EP2238227A1

EP2238227A1 - Method for coating metal surfaces with a phosphate layer and then with a polymer lubricant layer

Info

Publication number: EP2238227A1
Application number: EP09705226A
Authority: EP
Inventors: Uwe Rau; Klaus-Dieter Nittel; Andreas Lang
Original assignee: Chemetall GmbH
Current assignee: Chemetall GmbH
Priority date: 2008-01-30
Filing date: 2009-01-26
Publication date: 2010-10-13
Anticipated expiration: 2029-01-26
Also published as: WO2009095373A1; US9422503B2; BRPI0906356A2; ZA201005731B; PL2238227T3; CA2713541C; ES2523702T3; KR101633005B1; AU2009209697B2; KR20100111309A; DK2238227T3; UA102838C2; AU2009209697A1; PT2238227E; HUE026555T2; RU2010135780A; CL2009000227A1; CA2713541A1; RU2501848C2; TWI457433B

Abstract

The invention relates to a method for preparing metal workpieces for cold forming by first applying a phosphate layer and then applying a lubricant layer which has a major content in organic polymer material. The phosphate layer is formed by an aqueous acidic phosphating solution having a major content in calcium, magnesium or/and manganese and phosphate. The lubricant layer is formed by contacting the phosphated surface with an aqueous lubricant composition which has a content in organic polymer material based on ionomer and optionally also non-ionomer, the organic polymer material used predominantly being monomers, oligomers, co-oligomers, polymers or/and copolymers based on ionomer, acrylic acid/methacrylic acid, epoxide, ethylene, polyamide, propylene, styrene, urethane, the ester(s) or/and salt(s) thereof. The invention also relates to the corresponding lubricant composition, to the lubricant layer produced thereof and to its use.

Description

Method for coating metallic surfaces with a phosphate layer and then with a polymeric lubricant layer

The invention relates to a process for coating metallic surfaces first with an aqueous acidic phosphating solution and then with a lubricant composition in the form of an aqueous solution or dispersion based on polymeric organic material containing at least one organic polymeric material of a monomer, further polymer / copolymer or / and derivatives thereof and, if appropriate, at least one wax, of at least one water-soluble, water-containing and / or water-binding oxide or / and silicate, of at least one solid lubricant, of at least one coefficient of friction or / and of at least one further additive and a corresponding lubricant composition which is to serve after the formation of an LJ coating on a metallic molding, in particular the facilitation of the cold forming of this molding. A cold working can usually be carried out at surface temperatures of up to about 450 ⁰ C but without heat. The heating occurs only by the deformation and optionally the preheating of the workpieces to be formed. Typically, the temperature of the to be shaped workpieces, however, but is at about 20 ⁰ C. If the re-shaped workpieces at temperatures in the range 650-850 ⁰ C or 900-1250 ⁰ C in advance are heated, it is called warm or hot forming ,

While for the cold forming of metallic moldings at lower degrees of deformation and correspondingly lower forces usually forming oils are used, at much higher degrees of deformation usually at least one coating is used as a release layer between the workpiece and tool to avoid cold welding of the workpiece and tool. For the latter, it is customary to provide the workpieces with at least one coating of a lubricant or with a lubricant composition in order to reduce the frictional resistance between the workpiece and the lubricant. Surface and the U mform tool to reduce. The cold forming includes: a sliding pull (train pressure forming) eg of welded or seamless tubes, hollow profiles, bars, solid profiles or wires, a deep drawing and / or deep drawing eg of strips, sheets or hollow bodies to hollow bodies, a cold extrusion (pressure forming) eg of hollow or solid bodies and / or a cold dipping eg of wire sections to connecting elements such as nut or screw blanks.

Formerly, the cold-forming metal moldings have been made almost exclusively by either applying a grease, an oil, or an oil emulsion, or first by coating with zinc phosphate and then by coating either with a soap based on alkali or alkaline earth metal stearate or / and prepared with a solid lubricant in particular based on molybdenum sulfide, tungsten sulfide or / and carbon. However, a soap-containing coating will find its upper limit of use at medium and mid-high temperatures. A solid lubricant was only used if it was medium or heavy cold forming. In the cold forming of stainless steels, often coatings of chloroparaffins have been used which are today reluctantly used for reasons of environmental protection. But sulfide-containing coatings affect stainless steel.

Thereafter, it has occasionally begun to coat first with zinc phosphate and then either with oil or with a certain organic-polymeric composition. If required, either at least one solid lubricant such as, for example, molybdenum disulphide or / and graphite was added to the organic-polymeric composition (second coating, zinc phosphate being used as the first coating) or at least one solid lubricant was added as the third coating to the organic coating. applied polymeric coating. While molybdenum disulfide can be used up to temperatures of about 450 ⁰ C, graphite can be used up to temperatures of about 1100 ⁰ C, but its lubricating effect begins approximately at 600 ⁰ C. These coating sequences are still common today.

The application of a zinc phosphate layer and then a lubricant layer for cold forming is known in principle. Zinc phosphate, however, has the disadvantage of being less environmentally friendly due to the high zinc content and is often less favorable in terms of the quality of the coating and its composition. In the market, almost no organic polymeric materials for cold forming are known for cold forming and usually not suitable for heavy cold forming.

DE 102005023023 A1 teaches a method for the preparation of metallic workpieces for cold forming by electrolytic phosphating with an aqueous acidic phosphating solution based on Ca, MgO and / or Mn phosphate. This can be used to coat wires excellently. As a lubricant layer deposited thereon, compositions based on soaps are described. The soap layers are deposited from hot, strongly alkaline solutions and attack the metal phosphate layer so that metal soaps are formed. But the chemical conversion of Ca-phosphate to Ca-stearate, which promotes cold working, is slower and less complete than expected.

The lubricant systems based on metal soaps do not fulfill the meanwhile much more stringent demands on the degree of deformation, on the extrusion accuracy (net-shape) and the forming speed. In addition, environmental compatibility and workplace hygiene must be taken into account. Furthermore, the excess lubricant residues should not be deposited at one point on the tool. Because this influences the extrusion accuracy of the workpieces and increases rejects. It is advantageous if the coating and deposits can be easily removed from the workpiece, tool and equipment after forming.

The same cold-forming processes, compositions and coatings filed on the same day with the same patent office and applications based on which they are based, DE 102008000187.2, DE 102008000186.4 and DE 102008000185.6 are expressly incorporated herein, in particular also with regard to their substance groups, substances and their Contents, with respect to their examples and comparative examples and with respect to the respective process conditions.

Likewise, the compositions, processes and phosphate coatings of DE 102005023023 A1 and their corresponding applications of the same patent family are expressly incorporated into this application.

It was the task of proposing a two-stage coating process that allows the most environmentally friendly coating in a simple manner on phosphated metallic workpieces and is suitable in some embodiments, if necessary for medium and / or heavy cold forming. In a further object, the coating should be able to be removed in a simple manner if necessary after the cold forming of the formed workpiece.

The object is achieved with a method for the preparation of metallic workpieces for cold forming first by applying a phosphate layer and then by applying a lubricant layer with a substantial content of organic polymeric material, in which the phosphate layer with an aqueous acidic phosphating solution with a significant content of calcium, Magnesium or / and manganese and phosphate is formed and in which the lubricant layer (= coating) is formed by contacting the phosphated surface with an aqueous lubricant composition containing a content of organic polymer material based on ionomer and optionally also contains non-ionomer, and wherein as organic polymeric material predominantly monomers, oligomers, cooligomers, polymers or / and copolymers based on ionomer, acrylic acid / methacrylic acid, epoxide, ethylene, polyamide, propylene, styrene, urethane, at least one ionomer and / or at least one non-ionomer is at least partially saponified and / or at least partially present as at least one organic salt in the lubricant composition or / and in the coating.

The inventive method is used in particular to facilitate, improve or / and simplify the cold forming of metallic moldings.

Frequently, the metallic workpieces are pickled, degreased, cleaned, rinsed, e.g. mechanically descaled, sanded, peeled, brushed, blasted, or / and annealed by bending.

The phosphating solution is usually an aqueous solution. It may be a suspension in some embodiments, e.g. if it contains a content of precipitate or / and a Feinstpartikulären additive.

The concentrate, which is also a phosphating solution and with which the bath phosphating solution can be prepared, is in many cases by a factor in the range of 1.2 to 15, often by a factor in the range of 2 to 8, with the corresponding substances more enriched than the corresponding bath composition (the bath). The bath can be prepared from the concentrate by dilution with water and, if appropriate, also by adding at least one further additive such as, for example, sodium hydroxide solution and / or chlorate, which are preferably added individually to the bath for adaptation of the phosphating solution. Preferably, the phosphating solution contains no zinc or its cation content contains less than 60% by weight of the cations zinc, more preferably less than 50, less than 40, less than 30, less than 20, less than 10 or less than 5% by weight. -% of cations zinc. In some embodiments, the phosphating solution essentially contains only cations selected from calcium, magnesium and manganese. Levels of other heavy metal cations should then usually be less than 0.5 g / L, preferably less than 0.3 g / L or even less than 0.1 g / L.

The higher the zinc content and / or manganese content, the sooner the phosphating solution can be deposited without electricity. The higher the content of calcium and / or magnesium, the sooner an electrolytic phosphating is recommended. Preferably, with an alkaline earth content of the phosphating solution, more than 80% by weight of all cations are electrolytically phosphated.

Often the phosphating solution contains a low content of iron ions, in particular in the coating of workpieces made of iron or steel, or / and nickel ions - the latter in particular at zinc contents and preferably up to 0.8 g / L or to 0.5 g / L.

The phosphating solution according to the invention preferably contains calcium, magnesium or / and manganese ions, phosphoric acid and optionally also at least one further inorganic or / and organic acid such as nitric acid, acetic acid and / or citric acid. Preferably, the phosphating solution contains 1 to 200 g / L of compounds of calcium, magnesium or / and manganese including their ions, calculated as calcium, magnesium and manganese, which may be in particular as ions, more preferably 2 to 150 g / L, more particularly preferably 4 to 100 g / L, in particular 6 to 70 g / L, especially 10 to 40 g / L. In many embodiments, the phosphating solution contains phosphate as well as a) 5 to 65 g / L of Ca and 0 to 20 g / L of Mg or / and Mn or b) 5 to 50 g / L of Mg and 0 to 20 g / L of Ca or / and Mn or c) 5 to 80 g / L of Mn and 0 to 20 g / L of Ca or / and Mg. The content of the first cation can be determined in a), b) or c) are in particular in the range of 12 to 40 g / L. The content of the second and third cation in a), b) or c) may in particular have a content of 1 to 12 g / L for the second cation and a content of 0 or 0.1 to 8 g / L for the third cation , If the content of calcium, magnesium and manganese is too low, too little phosphate coating or even no phosphate coating can be formed. If the content of calcium, magnesium and manganese is too high, the coating quality of the phosphate coating may decrease. It can then come in particular to precipitation in the bathroom.

In addition, the phosphating solution may also contain other alkaline earth metals such as e.g. Strontium and / or barium, but especially ions of alkali metals, e.g. Sodium, potassium or / and ammonium especially for S-value adjustment and to improve the low temperature stability.

