KR101310554B1 - Pressure-sensitive adhesive silicone composition - Google Patents

Abstract

The present invention relates to a silicone composition comprising:
Hydroxylated silicone resin A of the MQ (OH) type;
Hydroxylated silicone rubber B; And
A third component comprising a vinylated silicone resin E of MQ or MQ (OH) type having a D ^Vi and / or M ^Vi pattern.
The invention also relates to a process for preparing the composition, to a composite comprising a substrate at least partially covered with such crosslinked silicone composition, and to the use of the silicone composition for full or partial coating of the substrate surface to impart adhesive properties thereto. will be.

Description

Pressure Sensitive Adhesive Silicone Composition {PRESSURE-SENSITIVE ADHESIVE SILICONE COMPOSITION}

The present invention relates to silicone based pressure sensitive adhesive compositions, methods for their preparation and their application.

In general, pressure sensitive adhesive compositions are denoted by the acronym PSA for "pressure sensitive adhesive". For the present invention it is therefore a "silicone PSA" composition.

Pressure-sensitive adhesives are adhesives that can simply contact or adhere to a surface under some pressure effect. There are several classes of pressure sensitive adhesives, including certain silicone compositions. Silicone PSAs have certain advantages over other classes of PSAs. Silicone PSAs are compositions that can be used over a wide temperature range and are resistant to harsh physical or chemical conditions (resistance to moisture, solvents, acids, UV radiation). They withstand microbiological attacks. Silicone PSAs have good insulation. In addition, these are generally hard to adhere to the surface containing polyester or polyimide, a printed circuit, etc., for example.

400 의 향상된 실리콘 PSA 조성물을 판매한다. 본 문맥에서 용어 "향상된" 은 일반적으로 가열에 의해 수득되는 SiOH 기의 부분 축합을 의미하는 것으로 재지칭된다.Bluestar Silicones is a trade name Rhodorsil which includes α, ω-hydroxyl linear silicone rubber and hydroxyl-functional silicone resins of the MQ (OH) type in solution in toluene.

Sells 400 enhanced silicone PSA compositions. The term "enhanced" in this context is generally reassigned to mean partial condensation of the SiOH groups obtained by heating.

US Pat. No. 5,602,214 describes silicone pressure sensitive adhesive compositions comprising silicone oil in addition to hydroxyl-functional silicone resins of the MQ (OH) type and α, ω-hydroxyl linear silicone rubber.

Patent application FR 2 705 355 describes a composition that can be used as a composition for pressure sensitive adhesives obtained by mixing the following:

Hydroxyl-functional MQ siloxane resins, which may or may not be alkenyl-functional;

Hydroxyl-functional silicone rubber;

And hydroxyl-functional silicone fluids of type MDT (OH) or DT (OH).

The composition is not satisfactory in view of the shear strength of the composite obtained by crosslinking of such composition.

Moreover, the difficulty of treating silicone resins presents obstacles to the use of silicone PSA compositions. Indeed, certain steps in the preparation of such silicone PSA compositions are carried out over hours at high temperatures, which represents a large energy cost.

It is therefore desirable to have a silicone pressure sensitive adhesive composition whose performance as an adhesive is comparable to the performance of known silicone PSA compositions, or in particular even with respect to tack. The production cost of such adhesive compositions should advantageously be reduced and the mechanical properties of the crosslinked compounds obtained should be improved.

Incidentally, after a long study Applicants developed a satisfactory silicone adhesive composition.

Accordingly, the subject of the present application is a silicone composition comprising:

- MQ (OH) type (wherein M: R1R2R3SiO _1/2 and Q (OH): (OH) a SiO _3/2, R1, R2 and R3 groups are selected independently of each other in the following:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

Hydroxyl-functional silicone resins A) or aryl or alkylaryl groups having 6 to 14 carbon atoms (including the border);

Hydroxyl-functional silicone rubber B; And

- D ^Vi and / or MQ type or MQ (OH) type containing M ^Vi units (wherein ^{_{M: R1R2R3SiO 1/2, M Vi:}} R1R2R4SiO 1/2, D Vi: R1R4SiO 2/2, Q: SiO 4 _{/ 2} and Q (OH): (OH) SiO 3/2 , and, R1, R2 and R3 groups are independently selected from each other, R4 is vinyl giim:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

A third component which is a vinyl-functional silicone resin E of aryl or alkylaryl groups having 6 to 14 carbon atoms (including boundaries).

