Silicone composition crosslinkable into elastomer by hydrosilylation, in the presence of carbene-based metal catalysts, and catalysts

Description of the invention

The invention relates to a hydrosilylating crosslinkable silicone composition, a metal complex and the use of a metal complex.

The invention relates to the catalysis of the hydrosilylation reaction, in particular the hydrosilylation of ethylenically and / or acetylenically unsaturated compounds (e.g. olefins or acetylenic derivatives), in particular polyorganosiloxanes (POS) containing Si-H and POS groups containing Si- groups (ethylene or acetylenic unsaturation) ).

In particular, the invention relates to crosslinkable / preferably silicone compositions - preferably elastomers - by hydrosilylating at least one polyorganosiloxane -A- (POS) containing one or more ethylenically and / or acetylenically unsaturated groups using at least one a polyorganohydrosiloxane -B- in the presence of a metal catalyst -C- and optionally containing at least one inhibitor -D-hydrosilylation reaction.

Typically, hydrosilylation reactions which enable cross-linking of silicones are catalyzed by platinum catalysts (US 2,823,218, US 2,970,150). In practice, so far most of the industrial scale hydrosilylation reactions are catalyzed by a Karstedt solution, which contains platinum complexes in the oxidation state of 0. The idealized general formula of the Karstedt complex applies to Pt2 (tetramethyldivinylsiloxane) 3:

<img file="PL220596B1_D0001.tif" />

wherein Me is methyl.

The Karstedt complex is prepared by combining (contacting) 1,3-divinyl tetramethyldisiloxane with chloroplatinic acid (H2PtCl6) in the presence of NaHCO3 and a hydroalcoholic solvent (isopropanol).

This known catalyst and its preparation are described in US Patent No. 3,775,452.

The very high catalytic activity of this type of catalyst, even at room temperature, is a significant disadvantage for its use in EVC polyadditions, as elastomer crosslinking begins shortly after all components have been combined.

Another disadvantage of this catalyst is related to the possible instability of the catalyst during the reaction: precipitation of metallic platinum and the formation of insoluble colloids in the reaction medium have been observed: this instability of the catalyst in the reaction medium reduces the catalytic activity. In addition, it causes random discoloration of the products, which is not particularly appreciated by users.

Another significant disadvantage of the Karstedt catalyst is the simultaneous formation of hydrosilylation reaction by-products: products resulting from the isomerization of the olefinic double bond and / or the hydrogenation reaction separate together with the hydrosilylation products.

In unpublished patent application FR 99/15432 of 12/07/1999, metallic complexes useful as hydrosilylation catalysts are disclosed having the formula:

<img file="PL220596B1_D0002.tif" />

wherein:

R3 is hydrogen; (C1-C8) alkyl; or (C3-C8) cycloalkyl optionally substituted with (C1-C4) alkyl; T1 and T2 are identical and represent (C1-C8) alkyl or (C3-C8) cycloalkyl;

PL 220 596 B1

Rd and Re are identical and represent (C1-C8) alkyl or (C3-C8) cycloalkyl;

(preferably, T1 = T2 = Rd = Re = methyl).

Such metallic Pt / carbene complexes are obtained by a two-step process, illustrated by the example below:

1. Carbene production:

CH,

<img file="PL220596B1_D0003.tif" />

2. Preparation of a platinum complex with the formula:

Hj

<img file="PL220596B1_D0004.tif" />

CH, vol ³_N zi: C ch₃

According to this unpublished prior patent application, catalysts are used to catalyze the reaction of a compound containing an ethylenic double bond or an acetylene triple bond (unsaturated compound) with a compound containing at least one Si-H moiety such that a C-Si bond is formed. Examples of compounds containing an ethylene double bond include ethylene, propylene, 1-butylene, 1-pentene, 2-methyl-1-butene, 1-hexene, 1-heptene,

1-octene, 3-ethyl-1-hexene, 1-decene, 4,4-dimethyl-1-nonene, vinylcyclohexene, styrene and 2-vinylnaphthalene.

Examples of compounds containing an acetylene triple bond include: ethynyl,

2-propynyl, 1-propynyl and 2-penten-4-ynyl.

Examples of compounds having at least one Si — H moiety are polymethylhydrogensiloxane, polydimethylsiloxane having a -SiH end group, methylhydrogen dimethylsiloxane copolymers, methylhydromethyloctylsiloxane copolymers, and methylhydrogen cyclosiloxane polymers.

U.S. Patent No. 5,728,839 also discloses metal / carbene complexes prepared in two steps from imidazolium, benzimidazolium, triazolium, tetrazolium or pyrazolium (e.g. iodide) salts. Such metallic (rhodium) complexes with heterocyclic carbenes are described as being optionally useful as catalysts for the hydrogenation or hydroformylation of unsaturated organic compounds such as olefins. This US patent is not concerned with the cross-linking of silicones.

It would now be convenient to have, in the art, crosslinkable silicones available, especially for elastomers of catalysts which are active at elevated temperature and which show little or no activity at room temperature. This could create the possibility of formulating one-component silicones which are cross-linkable at elevated temperature and stable when stored for long periods at room temperature (long shelf life). One-component silicone compositions are those which contain in one mixture all the reactive components (POS Si-vinyl / POS Si-H) and a catalyst. Typically, cross-linking inhibitors are used to increase the pot life of one-component silicone compositions. Thus, in the case of the Karstedt catalyst, the use of an inhibitor is essential and allows the room temperature stability of the POS Si-vinyl / POS Si-H composition to be extended, e.g. from 1 minute to 24 hours. However, this is an expensive solution with limited quality efficacy as the use of large amounts of inhibitor can destroy the structure of the elastomer during crosslinking.

In view of this prior art, one of the main objectives of the invention is to propose a hydrosilylating crosslinkable silicone composition containing one or more heterocyclic carbene-based metal complexes as a catalyst, which catalyst has a low activity at room temperature so that it allows produces 4

Non-one-component compositions containing a catalyst and compounds capable of reacting at elevated temperatures by hydrosilylating unsaturated components (e.g. POS SiH / POS Si-alkenyl), while remaining stable at room temperature for a long period of time (e.g. from 1 day) up to several months).

Another primary object of the invention is to propose a hydrosilylating crosslinkable silicone composition containing one or more heterocyclic carbene-based metal complexes as a catalyst, in which crosslinking does not involve isomerization side reactions or produces a color that can interfere with the hydrosilylation.

Yet another fundamental object of the invention is to propose new metallic complexes based on heterocyclic carbene that can be used as hydrophilylation catalysts, the catalysts being stable in the reaction medium so as to reduce the formation of:

❖ undesirable by-products resulting from olefinic double bond isomerization and / or hydrogenation reactions, ❖ and / or by-products which cause a color change that is difficult to accept.

Another basic object of the invention is to propose new metallic complexes based on heterocyclic carbene that can be used as hydrosilylation catalysts, which catalysts must have selective catalytic activity with a high qualitative and quantitative level in the reaction medium.

Another basic object of the invention is to propose new metallic complexes based on heterocyclic carbene that can be used as hydrosilylation catalysts, the catalysts having to be very active at elevated temperature and have little or no activity at room temperature so that they can be used as hydrosilylation catalysts. formulate in one-component silicone compositions, which are cross-linkable at elevated temperature and are stable when stored for long periods at room temperature (long pot life), and achieve this with little or no cross-linking inhibitor.

Another fundamental object is to propose a hydrosilylation process, in particular for the hydrosilylation of ethylenically and / or acetylenically unsaturated compounds in the presence of a catalyst containing the above-mentioned new metal complexes.

The invention achieves, inter alia, the above objectives.

The invention relates to a hydrosilylating crosslinkable silicone composition comprising at least one polyorganosiloxane -A- (POS) containing ethylenic and / or acetylenic unsaturation (s), at least one polyorganosiloxane -B-, a metal catalyst -C- and optionally at least one inhibitor -D- of a hydrosilylation reaction, characterized in that the composition comprises a -C- catalyst selected from the products of formula (I):

L,

M *

-γ where:

• M represents platinum in oxidation state 0;

• Ly is the carben of formula (II):

<img file="PL220596B1_D0005.tif" />

PL 220 596 B1 in which:

- A and B independently represent C or N with the proviso that when A is N then T₄ absent, and when B is N, T3 is absent;

&gt; T.₃ and T.₄ represent a hydrogen atom or form together a phenyl,&gt; and T.₁ and T.₂which may be the same or different are (C.₁-C₈) alkyl or (C.₃-C₈) cycloalkyl, preferably selected from the group of substituents consisting of: methyl, n-propyl, n-pentyl, neopentyl (-CH2-C (CH3) 3), cyclopentyl, cyclohexyl, adamantyl, allyl (-CH2-CH = CH2), metallyl (-CH₂-C (CH₃) = CH₂), propargil, homopropargil (- (CH₂)₂-C CH), or

- (CH1) - C = C — C (CH1).

