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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/80—Masked polyisocyanates
• • 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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/80—Masked polyisocyanates
  • C08G18/8061—Masked polyisocyanates masked with compounds having only one group containing active hydrogen
  • C08G18/807—Masked polyisocyanates masked with compounds having only one group containing active hydrogen with nitrogen containing compounds
  • C08G18/808—Monoamines
• • 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
  • C08G18/30—Low-molecular-weight compounds
  • C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
  • C08G18/3271—Hydroxyamines
  • C08G18/3275—Hydroxyamines containing two hydroxy groups
• • 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
  • C08G18/40—High-molecular-weight compounds
  • C08G18/4009—Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
  • C08G18/4063—Mixtures of compounds of group C08G18/62 with other macromolecular compounds
• • 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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
  • C08G18/78—Nitrogen
  • C08G18/79—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates
  • C08G18/791—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups
  • C08G18/792—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• • 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
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/80—Masked polyisocyanates
  • C08G18/8003—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen
  • C08G18/8048—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/34
• • 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.]

Definitions

• the invention relates to aqueous and / or water-dilutable polyisocyanate crosslinking agents blocked with diisopropylamine, their preparation and use in one-component stoving lacquers, e.g. as a filler in automotive painting.
• isocyanate blocking agents that meet these requirements. Butanone oxime is such a blocking agent, but it needs baking conditions of at least 30 minutes / 140 ° C to ensure the crosslinking of the blocked polyisocyanate.
• 3,5-Dimethylpyrazole is also a suitable blocking agent and already leads to crosslinking of the blocked polyisocyanate under baking conditions of 30 minutes / 130 ° C, e.g. is discussed in patent applications WO97 / 12924 and EP-A 0942 023.
• the disadvantage of 3,5-dimethylpyrazole is its relatively complex preparation. 3,5-Dimethylpyrazole is accessible on an industrial scale by condensation of acetylacetone and hydrazine hydrate, which is due to e.g. the properties of hydrazine hydrate is complex.
• a readily accessible isocyanate blocking agent is diisopropylamine. From the patent literature it is known that it is used in powder coatings and coil coating coatings, see EP-A 0096 210 and EP-A 900814. It has surprisingly been found that polyisocyanates blocked with diisopropylamine are stable in storage in the aqueous phase and do not continuously secrete CO 2 , as is the case for example with polyisocyanates blocked with diethyl malonate or 1,2,4-triazole.
• the object of the invention is to provide storage-stable and easily accessible aqueous or water-dilutable blocked polyisocyanate crosslinkers with a lower crosslinking or baking temperature than butanone oxime-blocked polyisocyanate crosslinkers.
• the invention relates to aqueous and / or water-dilutable blocked polyisocyanate crosslinkers
• the proportions of the reactants being chosen so that the equivalent ratio of NCO groups of component a) to isocyanate-reactive groups of components b), c), and d) is from 1: 0.8 to 1: 1.2 lies, and optionally additives and auxiliaries.
• the invention also relates to a process for the preparation of the blocked aqueous and / or water-dilutable polyisocyanate crosslinking agent, characterized in that the polyisocyanate component a) and optionally 30% by weight, moved to the delivery form of the blocked polyisocyanate crosslinker, a water-miscible solvent, are reacted in a first reaction stage at approx. 80 ° C with the monohydroxycarboxylic acid intended for hydrophilization, then cooled to approx. 50 ° C and the remaining NCO- Groups can be blocked by adding diisopropylamine.
