Blocked polyisocyanates curing free from elimination products for dualcure systems

• US 20060052573A1
• Filed: 09/02/2005
• Published: 03/09/2006
• Est. Priority Date: 09/08/2004
• Status: Active Grant

• Current Assignee: Allnex Netherlands B.V. (Allnex (Luxembourg) & Cy SCA)
• Original Assignee: Allnex IP SARL (Allnex (Luxembourg) & Cy SCA)
• Inventors: Weikard, Jan, Fischer, Wolfgang, Facke, Thomas
• Granted Patent: US 8,957,176 B2
• Time in Patent Office: Days
• US Class Current: 528/44
• CPC Class Codes: C08G 18/8175 with esters of acrylic or alkylacrylic acid having only one group containing active hydrogen
• CPC Class Codes: C09D 175/16 having terminal carbon-to-carbon unsaturated bonds

Abstract

The invention provides innovative blocked polyisocyanates whose crosslinking is initiated thermally and photochemically. The polyisocyanates comprise at least one thermally reversibly blocked NCO group whose blocking agent contains at least one group which on exposure to actinic radiation reacts, with polymerization, with ethylenically unsaturated compounds. A process for preparing the polyisocyanates, and their use in binders, is also provided.

Claims

1. Polyisocyanates which

A) comprise optionally one or more than one group which on exposure to actinic radiation reacts, with polymerization, with ethylenically unsaturated compounds (radiation-curing group) and

B) comprise at least one thermally reversibly blocked NCO group whose blocking agent contains at least one group which on exposure to actinic radiation reacts, with polymerization, with ethylenically unsaturated compounds.

2. Process for preparing the polyisocyanates according to claim 1, which involves reacting with one another

A1) one or more organic polyisocyanates with

A2) optionally one or more compounds which comprise at least one isocyanate-reactive group and contain at least one group which on exposure to actinic radiation reacts, with polymerization, with ethylenically unsaturated compounds,

A3) optionally further isocyanate-reactive compounds other than the compounds of component A2), and

A4) a blocking agent component comprising at least one blocking agent that thermally reversibly blocks NCO groups and at the same time comprises at least one group which on exposure to actinic radiation reacts, with polymerization, with ethylenically unsaturated compounds,

A5) optionally in the presence of one or more catalysts and

A6) optionally solvents, reactive diluents and/or auxiliaries and additives.

3. Process for preparing polyisocyanates according to claim 2, wherein in

A1) polyisocyanates or polyisocyanate mixtures having exclusively aliphatically and/or cycloaliphatically attached isocyanate groups are used.

4. Process for preparing polyisocyanates according to claim 2, wherein in A2) acrylates, methacrylates, maleates, fumarates, maleimides, acrylamides, vinyl ethers, propenyl ethers, allyl ethers and/or compounds containing dicyclopentadienyl units are used which contain at least one isocyanate-reactive group.

5. Process for preparing polyisocyanates according to one of claim 2, wherein in A4) (meth)acryloyloxyethyl acetoacetate, (meth)acryloyloxypropyl acetoacetate and/or (meth)acryloyloxybutyl acetoacetate are used.

6. Use of polyisocyanates according to claim 1 in the preparation of paints, coatings, sizes, adhesives, printing inks and shaped articles.

7. Coating materials comprising

B1) one or more polyisocyanates according to claim 1,

B2) one or more compounds comprising at least one isocyanate-reactive group and containing optionally one or more functional groups which on exposure to actinic radiation react, with polymerization, with ethylenically unsaturated compounds,

B3) optionally compounds which carry functional groups which on exposure to actinic radiation react, with polymerization, with ethylenically unsaturated compounds and which contain neither NCO groups nor NCO-reactive groups,

B4) optionally catalysts and

B5) optionally auxiliaries and additives.

8. Substrates coated with coatings obtainable from polyisocyanates according to claim 1.