CN112218560A

CN112218560A - Sponge for beauty

Info

Publication number: CN112218560A
Application number: CN201980037514.5A
Authority: CN
Inventors: 严本朋哉
Original assignee: Toyopolymer Co Ltd
Current assignee: Toyopolymer Co Ltd
Priority date: 2018-06-08
Filing date: 2019-05-31
Publication date: 2021-01-12
Anticipated expiration: 2039-05-31
Also published as: WO2019235374A1; KR20210018293A; JP7011824B2; JP2019209039A; KR102613473B1

Abstract

The cosmetic sponge (10) is composed of a porous elastomer made of polyurethane having a plurality of pores, and in the section (100) thereof, the average value of the major axes of the pores is 60 [ mu ] m or less and the standard deviation of the major axes of the pores is 60 [ mu ] m or less.

Description

Sponge for beauty

Technical Field

The invention relates to a cosmetic sponge. The present application claims priority of japanese invention patent application No. 2018-110308, which was filed on 8/6/2018, and incorporates all the contents described in the japanese invention patent application.

Background

The sponge is used for cosmetic purposes such as makeup and beauty. Sponges are widely used, for example, as application tools for applying liquid cosmetics to skin, makeup removers for cleansing the face or removing makeup from the skin, and the like. Examples of such sponges are disclosed in patent document 1 and patent document 2.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2007-330771

Patent document 2: japanese patent laid-open publication No. 2015-116370

Disclosure of Invention

Technical problem to be solved by the invention

The sponge used for makeup or makeup removal or other makeup applications is used in direct contact with the skin, and the feeling of use varies greatly depending on the type of sponge, and the feel of the skin, the ease of makeup application, the ease of makeup removal, and the like vary greatly depending on the type of sponge. Among them, a cosmetic sponge having good feeling of use such as skin touch, easy use for makeup application or makeup removal, and good finish has been demanded.

In the case of coating a cosmetic such as foundation with a sponge, the makeup finish degree of makeup may show a significant difference depending on the sponge used. In order to achieve a natural finish, a sponge that can thin and spread foundation evenly on the skin is desired. In addition, a sponge is also used for facial cleansing in beauty care and the like. In such applications, a sponge that is mild to the skin and easy to clean up dirt is desired.

Therefore, it is an object to provide a cosmetic sponge which is excellent in feeling of use and suitable for cosmetic uses such as makeup and beauty.

Technical solution for solving technical problem

The cosmetic sponge of the present invention is composed of a porous elastomer made of polyurethane having a plurality of pores, and in the cross section thereof, the average value of the major axes of the pores is 60 μm or less and the standard deviation of the major axes of the pores is 60 μm or less.

The average value of the major axes of the pores of the cosmetic sponge is 60 μm or less, and the pores are very fine. The standard deviation of the major axes of the pores is 60 μm or less, and the variation in pore size is small. Therefore, a sponge having fine pores and high uniformity can be provided. For example, when such a sponge is used as a cosmetic sponge for applying a foundation, the foundation can be uniformly transferred onto the skin, and the makeup can be performed with less makeup spots and with good finish. In addition, the foundation is uniformly transferred, and as a result, a finished makeup can be made that the foundation is easily spread uniformly and is smooth. In addition, when the sponge is used for cleansing in beauty care, the sponge can be suitably used as a sponge which can favorably adsorb fine dirt and has a good touch to the skin and excellent cleansing properties.

In the cosmetic sponge, the maximum value of the minor axis of the pores in the cross section is preferably 120 μm or more. When the pores of the sponge are made thin, the skeleton structure of the sponge surrounding the pores tends to be thin and soft, and the strength and elasticity of the sponge tend to be reduced. In order to maintain the strength and elasticity of the sponge at a certain level, it is preferable that a part of the sponge has a thick skeleton portion.

A sponge having an average value of the major axes of pores of 60 μm or less and a maximum value of the minor axes of pores of 120 μm or more has a feature that pores having a small diameter and pores having a large diameter are present at the same time. The internal structure is mainly composed of a small-diameter air hole and partially includes a large-diameter air hole. In this way, since there are many pores having a small diameter as a whole, the maximum value of the short diameter of the pores is much larger than the average value of the long diameter (naturally, the long diameter of the pores having such a short diameter is larger) although the average value of the long diameter of the pores is small.

