EP2238227B1 - Method for coating metal surfaces with a phosphate layer and then with a polymer lubricant layer - Google Patents

Description

The invention relates to a process for the coating of metallic surfaces first with an aqueous acid 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 ionomer, further polymer / copolymer or / and derivatives thereof and optionally at least one wax, at least one water-soluble, hydrous and / or water-binding oxide or / and silicate, at least one solid lubricant, at least one friction modifier or / and at least one further additive and a corresponding lubricant composition, which is to serve after the formation of a 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 ° C but without heat. The heating occurs only by the deformation and optionally the preheating of the workpieces to be formed. Usually, however, the temperature of the workpieces to be reshaped is about 20 ° C. However, if the workpieces to be reshaped are preheated to temperatures in the range of 650 to 850 ° C or 900 to 1,250 ° C, this is called warm or hot forming.

• Ein Gleitziehen (Zugdruckumformung) z.B. von geschweißten oder nahtlosen Rohren, Hohlprofilen, Stäben, Vollprofilen oder Drähten,
• ein Abstreckziehen oder/und Tiefziehen z.B. von Bändern, Blechen oder Hohlkörpern zu Hohlkörpern,
• ein Kaltfließpressen (Druckumformen) z.B. von Hohl- oder Vollkörpern oder/und
• ein Kaltstauchen z.B. von Drahtabschnitten zu Verbindungselementen wie z.B. Muttern- oder Schrauben-Rohlingen.

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 used as a release layer between the workpiece and tool to avoid cold welding of the workpiece and tool. For the latter, it is common to have the workpieces with at least one coating of a lubricant or with a lubricant composition provided to reduce the frictional resistance between the workpiece surface and the forming tool. Cold forming includes:

• A sliding pull (train pressure forming) eg of welded or seamless pipes, hollow profiles, bars, solid profiles or wires,
• an ironing and / or deep drawing, for example, of strips, sheets or hollow bodies to form hollow bodies,
• a cold extrusion (pressure forming) eg of hollow or solid bodies and / or
• a cold dipping eg of wire sections to fasteners such as nuts or screw blanks.

Formerly, the cold-forming metal moldings have been made almost exclusively either by applying a grease, an oil or an oil emulsion, or first by coating with zinc phosphate and then by coating either with a soap, especially alkali or alkaline earth stearate or / and with a soap Solid lubricant prepared 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 coatings were often used from chloroparaffins, which are now used for reasons of environmental protection reluctant. 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 necessary, either at least one solid lubricant such as molybdenum disulfide and / or graphite was added to the organic-polymeric composition (second coating, with zinc phosphate being chosen as the first coating) or at least thereof a solid lubricant was applied as a third coating on the organic polymer coating. While molybdenum disulfide can be used up to temperatures of about 450 ° C, graphite can be used up to temperatures of about 1100 ° C, but its lubricating action does not begin until about 600 ° 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. However, zinc phosphate has the disadvantage of not being so environmentally friendly due to the high zinc content and is often less favorable also by the quality of the coating and its structure. 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 of preparing metallic workpieces for cold forming by electrolytic phosphating with an aqueous acid phosphating solution based on Ca, Mg 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 to form metal soaps. But the chemical conversion of Ca-phosphate to Ca-stearate, which promotes cold working, is slower and less complete than expected.

US 2004/0101697 A1 teaches organic thin films on galvanized steel sheets of outstanding corrosion resistance based on 10-55% SiO ₂ nanoparticles, 1-8% crosslinkers and 1-8% tannic acid and / or ammonium vanadate as a corrosion inhibitor. US 5,531,912 protects stearate-free solid lubricants based on ionomer and alkoxylated alcoholic film-forming agent. JP 2002-24195 A1 teaches compositions based on 40-90% ionomer, 1-10% epoxy compound and 9-50% colloidal SiO ₂ particles for coating metallic surfaces with a corrosion-resistant coating. EP 0 711 821 A1 relates to compositions as lubricant carrier salts containing boron compounds and compounds of di- or tricarboxylic acids or / and derivatives thereof. EP 1 454 965 A1 teaches coatings to protect metallic surfaces on basic alkali silicate, lubricants and thickeners.

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.

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 containing an organic polymeric material, which is also referred to as a coating in which the phosphate layer with an aqueous acidic 4 to 100 g / L of compounds of calcium, magnesium and / or manganese including their ions, calculated as calcium, magnesium and manganese, no zinc or less than 30 wt .-% of the cations zinc and 2 to 500 g / L of phosphate calculated as containing PO ₄ , and in which the lubricant layer is formed by contacting the phosphated surface with an aqueous lubricant composition containing at least one ionomer of from 3 to 98% by weight of the solids and active ingredients; water-soluble, hydrous or / and water-binding oxide or / and Si licat in each case at least one water glass, a silica gel, a silica sol, a silica hydrosol, a silicic acid ester and / or an ethyl silicate in a content of 0.1 to 85 wt .-% of the solids and active ingredients and optionally also non-ionomeric organic polymer Material based on acrylic acid / methacrylic acid, epoxy, ethylene, polyamide, propylene, styrene, urethane, esters thereof or / and salt (s) thereof, wherein for the neutralization of the lubricant composition in each case at least one primary, secondary or / and tertiary amine, in particular at least one amine alcohol, is used as a neutralizing agent, wherein at least one organic polymeric material is 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 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 optionally also by adding at least one further additive such as sodium hydroxide or / and chlorate, which are preferably added individually to adapt the phosphating only the bath.