Preferably, the content of the phosphating solution of phosphate is calculated as PO ₄ in the range of 2 to 500 g / L as PO ₄ , in particular as phosphate ions, more preferably in the range of 4 to 320 g / L, most preferably in the range of 8 up to 200 g / L, in particular in the range of 12 to 120 g / L, especially in the range of 20 to 80 g / L. If the content of phosphate is too low, too little phosphate coating or even no phosphate coating can be formed. If the phosphate content is too high, it does not interfere or may decrease the coating quality of the phosphate coating. Under some conditions and too high a phosphate content, the phosphate coating may then become sponge-like porous and precipitate in the bath. Preferably, the phosphate content is slightly more than stoichiometric compared to the cation content.

Preferably, the content of the phosphating solution of nitrate is 0 or near 0 g / L or in the range of 1 to 600 g / L, in particular as nitrate ions, particularly preferably in the range from 4 to 450 g / L, very particularly preferably in the range from 8 to 300 g / L, in particular in the range from 16 to 200 g / L, especially in the range from 30 to 120 g / L. If the phosphating solution contains no or only little nitrate, this is more favorable for the wastewater. A low or moderate content of nitrate can have an accelerating effect on the phosphating and therefore be advantageous. Too low or too high a nitrate content of the phosphating solution has no significant influence on the phosphating and on the quality of the phosphate coating. Preferably, the total cation content in the form of nitrate (s) o / / and other, water-soluble salts is added, so that an addition of complexing agent (s) is not required.

The phosphating solution preferably comprises as accelerator at least one substance selected from substances based on chlorate, guanidine, hydroxylamine, nitrite, nitrobenzenesulfonate, perborate, peroxide, peroxysulfuric acid and other nitro-group-containing accelerators. Preferably, the content of the phosphating solution on accelerators other than nitrate, e.g. based on nitrobenzenesulfonate (e.g., SNBS = sodium nitrobenzenesulfonate), chlorate, hydroxylamine, nitrite, guanidine, e.g. Nitroguanidine, perborate, peroxide, peroxy- sulfuric acid and other nitrogen containing accelerators zero, near zero or in the range of 0.1 to 100 g / L, as compounds and / or ions, calculated as the corresponding anion. The content of the phosphating solution at accelerators other than nitrate is particularly preferably in the range from 0.01 to 150 g / l, very particularly preferably in the range from 0.1 to 100 g / l, in particular in the range from 0.3 to 70 g / l , especially in the range of 0.5 to 35 g / L.

Preferably, the content of the phosphating solution is based on guanidine such as nitroguanidine zero, near zero or in the range of 0.1 to 10 g / L calculated as nitroguanidine, more preferably 0.2 to 8 g / L, most preferably in Range from 0.3 to 6 g / L, especially in the range of 0.5 to 3 g / L. A guanidine compound such as Nitrogua In comparison with other accelerators and nitrate, nidine can have a strongly accelerating content based on its content, but does not give off any oxygen and often leads to fine-grained and particularly adherent phosphate coatings. In addition, it may also contain an addition of at least one other phosphorus-containing compound, in particular in each case at least one condensed phosphate, pyrophosphate and / or phosphonate.

The phosphating solution preferably contains the following contents: 4 to 100 g / L of Ca, Mg or / and Mn, optionally a zinc content of up to 60% by weight of all cations, 0 or 0.01 to 40 g / L of alkali metal (s) or / and NH ₄ , 5 to 180 g / L PO ₄ , 3 to 320 g / L of nitrate and / or accelerator (s) and 0 or 0.01 to 80 g / L of complexing agent (s).

The phosphating solution particularly preferably contains the following contents: 5 to 60 g / L of Ca, Mg or / and Mn, optionally a zinc content of up to 60% by weight of all cations, 0 or 0.01 to 25 g / L of alkali metal (s) and / or NH ₄ , 8 to 100 g / L PO ₄ , 5 to 240 g / L of nitrate and / or accelerator (s) and 0 or 0.01 to 50 g / L of complexing agent (s).

Most preferably, the phosphating solution contains the following contents: 8 to 50 g / L of Ca, Mg or / and Mn, optionally a zinc content of up to 60% by weight of all cations, 0 or 0.01 to 20 g / L of alkali metal (s ) o- and / or NH ₄ , 12 to 80 g / L PO ₄ , 12 to 210 g / L of nitrate and / or accelerators) and 0 or 0.01 to 40 g / L of complexing agent (s).

In particular, the phosphating solution contains the following contents: 10 to 40 g / L of Ca, Mg or / and Mn, optionally a zinc content of up to 60% by weight of all cations, 0 or 0.01 to 15 g / L of alkali metal (s) or / and NH ₄ , 16 to 65 g / L PO ₄ , 18 to 180 g / L of nitrate and / or accelerator (s) and 0 or 0.01 to 32 g / L of complexing agent (s). The value of the total acid of a phosphating solution is preferably in the range of 30 to 120 points, especially 70 to 100 points. The value of the total acid Fischer is preferably in the range of 8 to 60 points, especially at 35 to 55 points. The value of the free acid is preferably 2 to 40 points, especially 4 to 20 points. The ratio of the free acid to the value of the total acid Fischer, ie the quotient of the contents of free and bound phosphoric acid, calculated as P ₂ O ₅ , the so-called S value, is preferably in the range of 0.15 to 0.6, particularly preferred in the range of 0.2 to 0.4.

For the S-value adjustment, e.g. an addition of at least one basic substance, e.g. NaOH, KOH, an amine or ammonia, in particular in the form of an aqueous solution, to the phosphating solution.

The total acid score is determined by titrating 10 ml of the phosphating solution after diluting with water to about 50 ml using phenolphthalein as an indicator until the color changes from colorless to red. The number of ml of 0.1 N sodium hydroxide solution consumed for this gives the total acid score. Other indicators suitable for titration are thymolphthalein and ortho-cresolphthalein.

Correspondingly, the free acid score of a phosphating solution is determined using dimethyl yellow as an indicator and titrating to pink from yellow to yellow.

The S value is defined as the ratio of free P ₂ O ₅ to the total content of P ₂ O ₅ and can be determined as the ratio of the free acid score to the Fischer total acid score. The total acid Fischer is determined by using the titrated sample of the titration of the free acid and adding to it 25 ml of 30% potassium oxalate solution and about 15 drops of phenolphthalein, setting the titrator to zero, giving the score of the free Acid is subtracted, and to Cover is titrated from yellow to red. The number of ml of 0.1 N sodium hydroxide solution consumed for this gives the score of the total acid Fischer.

The application temperature of the phosphating solution is preferably about room temperature or in particular in the range of 10 ⁰ C to 95 ⁰ C. Particularly preferred is a temperature range of 15 to 40 ⁰ C. In electrolytic phosphating the application temperature of the phosphating solution is preferably in the range of 10 to 60 ^0th C, especially at 15 to 40 ⁰ C.

The treatment time is - in continuous process optionally for the respective product section of a long product - preferably 0.1 to 180 s, more preferably 1 to 20 or 2 to 10 s in particular for wires or 5 to 100 s for larger compared to a wire workpieces such as for slugs and / or rods. In continuous systems, the treatment time can be particularly advantageously in the range of 0.5 to 10 s, in particular 1 to 5 s. In some embodiments, the adhesion of the phosphate layer electrolytically generated in continuous flow systems on the metallic substrate decreases a little when the treatment time is less than 1 second and more than 10 seconds. The phosphate layers deposited in continuous systems were designed so that the adhesion of the polymeric organic coating according to the invention to the phosphate layer was largely independent of the treatment time during electrolytic phosphating. There were no differences in quality over the variation of the treatment time from 1 to 10 s. For large workpieces, especially for long or endless, the contact is suitable for a Fakirbett on which the workpiece can rest on individual points and thereby be electrically contacted. When diving in particular larger and / or longer metallic workpieces, the treatment time can often be 0.5 to 12 min, in particular 5 to 10 min. The current intensity depends on the size of the metallic surface (s) to be coated and is often in the range of 100 to 1000 A eg for each individual wire in a continuous line and often in the range of 0.1 to 100 A for each individual slug or rod , ie usually in the range of 1 to 1000 A per component.

The voltage automatically results from the applied current or current density. The current density is-largely independent of the proportions of direct current and / or alternating current-preferably in the range of 1 and 200 A / dm ² , more preferably in the range of 5 to 150, 8 to 120, 10 to 100, 12 to 80, 14 to 60, 16 to 40, 18 to 30 or 20 to 25 A / dm ² . The voltage is often - depending in particular on the size of the system and the type of contacts - in the range of 0.1 to 50 V, in particular in the range of 1 to 40 V, 2.5 to 30, 5 to 20 or 7 to 12 V. The coating times during electrolytic phosphating can be in particular in the range from 0.1 to 60, 0.5 to 50, 1 to 40, 2 to 30, 3 to 25, 4 to 20, 5 to 15 or 8 to 12 s lie.

It has surprisingly been found that it can be particularly advantageous for the increase in production to work with short or particularly short coating times if the current density and the voltage are selected to be correspondingly higher. Here, working with 0.2 to 2 s is very possible. Essentially the same good layer results as when working with lower current densities and with lower voltages resulted in somewhat longer coating times. However, at slightly higher levels of zinc in the phosphating solution, care should be taken to ensure that no metallic zinc is deposited at high current densities and high voltages. The higher the zinc content, the current density and the stress, the higher the probability of depositing metallic zinc, which usually interferes with cold forming. As the electrolytic phosphating current, a direct current or an alternating current or a superposition of a direct current and an alternating current can be used for this purpose. Preferably, the electrolytic phosphating is carried out with direct current or with a superposition of direct current and alternating current. The direct current may preferably have an amplitude (= current density) in the range of 1 and 200 A / dm ² , particularly preferably in the range of 5 to 150, 8 to 120, 10 to 100, 12 to 80, 14 to 60, 16 to 40, 18 to 30 or 20 to 25 A / dm ² have. The alternating current may preferably have a frequency in the range of 0.1 to 100 Hz, more preferably in the range of 0.5 to 10 Hz. The alternating current may preferably have an amplitude in the range of 0.5 to 30 A / dm ² , more preferably in the range of 1 to 20 A / dm ² , most preferably in the range of 1, 5 to 15 A / dm ² , in particular in the range of 2 to 8 A / dm ² .

With a superposition of direct current and alternating current, the electrical conditions just mentioned can be combined. With a superimposition of direct current and alternating current, the ratio of direct current component to alternating current component as the aforementioned electrical conditions can be varied within wide limits. The ratio of the DC component to the AC component is preferably maintained in the range from 20: 1 to 1:10, particularly preferably in the range from 12: 1 to 1: 4, very particularly preferably in the range from 8: 1 to 1: 2 all in the range of 6: 1 to 1: 1, based on the proportions measured in A / dm ² .

The substrate to be coated is connected as a cathode. However, if the substrate to be coated is switched as an anode, there may be. only a bake effect, but may not form a well-visible coating.

