JP2013189327A - Method for producing inorganic cured body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an inorganic cured body having excellent mold releasability, high strength and excellent surface appearance.SOLUTION: Vinylon fibers and polypropylene fibers are blended to a raw material including cement as reinforcing fibers 2 so that the blending amount of the vinylon fibers is 0.5-1.5 mass%, the blending amount of the polypropylene fibers is larger than the blending amount of the vinylon fibers, and the blending amount of the whole reinforcing fibers 2 is ≤5 mass%, with respect to the whole amount of a solid portion of a cement-based material 1 to be prepared. The cement-based material 1 including the reinforcing fibers is press-molded by hot press, to thereby produce an inorganic cured body.

Description

  The present invention relates to a method for producing an inorganic cured body used as an architectural panel or the like.

  Conventionally, it is known to manufacture a building panel or the like by pressing and molding a cement-based material. By press working, the surface can be formed on a smooth surface, or an uneven pattern can be imparted to the surface (for example, Patent Document 1).

JP 2009-073113 A JP-A-9-123137

  In press molding, it is important that the molding material does not adhere to the press mold (form frame) after pressing and is released well. If the molding material adheres to the press mold, the molded material may be chipped or the like, leading to product defects. In addition, if the material adheres to the press mold, the next molding material may be pressed with the material adhered, resulting in a defective product, or the work to remove the adhered material from the press mold may be required. And productivity will fall.

  It is known that a release agent such as release oil is applied to the press die so that the molding material does not adhere to the press die. The use of a release agent increases the releasability and suppresses press defects. However, the surface texture (appearance, smoothness, etc.) of the molded body sometimes deteriorated even when press molding and mold release were performed on a cementitious material using a mold form coated with a release agent. . In particular, when the reinforcing material is blended in the molding material to increase the strength of the molded body, and the molding is performed using a press mold that transfers a flat pattern, the unevenness derived from the reinforcing fiber is prominent. In some cases, the appearance of the surface of the molded body may be deteriorated.

  Patent Document 2 discloses that a cement-based material is hot-pressed and cured at the same time as molding, but it is difficult to say that the surface texture can be sufficiently improved.

  This invention is made | formed in view of said situation, and it aims at providing the manufacturing method of an inorganic hardened | cured material which is excellent in mold release property, is high intensity | strength, and has the favorable external appearance of the surface.

  In the method for producing an inorganic cured body according to the present invention, a vinylon fiber and a polypropylene fiber are used as reinforcing fibers in a raw material containing cement, and the blending amount of the vinylon fiber is based on the total solid content of the cementitious material to be prepared. The reinforcing fiber is blended so that the blending amount of the polypropylene fiber is 0.5 to 1.5% by mass, the blending amount of the polypropylene fiber is not less than the blending amount of the vinylon fiber, and the blending amount of the entire reinforcing fiber is 5% by mass or less. It is characterized by press-molding a cementitious material containing a hot press.

  According to the present invention, by hot press molding a material containing vinylon fiber and polypropylene fiber as a reinforcing fiber in the above amount, it can be manufactured with good releasability, high strength, and surface appearance. A good inorganic cured body can be obtained with high production efficiency.

The schematic diagram of an example of press molding is shown, (a) And (b) is sectional drawing.

  The inorganic hardened body is manufactured by blending vinylon fibers and polypropylene fibers as reinforcing fibers in a raw material containing cement, and press-molding the cement-based material containing the reinforcing fibers by hot pressing.

  The cement-based material is prepared by adding an appropriate additive component to cement as a main component and dispersing the mixture in water. As the raw material cement, ordinary cement can be used. For example, Portland cement, fly ash cement, blast furnace cement, alumina cement, high alumina cement, silica fume cement and the like can be used. However, the cement raw material may contain additives in advance.

  Vinylon fibers and polypropylene fibers are added to the cementitious material as reinforcing fibers. By adding the reinforcing fiber, the strength of the inorganic cured body can be increased. Moreover, a strong inorganic hardened body can be obtained by using a vinylon fiber as a reinforcing fiber. That is, when a bending force is applied to the plate-like inorganic cured body by blending vinylon fibers, a slight force works to absorb the force and suppress plate bending, and increase the strength against bending force. It is something that can be done. Further, by using polypropylene fiber as the reinforcing fiber, an inorganic cured body having high impact resistance can be obtained. That is, when a force that gives an impact to the plate-like inorganic cured body is applied by blending polypropylene fibers, the destruction of the plate can be suppressed and the strength against the impact force can be increased. Thus, by using a vinylon fiber and a polypropylene fiber together as a reinforcing fiber, a strong strength that cannot be obtained alone can be obtained. As the reinforcing fiber, a fiber having a fiber length of 0.5 to 10 mm, more preferably 2 to 8 mm, and a fiber diameter of 1 to 100 μm, and more preferably 10 to 30 μm can be used. is not.

