition that does not release toxic volatile product during crosslinking.

These and other objectives are achieved by the combined use of a vanadium compound and a titanium compound as a catalyst or accelerator of the crosslinking reaction of a storage stable polyorganosiloxane (POS) composition. in the absence of moisture, comprising a filler, and crosslinking, in the presence of water, of elastomer, composition in which the POS are crosslinkable non-hydroxylated linear POSs and having functionalized ends of alkoxy, oxime, acyl and / or or enoxy, preferably alkoxy. The invention does not exclude the presence of a minority proportion of POSs comprising OH groups, ie being able to represent less than 10 .mu.mol OH per g of composition. Indeed, these POS may be derived from a functionalization reaction of a hydroxylated POS with a suitable crosslinker and in the presence of a functionalization catalyst, and there may still be some POS chains with hydroxylated terminations. Preferably, the POS according to the invention are completely devoid of it.

The subject of the invention is therefore a one-component polyorganosiloxane (POS) composition which is stable to storage in the absence of moisture and crosslinking, in the presence of water, of elastomer, composition comprising at least one crosslinkable linear polyorganopolysiloxane POS, a filler (a reinforcing filler and / or a semi-reinforcing filler and / or a filler) and a crosslinking catalyst, the POS having non-hydroxylated functionalized ends, in particular alkoxy, oxime, acyl and / or enoxy ends, preferably alkoxy, the composition being substantially or completely free of hydroxylated POS, ie in particular less than 10 μmol OH per g of composition, and being characterized in that the catalyst comprises a vanadium compound and a titanium compound.

The titanium and vanadium compounds act synergistically to lead to fast surface and fast-setting kinetics, even when the POS is of the alkoxy type and / or when a carbonate-type semi-reinforcing filler is present.

In a preferred embodiment, said composition is characterized in that it comprises:

-A- at least one crosslinkable linear polyorganopolysiloxane A of formula:

in which :

the substituents R ¹ , which may be identical or different, each represent a substituted or unsubstituted, aliphatic, cyclanic or aromatic saturated or unsaturated C 1 to C 3 hydrocarbon monovalent radical;

the substituents R _{1, which are} identical or different, each represent a substituted or unsubstituted, aliphatic, cyclanic or aromatic, saturated or unsaturated C 1 to C 3 hydrocarbon radical;

the functionalization substituents R ^fo , identical or different, each represent: An oxime residue of formula: with R ³ independently representing linear or branched C 1 to C 6 alkyl; C ₃ -C ₈ cycloalkyl, C ₂ -C ₈ alkenyl, preferably selected from the group consisting of: methyl, ethyl, propyl, butyl, vinyl, allyl;

An alkoxy residue of formula:

R ⁴ O (CH ₂ CH ₂ COb - where R ⁴ represents independently a linear or branched C 1 to C 6 alkyl, a C 3 to C 8 cycloalkyl, preferably selected from the group consisting of: methyl, ethyl, propyl, butyl; and methylglycol, and b = 0 or 1;

An acyl residue of formula:

O

R ⁵ CO with R ⁵ representing a substituted or unsubstituted, substituted or unsubstituted, aliphatic, cyclanic or aromatic, saturated or unsubstituted hydrocarbon monovalent hydrocarbon radical,

• an enoxy residue of formula: R ⁶ R ⁶ C = CR ⁶ -O- with the R ^6, identical or different, representing hydrogen or a saturated monovalent hydrocarbon radical or not C _j to C) 3, branched or no, substituted or unsubstituted, aliphatic, cyclanic or aromatic,

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;

- a is zero or 1;

B optionally at least one polyorganosiloxane resin B functionalized with at least one radical R ^f0 corresponding to the definition given above and having, in its structure, at least two different siloxyl units chosen from those of formulas

(R ₃ SiO ₁ V ₂ (unit ^M ). (R ¹ ) 2 ^SiO 2/2 (unit ^D ), R ¹ SiO _3/2 (unit T) and SiO ₂ (unit Q), at least one these units being a T or Q unit, the radicals R ¹ , which may be identical or different, have the meanings given above with respect to formula (A), said resin having a weight content of functional radicals R ^f0 ranging from 0.1 to 10%, it being understood that part of the radicals R ¹ are radicals R ^f0 ;

-C- optionally at least one crosslinker C of formula:

(R ²⁾ _a Si [R ^f0] _4-a with R ^2, R ^f0 and a being as defined above,

-D- optionally at least one non-reactive and non-functional linear polydiorganosiloxane D ^f0 and of formula:

(R ¹ J ₃ SiO Si (R ¹ ) ₃ (D)

in which: the substituents R ^" ', which are identical or different, have the same meanings as those given above for the polyorganosiloxane A of formula (A); ma has a value sufficient to give the polymer of formula (D) a dynamic viscosity at 25 ° C ranging from 10 to 200,000 mPa.s; E-an effective amount of a vanadium compound E 'and a titanium compound E "as a crosslinking catalyst or accelerator; A reinforcement load and / or a semi-reinforcing filler and / or a filling load F;

Optionally, at least one auxiliary agent H.

