EP1341860A1

EP1341860A1 - Compositions based on functionalised radiation-curable silicones and anti-adhesive coatings obtained from said compositions

Info

Publication number: EP1341860A1
Application number: EP01997529A
Authority: EP
Inventors: Jean-Marc Frances
Original assignee: Rhodia Chimie SAS
Current assignee: Elkem Silicones France SAS
Priority date: 2000-11-21
Filing date: 2001-11-20
Publication date: 2003-09-10
Also published as: WO2002042388A1; US7041710B2; FR2816951B1; US20040110860A1; AU2002220799A1; FR2816951A1

Abstract

The invention concerns a radiation-curable silicone coating, comprising (a) at least a liquid polyorganosiloxane having a viscosity of about 10 to 10000 mPa's at 25 °C and bearing a crosslinkable/polymerisable function Fa on at least a M and/or T unit, and/or at least a crosslinkable/polymerisable function on at least a D unit; (b) at least a liquid linear polyorganosiloxane B having a viscosity of about 10 to 10000 mPa's at 25 °C and bearing two crosslinkable/polymerisable functions Fb on at least a M unit; (c) a cationic photoinitiator of onium borate type.

Description

Compositions based on functionalized silicones curable under irradiation and non-stick coatings obtained from these compositions.

The present invention relates to new silicone compositions curable under UV irradiation and / or electron beam. More specifically, the subject of the invention is new compositions for coatings based on a mixture of polyorganosiloxanes A carrying functions on the D and T units and polyorganosiloxanes B carrying functions on the M units; these functions being crosslinkable and / or polymerizable under UV irradiation or electron beam. These mixtures are effectively crosslinked and / or polymerized under irradiation in the presence of compatible cationic photoinitiators and are particularly suitable for their use in the field of non-stick paper supports.

It is known to use curable silicone compositions to make surfaces non-adherent to materials which would normally adhere to them. To date, it is known to use cationic crosslinkable and / or photopolymerizable compositions to obtain coatings with non-stick properties consisting of silicone oils or resins functionalized with epoxide (s), alkenylether (s), oxetane ( s), etc.

Non-stick coatings are useful for many applications where it is necessary to make a surface or a material which would normally adhere to them non-stick to other materials.

For example, the silicone compositions are used as coatings for release papers and can therefore be combined with adhesive elements which can be easily released without losing their adhesive properties, these elements being pressure-sensitive adhesives for labels, decorative laminates, transfer tape, etc.

Silicone-based non-stick coatings applied to paper, polyethylene, polypropylene, polyester and other such supports are also useful as non-stick surfaces for food handling and industrial packaging applications. For example, when a label is coated with an adhesive and associated with a non-adherent support, it is desirable that the latter be easily separated during use, without its quality of adhesion being reduced by the fact that it was separated from the support. The same principle applies to certain ribbons with a non-stick side and a stick side and which are supplied in reels. In fact, it is necessary for the tape to unroll easily and to retain its adhesion characteristics on the adherent side after a long period of storage and possibly a high pressure between the adhesive side and the non-stick side, in particular insofar as these coils can sometimes reach more than a meter in diameter. We try to obtain these results by coating the non-stick support or the non-stick side of the tape with a silicone-based non-stick composition which will subsequently come into contact in a reversible manner with the adhesive.

It therefore appears necessary that the silicone-based non-stick coatings, when combined with adhesives, give these associations, called silicone / adhesive complexes, a weak release force, stable over time, and stable whatever the pressure exerted. between the non-stick coating and the adhesive, while also ensuring that the adhesive has constant adhesion properties.

On the other hand, the non-stick coatings must fulfill other conditions at best, and in particular, they must harden quickly and the photoinitiator must be selected to be miscible with the silicones of the composition.

These objectives are precisely achieved and optimized according to the present invention. In fact, the silicone compositions developed are specifically adapted for the preparation of non-stick coatings and give the silicone / adhesive complexes a low release force; this detachment force being stable during storage over time and stable whatever the pressure exerted between the non-stick coating and the adhesive. Other advantages will emerge on reading the description.

