JPS5841712A - Preparation of crystalline calcium silicate hydrate - Google Patents

Abstract

PURPOSE:To prepare crystalline calcium silicate hydrate having improved heat and fire resistance and heat insulating property on molding into a molded article, by the hydrothermal reaction of calcium silicate hydrate in hot water or hot aqueous solution of an alkali preheated to the reaction temperature. CONSTITUTION:Water or an aqueous solution of an alkali metallic hydroxide, e.g. NaOH or KOH, in about 1-2 N alkali concentration is introduced into an autoclave, and heated at 100-400 deg.C. 1pt.wt. calcium silicate hydrate, e.g. amorphous calcium silicate hydrate or hydrate of cement, is injected into 100pts.wt. hot water or hot aqueous solution of the alkali by a booster pump to carry out the hydrothermal reaction and give the aimed crystalline calcium silicate hydrate having improved heat and fire resistance and heat insulating property on molding into a molded article and lightweight properties in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing crystalline calcium silicate hydrate, and more specifically to a synthetic method using a hydrothermal reaction. This is related to LK.

There are 22 types of crystalline calcium silicate hydrates known. Among them, tobermorite, zonotrite, 7-oshyayite□, hireklandite, and jaiaite are among the most well-known.

Crystals with complex shapes such as llj-like, needle-like, fibrous, rough, and petal-like shapes have already been artificially synthesized.

Such crystalline calcium silicate hydrate □ has its heat insulating properties, high WIl properties, and also heat insulating properties when formed into a molded body,
In recent years, k has become popular as a building material, mainly for interior and exterior walls, as well as as a heat insulating material and lumber for various types of insulation, and has been used in industrial pots in large quantities. s side,
In addition to being used as molded objects, K11il can also be used as fillers for plastics, fragrances, and carriers for saima and tactile materials.
There are also attempts to use crystalline silicic acid powder, and research into materials that take advantage of the functions of crystalline silicate powder is also underway.

As a method for synthesizing crystalline calcium acid, silicic acid raw materials and calcareous raw materials are heated under saturated water vapor pressure.

The crystals are crystallized by reacting at a temperature of ℃ or higher.
Two so-called items that cost $8. Hydrothermal synthesis is a typical method. In this method, the raw material seeds lit.

Various different crystalline calcium silicate hydrates can be obtained by changing the conditions such as CaO/8sO, the addition of the three components, the degree of reaction, and the reaction time. I can □. This phoenix is also used in IEK construction as the II construction method for xonotlite and tobermorite, which are used as heat-insulating materials, cutting materials, and architectural wall materials.

However, this known method takes a lot of time to obtain highly crystalline calcium silicate hydrate #IIJ.

In addition, due to the slow crystal formation, unreacted substances are mixed in the product, and there are many problems in manufacturing.
When synthesizing fibrous calcium silicate hydrate in step 1, the reaction time ranges from several tens of hours to several days.
Therefore, the seeding of crystalline calcium silicate used as an industrial material has also been considered.

In order to eliminate such an interlayer, for example, amorphous silica, which is highly reactive as a silicate H group, is used as a raw material, or a silicate raw material and a calcareous raw material are reacted to form an amorphous calcium silicate hydrate. A method has been developed in which crystalline calcium silicate hydrate is produced by using the calcium silicate as an intermediate product and then reacting it under hydrothermal reaction conditions, as well as other methods.

Hydrogen synthesis reaction of calcium silicate hydrate starts with the starting material (j
2 of the hydration reaction with IIm of family I) and the crystallization reaction of the reaction product (amorphous calcium silicate hydrate) expected here.
It can be considered separately.

The inventors believed that it was necessary to speed up the crystallization process in order to improve the production reaction of crystalline calcium silicate hydrate, and as a result of intensive research, the conventional method We succeeded in discovering a method that could synthesize crystalline calcium silicate hydrate, which had not been obtained conventionally, in addition to overcoming the disadvantages of ** rpr-at members, and were successful in developing the present WA.

In other words, this li- adds calcium silicate hydrate to hot water or chicken alkaline water** set at a reaction temperature in advance, and causes a hydrothermal reaction to produce crystalline calcium silicate hydrate. This is a method for producing a crystalline silicic acid cal-V-rim hydrate.

Conventionally, amorphous calcium silicate hydrate in the form of a tree or amorphous calcicum silicate hydrate formed using a filter press or the like is placed in an autoclave, and after the apparatus is placed, a hydrothermal reaction is performed. A feature of the present invention is that calcium silicate hydrate is introduced into hot water or hot alkali which has been set at a reaction temperature in advance for reaction. Fortunately, according to the method of the present invention, the reaction time of crystalline calcium silicate hydrate, which took a long time to synthesize, can be drastically reduced! This is what iJI was able to do. For example, when praying for tobermorite crystals, the conventional method uses 3% at 180C.
In actual practice, it was possible to obtain tobermorite with good crystallinity in 1 hour (*1 Example 1).
．． (See Comparative Example 1).

