WO2010009754A1 - Curable silicone compositions comprising organo-silylphosphites - Google Patents

Abstract

The present invention relates to hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions comprising new phosphites, new transition metal compounds comprising phosphite ligands, cured products prepared from the hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions and new phosphites.

Description

CURABLE SILICONE COMPOSITONS COMPRISING ORGANO- SILYLPHOSPHITES

The present invention relates to hydrosilylation-curing polyorganosiloxane compo- sitions and/or silane compositions comprising phosphites, transition metal compounds comprising phosphite ligands, cured products prepared from the hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions and new phosphites. In particular, the invention is related to transition metal compounds comprising polycycloaliphatic phosphites and the use of those phosphites as inhibit- tors in hydrosilylation curing silicone compositons.

Platinum-(0)-vinylsiloxane complexes such as the divinyltetramethyl-disiloxane complex (Karstedt's catalyst) or tetravinyltetramethyl-cyclotetrasiloxane can catalyse the hydrosilylation reaction at very high reaction rates. Therefore these catalysts are currently used for crosslinking, curing or vulcanization of silicone rubber having alkenyl and SiH-groups by hydrosilylation between 20-200 ⁰C. However, this reaction at room temperature according to Arrhenius Law sometimes shortens the pot-life or bath-life time in an unacceptable manner (1 -10 min at 25 ⁰C).

It is well known from prior art disclosures that the high reaction rates of platinum catalysts can be slowed down by inhibitors, such as esters, e.g. maleates and fumarates, ketones, sulfoxides, phosphines, phosphites, nitrogen- or sulphur containing derivatives, hydroperoxides as well as acetylene derivatives such as alkinoles. If one describes the effect of such inhibitors in terms of Arrhenius Law one can observe in generally a shifted line in a diagram showing 1/k (k=reaction constant [s ¹] ) over 1/T (⁰K) as x-axis, i.e. if the pot-life is extended one can observe at the same time a decreased reaction rate at higher temperatures.

Some prior art documents attempt to decouple the effect of pot-life and cure rate at higher temperature. For example US 3,188,300 discloses specific aliphatic, cyclo- aliphatic and aromatic phosphites in order to anticipate premature gelling at 20 - 30 ⁰C. EP 948565 A1 discloses siloxane compositions comprising substituted and aromatic phosphites, which shows a different relation between cure rate at 140 ⁰C and pot-life at room temperature. US 2006/0135689 (Fehn) discloses siloxane compositions comprising olefin-nitrogen containing-ligand-platinum complexes which should have enlarged pot-life at room temperature and high reaction rates at higher temperatures.

US 2006/0128881 A1 and US 2004/0116561 A1 disclose hydrosilylation curing polyorganosiloxane compositions comprising phosphites but fail to discloses phosphites having trisorganosilyl or tris(triorganosiloxy)silyl groups. Moreover these documents are not concerned with the technical object of decouple the effect of pot- life and cure rate at higher temperature in hydrosilylation curing polyorganosiloxane compositions.

US 3,188,300 A1 and US 5,380,812 also disclose the use of phosphite inhibitors as inhibitors in hydrosilylation curing silicone compositions. Among the possible substituents there are also mentioned monocycloaliphatic groups, i.e. cyclohexyl. The present inventors have found however, that the use of tris(cyclohexyl)- phosphite reveals an unacceptable low curing rate at high temperatures, although the pot-life or storage stability, respectively, is acceptable.

Therefore, the present invention attempts to provide hydrosilylation curing polyorganosiloxane compositions, in particular, ^'One-Part^'-hydrosilylation curing polyorganosiloxane compositions that have a high pot-life, i.e. storage stability, and at the same time have high curing rates at high temperatures, which property is not affected upon long-term storage.

The present inventors have found that surprisingly phosphites having specific silyloxy substituents are suitable to solve these problems, if added to hydrosilylation curing polyorganosiloxane compositions. Accordingly the present invention is related to hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions, comprising one or more phosphites having the formula:

P(OSiRs)₃, (I),

wherein R is an organic group. Preferably the groups R are different or identical and are selected from the group of substituents, consisting of

- alkyl, preferably linear or branched alkyl with up to 8 carbon atoms, more preferably methyl, isopropyl, tert.-butyl; wherein alkyl may have one to three substituents selected from aryl, halogen, nitrile, amino, mono- or dialkylamino, alkylthio, mercapto and alkoxy, wherein the alkyl moiety in these substituents is as mentioned before; - alkoxy, preferably linear or branched alkoxy with up to 8 carbon, more preferably methoxy, isopropoxy, tert.-butoxy; wherein alkoxy may have one to three substituents selected from aryl, halogen, in particular, chloro or fluoro, nitrile, amino, mono- or dialkylamino, alkylthio, mercapto and alkoxy, wherein the alkyl moiety in these substituents is as mentioned before; aryl, preferably phenyl, wherein aryl may have one to three substituents selected from alkyl, aryl, halogen, nitrile, amino, mono- or dialkylamino, alkylthio, mercapto and alkoxy, wherein the alkyl moiety in these substituents is as mentioned before; - aryloxy, preferably phenoxy, wherein aryl may have one to three substituents selected from alkyl, aryl, halogen, nitrile, amino, mono- or dialkylamino, alkylthio, mercapto and alkoxy, wherein the alkyl moiety in these substituents is as mentioned before; and silyloxy, such as trialkylsilyloxy, triphenylsilyloxy, wherein the alkyl moiety is as mentioned before, a preferred silyloxy group is a trimethylsilyl group. In another alternative of the phosphites P(OSiRs )3 of formula (I) the three -OSiRs groups are linked together and form a three-dimensional siloxane cage structure, having preferably an alkyl group per silicon atom, which alkyl group may have 1 to 12 carbon atoms.

In the phosphites used according to the invention preferably all of the groups (OSiR₃) are the same.

Particularly preferred phosphites of the formula (I) are selected from the group, consisting of:

P(OSiRs)₃ (Ia),

wherein R is selected from an alkoxy and an aryloxy group, wherein alkoxy and aryloxy are as defined above, and preferably are selected from phenoxy and linear or branched alkoxy, preferably branched alkyl with 3 to 8 carbon atoms,

P(OSiRs)₃ (Ib),

wherein R is selected from an alkyl and an aryl group, and wherein alkyl and aryl are as defined above, and preferably are selected from phenyl and linear or branched alkyl with up to 8 carbons atoms, preferably branched alkyl with 3 to 8 carbon atoms,

P(OSiRs)₃ (Ic),

wherein R is selected from a silyloxy group, wherein a silyloxy is as defined before, preferably is a trimethylsiloxy group or a thphenylsilyloxy group, or the three -OSiR₃ groups are linked together and form a three-dimensional siloxane cage structure, as defined above. Examples of the preferred phosphites are selected from the group consisting of:

The inhibiting activity of the phosphites in the transition metal catalyzed hydro- silylation reaction is a consequence of the complex formation of the phosphites and the transition metal compound. Thus the present invention in a further aspect is also related to transition metal compounds, comprising at least one of the phosphites according to the invention. The transition metal in such transition metal compounds is preferably selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum, with platinum being the most preferred transition metal compound. Although it is possible to isolate transition metal compounds having those specific phosphite ligands of the invention, in the practice of hydrosilylation curing polyorganosiloxane systems, in general, certain common transition metal compounds are added together with the phosphites to the poly- organosiloxanes without separate formation of the transition metal phosphite complex compounds, or alternatively certain transition metal compounds are reacted with the phosphites so to say ^'in situ^', the reaction product being added to the hydrosilylation curing polyorganosiloxane systems. So from a technical point of view the isolation of the transition metal phosphite complex compounds has normally no importance and it suffices to determine the influence of the addition of the phosphites on the pot-life or storage stability and the curing rates at higher temperatures without identifying exactly the catalytical active transition metal species.

Nevertheless one can prepare and isolate on the other hand the underlying transition metal compounds of the phosphites of the invention by commonly known ligand exchange reactions. For example the well-known Karstedt catalyst can be reacted with the phosphites of the present invention to give the transition metal compounds in accordance with the present invention: The synthesis follows a pathway in that by example the well-known divinyl-tetramethyldisiloxane (^'DVTMDS^') -bridged binuclear platinum complex (Karstedt's catalyst) can be cleaved by any nucleophile (e.g. phosphite), giving a mononuclear platinum complexes, according to following equation:

CH₉ Pt ^• P(OSi R₃J₃

In another aspect of the present invention it relates to the use of one or more phosphites according to the invention for the manufacture of hydrosilylation-cuhng polyorganosiloxane and/or silane compositions, and in particular the use of one or more as inhibitors of the hydrosilylation reaction in the curing of polyorganosiloxane compositions and/or silane compositions. Furthermore the invention relates to hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions, comprising at least one or more of the phosphites according to the invention, the preferred ones given above.

The invention moreover relates to hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions, comprising:

(A) one or more polyorganosiloxanes and/or silanes having in average at least two alkenyl groups,

(B) one or more polyorganosiloxanes and/or silanes having in average at least two SiH groups,

(C) one or more transition metal compounds, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum,

(D) one or more of the phosphites as defined in formula (I), and

(E) optionally one or more auxiliary agents.

Component (A)

The inventive composition comprises one or more polyorganosiloxanes and/or silanes having in average at least two alkenyl groups (A) e.g. those disclosed in US 3,096,303, US 5,500,148 A (examples). Suitable compounds (A) can be described by the general formula (III),

[M_aD_bTcQd]m (III) wherein the formula (III) represents the ratios of the siloxy units M₁D₁T and Q, which can be distributed blockwise or randomly in the polymer chain. Within a polysiloxane chain each siloxane unit can be identical or different and preferably

a = 1 -10 b = 0 -12000 c = 0 - 50 d = 0 - 1 m = 1 - 5000.

These indices should represent the average polymerisation degree P_n based on the average number molecular mass M_n.

The polymer (A) is preferably selected from the group of alkenyl-containing polyorganosiloxanes, which can undergo hydrosilylation reactions with hydrogen siloxanes to form silicon carbon bonds.

The polymer (A) or mixtures thereof comprise groups selected from

T= RSiO₃Z₂, or T^*

Q=SiO_4/2j divalent R²-groups, wherein M^*= R¹pR_3-pSiOi/2, D^*= R¹ _qR2-qSiO₂/2, T^*= R¹SiO₃Z₂, wherein p= 1 -3, q= 1 -2.

R is preferably selected from n-, iso, or tertiary Ci-C3o-alkyl, alkoxyalkyl, C5-C30- cyclic alkyl, or C₆-C₃o-aryl, alkylaryl, which groups can be substituted by one or more O-, N-, S- or F-atom, e.g. ethers or amides or poly(C₂ -C₄)-alkylene ethers with up to 1000 alkylene oxy units.

