Adhesive composition for bonding substrates having low surface energy

Abstract

The present invention relates to: - hot melt adhesive compositions containing a mixture of silylated polymers, tackifying resins and catalysts in specific contents, in particular containing catalysts that have self-adhesive properties after crosslinking with water; - a self-adhesive article comprising a support layer and at least one self-adhesive layer obtained after crosslinking with water in the adhesive composition according to the invention; and their use for bonding low energy substrates, in particular plastic substrates, especially thermoplastic substrates having a low surface energy. [Selection diagram] None

Description

[Technical Field]

[0001] The present invention relates to a hot melt adhesive composition that has self-adhesive properties after crosslinking with moisture, comprising a mixture of a silylated polymer, a tackifying resin, and a catalyst in specific proportions.

[0002] The present invention also relates to a self-adhesive article such as a self-adhesive multi-layer system comprising a support layer and at least one self-adhesive layer obtained after crosslinking of the adhesive composition according to the invention by moisture.

[0003] The present invention also relates to adhesive compositions according to the invention in the crosslinked state and self-adhesive articles according to the invention for bonding low surface energy substrates, in particular plastic, especially thermoplastic, substrates having low surface energy. [Background technology]

[0004] Hot melt (HM) adhesives are substances that are solid at room temperature and contain neither water nor solvents. They are applied in a molten state and solidify upon cooling, thereby forming a seal that ensures the bonding of assembled substrates. Some hot melts are formulated to impart relatively hard, tack-free properties to the substrate coated with the melt. Other hot melts impart relatively flexible characteristics and substantial tack to the substrate; these are PSAs that are widely used in the production of self-adhesive labels and are referred to as "hot melt pressure-sensitive adhesives" (or HMPSAs).

[0005] Pressure-sensitive adhesives (also known as self-adhesives or PSAs) provide instant tack at room temperature to adhesive-coated substrates, allowing for instant adhesion to substrates when slight, brief pressure is applied. PSAs are widely used to produce labels or self-adhesive films that are temporarily or permanently attached to articles for the purposes of presenting information (e.g., bar codes, names, prices) and / or for decorative purposes. PSAs are also used to ensure durable labeling of electrical, electronic, or mechanical components where information must remain attached for extended periods, even years, and / or under difficult use conditions, including exposure to solvents, chemicals, natural or artificial light, and radiation, along with normal or accidental movement and deformation by humans or machines. They are also used to manufacture self-adhesive tapes for a variety of applications. In addition to the transparent adhesive tapes that are widely used in everyday life, PSAs are used in various industrial applications, such as the forming and assembly of cardboard packaging; for protecting surfaces in painting operations in the construction sector; for supporting electrical cables in the transport industry; in double-sided adhesive tapes used to fasten carpets; for assembling parts or equipment in the automotive, construction, textile, wood and plastics industries; and in the construction of objects and buildings for assembling electrical or electronic equipment, tools and equipment used by professionals or the general public.

[0006] In the production of multi-layer systems, especially labels and / or self-adhesive tapes, the PSA is usually 2 It is often applied by a continuous coating method to the entire surface of a large support layer in an amount expressed in units of area (hereinafter referred to as "weight per unit area"). The support layer consists of one or more layers of paper or film made of polymeric material. The adhesive layer covering the support layer can itself be covered with a protective non-stick layer (often called a "release liner"), for example, composed of a silicone film. The resulting multi-layer system can generally be packaged for storage and transportation by winding it onto large reels up to 2 meters wide and 1 meter in diameter.

[0007] These multilayer systems can then be converted into self-adhesive labels for use by end users by a conversion process that involves printing desired information and / or decorative elements onto the printable side of the support layer and cutting to the desired shape and size. The protective release liner can be easily removed without modifying the adhesive layer, which remains fixed to the support layer. After separation from the protective release liner, the label is applied to the substrate surface to be applied, either manually or using a labeling machine on an automated packaging line.

[0008] These multi-layer systems can also be converted into self-adhesive tapes by cutting and packaging into rolls of predetermined width and length.

[0009] Due to their high tack at room temperature, PSAs generally allow for rapid bonding or adhesion of labels and / or self-adhesive tapes to the substrate to which they are applied, which is suitable for obtaining high industrial production rates.

[0010] The properties of a substrate surface can be characterized by its surface energy, which can be quantified in a manner well known to those skilled in the art from contact angle measurements and calculated according to the Owens & Wendt model.

[0011] For comparable surface areas, PSA compositions suitable for bonding to substrates with high surface energy (or surface tension), such as inorganic polar substrates like glass or metal, are not necessarily suitable for bonding to substrates with low surface energy, such as polar organic substrates, including polymeric materials based on ethylene-type or propylene-type monomers and comonomers, commonly known as polyethylene (PE) and polypropylene (PP) substrates, respectively. The category of low surface energy substrates also includes polymeric materials based on other olefin monomers and any coatings on films or objects that are generally difficult to bond with PSAs.

[0012] It is known that low surface energies, such as those referred to above, are difficult to bond to and often require specific treatment of said surfaces before laminating the self-adhesive parts of labels or adhesive tapes. These treatments are well known to those skilled in the art and consist of chemically and / or physically modifying the substrate surface to increase the surface energy and / or the roughness of said surface, thereby improving the adhesion of the adhesive to the substrate. For example, the substrate surface can be treated by plasma or corona processes, by abrasion, or by applying a chemical adhesive (also called primer) to the surface to be treated in order to advantageously modify the surface energy of the substrate.

[0013] Without such surface treatment, the adhesion of adhesives to this type of substrate is often insufficient to effectively bond a label or adhesive tape to the surface of the substrate. The effectiveness of such a bond should be considered depending on the type of intended use. Typically, it is desirable for the adhesive bond ensuring the attachment of two objects to have minimal resistance when subjected to the following stresses: peel, pull, or shear. It is also desirable for these properties to remain consistent over a wide range of temperatures, especially when the adhesive bond (and consequently the product bearing the label and / or adhesive tape) is subject to temperature changes, for example, during transportation, storage, and use. It is also desirable for these advantageous properties not to deteriorate over time, or at least to be maintained for a sufficiently long time, for example, with respect to the use or service life of the self-adhesive article or the product to which the self-adhesive article is attached. In some applications, a specific failure profile of the adhesive bond with respect to the substrate surface is required. Preferentially, uniform failure of the adhesive bond is required, rather than intermittent failure.

[0014] For example, patent application FR3015984 describes a self-adhesive article comprising a conformable foam-type support layer obtainable from an adhesive composition based on polyethers or silylated polyurethanes or on mixtures of specific silylated polyethers or polyurethanes.

[0015] These self-adhesive articles are described as being capable of bonding to many surfaces, including plastic materials or surfaces that have properties comparable to the substrate layer.

[0016] However, it has been found that the adhesive compositions described in these applications are not entirely satisfactory and that there is room for improvement with respect to adhesive performance or bonding effectiveness on low surface energy surfaces.

[0017] However, in some areas of PSA application, it is not desirable to use the above-mentioned surface treatments to offset the poor adhesive performance of the adhesive composition on these substrates.In fact, one of the drawbacks of these treatments is that they require additional steps in the manufacturing process for the products to which the self-adhesive article is attached, thereby generating additional costs and limiting the manufacturing lines of these products.In addition, by modifying the physicochemical properties of the substrate surface, these treatments can weaken the substrate surface or induce aesthetically undesirable effects such as loss of transparency or change in the surface color of the substrate, which can be problematic when the support layer of the self-adhesive article is, for example, transparent or translucent, since the substrate surface is visible.These treatments can also result in uneven surfaces and short-lasting bonds with poor reproducibility, which may require repeated treatment of the substrate surface before fixing the adhesive part of the self-adhesive article.

[0018] Therefore, in recent years, new self-adhesive bonding solutions have emerged that are suitable for bonding to low surface energy substrates and are adapted for the production of self-adhesive labels.

[0019] For example, pressure-sensitive adhesive compositions based on acrylate polymers (or copolymers) are known, such as those described in 3M patent application EP2310470.

[0020] However, the preparation of these polymers and their use in formulating adhesive compositions requires the use of large amounts of solvents, which has proven to be burdensome, as the production of self-adhesive articles requires the removal of the solvent and / or the installation of special equipment in some cases. In addition, the use of acrylic polymers also has the drawback of producing an unpleasant odor due to the presence of residual monomers or solvents.

[0021] Thus, there is a need to develop new pressure-sensitive adhesive compositions that can bond to any surface, including low surface energy substrates that are known to be difficult to bond to, without exhibiting any and all of the drawbacks of the prior art.

[0022] It has been discovered that compositions according to the present application allow for more effective bonding to all types of surfaces, including low surface energy substrates, regardless of the surface condition.

[0023] In particular, the adhesive compositions according to the invention have improved adhesive performance, particularly with respect to cohesion, on low surface energy substrate surfaces under comparable surface conditions, relative to prior art pressure-sensitive adhesive compositions based on crosslinked, disilylated polymers alone (i.e., no monosilylated polymers).

[0024] In particular, the adhesive compositions according to the invention have excellent adhesive performance for bonding the surfaces of substrates based on crosslinked, low surface energy plastics, preferably at least comparable to the performance measured for current acrylic-type self-adhesive solutions.

[0025] In particular, the adhesive compositions according to the invention have, in the crosslinked state, an adhesive strength, measured according to a peel test at 180°, of at least 3 N / cm, preferably at least 3.5 N / cm, more preferably at least 4 N / cm on substrates having a surface energy of 40 mN / m or less, in particular on plastic substrates of the polyolefin type such as HDPE and PP.

[0026] In particular, the adhesive composition according to the invention allows the production of self-adhesive articles that are capable of bonding quickly and permanently to such surfaces.

[0027] In particular, the adhesive composition according to the invention is easy to use and also makes it possible to produce self-adhesive articles on high speed production lines.

[0028] In this application, the term low surface energy substrate refers to a substrate having a surface energy of 40 milliNewtons per meter (mN / m) or 40 millijoules per square meter (mJ / m), measured in air at 1 bar atmospheric pressure, 23°C and 50% relative humidity. 2 ) means a substrate comprising at least one surface having a surface energy of: The surface energy of a substrate can be quantified by methods well known to those skilled in the art from contact angle measurements and can be calculated according to the Owens & Wendt model.

