Resin compositions, as well as resin molded articles, writing instruments, and cosmetic tools.

Abstract

This invention provides a resin molded product that offers flexibility in fragrance design, high dispersibility of fragrances, and retains its fragrance even when exposed to high-temperature environments during molding. The resulting molded product has long-lasting fragrance, suppressed degradation of resin performance, and is recyclable. [Solution] A resin composition is provided in which a specific fragrance-encapsulating nanoparticle is blended into a base resin. Specifically, the base resin is blended with fragrance-encapsulating nanoparticles in which a fragrance is encapsulated in a reaction product of a monomer containing a (meth)acrylic acid ester represented by the following general formula (I). [Formula 1] TIFF2026059897000006.tif18143

Description

Technical Field

[0001] The present invention relates to a resin composition, a resin molded body, a writing instrument, and a cosmetic implement.

Background Art

[0002] Conventionally, as a technique for obtaining a resin having aromaticity, the permeability of the resin used as a base material has been studied (see Patent Document 1). Specifically, in a molded body made from a resin composition in which a fragrance is blended with a resin having low gas permeability, the fragrance components were encapsulated in the resin, and the volatilization of the fragrance hardly occurred. On the other hand, in the case of a resin composition in which a fragrance is blended with a resin having excellent gas permeability, although the volatilization of the fragrance is easy, it has been difficult to adjust the volatilization of the fragrance due to high heat treatment during molding and the volatilization rate of the fragrance after molding.

[0003] Therefore, in Patent Document 1, an aromatic powder is prepared by supporting a compounded fragrance mainly composed of a single fragrance having a vapor pressure of 200 μHg or less on a porous powder having a specific structure, and a resin composition in which this aromatic powder is blended with a thermoplastic resin having good gas permeability has been proposed.

[0004] Further, Patent Document 2 discloses a resin composition in which a fragrance is supported on at least one fragrance carrier selected from starch, dextrin, and Japanese wax, and then the carrier on which the fragrance is supported is added to a thermoplastic resin.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the resin composition described in Patent Document 1 had limitations on the vapor pressure of the fragrances that could be used, thus limiting the range of fragrances. Furthermore, because porous calcium silicate powder was used as the carrier, recycling of the resin composition was difficult.

[0007] Furthermore, the resin composition described in Patent Document 2 required the incorporation of a large amount of carrier supporting the fragrance in order to maintain the scent, which affected the inherent physical properties of the resin. In addition, the dispersibility of the fragrance was insufficient, leading to problems such as the fragrance bleeding out onto the surface of the molded article.

[0008] The present invention has been made in view of the above, and aims to provide a resin molded product that offers flexibility in fragrance design, high dispersibility of fragrances, does not lose its fragrance even when exposed to high-temperature environments during molding, has long-lasting fragrance, suppresses deterioration of resin performance, and does not impede recyclability. [Means for solving the problem]

[0009] The inventors diligently conducted research to achieve the above objectives. They discovered that the above problems could be solved by using a resin composition in which specific fragrance-encapsulating nanoparticles are blended into a base resin, and thus completed the present invention.

[0010] In other words, the present invention includes the following embodiments.

[0011] It contains a base resin and fragrance-encapsulating nanoparticles. The aforementioned fragrance-encapsulated nanoparticles are those in which a fragrance compound is encapsulated within a polymer. The polymer is a reaction product of monomers containing a (meth)acrylic acid ester represented by the following general formula (I). Resin composition. [ka] (In formula (I) above, A is a hydrogen atom or a methyl group, and R is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a group having a polyalkylene glycol chain having 2 to 18 carbon atoms in the alkylene chain. The alkyl group or the group having a polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, an alkoxy group having 1 to 18 carbon atoms, a perfluoroalkyl group having 1 to 18 carbon atoms, or a trialkoxysilyl group as a substituent.)

[0012] The fragrance compound content in the above-mentioned fragrance-encapsulated nanoparticles is preferably 1% by mass or more relative to 100% by mass of the polymer.

[0013] The average primary particle size of the above-mentioned fragrance-encapsulated nanoparticles is preferably between 20 nm and 800 nm.

[0014] The content of fragrance-encapsulated nanoparticles in the resin composition of the present invention is preferably 0.1% by mass or more and 10% by mass or less of the total resin composition.

[0015] The base resin is preferably one that has a melting point or softening point of 200°C or lower.

[0016] The base resin is preferably at least one selected from the group consisting of polypropylene, polyethylene, polylactic acid, olefin-based elastomers, and styrene-based elastomers.

[0017] Another aspect of the present invention is a resin molded article obtained from the resin composition of the present invention described above.

[0018] Another aspect of the present invention is a writing instrument obtained from the resin composition of the present invention described above.

[0019] Another aspect of the present invention is a cosmetic tool obtained from the resin composition of the present invention described above. [Effects of the Invention]

[0020] The resin composition of the present invention has a high degree of freedom in fragrance design, has high dispersibility of the fragrance, and does not lose its fragrance even when exposed to a high-temperature environment during molding. Further, the molded product obtained from the resin composition of the present invention has fragrance persistence, suppression of deterioration of resin performance, and no problem in recyclability.

Mode for Carrying Out the Invention

[0021] ≪Resin Composition≫ The resin composition of the present disclosure contains a base resin and fragrance-encapsulating nanoparticles. Hereinafter, the components of the resin composition will be described respectively.

[0022] <Fragrance-encapsulating Nanoparticles> The fragrance-encapsulating nanoparticles used in the resin composition of the present disclosure are nanoparticles on the nanoscale in which a fragrance compound is encapsulated in a polymer. Note that the fragrance-encapsulating nanoparticles only need to be those in which at least the fragrance compound is encapsulated in the polymer, and optionally, substances other than the fragrance compound may be encapsulated in the polymer together with the fragrance compound. Examples of substances other than the fragrance compound include preservative components, antibacterial components, reducing components, and the like.

[0023] [Polymer] ((Meth)acrylate) In the fragrance-encapsulating nanoparticles, the polymer encapsulating the fragrance compound is a reaction product of a monomer containing a (meth)acrylate represented by the following general formula (I).

Chemical Formula

[0024] In this specification, the term "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid."

[0025] Since the polymer encapsulating the fragrance compound is a reaction product of monomers containing (meth)acrylic acid ester represented by the above general formula (I), the fragrance components that can be encapsulated can be used without limitation, providing flexibility in fragrance design. Furthermore, it is possible to obtain particles with a long-lasting fragrance and stability, and when formed into a resin composition, it is possible to achieve fragrance persistence. Moreover, because the fragrance compound is encapsulated in a polymer that is a reaction product of monomers containing (meth)acrylic acid ester represented by the above general formula (I), even when the resin composition containing fragrance-encapsulated nanoparticles is exposed to high-temperature environments for molding or other purposes, fragrance loss can be suppressed.

