1,3-Butylene glycol products

Abstract

To provide a 1,3-butylene glycol product that is less likely to generate apple odor and irritating odor even when incorporated into cosmetic compositions. [Solution] A 1,3-butylene glycol product having an area ratio of 10 or more and 280 or less, as shown by the following formula. Area ratio = Peak x Area / 1,3BG Peak Area × 10 6 Peak X area: In gas chromatography (GC) analysis under specific conditions, the area of ​​Peak X in the SIM mode m / z101 ion chromatogram where the relative retention time is in the range of 0.59 to 0.65, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0. 1,3BG peak area: In GC analysis under specific conditions, when the relative retention time of the peak of the same internal standard substance as above is set to 1.0, the area of ​​the 1,3-butylene glycol peak appearing in the range of relative retention time from 0.72 to 0.88 in the Scan mode m / z72 ion chromatogram.

Description

Technical Field

[0001] The present disclosure relates to 1,3-butylene glycol products. This application claims the priority of Japanese Patent Application No. 2024-114228 filed in Japan on July 17, 2024, the content of which is incorporated herein by reference.

Background Art

[0002] 1,3-Butylene glycol is a colorless, transparent, odorless liquid, with properties such as low volatility, low toxicity, and high hygroscopicity, and excellent chemical stability. Therefore, the uses of 1,3-butylene glycol cover a wide range, including raw materials for various synthetic resins and surfactants, as well as cosmetics, hygroscopic agents, high-boiling solvents, and materials for antifreeze fluids. In particular, in recent years, 1,3-butylene glycol has been noted for its excellent properties as a moisturizing agent, and the demand in the cosmetics industry has been expanding.

[0003] 1,3-Butylene glycol obtained by conventional manufacturing methods may have an odor due to the influence of by-products. Also, even if it is transparent immediately after production, it may become colored over time, which has been a problem when stored for a long period.

[0004] For example, when using cosmetics or during storage after use, the cosmetics will be exposed to air. Also, when manufacturing cosmetics, it is common to perform operations in an air atmosphere, and it may also be heated for purposes such as sterilization. When using 1,3-butylene glycol obtained by conventional methods in cosmetics, coloring may progress due to the presence of air or the influence of heating. To solve such problems, it has been required to remove by-products from crude 1,3-butylene glycol and purify 1,3-butylene glycol to a high purity.

[0005] As a method for obtaining high-purity 1,3-butylene glycol, a method has been proposed in which caustic soda is added to crude 1,3-butylene glycol obtained by hydrogenation of acetaldols and distilled. Another proposed method involves adding an alkali metal base to crude 1,3-butylene glycol from which high-boiling substances have been removed, heat-treating it, distilling off the 1,3-butylene glycol to separate the alkali metal compound and high-boiling substances as residues, and then distilling off the low-boiling substances from the 1,3-butylene glycol fraction (Patent Documents 1-9). In this way, various methods for producing high-purity 1,3-butylene glycol have been proposed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-258129 [Patent Document 2] International Publication No. 00 / 07969 [Patent Document 3] Japanese Patent Publication No. 2001-213822 [Patent Document 4] Japanese Patent Publication No. 2001-213824 [Patent Document 5] Japanese Patent Publication No. 2001-213825 [Patent Document 6] Japanese Patent Publication No. 2001-213828 [Patent Document 7] Patent No. 6804601 [Patent Document 8] Patent No. 6804602 [Patent Document 9] Patent No. 6979473 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the 1,3-butylene glycol products obtained by the methods described in Patent Documents 1 to 9 also had the problem of developing an odor (particularly an apple odor) over time when incorporated into cosmetic compositions. Although the reason for this is not clear, it is thought that certain by-products contained in the 1,3-butylene glycol products react with components contained in the cosmetic composition (e.g., citric acid, etc.) to form odor components, which contributes to the generation of the odor.

[0008] Furthermore, the inventors of this disclosure have found a 1,3-butylene glycol product that can solve the above problems by improving the manufacturing method of the 1,3-butylene glycol product. However, the inventors of this disclosure have revealed that the obtained 1,3-butylene glycol product also has the problem of generating an odor (pungent odor) different from the apple odor when incorporated into a cosmetic composition. This pungent odor does not occur in the 1,3-butylene glycol products described in Patent Documents 1 to 9, and is therefore considered to be an odor originating from the cosmetic composition itself. In addition, it is thought that a specific by-product contained in the 1,3-butylene glycol product has a masking effect on the pungent odor originating from the cosmetic composition, and that the pungent odor was suppressed by including a specific amount of this by-product. Thus, until now, no 1,3-butylene glycol product has been found that suppresses both the generation of the apple odor and the pungent odor when incorporated into a cosmetic composition.

[0009] Therefore, the object of this disclosure is to provide a 1,3-butylene glycol product that is less likely to generate apple odor and irritating odor even when incorporated into cosmetic compositions. [Means for solving the problem]

[0010] The inventors of this disclosure, through diligent research to achieve the above objectives, have found that by improving the method for producing crude 1,3-butylene glycol, a 1,3-butylene glycol product can be obtained that does not easily generate odors (apple odor and pungent odor) when incorporated into cosmetic compositions. The invention of this disclosure is completed based on these findings.

[0011] In other words, this disclosure provides a 1,3-butylene glycol product having an area ratio of 10 to 280 as shown by the following formula. Area ratio = Peak x Area / 1,3BG Peak Area × 10 6 Peak X Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​Peak X appearing in the SIM mode m / z101 ion chromatogram within the range of relative retention time of 0.59 to 0.65 is defined as the area of ​​Peak X. 1,3BG Peak Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard diethylene glycol dimethyl ether peak is set to 1.0, this is the area of ​​the 1,3-butylene glycol peak that appears in the range of relative retention time from 0.72 to 0.88 in the Scan mode m / z72 ion chromatogram. [Conditions for gas chromatography analysis] Analytical sample: An analytical sample prepared by mixing 1,3-butylene glycol product with an aqueous solution containing citric acid, trisodium citrate, sodium EDTA, and phenoxyethanol, so that the concentration of 1,3-butylene glycol product was 20% by mass, citric acid was 0.01% by mass, trisodium citrate was 0.04% by mass, sodium EDTA was 0.25% by mass, and phenoxyethanol was 0.7% by mass, and then allowing the mixture to stand at 50°C for 4 weeks. Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction method: Split sample introduction method Sample introduction temperature: 250℃ Initial pressure at the inlet: 15.3 psi Control mode: Constant flow (Average linear velocity: 24.7 cm / sec) Split ratio: 20 Carrier gas: Helium Gas flow rate of column: 1 mL / min, Helium Total flow rate: 24 mL / min · Conditions for mass spectrometry (MS) Ionization method: EI method Ionization voltage and current: 70 eV, 35 μA Ion source temperature: 230 °C Quadrupole temperature: 150 °C Interface temperature: 250 °C Measurement mode: SIM / Scan simultaneous measurement Scan mass range: m / z 29 - 550 SIM monitor ions: m / z 101, m / z 55 Cycle time: 3.8 cycles / second

[0012] The above 1,3 - butylene glycol product preferably contains a compound having a peak in the SIM mode m / z 101 ion chromatogram and a peak in the SIM mode m / z 55 ion chromatogram in the gas chromatography analysis under the above conditions, as a component corresponding to peak X appearing in the relative retention time range of 0.59 - 0.65.

[0013] The above 1,3 - butylene glycol product, as a component corresponding to peak X appearing in the relative retention time range of 0.59 - 0.65, has the following formula (1) [Chemical formula] and preferably contains the compound (2,4 - dimethyl - 1,3 - dioxane).

[0014] The 1,3 - butylene glycol in the above 1,3 - butylene glycol product is preferably a reduced form of at least one compound selected from the group consisting of acetaldol, paraldehyde, and aldoxane.

[0015] In addition, the present disclosure also provides a moisturizing agent containing the above 1,3 - butylene glycol product.

