JPS62135519A - Underwater-curable epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition which can effectively protect an underwater structure or the like from corrosion and fouling, comprising a specified base resin, a curing agent for epoxy resin and a metal powder. CONSTITUTION:A base resin (A) of an epoxy equivalent <=3,000 is obtained by reacting 1 equivalent of the epoxy groups of an epoxy resin having at least one (un)substituted glycidyl ether group of the formula (wherein Z is H, methyl or ethyl) in the molecule and an epoxy equivalent of 200-1,000 with 0.025-0.5mol of an ester of an alcohol with a polyphenol-carboxylic acid having vicinal hydroxyl groups in the molecule (e.g., catechol-3-carboxylic acid) at 100-200 deg.C for 1-100hr. Component A is mixed with a curing agent (B) for epoxy resin in an amount to provide 0.5-2.5 equivalent of aminic active hydrogen per equivalent of the epoxy groups (e.g., aliphatic polyamine) and 5-75wt% powdered metal (C) (e.g., Zn) which has an ionization tendency larger than that of iron and has an average particle diameter of 1-300mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an underwater curable epoxy resin composition, and more particularly to a composition capable of preventing corrosion and staining of underwater structures, etc. .

(Conventional technology) Oil drilling or oil stockpile purging accompanying offshore development in recent years,
The construction and construction of steel structures such as offshore plant ships, piers of huge bridges built on the ocean, and underwater steel structures at offshore airports is increasing, but these require maintenance from the installation area. movement is almost impossible. Therefore, these sea tliW f! Problems such as anticorrosion coating, cleaning, and maintenance occur in underwater parts of structures or in splash zones, and the need for maintenance at sea has become a major issue. One way to solve this problem is to use the underwater parts of these underwater structures and SPLAY7.
It is conceivable to form a coating with excellent corrosion resistance on the shaft part using a simple and easy means similar to that used on land.

As such conventionally known compositions for underwater coating, there are compositions based on epoxy resin, using polyamide or polyamine as a hardening agent, and adding a filler thereto. However, this known composition has weak adhesion and is easily washed away due to JJL waves during curing, and even if it is cured, the adhesion of the cured product is insufficient and long-term corrosion protection is not expected at all. It is not possible.

The present inventors have made light of the above-mentioned drawbacks of conventional underwater coating compositions, and have found that they can be easily coated underwater by the same method as on land, and can also form coatings with excellent adhesion and high corrosion resistance. We have developed a composition for underwater painting and have continued to conduct intensive research to develop a method that can effectively protect underwater structures using this composition. We have succeeded in developing an excellent underwater curable epoxy resin composition and have already applied for a patent. This composition comprises: (a) a base resin obtained from an alcohol ester of a polyhydric phenol carboxylic acid having adjacent hydroxyl groups and an epoxy resin; composition).

In this prior application composition, epoxy I was used as the base resin.
By using A (fat) and at least one alcohol ester of polyhydric phenol carboxylic acid having adjacent hydroxyl groups (hereinafter referred to as alcohol ester), the original excellent coating performance and curability of epoxy resin can be maintained. In addition to this, the cooperative action of the phosphoric acid compound and the epoxy resin provides extremely excellent adhesion in water.

For this purpose, when the composition consisting of (a) and (b) above is applied, the adhesion force is extremely large, so it will not be washed away by waves or the like before curing, and will harden as it is, and the cured film will have good adhesive properties. Because of its large size, it firmly adheres to underwater structures. In addition, the cured coating film retains the original excellent properties of epoxy resin, so it has extremely excellent anti-corrosion properties and other properties.In the end, these features combine to provide excellent anti-corrosion results. This results in effective protection of underwater structures. It should be noted that the fact that the adhesion of epoxy resin in water can be significantly improved by using alcohol ester and epoxy resin together is a completely unknown and unknown fact, and as a result of many years of research by the present inventor. This is a surprising new fact that has just been discovered.

[Problem that the invention seeks to solve]

As the present inventor continues to further research on the above-mentioned underwater curable composition, it has become clear that when the composition of the prior application further contains a specific metal powder, it consists of this metal powder and the above (a) and 3). We have discovered that the anticorrosion performance of the scales can be further improved through a synergistic effect with the composition.

That is, the problem to be solved by the present invention is to solve the problems of conventional compositions of this type, and to further improve the anticorrosion performance of the composition of the prior application, which was able to solve the problems of conventional compositions of this type. That's true.

