DE102006055081A1 - Urethane epoxides for the low-temperature curing of coatings, methods of manufacture and use - Google Patents

Abstract

The present invention relates to a novel coating system based on epoxy-functional urethanes (urethane epoxides) for thermosetting compositions. Moreover, the present invention relates to the preparation and application of paint systems consisting of the urethane epoxides and a koreanctand, as well as other, known for the production of paints fillers and additives.

Description

The The present invention relates to a novel coating system the basis of epoxy-functional urethanes (urethane epoxides) for thermal curing Masses. Furthermore The present invention relates to the preparation and application paint systems consisting of the urethane epoxides and a coreactant, as well as further, for the production of paints known fillers and additives.

patent EP 0 228 935 mentions urethane epoxides in connection with the preparation of oxazolidines.

patent GB 1,072,716 describes a process of preparing urethane epoxides by the reaction of epoxy alcohols (eg, 3,4-epoxy-4-methylpentanol-2) and isocyanates (eg, 2-naphthyl isocyanate, TDI). Also mentioned is the use as a crosslinker in paints.

patent US 3,440,230 describes the preparation of epoxyurethanes by the reaction of (poly) isocyanates with epoxy alcohols, as well as their use as a self-curing bonding agent (bonding agent). Self-crosslinking is postulated by intermolecular reaction of urethane NH with another epoxide group. It is also mentioned that the compounds obtained are stable in storage at room temperature for several weeks.

patent US 4,020,034 describes weather-stable coatings obtained from the crosslinking reaction of a urethane epoxide with an aliphatic or cycloaliphatic acid or its anhydride (eg tetrahydrophthalic acid). The coatings were applied from a solvent.

patent DE 31 38 196 describes powdery coating compositions and their use. As the binder, there are mentioned both resins obtained by olefin polymerization and condensation reactions. As a hardener serve urethane epoxides, which were obtained by reaction of a (poly) isocyanate with glycidol (eg TDI) and have a melting point of 30 to 100 ° C. The patent mentions stoving conditions of from 5 to 40 minutes at 150 to 260 ° C.

patent RU 2 230 088 describes urethane epoxides prepared by reaction of polyisocyanates (eg TDI), a spacer (eg polytetrahydrofuran) and glycidol. From the present invention, this technique differs by the crosslinking by means of polyamines (eg, organosilicone diamines) and the use of an organic solvent.

patent JP 5295079 describes thermosetting coatings in which the urethane epoxide component is represented as follows. Monosubstitution of TDI with glycidol and subsequent reaction with an alcohol or thiol having a functionality ≥ 1. The liquid resins thus obtained are mixed with a diamine (eg, 1,3-bis (aminomethyl) cyclohexane) and at 80 ° C for one hour hardened.

The patents DE 103 20 431 and DE 103 20 432 describe urethane epoxide functional silanes, a process for their preparation and their use. This mentions both the thermal hardening and the hardening by blasting. In particular, they differ from the present invention in that the coatings are so-called sol-gel coatings.

In various publications, Edwards et al. the synthesis of urethane epoxides and their use as thermosetting coating material ( Edwards PA, Erickson J., Webster DC, Polymer Preprints 2003, 44 (1), 54 ; Edwards PA, Erickson J., Webster DC, Polymer Preprints 2003, 45 (1), 935 ; Edwards PA, Erickson J., Webster DC, ICT Research 2005, 2 (7), 517 ). The order of the coating material is made from solution. The curing takes place by reaction with added amines or from temperatures of 150 ° C intermolecularly with other urethane epoxides. The intramolecular ring closure is mentioned but does not seem to play a role in these systems.

The Previously known (powder) coating systems have the following Disadvantage on. To a complete curing To ensure the coatings are to harden temperatures of 150 necessary up to 200 ° C. Besides the high energy costs for the curing process This type of coating is based on thermoresistant materials limited. objects made of wood or plastic can not be coated.

In the curing of UV powder coatings can be dispensed with a strong heating of the substrate who but these have the disadvantage that complete curing takes place only on shadow-free areas. For geometrically complicated workpieces, this technology is unsuitable.