Advantageously, these silicone compositions are also MDT (OH), or DT (OH) type (wherein M: a _{(OH) R1SiO 2/2,} : R1R2R3SiO 1/2, D: R1R2SiO 2/2 and T (OH) R1, R2 and R3 groups are independently selected from:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

Hydroxyl-functional silicone resins C) having 6 to 14 carbon atoms (including boundaries) aryl or alkylaryl groups).

Such silicone compositions optionally comprise one or more organic solvent (s) S.

Preferred silicone compositions are also as follows:

Condensation catalyst F; And

-Neutralizer G,

And advantageously both.

In the description and claims, the singular definite article or the indefinite article (eg, the expression "a" in the expression "a condensation catalyst") also refers to the plural definite article unless the context clearly dictates the opposite interpretation (numeric "one"). It should be noted that it should be understood as ("some" or "one or more"). Unless otherwise indicated, it is preferable to regard the technical and scientific terms used in their meanings as commonly understood by one of ordinary skill in the art.

In the remainder of this application, polyorganosiloxane (POS) oils, rubbers, and resins will be commonly described using conventional notation in which the letters M, D, T, and Q are used to mean various siloxy units. In this notation, the silicon atoms of the siloxy units are included in one (M), two (D), three (T) or four (Q) covalent bonds with many oxygen atoms. If an oxygen atom is shared between two silicon atoms, it is calculated as ½ and will not be mentioned in the abbreviated formula. On the other hand, when the oxygen atom belongs to an alkoxy or hydroxyl group bonded to a silicon atom, such chemical functional group will be represented between parentheses in the abbreviated formula. Basically, the remaining bonds of silicon atoms are considered to involve carbon atoms. In general, hydrocarbon-based groups linked to silicon by C-Si bonds are not mentioned and typically correspond to alkyl groups, for example methyl groups. For example, the abbreviated formula T (OR) ₂ is in a unit, that is, alkyl dialkoxy siloxy units _{RSi (OR) 2 O 1/} 2 ( equation binding to three oxygen atoms comprising a silicon atom 2 alkoxy, R is an alkyl group. If the hydrocarbon-based group has a particular functionality, it is indicated by superscript. For example, the abbreviated formula M ^Vi is a unit in which one of the hydrocarbon groups in which the silicon atom is bonded to the oxygen atom and forms a C-Si bond is a vinyl group, ie a dialkylvinylsiloxy unit R ₂ Si (Vi) O _{1 / 2} (wherein R is an alkyl group).

In this formula, R can represent a variety of saturated or unsaturated, especially aromatic, hydrocarbon-based groups, optionally substituted by heteroatoms. The meaning of R will be embodied in the detailed description.

The expression “substantially linear” should be understood to mean a polyorganosiloxane oil consisting of D siloxy units, which also includes T siloxy units and / or Q siloxy units, and of the T and Q siloxy units The number is 1 or less per 100 silicon atoms.

The expression "silicone resin" means a polysiloxane comprising T and / or Q siloxy units, and optionally a significant fraction of D and / or M siloxy units. The expression "significant fraction" is understood to mean at least 5%, preferably 25% and especially more than 30% units (mol%).

The expression "silicone rubber" has a high molecular weight whose terminal can be functionalized into the reactor, for example more than 100,000 μg / mol, preferably more than 125,000 g / mol, especially more than 200,000 g / mol, very particularly 250,000 μg / mol By more polydialkylsiloxanes are meant.

In the present application, and to, MQ (OH) type of hydroxyl-functional silicone resin A is a ^{M: R 1 R 2 R 3} SiO 1/2, Q: SiO 4/2 and Q (OH): (OH) means a copolymer consisting of SiO _3/2 siloxy units. R ¹ , R ² And R ³ groups are independently selected from:

Linear or branched alkyl groups of 1 to 8 carbon atoms inclusive, in particular 1 to 6 carbon atoms inclusive such as methyl, ethyl, isopropyl, tert -butyl and n-hexyl groups;

It is optionally substituted by one or more halogen atoms, in particular 2 or 3 halogen atoms (3,3,3-trifluoropropyl groups may be mentioned in particular); And

Aryl or alkylaryl groups having 6 to 14 carbon atoms inclusive, in particular phenyl, xylyl and tolyl groups.

The "alkyl" group for the hydroxy-functional silicone resin A is preferably a lower alkyl group having 1 to 6, preferably 1 to 3 or 4 carbon atoms in the main chain. The variant may be linear or branched and methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert -butyl, pentyl, hexyl and the like can be mentioned. Such compounds may be substituted by aliphatic or cyclic hydrocarbon-based radicals or halogens.