The phosphate coatings produced according to the invention often show under a scanning electron microscope-unlike chemically comparable ones, electrolessly deposited phosphate coatings - not the typical crystal forms, but on the one hand particle-like structures that are often open in the middle similar short tube sections and look as if they had been formed around a fine hydrogen bubble around. These particles often have an average particle size in the range of 1 to 8 μm. This has made it possible to make the hydrogen bubbles finer by addition of a specific accelerator such as nitroguanidine, on the other hand by adding a reducing agent such as based on an inorganic or organic acid, their salts and / or esters to avoid altogether, so that the phosphate coatings not too particulate. It is particularly preferred to add to the phosphating solution a reducing agent, preferably in the range of 0.1 to 15 g / L, which forms no sparingly soluble compounds in the pH range between 1 and 3 with calcium, magnesium or / and manganese, around the morphology to influence the phosphate coating, in particular to uniform. In the case of phosphate coatings of insufficient homogeneity, which are insufficiently closed, in some cases distinct differences in the formation of the phosphate coating in different areas of the sample can be seen. Therefore, all phosphate coatings according to the invention differ significantly from electrolessly deposited phosphate coatings.

As a major component of the calcium-rich, electrodeposited phosphate coatings, brushite CaHPO ₄ , but surprisingly not a tricalcium phosphate, was detected by X-ray diffraction. In the experiments, similar calcium-rich phosphating solutions gave no electroless coating at all. The main constituent of the magnesium-rich electrolytically produced phosphate coatings appears to be X-ray amorphous unlike electroless phosphate coatings. The main constituent of the manganese-rich electrolytically produced phosphate coatings appears to be MnHPO ₄ -3H ₂ O. The coating weights of the phosphate coatings obtained for a wire are preferably in the range of 1 and 25 g / m ² , in particular in the range of 2 to 15 or from 3 to 10 g / m ² , and for a larger compared to a wire metallic substrate in Range of 2 and 60 g / m ² . In electrolytic phosphating, the coating weight is a function of the current density and the treatment time. The phosphate coating often has a thickness in the range of 0.5 to 40 microns, often in the range of 1 to 30 microns.

Liquid lubricants or lubricant compositions may e.g. be applied by dipping in a bath on the workpieces. Powder-shaped or pasty lubricants or lubricant compositions are preferably initially introduced in a die set, through which e.g. a wire can be pulled while being coated.

In some embodiments, the phosphating solution is preferably free or substantially borate free or, in addition to a comparatively small borate content, also has a comparatively high phosphate content. Preferably, an alkaline earth metal-containing phosphating solution is free of fluoride and complex fluoride.

The term "lubricant composition" denotes the stages from the aqueous over the drying to the dry lubricant composition as the chemical composition, phases related composition and composition relating to mass, while the term "coating" refers to the dry, heated, softening and / or melting coating is formed from the lubricant composition and / or formed, including its chemical composition, phase-related composition and composition referred to composition. The aqueous lubricant composition may be a dispersion or solution, especially a solution, colloidal solution, emulsion and / or suspension. she usually has a pH in the range from 7 to 14, in particular from 7.5 to 12.5 or from 8 to 11, 5, particularly preferably from 8.5 to 10.5 or from 9 to 10.

The lubricant composition and / or the coating formed therefrom preferably contain / contains at least one water-soluble, water-containing or / and water-binding oxide and / or silicate content and at least one ionomer, at least one non-ionomer and / or at least one wax, and / or optionally a content of at least one additive. In some embodiments, it additionally particularly preferably contains in each case at least one content of acrylic acid / methacrylic acid or / and styrene, in particular as polymer (s) or copolymer (s), which is / are no ionomer (s). Preferably, the lubricant composition and / or the coating formed therefrom each contain / contain at least 5% by weight of at least one ionomer and / or non-ionomer.

The organic polymeric material preferably consists essentially of monomers, oligomers, cooligomers, polymers or / and copolymers based on ionomer, acrylic acid / methacrylic acid, epoxide, ethylene, polyamine, propylene, styrene, urethane, their ester (s) or / and their salt (s). The term "ionomer" here includes a content of free and / or associated ions.

Oxides or / and silicates:

Surprisingly, it was found that even with a very small addition of water-soluble, hydrous and / or water-binding oxide or / and silicate such as water glass to a substantially organic polymeric composition in several embodiments, a significant improvement in cold working under otherwise identical conditions is achieved and stronger can be reformed than comparable lubricant compositions free of these compounds. on the other hand It was found that also workpieces with a coating with a very high content of water-soluble, hydrous or / and water-binding oxide or / and silicate in an otherwise substantially organic polymer composition can also be converted very advantageously. For some embodiments, an optimum has rather resulted in the lower or / and middle composition range.

In tests over a broader product spectrum, it has been found that the lubricant compositions and / or coatings containing water-soluble, hydrous or / and water-binding oxide or / and silicate, such as e.g. Water glass to a much greater extent than previously on the one hand to an additional solid lubricant layer based on sulfide lubricant such. Molybdenum disulfide, on the other hand can be dispensed with a third coating based on sulfide solid lubricant. In the first case, this solid lubricant layer is the second coating, in the second case the third coating, which follows a zinc phosphate layer as the first coating. The ability to partially dispense with the use of solid lubricant, not only a significant labor and cost savings and simplification is, but also saves at least one expensive, environmentally unfriendly, strongly blackening and disturbing with respect to the pollution and corrosion sensitivity substance.

Whereas this product range used to be coated with soap for about 60% of the product spectrum and molybdenum disulphide and possibly graphite as the second layer for a zinc phosphate layer in the remaining approximately 40% of the product spectrum, this product spectrum would today be treated first with a zinc phosphate layer, then with a conventional organic-polymeric lubricant composition and optionally additionally, if necessary, additionally coated with a third coating based on sulfidic solid lubricant and optionally additionally of graphite. Sulphide solid lubricant was common to all telschweren and heavy Kaltumformungen necessary. Since the soap layer did not allow precise cold forming - that is, no high extrusion accuracy of the formed workpieces - the organic-polymeric lubricant composition, which is significantly higher in quality than the soap coating, was isolated despite the higher cost. However, it was free of water-soluble, hydrous and / or water-binding oxides or / and silicates. In this sequence, about 40% of the product spectrum would require the additional third coating. When using a zinc phosphate layer as the first coating and the lubricant composition according to the invention as the second coating, an additional third coating based on sulfidic solid lubricant is now required only at 12 to 20% of the product spectrum.

The water-soluble, water-containing or / and water-binding oxide or / and silicate may preferably each comprise at least one water glass, a silica gel, a silica sol, a silica hydrosol, a silicic acid ester, an ethyl silicate and / or at least one of their precipitated products, hydrolysis products, condensation products or / and reaction products, in particular a lithium, sodium or / and potassium-containing water glass. Preferably, a content of water in the range of 5 to 85 wt .-% based on the content of solids bound or / and coupled to the water-soluble, hydrous and / or water-binding oxide o- / silicate and / or coupled, preferably in the range of 10 to 75, from 15 to 70, from 20 to 65, from 30 to 60 or from 40 to 50 wt .-%, wherein the typical water content may have significantly different water contents depending on the nature of the oxide or / and silicate. The water may for example be bound to the solid or / and coupled due to the solubility, adsorption, wetting, chemical bonding, porosity, complex particle shape, complex aggregate form and / or intermediate layers. These water-bound or / and coupled substances apparently act in the lubricant composition or / and in the coating in a manner similar to a sliding layer. It can also be a mixed from two or from at least three substances of this group are used. In addition to or instead of sodium or / and potassium, other cations may be present, in particular ammonium ions, alkali ions other than sodium and / or potassium ions, alkaline earth metal ions and / or transition metal ions. The ions may be or have been at least partially replaced. The water of the water-soluble, aqueous o- / / and water-binding oxide and / or silicate can be at least partially adsorbed as water of crystallization, as a solvent, bound to pore space, in a dispersion, in an emulsion, in a gel and / or in a sol available. Particularly preferred is at least one water glass, in particular a sodium-containing water glass. Alternatively or additionally, it may also contain a content of at least one oxide such as, in each case, at least one silicon dioxide or / and magnesium oxide and / or at least one silicate, for example at least one layered silicate, modified silicate and / or alkaline earth silicate. Preferably, this is in each case at least one oxide or / and silicate in dissolved form, in nanocrystalline form, as gel and / or as sol. Optionally, a solution may also be present as a colloidal solution. If the water-soluble, water-containing or / and water-binding oxide or / and silicate is present in particulate form, it is preferably very fine-grained, in particular with an average particle size of less than 0.5 μm, less than 0.1 or even less than 0.03 μm, respectively determined with a laser particle measuring device and / or nanoparticle measuring device.

The water-soluble, hydrous or / and water-binding oxides or silicates, in many embodiments, help to increase the viscosity of the dried, emollient and melting coating and are widely used as binders, as hydrophobing agents and as corrosion inhibitors. It has been found that among the water-soluble, water-containing or / and water-binding oxides or / and silicates, water glass behaves particularly favorably. By adding, for example, 2 to 5% by weight of waterglass - based on solids and active substances - to the serigen Schmierstoffzusannnnensetzung the viscosity of the dried, softening and melting the coating in many embodiments is particularly raised significantly at temperatures higher than 230 ⁰ C as compared to a lubricating composition on the same chemical base view, but without the water glass additive. As a result, a higher mechanical stress during cold forming is possible. This made it possible for many compositions and applications only to apply a cold extrusion, which was not applicable without this addition. The tool wear and the number of tool changes can be drastically reduced. The production costs are thereby also significantly reduced.

It has been found that the tool becomes cleaner and brighter as the proportion of water glass in the lubricant composition increases, all other working conditions being the same and the same basic composition. On the other hand, it was also possible to increase the content of water glass in the lubricant composition up to about 85 wt .-% of solids and active ingredients and still achieve good to very good results. At levels of more than 80 wt .-% of solids and active ingredients, the wear increases significantly. An optimum obviously lies somewhere in the lower or / and middle salary range, since with very high contents also the tool wear increases again slowly. When added on the basis of titanium dioxide or titanium oxide sulfate a slightly stronger wear than in a water glass addition was found, although the addition has proven fundamentally. A disilicate additive has also proved to be advantageous.

The content of water-soluble, hydrous or / and water-binding oxides or / and silicates in the lubricant composition and / or in the coating formed therefrom is preferably 0.1 to 85, 0.3 to 80 or 0.5 to 75 wt .-% of the solid - And active ingredients, more preferably 1 to 72, 5 to 70, 10 to 68, 15 to 65, 20 to 62, 25 to 60, 30 to 58, 35 to 55 or 40 to 52 wt .-% of the solids and active ingredients , determined without the bound those and / or coupled water content. The weight ratio of the contents of water-soluble, hydrous or / and water-binding oxides or / and silicates to the content of ionomer (s) and / or non-ionomer (s) in the lubricant composition or / and in the coating is preferably in the range of 0.001: From 1 to 0.2: 1, more preferably in the range of from 0.003: 1 to 0.15: 1, from 0.006: 1 to 0.1: 1, or from 0.01: 1 to 0.02: 1.

ionomers:

The ionomers are a particular type of polyelectrolyte. They preferably consist essentially of ionomeric copolymers, optionally together with corresponding ions, monomers, comonomers, oligomers, cooligomers, polymers, their esters or / and their salts. Block copolymers and graft copolymers are considered to be a subgroup of the copolymers. Preferably, the ionomers are compounds based on acrylic acid / methacrylic acid, ethylene, propylene, styrene, their esters or their salt (s) or mixtures with at least one of these ionomeric compounds. The lubricant composition and / or the coating formed therefrom may either contain no content or content of at least one ionomer in the range of from 3 to 98% by weight of the solids and active ingredients. Preferably, the content of at least one ionomer is from 5 to 95, 10 to 90, 15 to 85, 20 to 80, 25 to 75, 30 to 70, 35 to 65, 40 to 60 or 45 to 55 wt .-% of the solid and active ingredients of the lubricant composition and / or the coating formed therefrom. Depending on the desired range of properties and the application of certain workpieces to be reshaped and cold forming operations, the composition of the lubricant composition and / or the coating formed therefrom may vary and vary widely.

