JPS5824387B2 - Mukikai Koukatainoseiho - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention was made to provide a novel inorganic cured product with high strength.

Therefore, the present invention is based on calcium aluminate trisulfate hydrate [3CaO・Al2O3・3CaSO
4.21-32H20 hereinafter referred to as TSH] Ma or TS
H and calcium aluminate monosulfate hydrate (3CaO・A l 203 ・CaS 04 ・
12H20 (hereinafter referred to as MSH)] is the main component.

Inorganic cured products mainly composed of TSH or MSH have not been well known.

The present inventors have demonstrated that it is possible to produce a cured product using TSH or MSH and use it for various purposes, such as as a building material.

Therefore, the present invention attempts to further increase the usefulness of TSH and MSH by curing them using a special method.

The present invention will be explained in detail below.

The present invention provides a method for producing a cured body, which is characterized in that it takes the form of an excipient using MSH and masonry wax, converts some or all of the MSH into TSH, and blends an organic polymer substance. This is what we provide.

MSH used in the present invention may be obtained by any manufacturing method, for example, by combining CaO component raw material and A
It can be obtained by reacting the l2O3 component raw material and the gypsum component raw material.

CaO component raw materials include quicklime [CaO], slaked lime (C
a(OH:)2] is used.

Activated alumina, alumina hydrate (for example, boehmite, diasbore, gibbsite, payerite, etc.), aluminum hydroxide, etc. are used as the Al2O3 component raw material.

As the raw material for the plaster component, anhydrite wax, hemihydrate wax, dihydrate wax, etc. are used.

The reaction involved 2.4 to 3.5 moles of CaO component raw materials, Al2O3
Component raw material 0.8 to 1.2 mol, stone wax component raw material 0.8 to 1.2 mol
The reaction is carried out under moist heat at 100 to 200° C. by adding 1.2 mol of water and an amount of water necessary to ensure at least crystallization water of MSH.

In addition to the method described above, a method for producing MSH may include firing 3 moles of lime, 1 mole of alumina, and 6391 moles of alumina at 1100 to 1400° C. to obtain clinker made of C4AS, and then reacting the clinker with water.

Next, the organic polymer substances used in the present invention include natural substances such as starch, gelatin, and casein, water-soluble resins such as polyvinyl alcohol, urea resin, melamine resin, water-soluble phenol resin, polymethylol acrylamide, and polyacrylic acid; Water-insoluble resins such as polyvinyl acetate, polyacrylic ester, epoxy resin, ethylene-vinyl acetate resin, and phenol resin (in this case, preferably used as an emulsion) are used.

Of course, these can also be used in combination. Incidentally, among these substances, it is preferable to use those having a pH of 7 or more.

This is to avoid inhibiting the reaction in producing TSH from MSH.

In addition to the above, if necessary, fibrous reinforcing materials (pulp, wood flour, hemp, synthetic fibers, glass fiber, rock wool, asbestos, etc.) and fillers (silica powder, talc powder, clay, diatomaceous earth powder, alumina powder, etc.) ), release agents, pigments, and other additives may be added.

In addition, when using a fibrous reinforcing material, its blending ratio is not limited, but it is preferably 0.5 to 35% by weight (hereinafter abbreviated as "correspondence") based on the total solid content.

Of course, there is a more preferable blending range depending on the material of the reinforcing material.

For example, for glass fiber, it is 0.5 to 7, for asbestos, it is 1 to 35, and for organic fibers such as pulp, it is 1.
~10 units is appropriate.

In the present invention, MSH, gypsum and an organic polymer are used.

A child substance and water are mixed and shaped to produce a cured TSH body under moist heat.

Although it is not intended to limit the blending ratio of MSH and gypsum component raw materials (anhydrite, dihydrate, hemihydrate, etc.),
The number of moles of gypsum required to obtain TSH from MSH is secured.

The number of moles used is less than or equal to this amount.

Therefore, the amount of the gypsum component raw material is preferably 2 moles or less per 1 mole of MSH.

Of course, the amount may exceed 2 moles, but in this case, a large amount of gypsum remains in the finally obtained cured product, and the properties of gypsum appear.

In some cases, this may be undesirable.

For example, water resistance deteriorates.

Furthermore, if the gypsum component raw material is extremely small, MSH may not change into sufficient SH and it may be difficult to expect strength to be developed through crystal growth of TSH (this is not to say that the strength of MSH itself is bad).

Most preferably, a ratio of 1 mol for the former and 1.8 to 2.0 mol for the latter is adopted within an accuracy that can practically ensure a stoichiometric molar ratio.

Further, when 0.4 to 1.8 mol of the latter is used per 1 mol of the former, a cured TSH-MSH-organic polymer mixed system having a residual amount of gypsum of 1% or less can be obtained.

In addition, in the manufacturing process of MSH, it is also possible to use an excess of the gypsum component raw material in advance to obtain a mixture of MSH and gypsum, and use this mixture.

Although the amount of the organic polymer substance is not limited, it is preferably 0.5 to 10 times the total amount of MSH and gypsum.

Even if more than 10 parts are added, harmful effects (for example, flammability) may occur due to the increase in organic matter, or the improvement effect may not increase for certain performance, or in some cases, there is a tendency to inhibit the change from MSH to TSH. appears.