The hydroxyl-functional silicone resin A is for example 40 to 80 mol% M units, 30 to 55 mol% Q units, 5 to 15 mol% Q (OH) units and 0.5 to 4 to dry weight of the resin Wt% -OH hydroxyl units.

Its Brookfield viscosity is in particular between 10 and 40 mm 2 / s.

Under the preferred conditions for carrying out the invention, the hydroxyl-functional silicone resin A has 45-55 mol% M units, 38-45 mol% Q units, 7-10 mol% Q (OH) based on the dry weight of the resin. ) Units and 2.3 to 3 kPa% -OH hydroxyl units with a Brookfield viscosity of 12 to 18 kPamm 2 / s.

The hydroxyl-functional silicone rubber B is for example a high molar mass of α, ω-dihydroxyl polydialkylsiloxane, preferably α with an average molecular weight Mn> 100,000 g / mol, more particularly Mn> 150,000 g / mol , ω-dihydroxyl polydimethylsiloxane.

In polydialkylsiloxanes, "alkyl" groups are preferably lower alkyl groups having 1 to 10, preferably 1 to 3, carbon atoms in the main chain. The chain can be linear or branched and methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert -butyl, pentyl, hexyl and the like can be mentioned. Such compounds may be substituted by aliphatic or cyclic hydrocarbon-based radicals or halogens.

The hydroxyl-functional silicone rubber B may also be a statistical copolymer of polydimethylsiloxane and polymethylphenylsiloxane having silanol groups located mainly at the chain ends.

The vinyl-functional silicone resin E of the MQ or MQ (OH) type comprising D ^Vi and / or M ^Vi units preferably comprises less than 5% by weight of Vi groups, for example with respect to the dry matter of the resin MD ^Vi Q (OH), MM ^Vi Q (OH) resin with less than 0.4 wt% OH. Such resins can often be predispersed in aromatic or aliphatic solvents with 40-65% of the dry matter. The molar mass of such resins may range from 2000 to 4000 g / mol, for example.

It may represent 1 to 20% by weight, advantageously 2 to 15% by weight, preferably 2.5 to 10% by weight of the total dry weight of the crosslinkable silicone composition of the present invention.

If the silicone composition of the invention comprises a hydroxyl-functional silicone resin C, it is of the MDT (OH) or DT (OH) type, and the M, D and T units are preferably methyl- or phenyl-functional, More particularly methyl-functional units.

The hydroxyl-functional silicone resin C is, for example, 15 to 30 mol mol D units, 50 to 75 mol mol T units, 0 to 20 mol mol M units and 0.1 to 3 wt% with respect to the dry weight of the resin. Of -OH hydroxyl units.

Its Brookfield viscosity is in particular 500 to 8000 mm 2 / s, preferably 800 to 1200 mm 2 / s.

The silicone composition of the present invention may comprise, for example, 100% of the silicone active material, and on a dry / dry basis, for example:

20 to 80% by weight, preferably 35 to 60% by weight, very particularly 45 to 50% by weight of hydroxyl-functional silicone resin A;

20 to 80% by weight, preferably 30 to 55% by weight, very particularly 35 to 45% by weight of hydroxyl-functional silicone rubber B;

1 to 20% by weight, advantageously 2 to 15% by weight, preferably 2.5 to 10% by weight of vinyl-functional silicone resin E; And

1 to 35% by weight, preferably 2 to 30% by weight, in particular 5 to 20% by weight, very particularly 5 to 16% by weight of hydroxyl-functional silicone resin C.

D40 또는 D60 으로 Exxon 에서 시판되는 탈방향화 지방족 탄화수소일 수 있다. 이러한 용매는 일반적으로 60 내지 200℃ 의 비등점을 갖는다.If the silicone composition of the invention comprises one or more organic solvent (s) S, it is for example an aromatic or aliphatic solvent (hexane, heptane, etc.), preferably toluene, xylene or optionally alkylbenzenes, or oil fractions Example trade name Exxsol

It may be a dearomatized aliphatic hydrocarbon commercially available from Exxon as D40 or D60. Such solvents generally have a boiling point of 60 to 200 ° C.

It may represent 20 to 80% by weight, advantageously 30 to 60% by weight, preferably 35 to 50% by weight and very particularly 40 to 60% by weight of the total weight of the crosslinkable silicone composition of the present invention.