[0029] Low surface energy substrates to which the adhesive of the present invention is intended to be applied preferably have a surface energy of 23 to 38 mN / m (or mJ / m 2 ), more preferentially having a surface energy of 25 to 35 mN / m. Summary of the Invention

[0030] Therefore, the present invention first provides: A.1) at least 4% by weight of one or more polysilylated polymers having a number average molecular weight (Mn) of at least 6000 g / mol, selected from polymers comprising a polyether and / or polyurethane backbone and at least two hydrolyzable silylated end groups attached to the polymer backbone by a urethane or ether functional group, A.2) at least 13% by weight of one or more monosilylated polymers having an average molecular weight (Mn) of at least 1000 g / mol, selected from polymers comprising a polyether and / or polyurethane backbone and hydrolyzable silylated end groups attached to the polymer backbone by a urethane or ether functionality, B) at least 25% by weight of one or more tackifying resins having a hydroxyl index of 100 or less, preferably 50 or less, and more preferably equal to zero; C) at least 0.2% of a crosslinking catalyst; The adhesive composition comprises: The contents in wt. % are expressed relative to the total weight of the adhesive composition, the sum of the contents of all ingredients of the adhesive composition being 100%.

[0031] According to one embodiment, the polysilylated polymer A.1) corresponds to the following formula (I) or (II) or a mixture thereof, preferably to formula (II):

[0032] According to one embodiment, the monosilylated polymer A.2) corresponds to the following formula (Ibis) or (IIbis) or a mixture thereof, preferably to formula (IIbis):

[0033] According to a more preferred embodiment, the polysilylated polymer A.1) corresponds to formula (II) and the monosilylated polymer A.2) corresponds to formula (IIbis).

[0034] According to one embodiment, the linking group is a urethane group.

[0035] According to one embodiment, the polysilylated polymer A.1) has a number average molecular weight (Mn) of 6000 to 55,000 g / mol, preferably 15,000 to 50,000 g / mol, more preferably 25,000 to 45,000 g / mol.

[0036] According to one embodiment, the monosilylated polymer A.2) has a number average molecular weight (Mn) of 1000 to 55,000 g / mol, preferably 2,000 to 45,000 g / mol, more preferably 3,000 to 35,000 g / mol.

[0037] According to one embodiment, the tackifying resin has a hydroxyl index that is substantially close to, and preferably equal to, zero.

[0038] According to one embodiment, the tackifying resin has a softening point in the range of from 0°C to 140°C, more preferably from 50°C to 130°C, more preferably from 70°C to 120°C.

[0039] According to one embodiment, the tackifying resin has a number average molecular weight ranging from 100 to 6000 g / mol, more preferably from 300 to 4000 g / mol.

[0040] According to one embodiment, the tackifying resin is selected from: (i) Resins obtained by polymerization or copolymerization, optionally with hydrogenation, of a mixture of unsaturated aliphatic and / or aromatic hydrocarbons containing approximately 5, 9 or 10 carbon atoms derived from petroleum fractions; (ii) Resins obtained by a process involving the polymerization of alpha-methylstyrene or copolymerization of alpha-methylstyrene with other hydrocarbon monomers; (iii) Rosin of natural origin or modified rosin, such as rosin extracted from pine resin, wood rosin extracted from tree roots, and their derivatives that are hydrogenated, dimerized, polymerized, or esterified with mono- or polyalcohols, such as glycerol or pentaerythritol; and (iv) Mixtures thereof.

[0041] According to one embodiment, the adhesive composition of the present invention comprises: A.1) 5 to 59.8 wt. % of one or more polysilylated polymers as defined above; A.2) 15 to 69.8 wt. % of one or more monosilylated polymers as defined above; B) 25 to 79.8 wt. % of one or more tackifying resins as defined above; and C) 0.2 to 4% crosslinking catalyst Including, The contents in % by weight are expressed relative to the total weight of the adhesive composition, the sum of the contents of all ingredients of the adhesive composition being equal to 100%.

[0042] The present invention secondly relates to a self-adhesive article comprising a substrate coated with a self-adhesive layer comprising the adhesive composition according to the invention in a crosslinked state.

[0043] According to one embodiment, the self-adhesive article is a self-adhesive multi-layer system, in particular a label or a self-adhesive tape.

[0044] The present invention thirdly relates to a product in which the self-adhesive article according to the invention adheres to a surface having a surface energy of 40 mN / m or less, preferably in the range of 23 to 38 mN / m, more preferably 25 to 35 mN / m, measured in air at 23°C, 50% relative humidity and 1 bar atmospheric pressure.

[0045] According to one embodiment, the surface of the product to which the self-adhesive article according to the invention is attached is based on plastic, preferably polyolefins, such as polyisoprene (PI), polyisobutylene (PIB), polyethylene (PE), polypropylene (PP) and copolymers thereof, in particular HDPE and PP.

[0046] The surface of the product to which the self-adhesive article according to the invention is attached can also be based on cyclic olefin polymers, such as those obtained by ring-opening metathesis polymerization (ROMP).

[0047] The use of at least one monosilylated polymer used according to the invention in an adhesive composition comprising at least one polysilylated polymer, at least one tackifying resin and at least one crosslinking catalyst, preferably as described in the present application, leads to an adhesive, after crosslinking, having an adhesive strength, measured according to a peel test at 180° (carried out in accordance with FINAT Standard No. 1), of at least 3 N / cm on low surface energy substrates, in particular on plastic bases such as those mentioned above, such as PE and PP.

[0048] In particular, the use of at least one monosilylated polymer used according to the invention in an adhesive composition comprising at least one polysilylated polymer, at least one tackifying resin and at least one crosslinking catalyst, preferably as described in the present application, makes it possible to obtain an adhesive having, after crosslinking, an adhesive strength, measured according to a peel test at 180° on PP (carried out in accordance with FINAT Standard No. 1), of at least 4 N / cm. DETAILED DESCRIPTION OF THE INVENTION

[0049] In this patent application, unless otherwise stated: - Viscosity was measured at 23°C using a Brookfield RTV viscometer with a rotation speed appropriate for the needle and sensor sensitivity. The average molecular weight of the tackifying resin (expressed in g / mol or Daltons) can be determined by methods well known to those skilled in the art, for example by gel permeation chromatography (GPC) using polystyrene standards. The average molecular weight of the silylated polymer (expressed in g / mol or Daltons) can be determined by methods well known to those skilled in the art, for example by NMR 1H / 13C and / or by calculation based on the molar amounts of reagents used and / or by gel permeation chromatography (GPC), for example using polystyrene standards. - Hydroxyl Index is the number of hydroxyl functional groups per gram of tackifying resin, and is expressed in this application as the equivalent number of milligrams of potassium per gram of tackifying resin (mg KOH / g) for the assay of hydroxyl functional groups. - The surface energy of the material or substrate was measured in air at 23°C, 50% relative humidity and 1 bar atmospheric pressure. - The adhesive strength (or peel strength) was measured by the peel test at 180° described in the examples. The reference test was FINAT Standard No. 1, the exposure time of the item on the carrier to be tested was 20 minutes and the basis weight of the deposited adhesive was 50 g / m 2 is. - polysilylated polymers A.1) are polymers which have at least two hydrolyzable silyl groups, such as: Monosilylated polymers A.2) are polymers which contain a single hydrolyzable silyl group, such as: - "less" or "greater" when not followed by the term "or equal to" means "strictly less than" and "strictly more than," respectively. The various embodiments described herein may be used alone or in combination.

[0050] adhesive composition Polysilylated Polymers A.1) The adhesive composition according to the invention comprises at least one polysilylated polymer A.1) having a number average molecular weight (Mn) of at least 6000 g / mol, selected from polymers comprising a polyether and / or polyurethane backbone and at least two hydrolyzable silylated end groups attached to the polymer backbone by urethane or ether functional groups.

[0051] According to a first embodiment of the polysilylated polymer A.1), the polysilylated polymer A.1) is of the polyether type comprising at least two end groups, each of which is linked to a hydrolyzable silylated end group by an ether function. According to this embodiment, the polysilylated polymer A.1) can be obtained by a preparation process comprising: - in a first step, preparing a polyether with at least two allyl ether end groups (-O-CH2-CH2EC); then - in a second step, reacting the polyether obtained at the end of the first step with at least one silane bearing a SiH group in a quantity sufficient to cause each of the -O-CH2-CH=CH2 end groups of the polyether to react with the SiH group of the silane by hydrosilylation in the presence of a platinum catalyst; wherein the number average molecular weight (Mn) of the polyether obtained after the first step must be high enough to obtain, after reaction with the silane compound, a polysilylated polymer A.1) of the desired Mn.

[0052] According to a second embodiment of the polysilylated polymer A.1), the polysilylated polymer A.1) is of the polyurethane type comprising at least two end groups, each of which is linked to a hydrolyzable silylated end group by a urethane function. According to this embodiment, the polysilylated polymer A.1) can be obtained by a preparation process comprising: - in a first step, preparing a polyurethane having at least two OH end groups; then - in a second step, reacting said polyurethane with at least one isocyanate silane having an NCO group in a quantity sufficient to react each of the OH end groups of the polyurethane with an NCO group of the isocyanate silane; wherein the number average molecular weight (Mn) of the polyurethane obtained after the first step must be high enough to obtain, after reaction with the isocyanate silane compound, a polysilylated polymer A.1) of the desired Mn.

[0053] Polyurethanes having at least two OH end groups can be obtained by polyaddition of a stoichiometric excess of at least one polyether polyol with at least one diisocyanate, in a manner well known to those skilled in the art. Preferably, the polyether polyol is a polyether diol.

[0054] In a first step, it is also possible to mix with the polyether polyol at least one chain extender having two groups independently selected from OH and primary and secondary amines, respectively, The chain extender is different from the polyether polyols used to prepare the polyurethanes and generally has a molecular weight of less than 300 g / mol.

[0055] The amounts of polyether polyol, diisocyanate, and optionally chain extender used are adjusted in a manner well known to those skilled in the art in order to obtain a polyurethane having two OH end groups at the end of the first step, and furthermore, these amounts are such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups to which the possible primary and secondary amine functional groups are added (expressed as r2.1) is strictly less than 1.

[0056] The amount of isocyanatosilane used is adjusted in a manner well known to those skilled in the art in order to obtain, at the end of the second step, a polysilylated polymer A.1), and this amount is such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups (denoted r2.2) among which primary and secondary amine functional groups may be present, is close to 1, i.e., between 0.95 and 1.05.

[0057] The preparation of the polysilylated polymer A.1) is preferably carried out in the presence of at least one reaction catalyst, in particular any catalyst that can accelerate the reaction and make the preparation process take place in the first and / or second step.

