DE1962100B2 - Process for producing phosphate coatings - Google Patents
Process for producing phosphate coatingsInfo
- Publication number
- DE1962100B2 DE1962100B2 DE19691962100 DE1962100A DE1962100B2 DE 1962100 B2 DE1962100 B2 DE 1962100B2 DE 19691962100 DE19691962100 DE 19691962100 DE 1962100 A DE1962100 A DE 1962100A DE 1962100 B2 DE1962100 B2 DE 1962100B2
- Authority
- DE
- Germany
- Prior art keywords
- phosphate
- metaphosphate
- alkali
- coatings
- phosphates
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
- C23C22/23—Condensed phosphates
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
- C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Soft Magnetic Materials (AREA)
- Chemical Treatment Of Metals (AREA)
Description
sungen erhalten, die sich leichter als gleichmäßige Schicht auftragen lassen. Polymeres Kaliummetaphosphat (KPOa)2; mit χ = 400 bis 20 000, auch Kaliumpolyphosphat genannt, quillt in wäßrigen Lösungen auf und hydrolysiert langsam. Als sehr brauchbar erwiesen sich wäßrige Lösungen, bzw. Suspensionen aus Gemischen von Kaliumpolyphosphat und Natriumdihydrogenphosphat im Gewichtsverhältnis von etwa 1: 2 bis 1: 2,5 und einem Feststoffgehalt von etwa 30 bis 40 Gewichtsprozent.Get solutions that are easier to apply as an even layer. Polymeric Potassium Metaphosphate (KPOa) 2 ; with χ = 400 to 20,000, also called potassium polyphosphate, swells in aqueous solutions and hydrolyzes slowly. Aqueous solutions or suspensions of mixtures of potassium polyphosphate and sodium dihydrogen phosphate in a weight ratio of about 1: 2 to 1: 2.5 and a solids content of about 30 to 40 percent by weight have proven to be very useful.
Feinpulvrige anorganische Feststoffe, die unter den Bedingungen des Glühens mit den primären Alkaliphosphaten nicht reagieren, wie z. B. Glimmer oder Pigmente, lassen sich in Mengen bis zu 30 Gewichtsprozent, vorzugsweise etwa 3 bis 10 Gewichtsprozent, bezogen auf das Phosphat, einarbeiten und erhöhen die Schichtstärke.Fine powdery inorganic solids which under the conditions of annealing with the primary alkali phosphates do not respond, such as B. mica or pigments can be used in amounts of up to 30 percent by weight, preferably about 3 to 10 percent by weight, based on the phosphate, incorporate and increase the layer thickness.
Der Auftrag der Lösungen auf die zu behandelnden Gegenstands aus Eisen oder Stahl kann auf jede bekannte Weise z. B. durch Tauch- und Spritzverfahren, oder durch Auftragen mit Gummiwalzen erfolgen. Die mit dem flüssigen Überzug versehenen Gegenstände werden dann nach einer Trocknung oder gegebenenfalls auch direkt in den Glühofen eingefahren, wenn die auftretende Wasserdampfbelastung vertretbar ist.The application of the solutions to the iron or steel object to be treated can be carried out in any known manner, e.g. B. by dipping and spraying, or by applying with rubber rollers. The objects provided with the liquid coating are then moved into the annealing furnace after drying or, if necessary, also directly, if the water vapor load that occurs is acceptable.
Es ist ferner möglich, die Überzugsmittel gemäß der Erfindung als feines Pulver unmittelbar vor dem Glühprozeß aufzutragen. Durch das Aufschmelzen im Kristallwasser und die in der Schmelze verlaufenden Kondensationsrcaktionen lassen sich auch auf diese Weise zusammenhängende Schutzschichten erhalten.It is also possible to use the coating agent according to the invention as a fine powder immediately before the annealing process to apply. Through the melting in the crystal water and the running in the melt Condensation reactions can also be obtained in this way, cohesive protective layers.
