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 new organic polyisocyanates containing polyurethane groups, a novel process for their preparation and the use of the new compounds 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. You can, for example, from diisocyanates and water (DT-AS 1 101 394), hydrogen sulfide (DT-AS 1 165 580), formic acid (DT-AS 1 174760), tertiary alcohols (DT-AS 1 543 178, DT-AS 1 931 055, monoamines (DT-OS 2308015) or polyamines (DT-OS 2 261 065).
• diisocyanates and water DT-AS 1 101 394
• hydrogen sulfide DT-AS 1 165 580
• formic acid DT-AS 1 174760
• tertiary alcohols DT-AS 1 543 178
• DT-AS 1 931 055 monoamines
• DT-OS 2308015 monoamines
• polyamines DT-OS 2 261 065
• the isocyanate groups initially form amino groups, which react further with excess diisocyanate via the corresponding diisocyanate ureas to form 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 also relates to the use of the new compounds as an isocyanate component in the production of polyurethane plastics by the isocyanate polyaddition process.
• Suitable monoamines are: dimethylamine, diethylamine, dipropylamine, dibutylamine or piperidine.
• 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 takes place via the intermediate stages of the compounds having urea groups which form from the amines and the diisocyanates or the compounds which have urea groups and compounds having further diurayate-forming biuret groups.
• Intermediate stages are therefore the monourea monoisocyanates formed by the 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 process according to the invention, these can also be used, for example, in a separate operation from the intermediates prepared in the example of monoamines and the isocyanates mentioned below as examples.
• 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.
• Ge for the inventive process - suitable diisocyanates are those having aliphatically and / or cycloaliphatically attached isocyanate groups, in particular those in which the two isocyanate groups are connected via aliphatic hydrocarbon radicals having 4-12 carbon atoms or cycloaliphatic hydrocarbon radicals having 4-15 carbon atoms, wherein the aliphatic or Cycloaliphatic hydrocarbon chains can be interrupted or substituted by ester groups, such as: 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-di-isocyanatohexane, 1,11-diisocyanatoundecane, 3-isocyanatomethyl -3,5,5-trimethylcydohexyl isocyanate, 4,4'-cydohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,2-bis
• 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 in accordance with 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 of the mixed acid anhydride.
• suitable acids are hydrogen halides such as e.g. Hydrogen fluoride, hydrogen chloride, hydrogen bromide or hydrogen iodine, chlorosulfonic acid, fluorosulfonic acid, sulfuric acid, alkanesulfonic acids such as e.g. Methanesulfonic acid or perhalogenated alkanesulfonic acids such as e.g. Trifluoromethanesulfonic acid.
• Hydrogen chloride is the preferred acid to be used in the process according to the invention.
• 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.
• the process according to the invention can be carried out, in particular, using the acids mentioned as examples as catalysts at relatively low temperatures in the range from about 0-140 ° C., the reaction leading to triuret and polyuret groups having reaction products going beyond the stage of the biuret polyisocyanates in general Range between 90 and 140 ° C expires.
• the catalysis according to the invention with the acids mentioned by way of example thus permits, under mild reaction conditions, the preparation of isocyanate addition products containing polyurethane groups from organic diisocyanates and organic monoamines or urea groups or compounds having biuret groups formed from monoamines and diisocyanates.
• monoamines no volatile by-products arise due to the mild reaction conditions.
• the remainder of the monoamines which are indifferent to the implementation of the invention, thus always forms part of the process products of the invention.
• 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 i.e.
• Corresponding quantitative ratios of monourea monoisocyanates or bis-ureas formed from monoamines and diisocyanates are used, taking into account that monoamines and diisocyanates in a molar ratio of 1: 1 or 2: 1 are already present in the starting materials containing urea groups.
• the reaction is terminated. This is done simply by cooling the reaction mixture to 20-50 ° C.
• the reaction times required depend on the type of starting products, on the temperature and in particular on the type and amount of the 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 on average about 3 NCO groups have been consumed 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. 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, the 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 e.g. Remove thin film evaporation if the crude isocyanate is freed from excess diisocyanate. The distillate from the thin-film distillation, which then contains the catalyst in addition to the diisocyanate, can be reused as the starting material.
• the removal of excess diisocyanate is usually done 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 continuous implementation. In these cases, several reaction vessels are cascaded together. In the first reaction vessel, the starting products diisocyanate and amine are mixed at approx. 60 ° C. The catalyst is added at about 80 ° C. in the second reaction vessel. In the third and optionally further reaction vessels, the further reaction to the polyisocyanate takes place at approx. 90-140 ° C., the desired degree of “polyurethaneisation” being set by controlling the temperature and the residence time.
• Excess diisocyanate and the catalyst are e.g. removed via 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 the residue of thin-film distillation.
• 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 isocyanate polyaddition process. They are both suitable for the production of poly. urethane foams, as well as for the production of elastomers, coatings or bonds. In particular when using the process products according to the invention for the first-mentioned area of application, it is often unnecessary to distill off the excess diisocyanate after the reaction according to the invention has ended.
• the monomer-free process products according to the invention are excellent raw materials for producing high-quality, weatherproof and lightfast coatings.
• 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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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Polyurethanes Or Polyureas (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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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/de 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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