Means for solving problem c] This problem is solved by (a) and (a) used in the composition of the earlier application.
This is achieved by blending a metal powder with a greater ionization tendency than iron into the composition consisting of (b).

That is, the present invention provides (a) a base resin obtained from an alcohol ester of polyhydric phenol carboxylic acid having adjacent hydroxyl groups and an epoxy resin, (b) a curing agent for epoxy resin, and (c) a resin having a greater ionization tendency than iron. The present invention relates to an underwater curable epoxy resin composition characterized by containing a metal powder.

[Structure and operation of the invention]

In the present invention, by using a base resin obtained from an epoxy resin and an alcohol ester, the drawbacks of conventional compositions of this type can be overcome, and extremely excellent anticorrosion performance can be achieved. What should be noted in particular is that by using the base resin together with a metal powder that has a greater ionization tendency than iron, the synergistic effect of these two products further improves the anticorrosion performance. This will be explained in more detail as follows. That is, in the present invention, by using a predetermined combination of an epoxy resin, an alcohol ester, and a total bending powder whose ionization tendency is larger than that of iron, the original excellent coating performance of the epoxy resin is achieved through the cooperative action of the three. In addition to further increasing the adhesiveness, extremely strong adhesion in water is developed.

For this purpose, when the composition of the present invention is applied to underwater steel structures,
Because of its extremely high adhesive strength, it will not be washed away by waves or the like before it hardens, and will harden as it is, and the hardened coating will firmly adhere to underwater steel structures due to its high adhesive strength. In addition, the cured coating film has excellent properties that exceed those of epoxy resin, so it has extremely excellent anti-corrosion properties and other properties.In the end, all of these features combine to provide an extremely excellent anti-corrosion effect, allowing it to be used underwater. This effectively protects the structure.

The base resin used in the present invention is obtained from an epoxy resin and an alcohol ester.

The manufacturing method for this base + 1 fat is as follows.

First, to explain the blending ratio of both raw materials, epoxy resin and alcohol ester, the blending ratio of both is in principle such that the epoxy group remains, and usually the ratio of alcohol ester to 1 equivalent of epoxy group in the epoxy resin is such that the epoxy group remains. The blending ratio is 0.025 to 0.5 mol. In addition, the blending ratio is preferably such that an average of 0.05 mol or more, preferably 0.001 mol or more, of alcohol ester is reacted and contained per 1 mol of the product obtained by heat treatment from both of them, and furthermore, the above-mentioned product It is preferable to set the blending ratio so that the epoxy equivalent of is 3000 or less.

Both raw materials blended in the above-mentioned predetermined proportions are heat-treated in the presence or absence of a solvent, optionally in the presence of a catalyst, to produce a base) H fat. The heating temperature at this time is usually 10
The temperature is about 0 to 200°C, preferably about 130 to 165°C, and the heating time is usually 1 to 100 hours, preferably 7 to 65 hours.
It takes about an hour.

Catalysts that may be used as necessary include, for example,
Tertiary amines such as dimethylbenzylamine, methylbenzylmethylamine, triethylamine, triethanolamine, 2-dimethylamino-2-hydroxypropane; tertiary amines such as tetramethylammonium chloride, trimethylmonoethylammonium chloride, tetramethylammonium fluoride; Examples include amine hydrochlorides such as quaternary ammonium salts, quaternary phosphonium salts such as tetramethylphosphonium iodide, tetramethylphosphonium bromide, tetramethylphosphonium chloride, and trimethylmonoethylphosphonium chloride. Examples of solvents include cyclohexanone, methyl cellosolve, butyl cellosolve,
Typical examples include cellosolve acetate and cellosolve, which are usually used in an amount of 10 to 50% by weight.

The epoxy resin used as a raw material for the base resin in the present invention has a substituted or unsubstituted glycidyl ether group represented by the following formula % (where Z represents a hydrogen atom, a methyl group, or an ethyl group) in the molecule. Typical examples include diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, phenol novolac epoxy 411 fat, diglycidyl ether of alkylene oxide adducts of bisphenols, etc. There is no particular restriction on the epoxy equivalent, but preferably an epoxy equivalent of about 200 to 1,000.