  The compounding amount of the reinforcing fiber is 0.5 to 1.5% by mass of the vinylon fiber based on the total solid content of the cement-based material to be prepared, and the compounding amount of the polypropylene fiber is equal to or more than the compounding amount of the vinylon fiber. And it is set as the compounding quantity from which the compounding quantity of the whole reinforcing fiber becomes 5 mass% or less. When the blending amount of the vinylon fiber is 0.5 to 1.5% by mass, a strong and strong inorganic cured body can be obtained. If the amount of vinylon fiber is too small, the strength may not be increased, and if the amount of vinylon fiber is too large, the surface smoothness may be impaired. In order to increase the strength, the blending amount of the vinylon fiber is preferably 1% by mass or more, and more preferably 1.2% by mass or more. Moreover, in order to improve surface smoothness, it is preferable that the compounding quantity of a vinylon fiber is 1.4 mass% or less, and it is further more preferable that it is 1.3 mass% or less.

  Moreover, the inorganic hardened | cured material excellent in impact resistance can be obtained because the compounding quantity of a polypropylene fiber is more than the compounding quantity of a vinylon fiber. The blending amount of the polypropylene fiber is preferably larger than the blending amount of the vinylon fiber. For example, the blending amount of polypropylene fiber may be 1.2 times or more of the blending amount of vinylon fiber. The upper limit of the amount of polypropylene fiber may be 3% by mass or 2% by mass.

  Moreover, the intensity | strength of an inorganic hardening body can be improved, ensuring sufficiently the moldability of cementitious material by making the compounding quantity of the whole reinforcing fiber into 5 mass% or less. In order to improve the dispersibility of the reinforcing fiber in the cement-based material, the amount of the reinforcing fiber is preferably 4% by mass or less, and more preferably 3% by mass or less. In addition, the minimum of the compounding quantity of the whole reinforcement fiber is 1 mass% from which the compounding quantity of a vinylon fiber and a polypropylene fiber becomes 0.5 mass% each.

  Aggregate is preferably added to the cement-based material, and light-weight aggregate is more preferably added. By adding a lightweight aggregate, it is possible to reduce the weight, and it is possible to obtain an inorganic cured body with good dimensional stability and high weather resistance. As the lightweight aggregate, perlite, fired vermiculite, fly ash balloon, synthetic resin beads, synthetic resin foam and the like can be used. The blending amount of the lightweight aggregate can be 0.1 to 1.5% by mass with respect to the total solid content of the cementitious material.

  Moreover, it is preferable to add a water reducing agent to the cementitious material. By adding a water reducing agent, a material with high cement dispersibility can be obtained. The water reducing agent may be a surfactant usually used for cement-based materials. As the water reducing agent, an AE water reducing agent or the like can be used. The water reducing agent may be in a standard form, a delayed form, or an accelerated form. The blending amount of the water reducing agent can be 0.5 to 3% by mass with respect to the total solid content of the cementitious material.

  Moreover, you may add a thickener to a cement-type material. By adding a thickener, it is possible to obtain a material that is easy to mold by adjusting the viscosity. The thickener may be a thickener commonly used for cementitious materials. For example, a cellulose thickener can be used. In addition, a water-soluble thickener can be used. Although the compounding quantity of a thickener can be 0.5-3 mass% with respect to the solid content whole quantity of a cementitious material, it is not limited to this. Moreover, you may make it the total amount of a water reducing agent and a thickener become 0.5-3 mass% with respect to solid content whole quantity of a cementitious material.

  Usually, water is blended in the cement-based material. By blending water, the cementitious material becomes a fluid cement slurry, and the material can be dispersed more uniformly, and can be molded into an appropriate shape by extrusion molding or the like.

  The compounding quantity of water can be 10-100 mass% from a viewpoint of a dispersibility and a moldability. This amount of water is an amount relative to the solid content of the cementitious material. That is, components other than water can be generally considered as the solid content, and may be blended when the total amount is 100% by mass. The blending amount of water is more preferably 20 to 50% by mass.

  Other appropriate additives may be added to the cementitious material. Examples of the additive component include a colorant, a pigment, a viscosity modifier, and the like. A reverse emulsified emulsion may be prepared by blending a polymer and an emulsifier with a cement-based material.