Condensation catalysts F which can be used are for example alkali metal, amine or organometallic salts, preferably alkali bases such as KOH and NaOH, optionally aqueous solutions, more particularly one (or one) with one of these bases (eg KOH) Silanolate due to the reaction between the silicone oligomer (s).

The catalyst dosage is determined by its effectiveness in silanol condensation, the temperature of the conversion reaction, and whether techniques are used that can facilitate the removal of water formed by condensation of such silanol (cohobator, Dean-Stark ( Dean-Starck, etc.). It may represent 10 to 2000 ppm by weight, preferably 20 to 1500 ppm by weight, very particularly 35 to 1500 ppm by weight, of the total weight of the dry silicone composition of the present invention relative to the dry silicone mixture.

Neutralizing agents G which can be used are, for example, reaction products of organic or inorganic acids, preferably phosphoric acid or acetic acid or carboxylic acid, more particularly phosphoric acid with one (or more than one) silicone oligomer (s).

The dose of neutralizing agent is of course dependent on the amount of condensation catalyst used in the conversion reaction. It is necessary to adjust this dosage for the purpose of obtaining a slight excess molar acid relative to the base amount introduced for good neutralization, or optionally conversion, of the silicone PSA. The quality of the conversion of the silicone PSA can be monitored by assaying residual silanol.

Typically, PSAs are commercially available in a relatively concentrated form (typically containing less than 50% by weight of solvent), wherein the coating client is generally coated as a function of the client's coating machine to adjust the thickness of the silicon deposition on the support. Before running the process, slightly dilute the PSA with a solvent such as toluene.

The present application therefore also provides for example a diluted solution by adding a volume of solvent such that the diluted composition comprises 20 to 60% by weight, preferably 25 to 55% by weight, very particularly 30 to 50% by weight, as the silicone solids content. It aims at the said composition.

During the formation of a bath thereof, the coater also often adds crosslinking agents, in particular agents which crosslink via the radical pathway, such as peroxides, which enable to initiate complementary crosslinking of the silicone on its support at the moment it passes through the oven. . The preferred silicone compositions of the invention therefore also comprise at least one crosslinking agent, in particular 2,4-dichlorobenzoyl (DCB) peroxide, such as peroxide, which is crosslinked via the radical pathway.

The silicone composition can generally be prepared by mixing the following with an organic solvent S:

- MQ (OH) type (wherein M: R1R2R3SiO _1/2 and Q (OH): (OH) a SiO _3/2, R1, R2 and R3 groups are selected independently of each other in the following:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

Hydroxyl-functional silicone resins A) or aryl or alkylaryl groups having 6 to 14 carbon atoms (including the border);

Hydroxyl-functional silicone rubber B; And

- D ^Vi and / or MQ type or MQ (OH) type containing M ^Vi units (wherein ^{_{M: R1R2R3SiO 1/2, M Vi:}} R1R2R4SiO 1/2, D Vi: R1R4SiO 2/2, Q: SiO 4 _{/ 2} and Q (OH): (OH) SiO 3/2 , and, R1, R2 and R3 groups are independently selected from each other, R4 is vinyl giim:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

Vinyl-functional silicone resins of aryl or alkylaryl groups having from 6 to 14 carbon atoms inclusive;

Further, the mixture of the MDT (OH), or DT (OH) type (wherein _{M: R1R2R3SiO 1/2, D} : R1R2SiO 2/2 and T (OH): (OH) ₂ and R1SiO _{/ 2,} R1, R2 and R3 The groups are independently selected from:

Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And

Hydroxyl-functional silicone resins C) having 6 to 14 carbon atoms (including boundary values) or aryl or alkylaryl groups).

Any component, ie the neutralizing agent G after the condensation catalyst F, may also be incorporated.

Any condensing agent can also be incorporated into the mixture.

Finally, the solvent can be incorporated into the mixture.

The silicone composition can in particular be prepared as follows:

a) hydroxyl-functional silicone resin A of type MQ (OH), hydroxyl-functional silicone rubber B and vinyl-functional silicone resin E of type MQ or MQ (OH) E (including D ^Vi and / or M ^Vi units) ) Is mixed with an organic solvent S, and optionally a hydroxyl-functional silicone resin C of type MDT (OH) or DT (OH) is added, and then the whole mixture is mixed at high temperature; Next, if necessary, the condensation catalyst F is still added at a high temperature, and after allowing the condensation reaction to occur, the neutralizing agent G is added to the mixture to obtain the expected composition.

