JPH08225348A - Colored artificial aggregate for road/building material and its production - Google Patents

Abstract

PURPOSE: To obtain a colored artificial aggregate having clear hue and excellent wear resistance, durability, mechanical strength and dislocation resistance, etc., by specifying an aggregate composition in the aggregate derived from burning a mixture of porcelain body with a prescribed pigment. CONSTITUTION: The objective aggregate is made to have a dense structure by including <=0.15 wt.%, preferably <=0.1wt.% titanium dioxide content and <=2.0%, preferably <=1.5% water absorption. This aggregate is obtained by preparing a porcelain body with mixing a raw material (e.g., plastic component of SiO2 -source raw material, Al2 O3 -source raw material and clay, etc.) so as to contain <=0.15-wt.% titanium dioxide in a burned material, adding a prescribed pigment (e.g., iron oxide) into the porcelain body, crushed and blended so as an average granule diameter to be <=300μm, molding to a molded material having a prescribed size and burning the resultant molded material to have <=2.0% water absorption.

Description

Detailed Description of the Invention 【Technical field】

[0001] The present invention relates to an artificially colored aggregate for roads and building materials, and a method for producing the same.
The present invention relates to an artificially colored aggregate for roads and building materials having mechanical strength, abrasion resistance, shear resistance and the like, and an advantageous production method thereof.

[Background Art]

[0002] Conventionally, natural crushed stone has been generally used as aggregate for roads or building materials.
Along with the widespread use of color pavements as display pavements for bus lanes and landscape pavements for vehicles and sidewalks, such color pavements, with the exception of some natural stone pavements,
Artificial colored aggregates are beginning to be used.

In particular, in recent years, the construction of color pavements on roads has been increasing, and the purposes thereof have been wide-ranging, such as improving recognition of bus lanes, alerting drivers, and improving road scenery. In the case of such a color pavement for a roadway, high-performance color aggregates and binders are naturally required. In other words, it is excellent in durability, excellent in abrasion resistance, excellent in flow resistance, has aging resistance, fading resistance, excellent in running property, good in flatness, and smooth It must have many characteristics such as being able to run and not change over time, being excellent in safety, having sufficient sliding friction resistance, and having sufficient sliding resistance even in rainy weather. -ing

[0004] In addition, the color pavement of such a roadway includes:
At the same time, it is of course required that the pavement be adapted to the user and the roadside environment. That is, it is also required that they have excellent water permeability, noise prevention performance, and landscape performance, and also have excellent visibility in rainy weather and at night.

[0005] These performances are, of course, determined by the performance of binders such as road aggregates, asphalt, resin, cement and the like and the proper design of the compound by their blending. At that time, it is natural that the aggregate also requires high performance.

By the way, in the case of the conventional artificial colored aggregate, a predetermined pigment is added to the porcelain clay or the clay for tiles, and the mixture is subjected to a molding / drying step, followed by firing. It is manufactured by crushing and sizing the fired product
Usually, at this time, as the firing temperature becomes higher, the sintering proceeds, and the mechanical and chemical performances are improved.

However, the pigment in this case is a base colorant, and the pigment and the base are mixed and fired. Therefore, the pigment must be stable to the firing temperature of the substrate, that is, the clay. In the case of the above-mentioned porcelain or tile base material, in order to obtain sufficient performance, it depends on the nature of the base material, but it is 1180 to 1230 ° C.
However, at such a high temperature, discoloration occurs due to the synergistic effect of the pigment, the clay, and the pigment clay, and also depending on the firing atmosphere.

[0008] Therefore, it is difficult for the sintered aggregate to have sufficient performance and to obtain a clear color. In particular, it becomes difficult to obtain a clear color at a high temperature in red coloring by iron oxide and green coloring mainly by chromium oxide. That is, in order to obtain a vivid color, the firing temperature must be lowered, and in such a case, the performance of the aggregate is reduced, which is a trade-off. As a result, conventional aggregates were produced with compromises in both sharpness and function.