[0026] In formula (I) above, R is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a group having a polyalkylene glycol chain having 2 to 18 carbon atoms in the alkylene chain. The alkyl group or the group having a polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, an alkoxy group having 1 to 18 carbon atoms, a perfluoroalkyl group having 1 to 18 carbon atoms, or a trialkoxysilyl group as a substituent.

[0027] Examples of C1-C22 alkyl groups that form R in formula (I) above include C1-C20 linear or branched alkyl groups, C3-C10 cycloalkyl groups, and C1-C18 alkyl groups that may have an epoxy group, a hydroxyl group, a dialkylamino group, or a C1-C4 alkoxy group as a substituent.

[0028] Among these, the C1-C22 alkyl group that becomes R in formula (I) above is preferably an alkyl group having C1-C6, which may have an epoxy group, a hydroxyl group, or an alkoxy group having C1-C2 as a substituent, and most preferably an alkyl group having C1-C6, which may have an epoxy group as a substituent.

[0029] Specific examples of (meth)acrylic acid esters represented by general formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, and behemopropyl (meth)acrylate. Nyl, (meth)acrylate cyclohexyl, (meth)acrylate phenyl, (meth)acrylate benzyl, (meth)acrylate isobornyl, (meth)acrylate glycidyl, (meth)acrylate tetrahydrofurfuryl, (meth)acrylate allyl, (meth)acrylate 2-hydroxyethyl, (meth)acrylate hydroxypropyl, (meth)acrylate 2-methoxyethyl, (meth)acrylate 2-ethoxyethyl, (meth)acrylate dimethylaminoethyl, (meth)acrylate diethylaminoethyl, di(meth)acrylate Examples include ethylene glycol acrylate, triethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 2-(meth)acroyloxyethyl phthalate, 2-(meth)acroyloxyethyl hexahydrophthalate, trifluoroethyl (meth)acrylate, butoxyethyl (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, diethylene glycol (meth)acrylate, 2-(dimethylamino)ethyl (meth)acrylate, 2-(dimethylamino)propyl (meth)acrylate, 2-(dimethylamino)butyl (meth)acrylate, 2-(acetoacetoxy)ethyl (meth)acrylate, perfluoroethyl methacrylate having perfluoroalkyl groups of 1 to 18 carbon atoms, trialkoxysilylpropyl (meth)acrylate, dialkoxymethylsilylpropyl (meth)acrylate, etc. (Meth)acrylic acid esters represented by general formula (I) may be used alone or in combination of two or more types.

[0030] Among these, at least one selected from the group consisting of (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, or (meth)acrylate, is preferable, due to its ease of industrial availability, ease of handling and safety during the production of fragrance-encapsulated nanoparticles, and further improvement of the effects of the present invention.

[0031] ((meth)acrylic acid ester content) In polymers containing fragrance compounds, the content of the portion derived from the above-mentioned (meth)acrylic acid ester is preferably 30% by mass or more relative to the total amount of the polymer containing the fragrance compound. If the content of the portion derived from the above-mentioned (meth)acrylic acid ester is 30% by mass or more, the resulting fragrance-encapsulated nanoparticles will have sufficient stability over time.

[0032] The content of the portion derived from the above (meth)acrylic acid ester is more preferably 30 to 95% by mass, and particularly preferably 30 to 70% by mass.

[0033] In this invention, "total amount of polymer containing fragrance compound" means the total mass of the polymer containing the fragrance compound, and specifically means the total mass of (meth)acrylic acid ester for forming the polymer, other monomer components used optionally, and crosslinking agents and additives used as needed.

[0034] (Other monomers) In fragrance-encapsulating nanoparticles, the polymer encapsulating the fragrance may contain other monomers besides the (meth)acrylic acid ester represented by the above general formula (I). Other monomers that can provide a more sustained fragrance include, for example, hydrophobic vinyl monomers other than the (meth)acrylic acid ester monomer, and aqueous monomers.

[0035] Examples of hydrophobic vinyl monomers include styrene, methylstyrene, chloromethylstyrene, alkylstyrene having alkyl groups with 1 to 12 carbon atoms, methoxystyrene, chlorostyrene, bromostyrene, divinylbenzene, phenylstyrene, and vinylnaphthalene. The hydrophobic vinyl monomer used may be used alone or in combination of two or more types.

[0036] Examples of aqueous monomers include glycerin monomethacrylate, sodium 2-sulfoethyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polyethylene glycol-propylene glycol monomethacrylate, polyethylene glycol-tetramethylene glycol-monomethacrylate, and propylene glycol-polybutylene glycol-monomethacrylate. The aqueous monomers used may be used individually or in combination of two or more.

[0037] (Content of other monomers) In fragrance-encapsulated nanoparticles, the content of the portion derived from monomers other than (meth)acrylic acid esters in the polymer encapsulating the fragrance compound is preferably 0.5 to 70% by mass relative to the total amount of the polymer. If the content of the portion derived from monomers other than (meth)acrylic acid esters is 0.5 to 70% by mass relative to the total amount of the polymer, the effects of the present invention can be fully expressed, and the moldability, dispersibility, bleed-out properties, maintenance of resin performance, and recyclability of the resulting fragrance-encapsulated nanoparticle resin composition can be improved.

[0038] [Fragrance compounds] In fragrance-encapsulated nanoparticles, the fragrance compound encapsulated within the polymer is not particularly limited. The fragrance compound used in the fragrance-encapsulated nanoparticles may be used alone or in combination of two or more types.

[0039] The fragrance compound may be either a natural fragrance or a synthetic fragrance, or a mixture thereof. Furthermore, fragrance components described in, for example, "Synthetic Fragrances: Chemistry and Product Knowledge" (by Motoichi Indo, Chemical Daily Co., Ltd.) may be included to the extent that they do not interfere with the effects of the present invention.

[0040] Furthermore, due to the ease with which the fragrance compound can be encapsulated in the polymer containing the fragrance compound, its solubility in water is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less.

[0041] The fragrance compound used in the fragrance-encapsulated nanoparticles is preferably at least one selected from group A below. A fragrance compound selected from group A has a strong residual fragrance, is readily available, is easy and safe to handle during the production of the fragrance-encapsulated nanoparticles, and furthermore, can more effectively exhibit the effects of the present invention. [Group A] Borneol, eugenol, 4-terpinenol, 1,8-cineole, d-limonene, citral, geraniol, vanillin, 2-phenylethanol, γ-decalactone, linalool, L-perillaldehyde, raspberry ketone, DL-camphor, L-carbyl acetate, alliophyllene, L-citronellol, D-dihydrocarbeol, L-dihydrocarbeol, dihydroterpineol, dihydroterpineol acetate, linalool oxide, myrtenyl acetate, allyl isothiocyanate, L-carbeol, caryophyllene oxide, 1,4-cineole, p-cymene, D-dihydrocarbone, L-dihydrocarbone, D-dihydrocarbyl acetate, L-dihydrocarbyl acetate, elemene, Isobornyl acetate, L-limonene, D-limonene oxide, L-limonene oxide, p-menthane, L-menthol, menthone, myrtenal, myrtenol, 3-octyl acetate, L-periryl alcohol, L-periryl acetate, α-pinene, β-pinene, D-pulegone, α-terpinene, terpineol C, α-terpineol, L-α-terpineol, terpineol-4, terpinolene, α-terpinyl acetate, verbenol, verbenone, 3-carene, carene oxide, hexyl acetate, nerol, ethyl safranate, acetyl eugenol, chavicol, estragol, anethole, manzanate, γ-terpinene, cymene, myrcene, phellandrene, farnesene, and thujene.