  Then, a cement slurry in which the above materials are dispersed and mixed is prepared, the cement slurry is poured into an extrusion molding machine, and molded with an extrusion mold, for example, to be molded into a plate shape. However, in this state, the molding material is not completely cured and is in a so-called green sheet state. The green sheet may be obtained using a papermaking machine. The obtained green sheet is sent to a press machine by conveyance with a conveyor or the like, and is press-molded.

  In this embodiment, the press molding is performed by hot pressing. Cement-based materials can be molded with good releasability by hot pressing. In other words, when pressed at room temperature, the material may adhere to the press die and remain behind, but by applying heat to the material, the adhesion of the material is reduced and the material after molding can be easily released. Can be made. Further, in the hot press, the material can be easily released without using a release agent, so that the production efficiency can be improved. Of course, a release agent may be used in order to obtain further release properties. When a release agent is used, it may be applied to a press die or sprayed on the surface of the molding material.

  In addition, by press molding by hot pressing, it is possible to reduce the unevenness of the surface of the molded body derived from the fibers and smooth the surface, so that the appearance (texture) of the surface of the molded body can be improved. . Therefore, it is possible to produce an inorganic cured body having a particularly flat surface with good appearance.

  As a cause of unevenness on the surface of the cement molded body, when organic fibers (vinylon fiber and polypropylene fiber) are added to the cement-based material as reinforcing fibers, the fibers are closely intertwined in the mixing process, and fiber balls (dama) Is formed. When the fiber ball is formed, a lump of fibers derived from the fiber ball appears as surface irregularities on the surface of the molded body.

  The mechanism for improving the smoothness of the surface of the molded body is presumed as follows. Before the cement-based material is press-molded, hydrophilic vinylon fibers and water-containing polypropylene fibers are present as fiber balls on the surface of the material. Then, by pressing the press die (die) in a heated state, heat and pressure are applied to the surface portion of the material in contact with the press die. Thereby, the fiber ball changes its shape by hot pressing (heat and pressure), and the fiber ball fiber is loosened. At this time, the cement matrix material and water are present around the reinforcing fiber, but in hot press molding, the cement matrix material is heated more than the press at room temperature (for example, 20 ° C.), and the material temperature is increased. And the fluidity of the material is improved. Therefore, the fiber ball is more easily loosened by hot pressing. Thus, it is presumed that the irregularities on the surface of the molded body are reduced because the fiber ball is loosened. Moreover, in the present invention, strong vinylon fibers and weak polypropylene fibers are used in combination. Even with vinylon fibers alone, even if they are once adapted to the cement matrix by hot pressing, they return to a shape close to the original fiber shape when returning to room temperature, and the smoothness of the surface of the molded body is likely to be lost. However, due to the combined use of fibers, polypropylene fibers are present around the vinylon fibers in the present invention. Therefore, the loss of the smoothness of the surface of the molded product is suppressed by absorbing the restoring force of the vinylon fiber which tries to return to the shape close to the original fiber shape when returning to normal temperature to some extent by the weakly weak polypropylene fiber around it. It is guessed. That is, it is assumed that the fiber ball is loosened by the same ironing effect as the ironing of clothes, and the surface of the molded body becomes smooth.

  FIG. 1 is an example of press molding, and shows a schematic view of a state where fiber balls on the material surface portion are loosened by press molding. As shown in FIG. 1A, the cement-based material 1 before pressing has fiber balls in which reinforcing fibers 2 are intertwined closely. In this state, a part of the fiber ball formed by the reinforcing fibers 2a near the surface protrudes from the surface of the cementitious material 1, and irregularities derived from the reinforcing fibers 2a are formed on the surface. Then, as shown in FIG. 1 (b), when hot pressing is performed on the cement-based material 1, the surface of the cement-based material 1 is heated and pressed by the press die 3, and thereby the reinforcing fibers 2a in which the fiber is loosened. Is obtained. When the fiber ball is loosened (or loosening is reduced), the reinforcing fiber 2a constituting the fiber ball existing on the surface of the molding material is deformed in fiber shape, and the protrusion on the cementitious material surface disappears. In this way, a molded body having a smooth surface can be obtained. Note that the above-described mechanism for improving the surface smoothness is an example of a presumed mechanism, and it goes without saying that the present invention is not limited to this.

  The heating temperature of the hot press is preferably 80 to 100 ° C. If it is less than 80 degreeC, there exists a possibility that the effect of a surface smoothness improvement may not fully be exhibited. Moreover, when it exceeds 100 degreeC, since press temperature exceeds the boiling point of water, the surface water | moisture content will evaporate and there exists a possibility that the property of a molded object may deteriorate. The pressing force of the hot press is not particularly limited, but can be set, for example, in the range of 1 to 10 MPa from the viewpoint of moldability. The press holding time may be in the range of 3 to 30 seconds.

