231 results about "Allophane" patented technology

The present invention relates to a process for preparing low-viscosity, allophanate-containing and NCO-free polyurethane prepolymers curable by actinic radiation, and to the products obtainable by this process. The prepolymers have residual monomer contents of less than 0.5% by weight and an NCO content of less than 1% by weight, and are prepared by a process in which A) diisocyanates, B) hydroxy-functional compounds containing groups which react with ethylenically unsaturated compounds on exposure to actinic radiation, and C) polyester, polyether or polycarbonate polyols having a functionality of at least 1.9 and a number-average molecular weight (M_n) of at least 1000 g/mol, D) optionally in the presence of a catalyst, are reacted to form NCO-group-containing prepolymers having radiation-curing groups, which are subsequently reacted E) optionally after addition of monofunctional isocyanates in the presence F) of an allophanatization catalyst to give allophanate-containing prepolymers, the ratio of NCO groups of the compounds from A) to the OH groups of the compounds from B) and C) being 1.45:1.0 to 1.1:1.0 and the ratio of the OH groups from B) to the OH groups from C) being 8.0:1 to 1.5:1.

The present invention relates to a process for lowering the viscosity of compositions containing compounds having urethane groups, in which all or some of the urethane groups contained therein are reacted with monoisocyanates to form allophanate groups. The present invention also relates to compounds having allophanate groups and compositions containing such compounds, wherein at least 10 mole % of the allophanate groups contained therein correspond to formula I)

wherein R is an alkyl, aralkyl or aryl radical which has up to 20 carbon atoms and optionally contains heteroatoms and wherein these radicals can also have, in addition to the NCO group present as part of the allophanate group, other functional groups which are neither isocyanate groups nor functional groups derived from isocyanate groups.

This invention discloses a pseudoboehmite and its preparation method. This pseudoboehmite is prepared by following steps: a) at acidity condition that can make aluminum precipitate, precipitate aluminum of aluminum compound water solution, separate, and get a kind of amorphous alumina hydrate; b) mix amorphous hydrated aluminum oxide with water and at least one kind of water-soluble alkali, slurry, stabilize at 20deg-90deg for 0.2-6 hours, wherein dosage of above alkali make serumal pH be 6-11. Compared with existing technique, pseudoboehmite prepared by this invention can get aluminum oxide of bore distributing localized by calcining.

The invention discloses high-hardness scratch-resistant double-component waterborne polyurethane woodwork varnish and a preparation method thereof. The varnish consists of double components, i.e., a primer and a curing agent, wherein the primer consists of hydroxyl polyacrylate dispersion resin, dispersant, nano-scale silicon dioxide glass powder, a scratch-resistant wax auxiliary agent, an organic bismuth/zinc composite catalyst, an antifoaming agent, a wetting agent, water and an additive, wherein the sum of the weight percentages of the A components is 100 percent; the curing agent consists of propylene glycol ethyl ether acetate and allophanate modified HDI (Hexamethylene Diisocyanate) tripolymer; the sum of the weight percentages of the B components is 100 percent; and the A components and the B components are mixed according to the equivalent molar ratio of n-NCO:n-OH as 1.38:1.62. The varnish has the advantages of high hardness, shortened surface drying time and hard drying time, long activation period, superior performance, environmental friendliness of the product and high operability.

The invention relates to polyisocyanates containing allophanate groups and silane groups, to a process for preparing them and to their use as a starting component in the production of polyurethane polymers, more particularly as a crosslinker component in polyurethane paints and coatings.

The invention discloses a quick demoulding water-blown low-density integral skin polyurethane-urea composition which comprises a polyalcohol mixture component A and a modified isocyanate component B, wherein the component A is a polyalcohol mixture which comprises polyether glycol, polymer polyol, a cross linking agent, organic diamine, a divalent alcohol chain extender, a nonvolatile catalyst and/or a reactive catalyst, water and color paste; the component B is allophanate modified isocyanate containing 22-31 wt percent of NCO and is formed by polymerizing methyl diphenylene diisocyanate (MDI) and polyalcohol with molecular weight of 62-3000. The component A and the component B according to a weight ratio of 100:40-100 are polymerized into integral skin polyurethane-urea with integral intensity of 260-400 kg/m, and the integral skin polyurethane-urea can be demoulded within 60 seconds.