In such a structure, the sponge has an effect of increasing the strength and elasticity of the sponge by partially including pores having a large outer diameter in a part of the internal structure of the sponge. This is because the thickness of the skeleton structure of the sponge surrounding the portion of the air holes having a large outer diameter tends to be larger than the thickness of the skeleton structure surrounding the portion of the air holes having a small outer diameter. Such a thick skeleton structure of the sponge surrounding the portion of the large outer diameter air hole functions as a support column supporting the internal structure of the sponge, whereby the strength and elasticity of the sponge are increased, and the sponge is less likely to lose its resilience. Further, by setting the average value of the major axes of the pores to 60 μm or less, a cosmetic with less makeup spots and good finish can be provided, and a sponge which is less likely to lose the springback capability can be provided. For this reason, the cosmetic sponge preferably has a maximum value of the minor axis of the pores in the cross section of 120 μm or more.

The cosmetic sponge preferably has 200 or more pores in a cross section of the sponge within a range of 10mm × 10 mm. Such a fine-meshed sponge having a large number of small pores makes it easy to provide a cosmetic sponge having less makeup spots or a cosmetic sponge having a better skin feel and superior cleanliness.

In the cosmetic sponge, the average value of the minor axes of the pores in the cross section is preferably 20 to 35 μm, and the standard deviation of the minor axes of the pores is preferably 15 to 40 μm. By making the minor axis have a certain size, the volume of the cavity of the air hole can be maintained to a certain degree. Thus, a sufficient amount of liquid such as a cosmetic or oil can be contained in the pores. Therefore, the sponge is more suitable for cosmetic sponge.

Preferably, the ASKER FP hardness at 25 ℃ is 50 to 70 degrees inclusive. When the hardness of ASKER FP is 50 degrees or more, a sponge having excellent elasticity, sufficient strength, and little possibility of losing the resilience can be provided. Further, the ASKER FP hardness was 70 degrees or less, and the sponge was soft and had a good skin feel.

The cosmetic sponge is preferably used for cosmetic or cosmetology. The cosmetic sponge has fine pores and excellent uniformity, and thus can be suitably used for cosmetics or beauty.

Effects of the invention

The present invention provides a cosmetic sponge which is excellent in feeling of use and suitable for cosmetic use such as makeup or beauty.

Drawings

FIG. 1 is a view showing an example of a cosmetic sponge;

FIG. 2 is a photograph showing an example of a cross-section of a cosmetic sponge;

fig. 3 is a diagram of a processed image obtained by binarizing a part of a cross-sectional image of a cosmetic sponge;

FIG. 4 is a view for explaining the major and minor diameters of the air holes;

FIG. 5 is a view for explaining the major and minor diameters of the air holes;

fig. 6 is a diagram for explaining an example of image processing for removing noise;

fig. 7 is a diagram for explaining an example of image processing for removing noise;

FIG. 8 is a photograph showing a cross section of the cosmetic sponge of comparative example 1;

FIG. 9 is a photograph showing a cross-section of the cosmetic sponge of example 1;

FIG. 10 is a photograph showing a cross-section of the cosmetic sponge of example 2;

FIG. 11 is a photograph showing a cross section of the cosmetic sponge of example 3;

FIG. 12 is a photograph showing a cross section of the cosmetic sponge of example 4;

FIG. 13 is a photograph showing a transfer state of a foundation using the cosmetic sponge of comparative example 1; and

fig. 14 is a photograph showing a transfer state of a foundation using the cosmetic sponge of example 1.

Detailed Description

Next, an embodiment of the cosmetic sponge of the present invention will be described. The cosmetic sponge of the present invention is composed of a porous elastomer made of polyurethane having a plurality of pores, and has a cross section in which the average value of the major axes of the pores is 60 μm or less and the standard deviation of the major axes of the pores is 60 μm or less. Fig. 1 shows an example of a cosmetic sponge. Fig. 2 shows an example of a cross-sectional photograph showing the state of pores in the cosmetic sponge.

[ Components and production methods of cosmetic sponges ]

Referring to fig. 1 and 2, the cosmetic sponge 10 is made of a porous polyurethane elastomer 20 having a plurality of pores. The polyurethane forming the matrix of the cellular elastomer 20 can be made by polymerizing a polyol component and a polyisocyanate component.

The polyol component contains a high molecular weight polyol and a chain extender. Examples of high molecular weight polyols include: polyether polyols such as polypropylene glycol, polytetramethylene glycol and polymer polyols, polyester polyols such as adipate polyols and polycaprolactone polyols, polycarbonate polyols, polyolefin polyols, and the like. Examples of the chain extender include: low molecular weight glycols such as ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, and 3-methyl-1, 5-pentanediol.