Consequently It is an object of the present invention to provide a coating composition, which can be applied universally and cured at low temperatures. Furthermore, it is an object of the present invention, a method specify with which such a coating composition prepared can be.

The The object is achieved by a coating composition having the features of the claim 1 and solved by the method having the features of claim 21. In the claims 24 to 26, uses of the coating composition are given. The respective dependent claims represent advantageous developments.

• (A) 5 bis 100 Gew.-% eines 2 oder mehr Epoxygruppen pro Molekül enthaltenden Umsetzungsproduktes aus einem Di- und/oder Polyisocyanat mit einem Di- und/oder Polyol, und/oder einem Di- und/oder Polyamin, und einem Glycidalkohol und/oder Glycidphenol, wobei das Umsetzungsprodukt einen Tg zwischen 30 und 120°C, gemessen mittels DSC, aufweist.
• (B) 0 bis 95 Gew.-% eines Koreaktanten aus der Gruppe (i) carboxylfunktioneller Polyester, wobei der Polyester einen Tg im Bereich von 30°C bis 80°C, gemessen mittels DSC, und eine Säurezahl von 20 bis 100 mgKOH/g aufweist, und/oder (ii) carboxylfunktionelle Polymere, wobei das Polymer einen Tg im Bereich von 30°C bis 80°C, gemessen mittels DSC, und eine Säurezahl von 20 bis 200 mgKOH/g aufweist, und/oder (iii) Di- und/oder Polycarbonsäuren und/oder deren Anhydride (iv) Di- und/oder Polyole.

According to the invention, a thermosetting powdery coating composition is provided, comprising

• (A) 5 to 100 wt .-% of a 2 or more epoxy groups per molecule containing reaction product of a di- and / or polyisocyanate with a di- and / or polyol, and / or a di- and / or polyamine, and a glycidyl alcohol and / or glycidophenol, wherein the reaction product has a Tg between 30 and 120 ° C, as measured by DSC.
• (B) 0 to 95% by weight of a co-reactant from the group consisting of (i) carboxyl-functional polyester, the polyester having a Tg in the range from 30 ° C to 80 ° C, measured by DSC, and an acid number from 20 to 100 mgKOH / g. and / or (ii) carboxyl-functional polymers, the polymer having a Tg in the range from 30 ° C. to 80 ° C., measured by means of DSC, and an acid number from 20 to 200 mg KOH / g, and / or (iii) Di- and / or polycarboxylic acids and / or their anhydrides (iv) di- and / or polyols.

The inventive solution exists in the use of condensates of polyisocyanates and alcohols and / or amines, as well as glycidyl alcohols. This allows powder coatings which cure in a temperature range of 90 to 150 ° C.

In With regard to the prior art, it was surprising and obvious to a person skilled in the art unpredictable that the task of the present invention underlying, using the inventive system and the method according to the invention solved can be.

Especially it was surprising that the hardener according to the invention also without external catalysts at comparatively low temperatures of 150 ° C cure quickly left.

In addition, the Hardener according to the invention easily be modified so that they thermally cured coatings and paint finishes that are weather-resistant, flexible, clear, scratch resistant and resistant to chemicals.

The The present invention thus relates to a powdery coating agent on the base a solid urethane epoxide. It will preferably be one or more Coreactants from the groups alcohols, carboxylic acids and their anhydrides, as well by addition or Condensation reactions prepared oligomers and polymers for curing used. The present invention also relates to the use the Urethanepoxid system according to the invention for the electrostatic powder coating and the vortex sintering process.

conventional thermosetting Powder coatings have processing temperatures of 150 to 200 ° C. In order to are temperature-sensitive materials such as wood or plastics not by powder coating, or difficult to access. By the present invention, the processing temperatures can be up at 100 ° C reduce.

