JP5734642B2 - Method for producing inorganic coating composition - Google Patents

Description

The present invention relates to an inorganic coating composition suitably used as an interior / exterior coating in the field of construction / civil engineering.

Conventionally, as a coating resin in an organic paint used for interior and exterior for construction and civil engineering, synthetic resins such as acrylic resin, urethane resin, and fluororesin are often used. Coatings using these synthetic resins have the advantage that they can form a coating film at a low temperature near room temperature and in a short time, and are excellent in adhesion, impact resistance, water resistance and the like of the coating film. However, organic paints, on the other hand, have low heat resistance, low coating film hardness, low weather resistance, etc., so that coating of hot pipes around engines such as vehicles and nonflammability are required for buildings. It is not suitable for applications such as interior material coating, painting of tunnel inner walls that require high heat resistance and wear resistance.

Therefore, in recent years, various studies have been made on inorganic paints that are basically heat-resistant, wear-resistant, and highly durable without using organic synthetic resins for paints, and some are being put into practical use. .

As inorganic paint binders, those mainly composed of an aqueous alkali silicate solution represented by water glass are well known. However, in the case of alkali silicate, the room temperature curing required from the viewpoint of workability such as tunnel inner walls and building outer walls is a major bottleneck due to insufficient water resistance and adhesion to the substrate. It has not been fully put into practical use.

So far, inorganic paints using inorganic paint binders have been required to be sintered at a high temperature of 200 ° C or higher in order to form a dense coating, and are used only for very limited applications. (For example, refer to Patent Document 1).

In order to solve these problems, a coating material in which a metal alkoxide is used as an inorganic coating binder and an inorganic filler and an organic emulsion are contained therein has been developed (for example, see Patent Document 2). However, the durability of the coating film is inferior to that of the above-mentioned inorganic paint, and the results are not satisfactory in terms of hardness and impact resistance.

JP-A-6-329949 JP 2000-334373 A

An object of the present invention is to form a coating film by curing at room temperature without any heating in an inorganic coating material using an inorganic coating binder, and the obtained coating film is cured at room temperature. Regardless, it is to provide an inorganic coating composition having high water resistance and good adhesion to a substrate.

The present invention, a flat main agent comprising a particulate silica and water Hitoshitsubu diameter of 1.0μm or less, flat Hitoshitsubu径1.0μm or less calcium compound, comprising a dispersant and water hardeners Is a method for producing an inorganic coating composition produced by mixing and the fine particle silica and the calcium compound are applied with a high pressure of 50 to 400 MPa to the slurry, the slurry is branched into two flow paths, and merges again. It is manufactured using a pulverizer that uses high-pressure water that is crushed by opposing collisions at the part, and the dispersant is a sulfonated melamine-based, naphthalenesulfonic acid-based, polycarboxylic acid-based, or polyether-based It is a manufacturing method of the inorganic type coating composition which is 1 type, or 2 or more types selected from the group which consists of this inorganic type coating composition whose calcium compound is calcium hydroxide The amount of the dispersant used in the curing agent is 1 to 30 parts (in terms of solid content) with respect to 100 parts of the calcium compound, and further the styrene acrylic. It is one or more selected from the group consisting of a copolymer, an acrylic copolymer, an epoxy resin, an ethylene-vinyl alcohol copolymer, an ethylene-acrylic acid copolymer, and an ethylene-acrylic acid ester copolymer. This is a method for producing an inorganic coating composition containing 0.1 to 10 parts or less of a polymer dispersion with respect to 100 parts of fine particle silica , and further a curing time adjusting agent is added to 0 part of 100 parts of calcium compound. coating method der of the inorganic-based coating composition containing .1～30 parts is, a slurry in which fine particles of silica are dispersed metallic silicon powder injected into the flame combustion Fine particle silica produced by a method of oxidation, the concentration of fine particle silica in the main agent is 10 to 80%, the amount of calcium compound used is 20 to 200 parts with respect to 100 parts of fine particle silica, and the curing agent The concentration of the calcium compound therein is 5 to 60%, the mixing ratio of the main agent and the curing agent is 5: 1 to 1: 5, the dispersant is naphthalene sulfonic acid, and further the dispersant is used as the main agent. This is a method for producing an inorganic coating composition used in an amount of 1 to 30 parts (in terms of solid content) with respect to 100 parts of fine-particle silica, and further contains a polymer dispersion which is an ethylene-vinyl alcohol copolymer as a main ingredient, and sulfuric acid. It is a manufacturing method of this inorganic type coating composition which contains the hardening time regulator which is sodium in a hardening | curing agent .

