DE1519395A1 - Coating and process for its manufacture - Google Patents

Description

DR. A. MENTZEL DIFL.-ING. W. DAHLKE PATENT LAWYERS

1518395

50β REFRATH b. κοιν. June 2, 1964

PHANKENFOHST 187 Da./Κ » TELEPHONE: BENSBSHe β42OO

Εχρλί

Teleflex Incorporated

llortli'JaIe s, Peimsylvania, USA

Coating and process for its manufacture

The invention concerns substances for protective coatings and represents a further development of the drainages that under the file numbers T 23 319, ΐ 23 346, T 23 347, IVc / 22g have been registered.

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009852/1987

In the previously mentioned patent applications numerous examples of substances for protective coatings were disclosed, which all have in common that the excellent results, as described, when applied to the surface or surfaces, to be coated and then cured by heat. This is a Composition consisting essentially of a uniform mixture or dispersion of a solid, finely divided material consists in an aqueous solution and has substantial proportions of phosphate, metal, ohromat, dichromate or lolybdate ions contains.

It has now been found that results are far better can be achieved when the concentration of the phosphate ions in the aqueous solution is 1-4 mol / l, the concentration of the Ghromat and / or molybdate ions 0.5-3 mol / l, and the concentration of metal ions Contains 1-4 mol / l. If earomations are used, as is preferably done, they can be present as such be or as dichromate ions; for the sake of simplicity, this is here specified molar concentration for this ion is calculated under the assumption that it is always present as an Ohromat, although it is in the in most cases wholly or partially as a dichronate ion.

Said solid material should have at most a grain size of less than approx. 100 meshes, through a lüO-meshed Sieve falls through, better even a 325-mesh or noon finer one

009852/1987

Sieve. Various metallic or non-metallic materials can be used for this; the exact choice depends on the properties required of the coatings. As indicated in one of the aforementioned patent applications, various materials can be used as specified below. Used alone or in conjunction with other finely divided Y / er materials, particularly advantageous. Where lubricity is required, materials such as graphite, molybdenum disulfide or the like are used. It has been found that the amount of finely divided material added to the solution can be between 10 - 2,000 g / l. The optimum proportion depends on the specific intended use of the composition and, assuming proportions by weight, on the weight of the finely divided material. In most cases, however, the preferred range is between 300-1,000 g / 1,000 ecm of the phosphate-chromate-metal-ion solution. When using aluminum powder, a ratio of 800 g to 1 _o Q00 ecm would be optimal.

The phosphate anion can be introduced into the aqueous solution either in the form of phosphoric acid, or in the form of phosphates, the metal or the metals which are to be introduced as metal cations. However, both forms can also preferably be used. It is to be understood that the term "phosphate" includes not only the VO, ions, but also the HPO, and H ₂ PO, ions. All three result, for example, from the ionization of Η-, ΡΟ ,,

• 009852/1987 BAD 0RK3INA1.

and the hydrogen-phosphate ion complexes are generally, but at least to some extent, be present in the composition according to this invention. When phosphoric acid as an additive for the compositions used, it is advisable to use the ortho acid H ^ PO, although the The invention also encompasses the use of the other forms such as the meta or pyro acids, all of which are phosphate anions in water split off.

The odorate or dichromate anion can either be used as chromic acid or as its acid anhydride GrO ,, or as a chromate or Dichromate of the metal or the desired metals used as metal cations can be added. Compounds of Acid " and the metal salts can of course also be used. If molybdate anions are used, they can be used as molybdic acid or added as acid anhydride MoO * or as metal molybdate will.