[0042] The fragrance compound used in the fragrance-encapsulated nanoparticles is more preferably at least one selected from group B within group A. If a fragrance compound is selected from group B, the stability over time, ease of handling during the manufacture of the fragrance-encapsulated nanoparticles, and safety can be further improved. [Group B] Borneol, eugenol, 4-terpinenol, 1,8-cineole, d-limonene, citral, geraniol, vanillin, 2-phenylethanol, γ-decalactone, linalool, L-perillaldehyde, DL-camphor, L-carbyl acetate, alliophyllene, L-citronellol, linalool oxide, myrtenyl acetate, allyl isothiocyanate, 1,4-cineole, isobol Lunyl acetate, L-limonene, L-menthol, 3-octyl acetate, L-periryl alcohol, L-periryl acetate, α-pinene, β-pinene, α-terpinene, terpineol-4, nerol, ethyl safranate, acetyl eugenol, chavicol, estragole, anethole, manzanate, γ-terpinene, cymene, myrcene, phellandrene, farnesene, and thujene.

[0043] The fragrance compound used in the fragrance-encapsulated nanoparticles is preferably at least one selected from group C within group A. If a fragrance compound is selected from group C, the stability over time, ease of handling during the manufacture of the fragrance-encapsulated nanoparticles, and safety can be further improved. [Group C] The above fragrance compounds are d-limonene, 2-phenylethanol, citral, linalool, linalool oxide, eugenol, γ-decalactone, 1,8-cineole, γ-terpinene, cymene, myrcene, phellandrene, farnesene, and thugen.

[0044] Furthermore, in addition to the fragrance compounds selected from Group A described above, fragrance compounds other than those in Group A may also be included. Examples of fragrance compounds other than those in Group A include terpene fragrance compounds, alcohol fragrance compounds, hydrocarbon fragrance compounds, phenolic fragrance compounds, ester fragrance compounds, carbonate fragrance compounds, aldehyde fragrance compounds, ketone fragrance compounds, acetal fragrance compounds, ether fragrance compounds, carboxylic acid fragrance compounds, lactone fragrance compounds, nitrile fragrance compounds, Schiff base fragrance compounds, natural essential oils, and natural extracts. Examples of fragrance compounds other than those in Group A are given below.

[0045] (Terpene fragrance compound) Examples of terpene fragrance compounds include monoterpenes having 10 carbon atoms and their derivatives (including compounds with 10 or more carbon atoms). Preferably, at least one is selected from the group consisting of terpene hydrocarbons, terpene alcohols, and terpene esters.

[0046] Here, monoterpenes are fragrance compounds consisting of 10 carbon atoms, each composed of two isoprene units, and include both linear (acyclic) compounds and cyclic compounds containing rings. In this invention, terpene fragrances also include terpene hydrocarbons, terpene alcohols, terpene esters, and terpene aldehydes.

[0047] The terpene fragrance compounds that can be used in the present invention are not particularly limited as long as they are fragrance compounds or derivatives thereof that have isoprene as a constituent unit, and can be appropriately selected according to the purpose. Examples of terpene fragrance compounds include linear monoterpenes such as ocimene, cosmene, citronellal, and citronellol; monocyclic monoterpenes such as terpinene, terpinolene, and cymene; and bicyclic monoterpenes such as camphene, carene, and sabinene.

[0048] Among terpene fragrance compounds, terpene hydrocarbons such as pinene, carene, terpinene, and camphene; terpene alcohols such as citronellol; terpene esters such as linalyl acetate, terpinyl acetate, geranyl acetate, neryl acetate, citronellyl acetate, and isobolonyl acetate; and terpene aldehydes such as citronellal, neral, and perillaldehyde are preferred.

[0049] (Alcohol-based fragrance compounds) Examples of alcohol-based fragrance compounds include aliphatic alcohol-based fragrance compounds, aromatic alcohol-based fragrance compounds, terpene-based alcohol-based fragrance compounds, and other alcohol-based fragrance compounds. Among these, aliphatic alcohol-based fragrance compounds are preferred.

[0050] Examples of aliphatic alcohol-based fragrance compounds include cis-3-hexenol, 1-(2,2,6-trimethylcyclohexyl)-3-hexanol, 2-methyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, ethylnorbonylcyclohexanol, 4-methyl-3-decen-5-ol, and isobornylcyclohexanol.

[0051] Examples of aromatic alcohol-based fragrance compounds include phenylethyl alcohol, benzyl alcohol, dimethylbenzylcarbinol, phenylethyldimethylcarbinol, and phenylhexanol.

[0052] Examples of terpene-alcohol-based fragrance compounds include α-terpineol and β-citronellol.

[0053] Other alcohol-based fragrance compounds include, for example, glycols such as dipropylene glycol, and 4-methyl-2-(2-methylpropyl)tetrahydro-2H-4-pyranol.

[0054] (Hydrogen-based fragrance compounds) Examples of hydrocarbon-based fragrance compounds include α-copaene, hydrogenated limonene dimer, isocaryophyllene, pinene dimer, dipentene dimer, and trimer.

[0055] (Phenol-based fragrance compounds) Examples of phenolic fragrance compounds include guaiacol, dihydroeugenol, isoeugenol, thymol, paracresol, and ethyl vanillin.

[0056] (Ester-based fragrance compounds) Examples of ester-based fragrance compounds include aliphatic carboxylic acid esters, aromatic carboxylic acid esters, and other carboxylic acid esters.

[0057] Examples of aliphatic carboxylic acids that form aliphatic carboxylic acid esters include linear and branched carboxylic acids having 1 to 18 carbon atoms. Among these, carboxylic acids having 1 to 6 carbon atoms, such as formic acid, acetic acid, propionic acid, decantic acid, valeric acid, and hexanoic acid, are preferred, with acetic acid being particularly preferred.

[0058] Aromatic carboxylic acids that form aromatic carboxylic acid esters include benzoic acid, cinnamic acid, salicylic acid, anthranilic acid, anisic acid, and phenylacetic acid.

[0059] Other carboxylic acids that form carboxylic acid esters include brassic acid, tiglic acid, jasmonic acid, glycidic acid, glycolic acid, and geranic acid.

