Ultraviolet absorber, resin composition, pellets, molded article, compound, and method for producing compound

Abstract

Provided are: an ultraviolet absorber that can sufficiently cut blue light having a wavelength of 400 nm or greater and effectively suppress mold deposits; a resin composition; pellets; a molded article; a compound; and a method for producing the compound. The ultraviolet absorber contains a compound represented by formula (1) and / or a compound represented by formula (2). In formula (1) and formula (2), each R independently represents a halogen atom, a hydroxyl group, or a C1-12 hydrocarbon group that may be substituted with a halogen atom and / or a hydroxyl group. Each n is independently an integer of 0-4.

Description

Ultraviolet absorbent, resin composition, pellet, molded article, compound, and method for producing compound

[0001] The present invention relates to an ultraviolet absorber, a resin composition, a pellet, a molded article, a compound, and a method for producing the compound.

[0002] Molded articles made from resins deteriorate due to the action of ultraviolet rays, causing quality degradation such as discoloration and a decrease in mechanical strength, which inhibits long-term use. Furthermore, from the perspective of reducing health risks such as sunburn and eye tissue damage, as well as imparting optical functions, various studies have been conducted on blending ultraviolet absorbers into resins to block or absorb ultraviolet rays. For example, Patent Documents 1 and 2 discuss ultraviolet absorbers that efficiently absorb harmful light in the wavelength range of 380 to 400 nm and suppress absorption of light with wavelengths of 400 nm or more, which is a cause of initial yellowing.

[0003] JP 2018-522109 A International Publication No. 2020 / 137819

[0004] With the increasing use of resin materials, there is a demand for ultraviolet absorbers that, when incorporated into resins, can sufficiently cut (reduce the transmittance of) blue light with wavelengths of 400 nm or more (hereinafter sometimes referred to as "blue light") in the resulting molded product. Even with ultraviolet absorbers that can sufficiently cut blue light with wavelengths of 400 nm or more, mold deposits due to the highly volatile ultraviolet absorber can become a problem when incorporated into thermoplastic resins and molded using a mold such as injection molding, or when extrusion molding sheets or films with a large surface area per weight of the resin composition. The present invention aims to solve this problem, and provides an ultraviolet absorber that can sufficiently cut light with a wavelength of 420 nm in particular and effectively suppress mold deposits, as well as a resin composition, pellets, molded products, compounds, and a method for producing the compounds.

[0005] As a result of investigations conducted by the present inventors in light of the above-mentioned problems, it has been found that the above-mentioned problems can be solved by using an ultraviolet absorber having a specific structure. Specifically, the above-mentioned problems have been solved by the following means: <1> An ultraviolet absorber containing a compound represented by formula (1) and / or a compound represented by formula (2). (In formula (1) and formula (2), each R independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group. Each n independently represents an integer of 0 to 4.) <2> An ultraviolet absorber comprising a compound represented by formula (1). (In formula (1), R's each independently represent a hydrocarbon group having 1 to 12 carbon atoms, a halogen atom, or a hydroxyl group, which may be substituted with a halogen atom and / or a hydroxyl group. Each n's independently represent an integer of 0 to 4.) <3> The ultraviolet absorber according to <1> or <2>, wherein in formula (1), at least one R's is a hydrocarbon group having 1 to 3 carbon atoms, which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group. <4> The ultraviolet absorber according to <1> or <2>, wherein in formula (1), at least one R's is a methyl group. <5> An ultraviolet absorber comprising a compound represented by formula (3) or a compound represented by formula (4). (In formula (3), t-Bu represents a tert-butyl group.) <6> An ultraviolet absorber comprising a compound represented by formula (3) and a compound represented by formula (4). (In formula (3), t-Bu represents a tert-butyl group.) <7> A resin composition comprising a thermoplastic resin and the ultraviolet absorber according to any one of <1> to <6>. <8> The resin composition according to <7>, in which the thermoplastic resin has a total light transmittance of 85% or more when molded into a 3 mm thick test piece. <9> The resin composition according to <7> or <8>, in which the thermoplastic resin contains a polycarbonate resin. <10> The resin composition according to any one of <7> to <9>, in which the thermoplastic resin contains a polycarbonate resin and further contains a phosphorus-based stabilizer. <11> The resin composition according to any one of <7> to <10>, in which the ultraviolet absorber is contained in an amount of 0.001 to 1 part by mass per 100 parts by mass of the thermoplastic resin. <12> The resin composition according to any one of <7> to <11>, in which the light transmittance at a wavelength of 420 nm when molded into a 3 mm thick test piece is 25% or less. <13> The resin composition according to any one of <7> to <12>, wherein the thermoplastic resin has a total light transmittance of 85% or more when molded into a 3 mm thick test piece, the thermoplastic resin contains a polycarbonate resin and further contains a phosphorus-based stabilizer, and the thermoplastic resin contains 0.001 to 1 part by mass of the ultraviolet absorber per 100 parts by mass of the thermoplastic resin, and the resin composition has a light transmittance of 25% or less at a wavelength of 420 nm when molded into a 3 mm thick test piece. <14> The resin composition according to any one of <7> to <12>, wherein the thermoplastic resin has a total light transmittance of 85% or more when molded into a 3 mm thick test piece, the thermoplastic resin contains a polycarbonate resin and further contains a phosphorus-based stabilizer, and the thermoplastic resin contains more than 0.05 parts by mass and 1 part by mass or less of the ultraviolet absorber per 100 parts by mass of the thermoplastic resin, and the resin composition has a light transmittance of 5% or less at a wavelength of 400 nm and a light transmittance of 25% or less at a wavelength of 420 nm when molded into a 3 mm thick test piece.<15> The resin composition according to any one of <7> to <11>, wherein the thermoplastic resin has a total light transmittance of 85% or more when molded into a 3 mm thick test piece, the thermoplastic resin contains a polycarbonate resin and further contains a phosphorus-based stabilizer, and the thermoplastic resin contains 0.001 part by mass or more and less than 0.3 part by mass of the ultraviolet absorber per 100 parts by mass of the thermoplastic resin, and the resin composition has a light transmittance of 5% or less at a wavelength of 400 nm and a light transmittance of 50% or less at a wavelength of 420 nm when molded into a 3 mm thick test piece, and a YI (Yellow Index) of 20 or less. <16> The resin composition according to any one of <7> to <15>, wherein the ultraviolet absorber includes an ultraviolet absorber represented by formula (3): (In formula (3), t-Bu represents a tert-butyl group.) <17> A pellet formed from the resin composition according to any one of <7> to <16>. <18> A molded article formed from the resin composition according to any one of <7> to <16>. <19> A compound represented by formula (3). (In formula (3), t-Bu represents a tert-butyl group.) <20> A method for producing a compound represented by formula (1-1), which comprises heating a compound represented by formula (5-1) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group; n is an integer of 0 to 4; and Hr is a halogen atom. (In formula (1-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. Each n is independently an integer of 0 to 4.) <21> A method for producing a compound represented by formula (1-1) according to <20>, wherein the sulfidizing agent is prepared from a mercaptoalkyl acid and an alkali metal hydride. <22> A method for producing a compound represented by formula (3), comprising heating a compound represented by formula (5-1-1) with potassium thioacetate and / or disodium mercaptopropionate in the presence of an organic solvent. (In formula (5-1-1) and formula (3), t-Bu represents a tert-butyl group.) <23> A method for producing a compound represented by formula (2-1), which comprises heating a compound represented by formula (5-2) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-2), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group; n is an integer of 0 to 4; and Hr is a halogen atom. (In formula (2-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. Each n is independently an integer of 0 to 4.) <24> A method for producing a compound represented by formula (2-1) according to <23>, wherein the sulfidizing agent is prepared from a mercaptoalkyl acid and an alkali metal hydride. <25> A method for producing a compound represented by formula (4), comprising heating a compound represented by formula (5-2-1) with potassium thioacetate and / or disodium mercaptopropionate in the presence of an organic solvent.