Die Ausbildung der erfhidungsgemäßen Alkalimetaphosphatschichten geschieht durch das Erhitzen auf 700 bis 10000C. Da die aufgetragenen Phosphatschichten sehr dünn sind, genügen für die gewünschte Metaphosphatbildung bereits wenige Minuten. Daher erfolgt die notwendige Temperaturbehandlung vorzugsweise bei dem insbesondere für Bleche und Drähte üblichen Glühen. Dabei vollzieht sich in dem aufgetragenen Überzugsmittel eine Kondensationsreaktion unter Ausbildung von höher polymeren Alkalimetaphosphaten, bzw. Alkalipolyphosphaten, vermutlich von der Art der Grahamschen- oder Kurrolschen Salze. Dieser Vorgang kann am Beispiel des primären Natriumphosphats wie folgt dargestellt werden:The training of erfhidungsgemäßen Alkalimetaphosphatschichten done by heating to 700 to 1000 0 C. Since the applied phosphate layers are very thin, it takes just a few minutes for the desired Metaphosphatbildung. The necessary temperature treatment is therefore preferably carried out in the annealing process which is customary in particular for sheet metal and wires. A condensation reaction takes place in the applied coating agent with the formation of higher polymer alkali metaphosphates or alkali polyphosphates, presumably of the type of Graham's or Kurrol's salts. This process can be illustrated using the example of primary sodium phosphate as follows:
XNaH2PO4 · H2O ^- XNaH2PO4 -* X^Na2H2P2O7 XNaH 2 PO 4 · H 2 O ^ - XNaH 2 PO 4 - * X ^ Na 2 H 2 P 2 O 7
-> (NaPO3)* -> (NaPO 3 ) *
Diese kondensierten Phosphate schließen bei ihrer Bildung in der Schmelze auch die gegebenenfalls zugesetzten Metaphosphate ein. Wegen ihrer Bildung aus der Schmelze sind sie innig mit der Metalloberfläche verbunden und fest haftend. Die Schichtdicken betragen bis zu 25 μ, vorzugsweise 1 bis 8 μ. Die gewünschte Schichtdicke kann durch entsprechend gewählte Mengen und Konzentrationen des Überzugsmittels leicht eingestellt werden.When they are formed in the melt, these condensed phosphates also include any added metaphosphates. Because they are formed from the melt, they are intimate with the metal surface connected and firmly adhering. The layer thicknesses are up to 25 μ, preferably 1 to 8 μ. the The desired layer thickness can be determined by appropriately selected amounts and concentrations of the coating agent can be easily adjusted.
Der elektrische Widerstand der erfindungsgemäßen Schutzschichten beträgt je nach Schichtdicke zwischen 5 und 1000 Ohm · cm-2 und entspricht damit den Werten vergleichbarer organischer Lackierungen. Die erfindungsgemäßen Schutzschichten sind zugleich eine sehr brauchbare Grundierung für Lackierungen und gute Schmiermittelträger bei anschließender Verformung. Sie bieten insbesondere die Möglichkeit, Draht ohne besondere Oberflächenbehandlung direkt zu ziehen. Auf Grund ihrer ßildungsreaktion lassen die Alkalimetaphosphatschichten auch weitere Glühungen zu und vermeiden die Bildung von blättrigem Zunder. Die in der Schlußglühe erfolgende Entkohlung wird nicht behindert.The electrical resistance of the protective layers according to the invention is between 5 and 1000 ohm · cm- 2 , depending on the layer thickness, and thus corresponds to the values of comparable organic coatings. The protective layers according to the invention are at the same time a very useful primer for paintwork and good lubricant carriers for subsequent deformation. In particular, they offer the possibility of drawing wire directly without any special surface treatment. Due to their formation reaction, the alkali metaphosphate layers also allow further annealing and avoid the formation of flaky scale. The decarburization that takes place in the final annealing is not hindered.
