Method for producing a pigment paste, aqueous electrocoat material, use thereof, method for cataphoretic electrocoating, and coated article

Patent metadata

Field	Value
Publication number	US-2016333197-A1
Application number	US-201315106574-A
Country	US
Kind code	A1
Filing date	Dec 20, 2013
Priority date	Dec 20, 2013
Publication date	Nov 17, 2016
Grant date	—

Abstract

The invention relates to a method for producing a pigment paste by mixing at least one pigment, consisting of solid particles, with a grind resin in the presence of water and/or an organic liquid, wherein the grind resin comprises a dispersion of core-shell particles in an epoxide prepolymer which is liquid at 20° C., or consists of such a dispersion, and the core-shell particles have a silicone core and a polymer shell.
The invention also relates to an aqueous electrocoat material, to the use thereof, to a method for cataphoretic electrocoating, and to a coated article.

First claim

1 : A method for producing a pigment paste, comprising:
mixing at least one pigment, in the form of solid particles, with a grind resin in the presence of at least one of water and an organic liquid, thereby obtaining a pigment paste wherein the grind resin comprises a dispersion of core-shell particles in an epoxide prepolymer which is liquid at 20° C., and the core-shell particles have a silicone core and a polymer shell.

2 : The method as claimed in claim 1 , further comprising:
homogenizing a pigment paste obtained from said mixing.

3 : The method as claimed in claim 2 , wherein the pigment particles, during said homogenizing, are comminuted to a preselected particle size and dispersed by introduction of mechanical energy.

4 : The method as claimed in claim 1 , wherein the polymer shell of the core-shell particles comprises at least one poly(meth)acrylate.

5 : The method as claimed in claim 1 , wherein the epoxide prepolymer has an epoxy equivalent weight in the range from 150 to 300 g/eq.

6 : The method as claimed in claim 1 , wherein the dispersion of core-shell particles is used present in an epoxide prepolymer, in an amount such that the pigment paste obtained from said mixing comprises 1 to 6 wt % of core-shell particles, based on the total amount of the grind resin.

7 : A pigment paste obtained by a method as claimed in claim 1 .

8 : An aqueous electrocoat material which comprises a cataphoretically depositable resin system and a pigment paste as claimed in claim 7 .

9 : The aqueous electrocoat material as claimed in claim 8 , wherein the resin system comprises at least one epoxide-based monomers or at least one prepolymer and at least one curing agent for epoxides.

10 : The aqueous electrocoat material as claimed in claim 8 , which is in the form of a miniemulsion.

11 : The aqueous electrocoat material as claimed in claim 8 ,
which comprises at least 30 ppm of bismuth in dissolved form, based on the total preparation, wherein calculated amount is based on the amount of bismuth metal in the aqueous electrocoat material.

12 . (canceled)

13 : A method for cataphoretic electrocoating of metal surfaces, comprising:
contacting a metal surface with an aqueous electrocoat material as claimed in claim 8 .

14 : The method as claimed in claim 13 , wherein said contacting comprises:
(1) immersing the metal surface with said aqueous electrocoat material (2) applying, for at least ten seconds, a voltage in a range of from 1 to 50 V to the immersed metal surface; and (3) applying, for at least ten seconds, a voltage in a range of from 50 to 400 V to the immersed metal surface, provided the voltage applied during said (3) applying is not less than 10 V more than the voltage applied during said (2) applying.

15 : An article, comprising:
at least in part a metal surface that has been coated by a method as claimed in claim 13 .

16 : The method according to claim 13 , wherein the metal surface is an aluminum surface.

17 : The article according to claim 15 , wherein the metal surface is an aluminum metal surface.

18 : The aqueous electrocoat material as claimed in claim 8 ,
which comprises at least 100 ppm of bismuth in dissolved form, based on the total preparation, wherein calculated amount is based on the amount of bismuth metal in the aqueous electrocoat material.

19 : The aqueous electrocoat material as claimed in claim 8 ,
which comprises at least 200 ppm of bismuth in dissolved form, based on the total preparation, wherein calculated amount is based on the amount of bismuth metal in the aqueous electrocoat material.

20 : The aqueous electrocoat material as claimed in claim 8 ,
which comprises at least 250 ppm of bismuth in dissolved form, based on the total preparation, wherein calculated amount is based on the amount of bismuth metal in the aqueous electrocoat material.

Assignees

• Basf Coatings Gmbh

Inventors

• Herrmann Ute
• Sinnwell Sebastian
• Gelbich Thorsten
• Markou Konstantinos
• Schulte Rolf
• Holtschulte Sabine
• Stoll Dominik
• Ott Guenther

Classifications

• C25D13/22

  Servicing or operating {apparatus or multistep processes} · CPC title

• C09D5/4473

  Mixture of polymers · CPC title

• C09C1/3623

  Grinding · CPC title

• C25D13/18

  using modulated, pulsed, or reversing current · CPC title

• C09D5/02

  Emulsion paints {including aerosols} · CPC title