Thus, the subject of the present invention is a crosslinkable and / or polymerizable composition for non-stick coating based on silicone, curable under irradiation, characterized in that it comprises:

(a) at least one liquid polyorganosiloxane A having a viscosity of around 10 to 10,000 mPa.s at 25 ° C and carrying a crosslinkable and / or polymerizable function Fa on at least one M and / or T unit, and / or of at least one function Crosslinkable and / or polymerizable on at least one unit D,

(b) at least one liquid polyorganosiloxane B having a viscosity of approximately 10 to 10,000 mPa.s at 25 ° C and carrying at least 2 crosslinkable and / or polymerizable Fb functions on at least one M unit,

(c) and an effective amount of a cationic photoinitiator consisting of at least one onium borate.

In general, irradiation is carried out under UN radiation. and / or under an electron beam. For UN radiation, a wavelength of between 200 and 400 nanometers is preferably used between 230 and 360 nanometers. The irradiation time can be short, that is to say less than 1 second and, on the order of a few hundredths of a second for small thicknesses of coatings. The curing time is set (a) by the number of UN lamps. used, (b) by the duration of exposure to UN. and / or (c) by the distance between the composition and the lamp UN. Examples of usable devices for the electron beam are those with pulsed electron beams ("Scanned Electron Beam Acceleratoi") and those with curtained electron beams ("Electron Curtain Accelerator") .

For silicone A, the crosslinkable and / or polymerizable functions Fa are chosen from the group consisting of epoxy, and / or alkenylether and / or oxetane and / or dioxolane functions. Preferably, the function Fa is an epoxy type function. In the context of the invention, the polyorganosiloxane A used is linear and consists of units D (i) of formula (I) and ends with units M (ii) of formula (II), or is cyclic and consists of units D (i) of formula (I) represented below:

in which :

(1) the symbols R, similar or different, represent:

(i) a linear or branched alkyl radical containing 1 to 8 carbon atoms, optionally substituted by at least one halogen, preferably fluorine, the alkyl radicals being preferably methyl, ethyl, propyl, octyl and 3,3,3- trifluoropropyl

(ii) a cycloalkyl radical containing between 5 and 8 cyclic carbon atoms, optionally substituted, (iii) an aryl radical containing between 6 and 12 carbon atoms which can be substituted, preferably phenyl or dichlorophenyl,

(iv) an aralkyl part having an alkyl part containing between 5 and

14 carbon atoms and an aryl part containing between 6 and

12 carbon atoms, optionally substituted on the aryl part by halogens, alkyls and / or alkoxyls containing

1 to 3 carbon atoms,

(v) an OH hydroxyl group or an alkoxyl group containing from 1 to 8 carbon atoms

(vi) a hydrogen radical, (2) the symbols X are similar or different and represent:

(i) an R group, (ii) and / or a crosslinkable and / or polymerizable organofunctional group Fa, preferably an epoxyfunctional, oxetanefunctional, dioxolanefunctional and / or alkenyl etherfunctional group, linked to the silicon of the polyorganosiloxane via a divalent radical containing from 2 to 20 atoms carbon and possibly containing at least one heteroatom, preferably oxygen,

(iii) with at least one of the symbols Fa in one of the patterns (I).

Preferably, the symbols R correspond to the definitions (1) (i) to (1) (iv) given above.

Linear polyorganosiloxanes A can be oils of dynamic viscosity at 25 ° C, of the order of 10 to 10,000 mPa.s at 25 ° C (measured using a BROOKFIELD viscometer, according to AFNOR NFT 76 standard 102 of February 1972), generally of the order of 20 to 5000 mPa.s at 25 ° C and, more preferably still, from 20 to 600 mPa.s at 25 ° C, or gums having a molecular mass of l 'around 1,000,000.

When cyclic polyorganosiloxanes A are concerned, these consist of units (I) which may be, for example, of the dialkylsiloxy, alkylarylsiloxy, (alkyl) (group Fa) siloxy, or (aryl) (group Fa ) siloxy. These cyclic polyorganosiloxanes have a viscosity of the order of 1 to

5,000 mPa.s.

For silicone B, the crosslinkable and or polymerizable functions Fb are chosen from the group consisting of epoxy, and / or alkenylether and / or oxetane and / or dioxolane functions. Preferably, the Fb function is an epoxy type function.