[0016] Furthermore, this disclosure also provides cosmetic compositions containing the above-mentioned 1,3-butylene glycol product. [Effects of the Invention]

[0017] The 1,3-butylene glycol product disclosed herein is less likely to produce an apple odor or pungent odor when incorporated into cosmetic compositions, and is therefore suitable for use in cosmetics, moisturizers, and other applications. [Brief explanation of the drawing]

[0018] [Figure 1] This is a flowchart of the manufacturing method for the 1,3-butylene glycol product of this disclosure. [Figure 2] This is the overall TIC chromatogram chart in Scan mode of GC / MS measurement for analytical samples prepared using the 1,3-butylene glycol product of Example 1. [Figure 3] (a) This is a TIC chromatogram chart in Scan mode (retention time 0-15 minutes) of an analytical sample prepared using the 1,3-butylene glycol product of Example 1. (b) This is a m / z 55 ion chromatogram chart in SIM mode (retention time 0-15 minutes) of the above analytical sample. (c) This is a m / z 101 ion chromatogram chart in SIM mode (retention time 0-15 minutes) of the above analytical sample. [Figure 4] This is a diagram showing Figures 3(a) to (c) arranged in a row. [Figure 5] This is the overall TIC chromatogram chart (Scan mode) of the analytical sample prepared using the 1,3-butylene glycol product of Comparative Example 2, measured by GC / MS. [Figure 6](a) This is the TIC chromatogram chart in Scan mode (retention time 0-15 minutes) of the analytical sample prepared using the 1,3-butylene glycol product of Comparative Example 2. (b) This is the m / z 55 ion chromatogram chart in SIM mode (retention time 0-15 minutes) of the above analytical sample. (c) This is the m / z 101 ion chromatogram chart in SIM mode (retention time 0-15 minutes) of the above analytical sample. [Figure 7] This is a diagram showing Figures 6(a) to (c) arranged in a row. [Modes for carrying out the invention]

[0019] The 1,3-butylene glycol products of this disclosure are described below, but the configurations and combinations thereof in each embodiment are examples only, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments.

[0020] The 1,3-butylene glycol product of this disclosure has an area ratio of 10 to 280 as shown by the following formula. Area ratio = Peak x Area / 1,3BG Peak Area × 10 6 Peak X Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​Peak X appearing in the SIM mode m / z101 ion chromatogram within the range of relative retention time of 0.59 to 0.65 is defined as the area of ​​Peak X. 1,3BG Peak Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard diethylene glycol dimethyl ether peak is set to 1.0, this is the area of ​​the 1,3-butylene glycol peak that appears in the range of relative retention time from 0.72 to 0.88 in the Scan mode m / z72 ion chromatogram.

[0021] [Conditions for gas chromatography analysis] Analytical sample: An analytical sample prepared by mixing 1,3-butylene glycol product with an aqueous solution containing citric acid, trisodium citrate, sodium EDTA, and phenoxyethanol, so that the concentration of 1,3-butylene glycol product was 20% by mass, citric acid was 0.01% by mass, trisodium citrate was 0.04% by mass, sodium EDTA was 0.25% by mass, and phenoxyethanol was 0.7% by mass, and then allowing the mixture to stand at 50°C for 4 weeks. Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction method: Split sample introduction method Sample introduction temperature: 250℃ Initial pressure at the inlet: 15.3 psi Control mode: Constant flow (Average linear velocity: 24.7 cm / sec) Split ratio: 20 Carrier gas: Helium Column gas flow rate: 1 mL / min, helium Total flow: 24mL / min • Conditions for mass spectrometry (MS) Ionization method: EI method Ionization voltage and current: 70 eV, 35 μA Ion source temperature: 230℃ Quadrupole temperature: 150℃ Interface temperature: 250℃ Measurement mode: Simultaneous SIM / Scan measurement Scan mass range: m / z 29~550 SIM monitor ion: m / z101, m / z55 Cycle time: 3.8 cycles / second

[0022] In the gas chromatography analysis under the above conditions, the reason for using a mixture of 1,3-butylene glycol product and an aqueous solution containing citric acid, etc., as the analytical sample is that cosmetic compositions generally contain citric acid, etc., and therefore the analytical sample can be considered a type of cosmetic composition containing 1,3-butylene glycol product. However, the cosmetic composition described in this specification is not limited to the analytical sample itself.

[0023] The above area ratio is not particularly limited as long as it is between 10 and 280, but for example, it could be 270 or less, 260 or less, 250 or less, 240 or less, 230 or less, 220 or less, 210 or less, 200 or less, 185 or less, 170 or less, 155 or less, 145 or less, 135 or less, 125 or less, 110 or less, 100 or less, 90 or less, 80 or less, or 70 or less. Alternatively, the above area ratio could be 20 or more, 30 or more, 40 or more, or 45 or more. The above area ratio corresponds to the amount of substance corresponding to peak X in the analytical sample prepared using the 1,3-butylene glycol product of this disclosure. In other words, the magnitude of the above area ratio corresponds to the amount of substance corresponding to peak X contained in the analytical sample. The substance corresponding to peak X is not originally contained in the 1,3-butylene glycol product, but is expected to be formed from substances contained in the 1,3-butylene glycol product during the process of preparing the analytical sample. In other words, during the preparation of the analytical sample described above, it is expected that the substances contained in the 1,3-butylene glycol product will change structure due to the influence of citric acid, etc., and some or all of them will become the substance corresponding to peak X. Therefore, a large area ratio can be said to correlate with a large content of the substance contained in the 1,3-butylene glycol product. Conversely, a small area ratio can be said to correlate with a small content of the substance contained in the 1,3-butylene glycol product. Specifically, "substances contained in the 1,3-butylene glycol product" refers to substances other than 1,3-butylene glycol contained in the 1,3-butylene glycol product. When the area ratio is within the above range, the generation of apple odor and pungent odor tends to be further suppressed when the 1,3-butylene glycol product is incorporated into cosmetic compositions.

[0024] In gas chromatography analysis under the above conditions, the component corresponding to peak X is a compound that has a peak in the SIM mode m / z 101 ion chromatogram and also has a peak in the SIM mode m / z 55 ion chromatogram.

[0025] In gas chromatography analysis under the above conditions, an example of the component corresponding to peak X is the compound of formula (1) below (2,4-dimethyl-1,3-dioxane, DMDO).

[0026] [ka]

[0027] In the gas chromatography analysis under the above conditions, the DMDO content in the analytical sample is not particularly limited, but is preferably 12.5 ppm or less, more preferably 12 ppm or less, even more preferably 11 ppm or less, even more preferably 10 ppm or less, even more preferably 9 ppm or less, even more preferably 8 ppm or less, even more preferably 7 ppm or less, even more preferably 6 ppm or less, and even more preferably 5 ppm or less. Also, is preferably greater than 0 ppm, more preferably 0.1 ppm or more, even more preferably 0.5 ppm or more, even more preferably 1 ppm or more, even more preferably 2 ppm or more, and particularly preferably 2.5 ppm or more. In other words, the DMDO content in the analytical sample is, for example, 0.1 ppm or more and 12.5 ppm or less. These DMDO contents were calculated using a calibration curve prepared by mixing 1 g of a sample prepared by diluting DMDO with a 20% aqueous solution of 1,3-butylene glycol to an appropriate concentration with 0.01 g of an internal standard (diethylene glycol dimethyl ether).

[0028] The compound of formula (1) above may or may not be an odorous substance generated when a 1,3-butylene glycol product is incorporated into a cosmetic composition. Here, "odorous substance" refers to a substance in which the compound itself emits an odor (for example, an apple odor).

[0029] In the 1,3-butylene glycol product of this disclosure (i.e., the 1,3-butylene glycol product itself, not the analytical sample), the area ratio of the 1,3-butylene glycol peak in gas chromatography analysis under the following conditions is preferably 99.5% or more, more preferably 99.7% or more, even more preferably 99.8% or more, and particularly preferably 99.9% or more. The above-mentioned "area ratio of the 1,3-butylene glycol peak" means the ratio of the area of ​​a particular peak to the sum of the areas of all peaks appearing in the chart. Furthermore, "all peaks" means, for example, all peaks that appear when the analysis is continued and stopped when the relative retention time of the 1,3-butylene glycol peak is set to 1.0, but peaks originating from the internal standard are not included. Furthermore, when the relative retention time of the diethylene glycol dimethyl ether peak, which is the internal standard, is set to 1.0, the above-mentioned 1,3-butylene glycol peak appears in the relative retention time range of 0.69 to 0.92.

[0030] (Conditions for gas chromatography analysis) Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction temperature: 250℃ Carrier gas: Helium Column gas flow rate: 1 mL / min Detector and detection temperature: Flame ionization detector (FID), 280°C

[0031] Examples of 1,3-butylene glycol in the 1,3-butylene glycol products of this disclosure include (1) reduced acetaldols, (2) hydrolysates of 1,3-butylene oxide, (3) selective hydrolysis products of erythritol, (4) selective hydrate adducts to butadiene, (5) hydride of n-butanal-3-one, (6) hydride of 1-butanol-3-one, (7) hydride of 3-hydroxy-1-butanoic acid, (8) hydride of β-butyrolactone, and (9) hydride of diketene. The 1,3-butylene glycol in this disclosure may be one or a mixture of two or more of the above (1) to (9).

