JP6296285B2 - How to protect concrete - Google Patents

Description

  The present invention relates to a method for protecting 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.

  Various methods for enhancing the color and texture of concrete after finishing have been proposed for the natural finish of buildings and structures. 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 particle content of 5 to 80% by weight 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. Furthermore, the change with time (discoloration) of the color after makeup finish may impair the aesthetics.

  The present invention has been made in view of the above circumstances, and provides a method for protecting concrete capable of protecting the surface of concrete colored in a natural wood-like texture and suppressing discoloration associated with changes over time. Is an issue.

(1) A step of attaching a concrete colorant containing a phenolic compound represented by the following general formula (P1) to the surface of concrete, and a step of applying clear to the surface to which the concrete colorant is attached. A method for protecting concrete, comprising:

[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 protection method of the above (1), the surface of the concrete colored like natural wood derived from a phenolic compound is protected, and the color of the protected concrete is suppressed by suppressing the fading accompanying the change with time. The aesthetics and warmth created from the surface can be maintained over a long period of time.

(2) The method for protecting concrete according to (1), wherein acrylic clear is used as the clear.
According to the protection method of (2) above, it is possible to deepen the texture like natural wood by applying clear, and to maintain the texture (color) stably over a long period of time.

(3) The method for protecting concrete according to (1) or (2), wherein clear is applied to the surface within 7 days of dry material age of the concrete.
According to the protection method of (3) above, before the decomposition of the phenolic compound with the progress of the drying material age and / or the discoloration (fading) of the phenolic compound accompanying the neutralization of the pH of the concrete surface, The surface to which the phenolic compound is attached can be protected by clearing. As a result, the texture can be maintained stably over a long period of time.

(4) The method for protecting concrete according to any one of (1) to (3), wherein the phenolic compound is lignin or tannin.
According to the protection method of (4) above, the lignin and tannin attached to the concrete surface can be used to express the texture of the wood more naturally, and the lignin and tannin can be reliably obtained by clearing. Therefore, the texture can be maintained stably over a long period of time.

(5) The method for protecting concrete according to any one of (1) to (3), wherein the phenolic compound is gallic acid.
According to the protection method of (5) above, it is possible to express a more natural wood texture by taking advantage of the wood color of the gallic acid attached to the concrete surface, and the gallic acid is reliably protected by clearing. Therefore, the texture can be maintained stably over a long period of time.

(6) The method for protecting concrete according to any one of (1) to (5), wherein the phenolic compound is a compound extracted by immersing wood in an aqueous solvent.
According to the protection method of (6) above, it is possible to express a more natural wood texture by making use of the color of the pigment containing a plurality of types of compounds extracted from actual wood attached to the concrete surface. In addition, since the pigment is reliably protected by clear, the texture can be maintained stably over a long period of time.

(7) The method for protecting concrete according to (6), wherein the wood is immersed in an aqueous solvent having a pH of 4 or higher.
According to the protection method of (7) above, taking advantage of the color tone of 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, which is attached to the concrete surface. Further, it is possible to express a more natural wood texture, and since the pigment is reliably protected by clear, the texture can be maintained stably over a long period of time.

(8) The method for protecting concrete according to (6) or (7), wherein the wood is cedar, lauan, or larch.
According to the protection method of (8) above, it is possible to express a texture that is relatively close to the raw material wood by utilizing the color tone of the pigment extracted from cedar, lauan, or larch attached to the concrete surface.