Polymers which comprise polymer chains of terpolymer type which are constituted by poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) of PEO-PPO-PEO form, which are modified at their termini by groups which can essentially be other chains of PEO-PPO-PEO, acid segments, amine groups or PEOs, these chains being linked to the terpolymer chains via chemical bridges which are constituted by urethane bridges, urea bridges, allophanate bridges and biuret bridges, and which comprise more than 80% by weight of said PEO-PPO-PEO. Thermoreversible physical gels of high viscosification index, which contain these polymers, and their uses. Preparation of these polymers and of these gels.

The invention provides a soft polyurethane foam and its manufacture method capable of solving the above problem, characterized in that: the mixing solution of an organic polyisocyanate (A), a polyhydric alcohol (B), a catalyst (C), a foaming agent (D) and a foam stabilizer (E) reacts, foams and cures to obtain the soft polyurethane foam, wherein the organic polyisocyanate (A) uses the mixture of an organic polyisocyanate combination A1 modified by an allophanate composed of a monohydric alcohol and aliphatic and/or alicyclic ring diisocyanate and an organic polyisocyanate combination A2 modified by the allophanate composed of an alcohol with more than two hydroxyl groups and the aliphatic and/or alicyclic ring diisocyanate.

A self-repairing polyurethane resin material is produced by reaction of a polyisocyanate compound consisting of aliphatic polyisocyanate and/or araliphatic polyisocyanate with an active hydrogen group-containing compound, used for producing polyurethane resin having self-repairing properties, has an isocyanate group at its molecular terminal, contains an allophanate group and an isocyanate trimer, and the mole ratio of the allophanate group relative to the isocyanate trimer is 0.1 to 20.

The present invention provides a polyisocyanates composition which expresses high curing characteristic, drying characteristic and crosslinking degree, and also has excellent performance in coating appearance such as smoothness of the coating surface, a coating composition comprising the same, and a coating method. The polyisocyanates composition is formed by more than one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate and more than one diol. In the polyisocyanates composition, the mole ratio of allophanate group/(isocyanurate group + allophanate group) is 0.2-0.9, and the mole ratio of allophanate group/(allophanate group + urethane group) is 0.6-1.0.

The present invention relates to two-component coating systems for producing flexible coatings. The coating systems comprise polyurethane prepolymers with allophanate structures and also amino-functional polyaspartic esters as curing agents.

The present invention is directed to a polyisocyanate mixture i) having an NCO content of 5 to 35% by weight and a monomeric diisocyanate content of less than 3% by weight, and prepared from a polyisocyanate adduct, ii) containing allophanate groups in an amount such that there are more equivalents of allophanate groups than urethane groups and such that the polyisocyanate mixture remains stable and homogeneous in storage for 1 month at 25° C. and iii) containing siloxane groups (calculated as SiO, MW 44) in an amount of 0.002 to 50% by weight, wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein the siloxane groups are incorporated by reacting an isocyanate group with a compound containing one or more hydroxyl groups directly attached to a carbon atom and one or more siloxane groups. The present invention is also directed to a process for the production of this polyisocyanate mixture and to its use, optionally in blocked form, as an isocyanate component in one- or two-component coating compositions.

The invention discloses a full diphenyl-methane-diisocyanate (MDI)-base high-resilience polyurethane foam which comprises a polyatomic alcohol mixture component A and a modified MDI component B, wherein the component A is a polyatomic alcohol mixture, the component B is the mixture of carbamate modified MDI and allophanate modified MDI, and the weight ratio of the carbamate modified MDI to the allophanate modified MDI is 1:99-95:5. The high-resilience polyurethane foam prepared by polymerizing the component A and the component B in weight ratio of 100:50-100:80 has a density of 38-45kg/m<3>, and can be used for manufacturing car seats.