Beispiel
Ein Gemisch vonexample
A mixture of
15 g Mononatriumdihydrogenphosphat,
5 g handelsüblichen Kaliummetaphosphat und 20 g Monokaliumdihydrogenphosphat in
100 g Wasser15 g monosodium dihydrogen phosphate,
5 g of commercial potassium metaphosphate and 20 g of monopotassium dihydrogen phosphate in
100 g of water
ergibt eine klare viskose Lösung. Diese wird mit Gummiwalzen als 5 μ starker Film auf Elektroblech aufgetragen, kurz angetrocknet und dann in den Glühofen eingefahren, in dem das Blech etwa 3 Minuten auf 75O0C erhitzt wird. Das austretende Band ist gleichförmig mit der Schutzschicht überzogen und ao bedarf insofern keiner Nachbehandlung. Der elektrische Widerstand beträgt auf zunderfreien Oberflächen mit Mikrorauhigkeiten um 3 μ bei einer durchschnittlichen Schichtstärke vongives a clear viscous solution. This is coated with rubber rollers as a 5 μ thick film of electrical steel sheet, briefly dried, and then retracted into the annealing furnace in which the sheet is heated for about 3 minutes at 75O 0 C. The emerging tape is uniformly coated with the protective layer and therefore does not require any post-treatment. The electrical resistance on non-scaling surfaces with micro-roughness is around 3 μ with an average layer thickness of
3 μ etwa 10 Ohm · cm~2
a5 5 μ etwa 50 Ohm · cm~2
7 μ etwa 300 Ohm · cm"2
9 μ etwa 9 · 103 Ohm · cm'2 3 μ about 10 ohm cm ~ 2
a5 5 μ about 50 ohm cm ~ 2
7 µ about 300 ohm · cm " 2
9 μ about 9 · 10 3 ohm · cm ' 2
gemessen nach DIN Entwurf zwischen zwei Elektroden von 5 cm2, einem Druck/? von 10 kp/cm2 und einer Gleichspannung von 100 mV.measured according to DIN draft between two electrodes of 5 cm 2 , a pressure /? of 10 kp / cm 2 and a DC voltage of 100 mV.
VergleichsversuchComparative experiment
Die erfindungsgemäß hergestellten Isolierungen sind nicht nur temperatur- sondern auch hydrolysebeständig. Dagegen werden aus Natriumphosphaten gebildete Natriummetaphosphatschichten im Laufe der Zeit an der Luft wieder hydrolysiert, wodurch sowohl die elektrische Isolierung als auch der Kor-The insulations produced according to the invention are not only temperature-resistant but also hydrolysis-resistant. In contrast, sodium metaphosphate layers formed from sodium phosphates become in the course of the process hydrolyzed again after exposure to air, whereby both the electrical insulation and the cor-
♦o rosionsschutz vernichtet werden. Das wird an Hand des nachfolgend beschriebenen Vergleichsversuchs deutlich.♦ o rosion protection are destroyed. That will be on hand of the comparative experiment described below.
Nach der in dem vorstehenden Beispiel beschriebenen Verfahrensweise wurden Elektrobleche mit einer Mischung aus Mononatriumdihydrogenphosphat, Kaliumiretaphosphat und Monokaliumdihydrogenphosphat in Wasst: 'A) beschichtet, kurz angetrocknet und dann im GH'lioi'en 1 Minute lang geglüht. Auf weitere Bleche v-u: ^r entsprechend der US-PS 3 278 328 Mischungen hi^ primärem und sekundärem Natriumphosphat (,iJ; ulgetragen und in der genannten Weise behandelt. Die Filmstärke der viskosen Lösung war in allen Versuchen gleich. Die erhaltenen Schutzschichten besaßen nach Bewittern an der Luft unter einem Dach folgenden elektrischen Widerstand:According to the procedure described in the above example, electrical steel sheets were coated with a mixture of monosodium dihydrogen phosphate, potassium tetaphosphate and monopotassium dihydrogen phosphate in Wasst: A), dried briefly and then annealed in the GH'lioi'en for 1 minute. Vu to other plates: ^ r corresponding to US-PS 3,278,328 mixtures hi ^ primary and secondary sodium phosphate (ij; ulgetragen and treated in the above manner, the film thickness of the viscous solution was similar in all trials is equal to the protective coatings obtained had to.. Weathering in the air under a roof has the following electrical resistance:
Claims (4)
zwischen 700 und 10000C erhitzt Der Erfindung liegt die Aufgabe zugrunde, ein Ver-Formation of high-polymer alkali metaphosphates Creation of iso layers on sheet metal or heated, characterized in that dassio dem. These are wetted with a film of a Phosphaman for the production of tierungslösung in the atmosphere, the em phosphate, whose with hydrolysis-resistant coatings brings a solution on the phosphoric acid connected residue at elevated, which a mixture of to metaphosphate temperature decomposes or evaporates, and free Contains phosphoric acid condensable sodium and potassium phosphates. No metaphosphates are formed when these materials are burned in and the object is heated to temperatures
heated between 700 and 1000 0 C. The invention is based on the object of providing a
hochpolymerer Alkalimetaphosphate erhitzt. Das erfindungsgemäße Verfahren wird nicht be-of phosphate coatings on objects made of iron 35, preferably in addition to the metaphosphate condensable and iron alloys, in which a solution is used sodium and potassium phosphates, a small amount of alkali condensable to metaphosphate contains an alkali metaphosphate, in particular caphosphate, and the object to form lium metaphosphate.