  As the press mold, an appropriate one such as one having a smooth surface or one having a concavo-convex pattern transferred can be used. In this embodiment, even when a surface having a smooth surface is pressed, the appearance of the surface of the molded body can be improved, and an inorganic cured body having a flat surface can be easily obtained. In addition, when forming an inorganic cured body with a concavo-convex pattern, it is possible to suppress the formation of concavo-convex that impairs the appearance design derived from fibers different from the concavo-convex constituting the design, and the concavo-convex pattern is good An inorganic cured body can be obtained.

  The press-molded molded body is cured as an inorganic hardened body used for building materials. Of course, the inorganic cured body may be subjected to various types of coating and processing (cutting, bonding, etc.). The inorganic cured body thus obtained has high strength and excellent surface appearance, and can be used, for example, as a building panel such as an outer wall material or a roof material.

  Cement-based materials were prepared with the compounding amounts shown in Table 1, and press-molded with a press mold having a flat surface.

The specifications of the materials used are as follows.
・ Cement: Portland cement.
Vinylon fiber: average fiber length 4-6 mm, average fiber diameter 10-20 μm.
Polypropylene fiber: Average fiber length 4-6 mm, average fiber diameter 20-30 μm.
-Lightweight aggregate: Resin foam microcapsule Particle size 40-60 μm
-Water reducing agent: polycarboxylic acid-based dispersant.
-Thickener: Methylcellulose.

  The cement-based material was prepared by blending each material and mixing and kneading with an Eirich mixer. Each material was press-molded to obtain a rectangular plate-shaped molded body (size: long side 600 mm, short side 250 mm, thickness 10 mm). In the case of a normal press (press temperature: 20 ° C.), a release oil (petroleum hydrocarbon) was applied to the press die as a release agent and pressed. In the case of hot pressing, no release agent was used. The press holding time was 5 to 10 seconds. The press molding pressure was 1 to 10 MPa. Moreover, the temperature of the material before a press was 10-30 degreeC. The obtained molded body was cured for 7 days, and an inorganic cured body was produced as a test body.

  About the test body, the surface smoothness test | inspection, the bending strength test, and the impact resistance test were done. The surface smoothness is determined by visual inspection of the naked eye, “◯: the surface is smooth and there are no irregularities”, “△: the surface is almost smooth, but some irregularities are seen”, “×: irregularities are observed. Evaluation was made on the basis of “a large number of formed and non-smooth surfaces”. The bending strength was measured according to JIS A 1408. The impact strength was measured according to the Charpy impact test JIS K7111-1 and the Charpy impact strength was measured.

  The results are shown in Table 1.

  In Examples 1 to 7, the strength of the test body was increased by blending the reinforcing fibers, and the smoothness of the test body after pressing was improved by hot pressing (80 to 100 ° C.). In addition, as shown in Examples 5, 6, and 7, it was confirmed that the smoothness decreased as the amount of vinylon was increased.

  In Comparative Examples 1 and 2, only the polypropylene fiber was blended as the reinforcing fiber, and it was confirmed that the strength was insufficient. In Comparative Examples 3 to 5, the strength was improved by adding vinylon fibers (0.5 to 1.5% by mass). Usually, press (20 ° C., using release oil) was performed. Therefore, the smoothness of the specimen surface was not good.

  Moreover, sufficient performance was not obtained also in the comparative examples 6-9 which performed the hot press. In Comparative Example 6 in which no vinylon fiber was blended, the bending strength was small and the impact resistance was low. In Comparative Example 7 in which no polypropylene fiber was blended and in Comparative Example 8 in which the blending amount of polypropylene fiber was lower than that of vinylon fiber, the impact resistance was low. In Comparative Example 9 having a large amount of vinylon fiber, the surface smoothness was poor. In Comparative Example 10 in which the total amount of reinforcing fibers exceeded 5% by mass, the kneaded material was hard and a large number of fiber balls were generated and could not be molded.

1 Cement-based material 2 Reinforcing fiber 3 Press die

Claims (1)

  A vinylon fiber and a polypropylene fiber are used as a reinforcing fiber in a raw material containing cement, and the blending amount of the vinylon fiber is 0.5 to 1.5% by mass with respect to the total solid content of the cement-based material to be prepared. The fiber is blended so that the blending amount is not less than the blending amount of the vinylon fiber and the blending amount of the entire reinforcing fiber is 5 mass% or less, and the cement-based material containing the reinforcing fiber is press-molded by hot pressing. The manufacturing method of the inorganic hardened | cured material characterized by doing.

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