JPH0775699B2 - Surface protection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface protection method for iron plates, steel frames, aluminum plates, bridges, bridge piers, tanks, roofs, pipes, stairs, concrete surfaces and the like.

[0002]

2. Description of the Related Art As is well known, in order to prevent the occurrence of rust and damage, the surface is coated.

[0003] paints used for the coating, although the recent years has been greatly improved, the synthetic polymer resin solvent type, fluorine type, acrylic silicone resin, epoxy resin, other reaction curing type which is characterized in durability There are many types, but the coating thickness is thin, and the thickness is about 0.1 mm or less. Therefore, the surface coating film is damaged by flying objects such as sand dust, and reaches the iron surface to grow rust.
Thus, it is inferior in resistance to external stimuli such as impact and abrasion. In addition, organic solvents are difficult to handle due to human problems and flammability. In addition, since it is an organic substance, it is affected by ultraviolet rays (sun rays), ozone, NOx / SOx, etc., and "degradation of the coating film" and "solidification of the coating film" occur over time.
In general, as the colorant, an organic colorant is often used, and thus fading and discoloration are remarkable. Therefore, the rust preventive effect also declines, and rust is generated every 3 to 5 years depending on external conditions, and repainting becomes necessary. In reality, the cost for repainting is higher than the initial painting cost including scaffolding and keren.

Further, conventionally, as a method for preventing rusting and corrosive protection of iron surfaces, rust-preventing materials such as lead compounds, chromium compounds and zinc powder are mixed with a spreading agent (binder) such as synthetic resin. The most commonly used coating is a stop paint.

[0005] However, this and the like is generally a solvent-based, safety, resource saving, also problematic from the hygiene and the like. Since the binder used is organic, the rust-preventing effect also deteriorates, and depending on external conditions, rust will occur every 3 to 5 years, and repainting becomes necessary. Further, since the film thickness is generally as thin as 0.1 mm or less, a problem may occur in wear resistance.

On the other hand, various anti-corrosion methods other than these organic anticorrosive coating have been proposed and adopted. For example, iron pipes are coated with cement mortar to passivate the iron surface in an alkaline atmosphere of cement, but cement mortar alone lacks adhesion to the iron surface and causes drying. Its applications are remarkably limited due to the generation of cracks due to shrinkage, lack of mechanical strength and impact resistance.

[0007] In order to improve these drawbacks, a rust preventive method of applying a polymer cement mortar obtained by adding a synthetic resin emulsion compatible with the cement mortar to the iron surface has been carried out, but it is also water resistant. Power, waterproofness,
There is a problem with air permeability.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a surface protective layer which has excellent adhesion and impact resistance, forms a strong coating film at room temperature, and has excellent rust-preventing power and surface protective power, quickly and inexpensively. An object of the present invention is to provide a surface protection method that can be formed.

[0009]

The present invention has been made to solve the above-mentioned problems, and a plurality of materials are laminated by a spraying method or a combination with a brush coating, and the characteristics of each material are utilized to obtain the It is a surface protection method characterized by forming protective layers that compensate for the defects of the materials.

[0010] Namely, the present invention is spray method alone, or one which forms a protective layer in combination with brushing, protective layer, an undercoat layer A, coating layer B (poly earth cement mortar layer), a sealer The undercoat layer A is formed of a layer C and a top layer D, and a polyacrylic ester (PA
E), a cyclic fatty acid salt (for example, sodium benzoate)
Of the coating film layer B is used as a main material, which is a mixture of a thickener, a defoaming agent, a dispersant, a pigment, etc. For the formation, a powder in which a thickener, a fluidizer, an antifoaming agent, a fiber, a pigment aggregate and the like are mixed with cement and a resin solid content in the coating material is 5% to
A composite material consisting of 7% polyacrylic acid ester (PAE) is used, a synthetic polymer emulsion polyacrylic acid ester (PAE) is used for forming the sealer layer C, and a top layer D is formed. Acrylic synthetic polymer emulsion (clear) or silicone acrylic paint is used.