By using the inorganic coating composition of the present invention, it is possible to form an inorganic coating film that is cured at room temperature, has excellent water resistance, and has good adhesion to a substrate.

Unless otherwise indicated, parts and% described in the present invention mean parts by mass and% by mass.

Hereinafter, embodiments of the present invention will be specifically described.

The particulate silica of the present invention is a method of collecting fumes generated from an electric furnace in the process of producing metal silicon or zirconia (silica fume), for example, a slurry in which metal silicon powder is dispersed is injected into a flame and burned. The fine particle silica powder produced by the oxidation method is preferable in that it has less aggregation (structure) and high reactivity with the curing agent.

The fine particle silica of the present invention, for example, injects metal silicon or siliceous raw material powder into a high-temperature flame formed by a combustible gas and an auxiliary combustion gas to form a molten spheroid, and collects the spherical silica powder while cooling. Furthermore, fine particle spherical silica powder having an average particle diameter excellent in fluidity promoting effect can be collected by the classification treatment. For example, it can manufacture by the method of patent document 5 or patent document 6.

JP 2001-335313 A Japanese Patent Laid-Open No. 2002-2011

Examples of the fine particle silica include trade names “SFP-20M” and “SFP-30M” manufactured by Denki Kagaku Kogyo Co., Ltd., and trade names “Admafine” manufactured by Admatech.

The particle size of the fine particle silica of the present invention is not particularly limited as long as a desired effect is obtained, but an average particle size of 1.0 μm or less is preferable because it has excellent permeability and adhesion to mortar and concrete. 0.8 μm is more preferable.

Examples of the calcium compound of the present invention include inorganic substances such as calcium hydroxide, calcium chloride and gypsum, and calcium salts of organic acids such as calcium formate. Of these, calcium hydroxide is preferred because of its high reactivity with the main agent.

When the calcium compound is hardly soluble or insoluble alone, it is preferable to grind to an average particle size of 1.0 μm or less because of its excellent permeability and adhesion to mortar and concrete. It is more preferable to grind to 1.0 μm. Alternatively, when the calcium compound is calcium hydroxide, the soluble calcium salt such as calcium chloride and the soluble alkali salt such as sodium hydroxide and potassium hydroxide are dissolved and mixed, respectively. Calcium hydroxide can be produced.

In the present invention, fine particle silica and a calcium compound are each dispersed in water to produce a main agent and a curing agent, respectively.

The concentration of fine particle silica in the main agent of the present invention is preferably 80% or less, more preferably 10 to 70%, and most preferably 20 to 60%. When the concentration of fine particle silica exceeds 80%, the viscosity becomes high and workability may be poor. In the present invention, it is also possible to produce a high-concentration fine particle silica slurry in advance and dilute it with water during construction.

The amount of calcium compound used in the curing agent of the present invention is preferably from 20 to 200 parts, more preferably from 50 to 100 parts, based on 100 parts of fine particle silica. When the amount of the calcium compound is less than 20 parts or more than 200 parts, the reactivity with the main agent may be small. In the present invention, it is also possible to produce a calcium compound slurry having a high concentration in advance and dilute it with water at the time of construction.

The concentration of the calcium compound in the curing agent of the present invention is preferably 60% or less, more preferably 5 to 50%, and most preferably 10 to 40%. When the concentration of the calcium compound exceeds 60%, the viscosity becomes high and workability may be poor. In the present invention, it is also possible to produce a calcium compound slurry having a high concentration in advance and dilute it with water at the time of construction.

In the present invention, a dispersant is used in combination with the curing agent. In the present invention, a dispersant is used in combination with the main agent. When a dispersant is added only to the curing agent, the composition reacts at the moment of mixing with the main agent liquid, and the viscosity can be rapidly increased. Moreover, when a dispersing agent is used in combination with the main agent and the curing agent, an abrupt increase in viscosity can be prevented and permeability to mortar and concrete can be secured. Therefore, it is possible to secure an arbitrary working time by changing the amount of the main agent and the dispersant for the curing agent.

The dispersant used in the present invention is preferably a so-called high-performance dispersant such as a sulfonated melamine-based, naphthalenesulfonic acid-based, polycarboxylic acid-based, or polyether-based one, or two or more of these. Used as a mixture.

