Oil-in-water emulsion composition

Abstract

Monomer units AU represented by general formula (1) (wherein R 1 represents a hydrocarbon group having 3 to 22 carbon atoms) and a monomer unit BU represented by general formula (2) (wherein R 2 An oil-in-water emulsion composition comprising a polyaspartic acid derivative having a specific ratio of a hydrocarbon group having 1 to 20 carbon atoms and a heteroatom (wherein represents a hydrocarbon group having 1 to 20 carbon atoms and a heteroatom), and an oily component. TIFF0007729511000016.tif61170

Description

[Technical Field]

[0001] The present disclosure relates to an oil-in-water emulsion composition containing a polyaspartic acid derivative. [Background technology]

[0002] Polyacrylic acid polymers, such as carboxyvinyl polymer, are widely known as thickeners and have been used in a variety of applications, including toiletries and cosmetics. Although a small amount of carboxyvinyl polymer can produce a moist gel, there is a growing demand for thickeners that can replace carboxyvinyl polymers from an environmentally friendly perspective.

[0003] Polysaccharides such as xanthan gum are known as thickeners that can replace carboxyvinyl polymers (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-095340 Summary of the Invention [Problem to be solved by the invention]

[0005] However, polysaccharides such as xanthan gum sometimes do not have a sufficient thickening effect. Therefore, an object of the present disclosure is to provide an oil-in-water emulsion composition that contains a thickener with low environmental impact and has sufficient viscosity. [Means for solving the problem]

[0006] As a result of intensive research to solve the above-mentioned problems, the inventors of the present disclosure discovered that the above-mentioned problems can be solved by using a polyaspartic acid derivative having a specific structure as a thickener, and thus completed the invention of the present disclosure.

[0007] That is, the gist of the present disclosure is as follows. [1] Contains a polyaspartic acid derivative and an oily component, The polyaspartic acid derivative comprises an α- or β-aspartic acid monomer unit AU represented by the following general formula (1) and an α- or β-aspartic acid monomer unit BU represented by the following general formula (2), The oil-in-water emulsion composition, wherein the ratio (AU) / (BU) of the content (mol %) of the monomer units AU to the content (mol %) of the monomer units BU in the polyaspartic acid derivative is 40 / 60 to 60 / 40. [ka] (In the formula, R 1 represents a hydrocarbon group having 3 to 22 carbon atoms. [ka] (In the formula, R 2 represents a hydrocarbon group containing a heteroatom and having 1 to 20 carbon atoms. [2] The polyaspartic acid derivative further contains a succinimide monomer unit CU represented by the following formula (3): [1] The oil-in-water emulsion composition according to [1], wherein the ratio of the total content (mol %) of the monomer units AU and BU to the content (mol %) of the monomer units CU in the polyaspartic acid derivative, [(AU)+(BU)] / (CU), is 80 / 20 to 99 / 1. [ka] [3] The oil-in-water emulsion composition according to [1] or [2], wherein the polyaspartic acid derivative further contains an α- or β-aspartic acid monomer unit Crosslink-U represented by the following formula (4): [ka] (In the formula, the wavy lines indicate crosslinking sites.) [4] The oil-in-water emulsion composition according to [3], wherein the content of the Crosslink-U monomer unit in the polyaspartic acid derivative is 0.1 mol % to 2.0 mol %. [5] The oil-in-water emulsion composition according to any one of [1] to [4], wherein the polyaspartic acid derivative has a hydroxyl value of 80 mgKOH / g to 170 mgKOH / g. [6] The oil-in-water emulsion composition according to any one of [1] to [5], wherein the content of the polyaspartic acid derivative relative to the total amount of the oil-in-water emulsion composition is 0.1 wt % to 2.0 wt %. [7] The oil-in-water emulsion composition according to any one of [1] to [6], further comprising an emulsifier. [8] The oil-in-water emulsion composition according to [7], wherein the content of the emulsifier relative to the total amount of the oil-in-water emulsion composition is 0.5% by weight to 15.0% by weight. [9] The oil-in-water emulsion composition according to [7] or [8], wherein the emulsifier is one or more selected from the group consisting of nonionic surfactants and amphoteric surfactants.

[10] The oil-in-water emulsion composition according to [9], wherein the nonionic surfactant is one or more selected from the group consisting of polyglycerin fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters.

[11] The oil-in-water emulsion composition according to [9] or

[10] , wherein the amphoteric surfactant is optionally hydrogenated lecithin.

[12] The oil-in-water emulsion composition according to any one of [1] to

[11] , wherein the content of the oily component relative to the total amount of the oil-in-water emulsion composition is 1.0 wt % to 50.0 wt %.

[13] The oil-in-water emulsion composition according to any one of [1] to

[12] , which is an external preparation for skin.

[14] The oil-in-water emulsion composition according to

[13] , which is a cosmetic.

[15] The oil-in-water emulsion composition according to

[13] or

[14] , which is a cream or emulsion. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide an oil-in-water emulsion composition that contains a thickener that has a low environmental impact and has sufficient viscosity. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present disclosure will be described in more detail below. Note that the present disclosure is not limited to the following embodiments.

[0010] The expressions "XX or more and YY or less" or "XX to YY" that represent a numerical range mean a numerical range including the endpoints, that is, the lower limit and the upper limit, unless otherwise specified. When numerical ranges are stated in stages, the upper and lower limits of each numerical range can be combined in any way.

[0011] Hereinafter, each component contained in the oil-in-water emulsion composition according to one embodiment of the present disclosure (hereinafter also simply referred to as the "composition of the present disclosure" or "composition") will be described.

[0012] [Polyaspartic acid derivatives] The composition of the present disclosure contains a polyaspartic acid derivative. The polyaspartic acid derivative can function as a thickener and, since it is a biodegradable polymer, has a low environmental impact. The polyaspartic acid derivative may also function as an emulsifier. The polyaspartic acid derivative contains an α- or β-aspartic acid monomer unit AU (also referred to as a "monomer unit AU") represented by the following general formula (1), and an α- or β-aspartic acid monomer unit BU (also referred to as a "monomer unit BU") represented by the following general formula (2). That is, the polyaspartic acid derivative contains the monomer unit AU and the monomer unit BU as repeating units. In the present disclosure, "polyaspartic acid" includes a polymer obtained by peptide condensation polymerization of aspartic acid. In the composition of the present disclosure, the polyaspartic acid derivatives may be used alone or in combination of two or more.

[0013] [ka] (In the formula, R 1 represents a hydrocarbon group having 3 to 22 carbon atoms.

[0014] [ka] (In the formula, R 2 represents a hydrocarbon group containing a heteroatom and having 1 to 20 carbon atoms.

[0015] The use of polyaspartic acid derivatives makes it possible to obtain oil-in-water emulsion compositions with high viscosity, and also to reduce the emulsion particle size, thereby making it possible to obtain oil-in-water emulsion compositions with high emulsion stability. The above-mentioned effects can be obtained by adding a polyaspartic acid derivative to an oil-in-water emulsion composition because the polyaspartic acid derivative increases the viscosity of the aqueous phase while forming hard emulsion particles. The reason why polyaspartic acid derivatives can improve the viscosity of the aqueous phase is that polyaspartic acid derivatives contain R of the monomer unit AU in the molecule. 1 and R of the monomer unit BU 2 In the aqueous phase, the polyaspartic acid derivative contains groups represented by R 1 While having intramolecular interaction points between groups represented by R 1 By not having too many groups represented by R, intermolecular interactions are promoted and thickening power is achieved. 1 If there are too many groups represented by R, particles will form with just one molecule, reducing intermolecular interactions and decreasing the viscosity increasing power. 2 While providing hydrophilicity by the group represented by 2 By not having too many groups represented by R, hydrolysis of the main chain of the polyaspartic acid derivative can be suppressed, and viscosity stability is maintained. 1 and R 2and a group represented by the formula (I) in an appropriate balance, the polyaspartic acid derivative is thought to be able to increase and maintain the viscosity of the aqueous phase, thereby increasing the viscosity of the oil-in-water emulsion composition. Furthermore, it is speculated that the reason for obtaining hard emulsion particles is that the polyaspartic acid derivative is oriented not only in the aqueous phase but also at the interface between the aqueous and oil phases, forming stable emulsion particles. For the same reason, emulsion particles with small particle sizes can be formed, which prevents viscosity loss during long-term storage and improves viscosity stability. Furthermore, when the composition of the present disclosure is used as an external preparation for skin, particularly in the form of a cream or emulsion, it provides a sensation of disintegrating quickly as if it were melting when applied to the skin with the fingers. This sensation is presumably due to the polyaspartic acid derivative present in the external aqueous phase.

[0016] The monomer unit AU is a unit obtained by opening the imide ring in the succinimide monomer unit of polysuccinimide through a reaction between amine A and polysuccinimide, which are used in the production method of polyaspartic acid derivatives described below. The monomer unit BU is a unit obtained by opening the imide ring in the succinimide monomer unit of polysuccinimide through a reaction between amine B and polysuccinimide, which are used in the production method of polyaspartic acid derivatives described below.

[0017] In general formula (1), R 1is not particularly limited as long as it is a hydrocarbon group having 3 to 22 carbon atoms, and the hydrocarbon group having 3 to 22 carbon atoms may be saturated or unsaturated, and may be branched or linear. Specific examples of hydrocarbon groups having 3 to 22 carbon atoms include linear alkyl groups such as propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl; branched alkyl groups such as isopropyl, isobutyl, isopentyl, and isohexyl; cycloalkyl groups such as cyclobutyl, cyclopentyl, and cyclohexyl; cycloalkylalkyl groups such as cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, cyclobutylethyl, cyclopentylethyl, cyclohexylethyl, cyclobutylpropyl, cyclopentylpropyl, cyclohexylpropyl, cyclobutylbutyl, cyclopentylbutyl, and cyclohexylbutyl; and alkenyl groups such as propenyl, butenyl, pentenyl, and hexenyl. Among these, the hydrocarbon group having 3 to 22 carbon atoms is preferably a linear alkyl group or a branched alkyl group.

[0018] The number of carbon atoms in the hydrocarbon group having 3 to 22 carbon atoms is 3 or more, preferably 4 or more, more preferably 5 or more, even more preferably 6 or more, even more preferably 7 or more, even more preferably 8 or more, even more preferably 9 or more, even more preferably 10 or more, and still more preferably 11 or more. On the other hand, the number of carbon atoms in the hydrocarbon group having 3 to 22 carbon atoms is 22 or less, preferably 21 or less, more preferably 20 or less, even more preferably 19 or less, even more preferably 18 or less, even more preferably 17 or less, even more preferably 16 or less, even more preferably 15 or less, and still more preferably 14 or less. The number of carbon atoms in the hydrocarbon group having 3 to 22 carbon atoms is specifically, for example, 3 to 22, 4 to 21, 5 to 20, 6 to 19, 7 to 18, 8 to 17, 9 to 16, 10 to 15, or 11 to 14.

[0019] The monomer unit AU contained in one molecule of the polyaspartic acid derivative may be of one type alone or of two or more types.