high polymer alkali metaphosphates heated. The method according to the invention is not
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19691962100 DE1962100C3 (en) | 1969-12-11 | Process for producing phosphate coatings |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19691962100 DE1962100C3 (en) | 1969-12-11 | Process for producing phosphate coatings |
Publications (3)
Publication Number | Publication Date |
---|---|
DE1962100A1 DE1962100A1 (en) | 1971-06-16 |
DE1962100B2 true DE1962100B2 (en) | 1974-12-19 |
DE1962100C3 DE1962100C3 (en) | 1976-02-12 |
Family
ID=
Also Published As
Publication number | Publication date |
---|---|
DE1962100A1 (en) | 1971-06-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE69523608T2 (en) | METHOD AND COMPOSITION FOR TREATING METALS | |
DE69408996T2 (en) | COMPOSITION AND METHOD FOR TREATING METALS | |
EP0015020B2 (en) | Process for the surface treatment of metals and its use for the treatment of aluminium surfaces | |
DE3206297C2 (en) | Method of insulating hot metal objects | |
DE2743859C3 (en) | Process for the treatment of an object made of silicon-containing steel and provided with an insulating protective covering made of silicate | |
DE3933976C2 (en) | A method of forming a ceramic coating on a substrate | |
EP0155742B1 (en) | Process and coating composition for metallic surface treatment | |
DE974713C (en) | Process for the production of coatings on metals | |
DE2160784C3 (en) | Process for the production of protective layers on objects made of metals by applying polyphosphates | |
DE1962100C3 (en) | Process for producing phosphate coatings | |
DE1962100B2 (en) | Process for producing phosphate coatings | |
US3214302A (en) | Method for forming insulating coatings on metal surfaces | |
CH693233A5 (en) | Method for elektrochemischenPhosphatieren of metal surfaces, in particular of stainless steel free, and use of a water-containing phosphated Lösungfür such a procedure. | |
DE10028111A1 (en) | Inorganic film-forming coating composition, manufacturing method therefor and method of forming an inorganic film | |
DE3403660C2 (en) | Means for the production of protective layers | |
DE2911699A1 (en) | PROCESS OF MAKING THE SURFACE OF AN OBJECTIVE REMAINABLE WATER, AND ALUMINUM OBJECTS WITH A SURFACE MADE REMAINABLE TO WATER WITH WATER | |
DE2907093A1 (en) | AGENT AND METHOD FOR PRODUCING NON-METAL COATINGS ON IRON AND STEEL | |
EP0038097B1 (en) | Method for the application of insulating layers to a sheet or strip of steel or iron | |
DE2424382A1 (en) | PROCESS FOR THE PREPARATION OF METALLIC WORKPIECES FOR CHIPLESS COLD FORMING | |
DE2253455A1 (en) | COATS FOR SUBSTRATES MADE OF IRON MATERIALS | |
DE980071C (en) | Solution and process for the production of heat-resistant phosphate layers for electrical insulation on iron and steel, in particular for the insulation of magnetic sheets | |
DE1644744C3 (en) | Process for the production of an electrically insulating coating on an electrical steel sheet | |
EP3693496A1 (en) | Aqueous composition for coating grain-oriented steel | |
DE1621533C (en) | Process for the production of a glass-like coating with high electrical insulation and high heat resistance on a Sihciumstahlblech | |
DE974196C (en) | Process for the production of smooth phosphate coatings on metallic objects |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C3 | Grant after two publication steps (3rd publication) | ||
E77 | Valid patent as to the heymanns-index 1977 |