(9) The method for protecting concrete according to any one of (1) to (8), wherein unevenness of a wood pattern is formed on a colored surface of the concrete member.
According to the protection method of (9) above, the shade similar to the surface of natural wood appears due to the unevenness of the wood pattern (wood grain) formed on the colored surface as well as the color of the colored surface. The texture of wood can be expressed. In addition, the applied clear chemically protects the tint of the colored surface and also physically protects the irregularities that make up the wood pattern, so that the texture and wood pattern can be stably maintained over a long period of time. Can be maintained.
(10) Applying clear to the concrete surface to which the pigment | dye derived from the wood included in the said wooden formwork is made to adhere to the concrete surface by pouring concrete into a wood formwork, and the said pigment | dye adhered And a method for protecting concrete.
According to the protection method of (10) above, by attaching (transferring) a pigment derived from wood to the concrete surface, the concrete surface can be colored in a beautiful texture like wood, and the pigment is reliably protected by clearing. Therefore, the texture can be maintained stably over a long period of time.
(11) The method for protecting concrete according to (10), wherein acrylic clear is used as the clear.
According to the protection method of (11), it is possible to deepen the texture like natural wood by applying clear, and to maintain the texture (color) stably over a long period of time.
(12) The method for protecting concrete according to (10) or (11), wherein clear is applied to the surface within 7 days of dry material age of the concrete.
According to the protection method of (12) above, before the degradation of the phenolic compound with the progress of the drying material age and / or the discoloration (fading) of the phenolic compound with the neutralization of the pH of the concrete surface proceeds, The surface to which the phenolic compound is attached can be protected by clearing. As a result, the texture can be maintained stably over a long period of time.

  According to the protection method of the present invention, the surface of concrete colored in a texture like natural wood derived from a phenolic compound is protected, and the color fading accompanying the change over time is suppressed, thereby preventing the colored surface of the protected concrete. The aesthetics and warmth that are brewed can be maintained over a long period of time.

It is a schematic diagram which shows the concrete member protected by 1st embodiment of this invention. It is a figure which shows the method of protecting a concrete member in 1st embodiment 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 the method of protecting a concrete member in 1st embodiment 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 protected by 2nd embodiment of this invention. It is a figure which shows the method to protect a concrete member in 2nd embodiment of this invention, Comprising: It is a schematic diagram which shows the formwork for placing concrete. It is a figure which shows the method of protecting a concrete member in 2nd embodiment of this invention, Comprising: It is a schematic diagram which shows a mode that a concrete member is formed. 3 is a photograph of a scanning electron microscope showing a cross section of a specimen in Reference Example 1. It is a figure which shows element distribution of the measurement surface of the test body in the reference 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 colored part of the test body in Reference Example 1 to the pH adjusted aqueous solution. It is a graph which shows the light absorbency of the extraction solution obtained from the cedar piece in Reference Example 1. It is a graph which shows the influence of the kind of wooden board of a form form on the brightness of the concrete used for each concrete member in the comparative example 1. It is a graph which shows the influence of the kind of wooden board of a form form on b ^* of the concrete used for each concrete member in the comparative example 1. It is a graph which shows the change of b ^* with progress of dry material age of each concrete member in Example 1. FIG. It is a graph which shows the change of b ^* with progress of dry material age of each concrete member in Example 2. FIG. 10 is a plan view showing a test body in Reference Example 2. FIG.

(First embodiment)
Drawing 1 is a mimetic diagram showing decorative concrete 2 (concrete member) of this embodiment.
The decorative concrete 2 has a concrete colorant containing a phenolic compound (compound P1 described later) that emits a natural tone color not shown on the decorative surface 4a (surface) of the concrete member 4 constituting the building or structure. It is.
Here, the phrase “attached” to the concrete colorant is a term including “applied”, “impregnated” and “transferred”.

  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.

  Further, clear is applied to the decorative surface 4 a of the concrete member 4 to form a transparent film 5. The clear that can be used in the present embodiment is not particularly limited as long as the color of the colored layer 4b of the lower concrete member 4 is not changed or slightly changed even if the color is not impaired. Acrylic clear is preferable as clear that does not greatly change the wood-like color of the phenolic compound described below. Examples of such acrylic clear include Eco Clear (manufactured by Eco Revival Co., Ltd.). By using acrylic clear, an effect of deepening the wood-like color of the phenolic compound attached to the concrete surface can be obtained.

