EP1406972A1

EP1406972A1 - Release regulating silicone system and use thereof for preparing curable release compositions

Info

Publication number: EP1406972A1
Application number: EP02751240A
Authority: EP
Inventors: Didier Dhaler; John White
Original assignee: Rhodia Chimie SAS
Current assignee: Elkem Silicones France SAS
Priority date: 2001-06-07
Filing date: 2002-06-04
Publication date: 2004-04-14
Also published as: AU2002344382A1; JP2005509046A; US20050020764A1; WO2002098972A8; WO2002098972A1; FR2825713A1; CA2447104A1; FR2825713B1; US20070191553A1

Abstract

The invention concerns a novel release regulating silicone composition, and its use for preparing curable release compositions (Si-H/Si-Vi), adapted to be applied on substrates so as to facilitate removal of adhesive materials reversibly glued on said substrates. The invention aims at providing adhesion modifiers highly efficient in terms of regulating power and without negative effect on the instantaneous tackiness of adhesive materials laminated on the release silicone coating. Therefor the invention provides a release regulating system based on: 96 to 85 parts by weight of at least a reactive polyorganosiloxane resin (A) of the type: MDViQ, MDViT, MMHexenylQ, or MMAllyloxypropylQ; 4 to 15 parts by weight of at least a non-reactive resin (B) of the type: MD'Q, MDD'Q, MDT', MQ or MDQ. The invention also concerns the use of a regulating system for preparing release compositions containing a linear polyorganosiloxane, said regulating system, a hydrosilylation inhibitor, a linear crosslinking polyorganohalogenosiloxane and a hydrosilylation catalyst.

Description

ADHESION MODULATOR SILICONE SYSTEM AND ITS USE FOR THE PREPARATION OF NON-ADHERENT COMPOSITIONS

CURABLE

The subject of the present invention is a new silicone adhesion modulating system, and its use for the preparation of non-stick silicone compositions, curable and applicable on supports, so as to facilitate the removal of adhesive materials reversibly laminated on these supports. .

It is known (French Patent No. 2,450,642) to use solutions of polymethylvinylsiloxane resin in a vinylated silicone oil added with a methylhydrogenopolysiloxane crosslinker soluble in the resin solutions, an inhibitor and a reaction catalyst. addition, to coat supports such as paper, thin sheets of aluminum, etc. in order to allow controlled detachment, from said supports, of pressure-sensitive adhesive materials ("Pressure Sensitive Adhesive: PSA"), such as acrylic adhesives. This type of composition has the drawback of being only of average effectiveness with respect to other adhesives, in particular those of the styrene-butadiene rubber type.

It has also been proposed (US Pat. No. 3,772,247) to treat paper supports using compositions containing polyorgano-hydrogen siloxane resins as adhesion modulators, to allow controlled detachment of rubber-based adhesives. Such compositions do not perform well with regard to acrylic adhesives.

European patent application EP-A-0 601 938 discloses an adhesion modulator system comprising a mixture based on: a solution at 50% by weight in xylene, of a polymethylvinylsiloxane resin ^ comprising:

• 36 mol% of units (M) Me3 Si O A.

• 6 mol% of units (D ^Vi ) Me Vi Si O

• 58 mol% of units (Q) If Oz a solution at 30% by weight in toluene, of a polymethylhydrogenosiloxane B resin comprising:

• 39 mol% of units (M) Me3 Si O *

• 3.5 mol% of units (D ') Me H Si O

• 56.5 mol% of units (Q) Si O2 in the proportions corresponding to an A / B weight ratio of 50/50 in dry products (the two resins being in solid form in the dry state); - polydimethylvinylsiloxαne Ç oil having a viscosity of 200 mPa.s. at 25 ° C. and containing 1 mol% of SiVi functions in the form of Me2 Vi Si O / 2 and Me Vi Si O units, C being in an amount such that the weight ratio A + B / Ç corresponds to 45/55 in dry products ; > - 0.15 part by weight of ethynylcyclohexanol (crosslinking inhibitor) per 100 parts by weight of silicone polymers, xylene and toluene being removed under vacuum at 100 ° C. The modulator thus composed has a viscosity of the order of 4000 mPa.s. at 25 ° C. Although this modulator already constitutes progress compared to the existing one, it nevertheless remains perfectible as regards the increase in the modulating power, without reducing instantaneous adhesion without pressure - the "tack" - glue coating. This point is particularly crucial in certain applications of silicone anti-adhesives, such as that of adhesive labels for bottles, which must be adapted to the current dizzying rates of bottling chains.

The modulating power is comparable to the ability to increase the release force of the non-stick silicone film with respect to the adhesive coating, with which it is associated.

In such a state of the art, one of the essential objectives of the present invention is to propose a new adhesion modulating system for silicone compositions, non-stick, crosslinkable (in particular by Si-H / Si Vi polyaddition), said system having to be an improvement of the modulator according to EP-A-0 601 938.

Another essential objective of the invention is to provide a new silicone adhesion modulating system which can be used for the preparation of curable compositions (in particular by Si-H / SiVi polyaddition), and having a high modulating power, without prejudice for the tack of the glue.