Examples of said monovalent residues R in component (A) include hydrocarbon groups and halohydrocarbon groups. Examples of suitable monovalent hydrocarbon radicals include alkyl radicals, preferably such as CH₃-, CH₃CH₂-, (CH₃)₂CH-, CsHi₇- and CioH₂i-, cycloaliphatic radicals, such as cyclohexylethyl, aryl radicals, such as phenyl, tolyl, xylyl, aralkyl radicals, such as benzyl and 2-phenylethyl. Preferable monovalent halohydrocarbon radicals have the formula C_nF_2n+iCH₂CH₂- wherein n has a value of from 1 to 10, such as, for example, CF₃CH₂CH₂-, C₄F₉CH₂CH₂- , C₆Fi₃CH₂CH₂-,

C₂F₅-O(CF₂-CF₂-O)I-I₀CF₂-, F[CF(CF₃)-CF₂-O]i_-5-(CF₂)_0-2- C₃F₇-OCF(CF₃)- and C₃F₇-OCF(CF_S)-CF₂-OCF(CF₃)-.

Preferred groups for R are methyl, phenyl, 3,3,3-thfluoropropyl.

R¹ is selected from unsaturated groups, comprising C=C-group-containing groups (alkenyl groups), e.g.: n-, iso-, tertiary- or cyclic- C₂-C₃₀-alkenyl, C₆-C₃₀-cycloalkenyl, Cs-C_3O -alkenylaryl, cycloalkenylalkyl, vinyl, allyl, methallyl, 3-butenyl, 5-hexenyl, 7- octenyl, ethyliden-norbornyl, styryl, vinylphenylethyl, norbornenyl-ethyl, limonenyl, substituted by one or more O- or F-atoms, e.g. ethers, amides or C₂-C₄-polyethers with up to 1000 polyether units. The alkenyl radicals are preferable attached to terminal silicon atoms, the olefin function is at the end of the alkenyl group of the higher alkenyl radicals, because of the more ready availability of the alpha-, omega- dienes used to prepare the alkenylsiloxanes.

Preferred groups for R¹ are vinyl, 5-hexenyl.

R² includes for example divalent aliphatic or aromatic n-, iso-, tertiary- or cyclo- CrCi₄-alkylene, arylene or alkylenearyl groups which brigde siloxy units. Their content does not exceed 30 mol.% of all siloxy units. Preferred examples of suitable divalent hydrocarbon groups R² include any alkylene residue, preferably such as -CH₂-, -CH₂CH₂-, -CH₂(CH₃)CH-, -(CHz)₄-, -CH₂CH(CH₃)CH₂-, -(CHz)₆-, -(CHz)₈- and -(CH₂)i8-; cycloalkylene radical, such as cyclohexylene; arylene radicals, such as phenylene, xylene and combinations of hydrocarbon radicals, such as benzylene, i.e. -CH₂CH₂-CeH₄-CH₂CH₂-, -CeH₄CH₂-. Preferred groups are alpha, omega- ethylene, alpha, omega-hexylene or 1 ,4-phenylene.

Examples of suitable divalent halohydrocarbon radicals R² include any divalent hydrocarbon group wherein one or more hydrogen atoms have been replaced by halogen, such as fluorine, chlorine or bromine. Preferable divalent halohydrocarbon residues have the formula -CH₂CH₂(CF₂)i.i₀CH₂CH₂- such as for example,

-CH₂CH₂CF₂CF₂CH₂CH₂- or other examples of suitable divalent hydrocarbon ether radicals and halohydrocarbon ether radicals including -CH₂CH₂OCH₂CH₂-, -CeH₄-O- C₆H₄-, -CH₂CH₂CF₂OCF₂CH₂CH₂-,and -CH₂CH₂OCH₂CH₂CH₂-.

Such polymers containing R, R¹ and/or R² radicals are polyorganosiloxanes, e.g. alkenyl-dimethylsiloxy or trimethylsiloxy terminated polydimethylsiloxanes, which can contain other siloxane units than alkenylmethylsiloxy groups dimethylsiloxy groups such as poly-(dimethyl-co-diphenyl)siloxanes.

Broadly stated component (A) of the compositions of this invention can be any polyorganosilicone compound containing two or more silicon atoms linked by oxygen and/or divalent groups R² wherein the silicon is bonded to 0 to 3 monovalent groups per silicon atom, with the proviso that the organosilicon compound contains at least two silicon-bonded unsaturated hydrocarbon residues. This component can be a solid or a liquid, free flowing or gum-like i.e. it has measurable viscosity of less than 100 kPa.s at a shear rate of D=1 s^"1 at 25 ⁰C.

The siloxane units with radicals R and/or R¹ can be equal or different for each silicon atom. In a preferred version the structure is represented by the general formulas (Ilia) to (MIb), shown below. One preferred polyorganosiloxane component (A) for the composition of this invention is a substantially linear polyorganosiloxane (A) having the formula (Ilia) or (MIe) to (MIi). The expression "substantially linear" includes polyorganosiloxanes that contain not more than 0.2 mol.% (trace amounts) of siloxy units of the type T or Q. This means the polymer (A) is preferably a linear, flowable fluid or gum (A1 ) with a Newton like viscosity but not solid at 25 ⁰C.

R¹pR3-pSiO(R₂SiO)bSiR3-pRp¹ (MIa) (A1 )

R¹ _PR₃-p (R2SiO)bi(R¹qR₂-_q SiO)bix SiRs-pRp¹ (MIb) b = > 0 - 12000 b1 = > 0 -12000 b1 x = 0 -1000 b1 + b1x = > 0 - 12000 p= 0 to 3 q= 1 to 2,

with the proviso, that there are at least two alkenyl groups per molecule.

Preferred groups for R are methyl, phenyl, 3,3,3-trifluoropropyl Preferred groups for R¹ are vinyl, hex-5-enyl and cyclohexenyl-2-ethyl

The average polymerization degrees Pn or ^'b^' etc. is based on M_n as average number molecular mass in the range of up to 12000, the preferred range is 500 to 5000. The viscosity of such polymers is in the range of 10 to 100,000,000 mPa.s at 25 ⁰C at a shear rate of D= 1 s^"1, the preferred range is about 200 to 10,000,000 mPa.s. Such a viscosity at 25 ⁰C for the component (A) is suitable for the application of the manufacturing of broad variety of products such as molded or extruded shaped rubber parts with liquid silicone rubbers and high viscous rubbers, curable ^'Formed-in-Place^'- sealants well as coatings of substrates. In the group of alkenyl comprising siloxanes (A) the addition of other so-called vinyl rich polymers (A2) is preferred in order to modify mechanical properties.

The polymers (A2) are selected either from the group consisting of polymers of the formulas (1Mb) to (MId) or (MIh) to (MIi), i.e. linear polyorganosiloxanes having additional alkenyl side groups or branched polyorganosiloxanes having a higher concentration of T- and Q-groups than the previous types.

Me3SiO(Me2SiO)bi(MeViSiO)biχSiMe₃ (MIc) ,and

ViMe₂SiO(Me₂SiO)_bi(MeViSiO)_biχSiMe₂Vi (MId), whereby

Vi= vinyl.

The preferred value of b1x is less than 0.5 ^* b1 or zero. If b1x is not zero then it is preferably between 0.0003^*b1 to 0.25^*b1 preferably 0.0015^*b1 to 0.15^*b1.

Other preferred structures according of the formulas (MIe) to (MIi) achieve suitable viscosities as defined lateron and describe polymers applicable without any solvent for a viscosity adjustment. The range of subindices defines a range of the possible average polymerization degrees P_n.

Vi_PMe_3-PSiO(Me₂SiO)_Io_-I2OOo SiMe_3-PVi_P (III e) PhMeViSiO(Me₂SiO)io-i₂ooo SiPhMeVi (MI f),

VipMe_3-pSiO(Me₂SiO)io-i₂ooo (MeViSiO)i_-25oo SiMe_3-p Vi_p (III g),

Me₃SiO(Me₂SiO)io-i₂ooo (MeViSiO)i_-25ooSiMe₃ (III h),

PhMeViSiO(Me₂SiO)io-i₂ooo (MePhSiO)i-ioooSiPhMeVi (III i) and wherein Ph= phenyl, p= 0 to 3, preferred p=1.

In a preferred embodiment the polymer component (A) is a mixture of polymers of the formula (Ilia) and of the formula (IHb) whereby (MIb) has an alkenyl content of 1 to 50 mol.% in a ratio in that the alkenyl content of mixture of (A1 ) and (A2) is below 2 mol.% of all siloxy units of (A). Another class of preferred polymers are branched polyorganosiloxanes (A2) having a high concentration of SiMe_(3-P)(alkenyl)_p groups with distinct cure rates. Such structures are especially used in release coating applications. Branched polymers are dechbed e.g. in US 5,616,672 and are preferably selected from those of the formula (III) wherein the polyorganosiloxane (A2) comprising alkenyl groups has more than 0.2 mol.% of T=RSiO3/2 or Q=S iO₄/2-u nits.

Preferably the branched vinyl-rich polymers have a range of D : T > 10 : 1 preferably > 33 : 1 and/or respectively (M^alkenyl : Q) = 0.6 - 4 : 1.

All these polymers can be prepared by any of the conventional methods for pre- paring triorganosiloxane-terminated polydiorganosiloxanes. For example, a proper ratio of the appropriate hydrolyzable silanes, e.g., vinyldimethylchlorosilane and dimethyldichlorosilane, may be co-hydrolyzed and condensed or alternately an appropriate 1 ,3-divinyltetraorganodisiloxane, e.g., symmetrical divinyldimethyldi- phenylsiloxane or divinyltetramethylsiloxane, which furnishes the endgroups of the polydiorganosiloxane, may be equilibrated with an appropriate dipolyorganosilo- xane, e.g., octamethylcyclotetrasiloxane, in the presence of an acidic or basic catalyst. Regardless of the method of preparation of polydiorganosiloxane (A), there is usually coproduced a varying quantity of volatile, cyclic polydiorganosiloxanes.

The viscosities of the polydiorganosiloxanes (A) defined above for the purposes of this invention, refer preferably essentially free of cyclic polydiorganosiloxanes (less than 1 wt. %, preferably 0.5 wt.% measured for 1 h 150 ⁰C 20 mbar) portion of the polyorganosiloxane. This essentially cyclic free portion can be prepared by stripping the polydiorganosiloxane at 150 ⁰C for at least 1 hours to yield a polymer residue of this type. This residue will be essentially free of cyclic material with the exception of trace quantities of macrocyclic polydiorganosiloxanes (mol weight > 518 g/mol) which are non-volatile as defined above.