The total coating thickness of four layers is 1.7 mm.
Hereinafter, it is preferable that the dried resin is substantially 1.3 mm, and the resin solid content in the polymer cement mortar is 5% or more.

For the coloring, usually, only an inorganic fired pigment is used,
Do not use any organic type. Therefore, it cannot be said that it is full of vivid aesthetics. When aesthetics are required, a method of finishing using a silicone-acrylic type organic / inorganic composite resin paint (durability and stain resistance are comparable to fluororesin) as the top coat (top layer) is adopted.

[0013]

The undercoat layer A is for rust prevention, has a strong adhesion to metal, concrete surface, etc., and the cyclic fatty acid salt (for example, sodium benzoate) constituting the material used exerts a rust preventive effect. The aggregate improves the adhesion of the coating layer to be applied in the next step.

The coating layer B has a thickness of 1.2-by spraying twice.
By forming a coating thickness of 1.6 mm and making use of the long-term strength and durability of the cement used, the bending strength, compactness, low shrinkability, waterproofness, adhesiveness, salt resistance, which are the drawbacks of cement,
For the antirust property, polyacrylic acid ester (PAE), which is a synthetic high molecular polymer to be blended, covers it. The reason why the number of coating layers is two is not limited to spraying in the case of one layer, but pinholes are always generated in hydrated products, water vaporized substances, etc., which adversely affects rust prevention ability and the like. It is to give and to prevent it.

Since the sealer layer C may have pinholes, pores, and capillaries remaining even if the coating layer B has two layers, a dense sealer layer C is formed on the sealer layer C to improve waterproofness and rust resistance. This construction forms a sealed tissue structure that does not allow O ₂ or chlorine ions in water or air to pass to the ground.

Further , the top layer D has a function of filling the pinhole generated in the sealer layer C itself and improving the stain resistance.

[0017]

EXAMPLE FIG. 1 shows an example of the present invention, in which X is an iron plate to be protected, A is an undercoat layer, B is a coating layer, C is a sealer layer, and D is a top layer.

The undercoat layer A (primer) is a polyacrylic acid ester (PAE) which is a synthetic polymer emulsion.
In order to improve the adhesion of the coating layer B formed by spraying sodium benzoate, which is a kind of cyclic fatty acid salt, as a rust preventive agent for enhancing the rust preventive effect, and further spraying it in a later step. Aggregates with a size of 3 mm or less are mixed, and a thickener,
A defoaming agent, a dispersant, a pigment, etc. are blended, and the construction is carried out by spraying, brushing, rollers or the like.

When the undercoat layer A is applied to the surface of the iron plate X, it is estimated from the results of a salt spray test that a rust preventive effect equivalent to about two years can be obtained, and a strong adhesive force is exhibited.

The coating layer B is a powder obtained by mixing a cement with a thickening agent, a fluidizing agent, a defoaming agent, fibers, a pigment, an aggregate and the like, and a polyacrylic acid ester (PAE) which is a synthetic polymer emulsion. It is a layer formed by spraying a polymer cement-based composite material consisting of and, and has a coating thickness of 1.2 to 1.6 mm by two sprays.

[0021] The coating layer B is long strength, taking advantage of the durability, flexural strength is a disadvantage of cement with the cement,
Dense, waterproof, adhesive, salt-proof, rust-proof, etc. are imparted by a synthetic polymer.

In the examples, the spraying twice is not limited to spraying and coating, but pinholes are always formed in hydrated products, water vaporized products, etc., and this has a significant adverse effect on rust prevention and the like. To give, it is sprayed twice to form two layers.

[0023] After drying of the undercoat layer A, when blowing the first to form a coating layer B, and usually pinholes occur. However, if two layers are formed by spraying twice, it is extremely unlikely that the pinholes will overlap directly above the pinholes, and the pinholes in the first layer will be filled.
There is no risk of rust due to pinholes.