b) hydroxyl-functional silicone resin A of type MQ (OH), hydroxyl-functional silicone rubber B and vinyl-functional silicone resin E of type MQ or MQ (OH) E (including D ^Vi and / or M ^Vi units) ) Is mixed with the organic solvent S, the whole mixture is mixed at high temperature, and then the condensation catalyst F is still added at a high temperature, the condensation reaction is allowed to occur, and the neutralizing agent G is added to the mixture, followed by MDT (OH) or DT ( Hydroxyl-functional silicone resin C of type OH) is optionally added to obtain the predicted composition, if necessary followed by evaporation of the solvent by addition of a crosslinking agent, in particular an agent which crosslinks via the radical pathway, or an organic solvent, or both A coating bath is obtained that allows a silicon deposition of the desired thickness to be produced. The solids content of the bath is generally about 25 to 50% of silicone, such that a final (dry) silicon deposit of tens of micrometers (eg 30 to 60 micrometers) is obtained. These values are, of course, indicative and depend on the target application characteristics.

c) hydroxyl-functional silicone resin A and hydroxyl-functional silicone rubber B of type MQ (OH) are mixed in organic solvent S, hydroxyl-functional silicone resin C of type MDT (OH) or DT (OH) and Addition of vinyl-functional silicone resins E (including D ^Vi and / or M ^Vi units) of the MQ or MQ (OH) type, allowing the condensation reaction to occur, and if necessary crosslinking agents, in particular agents which crosslink via the radical pathway , Or an organic solvent, or both, are added to obtain a coating bath as in b).

Hydroxyl-functional silicone resin A of MQ (OH) type, hydroxyl-functional silicone rubber B and vinyl-functional silicone resin E of MQ or MQ (OH) type (including D ^Vi and / or M ^Vi units) When is mixed with the organic solvent S at a high temperature, this mixing can be carried out at a temperature close to the boiling point of the organic solvent, that is, at a temperature of boiling point ± 5 ℃ of the solvent.

In order to facilitate the condensation of silanol, a "din-stark" or "redistillation, which enables the recovery and separation of the aqueous phase from a solvent medium which is capable of promoting the removal of water formed, for example recycled into the reactor. A device referred to as a "cohobation" device can be used.

Silicone compositions, which are the subject of the present invention, have very advantageous properties and qualities. It may be crosslinked to a pressure sensitive adhesive that justifies its use for the preparation of a silicone pressure sensitive adhesive composition.

For some of these, the silicone pressure sensitive adhesive compositions of the present invention are particularly endowed with significant tack, peel strength and shear strength properties simultaneously.

The main properties of the PSA composition are actually tack, peel strength and shear strength. Tackiness is characterized by the adhesion of the pressure-sensitive adhesive and includes two factors: the viscoelasticity of the adhesive and the nature of the bond instantaneously produced with the support. Peel strength allows to evaluate the force required to separate the adhesive tape from the support. Shear strength makes it possible to measure the resistance at ambient temperature of an applied sheared force forced by suspension weight. A variety of standardized measurements exist and are well known to those skilled in the art.

These characteristics are explained in the experimental section below. This is the peroxide used in the whole or partial coating of the support surface for imparting adhesive properties, and also after the surface of the support is coated, in whole or in part, with the crosslinkable silicone composition described above previously containing peroxide. It justifies the use of the crosslinkable silicone composition described above in a method for imparting adhesive properties to a support, wherein the crosslinking is carried out by heating the silicon-treated support at a temperature at which the activity of the solvent and the solvent can be removed.

This is why another subject of the present invention is a composite comprising a support at least partially coated with the crosslinked silicone composition.

The support may be of a wide variety of properties depending on the application. For example, a support having a high surface energy such as metal, aluminum or glass may be mentioned. For example, plastics such as polyester, polyimide, polyethylene terephthalate, or films made of certain polydimethylsiloxanes may also be mentioned.

Depending on the type of support, various techniques may be implemented.

In particular, for flat supports such as sheets, films, strips and the like, it will be possible to use coating machines, in particular coating machines with rollers.

Preferred treatment conditions of the crosslinkable silicone composition described above also apply to other subjects of the invention aimed at the above, in particular to composites comprising a support at least partially coated with the crosslinked silicone composition.

The present application is described in the following examples.