Preferably, both aromatic and aliphatic or heterocyclic di- or polyisocyanates can be used to prepare the urethane epoxides as the isocyanate component, for example 4,4'-methylene-bis (benzyl isocyanate), 4,4'-methylene-bis (cyclohexyl isocyanate), 1 , 5-naphthylene diisocyanate, 2,4- and 2,5-toluene diisocyanate, tetramethylxylylene-1,4-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate and isocyanurated diisocyanates, such as isocyanurated isophorone diisocyanate. Preferred isocyanate components are isophorone diisocyanate and hexamethylene diisocyanate nat.

worin
R₁ für einen Alkylen- oder Arylenrest mit 1 bis 10 Kohlenstoffatomen
R₂, R₃, R₄ für Wasserstoff, eine Methyl- oder Ethylgruppe stehen, beispielsweise Glycidol.Suitable glycidyl alcohols are compounds of the formula

wherein
R _{1 is} an alkylene or arylene radical having 1 to 10 carbon atoms
R ₂ , R ₃ , R _{4 are} hydrogen, a methyl or ethyl group, for example glycidol.

to increase the molecular weight and / or the degree of branching can at be added to the synthesis of urethane epoxide other components. A diol and / or a polyol with OH functionality> 2 and / or a diamine and / or a polyamine with NH functionality> 2. As suitable alcohol components called aliphatic diols, such as ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,2-Dimethylpropanediol-1,3 (neopentyl glycol), 2,5-hexanediol, 1,6-hexanediol, 2,2- [bis- (4-hydroxycyclohexal)] - propane; 1,4-dimethylolcyclohexane, diethylene glycol, dipropylene glycol and 2,2-bis [4- (2-hydroxy)] phenylpropane, or also polyols, e.g. Neopentyl glycol, glycerol, hexanetriol, pentaerytlitol, sorbitol, trimethylolethane, Trimethylolpropane, and tris (2-hydroxy) isocyanurate, or oligomers, Polymers, and copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, Lactones and lactams. Suitable amine components are aliphatic and aromatic, such as, for example, ethylenediamine, isophoronediamine, 3,4'-methylenediphenylamine, 4,4'-methylene diphenylamine, Trimethylhexamethylenediamine, m-xylylenediamine, 1,2-diaminocyclohexane. Also suitable are diethanolamine, N-methylethanolamine and diisopropylamine.

The Urethane epoxides are preferably in an organic polar aprotic solvents, such as ethyl acetate, made and can after the reaction by vacuum distillation, spray drying or failures in a solvent other polarity from the original one Solvent freed become.

The Component which serves as a reactant may be a polycarboxylic acid Anhydride, a polyestercarboxylic acid, a polyacrylate carboxylic acid, a polyol or mixtures thereof. Suitable coreactants are aliphatic and / or cycloaliphatic carboxylic acids, e.g. 1,4-cyclohexadicarboxylic acid, tetrahydrophthalic acid, hexachlorophthalic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, adipic acid, dodecanedicarboxylic acid, succinic acid, maleic acid or dime fatty acids, and, if available, their anhydride, hydroxycarboxylic acids, such as. 12-hydroxystearic acid, and / or aromatic polybasic carboxylic acids, e.g. Terephthalic acid, isophthalic acid, phthalic acid, pyromellitic acid, trimellitic acid, 3,6-dichlorophthalic acid, tetrachlorophthalic acid, and, if available, their anhydride. In small amounts, monocarboxylic acids, such as e.g. benzoic acid, Tertiarybutylbenzoic acid, hexahydrobenzoic acid and saturated aliphatic monocarboxylic acids for use. The proportion of reactive groups of the coreactant is generally 0.1 to 3 times, preferably 0.5 to 1.5 times, the stoichiometric Amount based on the epoxide content of the urethane epoxide.

Prefers contain the powder coatings of the invention a catalyst for the accelerated reaction of the epoxide groups. Suitable catalysts are for example quaternary Ammonium and phosphonium salts, metal salts or metal compounds, such as tin (II) octoate, basic compounds such as Example imidazole, and tertiary Amines such as N-benzyldimethylamine and 1,8-diazabicyclo [5,4,0] -7-undecene. The catalyst or a catalyst mixture is preferably added in an amount such that the gel time of the mixture at 130 ° C about 70 to 400 seconds, preferably 90 to 200 seconds.

