JP6384717B2 - Concrete coloring agent, concrete coloring method, concrete and concrete structure - Google Patents

Description

  The present invention relates to a concrete colorant, a concrete coloring method, a structure made of concrete and concrete.

  In recent years, the unique colors and textures of wood transferred to concrete bring out natural-looking aesthetics and warmth, so that there are an increasing number of buildings and structures made of wood-like makeup.

  With respect to natural-looking makeup finishes for buildings and structures, various methods and coating agents to be used have been proposed for enhancing the color and texture after finishing. For example, in Patent Document 1, a coating agent containing a synthetic resin emulsion and a granular material having an average particle diameter of 0.1 to 1.0 mm on a wall surface or the like and having a granular material content of 5 to 80% by mass is applied. After adding, it contains one or more kinds of powders selected from synthetic resin emulsion, natural stone having an average particle diameter of 5 μm to 3.0 mm, colored aggregate, and vegetable powder, and the solid content of the synthetic resin emulsion is 100 parts by weight. Distribute and apply a finish coating agent containing 100 to 1000 parts by weight of powder and granule, and give a pattern to the surface of the finish coating agent with a pattern roller before the finish coating agent is completely cured. A coating method is disclosed.

Further, for example, Patent Document 2 discloses a natural-tone cosmetic material produced by applying a coating agent on a pattern with uneven density and unevenness and a smooth portion and a rough surface portion formed on the surface of a mortar base material. It is disclosed.
Furthermore, for example, in Patent Document 3, a mold is formed using a template obtained by laminating a printing base paper on which a pattern is printed using ink having almost no water absorption on a plywood. A method for placing decorative concrete is disclosed in which concrete is poured to form a concrete surface having a density corresponding to the printing of a pattern.

JP 2008-253913 A JP-A-1-127330 JP-A-62-227800

  However, in natural finishes, not only the surface irregularities and patterns, but also the aesthetics and warmth brought out from the concrete members change depending on the color. In conventional concrete finishing methods and coatings, the color of the concrete after makeup finishing is easily affected by the mixing conditions of the concrete and the coating agent and during construction, and the colors such as yellow and green that produce a wood-like texture There was a problem that the surface did not settle stably and the finish was different from the designer's intention. There is also a problem that there is little academic knowledge about the color after the makeup finish, and the reproducibility of the color depends largely on the experience of the workers.

  The present invention has been made in view of the above circumstances, and is a concrete colorant capable of being colored in a natural wood-like texture, a concrete coloring method using the colorant, concrete colored by the method, and the method It is an object of the present invention to provide a structure made of concrete colored by the above.

(1) A concrete colorant comprising a phenolic compound represented by the following general formula (P1).

[Wherein, R represents an n-valent organic group, m represents an integer of 1 to 5, and n represents an integer of 1 or more.
]

  According to the concrete colorant of (1) above, the phenolic compound can be adhered to the concrete surface, and the surface of the concrete can be colored to the texture of wood.

(2) The concrete colorant as described in (1) above, wherein the phenolic compound is at least one of lignin and tannin.
According to the concrete colorant of the above (2), it is possible to color a more natural wood texture by taking advantage of the color of wood of at least one of lignin and tannin attached to the concrete surface.

(3) The concrete colorant as described in (1) above, wherein the phenolic compound is gallic acid.
According to the concrete colorant of (3) above, it is possible to color a more natural wood texture by taking advantage of the color tone of the wood of gallic acid attached to the concrete surface.

(4) The concrete colorant as described in (1) above, wherein the phenolic compound is at least one of quercetin and humic acid.
According to the concrete colorant of (4) above, it is possible to color a more natural wood texture by taking advantage of the color tone of at least one of quercetin and humic acid attached to the concrete surface.

(5) The concrete colorant as described in (1) above, wherein the phenolic compound further contains tannin and one or more selected from lignin, quercetin and humic acid.
According to the concrete colorant of the above (5), it is possible to color a more natural wood texture by taking advantage of the interaction of the color tone of the plurality of phenolic compounds.

(6) The concrete colorant according to any one of (1) to (3), wherein the phenolic compound is a compound extracted by immersing wood in an aqueous solvent.
According to the concrete colorant of the above (6), a pigment containing a plurality of types of compounds extracted from actual wood can be attached to the concrete surface to color the texture of the wood more naturally.

(7) The concrete colorant as described in (6) above, wherein the wood is immersed in an aqueous solvent having a pH of 4 or more.
According to the concrete colorant of (7) above, more natural wood can be obtained by adhering to the concrete surface pigments composed of a plurality of compounds having excellent color developability extracted from actual wood using an aqueous solvent having a pH of 4 or higher. The texture can be colored.