In the context of the invention, the polyorganosiloxane B is linear and consists of units D (iii) of formula (III) and terminated by units M (iv) of formula (IV) shown below: Y

in which :

(1 ') the symbols R, similar or different, represent:

(iv) an aralkyl part having an alkyl part containing between 5 and

14 carbon atoms and an aryl part containing between 6 and

1 to 3 carbon atoms,

(v) an OH hydroxyl group or an alkoxyl group containing from 1 to 8 carbon atoms,

(vi) and a hydrogen radical; (2 ') the symbols Y are similar or different and represent:

(i) an R group,

(ii) and / or a crosslinkable and / or polymerizable organofunctional group Go, preferably an epoxyfunctional, oxetanefunctional, dioxolanefunctional and / or alkenyl etherfunctional group, linked to the silicon of the polyorganosiloxane via a divalent radical containing from 2 to 20 carbon atoms and which may contain at least one heteroatom, preferably oxygen,

(iii) with at least one of the symbols Fb, and preferably two symbols Fb in one of the patterns (IV). Preferably, the symbols R correspond to the definitions (1 ') (i) to

(1 ") (iv) given above.

According to a first advantageous variant of the present invention, the polyorganosiloxane B carries at least 2 units M with at least 2 Fb functions.

According to a second advantageous variant of the present invention, the polyorganosiloxane B also carries at least one Fb function on at least one D unit of formula:

in which Fb and R are definitions identical to those given above.

According to an advantageous variant of the invention, the polyorganosiloxanes B used contain less than 1000 units D (iii), preferably from 10 to 500 units D (iii) and more particularly from 20 to 300 units D (iii).

According to an advantageous variant of the invention, the polyorganosiloxanes B used comprise 4 to 10 organofunctional groups per macromolecular chain.

Linear polyorganosiloxanes B are generally oils of dynamic viscosity of the order of 10 to 10,000 mPa.s at 25 ° C, preferably of the order of 20 to 5,000 mPa.s at 25 ° C and, more particularly again, from 20 to 600 mPa.s at 25 ° C. The reactive functions Fa and Fb can be of very varied structures. As examples of divalent radicals linking a functional group Fa or Fb of the epoxy and / or oxetane type, mention may be made of those included in the following formulas:

(CH ₂ ) ₃ O - CH ₂ - CH- -CH ₂ ; (CH ₂ ) ₃ 0 - CH- -CH ₂

As regards the functional groups Fa or Fb of the alkenyl ether type, mention may be made of those contained in the following formulas:

(0) _n (CH ₂ ) - O-CH = CH ₂ .

(O) _n - (CH ₂ ) - R ³ - O-CH = CH ₂ ;

(°) _n - (CH ₂ ) - O-CH == CH -R ⁴

in which :

• n 'represents 0 or 1 and n "an integer between 1 and 5 • R ³ represents:

- a linear, branched or cyclic Cι-Cι ₂ alkylene radical, optionally substituted,

- or a C ₅ -C ₁₂ arylene radical, preferably phenylene, optionally substituted, preferably by one to three C1-C6 alkyl groups,

. R ⁴ represents a linear or branched alkyl radical in As regards the functional groups Fa or Fb of dioxolane type, mention may be made of those contained in the following formulas:

R10 The onium borate used in the context of the present invention is judiciously chosen; in fact, it must be miscible with the silicone constituents (A) and (B) and therefore it must be capable of dissolving well or dispersing in the composition according to the invention. This onium borate is chosen from onium borates from an element from groups 15 to 17 of the periodic table [Chem. & Eng. News, vol. 63, No. 5, 26 of February 4, 1985] of which: a the cationic entity of borate is selected from: (1 ") the onium salts of formula (I):

[(Rl) _n - A - (R2) _m ] + (l) formula in which:

• A represents an element from groups 15 to 17 such as for example: I, S, Se, P or N,

• R1 represents a CQ-C20 carbocyclic or heterocyclic aryl radical. said heterocyclic radical possibly containing as heteroelements nitrogen or sulfur,

• R2 represents Ri or a linear or branched C1-C30 alkyl or alkenyl radical! said radicals R1 and R ^ being optionally substituted by a C1-C25 alkoxy, C1-C25 alkyl, nitro, chloro, bromo, cyano, carboxy, ester or mercapto group, • n is an integer ranging from 1 to v + 1, v being the valence of the element A,

• m is an integer ranging from 0 to v - 1 with n + m = v + 1, (2 ") the oxoisothiochromanium salts described in patent application WO 90/11303, in particular the sulfonium salt of 2-ethyl-4-oxoisothiochromanium or of 2-dodecyl-4-oxoisothio-chromanium, m and the entity anionic borate has the formula [BX ' _a R ³ ) -,] - in which: - a and b are integers ranging for a from 0 to 3 and for b from 1 to 4 with a + b = 4, - the symbols X 'represent:

