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
  • C08G18/8003—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen
  • C08G18/8054—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/38
  • C08G18/8058—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/38 with compounds of C08G18/3819
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
  • C07C273/18—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas
  • C07C273/1809—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas with formation of the N-C(O)-N moiety
  • C07C273/1836—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas with formation of the N-C(O)-N moiety from derivatives of carbamic acid
• • 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
  • C08G18/7806—Nitrogen containing -N-C=0 groups
  • C08G18/7818—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative 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
  • C08G18/70—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
  • C08G18/7806—Nitrogen containing -N-C=0 groups
  • C08G18/7818—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups
  • C08G18/7837—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups containing allophanate groups

Definitions

• the present invention relates to a new process for the preparation of new allophanate organic polyisocyanates having at least three isocyanate groups, the polyisocyanates obtainable by this process and their use as structural components in the production of polyurethane plastics.
• Organic polyisocyanates with allophanate groups and aliphatically bonded isocyanate groups have become known, for example, from GB-PS 994 890.
• polyisocyanates containing urethane groups from simple mono- or polyhydric alcohols and organic polyisocyanates, in particular diisocyanates are reacted by heating to elevated temperatures for several hours or, in the presence of catalysts, with further amounts of organic polyisocyanates, preferably diisocyanates, to form the allophanate group-containing polyisocyanates.
• a disadvantage of this process, in addition to the use of catalysts, is in particular the long heating time during the allophanatization reaction, which generally discolored Leads reaction products.
• the present invention also relates to the new polyisocyanates obtainable by this process and their use as a structural component in the production of polyurethane plastics by the isocyanate polyaddition process.
• R 1 and R 2 have the meaning given and for which three of the radicals R 3 and R 4 are very particularly preferred.
• R 5 and R 6 are hydrogen and one of the radicals mentioned is a methyl or hydroxymethyl group.
• suitable compounds for the process according to the invention are of course also those compounds of the general formula mentioned in which the radicals R 1 to R 6 have substituents which are inert under the process conditions, such as, for example, alkoxy groups or halogen atoms.
• the compounds of the general formula mentioned which contain essential hydroxyl groups can easily be obtained by reacting compounds of the formula having amino groups with cyclic carbonates of the formula be preserved.
• R 1 to R 6 have the meaning given above.
• suitable compounds having amino groups are ammonia, methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, isobutylamine, tert-butylamine, pentylamine, tert-pentylamine, hexylamine, 2-ethylhexylamine, dodecylamine, tetradecylamine, hexadecylamine , 2-propenylamine, cyclohexylamine, 2 (or 3 or 4) methylcyclohexylamine, aminomethylcyclohexylamine, 3,3,5-trimethylcyclohexylamine, 2-norbornylmethylamine, 2-aminethanol, 3-amino-1-propanol, 1-amino-2- propanol, 4-amino-2-butanol, 3-amino-1-butanol, 2-amino-1-butanol, 3-amino-3
• Suitable cyclic carbonates are 1,3-dioxolan-2-one, 4-methyl-1,3-dioxolan-2-one, 5-methyl-1,3-dioxan-2-one, 5-dimethyl-1,3 -dioxan-2-one, 5-ethyl-1,3-dioxan-2-one, 5-di- ethyl-1,3-dioxan-2-one, 4-hydroxymethyl-1,3-dioxolan-2-one and 2,4-dioxa-bicyclo-4,3,0-nonan-3-one.
• the compounds containing hydroxyl groups which are essential to the invention, are generally prepared at 20 to 100 ° C., preferably 30 to 50 ° C., by reacting equimolar amounts of the compounds containing amino groups mentioned as examples with the cyclic carbonates mentioned as examples.
• Any organic polyisocyanates are suitable for the process according to the invention.
• these are ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4- (2,4,4) -trimethylhexy-methylene diisocyanate-1,6, 1,12-dodecane diisocyanate, lysine diisocyanate C 1 -C 8 alkyl ester , Cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and any mixtures of these isomers, 2,4- and 2,6-hexahydrotoluenediisocyanate and any mixtures of these isomers, 3,3'-dimethyl -4,4'-diisocyanatodicyclohexylmethane, 4,4'-diisocyana
• Hexamethylene diisocyanate and 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane are preferably used.
• the process according to the invention is carried out in the temperature range from 90-200 ° C., preferably 100-180 ° C.
• the reactants are used in proportions which correspond to an NCO / OH equivalent ratio of at least 4: 1, preferably 6: 1 to 25: 1.
• the process according to the invention can also be carried out in two stages in the same way, the starting components being stirred together at room temperature and then being heated together to the above-mentioned temperature range of 100-180.degree.
• a solvent which is inert to isocyanates e.g. Ethyl acetate, butyl acetate, toluene or xylene is possible.
• the process according to the invention is preferably carried out without solvents.
• the process products are viscous, colorless to yellow-colored polyisocyanates, which are liquid at room temperature or all solid hard resins are present. They are completely odorless and clearly possible in solvents which are inert to NCO groups, such as hydrocarbons, chlorinated hydrocarbons, esters and ketones.