[0032] In the 1,3-butylene glycol products of this disclosure, 1,3-butylene glycol is preferably (1) a reduced form of acetaldols. Furthermore, from the viewpoint of yielding 1,3-butylene glycol, the liquid-phase reduced form of acetaldols is preferable as the reduced form of acetaldols. The reasons for this are that acetaldols have high boiling points, are thermally unstable and readily undergo dehydration reactions at high temperatures to form crotonaldehyde, etc., and furthermore, the reaction rate of reduction (hydrogenation) is faster than that of dehydration at high temperatures. In other words, when reducing acetaldols in the gas phase, it is necessary to raise the temperature of the reaction system, but when acetaldols are subjected to high temperatures, they undergo a dehydration reaction to produce crotonaldehyde, etc., and subsequent reduction reactions produce byproducts such as butanol. As a result, the yield of the target 1,3-butylene glycol is relatively reduced. Therefore, in order to obtain a high-purity 1,3-butylene glycol product, liquid-phase reduction is preferable to gas-phase reduction. Here, 1,3-butylene glycol as a reduced form of acetaldehyde can be rephrased as 1,3-butylene glycol obtained by hydrogen reduction of acetaldehyde. Similarly, 1,3-butylene glycol as a liquid-phase reduced form of acetaldehyde can be rephrased as 1,3-butylene glycol obtained by hydrogen reduction of acetaldehyde in the liquid phase. Furthermore, 1,3-butylene glycol as a hydrolysate of 1,3-butylene oxide can be rephrased as 1,3-butylene glycol obtained by hydrolysis of 1,3-butylene oxide.

[0033] Generally, when 1,3-butylene glycol is produced, by-products are generated during the manufacturing process. For example, when 1,3-butylene glycol is produced by hydrogenation of acetaldehyde, by-products include low-boiling-point substances (low-boiling-point compounds) with unsaturated bonds such as acetaldehyde, butyraldehyde, crotonaldehyde, acetone, and methyl vinyl ketone, as well as condensates of these substances, and condensates of 1,3-butylene glycol with the above low-boiling-point substances (for example, acetal compounds of 1,3-butylene glycol and acetaldehyde). In addition, by-products include acetal compounds of crotonaldehyde and 1,3-butylene glycol, acetal compounds of acetaldehyde and 1,3-butylene glycol, and acetal compounds of acetaldehyde or acetaldehyde with hydrides of acetaldehyde trimers.

[0034] Furthermore, these by-products may possess the properties of odor-causing substances. Here, odor-causing substances are defined to include not only substances that currently emit an odor themselves, but also substances that change over time to emit an odor (for example, an apple odor).

[0035] Hydrogenated raw materials containing acetaldehyde compounds are used in the production of 1,3-butylene glycol. The acetaldehyde compounds are not particularly limited as long as they are compounds that can be converted to 1,3-butylene glycol by hydrogen reduction, but examples include acetaldehyde, its cyclized dimer para-aldol, aldoxanes which are a type of cyclic trimer of acetaldehyde, and mixtures thereof.

[0036] The method for producing acetaldols (e.g., acetaldol and para-aldol) is not particularly limited, but may be obtained, for example, by the aldol condensation reaction of acetaldehyde in the presence of a basic catalyst, or by the thermal decomposition of aldoxanes. The crude reaction solution containing the acetaldols obtained by the above reaction may be neutralized with an acid and used for the production of 1,3-butylene glycol. Such a crude reaction solution may contain, in addition to acetaldols, low-boiling-point substances such as acetaldehyde and crotonaldehyde, high-boiling-point substances such as aldehyde dimers and aldehyde trimers, water, salts, etc. In this specification, compounds with a boiling point lower than 1,3-butylene glycol may be referred to as "low-boiling-point substances," and compounds with a boiling point higher than 1,3-butylene glycol may be referred to as "high-boiling-point substances."

[0037] The crude reaction solution described above may be pretreated as needed, such as by dealcoholization distillation, dehydration distillation, desalting, and impurity removal, to remove unreacted acetaldehyde and by-products such as crotonaldehyde. Pretreatment methods include distillation, adsorption, ion exchange, heating to create high-boiling point substances, and decomposition. Various distillation methods can be used, including reduced pressure, atmospheric pressure, pressurized distillation, azeotropic distillation, extraction, and reaction.

[0038] The hydrogenation raw material may or may not contain water, but it is preferable that it contains water. That is, in the 1,3-butylene glycol product of this disclosure, it is preferable that the 1,3-butylene glycol is obtained by hydrogen reduction of a hydrogenation raw material containing water and acetaldols. The above 1,3-butylene glycol can be rephrased as the hydrogen reduction product of a hydrogenation raw material containing water and acetaldols.

[0039] The content of acetaldols in the hydrogenated raw material is not particularly limited, but is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. When the content of acetaldols is within the above range, the amount of by-products contained in crude 1,3-butylene glycol tends to be reduced.

[0040] The water content in the hydrogenated raw material is not particularly limited, but for example, 10% by mass or more is preferred, 25% by mass or more is more preferred, 40% by mass or more is even more preferred, more than 50% by mass is even more preferred, and 55% by mass or more is particularly preferred. Also, for example, 80% by mass or less is preferred, more preferably 70% by mass or less, and even more preferably 60% by mass or less. When the water content is within the above range, the generation of odor (apple odor and pungent odor) when the 1,3-butylene glycol product is incorporated into a cosmetic composition tends to be reduced. When the water content in the hydrogenated raw material exceeds 50% by mass, the above tendency becomes stronger, and the generation of odor (especially apple odor) is greatly reduced. Generally speaking, the production efficiency of 1,3-butylene glycol decreases as the water content in the hydrogenated raw material increases. Therefore, it is common practice to set the water content so that it does not become too high (for example, at least 50% by mass or less). For this reason, there has been no conventional idea of ​​increasing the water content in the hydrogenated raw material. In the invention disclosed here, by increasing the water content to a certain extent, appropriately adjusting the purification method of crude 1,3-butylene glycol, and by a combination of these, the previously unknown problem of less odor (apple odor and pungent odor) being generated when incorporated into cosmetic compositions has been solved.

[0041] The following describes a method for producing crude 1,3-butylene glycol. This method involves reducing a hydrogenation raw material containing acetaldols in the presence of a hydrogenation catalyst to obtain crude 1,3-butylene glycol.

[0042] Examples of hydrogenation catalysts include Raney nickel. The hydrogenation catalyst can be used in suspension or packed form, but it is preferable to use it in suspension form. The amount of hydrogenation catalyst used is not particularly limited, but is preferably, for example, 1 to 30 parts by mass, more preferably 4 to 25 parts by mass, even more preferably 8 to 20 parts by mass, and particularly preferably 12 to 18 parts by mass, per 100 parts by mass of hydrogenation raw material. The amount of hydrogen used in the reduction reaction is not particularly limited, but is preferably, for example, 0.5 to 40 parts by mass, more preferably 1 to 30 parts by mass, even more preferably 4 to 20 parts by mass, and particularly preferably 8 to 12 parts by mass, per 100 parts by mass of hydrogenation raw material. The pressure (total pressure) in the reaction system during the reduction reaction is not particularly limited, but is preferably, for example, 150 to 500 atm, more preferably 180 to 450 atm, even more preferably 200 to 400 atm, and particularly preferably 250 to 350 atm. The ratio of hydrogen pressure (partial pressure of hydrogen) to total pressure in the reaction system is not particularly limited, but is preferably 80% or more (80-100%) of the total pressure, more preferably 85-99.9%, even more preferably 90-99.5%, and most preferably 95-99%. The hydrogen pressure (partial pressure of hydrogen) in the reaction system is not particularly limited, but is preferably 100-500 atm, more preferably 150-450 atm, even more preferably 150-400 atm, and most preferably 200-350 atm. The reaction temperature in the reduction reaction is not particularly limited, but is preferably 110-140°C, more preferably 120-140°C. The reaction time (residence time) in the reduction reaction is not particularly limited, but is preferably 30-300 minutes, more preferably 80-280 minutes, and even more preferably 120-250 minutes.

