JPH0229479A - Underwater coating epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in the ability to wet a substrate and adhesion thereto and being applicable to an underwater or wet surface by adding an amide compound having two specified groups to a resin composition comprising an epoxy compound and a room temperature curing agent. CONSTITUTION:The title resin composition is one formed by adding a room temperature curing agent as a vehicle to an epoxy compound containing at least one epoxy group in the molecule, wherein an amide compound having at least 0.2 carboxyl group and at least 0.2 imidazoline ring in the molecule [e.g., a compound of the formula (wherein R<1> and R<2> are each an organic group; l is an integer >= 2, and m is a positive number <= 1] is added. According to the above, the carboxyl groups of the amide compound exhibit an affinity stronger for the substrate than for water, and so displaces water, and the displaced water molecules are excluded by the hydrophobic part of the molecule. Further, the imidazoline rings can exhibit a dehydrative action, and the water can be completely excluded. Further, the active hydrogen atoms of the sec. amino groups formed as a result of the hydrolysis of the imidazoline rings react with the epoxy resin to integrate the amide compound with the epoxy resin and markedly improve the adhesiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an underwater coating type epoxy resin composition that can be coated underwater or on wet surfaces.

(Conventional technology) Built on beaches, underwater, rivers, lakes, etc., where it is constantly wet or
Epoxy resins and unsaturated resins have traditionally been used as resin compositions that can be applied to the underwater or wet surfaces of submerged SWI structures such as steel sheet pile revetments, steel pipe piles of port facilities, bridge piers, dam gates, and water gates. Resin compositions of this type are known.

(Problem to be solved by the invention) However, when applying these conventional resin compositions to a wet surface using a brush, roller, trowel, etc., if the adhesion is not sufficient, it is necessary to repeat the application operation many times. Moreover, the coating film peels off due to waves and water currents, reducing coating efficiency.

Further, even if the coating properties are good, if the adhesiveness of the cured coating film is low, the anticorrosion effect cannot be exhibited for a long period of time.

As described above, conventional resin compositions have had problems in terms of construction efficiency and durability.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an underwater coating type epoxy resin composition that improves the applicability and adhesion to wet surfaces of the cram school composition and also improves the economic efficiency of the underwater anticorrosion coating method.

(Means for Solving the Problems) A feature of the present invention is that an amide compound containing 0.2 or more carboxyl groups and 0.2 or more imidazoline rings in the molecule is added to the resin composition. It is in.

This amide compound is a carboxylic acid compound that has a 1.
The reaction is carried out at a ratio of 2 equivalents or more at a temperature of 100° C. to 250° C. under dehydration conditions.

When polyethylene polyamine and polycarboxylic acid having a valence of 2 or more are allowed to react, they may become polymerized and, in severe cases, gelation may occur, so care must be taken. In order to prevent this problem, one of the primary amine groups of the polyethylene polyamine is reacted with a monovalent carboxylic acid compound at an equivalent ratio of primary amine to carboxylic acid of, for example, 2:1. Depending on the desired amount of carboxyl groups to remain with the polycarboxylic acid after amidation (and may further form an imidazoline ring), the above-mentioned amidated product (imidazoline cyclized product) can be reacted with the polycarboxylic acid in a predetermined manner.

The above reaction steps can be expressed as model formulas as shown in Formula-1 and Formula-2, and if the dehydration is continued, product 4 of Formula-1 and Formula-12 will ultimately be obtained.

2-2 Examples of the polyethylenediamine used for producing this amide compound include diethylenediaminetriamine, triethylenediaminetetramine, tetraethylenediaminepentamine, pentaethylenediaminehexamine, etc. Furthermore, adduct modified products of these with epoxy compounds,
A Michael reaction modified product or a Mannich reaction modified product may also be used.

The monovalent carboxylic acids used to produce this amide compound include saturated or unsaturated carboxylic acids having 2 or more carbon atoms.
Examples of polycarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, maleic acid, hunuric acid, itaconic acid, dimer acid, trimer acid, and isocyanate polymers of castor oil fatty acids.

Carboxylated terminal hydroxyl groups of polyoxyalkylene compounds, (meth)acrylic acid copolymers, maleic acid copolymers, polyester polycarboxylic acids.

