Abstract: The present invention provides a reaction mixture comprising a blend of a first isocyanate-based uretdione-containing resin and a second isocyanate-based uretdione-containing resin, a neutralized polyol and a tertiary amine catalyst, and optionally, an additive package selected from the group consisting of flow control additives, pigments (colorants), wetting agents, and solvents, wherein the first isocyanate and the second isocyanate are different. The first isocyanate-based uretdione-containing resin and the second isocyanate-based uretdione-containing resin may be cold blended or hot blended. Coatings, adhesives, castings, composites, and sealants made from hot blended formulations exhibit superior performance over those made from cold blended formulations.

Abstract: The present invention provides a reaction mixture comprising a hot blend of a first isocyanate-based uretdione resin and a second isocyanate-based uretdione resin, a neutralized polyol and a tertiary amine catalyst, and optionally, an additive package selected from the group consisting of flow control additives, pigments (colorants), wetting agents, and solvents, wherein the first isocyanate and the second isocyanate are different. The isocyanate-based uretdiones that have been hot blended together produce coatings, adhesives, castings, composites, and sealants, which exhibit better performance properties (such as microhardness) than those coatings, adhesives, castings, composites, and sealants produced from the constituent isocyanate-based uretdiones alone.

Abstract: Partially crosslinked polyurethane polymers comprising diisocyanates and aliphatic hydrocarbon soft segments with a short-chain diol chain extender and a multifunctional amine and/or alcohol crosslinker to provide a polyurethane polymer with useful properties for the production of medical implant devices such as heart valves, are described. The polymers have an unexpected linear elastic region in a range from 5-100% and preferably between 10-35%. In some embodiments the polyurethanes are a thermally convertible gel formulation which may be converted to a liquid formulation by extended heating to render the polymer suitable for solvent processing techniques such as casting, spraying, spinning, etc. The invention also provides for living hinge polyurethane polymers which are thermally modifiable from a gel to a liquid and reaction injection moulded (RIM) polyurethanes with an enhanced flex life.

Abstract: The present invention provides a system comprising an allophanate composition comprising a neutralized polyol, a polyuretdione resin, a tertiary amine catalyst, an additive package, and a reducer; and a neutralized basecoat comprising an inorganic salt and a pigment. The present invention further provides a method of making an allophanate system comprising combining a neutralized polyol with a polyuretdione resin in the presence of a tertiary amine catalyst, an additive package, and a reducer to produce an allophanate composition, and contacting the allophanate composition with a neutralized basecoat comprising an inorganic salt and a pigment. The system may be used to make coatings, adhesives, castings, composites, and sealants in which clear-coating on neutralized pigmented basecoats is much improved in comparison to coating on non-neutralized basecoats.

Abstract: The present invention provides a system comprising an allophanate composition comprising a neutralized polyol, a polyuretdione resin, a tertiary amine catalyst, an additive package, and a reducer and a neutralized basecoat comprising an acid scavenger and a pigment. The resulting allophanate system may be used to make coatings, adhesives, castings, composites, and sealants in which clear-coating on neutralized pigmented basecoats is much improved in comparison to non-neutralized basecoats.

Abstract: The present invention provides an electrophotographic photosensitive member sequentially including: a support; a photosensitive layer; and a protection layer formed on the support, wherein the protection layer has a triarylamine structure and a specific cyclic structure, and a specific A-value obtained by measurement using total reflection Fourier transform infrared spectroscopy is 0.010 or more and 0.050 or less.

Abstract: The present invention provides a reaction mixture comprising a polyuretdione resin, a neutralized polyol, an acid-blocked tertiary amine catalyst, and optionally, an additive package selected from the group consisting of flow control additives, and wetting agents, and solvents, wherein the acid has a pKa of greater than 4.82. Compositions made from the reaction mixture of the present invention may be catalyzed at temperatures from room temperature to 130° C. and are particularly applicable in or as coatings, adhesives, castings, composites, and sealants with good performance and extended pot-life.

Abstract: Flow-regulating luminal endoprosthesis (30) comprising a first sections and a second section characterised in that at an end (35) of the endoprosthesis, the second section is turned over on the inside or the outside of the first section in such a way as to form an endoprosthesis (30) comprising two substantially coaxial sections (31, 32) and a turnover part (33) that joins the two sections (31, 32), with the turnover part (33) being located at an end (35) of the endoprosthesis (30) and method pour manufacturing the endoprosthesis (30).