[0043] The reaction rate (hydrogenation rate) from acetaldehyde to 1,3-butylene glycol is improved when the amount of hydrogenation catalyst used in the reduction reaction, the amount of hydrogen, the hydrogen pressure in the reduction reaction, the reaction temperature, and the reaction time (residence time) are within the above range. For example, the acetalization reaction between 1,3-butylene glycol and acetaldehyde is reduced, and a high-purity 1,3-butylene glycol product tends to be obtained. This tendency is particularly strongly influenced by the hydrogen pressure in the reduction reaction. That is, when the hydrogen pressure in the reduction reaction is within the above range, the reaction rate (reduction rate) from acetaldehyde to 1,3-butylene glycol is significantly improved, and as a result, the acetal product of 1,3-butylene glycol and acetaldehyde is reduced, and a high-purity 1,3-butylene glycol product is obtained. This reaction can be carried out in batch, semi-batch, or continuous configurations.

[0044] Crude 1,3-butylene glycol obtained by hydrogenation reduction of the above-mentioned hydrogenated raw material can be processed into a 1,3-butylene glycol product by, for example, a dehydration step, desalting step, de-high-boiling point distillation step, alkali reaction step, de-alkalization step, and distillation step. In particular, the conditions for hydrogenation reduction of the hydrogenated raw material, the de-high-boiling point distillation step, and the de-alkalization step tend to reduce the generation of odors (apple odor and pungent odor) when the 1,3-butylene glycol product is incorporated into a cosmetic composition.

[0045] The content of high-boiling-point substances in the crude 1,3-butylene glycol described above is not particularly limited, but is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. Alternatively, it may be 0.1% by mass or more, 1% by mass or more, or 2% by mass or more. When the content of high-boiling-point substances in the crude 1,3-butylene glycol is within the above range, the amount of by-products (especially odor-causing substances) contained in the final 1,3-butylene glycol product tends to be reduced.

[0046] The content of high-boiling-point substances in the crude 1,3-butylene glycol after the high-boiling-point distillation process is 0.5% by mass or less, preferably 0.3% by mass or less, and more preferably 0.1% by mass or less. By using crude 1,3-butylene glycol with a low content of high-boiling-point substances, even when heated with a base in the alkaline reaction process, the formation of low-boiling-point substances due to the decomposition reaction of high-boiling-point substances is absent or extremely reduced. As a result, there is a tendency to obtain a very high-quality 1,3-butylene glycol product with fewer odor-causing substances.

[0047] Figure 1 is a flow sheet of an apparatus illustrating an example of an embodiment for obtaining the 1,3-butylene glycol product of this disclosure. A is a dehydration tower and is related to the dehydration process. B is a desalination tower and is related to the desalination process. C is a high-boiling-point distillation tower and is related to the high-boiling-point distillation process. D is an alkali reactor and is related to the alkali reaction process. E is an alkali dealkaliation tower and is related to the alkali dealkaliation process. F is a product distillation tower and is related to the distillation process. A-1, B-1, C-1, E-1, and F-1 are condensers. A-2, C-2, and F-2 are reboilers. The following describes an example of an embodiment for obtaining the 1,3-butylene glycol product of this disclosure using this flow sheet.

[0048] Crude 1,3-butylene glycol (corresponding to "X-1") obtained by hydrogenation reduction of the hydrogenated raw material is supplied to dehydration column A. In dehydration column A, water is distilled off from the top of the column, and a crude 1,3-butylene glycol stream containing 1,3-butylene glycol is obtained from the bottom of the column. The crude 1,3-butylene glycol stream is supplied to desalination column B. In desalination column B, a desalted crude 1,3-butylene glycol stream is obtained from the top of the column by distillation, and salts and high-boiling point substances are discharged from the bottom of the column.

[0049] The crude 1,3-butylene glycol stream after desalting is supplied to the de-high-boiling-point distillation column C. In the de-high-boiling-point distillation column C, high-boiling-point substances (and 1,3-butylene glycol containing them) are discharged from the bottom of the column. On the other hand, a crude 1,3-butylene glycol stream after de-high-boiling-point substances is obtained from the top of the column. The amount of 1,3-butylene glycol containing high-boiling-point substances discharged from the bottom of the column is preferably 10 to 50 parts, more preferably 20 to 45 parts, even more preferably 23 to 40 parts, even more preferably 25 to 35 parts, and particularly preferably 25 to 30 parts per 100 parts of the feed liquid. On the other hand, the amount of crude 1,3-butylene glycol obtained from the top of the column is preferably 50 to 90 parts, more preferably 55 to 85 parts, even more preferably 60 to 80 parts, and particularly preferably 65 to 75 parts per 100 parts of the feed liquid. Because the amount of 1,3-butylene glycol containing high-boiling-point substances discharged from the bottom of the column and the amount of crude 1,3-butylene glycol obtained from the top of the column are within the above range, the generation of apple odor and pungent odor when the final 1,3-butylene glycol product is incorporated into cosmetic compositions tends to be further reduced. Although the reason for this is not clear, it is thought that the substances originating from the above odor are largely contained as high-boiling-point substances in the crude 1,3-butylene glycol and are discharged in large quantities from the bottom of the column during this process (high-boiling-point distillation process).

[0050] Crude 1,3-butylene glycol distilled in the high-boiling point decontamination distillation column C is supplied to an alkaline reactor (e.g., a flow-through tubular reactor) D and subjected to base treatment. In alkaline reactor D or upstream thereof, a base is added at a rate of 0.05 to 10% by mass, preferably 0.1 to 1.0% by mass, relative to the crude 1,3-butylene glycol stream after high-boiling point decontamination. If the amount of base added exceeds 10% by mass, the base tends to precipitate in the distillation column, piping, etc., causing blockage. In addition, decomposition reactions of high-boiling point compounds may occur, which tends to generate byproducts. If the amount is less than 0.05% by mass, the effect of decomposing byproducts is small, so neither is desirable.

[0051] The base added in or upstream of the alkaline reactor D is not particularly limited, but alkali metal compounds are preferred, for example. Examples of alkali metal compounds include caustic soda, caustic potash, (bi)sodium carbonate, and (bi)potassium carbonate, but caustic soda and caustic potash are preferred from the viewpoint of reducing by-products contained in the final 1,3-butylene glycol product. The base may be added in solid form, but it is preferable to add it as an aqueous solution for operational reasons and to promote contact with the target liquid. One of the above bases may be used alone, or two or more may be used simultaneously.

[0052] The reaction temperature in alkaline reactor D is not particularly limited, but is preferably 90-140°C, and more preferably 110-130°C. If the reaction temperature is below 90°C, a long reaction residence time is required, which tends to increase the reactor capacity and become uneconomical. If the reaction temperature exceeds 140°C, the coloration of the final 1,3-butylene glycol product tends to increase. The reaction residence time is preferably 5-120 minutes, and more preferably 10-30 minutes. If the reaction residence time is less than 5 minutes, the reaction is insufficient, and the quality of the final 1,3-butylene glycol product deteriorates. If the reaction residence time exceeds 120 minutes, a large reactor is required, which increases equipment costs and is therefore uneconomical.

[0053] After exiting the alkali reactor D, the crude reaction flow is supplied to the dealkaliation column (thin film evaporator) E, where bases, high-boiling point substances (and 1,3-butylene glycol containing these) are removed from the bottom of the column by evaporation. Meanwhile, a crude 1,3-butylene glycol flow after debasement is obtained from the top of the dealkaliation column E. To suppress the thermal history of the process fluid, a gravity-flow thin film evaporator or a forced-stirred thin film evaporator with a short residence time is suitable for use in the dealkaliation column E. The amount of 1,3-butylene glycol containing bases etc. discharged from the bottom of the column is preferably 5 to 40 parts, more preferably 10 to 30 parts, even more preferably 13 to 25 parts, and particularly preferably 15 to 20 parts per 100 parts of the charge. On the other hand, the amount of crude 1,3-butylene glycol obtained from the top of the column is preferably 60 to 95 parts, more preferably 70 to 90 parts, even more preferably 75 to 87 parts, and particularly preferably 80 to 85 parts per 100 parts of the feed liquid. When the amount of 1,3-butylene glycol discharged from the bottom of the column, including high-boiling-point substances, and the amount of crude 1,3-butylene glycol obtained from the top of the column are within the above ranges, the generation of apple odor and pungent odor when the final 1,3-butylene glycol product is incorporated into a cosmetic composition tends to be further reduced. Although the reason for this is not clear, it is thought that the substances originating from the above odor are largely contained as high-boiling-point substances in the crude 1,3-butylene glycol and are discharged in large quantities from the bottom of the column during this process (dealkalization process).