Examples include aminopolycarboxylic acids and the like.

Note that aromatic carboxylic acids such as benzoic acid, phthalic acid, and trimellitic acid may be used in combination.

This amide compound has an imidazoline ring and a carboxyl group of 0,0001 to 0,000, respectively, in 100 g of the resin composition.
It is added in an amount of 0.01 mol, but preferably in a range of o, ooos to o, oos mol. This is because if each amount is less than 0.0001 mol, the effect of the present invention is hardly achieved, and if each amount is 0.0001 mol or more, the water resistance decreases, which is not preferable.

In addition, the number of carboxyl groups and imidazoline rings contained in this amide compound Th1 molecule does not necessarily have to be the same, or it is necessary that they each contain 0.2 or more, and preferably 0.5 or more. More preferred.

The reason for this is that if the number of each amide compound is 0.2 or less, it is necessary to incorporate a large amount of this amide compound in order to exhibit the effect of the present invention, which may cause problems such as a decrease in water resistance and a decrease in curing speed. This is because it is undesirable.

The epoxy resin serving as the base of the present invention is preferably one that can be liquefied at room temperature, has an epoxy equivalent of about 70 to 1,000, and has an average of 1.5 or more epoxy groups in one molecule, such as bisphenol A, bisphenol F, etc. Examples thereof include diglycidyl ethers such as diglycidyl ethers such as formalin initial condensates of phenol compounds, and polyglycidyl esters of polycarboxylic acids such as phthalic acid and adipic acid.

As curing agents for epoxy resins, aliphatic amines, alicyclic amines, aromatic amines, or amide-modified products, adduct-modified products, Mannich reaction-modified products, Migel reaction-modified products, carbonyl-modified products, etc. A mixture of these may be used if necessary.

Other components of the resin composition of the present invention include talc, mica, flake, kaolin, and 'aB barium.

Extending pigments such as calcium carbonate, alumina, zinc white, silica powder, white titanium, yellow lead, valve rind, yellow iron oxide, organic world,
Coloring pigments such as organic yellow, organic blue, organic edge, etc.; anticorrosive pigments such as chromic acid, molybdic acid, phosphoric acid, boric acid, ferrite, lead acid, etc.

Metal powders such as stainless steel powder, zinc powder, and aluminum powder; scaly pigments such as glass flakes, stainless steel flakes, aluminum flakes, and plastic flakes.

By appropriately selecting fibrous materials such as asbestos/wire fibers, glass fibers, carbon fibers, and synthetic fibers, as well as additives such as silane coupling agents, sedimentation/sagging prevention agents, and surfactants, we can achieve the desired two-hue coating. Mfi suitable viscosity etc.
can do.

The resin composition of the present invention can be applied underwater or to a wet surface with a brush, roller, spatula, trowel, etc.
When cured, it exhibits excellent adhesion and can provide excellent anticorrosion effects over a long period of time.

(Function) The first stage of the action of the present invention is that the carboxyl group contained in this amide compound exhibits a stronger affinity for the surface to be coated than water and displaces water, resulting in water-repellent properties. The molecular skeleton excludes water. Therefore, the water-based epoxy resin can approach the coated surface at a distance where it can exhibit adhesive activity.

However, it is difficult to completely eliminate water that is submerged or covers wet surfaces, so the second step of the action of the present invention is to
The imidazoline ring dehydration effect of this amide compound is exerted,
Water is more completely eliminated.

This action is caused by the well-known reaction shown in Equation-3.

Formula-3 The third step of the action of the present invention is that the active hydrogen possessed by the secondary amino group generated by the hydrolysis reaction of the imidazoline ring reacts with the epoxy resin, so that the amide compound and the epoxy resin can be integrated. .

This allows the amide compound to function as a coupling agent, and also prevents problems that occur when a low molecular weight compound is added.

(Effect of the invention) In this way, the carboxyl group of the amide compound.

The imidazoline ring can synergistically improve the wettability and adhesion of the epoxy resin to the coated surface through its exquisite action.

This effect is found in carboxyl group-containing compounds.

This is superior to the case where each imidazoline ring-containing compound is used alone or simply as a mixture.

