JP2006044986A - Molded body and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded article made of calcium hydroxide as a raw material as well as plaster, having excellent humidity control and light weight, practical strength, and good workability.
SOLUTION: It consists of 100 parts by weight of inorganic particles (A), 5-50 parts by weight of hydrophilic polymer compound (B), 2-50 parts by weight of fiber reinforcement (C) and 50-150 parts by weight of water (D). A composition in which 10 to 100% by weight of the inorganic particles (A) is calcium hydroxide (A1) is kneaded, shaped, and dried to give a bulk specific gravity of 1.25 or less and a bending strength of 2N. / Mm ² or more of a molded body is obtained.
[Selection figure] None

Description

  The present invention relates to a molded article comprising inorganic particles, a hydrophilic polymer compound and a fiber reinforcing material, and more particularly to a molded article containing calcium hydroxide as inorganic particles and a method for producing the same.

  As so-called sick house syndrome becomes a social problem, various building materials such as plywood, particle board, vinyl cloth, adhesive, and paint are regarded as problems. Under such circumstances, plaster, which is no longer used in modern buildings, is being reviewed. Plaster is mainly composed of slaked lime (calcium hydroxide), but it does not dissipate volatile organic compounds that cause sick house syndrome, and it has excellent humidity control and has the effect of preventing indoor condensation. is doing. At the time of disposal, there is no worry of releasing harmful substances, and it has soil improvement properties for acidic soil.

  However, plaster is usually used as a painted wall because of its low strength and weakness to impact. Therefore, on-site construction is required, and in order not to cause cracks or peeling on the wall, it is necessary to perform an overcoat operation by a skilled plasterer. In the present age, the number of excellent plasterers has decreased, and due to the problem that the construction period is prolonged, the current situation is that the demands of those who wish to plaster cannot be met.

  In JP-A-10-212152 (Patent Document 1) and JP-A-2000-238021 (Patent Document 2), powdery calcium hydroxide and powdered inorganic aggregate (for example, calcium carbonate) are pressurized. A method for producing a molded article formed by molding is known. Thus, it is said that a molded product suitable for building materials can be obtained without firing and autoclaving, which is excellent in strength and water absorption, easy to cut. This publication also describes that porous inorganic particles such as diatomaceous earth, natural fibers, and the like may be added. However, in the method described in the publication, pressure molding is performed in a vacuum, or pressure molding is performed at a high pressure exceeding 100 MPa. Therefore, the density of the molded body is increased, and humidity control and workability are not necessarily achieved. It was not enough. In addition, a large-scale manufacturing apparatus is required, and it is difficult to obtain a large-area product as in the case of a normal fired tile.

On the other hand, Japanese Patent Laid-Open No. 6-271344 (Patent Document 3) has a bulk density of 0 obtained by molding a molding material composed of cement, diatomaceous earth, quartz sand, slaked lime, reinforcing fibers, and resin emulsion, and then curing by autoclave. A composite of 4-1.0 g / cm ³ is described. As a result, it is said that a composite material having a light weight, high strength and good workability can be obtained. However, since what is mainly contained as a hardening | curing agent is cement, when discarding the obtained composite material, it was not necessarily easy. Moreover, the humidity control property was not sufficient, and an autoclave was required for production.

Japanese Patent Laid-Open No. 10-212152 JP 2000-238021 A JP-A-6-271344

  The present invention has been made in order to solve the above-mentioned problems, using calcium hydroxide as a raw material in the same manner as plaster, having excellent humidity control and light weight, practical strength, and workability. The object is to provide a good molded article. Moreover, the suitable manufacturing method of such a molded object is provided.

  The above-mentioned problem consists of 100 parts by weight of inorganic particles (A), 5 to 50 parts by weight of hydrophilic polymer compound (B) and 2 to 50 parts by weight of fiber reinforcing material (C), and 10 to 10 parts of inorganic particles (A). This is solved by providing a shaped body in which 100% by weight is calcium hydroxide (A1).

  At this time, it is preferable that the inorganic particles (A) comprise 10 to 95% by weight of calcium hydroxide (A1) and 5 to 90% by weight of the porous inorganic particles (A2) or the hollow particles (A3). It is also preferred that the hydrophilic polymer compound (B) is at least one selected from the group consisting of polyvinyl alcohol, protein, cellulose derivative, starch derivative, pullulan and derivatives thereof, and plant gum.

