JPH07110961B2 - Flat gold powder for decoration - Google Patents

Description

TECHNICAL FIELD The present invention relates to gold powder used for decoration of high-grade crafts.

"Prior Art" As a gold material for decoration of this kind, gold mud produced from a peripheral portion, which is generated when a gold foil is cut into a square, that is, so-called turning waste, has been generally used.

This gold mud mixes the cutting waste with starch syrup and glue,
It is manufactured by kneading this for a long time and is used as it is by coating it on crafts.The gold particles in this gold mud are usually 0.
It is a square flat particle having an average particle size of about 1 to 30 μm.

[Problems to be Solved by the Invention] By the way, when the above-mentioned gold mud is used for decoration, there is a large variation in particle diameter in the flat direction of the gold particles, and there are the following problems.

In order to reduce the cost, it is enough to apply a large area with a small amount of gold mud, but if the variation in particle size is large, the gap between particles will be large, and the underlying color will be raised and the reflectance will decrease, so the original gold color And no gloss (3rd
(State of figure). Therefore, the coating amount must be increased,
The cost per unit coating area is high (state of FIG. 4).

When the average particle size in the flat direction becomes large, the coating film of gold mud has a glossy but surface-roughened and rough texture. Further, even if the average particle size is reduced, if the particle size variation is large, large particles partially reflect light and shine, and smooth gloss cannot be obtained. Further, since the surface of the gold particles also has irregularities, diffuse reflection due to the irregularities is promoted, and the gloss as that of gold foil cannot be obtained.

This is the case of drawing a very thin line with a fine brush for decoration.However, if the conventional gold mud is used as it is, the grain size is large and microscopic unevenness is generated at the edge of the line, resulting in an edge. In addition to being unclean, gold particles accumulate in the gaps between the brushes, tending to partially blur the lines without evenly applying the amount, making it difficult to draw clear ultrafine lines.

"Means for Solving the Problems" The present invention has been made to solve the above problems, and the configuration thereof will be specifically described below.

FIG. 1 is a plan view showing an example of a decorative flat gold powder according to the present invention. In the figure, reference numeral 1 is a gold particle, and the gold particle 1 has a substantially square shape, and the average diameter (constant direction diameter) A in the flat direction is 1 to 3 μm. The constant diameter is a value obtained by finding the maximum diameter of each particle in an arbitrary fixed direction on the basis of a micrograph or the like and averaging these.

If the value of A is less than 1 μm, the particles are too fine to be laminated horizontally on the coated surface, and the layer structure is disturbed to cause irregular reflection,
The gloss is reduced. On the other hand, when it exceeds 3 μm, the particles are too coarse and the gold particles 1 do not flow sufficiently, and gaps are generated between the particles 1 and a dense layer structure cannot be obtained.

The standard deviation σa of A is preferably 1.5 μm or less, and more preferably 1.35 μm or less. The proportion of particles having a size larger than 1.5 μm, which are too large or too small, increases, and the above-mentioned problems occur together.

On the other hand, the average diameter B of the gold particles 1 in the thickness direction (constant diameter) B is 0.
It is desirable that it is 1 to 0.3 μm. If it is less than this range, it is too thin and the fluidity is insufficient. On the contrary, if it is more than this range, the number of particles that are not aligned horizontally increases, diffuse reflection increases, and gloss decreases.

The standard deviation σ of B is preferably 0.05 μm or less. If the value is larger than this value, the number of particles that are too thin and the number of particles that are too thick increase, which causes the above-mentioned problems.

According to the ornamental flat gold powder having the above-mentioned configuration, since the individual gold particles 1 are flat, when mixed with the adhesive and applied to the article, the gold particle layer attached to the lower layer on the article surface is not covered with other gold particles. The gold particles 1 smoothly slide and spread, and the elongation is extremely good. Further, when there is a void in the lower gold particle layer, the gold particles 1 sliding and moving in the upper layer fall into the void and fill the void, so that the gold particle layer is formed thin and uniform. Therefore, a relatively small amount of gold powder can provide sufficient hiding power, a large area can be applied, and cost can be reduced.

Further, on the surface of the coating film thus formed, the flat gold particles 1 are arranged horizontally and the amount of unevenness on the surface is small, so that the light reflectance is high and the coating film has a gloss extremely similar to that of gold foil.
The quality of the article can be enhanced.

Furthermore, even when drawing fine lines with a brush, each gold particle 1
Since it is fine and has good elongation as described above, it is possible to draw a neat and clean line without causing irregularities in the contour or blurring.

Furthermore, in this example, since each particle 1 has a rectangular shape, when applied with a brush or the like, there is a high probability that the particles 1 are arranged with their sides in contact with each other, and the concealment rate can be further increased. Have.

The present invention is not limited to the rectangular particles as described above, and the same effects as those described above can be obtained with a disk shape or other irregular shape. However, in these cases, a gap is likely to be formed between the gold particles in the coated state, and the hiding rate is slightly lower than that in the case of rectangular particles.

"Examples" Next, the effects of the present invention will be demonstrated with reference to Examples.

