JP5825654B2 - Method for measuring UV protection effect of cosmetics, measuring device, and method for displaying measured values - Google Patents

Description

The present invention relates to a method for measuring the UV protection effect of cosmetics by an in vitro method, a measuring apparatus, and a method for displaying measured values.
More specifically, in the in vitro method for measuring the UV protection effect using a measuring device without using a human as an experimental body, the UV protection effect measurement method for obtaining a more accurate measurement value, and the measurement method. The present invention relates to a measuring device and a display method of measured values measured based on the measuring method.

Currently, in Japan, as an index of UV protection effect in cosmetics, SPF (abbreviation of Sun Protection Factor) indicating the protection ability of B-wave ultraviolet light with a wavelength of 290 to 320 nm, and protection ability of A-wave ultraviolet light with a wavelength of 320 to 400 nm are shown. PA (Protection grade of UVA) is used. When displaying these measurement results on cosmetics, display the value measured based on each measurement method standard (Non-patent Document 1) (Non-patent Document 2) established by the Japan Cosmetic Industry Association or its grade. Is required.
Even overseas, it is basically required to display according to the measurement method and display method (Non-Patent Document 3) of each region, but the basic measurement method is almost unified. In the measurement method standard, a human back is used, and the back is irradiated with high-power ultraviolet rays, and the ultraviolet protective effect is measured from the result of visual observation of the inflammatory reaction and the blackening reaction occurring in the skin. However, when a human is used, it takes time and money, and the period until the measurement result is obtained is long.
In addition, there are ethical and medical problems associated with the use of humans. In Japan and Europe, in vitro measurement methods that measure UV protection effects with machines without using humans are underway. (Non-Patent Document 4). However, it has been reported that there are many problems even with the in vitro measurement methods currently being promoted (Non-patent Document 5). The inventors have also found that the SPF value fluctuates up to 20 times even when the same sample is used and tested in the same standard.

There are a number of clear reasons for this problem that can be explained scientifically. Understanding this reason and testing under control will solve the problem. However, it is considered that the current situation is not solved. The present inventor has advanced technology in this scientific field, and has examined whether control is possible accurately, accuracy of control, reproducibility, and the like.
As a result, there is a sample preparation method, that is, how smoothly a thin film of several μm to several tens of μm is applied with an accuracy of about 1 μm, and the coating amount per unit area is not determined at the time of coating The point was found to be the key to solving the problem.
In the case where the sample is abundant and a large smooth coating film of how many square meters is formed, there is a method using a large apparatus as described in (Non-patent Document 6) or (Patent Document 1), such as application of liquid crystal on a display. But it is also used.
However, in the case of cosmetics, the amount of sample is small and the required coating area is at most several tens of cm ² . Therefore, in order to develop a measurement method suitable for cosmetics, it is necessary to grasp scientific phenomena. Further, even in a spin coater that is said to form a smooth coating film in the field of resist coating and the like, when actually examined, there is a fine streak structure on the coating film surface as described in (Patent Document 2). Therefore, a smooth surface cannot be formed. Even in a wire coater used to form a smooth coating film with a paint, when actually tested, it is divided into cosmetics that can form a smooth coating film and cosmetics that cannot. (Non-Patent Document 7) Originally, paint and resist technologies have the meaning of smoothness when a variation of several tens of μm is allowed, and the required accuracy is compared with the measurement method of UV protection effect in cosmetics. Are very different. For this reason, it is not easy to thin out cosmetics with various properties in this way, even if we collect existing materials that have been written to be able to be applied smoothly and test them. I understand. As described in Non-Patent Document 3, this is the reason why the in vitro measurement method has not been successful even though 13 years have passed since the first development and various improvements have been made all over the world. It is one of.

Here is one of the key papers to solve this problem. (Non-Patent Document 8) shows that a stripe pattern is formed on the surface of a coating film by directional viscous fingering, which is a non-equilibrium self-organization phenomenon. It is shown that it is controlled by the construction speed and the gap size of the applicator.
This stripe pattern is also formed at the time of sample preparation in the in vitro measurement method currently being studied by the cosmetic industry association in Japan and Europe, but when the stripe pattern is formed, the stripe valley is thin. Therefore, since the irradiated ultraviolet rays are more transmitted from the valley portions, the value of the ultraviolet ray protection effect varies greatly depending on the presence / absence, shape, and depth of the stripes.
In particular, the present inventors have found that cosmetics having a high UV protection effect are more strongly affected. Therefore, it is important not to form a stripe pattern by controlling the coating speed. Details of the degree of this effect will be described later.

The next problem is lift. In the in vitro measurement method currently under study, a sample is applied to the measurement plate with a human finger. If the sample has a cylindrical shape like a finger, lift is applied to the finger, and the film thickness of the coating is constant. Don't be. In application with a finger, it is extremely difficult for a person to keep the force with which a finger presses a sample against a measurement plate. Therefore, a coating film becomes non-smooth and becomes a big factor that a measured value is not stabilized.
Lift is influenced not only by the shape of the object to be applied, such as fingers, but also by the viscosity, thixotropic properties, and application speed of the cosmetic to be measured. In order to increase the measurement accuracy by the in vitro measurement method, it is essential to form a smooth coating film having a certain area. The technology of (Non-patent Document 8) uses a cylindrical applicator, so there is a problem of lack of accuracy in a slightly large area. In order to perform smooth coating in an area of 25 cm ² or more, the shape of the applicator It is necessary to consider about. Details of the shape will be described later.

  The method of coating is also a problem. Usually, in the application of ink or the like, a method is used in which a liquid to be applied is placed on the front surface of the applicator in the traveling direction, and the liquid is stretched. If there is a thick liquid film in front of the applicator in the direction of travel, the applicator rides on it, and even if there is no problem with the accuracy required for ink and paint, it will be a big problem in in vitro measurement of UV protection effect of cosmetics. A change in level film thickness occurs. Therefore, how to place the sample is also an important factor. However, even if the sample placement is devised, if the viscosity of the sample is high, the film thickness tends to increase by about 2 cm from the start of coating, so it is necessary to exclude this part.

  The accuracy of the applicator also greatly affects the smoothness of the coating. If the applicator has poor accuracy, a smooth coating film cannot be obtained, so the applicator needs a certain dimensional accuracy. (Patent Document 3) Although the speed control is not performed in paragraphs 0067 to 0071, a coating method using a non-cylindrical applicator is shown. The thickness varies greatly. Although specific numerical values will be described later, a smooth coating film cannot be formed if the accuracy of the applicator is poor.

Considering these factors, it is assumed that a smooth coating film can be formed. In the in vitro measurement method currently being studied, the target coating amount per unit area is set to 0.75 mg / cm ² from the beginning, but this is different in properties such as viscosity. Realization in various cosmetics is a very time-consuming problem. In particular, when a target is applied, even if a deviation of only 0.1 mg occurs, the fluctuation range is 0.1 / 0.75 = 0.13, which is 10% or more, and the required coating accuracy is an order of magnitude smaller. Although it is necessary to aim, the coating characteristics of the cosmetics to be measured are different for each cosmetic and lot, and it is extremely difficult to examine the measurement conditions each time.
On the other hand, the method of the present inventors does not set a target value for the coating amount per unit area. Instead, the coating amount or film thickness per unit area is measured, and the UV protection effect at the target coating amount per unit area is calculated for calculation. More specifically, from the absorbance curve or transmittance curve of the smooth film and the value of the coating amount per unit area, a method for obtaining the UV protection effect at the target coating amount per unit area is calculated. Yes. Therefore, there is no need to set the target coating amount from the beginning, and it is a major feature that not only simpler coating is possible but also accuracy during coating is ensured. . A specific measurement method will be described later.

  Furthermore, at present, powder cosmetics may be measured in combination with a solvent that does not have ultraviolet absorbing ability in the in vivo method. However, when a coating film is created using an ultraviolet ray transmissive component, ultraviolet rays are transmitted through the component, indicating performance far from the actual state (usually, the performance is displayed lower than the actual state). There is a problem. Therefore, as a method for stably measuring the UV protection effect of powder cosmetics, a volatile solvent having a specific boiling point or higher is mixed with the powder cosmetics at a specific ratio, and this material is applied smoothly. By measuring the UV protection effect after drying, the UV protection effect of the powder cosmetic can be measured stably and with good reproducibility.