• (A) 5 bis 90 Gew.-% des Umsetzungsproduktes,
• (B) 5 bis 90 Gew.-% des Koreaktanden und
• (C) 0,1 bis 50 Gew.-% an Pigmenten und/oder Füllstoffen und/oder Additiven.

In particular, compositions are preferred containing:

• (A) 5 to 90% by weight of the reaction product,
• (B) 5 to 90% by weight of the coreactant and
• (C) 0.1 to 50 wt .-% of pigments and / or fillers and / or additives.

• (A) 30 bis 85 Gew.-% des Umsetzungsproduktes,
• (B) 10 bis 30 Gew.-% des Koreaktanden und
• (C) 3 bis 50 Gew.-% Füllstoffe, 0,1 bis 5 Gew.-% Additive und 0,01 bis 5 Gew.-% Katalysator.

Further preferred are compositions comprising:

• (A) 30 to 85% by weight of the reaction product,
• (B) 10 to 30% by weight of the coreactant and
• (C) 3 to 50% by weight of fillers, 0.1 to 5% by weight of additives and 0.01 to 5% by weight of catalyst.

The Coating composition is preferably in the form of a powdered ground Extrudates ago, wherein it is advantageous if the average particle size of the pulverulent ground Extrudates <100 microns.

According to the invention as well a process for producing a thermosetting powdery coating composition as mentioned above provided wherein the formulation ingredients at 60 to Extruded 140 ° C and subsequently chilled and granulated.

Cheap is if it's powdery milled extrudate is screened to a particle size <100 microns.

Farther it is advantageous if the formulation components of a granulation by means of high-pressure spraying process (PGSS, RESS or GAS process), by extrusion with addition of gas, the VEDOC Advanced Manufacturing Process (VAMP), the Continuos Powder Coating Spraying Process (CPCSP) or spray drying.

object The present invention likewise relates to the use of the pulverulent coating compositions according to the invention, optionally in combination with pigments, leveling agents, antistatic agents, Catalysts and other aids and the electrostatic Powder coating e.g. after the triboelectric or corona powder spraying process or the fluidized bed process or after the fluidized bed process. suitable Application methods for the powder coatings of the invention are e.g. the flame spraying, charge-free sprinkling on the coating materials, vortex sintering and preferably electrostatic Powder painting.

The applied powder coatings according to the invention are generally between 50 to 200 ° C, preferably 70 to 150 ° C, especially preferably 80 to 130 ° C, while Hardened for 5 to 60 minutes.

The powdery coating compositions of the invention are suitable e.g. for coating metal parts, such as automobile bodies, Window parts, facade cladding and the like, and for coating of non-metallic surfaces like glass, ceramics, plastics and wood. In the unpigmented state are she also as a topcoat for To use metallic paints. Furthermore, they are for the coating of household appliances, pipes as well as devices suitable for agriculture and forestry.

Besides is also the application of the coating compositions of the invention aqueous or non-aqueous solvents conceivable. As a coreactant then also aliphatic and aromatic di- and / or polyamines, such as, for example, ethylenediamine, Isophoronediamine, 3,4'-methylenediphenylamine, 4,4'-methylenediphenylamine, Trimethylhexamethylenediamine, m-xylylenediamine, 1,2-diaminocyclohexane. Also suitable are diethanolamine, N-methylethanol amine and diisopropylamine.

The Invention will be explained in more detail with reference to the following examples, without the invention, however, to the special parameters mentioned there to restrict.

Examples and Comparative Examples

Production Example 1:

In a flask equipped with a reflux condenser and a stirrer, 532.8 g (6 parts) of isophorone diisocyanate and 1.3 g of dibutyltin dilaurate were dissolved in 800 g of methyl ethyl ketone under nitrogen and cooled to 10 ° C. Subsequently, a mixture of 53.6 g (1 part) of trimethylolpropane and 108 g (3 parts) of 1,4-butanediol was added slowly with stirring. Upon completion of the addition, the reaction mixture was slowly warmed to room temperature. Subsequently, 88.8 g (3 parts) of glycidol were added to the reaction mixture. The resulting reaction mixture was stirred under nitrogen for 14 hours at room temperature and 10 hours at 60 ° C, after which the reaction was complete (detected by the disappearance of the isocyanate band in the IR spectrum of the reaction mixture). The reaction product was separated by precipitation in petroleum ether.
E number: 0.19 equ./100 g (should be: 0.15 equ./100 g) T G = 70 ° C