Process for preparing binders including reacting A) one or more NCO-functional compounds containing uretdione groups with B) one or more compounds containing groups capable of participating in polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation, and contain isocyanate-reactive groups, followed by C) reaction with one or more hydroxyl-containing compounds other than B), wherein at least one of these compounds has an OH functionality of ≧2, D) in the presence of one or more compounds containing phenoxide groups, as catalysts, and E) optionally auxiliaries and additives, where the reaction with compounds of component C) proceeds at least proportionally with the formation of allophanate groups and where and including binders containing allophanate groups and groups capable of participating in a polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation, and optionally also contain NCO-reactive groups. The binders are used in coating compositions used to coat substrates.

The invention relates to a process for preparing binders which contain 1) allophanate groups, 2) groups that react with ethylenically unsaturated compounds with polymerization on exposure to actinic radiation (radiation-curing groups) and 3) optionally NCO-reactive groups, by reacting at temperatures ≦130° C. A) one or more NCO-functional compounds containing uretdione groups with B) one or more compounds that contain isocyanate-reactive groups and groups that react with ethylenically unsaturated compounds with polymerization on exposure to actinic radiation (radiation-curing groups), and then C) with one or more saturated, hydroxyl-containing compounds other than B), at least one of these compounds having an OH functionality of ≧2, in the presence of D) a catalyst containing one or more ammonium salts or phosphonium salts of aliphatic or cycloaliphatic carboxylic acids, the reaction with compounds C) taking place at least proportionally with the formation of allophanate groups. The present invention also relates to the binders obtained by the process of the invention.

The present invention relates to modified alkoxysilane-functional polyurethanes containing allophanate and/or biuret groups, wherein at least 10 mol % of the allophanate and/or biuret groups are formed from a monoisocyanate of the formula R-NCO, wherein R is an optionally heteroatom-containing alkyl, aralkyl or aryl radical having up to 20 carbon atoms, provided that these radicals do not contain any other reactive groups with the exception of the NCO group that is part of the allophanate structure and any alkoxysilyl groups present. The present invention also relates to a process for preparing alkoxysilane-functional prepolymers by A) reacting some or all of the urethane groups and/or urea groups of alkoxysilane-functional polyurethane prepolymers with monoisocyanates of the formula, R-NCO to form allophanate groups and/or biuret groups, or B) reacting some or all urethane groups and/or urea groups of alkoxysilyl-free polyurethane prepolymers with monoisocyanates of the formula R-NCO to form allophanate groups and/or biuret groups, the radical R having at least one alkoxysilyl group. The present invention further relates to sealants, adhesives, primers and coatings based on the polyurethane prepolymers of the invention.

Disclosed is a polyisocyanate composition containing a polyisocyanate, which is obtained by reacting hexamethylene diisocyanate and an aliphatic monoalcohol having 11-20 carbon atoms, and a low-polarity organic solvent having an aniline point of 10-70 DEG C or a low-polarity organic solvent having a mixed aniline point of 5-50 DEG C. The polyisocyanate contains an allophanate group, an isocyanurate group and a urethane group in a molecule, and the molar ratio between the allophanate group and the isocyanurate group, namely allophanate group/isocyanurate group, is from 70/30 to 30/70. The composition is soluble in a low-polarity organic solvent, and has excellent compatibility with a polyol compound. Consequently, the composition can provide a coating film having excellent physical properties such as surface hardness.

The polyisocyanate cured product according to the present invention has an isocyanurate structure, which comprises at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate, as a unit structure, the polyisocyanate cured product having an allophanate group, and the molar ratio of the isocyanurate group to the allophanate group (isocyanurate group/allophanate group) is 99/1 to 20/80.

A polyisocyanate composition, coating composition and method of manufacturing coating material are provided. A polyisocyanate composition exhibiting high dryness, and further excellent in moisture stability and compatibility with a polyol, a coating composition containing the same, and a coating method thereof are provided. A polyisocyanate composition comprises a polyisocyanate composition obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates and one or more diols; in the polyisocyanate composition, the molar ratio of the ureido group / (ureido + isocyanurate group) is from 0.0001 to 0.1, and the allophanate group / (isocyanurate group + urea Carboxylate group) is in the range of 0.2 to 0.9.