Another essential objective of the invention is to provide a new silicone adhesion modulating system which can be used for the preparation of curable compositions (in particular by Si-H / SiVi polyaddition), constituting an efficient tool for the film formulator. non-stick, that is to say allowing it to adjust, over a wide range, the release force of the non-stick films, for a varied and extensive range of supports and adhesives.

Another essential objective of the invention is to provide a new silicone adhesion modulating system which can be used for the preparation of curable compositions (in particular by Si-H / SiVi polyaddition), allowing the controlled detachment of any type of adhesive, acrylic or rubbers, of various supports (paper, glass, plastic, metal ...). Another essential objective of the invention is to provide a new silicone adhesion modulator system which can be used for the preparation of curable compositions (in particular by Si-H / SiVi polyaddition), this modulator allowing the complex formed (" laminate ") by the support coated with the cured silicone composition and the adhesive system exhibits excellent stability as regards its adhesion performance over time (" stability of release performance ").

Another essential objective of the invention is to provide a new silicone adhesion modulator system which can be used for the preparation of curable compositions (in particular by Si-H / SiVi polyaddition), this modulator being simple to prepare and to use. , and economical.

Another essential objective of the invention is to propose silicone compositions, non-stick, crosslinkable (in particular by polyaddition Si-H / SiVi), comprising a new adhesion modulator system with high modulating power, without effect on the "tack "of the adhesive or of the other adhesion properties, these compositions having to be inexpensive, easy to apply on any type of support, and crosslinked in non-stick, cohesive and effective films.

These objectives, among others, are achieved by the invention, which relates first of all, to an adhesion modulator system based on:

• (A) at least one polyorganosiloxane resin in solid form in the dry state, and consisting of at least two different types of siloxy units 3S1O1 / 2 (unit M) and Siθ2 (unit Q) and / or RS1O3 / 2 (motif T), and optionally of 2S1O motifs (motif D), the radicals R being identical or different and representing organic radicals, with a ratio number of units (M) / number of units (Q) and / or (T) 0.6-1, the number of possible units (D) being 0.5-10 per 100 moles of resin;

• (B) at least one polyorganosiloxane resin in solid form in the dry state, and consisting of at least two different types of siloxy units' 3SiOι / 2 (unit M) and Siθ2 (unit Q) and / or 'Siθ3 2 (unit T), and optionally of units R'2SiO (unit D), the radicals R' being similar or different and representing organic radicals, with a ratio number of units (M) / number of units (Q ) and / or (T) of 0.6-1, the number of units (D) possible being 0.5-10 per 100 moles of resin;

• (C) and at least one solvent or at least one diluent of the mixture of resins (A) and (B); characterized in that:

• the resin (A) is reactive and represents an amount in parts by weight, from 99 to 75, preferably from 97 to 80, and more preferably still from 96 to 85; • The resin (B) is non-reactive and represents an amount in parts by weight, from 1 to 25, preferably from 3 to 20, and more preferably still from 4 to 15 parts by weight.

These modulators are very effective in terms of modulating power and very reactive. They do not disturb the performance of the adhesive, and in particular do not harm its "tack". They are inexpensive and suitable for all types of substrates and adhesives.

It is to the credit of the inventors to have understood the importance of the non-reactive B species of "MQ" type resins, in the quest for an improved and efficient modulator. In addition, the inventors have been able to select judiciously and advantageously, the right proportions between the non-reactive species B of "MQ" type resins and the reactive species A of MQ resins.

This notion of non-reactive "MQ" type silicone resin B is fundamental in the context of the invention. Thus, a so-called "non-reactive" silicone resin is said to have no reactive functions capable of allowing it to bind with the other species of resins present and thus to integrate the crosslinking network. Resins B are therefore not incorporated into the crosslinking network by covalent chemical bonds. They can then be extracted from the network by entrainment with an appropriate solvent. Hence it follows that the B resins can also be qualified by the term "extractable". The extractable or non-extractable nature of a silicone resin of the "MQ" type is determined using a test, carried out on the crosslinked coating, derived from a silicone composition including the modulator. This test is carried out either immediately after crosslinking ("in-line"), or a few days after ("off-line"). This test consists of immersing the silicone coating in toluene to extract all the silicone species not integrated into the silicone network. The extracted silicone is then dosed in solution in toluene, by atomic adsorption.

Within the meaning of the invention, the term "MQ resin", taken in its general meaning, designates any resin B exclusively or in particular, siloxyl units "M = R ₃ SiOι _{/ 2} " and "Q = SiO ₂ ".

Within the meaning of the invention, a resin B is considered to be non-reactive or extractable, since: The quantity of B is greater than or equal to 50% by weight relative to the mass of B introduced initially,

• and B is found in the total extractables.

Formulators of non-stick, silicone, crosslinkable compositions

(in particular by Si-H / SiVi polyaddition), have, with the modulator system according to the invention, a reliable and efficient tool for adjusting the release force.

The nature of the radicals R, R ′ of the resins A and B is chosen so as to make them, respectively, reactive and non-reactive.

