JP2007008740A - Building material having adsorption function and photocatalytic function and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a building material having an adsorption function and a photocatalytic function and a method of manufacturing the same. <P>SOLUTION: The building material having a photocatalyst is obtained by carrying out a reaction in site by a hydrothermal synthesis to harden a raw material formed body in a ceramic based building material and the formation of the photocatalyst from a photocatalyst precursor applied on the surface of the raw material formed body at the same time to directly synthesize the photocatalyst on the surface or the surface layer part of the hardened body of the raw material formed body. The method of manufacturing the building material is carried out by applying the photocatalyst precursor on the surface of the raw material formed body and performing hydrothermal reaction to harden the raw material formed body to form a calcium silicate hardened body and at the same time, to synthesize the photocatalyst on the surface or the surface layer part. As a result, the building material having the photocatalyst firmly stuck on the base material surface of calcium silicate is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a manufacturing method of the building material and building material in which a photocatalyst is directly synthesized with respect to the surface and surface layer portion of the ceramic building material having an adsorption function, and more specifically, the present invention relates to a ceramic industry. In the building material, the surface of the raw material molded body is cured by simultaneously curing the raw material molded body by in-situ reaction by hydrothermal synthesis and photocatalytic conversion of the photocatalyst precursor applied to the surface of the raw material molded body. In addition, the present invention relates to a building material having a photocatalyst obtained by directly synthesizing a photocatalyst layer on a surface layer portion and a method for producing the same. INDUSTRIAL APPLICABILITY The present invention can be used as a building material having excellent incombustibility, can be used as an interior material, a ceiling material, a partition wall, and the like, can provide a comfortable living environment space, and can be used as a building material suitable for a fireproof structure. It provides new building materials that can be used.

  In recent years, the airtightness of building structures has progressed, and it has become necessary to adsorb pollutants in the air such as volatile organic substances such as acetaldehyde and formaldehyde, ammonia with a strong off-flavor, etc., which are the cause of sick house syndrome. As the adsorbent, a porous body having many fine pores is used. As this porous body, for example, apatite, zeolite, activated carbon, silica gel, diatomaceous earth, anhydrous silica, calcium silicate and the like are known.

  As a moisture absorbing / releasing building material blended with zeolite, a prior art document proposes a humidity control building material comprising a zeolite and a setting and hardening material (see Patent Document 1). In addition, other prior art documents have antibacterial and antifungal properties mainly made from zeolite powders or granules obtained by supporting metal ions on zeolite that has been subjected to high temperature activation treatment so as to have a humidity control action. A humidity-controllable building material has been proposed (see Patent Document 2).

  The humidity-controllable building material described above can adsorb pollutants in the air, but in addition, a building material having a function of decomposing the adsorbed material with a photocatalyst has been proposed. As a building material that uses an adsorbent and a photocatalyst, a prior art document proposes a building material in which a film containing a hygroscopic agent and a photocatalyst is formed on the surface of a base material (see Patent Document 3). In other prior art documents, a concrete structure having a surface layer portion as a photocatalyst containing layer has been proposed (see Patent Document 4).

  However, in the building materials having the above-described adsorption and photocatalytic functions, there arises a problem that the photocatalyst cannot be satisfactorily adhered to the surface of the calcium silicate substrate. In addition, due to this adhesion problem, the actual situation is that the photocatalytic function cannot be effectively imparted to the cured calcium silicate.

Japanese Patent Laid-Open No. 3-93662 JP-A-3-109244 JP-A-7-113272 JP 2001-317199 A

  Under such circumstances, the present inventors have aimed to develop a new building material capable of causing the photocatalyst to adhere well to the surface of the calcium silicate substrate in view of the above-described conventional technology. As a result of intensive research, the synthesis of the hardened calcium silicate and the photocatalyst precursor photocatalyst are simultaneously performed by in-situ reaction, and the photocatalyst is directly synthesized on the surface or surface layer of the cured product of the raw material. Thus, the inventors have found that the intended purpose can be achieved, and have completed the present invention.

  The object of the present invention is to provide calcium silicate, which is widely known as a ceramic building material, as a main component of the base material, and by adding an adsorbent to provide an adsorption function, and the surface of a cured body made of calcium silicate Another object of the present invention is to provide a building material in which a photocatalyst typified by titanium oxide is directly synthesized on the surface layer portion and the photocatalyst is firmly adhered, and a manufacturing method thereof.

