Flash material

Abstract

Provided is a novel flash material which has a size suitable for use as a bright tablet, does not contain a resin sheet, and exhibits excellent color development. The provided flash material contains a plurality of scale-like flakes having a particle size distribution D50 of 100 [mu] m or more, each of the plurality of scale-like flakes has a scale-like glass and a coating film on the scale-like glass, and the standard deviations [sigma] of a * and b * in the L * a * b * color system of transmission colors measured using a halogen lamp as a light source for 100 scale-like flakes are both 11 or less.

Description

Technical Field

[0001] The present invention relates to a glitter material comprising a plurality of scaly flakes. More particularly, the present invention relates to a glitter material having a size that allows it to be used as glitter flakes in cosmetics. Background Art

[0002] Cosmetics sometimes incorporate glittering materials called glitter flakes. Glitter flakes are thin sheets that impart a strong, grainy sheen. Glitter flakes typically use a laminate of resins with varying refractive indices. Another example of a glitter flake is a laminate containing a resin matrix onto which a metal such as aluminum has been vapor-deposited. Regardless, glitter flakes typically contain resin flakes. Glitter flakes are manufactured, for example, using the method disclosed in Patent Document 1. Glitter flakes are typically larger than 100 μm, with sizes ranging from several hundred μm to several millimeters.

[0003] Shiny materials called pearlescent agents are also known. Pearlescent agents are thin flakes that impart a pearl-like luster through light interference. The reflected light from pearlescent agents provides a superior texture. However, the reflected light from pearlescent agents generally lacks the graininess of light reflected from glitter sheets. Pearlescent agents are generally inorganic flakes with a light interference film, such as a titanium oxide film, formed on their surface. Inorganic substrates such as mica, talc, and glass can be used as the base for the light interference film in pearlescent agents. Pearlescent agents are generally around tens of microns in size.

[0004] As mentioned above, glitter flakes and pearlescent agents are used differently as different glitter materials.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-70479 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The discharge of discarded plastic products into the ocean is a problem. Microplastics, in particular, can impact ecosystems. Therefore, there is a desire to exclude resin from glitter materials used in glitter sheets. A known glitter material that can be used as glitter sheets without the inclusion of resin flakes is a titanium oxide film coated on large-particle mica. However, the color rendering of this glitter material is somewhat dull and lacks saturation.

[0010] Therefore, an object of the present invention is to provide a new glitter material having a size suitable for use as a glitter sheet, containing no resin flakes, and having good color development.

[0011] Means of solving the problem

[0012] The inventors analyzed the factors that cause dull color development and discovered that uniformizing the color development of each flake reduces dullness and improves saturation, leading to the completion of the present invention. While glass flakes are known to be useful as a base for pearlescent agents, where transparency is important, they also have great utility as a base for glittering materials such as glitter.

[0013] That is, the present invention provides, from its first aspect, a glittering material comprising a plurality of scaly flakes having a D50 of 100 μm or more, wherein:

[0014] Each of the plurality of scaly sheets comprises scaly glass and a coating on the scaly glass.

[0015] For 100 flake-like flakes, the transmittance color measured using a halogen lamp as the light source is L * a * b * In the color system a * and b * The standard deviation σ is less than 11.

[0016] The present invention, in its second aspect, provides a glittering material comprising a plurality of scaly flakes having a D50 of 100 μm or greater, wherein:

[0017] Each of the plurality of scaly sheets comprises scaly glass and a coating on the scaly glass.

[0018] D10 is 65 μm or more.

[0019] D10 and D50 are the particle sizes at which the volume accumulation from the smaller particle size reaches 10% and 50%, respectively, in the particle size distribution measured by laser diffraction and scattering methods.

[0020] Effects of the Invention

[0021] According to the present invention, a glittering material suitable for use as a glitter sheet can be obtained while avoiding the presence of resin flakes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram illustrating an example of an apparatus for producing glass flakes.

