JPH0747503B2 - Calcium silicate compact - Google Patents

Description

The present invention relates to a calcium silicate compact.

Calcium silicate compacts are industrially applied to various fields such as refractory materials, fireproof heat insulating materials, adsorbents, building materials, and the like, which have the high non-strength characteristic of calcium silicate compacts, High fire resistance, heat insulation,
It is an inorganic material that is expected to develop in various fields due to its light weight and high dielectric constant. It is considered that the main point of the characteristic property is the structure of the formed body composed of calcium silicate crystals.

The inventors of the present invention have been researching calcium silicate from the above viewpoints, and when the calcium silicate crystals have a very unique secondary agglomeration structure in this research, they are light and strong. It was found that a large molded body was provided, and an invention based on this finding was completed (Patent No. 818975).

The calcium silicate secondary agglomerated particles according to this patent are substantially spherical secondary particles formed by three-dimensionally entangled calcium silicate crystals, and have an outer diameter of 10 to 1
The thickness was 50 μm, and the surface thereof had a structure in which a large number of whiskers based on the crystals of calcium silicate were protruding, and the calcium silicate compact obtained from this had a low density and high strength. Furthermore, the present inventors have completed various improved new inventions based on this patent,
One of them is the invention of Japanese Patent Publication No. 56-40109. The present invention relates to a tobermorite crystal compact.

As a result of further research on the relationship between the structure of calcium silicate secondary particles and the calcium silicate compact, the present inventors have succeeded in developing spherical secondary particles having a unique structure composed of tobermorite crystals. At the same time, they have found that a tobermorite molded product produced by compressing and deforming the spherical secondary particles from the crystal slurry of the spherical secondary particles has extremely excellent physical properties, and thus completed the present invention.

That is, the present invention comprises substantially spherical secondary particles formed by three-dimensionally intertwining tobermorite crystals or a small amount of other calcium silicate crystals, and an additive added as necessary. A molded body formed by compressing and deforming the secondary particles and interconnecting the secondary particles, wherein (1) the density of the original molded body containing no additive is substantially 0.3 g / cm ³ or more. Alternatively, the density of the original molded body corresponding to the molded body to which the additive is added is substantially 0.3 g / cm
When it is ³ or more, the individual spherical secondary particles constituting the molded product are flattened by compression deformation to the extent that their existence cannot be confirmed when the polished surface of the molded product is observed with a scanning electron microscope (600 times). And the original compact or the corresponding original compact has a preferential degree of orientation (P) represented by the formula P ≧ 20x−3 (where x is the density of the original compact). (2) When the density of the original molded product containing no additive is substantially less than 0.3 g / cm ³ , or the density of the original molded product corresponding to the additive added additive is substantially 0.3 g. / Cm
When it is less than ^3, the individual spherical secondary particles constituting the compact are compressed to such an extent that the presence of the spherical secondary particles can be confirmed when the polished surface of the compact is observed under a scanning electron microscope (600 times). (3) In any of the above (1) and (2), the spherical secondary particles have an outer diameter of 10 to 120 μm and a hollow ratio of 30% or less before molding. The present invention relates to a calcium silicate compact characterized by having a density of the spontaneous sedimentation compact of 0.12 g / cm ³ or less.

In the present specification, the term "spherical" includes not only a spherical shape but also an elliptical spherical shape, and these spherical and elliptical spherical shapes also have an uneven surface on at least a part thereof. Include.

As used herein, the term "original compact" means a compact obtained by compressing and deforming spherical secondary particles from a crystal slurry of spherical secondary particles without adding an additive. Refers to the "original molded product corresponding to the molded product to which the additive is added" or simply "corresponding original molded product" is the same as the crystal slurry from which the additive is added but the additive is removed. An original molded product obtained by molding the crystal slurry of (1) under the same molding conditions as when the additive is added.

According to the studies by the present inventors, the inside of the tobermorite spherical secondary particles constituting the above-mentioned molded body of the present invention is rough or hollow before molding, and the spontaneous sedimentation molded body is formed. It has been revealed that the density is relatively low and the weight is considerably light, and that the molded article produced from this is superior to the conventional molded article of Japanese Patent Publication No. 56-40109 in the following points. (A) A lightweight molded product having a density of about 0.1 g / cm ³ and having a practical bending strength of 3 kg / cm ² or more. (B) The degree of preferential orientation is substantially 0.3 g of the density of the original molding.
/ Cm ³ or more, which is particularly large.

The present invention has been completed based on the above new facts.

The molded article of the present invention is composed of spherical secondary particles consisting of tobermorite crystals alone or a mixture thereof with a small amount of other calcium silicate crystals such as zonotolite crystals in a mutually compressed and deformed state. It is a thing.

The above-mentioned specific spherical secondary particles constituting the molded article of the present invention have a secondary agglomeration having an outer diameter of 10 to 120 .mu.m before molding and an inner portion having a hollow ratio of coarse to 30% or less. It has a structure.

