Preservative composition

Abstract

To provide a preservative composition having improved solubility of a para-hydroxybenzoate ester in water.SOLUTION: There is provided a preservative composition which comprises a powdered base material, a para-hydroxybenzoic ester and an emulsifier, wherein the powdered base material contains a sorbitol having a specific surface area of 1 m2 / g or more by the one-point BET method and a pore volume of 0.2 mL / g or more by the mercury injection method, the emulsifier has an HLB value of 9 or more, the ratio of the para-hydroxybenzoic ester is 1 to 65 pts.wt. based on 100 pts.wt.of the powdered base material and the para-hydroxybenzoic ester and the emulsifier are supported in the pores of the powdered base material.SELECTED DRAWING: None

Description

[Technical Field] 【0001】 The present invention relates to a preservative composition in which the solubility of parahydroxybenzoic acid esters has been improved. [Background technology] 【0002】 Parahydroxybenzoic acid esters (PHA) are widely used as preservatives in foods and cosmetics due to their excellent antibacterial properties and low irritancy. However, PHA has extremely low solubility in water (Non-Patent Literature 1) and a slow dissolution rate, which can lead to prolonged dissolution and crystal precipitation depending on the amount added. Therefore, when adding PHA to products requiring preservation, it is common practice to use alcohols such as ethanol as a solubilizer. 【0003】 While the solubility of preservatives can be improved to some extent by using solubilizers, even with preservative compositions using solubilizers, crystals may precipitate when added to certain preservatives or during low-temperature storage, indicating a need for further improvement. 【0004】 Furthermore, it is generally known that the dissolution rate improves with increasing surface area, and improving the dissolution rate by micronizing poorly water-soluble substances such as p-hydroxybenzoic acid esters has also been investigated (Non-Patent Literature 2). However, micronization requires special equipment such as jet mills and supercritical crystallization apparatuses, and has not been an easily implementable method. 【0005】 On the other hand, studies are also being conducted to improve solubility through methods other than micronization. Patent Document 1 describes an antifungal agent characterized by having a eutectic mixture of two or more types of parahydroxybenzoic acid esters as its main component. Although this antifungal agent significantly improves solubility in water by forming a eutectic mixture of multiple parahydroxybenzoic acid esters, it has the drawbacks of being a liquid and requiring a complex manufacturing process. 【0006】 Therefore, there was a need for a preservative composition that improved the solubility of parahydroxybenzoic acid esters without requiring special equipment or complex processes. [Prior art documents] [Patent Documents] 【0007】 [Patent Document 1] Special Publication No. 37-17994 [Non-patent literature] 【0008】 [Non-Patent Document 1] The Science of Preservatives and Bacteria in Cosmetics and Pharmaceuticals (Fragrance Journal Co., Ltd., 1984) [Non-Patent Document 2] Nanocrystalline formulations of poorly soluble drugs (Drug Delivery System 30-2, 2015) [Overview of the project] [Problems that the invention aims to solve] 【0009】 The present invention aims to provide a preservative composition in which the solubility of parahydroxybenzoic acid esters in water is improved. [Means for solving the problem] 【0010】 As a result of diligent research, the inventors of the present invention have found that the above problems can be solved by supporting a parahydroxybenzoic acid ester and a specific emulsifier on a powdered substrate containing a specific sorbitol, and have completed the present invention. 【0011】 In other words, the present invention relates to a preservative composition comprising a powdered base material, a parahydroxybenzoic acid ester, and an emulsifier, wherein the powdered base material has a specific surface area of ​​1 m² as measured by the BET single-point method. 2The present invention provides a preservative composition containing sorbitol in an amount of 0.2 mL / g or more and with a pore volume of 0.2 mL / g or more as determined by mercury intrusion, an HLB value of 9 or more for the emulsifier, a proportion of parahydroxybenzoic acid ester of 1 to 65 parts by weight per 100 parts by weight of the powdered base material, and the parahydroxybenzoic acid ester and emulsifier supported in the pores of the powdered base material. 