The molded article of the present invention preferably has a bulk specific gravity of 1.25 or less. It is also preferable that the bending strength measured based on JIS A1408 is 2 N / mm ² or more. Furthermore, the moisture absorption amount per unit area when the molded body that was allowed to stand in an atmosphere of 20 ° C. and 50% RH for 7 days is left to stand in an atmosphere of 20 ° C. and 90% RH for 24 hours is 50 g / m ² or more. It is also suitable. A preferred embodiment of the molded article of the present invention is a building material.

  Moreover, the said subject is from inorganic particle (A) 100 weight part, hydrophilic polymer compound (B) 5-50 weight part, fiber reinforcement (C) 2-50 weight part, and water (D) 50-150 weight part. By providing a method for producing a molded product, characterized in that a composition in which 10 to 100% by weight of the inorganic particles (A) is calcium hydroxide (A1) is kneaded and then shaped and dried. Is also resolved. At this time, it is preferable that the composition after kneading and before shaping is in the form of clay.

  The molded product of the present invention contains calcium hydroxide in the same manner as the plaster that has been used since ancient times, and maintains the inherent advantages of plaster in terms of humidity control and environmental compatibility. In addition, it is a molded article having excellent lightness, practical strength, and good workability. The molded body can be easily produced, and is particularly useful as a building material.

  The raw material of the molded body of the present invention is inorganic particles (A) 100 parts by weight, hydrophilic polymer compound (B) 5 to 50 parts by weight and fiber reinforcing material (C) 2 to 50 parts by weight. 10 to 100% by weight of calcium hydroxide (A1). These are kneaded with 50 to 150 parts by weight of water (D), shaped, and dried. The plaster obtained by drying a mixture of calcium hydroxide (A1) and water (D) has low strength and is mostly used in a method of applying to a substrate. By blending the molecular compound (B) and the fiber reinforcing material (C), the strength can be greatly improved.

  The inorganic particles (A) are all or partly made of calcium hydroxide (A1), so that humidity control similar to plaster is exhibited. Specifically, it is necessary that 10 to 100% by weight of the inorganic particles (A) is calcium hydroxide (A1). It is also preferable that the total amount of inorganic particles is calcium hydroxide (A1), and a molded product having a property closer to plaster can be obtained. On the other hand, when the content of calcium hydroxide (A1) is less than 10% by weight among the inorganic particles (A), sufficient strength cannot be obtained. Among the inorganic particles (A), the content of calcium hydroxide (A1) is preferably 15% by weight or more, and more preferably 20% by weight or more.

  As calcium hydroxide (A1), the powder is usually used. When quick lime (calcium oxide) is used as a raw material, when kneaded with water (D), it is digested by water (D) to become slaked lime, so it was not used for digestion with calcium hydroxide (A1) after all. This is the same as mixing with water (D).

  The inorganic particles (A) other than calcium hydroxide (A1) are not particularly limited, and calcium carbonate, calcium sulfate, calcium phosphate, aluminum sulfate, magnesium hydroxide, aluminum hydroxide, alumina, silica sand, titanium oxide, talc Mica, montmorillonite, bentonite, clay, kaolin, cement and the like can be used. However, when there are too many inorganic particles (A) other than calcium hydroxide (A1), effects such as humidity control may be reduced, so the blending amount is appropriately adjusted.

  When the inorganic particles (A) other than calcium hydroxide (A1) are porous inorganic particles (A2) or hollow particles (A3), the molded article obtained has a reduced bulk specific gravity, and has excellent lightweight properties. Goods can be obtained. In particular, by using the porous inorganic particles (A2), it is possible to obtain a molded article having excellent humidity control and chemical substance adsorption. Among the inorganic particles (A) in this case, the content of the porous inorganic particles (A2) or the hollow particles (A3) is preferably 5 to 90% by weight. When weight is more important, the content of the porous inorganic particles (A2) or the hollow particles (A3) is more preferably 20% by weight or more (in this case, calcium hydroxide (A1) is 80% by weight or less. More preferably, it is 50% by weight or more (in this case, calcium hydroxide (A1) is 50% by weight or less).