This is clear from, for example, the result of microscopic observation of the secondary particles before molding, which is shown in Example 1 of the present invention. That is, from the optical micrograph (FIG. 1, magnification 100 times), the secondary particles are spherical bodies and have an outer diameter of about 10 to 10.
It can be seen that the average particle size is 120 μm and the average particle size is 38 μm. A surface active agent was added to and mixed with the slurry in which the secondary particles were dispersed in water, and the mixture was allowed to stand for 48 hours for spontaneous sedimentation and then dried at 100 ° C. for 48 hours. This is fixed with Canadian balsam, then this is polished and then the above Canadian balsam is removed with xylene to obtain a polished sample. Observation of this sample with a scanning electron microscope reveals that the tobermorite crystals are coarsely aggregated to form spherical secondary particles, as shown in FIG.

When the secondary particles are dispersed and observed with an electron microscope, the length is 0.1 to 10 .mu.m as is apparent from FIG.
m, a plate crystal with a width of 0.1 to 2 μm and a length of 0.1 to 10 μ
m needles having a width of 0.05 to 0.5 μm are observed. <Measurement Method of Outer Diameter of Secondary Particles> The unidirectional diameter was measured from an optical micrograph of a spherical secondary particle mainly composed of a 100-fold tobermorite crystal taken by reflected light, and the particle diameter range and average were measured. The particle size (median size) was determined.

The spherical secondary particles of the present invention are characterized in that the breaking load of each particle is 100 mg or less.

The above-mentioned breaking load refers to a load when a crack is generated in at least a part of the spherical shell of the secondary particles of the calcium silicate crystal when the load is applied to the spherical secondary particles of the calcium silicate crystal. 10 to 100 mg means that when a load is applied to the secondary particles, the secondary particles have a spherical shell of the secondary particles when a constant load of 10 to 100 mg is applied. It means that at least a part will be cracked, and the breaking load is 1000m.
The term "g" means that at least a part of the spherical shell of the secondary particles is cracked when a load of 1000 mg is applied. <Method of measuring breaking load> The three secondary particles are placed on a slide glass in the shape of an equilateral triangle, a cover glass is placed on the slide glass, and the load is applied on the cover glass to observe with a 600 × optical microscope. It is measured by observing whether or not a crack occurs in a part of the spherical shell of the secondary particle, and is expressed by a load when the crack occurs.

Other major characteristics of the spherical secondary particles are: (a) The inside is coarse or hollow, and the hollow ratio is 30%.
The following means that the hollow ratio is measured by the following method.

A part of the spontaneous sedimentation molded body was cut out, fixed with Canadian balsam (manufactured by Yoneyama Chemical Industry Co., Ltd.), and then polished, and then the Canadian balsam was removed with xylene to obtain a polished sample. This sample was photographed with a scanning electron microscope, the radius (r) and the radius (r ') of the hollow portion were measured from the cross section of the spherical secondary particles, and the hollow ratio was obtained from the following formula.

[0018]

[Chemical 1] The hollow ratio of 30% or less indicates that the hollow part is not particularly large even if the inside of the spherical secondary particles is hollow. Moreover, the case where small hollow portions are present everywhere and the so-called inside is rough is also included.

The inside of the spherical secondary particles shown in FIG. 3 is coarse and the hollow ratio is 0%, and the hollow secondary particles shown in FIG. 4 is 0 to 25%.

For example, the hollow secondary particles made of wollastonite group calcium silicate crystals described in the examples of JP-A-53-146997 have a hollowness of 60% or more, which is basically the same as the spherical secondary particles of the present invention. Have different structures. (B) It has a characteristic that the density of the spontaneous sedimentation molding is 0.12 g / cm ³ or less, preferably 0.10 g / cm ³ or less.
The density of the spontaneous sedimentation molded product was measured by the following method.

Slurry 20 in a 300 cc tall beaker
0 cc and 0.4 cc of nonionic and anionic surfactants (Granup NF-50, Sanyo Kasei Co., concentration 20%) were added and mixed, and then left to stand for 48 hours to spontaneously settle and then dried at 100 ° C. for 48 hours. And spontaneously sink. A molded body was obtained.
The volume and weight of this were measured to determine the density.

The fact that the density of this natural sedimentation molded product is low means that the spherical secondary particles themselves are considerably lightweight, and from this secondary particle, a molded product having a density of about 0.1 g / cm ³ and practical strength is obtained. It shows that it can be manufactured.

For example, the spherical secondary particles of the tobermorite crystals described in Japanese Patent Publication No. 56-40109 have a high spontaneous sedimentation compact density, and therefore the density of 0.1 g from the known secondary particles of the tobermorite crystals. It is not possible to manufacture a molded body of about / cm ³ .

Further, the preferred spherical secondary particles of the present invention have an average apparent density of 0.14 to 0.21 g / cm ³ before molding.
Above all, it is mainly in the range of 0.16 to 0.20 g / cm ³ .
That is, the secondary particles are themselves lightweight.

The average apparent density is measured by the following method. <Measurement Method of Average Apparent Density> Tobermorite crystal slurry is replaced with water in the slurry with acetone and dried at 90 ° C. for 24 hours to form spherical secondary particles into powder without damage. This powder Wg
Is measured and placed in a beaker. Next, use a buret to impregnate the spherical secondary particles with water, and read the amount of water just when the spherical secondary particles were impregnated with water (when the viscosity of the spherical secondary particles suddenly increased) as Vml. To do. From this measurement, the average apparent density (ρ) of the spherical secondary particles was calculated by the following formula.

[0026]

[Chemical 2] However, ρt is the true specific gravity of Tobermorite, which is 2.576.
Is.

