JPH08259219A - Synthetic mica suppressing yellowing - Google Patents

Abstract

PURPOSE: To effectively suppress the yellowing of synthetic mica over a long period of time by incorporating one or more among Co, Ce and Nd into the mica. CONSTITUTION: Oxide of at least one kind of metal selected from among Co, Ce and Nd is added to a mixture of potassium silicofluoride with potassium carbide, magnesium oxide and silicon dioxide and they are melted, cooled and pulverized to obtain the objective synthetic mica contg. 0.1-15wt.% at least one kind of metal selected from among Co, Ce and Nd and having 0.1-100μm average particle diameter measured by a sedimentation method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention effectively masks the yellowness caused by changes over time in coating films, resins, fibers, papers, etc., and also improves the yellowness of the skin when used in cosmetics. The present invention relates to synthetic mica having a property of effectively hiding.

[0002]

2. Description of the Related Art Synthetic mica powder is a coating material for the purpose of improving heat resistance, mechanical strength and sliding property.
It is used as a plastic additive and an extender pigment for cosmetics. However, coating films, resins, fibers, decorative papers, and the like have a problem that they change with time due to light rays and yellowing occurs. The occurrence of yellowing is a problem mainly when the coating film or the like is colorless or white or a pale color close to these. It is considered that the cause of these yellowing is mainly due to deterioration of the resin.

With respect to the problem of yellowing of a coating film or the like, conventionally, an ultraviolet absorber, an ultraviolet scatterer or the like is added to prevent the problem. However, when an ultraviolet absorber or the like is added, there is a certain effect for a certain period of about 6 months, but there is a problem that the effect almost disappears after one year or more. In the case of cosmetics, there has been a demand for covering the yellowness of the skin, but a method for naturally covering the yellowness of the skin has never been known.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and conceals the occurrence of yellowing with the passage of time, and, when applied to cosmetics, the skin. It is an object of the present invention to provide a synthetic mica that effectively covers the yellowness of

[0005]

Means for Solving the Problems As a result of intensive research to solve the above problems, the present inventors have found that Co, Ce or Nd
It was found that the synthetic mica containing contains, while effectively masking the yellowness caused by light rays in the coating film, plastic, etc., and effectively covers the yellowness of the skin,
The present invention has been reached. That is, the present invention is a synthetic mica containing C
It is characterized by containing at least one of o, Ce or Nd, and having the property of masking the yellowish color in addition to the property as an additive.

The synthetic mica used in the present invention is C
There is no particular limitation as long as it contains at least one of o, Ce and Nd. The content of one or more of Co, Ce or Nd in the synthetic mica of the present invention is preferably 0.1 to 15%. Below this, yellowing is not effectively prevented, and above this, synthetic mica is not formed. The particle size of the synthetic mica of the present invention is 0.
It is preferably 1 to 100 μm. Outside this range,
Since it is not uniformly dispersed in the paint or synthetic resin, a uniform coating film cannot be formed.

The synthetic mica production method itself may be any of melt synthesis, hydrothermal synthesis, solid-state reaction, etc., but the melt synthesis method is particularly preferable because of its good crystallinity. The synthetic mica of the present invention is used as a coating composition by mixing it with various paints, kneading into various plastics as an additive for plastics, or as an additive for cosmetics in the same manner as conventional synthetic mica. You can use it.

[0008]

The function of the synthetic mica of the present invention is as follows.
When blended in cosmetics and the like, it is almost colorless, but has a very slight bluish tint, so that it is possible to effectively mask the occurrence of yellowing and the yellowing of the skin due to changes over time.

