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
  • B05D7/50—Multilayers
  • B05D7/52—Two layers
  • B05D7/54—No clear coat specified
  • B05D7/546—No clear coat specified each layer being cured, at least partially, separately
• • 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
  • B05D3/02—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 baking
  • B05D3/0209—Multistage baking
• • 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
  • B05D2202/00—Metallic substrate
  • B05D2202/20—Metallic substrate based on light metals
  • B05D2202/25—Metallic substrate based on light metals based on Al
• • 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
  • B05D2701/00—Coatings being able to withstand changes in the shape of the substrate or to withstand welding
  • B05D2701/10—Coatings being able to withstand changes in the shape of the substrate or to withstand welding withstanding draw and redraw process, punching
• • 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
  • B05D3/12—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 mechanical means
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
  • Y10T428/256—Heavy metal or aluminum or compound thereof

Definitions

• the invention relates to the fields of chemistry, mechanical engineering and materials technology and relates to coated formed aluminum semi-finished products and / or components which are coated with a two-stage curable / crosslinkable coating agent for a stable coating and a process for their production.
• curable compositions preferably used for the production of powder coatings and their processes for the production and processing, which are used specifically for multi-stage reactions and preferably for two-stage reactions. These masses harden in multi-stage reactions, the first stage being catalyzed at low temperatures.
• a disadvantage of the known coatings is that essentially no dimensionally stable coating can be achieved.
• the object of the invention is to provide and produce coated, formed aluminum semi-finished products and / or components which are still formable as semi-finished products and at the same time retain a closed coating and are cured at higher temperatures, so that a closed coating is also obtained in the end.
• coated formable semi-finished aluminum products and / or components according to the invention are coated with an at least two-stage curable / crosslinkable coating agent in the form of a melt coating composition or as a powder coating or as a coating dispersion or as a solvent system and at most partially cured / partially crosslinked.
• the coating film formed is elastic and is essentially present as a closed coating film during subsequent forming processes.
• the coated aluminum semifinished products and / or components according to the invention are provided with at least one, in at least one second reaction step after a forming process, essentially hardened / crosslinked coating film, the curing / crosslinking taking place under the conditions of the recrystallization of the aluminum (alloy).
• the coated formable aluminum semifinished products and / or components are in the form of aluminum sheet (s) or aluminum tube (s) or aluminum sandwich semifinished product (s) in sheet or tube form made of formable aluminum (alloys) that can be formed at temperatures below 150 ° C .
• the coated formable semi-finished aluminum products and / or components are coated completely or partially or on one side or inside or outside with the coating film.
• the coated formable semi-finished aluminum products and / or components are provided with at least one further layer. It is also advantageous if, in the case of the coated formable semi-finished aluminum products and / or components, the adhesion is achieved by adhesive interactions and / or by chemical, preferably covalent bonds. It is also advantageous if the coated formable
• At least one coating agent consists of a binder system consisting of one or more resin and
• Hardener component (s) with or without additives (s) and / or catalysts (s) is composed.
• Coating agent coated in the form of melt coating composition or powder coating or coating dispersion or solvent system The layer (s) are filmed and partially hardened / partially crosslinked in a first stage and substantially hardened / crosslinked in an at least second stage during and / or after at least one forming process.
• the first stage for filming and partial curing / partial crosslinking is advantageously carried out at temperatures ⁇ 150 ° C.
• Partial curing / partial crosslinking of the layer set a temperature / time regime.
• partial curing / partial crosslinking is carried out thermally and / or photochemically and / or radiation-chemically.
• coated formed aluminum semifinished products and / or components are coated with at least one further layer and filmed in the at least second stage and cured / crosslinked together with the first (lacquer) layer.
