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
• • 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
  • B05D3/06—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 exposure to radiation
  • B05D3/061—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 exposure to radiation using U.V.
  • B05D3/065—After-treatment
  • B05D3/067—Curing or cross-linking the coating
• • 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
  • B05D5/005—Repairing damaged coatings
• • 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
  • B05D7/56—Three layers or more
  • B05D7/57—Three layers or more the last layer being a clear coat

Definitions

• the invention relates to a method for multilayer Refinishing of substrates with a filler layer and a top coat layer, which application is in the field of vehicle and Vehicle parts painting.
• Multi-layer vehicle refinishes generally consist of one optionally pre-coated substrates applied filler layer and one Top coat consisting of a color and / or effect basecoat and one transparent clear coat. However, it can also be a top coat act from a pigmented one-coat topcoat.
• UV curable One-component (IC) filler coating agent for refinishing.
• IC UV radiation curable One-component
• UV curable Components are only used in so-called reactive thinners. It is tripropylene glycol triacrylate and trimethylpropane triacrylate.
• EP-A-000 407 describes radiation-curable coating compositions based on an OH-functional polyester resin esterified with acrylic acid, one Vinyl compound, a photoinitiator and a polyisocyanate.
• a 1st Curing step the radiation is cured by means of UV light and in a second
• the OH / NCO crosslinking gives the coating its final hardness.
• the second hardening step can take place at 130 - 200 ° C or over several days Room temperature. The final hardness is only reached after several days.
• EP-A-247 563 describes clearcoats curable by means of UV radiation Basis of a poly (meth) acryloyl functional compound, one Polyolmono (meth) acrylates, a polyisocyanate, a light stabilizer and one Photoinitiators. Some of the radiation-curable binders still contain here Hydroxy functions that can react with the existing polyisocyanate and offer an additional hardening option.
• EP-A-540 884 describes a method for producing a Multi-layer painting for automotive serial painting by application of a Clear coat on a dried or crosslinked basecoat, the Clear lacquer coating agent by radical and / or cationic polymerization contains curable binders, and curing by means of high-energy radiation is carried out. After the clear coat has been irradiated, the stoving process takes place. where basecoat and clearcoat together in e.g. Be baked at 80 - 160 ° C.
• the object of the invention was to provide a method for producing a multilayer To provide painting, in particular refinishing, which makes it possible to Environmentally friendly filler coating, even in high layer thicknesses and with high pigmentation easy to apply.
• the coatings obtained are said to harden quickly and completely and be easy to sand after a short drying time as well as very good interlayer adhesion, good topcoat level and satisfactory Ensure chemical, gasoline and water resistance.
• the object is achieved by a method for producing a multilayer Repair painting, in which, if necessary, with a primer and / or other coating agents precoated substrate a filler coating agent applied and then a top coat of a color and / or effect basecoat and a transparent clearcoat or a Top coat is applied from a pigmented single-layer top coat, characterized in that such a filler is used is either exclusively through radical and / or cationic Contains polymerization curable binders, these binders by means of high-energy radiation can be cured, or by radical and / or contains cationic polymerization curable binders, these binders can be cured by means of high-energy radiation and additionally chemically contains crosslinking binders.
• Multicoat paint systems obtained according to the invention do the same for a high level of properties required for painting, as was previously the case with usual proven but solvent-based paints, especially repair paints, was achieved. This applies in particular to properties such as sandability, Top coat level, water and chemical resistance. It also became surprising found that the multilayer structure according to the invention with respect Interlayer adhesion as well as quick and complete hardening even in high Layer thicknesses and with high pigmentation a usual refinish build-up is superior.
• the filler coating compositions which can be used in the process according to the invention are coating agents which are emitted by means of high-energy radiation crosslink radical and / or cationic polymerization. It can be about Act high-solids aqueous or solvent-containing systems, for example with a solids content of 50 to 95 wt .-% (with aqueous as well conventional, solvent-based systems). However, the systems can also be used as 100% coating agent that is applied without solvent and without water can be present.
• curable by means of high-energy radiation binders can Process according to the invention all conventional radiation-curable binders or their Mixtures are used that are known to the person skilled in the art and in the literature are described. It is either through radical or through cationic polymerization crosslinkable binders. With the former arise through Exposure to high-energy radiation on the photoinitiators radicals, which then trigger the crosslinking reaction. With the cationic curing systems formed by radiation from initiators Lewis acids, which in turn the Trigger crosslinking reaction.
