A carbodiimide-based aqueous resin crosslinking agent excellent in the storage stability in the coexistence of an aqueous resin, comprising a polycarbodiimide (A) having substituents derived from hydrophilic organic compounds at both terminals thereof, at least one of the substituents being a substituent derived from a hydrophilic organic compound having a molecular weight of 340 or more, and a polycarbodiimide (B) having substituents derived from organic compounds having a molecular weight of 300 or less at both terminals thereof, wherein the mass ratio [(B)/(A)] of the polycarbodiimide (B) to the polycarbodiimide (A) is from 20/80 to 95/5.

The present invention relates to reactive mixtures and processes for forming flexible polyurethane foams more in particular low-density flexible polyurethane foams with mainly open cells and low air flow resistivities, said reactive mixture being characterized as a reactive mixture avoiding the use of water as blowing agent and at least one carbodiimide forming catalyst beside at least one polyurethane and/or polyisocyanurate forming catalyst and said processes being characterized as having a low reaction exotherm during foaming thereby reducing the risk of scorching during production.

Described herein is a thermosetting resin composition, obtained from the reaction of at least: a polycarbodiimide (i), where the number of carbodiimide groups per molecule is in the range of from 1 to 10; a mixture of crystalline and amorphous polyols (ii), where the molar ratio of carbodiimide groups in the polycarbodiimide according to (i) to hydroxyl groups in the mixture according to (ii) is in the range of from 1:2 to 2:1 and where at least 25 weight-% of the mixture according to (ii) consists of at least one crystalline polyesterol, based on the overall weight of the mixture being 100 weight-%. Also described herein is a method of using the thermosetting resin composition as an adhesive, as well as processes for preparation of adhesives, an element including an adhesive layer on at least one substrate, and an adhesive film, obtained from one of the processes.

The invention relates to a method for modifying isocyanates, wherein at least one organic monomer isocyanate having an NCO functionality >1 is oligomerised in the presence of at least one catalyst, said method being characterised in that the catalyst comprises at least one specific compound having an NPN sequence selected from compounds of formula I (formula I), and/or from compounds of formula II (formula II) where HX represents an acid with a pKa value 2, X.sup. represents the anion of an acid with a pKa value 2, and n represents an integer or fractional number between 0 and 20, wherein Y represents R.sub.12(R.sub.13)N and/or one or more substituents of the structure of formula III (formula III) and wherein R.sub.1 to R.sub.19 independently represent identical or different substituents selected from C.sub.1-C.sub.20 alkyl-, C.sub.1-C.sub.20 cycloalkyl- and C.sub.6-C.sub.20 aryl groups, or wherein R.sub.1 and R.sub.2, R.sub.3 and R.sub.4, R.sub.5 and R.sub.6, R.sub.7 and R.sub.8, R.sub.9 and R.sub.10, R.sub.12 and R.sub.13, R.sub.14 and R.sub.15, R.sub.16 and R.sub.17, R.sub.18 and R.sub.19 independently represent identical or different substituents selected from C.sub.1-C.sub.20 alkylene-, C.sub.1-C.sub.20 cycloalkylene-, C.sub.6-C.sub.20 arylene groups, and can form a 3- to 12-membered ring with the N atom joined to the P atom. The invention also relates to the use of a catalyst of this type.

The invention relates to novel carbodiimides, to processes for the production thereof and to the use thereof as a stabilizer in ester-based polyols, in polyethylene terephthalate (PET), in polybutylene terephthalate (PBT), in polytrimethylene terephthalate (PTT), in copolyesters, in thermoplastic polyester elastomers (TPE E), in ethylene vinyl acetate (EVA), in polylactic acid (PLA) and/or in PLA derivatives, in polybutylene adipate-terephthalates (PBAT), in polybutylene succinates (PBS), in polyhydroxyalkanoates (PHA), in blends, in triglycerides, in thermoplastic polyurethanes, in polyurethane elastomers, in PU adhesives, in PU casting resins, for PU coatings or in PU foams.

A process for the preparation of polycarbodiimides which also contain aziridine functions and which are not genotoxic. These aziridine-functional polycarbodiimides may be used as crosslinking agent.

A polycarbodiimide composition is a reaction product of polyisocyanate having a primary isocyanate group and alcohols, wherein in an infrared absorption spectrum, the intensity ratio (IR.sub.CI/IR.sub.UI+U) of absorbance IR.sub.CI at or near 2120 cm.sup.1 due to stretching vibration of the carbodiimide group relative to absorbance IR.sub.UI+U at or near 1720 cm.sup.1 due to stretching vibration of the uretonimine group and urethane group is 1.5 or more and 4.5 or less.

The present invention provides a polyisocyanate composition wherein the composition is obtained from an aliphatic diisocyanate unit including 1,6-diisocyanatohexane, and has an isocyanurate group, a uretdione group, a uretonimine group, and an iminooxadiazinedione group, and the molar ratio of the uretonimine group to the isocyanurate group is 0.0010 to 0.0050, and the molar ratio of the iminooxadiazinedione group to the isocyanurate group is 0.00050 to 0.30.

A polycarbodiimide composition is a reaction product of polyisocyanate having a primary isocyanate group and alcohols, wherein in an infrared absorption spectrum, the intensity ratio (IR.sub.CI/IR.sub.UI+U) of absorbance IR.sub.CI at or near 2120 cm.sup.1 due to stretching vibration of the carbodiimide group relative to absorbance IR.sub.UI+U at or near 1720 cm.sup.1 due to stretching vibration of the uretonimine group and urethane group is 1.5 or more and 4.5 or less.

A composition for forming a polyiso-urea includes a capped polycarbodiimide and a polyol. The capped polycarbodiimide comprises the reaction product of a diisocyanate and a monoisocyanate in the presence of an oxygen scavenger and a carbodiimidization catalyst and in the absence of solvent, has 0.25 wt. % or less of free isocyanate groups, and is a liquid at 25 C. A polyiso-urea comprises the reaction product of the capped polycarbodiimide and the polyol.