The phosphating solution contains no zinc or its cation content contains less than 30% by weight of the cations zinc, more preferably less than 20, less than 10 or less than 5% by weight of the 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. The phosphating solution contains 4 to 100 g / L of compounds of calcium, magnesium or / and manganese including their ions, calculated as calcium, magnesium and manganese, which may be present in particular as ions, in particular 6 to 70 g / L, especially 10 to 40 g / L. In many embodiments the phosphating solution contains phosphate and a) 5 to 65 g / L of Ca and 0 to 20 g / L of Mg and / or 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 may be at a), b) or c) in particular in the range from 12 to 40 g / L lie. 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, such as e.g. Sodium, potassium or / and ammonium especially for S-value adjustment and to improve the low temperature stability.

The content of phosphating solution of phosphate calculated as PO ₄ is 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 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, especially as nitrate ions, more preferably in the range of 4 to 450 g / L, most preferably in the range of 8 to 300 g / L, in particular in the range of 16 to 200 g / L, especially in the range of 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, peroxy-sulfuric 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 nitrogenous 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 in guanidine-based compounds such as nitroguanidine zero, near zero, or in the range of 0.1 to 10 g / L calculated as nitroguanidine is particularly preferred 0.2 to 8 g / L, most preferably in the range of 0.3 to 6 g / L, especially in the range of 0.5 to 3 g / L. A guanidine compound such as nitroguanidine can greatly accelerate its content in comparison to other accelerators and nitrate, but does not give off 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) or / and 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 accelerator (s) 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.

Similarly, the free acid score of a phosphating solution is determined using dimethyl yellow as an indicator and titrating to pink 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 titrated to turn 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 more preferably in the range of 10 ° C to 95 ° C. Particularly preferred is a temperature range of 15 to 40 ° C. In electrolytic phosphating, the application temperature of the phosphating solution is preferably in the range of 10 to 60 ° C, especially 15 to 40 ° 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 produced in continuous flow systems on the metallic substrate decreases slightly when the treatment time is less than 1 s or / and more than 10 s. 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, e.g. for each individual wire in a continuous system and often in the range of 0.1 to 100 A for each individual slug or rod, that is 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.

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 chosen 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 must 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 a current for electrolytic phosphating this can be a direct current or an alternating current or a superposition of a direct current and an alternating current are used. 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 from 0.5 to 30 A / dm ² , particularly preferably in the range from 1 to 20 A / dm ² , very particularly preferably in the range from 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. Preferably, the ratio of DC component to AC component is maintained in the range of 20: 1 to 1:10, more preferably in the range of 12: 1 to 1: 4, most preferably in the range of 8: 1 to 1: 2, especially in Range from 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 similarly short tube sections and look as if they had been formed around a fine hydrogen bubble around. These structures often have an average particle size in the range of 1 to 8 microns. This made it possible to make the hydrogen bubbles by addition of a specific accelerator such as nitroguanidine finer, 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 appear particular. 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. Powdery or pasty lubricants or lubricant compositions are preferably presented in a Ziehsteinvorgelege, by the 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 excess formed therefrom contain at least one water-soluble, hydrous or / and water-binding oxide and / or silicate and at least one ionomer, at least one non-ionomeric organic polymeric material present therein Application is also referred to as "non-ionomer", in particular based on acrylic acid / methacrylic acid, epoxy, ethylene, polyamide, propylene, styrene, urethane, their esters or / and their salt (s), or / and at least one wax and optionally a content of at least one additive. In some embodiments, it additionally preferably contains in each case at least one content of acrylic acid / methacrylic acid or / and styrene, in particular as polymer (s) or / and as copolymer (s), which is / are not ionomer (s). Preferably, the lubricant composition and / or the coating formed therefrom each contain / contains at least 5% by weight of in each case at least one ionomer or / and non-ionomer.

Preferably, the organic polymeric material consists essentially of 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 various embodiments, a significant improvement in cold working under otherwise similar conditions is achieved and can be transformed more than comparable, free from these compounds lubricant compositions. On the other hand, it has been found that also workpieces with a coating with a very high content of water-soluble, hydrous and / or water-binding oxide or / and silicate in an otherwise substantially organic polymeric 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 on a broader product spectrum, it has been found that with the lubricant compositions and / or coatings containing water glass, silica gel, silica hydrosol, silicic acid ester and / or ethyl silicate to a far greater extent than previously on an additional solid lubricant layer based on of sulfidic lubricant such as 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 represents a significant labor and cost savings and simplification, but also saves at least one expensive, environmentally unfriendly, strongly blackening and disturbing with respect to 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 for the remaining approximately 40% of the product spectrum and, if appropriate, graphite as the second layer for a zinc phosphate layer, this product spectrum would today be treated first with a zinc phosphate layer, thereafter be coated with a conventional organic-polymeric lubricant composition and optionally additionally, if necessary, with a third coating based on sulfidic solid lubricant and optionally additionally of graphite. Sulphide solid lubricant was at all Moderate and heavy Kaltumformungen necessary. Since the soap layer did not allow accurate cold working - 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, had been 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 in each case be at least one water glass, a silica gel, a silica sol, a silica hydrosol, a silicic acid ester and / or an ethyl silicate, in particular a lithium, sodium or / and potassium-containing one Water glass . Preferably, a content of water in the range from 5 to 85% by weight, based on the content of solids, of or bound to the water-soluble, water-containing or / and water-binding oxide or / and silicate, preferably in the range from 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 and / or in the coating similar to a sliding layer. It can also a mixture of two or at least three substances of this group are used. In addition to or instead of sodium and / or potassium, other cations may be present, in particular ammonium ions, alkali metal ions other than sodium and / or potassium ions, alkaline earth ions and / or transition metal ions. The ions may be or have been at least partially replaced. The water of the water-soluble, water-containing or / and water-binding oxide or / and silicate can in each case be at least partially adsorbed as water of crystallization, as solvent, bound to pore space, in a dispersion, in an emulsion, in a gel or / and in a sol. Particularly preferred is at least one water glass, in particular a sodium-containing water glass. 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 shown that among the water-soluble, water-containing or / and water-binding oxides or / and silicates, water glass behaves particularly favorably. By the addition of, for example, 2 to 5 wt .-% of water glass - based on solids and active ingredients - to the aqueous lubricant composition, the viscosity of the dried, emollient and melting coating in many embodiments, especially at temperatures greater than 230 ° C is significantly increased compared to a lubricant composition on the same chemical basis, 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 with increasing water glass content in the lubricant composition under otherwise identical working conditions 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, water-containing or / and water-binding oxides or / and silicates in the lubricant composition and / or in the coating formed therefrom is from 0.1 to 85, 0.3 to 80 or 0.5 to 75% by weight 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, certainly without the bound thereto or / and 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) or / and non-ionomer (s) in the lubricant composition or / and in the coating is preferably in the range of 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 0.02: 1.