[0054] When the amount charged to distillation column C is set to 100, the total amount of discharged material from distillation column C and dealkalization column E (external discharge) is not particularly limited, but is preferably 20 to 60, more preferably 24 to 55, even more preferably 28 to 50, and most preferably 32 to 45.

[0055] In the evaporator used in the dealkaliation column E, for example, evaporation is carried out under reduced pressure of 100 torr or less, preferably 5 to 20 torr, at the top of the column. The temperature of the evaporator is preferably 90 to 120°C. A crude 1,3-butylene glycol stream containing low-boiling point substances distilled from the top of the column is supplied to the product distillation column F.

[0056] Product distillation column F can be, for example, a perforated plate column or a bubble bell column, but a packed column with low pressure loss, such as one filled with Sluzer Packing or Melapack (both product names of Sumitomo Heavy Industries, Ltd.), is more preferable. This is because 1,3-butylene glycol decomposes at high temperatures (e.g., 150°C or higher), producing low-boiling-point substances that are coloring components, so the distillation temperature must be kept low. Similarly, a long thermal history (residence time) applied to 1,3-butylene glycol also has an effect. Therefore, the reboiler used should be one with a short residence time for the process fluid, such as a thin-film evaporator, a gravity-fed thin-film evaporator, or a forced-agitated thin-film evaporator.

[0057] When the concentration of low-boiling-point substances in the feed liquid is 5% by mass or less, the theoretical number of stages in the product distillation column F is preferably 10 to 20. The feed liquid is preferably supplied from the top of the column to a position 20 to 70% of the column's height. In distillation in the product distillation column F, the pressure at the top of the column is preferably, for example, 100 torr or less, and more preferably 5 to 20 torr. The reflux ratio is preferably, for example, 0.5 to 2.0.

[0058] In Figure 1, the product distillation column F is fed with a liquid obtained by condensing the top vapor from the dealkalization column E in condenser E-1, but the top vapor from the dealkalization column E may also be fed directly to the product distillation column F. In the product distillation column F, impurities such as low-boiling point substances are distilled off from the top, and 1,3-butylene glycol as the product is obtained from the bottom of the product distillation column F (corresponding to "Y").

[0059] [Moisturizers and cosmetics] The humectant of this disclosure contains the above-mentioned 1,3-butylene glycol product. Therefore, it has excellent moisturizing performance, is free from discoloration and odor, is less prone to discoloration over time, and is less prone to an increase in acid concentration over time even when it contains water. The humectant of this disclosure may also contain components other than the above-mentioned 1,3-butylene glycol product, for example, other humectant components other than the above-mentioned 1,3-butylene glycol product. In the humectant of this disclosure, the content of the above-mentioned 1,3-butylene glycol product is, for example, 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, and may consist only of the above-mentioned 1,3-butylene glycol product.

[0060] The cosmetic composition of this disclosure contains the above-mentioned humectant. The amount of the 1,3-butylene glycol product in the cosmetic composition of this disclosure may be any amount that provides sufficient moisturizing performance, depending on the type and form of the cosmetic. The amount of the 1,3-butylene glycol product in the cosmetic composition of this disclosure is, for example, 0.01 to 40% by mass, preferably 0.1 to 30% by mass, more preferably 0.2 to 20% by mass, even more preferably 0.5 to 15% by mass, and particularly preferably 1 to 10% by mass.

[0061] In addition to the 1,3-butylene glycol product described above, the cosmetics disclosed herein may also contain, for example, other moisturizers; oils such as vegetable oils, hydrocarbon oils, higher fatty acids, higher alcohols, and silicones; surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; preservatives, metal ion chelating agents, thickeners, powders, UV absorbers, UV blockers, fragrances, and pH adjusters; and medicinal and physiologically active ingredients such as vitamins, skin activators, blood circulation promoters, whitening agents, antibacterial agents, and anti-inflammatory agents.

[0062] The cosmetics disclosed herein may include skin cosmetics such as lotions, emulsions, creams, gels, packs, and masks, as well as hair cosmetics such as shampoos, conditioners, and hair growth products. They may also be sunscreens or makeup cosmetics. Furthermore, they may be pharmaceuticals or quasi-drugs containing medical ingredients.

[0063] The cosmetic composition of this disclosure can be manufactured by a well-known method.

[0064] Each embodiment disclosed herein can be combined with any other features disclosed herein. Each configuration and combination thereof in each embodiment is an example, and additions, omissions, substitutions, and other modifications are permitted as appropriate, without departing from the spirit of this disclosure. Furthermore, the inventions relating to this disclosure are not limited by the embodiments or the following examples. [Examples]

[0065] The present disclosure will be further described below with reference to examples. In the examples, the term "part" refers to "parts by mass" unless otherwise specified.

[0066] [Example 1] The method for producing 1,3-butylene glycol will be explained using Figure 1. To 100 parts of an acetaldol solution containing 55% by mass of water (a mixed solution of 45 parts acetaldol and 55 parts water), 10 parts of hydrogen were charged into a liquid-phase hydrogen reduction reactor. 15 parts of Raney nickel were added as a catalyst, and the reactor was maintained at 135°C and 300 atm for liquid-phase hydrogen reduction. After the reaction, the catalyst was separated from the liquid, which was then neutralized with caustic soda to remove alcohols and obtain crude 1,3-butylene glycol (1).

[0067] Crude 1,3-butylene glycol (1) (corresponding to "X-1" in Figure 1) was charged into dehydration tower A. In dehydration tower A, water was removed from the top of the tower for every 100 parts of the charged liquid, 15 parts of fresh water were added as reflux water, and the pressure was set to 50 torr. Crude 1,3-butylene glycol (2) with a water content of 0.5% by mass or less was obtained from the bottom of the tower. The water removed from the top of the tower was discharged (corresponding to "X-2" in Figure 1).

[0068] Next, crude 1,3-butylene glycol (2) was charged into demineralization column B. In demineralization column B, salt, high-boiling point substances, and a portion of 1,3-butylene glycol were discharged from the bottom of the column as evaporation residue (corresponding to "X-3" in Figure 1). The amount of evaporation residue discharged was 5 parts per 100 parts of the charged liquid. On the other hand, crude 1,3-butylene glycol (3), containing 1,3-butylene glycol, low-boiling point substances, and a portion of high-boiling point substances, was obtained from the top of the column.

[0069] Next, crude 1,3-butylene glycol (3) was charged into the high-boiling point distillation column C. In the high-boiling point distillation column C, high-boiling point substances and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to "X-4" in Figure 1). The discharge amount was 20 parts per 100 parts of the charged liquid. On the other hand, 80 parts of crude 1,3-butylene glycol (4) containing low-boiling point substances were obtained from the top of the column. Next, crude 1,3-butylene glycol (4) was charged into the alkaline reactor D. At this time, a 10% by mass aqueous solution of caustic soda was added so that the concentration of caustic soda relative to the charged liquid was 0.2% by mass. The reaction temperature in the alkaline reactor D was maintained at 120°C and the reaction was carried out with a residence time of 20 minutes.

[0070] Next, the crude reaction solution from alkaline reactor D was charged into dealkalization column E. In dealkalization column E, caustic soda, high-boiling point substances, and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to "X-5" in Figure 1). The discharge amount was 10 parts per 100 parts of the charged liquid. On the other hand, 90 parts of crude 1,3-butylene glycol (5), including 1,3-butylene glycol and low-boiling point substances, were obtained from the top of the column.

[0071] When the amount of charge into distillation column C was set to 100, the total amount of discharged material from distillation column C and dealkalization column E (external discharge) was 28.

[0072] Next, crude 1,3-butylene glycol (5) was charged into product distillation column F. In product distillation column F, for every 100 parts of the charged liquid, 10 parts of the low-boiling point substance and a portion of the 1,3-butylene glycol were distilled from the top of the column (corresponding to "X-6" in Figure 1), and 90 parts of the 1,3-butylene glycol product were obtained from the bottom of the column (corresponding to "Y" in Figure 1).

[0073] The obtained 1,3-butylene glycol product was subjected to GC / MS analysis under the conditions described below. The area ratio shown in the formula below for the analytical sample prepared using the 1,3-butylene glycol product was 190. The score for Odor Test 1 was 2, and the score for Odor Test 2 was 1.