(8) The concrete colorant as described in (6) or (7) above, wherein the wood is cedar, lawan or larch.
According to the concrete colorant of (8) above, the surface of the concrete can be colored with a texture relatively close to that of the raw material wood, making use of the color tone of the wood of cedar, lauan or larch.
(9) A concrete coloring method, wherein the concrete colorant according to any one of (1) to (8) is adhered to a concrete surface.
(10) The concrete coloring method according to (9), wherein a surface layer portion of the concrete is maintained alkaline.
(11) The concrete coloring method according to (9), wherein a surface layer portion of the concrete is maintained at an alkaline pH of 10 or more.
(12) When placing the concrete using a form having a phase shape, the concrete colorant is placed after being attached to a surface of the form on which the concrete is placed. The concrete coloring method according to any one of (9) to (11).
(13) A concrete characterized by being colored by the concrete coloring method according to any one of (9) to (12).
(14) A structure made of concrete colored by the concrete coloring method according to any one of (9) to (12).

According to the concrete colorant and the concrete coloring method of the present invention, the surface of concrete can be colored easily and stably with high reproducibility in the texture of wood.
Although the concrete of the present invention and the structure made of the concrete are made of concrete, the surface thereof is colored with the texture of wood, so that it can give the viewer the natural aesthetics and warmth of wood. it can.

It is a schematic diagram which shows the concrete member colored by 1st embodiment of the concrete coloring method of this invention. It is a figure which shows 1st embodiment of the concrete coloring method of this invention, Comprising: It is a schematic diagram which shows a mode that concrete was laid in the formwork. It is a figure which shows 1st embodiment of the concrete coloring method of this invention, Comprising: It is a schematic diagram which shows a mode that a concrete colorant is apply | coated to the surface of a concrete member. It is a schematic diagram which shows the concrete member colored by 2nd embodiment of the concrete coloring method of this invention. It is a figure which shows 2nd embodiment of the concrete coloring method of this invention, Comprising: It is a schematic diagram which shows the formwork for placing concrete. It is a figure which shows 2nd embodiment of the concrete coloring method of this invention, Comprising: It is a schematic diagram which shows a mode that a concrete member is formed. 2 is a photograph of a scanning electron microscope showing a cross section of a specimen in Example 1. FIG. It is a figure which shows element distribution of the measurement surface of the test body in Example 1, Comprising: (a) is a figure which shows calcium element distribution, (b) is a figure which shows carbon element distribution. It is a graph which shows the total amount of organic carbon extracted from each of the non-colored part and the colored part of the test body in Example 1 to pH adjusted aqueous solution. 2 is a graph showing the absorbance of an extraction solution obtained from a cedar piece in Example 1. FIG. 6 is a plan view showing a test body in Example 2. FIG. It is a graph which shows the relationship between b ^* of the coloring surface of the concrete member produced in Example 4, and the density | concentration of the tannin contained in a concrete colorant. It is a graph which shows the relationship between L ^* of the coloring surface of the concrete member produced in Example 5, and the density | concentration of phenolic compounds other than the tannin added to the concrete colorant. It is a graph which shows the relationship between a ^* of the coloring surface of the concrete member produced in Example 5, and the density | concentration of phenolic compounds other than the tannin added to the concrete coloring agent. It is a graph which shows the relationship between b ^* of the coloring surface of the concrete member produced in Example 5, and the density | concentration of phenolic compounds other than the tannin added to the concrete colorant.

<Concrete colorant>
Embodiment of the concrete colorant which concerns on this invention contains the phenolic compound represented by the following general formula (P1). In general formula (P1), R represents an n-valent organic group, m represents an integer of 1 to 5, and n represents an integer of 1 or more. R is bonded to n phenolic hydroxyl groups.

  The mechanism by which the concrete colorant according to the present invention can be colored to a color close to natural wood by adhering the concrete colorant to the concrete surface is not necessarily clear, but the phenolic compound contained in the concrete colorant and / or its It is presumed that the hydrolyzate binds iron (iron ions) or other metal components present on the concrete surface to form a complex and becomes a pigment close to natural wood. Therefore, the phenolic compound represented by the general formula (P1) (hereinafter sometimes referred to as “compound P1”) only needs to have a phenolic hydroxyl group capable of binding iron or other metal components. . Here, the phenolic hydroxyl group means a group represented by the following general formula (q1). In general formula (q1), m represents an integer of 1 to 5, and a bond separated by a wavy line represents a monovalent bond.

  R in the general formula (P1) may be an n-valent organic group, and the number of carbon atoms of the organic group is not particularly limited, but is preferably 1 to 1000, for example. The organic group is preferably a hydrocarbon group, and more preferably a compound in which a hydrogen atom constituting a linear, branched or cyclic alkane is substituted with a phenolic hydroxyl group. In general formula (P1), n represents the number of phenolic hydroxyl groups. n should just be a natural number, for example, it is preferable that it is an integer of 1-100. When n is 2 or more, m in the plurality of phenolic hydroxyl groups represented by the general formula (q1) each independently represents 1 to 5, and each m is preferably 1 to 3 independently.