  In addition to the method of the present inventor, examples of methods conventionally used as in vitro measurement methods in the cosmetic industry are introduced below. In paragraph 0146 of (Patent Document 4), a measurement method using a quartz plate is shown. Specifically, it is a method in which a certain area is marked on a quartz plate, and a certain amount of sample is applied to the quartz plate with a finger. Usually, this method is often used in the cosmetic industry. On page 10 of (Patent Document 5), a method of applying a sample to the horny skin of a guinea pig with a finger is shown, but animal skin originally has low smoothness. In paragraph 0026 of (Patent Document 6), a method of applying a sample to VITRO-SKIN is shown. This method has a problem that smooth coating cannot be performed because VITRO-SKIN itself has low smoothness.

JP 2006-26596 A JP 2008-62182 A JP 2009-35551 A JP 2002-80748 A JP-A-6-16527 JP 2009-299059 A

Japan Cosmetic Industry Association UV Protection Cosmetics and UV Protection Effect-SPF and PA Label-2003 Revised Edition Japan Cosmetic Industry Association Japan Cosmetic Industry Association SPF Measurement Method Standard (Revised 2007) ISO / TR26369 Cosmetics-Sun protection test methods-Review and evaluation of methods to assess the photoprotection of sun protection products Colipa Guidelines, Method for in vitro Determination of UVA protection, 2009 Rohr, M .; Klette, E .; Ruppert, S .; Bimzcok, R .; Klebon, B .; Heinrich, U .; Tronnier, H .; Johncock, W .; Peters, S .; Pfluecker, F .; Rudolph, T .; Floesser-Mueller, H .; Jenni, K .; Kockott, D .; Lademann, J .; Herzog, B .; Bielfeldt, S .; Mendrok-Edinger, C .; Hanay, C .; Zastrow , L. “In vitro Sun Protection Factor: Still a Challenge with No Final Answer” Skin Pharmacol. Phys. 2010, 23 (4), 201-212. http://www.yasuiseiki.co.jp/coting1.html (searched August 16, 2010) Kenon Onishi Research on Paints No.145 Mar. 2006 http://www.kansai.co.jp/rd/token/pdf/145/10.pdf (searched on August 19, 2010) Kuroda, A .; Ishihara, T .; Takeshige, H .; Asakura, K. "Fabrication of Spatially Periodic Double Roughness Structures by Directional Viscous Fingering and Spinodal Dewetting for Water-Repellent Surfaces", J. Phys. Chem. B, 2008 , 112 (4), 1163 -1169.

As described in (Non-patent Document 3) above, in vitro method development has been proposed around 1997, and has already been studied all over the world for 13 years. Regardless, no method for obtaining a stable measurement value was proposed, and stable measurement could not be performed.
That is, in the conventional method, a human forms a non-smooth film using a finger and measures it. In Japan and Europe, an evaluation method based on a measuring instrument and a measurement substrate is considered, but the method is forced to introduce a new device.
As described in (Non-Patent Document 5), it can be seen that the measurement value obtained by the conventional measurement method has a considerably low accuracy of the measurement value obtained.
Although the SPF value of 10 different is perceived by consumers as a difference in performance, the SPF values of 50 and 35 may be obtained as a measurement result even with the same sample in the conventional measurement method, which is more accurate. It was desired to obtain measurement results.
In addition, measurement of powder cosmetics has been quite difficult, and not only the reproducibility of measured values, but also the large gap between manufacturers, has proved difficult and has not been discussed much.

1. It is a method for measuring the ultraviolet protective effect of a liquid cosmetic comprising the following steps a) to d).
a) A step of applying and forming a smooth liquid cosmetic layer on a substrate by moving a spreading member having an angle of 30 ° or more with the substrate on the substrate at a constant speed.
b) A step of measuring a coating amount per part of the substrate and a unit area or a thickness of the layer in a state where the formed layer is not dried.
c) A step of measuring the ultraviolet protective effect of another liquid cosmetic layer obtained by the step a).
d) A step of calculating the ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the above b) step and c) step.

2. It is a method for measuring the ultraviolet protective effect of a powder cosmetic comprising the following steps e) to i).
e) A step of obtaining as a sample a composition comprising a powder cosmetic and a volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure in a mass ratio of 100: 100 to 100: 50. .
f) A step of applying and forming a smooth liquid cosmetic layer on the substrate by moving the spreading member having an angle of 30 ° or more with the substrate on the substrate at a constant speed.
g) A step of measuring a coating amount per part of the substrate and a unit area or a thickness of the layer in a state where the formed layer is not dried.
h) A step of drying the other composition layer obtained in the step f) and measuring the ultraviolet protective effect of the composition layer after the drying.
i) A step of calculating an ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the step g) and the step h).

3. 3. The method according to 2, wherein the volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure is selected from cyclic hexamer dimethylpolysiloxane and caprylyl methicone.

4). 3. The method according to 1 or 2, wherein the constant speed is a speed in the range of 1 to 10 mm per second.

5. 5. Method according to 4, characterized in that the constant speed is in the range of 1-5 mm per second.

6). 3. The method according to 1 or 2, wherein the height of the gap between the tip of the spreading member and the substrate is in the range of 20 to 25 μm.

7). 3. The method according to 1 or 2, wherein the substrate is selected from materials having a smooth surface and a property of transmitting ultraviolet rays in the range of 290 to 400 nm.

8). 8. The method according to 7, wherein the substrate is selected from a quartz plate or a polymethyl methacrylate plate.

9. 3. The method according to 1 or 2, wherein when the sample is applied to the substrate, the sample is thinly spread on the substrate in advance and then subjected to a procedure of smooth coating with a spreader. Method.

10. 3. The method according to 1 or 2, wherein the part for measuring the coating amount or the film thickness is 15 mm or more away from the coating start position of the sample.

11. 11. The method according to 10, wherein the part for measuring the coating amount or the film thickness is at least 20 mm away from the coating start position of the sample.

12 2. The method according to 1, wherein the method for calculating the coating amount per unit area of the liquid cosmetic applied smoothly is according to the following method.
A) A resin film is prepared in which the volatile component used in the liquid cosmetic is impermeable or hardly permeable.
B) The mass of the resin film is measured, and the area of the resin film is obtained.
C) The mass of the substrate on which the layer made of the liquid cosmetic is formed is determined.
D) Before the formed smooth liquid cosmetic layer is dried, the resin film is allowed to stand on a part of the surface of the liquid cosmetic layer.
E) The liquid cosmetic layer in a portion not covered with the resin film is removed.
F) The mass of the sample comprising the resin film, the liquid cosmetic layer, and the substrate is measured.
G) The mass of the cosmetic material per unit area is measured from the above measured value.

13. 3. The method according to 2, wherein the method for calculating the coating amount per unit area of the powder cosmetic material applied smoothly is according to the following method.
A) A resin film in which a volatile solvent having a boiling point of 240 ° C. or higher mixed with the powder cosmetic is impermeable is prepared.
B) The mass of the resin film is measured, and the area of the resin film is obtained.
C) The mass of the substrate on which the layer composed of the composition is formed is determined.
D) Before the formed smooth composition layer is dried, the resin film is allowed to stand on a part of the surface of the composition layer.
E) The composition layer in a portion not covered with the resin film is removed.
F) The mass of the sample consisting of the resin film, the composition layer and the substrate is measured.
G) From the above measured value, the mass of the composition layer per unit area is measured.
H) The mass of the powder cosmetic in the composition layer is determined in consideration of the content of the powder cosmetic in the composition.

14. A method for obtaining a coating amount per unit area necessary for obtaining a target ultraviolet ray protection effect based on the ultraviolet ray protection effect in an application amount per unit area described in 14.1 or 2.
15. An apparatus for performing the method according to 1 or 2, comprising each apparatus for performing each of the above steps, including a part or all of the steps for measuring the ultraviolet protection effect, wherein the ultraviolet protection effect is obtained. A device that automatically measures.

16. A method according to 1 or 2 or a method of indicating on a container an indication indicating the method.

Conventionally, in vitro measurement methods based on the premise of finger coating that have been studied internationally have been aimed at an average standard deviation / measured value of 0.2, but have not been realized. On the other hand, in this method, the average of standard deviation / measured value is aimed at 0.1 or less for both SPF value and UVA-PF value, and reproducibility and accuracy are much higher. In the present invention, even in a single measured value, high accuracy was realized by striving to make each standard deviation / average of measurement 0.1 or less.
The apparatus according to the present invention is an apparatus having a simple structure, and although the method using the apparatus is also a simple method, the obtained SPF measurement value is stable and highly accurate as described above. The SPF measurement value that matches the consumer's sense can be shown. Moreover, it becomes possible to improve the reliability of the display object which displayed the result measured using this method.
In addition, this method provides a display method that allows direct comparison of similar products regardless of company, and makes the product selection criteria clear for consumers.

