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
  • B05D3/02—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
  • B05D3/0254—After-treatment
  • B05D3/0263—After-treatment with IR heaters
• • 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
  • 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
  • B05D3/068—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 ionising radiations (gamma, X, electrons)

Definitions

• the present invention relates to a film with at least one carrier layer and at least one lacquer layer.
• PVdF polyvinylidene fluoride
• Such films are commercially available, for example, from 3M / REXAM as "In-Mold Surfacin Film”.
• WO94 / 09983 and EP 361823 / AVERY DENNISO Corp. describe multilayer films whose clear layers consist of PVdF / polyacrylate mixtures and their pigmented color layers on the basis of PVdF or polyvinylchloride via a connecting layer or directly on it. These composites are applied to the molded part after an optional carrier layer has been removed via an adhesive layer.
• the disadvantage of these films is the high halogen content of approximately 60% by weight.
• the PVdF-based layers are preferably applied from an organic solution due to the lack of sufficient extrudability, which forces a given coating sequence of 1st clear layer, 2nd base layer, to avoid signs of dissolution in the first one applied, lower effect-giving layer and thus to avoid changes in color and effect.
• clear layers of thermoplastic polymethyl methacrylate (PMMA) which are preferably obtained by coextrusion with the carrier layer and / or base layer (A. Grefenstein in Kunststoffe 87 (1997), 1332-1343).
• PMMA thermoplastic polymethyl methacrylate
• EP 251 546 describes a method for coating automotive parts with a coated film.
• the film contains a previously thermally hardened, colored lacquer.
• this process is implemented with radiation-curable lacquers in order not to deform the thermoplastic carrier films by high temperatures.
• the technical problem consists of the film properties in the initial state (on the roll - non-flowing, non-sticky, non-blocking) with the necessary thermoformability of the film during processing (elongations with more than 100%) as well as the desired usage properties of the film article (especially the mechanical one Strength and chemical resistance).
• Approaches to solving the problem are described in the patent literature, in which films are produced and processed, which usually have latent hardenability in one layer, and are cured after application of the film.
• WO96 / 10059 describes two-layer, latently thermosetting films which flow in the melt and which are used for sealing metallic joints in automobile construction. When heated, the lower layer expands, the upper layer dissolves and encloses the lower layer after curing.
• the document DE 196 33 959 describes a method for radiation-induced hardening of a protective layer which was previously back-injected with a thermoplastic plastic as the outer layer of a preformed, multi-layer decorative film in the injection mold.
• the resin composition of the protective layer in the uncured state consists of an acrylic copolymer main chain with a glass transition temperature of 40 to 120 ° C and an average molecular weight (Mw) of preferably 45,000 to 80,000 as well as at least one (meth) acrylic functional side chain, which with an at least trifunctional crosslinker with ( Meth) acryloyl groups and a photoinitiator is provided.
• the films obtained after the irradiation of the applied decorative film according to the invention are inadequate in terms of their use properties for the high demands placed on exterior parts of automobiles.
• due to the high molecular weights of the main polymer application can only take place from organic solution.
• the high expectations existing in automotive engineering cannot be met with the single-layer solutions proposed in the publication.
• the uncured or partially hardened film is to form a closed layer, the glass transition temperature of which, in order to simultaneously ensure the blocking resistance (non-stickiness) and the deep-drawing ability (deformability), should be in a certain, very low temperature range.
• the solution thus represents a classic compromise in order to meet opposing physical requirements (freedom from tack and elasticity). The degrees of freedom for selecting suitable materials are therefore very low.
• thermoplastic polymers that can be stored as block-resistant and non-flowing windable raw materials that are thermoformed during processing and during or after application the workpiece - either vacuum-assisted lamination or by injection molding in a mold with thermoplastic materials - can be networked into smooth films and their visual appearance (color and range of effects of the known vehicle paints) and their performance characteristics meet the current requirements of the automotive industry for paint systems. It is therefore the object of the present invention to provide a film composite comprising a carrier layer and at least one lacquer layer applied thereon, which no longer has the problems indicated.
• This object is achieved in that there is at least one lacquer layer based on a radiation-curable powder coating or a radiation-curable powder coating dispersion.
• the layer based on the powder coating or the powder coating dispersion can be applied directly to the carrier layer.
• a layer based on a liquid lacquer is preferably applied, onto which the powder lacquer or the powder lacquer dispersion is coated.
• a film composite is obtained with a carrier layer, possibly a filler layer, possibly a liquid lacquer layer, a layer based on a radiation-curable powder lacquer or a radiation-curable powder lacquer dispersion and, if appropriate, a transparent plastic film.