[0060] Examples of alcohols that form aliphatic esters or aromatic esters include linear and branched aliphatic alcohols having 1 to 5 carbon atoms and the alcohol-based fragrance compounds mentioned above.

[0061] Preferred formic acid esters as aliphatic carboxylic acid esters include, for example, linalyl formate, citronellyl formate, and geranyl formate.

[0062] Preferred acetate esters as aliphatic carboxylic acid esters include, for example, ethyl acetate, isoamyl acetate (isopentyl acetate), cis-3-hexenyl acetate, linalyl acetate, citronellyl acetate, geranyl acetate, neryl acetate, terpinyl acetate, nopyl acetate, bornyl acetate, acetylisoeugenol, o-tert-butylcyclohexyl acetate, p-tert-butylcyclohexyl acetate, tricyclodecenyl acetate, benzyl acetate, phenylethyl acetate, styraryl acetate, cinnamyl acetate, dimethylbenzylcarbyl acetate, phenylethylphenyl acetate, 3-pentyltetrahydropyran-4-yl acetate, and paracresylphenyl acetate.

[0063] Preferred propionic acid esters as aliphatic carboxylic acid esters include, for example, citronellyl propionate, tricyclodecenyl propionate, allylcyclohexyl propionate, ethyl 2-cyclohexyl propionate, benzyl propionate, and styraryl propionate.

[0064] Preferred butyric acid esters as aliphatic carboxylic acid esters include, for example, citronellyl butyrate, dimethylbenzylcarbin n-butyrate, and tricyclodecenyl isobutyrate.

[0065] Preferred valeric acid esters as aliphatic carboxylic acid esters include, for example, methyl valerate, ethyl valerate, butyl valerate, amyl valerate, benzyl valerate, and phenylethyl valerate, while preferred hexanoic acid esters include, for example, methyl hexanoate, ethyl hexanoate, allyl hexanoate, linalyl hexanoate, and citronellyl hexanoate.

[0066] Other aliphatic carboxylic acid esters include, as heptanoic acid esters, methylheptanoate and allylheptanoate, and as nonenic acid esters, methyl 2-nonenoate, ethyl 2-nonenoate, and ethyl 3-nonenoate, among others.

[0067] Examples of aromatic carboxylic acid esters, such as benzoic acid esters, include methyl benzoate, benzyl benzoate, and 3,6-dimethyl benzoate. Examples of cinnamic acid esters include methyl cinnamate and benzyl cinnamate.

[0068] Examples of salicylic acid esters, which are aromatic carboxylic acid esters, include methyl salicylate, n-hexyl salicylate, cis-3-hexenyl salicylate, cyclohexyl salicylate, and benzyl salicylate.

[0069] Examples of anthranilic acid esters, which are aromatic carboxylic acid esters, include methyl anthranilate, ethyl anthranilate, and dimethyl anthranilate.

[0070] Other carboxylic acid esters include brassic acid esters such as ethylene brassirate. Examples of tigric acid esters include geranyl tigrate, 1-hexyl tigrate, and cis-3-hexenyl tigrate. Examples of jasmonic acid esters include methyl jasmonate and methyl dihydro jasmonate. Examples of glycidic acid esters include methyl 2,4-dihydroxy-ethylmethylphenylglycidate and 4-methylphenylethylglycidate. Examples of glycolic acid esters include allylcyclohexyl glycolate. Others include ethyl tricyclo[5.2.1.0 2.6 Examples include decane-2-carboxylate (trade name Frutate, Kao Corporation).

[0071] (Carbonate-based fragrance compounds) Examples of carbonate-based fragrance compounds include cis-3-hexenylmethyl carbonate, methyl-cyclooctyl carbonate, and ethyl-2-t-butylcyclohexyl carbonate.

[0072] (Aldehyde-based fragrance compounds) Examples of aldehyde-based fragrance compounds include n-octanal, n-nonanal, n-decanal, n-dodecanal, 2-methylundecanal, 10-undecenal, citronellal, hydroxycitronellal, 2,4-dimethyl-3-cyclohexenyl-1-carboxyaldehyde, dimethyl-3-cyclohexenyl-1-carboxyaldehyde, benzaldehyde, phenylacetaldehyde, phenylpropylaldehyde, cinnamicaldehyde, dimethyltetrahydrobenzaldehyde, and 3-(4-tert-butylphenyl) Examples include ropanal, hydroxymylacaldehyde, 2-cyclohexylpropanal, p-tert-butyl-α-methylhydrocinnamicaldehyde, p-isopropyl-α-methylhydrocinnamicaldehyde, 3-(o-(and p-)ethylphenyl)-2,2-dimethylpropionaldehyde, α-amylcinnamicaldehyde, α-hexylcinnamicaldehyde, heliotropin, alpha-methyl-1,3-benzodioxol-5-propanal, and 2-methyl-3-(paramethoxyphenyl)propanal.

[0073] (Ketone-based fragrance compounds) Examples of ketone fragrance compounds include methylheptenone, dimethyloctenone, 3-octanone, hexylcyclopentanone, dihydrojasmone, 2,2,5-trimethyl-5-pentylcyclopentanone, 2-(2-(4-methyl-3-cyclohexen-1-yl)propyl)cyclopentanone, ionone, β-ionone, methylionone, methylionone-G, γ-methylionone, damascone, α-damascone, β-damascone, δ-damascone, 1-(2,4,4-trimethyl-2-cyclohexyl)-trans-2-butanone, damascenone, 1-(5,5-dimethyl-1-cyclohexen-1-yl)-4-penten-1-one, ylone, 1,2,3,5,6,7-hexahydro-1,1,2,3,3-penta Examples include methyl-4H-inden-4-one, 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-ethane-1-one, 7-methyl-3,4-dihydro-2H-benzodioxepin-3-one, carvone, acetylcedrene, isolongiforanone, nootkatone, benzylacetone, benzophenone, 6-acetyl-1,1,2,4,4,7-hexamethyltetrahydronaphthalene, β-methylnaphthylketone, ethylmaltol, camphor, muscone, 3-methyl-5-cyclopentadecene-1-one, cibetone, 8-cyclohexadecenonone, methylnonylketone, cis-jasmon, paraamylcyclohexanone (4-pentylcyclohexanone), etc.

[0074] (Acetal fragrance compound) Examples of acetal-based fragrance compounds include acetaldehyde ethylphenylpropyl acetal, citral diethyl acetal, phenylacetaldehyde glyceryl acetal, and ethyl acetacetate ethylene glycol acetal.

[0075] (Ether-based fragrance compounds) Examples of ether-based fragrance compounds include ethyl linalool, cedyl methyl ether, β-naphthyl methyl ether, β-naphthyl ethyl ether, rose oxide, nerol oxide, rose furan, [3aR-(3aα,5aβ,9aα,9bβ)] dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]furan, 3,3,5-trimethylcyclohexyl ethyl ether, hexamethylhexahydrocyclopentabenzopyran, and phenylacetaldehyde dimethyl acetal.

