DE1278663B - Use of borophosphorus oxides as lubricants - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN WTWW ^ PATENT OFFICE

EDITORIAL

Int. Cl .:

ClOm

German class: 23 c -1/01

Number:
File number:
Registration date:
Display day:

P 12 78 663.9-43 (S 93817)

October 21, 1964

26th September 1968

The invention relates to the use of borophosphorus oxides in solid form as powder, threads or fibers to reduce the coefficient of friction between sliding surfaces, optionally in Processing with other mineral products. The boron phosphorus oxides can, for. B. in materials, which are suitable for the production of bearing bushings, bearings, thrust bearings, sliding shoes, etc. are used will.

Borophosphorus oxides, P ₂ O ₅ · B ₂ O ₃ , have been described, e.g. B. a product that can be prepared by reacting 1 mole of orthophosphoric acid with 1 mole of boric acid.

This mixed oxide, which is represented as a defined product, can be mixed with bases according to the following Reaction to be implemented:

-B ₂ O ₃ + 2 NaOH-

• B ₂ O ₃ • 2NaOH

A material of the formula has also been described

wherein M is an alkali metal, and this product can be obtained by mixing boric acid with a pyrophosphate can be obtained. However, nothing has been reported that these products have lubricating properties and can be used as lubricants.

It has also been described to introduce derivatives of phosphorus and boron into glasses that are viscous Condition when hot extrusion of various metals are used as lubricants. Here various products are used that contain boron and / or phosphorus in the form of a solution. However, these methods of hot deformation are different from the field for which the products are to be used come according to the invention in question.

From the German patent specification 1050 486 a lubricant is known, which consists of a mixture Alkali tetraborate with a meta-, ortho- or pyrophosphate of an alkali metal. The state diagram these two components should have a eutectic. This is also the proof for the fact that the alkali tetraborate and the alkali metal phosphate are present side by side and not in Can be used in the form of a uniform connection. This known lubricant lies during the lubrication process as a melt.

In contrast to this, the invention relates to the use of a lubricant which is present as a solid body during the lubrication process. Counter-use of borophosphorus oxides as
lubricant

Applicant:

Societe Industrielle des Coussinets, Paris

Representative:

Dr. H. G. Eggert, patent attorney,

5000 Cologne-Lindenthal, Peter-Kintgen-Str. 2

Named as inventor:

Georges Hermann,

Annecy, Haute Savoie (France)

Claimed priority:

France of October 22, 1963 (951 339)

The invention relates to the use of borophosphorus oxides of the general formula

P ₂ O ₅ · nB ₂ O ₃ · / MiM ₂ O · ρH ₂ O,

in which η 1.5 to 2, m 1.5 to 2.5, ρ 0.5 to 2 and M denotes an alkali metal, as a solid lubricant, optionally in a mixture with other substances. The borophosphorus oxides used according to the invention thus contain phosphoric anhydride, boric anhydride and an oxide of an alkali metal in a bound state.

A preferred embodiment of the invention consists in the use of boron phosphorus oxides, which after the addition of one or more phosphates, especially those of beryllium, calcium, Magnesium, iron or aluminum, subjected to heat treatments to reduce residual moisture are used as lubricants. The use of borophosphorus oxides is also recommended for the same purpose, after the addition of one or more oxides, in particular aluminum, lead, magnesium, calcium, iron or beryllium have been sintered at at least 400 ° C.

The invention also relates to the use of the various aforementioned boron

809 618/498

phosphorus oxides as lubricants after their incorporation in natural or synthetic, thermoplastic or thermosetting compounds.

Products in which P ₂ O ₅ , B ₂ O ₃ , M ₂ O and H ₂ O are bound alone in the proportions given above have desirable lubricating properties, but can only be used in the absence of external moisture. In the following description, they are often referred to as »basic

Boric acid, the proportions between these acids corresponding to the proportions, that are desired in the end product. The acid syrup obtained is also at 100 to 130 ° C with neutralized with an alkali hydroxide. The amount of alkali hydroxide, which is generally in the form of anhydrous product or as a concentrated solution is added, is calculated so that the final pH of the syrup is between 1.5 and 8. Ge

products «. Products are preferred; the hydroxides of various alkali metals are suitable which these compounds with at least one metal.

of the above metal oxides are combined. The dehydration takes place at a temperature

Apart from the lubricating properties that made those above 250 ⁰ C and below

Basic products are common, these are pro-melting point. By becoming free

ducts are not hygroscopic and the material swells compared to the water vapor

Insensitive to the effects of moisture. instead, which gives it the appearance of a

It can be advantageous to give the above-mentioned foamy mass, from which one

wrote products of the action of a current by light rubbing a very fine, very light one

subject to dry ammonia gas. It powder with the desired lubricating properties

can also be advantageous, the mixtures that can be obtained by 20.