The vanadium compound E 'can be a vanadium compound with oxidation state 3 (V ³ ), 4 (V ⁴ ) or 5 (V ⁵ ).

In a first embodiment, the compound E 'is a compound of V ⁵ , and in particular a compound of formula (E' i): X ₃ VO in which the radicals X, which are identical or different, are chosen from: ligands X radical radicals with 1 electron, in particular alkoxy or halogen atom, and radical LX ligands with 3 electrons, in particular a ligand derived from acetylacetone, a β-ketoester, a malonic ester, an allyl compound , a carbamate, a dithiocarbamate, a carboxylic acid.

The definition of ligands is taken from the book "Organometallic Chemistry" by Didier Astruc, published in 2000 by EDP Sciences, see in particular Chapter 1, "The monometallic complexes", pages 31 and following.

Alkoxy group more particularly denotes a group OR in which R is a linear or branched C ₁ -C ₁₃ , in particular C ₁ -C ₈ , preferably C ₁ -C ₄ , alkyl, or a C ₃ -C ₈ cycloalkyl. As compounds of the V ⁵ corresponding to this definition, there may be mentioned by way of example vanadyl trialkoxylates, preferably the following: [(CHa) ₂ CHO] ₃ VO (vanadium oxotriisoproxide), (CH ₃ CH ₂ O) ₃ VO, [(CH ₃ ) ₃ CO] ₃ VO, [(CH ₃ CH ₂ ) (CH ₃ ) CHO] ₃ VO, [(CHa) ₂ (CH ₂ ) CHO] ₃ VO.

As a halogen atom, mention may be made of Cl ₁ Br and F, and CI is preferred.

As a derivative of acetylacetone or an allyl compound, there may be mentioned especially the acetylacetonato (CH ₃ COCHCOCH ₃ ) and allyl (CH ₂ = CH-CH ₂ ) radicals.

In another embodiment, the compound E 'is a compound of V ⁴ , and in particular a compound of formula (E' ₂ ): X ₂ VO in which the radicals X, which are identical or different, are chosen from: ligands X radical radicals with 1 electron, in particular alkoxy or halogen atom, as described above, and radical LX ligands with 3 electrons, in particular a ligand derived from acetylacetone, a β-ketoester, a malonic ester, an allyl compound, a carbamate, a dithiocarbamate, a carboxylic acid.

By way of example of such a compound (E ' ₂ ), VOHa ₂ may be mentioned (Ha = halogen, eg Br, F, Cl), in particular VOCl ₂ , [(CH ₃ ) ₂ CHO] ₂ VO, ( CH ₃ CH ₂ O) ₂ VO, [(CH ₃ ) ₃ CO] ₂ VO, [(CH ₃ CH ₂ ) (CHa) CHO] ₂ VO, [(CHa) ₂ (CH ₂ ) CHO] ₂ VO.

In another embodiment, the compound E 'is a compound of V ⁴ of formula (E' ₃ ): VX ₄ in which the X, which are identical or different, are chosen from halogens, in particular Br, F or Cl, and the OR alkoxy with R representing in particular a linear or branched C ₁ -C ₁₃ alkyl, in particular C ₁ -C ₈ , preferably C ₁ -C ₄ alkyl, or a C ₃ -C ₈ cycloalkyl ring.

By way of example of such a vanadium compound (E ' ₃ ), mention may be made of the following compounds: [(CHa) ₂ CHO] ₄ V, (CH ₃ O) ₄ V, (CH ₃ CH ₂ O) ₄ V, [(CH ₃ ) ₃ CO] ₄ V,

[(CH ₃ CH ₂ ) (CH ₃ ) CHO] ₄ V, [(CH ₃ ) ₂ (CH ₂ ) CHO] ₄ V.

In yet another embodiment, the compound E 'is a compound of V ³ , and in particular a compound of formula (E' ₄ ): XVO in which the radical X is a radical LX ligand with 3 electrons, in particular a ligand derived from acetylacetone, a β-ketoester, a malonic ester, an allyl compound, a carbamate, a dithiocarbamate, a carboxylic acid. As a derivative of acetylacetone or an allyl compound, mention may in particular be made of the ligands acetylacetonato (CH ₃ COCHCOCH ₃ ) and allyl (CH ₂ = CH-CH ₂ ). In yet another embodiment, the compound E '(E' ₅ ) is a compound of V ⁵ with radical L ₂ X ligands with 5 electrons, in particular dienyls, in particular cyclopentadienyl, eg (C ₅ H ₅ ) ₂ V or (C ₅ Hs) ₂ VCI ₂ .

The titanium compound E "may be an organic derivative of titanium selected from the group consisting of:

+ monomers Ε of formula:

Ti [(OCH ₂ CH ₂ ) _c OR ⁷ ] ₄ in which: the substituents R ⁷ , which may be identical or different, each represent a linear or branched C ₁ -C ₁₂ alkyl radical; c represents zero, 1 or 2; preferably with the conditions according to which, when the symbol c represents zero, the alkyl radical R ⁷ has from 2 to 12 carbon atoms, and when the symbol c represents 1 or 2, the alkyl radical R ⁷ has from 1 to 4 atoms of carbon ;

+ polymers E " ₂ resulting from the partial hydrolysis of the monomers E" i in which the symbol R ⁷ has the abovementioned meaning with the symbol c representing zero.

