Electrodeposition liquid and electrodeposition-coated article

Patent metadata

Field	Value
Publication number	US-11230788-B2
Application number	US-201716077686-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	Feb 18, 2016
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

Provided is an electrodeposition dispersion including a polyamide-imide resin, a polar solvent, water, a poor solvent, and a base, in which the polar solvent is an organic solvent having a boiling point of higher than 100° C. and D (S-P) represented by a formula (1) satisfying a relationship of D (S-P) <6, and a weight-average molecular weight of the polyamide-imide is 10×10 4 to 30×10 4 or a number-average molecular weight of the polyamide-imide is 2×10 4 to 5×10 4 .

D (S-P) =[( dD S −dD P ) 2 +( dP S −dP P ) 2 +( dH S −dH P ) 2 ] 1/2   (1)

First claim

The invention claimed is:

1. An electrodeposition dispersion comprising:
a polyamide-imide resin;
a polar solvent;
water;
a poor solvent having a solubility of polyamide-imides of 1 g/100 g-the solvent or less; and
a base,
wherein the polar solvent is an organic solvent having a boiling point of higher than 100° C. and D (S-P) represented by a formula (1) satisfying a relationship of D (S-P) <6, where D (S-P) represents a Hansen solubility parameter value (HSP value),
a weight-average molecular weight of the polyamide-imide resin is 10×10 4 to 30×10 4 or a number-average molecular weight of the polyamide-imide resin is 2×10 4 to 5×10 4 ,
an average size of the polyamide-imide resin particles is 400 nm or less,
D (S-P) =[( dD S −dD P ) 2 +( dP S −dP P ) 2 +( dH S −dH P ) 2 ] 1/2   (1)

where dD S represents a dispersion term of an HSP value of the polar solvent, dD P represents a dispersion term of an HSP value of the polyamide-imide resin, dP S represents a polarity term of the HSP value of the polar solvent, dP P represents a polarity term of the HSP value of the polyamide-imide resin, dH S represents a hydrogen bonding term of the HSP value of the polar solvent, and dH P represents a hydrogen bonding term of the HSP value of the polyamide-imide resin,
the poor solvent is selected from the group consisting of isopropyl alcohol, 1-methoxy-2-propanol and cyclohexanone, and
the average size of the polyamide-imide resin particles is in a range of 130 to 290 nm.

2. The electrodeposition dispersion according to claim 1 ,
wherein the polar solvent satisfies the relationship of D (S-P) <6 under a presumption that:
a polyamide-imide-soluble polar solvent is defined as a polar solvent capable of dissolving polyamide-imide particles to form a transparent mixture;
a polyamide-imide-insoluble polar solvent is defined as a polar solvent incapable of dissolving polyamide-imide particles to form a white turbid mixture; and
in a three-dimensional graph where dD S s, dP S s, and dH S s are plotted, a center of a minimum sphere including all of points represented by the polyamide-imide-soluble polar solvent therein is defined as the dD P , dP P , and dH P .

3. The electrodeposition dispersion according to claim 1 ,
wherein the polar solvent is a hydrophilic solvent.

4. The electrodeposition dispersion according to claim 1 ,
wherein the polar solvent is N,N-dimethylacetamide, N,N-dimethylformamide, propylene carbonate, dimethyl sulfoxide, 4-butyrolactone, N-methyl-2-pyrrolidone, or 1,3-dimethyl-2-imidazolidinone.

5. The electrodeposition dispersion according to claim 1 , wherein the base is selected from the group consisting of N,N-dimethylaminoethanol, tripropylamine and triethanolamine.

6. An electrodeposition-coated body comprising:
a body to be coated; and
an insulating film which is formed on a surface of the body to be coated while using the electrodeposition dispersion according to claim 1 ,
wherein, in the insulating film formed on the surface of the body to be coated, the number of pinholes is 50 pinholes/10 μm 2 or less, a surface roughness Ra is 50 nm or less,
the body to be coated is a conductive wire with a rectangular cross section, and
a difference between a thickness of the insulating film on a flat surface part of the conductive wire and a thickness of the insulating film on a corner part of the conductive wire is 5 μm or less.

Assignees

• Mitsubishi Materials Corp

Inventors

• Hirano Koji
• Iida Shintaro
• HIRATA Jyunko
• Sakurai Hideaki

Classifications

• C08G73/1035 Primary

  from tetracarboxylic acids or derivatives and diisocyanates · CPC title

• H01B13/16

  by passing through or dipping in a liquid bath; by spraying · CPC title

• C09D7/45

  Anti-settling agents · CPC title

• H01B7/02

  Disposition of insulation · CPC title

• C09D5/4461 Primary

  Polyamides; Polyimides · CPC title