JP3044801B2 - Colored activated carbon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to activated carbon which is colored in a color other than black which activated carbon originally has. More specifically, the present invention relates to activated carbon which is colored in various vivid colors without impairing the adsorptivity. .

[0002]

2. Description of the Related Art Activated carbon is used in many applications because it has an extremely excellent adsorption property to a very large number of substances. However, its surface is black and its hands become dirty when it comes into contact with activated carbon. This is a major obstacle to use.

[0003] Therefore, it is considered that if the activated carbon can be colored vividly, its use can be greatly expanded. But,
When a colorant is directly added to the surface of activated carbon, the color is easily mixed with black on the surface to give a dull and dirty color, and the adsorbability is greatly reduced. JP-A-2-80 discloses a method of impregnating a coloring agent into a colored activated carbon so as not to impair the adsorptivity of the activated carbon.
No. 313 discloses a method in which a latex or an emulsion is attached to the surface of activated carbon, a staple fiber having a short colored fiber length is sprinkled thereon, and the staple fiber is adhered to the surface and colored.

[0004]

When coloring is performed by adding a coloring agent to activated carbon, the adsorptivity of the activated carbon is greatly reduced, and the coloring agent is mixed with the black powder on the activated carbon surface, so that it is difficult to sharply color the activated carbon. The point becomes a problem.

It is an object of the present invention to develop and provide an activated carbon having a vivid color on its surface without overcoming these two problems and hardly impairing the adsorbability of the activated carbon.

[0006]

The present inventors have noticed that titanium dioxide used as a white pigment has an extremely high hiding power, and the ability of activated carbon to hide black is also very strong. High freshness of color on activated carbon surface
As a result of studying a method of causing the same , the present invention has been reached.

That is, after an emulsion containing titanium dioxide is impregnated on activated carbon, a colorant is further added on the impregnated layer.
Is a colored activated carbon formed by forming an attachment layer of an emulsion containing

Here, an emulsion refers to a state in which liquid phase particles of a polymer substance are stably dispersed in an aqueous phase, and the polymer substance includes a rubber-based latex. Less than,
The present invention will be described in detail.

The activated carbon used in the present invention is a carbon material having a pore structure. It usually has a large surface area of several hundred m ² or more per gram and has a unique property of exhibiting high adsorptivity.

[0010] The raw material of activated carbon is usually a charcoal such as coconut shell or wood or coal, and is produced by activating these raw materials at high temperature with steam or carbon dioxide gas. Alternatively, it may be made by treating with zinc chloride, phosphoric acid, concentrated sulfuric acid or the like. Although the properties of the activated carbon obtained by the raw materials or production methods are somewhat different, activated carbons produced by any raw materials and methods can be used in the present invention. Activated carbon has many shapes such as crushed carbon, granulated carbon, granular carbon or activated carbon fiber, activated carbon felt, activated carbon fabric, activated carbon sheet, etc., depending on the purpose of use, and any form of activated carbon can be used in the present invention. .

The titanium dioxide used in the present invention can be used as long as it is a white powder, and any of rutile type and anatase type can be used.

[0012] Titanium oxide is produced by a sulfuric acid method, a chlorine method or the like, but may be produced by any method. Depending on the purpose, those which have been surface-treated with a soluble salt such as aluminum, zinc or silica in order to enhance the suitability of the pigment may be used, but titanium oxides thereof may also be used.

In the present invention, an emulsion refers to a liquid in which a liquid phase component is stably dispersed in an aqueous phase. The liquid phase component of the dispersed phase is usually a polymer substance, and exhibits high adhesiveness when the water of the dispersion medium evaporates. Emulsions having such properties are suitable for the present invention.

Examples of the polymer substance include vinyl acetate, acrylic, synthetic rubber, vinylidene chloride, vinyl chloride compounds and copolymers thereof.

When the dispersoid is a synthetic rubber-based polymer compound, it is usually called a latex. Latex is suitable for the present invention because the latex has high adhesiveness, the dispersion is stable even if the average particle size of the dispersoid is large, and the degree of decrease in the amount of adsorption is small when applied to the surface of activated carbon.

