Acid catalyzed, toughened epoxy adhesives

{
  "publication_number": "US4846905A",
  "country": "US",
  "kind": "A",
  "title": "Acid catalyzed, toughened epoxy adhesives",
  "abstract": "Disclosed is a thermally-curable, one-part epoxy adhesive composition comprising: (1) a glycidyl ether epoxide having a048477475 n epoxy functionality grater than one and a molecular weight between about 150 and 10,000; (2) a catalyst comprising (i) an acid of the formula H + SbF 5 X - wherein X is halogen, hydroxy, or --OR where --OR is the residue of an aliphatic or aromatic alcohol having a molecular weight less than about 10,000 and (ii) N,N-diethyl-o-toluidine; (3) an aliphatic or non-aromatic cyclic polyol having about 2 to 18 carbon atoms, at least two hydroxy groups of which are primary or secondary, and being free of electron-withdrawing substituents, amine substituents, or large substituents that cause steric hindrance in the α-position in relation to the carbon attached to the methylol group of the polyol; and (4) a toughening agent that does not react with the epoxide during curing and has an epoxide compatible component and an epoxide incompatible component.",
  "claims": [
    "1. A thermally-curable, one-part epoxy adhesive composition comprising: (1) a glycidyl ether epoxide having an epoxy functionality greater than one and a molecular weight between about 150 and 10,000; (2) a catalyst comprising (i) an acid of the formula H + SbF 5 X - wherein X is halogen, hydroxy, or --OR where --OR is the residue of an aliphatic or aromatic alcohol having a molecular weight less than about 10,000 and (ii) N,N- diethyl-o-toluidine; (3) an aliphatic or non-aromatic cyclic polyol having about 2 to 18 carbon atoms, at least two hydroxy groups of which are primary or secondary, and being free of electron-withdrawing substituents, amine substituents, or large substituents that cause steric hindrance in the α-position in relation to the carbon attached to the methylol group of the polyol; and (4) a toughening agent that does not react with the epoxide during curing and has an epoxide compatible component and an epoxide incompatible component.",
    "2. The composition of claim 1 wherein the polyol is present in an amount sufficient to provide an hydroxy to epoxy ratio between about 0.5:1 and 1.1:1.",
    "3. The composition of claim 2 wherein said hydroxy to epoxy ratio is between about 0.7:1 and 0.8:1.",
    "4. The composition of claim 1 wherein the molar ratio of said acid to N,N-diethyl-o-toluidine is between about 1:1.5 and 1:10.",
    "5. The composition of claim 4 wherein said molar ratio is between about 1:2 and 1:6.",
    "6. The composition of claim 1 wherein said toughening agent is present at between about 3% and 35% by weight of the epoxide.",
    "7. The composition of claim 1 wherein said toughening agent is a polymeric compound having both a rubbery phase and a thermoplastic phase.",
    "8. The composition of claim 7 wherein said toughening agent is a graft polymer having a polymerized, diene, rubbery core and a shell grafted thereto of an acrylic acid ester, a methacrylic acid ester, a monovinyl aromatic hydrocarbon, or a mixture thereof.",
    "9. The composition of claim 8 wherein said rubbery core comprises polymerized butadiene or a polymerized mixture of butadiene and styrene.",
    "10. The composition of claim 9 wherein said shell comprises a methacrylic acid ester.",
    "11. The composition of claim 10 wherein said methacrylic acid ester comprises a lower alkyl substituted methacrylate.",
    "12. The composition of claim 9 wherein said shell comprises a monovinyl aromatic hydrocarbon.",
    "13. The composition of claim 12 wherein said hydrocarbon is selected from styrene, alpha-methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene, and ethylchlorostyrene.",
    "14. The composition of claim 7 wherein said toughening agent is a core-shell polymer wherein the core is a rubbery polyacrylate polymer having a glass transition temperature below about 0° C. and the shell is grafted thereto and is a thermoplastic polyacrylate polymer having a glass transition temperature above about 25° C.",
    "15. The composition of claim 14 wherein said core is selected from polybutylacrylate and polyisooctylacrylate and said shell is polymethylmethacrylate.",
    "16. The composition of claim 7 wherein said toughening agent is an elastomeric particle having a T g below about 25° C. that is a polymerized mixture of free-radical polymerizable monomers and a polymeric stabilizer that is soluble in the epoxide.",
    "17. The composition of claim 1 wherein X is the residue of an alkylene glycol.",
    "18. The composition of claim 1 wherein X is 2-(2-hydroxyethoxy)ethoxy.",
    "19. The composition of claim 1 wherein said polyol is an alkylene glycol.",
    "20. The composition of claim 1 wherein said polyol is 1,4-cyclohexanedimethanol.",
    "21. The composition of claim 1 wherein said epoxide has a molecular weight between about 300 and 1,000.",
    "22. The composition of claim 1 wherein said epoxide is a diglycidyl ether of bisphenol A or a diglycidyl ether of bisphenol F."
  ],
  "cpc": [
    "C08G 59/686",
    "C08G 59/62",
    "C08L 63/00",
    "C09J 5/00"
  ],
  "assignees": [
    "MINNESOTA MINING & MFG"
  ],
  "filing_date": "1988-04-06",
  "publication_date": "1989-07-11",
  "grant_date": "1989-07-11",
  "priority_date": "1988-04-06",
  "application_number": "US-17814888-A",
  "family_id": "22651394",
  "citations": [
    "US3496250A",
    "US4503211A",
    "US4524181A",
    "US4553982A",
    "US4668736A",
    "US4775734A"
  ]
}