Lamina and a cosmetic comprising the same

A lamina having an excellent capacity of scattering ultraviolet rays comprising a laminar substance as a matrix and a finely divided metal or metal compound dispersed therein, wherein the difference in refractive index between the laminar substance and the finely divided metal or metal compound is not less than 0.1, and a cosmetic comprising the same as a UV screener.

The present invention relates to a lamina having an excellent capacity of 
scattering ultraviolet rays comprising a laminar substance as a matrix and 
a finely divided metal or metal compound dispersed therein and to a 
cosmetic comprising the same as a UV screener. 
UV screeners are for screening ultraviolet rays by scattering or absorbing 
ultraviolet rays. For this purpose, organic compounds have been used such 
as salycilic acid, p-aminobenzoic acid, cinnamic acid, esters thereof and 
benzophenones and powder of metal oxides such as titania, zinc oxide, iron 
oxide and the like. It has also been known that the UV screening ability 
of the powder of metal oxides reaches a maximum when the ratio of the 
diameter of the powder to the wavelength of rays is 1/2. 
The powder of metal oxides is also used as oxidation catalysts. The known 
methods for preparing the same include (1) a method comprising adding 
aqueous ammonia or urea to metal chloride or metal sulfate to hydrolyze 
the same and calcining the resulting hydroxide and (2) a method comprising 
mixing TiO.sub.2 .multidot.nH.sub.2 O and Zn(OH).sub.2 obtained by 
hydrolysis of titanium isopropoxide and zinc nitrate, respectively, and 
calcining the mixture ["Catalyst", Vol. 19, No. 5, pp. 350-2, published by 
Catalysis Society of Japan]. 
A method has also been known which comprises hydrolyzing a mixture of a 
silicon alkoxide and a titanium alkoxide and calcining the resulting 
hydrolysate, and it has also been known to use the resulting product as an 
additive for a cosmetic having a UV screening ability [Japanese Patent 
Application Kokai (Laid-Open) No. 227,813/84]. 
In addition, there has been known a method for preparing finely divided 
particles by oxidatively decomposing or hydrolyzing the sublimate of 
titanium chloride with oxygen or steam, respectively. The finely divided 
particles thus obtained have a particle diameter of about 0.002-0.05 
.mu.m. 
Zinc oxide can be prepared by the vapor phase oxidation of vapor of 
metallic zinc, and the finely divided particles thus obtained have a 
particle diameter of about 0.05-0.5 .mu.m. 
The powder of zinc oxide, iron oxide or titania obtained according to such 
methods has an excellent UV screening ability when it is in the form of 
finely divided particles. However, such a powder has a problem that the 
finely divided particles tend to agglomerate, so that when they are 
incorporated with cosmetics, paints and the like, the latter are inferior 
in spreading property and in feel when used. 
Since these finely divided metal oxides have a large surface area and a 
high surface activity, they have a catalytic activity for oxidation and, 
in some applications, cause coexisting organic substances to deteriorate. 
Under such circumstances, the present inventors have made extensive 
research on UV screeners having not only an excellent capacity of 
scattering ultraviolet rays, but also an excellent dispersibility in a 
medium giving cosmetics and the like a good feeling in use by 
incorporating the screeners thereinto and causing no deterioration of 
coexisting organic substances in cosmetics and the like. 
It is an object of this invention to provide a lamina having an excellent 
capacity of scattering ultraviolet rays. 
It is another object to provide a lamina having a good dispersibility in 
cosmetics, paints and the like. 
It is still another object to provide cosmetics having incorporated 
thereinto the lamina and a good feeling in use in respect of spreading 
property and the like. 
Other objects and advantages of this invention will become apparent from 
the following description. 
According to this invention, there is provided a lamina comprising a 
laminar substance as a matrix and a finely divided metal or metal compound 
dispersed therein, wherein the difference in refractive index between the 
laminar substance and the finely divided metal or metal compound is not 
less than 0.1. 
This invention also provides a cosmetic comprising the above lamina. 
The lamina of the present invention is superior in ability to screen 
ultraviolet rays, especially those having a wavelength of not more than 
400 nm, and dispersability in resins or vehicles compared with 
conventional metal oxide powders. Therefore, when the lamina is 
incorporated into cosmetics, paints, films for agriculture and the like, a 
good feel is given in use of them in respect of spreading property. 
Moreover, the lamina causes no deterioration of coexisting organic 
substances. Hence, the lamina of the present invention can be used as a UV 
screener not only in cosmetic but also in paints, films for agriculture 
and the like, and has a very great industrial value. 
In the accompanying drawings, FIGS. 1, 2 and 3 are graphs showing spectral 
transmittances of the laminae of the present invention and commercially 
available, finely divided metal oxides at a wavelength ranging from 300 to 
600 nm. 
The laminar substance used as a matrix in the lamina of the present 
invention includes bivalent or higher polyvalent metals; oxides, nitrides, 
carbides and hydroxides of the metals; hydrolysates of metal chlorides; 
partial hydrolysates of organometallic compounds such as metal alkoxides, 
metal chelate compounds and metal salts of organic acids; inorganic and 
organic compounds of a high molecular weight; and the like. 
