DE1571109A1 - Painting method - Google Patents

Description

POSTER PAINTS IIMITED, Argall Avenue, Leyton, London, E 10, England - ■ -. .

Painting method The invention relates to an anetrial method,

-Special on an electrophoretisolaeB anatriohTerfalirtn, "bti the Blektrophoreea for the application of organic deodorant paints is used.

Electrophoretic onion processes are already known and are examples in the "ata" Electrophoretic Fainting, Processes Applied to the Motor Industry ", published in the April issue of the Metal! Finishing Journal's has been. The known procedure essentially consists of that a metallic body that is provided with an oversug should be, in a bath of a diaperable in water

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Synthetic resin and a dye immersed in an aqueous medium will o The body to be coated will in general made the anode, while the cathode consists of the container · DC voltages of the order of 20 to 150 volts are applied for an appropriate current density is obtained. The specific current density depends in part on the thickness of the coating film desired. Completion of the film, which consists essentially of the synthetic resin in the dye, is indicated by the fact that the Current drops to a practically constant value · In another method of applying a coating With the help of ink electrophoresis painting process vtrwtndet paa, increasing tensions, in such a way that a practically constant current density is achieved. Di · Completion of the film is indicated by the fact that no further change in current bti the increase in the applied Tension is to be noticed.

Because the electrophoretic painting process has many advantages one can assume that this painting process in the future it will become more important · one difficulty however, it was found when the proceedings came up Metal body is to be used »It has been found that in this case in the surface layer the

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Coloring metal ions are present · Painting process that uses have been applied by electrophoretic processes, are generally, for example, by heating up Temperatures from about 130 to 160 ° C for 30 minutes or more thermoset. Metal atoms present in the colored coating cause discoloration of the colored coating. Therefore could so far electrophoretically ^ painting processes that 'on Metal bodies have been applied, not satisfactorily with Pastel colors can be done. Such discoloration let especially be uncomfortable when the one with a coat of paint body to be inflicted contains iron.

Previously, it was also nioht possible to apply the elektrophoretisoh · Anstriohverfahren to body m & s Injßstaföff "s or" us that no conductive surface

According to the present invention, an electrophoretic Painting process described in which a primer coat is applied to the object provided with a coating is applied in such a way that calibrate a conductive layer is on the object, and that thereafter Another part of the process is applied with the aid of electrophoretic deposition

Does the * \ 3 covering · body have a conductive * AuÄenechiolit, The primer layer is then made more antrophoretic with the aid of an aid further deposited. Has the eu overturned

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Body, however, a surface made of plastic or glass or another material that does not have adequate conductivity, then the primer layer can with the help other suitable means, for example by spraying, can be applied.

The primer coat must necessarily be conductive Be layer, so that then an electrophoretically ^ Deposition of the paint can be achieved «The primer layer is preferably a paint that can be diluted with water used, which consists of a dye and a water-dispersible synthetic resin, which when applied on the body serves as a binder for the dye «In order for the layer to be sufficiently conductive, the dye must a sufficient amount of a conductive material, for example Contains carbon black pigments such as lamp black. If desired, the pigment can also contain dispersed metal.

Ali water dispersible resin is preferred • in heat-hardenable synthetic resin, for example of the phenol-alkyd- or melamine alkyd type is used. These synthetic resins ■ charged thermosetting. Items with a color from such which are hardenable and coated with synthetic resins preferably before applying the next coat of paint

BATH

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thermoset. The water-thinnable color can be easily by dispersing the dyes in the water dispersible Form synthetic resin. The color can also be other Additions included to improve the properties of the paint to vary ”, for example it can contain organic materials that facilitate a solution, for example Isopropyl alcohol. Such connections are generally in the synthetic resins as sold by the synthetic resin manufacturers be, before. . ■ '■ -.-

The paint, which can be diluted with water and which is preferably used for the primer, contains 5 or 10 to 20 percent by weight of synthetic resin. Carbon pigments are preferably 1/8 to 1/2 kilo, preferably "1/4 kilo per + 1 pound" (1/4 bid. Pound, preferred "inta 1/2 daily pound per gallon). AXIgtxeins are usually used as 1.25 and 7 parts by weight of synthetic resin per part by weight of Jarbetoff and a ratio of about 3 s 1 is preferred.

