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
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/14—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies
  • B05D7/16—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies using synthetic lacquers or varnishes
• • 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
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/10—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by other chemical means
  • B05D3/102—Pretreatment of metallic substrates

Definitions

• the invention relates to a method for applying F luorkohlenwasserstoffharzen on stainless steel.
• the object of the invention is to remedy the known, in particular the aforementioned disadvantages, and to provide a method for applying fluorocarbon resin to stainless steels, which leads to firmly adhering coatings with high weather resistance and flatness as well as high dust and dirt repellency in a simple process.
• the object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that an aminosilane coupling agent is first applied to the stainless steel in an amount of 1 to 500 mg / m 2 and then the fluorocarbon resin.
• an aminosilane coupling agent is applied in an amount of 3 to 50 mg / m 2 .
• the invention is not limited to the treatment of certain stainless steels, but is universal e.g. applicable for martensitic, ferritic and austenitic stainless steels.
• Aminosilane coupling agents are known compounds and have the general formula (where X is, for example, halogens, same or different lkoxy- A and alkyl groups and the (CH 2) n chain may be interrupted by secondary amine groups see. for example Ullmann, Encyklopadie der techn. Chemie, 4th Ed., Vol. 21 , Pages 496 ff., In particular page 497).
• aminosilane coupling agents have the formula Although other silane coupling agents, such as vinyl, methacryloxy and epoxysilanes, also result in a certain improvement in adhesion, aminosilanes are particularly outstanding when applying fluorocarbon resins to stainless steel.
• the aminosilane coupling agents can be applied electrostatically by dipping or spraying, by roller or brush application.
• a dilute solution is simply dried, the degree of dilution of which is selected such that 1 to 5 g / m 2 of solution can be applied .
• the drying of the solution only serves to remove the solvent. This can be done in air if sufficiently low-boiling solvents are used. In general, however, heating to a temperature of 80 to 200 ° C. for a period of 10 seconds to 30 minutes is recommended, depending on the solvent and the temperature selected.
• the application of the aminosilane adhesion promoter in the required amount is important insofar as sufficient adhesion mediation cannot be achieved with amounts below 1 mg / m. With application quantities of more than 500 mg / m2, the adhesion-improving effect is reversed, i.e. the mediation is getting worse again.
• the method according to the invention is suitable for all fluorocarbon resins on the market. These resins can be applied in the form of lacquer or paint, but also in the form of a previously created film.
• Stainless steel sheets of quality SUS 304 (JIS) were first ground (hair-line finished), then degreased with a strong alkaline cleaner based on silicate Rinsed water and dried.
• a batch of these sheets was treated with a solution of aminosilane coupling agent which was obtained by dissolving 1 part by weight of gamma-aminopropyltriethoxysilane ( H 2 NC 3 H 6 SI (OC 2 H 5 ) 3 ) in 99 parts by weight of water a content of 1 wt .-% ethanol was obtained.
• the application was carried out by immersion, a liquid film of 1.5 g / m 2 adhering to the stainless steel surface. After drying at 100 ° C. for 3 minutes in a forced air oven, an aminosilane coating with a layer weight of 15 mg / m 2 resulted.
• experiment 11 the same aminosilane coupling agent as in experiments 1 to 5 was applied, but from a solution so diluted that a layer weight of only 0.5 mg / m 2 resulted.
• the type of application and the subsequent paint treatment were identical to that of Example 4.
• a chromate coating was produced instead of the aminosilane coupling agent.
• a conventional chromating solution with a silica content and a total concentration of 100 g / l was used for this.
• the chromating solution was dried at 130 ° C for 2 minutes.
• the layer weight was 30 mg / m 2 .
• the subsequent painting was done as with
• the paint adhesion was determined using 6 methods.
• Examples 6 and 7 illustrate that the layer weight of the aminosilane coupling agent applied is of essential importance. Particularly under the more difficult test conditions of the crosscut / Erichsen test and the water test, the optimal results can no longer be achieved if the layer weights are too low or too high.
• the process according to the invention makes it possible to apply fluorocarbon resins with excellent adhesion to stainless steel.
• the process according to the invention gives a considerable improvement in the adhesion of fluorocarbon resins, and also has a high gloss on previously colored stainless steel surfaces. This extends the area of application of stainless steel and can also extend to products with an aesthetic appearance.
• Another advantage of the invention is that the previously roughened stainless steel surface, e.g. by grinding or blasting, for the purpose of improving the paint adhesion, so that, for example, in the production of facade or roof elements for the construction sector, a considerable manufacturing rationalization effect can be achieved.
• no special precautionary measures are required at the workplace or in the other handling of the process products.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Chemical Treatment Of Metals (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=11867622

Family Applications (1)

Country Status (3)

Cited By (6)

Families Citing this family (8)

Citations (2)

• 1986
  • 1986-01-28 JP JP61014669A patent/JPH0657872B2/ja not_active Expired - Fee Related
• 1987
  • 1987-01-24 DE DE19873702141 patent/DE3702141A1/de not_active Withdrawn
  • 1987-01-24 EP EP87100986A patent/EP0231001A1/fr not_active Withdrawn

Patent Citations (2)

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