Polymers that provide adhesion

Abstract

A material having the following structure (A): TIFF2025508456000012.tif46111(A) (Wherein, R and R 1 may be the same or different and each independently represents an alkyl or aryl group; X is hydrogen or a C1-C 20 wherein the aromatic ring substituent attached to polymer B is at the meta or para position of the aromatic ring substituent attached to polymer A, polymer A is a non-polar polymer, and polymer B is a polymer formed from at least two polar monomers, and the material is used to improve adhesion of coatings such as paints, inks, and adhesives to polyolefin substrates.

Description

[Technical field]

[0001] The present invention relates to novel polymers having improved adhesion properties, particularly to olefin polymer and copolymer substrates, such as polyethylene and polypropylene, and copolymers of ethylene and propylene, optionally with other olefinic monomers. The polymers of the present invention are particularly useful for improving the adhesion of coatings, such as paints, inks, adhesives, sealants, varnishes, and primers, to olefin polymers and copolymers. [Background technology]

[0002] Polyolefin-based resins, such as polypropylene and polyethylene, are inexpensive and have various good properties, such as good moldability, chemical resistance, water resistance, and electrical properties. Such polyolefin-based resins are widely used for substrates such as sheets, films, and molded products. However, polyolefin-based resins are non-polar (hereinafter, these base materials containing polyolefin-based resins may be referred to as "polyolefin-based materials") and have the disadvantage of low adhesion to polar materials used in coatings such as paints, inks, and adhesives. It has been proposed to solve this problem by modifying the surface of the polyolefin substrate by activation with plasma or gas flame treatment or corona treatment to improve the adhesion properties of the surface. However, these methods are complex, require high equipment costs and involve time losses. A further drawback is that the effect of the surface treatment can be non-uniform, especially when the base material has a complex shape and / or due to the influence of pigments or other additives in the polyolefin substrate, which only becomes apparent after applying a coating such as ink, paint or adhesive, meaning that the part cannot be reprocessed and the waste produced must be discarded. Another method to improve the adhesion of olefin polymer or copolymer to polar coating is to use chlorinated polyolefin resin as primer coating composition to improve the compatibility between polyolefin-based material and polar paint or other polar material, and thus improve adhesion properties. However, this method has stability problems due to desalination oxidation. In addition, due to the increasing environmental awareness in recent years, there is a tendency to avoid the use of chlorine.

[0003] EP 2380917 relates to improving the adhesion of coatings to polyolefin substrates and provides an energy beam curable resin composition comprising a block copolymer (C) containing a polymer block (A) mainly composed of olefin-based monomer units and a polymer block (B) composed of units derived from (meth)acrylic acid and / or units derived from methacrylic esters, the block copolymer (C) having a weight average molecular weight of 5,000 or more and 100,000 or less, and the active energy beam curable compound (D) is selected from the group consisting of mono(meth)acrylates and poly(meth)acrylates. This technology is also described in a paper entitled "Study on Propylene-Acrylic Block Copolymers as additives in UV Curable Coatings" by Hideo Hosaka, Yu Takatu, Shuaiji Sekiguchi and Kon-ich-Fujiio.

[0004] This technique has the disadvantage that both the block copolymer and a separate active energy radiation curable resin compound must be employed to obtain the desired adhesion of the coating to the olefin polymer or copolymer, and furthermore, the material after application to the polyolefin substrate must be irradiated to activate the adhesive properties of the system.Furthermore, the molecular weight of the polymer is controlled by pyrolysis, which is not the best method for controlling molecular weight. Summary of the Invention

[0005] The present inventors have discovered that by using certain diblock copolymers that can be applied to the surface of an olefin polymer or copolymer substrate as an intermediate primer layer or incorporated as an additive into a coating material, satisfactory adhesion between the coating and the olefin polymer or copolymer substrate can be achieved, which provides good adhesion while requiring less surface preparation than previous techniques, and in many cases the substrate is ready for application of the coating material simply by coating and drying. European Patent No. 2684940 and European Patent No. 3144330 disclose the following formula:

[0006] [ka] Certain block copolymers of have been described as fuel and oil additives, as have methods for making such block copolymers, and in EP 3253810 the use of such polymers as polymer additives is described. The present inventors have discovered a particular block copolymer having the following structure:

[0007] [ka] (Wherein, R and R 1 may be the same or different and each independently represents an alkyl or aryl group; X is hydrogen or a C1-C 20 Polymer B may be an alkyl group, and the aromatic ring substituent attached to polymer B is at the meta or para position to the aromatic ring substituent attached to polymer A, polymer A is a non-polar polymer (or copolymer), and polymer B is a polar copolymer formed from two or more polar monomers that are useful for promoting adhesion between olefin polymer substrates and polar coating materials such as inks and paints. The selection of polymer A and polymer B depends on the nature of the olefin polymer and the coating to which they are to be bonded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In a preferred embodiment, i) polymer A comprises a chain of ethylene or propylene structural units, optionally copolymerized with a higher 1-alkene comonomer, the preferred chains being polyethylene or polypropylene or propylene / ethylene copolymer chains; ii) Polymer B is derived from two or more α,β-unsaturated polar monomers selected from styrene, substituted styrenes, unsaturated esters such as acrylates, methacrylate esters such as butyl acrylate, methyl (meth)acrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, poly(ethylene glycol) methacrylate, butyl methacrylate, and hydroxyethyl acrylate and vinyl esters, fumaric acid esters, itaconic acid esters, maleic anhydride, unsaturated acids such as acrylic and methacrylic acid ionomers, and diene compounds and derivatives thereof; Polymer B may also comprise copolymers of such unsaturated monomers with alkenes such as C2-C8, preferably C2-C6 alkenes.

[0009] These polymers are a) in a first step, polymerizing an alkene, for example ethylene or propylene, and optionally one or more higher 1-alkene comonomers, to form a polymer A, which is a chain of ethylene or propylene structural units, optionally bearing pendant alkyl groups derived from the 1-alkene comonomers, the polymerization reaction being carried out in the presence of a compound of formula (I),

[0010] [ka] (I) wherein during the course of the reaction, compound (I) is incorporated at the end of polymer A, thereby forming a terminally unsaturated intermediate of formula (II); [ka] (II) b) in an optional second step, recovering intermediate (II) from the reaction mixture of the first step; c) in a third step, reacting intermediate (II) at the terminal double bond with a mixture of two or more polar monomers (which may be copolymerized with non-polar monomers) in a subsequent polymerization reaction to form a polymer B bound to intermediate (II), R, R1, and X are as previously defined. It may also be prepared by Optionally, step a) may be carried out under hydrogen pressure to control the properties of polymer A. Step a) employs a catalyst for the polymerization of the monomers and the reaction of the polymer with the compound of formula (I). Any suitable olefin polymerization catalyst may be used, such as a conventional Ziegler catalyst, or the catalysts mentioned in the document entitled Post Metallocenes in the Industrial Production of Polyolefins, Angie-Chem. Int. Ed 2014 2-25, although metallocene catalysts are preferred.

[0011] As used herein, the term "terminal", when used in relation to a polymer chain (or block), refers simply to the end of the polymer chain (or block) and does not imply any additional mechanistic requirement that the end of the chain (or block) in question be the end at which the polymerization reaction has terminated. References to "at the end, terminally" should be interpreted similarly. It is important that polymer A is terminally bonded to polymer B, as this leaves polymer A exposed for interaction with the polymer substrate with which it is used, improving the adhesion of the coating to the substrate. It is therefore important that the bond between polymer A and polymer B is located at the end of the polymer chain of polymer A.

[0012] To place the bond between polymer A and polymer B in this terminal position, it is essential that the method by which the copolymer is prepared is dedicated to the terminal functionalization of polymer A. Similarly, it is important that the terminal functionalization made on polymer A is sufficiently reactive to allow the subsequent formation of polymer B under typically industrially practical radical polymerization conditions, while at the same time not being so reactive that undesirable side reactions occur to any significant extent.