* a halogen atom (chlorine, fluorine) with a = 0 to 3,

* an OH function with a = 0 to 2, - the symbols R ³ , identical or different, represent: t> a phenyl radical substituted by at least one electron-withdrawing group such as for example OCF3, CF3, NO2, CN, and / or by at least 2 halogen atoms (especially fluorine), and this when the cationic entity is an onium of an element from groups 15 to 17,

> a phenyl radical substituted by at least one element or an electron-withdrawing group, in particular a halogen atom (especially fluorine), CF3, OCF3, NO2, CN, and this when the cationic entity is an organometallic complex of an element of the groups 4 to 10

> an aryl radical containing at least two aromatic rings such as for example biphenyl, naphthyl, optionally substituted by at least one element or an electron-withdrawing group, in particular a halogen atom (fluorine in particular), OCF3, CF3, NO2, CN, whatever the cationic entity.

Without being limiting, more details are given below with regard to the subclasses of onium borate which are more particularly preferred in the context of the use in accordance with the invention.

According to a first preferred variant of the invention, the species of the anionic borate entity which are very particularly suitable are the following: r [B (C ₆ F ₅ ) ₄ ] - 5 ': [B (C ₆ H ₃ (CF ₃ ) ₂ ) 4] -

2 '[(C ₆ F ₅ ) 2BF ₂ ] - 6': [B (C ₆ H ₃ F ₂ ) 4] -

3 '[B (C ₆ H ₄ CF ₃ ) 4] - T. [C ₆ F ₅ BF ₃ ] -

4 '[B (C ₆ F ₄ OCF ₃ ) 43-.

According to a second preferred variant of the invention, the onium salts (1) which can be used are described in numerous documents, in particular in patents US-A-4,026,705, US-A-4,032,673, US-A-4 069 056, US-A-4 136 102, US-A-4 173 476. Among these, the following cations will be particularly favored:

[(Φ-CH ₃ ) ₂ l] ⁺ [(C ₈ H ₁₇ -O-Φ) ₂ l] ⁺

[(C ₁₂ H ₂₅ -Φ) 2 l] ⁺ [(CH ₃ -Φ-I-Φ-C ₁₂ H ₂₅ ] ⁺ [(HO-CH ₂ -CH ₂ ) ₂ S-CH ₂ -Φ] ⁺ [ (C ₁₂ H25-CH (OH) -CH2-O-Φ) ₂ l] ⁺

[(HO-CH2-CH ₂ -O Φ) ₃ S] + [(HO-CH ₂ -CH ₂ -θΦ) 2-S-Φ-O-C8H-i7] ⁺ and [(CH ₃ -Φ-I -Φ-CH (CH ₃ ) ₂ ] ⁺ [(CH ₃ ) ₃ C-Φ-I-ΦC (CH ₃ ) ₃ ] ⁺

In agreement with these two preferred variants, mention may be made, as examples of photoinitiators of the onium borate type, of the following products:

[(C ₁₂ H ₂ 5-CH (OH) -CH2-O-Φ) ₂ l] ⁺ , [B (C ₆ F ₅ ) ₄ r [(C ₈ H ₁₇ -O-Φ) ₂ l] ⁺ , [B (C ₆ F ₅ ) ₄ ] -

[(CH ₃ ) ₃ C-Φ-I-ΦC (CH ₃ ) ₃ ] ⁺ , [B (C ₆ F ₅ ) ₄ ] -

[(C ₁₂ H25-Φ) 2l] ⁺ _> [B (C ₆ F ₅ ) 4] -

[(Φ-CH ₃ ) ₂ I] ⁺ , [B (C ₆ F ₅ ) ₄ ] -

[(Φ-CH ₃ ) ₂ l] ⁺ , [B (C ₆ F ₄ OCF ₃ ) ₄ ] - [CH ₃ -Φ-I-Φ-CH (CH ₃ ) ₂ ] ⁺ , [B (C ₆ F ₅ ) ₄ ] -

[(HO-CH ₂ -CH ₂ ) ₂ S-CH ₂ -Φ] ⁺ , [B (C ₆ F ₅ ) ₄ ] ^'

[CH3-Φ-I-Φ-CH (CH ₃ ) ₂ ] ⁺ , [B (C ₆ H ₃ (CF ₃ ) ₂ ) ₄ r and [(C ₁₂ H ₂₅ Φ) ₂ I] ⁺ , [B ( C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ] -

A second aspect of the present invention relates to a non-stick silicone / adhesive complex comprising at least one silicone coating applied to a first support and an adhesive coating applied to a second. support, characterized in that said silicone coating is derived from a mixture of polyorganosiloxane (s) (A) and (B) in the presence of a miscible photocell as defined above.