The alcohol ester used in the present invention, more specifically the alcohol ester of polyhydric phenol carboxylic acid having adjacent hydroxyl groups in the molecule, is an ester of the above polyhydric phenol carboxylic acid and alcohol, preferably the above polyhydric phenol carboxylic acid. It is an ester of carboxylic acid and polyhydric alcohol. The polyhydric phenol carboxylic acid having adjacent hydroxyl groups used here has a carboxyl group of 1 (
Those having IIa or higher are used, such as catechol-3-carboxylic acid, catechol-4-carboxylic acid (protocatechuil), gallic acid (3,4,5-trioxybenzoic acid), m-digallic acid, pyrogallol-4 Preferred examples include -carboxylic acid, pyrogallol-4,6-dicarboxylic acid, tannic acid, etc.As the polyhydric phenol carboxylic acid, it is essential to use one having adjacent hydroxyl groups, and non-adjacent hydroxyl groups. A polyhydric phenol carboxylic acid having a polyhydric phenol carboxylic acid is undesirable because its adhesion in water decreases.The hydroxyl groups present in the polyhydric phenol carboxylic acid are mainly consumed in the reaction with the epoxy resin, and the carboxyl group becomes an ester with an alcohol. It is necessary for.

Furthermore, although a monohydric alcohol can be used as the alcohol used to form the ester, a polyhydric alcohol having a dihydrity or more is preferable. Specific examples include aliphatic monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol, diols such as ethylene glycol, propylene glycol, butyl alcohol, and 1,6-hexanediol, and triols such as glycerin and trimethylolpropane. , pentaerythritol, sorbitol, glycose, and other polyols having a valence of 4 or more.

The ester reaction between a polyhydric phenol carboxylic acid having adjacent hydroxyl groups and an alcohol can be carried out according to a conventional method, and the typical structure of the ester produced in this way is as follows:
For example, the case of ester of glycerin and protocatechuic acid is as follows.

H However, it is thought that other higher-order condensates are also included.

As the curing agent used in the present invention, those having N/8 property in water and displacing water molecules can be used, such as aliphatic amines, aromatic amines, alicyclic amines,
Examples include polyamides, amine-modified amides, ketimine, and the like. These curing agents can be used alone or in combination of two or more, and together with this underwater curing agent, a room temperature curing agent that is normally used in the atmosphere can also be used. Examples include group polyamines, polyamidoamines, amine-containing adducts, and separated adducts. The amount of these curing agents used is also sufficient as the amount used as a normal curing agent, and the active hydrogen equivalent of the amine group is usually about 0.5 to 2.5 equivalents per equivalent of the epoxy group.

Next, as metal powders having a larger ionization tendency than iron used in the present invention, zinc powder, aluminum powder, magnesium powder, chromium powder, zirconium powder, alloy powders of these powders, and composites made by coating or vapor depositing the above metals are used. There are powders, and one or more of them may be used. Among these, particularly preferred are zinc powder and aluminum powder. The average particle size of the powder is 1 to 3.
A range of 00 μm is preferable, and if it is less than 1 μm, the effect on improving underwater adhesion is not sufficient (and if it exceeds 300 μm, the appearance of the coating will deteriorate and is therefore unsuitable. The shape of the powder is flat or spherical. , needle-like, etc., the effect on improving underwater adhesion is the same, and either type is acceptable.The amount of these metal powders to be added is based on the base resin, curing agent, and metal powder as the main components. It is added in the range of 5 to 75% by weight of the epoxy resin composition.If it is less than 5% by weight, it will not have a sufficient effect on improving underwater adhesion, and if it is added in an amount exceeding 75%, it will reduce the cohesive strength of the composition and the steel. This is far from preferable since the adhesion to the substrate is reduced.

The metal powder may be mixed in advance into either or both of a blending system containing an epoxy resin as a main component, a blending system containing an underwater curing agent as a main component for curing an epoxy resin, or an epoxy resin. Fa may be added when mixing a blend system containing a resin as a main component and a blend system containing an underwater curing agent as a main component.

In addition, in the present invention, fillers can be used together,
The use of this filler improves underwater workability by adjusting viscosity and specific gravity, prevents peeling of the paint film due to coloration of waves, adjusts and makes uniform the thickness of the paint film, improves leveling, improves the mechanical strength of the cured product, and relieves stress. Effects such as these can be expected. This filler may be mixed in advance with the helium resin or the curing agent, or the base resin, curing agent, and filler may be mixed simultaneously.

A wide variety of filling materials are used at this time, including common materials such as calcium carbonate, curk, clay, heretonite, carbon black, and white carbon. It is used in an amount of 1 to 300 parts by weight based on 100 parts by weight of the total amount of agents.

The composition of the present invention can be filled with other epoxy resins and used in combination with various other additives, if necessary. Examples of additives in this case include diluents, solvents, coloring pigments, antirust pigments, etc. can be cited as a specific example.