ionomers:

The ionomers are a special type of polyelectrolytes. 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 subset of the copolymers. Preferably, the ionomers are compounds based on acrylic acid / methacrylic acid, ethylene, propylene, styrene, their esters or / and their salt (s) or mixtures with at least one of these ionomeric compounds. The lubricant composition and / or the coating formed therefrom have a content of at least one ionomer in the range 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 solids 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 formed 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 contain 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 _g in the range of - 30 ° C to + 40 ° C, preferably in the range of - 20 to + 20 ° C. The molecular weight of the ionomer is preferably in the range of 2,000 to 15,000, more preferably in the range of 3,000 to 12,000 or 4,000 to 10,000. The lubricant composition and / or 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 / or with a glass transition temperature T _g in the range of - 20 ° C to + 30 ° C. For at least one ionomer based on ethylene acrylate and / or ethylene methacrylate, the acrylate content may be up to about 25% by weight. 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 ° C to the order of about 300, 350 or 400 ° C on the mechanical strength of the hereby produced Coats advantageous and allows 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 the more important the easier or / and weaker the cold forming and the lower the forming temperature.

The melting point of the at least one ionomer is in many embodiments preferably in the range of 30 to 85 ° C. Its glass transition temperature is preferably below 35 ° 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 esters or their salts and their salts, which are not considered ionomers (= "non-ionomer"). 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 to be 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, as substances with waxy substances Properties, as thickener (= viscosity regulators), as additives, to achieve additional softening / softening points and / or melting / melting points or / and for the design of the lubricant composition with multiple softening / softening points and / or melting / melting points at 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 / softening point and / or 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, as a solution, colloidal solution, dispersion, and / or emulsion of the aqueous lubricant composition.

1. a) 0,1 bis 50 Gew.-% und insbesondere 5 bis 30 Gew.-% im Wesentlichen an wachsartigem Polyethylen oder/und an wachsartigem Polypropylen jeweils mit mindestens einem Erweichungsbereich/Erweichungspunkt oder/und Schmelzbereich/Schmelzpunkt oberhalb von 120 °C,
2. b) 0,1 bis 16 Gew.-% und insbesondere 3 bis 8 Gew.-% im Wesentlichen an Polyacrylat mit einem Molekulargewicht im Bereich von 4.000 bis 1.500.000 - besonders bevorzugt im Bereich von 400.000 bis 1.200.000 - oder/und
3. c) 0,1 bis 18 Gew.% und insbesondere 2 bis 8 Gew.-% Polymer/Copolymer auf Basis von Styrol, Acrylsäure oder/und Methacrylsäure mit einem Molekulargewicht im Bereich von 120.000 bis 400.000 o- der/und mit einem Glasübergangspunkt T_g im Bereich von 30 bis 80 °C.

The lubricant composition particularly preferably contains as non-ionomers, which are not waxes in the context of this application:

1. 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 range / melting point above 120 ° C.,
2. 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
3. c) from 0.1 to 18% by weight and in particular from 2 to 8% by weight of polymer / copolymer based on styrene, acrylic acid and / or methacrylic acid having a molecular weight in the range from 120,000 to 400,000 o / and with a glass transition point T _g in the range of 30 to 80 ° 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 under application conditions partially, in particular predominantly 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 produced therewith have a content of in each case at least one ionomer in the range from 3 to 97% by weight of the solids and active substances. Especially preferred the total content of each of at least one ionomer and / or non-ionomer is 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 substances of the lubricant composition or / and of the coating. Thickeners 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.

Neutralizing agents:

For the neutralization of the lubricant composition is used as neutralization. used in each case at least one primary, secondary or / and tertiary amine. Particular preference is given to an addition of at least one alkylamine, of at least one aminal alcohol or / and of 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, 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 and / or in the lubricant composition. The neutralizing agent, in particular at least one aminal alcohol, forms many times in the temperature range from room temperature to about 100 ° C, in particular at temperatures in the range of 40 to 95 ° C, with at least one ionomer and / or with at least one non-ionic 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 Aminalkohol, a For example, it is preferred to add 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 of the aqueous lubricant composition. The previous addition is often beneficial to allow reactions to organic salts. The amines usually react with any organic polymeric material containing carboxyl groups, as far 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. If the temperature remains below the melting point / melting range of the corresponding polymeric compounds, in many cases no conversion to an organic salt will take place. 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 ° C. Aqueous lubricant compositions with an addition of at least one amine should preferably be maintained in a temperature range of 60 to 95 ° 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 at an early stage in the mixing together of the various components of the aqueous lubricant composition and thereby optionally at least one already contained organic polymeric material or / and at least one thereafter 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 and / 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, lower softening ranges / softening points or / and lower melting ranges / melting points result with the organic salts, 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, after application of the aqueous lubricant composition, ammonia quickly escapes, which is not the only thing may represent an odor nuisance, but also causes a back reaction of the ammonium salts to the original organic polymeric substances, which then later can be removed worse than the amine salts. This results in chemically and in water quite resistant coatings. 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 to amine 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 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 0.05: 1.