The lubricant composition and / or the coating formed therefrom may preferably comprise at least one ionomer having a substantial content of at least one copolymer, in particular a copolymer based on polyacrylic, polymethacrylic, polyethylene or / and polypropylene. If appropriate, an ionomer has a glass transition temperature T ₉ in the range from - 30 ⁰ C to +40 ⁰ C, preferably in the range of - 20 to + 20 ⁰ C. The molecular weight of the ionomer is preferably in the range of 2,000 to 15,000, particularly preferably in the range of 3,000 to 12,000 or from 4,000 to 10,000. The lubricant composition or / and the coating formed therefrom particularly preferably contains / contains at least one ionomer based on ethylene acrylate and / or ethylene methacrylate, preferably one having a molecular weight in the range from 3,500 to 10,500, more preferably in the range from 5,000 to 9,500 / and with a glass transition temperature T ₉ in the range of - 20 ⁰ C to + 30 ⁰ C. In at least one ionomer based on ethylene acrylate and / or ethylene methacrylate, the acrylate content may be up to about 25 wt .-%. A slightly higher molecular weight may be advantageous for higher-loadable coatings. For there were tendencies that indicate a higher molecular weight of the ionomer and that a higher viscosity of the composition in the temperature range of about 100 ⁰ C to the order of about 300, 350 or 400 ⁰ C on the mechanical strength of the hereby produced Coatings and allows for heavier cold forming. If appropriate, crosslinking of the ionomer, for example with at least one amine, carbonate, epoxide, hydroxide, oxide, surfactant or / and with at least one carboxyl-containing compound, can in particular be used during drying and / or during cold forming. The higher the proportion of the ionomer in the lubricant composition or / and in the coating, the heavier cold formations are possible in many embodiments. Some ionomer additives also serve to ensure lubrication and reduce friction in the early stages of cold forming, especially when the workpiece is cold and the tool is cold. This is all the more important the easier and / or weaker the cold forming is and the lower the forming temperature is. The melting point of at least one ionomer is in many embodiments preferably in the range of 30 to 85 ⁰ C. Its glass transition temperature is preferably below 35 ⁰ C. At least one ionomer is preferably added as a dispersion.

Non-ionomers:

Moreover, in the lubricant composition and / or in the coating formed therefrom, in particular in the polymeric organic material, further organic polymeric constituents may be present, e.g. Oligomers, polymers or / and copolymers based on acrylic acid / methacryic acid, amide, amine, aramid, epoxide, ethylene, imide, polyester, propylene, styrene, urethane, their ester (s) or / and their salts These include, for example, polymers / copolymers based on acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, wholly aromatic polyamides, wholly aromatic polyesters, wholly aromatic polyimides and / or Styrene acrylates, block copolymers and graft copolymers are considered as a subset of the copolymers.

Depending on the embodiment, they serve to increase the viscosity at elevated temperature, as lubricants, as high-temperature lubricants, to increase the viscosity, in particular in the temperature range from 100 to 250, from 100 to 325 or even from 100 to 400 ^° C., as substances resistant to high temperatures with waxy properties, as thickener (= viscosity regulators), as additives, to achieve additional softening ranges / softening points or / and melting ranges / melting points or / and for the design of the lubricant composition with several softening ranges / softening points o / / and melting ranges / melting points in certain temperature intervals. Among others, some acrylic-containing polymers / copolymers and some styrene acrylates may act as thickeners. Polyethylene or polypropylene may preferably be modified by propylene, ethylene, their corresponding polymers or / and by further additives such as acrylate. They may preferably have waxy properties. They may preferably have at least one softening range / softening point or / and at least one melting range / melting point in the range from 80 to 250 ^° C.

The polymers or / and copolymers of these substances preferably have a molecular weight in the range of 1,000 to 500,000. Individual substances preferably have a molecular weight in the range of 1,000 to 30,000, others one in the range of 25,000 to 180,000 or / and in the range of 150,000 to 350,000. Particularly high molecular weight substances can be used as thickeners. An acrylic or / and a styrene-acrylate additive can also have a thickening effect. In some embodiments, one or two, three, four or five different non-ionomers are added to the ionomer-containing lubricant composition and / or the coating. The lubricant composition and / or the coating formed therefrom preferably does not have a content or content of at least one non-ionomer in the range of 0.1 to 90% by weight of the solids and the active ingredients. The content of the at least one non-ionomer is particularly preferably 0.5 to 80, 1 to 65, 3 to 50, 5 to 40, 8 to 30, 12 to 25 or 15 to 20 wt .-% of the solids and active ingredients the lubricant composition or the coating.

Both the individual or premixed ionomers, as well as the individual or premixed non-ionomers, may each be added, independently of each other, as a solution, colloidal solution, dispersion, and / or emulsion of the aqueous lubricant composition.

The lubricant composition particularly preferably contains as non-ionomers, which are not waxes in the context of this application: a) from 0.1 to 50% by weight and in particular from 5 to 30% by weight essentially of waxy polyethylene or / and of waxy polypropylene, each having at least one softening point / softening point or / and melting point / melting point above 120 ^° C.,

b) 0.1 to 16 wt .-% and in particular 3 to 8 wt .-% substantially of polyacrylate having a molecular weight in the range of 4,000 to

1,500,000 - more preferably in the range of 400,000 to 1,200,000 - or / and

c) 0.1 to 18 wt .-% and in particular 2 to 8 wt .-% polymer / copolymer based on styrene, acrylic acid and / or methacrylic acid having a molecular weight in the range of 120,000 to 400,000 or / and with a glass transition point T ₉ in the range of 30 to 80 ⁰ C.

The ionomers and / or non-ionomers may be present at least partially, in particular the acrylic acid components of the polymers according to b) and c), preferably partially under application conditions, in particular for the most part or completely, as salts of inorganic or / and organic cations. If non-ionomer is also included in the lubricant composition, the weight ratio of the contents of ionomer (s) to non-ionomer (s) is preferably in the range of 1: 3 to 50: 1, more preferably in the range of 1: 1 to 35 : 1, from 2: 1 to 25: 1, from 4: 1 to 18: 1 or from 8: 1 to 12: 1.

The lubricant composition and / or the coating made therewith have a total content of at least one ionomer and / or non-ionomer, preferably from zero or in the range from 3 to 99% by weight of the solids and active ingredients. This content is particularly preferably 10 to 97, 20 to 94, 25 to 90, 30 to 85, 35 to 80, 40 to 75, 45 to 70, 50 to 65 or 55 to 60 wt .-% of the solids and active ingredients of Lubricant composition and / or coating. Thickener based on Non-ionomers are included here. Depending on the intended conditions of use and cold forming operations and the design of the lubricant composition and / or the coating, the content of ionomer (s) or / and non-ionomer (s) can vary within wide limits. At least one content of at least one ionomer is particularly preferred.

Preferably, the entire organic polymeric material - this term is intended to include ionomer (s) or / and non-ionomer (s) but not waxes - has an average acid number in the range of from 20 to 300, more preferably in the range of from 30 to 250 40 to 200, from 50 to 160 or from 60 to 100. The term "all organic polymeric material" is intended to include ionomer (s) and / or non-ionomer (s) but not waxes.

Neutralization agent:

It is particularly advantageous if at least one ionomer and / or at least one non-ionomer is at least partially neutralized, at least partially saponified and / or at least partially present as at least one organic salt in the lubricant composition and / or in the coating. The term "neutralization" here means the at least partial reaction of at least one organic polymeric substance having a content of carboxyl groups, that is to say in particular of at least one ionomer or / and at least one non-ionomer, with a basic compound (= neutralizing agent), If at least one ester is reacted in this case, saponification may be used, For the neutralization of the lubricant composition, the neutralizing agent used is preferably at least one primary, secondary or tertiary amine, Ammonia or / and at least one hydroxide is used - for example ammonium hydroxide, at least one alkali hydroxide such as, for example, lithium, sodium and / or potassium hydroxide or / and at least one alkaline earth metal hydroxide, particularly preferably an addition of at least one alkylamine, at least one aminal alcohol or / and at least one amine related thereto, for example in each case at least one alkanolamine, an aminoethanol, an aminopropanol, a diglycolamine, an ethanolamine, an ethylenediamine, a monoethanolamine, a diethanolamine or / and a triethanolamine lamin, in particular dimethylethanolamine, 1- (dimethylamino) -2-propanol or / and 2-amino-2-methyl-1-propanol (AMP). The at least one organic salt, in particular at least one salt of inorganic or / and organic cations such as ammonium ions, can be obtained, for example, by adding at least one neutralizing agent to at least one ionomer and / or at least one non-ionomer or / and to a mixture containing at least one these polymeric organic materials and optionally at least one further component such as at least one wax and / or at least one additive contains, are formed. The salt formation can take place before or / and in the preparation of the lubricant composition or / and in the lubricant composition. The neutralizing agent, in particular at least one amine alcohol, forms many times in the temperature range from room temperature to about 100 ⁰ C, in particular at temperatures in the range of 40 to 95 ⁰ C, with at least one ionomer and / or with at least one non-ionomer corresponding salts. It is believed that in some embodiments, in particular at least one amine alcohol, the neutralizing agent may chemically react with the water-soluble, hydrous and / or water-binding oxide and / or silicate and thereby form a reaction product that beneficially behaves for cold working.

It has proved advantageous in several embodiments, at least one amine, in particular at least one amino alcohol, a single ionomer, a single non-ionomer, a mixture containing at least one ionomer or / and a mixture containing at least one non-ionomer in advance in the preparation to the aqueous lubricant composition. The previous addition is often beneficial to allow reactions to organic salts. The amines rea- As a rule, any organic polymeric material which contains carboxyl groups tends to be greedy as long as the temperatures for the reactions are sufficiently high. These reactions are preferably carried out at or above the temperatures of the melting point / melting range of the corresponding polymeric compounds. When the temperature is below the

Melting point / melting range of the corresponding polymeric compounds remains, will often be no conversion to an organic salt. This will then not facilitate the cleaning of the formed workpiece. As an alternative then remain only the possibilities to implement the corresponding polymeric compounds separately and consuming at high pressure and elevated temperature and / or already added such substances of the lubricant composition. Aqueous lubricant compositions with an addition of ammonia should preferably not be heated above 30 ⁰ C. Aqueous lubricant compositions with an addition of at least one amine should preferably be kept in a temperature range of 60 to 95 ⁰ C, in which many reactions take place to amine salts.

The addition of at least one neutralizing agent, such as at least one amine or / and at least one amine alcohol, helps to make the organic polymeric material more water soluble and / or better water dispersible. The reactions to corresponding salts preferably proceed with water-soluble or / and water-dispersed organic polymeric materials. It is particularly preferred that the at least one neutralizing agent, in particular at least one amine, is added early in the mixing together of the various components of the aqueous lubricant composition and thereby optionally at least one already contained organic polymeric material and / or at least one subsequently added organic polymeric material is at least partially neutralized. Preferably, the neutralizing agent is added in excess or / and is contained in the lubricant composition and / or in the coating in excess.