The average polymerization degree P_n of the polymer (A) measured by GPC measurement versus polystyrene standard based on the average number mol weight M_n is preferably in the range of > 10 to 12000, the more preferred range is 40 to 6000. The viscosities of such polymers are in the range of 10 to 50,000,000 mPa.s at 25 ⁰C at a shear rate of D=1 s^"1 . The value for P_n or the index ^'b^' in the above formula (Ilia) is such that the linear polyorganosiloxane (A) has a viscosity at 25 ⁰C, of at least 10 mPa.s. Preferably the range of the viscosity is from about 40 mPa.s to 35,000,000 mPa.s and, most preferably from 100 mPa.s to 25,000,000 mPa.s. Said viscosity corresponds approximately to the values of the average P_n, indicated by ^' b^' or ^'b1 +b1x^'.

The concentration of the functional unsaturated groups are in the range of 50 mol.% to 0.033 mol.% (mol-% of functionalized Si-atoms per total of Si-atoms), i.e. in case of polydimethylsiloxanes about preferably 0.002 to 12 mmol /g, more preferred 0.004 - 3 mmol/g.

Said siloxane units can be combined in any molecular arrangement such as linear, branched, cyclic and combinations thereof, to provide polyorganosiloxanes (A1 ) and (A2) that are useful as component (A). In a preferred embodiment the hydrosilylation-curable composition is solvent-less (less than 1 wt.-% volatiles).

The composition according to the invention is preferably used to coat a solid substrate, such as paper, fabrics or thermoplastic films with an adhesive-releasing layer or for extruding, calendering or molding shaped formed articles, laminates or for ^'Formed-ln-Place^'- sealing masses.

The alkenyl content of the components (A) can be determined here by way of ¹H NMR - see A.L. Smith (ed.): The Analytical Chemistry of Silicones, J. Wiley & Sons 1991 Vol. 112 pp. 356 et seq. in Chemical Analysis ed. by J. D. Winefordner.

The component (A) can be also selected of the group of silanes such as of the general formulae:

wherein R, R¹ is as defined above, R⁹ is as defined below, and e = 0 - 3 f = 1 - 4, and e + f = 4;

(R⁹O)_(3-g-h)(R¹ _g)(R_h)Si-R²-Si(R_h)(R¹ _g)(OR⁹)₍3_-h-g)> (R⁹ ₂N)_(3-g-h)(R¹ _g)(R_h)Si-R²-Si(R_h)(R¹ _g)(NR⁹ ₂)₍3_-h-g)j

wherein R, R¹ and R² is as defined above, R⁹ is as defined below, and

g = 1 -3, h = 0-2, and g + h = 3.

Component (B) - Crosslinker The curable compositions of the invention use a crosslinker and/or chain extender component (B) for the polymers defined under (A). The component (B) is from the group consisting of silanes, siloxanes having at least 2 SiH groups which can react with alkenyl groups of the polymers (A) and crosslink both polymers to an elastomeric network. In order to get a more elastomehc behaviour rather than a gel it is preferred that at least 30 mol.-% of the component (A) or (B) should have a functionality of reactive groups of 3 or more (number of Si-alkenyl groups per total of Si atoms for (A) and number of SiH-groups per total of Si atoms for (B)).

The component (B) is preferably selected from the group of SiH-containing polyorganosiloxanes and SiH-containing organosilanes respectively hydrogen silyl modified hydrocarbons. Suitably component (B) is composed of siloxane units selected from the groups M= R₃SiOi/₂, M^H=RYSiOi_/2, D=R₂SiO₂Z₂, D^H=RYSiO_2/2, T=RSiO₃/₂, T^H=YSiO_3/2, SiO_4/2, wherein R is as defined above and Y = R¹ and/or H, with the proviso that there are in average at least two SiH-groups per molecule. For example, they include:

ReHfSi(OR )(4-e-f)

ReH_fSi(NR⁹ ₂)_(4-e-f) wherein R is as defined above, R⁹ is as defined below, and e = 0 - 3 f = 1 - 4, and e + f = 4.

Further

(R⁹O)₍3_-g-h)(H_g)(R_h)Si-R²-Si(R_h)(H_g)(OR⁹)₍3_-h-g)> (R⁹ ₂N)₍3_-g-h)(H_g)(R_h)Si-R²-Si(R_h)(H_g)(NR⁹ ₂)₍3_-h-g)j

wherein g, h, R, R², R⁹ is as defined above or below.

This means the polymer (B) can be formally described by the ratios of the general formula (II),

wherein the siloxy units M, D, T and Q are as defined above including the possible SiH-containing M, D, T groups. Also possible is that part of the siloxy groups are alkenyl siloxy groups, as long as there are at least in average two SiH-groups per molecule. The siloxy units can be distributed blockwise or randomly in the polymer chain. Within a polysiloxane chain each siloxane unit can be identical or different and preferably a2 = 1 -10 b2 = 0-1000 c2 = 0-50 d2 = 0-1 m = 1 -2000

The afore mentioned indices should represent the average polymerisation degree P_n based on the average number molecular mass M_n.

The range for M-, D- ,T- and Q-units present in the molecule can cover nearly all values representing fluids, flowable polymer, liquid and solid resins. It is preferred to use liquid silanes or liquid linear, cyclic or branched siloxanes comprising optionally remaining d-C₃-alkoxy or Si-hydroxy groups remaining from the synthesis. These compounds can have a low molecular weight or are condensation products, which can be partially hydrolysed, as well as siloxanes polymerized via an equilibration or condensation under the assistance of acidic catalysts.

The siloxane units with radicals R or Y can be equal or different for each silicon atom.

The preferred structures of reactive polyorganosiloxanes for component (B) in the compositions of this invention are silanes or condensed silanes/siloxanes of formula (IVa) to (IVd).

The preferred structure composed with these units are selected from

Y_r R3-rSiO(R₂SiO)_z(RYSiO)vSiR3-rYr (IVa)

Y_rMe₃-r SiO(Me2SiO)_z(MeYSiO)vSiMe₃-r Yr (IVb)

Me₃SiO(MeYSiO)VSiMe₃ (IVc) [YRSiO]w (IVd) z = 0 to 1000 v = 0 to 100

z+v = 1 to 1000 w= 3 to 9 r= 0 or 1 , and structures of the formula

{[YSiO₃/2 ] [R⁹Oi/2] n2} m2 (IVe)

{[SiO_4/2}] [R⁹Oi_/2]n2 [R₂YSiOiZ₂ ] o,oi-io [YSiO_3/2 ]o-so [RYSiO_2/2 ] 0-1000 }_m2 (IVf)

wherein R⁹Oi/2 is an alkoxy residue at the silicon atom

n2= 0.001 to 3 a2 = 0.01 - 10 b2 = 0-1000 c2 = 0- 50 m2 = 1 to 2000

Y= hydrogen or R¹

R⁹ is hydrogen, n-, iso-, tertiary- or cyclo- C1-C25 alkyl, such as methyl, ethyl, propyl, alkanoyl, such acyl, aryl, -N=CHR, such as butanonoxime, alkenyl, such as propenyl, which groups R⁹ may be substituted by one or more halogen atoms, pseudohalogen groups, like cyano.

The preferred groups for Y are hydrogen.

One preferred embodiment of the compounds of class (IVe) and (IVf) is provided by way of example by monomeric to polymeric compounds which can be described via the formula [(Me2HSiOo 5)kSiO₄/2]m2 wherein index k can have integer or decimal values from 0.01 to (2^*m₂+2). Such liquid or resinous molecules can contain significant concentrations of SiOH- and/or (Ci-C6)-alkoxy-Si groups up to 10 mol.% related to the silicon atoms. Th e indices z and v for the other types of preferred compounds with the formulas (IVa) to (IVc) are in the range of 0-1000 defined as average P_n based on the number average mol mass M_n measured by GPC versus a polystyrene standard.

Other examples of preferred suitable compounds for component (B) in the compositions of this invention include HMe2SiO(Me2SiO)_zSiMe2H, Me₃SiO- (MeHSiO)v-SiMe_3j (MeHSiO)_3-6, Si(OSiMe₂H)₄, MeSi(OSiMe₂H)₃. HMe₂SiO- (Me₂SiO)_zi(MePhSiO)_z2(MeHSiO)_vSiMe₂H, wherein z1 +z2 = z.

The component (B) can be used as a single component of one polyorganosiloxane polymer or mixtures thereof. In a preferred alternative mixtures of formula (IVb) and (IVc) are used. If the increase of the cure rate is required, it is preferred to use some organopolysiloxanes (B) having HMe₂SiO_0,5- units to adjust the cure rate to shorter times.

The molecular weight of component (B) is smaller, the functionality in (B) per molecule is higher compared to component (A).

If it is necessary to still further increase the cure rate, this can be achieved by way of example via an increase of the molar ratio of SiH to Si-alkenyl, or an increased amount of catalyst (C), or an increase in the proportion of polyorganosiloxanes (B) which contain HMe₂SiO_{0 S} units. Thus preferred components (B) include HMe₂SiOo 5 (MH groups), in order to provide faster curing rates.

In a further preferred embodiment, of the component (B) this component is selected from the group according to formula (IVa) which consist of a component (B1 ) such as YR₂SiO(R₂SiO)_z(RYSiO)vSiR₂Y or formula (IVc) having a functionality of Y of 3 or more, and a component (B2) having a functionality of Y of 2 in average such as YR₂SiO(R₂SiO)_zSiR₂Y, wherein Y, R and z are as defined above. If (B1 ) and (B2) are used together, the preferred ratio of functionality SiH (B1 ) to (B2) is from more than 0 to 70 mol-%, and more preferably from 30 to 100 mol-% of (B2), based on (B1 ) and (B2).

The molweight for the component (B) is not critical; however it is preferred such that the polyorganosiloxane component (B) has a viscosity at 25 ⁰C up from 3 to 10,000 mPa.s in the case of R= methyl. The viscosity depends upon the kind of the R and Y substituents, and the ratio of the units M, D, T and Q as well as the molweight. For polyorganosiloxanes containing only methyl groups as R group the range of the molweights expressed as M_n is between 136 and 100,000 g/mol.

It is preferred to use liquid siloxanes with a low mol weight, i.e. smaller than 1 ,000,000 g/mol, preferably smaller than 75,000 g/mol in case of polydimethyl- methylhydrogensiloxanes.

The siloxane units with radicals R or Y can be equal or different for each silicon atom. Each molecule can bear one or more groups independently.