The metal cations can be either as metal phosphate, chromate, dichromate or, if molybdate ions are desired, as Metal molybdate are added, all in the manner already indicated above. The metal can continue either all at once or partially added in the form of oxide, hydroxide or carbonate, which dissolve in phosphoric acid or chromic acid and provide the metal phosphate or chromate. Uenn carbonate is used, carbon dioxide will of course develop from it. It is undoubtedly the case that if the metal is, for example, an oxide,

009852/1987

ORIGWASS BATHROOM -

is added, at least part of the phosphate, Ohromats o.der Molybdates must be added as an acid or as an acid anhydride in order to achieve the acidity required for the acid-base reaction. + 2- and + 3-valent metal cations are preferred; for most uses of the compositions are magnesium ions, extremely beneficial

example 1

Aluminum (spherical, 5-10 / u) phosphate-chromate-metal-ion solution Solution from the following mixture:

Η, ΡΟ. (85 ^ -aqueous solution)

Mg (H ₄ PO ₄ ) ₂ . 3H ₂ O

MgOr ₂ O ₇ . 6H ₂ O

v / ater

The calculation shows that the solution contains about 3 m / l phosphate ions, Contains 1 m / l chromate ions and 2 m / l metal (magnesium) ions,

The order in which the ingredients are added in the composition of the phosphate chromate (dichromate) - metal-ion solution - is not critical, although it is generally easier to prepare an aqueous phosphoric acid solution first and then the to add other required components, whereby the

0 098 52/1987

80 G 1 00 ecm 20th ecm 5 G 5 G 15th G to 1 00 ecm

the last added ingredients from the finely divided solid material "exist which, when mixed thoroughly with the phosphate-chromate-metal-ion solution, form a pulp" Letting it stand can of course settle the solid material, and therefore it is generally advisable to briefly remove the mass Use stirring to make them uniform again. The compositions have a good shelf life, albeit at t some finely divided materials a reaction between the solution and the solid material, which, however, has no noticeable disadvantage. Where e.g. aluminum powder as If solid, finely divided material is used, a slight reaction can occur, which can be seen in the development of a green color recognizes on standing, apparently due to the reduction of some chromate ions.

The prepared composition, i.e. the mixture of solid, finely divided material and the phosphate-chromate-metal- ' Ion solution is applied by spraying, dipping, rolling or brushing the surface to be coated and then cured by heating, for which a temperature of 260 ° 0 to 540 ° C is required. The best curing temperature depends the exact composition abj is generally preferred however, a curing temperature of approximately 320 ° Q. up to 430 ° G. After curing is complete, the coating is insoluble in water, auoh during a longer time. If the curing is incomplete, the components of the solution contained in the composition will leach out, if exposed to water and this is evident

009852/1987

f ""

visible through the yellowish or orange "discoloration of the Cliromat-Ions, if e.g. with a damp cloth over a Wipes uncured or incompletely cured surface. The time required for curing depends on the temperature level; the higher the temperature, the less time it takes needed. For example, for a relatively slow curing of a coating at a low temperature, approx. 15-60 minutes at 320 °. needed Where rapid cure is required, needed one about 5-10 minutes at a temperature of 430 ° C. To a pronounced To achieve rapid curing, one can even use thermal radiation at an even higher temperature to advantage; this is particularly advantageous if the base to be coated is made of a not very heat-resistant material, since the at high temperature achieved heat rays cure the coating completely, but without excessively high temperatures in the base to create.

The heat curing of the composition to the point of insolubility in "Jasser is important to get the physical you want To achieve properties. From this round it is clear that that solid, finely divided material resistant to the hardening temperature must be without decomposing.

The thickness of the coating after curing should preferably be between 0.01 and 0.5 mm; therefore should be the exact Concentration of the liquid composition and that of the IJenge be adjusted accordingly. In some cases it is necessary

0 09852/1987

borrowed to use two or more coatings, if necessary. With Zwisohenhärtung.

The compositions of the invention have excellent properties in terms of surface tension and therefore üenetzen the base very well, even if it is a v / erkstoif is that is difficult to moisten h ater. Organic wetting agents are therefore not required to achieve a smooth and uniform coating. The surface to be coated should of course be clean. Although smooth surfaces do not necessarily have to be roughened prior to coating, it does provide optimal adhesive strength.

As already indicated above, "coating compositions achieves v / earths which have a remarkable and indeed unique combination of desirable physical properties such as the following:

1.) high corrosion resistance - sufficiently resistant to, for example, over 250 hours and a maximum of 3,000 8td. to be able to remain in a corrosion chamber enriched with 5% salt mist;

2,) high heat resistance on the order of the heat resistance expected of ceramics ;

3) high adhesion even with surfaces which are otherwise difficult to prove and over a wide temperature-

009852/1987

temperature range down to -180 ° O.j.