The colorant used in the present invention is not particularly limited, but organic or inorganic pigments and dyes can be widely used.
In addition, compounds which have a color, but which are rarely used as a coloring agent, can be used as long as they can be stably attached to the activated carbon surface. For example, cuprous iodide, cupric phosphate, copper sulfide and the like are used.

In order to make the surface of activated carbon white in the present invention, it is necessary to impregnate an emulsion containing titanium dioxide. The emulsion may contain titanium dioxide, aluminum, zinc, silica or other additives. The composition of the colorant is not particularly limited. For example, 1 to 100 parts of an emulsion (solid content), 0 to 200 parts of water, 0 to 20 parts of a thickener and the like are added, and the mixture is sufficiently stirred. And uniformly dispersed.

The method of firmly adhering to the activated carbon surface is, for example, to uniformly sprinkle the white composition on the activated carbon particles,
The particles are mixed well and adhered uniformly to the surface. At this time, if the added amount of the composition is appropriate, moisture is easily absorbed into the inside of the activated carbon particles, so that the surface is exposed while mixing the particles, and the particles adhere to each other. Not to be. By drying this, white activated carbon is obtained.

The decrease in the amount of activated carbon adsorbed due to the addition of the coloring agent is very small or hardly observed as will be shown in the examples below. In the case of molding activated carbon particles, latex is sometimes used as a binder, in which case the amount of adsorption is considerably reduced, but it is noted that the colored activated carbon of the present invention hardly reduces the amount of adsorption. This is considered to be due to a synergistic effect due to the inclusion of the synthetic rubber-based polymer compound, titanium dioxide and other coloring agents when the particles dispersed in the latex partially adhere to the activated carbon surface.

The amount of the colorant to be added is preferably 5 to 30%, and generally about 20% in terms of solid content after drying.

Impregnation of the thus obtained white activated carbon
An additional layer of an emulsion containing a colorant such as an organic or inorganic pigment or dye is further formed on the layer, so that the layer is colored in various clear colors other than white. At this time, the colorant is preferably 0.01 to 10% in terms of solid content, and can be appropriately selected in consideration of the application, the coloring concentration, and the like.

[0022]

[0023]

[0024]

By simultaneously adding a colorant of a color other than white to the emulsion together with titanium dioxide, the emulsion can be colored to a color other than white by a single operation. However, after coloring in advance with a dispersion containing titanium dioxide and then coloring with a dispersion containing a colorant of a color other than white, coloring can be performed much more clearly.

[0026]

[Action] When various coloring agents are directly attached to activated carbon, the color of the coloring agent and the black color of the activated carbon are mixed to give a black tint, resulting in a dull color, that is, a color with low brightness and low saturation.
It is difficult to obtain vividly colored charcoal. Therefore,
There are almost no applications that can be used as is.

Titanium oxide has the highest refractive index among the white pigments, so that a pigment having high coloring power and hiding power can be produced. Further, since the specific gravity is small, a stable composition can be easily obtained.

Therefore, first, titanium oxide is uniformly applied to the surface of the activated carbon to conceal the black color, and thereafter, an air containing other colorant is used.
By impregnating the marjon on it, it is possible to obtain a colored charcoal of vivid color.

In the case that requires colored activated carbon lightness and saturation is high, especially is once made white carbon, it is necessary to impregnated the emulsion further comprises a colorant. A mixture of titanium dioxide and white colors other than the colorant, when colored with a liquid dispersed in the emulsion can be quite saturation decreases avoided
It's hard .

Further, since the surface of the activated carbon is covered with the coloring agent, the hands are not blackened even when touched by hand.

[0031]

The present invention will be described more specifically with reference to the following examples.

Example 1 15 parts of titanium oxide and 10 parts of an acrylic emulsion solid (50%) per 100 parts of activated carbon (activated carbon manufactured by Kuraray Chemical Co., Ltd., Kuraray Coal 2GG)
Parts, 2% 3% CMC (Carboxymethyl Cellulose),
A white composition was prepared by uniformly dispersing 25 parts of water, and the activated carbon was sprinkled little by little so as to be uniform while being stirred well.

[0033] After the moisture is mixed well until it is absorbed by the activated carbon, colored after becoming smooth state surface, it is taken out and dried for 3 hours with activated carbon impregnated in a dry temperature 120 ° C., activated carbon white An intermediate was obtained. It was vivid white, had no discoloration when touched by hand, and had no sticking of the fingertips at all, and was firmly attached.