Among the curing agents for epoxy resins used in the present invention, the average number of primary or secondary amine groups per molecule is 1.7 (I
Particularly preferred is a curing agent whose main component is a polyamide amine having a hardness of 11 or more. By using this hardening agent,
Furthermore, the adhesion is further improved and the anti-corrosion performance is improved. This polyamide amine has one primary to secondary amino group.
It has an average of 1.7 il1 or more per molecule, and those having an amide valency of 80 to 400 are generally used. Examples of this include polymerized fatty acids such as dimer acid and trimer acid obtained by polymerizing fatty acids having unsaturated bonds in the molecule such as lyluic acid, oleic acid, linoleic acid, elaidic acid, and phosphorus acid, and polyamines; Particular mention may be made of condensation reaction products with aliphatic polyamines.

The most typical polyamide amine is a condensation reaction product of dimer acid or trimer acid of riluic acid and polyamine.

Its structure is as follows when, for example, dimer acid of riluic acid is used as a raw material.

(C1h)t CNHR (C)+2 )r ■ H3 (In the formula, R and R' are residues of polyamine, and they may be the same or different.) Using the composition of the present invention, To protect the structure, the composition of the invention is applied to the submerged or splashed parts of the underwater structure. As the coating means at this time, any of the same means as used on land can be effectively applied, such as brush coating, roll coating, spatula coating, mechanical coating, etc. 20 to 500 voids for brush or roller application, 50 for spatula application
It is preferable to set it to about 0 to 2000 poise.

〔Effect of the invention〕

In the present invention, an epoxy resin and an alcohol ester are used as the base resin (14), and a metal powder having a higher ionization tendency than iron is used in combination with the resin to achieve the excellent coating performance and hardenability inherent to the epoxy resin. is retained as is, and furthermore, due to the cooperative action of the above-mentioned alcohol ester, epoxy resin, and above-mentioned metal powder, extremely excellent adhesion in water is developed. For this reason, when the composition of the present invention is applied, it has extremely high adhesion, so it will not be washed away by waves before curing, and will harden as it is, and the cured film will have strong adhesion, so it will firmly adhere to underwater structures. do. In addition, the cured coating film retains the original excellent properties of epoxy resin, so it has extremely excellent anti-corrosion properties and other properties.In the end, all of these characteristics collectively demonstrate an extremely excellent anti-corrosion effect. This effectively protects underwater structures.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples. However, in the following examples, parts indicate parts by weight.

Example 1 Triester of protocatechuic acid in glycerin (molecule g
L500)' 20 parts, bisphenol A diglycidyl ether (epoxy fl190) 100 parts, ethyl cellosolve 60 parts and dimethylbenzylamine 0.15 parts as a catalyst were added and the reaction was carried out at 150°C for 7 days with stirring. A base resin (1) was obtained.

100 parts of the base resin, 40 parts of calcium carbonate, and 2 parts of colloidal silica were mixed at 50° C. in a stirring mixing pot to prepare an epoxy resin blended system.

On the other hand, 100 parts of aromatic modified polyamine (amine value 270, aromatic diamino diphenylmethane), 300 parts of zinc powder (average particle size 50 μm), and 20 parts of xylene were mixed in a stirring mixing pot at 50°C to prepare a curing agent compounded system. .

A two-component underwater curable epoxy resin composition was obtained by mixing this curing agent blend system and the above-mentioned epoxy resin blend system at a mixing ratio (weight ratio) of 1:1.

Using this composition, Sr1 was coated with a rubber spatula to a dry film thickness of 300 μm, and the initial adhesion, adhesion after curing, destruction rate, and rust occurrence were measured.

The results are shown in Table 1 below. However, the steel plate used was a steel plate that had been immersed in 3% common salt for one day immediately after shot blasting.

Example 2 150 parts of bisphenol A/diglycidyl ether (epoxy equivalent: 190), 50 parts of diglycidyl ether of bisphenol A/propylene oxide adduct (epoxy equivalent: 340), 50 parts of m-digallic acid ester of glycose, 100 parts of cellosolve acetate 1 part and 0.5 part of triethylamine as a catalyst, and 16 parts at 150'C.
A time reaction was performed to obtain a base resin (2).

100 parts of the base resin (2), 40 parts of calcium carbonate, and 2 parts of colloidal silica were mixed at 50° C. in a stirring mixing pot to prepare an epoxy 444 resin blended system.