The sealer layer C is formed by spraying or brushing using polyacrylic acid ester (PAE) which is a synthetic polymer emulsion.

The coating layers pinhole in B, pore, since the capillary is present slightly, forming a sealer layer C, to form a dense coating film, water resistance, improving the rust resistance. By adopting a construction method of impregnating and filling such a resin into a pinhole or the like, a sealed tissue structure which does not pass O ₂ or chlorine ions in water or air to the iron surface is formed.

The top layer D is formed by spraying, and as the material thereof, one of the following two materials is used.

[0027] The acrylic-based synthetic polymer Emarujun
(Kuriya)

[0028] The silicon acrylic paint

The top layer D fills the pinholes formed in the sealer layer C and improves the stain resistance.

For the coloring of the protective layer according to the present invention, usually only an inorganic calcined pigment is used and no organic pigment is used. Therefore, it cannot be said that it is full of vivid aesthetics. Therefore, when aesthetics are required, a method of overcoating with a silicone-acrylic (organic / inorganic composite resin paint) (durability and stain resistance is comparable to that of fluororesin) paint is used.

The total coating thickness of the protective layer formed on the surface of the iron plate X is 1.5～1.7Mm, coating thickness after drying substantially 1.
3 to 1.5 mm, using polyacrylic acid ester (PAE) which is a synthetic polymer emulsion to be used,
In addition, by setting the resin solid content in the polymer cement mortar to 5% or more, it has excellent durability and long-term rust preventive effect, and is resistant to external impact and stimuli such as abrasion. It became an inorganic surface protection layer.

The present invention thus uses a plurality of materials,
Utilizing the material characteristics (advantages) of forming each layer by stacking, using a stacking recipe that compensates for defects, and in order to improve work efficiency, it is a spraying method and it is possible to perform chasing stacking work. Is.

[0033] Next described materials and test results used in the present invention embodiment. The test results are obtained by observing and examining the change in the rusting condition with time due to salt spray when the construction process was changed from one-layer finish to four-layer finish.

The raw materials constituting the primer A in the examples of the present invention and the compounding examples thereof are shown in Table 1. In addition, these raw materials and compounding examples were prepared by selecting raw materials and studying appropriate compounding so that the adhesion to the iron plate and the rust preventive power could be maximized.

[0035]

[Table 1]

[0036] If Shimese compounding of raw materials (powder) constituting the coating layer B in the present invention embodiment and its kneading conditions are shown in Table 2. Note that these raw materials and compounding examples were prepared by selecting the raw materials that maximize the long-term strength, durability, bending strength, compactness, adhesiveness, and impact resistance, and examining the proper compounding. .

[0037]

[Table 2]

[0038]

[Salt water spray test method] The test piece is hung in a humidity box with a temperature of 40 ° C and a humidity of 100%, and a mixture of 3% saline solution and 1% sodium sulfate water is sprayed from a humidifier to check the rust condition over time. The change was observed.

[0039] (3 months out)

The method for molding the specimen of this example is shown below.

[0041]

[Outer 1] The size of the test plate was (80 × 160 × 1 mm) ordinary iron plate.・ The primer was brushed on the iron plate. Coating amount is 0.1k
It was set to g / m ² . -After becoming dry, the first mixture was sprayed with the Wider Spray Gun W-77. The spray rate was 1.5 kg / m ² .・ The mixture was mixed for 90 seconds using a high speed hand mixer of 1000 RPM to dissolve a trace amount of components.・ A spray gun is used for spraying the mixture. The diameter of the spray gun is 1.2 mm and the air pressure during spraying is 5 kg.
It was set to f / cm ² .・ The second mixture was shot in the same way as the first.・ After it became dry, brushed the sealer. The coating amount was 0.07 kg / m ² .・ After the sealer became dry, the top was brushed. The coating amount of acrylic type and silicon allyl type was also 0.07 kg / m ² .・ The test was started with a curing period of 2 weeks.