Examples of R ⁷ symbols in the organic derivatives of titanium E "i include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, 2-ethylhexyl, octyl, decyl and dodecyl radicals. .

As concrete examples of monomers Ei may be mentioned: ethyl titanate, propyl titanate, isopropyl titanate, butyl titanate, 2-ethylhexyl titanate, octyl titanate, titanate decyl, dodecyl titanate, titanate, β-methoxyethyl, ^{β-ethoxyethyl} titanate titanate, β-propoxyethyl, the titanate of the formula Ti [(OCH ₂ CH ₂₎ ₂ OCH _3] _4. As Concrete examples of polymers E " _{2 resulting} from the partial hydrolysis of the monomeric titanates can be mentioned: polymers E" _{2 resulting} from the partial hydrolysis of isopropyl, butyl or 2-ethylhexyl titanates.

For the embodiment of the invention, as the titanium compound, the following monomeric titanates E-1 are preferably used, taken alone or as a mixture: ethyl titanate, propyl titanate, isopropyl titanate, titanate butyl (n-butyl) composition The composition according to the invention may comprise: from 0.01 to 1% by weight of vanadium metal, preferably from 0.05 to 0.3

%

from 0.01 to 1% by weight of metal titanium, preferably from 0.03 to 0.25%, these percentages being expressed relative to the weight of the total composition.

The catalyst may be in the solid or liquid state. It may be incorporated alone or in a suitable anhydrous solvent, for example a silicone oil.

The composition according to the invention has all the properties that are interesting and specific to this type of product and, moreover, has a rapid surface and core crosslinking kinetics even in the presence of an alkoxy POS and / or a charge based on carbonate. It can be used to produce elastomer parts having conventional thicknesses, namely in particular thicknesses ranging from 0.5 or 1 mm to a few centimeters. Typically in the field of joints, the thickness can be between 0.01 and 2 cm.

In addition, the composition according to the invention is economical and leads to crosslinked elastomers having advantageous mechanical properties and adhering to many supports.

The composition according to the invention corresponds to an embodiment in which the essential constituent, namely the POS A is functionalized at its ends (usually initially carrying hydroxyl functions) by functionalization radicals R ^f0 from a silane The OH of the POS A precursor reacted with the R ^f0 of the cross-linking silane C by condensation.

POS A is functionalized according to techniques known to those skilled in the art. This functionalized POS A corresponds to a stable form in the absence of moisture, the one-component sealant considered here. In practice, this stable form is that of the composition packaged in hermetically sealed cartridges, which will be opened by the operator during use and which will allow him to apply the sealant on all desired media.

The hydroxylated precursor A "of the functionalized POS A R ^f0 is generally an α, ω-hydroxylated polydiorganosiloxane of formula:

with R ¹ and n as defined above in formula (A). The optional functionalized POS B resin R ^f0 may be produced in the same way as the functionalized POS A R ^f0 , by condensation with a crosslinking silane C bearing functionalization radicals R ^f0 .

The precursor of the functionalized POS B resin R ^f0 may be a hydroxylated POS B 'resin as defined above for B, with the exception that part of the radicals R ¹ correspond to OH.

The composition according to the invention may be of the acid type (acetoxy ...) or even of the neutral type (enoxy, oxime, alkoxy, etc.).

According to a preferred arrangement of the invention, the silicone composition concerned is rather of neutral type, for example oxime or alkoxy, which means that the functionalization substituents R ^fo of formulas A, B and C, which are identical or different, each represent:

An oxime residue of formula: with R ³ independently representing a linear or branched alkyl C _j -C _β; C ₃ -C ₈ cycloalkyl, C ₂ -C ₈ alkenyl, preferably selected from the group consisting of: methyl, ethyl, propyl, butyl, vinyl, allyl;

And / or an alkoxy residue of formula:

R ⁴ O (CH ₂ CH ₂ O) _b - with R ⁴ independently representing linear or branched C ₁ -C ₈ alkyl; C ₁ -C ₈ cycloalkyl; preferably selected from the group consisting of: methyl, ethyl, propyl, butyl and methylglycol, and b = 0 or 1.

In a more preferred embodiment of the invention, the functionalization substituents R ^f0 are of the alkoxy type and correspond to the formula R ⁴ O (OCH ₂ CH ₂ ) _b as defined above.

Among the H auxiliaries or additives of particular interest for the composition according to the invention, mention may be made of adhesion promoters.