In the preferred embodiment of the invention, which relates to modulators for silicone compositions crosslinkable by polyaddition - eg POS Si-alkenyl (for example Vi = vinyl) and POS Si-H-, the modulator system is characterized in that : • in the resin (A), the radicals R independently and at least partially represent: Φ alkyl groups - preferably C \ -C \ -, or (cyclo) alkyl - preferably C3-C18-,

Φ (cyclo) alkyl groups - preferably C3-C18-, Φ alkenyl groups C2-C20- preferably C2-C12,

Φ (cyclo) alkenyl groups at C3-C20, preferably at

C4-C12, Φ or alkenyl (C3-C9) oxyalkylene (C2-C4) groups, - preferably at least 80 mol% of the radicals R representing a methyl group, ^• at least 0.1 mol%, preferably 0 , 5 to 5 mol% of the radicals R representing an alkenyl or alkenyloxyalkylene group bonded to silicon ("Si-alkenyl"), the vinyl radical (Vi) being particularly preferred as R = alkenyl; • in the resin (B), the radicals R 'independently and at least partially represent: Φ hydrogen,

Φ alkyl groups - preferably C \ -C \ Q-, or (cyclo) alkyl - preferably C3-C18- _* Φ or (cyclo) alkyl groups - preferably C3-C18-, preferably minus 807o molar of the radicals R ′ representing a methyl group, • the resin (A) containing less than 2.5% (preferably less than 0.5%) molar of silanol functions;

• the resin (B) containing less than 10% (preferably less than 2.5%) molar, of silanol functions.

Thus, the resins (A) are preferably resins with "Si-alkenyl" functions, in particular vinyl resins, which are well known to those skilled in the art. In these resins (A), the groups R = alkenyl or alkenyloxy can be located on the units

(M), (D) or (T). These resins (A) can be prepared, for example, according to the process described in US Pat. No. 2,676,182.

The level of silanol groups of these resins can be controlled using a treatment well known to those skilled in the art. This treatment involves a silazane, which allows the rate of remaining silanol functions to be reduced to less than 0.3% by weight. A certain number of these resins are commercially available, most often in the form of solutions, for example at 40-70% in a solvent such as toluene or xylene.

In this preferred embodiment of the invention, the reactive resin (A) is a resin which comprises Si-Vi units and which is chosen from the group comprising: MD ^ 'Q where the vinyl groups are included in the units ( D), - MD ^ 'TQ WHERE the vinyl groups are included in the patterns (D),> - MM ^' Q where the vinyl groups are included in part of the patterns (M), MM ^ 'TQ where the vinyl groups are included in a part of the units (M), ^ MD ^ 'T where the vinyl groups are included in the units (D), ^ MM ^ ^exen y'Q (optionally comprising units T carrying or not an alkenyl group ) where the hexenyl groups are included in a part of the units (M), ^ MM ^ "y ' ^oχ yP ^ro P ^v ' Q (optionally comprising T units carrying or not an alkenyl group) where the allyloxypropyl groups are included in a part of the patterns (M), - all of the associations of each of the above resins with patterns

M ^0H and / or D ^0H and / or T ^0H . > ^• and their mixtures.

The resin (B) is a non-reactive resin, which can nevertheless have functions corresponding to the same definition as those which are reactive in the resin (A) and / or in the constituents of the silicone composition including the modulator, whereas these functions are not reactive in resins (B). In particular, the resins (B) can be MQ resins, optionally comprising non-reactive "Si-H" and / or "Si-OH" functions. These resins (B) with "Si-H" functions can be in particular those described in US Pat. No. 3,772,247, in which the non-reactive hydrogen atoms are located in the chain; a number of these resins are commercially available.

In this preferred embodiment of the invention, the adhesion modulator system is characterized in that the non-reactive resin (B) is chosen from the group comprising: MD'Q where the hydrogen atoms bonded to silicon are included in the units (D), MD'TQ where the hydrogen atoms linked to silicon are included in the units (D), ^• MDD'Q where the hydrogen atoms linked to silicon are included in the units (D), MDD'TQ where the hydrogen atoms bonded to silicon are included in the units (D), MDT 'where the hydrogen atoms bonded to the silicon are included in the units (T). > - MDD'T 'where the hydrogen atoms bonded to silicon are included in the units (T) and (D), MDD'TT' where the hydrogen atoms bonded to the silicon are included in the units (T) and (D),

^ MQ, ^ MDQ, MDTQ,

> ^• all of the associations of each of the above resins with M ^OH and / or D ^0H and / or T ^{0H units} , and their mixtures.

As indicated above, the resins (B), and to a lesser extent the resins (A), can comprise silanol groups carried by the units M and / or D and / or T. The OH of the silanols can be OH residuals from the synthesis of MQ resins.

With regard to the solvents or diluents (C) of these solid resins, the following can be used: - () conventional hydrocarbon solvents of silicone resins, aromatic type solvents (xylene, toluene), saturated aliphatic (hexane, heptane, white spirit, tetrahydrofuran, diethyl ether), chlorinated solvents (methylene chloride, perchlorethylene). They are generally used in an amount corresponding to

50-70 parts by weight per 30-50 parts by weight of solid resins

(AWB).