The amount of the main agent dispersant used is preferably 30 parts (in terms of solid content, the same shall apply hereinafter) or less, more preferably 1 to 10 parts, per 100 parts of the fine particle silica of the main agent. If it exceeds 30 parts, the curing time may be long.

As for the usage-amount of the dispersing agent of a hardening | curing agent, 1-30 parts are preferable and, as for the addition amount of a dispersing agent with respect to 100 parts of calcium compounds, 5-20 parts are more preferable. If the amount is less than 1 part, the reaction solidifies at the moment of mixing with the main agent, and the working time may not be ensured. If the amount exceeds 30 parts, the curing time may become long. In order to increase the permeability to mortar and concrete, the fine particle silica and the calcium compound are preferably dispersed or pulverized by various wet pulverizers. The average particle size referred to here is an ultrasonic wave obtained by using a laser diffraction particle size distribution analyzer (for example, “LA-920 type” manufactured by HORIBA, Ltd.) as a normal pretreatment for a suspension that has been wet-dispersed. It is a value measured in a water medium without performing a dispersion treatment. When the average particle diameter of the fine particle silica and calcium compound measured without performing ultrasonic dispersion treatment is 1.0 μm or less, the fine particle silica hardly aggregates. Therefore, the permeability to mortar and concrete can be increased. The suspension subjected to wet dispersion treatment refers to, for example, a main agent obtained by wet dispersion treatment of fine particle silica and a curing agent obtained by wet dispersion treatment of calcium hydroxide.

The wet pulverizer used in the present invention may be a method using any of an ultrasonic device, a high-speed stirrer, a medium stirring mill, a pulverizer using high-pressure water, etc., and is selected alone or in combination. Of these wet pulverizers, a pulverizer using high-pressure water is preferable in that the shape after pulverization of the calcium compound becomes a cubic shape and is excellent in permeability to mortar and concrete.

As the ultrasonic device, a high output ultrasonic machine generally called a homogenizer is preferable. The high-speed stirrer preferably has a structure that not only simply rotates the stirrer at a high speed but also a so-called turbulent state and a shear force acts on the particles. For example, trade names “Sharp Flow Mill” manufactured by Taiheiyo Kiko Co., Ltd., trade names “Homomixer”, “Homomic Line Mill”, “Homo Dispers” manufactured by Tokushu Kika Kogyo Co., Ltd., and the like. Further, the medium agitating mill is preferably pulverized using beads of 1 mm or less. As the media agitation mill for grinding using beads of 1 mm or less, the product name “Star Mill” manufactured by Ashizawa Finetech Co., Ltd., the product name “SC-Mill” manufactured by Mitsui Mining Co., Ltd., and the product name “Dual Apex Mill” manufactured by Kotobuki Industries Co., Ltd. Etc. A pulverizer using high-pressure water applies a high pressure of 50 to 400 MPa to the slurry, divides the slurry into two flow paths, and pulverizes them by colliding against each other at a portion where they rejoin. Examples of such a pulverizer include “Starburst” and “Ultimizer” manufactured by Sugino Machine, “Nanomizer” manufactured by Nanomizer, and “Microfluidizer” manufactured by Microfluidics. Among these, “starburst” is preferable in that the dispersion efficiency and the shape after pulverization of the calcium compound are in a cubic shape and have excellent permeability to mortar and concrete.

Furthermore, it is preferable to contain a polymer dispersion from the viewpoint of maintaining appropriate plasticity and preventing dry cracking of the inorganic coating composition. The polymer dispersion is selected from the group consisting of a styrene acrylic copolymer, an acrylic copolymer, an epoxy resin, an ethylene-vinyl alcohol copolymer, an ethylene-acrylic acid copolymer, and an ethylene-acrylic acid ester copolymer. It is preferable to contain 1 type or 2 types or more. Among these, an ethylene-vinyl alcohol copolymer is more preferable because it is effective in a small amount.

The amount of polymer dispersion used (in terms of solid content, the same applies hereinafter) is preferably 10 parts or less, more preferably 0.1 to 5 parts, and most preferably 0.5 to 3 parts with respect to 100 parts of fine particle silica as the main component. . When the addition amount exceeds 10 parts, the viscosity increases and the workability may be poor.