• the blocked aqueous / water-dilutable polyisocyanate crosslinker according to the invention can be prepared in stages, e.g. the polyisocyanate component a) and optionally 30% by weight, based on the delivery form of the crosslinking agent, of a water-miscible solvent, e.g. N-methylpyrrolidone, are introduced and reacted in a first reaction stage at about 80 ° C. with the monohydroxycarboxylic acid provided for the hydrophilization. The mixture is then cooled to about 50 ° C. and the remaining NCO groups, about 80%, are completely reacted with diisopropylamine.
• a water-miscible solvent e.g. N-methylpyrrolidone
• the hydrophilization is to be achieved with a dihydroxycarboxylic acid or a mixture of di- and monohydroxycarboxylic acid, e.g. conversely, the blocking reaction with diisopropylamine is carried out first at approx. 40-70 ° C; the remaining NCO groups are then used to react with the hydrophilization component. In this way, the formation of networked
• tertiary amine for example dimethylethanolamine
• the carboxylic acid groups are converted into hydrophilic carboxylate anions.
• a water-dilutable blocked polyisocyanate crosslinker with approx. 65% solids content and a viscosity (at 23 ° C) of approx. 10,000 mPas, for example by adding further water-miscible solvent or by adding water to a water-dispersed blocked crosslinker with approx 30% solids content and a viscosity (at 23 ° C) of approx. 400 mPas.
• the invention also relates to the use of the aqueous and / or water-dilutable blocked polyisocyanate crosslinking agent according to the invention in combination with water-soluble and / or dispersible polyhydroxy compounds for the preparation of aqueous stoving lacquers which optionally contain the conventional auxiliaries and additives of coating technology , They are preferably used in automotive painting.
• the polyisocyanates a) on which the blocked polyisocyanates according to the invention are based are lacquer polyisocyanates known per se with aliphatic and / or cycloaliphatic isocyanate groups and an isocyanate content of 7 to 30, preferably 12 to 25,% by weight.
• HDI 1,6-diisocyanatohexane
• LPDI 1-isocyanato-3,3, 5-trimethyl-5-isocyanatomethyl-cyclohexane
• H 12 MDI bis- (4-isocyanatocyclohexyl) methane
• polyisocyanates or short-chain NCO prepolymers based on aromatic diisocyanates such as, for example, diisocyanatotoluene (TDI) or 4,4-diisocyanatodiphenylmethane (MDI).
• TDI diisocyanatotoluene
• MDI 4,4-diisocyanatodiphenylmethane
• component a Particularly preferred as component a), however, are polyisocyanates based on HDI or H 12 MDI and containing isocyanurate groups.
• Diisopropylamine is suitable according to the invention as a blocking agent from the series of secondary amines. Under the technically required baking conditions of 130 ° C / 30 minutes, it is substituted or deblocked and blocked in aqueous varnishes, just like butanone oxime or 3,5-dimethylpyrazole, isocyanate groups without the release of CO 2 as a result of hydrolysis. Monohydroxy- and di-hydroxycarboxylic acids which carry one or two ⁇ -methyl groups are preferred as the hydrophilization component c). Hydroxypivalic acid (hydroxymethyldimethylacetic acid) and mixtures of hydroxypivalic acid with dimethylolpropionic acid are particularly preferred.
• Suitable difunctional chain extension components d) are diamines, diols and also hydroxyamines in the molecular weight range from 32 to 300.
• Examples are hydrazine, ethylenediamine, isophoronediamine, the bisketimine from isophorondiamine and methyl isobutyl ketone, 1,4-dihydroxybutane, ethanolamine, N-methylethanolamine, hydroxyethylethylenediamine, the adduct of 2 mol propylene carbonate and 1 mol hydrazine of the formula (I)
• Suitable neutralizing agents are e.g. Dimethylethanolamine, methyldiethanolamin, triethylamine, N-methylmo holin or 2-amino-2-methylpropanol.
• stabilizers e.g. Hydrazides and HALS amines (hindered amines
• Light Stabilizers of the type Tinuvin® 770 DF. Additives and other auxiliaries can also be added.