  Among the alkanes, a part of the alkylene group constituting the linear alkane may be substituted with a cyclic alkylene group or a phenylene group, and a part of the alkylene group constituting the branched chain alkane is a cyclic alkylene group or phenylene. It may be substituted by a group. Any or all of the hydrogen atoms constituting the cyclic alkylene group and the phenylene group are any of a hydroxyl group (—OH), a carboxyl group (—C═O—OH), an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. One or more may be substituted. In addition, the branched chains of the branched chain alkane are bonded to each other through one or more divalent linking groups selected from a single bond, an oxygen atom (—O—), and an alkylene group having 1 to 5 carbon atoms. A typical ring may be formed. In this case, it is preferable that the terminal hydrogen atom constituting the branched chain is substituted with the divalent linking group.

The methylene group (—CH ₂ —) constituting the alkane is substituted by one or more of an oxygen atom (—O—), a carbonyl group (—C═O—), or a vinylene group (—CH═CH—). May be. Further, the hydrogen atom constituting the alkane, the alkylene group or the phenylene group is any one of a hydroxyl group (—OH), a carboxyl group (—C═O—OH), an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. Or may be substituted by one or more.

  Suitable compounds P1 include, for example, catechin generally contained in various kinds of wood, quercetin which is a kind of flavonoid, humic acid (humic acid), lignin and tannin. By including any one or more of catechin, quercetin, humic acid, lignin and tannin in the concrete colorant, the color tone of wood possessed by catechin, lignin, quercetin, humic acid and tannin attached to the concrete surface Utilizing this, the concrete surface can be colored with a more natural wood texture.

Here, “tannin” is a term that includes catechin, tannic acid, gallic acid, and the like, and is a general term for water-soluble compounds that are generally derived from plants, and is hardly soluble by reacting with metal ions, alkaloids, proteins, and the like. A salt, complex, or compound that forms a complex. “Catechin” is a known compound represented by a composition formula of C ₁₅ H ₁₄ O ₆ , and here is a term including a polyphenol compound as a derivative thereof. “Lignin” is a known aromatic polymer compound known as a phenolic compound involved in lignification of higher plants. “Flavonoids” are naturally occurring organic compounds having a flavan structure as a basic skeleton, and many flavonoids generally have phenolic hydroxyl groups.

  Further, tannic acid and gallic acid represented by the following formula can also be exemplified as suitable compounds P1. By including tannic acid and / or gallic acid in the concrete colorant, the concrete surface can be made more natural to the texture of the wood by taking advantage of the color of the timber and / or gallic acid adhering to the concrete surface. Can be colored.

  An ester compound of gallic acid can also be used as compound P1. Examples of such ester compounds include propyl gallate, isoamyl gallate, and epigallocatechin gallate.

  When the tannic acid is contained in the concrete colorant, the concentration thereof is not particularly limited. For example, 0.1 to 40% by mass is preferable with respect to the total mass of the colorant, and 1 to 20% by mass is more preferable. 10 mass% is still more preferable.

  When gallic acid is contained in the concrete colorant, the concentration is not particularly limited, but is preferably 0.1 to 40% by mass, more preferably 1 to 20% by mass with respect to the total mass of the colorant, and 1 to 10 mass% is still more preferable.

  The concrete colorant preferably contains at least one of lignin and tannin, more preferably both lignin and tannin. By blending lignin and tannin, a more natural wood texture can be colored. Although the blending ratio of lignin and tannin is not particularly limited, for example, 1 to 10 parts by mass of tannin is preferably blended with respect to 1 part by mass of lignin.

  When the concrete colorant contains one or more selected from quercetin and humic acid, it is preferably included together with one or more selected from lignin and tannin. With this combination, a more natural wood texture can be colored.

  The solvent constituting the concrete colorant is not particularly limited as long as it can dissolve or disperse the compound P1, and may be an aqueous solvent or an organic solvent.

  The aqueous solvent is not particularly limited as long as it is a solution containing water as a main component and containing 50% by mass or more of water with respect to the total mass of the solvent. For example, it may be purified pure water, an aqueous solution containing an acid or alkali, or a known pH buffer solution containing a pH-adjustable buffer. Moreover, organic solvents, such as alcohol miscible with water, may be included.

  The concrete colorant of this embodiment may be prepared by dissolving or dispersing chemically synthesized compound P1 in an appropriate solvent, or using compound P1 extracted from natural wood as an appropriate solvent. It may be prepared by dissolving or dispersing.

  For example, by immersing wood in an aqueous solvent, a plurality of types of compounds including the compound P1 can be extracted into the solvent. Such compounds may include unidentified compounds in addition to phenolic compounds such as tannic acid and gallic acid. By attaching a pigment composed of a compound extracted from wood to the concrete surface, it is possible to color the texture of wood more naturally.

  The pH of the aqueous solvent in which the wood is immersed is preferably 4 or higher, more preferably 7 or higher, and still more preferably 9 or higher. The compound P1 extracted with an aqueous solvent having a pH of 4 or more has excellent color developability and can color the concrete surface as if it were wood. In addition, the wood-derived compound P1 extracted with an alkaline aqueous solvent is particularly excellent in color developability.

