DE3244714A1 - Process for the preparation of a composite layered material having a polysulphone-based matrix in the functional layer - Google Patents

Abstract

Composite layered materials having a polysulphone-based matrix in the functional layer are only suitable as sliding or frictional elements or for the production of sliding or frictional elements if the adhesion of the functional layer to the metallic substrate is substantially improved compared with known composite layered materials. This is achieved in the production process for composite layered materials of this type in that the metallic substrate is roughened on its surface carrying the functional layer by blasting with corundum, and the layer applied to this roughened surface is warmed in order to expel the solvent by heating the metallic substrate. An essential improvement in the load-bearing capacity, the abrasion resistance and at the same time the adhesive strength of the functional layer can be achieved if, in addition to the fillers which determine or affect the tribological behaviour, glass powder and/or mica, in particular synthetic mica, in a grain fraction with 100% < 40 mu m is mixed into the solution of polysulphone-based polymers during the production process.

Description

The invention relates to a method for producing

development of a composite layer material with one on a metallic Functional layer attached to the substrate, which is essentially made of thermally loadable Polymer from the group of polysulfones has built-up matrix, in which Process of dispersion of the tribological behavior of the functional layer determining or influencing fillers in a solution of polymer Poly-sulfone-based in solvent that can be expelled under the action of heat on the through Roughening the prepared surface of a metallic substrate in the desired layer thickness is applied, after which the solvent from this layer under the action of heat driven out and after the complete removal of the solvent the remaining Polysulfone is sintered together to form a matrix including the fillers.

From DE-AS 26 33 940 are a coating dispersion and coated therewith Objects known. This known coating dispersion is said to be a thermoplastic, aromatic polyether sulfone as a solution or dispersion with a particle size of less than 25 µm in a diluent, this solution or dispersion PTFE particles can be admixed. Among other things, this coating dispersion is intended for formation non-adhesive, low-friction coating of many objects. However it has been found that one produced with this known coating dispersion Coating on metallic substrates does not achieve sufficient adhesive strength lets to such a composite layer material as sliding or friction elements or to use for the production of sliding or friction elements.

In contrast, the object of the invention is to provide a thermally and mechanically in particular to create dynamically highly resilient composite laminate material, in particular a two-layer composite material in which the functional layer is essentially a Matrix composed of thermally resilient polymers from the group of polysulfones contains and has increased adhesive strength on a metallic substrate. That The manufacturing process should be simple and the composite laminate should be good and be reliably machinable or further processable, in particular good deformation behavior exhibit.

It has surprisingly been shown that this object according to the invention is achieved in that the roughening of the surface carrying the functional layer the metallic substrate is made by blasting with corundum and that the layer applied to the roughened surface of the metallic substrate heated to drive off the solvent by heating the metallic substrate will. The composite laminate produced according to the invention becomes a considerable Meet the requirement profile and is characterized by good adhesion to the metallic Substrate, thermal resistance with mechanical-dynamic loads with increased Temperature, good friction and sliding behavior, good resistance to cavitation.

It has surprisingly been found that the desired adhesive strength the functional layer on the metallic substrate only by roughening the substrate surface by blasting and exclusively by using corundum as a blasting agent is attainable.

Particularly advantageous results can be achieved when polysulfone or polyether sulfone with grain fraction 100% <25 µm to the sixfold Amount of solvent given and dissolved in this with stirring, the solvent is one of the following substances or a mixture which one or more of the following Substances contains: N-methylpyrrolidone, methylene chloride-1,2-trichloroethane, dimethylformamide. It has been found that one based on such a solution or Functional layer formed by dispersion, particularly good adhesion to the layer formed by blasting surface of a metallic substrate prepared with corundum, if the metallic substrate is heated to drive off the solvent.

Surprisingly, it has been found to be particularly advantageous in the solution of polymers based on polysulfone in addition to the tribological Fillers that determine or influence behavior or glass powder and / or mica, in particular synthetic mica, in a grain fraction 100% <40 um. The glass powder and / or deGlimmer, especially the synthetic Glimemr in an amount between 5 and 15% by volume, preferably 8% by volume, based on the Solids content are mixed in. As was surprisingly found, there is apparently a functional interaction between the roughening of the substrate surface by blasting with corundum and adding glass powder and / or mica, in particular synthetic mica in the functional layer. When using both Features particularly high load-bearing capacity and wear resistance in connection with particularly good adhesion of the functional layer is achieved, with the free surface the functional layer is free of any sticky properties.

In the process according to the invention, preference is given to that of solvent freed polysulfone-based polymers for sintering together to form the matrix from the side of the metallic Substrates to a temperature of at least 460 ° C and heated for a period of 60 seconds to a maximum of 360 seconds.

kept at this temperature.

The process according to the invention can be carried out continuously in one pass tape-shaped substrate are carried out.

Such a continuous process flow is as follows: Polyether sulfone or polysulfone is used in solvents such as N-methylpyrrolidone, methylene chloride-1,2-trichloroethane and / or dimethylformamide dissolved, with the addition of the polymer material to 6 times the amount of the solvent is achieved by stirring a solution. The particle size fraction of the polymer powder used is 100% below 25 μm.