Adding a phosphate to a base product for ER- _for manufacturing products with phosphorus

will hold twice or more frequently in succession of beryllium, calcium, magnesium, iron

to subject the following heat treatments. One _{mixes a 0} ^ _{egg of} aluminum as a modifier

such repetition has a reduction in the residual amount of the neutralized syrup prior to dehydration

moisture content in the product as well as the transmission _and expansion with soluble phosphates of the

reduction of its density. Berylliums, calcium, magnesium, divalent

The products or trivalent iron or aluminum to be used according to the invention, these

have the form of a fine, very soft powder, phosphates can be in the form of a solid or as

that can easily be put into the form of a paste and added to the solution. The mixture should be great

process in this form into threads or fibers 30 be homogeneous before it is on the dehydration

leaves. Their bulk density in powder form fluctuates as the temperature is brought. Particularly advantageous within wide limits. You can use both powder
with a bulk density of 0.03 as well as powder
obtained with a bulk density of 1. Regarding
the lubricating properties of the products are between 35
see molybdenum bisulfide and graphite, however
they do not suffer the disadvantage of graphite, under the
To break up or crumble under the action of friction.

A basic product in which the is usually used in the form of solutions is particularly favorable

η a value of about 2, m a value of. Those to be added to the neutralized syrup

about 2 and ρ has a value of about 1 and M amounts of phosphate can be very wide within

Sodium is. There are limits.

These basic products can be obtained in a known way by adding a certain amount of metal and subsequent dehydration by means of two successive reactions of phosphorus oxides used according to the invention. The oxides are to be obtained, then the basic reaction leads to an acidic derivative of the products after dehydration and swelling phosphorus and boron in the form of a viscous with the oxides, e.g. B. with PbO mixed. These syrups. The second reaction is a neutralization, mixing is done by simultaneously grinding the z. B. with sodium hydroxide, which leads to a practically 50 Oxydes and the selected basic product to a neutralized derivative of phosphorus, boron and sodium powder. The mixture is then at a trium in the form of a complex that also leads
is in a syrupy solution.

In the case of the above-mentioned derivative to be preferably used, these reactions can schematically by the following equations including the various suitable phosphates the aluminum phosphate of the formula

H ₃ Al ₂ (POJ ₃ and the magnesium phosphate of the formula HMgPO ₄ ,

be asked:

2H ₃ PO ₄ + 4H ₃ BO ₃ = P ₂ O ₅ .

Sintered at a temperature of at least 400 ° C. If a powdered product is desired, done then a grind.

It was found that the product, starting at a level of 0.25 moles of PbO per mole

2B ₂ O ₃

3K.O + 6HX)

P ₂ O ₅ -2B ₂ O ₃ -3 H ₂ O + 4NaOH

= P ₂ 0 ₅ -2B ₂ 0 ₃ -2Na ₂ OH ₂ O + 4H ₂ O

These reactions take place between 100 and 130 ° C. The first reaction involves heating a mixture aqueous solutions of phosphoric acid and

P ₂ O ₅ • 2B ₂ O ₃ • 2Na ₂ O • H ₂ O

is no longer hygroscopic. It should be noted, however, that adding too large amounts of PbO would lead to an increase in the coefficient of friction.
As already mentioned, the products to be used according to the invention lie between molybdenum sulfide and graphite in terms of lubricating properties. If they are obtained in powder form, they can be used without changing their properties

a paste that enables it to be processed into threads, fibers or even molded parts. The fibers or threads can be particularly advantageous for the production of layered lubricious products. Regardless of their physical form, the boron phosphorus oxides also in natural or synthetic thermoplastic or thermosetting materials, e.g. B. rubber, Phenoplasts, silicones, epoxy resins, polyurethanes, polyesters, polyamides, polyethylene, polypropylene, fluorinated resins, polycarbonates, etc. can be incorporated. Through their admixture, the Flow and creeping temperatures are reduced, or these phenomena are completely eliminated. You can furthermore with metal powders or a mixture of a metal powder with one of the aforementioned natural or synthetic materials are combined, with lubricious materials obtained that are effective dry or with normal lubrication or with interfacial lubrication are.