4.) high abrasion resistance, again in the order of magnitude of the abrasion resistance of good ceramic materials and finally

5.) good flexibility, as is normally only found in organic coatings, but not in ceramic coatings, expected.

Of course, other desirable physical properties can be imparted to the coating by appropriate means Selection based on the firm, finely divided material used for the coating. For example, it can be excellent electrical conductivity can be achieved by using aluminum powder as a solid material, excellent electrical insulating property on the other hand, by using aluminum oxide. Particularly heat-resistant, lubricious coatings are achieved through the use of graphite, molybdenum disulfide, tungsten disulfide, lead oxide or others ! Dry lubricant reached. Furthermore, all of the desirable physical properties enumerated above, E.g. the heat resistance, on a larger scale through the choice of the solid, finely divided material can be achieved. For example higher heat resistance is achieved by using boron nitride as a solid material.

Often it is also desirable to use a combination of two solid materials of the solid, finely divided material in order to achieve a certain range of physical properties reach. E.g. molybdenum sulphide and molybdenum disilioid can be added

009852/1987

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used together to obtain an excellent heat-resistant, lubricious coating with "particularly good abrasion resistance." Other representations within the many desirable physical properties to be achieved will emerge the following examples, which are proposed here according to the invention.

No specific reasons or perfect explanations can be given as to the excellent physical properties that can be achieved. What is known, however, is. that the properties are far better than those which one would expect from combinations of the said solid Y / er material and the phosphate-Ohromat-metal-ion solution. Wewa. For example, sheet steel is coated according to the invention with a composition that contains aluminum powder as a solid material, so the sheet steel will lose a much higher heat resistance as a result, namely: in addition there is excellent flexibility, Korrieiojie-

"resistance and other properties. You additional properties when using aluminum and a phosphate-Öhromat metal-ion solution cannot be decisive for this, especially with regard to the extremely high heat resistance and corrosion resistance, It can be assumed that the rewarded physical properties achieved in the present invention, at least in part by any physical Interrelationships iwieohan the individual components and the to be coated surface can be achieved. Apparently a chemical reaction between the particles does not occur because the

^ 009852/1987

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openable as such (i.e. roughly in the form in which it is composed are mixed in) persist after hardening and even after prolonged treatment at higher temperatures. V / ie Although there may be no need to explain it, the fact is that the compositions of this invention are unique in nature result in desirable physical properties not previously achievable.

One of the most important advantages of the present ER ä invention is that they bend the compositions as coatings with their substrate, deform and possibly even may be welded., L.iit other 'means locate / "that that the compositions are applicable to a base material, for example wire, tape or the like, which can then be drawn, processed, bent or otherwise deformed without the "coating" being torn. In fact, in many cases it has been found that the strength of the bond between the coating and the base is increased by mechanical processing. The compositions have been successfully applied to non-metallic surfaces such as plastic, paper, fibers, ceramics, wood, etc.

As mentioned earlier, phosphate, chromate and metal ions can be admixed in different forms of the composition, i.e. as acids or acid anhydrides, metal salts or whatever the Metal ions are concerned, in a form that dissolves in the acid and makes metal salts in place. Below will be

009852/1987

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some preferably applicable compounds of the various ions indicated, which are suitable as additives:

Phosphate ions; Ortho, meta, pyro or hypophosphorous acid. The ortho acid is mostly preferred; of monobasic dibasic and tribasic metal phosphate salts, preferably -f2- or +3 valent metals, the ilagnesium salts being most desirable. The metal phosphate should of course be soluble in the solution in order to be able to dissolve in the solution, although this should not mean that high solubility in water is necessary, since many phosphates, which are not very soluble in water, are nonetheless in acid are sufficiently soluble, at least to a small extent, if one of the other solution ingredients forms the acid.

\ 7ill however, the solution is particularly easy to produce and To achieve the best properties, one should predominantly use monobasic or dibasic salts and not tribasic salts.

