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EP-3652263-B1 - EPOXY ADHESIVE COMPOSITION COMPRISING A MULTISTAGE POLYMER AND A (METH) ACRYLIC POLYMER, ITS METHOD OF PREPARATION AND ITS USE

EP3652263B1EP 3652263 B1EP3652263 B1EP 3652263B1EP-3652263-B1

Inventors

  • HAJJI, PHILIPPE
  • PIRRI, ROSANGELA
  • INOUBLI, RABI

Dates

Publication Date
20260513
Application Date
20180712

Claims (15)

  1. A polymer composition suitable as epoxy adhesive composition comprising a) a first part composition (P1) comprising a1) an epoxy resin, a2) a multistage polymer (MP1) having a core-shell structure, a3) a polymer (C1) that is a (meth) acrylic polymer, and b) a second part composition (P2) comprising b1) a curing agent, characterized in that the polymer (C1) is having a mass average molecular weight Mw between 100 000g/mol and 1 000 000g/mol, measured by size exclusion chromatography (SEC) and characterized in that the ratio r of the polymer (C1) in a composition comprising only the multistage polymer (MP1) and the polymer (C1) is less than 25wt%.
  2. The composition according to claim 1, characterized in that the ratio r of the polymer (C1) in a composition comprising only the multistage polymer (MP1) and the polymer (C1) is less than 24wt% and even more advantageously less than 20wt%.
  3. The composition according to any of claim 1, characterized in that the ratio r of the polymer (C1) in a composition comprising only the multistage polymer (MP1) and the polymer (C1) is at least 5wt%, more preferably at least 7wt% and still more preferably at least 10wt%
  4. The composition according to any of claim 1, characterized in that the ratio r of the polymer (C1) in a composition comprising only the multistage polymer (MP1) and the polymer (C1) is between 7wt% and less than 25wt%, more advantageously between 10wt% and less than 24wt% and even more advantageously between 10wt% and less than 20wt%.
  5. The polymer composition according to any of claims 1 to 4, characterized that the polymer (C1) comprises at least 70wt% monomers chosen from C1 to C12 alkyl (meth)acrylates.
  6. The polymer composition according to any of claims 1 to 5, characterized in that the polymer (C1) comprises a functional comonomer.
  7. The polymer composition according to claim 6, characterized in that the functional monomer is chosen from glycidyl (meth)acrylate, acrylic or methacrylic acid, the amides derived from these acids, such as, for example, dimethylacrylamide, 2-methoxyethyl acrylate or methacrylate, 2-aminoethyl acrylates or methacrylates are optionally quaternized, polyethylene glycol (meth) acrylates.
  8. The polymer composition according to claim 5, characterized in that the polymer (C1) comprises at least 80wt% of monomers C1 to C4 alkyl methacrylate and/or C1 to C8 alkyl acrylate monomers and preferably the at least 80wt% the acrylic or methacrylic momonomers of the polymer (C1) are chosen from methyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and mixtures there of.
  9. A method for manufacturing a polymer composition suitable as epoxy adhesive composition comprising the steps of (a) providing a first part composition (P1) comprising a1) an epoxy resin, a2) a multistage polymer (MP1) having a core-shell structure, a3) a polymer (C1) that is a (meth) acrylic polymer; (b) providing a second part composition (P2) comprising b1) a curing agent (c) curing the mixture of (P1) and (P2) characterized in that the polymer (C1) is having a mass average molecular weight Mw between 100 000g/mol and 1 000 000g/mol, measured with size exclusion chromatography (SEC).
  10. The method according to claim 9, characterized in that the multistage polymer (MP1) having a core-shell structure and a3) the polymer (C1) of the first part composition (P1) form together a polymer composition (PC1) are made by a method for manufacturing comprising the steps of a) polymerizing by emulsion polymerization of a monomer or monomer mixture (A m ) to obtain one layer in stage (A) comprising polymer (A1) having a glass transition temperature of less than 10°C, determined according to the method disclosed in the specification, b) polymerizing by emulsion polymerization of a monomer or monomer mixture (B m ) to obtain layer in stage (B) comprising a polymer (B1) having a glass transition temperature of at least 60°C, determined according to the method disclosed in the specification, c) polymerizing by emulsion polymerization of a monomer or monomer mixture (Cm) to obtain a layer in stage (C) comprising a polymer (C1) having a glass transition temperature of at least 30°C, determined according to the method disclosed in the specification, characterized that the polymer (C1) has a mass average molecular weight Mw of at least 100 000g/mol, measured with size exclusion chromatography (SEC), and that the component c) represents less than 25wt%.
  11. The method according to any of claims 9 to 10, characterized in that the multistage polymer (MP1) having a core-shell structure and a3) the polymer (C1) of the first part composition (P1) form together a polymer composition (PC1) are made by a method for manufacturing comprising the steps of a) mixing of the polymer (C1) and the multi stage polymer (MP1), b) optionally recovering the obtained mixture of previous step in form of a polymer powder, wherein the polymer (C1) and the multi stage polymer (MP1) in step a) are in form of a dispersion in aqueous phase.
  12. The method according to any of claims 9 to 11, characterized in that the ratio r of the polymer (C1) in a composition comprising only the multistage polymer (MP1) and the polymer (C1) is between 7wt% and less than 25wt%, more advantageously between 10wt% and less than 24wt% and even more advantageously between 10wt% and less than 20wt%.
  13. The method according to any of claims 9 to 12 characterized in that the polymer (C1) at least 70wt% monomers chosen from C1 to C12 alkyl (meth)acrylates.
  14. A structural adhesive polymer composition comprising a composition according to any of claims 1 to 8, or made according the method of any of claims 9 to 13.
  15. Use a composition according to any of claims 1 to 8 for making a structural epoxy adhesive.