【0012】 Furthermore, the present invention prepares a solution by dissolving a parahydroxybenzoic acid ester and an emulsifier with an HLB value of 9 or higher in a solvent, and the specific surface area of ​​the solution obtained by the BET single-point method is 1 m². 2 The present invention also provides a method for producing a preservative composition, characterized by adding a dissolving solution to a powdered base material containing sorbitol in a quantity of 0.2 mL / g or more and having a pore volume of 0.2 mL / g or more as determined by mercury intrusion, in an amount of 1.5 to 125 parts by weight per 100 parts by weight of the powdered base material. [Modes for carrying out the invention] 【0013】 The present invention will be described in detail below. The parahydroxybenzoic acid esters that can be used in the preservative composition of the present invention are not particularly limited, but methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, isopropyl parahydroxybenzoate, butyl parahydroxybenzoate, isobutyl parahydroxybenzoate, and benzyl parahydroxybenzoate (hereinafter sometimes referred to as MP, EP, PP, IPP, BP, IBP, and BeP, respectively) are examples of preferred parahydroxybenzoic acid esters. Among these, methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, isopropyl parahydroxybenzoate, and butyl parahydroxybenzoate are preferred in terms of solubility in water, and butyl parahydroxybenzoate is more preferred in terms of excellent preservative effect. Two or more of these parahydroxybenzoic acid esters may be used in combination. 【0014】 The proportion of parahydroxybenzoic acid ester in the preservative composition of the present invention is 1 to 65 parts by weight, preferably 5 to 60 parts by weight, more preferably 10 to 55 parts by weight, and even more preferably 15 to 52 parts by weight, per 100 parts by weight of the powdered base material. If the proportion of parahydroxybenzoic acid ester relative to the powdered base material is small, the amount of sorbitol, which is the powdered base material in the preservative composition, becomes relatively large, which tends to change the taste and physical properties of the substance to which it is added. The proportion should be determined in consideration of the amount of parahydroxybenzoic acid ester to be added and the amount of sorbitol that is permissible in that application, depending on the application of the preservative composition. If the proportion of parahydroxybenzoic acid ester relative to the powdered base material exceeds 65 parts by weight, the preservative composition will contain parahydroxybenzoic acid ester that is not supported in the pores of the powdered base material, which tends to worsen the solubility of the preservative composition in water. 【0015】 The emulsifier used in the preservative composition of the present invention can be any emulsifier with an HLB value of 9 or higher, preferably with an HLB value of 10 to 18, and more preferably with an HLB value of 11 to 16. 【0016】 Specific examples of emulsifiers include enzymatically hydrolyzed lecithin, glycerol fatty acid esters, polyglycerol fatty acid esters, propylene glycol fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters. Among these, enzymatically hydrolyzed lecithin and polyglycerol fatty acid esters are preferred in terms of solubility in water, and enzymatically hydrolyzed lecithin is preferred in terms of emulsifying power. 【0017】 Enzyme-hydrolyzed lecithin may be derived from plants such as soybeans, rapeseed, or sunflower, or from animals such as egg yolk. It may also be fractional enzyme-hydrolyzed lecithin with adjusted phospholipid concentration, or hydrogenated enzyme-hydrolyzed lecithin. Two or more of these enzyme-hydrolyzed lecithins may be used in combination. 【0018】 The proportion of the emulsifier in the preservative composition of the present invention is not particularly limited, but it is preferably 0.04 to 0.5 parts by weight, more preferably 0.06 to 0.4 parts by weight, and even more preferably 0.08 to 0.35 parts by weight with respect to 1 part by weight of the para-hydroxybenzoic acid ester. When the proportion of the emulsifier is less than 0.04 parts by weight with respect to 1 part by weight of the para-hydroxybenzoic acid ester, the dispersion in the addition target deteriorates, and as a result, the solubility of the preservative composition tends to deteriorate. When it exceeds 0.5 parts by weight, the amount of the emulsifier in the preservative composition becomes relatively large, and thus the taste and physical properties in the addition target tend to change. 【0019】 The powdered base material used in the preservative composition of the present invention has a specific surface area by the BET single-point method of 1 m 2 / g or more and a pore volume by the mercury intrusion method of 0.2 mL / g or more, and contains sorbitol (which may be referred to as porous sorbitol in this specification). The powdered base material preferably consists only of porous sorbitol. 【0020】 The porous sorbitol used in the present invention may be adjusted so that the average particle diameter is within a specific range. The average particle diameter at that time is measured with a laser diffraction particle size distribution measuring device (MasterSizer (registered trademark) 3000, manufactured by Malvern), and is preferably 1 to 600 μm, more preferably 20 to 550 μm, and even more preferably 30 to 500 μm. 