[0006] The present invention provides an ultraviolet absorber capable of sufficiently blocking blue light having a wavelength of 400 nm or more, as well as a resin composition, pellets, molded articles, compounds, and a method for producing the compounds. Furthermore, when the ultraviolet absorber is blended with a thermoplastic resin and molded using a mold such as injection molding, mold deposits resulting from the ultraviolet absorber can be effectively suppressed.

[0007] Hereinafter, a detailed description of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be given. Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, the term "to" is used to mean that the numerical values ​​before and after it are included as the upper and lower limits. Furthermore, any combination of the upper and lower limit values ​​of numerical values ​​in this specification is cited as an example of this embodiment. In this specification, various physical property values ​​and characteristic values ​​are those at 23°C unless otherwise specified. In this specification, when a group (atomic group) is described without specifying whether it is substituted or unsubstituted, it encompasses both a group (atomic group) that has no substituent and a group (atomic group) that has a substituent. For example, the term "alkyl group" encompasses not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group). In this specification, when a term without specifying whether it is substituted or unsubstituted, it is preferred that it be unsubstituted. Examples of the substituent in this specification are preferably a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a heterocyclicoxy group, an alkenyl group, an alkylsulfanyl group, an arylsulfanyl group, an acyl group, or an amino group, more preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, or an acyl group, even more preferably an alkyl group, an aryl group, an aryloxy group, or an alkenyl group, and still more preferably an alkyl group. The formula weight of these substituents is preferably 15 or more, and preferably 200 or less. The formula weight is, for example, the formula weight of a methyl group (-CH ３ ), the value is 15. These substituents may further have a substituent, but it is preferable that they have no substituent. If the measurement methods etc. described in the standards shown in this specification vary from year to year, they shall be based on the standards as of January 1, 2023, unless otherwise specified. If the measurement methods etc. described in the standards shown in this specification have been abolished as of January 1, 2023, they shall be based on the standards at the time of abolition.

[0008] The ultraviolet absorber of the present embodiment is characterized by containing a compound represented by formula (1) and / or a compound represented by formula (2). (In formula (1) and formula (2), each R independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group. Each n independently represents an integer of 0 to 4.) Such an ultraviolet absorber can sufficiently block blue light having a wavelength of 400 nm or more, and can effectively suppress mold deposits resulting from the ultraviolet absorber even when blended with a thermoplastic resin and molded.

[0009] In formula (1) and formula (2), each R independently represents a hydrocarbon group having 1 to 12 carbon atoms, a halogen atom, or a hydroxyl group, which may be substituted with a halogen atom and / or a hydroxyl group. Preferably, R represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms, a halogen atom, or a hydroxyl group. More preferably, R represents an unsubstituted hydrocarbon group having 1 to 12 carbon atoms. The hydrocarbon group is preferably an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and more preferably an alkyl group. The alkyl group is preferably a linear or branched alkyl group. The number of carbon atoms in the hydrocarbon group is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and even more preferably 4 or more, and is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, even more preferably 5 or less, and even more preferably 4 or less. By setting the R at or above the lower limit, solubility in thermoplastic resins tends to be further improved. Furthermore, by setting the R at or below the upper limit, the effect of reducing the transmittance of blue light having a wavelength of 400 nm or more tends to be further improved. An example of the hydrocarbon group is a methyl group. Another example of the hydrocarbon group is a t-butyl group. The halogen atom is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom.

[0010] In formula (1), at least one of R is preferably a hydrocarbon group having 1 to 4 carbon atoms which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group, and more preferably at least one of R is a methyl group.

[0011] In formula (1), n's are each independently an integer of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 2. Furthermore, the total number of R's in one molecule of the compound represented by formula (1) is preferably an integer of 0 to 6, more preferably 2 or 4, and even more preferably 4.

[0012] In formula (2), n's are each independently an integer of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, further preferably 0 or 1, and even more preferably 0. Furthermore, the total number of R's in one molecule of the compound represented by formula (2) is preferably an integer of 0 to 2, more preferably 0 or 2, and further preferably 0.

[0013] In addition, in formula (1) and formula (2), it is preferable that the number of R bonded to one ring, i.e., n, of R, which is a hydrocarbon group having 4 or more carbon atoms, is 1 or less. When n is 1 or less, the amount added can be reduced while maintaining excellent blue light blocking performance, and the heat resistance and mechanical properties of the obtained molded article tend to be further improved.

[0014] Furthermore, the compound represented by formula (1) or formula (2) is preferably symmetrical.

[0015] The molecular weight of the compound represented by formula (1) or formula (2) is preferably 400 or more, more preferably 450 or more, and preferably 800 or less, more preferably 700 or less, and even more preferably 600 or less. By setting the molecular weight at or above the lower limit, mold deposits tend to be effectively reduced. Furthermore, by setting the molecular weight at or below the upper limit, the effect of reducing the transmittance of blue light having a wavelength of 400 nm or more tends to be further improved.

[0016] The ultraviolet absorber of this embodiment preferably contains a compound represented by formula (1). The ultraviolet absorber of this embodiment also preferably contains a compound represented by formula (3) and / or a compound represented by formula (4). One example of the ultraviolet absorber of this embodiment contains a compound represented by formula (3) or a compound represented by formula (4). Another example of the ultraviolet absorber of this embodiment contains a compound represented by formula (3) and a compound represented by formula (4). Yet another example of the ultraviolet absorber of this embodiment contains a compound represented by formula (3). Yet another example of the ultraviolet absorber of this embodiment contains a compound represented by formula (4). (In formula (3), t-Bu represents a tert-butyl group.)

[0017] The ultraviolet absorber of the present embodiment preferably does not contain the compounds shown below. By not containing the compounds shown below, the effect of reducing the transmittance of blue light having a wavelength of 400 nm or more tends to be more effectively exhibited. (In the above formula, t-Bu represents a tert-butyl group.)

[0018] The ultraviolet absorber of this embodiment preferably has the ability to cut blue light having a wavelength of 380 to 430 nm, particularly 400 to 430 nm. The ultraviolet absorber of this embodiment preferably has a maximum absorption wavelength (also referred to as maximum absorption wavelength) in a wavelength region of 370 nm or more, and preferably has a maximum absorption wavelength in a wavelength region of 450 nm or less, more preferably 400 nm or less, because this results in small coloration (YI) of molded articles of the resin composition.

[0019] The ultraviolet absorbent of this embodiment can be produced by a known method.

[0020] This embodiment also discloses a method for producing a compound represented by formula (1-1), which includes heating a compound represented by formula (5-1) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-1), R １are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group; n is an integer of 0 to 4; and Hr is a halogen atom. (In formula (1-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. Each n is independently an integer of 0 to 4.

