JPH0292965A - Production of inorganic paint - Google Patents

Abstract

PURPOSE:To obtain an inorganic paint having good storage stability and giving a coating film having excellent adhesivity, hardness, water-resistance, etc., by using a water-soluble silicate and phosphoric acid (salt), etc., as binders and mixing a hardener component, etc., to the binders before use. CONSTITUTION:The objective inorganic paint can be produced in the form of an aqueous dispersion by mixing (A) an aqueous binder containing a water-soluble silicate and/or phosphate with (B) a curing agent reactive with the component A to cure the component (e.g., metal oxide such as ZnO or MgO or aluminum hydrogen phosphate) immediately before use.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing an inorganic paint.

More specifically, the present invention relates to an improved method for producing a two-component hot water-soluble inorganic paint, in which a water-soluble silicate and phosphoric acid or a phosphate are used as a binder and mixed with a curing component etc. before use. It is something.

[Conventional technology]

Inorganic paints have high hardness and are hard to scratch, and because they have inorganic bonds, they have excellent chemical resistance, high chemical resistance, light resistance, and weather resistance, and are resistant to mold growth.
It also has many excellent properties such as high heat resistance and nonflammability. For this reason, it is used in many fields, such as coating the exterior walls of buildings and the interior of tunnels, and painting chemical experiment table tops and toilet units.

There are various formulations of these inorganic paints, but those mainly used include water-soluble silicate, phosphoric acid, or phosphate as a binder, and a hardener, pigment, filler, dispersant, etc. It is a combination of. Examples of these include Japanese Patent Publication No. 435806, No. 44-23436, No. 47-6030, No. 49-47249, No. 53
There is one disclosed in No.-19612.

[Problem to be solved by the invention]

The previously used inorganic paints using water-soluble silicate binders, phosphoric acid, or phosphate binders are those in which the binder component is hardened with a curing agent, so chemical curing such as curing occurs during storage of the paint. Care must be taken to prevent changes from occurring.

One possible method is to increase the degree of inertness by increasing the firing temperature of the curing agent component, but this is not preferable because it requires a higher firing temperature.

Another method is to supply and mix the curing agent component in powder form, but in this case, the curing agent component is not well dispersed, the properties of the coating film are deteriorated, and the surface smoothness is also poor.

In addition, it is possible that the blended paint may be consumed before it deteriorates, but it is not realistic to blend and consume it in a planned manner for a wide variety of grades and uses.

As a more general solution, there is a method of preparing a two-component paint in which the binder component and the curing agent component are separated, and blending both in predetermined amounts immediately before use.

However, with this method, the work is complicated, and there are concerns about poor performance due to measurement errors and poor mixing.
Work management to overcome this problem is also troublesome. Furthermore, if both of these components, especially the curing agent component, are dispersed in water and stored for a long period of time, the curing agent component will react with water, undergo hydrolysis, and cause deterioration. If the liquids are mixed during painting, problems such as gelation of the binder may occur.

Therefore, the present invention has no restrictions on pot life after manufacturing.
The present invention provides a water-based inorganic paint. The present invention also provides a method for producing an aqueous inorganic paint that eliminates the need for mixing two liquids in a paint factory, is easy to manage, and can be stored for a long time.

[Means to solve the problem]

The present invention provides: a) an aqueous binder containing one or more components selected from the group consisting of water-soluble silicates, phosphoric acid, and phosphates, and b) curing by reacting with the aqueous binder. an aqueous dispersion containing a curing agent, and at least the aqueous dispersion containing the curing component b) is stored in a frozen state, and immediately before use, the aqueous dispersion containing the curing component is , a method for producing an aqueous inorganic paint, characterized in that it is mixed with the aqueous binder of a).

Furthermore, in the present invention, each of the aqueous binder a) and the aqueous dispersion containing the curing agent b) constitutes frozen fine particles, and these are blended in accordance with the required amount at the time of use. The present invention also provides a method for producing a water-based inorganic paint characterized by the following characteristics.

The water-soluble binder used in the paint of the present invention may be any binder that is water-soluble and, when mixed with a curing agent, cures at room temperature or by heating to form the desired coating film. Those mainly consisting of water-soluble silicates and/or water-soluble phosphates are preferred, such as alkali metal silicates such as sodium silicate, potassium silicate, and lithium silicate, ammonium silicate, acidic aluminum phosphate, acidic zinc phosphate, etc. is used.

These are used as aqueous solutions, and the concentration thereof is usually 20 to 60% by weight, preferably 30 to 50% by weight.

The curing agent components used in the paint of the present invention are Z no, M
Heat-treated condensates of metal oxides or phosphates such as gO and CaO, such as phosphates such as acid aluminum phosphate, acid zinc phosphate, and acid phosphate steel, singly or in combination, are heat-treated at high temperatures. The condensed phosphate obtained by It is also possible to use a composite produced by heat-treating an acidic phosphate and a silicate. If these heat treatments are performed excessively, the reactivity with the binder will disappear, but
The degree can be appropriately selected in consideration of the curing conditions required for the paint.