In addition, the activated carbon before coloring and the intermediate after coloring
Table 1 shows the results of measuring the amount of benzene adsorbed on a certain activated carbon by JIS (K1474). Almost no decrease in the amount of adsorption is observed.

[Table 1]

The activity of the white colored intermediate obtained above
100 parts of charcoal , red organic pigment, Sumitone
Carmine B (CIP, manufactured by Sumitomo Chemical Co., Ltd.)
4 parts of an acrylic red (solid content 50%) is uniformly dispersed in 4 parts of an acrylic emulsion (solid content: 50%) .
Chakusuru so in sprinkled little by little.

After mixing well until the water is absorbed by the activated carbon, after the surface becomes smooth, 12
After drying at 0 ° C. for 2 hours and taking out, activated carbon colored vivid red was obtained.

The black color of the activated carbon was almost hidden.
There was no discoloration even when touched by hand, and it was firmly attached.

A white intermediate before coloring and a red intermediate after coloring
Table 1 shows the results of measuring the benzene adsorption amount of the color activated carbon according to JIS (K1474). Benzene adsorption before coloring
There is hardly any decrease compared to the intermediate .

Comparative Example 1 100 parts of activated carbon (Kuraray Chemical Co., Ltd., activated carbon, Kuraray Coal 2GG) was added to red organic pigment, Sumitone Carmine B (Sumitomo Chemical Co., Ltd.)
C. I. Pigment Red 5 grade pigment) 15 parts, acrylic emulsion (solid content 50%) 10 parts, 3% CMC (carboxymethylcellulose) 2 parts, 25 parts of water to make a red composition uniformly dispersed, stir activated carbon well Sprinkled little by little to make it even.

After the water was thoroughly mixed until it was absorbed by the activated carbon, the surface became smooth and the activated carbon impregnated with the activated carbon was dried in a dryer at a temperature of 120 ° C. for 3 hours. A blackish-red activated carbon mixed with the colorant red was obtained. There was no discoloration even when touched by hand, and it was firmly attached.

Table 1 shows the benzene adsorption amounts of activated carbon before and after coloring measured by JIS (K1474).

( Comparative Example 2 ) 12 parts of titanium oxide and acrylic emulsion (solid content: 50%) per 100 parts of activated carbon (Kuraray Coal 2GG)
12 parts, 2 parts of 3% CMC, red organic pigment, Sumito
ne Carmine B (Sumitomo Chemical Co., Ltd., C.I.
I. Pigment Red 5th grade pigment) 4 parts, water 25
A red composition in which parts were uniformly dispersed was prepared, and the activated carbon was sprinkled little by little so as to be uniform while being stirred well.

After the water is thoroughly mixed until it is absorbed by the activated carbon, the surface becomes smooth, and then the activated carbon impregnated is dried for 3 hours in a dryer at a temperature of 120 ° C. to obtain red activated carbon. Was. Saturation was obtained in Example 2.
It was considerably lower than the red color of activated carbon.

The black color of the activated carbon was almost hidden.
There was no discoloration even when touched by hand, and it was firmly attached.

Table 1 shows the results of JIS (K 1474) measurement of the amount of benzene adsorbed on the activated carbon before and after coloring.
Shown in Reduction of the amount of adsorption is not a recognized almost.

[0046]

According to the present invention, when various coloring agents are directly attached to activated carbon, the color of the coloring agent and the black color of the activated carbon are mixed with each other to give a black tint and a dull color. Therefore, there is almost no use that can be used as it is.

The colored activated carbon of the present invention is based on a base material whose surface is coated with titanium dioxide which is a white pigment having extremely high hiding power, so that white and various sharp colored carbons can be obtained. It can be used in many areas where activated carbon was not used because it was black.

Further, it is noted that the most important property of activated carbon, adsorbability, is hardly reduced, and the surface of the activated carbon is firmly covered with a coloring agent, so that the hands become black even when touched by hand. Another major feature is that it does not get dirty.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B01J 20/20

Claims (1)

(57) [Claims] 1. A colored activated carbon obtained by attaching an emulsion containing titanium dioxide to activated carbon and then further attaching an emulsion containing a coloring agent. "