[0074] [Example 2] In distillation column C, the discharge amount was 25 parts per 100 parts of the charge, and 75 parts of crude 1,3-butylene glycol (4) containing low-boiling substances obtained from the top of the column were collected. Furthermore, in dealkalization column E, the discharge amount was 17 parts per 100 parts of the charge, and 83 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances obtained from the top of the column were collected. The 1,3-butylene glycol product was obtained in the same manner as in Example 1, except that the discharge amount per 100 parts of the charge was 17 parts, and 83 parts of crude 1,3-butylene glycol (5) containing low-boiling substances obtained from the top of the column were collected. The total discharge amount (external discharge amount) from distillation column C and dealkalization column E, when the charge amount to distillation column C is set to 100, was 37.75.

[0075] The obtained 1,3-butylene glycol product was subjected to GC / MS analysis under the conditions described below. The area ratio shown in the formula below for the analytical sample prepared using the 1,3-butylene glycol product was 140. The score for Odor Test 1 was 1, and the score for Odor Test 2 was 1.

[0076] [Example 3] In obtaining crude 1,3-butylene glycol (1), 100 parts of an acetaldol solution containing 60% by mass of water (a mixed solution of 40 parts acetaldol and 60 parts water) was used as a raw material. In distillation column C, the discharge amount was 25 parts per 100 parts of the charge, and 75 parts of crude 1,3-butylene glycol (4) containing low-boiling substances were obtained from the top of the column. Furthermore, in dealkalization column E, the discharge amount was 17 parts per 100 parts of the charge, and 83 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. The 1,3-butylene glycol product was obtained in the same manner as in Example 1, except that the discharge amount was 17 parts per 100 parts of the charge, and 83 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. The total discharge amount (external discharge amount) in distillation column C and dealkalization column E, when the amount charged to distillation column C is set to 100, was 37.75.

[0077] The obtained 1,3-butylene glycol product was subjected to GC / MS analysis under the conditions described below. The area ratio of the analytical sample prepared using the 1,3-butylene glycol product, as shown by the formula described below, was 91. The score for Odor Test 1 was 1, and the score for Odor Test 2 was 1.

[0078] [Example 4] In obtaining crude 1,3-butylene glycol (1), 100 parts of an acetaldol solution containing 60% by mass of water (a mixed solution of 40 parts acetaldol and 60 parts water) was used as a raw material. In distillation column C, the discharge amount was 30 parts per 100 parts of the charge, and 70 parts of crude 1,3-butylene glycol (4) containing low-boiling substances were obtained from the top of the column. Furthermore, in dealkalization column E, the discharge amount was 20 parts per 100 parts of the charge, and 80 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. The 1,3-butylene glycol product was obtained in the same manner as in Example 1, except that the discharge amount was 20 parts per 100 parts of the charge, and 80 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. When the amount charged to distillation column C was set to 100, the total discharge amount (external discharge amount) in distillation column C and dealkalization column E was 44.

[0079] The obtained 1,3-butylene glycol product was subjected to GC / MS analysis under the conditions described below. The area ratio shown in the formula below for the analytical sample prepared using the 1,3-butylene glycol product was 50. The score for Odor Test 1 was 1, and the score for Odor Test 2 was 1.

[0080] [Comparative Example 1] In obtaining crude 1,3-butylene glycol (1), 100 parts of an acetaldol solution containing 65% by mass of water (a mixed solution of 35 parts acetaldol and 65 parts water) was used as a raw material. In distillation column C, the discharge amount was 32 parts per 100 parts of the charge, and 68 parts of crude 1,3-butylene glycol (4) containing low-boiling substances were obtained from the top of the column. Furthermore, in dealkalization column E, the discharge amount was 23 parts per 100 parts of the charge, and 77 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. The 1,3-butylene glycol product was obtained in the same manner as in Example 1, except that the discharge amount was 23 parts per 100 parts of the charge, and 77 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and low-boiling substances were obtained from the top of the column. When the amount charged to distillation column C was set to 100, the total discharge amount (external discharge amount) in distillation column C and dealkalization column E was 47.64.

[0081] GC / MS analysis of the obtained 1,3-butylene glycol product was performed under the conditions described below. The area ratio shown in the formula below for the analytical sample prepared using the 1,3-butylene glycol product was below the detection limit. The score for Odor Test 1 was 1, and the score for Odor Test 2 was 2.

[0082] [Comparative Example 2] To 100 parts of an acetaldol solution containing 30% by mass of water (a mixed solution of 30 parts acetaldol and 70 parts water), 10 parts of hydrogen were charged into a liquid-phase hydrogen reduction reactor. 15 parts of Raney nickel were added as a catalyst, and the reactor was maintained at 135°C and 300 atm for liquid-phase hydrogen reduction. After the reaction, the catalyst was separated from the liquid, which was then neutralized with caustic soda to remove alcohols and obtain crude 1,3-butylene glycol (1).

[0083] Crude 1,3-butylene glycol (1) (corresponding to "X-1" in Figure 1) was charged into dehydration tower A. In dehydration tower A, water was removed from the top of the tower for every 100 parts of the charged liquid, 15 parts of fresh water were added as reflux water, and the pressure was set to 50 torr. Crude 1,3-butylene glycol (2) with a water content of 0.5% by mass or less was obtained from the bottom of the tower. The water removed from the top of the tower was discharged (corresponding to "X-2" in Figure 1).

[0084] Next, crude 1,3-butylene glycol (2) was charged into demineralization column B. In demineralization column B, salt, high-boiling point substances, and a portion of 1,3-butylene glycol were discharged from the bottom of the column as evaporation residue (corresponding to "X-3" in Figure 1). The amount of evaporation residue discharged was 5 parts per 100 parts of the charged liquid. On the other hand, crude 1,3-butylene glycol (3), containing 1,3-butylene glycol, low-boiling point substances, and a portion of high-boiling point substances, was obtained from the top of the column.

[0085] Next, crude 1,3-butylene glycol (3) was charged into the high-boiling point distillation column C. In the high-boiling point distillation column C, high-boiling point substances and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to "X-4" in Figure 1). The discharge amount was 20 parts per 100 parts of the charged liquid. On the other hand, 80 parts of crude 1,3-butylene glycol (4) containing low-boiling point substances were obtained from the top of the column. Next, crude 1,3-butylene glycol (4) was charged into the alkaline reactor D. At this time, a 10% by mass aqueous solution of caustic soda was added so that the concentration of caustic soda relative to the charged liquid was 0.2% by mass. The reaction temperature in the alkaline reactor D was maintained at 120°C and the reaction was carried out with a residence time of 20 minutes.

[0086] Next, the crude reaction solution from alkaline reactor D was charged into dealkalization column E. In dealkalization column E, caustic soda, high-boiling point substances, and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to "X-5" in Figure 1). The discharge amount was 10 parts per 100 parts of the charged liquid. On the other hand, 90 parts of crude 1,3-butylene glycol (5), including 1,3-butylene glycol and low-boiling point substances, were obtained from the top of the column.

[0087] When the amount of charge into distillation column C was set to 100, the total amount of discharged material from distillation column C and dealkalization column E (external discharge) was 28.

[0088] Next, crude 1,3-butylene glycol (5) was charged into product distillation column F. In product distillation column F, for every 100 parts of the charged liquid, 10 parts of the low-boiling point substance and a portion of the 1,3-butylene glycol were distilled from the top of the column (corresponding to "X-6" in Figure 1), and 90 parts of the 1,3-butylene glycol product were obtained from the bottom of the column (corresponding to "Y" in Figure 1).

[0089] The obtained 1,3-butylene glycol product was subjected to GC / MS analysis under the conditions described below. The area ratio of the analytical sample prepared using the 1,3-butylene glycol product, as shown by the formula described below, was 285. The score for Odor Test 1 was 3, and the score for Odor Test 2 was 1.

[0090] [Comparative Example 3] Assume that when crude 1,3-butylene glycol (1) is obtained, the 1,3-butylene glycol product is obtained in the same manner as in Comparative Example 2, except that 100 parts of an acetaldol solution containing 20% ​​by mass of water (a mixed solution of 80 parts acetaldol and 20 parts water) is used as a raw material, and then GC / MS analysis is performed. The area ratio shown in the formula below for the analytical sample prepared using the 1,3-butylene glycol product exceeds 285. Furthermore, since the area ratio shown in the formula below exceeds 285, the score for Odor Test 1 is 3 and the score for Odor Test 2 is 1. This can be explained from the results of Example 1 and Comparative Example 2, where the area ratio shown in the formula below increases as the water content in the raw material decreases, and also from the fact that the odor (apple odor) becomes stronger as the area ratio shown in the formula below increases.

[0091] [Reference example 1] When the 1,3-butylene glycol product obtained in Example 1 was used directly (i.e., without any preparation of the analytical sample described later), the GC / MS analysis described later did not detect any peak X area.