[0013] The present invention and preferred materials for use in the present invention are those in which polymer A comprises chains of ethylene or propylene structure or ethylene / propylene copolymer chains, possibly interrupted by one or more structural units derived from higher 1-alkene comonomers such as hexene or octene, and polymer B comprises chains of structural units derived from two or more α,β-unsaturated polar monomers selected from styrene, substituted styrenes, unsaturated esters such as acrylates, methacrylate esters, vinyl esters, fumaric acid esters, itaconic acid esters, maleic anhydride, unsaturated acids such as acrylic acid and methacrylic acid, and diene compounds and derivatives thereof, and polymer B may be a copolymer of such monomers with alkenes such as C2-C8 alkenes. In a preferred embodiment, polymer B is a copolymer of at least three monomers, at least some of which provide pendant polar groups on polymer B for interaction with polar groups in the coating material to which polymer B is bonded to the polyolefin substrate. The material used in the present invention is a) in a first step, polymerizing an alkene, typically ethylene or propylene, and optionally one or more higher 1-alkene comonomers, to form a polymer A, the reaction being carried out in the presence of a compound of formula (I),

[0014] [ka] (I) wherein during the course of the reaction, compound (I) is incorporated at the end of polymer A, thereby forming a terminally unsaturated intermediate of formula (II); [ka] (II) b) optionally, in a second step, recovering intermediate (II) from the reaction mixture of the first step; c) in a third step, reacting intermediate (II) with two or more polar monomers at the terminal double bonds in a subsequent polymerization reaction to form a polymer B; R, R 1 and X are as previously defined. It may be prepared by a method comprising:

[0015] The method embodiment of step c) is preferably carried out in the presence of a radical source, which initiates the polymerization of two or more α,β-unsaturated monomers with each other and with intermediate (II). Examples of such monomers include styrene, substituted styrenes, unsaturated esters, including esters containing polar groups such as hydroxyl groups, such as acrylates and methacrylate esters, vinyl esters, fumarate esters, itaconic esters, unsaturated acids, such as acrylic and methacrylic acid, unsaturated anhydrides, such as maleic anhydride and diene compounds and their derivatives. As is known in the art, such a radical source may be a chemical initiator species or may be an external physical input to the reaction, such as light or other radiation source. Preferably, the radical source is a chemical initiator species, such as a peroxide initiator, an azo initiator, or other such species. Preferred monomers for the preparation of polymer B include butyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, glycidyl methacrylate, poly(ethylene glycol) methacrylate, poly(propylene glycol) methacrylate, hydroxyethyl acrylate, acrylic and methacrylic acid, maleic anhydride, and various ionomers. Preferred materials include block copolymers in which polymer A is derived from propylene or ethylene, optionally containing other alkenes, and polymer B is a terpolymer of butyl acrylate, acrylic acid, and hydroxyethyl methacrylate.

[0016] Thus, in a preferred embodiment, the material used in the present invention comprises two polymer segments A and B: i) polymer A comprises a chain of ethylene and / or propylene structural units, optionally interrupted by one or more structural units derived from higher 1-alkene comonomers; ii) polymer B comprises a chain of structural units derived from two or more α,β-unsaturated monomers selected from styrene, substituted styrenes, unsaturated esters such as acrylates, methacrylates and vinyl esters, fumarates, itaconic esters, unsaturated acids such as acrylic acid and methacrylic acid, maleic anhydride and diene compounds and derivatives thereof, polymer B may also comprise a copolymer of such an unsaturated monomer with an alkene, such as a C2-C8 alkene, preferably a C2-C6 alkene; Polymer A and polymer B are end-linked such that the copolymer has the following structure:

[0017] [ka] (In the formula, R, R 1 and X are as defined above, and the aromatic ring substituent attached to polymer B is in the meta or para position to the aromatic ring substituent attached to polymer A. Preferably, each R and R 1 The groups independently represent an alkyl group having 1 to 4 carbon atoms. More preferably, R and R 1 are the same, and most preferably, both are methyl. Preferably, the aromatic ring substituent attached to polymer B is meta to the aromatic ring substituent attached to polymer A. Polymer A is selected to be compatible with the olefin polymer or copolymer that provides the substrate to which the coating will adhere. When the polymer of the present invention is used with a substrate that is primarily based on polypropylene, polymer A is preferably composed primarily of propylene, although other comonomers may also be present. Similarly, when the polymer is used with a substrate that is primarily based on polyethylene, polymer A is preferably composed primarily of polyethylene, although other comonomers may also be present. This has generally been found by the inventors to improve adhesion between the top coating and the substrate.