Thus the POS composition according to the invention may comprise at least one adhesion promoter H1, in particular non-nucleophilic and non-amine, or it is a tertiary amine, preferably selected from organosilicon compounds bearing both :

(1) one or more hydrolysable groups bonded to the silicon atom and (2) one or more organic groups substituted with radicals chosen from the group of (meth) acrylate, epoxy and alkenyl radicals, and even more preferably from the group comprising:

vinyltrimethoxysilane (VTMO),

3-glycidoxypropyltrimethoxysilane (GLYMO),

methacryloxypropyltrimethoxysilane (MEMO),

propyltrimethoxysilane,

methyltrimethoxysilane,

ethyltrimethoxysilane,

vinyltriethoxysilane,

methyltriethoxysilane,

propyltriethoxysilane,

tetraethoxysilane,

tetrapropoxysilane,

tetraisopropoxysilane, or polyorganosiloxane oligomers containing such organic groups at a content greater than 20%.

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.

To further detail the nature of the constitutive elements of the composition according to the invention, it is important to specify that the substituents R 1 of functionalized POS A polymers, functionalized B resins R ^{f 0} and optional nonfunctionalized D polymers can be selected in the US Pat. group formed by:

the alkyl and haloalkyl radicals having from 1 to 13 carbon atoms,

cycloalkyl and halogenocycloalkyl radicals having from 5 to 13 carbon atoms,

alkenyl radicals having 2 to 8 carbon atoms,

mononuclear aryl and haloaryl radicals having from 6 to 13 carbon atoms,

cyanoalkyl radicals whose alkyl members have 2 to 3 carbon atoms, the methyl, ethyl, propyl, isopropyl, n-hexyl, phenyl, vinyl and 3,3,3-trifluoropropyl radicals being particularly preferred. More specifically, and without limitation, the substituents R ¹ mentioned above for the POS A and D polymers (optional) comprise:

alkyl and haloalkyl radicals having 1 to 13 carbon atoms, such as the methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, 2-ethylhexyl, octyl, decyl or 3,3,3-trifluoropropyl radicals, 4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,

cycloalkyl and halogenocycloalkyl radicals having 5 to 13 carbon atoms such as cyclopentyl, cyclohexyl, methylcyclohexyl, propylcyclohexyl, 2,3-difluorocyclobutyl, 3,4-difluoro-5-methylcycloheptyl radicals,

alkenyl radicals having 2 to 8 carbon atoms, such as vinyl, allyl and buten-2-yl radicals,

mononuclear aryl and haloaryl radicals having from 6 to 13 carbon atoms, such as the phenyl, tolyl, xylyl, chlorophenyl, dichlorophenyl and trichlorophenyl radicals,

cyanoalkyl radicals whose alkyl members have 2 to 3 carbon atoms, such as the β-cyanoethyl and γ-cyanopropyl radicals.

As concrete examples of siloxyl units D: (R 1) ₂ SiO ₂ Z ₂ present in the functionalized diorganopolysiloxanes A ^{f 0} of formula (A) and in the optional non-reactive diorganopolysiloxanes D of formula (D), mention may be made of :

(CH ₃ ) ₂ Si0,

CH ₃ (CH ₂ = CH) SiO,

CH ₃ (C ₆ H ₅ ) SiO,

(C ₆ H ₅ ) ₂ SiO,

CF ₃ CH ₂ CH ₂ (CH ₃ ) SiO,

NC-CH ₂ CH ₂ (CH ₃ ) SiO,

NC-CH (CH ₃ ) CH ₂ (CH ₂ = CH) SiO,

NC-CH ₂ CH ₂ CH ₂ (C ₆ H ₅ ) SiO.

It should be understood that, in the context of the present invention, it is possible to use as functionalized polymers A of formula (A) a mixture consisting of several polymers - preferably initially hydroxylated, then functionalized R ^f0 -, which differ from each other value of the viscosity and / or the nature of the substituents bonded to the silicon atoms. It must be indicated that the functionalized polymers A of formula (A) may include T siloxyl units of formula R ^ SiO _{_3/2} and / or Siloxy units Q: SiC> 4/2, in the proportion of at most 1% (this% expressing the number of units T and / or Q per 100 silicon atoms). The same remarks apply to non-functionalized and non-reactive D (optional) polymers of formula (D).

The substituents R 1 of the functionalized polymers A and the non-reactive and non-functionalized polymers D (optional) advantageously used, because of their availability in industrial products, are the methyl, ethyl, propyl, isopropyl, n-hexyl, phenyl and vinyl radicals. and 3,3,3-trifluoropropyl. More preferably, at least 80% by number of these substituents are methyl radicals.

Functionalized polymers A having a dynamic viscosity at 25 ° C ranging from 500 to 1,000,000 mPa.s and preferably ranging from 2,000 to 200,000 mPa are used. s.

With regard to non-functionalized polymers D (optional), they exhibit a dynamic viscosity at 25 ° C. ranging from 10 to 200,000 mPa.s and preferably ranging from 50 to 150,000 mPa.s.

The non-reactive and non-functionalized polymers D, when used, can be introduced in whole or in several fractions and at several stages or at a single stage of the preparation of the composition. Any fractions may be the same or different in terms of nature and / or proportions. Preferably, D is introduced in its entirety at a single stage.

