Method of selectively hydrogenating ethylenically unsaturated double bonds in polymers

• US 6,696,518 B1
• Filed: 11/27/2001
• Issued: 02/24/2004
• Est. Priority Date: 05/27/1999
• Status: Expired due to Fees

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF AG (BASF SE)
• Inventors: Maas, Heiko, Schädler, Volker, Dersch, Rolf
• Primary Examiner(s): REDDICK, MARIE L
• Application Number:
  US09/926,625
• Time in Patent Office: 819 Days
• Field of Search: 524/571, 524/575, 524/565, 524/821, 524/836, 524/556, 524/561, 524/562, 524/449, 524/451, 524/492, 524/493, 524/494, 524/566, 524/560, 524/573, 525/329.3, 525/331.9, 526/91, 526/93, 528/487, 528/488, 528/499
• US Class Current: 524/560
• CPC Class Codes: C08C 19/02 Hydrogenation
• CPC Class Codes: C08F 8/04 Reduction, e.g. hydrogenation
• CPC Class Codes: C09D 1/04 with organic additives

Abstract

The present invention relates to a process for hydrogenating ethylenically unsaturated double bonds in polymers P by reacting an aqueous dispersion of at least one polymer P with hydrogen in the presence of at least one hydrogenation catalyst comprising at least one transition metal selected from rhodium and/or ruthenium and at least one nonionic phosphorus compound capable of forming a coordinative compound with the transition metal, which comprises incorporating the hydrogenation catalyst into the aqueous dispersion of the polymer P without adding a solvent. The present invention also relates to the aqueous dispersions of the hydrogenated polymers P obtainable by this process and to coating compositions comprising such dispersions.

Claims

1. A process for hydrogenating ethylenically unsaturated double bonds in polymers P by reacting an aqueous dispersion of at least one polymer P with hydrogen in the presence of at least one hydrogenation catalyst comprising ruthenium and at least one nonionic phosphorus compound capable of forming a coordinative compound with the ruthenium, which comprises incorporating the hydrogenation catalyst into the aqueous dispersion of the polymer P without adding a solvent.

2. A process as claimed in claim 1, wherein the hydrogenation catalyst is produced by adding at least one phosphorus compound to an aqueous dispersion of the polymer P containing the ruthenium in the form of a salt or a complex compound.

3. A process as claimed in claim 1, wherein the aqueous dispersion of the polymers P contains not more than 1000 ppm of an organic solvent.

4. A process as claimed in claim 1, wherein the phosphorus compound is selected from the group consisting of compounds of the formula I

5. A process as claimed in claim 1, wherein the aqueous dispersion of the polymers P has been prepared by free-radical aqueous emulsion polymerization of ethylenically unsaturated monomers M.

6. A process as claimed in claim 5, wherein the ruthenium in the form of a complex compound or a salt is dissolved or dispersed in the monomers M to be polymerized.

7. A process as claimed in claim 1, wherein from 1 to 1000 ppm of ruthenium are used based on the overall weight of the polymer P in the dispersion.

8. A process as claimed in claim 1, wherein the reaction is conducted at temperatures in the range from 20 to 250°

C. and under hydrogen partial pressures in the range from 0.5 to 600 bar.

9. A process as claimed in claim 1, wherein the hydrogenation is carried out to a conversion of at least 50 mol %, based on the ethylenically unsaturated double bonds present in the polymer P.

10. A process as claimed in claim 1, wherein the polymers P comprise at least one conjugated diene as monomer a and at least one monoethylenically unsaturated monomer b which is copolymerizable with the diene, and, optionally, one or more modifying monomers c.

11. An aqueous polymer dispersion obtained by a process as claimed in claim 1, comprising at least one hydrogenated polymer P′

derived from a polymer P.

12. An aqueous polymer dispersion as claimed in claim 11, wherein the polymer P comprises:

from 10 to 90% by weight of at least one monomer a selected from the group consisting of butadiene and isoprene,

from 10 to 90% by weight of at least one monomer b selected from the group consisting of vinylaromatic monomers, esters of acrylic acid with a C₁-C₁₂-alkanol, esters of methacrylic acid with a C₁-C₁₂-alkanol, acrylonitrile and methacrylonitrile,

from 0 to 20% by weight of one or more monomers c,

the fractions of the monomers a, b and c adding up to 100% by weight and the fraction of acrylonitrile and methacrylonitrile being less than 20% by weight.

13. An aqueous coating composition comprising at least one aqueous polymer dispersion as claimed in claim 11 and at least one inorganic pigment and/or an organic filler.

14. A coating composition as claimed in claim 13 whose pigment volume concentration pvc is at least 40.

15. A coating composition as claimed in claim 13 in the form of a dispersion silicate paint.