From the above mentioned LetaXlphosp, aten come in handy for the exercise this Jiri'induiii-, only those mentioned below in question Understand it »I, you Js the addition of either al υ anhyurn s-cheü salt can be done or, vus in general better and wirtnoliaftli rather is, as a hydrate:

Honoba-uisciic.j LlagiieuiuinphospLat, dibasic iin ^ nuuiiuin , mono bauisoliuG Ziiikplioi-spiiut, tri basd ache ;; 'ΐ .1 i 11 ^ ρ J ι ο t.5 j > 11; t

009852/1987 BAD ORIGINAL

Aluminum phosphate, ferric phosphate, ferric pyrophosphate, ferrophosphate, monobasic calcium orthophosphate, dibasic calcium orthophosphate, monobasic lithium phosphate, tribasic lithium phosphate.

Ohromat- (or Siohromat) ions: chromic acid (or öhromic anhydride, OrO. *); Ohromat or dichromate salts, preferably of + 2- or + 3-valent metals. Magnesium salt is preferably used.

With the now following ohromate-containing compounds in the frame the above selection can be added as a hydrate;

Chromic acid, magnesium chromate, magnesium dihrate, zinc chromate, Zinc dichromate, calcium diohrate, lithium diohrate and Magnesium dichromate together with sodium dichromate. If you can If you want to replace odorization in whole or in part with molybdation, any of the following compounds can be used: "

Molybdic acid, H _{2 MoO.} or Mo, j molybdates + 2- or + 3-valent metals, where zinc molybdate is ZnIvIoO . is preferred, there is no particular advantage in using molybdenum for all

To use settlements according to the invention, especially since molybdenum compounds fertilize are expensive. In addition, you don't get so good with it Properties as with Ohromat.

Metal ions: If phosphate and / or Ohromat or IJolyb

009852/1987

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dat ions are put into solution together with a metal salt, they also supply metal ions by themselves. Deslialb can all of the already mentioned phosphates, chromates, iiichromates or Molybdates can be used as a source of metal ions. As already indicated, additional metal ions can be added in the form of e.g. metal oxide, hydroxide, carbonate etc., which dissolve in an acid, i.e. in phosphoric acid, chromium or molyb

k danic acids to produce the metal phosphate, chromate or molybdate and thus also the metal ion, with water and / or gas also developing. If of course the metal ion in this one Form is mixed in, the other ingredients supply the solution with the acids that are required for the acid base reaction. For example, as is preferably also done, some of the phosphate ions could be added as phosphoric acid, or a Part of the Ohromat ions as chromic acid. The following metal compounds can be used to generate metal ions in the solution for the acid base reaction according to the above

"Versions:

Magnesia MgO; Magnesium hydroxide Mg (OH) ₂ ; lithium carbonate Ii ₂ OO ,; Calcium hydroxide Oa (OH) ₂ .

It goes without saying that the insoluble refractories Metal oxides, which are generally used for the manufacture of ceramic goods (such as aluminum oxide) and which are known as the aforementioned feates material can be used nioht easily as Motall-ion additives can be processed as these oxides

009852/1987

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Difficult, if at all, due to their physical nature even in strong acids, are soluble.

In general, +2 and +3 valent metals are preferred; Magnesium is excellent, although the iron and aluminum ions, which are +3 valent, are beneficial for many compounds. Although zinc ions are not as good as magnesium, it is used. The +1 valent metals such as lithium, sodium and potassium can also be used, although they do not always have the same advantages. If an alkali metal is used, it is usually only used in small amounts, and indeed not more than 30 iuol ^c / j of the total metal ion concentration. Apparently it means a ί protection: if enough of the desirable + 2- or + 3-v / ertigen metal ions, e.g. magnesium, are present, against the other undesirable properties of the alkali metals, aemi two such undesirable properties are a reduced corrosion resistance and the lower flexibility. In general, there is only one advantage in _{using such + 1-valent Λ} ketals, and they are cheaper, for example, sodium dichromate is somewhat cheaper than magnesium dichromate. Silver, although it is satisfactorily intact, is not as good as the preferred + 2 and + 3 -. Verti ^ en metals and also has the ITacliteii that it is considerably expensive? ¹ is.

