JPH10204318A - Red pigment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a red pigment controlled in the spectral reflectance of the pigment itself and being capable of controlling the spectral reflectance of a cosmetic containing the pigment by using a complex oxide of Ca and Fe. SOLUTION: This pigment comprises a double oxide of the formula: Cax Fey Ox+(3y/2) (wherein x is 0.6-2; and y is 2-3). By controlling the deflection point wavelength (the wavelength at which the first-order differential derivative function of a spectral reflectance curve has a maximum volue or the second- order differential derivative function shows 0) of a spectral reflectance curve obtained by measuring the spectral reflectance of the pigment to 600-640nm, e.g. a cosmetic containing this pigment gives a spectral reflectance curve having a hollow in a wavelength region of 500-620nm. The healthy skin gives a spectral reflectance curve having a hollow at a wavelength of 500-620nm, whereas the darkish skin gives a spectral curve having a shallow hollow at 500-620nm. Therefore, the compound oxide in an amount to give a concentration of 5wt.% is mixed with a body pigment to obtain a red pigment which gives a spectral reflectance curve having a hollow at 500-620nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a red pigment, a pigment composition containing the same, and a cosmetic. More specifically, the present invention relates to a red pigment composed of a composite oxide having a controlled spectral reflection characteristic, excellent dispersibility, and hardly eluting Ca and Fe, a pigment composition containing the same, and a cosmetic.

[0002]

2. Description of the Related Art Organic pigments have various spectral reflection characteristics because of their vivid colors and a wide variety of types, but generally, they have water resistance, solvent resistance, weather resistance, and the like.
Many have poor stability such as heat resistance.

On the other hand, although inorganic pigments are excellent in stability, the types thereof are poor, so that those having various spectral reflection characteristics have not been obtained. Especially in the red pigment, from the viewpoint of stability and safety, at present, only α-Fe ₂ 0 ₃ is used.

However, in the case of using the α-Fe ₂ 0 ₃ is inflection point wavelength in the spectral reflection characteristics obtained are hardly dependent on the shape and particle size, taking material-specific values.
Therefore, even when formulated with α-Fe ₂ 0 ₃ having such properties in cosmetics, there is a disadvantage that the spectral reflection characteristics give only very limited cosmetics.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has a red color which can control the spectral reflection characteristics of the pigment itself, and can further control the spectral reflection characteristics of a cosmetic containing the pigment. It is intended to provide a pigment.

[0006]

The gist of the present invention is as follows: (1) Formula: Ca _x Fe _y O _{x + (3y / 2)} (where x is a number of 0.6 to 2, and y is 2 to 3) Indicates the number of
(2) In a spectral reflection spectrum of a sample obtained by mixing the composite oxide with an extender so that its concentration becomes 5% by weight, a wavelength region of 500 to 620 nm The red pigment according to (1), wherein the red pigment according to the above (1), which has a dent in the spectrum, connects the reflectances at 500 nm and 620 nm with a straight line, and the area formed between the dent and the dent is 300% · nm or more. The composite oxide has an α-Fe ₂ O ₃ crystal phase content of 30% by weight or less and Ca
The red pigment according to the above (1) or (2), which has a content of ₂ Fe ₂ O ₅ crystal phase of 40% by weight or less, (4)
The red pigment according to any one of (1) to (3) above, wherein the composite oxide has a volume average particle size of 0.01 to 50 μm.
(5) The red pigment according to any one of (1) to (4) above, wherein when the composite oxide is suspended in ion-exchanged water, the elution amounts of Ca and Fe are each 500 ppm or less.
A pigment composition comprising the red pigment according to any one of the above (1) to (5), and (7) the above (1) to
(5) A cosmetic comprising the red pigment described in any one of the above.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the red pigment of the present invention has the formula: Ca _x Fe _y O _{x + (3y / 2)} (where x is 0.6
2 and y represents a number of 2 to 3).

When the spectral reflection characteristic of the composite oxide is measured with a spectrophotometer, the inflection point wavelength (the maximum value of the first derivative of the spectral spectrum) in the area where the reflectance of the obtained spectral spectrum changes rapidly is obtained. Or the wavelength at which the second derivative is 0) is controlled in the range of 600 to 640 nm, so that when this pigment is blended in cosmetics or the like, the spectrum is depressed in the wavelength region of 500 to 620 nm in the spectral reflection spectrum. Having.

On the other hand, healthy bare skin generally has a dent in the spectral reflection spectrum in the wavelength region of 500 to 620 nm. Conversely, as the bare skin becomes dull, the spectral reflectance in the wavelength region of 500 to 620 nm increases. It is known that the depression becomes smaller.