[0076] (Carboxylic acid-based fragrance compounds) Examples of carboxylic acid-based fragrance compounds include benzoic acid, phenylacetic acid, cinnamic acid, hydrocinnamic acid, butyric acid, and 2-hexenoic acid.

[0077] (Lactone-based fragrance compounds) Examples of lactone-based fragrance compounds include ambrettelide, δ-decalactone, γ-valerolactone, γ-nonalactone, γ-undecalactone, δ-hexalactone, γ-jasmolactone, whiskey lactone, coumarin, cyclopentadecanolide, cyclohexadecanolide, 11-oxahexadecanolide, and butylidenephthalide.

[0078] (Nitrile-based fragrance compounds) Examples of nitrile-based fragrance compounds include tridecene-2-nitrile, geranylnitrile, citronellylnitrile, and dodecanenitrile.

[0079] (Schiff base fragrance compounds) Examples of Schiff base-based fragrance compounds include aurantiol and ligantral.

[0080] (Natural essential oils and natural extracts) Examples of natural essential oils and extracts include orange, lemon, lime, bergamot, vanilla, mandarin, peppermint, spearmint, lavender, chamomile, rosemary, eucalyptus, sage, basil, rose, rock rose, geranium, jasmine, ylang-ylang, anise, clove, ginger, nutmeg, cardamom, cedar, cypress, vetiver, patchouli, lemongrass, labdanum, grapefruit, and elemi oil.

[0081] [Optional component] The fragrance-encapsulating nanoparticles may optionally contain substances other than the fragrance compound encapsulated together with the fragrance compound in the polymer. Examples of optional components include preservatives, antibacterial agents, and reducing agents.

[0082] (Preservative ingredients, antibacterial ingredients) Examples of preservative or antibacterial components include iodopropagyl compounds, 1,2-benzoisothiazolin-3-one, 2,3,5,6-tetrachloro-4(methylsulfonyl)pyridine, sodium benzoate, sodium dehydroacetate, potassium sorbate, methylisothiazolinone, chloromethylisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone, hexahydro-1,3,5-tris(2-hydroxyethyl)-1,3,5-triazine, 2-bromo-2-nitropropane-1,3-diol, and 2-pyridinethiol-1-oxidesodium Examples include sodium pyrithione, 2-(4-thiozolyl)benzimidazole, diisothiocyanate, isopropylmethylphenol, 2-methyl-4-isothiazolin-3-one, tannic acid, ethylparaben, benzalkonium chloride, glycerin fatty acid ester, ethyl parahydroxybenzoate, butyl parahydroxybenzoate, propyl parahydroxybenzoate, methyl parahydroxybenzoate, hinokitiol, phenoxyethanol, butylparaben, propylparaben, benzalkonium chloride, methylparaben, and 2-(4-thiazolyl)benzimidazoleparaben.

[0083] (Content of fragrance compounds) The content of the fragrance compound is preferably 1% by mass or more relative to 100% by mass of the polymer containing the fragrance compound. If the content of the fragrance compound is 1% by mass or more, the resulting fragrance-encapsulated nanoparticles will have sufficient fragrance performance and will exhibit a sustained lingering fragrance effect.

[0084] The content of the fragrance compound is more preferably 5% by mass or more, more preferably 10 to 50% by mass, and particularly preferably 15 to 40% by mass, based on 100% by mass of the polymer containing the fragrance compound.

[0085] (Average primary particle size) The average primary particle size of the fragrance-encapsulated nanoparticles is preferably 20 nm to 800 nm or less. If the average primary particle size of the fragrance-encapsulated nanoparticles is between 20 nm and 800 nm, the dispersibility in the base resin is excellent when the fragrance-encapsulated nanoparticles are dispersed in the base resin to form a resin composition.

[0086] The average primary particle size of the fragrance-encapsulating nanoparticles is more preferably 20 to 300 nm, even more preferably 30 to 200 nm, and particularly preferably 30 to 150 nm.

[0087] In this specification, "average primary particle size" refers to the histogram-average particle diameter based on the scattered light intensity distribution. In this specification (including the examples described later), it refers to the value D50 measured using a particle size distribution analyzer [FPAR1000 (manufactured by Otsuka Electronics Co., Ltd.)].

[0088] (Content of fragrance-encapsulated nanoparticles in the resin composition) The content of fragrance-encapsulated nanoparticles in the resin composition of the present invention is preferably 0.1% by mass or more and 10% by mass or less of the total resin composition. If the content of fragrance-encapsulated nanoparticles in the resin composition is less than 0.1% by mass, it becomes difficult to exhibit the effects of the present invention. On the other hand, if the content of fragrance-encapsulated nanoparticles in the resin composition exceeds 10% by mass, the resin performance of the composition deteriorates, and its recyclability is also impaired.

[0089] (Method for manufacturing fragrance-encapsulated nanoparticles) The method for producing fragrance-encapsulated nanoparticles used in the resin composition of the present invention is not particularly limited, but for example, one method is to dissolve at least one fragrance compound in a solvent containing at least the above-mentioned (meth)acrylic acid ester as a monomer and perform emulsion polymerization. Alternatively, one method is to copolymerize a mixed monomer containing at least the above-mentioned (meth)acrylic acid ester monomer and other monomer components, and then dissolve at least one fragrance compound and perform emulsion polymerization. By emulsion polymerization, fragrance-encapsulated nanoparticles in which the fragrance compound is encapsulated in the polymer are produced, and a dispersion (dispersion liquid) in which the fragrance-encapsulated nanoparticles are dispersed can be obtained.

[0090] Subsequently, the dispersion (dispersion liquid) in which the fragrance-encapsulated nanoparticles are dispersed is dried to obtain a powder of fragrance-encapsulated nanoparticles.

[0091] More specifically, for example, by dissolving the above-mentioned fragrance compound and optionally other substances in a monomer containing the above-mentioned (meth)acrylic acid ester, or a mixed monomer containing the above-mentioned (meth)acrylic acid ester monomer and other monomers, and using ammonium persulfate, potassium persulfate, hydrogen peroxide, etc. as polymerization initiators, or polymerization initiators further combined with a reducing agent, and then emulsion polymerization using a crosslinking agent and, if necessary, a polymerizable surfactant (emulsifier), a dispersion (dispersion liquid) in which fragrance-encapsulated nanoparticles are dispersed can be obtained. Subsequently, by drying and removing the medium from the dispersion (dispersion liquid) in which fragrance-encapsulated nanoparticles are dispersed, a powder of fragrance-encapsulated nanoparticles can be obtained.

[0092] Examples of crosslinking agents include triallyl isocyanurate, triallyl isocyanurate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, pentaerythritol acrylate, ditrimethylolpropane acrylate, dipentaerythritol acrylate, methoxylated bisphenol A methacrylate, pentaerythritol methacrylate, ditrimethylolpropane methacrylate, dipentaerythritol methacrylate, and ethoxylated polyglycerin methacrylate.