A mixture of MSH, gypsum and water in desired proportions can be shape hardened.

By curing this product under moist heat, MSH and gypsum can react and part or all of MSH can be changed into TSH.

At this time, the above additives may be added if necessary.

For example, a reinforced cured product can be obtained by adding a fibrous reinforcing material.

In the present invention, when covering, an organic polymer substance is contained in the cured product.

In the present invention, the timing of mixing is not limited as long as the organic polymer substance is eventually contained in the cured product.

For example, it may be added at the time of mixing MSH, gypsum, water and other additives, or it may be impregnated from the surface of the cured body after obtaining the cured body.

The former method has the disadvantage that the conversion of MSH to TSH may be inhibited, and the latter method requires time to reach the center of the cured body.

However, it is usually convenient from a process standpoint to adopt the former method using an organic polymer substance that does not inhibit the change from MSH to TSH.

The above raw materials are usually mixed by wet mixing, that is, in the presence of water, taking into consideration the convenience of shaping.

The presence of water is also necessary to generate TSH from MSH.

The shaping method is arbitrary.

An appropriate method is selected depending on the state of each raw material mixture obtained or the use of the excipient.

For example, a paper making method, an extrusion method, a casting method, a direct pressure pressing method, a roll pressing method, or a combination thereof may be employed.

Note that when the moisture content of the mixture is low, a direct pressure press method or a roll press method is used, and when it is high, a casting method or a papermaking method is used.

After shaping, it is subjected to moist heat curing and drying.

Moist heat curing is a process of carrying out a heating reaction in the presence of moisture, for example, in a state where a minimum amount of moisture (mostly required as crystal water) necessary for the change from MSH to TSH is secured.

The temperature is preferably 100°C or less, more preferably 40 to 95°C.
C is most preferred.

After moist heat curing, dry as necessary.

As explained above, the present invention obtains an excipient from MSH, gypsum, and water, performs moist heat curing, and if necessary, dries it.
Moreover, since it is characterized in that an organic polymeric substance is contained in any of the steps, the resulting cured product has excellent strength and does not suffer from chalking.

Example 1 Quicklime (first grade reagent) iso,y activated alumina (〃 ) 110g dihydrate (//
) 170g water
MSH is produced by reacting over 2,500g of raw materials in a 51 high-pressure reactor at 170°C with stirring for 180 minutes.
I got it.

The free gypsum contained in this product was 0.32%.

Next, 337 g of kerosene was added to the MSH, and 30 g of starch (tapioca), 12 g of asbestos, 6 g of glass fiber, and 2000 g of water were added and mixed uniformly.

Next, this was used to make a paper sheet with a thickness of +10 mrIL.

This was cured under humid heat for 4 hours at 60° C. in a tank with a humidity of 100 SR-H.

Next, it was dried at 45°C.

Low free gypsum (1.1%, based on hardened product) TSH-
A starch-based hardened product was obtained.

Generation of TSH was confirmed by X-ray diffraction of the cured product.

Figure 1 is the chart. In this, T is TSHlC
represents CaSO4.2H20.

Example 2 Kokuishikou 250 was added to MSH obtained in the same manner as in Example 1.
,? , polyvinyl alcohol 15g (water, 150g
), 400 g of water, 15 g of asbestos,
6 g of polypropylene fibers (length: 12 mm) were added and mixed uniformly.

Next, this mixture was made into a plate by a casting method.

Next, it was cured under humid heat at 40°C for 6 hours in an atmosphere of 100% R-H.

next. It was dried at 45°C to obtain an MSH-TSH-polyvinyl alcohol cured product.

The free gypsum content was 0.3% (based on the hardened product).

The X-ray diffraction chart of the cured product was as shown in FIG.

In this figure, M represents MSH. Example 3 MSH was obtained in the same manner as in Example 1, and this MSH633
13 g of acrylic resin emulsion (trademark: Dianal Lx-200, manufactured by Mitsubishi Rayon Co., Ltd.), 430 g of water, and 25 g of pulp were mixed and cast to a thickness of 10 mm.

Next, it was cured for 3 hours at 60° C. in a 100% R-H atmosphere.

Next, it was dried at 45°C to obtain a cured product.

The X-ray diffraction chart of this was as shown in FIG.

In addition, free gypsum was 0.s % <hardened body standard).

Comparative Example 1 A cured product of TSH was obtained in the same manner as in Example 1 without adding starch.

The hardened material contained 0.24% of free gypsum.

Comparative example 2 TSH500,! 7 asbestos 6.9. glass fiber 3
100g of water (Bi') was added and mixed uniformly.

Next, this was used to make a plate using the papermaking method, and the size was 10m1rL.
This was cured under moist heat for 4 hours in a bath of 100 SR, H at 60° C., and then dried at 45° C. to obtain a cured product.

Comparative Example 3 After adding 15 g of starch to the formulation of Comparative Example 2,
A cured product was obtained in the same manner as in Comparative Example 2.

The results of the above Examples and Comparative Examples are shown in the following table.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are X-ray diffraction charts.

Claims (1)

[Claims] 1. Calcium aluminate monosulfate hydrate, gypsum component raw materials, and water are mixed, this is shaped, and then cured under moist heat, dried if necessary, and an organic polymer substance is added at some stage of the process. Characteristic manufacturing method for inorganic cured products.