Low primary amine (LPA) polyaspartic esters are provided which comprise a reaction product of an aliphatic diamine and an excess of a Michael addition receptor optionally, in the presence of a C.sub.1-C.sub.10 alcohol, wherein the low primary amine (LPA) polyaspartic ester has a monoaspartate content of less than 10%. The low primary amine (LPA) polyaspartic esters of the invention may find use in slow reactivity polyurea systems and react with polyisocyanates to produce polyurea coatings, adhesives, sealants, films, composites, castings, and paints.

Low primary amine (LPA) polyaspartic esters are provided which comprise a reaction product of an aliphatic diamine and an excess of a Michael addition receptor optionally, in the presence of a C.sub.1-C.sub.10 alcohol, wherein the low primary amine (LPA) polyaspartic ester has a monoaspartate content of less than 10%. The low primary amine (LPA) polyaspartic esters of the invention may find use in slow reactivity polyurea systems and react with polyisocyanates to produce polyurea coatings, adhesives, sealants, films, composites, castings, and paints.

A multilayer tube having excellent low temperature impact resistance, breakage pressure strength at high temperature, flexibility, dimensional stability, and elution resistance of low molecular weight substances and ion components. The multilayer tube has a layer containing an aliphatic polyamide composition having a predetermined range of a bending elastic modulus; a layer containing a modified polyolefin has a melting point over a predetermined temperature, and the aliphatic polyamide composition contains an aliphatic polyamide having a predetermined range of a methylene group/amide group number ratio, an elastomer polymer having a constituent unit derived from a carboxyl group and/or acid anhydride group-containing unsaturated compound, and a plasticizer having a certain structure if necessary; and the thickness of the layer containing the aliphatic polyamide composition is a specific ratio or more of the total wall thickness of the tube.

Aqueous base- or acid-stabilized emulsions are provided for use on a pavement surface, and for use in an aqueous priming base emulsion that is used for priming a pavement surface. Any of the emulsions can be applied to a pavement surface to form a primed pavement surface, and then cured so that the pavement is available for use in preparing a pavement.

By having a coating layer, this composite semipermeable membrane has fouling resistance easily maintainable before and after contact with acid, and enables stable operation over a long period of time. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer arranged on the separation function layer, wherein the separation function layer contains a crosslinked aromatic polyamide which is a polycondensate of polyfunctional aromatic amines and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer having the structure (I) in the description.

Medium and high molecular weight long chain aliphatic nylons and methods of making the same. A method of making medium and high molecular weight nylons is described, which not only produces consistent products, but products with enhanced properties such as impact resistance and chemical resistance.

Medium and high molecular weight long chain aliphatic nylons and methods of making the same. A method of making medium and high molecular weight nylons is described, which not only produces consistent products, but products with enhanced properties such as impact resistance and chemical resistance.

By having a coating layer, this composite semipermeable membrane has fouling resistance easily maintainable before and after contact with acid, and enables stable operation over a long period of time. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer arranged on the separation function layer, wherein the separation function layer contains a crosslinked aromatic polyamide which is a polycondensate of polyfunctional aromatic amines and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer having the structure (I) in the description.

A novel membrane is provided in which the permeate flow rate is not prone to decrease even when the membrane is used to process seawater with high salt concentration and high heavy metal ion concentration. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer coating the separation function layer, wherein the separation function layer contains a crosslinked polymer amide which is a condensate of polyfunctional aromatic amine and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer including a polyether moiety and a carbonic acid polymer moiety.

A flexible tube for an endoscope has a flexible tube substrate that is flexible and tubular and a resin layer (A) covering the flexible tube substrate. The resin layer (A) includes a thermoplastic resin (a) including at least one of a polyatnide resin, a polyurethane resin, a polyester resin, a polystyrene resin, or an acrylic resin and having a tensile strength at 10% elongation of 10 Pa or more and a hindered amine compound (b) having a molecular weight of 500 or more. Also provided are an endoscopic medical device including the flexible tube for an endoscope and a resin composition suitable for forming the resin layer of the flexible tube for an endoscope.