Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1983-12-27
1985-08-20
Kight, John
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
528119, 528120, 528 45, 2041817, 524904, 523415, 523417, 523418, C08G 5924, C25D 1306
Patent
active
045365580
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to the synthesis of chain extended epoxy-ester resins suitable for cationic electrodeposition. The resins are formed by first chain extending high molecular weight polyepoxides with polyfunctional acid compounds, to form epoxide functional esters which are subsequently reacted with secondary amine. The resins are made water dispersible via neutralization with an acid and crosslinked, during curing on the substrate, preferably with the aid of blocked isocyanates derivatives.
BACKGROUND ART
The coating of electroconductive substrates by electrodeposition is an important industrial process. In this process, a conductive article is immersed as one electrode in a coating composition made from an aqueous dispersion of film-forming polymer. An electric current is passed between the article and a counter electrode in electrical contact with the aqueous dispersion until a desired amount of coating is produced on the article. The article to be coated can made the anode or the cathode depending upon the ionic nature of the coating system.
Cationic coating compositions generally are derived from resinous compositions containing a basic nitrogen atom which can be neutralized with an acid and then be dissolved or dispersed in water. Sufficient basic nitrogen atoms should be present so that the dispersibility or solubility can be obtained with a minimum amount of acid. The most commonly employed type of cathodically electrode depositable resins are made by reacting a polyepoxide resin with amine at elevated temperatures, as exemplified in U.S. Pat. No. 4,137,140 to Belanger, U.S. Pat. No. 4,182,831 to Hicks, and U.S. Pat. Nos. 3,922,253 and 3,947,338 to Jerabek et al. Marchetti et al in U.S. Pat. No. 4,104,147 disclose chain-extended polyepoxide which is adducted with a secondary amine, wherein the chain-extended polyepoxide is made by reacting a high molecular weight epoxide with an organic polyol. May, in U.S. Pat. No. 3,719,626 discloses amine adducts of polyepoxides, wherein the polyepoxide includes epoxidized polyesters obtained by reacting an unsaturated polyhydric alcohol and/or an unsaturated polycarboxylic acid. Aqueous coating compositions of these resins are made by reacting the resin with a water soluble acid and subsequently dispersing the resin in water. The coating compositions are deposited on a substrate and crosslinked at elevated temperatures by means of an agent which is capable of reacting with the hydroxyl or amine functionality of the resin during curing to form a thermoset film. The crosslinking agent, which is generally a blocked isocyanate, may be incorporated into the resin molecule as is taught in the Jerabek et al patents or, as is more generally the case, the crosslinking agent may be present in the aqueous coating bath so as to codeposit with the resin.
DISCLOSURE OF THE INVENTION
The compositions of this invention are water dispersible, cathodically electrodepositible resins. These resins are characterized in that they comprise the reaction product of: (A) epoxide functional esters and (B) secondary amines, wherein the ester and the amines are reacted in amounts sufficient to react essentially all of the epoxide groups of the ester with the amides. The epoxide functional ester (A) is formed by chain extending (a) polyepoxide having (i), on average, at least 2, and preferably only 2, epoxide groups per molecule and (ii) a molecular weight of at least about 350 with (b) polycarboxylic acid bearing at least 2, and preferably only 2, carboxyl groups per molecule. The polyepoxide and polycarboxylic acid are reacted in amounts sufficient to provide between about 0.1 and about 0.8 acid groups per epoxide groups. The resin is dispersible in water with the aid of water soluble acid to provide cationic groups in the resins.
Crosslinking of the resin during curing preferably takes place by means of blocked (i.e., capped) isocyanate groups which may be incorporated into the resin molecule or, more preferably, by means of a fully blocked isocyanate which is
REFERENCES:
patent: 3640926 (1972-02-01), Slater
patent: 3719626 (1973-03-01), May
patent: 3922253 (1975-11-01), Jerabek et al.
patent: 3947338 (1976-03-01), Jerabek et al.
patent: 4093594 (1978-06-01), Anderson
patent: 4104147 (1978-08-01), Marchetti et al.
patent: 4116900 (1978-09-01), Belanger
patent: 4120768 (1978-10-01), Gibson et al.
patent: 4137140 (1979-01-01), Belanger
patent: 4139510 (1979-02-01), Anderson
patent: 4148772 (1979-04-01), Marchetti et al.
patent: 4182831 (1980-01-01), Hicks
patent: 4182833 (1980-01-01), Hicks
patent: 4212779 (1980-07-01), Schmalzer et al.
patent: 4246087 (1981-01-01), Tsov et al.
patent: 4292155 (1981-09-01), Bosso et al.
patent: 4294940 (1981-10-01), Hino et al.
patent: 4302373 (1981-11-01), Steinmetz
patent: 4396649 (1983-08-01), Bailey et al.
Draper Garnette D.
Ford Motor Company
Kight John
May Roger L.
Melotik Lorraine S.
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