In conventional cosmetics, especially in foundations, the spectral dent in the wavelength region of 500 to 620 nm is extremely small. Therefore, when this is applied, the spectral dent of the wavelength of 500 to 620 nm that originally has bare skin is reduced. As a result, the spectral reflection spectrum became similar to that of dull skin, and it was difficult to obtain natural and healthy makeup skin. This is because the red pigment used in conventional cosmetics is red iron oxide (α-Fe ₂ O ₃ ), and the inflection point wavelength of the red iron oxide is around 580 nm.

Therefore, if a pigment whose spectral characteristics, particularly the wavelength of the inflection point is controlled, is used, the wavelength of 500
It is possible to increase the spectral dip at ~ 620 nm. The inflection point wavelength of the red pigment at that time is 600
640-640 nm is preferred, and 620-635 nm is optimal.

The red pigment is, for example, barium sulfate, talc, silica, mica or the like having a refractive index of 1.6 to 1.8.
In a spectral reflection spectrum of a sample mixed with an extender of about 5% by weight so as to have a concentration of about 5% by weight, the spectrum has a depression in the wavelength region of 500 to 620 nm, and 500 nm and 620 nm.
And the area (hereinafter referred to as S500) of the portion formed between the concave portion and the concave portion is 300% · nm or more.

Further, in order to satisfy the above-mentioned spectral reflection characteristics, the molar ratio of Ca to Fe (Ca
/ Fe) is in the range of 0.3 to 0.7, the content of α-Fe ₂ O _{3 in} the composite oxide is 30% by weight or less, and the content of Ca ₂ Fe ₂ O ₅ It is preferred that the ratio be 40% by weight or less. The value of the molar ratio (Ca / Fe) is more preferably 0.4 to 0.55, and α-F
The content of e ₂ O ₃ is 15% by weight or less, and the content of Ca ₂ Fe ₂ O ₅ is 10% by weight or less. This is because α in the red pigment
When the content of -Fe ₂ O ₃ exceeds 30% by weight,
The inflection point wavelength of the obtained spectral reflection characteristic exists in a region of a wavelength shorter than 600 nm, so that a large dent cannot be obtained in the spectrum when blended, and the Ca ₂ Fe ₂ O ₅ content is 40% by weight. This is because, if it exists in excess of%, saturation is lost and lightness is also reduced.

When the red pigment of the present invention is used as a pigment for cosmetics or paints, the volume average particle diameter of the composite oxide is in the range of 0.01 to 50 μm, preferably 0.1 to 50 μm.
It is preferably in the range of 1 to 3 μm. When the red pigment of the present invention is used as a pigment for cosmetics or paints, it can be mixed with known organic color pigments, inorganic color pigments, inorganic extender pigments and the like to form a pigment composition. Examples of such pigments include iron oxide, titanium oxide, zinc oxide, barium sulfate, mica, silica and the like.

Further, when this composite oxide is suspended in ion-exchanged water, Ca and Fe constituting the composite oxide are suspended.
It is preferable that Ca and Fe are hardly eluted, such that the elution amount of each is 500 ppm or less, preferably 100 ppm or less. This is because when the elution amount of Ca ions exceeds 500 ppm, the liquidity becomes highly alkaline, and it becomes impossible to mix it with cosmetics and the like, and furthermore, it stimulates the skin.

As a method for producing the composite oxide used in the present invention, for example, iron oxide powder such as α-Fe ₂ O ₃ , α
-Powders such as iron oxyhydroxide such as FeOOH, β-FeOOH and γ-FeOOH, iron hydroxide represented by Fe (OH) ₃ , and CaO
, Ca (OH) _2, a powder such as CaCO ₃ were mixed thoroughly in a solvent such as ethanol, after removal of the solvent, 800 to 1000 ° C.
And a solid phase reaction method in which firing is performed. There are no particular limitations on the raw materials used in such a method, and the calcined CaO-Fe
Any material can be used as long as a composite oxide of ₂ O ₃ can be produced. In addition to the above method, for example, CaCl 2
₂ , Ca salt such as Ca (NO ₃ ) ₂ and FeCl ₂ , FeCl ₃ , Fe (NO ₃ ) ₃
A mixed aqueous solution of a soluble Fe salt such as NaOH, KOH,
A method of calcining a hydroxide obtained by neutralization with an alkali such as LiOH or NH ₃ can also be employed.