Material and product:

The following materials and products were used:

1 L glass reactor with Dean-Stark device and condenser;

Stainless steel scraping anchor type stirrer;

A heating bath consisting of a stainless steel beaker containing a thermal fluid (silicone oil) and placed in a magnetic stirrer hotplate;

Toluene, and of containing the active substance 60%, Mn = 2800 g / mol , and 2.5 weight% OH include (with respect to dry resin), and having a viscosity of _{15 ㎟ / s Me 3 SiO 1} /2 units (approx. 50 mol%), an MQ (OH) silicone resin consisting of SiO ₂ units (about 40%) and Q (OH) units (about 10%), (A);

[Alpha], [omega] -dihydroxyl polydimethylsiloxane rubber, having a hardness of 800 [mu] mm / 10 and Mn [deg.] = 3333 [mu] g / mol;

-Silicone resin (E) consisting of MD ^Vi Q (OH) units, containing 2.5% by weight Vi and 0.3% by weight OH in a solution of 60% by weight of xylene, with a molar mass Mn = 3270 g / mol, relative to the dry resin );

About 64 mol% of MeSiO _3/2 units, 23 mol% of Me ₂ SiO units and 13 mol% of Me ₃ SiO _1/2 contains the units and Mn = 1680 g / mol and, R / Si ratio = 1.4 A silicone resin comprising MDT (OH) units, comprising 0.5 wt% OH and having a viscosity of 1000 mm 2 / s, (C);

Solution (F) of the condensation catalyst in toluene (prepared immediately before the test): dilution of 2.7 g of the reaction product of siloxane oligomers (D4, M2) with KOH to 40 g of toluene. Initial reaction product was titrated with 14.5% KOH and density = 1.023;

Diluted neutralizing solution (G) in toluene (previously prepared for testing): dilution of 6 g of the reaction product of siloxane oligomers (D4 and 47V3) with H ₃ PO ₄ to 61.9 g of toluene. Initial reaction product was titrated with 8.5% H ₃ PO ₄ and density = 1.580.

Control:

The viscosity of PSA was measured at a speed of 2.5 using a Brookfield DV-II + device with five needles.

After 1 hour at 150 ° C. in a ventilated oven, the solids content of the PSA was determined by measuring the weight loss from about 1 g of PSA.

Produce:

Example 1: pressure-sensitive adhesive according to the present invention ( PSA ) Preparation of the composition

After 500 g of MQ (OH) resin (A) and 255 g of toluene were introduced into the reactor, stirring was started at a speed of 110 rpm.

A small amount of silicone rubber (B) (255 μg) was added with stirring for 1 hour.

The heating bath was turned on and 6.78 g of a dilute solution of the condensation catalyst was introduced when the temperature of the reaction mixture reached 113 ° C. After stirring for 4 hours under toluene reflux, 9.05 lg of a dilute neutralization solution was introduced to neutralize the catalyst. After 20 minutes, the heating bath was removed and the mixture was cooled. A crosslinkable base composition referred to as CBR1 was obtained.

1.00 g of MD ^Vi Q (OH) resin (E), 0.63 g of 2,4-dichlorobenzoyl (DCB) peroxide, were recovered at a low temperature with still stirring after recovering 40.00 g of an aliquot of the obtained base composition CBR1. And 20.54 g of toluene were added.

The pressure sensitive adhesive composition obtained was packaged in glass vials.

Example 2 to 6: pressure-sensitive adhesive according to the invention ( PSA ) Preparation of the composition

The procedure in Example 1 was followed using the amounts of base composition CBR1, toluene, DCB peroxide and MD ^Vi Q (OH) resin (E), indicated in g in Table 1 below.

Example Base Composition CBR1
(66% A + 34% B) Resin (E)
MD ^Vi Q (OH) DCB peroxide toluene 2 40.00 2.00 0.63 20.54 3 40.00 3.00 0.63 20.54 4 40.00 4.00 0.63 20.54 5 40.00 6.00 0.63 20.54 6 40.00 8.00 0.63 20.54

Comparative example One: MD ^Vi Q ( OH Pressure sensitive adhesive without resin (E) PSA ) Preparation of the composition

A 40.00 μg aliquot of the base composition CBR1 obtained in Example 1 was recovered and 0.63 μg of DCB peroxide and 20.54 μg of toluene were added at low temperature while stirring.

The resulting control pressure sensitive adhesive composition was packaged in glass vials.

Example 7: pressure-sensitive adhesive according to the invention ( PSA ) Preparation of the composition

709.85 g of MQ (OH) resin (A) and 403.75 g of toluene were introduced into the reactor, and then stirring was started at a speed of 110 rpm.