  Examples of the porous inorganic particles (A2) include diatomaceous earth, zeolite, activated carbon, silica gel, vermiculite, pumice sand, and coal ash. Among these, diatomaceous earth is preferably used when emphasizing humidity control performance. Moreover, when importance is attached to the adsorptivity of chemical substances, zeolite and activated carbon are preferably used. Examples of the hollow particles (A3) include shirasu balloons, glass balloons, silica balloons, fly ash balloons, perlite, and the like.

  The hydrophilic polymer compound (B) used as a raw material has a polar functional group and absorbs water (D) to swell, or dissolves in water (D) to become a highly viscous solution. Anything is possible. Specifically, polyvinyl alcohol; proteins such as gluten and casein; cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose; hydroxyalkyl starch, cationic starch, starch acetate, phosphoric acid Examples include starch derivatives such as starch; pullulan derivatives such as pullulan and acetylated pullulan; and plant gums such as gum arabic, guar gum, locust bean gum, tragacanth gum, xanthan gum, and gellan gum. In view of the durability and production cost of the composition, polyvinyl alcohol is preferably used. As the polyvinyl alcohol, a modified product can be used, and polyvinyl alcohol having various performances such as anionic property, cationic property, and crosslinking property can be used. The modification may be performed at the end of the molecular chain or in the molecular chain. In consideration of the environmental load at the time of disposal, natural polymer compounds or derivatives thereof are preferably used. As shown in the examples below, when the total amount of the inorganic particles (A) is diatomaceous earth and gluten, hemp pulverized material and water (D) are blended, practical strength cannot be obtained. It is considered that the strength of the molded product is improved by the combination of calcium oxide (A1) and the hydrophilic polymer compound (B).

  Content of a hydrophilic high molecular compound (B) is 5-50 weight part with respect to 100 weight part of inorganic particles (A). By containing a certain amount or more of the hydrophilic polymer compound (B), a lightweight and high-strength molded product can be obtained. The content of the hydrophilic polymer compound (B) is preferably 10 parts by weight or more. Further, it is preferably 30 parts by weight or less.

  As the fiber reinforcement (C), either organic fiber or inorganic fiber can be used. Examples of organic fibers include natural fibers such as hemp, cotton, wool, and wood fibers; recycled fibers such as rayon and acetate; and synthetic fibers such as vinylon, polyolefin, polyamide, polyester, and acrylic. Examples of the inorganic fiber include glass fiber and carbon fiber. These fiber reinforcements (C) are selected according to the purpose. Considering the decomposability at the time of disposal, the use of natural fibers or recycled fibers is preferable, and the use of synthetic fibers or inorganic fibers is preferable in consideration of long-term strength maintenance. In view of fire resistance, it is preferable to use inorganic fibers. Since the composition containing calcium hydroxide (A1) exhibits alkalinity, in consideration of the stability therein, cellulose fibers such as hemp, cotton, wood fiber, and rayon are preferred as natural fibers and regenerated fibers, As synthetic fibers, vinylon and polyolefin are preferable, and inorganic fibers are also preferable. The form of the fiber is not particularly limited, but short fibers are usually used.

  The content of the fiber reinforcing material (C) is 2 to 50 parts by weight with respect to 100 parts by weight of the inorganic particles (A). By containing an appropriate amount of fiber reinforcing agent, it is possible to effectively suppress the occurrence of cracks resulting from shrinkage during drying, and to exert a reinforcing effect. When the content of the fiber reinforcing material (C) is less than 2 parts by weight, cracks occur at the time of curing, and a molded article having practical strength cannot be obtained. The amount is preferably 5 parts by weight or more. On the other hand, when the content of the fiber reinforcing material (C) exceeds 50 parts by weight, the strength and durability are lowered, and the fire resistance is also lowered when organic fibers are used. It may become. The amount is preferably 30 parts by weight or less, and more preferably 15 parts by weight or less.

  The amount of water (D) blended in the inorganic particles (A), the hydrophilic polymer compound (B) and the fiber reinforcing material (C) is 50 to 150 parts by weight with respect to 100 parts by weight of the inorganic particles (A). is there. If the amount of water (D) is too large, shrinkage during drying becomes large and cracks are likely to occur, and extra energy is required for drying. On the other hand, when the amount of water (D) is too small, moisture unevenness is likely to occur in the composition, and the strength of the molded body is reduced. When the porous inorganic particles (A2) are used as a part of the inorganic particles (A), or when the amount of the fiber reinforcing material (C) is large, it is preferable that the amount of water is large, and 80 wt. Part or more. On the other hand, when the inorganic particles (A) are substantially composed only of calcium hydroxide (A1) or when the amount of the fiber reinforcing material (C) is small, the amount of water is preferably small. It is preferable that it is below the weight part.