Abstract: 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 mercapto groups only as a hydrogen-bondable functional group and a second polythiol compound having mercapto groups as a hydrogen-bondable functional group and a hydrogen-bondable functional group other than a mercapto group are used in an appropriate amount. Thus, not only is it 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, but also the change in the viscosity at a low temperature is low, thereby preventing the generation of striae, bubbles, and the like.

Abstract: The present invention relates to processes for producing polymeric carbodiimides by addition of cesium salts and to polymeric carbodiimides produced by this process and to the use thereof as a hydrolysis inhibitor, especially in polyurethane (PU)-based systems, preferably thermoplastic TPU, PU adhesives, PU casting resins, PU elastomers or PU foams.

Abstract: The invention relates to a two-component polyurethane composition containing i) 10 to 80 wt. % of at least one polyol with an average molecular weight of 200 g/mol to 3000 g/mol, ii) 5 to 60 wt. % of at least one aromatic polyisocyanate, and iii) 0 to 15 wt. % of an additive. The composition has an NCO:OH ratio of 2:1 to 1:2, and the composition has a viscosity of 20 to 3000 mPas (EN ISO 2555, Brookfield viscometer, 25° C.) and displays a phase incompatibility after the mixing process. The functionality of the polyol mixture is greater than 2.3.

Abstract: Provided are: a powdered material for slush molding; and a manufacturing process therefor. The powdered material is less odorous, exhibits excellent powder fluidity, and does not suffer from troubles resulting from the sliding-down or agglomeration of a pigment even when the resin particles have been pigmented on the surfaces thereof. Thus, the powdered material ensures high productivity. The powdered material is a powdered polyurethane urea resin composition which comprises (D) a polyurethane urea resin that has a total content of bimolecular condensate of acetone, bimolecular condensate of methyl ethyl ketone, and bimolecular condensate of methyl isobutyl ketone of 1,000 ppm or less and (N) an additive, wherein the polyurethane urea resin (D) takes the form of thermoplastic polyurethane urea resin particles (P) that have a volume-mean particle diameter of 20 to 500 ?m and that have protrusions and recesses on the surfaces.

Abstract: The invention relates to the use of carbodiimide-containing compositions for controlling pot life in the production of polyurethane (PU)-based systems, preferably PU elastomers, PU adhesives, PU casting resins or PU foams.

Abstract: Disclosed are processes for the preparation of rosin diols accomplished by the reaction of a rosin acid with a glycerine carbonate in the presence of a catalyst, and subsequently where the rosin diol can be reacted with a diacid to generate an amorphous polyester resin.

Abstract: A light guide plate that uses a resin film as a material for the light guide plate, that has a reflecting or scattering pattern formed by printing, and that guides a light propagating in the film to exit and emerge from the front surface thereof. The light guide plate is thinner and highly flexible, and has high reliability and durability. A base material of the light guide plate is formed from a thermosetting polyurethane sheet with a thickness of 0.4 mm or less. When a dot pattern is formed by ink-jetting, a white UV curable ink, for which the thermosetting polyurethane exhibits a swellability such that the thermosetting polyurethane increases by 10% or more in weight as a result of being soaked in the ink for one hour at a room temperature, is used as the ink.

Abstract: An object of the present invention is to provide a golf ball with an improved controllability by enhancing a dry spin rate and wet spin rate in a so-called distance type golf ball. The present invention provides a golf ball comprising a constituting member that is formed from a polyurethane composition containing, as a resin component, a polyurethane elastomer using 1,4-bis(isocyanatomethyl)cyclohexane as a polyisocyanate component, wherein the polyurethane composition has a shear loss modulus G? of more than 5.03×106 Pa and 1.17×108 Pa or less when measured in a shear mode using a dynamic viscoelasticity measuring apparatus at the conditions of the temperature of 0° C., and the oscillation frequency of 10 Hz.

