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
  • C08G18/8061—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
  • 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
  • C07C273/1818—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 -N=C=O and XNR'R"
  • C07C273/1827—X being H
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C275/00—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
  • C07C275/46—Derivatives of urea, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups containing any of the groups, X being a hetero atom, Y being any atom, e.g. acylureas
  • C07C275/58—Y being a hetero atom
  • C07C275/62—Y being a nitrogen atom, e.g. biuret
• • 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

Definitions

• the present invention relates to a novel process for the production of organic polyisocyanates containing polyurethane groups, the most important polyisocyanates obtainable by this process and the use of the process products as an isocyanate component in the production of polyurethane plastics.
• Polyisocyanates containing biuret groups are known and find practical use as raw materials for high-quality, lightfast coatings.
• they can be made from diisocyanates and water (DT-AS 1 101 394), hydrogen sulfide (DT-AS 1 165 580), formic acid (DT-AS 1 174 760), tertiary alcohols (DT-AS 1 543 178, DT-AS 1 931 055), monoamines (DT-OS 2 308 015) or polyamines (DT-OS 2 261 065).
• isocyanate groups initially form amino groups with over continue reacting liquid diisocyanate via the corresponding diisocyanate ureas to biuret polyisocyanates.
• the conversion of the isocyanate groups into amino groups is always accompanied by the formation of gaseous by-products such as carbon dioxide, carbon monoxide, carbon sulfoxide or olefins, the removal of which can lead to exhaust gas problems.
• gaseous by-products such as carbon dioxide, carbon monoxide, carbon sulfoxide or olefins
• the present invention relates to a process for the preparation of modified, triuret or higher polyuret groups having organic polyisocyanates, characterized in that primary or secondary monoamines with excess amounts of organic diisocyanates with formation of triuret or higher polyuret groups and incorporating the with respect to Implementation of indifferent residue of the amine in the process product brings to reaction.
• the present invention also relates to the use of the modified polyisocyanates obtainable by the process according to the invention as an isocyanate component in the production of polyurethane plastics by the isocyanate polyaddition process.
• Monoamines of the formula mentioned are preferably used in which R 1 and R 2 are identical or different radicals and are aliphatic hydrocarbon radicals having 1-4 carbon atoms, where R 1 can also represent hydrogen or in which R 1 and R 2 together with form a piperidine residue on the nitrogen atom.
• Very particularly preferred starting materials are the secondary monoamines corresponding to the above definition. Any mixtures of the amines mentioned can also be used. Specific examples of preferred or particularly preferred for the method according to the invention Suitable monoamines are: methylamine, ethylamine, propylamine, isopropylamine, isomeric butylamines, pentylamine, hexylamine, cyclohexylamine, dodecylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, bis- (2-ethylhexyl) amine, N-methylcyclohexylamine, N-ethylamine, cyclohexylamine -Methyloctadecylamine, pyrrolidine, piperidine etc.
• modified polyisocyanates containing triuret or higher polyuret groups are formed from the monoamines mentioned above and the diisocyanates mentioned below by way of example, in which the rest of the amine which is indifferent to the reaction is incorporated.
• This reaction proceeds via the intermediates of the compounds having urea groups which form from the amines and the diisocyanates or of compounds which have compounds with further diisocyanate and biuret groups which form from the urea groups.
• Intermediate stages are therefore the monourea monoisocyanates formed by addition of one mole of amine and one mole of diisocyanate, or also of bisheas formed from two moles of amine and one mole of diisocyanate, or the biuret polyisocyanates formed from these and further diisocyanate.
• a logical consequence of this fact is, of course, that as a starting material according to a modification of the method according to the invention, this also, for example, in a separate operation from the at monoamines mentioned by way of example and the intermediates prepared below by way of example isocyanates can be used.
• the type of manufacture of these intermediates is of no importance here.
• reaction product containing urea groups from one mole of hexamethylene-bis-carbamic acid chloride and 2 moles of a monoamine which corresponds to the reaction product containing urea groups from one mole of hexamethylene diisocyanate and 2 moles of the same monoamine.