[0093] Furthermore, using triallyl isocyanurate or the like as a crosslinking agent is preferable because it can improve the heat resistance, mechanical properties, hydrolysis resistance, and weather resistance of the resulting fragrance-encapsulated nanoparticles.

[0094] Furthermore, polymerizable surfactants (emulsifiers) used as needed include polyoxyethylene-1-(allyloxymethyl)-alkyl ether sulfate ammonium, ether sulfate, polyoxyethylene nonylpropenylphenyl ether sulfate ammonium, polyoxyethylene nonylpropenylphenyl ether, polyacrylate ammonium, styrene-maleate copolymer ammonium, polyoxyethylene alkyl ether, polyoxyethylene styrene-phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyalkylene decyl ether, and polyoxyethylene tridecyl ether. Examples include alkylbenzene sulfonates, dioctyl sulfosuccinates, sodium lauryl sulfate, polyoxyethylene alkyl ether phosphates, polyoxyethylene styrene-phenyl ether phosphates, polyoxyethylene styrene-phenyl ether sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene sorbitan monolaurate (polysorbate 20), polyoxyethylene sorbitan palmitate (polysorbate 40), polyoxyethylene sorbitan monostearate (polysorbate 60), and polyoxyethylene sorbitan oleate (polysorbate 80).

[0095] The emulsion polymerization described above may also be carried out by further mixing an appropriate amount of dicyclopenta(thenyl)acrylate with the above-mentioned (meth)acrylic acid ester, etc. When dicyclopenta(thenyl)acrylate monomer is further mixed in during emulsion polymerization, the stability is less likely to be impaired even if the water in the dispersion evaporates.

[0096] Here, dicyclopentanyl(meth)acrylate includes dicyclopentanyl acrylate monomer, dicyclopentenyl acrylate, dicyclopentanyl methacrylate monomer, and dicyclopentenyl methacrylate.

[0097] Furthermore, during emulsion polymerization, in addition to the (meth)acrylic acid esters mentioned above, other hydrophobic vinyl monomers, and dicyclopenta(thenyl)acrylate, monomers having reactive crosslinking groups such as epoxy groups, hydroxymethylamide groups, and isocyanate groups, or polyfunctional monomers having two or more vinyl groups may be added in appropriate amounts for crosslinking.

[0098] <Base resin> The base resin used in the resin composition of this disclosure is not particularly limited. It can be appropriately selected and used depending on the application of the resin composition.

[0099] The base resin used in the resin composition of this disclosure preferably has a melting point or softening point of 200°C or lower. If the resin has a melting point or softening point of 200°C or lower, it is possible to suppress the volatilization of fragrance compounds from fragrance-encapsulating nanoparticles during molding.

[0100] Furthermore, it is preferable that the base resin used in the resin composition of this disclosure is at least one selected from the group consisting of polypropylene, polyethylene, polylactic acid, olefin-based elastomers, and styrene-based elastomers.

[0101] <Other ingredients> The resin compositions of this disclosure may contain other components, such as additives, to impart the necessary functions to molded articles obtained from the resin compositions. Examples of other components include additives such as pigments and dyes, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, plasticizers, flame retardants, and antistatic agents.

[0102] ≪Method for manufacturing resin compositions≫ The method for producing the resin composition of this disclosure is not particularly limited, and conventionally known methods can be applied. Examples of methods for producing the resin composition of this disclosure include melt-kneading using various general-purpose kneaders.

[0103] Examples of mixing machines include single-screw extruders, twin-screw extruders, roll mixers, Banbury mixers, and kneaders. The base resin and fragrance-encapsulated nanoparticles may be added to the mixing machine all at once and melt-mixed, or the base resin may be melted beforehand, and then the fragrance-encapsulated nanoparticles may be added and mixed.

[0104] Uses of resin compositions The resin compositions of this disclosure can be molded into resin articles by known molding methods. Examples of molding methods include, but are not limited to, injection molding, hot press molding, and blow molding.

[0105] Furthermore, resin molded articles obtained from the resin compositions of this disclosure can be applied to a variety of uses. Examples of applications for resin molded articles include, but are not limited to, automotive parts, household electrical appliance parts, household goods, packaging materials, and other general industrial materials.

[0106] Resin molded articles obtained from the resin compositions of this disclosure can be preferably used in writing instruments or cosmetic tools. [Examples]

[0107] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The term "parts" below refers to parts by mass.

[0108] <Manufacturing of fragrance-encapsulated nanoparticles> (Manufacturing Example 1) A stirrer, reflux condenser, thermometer, nitrogen gas inlet tube, and 1000 ml separatory funnel for monomer input were attached to a 2-liter flask and placed in a hot water bath. 352.5 parts distilled water, 5 parts glycerin monomethacrylate (Bremmer GLM, NOF Corporation), 5 parts sodium 2-sulfoethyl methacrylate (Acrylic Ester SEM-Na, Mitsubishi Chemical Corporation), 40 parts polymerizable surfactant (ADEKA Corporation, Adekarya Soap SR-10, ether sulfate), and 0.5 parts ammonium persulfate were charged into the flask, and the internal temperature was raised to 50°C while introducing nitrogen gas.

[0109] On the other hand, a solution was prepared by mixing a mixed monomer consisting of 50 parts cyclohexyl methacrylate and 20 parts n-butyl methacrylate with 17 parts d-limonene (manufactured by Nippon Terpene Chemical Co., Ltd.) as a fragrance compound and 10 parts crosslinking agent (trialyl isocyanurate, manufactured by Nippon Chemical Corporation, TAIC).

[0110] This prepared solution was added from the separatory funnel to the flask, which was kept at a temperature of approximately 50°C, under stirring for 3 hours to carry out emulsion polymerization. Subsequently, it was aged for 5 hours to complete the polymerization, obtaining a fragrance-encapsulated nanoparticle dispersion (dispersion) in which the fragrance was embedded within the polymer.

[0111] Subsequently, the obtained fragrance-encapsulated nanoparticle dispersion (dispersion liquid) was dried in a 50°C dryer for 24 hours to remove the dispersion medium, thereby obtaining fragrance-encapsulated nanoparticle powder (particle 1).

[0112] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 61.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 13.1% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 91 nm.

[0113] (Manufacturing example 2) In the above-described production example 1, the amount of distilled water was 349.5 parts, the amount of cyclohexyl methacrylate was 53 parts, the amount of n-butyl methacrylate was 17 parts, and 20 parts of 2-phenylethanol (2-phenylethyl alcohol) (manufactured by Inoue Fragrance Manufacturing Co., Ltd.) was used as the fragrance compound. Otherwise, the same procedure as in the above-described production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particle 2).

[0114] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 61.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 15.4% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 80 nm.