Specifically, the metals include magnesium, zinc, aluminum, indium, 
silicon, tin, titanium, zirconium, chromium, molybdenum, tungsten, iron, 
cobalt and nickel and the like; the oxides, nitrides, carbides and 
hydroxides of metals include those of these metals; the metal chlorides 
include partial hydrolysates of silicon tetrachloride, titanium 
tetrachloride, zirconium tetrachloride and the like; the partial 
hydrolysates of metal alkoxides include partial hydrolysates of magnesium 
diethoxide, magnesium diisopropoxide, zinc diethoxide, zinc 
diisopropoxide, aluminum triisopropoxide, aluminum tributoxide, indium 
triethoxide, indium trioctoxide, tetraethoxy silane, tetrabutoxy silane, 
tin tetraethoxide, tin tetraoctoxide, titanium tetraethoxide, titanium 
tetraisopropoxide, zirconium tetraethoxide, zirconium tetrapentoxide, 
chromium triethoxide, chromium tributoxide, molybdenum hexaethoxide, 
molybdenum hexabutoxide, tungsten hexaisopropoxide, iron diisopropoxide, 
iron tributoxide, cobalt dibutoxide, cobalt diisopropoxide, nickel 
diisopropoxide, nickel dibutoxide and the like; the partial hydrolysates 
of metal chelate compounds include acetyl acetonates of magnesium, zinc, 
aluminum, indium, silicon, tin, titanium, zirconium, chromium, moyybdenum, 
tungsten, iron, cobalt, nickel and the like; the partial hydrolysates of 
organic acids include aluminum acetate, indium formate, silicon acetate, 
tin acetate, titanium formate, titanium acetate, zirconium propionate and 
the like; the inorganic compounds of a high molecular weight include water 
glass, aluminum phosphate solution, zirconium phosphate, phosphazenes and 
the like; the organic compounds of a high molecular weight include 
polyethylene, polypropylene, polystyrene, polyesters, polymethyl 
methacrylate, polyvinyl chloride, ethyl cellulose, methyl cellulose, 
nitrocellulose, polyvinyl alcohol, polyimides, epoxy resins, phenol resins 
and the like. 
The finely divided metal or metal compound dispersed in the laminar 
substance includes bivalent or higher polyvalent metals; oxides, nitrides, 
carbides and hydroxides of the metals; hydrolysates of metal chlorides; 
partial hydrolysates of organometallic compounds such as metal alkoxides, 
metal chelate compounds, metal salts of organic acids and the like; metal 
sulfates; and the like. Preferred are bivalent or higher polyvalent metals 
and oxides, nitrides, carbides and hydroxides of the metals. Oxides of the 
metals are more preferable. 
Specifically, the metals include magnesium, zinc, aluminum, indium, 
silicon, tin, titanium, zirconium, chromium, molybdenum, tungsten, iron, 
cobalt, nickel and the like; the oxides, nitrides, carbides and hydroxides 
of the metals include oxides, nitrides, carbides and hydroxides of these 
metals; the hydrolysates of metal chlorides include silicon tetrachloride, 
titanium tetrachloride, zirconium tetrachloride and the like; the partial 
hydrolysates of metal alkoxides include partial hydrolysates of magnesium 
diethoxide, magnesium diisopropoxide, zinc diethoxide, zinc 
diisopropoxide, aluminum triisopropoxide, aluminum triisobutoxide, indium 
triethoxide, indium trioctoxide, tetraethoxy silane, tetrabutoxy silane, 
tin tetraethoxide, tin tetraoctoxide, titanium tetraethoxide, titanium 
tetraisopropoxide, zirconium tetraethoxide, zirconium tetrapentoxide, 
chromium triethoxide, chromium tributoxide, molybdenum hexaethoxide, 
molybdenum hexabutoxide, tungsten hexaisopropoxide, iron diisopropoxide, 
iron tributoxide, cobalt dibutoxide, cobalt diisopropoxide, nickel 
diisopropoxide, nickel dibutoxide and the like; the partial hydrolysates 
of metal chelate compounds include partial hydrolysates of acetylacetonate 
of magnesium, zinc, aluminum, indium, silicon, tin, titanium, zirconium, 
chromium, molybdenum, tungsten, iron, cobalt, nickel and the like; the 
partial hydrolysates of metal carboxylates include partial hydrolysates of 
aluminum acetate, indium formate, silicon acetate, tin acetate, titanium 
formate, titanium acetate, zirconium propionate and the like. 
As the finely divided metal or metal compound, the following may preferably 
be used: commercially available metallic fine powders of nickel, silver, 
copper, aluminum, gold, iron and the like (for example, those mfd. by 
Shinkuu Yakin Co., Ltd. or Mitsui Mining & Smelting Co., Ltd.); finely 
divided particles of iron oxide, silica, alumina and titania (for example, 
those mfd. by Okamura Seiyu Co., Ltd., Nippon Aerosil Co., Ltd. or 
Sumitomo Chemical Co., Ltd.); finely divided particles of silicon carbide 
(for example, those mfd. by Showa Denko K.K.) and finely divided particles 
of silicon nitride (for example, those mfd. by Ube Industries, Ltd.). 
The metal hydroxides may be magnesium hydroxide, barium hydroxide, iron 
hydroxide, aluminum hydroxide and the like which are easily obtained by a 
known procedure such as addition of an alkali to an aqueous solution of a 
corresponding metal salt. 
The metal sulfate can be obtained by neutralization of an aqueous solution 
of a corresponding metal hydroxide or salt with sulfuric acid. It may be, 
for example, superfinely divided barium sulfate obtained by the reaction 
of an aqueous solution of barium hydroxide with sulfuric acid. 
