JPS61122148A - Gypsum composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a gypsum composition suitable for use as a plastering material applied to an organic foam heat insulating material.

[Conventional technology] In recent years, schools, hospitals, commercial buildings, apartment complexes, and various other
[For products, from the standpoint of energy saving, the aim is to provide the wall structure with higher insulation properties, and for this reason, foamed polystyrene boards, hard urethane foam, or foamed polyethylene boards, etc., which are particularly useful as insulation materials, are used as insulation materials. These organic foam insulation materials are used, and these insulation materials are attached to the inner wall side of the outer conocrete wall using a formwork-cum-driving method or a post-pasting method.

However, in the preparation of this kind of organic foam insulation material,
Currently, the following two methods are being implemented. One is the dry-type masonry board direct attachment method (hereinafter referred to as GL-pond), in which wall port adhesive (GL-pond) is kneaded into dumplings and placed on the F ground at regular intervals, and gypsum hoard is attached to this. The other method is the wet method, in which cement mortar, stone, or plaster is applied directly to the ground as a plastering material.
However, Boi's method has drawbacks such as easy internal condensation, mold, and poor impact resistance.
In addition, in the latter method, when known plastering materials are used, they often suffer from cracking and peeling after construction, which is an inconvenient problem.However, when these problems are compared and balanced, the latter Since the above problems are more serious and fatal, recently there are many cases in which the GLI method is adopted even if the above-mentioned drawbacks are accepted.

[Problems to be Solved by the Invention] Under the present circumstances, the present invention aims to solve the problem by wet-processing the inner wall surface of an organic foam insulation material base such as a foamed polystyrene board.
The idea is to make it possible to complete the process without any problems using the law. For this reason, in the present invention, it is possible to accurately solve the above-mentioned problems of cracking and peeling by applying it to the base of the heat insulating material, and it also has excellent impact resistance, sound insulation, and finished surface accuracy and surface cusp. The object of the present invention is to provide a new gypsum composition suitable for plastering for this type of application, which can constitute an interior wall surface.

Means for Solving Problem E 1 In order to achieve such a technical objective, the present invention provides 90 to 50 parts by weight of anhydrite to which a hardening accelerator is added and/or hemihydrate to which a retarder is added.

To a mixture consisting of 10 to 50 parts by weight of blast furnace water slag slab powder, 1 to 201 parts by weight of one or more of ethylene vinyl acetate resin, acrylic ester resin, and styrene butadiene synthetic rubber are added in terms of solid content. The present invention provides a gypsum composition characterized by:

The present invention will be explained in detail below.

The present inventors first mixed blast furnace water slag powder into a hydrofluoric anhydride compound prepared by adding a known hardening accelerator represented by an alkali metal sulfate to hydrofluoric anhydride neutralized with slaked lime. Furthermore, they have proposed a hydrofluoric anhydride plaster composition that provides an excellent high-strength cured product when a foam material 1 workability improving agent is added (Japanese Patent Laid-Open No. 55-230
Refer to Publication No. 29@), which uses the latent hydraulic properties of blast furnace water slag powder to obtain a hardened product with high strength even during high-temperature curing exceeding <30°C, such as in summer. However, through a series of these studies, the present inventor discovered another beneficial effect of blast furnace water slag powder, and utilized this property to create a new gypsum composition optimal for the above-mentioned plastering material. reached.

That is, ethylene vinyl acetate resin, ethylene vinyl acetate resin, When 1 to 20 parts by weight of at least one of acrylic ester resin or styrene-butadiene synthetic rubber is added in terms of solid content, an expandable hydrate, namely ettringite [C* A ' 3CaSO* ' 32H20]
The resin effectively grows within the bubbles entrained by the surface activity of the resin, and the resin fills between the hydrates of the gypsum and slag, resulting in high S tensile strength, low Young's half, and bending and bending properties. It has been confirmed that a cured product with excellent tensile strength can be obtained.

Regarding 1 cup of component mixing in the gypsum composition of the present invention,
...1. Hydrofluoric anhydrite added with hardening accelerator etc. -y9o~
50 m + Br part, blast furnace water ξ slag powder is 1
0 to 50 heavy darkness. This is because if the amount of slag powder is less than 10 parts, its expandability will not be suitable for the intended use, and if the force is more than 50 iT < -i ffi, the shrinkage of the slag hydrate will be affected This is because it comes out.