[0009]

EXAMPLES Next, the present invention will be further described with reference to examples, but the present invention is not limited to these examples. Example 1 18.2% by weight of potassium silicofluoride, potassium carbonate 4.
To 100 parts by weight of a formulation consisting of 7% by weight, magnesium oxide 28.2% by weight, aluminum oxide 11.9% by weight and silicon dioxide 37.0% by weight, 10 parts by weight of cobalt oxide were added and mixed well. This mixture was put in an alumina crucible, melted in an electric furnace at 1450 ° C., and then cooled in the furnace to obtain purple synthetic mica crystals containing 7.2% of Co. Next, it was ground with a ball mill for 24 hours to obtain a synthetic mica powder of the present invention having a sedimentation method average particle diameter of 23 μm.

Example 2 The same procedure as in Example 1 except that cerium oxide was used in place of cobalt oxide, and the precipitation blue light blue synthesis of the present invention containing cerium in an amount of 7.4% and having an average particle size of 23 μm was performed. A mica powder was obtained. Example 3 Except that Nd oxide is used instead of cobalt oxide,
In the same manner as in Example 1, a pale purple synthetic mica powder of the present invention containing 7.8% of Nd and having a mean particle size by precipitation method of 23 μm was obtained.

Example 4 10% by weight of the synthetic mica of the present invention obtained in Example 1 was mixed with a thermosetting acrylic melamine resin, which was sprayed on a steel plate and baked at 140 ° C. for 20 minutes. The coating film thus obtained was a highly transparent and smooth coating film which was almost colorless and had a very slight bluish tint. When this coating film was subjected to an outdoor exposure test for one year, it remained as a clear and almost colorless yellowish film. For comparison, the coating film obtained by blending the conventional synthetic mica with the ultraviolet absorber changed to a yellowish coating film. Examples 5 to 6 Using the powders obtained in Examples 2 and 3, an exposure test for one year was conducted in the same manner as in Example 4 above. As a result, in all cases, a clear coating film having a yellowish and less noticeable appearance was obtained.

Example 7: Cosmetic (foundation) Pigment obtained in Example 1 20 parts Liquid paraffin 25 parts Vaseline 5 parts Isopropyl myristate 5 parts Stearic acid 2 parts POE (25) monostearate 5 parts Yellow iron oxide 2 parts Bengal 1 part talc 5 parts Propylene glycol 5 parts Glycerin 5 parts Perfume 0.5 parts Purified water 22.5 parts

The above components are mixed in the above proportions to give 75 to 8
After heating to 0 ° C to uniformly dissolve and mix, the mixture was cooled to 30 ° C to obtain a foundation cream. When this foundation cream was applied to the skin, a concealing effect that the yellowness of the skin was not naturally noticeable was clearly recognized. Examples 8 to 9 The powders obtained in Examples 2 and 3 were tested in the same manner as in Example 7 and applied to the skin in the same manner. Similarly, the concealing effect that the yellowness of the skin became inconspicuous. Was clearly recognized.

[0014]

[Effect] As described above, according to the present invention, a special synthetic mica which is completely different from the conventional method of using an ultraviolet absorber is used for the problem that the coating film, plastic, etc., turn yellow due to aging. It was solved by using
Compared with the conventional method, it has a great effect of effectively masking yellowing for a very long time. Further, since a method of hiding the skin color naturally when a cosmetic is applied to the skin has not been known at all, the present invention has an unprecedented epoch-making effect.

Claims (5)

[Claims] 1. A synthetic mica containing 1 of Co, Ce or Nd.
It contains more than one seed, and in addition to its properties as an additive,
A synthetic mica having a property of masking a yellowish color. 2. The synthetic mica according to claim 1, wherein the content of at least one of Co, Ce or Nd is 0.1 to 15%. 3. The average particle size of the synthetic mica by the sedimentation method is:
The synthetic mica according to claim 1, which has a thickness of 0.1 to 100 μm. 4. A base material containing the synthetic mica is a paint,
The synthetic mica according to claim 1, wherein the synthetic mica is a resin, a fiber, or a paper, and the hiding yellowness is caused by a change with time. 5. The synthetic mica according to claim 1, wherein the base material to which the synthetic mica is mixed is a cosmetic material, and the hiding yellowness is the yellowness of the skin.