[0021] In formula (5-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms, optionally substituted with a hydroxyl group, or a hydrocarbon group having 1 to 12 carbon atoms, which is a hydroxyl group and has no substituent. The hydrocarbon group is preferably an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and more preferably an alkyl group. The alkyl group is preferably a linear or branched alkyl group. The number of carbon atoms in the hydrocarbon group is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and still more preferably 4 or more, and is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, still more preferably 5 or less, and still more preferably 4 or less. By setting the carbon number at or above the lower limit, the solubility of the raw materials tends to be increased, and the yield tends to be improved. Furthermore, by setting the carbon number at or below the upper limit, the effect of reducing the transmittance of blue light having a wavelength of 400 nm or more tends to be further improved. An example of the hydrocarbon group is a methyl group. Another example of the hydrocarbon group is a t-butyl group. The halogen atom is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a chlorine atom.

[0022] In formula (5-1), n ​​is each independently an integer of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 2. １ and n each independently represent R in formula (5-1). １and n have the same meanings as those of the compound represented by formula (1), and the preferred ranges are also the same. In addition, the preferred range of formula (1-1) has the same meaning as that of the compound represented by formula (1) (provided that R １ (Except).

[0023] In addition, as a preferred embodiment, there is exemplified a method for producing a compound represented by formula (3) using a compound represented by formula (5-1-1) as the compound represented by formula (5-1). (In formula (5-1-1) and formula (3), t-Bu represents a tert-butyl group.)

[0024] In this embodiment, the compound represented by formula (5-1) and a sulfidizing agent are heated in the presence of an organic solvent. The sulfidizing agent may be any agent capable of introducing a sulfide bond into the compound represented by formula (5-1) to synthesize the compound represented by formula (1-1), and examples of the sulfidizing agent include alkaline (earth) metal sulfides.

[0025] Specific examples of alkali (earth) metal sulfides include alkali (earth) metal salts of mercaptoalkyl acids, lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, calcium sulfide, and mixtures of two or more thereof. Among these, alkali (earth) metal salts of mercaptoalkyl acids, lithium sulfide, and / or sodium sulfide are preferred. While these alkali (earth) metal sulfides can be used in anhydrous form, they are preferably used as hydrates or aqueous mixtures from the standpoints of availability and cost, with hydrated alkali (earth) metal sulfides being particularly preferred. Note that an aqueous mixture refers to an aqueous solution, a mixture of an aqueous solution and a solid component, or a mixture of water and a solid component. Using a hydrate or aqueous mixture as a sulfidizing agent tends to increase miscibility with organic solvents, making it a preferred embodiment from the standpoint of reaction efficiency.

[0026] In addition, alkali(earth) metal sulfides prepared in the reaction system from a mercaptoalkyl acid and an alkali(earth) metal, alkali(earth) metal hydride, or alkaline earth metal carbonate such as calcium carbonate can also be used as the sulfidizing agent. Furthermore, alkali(earth) metal sulfides prepared in advance by contacting a mercaptoalkyl acid with an alkali(earth) metal hydroxide can also be used. The sulfidizing agent does not need to be isolated or purified; after preparation in a reaction solution, the compound represented by formula (5-1) can be added to the reaction solution to produce the compound represented by formula (1-1). This procedure simplifies the production process. Mercaptoalkyl acids are preferably mercaptoacetic acid and mercaptopropionic acid from the standpoint of availability, with mercaptopropionic acid being particularly preferred from the standpoint of handling, such as odor. Sodium and potassium are preferred as alkali metals, and calcium is preferred as alkaline earth metals. Sodium hydride and potassium hydride are preferred as alkali metal hydrides, and calcium hydride is preferred as alkaline earth metal hydrides. From the viewpoint of safety and handling, alkali (earth) metal hydrides and alkali (earth) metal carbonates are preferably used, among which sodium hydride and calcium carbonate are preferably used, with sodium hydride being particularly preferred. Preferred examples of the alkali (earth) metal mercaptoalkyl acid salts include disodium mercaptopropionate, calcium mercaptopropionate, and potassium thioacetate, with potassium thioacetate and / or disodium mercaptopropionate being preferred.

[0027] The amount of the sulfidizing agent used is preferably 0.5 moles or more, more preferably 1 mole or more, and even more preferably 2 moles or more, relative to 1 mole of the compound represented by formula (5-1), and is preferably 20 moles or less, more preferably 10 moles or less, and even more preferably 5 moles or less. In the method for producing the compound represented by formula (1-1) of this embodiment, only one type of sulfidizing agent may be used, or two or more types may be used. When two or more types are used, the total amount is preferably within the above range.

[0028] In the method for producing the compound represented by formula (1-1) of this embodiment, as described above, the sulfidation reaction is carried out in the presence of an organic solvent. There are no particular limitations on the organic solvent, so long as it does not inhibit the sulfidation reaction, decompose the product, or substantially cause undesirable side reactions. Specific examples of such organic solvents include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone (NMP), N-methylcaprolactam, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), 1,3-dimethyl-2-imidazolidinone (DMI), hexamethylphosphoramide, and tetramethylurea; sulfoxide / sulfone solvents such as dimethyl sulfoxide (DMSO), dimethyl sulfone, diphenyl sulfone, and sulfolane; nitrile solvents such as benzonitrile; diaryl ethers such as diphenyl ether; ketones such as acetone, benzophenone, and acetophenone; aromatic hydrocarbons such as benzene, toluene, and xylene; and mixtures thereof. Among these, nitrogen-containing polar solvents are preferred, and N,N-dimethylformamide (DMF) is more preferred.

[0029] In the method for producing the compound represented by formula (1-1) of this embodiment, a surfactant may be added. Addition of a surfactant may improve the affinity between the sulfidizing agent and the compound represented by formula (5-1) in the solvent, thereby improving the yield. Specific examples of surfactants include quaternary ammonium salts, phosphonium salts, crown ethers, (poly)alkylene glycols, cyclodextrins, alkyl fatty acid salts, and alkyl sulfates.

[0030] The amount of organic solvent used in this embodiment is preferably 0.1 mol or more, more preferably 0.5 mol or more, and even more preferably 1 mol or more, relative to 1 mol of the sulfidizing agent, and is preferably 200 mol or less, more preferably 100 mol or less, and even more preferably 50 mol or less. In the method for producing a compound represented by formula (1-1) of this embodiment, only one organic solvent may be used, or two or more organic solvents may be used. When two or more organic solvents are used, the total amount is preferably within the above range.

[0031] In the method for producing a compound represented by formula (1-1) of this embodiment, as described above, the sulfidation reaction is carried out by heating. The reaction temperature is preferably 40°C or higher, more preferably 60°C or higher, even more preferably 80°C or higher, still more preferably 100°C or higher, and even more preferably 120°C or higher, and is preferably 250°C or lower, more preferably 225°C or lower, still more preferably 200°C or lower, even more preferably 175°C or lower, and even more preferably 150°C or lower. By setting the temperature at or above the lower limit, the effect of increasing the reaction yield tends to be more improved. Furthermore, by setting the temperature at or below the upper limit, the effect of reducing by-products tends to be more improved. In the method for producing a compound represented by formula (1-1) of this embodiment, the reaction time of the sulfidation reaction is preferably 1 hour or longer, more preferably 10 hours or longer, and even more preferably 20 hours or longer, and is preferably 200 hours or shorter, and more preferably 100 hours or shorter.

[0032] The present embodiment also discloses a method for producing a compound represented by formula (2-1), which comprises heating a compound represented by formula (5-2) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-2), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group; n is an integer of 0 to 4; and Hr is a halogen atom. (In formula (2-1), R １ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. Each n is independently an integer of 0 to 4.