²γ-1-3 ³³ or —R "-c = c — Si (cn₃⁾3 y - 1 - j or alternatively: group - (CH₂)_Y=_1-4-amine, especially N (CH₃)₂; or - (CH₂)_Y= i_₄-alkoxy, especially O (CH₃)₂;

&gt; and / or A and B are both carbon atoms, • L, and L_p are ligands which may be the same or different and each means:

z ................ = ................. Z (ULI) or

<img file="PL220596B1_D0006.tif" />

(ΙΠ.2) where, in these formulas (III.i) and (III.2):

WITH^and, WITH², WITH³, WITH⁴, WITH⁵, WITH⁶ are selected from the group consisting of or together form an L5 ligand of formula (IV):

-COOCH3, -COOCH2CH3, -CONCi2H25

<img file="PL220596B1_D0007.tif" />

wherein:

and2. Y and Y are, independently of each other, SiR_cR_d;

❖ X is O;

i0 ii i3 i4 ❖ Rⁱ⁰, Rⁱⁱ, Rⁱ³ and rⁱ⁴which may be the same or different are selected from hydrogen, alkyl and aryl optionally substituted with alkyl;

i2 ❖ R⁹, Rⁱ², Rc and Rd are independently selected from the group consisting of hydrogen; alkyl; acyl; aryl optionally substituted with alkyl; cycloalkyl optionally substituted with alkyl; and arylalkyl in which the aryl portion is optionally substituted with alkyl;

PL 220 596 B1 ❖ when Y₁ and Y₂ independently represent SiR_cR_d, two groups of R._c attached to two different silicon atoms together form a chain of formula:

<img file="PL220596B1_D0008.tif" />

where n is an integer of 1-3; X is O and R and R ', which may be the same or different, have any of the meanings given above for Rc, provided that in the case n is 2 or 3, only one silicon atom in that chain may be substituted with one or two alkenyl or alkynyl; or alternatively when Y1 and Y2 are independently SiRcRd, two Rc groups attached to different silicon atoms together form a saturated hydrocarbon chain, two Rc groups together with the silicon atoms and X form a 6-10 membered ring;

and where the term "alkyl" denotes a linear or branched, saturated hydrocarbon chain with 1-10 carbon atoms;

The "alkyl portion" of the alkoxy is as defined above; the term "cycloalkyl" denotes a mono- or polycyclic, preferably mono- or bicyclic, saturated hydrocarbon group containing 3-10 carbon atoms;

the term "polycyclic saturated hydrocarbon group" means a group containing two or more cyclic rings connected together by δ [sigma] bonds and / or fused in pairs, especially polycyclic cycloalkyls include adamantane and norbornane, and monocyclic cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl;

the term "perfluoroalkyl" means an alkyl containing at least one perfluoroalkyl group, having the formula:

-(^CH2) p-Cq^F.2q + 1 wherein p is 0, 1, 2, 3 or 4; q is an integer from 1-10; and CqF2q + 1 is linear or branched, especially: - (CH2) 2- (CF2) 5-CF3 and - (CF2) 7-CF3;

the term "aryl" denotes a monocyclic or polycyclic, preferably monocyclic or bicyclic, aromatic hydrocarbon group containing 6-18 carbon atoms; preferably in the context of the invention, the term "polycyclic aromatic group" denotes a group containing two or more aromatic rings which are fused together, ie have at least two common carbon atoms in pairs;

the term "arylalkyl" means alkyl as defined above, substituted with one or more aryls in the hydrocarbon chain, aryl being as defined above, especially benzyl and triphenylmethyl;

the term "acyl" means the group R ° -CO-, wherein R ° is alkyl as defined above; or the group Ar-CO- in which Ar is aryl as defined above, or alternatively arylalkyl in which aryl and alkyl are as defined above and in which the aryl portion is optionally substituted, especially with alkyl;

the term "alkenyl" denotes a linear or branched, substituted or unsubstituted, unsaturated hydrocarbon chain containing at least one olefinic double bond, alkenyl having 2-8 carbon atoms; said hydrocarbon chain optionally contains at least one O, N or S heteroatom, especially alkenyl is allyl and homoallyl;

the term "alkynyl" means a linear or branched, substituted or unsubstituted, unsaturated hydrocarbon chain containing at least one acetylenic triple bond, alkynyl having 2-8 carbon atoms, especially acetylenyl and propargyl; said hydrocarbon chain optionally contains at least one O, N or S heteroatom;

the term "absent" means that the substituents -T3 or -T4, respectively, are absent.

11 13 14

Preferably in composition R.¹⁰, R¹¹, R¹³ and r¹⁴ are hydrogen atoms.

12

Preferably in composition R.⁹ and r¹² are hydrogen; alkyl; aryl optionally substituted with alkyl; or cycloalkyl optionally substituted with alkyl.

PL 220 596 B1

In the composition, preferably R.⁹ = R.¹²; R¹⁰ = R.¹³; R¹¹ = R.¹⁴ and Y¹ = SiRcRd and Y² = SiRcR_dwith two Rc together forming a symmetrical chain.

Preferably in the composition, the catalyst -C- has the following formula (I.1):

<img file="PL220596B1_D0009.tif" />

<img file="PL220596B1_D0010.tif" />

<img file="PL220596B1_D0011.tif" />

Ν: Ć

Ν /

<img file="PL220596B1_D0012.tif" />

wherein:

T1 and T2 are identical and represent (C1-C8) alkyl or (C3-C8) cycloalkyl;

T3, T4, A and B are as defined above;

Rc and Rd are defined above.

Preferably in the composition, the catalyst -C- is selected from the metallic complexes of the formula (I.2) below:

<img file="PL220596B1_D0013.tif" />

wherein:

T1 and T2 are identical and are defined in claim 1;

T3, T4, A and B are as defined above;

Z3 to Z6 are as defined above.

In the composition, the catalyst -C- is preferably selected from the metal complexes of the formula (I.3) below:

<img file="PL220596B1_D0014.tif" />

wherein:

T1 and T2 are identical and are defined above;

T3, T4, A and B are as defined above;

Z1 and Z2 are defined above.

The composition is preferably characterized in that POS -A- and -B- are selected from siloxyl containing compounds of the general formula:

(R²⁰) xSiO4_x / 2 (I ')

PL 220 596 B1 and / or siloxy moieties of the formula:

(R²¹) y (R²²) zSiO4-yz / 2 (II ') where in these formulas different symbols have the following meanings:

22

- each of the symbols R and R, which may be the same or different, represents a non-hydrolysable hydrocarbon group, which group may be:

* alkyl or haloalkyl containing 1-5 carbon atoms and containing 1-6 chlorine and / or fluorine atoms, * cycloalkyl and halogenocycloalkyl containing 3-8 carbon atoms and containing 1-4 chlorine and / or fluorine atoms, * aryl, alkylaryl and haloaryl containing 6-8 carbon atoms and containing 1-4 chlorine and / or fluorine atoms, * cyanoalkyl containing 3 or 4 carbon atoms;

- each of the symbols R.²¹which may be the same or different is hydrogen, C2-C6alkenyl, hydroxy, a hydrolyzable atom, or a hydrolyzable group;

- x is an integer equal to 0, 1, 2 or 3;

- y is an integer equal to 0, 1, 2 or 3;

- z is an integer equal to 0, 1 or 2;

- the sum of y + z is between 1 and 3;

with the proviso that POS -A-Si-alkenyl contains at least one R moiety²¹ = alkenyl in the molecule and POS -B-Si-H contains at least one R moiety²¹ = a hydrogen atom in the molecule;

advantageously

R²⁰ = methyl; ethyl; propyl; isopropyl; butyl; isobutyl; n-pentyl; t-butyl; chloromethyl; dichloromethyl;

a-chloroethyl; α, β-dichloroethyl; fluoromethyl; difluoromethyl; α, β-difluoroethyl; 3,3,3-trifluoropropyl; trifluorocyclopropyl; 4,4,4-trifluorobutyl; 3,3,4,4,5,5-hexafluoropentyl; β-cyanoethyl; γ-cyanopropyl; phenyl; p-chlorophenyl; m-chlorophenyl; 3,5-dichlorophenyl; trichlorophenyl; tetrachlorophenyl; o-, p-, or m-tolyl; a, a, a-trifluorotolyl; xylls such as 2,3-dimethylphenyl, 3,4-dimethylphenyl, more preferably methyl or phenyl, which groups are optionally halogenated, or alternatively cyanoalkyl;

R²¹ = hydrogen or vinyl.

Preferably in the composition, the cross-linking inhibitors are selected from:

- polyorganosiloxanes which are suitably cyclic, substituted with at least one alkenyl, with tetramethylvinyltetrasiloxane being particularly preferred,

- unsaturated amides,

- alkyl, alkenyl or alkynyl maleates, with diallyl maleate being particularly preferred

- acetylene alcohols,

- alkyl, alkenyl or alkynyl acetylenedicarboxylates,

- and their connections.

Preferably the composition comprises at least one crosslinking inhibitor -D- and at least one catalyst -C- as defined above, wherein at least one of the substituents Z1 to Z6, preferably each of them, in the -C- catalyst contains (s) at least one electron withdrawing group.

The composition is preferably free of the crosslinking inhibitor -D-, and contains the catalyst -C- as defined above, wherein the substituents Z1 to Z6 in the -C- catalyst are free of electron withdrawing groups.

The invention also relates to a metal complex of formula (I):

<img file="PL220596B1_D0015.tif" />

wherein • M represents platinum in oxidation state 0;

• Lγ is a carbene of formula (II):

PL 220 596 B1

<img file="PL220596B1_D0016.tif" />

wherein:

- A and B independently represent C or N with the proviso that when A is N then T₄ absent, and when B is N, T3 is absent;

&gt; T.₃ and T.₄ represent a hydrogen atom or form together a phenyl,&gt; and T.₁ and T.₂which may be the same or different are (C.₁-C₈) alkyl or (C.₃-C₈) cycloalkyl, preferably selected from the group of substituents consisting of: methyl, n-propyl, n-pentyl, neopentyl (-CH2-C (CH3) 3), cyclopentyl, cyclohexyl, adamantyl, allyl (-CH2-CH = CH2), metallyl (-CH₂-C (CH₃) = CH₂), propargil, homopropargil (- (CH₂)₂-C CH), or -C = C1-3

373 or ™_C.=_C.1-3

Si (CH₃)

373 or alternatively: the group - (CH₂)_Y=_1-4-amine, especially N (CH₃)₂; or - (CH₂)_Y= i_-4-alkoxy, especially O (CH₃)₂;

&gt; and / or A and B are both carbon atoms, • L, and L_p are ligands which may be the same or different and each means:

<img file="PL220596B1_D0017.tif" />

(ΠΙ.1) or

<img file="PL220596B1_D0018.tif" />

(ΠΙ2) where, in these formulas (III.i) and (III.2):

WITH⁵, WITH⁶ are selected from the group consisting of:

WITH^and, WITH², WITH³, WITH⁴

COOCH3, -COOCH2CH3, -CONCi2H25.

The metal complex preferably has the formula (I):

<img file="PL220596B1_D0019.tif" />

wherein:

Ti and T2 are identical and are defined above in complex definition; T3, T4, A and B are defined above in determining the complex;

Z3 to Z6 are defined above in complex definition.

