Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
  • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
  • C08G18/6633—Compounds of group C08G18/42
  • C08G18/6659—Compounds of group C08G18/42 with compounds of group C08G18/34
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/0804—Manufacture of polymers containing ionic or ionogenic groups
  • C08G18/0819—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups
  • C08G18/0823—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups containing carboxylate salt groups or groups forming them
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
  • C09D175/04—Polyurethanes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
  • Y10T428/31605—Next to free metal

Definitions

• the invention relates to aqueous, one-component processable binder combinations for producing a coating that dries, can be sanded and is resistant to stone chips and weathering, and is resistant to stone chips, preferably in automotive serial painting and its production and use.
• a multi-layer structure of the top layers has become established in automotive serial painting, which is increasingly being achieved using aqueous coating agents. With such modern coatings, there are also demands on cost-effectiveness. The aim is to apply the coatings in as few and as inexpensive as possible individual steps.
• a stone chip protection layer and a filler layer or a combination of both (“stone chip protection coating”) is first applied to a metal surface primed by cathodic electrocoating (KTL).
• KTL cathodic electrocoating
• a base coat, then a clear coat or alternatively a pigmented coat is then applied to these layers Top coat applied.
• the stone chip protection and / or filler layer compensates for unevenness in the surface and, due to its high elasticity and deformability, provides good resistance to stone chips.
• soft polyester or polyether polyurethanes and polyisocyanate or melamine crosslinkers have therefore been used for this layer.
• the stone chip protection for the top coat is baked. This is necessary in order to improve the level of the top coat and to sand the filler coat before applying the top coat. After the clearcoat or topcoat has been applied, it is then baked again.
• a disadvantage of this process is that two complex baking processes with temperatures> 120 ° C are necessary. At lower ones
• Temperature-drying lacquers such as those formulated from polyacrylates can not have the required stone chip resistance, since they cross-link to brittle films.
• the present invention was based on the problem of finding a storage-stable, one-component processable coating formulation which, in addition to good stone chip resistance, ensures good sandability and surface hardness.
• the coating should be lightfast in order to produce a weather-resistant coating even in the case of moderately opaque topcoats or basecoats or in places where there is no pigmented topcoat or basecoat at all.
• an important requirement is the adhesion of the coating to various substrates, such as the plastics frequently used in automotive engineering (pretreated polypropylene or polyethylene, pretreated polypropylene / EPDM blends, polyurethane PJM, ABS, polybutylene terephthalate, polycarbonate, polyamide, SMC, BMC and others, as well as blends of the named plastics) as well as ferrous and non-ferrous metals and hardened lacquer layers of different binder bases.
• plastics frequently used in automotive engineering pretreated polypropylene or polyethylene, pretreated polypropylene / EPDM blends, polyurethane PJM, ABS, polybutylene terephthalate, polycarbonate, polyamide, SMC, BMC and others, as well as blends of the named plastics
• ferrous and non-ferrous metals and hardened lacquer layers of different binder bases such as the plastics frequently used in automotive engineering (pretreated polypropylene or polyethylene, pretreated polypropylene / EPDM blends
• Acid-functional polyesters are known to be poorly stable in storage because they are subject to rapid chemical degradation by cleavage of ester bonds. (e.g. Jones, T.E .; McCarthy, J.M., J. Coatings Technol. 76 (844), p. 57 (1995)).
• EP-A 0024727 describes a stoving lacquer based on a combination of epoxy resin-phosphoric acid ester, a water-dilutable polyester as well as water-soluble melamine resins.
• DE-A 4 000 748 describes aqueous automotive fillers based on water-dilutable, hydroxyl-functional polyester-polyurethane resins, optionally further binders and water-soluble amino resins.
• EP-A 0980 880 describes stone chip-resistant, physically drying coatings produced using polyacrylate dispersions in combination with polyurethane dispersions. However, these coatings have inadequate grindability.
• WO PCT / 00/01205 describes stone chip-resistant, physically drying coatings produced using polyacrylate dispersions. However, these combinations have weaknesses in stone chip resistance at temperatures below 0 ° C.
• the present invention was therefore also based on the object of providing aqueous, low-co-solvent, one-component, lightfast coating systems which are stable in storage and have improved sandability and good stone chip resistance at baking temperatures ⁇ 100.degree.
• the coating system is intended to offer adhesion to various substrates used in automobile construction. It has surprisingly been found that this object can be achieved by using a combination of special hard and highly elastic aqueous polyurethane dispersions which have almost no free OH groups and highly reactive water-dilutable melamine resins.
• the distinction between hard and soft dispersions can be made via the pendulum hardness of the films obtained by physical drying.
• the hard PUR dispersion A is characterized by a pendulum hardness according to König (DLN 53157) of> 90 s
• the soft PUR dispersion B is characterized by a pendulum hardness of ⁇ 90 s.