In order to achieve the highest corrosion resistance, the i.Ietall-loueu-Kon: -: entration should be at least approx. 1.5 mol / l.

a multi-valued, i.e. +2 or +3-valued bond deposit, with-

009852/1987

For example, magnesium is used, it is useful if the molar concentration is at most half as large as the total molar concentration of phosphate and chromate (and / or molybdate) ions is “At the same time, however, the ratio of the metal ion concentration to the phosphate and otomate ion concentration should

tion be as follows:

1 mole (metal ions): 2 moles (phosphate + ghromat, and / or "liolybdate). For example, in the most preferred compositions, in where all metal cations are + 2-valent, especially in the case of magnesium, that Ratio of metal: phosphate: chromate molar concentrations approximately 2: 3: 1.

In practice within the scope of this invention, the following materials of solid, finely divided material are preferred:

1.) uiii to achieve good abrasion resistance, for liitzebefc durability, corrosion resistance and furthermore good electrical or heat conductivity to a decorative, metallic To maintain appearance and optimal flexibility, e.g. powders of metals, copper, silver, nickel or aluminum, the latter mainly in spherical form, most preferred.

2.) about electrical insulating properties or extremely high ones To achieve heat resistance, one uses the refractory ones Metal oxides such as silicon dioxide, zirconia, beryllium oxide or preferably aluminum oxide, e.g. as aluminum hydrate, corundum,

009852/1987

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Alundum or fused aluminum oxide, all materials that generally used in the manufacture of ceramic articles;

3.) Furthermore, in order to achieve special heat resistance or, in some cases, extremely high abrasion resistance, or to achieve electrical semiconductivity, the refractory carbides, nitrides, silicides and borides, such as silicon carbide, tungsten carbide, boron nitride or molybdenum disilicide are used

4.) Dry lubricants such as lead oxide, graphite, foIf ram disulphide and molybdenum disulphide are used to achieve slidability or lubricity.

Other finely divided solid materials, which are used for various special applications are: glass, Bleimetasilicat, cadmium fluoride, Oalciumfluorid, titanium hydride, sublimated, leaded ( "fumed leaded zinc oxide") zinc oxide, zirconium silicate, magnesium A silicate, titanates and zirconates.

The following additional specific examples of compositions are intended to further illustrate the invention:

example 1

A steel plate made of ordinary steel (SAE 1010) comes with the composition coated by spraying, dried at 27 ° 0 and then at about 330 ° 0 for 15 minutes.

009852/1987

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hardens. The coated material can be U-shaped with a small The radius of curvature can be bent and then practically bent back into its original shape without the coating cracking or peeling off. The corrosion resistance is extremely high; the coated material holds a $ 5 treat Salt mist-enriched chamber for 2,500 hours without visibly losing any of its value.

W A piece of the coated steel is placed in a furnace next to an uncoated piece of the same steel. When the temperature has risen approximately to 1040 ° 0, the uncoated piece will dissolve into its constituent parts, while the coated piece will remain completely undamaged. In fact, a sheet of ordinary steel coated in this way outperforms a much more expensive sheet of stainless steel by about twice as much in terms of heat and corrosion resistance.

Example 2 266 G- MgGrO ₄ . 7H ₂ O 98 G H ₃ PO ₄ 272 G Mg (H ₂ PO ₄ ) ₂ -. 3H ₂ O up to 1,000 ο cm H ₂ O Aluminum powder 6oo G (spherical 5-10 / u)

The test was carried out in accordance with the above-mentioned example 1 with regard to adhesiveness and corrosion resistance with similar

009852/1987

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results. Coated with composite Sheet steel, cured at 530 ° C. for 15 minutes, withstood treatment at 570 ° C. for 100 hours, without malfunction Attack.

Example 3

Composition according to Example 2 with the following exception: 600 g of aluminum oxide were used instead of the aluminum powder (Sieve size 325 mesh) added to the solution as a solid material. This composition was coated on stainless steel of the type and then cured at 340 ° C for 30 minutes. The overdone Steel was then treated for 200 hours at 760.degree. C. without noticeable damage to the coating.