The inorganic coating composition of the present invention can contain a curing time adjusting agent in order to adjust the curing time. The curing time adjusting agent is not particularly limited, but examples thereof include known inorganic salts such as alkali metal sulfates, alkali metal carbonates, alkali metal bicarbonates, alkali metal phosphates, gluconic acid, tartaric acid, citric acid. One or two or more types selected from organic acids such as acid, malic acid and lactic acid, salts of the organic acids, and the like can be mentioned. Among these, alkali metal sulfates and / or alkali metal carbonates are preferable from the viewpoint of salt barrier properties, and alkali metal sulfates are more preferable. Examples of the alkali metal sulfate include sodium sulfate and potassium sulfate.

The amount of the curing time adjuster used is preferably 30 parts or less, more preferably 0.1 to 30 parts, and most preferably 1 to 10 parts with respect to 100 parts of the calcium compound. If the curing time adjusting agent exceeds 30 parts, workability may be poor.

The mixing ratio of the main agent and the curing agent is preferably 5: 1 to 1: 5, and more preferably 2: 1 to 1: 2.

In the inorganic coating composition of the present invention, commonly used additives such as antifoaming agents, leveling agents, ultraviolet absorbers, viscosity modifiers, antioxidants, anti-oxidants are used depending on the functions required of the coating film. A mildew agent etc. can be added suitably. In addition, in order to color the coating film according to the purpose, it is possible to blend various pigments commonly used for coatings, such as titania, zirconia, white lead, bengara and the like.

In order to form a coating film with the inorganic coating composition of the present invention, the coating composition may be coated on the surface of the substrate by a known method. The application means is not particularly limited, and known methods such as spray coater, dipping, brushing, roller finishing, bar coater and the like can be appropriately employed.

The inorganic coating composition of the present invention is a room temperature curing type, and is naturally cured by a hydration reaction at room temperature. Thereby, it can use preferably also for places, such as a tunnel inner wall and bridge painting which cannot apply high temperature for hardening.
The coating film formed by the method of the present invention preferably has a thickness of 10 to 500 μm. If the coating film is less than 10 μm, the durability may not be sufficient, and if the coating film thickness exceeds 500 μm, the coating film may be cracked, which is not preferable.

The substrate on which the inorganic coating composition of the present invention is applied is not particularly limited, and examples thereof include concrete, mortar, slate, glass, enamel, and metal.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Examples were performed at 20 ° C. unless otherwise specified.

Example 1

(Adjustment of inorganic coating composition)
Mix 100 parts of fine particle silica with different particle sizes and types, 5 parts of dispersant (in terms of solid content), and 100 parts of water, wet-disperse with the product name “Starburst” manufactured by Sugino Machine Co., and add polymer dispersion. The main agent was prepared. On the other hand, 100 parts of commercially available calcium hydroxide (average particle size 9.5 μm), 10 parts of a dispersant, and 150 parts of water are mixed, and similarly, wet dispersion is performed by changing the pulverization time using the product name “Starburst” manufactured by Sugino Machine. Then, a curing time adjusting agent was added to prepare a curing agent.
The pressure applied to the starburst slurry was all 245 MPa.
The main agent and the curing agent were mixed so that the amount of the calcium compound used was 75 parts with respect to 100 parts of fine particle silica, and an inorganic coating composition was prepared with the formulation shown in Table 1.
The fine particle silica was produced by a method in which a slurry in which metal silicon powder was dispersed was injected into a flame and burned and oxidized.

(Materials used)
Fine particle silica S1: Average particle size 0.05 μm
Fine-particle silica S2: average particle size 0.1 μm
Fine particle silica S3: average particle size 0.6 μm
Fine particle silica S4: average particle size 1.0 μm
Fine particle silica S5: average particle size 3.5 μm
Ferrosilicon by-product silica fume S6: Average particle size 1.5 μm (20 μm when not ultrasonically treated)
Silica sol S7: Average particle size 10.1 μm
Calcium compound C1: Average particle size 0.05 μm, Calcium hydroxide calcium compound C2: Average particle size 0.1 μm, Calcium hydroxide calcium compound C3: Average particle size 0.5 μm, Calcium hydroxide calcium compound C4: Average particle size 1 0.0 μm, calcium hydroxide calcium compound C5: average particle size 3.5 μm (average particle size when sonicated is 0.5 μm), calcium hydroxide dispersant: commercially available naphthalene sulfonic acid series, liquid, solid concentration 40%
Polymer dispersion: Polymer dispersion curing time regulator made of ethylene-vinyl alcohol copolymer: Sodium sulfate, Commercial water: Tap water

(Test substrate production)
An inorganic coating composition was applied to the surface of a 10 × 10 × 10 cm mortar specimen so as to have a film thickness of 100 μm, and the test was conducted by the method described below. The results are shown in Table 1.