The polyisocyanate component contains a polyisocyanate compound. Examples of the polyisocyanate contained in the polyisocyanate component include: aromatic isocyanates such as Toluene Diisocyanate (TDI), diphenylmethane-4, 4' -diisocyanate (MDI), Xylylene Diisocyanate (XDI), 1, 5-Naphthalene Diisocyanate (NDI), and tetramethylxylylene diisocyanate (TMXDI), alicyclic isocyanates such as isophorone diisocyanate (IPDI) and hydrogenated xylylene diisocyanate (H6XDI), and aliphatic isocyanates such as Hexamethylene Diisocyanate (HDI), (10- [5, 6-dihexyl-2- (8-isocyanatooctyl) -3-cyclohexen-1-yl ] -9-decylenoisocyanato) dimer acid diisocyanate, and norbornene diisocyanate (NBDI).

The above-mentioned polyol component may be used alone, or two or more of the above may also be used in combination. In addition, the polyisocyanate component may be used alone or in combination of two or more of the above. As the precursor of the polyurethane, an aqueous polyurethane dispersion obtained by previously dispersing a polyurethane formed from the above-mentioned polyol component and polyisocyanate component in an aqueous solvent can be used.

The porous elastic body 20 can be formed, for example, as follows. Although not particularly limited, as an example, a method of forming the porous elastomer in an aqueous solvent by using a pore-forming component and other additives (such as a surfactant) in addition to the polyol component and the polyisocyanate component by using a means of the water coagulation method will be described.

First, in addition to the polyol component and the polyisocyanate component, a pore-forming component, an aqueous solvent, and other additives are prepared.

As the pore-forming component, a pore-forming agent composed of a water-soluble inorganic salt may be used. Examples of such inorganic salts include sodium salts and potassium salts. More specifically, there may be mentioned: chlorides such as sodium chloride and Potassium chloride, sulfates such as sodium sulfate (mirabilite) and Potassium sulfate (Potassium sulfate), and the like.

By dissolving the pore-forming component in the polyurethane, voids are formed in the place where the pore-forming component is present. The pores of the porous elastomer originate from the voids. Since the size of the pores formed is affected by the particle size of the pore-forming agent and its variation, it is necessary to control the particle size of the pore-forming agent and its variation in order to obtain a porous elastomer in which the average value of the major axes of the pores is 60 μm or less and the standard deviation of the major axes of the pores is 60 μm or less. For example, the pore-forming component preferably contains at least a part of a pore-forming agent having an average particle diameter of 30 μm or less. In order to reduce the variation in the outer diameter of the pores formed, it is preferable to use a pore-forming component containing a pore-forming agent having a narrow particle size distribution.

On the other hand, when the pore diameter is reduced, the strength or elasticity of the sponge tends to be reduced. Therefore, it is preferable that a part of the porous elastomer contains pores having a large outer diameter. The thickness of the skeleton structure of the sponge surrounding the portion of the large outer diameter pores tends to be larger than the thickness of the skeleton structure surrounding the portion of the small outer diameter pores. Such a thick skeleton structure functions as a strut for supporting the internal structure of the sponge. This increases the strength and elasticity of the sponge, and makes it difficult for the sponge to lose its springback capability.

Therefore, the pore-forming component preferably contains both the first pore-forming agent having an average particle diameter of 30 μm or less and the second pore-forming agent having an average particle diameter of more than 30 μm. The ratio of the second pore-forming agent to the total amount of the pore-forming component can be appropriately selected in consideration of the required strength and elastic modulus. The content is, for example, 40 mass% or less, or 30 mass% or less, or 20 mass% or less, or 10 mass% or less of 100 mass% of the pore-forming component.

The amount of the pore-forming component is preferably in the range of 100 to 2000 parts by mass, more preferably in the range of 500 to 1500 parts by mass, relative to 100 parts by mass of the solid content of the polyurethane to be formed. If the amount of the pore-forming component is too small, the pore-forming agent makes the distribution of pores easily uneven without spreading throughout the entire polyurethane. In addition, if the amount of the pore-forming component is too large, the strength of the porous elastomer tends to be lowered. When the pore former is used in an amount of 100 parts by mass or more and 2000 parts by mass or less based on 100 parts by mass of the solid content of the polyurethane to be formed, the distribution of pores formed in the porous elastomer and the strength or elasticity of the porous elastomer are appropriate, and therefore, such is preferable.

Examples of the aqueous solvent include water and a mixture of water and a water-soluble solvent. Examples of the water-soluble solvent include alcohol solvents such as methanol, ethanol, and ethylene glycol. From the viewpoint of reducing the burden on the environment, the cost, and the like, it is preferable to use water alone as the aqueous solvent.

The amount of the aqueous solvent (preferably water) is preferably 10 parts by mass or more and 300 parts by mass or less, and more preferably 10 parts by mass or more and 200 parts by mass or less, with respect to 100 parts by mass of the solid content of the polyurethane to be formed. Within such a range, the viscosity of the polyurethane-containing solution is appropriate, and the obtained polyurethane has appropriate strength and elasticity, and the above range is preferable in these respects.