Example of graph showing the relationship between the coating amount per unit area of liquid cosmetics, SPF value, and UVA-PF value Example of graph showing the relationship between the coating amount per unit area of powder cosmetics, SPF value, and UVA-PF value Optical microscope image showing an example of a stripe pattern Optical microscope image showing stripe pattern formed on Colipa method uneven substrate Perspective view of spreading device Bottom view of spreader Cross section of spread member Cross section of spread member Conceptual view of the top surface after applying cosmetics on the substrate Conceptual diagram of the cross section after applying cosmetics on the substrate Conceptual diagram of the measurement method of the present invention

Hereinafter, the present invention will be described in detail.
The method for measuring the ultraviolet protective effect of the cosmetic of the present invention can be a method for measuring the ultraviolet protective effect of the liquid cosmetic, which has the following steps a) to d) for the liquid cosmetic. .
a) Applying and forming a smooth liquid cosmetic layer on the substrate by moving the spreading device on the substrate at a constant speed so that the angle between the spreading member and the substrate is 30 ° or more. Process.
b) A step of measuring a coating amount per unit area of the substrate and a thickness of the layer or a thickness of the layer in a state where the formed layer is not dried.
c) A step of measuring the UV protection effect of another liquid cosmetic layer obtained by the above step a)
d) A step of calculating the ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the above b) step and c) step.

For powder cosmetics,
The method to measure the ultraviolet-ray protective effect of powder cosmetics which has the process of following e)-i).
e) A step of mixing the powder cosmetic and a volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure in a mass ratio of 100: 100 to 100: 50.
f) Applying and forming a smooth liquid cosmetic layer on the substrate by moving the spreading device on the substrate at a constant speed so that the angle between the spread member and the substrate is 30 ° or more. Process.
g) A step of measuring a coating amount per part of the substrate and a unit area or a thickness of the layer in a state where the formed layer is not dried.
h) A step of measuring the ultraviolet protective effect of another liquid cosmetic layer obtained by the above step f).
i) A step of calculating an ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the step g) and the step h).

The UV protection effect referred to in the present invention is generally expressed as an SPF value corresponding to a B-wave ultraviolet ray having a wavelength of 290 to 320 nm, a UVA-PF value corresponding to an A-wave ultraviolet ray having a wavelength of 320 to 400 nm, or a PA classification or a PPD value. However, there is no particular limitation as long as it is an index indicating the protective effect of these wavelengths.
Steps b) and g) are largely different from the conventional method of coating by setting a target value of the coating amount per unit area, and the coating per unit area of the coated film itself is smooth. The purpose is to measure the work amount or the film thickness. The steps b) and g) are also very different from the conventional method of measuring the coated amount by setting the target value of the coating amount per unit area, and the UV protective effect of the coated film itself is smooth. Is intended to measure. Then, in the process of c) and h), for the first time, from the data obtained in the processes of b) c), g) h), the UV protection effect of the target coating amount or film thickness per unit area is predicted. Yes.

The coating and spreading apparatus of the present invention will be described below.
FIG. 5 shows a perspective view of the paint spreading device 1 used in the present invention.
The spreading device 1 is a device having a spreading member 2 and a support portion 3 for supporting both ends of the spreading member 2.
The spreading member 2 has a structure (not shown) with respect to the support portion 3, for example, pins provided at both ends of the spreading member are fitted into vertically extending grooves provided in the support portion 3. Thus, the cosmetics are supported so as to be freely movable up and down, and the cosmetics are uniformly applied to the substrate against the lifting force received from the cosmetics to be spread by the own weight of the spreading members. It is made like this.
Although the other members are not illustrated for the sake of explanation, the paint spreading device 1 shown in FIG. 5 is, for example, a member angle for connecting the two support portions 3 to be integrated as a paint spreading device. It is also possible to provide.
FIG. 6 is a view of the spreading device 1 as seen from the lower surface, and the spreading member tip 6 is located at the tip of the spreading member 2.

The material of the spreading member 2 and the support portion 3 provided in the spreading device 1 used in the present invention is preferably a metal, and in particular, a material with good dimensional accuracy such as stainless steel and duralumin that can be processed is preferred. The cross-sectional shape of the spreading member used in the present invention is preferably a polygon.
Furthermore, as shown in FIGS. 7 and 8, the angle between the surface of the spreading member and the surface of the substrate to be coated, which is directed in the direction of travel of the spreading device indicated by the arrow, must be 30 ° or more. It is. When the angle is less than 30 °, the film thickness is not constant due to the lift applied to the spreading member by the cosmetic 5, and the measurement accuracy may be lowered depending on the cosmetic. In the case where the spread member is in the shape of a cylinder or an elliptical cylinder, the angle between the portion of the spread member closest to the substrate and the surface of the substrate to be coated is close to 0 °. The film thickness does not become constant due to the lift of the member.
Moreover, it is preferable that the height of the gap formed between the coating member tip 6 and the substrate is in the range of 20 to 25 μm. If it is less than 20 μm, a smooth coating film may not be obtained unless the processing accuracy of the spread-out member is extremely high. There is a possibility that it becomes a paint spreading device that cannot. If it is the range of 20-25 micrometers, it is an area | region where processing accuracy and mass productivity of a coating spreader are compatible. When the thickness exceeds 25 μm, the coating film becomes thick and the amount of ultraviolet rays that pass through the coating film decreases, resulting in a problem that a measuring instrument with higher sensitivity is required.

  When the spread member is used alone, the mass of the spread member is preferably 100 g or more, and more preferably 400 g or more. If the mass is small, it is easily affected by lift, and it becomes impossible to form a smooth film. Further, if the mass is too large, the substrate and the plate supporting it are distorted and the substrate becomes non-flat, which causes a change in the film thickness depending on the coating site. How much mass can be applied depends on the strength of the substrate and the supporting plate, but it cannot be generally stated, but when using ultra-duralumin with a thickness of 5 mm, it is weighted from the top of the spreading member and its own weight It has been observed that when the combined load exceeds 2 kg, the distortion of the substrate appears as a non-negligible magnitude.

Next, a method for measuring the UV protection effect using the coating and spreading apparatus of the present invention will be described.
As shown in FIG. 9, the spreading device 1 is moved on the substrate 4, and a sample such as a cosmetic is uniformly applied on the substrate 4. In FIG. 9, the mechanism for moving the spreading device 1 on the substrate 4 is not shown, but it moves at a constant speed as described below.
In addition, the sample such as cosmetics can be supplied to the front part of the spreading member at the start of spreading, but in that case, the lift force related to the spreading member, that is, Since the force to push the spreading member upward with a large amount of sample increases, when supplying the sample to the front part of the spreading member, an appropriate amount is supplied sequentially or continuously, or the sample is placed on the substrate in advance. 4. By spreading the coat using a spatula or the like on the top, the lift force related to the spread-out member is minimized as much as possible during the spread-out process, and the fluctuation amount of the lift is also small, that is, it exists in the front portion of the spread-out member. It is necessary to reduce the number of samples as much as possible in order to form a smoother coating film.
As the spreading device is moved, it is necessary to eliminate the uneven thickness of the sample due to the formation of the stripe pattern indicated by S formed in parallel with the moving direction as shown in FIG. As shown in FIG. 10, which shows a state cut along the line AA in FIG. 9, it is required to eliminate unevenness in the thickness of the stripe formed in the direction perpendicular to the moving direction.

For this purpose, the following conditions are set.
In the present invention, the coating at a constant speed means that the substrate or the spreader device is moved at a constant speed by using a device that can move at a constant speed, such as an electric cylinder, an electric actuator, an industrial robot, and a transfer machine. In particular, those using linear motors have high speed stability in the low speed range and large torque, so that stable coating can be achieved even with heavy metal spreading equipment, speed And the history of acceleration remains. The constant speed is preferably 1 to 10 mm per second, more preferably 1 to 5 mm per second. If it is less than 1 mm per second, it takes too much time for coating, and the volatile solvent contained in the cosmetic may volatilize during coating, resulting in non-uniformity of components due to the coating film part. There is a problem that a stripe pattern is easily formed. Considering workability and volatility problems, the setting of 5 mm per second is most preferable.

