JPS62135517A - 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 0.05-0.9 equivalent of the hydroxyl groups of a phosphoric acid having at least one P-OH bond or its ester or salt (e.g., orthophosphoric acid) at 50-130 deg.C. 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., Zn) which has an ionization tendency larger than that of iron and has an average particle diameter of 1-300mum and 1-30pts.wt., per 100pts. wt. total of components A and B, filler (D) (e.g., CaCO3).

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 that can effectively prevent corrosion and staining of underwater structures.

[Conventional technology]

Oil drilling or oil stockpile purging associated with 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, problems such as anticorrosive coating, cleaning, maintenance, etc. occur in the underwater part of these marine steel structures or in the splash zone, and the need for maintenance at sea has become a major issue. As one means to solve this problem,
It is conceivable to form a coating with excellent anticorrosion properties on the underwater parts and splash zone parts of these underwater structures using simple and easy means similar to those on land.

As a conventionally known composition for underwater painting, there is a composition in which an epoxy resin is used as a base, a polyamide or a polyamine is used as a hardening agent, and a filler is added thereto. However, this known composition has weak adhesion and is easily washed away by 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 inventor focused on the above-mentioned drawbacks of conventional underwater coating compositions, and developed an underwater coating that can be easily coated underwater by the same operation as on land, and can form a coating with excellent adhesion and high corrosion resistance. We have been conducting intensive research to develop a composition for water treatment and, in turn, to develop a method that can effectively protect underwater structures using this composition. We have successfully developed a water-curable epoxy resin composition and have already applied for a patent. This composition comprises: (a) phosphoric acid having at least one P-OH bond;
This is a composition (hereinafter referred to as the composition of the prior application) containing a base resin obtained from at least one of the esters and salts thereof and an epoxy resin, and (b) a curing agent for epoxy resins.

In this prior application composition, an epoxy resin as a base resin, phosphoric acid having at least one P-011 bond,
Its ester and its salt (hereinafter referred to as phosphoric acid compound)
By using at least one type of epoxy resin, the original excellent coating performance and curability of the epoxy resin can be maintained as is, and furthermore, due to the cooperative action of the above-mentioned phosphoric acid compound and the epoxy resin, it can be made to have extremely excellent underwater properties. Adhesion is developed. For this purpose, when a composition consisting of (a) and (b) above is applied, it has extremely high adhesion, so it will not be washed away by waves etc. before curing, and will cure as it is, and the cured film will have high adhesion. Therefore, 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, all of these characteristics combine to provide an extremely excellent anti-corrosion effect, making it ideal for underwater use. This results in effective protection of the construct. It should be noted that the fact that the adhesion of epoxy resin in water can be significantly improved by using a phosphoric acid compound and epoxy resin in combination is a completely unknown and unknown fact, and the present inventors have been researching for many years. This is a surprising new fact discovered for the first time.

[Problem that the invention seeks to solve]

While continuing research on the above-mentioned underwater curable composition, the present inventor found that when the composition of the prior application further contains a specific metal powder, a composition consisting of this metal powder and the above (a) and (b) We have discovered that scales can further improve anti-corrosion performance through a synergistic effect with other substances.

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 problems]

This problem was solved in (a) and (a) used in the composition of the earlier application.
This is achieved by blending a metal powder with a higher ionization direction than iron into the composition consisting of (b).

That is, the present invention provides: (a) at least 1 of phosphoric acid having at least 1llil P-011 bond, an ester thereof and a salt thereof (a base resin obtained from a cup and an epoxy resin; (b) a curing agent for epoxy resin; and (b) a curing agent for epoxy resin. c) A metal powder whose ionization direction is larger than that of iron.

(Structure and operation of the invention) In the present invention, by using a base resin obtained from an epoxy sealant and a phosphoric acid compound, the drawbacks of conventional compositions of this type can be overcome, and extremely excellent corrosion protection can be achieved. Demonstrate performance. 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. In the beating process of the present invention, by jointly using a predetermined amount of an epoxy resin, a phosphoric acid compound, and a metal powder whose ionization tendency is larger than that of iron, the cooperative action of the three allows the original excellent /i Membrane 1
In addition to further increasing the strength of the product, it also develops extremely strong underwater adhesion. For this reason, when the composition of the present invention is applied to underwater steel structures, it has extremely high adhesion, so it will not be washed away by waves before it hardens, and will harden as it is, and the cured film will have a high adhesion. Strongly adheres to underwater steel structures. 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 a phosphoric acid compound, and these two raw materials are usually mixed in proportions such that the epoxy resin remains, and each equivalent of epoxy groups in the epoxy resin is mixed. On the other hand, the hydroxyl group of the phosphoric acid compound is equivalent to 0.05 to 09 g, preferably 0.05 to 0.4
They are mixed in equivalent amounts and heated. The heating temperature at this time is usually about 50 to 130°C, preferably about 80 to 110°C. Although a solvent is not necessarily required in this reaction, the reaction may be carried out in the presence of a solvent. Representative examples of the solvent in this case include toluene, xylene, styrene, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, etc.
The amount of these solvents used is usually about 10 to 100 parts by weight per 100 parts by weight of the base resin. The base resin thus obtained has an epoxy equivalent of 3000 or less, preferably about 190 to 2000.

