Moisture cured reactive hot melt adhesive with monofunctional reactants as grafting agents

• US 20040079482A1
• Filed: 10/24/2002
• Published: 04/29/2004
• Est. Priority Date: 10/24/2002
• Status: Active Grant

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: National Starch and Chemical Investment Holding Corporation
• Inventors: Zhang, Yue S., Hung, Ju-Ming, Chu, Wayne K.
• Granted Patent: US 7,112,631 B2
• Time in Patent Office: Days
• US Class Current: 156/327
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/282 Alkanols, cycloalkanols or arylalkanols including terpenealcohols
• CPC Class Codes: C08G 18/307 Atmospheric humidity
• CPC Class Codes: C08G 18/4063 Mixtures of compounds of group C08G18/62 with other macromolecular compounds
• CPC Class Codes: C08G 2170/20 Compositions for hot melt adhesives
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

High green strength reactive hot melt adhesives are prepared using crystalline monofunctional reactants.

Claims

1. A polyurethane hot melt adhesive composition comprising polyisocyanate, one or more polymeric polyols, a crystalline monofunctional reactant, and optionally a thermoplastic polymer.

2. The adhesive of claim 1, wherein the thermoplastic polymer is selected from the group comprising functional thermoplastic polymers, nonfunctional thermoplastic polymers and mixtures thereof.

3. The adhesive of claim 2, wherein the thermoplastic polymer is selected from the group comprising acrylic polymers, functional acrylic polymers, non-functional acrylic polymers, hydroxy functional acrylic polymers, polyvinyl acetate, polyvinyl chloride, methylene polyvinyl ether, cellulose acetate, styrene acrylonitrile, amorphous polyolefin, thermoplastic urethane, polyacrylonitrile, polybutadiene, isobutylene diol and mixtures thereof.

4. The adhesive of claim 1, wherein the reactant is selected from the group comprising hydroxyl reactants, carboxyl reactants, thiol, amine and mixtures thereof.

5. The adhesive of claim 4, wherein the reactant is selected from the group comprising polymeric reactants, non-polymeric reactants and mixtures thereof.

6. The adhesive of claim 4, further comprising a polyether polyol.

7. The adhesive of claim 4, further comprising a polyester polyol.

8. The adhesive of claim 4, further comprising a polyester polyol and a polyether polyol.

9. The adhesive of claim 4, wherein the reactant is selected from the group comprising a low molecular weight linear polyethylene monoalcohol, polyethylene-block-polyethylene glycol, monol-terminated ring-opened polyesters, monol-terminated ring-opened polyamides, or mixtures thereof.

10. The adhesive of claim 9, wherein the reactant is a low molecular weight linear polyethylene monoalcohol.

11. The adhesive of claim 4, wherein the adhesive comprises from about 0.1 to about 30 wt % of the reactant.

12. The adhesive of claim 11, wherein the adhesive comprises from about 5 wt % to about 20 wt % of the reactant.

13. The adhesive of claim 4, further comprising plasticizers, compatible tackifiers, curing catalysts, dissociation catalysts, fillers, anti-oxidants, pigments, adhesion promoters, stabilizers, aliphatic C₅-C₁₀ terpene oligomers, rosin, rosin derivatives, rosin ester, aliphatic hydrocarbons, aromatic hydrocarbons aromatically modified aliphatic hydrocarbons, terpenes, terpene phenol, modified terpene, high molecular weight hindered phenols, multifunctional phenols, sulfur-containing phenol, phosphorous-containing phenol, terpene oligomers, DMDEE, paraffin waxes, microcrystalline waxes, castor oil, hydrogenated castor oil, fire retardant additives, boron compound, aluminum hydroxide, antimony trioxide, halogen compounds, halogen-containing phosphate compounds, tris(chloroethyl)phosphate, tris(2,3-dichloropropyl)-phosphate, ethylenebistetrabromophthalimide, tris(2,3-dibromopropyl)-isocyanurate and mixtures thereof.

25. A method of bonding materials together which comprises applying the reactive hot melt adhesive composition of claim 5 in a liquid form to a first substrate, bringing a second substrate in contact with the composition applied to the first substrate, and subjecting the compositions to conditions which will allow the compositions to cool and cure to an irreversible solid form, the conditions comprising moisture.

26. The method of claim 25, wherein the reactant is selected from the group comprising hydroxyl reactants, carboxyl reactants, and mixtures thereof.

27. The method of claim 26, wherein the reactant is selected from the group comprising polymeric reactants, non-polymeric reactants and mixtures thereof.

28. The method of claim 27, wherein the reactant is selected from the group comprising a low molecular weight linear polyethylene monoalcohol, polyethylene-block-polyethylene glycol, monol-terminated ring-opened polyesters, or mixtures thereof.

29. The method of claim 28, wherein the adhesive comprises from about 0.1 to about 30 wt % of the reactant.

30. An article of manufacture comprising the adhesive of claim 1.

14. A method of improving the set speed of a polyurethane adhesive comprising adding an effective amount of a crystalline monofunctional reactant to an adhesive formulation, wherein the adhesive comprises a thermoplastic polymer.

15. The method of claim 14, wherein the thermoplastic polymer is selected from the group comprising functional thermoplastic polymers, non-functional thermoplastic polymers and mixtures thereof.

16. The adhesive of claim 15, wherein the thermoplastic polymer is selected from the group comprising acrylic polymers, functional acrylic polymers, non-functional acrylic polymers, hydroxy functional acrylic polymers, polyvinyl acetate, polyvinyl chloride, methylene polyvinyl ether, cellulose acetate, styrene acrylonitrile, amorphous polyolefin, thermoplastic urethane, polyacrylonitrile, polybutadiene, isobutylene diol, and mixtures thereof.

17. The method of claim 14, further comprising a polyether polyol.

18. The method of claim 14, further comprising a polyester polyol.

19. The method of claim 14, further comprising a polyester polyol and a polyether polyol

20. The method of claim 14, wherein the reactant is selected from the group comprising hydroxyl reactants, carboxyl reactants, and mixtures thereof.

21. The method of claim 20, wherein the reactant is selected from the group comprising a low molecular weight linear polyethylene monoalcohol, polyethylene-block-polyethylene glycol, monol-terminated ring-opened polyesters, or mixtures thereof.

22. The method of claim 21, wherein the reactant is a low molecular weight polyethene monoalcohol.

23. The method of claim 21, wherein the adhesive comprises from about 0.1 to about 30 wt % of the reactant.

24. The method of claim 23, wherein the adhesive comprises from about 5 to about 20 wt % of the reactant.