  The kind of the wood immersed in the aqueous solvent for extracting the compound P1 is not particularly limited, and a known wood containing lignin or tannin can be used. For example, by using cedar, lawan, larch, etc., a compound capable of coloring the concrete surface in a color having excellent aesthetics can be extracted.

  Further, the wood to be used may be raw wood (undried raw wood) or dry wood. If wood is previously crushed into fine chips, the extraction efficiency of phenolic compounds can be increased.

The time for immersing the wood in the solvent to extract the compound P1 is not particularly limited, and can be extracted in about 1 hour to 10 days, for example.
The temperature of the solvent in which the wood is immersed for extracting the compound P1 is not particularly limited, and can be extracted at, for example, about 10 to 60 ° C.

<Concrete coloring method>
Hereinafter, an embodiment of a concrete coloring method according to the present invention will be described.
The concrete coloring method of this embodiment attaches the above-mentioned concrete coloring agent containing the phenolic compound to the surface of the concrete used for the building or structure, so that the phenolic compound (compound P1) is present on the concrete surface and in the vicinity of the surface. ) To color the concrete surface.
Here, “attaching” a concrete colorant is a term including “applying”, “impregnating”, and “transferring”.

(First embodiment)
As shown in FIG. 1, the decorative concrete 2 manufactured using the concrete coloring method of the present embodiment has a natural tone (not shown) on the decorative surface 4 a (surface) of a concrete member 4 (concrete) constituting a building or structure. A concrete colorant containing a phenolic compound (i.e., compound P1) that emits the following color is applied. The concrete colorant has also penetrated into the concrete member 4 on the inner side of the fixed thickness dimension from the decorative surface 4a. In the concrete member 4, the decorative surface 4 a and a portion impregnated with the compound P <b> 1 having a certain thickness inside from the surface are referred to as a colored layer 4 d. The thickness dimension of the colored layer 4d is about 400 μm.

  Examples of the material of the concrete member 4 include ordinary Portland cement, moderately hot Portland cement, low heat Portland cement, early-strength Portland cement, blast furnace cement, and silica fume premix cement. There is no particular limitation as long as it is mortar or concrete.

<Formation of concrete member 4>
As shown in FIG. 2, first, a mold 10 made of wooden plywood, steel, resin or the like that matches the size of the concrete member 4 is assembled. The rectangular mold 10 shown in FIG. 2 is an example, and other shapes may be used. Next, concrete 12 constituting the concrete member 4 is placed in the mold 10 and solidified. The age of the concrete 12 is preferably set as appropriate in consideration of the type of the concrete 12 used, the strength required for the concrete member 4, the color of the finished decorative concrete 2 and the like. Thereafter, the concrete member 4 is manufactured by removing the mold 10.

<Coloring of concrete member 4>
Subsequently, as shown in FIG. 3, the concrete colorant 13 described above is applied to the decorative surface 4a of the concrete member 4). In addition, since a high concentration lignin may suppress solidification of the concrete 12, it is preferable that the amount of lignin contained in the concrete colorant 13 is an amount that does not inhibit the solidification of the concrete 12.

  The method for applying the concrete colorant 13 to the decorative surface 4a of the concrete member 4 is not particularly limited. For example, a method of applying the concrete colorant 13 to the decorative surface 4a of the concrete member 4 using a brush or the like can be employed. In addition, as another method of applying the concrete colorant 13 to the concrete member 4, there is a method of placing the concrete 12 after applying the concrete colorant 13 to the surface of the mold 10 that contacts the decorative surface 4 a. An example of this method will be described later as a second embodiment.

Next, the concrete colorant 13 applied to the decorative surface 4a is dried. In order to suppress the color change of the decorative surface 4a of the concrete member 4, the decorative surface 4a of the concrete member 4 (that is, the dried concrete colorant 13) is preferably within 7 days after the applied concrete colorant 13 is dried. It is preferable to apply clear to the above.
The decorative concrete 2 is completed through the above steps.

  According to the concrete coloring method of this embodiment, the concrete coloring agent 13 is applied to the decorative surface 4a of the concrete member 4, and the decorative surface 4a of the concrete member 4 is easily and easily adhered to or penetrated from the concrete surface. It is possible to stably color the natural tone of the wood and enhance the aesthetics and the warmth brewed from the decorative concrete 2.

  Further, by making the surface layer portion of the concrete member 4 alkaline, preferably by adjusting the pH to 10 or more, the coloring of the compound P1 such as tannin and lignin becomes darker, and the decorative surface 4a of the concrete member 4 is colored with good coloring. It becomes possible to do. Since concrete is essentially alkaline, the surface layer is coated with clear (transparent surface coating material) so that the surface layer is not neutralized by carbon dioxide in the air. Part can be kept alkaline.

(Second embodiment)
FIG. 4 is a schematic diagram showing decorative concrete 3 manufactured using the concrete coloring method of the present embodiment. In addition, the same code | symbol is attached | subjected to the component same as the decorative concrete 2 of 1st embodiment among the components of the decorative concrete 3 shown in FIG. 4, and the description is abbreviate | omitted.