The molded product of the present invention is constituted by connecting such spherical secondary particles to each other in a shape compressed by the pressure during molding. In the molded article of the present invention, the shape of the spherical secondary particles becomes flat in the compression direction as the pressure at the time of molding increases, in other words, as the density of the molded article increases. That is, in the case where the density of the original molded body to which the additive is not added is substantially less than 0.3 g / cm ³ , a part of the molded body of the present invention is cut out, fixed with Canadian balsam, and then after polishing xylene. When the polished surface obtained by removing the Canadian balsam is observed with a scanning electron microscope, the spherical secondary particles are compressed and deformed in the compression direction due to the pressure at the time of molding, but their existence can be confirmed. For example, in FIG. 5 (magnification: 600 times) showing a scanning electron micrograph of a polished surface of a molded body having a density of 0.201 g / cm ³ shown in Example 2 of the present invention, spherical secondary particles are compressed and deformed and are connected to each other. However, the presence of spherical secondary particles can be clearly confirmed.

The density of the original molded body is substantially 0.3 g / cm.
The existence of spherical secondary particles cannot be clearly confirmed by an electron microscope as the density exceeds ³ , and the flattening becomes more severe as the density increases. This fact indicates that the tobermorite crystals are preferentially oriented,
In particular, when the density of the original compact becomes substantially 0.3 g / cm ³ or more, the preferential orientation of the crystal becomes particularly large, and the second
Table No. 2 to 4, Table 5 No. 2-3, Table 8 No. Two
~ 4, Table 11 No. 2-3, Table 14 No. 2-3 and Table 17, No. As is clear from 2-3, the molded product having a density of substantially 0.3 g / cm ³ or more shows a remarkable degree of preferential orientation of 3 or more. On the other hand, each table No. 1, No. Two
As can be seen from the sample, the density is substantially 0.3 g / cm
^The molded body of less than ³ is compressed and deformed in a state where the presence of secondary particles that can be observed with a microscope can be confirmed as described above.
The state and degree of compression deformation of the spherical secondary particles are determined by the molding conditions of the spherical secondary particle crystal slurry. Although the addition of the additive material affects the density of the molded body, it does not affect the state and degree of compression deformation of the spherical secondary particles constituting the molded body. Therefore, the state and degree of compressive deformation of the spherical secondary particles forming the molded article obtained by adding the additive to the spherical secondary particle crystal slurry and molding the additive from the crystal slurry containing the additive The state and degree of compressive deformation of the spherical secondary particles constituting the compact obtained by compacting the same removed crystal slurry under the same molding conditions as when the additive was added are not substantially different.

The preferential orientation of the original molded body satisfies a certain relationship represented by the following equation, where the degree of orientation is P and the density is x.

P ≧ ax−b (where 0.3 ≦ x. Both a and b change depending on the added amount, and when there is no additive, a is 20 and b.
Indicates 3.).

The degree of preferential orientation is measured by the following method. A part of the compact is sampled and finely pulverized to make a non-oriented powder sample, while another sample having a plane perpendicular to the press direction is made from the compact (oriented sample), and then two samples of tobermorite The X-ray diffraction intensities of the (002) and (220) planes of the crystal are measured, respectively.

The preferred orientation degree (P) is

[0033]

[Chemical 3] Is given by

Here, I (002) and I (220) are diffraction intensities of the non-oriented powder sample, and I '(002) and I' (22).
0) is the diffraction intensity of the oriented sample.

The molded product of the present invention is characterized in that the above-mentioned degree of preferential orientation is very large. As described above, the orientation is the degree to which the tobermorite crystals present in the compact are arranged in a certain direction due to the pressure during molding, and only in the compact composed of spherical secondary particles interconnected. Although it is a peculiarity to be recognized, its preferential orientation is particularly dependent on the number of secondary particles per unit area that are subject to compressive deformation due to pressure during molding and the packing density of crystals on the surface of each secondary particle. different. The molded product of the present invention has a characteristic that the density is substantially 0.3 g / cm ³ or more, and the preferential orientation is particularly large, as compared with the conventionally known molded product composed of spherical secondary particles of tobermorite. However, this is because the molded article of the present invention is composed of hollow or coarse spherical secondary particles having a low density (that is, a large number per unit area) and an internal hollow ratio of 30% or less. Therefore, the degree of preferential orientation is remarkably large at the same density.

As described above, the molded product of the present invention is composed of tobermorite crystals, and these crystals form the above-mentioned unique spherical secondary particles, and these secondary particles are connected to each other. In comparison with the above-mentioned conventional tobermorite molded body, it has extremely low density and has sufficient practical strength.

The molded article of the present invention will be described below by its manufacturing method.

The molded article of the present invention is, for example, spherical secondary particles before molding, that is, spherical secondary particles formed by three-dimensionally intertwining tobermorite crystals, and the outer diameter thereof is about 10 to about. Average apparent density of 0.14 to 0.21 g / c at 120 μm
It can be produced by molding and drying an aqueous slurry in which spherical secondary particles having a coarse or hollow interior in m ³ are dispersed in water.
By being produced from an aqueous slurry as described above,
The desired characteristics are exhibited. That is, when the above slurry is molded, water existing between the secondary particles easily escapes from between the particles, and the molding pressure uniformly acts on the entire slurry. The water present in the hollow or coarse portions inside the particles resists the above-mentioned pressure and is compressed and connected to each other while maintaining the particle shape without destroying it.
Following this decrease in interparticle water, the water inside the particles is gradually discharged. Therefore, if the molded product obtained after the dehydration molding is dried, the water inside the particles is completely discharged and thus a molded product having a desired low density and high strength can be obtained.