Production Example 2:

In a flask equipped with a reflux condenser and a stirrer, 3.13.9 g (6 parts) of isophorone diisocyanate and 1.5 g of dibutyltin dilaurate were dissolved in 1200 g of methyl ethyl ketone under nitrogen and cooled to 10 ° C. Subsequently, a mixture of 63.2 g (2 parts) of trimethylolpropane and 153.18 g (1 part) of polytetrahydrofuran (M = 650 g / mol) was metered in with stirring. Upon completion of the addition, the reaction mixture was slowly warmed to room temperature. Subsequently, 69.8 g (4 parts) of glycidol were added to the reaction mixture. The resulting reaction mixture was stirred under nitrogen for 14 hours at room temperature and 10 hours at 60 ° C, after which the reaction was complete (detected by the disappearance of the isocyanate band in the IR spectrum of the reaction mixture). The reaction product was separated by precipitation in petroleum ether.
E number: 0.13 equ./100 g (should be: 0.16 equ./100 g) T G = 50 ° C

Production Example 3

In a flask equipped with a reflux condenser and a stirrer, 30 g of trimethylolpropane were dissolved in 200 g of dioxane under nitrogen. Subsequently, initially 161.2 g of tetramethylxylylene-1,4-diisocyanate, then 0.5 g of dibutyltin dilaurate were added slowly at room temperature. After completion of the addition, the reaction mixture was stirred at 80 ° C for 4 hours. Subsequently, 74 g of glycidol were added to the reaction mixture. The resulting reaction mixture was stirred under nitrogen for 4 hours at 80 ° C and a further 14 hours at room temperature, after which the reaction was complete (detected by the disappearance of the isocyanate in the IR spectrum of the reaction mixture). The reaction product was separated by precipitation in diethyl ether.
E number: 0.24 equ./100 g (should be: 0.28 equ./100 g) T G = 65 ° C

Example 1:

509.2 g Preparation Example 1 with an epoxide number of 0.19 equ./100 g and a Tg of about 70 ° C, 178.9 g of poly-dodecanedioic anhydride, 300.0 g Kronos Titan 2160, 10.0 g Resiflow PV88 (leveling agent on Polyacrylate base) and 2.0 g of benzoin are in a Henschel mixer at 700 rpm during Dry mixed for 30 seconds and then on a Thysson co-kneader (TSK 20) at a jacket temperature of 80 ° C and one screw revolution extruded at 500 rpm. The extrudate is cooled, ground and sieved to <90 μm. The powder coatings are electrostatically (corona or tribo) both on aluminum sheets (Q-panel AL-36 5005 H 14/08 (0.8mm)), as well as on steel sheets (Q-panel R-36 (0.8 mm)) and applied at a stoving temperature of 130 ° C and a Burn-in time of 15 min in the electric oven UT6060 from Heraeus (D) cured. The layer thickness is approx. 80 μm. The film properties are shown in the table.

Example 2:

494.24 g Preparation Example 1 with an epoxide number of 0.19 equ./100 g and a Tg of about 70 ° C, 173.8 g of poly-dodecanedioic anhydride, 300.0 g of Kronos Titan 2160, 20.0 g of n-butyltriphenylphosphonium chloride, 10.0 g Resiflow PV88 (polyacrylate leveling agent), and 2.0 g benzoin in a Henschel mixer at 700 rpm for 30 dry mix and then on a Thysson co-kneader (TSK 20) at a jacket temperature of 80 ° C and one screw revolution extruded at 500 rpm. The extrudate is cooled, ground and sieved to <90 μm. The powder coatings are electrostatically (corona or tribo) both on aluminum sheets (Q-panel AL-36 5005 H 14/08 (0.8 mm)), as well on steel sheets (Q-panel R-36 (0.8 mm)) and applied at a stoving temperature of 130 ° C and a Burn-in time of 15 min in the electric oven UT6060 from Heraeus (D) cured. The layer thickness is approx. 80 μm. The film properties are shown in the table.