The lubricant composition of the present invention and / or the coating formed therefrom preferably has a 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 solids and active ingredients on. 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 in amounts of ionomer (s) or / and non-ionomer (s) is in the lubricant composition or / and in the coating preferably in the range of 0.01: 1 to 100: 1, particularly preferably 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 of 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 from 0.01 to 15 μm, particularly preferably in the range from 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 can be dispensed with, in particular if the cold forming 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 contained , 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 lower Wax content has been found to be sufficient for heavy cold extrusion or difficult sliding operations such as solid parts and extra thick wire.

Particularly preferred is a content of two, three, four or more than four different waxes, in particular those having significantly different melting ranges / melting points 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 ( eg amide waxes), from 90 to 145 ° C (eg polyethylene waxes) or from 130 to 165 ° C (eg polypropylene waxes). 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 ° C - or / and 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 ° C - to use. This is particularly advantageous when these waxes at those low or high Temperatures in the range of the melting range / melting point have significantly different viscosities, whereby a certain viscosity can be adjusted in the heated or / and melting lubricant composition. For example, a high melting amide wax may be less viscous than a high melting polyethylene and / or 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 or / and 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 desired, 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 contains. 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 larger dimensional inaccuracies in the formed Workpiece occur and / or that lower degrees of deformation than expected under the working conditions can be achieved. Because usually it 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. Preferably, heavy metal free is also worked for reasons of environmental protection. 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 ° C, graphite can be used up to temperatures of about 1100 ° C, but its lubricating effect at cold working only starts at about 600 ° C. Therefore, a mixture of molybdenum disulfide powder, preferably very finely ground, is often used together with graphite or / and amorphous carbon. But a carbon additive can cause an undesirable carburization lead 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, for example, at least one of the following may be used in the lubricant composition: alkali nitrate, alkali formate, alkali propionate, phosphoric acid ester preferably as amine salt, thiophosphate, e.g. Zinc dialkyl dithiophosphate, thiosulfate and / or alkali metal pyrophosphate - the latter preferably combined with alkali metal thiosulfate. 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 according to the invention or / and the coating formed therefrom preferably has / does not have a content or a content of at least one coefficient of friction reducer in the range from 0.05 to 5 or 0.1 to 4% by weight of the solids and active substances, more 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. You can / at least one additive selected from the group consisting of wear-protective additives, silane additives, elastomers, film-forming aids, Corrosion inhibitors, surfactants, defoamers, flow control agents, biocides, thickeners and organic solvents. The total content of additives in the lubricant composition and / or 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, 1.5 to 12, 2 to 10, 2 , 5 to 8, 3 to 7 or 4 to 5.5 wt .-% of the solids and active ingredients. Thickeners based on non-monomers 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 choice 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 such as polyamide powder and / or fluorine-containing polymer such as 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. 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.

Various aqueous solutions containing at least one silane additive in concentrations in the range from 5 to 50% by weight, in particular also an 8%, a 12% and an 18% solution, based on at least one silane, have been used in experiments. Silanol / siloxane based on γ-aminopropyltriethoxysilane, diaminosilane or / and 1,2-bis (trimethoxysilyl) ethane for prewashing of 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 glycidoxysilane may be used (Meth) acrylato-silane, a multi-silyl-silane, a ureidosilane, a vinylsilane or / and at least one silanol and / or at least one siloxane of chemically corresponding composition such as the aforementioned silanes in the lubricant composition and / or in the coating ,

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 0.01 to 5 or from 0.2 to 2.5 wt. -% of the solid and active substances of the lubricant composition or / and of the coating.

It may preferably contain at least one film-forming aid for producing a substantially or wholly-closed organic coating. In most embodiments, the cold-working coating will not be fully closed, which is quite sufficient for these applications 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. 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. The film can be formed in particular 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 to be at least partially 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 and / or in each case at least one polypropylene glycol ether, a polytetrahydrofuran, a polyether polyol and / or a polyester polyol are 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 coatings solid and active ingredients, 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 according to the invention may preferably contain at least one corrosion inhibitor, for example based on carboxylate, dicarboxylic acid, organic amine salt, succinate or / and sulfonate. Such addition may be particularly advantageous for coatings that are to remain at least partially permanently on the formed workpiece, and / or at the risk of Anros, for example, when Flash Rusting. The at least one anticorrosive agent 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 and / or 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 having 6 to 20 ethylene oxide groups. The at least one surfactant is preferably contained in a content of 0.01 to 2 wt .-%, particularly preferably from 0.05 to 1.4 wt .-%. The addition of a defoamer may u.U. be advantageous to brake the tendency to foaming, which can be enhanced or caused in particular by an added surfactant.

The lubricant composition may preferably contain at least one thickener which belongs to the non-monomers 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, for example, a bentonite-based or / and at least one other layered silicate, a starch, a starch derivative or / and a sugar derivative used. 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 / and contained in the lubricant composition. Preferably, in the lubricant composition and / or in the coating formed therefrom, 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, fluorine compounds containing 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, more strongly corrosive substances, environmentally harmful and / or toxic heavy metal compounds, borates, chromates, chromium oxides, other chromium compounds, molybdates, phosphates, polyphosphates, vanadates, tungstates, metal powders or / and a soap commonly used in cold forming such as alkali and / or alkaline earth stearates and / or further derivatives of fatty acids with a chain 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 of 12 to 95, 20 to 85, 25 to 70 or 30 to 55 wt .-% aufwei sen, as an application mixture ("bath") preferably in the range of 4 to 70, 5 to 50, 10 to 30 or 15 bis 22% by weight. 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 wetting time may depend on the type, shape and size of the metallic moldings as well as on the desired layer thickness of the coating to be produced, e.g. Long pipes are often introduced obliquely into the lubricant composition, so that the air can escape for a long time, especially in the tube interior. The application of the aqueous lubricant composition on the workpiece can be carried out with all methods customary in surface technology, for example by manual and / or automated application, by spraying and / or dipping and optionally additionally by squeezing and / or rolling, optionally in a continuous dip process.

