Thermally reversible hot melt adhesive composition containing multifunctional diene and dienophile compounds

1. A thermally reversible hot melt adhesive comprising:

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester having a plurality of repeating ester groups within the backbone, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether having a plurality of repeating O atoms within the backbone, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof;

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile prepolymer L-(Y) Q having a molecular weight greater than 1,000 g/mol, wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)styrene, aliphatic (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, or mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero; and

wherein at least one of P or Q has a value greater than 2.0.

2. The thermally reversible hot melt adhesive of claim 1 , wherein at least one of P or Q has a value less than 3.0.

3. The thermally reversible hot melt adhesive of claim 2 , wherein the sum of the P and the Q has a value equal to or greater than 5.0.

4. A thermally reversible hot melt adhesive comprising:

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof;

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile prepolymer L-(Y) Q having a molecular weight greater than 1,000 g/mol, wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, or mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero;

wherein at least one of P or Q has a value greater than 2.0 and at least one multifunctional diene monomer/prepolymer is

or a combination thereof.

5. A thermally reversible hot melt adhesive comprising:

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof;

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile prepolymer L-(Y) Q having a molecular weight greater than 1,000 g/mol, wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, or mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero;

wherein at least one of P or Q has a value greater than 2.0 and at least one multifunctional dienophile monomer/prepolymer is

wherein the molecular weight of the polyester polyol segment is from about 2000 to about 7000,

wherein the molecular weight of the polyether polyol segment is from about 1000 to 18,000, or a combination thereof.

6. The adhesive of claim 1 , further comprising a thermoplastic polymer.

7. The adhesive of claim 6 , wherein the thermoplastic polymer contains acid or hydroxyl groups.

8. A thermally reversible hot melt adhesive comprising:

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, aliphatic (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof;

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile prepolymer L-(Y) Q , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, or mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero; and

wherein at least one of P or Q has a value greater than 2.0; and

c) a poly(meth)acrylate polymer.

9. A method for bonding substrates together comprising: heating the thermally reversible hot melt adhesive composition of claim 1 above the diene/dienophile bond dissociation temperature to form an uncrosslinked adduct, applying the uncrosslinked adduct onto a first substrate, bringing a second substrate in contact with the adduct applied to the first substrate, and cooling the applied adduct, whereby the adduct cures to bond said first substrate to said second substrate.

10. The method of claim 9 wherein at least one substrate is paper, plastic, wood, textile, foam, glass, metal, composite or ceramic.

11. An article of manufactured comprising the adhesive of claim 1 .

12. An article, comprising:

a substrate;

a layer of thermally reversible primer bonded to the substrate; and

a layer of adhesive different from the primer bonded to the primer, wherein the primer comprises:

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is selected from the group consisting of (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof; and

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile monomer/prepolymer L-(Y) Q having a molecular weight greater than 1,000 g/mol, wherein

i) L is selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero; and

c) optionally, a solvent

wherein the average P value for a) is greater than 2.1, or the average Q value for b) is greater than 2.1, or the average P value for a) is greater than 2.1 and the average Q value for b) is greater than 2.1.

13. The article of claim 12 , wherein said article is a book, packaging film, rigid panel, furniture, window, footwear, car headlamp, bonded textile/fabric for car trim or clothing.

14. The hot melt adhesive of claim 1 wherein (poly)ester L comprises one or more OH groups or (poly)ether L comprises one or more OH groups.

15. The hot melt adhesive of claim 1 wherein the average P value for a) is greater than 2.1, or the average Q value for b) is greater than 2.1, or the average P value for a) is greater than 2.1 and the average Q value for b) is greater than 2.1.

16. The hot melt adhesive of claim 1 wherein L of the multifunctional diene monomer/prepolymer L-(X) P is polyester from the reaction of one or more polyhydric alcohols with one or more polycarboxylic acids.

17. A compound selected from:

wherein the molecular weight of the polyester polyol segment is from about 2000 to about 7000, and

wherein the molecular weight of the polyether polyol segment is from about 1000 to 18,000.

18. The thermally reversible hot melt adhesive of claim 1 wherein for the at least one multifunctional diene monomer/prepolymer L-(X) P , L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof.

19. The thermally reversible hot melt adhesive of claim 1 wherein for the at least one multifunctional diene monomer/prepolymer L-(X) P , L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester having a plurality of repeating ester groups within the backbone, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether having three or more O atoms within the backbone, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof.

20. The article of claim 12 wherein the primer comprises

a) at least one multifunctional diene monomer/prepolymer L-(X) P , wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester having a plurality of repeating ester groups within the backbone, (poly)carbonate, (poly)amide, (poly)imide, (poly)styrene, (poly)ether having a plurality of repeating O atoms within the backbone, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, and mixtures thereof;

ii) X is a diene containing one or more of acyclic 1,3-diene, cyclopentadiene, cyclohexadiene, furan, fulvene, pyrrole, naphthalene and anthracene; and

iii) P is greater than zero;

b) at least one multifunctional dienophile prepolymer L-(Y) Q having a molecular weight greater than 1,000 g/mol, wherein

i) L is independently selected from the group consisting of a (poly)urethane, (poly)urea, (poly)ester, (poly)carbonate, (poly)amide, (poly)styrene, aliphatic (poly)ether, (poly)(meth)acrylate, (poly)olefin, (poly)siloxane, copolymers of above, including copolymers of maleic anhydride, or mixtures thereof; and

ii) Y is a dienophile containing one or more of a maleimide, isomaleimide, citraconimide, itaconimide, maleate, fumarate, acrylate, methacrylate, cyanoacrylate, benzoquinone, benzoquinone oxime, benzoquinone imine, naphthaquinone, alkylidene malonate, alkyne containing electron withdrawing groups and mixtures thereof; and

iii) Q is greater than zero; and

wherein at least one of P or Q has a value greater than 2.0.