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

Examples 1 to 5 Comparative Example 1 Epoxy resin (manufactured by Shell Chemical Co., Ltd., trade name Epicoat 82
8. Bisphenol A type epoxy resin) as the main ingredient and modified polyamine (manufactured by Asahi Denka, trade name: ADEKA HARDNER EH)
-229> as a curing agent, the results shown in Attached Table-1 were obtained. (The compounding composition indicates parts by weight.) The mixing and kneading method, preparation of the coating material, testing method, and evaluation method are as follows.

Mixing and kneading method Preparation of 23-roll paint: Immediately before use, thoroughly mix the proportions indicated by the small measurements of each component.

Test method: A 70x 15x 2.3nn sandblasted annealed copper plate was immersed in seawater for 30 minutes.
The coating was left with rust, sea bacteria, etc., and then the resin composition prepared in the manner described above was fixed vertically. Apply it on the iron plate above using a rubber spatula in seawater,
It was cured and cured in seawater for 7 days and used to measure adhesive strength.

Evaluation method: When applying using a rubber spatula, evaluation was given as ◯ if the coating could be easily applied in one reciprocation, ∆ if the application could be applied in 2 to 5 reciprocations, and × if the application could not be applied more than that or at all. Adhesive strength was measured using an adhesion tester (manufactured by Elcometer) by adhering a jig to the surface with an epoxy resin adhesive and measuring three points on the test plate surface, and the average value is shown.

Amide compound A used in Examples 1 and 2 was synthesized as follows.

capryl il 144. and diethylenetriamine 103
g was charged into a reactor, 50 g of Quijirole was added thereto, and the mixture was reacted at 150 to 160°C for 3 hours under ring distillation of Quijirole to obtain a Quijirole:/lj liquid of amide compound intermediate 280. I got it. 150g of ethylenediaminetetraacetic acid for this intermediate
Add 1/2 mole, 20-3011 at 190-200℃
The reaction was further carried out for 3 hours while 8 g of Quijirol was distilled off under reduced pressure, and then 100 g of ethyl cellosolve was added to obtain amide compound A (non-volatile content: 77%).

Amide compound B used in Example 3 was synthesized as follows.

144g of caprylic acid and 150g of triethylenetetramine
was charged into the reactor, and 50. was added thereto and reacted for 3 hours at 150 to 160°C under ring distillation of Quijirol to obtain 320 f of Quijirole solution of an intermediate of the amide compound.

To this intermediate, 150 g of hexane-1,6-cythiodisuccinic acid was added and reacted in the same manner as in the case of amide compound A, and then 100 g of butyl cellosolve was added to obtain amide compound B (non-volatile content: 80%).

Amide compound C used in Example-4 was synthesized as follows.

350g of soybean oil fatty acid and 100g of diethylenetriamine
was charged into a reactor, 50 g of quijirole was added, and the mixture was reacted in the same manner as amide compounds A and B to obtain an amide compound intermediate.

To this intermediate, 75° of nitrilotriacetic acid was further added and reacted in the same manner as amide compounds A and B, diluted with butyl cellosolve, and 500 g of amide compound C (non-volatile content: 8
0%) was obtained.

The amide compound used in Example-5 was synthesized as follows.

To 280 g of the same intermediate used in the synthesis of amide compound A, 760 g of nitrilotriacetic acid and 130 g of octyl alcohol were added, and the cyclodistillation of quidylole was reduced to 160 to 1.
React at 80°C for 3 hours, and then add 20 to 30 tnF1 (
190-200℃ while reducing the pressure to
The mixture was heated to 100 mL and reacted for 2 hours, cooled, and butyl cellosolve was added to obtain 1,400 g of amide compound D (non-volatile content: 75%).

As shown in the attached table, in the comparative example without the addition of the amide compound according to the present invention, the applicability in water and the adhesion of the cured coating were significantly inferior. When amide compounds A, B, C, and D were added to this comparative example, the coating properties in water and the adhesion of the cured coating did not significantly improve as shown in Table 1.

that's all table

Claims (1)

[Scope of Claims] A resin composition containing an epoxy compound containing at least one epoxy group in the molecule and its room-temperature curing agent as a color vehicle, comprising 0.2 or more carboxyl groups in the molecule and 0. .An underwater coating type epoxy resin composition containing an amide compound containing two or more imidazoline rings.