• UV powder coating binders known from coating chemistry are suitable as the material for the layer based on a powder coating. The selection depends on the application-specific requirements, e.g. B. the weather and UV resistance, intrinsic color etc. Essential to the invention are the requirements for the melting behavior of the radiation-curable particles and for the ability to chemical, largely emission-free crosslinking in the melt. Powder coatings and aqueous suspensions of UV-curable polymer powders are preferably produced and processed by known processes.
• Powder coatings according to the invention which are curable by means of ultraviolet radiation, infrared radiation or electron beams are preferred. UV radiation is particularly preferred.
• the binders known from the prior art are suitable as UV-curable powder coatings. These include e.g. B .:
• High temperature polymerization can be produced (EP 650 985).
• Double bond-free polyacrylates are transferred via H to photochemically excited, copolymeric photoinitiators of the Norrish type
• the powder coating can contain one or more of the substances mentioned. It can be produced by the methods mentioned there without the selection of powder coatings according to the invention being restricted to substances of these documents.
• the material particles of the powder coating materials used according to the invention preferably have a melting point of 50 to 150 ° C., preferably 70 to 120 ° C.
• the powder coatings can contain the known UV initiators and coinitiators (Norrish I and Norrish II types).
• the photoinitiators required for UV crosslinking are generally contained in the powder coatings and are generally selected from the substances known from the prior art.
• the polymers can also be self-crosslinking under UV light without external initiators; Examples of such UV-curable polymers are e.g. B. mentioned in US 5,558,911 or DE 196 00 147 A1 or DE 197 01 124.
• polymers according to DE 44 13 436 are UV-curable.
• the powder coatings can consist of uniform binders or blends of different binders, although not all of the components need to be UV-crosslinkable. It can also be advantageous to use UV-curable binders in combination with thermally curable binders, which leads to the formation of interpenetrating networks with particularly favorable film properties.
• the powder coating materials used according to the invention can accordingly contain crosslinking agents, so that the photochemical curing can also be supplemented by thermal crosslinking.
• Suitable crosslinkers are carboxylic acids, in particular saturated, straight-chain, aliphatic dicarboxylic acids with 3 to 20 carbon atoms in the molecule. Dodecane-1,12-dicarboxylic acid is very particularly preferably used. To modify the properties of the finished powder clearcoats, other crosslinkers containing carboxyl groups can also be used. Examples of these are saturated branched or unsaturated straight-chain di- and polycarboxylic acids and polymers with carboxyl groups.
• Powder clearcoats which contain an epoxy-functional crosslinker and an acid-functional binder are also suitable.
• tris (alkoxycarbonylamino) triazines according to US Pat. No. 4,939,213, US Pat. No. 5,084,541 and EP 0 624577. These are tris (alkoxycarbonylamino) triazines of the formula This is are tris (alkoxycarbonylamino) triazines of the formula
• R methyl, butyl, ethylhexyl groups. Derivatives of the compounds mentioned can also be used.
• the methyl, butyl mixed esters are preferred. Compared to pure methyl esters, these have the advantage of better solubility in polymer melts and mixed butyl-ethylhexyl esters.
• the pure butyl esters are also preferred according to the invention.
• the tris (alkoxycarbonylamino) triazines and their derivatives can also be used according to the invention in a mixture with conventional crosslinking agents (component C). Blocked polyisocyanates other than tris (alkoxycarbonylamino) triazines are particularly suitable here.
• Aminoplast resins are also e.g. Melamine resins, can be used. Resins of this type are well known to the person skilled in the art and are offered as sales products by many companies. Aminoplast resins are condensation products made from aldehydes, in particular formaldehyde and, for example, urea, melamine, guanamine and benzoguanamine. The amino resins contain alcohol groups, preferably methylol groups, which are generally partially or completely etherified with alcohols. Otherwise, all other suitable crosslinking agents known in the prior art can also be used. When making the selection, however, care must be taken to ensure that no significant condensation products are formed during the subsequent thermal steps if these cannot escape (e.g. in the injection mold or under a protective film).
• Suitable acid-functional binders are, for example, acidic polyacrylate resins which can be prepared by copolymerizing at least one ethylenically unsaturated monomer which contains at least one acid group in the molecule with at least one further ethylenically unsaturated monomer which does not contain any acid group in the molecule.
• the epoxy group-containing binder or the carboxyl group-containing crosslinker and the carboxyl or binder are usually described in such an amount that 0.5 to 1.5, preferably 0.75 to 1.25 equivalents of carboxyl groups are present per equivalent of epoxy groups.
