A polyurethane composition includes first and second components, wherein the first component contains between 30% and 99% by weight of a polyol mixture including 100 parts by weight of at least one hydrophobic polyol, 10 to 75 parts by weight of at least one hydrophilic polyol, 0 to 25 parts by weight of at least one diol having two hydroxyl groups linked via a C2 to C9 carbon chain; and also at least one compound having at least one thiol group; and the second component includes at least one polyisocyanate, wherein one of the two components additionally includes at least one metal catalyst for the reaction of hydroxyl groups and isocyanate groups that is able to form thio complexes and the molar ratio of all the thiol groups in the at least one compound to all metal atoms in the at least one metal catalyst is between 1:1 and 250:1.

The present invention provides an optical composition from which an optical article having reduced poor appearance such as cloudiness and optical strain during lens base material production can be obtained, and when a photochromic compound is added, a photochromic cured body having excellent photochromism and mechanical strength can also be formed, and a polyrotaxane used therefor. The polyrotaxane has a composite molecular structure formed of an axle molecule and a plurality of cyclic molecules clathrating the axle molecule, satisfying at least one of (X) and (Y). (X): A side chain having a secondary or tertiary hydroxyl group is introduced into at least part of the cyclic molecule of the polyrotaxane. (Y): A side chain having a group represented by -A (A is an organic group, and contains at least one hydroxyl group) is introduced into at least part of the cyclic molecule of the polyrotaxane, and a pKa of the hydroxyl group of the compound represented by H-A is 6 or more and less than 14.

The invention relates to a non-aqueous coating composition comprising a. a polyisocyanate, b. a polyol having an average functionality of more than 3 hydroxyl groups per molecule, c. a metal based curing catalyst for the addition reaction of isocyanate groups and hydroxyl groups, and d. a mercapto carboxylic acid,
wherein the coating composition does not contain a carboxylic acid wherein the carbonyl group of the carboxylic acid is in conjugation with a π-electron system.

The dental restorative material of the present invention is a dental restorative material that contains a resin matrix and an inorganic filler in an amount of 25 to 1,000 parts by mass per 100 parts by mass of the resin matrix, and in the dental restorative material, the resin matrix contains a polyurethane resin, and the inorganic filler has an average particle diameter of 0.001 to 100 μm. According to the present invention, a dental restorative material that has a high bending strength and a high surface hardness, and is excellent in transparency and cutting workability, and a resin material for dental cutting work containing the same can be provided.

According to an embodiment, the pH of a diisocyanate composition and a diamine hydrochloride composition used in the preparation of an optical lens is adjusted to a specific range, whereby it is possible to enhance not only the yield and purity of the diisocyanate composition but also the optical characteristics of the final optical lens by suppressing the striae and cloudiness. Specifically, according to the process of the embodiment, the amount of an aqueous hydrochloric acid solution introduced to the reaction may be adjusted to control the pH of the diisocyanate composition to a desired range, thereby enhancing the yield and purity. Accordingly, the process for preparing a diisocyanate composition according to the embodiment can be applied to the preparation of a plastic optical lens of high quality.

Polythiourethane polymer networks that can be processed and/or recycled are provided. Also provided are methods of forming the polythiourethane polymer networks using excess thiol and/or a dual catalyst system and methods for reprocessing and recycling the polyurethane polymer networks. The polythiourethane polymer networks are based on thiourethane dynamic chemistry.

Polythiourethane polymer networks that can be processed and/or recycled are provided. Also provided are methods of forming the polythiourethane polymer networks using excess thiol and/or a dual catalyst system and methods for reprocessing and recycling the polyurethane polymer networks. The polythiourethane polymer networks are based on thiourethane dynamic chemistry.

A lacquer composition is provided, comprising 20%-79.9% by weight, based on the total weight of the composition, of a thiol compound having two or more thiol groups, 20%-79.9% by weight, based on the total weight of the composition, of a compound having two or more carbon-carbon double bonds and 0.1%-10% by weight, based on the total weight of the composition, of a separating agent having an alkyl radical having 4-20 carbon atoms, where the alkyl radical is unsubstituted or fluorine-substituted and the alkyl radical is bonded to a functional group. Also provided are the use of this lacquer composition as a protective lacquer on an optical surface of an optical element in the production of the optical element, and an optical element comprising the protective lacquer.

A resist underlayer composition and a method of forming patterns using a resist underlayer composition, the resist underlayer composition including a polymer, the polymer including a structural unit that is a reaction product of an isocyanurate compound, the isocyanurate compound having at least one thiol group thereon, and a solvent.

Provided is a method for producing a resin lens, comprising: A) mixing a polyisocyanate, a modified isocyanate, a catalyst and a release agent, and performing vacuum defoaming at 0˜30° C. for 10˜90 min to obtain a material a; B) mixing the material a with a sulfur-containing compound, and performing vacuum defoaming at 15˜20° C. for 20˜120 min to obtain mixed monomers; and C) completing casting of the mixed monomers, and curing to obtain a resin lens. The present disclosure uses polyisocyanate and a modified isocyanate at the same time to prepare a resin lens with higher glass transition temperature and higher surface hardness without producing bank mark and edge fogging. The present disclosure further provides a method for producing modified isocyanate. The obtained modified isocyanate used with polyisocyanate further improves the glass transition temperature and surface hardness of the resin lens without producing bank mark and edge fogging.