The at least one neutralizing agent, in particular the at least one amine alcohol, can also be used to adjust the pH of a mixture or of the aqueous lubricant composition.

The organic salts have the advantage over ionomers and / or non-ionomers of being often more water-soluble or better water-dispersible than the corresponding ionomers and / or non-ionomers. As a result, the coatings and deposits from cold forming can be better removed from the formed workpiece. Frequently, organic softening results in lower softening ranges / softening points and / or lower melting ratios / melting points, which is often advantageous. Optionally, better lubricating properties also result for the desired processing conditions.

As organic salts, especially amine salts and / or organic ammonium salts are preferred. Very particular preference is given to amine salts since, after application of the aqueous lubricant composition, they do not change their composition more strongly and have higher water solubility and / or water dispersibility and therefore help to relatively easily remove the coating and the deposits on the formed workpiece after cold working. In the case of the organic ammonium salts, on the other hand, ammonia rapidly escapes after the application of the aqueous lubricant composition, which not only can be an odor nuisance, but also causes a back reaction of the ammonium salts to the original organic polymeric substances, which can then later be removed worse than the amine salts. This results in chemically and in water quite stable over- Trains. The use of hydroxide (s) as a neutralizing agent often results in fairly hard and brittle, but water-sensitive coatings.

The content of the at least one neutralizing agent, in particular also the at least one Aminalkohols, in the lubricant composition may - especially depending on the acid number of the ionomer or non-ionomer - at the beginning of the neutralization reaction preferably at zero or in the range of 0.05 to 15, from 0 , 2 to 12, from 0.5 to 10, from 0.8 to 8, from 1 to 6, from 1, 5 to 4 or from 2 to 3 wt .-% of the solids and active ingredients. Higher contents may be advantageous in some embodiments, in particular with the addition of at least one amine, while in the case of an addition of ammonia or / and at least one hydroxide in most embodiments rather lower contents are selected. The weight ratio of the contents of neutralizing agent (s), in particular also of amino alcohol (s), to contents of ionomer (s) or / and non-ionomer (s) or / and to the total content of organic polymeric material is preferably in the range Range from 0.001: 1 to 0.2: 1, more preferably in the range of 0.003: 1 to 0.15: 1, from 0.006: 1 to 0.1: 1, or from 0.01: 1 to 0.05: 1 ,

The lubricant composition of the present invention and / or the coating formed therefrom preferably does not have a content or content of at least one organic salt, preferably formed by neutralization, in the range of 0.1 to 95 or 1 to 90% by weight of the solid and active ingredients. Preferably, the content of at least one salt is 3 to 85, 8 to 80, 12 to 75, 20 to 70, 25 to 65, 30 to 60, 35 to 55 or 40 to 50 wt .-% of the solids and active ingredients of the lubricant composition , The weight ratio of the contents of at least one organic salt to contents of ionomer (s) or / and non-ionomer (s) in the lubricant composition or / and in the coating is preferably in the range from 0.01: 1 to 100: 1, particularly preferred In the range of 0.1: 1 to 95: 1, from 1: 1 to 90: 1, from 2: 1 to 80: 1, from 3: 1 to 60: 1, from 5: 1 to 40: 1 or from 8: 1 to 20: 1.

waxes:

According to the definition used in this application, a wax is intended to mean a compound which has a defined melting point, which in the molten state has a fairly low viscosity and which is capable of occurring in crystalline form. Typically, a wax has no or no substantial content of carboxyl groups, is hydrophobic, and is highly chemically inert.

The lubricant composition and / or the coating formed therefrom may preferably contain at least one wax, in particular at least one paraffin wax, a carnauba wax, a silicone wax, an amide wax, an ethylene and / or a propylene-based wax and / or a crystalline wax. In particular, it can serve to increase the lubricity and / or creep of the forming and / or formed coating, the separation of the workpiece and the tool and to reduce friction. Preferably, no wax or a content of at least one wax in the range of 0.05 to 60 wt .-% of the solids and active ingredients in the lubricant composition and / or in the coating contained, more preferably and in particular depending on the conditions of use and total chemical composition, for example in the range of 0.5 to 52, 1 to 40, 2 to 35, 3 to 30, 4 to 25, 5 to 20, 6 to 15, 7 to 12 or 8 to 10 wt .-% of the solids and active ingredients. Preferably, the content of the individual wax is in each case in the range from 0.05 to 36% by weight of the solids and active substances in the lubricant composition or / and in the coating, particularly preferably in the range from 0.5 to 30, 1 to 25 , 2 to 20, 3 to 16, 4 to 12, 5 to 10 or 6 to 8 wt .-% of the solids and active ingredients.

At least one wax may preferably have an average particle size in the range of 0.01 to 15 microns, more preferably in the range of 0.03 to 8 μm or 0.1 to 4 μm. With these particle sizes, it may be preferred in many embodiments if the wax particles at least partially protrude from the formed coating.

The addition of at least one wax may be dispensed with, in particular if the cold working is not too heavy and / or if a higher content of ionomer, waxy substance or / and water-soluble, hydrous and / or water-binding oxide and / or silicate is included. Only with heavy cold extrusion with lubricant compositions of very high ionomer content can be dispensed with a wax additive. In most embodiments, however, an addition of at least one wax is advantageous. The at least partially softened or at least partially melting coating can raise during cold working on the workpiece to be formed and form a release film between the workpiece and the tool. As a result, e.g. Grooves in the workpiece are avoided.

The weight ratio of the contents of at least one wax to the total content of ionomer (s) and / or non-ionomer (s) in the lubricant composition and / or in the coating formed therefrom preferably ranges from 0.01: 1 to 8: 1, especially preferably in the range of 0.08: 1 to 5: 1, from 0.2: 1 to 3: 1, from 0.3: 1 to 2: 1, from 0.4: 1 to 1, 5: 1, of 0.5: 1 to 1: 1 or from 0.6: 1 to 0.8: 1. As a result, different content ranges can be particularly advantageous: once very low, sometimes very high levels. A comparatively very high wax content is recommended for sliding pull, deep drawing and light to medium hard cold forming. A comparatively low wax content has been found in heavy cold extrusion or difficult sliding pull operations such as e.g. of solid parts and extra-thick wire proved sufficient.

Particular preference is given to a content of two, three, four or more than four different waxes, in particular those which have significantly different have melting areas / Schnnelzpunkte and / or viscosities. In this case, it is preferred that the lubricant composition and / or the coating formed therefrom have a plurality of successive softening areas / softening points or / and melting areas / melting points over a larger temperature range, which is passed through the cold forming during heating of the metallic workpiece, in particular such that there is a substantially continuous change in the thermal and / or mechanical properties and / or viscosity of the lubricant composition and / or the softening / / melting and / or melting coating.

Frequently, the waxes in the lubricant composition and / or in the coating formed therefrom have at least one melting range / melting point in the range from 50 to 120 ^° C. (eg paraffin waxes), from 80 to 90 ^° C. (eg carnauba waxes), from 75 to 200 ^° C. ( such as amide waxes), 90-145 ⁰ C (eg, polyethylene waxes) or 130-165 ⁰ C (eg, polypropylene waxes) on. Low-melting waxes can also serve to ensure lubrication and reduce friction in the early stages of cold forming, especially when the workpiece is cold and when the tool is cold. In addition, it may be advantageous, even at least two low-melting waxes - for example, with at least one melting range / melting point T _m in the range of 60 to 90 or 65 to 100 ⁰ C - and / or at least two high-melting waxes - for example, with at least a melting range / melting point T _m in the range of 110 to 150 or 130 to 160 ⁰ C - to use. This is particularly advantageous if these waxes have significantly different viscosities at those low or high temperatures in the range of the melting range / melting point, whereby a certain viscosity can be set in the heated or / and melting lubricant composition. For example, a high melting amide wax may be less viscous than a high melting polyethylene or / and polypropylene wax. Depending on the conditions of use, that is, depending on the workpiece and its complexity, the forming process and the severity of the cold forming and the expected maximum temperatures at the workpiece surface, but possibly also with respect to certain melting ranges / melting points, the waxes are spread over the desired processing range, in particular over the desired temperature range selected.

Solid lubricants and friction modifiers:

The lubricant composition and / or the coating formed therefrom may contain at least one solid lubricant and / or at least one friction modifier. In particular, at least one such additive in the lubricant composition, in the coating formed therefrom and / or in the film formed on a coating based on at least one solid lubricant is advantageous when high degrees of deformation are required. The total content of at least one solid lubricant and / or at least one friction modifier in the lubricant composition and / or in the coating formed therefrom is preferably either zero or in the range of 0.5 to 50, 1 to 45, 3 to 40, 5 to 35, 8 to 30, 12 to 25 or 15 to 20 wt .-% of the solids and active ingredients.

If required, at least one solid lubricant may be added to the lubricant composition and / or on the other hand a film containing at least one solid lubricant may be applied to the coating prepared with an aqueous lubricant composition. Usually, then worked with at least one solid lubricant when the solid lubricant-free coating for the type and severity of cold working and for the complexity of the workpiece is no longer sufficient, but there is a risk that a cold welding between the workpiece and tool occurs that greater dimensional inaccuracies in the formed Workpiece occur and / or that lower degrees of deformation than expected under the working conditions can be achieved. Because in the gel will be tried to work as long as possible without solid lubricant.

The solid lubricant may preferably be molybdenum disulfide, tungsten sulfide, bismuth sulfide or / and amorphous or / and crystalline carbon. For reasons of environmental protection, heavy metal-free work is preferably also carried out. All of these solid lubricants have the disadvantage of strongly staining and heavily soiling. The sulfidic solid lubricants have the disadvantage that the sulfides are not resistant to hydrolysis and are easily converted into sulfurous acid. The sulfurous acid can easily cause corrosion if the solid lubricant containing coating and the solid lubricant containing deposits are not removed from the workpiece immediately after cold working.

The sulfidic solid lubricants are particularly necessary for heavy cold forming and resulting medium to high temperature. The carbon additives are particularly advantageous at very high temperature and with a higher degree of deformation. While molybdenum disulfide can be used up to temperatures of about 450 ⁰ C, graphite can be used up to temperatures of about 1100 ⁰ C, but its lubricating effect at the cold forming begins approximately at 600 ⁰ C. Therefore, a mixture of molybdenum disulfide powder, preferably particularly finely ground, is often used together with graphite or / and amorphous carbon. But carbon addition can lead to unwanted carburizing of an iron material. And sulfide addition can even lead to intercrystalline corrosion in stainless steel.

The lubricant composition of the present invention and / or the coating formed therefrom preferably has no content or content of at least one solid lubricant in the range of 0.5 to 50, 1 to 45, 3 to 40, 5 to 35, 8 to 30, 12 to 25 or 15 to 20 wt .-% of solids and active ingredients. Among the other friction modifiers, at least one of the following substances may be used in the lubricant composition: alkali nitrate, alkali metal formate, alkali metal propionate, phosphoric acid ester - preferably as amine salt, thiophosphate such as zinc dialkyldithiophosphate, thiosulphate and / or alkali pyrophosphate - the latter preferably combined with alkali thiosulphate. They participate in many embodiments in the formation of a protective layer and / or a release layer for separating workpiece and tool and help to avoid cold welding between the workpiece and tool. But they can be partially corrosive. Because the phosphorus and / or sulfur-containing additives can react chemically with the metallic surface.

