Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
  • B05D5/08—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an anti-friction or anti-adhesive surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
  • B32B27/281—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42 comprising polyimides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
  • F16C33/02—Parts of sliding-contact bearings
  • F16C33/04—Brasses; Bushes; Linings
  • F16C33/20—Sliding surface consisting mainly of plastics
  • F16C33/201—Composition of the plastic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
  • F16D69/02—Composition of linings ; Methods of manufacturing
  • F16D69/025—Compositions based on an organic binder
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2475/00—Frictional elements

Definitions

• the invention relates to a two- or multi-layer composite material with a cover layer which contains thermally highly resilient, thermosetting polyimide lacquer, by means of which the components of the cover layer are held together and at the same time the cover layer is firmly connected to the substrate carrying it.
• the invention relates to such a composite material for friction or sliding elements with a metallic substrate, the cover layer forming the friction or sliding layer.
• top layer containing a thermally highly resilient, thermosetting polyimide lacquer is important for creating protected surfaces on layered composite materials of all kinds, in particular for coating metal surfaces and especially those metal surfaces that are subject to friction.
• cover layers by brushing or filling is particularly important.
• composite plain bearings are known in which a layer of perforations or recesses made of polyimide is attached to a steel support body by means of acrylic epoxy adhesive, the perforations or recesses being filled with a mixture of solid lubricant and a bearing metal, as they are are disclosed in DE-OS 20 00 632.
• DE-OS 22 06 400 describes a composite material and a method for its production, the friction or sliding layer contains polyimide resins and / or polyimide lacquer components, which can also consist of polyesterimides and polyamideimides.
• a connection to the metallic support body is made essentially by mechanical clamping.
• the supporting side of the support body is also sintered or a support fabric - for example made of tin bronze - is applied.
• Perforated steel or bronze sheets are also mentioned as supporting bodies.
• the application of a sintered structure or a supporting fabric as an intermediate layer or the use of a perforated steel or bronze sheet is necessary to ensure a sufficiently high connection between the plastic layer to be applied and the carrier material. It is obvious that the additional requirement for the existence of a rough base, which allows mechanical clinging, requires additional work steps and is therefore complex and cost-intensive.
• the sintering structure is sprinkled onto the metallic support body, then ⁇ m has to go through a sintering process which has to be controlled in such a way that sufficient pore space is created which is impregnated with the polyimide resin and / or paint components. Attention must be paid to the viscosity of the mixtures in order to be able to achieve a complete impregnation of the available pore space. However, there are limits to this by adding self-lubricating additives. First, the size of these additives must be based on the dimensions of the available pore space of the primer and vice versa. Furthermore, the viscosity of the mixture increases with the proportion of self-lubricating additives.
• a disadvantage of the described manufacturing process of friction or sliding elements with a very small bending radius is the fact that they can only be cured or hardened to their final thickness and formed after they have been processed. If the hardening or hardening before processing processing or prior to forming into friction or sliding elements with a very small bending radius, detachments, ie, flaking off of the friction or sliding layer must be expected.
• Composite layer materials are also known, the sliding layer of which consists of a fluoropolymer mixture and an additive and which can be mixed with another inorganic or organic substance which improves the sliding properties and is present in powder form.
• the fluorine-containing polymer is in a continuous process
• the disadvantage is the need to use additives which are intended to improve the poor binding behavior of fluorine-containing polymers.
• the object of the invention to provide a two-layer or multi-layer composite material with an improved top layer containing polyimide lacquer, which is characterized by high temperature resistance, high mechanical strength, corrosion resistance and high wear resistance and is easy and inexpensive to apply to the composite material should be.
• the composite material is intended for friction or sliding elements and the cover layer takes on the function of a friction or sliding layer
• the disadvantages of the known polyimide sliding bearings are to be eliminated and, above all, significantly improved friction and sliding properties are to be achieved.