[0020] The content of the AU monomer units in the monomer units constituting the polyaspartic acid derivative is preferably 40 mol% or more, more preferably 43 mol% or more, and even more preferably 45 mol% or more. On the other hand, the content of the AU monomer units in the monomer units constituting the polyaspartic acid derivative is preferably 60 mol% or less, more preferably 58 mol% or less, and even more preferably 57 mol% or less. Specifically, the content of the AU monomer units in the monomer units constituting the polyaspartic acid derivative is, for example, 40 mol% to 60 mol%, 43 mol% to 58 mol%, or 45 mol% to 57 mol%. The content of the AU monomer units in the monomer units constituting the polyaspartic acid derivative can be adjusted by the amount of amine A and other raw materials charged. In the present disclosure, the term "monomer units constituting a polyaspartic acid derivative" refers to, among the monomer units constituting a polyaspartic acid derivative, monomer units derived from succinimide monomer units of polysuccinimide (specifically, monomer units AU, BU, CU, and Crosslink-U, as well as monomer units derived from succinimide monomer units of other polysuccinimide that do not fall under these monomer units).

[0021] The content of the monomer unit AU is 1 Specifically, the obtained 1 Calculate using the H-NMR spectrum using the following formula: Content of monomer unit AU (mol %)=(peak integral value of methyl group derived from amine A / 3)×100 / ((peak integral value of methyl group derived from amine A / 3)+(peak integral value of methylene group derived from amine B / 2)+(peak integral value of methine group of succinimide monomer unit))

[0022] The content of the monomer unit AU can also be calculated by the method described in the Examples below. That is, the content of the monomer unit AU can also be calculated from the ratio (%) of the amount (mol) of amine A charged to the amount (mol) of polysuccinimide charged in the production method of a polyaspartic acid derivative described below. In the present disclosure, the "amount (mol) of polysuccinimide charged" means the value obtained by dividing the weight of the amount of polysuccinimide charged by the molecular weight of the repeating unit of polysuccinimide.

[0023] In general formula (2), R 2 is not particularly limited as long as it is a hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom. The hydrocarbon group having 1 to 20 carbon atoms may be saturated or unsaturated, and may be branched or linear. The hetero atom may be one or more selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom include saturated or unsaturated hydrophilic hydrocarbon groups containing a nitrogen atom, an oxygen atom, a sulfur atom, etc. Specific examples of the hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom include hydroxyalkyl groups such as a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group, a hydroxyheptyl group, and a hydroxyoctyl group; an azapropyl group, an azabutyl group, an azapentyl group, an azahexyl group, an N,N-dimethylaminobutyl group, an N,N-dimethylaminopropyl group, an N,N-dimethylaminoethyl ... Azaalkyl groups such as methylaminomethyl group, N,N-diethylaminobutyl group, N,N-diethylaminopropyl group, N,N-diethylaminoethyl group, and N,N-diethylaminomethyl group; azaalkenyl groups such as azapropenyl group, azabutenyl group, azapentenyl group, azahexenyl group, N,N-dimethylaminopropenyl group, N,N-dimethylaminobutenyl group, N,N-dimethylaminohexenyl group, and N,N-diethylaminopropenyl group; oxaethyl group, oxapro group oxaalkyl groups such as oxabutyl, oxapentyl, oxahexyl, oxaheptyl, and oxaoctyl; oxaalkylenyl groups such as oxapropenyl, oxabutenyl, oxopentenyl, oxahexenyl, oxaheptenyl, and oxaoctenyl; thioalkyl groups such as thiobutyl, thiopentyl, thiohexyl, thioheptyl, and thiooctyl; thioalkenyl groups such as thiopentenyl, thiohexenyl, thioheptenyl, and thiooctenyl; hydroxyalkoxyalkyl groups such as hydroxyethoxyethyl, hydroxyethoxypropyl, hydroxyethoxybutyl, hydroxypropoxyethyl, hydroxypropoxypropyl, and hydroxypropoxybutyl; alkoxyalkoxyalkyl groups such as methoxyethoxyethyl, methoxyethoxypropyl, methoxyethoxybutyl, methoxypropoxyethyl, methoxypropoxypropyl, and methoxypropoxybutyl;Examples of such alkyl groups include alkoxyalkyl groups such as methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, methoxypentyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, and ethoxypentyl groups; dihydroxyalkyl groups such as dihydroxyethyl, dihydroxypropyl, and dihydroxybutyl groups; and polyhydroxyalkyl groups such as the group obtained by removing the amino group (—NH—) from D-glucamine.

[0024] The number of carbon atoms in the hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom is 1 or more, and preferably 2 or more. On the other hand, the number of carbon atoms in the hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom is 20 or less, preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, even more preferably 12 or less, even more preferably 10 or less, even more preferably 8 or less, and still more preferably 6 or less. The number of carbon atoms in the hydrocarbon group having 1 to 20 carbon atoms and containing a hetero atom is specifically, for example, 1 to 20, 1 to 18, 1 to 16, 1 to 14, 1 to 12, 1 to 10, 2 to 8, or 2 to 6.

[0025] R 2 is preferably a group selected from the group consisting of an N,N-dimethylaminopropyl group, an N,N-diethylaminopropyl group, a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group, a hydroxyethoxyethyl group, a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a methoxybutyl group, a methoxypentyl group, an ethoxymethyl group, an ethoxyethyl group, an ethoxypropyl group, an ethoxybutyl group, an ethoxypentyl group, and a dihydroxypropyl group.

[0026] R 2 Hydroxyalkyl groups are more preferred. Examples of hydroxyalkyl groups include a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, and a hydroxyhexyl group.

[0027] The monomer unit BU contained in one molecule of the polyaspartic acid derivative may be of one type alone or of two or more types.

[0028] The content of the BU monomer units in the monomer units constituting the polyaspartic acid derivative is preferably 30 mol% or more, more preferably 32 mol% or more, and even more preferably 35 mol% or more. On the other hand, the content of the BU monomer units in the monomer units constituting the polyaspartic acid derivative is preferably 60 mol% or less, more preferably 50 mol% or less, and even more preferably 45 mol% or less. Specific examples of the content of the BU monomer units in the monomer units constituting the polyaspartic acid derivative are 30 mol% to 60 mol%, 32 mol% to 50 mol%, or 35 mol% to 45 mol%. The content of the BU monomer units in the monomer units constituting the polyaspartic acid derivative can be adjusted by the amounts of amine B and other raw materials used in the production method for the polyaspartic acid derivative described below.

[0029] The content of the monomer unit BU is 1 Specifically, the obtained 1 Calculate using the H-NMR spectrum using the following formula: Content of monomer unit BU (mol %)=(peak integral value of methylene group derived from amine B / 2)×100 / ((peak integral value of methyl group derived from amine A / 3)+(peak integral value of methylene group derived from amine B / 2)+(peak integral value of methine group of succinimide monomer unit))

[0030] The content of the monomer unit BU can also be calculated by the method described in the Examples below, i.e., the content of the monomer unit BU can also be calculated from the ratio (%) of the amount (mol) of amine B charged to the amount (mol) of polysuccinimide charged.

[0031] In the polyaspartic acid derivative, the ratio of the content (mol %) of the monomer unit AU to the molar % of the monomer unit BU (also expressed as (AU) / (BU)) is 40 / 60 to 60 / 40, preferably 45 / 55 to 60 / 40, and more preferably 50 / 50 to 60 / 40. If it is in the above range, the compatibility with water and viscosity are improved. In the present disclosure, the ratio is 1 The value is calculated from H-NMR. 1 The detailed calculation method from H-NMR will be explained in the section (Calculation of composition ratio and hydroxyl value of polyaspartic acid derivative 1) in the Examples.

[0032] The polyaspartic acid derivative preferably further contains a succinimide monomer unit CU (also referred to as "monomer unit CU") represented by the following formula (3): That is, the polyaspartic acid derivative preferably contains the monomer units AU, BU, and CU as repeating units. The monomer unit CU is an unreacted imide ring remaining in the ring-opening reaction of polysuccinimide in the production method of the polyaspartic acid derivative described below.

[0033] [ka]

[0034] In the polyaspartic acid derivative, the ratio of the total content (mol %) of the monomer units AU and BU to the content (mol %) of the monomer units CU (also represented as [(AU)+(BU)] / (CU)) is 80 / 20 to 99 / 1, preferably 85 / 15 to 98 / 1, more preferably 90 / 10 to 98 / 2, and even more preferably 90 / 10 to 97 / 2. In the present disclosure, the ratio 1 The value is calculated from H-NMR. 1 The detailed calculation method from H-NMR will be explained in the section (Calculation of composition ratio and hydroxyl value of polyaspartic acid derivative 1) in the Examples.

[0035] The polyaspartic acid derivative preferably further contains an α- or β-aspartic acid monomer unit Crosslink-U (also referred to as a "monomer unit Crosslink-U") represented by the following formula (4). That is, the polyaspartic acid derivative preferably contains the monomer units AU, BU, and Crosslink-U as repeating units. Furthermore, the polyaspartic acid derivative more preferably contains the monomer units AU, BU, CU, and Crosslink-U. That is, the polyaspartic acid derivative more preferably contains the monomer units AU, BU, CU, and Crosslink-U as repeating units. The monomer unit Crosslink-U is a unit formed by opening the imide ring in the succinimide monomer unit of polysuccinimide through a reaction between the polysuccinimide and a crosslinking agent used in the production method of the polyaspartic acid derivative described below.

[0036] [ka] (In the formula, the wavy lines indicate crosslinking sites.)

[0037] When the polyaspartic acid derivative contains the monomer unit Crosslink-U, the polyaspartic acid derivative is preferably a slightly crosslinked modified polyaspartic acid derivative. Here, "slightly crosslinked modified polyaspartic acid derivative" refers to a modified polyaspartic acid derivative having a crosslinking amount of 0.1 mol % to 2.0 mol %. "Slightly crosslinked" is distinguished from normal "crosslinked" in which the crosslinking amount exceeds 2.0 mol %. For example, because the slightly crosslinked polymer has a small amount of crosslinking, it does not gel in a solution of a given concentration and is more likely to maintain a certain level of fluidity.

[0038] When the polyaspartic acid derivative contains the monomer unit Crosslink-U, the crosslinking amount in the polyaspartic acid derivative (i.e., the content of the monomer unit Crosslink-U in the constituent monomers of the polyaspartic acid derivative) is preferably 0.1 mol % or more, more preferably 0.3 mol % or more, and even more preferably 0.5 mol % or more. On the other hand, the crosslinking amount in the polyaspartic acid derivative is preferably 2.0 mol % or less, more preferably 1.8 mol % or less, and even more preferably 1.7 mol % or less. Specifically, the crosslinking amount in the polyaspartic acid derivative is, for example, 0.1 mol % to 2.0 mol %, 0.3 mol % to 1.8 mol %, or 0.5 mol % to 1.7 mol %. The crosslinking amount can be adjusted by the amount of crosslinking agent and the amount of each of the other raw materials charged. The crosslinking amount can be calculated from the ratio (%) of the amount (mol) of the crosslinking agent charged to the amount (mol) of the polysuccinimide charged.

[0039] The bonding form of the monomer units AU, BU, CU, and Crosslink-U may be any of random, block, and tapered. The bonding form of each of these monomer units may be any of linear, macrocyclic, branched, star, and three-dimensional network, but is preferably linear.