The crosslinker (B) should have at least more than 2 reactive groups Y per molecule whereas the chain extender (B2) have a functionality Y of 2 to 3 in average per molecule. The concentration of the reactive group Y is in the range of 0.2 to 100 mol.% Y groups related to Si atoms, i.e. for polydimethyl-methylhydrogensiloxane preferably about 0.1 -17 mmol SiY/g, the preferred range is 0.15 to 16 mmol/g. In one preferred embodiment a mixture of compounds having formula (IVc) or (IVd) are used together with (IVa) and/or (IVb), where z= 0, R= methyl and the SiH concentration is preferably >7-17 mmol SiH/g and in the second compound of (B) the index z > 0 wherein the SiH concentration has values of preferably 0.2 to 7 mmol SiH/g.

It is preferred to use compounds of formula (IVa) and/or (IVb) wherein R= aryl in particular phenyl, if adherence onto other substrates such as thermoplastic substrates has to be achieved. The SiH-content in the present invention is determined by way of ¹H-NMR, see A.L. Smith (ed.): The Analytical Chemistry of Silicones, J. Wiley & Sons 1991 Vol. 112 pp. 356 et seq. in Chemical Analysis ed. by J. D. Winefordner.

The ratio of the crossl inker (B) to polymer (A) necessary for getting an elastomeric network, i.e. a non-sticky surface can be calculated by the ratio of reactive groups in (B) and (A). It is preferred to have an excess of reactive groups (B) : (A) of 0.7 to 20 : 1 , preferably 1.2 to 6 : 1 , more preferably 1.5 to 4 : 1 in order to ensure a certain level of multifunctional structures in the cured elastomeric network.

Component (C) - Catalyst

The inventive composition contains at least one hydrosilylation catalyst as component (C) selected from the group of organo metal compounds, salts or metals, wherein the metal is selected from the group of Ni, Ir, Rh, Ru, Os, Pd and Pt com- pounds as taught in US 3,159,601 ; US 3,159,662; US 3,419,593; US 3,715,334; US 3,775,452 and US 3,814,730.

The component (C) for the hydrosilylation reaction of the inventive composition is a catalyst compound, which facilitates the reaction of the silicon-bonded hydrogen atoms of component (B) with the silicon-bonded olefinic hydrocarbon substituents of component (A). The metal or organo metal compound can be any platinum group metal-containing a catalytic active component. The catalyst (C) includes complexes with sigma- and pi-bonded carbon ligands as well as ligands with S-,N, or P atoms, metal colloids or salts of the afore mentioned metals. The catalyst can be present on a carrier such as silica gel or powdered charcoal, bearing the metal, or a compound or complex of that metal. Preferably, the metal of component (C) is any platinum complex compound.

A typical platinum containing catalyst component in the polyorganosiloxane compositions of this invention is any form of platinum (0), (II) or (IV) compounds which are able to form complexes with the inventive phosphites. Preferred complexes are Pt-⁽⁰⁾-alkenyl complexes, such alkenyl, cycloalkenyl, alkenylsiloxane such vinylsiloxane, because of its easy dispersibility in polyorganosiloxane systems. A particularly useful form of the platinum complexes are the Pt⁽⁰⁾-complexes with aliphatically unsaturated organosilicon compound such as 1 ,3-divinyltetramethyl- disiloxane (Vinyl-M2 or Karstedt catalyst), as disclosed by US 3,419,593 incorporated herein by reference are expecially preferred, cyclohexen-Pt, cyclooctadien- Pt and tetravinyltetramethyl-tetracyclosiloxane (Vinyl-D4).

Pt°-olefin complexes are prepared by way of example in the presence of 1 ,3-divinyl- tetramethyldisiloxane (M^V| ₂) via reduction of hexachloroplatinic acid or of other platinum chlorides by the way of example by alcohols in the presence of basic compounds such as alkali carbonates or hydroxides.

The amount of platinum-containing catalyst component that is used in the compositions of this invention is not narrowly limited as long as there is a sufficient amount to accelerate the hydrosilylation between (A) and (B) at the desired temperature in the required time (B) in the presence of all other ingredients of the inventive compo- sition. The exact necessary amount of said catalyst component will depend upon the particular catalyst, the amount of other inhibiting compounds and the SiH to olefin ratio and is not easily predictable. However, for platinum catalysts said amount can be as low as possible due to cost reasons. Preferably one should add more than one part by weight of platinum for every one million parts by weight of the organo- silicon components (A) and (B) to ensure curing in the presence of other undefined inhibiting traces. For the compositions of this invention, which are to be used by the coating method of this invention the amount of platinum containing catalyst component to be applied is preferably sufficient to provide from 1 to 200 ppm preferably 2 to 100 ppm, especially preferred 4 to 60 ppm by weight platinum per weight of poly- organosiloxane components (A) plus (B).

Preferably said amount is at least 4 ppm by weight per sum of (A) and (B).

The hydrosilylation catalyst can also be selected from the group of catalysts capable of being photoactivated. These photoactivatable catalysts preferably contain at least one metal selected from the group composed of Pt, Pd, Rh, Co, Ni, Ir or Ru. The catalysts capable of being photoactivated preferably comprises platinum.

Catalyst capable of being photoactivated is preferably selected among organometallic compounds, i.e., comprise carbon-containing ligands, or salts thereof. In a preferred embodiment photoactive catalyst (C) has metal carbon bonds, including sigma- and pi-bonds. Preferably the catalyst capable of being photoactivated (C) is an organometallic complex compound having at least one metal carbon sigma bond, still more preferably a platinum complex compound having preferably one or more sigma-bonded alkyl and/or aryl group, preferably alkyl group(s). Sigma-bonded ligands include in particular, sigma-bonded organic groups, preferably sigma-bonded Ci-C₆-alkyl, more preferably sigma-bonded methyl groups, sigma-bonded aryl groups, like phenyl, sigma-bonded silyl groups, like thalkyl silyl groups. Most preferred photoactivatable catalyst include η⁵-(optionally substituted)- cyclopentadienyl platinum complex compounds having sigma-bonded ligands, preferably sigma-bonded alkyl ligands.

Further catalysts capable of being photoactivated include (η-diolefin)-(sigma-aryl)- platinum complexes (see e.g. US 4,530,879). The catalyst capable of being photoactivated can be used as such or supported on a carrier.

The catalysts capable of being photoactivated is a catalyst, which provides additional options to extend the bath-life time of the reactive silicon based composition in addition to the inventive phosphites and allows to enlarge the processing time prior to gelling of the components.

Examples of catalysts capable of being photoactivated include η-diolefin-σ-aryl- platinum complexes, such as disclosed in US 4,530,879, EP 122008, EP 146307 (corresponding to US 4,510,094 and the prior art documents cited therein), or

US 2003/0199603, and also platinum compounds whose reactivity can be controlled by way for example using azodicarboxylic esters, as disclosed in US 4,640,939 or diketonates.

Platinum compounds capable of being photoactivated that can be used are moreover those selected from the group having ligands selected from diketones, e.g. benzoylacetones or acetylenedicarboxylic esters, and platinum catalysts embedded into photo-degradable organic resins. Other Pt catalysts are mentioned by way of example in US 3,715,334 or US 3,419,593, EP 1 672 031 A1 and Lewis,

Colborn, Grade, Bryant, Sumpter, and Scott in Organometallics, 1995, 14, 2202- 2213, all incorporated by reference here.

Catalysts capable of being photoactivated can also be formed in-situ in the silicone composition to be shaped, by using Pt°-olefin complexes and adding appropriate photo-activatable ligands thereto. The catalysts capable of being photoactivated that can be used here are, however, not restricted to these above mentioned examples.

The most preferred catalyst capable of being photoactivated to be used in the process of the invention are (η⁵-cyclopentadienyl)-trimethyl-platinum, (η⁵-cyclo- pentadienyl)-thphenyl-platinum complexes, in particular, (η⁵-methylcyclopenta- dienyl)-thmethyl-platinum.

The component (C) can also be selected from the group of reaction products of the platinum group metal-containing catalysts (C) and component (D) whereby each of the component is defined under (C) and (D).

The amount of the catalyst capable of being photoactivated is preferably 1 -500 ppm and preferably in the same lower range as defined for the heat-activatable hydro- silylation catalysts mentioned above.

As explained already above, the specific phosphites used in accordance with the invention interact with those conventional transition metal compounds through ligand exchange reactions, thereby influencing the hydrosilylation activity of the catalyst to provide surprisingly an excellent balance between storage stability on the one hand and reactivity at elevated temperatures upon curing.

Component (D): The inhibitor (D) is applied in a sufficient amount in order to further retard the hydrosilylation reaction at room temperature in order to enable mixing of the components (A) to (C) as well as the dispensing and coating step without prior curing.

On the other hand the cure rate after coating should be achieved in the shortest possible time after heat or light activation within seconds especially above 40 ⁰C.

With respect to the component (D) it can be referred to the phosphites having the formula:

P(OR)₃ (I)

as defined above.

The inhibitor compound (D) may be preferably incorporated therein in small amounts, such as less than 2 wt.% (20000 ppm) based on the total weight of (A) to (B).

A particularly preferred range is 0.2 to 12000 ppm of component (D) related to (A) and (B).

Furthermore preferably the molar ratio of the transition metal derived from component (C) platinum to the phosphite (D) is from 1 :1 to 1 :6. Due to their interaction with the transition metal hydrosilylation catalyst compound, the component (D) act as an inhibitor on the hydrosilylation reaction thereby increasing storage stability, and at the same do not exert their inhibiting activity during curing reaction.

As the case may be, it might be desirable to add additionally other conventional inhibitors, that is, to combine the inventive phosphites of component (D) with other conventional inhibitors in order to further modulate the hydrosilylation activity. In this case the preferred amounts for the component (D) included the amount of the other conventional inhibitors.

Thus, the inventive compositions may contain an appropriate amount of one or more additional conventional inhibitors. Preferably, however, the inventive compositions do not contain other phosphorous inhibitor compounds than those of formula (I).

Conventional inhibitors for the platinum group metal catalysts are well known in the organosilicon art. Examples of various classes of such metal catalyst inhibitors include unsaturated organic compounds such as ethylenically or aromatically unsaturated amides, US 4,337,332; acetylenic compounds, US 3,445,420 and US 4,347,346; ethylenically unsaturated isocyanates, US 3,882,083; olefinic siloxanes, US 3,989,667; unsaturated hydrocarbon diesters, US 4,256,870, US 4,476,166 and US 4,562,096, and conjugated eneynes. US 4,465,818 and US 4,472,563; other organic compounds such as hydroperoxides, US 4,061 ,609; ketones, US 3,418,731 ; sulfoxides, amines, nitriles, US. 3,344,111 ; diaziridines, US 4,043,977; and various salts, such as US 3,461 ,185, phosphorous compounds preferably excluded. Examples thereof include the acetylenic alcohols of US 3,445,420, such as ethynylcyclohexanol and methyl butynol; the unsaturated carboxylic esters of US 4,256,870, such as diallylmaleate and dimethyl maleate; and the maleates and fumarates of US 4,562,096 and US 4,774.111 , such as diethyl fumarate, diallyl fumarate and bis-(methoxyisopropyl)maleate. The half esters and amides of US 4,533,575; and the inhibitor mixtures of US 4,476,166 would also be expected to behave similarly.

