JP2555164B2 - Anticorrosion construction method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an anticorrosion construction method for performing anticorrosion construction on an anticorrosion portion placed in an environment where water is present, particularly a portion having many pitting irregularities and the like. is there.

[Conventional technology]

In recent years, there has been an increasing demand for anti-corrosion construction such as oil drilling jigs or purging of oil reserves, and platform piles in seawater, which accompany ocean development. When performing anticorrosion construction on such seawater or parts that are splashed,
Since it is almost impossible to move the above-mentioned structure from the installation place to another place, it has to be carried out under the condition where seawater or splashes are applied. As the anticorrosion construction material for such a portion, a coating material composed of a two-component room temperature curable epoxy resin composition generally composed of a main component mainly composed of an epoxy resin and a curing agent mainly composed of a curing component is used. There is. In this case, as the curing agent,
Those that cause a hardening action in the presence of water are used.

[Problems to be solved by the invention]

Using such an underwater curable epoxy resin composition,
Corrosion-resistant part (construction surface) placed in an environment where water is present
On the other hand, when performing anticorrosion construction, if the epoxy resin composition is a low viscosity one using a tar-modified epoxy resin or vinyl acetate-modified epoxy resin, etc. Due to hydraulic power, the epoxy resin composition is washed away until it is cured, and it is difficult to obtain a thick anticorrosive coating film. Further, the coating material composed of the low viscosity epoxy resin composition as described above,
Even if it adheres to the smooth portion, it is difficult to adhere to the pitting portion with severe irregularities and the claw portion of the steel pipe sheet pile, and therefore, together with the fact that the epoxy resin composition is flowed by hydraulic force, There is a problem in anticorrosion construction of these parts.

On the other hand, in addition to the above low-viscosity epoxy resin composition, a high-viscosity underwater curable epoxy resin composition using polyamidoamine as a curing agent component has also been developed. However, although this type of epoxy resin composition has good adhesion to the above-mentioned pitting portion, irregular-shaped portion, etc., it has a problem in long-term anticorrosion property because the above-mentioned polyamidoamine is highly hydrophilic.

The present invention has been made in view of such circumstances,
An object of the present invention is to provide an anticorrosion construction method capable of forming a thick coating film even when subjected to hydraulic force due to water flow or water pressure, and capable of exhibiting excellent anticorrosion performance over a long period of time.

[Means for solving problems]

In order to achieve the above object, the anticorrosion construction method of the present invention is a two-pack type underwater-curable epoxy resin composition containing the following components (A) and (B) as the main components and having a consistency.
After forming an undercoat layer on the work surface with a high-viscosity putty-like underwater-curable epoxy resin composition (I) set to 30 to 300 at 23 ° C., the following (A) and (C) are respectively applied. A two-component underwater curable epoxy resin composition (II) as a main component of the liquid is used to form an overcoat layer on the undercoat layer.

(A) Epoxy resin.

(B) A curing agent component that is highly hydrophilic.

(C) A hardener component that is highly hydrophobic.

[Action]

That is, the present inventors, as a result of a series of studies on the corrosion protection of the portion subjected to the hydraulic force as described above, when the epoxy resin composition is applied twice to the protected portion, compared to the case of once coating. It was found that the anticorrosion effect was dramatically improved. As a result of further research on this, a two-component underwater curable epoxy resin composition having a consistency of 30 to 300 was prepared as the first epoxy resin composition.
The high-viscosity putty that is set to the above is used, and the curing agent that is highly hydrophilic is used as the curing agent, and then the two-component underwater curable epoxy resin composition that uses the curing agent that is highly hydrophobic is applied. Then, they found that an excellent effect was obtained. That is, since the curing agent of the first two-pack type underwater-curable epoxy resin composition is rich in hydrophilicity, it can be well applied even to the corrosion-protected portion where hydraulic force acts, and since it is a high-viscosity putty, Good coating can be applied even to pits and irregular portions, and then a top coat layer is formed on the undercoat layer with a two-component underwater curable epoxy resin composition using a curing agent rich in hydrophobicity. It has been found that the undercoat layer is covered with the overcoat layer, and the epoxy resin composition containing a curing agent having a high hydrophilicity does not come into contact with water, so that long-term corrosion resistance is exhibited. did.