• the free-radically curing binders can e.g. to prepolymers like Poly- or oligomers, the radical polymerizable olefinic double bonds have in the molecule, act.
• prepolymers or oligomers are (meth) acrylic functional (meth) acrylic copolymers, epoxy resin (meth) acrylates, Polyester (meth) acrylates, polyether (meth) acrylates, polyurethane (meth) acrylates ,, Amino (meth) acrylates, silicone (meth) acrylates, melamine (meth) acrylates, unsaturated Polyurethane or unsaturated polyester.
• the number average molecular weight (Mn) of this Compounds is preferably 200 to 10,000.
• Aliphatic and / or cycloaliphatic (meth) acrylates are preferred in each case used.
• (Cyclo) aliphatic polyurethane (meth) acrylates are particularly preferred, Polyester (meth) acrylates and epoxy (meth) acrylates.
• the binders can be used individually or used in a mixture.
• the prepolymers can be used in combination with reactive diluents, i.e. reactive polymerizable liquid monomers.
• the reactive thinners are in generally in amounts of 1-50% by weight, preferably 5-30% by weight, based on the total weight of prepolymer and reactive diluent used.
• the Reactive diluents can be mono-, di- or polyunsaturated. Examples for monounsaturated reactive diluents are: (meth) acrylic acid and its esters, Maleic acid and its half esters, vinyl acetate, vinyl ether, substituted Vinyl ureas, styrene, vinyl toluene.
• unsaturated reactive thinners are: di (meth) acrylates such as alkylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, vinyl (meth) acrylate, allyl (meth) acrylate, Divinylbenzene, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate.
• di (meth) acrylates such as alkylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, vinyl (meth) acrylate, allyl (meth) acrylate, Divinylbenzene, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate.
• polyunsaturated reactive thinners examples include: glycerol tri (meth) acrylate, Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate.
• the reactive diluents can be used individually or in a mixture become.
• Preferred reactive diluents are diacrylates such as e.g. Dipropylene glycol diacrylate, tripropylene glycol diacrylate and / or hexanediol diacrylate used.
• Binders known to those skilled in the art and described in the literature are used become. These can be, for example, polyfunctional epoxy oligomers which contain more than two epoxy groups in the molecule. It is about for example polyalkylene glycol diglycidyl ether, hydrogenated bisphenol A glycidyl ether, Epoxy urethane resins, glycerol triglycidyl ether, Diglycidyl hexahydrophthalate, diglycidyl ester of dimer acids, epoxidized derivatives des (methyl) cyclohexene, e.g.
• the number average of Molar mass of the polyepoxide compounds is preferably less than 10,000. It can also Reactive thinners, e.g. Cyclohexene oxide, butene oxide, butanediol diglycidyl ether or Hexanediol diglycidyl ether can be used.
• Suitable photoinitiators are, for example, those which Absorb wavelength range from 190 to 600 nm.
• photoinitiators for radical curing systems are benzoin and derivatives, acetophenone and derivatives such as e.g. 2,2-diacetoxyacetophenone, Benzophenone and derivatives, thioxanthone and derivatives, anthraquinone, 1-benzoylcyclohexanol, organophosphorus compounds, e.g. Acylphosphine oxides.
• the photoinitiators are used, for example, in amounts of 0.1-7 % By weight, preferably 0.5-5% by weight, based on the sum of radical polymerizable prepolymers, reactive thinners and photoinitiators.
• the photoinitiators can be used individually or in combination.
• other synergistic components e.g. tertiary amines, be used.
• Photoinitiators for cationic curing systems are substances that act as onium salts are known which photolytically release Lewis acids under the action of radiation. Examples include diazonium salts, sulfonium salts or iodonium salts. Prefers are triarylsulfonium salts.
• the photoinitiators for cationic curing systems can be in amounts of 0.5 to 5 wt .-%, based on the sum of cationic polymerizable prepolymers, reactive diluents and initiators, individually or as Mixtures are used.
• curable filler coatings can be various free radicals curing systems, various cationic curing systems or radical and cationic curing systems can be combined.