(1) Normal adhesion test A mortar specimen cured at 20 ° C for 3 days after application was subjected to an adhesion test according to JIS K 5600-5-6.
The classification of the test results in Table 1 of JIS K 5600-5-6 was determined from 0 (no peeling) to 5 (large peeling).

(2) A mortar specimen cured at 20 ° C. for 3 days after applying the hot water resistance test was immersed in warm water at 80 ° C. for 1 day, taken out, and dried at 60 ° C. for 4 hours. This mortar specimen was subjected to an adhesion test according to JISK 5600-5-6.
The classification of the test results in Table 1 of JIS K 5600-5-6 was determined from 0 (no peeling) to 5 (large peeling).

(3) Chloride ion penetration depth The chloride ion penetration depth of a mortar specimen tested according to JIS A 1171 was measured.

It turns out that it is excellent in normal state adhesiveness, warm water resistance, and chloride ion permeability by using a specific fine particle silica and a specific calcium compound. Furthermore, it turns out that performance improves further by combined use of a polymer dispersion and a curing time regulator.

The inorganic coating composition of the present invention can be applied to the coating of concrete, mortar, slate, glass, enamel, metal, etc., for example, interior material coating of buildings that require non-combustibility, railways that require salt barrier properties It can be suitably used for fields such as road piers, sound deadening walls and floor slabs, and tunnel inner wall painting that requires high heat resistance and wear resistance.

Since the average particle diameter of the fine particle silica or calcium compound is as fine as 1.0 μm or less, the present invention penetrates into mortar and concrete, and is excellent in waterproofness, salt barrier property, neutralization resistance, chemical resistance, etc. .

Claims (7)

A main agent comprising a particulate silica and horizontal Hitoshitsubu diameter is 1.0 .mu.m or less, the following calcium compound Rights Hitoshitsubu径1.0 .mu.m, are mixed with a curing agent comprising a dispersing agent and water This is a method for producing an inorganic coating composition, in which fine-particle silica and a calcium compound are subjected to a high pressure of 50 to 400 MPa to the slurry, the slurry is branched into two flow paths, and colliding again at the part where they merge again It is manufactured using a pulverizer using high-pressure water that is pulverized, and the dispersant is a sulfonated melamine-based, naphthalenesulfonic acid-based, polycarboxylic acid-based, or polyether-based group The manufacturing method of the inorganic type coating composition which is 1 type selected or 2 types or more. Method for producing a calcium compound, inorganic-based coating composition according to claim 1 which is calcium hydroxide. The usage-amount of the dispersing agent in a hardening | curing agent is 1-30 parts (solid content conversion) with respect to 100 parts of calcium compounds, The inorganic type coating composition as described in any one of Claims 1-2. Production method. Further , one or two selected from the group consisting of styrene acrylic copolymer, acrylic copolymer, epoxy resin, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer The manufacturing method of the inorganic type coating composition as described in any one of Claims 1-3 formed by containing 0.1-10 parts or less of polymer dispersion which is the above with respect to 100 parts of particulate silica . Furthermore , 0.1-30 parts of hardening time regulators are contained with respect to 100 parts of calcium compounds , The manufacturing method of the inorganic type coating composition as described in any one of Claims 1-4 . A fine particle silica is produced by a method in which a slurry in which fine metal silica is dispersed in a metal silicon powder is injected into a flame to burn and oxidize, and the concentration of fine particle silica in the main agent is 10 to 80%, and a calcium compound is used. The amount is 20 to 200 parts with respect to 100 parts of fine particle silica, the concentration of the calcium compound in the curing agent is 5 to 60%, and the mixing ratio of the main agent and the curing agent is 5: 1 to 1: 5. The dispersant is naphthalene sulfonic acid, and 1 to 30 parts (in terms of solid content) of the dispersant is used as the main component with respect to 100 parts of the fine particle silica. The manufacturing method of the inorganic-type coating composition of description. Furthermore, the polymer dispersion which is an ethylene-vinyl alcohol copolymer is contained in a main ingredient, The hardening time regulator which is sodium sulfate is contained in a hardening | curing agent, The hardener contains any one of Claims 1-6. A method for producing an inorganic coating composition.