After completing one of the approaches (solution) described above the fillers necessary to influence the tribological behavior in the required amount dispersed in the solution.

After completion of the "solution" or dispersion this is in one continuous strip layer process on, for example, metallic supports in strip form applied to manufacture semi-finished products from a layer composite, from which then Bearing shells, bearing bushes, thrust washers and others known forms of bearing elements are manufactured.

The continuously running carrier tape is coated via an application squeegee by brushing on.

However, all conceivable coating methods such as Dipping, spraying, spatula, etc., applicable, since the viscosity of the solution or the dispersion can be varied within wide limits, so that for each individual Coating system can be adjusted to a suitable viscosity. The substrate tape, in particular Steel strip is blasted with prior to coating To treat corundum (A1203). This resulted in adhesive strength values in mandrel bending tests, those with any other roughening and also with blasting the substrate surface were by far not achievable with other known blasting media.

After applying the solution or dispersion to the pretreated The volatile component of the coating is removed from the substrate surface. this takes place by inductive heating of the metallic carrier material (substrate) until the solvent has completely evaporated.

It was surprisingly and unexpectedly found that in one Heating of the coil coating, which is not over the carrier material or from the Side of the carrier material, for example when heated by radiant heaters, the coating is peeled off again in the form of a film after the sintering process has taken place could be.

After the solvents have evaporated, the belt runs through it a sintering section, with a temperature of at least 4600C within the sintering section must be achieved, which in turn via the carrier material on the layer composite acts for at least 60 seconds to a maximum of 360 seconds.

After going through the steps described, the tape can after After cooling, it is wound up by means of compressed air or another cooling medium and / or further processed.

In the following some examples are given, which are after the one described Describe the materials produced and tribologically on a pin / roller test device with regard to various features such as wear resistance and Friction behavior, were investigated.

Example 1: A metallic carrier (steel St4, DIN 1624) is through Blasting pretreated with Al203 abrasive and with polysulfone solution as described coated to a layer of 100 µm. No fillers were used to improve properties used in terms of tribological behavior.

Test conditions sliding speed: 100 min 1, corresponding to 0.523 m / s stat. Load: approx. 700 N spec. Load: 8.9 N / mm2 Test flake: 10 mm Roll # of the counter-rotation: 100 mm p.v. value: 4.68 N / mm2. m hardness: 60 HRC Rt: 2.78 um Ra: 0.24 um Rz: 1.78 um Using the test conditions listed, the following Results obtained: Temperature of the wear roller: Temperature of the test specimen: 100 ° C Frictional torque in N / mm after 5 min: 25 Wear in around after 6 min .: 100 Example 2: Production as described in Example 1, but instead of polysulfone Polyether sulfone used.

Wear roller temperature: Test specimen temperature: 940C Frictional torque in N / mm after 5 min: 19 Frictional torque in N / mm after 10 min: 20 Wear in around after 11 min .: 100 Example 3: Similar to example 1, but with Fraction of fillers made of low molecular weight PTFE, particle size about 5 to 7 µm with an average molecular weight of 35,000 to 100,000, as well as metallic Lead with a grain size of 100% <40 μm, in a proportion of 20% by volume each on the polymer matrix.

Temperature of the wear roller after the test run 510C temperature of the test specimen: 720C frictional torque in N / mm after 5 min: 8.1 frictional torque in N / mm after 10 min: 8.1 frictional torque in N / mm after 15 min: 7.0 frictional torque in N / mm after 20 min: 8.5 frictional torque in N / mm after 25 min: 9.0 frictional torque in N / mm after 30 min: 9.2 der Wear of the test specimen was 60 μm after a running time of T = 30 min.

Example 4: As Example 3, but polyether sulfone with 20% by volume of PTFE, 20 vol% lead.

Temperature of the wear roller after 30 min: 530C Temperature of the test specimen: 80 ° C Friction torque in N / mm after 5 min: 7.9 Friction torque in N / mm after 10 min: 9.1 Friction torque in N / mm after 15 min: 9.8 frictional torque in N / mm after 20 min: 10.0 frictional torque in N / mm after 25 min: 11.0 frictional torque in N / mm after 30 min: 12.0 wear after a running time of 30 min: 98 um Example 5: Polysulfone with 14 vol .-% PTFE, 8 Vol .-% lead, 8 vol .-% glass powder (glass powder in a grain fraction 100% <40 µm).

Temperature of the wear roller: 56 ° C Temperature of the test specimen: 65 ° C Friction torque in N / mm after 5 min: 7.9 Friction torque in N / mm after 10 min: 8.0 Friction torque in N / mm after 15 min: 8.2 frictional torque in N / mm after 20 min: 8.0 frictional torque in N / mm after 25 min: 8.5 frictional torques in N / mm after 30 min: 8.9 The wear was 9 μm after 30 min.

Example 6: Polyether sulfone with the composition as in Example 5.