The lubricant composition of the invention and / or the coating formed therefrom preferably has / does not have a content or a content of at least one coefficient of friction in the range from 0.05 to 5 or 0.1 to 4% by weight of the solids and active substances, especially preferably in the range of 0.3 to 3, from 0.5 to 2.5 or from 1 to 2 wt .-%.

additives:

The lubricant composition and / or the coating formed therefrom may each contain at least one additive. It may contain at least one additive selected from the group consisting of wear-protecting additives, silane additives, elastomers, film-forming auxiliaries, corrosion inhibitors, surfactants, defoamers, leveling agents, biocides, thickeners and organic solvents. The total content of additives in the lubricant composition or / and in the coating formed therefrom is preferably in the range of 0.005 to 20, 0.1 to 18, 0.5 to 16, 1 to 14, 1 to 5, to 2, to 10 , 2.5 to 8, 3 to 7 or 4 to 5.5 wt .-% of solids and active ingredients. Thickeners based on non-ionomers are excluded at these levels and are considered in the non-ionomers. Depending on the intended conditions of use and cold forming operations and on the design of the lubricant composition and / or the coating, the content and the selection of additives can vary within wide limits.

Further, in the lubricant composition and / or in the coating formed therefrom, preferably at least one of the following substances may be used to act as wear-protecting additives and / or as friction modifiers: Organic polymeric substances of increased temperature stability, e.g. Polyamide powder or / and fluorine-containing polymer such as e.g. PTFE - where both classes belong to the non-ionomers, silanes / silanols / siloxanes (= silane additive), polysiloxanes, but also in particular calcium-containing phosphates can act as such. The lubricant composition of the invention and / or the coating formed therefrom preferably does not have a content or content of at least one wear-resistant organic substance in the range of 0.1 to 10 or 0.5 to 8% by weight of the solids and active ingredients. Preferably, this content is 1 to 6, 2 to 5 or 3 to 4 wt .-% of the solids and active ingredients.

In experiments, various aqueous solutions with at least one silane additive in concentrations in the range of 5 to 50 wt .-%, in particular an 8%, a 12% and an 18% solution, based on at least one Silane / silanol / siloxane based on γ-aminopropyltriethoxysilane, diaminosilane or / and 1, 2-bis (thmethoxysilyl) ethane used to pre-rinse the phosphated workpiece, dried and then coated with the lubricant composition. Alternatively, this solution may also be mixed with the aqueous lubricant composition. In both variants, this addition had a significant improvement in lubricity. In particular, for this purpose, at least one acyloxysilane, an alkoxysilane, a silane having at least one amino group such as an aminoalkylsilane, a silane having at least one succinic group and / or succinic anhydride group, a bis-silyl silane, a silane having at least one epoxy group such as a glycidoxysilane (Meth) acrylato-silane, a multi-silyl-silane, a ureidosilane, a vinylsilane or / and at least one silanol or / and at least one siloxane of chemically corresponding composition such as the abovementioned silanes in the lubricant composition or / and in the coating be included.

It may preferably contain at least one elastomer, in particular a hydroxy-terminated polysiloxane, preferably having a molecular weight greater than 90,000, for increasing lubricity and scratch resistance, in particular at a content of from 0.01 to 5 or from 0.2 to 2.5 % By weight of the solid and active substances of the lubricant composition or / and of the coating.

It may preferably contain at least one film-forming assistant for producing a substantially or wholly-closed organic coating. In most embodiments, the cold-working coating will not be completely closed, which is sufficient for these purposes when subsequently removed from the formed workpiece. However, if the coating is to remain at least partially at least partially on the formed workpiece, in some embodiments, the addition of at least one film-forming aid may be advantageous. A film formation under the action of the at least one film-forming auxiliary can be carried out in particular together with corresponding non-ionomers and, for example, with water glass. In particular, the film can be formed together with ionomers, non-ionomers and, for example, with water glass. The addition of film-forming aids is particularly worthwhile for coatings which, after cold forming, are at least partly to be retained on the formed workpiece, for example in the case of steering parts. As a result, the workpiece can be permanently protected against corrosion there. As film-forming aids usually long-chain alcohols and / or alkoxylates are used. Preferably, in each case at least one butanediol, a butyl glycol, a butyl diglycol, an ethylene glycol ether or / and in each case at least one polypropylene glycol ether, a polytetrahydrofuran, a polyether polyol or / and a polyester polyol used. Preferably, the level of film-forming assistant (s) in the lubricant composition is in the range of 0.03 to 5% by weight of the lubricants and / or coating solids and / or the coating, more preferably 0.1 to 2% by weight. The weight ratio of organic film-forming agent contents to film-forming aids in the lubricant composition is preferably in the range of 10: 1 to 400: 1, 20: 1 to 250: 1, or 40: 1 to 160: 1, more preferably in the range of 50: 1 to 130: 1, from 60: 1 to 110: 1 or from 70: 1 to 100: 1.

The lubricant composition of the invention may preferably contain at least one anticorrosive agent, e.g. based on carboxylate, dicarboxylic acid, organic amine salt, succinate or / and sulfonate. Such an additive may in particular be applied to coatings which are to remain on the reshaped workpiece at least partly permanently, or at the risk of rusting, e.g. in Flash Rusting, be beneficial. The at least one corrosion inhibitor is preferably contained in a content of 0.005 to 2 wt .-% of the solids and active ingredients of the lubricant composition and / or the coating, particularly preferably from 0.1 to 1, 2 wt .-%.

The lubricant composition may preferably each contain at least one surfactant, a defoamer, a leveling agent and / or a biocide. These additives are preferably each contained in a content of 0.005 to 0.8 wt .-% of the solids and active ingredients of the lubricant composition o- / / and the coating, particularly preferably from 0.01 to 0.3 wt .-%.

A surfactant can serve as a leveling agent. At least one surfactant may in particular be a nonionic surfactant; this is preferably an ethoxylated fatty alcohol with 6 to 20 ethylene oxide groups. The at least one surfactant is preferably in a content of 0.01 to 2 wt .-%, especially preferably from 0.05 to 1.4% by weight. The addition of a defoamer may possibly be advantageous in order to brake the tendency to foam, which can be increased or caused in particular by an added surfactant.

The lubricant composition may preferably contain at least one thickener, which belongs to the non-ionomers as a polymeric organic thickener and otherwise belongs not to the non-ionomers but to the additives. For this purpose, preference is given in each case to at least one primary or / and tertiary amine-containing compound, a cellulose, a cellulose derivative, a silicate, such as e.g. one based on bentonite or / and at least one other phyllosilicate, a starch, a starch derivative and / or a sugar derivative. It is preferably contained in the lubricant composition and / or in the coating formed therefrom in a content of 0.1 to 12 or from 1 to 6 wt .-% of the solids and active ingredients of the lubricant composition and / or the coating.

In addition, if appropriate, at least one organic solvent or / and at least one solubilizer may also be added or contained in the lubricant composition.

Preferably, no or no higher contents (eg less than 0.5% by weight of the solids and active substances of the lubricant composition and / or the coating) of chlorine-containing compounds are present in the lubricant composition and / or in the coating formed therefrom Fluorine-containing compounds such as in particular fluorine-containing polymers / copolymers, compounds based on or containing isocyanate or / and isocyanurate, melamine resin, phenolic resin, polyethyleneimine, polyoxyethylene, polyvinyl acetate, polyvinyl alcohol, polyvinyl ester, polyvinylpyrrolidone, stronger corrosive substances, environmentally unfriendly and / or toxic heavy metal compounds, borates, chromates, chromium oxides, other chromium compounds, molybdates, phosphates, polyphosphates, vanadates, tungstates, metal powders and / or an in cold forming conventional soap such as alkali and / or alkaline earth stearates and / or as further derivatives of fatty acids having a chain length in the range of about 8 to about 22 carbon atoms. In particular, in embodiments that are free of non-polymer, it is preferable not to add a film-forming aid to the lubricant composition.

Total composition:

The lubricant composition in many embodiments has a solids and active ingredient content preferably in the range of 2 to 95% by weight, in particular in the range of 3 to 85, 4 to 70 or 5 to 50, 10 to 40, 12 to 30 or 15 to 22 Wt .-%, wherein the remaining contents up to 100 wt .-% are either only water or predominantly water with contents of at least one organic solvent or / and at least one solubilizer. Preferably, the aqueous lubricant composition is agitated prior to its application to the metallic surface.

When used as a so-called concentrate, the aqueous lubricant composition may have a solids and active substance content preferably in the range from 12 to 95, 20 to 85, 25 to 70 or 30 to 55% by weight, as application mixture ("bath") preferably in the range from 4 to 70, 5 to 50, 10 to 30 or 15 to 22 wt .-%. At low concentrations, the addition of at least one thickener may be advantageous.

In the method according to the invention, the metallic particles to be cold formed with the lubricant composition can preferably be wetted for a time of 0.1 second to 1 hour. The duration of wetting may depend on the type, shape and size of the metallic moldings as well as the desired layer thickness of the coating to be produced, for example long tubes often being introduced obliquely into the lubricant composition, so that the air can escape over a relatively long period of time, in particular inside the tube. The application of the aqueous lubricant Composition on the workpiece can be carried out using all methods customary in surface technology, for example by manual or automated application, by spraying and / or dipping and optionally additionally by squeezing and / or rolling, if appropriate in a continuous dip method.

In order to optimize the lubricant composition, particular attention must be paid to the pH adjustment, the viscosity at the elevated temperatures involved and the choice of substances to be added for graded softening / softening points and / or melting ranges / melting points of the various components of the lubricant composition ,

Here, the cold-formed metallic molded body with the lubricant composition at a temperature preferably in the range of room temperature to 95 ⁰ C, in particular at 50 to 75 ⁰ C, wetted. When the temperature is in the wetting of the metallic mold body at 45 ⁰ C, the drying usually proceeds without any additional measures, such as rinsing of stronger with warm air or treatment with radiation heat very slowly; Moreover, if the drying is too slow, oxidation of the metallic surface, in particular rusting, such as Flash Rust, may occur.

In this case, a coating of the lubricant composition is formed, the chemical composition of which does not have to match the starting composition and the phase content of the aqueous lubricant composition in every variant, but which largely or completely matches in many embodiments. In most embodiments hardly or no crosslinking reactions occur. For most or all of the embodiments involve drying of the aqueous lubricant composition on the metallic surface. The added substances are preferably selected such that the softening ranges / softening points or / and melting ranges / melting points of the individual polymeric constituents (monomers, monomers, oligomers, cooligomers, polymers or / and copolymers of the polymeric organic material), if appropriate also the Spread waxes and any additives that may be present over the temperature range, which is limited by the ambient or elevated temperature benchmarks in the range of 20, 50, 100, 150 or 200 ^° C to 150, 200, 250, 300, 350 or 400 ^° C. By distributing the softening weichungspunkte / ER and / or melting ranges / melting points of the individual organic polymeric constituents, for example, about 20 to 150 ⁰ C, over 30 or 80 or 120 to 200 ⁰ C, above 50 or 100 or 150 to 300 ⁰ C. the friction in each temperature range, which is traversed during cold forming, facilitated by at least one softened and / or molten substance and thereby usually the cold forming is guaranteed.