Partial hydrolysates of the above-mentioned metal alkoxides or modification 
products of said metal alkoxides with organic acids can also be used as 
the finely divided metal compound in the present invention. For example, 
finely divided particles of monodisperse can be obtained by adding a 
proper amount of water and ammonia to an ethanol solution of tetraethoxy 
silane. Finely divided particles can also be obtained by blowing into the 
air an alcoholic solution containing aluminum propoxide and a proper 
amount of stearic acid from a nozzle or the like. 
The average particle diameter of the finely divided metal or metal compound 
used in the present invention is preferably about 0.005-0.5 .mu.m, more 
preferably about 0.008-0.1 .mu.m. When the average particle diameter is 
larger than 0.5 .mu.m, it tends to be difficult to uniformly disperse the 
metal or metal compound in the laminar substance. And the capacity of 
scattering ultraviolet rays tends to be reduced since the average particle 
diameter becomes larger than the wavelength. On the other hand, when the 
average particle diameter is smaller than 0.005 .mu.m, the difference in 
particle size between the finely divided particles and the matrix tends to 
be insignificant. 
Any known method can be utilized for adding the finely divided metal or 
metal compound to, mixing the same with and dispersing the same in the 
laminar substance as the matrix as far as it can uniformly disperse the 
finely divided metal or metal compound in the laminar substance. A laminar 
substance comprising a metal oxide as the matrix can be obtained by the 
following method described in U.S. Pat. No. 2,941,895 or Japanese Patent 
Application No. 176,906/85. Combining the above-mentioned methods, we can 
obtain a laminar comprising a metal oxide as a matrix and a finely divided 
metal or metal compound dispersed therein: After dispersing a finely 
divided metal or metal compound in a metal alkoxide solution, the 
dispersion is coated onto a smooth-surface of a substrate. Thereafter, the 
resulting coating film is subjected to hydrolysis with water or steam to 
obtain a lamina in which a finely divided metal or metal compound 
dispersed in a partial hydrolysate of the metal alkoxide as a matrix, and 
the lamina is exfoliated by a scraper or the like and then calcined in the 
air. When the calcination is effected in a reductive atmosphere such as in 
the presence of carbon or the like, there is obtained a lamina comprising 
a matrix composed mainly of metal carbide and a finely divided metal or 
metal compound dispersed therein. Alternatively, when the calcination is 
effected in a nitrogen atmosphere in the presence of carbon, there is 
obtained a lamina comprising a matrix composed mainly of metal nitride and 
a finely divided metal or metal compound dispersed therein. 
A lamina comprising titania as the matrix and a finely divided metal or 
metal compound dispersed therein can be obtained by dispersing a finely 
divided metal or metal compound in an aqueous solution of titanium sulfate 
and making a laminar substance by the method described in U.S. Pat. No. 
3,018,186. 
Moreover, a lamina comprising titanium carbide or titanium nitride as the 
matrix and a finely divided metal or metal compound can be obtained by 
changing the atmosphere in the calcination in the above-mentioned method. 
Similarly, various laminae comprising as the matrix an organic compound of 
a high molecular weight such as polyethylene, polypropylene, polystyrene, 
a polyester, polymethyl methacrylate, polyvinyl chloride, ethyl cellulose, 
methyl cellulose, nitrocellulose, polyvinyl alcohol, a polyimide or the 
like and a finely divided metal or metal compound dispersed therein can be 
obtained by kneading the finely divided metal or metal compound with the 
organic compound by means of a roll mill or the like or by laminating a 
dispersion of the finely divided metal or metal compound in a solvent 
solution of the above-mentioned organic compound by means of a known drum 
flaker or by the method disclosed in Japanese Patent Application No. 
82,486/86. 
Also, according to the method described in Japanese Patent Application No. 
82,486/86, a dispersion of the finely divided metal or metal compound in a 
solution of an inorganic compound of a high molecular weight such as water 
glass or aluminum phosphate solution can be laminated. 
In such cases, the resulting lamina may be calcined in order to improve the 
stability in the air. 
When the matrix is a metal oxide, a metal carbide, the above-mentioned 
method comprising dispersing the finely divided metal or metal compound in 
a metal alkoxide solution and then hydrolyzing the metal alkoxide is most 
preferred in view of uniform quality and productivity. 
Since there is a distribution in size and thickness of the lamina, the size 
and thickness are indicated by average size and thickness which are 
defined as the mean values of the respective values "(maximum length of 
lamina minimum length of lamina)/2" and "(maximum thickness of 
lamina+minimum thickness)/2" of 100 laminae. 
Average thickness and size of the lamina of the present invention are not 
critical. However, the average size of the lamina is preferably about 
1-500 .mu.m, more preferably 3-100 .mu.m. When the average size of the 
lamina is less than about 1 .mu.m, it becomes difficult to maintain the 
form of a lamina. On the other hand, when the average size of the lamina 
is more than 500 .mu.m, the lamina becomes easy to break. 
The average thickness of the lamina is preferably about 0.1-5 .mu.m, more 
preferably 0.2-2 .mu.m. When the average thickness is less than about 0.1 
.mu.m, the mechanical strength of the lamina tends to become so weak that 
the lamina cannot be used in practice. On the other hand, when the average 
thickness of the lamina is more than about 5 .mu.m, the adhesiveness to 
skin and feel in use of cosmetics comprising the lamina tend to be 
inferior. 