After the Grunditreohloht was applied, came the further color coating with the help of electrophoretic deposition can be applied · It can be applied with any Paint paint can be carried out for one use "*!» · Is suitable for an electrophoretic painting process. It should be pointed out, however, that if this coating does not contain any susetania that make it conductive, no further coating with the aid of an electrophorotic one Method can be applied more to the object

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can. Jedooh can do this · Deckanstriohe with colors become «the floodplain numerous dyes including Pastel colors or white figured fabrics. To the closer Explanation of the invention is an implementation example of the inventive method described.

example

An iron article was primed by immersing it in a bath of water-dilutable paint. Here, the article was the anode and the bath served as the cathode. The water-thinnable paint consisted of a phenol alkyd water-soluble synthetic resin, which is sold under the trade name "RESYDORL P 411" · This lunethar «had a solid content of clay € 7 £ · for the present use the luBsthar * was veritia & t with water, and »was 3 feile water su 1 feil des waeetrlösliohem Kmnstharses, The paint also contained a luipigaemt, that · is sold under the trade name" MA (JI-00IiI 888 "by the Columbian Oarbon Company · The portion consisted in buckets 1/4 kilo paint per 4 1 coat of paint {Λ / 2 single pounds of paint pre gallon).

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The örundierung was done with the help of a constant DC voltage applied by about 50 yoIt. The voltage was then turned off after being the Überaugafilm Had reached a maximum, which was indicated by a drop in the flow height to a low value. During the

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Deposition of the paint was the paint mesh anisoh stirred through

The object was then removed from the bath and Washed with water until all paint is removable had been removed · The item had an adherent appearance Resin film with penance pigments. You primer coat Although it had a wet surface due to the detergent used, there was no water inside the coating layer before. The primer was then heat set by heating the body to a temperature of about 160 ° C for 30 minutes. The metal atoms lying in the primer layer became immobile during the hardening process made and could therefore ti «color one adjoining applied coating layer not

The fired object was then immersed in another bath and a normal coat of paint with the aid of an electrophoresis Procedure applied. This more color dribble consisted of a fastel color and contained a similar one Phenol alkyd synthetic resin with a suitable dye «Anaehlieiemd the item was thermoset to make the desired sohtea Seikanstrioh su received.

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Sti erfiBAumeegMiSe TerfÄhren is Jeiooh not on the im the above-mentioned example

limited. For example, the body can be made of plastic ■■ -. ". 009852/1699

* The primer layer is then sprayed on a paint that can be diluted with water and serves as a conductive layer. However, this must be done be that the water-thinnable paint must contain sufficient conductive pigments to be in the surface have the necessary conductivity. In addition, this paint must have sufficient binder to hold the film to give the appropriate strength. Multiple coats of primer can be applied if desired, provided that that each primer layer is itself a conductive one Layer represents. The ones used for the primer coat Paints can use relatively small amounts of thinners, for example barium sulfate (Blanc Fixe) and also anti-corrosion paint substances, for example strontium chromate or red sisenoxide contain. It can also contain small amounts of white pigments.

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Claims (8)

Patent claims: 1. Electrophoretic coating process, characterized in that that the object to be provided with a coating is provided with a primer layer and thereafter the actual coating is applied with the aid of electrophoretic deposition. . 2. The method according to claim 1, characterized in that the. The object to be coated has a conductive surface and the primer layer is electroproretishered Devices is attached 3. The method according to claim 1 or 2, characterized in that that the material used for the primer one with It contains thinnable paint that contains sufficient conductive pigment to remove the primer to be conductive and that this material also contains a water-dispersible synthetic resin which acts as a binder for the pigment after it has been deposited on the body 4 »Procedure, according to claim 3, because it is known that as conductive pigment carbon is used 5 «Method according to claim 3, daduroh kennseiehnct that the carbon eats soot ». _n 009852/169-Θ ^BAD - ίο - 6. The method according to any one of claims 3 to 5, characterized in that that all synthetic resin dispersible in water a synthetic resin from the group of phenol-alkyd and melamine Alkyd resin is used 7. Method according to one of Claims 3 to 6, characterized in that that the water-thinnable paint is 5 to 20 percent by weight water-dispersible synthetic resin having. 8. The method according to any one of claims 3 to 7, characterized in that that the paint that can be thinned with water contains 2.5 to 10 percent by weight of the conductive pigment. 9. Method according to one of Claims 3 to 8, characterized in that that the oewithtsr ratio of that in water dispersible plastic to the whole dye in the paint that can be thinned with water between 1.25: 1 and 7 s 1 is BAD ORIGINAL Ü09852 / 1699