Abstract: The present invention relates to novel methods for preparing a polythiol compound for use in an optical material and polymerizable compositions including a polythiol compound prepared by the methods. According to the methods, a polythiol compound with uniform color, high purity and high quality can be prepared at reduced cost. The polymerizable compositions can be used to manufacture clear, transparent optical lenses with good heat resistance and excellent optical properties.

Abstract: Embodiments of the invention include insulated units and methods of producing the insulating units. The insulating units include a first surface, a structural seal disposed on at least portions of the first surface, and a second surface disposed on the structural seal. The structural seal includes the reaction product of at least one first isocyanate, at least one isocyanate reactive side, and at least one adhesion promoter including a reaction product of at least one secondary aminoalkoxy silane and at least one second isocyanate.

Abstract: To provide a water/oil repellent agent and a water/oil repellent composition which is capable of providing an article surface with a sufficient water/oil repellency, while placing little burden on the environment. One comprising a reaction product obtained by reacting a fluoromonool having a polyfluoroalkyl moiety having at most 6 carbon atoms as an alcohol, an alkane monool having at least 18 carbon atoms, and MDI or a polymeric MD, and by treating an article with such a water/oil repellent agent, a sufficient water/oil repellency can be imparted, while placing little burden on the environment. By treating the above-mentioned article with the water/oil repellent composition of the present invention, a high quality water/oil repellency can be imparted to the article.

Abstract: Polyurea systems comprising: (a) an amino-functional aspartic ester of the general formula (I) wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH2)n, R1 and R2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2; and (b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting: (b1) an aliphatic isocyante; and (b2) a polyol component having a number average molecular weight of ?400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof; processes for making the same; postoperative adhesions barriers prepared therewith and dispensing systems for such polyurea systems.

Abstract: The present invention relates to a composition comprising 10 to less than 50 wt.-% of at least one oligomeric polyisocyanate a-1) based on hexamethylene diisocyanate and more than 50 to 90 wt.-% of at least one polyisocyanate a-2) based on isophorone diisocyanate, comprising monomeric isophorone diisocyanate and at least one oligomeric isophorone diisocyanate, and an isocyanate-reactive component selected from the group consisting of polyester polyol, polyether polyol and mixtures thereof. It has been shown that the above mentioned mixture of the specific isocyanate group containing components improves the thermal and mechanical properties of a cured composition. Thus prepared molded articles are particularly suitable for the preparation of spectacle lenses, inter alia due to these properties.

Abstract: Embodiments include oxazolidone ring containing adducts obtainable by combining an aliphatic epoxy compound, an aromatic epoxy compound, and a diisocyanate. Embodiments further include a curable powder coating composition including a resin component and a hardener component, where the resin component includes the oxazolidone ring containing adduct.

Abstract: The present invention provides poly(ureaurethane)s including a reaction product of components comprising: (a) at least one isocyanate functional ureaurethane prepolymer comprising the reaction product of: (1) at least one isocyanate functional urethane prepolymer comprising the reaction product of: (i) a first amount of at least one polyisocyanate selected from the group consisting of polyisocyanate trimers and branched polyisocyanates, the polyisocyanate having at least three isocyanate functional groups; and (ii) a first amount of at least one aliphatic polyol; and (2) water, to form an isocyanate functional ureaurethane prepolymer; and (b) a second amount of at least one polyisocyanate and a second amount of at least one aliphatic polyol; compositions, coatings and articles made therefrom and methods of making the same.

Abstract: A photosensitive composition includes (A) a polyurethane obtained by reacting a diol component including a compound represented by the following Formula (I) with a polyisocyanate component; and (B) a photosensitive component. In Formula (I), A represents a single bond, or a divalent linking group including an atom selected from the group consisting of a carbon atom, a hydrogen atom, and an oxygen atoms; B represents a monovalent organic group; each of R1 to R5 independently represents a hydrogen atom or an alkyl group; m represents an integer from 0 to 3; n represents an integer from 0 to 3; and m+n is not zero.

Abstract: A polishing pad compound and a polishing pad, the polishing pad compound including a pre-polymer; and a hardener, wherein the pre-polymer includes about 45 wt % to about 50 wt % of a polyol, about 5 wt % to about 25 wt % of a hardness regulator, and a balance of an isocyanate.