[0092] [Method for calculating area ratio] Area ratio = Peak x Area / 1,3BG Peak Area × 10 6 Peak X Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​Peak X appearing in the SIM mode m / z101 ion chromatogram within the range of relative retention time of 0.59 to 0.65 is defined as the area of ​​Peak X. 1,3BG Peak Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard diethylene glycol dimethyl ether peak is set to 1.0, this is the area of ​​the 1,3-butylene glycol peak that appears in the range of relative retention time from 0.72 to 0.88 in the Scan mode m / z72 ion chromatogram.

[0093] [GC / MS measurement conditions] GC / MS measurements were performed on analytical samples prepared using 1,3-butylene glycol products in the examples and comparative examples under the following conditions. An Agilent 7890A / 5975C analyzer (manufactured by Agilent Technologies, Inc.) was used.

[0094] • GC: Conditions for gas chromatography analysis Analytical sample: A mixture was prepared by mixing 1,3-butylene glycol product with an aqueous solution containing citric acid, trisodium citrate, sodium EDTA, and phenoxyethanol, so that the concentration of 1,3-butylene glycol product was 20% by mass, citric acid was 0.01% by mass, trisodium citrate was 0.04% by mass, sodium EDTA was 0.25% by mass, and phenoxyethanol was 0.7% by mass. The mixture was then allowed to stand at 50°C for 4 weeks to prepare the analytical sample. Analytical column: Agilent J&W GC column-HP-1MS (Column with dimethylpolysiloxane stationary phase, film thickness 1.0 μm x length 30 m x inner diameter 0.25 mm, manufactured by Agilent Technologies, Inc.) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction method: Split sample introduction method Sample introduction temperature: 250℃ Initial pressure at the inlet: 15.3 psi Control mode: Constant flow (Average linear velocity: 24.7 cm / sec) Split ratio: 20 Carrier gas: Helium Column gas flow rate: 1 mL / min, helium Total flow: 24mL / min • Conditions for mass spectrometry (MS) Ionization method: EI method Ionization voltage and current: 70 eV, 35 μA Ion source temperature: 230℃ Quadrupole temperature: 150℃ Interface temperature: 250℃ Measurement mode: Simultaneous SIM / Scan measurement Scan mass range: m / z 29~550 SIM monitor ion: m / z101, m / z55 Cycle time: 3.8 cycles / second

[0095] [DMDO Identification] The presence of the compound represented by formula (1) (2,4-dimethyl-1,3-dioxane, DMDO) in the peak appearing in the relative retention time range of 0.59 to 0.65 was confirmed by purchasing the compound, performing GC / MS measurements under the above conditions, and verifying the consistency of the retention times, as well as the presence or absence of peaks in the SIM mode m / z 101 ion chromatogram and SIM mode m / z 55 ion chromatogram. The analytical sample consisted of 1 g of DMDO diluted in a 20% aqueous solution of 1,3-butylene glycol mixed with 0.01 g of the internal standard (diethylene glycol dimethyl ether).

[0096] The DMDO content in the analytical samples for Examples 1-4 and Comparative Examples 1-2 was 9.05 ppm, 7.42 ppm, 5.05 ppm, 2.64 ppm, below detection limit, and 13 ppm, respectively. These DMDO contents were calculated using a calibration curve prepared by mixing 1 g of a sample prepared by diluting DMDO with a 20% aqueous solution of 1,3-butylene glycol to an appropriate concentration with 0.01 g of an internal standard (diethylene glycol dimethyl ether).

[0097] [Identification of 1,3-butylene glycol] The peak appearing at a relative retention time of 0.72 to 0.88 was identified as the peak of 1,3-butylene glycol by performing GC / MS measurements using the same compound under the same conditions as described above, and confirming that the retention time and MS spectrum matched. The analytical sample consisted of 1 g of the above compound mixed with 0.01 g of the internal standard (diethylene glycol dimethyl ether).

[0098] [Odor Test 1] Odor Test 1 was conducted by sensory evaluation in a room at 25°C, with four evaluators smelling the samples. Specifically, (1) 100 ml of the analytical samples (100 ml) from Examples 1-4 and Comparative Examples 1-2 under GC / MS measurement conditions were placed in wide-mouth reagent bottles (internal volume: 100 ml), sealed tightly, and left to stand at room temperature for approximately 120 minutes. (2) After that, the stopper of the wide-mouth reagent bottle was opened, the contents were transferred to a 300 ml wide-mouth beaker, 100 ml of pure water was added to make a total of 200 ml, the contents were stirred by shaking the beaker by hand, and the odor was quickly smelled. (3) Each evaluator smelled each sample according to the procedures in (1) and (2) above, assigned a score based on the evaluation below, and the average score was taken as the "Odor (Apple Odor) Test Score". [Odor (apple smell) intensity] 1: I don't smell any apple scent. 2: I can faintly smell apple. 3: I can smell apples.

[0099] [Odor Test 2] Odor Test 2 was conducted in the same manner as Odor Test 1, with points assigned based on the evaluation below, and the average value was taken as the "Odor (Pungent Odor) Test Score." [Odor (irritating odor) intensity] 1: No strong odor detected 2: A slight pungent odor is noticeable.

[0100] The apple odor intensity of Examples 1-4 and Comparative Example 1 was 1 or 2, and the apple odor intensity of Comparative Example 2 was 3. Furthermore, the irritating odor intensity of Examples 1-4 and Comparative Example 2 was 1, and the irritating odor intensity of Comparative Example 1 was 2. Therefore, it was confirmed that the 1,3-butylene glycol products of the present invention (Examples 1-4) did not have an apple odor or an irritating odor, whereas the 1,3-butylene glycol product of Comparative Example 1 did not have an apple odor but did have an irritating odor, and furthermore, the 1,3-butylene glycol product of Comparative Example 2 had an apple odor but did not have an irritating odor.

[0101] From the above results, it became clear that the 1,3-butylene glycol products of Examples 1 to 4 were less likely to produce apple odor and pungent odor when incorporated into cosmetic compositions. Furthermore, from a comparison of Comparative Example 2 with Examples 1 to 4 and Comparative Example 1, it became clear that the apple odor could be reduced by improving the manufacturing method of the 1,3-butylene glycol product, particularly by increasing the water content in the hydrogenated raw material to a certain extent, and by increasing the amount of discharged material in the high-boiling point distillation process and the dealkalization process. On the other hand, it became clear that if these conditions were applied excessively, a product like the 1,3-butylene glycol product of Comparative Example 1 could be obtained, which would produce an odor different from apple odor (pungent odor) when incorporated into cosmetic compositions.

[0102] This pungent odor is thought to originate from the cosmetic composition itself. In Examples 1 to 4, certain by-products contained in the obtained 1,3-butylene glycol products had a masking effect on the pungent odor originating from the cosmetic composition, and it is thought that the pungent odor was suppressed by including a certain amount of these by-products. On the other hand, in Comparative Example 1, the amount of the above-mentioned by-product in the obtained 1,3-butylene glycol product was small, and it is thought that the masking effect on the pungent odor was insufficient, resulting in the generation of the pungent odor.