  Here, “clear” refers to a solution containing a component capable of forming a transparent film on the concrete surface. The “acrylic clear” means a solution containing an acrylic resin as the component. As an acrylic resin, the high molecular compound which contains (meth) acrylic acid ester or its derivative as a structural unit is said. In the present embodiment, a known acrylic resin can be applied.

  The solvent constituting the clear is not particularly limited as long as it is not strong enough to completely wash off the colored layer previously formed on the decorative surface 4a, and a known organic solvent or aqueous solvent can be used. The colored layer 4d formed after adhesion and drying of the concrete colorant, which will be described later, adheres and penetrates firmly on the decorative surface 4a, and therefore hardly peels off or falls off when the clear is applied.

  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. Moreover, it is not restricted to these, Cement paste generally used for a building or a structure, mortar, concrete, etc. are applicable without a restriction | limiting.

<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 (cured).

  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, a concrete colorant 13 described later is attached to the decorative surface 4 a 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.
Here, “attaching” a concrete colorant is a term including “applying”, “impregnating”, and “transferring”.

  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. Further, 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 terms of suppressing the color change of the decorative surface 4a of the concrete member 4 (fading with the progress of the drying material age), the concrete 12 is placed within the drying material age of 0 days, preferably within 7 days of the drying material age, More preferably, the clear is preferably applied to the decorative surface 4a of the concrete member 4 (that is, on the dried concrete colorant 13) within 3 to 5 days after application of the concrete colorant. Moreover, it is preferable that the concrete colorant 13 previously applied is dried before the clear application.

<Protection of concrete member 4>
The method of applying the clear is not particularly limited, and examples thereof include a method of applying the clear solution to the colored surface using a brush or the like. From the viewpoint of preventing the occurrence of pinholes or uneven coating on the transparent film (coating film) formed on the surface by clearing, it is preferable to apply clear (multiple coatings) repeatedly several times.
The decorative concrete 2 is completed through the above steps.

  According to the concrete protecting method of the present embodiment, the decorative surface 4a of the concrete member 4 is easily and stably colored in a wood-like color, and acid rain or carbon dioxide is formed by a transparent film formed on the colored surface. It is possible to suppress neutralization or acidification of the pH of the colored surface, and to maintain the alkalinity inherent in the concrete surface. As a result, the high color developability of the phenolic compound attached to the concrete surface can be maintained. In addition to such chemical protection, the colored surface 4d and the transparent coating 5 formed on the concrete decorative surface 4a can protect the concrete surface from physical impacts such as wind and rain. As a result, the colored surface of the concrete member 4 can be physically and chemically protected, and its aesthetics and warmth can be maintained over a long period of time.

  Further, in the concrete protecting method of the present embodiment, the mold 10 is removed from the concrete 12 before the drying material age of 7 days, and the concrete colorant 13 is applied to the decorative surface 4a of the concrete member 4, and further the decorative surface. By applying clear to 4a, the decorative surface 4a of the concrete member 4 is colored with good color development, and the fading of the concrete member 4 with the age of the drying material can be suppressed.

(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, and a phenolic compound (compound P1) described later penetrates into the colored layer 4d and the decorative surface 4a. The concavo-convex pattern of the wood pattern (wood grain) is formed on. Due to the unevenness of the wood pattern, the decorative concrete 3 further brings out the beauty and warmth characteristic of 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 14 (wood) having a concavo-convex pattern of wood 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 pattern 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 to make up the makeup having the wood pattern 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 concavo-convex pattern of the wood pattern is transferred to the surface 12 p of the concrete 12 that has been in contact with the wooden mold (bottom plate) 14 of the mold 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 mold 14 simultaneously with the uneven pattern of the wood 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.