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 ° C, in particular at 50 to 75 ° C, wetted. When the temperature during wetting of the metallic shaped body is below 45 ° C., the drying usually proceeds without additional measures such as, for example, stronger circulation with warm air or treatment with radiant 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, comonomers, oligomers, cooligomers, polymers or / and copolymers of the polymeric organic material), if appropriate also of the waxes and optionally co-acting Distribute additives 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 ranges / softening points or / and melting ranges / melting points of the individual organic polymeric constituents, e.g. above 20 to 150 ° C, above 30 or 80 or 120 to 200 ° C, above 50 or 100 or 150 to 300 ° C, the friction in each temperature range, which is undergone during cold working, by at least one softened and / or molten Substance relieves 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 other evaporating constituents and of the optionally Apart from condensation, crosslinking and / or chemical reactions.

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 e.g. in the case of axles and steering parts, the composition according to the invention may be designed such that the coating is particularly suitable for permanent retention on a formed workpiece, e.g. by using a content of at least one thermal crosslinker curing agent, on at least one resin suitable for free radical curing, e.g. UV curing is suitable, on at least one photoinitiator e.g. for UV curing and / or for at least one film-forming aid to produce a particularly high-quality and in many variants closed 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 highest mechanical and / or thermal requirements have been found to be those in which the liquid, dry and / or dry coating applied with the aqueous lubricant composition of the invention has temperatures of at least 200 ° C no stronger softening or / and only a limited softening or no softening until at least 300 ° 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 warm up to a favorable coating temperature, for example in the range of 30 to 70 ° C. 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 reshaped workpieces mostly bands, sheets, slugs (= wire sections, profile sections, blanks and / or pipe sections), wires, hollow sections, solid sections, rods, tubes and / or more complicated shaped moldings 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 necessary, the metallic surfaces of the metallic workpieces to be cold formed and / or the surfaces of their metallized coating can be cleaned prior to wetting with the aqueous lubricant composition in at least one cleaning procedure, basically 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.

The cold formed metallic moldings are precoated before wetting with the lubricant composition according to the invention. If desired, the metallic surface of the workpiece may be provided, prior to wetting with the lubricant composition of the invention, with a metallic coating consisting essentially of a metal or metal alloy (e.g., aluminized or galvanized). On the other hand, the metallic surface of the workpiece or its metallically coated coating is provided with a conversion coating, namely phosphated. The conversion coating is carried out with an aqueous composition based on calcium phosphate, magnesium phosphate, manganese phosphate or corresponding mixed crystal phosphate, e.g. Ca-Zn-phosphate.

The metallic moldings are preferably thoroughly dried after coating with the lubricant composition, 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 of such good quality that it is not damaged by careful handling of the metallic coated moldings and not partially removed.

The inventively coated metallic moldings can be used for cold forming, in particular for Gleitziehen z. As of pipes, hollow sections, rods, other solid sections and / or wires, for ironing and / or deep drawing z. B. 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 lubricant composition of the invention may be used for application to a workpiece to be formed and for cold forming. The coating of the invention can be used for cold forming and optionally also as a durable protective coating.

It has been found that during the electrolytic phosphating of particularly calcium-rich phosphating solutions, brushite CaHPO ₄ and its mixed crystals are deposited. It is assumed that brushite is converted into tricalcium phosphate during cold forming at temperatures above approx. 90 ° C, whereby phosphoric acid is liberated. It is believed 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 phosphates act as friction modifiers and wear protection, which also support 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, phosphate coatings based on brushite and polymeric coatings optionally with amine groups or / and with at least one amine, but without alkali and without alkaline earth metal contents in excess are 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 for reactions with the ionomers and / or non-ionomers required 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 water glass, silica gel, silica sol, silica hydrosol, silicic acid ester or / and ethyl silicate, but also a high addition to a significant improvement of the coating according to the invention 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 in 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 coatings without this addition. Furthermore, this addition also has a significant anti-corrosive effect.

Surprisingly, it was also found that the cold extrusion - in particular 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 both in the range of extreme pressing pressures, as well as in the area of maximum wear minimization during cold forming, increased molding accuracy or / and increased forming speed. can be applied simply, reproducibly and inexpensively by dipping, pulling out and drying.

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 ° 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, with first demineralized water and optionally an addition of a neutralizing agent such. an amine alcohol was submitted. On the one hand, compositions (A) were prepared with an amine alcohol initially kept at temperatures in the range of 80 to 95 ° C, on the other hand, compositions (B) were prepared with an ammonium content which was at room temperature and / or up to 30 ° C were held. The contents of aminal alcohol or ammonium ions were used for neutralization (= formation of an organic salt) or for obtaining 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 water introduced, partly as a dispersion. For this purpose, the mixture (A) was further maintained at temperatures in the range of 80 to 95 ° C and further stirred vigorously with a dissolver to allow the neutralization and salt formation. This resulted in a transparent liquid after some time. In 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, the temperature was again lowered to the range of 60 to 70 ° C in the mixtures (A). 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 correspondingly diluted with demineralized water and adjusted if necessary, the pH. The baths with the aqueous lubricant composition were stirred gently over time and maintained at a temperature in the range of 50 to 70 ° C (Bath A) or 15 to 30 ° C (Bath B).