The above-mentioned patents relating to conventional inhibitors for platinum group metal-containing catalysts are incorporated herein by reference.

Component (E):

The siloxane composition according to the invention may comprise further ingredients (E) as auxiliary additives. The siloxane compositions according to the invent- tion may also comprise further ingredients, by way of example solvents (E), fillers, pigments or process aids added to achieve better process properties for the invent- tive polymer composition (A) to (D).

If the compositions of the present invention optionally comprise solvents these solvents are usual organic solvents in the range of less than 20 wt.-% , preferably less than 10 wt.-% and most less than 5 wt.-% related to (A) to (D). Appropriate reactive solvents can be selected from the group of olefinic hydrocarbons such as alpha-olefins, e.g. C₈-C₂₅-alpha-olefins, preferably Ci₄-C₂o-alpha-olefins or evaporable siloxanes having molweight below 518 g/mol without alkenyl or SiH groups. Mixtures of alpha-olefins can also be used. Other additives falling under definition of component (E) are selected from the group of heat stabilzers, coloring compounds or pigments, antioxidants, biocides, fungicides, such as Preventol®, Katon®, Dowicil®, fillers, espec. spherical silsesquioxanes for getting additional antiblocking properties of release layers, anti- mist additives as disclosed in US 6,586,535 or US 2003/0134043, anchorage additives, slipping agents as disclosed in EP 819735 A1 and further auxiliary components typical for silicone release compositions. These other ingredients may be contained in said reactive silicon-based composition in a total amount of up to 20 wt.%. If fillers are used in inventive compositions the amount of filler is between 1 to 300 weight parts, preferably 15 to 80 weight parts related to 100 weight parts of component (A). The fillers are preferably selected from the groups of hydrophilic or hydrophobic, preferably surface-modified fillers. The fillers may serve as reinforcing fillers, thickening additive, as anti-blocking or anti-friction or matting additive.

The fillers include by way of example are all of the fine-particle fillers, i.e. those having particles smaller than 100 μm (sieve residue), i.e. preferably composed of particles smaller than this value. These can be mineral fillers, such as silicates, carbonates, nitrides, oxides, carbon blacks, or silicas being fumed or precipitated silica, whose BET-surface areas are from 0.3 to 400 m²/g, these preferably having been specifically surface-hydrophobized here. Preferred silicas are, for example, Aerosil® 200, 300, HDK® N20 or T30, Cab-O-Sil® MS 7 or HS 5 more than 200 m²/g BET surface area or precipitated silicas, or wet silicas, are Vulkasil®VN3, or FK 160 from Degussa, or Nipsil®LP from Nippon Silica K.K. and others. Examples of commercially available silicas pre-hydrophobized with various silanes are: Aerosil® R 972, R 974, R 976, or R 812, or, for example, HDK® 2000 or HDK® H30, names for materials known as hydrophobized precipitated silicas or wet silicas are Sipernat®D10 or D15 from Degussa. Surfaced treated fillers having low BET-values are preferred because the ability to build up shear thinning effects is reduced. The preferred surface treatment can be achieved with polyorganosiloxanediols, polyorganosiloxanes, alkoxy- or chloro- silanes, which allows a certain concentration of fillers having lowest degree of thickening properties and shear thinning. Another class of fillers serving as non-transparent non-reinforcing fillers are powdered quartz, diatomaceous earths, powdered crystobalites, micas, aluminum oxides, aluminum hydroxides, oxides and salts of Fe, Mn, Ti, Zn, Zr, chalks, or carbon blacks, whose BET-surface areas are from 0.3 to 50 m2/g. These fillers are available under variety of trade names, examples being Sicron®, Min-U-Sil®, Dicalite®, Crystallite® and serve as matting agents. Such fillers are used if present in a concentration of about 1 to 300 weight parts, preferably 5 to 100 weight parts related to 100 weight parts of (A). Some very special fillers can used as matting agent, agent for increasing the mechanical modulus, or anti-blocking agent, these filler are selected from the group of spherical or fiber shaped thermoplastic powders or fibres such as PTFE-powders, PTFE-emulsions or polyamide, polyurethane or silsesquioxanes powders, thermoplastic fibers cured silicone elastomers or resins und are used if present in amounts of up to 10 weight parts related to 100 weight parts of (A). Tradenames are Teflon® emulsions, Nylon®-powders, Tospearl®, Acemat® , Twaron®, Kevlar®, Dralon®, Diolen® etc.

This type of filler especially if the particles have a spherical shape can preferably be used as anti-blocking agents in the release layer and can give an especially soft touch and low friction properties of the rubber surfaces.

Another class of additives are stabilizers, such as heat stabilizers which can be selected from the group of metal compounds, organic or inorganic salts, complexes of Ce, Fe, La, Mn, Ti and Zr.

Levelling agents, mold release agents are selected from the group consisting of polyether-siloxanes, polyols, polyethers, polyhalides, fatty alcohol or fluoroalkyl derivatives. Another class of important auxiliary additives are adhesion promotors, which can either be incorporated in the composition (A) to (D) or applied in an appropriate form as primer applied prior onto the substrate forseen for getting adhered to the rubber composition under curing.

Adhesion promotors are selected from the group of preferably alkoxysilanes, their condensation product alkoxysiloxanes bearing further organofunctional groups linked over Si-C-bonds, in particular epoxyalkyl, acryloxyalkyl, methacryloxyalkyl, NCO-alkyl, aminoalkyl, urethanealkyl, alkenyl which further can bear SiH groups. Such silanes/siloxanes can be combined with condensation catalyst selected from the group of organometal compounds of Ca, Zr, Zn, Sn, Al or Ti and /or polycyclic aromatic compounds having reactive groups such as alkenyl substituted aromatic biphenyl ethers, esters. The effects of adhesion can be further improved by the addition of selected compounds of component (B),e.g. incorporated by reference US 4,082,726, US 5,438,094; US 5,405,896; US 5,536,803; US 5,877,256; US 6,602,551 ; EP 581504 A; and EP 875536.

The present invention further relates to novel phosphites having the formula:

P(OSiRs)₃ (I)

wherein R is an organic group, specific embodiments are as defined above. Further the present invention relates to the use of one or more phosphites of formula (I) as inhibitors of the hydrosilylation reaction in the curing of polyorganosiloxane compositions and/or silane compositions.

In another preferred embodiment the present invention relates to hydrosilylation- curing polyorganosiloxane compositions and/or silane compositions comprising in parts per weight (pw):

100 pw of component (A) as defined above,

0.1 - 200 pw of component (B) as defined above, 0.1 - 1000 ppm of the transition metal contained in component (C) related to (A) and (B) each as defined above,

0.2 to 12000 ppm of component (D) related to (A) and (B), each as defined above, and

0 to 200 pw of component (E) as defined above.

In polyorganosiloxane and/or silane compositions curable by hydrosilylation according to the invention the molar ratio of platinum to phosphite of formula (I) is preferably from 1 :1 to 1 :6. In another preferred embodiment the present invention relates to a so-called one- part hydrosilylation-curing polyorganosiloxane and/or silane composition, comprising at least one or more phosphites of formula (I).

Under the expression ^'One-Part^'- hydrosilylation-curing polyorganosiloxane and/or silane compositions it is meant in accordance with the present invention, that composition (A) to (D) and optionally (E) comprises all ingredients to get cured under the appropriate conditions, in particular at an increased temperature level of higher than 25 ⁰C.

The present invention further relates to cured polyorganosiloxane and/or silane compositions obtained by curing the hydrosilylation-curing polyorganosiloxane and/or silane compositions as defined above.

Further the present invention relates to the use of the polyorganosiloxane and/or silane compositions of the invention curable by hydrosilylation for the manufacture of shaped formed articles, extruded articles, coatings, sealants.

In particular, in the manufacture of shaped articles formed under extrusion there is an increasing demand for curing such rubber articles via a hydrosilylation reaction while replacing peroxides. The cure rates necessary for such technology are rather high i.e. the cure time is short, and is in general below 2 min at 110 ⁰C in order to get a bubble free cured elastomehc article. These requirements can be achieved with the hydrosilylation-curing polyorganosiloxane and/or silane compositions according to the invention. At the same time the hydrosilylation-curing polyorganosiloxane and/or silane compositions according to the invention have a storage stability at 25° C of preferably more than 30 days.

The term storage stability used in accordance with the present invention means the tio time at 25 ⁰C, which is the time wherein 10 % of the elastic modulus of the fully cured material at 25 ⁰C is reached, after preparation of the reactive composition. On the other hand the cure time of the hydrosilylation-curing polyorganosiloxane and/or silane compositions is the time t₉₀ at 110 ⁰C, which is the time wherein 90 % of the elastic modulus of the fully cured material at 100 ⁰C is reached after preparation of the reactive composition. The elastic modulus is measured with a Rheometer MDR 2000 of Alpha Technologies.

Another important application of the hydrosilylation-curing polyorganosiloxane and/or silane compositions according to the invention are siloxane coatings e.g. release coatings for thermoplastic films which must be cured below 110 ⁰C within a reasonable short curing time given by the band speed of the coating machines which is usually between 50 - 1000 m/min whereby the coating thickness is usually between 0.05 - 1 mm.

The present invention further provides a process for the manufacture of the hydrosilylation-curing polyorganosiloxane, comprising mixing one or more

(A) polyorganosiloxanes and/or silanes having in average at least two alkenyl groups,

(B) one or more polyorganosiloxanes and/or silanes having in average at least two SiH groups,

(C) one or more transition metal compounds, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium,and platinum,

(D) one or more phosphites as defined above, and (E) optionally one or more auxiliary agents, in a mixing apparatus.

Preferably the following procedure is applied to prepare the preferred 'One-Part' - composition of the invention. That is, the components (A) to (E) are mixed first to non-reactive compositions, that is, compositions which do not contain (A), (B) and (C) at the same time.

Although the One-Part'-composition of the invention has a very high stability, i.e. a very long storage time, it is nevertheless in practice preferred to prepare and supply two or three partial compositions, wherein each partial composition does not contain all of the components (A) to (E). Those partial compositions can be stored practically for more than 100 days. The manufacturer usually prepares the reactive composition i.e. mixing of the partial compositions. The reactive composition has then still a storage stability of more than 30 days.

Those preferred partial compositions are most preferably two partial compositions containing the following components:

- (A) + (B) + (D) + optionally (E), e.g. fillers; (A) + (C) + optionally (E), e.g. fillers.