PL 220 596 B1

The metal complex preferably has the formula (I):

<img file="PL220596B1_D0020.tif" />

wherein:

T1 and T2 are identical and are defined above in complex definition;

T3, T4, A and B are defined above in determining the complex;

Z1 and Z2 are defined above in complex definition.

The invention also relates to the use of a metal complex as defined above for the hydrosilylation of olefinic or acetylenic derivatives, in a composition as defined above, preferably containing at least one -D- inhibitor.

The invention therefore relates firstly to a silicone composition which is crosslinkable by hydrosilylation of at least one polyorganosiloxane -A- (POS) containing one or more ethylenic and / or acetylenic unsaturated groups with at least one polyorganosiloxane -B- in the presence of a metal catalyst -C- and optionally comprising at least one hydrosilylation reaction inhibitor -D-, characterized in that that the catalyst -C contains at least one compound selected from the products of formula (I):

<img file="PL220596B1_D0021.tif" />

wherein • M represents platinum in oxidation state 0;

• Ly is the carben of formula (II):

<img file="PL220596B1_D0022.tif" />

wherein:

- A and B independently represent C or N with the proviso that when A is N then T₄ absent, and when B is N, T3 is absent;

&gt; T.₃ and T.₄ represent a hydrogen atom or form together a phenyl,&gt; and T.₁ and T.₂which may be the same or different are (C.₁-C₈) alkyl or (C.₃-C₈) cycloalkyl, preferably selected from the group of substituents consisting of: methyl, n-propyl, n-pentyl, neopentyl (-CH2-C (CH3) 3), cyclopentyl, cyclohexyl, adamantyl, allyl (-CH2-CH = CH2), metallyl (-CH₂-C (CH₃) = CH₂), propargil, homopropargil (- (CH₂)₂-C CH), or

- (CH1) - C = C — C (CH A = 1-3 or

- (CH1) - C = C — Si (CHA = 1-3 ³³ or alternatively: - (CH2) y = 1-4-amino, especially N (CH3) 2;

PL 220 596 B1 or - (CH₂)_Y= i_₄-alkoxy, especially O (CH₃)₂;

&gt; and / or A and B are both carbon atoms, • L. and L_p are ligands which may be the same or different and each means:

WITH¹ = Z² (ULI) or

<img file="PL220596B1_D0023.tif" />

(ΠΙ.2) where, in these formulas (III.i) and (III.2):

WITH^and, WITH², WITH³, WITH⁴, WITH⁵, WITH⁶ are selected from the group consisting of or together form an L5 ligand of formula (IV):

-COOCH3, -COOCH2CH3, -CONCi2H25

<img file="PL220596B1_D0024.tif" />

wherein:

❖ Y₁ and Y₂ represent, independently of each other, SiR_cR_d;

❖ X stands for O:

11 13 14 ❖ R¹⁰, R¹¹, R¹³ and r¹⁴which may be the same or different are selected from hydrogen, alkyl and aryl optionally substituted with alkyl;

12 ❖ R⁹, R¹², Rc and Rd are independently selected from the group consisting of hydrogen; alkyl; acyl; aryl optionally substituted with alkyl; cycloalkyl optionally substituted with alkyl; and arylalkyl in which the aryl portion is optionally substituted with alkyl;

R Rc and Rd are independently selected from the group consisting of alkyl; aryl optionally substituted with alkyl; cycloalkyl optionally substituted with alkyl; and arylalkyl in which the aryl portion is optionally substituted with alkyl; or alternatively ❖ when Y1 and Y2 are independently SiRcRd, two Rc groups attached to two different silicon atoms together form a chain of formula:

<img file="PL220596B1_D0025.tif" />

where n is an integer of 1-3; X is O and R and R ', which may be the same or different, have any of the meanings given above for Rc, provided that in the case n is 2 or 3, only one silicon atom in that chain may be substituted with one or two alkenyl or alkynyl; or alternatively when Y1 and Y2 independently represent SiRcRd, two Rc groups attached to different silicon atoms together form a saturated hydrocarbon chain, two Rc groups together with the silicon atoms and X form a 6-10 membered ring.

The presence of certain metal / heterocyclic carbene complexes in the compositions according to the invention gives them high stability in the ambient atmosphere under normal conditions of temperature, humidity and pressure. Such silicone compositions can be stored as one-component formulations, uncrosslinked, in an ambient atmosphere for long periods of time (e.g., from 1 to several months). This result is all the more favorable and surprising, as in the case of certain katas12

With metal / heterocyclic carbene lysers, cross-linking inhibitors can be dispensed with or, at best, used in a smaller amount, which is entirely advantageous for economic reasons and with regard to the negative impact on the cross-linking of the elastomer and its final quality.

This stability goes hand in hand with the ability / suitability of the compositions of the invention to cross-link at elevated temperatures (e.g. at 100 ° C and above) by hydrosilylation to high quality elastomers, especially high structural and mechanical quality. In addition, the reaction kinetics are satisfactory.

Moreover, no side isomerization reactions are observed, and very little undesirable color change is observed after cross-linking of the compositions according to the invention.

Such one-component silicone compositions with long shelf life at room temperature are very advantageous in that they are not overly expensive. This advantage is even more significant when they do not contain an inhibitor.

The definition of the metallic complexes of formula (I) as the -C- catalyst which is the principal component of the compositions according to the invention is elaborated on below in detail.

Group 8 metals represented by M in formula (I) include, for example, platinum. In practice, M represents a platinum atom in the oxidation state of 0.

The term "alkyl" denotes a linear or branched, saturated hydrocarbon chain, optionally substituted (e.g. with one or more alkyls), preferably with 1-10 carbon atoms, e.g. 1-8 carbon atoms, especially 1-7 carbon atoms .

Examples of alkyls include especially methyl, ethyl, isopropyl, n-propyl, t-butyl, isobutyl, n-butyl, n-pentyl, isoamyl and 1,1-dimethylpropyl. The alkyl part of the alkoxy is as defined above.

The term "cycloalkyl" denotes a mono- or polycyclic, preferably mono- or bicyclic, saturated hydrocarbon group, preferably containing 3-10 carbon atoms, especially 3-8 carbon atoms;

The expression "polycyclic saturated hydrocarbon group" denotes a group containing two or more cyclic rings linked together by δ bonds and / or fused in pairs. Examples of polycyclic cycloalkyls include adamantane and norbornane. Examples of monocyclic cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

The term "perfluoroalkyl" denotes an alkyl containing at least one perfluoroalkyl group, preferably of the formula:

-^(CH2) p-Cq^F.2q + 1 wherein p is 0, 1, 2, 3 or 4; q is an integer from 1-10; and CqF2q + 1 is linear or branched. Examples of such preferred groups are: - (CH2) 2- (CF2) 5-CF3- and - (CF2) 7-CF3.

The term "aryl" denotes a monocyclic or polycyclic, preferably monocyclic or bicyclic, aromatic hydrocarbon group containing 6-18 carbon atoms. It should be understood that, in the context as used herein, the term "polycyclic aromatic group" refers to a group containing two or more aromatic rings that are fused together (ortho-condensed or ortho- and periscondensed), i.e. contain at least in pairs at least common carbon atoms.

Such an aromatic hydrocarbon group ("aryl") is optionally substituted, e.g. with one or more C1-C3alkyl groups, with one or more halogenated hydrocarbyl groups (e.g. CF3), with one or more alkoxy groups (e.g. CH3O) or with one or more hydrocarbyl groups containing one or more ketone groups (e.g. CH3CO-).

Examples of aryls which may be mentioned are phenyl, naphthyl, anthryl and phenanthryl.

The term "aralkyl" means alkyl as defined above, substituted with one or more aryls on the hydrocarbon chain, aryl being as defined above. Examples of such groups include benzyl and triphenylmethyl.

The term "acyl" denotes the group R ° -CO-, wherein R ° is alkyl as defined above; or the group Ar-CO- in which Ar is aryl as defined above or alternatively arylalkyl in which aryl and alkyl are as defined above and wherein the aryl portion is optionally substituted, e.g. with alkyl.

The term "alkenyl" denotes a linear or branched substituted or unsubstituted unsaturated hydrocarbon chain containing at least one olefinic double bond, more preferably only one double bond. Alkenyl preferably has 2-8, especially 2-6 carbon atoms. This hydrocarbon chain optionally contains at least one heteroatom such as O, N or S.

Preferred examples of alkenyls are allyl and homoallyl.

According to the invention, the term "alkynyl" denotes a linear or branched, substituted or unsubstituted, unsaturated hydrocarbon chain containing at least one acetylenic triple bond, more preferably only one triple bond. Alkynyl preferably has 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms. Examples which may be mentioned are acetylenyl and propargyl. This hydrocarbon chain optionally contains at least one heteroatom such as O, N or S.

The phrase "absent" means that the substituents -T3 or -T4, respectively, are absent. More specifically, in formula (II), the nitrogen atom is trivalent so that when A or B is N, the nitrogen atom may not contain additional substituents.

Preferably, in the carbene ligands of formula (II):

&gt; T.₃ and T.₄ represent a hydrogen atom or form together a phenyl,&gt; and / or T₁ and T.₂which may be the same or different are (C.₁-C₈) alkyl or (C.₃-C₈) cycloalkyl, preferably from the group of substituents consisting of: methyl, n-propyl, n-pentyl, neopentyl (-CH2-C (CH3) 3), cyclopentyl, cyclohexyl, adamantyl, allyl (-CH2-CH = CH2), metallyl (- CH2-C (CH₃) = CH₂), propargil, homopropargil (- (CH₂)₂-C CH), or - (CH₂) —_ c = c — C (Cl₃)₃ or

-_(CH)___C.=_C.__{Si (CH} V γ = 1 - 3 ³³ or alternatively: the group - (CH₂)_y=_1-4-amine (e.g. N (CH)₃)₂); or - (CH₂)_Y= i_₄-alkoxy (e.g. O (CH₃)₂);

&gt; and / or A and B are carbon atoms.