• Tabelle 1: Zusammensetzungen der wässerigen sauren Phosphatierungslösungen beim elektrolytischen bzw. stromlosen Phosphatieren mit Gehaltsangaben in g/L, mit den elektrischen Bedingungen und den Schichteigenschaften
• Tabelle 2: Zusammensetzungen der wässerigen Schmierstoffzusammensetzungen mit Angaben in Gew.-% der Fest- und Wirkstoffe und der Eignung der hiermit gebildeten Überzüge auf Phosphat-Beschichtungen für bestimmte Kaltumformvorgänge und ihren Umformgrad für verschiedenste Grundzusammensetzungen mit einem variierenden Gehalt an den verschiedenen Komponenten
• Kaltumformvorgänge: AZ = Abstreckziehen, GZ = Gleitziehen, HF = Hydroforming, KFP = Kaltfließpressen, KS = Kaltstauchen, TP = Taumelpressen, TZ = Tiefziehen
• Festschmierstoffe: G = Graphit, M = Molybdändisulfid
• * = herausgerechneter und ggf. überschüssiger Anteil, so dass die Summe über 100 Gew.-% liegt, da zumindest ein Teil der lonomere und Nichtlonomere als Salz vorliegt
• ** = Ionomer

Tabelle 1 Zugaben in g/L B 1 B 2 B 3 B 4 B 5 B 6 VB 7 B 8 B 9 B 10 PO₄ 39,0 19,5 39,0 39,0 19,5 39,0 12,0 13,8 39,0 39,0 P₂O₅ 29,3 14,7 29,3 29,3 14,7 29,3 9,0 10,4 29,3 29,3 Ca 22,0 11,0 11,0 - - - 3,1 8,3 22,0 22,0 Mg - - - 11,6 - - 3,0 - - 5,0 Mn - - 11,2 11,2 15,1 30,2 - - - - Zn - - - - - - 6,0 5,0 - - Ni - - - - - - 0,3 - - - NO₃ ^- 68,2 34,1 59,3 84,7 34,1 68,2 22,8 24,6 68,2 93,7 ClO₃ ^- - 13,2 26,4 - - - - - - - Nitroguanidin 1,0 - - - - 1,0 - 1,0 - - Heterocyclische Säure - - - - - 5,0 - - - - pH 2,0 2,0 1,9 2,2 2,2 2,0 2,1 2,1 2,0 2,0 FS 11,70 5,90 11,8 7,5 5,5 8,6 3,4 8,8 12,10 10,40 GSF 45,2 21,0 44,0 48,0 22,2 43,6 7,6 8,8 46,0 44,1 GS 78 42 89 80 49 91 20 26 82 84 S-Wert 0,26 0,28 0,27 0,16 0,25 0,20 0,45 1,0 0,26 0,24 B 1a B 1b B 1c B 2 B 3 B 4 B 5 B 6 VB 7 B 8 B 9 B 10a B 10b Mittlere Spannung V 5,5 8 15 6,5 5,0 5,0 5,0 5,5 - - 5,5 4,5 12 Wechselstromanteil A/dm² 6,5 - - - - - - - - - - 10 - Frequenz Hz 1 - - - - - - - - - - 1 - Gleichstromanteil A/dm² 13,0 60,0 120,0 13,4 13,7 5,7 12,2 13,5 - - 16,0 19,1 80,0 Behandlungszeit s 10 2 1 10 5 10 10 10 20 20 5 5 2 Farbe der Beschichtung weiß weiß - hellgrau weiß - hellgrau weiß weiß - hellgrau grau weiß weiß dunkelgrau dunkelgrau hellgrau grau weiß Visuelle Schichtqualität gut sehr gut sehr gut gut gut mittel sehr gut sehr gut gut gut mittel gut gut Haftfestigkeit der Schicht sehr gut sehr gut sehr gut gut gut gut gut sehr gut gut gut gut gut gut Schichtgewicht g/m² 10,0 7,0 7,0 7,6 4,8 4,4 7,4 8,8 16,5 12,0 6,1 6,6 12 Abscheidungsgeschwindigkeit bei 1 A/dm² über 1 min, g/m² 4,0 4,0 3,5 3,4 4,2 4,6 3,6 3,9 - - 3,7 4,1 4,5 Tabelle 2 Beispiel B 11 B 12 B 13 B 14 B 15 B 16 B 17 Ethylenacrylat ** 9,3 23,5 29,7 34,0 65,5 95,2 95,2 Ethylenacrylat-Art ** B B B B A A A Acrylpolymer 6,8 13,2 - - 0,8 - - Styrolacrylat - - 7,8 - 7,9 14,4 - Aminalkohol-Anteil * 2,4 7,2 8,4 6,9 10,1 18,3 18,3 Polymer-Verdicker 11,2 11,2 5,5 - - - - Wachse 52,2 43,5 32,5 50,4 20,2 28,2 - Zahl der Wachse 2 3 2 3 2 3 - T_e/T_m der Wachse °C 68 + 148 68 + 143 + 148 85 + 148 68 + 143 + 148 85 + 148 68 + 85 + 148 - Wasserglas 9,2 7,0 6,5 1,8 2,5 3,2 2,5 Festschmierstoffe - - - - - - - pH-Wert 9,4 9,3 9,5 9,5 9,3 9,6 9,8 verwendbar für AZ GZ KFP KS TZ AZ GZ KFP KS TZ AZ GZ KFP KS TZ AZ GZ KFP KSTZ AZ GZ KFP KS TZ KFP KS KFP Umformgrad max. mittel schwer schwer schwer schwer schwer sehr schwer Beispiel B 18 B 19 B 20 B 21 B 22 B 23 Ethylenacrylat ** 6,2 11,8 14,1 18,7 24,1 43,3 Ethylenacrylat-Art ** C + D C + D C + D C C C Acrylpolymer 6,0 - - - 0,2 1,4 Styrolacrylat 14,3 9,2 11,9 15,9 3,6 2,8 Wachse 56,0 29,2 38,2 50,1 67,8 35,6 Zahl der Wachse 3 3 3 3 2 3 T_e/T_m der Wachse °C 68+85+143 68+143+148 68+143+148 68+143+148 85 + 148 85+143+148 Wasserglas 4,0 1,8 2,5 5,2 3,4 8,7 Festschmierstoffe - 39,9 Graphit 21,0 MoS₂ - - - pH-Wert 9,2 9,0 9,7 8,5 8,0 9,2 verwendbar für GZ TZ AZ GZ HF KFP AZ GZ HF KFP TZ AZ GZ TZ AZ GZ KFP DZ AZ GZ KFP TZ Umformgrad max. mittel mittel - schwer mittel - schwer mittel - schwer mittel - schwer schwer Tables 2 give the lubricant compositions and the suitability of the coatings therewith to 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 were ethylene acrylates or / and ethylene methacrylates ("ethylene acrylate"). By "ammonium polymer" is meant organic polymeric ammonium salts of the non-ionomers 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 (high temperature viscosity especially in the area of softening or / and melting) than the type B and D ionomers. Types A and B ionomers were included the preparation of the aqueous lubricant composition with an amine alcohol. 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 in electrolytic or electroless phosphating with contents in g / L, with the electrical conditions and the layer properties
