Process for the coating of electrically conducting substrates

Details Process for the coating of electrically conducting substrates Process for the coating of electrically conducting substrates

1991-11-07

1993-08-17

Niebling, John

Chemistry: electrical and wave energy

Processes and products

Electrostatic field or electrical discharge

2041817, 427488, C25D 1312

Patent

active

052365646

DESCRIPTION:

BRIEF SUMMARY
The invention relates to a process for the coating of electrically conducting substrates in which at least one cathodically depositable binder,
The cathodic electrocoating process described above is a painting process frequently used especially for priming.
Processes of the type described above are disclosed, for example, in the following patents: DE-OS 3,518,732, DE-OS 3,518,770, EP-A-4,090, EP-A-12,463, DE-PS 3,445,857, EP-A-59,895, EP-A-74,634, U.S. Pat. No. 3,984,299, EP-A-70,550 and DE-OS 2,701,002.
The object forming the basis of the present invention is to improve the process described above.
Surprisingly, this object is achieved by a process outlined in the preamble of claim 1, which employs an electrically conducting substrate coated by a coating produced by plasma polymerization.
The electrocoating baths used according to the invention may comprise in principle any cathodically depositable non-self-crosslinking or self-crosslinking resins which are suitable for the formulation of electrocoating baths. The electrocoating baths used according to the invention may also comprise mixtures of various cathodically depositable resins.
The electrocoating baths preferred, however, are those which comprise cationic amine-modified epoxy resins as the cathodically depositable resins. Both self-crosslinking and non-self-crosslinking cationic amine-modified epoxy resins are known. Non-self-crosslinking cationic amine-modified epoxy resins are preferably used.
The term `cationic amine-modified epoxy resins` is understood to mean cationic reaction products obtained by reacting
The term `polyepoxides` is understood to mean compounds containing two or more epoxide groups in the molecule.
Particularly preferred components (A) are compounds which can be prepared by reacting equivalent weight below 2,000 with monofunctionally towards epoxide groups under the given reaction conditions or a mixture of such compounds, preferably 4:1 to 1.5:1 and the reaction of the component (a) with the component (b) being carried out at 100.degree. to 190.degree. in the presence or absence of a catalyst (cf. DE-OS 3,518,770).
Other particularly preferred components (A) are compounds which can be prepared in the presence or absence of a catalyst by polyaddition, initiated by a monofunctionally reacting initiator which contains either an alcoholic OH group or a phenolic OH group or an SH group, of a diepoxide compound and/or a mixture of diepoxide compounds, in the presence or absence of at least one monoepoxide compound, to an epoxy resin in which the diepoxide compound and initiator are incorporated in a molar ratio of greater [sic] 2:1 to 10:1 (cf. DE-OS 3,518,732).
Polyepoxides which can be employed for the preparation of the particularly preferred components (A) and even used as the components (A) themselves, are polyglycidyl ethers of polyphenols prepared from polyphenols and epihalohydrins. Bisphenol A and bisphenol F, for example, are used most preferably as the polyphenols. 4,4'-Dihydroxybenzophenone, bis(4-hydroxyphenyl)-1,1-ethane, bis(4-hydroxyphenyl)-1,1-isobutane, bis(4-hydroxy-tert.-butylphenyl)-2,2-propane, bis(2-hydroxynaphthyl)methane, 1,5-dihydroxynaphthalene and phenolic novolak resins are also suitable.
Other suitable polyepoxides are polyglycidyl ethers of polyhydric alcohols, for example ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-propylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerol and bis(4-hydroxycyclohexyl)-2,2-propane.
Polyglycidyl esters of polycarboxylic acids, for example oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid and dimerized linoleic acid may also be used. Typical examples are glycidyl adipate and glycidyl phthalate.
Other suitable compounds are hydantoin epoxides, epoxidized polybutadiene and polyepoxide compounds which are obtained by epoxidization of an olefinically unsaturated aliphatic compound.
The term `modified polyepoxides` are understood to mean polyepoxides in which some of the reactive groups h

REFERENCES:
patent: 4980196 (1990-12-01), Yasuda et al.

Affiliated with

Also associated with

Rating

Process for the coating of electrically conducting substrates does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for the coating of electrically conducting substrates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the coating of electrically conducting substrates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2241442