Example 3:

820g Preparation Example 2 with an epoxide number of 0.13 equ./100 g and a Tg of about 50 ° C, 180g poly-dodecanedioic anhydride are dry blended in a Henschel mixer at 700 U / min for 30 sec and then on a Thysson co-kneader (TSK 20) at a jacket temperature of 70 ° C and a screw revolution of 500 rev / min extruded. The extrudate is cooled, ground and <90 microns sieved. The powder coatings are electrostatically applied (Corona or Tribo) both on aluminum sheets (Q-panel AL-36 5005 H 14/08 (0.8 mm)), and on steel sheets (Q-panel R-36 (0.8 mm)) and at a Curing temperature of 130 ° C and a baking time of 15 min in the electric oven UT6060 from Heraeus (D) cured. The layer thickness is about 80 microns. The film properties are shown in the table.

Comparative Example RAL9010:

657.5 g Crylcoat 2630-2 with an acid number of 33 mgKOH / g and a Tg of ca. 60 ° C, 32.5 g of Primid XL-552, 300.0 g Kronos Titan 2160, 8.0 g Resiflow PV88 and 2.0 g benzoin dry blended in a Henschel mixer at 700 rpm for 30 sec and subsequently on a Thysson co-kneader (TSK 20) at a jacket temperature of 110 ° C and a screw revolution of 500 rpm extruded. The extrudate is cooled, ground and sieved to <90 microns.

The Powder coatings are electrostatically (corona or tribo) both on Aluminum sheets (Q-panel AL-36 5005 H 14/08 (0.8 mm)), as well applied to steel sheets (Q-panel R-36 (0.8 mm)) and at one Baking temperature of 180 ° C and a baking time of 15 min in the electric oven UT6060 the company Heraeus (D) cured. The layer thickness is approx. 80 μm. The film properties are shown in the table.

Comparative Example clear coat:

938.0 g Crylcoat 2471-4 with an acid number of 33 mgKOH / g and a Tg of ca. 58 ° C, 55.0 g of Primid QM-1260, 5.0 g Irgafo's P-EPQ and 2.0 g of benzoin are in a Henschel mixer at 700 rpm during Dry mixed for 30 seconds and then on a Thysson co-kneader (TSK 20) at a jacket temperature of 110 ° C and one screw revolution extruded from 400 rpm. The extrudate is cooled, ground and sieved to <90 μm.

• ^♦: visuelle Beurteilung von 0 bis 5
• 0: glatt, ausgespannt, kaum Orangenschale
• 5: rauh, nicht ausgespannt, wie Schmirgelpapier
• ^♢: visuelle Beurteilung von 0 bis 5
• 0: klar, transparent, keine Trübung
• 5: undurchsichtig, milchig
• ⎕: Substrat Q-Panel Al-36, chromatiertes Aluminium
• Filmdicke ~150 μm, der Film wird in 2 Arbeitschritten aufgebracht
• Aushärtbedingung 40s/180°C für die erste Schicht 15 min/180°C zum vollständigem Aushärten
• Prüfung Die Prüfungen werden 1 h nach dem Beschichten der Bleche durchgeführt. Das beschichtete Blech wird in die Testapparatur (siehe Anlage) eingespannt. Die Biegung in der Mitte des Blechs beträgt dabei 2 mm. Das so einer mechanischen Beanspruchung ausgesetzte Blech wird für 30 s in absoluten Ethanol (98 %) getaucht und visuell auf Spannungsrisse untersucht. Sind keine Risse sichtbar, wird die Biegung um 2 mm erhöht und neuerlich geprüft. Dies wird solange wiederholt, bis erste Risse auftreten. Es wird diejenige Biegung (in mm) angegeben, bei der noch keine Spannungsrissbildung sichtbar war.