In addition, resin is the total amount of these single or combined amounts,
It is added in an amount of 1 to 20 parts by weight in terms of solid content. That is,
If the amount of additive is less than 1 part by weight, the desired physical properties such as expansivity, elastic modulus, bending and tensile strength cannot be obtained, and if it is more than 20 parts by weight, workability is poor and large-scale durability and price are lowered. This is because it is not desirable.

The above explanation has been based on the case where hydrofluoric anhydride is used as a gypsum raw material, but in the gypsum composition of the present invention, other types of anhydrite or hemihydrate can be used as well. . In other words, as a JIX material, part or all of fluorite anhydrite to which slaked lime for neutralization and a hardening accelerator have been added is calcined with ■-type anhydrite or natural ■-type anhydrite. Furthermore, even when α-type or β-type hemihydrate stone is replaced with hemihydrate gypsum containing known hardening N spreading agents such as carboxylic acid salts and some black isolate salts, It has been confirmed through actual trials that it exhibits similar characteristics, that is, a cured product with high expansibility, low elastic modulus, and excellent bending and tensile strength. It has low reactivity and does not harden easily even when mixed alone with water.Therefore, known hardening accelerators such as sodium sulfate, potassium sulfate, and potassium sulfate metal salts such as potassium aerobane are added. There is.

On the other hand, in the case of gypsum hemihydrate, when mixed with water, it hardens instantly and cannot be used as a plastering material, so the necessary retardant is added. The slaked lime added when using hydrofluoric anhydride gypsum is used to neutralize the sulfuric acid that remains as a by-product of this product, and of course requires mixing when using other types of gypsum raw materials. do not.

In the gypsum composition of the present invention, these different types of gypsum raw materials may be used alone or in a mixture of 8 kinds, and in either case, the mixed mackerel for the composition is This is the same as the claim scope for acid anhydride. In addition, when using a mixture of anhydrous 6-pan and kasui-1, it is sufficient to add the above-mentioned accelerator and retarder suitable for each type of gypsum.

When mixing the Ishiai aUJ & product of the present invention.

A mixture of anhydrite and/or hemihydrate mixed with required additives and blast furnace water slag slab powder is mixed with at least one of ethylene vinyl acetate resin, acrylic ester resin, or styrene-butadiene synthetic rubber. Sometimes they may be added as an emulsion together with water, or their powdered form may be premixed.

In addition, when using aggregate in the gypsum composition of the present invention, one or more types selected from river sand, sea sand, mountain sand, silica sand, agaric stone, crushed stone, calcined nacre, calcined obsidian, and calcined vermiculite are used. may be added in an amount ranging from 0.2 times to 4 times by volume per 1 gypsum composition.

[Operation] When the Stone No. 1 composition of the present invention described in 1- is used as a plastering material, it can be applied to the substrate of an organic foamed Wit thermal material with a very small elastic modulus, such as a foamed polystyrene board. However, cracking and peeling can be effectively prevented.

The reason for this is detailed below.

Generally, the conditions under which cracks occur are expressed by the following formula.

S n ε-+ GF +R5; Measuring shrinkage rate ε; Tensile elastic strain εP: Plastic strain R: Constraint relaxation rate By the way, the elastic modulus of organic foam insulation material is approximately 100~
2 Q O1gf/am' With Te, about 1/1 of concrete's elastic modulus 16X10~28XIOKgf/cm
500, and it can be considered that there is almost no constraint relaxation rate.

In addition, the temperature difference between indoors and outdoors increases with the improvement of insulation, and the difference in displacement FJ between the indoor and outdoor sides of the wall structure due to endothermic expansion and cooling contraction becomes smaller. The tensile stress acting on the finished surface increases.

As the tensile stress increases, the permissible range of tensile elastic strain and plastic strain that fluctuate following drying shrinkage becomes smaller.

When existing wet plastering material is injected into organic foam insulation material, it is presumed that one or more reasons are responsible for the frequent occurrence of cracks and peeling failures. In other words, gypsum plaster generally has an elastic modulus of 10XI0 to 17X l OKgf
/cm"t', its resistance shrinkage steepness is 2 x even a slight shrinkage like this can cause cracks when applied to the base of an organic foam insulation material. Also, cement mortar has an elasticity of 1 In addition to cracking, it may also peel off.