The ratio of water to solid content of the aqueous slurry used in the above method is not particularly limited, but it is preferably 3 times (weight) or more, preferably about 5 to 30 times (weight). Further, this aqueous slurry may contain various additives as required. As a result, the tobermorite molded product of the present invention, which is a composite of various additives, can be obtained. Here, as the additive material, for example, asbestos, rock wool,
Inorganic fibers such as glass fiber, ceramic fiber, carbon fiber and metal fiber, animal and vegetable fibers such as pulp, cotton, hemp, wool and wood fiber, and reinforcing materials such as rayon, polyacrylonitrile, polypropylene, polyamide, polyester and other organic synthetic fibers. The fibrous substance can further improve the mechanical strength, hardness, and other characteristics of the molded body, and further improve the moldability. In particular, the fibrous material serves to increase the mechanical strength of the shaped body. In addition, various clays can be used for improving heat resistance, and further, cements, gypsum, colloidal silica, alumina sol for reducing or eliminating shrinkage at the time of drying after molding or for increasing the surface strength of the molded body. Alternatively, a phosphoric acid-based or water glass-based binder or the like may be added. It is also possible to interpose a wire net, a metal streak or the like. In the present invention, examples of the molding means for molding the aqueous slurry into a molded product include a natural sedimentation method, a mold injection method, a press dehydration molding method, a centrifugal molding method and the like.

Further, the tobermorite molded product produced as described above is fired to transform the tobermorite crystals constituting the same into β-wollastonite crystals to obtain a β-wollastonite molded product. .

The above-mentioned calcination is easily carried out under a temperature condition which is equal to or higher than the temperature at which tobermorite transforms into β-wollastonite. Generally, it may be heated at 800 ° C. or higher, for example, 850 ° C. for about 3 hours. Further, since the molded body composed of the β-wollastonite crystal requires heating, the additive material added to the molded body is not substantially changed by heating such as the above-mentioned inorganic fibers and clay binder. Must be inorganic. Thus, the crystals constituting the molded body are transformed into β-wollastonite crystals, and a molded body in which various inorganic additives are compounded is obtained as necessary.

The aqueous slurry of spherical secondary particles for producing the above-mentioned molded article of the present invention can be easily produced, for example, by the following method. That is, lime milk having a sedimentation volume of 5 ml or more and silicic acid mainly containing crystalline are mixed so that the amount of water to solid content is 15 times (weight) or more to form a raw material slurry, which is heated and stirred under pressure. A hydrothermal synthesis reaction can be performed to obtain an aqueous slurry of spherical secondary particles composed of tobermorite crystals. At this time, the sedimentation volume of 5 ml or more means lime milk prepared by increasing the ratio of water to lime solids by 120 times.
0 ml was put in a cylindrical container having a diameter of 1.3 cm and a volume of 50 ml or more, and after standing for 20 minutes, the volume of lime settled is shown in ml. The large settling volume means that lime is well dispersed in water and in a stable state, that is, it is composed of extremely fine particles, and thus exhibits high reactivity. Since the molded product of the present invention is manufactured from the spherical secondary particles having the above-mentioned characteristics by using the highly reactive lime as described above, it has low density and sufficient practical strength. .

In the above production method, it is essential to use lime milk having a sedimentation volume of 5 ml or more and having extremely excellent dispersion stability. If lime milk whose sedimentation volume does not reach 5 ml is used, the above-mentioned unique spherical secondary particles cannot be obtained. The method itself for producing lime milk having a sedimentation volume of 5 ml or more used is secondary and is not particularly limited. The settling volume of this lime milk depends on the limestone itself as a raw material, the firing temperature during lime production, the amount of water when slaked lime into water, the temperature at that time, the stirring conditions at that time, etc. Although it is greatly affected by the temperature and stirring conditions at the time of medium digestion, it is not possible to obtain the desired lime milk having a sedimentation volume of 5 ml or more by the usual method for producing lime milk.
Thus, for lime milk having a sedimentation volume of 5 ml or more, typically, the ratio of water to lime content (solid content) is 5 times (weight) or more, and the mixture may be stirred at a high temperature or at high speed, preferably at a temperature of 60 ° C. or more. For example, the desired lime milk can be obtained by vigorous stirring with a homomixer. The stirring speed and stirring strength can generally be lowered by increasing the temperature and time during stirring. Various types of stirrers are used, and those with or without a baffle plate can be used. Various kinds of lime can be used as a lime raw material used for producing lime milk, and for example, quick lime and slaked lime are suitable because they can increase the sedimentation volume most.