According to a first variant, the two supports are made of two separate materials, arranged so that the silicone coating of the first support is in contact with the adhesive coating of the second support. This embodiment is in particular illustrated by systems known as self-adhesive labels associated with a non-adherent support. In this particular case, the release force of the silicone / adhesive interface is exerted during the separation of the two supports.

In a second variant, the two supports are constituted respectively by each of the two faces of the same material. This second embodiment is in particular illustrated by the systems known as adhesive tapes. The non-stick coating, that is to say based on the silicone matrix and the adhesive coating are brought into contact during the winding of the support on itself. In this case, the release force is exerted at the silicone / adhesive interface under the effect of the separation of a lower face with an upper face of the material.

With regard to the adhesive coating, it can be very diverse in nature insofar as it is chemically compatible with the silicone coating.

In the context of the present invention, it can in particular be chosen from adhesives of the acrylic type, natural or synthetic gums and / or latex.

In general, the adhesive coatings deposited on the surface of a wide variety of materials so as to obtain labels, tapes or any other self-adhesive material derive from emulsions called pressure-sensitive adhesive emulsions (PSA). They give the material the ability to adhere to the surface of a support, without requiring activation other than low pressure. The monomers used to prepare the PSAs are selected according to their glass transition temperature, Tg, to give the polymers incorporating them the expected behavior in terms of adhesion and viscoelasticity. For this purpose, the monomers advantageously have a sufficiently low glass transition temperature, generally between -70 and -10 ° C and preferably is less than -30 C.

More specifically, these monomers are chosen from the group consisting

(meth) acrylic esters such as the esters of acrylic acid and of methacrylic acid with the hydrogenated or fluorinated CC ₁₂ alkanols, preferably CC ₈ , in particular methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, tert-butyl acrylate, hexyl acrylate, heptyl acrylate , octyl acrylate, iso-octyl acrylate, decyl acrylate, dodecyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, methacrylate d 'isobutyl;

- vinyl nitriles including more particularly those having 3 to 12 carbon atoms, such as in particular acrylonitrile and methacrylonitrile;

- vinyl esters of carboxylic acid such as vinyl acetate, vinyl versatate, vinyl propionate, - ethylenic unsaturated mono- and dicarboxylic acids such as acrylic acid, methacrylic acid, acid itaconic, maleic acid, fumaric acid and the mono- and di-alkyl esters of the mono- and dicarboxylic acids of the type mentioned with the alkanols preferably having 1 to 8 carbon atoms and their N-substituted derivatives, - the amides of unsaturated carboxylic acids such as acrylamide, methacrylamide, N-methylolacrylamide or methacrylamide, N-alkylacrylamides,

ethylenic monomers comprising a sulfonic acid group and its alkali or ammonium salts, for example vinylsulfonic acid, vinylbenzenesulfonic acid, alpha-acrylamido methylpropane-sulfonic acid, 2-sulfoethylene-methacrylate, - the unsaturated ethylenic monomers comprising a secondary, tertiary or quaternary amino group, or a heterocyclic group containing nitrogen such as for example vinylpyridines, vinylimidazole, aminoalkyl (meth) acrylates and (meth) acrylamides) aminoalkyl such as dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate, ditertiobutylaminoethyl acrylate or ditertiobutylaminoethyl methacrylate, dimethylaminomethyl-acrylamide or dimethylaminomethyl-methacrylamide,

- zwitterionic monomers such as, for example, sulfopropyl (dimethyl) aminopropyl acrylate, - ethylenic monomers carrying a sulfate group,

- ethylenic monomers carrying one or more phosphate and / or phosphonate function (s),

- and their mixtures.

Conventionally, PSAs are obtained by polymerization mainly of alkyl acrylate monomers which are generally present in an amount of 50 to about 99% and preferably in an amount of 80 to 99% by weight and of copolymerizable polar monomers such as for example acrylic acid, in smaller proportions.

A third aspect of the present invention relates to the use of type B polyorganosiloxane as described above for stabilizing the release forces of a silicone / adhesive complex as defined above by introduction of such a type B polyorganosiloxane in the curable composition based on type A silicone and photoinitiator according to the invention.