A small amount of silicone rubber (B) (386.40 g) was added with stirring over 1 hour. The temperature reached by self-heating was about 40-45 ° C. After complete dissolution of the rubber, the base composition in the form of a homogeneous mixture was stored at ambient temperature. A crosslinkable base composition referred to as CBR2 was obtained.

Next, to the 40.39 g aliquot of the base composition CBR2 was added 3.08 g of MD ^Vi Q (OH) resin (E), 20.57 g of DCB peroxide and 20.57 g of toluene at low temperature with stirring.

The pressure sensitive adhesive composition obtained was packaged in glass vials.

Example 8: pressure-sensitive adhesive according to the invention ( PSA ) Preparation of the composition

To 40.62 g aliquots of base composition CBR2, 3.03 g MD ^Vi Q (OH) resin (E), 1.05 g MDT (OH) resin (C), 0.63 g DCB peroxide and 20.60 g at low temperature with stirring Toluene was added.

The pressure sensitive adhesive composition obtained was packaged in glass vials.

Example 9 and 10: pressure-sensitive adhesive according to the invention ( PSA ) Preparation of the composition

The procedure in Example 8 was followed using the amounts of base composition CBR2, toluene, DCB peroxide, MDT (OH) resin (C) and MD ^Vi Q (OH) resin (E), indicated in g in Table 2 below. Followed.

Example Base Composition CBR2
(65% A + 35% B) MD ^Vi Q (OH) Resin (E) MDT (OH) Resin (C) DCB peroxide toluene 9 40.09 3.10 2.04 0.64 20.68 10 40.12 3.13 3.10 0.64 20.57

Comparative example 2: MD ^Vi Q ( OH Pressure sensitive adhesive without resin (E) PSA ) Preparation of the composition

To a 39.93 μg aliquot of the base composition CBR2 obtained in Example 7, 0.63 μg of DCB peroxide and 20.55 μg of toluene were added at low temperature while stirring.

The resulting control pressure sensitive adhesive composition was packaged in glass vials.

Preparation of the composite:

For Examples # 1 to 10 and Comparative Examples # 1 and 2, the mixtures described were already of the required solids content and already included peroxide catalysts. This has therefore been applied as for polyethylene terephthalate (PET) films of 36 μm thickness. The coating was carried out on a coating bench which allowed to adjust the distance between the support (PET film) and the doctor blade to obtain the desired coating thickness. Therefore, a coating of 50 μm thick was carried out. The solvent was then evaporated under a fume hood for 15 minutes and radical crosslinking was initiated in the oven at 170 ° C. over 2 minutes.

Thus, a PET film coated with the adhesive was obtained.

The adhesive was then protected with a polyethylene terephthalate film coated with 1 μm of fluorosilicone and passed through the press at a rate of 25 kg / cm, then 45 kg / cm at a rate of 3 m / min to remove any bubbles. Removed. Such mixtures are referred to as "composites".

Properties of Compositions and Films:

The properties of the polyethylene terephthalate film coated with the adhesive were demonstrated using the following test:

Test protocol

1. Tackiness:

ASTM D 2979 "Probe Tack" standard. The metal rod connected to the force sensor was contacted with the sample at a rate of 1 cm / second. The contact time was 1 second. The force required to separate the rod from the adhesive-coated film was measured and expressed in g / cm 2.

2. Peel strength:

ASTM D 330 A standard. Adhesive-coated film was applied to the metal plate. After standing for 1 minute, the film was removed from the plate at a constant rate of 300 mm 3 / min at a 180 ° angle. Peel strength was measured by the sensor in g / cm.

3. Shear strength:

PSTC 107A and ASTM D 6463 A Modified "shear test" standard. The adhesive-coated film was bonded to a metal plate. A weight of 1 kg was added for the maximum time set to 7 days. The time before the bonding force breakage of the adhesive was measured and expressed in time.

result

The results showed that adding MD ^Vi Q resin at low temperature produced the following for the properties of PSA:

Very large increase in peel strength (57%); And

Significant increase in shear strength.

By post-addition at low temperature, the addition of MDT (OH) resin (C) could significantly increase the tackiness of PSA without lowering the peel strength.

conclusion

The results show the following:

MD ^Vi Q resin can increase peel strength and shear strength;

Supplemental addition of MDT (OH) resin increases tack without degrading mechanical properties (peel strength).

The results indicate that it is possible to produce PSAs that do not improve and have completely acceptable adhesive properties.