[0023] Figure 2 This is a schematic diagram illustrating another example of an apparatus for producing glass flakes. DETAILED DESCRIPTION

[0024] Hereinafter, the details of the present invention will be described, but the following description does not limit the present invention to the intention of a specific embodiment. In the following description, "D10" and "D50" are as described above, and "D90" means the particle size at which the volume accumulated from the side with the smallest particle size is 90% in the particle size distribution measured by the same laser diffraction and scattering method. "Main surface" means two surfaces with a relatively large area in the sheet and a spacing equivalent to the thickness. "End face" is a surface extending in the thickness direction and connecting the periphery of the two main surfaces. "Main component" means the component with the highest content in terms of mass standard. "Metal" follows the usual practice in this field and is used in the sense of a semiconductor including silicon, etc. The same applies to "metal compound" and "metal oxide" other than the case of "metal".

[0025] Regarding the hue of color, L * C * The hue angle h of the h color system is expressed as 0 degrees and less than 45 degrees and 315 degrees and less than 360 degrees as "red", 45 degrees and less than 135 degrees as "yellow", 135 degrees and less than 225 degrees as "green", and 225 degrees and less than 315 degrees as "blue". h and L * a * b * a color system * and b * At h = tan -1 (b * / a * ) relationship. Also, saturation can be represented by the equivalent of a * and b * The square root of the sum of the squares c * express.

[0026] The glittering material of the present invention comprises a plurality of flaky flakes having a D50 of 100 μm or greater. The plurality of flaky flakes each comprises a flaky glass and a coating on the flaky glass. The coating may cover the flaky glass.

[0027] Flake-like flakes with a D50 of 100 μm or greater are suitable for use as glitter sheets. D50 can be 120 μm or greater, 130 μm or greater, 135 μm or greater, 140 μm or greater, and in some cases, 150 μm or greater. The upper limit of D50 is not particularly limited, but is, for example, 3 mm or less, and further preferably 500 μm or less.

[0028] The D10 of the flaky flakes is preferably 65 μm or greater. In an aggregate of flaky flakes with such a high D10, the proportion of small-diameter flakes is limited. Small-diameter flakes have a relatively higher ratio of end faces across the entire surface of the flakes than large-diameter flakes. Therefore, limiting the proportion of small-diameter flakes can reduce the ratio of end faces across the entire surface of the glittering material. D10 can be 68 μm or greater, 70 μm or greater, 72 μm or greater, and, in some cases, 75 μm or greater. The upper limit of D10 is not particularly limited, but is, for example, 150 μm or less, 120 μm or less, and, in some cases, 90 μm or less.

[0029] Furthermore, the D10, D50, and D90 (described later) of the flaky flakes can be adjusted by controlling the particle size distribution of the glass flakes. Typically, the coating thickness is submicron, significantly smaller than the average particle size of the glass flakes (D50 ≥ 100μm). In this case, the particle size distribution of the flaky flakes can be considered to be essentially the same as that of the glass flakes. Even considering the effects of the extremely thin coating, the D10, D50, and other measured values ​​of the flaky flakes obtained by coating the glass flakes will not be higher than the corresponding values ​​measured before the coating was formed.

[0030] The D90 of the flaky flakes is not particularly limited, but can be 200 μm or greater. It can be 230 μm or greater, and even 250 μm or greater. However, flakes based on flaky glass with excessively large particle sizes can have a significantly curved shape. From this perspective, the D90 can be 7 mm or less, 5 mm or less, 1 mm or less, 700 μm or less, 500 μm or less, 450 μm or less, and, depending on the situation, 400 μm or less.

[0031] The D90 / D10 ratio is used as an indicator of the narrowness of the particle size distribution. For glittering materials with small particle sizes, such as pearlescent agents, limiting the upper limit of D90 / D10 to a specified value (e.g., 3) or lower can enhance the graininess of the resulting color. However, in the glittering material of the present invention, the need to exclude large flakes is minimal, so D90 / D10 need not be limited to 3 or lower. For example, D90 / D10 can be greater than 3 and less than 6, or even greater than 3 and less than 5. The lower limit of D90 / D10 can be 3.1 or higher, and in some cases, 3.2 or higher.

[0032] The thickness of the scaly flakes is not particularly limited, but may be 0.5 μm or more, 1.0 μm or more, or 7.0 μm or less, 5.0 μm or less.