In the context of the present invention, a release force is generally obtained which is less than 20 g / cm, and more frequently a release force is less than 10 g / cm.

In general, the force required to peel off the non-stick silicone coating from the adhesive changes at most by a factor of less than 4 and more frequently less than 2, at the end of the 7-day aging test at 70 ° C, representative of a 6-month aging.

This release force also does not change, and at most changes by a factor of less than 2, regardless of the pressure exerted between the adhesive and the non-stick silicone coating.

The following Examples and Tests are given by way of illustration. They make it possible in particular to better understand the invention and to highlight some of its advantages and to illustrate some of its variant embodiments.

Products used.

The photoinitiator used is in 18% solution in isopropanol and corresponds to the formula:

The silicone (A) used in combination with the silicone of type (B) has the average formula below where a = 80 and b = 7:

The silicone (B) is of average formula below where a = 180

Examples 1 to 4: preparation of photocrosslinkable compositions.

The compositions are prepared from a mixture of 100 parts by weight of a mixture of polymers (A) (300 cps) and (B) (1200 cps) to which 2.5 parts by weight of a solution of the photoinitiator are added. 18% isopropanol.

Tests.

A. Non-stick silicone coatings obtained from compositions 1 to 4.

These compositions are light-cured after application on polyester film of the Mylar® type.

Each composition is applied using a manual coating machine (Euclide Tool and Machine); the deposit made is of the order of 1 g / m ² .

The applied composition is then exposed under UN irradiation. at a running speed of 100 m / min and in the presence of a mercury arc lamp with a power of 120W / cm (company IST)

B .. Complex non-stick silicone coating / Adhesive.

Each non-stick silicone coating is then brought into contact with an adhesive tape of the Beiersdorf TESA®4970 type and then tested according to the procedures described below. C. Procedures.

The release forces of the various coating / adhesive complexes obtained are measured: (i) initially.

(ii) after storage for 20 h at 20 ° C according to the standardized FINAT3 test under a force of 70 g / cm with a peeling speed of 300 mm / min.

(iii) after 1 day at 70 ° C simulating an aging of 1 to 3 months at 20 ° C under pressure conditions of 70g / cm (FINAT10). (iv) and after simulating an aging of 6 months of the coating / adhesive complexes for 7 days at 70 ° C.

P. Results.

Claims

1. A coating composition based on silicone, curable under irradiation, characterized in that it comprises:

(a) at least one liquid polyorganosiloxane A having a viscosity of approximately 10 to 10,000 mPa.s at 25 ° C and carrying a crosslinkable and / or polymerizable function Fa on at least one M and or T unit, and / or at least one crosslinkable and / or polymerizable function Fa on at least one unit D,

(b) at least one linear liquid polyorganosiloxane B having a viscosity of approximately 10 to 10,000 mPa.s at 25 ° C and carrying at least 2 crosslinkable and / or polymerizable Fb functions on at least one M unit,

2. Composition according to the preceding claim, characterized in that the pyorganosiloxane A comprises at least one crosslinkable and / or polymerizable function Fa on the units D and / or T,

3. Composition according to any one of the preceding claims, characterized in that the function Fa is chosen from the group consisting of epoxy, and / or alkenylether and / or oxetane and / or dioxolane functions.

4. Composition according to any one of the preceding claims, characterized in that the polyorganosiloxane A is linear and consists of units of formula (I) and terminated with units of formula (II), or is cyclic and consists of units of formula ( I) shown below: in which :

(1) the symbols R, similar or different, represent:

(ii) a cycloalkyl radical containing between 5 and 8 cyclic carbon atoms, optionally substituted,

(iii) an aryl radical containing between 6 and 12 carbon atoms which can be substituted, preferably phenyl or dichlorophenyl,

(iv) an aralkyl part having an alkyl part containing between 5 and 14 carbon atoms and an aryl part containing between 6 and 12 carbon atoms, optionally substituted on the aryl part by halogens, alkyls and / or alkoxyls containing 1 with 3 carbon atoms,

(vi) a hydrogen radical,

(2) the symbols X are similar or different and represent:

(i) an R group,

(ii) and / or a crosslinkable and / or polymerizable organofunctional group Fa, preferably an epoxyfunctional, oxetanefunctional, dioxolanefunctional and / or alkenyl etherfunctional group, linked to the silicon of the polyorganosiloxane via a divalent radical containing from 2 to 20 atoms of carbon and possibly containing at least one heteroatom, preferably oxygen,

(iii) with at least one of the symbols Fa in one of the patterns (I).