The aspect ratio of the lamina defined as follows is not critical though it 
is preferably 3-100: 
##EQU1## 
When the aspect ratio is less than 3, the spreading property of the 
cosmetics comprising the lamina tends to become low. On the other hand, 
when the aspect ratio is more than 100, the lamina tends to be broken 
mechanically. 
In order to obtain or adjust the size of the lamina to the specific value, 
a known method may be adopted such as grinding the lamina obtained above 
by a dry ball mill, a wet ball mill, an oscillating mill, a roll mill or a 
Jet mill, or one or more classification methods selected from wet 
classification methods using oscillation screen such as gyroshifter or 
hammer screen; spiral classificator; and hydraulic power classificator, 
dry classification methods using dynamic or centrifugal air classificator 
and ore floatation methods (see, e.g. "Handbook of Particle Technology", 
edited by Kouichi Iitani, published by Asakura Shoten). 
In general, the greater the difference in refractive index between the 
matrix and the finely divided metal or metal compound dispersed therein, 
the greater the UV screening ability due to the capacity of scattering 
ultraviolet rays. Therefore, the difference in refractive index between 
the matrix and the finely divided metal or metal compound dispersed 
therein is preferably 0.1 or more, more preferably 0.3 or more. When it is 
less than 0.1, the capacity of scattering ultraviolet rays and the UV 
screening ability tend to become insufficient. 
For example, in the case where an organic compound of a high molecular 
weight or silica having a refractive index of 1.4-1.5 is used as the 
matrix, it is preferable to use alumina having a refractive index of 1.76 
as the finely divided metal or metal compound, more preferably zinc oxide 
having a refractive index of 2.0 or titania having a refractive index of 
2.5, whereby the capacity of scattering ultraviolet rays and UV screening 
ability are highly improved. 
On the contrary, in the case where zinc oxide, titania or the like having a 
high refractive index is used as the matrix, it is preferable to use 
silica, alumina or the like having a low refractive index as the finely 
divided metal or metal compound. 
A composite compound comprising one of the above-mentioned oxides, carbides 
or nitrides may be useful since the refractive index can be varied 
dependng upon the mixing ratio. For example, a composite oxide consisting 
of silica and alumina at a weight ratio of 90:10 has a refractive index of 
about 1.7, whereas that at a weight ratio of 80:20 has a refractive index 
of about 1.65. A composite oxide consisting of titania and silica at a 
weight ratio of 50:50 has a refractive index of about 1.8, whereas that at 
a weight ratio of 25:75 has a refractive index of about 1.6. 
The combination and proportion of the matrix and the finely divided metal 
or metal compound may be varied depending upon the size thereof or the 
purpose of use. For example, in the case of use as a UV screener where the 
transparency is important, it is preferable to disperse uniformly in a 
laminar substance having a low refractive index as a matrix a superfinely 
divided metal or metal compound having an average particle diameter of 0.1 
.mu.m or less and a high refractive index in an amount as small as 
possible. However, when the transparency is not important, the average 
particle diameter and proportion of the finely divided metal or metal 
compound are not so restrictive. 
The laminar substance to be used as a matrix in the lamina of the present 
invention, and the finely divided metal or metal compound to be dispersed 
in the laminar substance are selected depending upon the purpose of use of 
the lamina: For example, where the heat resistance at a temperature of 
200.degree. C. or more is required, a metal oxide, a metal nitride, a 
metal carbide or an inorganic compound of a high molecular weight is 
suitable as the matrix. On the other hand, when the heat resistance at a 
temperature of not more than 100.degree. C. is sufficient, conventional 
organic compounds of a high molecular weight is usable as the matrix and 
less expensive. 
When the volume fraction of the finely divided metal or metal compound to 
be dispersed in the matrix exceeds 50%, the finely divided metal or metal 
compound serves as the matrix and the resulting lamina comes to have the 
properties of the finely divided metal or metal compound as a matrix. 
Therefore, if it is possible to form the matrix using the constituent of 
the finely divided metal or metal compound and form the finely divided 
particles using the constituent of the matrix, it may be, in some cases, 
easier to prepare a lamina by such a method. 
However, generally, it is not always possible to exchange the constituent 
of the laminar substance and the finely divided particle. In view of ease 
of production, the volume fraction of the finely divided metal or metal 
compound is preferably about 0.1 to about 50%, more preferably about 1 to 
about 30% in view of practical use. 
When the volume fraction of the finely divided metal or metal compound is 
too large, the properties of the resulting lamina becomes governed by the 
properties of the finely divided metal or metal compound, and hence, the 
combination effect becomes insignificant and the production of the lamina 
becomes difficult. On the contrary, when the volume fraction of the finely 
divided metal or metal compound is too small, the properties of the lamina 
tends to become substantially the same as those of the matrix, and the 
scattering of ultraviolet rays, for example, tends to be insufficient. 
If a colored lamina is intended, colored finely divided metal or metal 
compound and/or colored laminar substance may be used. Especially, colored 
finely divided metal or metal compound should be used. For example, when 
red pigment such as iron oxide or the like is used, the lamina can be 
reded, when Green No. 2, chromium oxide or the like is used, the lamina 
can be greened and when molybdenum oxide or the like is used, the lamina 
can be blued. 