- (2) so-called "reactive" solvents such as:

> (a) liquid polyorganosiloxane resins, the organic radicals of which are C 1 -C 20 alkyl or cycloalkyl groups, C 2 -C 20 alkenyl groups, preferably C 2 -C 12 alkenyl groups, having a number of units (M) / number ratio of units (Q) and / or (T) on the order of 1 to 4 and optionally from 1 to 5 units (D) per 100 moles of liquid resin, and containing from 0.5 to 5 mol% of linked alkenyl functions silicon ("Si alkenyl") or hydrogen atoms bonded to silicon ("SiH"); these resins have a viscosity at 25 ° C of less than 100 mPas., preferably of the order of 2 to 50 mPas. These liquid resins are known products; they are in particular described in patent US-A-4,707,531 and European application EP-A-389138.

> And / or (b) polyorganosiloxanes fluid oils, whose organic radicals are alkyl or cycloalkyl, Cι-IC8 _# C2-C2Q, alkenyl (C3-C9) oxyalkylene (C2-C4), containing oils 0 , 2 to 5 mol% of alkenyl or alkenyloxyalkylene functions linked to silicon, at the chain end (s) or in the chain, said oils having a viscosity of less than 200 mPa. s.

> And / or (b ') of oil polyorganosiloxane fluids, carrier of hydrogen and substituents which the organic radicals are alkyl or cycloalkyl C \ -C \ Q _I C2-C20, alkenyl (C3-C9) oxyalkylene ( C2-C4), oils containing from 0.2 to 5 mol% of hydrogen substituents linked to silicon, at the chain end (s) or in the chain, said oils having a viscosity of less than 200 Pa. S.

> and / or (c) olefinically unsaturated hydrocarbons such as 14-C18 olefins, dibutyl maleate, decylvinyl ether, dodecylvinyl ether, camphene, meta-bis isopropenylbenzene ... The so-called "reactive" solvents are generally used in an amount corresponding to 20-50 parts by weight per 80-50 parts by weight of solid resins (A) + (B). - (3) aqueous emulsions of nonionic surfactants (polyvinyl alcohol, alkylphenolpolyethoxylates, oxyethylenated ethers of fatty alcohols

...) generally containing around l-3%> by weight of surfactant.

They are generally used at a rate of 40-70 parts by weight for 60-30 parts by weight of solid resins (A) + (B).

The adhesion modulator system of the invention can therefore be in particular in the form of a solution or an emulsion. It can be obtained by mixing constituents (A), (B) and (C), as appropriate: o until the solid resins (A) and (B) are dissolved or diluted in the solvent or diluent (C ): (1) ά (2}, o until the solid resins (A) and (B) are emulsified in the solvent or diluent (C): (3). The present invention also relates to silicone compositions. , curable, non-stick containing the modulator system according to the invention Preferably, these compositions are of the type of those crosslinkable by polyaddition (Si-alkenyl, egVi / Si-H).

Thus, in the preferred mode of application of the invention, the target is compositions curable by polyaddition, non-sticking and containing:

- at least one (preferably 100-x parts by weight) linear polydiorganosiloxane (D) blocked by triorganosiloxane end groups, said organic radicals being C 1 -C 20 alkyl or cycloalkyl groups, C 2 -C 20 alkenyl, preferably C2-C12, alkenyl (C3-C9) oxyalkylene (C2-C), at least 80 mol% of said radicals being a methyl group, at least 0.1 mol%, preferably from 0.5 to 5 mol% of said organic radicals being identical or different alkenyl or alkenyloxyalkylene groups linked directly to silicon ("Si alkenyl");

- at least one (preferably x parts by weight of) modulator system based on the constituents (A), (B) and (C) as defined above, the value of x can preferably range from 0.1 to 100, preferably from 5 to 95 and very particularly from 10 to 90;

- at least one hydrosilylation inhibiting agent; - at least one linear polyorganohydrogensiloxane crosslinking agent (E) containing 1.6 to 0.5 mol% of hydrogen atoms directly attached to silicon ("SiH") at the chain end (s) and / or in the chain, the identical or different organic radicals being Cι-CQ alkyl groups, at least 807o molar of said organic radicals being methyl groups, the amount of crosslinking agent being such that the ratio number of moles of "SiH" originating from non-reactive resin (B), "reactive" solvent (C) and crosslinking agent (E) / number of moles of "Si alkenyl" from reactive resin (A), "reactive" solvent ( C) and blocked linear polydiorganosiloxane (D), ie greater than 1, preferably of the order of 1.1 to 2.5;

- an effective amount of a hydrosilylation catalyst.

The linear polydiorganosiloxane blocked with "Si-alkenyl" functions (D) has a viscosity of at least 50 mPa.s., generally of the order of 100 to 1000 mPa.s. ; it may contain some traces of non-linear siloxane units (T) and / or (Q). Vinyl oils are commercial products usually used to prepare non-stick curable compositions (US Pat. No. 4,623,700).