Compared to such existing interior wall coating materials, Wooden Civilization's E1/I1 composition exhibits expansibility through the mechanism described in +iii, so it is structurally mechanically capable of producing compressive stress on the coated surface. This will effectively prevent cracks. At the same time, since the cured gypsum composition of the present invention has a low elastic modulus and excellent bending and tensile strength, it is presumed that it follows displacement and is effective in preventing cracking. It is something that

Next, when a wet wall made of the gypsum composition of the present invention is compared with a dry wall made of the GL method, which is currently widely used, it has the following advantages.

The wet wall according to the present invention has structurally higher member strength and excellent impact resistance than dry wall. In addition, the sound insulation properties of a homogeneous wall are dominated by the mass,
There is a tendency for the sound insulation properties to increase as the areal density of the wall material increases, but the degree of the cured product V of the gypsum composition of the present invention varies slightly depending on the aggregate used, but is usually 1700 to 2.
740-9 of 1 gypsum board with a density of 000Kg/Otori
As is clear from the comparison with 80Kg/m', it always has excellent shielding properties. In addition, with the drywall of the GL method, there are inconveniences such as mold growth due to the use of ha-quality materials, and cracks in the painted surface of the 16-back board, which impairs the aesthetic appearance. The wet wall of the present invention has the advantage that it is solid, has excellent surface precision, and can provide a crack-free surface.

[Example] Examples of the present invention will be described below along with comparative examples.

First, Table 1 shows the composition formulations of various test products.

In order to investigate the physical properties of the cured products of these various compositions, we measured the compression 1 bending, tensile strength, static coefficient 1 flexural elastic modulus, and Ii ratio of change, and also measured the hydrated products. Electron W4 microscopic observation and powder X-ray diffraction were performed.

Table 2 shows the compression, bending, and tensile strength test results.
However, these tests are conducted in accordance with JIS R5201.
A X4X16cm specimen was prepared and Shimadzu Autograph 0
The measured values were obtained using an SS-2000 small capacity universal testing machine.

Table 3 shows the test results for the stability coefficient and bending elastic modulus. However, the stability coefficient is based on ASTM
A φ1010 x 20 cylindrical specimen was prepared according to C469 and measured using the strain gauge method. This was measured using a capacity test machine.

All specimens subjected to one or more tests were kept at a temperature of 20°C.
It was grown in an atmosphere with a humidity of 80% RH or higher.

In addition, Table 4 shows the test results for the length change rate of 1/1. However, the length change rate is based on JIS A 1129.
The measurements were carried out by curing a 4×4×16c hazy specimen in an atmosphere of humidity 20° C. and humidity 60% RH according to the comparator method.

Table 2 Table 3 Table 4 Next, the results of electron microscopic observation of the cured compositions listed in Table 1 are shown in Figures 1 to 7, and the powder X-ray diffraction results are shown in Figure 8. However, the samples used for these tests were made by mixing the paste with an appropriate amount of water at a temperature of 20°C and a humidity of 60% without using river sand from the formulation shown in the i@1 table.
It was obtained by curing in an RH atmosphere.

To briefly explain these test results, in the cured product of the composition of the present invention,
As can be seen in Figure 2 (100x electron micrograph of NO12), the presence of a void with a diameter of 0.1 μl after the peak is recognized. The formation of these voids is due to the surface activity of the resin as described above, and this is shown in Figure 3 (Composition N
This can be understood from the fact that no voids were observed in a comparative amount of the cured product to which no resin was added, as shown in the 100x electron micrograph of No. 008.

In addition, FIG. 4 (!IN composition No.
3500x electron micrograph of No. 1) and Figure 5 (No. 3 of No. 1)
500x electron micrograph), and in these hardened bodies, crystallized monolithic stone eaves are observed in the non-redundant amorphous stone f7.