The silicic acid raw material used for producing the aqueous slurry of spherical secondary particles in the present invention is
A crystalline silicic acid raw material is used. For example, quartzite, quartz, sandstone quartzite, cohesive quartzite, recrystallized quartzite, complex quartzite, quartz sand,
Examples include silica stones. These silicic acid raw materials generally have an average particle size of 30 μm, preferably 1 to 20 μm or less. The above-mentioned silicic acid raw material may further contain amorphous silicic acid as long as it contains a crystalline silicic acid raw material as a main component, and the amorphous silicic acid is converted into crystalline silicic acid in an amount of 50% (by weight) or less. It can also be mixed and used. As the silicic acid raw material, a material having a relatively high Al ₂ O ₃ content can be used,
Usually, if it is about 5% or less, it can be sufficiently used. The mixing molar ratio of lime and silicic acid is 0.70 to 0.95, which is a desirable molar ratio for producing tobermorite or other crystals of calcium silicate.

The lime milk and the silicic acid raw material are mixed to prepare a raw material slurry having a water-to-solid content ratio of 15 times (by weight) or more, which is then subjected to a hydrothermal synthesis reaction while heating and stirring under pressure. The reaction conditions such as pressure, temperature and stirring speed at this time are appropriately determined depending on the reaction vessel used for the reaction, the stirrer, the type of reaction product and the like. The temperature and pressure in the hydrothermal reaction are usually 5 kg / cm ² or more. The time can be shortened by increasing the temperature and pressure, but it is economically preferable that the reaction time is short, but considering the safety during operation, it is preferably 10 hours or less. An example of preferable conditions is, for example, a saturated vapor pressure of 3 kg at 12 kg / cm ² .
The time is about 6 hours at 8 kg / cm ² . The stirring in this hydrothermal synthesis reaction is appropriately determined according to the raw materials used, the reaction vessel and the reaction conditions. For example, diameter 150mm,
When a sliding stirring blade is used in a reaction vessel with a volume of 3 liters, when a silica stone powder with a lime milk sedimentation volume of 30 ml and an average particle size of about 5 μm is used as a raw material slurry at a water ratio of 24 times, the stirring speed is Is 100 r. p. It is about m. As a stirring operation, the reaction vessel itself may be rotated, vibrated,
It is possible to exemplify various stirring operations such as pressurizing gas or liquid. The hydrothermal reaction may be a batch type reaction or a continuous reaction. When performing the continuous reaction, the raw material slurry is continuously pressed into the reaction vessel and the synthetic slurry (calcium silicate crystal slurry) after the reaction is discharged under normal pressure. Good. Secondary particles need to be kept intact during this discharge. Alternatively, the water ratio of the raw material slurry may be reduced to cause the reaction in the reaction vessel, and after the reaction, a predetermined amount of water may be pressed and discharged.

When synthesizing the calcium silicate, a reaction accelerator, a catalyst, a suspending agent and the like can be appropriately added to the raw material slurry. Examples thereof include wollastonite and calcium silicate hydrate, as well as various salts of alkali and alkali metals such as caustic soda and caustic potash. The addition amount of the above-mentioned additive is not particularly limited as long as the intended spherical secondary particles of calcium silicate crystals can be obtained, but wollastonite and the like are usually preferably up to about 30% by weight.

In order to obtain an aqueous slurry of spherical secondary particles for producing the molded product of the present invention by a hydrothermal synthesis reaction from a raw material slurry prepared from the above specific lime milk and a silicic acid raw material, the raw material slurry is Further, inorganic fibers such as asbestos, alkali resistant glass fibers, ceramic fibers and rock wool, and organic fibers such as alkali resistant pulp can be further added. By this operation, an aqueous slurry in which spherical secondary particles and fibers are uniformly dispersed in water is obtained. This aqueous slurry differs from the one obtained by adding fibers to an aqueous slurry of spherical secondary particles obtained by subjecting the above-mentioned raw material slurry to a hydrothermal synthesis reaction in the following points. That is, in the former case, since the silicic acid raw material and the lime raw material in the raw material slurry are crystallized on the fibers and spherical secondary particles are formed at the same time, spherical secondary particles entangled or bonded to the fibers are easily generated. On the other hand, in the latter case, the fiber and the spherical secondary particle are not bonded in principle because the fiber is added after the crystallization and the formation of the spherical secondary particle. Due to such a difference, the mechanical strength of the molded product of the present invention obtained from this kind of aqueous slurry tends to be slightly higher in the former case.

Examples for clarifying the features of the present invention will be shown below. In the following examples, parts or% means parts by weight or% by weight unless otherwise specified. Example 1 42.25 parts of quicklime (CaO 95.0%) was hydrated in 507 parts of hot water at 80 ° C. and dispersed in water with a homomixer for 3 minutes to obtain a lime milk having a sedimentation volume of 18.9 ml. there were. Silica powder (S with an average particle size of about 9 μm) (S
iO ₂ 97.37%, Al ₂ O ₃ 0.99%) 5
3.21 parts were added and the total amount of water was mixed to be 22 times the solid content by weight to obtain a raw material slurry, which was saturated water vapor pressure 12 kg / cm ² , temperature 191 ° C. and volume 3000 c.
c, rotation speed of 174 r.m. in an autoclave having an inner diameter of 15 cm.
p. The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. 100% of this crystal slurry
It was confirmed that the crystals were tobermorite when dried at 24 ° C. for 24 hours and analyzed by X-ray diffraction.

When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 38 μm were observed as shown in FIG. Further, a surfactant was added to and mixed with the slurry, allowed to stand for 48 hours for spontaneous precipitation, and then dried at 100 ° C. for 48 hours to cut out a part of the spontaneous precipitation molded body, which was fixed with Canadian balsam. Then, after polishing this, the above Canadian balsam was removed with xylene to obtain a polishing sample. When this sample was observed with a scanning electron microscope, it was found that the tobermorite crystals coarsely aggregated to form spherical secondary particles as shown in FIG.