[0018] In another preferred embodiment, polymer A in the material used in the present invention consists of polypropylene chains. In another preferred embodiment, polymer A in the material used according to the invention consists of an ethylene-propylene copolymer. In another preferred embodiment, polymer A in the material used according to the invention consists of an ethylene 1-hexene copolymer. In another preferred embodiment, polymer A in the material used according to the invention consists of an ethylene 1-octene copolymer. If desired, polymer A may be rendered polar after formation by grafting it with an unsaturated monomer such as maleic anhydride.

[0019] When one or more higher 1-alkene monomers are used in combination with ethylene or propylene to form polymer A, preferably the total proportion of higher 1-alkene monomers is between 1 and 50 mol %, preferably between 2 and 40 mol %, with the remainder of polymer A being derived from ethylene or propylene. If used, the amount of 1-alkene monomer in polymer A is preferably in the range of 2 to 15 mol %. A preferred 1-alkene monomer is octene.

[0020] Polymer A is preferably produced using a metallocene catalyst, and suitable metallocene catalysts for producing polymer A include transition metals, particularly metals belonging to Group IV of the periodic table, such as Ti, Zr, or Hf, with one or more ligands such as cyclopentadienyl ("Cp"), substituted cyclopentadienyl (including indenyl, fluorenyl and derivatives thereof), and bridging variants of the above. Further ligands may be coordinated or bonded to the metal by heteroatoms such as N, O, S, or P, and may include bridging to the Cp-type ligands described above.

[0021] Such catalysts are typically synthesized and stored as metal dichloride / dialkyl (e.g., dibenzyl), or mono-alkyl-mono-chloride species ("pre-catalysts"), which are activated in solution by the addition of a co-catalyst, typically methylaluminoxane (MAO) or polymethylaluminoxane (PMAO), although alternatively non- / weakly coordinating anions may be used, such as combinations of boron-containing species such as Ph3C+B(C6F5)4- and trialkylaluminum species such as i-(C4H9)3Al.

[0022] Examples of such catalysts include Cp2MCl2, Cp*2MCl2, EBIMCl2, Flu(Ph2Me)CpMCl2, and Cp(Me)4(Me2Si)NtBuMCl2, where M represents a transition metal. Preferred catalysts are those where M represents zirconium. An example of a catalyst includes Cp2ZrCl2 with a cocatalyst. Polymer B of the present invention is a copolymer of at least two polar monomers, at least one of which ensures the dispersion or solubility of the block copolymer of the present invention in the medium in which it is used, which may be a solvent or liquid carrier if the block copolymer is used as a primer coating, or a solvent or carrier of the coating material if the polymer of the present invention is included in a coating material. Polymer B also contains at least one other polar monomer to provide adhesion between the olefin polymer or copolymer substrate and the coating material applied to the substrate, which coating material, if a paint, ink or adhesive, tends to contain a polar material.

[0023] Polymer B is preferably derived from acrylate monomers because of their good reactivity with diisopropylbenzene, a preferred material for use in making block copolymers. In particular, the use of acrylic acid together with butyl acrylate has been found to be particularly useful because butyl acrylate provides solubility in solvents such as xylene, and acrylic acid provides the necessary polarity to react with functional groups in coating materials such as inks and paints. The preferred configurations of polymer A and polymer B depend on the substrate with which they are used and the nature of the top coating to be bonded to the substrate. However, when polymer A is predominantly propylene-based, the number average molecular weight is preferably in the range of 3000 to 5000. When polymer A is predominantly ethylene-based, the number average molecular weight is preferably in the range of 1000 to 10,000, preferably in the range of 1000 to 2000. The preferred range of number average molecular weight for polymer B is 500 to 5000. All molecular weights are measured by NMR.