  A bar coater or the like for applying paint is applied by moving the object to be coated at a high speed of 150 mm per second. If the viscosity is low, such as paint, it is applied at this speed. Even if it is processed, the stripe pattern disappears with time, but in the present invention, since it is a cosmetic, it is not necessary to apply at a high speed such as 150 mm per second, and the cosmetic has a higher viscosity. Since coating is difficult because it is easy to apply lift and smooth coating is required, it is necessary to apply at very low speed. The conditions for forming the coating film are completely different in principle. The smooth coating film referred to in the present invention refers to a coating film having not only irregularities on the surface but also a constant film thickness.

In the present invention, as a means for coating at a constant speed using a spreader, for example, a linear motor having a constant speed motion means at a low speed as described in Non-Patent Document 8, an electric cylinder, etc. Metal plate or column processed smoothly (high strength, light specific gravity material such as ultra-duralumin is preferable in order to suppress deformation due to its own weight or due to the load of the spreading member) via the support part For example, a bar or the like serving as a fixing means for the spreading member is installed on the horizontal fixing or connecting, and a substrate or a spreading member for coating is installed on the bar.
This means that there is no commercial product, so a custom or self-made product is required.
In addition, commercially available coating test equipment for paint testing generally uses a motor and gear ratio suitable for high-speed coating, and the stability and accuracy of the speed in the low speed range is poor, and a smooth coating film is applied. It is often not suitable for the purpose of forming. Looking at the coating tester catalog, in general, the unit of m / min is used as the unit of coating speed, and the speed adjustment is also a unit of 1 m / min, originally expressed in units of mm / min to cm / min. Low speed is an area not within the concept of these devices. In particular, cosmetics have various viscosities, thixotropic properties, and adhesive properties. When such a preparation is applied smoothly, sufficient torque and speed stability are required for the application means. In general, a paint tester has a structure in which a coating device is fixed and firmly pressed onto a coated surface. However, for example, when both ends of the coating device are fixed, the coating film thickness changes at the center and the end, and there is a problem that a smooth coating film cannot be formed, and the coating device is pressed onto the coating surface. In the coating tester having the above, there is a problem that it is difficult to obtain the coating accuracy required by the present invention.

The substrate 4 used in the present invention needs to be smooth. The term “smooth” as used in the present invention means that when the average coating amount and standard deviation per unit area are measured, the value of standard deviation / average coating amount is 0.15 or less, preferably 0.1 or less. Here, if there are irregularities, the film thickness of the coating film changes at the irregularities, and in the step of calculating the ultraviolet ray protection effect at the target coating amount per unit area by calculation, the ultraviolet rays obtained There is a problem that the measurement value of the defense effect becomes inaccurate. For example, the Colipa (European Cosmetic Industry Association) method uses uneven PMMA (polymethylmethacrylate) plates, but the unevenness is about 2 μm. Since the film thickness of the sample coated using a spreading member having a gap of 25 μm with respect to the substrate is 10 μm or less, this unevenness gives a fluctuation of several tens of percent of the average film thickness. In the case of a product having a high UV protection effect, the fluctuation range has a huge influence on the measurement value of the UV protection effect, which is not preferable because it causes a loss of reliability. For the substrate 4 used in the present invention, it is preferable to use a material such as quartz, synthetic quartz, polymethyl methacrylate, etc., which is transparent to ultraviolet rays in the range of 290 to 400 nm. In consideration of the subsidence of quartz, a substrate made of quartz or synthetic quartz, which is a hard material, is more preferable.
In order to obtain the average coating amount and the standard deviation, the coating amount is measured for a plurality of points on the substrate and / or a coating film formed on the plurality of substrates.

In the present invention, when the coating spreader 1 is used for smooth coating on a substrate at a constant speed, there is a feature in how to place a sample. In the case of cosmetics with low viscosity, even if a sufficient sample is placed in front of the spreading device in the direction of travel, the effect of lift is small, but in the case of cosmetics with high viscosity, the spreading material is likely to be lifted and the film There is a problem that the thickness tends to fluctuate. In particular, if there is a large lump of cosmetic material on the front surface in the direction of travel of the paint spreading device, the paint spreading member will ride on the cosmetic material, causing a non-uniform film thickness. Therefore, it is preferable that the cosmetic is thinly spread on the front surface in the traveling direction of the spreader device in advance using a spatula or the like, and then the spreader is quickly run to form a smooth coating film. Moreover, although it is the quantity which can be spread, when it is too small, it will become a cause of non-uniform film thickness. As a guideline, it is preferable to spread an amount of about ²⁰ to 30 mg / cm ² .

  The spreading device used in the present invention is not the dimension of the portion corresponding to the passage of the sample (the length in the traveling direction of the spreading device, that is, the width of the tip portion 6 of the spreading member in FIG. 6). The maximum / minimum value is preferably less than twice.

When measuring the coating amount per unit area of the sample by the method of the present invention, it is preferable to follow the following method as shown in FIG. However, as long as the purpose can be achieved, the order of execution is not limited, and some of the steps can be simplified.
A) A resin film 7 having a volatile component used in cosmetics that is impermeable to hardly permeable and cut into a certain size is prepared.
B) The mass per unit area of the resin film 7 is obtained.
C) The mass of the cut resin film 7 is measured, and the area of the cut resin film 7 is determined from the mass per unit area.
D) Determine the mass of the substrate 4 to be measured.
E) According to the method of the present invention, the cosmetic sample 5 is applied, and the film cut immediately thereafter is left on the surface of the sample 5.
F) Wipe off the sample that is not covered with the resin film 7.
G) Measure the mass of the sample consisting of the resin film, cosmetic and substrate.
H) The mass of the cosmetic material per unit area is measured from the above measured value.

As the resin film having a volatile component used in cosmetics that is impermeable to hardly permeable, a film made of polypropylene or polyethylene terephthalate is preferable, and a film made of polyethylene terephthalate having a thickness of 50 to 100 μm is particularly preferable. By covering the sample with a resin film immediately after coating, volatilization of volatile components can be suppressed and a stable measurement value can be obtained. If the volatile components volatilize during measurement, the concentration of the cosmetic will change and the viscosity will increase accordingly, so the exact coating amount cannot be measured and depends on the time until measurement. As a result, the measured value changes, and even if the same sample is measured, the variation range of the measured value by the measurement organization and the measurer increases.
In addition, as can be said for the whole measurement, in the case of the present invention, the measurement is accurately performed to the unit of 0.1 mg. At this time, in order to be strongly affected by the static electricity of the sample, it is preferable to perform the measurement by sufficiently removing the sample with a static eliminator.

  Moreover, when measuring the film thickness of a sample, it is possible to use a non-contact optical film thickness measuring apparatus.

Next, in the step of measuring the ultraviolet protective effect of the sample coated smoothly, it is preferable to use a commercially available ultraviolet protective effect measuring device such as an SPF analyzer. Examples of the measuring device include the devices described in Table 1 of (Non-Patent Document 5).
When measuring the sample, it is preferable to measure a position as far as possible from the coating start position of the sample as the measurement site. Moreover, it is preferable to measure the range of 290 to 400 nm in 1 nm units.

Next, the step of calculating the UV protection effect at the target coating amount per specific unit area from the data of step c) and step d) of the present invention will be described. Through the above-described steps, the coating amount (or film thickness) per unit area and the UV protection effect for each wavelength in the coating amount can be measured. However, the coating amount varies depending on the sample and is not the same, so the measured values as they are cannot be compared with each other. Therefore, the coating amount per specific unit area is set, and according to the value, the absorbance (or transmittance) by wavelength is calculated, and the SPF value or UVA-PF (A-wave UV protection index) value It is necessary to ask.
Assuming that the coating amount per specific unit area is M and the actual coating amount per unit area of the sample is N, the value of M / N is multiplied by the absorbance for each wavelength. The UV protection effect curve is obtained by calculation, and the SPF value and UVA-PF value are calculated from this curve. In the case of the film thickness standard, a target film thickness is determined, an ultraviolet ray protection effect curve is obtained by the same operation, and an SPF value and a UVA-PF value are calculated from this curve. Note that it is also possible to obtain it based on transmittance instead of absorbance.