The lamina thus obtained can be contained in various make-up and basic 
cosmetics such as day cream, powder foundation, face powder, lip stick, 
eye shadow and the like comprising UV screener so as to screen skin from 
harmful ultraviolet rays. 
The content of the lamina of the present invention in the cosmetics can be 
varied depending upon the type of the cosmetic. However, it is, in 
general, preferably about 0.5 to about 70% by weight, more preferably 
about 2 to about 40% by weight, based on the total weight of the cosmetic. 
When the content of the lamina is less than 0.5% by weight, the cosmetic 
tends to become low in capacity of screening ultraviolet rays. On the 
other hand, when the content exceeds 70% by weight, the feel in use of the 
cosmetic such as soft and moist touch or the like becomes unsatisfactory. 
In order to improve the capacity of screening ultraviolet rays, known UV 
screeners may be used, such as derivatives of salycilic acid, benzoic 
acid, cinnamic acid and benzophenone; titania; zinc oxide; calcium carbide 
and the like, together with the lamina of the present invention. 
Before blending the lamina of the present invention with the cosmetic, the 
lamina can be subjected to a surface treatment such as a surface coating 
treatment with conventional fats and oils, a treatment with surface active 
agents or a treatment with a metal soap such as zinc stearate or the like, 
which is usually used for the purpose of enhancing the dispersibility and 
service characteristics. 
The lamina of the present invention can be blended with cosmetics by a 
known blending method such as by means of a Henschel mixer, a ribbon 
mixer, a twin-cylinder mixer or the like. 
The following Examples and Comparative Examples further illustrate the 
present invention but should not be interpreted to limit the scope of the 
present invention.

EXAMPLES 1 to 3 AND COMATIVE EXAMPLES 1 and 2 
1.9 g (0.1 mole) of TiCl.sub.4 was reacted with 6.4 g (0.2 mole) of 
methanol. Then, 42 g of water was added thereto. The resulting solution 
was ultrasonically mixed with superfinely divided silica (mfd. by Nippon 
Aerosil Co., Ltd.) having an average particle diameter of 0.012 .mu.m in 
an amount as shown in Table 1. 
A clean slide glass was dipped into the mixture, then pulled up therefrom 
at a rate of 75 cm/min., and thereafter dried at 120.degree. C. for 30 
minutes in an air bath to obtain a lamina. 
The resulting lamina was calcined first at 300.degree. C. for 5 hours and 
subsequently at 700.degree. C. for 2 hours to obtain a lamina consisting 
of laminar titania and finely divided silica dispersed therein which 
lamina had an average size of 7 .mu.m and an average thickness of 0.8 
.mu.m. 
Then, spectral transmittance of the lamina was measured. The results are 
shown in FIG. 1. 
Also, spectral transmittance was measured on the lamina of Comparative 
Example 1 comprising laminar titania alone and the lamina of Comparative 
Example 2 comprising superfinely divided silica alone, and the results are 
also shown in FIG. 1. 
The measurement of spectral transmittance was carried out as follows: 
0.03 g of sample powder of the lamina was mixed with 0.47 g of low-density 
polyethylene powder and the resulting mixture was subjected to 
melt-kneading by means of a twin roll mill (temperature: 
100.degree.-160.degree. C.) to obtain a film having a thickness of about 
50 .mu.m. A film of low-density polyethylene free of the sample powder 
which film had a thickness of about 50 .mu.m was also prepared as control 
film in the same manner as above. Using this film as a control, spectral 
transmittance was measured on the sample film by a spectrophotometer in 
accordance with JIS K0115. 
In these Examples and Comparative Examples, the refractive indexes of the 
finely divided silica and laminar titania were 1.46 and 2.5 respectively 
and the difference therebetween was 1.04. 
COMATIVE EXAMPLES 3 to 5 
Spectral transmittance were measured on the rutile titania having an 
average particle diameter of 0.4 .mu.m (mfd. by Ishihara Sangyo Kaisha 
Ltd.), the anatase titania having an average particle diameter of 0.3 
.mu.m (mfd. by Sakai Chemical Industry Co., Ltd.) and the finely divided 
titania having an average particle diameter of 0.03 .mu.m (Nippon Aerosil 
Co., Ltd.). 
The results are shown in FIG. 2 as comparative Examples 3 to 5 
respectively. 
EXAMPLE 4 AND COMATIVE EXAMPLE 6 
To a 40% by weight ethanol solution of tetraethyl orthosilicate was added 
formic acid in an amount of two moles per mole of silicon contained in 
said solution. Then, the mixture was stirred at 70.degree. C. for 3 hours. 
Thereafter, Superfinely divided titania having an average particle 
diameter of 0.03 .mu.m (mfd. by Nippon Aerosil Co., Ltd.) was mixed 
ultrasonically therewith so that the amount of said titania was 30% by 
weight based on the weight of the silica contained in the mixture. 
Next, a clean slide glass was dipped into the mixture. Then, it was pulled 
up therefrom in a rate of 75 cm/min. This laminated slide glass was dried 
at 90.degree. C. for 30 minutes in an air bath to obtain a transparent 
surface-smooth lamina having an average size of 100 .mu.m and an average 
thickness of 1.7 .mu.m. The resulting lamina was calcined at 450.degree. 
C. for 30 minutes to obtain a lamina having an average size of 60 .mu.m 
and an average thickness of 0.9 .mu.m consisting of laminar silica and 
superfinely divided titania dispersed therein. 