[0024] The polymer of the present invention may be used as an intermediate primer coating on a substrate to adhere a topcoat to the substrate. Alternatively, the polymer may be incorporated into the topcoat. As an additional or less preferred alternative, the polymer of the present invention may be included in the substrate. When the polymer is applied to a polyolefin substrate as a primer coating, it is preferably applied as a solution or suspension of the polymer, which is then dried before applying a topcoat. The liquid used to make the solution or suspension depends on the conditions employed, but when the polymer is applied as a suspension, organic solvents such as xylene and butyl alcohol can be used as well as water, and surfactants may be included as necessary. Also, mixtures of solvents may be used, such as a mixture of an organic solvent such as butyl acrylate and water. Similarly, if the polymer is included in a top coating and the top coating is applied as a liquid, the polymer should be soluble or dispersible in the liquid medium used in the top coating, If the top coating is applied as a melt, the polymer of the present invention should be miscible or soluble in the molten top coating when applied.

[0025] Examples of topcoats for which the present invention is useful include paints, such as automotive paints, which can be water-based or solvent-based.Typical paints include 2K paints, such as 2K polyurethane paints, acrylic paints, and spray paints.Other coatings are inks, such as typical commercial inks, including solvent-based inks.The present invention may also be used to bond other coatings, such as adhesives, including most typical commercial adhesives, and varnishes, to polyolefin substrates.

[0026] The polymers of the present invention have been found to be useful in promoting the adhesion of coatings to a variety of substrates. For example, the substrates may include molded and extruded articles, including films and heavy duty sheeting, various types of parts, such as automobiles and consumer electronics. The substrates may be filled with reinforcing fibers, such as glass or carbon fibers. The substrates may contain other conventional additives. EXAMPLES

[0027] Example 1 below illustrates the preparation of a material that may be used in the present invention, where Polymer A is polypropylene. Preparation of polypropylene and 1,3-diisopropylbenzene intermediates The catalyst used was a mixture of a 30% by weight solution of polymethylaluminoxane in toluene and racemic ethylenebis(1-indenyl)zirconium dichloride. 0.013 kg of polymethylaluminoxane solution, 0.014 g of zirconium dichloride, 0.216 grams of hydrogen, 0.316 liters of metadiisopropylidenebenzene, 1.391 kilograms of propylene, and 0.685 liters of toluene were introduced into a stirred pressure reactor. The vessel was pressurized with nitrogen and heated to 60°C. Toluene, diisopropylidenebenzene, and catalyst were initially charged to the reactor and stirred at 850 rpm. Propylene was then fed into the reactor along with hydrogen. The temperature of the reaction was monitored and upon reaching an exothermic peak, the temperature was maintained between 70-75°C until consumption of the catalyst was complete.

[0028] The reactor was then vented, the contents evacuated, cooled, and 7 liters of methanol were added to dissolve the polymer. Finally, the sample was filtered, washed with methanol, and dried in vacuum at 85° C. for 3 days. Analysis showed that the polymer had an Mn of 4400 g / mol and an Mw of 9400 g / mol. Confirmation of the desired end-functionalized structure is obtained by nuclear magnetic resonance spectroscopy. For example, NMR spectra can be recorded on Bruker DPX400 and DPX500 spectrometers, where 1 H and 13 C NMR spectra are internally referenced using the solvent resonance to tetramethylsilane. Conventional NMR assignments (including polymer samples) are provided as necessary. 1 H- 1 H(COSY), 13 C- 1 H(HMQC), and 13 C- 1 This can be confirmed by correlation experiments with H(HMBC). In particular, to confirm that compound (I) has been inserted at the end, 1H NMR spectroscopy can be employed. Measurement of the amount of terminal insertion is accomplished by comparing the spectroscopic peak of a single proton on the benzylic carbon of the 1,3-DIB molecule remaining after step a) of the reaction with the methyl group at one end of the polyethylene chain, which has three protons. The 1,3-DIB incorporated within the chain does not have a proton on this carbon, and therefore this proton resonance can be used to identify that the 1,3-DIB has been terminally inserted.

[0029] These protons are associated 1 The chemical shifts of the H NMR peaks are 0.91 ppm and 2.71 ppm, respectively (the chemical shifts are measured relative to the residual solvent signal of d2-TCE at 5.94 ppm). Comparing the integrals of these two peaks gives the amount of end insertion by 1,3-DIB, indicating that essentially each polypropylene chain is end-functionalized with a residue of 1,3-DIB.