The epoxy resin used as a raw material for the base resin in the present invention has at least 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 its molecule. For example, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, phenol novolac epoxy resin, diglyndyl ether of alkylene oxide adducts of bisphenols, etc. can be used. The equivalent is not particularly limited, but preferably has an epoxy equivalent of about 200 to 1,000.

The phosphoric acid compounds used in the present invention are small (
Both are phosphoric acid, its ester, or its salt having one P-Of (bond; examples of phosphoric acid include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, polyphosphoric acid, phosphonic acid, phosphinic acid, etc.) Among them, orthophosphoric acid is particularly preferred.

Examples of phosphoric acid esters include the above-mentioned phosphoric acid esters, preferably alkyl esters having about 8 or less carbon atoms (those having one or more hydroxyl groups) and hydroxyalkyl esters, such as ethyl, n-butyl, 2- Examples thereof include those having groups such as ethylhexyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, and hydroxypentyl, and mono- or di-phosphate esters of n-butyl or 2-ethylhexyl are particularly preferred.

Examples of the salts of phosphoric acid include salts of the above-mentioned phosphoric acids, such as salts of potassium, sodium, lithium, calcium, zinc, aluminum, tin, barium, etc. Diphosphate is preferred.

As the curing agent used in the present invention, those that are generally poorly soluble in water and have the ability to replace water molecules can be used, such as aliphatic amines, aromatic amines, alicyclic amines, polyamides, Examples include amine-modified amides and ketimine. These curing agents are used singly or in combination of two or more,
In addition, a room temperature curing agent that is normally used in the atmosphere can be used together with this underwater curing agent. Examples of these curing agents include aliphatic polyamine, polyamide amine,
Examples include 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 amount of active hydrogen equivalent of amino group is usually about 0.5 to 2.5 equivalents per equivalent of epoxy group.

Next, the metal powders that have a greater ionization tendency than iron used in the present invention include zinc powder, aluminum powder, magnesium powder, chromium powder, zirconium powder, alloy powders of these powders, and composites plated or vapor-deposited with the above metals. 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 171 m, the effect of improving underwater adhesion is not sufficient, and if it exceeds 300 μm, the appearance of the coating film will deteriorate, so it is inappropriate. The shape of the powder may be flat, spherical, acicular, etc., as the effect on improving underwater adhesion is the same, and any shape may be used. The amount of these metal powders added is in the range of 5 to 75% by weight of the epoxy resin composition whose main components are a base resin, a curing agent, and a metal powder. If the amount is less than 5% by weight, there will be no sufficient effect on improving underwater adhesion, and if it exceeds 75% by weight, the cohesive force of the composition and the adhesion to the steel base will decrease, so it cannot be said to be preferable.

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. It may be added when mixing a compound system containing a resin as a main component and a compound 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 the influence of waves, adjusts and makes the paint film uniform, 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 base resin or with the curing agent, or the base resin, curing agent, and filler may be mixed at the same time.

A wide variety of fillers are used at this time, and common examples include calcium carbonate, talc, clay, heretonite, carbon black, and white carbon. It is used in an amount of 1 to 300 parts by weight based on the total ffl l OO @ placement part.

Various other additives including other epoxy resins can be used in combination with the composition of the present invention, 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, curing agents whose main component is polyamide amine having an average of about 1.7 or more primary or secondary amino groups per molecule are particularly preferred. By using this hardening agent, the adhesion is further improved and the anticorrosion performance is improved. This polyamide amine has an average of about 1.7 or more primary or secondary amino groups per molecule, and generally has an amino acid value of 80
~400 are used. Examples of this include polymerized fatty acids such as dimer acid and trimer acid obtained by polymerizing fatty acids with unsaturated bonds in the molecule such as liluic acid, oleic acid, linoleic acid, elaidic acid, wasylic acid, etc., and polyamines. , in particular 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.

(CH2), -C-N HR (CH2) & CH3 (wherein R and R' are residues of polyamine, and may be the same or different) using the composition of the present invention. When protecting an underwater structure, the composition of the present invention is applied to the underwater part or the suspension part 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. It is best to use 20 to 500 poise when applying with a brush or roller, and about 500 to 2000 poise when applying with a spatula.