Such a combination of the partial compositions is preferred because a 1 :1 mixture per volume is achievable, which easily to be mixed by static mixers. Another advantage of such a combination of partial compositions is the avoidance of the simultaneous presence of (B) and (C) which detrimental because of a possible occurrence of discolouration. On the other hand the combination of (A) and (C) has a stabilizing effect on the transition metal catalyst component (C).

The partial compositions as defined before are preferably prepared for example with in a mixing apparatus selected from kneaders, dissolvers, single or twin screw extruders, LIST-mixing apparatuses, BUSS-co-kneader, Banbury mixers or ^'press- mixers^' of Voith, two roll-mixers.

The reactive preferably One Part compositions are preferably prepared by mixing the partial compositions by mixing the with them for example in a mixing apparatus selected from static mixers, kneaders, like two blade kneaders, dissolvers, single or twin screw extruders, LIST-mixing apparatuses, BUSS-co-kneader, Banbury mixers or ^'press-mixers^' of Voith, two roll-mixers, multi roll coating mixtures.

Accordingly the present invention also relates to the partial composition comprising components (A) + (B) + (D) + optionally (E).

Preferred compositions:

The inventive compositions preferably applied as ^'One-Part^'-composition can be used preferably as a so-called paper release coating, as a liquid rubber or as a high consistency rubber composition having optionally incorporated reinforcing fillers, which for example have the following compositions:

(A) 100 pw of one or more polyorganosiloxanes and/or silanes having in average at least two alkenyl groups and a viscosity of 50 mPa.s - 100 kPa.s at 25 ⁰C,

(B) 0.1 to 100 of one or more polyorganosiloxanes and/or silanes having in average at least two SiH groups in an amount to achieve a molar ratio of SiH : Si-alkenyl groups of 0.8 to 6 : 1 ,

(C) 1 - 500 ppm calculated as metal related to (A) and (B) of one or more transition metal compounds, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum,

(D) one or more phosphites according to formula (I) preferably in an amount to achieve a molar ratio of 1 :1 to 6:1 of component (D) to the metal atom of component (C), and (E) 0 - 200 pw of one or more reinforcing silicas having a BET-surface of more than 50 m²/g and optionally further auxiliary additives.

EXAMPLES

Synthesis of the phosphite inhibitors

The comparative triorganophosphites (1-6) have been synthesized according to the following reaction scheme:

3 R₃SiO M⁺ + PCI₃- →- P(OSiR₃J₃ + 3 MCI

R= trialkylsilyl, tris(triorganosiloxy)silyl M= Li, Na wherein PCb and the corresponding metal alkoxide obtained from a reaction of an alcohol with sodium hydride or n-butyl lithium undergo a reaction in dried tetrahydro- furane, see also A. Earnshaw, N. Greenwood (1997): The Chemistry of the Elements - Second Edition.

The phosphites according to the invention have been synthesized according to the following reaction scheme: A solution of the selected alcohol in THF (tetrahydrofurane), which has been dried over sodium and sodium hydride, was added dropwise under vigorously stirring under a dry argon atmosphere to a suspension of NaH dissolved in THF or n-butyl lithium dissolved in hexane at room temperature (25 ⁰C). After the indicated period of stirring and cooling to room temperature the solvent was removed under reduced pressure to dryness, then hexane was added and the suspension containing the organic phase, some hexane and salts are separated by filtration using a canula system. The filtered organic phase was concentrated under reduced pressure followed by crystallization step, wherein the residue has been placed in a freezer at -15 ⁰C for crystallization. The solid product was purified by decantation at -78 ⁰C and dried under vacuum (20 mbar). Example 1 : Synthesis of tris(triphenylsilyl)phosphite (1)

The solution of triphenylsilanol (5 g, 0.018 mol) in 50 ml of dried and deoxidized THF was added dropwise on energetic stirring to a suspension of NaH (0.8 g, 0.036 mol) in 20 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 2 hours at 50 ⁰C. After this time the mixture was filtered off by a canula system. PCI3 (0.745 g, 5.42x10^"3mol) was added to the solution of sodium thphenylsilanolate and the mixture was stirred for 12 h at 60 ⁰C . At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the benzene was added. The suspension obtained was wormed up to 65 ⁰C and filtered off by canula system, and then the solvent was evaporated under reduced pressure. The solid obtained was washed by two portion of hexane. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR, ²⁹Si NMR. Tris(triphenylsilyl)phosphite was obtained with a yield of 94 %.

Spectroscopic data: 1H NMR (C₆D₆, δ, ppm): 7.60 (d), 7.18 (m), 7.06 (t), (45H, o.m.p-Ph),

¹³C NMR (C₆D₆, δ, ppm): 136.03; 136.01 ; 134.74; 130.19; 130.88; 128.12; 3¹P NMR (C₆D₆, δ, ppm): 112.49 ²⁹Si NMR (C₆D₆, δ, ppm): 13.28 (d, J_Si-P = 10 Hz).

Example 2: Synthesis of phosphorosilsesquioxane (2)

The solution of POSS-iso-octyl (POSS = Polyorganosilsequioxan) 5 g, 4.22x10^"3mol) in 30 ml of dried and deoxidized THF was added dropwise on energetic stirring to a suspension of NaH (0.608 g, 0.025 mol) in 10 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 24 hours at room temperature. After this time the mixture was filtered off by a canula system.

PCI₃ (0.562g, 4.09x10^"3mol) was added to the solution of sodium POSS-trisilanolate and the mixture was stirred for 24 h at room temperature, and then stirred for 2 h at

50 ⁰C. At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the hexane was added. The suspension obtained was filtered off by canula system and the solvent was evaporated under reduced pressure. The phosphorous silsequioxane was obtained with a yield of 94 %.

¹H NMR (C₆D₆, δ, ppm): 2.24 (bm, 7H, -CH-); 1.8-0.8 (bm, 112H, H-aliphatic); ¹³C NMR (C₆D₆, δ, ppm): 54.79, 54.39, 53.91 ; 31.03, 30.08, 29.28; 25.47, 25.18,

24.85, 23.94

³¹P NMR (C₆D₆, δ, ppm): 84.64.

Example 3: Synthesis of tris(tri-tert-butoxysilyl)phosphite (3)

The solution of tri-te/t-butoxysilanol (5 g, 0.019 mol) in 50 ml of dried and deoxidized THF was added dropwise on energetic stirring to a suspension of NaH (0.912 g, 0.038 mol) in 20 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 24 hours at room temperature. After this time the mixture was filtered off by a canula system. PCI3 (0.826 g, 6.02x 10^~3mol) was added to the solution of sodium tri-te/t-butoxysilanolate and the mixture was stirred for 24 h at 55 ⁰C. At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the pentane was added. The suspension obtained was filtered off by canula system, and then the solvent was evaporated under reduced pressure giving white solid. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR. Tris(tri-te/t-butoxy- silyl)phosphite was obtained with a yield of 92 %. Spectroscopic data:

¹H NMR (C₆D₆, δ, ppm): 1.52 (81 H, O⁴Bu),

¹³C NMR (C₆D₆, δ, ppm): 74.89; 74.41 ; 74.16; 73.01 ; 72.86 (-0-CMe₃); 31.2; 31.30; 31.32; 31.39; 31.67 (-Me);

³¹P NMR (C₆D₆, δ, ppm): 109.62.

Example 4: Synthesis of tris(methyldiphenylsilyl)phosphite (4)

A solution of 4.76 g (0.047 mol) of triethylamine in 150 ml of water and 300 ml of diethyl ether were placed in a 1 -liter capacity two-neck round-bottomed flask, equipped with a magnetic stirrer and a thermometer. The reaction flask was cooled by an ice bath. When the temperature of the mixture had fallen to 0 ⁰C, 1 O g (0.043 mol) of chloromethyldiphenyl silane was added dropwise to vigorously stirred a mixture. After 30 minutes, the reaction mixture was transferred into the 1 -L separatory funnel and the water layer was removed. The organic layer was washed by two portions of water. The ether solution was finally dried over 20 g of anhydrous magnesium sulphate. The solvent was evaporated under reduced pressure. The product obtained was distillated under vacuum using trap-to-trap technique.

The methyldiphenylsilanol (3 g, 0.014 mol) was added dropwise on energetic stirring to a suspension of NaH (0.67 g, 0.028 mol) in 30 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 24 hours at room temperature. After this time the mixture was filtered off by a canula system. PCI3 (0.6 g, 4.37x10^"3mol) was added to the solution of sodium methyldiphenylsilanolate and the mixture was stirred for 24 h at 55 ⁰C. At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the pentane was added. The suspension obtained was filtered off by canula system, and then the solvent was evaporated under reduced pressure giving white solid. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR, ²⁹Si NMR. Tris(methyldiphenylsilyl)phosphite was obtained with a yield of 91 %.

¹H NMR (CDCI₃, δ, ppm): 7.54 (m), 7.36 (m) (3OH, o,m,p-Ph); 0.61 (s, 9H, SiMePh₂) ¹³C NMR (CDCI₃, δ, ppm): 137.44; 133.87; 129.46; 127.62 (-Ph); -0.44 (-Me) 3¹P NMR (CDCI₃, δ, ppm): -13.61 2⁹Si NMR (CDCI₃, δ, ppm, INEPT): -7.10.

Example 5: Synthesis of tri(tris(trimethylosiloxy)silyl)phosphite (5)

A solution of 3.36 g (0.033 mol) of triethylamine in 150 ml of water and 300 ml of diethyl ether were placed in a 1 -liter capacity two-neck round-bottomed flask, equipped with a magnetic stirrer and a thermometer. The reaction flask was cooled by an ice bath. When the temperature of the mixture had fallen to 0 ⁰C, 10 g (0.030 mol) of ths(trimethylsiloxy)chlorosilane was added dropwise to vigorously stirred a mixture. After one hour, the reaction mixture was transferred into the 1 -L separatory funnel and the water layer was removed. The organic layer was washed by two portions of water. The ether solution was finally dried over 20 g of anhydrous magnesium sulphate. The solvent was evaporated under reduced pressure and the product obtained was used for the next step without additional purification.

The portion of ths(thmethylsiloxy)silanol (5 g, 0.016 mol) was added dropwise on energetic stirring to a suspension of NaH (0.57 g, 0.024 mol) in 40 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 24 hours at room temperature. After this time the mixture was filtered off by a canula system. PCI₃ (0.69 g, 5.07x10^"3mol) was added to the solution of sodium ths(trimethylsiloxy)silanolate and the mixture was stirred for 24 h at 60 ⁰C. At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the pentane was added. The suspension obtained was filtered off by cannula system, and then the solvent was evaporated under reduced pressure giving colourless oil. The product was analyzed by ¹H NMR, ¹³C NMR, ³¹P NMR, ²⁹Si NMR. Tris(trimethylsiloxy)silylphosphite was obtained with a yield of 95 %.