At this stage, the target coating amount per specific unit area is unknown. Therefore, after purchasing a commercial product, the relationship between the SPF value, PA classification, and the above calculated value indicates how much the target coating amount per specific unit area is I checked to see if it was close.
For Japanese products, based on the products of Shiseido and Kanebo Cosmetics, the measured value is close to the displayed value when the coating amount is 1.0 mg / cm ² . On the other hand, based on the product of European L'Oreal, the measured value is close to the displayed value when the coating amount is 0.75 mg / cm ² . At this time, it is preferable to draw a graph of the coating amount, SPF value, and UVA-PF value to obtain an approximate expression. In the case of liquid cosmetics, it is preferable to use linear approximation or exponential approximation. In calculating this value, SPF and UVA-PF were calculated using SPF V3.0 software included with SPF-290S manufactured by Optometrics, and the value of Erythermal UVA PF was used as UVA-PF. It is also possible to use a UV protection effect calculation program currently being studied in each region.

The measurement method when the sample is a powder cosmetic is shown below.
Measurement of powder cosmetics is difficult even in the in vivo method, and the measured values tend to vary greatly. Since powder cosmetics are difficult to apply alone, the Japanese standard for measurement methods (Non-patent Document 26.4.2 Powder) states that “Purified water before applying powder to stably place the sample on the application site” Or a solvent that does not have ultraviolet absorbing ability may be applied. When a solvent that does not have UV-absorbing ability is mixed with the sample, the UV protection effect of cosmetics is greatly affected by the volatility of the solvent, and the UV protection effect measurement value decreases when a solvent such as water with low volatility is used in combination. However, when a highly volatile solvent is used and volatilized and then measured, the UV protection effect measurement value becomes high.
This is due to the fact that ultraviolet rays are transmitted from the portion of the solvent that does not have ultraviolet absorbing ability, but the measurement method for this portion has not been determined, and the type of solvent that does not have ultraviolet absorbing ability and It is also a problem that the method is not unified because the quantity is not fixed. Therefore, there is a problem that the measurement value of the standard commercial product itself is not reliable. Naturally, if the same sample preparation method is used also in the in vitro method, the coating film becomes non-uniform, and the UV protection effect obtained varies greatly even with the same sample depending on how the sample is prepared. On the other hand, according to the following method, it is possible to measure the powder cosmetics stably and with good reproducibility. That is, by displaying the measurement value measured by this method on a product, it is possible to provide a more accurate product selection index for the consumer.

In this method, first, a powder cosmetic and a volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure are mixed in a mass ratio of 100: 100 to 100: 50 to the above method. Apply according to the procedure and check the coating amount per unit area. Then, calculate the coating amount of the powder cosmetic only from the mixing ratio with the volatile solvent, create a sample with the volatile solvent removed in the temperature range of 30-50 ° C under ventilation, and measure the UV protection effect And measuring the ultraviolet protection effect of the powder cosmetic.
First, by mixing a solvent with the powder cosmetic, it becomes possible to apply the powder smoothly by a spreader. If the coating is performed in a powder state without mixing the solvent, it is extremely difficult to perform a smooth coating. Furthermore, the volatile solvent with a boiling point of 240 ° C or higher under atmospheric pressure is used because the volatile solvent is less than 240 ° C, and the volatility is too high. This is because they cannot.
Various tests were conducted on volatile solvents having different boiling points under atmospheric pressure. The measured value was somewhat unstable for dimethylpolysiloxane having a boiling point of 230 ° C (viscosity 2 mm ² / s), whereas volatile cyclic 6 at 245 ° C was used. Since the measured value was stable with the monomeric dimethylpolysiloxane, a solvent having a boiling point of 240 ° C. or higher is preferable.
However, if the boiling point is too high, not only the added volatile solvent but also other components originally contained in the powder cosmetic may volatilize in the drying process. Hexameric dimethylpolysiloxane (boiling point 245 ° C), caprylyl methicone (Dow Corning catalog http://www.dowcorning.co.jp/en_JP/content/japan/japanproducts/Y517_Personal_Care_.pdf 3 page boiling point above 100 ° C) However, it is preferable to use a cyclic hexamer dimethylpolysiloxane because it is volatile and can be stably measured.
In the present invention, a powder cosmetic and a volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure are mixed in a mass ratio of 100: 100 to 100: 50. If the ratio of the volatile solvent exceeds 100: 100, it is not preferable because uneven coating occurs during coating or solid-liquid separation occurs. Moreover, when 100: 50 is divided, viscosity may become high depending on a formulation, and coating defect may arise.

  In the present invention, the slurry obtained by mixing the powder cosmetic thus obtained and a volatile solvent is applied according to the above-described method, and the coating amount per unit area is examined. However, the difference from the above-mentioned method is that the coating amount as a powder cosmetic obtained by multiplying the actually measured value by the mixing ratio is used. Moreover, it is preferable that the sample for measuring the ultraviolet ray protection effect is once coated smoothly and then dried at 30 to 50 ° C., more preferably 40 ° C. under blowing. In the case of mixing 100: 100 with volatile cyclic hexamer dimethylpolysiloxane, volatilization of the volatile solvent is completed in about 1 hour at 40 ° C.

Based on the data obtained from these steps, the UV protection effect at a specific coating amount per specific unit area is measured. At this time, it is preferable to draw an approximate expression by drawing a graph of the coating amount, SPF value, and UVA-PF value. For the powder cosmetics, not linear approximation, R ² squared value showing a correlation between use of exponential approximation is preferable because it exhibits a value close to 1 or 1.

  In any of the above measurements for liquid cosmetics and powder cosmetics, it is preferable to carry out the measurement twice or more, and if the numerical values deviate greatly, they are tested again to eliminate the error data. In particular, when a stripe pattern enters the surface of the coating film or when uneven color is observed, the test is necessary again.

  The present invention is an apparatus for performing these methods, and includes each apparatus for performing each of the above steps, and includes a part or all of the steps for measuring the UV protection effect, and automatically provides the UV protection effect. It can also be set as the apparatus which measures.

  The present invention can be applied to a display method that displays a measurement value or an index obtained by the above method. This method is a method with higher accuracy than any currently studied method, elimination of individual differences of measurers, high reproducibility, and more accurate measurement can be performed more easily than before, There is an advantage that more appropriate UV countermeasure guidance can be provided to consumers. In particular, the maximum PA display currently implemented in Japan is PA +++, which is equivalent to 8 or more in terms of UVA-PF, but European products exist that exceed the double level. In fact, PA +++ is supposed to suppress skin blackening, but in actuality blackening occurs, so there is a problem that the actual performance does not match the contents explained as an indicator, in order to accurately show this In addition, the display method of the result of this method is very effective. Note that the display method used for the display object may not be the measurement value itself of the present invention, but may be a mark or category notation.

The present invention will be described in detail below based on examples, but the present invention is not limited thereto.
(Reference example)
When the same model as the spreading device described in paragraphs 0067 to 0071 of Patent Document 3 was purchased and examined, the 1.5Mils (25 μm) part measured the dimensions of both ends and the center part. It became 0.60mm and 0.53mm. As a sample, 5.0% by mass of Parahermosa Organic UV Protection Agent UV Absolute 5 was mixed with Toray Dow Corning Silicone Rubber SE9140RTV, and parallel to the direction of travel at a speed of 5mm per second using this spreader. Examination of the coating amount of each such direction 1 cm, relative to the average coating weight 2.52mg / cm ^2, the standard deviation was 0.205 mg / cm ² (standard deviation / average coating weight = 0.081). Next was examined the coating amount of each direction perpendicular 1cm in the traveling direction, the average relative coating weight 2.36mg / cm ^2, the standard deviation is 0.174 mg / cm ² (standard deviation / average coating weight = 0.074). Although the value of the standard deviation / average coating amount was not so large, the coating amount per unit area of the coating film at a specific position tended to vary.

  Therefore, in consideration of the possibility that the size of the part corresponding to the passage of the sample affects the coating amount, the angle with the substrate on the front surface in the traveling direction of the spreader is set to 30 °, and the part corresponding to the passage of the sample Size, that is, the width is 1.00mm, 2.00mm, 3.00mm and the gap spreader is 30μm, and the coating amount per unit area, standard deviation, standard deviation, coating amount per unit area As shown in Table 1, it was found that the coating amount per unit area greatly changed depending on the size of the portion corresponding to the passage of the sample, as shown in Table 1. From this test result, since the size of the part corresponding to the passage of the sample in the coating spreader of Patent Document 3 has greatly fluctuated, the coating amount per unit area partially fluctuates and shows a specific tendency. That is, it can be seen that the coating film was not smooth.

