Provided is a multilayer vessel excellent in gas barrier performance and transparency and its application. The multilayer vessel contains a layer (X) that contains at least one type of polyolefin resin as the major ingredient; and a layer (Y) that contains a polyamide resin (A) as the major ingredient, the polyamide resin (A) being composed of a structural unit derived from diamine, and a structural unit derived from dicarboxylic acid, 70 mol % or more of the structural unit derived from diamine being derived from metaxylylenediamine, meanwhile 30 to 60 mol % of the structural unit derived from dicarboxylic acid being derived from straight chain aliphatic ,-dicarboxylic acid having 4 to 20 carbon atoms, and 70 to 40 mol % being derived from isophthalic acid.

Provided is a multilayer vessel excellent in gas barrier performance and transparency and its application. The multilayer vessel contains a layer (X) that contains at least one type of polyolefin resin as the major ingredient; and a layer (Y) that contains a polyamide resin (A) as the major ingredient, the polyamide resin (A) being composed of a structural unit derived from diamine, and a structural unit derived from dicarboxylic acid, 70 mol % or more of the structural unit derived from diamine being derived from metaxylylenediamine, meanwhile 30 to 60 mol % of the structural unit derived from dicarboxylic acid being derived from straight chain aliphatic ,-dicarboxylic acid having 4 to 20 carbon atoms, and 70 to 40 mol % being derived from isophthalic acid.

A customizable polyamide polymer, in particular Nylon 66, Nylon 6, and copolyamides, having a high molecular weight, excellent color, and low gel content is disclosed. In particular, disclosed is a polymer having a relative viscosity greater than 50 as measured in a 90% strength formic acid solution; consistent viscosity with a standard deviation of less than 1; a gel content no greater than 50 ppm as measured by insolubles larger than 10 micron; an optical defect content of less than 2,000 parts per million (ppm) as measured by optical control system (OCS). The polymer can be made into monofilaments or a multifilament yarn.

Also disclosed is a process of producing the polymer using in-line vacuum finishing technology in the absence of steam or other gases in the second, or post condensation, step of the polymer process.

The present invention relates to a polymer powder for the manufacture of articles by 3D printing, in particular by sintering, comprising a thermoplastic polymer, antioxidants, and a particular metal oxide, metal hydroxide and/or hydrotalcite, having improved thermal stability, improved recyclability and improved consistency of mechanical properties of the sintered parts.

The invention also relates to a process for preparing this powder and to the use thereof in a process for manufacturing by sintering, and to the articles manufactured from said powder.

The present invention relates to a polymer powder for the manufacture of articles by 3D printing, in particular by sintering, comprising a thermoplastic polymer, antioxidants, and a particular metal oxide, metal hydroxide and/or hydrotalcite, having improved thermal stability, improved recyclability and improved consistency of mechanical properties of the sintered parts.

The invention also relates to a process for preparing this powder and to the use thereof in a process for manufacturing by sintering, and to the articles manufactured from said powder.

A continuous solid-state polymerization device according to the present invention comprises: a feeder for injecting a prepolymer continuously; a transverse reactor connected to the feeder via a first connector to receive the prepolymer from the feeder and to perform solid-state polymerization, the reactor itself rotating; and a chamber connected to the transverse reactor via a second connector to receive a polymer, which has been discharged from the transverse reactor, and solid-state polymerization of which has been completed, and to discharge the polymer, wherein the transverse reactor has a demolding coating film formed on the inner wall thereof, and the feeder, the transverse reactor and the chamber are in a vacuum state. The continuous solid-state polymerization device can prevent formation of an interval, in which the prepolymer stagnates, and can perform solid-state polymerization continuously in a vacuum state without using inert gas.

A continuous solid-state polymerization device according to the present invention comprises: a feeder for injecting a prepolymer continuously; a transverse reactor connected to the feeder via a first connector to receive the prepolymer from the feeder and to perform solid-state polymerization, the reactor itself rotating; and a chamber connected to the transverse reactor via a second connector to receive a polymer, which has been discharged from the transverse reactor, and solid-state polymerization of which has been completed, and to discharge the polymer, wherein the transverse reactor has a demolding coating film formed on the inner wall thereof, and the feeder, the transverse reactor and the chamber are in a vacuum state. The continuous solid-state polymerization device can prevent formation of an interval, in which the prepolymer stagnates, and can perform solid-state polymerization continuously in a vacuum state without using inert gas.

The continuous solid-state polymerization device of the present invention comprises: a feeder for continuously introducing a prepolymer; a horizontal reactor which is connected via a first connecting part to the feeder and receives the prepolymer from the feeder so as to subject same to solid-state polymerization, wherein the reactor itself is rotated; a stirring device which comprises a stirring shaft rotating inside the horizontal reactor, in the direction opposite to that of the rotational axis of the horizontal reactor, and comprises stirring blades joined vertically to the stirring shaft; and a chamber which is connected via a second connecting part to the horizontal reactor and, once the solid-state polymerization has been completed, receives the resulting polymer discharged from the horizontal reactor, and, here, the feeder, the horizontal reactor and the chamber are in a vacuum state. The continuous solid-state polymerization device prevents the formation of prepolymer stagnation zones, and allows solid-state polymerization to take place continuously in the vacuum state without any inert gas.

The continuous solid-state polymerization device of the present invention comprises: a feeder for continuously introducing a prepolymer; a horizontal reactor which is connected via a first connecting part to the feeder and receives the prepolymer from the feeder so as to subject same to solid-state polymerization, wherein the reactor itself is rotated; a stirring device which comprises a stirring shaft rotating inside the horizontal reactor, in the direction opposite to that of the rotational axis of the horizontal reactor, and comprises stirring blades joined vertically to the stirring shaft; and a chamber which is connected via a second connecting part to the horizontal reactor and, once the solid-state polymerization has been completed, receives the resulting polymer discharged from the horizontal reactor, and, here, the feeder, the horizontal reactor and the chamber are in a vacuum state. The continuous solid-state polymerization device prevents the formation of prepolymer stagnation zones, and allows solid-state polymerization to take place continuously in the vacuum state without any inert gas.

The present invention provides a process for producing polyamides, which comprises a) providing a monomer composition comprising at least one lactam or at least one aminocarbonitrile and/or oligomers of these monomers, b) reacting the monomer composition provided in step a) in a hydrolytic polymerization at elevated temperature in the presence of water to obtain a reaction product comprising polyamide, water, unconverted monomers and oligomers, c) the reaction product obtained in step b) being fed into at least one kneader (3) and subjected to a postpolymerization, d) optionally forming the reaction product obtained in step c) to obtain polyamide particles, e) optionally treating the reaction product obtained in step c) or the polyamide particles obtained in step d) with at least one extractant.