Radiation-curable aqueous polyurethane dispersions

• US 8,048,937 B2
• Filed: 02/23/2006
• Issued: 11/01/2011
• Est. Priority Date: 02/24/2005
• Status: Active Grant

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF AG (BASF SE)
• Inventors: Krueger, Christian, Lebkuecher, Werner, Larbig, Harald, Schwalm, Reinhold, Heischkel, Yvonne, Kluge, Michael, Gruber, Nick, Dieleman, Cedric
• Primary Examiner(s): Eashoo; Mark
• Assistant Examiner(s): PAUL, JESSICA MARIE
• Application Number:
  US11/816,120
• Publication Number:
  US 20080145563A1
• Time in Patent Office: 2,077 Days
• Field of Search: 427/487, 522/84, 522/90
• US Class Current: 522/84
• CPC Class Codes: C08G 18/0823 containing carboxylate salt groups or groups forming them
• CPC Class Codes: C08G 18/4277 Caprolactone and/or substituted caprolactone
• CPC Class Codes: C08G 18/6659 with compounds of group C08G18/34
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08G 18/725 Combination of polyisocyanates of C08G18/78 with other polyisocyanates
• CPC Class Codes: C08G 18/755 and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• CPC Class Codes: C08G 18/7837 containing allophanate groups
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• CPC Class Codes: C09D 175/16 having terminal carbon-to-carbon unsaturated bonds
• CPC Class Codes: C14C 11/006 using polymeric products of isocyanates (or isothiocyanates) with compounds having active hydrogen

Abstract

The present invention relates to UV-curable polyurethane dispersions, to a process for preparing them, and to their use.

Claims

1. A radiation-curable aqueous polyurethane dispersion synthesized from

a) at least one compound having at least two free isocyanate groups, at least one allophanate group, and at least one free-radically polymerizable C═

C double bond attached via the allophanate group, which is attached directly to the double bond a carbonyl group or an oxygen atom in ether function,

b) at least one compound having at least one group that is reactive toward isocyanate groups, and at least one free-radically polymerizable C═

C double bond,

c1) optionally, at least one compound with a molecular weight of not more than 500 g/mol

c2) at least one compound which has a molecular weight of more than 500 g/mol having at least two groups that are reactive toward isocyanate groups, selected from hydroxyl, mercapto, and primary and/or secondary amino groups,

c) at least one compound having at least one group that is reactive toward isocyanate groups, and at least one acid group,

d) at least one basic compound for at least partial neutralization of the acid groups of compounds c),

e) optionally, at least one compound different from b), c), and d), containing only one group that is reactive toward isocyanate groups,

f) optionally, at least one polyisocyanate different from a),

g) in the absence of a thermal initiator,

h) optionally, further additives, selected from reactive diluents, photoinitiators, and customary coatings additives,

k) water, and

l) optionally, at least one diamine and/or polyamine;

wherein component c) is present in an amount providing from 16.1 mol% to 45.1 mol% of the at least one group reactive with isocyanate relative to total mols of isocyanate present.

2. The polyurethane dispersion according to claim 1, wherein component c2) is a polyesterol based on aliphatic, cycloaliphatic and/or aromatic dicarboxylic, tricarboxylic and/or polycarboxylic acids with diols, triols and/or polyols.

3. The polyurethane dispersion according to claim 1, wherein component c2) is a lactone-based polyesterol.

4. The polyurethane dispersion according to claim 1, wherein the reaction product of synthesis components a), b), c1), c2), c) and, if appropriate, e) and f) has a double bond density of at least 1.4 mol/kg.

5. The polyurethane dispersion according to claim 1, wherein component a) comprises at least one synthesis component selected from the group consisting of hexamethylene 1,6-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, tetramethylxylylene diisocyanate and di(isocyanatocyclohexyl)methane.

6. The polyurethane dispersion according to claim 1, wherein component a) comprises at least one synthesis component selected from the group consisting of 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 1,4-butanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, glyceryl mono- and di(meth)acrylate, trimethylolpropane mono- and di(meth)acrylate, and pentaerythrityl di- and tri(meth)acrylate.

7. The polyurethane dispersion according to claim 1, wherein component c) is selected from the group consisting of dimethylolpropionic acid and dimethylolbutyric acid.

8. A substrate coated with a polyurethane dispersion according to claim 1.

9. A method of coating a substrate, which comprises applying a polyurethane dispersion according to claim 1 to a substrate, followed by drying and radiation curing.