[0009]

Here, the present invention has been made in view of such circumstances, and according to the intended use by mixing with asphalt, cement, or resin, which is not present in conventional artificial aggregates. It is an object of the present invention to provide a colored artificial aggregate for roads and building materials which has sufficient performance that can be suitably used, has extremely high sharpness, and does not have pigment spots.

[0010]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, as a raw material, a raw material having a low content of titanium oxide, that is, as a raw material of SiO ₂ , silica (including silica sand), kaolin, , Clay, feldspar, etc.,
If necessary, feldspar, pottery stone, etc. are used as alkali source materials such as K ₂ O and N ₂ O, and further, kaolin, alumina and sand shale are used as Al ₂ O ₃ source materials. As the plastic component, a component having a high cation exchange amount such as clay, bentonite, montmorillonite, and sericite having a low titanium oxide content is used, and the total TiO ₂ content of these components is 0.15% by weight or less based on the fired product. After mixing and pulverizing the porcelain clay kneaded as described above, it is molded, and thereafter, the fired product has a dense structure, and based on the water absorption rate.
It was found that a colored artificial aggregate for road / construction material having a vivid color and a sufficient function can be obtained by firing at an appropriate temperature so as to be 0% or less, and the present invention is completed. Was reached.

[0011] Accordingly, the gist of the present invention is an aggregate obtained by firing a mixture obtained by mixing a predetermined pigment into a porcelain clay, and the titanium oxide content in the aggregate composition after firing. Is not more than 0.15% by weight, and has a dense structure having a water absorption of not more than 2.0%.

The colored artificial aggregate according to the present invention is prepared by blending a raw material having a low titanium oxide content so that the titanium oxide content in the fired product is 0.15% by weight or less. While preparing the soil, a predetermined pigment is mixed with the porcelain clay, and the average particle diameter is 300 μm.
After pulverized and mixed as described below, molded into a molded product of a predetermined size, and then, the molded product is fired to form a fired product having a dense structure having a water absorption of 2.0% or less. It is advantageously produced according to the method for producing a colored artificial aggregate for roads and building materials characterized by the following.

In the method for producing a colored artificial aggregate, the porcelain clay is (a) a SiO ₂ source selected from the group consisting of silica, kaolin, clay, feldspar, porcelain stone, and limestone. A raw material, (b) an Al ₂ O ₃ source material selected from the group consisting of alumina, kaolin, and clay shale; and (c) a plastic component selected from the group consisting of clay, bentonite, montmorillonite, and sericite. , Mainly.

Of course, according to the above-mentioned present invention, the titanium oxide content in the aggregate composition after firing is 0.15% by weight or less, preferably 0.1% by weight.
In addition, the aggregate is densely sintered at a high temperature so that the water absorption of the aggregate is 2.0% or less, preferably 1.5% or less.

In the present invention, various raw materials may be used as raw materials, and in the manufacturing method,
In addition to wet pulverization, dry pulverization, various granulation methods to obtain aggregates of a desired particle size, and sintering may also employ various methods using a tunnel kiln, a rotary kiln, or the like. It should be understood that these are not particularly limited. However, in any manufacturing method, after mixing the pigment in the porcelain clay,
It is necessary to carry out the pulverization and mixing operation so that the average particle diameter is not more than 300 μm, whereby the characteristics of the artificially colored aggregate obtained can be advantageously improved.