The supply sources of Ca and Fe are not limited to those described above. For example, there is no particular limitation as long as hydroxides are generated by neutralization. In addition, as a precipitant,
An organic acid such as oxalic acid or citric acid can be used, but is not particularly limited as long as the resulting precipitate is calcined to produce a CaO—Fe ₂ O ₃ composite oxide. Further, it can also be obtained by a method that does not require calcination by a hydrothermal reaction method, or by a gas phase method such as a spray pyrolysis method. Further, in order to make α-Fe ₂ O ₃ and Ca ₂ Fe ₂ O ₅ exist, in addition to adjusting the charged molar ratio of Ca and Fe, those that form a compound with Ca as a third component, for example, SiO ₂ or By adding ZrO ₂ etc. to generate Ca ₂ SiO ₄ and CaZrO ₃ , α-F
It is also possible to adjust the abundance of e ₂ O ₃ .

The formula thus obtained: Ca _x Fe _y
A red pigment composed of a composite oxide represented by O _{x + (3y / 2)} (where x is a number from 0.6 to 2 and y is a number from 2 to 3) controls spectral reflection characteristics, Since it is fine particles, has excellent dispersibility, hardly dissolves Ca and Fe, and has crystallinity, it has excellent weather resistance and fading resistance.

Therefore, the red pigment of the present invention can be used by blending it in various pigment compositions, cosmetics and the like in an appropriate amount.

[0020]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to only these examples.

Example 1 The raw material powder Ca was adjusted so that the molar ratio of Ca / Fe became 0.5.
Both were weighed at a ratio of 29.425 parts by weight of (OH) _{2 and} 70.575 parts by weight of α-FeOOH to make a total amount of 100 g. Put this in a ZrO ₂ ball mill pot with a capacity of 500 ml,
Mixing was performed for 12 hours using 1200 g of ZrO ₂ balls and 150 g of ethanol as a solvent.

Thereafter, the slurry and the balls were separated, and ethanol in the slurry was distilled off to obtain a homogeneous mixed powder of Ca (OH) ₂ -α-FeOOH. This was fired in an electric furnace at 1000 ° C. for 3 hours to obtain a red pigment.

As a result of X-ray diffraction analysis, the obtained red pigment was a single phase of CaFe ₂ O ₄ .

When the optical properties of the obtained composition were evaluated according to the following methods, the inflection point wavelength was at 625 nm and the S500 was 381.0% · nm. The volume average particle size was measured by a laser scattering particle size distribution analyzer (model LA-700) manufactured by Horiba, Ltd.
It was 35 μm, and the amounts of Ca and Fe eluted were determined according to the methods described below. The results were 50 ppm and 2 ppm, respectively.

(1) Measurement method of optical characteristics (spectral reflection characteristics) 1.0 g of a sample powder (red pigment) was packed in a cell for measuring powder, and a spectrophotometer (Corp. (U-4000, manufactured by Hitachi, Ltd.), the spectral reflection spectrum in the visible wavelength range of 380 to 780 nm was measured, and the obtained spectrum was determined to be 0 when the maximum value of the first derivative or the second derivative was 0. Is obtained as an inflection point wavelength.

Next, in a spectral reflection spectrum of a sample obtained by mixing with a white pigment (barium sulfate) so that the concentration of the red pigment is 5% by weight, in a wavelength region of 500 to 620 nm, wavelengths of 500 nm and 620 nm are obtained. Are connected by a straight line, and the area (S500) of the portion formed between the reflectance and the depression of the spectrum is obtained.

(2) Method for measuring elution amount of Ca and Fe 1.0 g of a sample powder (red pigment) was ion-exchanged with water (water temperature: 20).
C) suspended in 100 ml and stirred for 12 hours, and then the powder and the solution were separated by a filter.
The elution amount of Fe is measured by plasma emission analysis (ICP).

Example 2 The same operation as in Example 1 was carried out, except that the molar ratio of Ca / Fe was adjusted to 0.4.
As a result, the inflection point wavelength of the obtained red pigment was 623.5 nm,
X-ray diffraction analysis of the obtained red pigment revealed that an α-Fe ₂ O ₃ phase was formed in addition to the CaFe ₂ O ₄ phase. Furthermore, the same analysis quantified the abundance ratio of CaFe ₂ O ₄ and α-Fe ₂ O ₃ , and as a result, the α-Fe ₂ O ₃ phase was replaced with the CaFe ₂ O ₄ phase.
The content was 10% by weight. The volume average particle size is 1.54
μm, the elution amounts of Ca and Fe were 48 ppm and 2 ppm, respectively.
Met.