The anticorrosion construction method of the present invention comprises two types of underwater curable epoxy resin compositions, a two-pack type high-viscosity putty-like underwater curable epoxy resin composition (I) and a two-pack underwater curable epoxy resin composition (II). Used as underwater paint.

The two-pack type high-viscosity putty-like underwater-curable epoxy resin composition (I) contains a base compound containing the epoxy resin (A) as a main component and a hardener component (B) having high hydrophilicity as a main component. And a curing agent.

The epoxy resin as the component (A) means an epoxy resin alone or a mixed resin composed of the epoxy resin alone and another resin compatible with the epoxy resin.

As the above epoxy resin, a bisphenol type epoxy resin is suitable, but other cycloaliphatic epoxy resins,
Phenol or cresol novolak type epoxy resin, phthalic acid glycidyl ester type epoxy resin, β-
Examples thereof include methyl epichlorohydrin type epoxy resin, dimer acid type epoxy resin and polyglycol type epoxy resin. These epoxy resins may be used alone or in combination of two or more.
At this time, the epoxy resin is not particularly limited,
Usually, those having an epoxy equivalent of 70 to 1000, preferably 100 to 700 are used. Other resins compatible with the above epoxy resins include thermosetting resins and thermoplastic resins, and typical thermosetting resins include phenoxy resins, phenol resins, xylene resins, acrylic resins, unsaturated resins. Examples thereof include polyester resins, and examples of thermoplastic resins include polyester resins, ethylene-vinyl acetate copolymers, octycol resins, ionomer resins, modified butadiene-acrylonitrile resins, vinyl acetate resins, coal tar, asphalt pitch, and other coals. Examples include petroleum residual resins. One or two of these resins
One or more can be used with the epoxy resins described above. At this time, the other resin compatible with the epoxy resin can be used by replacing it in the range of 50% by weight (hereinafter abbreviated as "%") or less, preferably 30% or less of the epoxy resin used. In addition to the above-mentioned epoxy resin (A), other components are blended in the main component, if necessary. Other components include fillers such as calcium carbonate, silica, talc and perlite, and additives such as fine powder silica and fluidity regulators such as montmorillonite. The amount is usually 500 parts by weight or less, preferably 1 to 200 parts, relative to 100 parts by weight of the other main components (hereinafter abbreviated as "parts"). In particular, by using a large amount of filler, a high-viscosity base material can be obtained.

The (B) hydrophilic hydrophilic curing agent component is a main component of the curing agent that cures the base resin, and as an example thereof, polyamidoamine that is semi-soluble in water and has an affinity for water molecules is used. can give. Examples of the polyamidoamine include a condensation reaction component of a polymerized fatty acid such as dimer acid and trimer acid with a polyamine, particularly an aliphatic polyamine. In addition to the above-mentioned polyamidoamine, other amine-based curing agent components can be used in combination. Other hardener components include aliphatic polyamines,
Examples thereof include amine internal adducts, aromatic polyamines, polyalkylene polyamines, cycloaliphatic polyamines, modified polyamines, ketimine separation adducts, and the like. These amine-based curing agent components can be used in place of a part of the above polyamidoamine in the range of generally 40% or less, preferably 30% or less of the water-curable curing agent. The curing agent containing the curing agent component of (B) as a main component is capable of curing the main component containing the epoxy resin of (A) as a main component even in water, and other than the curing agent component of (B). Additives such as a filler and a fluidity adjusting agent which are mixed in the main component are mixed according to the purpose of use. These components are usually 500 parts or less, preferably 1 part, based on 110 parts of the curing agent component.
It is mixed at a ratio of up to 200 parts, and by using many fillers in particular, the curing agent can have a high viscosity.

The mixing ratio of the main component containing the (A) component epoxy resin as the main component and the (B) component containing the hydrophilic hardener component as the main component is such that the active hydrogen equivalent of the hardener component is epoxy. It is suitable to set 0.1 to 2 equivalents, preferably 0.5 to 1.5 equivalents, relative to 1 equivalent of epoxy resin. This is because if the active hydrogen equivalent of the curing agent component is less than 0.1 equivalent with respect to 1 equivalent of epoxy of the epoxy resin, the curing will be too slow, and if it exceeds 2 equivalent, the properties of the cured product will deteriorate.