As shown in FIG. 4, in the decorative concrete 3, a concrete colorant is applied to the decorative surface 4a of the concrete member 4, the compound P1 penetrates into the colored layer 4d, and the decorative surface 4a has a wood tone (like wood). The concavo-convex pattern is formed. Due to the unevenness of the wood tone, the decorative concrete 3 further exudes aesthetics and warmth peculiar to wood.
Hereinafter, the manufacturing method of the decorative concrete 3 of 2nd embodiment is demonstrated.

<Formation of concrete member 4>
First, as shown in FIG. 5, a mold 10 that matches the size of the concrete member 4 is assembled. At this time, as a bottom plate of the mold 10, a wooden mold (wood) 14 having a wood-like uneven pattern facing the inside of the mold 10 is installed. As the side plate of the mold 10, a wooden mold 14 similar to the bottom plate may be used, or a mold material made of steel or resin may be used. Note that the bottom plate of the mold 10 is not necessarily made of wood, and may be made of synthetic rubber other than wood, metal, or the like as long as it has a phase shape.

  Here, the “phase shape” means an uneven shape capable of imparting desired unevenness to the decorative surface of the concrete to be placed. For example, when a bottom plate having wood-like irregularities is used, the surface of the concrete placed in contact with the bottom plate is transferred with irregularities in which the irregularities of the bottom plate are inverted, and the makeup has wood-like irregularities. A surface can be formed.

  Next, as shown in FIG. 6, the concrete 12 constituting the concrete member 4 is placed in the mold 10 and solidified (cured). The kind of concrete used here is not particularly limited. The age of the concrete 12 is preferably set appropriately in consideration of the type of the concrete 12 used, the strength required for the concrete member 4, the color of the finished decorative concrete 3 and the like.

  The concrete member 4 is manufactured by removing the mold 10 after the concrete 12 is solidified. As a result, as shown in FIG. 6, the wood-like uneven pattern is transferred to the surface 12 p of the concrete 12 in contact with the wooden formwork (bottom plate) 14 of the formwork 10, and the surface is applied to the decorative surface 4 a of the concrete member 4. It can be.

<Coloring of concrete member 4>
Subsequently, the concrete colorant 13 is applied to the decorative surface 4 a of the concrete member 4. The coating method and the drying method can be performed in the same manner as described in the first embodiment.

Further, as a concrete coloring method in the present embodiment, a concrete colorant 13 may be applied in advance to the surface of the mold (bottom plate) 14 in contact with the concrete 12 before the concrete 12 is placed on the mold 14. Good. By this method, the color derived from the compound P1 contained in the concrete colorant is transferred to the surface 12p of the concrete 12 in contact with the formwork 14 at the same time as the wood-like uneven pattern. Therefore, immediately after demolding, the concrete colorant 13 is applied to the decorative surface 4a of the concrete member 4 (attached state), and the coloring process of the concrete member 4 after demolding becomes unnecessary.
The decorative concrete 3 is completed through the above steps.

  According to the concrete coloring method of this embodiment, the concrete coloring agent 13 is applied to the decorative surface 4a of the concrete member 4, and the decorative surface 4a of the concrete member 4 is easily and easily adhered to or penetrated from the concrete surface. It is possible to stably color the natural tone of wood and enhance the aesthetics and the warmth brewed from the concrete. Further, by making the surface layer portion of the concrete member 4 alkaline by using the same method as in the first embodiment, the coloring of the compound P1 such as tannin and lignin becomes dark, and the decorative surface 4a of the concrete member 4 has a good coloring property. It becomes possible to color.

  Further, according to the concrete coloring method of the present embodiment, the concrete member 4 is formed by placing the concrete 12 on the formwork 10 using the wooden formwork 14 having a phase shape. By forming a concavo-convex pattern peculiar to wood on 4a, it becomes possible to further enhance the aesthetics and the warmth brought out from the decorative concrete 3.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. It can be changed.

  Next, the present invention will be described in detail by the following examples, but the present invention is not limited only to these examples.

Example 1
First, a cedar plate having a length of 300 mm and a width of 100 mm was used as a bottom plate, and a side plate corresponding to the bottom plate was prepared to assemble a formwork made of wood. A concrete colorant 13 containing a phenolic compound (compound P1) extracted from a cedar wood piece into an aqueous solvent is applied to the concrete placing surface of the bottom plate, and the water cement ratio is set to 50%. Portland cement (hereinafter referred to as “N50”) was cast and demolded at a material age of 3 days as a test specimen. The used N50 was kneaded until kneading was not observed after kneading. Along with the specimen, a cedar material of the same type as the cedar plate used for the bottom plate of the mold was prepared as a reference sample.

Next, using the surface that was in contact with the bottom plate of the mold as the measurement surface, color measurement was performed on the measurement surface of the specimen immediately after demolding. For the color measurement, a color difference meter (model number: CR-410, manufactured by Konica Minolta) was used. Further, the color change was evaluated by L ^* , a ^* , b ^{* of the} CIE 1976 color space. Table 1 shows the measurement results of the hues of the measurement surfaces of the uncolored N50 and the test body of this example immediately after demolding. Note that, in the test body of the present example, the hue varies depending on the measurement location, so Table 1 shows the average value of the measurement values at 12 locations on the measurement surface.