• crosslinking agents according to the invention can either be up to 80% pure in a water-dilutable solvent or up to 50% pure mainly in water
• water-dilutable solvents e.g. Butyl diglycol acetate, butly diglycol, N-methylpyrrolidone, or any mixture thereof.
• the polyisocyanate crosslinkers according to the invention have the following advantages:
• the crosslinkers and the aqueous stoving enamels formulated with them are stable on storage for at least 3 months.
• the blocking agent diisopropylamine is an inexpensive industrial chemical.
• the baking temperature of the aqueous varnish is 30 minutes / 130 ° C and thus 10 ° C lower than that of a butanone oxime-blocked crosslinker.
• NCO content of 21.4% by weight, a viscosity at 23 ° C of approx. 3000 mPas and a functionality of approx. 3.5
• Polyisocyanate, N-methylpyrrolidone and hydroxypivalic acid are heated at intervals to 80 ° C. with stirring. At this temperature, stirring is continued for about 2 hours until the NCO content has dropped to about 9.1%. Then leave on approx.
• Polyisocyanate is introduced and stirred. To do this, carefully drop diisopropylamine starting from room temperature. The implementation is exothermic, whereby keeping the temperature at 70 ° C. The addition of diisopropylamine is complete after about 1 hour.
• the solution of hydroxypivalic acid, dimethylolpropionic acid and N-methylpyrrolidone is added, the mixture is heated to 80 ° C. and stirred at this temperature for about 2 hours until NCO groups are no longer detectable by IR spectroscopy. Thereafter, the supply of heat is stopped, dimethylethanolamine is added, the mixture is stirred for a further 10 minutes and water, at 50 ° C., is stirred. A dispersion is formed, which is stirred at about 50 ° C for 3 hours. The mixture is then cooled to room temperature with stirring and stirring is continued for 3 hours.
• the dispersed blocked polyisocyanate crosslinker has the above characteristics.
• This crosslinker blocked with butanone oxime is constructed analogously to that described in Example 2. It is characterized as follows:
• Solids content 41% viscosity at 23 ° C: approx. 5700 mPas Blocked NCO content: 3.9
• the paint components in the overview above are mixed intimately using a stirrer.
• the OH components and the blocked crosslinkers are metered in an equivalent ratio of 1: 1.
• the addition of melamine resin improves the smooth surface quality.
• the three above 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 adhesion / cross cut, Erichsen cupping and salt spray test, degreased steel sheets:
• Pendulum hardness Vibration test according to König DIN 53 157
• lacquers 1 and 2 with the crosslinkers according to the invention are more reactive than lacquer 3 with the butanone oxime-blocked polyisocyanate crosslinker.
• the higher reactivity which is based on the blocking agent diisopropylamine, is evident from the higher paint hardness, the better resistance to solvents and the improved corrosion resistance (less paint infiltration of the salt solution).

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

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• 2001
  • 2001-07-13 DE DE10134238A patent/DE10134238A1/de not_active Withdrawn
• 2002
  • 2002-07-01 CA CA002453432A patent/CA2453432A1/en not_active Abandoned
  • 2002-07-01 MX MXPA04000333A patent/MXPA04000333A/es active IP Right Grant
  • 2002-07-01 KR KR10-2004-7000439A patent/KR20040018452A/ko not_active Application Discontinuation
  • 2002-07-01 EP EP02784829A patent/EP1409565A1/de not_active Withdrawn
  • 2002-07-01 JP JP2003512291A patent/JP2004534134A/ja active Pending
  • 2002-07-01 CN CNB028179633A patent/CN1310995C/zh not_active Expired - Fee Related
  • 2002-07-01 BR BR0211092-0A patent/BR0211092A/pt not_active IP Right Cessation
  • 2002-07-01 WO PCT/EP2002/007231 patent/WO2003006524A1/de not_active Application Discontinuation
  • 2002-07-10 US US10/192,446 patent/US6716910B2/en not_active Expired - Fee Related
  • 2002-07-11 AR ARP020102594A patent/AR036163A1/es active IP Right Grant

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