[0058] According to a third embodiment of the polysilylated polymer A.1), the polysilylated polymer A.1) is of the polyether type, comprising at least two end groups, each of which is linked to a hydrolyzable silylated end group by a urethane functional group. According to this embodiment, the polysilylated polymer A.1) can be obtained by reacting at least one polyether polyol with at least one isocyanatosilane containing NCO groups in an amount sufficient to react each of the OH end groups of the polyether polyol with an NCO group of the isocyanatosilane; the number average molecular weight (Mn) of the polyether polyol used must be high enough to obtain the polysilylated polymer A.1) of the desired Mn after reaction with the isocyanatosilane.

[0059] It is also possible to mix at least one of the chain extenders described above with the polyether polyol.

[0060] The amount of isocyanate silane used is adjusted in a manner well known to those skilled in the art to obtain polysilylated polymers A.1), such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups (denoted r3) in which primary and secondary amine functional groups may be present is close to 1, i.e., between 0.95 and 1.05.

[0061] The preparation of the polysilylated polymer A.1) is preferably carried out in the presence of at least one reaction catalyst. In particular, it is possible to use any catalyst that is capable of accelerating the reaction and bringing about the above-described preparation process.

[0062] Preferably, the polysilylated polymer A.1) has the following formula: - Formula (I): TIFF0007749310000001.tif24170[In the formula, - B represents a divalent (f=2) or trivalent (f=3) linear, branched, cyclic, alicyclic or aromatic saturated or unsaturated hydrocarbon radical containing from 2 to 66 carbon atoms and optionally containing one or more heteroatoms, such as O, N, -R 3 represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, - R' 2 represents a linear or branched divalent alkylene group containing 2 to 4 carbon atoms, -R 4 and R 5 are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R 4 may optionally be joined to a ring, preferably R 4 is a methyl group, - n'' is the expression -[OR' 2 ] n’’ is a non-zero integer such that the number average molecular weight of the polyether block is in the range of 150 g / mol to 20,000 g / mol, p is an integer equal to 0 or 1, - f is an integer equal to 2 or 3, the indices n" and f are such that the number average molecular weight of the polymer A.1) is at least 6000 g / mol] - Formula (II): TIFF0007749310000002.tif29170[In the formula, - B represents a divalent (f=2) or trivalent (f=3) linear, branched, cyclic, alicyclic or aromatic saturated or unsaturated hydrocarbon radical containing from 2 to 66 carbon atoms and optionally containing one or more heteroatoms, such as O, N, -R 1 represents a divalent hydrocarbon group containing 5 to 15 carbon atoms, which may be aliphatic or aromatic, linear, branched or cyclic; -R 3 represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, -R 2 and R' 2 are the same or different and each represent a linear or branched divalent alkylene group containing 2 to 4 carbon atoms; -R 4 and R 5are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R 4 may optionally be joined to a ring, preferably R 4 is a methyl group, - n is the formula -[OR 2 ] n is a non-zero integer such that the number average molecular weight of the polyether block is in the range of 300 g / mol to 40,000 g / mol, - n' is the expression -[OR' 2 ] n’ is a zero or non-zero integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 20,000 g / mol, m is a zero or non-zero integer, p is an integer equal to 0 or 1, - f is an integer equal to 2 or 3, the indices m, n, n' and f are such that the number average molecular weight of the polymer A.1) is at least 6000 g / mol] or a mixture thereof.

[0063] In formula (I) and / or (II), preferably, -R 2 and / or R' 2 are the same or different and each represent a linear or branched divalent propylene group, for example a divalent isopropylene group; - n is the formula -[OR 2 ] n is an integer such that the number average molecular weight of the polyether block ranges from 6000 g / mol to 25,000 g / mol, - n' is the expression -[OR' 2 ] n’ is an integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 12,500 g / mol.

[0064] More preferentially, -R 2and / or R' 2 are the same and each represent a divalent isopropylene group, - n is the formula -[OR 2 ] n - is an integer such that the number average molecular weight of the polyether block ranges from 8000 g / mol to 20,000 g / mol, and - n' is the expression -[OR' 2 ] n’ is an integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 10,000 g / mol.

[0065] Preferably, R 3 represents a linear or branched divalent alkylene group containing from 1 to 3 carbon atoms, and more preferentially represents a divalent methylene or n-propylene group.

[0066] Preferably, when p is equal to 1, R 4 represents a methyl group.

[0067] Preferably, R 5 represents a methyl or ethyl group.

[0068] According to one embodiment, the adhesive composition comprises a blend of polysilylated polymers A.1) of formula (I) and / or (II). Preferably, the adhesive composition comprises a blend of polysilylated polymers A.1) comprising at least one polysilylated polymer of formula (I) or (II) such that p=0 and at least one polysilylated polymer of formula (I) or (II) such that p=1. More preferentially, the adhesive composition comprises a blend of polysilylated polymers A.1) comprising at least one polysilylated polymer of formula (II) such that p=0 and at least one polysilylated polymer of formula (II) such that p=1.

[0069] Preferably, the silylated polymer A.1) is disilylated.

[0070] Preferably, the silylated polymer A.1) corresponds to formula (II):

[0071] According to a preferred embodiment, the polysilylated polymer A.1) is a disilylated polymer corresponding to formula (II) where f=2 and m is not zero. It has been found that the use of disilylated polymer A.1) of formula (II) according to this embodiment leads to improved adhesive performance, especially for PE and PP.

[0072] According to an even more preferred embodiment, the polysilylated polymer A.1) is a disilylated polymer corresponding to formula (II) where f=2, m is not zero and p=1. In particular, it has been found that the use of disilylated polymer A.1) of formula (II) according to this embodiment leads to improved adhesive performance, especially to PP.

[0073] Preferably, the polysilylated polymer A.1) has a number average molecular weight (Mn) of 6000 to 55,000 g / mol, more preferably 15,000 to 50,000 g / mol, even more preferably 25,000 to 45,000 g / mol. The indices in the above formulas (I) and (II) are preferably such that the number average molecular weight (Mn) of the polysilylated polymer A.1) varies within these values.

[0074] In particular, it was observed that the use of higher Mn disilylated polymer A.1) in a mixture of polymers A.1) and A.2) leads to improved adhesive performance towards PE and PP for the same type of polymer.

[0075] The polysilylated polymer A.1) represents at least 4% by weight of the adhesive composition according to the invention, preferably from 5 to 59.8% by weight, more preferably from 15 to 54.8% by weight, even more preferably from 20 to 44.8% by weight, relative to the total weight of the adhesive composition.

[0076] Monosilylated polymer A.2) The adhesive composition according to the invention comprises at least one monosilylated polymer A.2) having a number average molecular weight (Mn) of at least 1000 g / mol, selected from polymers comprising a polyether and / or polyurethane backbone and hydrolyzable silylated end groups attached to the polymer backbone by urethane or ether functional groups ("linking groups").

[0077] According to a first embodiment of the monosilylated polymer A.2), the monosilylated polymer A.2) is of the polyether type, one of the two end groups of which is linked to a hydrolyzable silylated end group by means of an ether function.

[0078] According to this embodiment, the monosilylated polymer A.2) can be obtained by a preparation process comprising: in a first step, a compound of structure (IIIa): TIFF0007749310000003.tif25170[In the formula, -R 0 represents a divalent hydrocarbon group containing 1 to 60 carbon atoms, which may be aliphatic, aromatic or alkylaromatic, linear, branched or cyclic; - n''' is the expression -[OR' 2 ] n’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 20,000 g / mol, and - R' 2 is as mentioned above] preparing an alkyl (poly)ether group having an allyl ether end group of - in a second step, reacting said compound of formula (IIIa) with at least one silane bearing a SiH group in an amount sufficient to react each of the -O-CH2-CH=CH2 end groups of the polyether monoallyl ether with the SiH group of the silane by hydrosilylation; wherein the number average molecular weight (Mn) of the polyether monoallyl ether obtained after the first step must be high enough to obtain, after reaction with the silane compound, a monosilylated polymer A.2) of the desired Mn.

[0079] According to a second embodiment of the monosilylated polymer A.2), the monosilylated polymer A.2) is a polyurethane, one of the two end groups of which is linked to a hydrolyzable silylated end group by a urethane function. According to this embodiment, the monosilylated polymer A.2) can be obtained in situ during the synthesis of the polysilylated polymer A.1) by a preparation method comprising: - in a first step, preparing a mixture comprising a polyurethane with a single OH end group and a polyurethane containing two OH end groups; then - in a second step, reacting the polyurethane mixture obtained in the first step with at least one isocyanatosilane having an NCO group in an amount sufficient to react all of the OH end groups of the polyurethane mixture with the NCO groups of the isocyanatosilane; the number-average molecular weight (Mn) of the polyurethane obtained after the first step must be high enough to obtain, after reaction with the silane compound, polysilylated polymer A.1) and monosilylated polymer A.2) of the desired Mn.

[0080] Polyurethane mixtures having two OH end groups and one OH end group, respectively, can be obtained in a manner well known to those skilled in the art by polyaddition of mixtures of polyether diols and monools with a stoichiometric excess of at least one diisocyanate.

[0081] The polyether diols and diisocyanates which can be used to prepare the polyurethanes containing two OH end groups can be selected from those described in the second embodiment of the polysilylated polymers A.1).

[0082] A monol that can be used for the in-situ synthesis of polyurethanes containing a single OH end group has the following structure (IIIb): TIFF0007749310000004.tif26170 to obtain a polyurethane containing a single OH end group of sufficient number average molecular weight. 0 and R' 2 is as defined in formula (IIIa), and n''' is a group of formula -[OR' 2 ] n’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 20,000 g / mol.

[0083] The chain extender can be added in a first step in a mixture with the polyether diol and monol.

[0084] The chain extender may be selected from those described in the first embodiment.

[0085] The amounts of polyether diol, monool and, optionally, chain extender used are adjusted in a manner well known to those skilled in the art in order to obtain, at the end of the first step, a mixture comprising polyurethanes with a single OH end group and polyurethanes with two OH end groups. Furthermore, these amounts are such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups to which the possible primary and secondary amine functional groups are added (expressed as r2.1) is strictly less than 1.

[0086] The amount of isocyanatosilane used is adjusted in a manner well known to those skilled in the art in order to obtain, at the end of the second step, a mixture of polysilylated polymer A.1) and monosilylated polymer A.2), and moreover, this amount is such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups (denoted r2.2) among which primary and secondary amine functional groups may be present, is close to 1, i.e., between 0.95 and 1.05.

[0087] The preparation of the mixture of polysilylated polymer A.1) and monosilylated polymer A.2) is preferably carried out in the presence of at least one reaction catalyst, in particular any catalyst that can accelerate the reaction and make the preparation process take place in the first and / or second step.

