HIGH-STRENGTH POLYURETHANE ADHESIVE

• US 20090266482A1
• Filed: 05/11/2009
• Published: 10/29/2009
• Est. Priority Date: 11/15/2006
• Status: Abandoned Application

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: Henkel AG & Co KGaA
• Inventors: Mosshammer, Gerhard, Garmann, Helga, Puck, Claus-Heinrich
• Application Number:
  US12/463,680
• Publication Number:
  US 20090266482A1
• Time in Patent Office: Days
• US Class Current: 156/275.500
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/307 Atmospheric humidity
• CPC Class Codes: C08G 18/36 Hydroxylated esters of higher fatty acids
• CPC Class Codes: C08G 18/6696 with compounds of group C08G18/36 or hydroxylated esters of higher fatty acids of C08G18/38
• CPC Class Codes: C09J 175/04 Polyurethanes

Abstract

The invention relates to a method for adhesively bonding substrates together that contains irregularities on the surface of the substrates. The adhesive is particularly suitable for adhesively bonding thin flexible substrates onto a rigid substrates.

Claims

1. A process for bonding flat substrates with a moisture-crosslinkable one component polyurethane-based adhesive comprising:

a) applying the adhesive onto a first substrate at temperature below 50°

C.;

b) optionally, storing the coated substrate;

c) bringing a second substrate in contact with the adhesive coated on the first substrate;

d) curing the adhesive at temperature of 50°

C. and 250°

C.;

wherein the adhesive foams during curing.

2. The process according to claim 1, wherein the adhesive has a viscosity between 500 and 150,000 mPas at 30°

C.

3. The process according to claim 1, wherein the adhesive is applied at a temperature of 15°

C. to 40°

C.

4. The process according to claim 1, wherein the curing of the adhesive is at a temperature of 70°

C. to 200°

C.

5. The process according to claim 1, wherein step d is conducted from 10 seconds to 30 minutes.

6. The process according to claim 1, wherein the substrates are selected from the group consisting of plastic film, wood and composites.

7. The process according to claim 6, wherein the surface of the substrate is uneven.

8. The process according to claim 1, wherein an adhesive is applied at room temperature and air humidity of up to 95%.

9. The process according to claim 1, wherein the adhesive, after curing, has a density between 0.3 g/cm³ up to 1.10 g/cm³.

10. The process according to claim 1, wherein step b occurs for a period of 0.5 to 24 hours at a temperature below 30°

C.

11. The process according to claim 1 wherein the curing is conducted with a heatable cylinder.

12. The process according to claim 10, wherein the curing conducted with a heatable press.

13. The process according to claim 1, wherein in step b, the applied adhesive has an open time greater than 3 hours at room temperature.

14. A liquid, moisture-curable one component polyurethane adhesive comprising:

a) a reaction product of 20 to 50 parts by weight of an oleochemical polyol,

b) 0 to 15 parts by weight of a polyether polyol or polyester polyol with an M_n between 300 and 15000; and

c) 80 to 40 parts by weight of a polyisocyanate;

wherein the adhesive can be stored in thin layers at room temperature for 1 to 24 hours and subsequently crosslink at a temperature of 70 to 200°

C.

15. The adhesive according to claim 14, which after crosslinking, has a density between 0.30 g/cm³ to 1.10 g/cm³.

16. The adhesive according to claim 14, wherein and the polyisocyanate is 50 to 75 parts by weight.

17. The adhesive according to one of claim 14, wherein the polyol is a castor oil or polypropylene glycol and the polyisocyanate is aromatic isocyanate.

18. The adhesive according to claim 14, wherein the adhesive comprises a polyol with a functionality of 3 to 10, and a catalyst.

19. The adhesive according to 14, wherein the open time of the adhesive is greater than 3 hours at a temperature below 50°

C.