It is hoped that calcium silicate water with good crystallinity will contribute to the effects of the present invention. For example, according to the present invention using amorphous silicate Calcium pentahydrate, crystalline tobermorite can be obtained compared to the conventional method, and 4IAK Hilleb 2
You can also pray for long crystals compared to Nite and Foshagite Yang Hecongwei (Jitsu II/IAfI
2 Reference II).

Below, IulQ will further comment on the origin of the present application.

Calcium silicate hydrate, which is the starting material used in the present invention, is obtained by hydrating the acidic MfI4Ik and the calcareous MfI4Ik under conditions of normal pressure to high silver pressure water or saturated steam. Calcium silicate hydrate. A typical example is so-called amorphous calcium 11tj hydrate, but also cement hydrate and ALC (
Calcium silicate hydrate tatami mats with partial KM molded parts such as autoclaves - raw materials - concrete are also used. Calcium silicate hydrate, which is a raw material, is added to the reaction IIK by adding it in a slurry form into water, but it can also be added in the form of a single piece such as a powder.

The water chicken reaction is a reaction that is carried out under conditions of high saturated water vapor pressure.
is used.

In this application li@, 嘗511&hon or hot alkaline water St refers to water or alkaline water S* that has been heated in a library by adding 1 mK of reaction. The temperature of the hot water or alkaline water S* to be heated is a degree to carry out the water chicken reaction.The membership fee is specified by the IC regulations, therefore, the ILIL range is 100 to 400.
This is the range of C. - In Kameirashi, where the water chicken reaction temperature is below 100CJjL, the skin becomes too thin and the effect of the present invention cannot be fully realized.On the other hand, at 400℃ or higher, the reaction equipment becomes large-scale and expensive. In addition, at temperatures above 400°C, the effect of accelerating the crystallization rate is small, even though the degree of haze is increased1.
Advantages of the present invention t - Crystalline calcium silicate hydrate that does not last long and the starting material calcium silicate JP41I! The optimum range is determined depending on the conditions of
A temperature of ~250°C is preferable to 41.

When using a thermal alkaline water moat, it is sufficient to have an alkali concentration of 5N 1 degree, but considering the purification of the resulting product, 1 to 2N 1 degree is preferable for 411! The alkali may be those commonly used such as alkali metal hydroxides, and sodium and potassium hydroxides are preferred.

According to the invention, the crystalline calcium silicate compound which has been subjected to C* by a hydrothermal reaction is dispersed in water or alkaline water II* in the form of a slurry and then taken out. 411I generated by filtration etc. After separating, washing and drying, it crumbles into white flour or flakes. The product obtained here had high crystallinity, as shown in xsss section (2) in Examples below.

I have explained above about the abundant harvest that constitutes the present invention, but it seems that crystalline calcium silicate hydrate has 11
aI is known, and there are various types of crystals, including woven and plate-like crystals.In carrying out the present invention, it is necessary to prepare the crystalline calcium silicate compound as described above. Needless to say, there is a prerequisite for membership fee.

Below, the invention of the present application will be explained in more detail with reference to examples.
Book! l- is not specified in these examples ~1
The conditions for adjusting X-ray diffraction in Examples and Comparative Examples are as follows.

-@C1 Filter N- Tube voltage 30 sections ■ Tube current ■ Number of needles in 1 muffle scale l・so・p$ Comprehensive degree of difference #Jl/min Example 1゜Starting material cement-based amorphous silicon Calcium acid (0
8H gel) is ordinary Portland cement (Ca0=6
5%, 810. =22%) 60 weight @, 7za silicon dust (810, = 89.%) 4.0 weight, C Hatake/84
(mole ratio): o, s, water/1 m-product (weight ratio n=i.

51! at 90-100°C. After the reaction was heated and stirred for a while, a slurry was obtained. This dried material x11
The diffraction diagram is shown in Figure 1. As is clear from Figure 1, this material is mostly amorphous calcium silicate (08H gel) and unreacted cement minerals (C, B, C).
1B) remained.

Put 1G0] [amount S of water in the autoclave, 1110
After heating to .degree. C., 1 part by weight of the above-mentioned CSM glue slurry was pressurized using a pressure pump.

After reacting for 1 hour at 1OC, the contents were cooled in autoclave 1 and taken out, and the contents were in the form of a slurry. The product of the present invention obtained by drying this slurry at 105C±5C after -j1 was a gray-white flaky powder crystal.

X1li of the invention! It is shown in IN chapter 00■. In Figure 2, the product of the present invention was 14 crystalline topamoite.

The product of the present invention is bulky, so it is the best for chicken fiberization! l Mari fat, thermoplastic*
It was confirmed through experiments that the airer ** can be used as a chicken paint.

Comparative Example 1 1 part by weight of slurry of 08M gel, same as 1 ml, 10 parts by weight of water
0 weight s in an autoclave for 30 minutes *SO
After heating at C* and reacting at 1110c for 3 hours,
The autoclave was cooled. Dump the contents HA LPj
ll & 105ct s Cte IEIi +, *lianning k
There was almost no change from the C8R group that was captured at the time of the X1L release.