• urethane groups initially form from the hydroxyl groups of the compound having essential hydroxyl groups and part of the isocyanate groups of the diisocyanate.
• These polyisocyanates thus containing intermediate urethane groups are formed already in the temperature range between 50 and 100 ° C and can be isolated with appropriate temperature control, since at these temperatures essentially no allophanatization occurs.
• At a higher temperature, above 100 ° C further diisocyanate is added to the primary groups to form allophanates.
• urethanization of the OH function and allophanatization proceed non-selectively and side by side.
• the aforementioned selective reaction control by appropriate control of the reaction temperatures opens up the interesting possibility of building up polyisocyanates having allophanate groups and having a defined structure in which, for example, both aliphatic and cycloaliphatic isocyanate groups are present.
• the excess diisocyanate which may still be present can be separated off by distillation, for example in thin-film evaporators, after the reaction according to the invention.
• the process products according to the invention are valuable starting materials for the production of polyurethane plastics by the isocyanate polyaddition process, in particular for the production of one- or two-component polyurethane lacquers.
• the process products according to the invention are also particularly suitable for the production of polyurethane stoving lacquers.
• Preferred reactants for the process products according to the invention, optionally in blocked form, in the production of polyurethane lacquers are the polyhydroxy polyesters, polyhydroxy polyacrylates known per se in polyurethane lacquer technology, and optionally low molecular weight, polyhydric alcohols. Suitable reaction partners of this type are described, for example, in DT-AS 2 304 893.
• the proportions in which the optionally blocked polyisocyanates according to the invention and the reactants mentioned are reacted in the production of polyurethane lacquers are generally chosen so that 0.8-3, preferably 0.9-1, to an (optionally blocked) isocyanate group 1, hydroxyl, amino, mercapto and / or carboxyl groups are eliminated.
• the catalysts customary in isocyanate chemistry, such as, for example, tert.
• Amines such as triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N-dimethylaminocyclo- hexane, N-methylpiperidine, pentamethyldiethylenetriamine, N, N'-endoethylene piperazine, N, N'-dimethylpiperazine etc.
• metal salts such as iron (III) chloride, zinc chloride, zinc 2-ethyl caproate, tin (II) -2-ethyl caproate, Dibutyltin (IV) dilaurate, molybdenum glycolate, etc.
• NCO groups per OH group are reacted in a quantity ratio that accounts for at least 1.2, preferably 1.5 to 10, NCO groups per OH group.
• paint binders with free NCO groups are created, which harden in moist air to form hard, shiny and high-quality coatings.
• the catalysts mentioned can also be used in one-component paints.
• the NCO groups are blocked in whole or in part in a known manner.
• the polyisocyanate is treated with a suitable blocking agent, preferably at elevated temperature (e.g. 40 to 140 ° C), optionally in the presence of a suitable catalyst, e.g. tert.
• a suitable blocking agent preferably at elevated temperature (e.g. 40 to 140 ° C)
• a suitable catalyst e.g. tert.
• Amines, metal salts such as zinc 2-ethyl caproate, tin (II) -2-ethyl caproate, dibutyl tin (IV) dilaurate or alkali metal phenolate.
• the paints and coatings can be in solvent-free liquid form or in solution or from the melt, or in solid form by the customary methods, e.g. Brushing, rolling, pouring, spraying, the vortex sintering process or the electrostatic powder spraying process can be applied to the object to be coated.
• the lacquers containing the polyisocyanates according to the invention produce films which adhere surprisingly well to metallic substrates, are particularly lightfast, stable to heat colors and very are abrasion-resistant and, if they are used in air-drying paints, dry particularly quickly, even at temperatures around 0 ° C. In addition, they are characterized by great hardness, elasticity, very good chemical resistance, high gloss, excellent weather resistance and good pigmentability.
• the stability of the polyisocyanates shown is checked by annealing at 50 ° C. for several weeks and then analyzing the samples for their content of monomeric isocyanate by gas chromatography. This experiment shows particularly clearly that the products of the process according to the invention are largely stable against monomer cleavage, which is a particularly important physiological criterion for their suitability as paint polyisocyanate.

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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)
• Polyurethanes Or Polyureas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=6010745

Family Applications (1)

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Cited By (6)

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Citations (1)

Family Cites Families (8)

• 1977
  • 1977-06-04 DE DE19772725318 patent/DE2725318A1/de not_active Withdrawn
• 1978
  • 1978-05-24 US US05/909,239 patent/US4177342A/en not_active Expired - Lifetime
  • 1978-06-01 EP EP78100028A patent/EP0000016B1/fr not_active Expired
  • 1978-06-01 DE DE7878100028T patent/DE2860034D1/de not_active Expired
  • 1978-06-02 JP JP6587578A patent/JPS543013A/ja active Granted
  • 1978-06-02 ES ES470460A patent/ES470460A1/es not_active Expired
  • 1978-06-02 IT IT7849672A patent/IT7849672A0/it unknown

Patent Citations (1)

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