Temperature of the wear roller: 49 ° C Temperature of the test specimen: 510C Frictional torque in N / mm after 5 min: 8.2 Frictional torque in N / mm after 10 min: 7.5 Frictional torque in N / mm after 15 min: 7.2 frictional torque in N / mm after 20 min: 7.2 frictional torque in N / mm after 25 min: 7.4 frictional torque in N / mm after 30 min: 7.8 The wear was 8.3 after 30 min.

Example 7: As example 5, but the glass powder fraction was through Mica replaced (mica from Omya with the designation MIKA M).

Temperature of the sealing roller: 49 ° C Temperature of the test specimen: 52 ° C Friction torque in N / mm after 5 min: 7.8 Friction torque in N / mm after 10 min: 7.6 Friction torque in N / mm after 15 min: 7.3 frictional torque in N / mm after 20 min: 7.0 frictional torque in N / mm after 25 min: 6.8 frictional torques in N / mm after 30 min: 6.8 The wear was 4.5 after 30 min.

Example: As Example 7, but polyether sulfone as the matrix material.

Wear roller temperature: 490C Test specimen temperature: 56 ° C Friction torque in N / mm after 5 min: 8.0 Friction torque in N / mm after 10 min: 7.8 Friction torque in N / mm after 15 min: 7.7 frictional torque in N / mm after 20 min: 7.6 frictional torque in N / mm after 25 min: 7.5 frictional torque in N / mm after 30 min: 7.5 wear after 30 min 4.5 µm.

By adding fillers, which are under the listed Examples used is the bond between carrier material and plastic has not been adversely affected. As has surprisingly been shown, works Mica has a very beneficial effect on its behavior under tribological stress the end.

While both polysulfone and polyether sulfone are only unsatisfactory Show wear resistance, this is particularly significant due to mica improved.

Achieving a two-layer composite with good thermal Behavior can also be used at temperatures> 100 ° C to 2000C, is supported by a Layer composite achieved according to the manufacturing process and composition described.

Whereby partly the composite material due to the restriction to relative thin sliding and friction layers of approx. 50 to 300 µm, preferably between 100 and 200 µm, withstands cavitational loads such as those found in shock absorbers and pumps and due to the metallic lead constituents in the polymer matrix and also the relatively small plastic layer thicknesses can cope with temperature peaks.

Adequate adhesion is achieved through the process steps described brought about, the adhesive forces acting, especially when heated from the substrate, come fully into use.

The layer structure of an exemplary embodiment of the layer composite material is shown in the drawing.

A carrier material 1, for example made of steel, is provided here, which by blasting with corundum (grain size 100% 1mm, 78% 0.5mm, 22% 0.2mm) a Roughening and enlargement of the surface 2 is obtained on the low mechanical Clamping but high adhesive effect, the polymer matrix 3 made of a polysulfone or polyether sulfone is bound. In the polymer matrix 3 there are finely dispersed fillers 4, which have a positive influence on the tribological behavior. Also contains the matrix 3 in fine distribution the load-bearing capacity and wear resistance of the Particles 5 of glass, mica or synthetic mica increasing the functional layer.

Process for the production of a composite layer material with a matrix based on polysulfone in the functional layer List of reference symbols 1 carrier material (Substrate) 2 roughened surface of 1 3 polymer matrix 4 finely dispersed fillers for tribological behavior 5 particles to increase the load-bearing capacity and wear resistance (Glass, mica, synthetic mica) Blank page

Claims (5)

Process for the production of a composite layer material with a matrix Polysulfone-based in the functional layer of a composite layer material with one attached to a metallic substrate Functional layer, which is made up essentially of thermally resilient polymers the group of polysulfones has built-up matrix, in which method a Dispersion of or determining the tribological behavior of the functional layer influencing fillers in a solution of polymers based on polysulfone in Solvent which can be expelled under the action of heat to the solvent prepared by roughening Surface of a metallic substrate applied in the desired layer thickness is, after which the solvent is driven out of this layer under the action of heat and after the complete removal of the solvent, the remaining polysulfone is sintered together to form a matrix including the fillers, characterized in that that the roughening of the functional layer bearing surface of the metallic Substrate by blasting is made with corundum and that the layer applied to the roughened surface of the metallic substrate heated to drive off the solvent by heating the metallic substrate will. 2) Method according to claim 1, characterized in that polysulfone or polyether sulfone with a grain fraction of 100% <25 µm to 6 times the amount of solvent given and is dissolved in this with stirring, the solvent being one of the the following substances or a mixture that contains one or more of the following substances contains: N-methylpyrrolidone, methylene chloride / 1,2-trichloroethane, dimethylformamide. 3) Method according to claim 1 or 2, characterized in that in the solution of polymers based on polysulfone in addition to the tribological Fillers that determine or influence behavior or glass powder and / or mica, in particular synthetic mica, mixed in in a grain fraction 100% <40 µm will. 4) Method according to claim 3, characterized in that the glass powder, the mica and / or synthetic mica in an amount between 5 and 15% by volume, preferably 8% by volume, based on the solids content, is mixed in. 5) Method according to one of claims 1 to 4, characterized in that that the desolventized polysulfone-based polymer for sintering together to the matrix from the side of the metallic substrate to a temperature of at least 4600 C and heated for a period of 60 seconds to a maximum of 360 seconds this temperature is maintained.