Spectroscopic data:

¹H NMR (CDCI₃, δ, ppm): 0.32 (s, 81 H, -Me)

¹³C NMR (CDCI₃, δ, ppm): 2.36 (-Me)

³¹P NMR (CDCI₃, δ, ppm): 111.73

²⁹Si NMR (CDCI₃, δ, ppm, INEPT): 11.89 (J_Sl-P = 60.27 Hz).

Example 6: Synthesis of tris(tri-iso-propylsilyl)phosphite (6)

A solution of 5.76 g (0.057 mol) of thethylamine in 150 ml of water and 300 ml of diethyl ether were placed in a 1 -liter capacity two-neck round-bottomed flask, equipped with a magnetic stirrer and a thermometer. The reaction flask was cooled by an ice bath. When the temperature of the mixture had fallen to 0 ⁰C, 10 g (0.052 mol) of tri-/so-propylchloro silane was added dropwise to vigorously stirred a mixture. After one hour, the reaction mixture was transferred into the 1 -L separatory funnel and the water layer was removed. The organic layer was washed by two portions of water. The ether solution was finally dried over 20 g of anhydrous magnesium sulphate. The solvent was evaporated under reduced pressure. The solvent was evaporated under reduced pressure and the product obtained was used for the next step without additional purification.

3 + PCI, P_tO-Si — ( I + 3 NaCI

The tri-/so-propylsilanol (5 g, 0.0287 mol) was added dropwise on energetic stirring to a suspension of NaH (1.00 g, 0.042 mol) in 40 ml of THF at room temperature under dry argon atmosphere over 20 minutes. The reaction was conducted for 24 hours at room temperature. After this time the mixture was filtered off by a canula system. PCI3 (1.24 g, 9.08x10^"3mol) was added to the solution of sodium methyldiphenylsilanolate and the mixture was stirred for 24 h at 60 ⁰C. At the next step the content was cooled to room temperature and the solvent was removed under reduced pressure, then the pentane was added. The suspension obtained was filtered off by canula system, and then the solvent was evaporated under reduced pressure giving colourless oil. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR, ²⁹Si NMR. Tris(methyldiphenylsilyl)phosphite was obtained with a yield of 94 %.

¹H NMR (CDCI₃, δ, ppm): 1.21 (d, 54H, -Me); 1.11 , 1.04 (m, 9H, Si-CHMe₂) 1³C NMR (CDCI₃, δ, ppm): 18.48, 18.45 (-Me), 13.88 (Si-CHMe₂) 3¹P NMR (CDCI₃, δ, ppm): 110.18 2⁹Si NMR (CDCI₃, δ, ppm, INEPT): 15.23 (J_Sl-P = 14.66 Hz).

Example 7: Synthesis of tricyclohexylphosphite (7 -comparison)

This phosphite compound was prepared starting from 10 g (100 mmol) of cyclohexanol, 3.66 g of NaH (140 mmol) and 3.84 g (28 mmol) of PCI₃. The reaction of cyclohexanol with NaH was carried out for 24 h at 50 ⁰C. After addition of PCI₃ the mixture was stirred for another 12 h at 65 ⁰C and the product was isolated at room temperature (25 ⁰C) afterwards. Yield 8.28 g (90 %).

The corresponding nuclear magnetic spectras show the characteristic signals: 1H-NMR (300 MHz, C₆D₆, 300 ⁰K) δ(ppm) = 4.27(m, 3H, -OCH); 1.92 (m), 1.64 (m), 1.19 (m) (3OH, Cy);

¹³C-NMR (75.42 MHz, C₆D₆, 300 ⁰K) δ(ppm) = 71.21 (d, -OCH-), 35.05 (d), 25.88,

24.18 (Cy);

³¹P-NMR (121.47 MHz, C₆D₆, 300 ⁰K) δ(ppm) = 138.85.

Synthesis of platinum complex compounds

The synthesis follows a pathway in that e.g. the well-known divinyl- tetramethyldisiloxane (^'DVTMDS^') bridged binuclear platinum complex (Karstedt's catalyst) can be cleaved by any nucleophile (e.g. phosphite), giving a mononuclear platinum complexes, according to the equation:

Pt - P(OSiR₃J₃

Complexes (1.2. - 6.2) have been synthesized by treatment of calculated amounts of Karstedt's catalysts in a xylene solution and in the presence of the corresponding phosphites. Reactions were conduced for 24 h at room temperature. After this time the mixtures were filtered off by a cannula system and solvent was evaporated under vacuum for 24 h at 50 ⁰C. Solid materials were three times washed with pentane by decantation at -70 ⁰C. New platinum complexes

(1.2) (2.2)

(3.2) (4.2)

(5.2) (6.2)

Example 8: Complex (1.2) comprising the phosphite of example 1

To a Schlenk's tube containing 1.0 g (1.17 mmol) of phosphite compound (1) 15 ml of benzene was added and a mixture was wormed up to 50 ⁰C to dissolve the phosphite, then a portion of 7.48 g (1.15 mmol of Pt) solution of Karstedt catalyst (3 % of Pt in xylene) was added. The reaction was conducted for 24 hours at 50 ⁰C 5 on stirring the reaction mixture with a magnetic stirrer. After this time the solvent was evaporated and the solid obtained was dried under vacuum. Crude mixture of the complex was washed by two portions of pentane (5 ml) then dried under vacuum. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR, ²⁹Si NMR. The yield of the complex was 97 %.

10 Spectroscopic data:

¹H NMR (C₆D₆, δ, ppm): 7.60 (d), 7.18 (t), 7.06 (t) (45H, o,m,p-Ph); 2.43 (m),

2.25(m) (6H, -CH=CH₂); 0.473 (s), 0.471 (s) (6H, -Me); -0.09 (6H, -Me) 1³C NMR (C₆D₆, δ, ppm): 136.18; 133.93; 130.45; 130.88; 128.13; 50.60 (d, J_C-_R = 6.6 Hz); 46.14 (d, Jc-R = 17.58 Hz); 1.99, 1.95, -0.83 15 ³¹P NMR (C₆D₆, δ, ppm): 120.82; 94.25; 67.68 (J_P-Pt = 6454.55 Hz).

Example 9: Complex (2.2) comprising the phosphite of example 2

To a Schlenk's tube containing 1.0 g (0.825 mmol) of phosphite compound (2) at room temperature in argon atmosphere, a portion of 5.2 g (0.8 mmol of Pt) solution of Karstedt catalyst (3 % of Pt in xylene) was added. The reaction was conducted for 24 25 hours at room temperature on stirring the reaction mixture with a magnetic stirrer. After this time the solvent was evaporated and the complex obtained was dried under vacuum for 24 h at 50 ⁰C. The product was analyzed by ¹HNMR, ¹³CNMR₁ ³¹P NMR . The yield of the complex was 98 %. ¹H NMR (C₆D₆, δ, ppm): 2.43 (m), 3.4-2.8 (m) (6H, -CH=CH₂); 2.2 (bm, 7H, -CH-); 1.7-0.83 (bm, 112H, H-aliphatic); 0.53 (s), 0.516 (s) (6H, -Me); - 0.13(m), - 0.25(m) (6H, -Me)

¹³C NMR (C₆D₆, δ, ppm): 57.55, 57.25, 56.47, 55.84 (-CH=CH₂); 54.34, 53.90; 31.08, 30.08, 29.28; 25.46, 23.94; 1.44, -2.19, -2.04

³¹P NMR (C₆D₆, δ, ppm): 110.64, 83.122, 55.58 (J_P-Pt = 6687.6 Hz).

Example 10: Complex (3.2) comprising the phosphite of example 3

To a Schlenk's tube containing 1.0 g (1.22 mmol) of the phosphite compound (3) a portion of 7.80 g (1.20 mmol of Pt) solution of Karstedt catalyst (3% of Pt in xylene) was added. The reaction was conducted for 24 hours at room temperature on stirring the reaction mixture with a magnetic stirrer. After this time mixture was filtered off by canula system, then the solvent was evaporated and the solid obtained was dried under vacuum. Crude mixture of the complex was washed by two portions of pentane (3 ml) at minus 70 ⁰C, then dried under vacuum. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR. The yield of the complex was 97 %.

Spectroscopic data:

¹H NMR (C₆D₆, δ, ppm): 3.26 (m), 2.64 (m), 1.89 (m) (6H, -CH=CH₂); 1.35 (s), 1.34

(S), 1.32 (S), 1.31 (S), 1.28 (s), 1.27 (s) (81 H, -O⁴Bu); 0.313 (s), 0.310 (s) (6H, -Me); - 0.26 (6H, -Me) 1³C NMR (C₆D₆, δ, ppm): 73.72; 48.62 (td, J = 73.0 Hz, J = 6.2 Hz); 42.98; (td, J = 56.2 Hz, J = 17.6 Hz); 31.85; 31.33; 1.76; 1.74; -1.05

³¹P NMR (C₆D₆, δ, ppm): 108.59; 81.74; 54.90 (J_P-Pt = 6521.42 Hz). Example 11 : Complex (4.2) comprising the phosphite of example 4

To a Schlenk's tube containing 0.5 g (0.746 mmol) of the phosphite compound (4) at room temperature in argon atmosphere, a portion of 4.72 g (0.726 mmol of Pt) solution of Karstedt catalyst (3 % of Pt in xylene) was added. The reaction was conducted for 24 hours at room temperature on stirring the reaction mixture with a magnetic stirrer. After this time the solvent was evaporated and the complex obtained was dried under vacuum for 24h at 50 ⁰C. The product was analyzed by ¹HNMR, ³¹P NMR . The yield of the complex was 98 %.

¹H NMR (C₆D₆, δ, ppm): 7.58 (m), 7.37 (m) (3OH, o,m,p-Ph); 2.80-3.80 (m) (6H, - CH=CH₂); 0.62 (s, 9H, -SiPh₂Me); 0.43, 0.42 (s) (6H, -Me); -0.23, -0.35 (6H, -Me)

³¹P NMR (C₆D₆, δ, ppm): 123.11 , 97.04, 70.98 (J_P-Pt = 6332.6 Hz).