The present invention for solving the above-described problems comprises the following technical means.
(1) In ceramic building materials, raw material molding is performed by simultaneously curing the raw material molded body and photocatalyst of the photocatalyst precursor applied to the surface of the raw material molded body by in situ reaction by hydrothermal synthesis. A building material having a photocatalyst, wherein the photocatalyst is directly synthesized on the surface or surface layer of a cured body of the body.
(2) The material according to (1), wherein the raw material molded body contains one or more raw materials selected from siliceous materials, calcareous materials, cement, slag, and gypsum as main raw materials.
(3) The material according to (1) above, which contains an adsorbent and / or a fiber reinforcing material as an auxiliary material.
(4) The material according to (1), wherein the raw material molded body is cured to obtain a calcium silicate cured body.
(5) In the method for producing ceramic building materials, after applying the photocatalyst precursor to the surface of the raw material molded body, by performing a hydrothermal reaction, the raw material molded body is cured and the calcium silicate cured body and And a method for producing a building material, wherein a photocatalyst is synthesized on the surface or surface layer of the cured body.
(6) One or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum are used as main raw materials, and adsorbent, fiber reinforcing material and water are added and mixed into a predetermined shape. The manufacturing method of the building material as described in said (5) which uses it as a raw material molded object.

Next, the present invention will be described in more detail.
The present invention relates to a ceramic building material by simultaneously performing curing of a raw material molded body and photocatalysis of a photocatalyst precursor applied to the surface of the raw material molded body by an in situ reaction by hydrothermal synthesis. It is characterized in that it is a building material having a photocatalyst characterized by directly synthesizing a photocatalyst on the surface or surface layer part of a cured product of the molded body, and in its production method.

  Here, the ceramic building material means a building material made of a cured calcium silicate cured by curing, and has excellent durability with no fear of corrosion or insect damage. Widely used as interior materials, ceiling materials, partition walls, building exterior materials, etc. This ceramic building material was obtained by molding one or more raw materials selected from cement, siliceous material, calcareous material, slag and gypsum as main raw materials, and adding and mixing fiber reinforcing materials and water. The raw material molded body is manufactured by curing by hydrothermal curing, steam curing, and normal temperature and normal pressure curing. This ceramic building material is characterized by being porous and exhibiting strength despite its low specific gravity and excellent workability and easy transportability. In this ceramic building material, an adsorbent can be mixed to improve the adsorption function.

  In the present invention, preferably, for example, one or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum are used as main raw materials, and a mixture containing an adsorbent, a fiber reinforcing material, and water is predetermined. After having applied the photocatalyst precursor to the surface of the obtained raw material molded body as a raw material molded body, the raw material molded body is cured and cured to have an adsorption function. It becomes possible to obtain a building material having an adsorption function and a photocatalytic function by effectively synthesizing the photocatalyst with respect to the surface or the surface layer portion of the cured body as well as the calcium silicate cured body.

  Further, according to the production method of the present invention, by the in-situ reaction by hydrothermal synthesis, the hardening of the calcium silicate of the raw material molded body and the photocatalyst conversion of the photocatalyst precursor applied to the surface of the raw material molded body is performed, for example, 1 Since the photocatalyst can be directly synthesized on the surface or surface layer part of the cured body of the raw material molded body by performing the hydrothermal reaction at the same time, it is possible to manufacture a building material in which the photocatalyst is firmly adhered at low cost. Can be provided.

  Thus, the building material of the present invention has an adsorbing function on the base material itself, and the photocatalyst is firmly adhered to the surface or surface layer portion of the cured body of the raw material molded body, so that, for example, sick house syndrome Type that can absorb and decompose volatile organic chemicals such as acetaldehyde and formaldehyde, air pollutants such as ammonia with strong off-flavor, bacteria, viruses, etc. It can be suitably used as a building material.

  The manufacturing method of the building material of the present invention comprises one or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum as main raw materials, and adsorbent, fiber reinforcing material and water are added and mixed. Then, it is molded into an arbitrary shape such as a plate, a block, a roof tile, a structure member, etc. to form a raw material molded body, and after applying the photocatalyst precursor gel to the surface of the obtained raw material molded body, By performing a thermal reaction, simultaneously curing the raw material molded body and photocatalyzing the photocatalyst precursor in situ reaction, that is, curing the raw material molded body to form a calcium silicate cured body, The photocatalyst is directly synthesized on the surface or surface layer of the cured product of the raw material molded body.