[0103] In summary, the structure of this disclosure and its variations are described below. [1] A 1,3-butylene glycol product having an area ratio of 10 to 280 as shown by the following formula. Area ratio = Peak x Area / 1,3BG Peak Area × 10 6 Peak X Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​Peak X appearing in the SIM mode m / z101 ion chromatogram within the range of relative retention time of 0.59 to 0.65 is defined as the area of ​​Peak X. 1,3BG Peak Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard diethylene glycol dimethyl ether peak is set to 1.0, this is the area of ​​the 1,3-butylene glycol peak that appears in the range of relative retention time from 0.72 to 0.88 in the Scan mode m / z72 ion chromatogram. [Conditions for gas chromatography analysis] Analytical sample: An analytical sample prepared by mixing 1,3-butylene glycol product with an aqueous solution containing citric acid, trisodium citrate, sodium EDTA, and phenoxyethanol, so that the concentration of 1,3-butylene glycol product was 20% by mass, citric acid was 0.01% by mass, trisodium citrate was 0.04% by mass, sodium EDTA was 0.25% by mass, and phenoxyethanol was 0.7% by mass, and then allowing the mixture to stand at 50°C for 4 weeks. Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction method: Split sample introduction method Sample introduction temperature: 250℃ Initial pressure at the inlet: 15.3 psi Control mode: Constant flow (Average linear velocity: 24.7 cm / sec) Split ratio: 20 Carrier gas: Helium Column gas flow rate: 1 mL / min, helium Total flow: 24mL / min • Conditions for mass spectrometry (MS) Ionization method: EI method Ionization voltage and current: 70 eV, 35 μA Ion source temperature: 230℃ Quadrupole temperature: 150℃ Interface temperature: 250℃ Measurement mode: Simultaneous SIM / Scan measurement Scan mass range: m / z 29~550 SIM monitor ion: m / z101, m / z55 Cycle time: 3.8 cycles / second [2] The 1,3-butylene glycol product according to [1], wherein the above area ratio is 270 or less, 260 or less, 250 or less, 240 or less, 230 or less, 220 or less, 210 or less, 200 or less, 185 or less, 170 or less, 155 or less, 145 or less, 135 or less, 125 or less, 110 or less, 100 or less, 90 or less, 80 or less, or 70 or less. [3] The 1,3-butylene glycol product according to [1] or [2], wherein the area ratio of the above-mentioned peak X is 20 or more, 30 or more, 40 or more, or 45 or more. [4] A 1,3-butylene glycol product according to at least one selected from [1] to [3], comprising a compound that, in gas chromatography analysis under the above conditions, has a peak in the SIM mode m / z 101 ion chromatogram and a peak in the SIM mode m / z 55 ion chromatogram, as a component corresponding to peak X that appears in the relative retention time range of 0.59 to 0.65. [5] A 1,3-butylene glycol product according to at least one selected from [1] to [4], comprising the compound of formula (1) as the component corresponding to peak X, which appears in the range of 0.59 to 0.65 relative retention times. [6] A 1,3-butylene glycol product according to at least one selected from [1] to [5], wherein, in gas chromatography analysis under the above conditions, the DMDO content in the analytical sample is 12.5 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, or 5 ppm or less. [7] A 1,3-butylene glycol product according to at least one selected from [1] to [6], wherein, in gas chromatography analysis under the above conditions, the DMDO content in the analytical sample is greater than 0 ppm, 0.1 ppm or more, 0.5 ppm or more, 1 ppm or more, 2 ppm or more, or 2.5 ppm or more. [8] A 1,3-butylene glycol product according to at least one selected from [1] to [7], wherein the area percentage of the 1,3-butylene glycol peak in gas chromatography analysis under the following conditions is 99.5% or higher, 99.7% or higher, 99.8% or higher, or 99.9% or higher. (Conditions for gas chromatography analysis) Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction temperature: 250℃ Carrier gas: Helium Column gas flow rate: 1 mL / min Detector and detection temperature: Flame ionization detector (FID), 280°C [9] A 1,3-butylene glycol product according to at least one selected from [1] to [8], wherein the 1,3-butylene glycol in the 1,3-butylene glycol product is (1) a reduced form of acetaldol, (2) a hydrolysate of 1,3-butylene oxide, (3) a selective hydrogenated product of erythritol, (4) a selective hydrate adduct to butadiene, (5) a hydride of n-butanal-3-one, (6) a hydride of 1-butanol-3-one, (7) a hydride of 3-hydroxy-1-butanoic acid, (8) a hydride of β-butyrolactone, or (9) a hydride of diketene.

[10] A 1,3-butylene glycol product according to at least one selected from [1] to [9], wherein the 1,3-butylene glycol in the 1,3-butylene glycol product is a reduced form of acetaldols.

[11] A 1,3-butylene glycol product according to at least one selected from [1] to

[10] , wherein the 1,3-butylene glycol in the 1,3-butylene glycol product is a reduced form of at least one compound selected from the group consisting of acetaldol, paraaldol, and aldoxane.

[12] A 1,3-butylene glycol product according to at least one selected from [1] to

[11] , wherein the 1,3-butylene glycol in the 1,3-butylene glycol product is obtained by hydrogenation reduction of a hydrogenated raw material containing acetaldols.

[13] The 1,3-butylene glycol product according to

[12] , wherein the acetaldol content in the hydrogenated raw material is 80% by mass or less, 60% by mass or less, or 50% by mass or less.

[14] A 1,3-butylene glycol product according to

[12] or

[13] , wherein the hydrogenated raw material contains water.

[15] A 1,3-butylene glycol product according to at least one selected from

[12] to

[14] , wherein the water content in the hydrogenated raw material is 10% by mass or more, 25% by mass or more, 40% by mass or more, more than 50% by mass, or 55% by mass or more.

[16] The 1,3-butylene glycol product according to

[15] , wherein the water content in the hydrogenated raw material is 80% by mass or less, 70% by mass or less, or 60% by mass or less.

[17] A humectant comprising a 1,3-butylene glycol product as described in at least one of [1] to

[16] .

[18] A cosmetic composition comprising a 1,3-butylene glycol product as described in at least one of [1] to

[16] . [Explanation of symbols]

[0104] A: Dehydration tower B: Desalination tower C: High-boiling point distillation column D: Alkaline reactor E: Dealkalization tower F: Product distillation column A-1, B-1, C-1, E-1, F-1: Capacitors A-2, C-2, F-2: Reboiler X-1: Crude 1,3-butylene glycol X-2: Water (drainage) X-3: Salts, high-boiling substances, and parts of 1,3-butylene glycol X-4: High-boiling point substances and parts of 1,3-butylene glycol X-5: Caustic soda, high-boiling point substances, and parts of 1,3-butylene glycol X-6: Low boiling point substances and parts of 1,3-butylene glycol Y: 1,3-Butylene glycol products

Claims

1. A 1,3-butylene glycol product having an area ratio of 10 or more and 280 or less, as shown by the following formula. Area ratio = Peak x Area / 1.3BG Peak Area × 10 ６ Peak X Area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​Peak X appearing in the SIM mode m / z 101 ion chromatogram within the range of 0.59 to 0.65 is defined as the area of ​​Peak X. 1,3-BG peak area: In gas chromatography analysis under the following conditions, when the relative retention time of the internal standard substance, diethylene glycol dimethyl ether, is set to 1.0, the area of ​​the 1,3-butylene glycol peak appearing in the range of 0.72 to 0.88 in the Scan mode m / z 72 ion chromatogram. [Conditions for gas chromatography analysis] Analytical sample: An analytical sample prepared by mixing 1,3-butylene glycol product with an aqueous solution containing citric acid, trisodium citrate, sodium EDTA, and phenoxyethanol, so that the concentration of 1,3-butylene glycol product was 20% by mass, citric acid was 0.01% by mass, trisodium citrate was 0.04% by mass, sodium EDTA was 0.25% by mass, and phenoxyethanol was 0.7% by mass, and then allowing the mixture to stand at 50°C for 4 weeks. Analytical column: Column with dimethylpolysiloxane stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) Heating conditions: Heat from 80°C to 120°C at a rate of 5°C / min, then heat to 160°C at a rate of 2°C / min and hold for 2 minutes. Further heat to 230°C at a rate of 10°C / min and hold at 230°C for 18 minutes. Sample introduction method: Split sample introduction method Sample introduction temperature: 250°C Initial pressure at the injection port: 15.3 psi Control mode: Constant flow (Average linear velocity: 24.7 cm / sec) Split ratio: 20 Carrier gas: Helium Column gas flow rate: 1 mL / min, helium Total flow rate: 24mL / min • Mass spectrometry (MS) conditions Ionization method: EI method Ionization voltage and current: 70 eV, 35 μA Ion source temperature: 230°C Quadrupole temperature: 150℃ Interface temperature: 250°C Measurement mode: Simultaneous SIM / Scan measurement Scan mass range: m / z 29 to 550 SIM monitor ions: m / z 101, m / z 55 Cycle time: 3.8 cycles / second

2. The 1,3-butylene glycol product according to claim 1, comprising a compound that, in gas chromatography analysis under the above conditions, has a peak in the SIM mode m / z 101 ion chromatogram and a peak in the SIM mode m / z 55 ion chromatogram, as a component corresponding to peak X that appears in the relative retention time range of 0.59 to 0.

65.

3. The component corresponding to peak X, which appears in the relative retention time range of 0.59 to 0.65, is given by the following formula (1): 【Chemistry 1】 A 1,3-butylene glycol product according to claim 1 or 2, comprising the compound.

4. The 1,3-butylene glycol product according to claim 1 or 2, wherein the 1,3-butylene glycol in the 1,3-butylene glycol product is a reduced form of at least one compound selected from the group consisting of acetaldol, paraaldol, and aldoxane.

5. A humectant comprising the 1,3-butylene glycol product according to claim 1 or 2.

6. A cosmetic composition comprising the 1,3-butylene glycol product according to claim 1 or 2.

Images