The following examples illustrate the manufacture of certain products which contain the basic product in which n, m and ρ have a value of 2, 2 and 1, respectively, and can be used in accordance with the invention.

example 1

The basic product was prepared as follows: 1300 g of commercial phosphoric acid with a density of 1.6 and 620 g of a commercial boric acid _{solution with 56.3% B 2} O ₃ were mixed and heated to 115 ° C. until the boiling caused by this ceased. The reaction took a few minutes. The product had the appearance of a white, syrupy pulp. 500 g of flaky sodium hydroxide was then added with stirring to make the mixture homogeneous. Water was then slowly added to a final volume of 21. The neutralized syrup thus obtained had a pH of 4.4 and a density of about 1.5 at 20 ° C.

This syrup was then poured in a thin layer onto a metal sheet that was heated to 280 ° C was. Vigorous formation of water vapor was observed, which caused the product to swell. The foamy product thus obtained was very light. It was ground in a ball mill, a white powder was obtained which had a bulk density of 0.10 and was very felt soft. This slightly hygroscopic powder was tested for its lubricating properties. It lay in this regard close to graphite.

55 Example 2

135 g of aluminum granulate were digested with 1960 g of a commercially available phosphoric acid solution with a density of 1.6 at 20.degree. After the digestion, the volume was adjusted ^{to 2000 cm 3.} This solution was mixed with the same volume of the neutralized syrup obtained in Example 1.

After homogenization, this mixture was dehydrated by placing it directly on a cast iron plate was poured, which was heated to 280-300 ° C. The foamed product had a Composition which roughly corresponded to the following formula:

P ₂ O ₅ · 2B ₂ O ₃ ■ 2Na ₂ O · 0.25 [3 P ₂ O ₅ · 2Al ₂ O ₃ ]

This product was in the form of a non-hygroscopic powder with an apparent density of 0.09, which was between molybdenum bisulfide and graphite in terms of its lubricating properties.

Example 3

125.5 g of magnesium were digested at about 100 ° C. with 1300 g of commercially available phosphoric acid with a density of 1.6. After the digestion, the final volume was adjusted ^{to 2000 cm 3.} This solution was then mixed with the same volume of the neutralized syrup prepared according to Example 1. After homogenization, the mixture was placed in an oven to a temperature of about 300 ⁰ C. Vigorous evolution of water vapor was observed, which gave the product the appearance of a friable foam. By grinding this foam, a fine, white, non-hygroscopic powder with a bulk density of 0.08 was obtained which, in terms of its lubricating properties, was between molybdenum bisulfide and graphite.

A product is obtained analogously which contains aluminum phosphate and magnesium phosphate.

The bulk density was 0.05. The product had the same lubricating properties as those in the products described above.

Example 4

A homogeneous mixture of 400 g of that obtained according to Example 1 was obtained in a ball mill solid product made with 115 g of red lead oxide. This mixture was made within 30 seconds heated to about 800 ° C, causing it to sinter. This sintered product was then ground, whereby a non-hygroscopic white powder was obtained which had approximately the same lubricating properties had like the products described in the previous examples.

No protection is claimed for the manufacture of the products to be used according to the invention.

Claims (4)

Patent claims: 1. Use of borophosphorus oxides of the general formula P ₂ O ₅ · nB ₂ O ₃ · / JiM ₂ O · ρ H ₂ O, in which η 1.5 to 2, m 1.5 to 2.5, ρ 0.5 to 2 and M denotes an alkali metal, as a solid lubricant, optionally in a mixture with other substances. 2. Use of borophosphorus oxides which, after the addition of one or more phosphates, especially those of beryllium, calcium, magnesium, iron or aluminum, heat treatments to reduce the Residual moisture have been subjected for the purposes of claim 1. 3. Use of borophosphorus oxides which, after the addition of one or more oxides, 7 8 in particular of aluminum, lead, magnesium, claim 1 after their incorporation into natural Calcium, iron or beryllium, at least borrowed or synthetic, thermoplastic or 400 ° C have been sintered for the purpose of thermosetting masses. Claim 1. 4. Use of borophosphorus oxides according to 5 publications considered: one of claims 1 to 3 for the purposes of German Auslegeschrift No. 1050 486. 809 618/498 9.68 © Bundesdruckerei Berlin