[0040] The polyaspartic acid derivative may contain other monomer units than the monomer units AU, BU, CU, and Crosslink-U, as long as the effects of the present disclosure are not significantly impaired. The other monomer units are monomer units derived from the succinimide monomer units of polysuccinimide that do not fall under the monomer units AU, BU, CU, and Crosslink-U. Examples of other monomer units include units formed by opening the imide ring in the succinimide monomer unit of polysuccinimide through a reaction between another monoamine described below and polysuccinimide.

[0041] The hydroxyl value of the polyaspartic acid derivative is preferably 80 mgKOH / g or more, more preferably 100 mgKOH / g or more. On the other hand, the hydroxyl value of the polyaspartic acid derivative is preferably 170 mgKOH / g or less, more preferably 150 mgKOH / g or less, even more preferably 120 mgKOH / g or less, and even more preferably 110 mgKOH / g or less. Specifically, the hydroxyl value of the polyaspartic acid derivative is, for example, 80 mgKOH / g to 170 mgKOH / g, 100 mgKOH / g to 150 mgKOH / g, 80 mgKOH / g to 120 mgKOH / g, or 100 mgKOH / g to 110 mgKOH / g. The hydroxyl value can be adjusted by the amounts of amine A and amine B charged. The method for calculating the hydroxyl value will be explained in the section (Calculation of the composition ratio and hydroxyl value of polyaspartic acid derivative 1) in the Examples.

[0042] The weight-average molecular weight (Mw) of the polyaspartic acid derivative is not particularly limited, but is preferably 80,000 or more, more preferably 100,000 or more, and even more preferably 120,000 or more. The weight-average molecular weight of the polyaspartic acid derivative is preferably 700,000 or less, more preferably 600,000 or less, even more preferably 500,000 or less, even more preferably 300,000 or less, even more preferably 200,000 or less, and even more preferably 170,000 or less. Specifically, the weight-average molecular weight of the polyaspartic acid derivative is, for example, 80,000 to 700,000, 100,000 to 600,000, 120,000 to 500,000, 80,000 to 300,000, 100,000 to 200,000, or 120,000 to 170,000. The weight-average molecular weight of the polyaspartic acid derivative can be adjusted by the molecular weight of the polysuccinimide used in the production method of the polyaspartic acid derivative described below, and the types of amine A and amine B. The weight-average molecular weight here refers to a converted value measured by the GPC method (differential refractometer) using polystyrene as a standard substance, and specifically refers to the weight-average molecular weight measured using a G1000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), a G4000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), or a GMHHR-H column (TSKgel (registered trademark), manufactured by Tosoh Corporation) using dimethylformamide containing 10 mM lithium bromide as an eluent.

[0043] The polyaspartic acid derivative can be obtained by ring-opening polysuccinimide using amine A and amine B, which will be described later. When the polyaspartic acid derivative contains the monomer unit Crosslink-U, the polyaspartic acid derivative can be obtained by ring-opening polysuccinimide using amine A and amine B, and then forming a crosslinked moiety with a crosslinking agent. Unreacted imide rings may remain in the ring-opening reaction of polysuccinimide. In this case, the compound of the present disclosure further contains the monomer unit CU.

[0044] [Polysuccinimide (PSI)] Polysuccinimide (PSI) is a polymer represented by the following formula (5): The repeating unit in formula (5) is the same as the monomer unit CU.

[0045] [ka] (In the formula, n=10~10000)

[0046] The method for producing polysuccinimide (PSI) is not particularly limited. For example, it can be produced by dehydration condensation of aspartic acid while heating at 170 to 190°C in a vacuum in the presence of phosphoric acid. To produce a polysuccinimide with a higher molecular weight, the polysuccinimide obtained as described above can be treated with a condensing agent such as dicyclohexylcarbodiimide. The molecular weight of the polysuccinimide is not particularly limited. For example, the weight-average molecular weight of the polysuccinimide is preferably 20,000 or more, more preferably 50,000 or more, and even more preferably 70,000 or more. On the other hand, the weight-average molecular weight of the polysuccinimide is preferably 500,000 or less, and more preferably 200,000 or less. Specifically, the weight-average molecular weight of the polysuccinimide is, for example, 20,000 to 500,000, 50,000 to 500,000, or 70,000 to 200,000. The weight-average molecular weight here refers to a converted value measured by the GPC method (differential refractometer) using polystyrene as a standard substance, and specifically refers to the weight-average molecular weight measured using a G1000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), a G4000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), or a GMHHR-H column (TSKgel (registered trademark), manufactured by Tosoh Corporation) using dimethylformamide containing 10 mM lithium bromide as an eluent.

[0047] [Crosslinking agent] The cross-linking agent is not particularly limited as long as it can form a cross-linked moiety. Specific examples of cross-linking agents preferred for forming an amide bond used in the cross-linked moiety include polyfunctional amines.

[0048] The polyfunctional amine is preferably an amine having at least two primary and / or secondary amino groups. Examples of diamines include aliphatic diamines such as ethylenediamine and hexamethylenediamine, and aliphatic diamines containing aromatic rings such as xylenediamine; alicyclic diamines such as norbornenediamine; ether-based diamines such as 1,2-bis(2-aminoethoxy)ethane (AEE), diethylene glycol bis(3-aminopropyl)ether, bis[2-(3-aminopropoxy)ethyl]ether (APEE), polyoxyethylenediamine, and polyoxypropylenediamine; amino acids and derivatives thereof having amino groups in the side chains, such as lysine and ornithine; and monoamino compounds linked by disulfide bonds, such as cystine and cystamine, and derivatives thereof. The polyfunctional amine preferably does not contain the above amino acids and derivatives thereof. The polyfunctional amine is preferably an ether-based diamine, as its flexible structure makes it less likely to generate insoluble matter during the crosslinking reaction and makes the crosslinking reaction easier to control.

[0049] Examples of polyfunctional amines other than diamines include tris(2-aminoalkyl)amines (wherein the alkyl preferably has 1 to 5 carbon atoms, and more preferably 2 to 4 carbon atoms), such as tris(2-aminoethyl)amine (TREN) and tris(3-aminopropyl)amine; polyethylene polyamines, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine; and the like.

[0050] Among these, preferred examples of polyfunctional amines include 1,2-bis(2-aminoethoxy)ethane (AEE), bis[2-(3-aminopropoxy)ethyl]ether (APEE), and tris(2-aminoethyl)amine (TREN).

[0051] The reaction of polysuccinimide with a polyfunctional amine can be carried out in an organic solvent, for example. This method will be described using a preferred example in which the polyfunctional amine is a diamine, but the reaction conditions and procedures, such as the type of organic solvent, are not limited to those described below. In the method of reacting polysuccinimide with diamine in an organic solvent, polysuccinimide is dissolved in an organic solvent (preferably an aprotic polar organic solvent) such as dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylimidazolidinone (DMI), dimethyl sulfoxide (DMSO), or sulfolane to prepare a polysuccinimide solution, and then diamine or a diamine solution in the organic solvent is added dropwise to the polysuccinimide solution. The amount of organic solvent used to dissolve polysuccinimide is not particularly limited, but is usually adjusted to a polymer concentration of 1 to 50% by mass.

[0052] The temperature at which the polysuccinimide and the diamine are reacted is not particularly limited, but is, for example, room temperature to 80° C. In the present disclosure, "room temperature" refers to a temperature condition in which no external heating or cooling is performed, and specifically, is 15° C. to 30° C.

[0053] The reaction conditions (reaction temperature, reaction time, reaction concentration, amount of diamine used, etc.) are not particularly limited, but it is desirable to set the conditions such that the entire reaction solution does not gel.

[0054] [Amine A and Amine B] As the amine A, a primary amine represented by the following general formula (6) is used. R 1 -NH2(6) (In the formula, R 1 represents a hydrocarbon group having 3 to 22 carbon atoms.

[0055] As the amine B, a primary amine represented by the following general formula (7) is used. R 2 -NH2(7) (In the formula, R 2 represents a hydrocarbon group containing a heteroatom and having 1 to 20 carbon atoms.

[0056] R in general formula (6) 1 Regarding the general formula (1), R 1 The explanation for R in general formula (7) is also incorporated herein. 2 Regarding the general formula (2), R 2 The amine A and the amine B (these are also collectively referred to as "monoamines") may be commercially available products, or products prepared by known methods may be used.

[0057] Examples of amine A include linear alkylamines such as propylamine, butylamine, pentylamine, hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, and octadecylamine; branched alkylamines such as isopropylamine, isobutyl, isopentylamine, and isohexylamine; cycloalkylamine groups such as cyclobutylamine, cyclopentylamine, and cyclohexylamine; (cyclobutylmethyl)amine, (cyclopentylmethyl)amine, (cyclohexylmethyl)amine, (cyclobutylethyl)amine, (cyclopentylethyl)amine, (cyclohexylethyl)amine, (cyclobutylpropyl)amine, (cyclopentylpropyl)amine, (cyclohexylpropyl)amine, (cyclobutylbutyl)amine, (cyclopentylbutyl)amine, and (cyclohexylbutyl)amine; and alkenylamines such as propenylamine, butenylamine, pentenylamine, and hexenylamine. Among these, the amine A is preferably an amine selected from the group consisting of linear alkylamines and branched alkylamines.

[0058] Examples of amine B include hydroxyalkylamines such as hydroxymethylamine, hydroxyethylamine, hydroxypropylamine, hydroxybutylamine, hydroxypentylamine, hydroxyhexylamine, hydroxyheptylamine, and hydroxyoctylamine; azapropylamine, azabutylamine, azapentylamine, azahexylamine, (N,N-dimethylaminobutyl)amine, (N,N-dimethylaminopropyl)amine, (N,N-dimethylaminoethyl)amine, and the like. azaalkylamines such as (N,N-dimethylaminomethyl)amine, (N,N-diethylaminobutyl)amine, (N,N-diethylaminopropyl)amine, (N,N-diethylaminoethyl)amine, and (N,N-diethylaminomethyl)amine; azapropenylamine, azabutenylamine, azapentenylamine, azahexenylamine, (N,N-dimethylaminopropenyl)amine, (N,N-dimethylaminobutenyl)amine, (N,N-dimethylaminohexenyl)amine, and (N,N-diethylaminomethyl)amine; azaalkenylamines such as (hydroxyethoxy)ethylamine, (hydroxyethoxy)propylamine, (hydroxyethoxy)butylamine, (hydroxypentylamine, (hydroxyhexylamine, (oxaheptylamine, (oxaoctylamine, etc.); oxaalkylamines such as oxaethylamine, oxapropylamine, oxabutylamine, oxapentylamine, oxahexenylamine, oxaheptenylamine, and oxaoctenylamine; oxaalkylkenylamines such as oxapropenylamine, oxabutenylamine, oxopentenylamine, oxahexenylamine, oxaheptenylamine, and oxaoctenylamine; thioalkylamines such as thiobutylamine, thiopentylamine, thiohexylamine, thioheptylamine, and thiooctylamine; thioalkenylamines such as thiopentenylamine, thiohexenylamine, thioheptenylamine, and thiooctenylamine; [(hydroxyalkoxy)alkyl]amines such as [(hydroxyethoxy)ethyl]amine, [(hydroxyethoxy)propyl]amine, [(hydroxyethoxy)butyl]amine, [(hydroxypropoxy)ethyl]amine, [(hydroxypropoxy)propyl]amine, and [(hydroxypropoxy)butyl]amine;[(alkoxyalkoxy)alkyl]amines such as [(methoxyethoxy)ethyl]amine, [(methoxyethoxy)propyl]amine, [(methoxyethoxy)butyl]amine, [(methoxypropoxy)ethyl]amine, [(methoxypropoxy)propyl]amine, and [(methoxypropoxy)butyl]amine; alkoxyalkylamines such as methoxymethylamine, methoxyethylamine, methoxypropylamine, methoxybutylamine, methoxypentylamine, ethoxymethylamine, ethoxyethylamine, ethoxypropylamine, ethoxybutylamine, and ethoxypentylamine; dihydroxyalkylamines such as dihydroxyethylamine, dihydroxypropylamine, and dihydroxybutylamine; and polyhydroxyalkylamines such as D-glucamine. Among these, amine B is preferably an amine selected from the group consisting of (N,N-dimethylaminopropyl)amine, (N,N-diethylaminopropyl)amine, hydroxymethylamine, hydroxyethylamine, hydroxypropylamine, hydroxybutylamine, hydroxypentylamine, hydroxyhexylamine, [(hydroxyethoxy)ethyl]amine, methoxymethylamine, methoxyethylamine, methoxypropylamine, methoxybutylamine, methoxypentylamine, ethoxymethylamine, ethoxyethylamine, ethoxypropylamine, ethoxybutylamine, ethoxypentylamine, and dihydroxypropylamine, and more preferably an amine selected from the group consisting of hydroxyethylamine, hydroxypropylamine, hydroxybutylamine, hydroxypentylamine, and hydroxyhexylamine.

