摘要:
Polyamines containing aromatically bound primary amino groups having an NH.sub.2 -content of from 0.19 to 20.3 wt % are produced by a single stage process. A compound containing aromatically bound NCO-groups and having an isocyanate content of from 0.5 to 40 wt % is hydrolyzed with an excess of water in the presence of a water-miscible polar solvent and optionally a catalyst. The hydrolysis is carried out at a temperature of from -10.degree. to 150.degree. C. in a manner such that the reaction mixture is substantially homogeneous. The water-miscible polar solvent generally has a boiling point of from 56.degree. to 250.degree. C. and a dielectric constant of at least 10. This polar solvent is used in a quantity of at least 5 parts solvent for every 100 parts of isocyanate. Tertiary amines are the preferred catalysts. These polyamines are particularly useful in the production of polyurethanes.
摘要:
Polyamines containing from 0.19 to 20.3 wt. % aromatically bound primary amino groups are produced by hydrolyzing an isocyanate group containing compound in the presence of excess water, a tertiary amine and, optionally an ether solvent. The hydrolysis is carried out at a temperature of from -10.degree. to 150.degree. C. in a manner such that the reaction mixture remains substantially homogeneous. The isocyanate starting material contains aromatically bound isocyanate groups and has an NCO-content of from 0.5 to 40 wt. %. The ether solvent must be water soluble and inert with respect to isocyanates. Co-solvents and catalysts may also be included in the reaction mixture. The product polyamines are particularly useful in the production of polyurethanes.
摘要:
This invention relates to a process for the production of non-cellular polyurethane ureas elastomers using a chain-extender mixture produced from asymmetrically alkyl-substituted anilines by condensation with formaldehyde. The chain-extending agents used in the instant invention show medium reactivity to compounds containing isocyanate groups. These chain-extending agents may be processed both in high-pressure and in low-pressure metering and mixing units because they are either liquid at room temperature or can be melted at relatively low temperatures (below 55.degree. C.). The homogeneous, i.e. non-cellular, polyurethane urea elastomers obtained in the instant invention are distinguished by having excellent mechanical properties.
摘要:
The invention relates to an improved process for the production of polyamines containing urethane and/or urea and/or biuret and/or isocyanurate groups and, preferably, also alkylene ether, carbonate and/or acetal groups by the alkaline hydrolysis of corresponding compounds containing terminal aliphatic and/or aromatic isocyanate groups.To this end, the compounds containing terminal NCO-groups, preferably NCO-preadducts, are converted by means of selected bases into the carbamates and neutralized by introduction into equivalent quantities of acid or by the simultaneous introduction of the components in equivalent quantities into a reaction vessel, after which the polyamines are directly isolated by methods known per se.The invention also relates to the use of the polyamines obtained by the process for the production of polyurethanes.
摘要:
A compound having a terminal isocyanate group is hydrolyzed to produce a polyamine having a urethane and/or a urea and/or a biuret group. More particularly, a carbamate is made by mixing an isocyanate prepolymer having urethane and/or urea and/or biuret groups present with aqueous base solutions at a temperature of from 0.degree. to 0.degree. C. and in quantities such that the equivalent ratio of hydroxyl to isocyanate groups is between from 0.3:1 to .gtoreq.1.01 to 1. The carbamate is then treated with an acid ion exchanger to form an amine. The amine is then removed from any other material which may be present. A preferred polyamine thus-produced corresponds to the general formula: ##STR1## in which each R radical may represent a divalent straight or branched-chain aliphatic radical; a divalent cycloaliphatic radical; a 4,4'- and/or a 2,4'-dicyclohexylmethane radical; or a 2,4- and/or 2,6-methyl cyclohexane radical. Such an amine may be reacted with a polyisocyanate and optionally with other known additives to form a polyurethane plastic or foam.