Thereafter, this lamina was subjected to an ultrasonic grinding to obtain a 
lamina having an average size of 35 .mu.m and an average thickness of 0.9 
.mu.m consisting of laminar silica and superfinely divided titania 
dispersed therein. 
Spectral transmittance of the lamina was measured in the same manner as 
above. The result is shown in FIG. 3 as Example 4. 
On the other hand, spectral transmittance of the lamina having an average 
size of 35 .mu.m and an average thickness of 0.9 .mu.m consisting of 
laminar silica alone was measured in the same manner as above. The result 
is also shown in FIG. 3 as Comparative Example 6. 
In the Example, the refractive indexes of the superfinely divided titania 
and the laminar silica were 2.5 and 1.46 respectively and the difference 
therebetween was 1.04. 
EXAMPLE 5 
To 200 g of 40% by weight ethanol solution of titanium tetraethoxide were 
added 27 g of propionic acid and 1.4 g of finely divided alumina having an 
average particle diameter of 0.1 .mu.m (mfd. by Sumitomo Chemical Co., 
Ltd.) in an amount of 5% by weight based on the calculated weight of 
titania. Then, the mixture was stirred at 70.degree. C. for 3 hours. 
Thereafter, a clean slide glass was dipped into this mixture. 
This slide glass was pulled up therefrom in a rate of 50 cm/min. and 
calcinated first at 90.degree. C. for 30 minutes and subsequently at 
450.degree. C. for 30 minutes to obtain a lamina having an average size of 
20 .mu.m and an average thickness of 0.8 .mu.m consisting of laminar 
titania and finely divided alumina dispersed therein. 
Then the lamina was ground ultrasonically, and was subjected to levigation 
so that the average size becomes 10 .mu.m. 
Spectral transmittance of the resulting lamina was measured in the same 
manner as above. The result is shown in FIG. 3. 
On the other hand, spectral transmittance of a lamina consisting of the 
finely divided titania obtained in the same manner as above was measured 
in the same manner as in Comparative Example 1. 
In this Example, the refractive index of the finely divided alumina and 
laminar titania were 1.76 and 2.5 respectively and the difference 
therebetween was 0.74. 
EXAMPLE 6 AND COMATIVE EXAMPLE 7 
To a 30% by weight toluene solution of liquid epoxy resin was added finely 
divided zinc oxide having an average particle diameter of 0.05 .mu.m in an 
amount of 40% by weight based on the weight of epoxy resin and mixed 
ultrasonically. Then, a clean slide glass was dipped into the resulting 
mixture. 
The slide glass was pulled up therefrom in a rate of 50 cm/min. After 
drying at 100.degree. C. for one minute, a lamina was obtained by scraping 
the lamina layer from the slide glass by a scraper. Then, the scraped 
lamina was dried at 100.degree. C. for 10 minutes in an air bath. 
The resulting lamina consisting of laminar epoxy resin and finely divided 
zinc oxide dispersed therein had an average size of 80 .mu.m and an 
average thickness of 4 .mu.m. 
Spectral transmittance of the lamina was measured in the same manner as 
above. The result thereof is shown in FIG. 3 as Example 6. 
On the other hand, a lamina consisting of laminar epoxy resin alone was 
obtained in the same manner as above. Spectral transmittances thereof at 
300 and 500 nm are shown in Table 2 as Comparative Example 7. 
EXAMPLE 7 AND COMATIVE EXAMPLE 8 
With a 1% by weight tetrahydrofuran solution of polymethyl methacrylate was 
ultrasonically mixed finely divided zinc oxide having an average particle 
diameter of 0.05 .mu.m in an amount of 50% by weight based on the weight 
of polymethyl methacrylate. This solution was coated on a stainless roll 
having a diameter of 10 cm rotating at 3 revolutions per minute at 
60.degree. C., and scraped the lamina layer therefrom by a scraper to 
obtain a lamina. The lamina obtained had a size distribution ranging from 
20 to 200 .mu.m and a thickness distribution ranging from 2 to 5 .mu.m. 
Then, the lamina having a size ranging from 10 to 70 .mu.m was separated 
from the others by means of zigzag classificator. This separated lamina 
had a thickness distribution ranging from 2 to 4 .mu.m. 
Spectral transmittances of the lamina consisting of laminar polymethyl 
methacrylate having dispersed therein finely divided zinc oxide were 
measured at 300 and 500 nm and the results are shown in Table 2 as Example 
7. 
On the other hand, spectral transmittances of a lamina consisting of 
laminar polymethyl methacrylate alone were also measured and are shown in 
Table 2 as Comparative Example 8. 
EXAMPLE 8 AND COMATIVE EXAMPLE 9 
With an aluminum primary phosphate solution having a phosphorous content of 
7% by weight and a molar ratio of aluminum to phosphorous of 3/1 were 
ultrasonically mixed finely divided titania having an average particle 
diameter of 0.03 .mu.m in an amount of 5% by weight based on the weight of 
aluminum phosphate. 
Then, a clean slide glass was dipped into this solution. Thereafter, it was 
pulled up therefrom in a rate of 50 cm/min. and dried at 90.degree. C. for 
30 minutes in an air bath. Then, a lamina was obtained by scraping the 
lamina layer from the slide glass by a scraper. 
