The embodiments relate to a polythiol composition for a plastic optical lens and a polythiourethane-based plastic optical lens prepared therefrom. In the embodiments, a first polythiol compound having an ester group and a mercapto group only as a hydrogen-bondable functional group and a second polythiol compound having an ester group and a hydrogen-bondable functional group other than a mercapto group are used in an appropriate amount. Thus, it is possible to control the viscosity of a polymerizable composition at the initial stage of polymerization at a low temperature of 5 to 15 C. and to stabilize the rate of increase in the viscosity of the composition and the reaction rate thereof, thereby preventing the generation of striae, bubbles, and the like. Further, various plastic lenses such as eyeglass lenses, camera lenses, and the like having excellent appearance characteristics (without striae and bubbles) and excellent optical characteristics can be obtained from the composition.

A method for producing an organic mercapto compound or an intermediate thereof according to the present invention has a reaction step of reacting an alcohol compound including a sulfur atom with a thioamide compound having a structure in which an organic group is bonded to at least one bonding hand of a thioamide group, under acidic conditions.

An embodiment relates to a polymerizable composition for a plastic lens. The polymerizable composition for a plastic lens according to the embodiment comprises a nonhalogenated tin-based catalyst and a diketone compound as a low-temperature reaction rate controlling agent. Accordingly, the polymerizable composition has a more stable pot life so that the polymerization rate can be appropriately controlled, thereby improving the reactivity and the workability, and that the generation of bubbles are prevented, thereby improving the transparency of the resin.

A thrust reverser cascade for an aircraft nacelle includes a plurality of blades having a first and a second surface, the blades being connected to members connected to attachment flanges for attaching the thrust reverser cascade to the nacelle. At least one of the surfaces of the blades is covered with at least one layer of fibers, each layer including a plurality of fiber pieces which are pre-impregnated with resin. The fiber pieces are superimposed on one another, positioned parallel to the aerodynamic surface of the blade and oriented in different directions.

A water dispersible sulfo-polyamide is configured as a filament for use as an extrudable support material in the additive manufacture of a part comprising a non water dispersible polymer. The water dispersible sulfo-polyamide is a reaction product of a sulfo monomer, the water dispersible sulfo-polymer being dispersible in water resulting in separation of the water dispersible polymer from the part comprising the non water dispersible polymer.

The present invention can provide a method for producing a cured product of an episulfide-based resin, the method having: (A) a step for obtaining a composition for a resin by mixing compound (a), compound (b) and a polymerization catalyst; (B) a step for pouring the composition for a resin into a mold; and (C) a step in which, by increasing the temperature of a heating medium, the composition for a resin is polymerized in the heating medium that contains a liquid having a thermal conductivity of 0.2 W/m.Math.K or higher, or in a shower of the heating medium. The maximum temperature of the heating medium in step (C) is 55 to 110 C. (a) A compound which has two episulfide groups per molecule and which is represented by formula (1): ##STR00001##
wherein m represents an integer from 0 to 4 and n represents an integer from 0 to 2 (b) A compound having one or more thiol groups per molecule.

The present disclosure relates to the use of occluding fluids, such as a high-density fluid (a z-fluid) or a low-density fluid (an a-fluid), to displace resin within a vat during 3D printing. Further, an a-fluid may act as a protective boundary for a 3D printing resin wherein the a-fluid sits on top of the printing resin. Another embodiment of the disclosure provides a process of assessing which regions of a computer-aided design (CAD) model take advantage of a buoying force supplied by the occluding fluid, such that fewer support structures are needed for printing a final CAD model compared to printing the CAD model without the occluding fluid.

An object of the present invention is to provide a method for producing a crosslinked polyarylene sulfide (PAS) that reduces a difference in melt viscosity among lots and has excellent quality stability. Further specifically, the present invention provides a method for producing a crosslinked PAS including steps of compression-molding an uncrosslinked PAS in a powder form to obtain a compression-molded material, measuring a porosity of the compression-molded material, grinding the compression-molded product having a specific range of porosity to obtain a pulverized material, granulating the pulverized material to obtain a granulated material, and oxidatively crosslinking the granulated material obtained in the preceding step. Also provided are a method for producing a composition containing the crosslinked PAS, and a method for producing a molded article by melt-molding the composition.

A method for producing an organic mercapto compound or an intermediate thereof according to the present invention has a reaction step of reacting an alcohol compound including a sulfur atom with a thioamide compound having a structure in which an organic group is bonded to at least one bonding hand of a thioamide group, under acidic conditions.

A composite pipe comprises a polyetheretherketone innermost pipe around which a reinforcing overwrap is arranged. A protective sheath surrounds the overwrap. Such a composite pipe may be made by selecting a polyetheretherketone pipe having an outer region having a crystallinity of less than 25%; overlaying the selected pipe with overwrap; and subjecting the combination to heat, thereby causing the crystallinity of the outer region of the polyetheretherketone pipe to increase. The method reduces the risk of pipe failure.