[0059] Amine A and amine B may each be used alone or in combination of two or more thereof.

[0060] [Method for producing polyaspartic acid derivatives] As a method for producing a polyaspartic acid derivative, for example, a method of ring-opening reaction of polysuccinimide using polysuccinimide and a monoamine can be mentioned. Furthermore, when the polyaspartic acid derivative contains the monomer unit Crosslink-U, a crosslinking agent such as a polyfunctional amine is used in addition to the polysuccinimide and monoamine in the ring-opening reaction of the polysuccinimide. The order of addition of the crosslinking agent and monoamine is not particularly limited. The monoamine may be added first and then the crosslinking agent, or the monoamine and crosslinking agent may be added simultaneously, or the crosslinking agent may be added first and then the monoamine. From the viewpoint of easy control of the crosslinking amount, it is preferable to add the crosslinking agent first and then add the monoamine after the crosslinking reaction has progressed. The order of addition of amine A and amine B is also not particularly limited. For example, amine A may be added first and then amine B, or amine A and amine B may be added simultaneously, or amine B may be added first and then amine A.

[0061] Specifically, when a polyfunctional amine is used as a crosslinking agent, a method for producing a polyaspartic acid derivative may be mentioned in which, if necessary, polysuccinimide is reacted with the crosslinking agent to form a crosslinked structure, and then the crosslinked structure is reacted with a monoamine to open the imide ring of the polysuccinimide. The total amount of the crosslinking agent and monoamine used may be less than 1 molar equivalent relative to the molar equivalent of the monomer unit of polysuccinimide, so that unreacted imide rings may remain, or may be 1 molar equivalent or more, so that no unreacted imide rings may remain.

[0062] The unreacted imide ring may remain as it is, or may be opened by reaction with a primary or secondary monoamine other than amine A and amine B (for example, a substituted amine such as cysteamine or dibutylamine).

[0063] In the method for producing a polyaspartic acid derivative, the amount of amine A charged relative to the amount of polysuccinimide charged is preferably 40 mol% or more, more preferably 43 mol% or more, and even more preferably 45 mol% or more. On the other hand, the amount of amine A charged relative to the amount of polysuccinimide charged is preferably 60 mol% or less, more preferably 58 mol% or less, and even more preferably 57 mol% or less. Specifically, the amount of amine A charged relative to the amount of polysuccinimide charged is, for example, 40 mol% to 60 mol%, 43 mol% to 58 mol%, or 45 mol% to 57 mol%.

[0064] In the method for producing a polyaspartic acid derivative, the amount of amine B charged relative to the amount of polysuccinimide charged is preferably 30 mol% or more, more preferably 32 mol% or more, and even more preferably 35 mol% or more. On the other hand, the amount of amine B charged relative to the amount of polysuccinimide charged is preferably 60 mol% or less, more preferably 50 mol% or less, and even more preferably 45 mol% or less. Specifically, the amount of amine B charged relative to the amount of polysuccinimide charged is, for example, 30 mol% to 60 mol%, 32 mol% to 50 mol%, or 35 mol% to 45 mol%.

[0065] In the method for producing a polyaspartic acid derivative, the amount of crosslinking agent charged relative to the amount of polysuccinimide charged is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, and even more preferably 0.5 mol% or more. On the other hand, the amount of crosslinking agent charged relative to the amount of polysuccinimide charged is preferably 2.0 mol% or less, more preferably 1.8 mol% or less, and even more preferably 1.7 mol% or less. The ratio of the amount of polysuccinimide charged relative to the amount of crosslinking agent charged is specifically, for example, 0.1 mol% to 2.0 mol%, 0.3 mol% to 1.8 mol%, or 0.5 mol% to 1.7 mol%.

[0066] In the method for producing a polyaspartic acid derivative, a primary or secondary monoamine other than amine A and amine B (hereinafter also referred to as "other monoamine") may be used. In this case, the total amount of amine A and amine B relative to the total amount of amine A, amine B, and other monoamines is preferably 80.0 mol% or more, more preferably 90.0 mol% or more, and even more preferably 95.0 mol% or more. On the other hand, the total amount of amine A and amine B relative to the total amount of amine A, amine B, and other monoamines is less than 100.0 mol%. Other monoamines include, for example, substituted amines such as cysteamine and dibutylamine.

[0067] The total amount of amine A, amine B, and other monoamines to be charged is not particularly limited as long as they are substantially soluble in the organic solvent and / or do not substantially inhibit the progress of the reaction. The amount is generally 0.1 or more molar equivalents relative to the molar equivalents of the monomer units of polysuccinimide. On the other hand, the amount is generally 10 or less molar equivalents relative to the molar equivalents of the monomer units of polysuccinimide, preferably 1.2 or less molar equivalents. Specifically, the amount to be charged relative to the molar equivalents of the monomer units of polysuccinimide is, for example, 0.1 to 10 molar equivalents, preferably 0.1 to 1.2 molar equivalents.

[0068] In the method for producing a polyaspartic acid derivative, the molar ratio of the amount of amine A charged to the amount of amine B charged is preferably 45 / 55 to 60 / 40, and more preferably 50 / 50 to 60 / 40.

[0069] [Organic solvent] In the method for producing a polyaspartic acid derivative, the organic solvents used in the crosslinking reaction and the ring-opening reaction are not particularly limited as long as they substantially dissolve the polysuccinimide, the crosslinking agent, and the monoamine and / or do not substantially inhibit the progress of the reaction. The organic solvents may be used alone or in combination of two or more. In the present disclosure, the term "organic solvent" does not include amine A, amine B, other monoamines, or the basic catalyst described below.

[0070] The organic solvent may be an aprotic polar organic solvent, a protic polar organic solvent, or a mixed solvent of these in any ratio, but preferably contains an aprotic polar organic solvent. That is, the organic solvent is preferably an aprotic polar organic solvent or a mixed solvent of an aprotic polar organic solvent and a protic polar organic solvent. Specific examples of aprotic polar organic solvents include dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylimidazolidinone (DMI), dimethyl sulfoxide (DMSO), sulfolane, etc., and preferably DMF or NMP. Specific examples of protic polar organic solvents include monohydric alcohols having 1 to 5 carbon atoms, such as methanol, ethanol, n-propanol, and isopropanol; dihydric alcohols having 1 to 8 carbon atoms, such as butylene glycol, propylene glycol, ethylene glycol, and dibutylene glycol; trihydric alcohols having 1 to 8 carbon atoms, such as glycerin; sterols, such as cholesterol, sitosterol, phytosterol, and lanosterol; monosaccharides (for example, pentoses, such as ribose, arabinose, and xylose; hexoses, such as glucose, galactose, and fructose); and sugar alcohols, such as sorbitol, xylitol, and maltitol; and the like, with monohydric alcohols having 1 to 5 carbon atoms being preferred.

[0071] [Basic catalyst] In the method for producing a polyaspartic acid derivative, the ring-opening reaction may be carried out without using a catalyst, or may be carried out with a catalyst such as a basic catalyst. The optional basic catalyst is not particularly limited as long as it substantially accelerates the reaction rate. However, in this disclosure, the term "basic catalyst" does not include amine A, amine B, and other monoamines. Specific examples of the basic catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, diisopropylethylamine (DIEA), triethanolamine, and triethylenediamine (DABCO); alicyclic tertiary amines such as N-methylmorpholine; aromatic tertiary amines such as dimethylaniline and diethylaniline; and guanidine compounds such as tetramethylguanidine. The basic catalysts may be used alone or in combination of two or more.

[0072] In the method for producing a polyaspartic acid derivative, the amount of the basic catalyst used in the ring-opening reaction is not particularly limited as long as it substantially accelerates the reaction rate. The amount of the basic catalyst used is generally 0 to 2 molar equivalents relative to the molar equivalent of the total amount of monoamines charged.

[0073] [Reaction temperature] In the method for producing a polyaspartic acid derivative, the reaction temperature is not particularly limited as long as the reaction can be substantially maintained. The reaction temperature is generally selected from a temperature range of 5 to 150° C. The reaction temperature can be optimally selected from the viewpoints of the monoamine used, shortening the reaction time, improving the reaction rate, etc. The method for producing a polyaspartic acid derivative preferably includes a crosslinking reaction step in which a crosslinking agent is added first to promote the crosslinking reaction, and a ring-opening reaction step in which a monoamine is added to promote the ring-opening reaction. In this case, the temperature of the crosslinking reaction and the temperature of the monoamine reaction may be the same or different. The temperature of the crosslinking reaction is preferably lower than the reaction temperature after the addition of the monoamine. In the crosslinking reaction step in which a crosslinking agent is added to polysuccinimide to promote the crosslinking reaction, the reaction temperature may be 120°C or lower, or may be 100°C or lower. The reaction temperature in the crosslinking reaction step may be 20°C or higher. Specifically, the reaction temperature in the crosslinking reaction step may be, for example, 20°C to 120°C or 20°C to 100°C. Furthermore, when the crosslinking agent is an ether-based diamine or tris(2-aminoalkyl)amine, the reaction temperature in the crosslinking reaction step is preferably 100°C or lower, more preferably 80°C or lower, even more preferably 60°C or lower, and may be 50°C or lower. The reaction temperature in the crosslinking reaction step may be 20°C or higher. The reaction temperature in the crosslinking reaction step may be, for example, 20°C to 100°C, 20°C to 80°C, 20°C to 60°C, or 20°C to 50°C. In the crosslinking reaction step, as long as the reaction temperature is within the above range, crosslinking can proceed uniformly. By the above production method, a polyaspartic acid derivative with high viscosity can be obtained.

[0074] [Concentration of reaction system] The concentration of the reaction system employed in the method for producing a polyaspartic acid derivative is not particularly limited as long as it can substantially maintain the progress of the reaction. The concentration of the reaction system is selected based on the concentration of polysuccinimide, and the polysuccinimide concentration is generally selected from a concentration range of 1 to 50% by weight. The concentration of the reaction system can also be selected from a polysuccinimide concentration range of 1 to 50% by weight to be optimal for the monoamine used.