Kan III Confucian 1 The starting material, calcium silicate (csn), is
White carbon (81 false = 8@%) 32 parts by weight.

Slaked lime (Ca9w74%) 6B parts by weight, 01078i0
．． (-%#*) Medium size, water/surpass carving (weight ratio) = 10f
) A mixture was prepared by heating and stirring at about 10C for 5 hours. This canda A-#)
It is shown in Figure 4, which is a photograph of the waterfall survey.

The product of the present invention is #i-) i1c 2 7/l F) 4 hydroxyl in an inned autoclave (inner volume 500aj)
ni,su)! j? Approximately 1 of the internal volume of the autoclave
/ Two people closed the autoclave and heated it to 250°C, then pressurized the CBH glue slurry described above in an amount of about 174 volumes of the autoclave using a pressure pump, held it at 250°C for 5 hours to undergo a hydrothermal reaction, and then cooled it. \FIJlk was washed with water and dried at tosc±5°C. This X@ diffraction curve is shown in Figure 5, and the scanning electron microscope photograph is shown in Figure 6. : As is clear from Figure JP5 and Figure 6, the product of the present invention is highly crystalline hireplandite, and its crystal shape is fibrous, and the average length of the crystals is ↓100.

Since the product of the present invention is in the form of white flakes, it has a thermosetting property of 5.
tir, thermoplastic filler, protective carrier, Pd2
It could be used as a material.

Ratio $9112゜cone lined autoclave (inner volume 1500m)
Medium tczmo) L/It) Sodium hydroxide 9M water 111 [&
Approximately 172 of the internal volume, approximately 1/4 of the internal volume of 08H gel slurry V, the same as in implementation f12, was added, and 2! !
After raising the temperature with QCt and reacting at 160t for 5 hours, it was cooled in an autoclave, the contents were spewed out, and washed with water for 10 minutes.
11+ C The powder dried at 15℃ has a constant fine fruit with X*aIR, which is exactly the same as the C8H glue that appeared, but the change is -
I couldn't stand it.

Real 11afa3゜Copper lined autoclave (inner volume 1500-)
Pour 24 A/l of potassium hydroxide into the autoclave and heat it to 210C after 91M. A slurry (approximately 1/4 weight of the internal volume of the autoclave) consisting of 1 part by weight of 78% CaO = O0 -) and 10 parts by weight of water was pumped into the autoclave using a pressure pump, and heated at 210°C for 24 hours. After cooling the autoclave, the contents were poured out.
After washing with water PjI, the product obtained by drying at 101C±5°C was white and flaky. Off figure to one bell x11m1
Origami, 8 years old, showing the scanning electron microscope photograph of 0 years old 9 years old.
@ is the xiitlil folding diagram of the invention product.

A scanning electron II microscope photograph of the spear was shown ten times. spear 9
As is clear from the figures and Fig. 110, the product of the present invention was a symbiotic substance of hiresilandite and hoshagite, and its crystal shape was fibrous, with an average length of 1'00 jm.
-・□ It was found that the product of the present invention can be used for the same purposes as in Example 2.

Comparison fi3゜#l “inning autoclave (including $51,500)
-) with an internal volume of 2 moA/j potassium hydroxide water** of about 172, and the same Hebersky as in Example 3;
! 114F) Approximately 1/4 person ft,, *1 after jlFj'
After increasing the temperature to 210°C and reacting at 210°C for 24 hours, the autoclave was cooled. Contents t-Otori-dashi water f1. After P separation, the powder dried at 105° C.±5° C. was examined by X1lil folding and scanning electron St* mirror photography, and as a result, the quartz component that existed in E1 m in the Hebel at the time of starting was lost.

Everything else is the original 111, □:ta.

[Brief explanation of drawings]

Figures 1 and ** are the starting materials.
- is a scanning electron sll mirror photograph of Oka C8H Guru. 81
Figure 7 is an Xlam fold diagram of the starting material, calcium silicate hydrate (Hebel, iii-name), and fold 11 is its first scan electron beam. The second cabinet is the X-g folding of tobermorite, which is a lead product.
Figure sl5 is an xsat fold diagram of hireplandite, which is also a product of the present invention, and figure 6 is a scanning electron micrograph of the same, $
19aO is Hireshilandite, which is also a product of the present invention.
□The 110th XSa fold diagram of the symbiotic symbiotic is its SL-electron a mirror photograph. Applicant Asahi Kasei Industries, Ltd. Figure 13 " , ', ' 111 1-1 ・1 ;・Figure 4 @ 6g Turning waist - 1 " Turning type whip

Claims (1)

[Claims] 1. Crystallization characterized by adding calcium silicate hydrate to hot water or mature alkaline water III set at a reaction temperature in advance and producing crystalline calcium silicate hydrate through a water-poultry reaction. Method for producing calcium acid hydrate for sexual use