• Preferred free radical curing binders are epoxy (meth) acrylates, polyurethane (meth) acrylates, polyester (meth) acrylates and (meth) acrylic functional poly (meth) acrylates.
• Aromatic are particularly preferred Epoxy (meth) acrylates.
• the examples mentioned using high-energy radiation curable binders are generally available as commercial products.
• those curable by means of high-energy radiation Filler coating agents can only be hardened using high-energy radiation Contain binders, but they can also be used in addition to those with high energy Radiation-curable binders and other chemically crosslinking binders contain.
• any chemically crosslinking binder two-component binder systems based on one hydroxy functional and one isocyanate-functional component, a hydroxy-functional and one Anhydride component, a polyamine and an epoxy component or one Polyamine and an acryloyifunctional component can be used.
• Both additionally usable binders can be those on aqueous or Act solvent based.
• the proportion of chemically cross-linking Binders can, for example, up to 50 wt .-%, based on the UV-curable Binders.
• the filler coating compositions which can be used in the process according to the invention can Contain fillers and pigments. These are the usual ones in the Paint industry usable fillers and organic or inorganic coloring and / or anti-corrosion pigments. Examples of pigments are Titanium dioxide, micronized titanium dioxide, iron oxide pigments, carbon black, azo pigments, Zinc phosphate. Examples of fillers are silicon dioxide, aluminum silicate, Barium sulfate and talc. Can improve hardness and ductility UV-curable pigments and / or fillers are also advantageously used. It These are pigments and / or fillers that are used by means of UV radiation curable compounds, e.g. are coated with acrylic functional silanes and in the Radiation curing process should be included.
• the filler coating compositions which can be used in the process according to the invention can customary paint additives included.
• the additives are the usual ones additives that can be used in the paint sector. Examples of such additives are Leveling agents, e.g. based on (meth) acrylic homopolymers or Silicone oils, anti-cratering agents, anti-foaming agents, catalysts, adhesion promoters.
• the Additives are used in the usual amounts familiar to the person skilled in the art.
• the fillers which can be used in the process according to the invention can be solvent-free be formulated. Their solids content is then 100% by weight.
• the fillers can however also contain small amounts of organic solvents and / or water.
• the solvents are common paint solvents. these can originate from the production of the binders or are added separately. Examples of such solvents are monohydric or polyhydric alcohols, e.g. Propanol, Butanol, hexanol; Glycol ether or ester, e.g.
• Methyl ethyl ketone Acetone, cyclohexanone; aromatic or aliphatic hydrocarbons, e.g. Toluene, xylene or linear or branched aliphatic C6-C12 hydrocarbons.
• the filler layer is applied to one in the process according to the invention optionally precoated substrate.
• Preferred substrates are metal or Plastic substrates.
• the fillers can be applied to conventional primers or others Intermediate layers, such as those for the multi-layer coating on the Motor vehicle sector are used to be applied. You can click on an im Pre-coated or pre-treated as part of vehicle refinishing Vehicle body or parts thereof are applied, but they can also be on Old paintwork can be applied.
• the application can be based on the known Methods, preferably by spray application.
• the fillers can be based, for example, on conventional solvent- or water-based Spatulas, primers, adhesive primers or other intermediate layers, such as for the Vehicle refinishing is common, or on old paintwork such as KTL substrates, be applied.
• the substrates or layers of paint. on the the Filler layer is applied, can be cured or pre-dried his.
• primer or primer for refinishing For example, those based on peroxide-curing unsaturated are suitable Polyester, acid-curing polyvinyl butyral, physically drying binder, e.g. Polyurethanes or acrylates, as well as two-component crosslinking Binders, e.g. based on an epoxy and a polyamine component or Polyisocyanate and a hydroxy component.
• UV radiation sources are preferred with emissions in the wavelength range from 180 to 420 nm, in particular from 200 up to 400 nm.
• UV radiation sources may be doped High-pressure mercury, medium-pressure and low-pressure lamps, gas discharge tubes, such as. Xenon low pressure lamps, pulsed and unpulsed UV lasers, UV spotlights, such as. UV emitting diodes and black light tubes.
• As a radiation source then particularly preferred so-called high-energy electron flash devices (in short: UV flash lamps).
