JPH02111678A - Method for preventing rust of metallic material in inorganic material, such as concrete - Google Patents

Abstract

PURPOSE:To enhance affinity, water repellency and salt cutting off properties and improve rust preventive properties of a metallic material by applying or impregnating an aqueous solution of inorganic salts and/or silicate into the surface of an inorganic material containing a the metallic material therein and then applying an organic titanate thereto. CONSTITUTION:An aqueous solution of inorganic salts (e.g., calcium phosphate) and/or a silicate compound (e.g., lithium silicate) is applied and impregnated into the surface of an inorganic material, such as concrete, containing a metallic material therein and a treating agent prepared by dissolving an organic titanate (e.g., isopropyl trioctanoyl titanate) in an organic solvent in a coating amount of 10-600g/m<2> is then applied and impregnated thereinto. A synthetic resin (e.g., fluororesin), as necessary, in a coating amount of tens to thousands of g/m2 is applied to form a film.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to bridges that are susceptible to salt damage, marine structures, RC, SRC, lath mortar, SPl? The present invention relates to a method for preventing rusting of metal materials such as steel materials built into inorganic materials such as C-built buildings.

(Prior Art) Conventionally, as a rust prevention method for steel materials such as metal materials, as disclosed in JP-A-81-158880, for example, a rust prevention method using a polyhydric alcohol-based nitroester as a main component has been used. A method of sequentially applying a rust agent, an aqueous alkali metal salt solution exhibiting alkalinity with a pH of 10 or more when dissolved in water, and a silicone-based penetrating water repellent to the surface of an inorganic material such as concrete, and JP-A-82 - A method of sequentially applying an aqueous solution of inorganic salts and a silicone-based or silane-based brimer to the surface of an inorganic material such as concrete, as disclosed in Publication No. 74090, or a method of further applying paint on the brimer, Furthermore, as disclosed in Japanese Unexamined Patent Publication No. 57-201444, a method is known in which a coating film containing a synthetic resin having a glass transition point of 0 DEG C. or lower is formed on the surface of an inorganic material such as concrete.

(Problem to be Solved by the Invention) However, among the above rust prevention methods, a rust preventive agent made of a polyhydric alcohol-based nitroester, a rust preventive agent made of an aqueous alkali metal salt solution, and a silicon-based penetrating water repellent are used. In the case of a sequential application method, there are problems such as poor reliability of water repellency and air barrier properties of the silicone water repellent agent, and poor durability of water repellency and air barrier properties.

Furthermore, in the case of the method of sequentially applying an aqueous solution of inorganic salts and a silicone-based or silane-based brimer, there are problems with the durability of the brimer's water repellency and air-blocking properties, and if additional paint is applied on top of the brimer, In addition to the above-mentioned problems, when a resin is used as the main component of the paint, there are restrictions on the selection of the resin, the weather resistance over time is poor, and the price is extremely high.

In addition, in the case of a method of forming a synthetic resin coating film with a glass transition point of 0°C or lower, the adhesion between the inorganic concrete surface and the organic coating film is low, which tends to cause floating and peeling, and water repellency. There are problems such as poor salt-forming properties, poor air barrier properties, and other problems.

The present invention solves the above problems and has air barrier properties, water resistance,
It is an object of the present invention to provide a method for preventing rust of metal materials in inorganic materials such as concrete, which can improve the salt forming property or durability and the rust prevention of built-in metal materials.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a method for applying and impregnating an inorganic salt aqueous solution and/or a silicate compound aqueous solution onto the surface of an inorganic material such as concrete containing a metal material. , which is characterized by applying and impregnating a treatment agent containing organic titanate as a main component.

Further, after the treatment agent is applied and impregnated, a film containing a synthetic resin as a main component may be formed on the treatment agent.

In addition, a treatment agent mainly composed of organic titanate is applied to the surface of an inorganic material such as concrete containing a metal material, and after impregnation, a film mainly composed of a synthetic resin is formed on the treatment agent. Good too.

The treatment agent mainly composed of organic titanate used in the present invention has good affinity with inorganic materials such as concrete,
In addition, from the viewpoint of not having any restrictions on the selectivity of the synthetic resin forming the coating, for example, the general formula % formula %) "However, in the formula, n elements θ ~ 3.5 R Nialkyl group Ro: alkyl group, alkenyl group, aralkyl Some of the groups R and R' are halogen groups, nitro groups, amino groups,
carboxyl group, epoxy group, hydroxyether group,
It may be substituted with an ester group. isopropyltrioctanoyl titanate,
Diisopropoxytitanium distearate, tri-n-butoxytitanium monostearate, isopropoxytitanium tristearate, or the general formula (% formula %) "wherein n -1 to 10 R: an alkyl group." tetraisopropoxy titanium, tetra n-butoxy titanium, tetraisopropoxy titanium polymer,
Tetra n-butoxy titanium polymer or general formula TI (OR) 4-, ・(A) 8 "However, in the formula n -1 to 3 R: Alkyl group A. Residues such as nigericol, oxyorganic acid, polyhydric alcohol amine It is a chelate group having a (Ethyl acetoacetate) An organic solvent-based treatment agent in which one or more organic titanates such as titanium are dissolved in an organic solvent such as toluene or xylene, or one of the organic titanates that forms an adduct with an amine. Examples include water-soluble treatment agents dissolved in water. And the amount of treatment agent applied is lO ~ 600
About g/l.