Examples of the other additives include surfactants such as sorbitan fatty acid esters, polyglycerin fatty acid esters, and polyethylene glycol oleates. The surfactant is preferably 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the solid content of the polyurethane to be formed, for example.

These raw materials are used to form a polyurethane cellular elastomer by the water coagulation method. First, the above components are added to a kneading apparatus and kneaded. Kneading may be carried out using a kneader, an auger mixer, a Banbury mixer, a screw extruder, or the like.

After the kneading, the obtained mixture was defoamed. After defoaming, the resulting product is molded into a desired shape. The method of defoaming is not particularly limited. For example, a vented extruder can be used to perform defoaming under reduced pressure. The method of molding is also not particularly limited. For example, a forming die (T-die) corresponding to a desired shape is connected to a vented extruder for defoaming under reduced pressure to perform forming.

After molding, the molded article obtained is put into water or an aqueous solution. By this operation, the solvent was replaced with water to precipitate the polyurethane. This operation is called water coagulation. The step up to the introduction of the molded body is not particularly limited, but a method may be employed, for example, a method in which a box shape with an open upper surface is formed using a punched metal plate made of stainless steel 304 or the like in the molding step, the kneaded material is extruded and filled into the box shape to mold the box shape, and the obtained molded body is introduced into water or an aqueous solution.

After the operation of water coagulation, the pore former composed of a water-soluble inorganic salt is dissolved in water and removed. The method is not particularly limited, but examples thereof include the following methods. The molded product of the kneaded product charged in the vessel was placed in hot water to dissolve most of the pore-forming agent. Then, the molded body is put into a general washing machine or the like and washed in water at about 20 to 80 ℃ for about 15 to 90 minutes. Further, it is preferable to replace the washing water as needed at the time of washing.

The molded body obtained in this way is dried. In order to prevent the polyurethane from being deteriorated by heat, the polyurethane is dried in a dryer at 110 ℃ or lower, for example. By doing so, a cosmetic sponge made of a polyurethane porous elastomer can be obtained.

[ sponge for beauty treatment ]

Next, the cosmetic sponge of the present application will be described. Referring to fig. 1 to 3, the cosmetic sponge 10 according to the present embodiment is composed of a porous polyurethane elastomer 20 having a plurality of pores. The cosmetic sponge 10 has a cross section 100 in which the average value of the major axes of pores is 60 μm or less and the standard deviation of the major axes of pores is 60 μm or less. The cosmetic sponge 10 according to the present embodiment can be produced, for example, by the above-described method. However, the production method is not particularly limited.

The pore analysis can be performed by cutting the cosmetic sponge 10, observing the cross section 100 with a Scanning Electron Microscope (SEM), and performing image analysis on the obtained SEM image. The image analysis may be performed by image processing or may be performed by visual observation. However, as described below, it is preferable to perform image analysis by image processing in order to reduce errors. In addition, the image processing may use appropriate image processing software or image processing applications.

An example of a method for analyzing the pores in the cross section 100 will be described with reference to fig. 2 to 5. Fig. 3 is a diagram of a processed image obtained by binarizing a part of a cross-sectional image of a cosmetic sponge. Fig. 4 and 5 are views for explaining the major axis and the minor axis of the air hole, respectively. The analysis of the pores is performed by taking an enlarged SEM photograph of a cross section 100 of the polyurethane elastomer and determining closed portions surrounded by the skeleton structure 30 of the sponge as pores 40 and 42.

In the image analysis, the number of pores contained in the cross section is counted. Binarization is performed based on the luminance value of the image to extract pores. The binarization of the luminance value may be performed in a state where two appropriate values are set in the automatic recognition by the image processing software, or may be performed in a state where the image of the object is determined from the luminance distribution histogram and the luminance range is directly set.

Next, measurement of the gas aperture is performed from the obtained binary image. The major axis of the air hole corresponds to the length of the long side of the circumscribed rectangle having the largest length of the long side, out of the circumscribed rectangles of the projected image of the air hole projected on the cross section 100. The short diameter of the air hole corresponds to the length of the short side of the circumscribed rectangle having the largest length of the long side (the length of the side in the direction perpendicular to the long diameter). Referring to fig. 4 and 5, for example, the major diameter LD of the air holes 40 and 42 is determined as the length of the long side of the circumscribed

rectangles

50 and 52 having the largest length of the long side among the circumscribed rectangles of the projected images of the air holes projected on the cross section 100. The short diameters SD of the air holes 40 and 42 are determined as the lengths of the short sides of the circumscribed rectangles 50 and 52 (the lengths in the direction orthogonal to the long diameters).