  You may mix | blend components other than the said inorganic particle (A), a hydrophilic polymer compound (B), a fiber reinforcement (C), and water (D) in the range which does not inhibit the effect of this invention. For example, a colorant, an antibacterial agent, an antifungal agent, a shrinkage reducing agent, a surfactant and the like can be blended as necessary.

  The method for kneading the raw materials is not particularly limited, and all of the above raw materials may be mixed at once, or the remaining raw materials may be mixed after mixing some of the raw materials. Among these, the method of mixing water (D) after sufficiently mixing the inorganic particles (A), the hydrophilic polymer compound (B) and the fiber reinforcing material (C) in advance is a uniform composition. It is easy to obtain and preferable. In kneading, by sufficiently kneading, the hydrophilic polymer compound (B) can sufficiently absorb moisture and can adhere to the inorganic particles (A), particularly calcium hydroxide (A1), As a result, a molded article having excellent strength can be obtained. It is preferable to adjust the amount of water (D) so that these raw materials are mixed and kneaded and the composition before shaping is in the form of clay. Here, the clay shape means a state in which plastic deformation is possible but does not flow in a short time (for example, about 1 minute). By kneading by such a method, a lightweight and high-strength molded body can be obtained. The kneading apparatus is not particularly limited, and various mixers, rolls, extruders, and the like can be used. If it is a small amount, it can be kneaded manually.

  The composition is kneaded and then molded. The forming method is not particularly limited, and it may be filled in a desired mold or may be continuously formed between rolls. When molding a building board, it is preferable to obtain a plate-like body having a uniform thickness through the rolls.

  After shaping, it is subjected to drying. The drying conditions are not particularly limited, and drying may be performed by heating, or drying may be performed for a long time without particularly heating. If productivity is considered, it is more preferable to heat-dry and the drying temperature in this case is about 40-100 degreeC normally. The drying time is about 1 to 100 hours.

  The molded product thus obtained was composed of 100 parts by weight of inorganic particles (A), 5 to 50 parts by weight of hydrophilic polymer compound (B) and 2 to 50 parts by weight of fiber reinforcing material (C), and inorganic particles (A ) Is a molded body in which 10 to 100% by weight is calcium hydroxide (A1). During drying, some calcium hydroxide (A1) may react with carbon dioxide in the air and turn into calcium carbonate, but it is usually part of the surface and most of it is calcium hydroxide (A1). It remains. Although it gradually changes to calcium carbonate over a long period of use, this is the same phenomenon as stucco, and this is rather expected to improve strength.

  It is preferable that the bulk specific gravity of the molded body is 1.25 or less. The weight can be reduced as compared with the case where the normal specific gravity of the plaster exceeds 1.5. The bulk specific gravity is more preferably 1.15 or less. Depending on the formulation, the weight can be further reduced, and the bulk specific gravity can be 1 or less. In particular, when some of the inorganic particles (A) are porous inorganic particles (A2) or hollow particles (A3), the weight can be easily reduced. The normal bulk specific gravity is 0.5 or more. The fact that the bulk specific gravity is small also means that there are fine voids inside the molded body, which means that heat insulation and sound insulation are excellent. Here, the bulk specific gravity is the bulk specific gravity in a state where most of the water has been released. Specifically, the bulk specific gravity is set in an oven at 80 ° C. to determine the weight when the weight becomes constant. It is a value obtained by dividing by volume.

It is also preferable that the bending strength of the molded body is 2 N / mm ² or more. By having such bending strength, practical strength can be obtained when used as a building material. The bending strength is more preferably 3 N / mm ² or more, and further preferably 4 N / mm ² or more. The higher the proportion of calcium hydroxide (A1) in the inorganic particles (A), the easier it is to increase the strength. In this case, 50 to 100% by weight of the inorganic particles (A) is preferably calcium hydroxide (A1), more preferably 80 to 100% by weight is calcium hydroxide (A1), It is optimal to consist essentially of calcium hydroxide (A1). Here, the bending strength of the molded product is a value measured using a strip-shaped test body based on JIS A1408. The test piece has a length of (15t + 50) mm and a width of 50 mm, where the thickness is tmm. In the bending test, the head speed was set to 10 mm / min and the span length was set to 15 tmm by a three-point bending test method.