As examples of substituents PJ of functionalized POS B resins R ^f0 which are suitable or which are advantageously used, mention may be made of the various radicals R 1 of the type mentioned above, for the functionalized polymers A, above. These silicone resins are branched polyorganosiloxane polymers. well known whose methods of preparation are described in many patents. As concrete examples of resins that may be used, mention may be made of MQ, MDQ, TD and MDT resins.

Preferably, examples of resins that can be used include functionalized POS B resins R ^f0 not comprising, in their structure, a Q-unit. More preferentially, examples of resins that can be used include resins TD and MDT. functionalized compounds comprising at least 20% by weight of T units and having a weight content of R ^f ° group ranging from 0.3 to 5%. Even more preferably, resins of this type are used, in the structure of which at least 80% by number of the substituents R 1 are methyl radicals. The functional groups R ^fo of the resins B may be borne by the units M, D and / or T. As regards the functionalized POS A and the C-crosslinking agents, there may be mentioned as concrete examples of substituents R ² which are particularly suitable, the same radicals as mentioned above, for the substituents R ¹ of the functionalized polymers A.

With regard to the substituents R ³ , R ⁴ and R ⁵ constituting the radicals of functionalization R ^f0 , it will be mentioned that the C ₁ -C ₄ alkyl radicals, such as the methyl, ethyl, propyl, isopropyl and n-butyl radicals, are especially appropriate.

According to the preferred embodiment of the composition, according to the invention, the radicals R ^f0 used for the functionalization of the initially hydroxylated POS are of alkoxy type and even more preferably are derived from silane crosslinking agents C selected from the group comprising

If (OCH ₃ ) ₄

If (OCH ₂ CH ₃ ) ₄

If (OCH ₂ CH ₂ CHs) ₄

(CH ₃ O) ₃ SiCH ₃

(C ₂ H ₅ O) ₃ SiCH ₃

(CH ₃ O) ₃ Si (CH = CH ₂ )

(C ₂ H ₅ O) ₃ If (CH = CH ₂ )

(CH ₃ O) ₃ Si (CH ₂ -CH = CH ₂ )

(CH ₃ O) ₃ If [CH ₂ - (CH ₃ ) C = CH ₂ ]

(C ₂ H ₅ O) ₃ Si (OCH ₃ )

If (OCH ₂ -CH ₂ -OCH ₃ ) ₄

CH ₃ Si (OCH ₂ -CH ₂ -OCH ₃ ) ₃

(CH ₂ = CH) Si (OCH ₂ CH ₂ OCH ₃ ) ₃

C ₆ H ₅ Si (OCH ₃ ) ₃

C ₆ H ₅ Si (OCH ₂ -CH ₂ -OCH ₃ ) ₃ .

According to one embodiment of the invention, the composition comprising POS A and the catalyst may also comprise at least one crosslinking agent C as described above.

The filler F can be present in an amount ranging from 5 to 50% by weight relative to the total composition, preferably between 15 and 40%. According to a first embodiment, the filler F comprises at least one filler based on carbonate serving as reinforcing filler or semi-reinforcing filler.

By carbonate filler is meant a filler comprising at least one alkali metal or alkaline earth metal carbonate. It will preferably be an alkaline earth metal carbonate, preferentially calcium. Preferably, such fillers having an average particle size of less than or equal to 0.5 μm are employed. It is possible to use industrial carbonates such as precipitation carbonates, eg calcium carbonate precipitation. 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 may then have a high BET specific surface area greater than 5 m ² / g. Preferably, such carbonates having an average particle size or 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 μm, are preferably used. m ² / g, preferably from 15 to 30 m ² / g. The carbonates used may contain some residual moisture moisture, which is typically in the range of 0.1 to 0.6%.

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.

According to a second embodiment, the filler F comprises at least one siliceous reinforcing filler, and in particular an amorphous silica. As amorphous silica capable of being used in the invention, all the precipitated or pyrogenic silicas (or fumed silicas) known to those skilled in the art are suitable. Of course, it is also possible to use blends of different silicas. These silicas may have an average particle size of less than or equal to 0.1 μm.

Precipitation silicas in the form of powder, powdered combustion silicas or mixtures thereof are preferred; their BET surface area is generally greater than 40 m 2 / g and preferably between 100 and 300 m 2 / g; more preferentially, the combustion silicas in the form of powder are used.

These siliceous fillers can be surface-modified by treatment with the various organosilicon compounds usually employed for this purpose. Thus, these organosilicon compounds may be organochlorosilanes, diorganocyclopolysiloxanes, hexaorganodisiloxanes, hexaorganodisilazanes or diorganocyclopolysilazanes (patents FR 1 126 884, FR 1 136 885, FR 1 236 505, GB 1 024 234). The treated fillers contain, in most cases, from 3 to 30% of their weight of organosilicic compounds.

Other siliceous fillers that may be mentioned include quartz and silicas or diatomaceous earths, in particular having an average particle size of less than or equal to 0.1 μm.

In the present application, the viscosity of the oils is a Newtonian dynamic viscosity at 25 ° C., measured using a BROOKFIELD viscometer according to the indications of 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.

A combination of filler based on carbonate and siliceous filler, in particular silica, is also within the scope of the invention.