• the amount of carboxyl groups present can be determined by titration with an alcoholic KOH solution.
• the binder can contain vinyl aromatic compounds, in particular styrene.
• the content is preferably not more than 35% by weight. 10 to 25% by weight are preferred.
• the solid powder coatings can optionally contain one or more suitable catalysts for curing.
• suitable catalysts are phosphonium salts of organic or inorganic acids, quaternary ammonium compounds, amines, imidazole and imidazole derivatives.
• the catalysts are generally used in proportions of 0.001% by weight to about 2% by weight, based on the total weight of the epoxy resin and the crosslinking agent.
• Suitable imidazole catalysts are, for example, 2-styrylimidazole, 1-benzyl-2-methylimidazole, 2-methylimidazole and 2-butylimidazole. This as well further imidazole catalysts are described, for example, in Belgian Patent No. 756,693.
• the solid powder coatings may also contain auxiliaries and additives typical of radiation-curable coatings. Examples of these are leveling agents, antioxidants, UV stabilizers, UV absorbers,
• Free radical scavengers, trickle aids and degassing agents such as benzoin.
• the powder lacquers used according to the invention are preferably used as clear lacquer and form the surface of the lacquer after transfer to the substrates to be lacquered.
• they can also contain colored pigmented binders;
• the choice of pigments and photoinitiators must be coordinated with regard to the transparency of the pigments, absorption of the photoinitiators and spectrum of the steel sources, these relationships are known to the coating specialist.
• the solid UV powder coatings are produced by known methods.
• Powder coatings are made by grinding and, if necessary, by classifying and
• the average core size of the powder coating contained is between 200 and 1 ⁇ m, preferably 3 and 50 ⁇ m, in particular less than 20 ⁇ m. 3 to 10 ⁇ m are most preferred.
• the UV powder coatings can also be in the form of an aqueous dispersion. This preferably contains a component A in the form of the solid UV powder coating and an aqueous component B. Particular preference is given to using aqueous powder coating dispersions comprising a solid, powdery component A and an aqueous component B, where
• Component A is a powder clearcoat containing the radiation-curable binders described above, if appropriate crosslinking agents and, if appropriate, catalysts, auxiliaries, additives typical for powder coatings, such as degassing agents, leveling agents, UV absorbers, radical scavengers, antioxidants.
• component A is dispersed in an aqueous component B.
• the continuous phase is preferably water. Possibly.
• Component B contains further constituents by means of which the powder coating materials according to the invention are dispersed and the dispersion is stabilized.
• the required application properties can be produced by additional auxiliaries. Accordingly, catalysts B, auxiliaries, defoamers, photoinitiators, dispersants, wetting agents, preferably carboxy-functional dispersants, antioxidants, UV absorbers, radical scavengers, solvents, leveling agents, dioxides and water retention agents may optionally be present in component B.
• Component B may also contain ionic and / or nonionic monomeric and / or polymeric surfactants and protective colloids.
• the selection is made taking into account the coating requirements for the hardened films.
• the use of polymeric substances which are chemically similar to component A and which can cover with the binders contained in component A during UV curing has proven to be favorable. (Substances of this type are e.g. compounds based on Polyacrylates).
• Double bond-free binders according to e.g. B. DE 44 134 36 and / or DE 196 00 147 which were polymerized with portions of (meth) acrylic acid and which were then completely or partially neutralized with nitrogen bases.
• the use of binder-like dispersants which have basic groups and have been (partially) neutralized with acids is also preferred according to the invention.
• An advantage of the present invention is that both cationic and anionic stabilizations can be chosen freely and z. B. to choose the least expensive or chemically easier to implement principle without having to take into account the chemistry of the crosslinking reaction. So z. B. the binders according to DE 44 134 36 and DE 196 00 147 inert to most chemical reactions and are crosslinked only by high-energy radiation.
• Protective polyurethane colloids which are composed of isocyanates, polyols, hydroxycarboxylic acids and hydroxy (meth) acrylates and / or are suitable for the dispersion based on polyurethanes according to the invention
• the binders can be pigmented or unpigmented or can be provided with or without dyes. However, unpigmented binders are preferred for producing powder clearcoats.
• the aqueous component B of the powder coating dispersion contains at least one nonionic thickener a).
• Non-ionic associative thickeners a) are preferably used. This applies in particular if pH values of 4-7 are to be maintained. Structural features of such associative thickeners a) are:
• aa a hydrophilic scaffold which ensures sufficient water solubility and ab) hydrophobic groups which are capable of an associative interaction in the aqueous medium.