• the object of the invention is achieved in that the matrix of the cover layer is formed by the thermosetting polyimide lacquer and absorbs additives in finely dispersed form therein, and that this cover layer is applied directly to the roughened surface of the substrate.
• the cover layer is to be designed as a friction or sliding layer and is applied directly to the roughened surface of a band-shaped, metallic substrate.
• a particular advantage of the composite material according to the invention is that a two- or multi-layer composite material is produced without an adhesion-promoting layer or a rough base which serves for mechanical clamping.
• the matrix of the friction or sliding layer can advantageously be formed by polyimide which is soluble in solvents, and this matrix, in which a self-lubricating additive or additives is or are finely dispersed therein, is applied directly to the roughened surface of a metallic substrate will.
• the friction or sliding layer which is about 99 to
• polyimide lacquers or the solvent-soluble polyimides can advantageously be substances from one or more of the following groups of polyimides:
• the polyimide lacquer can be a solvent-soluble polyimide or a polyester crosslinked via tris (2-hydroxyethyl) isocyanurate (THEIC).
• TEEIC 2,3-hydroxyethyl) isocyanurate
• the self-lubricating additive can advantageously be a low molecular weight PTFE in powder form, the average molecular weight of which is between 35,000 and 100,000, the average grain size of the low molecular weight PTFE being between 5 and 7 ⁇ m.
• the thickness of the friction or sliding layer can advantageously be between 0.05 and 0.5 mm, preferably between 0.07 and 0.2 mm.
• the metallic substrate can be formed from steel according to DIN 1624, aluminum, an aluminum alloy, aluminum-plated steel or copper-containing materials, the metallic substrate having a thickness between 0.5 and 2.0 mm.
• the production of the composite layer material according to the invention can be carried out in a continuous pass, the following process step being shown in a particularly advantageous manner.
• the self-lubricating additive which is in powder form, is intimately mixed with the polyimide lacquer forming the matrix and homogenized to a low viscous to pasty state, the mixture thus prepared being applied in the desired coating thickness in an appropriate amount to the metallic substrate and fritted onto it can be.
• a latent solvent preferably diraethylformamide, the addition of dimethylformamide being 2 to 10% by volume, preferably 4 to 6% by volume.
• the mixture provided with a latent solvent can be used Spraying, brushing or rolling are applied to the metallic substrate, the metallic substrate advantageously being able to be heated inductively to the temperature in order to frit the friction or sliding layer against the metallic substrate in an MF oven.
• the latent solvent contained in the friction or sliding layer that has been fritted can be volatilized in a subsequent heating section.
• the mixture of polyimide lacquer and low molecular weight PTFE applied to the metallic substrate can be fully hardened in a continuous furnace which can be regulated in its top and bottom heat, the initial temperature of the substrate being able to be a maximum of 253 ° C.
• the latter in order to form the maximum crystallization of the friction or sliding layer, the latter can be cooled in a controlled manner following the hardening and then wound up into a roll for further processing.
• the process according to the invention has the advantage that the metallic support material can be coated directly with the low-friction, wear-resistant and temperature-resistant material in a continuous process without complex intermediate layers with optimal adhesion.
• the demand for a fast and economical production process is taken into account in that the processing times are extremely short and sufficient accuracy when applying the friction or sliding layer helps to avoid dimensional reworking.
• After the strip provided with a friction or sliding layer has cooled in a controlled manner, it is wound up into a roll without additional thermal or mechanical aftertreatment and is suitable for further processing to conventional sliding bearing elements.
• Conventional two-layer composite materials with the structure of metallic supports / plastic suffer from non-cutting shaping by, for example, rolling, pressing or bending, irreversible damage to the bond between the substrate and the coating.
• Reshaping the two-layer or multilayer material according to the invention for example by rolling, surprisingly does not damage the layer composite.
• a two-layer material can preferably be produced with a support material made of steel DIN 1624, quality St3, preferably St4.
• a support material made of steel DIN 1624, quality St3, preferably St4.
• other metallic support materials for example aluminum or aluminum alloys and aluminum-plated steel or copper-containing materials, can also be considered.
• the thickness of the metallic support materials used is arbitrary, but should preferably be in the range from 0.5 mm to 2.0 mm.
• a polyester crosslinked via tris (2-hydroxyethyl) isocyanurate (THEIC) is preferably used as the polyimide lacquer. This thermally highly resilient, heat shock-resistant, low-friction and insensitive to mechanical stress is mixed homogeneously with low-molecular PTFE, which is available in powder form and reduces friction and wear.
