Two component polyurethane composition

Patent metadata

Field	Value
Publication number	US-9896609-B2
Application number	US-201414785098-A
Country	US
Kind code	B2
Filing date	May 14, 2014
Priority date	May 15, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The present invention relates to a polyurethane composition consisting of a first and a second component, wherein the first component comprises an alkoxylated aromatic diol, a low molecular weight aliphatic or cycloaliphatic diol and a specific polybutadiene polyol in specific ratios. The cured composition is characterized by having good adhesive characteristics, a strength that is only slightly dependent upon the temperature in the temperature range of −35 to +85° C. and high strength and elasticity. It is particularly suitable as a structural adhesive for bonding two substrates.

First claim

The invention claimed is:

1. A polyurethane composition consisting of a first and a second component; wherein
the first component comprises
at least one alkoxylated aromatic diol A1 with an average molar mass in the range of 300 to 1000 g/mol,
at least one aliphatic or cycloaliphatic diol A2 with a molar mass in the range of 90 to 200 g/mol, which is not a linear alkylene diol with two primary OH groups,
at least one polybutadiene polyol A3 with an average OH functionality in the range of 2.3 to 2.7, and with an average molar mass in the range of 2500 to 3000 g/mol, and

the second component comprises
at least one polyisocyanate;

wherein the diol A1, the diol A2 and the polybutadiene polyol A3 are present in a quantity such that
the weight ratio A1/A2 falls in the range of 0.1 to 1,
the weight ratio A3/(A1+A2) falls in the range of 3 to 9, and
the fraction of polybutadiene polyol A3, based on all polyols present in the first component, falls in the range of 50 to 90 wt.-%.

2. The polyurethane composition according to claim 1 , wherein the alkoxylated aromatic diol A1 is a propoxylated bisphenol A or a propoxylated bisphenol F.

3. The polyurethane composition according to claim 1 , wherein the aliphatic or cycloaliphatic diol A2 is selected from the group consisting of 1,3-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 2,4-pentanediol, 2-methyl-1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,2-hexanediol, 3-methyl-1,5-pentanediol, 1,2-octanediol, 3,6-octanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,7-dimethyl-3,6-octandiol, 1,4-cyclohexanediol, 1,3-cyclohexane dimethanol and 1,4-cyclohexane dimethanol.

4. The polyurethane composition according to claim 1 , wherein the first component additionally comprises a monoalcohol A4 with a molar mass in the range of 140 to 340 g/mol, wherein the monoalcohol A4 is present in a quantity such that the weight ratio A4/(A1+A2) falls in the range of 0.1 to 0.5.

5. The polyurethane composition according to claim 1 , wherein the polyisocyanate is a form of 4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate liquid at room temperature and arbitrary mixtures of these isomers (MDI) in the form of polymeric MDI or MDI with fractions of oligomers or derivatives.

6. The polyurethane composition according to claim 1 , wherein the second component does not contain a polyurethane polymer with isocyanate groups.

7. The polyurethane composition according to claim 1 , wherein the first component contains no polyester polyols.

8. The polyurethane composition according to claim 1 , wherein the first component contains no castor oil-based polyols.

9. The polyurethane composition according to claim 1 , wherein the first component contains
30 to 90 wt.-% of the total of diol A1, diol A2 and polybutadiene polyol A3, and
10 to 70 wt.-% fillers,
and optionally additional constituents.

10. The polyurethane composition according to claim 1 , wherein the second component contains 90 to 100 wt.-% of a form liquid at room temperature of 4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate and arbitrary mixtures of these isomers (MDI).

11. The polyurethane composition according to claim 1 , wherein the mixing ratio in parts by weight between the first and second component falls in the range of 10:1 to 1:1.

12. A method for bonding a first substrate with a second substrate, comprising the steps:
mixing the first and the second component of a polyurethane composition according to claim 1 ,
applying the mixed polyurethane composition to at least one of the substrate surfaces to be bonded,
fitting the substrates to be bonded together within the open time,
curing the polyurethane composition.

13. The product resulting from the bonding method according to claim 12 .

14. A method for filling joints and gaps in a substrate, comprising the steps:
a) mixing the first component and the second component of a polyurethane composition according to claim 1 ,
b) applying the mixed polyurethane composition in the joint to be covered between two substrates or in the gap to be filled on the surface of a substrate,
c) curing the polyurethane composition in the joint or the gap.

15. The polyurethane composition according to claim 2 , wherein the aliphatic or cycloaliphatic diol A2 is selected from the group consisting of 1,3-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 2,4-pentanediol, 2-methyl-1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,2-hexanediol, 3-methyl-1,5-pentanediol, 1,2-octanediol, 3,6-octanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,7-dimethyl-3,6-octandiol, 1,4-cyclohexanediol, 1,3-cyclohexane dimethanol and 1,4-cyclohexane dimethanol.

16. The polyurethane composition according to claim 3 , wherein the first component additionally comprises a monoalcohol A4 with a molar mass in the range of 140 to 340 g/mol, wherein the monoalcohol A4 is present in a quantity such that the weight ratio A4/(A1+A2) falls in the range of 0.1 to 0.5.

17. The polyurethane composition according to claim 4 , wherein the polyisocyanate is a form of 4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate liquid at room temperature and arbitrary mixtures of these isomers (MDI) in the form of polymeric MDI or MDI with fractions of oligomers or derivatives.

18. The polyurethane composition according to claim 5 , wherein the second component does not contain a polyurethane polymer with isocyanate groups.

19. The polyurethane composition according to claim 6 , wherein the first component contains no polyester polyols.

20. The polyurethane composition according to claim 1 ,
wherein the weight ratio A1/A2 falls in the range of 0.3 to 0.7,
wherein the weight ratio A3/(A1+A2) falls in the range of 5 to 8, and
wherein the fraction of polybutadiene polyol A3, based on all polyols present in the first component, falls in the range of 75 to 90 wt.-%.

21. The polyurethane composition according to claim 1 , wherein the alkoxylated aromatic diol A1 is a propoxylated bisphenol A.

22. The polyurethane composition according to claim 4 , wherein the monoalcohol A4 is present in a quantity such that the weight ratio A4/(A1+A2) falls in the range of 0.2 to 0.4.

23. The polyurethane composition according to claim 1 , wherein the first component contains
50 to 80 wt.-% of the total of diol A1, diol A2 and polybutadiene polyol A3, and
20 to 40 wt.-% fillers,
and optionally additional constituents.

24. The polyurethane composition according to claim 1 , wherein the second component contains 95 to 100 wt.-% of a form liquid at room temperature of 4,4′-, 2,4′- or 2,2′-diphenylmethane diisocyanate and arbitrary mixtures of these isomers (MDI).

25. The polyurethane composition according to claim 1 , wherein the mixing ratio in parts by weight between the first and second component falls in the range of 7.5:1 to 2:1.

26. The polyurethane composition according to claim 1 , wherein the polyurethane composition consists of the first component and the second component.

27. The polyurethane composition according to claim 1 , wherein after the first and second components are mixed, the tensile shear strength at 85° C. of the resulting composition is in a range of 2.1 to 4.2 MPa.

Assignees

• Sika Tech Ag

Inventors

• Roock Wolfgang
• Kelch Steffen
• Heidtmann Matthias

Classifications

• C09D175/14

  Polyurethanes having carbon-to-carbon unsaturated bonds · CPC title

• B32B2250/02

  2 layers · CPC title

• C09J175/14 Primary

  Polyurethanes having carbon-to-carbon unsaturated bonds · CPC title

• B32B2255/26

  Polymeric coating · CPC title

• C08G18/3206

  aliphatic · CPC title