[0088] According to a third embodiment of the monosilylated polymer A.2), the monosilylated polymer A.2) is a polyether in which one of the two end groups is linked to a hydrolyzable silylated end group by a urethane functional group. According to this embodiment, the monosilylated polymer A.2) has the structure (IIIb) defined below: TIFF0007749310000005.tif26170 with at least one isocyanatosilane having a sufficient number of NCO groups to allow each OH group of compound (IIIb) to react with the NCO of the isocyanatosilane, the number average molecular weight of the polyether monool being selected so as to obtain a monosilylated polymer A.2) of the desired Mn. In formula (IIIb), R 0 and R' 2 is as defined in formula (IIIa), and n''' is a group of formula -[OR' 2 ] n’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 20,000 g / mol.

[0089] The amount of isocyanatosilane used is adjusted in a manner well known to those skilled in the art to obtain a monosilylated polymer A.2), such that the molar ratio of the number of NCO functional groups to the total number of OH functional groups (denoted r2.2) that may be present, primary and secondary amine functional groups, is close to 1, i.e., between 0.95 and 1.05.

[0090] The preparation of the mixture of polysilylated polymer A.1) and monosilylated polymer A.2) is preferably carried out in the presence of at least one reaction catalyst, in particular any catalyst that can accelerate the reaction and make the preparation process take place in the first and / or second step.

[0091] Preferably, the monosilylated polymer A.2) has the following formula: - Formula (Ibis): TIFF0007749310000006.tif27170[In the formula, -R 0 represents a divalent hydrocarbon group containing 1 to 60 carbon atoms, which may be aliphatic, aromatic or alkylaromatic, linear, branched or cyclic; -R 3 represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, - R' 2 represents a linear or branched divalent alkylene group containing 2 to 4 carbon atoms, -R 4 and R 5 are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R 4 may optionally be joined to a ring, preferably R 4 is a methyl group, - n''' is the expression -[OR' 2 ] n’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether block ranges from 0 g / mol to 20,000 g / mol, p is an integer equal to 0, 1 or 2; -R 0 and n''' is such that the number average molecular weight of polymer A.2) is at least 1000 g / mol] Formula (IIbis): TIFF0007749310000007.tif30170[In the formula, -R 0represents a divalent hydrocarbon group containing 1 to 60 carbon atoms, which may be aliphatic, aromatic or alkylaromatic, linear, branched or cyclic; -R 1 represents a divalent hydrocarbon group containing 5 to 15 carbon atoms, which may be aliphatic or aromatic, linear, branched or cyclic; -R 3 represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, -R 2 and R' 2 are the same or different and each represent a linear or branched divalent alkylene group containing 2 to 4 carbon atoms; -R 4 and R 5 are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R 4 may optionally be joined to a ring, preferably R 4 is a methyl group, - n is the expression -[OR' 2 ] n is an integer such that the number average molecular weight of the polyether block ranges from 300 g / mol to 40,000 g / mol, - n''' is the expression -[OR' 2 ] n’’’ the number average molecular weight of the polyether blocks is a zero or non-zero integer ranging from 0 g / mol to 20,000 g / mol, m is a zero or non-zero integer, p is an integer equal to 0, 1 or 2; -R 0 and the indices m, n and n''' are such that the number average molecular weight of the polymer A.2) is at least 1000 g / mol] or a mixture thereof.

[0092] Preferably, p is an integer equal to 0 or 1, and more preferably, p is equal to 1.

[0093] Preferably, the monosilylated polymer A.2) corresponds to formula (IIbis):

[0094] Preferably, the monosilylated polymer A.2) corresponds to formula (IIbis) where p=1.

[0095] Preferably, the monosilylated polymer A.2) has a number average molecular weight (Mn) of 1000 to 55,000 g / mol, preferably 2,000 to 45,000 g / mol, more preferably 3,000 to 35,000 g / mol. 0 and the indices of the above formulae (Ibis) and (IIbis) are preferably such that the number average molecular weight (Mn) of the monosilylated polymer A.2) varies within these values.

[0096] The monosilylated polymer A.2) represents at least 13% by weight of the total weight of the adhesive composition according to the invention, preferably from 15 to 69.8% by weight, more preferably from 15 to 54.8% by weight, even more preferably from 20 to 44.8% by weight, relative to the total weight of the adhesive composition.

[0097] In particular, it has been observed that the use of a higher content of monosilylated polymer A.2) in a mixture of polymers A.1) and A.2) leads to improved adhesive performance towards PE and PP.

[0098] For other blends of polysilylated polymers A.1) and monosilylated polymers A.2) as described above, mixtures of formulae (II) and (IIbis) are preferred.

[0099] These alternative adhesive compositions provide better adhesive performance to polyolefin-type substrates such as PE and PP, especially HDPE and PP, more preferably PP.

[0100] The adhesive compositions according to these alternative forms have an adhesive strength, measured by a peel test at 180° (according to FINAT Standard No. 1), of at least 3 N / cm, more preferably at least 3.5 N / cm, even more preferably at least 4 N / cm on PE, in particular HDPE.

[0101] The adhesive compositions according to these alternative forms have an adhesive strength, measured by a peel test at 180° (according to FINAT Standard No. 1), of 4 N / cm or preferably 5 N / cm or more, more preferably 6 N / cm or more, even more preferably 7 N / cm on PP.

[0102] The above preparation methods for polysilylated polymer A.1 and monosilylated polymer A.2 were carried out under anhydrous conditions to avoid hydrolysis of the hydrolyzable silyl groups, and the use of these polymers is likewise preferably carried out under such conditions.

[0103] Tackifying resin B) The tackifying resins B) used in the adhesive compositions according to the invention are compatible with the polysilylated polymers A.1) and monosilylated polymers A.2).

[0104] By "compatible tackifying resin" is meant a tackifying resin that when mixed with polysilylated polymer A.1) and monosilylated polymer A.2) in a 50 / 50 wt. % ratio results in a substantially homogeneous blend.

[0105] The tackifying resins B) (each) preferably have a hydroxyl index of 50 or less, or preferably substantially close to zero, even more preferably zero.

[0106] Preferably, the tackifying resins (each) have a softening point in the range of from 0°C to 140°C, more preferably from 50°C to 130°C, more preferably from 70°C to 120°C.

[0107] Preferably, the tackifying resin has a number average molecular weight in the range of from 100 to 6000 g / mol, more preferably from 300 to 4000 g / mol.

[0108] Preferably, the tackifying resin is selected from: (i) Resins obtained by polymerization or copolymerization, optionally by hydrogenation, of mixtures of unsaturated aliphatic and / or aromatic hydrocarbons containing approximately 5, 9 or 10 carbon atoms derived from petroleum fractions; (ii) Resins obtained by a process involving the polymerization of alpha-methylstyrene or copolymerization of alpha-methylstyrene with other hydrocarbon monomers; (iii) Rosin of natural origin or modified rosin, such as rosin extracted from pine resin, wood rosin extracted from tree roots, and their derivatives that are hydrogenated, dimerized, polymerized, or esterified with mono- or polyalcohols, such as glycerol or pentaerythritol; and (iv) Mixtures thereof.

[0109] According to a preferred embodiment, the tackifying resin B) is a tackifying resin of type (i) or a mixture of tackifying resins comprising at least one tackifying resin of type (i) and / or (ii). Even more preferably, the tackifying resin B) is a mixture of tackifying resins comprising at least one tackifying resin of type (i) and (ii). In particular, it has been found that the use of a mixture of tackifying resins comprising at least one resin of type (i), preferably a mixture comprising at least one resin of type (i) and (ii), according to this embodiment, results in improved adhesive performance, especially at least for PP.

[0110] Such resins are commercially available. These include, for example, the following products: - resins of type (i): PICCO®-AR-100 (available from Eastman), obtained by polymerization of a mixture of aromatic hydrocarbons containing 9 carbon atoms, mainly derived from petroleum fractions, with zero OHI, a number average molecular weight of 600 g / mol and a softening point of 100°C; or PICCO® AR-85 (available from Eastman), obtained by polymerization of a mixture of aromatic hydrocarbons containing mainly 9 carbon atoms, with zero OHI, a number average molecular weight of 520 g / mol and a softening point of 85°C; NORSOLENE® M1090 (available from Cray Valley), a modified aromatic aliphatic resin with zero OHI and a softening point of 90°C; or PICCO® A-10 (available from Eastman), with a number average molecular weight of 420 g / mol and liquid at room temperature; - resins of type (ii): NORSOLENE® W110 (available from Cray Valley), obtained by polymerization of alpha-methylstyrene without the action of phenol, with zero OHI, a number-average molecular weight of 750 g / mol and a softening point of 110°C; NORSOLENE® W85 (available from Cray Valley), an alpha-methylstyrene resin with zero OHI, a number-average molecular weight of 600 g / mol and a softening point of 85°C; - Type (iii) resin: Sylvalite® RE 100 (available from Arizona Chemical), a rosin and pentaerythritol ester, with 50 mg KOH / g OHI, a number average molecular weight of 974 g / mol and a softening point of 100°C.

[0111] The content of tackifying resin B) is at least 25% by weight of the total weight of the adhesive composition according to the invention, preferably from 15 to 79.8% by weight, more preferably from 30 to 69.8% by weight, even more preferably from 35 to 59.8% by weight, relative to the total weight of the adhesive composition.

[0112] Crosslinking catalyst The crosslinking catalyst that can be used in the composition according to the present invention can be any catalyst known to those skilled in the art for silanol condensation.Examples of such catalysts include organotitanium derivatives such as titanium acetylacetonate (available from DuPont under the trade name TYZOR® AA75), aluminum chelates such as aluminum chelates (available from KING INDUSTRIES under the trade name K-KAT® 5218), or amines such as 1,8-diazabicyclo(5.4.0)undecene-7 or DBU.

[0113] The content of crosslinking catalyst C) ranges from 0.2 to 4% by weight, relative to the total weight of the adhesive composition.

[0114] According to one embodiment, the adhesive composition of the present invention comprises: - at least 5% by weight of one or more polysilylated polymers A.1); - at least 15% by weight of one or more monosilylated polymers A.2); - 25 to 79.8% by weight of one or more tackifying resins; and C) 0.2 to 4% by weight of at least one crosslinking catalyst Including, The content of silylated polymers A.1) and A.2) represents from 20 to 74.8% by weight, relative to the total weight of the adhesive composition.

[0115] In an even more preferred embodiment, the composition according to the invention comprises: - at least 15% by weight of one or more disilylated polymers A.1); - at least 15% by weight of one or more monosilylated polymers A.2); - 30 to 69.8% by weight of one or more tackifying resins; and C) 0.2 to 4% by weight of at least one crosslinking catalyst Including, The content of silylated polymers A.1) and A.2) represents from 30 to 69.8% by weight, relative to the total weight of the adhesive composition.