• dispersion A 20-90% by weight, but preferably 40-70% by weight, of dispersion A are used. From dispersion B, 10-80%, preferably 30-60% by weight are added. In addition, a reactive melamine resin is added in a proportion of 0-30% by weight, preferably between 5 and 20% by weight, for the crosslinking. The proportions of the 3 resin components add up to 100% binder.
• polyurethane dispersions are particularly suitable for such combinations
• WO PCT / 00/01205 as a highly elastic component and polyurethane dispersions analogous to EP-A 0269 972 as a hard component.
• the cited patent literature describes the production of the polyurethane dispersions in the so-called acetone process.
• Dispersions composed analogously, which are produced in the so-called melt dispersion process, are also suitable for use.
• the dispersions are preferably neutralized with tertiary amines such as, for example, triethylamine, diisopropylethylamine, morpholine.
• these binders can be combined with water-thinnable amino resins with a reactivity adapted to the baking temperature (e.g. Cymel ® 327, 328 - Cytec Industries BV, Rotterdam, Netherlands, Maprenal ® VMF 3921 W - Vianova Resins GmbH and Co. KG,
• This elastic polyurethane dispersion consists of 272 g of an aliphatic polycarbonate diol (Desmophen 2020 ® , Bayer AG, Leverkusen, DE, molecular weight 2000), 272 g of a polyester diol based on adipic acid, hexanediol, neopentyl glycol (molecular weight 1700) and 26, 8 g of dimethylolpropionic acid, which are weighed in under a nitrogen atmosphere and heated to 65 ° C.
• an aliphatic polycarbonate diol (Desmophen 2020 ® , Bayer AG, Leverkusen, DE, molecular weight 2000)
• 272 g of a polyester diol based on adipic acid hexanediol
• neopentyl glycol molecular weight 1700
• 26 8 g of dimethylolpropionic acid
• the resulting very fine-particle elastic polyurethane dispersion has a solids content of approx. 40% with a pH of approx. 7.7 and a viscosity of approx. 7800 mPa.s / 23 ° C.
• 35.8 g of the pigment grinding paste used as in Example 1 are mixed with 32.6 g of a 35% polyurethane dispersion (Bayhydrol ® PR 135), 28.6 g of a 40% elastic polyurethane dispersion according to EP A 0 330 139 (see Example 2 above) and 3.0 g of an 85% commercially available aqueous melamine resin
• a predispersed slurry consisting of 10.8 g 70% water-dilutable polyester resin (Bayhydrol ® D 270), 21.1 g dist. Water, 1.5 g of 10% - sodium dimethylethanolamine in water and 2.8 g of commercial wetting agent, 27.7 g of titanium dioxide (Tronox ® R-FD-I, Kerr McGee Pigments GmbH and Co. KG, Krefeld, DE), 0 , 3 g iron oxide black (Bayferrox ® 303 T Bayer Ag, Leverkusen, DE)), 27.9 g barium sulfate (Blanc fixe Micro, Sachtleben Chemie GmbH, Duisburg,
• lacquers are applied to the following substrates in a resulting dry film thickness of 25-35 ⁇ m using a flow cup spray gun with a nozzle diameter / 1.5 mm and an atomizing pressure of 5 bar.
• the wet paint films are flashed off at 23 ° C. for 5 minutes and then baked in a forced air oven.
• the substrates are glass plates in the case of tests of pendulum hardness and gloss, in the case of Hafumg / cross cut, Erichsen deepening and grindability, degreased steel sheets as well as KTL-coated steel sheets used in stone chip tests, which are used in automobile production.
• Example 5 according to the invention shows a good result with regard to stability, grindability and impact resistance. Without melamine resin, these mixtures are likewise stable and usable.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Manufacturing & Machinery (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2000
  • 2000-09-25 DE DE10047289A patent/DE10047289A1/de not_active Withdrawn
• 2001
  • 2001-09-12 CN CNB01816241XA patent/CN1205243C/zh not_active Expired - Fee Related
  • 2001-09-12 EP EP01980372A patent/EP1325048A1/de not_active Withdrawn
  • 2001-09-12 KR KR1020037004227A patent/KR100842603B1/ko not_active Expired - Fee Related
  • 2001-09-12 JP JP2002529187A patent/JP2004517975A/ja active Pending
  • 2001-09-12 CA CA002423160A patent/CA2423160A1/en not_active Abandoned
  • 2001-09-12 WO PCT/EP2001/010516 patent/WO2002024779A1/de not_active Ceased
  • 2001-09-12 AU AU2002212231A patent/AU2002212231A1/en not_active Abandoned
  • 2001-09-12 CZ CZ2003860A patent/CZ2003860A3/cs unknown
  • 2001-09-20 TW TW090123131A patent/TW584657B/zh not_active IP Right Cessation
  • 2001-09-20 US US09/960,034 patent/US6827983B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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