The powder coatings are electrostatically applied (Corona or Tribo) both on aluminum sheets (Q-panel AL-36 5005 H 14/08 (0.8 mm)), and on steel sheets (Q-panel R-36 (0.8 mm)) and at a Curing temperature of 180 ° C and a baking time of 15 min in the electric furnace UT6060 from Heraeus (D) cured. The layer thickness is about 80 microns. The film properties are shown in the table. Comparative Example RAL9010 example 1 Example 2 Comparative Example clear coat Example 3 Impact [inch * pd] 160 <10 <10 160 <10 History ^♦ [0-5] 1 2 3 1 3 Gel time 130 ° C [s] > 400 275 130 > 400 140 ^Micro-crack resistance ^⎕ [mm] - - - 6 > 14 Transparency ^♢ [0-5] - - - 1 1 Cross-cut according to DIN EN ISO 2409 - - - 0 0

• ^♦ : visual rating from 0 to 5
• 0: smooth, relaxed, barely orange peel
• 5: rough, unrestrained, like sandpaper
• ^♢ : visual assessment from 0 to 5
• 0: clear, transparent, no haze
• 5: opaque, milky
• ⎕: Substrate Q-Panel Al-36, chromated aluminum
• Film thickness ~ 150 μm, the film is applied in 2 work steps
• Curing condition 40s / 180 ° C for the first coat 15 minutes / 180 ° C for complete cure
• Test The tests are carried out 1 h after the coating of the sheets. The coated sheet is clamped in the test apparatus (see attachment). The bend in the middle of the Sheet metal is 2 mm. The sheet thus exposed to mechanical stress is immersed in absolute ethanol (98%) for 30 seconds and visually inspected for stress cracks. If no cracks are visible, the bend is increased by 2 mm and rechecked. This is repeated until first cracks occur. The bend (in mm) at which no stress cracking was visible is given.

Claims (26)

Thermosetting powdery coating composition, containing (A) 5 to 100% by weight of a 2 or more epoxy groups per molecule containing reaction product of a di- and / or polyisocyanate with a di- and / or polyol, and / or a di- and / or polyamine, and a glycidyl alcohol and / or glycidophenol, wherein the reaction product a Tg between 30 and 120 ° C, measured by DSC. (B) 0 to 95% by weight of a coreactant from the group (I) carboxyl functional polyester, wherein the Polyester a Tg in the range of 30 ° C to 80 ° C, measured by DSC, and an acid number from 20 to 100 mgKOH / g, and / or (ii) carboxyl functional Polymers, wherein the polymer has a Tg in the range of 30 ° C to 80 ° C, measured by DSC, and an acid number from 20 to 200 mgKOH / g, and / or (iii) di- and / or polycarboxylic and or their anhydrides (iv) di- and / or polyols. powdery Coating compound according to claim 1, characterized in that the di- and / or polyisocyanate component is selected from aromatic, aliphatic and / or heterocyclic di- and / or polyisocyanates. powdery Coating compound according to claim 2, characterized in that the di- and / or polyisocyanate component is selected from 4,4'-methylenebis (benzyl isocyanates), 4,4'-methylenebis (cyclohexyl isocyanates), 1,5-naphthylene diisocyanate, 2,4- and 2,5-toluene diisocyanate, Tetramethylxylylene-1,4-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, Trimethylhexamethylene diisocyanate and isocyanurated diisocyanates as isocyanurated isophorone diisocyanate. powdery Coating compound according to claim 3, characterized in that the di- and / or polyisocyanate component isophorone diisocyanate and / or Hexamethylene diisocyanate. powdery Coating composition according to at least one of claims 1 to 4, characterized in that the di- and / or polyol component selected is of a diol and / or a polyol with an OH functionality> 2. powdery Coating compound according to claim 5, characterized in that the di- and / or polyol component is selected from ethylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethylpropanediol-1,3 (Neopentyl glycol), 2,5-hexanediol, 1,6-hexanediol, 2,2- [bis (4-hydroxycyclohexal)] - propane, 1,4-dimethylol cyclohexane, Diethylene glycol, dipropylene glycol and 2,2-bis [4- (2-hydroxy)] phenylpropane, or polyols, e.g. Glycerol, hexanetriol, pentaerytlitol, Sorbitol, trimethylolethane, trimethylolpropane, and tris (2-hydroxy) isocyanurate, or from oligomers, polymers, and copolymers of ethylene oxide, Propylene oxide, tetrahydrofuran, lactones and lactams. powdery Coating composition according to at least one of claims 1 to 6, characterized in that the di- and / or polyamine component selected is a diamine and / or a polyamine with an NH functionality> 2. powdery Coating compound according to claim 7, characterized in that the diamine and / or Polyamine component selected is from ethylenediamine, isophoronediamine, 3,4'-methylenediphenylamine, 4,4'-methylenediphenylamine, Trimethylhexamethylenediamine, m-xylylenediamine, 1,2-diaminocyclohexane, diethanolamine, N-methylethanolamine and diisopropylamine. Powdery coating composition according to at least one of claims 1 to 8, characterized in that the glycidol alcohol is selected from compounds of general formula I.