In particular, the two-component underwater curable epoxy resin composition (I) comprising the main agent containing (A) as the main component and the curing agent containing (B) as the main component is composed of the main agent and the curing agent. It is important that the consistency after mixing (measured by the JIS-K-2220 method) is within the range of 30 to 300 at 23 ° C. By setting such a consistency, peeling due to hydraulic force such as water flow and waves does not occur, and the adhesiveness to recesses and pits becomes good, which is a major feature of the present invention. Particularly preferred is the above consistency of 50-25.
It is within the range of 0. That is, if the above-mentioned consistency is less than 30, the hardness of the two-component high-viscosity putty-like underwater-curable epoxy resin composition (I) will be too hard and the malleability will be poor, while if it exceeds 300, it will be soft. This is because it becomes too much and is easily peeled off before hardening due to the influence of hydraulic power such as water flow and waves.

A two-pack type underwater-curable epoxy resin composition (II) to be applied on the undercoat phase consisting of the above-mentioned high-viscosity putty-like underwater-curable epoxy resin composition (I) contains the epoxy resin of (A) as a main component. And a curing agent whose main component is the (C) curing agent component having high hydrophobicity.

The epoxy resin as the component (A), which is the main component of the base resin, is the same as the epoxy resin composition (I), or is a mixture of the epoxy resin alone or another resin compatible with the epoxy resin and the epoxy resin alone. It is a resin.

As the above epoxy resin, a bisphenol type epoxy resin is suitable, but other cycloaliphatic epoxy resins,
Phenol or cresol novolak type epoxy resin, phthalic acid glycidyl ester type epoxy resin, β-
Examples thereof include methyl epichlorohydrin type epoxy resin, dimer acid type epoxy resin and polyglycol type epoxy resin. These epoxy resins may be used alone or in combination of two or more.
At this time, the epoxy resin is not particularly limited,
Usually, those having an epoxy equivalent of 70 to 1000, preferably 100 to 700 are used. Other resins compatible with the epoxy resin include thermosetting resins and thermoplastic resins. Typical thermosetting resins include phenoxy resin, phenol resin, xylene resin, acrylic resin, unsaturated polyester. Examples of the thermoplastic resin include polyester resin, ethylene-vinyl acetate copolymer, thiochol resin, ionomer resin, modified butadiene-acrylonitrile resin, vinyl acetate resin, coal tar and asphalt pitchi coal, and petroleum. Residual resin etc. can be mentioned. Among these resins, one kind or two or more kinds can be used together with the above epoxy resin. At this time, the other resin compatible with the epoxy resin can be used by replacing it with 50% or less, preferably 30% or less of the epoxy resin used.

It should be noted that, in addition to the epoxy resin, other components are blended into the base resin as needed. Other components include fillers such as calcium carbonate, silica, talc, and pearlite, fine powder silica, and montmorillonite. Additives such as fluidity adjusting agents. These components are usually 500 parts or less with respect to 100 parts of the main component, preferably 1 to 200.
It is compounded in a ratio of parts, and a relatively high viscosity compounding system can be obtained by using a large amount of filler.

The curing agent that constitutes the above-mentioned two-component underwater curable epoxy resin composition (II) together with the above-mentioned main component is mainly composed of the curing agent component (C) which is rich in hydrophobicity. Additives such as the above-mentioned fillers and fluidity modifiers are appropriately blended according to the purpose of use. Other ingredients are 100
It is usually compounded in a ratio of 500 parts or less, preferably 1 to 200 parts with respect to parts, and by using a large amount of filler, a compounding system having a relatively high viscosity can be obtained.

Examples of the above-mentioned hydrophobic hardener component which is the main component of the hardener include hardeners for epoxy resins having an active hydrogen that is sparingly soluble in water and is replaceable with water molecules. Examples of these include aromatic amines, polyalkylene polyamines,
Examples thereof include cycloaliphatic polyamines, modified polyamines, amine curing agents for epoxy resins such as ketamine, polymercaptans, and the like, and one or more of these are used. In addition, a room temperature curable curing agent component usually used in the atmosphere can be used together with this type of curing agent component. Examples of the room temperature curable curing agent include an aliphatic polyamine, a polyamidoamine, an amine internal adduct, and a separation adduct. Etc. can be given. The room temperature curable curing agent is generally 40% or less of the curing agent component, preferably
It is used by replacing it within the range of 30% or less.