In the context of the present invention, it is possible to use or combine other fillers, such as stuffing fillers or semi-reinforcing fillers. There may be mentioned opacifying white fillers, such as titanium or aluminum oxides, black smokes; crushed quartz, diatomaceous earth silicas, calcined clay, rutile type titanium oxide, iron, zinc, chromium, zirconium, magnesium oxides, the various forms of alumina (hydrated or not) ), boron nitride, lithopone, barium metaborate, cork powder, sawdust, phthalocyanines, mineral and organic fibers, organic polymers (polytetrafluoroethylene, polyethylene, polypropylene, polystyrene, polyvinyl chloride) . In practice, these additional charges may be in the form of inorganic and / or organic products more coarsely divided, of average particle size greater than 0.1 μm, in particular greater than 1 μm and generally of the order of 10 to several tens of μm.

It is possible to use natural carbonates such as natural calcium carbonate, the particle size of which is generally greater than 1 μm, and it is preferred in the context of the present invention those whose average particle size is less than or equal to 10 μm. μm, eg between 1 and 10 μm.

The purpose of introducing the fillers is to impart good mechanical and rheological characteristics to the elastomers resulting from the hardening of the compositions in accordance with the invention. In combination with these fillers can be used inorganic and / or organic pigments as well as agents improving the thermal resistance (salts and oxides of rare earths such as ceric oxides and hydroxides) and / or the flame resistance of the elastomers. Among the agents improving the flame resistance can be mentioned halogenated organic derivatives, organic phosphorus derivatives, platinum derivatives such as chloroplatinic acid (its reaction products with alkanols, ether-oxides), complexes platinum chloride-olefins.

According to a preferred characteristic of the invention, the single-component POS composition comprises:

100 parts by weight of linear diorganopolysiloxane (s) A functionalized with R ^f0 ,

from 0 to 30, preferably from 5 to 15, parts by weight of hydroxylated resin (s) B,

from 2 to 15, preferably from 3.5 to 12, parts by weight of crosslinking agent (s) C,

from 0 to 60, preferably from 5 to 60, parts by weight of linear non-functionalized diorganopolysiloxane (s) and non-reactive D,

from 0.1 to 10, preferably from 0.5 to 6, parts by weight of crosslinking / curing catalyst E '+ E "

from 2 to 250, preferably from 10 to 200, parts by weight of filler, e.g. of filler based on carbonate and / or silica F, and

from 0 to 20, in particular from 0.1 to 20, preferably from 0.1 to 10, parts by weight of adhesion promoter H.

Other auxiliary agents and customary additives may be incorporated into the composition according to the invention; these are chosen according to the applications in which said compositions are used.

The compositions in accordance with the invention harden at room temperature and especially at temperatures of between 5 and 35 ^° C. in the presence of moisture.

These compositions can be used for multiple applications such as grouting in the building industry, assembly and bonding of various materials (metals, plastics such as PVC, PMMA, natural and synthetic rubbers; wood, cardboard, earthenware, brick, glass, stone, concrete, masonry), and this in the context of the construction industry as well as that of the automobile, appliance and home appliance industries. electronic.

According to another of its aspects, the subject of the present invention is also an elastomer, in particular an elastomer capable of adhering to various substrates, obtained by crosslinking and hardening of the silicone sealant composition. monocomponent described above, containing a vanadium compound and a titanium compound, as described supra.

The monocomponent organopolysiloxane compositions in accordance with the present invention are prepared in the absence of moisture by operating in a closed reactor equipped with stirring, in which a vacuum can be evacuated, if necessary, and then optionally replacing the air expelled by an anhydrous gas, for example by nitrogen.

As examples of equipment, mention may be made of: slow dispersers, blade, propeller, arm, anchor mixers, planetary mixers, hook mixers, single-screw or multi-screw extruders.

The subject of the invention is also the use of a vanadium compound and a titanium compound as catalyst for a storage-stable polyorganosiloxane (POS) composition in the absence of moisture and a crosslinking agent, in the presence of water, made of elastomer, composition comprising at least one cross-linkable linear POS polyorganopolysiloxane and a reinforcing filler and / or a semi-reinforcing filler and / or a filler, in particular a filler based on carbonate, the POS having functionalized ends non-hydroxylated, in particular alkoxy, oxime, acyl and / or enoxy ends, preferably alkoxy ends, the composition being essentially, preferably totally free of hydroxylated POSs. In the context of this use, the vanadium and titanium compounds, the POS, the filler and any other constituents, in their various forms, are as described above.

The invention will be better understood with the aid of the following nonlimiting examples.