Further, as a concrete coloring method in the present embodiment, the concrete 12 is placed on a form 14 made of wood, and components such as pigments inherently contained in the wood constituting the form (bottom plate) 14 are: By transferring the cast concrete 12 to the surface in contact with the formwork 14, the concrete surface can be colored. Therefore, immediately after demolding, the decorative surface 4a of the concrete member 4 is colored with a pigment derived from wood (a state where the pigment is attached), and the coloring process of the concrete member 4 after demolding can be omitted. Furthermore, by this method, the concavo-convex pattern of the wood pattern can be simultaneously transferred to the surface 12p of the concrete 12 in contact with the mold 14.
In this method, the pigment can be transferred from the wooden formwork to the concrete surface while waiting for the time required for solidification after placing the concrete, so that no special effort is required. The dye to be transferred usually contains a plurality of compounds and is considered to contain a phenolic compound (compound P1) described later. If the wood formwork is used repeatedly, the dye in the wood formwork will be consumed and the transfer efficiency of the dye will decrease, so it is better to avoid using the same wood formwork repeatedly in this coloring method. . The kind of wood to be used is not particularly limited, and for example, cedar, lawan, larch and the like are suitable.

<Protection of concrete member 4>
Subsequently, clear is applied to the decorative surface 4 a of the concrete member 4. The coating method can be performed in the same manner as described in the first embodiment.
The decorative concrete 3 is completed through the above steps.

In 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, thereby forming a concavo-convex pattern peculiar to wood on the decorative surface 4 a of the concrete member 4. It is possible to further enhance the aesthetics and the warmth brewed from the decorative concrete 3.
In addition, the transparent film 5 formed by clear applied to the decorative surface 4a physically and chemically protects the colored layer and the concavo-convex pattern on the decorative surface 4a, and maintains its aesthetics and warmth for a long period of time. can do.

<Concrete colorant>
The embodiment of the concrete colorant used in the present invention contains a 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 used in 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, catechins, lignins and tannins that are commonly contained in a variety of woods. By including any one or more of catechin, lignin and tannin in the concrete colorant, the concrete color has a more natural wood texture by utilizing the color of the wood of catechin, lignin and tannin attached to the concrete surface. The surface can be colored.

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.

  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, the content is preferably 0.1 to 40% by weight, more preferably 1 to 20% by weight, based on the total volume of the colorant. 10% by weight is more preferred.

 When gallic acid is contained in the concrete colorant, the concentration is not particularly limited, but is preferably 0.1 to 40% by weight, more preferably 1 to 20% by weight, based on the total volume of the colorant, 10% by weight is more preferred.

 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 weight or more of water with respect to the total volume 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 used in the present invention 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.

  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.

(Reference Example 1)
A cedar plate measuring 300 mm in length and 100 mm in width was used as a bottom plate, and a side plate matched with 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 immediately after demolding of uncolored N50 and the test body of this test example. In the test body of this test example, since the hue varies depending on the measurement location, Table 1 shows the average value of the measurement values at 12 locations on the measurement surface.

From the results shown in 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.

  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. 8 is presumed to have been 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. In this test example, the range from the measurement surface of the test 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, acid-alkaline aqueous solution extraction experiment was done with reference to the chemical substance test method of slag of JIS K0058-1 with respect to the colored sample and the non-colored sample. 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 test example, the 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 Reference Example 1, in addition to the measurement surface of the test piece 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 It is thought that aesthetics and warmth are enhanced.

(Comparative Example 1)
A wall-type concrete member A having a length of 1800 mm, a width of 1800 mm, and a thickness of 200 mm was prepared using medium-heated Portland cement.

  As a mold used for placing the wall-shaped concrete member A, a mold having a cedar plate similar to that of Reference Example 1 as a bottom plate was used. Also, a concrete colorant containing compound P1 obtained by extraction from cedar into an aqueous solvent was prepared in advance, and this colorant was applied to the bottom plate made of cedar before placing concrete. As a result, the compound P1 was transferred to the measurement surface of each mockup together with the unevenness of the cedar wood pattern (wood grain), and a beautiful texture like wood was expressed.