• Preferred UV flash lamps emit light with a wavelength of 200 to 900 nm with a maximum at about 300 to 500 nm.
• the UV flash lamps contain preferably a plurality of flash tubes, for example with inert gas, such as Xenon, filled quartz tubes.
• the UV flash lamps are said to be on the surface of the curing coating an illuminance of at least 10 megalux, preferred effect from 10 to 80 Megalux per lightning discharge.
• the energy per flash discharge should preferably be 1 to 10 kJoules.
• the UV flash lamps are preferred to transportable facilities that are in front of a mending Damage point can be positioned. Depending on the circumstances, one or several UV flash lamps can be used. UV flash lamps that can be used described, for example, in WO-A-9411123 and in EP-A-525 340. UV flash lamps are commercially available.
• the drying or hardening of the filler layer can be carried out by a plurality successive lightning discharges occur. 1 to 40 are preferred successive lightning discharges triggered.
• the distance of the UV flash lamp to substrate surface to be irradiated can be 5 - 50 cm, preferably 10 - 25 cm, are particularly preferably 15-20 cm.
• the shielding of the UV lamps Avoiding radiation leakage can e.g. by using a appropriately lined protective housing around the portable lamp unit or with the help of other safety measures known to the person skilled in the art.
• the total irradiation time is in the range of a few seconds, for example in the range from 3 milliseconds to 400 seconds, preferably from 4 to 160 seconds, depending on the number of selected lightning discharges.
• the flashes can be approx. triggered every 4 s.
• the UV flash lamps are ready for use at any time, i.e. they do not require a burn-in time and can do something between two times separate curing or radiation processes remain switched off, without losing time in the re-irradiation process due to the stoving phase occur.
• a particular advantage of the method according to the invention is that high layer thicknesses can be applied in one operation (without intermediate sanding) and that even with high pigmentation of the filler, for example with a pigment volume concentration (PVC) of 30 to 45% and more, coatings with layer thicknesses of, for example, 200 to 400, preferably 300 to 400 ⁇ m can be applied by the cure rapidly and completely and are easy to sand.
• the procedure can be such that the filler coating agent is applied in several, preferably two, spray passes, and after the first spray pass or after each further spray pass, if a total of more than two spray passes, there is intermediate radiation is triggered.
• a first spray pass for example, 100 to 200 ⁇ m thickness with for example 2 to 5 flashes carried out an intermediate curing
• a further layer of, for example 100 is in a second spray pass - 200 ⁇ m is applied and it is carried out with the required Number of lightning discharges complete hardening.
• filler coating compositions which can be used in the process according to the invention can Formulated or used as a sanding filler, primer filler or wet-on-wet filler become.
• a top coating from a color and / or effect basecoat and a transparent clearcoat or a top coat made of a pigmented single-layer topcoat is in method according to the invention on the filler layer a top coating from a color and / or effect basecoat and a transparent clearcoat or a top coat made of a pigmented single-layer topcoat.
• Basecoats are all in vehicle painting, especially refinishing, usual solvent-based or water-based basecoats known to those skilled in the art suitable.
• solvent-based basecoats are those based on Polyacrylate and / or polyester resins, optionally in combination with Melamine resins and cellulose esters.
• waterborne basecoats are such Based on physically drying polyurethane, polyurethane / urea, polyester, Polyester urethane and / or polyacrylate resins and their modifications, such as e.g. acrylated or silicon-modified polyurethane and / or polyester resins.
• the hardening of the basecoat can be hot or at room temperature for example, 40-80 ° C.
• the basecoat can also be wet-on-wet, if necessary after a short flash-off phase with a clear varnish and then be cured together with the clear coat.
• One embodiment of the method according to the invention is as a basecoat to use such a binder that can be hardened by means of high-energy radiation contains.
• the binders curable by means of high-energy radiation are for example, the above in the description of the filler coating compositions binder already mentioned. In this case, however, are preferred in the basecoat aliphatic polyurethane (meth) acrylates and / or aliphatic (meth) acrylic functional Poly (meth) arylates used.
• the basecoat can be applied wet-on-wet to the filler layer (wet-on-wet filler) and filler and basecoat layers exposed to radiation together in one work step. If necessary there is a short interim exposure of the filler layer. However, it can also especially with high layer thicknesses and high pigmentation of the filler, initially the filler layer is completely hardened using UV radiation (abrasive filler), possibly in several irradiation steps, and then the separate one The basecoat film is cured with UV radiation.