Moreover, the moisture absorption amount per unit area when the molded body left to stand in an atmosphere of 20 ° C. and 50% RH for 7 days is left to stand in an atmosphere of 20 ° C. and 90% RH for 24 hours is 50 g / m ² or more. Is preferred. By having such a moisture absorption amount, when used as an interior material, it is possible to provide an excellent humidity control function for preventing indoor condensation and drying. The amount of moisture absorption is more preferably 100 g / m ² or more. Moreover, it is usually 500 g / m ² or less.

The use of the molded body thus obtained is not particularly limited, but is suitably used as a building material. Since it does not dissipate volatile chemical substances that cause so-called sick house syndrome and is excellent in humidity control, it is particularly suitably used as an interior material for buildings. Since the conventional plaster is insufficient in strength, it is difficult to use in the form of a board, and application work on site is necessary, but the molded body of the present invention is excellent in strength, so it is provided as a building board. Is easy. It is also excellent in workability, and can be cut with a saw or nail, for example, and has excellent workability. It is lightweight and has excellent heat insulation and sound insulation. Furthermore, since it has an inorganic compound as a main component, it is excellent in flame retardancy and has a wide range of application as a building material. Manufacturing is also easy, for example, a board with a large area can be easily manufactured. In the case of a board, the preferred thickness is about ² to 30 mm, and the area is about 0.5 to 10 m ² .

  The molded article of the present invention usually does not contain substances that pollute the environment. For example, in the case of a gypsum board mainly composed of calcium sulfate, hydrogen sulfide may be generated by the action of degrading bacteria after disposal, but such a problem does not occur. In addition, it does not harden like a cement-based composition and can be easily crushed, making it easy to dispose of it even after it has been used for a long time as a building material. It is. At that time, since the main components are calcium hydroxide (A1) and calcium carbonate generated during long-term use, it can be crushed after use and used as an acidic soil conditioner. In this way, it can be said that the product is suitable for the environment even in consideration of the product life cycle.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, the performance evaluation method of the molded product was performed according to the following method.

(1) Bulk Specific Gravity The bulk specific gravity was determined by measuring the weight of the compact immediately after drying, measuring the dimensions of the compact to determine the volume, and dividing the weight by the volume.

(2) Moisture content The weight of a molded body immediately after drying formed using a wooden frame having a length of 230 mm, a width of 50 mm, and a thickness of 12 mm was measured, and left in a constant temperature and humidity room at 20 ° C. and 65% RH for 7 days. The weight of the molded body was measured, and the moisture content (% by weight) was determined from these weights.

(3) Bending strength It measured based on JIS A1408 using the molded object after measuring a moisture content. A three-point bending test was performed, and the span length was 180 mm and the head speed was 10 mm / min. The measurement was performed in a constant temperature and humidity room at 20 ° C. and 65% RH.

(4) Moisture absorption A molded body formed using a wooden frame having a length of 190 mm, a width of 130 mm, and a thickness of 5 mm was left in a thermostatic chamber at 20 ° C. and 50% RH for 7 days, and its weight Then, the weight after standing in a constant temperature and humidity chamber at 20 ° C. and 90% RH for 24 hours is measured, and the difference in weight is divided by the surface area to obtain the amount of moisture absorption per unit area (g / M ² ).

The raw materials used in the examples are as follows.
(A) Inorganic particles (A1) Calcium hydroxide Slaked lime: Special grade reagent manufactured by Wako Pure Chemical Industries, Ltd. (A2) Porous inorganic particles Diatomaceous earth: “Radiolite # 200” manufactured by Showa Chemical Industry Co., Ltd.
(B) Hydrophilic polymer compound Wheat gluten: Reagent manufactured by Wako Pure Chemical Industries, Ltd. Milk-derived casein: Reagent manufactured by Wako Pure Chemical Industries, Ltd. Polyvinyl alcohol: Reagent "Polyvinyl alcohol # 2000" manufactured by Kanto Chemical Co., Ltd.
(C) Fiber Reinforcement Material Lamy (Hemp Ground): Tosco Co., Ltd. 2mm Cut Product (D) Water Distilled Water (Comparative Example Raw Material)
Commercial plaster: Toyo Materan Co., Ltd.