Oils with heavier alkenyl or alkenyloxyalkylene groups are described in particular in patents EP-B-0 219 720 and EP-A-0 454 130.

The crosslinking agent with "Si-H" functions (E) has a viscosity of less than 200 mPa.s., preferably of the order of 5 to 150 mPa.s. Examples of these crosslinking agents are given in US-A-4,623,700 and European patent EP-B-0 219 720.

Among the catalysts that may be present, there may be mentioned the well-known derivatives and complexes of metals such as platinum, rhodium, ruthenium, etc. Examples of catalysts are given in US Patents 3,159,601; 3,159,662; 3,220,972; 3,715,334; 3,775,452; 3,814,730; 3,296,291; 3,928,629; French FR-A-1 313 846; 1,480,409. They are generally used in an amount of the order of 5 to 500 parts by weight expressed as metal per million parts by weight of reactive silicone polymers.

The hydrosilylation inhibiting agent is present in an amount such that it inhibits the action of the catalyst at room temperature, this inhibiting action ceasing during the crosslinking treatment at high temperature; this amount is generally of the order of 0.01 to 1 part by weight. In particular, in the event that the hydrosilylation inhibiting agent is EthynylCycloHexanol, it is present in an amount of 0.1 to 0.25 part by weight per 100 parts of the total weight of silicone. Among the inhibitors, mention may be made of dialkyldicarboxylates (US Pat. Nos. 4,256,870; 4,476,166); dialkylacetylenedicarboxylates (US-A-4,347,346); acetylenic alcohols (US Patents-3,989,866; 4,336,364; 3,445,420) ...

According to a preferred characteristic of the invention, the concentration of [POS (B)], in% by weight on a dry basis relative to the total mass of the composition, is defined as follows:

* [POS (B)] ≤ 20

* preferably [POS (B)] <15 * and more preferably still [POS (B)] ≤ 10.

It has indeed been observed, in the context of the invention, that the performance of the modulator system is optimized, provided that care is taken to introduce it into the non-stick silicone composition, in such a quantity that B does not represent more than 20% by dry weight, relative to the total mass of the composition.

According to a variant, the modulating systems and the non-stick silicone compositions which contain them, are not organic solutions, but emulsions. In this case, as indicated above, the compound (C) (S) comprises water and nonionic surfactants (polyvinyl alcohol, alkylphenolpolyethoxylates, oxyethylenated ethers of fatty alcohols ...) The system emulsion modulator generally contains around 1-3% by weight of surfactant.

Said curable compositions are fluid at normal temperature; their viscosity is generally of the order of 50 to 500 mPa.s. at 25 ° C.

They can be applied using devices used on industrial paper coating machines such as a five-roller coating head, air knife systems, equalizing bar on flexible supports or materials, then hardened by circulation in tunnel ovens heated to 70-200 ° C; the passage time in these ovens is a function of the temperature; this is generally on the order of 5 to 15 seconds at a temperature on the order of 100 ° C. and on the order of 1.5 to 3 seconds at a temperature on the order of 180 ° C.

Said compositions can be deposited on any flexible material or substrate such as various types of paper (supercalendered, coated, etc.), cardboards, sheets of cellulose, metal sheets, plastic films (polyester, polyethylene, polypropylene ...) ....

The quantities of compositions deposited are of the order of 0.5 to 2 g per m2 of surface to be treated, which corresponds to the deposition of layers of the order of 0.5 to 2 μm. The materials or supports thus coated can subsequently be brought into contact with any adhesive materials, rubber, acrylic or other, sensitive to pressure. The adhesive material is then easily detachable from said support or material.

The following examples are given for information only and cannot be considered as limiting the scope and spirit of the invention.

EXAMPLES: Example 1:

I. PRODUCTS IMPLEMENTED

- Al resin MM ^V 'Q purchased from Archi ica of ref MQV6 - Bl Rhodia® resin of structure MD'Q comprising 39 molar of patterns M (Me3SiOl / 2), 3.5 mol% of patterns D' (MeHSiO) and 56.5% Q (SiO2) pattern molar

Thinner Cl: PDMS vinyl oil with vinyl functions in alpha omega (2.8 meq mol / lOOg) having a viscosity of 60,000 cps at 25 ° C

- C2 thinner (tetradecene).

These resins are formulated as modulators as described in Table 1 below. 3 modulators were formulated, the first containing only resin Al = MM ^V, Q the second by replacing

5% of Al = MM ^Vi Q with Bl = MD'Q and the last with 10% of Bl = MD'Q. This Bl = MD'Q resin is non-reactive

II. FORMULATION OF MODULATORS TABLE 1

These modulators were then incorporated into a formulation without standard thermal solvent, then coated on the Rotomec brand coating pilot. This pilot includes a coating machine with a 5-cylinder coating head, as well as a crosslinking oven.

III. NON-STICK SILICONE COATING COMPOSITIONS:

* vinyl oil D: vinyl PDMS oil in a, ω with 0.022 mol / 100 g of Vi. This oil contains 0.15% of ECH inhibitor.