• UV radiation abrasive filler
• Clearcoats that can be used for the basecoat / clearcoat topcoat are all in the Vehicle painting, especially the usual repair painting and the Suitable solvent-based or water-based clearcoats known to those skilled in the art. Examples this is based on solvent-based or aqueous clear lacquers binders containing hydroxyl groups and / or amino groups and Polyisocyanate crosslinkers and based on amino groups and binder containing acryloyl groups.
• the hardening of the clear coat can Room temperature or forced at 40 - 80 ° C, for example.
• a further embodiment of the method according to the invention consists in creating a multilayer structure which is based on a radiation-curable filler, a physically drying or chemically crosslinking base coat which is not based on radiation-curable binders, and a clear coat which contains binders curable by means of high-energy radiation.
• the basecoat can be applied to the fully cured filler and after curing the basecoat or after briefly drying the basecoat, the radiation-curing clearcoat can be applied. Then UV radiation is applied.
• the clear lacquer can contain the customary radiation-curable binders, as already mentioned above in the description of the filler coating compositions.
• Aliphatic polyurethane (meth) acrylates and / or aliphatic acrylic-functional poly (meth) acrylates are preferably used. Particularly preferred in this embodiment are binders curable by means of high-energy radiation based on aromatic epoxy (meth) acrylates and binders curable by means of high-energy radiation based on aliphatic polyurethane (meth) acrylates and / or aliphatic (meth) acrylic-functional poly (meth) in the filler ) acrylates used. There is still the possibility of applying the hardened or intermediate hardened filler layer. or wet-on-wet, to apply a customary solvent- or water-based pigmented single-coat topcoat.
• multilayer coatings with great hardness, high scratch resistance and very good chemical and water resistance are obtained in a short time.
• the individual layers of paint show very good interlayer adhesion and resistance to dissolving of the paint layers below or above. Even very thick filler layers can be applied without bubbles in one spray cycle and dry quickly. Highly pigmented fillers can also be applied in high layer thicknesses and show rapid and complete hardening.
• the filler coatings are easy to sand after a short drying time. They show a very good topcoat level.
• the coatings otherwise correspond to the requirements for a paint structure, for example a refinish structure, in the field of vehicle painting, with the drying or curing of the coatings being able to be carried out in a very short time in comparison with the paint structures which have been dried or hardened in the customary manner.
• the method according to the invention can advantageously be used in the Vehicle refinishing, in particular for refinishing Vehicle parts, smaller damaged areas and for spot repair.
• the invention is illustrated by the following example.
• the filler produced above is applied to KTL-coated sheets.
• a filler layer in a resulting dry film layer thickness of about 300 ⁇ m is applied and after a brief flash-off at room temperature, the filler layer to irradiation by a UV flash lamp is exposed (3500 Ws). It is irradiated with 30 flashes (about 120 s).
• the filler is then sanded and a solvent-based, customary pigmented two-pack topcoat based on acrylate / polyisocyanate is overpainted.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)
• Production Of Multi-Layered Print Wiring Board (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (5)

Publications (2)

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• 1998
  • 1998-11-05 PT PT98955544T patent/PT1032474E/pt unknown
  • 1998-11-05 AT AT98955544T patent/ATE206960T1/de not_active IP Right Cessation
  • 1998-11-05 US US09/555,179 patent/US6531188B1/en not_active Expired - Fee Related
  • 1998-11-05 CA CA002310716A patent/CA2310716C/en not_active Expired - Fee Related
  • 1998-11-05 DE DE59801811T patent/DE59801811D1/de not_active Revoked
  • 1998-11-05 WO PCT/EP1998/007082 patent/WO1999026733A1/de not_active Application Discontinuation
  • 1998-11-05 DK DK98955544T patent/DK1032474T3/da active
  • 1998-11-05 EP EP98955544A patent/EP1032474B1/de not_active Revoked
  • 1998-11-05 JP JP2000521926A patent/JP4439726B2/ja not_active Expired - Fee Related
  • 1998-11-05 ES ES98955544T patent/ES2167953T3/es not_active Expired - Lifetime

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