[0033] Flake glass is a thin sheet of glass, also known as flaky glass. Flake glass is amorphous, and its surface, particularly the main surface, is relatively smoother than a crystalline substrate. Crystalline inorganic flakes such as mica and talc tend to have surface height differences. As crystalline inorganic flakes increase in size, height differences caused by cleavage are unavoidable, especially on the main surface. Using flake glass as a substrate is crucial for eliminating surface height differences, particularly on the main surface.

[0034] Furthermore, resin flakes manufactured by cutting a resin matrix have flat cut surfaces, i.e., end faces. In contrast, flaky inorganic flakes are generally manufactured by crushing or pulverizing an inorganic matrix. Consequently, flaky inorganic flakes have irregular shapes, and their end faces are rarely considered flat. Limiting the proportion of small-particle flakes in flaky inorganic flakes has the effect of reducing the ratio of irregular crushed surfaces to the overall surface area of ​​the flake.

[0035] The height differences and edge faces of the main surface not only scatter light themselves, but also cause light to enter the coating formed thereon at a different angle of incidence than the coating on the smooth main surface. Especially when the coating utilizes light interference to produce color, if the angle of incidence—in other words, the optical path length—is inconsistent, the coating tends to produce a mixed color. Light scattering and the resulting mixed coloration reduce the saturation of the color produced by the glitter material, giving the overall impression of dullness.

[0036] Glass flakes are well known. The composition of glass flakes is not particularly limited. Glass flakes can be made of, for example, various multi-component glasses with silicon dioxide as a main component.

[0037] Reference Figure 1 and Figure 2 A method for producing glass flakes will be described. Figure 1 This is an example of an apparatus for carrying out a method known as blowing. Figure 1 In the apparatus shown, a glass substrate 11 melted in a refractory furnace 12 is expanded into a balloon shape by gas fed from a blowing nozzle 15, forming a hollow glass film 16. Subsequently, the hollow glass film 16 is crushed by a press roller 17 to obtain glass flakes 1. Figure 2 This is an example of an apparatus that implements a method known as the rotation method. Figure 2In the illustrated apparatus, molten glass substrate 11 is poured from nozzle 21 into rotating cup 22. The centrifugal force generated by the rotation of rotating cup 22 causes it to flow radially from the upper edge of cup 22. The flowing substrate 11 passes through annular plates 23, 23 arranged above and below, where it is sucked into the airflow and directed into an annular cyclone-type collector 24. While passing through annular plates 23, 23, the glass cools and solidifies in a thin film form, then breaks into fine fragments, thereby producing glass flakes 1.

[0038] The particle size distribution of the glass flakes can be adjusted, for example, by controlling the crushing or pulverization, and by performing classification as needed. An example of classification is screening classification using a sieve with appropriate mesh openings. Screening classification can be performed using a single sieve or multiple sieves. As an example of the latter, screening classification using two sieves, a first sieve with relatively small mesh openings and a second sieve with relatively large mesh openings, can be exemplified. However, this is not limiting, and the particle size distribution can also be adjusted using a known dry or wet classification device.

[0039] The coating may contain a metal compound. The metal compound may be a nitride, a carbide, or the like, but is preferably an oxide. Examples of metal oxides include titanium oxide, iron oxide, cerium oxide, silicon oxide, aluminum oxide, zinc oxide, zirconium oxide, niobium oxide, and tin oxide. The coating preferably contains a metal oxide, particularly titanium oxide.

[0040] The coating can be composed of a single or multiple layers. Regardless of whether the coating is a single or multilayered film, the present invention is particularly suitable for use in glittering materials having a coating that produces color through light interference. Coatings that produce interference color typically have at least one thin film layer of a metal compound, particularly a metal oxide.

[0041] The coating emitting interference colors may be a multilayer coating including a high refractive index layer having a relatively high refractive index and a low refractive index layer having a relatively low refractive index. The materials constituting these layers are not particularly limited, but the material constituting the high refractive index layer is, for example, at least one selected from the group consisting of titanium oxide, zirconium oxide, iron oxide, cerium oxide, zinc oxide, niobium oxide, and tin oxide, and the material constituting the low refractive index layer is, for example, at least one selected from the group consisting of silicon oxide and aluminum oxide.