[0075] [Method for isolating polyaspartic acid derivatives] In the method for producing a polyaspartic acid derivative, the method for isolating the polymer produced from the reaction solution after the reaction is completed is not particularly limited as long as it can isolate the reaction product with the desired purity. The isolation method may be any known or commonly used method. Generally, known or commonly used isolation procedures such as concentration, recrystallization, or reprecipitation are used.

[0076] A specific example of the isolation method is a method in which, after completion of the reaction, an excess of a poor solvent (e.g., ethyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.) is added to the reaction solution in which the reaction product is dissolved at an appropriate temperature, the precipitated reaction product is isolated by decantation, filtration, suction filtration, etc., and the crystals are thoroughly washed with a poor solvent that does not dissolve the crystals, followed by drying. Another specific example is a method in which, after completion of the reaction, the reaction solution in which the reaction product is dissolved is added to an excess of the same poor solvent as above at an appropriate temperature, and the precipitated reaction product is isolated, washed, and dried in the same manner as above.

[0077] In the method for producing a polyaspartic acid derivative, the resulting polyaspartic acid derivative may not be isolated, and the post-reaction mixture may be used as is as the polyaspartic acid derivative. Alternatively, if necessary, only some of the unreacted raw materials other than the solvent may be removed and incorporated into the composition of the present disclosure. Alternatively, the solvent in the mixture may be increased or decreased to adjust the concentration and produce a polyaspartic acid derivative.

[0078] <Polyaspartic acid derivative content> The content of the polyaspartic acid derivative relative to the total weight of the composition of the present disclosure is not particularly limited and can be adjusted appropriately depending on the purpose, but is preferably 0.1 wt% or more, more preferably 0.15 wt% or more, even more preferably 0.2 wt% or more, even more preferably 0.5 wt% or more, and even more preferably 1.0 wt% or more. On the other hand, the content of the polyaspartic acid derivative relative to the total weight of the composition is preferably 2.0 wt% or less, more preferably 1.8 wt% or less, and even more preferably 1.5 wt% or less. Specifically, the content of the polyaspartic acid derivative relative to the total weight of the composition is, for example, 0.1 wt% to 2.0 wt%, 0.15 wt% to 2.0 wt%, 0.2 wt% to 1.8 wt%, 0.5 wt% to 1.5 wt%, or 1.0 wt% to 1.5 wt%.

[0079] The composition of the present disclosure has an oil-in-water (O / W) emulsion structure, i.e., a structure in which an oil phase (O phase) is encapsulated in a water phase (W phase). In the present disclosure, the aqueous phase is generally composed of water and an aqueous component, where the aqueous component may be any component that dissolves in water at 25 to 65°C. In the present disclosure, the oil phase is typically composed of an oily component. Here, the oily component is typically an oily agent, but is not limited thereto, and may also include a component that undergoes phase separation from water after being suspended in water at 25 to 65°C and left to stand for 1 hour.

[0080] [Oily ingredients] The composition of the present disclosure contains an oily component. The oily component is not particularly limited, and any known oily component can be used. The oily component may be any component that is liquid, solid, or semi-solid at room temperature. Examples of oily components include hydrocarbons, higher alcohols, higher fatty acids, esters, silicone oils, and vegetable oils. One type of oily component may be used alone, or two or more types may be used in combination. In this disclosure, "higher alcohol" refers to an alcohol having 6 or more carbon atoms, while "lower alcohol" refers to an alcohol having 5 or fewer carbon atoms. In this disclosure, "higher fatty acid" refers to a fatty acid having 8 or more carbon atoms.

[0081] Examples of hydrocarbons include squalane, mineral oil, liquid paraffin, light isoparaffin, dodecane, tetradecane, ozokerite, microcrystalline wax, ceresin, α-olefin oligomer, polybutene, hydrogenated polyisoparaffin, limonene, turpentine, and petrolatum.

[0082] Examples of higher alcohols include: linear or branched alcohols having 8 to 24 carbon atoms, such as coconut oil alcohol, capryl alcohol, capric alcohol, lauryl alcohol, isostearyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol, arachyl alcohol, behenyl alcohol, oleyl alcohol, isostearyl alcohol, hexyldecanol, 2-octyldodecanol, decyltetradecanol, and batyl alcohol; sterols such as cholesterol and phytosterols;

[0083] Examples of higher fatty acids include those having 8 to 24 carbon atoms, such as coconut oil fatty acid, isostearic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, undecylenic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, oxystearic acid, palmitoleic acid, ricinoleic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), isostearic acid, and 12-hydroxystearic acid.

[0084] Examples of esters include: Esters of straight-chain fatty acids and lower alcohols, such as isopropyl myristate, isopropyl palmitate, and ethyl oleate; Esters of straight-chain fatty acids and straight-chain higher alcohols, such as hexyl laurate, myristyl myristate, decyl oleate, stearyl stearate, and cetyl palmitate; Esters of straight-chain fatty acids and branched alcohols, such as octyldodecyl myristate, isostearyl palmitate, ethylhexyl stearate, and ethylhexyl palmitate; Esters of branched fatty acids with lower alcohols, such as ethyl isostearate and isopropyl isostearate; Esters of branched fatty acids with linear higher alcohols, such as cetyl ethylhexanoate and hexyl isostearate; Esters of fatty acids and polyhydric alcohols such as PG dicaprylate, triethylhexanoin, and tri(caprylic / capric)glyceryl; Esters of branched fatty acids and branched alcohols, such as 2-octyldodecyl neopentanoate and isostearyl isostearate; Esters of hydroxycarboxylic acids with alcohols, such as lauryl lactate, trioctyldodecyl citrate, and diisostearyl malate; ester oils such as esters of dibasic acids such as diisopropyl adipate and diethyl sebacate; Wax esters such as jojoba butter, carnauba wax, candelilla wax, rice bran wax, beeswax, montan wax, sugarcane wax, and palm wax;

[0085] Examples of silicone oils include dimethylpolysiloxane, methylphenylpolysiloxane, dodecamethylcyclohexasiloxane, methylhydrogenpolysiloxane, and dimethylsiloxane. The kinematic viscosity of the silicone oil at 25°C is not particularly limited and can be selected appropriately depending on the purpose. 2 / s or less is preferable, 50 mm 2 / s or less is more preferable.

[0086] Examples of vegetable oils include apricot kernel oil, camellia oil, argan oil, soybean oil, olive oil, castor oil, coconut oil, palm oil, palm kernel oil, sesame oil, perilla oil, jojoba seed oil, cottonseed oil, rapeseed oil, linseed oil, rosehip oil, sunflower oil, essential oils, avocado oil, almond oil, rice bran oil, safflower oil, corn oil, grapeseed oil, coconut oil, Argania spinosa kernel oil, wheat germ oil, rice germ oil, kukui nut oil, crambe abyssinica seed oil, hemp seed oil, peanut oil, camellia oil, evening primrose oil, pistachio oil, macadamia nut oil, meadowholm oil, cocoa butter, shea butter, and Japan wax oil.

[0087] The oily component is preferably one or more selected from the group consisting of hydrocarbons, higher alcohols, esters, silicone oils, and vegetable oils.

[0088] The content of the oily component relative to the total weight of the composition of the present disclosure is not particularly limited, but is preferably 1.0 wt% or more, more preferably 5.0 wt% or more, even more preferably 10.0 wt% or more, even more preferably 15.0 wt% or more, and even more preferably 17.0 wt% or more. On the other hand, the content of the oily component relative to the total weight of the composition is preferably 50.0 wt% or less, more preferably 40.0 wt% or less, even more preferably 35.0 wt% or less, even more preferably 30.0 wt% or less, and even more preferably 25.0 wt% or less. Specifically, the content of the oily component relative to the total weight of the composition is, for example, 1.0 wt% to 50.0 wt%, 5.0 wt% to 40.0 wt%, 10.0 wt% to 35.0 wt%, 15.0 wt% to 30.0 wt%, or 17.0 wt% to 25.0 wt%.

[0089] [water] The compositions of the present disclosure include water. The water content relative to the total weight of the composition of the present disclosure is preferably 40.0 wt% or more, more preferably 45.0 wt% or more, even more preferably 50.0 wt% or more, even more preferably 55.0 wt% or more, even more preferably 60.0 wt% or more, and even more preferably 65.0 wt% or more. On the other hand, the water content relative to the total weight of the composition is preferably 90.0 wt% or less, more preferably 85.0 wt% or less, even more preferably 80.0 wt% or less, even more preferably 75.0 wt% or less, and even more preferably 70.0 wt% or less. Specifically, the water content relative to the total weight of the composition is, for example, 40.0 wt% to 90.0 wt%, 45.0 wt% to 85.0 wt%, 50.0 wt% to 80.0 wt%, 55.0 wt% to 75.0 wt%, 60.0 wt% to 70.0 wt%, or 65.0 wt% to 70.0 wt%.

[0090] [emulsifier] The composition of the present disclosure preferably contains an emulsifier. Here, "emulsifier" refers to an emulsifier other than a polyaspartic acid derivative. The emulsifier is not particularly limited, and examples thereof include one or more surfactants selected from the group consisting of anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. One type of emulsifier may be used alone, or two or more types may be used in combination.

[0091] Anionic surfactants include: Fatty acid soaps such as potassium coconut oil fatty acids (e.g., potassium cocoyl glutamate), potassium myristate, and potassium laurate; Alkyl sulfates such as potassium lauryl sulfate, sodium lauryl sulfate, triethanolamine lauryl sulfate, and sodium myristyl sulfate; Sodium polyoxyethylene lauryl ether sulfate, such as sodium POE(2) lauryl ether sulfate; Polyoxyethylene alkyl ether sulfates such as polyoxyethylene lauryl ether sulfate triethanolamine; alkyl phosphates such as lauryl phosphate; Amino acid surfactants such as acylmethyl taurate and sodium lauroylmethyl alanine; Sulfonates such as sodium lauryl sulfoacetate; and the like.

[0092] Examples of cationic surfactants include: Alkylammonium salts such as cetyltrimethylammonium chloride, stearyltrimethylammonium chloride (steartrimonium chloride), behenyltrimethylammonium chloride, lauryltrimethylammonium chloride, stearoxypropyltrimonium chloride, and quaternium-33; Alkylbenzylammonium salts; Stearylamine Acetate; Polyoxyethylene alkylamines such as polyoxyethylene laurylamine and polyoxyethylene stearylamine; Stearamidopropyl dimethylamine; benzalkonium chloride; and the like.