5. Composition according to any one of the preceding claims, characterized in that the Fb function is chosen from the group consisting of epoxy, and / or alkenylether and / or oxetane and / or dioxolane functions.

6. Composition according to any one of the preceding claims, characterized in that the polyorganosiloxane B consists of units of formula (III) and terminated by units of formula (IV) represented below:

in which :

(1 ") the symbols R, similar or different, represent:

(iii) an aryl radical containing between 6 and 12 carbon atoms which can be substituted, preferably phenyl or dichlorophenyl, (iv) an aralkyl part having an alkyl part containing between 5 and

14 carbon atoms and an aryl part containing between 6 and 12 carbon atoms, optionally substituted on the aryl part by halogens, alkyls and / or alkoxyls containing 1 to 3 carbon atoms,

(vi) and a hydrogen radical;

(2 ') the symbols Y are similar or different and represent:

(i) an R group,

(ii) and or a crosslinkable and / or polymerizable organofunctional group Go, preferably an epoxyfunctional, oxetanefunctional, dioxolanefunctional and / or alkenyl etherfunctional group, linked to the silicon of the polyorganosiloxane via a divalent radical containing from 2 to 20 atoms of carbon and possibly containing at least one heteroatom, preferably oxygen,

(iii) with at least one of the symbols Fb, and preferably two symbols Fb in one of the patterns (IV).

7. Composition according to any one of the preceding claims, characterized in that the polyorganosiloxane B carries at least 2 units

M with at least 2 Fb functions.

8. Composition according to any one of the preceding claims, characterized in that the polyorganosiloxane B also carries at least one Fb group as defined in claim 6 on at least one unit D.

9. Composition according to any one of the preceding claims, characterized in that the onium borate is chosen from mi the onium borates of an element from groups 15 to 17 of the periodic table or of an organometallic complex of an element from groups 4 to 10 of the periodic classification of which:

M the cationic entity of borate is selected from:

(1 ") the onium salts of formula (I):

[(R ¹ ) n - A - (R2) _m ] + (|) formula in which:

R1 represents a carbocyclic or heterocyclic Cβ-C2o aryl radical, said heterocyclic radical possibly containing nitrogen or sulfur as heteroelements,

• R ^ represents R ^" ! Or a linear or branched C1-C30 alkyl or alkenyl radical; said radicals R1 and R ² being optionally substituted by a C-1-C25 alkoxy group, C-1-C25 alkyl, nitro , chloro, bromo, cyano, carboxy, ester or mercapto, • n is an integer ranging from 1 to v + 1, v being the valence of the element A,

• m is an integer ranging from 0 to v - 1 with n + m = v + 1,

(2 ") the oxoisothiochromanium salts, and in particular the sulfonium salt of 2-ethyl-4-oxoisothiochromanium or of 2-dodecyl-4-oxoisothio-chromanium, B and the anionic borate entity has the formula [BX ' _a R _,] ~ in which:

- a and b are integers ranging for a from 0 to 3 and for b from 1 to 4 with a + b = 4,

- the symbols X 'represent:

* a halogen atom (chlorine, fluorine) with a = 0 to 3, * an OH function with a = 0 to 2,

- the symbols R ³ are identical or different and represent:

> a phenyl radical substituted by at least one electron-withdrawing group such as for example OCF3, CF3, NO2, CN, and / or by at least 2 halogen atoms (especially fluorine), and this when the cationic entity is an onium an element from groups 15 to 17, > a phenyl radical substituted by at least one element or an electron-withdrawing group, in particular a halogen atom (especially fluorine), CF3, OCF3, NO2, CN, and this when the cationic entity is an organometallic complex of an element of the groups 4 to 10

10. Non-stick coating capable of being obtained by crosslinking and / or polymerization from compositions according to any one of the preceding claims.

11. Non-stick silicone / adhesive complex comprising at least one silicone coating applied to a first support and an adhesive coating applied to a second support, characterized in that said silicone coating is derived from a composition according to any one of claims 1 at 9.

12. Use of type B polyorganosiloxane (s) as defined in any one of claims 1 and 5 to 8 for the stabilization of the release forces of a silicone / adhesive complex according to claim

11.