When the secondary particles are dispersed and observed by an electron microscope, the length is 0.1 to 10 μm, as shown in FIG.
A plate crystal having a width of 0.1 to 2 μm and a length of 0.1 to 10 μm,
Needle-like crystals with a width of 0.05 to 0.5 μm were observed.

The characteristics of the secondary particles are shown in Table 1.

[0052]

[Table 1] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The degree of preferential orientation of the original molded product obtained by drying at 20 ° C. for 20 hours is shown in Table 2.

[0053]

[Table 2] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the obtained molded product are shown in Table 3.

[0054]

[Table 3] Example 2 41.42 parts of quicklime (CaO 95.1%) was dissolved in 497 parts of hot water at 80 ° C. and dispersed in water with a homomixer for 5 minutes to obtain a lime milk having a sedimentation volume of 17.5 ml. there were. Silica powder (SiO ₂ 94.03%, Al ₂ O ₃ 2.37%) with an average particle size of about 8.5 μm is added to the lime milk.
54.04 parts were added and the total amount of water was mixed to be 22 times the solid content by weight to obtain a raw material slurry, which was saturated water vapor pressure 12 kg / cm ² , temperature 191 ° C. and volume 3000.
Rotation speed 174 in an autoclave with cc and inner diameter of 15 cm
r. p. The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. 1 of this crystal slurry
When it was dried at 00 ° C. for 24 hours and analyzed by X-ray diffraction, it was confirmed to be tobermorite crystals. When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 52 μm were recognized. In addition, a surfactant was added to the slurry and mixed, and the mixture was allowed to stand for 48 hours,
A portion of the natural sedimentation molded body obtained by allowing it to spontaneously sediment and then drying it at 100 ° C. for 48 hours was cut out, fixed with Canadian balsam, and then ground to remove the Canadian balsam with xylene. A polished sample was obtained. When this sample was observed with a scanning electron microscope, it was found that the tobermorite crystals were coarsely aggregated and spherical secondary particles having a hollow inside were formed as shown in FIG.

When the secondary particles are dispersed and observed by an electron microscope, plate-like crystals having a length of 0.1 to 10 μm and a width of 0.1 to 2 μm and a length of 0.1 to 10 μm and a width of 0.05 to 0 are obtained. .5
Needle-like crystals of μm were observed.

The characteristics of the secondary particles are shown in Table 4.

[0057]

[Table 4] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The preferential orientation degree of the original molded product obtained by drying for 20 hours was as shown in Table 5.

[0058]

[Table 5] Further, a part of the molded body (Sample No. 1) shown in Table 5 was cut out, fixed with Canadian balsam, then polished, and then the polished sample obtained by removing the Canadian balsam with xylene was used as a scanning electron. Observation with a microscope reveals that the spherical secondary particles are interconnected as shown in FIG.

Next, to 85 parts (solid content) of the crystal slurry obtained above, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement were added as an additive, press-molded in the same manner, and dried at 120 ° C. for 20 hours. To obtain a molded body. The physical properties of the obtained molded product are as shown in Table 6.

[0060]

[Table 6] Example 3 45.56 parts of quicklime (CaO 95.6%) was dissolved in 547 parts of hot water at 80 ° C. and dispersed in water with a homomixer for 6 minutes to obtain a lime milk having a sedimentation volume of 28.0 ml. there were. Silica powder (SiO ₂ 94.03%, Al ₂ O ₃ 2.37%) with an average particle size of about 8.5 μm is added to the lime milk.
A raw material slurry was obtained by adding 59.44 parts and mixing the total amount of water to be 20 times the solid content, and saturating a steam pressure of 8 kg / cm ^{2 at} a temperature of 175 ° C. and a volume of 3000 c.
c, rotation speed of 174 r.m. in an autoclave having an inner diameter of 15 cm.
p. The hydrothermal synthesis reaction was carried out for 6 hours while rotating the stirring blade at m to obtain a crystal slurry. 100% of this crystal slurry
It was confirmed that the crystals were tobermorite when dried at 24 ° C. for 24 hours and analyzed by X-ray diffraction. When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 45 μm were recognized. Further, a surfactant was added to the slurry and mixed, allowed to stand for 48 hours to spontaneously settle, and then dried at 100 ° C. for 48 hours to cut out a part of the naturally settled molded body, which was fixed with Canadian balsam. Then, after polishing this, the above Canadian balsam was removed with xylene to obtain a polishing sample. Observation of this sample with a scanning electron microscope revealed that the tobermorite crystals aggregated coarsely to form spherical secondary particles.

When the secondary particles are dispersed and observed by an electron microscope, plate-like crystals having a length of 0.1 to 10 μm and a width of 0.1 to 2 μm and a length of 0.1 to 10 μm and a width of 0.05 to 0 are obtained. .5
Needle-like crystals of μm were observed.

The characteristics of the secondary particles are shown in Table 7.

[0063]

[Table 7] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The degree of preferential orientation of the original molded product obtained by drying for 20 hours was as shown in Table 8.

[0064]

[Table 8] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the obtained molded product are as shown in Table 9.