The lamina obtained consisting of laminar aluminum phosphate and finely 
divided titania dispersed therein had an average size of 20 .mu.m and an 
average thickness of 2 .mu.m. 
Spectral transmittances of lamina were measured at 300 and 500 nm. The 
results are shown in Table 2 as Example 8. 
On the other hand, spectral transmittances of a lamina consisting of 
laminar aluminum phosphate alone obtained in the same manner as above were 
measured at 300 and 500 nm. The results are shown in Table 2 as 
Comparative Example 10. 
EXAMPLE 9 
To 200 g of 40% by weight ethanol solution of titanium tetraethoxide were 
added 27 g of propionic acid and 2.8 g of zinc oxide having an average 
particle diameter of 0.03 .mu.m. Then, the mixture was stirred at 
70.degree. C. for 3 hours. A clean slide glass was dipped into the 
mixture. 
This slide glass was pulled up therefrom at a rate of 50 cm/min. and was 
dried at 90.degree. C. for 30 minutes and calcinated at 450.degree. C. for 
30 minutes in an air bath to obtain a lamina having an average size of 15 
.mu.m and an average thickness of 0.8 .mu.m consisting of laminar titania 
and finely divided zinc oxide dispersed therein. Then, this lamina was 
subjected to ultrasonic grinding and levigation to obtain a lamina having 
an average size of 10 .mu.m. 
Spectral transmittances of the resultig lamina were measured at 300 and 500 
nm and the results are shown in Table 2. 
EXAMPLE 10 AND COMATIVE EXAMPLES 10 and 11 
To 200 g of 40% by weight ethanol solution of titanium tetraethoxide was 
added 27 g of propionic acid. On the other hand, to 40% by weight ethanol 
solution of tetraethyl orthosilicate was added formic acid in an amount of 
two moles per mole of silicon contained in said solution. Then, both the 
solution were mixed together so that the volume ratio of TiO.sub.2 
/SiO.sub.2 was 75/25 (Example 10) or 50/50 (Comparative Examples 10 and 
11). Thereafter, the mixtures were stirred at 70.degree. C. for 3 hours 
and then ultrasonically mixed with 1.4 g of alumina having an average 
particle diameter of 0.1 .mu.m (mfd. by Sumitomo Chemical Co., Ltd.) in 
the amount shown in Table 2. 
Then, a clean slide glass was dipped into each mixture. After pulling up 
the slide glass therefrom at a rate of 75 cm/min., it was dried in an air 
bath at 90.degree. C. for 30 minutes to obtain a transparent 
surface-smooth lamina having an average size of 100 .mu.m and an average 
thickness of 1.7 .mu.m. 
Each lamina was calcined at 450.degree. C. for 30 minutes to obtain a 
lamina having an average size of 60 .mu.m and an average thickness of 0.9 
.mu.m comprising laminar titania-silica and finely divided titania 
dispersed therein. 
Then, the lamina was further subjected to ultrasonic grinding to obtain a 
lamina having an average size of 10 .mu.m and an average thickness of 0.9 
.mu.m comprising laminar titania-silica and finely divided titania 
dispersed therein. 
Spectral transmittances of these resulting laminae were measured at 300 and 
500 nm and the results thereof are shown in Table 2. 
EXAMPLE 11 AND COMATIVE EXAMPLES 12 to 14 
Using the lamina consisting laminar titania and finely divided silica 
dispersed therein prepared in Example 2, a powder foundation was prepared. 
For the comparison, powder foundation were prepared using the laminar 
titania of Comparative Example 1, commercially available powdery rutile 
titania having an average particle diameter of 0.4 .mu.m (mfd. by Ishihara 
Sangyo Kaisha Ltd.) or a commercially available finely divided titania 
having an average particle diameter of 0.03 .mu.m (Nippon Aerosil Co., 
Ltd.). 
The method for preparing the powder foundations were is follows: 
Powders such as titania, talc, sericite, yellow iron oxide, iron oxide red 
and the like were mixed together by a ribbon blender for 30 minutes. Then, 
with the resulting mixture was mixed liquid parafin, lanolin, squalane and 
the like by a Henschel mixer for 6 minutes. After perfumes were added 
thereto and mixed therewith for 2 minutes, the mixture obtained was 
subjected to screening and dieing to obtain a powder foundation. 
Stability, UV screening ability and organoleptic properties were examined 
on the powder foundations of Example 10 and Comparative Examples 12 to 14. 
The results are shown in Table 3. 
EXAMPLE 12 AND COMATIVE EXAMPLE 15 
Using the lamina of Example 2 consisting of laminar titania and finely 
divided silica dispersed therein, a pressed powder was prepared. 
On the other hand, for the comparison, a pressed powder mainly composed of 
talc was prepared. 
Method for preparing the pressed powders was as follows: 
Pigments were blended by a blender. Thereto were added the rest of the 
materials. Then, the blend was colored, sprayed with perfumes and further 
mixed together Thereafter, the resulting mixture was subjected to press 
molding to obtain a pressed powder. 
Stability, UV screening ability and organoleptic properties were examined 
on the pressed powder of Example 12 and Comparative Example 15. The 
results are shown in Table 4. 
The methods for examining the stability, UV screening ability and 
organoleptic properties were as follows: 
Stability: Changes of properties of the cosmetics were examined after one 
year-storage in a room without temperature control. 