[0116] In an even more preferred embodiment, the adhesive composition according to the invention comprises - at least 20% by weight of one or more disilylated polymers A.1); - at least 20% by weight of one or more monosilylated polymers A.2); - 35 to 59.8% by weight of one or more tackifying resins; and C) 0.2 to 4% by weight of at least one crosslinking catalyst Including, The content of silylated polymers A.1) and A.2) represents from 40 to 64.8% by weight, relative to the total weight of the adhesive composition.

[0117] The adhesive composition according to the invention may or may not comprise, in combination with the blend of polysilylated A.1) and monosilylated A.2) polymers, at least one thermoplastic polymer selected from those used to prepare HMPSA, such as ethylene vinyl acetate (EVA), or styrene block copolymers (such as SIS, SBS, SIBS, SEBS, SEPS and their derivatives, including grafted maleic anhydride), where these thermoplastic polymers are not silylated.

[0118] The adhesive composition according to the invention may or may not contain at least one non-polymeric hydrolyzable alkoxysilane derivative having a molar mass of less than 500 g / mol, preferably a trimethoxysilane derivative, as a desiccant. Such an agent advantageously extends the shelf life of the adhesive composition according to the invention during storage and transportation before use. Such an agent includes, for example, gamma-methacryloxypropyltrimethoxysilane, which is commercially available from Momentive under the trade name SILQUEST® A-174. The amount of desiccant can be up to 3% by weight, based on the weight of the adhesive composition.

[0119] The composition according to the invention may or may not comprise at least one plasticizer, such as a phthalate or benzoate, a paraffinic and naphthenic oil (e.g. Primol® 352 from ESSO) or a homopolymer of polyethylene wax (e.g. AC® 617 from HONEYWELL), or a copolymer wax of polyethylene and vinyl acetate, or a pigment or dye, or a mixture of these compounds.

[0120] The adhesive composition according to the present invention may or may not contain a filler, and the filler content is preferably less than 15 wt. %, more preferably less than 10 wt. %, and even more preferably less than 1 wt. %, based on the weight of the adhesive composition.

[0121] Finally, preferably, 0.1 to 2% of one or more stabilizers (or antioxidants) are included in the adhesive composition according to the invention. These compounds are added to protect the composition against degradation caused by reaction with oxygen formed by the action of heat or light. These compounds scavenge free radicals and can include primary antioxidants, which are generally substituted phenols, such as Ciba's Irganox® 1076. Primary antioxidants can be used alone or in combination with other secondary antioxidants or UV stabilizers.

[0122] The adhesive composition according to the present invention can be prepared by a method comprising: a mixing step carried out under airtight conditions, preferably in an inert or reduced pressure atmosphere, in which the polysilylated A.1) and monosilylated A.2) polymers are blended with the tackifying resin B) at a temperature ranging from 40 to 170°C, preferably from 70 to 150°C; and then - at least one crosslinking catalyst C) and, optionally, at least one desiccant and one or more other optical components as described above are incorporated into said mixture at a temperature ranging from 40 to 90°C.

[0123] The adhesive composition according to the invention can be used for the manufacture of self-adhesive articles comprising a temporary or permanent backing layer and an adhesive layer obtained by crosslinking the adhesive composition.

[0124] The backing layer of the self-adhesive article obtained from the adhesive composition according to the invention can be a temporary or permanent backing layer.

[0125] When the backing layer is a temporary carrier, it is preferably a plastic film or a protective non-stick liner (a "release liner") designed so that once the item is attached to a surface, the adhered item contains only the adhesive layer and the temporary backing layer is removed.

[0126] By "non-tacky" is meant a material in which the adhesive composition according to the invention in the crosslinked state has an adhesive strength of less than 200 centiNewtons per centimeter (cN / cm), preferably less than 50 cN / cm, even more preferably less than 30 cN / cm, and even more preferably less than 10 cN / cm, as measured according to the FINAT 3 test, performed at a pulling speed of 300 mm / min and a pulling angle of 180°.

[0127] The release liner generally has a surface energy of less than 22 mN / m, more preferably less than 20 mN / m.

[0128] If the backing layer is permanent, it can be made from a material that can be used to manufacture pressure-sensitive or PSA items.

[0129] self-adhesive articles The present invention also relates to a self-adhesive article comprising a substrate coated with a self-adhesive layer comprising the adhesive composition according to the invention in a crosslinked state.

[0130] Within the meaning of the present invention, the term "self-adhesive article" includes any article that can be adhered to a surface only by applying manual pressure or using an instrument, without the use of additional glue or adhesive. The term "self-adhesive article" also includes the terms "pressure-sensitive adhesive item" or "PSA item". These items are intended to adhere to the surface to be adhered in order to close, support, attach, or simply fix, or to display shapes, logos, pictures, or information. These items can be used in many fields, such as the medical, clothing, packaging, automotive, and construction industries. Depending on their end use, they can be produced in the form of tapes, such as industrial or DIY tapes, or as single- or double-sided tapes, or as labels, bandages, dressings, patches, or graphic films, to attach objects to a work site.

[0131] According to one embodiment, the self-adhesive article is a self-adhesive multi-layer system, in particular a label or a self-adhesive tape, which may be single-sided or double-sided.

[0132] The support layer is sufficiently flexible to be wound into a roll and packaged, for example as described above.

[0133] Preferably, the support layer has an elongation at break that is greater than zero and strictly less than 100%. More preferably, the support layer has an elongation at break that is 50% or less, even more preferably 40% or less. Even more preferably, the support layer has an elongation at break that is 30% or less.

[0134] The elongation at break can be measured in the length or width direction at 23° C. according to ISO 1926. Preferably, the elongation at break is measured in the length direction.

[0135] The support layer can be based, for example, on acrylic polymers, polyethylene (PE), polypropylene (PP), oriented, non-oriented or biaxially oriented polyimides, polyurethanes, polyesters such as polyethylene terephthalate (PET) or paper.

[0136] Preferably, the support layer has a Young's modulus strictly greater than 300 MPa, more preferably 400 MPa or greater, even more preferably 500 MPa or greater.

[0137] According to one embodiment, the self-adhesive article obtained from the adhesive composition according to the invention comprises a permanent backing layer coated with an adhesive layer, which preferably also has a plastic or film liner, preferably siliconized.

[0138] Alternatively, the rear surface of the permanent backing layer that is not coated with the release liner, adhesive layer, may have a non-stick surface, such as a protective silicone layer.

[0139] The above two embodiments allow the self-adhesive article to be rolled up and then unrolled without any problems with adhesive transfer between the adhesive layer and the permanent backing layer.

[0140] According to one embodiment, the permanent support layer is coated on both sides with adhesive compositions which may be the same or different, at least one of the two adhesive compositions being according to the invention.

[0141] Preferably, the support layer has a thickness in the range of from 10 microns to 50 mm, more preferably from 10 microns to 20 mm, more preferably from 20 microns to 10 mm, more preferably from 20 microns to 1 mm.

[0142] In some cases, surface treatment of the backing layer is necessary to enhance bonding of the adhesive layer when applying a coating to it, especially when the surfaces of the support layer and the substrate to be bonded have the same surface energy.

[0143] The self-adhesive articles according to the invention can adhere to the surface of low surface energy substrates that have not been pretreated. These pretreatments are intended to chemically and / or physically modify the surface to increase its surface energy and / or roughness, thereby improving the adhesion of the adhesive layer to the surface. Examples of known surface treatments include plasma or corona treatment, polishing, or coating the surface with a chemical adhesive (also known as a primer) that can increase the surface energy of the substrate to which it is applied.

[0144] Thus, a self-adhesive article according to the present invention is capable of bonding two substrates, at least one of which has a low surface energy.

[0145] The substrate to which the self-adhesive article is to be attached (also referred to as the "substrate to be bonded") can be flexible or rigid.

[0146] In particular, it may have the same flexibility as the support layer described above, so that it can be wound and packaged, for example in the form of a roll, as described above.

[0147] Alternatively, the substrate to be bonded may be rigid, in which case it cannot be rolled up and packaged, for example in roll form as described above, without weakening.

[0148] The substrate to be bonded can be selected from low surface energy substrates such as polyolefin substrates, which are organic non-polar substrates or organic polar coatings such as varnishes, inks or paints, said substrates having a surface energy of less than 40 mN / m, preferably between 23 and 38 mN / m, more preferably between 25 and 35 mN / m.

[0149] Polyolefin-type substrates can be, for example, polymeric materials based on monomers and comonomers, such as polyethylene (PE), polypropylene (PP), polyisoprene (PI), polyisobutylene (PIB) and their copolymers (block or random), or based on cyclic olefin monomers, such as those obtained by ring-opening metathesis polymerization (ROMP).

[0150] Examples of polyethylene (PE) include, among others, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene, and linear very low density polyethylene.

[0151] Due to the adhesive bonding properties obtained by crosslinking the adhesive composition according to the invention, the self-adhesive articles according to the invention are able to bond low surface energy substrates, in particular those based on plastics, preferably those with polyolefins such as PE and PP, in particular HDPE, with an adhesive strength of at least 3 N / cm.

[0152] In particular, the self-adhesive article according to the invention is capable of bonding PP-based substrates with an adhesive strength of at least 4 N / cm.

[0153] According to one embodiment of the present invention, the self-adhesive article also includes a protective release liner.

[0154] According to one embodiment, the release liner is applied to the adhesive layer after crosslinking of the adhesive composition.

[0155] The support layer can be covered on one of its two surfaces, the backside, which is not coated with the adhesive layer, with a protective release liner, for example a silicone film, so that the self-adhesive article can be rolled up on itself and then easily unrolled due to the lack of adhesion of the adhesive layer to the silicone side.

[0156] The self-adhesive article according to the invention can be obtained by a method comprising the following steps: (a) packaging the adhesive composition according to the invention as described above at a temperature in the range of 20 to 130°C; then (b) coating the surface of a carrier with the adhesive composition obtained in step (a); and then (c) 1 m of gas 3 crosslinking the coated adhesive composition by heating to a temperature in the range of 20 to 200°C in a gaseous environment containing 10 to 200 mg of water molecules per 1000 g of adhesive; (d) laminating or transferring the crosslinked adhesive layer onto a backing layer or a non-stick release liner, which may be on the rear side of the carrier surface;

[0157] The "carrier surface" defined in the present invention should be understood to mean a carrier strip, or a release liner, or a support layer, covered by a non-stick protective film. The carrier surface is therefore intended to be part of the self-adhesive part, either as a release liner or a support layer.