EXAMPLES

Comparative Example 1: Formulation of RTV1 catalyzed by a titanium-based catalyst

In the tank of a uniaxial mixer "butterfly" are charged with 677 g of α, ω-hydroxylated polydimethylsiloxane oil having a viscosity of approximately 20000 mPa.s, 66 g of α, ω-trimethylsilylated polydimethylsiloxane oil having a viscosity of approximately 100 mPa.s, 55 g of a black coloring base (this coloring base consists of 83% of α, ω-trimethylsilylated polydimethylsiloxane oil and 17% of carbon black), 7.42 g of Breox B225®, thixotroping agent sold by Laporte Performance Chemicals and 67.6 g of vinyltrimethoxysilane. The mixture is mixed at 140 rpm for about 5 minutes and 6 g of a functionalization catalyst based on lithium are introduced into the tank. The functionalization reaction is allowed to proceed for 5 minutes with stirring at 330 rpm. Then, 28.9 g of amorphous silica marketed by the company Degussa under the AE150® name is first incorporated at reduced stirring speed (140 rpm), then faster (330 rpm for 5 min) to perfect its dispersion in the mixture. 421 g of treated calcium carbonate, marketed by Solvay under the name Winnofil SPM®, are then added. The calcium carbonate is dispersed in the formulation with vigorous stirring (330 rpm) for 6 minutes. The mixture then undergoes a first devolatilization phase of 6 min under a vacuum of about 60 mbar and with moderate stirring (140 rpm). 23 g of a mixture containing 16.7% by weight of methacryloxypropyltrimethoxysilane (MEMO) and 83.3% of butyl titanate (TBOT) are then added. After mixing for 4 minutes at 330 rpm, the medium is devolatilized a second time for 6 min, under a vacuum of about 60 mbar and with reduced stirring at 140 rpm, before being packaged in cartridges.

The characteristics of this formulation thus obtained are collated in Table 1 under the reference "comparative".

Example 2 Formulation of a Co-Catalyzed RTV1

Several tests 1 to 6 were carried out with a co-catalytic system based on titanium and vanadium. They all follow the same procedure as Example 1. They differ only in the composition of the mixture introduced after the first phase of devolatilization. This mixture comprises MEMO, TBOT and vanadium oxotriisopropoxide in proportions such that it leads to formulations, the respective contents of each of these three constituents are listed in Table 1. In this table, are also reported the contents of these constituents in the formulation of Comparative Example 1, when present.

Table 1:

Results: The results characterizing the crosslinking kinetics of all the formulations are summarized in Table 2.

The characteristics that make it possible to judge the kinetics of crosslinking are three in number:

Skin Training Time (TFP) which qualifies the speed of surfacing.

- Shore A hardness at 24 hours (24h DSA)

- Shore A hardness at 7 days (DSA 7j)

The last two give an overall picture of the progress of formation of the elastomeric network respectively at 24 hours and 7 days. Their ratio is directly representative of the kinetics of crosslinking, for a given formulation. Table 2:

It is clear from Table 2 that the use of a Ti and V-based co-catalyst system makes it possible to improve the crosslinking kinetics. Thus, Titanium-only catalysis allows an efficient construction of the network seen through the evolution of the DSA, but suffers from a prohibitive slowness of the catch on the surface. The combination of the two metals results in a net improvement of the surface catch with a good evolution of the DSA. It should be understood that the invention defined by the appended claims is not limited to the particular embodiments indicated in the description above, but encompasses variants that do not depart from the scope or spirit of the present invention. present invention.

Claims

1-Composition polyorganosiloxane (POS) monocomponent stable storage in the absence of moisture and crosslinking, in the presence of water, elastomer, composition comprising at least one crosslinkable linear polyorganopolysiloxane POS, a filler and a crosslinking catalyst, the POS having functionalized ends of alkoxy, oxime, acyl and / or enoxy, preferably alkoxy, the composition being substantially free of hydroxylated POSs and characterized in that the catalyst comprises a vanadium compound and a titanium compound.

2- Composition according to claim 1, characterized in that it comprises:

-A- at least one crosslinkable linear polyorganopolysiloxane A of formula:

wherein: the substituents R 1, which are identical or different, each represent a substituted or unsubstituted, aliphatic, cyclanic or aromatic monovalent hydrocarbon radical which is saturated or unsaturated; the substituents R _{1, which are} identical or different, each represent a substituted or unsubstituted, aliphatic, cyclanic or aromatic saturated monovalent hydrocarbon radical C 1 to C 3; the functionalization substituents R ^fo , identical or different, each represent:

An oxime residue of formula: with R ³ independently representing linear or branched C 1 -C 5 alkyl; C ₃ -C ₈ cycloalkyl, C ₂ -C ₈ alkenyl,

An alkoxy residue of formula: with R ⁴ representing independently a linear or branched C 1 to C 6 alkyl; C3-C8 cycloalkyl and b = 0 or 1; An acyl residue of formula:

with R ⁵ representing a saturated or unsubstituted, substituted or unsubstituted, aliphatic, cyclanic or aromatic, saturated or unsubstituted hydrocarbon-based monovalent hydrocarbon radical,

An enoxy residue of formula: R ⁶ R ⁶ C = CR ^B -O- with R ⁶ , which may be identical or different, representing hydrogen or a monovalent hydrocarbon radical saturated or unsaturated with C ₁ to C 3, branched or no, substituted or unsubstituted, aliphatic, cyclanic or aromatic,

- a is zero or 1;