[0033] In formula (5-2), R １ , n and Hr are R in formula (5-1). １ , n and Hr, and the preferred ranges are also the same.

[0034] In addition, as a preferred embodiment, there is exemplified a method for producing a compound represented by formula (4) using a compound represented by formula (5-2-1) as the compound represented by formula (5-2).

[0035] R in formula (2-1) １ and n each independently represent R in formula (5-2). １ The preferred range of the formula (2-1) is the same as the preferred range of the compound represented by the formula (2) (provided that R １(excluding the above), and further preferably a compound represented by formula (4). The hydrocarbon group is preferably an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and more preferably an alkyl group. The alkyl group is preferably a linear or branched alkyl group. The number of carbon atoms in the hydrocarbon group is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and still more preferably 4 or more, and is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, still more preferably 5 or less, and still more preferably 4 or less. By setting the carbon number to be equal to or greater than the lower limit, solubility in the reaction solvent tends to be further improved. Furthermore, by setting the carbon number to be equal to or less than the upper limit, absorption at a wavelength of 400 nm tends to be further improved. An example of the hydrocarbon group is a methyl group.

[0036] In formula (5-2), n is each independently an integer of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and still more preferably 0. In formula (5-2), Hr is a halogen atom, preferably a fluorine atom, a chlorine atom, or a bromine atom, and more preferably a bromine atom.

[0037] R in formula (2-1) １ and n each independently represent R in formula (5-2). １ and n have the same meanings as those of the compounds represented by formula (2-1), and the preferred ranges are also the same. １ (Except).

[0038] In this embodiment, the compound represented by formula (5-2) and a sulfidizing agent are heated in the presence of an organic solvent. The type and amount of the sulfidizing agent and the organic solvent are the same as those of the sulfidizing agent and the organic solvent in the method for producing the compound represented by formula (1-1), and the preferred ranges are also the same. The reaction temperature and reaction time of the sulfidizing reaction are the same as those of the sulfidizing reaction in the method for producing the compound represented by formula (1-1), and the preferred ranges are also the same.

[0039] The 5% weight loss temperature of the compound represented by formula (1-1) and the compound represented by formula (2-1) measured with a differential scanning calorimeter (heating rate: 10°C / min) is preferably 320°C or higher, more preferably 360°C or higher, even more preferably 380°C or higher, and even more preferably 390°C or higher. Although a higher 5% weight loss temperature is more preferable, a temperature of 420°C or lower is practical. By setting the temperature at or above the lower limit, mold deposits can be effectively suppressed even when molding at high temperatures or when molding molded articles with a large surface area per weight. Examples of molding at high temperatures include molding resin compositions with high molding temperatures, such as polycarbonate resins, particularly highly heat-resistant special polycarbonates, and molding at high temperatures to suppress distortion during molding. Examples of molded articles with a large surface area per weight include flat molded articles such as sheets and films.

[0040] Methods for purifying the compounds obtained by the present invention include purification methods such as crystallization and column chromatography. Specific examples of organic solvents used in this crystallization purification include alcohols such as isopropyl alcohol, ester solvents such as ethyl acetate and butyl acetate, nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone (NMP), N-methylcaprolactam, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), 1,3-dimethyl-2-imidazolidinone (DMI), hexamethylphosphoramide, and tetramethylurea, sulfoxide / sulfone solvents such as dimethyl sulfoxide (DMSO), dimethyl sulfone, diphenyl sulfone, and sulfolane, nitrile solvents such as benzonitrile, diaryl ethers such as diphenyl ether, ketones such as acetone, benzophenone, and acetophenone, aromatic hydrocarbons such as benzene, toluene, and xylene, and mixtures thereof. Among these, aromatic hydrocarbons such as toluene and xylene, alcohol solvents such as isopropyl alcohol, and ester solvents such as ethyl acetate and butyl acetate are more preferred.

[0041] The use of the ultraviolet absorber of this embodiment is not particularly limited, and it can be widely used in applications in which ultraviolet absorbers are generally used. Specifically, the ultraviolet absorber of this embodiment is blended into materials such as thermoplastic resins and thermosetting resins. It is also widely used in adhesives, cosmetics, coating agents, paints, inks, etc. The ultraviolet absorber of this embodiment is preferably used as an ultraviolet absorber for thermoplastic resins because it is unlikely to cause mold deposits when blended into a thermoplastic resin and molded with a mold.

[0042] Next, a resin composition according to the present embodiment will be described. The resin composition according to the present embodiment contains a thermoplastic resin and the ultraviolet absorber according to the present embodiment. A molded article formed from such a resin composition has excellent ultraviolet absorption properties and generates little mold deposits derived from the ultraviolet absorber during molding.

[0043] The thermoplastic resin contained in the resin composition of this embodiment is not particularly limited in type, and examples thereof include polycarbonate resin, polyphenylene ether resin, polystyrene resin, polyamide resin alloy, thermoplastic polyester resin, acrylic resin, polyacetal resin, polylactic acid resin, polyolefin resin, etc. Preferably, the resin composition contains at least one of acrylic resin, amorphous polyester resin, and polycarbonate resin, more preferably at least one of acrylic resin and polycarbonate resin, and even more preferably polycarbonate resin. Furthermore, it is also preferable to contain polycarbonate resin and acrylic resin, as this improves transparency and hardness. In this case, it is preferable to contain 10 to 100 parts by mass of acrylic resin per 100 parts by mass of polycarbonate resin.

[0044] The polycarbonate resin is not particularly limited as long as it contains an -[O-R-OC(═O)]- unit containing a carbonate bond in the molecular main chain (wherein R is an organic group, preferably a hydrocarbon group, more preferably an aliphatic group, an aromatic group, or one containing both an aliphatic group and an aromatic group, and further one having a linear or branched structure). In this embodiment, the polycarbonate resin is preferably an aromatic polycarbonate resin, more preferably a polycarbonate resin having a bisphenol skeleton, even more preferably at least one of bisphenol A polycarbonate resin, bisphenol C polycarbonate resin, and bisphenol AP polycarbonate resin, and even more preferably a bisphenol A polycarbonate resin. By using such a polycarbonate resin, better heat resistance and toughness can be achieved. In the present embodiment, the polycarbonate resin having a bisphenol skeleton preferably contains structural units having a bisphenol skeleton (preferably structural units having a bisphenol A skeleton) in an amount of 90 mol % or more of all structural units, and more preferably contains structural units having a bisphenol skeleton in an amount of 95 mol % or more of all structural units.

[0045] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, and even more preferably 15,000 or more. By setting it to the lower limit or more, the durability of the obtained molded article tends to be further improved. The upper limit of the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 35,000 or less, more preferably 32,000 or less, and even more preferably 30,000 or less. By setting it to the upper limit or less, the molding processability of the molded article tends to be further improved. The viscosity average molecular weight (Mv) is determined by using methylene chloride as a solvent and an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dL / g) at a temperature of 25°C, and then calculating the viscosity average molecular weight (Mv) using Schnell's viscosity formula, i.e., η = 1.23 × 10 -４ ×Mv ０．８３ When two or more types of polycarbonate resins are used, the viscosity average molecular weight is the viscosity average molecular weight of the mixture.

[0046] The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resins produced by the conventionally known phosgene method (interfacial polymerization method) or melt method (ester interchange method) can be used. In addition, when the melt method is used, a polycarbonate resin having an adjusted amount of OH groups at the terminal groups can be produced.