According to one embodiment, the carbenes of formula (II) corresponding to the Ly ligand in the -C- catalyst may contain at least two fused rings such that at least 2 of Ti, T2, T3 and T4, located on two adjacent ring members, together form saturated or unsaturated hydrocarbon chain, preferably with 3-6 carbon atoms. The expression "saturated or unsaturated hydrocarbon chain" denotes a linear or branched hydrocarbon chain, optionally containing one or more unsaturated bonds of the olefinic double bond type or the acetylenic triple bond type.

When the carbenes (II) contain fused rings, they correspond to one of the following formulas, wherein (alk) is a saturated or unsaturated hydrocarbon chain:

<img file="PL220596B1_D0026.tif" />

Ligands L and L._p of the -C- catalyst of formula (I) in the composition of the invention may independently be alkynyl of formula (III.i) or alkenyl of formula (III.2), substituted by Z groups^and - WITH⁶ containing at least one electron withdrawing moiety active against π unsaturation in L, and L_p, which ensures the binding of the ligand to the metal of the M complex.

In formulas (III.1) and (III.2), the electron withdrawing moieties may be selected from the group consisting of:

ABOUT

II c-or₁₇ about

c-no₁₈r₁₉ s

C-SR, p

C-OR₂₀ -C_n, F

PL 220 596 B1 where:

R17, R18, R19 and R20 are substituted or unsubstituted alkyl, alkenyl, alkynyl, or trialkylsilyl, and n 'is 1-50.

For example Z groups¹ - WITH⁶which can be replaced include:

❖ selected from the group consisting of: -COOCH3, -COOCH2CH3, CONC12H25, ❖ When Z¹ and Z² form, in pairs and with a triple bond, in (III.1), the ring Cy1 and when Z³ - WITH⁶ form in pairs, optionally with double bonds, in (III.2) a ring Cy2, such rings Cy1 and Cy2 are independently and preferably selected from the group consisting of the following rings:

<img file="PL220596B1_D0027.tif" />

When L. and L._p together they form an L5 ligand of formula (IV), this is a ligand of the type where Y₁ and Y₂ are CRaRb, where Ra and Rb are independently selected from the group consisting of hydrogen; alkyl; acyl; aryl optionally substituted with alkyl; cycloalkyl optionally substituted with alkyl; and arylalkyl in which the aryl portion is optionally substituted with alkyl;

or are preferably SiRcRd, such that the complexes have formula (IV.1) or formula (IV.2):

where

<img file="PL220596B1_D0028.tif" />

According to one variant, the two Rc in (IV.2) together form: (a) a string

R

AND

X ”(Si^_X) "

R 'where n is an integer of 1-3; X is as defined above; and R and R ', which may be the same or different, have any of the meanings given above for Rd, it being understood that when n is 2 or 3, only one silicon atom in that chain may be substituted with one or two alkenyl or alkynyl;

(b) or a saturated hydrocarbon chain such that the two Rc, together with the two silicon atoms they reside and X, form a 6-10 membered, preferably 6-8 membered ring.

When two Rc form chain (a) in (IV.2), n is preferably 1 or 2 (especially n is 1), and when R = Rd, the two Rd groups on the two silicon atoms are identical. In this case, Rd is preferably alkyl, e.g. methyl. More preferably in such compounds, R 'is

-CR₁₂= CR₁₃R₁₄ R₁₃ = R.₁₁; R₁₀ = R.₁₄; and R.₁₂ = R._9.

PL 220 596 B1

In this case, X is preferably O in (IV.2). Ligand L5 is then defined by the formula:

R¹⁰ R⁹ R¹² R¹³

R¹¹ Si R ^ Si R¹⁴ '\ I /' ^Rd O (SiO)_r„ ^Rd R^! (IY.2.2)

In these compounds, preferably the two Rd's are identical and are suitably alkyl (e.g., methyl).

Preferably, n is 1 or 2 and R = Rd, it being understood that when n is 2, only one silicon atom in the O- (SiRR'-O) n- chain may be substituted with one or two alkenyls or alkynyls. More preferably R '= -CR12 = CR13R14 and R13 = R11; R10 = R14; and R12 = R9.

When two Rc form, together with the two silicon atoms and the X group, a chain (b), preferably two R groups_c form an 8-membered ring. In such a case, preferably two R._d are identical. The L5 ligand is then defined by the formula:

<img file="PL220596B1_D0029.tif" />

where T is alkyl; and is an integer from 0-5 with T being located on one or more of ring members 1, 2, 3, 4 and 5 in the formula above.

Similarly, when Y1 and Y2 are CRaRb in (IV.1), the two Ra groups attached to different carbon atoms may together form a saturated hydrocarbon chain (c) such that the two Ra groups together with the carbon atoms on which they are located and X, form a 6-10 membered ring. Preferably, the ring formed is an 8-membered ring and the ligand L5 then has the formula:

<img file="PL220596B1_D0030.tif" />

The ligand L5 subgroups of the metallic complexes (catalyst -C-) which form part of the compositions according to the invention form complexes in which:

- X = O; Y1 and Y2 independently represent SiRcRd.

It is also disclosed that X can also stand for:

- X = NRe; Y1 and Y2 are independently CRaRb; or

- X = NRe; Y1 and Y2 are independently SiRcRd; or

Among these L5 ligands of formula (IV), preferred are those in which:

- when X is O, Y1 and Y2 independently represent SiRcRd.

When X is NRe, Y1 and Y2 may independently be CRaRb.

In practice, X stands for O and Y₁ and Y₂ independently represent SiR_cR_d in the L5 ligand of formula (IV).

As used herein, the phrase "independently represents" means that the specified substituents are identical or different.

PL 220 596 B1

For example, R.₁₀, R₁₁, R₁₃ and r₁₄ represent the hydrogen atoms in the L5 ligands of formula (IV).

- R9 and Ri2 are preferably a hydrogen atom; alkyl; aryl optionally substituted with alkyl; and cycloalkyl optionally substituted with alkyl. Of these preferred values, it is especially preferred that R9 and R11 which are identical represent a hydrogen atom; (C3-C8) cycloalkyl or (C1-C8) alkyl.

For example, the L5 diolefinic ligand of formula (IV) is symmetrical such that R₁₀ = R.₁₄; R11 = R13; R9 = R12 and the two groups Y1 and Y2 are either absolutely identical or Y1 = CRaRb and Y2 = CRaRa where the two Ra together form a symmetrical chain or alternatively Y1 = SiRcRd and Y2 = SiRcRd where the two Rc together form a symmetrical chain .

With regard to the catalyst -C- of the composition according to the invention, the first group of metal complexes of formula (I.1) that is particularly preferred is:

<img file="PL220596B1_D0031.tif" />

\

N: Ć

N /

<img file="PL220596B1_D0032.tif" />

where:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above.

A second particularly preferred group of -C-catalysts of the composition according to the invention are the metal complexes represented by the formula (I.2) below:

<img file="PL220596B1_D0033.tif" />

wherein:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above.

A third particularly preferred group of -C-catalysts of the compositions according to the invention are the metal complexes represented by the formula (I.3) below:

<img file="PL220596B1_D0034.tif" />

wherein:

T1 and T2 are identical and are defined above; T3 and T4 are as defined above;

PL 220 596 B1

Rc and Rd are defined above.

In addition to the -C- catalyst, the composition according to the invention comprises two polyaddition reactive polyorganosiloxane components, namely POS -A- and POS -B-. These components are selected from POSs containing siloxy groups of the general formula:

(R²⁰) xSiO4-x / 2 (I ') and / or siloxy groups of the formula:

(R²¹) y (R²²) zSiO4-yz / 2 (II ') where in these formulas different symbols have the following meanings:

22

- each of the symbols R.²⁰ and r²²which may be the same or different is a non-hydrolysable hydrocarbon group which may be:

* alkyl or haloalkyl containing 1-5 carbon atoms containing 1-6 chlorine and / or fluorine atoms, * cycloalkyl and halogenocycloalkyl containing 3-8 carbon atoms and 1-4 chlorine and / or fluorine atoms, * aryl, alkylaryl and haloaryl containing 6 - 8 carbon atoms and 1-4 chlorine and / or fluorine atoms, * cyanoalkyl having 3 or 4 carbon atoms;

- each of the symbols R.²¹which may be the same or different is hydrogen, C2-C6 alkenyl, hydroxy, a hydrolyzable atom or a hydrolyzable group;

- x is an integer equal to 0, 1.2 or 3;

- y is an integer equal to 0, 1, 2 or 3;

- z is an integer equal to 0, 1 or 2;

- the sum of y + z is 1-3;

with the proviso that POS -A-Si-alkenyl contains at least one R moiety²¹ = alkenyl in the molecule, and POS -B-Si-H contains at least one R moiety²¹ = a hydrogen atom in the molecule;

advantageously

R²⁰ = methyl; ethyl; propyl; isopropyl; butyl; isobutyl; n-pentyl; t-butyl; chloromethyl; dichloromethyl; a-chloroethyl; α, β-dichloroethyl; fluoromethyl; difluoromethyl; α, β-difluoroethyl; 3,3,3-trifluoropropyl; trifluorocyclopropyl; 4,4,4-trifluorobutyl; 3,3,4,4,5,5-hexafluoropentyl; β-cyanoethyl; γ-cyanopropyl; phenyl; p-chlorophenyl; m-chlorophenyl; 3,5-dichlorophenyl; trichlorophenyl; tetrachlorophenyl; o-, p-, or m-tolyl; a, a, a-trifluorotolyl; xylls such as 2,3-dimethylphenyl, 3,4-dimethylphenyl, more preferably methyl or phenyl, which groups are optionally halogenated, or alternatively cyanoalkyl;

R²¹ = hydrogen or vinyl.

These POSs, -A- and -B- are, for example, polyorganovinylsiloxane and polyorganohydrosiloxane, respectively. Various organic substituents for reactive vinyl groups and hydrogen atoms are, for example, methyl or cyclohexyl. Hydrogen atoms and vinyl groups are carried by siloxyl groups M = [R3SiO-] and / or D = [- (R) 2SiO-] and / or T = [- (R) SiO-]. Each of these hydrogen or vinyl containing M and D groups contains one or more H or vinyls, preferably only one.