Here, the siliceous material refers to a raw material containing silicic acid (SiO ₂ ), for example, fine mineral powder such as silica stone, silica sand, diatomaceous earth, white clay, pearlite, dust such as fly ash, silica fume, etc. Alternatively, materials equivalent or similar to these can be used. As the calcareous material, for example, quick lime, slaked lime, slaked lime milk obtained by digesting quick lime with water or warm water, or a material equivalent or similar to these can be adopted.

  As the fiber reinforcing material, for example, organic and / or inorganic fiber reinforcing materials can be employed. As the organic fiber reinforcing material, for example, cellulose fiber, polypropylene fiber, aramid fiber or the like can be employed. As the inorganic fiber reinforcing material, for example, glass fiber, stainless fiber or the like can be employed. As the adsorbent, for example, zeolite, sepiolite, apatite, activated carbon, silica gel, anhydrous silica and the like are suitable, and one kind may be used alone, or two or more kinds may be used in combination. Thereby, a high adsorption function can be imparted. In the present invention, the above-mentioned materials are not limited to those described above, and are equivalent or similar to them, and can be used in the same manner as long as they have the same effect.

  When colored makeup is applied to building materials, painting is often used. Conventionally, the formation of a photocatalyst layer on a base material coated with paint has a problem in that the organic paint is mixed with the paint, so that the cosmetic paint is destroyed when the photocatalyst is brought into direct contact with the coating film. Therefore, after forming an inorganic film on the coating film, it is necessary to form a photocatalyst layer, and the process is complicated for forming a multilayer structure. Furthermore, with a base material having an adsorption function, forming a film on the surface blocks the fine pores of the base material, resulting in a problem that the adsorption function of the base material cannot be exhibited.

  On the other hand, in the present invention, the substrate is made of porous particles or particles having a large specific surface area, such as apatite, zeolite, sepiolite, activated carbon, Bincho charcoal, pulverized coal, silica gel, anhydrous silica, etc. Has an adsorption function, and by applying the photocatalyst precursor to the substrate surface without blocking the porosity of the substrate surface, for example, by the above-described manufacturing process, for example, adsorption and decomposition of odors and bacteria It becomes possible to produce ceramic building materials that can be processed repeatedly.

  For the problem of coloring makeup on the building materials, in the present invention, for example, in the raw material mixing step, an inorganic pigment is mixed uniformly to obtain a molded body, whereby a building having a colored photocatalytic function is obtained. It is also possible to obtain material. Here, examples of the inorganic pigment include materials mainly composed of oxides, hydroxides or sulfides of various metals such as titanium, iron, chromium, cobalt, and the like. These inorganic pigments may be used alone or in combination of two or more. In selecting a raw material, for example, an optional component such as a polymer binder, a piece of wood, or glass beads may be appropriately added as long as the effects of the present invention are not hindered.

  In the manufacturing process of an inorganic building material having an adsorption function and a photocatalytic function according to the present invention, one or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum are used as main raw materials, and adsorbents and fiber reinforcements are used. A material and water are added, and if necessary, an inorganic pigment is added to make a kneaded material having fluidity such as a gel, and a raw material molded body is formed by molding.

  The raw material molded body made of the above constituent materials can be obtained as follows. That is, an appropriate amount of water is added after the constituent materials are mixed at a predetermined ratio. As a molding method, for example, a known molding method such as papermaking, dewatering press molding, or extrusion molding can be used.

  When papermaking or dehydration press molding is used as the molding method, a large amount of water is mixed with the constituent material to form a slurry, and then the constituent material may be molded under arbitrary conditions. In addition, when performing papermaking molding or dehydration press molding, a flocculant or other components may be added at the time of molding, and in this way, by adding a flocculant or other components at the time of molding, The moldability can be improved.

  In addition, when extrusion molding is used as a molding method, a small amount of water and a cellulose-based extrusion aid are mixed, and mixed and stirred to form a clay-like kneaded product. Therefore, the specific gravity of each raw material in the kneaded product is Less affected by non-uniformity due to differences. Moreover, according to the present invention, a plate material having a flat surface, a plate material having a relatively shallow surface pattern, a three-dimensional structure member, and the like can be effectively continuously produced. That is, in the present invention, it is possible to form a building material rich in design such as a flat plate, a surrounding edge, a parting edge, and a building member such as a window frame.