• Long-chain alkyl residues such as e.g. Dodecyl, hexadecyl or octadecyl residues, or alkaryl residues, such as e.g. Octylphenyl or nonylphenyl radicals used.
• Polyacrylates, cellulose ethers or particularly preferably polyurethanes which contain the hydrophobic groups as polymer building blocks are preferably used as the hydrophilic frameworks.
• Polyurethanes which contain polyether chains as building blocks, preferably made of polyethylene oxide, are very particularly preferred as the hydrophilic frameworks.
• the di- and / or polyisocyanates preferably aliphatic diisocyanates, particularly preferably optionally substituted 1, 6-hexamethylene diisocyanate, are used to link the hydroxyl-terminated polyether units to one another and to link the polyether units with the hydrophobic end group units, for example may be monofunctional alcohols and / or amines with the long-chain alkyl radicals or aralkyl radicals already mentioned.
• the dispersing agents which can preferably be used in component B include u. a. Polyurethanes. These can preferably consist of
• the organic component of the polyurethane composition comprises a polyester polyol, a low molecular weight diol and / or triol or mixtures thereof. If necessary. a monomer containing trifunctional hydroxyl groups can be used.
• the polyurethane comprises
• a non-ionic stabilizer which is produced by reaction i. a monofunctional polyether with a component containing polyisocyanate to produce an isocyanate intermediate and ii. a component with at least one active amine and at least two active hydroxyl groups and 3. at least one component containing polyisocyanate.
• the organic component preferably comprises polyether polyester polyol, a low molecular weight diol and / or triol or mixtures thereof.
• the polyester component can be prepared by reacting at least one dicarboxylic acid and at least one alcohol component, the alcohol containing at least two hydroxyl groups.
• the carboxylic acid component contains two or more carboxyl groups.
• the polyester resin can also contain one or more low molecular weight diols or triols. In principle, any polyol can be used.
• polyester resins or mixtures of the polyester resins used preferably contain terminal hydroxyl groups. This is done by adding an excess of polyols.
• Both monocarboxylic acids and monoalcohols can be used to synthesize the polyesters.
• the monocarboxylic acids and / or monoalcohols are preferably present in the polyester resin in a very small amount by weight.
• the polyester diol components preferably used comprise between 20 and 80% by weight of the polyurethane resin.
• the amounts are preferably between 50 and 70% by weight. 55 to 65% by weight are very particularly preferred.
• Polyester polyols with a molecular weight between 500 and 5000 are used to produce the polyurethane. Molecular weights between 1000 and 3500 are preferred.
• the polyurethane resins can contain further organic components with at least two reactive hydrogen atoms. These are preferably diols and triols, thiols and / or amines or mixtures of these substances.
• the components that are used to synthesize the polyester component can also be used as separate components here. This means that di- or trial alcohols, such as e.g. Neopentyl glycol or 1, 6-hexanediol into consideration.
• the molecular weight of the diols and / or triols used in the polyurethane resin is between 0 and 20% by weight. 1 to 6% by weight are preferred.
• the polyurethane resin also contains polyisocyanates, especially diisocyanates.
• the isocyanates are between 5 and 40% by weight based on the polyurethane mass. 10 to 30% by weight and very particularly 10 to 20% by weight are particularly preferred.
• a monofunctional polyether is used to produce the polyurethane.
• a nonionic stabilizer is produced, in which a monofunctional polyether is preferably reacted with a diisocyanate. The reaction product formed is then reacted with a component which contains at least one active amine group and at least two active hydroxyl groups.
• the polyurethane comprises a reaction product from:
• a polyester polyol which in turn is a reaction product from a Carboxylic acid with at least two carboxyl groups and one component with at least two hydroxyl groups, 2. at least one low molecular weight component with at least two hydroxyl groups, 3. at least one polyisocyanate-containing component,
• a non-ionic stabilizer prepared by reacting a monofunctional ether with a polyisocyanate and then reacting the reaction product obtained with a component which contains at least one active amine and at least two active hydroxyl groups.
• the polyurethane comprises a reaction product
• the polyesters are synthesized with the carboxylic acid component described above and an excess of polyols.
• the excess of polyols is chosen so that terminal hydroxyl groups are preferably formed.
• the polyols preferably have a hydroxyl functionality of at least two.
• the polyester resin preferably consists of one or more polyols, preferably a diol.
• Preferred diols are alkylene glycols, such as ethylene glycol, propylene glycol, butylene glycol and neopentyl glycol, 1,6-hexanediol or other glycols, such as bisphenol-A, cyclohexanedimethanol, caprolactone diol, hydroxyalkylated bisphenol and similar compounds.