• Diisocyanates suitable for the process according to the invention are any organic diisocyanates which, apart from the isocyanate groups, have no further groups which are reactive under the reaction conditions of the process according to the invention.
• Both the classic aromatic diisocyanates of polyurethane chemistry such as 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, mixtures consisting of these isomers or 4,4'-diisocyanatodiphenylmethane are suitable.
• diisocyanates with aliphatic and / or cycloaliphatic isocyanate groups are preferably used, in particular those in which the two isocyanate groups are linked via aliphatic hydrocarbon radicals with 4-12 carbon atoms or via cycloaliphatic hydrocarbon radicals with 4-15 carbon atoms, the aliphatic or cycloaliphatic hydrocarbon chains being interrupted by ester groups or can be substituted, such as: 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-di-isocyanatohexane, 1,11-diisocyanatoundecane, 3-isocyanatomethyl-3,5, 5-trimethylcyclohexyl isocyanate, 4,4'-cyclohexane diisocyanate, 4,4'- Dicyclohexylmethane diisocyanate, 1,2-bis (isocyanatomethyl) cyclobutan
• diisocyanate mixtures can also be used, e.g. a urea or a biuret are first produced from a diisocyanate with a monofunctional amine, which then form polyurets with another diisocyanate.
• the catalysts to be used according to the invention are proton-releasing strong acids which react with isocyanates, in particular with aliphatic or cycloaliphatic isocyanates, to form a mixed acid anhydride, the carbamic acid corresponding to the isocyanate and the proton-releasing acid being the acids represent the mixed acid anhydride.
• suitable Ter acids are hydrogen halides such as hydrogen fluoride, hydrogen chloride, hydrogen bromide or hydrogen iodide, chlorosulfonic acid, fluorosulfonic acid, sulfuric acid, alkanesulfonic acids such as methanesulfonic acid or perhalogenated alkanesulfonic acids such as trifluoromethanesulfonic acid.
• Hydrogen chloride is the preferred acid to be used in the process according to the invention.
• both the ammonium salts corresponding to the acids with the amines used as starting material or the mixed carbamic acid anhydrides corresponding to the acids, in particular carbamic acid chlorides, the diisocyanates used as starting material or any other isocyanate can of course be used in the process according to the invention.
• the catalysts are used in amounts of 0.001-10, preferably 0.01-1.0% by weight, based on the total weight of the reactants.
• these and the diisocyanates are generally used in proportions which have an NCO / NH molar ratio of 5.5: 1 to 100: 1, preferably 6: 1 to 30: 1, correspond.
• starting materials containing urea groups ie mono urea monoisocyanates or bis-ureas formed from monoamines and diisocyanates, appropriate quantitative ratios are used, taking into account that in the starting materials containing urea groups already monoamines and diisocyanates in a molar ratio of 1: 1 or 2: 1 are present.
• the reaction is terminated. This is done simply by cooling the reaction mixture to 20-50 ° C.
• the reaction times required depend on the nature of the starting materials on temperature and in particular of the A rt and amount of catalyst used. They are generally 1-20, preferably 2-8, hours. After the reaction has ended, clear, colorless to slightly yellowish reaction solutions are obtained.
• the reactions are usually ended at a point in time when an average of about 3 NCO groups are used per amino group.
• the products then have an average functionality of 3.5, taking into account the polymer homologue.
• it is possible to achieve a higher "degree of polyuretization", i.e. to implement 4 and more NCO groups per amino group.
• the viscosities of the products then increase quickly.
• the catalyst is generally removed by distilling the reaction mixture in vacuo. If hydrogen halides are used as catalysts, removal, in particular in the case of smaller amounts of catalyst, can also be carried out by adding equimolar amounts of propylene oxide. It is also possible to remove the catalyst by, for example, thin-layer evaporation if the crude isocyanate is freed from excess diisocyanate. The distillate of thin-film distillation, which is then next to the diisocyanate contains the catalyst, can be reused as starting material.