The paint of the present invention may contain pigments, fillers, dispersants, etc. in addition to the above components. These components may be blended together with a binder or a curing agent component.

In producing the paint of the present invention, a) a binder component and b) a curing agent component are prepared in the same manner as in the production of ordinary inorganic paints. That is, each component is dissolved in a predetermined amount of water, or these are placed in a ball mill, sand mill, etc. and pulverized and mixed for a required period of time to produce a solution, dispersion, or paste of a predetermined concentration.

Each component a), b) thus prepared is frozen separately. Freezing can be done by any method as long as each component can be cooled to a predetermined temperature, frozen, and ground into separate particles. For example, each component can be simply frozen in a freezer, then Alternatively, it may be pulverized using a hammer mill, but care must be taken in this case since the distribution of each component may become uneven during the freezing period. Spray freezing is adopted as a method to solve this problem. That is, the method involves spraying each component into a low-temperature space and instantly freezing the mist. According to this spray freezing method, unevenness and non-uniformity of the components can be prevented, and a uniform and fine powder can be obtained without providing a separate pulverization step. If the spray output and mist mixing are perfectly controlled, a)
b) Mixing the components can also be done automatically.

Furthermore, among the components of the two-component thermal paint that is the object of the present invention,
The curing agent component (b) is particularly susceptible to changes over time, so only this component (b) is frozen and stored, thawed at the time of use, and mixed with the binder component (a) at a predetermined ratio.
It may be used after stirring.

The freezing and storage temperature naturally varies depending on the type and concentration of the dissolved components, but the point is that the temperature is freezing, that is, crystallizing, and that the components do not react with each other or with water, preferably - It is in the range of 5 to -20°C. At temperatures higher than this, local melting may occur depending on the temperature distribution of the storage, and at temperatures below -20°C, although it is good in terms of lower activity, the equipment becomes expensive and maintenance costs are high. This is not desirable as it also increases the size.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 (Preparation of binder component a)) Sodium silicate solution (JIS No. 14083, 40%) 50 parts by weight Potassium silicate aqueous solution (K, 09%, Si0□20%) 50 parts by weight After thoroughly mixing with a stirrer, the mixture was frozen at -5°C.

This frozen product was pulverized as it was in a mill to reduce it to 3 meshes or less.

(Preparation of curing agent component b)) Mix 50 parts by weight of acidic aluminum phosphate and 50 parts by weight of acidic zinc phosphate, and heat at 400°C for 5 hours at 600°C.
The fired product was pulverized to a particle size of 180 mesh or less. 28 parts by weight of the hardening agent thus obtained, the pigment (
cr203 > 12 parts by weight, 8.5 parts by weight of silica sand powder, 1.5 parts by weight of dispersant and 50 parts by weight of water were charged into a ball mill, pulverized and mixed to prepare an aqueous dispersion. This was frozen at -5°C and ground into 3 meshes or less while frozen.

(Preparation of mixed components) Each frozen powder component a) and b obtained as above
), 100 parts by weight of each were mixed, and the mixture was heated to -5°C.
The samples were stored in a freezer for a specified period of time and used for testing.

(Painting test) The above frozen powder mixture was melted at 10°C, stirred, and applied to a slate board with air spray at 200 g/x2.
It was fired at 00°C for 30 minutes to obtain test pieces for various evaluations.

The evaluation results are shown in Table 1.

Example 2 (Preparation of binder component a)) 80 parts by weight of a potassium silicate aqueous solution (K 209%, S io 220%) and 20 parts by weight of an ammonium silicate aqueous solution (NH, 13%, 5io2 45%) were thoroughly mixed with a stirrer. Thereafter, it was sprayed into a room cooled to -10°C and frozen. This frozen product was a fairly uniform spherical body, and the size was about 60 mesh.

(Preparation of curing agent component b)) 20 parts by weight of zinc oxide, 10 parts by weight of kaolin clay, 12 parts by weight of pigment (Cr20-), 8.5 parts by weight of silica sand powder, 1.5 parts by weight of dispersant, and 50 parts by weight of water. were placed in a ball mill, ground and mixed to prepare an aqueous dispersion. This-
It was sprayed into a room cooled to 10°C and frozen. This frozen material was a fairly uniform spherical body, and the size was about 100 mesh.

(Preparation of mixed components) Each frozen powder component a) and b obtained as above
), 100 parts by weight of each were mixed, and heated to -5°C.
It was stored in a freezer and used for testing.

(Painting test) The above frozen powder mixture was melted at 20°C, stirred, and applied to a slate board with an air spray in an amount of 200 gems.
It was fired at 00°C for 30 minutes to obtain test pieces for various evaluations.

The evaluation results are shown in Table 1.

Example 3 (Preparation of binder component a)) The mixed solution prepared in Example 2 was stored in liquid form at 20° C. without freezing.