Example 4

Composition according to example 2 with the difference, that instead of the aluminum powder 500 g boron nitride (screen size 325 ™ Mesh) were added to the solution as a solid material. The coating was made on Type 321 stainless steel and Cured at 340 0 for 30 minutes. The coating withstood 980 C. for 50 hours without noticeable damage

Example 5

Similar to Example 4 except that instead of the aluminum

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009852/1987

powder 800 g of silicon carbide (600 mesh screen) was added to the solution as "said solid material. The results were as in Example 4. The coating had remarkably good abrasion resistance.

Example 6

Composition according to Example 2, except that instead of of the aluminum powder 300 g graphite (5-10 / u) of the solution as a solid Material was attached. Steel (SAB 1010) was coated and Cured for 30 minutes at 320 ° 0. Excellent lubricity; also excellent for use in nuclear reactors. Heat and oxidation resistant up to 430 C.

Example 7 Aluminum powder 5-10 λχ) 92 G OrO, (spherical 323 G H ₅ PO ₄ 72 G MgO 1000 ecm H ₂ O up to 800 G

The composition was coated on ceramic and 30 Cured for minutes at 370 ° 0. Excellent thermal and electrical conductivity. Heat resistance similar to that of

Example 2.

BATH ORIGINAL 009852/1987 - .i -

Example 8

HgGr ₂ O _7, 6H ₂ O up to 348 G G H ₅ PO ₄ 98 G Hg (H ₂ PO ₄ ) ₂ . 3H ₂ O 1. 272 G H ₂ O 1000 ecm Molybdenum disilicide. (Sieve size 325 meshes) 000

Metallic molybdenum was coated with this composition; Cured for 10 minutes at 430 °. Resistant to oxidation at 1,090 ° 0.

Example 9

'3
H ₃ H) ₄

MOH

H ₂ O

OrO, 100 g

294 g 72 g

up to 1,000 ecm aluminum powder (5-10 al) 800 g

Was used as a coating and cured according to Example 7; Excellent thermal and electrical conductivity % Heat resistance as with the composition according to Example 2, but this composition is flexible in terms of mf. not as good as having a + 2-valent metal as in Bei- 7

009852/1987

BATH ORIGINAL

- 2i

Example 10

CaCr ₂ O ₇ . 3H ₂ O 310 g

H ₅ PO ₄ 294 g

H ₂ O up to 1,000 ecm aluminum powder
. (5-10 / u) 800 g

Applied for joining two test pieces of ceramic tiles. Cured for 30 minutes at 330 ° C. About a 3 square cm piece of the bonded piece withstood a tensile force of over 45 kg without breaking.

Example 11 174 G ecm G MgCr ₂ O ₇ . 6H ₂ O 75 G Na ₂ Cr ₂ O ₇ . 2H ₂ O 40 G MgO 196 G H ₃ PO ₄ up to 1000 HgO Silicon dioxide 800 (Sieve size 325 Masahen)

Be was coated with stainless steel, cured for 10 minutes at 370 ° C *. The heat resistance was as in Example 3 <

009852/1987 - 23 -

example AlPO ₄ 12th 122 G CrO ₅ 100 G H ₅ PO ₄ 98 G H ₂ O to 1000 ecm Aluminum powder until (5-10 / u) 700 G

Coated and cured according to Example 7 with similar results.

Example 15

IJgOr ₂ O ₇ .6H ₂ O 174 g

J? E _3. (PO ₄ ) ₂ . 8H ₂ O 112 g

H ₅ PO ₄ 196 g

H ₂ O up to 1,000 ecm

Silver (screen size 325

Mesh) 600 g

Plating was done on ceramics; For 30 minutes at 340 ° C. hardened. Excellent electrical and thermal conductivity.

Example I4
MgCr _? 0 ₇ . 6HpO 88 g

0098 5 2/1987

-

OrO ₃
Mg (H ₂ PO ₄ ). 3H ₂ O 50 g
272 g MgO 5 g H ₂ O up to 1,000 ecm Aluminum powder (5-10 / u) 600 g

Coated, cured and tested according to Example 2 "with comparable results, although not as excellent as in example 2 with regard to the adhesion after the bending test in terms of corrosion resistance.