[0030] The third step (c) of the process involves the formation by radical polymerization of polymer B. The following examples show how this can be done. The polypropylene diisopropylbenzene material thus produced was then used as the starting material for the preparation of the polypropylene-di-isopropylbenzene-block (butyl acrylate / acrylic acid / hydroxyethyl methacrylate) copolymer of the present invention as follows. 2.42 grams of benzoyl peroxide initiator was dissolved in 20 ml of xylene in a vessel, which was then purged with nitrogen. 15 grams of polypropylene diisopropylbenzene and 150 ml of xylene were charged in another vessel, and 12.31 ml of acrylic acid and hydroxyethyl methacrylate were charged in a third vessel equipped with an air purge. The polypropylene diisopropylbenzene was charged in a reactor and heated to 125°C with mechanical stirring while purging with nitrogen. The acrylic monomer mixture and initiator were then fed into the reactor while the reactor was held at 125-130°C for about 1 hour, resulting in a reaction product in the form of a polymer dispersion in xylene.

[0031] The Mw of the final polymer was found to be approximately 1200 g / mol, but initial analysis of the polar block indicates that the ratio of monomer units is 13 butyl acrylate:5 acrylic acid:5 hydroxyethyl methacrylate, giving a molecular weight (Mw) of 2,700 g / mol. In the first run, the homopolymer formed along with the unreacted monomer was removed, in the second run the homopolymer and unreacted monomer remained in the product. Example 2 A product comprising polyethylene / diisopropylbenzene / poly(butyl acrylate / acrylic acid / hydroxyethyl methacrylate copolymer) was prepared in a manner similar to that of Example 1, except that ethylene was used as the feed instead of propylene in the first stage of preparation to produce a polyethylene / diisopropylbenzene polymer with a Mn of 1300 g / mol and a Mw of 4,200 g / mol.

[0032] Initial analysis of the polar block of the product indicated a ratio of 3:2:2 butyl acrylate:hydroxyethyl methacrylate monomer units and a Mw of 800 g / mol, whereas the Mw of the final product was approximately 5000 g / mol. In both examples, molecular weights were determined by high temperature GPC in TCB at 160°C. An important application of the polymers of the present invention is to impart the necessary surface activity to provide a printable or paintable surface to polyolefin substrates such as packaging films, bags, garbage disposal bags, automotive parts such as bumpers, etc., where materials can be used in which polymer A is a polyalkene such as polyethylene or polypropylene, and polymer B is a polar monomer that reacts with a polar compound in a coating material such as a paint or ink to impart the desired adhesion, examples of which include vinyl acetate, acrylates such as methyl acrylate and butyl acrylate, or itaconic acid esters. Examples of preferred monomers for making polymer B are acrylates, substituted acrylates, and unsaturated carboxylic acids.

[0033] Example 3 Example 1 was repeated, except that 0.85 mole % octene-1 was included in the propylene to produce a polymer where Polymer A was a propylene / octene-1 copolymer. The products of Examples 1, 2, and 3 were tested as coatings on polypropylene and polyethylene to determine their adhesion properties and were found to have good adhesion to polyethylene and polypropylene plates as well as biaxially oriented polypropylene film. Adhesion was found to be good.

[0034] A dispersion in xylene of the material of Example 1 was tested as a primer coating on polypropylene and propylene copolymer substrates to determine its ability to bond inks, automotive paints, and adhesives, including epoxy and urethane based adhesives, and 2KPU varnish to the substrates. Adhesion was found to be good. The dispersion in xylene of Example 2 was tested as a primer coating on polyethylene and ethylene copolymer substrates to measure its ability to bond ink, automotive paint, and 2KPU varnish to the substrate and was found to have good adhesion.

[0035] Adhesion was tested according to ASTM-D3359 Test Method B (Cross Cut Tape Test) using Tesa's 25 mm 4651 tape and BYK's Cross Cut Knife II blade 1-edge 1.5 mm (5127).

[0036] The products of both runs of Example 1 were also used as additives in inks and automotive paints at various concentrations, and the adhesion of the inks and paints to propylene copolymer substrates was measured, with good adhesion being obtained in these blends.

Claims

1. A block copolymer having the following structure: 【Chemistry 1】 (Wherein, R and R 1 may be the same or different and each independently represents an alkyl group or an aryl group; X is hydrogen or a C 1 -C 20 an alkyl group, the aromatic ring substituent attached to polymer B is at the meta or para position of the aromatic ring substituent attached to polymer A, polymer A is a non-polar polymer (or copolymer), and polymer B is a polar copolymer formed from two or more polar monomers.