【0021】 The porous sorbitol can be produced, for example, by kneading molten sorbitol and ethanol and then drying under reduced pressure. In one preferred embodiment, the method for producing the porous sorbitol of the present invention includes the following steps: a) A step of supplying molten sorbitol and ethanol into a kneading device, b) A step of kneading the molten sorbitol and ethanol in the kneading device while maintaining the temperature at 50 to 78 °C, and c) A step of removing ethanol by drying the kneaded product obtained in b) under reduced pressure at 25 to 90 °C and 100 to 30000 Pa. 【0022】 Furthermore, the above manufacturing method will be explained in more detail. First, in step a), 10 to 70 parts by weight of molten sorbitol and 30 to 90 parts by weight of ethanol are supplied into the kneading apparatus. Preferably, the amount supplied into the kneading apparatus is 15 to 68 parts by weight of molten sorbitol and 32 to 85 parts by weight of ethanol, and more preferably 20 to 65 parts by weight of molten sorbitol and 35 to 80 parts by weight of ethanol. 【0023】 The water content in the ethanol used in step a) is, for example, 10% by weight or less. Preferably, the water content in the ethanol is 8% by weight or less, more preferably 5% by weight or less, even more preferably 2% by weight or less, and particularly preferably 0% by weight (ethanol only). The lower the water content in the ethanol, the more likely it is that the specific surface area of ​​the porous sorbitol produced will improve. 【0024】 Next, in step b), the molten sorbitol and ethanol in the kneading apparatus are kneaded while maintaining a temperature of 50 to 78°C. By maintaining the temperature in the kneading apparatus at 50 to 78°C, the molten sorbitol in the kneading apparatus does not solidify rapidly, and the molten sorbitol and ethanol can be kneaded while suppressing the volatilization of ethanol. The temperature in the kneading apparatus is preferably 55 to 78°C, and more preferably 60 to 75°C. 【0025】 In step c), the kneaded mixture obtained in step b) is dried under reduced pressure at 25-90°C and 100-30000 Pa to remove ethanol and obtain porous sorbitol. Vacuum drying is performed using a vacuum dryer such as an evaporator. The porous sorbitol obtained in step c) can be crushed or granulated using a blender or the like to obtain a powder. 【0026】 The equipment used in the production of the porous sorbitol described above includes kneaders such as KRC kneaders, horizontal kneaders, and vertical kneaders. In terms of quality, KRC kneaders and horizontal kneaders are preferred, and KRC kneaders are more preferred in terms of their excellent balance with production efficiency. 【0027】 The specific surface area of ​​the powdered substrate that can be used in the present invention is 1 m². 2 / g or more, preferably 5m 2 / g or more, more preferably 7-30m 2 / g is more preferably 8-15m 2 It is / g. 【0028】 In this invention, the specific surface area refers to the value measured by the BET single-point method using, for example, a MONOSORB (manufactured by Yuasa Ionics Co., Ltd.) or an equivalent specific surface area measuring device. For example, the specific surface area can be measured under the following measurement conditions. [Measurement conditions] Method: BET style one point method Carrier gas: Nitrogen-helium mixture (N2:He=30:70) Measured gas flow rate: 15cc / min Degassing conditions: 60°C, 20 minutes 【0029】 The pore volume of the powdered substrate that can be used in the present invention is 0.2 mL / g or more, preferably 0.3 mL / g or more, more preferably 0.4 to 2.5 mL / g, and more preferably 0.5 to 1.5 mL / g. 【0030】 In this invention, pore volume refers to the value measured by the mercury intrusion method using, for example, a Pascal 240 (manufactured by Thermo Fisher Scientific) or an equivalent pore volume measuring device. 【0031】 The preservative composition of the present invention may contain parahydroxybenzoic acid esters and emulsifiers that are not supported in the pores of the powdered base material, but the amount is preferably small, and it is more preferable that all of the parahydroxybenzoic acid esters and emulsifiers are supported in the pores of the powdered base material. Furthermore, as the amount of parahydroxybenzoic acid esters and emulsifiers that are not supported in the pores of the powdered base material increases, the fluidity tends to deteriorate, so it is preferable to use a powder with a fluidity of 30 to 60° angle of repose. The angle of repose is more preferably 35 to 58°, and even more preferably 40 to 55°. If the angle of repose is less than 30°, the scattering tendency tends to increase, and if the angle of repose exceeds 60°, the fluidity tends to deteriorate. 