  Furthermore, the case where the cedar board used as the bottom plate of the formwork in the production of the wall-type concrete member A is changed to a veneer plywood, a larch plywood, and a cedar board whose surface is covered with a resin film is added to the wall-type concrete member Similarly to A, wall-type concrete members B, C, and D were produced. At this time, before placing the concrete, a concrete colorant containing a compound P1 obtained by extraction into a water-based solvent from the same type of wood used as the bottom plate was applied in advance. Thereby, the compound P1 was transferred to the measurement surface of each wall-type concrete member together with the unevenness of the wood pattern (wood grain) of each plate material, and a beautiful texture like wood was expressed.

The lightness L ^* and b ^* of the colored surface of each wall-type concrete member coated with the compound P1 derived from each plate material was measured. The results are shown in FIGS. In these figures, the measured value at the time of demolding (dry material age 3 days) and the measured value in the state of outdoor exposure until the dry material age 22 days are shown together. In FIG. 11 and FIG. 12, “cedar real”, “veneered plywood”, “larch plywood”, and “film” correspond to the wall-type concrete members A, B, C, and D, respectively.

In the wall-type concrete member D, the value of b ^* at the time of demolding is lower than that of other wall-type concrete members. As a cause of this, on the measurement surface of other wall-type concrete members, the b ^* value reflects the pigment such as the compound P1 transferred from the plate material itself constituting the bottom plate when the concrete is placed, whereas the wall It is considered that the measurement surface of the mold concrete member D is colored only by a small amount of the concrete colorant applied to the film surface.

On the measurement surface of each wall-type concrete member, the lightness L ^* increased and b ^* tended to decrease by outdoor exposure for 22 days. This tendency was observed not only for cedar boards but also for veneer plywood and larch plywood. As a factor of the decrease in b ^* , it is considered that the colorant was washed away by wind and rain or the colorant was decomposed because the measurement surface was not clear and covered and protected during outdoor exposure.

Example 1
In the same manner as the wall-type concrete member A of Comparative Example 1, two wall-type concrete members were produced using low heat Portland cement. When demolding, trade name Samtec A-1 was used as a release agent. The produced wall-type concrete member was exposed outdoors as in Comparative Example 1.
Acrylic clear (trade name: Eco Clear, manufactured by Eco Revival Co., Ltd.) was applied to the measurement surface of the first wall-type concrete member previously colored with a concrete colorant at the age of 7 days of dry material. In addition, eco-clear was applied to the colored measurement surface of the second wall-shaped concrete member when the dry material age was 28 days.

On the measurement surface of each member, the change in b ^* with the passage of dry material age was examined. The result is shown in FIG. When Ecoclear was applied at the dry material age of 7 days, b ^* increased by about 1 and then maintained a high value (plot shown by “●” in the figure). On the other hand, when Ecoclear was applied at the age of 28 days of dry material, b ^* was smaller than 5 before application, and even when Ecoclear was applied, there was almost no increase in b ^* . (Plot indicated by “◯” in the figure).

As for the first wall-type concrete member, the clear surface was applied on the 7th day of the dry material to protect the colored surface, so that the decomposition of the phenolic compound on the colored surface was prevented, and / or the colored surface. It is considered that the fading of b ^* was suppressed as a result of preventing the alkalinity inherent in the concrete from being neutralized by carbon dioxide in the atmosphere. In addition, it is considered that an increase in b ^* was observed when clear was applied due to the interaction between the clear and the phenolic compound on the colored surface.

About the 2nd wall type concrete member, although clear was apply | coated on the dry material age 28th, fading of b ^* had already advanced before the application | coating. The reason for this fading is considered to be that the phenolic compound on the colored surface was decomposed and / or the concrete on the colored surface was already neutralized by carbon dioxide in the atmosphere. It can be understood from the above results that even if clear is applied to the colored surface on which these phenomena have already occurred, no increase in b ^* is observed.

  From the above results, it can be said that it is preferable to apply clear at a time when the dry material age is relatively small, for example, within 7 days of the dry material age.