[0042] The film thickness can be appropriately adjusted according to the film composition and material to obtain the desired color. The film thickness is usually less than 1 μm, for example, from 20 nm to 300 nm, particularly from 50 nm to 200 nm.

[0043] Titanium oxide has a high refractive index and is suitable for forming films with excellent color rendering. Titanium oxide has three crystal forms: anatase, brookite, and rutile. Anatase and rutile are industrially mass-produced. The preferred crystal form of titanium oxide is rutile. Rutile titanium oxide has low photocatalytic activity, making it less likely to affect substrates such as those containing iridescent pigments, and has the highest refractive index.

[0044] The formation of a rutile titanium oxide film on glass flakes can be carried out by referring to the methods disclosed in, for example, Japanese Patent Application Publication Nos. 2001-31421 and 2003-12962. In these methods, rutile titanium oxide is precipitated on glass flakes in a solution containing a titanium compound such as titanium tetrachloride to form a coating. Rutile titanium oxide can be precipitated on the glass flakes by adding an alkaline compound or alkaline solution to a solution containing the titanium compound at a temperature of 55 to 85°C and a pH of 1.3 or below. Pre-treating the glass flakes by attaching tin or a tin compound to the glass flakes promotes the precipitation of rutile titanium oxide. This method can also be used to form a rutile titanium oxide film on glass flakes pre-attached with gold microparticles. This method allows the formation of a rutile titanium oxide film without the need for heating for crystal transformation.

[0045] The titanium oxide film shows a color corresponding to its thickness. Generally speaking, it shows a yellow color when the thickness is about 100nm, a red color when the thickness is about 130nm, a blue color when the thickness is about 160nm, and a green color when the thickness is about 175nm.

[0046] Furthermore, in the field of pearlescent agents, techniques are known to enhance color saturation, which is often insufficient, by attaching gold particles to the surface of a titanium oxide film and utilizing surface plasmon resonance caused by the gold particles. However, in one embodiment of the present invention, the glittering material does not contain gold particles attached to the film surface, thereby achieving the advantage of highly saturated color development.

[0047] In one embodiment of the present invention, the uniformity of color development from the flaky flakes constituting the glittering material is sufficiently high. Specifically, the standard deviation σ represents the transmission color of 100 flaky flakes in L * a * b * In the color system a * and b * The degree of deviation of each can be suppressed to below 11. The standard deviation σ can be suppressed to below 10.5, below 10, and depending on the situation, it can also be suppressed to below 9, or even below 8.5. The lower limit of the standard deviation σ does not limit the range of σ. For example, a * and b* Can be 3 or more, 4 or more, or even 5 or more, a * and b * Any larger σ can be greater than 7. * and b * The measurement can be performed using a halogen lamp as a light source and a polarizing microscope. The details of the measurement method are described in the Example column.

[0048] By making the hue of each color uniform, the saturation of the color can be increased to an unexpected degree. * It can reach above 30, above 31, and above 32 depending on the situation. * The upper limit of the saturation of the glitter material is not intended to be limited, for example, 37. * , it is possible to make the prescribed coated plate measurement. The details of the measurement method are also described in the Example column.

[0049] The glittering material of the present invention is not limited to cosmetics and can be blended into various compositions for use. Another aspect of the present invention provides a glittering material-containing composition containing the glittering material of the present invention. Examples of the glittering material-containing composition include at least one selected from paints, inks, cosmetics, and resin compositions. Examples of the resin composition include artificial marble molded articles.

[0050] In yet another aspect, the present invention provides a coated article containing a glittering material, comprising a substrate and a coating film containing the glittering material of the present invention formed on the substrate. The coated article containing the glittering material may also be coated paper. In this case, the substrate is paper, but the substrate is not limited to paper and may also be metal, resin, ceramic, or other materials. The coating film may be composed of a composition containing the glittering material of the present invention, or may be formed by coating the composition containing the glittering material of the present invention onto a substrate.