[0042] When showing the test results of the inventive examples is shown in Table 3.

[0043]

[Table 3]

Rust formation was confirmed in all of the ones in which the number of steps was shortened from one layer to three layers. No rusting was observed in the four-layered test body.

[0045] NO. As with 4 samples, when 3 layers were stopped (3 layers finish), there was tack on the sealer, and the spray finish was slightly uneven, so dust etc. adhered,
It was heavily polluted and failed in construction.

When water vapor was sprayed by heating at 100 ° C., blister was observed in the sealer portion in the three-layer finish, but no generation was observed in the four-layer finish. Thus, the step of applying the top as the stain resistant sealer on the fourth layer is important.

Further , the top layer D (acrylic,
We tried to simplify the process by finishing with only (silicone acrylic), but it was also found to be inferior in rust prevention.

In terms of formulation, cracking occurred when the amount of cement was large, and it became noticeable when it was applied thickly. Also, if fibers are not mixed in, they will sag, and thick coating requires fibers.

[0049] The coating layer of aggregate B is a continuous particle size,
I reduced the space. Also, knead into powder that constitutes the coating layer B
When the resin solid content of the mixed synthetic polymer emulsion was 5% or less, 1% and 3%, there was rusting, and rustproofing power was not obtained, but 5% was confirmed to contribute to rustproofing power. It was Further, the spraying work was good up to about 5% to 7%, but was not sprayed between 7% and 10% because the synthetic polymer emulsion became extremely thick.

[0050] Thus, using the multi-material, by laminating, taking advantage of the material properties (strengths) forming a layer of each, a laminated formulation redeeming, and in spraying method in order to increase the work efficiency , Chasing lamination work (interval time of each process (1) after spraying the primer, interval time: 30 minutes, (2)
First mixture spray, chasing in a dry state Second mixture spray, after Interval time: 2 hours, (3)
It was found that the interval time after spraying the sealer: 1 hour, (4) spraying on top) is possible.

[0051] Next described rusting state when changing the type and the resin solids of the emulsion.

[0052] Table 4 The type of emulsion, acrylic, EVA-based, vinegar Bibeoba system, and for the resin solids, in the case of changing the 1,3,5 (%),
This is the result of observing and investigating the change in the rusting situation with time due to salt spray.

For comparison, the case of a primer (without rust preventive, containing rust preventive) and a commercially available three-layer paint is also shown.

[0054] Incidentally, the powder formulation of Mixture, kneading conditions, construction methods and primer treatment method according spraying method salt spray test, specimens forming method and training time is the same as that described above.

[0055]

[Table 4]

[0056] In this test, as shown in the results, the comparative acrylic emulsion, EVA-based emulsion for comparison, comparative vinegar Bibeoba-based emulsion, and a resin solid content of 1% At a present invention formulation, 3%, and rust inhibitor None, only the primer containing the anticorrosive agent and the general commercial three-layer paint were confirmed to rust.

Further, the resin solid content ratio of polyacrylic acid ester which is a synthetic polymer emulsion formulated in the coating layer B.
It was confirmed that 1% and 3% of 5% or less caused rusting and no rustproofing ability was obtained, but 5 %% contributed rustproofing ability.

The spraying work was good at about 5% to 7%, but the spraying was not possible at 7% to 10% because the synthetic polymer emulsion became extremely thick.

As described above, as the synthetic polymer emulsion formulated in the coating layer B, polyacrylic acid ester (PA
It was found that E) was used and the resin solid content in the polymer cement mortar was 5% or more, which was the most suitable material for exhibiting excellent durability and long-term rust prevention effect.

[0060] Next described test results for immersion in hot water and repeatedly rusting conditions and adhesion strength after weathering.