Example 3 The same operation as in Example 1 was performed, except that the Ca / Fe molar ratio was adjusted to 0.6.
As a result, the inflection point wavelength of the obtained red pigment was 627 nm,
X-ray diffraction analysis of the resulting red pigment revealed that a Ca ₂ Fe ₂ O ₅ phase was formed in addition to the CaFe ₂ O ₄ phase. At this time, the amount of Ca ₂ Fe ₂ O ₅ mixed was 22% by weight.

The volume average particle diameter was 1.36 μm, and the elution amounts of Ca and Fe were 89 ppm and 3 ppm, respectively.

Example 4 1 liter of an aqueous solution containing 0.8 mol of NaOH and 1 liter of an aqueous solution containing 0.1 mol of CaCl ₂ and 0.2 mol of FeCl ₃ (0.5 mole ratio of Ca / Fe) were stirred at room temperature. Was dropped at a rate of 10 ml / min using a metering pump.

After the completion of the dropwise addition, the pH was 12.5. The mixed hydroxide of Ca and Fe obtained here was thoroughly washed with water, dried, and fired at 900 ° C. for 3 hours in an electric furnace.

As a result, when the obtained red pigment was analyzed by X-ray diffraction, it was found to be a CaFe ₂ O ₄ single phase. When the inflection point wavelength was measured, the inflection point wavelength was 623 nm.
S500 was 325.4% · nm, and the average particle size was 1.12 μm.
The elution amounts of m, Ca and Fe were 34 ppm and 3 ppm, respectively.

Example 5 In Example 4, the sintering temperature and the time were set at 800 ° C.
The same operation as in Example 4 was performed except that the time was set to 3 hours. As a result, X-ray diffraction analysis revealed that the composition of the obtained red pigment was CaFe ₂ O ₄ . When the inflection point wavelength was measured, the inflection point wavelength was 608.5 nm. S500 is 431.6% · nm, and the average particle size is 0.78
The elution amounts of μm, Ca and Fe were 97 ppm and 5 ppm, respectively.

Example 6 The same operation as in Example 4 was performed, except that the molar ratio of Ca / Fe was changed to 0.4. As a result, X
According to X-ray diffraction analysis, α-Fe ₂ O ₃ phase in addition to CaFe ₂ O ₄ phase
It was confirmed that a red pigment having a content of about 10% by weight was obtained. When the inflection point wavelength was measured, the inflection point wavelength was 618.5 nm. S500 is 400.6% · nm,
The average particle diameter was 1.32 μm, and the elution amounts of Ca and Fe were 26
ppm and 2 ppm.

Example 7 One liter of an aqueous solution containing 0.3 mol of (COOH) ₂ was heated to 100 ° C. and stirred, and an aqueous solution containing 0.1 mol of CaCl ₂ and 0.2 mol of FeCl ₂ (value of the molar ratio of Ca / Fe: 0. 5) One liter was added dropwise over 1 minute using a dropping funnel, and aging was performed for 1 hour with stirring at the same temperature. Then, the generated Ca and
The oxalate of Fe was filtered off, washed with water and dried. The dried powder was fired in an electric furnace at 1000 ° C. for 1 hour. The obtained red pigment can be identified as a single phase of CaFe ₂ O ₄ by X-ray diffraction analysis. Its inflection point wavelength is 625 nm, and S500 is 413.7% ·
nm. In addition, the elution amounts of Ca and Fe are 6 ppm each.
And 3 ppm.

Example 8 The same operation as in Example 7 was performed, except that the molar ratio of Ca / Fe was changed to 0.4. as a result,
X-ray diffraction analysis showed that a red pigment containing 8% by weight of an α-Fe ₂ O ₃ phase in addition to the CaFe ₂ O ₄ phase was obtained. The inflection point wavelength of the obtained red pigment is 622.5 nm, and S500 is 430.2% · n.
m, and the average particle size was 1.25 μm. Further, the elution amounts of Ca and Fe at this time were 56 ppm and 2 ppm, respectively.

Example 9 The same operation as in Example 1 was performed, except that Ca raw material and Fe raw material were changed to CaCO ₃ and α-Fe ₂ O ₃ , respectively. As a result, according to the X-ray diffraction analysis, the obtained red pigment was a single phase of CaFe ₂ O ₄ . The inflection point wavelength is 627.
5nm, S500 is 300.5% · nm, average particle size is 1.
It was 56 μm. Further, the elution amounts of Ca and Fe at this time were 52 ppm and 2 ppm, respectively.