Coatings:

The lubricant layer (= coating) produced with the lubricant composition according to the invention typically has a composition which is substantially or completely identical to the composition of the aqueous lubricant composition, if the content of water, optionally of organic solvent and optionally of other evaporating constituents and of the optionally occurring condensation, crosslinking and / or chemical reactions is omitted.

Typically, the coating produced with the lubricant compositions of the invention is intended to facilitate cold working and thereafter be removed from the formed workpiece. In particular embodiments, such as axles and steering parts, the composition according to the invention may be designed in such a way that the overlay train is particularly suitable for permanent retention on a formed workpiece, for example by using a content of at least one curing agent for thermal crosslinking, on at least one resin which is suitable for free-radical curing such as UV curing, on at least one photoinitiator for example, for a UV curing or / and on at least one film-forming aid to produce a particularly high-quality and closed in many variants coating. The cured, crosslinked and / or post-crosslinked coatings can provide increased corrosion resistance and hardness compared to the coatings of the other embodiments.

Particularly high-quality coatings for higher or the highest mechanical and / or thermal requirements have proven to be those in which the liquid, drying or / and dry coating which has been applied with the aqueous lubricant composition according to the invention up to temperatures of at least 200 ⁰ C no stronger softening or / and only a limited softening or no softening until at least 300 ⁰ C shows.

For wire drawing, it has proven to be advantageous if at the surface temperatures of the wire during wire drawing softening and / or melting occurs, because then gave uniform beautiful lint-free metallic surfaces. The same applies to other Gleitziehverfahren and for light to medium cold extrusion.

The organic polymeric coatings deposited on phosphate layers in continuous flow systems were designed to give good adhesion over long working ranges and, together with the phosphate coatings, to give good results during cold forming. Variation of the treatment time from 1 to 120 s revealed no differences in quality. However, it has proven to be advantageous if the phosphated workpiece such as a phosphated wire or a phosphated wire bundle has sufficient time to a favorable coating temperature For example, in the range of 30 to 70 ⁰ C to warm up. For this purpose, it may be advantageous to give the phosphated workpieces a warm-up time of one or a few seconds, for example 2 s. In many embodiments, the treatment time of these workpieces in continuous lines with the aqueous lubricant composition will be in the range of 1 to 20 seconds, especially 2 to 10 seconds. Here, polymeric organic coatings are often formed with a coating weight in the range of 1 to 6 g / m ² or / and with a thickness approximately in the range of 0.5 to 4 microns. Even longer treatment times and / or even thicker coatings usually do not bother.

The coating applied from the aqueous lubricant composition preferably has a coating weight in the range from 0.3 to 15 g / m ² , in particular from 1 to 12, from 2 to 9 or from 3 to 6 g / m ² . The layer thickness of the coating is adjusted according to the conditions of use and can be present in particular in a thickness in the range from 0.25 to 25 μm, preferably in the range from 0.5 to 20, from 1 to 15, from 2 to 10, from 3 to 8 or from 4 to 6 μm.

As workpieces to be reshaped, usually bands, sheets, slugs (= wire sections, profile sections, round blanks and / or pipe sections), wires, hollow profiles, solid sections, rods, tubes or / and more complicated shaped parts are used.

The cold formed metallic moldings can basically consist of any metallic material. Preferably, they consist essentially of steel, aluminum, aluminum alloy, copper, copper alloy, magnesium alloy, titanium, titanium alloy, in particular mild steel, high-strength steel, stainless steel or / and metallically coated steel, e.g. aluminized or galvanized steel. In most cases, the workpiece consists essentially of steel.

If required, the metallic surfaces of the metallic workpieces to be cold formed and / or the surfaces of their metallic coated coating before wetting with the aqueous lubricant composition tion in at least one cleaning method to be cleaned, in principle, all cleaning methods are suitable for this purpose. The chemical and / or physical cleaning may include, above all, peeling, blasting, such as annealing, sandblasting, mechanical descaling, alkaline cleaning, and / or acid pickling. Preferably, the chemical cleaning is carried out by degreasing with organic solvents, by cleaning with alkaline and / or acidic cleaners, with acid pickling or / and by rinsing with water. The pickling and / or blasting is used primarily for descaling the metallic surfaces. In this case, it is preferable, for example, only to anneal a welded tube made of cold strip after welding and scraping, for example to pickle, rinse and neutralize a seamless tube or to degrease and rinse, for example, a stainless steel slug. Parts made of stainless steel can be brought into contact both moist and dry with the lubricant composition, since rusting is not to be expected.

If necessary, the cold-formed metallic shaped bodies can be precoated with the lubricant composition according to the invention before wetting. If necessary, the metallic surface of the workpiece can be provided, prior to wetting with the lubricant composition according to the invention, with a metallic coating consisting essentially of a metal or of a metal alloy (eg aluminized or galvanized). On the other hand, the metallic surface of the workpiece or its metallically coated coating can be provided with a conversion coating or / and with a coating containing inorganic particles, in particular oxalated or phosphated. The conversion coating may preferably be carried out with an aqueous composition based on oxalate, alkali phosphate, calcium phosphate, magnesium phosphate, manganese phosphate, zinc phosphate or corresponding mixed crystal phosphate such as CaZn phosphate. Often, the metallic moldings are also blank, that is, without a prior Konversi- Onsbeschichtung be wetted with the lubricant composition according to the invention. The latter is only possible if the metallic surface of the workpiece to be formed is previously cleaned chemically and / or physically.

The metallic form bodies become after the coating with the

Lubricant composition preferably thoroughly dried, in particular with warm air and / or radiant heat. This is often necessary because, as a rule, water contents in coatings interfere with cold forming, because otherwise the coating can be insufficiently formed and / or because a coating of inferior quality can be formed. This can also occur quickly Anrosten.

Surprisingly, the coating according to the invention, with sufficient drying, is of such good quality that, when the metallic coated moldings are carefully handled, it is not damaged and is not partly removed.

The metallic moldings coated in accordance with the invention can be used for cold forming, in particular for sliding, e.g. of tubes, hollow sections, bars, other solid sections and / or wires, for ironing and / or deep drawing, e.g. of tapes, sheets or / and hollow bodies, e.g. to hollow bodies, for cold extrusion e.g. hollow bodies and / or solid bodies and / or for cold heading, e.g. from wire sections to connectors such as e.g. to bolts and / or screw blanks, sometimes also several, possibly even different, cold forming operations can be performed sequentially.

In the method according to the invention, after the cold forming, the formed workpiece may preferably be at least partially cleaned of the remaining coating or / and the deposits of the lubricant composition. In the method according to the invention, the coating on the reshaped workpieces may, if necessary after cold forming, remain at least partially permanent.

The object is also achieved with a lubricant composition according to the invention for application to a workpiece to be formed and for cold forming.

The object is also achieved with a coating which has been formed from a lubricant composition according to the invention.

It also relates to the use of a lubricant composition according to the invention for application to a workpiece to be formed and for cold forming and to the use of a coating according to the invention for cold forming and optionally also as a durable protective coating.

It has been found that during the electrolytic phosphating of especially calcium-rich phosphating solutions, brushite CaHPO ₄ and its mixed crystals are deposited. It is assumed that during cold forming, brushite is converted into tricalcium phosphate at temperatures above approx. 90 ^° C, whereby phosphoric acid is liberated. It is assumed that the phosphoric acid on the one hand forms a thin protective and separating layer on the metallic surface, but on the other hand reacts with the constituents of the polymeric basic coating, in particular with amine groups and amines. In this case, for example, an amine such as, for example, an amine alcohol can be converted to amine phosphate. Amine phosphate acts as a friction modifier and wear protection, which also supports polar lubrication. During cold forming, amine and phosphoric acid can then be released again at high pressure and / or high temperature. These chemical reactions can have an advantageous effect on cold forming. Therefore, brushite-based phosphate films and polymeric coatings are optionally substituted with amine groups or / and with at least one amine, but without alkali and without alkaline earth metal in excess considered to be particularly advantageous. For such embodiments, it may be advantageous for the at least one amine to be present in an increased excess of the required levels to react with the ionomers and / or non-ionomers needed in the aqueous lubricant composition.

When producing screws in a screwdriver, phosphate coatings with a polymeric coating according to the invention can work faster by about 20% compared to phosphate coatings with a soap-based lubricant coating.

It has surprisingly been found that even a very small addition of a water-soluble, water-containing or / and water-binding oxide o- / silicate, especially of water glass, but also a high addition leads to a significant improvement of the coating according to the invention, which leads to a significantly improved cold working under otherwise identical conditions and can be used in more severe cold forming than comparable, free of these compounds lubricant compositions. In addition, the coating according to the invention can also be used for cold forming at higher force and at higher temperature without the addition of solid lubricants and without applying a separate solid lubricant layer as comparable Ü- coatings without this addition. Furthermore, this addition also has a significant anti-corrosive effect.

Surprisingly, it was also found that the cold extrusion - especially of steel scraps - according to the invention particularly low friction and especially without breakage of the tool even when using significantly increased forces. Thus, it is possible to produce coatings for the range of extreme pressing pressures, as well as for the area of maximum wear minimization during cold forming, increased forming accuracy, and / or increased forming speed. For example, by dipping, pulling out and drying can be applied easily, reproducibly and inexpensively.

Inventive Examples and Comparative Examples:

Slabs of hardened carbon steel C15.1.0401 of 90 - 120 HB of approx. 20 mm diameter and approx. 20 mm in height were electrolytically or non-electrolytically phosphated with various phosphating solutions (Tables 1). The coating of the phosphated slugs with the polymeric and mostly aqueous lubricant composition according to the invention was carried out by dipping for 1 min and then drying for 10 min at 60 to 65 ⁰ C in a convection oven. These doubly coated dried slugs were then cold worked in a press by backward extrusion at 300 tons.

An aqueous lubricant concentrate was applied with vigorous stirring with a dissolver, initially with demineralized water and, if appropriate, an addition of a neutralizing agent such as, for example, an aminalcohol. On the one hand compositions (A) were used with an amine alcohol, which were initially kept at temperatures in the range of 80 to 95 ⁰ C, on the other hand compositions (B) were set with an ammonium content, the entire time at room temperature or / and up to 30 ⁰ C were held. The contents of amino alcohol or ammonium ions served to neutralize (= formation of an organic salt) or to obtain organic salts in the aqueous composition.

In the lubricant compositions (A) and (B) as mixtures, lubricant concentrates and baths was basically the same procedure. First, the at least one ionomer based on ethylene acrylate was added to the initially introduced water, partly as a dispersion. For this purpose, the mixture (A) was further maintained at temperatures in the range of 80 to 95 ⁰ C and further stirred vigorously with a dissolver to the neutralization and to allow salt formation. This resulted in a transparent liquid after some time. For mixtures (B), the at least one ionomer based on ethylene acrylate in the form of at least one dispersion of at least one organic ammonium salt was added and further stirred vigorously with a dissolver. Thereafter, to the blends (A) and (B), the non-ionomers were added first in dissolved and / or dispersed form and then in powder form with vigorous and long-term stirring with a dissolver. For this purpose, in the case of the mixtures (A), the temperature was lowered again to the range from 60 to 70 ^° C. Furthermore, further additives such as biocide, wetting agent and corrosion inhibitor and finally at least one thickener for adjusting the viscosity were added as needed. If necessary, the respective concentrate was filtered and the pH was adjusted. To coat the metallic workpieces to be formed, the respective concentrate was diluted appropriately with demineralized water and, if necessary, the pH was adjusted. The baths with the aqueous lubricant composition were stirred gently over time and kept at a temperature in the range of 50 to 70 ⁰ C (bath A) or 15 to 30 ⁰ C (bath B).