From the results of Table 1, it was confirmed that the lightness L ^* was decreased and b ^* was significantly increased on the measurement surface of the test body coated with the concrete colorant. As a result, it was confirmed that the measurement surface of the specimen was finished in yellowish gray. Since the measured colored surface is colored in the texture of wood, it was possible to give the viewer the natural aesthetics and warmth unique to wood.

Next, cross-sectional observation near the measurement surface of the specimen was performed using a scanning electron microscope (SEM).
FIG. 7 shows a cross-sectional photograph by SEM, and FIG. 8 shows the results of measurement of calcium element distribution and carbon element distribution in the vicinity of the measurement surface. As can be seen from FIG. 7, there was a difference in image density between the test piece inside the thickness of about 400 μm from the surface layer of the measurement surface and the test piece inside. Regarding the difference in light and shade, the element mapping results shown in FIG. 8 show that a large amount of carbon element is distributed on the surface layer of the measurement surface of the test body, and the amount of calcium element is small compared to the test body inside the surface layer. It can be seen that it is distributed. That is, the difference in light and shade in FIG. 7 is presumed to be caused by the difference in carbon element concentration and calcium element concentration in the test specimen. Although calcium element is derived from cement, supply of carbon element (compound P1) from the concrete colorant is considered as a factor that causes a change in the carbon element concentration due to the thickness dimension from the surface layer of the measurement surface of the specimen. It is done. From these results, it was confirmed that the discoloration on the measurement surface of the test specimen was caused by a substance containing a large amount of carbon element. Further, in this example, the range from the measurement surface of the specimen to the inside of the thickness dimension of about 400 μm was colored.

Next, a part was sampled from the colored portion in the vicinity of the measurement surface of the test body and the non-colored portion inside the test body to obtain a colored sample and a non-colored sample, respectively. Then, JIS K for colored and non-colored samples
An acid-alkali aqueous solution extraction experiment was conducted with reference to the chemical substance test method for slags of 0058-1. Specifically, each sample and an acid-alkali aqueous solution were mixed at a weight volume ratio of 1:10 and shaken for 6 hours. After extraction, the suspension was centrifuged at 2000 rpm for 10 minutes, and the supernatant was filtered through a 0.45 μm filter. Thereafter, the pH of the filtrate, the amount of total organic carbon (TOC) and the absorbance were measured using a commercially available pH electrode and TOC meter, and a spectroscopic analyzer (model number: U-2000, manufactured by Hitachi, Ltd.). It was measured.

  Moreover, acid-alkaline aqueous solution extraction experiment was done also with respect to the cedar board prepared as a reference sample with reference to the chemical substance test method of slag of JISK0058-1. At this time, the cedar plate was molded into a size of 20 mm long × 80 mm wide × 13 mm thick (hereinafter referred to as a cedar piece). As the acid-alkali aqueous solution, an aqueous solution prepared by mixing sulfuric acid and calcium hydroxide solution in pure water so that the pH was 4, 7, 9, 10, 11, 12 was used. Moreover, extraction of organic substances such as compound P1 from cedar pieces was performed by placing cedar pieces and 250 mL of acid-alkali aqueous solution in a polypropylene container with a cap and immersing them for one week. Since the cedar pieces floated in the acid-alkali aqueous solution during the immersion period, the polypropylene container was inverted every other day. After the immersion period, the extract was filtered through a 0.45 μm filter, and then the pH, TOC amount, and absorbance of the filtrate were measured by the same method as the acid-alkali aqueous solution extraction experiment on the colored and non-colored samples.

  In FIG. 9, the measurement result of the amount of TOC for every pH of a colored sample and a non-colored sample is shown. As shown in FIG. 9, it was confirmed that the colored sample contained about 5 times the TOC compared to the non-colored sample. This result is in agreement with the SEM measurement result of FIG. 7, and it can be estimated that the discoloration of the test specimen is due to the organic matter derived from cedar contained in the concrete colorant, that is, the compound P1. Focusing on the effect of the pH of the filtrate on the amount of TOC, although the amount of TOC was high when the pH was 11, there was no significant difference between the case where the pH was 7 and the case where it was 4. .

  After the acid / alkaline aqueous solution extraction experiment, when the pH of the solution obtained by filtering the colored sample and the non-colored sample was measured, it changed from pH 4 to pH 12.6, from pH 7 to pH 12.6, and from pH 12 to pH 12.7. It was found that the pH of the solution was increased by the influence of calcium hydroxide contained in the cement of the test specimen.

