JPH03170357A - Inorganic coating composition - Google Patents

Abstract

PURPOSE:To produce an inorganic coating composition capable of providing cured products excellent in weather and abrasion resistance after curing by blending an alkali metal silicate with aluminum condensed phosphate and calcium silicate in a specific proportion. CONSTITUTION:An inorganic coating composition containing (A) an alkali metal silicate, (B) aluminum condensed phosphate and (C) calcium silicate at (100/10)-(100/30) weight ratio of the components {(A)/[(B)+(C)]} and (20/80)-(80/20) weight ratio of the components (B)/(C) is prepared. Sodium silicate, potassium silicate, etc., are cited as the component (A) and the component (B) is prepared by adding aluminum hydroxide to phosphoric acid so as to provide about 1.1-3 molar ratio of P2O5/Al2O3. Calcium metasilicate, calcium orthosilicate, etc., are cited as the component (C). Thereby, a composition capable of providing cured products excellent in weather and abrasion resistance can be prepared and suitably used for coating inorganic building materials, etc.

Description

Detailed Description of the Invention <Industrial Field of Application> The present invention relates to a composition for inorganic coatings, and in particular to a composition for inorganic coatings that can be cured to obtain a cured product with excellent weather resistance and abrasion resistance. relating to things.

<Prior art> In recent years, water-soluble silicates have been used as heat-resistant inorganic coating materials and adhesives, and various metals, metal oxides, metal hydroxides, metal salts, silicides, and silica fluoride have been used as hardening agents. Inorganic compositions containing compounds, phosphate compounds, borates, organic compounds, etc. are known.

However, these conventional inorganic compositions are heat resistant, nonflammable,
Although it has excellent chemical resistance, it is inferior in terms of moisture resistance, water resistance, weather resistance, impact resistance, abrasion resistance, etc.

Therefore, a composition containing condensed aluminum phosphate, which has been calcined at a high temperature of 750° C., has been proposed as a hardening agent. (Unexamined Japanese Patent Publication No. 5836961) Problems to be Solved by the Invention> However, the composition containing the baked-in condensed aluminum phosphate is still insufficient in terms of weather resistance and abrasion resistance. In particular, it has been difficult to apply it as an exterior wall material for buildings exposed to harsh outdoor environments, or as a covering material for gutter gratings, street tree gratings, etc.

Therefore, an object of the present invention is to obtain a cured product having excellent properties as an inorganic composition in terms of heat resistance, nonflammability, chemical resistance, etc., and particularly excellent weather resistance and abrasion resistance. The purpose of the present invention is to provide a composition for inorganic coating that can be used as an inorganic coating material.

Means for Solving the Problems> In order to solve the problems, the present invention includes (A) an alkali metal silicate, (B) condensed aluminum phosphate, and (C) calcium silicate, and (A)/( The weight ratio of (B) + (C)) is 100/10 to 100/30, and (B
)/(C) weight ratio of 20/80 to 80/20.

Examples of the alkali metal salt that is component (A) of the composition of the present invention include sodium silicate, potassium silicate, lithium silicate, and the like.

Among these, potassium silicate is preferred since it provides a cured product with excellent efflorescence resistance. These are 1f! They can be used alone or in combination of two or more.

The condensed aluminum phosphate, which is the component (B) of the composition of the present invention, combines aluminum hydroxide with P205/A
A solution obtained by adding phosphoric acid to J2 2 0 s in a molar ratio of 1.1 to 3 is evaporated and concentrated to obtain acidic aluminum orthophosphate, and this acidic aluminum orthophosphate is subjected to heat treatment, e.g. , Japanese Patent Publication No. 52-138500
Loss on ignition at 400-600℃ as described in No. 05~
Examples include those obtained by heat treatment until the amount becomes 1%.

Calcium silicate, component (C) of the composition of the present invention, is
It is a compound of calcium oxide and silicon dioxide, and there are various types depending on the ratio of the two, such as calcium metasilicate and alsium orthosilicate, preferably calcium orthosilicate (commonly known as dicalcium silicate).

In the composition of the present invention, the above (A)/(B)+ (
The weight ratio of C) is adjusted to 1'OO/10 to 100/30, preferably 100/15 to 100/20. (
If the weight ratio of A)/(B)+(C) is less than 100/10, the resulting composition will not have sufficient curability and will not exhibit sufficient water resistance and abrasion resistance even after curing. , also 1
If it exceeds 0.0/30, the curing reaction of the resulting composition will be too rapid, and a sufficient pot life will not be obtained.

In addition, the weight ratio of CB)/(C) is 20/80 to 80/
20, preferably 40/60 to 60/40. If the weight ratio of (B)/(C) is out of this range,
Even when the resulting composition is cured, sufficient weather resistance cannot be obtained,
For example, if the ratio is less than 20/80, the cured product will not show sufficient weather resistance in a weather resistance test using a weatherometer;
If it exceeds 0/20, the cured product will not exhibit sufficient weather resistance in the salt spray test.

The composition of the present invention includes the above (A), (B) and (C).
In addition to the above ingredients, pigments, finely powdered coloring substances, aggregates, fillers, etc. may also be optionally included.