【0032】 In this invention, the angle of repose refers to the value measured by the cylindrical rotation method using, for example, a cylindrical rotation method angle of repose measuring instrument (Tsutsui Rikagakukikai Co., Ltd.) or an equivalent measuring instrument. 【0033】 Next, the method for producing the preservative composition of the present invention will be described. 【0034】 The preservative composition of the present invention is manufactured by supporting a parahydroxybenzoic acid ester and an emulsifier on a powdered base material. More specifically, the parahydroxybenzoic acid ester and the emulsifier are mixed with a solvent capable of dissolving both components to form a solution (hereinafter simply referred to as the solution), and the specific surface area obtained by the BET single-point method is 1 m². 2 An example of this method involves supporting the sorbitol on a powdered substrate containing sorbitol at a concentration of 0.2 mL / g or more and a pore volume of 0.2 mL / g or more as determined by mercury intrusion. When this method is adopted, preferred solvents that can be used to prepare the dissolution include alcohols. Examples of usable alcohols include methanol, ethanol, propanol, isopropanol, glycerol, ethylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, etc. Among these, ethanol, isopropanol, and propylene glycol are preferred from the standpoint of safety, and ethanol is more preferred from the standpoint of availability. Two or more of these alcohols may be used in combination. 【0035】 Furthermore, the above alcohol may contain water, in which case the water content is preferably 15% by weight or less, more preferably 12% by weight or less, and even more preferably 0.01 to 10% by weight. If the water content exceeds 15% by weight, the parahydroxybenzoic acid ester or emulsifier tends not to dissolve completely. In this specification and claims, when "alcohol" or "ethanol" is used without further specification, it includes both alcohols containing water and those that do not. 【0036】 The proportion of p-hydroxybenzoic acid ester in the solution is preferably 50 parts by weight or more, more preferably 80 parts by weight or more, even more preferably 100 parts by weight or more, and most preferably 110 parts by weight or more, per 100 parts by weight of solvent. The upper limit of the proportion of p-hydroxybenzoic acid ester is sufficient as long as it is dissolved in the solvent used. For example, if ethanol at 95 degrees Celsius is selected as the solvent and butyl p-hydroxybenzoate is selected as the p-hydroxybenzoic acid ester, the upper limit is approximately 210 parts by weight. 【0037】 In the method of the present invention, 1.5 to 125 parts by weight of the dissolving solution is added to 100 parts by weight of the powdered base material. By the method of the present invention, a preservative composition of the present invention can be obtained in which the ratio of parahydroxybenzoic acid ester to 100 parts by weight of the powdered base material is a desired ratio, and the parahydroxybenzoic acid ester and emulsifier are supported in the pores of the powdered base material. 【0038】 The means of adding the dissolving solution to the powdered substrate are not limited, and one example is a method of mixing the powdered substrate while adding the dissolving solution little by little. More specifically, examples include a method of mixing while dropping the dissolving solution using a dropper or the like, and a method of mixing while spraying the dissolving solution using equipment known in the art, such as a stirring and mixing granulator or a fluidized bed granulator. 【0039】 In the production of the preservative composition of the present invention, the solvent contained in the obtained preservative composition may be used as is, or it may be removed using general equipment such as a drying apparatus or evaporator, depending on the purpose. 【0040】 The preservative composition of the present invention obtained in this manner can be used in products that use an aqueous solvent in the product or during the manufacturing process. Depending on the intended use of the parahydroxybenzoic acid ester, it can be used in a variety of products such as food and beverages, cosmetics, cleaning and disinfecting agents, fragrances, deodorizers, preservatives, pharmaceuticals, quasi-drugs, inks, adhesives, paints, cooling agents, insect repellents, nonwoven fabrics, building materials, and daily necessities. [Examples] 【0041】 The present invention will be described in detail below with reference to examples, but the present invention is not limited in any way to these examples. 