UV screening ability (SPF value, suntan preventing factor): With 
ultraviolet rays were irradiated a skin portion with a uniform cosmetic 
coating of 2 mg/cm.sup.2 or 2 .mu.l/cm.sup.2 or a skin portion without 
cosmetic coating by a medical UV irradiator manufactured by The Toko 
Electric Corp. [M-DMR-1, illuminant: Toshiba Fluorescent Lightings: FL20S 
E-30 (.mu..sub.max : 305 nm) and FL20S BLB (.lambda..sub.max : 352 nm)]. 
Minimum energy for forming red spots were measured by an ultraviolet 
dosimeter mfd. by Tokyo Optical Co., Ltd. (UVR-305/365 D) on each case. 
The screening ability is indicated by a ratio of minimum energy for 
forming red spots on the skin portion with the cosmetic coating to minimum 
energy for forming red spots on the skin portion without cosmetic coating. 
Organoleptic properties: Cosmetics were used by 20 women for two weeks. 
Thereafter, the cosmetics were evaluated by them on every item in 5 
ratings, in which 5 indicated the best and 1 indicated the worst. The 
results shown in Tables 3 and 4 are mean values thereof. 
TABLE 1 
______________________________________ 
Amount of 
Amount of 
Laminar Finely-Divided 
Spectral 
Titania Silica Transmittance 
(parts by 
(parts by at 300 nm 
weight) weight) (%) 
______________________________________ 
Example 1 97 3 3 
Example 2 85 15 1 
Example 3 70 30 1.5 
Comparative 
100 0 12 
Example 1 
Comparative 
0 100 95 
Example 2 
______________________________________ 
TABLE 2 
__________________________________________________________________________ 
Dispersed Particle Spectral 
Matrix Amount Transmittance (%) 
Refrac- Average 
Mixed 
Refrac- 
Ultra- 
tive Size (% by 
tive 
violet 
Visible 
Substance 
Index 
Substance 
(.mu.m) 
weight) 
Index 
(300 nm) 
(500 nm) 
__________________________________________________________________________ 
Example 6 
Epoxy 1.5 ZnO 0.03 40 2.0 3 65 
Resin 
Comparative 
Epoxy 1.5 -- -- -- -- 50 70 
Example 7 
Resin 
Example 7 
PMMA 1.5 ZnS 0.05 50 2.36 
1.5 60 
Comparative 
PMMA 1.5 -- -- -- -- 95 95 
Example 8 
Example 8 
Aluminum 
1.56 
TiO.sub.2 
0.03 5 2.5 15 75 
Phosphate 
Comparative 
Aluminum 
1.56 
-- -- -- -- 60 90 
Example 9 
Phosphate 
Example 9 
TiO.sub.2 
2.5 ZnO 0.03 10 2.0 7.5 61 
Example 10 
TiO.sub.2 /SiO.sub.2 
2.0 Al.sub.2 O.sub.3 
0.1 30 1.76 
30 87 
Comparative 
TiO.sub.2 /SiO.sub.2 
1.8 Al.sub.2 O.sub.3 
0.1 30 1.76 
40 90 
Example 10 
Comparative 
TiO.sub.2 /SiO.sub.2 
1.8 -- -- -- -- 45 90 
Example 11 
__________________________________________________________________________ 
TABLE 3 
______________________________________ 
Powder Foundation 
Compar- Compar- 
Compar- 
ative ative ative 
Proportion Example Example Example 
Example 
(% by weight) 
3 10 11 12 
______________________________________ 
Laminar Titania Con- 
55 0 0 0 
taining Finely 
Divided Particle 
Laminar Titania 
0 55 0 0 
Powdery Titania 
0 0 30 0 
Finely Divided 
0 0 0 20 
Titania 
Talc 0 0 25 30 
Sericite 25 25 25 30 
Yellow Iron Oxide 
6 6 6 6 
Iron Oxide Red 
2 2 2 2 
Liquid Parafin 
2 2 2 2 
Lanoline 4 4 4 4 
Squalane 2 2 2 2 
Others 4 4 4 4 
Perfumes 0.2 0.2 0.2 0.2 
Organo- 
Spreading 4.6 4.6 1.5 2.2 
leptic Adhesive- 4.5 4.5 4.0 3.8 
Examin- 
ness 
ation Luster 4.7 4.7 2.7 3.6 
Color 4.8 4.7 2.1 4.0 
Sense 
Stability No No No Change 
Change Change Change 
SPF Value 10 5 8 10 
______________________________________ 
TABLE 4 
______________________________________ 
Pressed Powder 
Proportion Comparative 
(% by weight) Example 12 Example 15 
______________________________________ 
Iron Oxide Red 0.4 0.4 
Yellow Iron Oxide 0.2 0.2 
Black Iron Oxide 0.1 0.1 
Sericite 22.1 22.1 
Talc 30.0 70.0 
Low-Luster Laminar Titania 
40.0 0.0 
Zinc Stearate 3.0 3.0 
Squalane 2.0 2.0 
Methylphenyl polysiloxane 
2.0 2.0 
Anti-Oxidant trace trace 
Antiseptic trace trace 
Perfumes 0.2 0.2 
Organo- Spreading 4.8 4.8 
leptic Adhesiveness 5.0 3.5 
Examin- Luster 4.5 4.0 
ation Smoothness & Moist 
4.5 3.8 
Stability No Change No Change 
SPF value 8 1 
______________________________________