A liquid crystalline polyurethane elastomer is produced by reacting an isocyanate component, a high-molecular-weight polyol component and a mesogenic diol represented by formula (1), and having a crosslinking site that is introduced by a tri-functional or higher isocyanate in the isocyanate component and/or a high-molecular-weight polyol having a number average molecular weight of 400 or more and less than 7000 and having three or more hydroxy groups, in the high-molecular-weight polyol component, wherein the melting point of a mesogenic unit does not exist in a temperature range lying between the glass transition temperature (Tg) and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) of the polyurethane elastomer, and a liquid crystal is developed at a temperature between the Tg and the Ti. (In the formula, X represents an alkylene group having 3 to 20 carbon atoms; and Y represents a single bond, —N═N—, —CO—, —CO—O— or —CH═N—). ##STR00001##

A liquid crystalline polyurethane elastomer is produced by reacting an isocyanate component, a high-molecular-weight polyol component and a mesogenic diol represented by formula (1), and having a crosslinking site that is introduced by a tri-functional or higher isocyanate in the isocyanate component and/or a high-molecular-weight polyol having a number average molecular weight of 400 or more and less than 7000 and having three or more hydroxy groups, in the high-molecular-weight polyol component, wherein the melting point of a mesogenic unit does not exist in a temperature range lying between the glass transition temperature (Tg) and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) of the polyurethane elastomer, and a liquid crystal is developed at a temperature between the Tg and the Ti. (In the formula, X represents an alkylene group having 3 to 20 carbon atoms; and Y represents a single bond, —N═N—, —CO—, —CO—O— or —CH═N—). ##STR00001##

The present invention provides low polyphenols (such as bisphenol A) tougheners for epoxy adhesives. The tougheners, and adhesives comprising the tougheners exhibit enhanced viscosity stability, e.g., compared to tougheners prepared from higher amounts of bisphenol A (and epoxy adhesives comprising them).

An aspect of the present invention relates to a composition, which is a composition for a magnetic recording medium and comprises an isocyanate compound in the form of an adduct of a polyhydroxyl compound having one or more aromatic carbon rings and three or more hydroxyl groups per molecule with a polyisocyanate having two or more isocyanate groups per molecule.

The present invention provides a polyaspartic composition comprising a reaction product of a polyamine and a Michael addition receptor reacted in the presence of a catalyst comprising a phenolic compound, with the proviso that the phenolic compound is not a phenol which is substituted with tert-butyl groups in both ortho positions to the oxygen. Suitable phenolic compounds include phenols, phenolic aldehydes, alkylphenols, benzenediols, cashew nut oil, and combinations thereof. Coatings, adhesives, sealants, composites, castings, and films comprising a polyurea composition may be made by reacting a polyisocyanate with the inventive polyaspartic composition. In particular, floor coatings made with the inventive polyaspartic composition have an elongated work time and a short walk-on time compared to current floor coatings.

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

The present invention provides polyurethanes including a reaction product of components including: (a) an isocyanate functional urethane prepolymer comprising a reaction product of components including: (i) about 1 equivalent of at least one polyisocyanate; and (ii) about 0.1 to about 0.5 equivalents of at least one diol having 2 to 18 carbon atoms; and (b) about 0.05 to about 0.9 equivalents of at least one branched polyol having 4 to 18 carbon atoms and at least 3 hydroxyl groups; and (c) up to about 0.9 equivalents of at least one polyol different from branched polyol (b) and having 2 to 18 carbon atoms, wherein the reaction product components are essentially free of polyester polyol and polyether polyol; compositions, coatings and articles made therefrom and methods of making the same.

A shoe press belt includes a polyurethane in which a reinforcement base member is embedded, the polyurethane being in one piece with the reinforcement base member. The polyurethane constituting at least an outer circumferential surface of the shoe press belt includes, as an urethane prepolymer component, an aliphatic polycarbonatediol component and an aromatic diisocyanate component, and includes, as a curing agent component, an aliphatic diol component having a carbon number of less than or equal to 6 and an aromatic diol component having two hydroxyethoxy groups. A content of the aromatic diol component with respect to the aliphatic diol component and the aromatic diol component is more than or equal to 10 mass % and less than or equal to 50 mass %. Accordingly, there is provided a shoe press belt suppressed in generation and development of a crack.

A shoe press belt includes a polyurethane in which a reinforcement base member is embedded, the polyurethane being in one piece with the reinforcement base member. The polyurethane constituting at least an outer circumferential surface of the shoe press belt includes, as an urethane prepolymer component, an aliphatic polycarbonatediol component and an aromatic diisocyanate component, and includes, as a curing agent component, an aliphatic diol component having a carbon number of less than or equal to 6 and an aromatic diol component having two hydroxyethoxy groups. A content of the aromatic diol component with respect to the aliphatic diol component and the aromatic diol component is more than or equal to 10 mass % and less than or equal to 50 mass %. Accordingly, there is provided a shoe press belt suppressed in generation and development of a crack.

The present invention relates to an adhesive, a preparation method and application thereof, particularly the application for bonding glass fiber composites, and a bonded article obtained by using the adhesive. The adhesive comprises: a polyisocyanate having an isocyanate functionality of not less than 2; an epoxy-modified polyether polyol; a hydroxyl-containing acrylate; a redox catalyst; a silane coupling agent; optionally a polyol containing bisphenol A structure; and optionally a polymer polyol different from the epoxy-modified polyether polyol. The adhesive according to the present invention has the advantages of being insensitive to moisture, good bonding properties and a long pot life.