In this test, the coating thickness of the coating layer B of the present invention was 0.5 mm, 1.0 mm, 1.5 mm, 2.5 m.
The rusting condition and the adhesion strength after repeated immersion in warm water and outdoor exposure when the thickness was changed to 3.0 mm and 3.0 mm were examined, and the results are shown in Table 5.

[0062] After 24-hour hot water immersion in warm water (90 ℃), 2
The outdoor exposure for 4 hours was repeated for 6 months, and the rusting condition of the surface of the test body was observed.

[0063] However, adhesion strength test and drop test was carried out at the time of 5 months after the start of the test. Regarding the drop test conditions, the state of the coating film when the test body was dropped onto the concrete floor 20 times from a height of 1 m was confirmed. Table 6 shows the test results.

The powder mixture of the coating layer B, the kneading conditions, the construction method by spraying and the primer treatment method are the same as those described above.

The test plate (80 × 160 × 1 mm) is a normal iron plate having a thickness of 1 mm.

[0066] takes a position 10 years in outdoor standing.

It takes about 5 to 6 years outdoors under a high humidity (without NaCl) condition.

[0068] during the day, at night constantly high humidity (humidity of 95% or more), it takes 6 months under NaCl spray.

It takes 6 months to repeat high temperature (100 ° C. or less) high humidity to normal temperature drying.

[0070] high temperature (100 ° C. or less) and humidity-dried at normal temperature, the repetition in the presence of NaCl, takes three months.

[0071]

[Table 5]

[0072]

[Table 6]

In the above test example, the coating thickness is 0.5 mm,
At 1.0 mm, rusting was confirmed in 4 months and 5 months. Also, above that, no rusting is seen on the surface of the coating film,
It was confirmed that the steel surface on the back side was torn and bite into the edge. Due to these reasons, the coating thickness was set to about 1.5 mm in view of economy, workability and physical properties.

At the age of 6 months, no rust was found on the surface of the coating film even when the back of the iron was torn, indicating that this coating film has a rust preventive power of about 10 years. Presumed.

The above-mentioned embodiment of the present invention and ordinary Portland cement / Toyoura standard sand = 1/3, and the water-cement ratio is 85%.
Comparing various characteristics with the cement mortar (comparative example),
The results are shown in Table 7.

[0076]

[Table 7]

[0077]

EFFECTS OF THE INVENTION The rust preventive effect of commonly used paints varies depending on external conditions, but rust occurs every 3 to 5 years, and repainting is required. The rust preventive power by the laminated coating film method of the present invention has been for 10 years,
~ 3 times more rustproof effect is obtained. 1 to repaint cycle
You can omit it twice.

[0078] The cost for the re-painting, 15 of the total cost
% Is material and construction cost, 85% is scaffolding and keren cost, and it is more than initial coating cost. 1
The cost can be reduced by eliminating the need for repainting.

[0079] According to a survey of Japanese anti-corrosion Technology Association, there are statistics that about 5% of GNP for rust, 2 trillion 500 billion yen is being used in day year, also, the University of Tokyo, according to Masuko professor There is a report that iron is rusted at 1 ton per minute and 500,000 ton per year.

As a result, it is a great merit that the repainting cycle can be omitted once or twice.

As described above, the surface protection method according to the present invention has a strong adhesion to the object to be protected, excellent durability and impact resistance, and has an effect of having a rust preventive effect for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 X Iron plate A Undercoat layer B Coating layer C Sealer layer D Top layer

Claims (2)

[Claims] 1. An undercoat layer A mainly composed of a polyacrylic acid ester containing an aggregate having a size of 0.3 mm or less and a cyclic fatty acid salt on a surface to be protected, and a resin solid content in cement.
Coating layer B, sealer layer C and top layer D in which 5% to 7% of polyacrylic acid ester, a thickener and a fluidizing agent are blended
Surface protection method characterized by sequentially forming. 2. The surface protection method according to claim 1, wherein the coating layer B has two layers.