• the removal of excess diisocyanate is provided, it is usually carried out by thin-layer evaporation; however, it can also be extracted by extraction of the reaction mixture with suitable solvents, e.g. Hexane, heptane etc. can be achieved.
• suitable solvents e.g. Hexane, heptane etc.
• the crude isocyanates can be used as such. In most cases, however, they are preferably freed from monomeric isocyanate fractions by thin-layer evaporation or extraction.
• the monomer-free products are light yellow oils or solid resins; the NCO content is 10-22%.
• the process is ideal for a continuous implementation.
• several reaction vessels are cascaded together.
• the starting products diisocyanate and amine are mixed at about 60 ° C.
• the catalyst is added at about 80 ° C. in the second reaction vessel.
• the further reaction to the polyisocyanate takes place at about 90-140 ° C., the desired degree of “polyurethaneisation” being set by controlling the temperature and the residence time.
• Excess diisocyanate and the catalyst are removed, for example, using a coiled tube evaporator combined with a downstream thin-film evaporator.
• the distillates consisting of diisocyanate and catalyst are combined and returned to the process.
• the polyisocyanate is obtained as a residue of the thin film distillation.
• monoisocyanates are not split off when the process according to the invention is carried out. However, it can take place in part if the process product according to the invention is freed from excess diisocyanate at elevated temperature (about 170 ° C.) by thin-layer evaporation after the reaction has ended. For this reason, when using primary monoamines as starting materials, it is recommended to remove the excess, unreacted diisocyanate by extraction with suitable solvents, such as n-hexane. If secondary monoamines are used as starting materials, such an extraction is not necessary, since in this case the elimination of monoisocyanate is impossible due to the different structure of the reaction products.
• the properties of the modified polyisocyanates obtained, in particular their NCO functionality, NCO content, and the viscosity can be adjusted not only by selecting the suitable starting materials but also particularly simply by adjusting the "degree of polyuretization", i.e. the number of NCO groups converted per amino group can be controlled.
• the process products according to the invention can be used in particular as an isocyanate component in the production of polyurethane plastics by the ilocyanate polyaddition process. They are suitable for the production of polyurethane foams as well as for the production of elastomers, coatings or bonds.
• the monomer-free process products according to the invention are excellent raw materials for producing high-quality, weatherproof and lightfast coatings. This applies in particular to the process products according to the invention which have been produced using only aliphatic or cycloaliphatic starting materials.
• the reaction solution was cooled to 50 ° C. and 11 g (0.19 mol) of propylene oxide were added to bind the hydrolyzable chlorine.
• Example 5 154 g of the polyester solution described in Example 5 were processed with 100 g of titanium dioxide (rutile type) to form a paste. In addition to the catalyst and leveling agent, 120 g of the solvent mixture already described were added to this paste. The mixture thus obtained was mixed with 135 g of a 75% solution of the polyisocyanate from Example 1 in ethyl glycol acetate / xylene (1: 1) and applied in a thin layer to steel sheets.
• the paint films containing pigment hardened completely at room temperature. They were characterized by scratch resistance and solvent resistance and had the following properties compared to the clear lacquer films:

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• 1977
  • 1977-07-06 DE DE19772730513 patent/DE2730513A1/de not_active Withdrawn
• 1978
  • 1978-06-21 US US05/917,765 patent/US4220749A/en not_active Expired - Lifetime
  • 1978-06-28 DE DE7878100256T patent/DE2860054D1/de not_active Expired
  • 1978-06-28 EP EP78100256A patent/EP0000348B1/fr not_active Expired
  • 1978-07-03 NZ NZ187758A patent/NZ187758A/xx unknown
  • 1978-07-04 IT IT7850153A patent/IT7850153A0/it unknown
  • 1978-07-04 JP JP8060378A patent/JPS5414922A/ja active Pending
  • 1978-07-06 ES ES471506A patent/ES471506A1/es not_active Expired

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