• the low molecular weight diols preferably used according to the invention are known from the prior art. These include aliphatic diols, preferably alkylene polyols having 2 to 18 carbon atoms. Examples include 1,4-butanediol, cycloaliphatic diols such as 1,2-cyclohexanediol and cyclohexanedimethanol.
• suitable organic polyisocyanates are preferably those which comprise at least two isocyanate groups. More specifically, the isocyanates are preferred, for example p-phenylene, biphenyl, 4,4 '-Diisocyanate, toluene diisocyanates, 3,3' -dimethyl-4,4 Biphenylendiisocyanate, 1, 4-Tetramethylendiisocyanate, 1, 6-
• diisocyanates In addition to the diisocyanates mentioned, other multifunctional isocyanates are also used. Examples are 1,2,4-benzene diisocyanates and polymethylene polyphenyl isocyanates.
• aliphatic diisocyanates e.g. 1, 6-hexamethylene diisocyanate, 1, 4-butylene diisocyanate, methylene bis (4-cyclohexyl isocyanate), isophorone diisocyanate and 2,4-toluene diisocyanate.
• Longer chain polyurethane resins can be obtained by chain extension with components containing diol and / or triol groups.
• Chain extenders with at least two active hydrogen groups for example diols, thiols, diamines or mixtures of these substances, for example alkanolamines, aminoalkyl mercaptans, hydroxyalkyl mercaptans and similar compounds, are particularly preferred.
• diols used as chain extenders are 1,6-hexanediol, cyclohexanedimethylol and 1,4-butanediol.
• a particularly preferred diol is neopentyl glycol.
• the polyethers that can be used are preferably mono- or difunctional polyethers.
• the monofunctional ones include, for example, those produced by polymerizing ethylene oxides, propylene oxides or mixtures thereof.
• the described polyurethane product and also the other thickeners and dispersants contained in B can be used with conventional ones
• Crosslinkers are mixed. These preferably include aminoplast resins, e.g. Melamine resins. Condensation products of other amines and amides can also be used, e.g. Aldehyde condensates of triazines,
• Diazines, triazoles, guanidines, guanamines or alkyl- and aryl-substituted derivatives of such components are examples of such components.
• Triaminopyrimidines 2-mercapto-4,6-diaminopyrimidines, 2,4,6-
• Triethyltriamino-1, 3,5-triazines and similar substances Triethyltriamino-1, 3,5-triazines and similar substances.
• Formaldehydes are preferred as aldehyde. Acetaldehydes, crotonaldehydes, acrolein, benzaldehydes, furfural can also be used.
• the amine-aldehyde condensation products can contain methylol or similar alcohol groups.
• alcohols which can be used are methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, benzyl alcohol and aromatic alcohols, cyclic alcohols such as cyclohexanol, monoethers or glycols and substituted alcohols, for example 3-chloropropanol.
• blocked polyisocyanates can also be used as crosslinking agents.
• organic polyisocyanates such as trimethylene, tetramethylene, hexamethylene, 1,2-propylene, 1,2-butylene and 2,3-butylene diisocyanates.
• cycloalkene components such as 1,3-cyclopentane, 1,4-cyclohexane and 1,2-cyclohexane diisocyanates.
• Aromatic components such as phenylene, p-phenylene, 4,4'-diphenyl, 1,5-naphthalene and 1,4-naphthalene diisocyanates can also be used.
• aliphatic-aromatic components such as 4,4 '-Diphenylenmethan, 2,4- or 2,6-tolylene or mixtures thereof, 4,4' -Toluidin and 1, 4 xylylene into consideration.
• nuclear-substituted aromatic moieties such as 4,4 '- diphenyl ether diisocyanates and chlorodiphenylene.
• Triisocyanates are triphenylmethane-4,4 ', 4 "triisocyanate, 1, 3,5-Triisocyanatbenzene and 2,4,6-Triisocyanattoiuol A tetraisocyanate are finally 4.4.' Diphenyl-dimethylmethane, 2,2 '-, 5,5 ' - tetraisocyanates.
• Aliphatic, cycloaliphatic aromatic alkyl mono alcohols can be used as blocking agents. These include, for example, methyl, ethyl, chloroethyl, propyl, butyl, cyclohexyl, heptyl, octyl, nonyl 3,3,5-trimethylhexanol, decyl and lauryl alcohols.
• phenolic components e.g. Phenols or substituted phenols can be used. Examples include cresol, xylenol, nitrophesol, chlorophenol, ethylphenol, 1-butylphenol and 2,5-di-t-butyl-4-hydroxytoluene.