On the other hand, the curing agent compounding system used was the same as the curing agent compounding system of Example 1, and the mixing ratio (weight ratio) of this curing agent compounding system and the above epoxy resin compounding system (2) was 1:1. Example 1 A two-component underwater curable epoxy resin composition
processed in the same way.

The results are shown in Table 1.

Example 3 150 parts of bisphenol F diglycidyl ether (tft240 per epoxy), 50 parts of pyrogallol-4-carboxylic acid diester of diethylene glycol, 100 parts of cyclohexanone, and 1 part of triethanolamine as a catalyst were added and heated at 135°C for 12 hours with stirring. The reaction was continued for several hours to obtain a base resin (3).

100 parts of the base resin (3), 40 parts of calcium carbonate,
and 2 parts of colloidal silica were mixed at 50° C. in a stirring mixing pot to prepare an epoxy resin blended system.

On the other hand, the curing agent compounding system used was the same as in Example 1,
The mixing ratio of this curing agent blend system and epoxy resin blend system (
A two-component underwater curable epoxy resin composition was obtained by setting the weight ratio to 1:1, and the same treatment as in Example 1 was carried out.

The results are shown in Table 1.

Comparative Example 1 100 parts of unmodified bisphenol A diglycidyl ether (TT190 per epoxy), 40 parts of calcium carbonate, 2 parts of colloidal silica, and 10 parts of xylene were mixed at 50°C in a stirring mixing pot to form an epoxy resin compound system. . On the other hand, the same curing agent compounding system as in Example 1 was used as the curing agent compounding system, and the mixing ratio (weight ratio) of this compounding system and the above-mentioned epoxy resin compounding system was 1:1, resulting in a two-part type. A water-curable epoxy resin composition was prepared, and the same treatment as in Example 1 was carried out. The results are shown in Table 1.

Comparative Example 2 100 parts of unmodified bisphenol A diglycidyl ether (epoxy equivalent: 190), 40 parts of calcium carbonate,
2 parts of colloidal silica and 10 parts of xylene were mixed at 50° C. in a stirring mixing pot to form an epoxy resin blended system.

On the other hand, 100 parts of aromatic modified polyamine (amine value 270, aromatic diamino diphenylmethane), 100 parts of calcium carbonate, and 20 parts of xylene were mixed at 50° C. in a stirring mixing pot to prepare a curing agent compounded system.

This blended system and the above-mentioned epoxy resin blended system were mixed at a mixing ratio (weight ratio) of 2:3 to obtain a two-component underwater curable epoxy resin composition, and treated in the same manner as in Example 1. The results are shown in Table 1.

Table 1.

However, the 1jllll formula for each physical property in Table 1 is as follows.

Steel plate: 9 x lO 100 x lOO Dull steel plate Coating method: After soaking the above steel plate for a predetermined time, the composition was applied with a rubber spatula while the steel plate was crushed, and then cured.

Initial adhesion: Umeko workability when applying with a rubber spatula (
The quality of adhesion was observed, and the following evaluation was performed.

○・・・Good (it sticks just by applying it with a rubber spatula) △・・・・・・Possible (it sticks when you touch the rubber with your hand a few times) ×・・・Poor (does not stick) ) After 6 months of hardening, the immersed paint sample was taken out into the atmosphere (23'C165%R11) and after 1 day (
& The coating film was cut with a force and a tar, and a measurement dolly was adhered using an adhesive, and the applied Yt force was measured with an adhesion tester.

Cohesive failure rate: A polyethylene film with a uniform thickness was placed on the measurement area, and the part of the paint film that was destroyed by 4M was removed with a magic marker, the weight was measured, and the U-cohesive failure rate was calculated using the following formula. .

Cohesive failure rate = X100 (%) where m is the entire measurement area, ml is roundabout failure! Indicates the part that was pressed.

The presence or absence of rust was determined by visually observing the two surfaces where rust had developed.

(that's all)

Claims (3)

[Claims] (1) (a) Base resin obtained from an alcohol ester of a polyhydric phenol carboxylic acid having adjacent hydroxyl groups and an epoxy resin, (b) a curing agent for epoxy resin, and (c) a metal powder with a greater ionization tendency than iron. An underwater curable epoxy resin composition comprising: (2) The amount of metal powder in the epoxy resin composition is 5 to 75%
% by weight of the underwater curable epoxy resin composition according to claim 1. (3) The underwater curable epoxy resin composition according to claim 1 or 2, wherein the metal powder is zinc powder or aluminum powder.