Tables 2 show the lubricant compositions and the suitability of the coatings formed therewith for phosphate coatings for certain cold forming operations and their degree of deformation. The remainder to 100 wt .-% form the additives and solid lubricants, only the latter are given. The ionomers used are ethylene acrylates and / or ethylene methacrylates ("ethylene acrylate"). "Ammonium polymer" refers to organic polymeric ammonium salts of the non-ionomers which have been added as dispersions. Among the additives, only the solid lubricants are given, which is why the sum of the solids and active ingredients does not give 100 wt .-%. The ionomers of types A and C have a slightly higher molecular weight and a significantly higher melt viscosity (viscosity at high temperature, especially in the area of softening or melting) than the ionomers of types B and D. The ionomers of Types A and B were reacted with an amine alcohol in the preparation of the aqueous lubricant composition. The ionomers of types C and D have an ammonium content and have already been added as organic salts.

Table 1: Compositions of the aqueous acidic phosphating solutions during electrolytic or electroless phosphating with content data in g / L, with the electrical conditions and the layer properties

Table 2: Compositions of the aqueous lubricant compositions with details in% by weight of the solids and active ingredients and the suitability of the coatings formed therewith for phosphate coatings for certain cold forming operations and their degree of deformation for a variety of basic compositions with a varying content of the various components

Cold forming operations: AZ = ironing, GZ = sliding, HF = hydroforming, KFP = cold extrusion, KS = cold heading, TP = tumbling, TZ = deep drawing

Solid lubricants: G = graphite, M = molybdenum disulfide

* = excluded and possibly excess fraction, so that the sum is above 100% by weight, since at least some of the ionomers and non-ionomers are present as salt

** = ionomer Table 1

Table 2

The experiments in Table 1 showed that the most varied phosphating compositions could be deposited electrolytically or non-electrolytically. For the compositions of B1 and B10, different deposition conditions were chosen. Very short term deposition conditions were also used at comparatively high current densities and voltages. The coatings were mostly good or even very good. The phosphate coatings show slightly different properties. CaZn- and Ca-containing phosphate layers have proven particularly useful. In addition, it was found that Ca and CaZn phosphate coatings are better suited for cold forming than Zn phosphate coatings, since Ca phosphate and CaZn phosphate are still more stable than Zn phosphate at higher temperatures than 270 ^° C that they can be used in cold forming up to higher temperature than Zn-phosphate. The phosphate layer adheres to the metallic surface only as long as it does not change more strongly by chemical or / and physical reactions. As the phosphate layer changes, it at least partially bursts off the metallic backing. The ejection forces of the press for cold forming are much lower for phosphate coatings based on Ca or CaZn than for those based on Zn. In addition, Ca phosphate and CaZn phosphate were found to be longer tool life due to reduced friction during ongoing cold forming as Zn phosphate. In addition to the environmental friendliness of the heavy metal-free phosphate coatings, their lighter color with regard to soiling is also an advantage. It has been found that particularly adherent and sufficiently rough phosphate coatings can be produced which adhere well to very well to the metallic surfaces and on the other hand provide a high-quality primer for the novel polymeric coatings, which adhere well to very well. The tests in Table 2 showed that the content of the lubricant compositions according to the invention can be varied to a great extent on various components. In this case, on the one hand, the addition of at least one ionomer, but also of at least one wax and, if appropriate, of water glass, has proved particularly useful. Essentially, the lubricant composition and the LJ coating formed therefrom are more or better usable for severe forming if a higher content of ionomer (s) or an additional high content of at least one solid lubricant is included. The lubricant compositions of Examples 19 and 20 are particularly suitable for heavy cold working such as tumble pressing because of the content of graphite or molybdenum disulfide.

The lubricant compositions of the invention allow environmentally friendly coatings that are applied to metallic workpieces in a simple and cost-effective manner and are suitable for simple, moderate or / and particularly heavy cold forming. Due to the use of organic salts, the coatings and corresponding deposits can be easily removed after cold working from the formed workpiece.

Claims

claims

1. A method for the preparation of metallic workpieces for cold forming first by applying a phosphate layer and then by applying a lubricant layer (= coating) with a substantial content of organic polymeric material, characterized in that the phosphate layer with an aqueous acidic Phosphatie- tion solution with a substantial Content of calcium, magnesium and / or manganese and phosphate is formed and that the lubricant layer (= coating) is formed by contacting the phosphated surface with an aqueous lubricant composition containing a content of organic polymer material based on ionomer and optionally also contains non-ionomer, and wherein as organic polymeric material predominantly monomers, oligomers, cooligomers, polymers or / and copolymers based on ionomer, acrylic / methacrylic acid, epoxy, ethylene, polyamide, propylene, styrene, urethane, their esters and / or their salt (s) are used, wherein at least one ionomer or / and at least one non-ionomer is at least partially saponified and / or at least partially present as at least one organic salt in the lubricant composition and / or in Ü coating.

2. Process according to claim 1, characterized in that the phosphating solution contains 1 to 200 g / L of compounds of calcium, magnesium or / and manganese including their ions, calculated as calcium, magnesium and manganese, not zinc or less than 60% by weight of the cations zinc and 2 to 500 g / L of phosphate calculated as PO ₄ .

3. The method according to claim 1 or 2, characterized in that is phosphated at an alkaline earth content of more than 80 wt .-% of all cations electrolytically.

4. The method according to any one of the preceding claims, characterized in that the lubricant layer is formed by contacting the surface with an aqueous lubricant composition containing at least one water-soluble, hydrous and / or water-binding oxide and / or silicate and / or at least one Amine alcohol and contains a content of organic polymeric material, and that as the organic polymeric material predominantly monomers, oligomers, cooligomers, polymers or / and copolymers based on ionomer, acrylic acid / methacrylic acid, epoxy, ethylene, polyamide, propylene, styrene, urethane whose ester (s) and / or salt (s) are used.

5. The method according to any one of the preceding claims, characterized in that the lubricant composition and / or the coating formed therefrom contains / contains a content of at least one ionomer in the range of 3 to 98 wt .-% of solids and active ingredients.

6. The method according to any one of the preceding claims, characterized in that the lubricant composition and / or the coating formed therefrom, a content of at least one water-soluble, hydrous and / or water-binding oxide and / or silicate and a content of at least one ionomer, at least one non - Ionomer and / or at least one wax and optionally contains a content of at least one additive / contain.

7. The method according to any one of the preceding claims, characterized in that the water-soluble, hydrous and / or water-binding oxide and / or silicate in each case at least one water glass, a silica gel, a silica sol, a silica hydrosol, a silicic acid ester, an ethyl silicate or / and in each case at least one of their precipitated products, hydrolysis products, condensation products and / or reaction products.

8. The method according to claim 7, characterized in that the content of water-soluble, water-containing or / and water-binding oxides o- / / and silicates in the lubricant composition and / or in the coating formed therefrom 0.1 to 85 wt .-% of solid and active ingredients.

9. The method according to any one of the preceding claims, characterized in that the ionomers consist essentially of ionomeric Copolyme ren optionally together with corresponding ions, monomers, comonomers, oligomers, cooligomers, polymers, their esters o- / / and their salts.

10.A method according to one of the preceding claims, characterized in that the lubricant composition and / or the coating formed therefrom contain / contain other organic polymeric constituents which are not to be regarded as ionomers (= "non-ionomer"), such as oligomers, polymers or / and copolymers based on acrylic acid / methacrylic acid, amide, amine, aramid, epoxide, ethylene, imide, polyester, propylene, styrene, urethane, their esters or / and their salt (s).

11.A method according to claim 10, characterized in that the lubricant composition and / or the coating formed therefrom has a content of at least one non-ionomer in the range of 0.1 to 90

Wt .-% of solids and active substances has / exhibit.

12. The method according to any one of the preceding claims, characterized in that at least one ionomer or / and at least one non-ionomer is at least partially neutralized, at least partially soaped or / and at least partially as at least one organic

Salt in the lubricant composition and / or in the coating is present.

13. The method according to any one of the preceding claims, characterized in that for the neutralization of the lubricant composition in each case at least one primary, secondary or / and tertiary amine, ammonia and / or at least one hydroxide is used as neutralizing agent, in particular at least one amine alcohol.

14. Method according to claim 1, characterized in that the lubricant composition and / or the coating formed therefrom comprise at least one wax, in particular in each case at least one paraffin wax, a carnauba wax, a silicone wax, an amide wax, an ethylene and / or and a propylene-based wax and / or a crystalline wax contains / contain.

15. The method according to claim 14, characterized in that the lubricant composition and / or the coating formed thereof contains / contains a content of at least one wax in the range of 0.05 to 60 wt .-% of solids and active ingredients.

16. The method according to any one of the preceding claims, characterized in that the lubricant composition and / or the coating formed therefrom contains / contain at least one solid lubricant and / or at least one Reibwertm inderer.

17. The method according to claim 16, characterized in that the total content of at least one solid lubricant and / or at least one Reibwertininderer in the lubricant composition and / or in the coating formed therefrom preferably either at zero or in the range of 0.5 to 50 wt .-% the solid and active ingredients lies.

18. The method according to any one of the preceding claims, characterized in that the lubricant composition and / or the coating formed therefrom at least one additive selected from the group consisting of solid lubricants, Reibwertminderern, wear-protective additives, silane additives, elastomers, film-forming aids, Contains corrosion inhibitors, surfactants, defoamers, leveling agents, biocides, thickeners and organic solvents.

19. The method according to claim 18, characterized in that the total content of additives in the lubricant composition and / or in the coating formed therefrom in the range of 0.005 to 20 wt .-% of

Solid and active ingredients lies.

20. The method according to any one of the preceding claims, characterized in that the metallic surfaces of the cold worked metallic workpieces or / and the surfaces of their metallic coated coating are cleaned prior to wetting with the aqueous lubricant composition in at least one cleaning process.

21. The method according to any one of the preceding claims, characterized in that the metallic surface of the workpiece or its metallically coated coating is provided with a conversion coating o / / and with a coating containing inorganic particles.

22. The method according to any one of the preceding claims, characterized in that the conversion coating with an aqueous composition based on oxalate, alkali metal phosphate, calcium phosphate,

Magnesium phosphate, manganese phosphate, zinc phosphate or corresponding mixed crystal phosphate, e.g. CaZn phosphate occurs.

23. The method according to any one of the preceding claims, characterized in that the conversion coating with a current density in the range of 1 and 200 A / dm ² and with a voltage in the range of 0.1 to

50 V is electrolytically formed.

24. The method according to any one of the preceding claims, characterized in that the formed workpiece after the cold forming at least partially cleaned of the remaining coating and / or deposits of the lubricant composition.

25. The method according to any one of claims 1 to 23, characterized in that the coating on the reshaped workpieces after cold forming at least partially remains permanently.

26. A lubricant composition for application to a workpiece to be formed and for cold forming according to any one of claims 1 or 4 to 19.

27. A coating formed from a lubricant composition according to claim 26.

28. Use of a lubricant composition according to any one of claims 1 to 19 for application to a workpiece to be formed and for cold forming.

29. Use of a coating according to claim 27 for cold forming and optionally also as a durable protective coating.