Abstract: The present invention is a production method of a polycarbonate resin, including a step of performing melt polycondensation by continuously feeding a dihydroxy compound (A) having a predetermined moiety in a part of the structure and a carbonic acid diester each in a liquid state to a reactor, wherein the residence time from liquefaction of the dihydroxy compound to its feeding to a reactor is from 0.1 to 10 hours.

Abstract: Disclosed is a granular polyurethane resin composition containing a thermoplastic polyurethane resin which contains a hard segment obtained by a reaction between a polyisocyanate and a chain extender. The polyisocyanate contains isocyanate groups of 1,4-bis(isocyanatomethyl)cyclohexane in an amount of not less than 50% by more relative to the total mole number of isocyanate groups.

Abstract: The present invention relates to a stable pyrithione salt polyol dispersion containing a pyrithione salt(s) in particulate form, a polyol and a stabilizer such as a rheological additive. The dispersion can be incorporated into existing polyurethane formulations without additional formula adjustment. Polyurethane foams produced from the composition containing pyrithione salt polyol dispersion of the present invention have more open cell structures, than those produced with a typical commercially available pyrithione salt thus providing a soft comfortable feeling.

Abstract: A plastic lens having excellent weather resistance, formed by polymerization of a composition containing a polyisocyanate compound having an aromatic ring and a polythiol compound is provided. The plastic lens is formed by polymerization of a composition that contains 100 parts by mass in total of (A) a polyisocyanate compound containing a polyisocyanate compound having an aromatic ring and (B) a polythiol compound, from 0.5 to 5.0 parts by mass of (C) a benzophenone compound having a hydroxyl group on at least the ortho position, and from 0.5 to 5.0 parts by mass of (D) a phenol compound.

Abstract: The present invention relates to a polycarbonate resin composition, comprising: a polycarbonate resin containing a structural unit derived from a dihydroxy compound having a moiety represented by the following formula (1) [provided that a case where the moiety represented by formula (1) is a moiety constituting —CH2—O—H is excluded]; and an elastomer composed of a core?shell structure, wherein a core layer of the elastomer is composed of a butadiene-styrene copolymer, and a polycarbonate resin molded article obtained by molding the polycarbonate resin composition: CH2—O??(1).

Abstract: A partial-discharge-resistant insulating varnish has a polyamide-imide enamel varnish and an organo-silica sol that are dispersed in a solvent. The solvent has 50 to 100% by weight of ?-butyrolactone. An insulated wire has a conductor, and a partial-discharge-resistant insulation coating film formed on the surface of the conductor. The partial-discharge-resistant insulation coating film is made of the partial-discharge-resistant insulating varnish.

Abstract: The present invention is a production method of a polycarbonate resin, including a step of performing melt polycondensation by continuously feeding a dihydroxy compound (A) having a predetermined moiety in a part of the structure and a carbonic acid diester each in a liquid state to a reactor, wherein the residence time from liquefaction of the dihydroxy compound to its feeding to a reactor is from 0.1 to 10 hours.

Abstract: A urethane adhesive composition includes a first liquid and a second liquid, the first liquid containing a prepolymer obtained by reacting a polyisocyanate and a high-molecular-weight polyol (I), and at least one filler selected from talc and calcium carbonate, and containing 20 parts by mass or more of talc, 0 to 40 parts by mass of calcium carbonate, and 10 parts by mass or more of zeolite based on 100 parts by mass of the polyisocyanate, the high-molecular-weight polyol (I), and the prepolymer in total, the second liquid containing a high-molecular-weight polyol (II) and a low-molecular-weight polyol, the ratio of the number of moles of hydroxyl groups derived from the low-molecular-weight polyol to the total number of moles of hydroxyl groups derived from the high-molecular-weight polyol (I) and the high-molecular-weight polyol (II) being four or more.

Abstract: The invention relates to a coating agent composition comprising an isocyanate-group-containing prepolymer obtained by reacting a polyol comprising a polyoxyalkylene polyol having 2-4 hydroxyl groups on average, an oxyethylene group content of 85-100% by mass based on all oxyalkylene groups (100% by mass), and an arithmetic-average molecular weight of 800-2,500 with an alicyclic isocyanate and/or an aliphatic isocyanate in the presence of an organic acid bismuth salt catalyst, the isocyanate(s) being used in such an amount as to result in an isocyanate index of 150-300. The invention can provide a coating agent composition which forms a coating film or film having moisture permeability, excellent in mechanical properties and yellowing resistance, having laundering durability and resistance to sweat deterioration, and containing no organotin compounds.