When the pore diameter is obtained from a binary image obtained from an SEM photograph, noise that is not actually related to the pores may be reflected on the cross section 100. Such noise may degrade the detection accuracy of the air aperture. Therefore, the noise removal processing can be performed by image processing as necessary.

The method of the noise removal processing is not particularly limited, but examples thereof include processing such as "hole filling" and "chipping removal". The "hole filling" is a process of recognizing a fine light-color region expressed in a dark-color region in a binary image as noise and replacing the noise with a dark color. The term "patch removal" refers to a process of recognizing, as noise, a fine dark color region having a predetermined size or less, which is expressed in a light color region, and replacing the fine dark color region with a light color region. By making the noise darker or lighter, it is possible to remove noise that is reflected regardless of the actual pores, and to analyze the state of pore formation more precisely.

Examples of actual image processing are shown in fig. 6 and 7. Fig. 6 and 7 are diagrams for explaining an example of image processing for removing noise, respectively. An example of a process of "hole filling" is shown in fig. 6. In fig. 6, in the binary image obtained by the SEM photograph, a light-colored region 60 having a light color tone is present in a part of the dark-colored region representing the air hole 40. Such a light color region 60 is noise that causes an error and hinders accurate analysis, and therefore it is necessary to perform noise removal processing. Therefore, the light-colored region 60 having a predetermined size or less (for example, 100 pixels or less) existing in the dark-colored region is regarded as noise and is changed to a dark color. The size of the

pores

40 and 42 of the cosmetic sponge 10 of the present application is larger than such noise to a clearly distinguishable level. Therefore, even if such noise removal processing is performed, the leak hole is less likely to be erroneously detected. By such noise removal processing, the pores can be analyzed more accurately.

Fig. 7 shows an example of the "chipping removal" process. In fig. 7, in the binary image obtained based on the SEM photograph, a dark color region 70 having a darker color tone is present in a part of the light color region. Such a dark color region 70 is noise that causes an error and hinders accurate analysis, and therefore it is necessary to perform noise removal processing. Therefore, the dark color region 70 having a predetermined size or less (for example, 100 pixels or less) existing in the light color region is regarded as noise and is changed to light color. The size of the

pores

By performing such image processing, errors caused by reflection of portions other than pores can be substantially reduced. Therefore, as the preprocessing before the pore diameter is obtained from the binary image, it is preferable to perform the noise removal processing. After the above processing (or without performing the processing if unnecessary), the statistical data of the pores can be obtained by performing automatic measurement.

In the above description, the predetermined size is set to 100 pixels or less, but the size may be changed as appropriate as long as the size is a size that can sufficiently remove noise. For example, the number of pixels can be adjusted to 200 pixels or less, 50 pixels or less, or the like as appropriate.

In the cosmetic sponge according to the present embodiment, the average value of the major axes of pores in the cross section of the porous elastic body constituting the cosmetic sponge is 60 μm or less. The standard deviation of the major axes of the pores is 60 μm or less. As described above, the cosmetic sponge according to the present embodiment has extremely fine pores and small variations in pore size. As described above, the average value and the standard deviation of the major axes of the pores can be obtained from the binary image obtained based on the SEM photograph according to the procedure described above.

In addition, in the cross section of the cosmetic sponge, the average value of the short diameters of the pores is preferably 20 μm or more and 35 μm or less, and the standard deviation of the short diameters of the pores is preferably 15 μm or more and 40 μm or less. By having such a short diameter, a sufficient volume can be secured in the cavity for containing the liquid. The average value of the minor axis and the average value of the major axis of the pore can also be obtained by the above-described procedure from the binary image obtained from the SEM photograph.

In addition, in the cross section of the cosmetic sponge, the maximum value of the minor axis of the pores is preferably 120 μm or more. As described above, when the pores of the sponge are made thin, the skeleton structure of the sponge surrounding the pores tends to be thin and soft, and the strength and elastic force of the sponge tend to be reduced. In order to maintain the strength and elasticity of the sponge at a constant level, it is preferable that a part of the sponge has a thick skeleton portion.