* crosslinker E: A mixture of hydrogenated PDMS oils commonly known as crosslinker of structure MD'DM, containing 1.33% of hydrogen and having a viscosity of 30 cps.

* a karstedt Pt catalyst containing 2000 ppm of Pt. IV. OPERATING CONDITIONS ON THE ROTOMEC PILOT:

Speed: lOOm / min

Oven: 150 ° C to have 128 ° C on the paper substrate. Deposit density: 1.25-1.35g / m ²

Substrate: 9564 glassine Ahlstrom (yellow)

V. TESTS IMPLEMENTED:

- Weight of the silicone coating: The silicon atoms of the coating are excited using a radioactive source or a fluorescent tube X and the intensity X re emitted by the coating is measured. By means of a calibration, the weight of the silicone coating is thus determined. The apparatus used has for reference Lab X1000 marketed by the company Oxford.

- Extractables rate (at the exit of the coating machine: "in-line" / 4 days after crosslinking: "off-line"): the test consists of immersing the coating in toluene and then assaying by gas phase chromatography ( CPG) with infiltration by infrared spectroscopy

(IR), the siloxyl units Q (therefore the resin "MQ") having been transferred to the solvent. By means of a calibration, the rate of silicone extractable from the coating is accessed. Two measurements can be carried out, either on a coating leaving the coating machine ("in line") or on a coating having been stored for 4 days at 23 ° C / 50% relative humidity ("off line" application ).

- Crosslinking: we qualify the level of polymerization of the coating at the outlet of the coating machine through a number of business tests: "smear" where we qualify the oily nature of the surface and "rub off" which characterizes the attachment to the support.

- Peel strength: the test used corresponds to the standards

Finish n ° 3 and 10 of edition n ° 5 of 1999. This test is carried out 4 days after crosslinking ("off-line") with adhesive tapes sold under the brand Tesa® 7475 at 23 ° C (acrylic base), Tesa® 7476 at 70 ° C (rubber base).

Control of instant adhesion performance without "tack" pressure of the PSA after contact with the silicone coating according to standard No. 9 of Finat edition No. 5 of 1999.

VI. RESULTS

TABLE 3

It is clearly noted that the resin Bl = MD'Q increases the modulation levels with the two adhesives used tesa® 7475 and 7476. The levels of extractables are also slightly higher, the resin Bl = MD'Q is not linked to the network and is therefore included in the extractables. There is no impact on the "tack" of pressure sensitive adhesives "PSA" (pressure sensitive adhesive). The extracts of compositions 1 and 3 were analyzed by gas chromatography (GC) / infrared spectroscopy (IR).

The appended figure gives the curves obtained in CPG with IR filtration corresponding to the siloxyl units Q (arbitrary units), in compositions 1 and 3, as a function of time (s) of CPG.

In view of the curves of the single appended figure, it can be seen that the composition 3 comprises Q motifs in significant quantity (peak at 0.60 ≈), while composition 1 contains practically none (peak at 0.10 ≈ ). This means that composition 3, which contains modulator (formulation 3) according to the invention, comprises extractable POS-B- resin (non-reactive) MD'Q. The non-integration of the MD'Q resin in the coating based on crosslinked composition 3 is confirmed.

Example 2:

Study of a modulator containing a mixed resin Al = MM ^Vi Q / Bl = MD'Q (90/10) with a competing modulator containing only one MM ^V 'Q resin (ROTOMEC TRIAL. Tests with different modulator rates.

I. Formulation of Modulators:

The formulation of the modulator according to the invention is as follows:

• 70% MQ resin (90% Al = MM ^vi Q / 10% Bl = MD'Q) see example 1. • 10% diluent C3 = vinyl oil in a, ω containing 5.75 meq mole of vinyls / 100g.

• 20% diluent C2 = tetradecene.

The performance of the modulator according to the invention is compared with that of a commercial product containing exclusively a resin A = MM ^V 'Q (70% resin A

= MM ^Vi Q / 12% vinyl oil in a, ω containing 5.75 meq mole of vinyls / 100g / 18% of dodecene diluent).

These two modulators are formulated as described in table 4 below and then coated on Ahlstrom glassine 9564 paper using the Rotomec coating pilot. TABLE 4

a vinyl oil Dl: vinyl oil in a, ω with 0.022mole / 100g of Vi, this oil contains 0.15% of inhibitor Ethynylcyclohexanol ECH.

Crosslinker El: a mixture of hydrogenated PDMS oils commonly called crosslinker of structure MD'DM containing 1.33% of hydrogen and having a viscosity of 30 cps.

A karstedt Pt catalyst containing 2000ppm of Pt

II. Coating / crosslinking conditions:

speed: 100m / min oven: 150 ° C to have 128 ° C on paper deposition rate: 1.25-1.35g / m ² substrate: 9564 glassine Ahlstrom (yellow)

III. Coating evaluation tests:

Weight of the silicone coating: The silicon atoms of the coating are excited using a radioactive source or a fluorescent tube X and the intensity X re-emitted by the coating is measured. By means of a calibration, the weight of the silicone coating is thus determined. The apparatus used has for reference Lab X1000 marketed by the company Oxford.

