This invention relates to an in-situ formed polyether polyol blend having an overall functionality of 2 to 3 and an overall hydroxyl number of 40 to 220 mg KOH/g. A process for preparing these in-situ formed polyether polyol blends is also disclosed. These in-situ formed polyether polyol blends are suitable for a process of preparing viscoelastic flexible polyurethane foams.

A crosslinking agent composition for water-compatible resins which comprises a hydrophobic crosslinking agent, a water-soluble organic compound, one or more oily media selected from among hydrocarbon-based solvents and ketone-based solvents having a solubility parameter of 9.0 (cal/cm.sup.−3).sup.1/2 or less, and an aqueous medium. The crosslinking agent composition can improve the storage stability of a water-compatible resin composition. The water-compatible resin composition which contains this crosslinking agent composition can give cured objects satisfactory in terms of water resistance and solvent resistance and is suitable also for use in wet-on-wet coating.

A method of producing a polyurethane or polyisocyanurate foam is provided which involves the use of a specific combination of hydrofluoroolefin blowing agents and cell nucleators. The resulting foams have excellent long term thermal insulating performance and have reduced thickness in comparison to conventional thermal insulating boards. The rigid polyurethane and polyisocyanurate boards may be used to insulate refrigeration bodies, such as those employed in vehicles comprising refrigeration units, and cold storage containers.

A trimerization catalyst composition suitable for making a polyisocyanurate comprising (insulation) foam, said composition comprising at least a trimerization catalyst compound selected from one or more organic salts from alkoxides wherein said organic salt is selected from alkali metal, earth alkali metal, a transition metal such as Ti and/or quaternary ammonium organic salts.

The invention relates to a method for producing isocyanurates and isocyanurate-containing polyurethanes, comprising the step of reacting an isocyanate in the presence of a catalyst.

The present invention provides a stabilising composition, comprising: a) a first phenolic antioxidant comprising one or more phenolic compounds having the structure of formula (I): ##STR00001##  wherein R.sub.1 is a linear or branched alkyl group having from 12 to 20 carbon atoms; and b) one or more second phenolic antioxidants independently selected from:  a mono-hydroxybenzene having lower steric hindrance than the first phenolic antioxidant;  a di-hydroxybenzene; and/or  a tri-hydroxybenzene.

Provided is a water blocking material prepared by reacting and foaming a starting material composition that contains a polyol, a polyisocyanate, a catalyst, a foaming agent, a foam stabilizer and a crosslinking agent, in which the polyol contains a dimer acid polyol, the content of the dimer acid polyol in the starting material composition is 85% by mass or more of the entire polyol, the polyisocyanate contains a diphenylmethane diisocyanate, the content of the diphenylmethane diisocyanate in the starting material composition is 70 to 85% by mass of the entire polyisocyanate, and the foam stabilizer contains a reactive silicone. The water blocking material is excellent in heat resistance and water blocking performance and is further excellent in flexibility.

Polythiourethane polymer networks that can be processed and/or recycled are provided. Also provided are methods of forming the polythiourethane polymer networks using excess thiol and/or a dual catalyst system and methods for reprocessing and recycling the polyurethane polymer networks. The polythiourethane polymer networks are based on thiourethane dynamic chemistry.

A method of making an isocyanurate polymer is disclosed. An isocyanate including at least one of an aromatic isocyanate and an aliphatic isocyanate is provided. A trimerization catalyst including at least one of an amine catalyst, an organometallic compound, and an imidazole compound is provided. A reaction mixture that is substantially free of reactive hydrogen is formed by mixing less than about twenty percent by total weight of said reaction mixture of an epoxide with said isocyanate. The trimerization catalyst is mixed with the reaction mixture. The reaction mixture is cured to produce a polymer composition including a reaction product of two or more isocyanates.

A method for preparing rigid polyurethane (PUR) foams or rigid polyisocyanurate (PIR) foams in which method the rigid PUR or PIR foam is prepared by reacting a composition (C) comprising: at least one isocyanate-reactive component (B1) having functional groups selected from hydroxyl, amine and thiol groups; at least one isocyanate component (A1) having an average functionality of less than 2.70; and at least one blowing agent [blowing agent (BA), herein after]; with the proviso that the overall average functionality [F.sub.n,avg(A), herein after] of all isocyanate components present in the composition (C) is less than 2.70; wherein the composition (C) is characterized by an isocyanate index X, wherein the rigid PUR or PIR foams are produced by depositing the composition (C) between two gas-tight facing sheets and wherein the rigid PUR or PIR foam is characterized by a difference Δλ between the initial thermal conductivity value λ.sub.ini and the aged thermal conductivity value λ.sub.aged of said rigid PUR or PIR foam wherein: when X≤200 then Δλ<1.35; and when X>200 then Δλ<[6.49−(4.46*F.sub.n,avg(A))−(0.02348*X)+(0.492*F.sub.n,avg(A)*F.sub.n,avg(A))+(0.01343*F.sub.n,avg(A)*X)+0.3].