[0047] In addition to the above, for details of the polycarbonate resin, please refer to the descriptions in paragraphs 0008 to 0013 of JP 2008-120866 A, the descriptions in paragraphs 0013 to 0041 of JP 2021-084942 A, and the descriptions in paragraphs 0030 to 0035 of JP 2021-119211 A, the contents of which are incorporated herein. For thermoplastic polyester resins, please refer to the descriptions in paragraphs 0013 to 0016 of JP 2010-174223 A, the contents of which are incorporated herein. For amorphous polyester resins, please refer to the descriptions in paragraphs 0034 to 0043 of Japanese Patent No. 6607335 A, the contents of which are incorporated herein. For details of polyacetal resins, please refer to paragraph 0011 of JP-A No. 2003-003041 and paragraphs 0018 to 0020 of JP-A No. 2003-220667, the contents of which are incorporated herein by reference. For details of polyamide resins, please refer to paragraphs 0011 to 0013 of JP-A No. 2011-132550, the contents of which are incorporated herein by reference.

[0048] Examples of styrene-based resins include styrene resins, as well as acrylonitrile / styrene copolymer resins, acrylonitrile / styrene / butadiene copolymer resins, methyl methacrylate / acrylonitrile / butadiene / styrene copolymer resins, and methyl methacrylate / styrene copolymer resins. Styrenic resins typically have 50% or more by mass of their constituent units derived from styrene or a styrene derivative. Examples of acrylic resins include methyl methacrylate resin (PMMA), rubber-reinforced methyl methacrylate resin, methyl methacrylate / acrylonitrile / butadiene / styrene copolymer resin, and methyl methacrylate / styrene copolymer resin. For acrylic resins, please refer to the description in paragraphs 0037 to 0069 of JP 2018-87268 A, the contents of which are incorporated herein by reference. When the acrylic resin having aromatic (meth)acrylate units described in the above publication is used as the polycarbonate resin, a polycarbonate resin composition having excellent surface hardness, transparency, particularly during high-speed injection molding, and thermal stability during retention can be obtained, as can molded articles made from this polycarbonate resin composition. The acrylic resin preferably contains at least 50% by mass of its constituent units derived from (meth)acrylate, and more preferably at least 90% by mass derived from (meth)acrylate, as this provides high total light transmittance and excellent transparency. Examples of acrylic resins include methyl methacrylate resins "MODAP BP1010R" and "MODAP BP2010R" manufactured by Mitsubishi Gas Chemical Company, Inc., and methyl methacrylate resin "Altuglas V020" manufactured by Arkema.

[0049] The thermoplastic resin may be either an amorphous resin or a crystalline resin, but an amorphous resin is preferred because it has a high total light transmittance and excellent transparency. Furthermore, the thermoplastic resin preferably has a total light transmittance of 85% or more, more preferably 89% or more, and even more preferably 90% or more, and 100% or less, when molded into a 3 mm thick test piece. The total light transmittance is the total light transmittance measured according to the light transmittance measurement method described in the Examples below.

[0050] The thermoplastic resin (particularly, polycarbonate resin) used in this embodiment may be a recycled thermoplastic resin product (including recovered products, material recycled products, chemical recycled products, etc.), a rejected product, or a scrap material from thermoplastic resin molding.

[0051] The proportion of the thermoplastic resin (particularly, polycarbonate resin) in the resin composition of this embodiment is preferably 83% by mass or more, more preferably 85% by mass or more, and even more preferably 87% by mass or more. Furthermore, the proportion of the thermoplastic resin (particularly, polycarbonate resin) in the resin composition of this embodiment is preferably 99.9% by mass or less. The resin composition of this embodiment may contain only one type of thermoplastic resin (particularly, polycarbonate resin), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0052] As described above, the resin composition of the present embodiment contains the ultraviolet absorber of the present embodiment, and preferably contains an ultraviolet absorber represented by formula (1), and more preferably contains an ultraviolet absorber represented by formula (3).

[0053] The content of the ultraviolet absorber in the resin composition of this embodiment is preferably 0.0001 parts by mass or more, more preferably 0.001 parts by mass or more, even more preferably 0.005 parts by mass or more, even more preferably 0.01 parts by mass or more, even more preferably 0.03 parts by mass or more, even more preferably 0.05 parts by mass or more, and preferably 3 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.8 parts by mass or less, even more preferably 0.7 parts by mass or less, even more preferably 0.6 parts by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.4 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin. By setting the content at or above the lower limit, the effect of reducing the transmittance of blue light having a wavelength of 400 nm or more tends to be more improved. Furthermore, by setting the content at or below the upper limit, the effect of reducing mold deposits tends to be more improved. Furthermore, when the compound represented by formula (3) is used as an ultraviolet absorber, the compound is preferably incorporated in an amount of at least 0.001 parts by weight, more preferably at least 0.01 parts by weight, even more preferably at least 0.02 parts by weight, even more preferably at least 0.03 parts by weight, particularly preferably more than 0.05 parts by weight, preferably at most 1 part by weight, more preferably at most 0.5 parts by weight, even more preferably at most 0.4 parts by weight, even more preferably at most 0.3 parts by weight, even more preferably at most 0.2 parts by weight, and particularly preferably at most 0.1 parts by weight. Even at such a low amount, it is possible to sufficiently block blue light with wavelengths of 400 nm or more, even 420 nm or more, and it is also possible to reduce the YI (Yellow Index) measured by the method described in the Examples, which is preferable because it also has the effect of reducing mold deposits. The YI is preferably at most 25, more preferably at most 20, even more preferably at most 15, and particularly preferably at most 5. The lower limit of the YI is not particularly limited, but a practical value is 0.1 or more. Furthermore, when the compound represented by formula (3) and the compound represented by formula (4) are used in combination as ultraviolet absorbers, ultraviolet rays with wavelengths of 320 nm or more and blue light with wavelengths of 400 nm or more can be blocked, which is preferable.In this case, the mass ratio of the compound represented by formula (3) to the compound represented by formula (4) (compound represented by formula (3) / compound represented by formula (4)) is preferably 0.005 to 2. The resin composition of the present embodiment may contain only one type of ultraviolet absorber, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0054] The resin composition of this embodiment may or may not contain an ultraviolet absorber other than the ultraviolet absorber of this embodiment. For example, to suppress yellowing of thermoplastic resins such as polycarbonate resins, an ultraviolet absorber that is highly effective in absorbing ultraviolet light with wavelengths shorter than 400 nm may be added. Examples of such ultraviolet absorbers include "Seesorb 709" manufactured by Shipro Kasei Co., Ltd. and "ADK STAB LA-31RG" manufactured by Adeka Corporation.

[0055] The resin composition of this embodiment may contain other components in addition to those described above, as necessary, as long as the desired physical properties are not significantly impaired. Examples of such other components include various resin additives and fillers. Examples of resin additives include reactive compounds (e.g., epoxy compounds and / or oxetane compounds), stabilizers, release agents, colorants (dyes, pigments), antistatic agents, flame retardants, flame retardant assistants, anti-dripping agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. One type of resin additive may be contained, or two or more types may be contained in any combination and ratio. The content of the resin additive in the resin composition is preferably 0 to 3% by mass, more preferably 0 to 1% by mass.