(Example 2)
Using the low heat Portland cement, like the wall-type concrete member A of Comparative Example 1, four wall-type concrete members (third to sixth wall-type concrete members) were produced. When demolding, trade name Samtec A-1 was used as a release agent. The produced third to sixth wall-type concrete members were exposed outdoors as in Comparative Example 1.

  As in Example 1, the measurement surface of the wall-shaped concrete member H previously colored with a concrete colorant is acrylic clear (product name: Eco Clear, Eco Revival Co., Ltd.) at the dry material age of 7-9 days. Applied). Similarly, at the same dry material age of 7 to 9 days, a fluorine base, a pure coat, and a nanosilicon coat were respectively applied to the colored surfaces of the third to sixth wall-type concrete members. Here, the fluorine base is a clear containing fluororesin (trade name: Pyrex, manufactured by Pyrex Technologies, Inc.), and the pure coat is a clear containing fluororesin and a photocatalyst (made by Pyrex Technologies, Inc.) The nanosilicon coat is clear (manufactured by Fukko Co., Ltd.) containing silicone.

On the measurement surface of each member, the change in b ^* with the passage of dry material age was examined. The result is shown in FIG. As for the third wall-type concrete member, by applying acrylic clear, in addition to the effect of increasing b ^* at the time of application, the effect of suppressing the decrease of b ^* over a long period was confirmed (Fig. Plot indicated by “O” in the middle) These excellent effects were also confirmed when acrylic clear other than Eco Clear was used. On the other hand, for the fourth to sixth wall-type concrete members coated with fluorine undercoat, pure coat, and nanosilicon coat, b ^* declines after about one year, and there is a tendency to noticeably lose the wood tone. (Plots indicated by “□”, “△”, “▽” in the figure).

  From the above results, it was found that particularly excellent effects can be obtained by using acrylic clear in the present invention.

(Reference 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 concrete surface layer portion in contact with the bottom surface of the formwork is divided into six sections a to f as shown in FIG. 15, and the center portion of each section (the position of the X mark in FIG. 15). ) 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.

(Reference 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 white plate was coated with a tannic acid aqueous solution containing tannic acid at a concentration of 5 to 10% by weight and dried, the coated 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.

2 ... decorative concrete, 3 ... decorative concrete, 4 ... concrete member (concrete), 4a ... decorative face, 4d ... colored layer, 5 ... transparent coating (clear) 10 ... formwork, 12 ... concrete, 12p ... concrete surface, 13 ... Concrete colorant, 14 ... Formwork having phase shape (wooden formwork)

Claims (12)

Attaching a concrete colorant containing a phenolic compound represented by the following general formula (P1) to the concrete surface;
Applying clear to the surface to which the concrete colorant is attached;
A method for protecting concrete, comprising:
[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 method for protecting concrete according to claim 1, wherein acrylic clear is used as the clear.   The method for protecting concrete according to claim 1 or 2, wherein clear is applied to the surface within 7 days of the dry material age of the concrete.   The method for protecting concrete according to any one of claims 1 to 3, wherein the phenolic compound is lignin or tannin.   The method for protecting concrete according to any one of claims 1 to 3, wherein the phenolic compound is gallic acid.   The method for protecting concrete according to any one of claims 1 to 5, wherein the phenolic compound is a compound extracted by immersing wood in an aqueous solvent.   The method for protecting concrete according to claim 6, wherein the wood is immersed in an aqueous solvent having a pH of 4 or higher.   The method for protecting concrete according to claim 6 or 7, wherein the wood is cedar, lauan, or larch. The method of protecting concrete according to any one of claims 1 to 8, characterized in that the unevenness of the wood pattern is formed on the colored surface of the concrete. A step of attaching a pigment derived from wood contained in the wood formwork to the surface of the concrete by placing concrete on the wood formwork;
Applying clear to the surface of the concrete to which the pigment is attached;
A method for protecting concrete, comprising:   The method for protecting concrete according to claim 10, wherein acrylic clear is used as the clear. The method for protecting concrete according to claim 10 or 11 , wherein clear is applied to the surface within 7 days of the dry material age of the concrete.