[0016]

As mentioned above, the artificial colored aggregate for road and building materials according to the present invention is obtained by adding a predetermined pigment to a finely pulverized ceramic material to be a porcelain clay. The molded product obtained by molding into a shape is calcined, and the calcined product is obtained, or is obtained by pulverizing the calcined product. As a raw material for providing such an artificially colored aggregate, as described above, silica sand ( An SiO ₂ ) component, an alumina (Al ₂ O ₃ ) component, an alkali component, and a plastic component are appropriately combined and used, and various raw materials are selected and used. In particular, relatively high purity,
Kaolin, clay, and feldspar are mainly used as raw materials having a low content of titanium oxide, and clay is added as a plastic component. The clay component has low purity and may include titanium oxide and other components that cause changes. Therefore, it is preferable to suppress the compounding amount as low as possible, and to replace it, increase the plasticity by adding a small amount of highly pure components such as bentonite, montmorillonite, and sericite, which have a high cation exchange amount.

Generally, it is well known that when a porcelain or tile base material is fired at a high temperature, the fired product is darkened. This is an effect of titanium oxide and manganese oxide, and particularly iron oxide and titanium oxide. The study of coloring by
K. KUMANIN "Trans. State Ceram. Res. Inst.
USSR Leningrad "vol.6, 36, 101-102 (192
8), where the titanium oxide content is 0.
It is stated that as it increases from 85% to 1.85% and even to 7.85%, it changes from light gray to deep gray on the surface and from light gray to blue on the cross section. It is considered that when the amount of iron oxide is large, redness is added to the above, and the color changes from light brown to dark brown.

[0018] Conventional base materials used for ceramics, tiles and the like usually contain titanium oxide in a proportion exceeding 0.5% by weight. This is due to the inclusion of 40%.

The present inventors have studied the darkening of the green body at the time of high-temperature sintering. At present, at a suitable price range that is industrially available at present, a high-purity raw material mixture, that is, high-purity kaolin and clay are used. , Feldspar and clay were mixed to obtain a titanium oxide content of 0.20% by weight. With this formulation,
Although darkening during high-temperature firing was reduced to a great extent, it was not yet sufficient.As a result of further investigation, kaolin, feldspar and quartz sands were obtained in relatively high purity, but high purity was obtained in highly plastic clay. Things turned out to be difficult to obtain. Therefore, by converting all or a part of the clay to a component having a high cation exchange amount such as bentonite, montmorillonite, and sericite, the titanium oxide content is reduced to 0.02 to 0.15.
It succeeded in reducing the weight to%.

As a result, as the titanium oxide content,
When the content is less than 0.15% by weight, the darkening of the color is sharply reduced. When the content is less than 0.10% by weight, the color change and the high-temperature firing can improve the aggregate performance. The ratio can be reduced to 2.0%, preferably 1.5% or less.

In addition, in the case of a composition having a deep darkening, the problematic color unevenness, that is, the color unevenness between the aggregates or between the surface layer and the inside of the aggregate can be solved at the same time. .

In the above description, part or all of the clay is converted to bentonite, montmorillonite or sericite. Of course, clay having high purity and low titanium oxide content can be obtained. Then, even if it is used, the above-mentioned effects can be sufficiently exerted.

[0023]

EXAMPLES Hereinafter, representative examples of the present invention will be shown to clarify the present invention in more detail. However, the present invention is not limited by the description of such examples. Needless to say, it is not something to receive. Further, in addition to the following specific examples, in addition to the following embodiments, the present invention may be modified in various ways based on the knowledge of those skilled in the art without departing from the spirit of the present invention.
It should be understood that modifications, improvements, etc. may be made.

First, alumina having a low iron and titanium content, kaolin and silica sand as raw materials of silica sand are prepared as artificial colored aggregate raw materials for road and building materials, feldspar as alkali raw materials, clay and bentonite as plastic components, and Iron oxide (pigtail) as a pigment was prepared.

Next, these raw materials were blended, and 5.0 wt% of Benji was added as a pigment externally to the mixture.
Example 1 (content of titanium oxide: 0.05% by weight) was used.
Further, clay and titanium oxide were further added to and mixed with this mixture to prepare Example 2 (titanium oxide content: 0.15% by weight).
And the composition of the comparative example (titanium oxide content: 0.50 weight%) was obtained. Table 1 below shows the chemical analysis values (% by weight) of these obtained compound base materials and the base materials for porcelain tiles generally used as reference examples after firing. In addition, this chemical composition was measured by X-ray fluorescence analysis and obtained.