4th Example 15 (85? Δ) 200 ecm 60 g G H ₅ PO 2 ° 7 . 6H ₂ O 1 50 g com MgCr 50 g MgO ₂ P0 4 ^{V ;:} · 3H 2 ^Ü Mg (H D there ndisulfide .000 MoIy 5 ^ u max particle size) 800-1 .000 (6 until to 1 H ₂ O

Cured for 30 minutes at 330 ° C.

Such a composition can be used in many ways as a solid lubricating film and is particularly suitable for use in Temperatures from -180 ° C. up to + 400 ° C. The following combination

009852/1987

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setting is particularly applicable to ??? (anti-gallant) coatings that Can withstand temperatures of up to about 730 G.

Example 16 50 H ₃ PO ₄ (85 .6H ₂ O MgGr ₂ O ₇ MgO ZnGrO ₄ 50 VoI , - ^ Lead oxide 50 YoI .- <fo graphite

250 ecm 160 g 50 g 40 g

600 - 800 g

Cured at 330G for 30 minutes.

Although in all the preferred embodiments of the invention the concentrations of the various ions are in the above-mentioned ranges, somewhat smaller amounts of Ohromat can be used in some applications, namely down to eu down to 0.3 mol / l of the solution and metal down to 0, 5 mol / l of the solution should be added.

009852/1987

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Claims (15)

Claims 1. Mass for covering or binding workpiece surfaces, characterized by a dispersion of a solid substance in an aqueous solution, the phosphate ions, Metal ions and Ohromat and / or molybdate ions contains, the dispersed solid substance being contained in the solution in an amount of 10 - 2,000 g / l. 2. Composition according to claim 1, characterized in that the aqueous solution contains the phosphate ions in a concentration of 0.5-4 mol / l. 3. Composition according to claim 1 and 2, characterized in that the aqueous solution contains the phosphate ions in a concentration of 1-4 mol / l, the Ohromat and / or molybdate ions in a concentration of 0.5-3 mol / l and contains metal ions in a concentration of 1-4 mol / l. 4. Composition according to claims 1-3 »characterized in that the dispersed solid substance has a maximum grain size corresponding to a mesh size of 100 meshes. 5. Composition according to claims 3 and 4, characterized in that when the chromate ions are used as anions, the metal ions are selected entirely or at least predominantly from the group of +2 and +3-valent metals. - 27 -009852/1917 6. mass according to claim. 1 to 5, characterized in that as the dispersed solid substance, a metal powder or a powdery, refractory oxide, carbide, nitride or silicide or a dry lubricant, each at a maximum Grain size corresponding to a mesh size of 325 meshes, is selected. 7. Composition according to claim 1 to 5, characterized in that, when using Öhromat ions as anions, magnesium ions can be used as metal ions. 8. Composition according to claim 3 to 7, characterized in that the amount of the dispersed solid substance is 300-1000 g / l of the solution. 9. Composition according to claim 1 to 7, characterized in that the metal ion concentration, measured in mol / l, when used + Bivalent metals is about half as large as the total concentration of phosphate and Öhromat ions. 10. Composition according to claim 1 to 9 »characterized in that magnesium ions are used as metal ions and that the ratio of the concentrations of phosphate ions to chromate ions to metal ions, measured in mol / l, is about 3 ί 1: 2. 11. Mass according to claim 6 and 8, characterized in that - 009852/1987 - 28 - aluminum powder is used as the dispersed solid substance. 12. mass naoh claim 1 to 11, characterized in that the aqueous solution of orthophosphoric acid and at least one compound from the group consisting of chromic acid and metal chromates, Metal dichromates, molybdic acid and metal molybdates and at least one compound from the group of oxides, hydroxides, - Contains carbonates and phosphates of magnesium, zinc, aluminum and iron. 13 · Composition according to claim 12, characterized in that the dispersed solid substance in an amount of 300-1000 g / l Solution exists. 14. Method for producing a coating b ^ w. a tie layer by means of a mass according to claims 1 to 13 »characterized in that the mass, with the most homogeneous possible f division of the solid body parts dispersed in it. the surface of a workpiece to be coated is applied and then cured by the action of heat until it is insoluble in water. 15. The method according to claim 14 »characterized in that the Curing takes place at a temperature of at least 260 ° C. 009852/1987