• the homogeneous mixture to be applied to the support layer is between 0.05 mm and 0.5 mm thick, preferably between 0.07 mm and 0.2 mm.
• the addition of the wear-reducing, slip-improving PTFE in powder form with a grain size of 0.005 mm to 0.007 mm and a volume fraction of 1 to 40%, preferably 10 to 20%, is mixed with the polyimide lacquer, for example polyesterimide.
• the polyimide lacquer for example polyesterimide.
• a latent solvent for example dimethylformamide
• a latent solvent preferably dimethylformamide
• the pretreatment of the metallic support layer is preferably carried out by means of blasting, brushing or grinding, that is to say mechanically.
• Another way of pretreatment is by etching, that is, by chemical means. This treatment for increasing the specific surface in a mechanical and / or chemical manner is followed by cleaning the surface to be coated by known solvents.
• this matrix 3, consisting of polyester imide there are low molecular weight PTFE particles as a self-lubricating additive 4 finely dispersed.
• the grain size of these PTFE particles 4 is between 5 and 7 ⁇ m.
• the fat. of the metallic substrate 1 is 0.2 to 2.5 mm in the manufacture of plain bearings, for example for use in pumps, carburetors or shock absorbers.
• the thickness of the friction or sliding layer 5 is between 0.07 and 0.2 mm.
• 1624 or St4 is treated continuously by blasting, brushing or grinding and / or etching and subsequent cleaning or degreasing with preferably organic solvents. This is followed immediately by coating with a mixture of polyester imide and low molecular weight PTFE wax, particle size approx. 5 ⁇ m to 7 ⁇ m, average molecular weight 35,000 to 100,000. The best results were achieved with a statistical wear test (pin / roller test device) with a maximum of 21% by volume PTFE added.
• the application of the friction or sliding layer takes place via an application knife (alternative: roller coating), this being set so that a uniform coating takes place over the entire range.
• This form of strip coating compensates for any differences in thickness of the support layer, so that an additional work step for thickness regulation is not necessary.
• the material mixture is fritted onto the substrate in a preheating oven, an MF oven.
• the solvents contained in the friction or sliding layer are evaporated in a subsequent heating section.
• the coating composition is cured in a circulating continuous system.
• a closed, smooth and pore-free coating is only created by the described sequence of the coating process and the design of the ovens.
• the exit temperature of the strip described is 250 C at the end of the continuous furnace. Subsequent to the continuous furnace, there is slow, controlled cooling, which causes a high degree of crystallization of the coating.
• the two-layer composite material is wound up into a roll without any dimensional checks, such as rolling or milling, and is suitable for further processing of friction and sliding elements.
• polyesterimide Comparative wear tests on test platelets, produced after the coating according to the invention polyesterimide and different volume fractions of low molecular weight PTFE compared to a coating without the addition of PTFE are listed below.
• the surface of the preferably metallic support layer to be coated with the sliding or friction layer according to the invention can be roughened by customary mechanical processes such as blasting, brushing or grinding. Chemical treatment by etching is also possible.
• the coating material according to the invention with e.g. a composition of 93 parts by volume of polyester imide and 7 parts by volume of low molecular weight PTFE is described below.
• the mixing process takes place in a high-speed stirrer at a speed of ⁇ 4000 rpm.
• the initial viscosity at 23 ° C according to DIN 53211 for the polyesterimide is 90 s + 5%.
• the coating of the material according to the invention or the production or application is preferably carried out via an adjustable spreading bar or an application doctor.
• the coating of a correspondingly pretreated support layer with a material according to the following composition is described.
• Example 2 The composition of the friction or sliding layer consists of 79 parts by volume polyester imide and 21 parts by volume low molecular weight PTFE.
• cover layer can also be applied to the strip-shaped substrate in a continuous process.
• the top layer can be put together in any desired special requirements, for example as a friction or. Sliding layer.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)
• Sliding-Contact Bearings (AREA)
• Lubricants (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6086586

Family Applications (1)

Country Status (5)

Cited By (12)

Families Citing this family (4)

Citations (8)

• 1979
  • 1979-11-22 DE DE19792947025 patent/DE2947025A1/de not_active Withdrawn
• 1980
  • 1980-10-23 WO PCT/DE1980/000159 patent/WO1981001375A1/de not_active Ceased
  • 1980-10-23 BR BR8009010A patent/BR8009010A/pt unknown
  • 1980-10-23 GB GB8122404A patent/GB2075368B/en not_active Expired
  • 1980-10-23 JP JP50248180A patent/JPS56501641A/ja active Pending

Patent Citations (8)

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