[0051] Specific examples of the glittering material-containing composition itself and the glittering material-containing coated body itself are well known, and therefore, description thereof will be omitted here except for the following description related to cosmetics.

[0052] Examples of cosmetics include facial cosmetics, color cosmetics, and hair care products. The glitter material of this embodiment is particularly suitable for color cosmetics such as eye shadow, nail polish, eyeliner, mascara, lipstick, and highlighter. The form of the cosmetic is not particularly limited, but examples include powder, cake, pen, stick, ointment, liquid, emulsion, and cream.

[0053] Example

[0054] Hereinafter, the present invention will be described in more detail with reference to Examples. First, a specific evaluation method will be described.

[0055] (D10, D50, D90)

[0056] The particle size distribution of a powder of flaky glass having a film formed on the surface was measured using laser diffraction and scattering methods. A Microtrac MT3300EXII manufactured by MicrotracBEL Co., Ltd. was used for the measurement. The particle sizes at which the cumulative volume from the smallest particle size reaches 10%, 50%, and 90% were defined as D10, D50, and D90, respectively.

[0057] (Color evaluation of scaly flakes)

[0058] Using a polarizing microscope, observe and photograph the powder of scaly flakes as the evaluation object. The sample to be observed is prepared as follows: a small amount of powder is taken on a glass slide and clamped with a cover glass, so that the flakes do not overlap as much as possible. As a polarizing microscope, a CX31-P manufactured by OLYMPUS is used. As a light source, a 6V30W halogen lamp is used. The color temperature of this halogen lamp is 3200K. However, the polarizing microscope can be used without inserting either the upper polarizer or the lower polarizer. The photographing is carried out in a state where there are about 100 to 300 scaly flakes in the field of view. In the observation using a polarizing microscope, the transmittance color of the sample is observed.

[0059] The color tone of the transmitted light is evaluated for 100 sheets in the image data obtained by shooting, starting from the largest sheet. However, the evaluation is omitted for sheets whose main surface is greatly tilted or curved, making it impossible to focus. In addition, the measurement is carried out avoiding overlapping scaly sheets. In addition, when different colors of transmitted light are observed on a single sheet, as when interference fringes are observed, the color tone is evaluated for the color with the largest area ratio. The color tone is evaluated by inputting the image data to https: / / www.color-site.com / image_pickers to obtain RGB data, and then converting this data into L * 、a * 、b * . To L * 、a * 、b * The conversion is implemented in https: / / www.webtoolss.com / colorcode2.html. The use of these websites is not required, but it is convenient for quantifying the color tone.

[0060] (Color evaluation of painted panels)

[0061] A coating plate was prepared with a coating film formed with powder containing scaly flakes to be evaluated. The coating composition was prepared by mixing 10% by mass of powder in a transparent acrylic resin (Nippe Acryl "Auto Clear Super" manufactured by Nippon Paint). The coating composition was applied on a white / black background hiding ratio measurement paper and dried to form a coating film. The coating film was applied in a manner to achieve 9 mil (approximately 228.6 μm), and the coating film thickness after drying was 70 to 80 μm. For the black background coated surface, the color was measured using a colorimeter CR-400 (manufactured by Konica Minolta), and the vertically reflected L * 、a * 、b * The light source used is D65. In addition, calculate a * and b * The square root of the sum of the squares of * (Saturation).

[0062] (Visual evaluation of coated panels)

[0063] An LED light source was positioned so that light entered the coating film of the coated plate prepared above at an incident angle of 45°. The reflected light was visually observed from a 45° angle of incidence. If the ratio of the glittering material that perceived interference colors other than the single interference color was less than approximately 30%, the color was judged as "single color." If the ratio of the glittering material that perceived interference colors other than the single interference color was greater than approximately 30%, the color was judged as "mixed color."

[0064] [Production of flake glass]

[0065] Glass flakes were prepared to a predetermined particle size distribution, specifically, to achieve the values ​​shown in Table 1 for D10, D50, and D90, and then classified. Classification was performed using the aforementioned screening method using two sieves. The thickness of the glass flakes was adjusted to 1.3 μm in all cases.