• the essence of the invention consists in the production of coated formed aluminum semi-finished products and components, which according to the Aluminum semi-finished products are coated and filmed in a thermal process and partially hardened / partially crosslinked.
• the partial hardening / partial crosslinking of the layer for example thermally and radiation-chemically or only thermally, has such a mechanical stability that these semi-finished products can be intermediately stored without problems and processed further at a later point in time.
• a corresponding temperature / time regime must be observed in the first stage of filming and partial hardening / partial crosslinking. It applies that shorter reaction times should be selected at higher temperatures. At low temperatures, for example, partial curing / partial crosslinking can be carried out using radiation chemistry.
• the elasticity of the partially hardened / partially crosslinked (lacquer) layer can be set by criteria - firstly by the composition of the binder system and secondly by the degree of partially hardening / partially crosslinking, which can be determined via DSC measurements.
• the composition of the binder system in particular elastic structural elements can be integrated in the resin component.
• the formed (lacquer) film is thus present as a closed (lacquer) film during or after the shaping process, as a result of which additional process steps in particular can be omitted.
• top coats for example top or color layers or sliding layers
• top or color layers or sliding layers can be applied, which can also be cured / crosslinked in the second stage at temperatures above 130 ° C.
• the adhesion between the formable aluminum semi-finished products and components and the layer and between the layers is advantageously achieved in addition to the adhesive interaction through chemical bonds. Further improvement in adhesion is achieved by forming covalent bonds. Due to the partial hardening / partial crosslinking of a layer, functional and / or reactive groups are retained on the surface, which form a covalent bond with the functional and / or reactive groups of a further layer.
• the invention is explained in more detail below using several exemplary embodiments.
• the compounds (A) and (B) are homogenized at a melt temperature of 90 ° C.
• the compounds (E), (D) and (C) are added in succession to this mass.
• compositions of the example mixtures are given in Table 1.
• the homogenized masses are quenched by introduction into liquid nitrogen. These masses are further processed into a coating powder in a (laboratory) grinding plant with sifter.
• the coating powder is applied to an aluminum sheet by means of powder coating and filmed in a forced air oven at 140 ° C. for 15 minutes and partially hardened / partially crosslinked. It was determined by DSC measurements that no further reactions from uretdione to allophanate were detectable under isothermal measurement conditions.
• the coated aluminum sheet is thermoformed into a cup as a model component at room temperature. No cracks or layer damage occurred and there was a closed coating film. After applying a clear powder coating as a top coat, this model component is cured / crosslinked in a forced air oven at 170 ° C in 20 minutes. At the same time, the rigidity of the component increased due to recrystallization.
• the degree of crosslinking of the lacquer layers is characterized by differential scanning calorimetry (DSC). In the dynamic DSC scan from 40 to 220 ° C at a heating rate of 10 K / min, no more reaction peak was found. The results are shown in Table 2.
• Example 1 in the tables is the comparative example analogous to commercial coating compositions, in which after the coating and partial hardening / partial crosslinking, the semi-finished aluminum product can no longer be formed.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Paints Or Removers (AREA)
• Laminated Bodies (AREA)
• Chemical Treatment Of Metals (AREA)
• Polishing Bodies And Polishing Tools (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2002
  • 2002-03-12 AU AU2002250819A patent/AU2002250819A1/en not_active Abandoned
  • 2002-03-12 US US10/471,582 patent/US20040105972A1/en not_active Abandoned
  • 2002-03-12 AT AT02719679T patent/ATE399602T1/de active
  • 2002-03-12 EP EP02719679A patent/EP1372872B1/fr not_active Expired - Lifetime
  • 2002-03-12 ES ES02719679T patent/ES2309160T3/es not_active Expired - Lifetime
  • 2002-03-12 DE DE50212437T patent/DE50212437D1/de not_active Expired - Lifetime
  • 2002-03-12 DK DK02719679T patent/DK1372872T3/da active
  • 2002-03-12 CA CA002440998A patent/CA2440998A1/fr not_active Abandoned
  • 2002-03-12 DE DE10211512A patent/DE10211512B4/de not_active Expired - Fee Related
  • 2002-03-12 WO PCT/DE2002/000924 patent/WO2002072285A2/fr active IP Right Grant

Non-Patent Citations (1)

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