(Preparation of curing agent component b)) 80 parts by weight of acidic zinc phosphate and 20 parts by weight of acidic magnesium phosphate were mixed and baked at 450°C for 3 hours, at 600°C for 8 hours, and further at 900°C for 18 hours. This fired product was pulverized to a particle size of 180 mesh or less. 25 parts by weight of the curing agent thus obtained, pigment (Cr2
02) 12 parts by weight of kaolin clay, 5 parts by weight of kaolin clay, 3.5 parts by weight of silica sand powder, 1.5 parts by weight of dispersant and 50 parts by weight of water were charged into a ball mill, and pulverized and mixed to prepare an aqueous dispersion. . This was sprayed into a room cooled to -20°C and frozen. This frozen material was a fairly uniform spherical body, and the size was about 100 mesh.

This was stored in a frozen state.

(Coating test) 100 parts by weight of the above frozen powder component b) was melted, mixed with 100 parts by weight of binder component a), stirred, applied to a slate board with air spray to 200 gems, and heated to 300°C.
The sample was baked for 30 minutes and used as a test piece for various evaluations.

The evaluation results are shown in Table 1.

Example 4 (Preparation of binder component a)) 70 parts by weight of acidic aluminum phosphate aqueous solution (A120333.0%, 'P20, 8.5%) Stir 30 parts by weight of acidic zinc phosphate aqueous solution (ZnO 16%, P2O 528%) After thoroughly mixing in a machine, the mixture was sprayed into a room cooled to -20°C and frozen. This frozen product was a fairly uniform spherical body, and the size was about 60 mesh.

(Preparation of hardening agent component b)) 40 parts by weight of zinc oxide, 40 parts by weight of magnesium oxide and 20 parts by weight of kaolin clay were mixed and fired at 800°C for 8 hours. This fired product was pulverized to a particle size of 180 mesh or less. Curing agent 30 thus obtained
Parts by weight, 15 parts by weight of pigment (T io 2), 5 parts by weight of silica sand powder, and 50 parts by weight of water were placed in a ball mill, pulverized, and mixed to prepare an aqueous dispersion. This was sprayed into a room cooled to -20°C and frozen. This frozen material is
It was a uniform spherical body, and the size was about 100 meshes.

(Preparation of mixed components) Each frozen powder component a) and b obtained as above
), 100 parts by weight of each were mixed, and the mixture was heated to -5°C.
It was stored in a freezer and used for testing.

(Painting test) The above frozen powder mixture was melted at 10°C, stirred, and applied to a slate board at 200 g/x" with air spray.
It was fired at 00°C for 30 minutes to obtain test pieces for various evaluations.

The evaluation results are shown in Table 1.

Comparative Example 1 A test was conducted in the same manner as in Example 1, except that a) the binder component and b) the curing agent component were stored at 30° C. without being frozen. The results are shown in Table 1.

Comparative Example 2 b) The test was conducted in the same manner as in Example 3, except that the curing agent component was not frozen and stored at 30°C.

The results are shown in Table 1.

Comparative Example 3 b) The test was conducted in the same manner as in Example 4, except that the curing agent component was not frozen and stored at 30°C.

The results are shown in Table 1.

Comparative Example 4 Component b) in Example 1 was dry ground to 400 mesh or less. 50 parts by weight of this (same as Example 1 a)
Mixing with 100 parts by weight of the binder component without freezing,
Stir and test. The test methods for each performance of the coating film shown in Results Table 1 are as follows.

1) Appearance: Based on visual observation.

2) Adhesion: Measured according to the JIS 5400 cross-cut test method.

3) Hardness: Mohs hardness.

4> Water resistance: After immersing in tap water at room temperature for 30 days,
The appearance was visually observed.

5) Moisture resistance: 7 in an atmosphere of 50℃ and 100% relative humidity.
After standing for a day, the appearance was visually observed.

6) Stain resistance: The surface was stained with oil-based marker ink, and after 24 hours, synthetic detergent was applied and washed with water, and the state of surface staining was visually observed.

7) In the above visual observation, O indicates "good", Δ indicates "slightly poor", and x indicates "r poor".

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to produce a paint that does not change in quality even after long-term storage and that provides excellent coating performance by simply performing melting and stirring operations during use.

Claims (2)

[Claims] (1) a) an aqueous binder containing one or more components selected from the group consisting of water-soluble silicates, phosphoric acid, and phosphates; and b) curing by reacting with the aqueous binder. An aqueous dispersion containing a curing agent; In a method for producing an inorganic coating material consisting essentially of the following, the aqueous dispersion containing the curing component of b) is stored in a frozen state, and immediately before use, the aqueous dispersion containing the curing component is ) A method for producing an inorganic paint, characterized in that it is mixed with an aqueous binder. (2) Each of the aqueous binder in a) and the aqueous dispersion containing the curing agent in b) constitutes frozen fine particles, and these are blended according to the required amount at the time of use. A method for producing an inorganic paint according to claim 1.