[0065]

[Table 9] Example 4 45.83 parts of quicklime (CaO 95.0%) was dissolved in 550 parts of hot water at 80 ° C. and dispersed in water for 7 minutes with a homomixer to obtain a lime milk having a sedimentation volume of 31.6 ml. there were. Silica powder (SiO ₂ 95.01%, Al ₂ O ₃ 3.27%) having an average particle diameter of about 1.6 μm is added to the lime milk.
59.17 parts were added and the total amount of water was mixed to be 20 times the weight of the solid content to obtain a raw material slurry, which was saturated water vapor pressure 12 kg / cm ² , temperature 191 ° C. and volume 3000.
Rotation speed of 112 in autoclave with cc and inner diameter of 15 cm
r. p. The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. 1 of this crystal slurry
When it was dried at 00 ° C. for 24 hours and analyzed by X-ray diffraction, it was confirmed to be tobermorite crystals. When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 24 μm were recognized. In addition, a surfactant was added to the slurry and mixed, and the mixture was allowed to stand for 48 hours,
A portion of the natural sedimentation molded body obtained by allowing it to spontaneously sediment and then drying it at 100 ° C. for 48 hours was cut out, fixed with Canadian balsam, and then ground to remove the Canadian balsam with xylene. A polished sample was obtained. When this sample was observed with a scanning electron microscope, it was found that the tobermorite crystals were coarsely aggregated and spherical secondary particles having a hollow inside were formed.

When the secondary particles are dispersed and observed by an electron microscope, plate-like crystals having a length of 0.1 to 10 μm and a width of 0.1 to 2 μm and a length of 0.1 to 10 μm and a width of 0.05 to 0 are obtained. .5
Needle-like crystals of μm were observed.

The characteristics of the secondary particles are shown in Table 10.

[0068]

[Table 10] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The preferred orientation degree of the original molded product obtained by drying for 20 hours at 11
It was as shown in the table.

[0069]

[Table 11] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the obtained molded product are as shown in Table 12.

[0070]

[Table 12] Example 5 42.23 parts of quick lime (CaO 95.0%) was dissolved in 507 parts of hot water at 80 ° C. and dispersed in water for 6 minutes with a homomixer to obtain a lime milk having a sedimentation volume of 26.0 ml. there were. Silica powder (SiO ₂ 95.01%, Al ₂ O ₃ 3.27%) having an average particle diameter of about 1.6 μm is added to the lime milk.
A raw material slurry was obtained by adding 53.23 parts and mixing the total amount of water to be 20 times the solid content by weight, and saturating a steam pressure of 12 kg / cm ^{2 at} a temperature of 191 ° C. and a volume of 3000.
Rotation speed of 112 in autoclave with cc and inner diameter of 15 cm
r. p. The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. 1 of this crystal slurry
When dried at 00 ° C. for 24 hours and subjected to X-ray diffraction analysis, it was confirmed that the tobermorite crystals were mixed with a small amount of zonotolite crystals. When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 31 μm were recognized. Further, a surfactant was added to the slurry and mixed, allowed to stand for 48 hours to spontaneously settle, and then dried at 100 ° C. for 48 hours to cut out a part of the naturally settled molded body, which was fixed with Canadian balsam. Then, after polishing this, the above Canadian balsam was removed with xylene to obtain a polishing sample. When this sample was observed with a scanning electron microscope, it was found that the tobermorite crystals and a small amount of zonotolite crystals were roughly aggregated and that secondary particles having a hollow inside were formed.

Table 13 shows the respective properties of the secondary particles.

[0072]

[Table 13] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The degree of preferential orientation of the green body obtained by drying for 20 hours at 14
It was as shown in the table.

[0073]

[Table 14] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the obtained molded product are as shown in Table 15.

[0074]

[Table 15] Example 6 42.25 parts of quicklime (CaO 95.0%) was hydrated in 507 parts of hot water at 80 ° C. and dispersed in water for 2 minutes with a homomixer to obtain a lime milk having a sedimentation volume of 8.1 ml. there were. Silica powder (Si having an average particle size of about 9 μm) (Si
O ₂ 97.37%, Al ₂ O ₃ 0.99%) 53.
21 parts was added and the total amount of water was mixed to be 22 times the solid content by weight to obtain a raw material slurry, which was saturated water vapor pressure 12 kg / cm ² , temperature 191 ° C., volume 3000 cc,
Rotation speed of 174 r.m. in autoclave with inner diameter of 15 cm. p.
The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. When this crystal slurry was dried at 100 ° C. for 24 hours and subjected to X-ray diffraction analysis, it was confirmed to be tobermorite crystals. When this crystal slurry was dried on a slide glass and observed by an optical microscope, spherical secondary particles having an average outer diameter of 47 μm were recognized. Further, a surfactant was added to the slurry and mixed, allowed to stand for 48 hours to spontaneously settle, and then dried at 100 ° C. for 48 hours to cut out a part of the naturally settled molded body, which was fixed with Canadian balsam. Then, after polishing this, the above Canadian balsam was removed with xylene to obtain a polishing sample. Observation of this sample with a scanning electron microscope revealed that the tobermorite crystals aggregated coarsely to form spherical secondary particles.

