In a structural polyurethane adhesive, a polyisocyanate component contains a first prepolymer component containing a first isocyanate group-terminated urethane prepolymer which is a reaction product of a first material polyisocyanate consisting of an aromatic polyisocyanate, and a first material polyol containing a macropolyol; and a second prepolymer component containing a second isocyanate group-terminated urethane prepolymer which is a reaction product of a second material polyisocyanate consisting of an araliphatic polyisocyanate and/or an aliphatic polyisocyanate, and a second material polyol containing a polyether polyol having a number average molecular weight of 160 or more and 4800 or less. A ratio of the second prepolymer component with respect to the total amount of the first prepolymer component and the second prepolymer component is 2% by mass or more and 35% by mass or less.

In a structural polyurethane adhesive, a polyisocyanate component contains a first prepolymer component containing a first isocyanate group-terminated urethane prepolymer which is a reaction product of a first material polyisocyanate consisting of an aromatic polyisocyanate, and a first material polyol containing a macropolyol; and a second prepolymer component containing a second isocyanate group-terminated urethane prepolymer which is a reaction product of a second material polyisocyanate consisting of an araliphatic polyisocyanate and/or an aliphatic polyisocyanate, and a second material polyol containing a polyether polyol having a number average molecular weight of 160 or more and 4800 or less. A ratio of the second prepolymer component with respect to the total amount of the first prepolymer component and the second prepolymer component is 2% by mass or more and 35% by mass or less.

An adhesive includes: a urethane prepolymer (A) obtained by reacting a polyol (a) with a polyisocyanate (b) under such conditions that the molar ratio of NCO/OH is 0.5-0.9 and having a molecular-weight dispersion degree [(weight-average molecular weight (Mw))/(number-average molecular weight (Mn)); hereinafter referred to also as Mw/Mn] of 4-12; a polyfunctional polyol (B), and an isocyanate curing agent (C).

An adhesive includes: a urethane prepolymer (A) obtained by reacting a polyol (a) with a polyisocyanate (b) under such conditions that the molar ratio of NCO/OH is 0.5-0.9 and having a molecular-weight dispersion degree [(weight-average molecular weight (Mw))/(number-average molecular weight (Mn)); hereinafter referred to also as Mw/Mn] of 4-12; a polyfunctional polyol (B), and an isocyanate curing agent (C).

A multicomponent adhesive composition comprises a composition A and a composition B. Composition A comprises at least one silyl polymer comprising at least one hydrolyzable alkoxysilane group and at least one tackifying resin. Composition B comprises at least one catalyst and at least one compound C chosen from a compound C1 with a number-average molecular mass ranging from 300 g/mol to 500 000 g/mol; and a compound C2 with a vapor pressure at 20° C. of greater than or equal to 0.08 kPa; and mixtures thereof. The composition A:composition B mass ratio ranges from 99.98:0.02 to 60:40. The total content of catalyst ranges from 0.01% to 10% relative to the total weight of said adhesive composition.

The present invention relates to isocyanate-terminated prepolymers based on polyoxymethylene-polyoxyalkylene block copolymers, to a process for their preparation, and to the use of these isocyanate-terminated prepolymers as isocyanate components in 1- and 2-component systems for coatings, adhesives and sealants.

The present invention relates to isocyanate-terminated prepolymers based on polyoxymethylene-polyoxyalkylene block copolymers, to a process for their preparation, and to the use of these isocyanate-terminated prepolymers as isocyanate components in 1- and 2-component systems for coatings, adhesives and sealants.

The present invention relates to an aqueous polyurethane dispersion, a method for the preparation thereof, a product comprising the same, and use thereof for a coating composition, an impregnating composition, an adhesive or a sealant. The aqueous polyurethane dispersion comprises a polyurethane obtained by reacting a system comprising the following components: A1) at least one polyisocyanate having an isocyanate functionality of not less than 2; A2) at least two different polytetramethylene ether glycols A2a) and A2b), the A2a) having a number average molecular weight of not more than 1500 g/mol, the A2b) having a number average molecular weight of more than 1500 g/mol; and A3) at least one anionic or potentially anionic hydrophilic agent having a number average molecular weight of 32 g/mol to 400 g/mol and containing hydroxyl and carboxyl functions; B) at least one amino-functional anionic or potentially anionic hydrophilic agent; and C) at least one amino-functional compound having a number average molecular weight of 32 g/mol to 400 g/mol and containing no hydrophilic group; wherein the ratio of the number average molecular weight of the A2a) to the number average molecular weight of the A2b) is 1:9 to less than 1:1, and the weight of the A3) amounts to 20% to 70% of the weight of the hydrophilic agents of the system, wherein the hydrophilic agents of the system are components A3 and B.

An adhesive tape including an adhesive layer is provided. The adhesive layer has a biobased content of 50% or more by mass. The adhesive layer contains a reaction product of a urethane resin (A) and a cross-linking agent (B). The urethane resin (A) contains at least a structural unit derived from a biobased polyether polyol and a structural unit derived from an aromatic polyisocyanate. The adhesive layer has a gel fraction of 10% or more by mass and 80% or less by mass and a stress of less than 50 N/cm.sup.2 at 100% strain in a stress-strain curve.

An adhesive tape including an adhesive layer is provided. The adhesive layer has a biobased content of 50% or more by mass. The adhesive layer contains a reaction product of a urethane resin (A) and a cross-linking agent (B). The urethane resin (A) contains at least a structural unit derived from a biobased polyether polyol and a structural unit derived from an aromatic polyisocyanate. The adhesive layer has a gel fraction of 10% or more by mass and 80% or less by mass and a stress of less than 50 N/cm.sup.2 at 100% strain in a stress-strain curve.