DE1957426B - Method of making a heat-resistant ink - Google Patents

Description

Magnesium chloride used As a means of improving heat resistance can be clay, such as kaolin or hard clay can be used. Silicate has the property both at room temperature and at high Temperature adheres firmly to steel surfaces and forms a film when the water evaporates, which adheres firmly to the steel surface at room temperature, which is usually not the case for phosphate. If a silicate is used, sodium or calcium silicate can be used. Nonionic surfactants Agents improve the wetting ability or marking fluid, especially if the surface to be marked is wet or soiled with oil.

If glass powder is used, one can in particular Use fine powdered fourth low-melting glass, which serves as an adhesive and is permanent Adhesion of the pigment causes. When using mica powder, a mutual dissolution of the occurs Mica powder and the phosphate at temperatures between about 400 and 600 ° C and the fall of the pigment is prevented.

In addition to the materials mentioned above, polyvinyl alcohol or other water-soluble Substances to increase the viscosity are added, in particular to prevent the suspended particles from settling to prevent.

In the following examples, the quantities are given Parts by weight.

1 Examples
2 I 3 0
20th
10
10
40
10
0
0
10
2 4th Sodium pyro
phosphate
Calcium phosphate ..
Magnesium chloride
Sodium silicate
water 15th
15th
5
0
40
10
10
5
0
2 10
10
5
10
50
15th
0
0
0
2 10
10
5
10
40
15th
0
5
5
2 Titanium white
volume Mica powder
Glass powder
Non-ionic limit
area active
medium

In the marking liquids for making heat-resistant markings according to the above Examples react the sodium pyrophosphate and / or calcium phosphate with the magnesium chloride with formation of a stable complex salt. Even if these marking fluids in a very used or stored in a warm environment, the phosphate does not decompose with the formation of phosphoric acid, as is the case with the well-known heat-resistant

ίο marking fluids or paints is the case and even when stored in a metal container, none of the marking fluids present occurs Corrosion. Even if the heat-resistant marking liquid according to the invention in a automatic marking machine for marking a high-speed rolled steel sheet strip or a very hot cast block or bar, its Temperature e.g. B. 800 to 1200 ° C, with a Marking by hand would be very difficult, the automatic marking device will rust and corrode, in particular the reservoir for the marking fluid and the spray nozzle prevented and thus ensures a long service life of the marking device, which is relatively expensive in practice. The heat-resistant marking liquid according to the invention also provides clear white markings on materials at normal temperature, it provides very clear, white, enamel-like markings, when the marked material is heated up to about 500 ° C for hardening, post-annealing or rolling or when the marking liquid is applied directly to a hot surface. The markings adhere very well and do not disappear even if the marked material has cooled down quickly They are also very resistant to mechanical stress, e.g. rubbing. If on the other hand a steel plate marked with the present heat-resistant marking liquid is heated and is rolled by means of rollers, the marking does not stick to the rollers. The heat-resistant marking fluid according to the invention is therefore particularly suitable for marking cast blocks or high temperature ingots before roughing or blooming and using automatic Marking machines without the fear of corrosion of these machines.

Claims (2)