Claims (15)

Silicone compositions comprising:
- MQ (OH) type (wherein M: R1R2R3SiO _1/2 and Q (OH): (OH) a SiO _3/2, R1, R2 and R3 groups are selected independently of each other in the following:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
Hydroxyl-functional silicone resins A) or aryl or alkylaryl groups having 6 to 14 carbon atoms (including the border);
Hydroxyl-functional silicone rubber B; And
- D ^Vi and / or MQ type or MQ (OH) type containing M ^Vi units (wherein ^{_{M: R1R2R3SiO 1/2, M Vi:}} R1R2R4SiO 1/2, D Vi: R1R4SiO 2/2, Q: SiO 4 _{/ 2} and Q (OH): (OH) SiO 3/2 , and, R1, R2 and R3 groups are independently selected from each other, R4 is vinyl giim:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
A third component which is a vinyl-functional silicone resin E of aryl or alkylaryl groups having 6 to 14 carbon atoms (including boundaries). According to claim 1, MDT (OH), or DT (OH) type (wherein _{M: R1R2R3SiO 1/2, D} : R1R2SiO 2/2 and T (OH): (OH) a R1SiO _2/2, R1, R2 And R 3 groups are independently selected from:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
Hydroxy or functional silicone resins C having from 6 to 14 carbon atoms (including bounds). The composition of claim 1 or 2, further comprising:
Condensation catalyst F; And
-Neutralizer G. The hydroxyl-functional silicone resin A according to claim 1 or 2, wherein the hydroxyl-functional silicone resin A is 45 to 55 mol% M units, 38 to 45 mol% Q units, 7 to 10 mol% Q (OH) units, and the resin 0.5 to 4 weight percent of -OH hydroxyl units relative to the dry weight of the composition. 3. The composition according to claim 1, wherein the hydroxyl-functional silicone rubber B is α, ω-dihydroxy polydialkylsiloxane having a molar mass of at least 40,000 μg / mol. 3. The vinyl-functional silicone resin E of the MQ or MQ (OH) type comprising D ^Vi and / or M ^Vi units comprises at least 5% by weight of Vi groups relative to the dry matter of the resin and MD ^Vi Q (OH), MM ^Vi Q (OH) resin comprising less than 0.4% by weight of OH. The composition according to claim 2, wherein the M, D and T units in the hydroxyl-functional silicone resin C of the MDT (OH) or DT (OH) type are methyl- or phenyl-functional units. The hydroxyl-functional silicone resin C according to claim 2, wherein the hydroxyl-functional silicone resin C is 15 to 30 mol mol D units, 50 to 75 mol mol T units, 0 to 20 mol mol M units and 0.1 to 3 dry weight of the resin. A composition comprising by weight -OH hydroxyl units. delete The composition of claim 1 or 2, further comprising at least one crosslinking agent. A method for producing a silicone pressure sensitive adhesive composition, characterized by mixing the following into an organic solvent S:
- MQ (OH) type (wherein M: R1R2R3SiO _1/2 and Q (OH): (OH) a SiO _3/2, R1, R2 and R3 groups are selected independently of each other in the following:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
Hydroxyl-functional silicone resins A) or aryl or alkylaryl groups having 6 to 14 carbon atoms (including the border);
Hydroxyl-functional silicone rubber B; And
- D ^Vi and / or MQ type or MQ (OH) type containing M ^Vi units (wherein ^{_{M: R1R2R3SiO 1/2, M Vi:}} R1R2R4SiO 1/2, D Vi: R1R4SiO 2/2, Q: SiO 4 _{/ 2} and Q (OH): (OH) SiO 3/2 , and, R1, R2 and R3 groups are independently selected from each other, R4 is vinyl giim:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
Vinyl-functional silicone resins of aryl or alkylaryl groups having from 6 to 14 carbon atoms inclusive; 12. The method of claim 11, of the MDT (OH), or DT (OH) type (wherein _{M: R1R2R3SiO 1/2, D} : R1R2SiO 2/2 and T (OH): (OH) ₂ and R1SiO _{/ 2,} R1, R2 And R 3 groups are independently selected from:
Linear or branched alkyl groups of 1 to 8 carbon atoms (including boundaries), optionally substituted by one or more halogen atoms; And
Hydroxyl-functional silicone resins C having 6 to 14 carbon atoms (including boundaries), in addition to the mixture. 13. Process according to claim 11 or 12, wherein the condensation catalyst F and the neutralizing agent G are also incorporated into the mixture. A composite as defined in claim 1 or 2, comprising a support at least partially coated with a crosslinked silicone composition. The silicone composition according to claim 1 or 2, which is a composition for full or partial coating of the surface of the support for imparting adhesive properties.