[0158] If the carrier surface is not a support layer, the method for producing a self-adhesive article according to the present invention comprises a step (d) in which the crosslinked adhesive layer is transferred onto a support layer.

[0159] When the carrier surface is a support layer, the method for producing a self-adhesive article according to the present invention can include a step (d) in which the cross-linked adhesive layer is transferred onto the support layer.

[0160] According to a preferred alternative embodiment of the present invention, step (d) of the above method comprises transferring the crosslinked adhesive layer onto a flexible support layer (which may be a plastic film) after cooling the crosslinked adhesive layer to a temperature below the decomposition or softening temperature of the material comprising the support layer. According to this alternative embodiment, it is possible to produce self-adhesive articles comprising a support layer made of a temperature-sensitive material, for example a polyolefin-based material as described above.

[0161] In one embodiment, the self-adhesive article according to the invention can be obtained using the above-described method without a pretreatment step of the surface of the support layer. The purpose of these pretreatments is to chemically and / or physically modify the surface in order to increase the surface energy and / or the roughness of said surface, thus improving the adhesion of the adhesive layer to said surface. Examples of known surface treatments include plasma, corona or abrasive treatments, or coating the surface with a chemical adhesive (also known as a primer) that can increase the surface energy of the substrate to which it is applied.

[0162] According to one embodiment of the present invention, the adhesive layer has an adhesive strength on substrates with different surface energies of at least 3 N / cm, preferably at least 3.5 N / cm, more preferably at least 4 N / cm.

[0163] In particular, 50g / m 2 A self-adhesive article consisting of a support layer of a 50 μm thick polyethylene terephthalate (PET) film of grammage coated with an adhesive layer according to the invention can be permanently bonded to HDPE or PP, which corresponds to an adhesive strength (measured by a peel test at 180° (carried out in accordance with FINAT standard No. 1)) preferably in the range of 3 to 15 N / cm.

[0164] The adhesive strength can be measured after the self-adhesive article has been exposed to a particular low surface energy for a particular time period, ranging from a few minutes to a few hours or days, as specifically shown in the examples.

[0165] According to one embodiment, the method for producing a self-adhesive article according to the invention also comprises a step (e) in which a second coating of the adhesive composition according to the invention is applied to the substrate, and a subsequent step (f) in which the adhesive composition applied in step (e) is crosslinked by heating to a temperature in the range of from 20 to 200° C. According to this embodiment, a double-sided self-adhesive article is obtained.

[0166] The coating in step (b) can be carried out using known coaters, such as slot nozzle or curtain coaters or rollers. The basis weight used for the adhesive composition is from 3 to 2000 g / m 2 , preferably 5 to 1000 g / m 2 , more preferably 10 to 500 g / m 2 , and even more preferably from 12 to 250 g / m 2 The range is.

[0167] The weight of the adhesive composition required for the production of self-adhesive labels is between 10 and 100 g / m 2 , preferably 20 to 50 g / m 2 The weight of adhesive composition required to produce a self-adhesive tape can range from 3 to 500 g / m² per side. 2 , preferably 15 to 250 g / m 2 can vary over a much wider range.

[0168] According to one embodiment, the coating of adhesive composition is further subjected in step (c) to a treatment in a humid atmosphere characterized by a water content, preferably an atmosphere in which 2 to 100% of the molecules are water molecules, preferably 4 to 50%, more preferably 5 to 10% of the molecules are water molecules.

[0169] Moisture content is expressed as the percentage of water per unit volume, which corresponds to the number of water molecules divided by the total number of molecules in a unit volume. The linearity of this scale makes moisture content easily measured and controlled, for example, by a PID (proportional-integral-derivative) monitor. The weight percentage can be calculated by multiplying the ratio of the number of water molecules to the total number of molecules by a factor of 0.622. General information about moisture content in various environments can be found in International Steam Tables - Properties of Water and Steam based on Industrial Formulations IAPWS-IF97 by W. Wagner et al.

[0170] The time required for the crosslinking step (c) can vary widely, for example between 1 second and 30 minutes, depending on the weight of the adhesive composition deposited on the carrier surface, the heating temperature and the moisture content.

[0171] This thermal crosslinking step has the effect of creating siloxane bonds between the polymer chains of the mixture of polysilylated A.1) and monosilylated A.2) polymers described above, and under the influence of the water content, which leads to the formation of a three-dimensional polymer network. The adhesive composition thus crosslinked is a pressure-sensitive adhesive that provides adhesive strength and a desired viscosity to the substrate coated with the adhesive.

[0172] Preferably, the coating is uniformly applied onto the backing layer or release liner, but the coating can also be conformed to the final shape desired for the self-adhesive article.

[0173] According to one embodiment, the adhesive composition is coated on at least a portion of both sides of the backing layer. When both sides of the backing layer are coated, the adhesive composition may be the same or different on both sides, and the weight may be the same or different on both sides.

[0174] According to one embodiment of the present invention, the self-adhesive article comprises an adhesive layer on at least a portion of one surface or on at least a portion of both surfaces of a support layer, said adhesive layer or layers being optionally coated with a non-stick protective layer. According to one embodiment, the self-adhesive article comprises two anti-adhesive protective layers, one for each of the two adhesive layers. In this case, both protective layers may be made of the same or different materials and / or may have the same or different thicknesses.

[0175] The self-adhesive article according to the invention can be used in a bonding method comprising the steps of: a) removing a release liner, if present; b) adhering the self-adhesive article onto the surface of the product; and c) applying pressure to said item.

[0176] In step b), the self-adhesive article is applied so that the self-adhesive part of the item (formed by the self-adhesive layer) faces the surface of the product.

[0177] According to one embodiment in which the self-adhesive article is a double-sided item, the bonding method also includes a step in which either the second surface of the product is attached to an item that is bonded to the first surface of the product, or the article that is bonded to the first surface of the product is attached to the second surface of the product.

[0178] Products coated with anti-adhesive items The present invention thirdly relates to a product whose surface is coated with a self-adhesive article according to the present invention.

[0179] Preferably, the surface has not been subjected to the aforementioned surface pre-treatment.

[0180] Preferably, the surface has a surface energy of less than or equal to 40 mN / m, preferably from 23 to 38 mN / m, more preferably from 25 to 35 mN / m.

[0181] Preferably, the surface is smooth and uniform.

[0182] The surface of the product coated with the self-adhesive item according to the invention can be made from a low surface energy substrate such as a polyolefin substrate, which is an organic non-polar substrate or an organic non-polar coating such as a varnish, ink or paint, said substrate having a surface energy of less than 40 mN / m, preferably from 23 to 38 mN / m, more preferably from 25 to 35 mN / m.

[0183] Polyolefin-type substrates can be, for example, polymeric materials based on monomers and comonomers, such as polyethylene (PE), polypropylene (PP), polyisoprene (PI), polyisobutylene (PIB) and their copolymers (block or random), or based on cyclic olefin monomers, such as those obtained by ring-opening metathesis polymerization (ROMP).

[0184] Examples of polyethylene (PE) include, among others, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene, and linear very low density polyethylene.

[0185] Products coated with the self-adhesive article according to the present invention can be flexible or rigid.

[0186] In particular, the product to be coated can have the same flexibility as the support layer described above, so that it can be wound and packaged, for example in the form of a roll, as described above.

[0187] Alternatively, the product to be coated cannot be wound and packaged, for example in roll form as described above, due to its hardness, shape or thickness.

[0188] The following examples are provided purely for the purpose of illustrating the present invention and should not be construed as limiting its scope. [Example]

[0189] The following raw materials were used in the examples:

[0190] As disilylated polymers: PDS 1: a disilylated polymer having a number average molecular weight of about 16,000 g / mol (or 20 kDa and a PI of approximately 1.6 as determined by GPC), comprising a polyurethane backbone and two hydrolyzable propylenetrimethoxysilane end groups, said silylated end groups being linked to the polymer backbone by urethane functional groups, said polymer corresponding in particular to formula (I): - PDS2: a disilylated polymer having a number average molecular weight of about 37,000 g / mol (or 38 kDa as determined by GPC and a PI of approximately 1.9), comprising a polyurethane backbone and two hydrolyzable propylenetrimethoxysilane end groups, said silylated end groups being linked to the polymer backbone by a urethane functional group, said polymer corresponding in particular to formula (I): PDS3: GENIOSIL® STP-E 30 (available from Wacker): a disilylated polymer with a number average molecular weight of about 18,500 g / mol (or 22 kDa as determined by GPC and a PI of approximately 1.2), comprising a polyurethane backbone and two hydrolyzable methylenetrimethoxysilane end groups, said silylated end groups being linked to the polymer backbone by urethane functional groups. This polymer corresponds in particular to formula (I): PDS4: GENIOSIL® STP-E 35 (available from Wacker): a disilylated polymer having a number average molecular weight of about 18,600 g / mol (or 22 kDa and a PI of approximately 1.2 as determined by GPC), comprising a polyurethane backbone and two hydrolyzable propylenetrimethoxysilane end groups, said silylated end groups being linked to the polymer backbone by urethane functional groups. This polymer corresponds in particular to formula (I):

[0191] As monosilylated polymers: - PMS1 GENIOSIL® XM20 (available from Wacker): a monosilylated polymer with a number average molecular weight of 6000 g / mol (or 8 kDa as determined by GPC) and a PI of approximately 1.1. It comprises a polyether backbone and hydrolyzable methylene-methyldimethoxysilane end groups, the silylated end groups being linked to the polymer backbone by urethane functional groups. This polymer corresponds in particular to formula (IIbis) where m=0 and p=1. - PMS2: GENIOSIL® XM25 (available from Wacker): a monosilylated polymer with a number average molecular weight of 6000 g / mol (or 8 kDa as determined by GPC) and a PI of approximately 1.1. It comprises a polyether backbone and hydrolyzable methylene-methyltrimethoxysilane end groups, the silylated end groups being linked to the polymer backbone by urethane functional groups. This polymer corresponds in particular to formula (IIbis) where m=0 and p=0.

[0192] As a tackifying resin: T1: Sylvalite® RE 100 (available from Arizona Chemical), a rosin and pentaerythritol resin with an OHI of about 50 mg KOH / g, a number average molecular weight of about 974 g / mol and a softening point of 100° C. (tackifying resin of type (iii)); T2: DERTOPHENE® H 150 (available from DRT): a terpene-phenolic resin having an OHI of about 150 mg KOG / g, a number average molecular weight of about 700 g / mol and a softening point of 120° C.; T3: NORSOLENE® W85 (available from CRAY VALLEY): an alpha methyl styrene resin having an OHI of 0, a number average molecular weight of about 600 g / mol and a softening point of 85° C. (tackifying resin of type (ii)); T4: NORSOLENE® W110 (available from CRAY VALLEY): an alpha methyl styrene resin having an OHI of 0, a number average molecular weight of about 750 g / mol and a softening point of 110° C. (tackifying resin of type (ii)); - T5: PICCO® AR 100 (available from EASTMAN): resin (tackifying resin of type (i)) obtained by polymerization of a mixture of aromatic hydrocarbons having mainly 9 carbon atoms, an OHI of 0, a number average molecular weight of 550 g / mol and a softening point of 100°C.