(Guideline of coating amount in Examples)
In the examples, the coating amount of the sample was 0.75 mg / cm ² or 1.0 mg / cm ² . This is the amount of coating necessary for the display of the commercial cosmetics displayed based on the measured value by the in vivo method as described above and the measured value obtained based on the present invention to show similar values. It is.

  In the present invention, the coating amount per unit area of the sample coated smoothly or the film thickness is measured, but the measurement site is preferably 15 mm or more away from the coating start position of the sample, more preferably Is preferably separated by 20 mm or more. This is because the spreading member is unstable immediately after the start of coating, and the thickness of the coating film becomes slightly thick. Due to these conditions, in this method, in the case of a general sunscreen agent, the fluctuation range is less than 10% on the basis of the coating amount per unit area.

1. Example 1 (Measurement of liquid cosmetics)
Specific measurement examples are shown below.
(1) A step of measuring the coating amount or film thickness per unit area of a sample coated smoothly on a substrate at a constant speed using a coating spreader and the direction of travel of the coating spreader and the substrate are formed Angle of 61.6 °, gap 25μm, weight of spread member 441.6g, sample passage size 3.34mm, spread member width 79.99mm, sample passage direction of the stainless steel with attributes parallel to the substrate A commercially available cosmetic (manufactured by Kanebo Cosmetics Co., Ltd., display SPF50 + PA +++ 2010 product W / O type sunscreen agent) was measured using the spread member. A smooth quartz plate was used as the substrate. The coating speed was 5 mm per second.
The mass of a quartz plate and a 100 μm-thick polyethylene terephthalate (PET) film cut to a size of 5 cm × 5 cm was accurately measured to a unit of 0.1 mg. In the measurement, static electricity was sufficiently removed using a static eliminator. A spreader was placed on the quartz plate, and cosmetic was spread over the entire front surface. Immediately after moving the coating spreader under the above conditions, the PET film was allowed to stand from a site about 20 mm away from the coating start site to around 70 mm. The cosmetic around the film was removed using tissue paper and a cotton swab so as not to touch the PET film. Next, the static electricity was sufficiently removed, and the mass of the sample composed of the quartz plate, the cosmetic material, and the PET film was accurately measured to the unit of 0.1 mg. From the result of mass measurement of this PET film, it was found that the exact area was 25.0 cm ² and the mass of the cosmetic sandwiched between the PET film and the quartz plate was 42.3 mg. The work amount was found to be 1.69 mg / cm ² . This operation was repeated and it was confirmed that the measured values were reproducible.

(2) The process of measuring the UV protection effect of the sample coated smoothly The cosmetic coating film is formed on the quartz plate by the same method as described above, and the UV protection effect is measured by the UV protection effect measuring instrument manufactured by Optometrics. Using SPF-290S, the transmittance of ultraviolet rays in the wavelength range of 290 to 400 nm was measured every 1 nm. The SPF value calculated using SPF V3.0, which is computer software attached to the apparatus, was 199.68 standard deviation 7.84, and the Erythermal UVA-PF value was 33.1 standard deviation 1.3. The value of the standard deviation and the ratio of the standard deviation to the measured value were smaller than the values obtained by the usual in vitro measurement method. The measurement position of the UV protection effect was carried out at a site 6 cm away from the coating start position. The measurement was carried out twice and it was confirmed that there was reproducibility.

(3) The step of calculating the UV protection effect in the target coating amount per unit area from the data of the step (1) and (2) by calculation From the step (2) of the tested cosmetic A transmittance curve was obtained when the coating amount per unit area was 1.69 mg / cm ² . Assuming that the coating amount per unit area to be obtained is, for example, 1.00 mg / cm ² , it can be seen that the coating amount is different by 1.00 ÷ 1.69 = 0.592 times. Converting the transmittance absorbance multiplied by 0.592 times in each wavelength by the absorbance when the coating amount per unit area equal coating weight from the data when the 1.69 mg / cm ² is 1.00 mg / cm ² Can be predicted. This absorbance curve was programmed using Microsoft Excel software. And using this absorbance data, the SPF value determined by the above software was 67.0, and the Erythermal UVA-PF value was 13.67. Similarly, absorbance curves at 0.75 mg / cm ² and absorbance curves at 1.50 and 0.75 mg / cm ² were obtained, and the respective SPF values and UVA-PF values were graphed. For example, when obtaining an approximate curve of SPF and UVA-PF by linear approximation from the data of FIG. 1, assuming that the coating amount per unit area is X, the SPF value is 209.08X−134, UVA-PF the value, UVA-PF value = 31.307X-16.439 next, each of R ² squared (contribution ratio) became 0.9931 and 0.9906. From this approximate expression, the relationship between the coating amount, SPF value, and UVA-PF value was obtained. In addition, when using an approximate expression, it is preferable to obtain | require an approximate expression from the figure by which the data before and behind the coating amount per unit area to obtain | require are plotted. This is because the range of the coating amount per unit area that can ensure linearity is limited.

In this method, the target coating amount is obtained by calculation from the coating amount per unit area. Theoretically, this is not a problem, but whether or not there is linearity between the coating amount per unit area and the absorbance actually creates a spread member with different gaps and the coating amount per unit area differs. When a sample was prepared and confirmed, a good linear relationship was obtained, so it was confirmed that the theoretical formula could be applied in an actual test.
In addition, even when a new coating was made using the same sample, almost the same numbers were shown, indicating that the test reproducibility was ensured.

2. Example 2 (Measurement results of commercial products)
Tables 2 and 3 show the results of tests using commercially available sunscreen agents.
Here, the relationship between the PA classification and the UVA-PF corresponds to PA + of UVA-PF value of 2 to 4, PA ++ of UVA-PF value of 4 to 8, and PA +++ of UVA-PF value of 8 or more. SPF50 + indicates that the SPF value is 51 or more. In Tables 2 and 3, “before conversion” indicates SPF and Erythermal UVA-PF values and their standard deviations when the coating amount per unit area is applied. After conversion in Table 2, the SPF value and Erythermal UVA-PF value calculated in the case of 1 mg / cm ² coating are calculated. In Table 3, after conversion, SPF values and Erythermal UVA-PF values calculated for calculation when 0.75 mg / cm ² and 1 mg / cm ^{2 were} applied are shown.
From the results in Table 2, it can be seen that stable measured values were obtained when the method of the present invention was used. Although the standard deviation is slightly larger from the results in Table 3, this is due to the use of the region where the sensitivity of the sensor is at the limit, and the absorbance curves are almost the same, so the method of the present invention. It can be said that a stable measurement value is obtained. Furthermore, in the case of European products, it can be seen that a result closer to the displayed value is obtained when it is assumed that 0.75 mg / cm ^{2 is} applied. In addition, the standard deviation / SPF value before conversion and the standard deviation / UVA-PF value before conversion are also very small, indicating that a smooth coating film is stably obtained.

3. Example 3 (Measurement of powder cosmetics)
Specific measurement examples are shown below.
(1) A step of measuring a coating amount per unit area or a film thickness of a sample coated smoothly on a substrate at a constant speed using a spreading member whose cross section is not a circle or an ellipse. , Measurement of a commercially available powder cosmetic (manufactured by Kanebo Cosmetics Co., Ltd., display SPF20 PA ++ 2010 product, powder foundation) was carried out using the same stainless steel spreading member as that used in the measurement of cosmetics. A smooth quartz plate was used as the substrate. The coating speed was 5 mm per second. The mass of a quartz plate and a 100 μm-thick PET film cut to a size of 5 cm × 5 cm was accurately measured to a unit of 0.1 mg. In the measurement, static electricity was sufficiently removed using a static eliminator. A sample was prepared by manually mixing powder cosmetic and volatile cyclic hexamer dimethylpolysiloxane (boiling point 245 ° C.) with a spatula at a mass ratio of 1: 1. A spreader was placed on the quartz plate, and the sample was spread over the entire front surface. Immediately after moving the coating spreader under the above conditions, the PET film was allowed to stand from a site about 20 mm away from the coating start site to around 70 mm. The cosmetic around the film was removed using tissue paper and a cotton swab so as not to touch the PET film. Next, the static electricity was sufficiently removed, and the mass of the sample composed of the quartz plate, the cosmetic material, and the PET film was accurately measured to the unit of 0.1 mg. From the result of mass measurement of this PET film, it was found that the exact area was 24.5 cm ² and the mass of the cosmetic sandwiched between the PET film and the quartz plate was 48.7 mg. The work amount was found to be 1.99 mg / cm ² . Since it is mixed with a volatile solvent at a mass ratio of 1: 1, the coating amount per unit area of only the powder cosmetic is 1.00 mg / cm ² , which is half. These operations were performed at room temperature of 26.2 ° C.