A sponge having an average value of the major axes of pores of 60 μm or less and a maximum value of the minor axes of pores of 120 μm or more has an internal structure mainly including pores having a small outer diameter and including pores having a large outer diameter in part. By partially including pores having a large outer diameter in a part of the internal structure of the sponge, the strength and elasticity of the sponge are improved. This is because the thickness of the skeleton structure of the sponge surrounding the portion of the air holes having a large outer diameter is made larger than the thickness of the skeleton structure surrounding the portion of the air holes having a small outer diameter. That is, the skeleton structure of the sponge surrounding the portion of the air hole having a large outer diameter functions as a support column supporting the internal structure of the sponge, and thus the strength and elasticity of the sponge are increased, and the sponge is less likely to lose its resilience. For this reason, the cosmetic sponge preferably has a maximum value of the minor axis of the pores in the cross section of 120 μm or more.

The number of pores in the cross section is preferably 200 or more pores in the range of 10mm × 10mm in the cross section of the cosmetic sponge, for example. When 200 or more pores are present in the range of 10mm × 10mm in the cross section of the cosmetic sponge, pores having a small volume are densely arranged in the cosmetic sponge. Namely, the cosmetic sponge has very fine pores. Such a cosmetic sponge having a small hole is particularly suitable as a sponge for applying a foundation, because it can transfer a foundation uniformly to the skin, and can make a makeup with a small amount of makeup spots and a good finish.

The outer diameter and distribution of the pores of the porous elastomer can be controlled by adjusting the ratio of the polyol component and the polyurethane component constituting the polyurethane, the condition or the kneading time at the kneading, the kind or the amount of the additive, the amount or the particle diameter of the pore-forming agent, the particle size distribution, and the like. In particular, the ease of pore formation also varies depending on the kind of the polyurethane component. Therefore, various conditions can be appropriately adjusted according to the characteristics of the polyurethane component, the desired characteristics, and the like. In addition, the state of pore formation is also changed by adjusting the kind or amount of the surfactant.

The hardness of the cosmetic sponge is preferably 50 degrees or more and 70 degrees or less in ASKERFP hardness at 25 ℃. The cosmetic sponge having such hardness has appropriate elasticity and strength, and is good in touch with the skin. The hardness can be freely controlled by adjusting the selection of the compounding ratio of the combination of the polyol component and the polyisocyanate compound, the porosity of the porous elastomer, and the like. ASKER FP hardness can be measured using an ASKER rubber durometer type FP.

[ use ]

The cosmetic sponge according to the present embodiment is suitable for cosmetic applications such as cosmetics and beauty because it has fine pores, good touch feeling, and is mild to the skin. The cosmetic sponge is particularly suitable as an application sponge for applying a foundation. By using the cosmetic sponge according to the present embodiment, a foundation can be spread evenly on the skin while being thin, and a natural finish can be achieved.

In addition, the sponge can be suitably used as a sponge for cleansing in cosmetic applications. The cosmetic sponge according to the present embodiment is particularly suitable for use as a cleansing sponge which is mild to the skin and is easy to clean dirt.

Examples

The present invention will be described more specifically with reference to examples. The scope of the present invention is not to be construed as being limited by the description of the examples.

[ preparation of sponge for beauty treatment ]

Cosmetic sponges of examples and comparative examples were obtained by the method described in the above embodiment (water coagulation method). The following components were used as raw materials.

(polyurethane component (solution))

Polyurethane A: polyester polyurethane (molecular weight 10-20 ten thousand, molecular weight distribution mode about 15 ten thousand), solid content 30% (solvent: Dimethylformamide (DMF))

Polyurethane B: polyether polyurethane (molecular weight 10-20 ten thousand, molecular weight distribution mode about 15 ten thousand), solid content 30% (solvent: dimethyl formamide (DMF))

(pore-forming agent)

Anhydrous sodium sulfate for comparison: neutral anhydrous sodium sulfate

Anhydrous sodium sulfate a: neutral anhydrous sodium sulfate

Anhydrous sodium sulfate E: neutral anhydrous sodium sulfate (silica treatment product)

(solvent)

Dimethylformamide (DMF)

(surfactant)

Sorbitan sesquioleate (HLB value 3.7)

Wet-type silicon dioxide

(viscosity modifier)

Nonionic cellulose ethers

(pigment)

Carbon black

(moisture adjuster)

Dimethylformamide (DMF)2.8 parts by mass and water (filtered water)

Table 1 shows the measured values of the particle diameters of the comparative thenardite, thenardite a, and thenardite E used as the pore-forming agent. The particle size was measured using a laser diffraction particle size distribution measuring apparatus (SALD-2200, manufactured by Shimadzu corporation). The results are shown in table 1. The 5%, 50%, and 75% particle diameters refer to particle diameters at which points in the particle size distribution of mirabilite where the cumulative curve is determined with the total volume of the powder aggregate as 100%, and the cumulative curve is 25%, 50%, and 75%, respectively, as 25%, 50%, and 75% (μm). The median particle diameter has the same meaning as 50% particle diameter. The mode particle diameter refers to a value of a mode in a particle diameter distribution of mirabilite.