[0093] Nonionic surfactants include: Polyoxyethylene sorbitan fatty acid esters such as POE(20) sorbitan monolaurate, POE(20) sorbitan monopalmitate, POE(6) sorbitan monostearate, POE(20) sorbitan monostearate, POE(20) sorbitan tristearate, POE(6) sorbitan monooleate, POE(20) sorbitan monooleate, POE(20) sorbitan trioleate, and POE(20) sorbitan monoisostearate; polyethylene glycol fatty acid esters such as POE(10) monostearate, POE(25) monostearate, POE(40) monostearate, POE(55) monostearate, POE(10) monolaurate, POE(10) monooleate, and PEG-20 sorbitan cocoate; Polyoxyethylene alkyl ethers such as POE(4) lauryl ether, POE(9) lauryl ether, POE(21) ​​lauryl ether, POE(150) cetyl ether, POE(20) cetyl ether, POE(2) cetyl ether, POE(10) cetyl ether, POE(25) cetyl ether, POE(30) cetyl ether, POE(10) oleyl ether, POE(15) oleyl ether, POE(7) oleyl ether, POE(20) oleyl ether, POE(50) oleyl ether, POE(5) behenyl ether, POE(10) behenyl ether, POE(20) behenyl ether, POE(30) behenyl ether, and POE(20) stearyl ether; Polyoxyethylene polyoxypropylene alkyl ethers such as POE(20)POP(4) cetyl ether, POE(20)POP(8) cetyl ether, and POE(30)POP(6) decyltetradecyl ether; Polyoxyethylene sorbitol fatty acid esters such as POE(60) sorbitol tetrastearate, POE(6) sorbitol tetraoleate, POE(30) sorbitol tetraoleate, POE(60) sorbitol tetraoleate, and POE(6) sorbitol monolaurate; Polyoxyethylene glycerin fatty acid esters such as PEG-20 glyceryl triisostearate, PEG-7 glyceryl coconut oil fatty acid, POE(15) glyceryl monostearate, POE(5) glyceryl monostearate, and POE(15) glyceryl monooleate; Polyoxyethylene castor oils and hydrogenated castor oils such as POE(40) castor oil, POE(20) hydrogenated castor oil, POE(40) hydrogenated castor oil, POE(50) hydrogenated castor oil, POE(60) castor oil, POE(60) hydrogenated castor oil, POE(80) hydrogenated castor oil, and POE(100) hydrogenated castor oil; Polyoxyethylene lanolin alcohols such as POE(10) lanolin alcohol, POE(20) lanolin alcohol, and POE(40) lanolin alcohol; Sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquistearate, sorbitan monooleate, sorbitan sesquioleate, and sorbitan trioleate; glycerin fatty acid esters such as glyceryl monooleate, glyceryl monostearate, and glyceryl monomyristate; Diglycerol fatty acid esters such as diglyceryl monostearate, diglyceryl monooleate, diglyceryl monoisostearate, etc.; triglycerol fatty acid esters such as triglyceryl monolaurate, triglyceryl monomyristate, triglyceryl monooleate, triglyceryl monostearate, etc.; tetraglycerol fatty acid esters such as tetraglyceryl monostearate, tetraglyceryl monooleate, etc.; pentaglycerol fats such as pentaglyceryl trimyristate, pentaglyceryl trioleate, pentaglyceryl monolaurate, pentaglyceryl monomyristate, pentaglyceryl monooleate, pentaglyceryl monostearate, etc. fatty acid esters, hexaglycerin fatty acid esters such as hexaglyceryl monooleate, hexaglyceryl monostearate, hexaglyceryl tristearate, hexaglyceryl monolaurate, hexaglyceryl monomyristate, etc., and decaglycerin fatty acid esters such as decaglyceryl monostearate, decaglyceryl distearate, decaglyceryl diisostearate, decaglyceryl dioleate, decaglyceryl tristearate, decaglyceryl trioleate, decaglyceryl monolaurate, decaglyceryl monomyristate, decaglyceryl monooleate, decaglyceryl distearate, etc., polyglycerin fatty acid esters; alkyl glucosides such as lauryl glucoside; Fatty acid alkylolamides such as coconut oil fatty acid N-methylethanolamide and coconut oil fatty acid diethanolamide; alkyldimethylamine oxide liquids such as lauryldimethylamine oxide liquid; and the like.

[0094] Amphoteric surfactants include: betaine-type compounds such as alkyl betaines such as lauryl dimethylaminoacetic acid betaine (lauryl betaine), stearyl betaine, lauric acid amidopropyl betaine, lauryl hydroxysulfobetaine, stearyl dimethylaminoacetic acid betaine, dodecyl aminomethyl dimethyl sulfopropyl betaine, and octadecyl aminomethyl dimethyl sulfopropyl betaine; and fatty acid amidopropyl betaines such as coconut acid amidopropyl betaine, coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine (cocamidopropyl betaine), and cocamidopropyl hydroxysultaine; Alkyl imidazole type such as 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine; Amine oxide types such as lauryl dimethylamine N-oxide, oleyl dimethylamine N-oxide, and lauramine oxide; Examples of lecithins include egg yolk lecithin, soybean lecithin, hydroxide lecithin, and hydrogenated lecithin.

[0095] The emulsifier is preferably one or more selected from the group consisting of nonionic surfactants and amphoteric surfactants. The nonionic surfactant is more preferably one or more selected from the group consisting of polyglycerin fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters, and is also preferably one or more selected from the group consisting of polyglycerin fatty acid esters and glycerin fatty acid esters, one or more selected from the group consisting of polyglycerin fatty acid esters and sorbitan fatty acid esters, or one or more selected from the group consisting of glycerin fatty acid esters and sorbitan fatty acid esters. The amphoteric surfactant is more preferably lecithin. Lecithin may be hydrogenated (hydrogenated lecithin).

[0096] The degree of polymerization of the polyglycerol fatty acid ester is preferably 8 or more, more preferably 9 or more, while the degree of polymerization of the polyglycerol fatty acid ester is preferably 12 or less, more preferably 11 or less. Specifically, the degree of polymerization of the polyglycerol fatty acid ester is, for example, 8 to 12 or 9 to 11. The fatty acid of the polyglycerol fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid, and may be branched or linear. The number of carbon atoms in the fatty acid of the polyglycerol fatty acid ester is preferably 12 or more, more preferably 14 or more, even more preferably 16 or more, and still more preferably 17 or more, while the number of carbon atoms in the fatty acid of the polyglycerol fatty acid ester is preferably 20 or less, more preferably 19 or less. Specifically, the number of carbon atoms in the fatty acid of the polyglycerol fatty acid ester is, for example, 12 to 20, 14 to 19, 16 to 20, or 17 to 19.

[0097] The fatty acid of the glycerin fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid, and may be branched or linear. The number of carbon atoms in the fatty acid of the glycerin fatty acid ester is preferably 16 or more, more preferably 17 or more, while the number of carbon atoms in the fatty acid of the glycerin fatty acid ester is preferably 20 or less, more preferably 19 or less. Specifically, the number of carbon atoms in the fatty acid of the glycerin fatty acid ester is, for example, 16 to 20 or 17 to 19.

[0098] The fatty acid of the sorbitan fatty acid ester may be a saturated fatty acid or an unsaturated fatty acid, and may be branched or linear. The number of carbon atoms in the fatty acid of the sorbitan fatty acid ester is preferably 15 or more, more preferably 16 or more, while the number of carbon atoms in the fatty acid of the sorbitan fatty acid ester is preferably 19 or less, more preferably 18 or less. Specifically, the number of carbon atoms in the fatty acid of the sorbitan fatty acid ester is, for example, 15 to 19 or 16 to 18.

[0099] The content of the emulsifier relative to the total amount of the composition of the present disclosure is not particularly limited, but is preferably 0.5% by weight or more, more preferably 1.0% by weight or more, even more preferably 1.5% by weight or more, even more preferably 2.0% by weight or more, even more preferably 2.5% by weight or more, even more preferably 3.0% by weight or more, and even more preferably 3.5% by weight or more. On the other hand, the content of the emulsifier relative to the total amount of the composition is preferably 15.0% by weight or less, more preferably 13.0% by weight or less, even more preferably 10.0% by weight or less, even more preferably 7.0% by weight or less, even more preferably 5.0% by weight or less, and even more preferably 4.5% by weight or less. The content of the emulsifier relative to the total amount of the composition may be, specifically, for example, 0.5 to 15.0% by weight, 1.0 to 13.0% by weight, 1.5 to 10.0% by weight, 2.0 to 7.0% by weight, 2.5 to 5.0% by weight, 3.0 to 4.5% by weight, or 3.5 to 4.5% by weight.

[0100] The composition of the present disclosure can be produced by a conventional method. Specifically, the composition of the present disclosure is not particularly limited, but can be produced, for example, by the following method. First, an oily component, and optionally an emulsifier and optional ingredients, are mixed and dissolved under heating to prepare an oil phase. Separately, a polyaspartic acid derivative, water, and optionally an emulsifier and optional ingredients are mixed and dissolved under heating to prepare an aqueous phase. Next, the oil phase is gradually added to the prepared aqueous phase while stirring at 70°C to 85°C, and then emulsified by stirring and mixing at 4000 rpm to 8000 rpm for 30 seconds to 5 minutes using a known stirring device such as a homomixer, while heating as necessary. This allows the composition of the present disclosure to be produced.

[0101] The composition of the present disclosure, particularly in the form of a cream or emulsion, has an excellent feel when applied to the skin with the fingers, as it quickly disintegrates as if it were melting. Therefore, the composition of the present disclosure is preferably in the form of an external preparation for skin, and specifically, is suitable for use in the form of a cosmetic, a quasi-drug, or a pharmaceutical.

[0102] The use of the composition of the present disclosure is not particularly limited. The composition of the present disclosure can be suitably used, for example, in cleansing, emulsion, lotion, serum, makeup base, hair care, foundation, sunscreen, shaving cream, facial cleanser, facial cleanser, etc.

[0103] When applied as a skin external preparation, the dosage form may be any of the commonly known lotion, emulsion, essence, cream, powder-containing dosage forms, etc., with the cream or emulsion dosage form being particularly preferred.

[0104] [Optional ingredients] The composition of the present disclosure may optionally contain other components to the extent that the effects of the present disclosure are not significantly impaired. Such optional ingredients include those commonly used in external skin preparations such as cosmetics, quasi-drugs, pharmaceuticals, etc. Examples of such optional ingredients include the following:

[0105] Known thickeners include guar gum, quince seed, carrageenan, galactan, gum arabic, pectin, mannan, starch, xanthan gum, curdlan, methylcellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methylhydroxypropyl cellulose, chondroitin sulfate, dermatan sulfate, glycogen, heparan sulfate, hyaluronic acid, sodium hyaluronate, tragacanth gum, keratan sulfate, chondroitin, mucoitin sulfate, hydroxyethyl guar gum, carboxymethyl guar gum, dextran, keratosulfuric acid, locust bean gum, succinoglucan, caronic acid, chitin, chitosan, carboxymethyl chitin, agar, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, alkyl-modified carboxyvinyl polymer, sodium polyacrylate, polyethylene glycol, and bentonite.

[0106] Examples of powders include powders such as mica, talc, kaolin, synthetic mica, calcium carbonate, magnesium carbonate, anhydrous silicic acid (silica), aluminum oxide, and barium sulfate, which may be surface-treated; inorganic pigments such as red iron oxide, yellow iron oxide, black iron oxide, cobalt oxide, ultramarine, iron blue, titanium oxide, and zinc oxide, which may be surface-treated; pearling agents such as titanium dioxide, fish phosphate foil, and bismuth oxychloride, which may be surface-treated; Examples of the organic pigments include Red No. 202, Red No. 228, Red No. 226, Yellow No. 4, Blue No. 404, Yellow No. 5, Red No. 505, Red No. 230, Red No. 223, Orange No. 201, Red No. 213, Yellow No. 204, Yellow No. 203, Blue No. 1, Green No. 201, Purple No. 201, and Red No. 204, which may be methylated; and organic powders such as polyethylene powder, polymethyl methacrylate, nylon powder, and organopolysiloxane elastomer.