[0115] (Manufacturing Example 3) In the above-described manufacturing example 1, the amount of distilled water was 349.5 parts, the amount of cyclohexyl methacrylate was 55 parts, the amount of n-butyl methacrylate was 15 parts, and 20 parts of CITRAL (manufactured by Kuraray Co., Ltd.) was used as the fragrance compound. Otherwise, the same procedure as in the above-described manufacturing example 1 was used to obtain fragrance-encapsulated nanoparticles (particle 3).

[0116] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 61.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 15.4% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 98 nm.

[0117] (Manufacturing example 4) In the above-described manufacturing example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 50 parts, the amount of n-butyl methacrylate was 20 parts, and 30 parts of linalool (linalool oxide) (manufactured by Inoue Fragrance Manufacturing Co., Ltd.) was used as the fragrance compound. Otherwise, fragrance-encapsulated nanoparticles (particle 4) were obtained in the same manner as in the above-described manufacturing example 1.

[0118] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 61.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 23.1% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 78 nm.

[0119] (Manufacturing example 5) In the above-described production example 1, the amount of distilled water was 343.5 parts, the amount of cyclohexyl methacrylate was 45 parts, the amount of n-butyl methacrylate was 25 parts, and 26 parts of eugenol (manufactured by Nippon Terpene Chemical Co., Ltd.) was used as the fragrance compound. Otherwise, the same procedure as in production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particle 5).

[0120] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 61.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 20.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 101 nm.

[0121] (Manufacturing example 6) In the above-described production example 1, the amount of distilled water was 324.5 parts, the amount of cyclohexyl methacrylate was 50 parts, the amount of n-butyl methacrylate was 30 parts, and γ-decalactone (manufactured by Inoue Fragrance Manufacturing Co., Ltd.) was used as the fragrance compound. Otherwise, the same procedure as in production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particle 6).

[0122] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 64.3% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 25.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 94 nm.

[0123] (Manufacturing example 7) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 30 parts, the amount of n-butyl methacrylate was 45 parts, and 25 parts of 1,8-cineole (manufactured by Nippon Terpene Chemical Co., Ltd.) was used as the fragrance compound. Otherwise, fragrance-encapsulated nanoparticles (particle 7) were obtained in the same manner as in the above-described production example 1.

[0124] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 76 nm.

[0125] (Manufacturing example 8) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 30 parts, the amount of n-butyl methacrylate was 45 parts, and γ-terpinene was used as the fragrance compound. Otherwise, the same procedure as in production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particle 8).

[0126] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 88 nm.

[0127] (Manufacturing example 9) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 30 parts, the amount of n-butyl methacrylate was 45 parts, and 25 parts of cymene was used as the fragrance compound, otherwise the same procedure as in production example 1 was used to obtain fragrance-encapsulated nanoparticles (particles 9).

[0128] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 101 nm.

[0129] (Manufacturing example 10) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 35 parts, the amount of n-butyl methacrylate was 40 parts, and the amount of myrcene was 25 parts as a fragrance compound, otherwise the same procedure as in production example 1 was used to obtain fragrance-encapsulated nanoparticles (particles 10).

[0130] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 95 nm.

[0131] (Manufacturing Example 11) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 35 parts, the amount of n-butyl methacrylate was 40 parts, and 25 parts of phellandrene was used as the fragrance compound, otherwise the same procedure as in production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particles 11).

[0132] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 100 nm.

[0133] (Manufacturing Example 12) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 45 parts, the amount of n-butyl methacrylate was 30 parts, and 25 parts of farnesene was used as the fragrance compound, otherwise the same procedure as in production example 1 was followed to obtain fragrance-encapsulated nanoparticles (particles 12).

[0134] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 95 nm.

[0135] (Manufacturing Example 13) In the above-described production example 1, the amount of distilled water was 339.5 parts, the amount of cyclohexyl methacrylate was 45 parts, the amount of n-butyl methacrylate was 30 parts, and thugen was used as the fragrance compound, except that the same procedure was followed as in production example 1 to obtain fragrance-encapsulated nanoparticles (particles 13).

[0136] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from methacrylate ester was 63.0% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 98 nm.

[0137] (Manufacturing Example 14) Production of fragrance-encapsulated nanoparticles embedded in polymers other than methacrylate esters A 2-liter flask was fitted with a stirrer, reflux condenser, thermometer, nitrogen gas inlet tube, and 1000 ml separatory funnel for monomer addition, and placed in a hot water bath. 339.5 parts of distilled water, 50 parts of polymerizable surfactant (ADEKA Corporation, Adekaria Soap SR-10, ether sulfate), and 0.5 parts of ammonium persulfate were added, and the internal temperature was raised to 50°C while introducing nitrogen gas.

[0138] On the other hand, a solution was prepared by mixing 75 parts vinyl acetate (manufactured by Resonaq Corporation), 25 parts d-limonene (manufactured by Nippon Terpene Chemical Co., Ltd.) as a fragrance compound, and 10 parts crosslinking agent (trialyl isocyanurate, manufactured by Nippon Chemical Corporation, TAIC).

[0139] This prepared solution was added from the separatory funnel to the flask, which was kept at a temperature of approximately 50°C, under stirring for 3 hours to carry out emulsion polymerization. Subsequently, it was aged for 5 hours to complete the polymerization, obtaining a fragrance-encapsulated nanoparticle dispersion (dispersion) in which the fragrance was embedded within the polymer.

[0140] Subsequently, the obtained fragrance-encapsulated nanoparticle dispersion (dispersion liquid) was dried in a 50°C dryer for 24 hours to remove the dispersion medium, thereby obtaining fragrance-encapsulated nanoparticle powder (particle 14).

[0141] In the obtained fragrance-encapsulated nanoparticles, the content of the portion derived from vinyl acetate was 55.6% by mass relative to the total amount of polymer encapsulating the fragrance compound. The content of the fragrance compound was 18.5% by mass relative to the total amount of polymer encapsulating the fragrance compound. The average primary particle size of the fragrance-encapsulated nanoparticles was 87 nm.

[0142] <Example 1> As a base resin, 100 parts of polypropylene (product name: MG03BD, manufactured by Nippon Polypropylene Co., Ltd.) and 1 part of the fragrance-encapsulated nanoparticles (particle 1) obtained in the above manufacturing example were thoroughly kneaded in a Laboplast Mill (manufactured by Toyo Seiki Co., Ltd.) to obtain a resin composition (kneading conditions: 190°C, 60 rpm). The content of fragrance-encapsulated nanoparticles in the resin composition was 0.99% by mass of the total resin composition.

[0143] <Examples 2-13> Using the fragrance-encapsulated nanoparticles shown in Table 1 or Table 2, resin compositions were prepared in the same manner as in Example 1. Evaluation molded articles were then prepared from the obtained compositions in the same manner as in Example 1, and evaluated. The results are shown in Table 1 or Table 2.