A main agent containing the above-mentioned (A) epoxy resin as a main component,
The mixing ratio of (C) with the curing agent containing the curing agent component having high hydrophobicity as a main component is such that the active hydrogen equivalent of the curing agent component is 0.2 to 2 equivalents relative to 1 equivalent of epoxy of the epoxy resin, preferably.
It is generally 0.5 to 1.5 equivalents. If this ratio is too small, the curing will be delayed, and if it is too large, the properties of the cured product will be deteriorated, which is not preferable.

As described above, the weakness of the undercoat layer can be reduced by applying the epoxy resin composition composed of the curing agent containing the water-insoluble curing agent that is hardly soluble in water as the main component and the main component containing the epoxy resin as the main component as the top coating composition. It is possible to cover and perform anticorrosion construction with excellent anticorrosion performance.

〔The invention's effect〕

As described above, the anticorrosion construction method of the present invention comprises a curing agent containing a hydrophilic curing agent component (B) as a main component and a main agent containing an epoxy resin (A) as a main component. A high-viscosity putty-like underwater-curable epoxy resin composition (I) having a consistency of 30 to 300 is used to form an undercoat layer on the work surface, so that the epoxy resin composition (I) is applied to the work surface. It adheres well to and spreads, and does not peel off even under the action of water flow. And in that state,
In order to coat the undercoat layer with the epoxy resin composition (II) using the curing agent component (C) having a high degree of hydrophobicity,
A relatively hydrophilic undercoat layer is coated and is immune to water. In this way, the properties of the above two epoxy resin compositions (I) and (II) are combined, and it becomes possible to realize corrosion resistant construction with high durability.

 Next, examples will be described.

First, prior to the Examples, a portion of a steel pipe sheet pile (diameter 600 mm) that was cast in the sea with severe pitting corrosion (pitting corrosion: a diameter of 50 mm or less and a depth of about 5 mm or less exist innumerable) from 2 m below sea level. The ground was adjusted to SIS-Sa2 1/2 by waterside blasting within a width of 4 m over 2 m above the sea. Then, anticorrosion construction shown in each of the following examples was performed on the construction-prepared surface.

[Example 1] The raw materials for the components shown in Table 1 were blended in the proportions shown in Table 1 for the undercoat layer and mixed on land to prepare an underwater curable epoxy resin composition (I) (mixture consistency 90). Next, this was coated by the wet hand method so that the average thickness was about 4 mm. Then, the underwater-curable composition (II) prepared by mixing the raw materials of the components shown in Table 2 for the overcoat layer on land was applied by brushing so that the average thickness was 300 μm.

[Examples 2 and 3] For the undercoat layer, the component raw materials shown in Table 1 were blended in the proportions shown in the same table and mixed on land to prepare an underwater curable epoxy resin composition (I) (mixture consistency: 220 and 15 respectively
0). Next, this was coated by the wet hand method so that the average thickness of each was about 4 mm.

Then, the underwater curable composition (II) prepared by mixing the raw materials for the components shown in Table 2 on land for the overcoat layer was applied with a brush so that the average thickness was 300 μm.

In all of the above examples, the workability during construction was good, and no abnormalities were observed in the observation results after 2.5 years, indicating good corrosion resistance. As described above, it is understood that the anticorrosion construction method of the present invention is a good construction method and exhibits good anticorrosion properties for a long period of time.

Claims (3)

(57) [Claims] 1. A two-pack underwater curable epoxy resin composition containing the following (A) and (B) as the main components of the respective liquids, which has a consistency of 30 to 300 at 23.degree. Two-component underwater curable composition containing (A) and (C) below as the main components of the respective liquids after forming an undercoat layer on the work surface with a viscosity putty-like underwater curable epoxy resin composition (I) An anticorrosion construction method comprising forming an overcoat layer on the undercoat layer with an epoxy resin composition (II). (A) Epoxy resin. (B) A curing agent component that is highly hydrophilic. (C) A hardener component that is highly hydrophobic. 2. The anticorrosion construction method according to claim 1, wherein the hydrophilic curing agent as the component (B) is polyamidoamine. 3. The component (C), which is rich in hydrophobicity, is at least one curing agent selected from the group consisting of aromatic amines, polyalkylene polyamines, cycloaliphatic polyamines, modified polyamines, ketamines and polymercaptans. The anticorrosion construction method according to claim 1, wherein