1 2 patent applications ^ em Ph ° sPnat reacts to form a non-corrosive, harmless salt complex. 1. Method for producing a heat-resistant With the heat-resistant marking liquid Digen ink for marking metal surfaces according to the invention can not only metal surfaces on the basis of an aqueous solution 5 surfaces, especially steel surfaces in normal a phosphate, heat-resistant pigments and temperatures, but also the heat-stable additives, thereby marked surfaces of ingots or ingots, the one draws that the phosphate in aqueous very high temperature, such as 800 to 1200 ° C, before Solution to be marked with a metal compound in the presence of rolling out. As the marking fluids remaining constituents for complex formation um- io liquid or ink according to the invention, heat-resistant puts. - is, it does not disappear and it does not become un- 2. Process for the production of a heat-resistant, if the marked steel products of digen ink according to claim 1, characterized by room temperature to an elevated temperature, such as draws that as a further additive silicate, clay, powder 200 to 800 ° C, for hardening, afterglow or WaI-verisiert Mica, glass powder and / or a 15 zen can be heated or of higher temperatures surfactant is used. be cooled to room temperature. For the production of the heat-resistant marking The invention relates to a method for producing liquid according to the invention are preferred Development of a heat-resistant ink for marking a pyrophosphate and / or another phosphate in Metal surfaces based on an aqueous 20 dissolved water and an oxide or chloride of an algae Solution of a phosphate, heat-resistant pigment, such as magnesium oxide, magnesium chloride, menten and heat-stable additives with the identifier calcium oxide or calcium chloride or an oxide or sign that the phosphate in aqueous solution is chloride of a metal, such as zinc and iron, with with a metal compound in the presence of the rest of the phosphate to form a complex salt Reacts components for complex formation. 25 reacts, added. The mixture is then as long as From German patent specification 346 824 one is stirred as required. If the viscosity of the solvent Method of making ink for desiccation is too large for practical purposes, using it Stone printing known, whereby ordinary stone printing ■; Diluted with water, and then a pigment is added or lithographic ink a mixture of counterparts, moreover can still be used if necessary Fat-resistant and hygroscopic (additive that improves heat resistance, a SiIi- fluid) substances are added, including, among other things, a surface-active substance, glass powder, rem dissolvable salts of phosphoric acid are used, mica powder is added and dispersed will. the, whereby one then a marking liquid A marking liquid is also obtained in ink or suspension. The percentage of the above-mentioned mate room temperature up to about 1000 ° C applied to steel surfaces at temperatures of 35 preferably lies in the following table. The well-known marking fluid belle listed areas. In this table and in or ink contains a pigment and a phosphate, the following statements are all quantities to improve the adhesion of the pigment to ben weight percent or parts by weight,
serves the steel surface. The in this marking- 40 phosDhat 20 to 70 "la
However, the phosphate contained in the liquid decomposes Heat-resistant pigment ' WWW. 5 to 4 nights »/ night
at temperatures of about 70 to 8O ⁰ C in phosphorus water 40 to 80%
acid, which is highly corrosive and iron containers, metal compound ''.'.'.'.'.'.'.'.'.'.'.'.'.'. 5 to 20%
which contain the marking liquid rust. _{Addition to the} improvement of the This is especially true when using automatic 45 heat resistance. 0 to 40% Marking devices that are very annoying when. Silicate 0 to 50% Marking of running, hot rolled steel sheets - Nonionic surfactant The ingots or ingots, which are very hot or very hot, have an average of 0 to 5 ° / o must be turned, as there is a marking of GlasDowver 0 to 30 ° / o Hand is practically no longer possible. The well-known 50 mica powders''.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. 0 to 10%
Marking fluids cause rapid corrosion of the reservoir and the spray nozzle Marking devices in general 55 very good. By cooling and solidifying, one can be used at workplaces where the permanent adhesion of the pigment to the steel surface is high. The decomposition can take effect. of the phosphate and thus the corrosion practically in one explained in more detail below not prevent. Embodiment de / invention is a calcium The invention is intended to prevent these disadvantages from using pyrophosphate. May. uses preferential and a heat-resistant ink or marking a phosphate, whose melting point is as close as possible liquid are indicated, which do not corrode good for the heat treatment of the to be marked sion caused. Stalumaierials fits. As a heat-resistant pigment According to the invention, this is achieved by using titanium white. As a metal connector that the phosphate in the form of a complex compound 65 can, as mentioned above, z. B. the different is present. Use the most oxides or chlorides if they In practice, the ions in the water and a phosphate complex salt, which serve as an adhesive, are formed. Phosphate added a metal compound that is associated with the. In the mentioned embodiment