Next, the color of the organic matter extracted from the cedar pieces into the acid-alkali aqueous solution was visually observed. As a result, it was confirmed that the brown color derived from the cedar was darker as it was immersed in the solution having a higher pH.
Possible causes of the change in color shade due to pH are both the change in the color of the extracted substance itself and the increase in the concentration of the extracted substance. Therefore, by using a pH 12 extraction solution and adding a strong acid, the concentration of the solution was hardly changed, and only the pH was changed and the color of the solution was visually observed. As a result, the color of the solution lightened as the pH decreased. Since the total amount of the solution is hardly changed, the extracted substance shows a different color depending on each pH. Further, this color reaction was reversible, and when the pH was changed again from a low pH to a high pH, the color of the solution became darker. As a result, the colored portion of the test specimen contains about 5 times as much organic matter as the inside, and the degree of coloration of the solution extracted from the cedar pieces varies depending on the pH and is highly alkaline as in cement. As a result, it was confirmed that the color was darker.

  Then, the measurement result of the wavelength dependence of the light absorbency in the extraction solution of a cedar piece is shown in FIG. As shown in FIG. 10, the absorbance peak at a wavelength of 270 nm was confirmed in the solutions extracted at pH 4 and pH 7, but the absorbance peak at the same wavelength was small in the extracted solution at pH 12. This absorbance peak is unique to tannin, and it was confirmed that tannin was contained in the extracted solution of cedar pieces. Tannin has the property of browning in an alkaline environment, and this property has been confirmed by observation of the color of the extract. From the above, it can be said that tannin is one of the substances that discolor the specimen naturally. On the other hand, lignin contained in a large amount in wood shows a relatively dark brown color at any pH and has a great influence on the color of concrete after coloring. Therefore, it is considered that the surface of concrete can be discolored even with a small amount.

  When concrete is cast using a formwork made of wood as in this embodiment, the wood grain of the wood is transferred to the surface of the concrete in contact with the wood. However, the irregularities on the surface of the cedar plate are expected to vary greatly depending on the individual cedar plate, and variations due to processing when floating is produced. For this reason, the height difference between summer and winter transferred to the specimen is not limited to the above values.

  As shown in Example 1, in addition to the measurement surface of the test body being colored, the unevenness pattern of summer eyes and winter eyes is formed on the measurement surface, so that the natural tone brought out from the test body is obtained. It is thought that aesthetics and warmth are enhanced.

(Example 2)
A form using cedar wood was prepared on the surface where the concrete to be placed touches. Moreover, 1 mass%, 5 mass%, 10 mass% tannic acid aqueous solution and 10 mass%, 50 mass%, and 100 mass% lignin aqueous solution or lignin liquid were prepared as concrete colorants, respectively. The tannic acid and lignin used here are commercially available products that can be purchased as reagents. Subsequently, tannic acid aqueous solution and lignin aqueous solution of each concentration were respectively applied to the surface where the mold and the concrete contacted, and ordinary concrete was cast. Each concrete was demolded at a dry material age of 1 day to obtain test bodies B to G. Further, a test specimen A prepared by placing ordinary concrete without applying any concrete colorant of tannic acid aqueous solution and lignin aqueous solution to the mold and demolding at a dry material age of 1 day was prepared.

In each of the test bodies A to G, the surface layer portion of the concrete in contact with the bottom surface of the mold is divided into six sections a to f as shown in FIG. 11, and the center portion of each section (the position of the X mark in FIG. 11). ) L ^* , a ^* , b ^* . Table 2 shows the average values of the measured values at the center of the sections a to f for each of L ^* , a ^* , and b ^* .

As shown in Table 2, it can be seen that the value of b ^* of the test specimens B to G is larger than that of the test specimen A, and it is colored in a natural tone by tannin or lignin.

(Example 3)
As a concrete sample before coloring, a disc-shaped white plate made of ordinary Portland cement and having a diameter of 30 centimeters was prepared by a conventional method. When this tannic acid aqueous solution containing tannic acid at a concentration of 5 to 10% by mass was applied to the white plate and dried, the applied portion could be colored in a wood-like brown color. Moreover, when tannic acid was changed to gallic acid and the same test was conducted, it was possible to color the wood-like brown with a texture different from that of tannic acid.

(Reference experiment)
When iron sulfate was dissolved in the tannic acid aqueous solution, it was confirmed that the color of the tannic acid aqueous solution changed from light brown to dark brown. Similarly, when iron sulfate was dissolved in a gallic acid aqueous solution, it was recognized that the color of the gallic acid aqueous solution changed from light brown to dark brown. This color change is considered to be due to the formation of a complex between each compound and / or its hydrolyzate and iron ions in an aqueous solution.

Example 4
First, the formwork was assembled by using as a base plate a plate having rubber wood grain irregularities (having a phase shape) of 300 mm in length and 100 mm in width, and using a wooden plate matched to the bottom plate as a side plate.
Subsequently, ordinary concrete (N50) was placed in the above mold. The concrete was demolded at a dry material age of 4 days, and dried for about 2 days to 1 week to obtain a concrete member having grainy irregularities (irregularities with inverted bottom plate irregularities) on the surface. By using a rubber bottom plate, a beautiful finished surface without fluttering was obtained.

