JPS60158269A - Film-forming composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. capable of forming a non-defective thick coating film in a short time without being influenced by external conditions (temp., humidity, water permeability of substrate, etc.), by blending specified quantities of alumina cement and gypsum with an aq. dispersion of a high-molecular material. CONSTITUTION:10-200pts.wt. of the combined quantity of alumina cement (pref. one which is commercially available as cement for fireproof and corrosion-proof works) and gypsum (e.g. gypsum dihydrate) is added to 100pts.wt. aq. dispersion of a film-forming high-molecular material [e.g. rubber latex or a synthetic resin emulsion (solid concn : 30-75wt%)]. Alumina cement and gypsum are used in a weight ratio of 1:0.5-7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a polymer aqueous dispersion that can form a defect-free thick film in a relatively short period of time without being affected by external conditions such as temperature, humidity, and water permeability of the substrate. The present invention relates to a composition containing the following.

Conventionally, thick organic polymer films of several mats have been applied to architectural structures for the purpose of protection and waterproofing.
Materials such as heat-melting type and highly concentrated solution type are used. However, these materials have problems such as delicate mixing, the need to use fire, evaporation of solvents and odor, and above all, the disadvantage that it is difficult to apply to wet surfaces. . Water-based materials, especially water-based polymer dispersions, have been used for some time now, but because the vapor pressure of water at room temperature is lower than that of organic solvents, they are difficult to apply, such as overcoating, salt coagulation, and cement mixing. It is. In the case of multiple coatings, the efficiency decreases in the summer and in the winter due to a decrease in the rate of evaporation and a decrease in the rate of water use. Salt coagulation may reduce the ability to form a coating in winter, but
There are problems such as corrosion of reinforcing steel and other parts due to salt, damage caused by splashes caused by spraying, and curing to prevent this. Among the above coating film forming methods, the method with relatively few problems is the mixing of cement. When Bortland cement is used, it is said that about 40% of its own weight in water is taken away from the system through water hardening and adsorption. In addition, it generates polyvalent cations, and the surface area decreases approximately 1000 times during the curing process, resulting in a large surface free energy μ.
produce ghee. Dehydration and physicochemical actions destroy the colloidal state of the polymer water dispersion and promote thick film formation.

The disadvantages of potato cement include the above-mentioned temperature dependence of the water use reaction.

The strength of the water cured body is high, the elastic modulus of the coating film is extremely high, and it has the fatal defect of being prone to cracking. With Portland cement whose main component is μsium silicate, it is impossible to freely adjust the coating film formation rate and the flexibility of the coating film. Additionally, alumina cement alone has been used as a coating film formation accelerator. This case is advantageous in that the temperature dependence of the water utilization rate is relatively low and the water utilization cured product contains a large amount of crystallized water, that is, the dehydration power is strong. However, alumina cement has rapid setting properties, and even though it has the disadvantage of not being able to maintain the potstripe of the mixture especially in summer pigeons, it can be improved to some extent by adding a retarder, but it is not perfect. It's hard to say. Conventional formulations generally take advantage of the rapid hardening properties of alumina cement, and the elastic modulus of the coating film must be high.

The inventors of the present invention have conducted intensive studies on a coating film-forming composition that does not have the above-mentioned drawbacks, and have found that if alumina cement and Ceracola are used in combination and a specific amount of this is contained in a polymer aqueous dispersion, temperature, humidity, and substrate conditions can be improved. It was discovered that a composition capable of forming a defect-free thick film in a relatively short time can be obtained without being affected by external conditions such as water permeability, and based on this knowledge, the present invention was completed. I ended up doing it.

That is, the present invention contains Amu-mina cement, Setsukou, and a polymer water dispersion, and the ratio of alumina cement and Ceracola is about 0.5 to 7 parts by weight of Ceracola to 1 part by weight of alumina cement, and 1 part by weight of Ceracola. , the sum of alumina cement and Ceracola is about 10 to 100 parts by weight of the polymer water dispersion.
200 parts by weight of the film forming composition.

Examples of alumina cement used in the present invention include Ca0A1203. Ca0a2A1203-12C
The main component is force μsium μ laminate such as a0・7A1g03, some A1g03 is Fe2O3, and CaO is Mg.
It may be substituted with O, and commercially available ones for fireproofing and corrosion-proofing construction are preferred.

Ceracola used in the present invention includes, for example, anhydrous,
Either half-water or di-water may be used, but di-hydrate is preferred from the viewpoint of solubility, and chemical Ceracola is preferred from the viewpoint of purity.

The alumina cement and Ceracola described above are contained in a polymer water dispersion.