Example 1
100 parts by weight of slaked lime, 20 parts by weight of polyvinyl alcohol and 10 parts by weight of ramie were mixed and stirred well by hand. When the whole was well mixed, knead by hand while adding water. When 84 parts by weight of water was added, the water spread evenly throughout and became a clay, so it was kneaded by hand. The obtained clay-like composition was filled in a wooden frame having a length of 230 mm, a width of 50 mm, a thickness of 12 mm and a wooden frame of 190 mm in length, 130 mm in width, and 5 mm in thickness, and the surface was smoothed with a rolling pin. The shaped composition was removed from the wooden frame and placed in an oven and dried at 80 ° C. for 18 hours. About the obtained molded object, bulk specific gravity, moisture content, bending strength, and moisture absorption were evaluated according to the above-mentioned method. The evaluation results are summarized in Table 1. Further, the obtained molded body could be cut with a saw and nailing was possible.

Examples 2 to 15 and Comparative Examples 1 to 6

  A molded body was obtained in the same manner as in Example 1 except that the blending ratio of the raw materials was changed as shown in Table 1. After kneading, the composition before shaping was in the form of clay with moisture uniformly distributed over the whole, as in Example 1. The evaluation results are summarized in Table 1.

As is apparent from Table 1, Comparative Example 5 containing no calcium hydroxide (A1), Comparative Examples 3 and 4 containing no hydrophilic polymer compound (B), and Comparative Example 1 containing no fiber reinforcing material (C) And 6, all of Comparative Example 2 containing neither the hydrophilic polymer compound (B) nor the fiber reinforcing material (C) had a bending strength of less than ² N / mm ² and was insufficient in strength. On the other hand, the molded bodies of Examples 1 to 15 containing all of calcium hydroxide (A1), hydrophilic polymer compound (B) and fiber reinforcing material (C) are excellent in strength. It was found that the strength can be improved by combining the components.

  Comparative Examples 2 and 3 using commercially available plaster have a large bulk specific gravity, and it was found that weight reduction can be achieved while improving the strength by blending the hydrophilic polymer compound (B). When the blending ratio of the porous inorganic particles (A2) (diatomaceous earth) and the blending ratio of the fiber reinforcing material (C) (ramie) increased, a tendency to improve the lightness was recognized. Moreover, it turned out that the molded object of this invention is excellent in all the intensity | strength, lightness, and humidity control property compared with the comparative example 2 which hardened the commercially available plaster.

Claims (9)

It consists of 100 parts by weight of inorganic particles (A), 5-50 parts by weight of hydrophilic polymer compound (B) and 2-50 parts by weight of fiber reinforcement (C), and 10-100% by weight of inorganic particles (A). The molded object which is calcium hydroxide (A1). The molded body according to claim 1, wherein the inorganic particles (A) comprise 10 to 95% by weight of calcium hydroxide (A1) and 5 to 90% by weight of porous inorganic particles (A2) or hollow particles (A3). The molded article according to claim 1 or 2, wherein the hydrophilic polymer compound (B) is at least one selected from the group consisting of polyvinyl alcohol, protein, cellulose derivative, starch derivative, pullulan and derivatives thereof, and plant gum. The molded body according to any one of claims 1 to 3, wherein the bulk specific gravity is 1.25 or less. The molded article according to any one of claims 1 to 4, wherein the bending strength measured based on JIS A1408 is 2 N / mm ² or more. A moisture absorption amount per unit area when a molded body left to stand in an atmosphere of 20 ° C and 50% RH for 7 days is left to stand in an atmosphere of 20 ° C and 90% RH for 24 hours is 50 g / m ² or more. The molded object in any one of 1-5. The building material which consists of a molded object in any one of Claims 1-6. It consists of 100 parts by weight of inorganic particles (A), 5 to 50 parts by weight of hydrophilic polymer compound (B), 2 to 50 parts by weight of fiber reinforcement (C) and 50 to 150 parts by weight of water (D). A method for producing a molded article, characterized in that a composition in which 10 to 100% by weight of A) is calcium hydroxide (A1) is kneaded and then shaped and dried. The method for producing a molded article according to claim 8, wherein the composition after kneading and before shaping is clay-like.