【0042】 Test Example 1 Preparation of powdered substrate The materials listed below were melt-kneaded in the proportions (by weight) and under the conditions shown in Table 1. The resulting crystallized mixture was dried under reduced pressure using a rotary evaporator under the conditions shown in Table 1 to obtain powdered substrate 1. The obtained powdered substrate was pulverized in the blender shown below at 15,700 rpm for 30 seconds. The specific surface area, pore volume, and average particle size of powdered substrates 1 and 6-7 after pulverization were measured under the following conditions. Powdered substrates 2-5 did not crystallize when melt-kneaded for 30 minutes, so the evaluation was terminated without measuring the specific surface area, pore volume, and average particle size. 【0043】 <Material> • Sorbitol 1: Powdered sorbitol "Ueno" 20M (manufactured by Ueno Food Techno Co., Ltd., sorbitol purity 92%) • Sorbitol 2: Pertec® SI 150 (Merck, sorbitol purity 98.4%) • Maltitol: Powdered maltitol "Ueno" 60M (manufactured by Ueno Food Techno Co., Ltd.) · Xylitol: primary xylitol (reagent, manufactured by Fujifilm Wako Pure Chemical Corporation) · Ethanol: fermented ethanol (95 degrees, manufactured by Daiichi Alcohol Co., Ltd., ethanol 92.3% by weight) · Ion-exchanged water <Kneading device> · KRC: KRC kneader (S2 type, manufactured by Kurimoto Iron Works, Ltd.) · Horizontal type: horizontal kneader (semi KC-6 type, manufactured by Satake Corporation) <Blender> · Blender (16Speed Blender, manufactured by Oster) 【0044】 Measurement of specific surface area The powdered base material was placed in a measuring cell (volume: 1.7 cm 3 ) to a level of about 1 / 2 volume, and measured under the following conditions using a BET type specific surface area meter (MONOSORB, manufactured by Yuasa Ionics Co., Ltd.). [Measurement conditions] Method: BET one-point method Carrier gas: nitrogen·helium mixed gas (N2:He = 30:70) Measurement gas flow rate: 15 cc / min Degassing conditions: 60°C, 20 minutes 【0045】 Measurement of pore volume The pore volume was measured using a mercury porosimeter (Pascal 240, manufactured by Thermo Fisher Scientific). 【0046】 Measurement of average particle diameter The average particle diameter was measured using a laser diffraction particle size distribution measuring device (Mastersizer (registered trademark) 3000, manufactured by Malvern). 【0047】 【Table 1】 ​​​​​​​​ Using the materials listed below, the emulsifier and ethanol were mixed in the proportions (by weight) shown in Table 2. Then, the parahydroxybenzoic acid ester was heated and dissolved at 50°C to prepare solutions 1 to 10. Solution 10 was not used in subsequent tests because the emulsifier did not dissolve in the ethanol. • BP (Butyl p-hydroxybenzoate, manufactured by Ueno Pharmaceutical Co., Ltd.) • IBP (Isobutyl p-hydroxybenzoate, manufactured by Ueno Pharmaceutical Co., Ltd.) • Emulsifier 1 (Enzyme-hydrolyzed lecithin SLP(registered trademark)-LPC70, HLB value = 12, manufactured by Tsuji Oil Co., Ltd.) • Emulsifier 2 (Polyglycerin fatty acid ester, SY Glystar (registered trademark) ML-750, HLB value = 15, manufactured by Sakamoto Pharmaceutical Co., Ltd.) • Emulsifier 3 (Polyglycerin fatty acid ester, SY Glystar (registered trademark) MO-3S, HLB value = 8.8, manufactured by Sakamoto Pharmaceutical Co., Ltd.) • Emulsifier 4 (Polyglycerin fatty acid ester, Poem® PR300, HLB value = 0.5, manufactured by Riken Vitamin Co., Ltd.) • Emulsifier 5 (Soy lecithin, SLP® paste, HLB value = 5-7, manufactured by Tsuji Oil Co., Ltd.) • Solvent 1 (Fermented ethanol, 95% alcohol, manufactured by Nippon Alcohol Industry Co., Ltd.) • Solvent 2 (Isopropyl alcohol, reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) • Solvent 3 (Propylene glycol, reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 【0049】 [Table 2] 【0050】 Test Example 3 Mixability of the dissolving solution and water 100g of deionized water at 20°C was weighed into a beaker, and solutions 1-9 were added to achieve a p-hydroxybenzoic acid ester concentration of 150ppm. The mixture was stirred with a stirrer, but none of the solutions dissolved even after 48 hours. 【0051】 Examples 1-15 and Comparative Examples 1-4 Preparation of preservative composition 1 Using the powdered substrates and dissolving solutions prepared in Test Examples 1 and 2 above, preservative compositions were prepared in the proportions (weight %) shown in Table 3 using the stirring, mixing, and granulation apparatus described below (Examples 1-8 and Comparative Examples 1-2). <Equipment used and operating conditions> • Stirring, mixing, and granulation equipment (manufactured by Powrec Co., Ltd.) Liquid flow rate: 10 g / min Blade rotation speed: 250 rpm Cross screw rotation speed: 3000 rpm 【0052】 Preparation of preservative composition 2 Using the powdered substrates and parahydroxybenzoic acid ester solutions prepared in Test Examples 1 and 2 above, preservative compositions were prepared by adding the solution dropwise to the powdered substrate using a dropper and shaking it in the proportions (weight %) shown in Table 3 (Examples 9-13 and Comparative Examples 3-4). 