[0193] As a crosslinking catalyst: - K-KAT® 5218 (available from King Industries): Contains aluminum chelate.

[0194] I - Preparation of disilylated polymers A.1) Synthesis of PDS1: The following was placed in a glass reactor: - 961.2 g (0.1199 mol) of ACCLAIM® 8200, a poly(oxypropylene) diol; - 12.99 g (0.0582 mol) of isophorone diisocyanate (IPDI); corresponds to a molar ratio of NCO / OH functional groups equal to 0.5; and 0.29 g (corresponding to 300 ppm) of bismuth neodecanoate and zinc catalyst (commercially available from Borchers under the trade name Borchi Kat VP 0244).

[0195] The mixture was constantly mixed at 85° C. under nitrogen for 3 hours until the reaction of the NCO functional groups of IPDI was complete.

[0196] To the hydroxyl-terminated polyurethane thus obtained was then added 26.05 g (0.1269 mol) of gamma-isocyanato-n-propyl-trimethoxysilane and the mixture was maintained at 85° C. until the NCO functionality had completely disappeared.

[0197] The resulting polyurethane had a viscosity of about 55 Pa·s (measured with a Brookfield viscometer at 23°C using a No. 7 needle rotating at 20 rpm) and an average molecular weight of about 16,000 g / mol (or 20 kDa, with a polymolecularity index of about 1.6 determined by GPC).

[0198] Synthesis of PDS2: The following was placed in a glass reactor: - 884.63 g (0.0457 mol) of ACCLAIM® 18200 poly(oxypropylene) diol; - 5.10 g (0.0229 mol) of isophorone diisocyanate (IPDI); corresponds to a molar ratio of NCO / OH functionality equal to 0.5; and - 300 ppm of bismuth neodecanoate and zinc catalyst (commercially available from Borchers under the trade name Borchi Kat VP 0244).

[0199] The mixture was constantly mixed at 85° C. under nitrogen for 3 hours until the reaction of the NCO functional groups of IPDI was complete.

[0200] To the hydroxyl-terminated polyurethane thus obtained, 10 g (0.0474 mol) of gamma-isocyanato-n-propyl-trimethoxysilane was then added and the mixture was maintained at 85° C. until the NCO functionality had completely disappeared.

[0201] The resulting polyurethane had a viscosity of about 510 Pa·s (measured at 23°C with a Brookfield viscometer using a No. 7 needle rotating at 20 rpm) and an average molecular weight of about 37,000 g / mol (or 38 kDa, with a polymolecularity index of about 1.9 determined by GPC).

[0202] II - Preparation of the adhesive composition Adhesive Compositions 1 to 14 and CE1 to CE8 were prepared according to the same procedure described below using the ingredients listed in Table 1 below, where the amount of each ingredient used is given as a weight percent based on the total weight of the adhesive composition.

[0203] Compositions 1 to 14 correspond to adhesive compositions according to the invention.

[0204] Compositions CE1 to CE8 correspond to comparative adhesive compositions, in particular: Compositions CE1 and CE2 correspond to the compositions of Example A of WO 09 / 106699 and EP 2 336 208, respectively, comprising a single disilylated polymer A.1 and a tackifying resin with an OH value of more than 100 mg KOH / g. Compositions CE3 to CE6 correspond to comparative compositions containing a single disilylated polymer A.1). Compositions CE7 to CE8 correspond to comparative compositions containing a single monosilylated polymer A.2).

[0205] Operation steps: The adhesive compositions were prepared by first placing the tackifying resin in a vacuum glass reactor and heating it to about 140° C. Then, when the resin was molten, the silylated polymer A.1) or A.2) or a mixture of silylated polymers A.1) and A.2) was added.

[0206] The mixture was mixed under vacuum for 15 minutes and then cooled to 80° C. The catalyst was then introduced and the mixture was kept under vacuum and mixed for an additional 10 minutes.

[0207] The viscosity of the mixtures was then determined at 100°C using a Brookfield viscometer (equipped with a Thermosel system for high temperature viscosity measurements) with an A28 needle rotating at a speed appropriate for the sensitivity of the sensor. For Examples 1 to 14 according to the invention and the comparative examples, the mixtures had viscosities measured at 100°C ranging from 0.5 Pa·s to 40 Pa·s.

[0208] II - Preparation of Self-Adhesive Articles Each of adhesive compositions 1 to 14 and CS1 to CE8 was used to prepare a self-adhesive article according to the following procedure.

[0209] Operation steps: A 20 cm x 40 cm rectangular sheet of 50 μm thick polyethylene terephthalate (PET) film was used as the support layer.

[0210] The adhesive composition was preheated to a temperature approaching 90°C and placed in a cartridge which extruded a bead that was deposited near the edge of the sheet parallel to its width.

[0211] The adhesive composition contained in this cord was then spread over the entire surface of the sheet to obtain a uniform layer of substantially constant thickness. This was done using a film puller (also called a film applicator) that was moved from one end of the sheet to the other. Thus, a 50 g / m 2 A layer of adhesive composition was deposited, corresponding to a basis weight of approximately 50 μm and representing a thickness of approximately 50 μm.

[0212] The PET sheet thus coated was then placed in a 120°C oven for 600 seconds for crosslinking and then superimposed on another sheet of silicone-surfaced PET film for use as a rectangular non-stick surface of the same size.

[0213] The resulting self-adhesive articles comprising a crosslinked pressure-sensitive adhesive layer on a PET substrate were subjected to the following tests.

[0214] III - Bonding Tests for Self-Adhesive Articles The self-adhesive articles prepared above were subjected to the same conditions after bonding tests on two types of polyolefin substrates: HDPE and PP. The surface energies of the substrates in contact with the tested adhesive were 27 and 29 mN / m for HDPE and PP, respectively. These values ​​were determined using the measurement method described below.

[0215] Determining the surface energy of the substrate: The surface energy of each substrate was determined by measuring the contact angle of a standard solution on the surface of the substrate. The tested substrates were smooth, uniform, 15 cm long and 2.5 cm wide HDPE plates or flat PP. Contact angles were measured for three standard solutions (diiodomethane, ethylene glycol, and water) using a Digidrop device equipped with a syringe set for depositing the standard solutions. The device used to measure the contact angles was connected to Windrop++ software by GBX Scientific Instruments, which calculated the surface energy of the substrate from the measured contact angles. Measurements were performed in open air at 1 bar atmospheric pressure, 23°C, and 50% relative humidity in a room.

[0216] Preparation of the substrate: The substrate was attached to a glass plate 15 cm long and 5 cm wide using double-sided adhesive tape of the same dimensions as the substrate, covering the entire surface of the substrate and lining up at least one corner of the layer consisting of the substrate, adhesive tape, and glass plate. The sample thus formed was smoothed to obtain a smooth, bubble-free surface. The sample was placed under the Digidrop device, with the filling needle pointing toward the surface of the sample substrate and lining up as closely as possible with the edge of the sample.

[0217] Contact angle measurement: The Windrop++ software initiates a droplet program that simultaneously deposits droplets of standard solutions and automatically captures images of the droplets in contact with the substrate surface. After starting the program, images are taken at 13,000 milliseconds (ms) for water and ethylene glycol, and at 2000 ms for diiodomethane. Three drops are deposited for each standard solution. Between each drop, the sample is manually moved so that the droplets are deposited close to each other on the substrate surface, near the sample edge. The droplet sequence is as follows: 3 drops of water, 3 drops of ethylene glycol, and 3 drops of diiodomethane.

[0218] Calculation of contact angle and determination of substrate surface energy: From each image taken, the contact angle is calculated using the "Manual 2" method. Thus, for each standard solution, three contact angle values ​​are obtained. The Owen & Wendt model was applied to calculate the surface energy (EN1) of the substrate and find the contact angle values.

[0219] A second series of contact angle measurements was performed for each standard solution. As before, contact angles were measured for three drops of each standard solution in the above order, after which a second surface energy value (EN2) was obtained.

[0220] A third series of contact angle measurements was performed for each standard solution, after which a second surface energy value (EN3) was obtained.

[0221] The three values ​​EN1, EN2 and EN3 were averaged to obtain the surface energy of the substrate.

[0222] Peel test at 180° on polyolefin (HDPE, PP): FINAT Technical Handbook, 6 th The adhesion to polyolefins is evaluated by a 180° peel test according to the FINAT method No. 1 published in the 2001 edition. FINAT is an international association of manufacturers of self-adhesive labels. The test principle is as follows:

[0223] A test specimen in the form of a rectangular strip (25 mm x 175 mm) is cut from the PET support layer coated with the crosslinked composition constituting the self-adhesive article obtained above. After preparation, the test specimen is stored for 24 hours in an atmosphere at a temperature of 23 ° C and a relative humidity of 50%. Then, at least two-thirds of the length of the test specimen (after removing the part corresponding to the protective release liner) is attached to a substrate consisting of an HDPE or PP plate. The resulting assembly is left at room temperature (23 ° C) for 20 minutes. It is then placed on a pulling device capable of peeling or separating the strip from the remaining free end of the rectangular strip at an angle of 180 ° and a separation speed of 300 mm / min. This device measures the force required to peel the tape under these conditions.

[0224] result: The measurement results, expressed in N / cm, are listed in Table 2 below. It was found that the adhesive compositions of Examples 1 to 14 according to the invention provide self-adhesive articles with superior adhesive strength than the comparative adhesive compositions of Examples CE1 to CE6. Compositions CE7 and CE8 did not make it possible to obtain crosslinked self-adhesive articles in the desired areas, demonstrating the need to combine a disilylated polymer with a monosilylated polymer.

[0225] The superior adhesive performance of the adhesive composition according to the invention to the set of low surface energy substrates tested is the result of a synergistic effect between the different ingredients.