Moreover, the manufacturing method of the building material according to the present invention includes a photocatalyst precursor gel applied to the raw material molded body, and then curing the raw material molded body by in situ reaction by hydrothermal synthesis. The photocatalyst precursor applied on the surface is simultaneously photocatalyzed to synthesize the photocatalyst directly on the surface or surface layer of the cured product of the raw material molded body. Here, examples of the photocatalyst precursor used include TiO ₂ , titanium oxide, nitrogen-doped titanium oxide, derivatives thereof, oxides such as WO ₃ , ZnO, Fe ₂ O ₃ , SrTiO _{2, and the} like. Examples thereof include a raw material slurry prepared by using a starting material of a material having a photocatalytic function which has a response property of ultraviolet light or visible light which is a similar material, and an amorphous gel in which the reaction is performed to the middle. In this invention, if it is a photocatalyst precursor which can be photocatalyzed by the in-situ reaction by hydrothermal synthesis, it can be used without being restrict | limited to the kind.

The concentration of the photocatalyst precursor is not particularly limited, but is generally 0.4 to 9.5% by weight, and the coating amount of the photocatalyst precursor with respect to the raw material molded body is the above-mentioned precursor. In the case of the concentration, it may be about 50 to 200 g / m ² . The photocatalyst precursor may be applied by a spray method, a curtain coater method, a roll coater method, painting with a brush, or the like. In this coating, it is not necessary to cover the surface of the base material in the form of a film, and it is important not to block the porosity of the base material surface.

  The hydrothermal reaction performed after apply | coating a photocatalyst precursor with respect to a raw material molded object can be implemented using an autoclave. In addition, the hydrothermal reaction conditions can be appropriately determined depending on the type of siliceous material or calcareous material constituting the raw material molded body, for example, under a saturated water vapor pressure of 105 to 180 ° C. The hydrothermal reaction may be performed for about 1 to 18 hours.

By setting the conditions of the hydrothermal reaction in such a range, the photocatalyst can be directly directly synthesized on the surface or surface layer portion of the raw material molded body, and at the same time, the calcium silicate synthesized in the raw material molded body is synthesized. A calcium acid hardened body will be formed. It is preferable to subject the cured body subjected to the hydrothermal reaction to a drying treatment if necessary. Here, the conditions for the drying treatment may be appropriately determined depending on the water content of the cured calcium silicate.
In the conventional materials, various building materials coated with a photocatalyst have been developed. However, it has been difficult to produce a building material that exhibits good photocatalyst adhesion, high photocatalytic function, and the like at low cost. On the other hand, in the present invention, the raw material molded body is cured and the photocatalyst precursor applied to the surface of the raw material molded body is simultaneously photocatalyzed by in-situ reaction by hydrothermal synthesis. By directly synthesizing the photocatalyst on the surface or surface layer of the cured body of the raw material molded body, building materials having good photocatalyst adhesion, durability, high photocatalytic function, etc. can be produced at a low cost by simple means. And can be provided.

According to the present invention, the following effects can be obtained.
(1) Since the photocatalyst and calcium silicate can be synthesized simultaneously by one hydrothermal reaction, a building material in which the photocatalyst is firmly adhered can be produced at low cost.
(2) Since the substrate has an adsorption function and a photocatalytic function, it can be treated by repeating adsorption and decomposition.
(3) For this reason, volatile organic substances such as acetaldehyde and formaldehyde, which cause the sick house syndrome, ammonia with a strong off-flavor, and pollutants in the air such as various bacteria and viruses can be suitably adsorbed.
(4) Therefore, it can be advantageously used as an environmental purification type building material such as a hospital, a protection facility for elderly people, a toilet, a ceiling material for a smoking room, a wall material, and the like.
(5) Moreover, since calcium silicate which is a constituent material is a non-combustible material, it becomes a building material excellent in non-combustibility as well as adsorption characteristics.

  Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples.

  By using the blending ratio shown in Table 1 for the raw materials shown below, a raw material molded body of a ceramic building material having an excellent adsorption function was obtained by the following manufacturing method.