- Peel strength: the test used corresponds to Finat standards n ° 3 and 10 of edition n ° 5 of 1999. This test is performed 4 days after crosslinking ("off-line") with adhesive tapes sold under the brand Tesa® 7475 at 23 ° C (acrylic base), Tesa® 7476 at 70 ° C (rubber base) and under the brand BPS® 8170 (acrylic adhesive in solution).

- Control of instant adhesion performance without PSA "tack" pressure after contact with the silicone coating according to standard No. 9 of Finat edition No. 5 of 1999.

IV. Results:

Table 5 below summarizes the performances obtained.

TABLE 5

It is noted that this mixture of resin A1 = MM ^V 'Q; Bl = MD'Q provides a stronger modulating effect, especially at low modulator rates.

There is no impact on the "tack" of PSA having been in contact with the silicone coating. These mixtures of resins are clearly more effective than a resin A = MM ^V 'Q alone.

Claims

claims

1. Base adhesion modulator system:

• (A) at least one polyorganosiloxane resin in solid form in the dry state, and consisting of at least two different types of siloxy units 3SiOι / 2 (unit M) and S1O2 (unit Q) and / or SÎO3 2 (unit T), and optionally R2SiO units (unit D), the radicals R being identical or different and representing organic radicals, with a ratio number of units (M) / number of units (Q) and / or ( T) 0.6-1, the number of possible units (D) being 0.5-10 per 100 moles of resin;

• (B) at least one polyorganosiloxane resin in solid form in the dry state, and consisting of at least two different types of siloxy units R'3SiOι 2 (unit M) and S1O2 (unit Q) and / or R'Sι '03 ^/ 2 (T motif), and possibly R'2SiO motifs (motif

D), the radicals R ′ being similar or different and representing organic radicals, with a ratio of number of units (M) / number of units (Q) and / or (T) of 0.6-1, the number of units (D) optional being 0.5-10 per 100 moles of resin; • (C) and at least one solvent or at least one diluent of the mixture of resins (A) and (B); characterized in that:

• the resin (A) is reactive and represents an amount in parts by weight, from 99 to 75, preferably from 97 to 80, and more preferably still from 96 to 85;

• the resin (B) is non-reactive and represents an amount in parts by weight, from 1 to 25, preferably from 3 to 20, and more preferably still from 4 to 15 parts by weight.

2. Adhesion modulator system according to claim 1 characterized in that:

• in the resin (A), the radicals R independently and at least partially represent:

Φ alkyl groups - preferably C -C \ Q-, or (cyclo) alkyl - preferably C3- 18-,

Φ (cyclo) alkyl groups - preferably at C3- 18-, Φ alkenyl groups at C2-C Q, preferably at C2- 2, Φ C3-C20 (cyclo) αlkenyl groups. preferably in

C4-C12, Φ or αlcényl (C3-C9) oxyαlkylène (C2-C4) groups, preferably at least 80 mol% of the radicals R representing a methyl group,

> ^• at least 0.1 mol%, preferably 0.5 to 5 mol% of the radicals R representing an alkenyl or alkenyloxyalkylene group bonded to silicon ("Si-alkenyl"), the vinyl radical (Vi) being particularly preferred titer of R = alkenyl; • in the resin (B), the radicals R 'independently and at least partially represent: Φ hydrogen,

Φ alkyl groups - preferably C \ -C \% -, or (cyclo) alkyl - preferably 3-C18-, Φ or (cyclo) alkyl groups - preferably C3-C18-, preferably minus 80 mol% of the radicals R ′ representing a methyl group; • the resin (A) containing less than 2.5% (preferably less than 0.5%) molar of silanol functions; • the resin (B) containing less than 10% (preferably less than 2.5%) molar, of silanol functions.

3. Adhesion modulator system according to claim 1 or 2, characterized in that the reactive resin (A) is a resin which comprises Si-Vi units and which is chosen from the group comprising: - MD ^ 'Q where the vinyl groups are included in the patterns (D), ^ MD ^{7 *} 'TQ where the vinyl groups are included in the patterns (D), MM ^' Q where the vinyl groups are included in part of the patterns (M),> - MMV'TQ WHERE vinyl groups are included in part of the patterns

(M); > - MD ^ 'T where the vinyl groups are included in the units (D), ^ MM ^ ^exen y'Q (optionally comprising T units carrying or not an alkenyl group) where the hexenyl groups are included in a part units (M), MM ^A "y ' ^where yP ^ro Py'Q (optionally comprising units T carrying or not an alkenyl group) where the allyloxypropyl groups are included in a part of the units (M), > - all of the associations of each of the above resins with units M ^0H and / or D ^0H and / or T ^0H ,> - and their mixtures.