[0026]

[Table 1]

Referring to the chemical composition of the raw material mixture in Table 1, in Example 1, since a high-purity raw material was used, a raw material having a titanium oxide content of 0.05% by weight was obtained. Was done. According to the study of the present inventors, the titanium oxide content is 0.0
It has been confirmed that up to 2% by weight can be obtained.

Example 2 (titanium oxide content: 0.1
5% by weight) and the comparative example (titanium oxide content: 0.56% by weight) are clay and titanium oxide added artificially, and they are used to see the effect of changing the titanium oxide content. , Are compounded.

Further, comparing these compounds with the generally used base material for porcelain tiles, in addition to the small amount of titanium oxide, the amount of alumina was 18 to 19% by weight.
The amount of calcium is about twice as much as 0.6% by weight, and the amount of magnesium is also large. It is considered that these components, other than titanium oxide, are effective in preventing color change and darkening of the pigment.

Then, using each of these compound bases, after coarsely crushing, they are put into a ball mill, water is further added, and wet crushing is carried out until the average particle diameter becomes 300 μm or less. Got the corresponding slurry. Next, the obtained slurry was dehydrated with a filter press, and then formed into a predetermined shape using an auger machine.

Thereafter, each molded product thus obtained was dried and then fired using a rotary kiln having a diameter of 1.8 m and a length of 60 m. The residence time is 4 hours, and the temperature is gradually increased from 1170 ° C to 1240 ° C.
At each stage, the sample was taken out, the color tone change and the physical properties of the fired aggregate were measured, and the obtained results are shown in Tables 2 to 5 and 6 below.

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

[Table 6]

As for the change in the color tone of the aggregate depending on the firing temperature in the rotary kiln shown in Tables 2 to 5, the color tone was measured using a Minolta colorimeter CR-31.
0 (Minolta Co., Ltd.) and the direct reading method for stimulation using the Hunter Lab color system.

As is clear from the above results, in the substrate of Example 1 having a titanium oxide content of 0.05% by weight, even if the firing temperature is increased, the lightness L, the red stimulus a, and the yellow stimulus b In both cases, it is recognized that there is little decrease, high-temperature baking is possible, and the occurrence of color spots is small.

The titanium oxide content is 0.15% by weight.
In Example 2, both the brightness and the stimulus values a and b gradually decrease as the firing temperature rises. However, when the firing temperature exceeds 1200 ° C., the brightness and the stimulus values a and b start to drop sharply. Although some color spots occur, it can be used sufficiently up to 1200 ° C.

On the other hand, when the titanium oxide content is 0.5
In the comparative examples of 6 and 0.60% by weight and the reference example of general porcelain material, when the firing temperature exceeds 1180 ° C., L,
It is recognized that both a and b start to decrease, especially the yellow stimulus value b is drastically decreased, and the overall color tone changes from red to dark brown. In addition, the color spots between the aggregates and the color spots in the inner and outer layers of the aggregates also increased rapidly, and from the viewpoint of color, 1170 to 11
It is found that practical application is difficult unless the firing temperature is lower than 75 ° C.

Table 6 showing the physical properties of the aggregate depending on the firing temperature.
As is clear, in Examples 1, 2 and Comparative Examples using ceramic base materials having substantially the same composition except for the content of titanium oxide, a change in physical properties due to the firing temperature was observed, but the difference between the materials was small. The average value is shown in Table 6 because of the variation range. Looking at this change in the physical properties of the aggregate due to the sintering temperature, when sintering at 1180 ° C. or less, the water absorption of the aggregate becomes 2.0% or more, and the loss and loss of the aggregate and the crushing value of the aggregate deteriorate in Los Angeles. ° C
The above firing is desirable. In addition, when the firing temperature is increased, sintering proceeds, the apparent specific gravity increases, the water absorption decreases, the structure becomes dense, and the loss and weight loss of Los Angeles and the aggregate crushing value decrease, and the physical properties improve. . However, if the temperature exceeds 1240 ° C., since the molten foam is fired, the apparent specific gravity decreases, and other physical properties also decrease. Therefore, from the viewpoint of physical properties, a temperature higher than 1180 ° C. and lower than 1240 ° C. is desirable. Among them, the higher is better, but the lower is better in terms of color.