In addition, the synthetic resin for the coating formed on the treatment agent is as follows:
Examples include fluororesin, silicone resin, acrylic urethane resin, unsaturated polyester resin, vinyl ester resin, acrylic resin, epoxy resin, urethane resin, etc., and any one of these synthetic resins may be used alone,
Alternatively, two or more types may be used in combination. The coating can be formed by coating these synthetic resins directly with N, or by coating them with a paint dissolved in an appropriate solvent. When using two or more types in combination, one coating is formed, and then the coating is coated on top of the coating. The other coating may be formed on the other side. The amount of coating is about several tens to several thousand tlrl. Further, various additives such as glass flakes, additives for improving gas barrier properties such as old 0, pigments, and U2 absorbers may be added to the synthetic resin.

In addition, examples of the inorganic salt aqueous solution that is applied and impregnated onto the surface of the inorganic material before applying the treatment agent containing organic titanate as the main component include calcium nitrite, sodium nitrite,
Examples include aqueous solutions of calcium phosphate, sodium chromate, and the like.

Examples of the silicate compound aqueous solution include aqueous solutions of lithium silicate, potassium silicate, sodium silicate, ammonium silicate, and the like. The aqueous solution may be used alone, or one of the aqueous solutions may be applied and then the other aqueous solution may be applied.

Note that the metal material incorporated in the inorganic material such as concrete may be a metal material such as steel coated with an epoxy resin paint in advance, or a metal material such as galvanized steel.

(Function) By coating and impregnating the surface of an inorganic material with a treatment agent containing organic titanate as a main component, the hydrophilic groups of the organic titanate are firmly bonded to the inorganic material.

Furthermore, by forming a synthetic resin film on the treatment agent, air barrier properties, water resistance, and salt formation properties are significantly improved, and their durability is also improved. This is thought to be because the functional groups of the organic titanate on the inorganic material enhance the affinity with the synthetic resin coating formed on the treated material.

In addition, by applying and impregnating an inorganic salt aqueous solution or/and a silicate compound aqueous solution on the surface of an inorganic material in advance,
The metal material in the inorganic material is provided with rust prevention properties by a coating formed from an aqueous solution, and its strong alkalinity increases the alkalinity in the inorganic material or retards the rate of neutralization.

(Example) Specific examples of the present invention will be described below.

Example 1 500 g of a 30% calcium nitrite aqueous solution was applied to the surface of a columnar structure made of concrete material with a rectangular cross-section, each side length of 30 cm, and a height of 10 cm, containing four reinforcing bars made of metal material with a diameter of 13 mm. After applying the coating and impregnating treatment of d,
10% of isobrobyl triisostearoyl titanate
500 g of toluene solution was applied and impregnated.

After being exposed to 3% salt water spray for 90 days, the concrete material was destroyed and the surface of the metal material was observed, and no abnormality was observed.

Example 2 After coating and impregnating the surface of the same columnar structure as in Example f11 with 500 g/l of a 30% calcium nitrite aqueous solution, 300 g/l of a 10% toluene solution of isopropyl triisostearoyl titanate was applied, After the impregnation, 800 g/d of urethane resin paint was applied to form a urethane resin coating.

When the surface of the metal material was observed in the same manner as in Example 1, no abnormality was observed.

Example 3 300 g/ml of a 10% toluene solution of isopropyl triisostearoyl titanate was applied to the surface of the same columnar structure as in Example 1 to impregnate it, and then 800 g/l of urethane resin paint was applied. A resin film was formed. When the surface of the metal material was observed in the same manner as in Example 1, no abnormality was observed.

(Effects of the Invention) As is clear from the above, according to the present invention, a treatment agent containing an organic titanate as a main component is applied to the surface of an inorganic material such as concrete containing a metal material and is impregnated. It has the effect of improving the rust prevention of built-in metal materials by modifying the surface of inorganic materials such as concrete to improve affinity, water repellency, and heat insulation.

In addition, a treatment agent mainly composed of organic titanate is applied to the surface of an inorganic material such as concrete that contains metal materials, and after the treatment agent is impregnated, a film mainly composed of synthetic resin is formed on the treatment agent. Therefore, due to its affinity with a treatment agent containing organic titanate as a main component, it is possible to further improve the durability of waterproofing and heat shielding properties, thereby further improving the rust prevention properties of metal materials.

In addition, before applying a treatment agent containing organic titanate as a main component, by coating and impregnating the surface of concrete or inorganic materials with an aqueous solution of inorganic salts and/or silicate compounds, the metal materials in the inorganic materials can be treated with an aqueous solution. The film formed from the above imparts rust prevention properties, increases the alkalinity in the inorganic material, or delays the neutralization rate, thereby improving the rust prevention properties of metal materials.

Claims (1)

[Claims] 1. After coating and impregnating the surface of an inorganic material such as concrete containing a metal material with an aqueous inorganic salt solution or/and an aqueous silicate compound solution, a treatment agent containing an organic titanate as a main component is applied. A rust prevention method for metal materials in inorganic materials such as concrete, which is characterized by impregnating the metal materials. 2. After coating and impregnating the surface of an inorganic material such as concrete containing a metal material with an inorganic salt aqueous solution or/and a silicate compound aqueous solution, a treatment agent containing organic titanate as a main component is applied and impregnated. A method for preventing rust of a metal material in an inorganic material such as concrete, which comprises forming a film mainly composed of a synthetic resin on the treatment agent. 3. After applying a treatment agent mainly composed of organic titanate to the surface of an inorganic material such as concrete containing a metal material and allowing it to be impregnated, a film mainly composed of synthetic resin is formed on the treatment agent. A method for preventing rust of metal materials in inorganic materials such as concrete.