Abstract: Provided is an electrophotographic member, which hardly changes in performance even when being left to stand for a long time period. The electrophotographic member comprises a support, an elastic layer formed on the support, and a surface layer covering a surface of the elastic layer and containing a urethane resin, and in which the urethane resin comprises a reaction product of: a hydroxyl group-terminated prepolymer obtained by reacting a polyester polyol with a polyisocyanate; and an isocyanate-terminated prepolymer obtained by reacting a polyester polyol with a polyisocyanate.

Abstract: There is provided an adhesive composition comprising (a) a polyisocyanate component comprising (i) monomeric 4,4? methylene diphenyl diisocyanate and (ii) an isocyanate functional prepolymer that is the reaction product of a prepolymer reactant mixture comprising (A) monomeric 4,4? methylene diphenyl diisocyanate, and (B) one or more polyol; and (b) a polyol component comprising one or more polyol. Also provided is a method of bonding two or more substrates comprising bringing such an adhesive composition into contact with both of said two or more substrates. Further provided is a bonded assembly comprising two or more substrates bonded together by such an adhesive composition.

Abstract: Polymerizable liquid compositions of the polyurethane type, consisting of two components (A) and (B), wherein component (A) contains at least one cyclo-aliphatic diisocyanate monomer or a mixture of one cyclo-aliphatic diisocyanate monomer and a pre-polymer obtained by reaction, in the presence of an acid phosphate ester catalyst, between said cyclo-aliphatic diisocyanate monomer and one or more polyols having two or more hydroxy 1 groups per molecule and a molecular weight ranging from 50 to 2,000 g/mole; the second component (B) contains one or more polyols having a molecular weight ranging from 50 to 2,000 g/mole and a functionality between 2 and 5; in the absence of polyalkoxylated tertiary diamines and organometallic catalysts, said components (A) and (B) being present in a weight ratio which varies from 1:1 to 2:1 and the process for the production of organic glass starting from polymerizable liquid compositions of the polyurethane type.

Abstract: The invention relates to a method for producing light-coloured polyisocyanates by phosgenation of mixtures comprising MDA and polycyclic aromatic polyamines that have o-phenylenediamine units incorporated via methylene bridges. The invention further relates to the polyisocyanate mixtures obtainable by this method.

Abstract: The present invention discloses a semicrystalline, thermoplastic polyurethane which is comprised of the reaction product of (1) a hydrophobic polyol, (2) a polyisocyanate, and (3) a linear chain extender containing 5 carbon atoms or 7 to 12 carbon atoms; wherein the hydrophobic polyol has a number average molecular weight which is within the range of about 1,000 to about 4,000; wherein the semicrystalline, thermoplastic polyurethane has a weight average molecular weight which is within the range of 50,000 to 1,000,000; and wherein the semicrystalline, thermoplastic polyurethane has a melting point which is within the range of 80° C. to 150° C. This hydrophobic thermoplastic polyurethane offers a unique array of characteristics that are highly desirable for utilization in manufacturing a variety of products. For instance, it can be used in overmolding soft grips onto consumer products, in adhesives, and in protective coatings.

Abstract: A plastic lens having excellent weather resistance, formed by polymerization of a composition containing a polyisocyanate compound having an aromatic ring and a polythiol compound is provided. The plastic lens is formed by polymerization of a composition that contains 100 parts by mass in total of (A) a polyisocyanate compound containing a polyisocyanate compound having an aromatic ring and (B) a polythiol compound, from 0.5 to 5.0 parts by mass of (C) a benzophenone compound having a hydroxyl group on at least the ortho position, and from 0.5 to 5.0 parts by mass of (D) a phenol compound.

Abstract: The present disclosure is directed to an aliphatic isocyanate-based moisture-curable resin. The disclosed resin may include an aliphatic isocyanate functional material and an cycloaliphatic isocyanate functional material. The resin may be used to formulate a coating composition that may exhibit no substantial sag when applied at a wet film thickness of at least 6 mils, and no substantial blistering when cured to a dry film thickness of at least 6 mils.

