DE1957426A1 - Heat-resistant ink - Google Patents

Description

may not be changed

Oil46-o9 / Dr.v.b / Bru

Japanese Pat.-Ania.SUO
before November 15th, 1968

Ä3ai Yushi Kogyo Kabushiki Kaisha 16, Uiiiegaka-cho 2-chome, Magata-ku »Kobe (Japan)

Heat-resistant ink

The present invention relates to a heat resistant one Ink for marking metal surfaces, especially an ink for making markings on steel surfaces at high temperatures.

The term "ink" is intended here to mean a writing fluid or a marking material that contains at least pigments and a substance for connecting these pigments to the surface to be marked, as well as a liquid in which these materials are dispersed or possibly dissolved. The ink may also contain a dye and other additives, which will be discussed below. Γ, _f -.

A marking liquid is already known which can be applied to steel surfaces at temperatures from room temperature up to about 1000 ^° C. The known marking liquid or ink contains a pigment and a phosphate, which dieöt to improve the adhesion of the pigment to the steel surface. However, the phosphate contained in the marking fluid zersetmt at temperatures of about 70 to 80 ⁰ C in phosphoric acid, the highly corrosive effect and iron containers containing the Markierungsflüesißkeit, can corrode.

i09850 / U31

19574 25

-2-

This is very annoying, especially when using automatic marking devices, which are used when marking running, hot rolled steel strips or very hot billets must be used, as marking by hand is practical here is no longer possible. The well-known marking fluids namely cause rapid corrosion of the storage container and the spray nozzle and in extreme cases even the entire marking device becomes unusable due to corrosion. Since such marking devices are generally used in workplaces where the ambient temperature is high, the decomposition of the phosphate and thus the corrosion are practically impossible impede.

The present invention is intended to prevent these disadvantages and to provide a heat-resistant ink or marking liquid which does not cause corrosion.

This is achieved according to the invention in that the phosphate is in the form of a complex compound.

In practice, a ketallic compound is added to the phosphate serving as an adhesive, which reacts with the phosphate to form a non-corrosive, harmless salt complex.

With the heat-resistant marking liquid according to the invention can be marked not only metal surfaces, in particular steel surfaces at normal temperatures, but also the surfaces of bars or billets, the one very high temperature, such as 800 to 1200 ° C, before rolling be marked. Since the marking fluid or ink according to the invention is heat-resistant, it does not disappear and it does not become unrecognizable when the marked steel products move from room temperature to an elevated temperature, such as 200 to 800 ° C, for hardening, post-annealing or rolling, or cooled from higher temperatures to room temperature will.

109850 / U31

ORIGINAL INSPECTSD

T957426

For the production of the heat-resistant marking liquid According to the invention, a pyrophosphate and / or another phosphate are preferably dissolved in water and an oxide or chloride of an alkaline earth metal, such as magnesium oxide, magnesium chloride, Calcium oxide or calcium chloride, or an oxide or chloride of a metal such as zinc, iron and the like. That Reacts with the phosphate to form a complex salt, added. The mixture is then, as long as necessary, touched. If the viscosity of the solution is too great for practical purposes, it is diluted with water and then becomes a Pigment added, and if necessary an additive to improve the heat resistance, a silicate, a surfactant, glass powder, glimmer powder, etc. added and dispersed, then a marking liquid, ink or suspension is obtained.

The percentage of the above materials is preferably those listed in the table below Areas. In this table and in the following explanations, all quantitative data are percentages or parts by weight.

Phosphate 20 - 70 %

heat-resistant pigment 5 - MO %

Water 40-80 %

Metal compound 5 - 20 %

Addition to improve the

Resistance to hitting. 0 - MO %

Silicate 0 - 50 %

Nonionic Surfactant 0-5 %

Glass powder 0 - 30 %

Mica powder 0 -10 %

109850 / U31

ORIGINAL! N8F £ CT £ D

Of the materials listed above, the phosphate melts at the elevated temperature and uses the surface of Metal, especially steel, is very cut and after cooling it solidifies and causes the pigment to adhere firmly on the steel surface.