(Raw materials used)
Cement: Ordinary Portland cement fiber Reinforcement material: Fiber made of softwood bleached kraft pulp (NBKP) and polypropylene fiber (1: 1 blending ratio)
Silica powder: SiO ₂ content 97.8% by weight
Pearlite: Pearlite JIS S0.15-0.6
Zeolite: Ca-type artificial zeolite inorganic pigment: Yellow iron oxide methylcellulose: Thickener

  According to the formulation shown in Table 1, each raw material and water were mixed to obtain a mixed material, and then kneaded for 10 minutes using a commercially available mortar mixer with a stirring rate of 50 rpm. The obtained kneaded product was extruded by an extrusion molding machine to obtain a plate-shaped raw material molded body having a length of 450 mm, a width of 300 mm, and a thickness of 8 mm.

AT-03 (manufactured by Photocatalyst Laboratory Co., Ltd.) was used as a photocatalyst precursor on the surface of the obtained raw material molded body, and an amount of 130 g / m ² was surface-coated by spraying. After coating, hydrothermal treatment reaction was performed for 10 hours under a pressure of 0.49 MPa (value obtained by converting actual data 5 kgf / cm ² into SI units), followed by drying at 120 ° C. for 12 hours, and the building material of the present invention Got.

  In order to confirm the performance as a building material for the plate material obtained in the above example, according to the following evaluation conditions, "bulk specific gravity", "bending strength", "water absorption rate" and "water absorption length change rate" Measured and compared. In addition, “appearance” and “cutability” were also confirmed and compared and evaluated. The results are shown in Table 2.

Below, evaluation methods and determination methods for bulk specific gravity, bending strength, water absorption, water absorption length change rate, appearance and cutting workability are shown.
The bulk specific gravity was measured according to JIS A5430 (n = 3). The bending strength was measured according to JIS A1408 (n = 3). The water absorption was measured according to JIS A5430 (n = 3). The rate of change in water absorption length was measured in accordance with JIS A5430 (n = 3).

  Next, the appearance of the obtained plate material was visually observed and confirmed. Then, the case where there was no abnormality in the appearance was determined as “◯”, the case where the appearance was normal, “Δ”, and the case where the appearance was warped was determined as “X”. For the cutting workability, the obtained plate material was cut with a tip saw (outer diameter 355 mm), and the linearity of the cut surface was visually observed and confirmed. Then, the case where the cut surface was good was determined as “◯”, the case where it was normal, “Δ”, and the case where the cut surface was bent was determined as “X”.

  As can be seen from the results in Table 2, the plate materials obtained in the examples are well cured despite the simultaneous synthesis of calcium silicate and photocatalyst and exhibit excellent bending strength. I understand. Further, the rate of change in water absorption length was low, and the product had sufficient dimensional stability against water absorption. And the external appearance and cutting workability were also favorable. From the above, it was confirmed that there was no problem even if this plate material was used as a building material. Moreover, since this board | plate material contains the inorganic pigment, it is a building material which does not require the coating process as coloring.

  As described above in detail, the present invention relates to a building material having an adsorption function and a photocatalytic function and a method for producing the same, and according to the present invention, synthesis of a photocatalyst and synthesis of calcium silicate are performed in a ceramic building material. By carrying out simultaneously, the building material to which the photocatalyst was firmly stuck can be manufactured simply and at low cost. The present invention makes it possible to provide a new high-functional building material having an adsorption function and having a photocatalyst firmly adhered thereto.

Claims (6)

  In ceramic building materials, the raw material molded body is cured by simultaneous reaction of the raw material molded body and photocatalyst precursor applied to the surface of the raw material molded body by in situ reaction by hydrothermal synthesis. A building material having a photocatalyst, wherein the photocatalyst is directly synthesized on the surface or surface of the body.   The material according to claim 1, wherein the raw material molded body contains, as a main raw material, one or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum.   The material according to claim 1, comprising an adsorbent and / or a fiber reinforcing material as an auxiliary material.   The material according to claim 1, wherein the raw material molded body is cured to obtain a calcium silicate cured body.   In the method for producing ceramic building materials, after applying the photocatalyst precursor to the surface of the raw material molded body, by performing a hydrothermal reaction, the raw material molded body is cured to form a calcium silicate cured body, A method for producing a building material, comprising synthesizing a photocatalyst on the surface or surface layer of the cured body.   One or more raw materials selected from siliceous materials, calcareous materials, cement, slag and gypsum are used as main raw materials, adsorbents, fiber reinforcing materials and water are added, mixed, and formed into a predetermined shape to form raw materials The manufacturing method of the building material of Claim 5 made into a body.