Looking at the change in color tone and the change in physical properties as described above, the content of titanium oxide is high,
When the amount reaches 0.6% by weight, the color tone changes drastically.
If the temperature is not higher than 0 ° C, sufficient color tone cannot be obtained, but 117
At a sintering temperature of 0 ° C. or less, baking is not enough, and the physical properties such as moisture content, apparent specific gravity, abrasion loss, aggregate crushing value, etc. decrease, making it difficult to use as aggregate for roads and building materials. 0.15% by weight is a limit value. In this case, a firing temperature of 1190 to 1180 ° C. or less is desirable from the viewpoint of color tone. In this case, the water absorption rate is 2.0%, which is a limit value of physical properties. If the titanium oxide content is 0.10% by weight or less, a firing temperature of 1200 to 1220 ° C. can be sufficiently obtained from the viewpoint of the color tone, so that the physical properties can provide sufficient performance as an aggregate.

That is, the content of titanium oxide in the aggregate composition after firing is 0.15% by weight or less, preferably 0.1% by weight.
An artificially colored aggregate for roads and building materials characterized by having a dense structure such that the water content is 10% by weight or less and the water absorption is 2.0% or less, preferably 1.5% or less. It has been found that they have sufficiently vivid coloration and physical properties for use as building materials and building materials.

[0044]

As is clear from the above description, the colored artificial aggregate for roads and building materials according to the present invention is used as a general landscape material, as well as for improving the recognition of the bus lane and for the driver's attention. As a colored aggregate for building and as a colored artificial aggregate for building materials and construction, it has a sufficiently clear hue and also has mechanical and chemical functions such as abrasion resistance, durability, aging resistance and fading resistance. , Can be widely used for each application and can be advantageously improved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inoue Muneo 4 At 11 Shiogusa-cho, Seto City, Aichi Prefecture Uchiga Sera Mix Co., Ltd. (72) Inventor Toyohiko Tsukada 4 At 11 Shiogusa-cho, Seto City Aichi Prefecture Uchiga Sera Mix Within the corporation

Claims (3)

[Claims] 1. An aggregate obtained by firing a mixture of a porcelain clay and a predetermined pigment, wherein the titanium oxide content in the aggregate composition after firing is 0.15% by weight or less. A colored artificial aggregate for roads and building materials, having a dense structure having a water absorption of 2.0% or less. 2. The content of titanium oxide in the fired product is 0.15.
A raw material having a low content of titanium oxide is blended so as to be less than or equal to% by weight to prepare a porcelain clay, while a predetermined pigment is blended into the porcelain clay, and the average particle diameter is reduced to 300 μm or less. After being pulverized and mixed so as to form a molded product having a predetermined size, the molded product is further calcined to form a calcined product having a dense structure having a water absorption of 2.0% or less. Production method of colored artificial aggregate for road and building materials. 3. The ceramic porcelain clay comprises: (a) a SiO ₂ source material selected from the group consisting of silica, kaolin, clay, feldspar, pottery stone, and pyroxene; and (b) alumina, kaolin, and clay. and Al ₂ O ₃ source material selected from the group consisting of shale, (c) clay, bentonite, roads according to claim 2, which is mainly composed of a plasticizing component selected from the group consisting of montmorillonite and sericite -A method for producing colored artificial aggregate for building materials.