When the secondary particles are dispersed and observed by an electron microscope, plate-like crystals having a length of 0.1 to 10 μm and a width of 0.1 to 2 μm and a length of 0.1 to 10 μm and a width of 0.05 to 0 are obtained. .5
Needle-like crystals of μm were observed.

The characteristics of the secondary particles are shown in Table 16.

[0077]

[Table 16] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The degree of preferential orientation of the original molded product obtained by drying for 20 hours at
It was as shown in the table.

[0078]

[Table 17] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the resulting molded product are shown in Table 18.

[0079]

[Table 18] Comparative Example 1 The sedimentation volume of lime milk obtained by soaking 42.25 parts of quick lime (CaO 95.0%) in 507 parts of hot water at 80 ° C. was 4.
It was 0 ml. Silica powder (SiO ₂ 97.37%, Al ₂ O ₃ 0.9) with an average particle diameter of about 9 μm was added to the lime milk.
9%) 53.21 parts were added to bring the total amount of water to 22% of the solid content.
A raw material slurry was obtained by mixing so that the weight of the raw material slurry was 12 kg / cm ² , the temperature was 191 ° C., and the volume was 3
Rotation speed of 1 in an autoclave with 000 cc and an inner diameter of 15 cm
74r. p. The hydrothermal synthesis reaction was performed for 3 hours while rotating the stirring blade at m to obtain a crystal slurry. When this crystal slurry was dried at 100 ° C. for 24 hours and subjected to X-ray diffraction analysis, it was confirmed to be tobermorite crystals. When this crystal slurry was dried on a slide glass and observed with an optical microscope, spherical secondary particles having an average outer diameter of 48 μm were recognized.
Further, a surfactant was added to the slurry and mixed, allowed to stand for 48 hours to spontaneously settle, and then dried at 100 ° C. for 48 hours to cut out a part of the naturally settled molded body, which was fixed with Canadian balsam. Then, after polishing this, the above Canadian balsam was removed with xylene to obtain a polishing sample. Observation of this sample with a scanning electron microscope revealed that the tobermorite crystals were densely aggregated to form spherical secondary particles.

When the secondary particles are dispersed and observed with an electron microscope, plate crystals having a length of 0.1 to 10 μm and a width of 0.1 to 2 μm and a length of 0.1 to 10 μm and a width of 0.05 to 0 are obtained. .5
Needle-like crystals of μm were observed.

The characteristics of the above secondary particles are as shown in Table 19.

[0082]

[Table 19] Also, the crystal slurry obtained above is press-molded, and the temperature is 120 ° C.
The degree of preferential orientation of the green body obtained by drying for 20 hours at 20
It was as shown in the table.

[0083]

[Table 20] Next, 7 parts of glass fiber, 5 parts of pulp and 3 parts of Portland cement as an additive are added to 85 parts (solid content) of the crystal slurry obtained above, and press-molded in the same manner to 120 ° C.
And dried for 20 hours to obtain a molded body. The physical properties of the obtained molded product are as shown in Table 21.

[0084]

[Table 21]

[Brief description of drawings]

1 shows a 100 × optical micrograph of spherical secondary particles of tobermorite crystals of Example 1. FIG.

FIG. 2 shows an electron micrograph at 7500 times in which spherical tobermorite crystal secondary particles of Example 1 were dispersed.

FIG. 3 shows a scanning electron micrograph (600 times) of a polished surface of a spontaneous sedimentation molded article of Example 1.

FIG. 4 shows a scanning electron micrograph (600 times) of a polished surface of a spontaneous precipitation molded body of Example 2.

FIG. 5 shows a scanning electron micrograph (600 times) of a polished surface of a tobermorite molded article of the present invention (density 0.201 g / cm ³ ) of Example 2.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C04B 14:42 Z 16:02) A 111: 28 111: 40

Claims (2)

[Claims] 1. A substantially spherical secondary particle formed by three-dimensionally intertwining tobermorite crystals or a small amount of other calcium silicate crystals, and an additive material added if necessary.
Seen, is constructed by interconnecting the secondary particles is compressed and deformed
A shaped bodies, (1) the density of the raw molded body containing no added material substantially
Molding with 0.3g / cm ³ or more or addition of additives
The density of the original compact corresponding to the body is substantially 0.3 g / cm
When the number is ³ or more, individual spherical secondary particles constituting the molded body
Is a scanning electron microscope (600 times)
When I guessed it, it was compressed and deformed to the extent that its existence could not be confirmed.
Flattened, and the original molded body or corresponding original molding
The body is an excellent one represented by the formula P ≧ 20x−3 (where x is the density of the original molded body).
It has a degree of pre-orientation (P), and (2) the density of the original molding containing no additive is substantially
Molding when less than 0.3 g / cm ³ or addition of additives
The density of the original compact corresponding to the body is substantially 0.3 g / cm
When it is less than ^3, individual spherical secondary particles constituting the molded product
Is a scanning electron microscope (600 times)
Compressed to the extent that the presence of spherical secondary particles can be confirmed when inferring
Is deformed and, (3) above (1) and in any case of (2), spherical secondary particles an outer diameter before molding 10 to 120 [mu] m, the hollow ratio and 30% or less thereof A calcium silicate compact characterized by having a natural sedimentation compact density of 0.12 g / cm ³ or less. 2. Molded body according to claim 1, wherein the molded body contains at least one additive of fibrous material and binder.