摘要:
The present invention relates to a process for preparing self-crosslinking polyurethane dispersions by I) reacting a1) polyisocyanates with a2) at least one hydroxyl component having an average OH functionality of ≧2 and a number average molecular weight of 62 to 2500 g/mol, wherein the hydroxyl component contains at least one acid-functional compound containing at least one isocyanate-reactive group, to form an NCO-functional and optionally OH-functional prepolymer, II) then reacting the NCO-functional and optionally OH-functional prepolymer with a3) a hydroxyl component having an average OH functionality of >1 and a4) optionally another polyisocyanate component, which may be the same as or different from a1), to form an OH-functional and NCO-free polyurethane, III) adding a blocked polyisocyanate either before, during or after the reaction of steps I) and II), or forming a blocked polyisocyanate in situ from a polyisocyanate and a blocking agent after the reaction of step II) has taken place, IV) neutralizing the acid groups of the resulting composition by adding a5) a neutralizing agent, and V) dispersing the resulting composition in water. The present invention also relates to the dispersions prepared by the present invention and to their use in coating, adhesive and sealant compositions.
摘要:
The present invention relates to aqueous, self-crosslinking polyurethane dispersions containing in the same polyurethane molecule structural units I) and II) wherein R is the radical obtained by removing the isocyanate groups from an aliphatic, cycloaliphatic, araliphatic or aromatic polyisocyanate, R′ is an alkyl radical, X is a carboxylic acid (COOH) or carboxylate (COO−) radical, Y is NH2, NHR″ or OH, and R″ is an alkyl radical. The present invention also relates to a process for preparing these aqueous, self-crosslinking polyurethane dispersions and to their use in aqueous one-component baking systems and in aqueous coating, varnishes or adhesive compositions.
摘要:
The present invention relates to silicon-free polyisocyanates or polyurethanes which contain at least one structural unit of formula (1) wherein m is 0 to 8, n is 0 to 8, m+n is≧2, R1 and R2 independently of one another are each hydrogen or an OH-free, optionally substituted C1 to C8 alkyl or cycloalkyl radical, R4 is the radical obtained by removing the carboxylic acid groups from a difunctional aliphatic dicarboxylic acid having at least two carbon atoms, a cycloaliphatic dicarboxylic acid having at least 6 carbon atoms or an aromatic dicarboxylic acid having at least 6 carbon atoms, and R3 is the same as R1 or R2 or corresponds to formula (2) wherein R1 and R2 are as defined above and R6 is an alkyl or aryl radical obtained by removing an isocyanate group from a di- or polyisocyanate having optionally blocked NCO groups. The present invention also relates to a process for preparing these silicon-free polyisocyanates or polyurethanes.
摘要:
Blocked polyisocyanates and one-component stoving systems containing these blocked polyisocyanates, and the preparation thereof and their use for the preparation of lacquers, paints, adhesives and elastomers. The blocked polyisocyanates are derived from polyisocyanates reacted with secondary amines and cationic, anionic and/or nonionic hydrophilizing agents such that they are incorporated into the polyisocyanate at a ratio of from 20:1 to 1:1, wherein the blocking agents correspond to the formula R1–R4 can be identical or different and independently of one another denote hydrogen, C1–C6-alkyl or C3–C6-cycloalkyl, R5 denotes C1–C10-alkyl, C3–C10-cycloalkyl, and B represents wherein R6–R8 can be identical or different and independently of one another denote C1–C6-alkyl and/or C1–C6-cycloalkyl, R9 denotes hydrogen or C3–C6-alkyl or C3–C6-cycloalkyl.
摘要:
A process for preparing self-crosslinking polyurethane polymers including i) reacting an aromatic isocyanate component (A) or a mixture of aromatic, aliphatic and/or cycloaliphatic isocyanate component having an isocyanate group functionality of greater than or equal to 2 with an at least difunctional polyol component (B1) with an average molecular weight of from 62 to 2500, which includes at least one acid-functional compound (C), to give a prepolymer containing isocyanate groups or containing hydroxyl groups, ii) adding one or more polyol components (B2) having an OH functionality of greater than or equal to 1, and optionally, an isocyanate component (A′), which may be identical to or different from (A), iii) mixing the resulting NCO-functional product with a blocking agent (D), and iv) adding a polyol component (B3). Self-crosslinking polyurethane polymers prepared as described above can be used in paint, varnish or adhesive compositions.
摘要:
The present invention relates to solvent-free, NCO prepolymers having a residual IPDI monomer content of less than 2.0 wt. %, an NCO content of 2.0 to 5.0 wt. % and a viscosity of 5000 to 20,000 mPa·s, wherein the NCO prepolymers are the reaction products of i) 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and ii) one or more polyethers prepared by the DMC catalyst process and having an OH-functionality of 1.80 to 2.00 at an NCO/OH equivalent ratio of 1.5:1 to 2.2:1. The present invention also relates to a process for preparing these solvent-free, NCO prepolymers and to polyurethane coating, sealant, adhesive and/or embedding compositions containing the solvent-free, NCO prepolymers as a binder and/or binder component.