Example 10 The same operation as in Example 9 was performed, except that the molar ratio of Ca / Fe was changed to 0.4. as a result,
According to X-ray diffraction analysis, the obtained red pigment contained 12% by weight of α-Fe ₂ O ₃ phase in addition to the CaFe ₂ O ₄ phase. The inflection point wavelength is 616.5 nm, and S500 is 356.6%
nm, and the average particle size was 1.32 μm. Further, the elution amounts of Ca and Fe at this time were 46 ppm and 1 ppm, respectively.

Example 11 10 g of the red pigment obtained in Example 1 and powder 10 uniformly mixed with mica so that the pigment concentration was 1% by weight.
g was molded into a disc having a diameter of 20 mm, measured with the spectrophotometer, exposed under a fluorescent lamp (illuminance: about 500 lux) at room temperature for 2 weeks, and then measured in the same manner as described above. The color change rate ΔE before and after exposure was determined. As a result, the color change rate Δ
E was 0.09 and 0.8, respectively, and no color change or fading was observed.

Comparative Example 1 Analysis of a commercially available α-Fe ₂ O ₃ for cosmetics revealed that the inflection point wavelength was 585.5 nm, that of S500 was 584.5% · nm,
The average particle size was 0.34 μm.

COMPARATIVE EXAMPLE 2 One liter of an aqueous solution containing 0.26 mol of (COOH) ₂ was heated and stirred at 100 ° C., and an aqueous solution containing 0.06 mol of CaCl ₂ and 0.2 mol of FeCl ₂ (value of molar ratio of Ca / Fe: 0. 3) One liter was added dropwise over 1 minute using a dropping funnel, and aging was performed for 1 hour with stirring at the same temperature. Then, the generated Ca and
The oxalate of Fe was filtered off, washed with water and dried. The dried powder was fired in an electric furnace at 1000 ° C. for 1 hour. According to X-ray diffraction analysis, the obtained composition was found to have α-F in addition to the CaFe ₂ O ₄ phase.
It could be identified as containing 47% by weight of e ₂ O ₃ , and its inflection point wavelength was 595 nm and S500 was 553.1% · nm. The elution amounts of Ca and Fe were 31 ppm and 2 ppm, respectively.

Comparative Example 3 The same operation as in Example 1 was performed, except that the molar ratio of Ca / Fe was changed to 0.7. as a result,
The inflection point wavelength was 628.5 nm and S500 was 274.3% .nm. The obtained red pigment was subjected to X-ray diffraction analysis. As a result, in addition to the CaFe ₂ O ₄ phase, 24% by weight of Ca ₂ Fe ₂ O ₅ and α-Fe ₂ 10% by weight of O ₃ had formed. The volume average particle size was 1.35 μm, and the elution amounts of Ca and Fe were 123 ppm and 3 ppm, respectively.

Comparative Example 4 Red 20 of an organic pigment having an inflection point wavelength at 620 nm
With respect to No. 2, 10 g of the same pigment and 10 g of a powder obtained by uniformly mixing the pigment with mica so as to be 1% by weight were 20 m in length.
It was shaped into a disk of mφ, and the color change rate ΔE was determined in the same manner as in Example 14. As a result, the color change rates ΔE were 1.7 and 2.2, respectively, and discoloration was clearly observed.

[0045]

According to the present invention, there is provided a red pigment capable of controlling the spectral reflection characteristics of the pigment itself and controlling the spectral reflection characteristics of a cosmetic containing the pigment.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Sakaguchi 1334 Minato, Wakayama

Claims (7)

[Claims] 1. Formula: Ca _x Fe _y O _{x + (3y / 2)} (where x is a number from 0.6 to 2, and y is a number from 2 to 3)
A red pigment comprising a composite oxide represented by 2. A spectral reflection spectrum of a sample obtained by mixing a composite oxide with an extender so that the concentration of the composite oxide is 5% by weight has a depression in the wavelength region of 500 to 620 nm, And 620nm reflectance are connected by a straight line, and the area of the area formed between
The red pigment according to claim 1, which has a diameter of at least nm. 3. The composite oxide has an α-Fe ₂ O ₃ crystal phase content of 30% by weight or less and a Ca ₂ Fe ₂ O ₅ crystal phase content of 40% by weight or less.
3. The red pigment according to claim 1, which has a weight percentage of not more than 3. 4. The composite oxide has a volume average particle diameter of 0.01 to 50 μm.
The red pigment according to any one of claims 1 to 3, which has m. 5. The red pigment according to claim 1, wherein when the composite oxide is suspended in ion-exchanged water, the amounts of Ca and Fe eluted are each 500 ppm or less. 6. A pigment composition comprising the red pigment according to claim 1. 7. A cosmetic comprising the red pigment according to claim 1.