[0056] <<Stabilizer>> As the stabilizer, a phosphorus-based stabilizer is preferred. In particular, when a polycarbonate resin is used as the thermoplastic resin, it is preferable to use a phosphorus-based stabilizer. By incorporating a phosphorus-based stabilizer, the transparency of the molded article becomes good. Preferred examples of the phosphorus-based stabilizer include a phosphite-based stabilizer (C-I) having a spiro ring skeleton (hereinafter sometimes simply referred to as the "phosphite-based stabilizer (C-I)") and a phosphite-based stabilizer (C-II) represented by formula (II) (hereinafter sometimes simply referred to as the "phosphite-based stabilizer (C-II)"), and one or more of these may be used.

[0057] (In formula (II), R ２５ ~R ２９ each independently represents a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.

[0058] <Phosphite-Based Stabilizer (CI)> The phosphite-based stabilizer (CI) is not particularly limited as long as it is a phosphite-based compound having a spiro ring skeleton, but for example, one represented by the following formula (I) is preferred.

[0059] (In formula (I), R １０Ａ and R １０Ｂ each independently represents an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms.

[0060] In formula (I), R １０Ａ , R １０Ｂ Each of the alkyl groups represented by R is preferably a linear or branched alkyl group having 1 to 10 carbon atoms. １０Ａ , R １０Ｂ When is an aryl group, it is preferably an aryl group represented by any one of the following general formulas (I-1), (I-2), and (I-3).

[0061] (In formula (I-1), R Ａ represents an alkyl group having 1 to 10 carbon atoms. Ｂ represents an alkyl group having 1 to 10 carbon atoms.

[0062] An example of the phosphite stabilizer (CI) is bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite represented by the following structural formula (IA).

[0063]

[0064] As the phosphite-based stabilizer (CI), compounds represented by the following general formula (IB) are also preferred.

[0065] (In formula (IB), R １１ ~R １８ each independently represents a hydrogen atom or an alkyl group, and R １９ ~R ２２ each independently represents an alkyl group, an aryl group, or an aralkyl group, and a to d each independently represent an integer of 0 to 3.

[0066] In the above general formula (IB), R １１ ~R １８ are each independently preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group; and a to d are each preferably 0.

[0067] The compound represented by the above general formula (IB) is preferably bis(2,4-dicumylphenyl)pentaerythritol diphosphite represented by the following structural formula (Ib).

[0068]

[0069] The above phosphite-based stabilizers (CI) may be used alone or in combination of two or more.

[0070] <Phosphite-Based Stabilizer (C-II)> The phosphite-based stabilizer (C-II) is represented by the general formula (II). ２５ ~R ２９ Examples of the alkyl group represented by the formula (I) include a methyl group, an ethyl group, a propyl group, an n-propyl group, an n-butyl group, a tert-butyl group, a hexyl group, and an octyl group.

[0071] As the phosphite-based stabilizer (C-II), tris(2,4-di-tert-butylphenyl)phosphite represented by the following structural formula (II-A) is particularly preferred.

[0072]

[0073] The phosphite stabilizer (C-II) may be used alone or in combination of two or more kinds.

[0074] When a stabilizer (preferably a phosphorus-based stabilizer) is contained, the content thereof is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, even more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin (preferably a polycarbonate resin). The content is preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, even more preferably 0.7 parts by mass or less, even more preferably 0.6 parts by mass or less, and even more preferably 0.5 parts by mass or less. By setting the content to be equal to or greater than the lower limit, the total light transmittance tends to be further improved. Furthermore, by setting the content to be equal to or less than the upper limit, the mold deposit reduction effect tends to be further improved. The resin composition of this embodiment may contain only one stabilizer (preferably a phosphorus-based stabilizer), or may contain two or more types. When two or more types are contained, the total amount preferably falls within the above range.

[0075] The resin composition of this embodiment preferably has excellent light shielding properties (ultraviolet shielding properties) at a wavelength of 400 nm. Specifically, the resin composition of this embodiment has a light transmittance at a wavelength of 400 nm when molded into a 3 mm thick test piece, of preferably 25% or less, more preferably 10% or less, more preferably 5% or less, even more preferably less than 3%, even more preferably less than 1%, and may even be 0%.

[0076] Furthermore, the resin composition of this embodiment satisfies the above-mentioned light transmittance at a wavelength of 400 nm, and when molded into a 3 mm thick test piece, the light transmittance at a wavelength of 420 nm is preferably 50% or less, more preferably 25% or less, even more preferably 10% or less, and even more preferably 5% or less, and may even be 0%. For applications requiring such properties, an ultraviolet absorber containing a compound represented by formula (1), preferably formula (3), is suitably used.

[0077] On the other hand, for applications requiring sharp wavelength selectivity, the resin composition of this embodiment satisfies the above light transmittance, and when the resin composition of this embodiment is molded into a 3 mm thick test piece, the light transmittance at a wavelength of 420 nm is preferably greater than 5%, more preferably greater than 10%, even more preferably greater than 25%, even more preferably greater than 50%, and even more preferably greater than 80%. For applications requiring such properties, an ultraviolet absorber containing a compound represented by formula (2), preferably formula (4), is suitably used. The light transmittance is measured according to the description in the Examples below. When the resin composition of this embodiment is used for applications requiring transparency, when the resin composition is molded into a 3 mm thick test piece, the total light transmittance is preferably 85% or more, more preferably 88% or more, even more preferably 89% or more, even more preferably 90% or more, and 100% or less. The total light transmittance is the total light transmittance measured according to the light transmittance measurement described in the Examples below.

[0078] <Method of Manufacturing Resin Composition> The method of manufacturing the resin composition of this embodiment is not limited, and a wide variety of known methods for manufacturing resin compositions can be used. For example, a method can be used in which a thermoplastic resin, the UV absorber of this embodiment, and other components that are added as needed are pre-mixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, or a kneader. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C.

[0079] <Molded Article> The molded article of this embodiment is formed from the resin composition or pellets of this embodiment. The above-mentioned resin composition (e.g., pellets) is molded into a molded article by various molding methods. The shape of the molded article is not particularly limited and can be appropriately selected depending on the use and purpose of the molded article. Examples include film-like, rod-like, cylindrical, ring-like, circular, elliptical, polygonal, irregular-shaped, hollow, frame-like, box-like, panel-like, and button-like shapes.

[0080] The method for molding the molded article is not particularly limited, and conventionally known molding methods can be used, such as injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding), rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding. In particular, the resin composition of this embodiment is suitable for molding methods using a mold, such as injection molding, injection compression molding, and extrusion molding. However, it goes without saying that the resin composition of this embodiment is not limited to molded articles obtained by these methods.

[0081] The molded article of the present embodiment is preferably used for eyewear parts, electrical and electronic equipment / components, office automation equipment / components, information terminal equipment / components, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and miscellaneous goods, lighting equipment, and the like, and more specifically, is preferably used for transparent members such as eyeglass lenses, sunglasses, power covers, lighting lenses, lighting covers, and light-guiding members.

[0082] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0083] Synthesis Example 1 Synthesis of UV-1 UV-1 was synthesized as follows.