The method for producing the composition of the present invention is not particularly limited, and any method may be used. For example, the above-mentioned components (A), (B), and (C), and other ingredients as necessary, are mixed using a commonly used mixing device such as a ball mill, roll mill, mixer, or mortar mixer. be able to.

The composite material of the present invention obtained as described above can be applied to a wide range of applications such as exterior and interior constructions, gratings for gutters, and gratings for roadside trees. For example, as a coating material for metal, calcium silicate board, plaster board, mortar, concrete, and other inorganic building materials.
It can also be applied as an inorganic adhesive.

The composition of the present invention can be coated onto various members by adjusting the viscosity appropriately and coating the surfaces of the members. The coating method is not particularly limited, and may be any method such as brush coating, air spray coating, airless spray coating, spatula coating, and roller coating.

Examples> Hereinafter, the present invention will be explained in more detail by giving examples and comparative examples of the present invention. In addition, in the following examples, "parts" represent "parts by weight."

(Example 1) Potassium silicate (mole ratio of Si02/K20 = 3.5) 1
00 parts by weight, 3 parts of condensed aluminum phosphate (manufactured by Hoechst Gosei Co., Ltd., HB Hardener), silicate lime 2CaO・Sin
210 parts, 40 parts of black pigment (chromium oxide composite pigment, manufactured by Nippon Fellow Co., Ltd., 1335P), 10 parts of Aerosil, and 70 parts of water were mixed in a ball mill for 1 hour to produce a composite.

After lightly polishing the surface of the obtained composition with sandpaper, a degreased iron plate (dimensions: 50X100X0
．． 8 mm) to form a coating film with a coating thickness of approximately 50 μm. Next, dry at 200°C in a hot air circulation dryer.
The coating film was cured by baking for 30 minutes. The obtained cured coating film was tested for water resistance, weather resistance, and
Effresence resistance and abrasion resistance were measured, and the coatings were also subjected to a salt spray test. The results are shown in Table 1.

Water Resistance After being immersed in water at 20° C. for 500 hours, the condition of the cured coating was observed.

Weather resistance The test was conducted in accordance with the accelerated weather test specified in JIS K5400.

■Salt spray test It was conducted in accordance with JIS K5400.

■ Efflorescence resistance A polyethylene rectangular parallelepiped container with an internal volume of 1 OOx is filled with water to a depth of 5 cm, and the air inside is removed by CO2.
2 to create a CO2 atmosphere, an iron plate was placed in a container, and the state of the cured Li film was observed after being left at 20° C. for 240,000 yen.

(Example 2) Potassium silicate (Si02/K20 molar ratio: 3.5)
100 parts, 6 parts of condensed aluminum phosphate, 1 part of dicalcium silicate
A composition was prepared by mixing 5 parts of titanium white, 40 parts of titanium white, 10 parts of Aerosil, and 70 parts of water in a ball mill for 1 hour.

Using the obtained composition, a cured coating sample was prepared in the same manner as in Example 1, except that the baking and curing treatments were performed at 150°C for 1 hour, and the samples were evaluated for water resistance, weather resistance, and efflorescence resistance. The hardness and abrasion resistance were measured, and the material was also subjected to a salt spray test. The results are shown in Table 1.

(Example 3) Potassium silicate (molar ratio of SiO2/K20 = 35)
A composition was prepared by mixing 100 parts of condensed aluminum phosphate, 10 parts of dicalcium silicate, 30 parts of colloidal silica (Ludox AM), 30 parts of black pigment, and 50 parts of water in a ball mill for 1 hour.

Using the obtained composition, a cured coating sample was prepared in the same manner as in Example 1, and the sample was measured for water resistance, weather resistance, efflorescence resistance, and abrasion resistance, and was also subjected to a salt spray test. provided. The results are shown in Table 1.

(Comparative Example 1) A composition was produced in the same manner as in Example 1 except that the amount of condensed aluminum phosphate used was changed to 16 parts and dicalcium silicate was not used. A membrane sample was prepared, and its water resistance, weather resistance, efflorescence resistance, and abrasion resistance were measured, and it was also subjected to a salt spray test. The results are shown in Table 1.

Effects of the Invention The inorganic coating composition of the present invention has excellent properties as an inorganic composition in terms of heat resistance, nonflammability, chemical resistance, etc., and is a cured product that has particularly excellent weather resistance and abrasion resistance. can be obtained.

The resulting cured product is completely nonflammable, hard like ceramic, and has a beautiful luster. This composition has excellent adhesion to calcium silicate boards, plaster boards, mortar, concrete, and other inorganic building materials, and can suitably coat these materials. It can also be used as an adhesive, and is suitable for industrial applications. The utility value is a dog.

In particular, it is suitable for building exterior wall materials that are constantly exposed to the outdoors, and for coating materials for gutter gratings and roadside tree gratings that also require wear resistance.

1 2

Claims (1)

[Claims] Contains (A) an alkali metal silicate, (B) condensed aluminum phosphate, and (C) calcium silicate, and the weight ratio of (A)/((B)+(C)) is 100.
/10 to 100/30, and the weight ratio of (B)/(C) is 20/80 to 80/20.