〔Effect of the invention〕

In the present invention, an epoxy resin and a phosphoric acid compound are used as the base resin, and a metal powder having a greater ionization tendency than iron is used in combination with the base resin, thereby achieving the excellent coating film performance and hardenability inherent to the epoxy resin. In addition to maintaining the adhesive as it is, extremely excellent adhesion in water is developed due to the cooperative action of the phosphoric acid compound, epoxy resin, and metal powder. For this reason, when the composition of the present invention is applied, the adhesive strength is extremely high, so it will not flow out due to waves or the like before curing, and will harden as it is, and the cured film will have high adhesiveness, so it will firmly form underwater structures. closely adhere to. 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. This results in effective protection of underwater structures.

[Example] The present invention will be specifically explained with reference to Examples below. However, in the following examples, parts indicate parts by weight.

Example 1 100 parts of bisphenol A diglycidyl ether (t1260 per epoxy), 25 parts of alkyl (carbon number 18) monoglycidyl ether (epoxy equivalent 330), 6 parts of orthophosphoric acid and 50 parts of xyleno were mixed and heated at 80°C.
A time reaction was performed to obtain a base resin (1).

100 parts of the base resin (1), 40 parts of calcium carbonate,
Two parts of colloidal silica were mixed in a stirring pot at 50°C to form an epoxy resin compounded 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 kiln 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 prepared by setting the mixing ratio (weight ratio) of this curing agent blend system and the above-mentioned epoxy resin blend system to tit. This composition was applied to a steel plate with a rubber spatula to a dry film thickness of 300 μm, and the initial adhesion, adhesion after curing, fracture 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 Instead of using the aromatic modified polyamine alone as a curing agent in Practical Example 1, 20 parts of the 100 parts were an aliphatic polyamine (amine value 370, metaxylylene diamine, molecule 1250) The same procedure as in Example 1 was carried out in all other respects. The results are shown in Table 1.

Example 3 100 parts of bisphenol F diglycidyl ether (epoxy equivalent 280), 50 parts diglycidyl ether of bisphenol A propylene oxide adduct (epoxy equivalent 340), 17 parts dibasic potassium phosphate, and 50 parts xylene were mixed. A stirring reaction was carried out at 110° C. for 5 hours to obtain a base resin (n).

100 parts of this base resin (II), 40 parts of calcium carbonate
1 part and 2 parts of colloidal silica were mixed in a stirring pot at 50°C,
It is an epoxy resin compound 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 (epoxy FF1190), 40 parts of calcium carbonate
1 part, 2 parts of colloidal silica, and 10 parts of xylene were mixed at 50° C. in a stirring mixing pot to prepare 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 (3ill ratio) of this compounding system and the epoxy resin compounding system was set to 1; A water-curable Evoquin 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.

Meanwhile, 100 ffB of aromatic modified polyamine (amine value 270, aromatic diamino diphenylmethane), 100 parts of calcium carbonate, and 20 parts of xylene were stirred in a kettle at 50°C.
The mixture was mixed to form a curing agent compound 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 standard method for each physical property in Table 1 is as follows.

Steel plate: 9 x 100 x 100 mm Dull steel treatment Coating method 2 After immersing the above-mentioned steel for a predetermined time/2, the composition was applied with a rubber spatula while it was still immersed and cured.

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

O: Good (adheres just by applying with a rubber spatula) △: Possible (adheses when applied with a rubber spatula a few times) ×: Poor (does not adhere) Cured Adhesion strength after = 6 months 1 & Take out the immersed paint sample in the atmosphere (23℃, 65% RH), cut the paint film after 1 day with a cutter, adhere it to a measuring dolly using adhesive, Adhesion force was measured using an adhesion tester.

Cohesive failure rate: A polyethylene film of uniform thickness was placed on the measurement site, the part of the coating film that had cohesively failed was removed with a magic marker, the weight was measured, and the cohesive failure rate was calculated using the following formula.

Cohesive failure rate--X I OO (%) where m indicates the entire measurement area, and ml indicates the cohesive failure area.

Occurrence of rust: The presence or absence of rust was examined by visually observing the surface.

(that's all)

Claims (3)

[Claims] (1) (a) A base resin obtained from an epoxy resin and at least one of phosphoric acid having at least one P-OH bond, an ester thereof, and a salt thereof, (b) a curing agent for epoxy resin, and (c) A water-curable epoxy resin composition comprising a metal powder having a greater ionization tendency than iron. (2) The amount of metal powder in the epoxy resin composition is 5 to 75%
The underwater curable epoxy resin composition according to claim 1 or 2, which is % by weight. (3) The underwater curable epoxy resin composition according to claim 1 or 2, wherein the metal powder is zinc powder or aluminum powder.