Fluorine-containing blocked isocyanates

• US 6,509,433 B2
• Filed: 09/14/2001
• Issued: 01/21/2003
• Est. Priority Date: 09/20/2000
• Status: Expired due to Fees

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Gonzalez-Blanco, Juan, Koenig, Eberhard, Baumbach, Beate, Füssel, Christian
• Primary Examiner(s): SERGENT, RABON A
• Application Number:
  US09/955,228
• Publication Number:
  US 20020123642A1
• Time in Patent Office: 494 Days
• Field of Search: 528/45, 528/49, 528/67, 528/70, 252/182.2, 252/182.22, 560/115, 560/157, 560/158, 560/167, 560/330, 560/336, 560/349, 560/356
• US Class Current: 528/45
• CPC Class Codes: C08G 18/8074 Lactams
• CPC Class Codes: C08G 18/8087 containing halogen atoms
• CPC Class Codes: C08G 2150/20 Compositions for powder coatings
• CPC Class Codes: C09D 175/04 Polyurethanes

Abstract

The present invention relates to blocked fluorine-containing polyisocyanates which have a fluorine content, calculated as F=19, of 1.0 to 20.0 wt. %, preferably 4.0 to 10.0 wt. %, and are suitable for preparing stoving coatings having a water- and soil-repellent surface, wherein the fluorine-containing polyisocyanates are based on the reaction product of aliphatic polyisocyanates or polyisocyanate mixtures having an NCO content of 10 to 25 wt. % and a functionality of at least 2.5 with monofunctional isocyanate blocking agents and a fluorinated monoalcohols wherein

i) 75 to 95 equivalent-% of the isocyanate groups are reacted with isocyanate blocking agents,

ii) 5 to 25 equivalent-% of the isocyanate groups are reacted with fluorinated monoalcohols and

iii) the equivalents of i) and ii) add up to 100%.

The present invention also relates to a process for the preparation of these blocked fluorine-containing polyisocyanates and to their use as crosslinking agents in the preparation of polyurethane plastics, especially polyurethane coatings.

Claims

1. A blocked fluorine-containing polyisocyanate which has a fluorine content, calculated as F=19, of 1.0 to 20.0 wt. % and is suitable for preparing stoving coatings having a water- and soil-repellent surface, wherein the fluorine-containing polyisocyanate comprises the reaction product of an aliphatic polyisocyanate or polyisocyanate mixture having an NCO content of 10 to 25 wt. % and a functionality of at least 2.5 with a monofunctional isocyanate blocking agent and a fluorinated monoalcohol, which comprises the addition product of perfluoroethyl iodide, perfluorobutyl iodide or perfluorohexyl iodide onto allyl alcohol with subsequent hydro-deiodination to give the corresponding fluorinated alcohol wherein

i) 75 to 95 equivalent-% of the isocyanate groups are reacted with an isocyanate blocking agent,

ii) 5 to 25 equivalent-% of the isocyanate groups are reacted with said fluorinated monoalcohol and

iii) the equivalents of i) and ii) add up to 100%.

2. The blocked fluorine-containing polyisocyanate of claim 1 wherein the blocked fluorine-containing polyisocyanate has a fluorine content, calculated as F=19, of 4.0 to 10.0 wt. %.

3. A polyurethane plastic prepared from the blocked fluorine containing polyisocyanate of claim 1 and an isocyanate-reactive component.

4. A polyurethane coating composition containing the blocked fluorine-containing polyisocyanate of claim 1 and an isocyanate-reactive component.

5. A coated substrate prepared from the polyurethane coating composition of claim 4.

6. The coated substrate of claim 5 wherein the substrate is metal.

7. A process for the preparation of a blocked fluorine-containing polyisocyanate, which has a fluorine content, calculated as F=19, of 1.0 to 20.0 wt. % and is suitable for preparing stoving coatings having a water- and soil-repellent surface, which comprises initially introducing an aliphatic polyisocyanate or polyisocyanate mixture, optionally in a solvent, into a reaction vessel at a temperature of 50 to 70°

C. with stirring, subsequently adding a fluorinated monoalcohol, which comprises the addition product of perfluoroethyl iodide, perfluorobutyl iodide or perfluorohexyl iodide onto allyl alcohol with subsequent hydro-deiodination to give the corresponding fluorinated alcohol, reacting the mixture at 80 to 110°

C. until the calculated NCO content is reached and then reacting the remaining NCO groups with a corresponding amount of blocking agent at 70 to 110°

C.