[ Table 1]

The unit of numerical value in the left color table is mu m

Examples 1 to 4 and comparative example 1

Raw materials were prepared according to the components shown in the compounding table of table 2 below, and made into a cosmetic sponge. In examples 1 to 4, mixtures of thenardite a and thenardite E having different mixing ratios were used. In comparative example 1, a mixture of mirabilite for comparison and thenardite a was used. In table 2, the numerical units indicate "parts by mass".

The cosmetic sponge was produced as follows. First, the above-mentioned raw materials were charged into a 30-liter kneader having an internal temperature of 40 ℃. After the charging, the mixture was kneaded at a rotation speed of 15rpm for 30 minutes. The resulting mixture was extruded at a set temperature of 40 ℃ through a vented extruder equipped with a T die having an inner diameter of 300X 20mm while defoaming under reduced pressure. The extruded molded article was filled in a box-shaped container made of SUS304 punched metal plate and having an inner size of 300 mm in width, 600 mm in length, and 30mm in height and an open upper surface. After filling, the mixture was immersed in water at 50 ℃ for 24 hours, and dimethylformamide was replaced with water, thereby solidifying the water. After completion of solidification, the pore-forming agent is dissolved and removed to remove the molded article from the box-shaped container. The molded product was put into a household washing machine and washed with water at 50 ℃. Thereafter, the mixture was dried in a dryer at 100 ℃ for 8 hours. The obtained sponge was cut off at the upper and lower portions with a slicer (band machine) to obtain a cosmetic sponge having a predetermined thickness (about 1.5 mm).

[ Table 2]

The numerical value in the corresponding table is in parts by mass

[ evaluation of cosmetic sponge ]

Next, cosmetic sponges were evaluated based on the following evaluation items. The evaluation items and the evaluation procedures thereof are shown below.

[ Cross-sectional view ]

A part of the sponge obtained as described above was cut in the thickness direction to expose the cross section. The cross section was observed using a Scanning Electron Microscope (SEM) (3D real-time surface observation microscope VE-8800, manufactured by KINYZ Co., Ltd.). Fig. 8 to 12 show photographs of cross sections of cosmetic sponges obtained in comparative example 1 and examples 1 to 4. FIG. 8 is a photograph showing a cross section of the cosmetic sponge obtained in comparative example 1. FIGS. 9 to 12 are sectional photographs of cosmetic sponges obtained in examples 1 to 4, respectively.

[ hardness ]

The hardness of the cosmetic sponge was measured using an ASKER durometer FP type manufactured by polymer instruments. The results are shown in table 3. The unit of hardness in the table is "degree (point)" (also referred to as "°").

[ Table 3]

[ analysis of pores ]

The formation state of the pores was analyzed by performing image analysis processing on a cross-sectional image obtained by taking a cross-sectional photograph of the cosmetic sponge by SEM, which was obtained in the item of "cross-sectional observation". The area and the perimeter of the pores, the Feret (Feret) diameter, the maximum value, the minimum value, the average value, the standard deviation of the major diameter and the minor diameter of the pores, and the number of pores within the range of 10mm × 10mm were obtained by image analysis. Regarding the number of air holes, the number actually measured in the imaging range was converted into the number per unit area of 10mm × 10 mm. The results of the analysis of the pores are shown in table 4.

[ Table 4]

[ evaluation test of cosmetic Properties ]

The makeup sponges of comparative example 1 and example 3 were used to evaluate the makeup properties by actually transferring a foundation onto a base. The evaluation of the cosmetic properties was performed as follows.

Sponges of comparative example 1 and example 3, which were prepared in the above-described manner so as to have a thickness of 1.5mm, were prepared as samples. As a foundation for evaluation, a foundation having a viscosity of 3000mPa · s was prepared.

(1) Comparing the makeup completion degree of the beating on the skin of the human body

The foundation was pressed 1 time against the sponge of the sample and transferred to the skin, and the adhesion state of the foundation to the surface of the sponge and the transfer state when transferred to the skin were evaluated.

In the case of the sponge of comparative example 1, although the amount of the foundation attached to the surface of the sponge was as small as possible, a large amount of cosmetic spots transferred to the skin were observed.

In contrast, in the case of the sponge of example 3, the amount of the foundation attached to the surface of the sponge was relatively large. In addition, when the transfer is directly performed on the skin, a large amount of the transfer is performed on the skin. In addition, although a large amount of the toner is transferred to the skin, the toner is transferred uniformly. The makeup was good and no cosmetic spots were observed.

In contrast, in the case of the examples, the skin was sufficiently and uniformly coated on the surface of the skin to conceal the skin.