• Suitable blocking agents are tertiary hydroxylamines, for example diethylethanolamine and oximes, such as methyl ethyl ketone oxime, acetone oxime and cyclohexanone oxime.
• diethylethanolamine and oximes such as methyl ethyl ketone oxime, acetone oxime and cyclohexanone oxime.
• oximes such as methyl ethyl ketone oxime, acetone oxime and cyclohexanone oxime.
• dispersants and thickeners which have groups via which they can be photochemically crosslinked, for example polyurethane thickeners or dispersants which are obtained with the use of unsaturated compounds such as hydroxy- or amino-functional (meth) acrylate, or ionically functionalized UV-curable binders according to DE 4413436 / DE 19600147.
• the polyurethane obtained and a crosslinking agent suitable for crosslinking it can be present in the powder slurry as a compressor or dispersant in a proportion of 2 to 20% by weight, preferably 5 to 15% by weight.
• the aqueous powder clearcoat dispersion can be prepared from components A and B by wet grinding or by stirring in dry-ground powder coating. Wet grinding is particularly preferred.
• component A After component A has been dispersed in component B, grinding is carried out if necessary, the pH is adjusted to 4.0 to 7.0, preferably 5.5 to 6.5 and filtered.
• the average grain size is between 1 and 200 ⁇ m, preferably less than 20 ⁇ m, particularly preferably 3 to 10 ⁇ m.
• Powder clearcoat dispersion is between 15 and 50%.
• the dispersion can before or after wet grinding or
• defoamers, dispersing aids, wetting agents and / or thickeners are preferably first dispersed in water. Then small portions of the powder clear lacquer are stirred in. Then defoamers, dispersing aids, thickeners and wetting agents are dispersed again. Finally, powder clear lacquers are stirred in again in small portions.
• the pH is preferably adjusted using ammonia or amines.
• the pH value can initially rise here, resulting in a strongly basic dispersion. However, the pH drops back to the above values within several hours or days.
• Another variant for the preparation of the powder coating dispersion according to the invention consists in that a liquid melt of the binders and injuries and optionally the additives c) of component A is mixed, added to an emulsifying device, preferably with the addition of water and stabilizers, the emulsion obtained is cooled and be filtered.
• All currently existing coating systems are suitable as material for the layer based on a liquid lacquer, which may be located between the film and the powder coating layer.
• any basecoat suitable for the conventional painting of automobile bodies can be used.
• Such varnishes are well known to the person skilled in the art. They essentially contain a polymeric binder, possibly a crosslinking agent and a pigment or a mixture of pigments.
• the basecoat material which can be used according to the invention can contain, for example, a polyester resin, a polyurethane resin or a polyacrylate resin or a mixture of such binders.
• the liquid paint can also have rheological agents and other paint auxiliaries.
• pigments of any kind for example color pigments such as azo pigments, phthalocyanine pigments, carbonyl pigments, dioxazine pigments, titanium dioxide, carbon black, iron oxides and chromium or cobalt oxides, or effect pigments such as metal plate pigments, in particular aluminum plate pigments or liquid crystal polymers and pearlescent polymers, can be incorporated and pearlescent polymers.
• liquid lacquers that can be used may also contain conventional auxiliaries, additives, suitable light stabilizers (e.g. HALS compounds, benzotriazoles, oxalanilide, etc.), slip additives, polymerization inhibitors, matting agents, defoamers, leveling agents and film-forming auxiliaries, e.g. Cellulose derivatives, or other additives commonly used in basecoats.
• suitable light stabilizers e.g. HALS compounds, benzotriazoles, oxalanilide, etc.
• slip additives e.g. HALS compounds, benzotriazoles, oxalanilide, etc.
• polymerization inhibitors e.g. HALS compounds, benzotriazoles, oxalanilide, etc.
• matting agents e.g. Cellulose derivatives
• defoamers e.g. Cellulose derivatives
• film-forming auxiliaries e.g. Cellulose derivatives, or other additives commonly used
• the liquid lacquer can also contain adhesion-promoting agents so that the connection between the films and the powder lacquer is improved.
• adhesion-promoting agents such as, for example in accordance with EP 0 755 422, and anphiphilic block copolymers are particularly suitable for this.
• a prerequisite here is good flexibility of the hardened lacquer, without the resistance to stone chips and corrosion being lost.
• Such varnishes are well known to the person skilled in the art.
• the crosslinking agent may contain an aminoplast resin, a polyisocyanate resin, a crosslinking agent containing carboxyl groups or a mixture of such crosslinking agents.