[0084] Under an argon atmosphere, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole (hereinafter referred to as "UV-3") (1.00 g, 3.15 mmol, 1.97 eq), potassium thioacetate (0.183 g, 1.60 mmol, 1.00 eq), 1,1'-bis(diphenylphosphino)ferrocene (DPPF, 0.0929 g, 0.168 mmol, 0.105 eq), tris(dibenzylideneacetone)dipalladium(0) (Pd ２ (dba) ３ (0.102 g, 0.111 mmol, 0.07 eq), dehydrated toluene (20 mL), and dehydrated acetone (10 mL) were added, and the mixture was heated and stirred at 130°C with argon purging for 5 minutes. After 46.5 hours, the reaction mixture was cooled, filtered through Celite, washed with chloroform, and the filtrate was evaporated under reduced pressure. 1.29 g of a dark brown amorphous substance was obtained as a crude product. The crude toluene solution was adsorbed onto a silica gel column (φ=2 cm column tube, 40 g of silica gel) and then purified by column chromatography using a 1 / 1 toluene / hexane mixed solvent to obtain 0.30 g (0.50 mmol, yield=31.1%) of a pale yellow solid as 6,6'-(thiobis(2H-benzo[d][1,2,3]triazole-5,2-diyl))bis(2-(t-butyl)-4-methylphenol) (hereinafter referred to as UV-1).

[0085] Synthesis Example 2: Synthesis of UV-1 In a nitrogen atmosphere, 65% pure sodium hydride (50 g, 1.36 mol) was slowly added to ethanol (666.8 g, 14.5 mol) in a 5 L pressure vessel, and 3-mercaptopropionic acid was added dropwise over 1 hour at 20°C or below. The solvent was recovered by heating, yielding 140 g (0.6 mol) of disodium mercaptopropionate, which serves as a sulfidizing agent. UV-3 (179 g, 0.1 mol) and 800 g of N,N-dimethylformamide were then added, and the mixture was allowed to react at 150°C for 48 hours. 400 g of aqueous hydrochloric acid was added to the reaction solution for neutralization, followed by crystallization. The mixture was dissolved by heating using toluene and ethyl acetate, 10 g of activated carbon was added, and crystallization was carried out multiple times by hot filtration, yielding 104 g (0.173 mol, 61% yield) of a pale yellow solid (UV-1).

[0086] The mass spectra of the compounds (UV-1) obtained in Synthesis Examples 1 and 2 are as follows: [M / H]+ m / z 593.329

[0087] The NMR spectra of the compounds (UV-1) obtained in Synthesis Examples 1 and 2 are as follows: １ H-NMR (CDCl ３ 500MHz): δ1.49(s, 18H, -C(CH ３ ) ３ ), 2.38(s, 6H, -CH ３ ), 7.18 (d, 2H), 7.47 (dd, 2H), 7.90 (dd, 2H), 7.92-7.93 (m, 2H), 8.06 (d, 2H), 11.51 (s, 2H, -OH)

[0088] The 5% weight loss temperature of the obtained compound (UV-1) measured with a differential scanning calorimeter (heating rate 10°C / min) was 385°C, demonstrating extremely high heat resistance that contributes to reducing mold deposits.

[0089] Synthesis Example 3: Synthesis of UV-2 UV-2 was synthesized as follows. Under an argon atmosphere, 2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-methylphenol (2.09 g, 9.29 mmol, 1.23 eq) and dehydrated 1,2-dichloroethane (20 mL) were placed in a 100 mL recovery flask, and bromine (1.21 g, 7.58 mmol, 1.00 eq) was added dropwise thereto and stirred at room temperature. After 1.5 hours, the mixture was cooled with water, and saturated aqueous sodium bicarbonate solution (10 mL) was slowly added thereto to neutralize the mixture. The solid was then suction filtered and washed with water. The residue was suspended in 1,2-dichloroethane (10 mL), and the solid was then suction filtered and washed with 1,2-dichloroethane to obtain 1.67 g (5.48 mmol, yield=72.3%) of a white solid as 2-(2H-benzo[d][1,2,3]triazol-2-yl)-6-bromo-4-methylphenol (hereinafter referred to as "UV-2 intermediate"). Under an argon atmosphere, UV-2 intermediate (0.379 g, 1.25 mmol, 1.92 eq), potassium thioacetate (0.074 g, 0.648 mmol, 1.00 eq), DPPF (0.0428 g, 0.077 mmol, 0.12 eq), and Pd ２ (dba) ３ The crude toluene solution was adsorbed onto a silica gel column (φ=2 cm column tube, 40 g of silica gel) and then purified by column chromatography using a 1 / 1 toluene / hexane mixed solvent to obtain 0.0972 g of a pale yellow solid known as 6,6-thiobis(2-(2H-benzo[d][1,2,3]triazol-2-yl)-4-methylphenol) (hereinafter referred to as "UV-2") (0.202 mmol, yield=31.2%).

[0090] The mass spectrum of the obtained compound (UV-2) is as follows: MALDI-MS (pos. CHCA) [M / H]+m / z 481.148 [M / Na]+m / z 503.149 [M / K]+m / z 519.132

[0091] The NMR of the obtained compound (UV-2) is as follows: １ H-NMR (CDCl ３ 500MHz): δ2.35(s, 6H, -CH ３ ), 7.16 (d, 2H), 7.47-7.51 (m, 4H), 7.91-7.95 (m, 4H), 8.18-8.19 (m, 2H), 11.78 (s, 2H, -OH)

[0092] The 5% weight loss temperature of the obtained compound (UV-2) measured with a differential scanning calorimeter (heating rate: 10°C / min) was 397°C, demonstrating extremely high heat resistance that contributes to the reduction of mold deposits. The 5% weight loss temperature of UV-2 was 237°C.

[0093] <Synthesis Comparative Example 3: Synthesis of UV-5> UV-5 was synthesized according to Synthesis Example 1 described in paragraphs 0213 to 0215 of WO 2020 / 137819.

[0094] <Raw Materials> Table 1 shows the raw materials used in Examples 1 to 13 and Comparative Examples 1 to 3. UV-1 UV-2 UV-3 UV-4 UV-5

[0095] Examples 1 to 13, Comparative Examples 1 to 3 Compounds The components listed in Table 1 were blended in the proportions (unit: parts by mass) listed in Table 2 (UV-1 was the compound obtained in Synthesis Example 2), and the mixture was uniformly mixed in a tumbler mixer to obtain a mixture. This mixture was fed to a single-screw extruder "VS40-32V" manufactured by Tanabe Plastics Machinery Co., Ltd., and kneaded under conditions of a screw rotation speed of 80 rpm, a discharge rate of 20 kg / hr, and a barrel temperature of 250°C, and extruded in the form of strands from the tip of the extrusion nozzle. The extrudate was quenched in a water bath and cut and pelletized using a pelletizer to obtain pellets of the resin composition.