(2) Flap test on synthetic leather

Transfer of the foundation to the synthetic leather was performed by the following method, and the adhesion state of the foundation to the sponge surface and the transfer state at the time of transfer to the synthetic leather were evaluated.

First, 0.01g of foundation was placed on a PET (polyethylene terephthalate) film so that the diameter thereof became 6 mm. The sponge was placed on a PET film so as to cover the foundation, and the sponge was allowed to absorb the foundation by pressing a load of 700gf (6.86N) for 1 second or less on the surface of the sponge on the side not in contact with the foundation and repeating the operation 10 times. The adhesion state of the foundation on the surface of the sponge was evaluated by visual observation.

Next, the sponge was placed on the surface of the synthetic leather so as to contact the surface to which the foundation was applied, and the surface of the sponge on the side not in contact with the synthetic leather was subjected to an operation of pressing a load of 700gf (6.86N) for 1 second or less, and the operation was repeated 10 times, thereby transferring the foundation to the surface of the synthetic leather. The adhesion state of the foundation on the surface of the synthetic leather was evaluated by visual observation. In addition, an enlarged SEM photograph of the surface of the synthetic leather was taken. Fig. 13 is an enlarged photograph showing a transfer state of the foundation on the surface of the synthetic leather when the foundation is applied using the sponge of comparative example 1. On the other hand, an enlarged photograph of the transfer state of the foundation in the case where the foundation was applied using the sponge of example 3 is shown in fig. 14.

The adhesion state of the foundation on the surface of the sponge was evaluated by visual observation, and as a result, the foundation adhered to the surface of the sponge of the example was finer in particles and more uniformly adhered as compared with the comparative example.

Further, as is clear from the photographs of fig. 13 and 14, the transfer state of the synthetic leather surface was compared, and as a result, a significant difference was clearly found in the transfer state of the foundation. First, it was found that the powder foundation on the surface (fig. 13) of the synthetic leather to which the powder foundation was transferred using the sponge of comparative example 1 had coarse particles, and the difference in color tone between the transferred portion and the non-transferred portion was considerably large. On the other hand, on the surface of the synthetic leather (fig. 14) to which the foundation was transferred using the sponge of example 3, the particles were fine and uniformly transferred, although the transfer amount of the foundation was relatively large. A so-called thin-coated state is formed.

In this way, when the cosmetic sponge according to the present invention, that is, the sponge of the example was used, it was found that the transfer amount of the foundation was sufficient, and the transferred foundation had fine particles and was uniformly transferred. The sponge is suitable for realizing makeup with less makeup spots and good makeup finish.

(conclusion)

From the above results, it is understood that the cosmetic sponge according to the present invention is a sponge having fine pores and high uniformity, and is suitable for cosmetic applications. Such a sponge is excellent in feeling of use and can be suitably used as a cosmetic sponge having a fine mesh suitable for makeup and makeup removal.

All the contents of the embodiments and examples disclosed herein are illustrative and should not be construed as being limited in any way. The scope of the present invention is defined not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

Industrial applicability of the invention

The cosmetic sponge of the present invention can be advantageously used in the fields of cosmetics such as cosmetic use and cosmetic use.

Description of reference numerals:

10: a cosmetic sponge; 20: a porous elastomer; 30: constructing a framework; 40. 42: air holes; 50. 52: a circumscribed rectangle; 60: a light color region; 70: a dark color region; 100: and (4) section.

Claims

1. A cosmetic sponge comprising a porous elastomer made of polyurethane having a plurality of pores, wherein the average value of the major axes of the pores is 60 [ mu ] m or less and the standard deviation of the major axes of the pores is 60 [ mu ] m or less in the cross section of the cosmetic sponge.

2. The cosmetic sponge according to claim 1, wherein the maximum value of the minor axis of the pores in the cross section is 120 μm or more.

3. The cosmetic sponge according to claim 1 or 2, wherein 200 or more pores are provided in a range of 10mm x 10mm in the cross section.

4. The cosmetic sponge according to any one of claims 1 to 3, wherein, in the cross section, an average value of short diameters of the pores is 20 μm or more and 35 μm or less, and a standard deviation of the short diameters of the pores is 15 μm or more and 40 μm or less.

5. The cosmetic sponge according to any one of claims 1 to 4, wherein the ASKER FP hardness at 25 ℃ is 50 degrees or more and 70 degrees or less.

6. The cosmetic sponge according to any one of claims 1 to 5, wherein the cosmetic sponge is used for makeup.

7. The cosmetic sponge according to any one of claims 1 to 5, wherein the cosmetic sponge is used for beauty.