【0053】 Preparation of preservative composition 3 Using the powdered substrate and parahydroxybenzoic acid ester solution prepared in Test Examples 1 and 2 above, the parahydroxybenzoic acid ester solution was added dropwise to the powdered substrate using a dropper in the proportions (weight %) shown in Table 3, and the mixture was shaken. The mixture was then dried under reduced pressure using a rotary evaporator to obtain the preservative composition (Examples 14 and 15). 【0054】 Evaluation of solubility of preservative compositions 100g of deionized water at 20°C was weighed into a beaker, and the preservative composition was added to achieve a concentration of 150ppm of parahydroxybenzoate ester. The time to dissolution was measured while stirring with a stirrer, and the results were evaluated according to the following criteria. As a control, the solubility of butyl parahydroxybenzoate powder alone was also evaluated in the same manner. The results are shown in Table 3. <Criteria for evaluating solubility> A: Dissolves within 5 minutes after addition. B: Dissolve within 4 hours, not just 5 minutes. C: Dissolves within 24 hours, exceeding 4 hours. D: Dissolve within 24 hours to 48 hours. E: It does not dissolve even after mixing for more than 48 hours. 【0055】 In all cases, the preservative compositions of the present invention showed a shorter dissolution time and improved solubility in water compared to the control. In contrast, the compositions of Comparative Examples 1 to 4 did not dissolve even after 48 hours, and their solubility did not improve compared to the control. 【0056】 Examples 16-17 and Comparative Example 5 Measurement of the angle of repose Using the powdered substrates and dissolving solutions prepared in Test Examples 1 and 2 above, preservative compositions were prepared by adding the para-hydroxybenzoic acid ester dissolving solution dropwise to the powdered substrate using a dropper while shaking, in the proportions (weight %) shown in Table 4. 150 mL of the obtained preservative composition was placed in a glass cylindrical container, and the angle of repose was measured using a cylindrical rotation angle of repose measuring instrument (Tsutsui Rikagakukikai Co., Ltd.) (Examples 16-17). The results are shown in Table 4. 【0057】 The preservative composition of the present invention was a powder with good fluidity, but the composition of Comparative Example 5 became a paste and no powder was obtained, making it impossible to measure the angle of repose. 【0058】 [Table 3] 【0059】 [Table 4]

Claims

[Claim 1] A preservative composition comprising a powdered base material, a parahydroxybenzoic acid ester, and an emulsifier, The powdered substrate has a specific surface area of ​​1 m² as measured by the BET single-point method. ２ It contains sorbitol in an amount of 0.2 mL / g or more, and a pore volume of 0.2 mL / g or more as determined by mercury intrusion method. A preservative composition in which the emulsifier has an HLB value of 9 or higher, the proportion of parahydroxybenzoic acid ester is 1 to 65 parts by weight per 100 parts by weight of the powdered base material, and the parahydroxybenzoic acid ester and emulsifier are supported in the pores of the powdered base material. [Claim 2] The preservative composition according to claim 1, wherein the p-hydroxybenzoate ester is one or more selected from the group consisting of methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, isopropyl p-hydroxybenzoate, butyl p-hydroxybenzoate, isobutyl p-hydroxybenzoate, and benzyl p-hydroxybenzoate. [Claim 3] The preservative composition according to claim 1, wherein the emulsifier is one or more selected from the group consisting of glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, propylene glycol fatty acid ester, sorbitan fatty acid ester, and enzymatically hydrolyzed lecithin. [Claim 4] The preservative composition according to claim 1, wherein the proportion of the emulsifier is 0.04 to 0.5 parts by weight per 1 part by weight of the parahydroxybenzoic acid ester. [Claim 5] The preservative composition according to claim 1, wherein the angle of repose is 30 to 60°. [Claim 6] A solution is prepared by dissolving a parahydroxybenzoic acid ester and an emulsifier with an HLB value of 9 or higher in a solvent, and the specific surface area of ​​this solution is 1 m² by the BET single-point method. ２ A method for producing a preservative composition, characterized by adding a dissolving solution to a powdered base material containing sorbitol in a quantity of 0.2 mL / g or more and having a pore volume of 0.2 mL / g or more as determined by mercury intrusion, in an amount of 1.5 to 125 parts by weight per 100 parts by weight of the powdered base material. [Claim 7] The manufacturing method according to claim 6, wherein the solvent is one or more selected from the group consisting of methanol, ethanol, propanol, isopropanol, glycerol, ethylene glycol, diethylene glycol, propylene glycol, and polyethylene glycol.

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