摘要:
Polyether-based urethane-group-containing polyamines containing polymers and/or copolymers of unsaturated monomers and, optionally, urea and/or biuret and/or allophanate groups are produced by (a) reacting an NCO-prepolymer in aqueous alkaline solution at 0.degree. to 40.degree. C. to form a carbamate; (b) converting this carbamate to an amine by adding an ion exchanger to the reaction mixture; and (c) separating the polyamine from the reaction mixture. The NCO-prepolymers used as starting materials are prepolymers of (i) polyalkylene ether polyols having a molecular weight of from 1,000 to 10,000 containing from 1 to 60 wt. % of graft (co)polymers of unsaturated monomers; and (ii) excess molar quantities of organic polyisocyanate; and optionally, (iii) a low molecular weight chain-extending agent. The product polyamines have a molecular weight of from 1,000 to 10,000 and contain from 0.65 to 59.3 wt. % graft (co)polymer and from 0.11 to 2.9 wt. % terminal NH.sub.2 groups attached to the ethers by urethane groups in the polyisocyanate. The product polyamines are particularly useful in the production of polyurethanes.
摘要:
A compound having a terminal isocyanate group is hydrolyzed to produce a polyamine having a urethane and/or a urea and/or a biuret group. More particularly, a carbamate is made by mixing an isocyanate prepolymer having urethane and/or urea and/or biuret groups present with aqueous base solutions at a temperature of from 0.degree. to 0.degree. C. and in quantities such that the equivalent ratio of hydroxyl to isocyanate groups is between from 0,3:1 to .gtoreq.1,01 to 1. The carbamate is then treated with an acid ion exchanger to form an amine. The amine is then removed from any other material which may be present. A preferred polyamine thus-produced corresponds to the general formula: ##STR1## in which each R radical may represent a divalent straight or branched- chain aliphatic radical; a divalent cycloaliphatic radical; a 4,4'- and/or a 2,4'-dicyclohexylmethane radical; or a 2,4- and/or 2,6-methyl cyclohexane radical. Such an amine may be reacted with a polyisocyanate and optionally with other known additives to form a polyurethane plastic or foam.
摘要:
A polymer precursor containing an oxazolin-2-one ring is made by reacting (a) an amino-reactive group containing compound having at least two groups capable of entering into an addition or condensation reaction with primary or secondary aromatically-bound amino groups with (b) an aromatic amine having at least one primary or secondary aromatically-bound amino group and at least one condensed oxazolin-2-one ring. The reactants are used in quantities such that for each aromatically bound primary or secondary amino group there are from 0.95 to 5 groups present in the amino-reactive group containing compound which are capable of reacting with the amino group. These polymer precursors may be used to produce high molecular weight polymers useful in the production of solid molded products, adhesives, foam plastics and coatings.
摘要:
The instant invention is directed to a process for the production of a light fast, transparent polyurethane elastomer comprising reacting:(A) from 90 to 50% by weight, based on the polyurethane solids content, of a compound having a molecular weight of from 400 to 10,000 which has at least two Zerewitinoff active hydrogen atoms;(B) from 50 to 10% by weight, based on the polyurethane solids content, of an aliphatic and/or alicyclic polyisocyanate; and(C) from 0 to 20% by weight, based on the polyurethane solids content, of a chain-lengthening agent having a molecular weight of from 60 to 400; in the presence of:(D) catalysts for the isocyanate polyaddition reaction, the improvement wherein said catalysts, component (D), is a catalyst combination of:(a) an alkali metal hydroxide and/or alkaline earth metal hydroxide; and(b) an organometallic compound selected from the group consisting of the acetyl acetonate of iron, C.sub.1 -C.sub.8 alcoholates, phenolates, enolates and/or acetyl acetonates of metals of the 4th main group or sulfur-containing compounds of metals of the 4th main group, in which compounds the sulfur is directly attached to the metal atom.
摘要:
The invention relates to polyisocyanates corresponding to the following general formula: ##STR1## wherein X represents a radical of the type obtained by removing the more reactive isocyanate group from an organic diisocyanate containing isocyanate groups of different reactivity; andY represents a chlorine, bromine, C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 alkoxy, C.sub.6 -C.sub.10 aryl, C.sub.6 -C.sub.10 aroxy radical or a radical corresponding to the general formula: --NH--CO--NH--X.