(R ₃ SiO ₁ Z ₂ (unit M), (R ¹ ) ₂ SiO 2/2 (unit D), R ¹ SiO ₃₇₂ (unit T) and SiO ₂ (unit Q), at least one of these units being a T or Q unit, the radicals R ¹ , which are identical or different, having the meanings given above with respect to formula (A), said resin having a weight content of functional radicals R ^f0 ranging from 0.1 to 10%, it being understood that part of the radicals R ¹ are radicals R ^f0 ;

-C- optionally at least one crosslinker C of formula: with R ² , R ^f0 and a being as defined above,

R ¹

(R ¹ ) ₃ SiO - - Si - O - Sii Si (R ¹ ) ₃ (D)

R ¹ m in which: the substituents R 1, which are identical or different, have the same meanings as those given above for the polyorganosiloxane A of formula (A);

m is of sufficient value to give the polymer of formula (D) a dynamic viscosity at 25 ° C. ranging from 10 to 200,000 mPa.s;

-E- an effective amount of a vanadium compound E 'and a titanium compound E "as a crosslinking catalyst or accelerator;

-F- a charge F;

Optionally, at least one auxiliary agent H.

3. The composition of claim 1 or 2, wherein the POS A has alkoxy ends.

4. Composition according to claim 1, 2 or 3, wherein the filler F comprises a siliceous or carbonate-based reinforcing or semi-reinforcing filler.

5. Composition according to one of claims 1 to 4, characterized in that the vanadium compound is a vanadyl trialkoxylate.

6. Composition according to one of claims 1 to 4, characterized in that the vanadium compound is chosen from: [(CH ₃ ) ₂ CHO] ₃ VO (CH ₃ CH ₂ O) ₃ VO, [(CH _S ) ₃ CO] ₃ VO, [(CH ₃ CH ₂ ) (CH ₃ ) CHO] ₃ VO, [(CH ₃ ) ₂ (CH ₂ ) CHO] ₃ VO, VOCI ₂ , [(CHa) ₂ CHO] ₂ VO, (CH ₃ CH ₂ O) ₂ VO, [(CH ₃ ) ₃ CO] ₂ VO, [(CH ₃ CH ₂ ) (CH ₃ ) CHO] ₂ VO ₁ [(CH ₂ ) ₂ (CH ₂ ) CHO] ₂ VO , [(CH ₃ ) ₂ CHO] ₄ V, (CH ₃ O) ₄ V, (CH ₃ CH ₂ O) ₄ V, [(CH ₃ ) ₃ CO] ₄ V, [(CH ₃ CH ₂ ) (CH) ₃ ) CHO] ₄ V, [(CHa) ₂ (CH ₂ ) CHO] ₄ V.

7. Composition according to one of claims 1 to 6, characterized in that the titanium compound has the following formula:

Ti [(OCH ₂ CH ₂ ) _c OR ⁷ ] ₄ in which:

the substituents R ⁷ , which may be identical or different, each represent a linear or branched C ₁ to C ₁₂ alkyl radical; c represents zero, 1 or 2;

preferably with the conditions according to which, when the symbol c represents zero, the alkyl radical R ⁷ has from 2 to 12 carbon atoms, and when the symbol c represents 1 or 2, the alkyl radical R ⁷ has from 1 to 4 carbon atoms; or a polymer resulting from the partial hydrolysis of these monomers with the symbol c representing zero.

8. Composition according to claim 7, characterized in that the titanium compound is chosen from: ethyl titanate, propyl titanate, isopropyl titanate, butyl titanate, 2-ethyl hexyl titanate , octyl titanate, decyl titanate, dodecyl titanate, β-methoxyethyl titanate, β-ethoxyethyl titanate, β-propoxyethyl titanate, titanate of formula Ti [(OCH ₂ CH ₂ ) ₂ θCH ₃ ] ₄ , the polymers resulting from the partial hydrolysis of isopropyl, butyl or 2-ethylhexyl titanates.

9. Composition according to one of the preceding claims, characterized in that it comprises:

from 0.01 to 1% by weight of vanadium metal, preferably from 0.05 to 0.3

%

from 0.01 to 1% by weight of metal titanium, preferably from 0.03 to 0.25%.

10. Composition according to any one of the preceding claims, characterized in that the substituents R ¹ of functionalized POS A polymers, functionalized B resins R ^f0 and optional non-functionalized and unreactive polymers D are selected from the group consisting of:

the alkyl and haloalkyl radicals having from 1 to 13 carbon atoms,

cycloalkyl and halogenocycloalkyl radicals having from 5 to 13 carbon atoms,

alkenyl radicals having 2 to 8 carbon atoms,

mononuclear aryl and haloaryl radicals having from 6 to 13 carbon atoms,

cyanoalkyl radicals whose alkyl members have 2 to 3 carbon atoms, the methyl, ethyl, propyl, isopropyl, n-hexyl, phenyl, vinyl and 3,3,3-trifluoropropyl radicals being particularly preferred.

11. Elastomer capable of adhering to different substrates and obtained by crosslinking and curing the composition according to any one of the preceding claims.