We make various kinds of gold powder with different shapes and particle size distribution,
The above A, B, σa, σb (μm) were measured from electron micrographs, and 50% by weight of these gold powders were added to gelatin dissolved in warm water.
A gold paint was prepared by adding it at a concentration of.

Next, 0.2 g of each of these gold paints was taken and applied onto a glass plate with the same brush (made by Nekowashi Co., Ltd.), and spread to the maximum application area within the range where sufficient hiding power was obtained. After the adhesive was solidified, the coating area (cm ² ) on each glass plate was measured.

Further, the gold coating film on each glass plate was irradiated with visible light (400 to 800 nm) at an incident angle of 5 ° by using a reflectance measuring device, and the reflected light intensity was measured to obtain an average reflectance for the incident light. (%) Was measured as a gloss evaluation scale.

The results are shown in Table 1 and FIG. In Table 1, “actual” after the sample number indicates that it falls within the scope of the present invention. Further, 1 and 3 in FIG. 2 are graphs of the reflectances of the samples of Nos. 1 and 3 in Table 1.

Next, commercially available gold mud (particle size 0.1 to 30 μm, standard deviation about 2 μ
m) and the No. 1 gold paint and gold vapor deposition film,
After forming a coating film of sufficient thickness on each glass plate and solidifying, each 8 points were measured using a colorimeter (Minolta colorimeter CR-200), and the average value of each index obtained Was calculated. The results are shown below. In the Yxy color system, Y represents lightness = reflectance (%), and xy represents chromaticity (hue and saturation). In the Lab color system, L is lightness, ab
Indicates chromaticity (hue and saturation), a indicates values in the red-green direction, and b indicates values in the yellow-blue direction.

Gold mud coating film: Y = 49.39 x = 0.3907 y = 0.4143 L = 75.68 a = -0.98 b = + 38.55 L = 75.68 C = 38.56 H = 91.4 DX = 0.310 Y = 0.307 Z = 0.671 Invention (No. 1) Gold powder coating film: Y = 51.73 x = 0.3877 y = 0.4122 L = 86.52 a = -1.38 b = + 37.94 L = 86.52 C = 37.76 H = 92.0 DX = 0.291 Y = 0.286 Z = 0.638 Gold deposition film: Y = 43.59 x = 0.3980 y = 0.4094 L = 71.95 a = +2.906 b = +36.99 L = 71.95 C = 37.10 H = 85.53 DX = 0.351 Y = 0.361 Z = 0.725 As described above, the gold powder of the present invention has chromaticity. Is almost the same as the gold mud and the gold vapor-deposited film, but the brightness (Y and L) is obviously higher than the others, and the gloss is excellent.

"Effects of the Invention" As described above, according to the flat gold powder for decoration according to the present invention, since the individual gold particles are flat, when the powder is mixed with the adhesive and applied to the article, the lower layer is formed on the article surface. Other gold particles slide and spread on the gold particle layer adhered to, and the elongation is extremely good. Further, if there are voids in the lower gold particle layer, the gold particles that slide and move in the upper layer fall into the voids and fill the voids, so that the gold particle layer is formed thin and uniform.

Therefore, a relatively small amount of gold powder can provide sufficient hiding power, and a large area can be coated, so that the cost can be reduced.

Further, on the surface of the coating film thus formed, flat gold particles are arranged horizontally and there is little unevenness, so the light reflectance is high due to the flat surface of the gold particles, and the coating film has a gloss close to that of gold foil, It can enhance the sense of quality.

In addition, even when drawing a very fine line with a brush etc., the particles are fine and the elongation is good as described above, so it is possible to draw a neat and clean line without causing irregularity in the contour or blurring. You can

On the other hand, when the gold particles have a rectangular shape in a plan view, the probability that the edges of the particles contact each other when applied with a brush or the like is higher than when the gold particles have a disk shape, for example. Becomes
The thinner gold particle layer provides sufficient concealing property and further reduces the cost.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of the flat gold powder for decoration according to the present invention, and FIG. 2 is a graph comparing the reflectances of the product of the present invention and the conventional product. On the other hand, FIG. 3 and FIG. 4 are plan views showing a conventional gold mud. 1 ... gold particles

Front page continuation (72) Yuichi Kanda 128-7 Ogimachi, Aizuwakamatsu, Fukushima Prefecture Wakamatsu Works, Mitsubishi Shindoh Co., Ltd. Address Nakatsuka Co., Ltd. (56) Reference JP-A-60-204811 (JP, A)

Claims (3)

[Claims] 1. The average diameter A of the gold particles in the flat direction is 1 to 3 μm.
m, an average diameter B in the thickness direction B = 0.1 to 0.3 μm, a flat gold powder for decoration. 2. The flat gold powder for decoration according to claim 1, wherein the standard deviation σa of A is 1.5 μm or less and the standard deviation σb of B is 0.05 μm or less. 3. The flat gold powder for decoration according to claim 1 or 2, wherein the gold powder particles have a rectangular shape in plan view.