2. i) polymer A comprises a chain of ethylene or propylene structural units, optionally copolymerized with a higher 1-alkene comonomer; ii) The block copolymer of claim 1, wherein polymer B is derived from two or more α,β-unsaturated polar monomers selected from styrene, substituted styrenes, unsaturated esters such as acrylates, methacrylate esters, and vinyl esters, fumaric acid esters, itaconic acid esters, maleic anhydride, unsaturated acids such as acrylic acid and methacrylic acid, ionomers, and diene compounds and derivatives thereof.

3. 3. The block copolymer of claim 2, wherein polymer B comprises a copolymer of an unsaturated monomer and a C2-C8 alkene.

4. 4. The block copolymer of claim 1, wherein polymer B is a copolymer of at least three monomers, at least some of which provide pendant polar groups to polymer B.

5. The block copolymer according to any one of claims 1 to 4, wherein polymer B is a terpolymer.

6. 6. The block copolymer of claim 1, wherein one of the monomers in polymer B is butyl acrylate.

7. 7. The block copolymer of claim 6, wherein polymer B is a terpolymer of butyl acrylate, acrylic acid and hydroxyethyl methacrylate.

8. 8. The block copolymer according to claim 1, wherein polymer A is a polypropylene or propylene-containing polymer and has a number average molecular weight in the range of 3,000 to 5,000.

9. 9. The block copolymer of claim 1, wherein polymer A is a polyethylene or ethylene-containing polymer having a number average molecular weight in the range of 1000 to 10,000.

10. The block copolymer according to any one of claims 1 to 9, wherein the number average molecular weight of polymer B is in the range of 500 to 5,000.

11. A solution of the block copolymer according to any one of claims 1 to 10.

12. A dispersion of the block copolymer according to any one of claims 1 to 10.

13. The dispersion of claim 12 comprising an aqueous dispersion.

14. Use of a block copolymer according to any one of claims 1 to 10 as an adhesive for fixing polar coating materials to polyolefin substrates.

15. 15. The use according to claim 14, wherein the block copolymer constitutes a primer coating of a polyolefin substrate and the polar coating material is a top coating.

16. 15. The use according to claim 14, wherein the block copolymer is a component in a polar coating material.

17. Use according to any one of claims 14 to 16, wherein the polyolefin substrate is a polypropylene or a propylene copolymer and polymer A is a polypropylene or a propylene copolymer.

18. Use according to any one of claims 14 to 16, wherein the polyolefin substrate is a polyethylene or an ethylene copolymer and polymer A is a polyethylene or an ethylene copolymer.

19. The use according to any one of claims 14 to 18, wherein the polar coating material is a paint.

20. The use according to any one of claims 14 to 18, wherein the polar coating material is an ink.

21. The use according to any one of claims 14 to 18, wherein the polar coating is an adhesive.

22. An ink comprising the block copolymer according to any one of claims 1 to 10.

23. A paint comprising the block copolymer according to any one of claims 1 to 10.

24. An adhesive comprising the block copolymer according to any one of claims 1 to 10.

25. A method for preparing the block copolymer according to any one of claims 1 to 10, comprising the steps of: a) in a first step, polymerizing an alkene, typically ethylene or propylene, and optionally one or more higher 1-alkene comonomers, to form a polymer A, the reaction being carried out in the presence of a compound of formula (I): 【Chemistry 2】 (I) wherein, during the course of the reaction, compound (I) is incorporated at the end of polymer A, resulting in the formation of a terminally unsaturated intermediate of formula (II); 【Chemistry 3】 (II) b) optionally, in a second step, recovering intermediate (II) from the reaction mixture of the first step; c) in a third step, reacting intermediate (II) at the terminal double bonds with two or more polar monomers in a subsequent polymerization reaction to form polymer B; R, R 1 and X is as previously defined. A method comprising:

26. 26. The method of claim 25, wherein step c) is carried out in the presence of a radical source, which initiates the polymerization of the two or more α,β-unsaturated monomers with each other and with intermediate (II).

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