For a more detail later illustrated embodiment of the invention, a Caleiumpyrophosphat, which is a calcium phosphate with a melting point of about 300 ⁰ C, however, one can also use other phosphate. -Plan preferably uses a phosphate whose melting point matches the heat treatment of the steel material to be marked as well as possible. Titanium white (titanium oxide) is preferably used as the heat-resistant pigment. As mentioned above, a wide variety of oxides or chlorides, for example, can be used as metal compounds if they form ions in water and a phosphate complex salt. In the embodiment mentioned, magnesium chloride is used. Clay such as china clay (kaolin) or hard clay can be used as a means of improving heat resistance. Silicate has the property of adhering firmly to steel surfaces both at room temperature and at high temperatures and, when the water evaporates, forms a film that adheres firmly to the steel surface at room temperature, which is usually not the case with phosphate. If a silicate is used, sodium or potassium silicate can be used. Non-ionic liquid-active agents improve the wetting capacity of the marking liquid, especially if the surface to be marked is wet or contaminated with oil.

If glass powder is used, then in particular finely powdered, low-melting glass can be used »because * serves as an adhesive and causes the pigment to adhere permanently. When using Qlimnerpulver a mutual solution dea Gliamerpulvers and phosphate at temperatures "occurs wipe about 400 and 600 ⁰ C and the falling dea pigments is prevented.

109850 / U31

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

In the following examples, the quantitative data are parts by weight.

Examples

iiatriuinpyrophoaphat 15th OK 0 10 Caleiuraphosphate 15th 10 20th 10 Magnesium chloride 5 5 10 5 Sodium silicate 0 10 10 10 water 40 50 40 40 Titanium white 10 15th 10 15th volume 10 0 0 0 Mica powder 5 0 0 5 Glass powder 0 0 10 5 Non-ionic limit area active agent 2 2 2 2

In the case of marking fluids but production of Heat-resistant markings according to the above examples, the sodium pyrophosphate and / or calcium phosphate react old the magnesium chloride with the formation of a stable complex. Even if these marking fluids in a very used or stored in a warm environment, see The phosphate does not form phosphoric acid like it does with the well-known hit-resistant marking fluids or colors is the case and also when stored in one

109850/1431

-6-

Metal containers do not corrode with the present marking fluids. Even if the hit-resistant Harkferungsflüasigkeit the invention in an automatic Markierungsiaaachine for marking a high-speed rolled steel sheet or a very hot billet or billet, whose temperature is 800 to 120 ° C »where marking by hand would be very difficult, hosting and Corrosion of the automatic marking device, in particular the storage container for the marking * liquid and the. prit -! nozzle and thus ensures a long service life of the marking device, which is relatively expensive in practice. The hit-resistant marking fluid according to the invention also provides clear white markings on materials at normal temperature, it provides very clear, white ₃ enamel-like markings when the marked material is ^{heated up to about 500 °} C. for hardening, afterglow or orphans 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 is cooled down quickly, also against mechanical stress such as heating, they are very resistant. On the other hand, if a steel plate or the like marked with the present heat-resistant marking liquid is heated and rolled by means of "orphans, the" marking does not stick in the rollers. The heat-resistant © Markierungsflüseigkeit geaäss of the invention therefore is particularly well suited ssur marking of billets or ingots of high temperature before the orphaned or blooming process and the use of automatic Markierungsaasohinen without any corrosion of these machines would% u feared.

1098B0 / U31

Claims (1)

-7- Claims i.) Hitselbständige ink consisting of an aqueous solution einee phosphate and fine particles containing a _s hitsebeständiges pigment and are suspended in the solution, characterized gekenrizei ehnet that the phosphate in the form of a ftompIexverbindung present. 2.) Resistant ink according to claim i, dad ü r cn ge ke η η se ich η et that the aqueous PhOBphatlosuns is a solution of a phosphate and a 'letallverbindunE, the Metsllionen in water unö forms a coraplex salt of the phosphate. 3 ·) Hit-resistant ink according to claim 1, since d u r c h Kekennsteichnet that the aqueous phosphate solution also contains a silicate. ¹ I.) Heat-resistant ink according to claim 1, ₃ , 2 or 3, characterized in that the aqueous phosphate solution also contains a surface-active agent (surfactant). 5.) Heat-resistant ink according to claim 1, 2 _# 3 or 1, d ad ur c hge know % ö I η β t that the Feet material particles also contain clay. 0.) HiteebeetänäigeTinte according to any one of the preceding claims, characterized% Eke η η is leveled "that the solid particles contain ausserdeia powdered mica * 1 Ö 9 85 0 / U 3 1 BAD Ctf? IQ, _NAL 7.) Hit-resistant ink according to one of the preceding claims, characterized _Λ that the Pestatoff particles also contain glass powder. t 09 8 50 / U-31; BAD OFIIGINAL