[0096] <Measurement of Light Transmittance> Polycarbonate resin, PMMA-1, and each resin composition (pellet) obtained above were dried in a hot air circulation dryer at 120°C for 4 to 8 hours, and PMMA-2 was dried at 80°C for 4 hours, and then molded into a 3 mm thick molded article at a temperature of 280°C using an injection molding machine (FANUC Corporation "S-2000i 150B"). The molded article obtained above was used as a test piece, and using a haze meter (NDH4000) manufactured by Nippon Denshoku Industries Co., Ltd., the total light transmittance and the light transmittance at wavelengths of 400 nm and 420 nm were measured using a D65 light source in accordance with ASTM-D1003, and evaluated as follows. (1) Transparency Evaluation Total Light Transmittance A: 90% or more B: More than 88% but less than 90%

[0097] (2) Blue light blocking performance evaluation Light transmittance in the blue light wavelength range (400 nm and 420 nm) A: 5% or less B: More than 5% and less than 25% C: More than 25% and less than 50% D: More than 50% and less than 80% E: More than 80%

[0098] <Measurement of YI> Pellets of each resin composition obtained above were dried at 100°C for 5 hours, and then injection-molded into flat test pieces (90mm x 50mm x 3mm thick) using an injection molding machine ("J55-60H" manufactured by The Japan Steel Works, Ltd.) at a cylinder set temperature of 280°C, a mold temperature of 80°C, a screw rotation speed of 100 rpm, and an injection speed of 100mm / s. The obtained flat test pieces were measured for YI (Yellow Index) at 23°C using a spectrophotometer in accordance with JIS K 7373:2006, and evaluated as follows. The spectrophotometer used was an SE-2000 spectrophotometer manufactured by Nippon Denshoku Industries Co., Ltd. <<Yellowness Index Evaluation>> A: 5 or less B: More than 5 and 15 or less C: More than 15 and 20 or less D: More than 20

[0099] <Mold deposits> Five experts visually inspected the mold deposits that occurred during the manufacture of the test pieces when measuring the light transmittance, and evaluated them as follows, and decided by majority vote: A: No mold deposits were observed B: Slight mold deposits were observed C: Mold deposits were observed

[0100]

[0101] As is clear from the above results, when the ultraviolet absorber of the present invention was used, the light transmittance at a wavelength of 400 nm was very low and mold deposits were effectively suppressed (Examples 1 to 13). In particular, when the compound represented by formula (1) was used as the ultraviolet absorber, the light transmittance at a wavelength of 420 nm was also reduced. On the other hand, when the compound represented by formula (2) was used, light at a wavelength of 420 nm was effectively transmitted and sharp wavelength selectivity was achieved. Furthermore, the addition of a stabilizer or an acrylic resin component increased the total light transmittance and improved transparency. On the other hand, when the ultraviolet absorber of the comparative example was used, light at a wavelength of 400 nm could not be sufficiently blocked and mold deposits were poor (Comparative Examples 1 to 3).

Claims

1. An ultraviolet absorber containing a compound represented by formula (1) and / or a compound represented by formula (2). (In formula (1) and formula (2), each R is independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group. Each n is independently an integer of 0 to 4.) 2. An ultraviolet absorber containing the compound represented by formula (1). (In formula (1), each R independently represents a hydrocarbon group having 1 to 12 carbon atoms, a halogen atom, or a hydroxyl group, which may be substituted with a halogen atom and / or a hydroxyl group. Each n independently represents an integer of 0 to 4.) 3. In formula (1), at least one of Rs is a hydrocarbon group having 1 to 3 carbon atoms which may be substituted with a halogen atom and / or a hydroxyl group, a halogen atom, or a hydroxyl group. The ultraviolet absorber according to claim 2.

4. In formula (1), at least one of Rs is a methyl group. The ultraviolet absorber according to claim 2.

5. An ultraviolet absorber containing a compound represented by formula (3) or a compound represented by formula (4). (In formula (3), t-Bu represents a tert-butyl group.) 6. An ultraviolet absorber containing a compound represented by formula (3) and a compound represented by formula (4). (In formula (3), t-Bu represents a tert-butyl group.) 7. A resin composition comprising a thermoplastic resin and the ultraviolet absorber according to any one of claims 1 to 6.

8. The resin composition according to claim 7, wherein the total light transmittance when the thermoplastic resin is formed into a test piece having a thickness of 3 mm is 85% or more.

9. The resin composition according to claim 7, wherein the thermoplastic resin contains a polycarbonate resin.

10. The resin composition according to claim 7, wherein the thermoplastic resin contains a polycarbonate resin and further contains a phosphorus-based stabilizer.

11. The resin composition according to claim 7, which contains 0.001 to 1 part by mass of the ultraviolet absorber with respect to 100 parts by mass of the thermoplastic resin.

12. The resin composition according to claim 7, wherein the light transmittance at a wavelength of 420 nm when the resin composition is formed into a test piece having a thickness of 3 mm is 25% or less.

13. The resin composition according to claim 7, wherein the total light transmittance when the thermoplastic resin is formed into a test piece having a thickness of 3 mm is 85% or more, the thermoplastic resin contains a polycarbonate resin, further contains a phosphorus-based stabilizer, contains 0.001 to 1 part by mass of the ultraviolet absorber with respect to 100 parts by mass of the thermoplastic resin, and the light transmittance at a wavelength of 420 nm when the resin composition is formed into a test piece having a thickness of 3 mm is 25% or less.

14. The resin composition according to claim 7, wherein the total light transmittance when the thermoplastic resin is formed into a test piece having a thickness of 3 mm is 85% or more, the thermoplastic resin contains a polycarbonate resin, further contains a phosphorus-based stabilizer, contains more than 0.05 part by mass and 1 part by mass or less of the ultraviolet absorber with respect to 100 parts by mass of the thermoplastic resin, and the light transmittance at a wavelength of 400 nm and the light transmittance at a wavelength of 420 nm when the resin composition is formed into a test piece having a thickness of 3 mm are 5% or less and 25% or less, respectively.

15. When the thermoplastic resin is formed into a test piece with a thickness of 3 mm, the total light transmittance is 85% or more, the thermoplastic resin contains a polycarbonate resin, further contains a phosphorus-based stabilizer, and contains 0.001 parts by mass or more and less than 0.3 parts by mass of the ultraviolet absorber with respect to 100 parts by mass of the thermoplastic resin. When the resin composition is formed into a test piece with a thickness of 3 mm, the light transmittance at a wavelength of 400 nm is 5% or less, the light transmittance at a wavelength of 420 nm is 50% or less, and YI (Yellow Index) is 20 or less. The resin composition according to claim 7.

16. The resin composition according to claim 13, wherein the ultraviolet absorber contains an ultraviolet absorber represented by the formula (3). (In the formula (3), t-Bu represents a tert-butyl group.) 17. Pellets formed from the resin composition according to claim 7.

18. A molded article formed from the resin composition according to claim 7.

19. Pellets formed from the resin composition according to claim 16.

20. A molded article formed from the resin composition according to claim 16.

21. The compound represented by formula (3). (In formula (3), t-Bu represents a tert-butyl group.) 22. A method for producing a compound represented by formula (1-1), comprising heating a compound represented by formula (5-1) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-1), R １ is each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. n is an integer of 0 to 4. Hr is a halogen atom.) (In formula (1-1), R １ is each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. n is each independently an integer of 0 to 4.) 23. The method for producing a compound represented by the formula (1-1) according to claim 22, wherein the sulfidizing agent is prepared from a mercaptoalkanoic acid and an alkali metal hydride.

24. A method for producing a compound represented by formula (3), comprising heating a compound represented by formula (5-1-1) with potassium thioacetate and / or disodium mercaptopropionate in the presence of an organic solvent. (In formula (5-1-1) and formula (3), t-Bu represents a tert-butyl group.) 25. A method for producing a compound represented by formula (2-1), comprising heating a compound represented by formula (5-2) and a sulfidizing agent in the presence of an organic solvent. (In formula (5-2), R １ is each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. n is an integer of 0 to 4. Hr is a halogen atom.) (In formula (2-1), R １ is each independently a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. n is each independently an integer of 0 to 4.) 26. The method for producing a compound represented by the formula (2-1) according to claim 25, wherein the sulfidizing agent is prepared from a mercaptoalkanoic acid and an alkali metal hydride.

27. A method for producing a compound represented by formula (4), comprising heating a compound represented by formula (5-2-1) with potassium thioacetate and / or disodium mercaptopropionate in the presence of an organic solvent.

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