Abstract: A polyamide-imide resin insulating paint according to the present invention includes polyamide-imide resin containing no halogen element in its molecular chain which is dissolved in a polar solvent, in which the polyamide-imide resin contains an aromatic diisocyanate component (A) having three or more benzene rings or an aromatic diamine component (E) having three or more benzene rings in a monomer, and a ratio M/N between a molecular weight (M) of the polyamide-imide resin per repeat unit and an average number (N) of amide groups and imide groups is equal to or more than 200.

Abstract: A composition for the preparation of a transparent, non-elastomeric optical article is provided, the composition including: (1) a polyisocyanate component containing one or more different polyisocyanates; and (2) a component that is reactive with isocyanates, including: (a) optionally at least one polyol having a number average molecular weight greater than 500; (b) (i) at least one polyol and/or polythiol and (ii) at least one compound containing both amine and hydroxyl functional groups, wherein the compound (ii) has a number average molecular weight less than 500; and optionally (3) a urethanation catalyst. Multi-step and one-pot methods of preparing a cured, non-elastomeric polyurethane-containing optical article are also provided.

Abstract: Methods for preparing hydrophobically modified alkylene oxide urethane branched polymers. In an embodiment, the order of addition of reactants affects the properties of the resultant product urethane. In an embodiment, the time at which one or more reactants are added affects the properties of the resultant product urethane.

Abstract: A photosensitive composition includes (A) a polyurethane obtained by reacting a diol component including a compound represented by the following Formula (I) with a polyisocyanate component; and (B) a photosensitive component. In Formula (I), A represents a single bond, or a divalent linking group including an atom selected from the group consisting of a carbon atom, a hydrogen atom, and an oxygen atoms; B represents a monovalent organic group; each of R1 to R5 independently represents a hydrogen atom or an alkyl group; m represents an integer from 0 to 3; n represents an integer from 0 to 3; and m+n is not zero.

Abstract: A process for the preparation of an allophanate of one or more identical or different isocyanates, compositions obtained by the process, and uses of the compositions are disclosed. The process comprises reacting an isocyanate with at least one monoalcohol comprising an ether or polyether functional group in the presence of a bismuth-comprising catalyst and a metal compound as co-catalyst.

Abstract: A hyperbranched polyether polyol obtained by a ring-opening reaction between a hydroxyalkyloxetane (a1) and a monofunctional epoxy compound (a2), wherein the polyether polyol includes a primary hydroxyl group (H1) and a secondary hydroxyl group (H2) in the molecular structure thereof, and has a number average molecular weight (Mn) of 1,000 to 4,000 and a hydroxyl value of 150 to 350 mg·KOH/g.

Abstract: Light-stable, sinterable, thermoplastic polyurethanes with improved blooming behavior and good thermal stability as well as good technical processability are produced from an aliphatic diisocyanate using one or more chain extenders corresponding to a specified formula. These polyurethanes are particularly useful in the production of molded articles, particularly molded articles for automotive interiors.

Abstract: A polyamide-imide resin insulating coating material, which is obtained by reacting an isocyanate component with an acid component, has a main solvent component of ?-butyrolactone. In the coating material, a total compounding ratio of 4,4?-diphenylmethane diisocyanate (MDI) and trimellitic anhydride (TMA) is 85 to 98 mol %, where the total compounding ratio is given by averaging a compounding ratio of MDI to the isocyanate component and a compounding ration of TMA to the acid component.

Abstract: Disclosed is a method of producing a high-quality thiourethane-based optical material using a general-purpose polyisocyanate compound. According to the method, the pH of a polythiol compound is adjusted to 3.1 to 7 to prevent the occurrence of whitening, which is a problem of the prior art arising from the dissolution of a pressure-sensitive adhesive from a pressure-sensitive adhesive tape upon lens casting. The pH adjustment increases the reaction rate of a resin composition including the polythiol compound. The use of the polythiol compound whose pH is adjusted enables the production of a thiourethane-based optical material that does not suffer from whitening at the edges of the optical lens and nonuniformity polymerization. Further disclosed are a resin composition for a thiourethane-based optical material, and an optical material including a resin produced by the method.