In that case, it is preferable that the ratio of alumina cement and Ceracola is about 0.5 to 7 parts by weight of Ceracola to 1 part by weight of alumina cement, and the sum of alumina cement and Ceracola is 100 parts by weight of the polymer water dispersion. About 10-2
00 parts by weight. If the ratio of Ceracola to 1 part by weight of alumina cement is less than 0.5 parts by weight, the coating film will become hard. If it exceeds 7 parts by weight, drying properties will not be sufficient.

If the sum of alumina cement and Ceracola is less than 10 parts by weight based on 100 parts by weight of the water polymer dispersion, drying properties will not be sufficient, and if it exceeds 200 parts by weight, the coating will become hard. Since alumina cement, Cera, and Kola are all in powder form, they may be mixed in advance, or they may be added separately to the polymer water dispersion.

The aqueous polymer dispersion used in the present invention may be of any type as long as it forms a film upon drying; for example, natural 9 synthetic rubber latex, synthetic resin emulsion, asphalt emulsion, etc. are suitable. be. These aqueous dispersions are required to have mixing stability with alumina cement and Ceracola, but the mixing stability is higher than that of, for example, polyoxyethylene aryl ether/l/l/ nonionic activators such as alkyl μ quaternary ammonium salts, alkyl μ phosphonium salts,
It can be obtained by adding a cationic activator such as an axophonium salt.

The solid content concentration of the aqueous polymer dispersion is preferably about 30 to 75% by weight, particularly about 40 to 65% by weight.

By mixing alumina cement, Ceracola, and a polymeric water dispersion, the film-forming composition of Shiki's invention is obtained.

It is preferable to mix alumina cement and Ceracola immediately before construction. During mixing, if necessary, to improve the fluidity of the composition, e.g.
, a water-soluble thickener such as a water-soluble 7 μlose compound, etc. may be added.

The coating film-forming composition of the present invention obtained in this manner is applied to a film thickness of several times the thickness for the purpose of protecting and waterproofing architectural structures. Defect-free thick films can be formed in a relatively short time without being affected by external conditions.

The present invention will be explained in more detail below using Examples.

Example 1 Anionic/nonionic styrene-butadiene rubber latex (OHX-02, manufactured by Takeda Pharmaceutical Company Ltd.).

Solid content: 50% by weight) and nonionic asphalt emulsion (Asso μA, manufactured by Nichirei Chemical Co., Ltd., solid content: 60% by weight) were mixed at a weight ratio of 30/100, and 100 parts by weight of this was mixed with alumina cement (A120342% by weight). Add 50 heavy bearing parts of the mixture with 2mII+
The results of thick casting are shown.

(Note) Curability is shown as dry to the touch after 24 hours of casting.

O...Drying complete Δ...Undried area remains inside ×...Large undried area The film elongation is based on the elongation of Amu Mina cement/Setsukou not added as 100. O...Elongation retention rate is 50% More than △...〃 10% or more and less than 50% ×-...? In formulations (41,2) containing only less than 10% alumina cement or with a large amount of alumina cement, the pot life of the mixture and the flexibility of the resulting film are poor.

On the other hand, it is clear that Todoroki 3 to 5, which are Examples of the present invention, are superior in two points: curability and film elongation.

Example 2 A mixture (hardening agent) of alumina cement/dihydric acid = 174 was added to 100 parts by weight of the same water dispersion as used in Example 1, and the same test as in Example 1 was conducted. Comparative example is J Engineering S Super Early Strength Cement Todoroki 1 10 1000 90
0 Δku △ 02 40 1300 1500 0
0 03 60 1650 1900 0 0 04
100 600 450 00 05 140 130
0 1300 00 △ comparison 2 40 3800 510
0 σ included △ △Example 3 60 Geumization during preparation --- (Note) Al~3. Comparative Examples 1-2 used a thickener, &5-
7 refilled water.

, curability, and film elongation are the same as in Example 1.

Example 3 Curing of 100 parts by weight of the same aqueous dispersion as in Example 1 with 50 parts by weight of a mixture of alumina cement/di-water-171 added and an O/W type high solids rubber asphalt waterproofing material. A gender comparison was made.

(Note) Curing property of 2111111 is 24HR after casting.
, 5 mm shows the results after 48 HR. The curability display is the same as in Example 1.

In the comparative example, curing inside the film was slow. In contrast, it is clear that the composition of the present invention has excellent curability at 20°C and 5°C.

Example 4 Alumina cement (
40 parts by weight of a mixture of 80.0 wt. As a comparative example, J Engineering S Super Early Strength SE (Note) film elongation of 0 shows almost the same elongation as Amu Mina cement/no gypsum additive. Other positive indications are the same as in Example 1.

Claims (1)

[Claims] It contains alumina cement, Ceracola and a polymer water dispersion, the ratio of alumina cement and Ceracola is about 0.5 to 7 parts by weight per 1 part by weight of alumina cement, and the sum of alumina cement and Ceracola is The coating film-forming composition is about 10 to 200 parts by weight based on 100 parts by weight of the aqueous polymer dispersion.