(2) The process of measuring the UV protection effect of the smooth coated sample A coating film of the powder cosmetic is formed on the quartz plate by the same method as described above, and stored in an air dryer at 40 ° C. Mass change was examined every 10 minutes. As a result, it was found that the mass was stabilized in 1 hour and the volatile solvent was removed. Using this sample, the UV protection effect was measured in the same manner as the liquid cosmetic. As a result, the SPF value was 63.37 standard deviation 4.35, and the Erythermal UVA-PF value was 49.72 standard deviation 3.16. The value of the standard deviation and the ratio of the standard deviation to the measured value were smaller than the values obtained by the usual in vitro measurement method.

(3) The step of calculating the UV protection effect at the target coating amount per unit area from the data of the step (1) and (2) by calculation The unit of cosmetics tested from the step b) A transmittance curve was obtained when the coating amount per area was 1.00 mg / cm ² . Similarly, transmittance curves at 0.50, 0.75, and 1.00 mg / cm ² were obtained, and the SPF value and UVA-PF value of each obtained as a graph are shown in FIG. When an approximate curve of SPF and UVA-PF is obtained by exponential approximation from the data in FIG. 2, when the coating amount per unit area is X, the SPF value is 1.0048e ^4.1441X , UVA-PF value for, UVA-PF value = 1.0144e ^3.8926X next, each of R ² squared (contribution ratio) became 1.0. From this approximate expression, the relationship between the coating amount, SPF value, and UVA-PF value was obtained.
Moreover, it was confirmed that this measurement has reproducibility in each step and in the final result.

4). Example 4 (Measurement of other powder cosmetics)
Using a similar method, a test was conducted on powder cosmetics (powder foundation, product in 2010) manufactured by Kanebo Cosmetics.
Table 4 shows the results. As a result of obtaining an approximate curve and determining the relationship with each displayed value, the SPF value is based on a coating amount of 0.75 mg / cm ² and the Erythermal UVA-PF value is based on 0.50 mg / cm ² as the displayed value. It was found that the value was relatively close to. From the results of Table 4, it can be seen that when the method of the present invention is used, the in vitro measurement of powder cosmetics, which has been impossible in the past, can be carried out stably. Also, the standard deviation / SPF value before conversion and the standard deviation / UVA-PF value before conversion are very small, indicating that a smooth coating film can be stably obtained even in powder cosmetics.

  Measurements were also made for powder cosmetics from manufacturers other than Kanebo Cosmetics. Although the measurement can be carried out with good reproducibility, there is a large discrepancy between the displayed values and the measured values, and the measured values are relatively stable like Kanebo Cosmetics. Did not become. This is expected to be related to the problem of the measurement procedure in the in vivo method.

5. Comparative Example 1
Table 5 shows the results when the coating amount per unit area was tested using various volatile solvents in place of the combination of the powder cosmetic and the volatile cyclic hexamer dimethylpolysiloxane. The test method was carried out in accordance with the above powder cosmetic method, and the mixing mass ratio of the powder cosmetic and the volatile solvent was 1: 1. The test was conducted at 26.1 ° C. As shown in Table 5, a volatile solvent having a boiling point of 230 ° C. or lower under atmospheric pressure cannot suppress the volatilization of the volatile solvent even when it is covered with a resin film, and the measured value fluctuates over time. It turns out that the amount of work cannot be measured accurately.

6). Example 5 (Measurement and labeling of formulations with unknown SPF and UVA-PF values (PA classification))
In the above, the analysis method of the commercial product which has already displayed the measured value has been shown. Below, the measurement about an unknown sample and the example of a display are shown.
A liquid foundation containing 7.5% by mass of UV-absolute 5, an organic UV protection agent manufactured by Paraermosa, was prepared, and the SPF value and UVA-PF when the coating amount per unit area was 0.75mg / cm ² according to European products. Values (PA classification) were obtained. The blending ratio of pigments and the like was the same even if the dosage form was different. The results are shown in Table 6. The display value of the product was calculated | required from the result of Table 6, and the display thing was produced.

  From the results of Table 6, both the SPF value and the UVA-PF value of the O / W (oil-in-water preparation, water content 40%) dosage form were significantly reduced compared to the oil-based dosage form. Conventionally, as described above, the measurement value itself is inaccurate, and the fluctuation of the measurement value is large, so that the influence of the dosage form cannot be accurately grasped. Since this method can measure an accurate UV protection effect, the degree of deterioration of the UV protection effect due to the influence of the aqueous phase of the oil-in-water preparation was quantitatively and clearly shown in numerical form. From this, it is expected that the method of the present invention will be a tool that not only obtains measurement values, but also enables accurate review of conventional dosage forms focusing on the UV protection effect and improvement of manufacturing technology.

7). Comparative Example 2 (Influence of sample preparation method)
Table 7 shows the results of an examination of how much fluctuation occurs when applied with a human finger that is currently used as a standard. As a sample, a cream containing 15.0% by mass of UV cocktail JP-6 manufactured by Paraermosa was used, and the coating amount was 2 mg / cm ² . In the standard measurement method of the manufacturer, a method in which a transpore tape was applied to a quartz plate and a sample was carefully applied thereto, a large number of stripe patterns were formed on the surface. Even when measured without the transpore tape attached, the values are quite different. When the finger is applied directly to the quartz plate, it can be seen that the measured value varies greatly depending on how the finger is moved. It can be seen that when a sample is sandwiched between two quartz plates so as not to form a stripe pattern, the measurement value is very large. As described above, even if all of the coating amounts are 2 mg / cm ² , such a large change in numerical values is caused only by the difference in the method of preparing the sample. If you are an expert, the apparent measurement value seems to settle down near some numerical value, but the number does not reflect the UV protection effect of the sample correctly, and it does not make sense From the test results.

  In addition, the measuring method by the pinching | pinching of Table 7 is a method which can form the coating film similar to the smooth coating film which this invention aimed at. However, this method cannot be used for general purposes because it cannot be used depending on the cosmetic dosage form or the number may fluctuate greatly. Specifically, in the case of a preparation containing a large amount of air, there is a problem that air holes are formed in the coating film in the process of forming a thin film by sandwiching, and ultraviolet rays are transmitted therethrough. In addition, in a cosmetic that easily causes phase separation, components may be separated or agglomerated during the thinning process, and the performance may be displayed worse than the actual state. Therefore, although data as shown in Table 7 is given depending on the preparation, it should be noted that reproducibility may not be obtained.

8). Comparative Example 3 (Influence on SPF value when a cylindrical metal spread-out member is used)
A baker type applicator was used as the applicator, and the gap setting was set to zero. A sample prepared by mixing 15.0% by mass of an organic UV protective agent UV cocktail JP-6 manufactured by Paraermosa with silicone rubber SE9140RTV (UV transparent one-component silicone RTV rubber) manufactured by Toray Dow Corning was used as a sample. An ultraviolet transmissive polypropylene film was used, and the sample was coated on the film while changing the load of the applicator so as to be ² mg / cm ² . Incidentally, the coating amount of ² mg / cm ² corresponds to the amount used in the SPF measurement standard by the in vivo method. Table 8 shows the results of measuring the SPF value of this sample using an SPF290S type measuring instrument manufactured by Optometrics. The period of the stripe pattern is based on observation with an optical microscope. From the results in Table 8, it can be seen that the SPF values obtained are greatly different even at the same 2 mg / cm ² coating amount. In the case of this sample, a stripe pattern was formed even at a coating speed of 5 mm per second. An example of a stripe pattern is shown in FIG. In general, when the coating speed is slow, the stripe groove is deep, and when the coating speed is fast, the stripe groove becomes shallow, and ultraviolet rays are transmitted through this groove. When used, the effect greatly affects the SPF value. Therefore, it is necessary to apply a coating that does not cause a stripe pattern.

