Two-component polyurethane hot-melt adhesive with high initial and final strength

Patent metadata

Field	Value
Publication number	US-10087349-B2
Application number	US-201515502817-A
Country	US
Kind code	B2
Filing date	Aug 17, 2015
Priority date	Sep 5, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A two-pack polyurethane adhesive for semi-structural and structural adhesive bonds which are applied in melt form and have a high handling strength wherein the two-pack polyurethane adhesive includes a first pack A containing at least one polyester A1 which is solid at room temperature and at least one polyol A2 having a hydroxyl group functionality greater than 2.0, and a second pack B containing polyurethane prepolymers having isocyanate groups.

First claim

The invention claimed is:

1. A two-pack polyurethane adhesive comprising a first pack A containing at least one polyester A1 which is solid at room temperature and at least one polyol A2 having a hydroxyl group functionality greater than 2.0, and a second pack B containing polyurethane prepolymers having isocyanate groups.

2. The two-pack polyurethane adhesive according to claim 1 , wherein the polyesters A1 have a functionality of at least one hydroxyl end group.

3. The two pack polyurethane adhesive according to claim 1 , wherein the glass transition temperature or the melting point of A1 is above 23° C.

4. The two-pack polyurethane adhesive according to claim 1 , wherein the polyol A2 is selected from the group including polyethers, polyacrylates, polycarbonates or hydroxyl-terminated polyolefins or polyesters.

5. The two-pack polyurethane adhesive according to claim 1 , wherein the polyol A2 comprises polyesters.

6. The two-pack polyurethane adhesive according to claim 1 , wherein the polyurethane prepolymers having isocyanate groups consist of the reaction product of at least one polyol with an excess of polyisocyanates.

7. The two-pack polyurethane adhesive according to claim 6 , wherein polyisocyanates used are di- or multifunctional, aromatic, aliphatic or cycloaliphatic isocyanates, and carbodiimide-modified isocyanates or isocyanate-terminated prepolymers.

8. A method for producing adhesive bonds based on the two-pack polyurethane adhesive of claim 1 , comprising the separate melting of the A and B packs, depending on the melt viscosity, at temperatures above the melting points and/or glass transition points of all the constituents in the two packs, mixing of the two liquid packs A and B and subsequent application to the substrates to be bonded.

9. The method according to claim 8 , wherein the two liquid packs A and B are mixed with one another in a mixing ratio between 1:9 and 9:1 percent by volume.

10. A two-pack polyurethane adhesive comprising a first pack A containing at least one polyester A1 which is solid at room temperature and at least one polyol A2 having a hydroxyl group functionality greater than 2.0 and additives, and a second pack B containing polyurethane prepolymers having isocyanate groups and additives.

11. The two-pack polyurethane adhesive according to claim 10 , wherein the polyesters A1 have a functionality of at least one hydroxyl end group.

12. The two pack polyurethane adhesive according to claim 10 , wherein the glass transition temperature or the melting point of A1 is above 23° C.

13. The two-pack polyurethane adhesive according to claim 10 , wherein the polyol A2 is selected from the group including polyethers, polyacrylates, polycarbonates, hydroxyl-terminated polyolefins, or polyesters.

14. The two-pack polyurethane adhesive according to claim 10 , wherein the polyol A2 comprises polyesters.

15. The two-pack polyurethane adhesive according to claim 10 , wherein the polyurethane prepolymers having isocyanate groups consist of the reaction product of at least one polyol with an excess of polyisocyanates.

16. The two-pack polyurethane adhesive according to claim 15 , wherein polyisocyanates used are di- or multifunctional, aromatic, aliphatic or cycloaliphatic isocyanates, and carbodiimide-modified isocyanates or isocyanate-terminated prepolymers.

17. The two-pack polyurethane adhesive according to claim 10 , wherein the additives for pack A and/or B are selected from the group comprising fillers, rheology modifiers, pigments or dyes, nonfunctionalized polymers, flame retardants, tackifiers, waxes, plasticizers, desiccants, adhesion promoters, fibers, latent hardeners, hydrolysis stabilizers, and ageing stabilizers and auxiliaries.

18. A method for producing adhesive bonds based on the two-pack polyurethane adhesive of claim 10 , comprising the separate melting of the A and B packs, depending on the melt viscosity, at temperatures above the melting points and/or glass transition points of all the constituents in the two packs, mixing of the two liquid packs A and B and subsequent application to the substrates to be bonded.

19. The two pack polyurethane adhesive according to claim 11 , wherein the glass transition temperature or the melting point of A1 is above 23° C.

20. The two-pack polyurethane adhesive according to claim 11 , wherein the polyol A2 is selected from the group including polyethers, polyacrylates, polycarbonates or hydroxyl-terminated polyolefins or polyesters.

Assignees

• Evonik Degussa Gmbh

Inventors

• Brenner Gabriele
• Drees Birgit
• Cron Christina
• Fuchs Kerstin

Classifications

• C08G18/4202

  Two or more polyesters of different physical or chemical nature (C08G18/44 takes precedence) · CPC title

• C09J175/06 Primary

  from polyesters · CPC title

• C08G18/4238

  derived from dicarboxylic acids and dialcohols · CPC title

• C08G18/4216

  from mixtures or combinations of aromatic dicarboxylic acids and aliphatic dicarboxylic acids and dialcohols · CPC title

• C08G18/7671 Primary

  containing only one alkylene bisphenyl group · CPC title