Further, FIG. 6 shows a further enlarged view of the inside of the voids of the cured composition shown in FIGS. 2 and 3 (composition No. 1, 350
0x electron micrograph) and Fig. 7 (3500x electron micrograph of N092), in both of them, it is observed that needle-like crystals are generated everywhere within the voids. These needle-shaped crystals are ettringite [
CJA・3 CaS O4・32 H,Ol It imparts expandability to the cured product. Incidentally, the formation of such ettringite was observed in the powder x! This is also confirmed from the results of 11 diffraction.

As supported by the test results of the above examples, the gypsum composition of the present invention utilizes the surface activity of the resin to provide sufficient growth to ettringite, which is produced by the hydration reaction of gypsum and slag. By providing a space and imparting expandability to the cured product, and filling the space between the two stones and the slag hydrate with resin, the elastic modulus is lowered and bending and tensile properties are reduced.
It exhibits the property of improving surface strength.

Next, 7 is a wall constructed using the plaster composition of the invention and G
Regarding walls constructed using the L method, impact resistance and
g Sound insulation was compared and measured.

Table jS5 below shows the results of the impact resistance test.

However, this test was conducted on a concrete molded board coated with a 25cm thick foamed polystyrene board, the surface of which was finished with the gypsum composition of the present invention (compounds No. and I in Table 1 above), and on the GL construction method. 1.4K
x This is a measurement of the diameter and depth of the depression left on the surface when a steel ball is dropped from different heights.

In addition, FIG. 9 and FIG. 1O show test results with sound insulation properties controlled. No. 1 mixture) A was applied directly to the wall with a thickness of 15 mm, and
As shown in Fig. 12, for a wall finished by applying board adhesive C to a thickness of 13cm on a base of 1cm, and pasting gypsum boards B and B with a thickness of 1cm through the adhesive C, Each J
The sound pressure level difference was measured based on IS A 1417. By the way, @D-30, 0 in figures 9 and 10
-35 indicates the sound insulation class specified in JIS A 1419.1 For example, in schools and single-family residential buildings, [1-30 is applied to class 3, and D-35 is applied to class 2. .

As is clear from the above two test results, walls constructed using the gypsum composition of the present invention have structural characteristics that are superior in impact resistance and sound insulation compared to those finished using the GL construction method. It is confirmed that

L Effect of the Invention 1 As described above, the present invention can reliably prevent cracking and peeling when applied to the inner wall surface of an organic foam insulation material base such as foamed polyethylene/board using the wet method. Moreover, it has been possible to provide a gypsum composition suitable as a plastering material for this type of use, which can form an inner wall surface with excellent impact resistance, sound insulation properties, finished surface precision, and surface appearance.

[Brief explanation of drawings]

1 to 7 are electronic III microphotographs showing the crystal structure of the cured gypsum composition, and FIG. 1 is a photograph of the crystal structure of the composition of the present invention Not in Examples (magnification:
Figure 82 is a photograph of the crystal structure of 1q1102 (@
Figure 3 is a photograph of the crystal structure of comparative composition NO8 (magnification: 100x). Figures 4 and S are:
Figures 1 and 2 are enlarged views of the surface of the cured product other than the voids, and Figure 4 is an enlarged crystal structure photograph of Figure 1 (
Figures 6 and 7 are enlarged views of the inside of the voids in Figures 1 and 2, and Figure 6 is an enlarged crystal structure photograph of Figure 1 (magnification of 3500). FIG. 8 shows /Il! for each cured product with a material age of j2 for the various compositions shown in the Examples. It is a powder X-ray diffraction diagram obtained by Figure 9 shows the measurement results of the sound insulation properties of a wall constructed using the composition of the present invention. The first θ diagram is
M with a wall made of GL king law! It is a figure which shows the measurement result of carinity. FIG. 11 is a cross-sectional view showing the structure of an uninvented wall (@hole wall) that was subjected to a sound insulation measurement test;
FIG. 12 is a cross-sectional view showing the structure of a wall (panel-style wall) according to the GLl method.

Claims (1)

[Claims] Ethylene vinyl acetate resin and acrylic acid are added to a mixture consisting of 90 to 50 parts by weight of anhydrite containing a hardening accelerator and/or gypsum hemihydrate containing a retarder, and 10 to 50 parts by weight of blast furnace slag powder. A gypsum composition comprising 1 to 20 parts by weight, calculated as solid content, of one or more of an ester resin and a styrene-butadiene synthetic rubber.