9. Comparative example 4 (wire coater)
In the coating application test, a coating device in which a wire is densely wound around a metal rod called a wire coater is often used. Therefore, using a wire coater (No. 5), two kinds of sunscreen agents (indicated SPF50 +, PA +++) manufactured by Shiseido Co., Ltd. were used as samples, and each was applied at a coating speed of 5 mm per second, and the UV protection effect was examined. . As a result, although the fluctuation range of the measured value was small at one point, the coating film became non-uniform and the measured value varied greatly at the other point. Although it is possible to use a wire coater depending on the preparation, it was found that the wire coater-derived streaks remain in the high-viscosity product, so that it was not a universally usable instrument.

10. Example 6 and Comparative Example 5 (Influence of the angle of the traveling method of the spreading device)
Set the angle between the extension line of the surface in contact with the sample and the substrate to be coated in the direction of travel of the spreader to 10, 20, 25, 30 °, and fix the dimension of the part corresponding to the sample passage to 3 mm. When the coating was performed at a speed of 5 mm per second, the coating amount per unit area, standard deviation, and standard deviation / coating amount were determined. The sample used was a mixture of 5.0% by mass of UV absolute 5 manufactured by Paraermosa and silicone rubber SE9140RTV manufactured by Toray Dow Corning. The coating was carried out on a UV-permeable polypropylene film. The results are shown in Table 9. When the angle is in the range of 10 to 25 °, the value of any standard deviation / coating amount is 0.1 or more, indicating that the fluctuation is large. It can be seen that if the angle is smaller than this, the lift applied to the spreading member increases and the vertical movement of the spreading member occurs. When the angle is 30 °, the standard deviation / coating amount per unit area is as small as 0.06, indicating that the effect of lift is reduced.

11. Example 7 and Comparative Example 6 (Influence by the gap of the spreading member)
Coating gap per unit area when the gap between the spreading members is set to 12.5μm, 20μm, 25μm, the dimension of the part corresponding to the passage of the sample is fixed to 3.34mm, and the coating is performed at a speed of 5mm per second Deviation, and standard deviation / value of coating amount per unit area were determined. A sample was prepared by mixing 5.0% by mass of an organic ultraviolet protective agent UV absolute 5 manufactured by Paraermosa with silicone rubber SE9140RTV manufactured by Toray Dow Corning. The coating was carried out on a UV-permeable polypropylene film. The results are shown in Table 10. When the gap is 12.5 μm, the thin part of the coating film is formed at the same position in multiple coatings, except that the standard deviation / coating amount per unit area is slightly larger. Is doubtful. The manufacturer of the spreader says that it is quite difficult to achieve accuracy at 12.5μm, so if the processing accuracy increases and stable high-precision spreader cannot be created, the 12.5μm gap The spreader is difficult to use. On the other hand, when the gap was 20 μm or 25 μm, stable coating could be performed. From this result, it can be seen that the gap is preferably set in the range of 20 to 25 μm.

12 Comparative Example 7 (Effect of substrate unevenness on stripe pattern)
Each of the above tests was performed on a smooth substrate, but it was tested whether or not a stripe pattern was formed when it was performed on a substrate with unevenness. As the substrate with unevenness, a polymethyl methacrylate plate (the size of the unevenness was 2 μm) conforming to the Colypa method was used. The sample was prepared by mixing 5.0% by mass of Parahermosa's organic UV protection agent UV Absolute 5 with Toray Dow Corning's silicone rubber SE9140RTV, and applying a sack on the finger to 2 mg / cm ² . . The results are shown in FIG. FIG. 4 is an optical microscope image of the coating surface, and a stripe pattern is observed. From this, it can be seen that even if the substrate is uneven, a stripe pattern is formed and the problem is not solved.

DESCRIPTION OF SYMBOLS 1 ... Spreading apparatus 2 ... Spreading member 3 ... Supporting part 4 ... Substrate 5 ... Cosmetics 6 ... End of spreading member 7 ... Resin film

Claims (13)

The method to measure the ultraviolet-ray protective effect of liquid cosmetics which has the process of following a) -d).
a) The height of the gap between the tip of the spreading member and the substrate is in the range of 20 to 25 μm, and the spreading member whose angle to the substrate is 30 ° or more is 1 to 10 mm per second on the substrate. The step of applying and forming a smooth liquid cosmetic layer on the substrate by moving at a speed of.
b) A step of measuring a coating amount per unit area of a part of the substrate or a thickness of the layer in a state where the formed layer is not dried.
c) A step of measuring the UV protection effect of another liquid cosmetic layer obtained by the above step a)
d) A step of calculating the ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the above b) step and c) step. The method to measure the ultraviolet-ray protective effect of powder cosmetics which has the process of following e)-i).
e) A step of obtaining, as a sample, a composition comprising a powder cosmetic and a volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure in a mass ratio of 100: 100 to 100: 50. .
f) The height of the gap between the tip of the spreading member and the substrate is in the range of 20 to 25 μm, and the spreading member whose angle with the substrate is 30 ° or more is 1 to 10 mm per second on the substrate. The step of applying and forming a smooth liquid cosmetic layer on the substrate by moving at a speed of.
g) A step of measuring a coating amount per unit area of a part of the substrate or a thickness of the layer in a state where the formed layer is not dried.
h) a step of drying the other composition layer obtained in the step f) and measuring the ultraviolet protective effect of the composition layer after the drying.
i) A step of calculating an ultraviolet ray protection effect at a coating amount per unit area by calculation from the data obtained by the measurement in the step g) and the step h).   The method according to claim 2, wherein the volatile solvent having a boiling point of 240 ° C. or higher under atmospheric pressure is selected from cyclic hexamer dimethylpolysiloxane and caprylylmethicone.   The method according to claim 1, wherein the spreading speed of the spreading member on the substrate is in the range of 1 to 5 mm per second.   3. The method according to claim 1, wherein the substrate is selected from materials having a smooth surface and a property of transmitting ultraviolet rays in the range of 290 to 400 nm.   6. A method according to claim 5, characterized in that the substrate is selected from quartz plates or polymethyl methacrylate plates.   The method according to claim 1 or 2, wherein when the sample is applied to the substrate, the sample is thinly spread on the substrate in advance and then subjected to a smooth coating procedure with a spreader. The method described.   The method according to claim 1 or 2, wherein the part for measuring the coating amount or the film thickness is 15 mm or more away from the coating start position of the sample.   The method according to claim 8, wherein the portion for measuring the coating amount or the film thickness is 20 mm or more away from the coating start position of the sample. The method according to claim 1, wherein a method for calculating the coating amount per unit area of the liquid cosmetic applied smoothly is according to the following method.
A) A resin film is prepared in which the volatile component used in the liquid cosmetic is impermeable or hardly permeable.
B) The mass of the resin film is measured, and the area of the resin film is obtained.
C) The mass of the substrate on which the layer made of the liquid cosmetic is formed is determined.
D) Before the formed smooth liquid cosmetic layer is dried, the resin film is allowed to stand on a part of the surface of the liquid cosmetic layer.
E) The liquid cosmetic layer in a portion not covered with the resin film is removed.
F) The mass of the sample comprising the resin film, the liquid cosmetic layer, and the substrate is measured.
G) The mass of the cosmetic material per unit area is measured from the above measured value. The method according to claim 2, wherein the method for calculating the coating amount per unit area of the powder cosmetic applied smoothly is according to the following method.
A) A resin film in which a volatile solvent having a boiling point of 240 ° C. or higher mixed with the powder cosmetic is impermeable is prepared.
B) The mass of the resin film is measured, and the area of the resin film is obtained.
C) The mass of the substrate on which the layer composed of the composition is formed is determined.
D) Before the formed smooth composition layer is dried, the resin film is allowed to stand on a part of the surface of the composition layer.
E) The composition layer in a portion not covered with the resin film is removed.
F) The mass of the sample consisting of the resin film, the composition layer and the substrate is measured.
G) From the above measured value, the mass of the composition layer per unit area is measured.
H) The mass of the powder cosmetic in the composition layer is determined in consideration of the content of the powder cosmetic in the composition. The coating amount per unit area required for obtaining the intended ultraviolet protection effect is obtained based on the ultraviolet protection effect in the coating amount per unit area measured by the method according to claim 1 or 2. Method.   An apparatus for performing the method according to claim 1, comprising the apparatuses for performing the respective steps, and including a process for measuring an ultraviolet protection effect, and automatically measuring the ultraviolet protection effect. .