[0226] In particular, the following series of comparisons showed: 1) The use of a mixture of polymers A.1) and A.2) results in improved adhesion performance on all tested low surface energy substrates compared to the use of polymer A.1) alone: - series (1.1): comparison of the comparative composition CE3 with each of the compositions of Examples 3, 4, 6, 9 and 10 according to the invention; - series (1.2): comparison of comparative composition CE5 with the composition of Example 13 according to the invention; Series (1.3): Comparison of the comparative composition CE6 with the composition of Example 14 according to the invention, 2) The use of a mixture of polymers A.1) and A.2) results in improved adhesion performance on all tested low surface energy substrates compared to the use of polymer A.2) alone: - series (2.1): comparison of the comparative composition CE7 with each of the compositions of Examples 4, 10, 12, 13 and 14 according to the invention; - series (2.2): comparison of the comparative composition CE8 with each of the compositions of Examples 3, 6, 9 and 11 according to the invention; 3) The use of a higher content of monosilylated polymer A.2) in the mixture of polymers A.1) and A.2) results in improved adhesion performance to all low surface energy substrates tested: - Series (3.1): Comparison of the compositions of Example 12 and Example 11; - Series (3.2): Comparison of the compositions of Example 3 and Example 9; 4) The use of a higher content of disilylated polymer A.1) in the mixture of polymers A.1) and A.2) leads to improved adhesion performance on all tested low surface energy substrates for the same type of polymer: - Series (4.1): Comparison of the compositions of Example 12 and Example 3; - Series (4.2): Comparison of the compositions of Example 11 and Example 9; 5) The use of a higher content of disilylated polymer A.1) of formula (II) where m is not zero results in improved adhesion performance to all tested low surface energy substrates for silylate with comparable number average molecular weight and end groups compared to disilylated polymer A.1) of formula (II) where m is zero: - Series (5.1): Comparison of the compositions of Example 4 and Example 13; 6) The use of disilylated polymers A.1) containing dialkoxysilane end groups in mixtures with similar dialkoxysilylated monosilylated polymers A.2) results in improved adhesive performance to PP compared to disilylated polymers A.1) containing trialkoxysilane end groups: - Series (6.1): Comparison of the compositions of Example 14 and Example 13; 7) The use of monosilylated polymers A.2) containing dialkoxysilylated end groups in a mixture with similar disilylated polymers A.1) results in improved adhesive performance at least to PP compared to monosilylated polymers A.2) containing trialkoxysilylated end groups: - Series (7.1): Comparison of the compositions of Example 10 and Example 9: the use of A.2) polymers containing dialkoxysilane end groups improves adhesion to HDPE and PP compared to the use of A.2) polymers containing trialkoxysilane end groups; - Series (7.2): Comparison of the compositions of Example 4 and Example 3 according to the invention: the use of A.2) polymers containing dialkoxysilane end groups improves adhesion to PP compared to the use of A.2) polymers containing trialkoxysilane end groups; 8) The use of at least one type (i) resin (T5), and preferably at least one type (i) and type (ii) resin (T5+T4 or T5+T3), results in improved adhesive performance, at least to PP, compared to the use of a mixture of tackifying resins that does not contain the above types; - Series (7.1): Comparison of the compositions of Example 1 and Example 9 according to the invention: the mixtures T5 and T4 improve PP and HDPE relative to the mixtures T1 and T4; - Series (7.2): Comparison of the compositions of Example 2 and Example 4 according to the invention: the mixtures of T5 and T4 improve PP and HDPE relative to the mixtures of T1 and T4; - Series (7.3): Comparison of the compositions of Example 2 and Example 5 according to the invention: the mixtures of T5 and T3 improve PP and HDPE relative to the mixtures of T1 and T3; Table 1: TIFF0007749310000008.tif253170Table 2 TIFF0007749310000009.tif254170

Claims

1. A. 1) at least 4% by weight of one or more polysilylated polymers having a number average molecular weight (Mn) of at least 6000 g / mol selected from polymers comprising a polyether and / or polyurethane backbone and at least two hydrolyzable silylated end groups attached to the polymer backbone by a urethane or ether functional group ("linking group"); A.2) 15 to 69.8 wt. % of one or more monosilylated polymers having an average molecular weight (Mn) of at least 1000 g / mol selected from polymers comprising a polyether and / or polyurethane backbone and hydrolyzable silylated end groups attached to the polymer backbone by a urethane or ether functionality ("linking group"); B) at least 25 wt. % of one or more tackifying resins, each of which comprises a hydroxyl index of 50 or less and a number average molecular weight of 100 to 6000 g / mol; (i) resins obtained by polymerization or copolymerization, optionally by hydrogenation, of a mixture of unsaturated aliphatic and / or aromatic hydrocarbons containing 5, 9 or 10 carbon atoms derived from petroleum fractions; (ii) Resins obtained by a process involving the polymerization of alpha-methylstyrene or copolymerization of alpha-methylstyrene with other hydrocarbon monomers; (iii) naturally occurring rosin or modified rosin, and derivatives thereof that are hydrogenated, dimerized, polymerized, or esterified with monoalcohols or polyols; and (iv) mixtures thereof a tackifying resin selected from among C) at least 0.2% of one or more crosslinking catalysts; An adhesive composition comprising: A composition in which the contents in wt. % are expressed relative to the total weight of the adhesive composition, the sum of the contents of all ingredients of the adhesive composition being 100%.

2. The polysilylated polymer A.1) or at least one of the polysilylated polymers A.1) has the following formula: Formula (I): [In the formula, B represents a divalent (f=2) or trivalent (f=3) linear, branched, cyclic, alicyclic or aromatic, saturated or unsaturated hydrocarbon radical containing from 2 to 66 carbon atoms and optionally containing one or more heteroatoms, -R ３ represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, - R' ２ represents a linear or branched divalent alkylene group containing 2 to 4 carbon atoms, -R ４ and R ５ are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R ４ may optionally be engaged to the ring; n'' is a group of the formula -[OR' ２ ] ｎ’’ is a non-zero integer such that the number average molecular weight of the polyether blocks is in the range of 150 g / mol to 20,000 g / mol, p is an integer equal to 0 or 1, f is an integer equal to 2 or 3. - Formula (II): [In the formula, B represents a divalent (f=2) or trivalent (f=3) linear, branched, cyclic, alicyclic or aromatic, saturated or unsaturated hydrocarbon radical containing from 2 to 66 carbon atoms and optionally containing one or more heteroatoms, -R １ represents a divalent hydrocarbon group containing 5 to 15 carbon atoms, which may be aliphatic or aromatic, linear, branched or cyclic; -R ３ represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, -R ２ and R' ２ are the same or different and each represent a linear or branched divalent alkylene group containing 2 to 4 carbon atoms; -R ４ and R ５ are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R ４ may optionally be engaged to the ring; n is a group of the formula -[OR ２ ] ｎ is a non-zero integer such that the number average molecular weight of the polyether blocks is in the range of 300 g / mol to 40,000 g / mol, n' is a group of the formula -[OR' ２ ] ｎ’ is a zero or non-zero integer such that the number average molecular weight of the polyether blocks ranges from 0 g / mol to 20,000 g / mol, m is a zero or non-zero integer, p is an integer equal to 0 or 1, f is an integer equal to 2 or 3. or a mixture thereof.

3. monosilylated polymer A.2) or at least one of the monosilylated polymers A.2) has the formula - Formula (Ibis): [In the formula, -R ０ represents a divalent hydrocarbon group containing 1 to 60 carbon atoms, which may be aliphatic, aromatic or alkylaromatic, linear, branched or cyclic; -R ３ represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, - R' ２ represents a linear or branched divalent alkylene group containing 2 to 4 carbon atoms, -R ４ and R ５ are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R ４ may optionally be engaged to the ring; - n'" is a group of the formula -[OR' ２ ] ｎ’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether blocks ranges from 0 g / mol to 20,000 g / mol, p is an integer equal to 0, 1 or 2. Formula (IIbis): [In the formula, -R ０ represents a divalent hydrocarbon group containing 1 to 60 carbon atoms, which may be aliphatic, aromatic or alkylaromatic, linear, branched or cyclic; -R １ represents a divalent hydrocarbon group containing 5 to 15 carbon atoms, which may be aliphatic or aromatic, linear, branched or cyclic; -R ３ represents a linear or branched divalent alkylene group containing 1 to 6 carbon atoms, -R ２ and R' ２ are the same or different and each represent a linear or branched divalent alkylene group containing 2 to 4 carbon atoms; -R ４ and R ５ are the same or different and each represents a linear or branched alkyl group containing 1 to 4 carbon atoms; R ４ may optionally be engaged to the ring; n is a group of the formula -[OR' ２ ] ｎ - is an integer such that the number average molecular weight of the polyether block ranges from 300 g / mol to 40,000 g / mol, - n'" is a group of the formula -[OR' ２ ] ｎ’’’ is a zero or non-zero integer such that the number average molecular weight of the polyether blocks ranges from 0 g / mol to 20,000 g / mol, m is a zero or non-zero integer, p is an integer equal to 0, 1 or 2.

3. The composition according to claim 1 or 2, which corresponds to a mixture thereof.

4. 4. The composition of claim 2 or 3, wherein the polysilylated polymer A.1) corresponds to formula (II) wherein m is not zero.

5. 5. The composition according to claim 3 or 4, wherein the monosilylated polymer A.2) corresponds to formula (IIbis), wherein m is zero.

6. 6. The composition of claim 2, wherein p=0.

7. 6. The composition of claim 2, wherein p=1.

8. 8. The composition of any one of claims 1 to 7, wherein the polysilylated polymer A.1) is disilylated.

9. the polysilylated polymer A.1) has a number average molecular weight (Mn) of 6000 to 55,000 g / mol, the monosilylated polymer A.2) has a number average molecular weight (Mn) of 1000 to 55,000 g / mol, 9. The composition of any one of claims 1 to 8.

10. the content of polysilylated polymer A.1) is from 5 to 59.8% by weight, relative to the weight of the adhesive composition; the content of monosilylated polymer A.2) is from 15 to 69.8% by weight, relative to the weight of the adhesive composition; the content of tackifying resin B) is from 25 to 79.8% by weight, based on the weight of the adhesive composition, and the content of crosslinking catalyst C) ranges from 0.2 to 4% by weight of the adhesive composition; A composition according to any one of claims 1 to 3.

11. A self-adhesive article comprising a support layer coated with a self-adhesive layer, wherein the self-adhesive layer is made of an adhesive composition according to any one of claims 1 to 10 in a crosslinked state.

12. 12. The self-adhesive article according to claim 11, characterized in that the support layer has an elongation at break strictly less than 100% and is based on an acrylic polymer, polyethylene (PE), polypropylene (PP), oriented, non-oriented or biaxially oriented polyimide, polyurethane, polyester or paper.

13. 13. A product having adhered to its surface the self-adhesive article of claim 11 or 12, wherein the surface has a surface energy of 40 mN / m or less, measured in air at 23°C, 50% relative humidity and 1 bar atmospheric pressure.

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