[0107] Examples of the ultraviolet absorber include para-aminobenzoic acid-based ultraviolet absorbers, anthranilic acid-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, cinnamic acid-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, sugar-based ultraviolet absorbers, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, and 4-methoxy-4'-t-butyldibenzoylmethane.

[0108] Other optional ingredients include alcohols (e.g., lower alcohols such as methanol, ethanol, and propanol; polyhydric alcohols such as glycerin, propylene glycol, butylene glycol, and dipropylene glycol), fragrances, preservatives (e.g., phenoxyethanol), antibacterial agents (e.g., ethylhexylglycerin and glyceryl caprylate), pH adjusters, and colorants.

[0109] The initial viscosity of the composition of the present disclosure is not particularly limited and can be adjusted appropriately depending on the purpose, but is preferably 2,000 mPa·s or more, more preferably 5,000 mPa·s or more, even more preferably 10,000 mPa·s or more, even more preferably 20,000 mPa·s or more, even more preferably 25,000 mPa·s or more, even more preferably 30,000 mPa·s or more, and even more preferably 40,000 mPa·s or more. On the other hand, the initial viscosity of the composition of the present disclosure is preferably 70,000 mPa·s or less, more preferably 60,000 Pa·s or less, even more preferably 55,000 mPa·s or less, and even more preferably 50,000 mPa·s or less. Specifically, the initial viscosity of the composition of the present disclosure is, for example, 2000 mPa·s to 70000 mPa·s, 5000 mPa·s to 60000 mPa·s, 10000 mPa·s to 55000 mPa·s, 20000 mPa·s to 70000 mPa·s, 25000 mPa·s to 60000 mPa·s, 30000 mPa·s to 55000 mPa·s, or 40000 mPa·s to 50000 mPa·s. The initial viscosity of the composition of the present disclosure can be adjusted by, for example, the content of the polyaspartic acid derivative, etc. in the composition of the present disclosure. In this disclosure, the term "initial viscosity" refers to the viscosity of the composition immediately after preparation. The initial viscosity of the composition of the present disclosure is measured 30 seconds after the start of measurement using a digital B-type viscometer ("Digital Viscometer DV2T" manufactured by Eiko Instruments Co., Ltd.) with an LV-4 rotor at a rotation speed of 6 rpm and a measurement temperature of 25°C.

[0110] The viscosity of the composition of the present disclosure after storage is not particularly limited, but is preferably 2,000 mPa·s or higher, more preferably 5,000 mPa·s or higher, even more preferably 10,000 mPa·s or higher, even more preferably 18,000 mPa·s or higher, even more preferably 20,000 mPa·s or higher, even more preferably 25,000 mPa·s or higher, even more preferably 30,000 mPa·s or higher, and even more preferably 35,000 mPa·s or higher. On the other hand, the viscosity of the composition of the present disclosure after storage is preferably 70,000 mPa·s or lower, more preferably 60,000 Pa·s or lower, even more preferably 55,000 mPa·s or lower, even more preferably 50,000 mPa·s or lower, and even more preferably 40,000 mPa·s or lower. Specifically, the viscosity of the composition of the present disclosure after storage is, for example, 2000 mPa·s to 70000 mPa·s, 5000 mPa·s to 60000 mPa·s, 10000 mPa·s to 55000 mPa·s, 18000 mPa·s to 70000 mPa·s, 20000 mPa·s to 60000 mPa·s, 25000 mPa·s to 55000 mPa·s, 30000 mPa·s to 50000 mPa·s, or 35000 mPa·s to 40000 mPa·s. The viscosity after storage can be adjusted by, for example, the content of the polyaspartic acid derivative or the like in the composition of the present disclosure. In this disclosure, the term "viscosity after storage" refers to the viscosity of the composition of the present disclosure after it has been left to stand for one month at 50°C. The viscosity of the composition of the present disclosure after storage is the measured value 30 seconds after the start of measurement using a digital B-type viscometer ("Digital Viscometer DV2T", manufactured by Eiko Instruments Co., Ltd.) with an LV-4 rotor at a rotation speed of 6 rpm and a measurement temperature of 25°C.

[0111] The viscosity retention of the composition of the present disclosure is not particularly limited, but is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, even more preferably 85% or more, even more preferably 90% or more, and even more preferably 95% or more. On the other hand, the viscosity retention of the composition of the present disclosure is preferably 120% or less, more preferably 100% or less. Specifically, the viscosity retention of the composition of the present disclosure is, for example, 70% to 120%, 70% to 100%, 75% to 100%, 80% to 100%, 85% to 100%, 90% to 100%, or 95% to 100%. The polyaspartic acid derivative allows for the production of an oil-in-water emulsion composition with excellent viscosity stability. In the present disclosure, "viscosity retention" refers to the ratio (%) of the viscosity (mPa·s) after storage to the initial viscosity (mPa·s). The closer the viscosity retention rate is to 100%, the higher the viscosity stability of the composition.

[0112] The volume-average median diameter (d50) of the emulsified particles in the composition of the present disclosure is not particularly limited, but is preferably 25.0 μm or less, more preferably 20.0 μm or less, even more preferably 15.0 μm or less, even more preferably 10.0 μm or less, even more preferably 5.0 μm or less, and even more preferably 3.0 μm or less. On the other hand, the volume-average median diameter (d50) of the emulsified particles in the composition of the present disclosure is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 1.2 μm or more, even more preferably 1.5 μm or more, and even more preferably 2.0 μm or more. Specifically, the median diameter (d50) of the emulsified particles in the composition of the present disclosure, calculated as a volume average, is, for example, 0.5 μm to 25.0 μm, 0.5 μm to 20.0 μm, 0.5 μm to 15.0 μm, 1.0 μm to 10.0 μm, 1.0 μm to 5.0 μm, 1.2 μm to 3.0 μm, 1.5 μm to 25.0 μm, or 2.0 μm to 20.0 μm. The number-average median diameter (d50) of the emulsified particles in the composition of the present disclosure is not particularly limited, but is preferably 2.0 μm or less, more preferably 1.5 μm or less, even more preferably 1.0 μm or less, even more preferably 0.7 μm or less, even more preferably 0.5 μm or less, and even more preferably 0.1 μm or less. On the other hand, the number-average median diameter (d50) of the emulsified particles in the composition of the present disclosure is preferably 0.0001 μm or more, more preferably 0.0005 μm or more, even more preferably 0.001 μm or more, even more preferably 0.002 μm or more, even more preferably 0.01 μm or more, and even more preferably 0.02 μm or more. Specifically, the number-average median diameter (d50) of the emulsified particles in the composition of the present disclosure is, for example, 0.0001 μm to 2.0 μm, 0.0001 μm to 1.5 μm, 0.0005 μm to 1.0 μm, 0.001 μm to 0.7 μm, 0.001 μm to 0.5 μm, 0.002 μm to 0.1 μm, 0.01 μm to 2.0 μm, or 0.02 μm to 0.7 μm. The volume-average median diameter of the emulsified particles and the number-average median diameter of the emulsified particles can each be adjusted by the type and amount of each component contained in the composition of the present disclosure, the emulsification conditions (stirring conditions) during production of the composition of the present disclosure, etc. In the present disclosure, the median diameter is the median diameter calculated on a volume-average basis or a number-average basis using a laser diffraction particle size distribution analyzer ("SALD-7000", manufactured by Shimadzu Corporation). [Example]

[0113] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited thereto.

[0114] [Reference example 1] Polyaspartic acid derivative 1 was prepared by the following procedure.

[0115] <Synthesis of Polysuccinimide (PSI)> 160 parts of aspartic acid (YIXING QIANCHENG BIO-ENGINEERING Co., Ltd., 99.97% purity) and 83 parts of 85% phosphoric acid were mixed in a mortar, transferred to a tray, and reacted at 190°C and 1.3 kPa for 6 hours. The reaction mixture was pulverized, washed with distilled water until the filtrate became neutral, and then vacuum dried at 80°C to obtain 115 parts of a PSI powder with a weight-average molecular weight of 80,000.

[0116] <Synthesis of polyaspartic acid derivative 1> 10.0 g of PSI and 95.3 g of dimethylformamide (DMF) were placed in a reaction vessel and heated to 60°C until the PSI was completely dissolved. After the resulting PSI solution was cooled to 40°C, a mixture of 0.229 g of 1,2-bis(2-aminoethoxy)ethane (AEE; crosslinking agent) (1.5 mol % relative to 1 succinimide unit) and 2.06 g of DMF was added to the PSI solution and allowed to react for 7 hours. Next, 10.3 g of Farmin 20D (amine A; a mixture of 1% decylamine, 96% dodecylamine, and 3% tetradecylamine; manufactured by Kao Corporation) (54 mol % relative to 1 succinimide unit) was added to the reaction solution and allowed to react for 30 minutes. Furthermore, 3.45 g of 3-amino-1-propanol (amine B; 44.5 mol% relative to one succinimide unit) was added to the reaction solution, and the reaction was carried out for 7 hours while maintaining the temperature inside the reaction vessel at 60°C. The reaction vessel was then cooled to room temperature and allowed to stand overnight. The reaction solution was then poured into 1,200 mL of ethyl acetate with stirring to precipitate the reactant, and the solid was recovered by filtration. The recovered solid was then washed in 600 mL of ethyl acetate with stirring and recovered by filtration. The recovered solid was dried at 60°C under reduced pressure for 12 hours, yielding 22.0 g of polyaspartic acid derivative 1 with a weight-average molecular weight of 145,000.

[0117] (Measurement of weight-average molecular weight of PSI and polyaspartic acid derivative 1) The weight-average molecular weight of PSI was measured using a GPC method (differential refractometer) in terms of polystyrene. A G1000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), a G4000HHR column (TSKgel (registered trademark), manufactured by Tosoh Corporation), or a GMHHR-H column (TSKgel (registered trademark), manufactured by Tosoh Corporation) was used for the measurement. Dimethylformamide containing 10 mM lithium bromide was used as the eluent. The weight-average molecular weight of polyaspartic acid derivative 1 was also measured using the same method.