The number of SiH or SiVi moieties in the molecule is greater than or equal to 1, preferably at least equal to 10, more preferably 10-100.

This may be 0.01-10% (preferably 0.1-2%) by weight. of vinyl groups in POS -A- and 0.001-5% (preferably 0.05-2%) by weight of hydrogen atoms in POS -B-.

Useful polymers include -Si (CH3) 3 end-group polymethylhydrosiloxane and -Si (CH3) 2H end group-containing polydimethylsiloxanes, -Si (CH3) 2H-end group methylhydimethylsiloxane copolymers, methylhydromethyloctylsiloxane copolymers, and cyclosylsiloxane polymers.

Generally, the average molecular weight of POS -A- and -B- that can be used in the reaction is 1x10²-1x10⁶ (g / mol)

In the case of POS -A-, this applies in particular to the dynamic viscosity ranges at 25 ° C:

O POS vulcanizable by polyaddition at elevated temperature (EVC), with a viscosity of 6 7 of bones equal to at least 1x10⁵ mPa.s, preferably from 1x10⁶ up to 1x10⁷ mPa.s, and more preferably

O POS vulcanizable by polyaddition at elevated temperature, of the liquid silicone elastomer (LSR) type, with a viscosity preferably from 1x10⁵ up to 5x10⁵ mPa.s.

According to a preferred embodiment of the invention, the silicone compositions are POS vulcanizable by polyaddition at elevated temperature (EVC), in which POS -A- may in practice have a viscosity of 25 ° C of e.g. 2x10⁶ mPa.s, and POS - B- from 10 - to 5000 mPa.s (e.g. 300 mPa.s).

PL 220 596 B1

In these examples, the viscosity is measured with a Brookfield viscometer in accordance with the AFNOR NFT 76 106 standard, May 1982.

All the viscosities given in the specification refer to the "Newtonian" dynamic viscosity at 25 ° C, ie the dynamic viscosity, which is measured in a known manner with a shear rate gradient that is low enough that the measured viscosity is independent of the rate gradient.

The composition according to the invention may also contain a number of conventional ingredients, in addition to POS -A- and -B- and the -C- catalyst, including in particular at least one crosslinking inhibitor -B- capable of arresting the polyaddition reaction and preserving the one-component ABCD composition. in an incompletely cross-linked state.

Accordingly, the invention relates to silicone compositions containing at least one -D- inhibitor, wherein the -C- catalyst is selected from metal complexes of formula (I.1) below:

<img file="PL220596B1_D0035.tif" />

• the following formula (I.2):

<img file="PL220596B1_D0036.tif" />

where:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above;

WITH¹ - WITH⁶ do not contain electron withdrawing moieties; • and / or of the following formula (I.3):

<img file="PL220596B1_D0037.tif" />

wherein:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above;

WITH¹ and Z² do not contain electron withdrawing moieties. These compositions are characterized by a long service life.

PL 220 596 B1

It will be appreciated that for certain -C- catalysts, especially those containing carbene (II) and at least one (and preferably two) La and Lp ligands of formula (III.1) or (III.2), no inhibitor is needed.

Accordingly, the invention also relates to silicone compositions not containing the -D- inhibitor, wherein the catalyst -C- is selected from the metal complexes:

•

<img file="PL220596B1_D0038.tif" />

wherein:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above;

at least one of Z¹ - WITH⁶ (each substituent preferably) contains at least one electron withdrawing moiety;

• and / or of the following formula (I.3):

<img file="PL220596B1_D0039.tif" />

d-3) in which:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above;

WITH¹ and Z² do not contain electron withdrawing moieties.

Such non-inhibitor compositions are characterized, quite advantageously and surprisingly, by a long pot life in an ambient atmosphere. Cross-linking only takes place at elevated temperatures. This advantage is of exceptional importance in terms of economy and in terms of ease of use and ease of storage.

Suitably the -D- inhibitors (if used) are selected from:

- polyorganosiloxanes which are preferably cyclic and substituted with at least one alkenyl, tetramethylvinyltetrasiloxane being particularly preferred,

- unsaturated amides,

- alkyl, alkenyl or alkynyl maleates, with diallyl maleate being particularly preferred,

- acetylene alcohols,

- alkyl, alkenyl or alkynyl acetylenedicarboxylates,

- and their connections

As regards acetylene alcohols (see FR-B-1528464 and FR-A-2372874), it should be mentioned that they are preferred thermal hydrosilylation blocking agents and have the formula:

R^x- (R ') C (OH) -C CH where in the formula:

PL 220 596 B1 • R^x is linear or branched alkyl or phenyl;

• R^y is H, linear or branched alkyl, or phenyl;

wherein the groups R.^x, R^y and the carbon atom located at the α position with respect to the triple bond, optionally forming a ring;

total number of carbon atoms in R.^x and r^y is at least 5, preferably 9-20.

Such alcohols are preferably selected from compounds with a boiling point above 250 ° C. Examples that may be mentioned include:

• 1-ethynyl-1-cyclohexanol;

• 3-methyl-1-dodecin-3-ol;

• 3,7,11-trimethyl-1-dodecin-3-ol;

• 1,1-diphenyl-2-propyn-1-ol;

• 3-ethyl-6-ethyl-1-nonyn-3-ol;

• 3-methyl-1-pentadecin-3-ol.

Such α acetylene alcohols are commercially available products.

Such retarding agent (D) is present in an amount of not more than 3000 ppm, preferably in an amount of 100-2000 ppm based on the total weight of the organopolysiloxanes (A) and (B).

Known groups of conventional functional additives that can be used in the silicone compositions according to the invention are:

• fillers, • hydroxylated POS oils, useful as miscibility agents, • adhesion promoters, • adhesion modulators, • pigments, • heat-resistant, oil-resistant or flame-resistant additives (e.g. metal oxides), • etc.

The fillers that may be considered are preferably mineral. They may be products selected from silica (or non-silica) materials.

The silica materials can act as a reinforcing or partially reinforcing filler.

Reinforcing silica fillers are selected from colloidal silicas, fumed colloidal silica powders, and precipitated silica powders or mixtures thereof.

Such powders generally have an average particle size of less than 0.1 µm and a BET specific surface area of ​​more than 50 µm²/ g, preferably 150-350 m²/ g.

Partially reinforcing silica fillers such as diatomaceous earths or ground quartz can also be used.

Non-silica mineral materials can act as a partially reinforcing mineral filler or as a weighting mineral filler.

Such non-silica fillers that may be used, alone or in admixture, include carbon black, titanium dioxide, alumina, hydrated alumina, expanded vermiculite, unexpanded vermiculite, calcium carbonate, zinc oxide, mica, talc, iron oxide, barium sulfate, and lime. put out.

Typically, such fillers have a particle size of 0.001-300 µm and a specific surface area of₂ wa BET below 100 m²/ g.

In practice, but not limited to, the filler used may be a mixture of quartz and silica.

The fillers can be treated with any suitable product.

The proportion by weight of fillers used is preferably 20-50%, more preferably 25-35% by weight, based on the components of the composition as a whole.

In general, the quantitative composition of the compositions according to the invention corresponds to those customary in the relevant technical field, given the intended use.

It is also disclosed that the complexes of formula (I) may be useful as -C- catalysts when composed of a carbene of formula (II) wherein:

- T.₃ and T.₄ they may form A and B together when each is carbon, aryl as defined above, preferably phenyl;

PL 220 596 B1

- and / or T1 and T2 independently represent a monovalent group of formula (V) V1 V2 (V) below wherein:

• V1 represents a divalent hydrocarbon group, preferably optionally substituted or branched C1-C10alkylene, • V2 represents a monovalent group selected from the following group of substituents:

♦ alkoxy, -OR^vwhere r^v is hydrogen, alkyl or aryl ♦ amino, preferably N (R^v)₂where r^v is hydrogen, alkyl or aryl

- or alternatively T1 and T2 independently represent a monovalent group of formula (W) as follows: —W1 — ω — W2 (W) wherein:

♦ W1 is a divalent hydrocarbon group, preferably optionally substituted or branched C1-C10alkylene, ♦ ω means: -R^andC = CR^andwhere r^and is H or alkyl or

-CC ♦ W2 represents a monovalent group selected from the following group of substituents:

♦ R^p = alkyl or H;

♦ Si-alkyl, Si-alkenyl or Si-alkynyl, preferably -Si (alkyl) 3;

♦ an alcohol moiety, preferably -C (R^E.)₂OH where R '= H or alkyl;

♦ a ketone moiety, preferably —C — R⁵11 Where R '' = alkyl; alkenyl, alkynyl;

♦ carboxyl, preferably - C-OR⁵

AND!

Where R '' = alkyl; alkenyl, alkynyl;

♦ an amide moiety, preferably

O —c ~ n (rP)₂ where r^p = H, alkyl; alkenyl, alkynyl;

♦ acyl, preferably —OCR⁵at

Where R '' = alkyl; alkenyl, alkynyl;

T1 and T2 are preferably independently a group W of the type

- (CH₂) C = C — C (CH₃)₃ or - (CII j — CE C — Si (CU₃)₃ or, alternatively, one of the following groups: methyl, isopropyl, t-butyl, n-pentyl, neopentyl, cyclopentyl, cyclohexyl, adamantyl, allyl, methallyl, propargyl or homopropargyl

PL 220 596 B1

- or alternatively T1, T2, T3 and T4 may form in pairs when they are on two adjacent ring members of formula (II), a saturated or unsaturated hydrocarbon chain.

The invention therefore also discloses new metallic complexes of formula (I) in which:

&gt; Ly is as defined above,&gt; La and Lp are independently compounds of formula, (III.1) or (III.2) as defined above.

Examples of such new catalysts that may be mentioned are:

• compounds of the following formula (I.2):

<img file="PL220596B1_D0040.tif" />

wherein:

T1 and T2 are identical and are defined above; T3 and T4 are as defined above;

Rc and Rd are defined above;

• or compounds of the formula (I.3) below:

<img file="PL220596B1_D0041.tif" />

wherein:

T1 and T2 are identical and are defined above;

T3 and T4 are as defined above;

Rc and Rd are defined above.