4. Adhesion modulator system according to any one of claims 1 to 3, characterized in that the non-reactive resin (B) is chosen from the group comprising:

> - MD'Q where the hydrogen atoms bonded to silicon are included in the units (D), MD'TQ where the ydrogen atoms bonded to the silicon are included in the units (D), MDD'Q where the atoms of hydrogen linked to silicon are included in the units (D),

> - MDD'TQ where the hydrogen atoms bonded to silicon are included in the units (D), - MDT 'where the hydrogen atoms bonded to the silicon are included in the units (T), - MDD'T' where the hydrogen atoms bonded to silicon are included in the units (T) and (D), ^ MDD'TT 'where the hydrogen atoms bonded to the silicon are included in the units (T) and (D), ^ MQ , ^ MDQ, MDTQ, - all the associations of each of the above-mentioned resins with units M ^0H and / or D ^0H and / or T ^0H , ^ and their mixtures.

5. Adhesion modulator system according to any one of claims 1 to 4, characterized in that the solvent or diluent (C) is chosen from '•

> (i) conventional hydrocarbon solvents of silicone resins, of aromatic type, saturated aliphatic, chlorinated solvents, used in an amount corresponding to 50-70 parts by weight per 30-50 parts by weight of solid resins (A) + (B);

> (2) so-called "reactive" solvents such as: a (a) liquid polyorganosiloxane resins, the organic radicals of which are alkyl or cycloalkyl groups in C \ -C \, alkenyl in C2-C20, preferably in C2-12, having a ratio number of units (M) / number of units (Q) and / or (T) of the order of 1 to 4 and optionally from 1 to 5 units (D) per 100 moles of liquid resin, and 5 containing from 0.5 to 5 mol% of alkenyl functions linked to silicon ("Si alkenyl") or of hydrogen atoms linked to silicon ("SiH"), resins having a viscosity at 25 ° C of less than 100 mPas., Preferably of the order of 2 to 50 mPas;

10 a and / or (b) fluid polyorganosiloxane oils, the organic radicals of which are C 1 -C 6 alkyl or cycloalkyl groups, C 2 -C 20 alkenyl groups, (C 3 -C 9) alkenyl (C 2 -C 4) oxyalkylene oils containing 0 , 2 to 5 mol% of alkenyl or alkenyloxyalkylene functions linked to

Silicon, at the chain end (s) or in the chain, said oils having a viscosity of less than 200 mPa.s; Q and / or (b ') fluid polyorganosiloxane oils, bearing hydrogen substituents and whose organic radicals are C \ -C \ alkyl or cycloalkyl groups

20 C2-C20 alkenyl, (C3-C9) alkenyl (C2-C4) oxyalkylene, oils containing from 0.2 to 5 mol% of hydrogen substituents bonded to silicon, at the chain end (s) or in the chain, the said oils with a viscosity of less than 200 mPa.s;

A and / or (c) olefinically unsaturated hydrocarbons such as C14-C18 olefins, dibutylmaleate, decylvinylether, dodecylvinylether, camphene, meta-bis isopropenylbenzene; said so-called "reactive" solvents being used according to a

30 amount corresponding to 20-50 parts by weight per 80-50 parts by weight of solid resins (A) + (B). > (S) aqueous emulsions of nonionic surfactants containing about 1-3% by weight of surfactant, used in an amount of 40-70 parts by

35 weights for 60-30 parts by weight of solid resins (A) + (B).

5. Curable non-stick compositions containing:

- at least one linear polydiorganosiloxane (D) blocked by triorganosiloxane end groups, said organic radicals being C 1 -C 4 alkyl or cycloalkyl groups, C2-C2O alkenyl preferably C2-C12 alkenyl, C3-alkenyl

C9) oxyalkylene (2-C4), at least 80 mol% of said radicals being a methyl group, at least 0.1 mol%, preferably from 0.5 to 5 mol% of said organic radicals being identical alkenyl or alkenyloxyalkylene groups or different directly linked to silicon ("Si alkenyl");

- at least one modulator system based on constituents (A), (B) and (C) as defined above;

- at least one hydrosilylation inhibiting agent;

- at least one linear polyorganohydrogensiloxane crosslinking agent (E) containing 1.6 to 0.5 mol% of hydrogen atoms directly attached to silicon ("SiH") at the chain end (s) and / or in the chain, the same or different organic radicals being C 1 -C 4 alkyl groups, at least 80 mol% of said organic radicals being methyl groups, the amount of crosslinking agent being such that the number of moles of " SiH "from non-reactive resin (B)," reactive "solvent (C) and crosslinking agent (E) / number of moles of" Si alkenyl "from reactive resin (A), solvent "reactive" (C) and blocked linear polydiorganosiloxane (D), ie greater than 1, preferably of the order of 1.1 to 2.5;

- an effective amount of a hydrosilylation catalyst.

6. Compositions according to claim 5, characterized in that the concentration of [POS (B)], in% by dry weight relative to the total mass, is defined as follows:

* [POS (B) j <20

*> preferably [POS (B)] <15

<* and more preferably still [POS (B)] <10.

7. Compositions according to claim 5 or 6, characterized in that the linear polydiorganosiloxane blocked with "Si-alkenyl" functions (D) has a viscosity of the order of 100 to 1000 mPas.

8. Compositions according to any one of claims 5 to 7, characterized in that the crosslinking agent with "Si-H" functions (E) has a viscosity of the order of 5 to 150 mPas.