• Tris (alkoxycarbonylamino) triazines are also suitable. Derivatives of these can also be used. Tris (alkoxycarbonylamino) triazines, as described in US Pat. No. 5,084,541, can preferably be used.
• the dry film layer thickness of the applied liquid lacquer layer should be between 15 and 200 ⁇ m, preferably between 50 and 100 ⁇ m.
• the dry film layer thickness of the applied layer based on powder coating or powder coating dispersions should be between 30 and 200 ⁇ m, preferably between 50 and 100 ⁇ m.
• suitable filler compositions can preferably be used for painting car bodies.
• this can be controlled via the degree of crosslinking.
• the filler layer obtained in this way has three main tasks: on the one hand to compensate for the unevenness and on the other hand to improve the stone chip resistance of the overall paint finish.
• the filler also serves to promote adhesion between the plastic film and the paint structure.
• the filler can contain the adhesion-promoting agents mentioned in connection with the liquid paint.
• the filler compositions can essentially consist of a binder, a crosslinking agent, pigments and fillers and, if appropriate, further additives, such as crosslinking catalysts and flow control agents.
• the filler compositions which can be used can contain, for example, epoxy resins, polyester resins, polyurethane resins, polyacrylate resins and alkyd resins or combinations of such resins as binders.
• the filler compositions which can be used can contain aminoplast resins, such as melamine-formaldehyde resins, amines, polyisocyanates and compounds containing carboxyl groups, as crosslinking agents. Titanium dioxide, phthalocyanines, iron oxides and carbon black are mentioned as examples of pigments which can be contained in the filler compositions which can be used.
• the filler compositions can contain, for example, lime or barium sulfate as fillers.
• Suitable materials for the carrier layer to be coated are all thermoplastically deformable plastics such as polyolefins, polyester, polyamide, polyurethane, polyacrylate, in particular copolymers of acrylonitrile, styrene, acrylic esters (e.g. types of LURAN and LURAN S.). Blends of different thermoplastics are of course also suitable, e.g. B. from polycarbonate and polybutylene terephthalate. Mixtures of the substances mentioned are also suitable.
• the film thickness can be between 10 and 1000 ⁇ m, preferably 10 to 500 ⁇ m, most preferably 20 to 250 ⁇ m, and depends only on practical aspects for processing.
• self-supporting lacquer films can also serve as a carrier layer.
• Such layers of paint are e.g. B. described in DE 195 35 934.
• a transparent plastic film can be applied to the layer based on the UV powder coatings or UV powder coating dispersions described.
• the materials that are also suitable for the carrier film can be used here.
• Polyolefin films are currently preferred for cost reasons.
• the films coated according to the invention can be rolled up.
• the products can therefore be offered and delivered in the form of rolls.
• the lacquers used according to the invention must have sufficient flexibility for rolling up.
• the moisture in particular water, can first be removed by applying heat. That is, UV powder coating dispersions applied to the substrates can initially be largely predried before UV curing. This can happen with Room temperature or accelerated at elevated temperature. As a rule, the elevated temperature can be 40 to 70 ° C., preferably 50 to 65 ° C.
• Predrying can be carried out for 2 to 12 minutes, preferably less than 2 minutes.
• the powder layer is then preferably melted by means of IR radiation or other heat supply.
• the powder parts are sintered together at least to the extent that they are glued at the points of contact so that the coated film can be wound up without problems.
• the particles from the powder coating dispersion or the powder coatings are preferably in a dried, sintered, partially crosslinked form.
• the film can also be deformed at temperatures below the melting point of the particles.
• the particles glued to one another at points can be separated at their contact points. If there are strong local deformations, macroscopic, visually perceptible cracks can then occur in the layer. Since it is still a largely uncrosslinked material in this state, the cracks can then be closed by the melting material when melting before UV crosslinking.
• this is preferably done in the injection mold by the warm one Plastic mass.
• flow takes place by exposure to infrared light and / or by inductive heating and / or by the action of hot media (e.g. circulating air).
• the foils can also be applied to all molded part blanks, preferably metal sheets, which are used to manufacture vehicle bodies, add-on parts for vehicle bodies, household appliances, e.g. Refrigerators, washing machines, dishwashers are suitable to be applied.
• the foils are mainly applied to pretreated metal sheets. These can be pretreated, for example, by phosphating and / or chromating.
• coated films made as described above can be applied to the surface of a blank, i.e. a not yet deformed substrate, preferably sheet metal, are laminated.
• the film can first be laminated onto the non-deformed substrate, then deformed, finally filmed and hardened.
