EP0343523A2

Sealant compositions or coating mixtures containing functional silane or siloxane adhesion promoters nonreactive with blocked isocyanates.

Abstract

A sealant or coating composition admixture contains a blocked isocyanate-terminated prepolymer in which generally all of the NCO groups are blocked, a curing agent such as a polyamine or a polyimine, and a functional silane or siloxane nonreactive with blocked isocyanates. The sealants or coating compositions when cured have improved properties such as adhesion.

EP0343523A2, drawing sheet 1
Sheet 1 of 8

Term

Term ended

Projected expiry passed 19 May 2009, 17.3 years ago.

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20 claims: 1 independent, 19 dependent

  1. 1
    A sealant composition or coating admixture, comprising:a blend of a blocked isocyanate prepolymer, a functional silane or siloxane adhesion promoter non-­reactive with said blocked isocyanate-terminated prepoly­mer, and an effective amount of a polyamine or a poly­amine curing agent capable of curing the sealant composi­tion or the coating admixture, said blend being substan­tially free of organosilanes which are reactive with said blocked isocyanate prepolymer, the amount of said functional silane or siloxane adhesion promoter being from about 0.1 to about 10 parts by weight based upon 100 parts by weight of said prepolymer.
  2. 2
    A sealing composition or coating admixture according to Claim 1, wherein said functional silane adhesion promoter non-reactive with said blocked isocya­nate-terminated prepolymer has the formula or a siloxane derivative thereof, wherein R¹ is an aliphatic having from 1 to 16 carbon atoms, a cycloaliphatic having from 4 to 8 carbon atoms, or an aromatic or an alkyl substituted aromatic having from 6 to 15 carbon atoms, wherein R² is an ali­phatic having from 1 to 25 carbon atoms, or an aromatic or an alkyl substituted aromatic having from 6 to 15 carbon atoms, wherein R³, R⁴, and R⁵, independently, is an alkyl having from 1 to 10 carbon atoms, an aromatic or an alkyl substituted aromatic having from 6 to 12 carbon atoms, wherein "a" is 0, 1, or 2, wherein "b", "c", and "d", independently, is 0 or 1, wherein "a" + "b" + "c" + "d" = 3, and wherein X is an epoxy group, an isocyanato group, or a ketimine group.
  3. 3
    A sealing composition or coating admixture according to Claim 2, wherein X is an epoxy group, where­in said epoxy group is epoxy, glycidoxy, 2-alkylgly­cidoxy wherein said alkyl group has from 1 to 4 carbon atoms, or an epoxycycloalkylene wherein said alkylene has from 4 to 10 carbon atoms.
  4. 4
    A sealing composition or coating admixture according to Claim 3, wherein R¹ is an alkyl having from 2 to 6 carbon atoms, or a cycloalkyl having from 4 to 8 carbon atoms, wherein R² is an alkyl having from 1 to 25 carbon atoms, and wherein R³, R⁴, and R⁵, independently, is an alkyl having from 1 to 4 carbon atoms.
  5. 5
    A sealing composition or coating admixture according to Claim 4, wherein said epoxysilane adhesion promoter is glycidoxypropyltrimethoxysilane.
  6. 6
    A sealing composition or coating admixture according to Claim 3, wherein said adhesion promoter is a siloxane derivative of the compositions of Claim 3 and has from 2 to 50 repeating groups therein.
  7. 7
    A sealing composition or coating admixture according to Claim 5, wherein said adhesion promoter is a siloxane oligomer of glycidoxypropyltrimethoxysilane having from 2 to 50 siloxane repeating units.
  8. 8
    A sealing composition or coating admixture according to Claim 2, wherein X is an isocyanato group, wherein R¹ is an alkyl having from 2 to 6 carbon atoms, or a cycloalkyl having from 4 to 8 carbon atoms, wherein R² is an alkyl having from 1 to 25 carbon atoms, wherein R³, R⁴, and R⁵, independently is an alkyl having from 1 to 4 carbon atoms.
  9. 9
    A sealing composition or coating admixture according to Claim 8, wherein said adhesion promoter is isocyanatopropyltrimethoxysilane.
  10. 10
    A sealing composition or coating admixture according to Claim 8, wherein said adhesion promoter is a siloxane derivative of said isocyanato compound and has from 2 to 50 siloxane repeating units therein.
  11. 11
    A sealing composition or coating admixture according to Claim 9, wherein said adhesion promoter is a siloxane derivative of said isocyanatopropyltrimethoxy­silane and has from 2 to 50 siloxane repeating units therein.
  12. 12
    A sealing composition or coating admixture according to Claim 2, wherein X is a ketimine group, wherein said ketimine group has the formula wherein R⁶ and R⁷, independently, is an aliphatic having from 1 to 10 carbon atoms, an aromatic or an alkyl sub­stituted aromatic having from 6 to 15 carbon atoms, or hydrogen.
  13. 13
    A sealing composition or coating admixture according to Claim 12, wherein R¹ is an alkyl having from 2 to 6 carbon atoms, or a cycloalkyl having from 4 to 8 carbon atoms, wherein R² is an alkyl having from 1 to 25 carbon atoms, wherein R³, R⁴, and R⁵, independently, is an alkyl having from 1 to 4 carbon atoms.
  14. 14
    A sealing composition or coating admixture according to Claim 13, wherein said adhesion promoter is the methylisobutylketone ketimine of gamma-aminopropyl­trimethoxysilane.
  15. 15
    A sealing composition or coating admixture according to Claim 13, wherein said adhesion promoter is a siloxane derivative of said ketimine and has from 2 to about 50 siloxane repeating units therein.
  16. 16
    A sealing composition or coating admixture according to Claim 14, wherein said adhesion promoter is a siloxane of said ketimine and has from 2 to 50 siloxane repeating units therein.
  17. 17
    A sealing composition or coating admixture according to Claim 2, wherein said sealing composition or coating admixture is cured.
  18. 18
    A sealing composition or coating admixture according to Claim 4, wherein said sealing composition or coating admixture is cured.
  19. 19
    A sealing composition or coating admixture according to Claim 8, wherein said sealing composition or coating admixture is cured.
  20. 20
    A sealing composition or coating admixture according to Claim 13, wherein said sealing composition or coating admixture is cured.
Independent claims20