It should be emphasized that in these formulas (I.1), (I.2) and (I.3), platinum can be replaced by any metal M selected from the group 8 metals of the periodic table (Handbook of Chemistry and Physics, 65th edition, 1984-). 1985).

The invention also discloses any catalyst composition containing, as active ingredient, one or more metallic complexes (I) as defined above and containing at least one La ligand or Lp (and even more preferably two ligands) of formula (III.1) or (III. 2).

Such catalysts (especially hydrosilylation catalysts) have the special feature that they can be prepared in situ in silicone compositions of the composition according to the invention, provided that they contain La and Lp ligands of formula (III.1) or (III.2) ), e.g. as an -D- inhibitor. This ligand or the La and Lp ligands of formula (III.1) or (III.2) are capable of substituting the Lδ ligands of catalyst C-. Such catalysts are latent catalysts. The invention, of course, discloses such a case.

The invention also discloses a process for hydrosilylating olefins or acetylenic derivatives (e.g., hydrosilylating one or more POSs -A- with one or more POS -B-), characterized in that it comprises the use of a silicone composition as defined above and / or a composition. catalytic converter also described above.

According to one preferred variant, in which at least one latent catalyst as described above is used, the silicone composition according to the invention as described above and containing at least one -D- inhibitor is used, which allows the in situ formation of at least one metallic complex containing at least one La or Lp ligand of formula (III.1) or (III.2).

PL 220 596 B1

Surprisingly, when the hydrosilylation is carried out using the metal complexes prepared by the above method as catalysts, the formation of by-products is significantly limited. In particular, a strong reduction in the level of isomer formation is observed, as well as a reduction in color change associated with catalyst decomposition.

The hydrosilylation reaction can be performed with or without a solvent. In one embodiment, the reagents can act as a solvent: for example, a compound containing an ethylene double bond or an acetylene triple bond.

Suitable solvents include those that are miscible with the compound containing the Si — H moiety.

Under these hydrosilylation reaction conditions, the catalytic complex should be dissolved in the reaction medium.

Examples of solvents that can be used in the hydrosilylation are especially aliphatic hydrocarbons (such as pentane, hexane, heptane, pentamethylheptane or petroleum distillate fractions); aromatic hydrocarbons (such as benzene, toluene, and xylenes: o-xylene, p-xylene, and m-xylene); halogenated aliphatic or aromatic hydrocarbons (such as tetrachlorethylene); or ethers (such as tetrahydrofuran or dioxane).

The hydrosilylation reaction can be carried out at a temperature of 15-300 ° C, e.g. 20-240 ° C, more preferably 70-200 ° C, especially 50-150 ° C and very particularly preferably 100-100 ° C.

The relative amounts of the unsaturated compound and the Si — H containing compound can be adjusted to ensure that all unsaturated groups react with the Si — H bonds.

In general, the molar ratio of unsaturated groups to Si-H bonds is from 1: 100 to 10: 1.

According to the invention, the hydrosilylation reaction is carried out in the presence of a catalytic amount of one or more of the complexes of the invention. The term "catalytic amount" means an amount less than the mole equivalent of platinum relative to the amount of unsaturation present in the reaction medium.

Usually it is sufficient to introduce into the reaction medium less than 1000 ppm, preferably less than 100 ppm and most preferably less than 50 ppm of platinum, based on the total weight of the unsaturated compound and the Si-H-containing compound.

With respect to the preparation of the compositions according to the invention, the compounds -A-, -B-, -C- and optionally -D- and one or more other conventional additives are used and mixed together.

The mixing operation is well known to those skilled in the art.

POS -A- and -B-, inhibitors -D- and other common additives such as fillers are fully available commercial products or obtainable by those skilled in the art.

With respect to the metallic complexes (I) forming the -C- catalysts, it was found above that the -C- catalysts containing the complexes: (I)

<img file="PL220596B1_D0042.tif" />

with La and / or Lp, of formula (III.1) or (III.2), can be obtained from complexes (I) in which Ly is given by formula (II) and La and Lp are given by formula (IV), wherein said ligands are substituted in situ by the -D- inhibitors of formula (III.1) or (III.2).

Such complexes (I) in which Ly is represented by the formula (II) and La and Lp are represented by the formula (IV) are prepared in the usual way, e.g. from known complexes by ligand exchange, e.g. by addition in a solution of the appropriate carbene of formula II with a metallic complex of metal M, referred to as the precursor complex.

Examples of suitable precursor complexes include the Karstedt complex of the formula:

Pt2 [ViMe2Si-O-SiMe2Vi] 3 wherein Vi is a vinyl group.

PL 220 596 B1

Complexes of formula I are usually prepared from precursor complexes containing, as a ligand, at least one diolefinic compound of formula (IV.P):

<img file="PL220596B1_D0043.tif" />

wherein R1, R2, R3, R4, R5, R6, X, Y1 and Y2 are defined above in formula I.

These ligands are commercially available or readily prepared by one skilled in the art from commercially available compounds.

Amine protecting groups P and suitable deprotection methods are described in Protective Groups in Organic Synthesis, Greene TW and Wuts PGM, published by John Wiley &amp; Sons, 1991, and in Protecting Groups, Kocienski PJ, 1994, Georg Thieme Verlag.

When X is O and Y is CRaRb, compounds of formula (IV) are ethers. Such ethers are commercially available or are prepared by known methods from commercially available compounds.

Compounds of formula IV in which X is O and Y1 and Y2 are SiRcRd are linear, branched or cyclic siloxanes which are commercially available or can be obtained from commercially available compounds by known methods. Examples of preferred siloxanes of formula IV include ViMe2SiOSiMe2Vi and (MeViSiO) 3, the second formula being cyclosiloxane, where VI is vinyl.

For symmetrical compounds of formula IV, i.e. where R 1 = R 6; R2 = R5; R3 = R4 and Y1 = Y2, one of the following synthesis variants may be used.

(Variant a): In preparing such symmetrical siloxanes of formula IV, wherein R1, R2, R3, Rc and Rd are independently selected from the group consisting of alkyl, aryl, alkenyl and alkynyl, a silyl chloride of formula Cl2SiRcRd may be reacted with an organometallic compound with the formula:

CR1 R2 = CR3-Mg-Hal where R1, R2 and R3 are as defined above and Hal is halogen under the usual reaction conditions where magnesium reagents are used.

(Variant b): In the preparation of such symmetrical siloxanes of formula IV where R1 = R2 = R3 = H and Rc and Rd are selected from alkenyl, alkynyl, aryl and alkyl, the silyl chloride of formula Cl2SiRc-CH = CH2 can be subjected to reaction with an organometallic compound of the formula:

Rd-Mg-hal wherein Rd is as defined above and hal is halogen.

To carry out this variant, one skilled in the art may refer to J. Gen.

Chem., USSR, 1977,47 1402-1406.

(Variant c): For the preparation of such symmetrical siloxanes of formula IV where R1 = R3 = H and R2 is alkyl and the siloxane of formula:

H-SiR_cR_d-O-SiR_cR_dH can be reacted with two equivalents of an acetylenic hydrocarbon of formula HC = C-R2 in which R2 is as defined above.

Cyclic siloxanes of formula IV are described in US Patent No. 4,593,084.

Carbenes of formula II can be prepared by deprotecting imidazolium salts, tetrazolium salts, triazolium salts or pyrazolium salts, as the case may be, by treatment with a base.

PL 220 596 B1

These reactions can be schematically presented as follows:

<img file="PL220596B1_D0044.tif" />

VHT.l χ rule _&gt; &gt;

<img file="PL220596B1_D0045.tif" />

ILI

In this reaction scheme, T1, T2, T3, T4, A and B are defined above in formula I, and Xrepresents an anion.

The nature of the anion X^- it is not critical to the viewpoint of the invention. Anion X^- is an anion derived from a mineral or organic Bronsted acid (protic acid). Typically the anion X^- is derived from an acid with a pKa of less than 6. Preferably, X^- is derived from an acid with a pKa of less than 4, more preferably less than 2. The pKa values ​​in this case are the pKa values ​​of the acids measured in water.

Examples of acids include carboxylic acids of formula Go-COOH where Go is alkyl, e.g., (C1-C22) alkyl or aryl, e.g. (C6-C18) aryl optionally substituted with one or more alkyls, preferably one or more (C1-C6) alkyl; sulfonic acids of formula GoSO3H in which Go is as defined above; and phosphonic acids of formula GoPO3H in which Go is as defined above; other acids include HF, HCl, HBr, HI, H2SO4, H3PO4, and HCIO4.

Preferred examples of carboxylic acids are acetic acid, benzoic acid, and stearic acid. The preferred sulfonic acids that can be mentioned are benzenesulfonic acid and the preferred phosphonic acids that can be mentioned are phenylphosphonic acid.

According to the invention, the anions of X^- derived from the acids HF, HCl, HBr, HI, H2SO4, HBF4 and H3PO4 are particularly preferred.

In this connection, the particularly preferred anions of X^- according to the invention, include halide, sulfate, bisulfate, phosphate, hydrogen phosphate and dihydrogen phosphate anions. Anions which may also be mentioned are tetrafluoroborate and hexaphenylphosphate.

Bases that can be used to deprotonate the salts of formula VIII include strong bases selected from alkali metal hydrides, alkali metal hydroxides, alkali metal carboxylates, alkali metal alkoxides, and alkali metal amides.

Accordingly, examples of suitable bases include sodium hydride, sodium methoxide, potassium t-butoxide, and lithium diisopropylamide, and mixtures thereof.

The deprotection reaction is preferably performed in a solvent capable of at least partially dissolving the starting salt of formula VIII and the other reagents.

The nature of the solvent also depends on the strength of the base, in particular, in the case of strong base and particularly reactive starting salts, it may be necessary to carry out the reaction at low temperature.

Typically the reaction temperature is from 40 to -78 ° C, preferably from 30 to -50 ° C, even more preferably from 25 to -40 ° C, e.g. from 20 to -30 ° C.

Solvents that can be used in the preparation of carbene include cyclic or non-cyclic ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dimethoxyethane, or diethylene glycol dimethyl ether.