  Next, an aqueous tannic acid solution prepared in 1% increments in the concentration range of 1 to 10% by mass was applied to the surface to give a wood-like brown color. Color measurement was performed on each colored portion colored with a tannic acid aqueous solution of each concentration. In each colored portion, measurement was performed at 10 locations, and the average value was obtained. The color measurement was evaluated by the color space of CIE1976 as in Example 1.

Of the above measurement results, FIG. 12 shows b ^* that more reflects the color tone of wood. The dotted line in FIG. 12 is b ^* of the test body of Example 1, and is a reference for evaluating this example.
Moreover, the result (Table 1) of Example 1 and the result of using the 5 mass% tannic acid aqueous solution in a present Example are written together in the following Table 3.

From the above results, it was found that when an aqueous tannic acid solution is used as a concrete colorant, it is possible to perform coloring with a warmness close to that of natural wood. Unlike the coloring using a conventional inorganic pigment, this coloring is excellent in that it is not monotonous and does not have an inorganic hue because of its unique unevenness. From the results shown in FIG. 12, it was found that the tannic acid concentration is preferably 3 to 7% by mass when colored so as to have a b ^{* of the} same level as in Example 1 using the cedar board as the bottom plate of the formwork. .

(Example 5)
As phenolic compounds P1 other than tannic acid, phenolic compounds having absorption maxima in the ultraviolet region of 230 nm and 275 nm, which are easy to extract from wood with chloroform-methanol mixed solvent, and absorption maxima at 265 nm and 320 nm, easy to extract from wood with methanol It is also possible to use a phenolic compound having an absorption maximum at 265 nm and 350 nm that can be easily extracted from wood with a methanol-water mixed solvent. Examples of such phenolic compounds include lignin, flavonoids, and humic acids. Examples in which these compounds are used in combination with tannic acid are shown below.

  In this example, in addition to 5% by mass of tannic acid, three types of lignin (manufactured by Nippon Paper Industries Co., Ltd.), quercetin (manufactured by Wako Pure Chemical Industries, Ltd.), humic acid (manufactured by Wako Pure Chemical Industries, Ltd.) Any one was selected, and a plurality of aqueous solutions added by changing the concentration range of the selected compound were prepared as concrete colorants.

The concrete colorant prepared above was applied to the surface of the concrete member obtained by the same method as in Example 4 and colored. The color of the colored surface was measured in the same manner as in Example 4. About this measurement result, the graph which shows the relationship between the density | concentration of phenolic compounds other than tannic acid added to the concrete colorant, and each of L ^* , a ^*, and b ^* of color space is shown in FIGS.
In each graph, the dotted line is the result of L ^* , a ^* or b ^* of the test specimen of Example 1, and is a reference for evaluating this example. Moreover, in each graph, B, P, and S are commercially available lignins called vanillex, pearl rex, and sun extract, K is commercially available quercetin, and F is commercially available humic acid. Since the solubility of quercetin and humic acid in water was low, the concentration was kept at a maximum of 1% by mass.

  From the above results, it was confirmed that the texture of wood can be colored by the concrete colorant containing lignin, quercetin or humic acid together with tannic acid, as in the case of Example 1 using the cedar board as the bottom plate of the formwork. . In particular, when lignin was used, the beautiful texture of the wood increased further, and it was possible to reproduce the same hue as when colored using a cedar board on the bottom plate of the formwork.

2 ... decorative concrete, 3 ... decorative concrete, 4 ... concrete member (concrete), 4a ... decorative face, 4d ... colored layer, 10 ... formwork, 12 ... concrete, 12p ... concrete surface, 13 ... concrete colorant, 14 ... Formwork with phase shape (wooden formwork)

Claims (13)

Concrete colorant you comprising a tannin. Concrete colorant you comprising a gallic acid. Concrete colorant comprising quercetin. The concrete colorant according to claim 1, further comprising at least one selected from lignin, quercetin and humic acid . A concrete colorant containing a phenolic compound represented by the following general formula (P1),
Concrete colorant characterized in that the phenolic compound is a compound that is extracted by dipping the lumber in an aqueous solvent.
[Wherein, R represents an n-valent organic group, m represents an integer of 1 to 5, and n represents an integer of 1 or more. ] The concrete colorant according to claim 5 , wherein the wood is immersed in an aqueous solvent having a pH of 4 or more. The concrete colorant according to claim 5 or 6 , wherein the wood is cedar, lawan or larch. A concrete coloring method, wherein the concrete colorant according to any one of claims 1 to 7 is adhered to a concrete surface. The method for coloring concrete according to claim 8 , wherein the surface layer of the concrete is maintained alkaline.   The concrete coloring method according to claim 9, wherein a surface layer portion of the concrete is maintained at an alkaline pH of 10 or more. When pouring the concrete using a mold having a phase shape, claim 8, characterized in that the pouring of the concrete colorant after deposition on a surface of pouring the concrete in the formwork The concrete coloring method as described in any one of ~ 10 . Concrete, characterized in that it is colored by a concrete coloring method according to any one of claims 8-11. A structure made of concrete colored by the concrete coloring method according to any one of claims 8 to 11 .