• Table 2: Compositions of the aqueous lubricant compositions in wt .-% of the solids and active ingredients and the suitability of the coatings formed therewith on phosphate coatings for certain cold forming operations and their degree of deformation for a variety of basic compositions with a varying content of the different 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 Additions in g / L B 1 B 2 B 3 B 4 B 5 B 6 VB 7 B 8 B 9 B 10 PO ₄ 39.0 19.5 39.0 39.0 19.5 39.0 12.0 13.8 39.0 39.0 P ₂ O ₅ 29.3 14.7 29.3 29.3 14.7 29.3 9.0 10.4 29.3 29.3 Ca 22.0 11.0 11.0 - - - 3.1 8.3 22.0 22.0 mg - - - 11.6 - - 3.0 - - 5.0 Mn - - 11.2 11.2 15.1 30.2 - - - - Zn - - - - - - 6.0 5.0 - - Ni - - - - - - 0.3 - - - NO ₃ ^- 68.2 34.1 59.3 84.7 34.1 68.2 22.8 24.6 68.2 93.7 ClO ₃ ^- - 13.2 26.4 - - - - - - - nitroguanidine 1.0 - - - - 1.0 - 1.0 - - Heterocyclic acid - - - - - 5.0 - - - - pH 2.0 2.0 1.9 2.2 2.2 2.0 2.1 2.1 2.0 2.0 FS 11,70 5.90 11.8 7.5 5.5 8.6 3.4 8.8 12.10 10.40 GSF 45.2 21.0 44.0 48.0 22.2 43.6 7.6 8.8 46.0 44.1 GS 78 42 89 80 49 91 20 26 82 84 S value 0.26 0.28 0.27 0.16 0.25 0.20 0.45 1.0 0.26 0.24 B 1a B 1b B 1c B 2 B 3 B 4 B 5 B 6 VB 7 B 8 B 9 B 10a B 10b Mean voltage V 5.5 8th 15 6.5 5.0 5.0 5.0 5.5 - - 5.5 4.5 12 AC component A / dm ² 6.5 - - - - - - - - - - 10 - Frequency Hz 1 - - - - - - - - - - 1 - DC component A / dm ² 13.0 60.0 120.0 13.4 13.7 5.7 12.2 13.5 - - 16.0 19.1 80.0 Treatment time s 10 2 1 10 5 10 10 10 20 20 5 5 2 Color of the coating White white - light gray white - light gray White white - light gray Gray White White dark gray dark gray light gray Gray White Visual layer quality Good very well very well Good Good medium very well very well Good Good medium Good Good Adhesive strength of the layer very well very well very well Good Good Good Good very well Good Good Good Good Good Coating weight g / m ² 10.0 7.0 7.0 7.6 4.8 4.4 7.4 8.8 16.5 12.0 6.1 6.6 12 Deposition rate at 1 A / dm ² over 1 min, g / m ² 4.0 4.0 3.5 3.4 4.2 4.6 3.6 3.9 - - 3.7 4.1 4.5 example B 11 B 12 B 13 B 14 B 15 B 16 B 17 Ethylene acrylate ** 9.3 23.5 29.7 34.0 65.5 95.2 95.2 Ethylene acrylate type ** B B B B A A A acrylic polymer 6.8 13.2 - - 0.8 - - styrene - - 7.8 - 7.9 14.4 - Amino alcohol content * 2.4 7.2 8.4 6.9 10.1 18.3 18.3 Polymer thickener 11.2 11.2 5.5 - - - - waxes 52.2 43.5 32.5 50.4 20.2 28.2 - Number of waxes 2 3 2 3 2 3 - T _e / T _m of waxes ° C 68 + 148 68 + 143 + 148 85 + 148 68 + 143 + 148 85 + 148 68 + 85 + 148 - water glass 9.2 7.0 6.5 1.8 2.5 3.2 2.5 solid lubricants - - - - - - - PH value 9.4 9.3 9.5 9.5 9.3 9.6 9.8 usable for AZ GZ KFP KS TZ AZ GZ KFP KS TZ AZ GZ KFP KS TZ AZ GZ KFP KSTZ AZ GZ KFP KS TZ KFP KS KFP Degree of deformation max. medium heavy heavy heavy heavy heavy very difficult example B 18 B 19 B 20 B 21 B 22 B 23 Ethylene acrylate ** 6.2 11.8 14.1 18.7 24.1 43.3 Ethylene acrylate type ** C + D C + D C + D C C C acrylic polymer 6.0 - - - 0.2 1.4 styrene 14.3 9.2 11.9 15.9 3.6 2.8 waxes 56.0 29.2 38.2 50.1 67.8 35.6 Number of waxes 3 3 3 3 2 3 T _e / T _m of waxes ° C 68 + 85 + 143 68 + 143 + 148 68 + 143 + 148 68 + 143 + 148 85 + 148 85 + 143 + 148 water glass 4.0 1.8 2.5 5.2 3.4 8.7 solid lubricants - 39.9 graphite 21.0 MoS ₂ - - - PH value 9.2 9.0 9.7 8.5 8.0 9.2 usable for GZ TZ AZ GZ HF KFP AZ GZ HF KFP TZ AZ GZ TZ AZ GZ KFP DZ AZ GZ KFP TZ Degree of deformation max. medium medium - difficult medium - difficult medium - difficult medium - difficult heavy

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 layers are better suited for cold forming than Zn phosphate layers, 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 working 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 lower friction in continuous cold forming than Zn Lead phosphate. In addition to the environmental friendliness of the heavy metal-free phosphate layers and their lighter color with respect to contamination is beneficial. 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.