Example 12: Complex (5.2) comprising the phosphite of example 5

To a Schlenk's tube containing 1.0 g (1.034 mmol) of the phosphite compound (5) a portion of 6.39 g (0.98 mmol of Pt) solution of Karstedt catalyst (3 % of Pt in xylene) was added. The reaction was conducted for 24 hours at room temperature on stirring the reaction mixture with a magnetic stirrer. After this time mixture was filtered off by canula system, then the solvent was evaporated and the pale yellow oil was dried under vacuum. The product was analyzed by ¹H NMR, ¹³C NMR, ³¹P NMR. The yield of the complex was 98 %. Spectroscopic data:

¹H NMR (C₆D₆, δ, ppm): 3.33 (m), 2.84 (m), 2.54 (m) (6H, -CH=CH₂); 0.62 (s, 6H,

SiMe₂), 0.31 (s, 81 H, -SiMe₃); 0.14 (s, 6H, SiMe₂)

¹³C NMR (C₆D₆, δ, ppm): 48.67 (s) (d, J₀-Pt = 168.43 Hz), 48.58(s) (d, J_c-pt = 168.38 Hz); 44.72 (s) (d, Jc-pt = 111.30 Hz); 44.49 (d, Jc-pt = 110.85 Hz); 2.70 (-SiMe₃); 2.07, 2.00; 1.67, 1.63 (SiMe₂)

³¹P NMR (C₆D₆, δ, ppm): 113.59; 87.21 ; 60.77 (J_P-Pt = 6415.73 Hz).

Example 13: Complex (6.2) comprising the phosphite of example 6

To a Schlenk's tube containing 1 g (1.82 mmol) of the phosphite compound (6) at room temperature in argon atmosphere, a portion of 11.25 g (1.73 mmol of Pt) solution of Karstedt catalyst (3 % of Pt in xylene) was added. The reaction was conducted for 24 hours at room temperature on stirring the reaction mixture with a magnetic stirrer. After this time the solvent was evaporated and the complex obtained (pale yellow solid) was dried under vacuum for 6 h at 50 ⁰C. The product was analyzed by ¹HNMR, ¹³C NMR, ³¹P NMR. The yield of the complex was 97 %.

Spectroscopic data:

¹H NMR (C₆D₆, δ, ppm): 3.13 (m), 2.61 (m) 2.40 (m) (6H, -CH=CH₂); 1.38(m), 1.20(S), 1.18(s) (63H, /so-Pr); 0.62 (s, 6H, SiMe₂); 0.02 (s, 6H, SiMe₂)

¹³C NMR (C₆D₆, δ, ppm): 49.24 (s) (d, J_C-_R = 168.13 Hz) 49.14 (d, J_C-_R = 168.13 Hz); 44.39 (s) (d, J₀-Pt = 107.08 Hz); 44.16 (s) (d, J₀-Pt = 107.38 Hz) 18.68 (-Me); 14.57 (-CH(Me)₂); 2.15, -1.41 (SiMe₂)

³¹P NMR (C₆D₆, δ, ppm): 112.68, 86.40, 60.17 (J_P-Pt = 6379.05 Hz). Test conditions for reactivity, i.e cure rate and inhibition (pot-life, storage stability)

The phosphites (1 ) to (6) of example 1 -6 were tested in a hydrosilylation reaction, whereby the phosphite was applied as component (D). The alkenyl component (A) is realized by a liquid linear polydimethylsiloxanes having 2 vinyl endgroups, the Si- hydrogen component (B) is realized by a multifunctional polydimethyl- methylhydrogensiloxane (crossl inker), and as component (C) a (platinum)-Karstedt catalyst was choosen.

The testing composition consists of 100 g of component (A) which is a vinyl terminated polydimethylsiloxane with an average chain length of 150 units and a viscosity of 200 to 300 mPa.s (25°C). 1.32 mol.%, 0.177 mmol/g Of -CH=CH₂ groups attached to the Si atoms from Momentive Performance Materials.

As second component 7.7 g of the component (B) are admixed, which is a polydimethyl-methylhydrosiloxane, having 1.23 mol.%, of SiH groups represented by the general formula MD^H5oDnoM with 4.42 mmol SiH/g and a viscosity of 35 mPa.s.

As third component a solution of 7.8 to 50.1 mg (D) 20-wt.% in toluene providing a molar P : Pt ratio of 1 : 1 to 4: 1 are admixed with a Krups mixer at 25 ⁰C and ambient air. The weights of (A) and (B) provide a molar ratio of in terms of [≡SiH] to [≡Si-CH=CH₂] of 1.93 to 1.

After getting mixed (A)₁(B) and (D) a solution of the component (C) of 42.2 mg (4.76 10^~3 mmol) of the Karstedt catalyst solution (2.2 wt.% Pt) in xylene was dispersed in the components (A)₁(B) and (D) corresponding to 10 ppm Pt as metal in total of (A) and (B).

The time for gelling (doubling of viscosity) at 25 ⁰C was measured as pot-life (as measure for storage stability). The relative curing time was measured as the time required until disappearance of 95 % of the initial SiH-signal in the ¹H-NMR after storage (A) to (D) at 120 ⁰C. In addition the progress of the reaction has been monitored by DSC-method (Differential Scanning Calorimetry). All samples were mixed well for half an hour in before the DSC analysis. The DSC measurements were made using a DSC 204 NETCH. The instrument was calibrated with indium (ΔH = 28.4 J/g), the heating rate is 10 °K/min running from 20 to 220 ⁰C, hold for 5.0 min at 30 ⁰C under helium atmosphere. The values are average values of 3 runs for each composition.

All the manipulations after mixing were carried out under argon using standard Schlenk and vacuum techniques. ¹H-, ¹³C- and ³¹P-NMR-spectra were recorded on a Varian Gemini 300 VT and Varian Mercury 300 VT spectrometers in benzene-d6, acetone-d6.

The chemicals were obtained from the following sources: alcohols, benzene-d₆ and acetone-dβ, Karstedt catalyst from Aldrich, Si-vinyl and SiH-siloxanes from Momentive Performance Materials, solvents from POCH Gliwice (Poland).

Table 1. Pot-life and cure time the phosphites of examples 1-6

Table 2

Phospite [Pt] : [P] Pot-life at 25⁰C Curing time at 120 ^<€

[h] [sec]

1:1 >168 600

(7) 1:2 >168 900 (comparison)

1:5 >168 3000 Table 3: Pot-life and cure time the phosphites of examples 8- 13

(the platinum(O) complexes)

The pot-life times and curing times increase with the increasing ratio of [P] : [Pt] i.e. more phosphite introduced via component (D) increase that time. The reference phosphite (7) has a pot-life time of more than 7 days, whereas the curing time for (7) is 600 to 3000 sec depending on the molar ratio of [P] : [Pt] of the components (D) to (C).

The addition of the organosilyl-phosphite complex compounds (1.2) to (3.2.) and

(5.2) to (6.2) into the test composition surprisingly show a superior pot-life from 12 hours to >960 h (>40 days), and at the same relatively short curing times of from

180 to 300 seconds.

This effect can be used particularly in a kind of ^'One-Part^'-composition, which is potentially highly reactive on the one hand but can be stored after getting mixed for

7 days on the other hand. Another advantage of the silyl phosphites is the superior solubility in the silicone matrix compared e.g. to trisaryl- or trisalkylphosphites.

Claims

CLAIMS:

1. Hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions, comprising one or more phosphites having the formula:

P(OSiRs)₃ (I)

wherein R is an organic group.

2. Hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions according to claim 1 , comprising:

(A) one or more polyorganosiloxanes and/or silanes having in average at least two alkenyl groups,

(B) one or more polyorganosiloxanes and/or silanes having in average at least two SiH groups,

(C) one or more transition metal compounds, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum,

(D) one or more of the phosphites as defined in claim 1 , and (E) optionally one or more auxiliary agents.

3. Compositions according to claim 1 or 2, wherein in the formula (I) the groups R are different or identical and are selected from the group of substituents, consisting of alkyl, alkoxy, aryl, aryloxy, silyloxy or the three -OSiR₃ groups are linked together and form a three-dimensional siloxane cage structure.

4. Compositions according to any of claims 1 to 3, wherein the phosphites of the formula (I) are selected from the group, consisting of:

P(OSiRs)₃ (Ia), wherein R is selected from an alkoxy and an aryloxy group,

P(OSiRs)₃ (Ib),

wherein R is selected from an alkyl and an aryl group, and

wherein R is selected from a silyl oxy group, or the three -OSiR₃ groups are linked together and form a three-dimensional siloxane cage structure.

5. Compositions according to any of claims 1 to 4, wherein the phosphites are selected from the group consisting of:

6. Transition metal compound, comprising at least one phosphite having the formula:

P(OSiRs)₃ (I)

wherein R is an organic group.

7. Transition metal compound, obtained by reacting a transition metal compound, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum, with at least one phosphite of the formula

P(OSiRs)₃ (I)

wherein R is an organic group.

8. Transition metal compounds according to claims 6 or 7, wherein the transition metal is platinum.

9. Phosphites having the formula:

P(OSiRs)₃ (I)

wherein R is an organic group.

10. Use of one or more phosphites as defined in any of claims 1 to 9 for the manufacture of hydrosilylation-curing polyorganosiloxane and/or silane compositions.

11. Use of one or more phosphites as defined in any of claims 1 to 9 as inhibitors of the hydrosilylation reaction in the curing of polyorganosiloxane compositions and/or silane compositions.

12. Hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions according to any of claims 1 to 9, comprising:

100 pw of component (A),

0.1 - 200 pw of component (B) 0.1 - 1000 ppm of the transition metal contained in component (C) related to (A) and (B),

0.2 to 12000 ppm of component (D), as defined in claim 2, related to (A) and (B),

0 to 200 pw of component (E).

13. Hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions according to any of claims 1 to 9 and 12, comprising a platinum-based hydrosilylation catalyst, and wherein the molar ratio of platinum to the phosphite is from 1 :1 to 1 :6.

14. One-part hydrosilylation-curing polyorganosiloxane and/or silane compositions, comprising at least one or more phosphites as defined in any of the claims 1 to 9.

15. Cured polyorganosiloxane and/or silane compositions obtained by curing the hydrosilylation-curing polyorganosiloxane and/or silane compositions as defined in any of the claims 1 to 9, and 12 to 14.

16. Use of the hydrosilylation-curing polyorganosiloxane compositions and/or silane compositions of any of claims 1 to 9, and 12 to 14 for the manufacture of shaped formed articles, extruded articles, coatings, and sealants.

17. A process for the manufacture of the hydrosilylation-curing polyorganosiloxane compositions of claims 1 to 9, and 12 to 14, comprising mixing (A) one or more polyorganosiloxanes and/or silanes having in average at least two alkenyl groups,

(B) one or more polyorganosiloxanes and/or silanes having in average at least two SiH groups,

(C) one or more transition metal compounds, wherein the transition metal is selected from group consisting of nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum,

(D) one or more phosphites as defined in any of the claims 2 to 9, and

(E) optionally one or more auxiliary agents in a mixing apparatus.