wherein R _{1 is} an alkylene or arylene radical having 1 to 10 carbon atoms R ₂ , R ₃ , R _{4 is} hydrogen, a methyl or ethyl group. powdery Coating compound according to claim 9, characterized in that the glycidyl alcohol is glycidol. powdery Coating composition according to at least one of claims 1 to 10, characterized in that the carboxyl-functional polyester selected is made of compounds that are made by a condensation reaction of aliphatic and / or cycloaliphatic and / or aromatic polycarboxylic acids and anhydrides getting produced. powdery Coating composition according to at least one of claims 1 to 11, characterized in that the carboxy-functional polymers selected are made of compounds by a polymerization reaction of ethylenically unsaturated Connections are herge. powdery Coating composition according to at least one of claims 1 to 12, characterized in that they additionally pigments and / or fillers and / or additives. powdery Coating compound according to claim 13, characterized in that the additives selected are from phosphates and / or triboadditives and / or other additives, such as. Leveling and degassing agents, and / or yellowing stabilizers and / or heat stabilizers. powdery Coating composition according to at least one of claims 1 to 14, characterized in that it additionally contains a catalyst. powdery Coating compound according to claim 15, characterized in that the catalyst is selected is from quaternary Ammonium and phosphonium salts, metal salts or metal compounds, such as tin (II) octoate, basic compounds, such as Example imidazole, and tertiary Amines, such as N-benzyldimethylamine and 1,8-diazabicyclo [5,4,0] -7-undecene. thermosetting, powdery Coating composition according to at least one of claims 1 to Containing 16 (A) 5 to 90% by weight of the reaction product, (B) 5 to 90% by weight of the coreactant and (C) 0.1 to 50% by weight on pigments and / or fillers and / or additives. powdery Coating composition according to claim 17, characterized, that she (A) 30 to 85% by weight of the reaction product, (B) 10 to 30% by weight of the coreactant and (C) 3 to 50% by weight of fillers, 0.1 to 5 wt .-% additives and 0.01 to 5 wt .-% catalyst. powdery Coating composition according to at least one of claims 1 to 18, characterized in that they are ground in the form of a pulverulent Extrudates is present. powdery Coating compound according to claim 19, characterized in that the average particle size of the pulverulent ground Extrudates <100 microns. Method for producing a thermosetting, powdery Coating composition according to at least one of claims 1 to 20, characterized in that the formulation ingredients in 60 to 140 ° C extruded and then chilled and granulated. Method according to claim 21, characterized that the powdery milled extrudate is screened to a particle size <100 microns. Process for the preparation of a powdery coating composition according to at least one of the claims 1 to 20, characterized in that the formulation ingredients granulation by means of high-pressure spraying (PGSS, RESS or GAS process), by extrusion under addition of gas, the VEDOC Advanced Manufacturing Process (VAMP), the Continuous Powder Coating Spraying Process (CPCSP) or spray drying be subjected. Use of the thermosetting powdery Coating composition according to at least one of claims 1 to 20 for the electrostatic powder coating after the triboelectric or corona powder spraying or the fluidized bed process. Use of the thermosetting powdery Coating composition according to at least one of claims 1 to 20 for the flame spraying or the charge-free spreading on to be coated Materials. Use of the thermosetting powdery Coating composition according to at least one of claims 1 to 20 for Protective layers and / or decorations.