In the experiments of Table 2 it was found that the content of the lubricant compositions according to the invention can be varied to a large extent on various components. Here, on the one hand, the addition of at least one ionomer, but also of at least one wax and water glass has proven particularly useful. Essentially, the lubricant composition and the coating formed therefrom are more or better usable for heavy 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 due to the content of graphite or molybdenum disulfide.

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

Claims (12)

1. A process for the preparation of metallic workpieces for cold forming first by applying a phosphate layer and then by applying a lubricant layer with a content of organic polymeric material, which is also referred to as a coating in the following, characterised in that the phosphate layer is formed with an aqueous acidic phosphatising solution which contains 4 to 100 g/l of compounds of calcium, magnesium and/or manganese, including the ions thereof, calculated as Calcium, magnesium and manganese, no zinc or less than 30 wt.% of the cations as zinc, and 2 to 500 g/l phosphate calculated as PO₄, and that the lubricant layer is formed by contacting the phosphatised surface with an aqueous lubricant composition,
   which has a content of at least one ionomer from 3 to 98 wt.% of the solids and active substances and as water-soluble, water-containing and/or water-binding oxide and/or silicate has in each case a content of at least one water glass, silica gel, silica sol, silicic-acid hydrosol, silicic-acid ester and/or ethyl silicate from 0.1 to 85 wt.% of the solids and active substances as well as, optionally, also non-ionomeric, organic polymeric material, based on acrylic acid/methacrylic acid, epoxide, ethylene, polyamide, propylene, styrene, urethane, ester(s) thereof and/or salt(s) thereof,
   wherein in each case at least one primary, secondary and/or tertiary amine, especially at least one amino alcohol, is used as the neutralising agent for the neutralisation of the lubricant composition, wherein at least one organic polymeric material is at least partly saponified and/or is at least partly present in the lubricant composition and/or in the coating as at least one organic salt.
2. A process according to claim 1, characterised in that phosphatising is carried out electrolytically with an alkaline-earth content of more than 80 wt.% of all cations.
3. A process according to claim 1 or 2, characterised in that the lubricant layer is formed by contacting the surface with an aqueous lubricant composition, which has a content of at least one water-soluble, water-containing and/or water-binding oxide and/or silicate and/or of at least one amino alcohol as well as a content of organic polymeric material, and that predominantly oligomers, co-oligomers, polymers and/or copolymers based on ionomer, acrylic acid/methacrylic acid, epoxide, ethylene, polyamide, propylene, styrene, urethane, ester(s) thereof and/or salt(s) thereof are used as the organic polymeric material.
4. A process according to one of the preceding claims, characterised in that the coating formed from the lubricant composition has a content of at least one ionomer in the range from 3 to 98 wt.% of the solids and active substances.
5. A process according to one of the preceding claims, characterised in that the lubricant composition and/or the coating formed therefrom have/has a content of at least one water-soluble, water-containing and/or water-binding oxide and/or silicate as well as a content of at least one ionomer, at least one non-ionomeric organic polymeric material based on acrylic acid/methacrylic acid, epoxide, ethylene, polyamide, propylene, styrene, urethane, ester(s) thereof and/or salt(s) thereof and/or at least one wax as well as, optionally, a content of at least one additive.
6. A process according to one of the preceding claims, characterised in that the lubricant composition and/or the coating formed therefrom contain(s) additional organic polymeric components which cannot be regarded as ionomers, such as e.g. oligomers, polymers and/or copolymers based on acrylic acid/methacrylic acid, amide, amine, aramid, epoxide, ethylene, imide, polyester, propylene, styrene, urethane, ester(s) thereof and/or salt(s) thereof.
7. A process according to one of the preceding claims, characterised in that the lubricant composition and/or the coating formed therefrom contain(s) at least one wax, especially in each case at least one paraffin wax, carnauba wax, silicone wax, amide wax, ethylene- and/or propylene-based wax and/or crystalline wax.
8. A process according to one of the preceding claims, characterised in that the lubricant composition and/or the coating formed therefrom contain(s) at least one additive selected from the group consisting of solid lubricants, friction reducers, wear-protection additives, silane additives, elastomers, film-forming auxiliaries, anti-corrosion agents, surfactants, defoamers, flow promoters, biocides, thickeners and organic solvents.
9. A process according to one of the preceding claims, characterised in that the metallic surface of the workpiece or its metal-coated coating is provided with a phosphate layer according to claim 1 or 2 which is made with an aqueous composition based on calcium phosphate, magnesium phosphate, manganese phosphate or corresponding mixed-crystal phosphate, such as e.g. CaZn phosphate.
10. A process according to one of the preceding claims, characterised in that the phosphate layer is formed electrolytically with a current density in the range of 1 and 200 A/dm² and with a voltage in the range from 0.1 to 50 V.
11. A process according to one of the preceding claims, characterised in that the formed workpiece is at least partly cleaned of the remaining coating and/or of the deposits of the lubricant composition after cold forming.
12. A process according to one of claims 1 to 11, characterised in that the coating remains on the formed workpiece permanently after cold forming, at least in part.