[0066] [Titanium oxide coating]

[0067] To precipitate rutile titanium oxide, the glass flakes with adjusted particle size distribution were treated with tin according to the method described in the aforementioned publication. After the tin treatment, the glass flakes were coated with titanium oxide. The titanium oxide coating was performed by dispersing the glass flake powder in an acidic aqueous solution adjusted to a pH of 1.0 with hydrochloric acid. While stirring the aqueous solution, an aqueous solution of titanium tetrachloride and an aqueous solution of NaOH were added dropwise to maintain a pH of 1.0, causing titanium oxide to precipitate on the surface of the glass flakes. The addition was stopped when the interference color produced by the precipitated titanium oxide reached a predetermined color (red or yellow) when visually observed. The powder was then separated from the aqueous solution, washed, and dried at 180°C. This yielded a powder of scaly glass flakes coated with a rutile titanium oxide film.

[0068] Based on the above, glittering materials were obtained for Examples 1 to 6, Comparative Example 1, and Reference Example. The Reference Example used glass flakes of a size equivalent to that of pearlescent materials. Furthermore, as Comparative Example 2, 7000G manufactured by CQV was prepared. This glittering material is mica coated with titanium oxide and has a size of approximately 60 to 700 μm.

[0069] The particle size distribution and evaluation results of each glitter material are shown in Table 1. From the coating films of Examples 1 to 6, it can be observed that the saturation c * The color development was 32 or higher, and in some cases, 33 or higher, with a single color. In contrast, Comparative Example 1 had many small-diameter flakes, and Comparative Example 2 used a crystalline matrix, resulting in poor color vividness. The Reference Example, which was equivalent to a pearlescent agent, also failed to achieve vivid color development.

[0070]

Table 1

[0071]

[0072] [Eyeshadow production]

[0073] Place the extender pigment and spherical powder from Section A shown in Table 2 in a disposable cup and mix with a spatula. Then, place the mixture in a blender and mix for one minute. Add the coloring pigment and glitter and blend for another 30 seconds. Next, add the ingredients from Section B and blend for another minute. Remove the resulting powder and place an appropriate amount in a mold, compacting it.

[0074]

Table 2

[0075]

[0076] Formula 1 and Formula 2 were applied to the back of the hand and visually evaluated. Formula 1 had a design that emphasized glitter. In contrast, Formula 2 had a relatively small number of glitter particles, and did not achieve a strong sparkle.

Claims

1. A glittering material comprising a plurality of scaly flakes having a D50 of 100 μm or greater, wherein: Each of the plurality of flaky sheets comprises flaky glass and a coating on the flaky glass. For 100 scaly flakes, the transmittance color measured using a halogen lamp as the light source is L * a * b * a in the color system * and b * The standard deviation σ is less than 11. D50 is the particle size at which the cumulative volume from the smallest particle size reaches 50% in the particle size distribution measured by laser diffraction and scattering methods.

2. The glitter material according to claim 1, wherein D10 is 65μm or more, Here, D10 is a particle size at which the cumulative volume from the smaller particle size side in the particle size distribution accounts for 10%.

3. A glittering material comprising a plurality of scaly flakes having a D50 of 100 μm or greater, wherein: Each of the plurality of flaky sheets comprises flaky glass and a coating on the flaky glass. D10 is 65μm or more, D10 and D50 are particle sizes at which the cumulative volume from the smaller particle size reaches 10% and 50%, respectively, in the particle size distribution measured by laser diffraction and scattering methods.

4. The glittering material according to claim 1 or 3, wherein D90 is less than 1mm, Here, D90 is the particle size at which the cumulative volume from the smaller particle size side in the particle size distribution accounts for 90%.

5. The glitter material according to claim 1 or 3, wherein D90 / D10 is higher than 3 and lower than 5.

6. The glittering material according to claim 1 or 3, wherein The coating contains a metal oxide.

7. The glitter material according to claim 6, wherein The metal oxide is titanium oxide.

8. A composition containing a glittering material, comprising the glittering material according to claim 1 or 3. 9 . A glittering material-containing coated body comprising a substrate and a coating film containing the glittering material according to claim 1 or 3 and formed on the substrate.

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