Other solvents that can be used include dimethylsulfoxide, dimethylformamide, dimethylacetamide, hexamethylphosphorylamide: [(CH3) 2N] 3PO, and hexamethylphosphoramide

[(CH3) 2N] 3P.

Carbenes of formula II where A and B are carbon can also be prepared by reduction of the corresponding thiones of formula IX:

PL 220 596 B1

<img file="PL220596B1_D0046.tif" />

This reaction is described by N. Kuhn in Synthesis, 1993, 561. Preferably, the reaction is carried out in an ether or amide type solvent as defined above at a temperature of 50-150 ° C in the presence of potassium.

The starting salts of formula VIII alone can be obtained by reacting the appropriate imidazoles, pyrazoles, triazoles and tetrazoles with the appropriate acid.

The nature of the anion X^- in the salts of formula VIII depends on the acid used in this step. The acids that can be used are, for example, those mentioned above from which X is derived^-.

Another method for synthesizing the salt of formula VIII where A = B = C is described in US Patent No. 5,077,414.

The method involves reacting the α-dicarbonyl compound X of the formula:

<img file="PL220596B1_D0047.tif" />

wherein T3 and T4 are as defined above, with HCHO and two amines of the formulas T1-NH2 and T2-NH2, in the presence of the corresponding acid.

Other methods for the preparation of the salts of formula VIII have been proposed in Chem. Eur. J. 1996, 2, No. 12, pp. 1627-1636 and Angew. Chem. Int. Ed. Engl. 1997, 36, 2162-2187.

Compounds of formula IX can be prepared by condensation of the corresponding thiourea of ​​formula XI:

s li

1 \ HN — C — NHT₂ xi with an α-hydroxy ketone of formula XII:

HO O '&gt;!

CH-C xii

T, T.

4 wherein T1, T2, T3 and T4 are as defined above. He described suitable reaction conditions in particular

N. Kuhn in Synthesis, 1993, 561.

According to one particularly preferred embodiment of the invention, the metal complex according to

<img file="PL220596B1_D0048.tif" />

wherein the L corresponding to Lγ is as defined above.

A simple method of preparing this complex involves reacting the L-carbene with a Karstedt catalyst of average formula Pt2 [ViMe2Si-O-SiMe2Vi] 3, where Vi is vinyl.

This reaction can be carried out in bulk or in a solvent.

PL 220 596 B1

Examples of suitable solvents include cyclic or non-cyclic ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dimethoxyethane, or diethylene glycol dimethyl ether; amides such as dimethylformamide or dimethylacetamide; and aromatic hydrocarbons (such as toluene or xylenes, especially toluene).

Conveniently, the reaction is carried out in ether, preferably in tetrahydrofuran.

The reaction temperature is usually 10-50 ° C, preferably 15-35 ° C, more preferably 20-25 ° C.

The reaction is conveniently carried out in the presence of a slight excess of carbene over platinum. Thus, the molar ratio of L-carbene to platinum is typically from i to i, 3, preferably from i to i, i.

A simple way to carry out the reaction is to pour, at a suitable temperature, a solution of the carbene in a solvent into a reactor containing a solution of Karstedt's catalyst in the same solvent.

According to the invention, the molar concentration of the carbene solutions and the catalyst solution is not of great importance.

According to one variant, the method comprises a combination of the following ingredients:

• at least one salt of formula (VIII):

<img file="PL220596B1_D0049.tif" />

* z '&lt;vnn where:

- A, B, T₁, T₂, T₃ and T.₄ are defined above;

- WITH₇ independently is an anion derived from a Bronsted acid (protic acid) preferably selected from the group consisting of:

- carboxylic acids of formula Go-COOH in which Go is alkyl, suitably C1-C22 alkyl; aryl, suitably C6-C18 aryl optionally substituted with one or more C1-C6 alkyl;

- sulfonic acids of formula Go-SO3H in which Go is as defined above;

- phosphoric acids of formula Go-PO3H in which Go is as defined above;

- the following mineral acids: HF, HCl, HBr, HI, H2SO4 H3PO4, HCIO4 and HBF4, used singly or in combination;

- and mixtures thereof;

• at least one precursor complex of formula (IVp) selected from the group consisting of the corresponding Karstedt precursor complexes (IVp) of formula:

Pt2 [ViMe2Si-O-SiMe2Vi] 3 wherein Vi is vinyl;

• at least one solvent (V);

• and at least one principle (VI).

Conveniently, solvent V is selected such that the solubility of salt (VIII) and base (VI) in said solvent (V) is at least 1 wt.%. at 25 ° C.

The solvent (V) is selected from polar aprotic solvents with a boiling point at 1 atm pressure below 150 ° C, preferably 120 ° C, preferably from the group consisting of:

• cyclic or non-cyclic ethers, in particular tetrahydrofuran (THF), diethyl ether, dioxane diisopropyl ether, dimethoxyethane or diethylene glycol dimethyl ether;

• dimethylformamide, dimethylacetamide, hexamethylphosphorylamide: [(CH3) 2N] 3PO and hexamethylphosphoramide [(CH3) 2N] 3P;

With THF being particularly preferred.

The base (s) (VI) is selected from strong bases capable of deprotonating the salts (VIII), preferably from the group consisting of:

alkali metal hydrides, alkali metal hydroxides, alkali metal carboxylates, alkali metal alkoxides and alkali metal amides, even more preferably from the group consisting of:

sodium hydride, sodium methoxide, potassium t-butoxide, and lithium diisopropylamide, and mixtures thereof. The concentration of the base (VI) in the reaction medium, in moles / liter of solvent (V), is preferably:

10^-6 &lt;VI &lt;1, even more preferably 10^-3 &lt;VI &lt;10^-1.

Salt (VIII) and base (VI) are used in such amounts that the ratio RVI / VIII of the normal concentrations VI / VIII is determined by the following relationships:

^RVI / VIII ^{&lt; 1} • preferably 1 &amp; lt; RVVI / VIII &amp; lt; 5; • more preferably 1 &amp; lt; RVVI / VIII &amp; lt; 3

In summary, the process is essentially the following:

a) dissolve salt (VIII) and compound (IVp) in the solvent (V),

b) introduce the base (VI) in several portions to the solution (VIII) and (IVp) in (V),

c) the reaction medium obtained is stirred, preferably in the dark, until the compound (I) is formed,

d) recovering compound (I) formed, preferably by evaporation,

e) purification is optionally carried out,

f) optionally drying.

Preferably, at least one of steps a), b) and c), even more preferably all three are performed at a temperature of 5-50 ° C, preferably at room temperature.

Preferably, it is used:

• at least one salt (VIII) of the formula:

<img file="PL220596B1_D0050.tif" />

wherein:

- T.₁ and T.₂ are identical and represent (C.₁-C₈) alkyl or (C.₃-C₈) cycloalkyl;

- T.₃ and T.₄ they are identical and represent a hydrogen atom or together represent phenyl;

- Z1 is a halogen atom, preferably Cl or I or BF4;

at least one Karstedt complex as defined in U.S. Patent No. 3,775,452, preferably a compound of formula (IVp):

<img file="PL220596B1_D0051.tif" />

(VI)

PL 220 596 B1 in which:

Rd and Re are identical and represent CH3;

• solvent (V) being THF;

• and at least one base (VI) potassium t-butoxide (KOt-Bu).

The catalysts thus obtained can be used in hydrosilylation reactions. They ensure homogeneous catalysis of the reaction.

They also make it possible to obtain one-component silicone compositions, preferably for polyaddition of the EVC type, with a much longer pot life than compositions obtained with conventional platinum-based catalysts, with little or no -D- inhibitors.

The following examples illustrate the invention.

Examples

Example 1

- Preparation of carbene of formula:

<img file="PL220596B1_D0052.tif" />

(see Chem. Eur. J. 1996, 2, 1627).

In this reaction, the entire glass apparatus was dried overnight in an oven at 150 ° C and then cooled under argon.

THF was distilled from sodium / benzophenone just prior to use.

A 100 mL three-necked flask was charged with 2.70 g (10 mmol) of 1,3-dicyclohexylimidazolinium chloride, purged with argon and slurried in 20 mL of THF. About 50 mL of ammonia was condensed in a -78 ° C three-necked flask, which caused the salt to partially dissolve. The acetone / dry ice bath was removed and 270 mg of 95% NaH (10.7 mmol, 1.07 eq.) Was slowly added via a powder funnel. There was a significant evolution of gas (H 2) with each addition of NaH and the salt in the suspension gradually dissolved. The reaction mixture was stirred for 1 hour 30 minutes at the reflux temperature of the solvent. The ammonia was then evaporated to give a pale yellow solution with a suspended solid (NaCl). This solution, containing 0.5 M carbene in THF, was used immediately for the preparation of the complexes.

- Preparation of platinum complex of formula (catalyst C1):

<img file="PL220596B1_D0053.tif" />

Karstedt's solution containing 10 wt. platinum (i.e., 1.52 mmol of platinum) was obtained as described in U.S. Patent No. 3,775,452.

3.2 ml of a 0.5 M carbene solution of the formula:

PL 220 596 B1

<img file="PL220596B1_D0054.tif" />

3 g of this solution were added dropwise from a dropping funnel in tetrahydrofuran, while stirring and diluted in 10 ml of tetrahydrofuran. The instillation was complete after 10 minutes. The reaction mixture was then stirred for 50 minutes at room temperature. When necessary, a small amount of insoluble material was filtered off and the reaction mixture was concentrated in vacuo.

After concentration, a pale yellow sticky residue was obtained. A profuse white precipitate of divinyl tetramethyldisiloxane precipitated out of the residue within a few hours. The solid was filtered off and washed with a few ml of hexamethyldisiloxane and then with pentane. 570 mg (60% yield) of analytically pure white powder were obtained.

Part of this powder was recrystallized from a mixture of dichloromethane / absolute ethanol. The obtained crystals were analyzed by X-ray diffraction. The analysis confirmed the structure of the obtained complex.

