Radiation-Curable Water-Emulsifiable Polyisocyanates

• US 20080300338A1
• Filed: 11/23/2006
• Published: 12/04/2008
• Est. Priority Date: 12/01/2005
• Status: Active Grant

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF SE
• Inventors: Wagner, Eva, Steinbrecher, Angelika Maria, Schwalm, Reinhold, Beck, Erich, Heischkel, Yvonne
• Granted Patent: US 7,943,682 B2
• Time in Patent Office: Days
• US Class Current: 522/107
• CPC Class Codes: C08G 18/092 oligomerisation to isocyanurate groups
• CPC Class Codes: C08G 18/283 Compounds containing ether groups, e.g. oxyalkylated monohydroxy compounds
• CPC Class Codes: C08G 18/3857 having nitrogen in addition to sulfur
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08G 18/706 the liquid medium being water
• CPC Class Codes: C08G 18/7831 containing biuret groups
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates

Abstract

The invention relates to radiation-curable, water-emulsifiable compounds containing isocyanate groups or capped isocyanate groups, and to their use.

Claims

1. A water-emulsifiable, radiation-curable polyisocyanate (A) comprising as synthesis components

a) at least one organic di- or polyisocyanate,

b) at least one compound having at least one isocyanate-reactive group and at least one free-radically polymerizable unsaturated group and/or at least one cationically polymerizable group selected from optionally substituted acryloyl groups and optionally substituted vinyl ether groups,

c) optionally, at least one further organic di- or polyisocyanate, different than a)

d) at least one compound having precisely one isocyanate-reactive group and at least one saturated dispersive group,

e) optionally, at least one compound having at least two isocyanate-reactive groups, and

f) optionally, compounds different than a) to d) and having at least one isocyanate-reactive group,

wherefrom compounds carrying capped amino groups, carbamate end groups and/or urea end groups in combination with anionic dispersive compounds are excluded as synthesis components, and

wherein the isocyanate content, calculated as NCO with the molecular weight 42 g/mol, is at least 3% by weight and up to 25% by weight.

2. The polyisocyanate according to claim 1, wherefrom compounds carrying capped amino groups, carbamate end groups and/or urea end groups in combination with anionic or cationic dispersive compounds are excluded as synthesis components.

3. The polyisocyanate according to claim 1, wherefrom compounds carrying capped amino groups, carbamate end groups and/or urea end groups are excluded as synthesis components.

4. The polyisocyanate according to claim 1, wherein the compound d) is a compound d1) which carries at least one anionic group or group which can be converted into an anionic group, or is a compound d3) which carries at least one nonionic group as dispersive group.

5. The polyisocyanate according to claim 4, wherein the compound d3) is polyalkylene oxide polyether alcohol which is obtainable by reacting at least one saturated aliphatic or cycloaliphatic alcohol with ethylene oxide, propylene oxide, isobutylene oxide, vinyloxirane and/or styrene oxide, in any order or else in a mixture.

6. The polyisocyanate according to claim 4, wherein the monohydric polyalkylene oxide polyether alcohol comprises 5 to 50 ethylene oxide units.

7. The polyisocyanate according to claim 4, wherein the compound d1) is N-cyclohexylaminoethanesulfonic acid or N-cyclohexylaminopropanesulfonic acid.

8. The polyisocyanate according to claim 1, wherein the allophanate group (calculated as C₂N₂HO₃=101 g/mol) content is at least 1.5% by weight.

9. A coating composition comprising

(A) a polyisocyanate according to claim 1,

(C) optionally, one or more photochemically and/or thermally activable initiators,

(D) optionally, further, typical coatings additives,

(E) at least one compound having more than two isocyanate-reactive groups (binder), and

(F) optionally, at least one compound having one or more than one free-radically polymerizable double bond.

10. The coating composition according to claim 9, wherein said binder (E) is selected from the group consisting of polyacrylate polyols, polyester polyols, polyether polyols, polyurethane polyols;

polyurea polyols;

polyester polyacrylate polyols;

polyester polyurethane polyols;

polyurethane polyacrylate polyols, polyurethane-modified alkyd resins;

fatty acid-modified polyester polyurethane polyols, copolymers with allyl ethers and graft polymers from the stated classes of compound.

11. A process for preparing a water-emulsifiable, radiation-curable polyisocyanate, which comprises reacting at least one diisocyanate a) in a first step with at least one compound d) under reaction conditions under which substantially formation of urethane takes place to give the diurethane, subsequently reacting the resultant diurethane in a second step with the same di- or polyisocyanate a) and/or a different di- or polyisocyanate c) under reaction conditions under which substantially formation of allophanate takes place, and then reacting the resultant allophanate-functional polyisocyanate in a third step with at least one compound b), wherein a), b), c), and d) have the same definition as in claim 1.

12. A process for preparing a water-emulsifiable, radiation-curable polyisocyanate, which comprises reacting at least one diisocyanate a) in a first step with at least one compound b) under reaction conditions under which substantially formation of urethane takes place to give the diurethane, subsequently reacting the resultant diurethane in a second step with the same di- or polyisocyanate a) and/or a different di- or polyisocyanate c) under reaction conditions under which substantially formation of allophanate takes place, and then reacting the resultant allophanate-functional polyisocyanate in a third step with at least one compound d), wherein a), b), c), and d) have the same definition as in claim 1.

13. A process for preparing a water-emulsifiable, radiation-curable polyisocyanate, which comprises reacting at least one di- or polyisocyanate a) with a mixture of at least one compound b) and at least one compound d) under reaction conditions under which substantially formation of allophanate takes place, wherein a), b), and d) have the same definition as in claim 1.

14. The process according to claim 13, wherein use is made, as compounds containing isocyanurate groups, of those based on hexamethylenediamine and having an NCO content to DIN EN ISO 11909 of 21.5%-22.5%, a viscosity at 23°

C. to DIN EN ISO 3219/A.3 of 2500-4000 mPas, and an average NCO functionality of 3.0 to 4.0.

15. The process according to claim 13, wherein use is made, as compounds containing biuret groups, of those based on hexamethylenediamine and having an NCO content to DIN EN ISO 11909 of 22%-24%, a viscosity at 23°

C. to DIN EN ISO 3219A.3 of 1500-6500 mPas, and an average NCO functionality of 3.0 to 4.0.

16. A composition for coating wood, paper, textile, leather, nonwoven, surfaces of plastics, glass, ceramic, mineral building materials or coated or uncoated metals which comprises the polyisocyanate according to claim 1.

17. A primer, surfacer, pigmented topcoat material or clearcoat in industrial coating, aircraft or large-vehicle coating, wood coating, automotive finishing, OEM finishing or refinish, or decorative coating which comprises the polyisocyanate according to claim 1.