• Adhesion to the surface to be coated can be achieved in different ways.
• One possibility is, for example, that foils which have adhesion-promoting groups such as urethane groups, acid anhydride groups or carboxyl groups or foils which have been provided with adhesion-promoting groups by coextrusion with a polymer having adhesion-promoting groups.
• the adhesion between the film and the surface to be coated can also be achieved by using an adhesive can be achieved.
• Adhesives that are solid at room temperature and liquid at room temperature can be used.
• Heat template to reflux (approx. 80 ° C), start feed 2 and add in 3 hours, 15 minutes after start 2 start, start rest of feed 2 and add in 3.5 hours. After the end of the feed, hold at reflux for 2 hours, cool to 60 ° C. and add inflow 3 and heat to reflux again. Hold at reflux for 2 hours, cool to 60 ° C and replace the reflux condenser with a distillation head, then at Heat normal pressure up to an internal temperature of 130 ° C and distill off the solvent. 345 T of distillate are obtained. A viscous polymer melt results in the flask. It is cooled to approximately 100 ° C. and feed 4 is started. After approx. 30% of the feed has been stirred in, the heating is removed and the remaining feed is stirred in when the temperature then drops and stirring is continued until it cools to room temperature. The result is a viscous, slightly cloudy resin solution.
• the mixture is heated to 125 ° C under a gentle stream of nitrogen and then over a dropping funnel in one hour
• the temperature is gradually raised to 190 ° C. in the course of 6 hours, during which the water of condensation formed is distilled off.
• a resin with an acid number of 17 is obtained which solidifies on cooling and gives powder which does not cake after grinding.
• Fluid mixer mixed, extruded on a BUSS PLK 46 extruder, ground on a Hosohawa ACM 2 mill and sieved through a 125 ⁇ m sieve.
• T lrgacure 184 (photo initiator, Ciba) are intimately placed on a Henschel
• Fluid mixer mixed, extruded on a BUSS PLK 46 extruder, ground on a Hosohawa ACM 2 mill and sieved through a 125 ⁇ m sieve.
• UV powder coating dispersions UV powder slurries
• the basis was films made of acrylonitrile-styrene-acyl ester (Luran S 797, BASF AG), which were coated with a commercially available waterborne basecoat for automobiles with a roller and passed through a segmented convection oven with heated air at a temperature gradient of 40 ° C to 100 ° C and one Duration of 2 minutes was dried so that a non-tacky but largely uncrosslinked film with a layer thickness of about 50 microns resulted on the films.
• acrylonitrile-styrene-acyl ester Liuran S 797, BASF AG
• the powder coatings were sprinkled onto the base films using a sieve with a mesh size of 100 ⁇ m in such a way that final layer thicknesses of approximately 60 ⁇ m are obtained.
• the UV powder coating dispersions were knife-coated with a roller.
• the selective gluing of the UV lacquer powder and the drying of the water and subsequent selective gluing of the powder coatings resulting from the drying of the water from the UV powder lacquer dispersions was carried out by passing through a segmented convection oven with heated air at a temperature gradient of 40 ° C to 100 ° C and a duration of 3 minutes for powder applications and 7 minutes for UV powder coating dispersions;
• Pieces of film according to 5.1 were placed on a smooth glass plate, where they lay largely flat.
• the films were then irradiated with an IR lamp from a distance of 30 cm for 90 seconds.
• the surface temperature of the film reaches approx. 120 ° C and the previously whitish powder coatings melt into clear, smooth melts. Differences between coatings that had macroscopically recognizable cracks and those without these cracks were not recognizable after the melt.
• the IR lamp was pivoted to the side and the slide valve of a switched on UV mercury vapor lamp attached above the foils was opened with an emission maximum at about 365 nm for 90 seconds.
• the temperature of the toppings dropped to approx. 115 ° C.
• the result was hard, shiny, scratch-resistant coatings which showed no attack after 50 strokes with a cotton ball moistened with methyl ethyl ketone.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
• Adhesive Tapes (AREA)

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• 1998
  • 1998-08-04 DE DE1998135194 patent/DE19835194A1/de not_active Ceased
• 1999
  • 1999-07-21 BR BR9912743-1A patent/BR9912743A/pt not_active IP Right Cessation
  • 1999-07-21 WO PCT/EP1999/005181 patent/WO2000008094A1/de not_active Application Discontinuation
  • 1999-07-21 JP JP2000563722A patent/JP2003521557A/ja active Pending
  • 1999-07-21 EP EP99938304A patent/EP1121387A1/de not_active Withdrawn

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