Description

[Field of the invention] The present invention relates to a composition suitable as epoxy adhesive composition comprising a multistage polymer in form of polymeric particles and a (meth)acrylic polymer its process of preparation and its use. In particular the present invention relates to a structural epoxy adhesive composition comprising a multistage polymer in form of polymeric particles made by a multistage process and a (meth)acrylic polymer its process of preparation and its use. More particularly the present invention relates to structural (epoxy adhesive composition made from a two part composition or a one part composition comprising a multistage polymer in form of polymeric particles made by a multistage process and a (meth)acrylic polymer its process of preparation and its use. [Technical problem] Structural adhesives are materials of high strength and performance. Their function is primary function is to hold structures together and to be capable of resisting high loads. Thermosetting epoxy adhesives are rubber-toughened systems that cure rapidly at room temperature to provide a crosslinked structural adhesive suitable for bonding metals, engineering plastics, and many other substrates with minimal surface preparation. They provide a high tensile shear and peel strength, chemical resistance, and impact strength. The formulation uses the addition of core-shell block and graft polymers, which swell in size in the adhesive formulation but do not dissolve. These additives give also improved spreading and flow properties to the adhesive. The core-shell polymer have to be distributed homogeneously throughout the adhesive in order to guaranty a satisfying impact performance of the adhesive. This homogenous distribution is not easily achieved with all kind of core shell impact modifiers. Additionally the elongation at break is relatively low for standard epoxy structural adhesives. The adhesion of such epoxy structural adhesives should be increased as well. The objective of the present invention is to propose a multistage polymer composition which is rapidly and easily dispersible in liquid and/or reactive epoxy resins suitable for epoxy adhesive compositions. An objective of the present invention is also to propose a multistage polymer composition which is easily dispersible in liquid and/or reactive resins in form of a polymer powder suitable for epoxy adhesive compositions. An additional objective of the present invention is to propose structural epoxy adhesive polymer composition that has improved impact performance and toughness and a high strength, while having at the same time an increased elongation at break. An additional objective of the present invention is to propose structural epoxy adhesive polymer composition that has satisfying impact performance and a high strength, while having at the same time an increased adhesion (lap shear). Another objective of the present invention is to propose a method for structural epoxy adhesive polymer composition which comprises a multistage polymer having a core-shell structure, that is easily dispersible in in liquid and/or reactive resins. Still another objective of the present invention is a method for preparing a liquid polymer composition comprising an epoxy component, a curing agent and a multistage polymer having a core-shell structure, with a homogenous distribution of the multistage polymer. Still a further objective of the present invention is the use of a liquid polymer composition comprising an epoxy component, a curing agent and a multistage polymer having a core-shell structure, with a homogenous distribution of the multistage polymer for preparing structural epoxy adhesive. [BACKGROUND OF THE INVENTION ]Prior art The document US2009/0308534 discloses a highly toughened two part structural epoxy adhesive composition. The composition comprises core-shell particles. The document WO2009/126862 discloses a one part epoxy based structural adhesive comprising toughening agents. The preferred toughening agents are core shell polymers. The document WO2012/021258 discloses an epoxy structural adhesive. The adhesive comprises toughening agents that are in some embodiment's core shell impact modifiers. The document WO2016/102666 discloses a composition comprising a multistage polymer. The composition comprises as well a (meth)acrylic polymer (P1) having a mass average molecular weight of less than 100 000g/mol, but with giving a specific ratio of the (meth)acrylic polymer (P1). None of the prior art documents discloses an epoxy adhesive composition comprising a multistage polymer in form of polymeric particles combined with an additional polymer having a specific molecular weight and weight ratio. [Brief description of the invention] Surprisingly it has been found that a polymer composition comprising a) a first part composition (P1) comprising a1) an epoxy resin,a2) a multistage polymer (MP1) having a core-shell structure,a3) a polymer (C1) that is a (m