[0118] (Calculation of composition ratio and hydroxyl value of polyaspartic acid derivative 1) first, 1 The composition ratio (molar ratio) of polyaspartic acid derivative 1 was calculated using H-NMR. 1 H-NMR measurement conditions: A measurement sample was prepared by dissolving 0.1 g of polyaspartic acid derivative 1 in 0.6 mL of deuterated dimethyl sulfoxide, and measured using a JNM-ECZ400S (manufactured by JEOL Ltd.) under the following conditions. Observation frequency: 400MHz Chemical shift reference: TMS (tetramethylsilane) (0 ppm) Pulse Delay: 6.8 seconds Number of scans: 16 Pulse width: 45° (3.2 μs) Measurement temperature: 60℃

[0119] The composition ratio (mol %) of the polyaspartic acid derivative 1 was 1 Using the H-NMR spectrum, the calculation was performed using the following formula: Ratio of the content (mol%) of monomer units AU to the content (mol%) of monomer units BU (AU) / (BU)=(peak integral value of methyl groups derived from amine A / 3) / (peak integral value of methylene groups derived from amine B / 2) Ratio of the total content (mol%) of monomer units AU and BU to the content (mol%) of monomer unit CU [(AU) + (BU)] / (CU) = [(peak integral value of methyl group derived from amine A / 3) + (peak integral value of methylene group derived from amine B / 2)] / (peak integral value of methine group of succinimide monomer unit)

[0120] Next, the contents (mol %) of the monomer units AU and BU were calculated from the following formula, and the hydroxyl value was calculated based on the calculated values. Content of monomer unit AU (mol%)=(charge amount of amine A (mol%) / charge amount of PSI (mol%))×100 Content of monomer unit BU (mol%)=(charged amount of amine B (mol%) / charged amount of PSI (mol%))×100 Hydroxyl value = (charge amount of BU (mol%) / 100) × 56.11 × 1000 / [97 + molecular weight of crosslinking agent × (charge amount of crosslinking agent (mol%) / 100) + molecular weight of amine A × (charge amount of AU (mol%) / 100) + molecular weight of amine B × (charge amount of BU (mol%) / 100)] In the above formula, "charge amount (mol%) of amine A," "charge amount (mol%) of amine B," and "charge amount (mol%) of crosslinking agent" refer to the ratio of the charge amount (mol) of amine A, the charge amount (mol) of amine B, and the charge amount (mol) of crosslinking agent, respectively, to the charge amount (mol) of PSI. "PSI charge amount (moles)" refers to the weight of the PSI charge divided by the molecular weight of the repeating unit of PSI.

[0121] The (AU) / (BU) ratio calculated by the above method was 53 / 37, and [(AU)+(BU)] / (CU) was 90 / 7. The hydroxyl value of polyaspartic acid derivative 1 was 107 mgKOH / g.

[0122] [Reference example 2] <Synthesis of polyaspartic acid derivative 2> 21 g of polyaspartic acid derivative 2 having a weight-average molecular weight of 150,000 was obtained by the same procedure as in Reference Example 1, except that 10.7 g (54 mol % per succinimide unit) of Farmin CS (a mixture of coconut amine (7% octylamine, 7% decylamine, 51% dodecylamine, 19% tetradecylamine, 8% cetylamine, 2% stearylamine, and 6% oleylamine), manufactured by Kao Corporation) was used instead of Farmin 20D as amine A. The composition ratio of polyaspartic acid derivative 2 was (AU) / (BU) 58 / 39, and [(AU)+(BU)] / (CU) 97 / 2. The hydroxyl value of polyaspartic acid derivative 2 was 108 mgKOH / g. The weight average molecular weight, composition ratio, and hydroxyl value of polyaspartic acid derivative 2 were calculated using the same procedures as in Reference Example 1.

[0123] [Reference example 3] <Synthesis of polyaspartic acid derivative 3> 3.0 g of PSI and 16.8 g of N-methyl-2-pyrrolidone (NMP) were placed in a reaction vessel and heated at 130°C for 2 hours to completely dissolve the PSI. The resulting PSI solution was cooled to 80°C, and 1.68 g of ethanol was added dropwise to the PSI solution over 30 minutes while stirring. The reaction vessel was then cooled to 40°C, and 0.447 g of a 10 wt% NMP solution of 1,2-bis(2-aminoethoxy)ethane (AEE; crosslinker) (0.0447 g of AEE; a mixture of 1.0 mol% per mole of succinimide units and 0.403 g of NMP) was added to the PSI solution and allowed to react for 6 hours. The reaction vessel was then cooled to room temperature and allowed to stand overnight. Next, 6.7 g of a 50 wt % ethanol solution of Farmin 20D (amine A; a mixture of 1% decylamine, 96% dodecylamine, and 3% tetradecylamine; manufactured by Kao Corporation) (3.35 g of tetradecylamine; 52.0 mol % relative to 1 succinimide unit) was added to the reaction solution, and the mixture was allowed to react at 40°C for 4 hours. Furthermore, 1.383 g of 3-amino-1-propanol (amine B; 61.0 mol % relative to 1 succinimide unit) was added to the reaction solution, and the mixture was allowed to react at 40°C for 4 hours. The reaction vessel was then cooled to room temperature and allowed to stand overnight. The reaction solution was then poured into 300 g of ethyl acetate with stirring to precipitate the reactant, and the solid was collected by filtration. The collected solid was then washed in 150 g of ethyl acetate with stirring, and the solid was collected by filtration. The recovered solid was dried at 60° C. under reduced pressure for 12 hours to obtain 6.71 g of polyaspartic acid derivative 3 having a weight-average molecular weight of 332,000. The composition ratio of polyaspartic acid derivative 3 was (AU) / (BU) 57 / 43, and [(AU)+(BU)] / (CU) 94 / 6. The hydroxyl value of polyaspartic acid derivative 3 was 101 mgKOH / g. The weight average molecular weight, composition ratio, and hydroxyl value of polyaspartic acid derivative 3 were calculated using the same procedures as in Reference Example 1.

[0124] [Examples 1 to 4, Comparative Examples 1 and 2] The compositions (creams) of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared according to the following procedure. First, component A listed in Table 1 was heated to 80°C and mixed and dissolved. In a separate container, component B was heated to 80°C and mixed and dissolved. Next, component A was gradually added to component B while stirring at 70 to 80°C. The resulting mixture was then emulsified by stirring and mixing at 6,000 rpm using a homomixer for 1 minute. After emulsification, component C was added to the emulsion in Comparative Example 2, or component C was not added in Examples 1 to 4 and Comparative Example 1. The mixture was air-cooled to 40°C or below while stirring at 75 rpm using a paddle. Component D was then added to the cooled emulsion and mixed with stirring to obtain each composition (cream) with the composition shown in Table 1.

[0125] [Table 1]

[0126] [Examples 5 to 7, Comparative Examples 3 to 5] The compositions (milky lotions) of Examples 5 to 7 and Comparative Examples 3 to 5 were each prepared using the following procedure. Components A, B, and C listed in Table 2 were each heated to 85°C in separate containers and dissolved uniformly. Components A and B were mixed uniformly, and the mixture was gradually added to component C while stirring at 75 to 85°C. The mixture was emulsified by stirring using a homomixer at 6,000 rpm for 5 minutes. The resulting emulsion was air-cooled to 40°C or below while stirring at 150 rpm using a paddle, yielding each of the compositions (milky lotions) shown in Table 2.

[0127] [Table 2]

[0128] <Viscosity measurement (initial viscosity)> The viscosity (initial viscosity) of each of the compositions obtained in the Examples and Comparative Examples was measured using a digital Brookfield viscometer (Digital Viscometer DV2T, manufactured by Eiko Instruments Co., Ltd.) using an LV-4 rotor at a rotation speed of 6 rpm and a measurement temperature of 25°C, with the viscosity measured 30 seconds after the start of measurement.

[0129] <Viscosity measurement (viscosity after storage)> Each composition of the Examples and Comparative Examples was allowed to stand at 50° C. for one month, and then the viscosity of each composition (viscosity after storage) was measured using the same procedure as in measuring the initial viscosity.

[0130] <Calculation of viscosity retention rate> The ratio (%) of the viscosity (mPa·s) after storage to the initial viscosity (mPa·s) was calculated and used as the viscosity retention rate.

[0131] <Measurement of the median diameter of emulsion particles> For each of the compositions obtained in the Examples and Comparative Examples, the median diameter of the emulsified particles in terms of volume average was determined using a laser diffraction particle size distribution analyzer ("SALD-7000", manufactured by Shimadzu Corporation).

[0132] <Evaluation of texture> A panel of 10 experts applied each composition of the Examples and Comparative Examples to their faces and evaluated the feel of the composition as it quickly disintegrated on the skin, as if it were melting, according to the following criteria. A rating of C or higher was considered to be good. A: More than 8 out of 10 panelists answered that it felt like it was breaking down on the skin. B: Of the 10 panelists, between 5 and 8 answered that it felt like the cream was breaking down on the skin. C: Between 3 and 5 out of 10 panelists answered that they felt like the cream was breaking down on their skin. D: Less than 3 out of 10 panelists responded that it felt like the cream was breaking down on the skin.

[0133] The results are shown in Tables 1 and 2. When no polyaspartic acid derivative was contained (Comparative Examples 1 to 5), at least the initial viscosity was low or the median diameter of the emulsified particles was large, but when a polyaspartic acid derivative was contained (Examples 1 to 7), oil-in-water emulsion compositions were obtained that had a high initial viscosity and a small median diameter of the emulsified particles.

Claims

1. Contains a polyaspartic acid derivative and an oily component, The polyaspartic acid derivative comprises an α- or β-aspartic acid monomer unit A-U represented by the following general formula (1), an α- or β-aspartic acid monomer unit B-U represented by the following general formula (2), and an α- or β-aspartic acid monomer unit Crosslink-U represented by the following general formula (4), the content of the Crosslink-U monomer unit in the polyaspartic acid derivative is 0.1 mol % to 2.0 mol %; The oil-in-water emulsion composition, wherein the ratio (A-U) / (B-U) of the content (mol %) of the monomer units A-U to the content (mol %) of the monomer units B-U in the polyaspartic acid derivative is 40 / 60 to 60 / 40. 【Chemical 1】 (In the formula, R １ represents a hydrocarbon group having 3 to 22 carbon atoms. 【Chemistry 2】 (In the formula, R ２ represents a hydrocarbon group containing a heteroatom and having 1 to 20 carbon atoms. 【Chemistry 3】 (In the formula, the wavy lines indicate crosslinking sites.)

2. The polyaspartic acid derivative further contains a succinimide monomer unit C-U represented by the following formula (3):

2. The oil-in-water emulsion composition according to claim 1, wherein the ratio of the total content (mol %) of the monomer units A-U and B-U to the content (mol %) of the monomer units C-U in the polyaspartic acid derivative, [(A-U)+(B-U)] / (C-U), is 80 / 20 to 99 / 1. 【Chemistry 4】

3. 3. The oil-in-water emulsion composition according to claim 1, wherein the polyaspartic acid derivative has a hydroxyl value of 80 mg KOH / g to 170 mg KOH / g.

4. 3. The oil-in-water emulsion composition according to claim 1, wherein the content of the polyaspartic acid derivative is 0.1% by weight to 2.0% by weight based on the total amount of the oil-in-water emulsion composition.

5. The oil-in-water emulsion composition according to claim 1 or 2, further comprising an emulsifier.

6. 6. The oil-in-water emulsion composition according to claim 5, wherein the content of the emulsifier relative to the total amount of the oil-in-water emulsion composition is 0.5% by weight to 15.0% by weight.

7. 6. The oil-in-water emulsion composition according to claim 5, wherein the emulsifier is one or more selected from the group consisting of nonionic surfactants and amphoteric surfactants.

8. 8. The oil-in-water emulsion composition according to claim 7, wherein the nonionic surfactant is one or more selected from the group consisting of polyglycerin fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters.

9. 8. The oil-in-water emulsion composition according to claim 7, wherein the amphoteric surfactant is optionally hydrogenated lecithin.

10. 3. The oil-in-water emulsion composition according to claim 1, wherein the content of the oily component relative to the total amount of the oil-in-water emulsion composition is 1.0% by weight to 50.0% by weight.

11. 3. The oil-in-water emulsion composition according to claim 1, which is an external preparation for skin.

12. The oil-in-water emulsion composition according to claim 11, which is a cosmetic.

13. 12. The oil-in-water emulsion composition according to claim 11, which is a cream or a milky lotion.

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