Colloidal polyamic acid electrodeposition compositions and process for preparing said compositions
AssigneeWestinghouse Electric Corp.
InventorDavid C. Phillips
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Abstract
A conducting non-aqueous colloidal polyamic acid electrodeposition composition is made by reacting (1) 1 part polyamic acid and 29-37 parts non-aqueous, organic solvent for the acid with (2) 0.8-1.2 parts of a nitrogen containing base to form an organic salt which is added to 50-150 parts of a non-aqueous, organic non-electrolizable, non-solvent for the acid salt.
Claims13
A method of making a nonaqueous, colloidal, polyamic acid electrodeposition composition comprising the steps of:
- A. providing a salt solution comprising:
- 1 part by weight of organic aromatic polyamic acid, about 29-37 parts by weight of a non-aqueous, organic, non-electrolizable, aprotic solvent for the polyamic acid and an amount of nitrogen containing base, selected from the group consisting of tertiary amines and imidazoles effective to form an organic acid salt, and
- B. adding the salt solution to about 50-150 parts by weight of a non-aqueous, organic, non-electrolizable, non-solvent for the salt which is not capable of dissolving the acid salt, to provide a colloidal dispersion of the salt within the solvent mixture,
- the composition having a pH of between 8-10 and a solids content of between about 0.5 wt.% to about 1.5 wt.% based on polyamic acid and total solvent.
A colloidal polyamic acid electrodeposition composition comprising a colloidal dispersion of organic acid salt within a solvent mixture, said acid salt being the reaction product of 1 part by weight of organic aromatic polyamic acid and about 0.8-1.2 parts by weight of nitrogen containing base, selected from the group consisting of tertiary amines and imidazoles, and said solvent mixture comprising about 29-37 parts by weight of a non-aqueous organic, non-electrolizable, aprotic solvent for the polyamic acid and about 50-150 parts by weight of a non-aqueous, organic, non-electrolizable non-solvent for the salt which is not capable of dissolving the acid salt, the composition having a pH of between 8-10 and a solids content of between about 0.5 wt.% to about 1.5 wt.% based on polyamic acid and total solvent.
A colloidal polyamic acid electrodeposition composition comprising a colloidal dispersion of organic acid salt within a solvent mixture, said acid salt comprising 1 part by weight of organic aromatic polyamic acid and an amount of 1 methyl imidazole effective to form an organic acid salt, said solvent mixture comprising about 29-37 parts by weight of an organic solvent for the polyamic acid selected from the group consisting of dimethylsulfoxide, N-methyl-2-pyrrolidone and mixtures thereof and about 50-150 parts by weight of an organic non-solvent for the salt which is not capable of dissolving the salt selected from the group consisting of methyl ethyl ketone, acetone and mixtures thereof, wherein the pH of the composition is between 8-10, and the solids content of the composition is between about 0.5 wt.% to about 1.5 wt.% based on polyamic acid and total solvent.
Dependencies are inferred from the claim text.