[0144] <Comparative Example 1> As Comparative Example 1, a fragrance component with a solid content similar to that of Production Example 1 was directly mixed with polypropylene to obtain a resin composition. An evaluation molded product was prepared from the obtained composition in the same manner as in Example 1, and the evaluation was performed. The results are shown in Table 2.

[0145] <Comparative Example 2> As Comparative Example 2, a resin composition was obtained using the particles 14 obtained in Production Example 14. An evaluation molded product was prepared from the obtained composition in the same manner as in Example 1, and the evaluation was performed. The results are shown in Table 2.

[0146] <Rating> Evaluation molded products were formed from the resin compositions obtained above, and various evaluations were performed. The evaluation results are shown in Table 1 or Table 2.

[0147] (Moldability) An evaluation resin plate with a thickness of 2 mm was molded from the obtained resin composition using an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd.). Specifically, the resin molded product (pellet shape) containing fragrance-encapsulated nanoparticles was placed in the injection molding machine, melted at 200°C, and injected into the mold at a speed of 50 mm / s. Holding pressure was used as appropriate to ensure appearance. The mold was designed to produce a plate-shaped molded product with dimensions of 60 mm (length) x 60 mm (width) x 2 mm (thickness). Moldability was evaluated by the ease of filling the mold and the appearance of the obtained molded product. The evaluation criteria are shown below. A: Easy to fill and excellent molded product appearance. B: Filling is easy, but there are abnormalities in the appearance of the molded product. C: Unable to fill, or the molded product has an abnormal appearance.

[0148] (Long-lasting fragrance) The resin plates prepared as described above were evaluated by five evaluators based on the following criteria for residual fragrance intensity. The evaluation with the largest distribution among the five evaluators' results was used as the final evaluation result. A: The lingering scent is quite strong. B: The lingering scent feels weak. C: No lingering fragrance detected

[0149] (Dispersibility of fragrance-encapsulated nanoparticles) The surface of the evaluation resin plate prepared as described above was observed under a microscope. The presence or absence of irregularities or mottling caused by aggregates of fragrance-encapsulated nanoparticles was visually evaluated on the resin plate surface and the cut surface made by the cutter. The evaluation criteria are shown below. A: No unevenness or mottling caused by aggregates is observed. B: Partially visible are irregularities and patches caused by aggregates. C: Overall, irregularities and mottling due to aggregates are visible.

[0150] (Presence or absence of bleed-out fragrance compounds) The evaluation resin plates prepared as described above were stored for 3 months at a temperature of 25°C, and the bleeding of fragrance-encapsulated nanoparticles onto the surface of the resin plates was observed under a microscope. Specifically, the presence of oily or other bleeding substances on the surface of the resin plates was visually evaluated. The evaluation criteria are shown below. A: There are no bleed-out particles on the surface of the resin plate. B: Some bleed material is present on the surface of the resin plate. C: The surface of the resin plate has been altered due to bleeding.

[0151] (Maintaining resin performance) Dumbbell test specimens (ISO 527-2, Type 1A) were molded from the resin composition obtained above and from polypropylene without fragrance-encapsulated nanoparticles. Tensile tests (JIS standards: K7161-1, K7161-2) were performed on the obtained dumbbell test specimens using a universal testing machine (Toyo Seiki Seisakusho Co., Ltd.: Strograph VG10F). For the tensile tests, the physical properties of elastic modulus, shear strength, and elongation at breaking were evaluated. To assess the maintenance of resin performance, the physical properties of the test specimens containing fragrance-encapsulated nanoparticles were checked against a comparative sample of the test specimens without fragrance-encapsulated nanoparticles to see if there was any change in tensile properties. The evaluation criteria are shown below. A: No significant change in physical properties. B: There are some changes in physical properties. C: Physical properties change significantly

[0152] (Recyclability) The dumbbell test specimens prepared as described above were crushed and remolded using an injection molding machine to obtain molded products (recycled dumbbell test specimens) that had undergone repeated thermal history through recycling. Tensile tests (JIS standards: K7161-1, K7161-2) were performed on the obtained recycled dumbbell test specimens using a universal testing machine (Toyo Seiki Seisakusho Co., Ltd.: Strograph VG10F). For the tensile tests, the modulus of elasticity, strength, and elongation at the breaking point were evaluated. To assess recyclability, recycled dumbbell test specimens without fragrance-encapsulated nanoparticles were used as a comparison sample, and it was confirmed whether there was any change in the physical properties of the recycled test specimens containing fragrance-encapsulated nanoparticles during the tensile test. The evaluation criteria are shown below. A: No significant change in physical properties. B: There are some changes in physical properties. C: Physical properties change significantly

[0153] [Table 1]

[0154] [Table 2] [Industrial applicability]

[0155] The resin composition of the present invention offers flexibility in fragrance design, high dispersibility of fragrances, and retains its fragrance even when exposed to high-temperature environments during molding. The resulting molded articles have long-lasting fragrance, suppressed degradation of resin performance, and are recyclable. Molded articles obtained from the resin composition of the present invention can be applied to various uses where fragrance is desired. For example, the resin composition of the present invention can be suitably used as a material for writing instruments, cosmetic tools, and the like.

Claims

1. It contains a base resin and fragrance-encapsulating nanoparticles. The aforementioned fragrance-encapsulated nanoparticles are those in which a fragrance compound is encapsulated within a polymer. The polymer is a reaction product of monomers containing a (meth)acrylic acid ester represented by the following general formula (I). Resin composition. 【Chemistry 1】 (In the above formula (I), A is a hydrogen atom or a methyl group, and R is a hydrogen atom, a C1-C22 alkyl group, or a group having a polyalkylene glycol chain having 2-C18 atoms in the alkylene chain. The alkyl group or the group having a polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, a C1-C18 alkoxy group, a C1-C18 perfluoroalkyl group, or a trialkoxysilyl group as a substituent.)

2. The resin composition according to claim 1, wherein the content of the fragrance compound in the fragrance-encapsulated nanoparticles is 1% by mass or more relative to 100% by mass of the polymer.

3. The resin composition according to claim 1 or 2, wherein the average primary particle size of the fragrance-encapsulating nanoparticles is 20 nm or more and 800 nm or less.

4. The resin composition according to claim 1 or 2, wherein the content of the fragrance-encapsulating nanoparticles in the resin composition is 0.1% by mass or more and 10% by mass or less of the total resin composition.

5. The resin composition according to claim 1 or 2, wherein the base resin has a melting point or softening point of 200°C or lower.

6. The resin composition according to claim 1 or 2, wherein the base resin is at least one selected from the group consisting of polypropylene, polyethylene, polylactic acid, olefin-based elastomers, and styrene-based elastomers.

7. A resin molded article obtained from the resin composition according to claim 1 or 2.

8. A writing instrument obtained from the resin composition according to claim 1 or 2.

9. A cosmetic tool obtained from the resin composition according to claim 1 or 2.

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