Example 2

- Preparation of carbene of formula:

<img file="PL220596B1_D0055.tif" />

This carbene was prepared as described in Example 1, Part 1, except that 2.7 g (10 mmol) of 1,3-dicyclohexylimidazolinium chloride were replaced with 2.3 g (10 mmol) of 1,3-dimethylimidazolinium iodide.

- Preparation of platinum complex of formula C2:

<img file="PL220596B1_D0056.tif" />

CH, ι ³N — ι zi ^:ę I

N "J

CH,

This complex was prepared by the method of Example 1, except that the starting material was carbene of formula:

CH,

AND ³N -: C

N— i

CH

PL 220 596 B1

After concentration, a yellow paste was obtained. This paste was drained and washed thoroughly with hot pentane. An off-white solid (35% yield) isolated which was recrystallized from ethanol. The obtained crystals were analyzed by X-ray diffraction. The analysis confirmed the structure of the obtained complex.

Example 3: Preparation of a platinum complex of formula (III.2) (catalyst C3):

<img file="PL220596B1_D0057.tif" />

500 mg (0.815 mol) of the complex of Example 1 was placed in a 50 ml single necked round bottom flask equipped with a magnetic stirrer. The flask was purged with an argon stream. The complex was then dissolved in 25 mL of anhydrous THF, followed by injection of 116 µL (135 mg; 0.94 mmol; 5 eq.) Of dimethyl acetylenedicarboxylate. The reaction mixture was held at the reflux temperature of the solvent for 2 hours. After cooling to room temperature, THF was evaporated in vacuo. The resulting solid was dissolved in a minimum amount of dichloromethane. The crude product is chromatographed on a silica column (eluent: 80/20 cyclohexane / ethyl acetate). After concentration in vacuo, the resulting yellow flakes were washed with 2-propanol and then filtered off with a suction pump. 350 mg (60% yield) of analytically pure yellow powder were obtained.

Example 4: Preparation of one-component silicone compositions containing POS -A- and -B- and catalysts -C1-, -C2- or -C3- from Examples 1, 2 and 3, respectively.

In order to obtain a homogeneous phase with the silicone medium, the catalysts -C1-, -C2- and -C3 from examples 1, 2 and 3 were introduced as a solution in toluene. A basic reaction system (M) was prepared by mixing 100 g of a polyorganovinylsiloxane containing 0.61 wt. % of vinyl groups 27 g of a polyorganohydrosiloxane containing 0.17 wt. hydrogen groups. In each example, platinum was added to the mixture (M) in an amount of 80 ppm by weight. Depending on the example, the nature of the catalyst and the inhibitor were changed (Tables 1 and 2 below). Karstedt's catalyst (platinum at oxidation state zero, dissolved in vinyl silicone oil) was used as a reference.

The following inhibitors were used:

<img file="PL220596B1_D0058.tif" />

Each system was assessed by DSC and by determining the gel time corresponding to the time the reaction mixture solidified to solid.

The results obtained are given in Tables 1 and 2 below.

PL 220 596 B1

Table 1

<td rowspan="2">Attempt</td><td rowspan="2">Catalyst</td><td rowspan="2">Inhibitor</td><td rowspan="2">[Inh] / [Pt]</td><td rowspan="2">Temp. start of reaction (° C)</td><td rowspan="2">Exotherm (° C)</td><td colspan="2">T gelling</td>

<td>room temp.</td><td>60 ° C</td>

<td> 1</td><td>C2</td><td> /</td><td> /</td><td> 70</td><td> 87</td><td>1 Day</td><td>(and)</td>

<td> 2</td><td>C1</td><td> /</td><td> /</td><td> 75</td><td> 111</td><td>1 Day</td><td>(ii)</td>

<td> 3</td><td>C2</td><td>I1</td><td> 60</td><td> 144</td><td> 148</td><td>40 days</td><td>36 h</td>

<td> 4</td><td>C2</td><td>I2</td><td> 60</td><td> 145</td><td> 147</td><td>40 days</td><td>36 h</td>

<td> 5</td><td>C1</td><td>I1</td><td> 60</td><td> 137</td><td> 149</td><td>40 days</td><td>36 h</td>

<td> 6</td><td>C1</td><td>I2</td><td> 60</td><td> 141</td><td> 149</td><td>40 days</td><td>36 h</td>

<td> 7</td><td>C1</td><td>I3</td><td> 60</td><td> 142</td><td> 149</td><td>&gt; 40 days</td><td>(ii)</td>

<td> 8</td><td>C3</td><td> /</td><td> /</td><td> 115</td><td> 130</td><td>&gt; 40 days</td><td>(ii)</td>

(i) the molar ratio of inhibitor to platinum (ii) not measured

Table 2

<td rowspan="2">Attempt comparative</td><td rowspan="2">Catalyst</td><td rowspan="2">Inhibitor</td><td rowspan="2">[Inh] / [Pt] (i)</td><td rowspan="2">Temp. start of reaction (° C)</td><td rowspan="2">Exotherm (° C)</td><td colspan="2">T gelling</td>

<td>RT</td><td>60 ° C</td>

<td> 1'</td><td>Karstedt</td><td> /</td><td> /</td><td></td><td>(ii)</td><td>qq min.</td><td>(iii)</td>

<td> 2'</td><td>Karstedt</td><td>I1</td><td> 60</td><td> 92</td><td> 96</td><td>5 days</td><td>5 hours</td>

<td> 3'</td><td>Karstedt</td><td>I2</td><td> 60</td><td> 99,5</td><td> 103,5</td><td>5 days</td><td>5 hours</td>

<td> 4'</td><td>Karstedt</td><td>I3</td><td> 60</td><td> 79</td><td> 84</td><td>1 Day</td><td>(ii)</td>

(i) mole ratio of inhibitor to platinum (ii) not measured (iii) not measurable due to too fast crosslinking of the system

Example 5: One-component EVC silicone composition according to the invention (all parts are by weight).

5.1: Manufacture

The following reagents were mixed for 2 hours at room temperature (23 ° C) in a Z-blade mixer:

• 88 parts of polyorganosiloxane, which was poly (dimethyl) (methylvinyl) siloxane blocked at each of the two ends with a trimethylsiloxy group, with 720 ppm in the chain of Vi groups, viscosity 5x10⁶ mPa ^ s at 25 ° C, • 12 parts of a polyorganosiloxane, which was a poly (dimethyl) siloxane blocked at each of the two ends with a dimethylvinylsiloxy group, containing 120 ppm of VI groups, viscosity 2x10⁶ mPa ^ s at 25 ° C, ₂ • 43 parts treated with D4 fumed silica with a specific surface area of ​​60 m2²/ g, • 2 parts of dimethylhydroxysiloxy end-blocked polydimethylsiloxane oil, viscosity 50 mPa · s at 25 ° C.

Per batch was added to the obtained composition:

• 2.82 parts of poly (dimethyl) (methylhydrogen) siloxane oil, blocked at each of its two ends with a dimethylhydrosiloxy group, containing 45,000 ppm of H groups, with a viscosity of 300 mPa ^ s at 25 ° C, • 3.75 ppm of metallic platinum introduced as platinum (0) complex, 225 ppm of SiH / SiVi addition reaction inhibitor, in the form of diallyl maleate.

5.2: Composition Testing: A part of the homogeneous mass obtained was used to measure the mechanical properties of the silicone elastomer obtained by hot vulcanization of the polyorganosiloxane composition. For this purpose, the part of the homogeneous mass retained for such tests was vulcanized for 10 minutes at 170 ° C in a suitable mold, so as to obtain 2 mm thick plaques.

PL 220 596 B1

Unannealed (NA) plates were obtained. Part of the plates was then subjected to annealing (or aging (A) for 4 hours at 200 ° C. Standardized samples were made from the plates as a whole and the following properties were measured:

• Shore A hardness (SAH) according to DIN 53505 • Breaking strength (BS) in MPa according to AFNOR NF T 4 6002 • Elongation at break (EB) in% according to the above standard • 100% modulus of elasticity (ME) in MPa, according to the above standard.

Another portion of the blender homogeneous mass was used to measure the changes in Williams plasticity of the unvulcanized silicone elastomer as a function of storage time and temperature.

5.3: Results • Mechanical properties The results are given in Table 3 below:

Table 3

<td></td><td>Property</td><td>Without preheating</td><td>4 hours / 200 ° C</td>

<td>Pt Karstedt, comparative example</td><td>SAH</td><td> 46</td><td> 56</td>

<td></td><td>BS (MPa)</td><td> 7,2</td><td> 8,0</td>

<td></td><td>EB (%)</td><td> 602</td><td> 522</td>

<td></td><td>100% ME (MPa)</td><td> 1,4</td><td> 1,8</td>

<td></td><td>Property</td><td>Without preheating</td><td>4 hours / 200 ° C</td>

<td>Catalyst of example 1: Pt / cyclohexylcarbene</td><td>SAH</td><td> 47</td><td> 58</td>

<td></td><td>BS (MPa)</td><td> 7,9</td><td> 8,7</td>

<td></td><td>EB (%)</td><td> 722</td><td> 542</td>

<td></td><td>100% ME (MPa)</td><td> 1,2</td><td> 1,8</td>

Comments:

The composition according to the invention gives an elastomer with mechanical properties slightly better than those of the known composition, without PT / cyclohexylcarbene catalyst but with Karstedt Pt.

Williams plasticity

The results are given in Table 4 below.

Table 4

<td rowspan="2">Pt Karstedt, comparative example</td><td>Property</td><td>25 ° C</td><td>50 ° C</td>

<td>Time (days)</td><td> 38</td><td> 2</td>

<td></td><td>% increase in consistency</td><td> 100</td><td> 100</td>

<td rowspan="2">Catalyst of example 1: Pt / cyclohexylcarbene</td><td>Property</td><td>25 ° C</td><td>50 ° C</td>

<td>Time (days)</td><td> 80</td><td> 8</td>

<td></td><td>% increase in consistency</td><td> 66</td><td> 100</td>

Comments:

The pot life of the compositions according to the invention is significantly longer than that achieved with a conventional composition, without PT / cyclohexylcarbene catalyst but with Karstedt Pt.