Process for making low viscosity, fast curing silane terminated polymers

Patent metadata

Field	Value
Publication number	US-8987401-B2
Application number	US-201214119072-A
Country	US
Kind code	B2
Filing date	Jun 14, 2012
Priority date	Jun 30, 2011
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

Methods of producing a composition comprising a crosslinkable silane-terminated polymer having at least one crosslinkable silyl group in each molecule are provided. The method may comprise providing a polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule and having a number average molecular weight between about 100 and about 5,000, adding to the polymer a compound having a hydrogen-silicon bond and a crosslinkable silyl group in each molecule and a hydrosilylation catalyst to thereby carry out a hydrosilylation reaction to form a composition comprising hydrosilylated polymers, wherein the hydrosilylation reaction has a hydrosilylation efficiency greater than 50% as determined by 1 H-NMR, capping the hydrosilylated polymers by adding the hydrosilylated polymer to at least one isocyanate at an index of between about 100 and about 250, and reacting the isocyanate capped hydrosilylated polymer with a polyol having a nominal functionality of at least 2 to form the composition comprising a crosslinkable silane-terminated polymer.

First claim

What is claimed is:

1. A method of producing a composition comprising a crosslinkable silane-terminated polymer having at least one crosslinkable silyl group in each molecule, the method comprising:
providing a polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule and having a number average molecular weight between about 100 and about 5,000;
adding to the polymer a compound having a hydrogen-silicon bond and a crosslinkable silyl group in each molecule and a hydrosilylation catalyst to thereby carry out a hydrosilylation reaction to form a composition comprising hydrosilylated polymers, wherein the hydrosilylation reaction has a hydrosilylation efficiency greater than 50% as determined by 1 H-NMR;
capping the hydrosilylated polymers by adding the hydrosilylated polymer to at least one isocyanate at an index of between about 100 and about 250; and
reacting the isocyanate capped hydrosilylated polymer with a polyol having a nominal functionality of at least 2 to form the composition comprising a crosslinkable silane-terminated polymer.

2. The method of claim 1 , wherein the adding the hydrosilylated polymer to at least one isocyanate comprises:
forming a reaction mixture by adding the hydrosilylated polymers to the at least one isocyanate at a first temperature; and
subsequently heating the reaction mixture to a second temperature.

3. The method of claim 2 , wherein the first temperature is from about 20° C. to about 70° C. and the second temperature is from about 70° C. to about 100° C.

4. The method of claim 2 , wherein the capping of the hydrosilylated polymers is performed without the addition of a catalyst.

5. The method of claim 1 , wherein the polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule has a basicity between 0 and 4.7×10 −3 mgKOH/g.

6. The method of claim 5 , wherein the polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule has a basicity between 0 and 1.9×10 −3 mg KOH/g.

7. The method of claim 1 , wherein the isocyanate capped hydrosilylated polymers have an NCO number of between 2.69 and 3.18%.

8. The method of claim 7 , wherein the hydrosilylation reaction has a hydrosilylation efficiency greater than 80%.

9. The method of claim 1 , wherein the polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule comprises a propylene glycol monoallyl ether having a number average molecular weight between about 600 and about 1,000, and an OH number of between about 50 and about 90.

10. The method of claim 9 , wherein the isocyanate comprises at least one of 4,4′-, 2,4′ and 2,2′-isomers of diphenylmethane diisocyante, 2,4-toluene diisocyanate and 20% 2,6-toluene diisocyanate, aliphatic isocyanate or blends thereof.

11. The method of claim 9 , wherein the polyol comprises a polyether polyol.

12. The method of claim 11 , wherein the polyol comprises a polyether polyol based on propylene oxide.

13. A method of producing a composition comprising a crosslinkable silane-terminated polymer having at least one crosslinkable silyl group in each molecule, the method comprising:
providing a polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule, having a number average molecular weight between about 100 and about 5,000, and a basicity between 0 and 1.9×10 −3 mgKOH/g;
adding to the polymer a compound having a hydrogen-silicon bond and a crosslinkable silyl group in each molecule and a hydrosilylation catalyst to thereby carry out a hydrosilylation reaction to form a composition comprising hydrosilylated polymers, wherein the hydrosilylation reaction has a hydrosilylation efficiency greater than 50% as determined by 1 H-NMR;
capping the hydrosilylated polymer by exposing the hydrosilylated polymer to at least one isocyanate at an index of between about 100 and about 250; and
reacting the isocyanate capped hydrosilylated polymer with a polyol having a nominal functionality of at least 2 to form the composition comprising a crosslinkable silane-terminated polymer.

14. The method of claim 13 , wherein the polymer having at least one unsaturated group and at least one alcohol hydroxyl group in each molecule has a basicity between 0 and 1.4×10-3 mgKOH/g.

15. The method of claim 13 , wherein the capping the hydrosilylated polymers is performed without the addition of a catalyst.

16. An article comprising the crosslinkable silane-terminated polymer of claim 1 .

17. The article of claim 16 wherein the article is an elastomer, a sealant, an adhesive, a coating or a combination thereof.

Assignees

• Vyakaranam Kamesh R
• Zhang Ling
• Minnikanti Venkat S
• Duggal Rajat
• Koonce William A
• Singh Amarnath
• Athey Phillip S
• Dow Global Technologies Llc

Inventors

• Vyakaranam Kamesh R
• Zhang Ling
• Minnikanti Venkat S
• Duggal Rajat
• Koonce William A
• Singh Amarnath
• Athey Phillip S

Classifications

• C08G18/289

  containing silicon · CPC title

• C08G2190/00

  Compositions for sealing or packing joints · CPC title

• C08G18/10 Primary

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/718

  containing silicon · CPC title

• C08G18/7621

  being toluene diisocyanate including isomer mixtures · CPC title