JP2002338662A - Epoxy resin composition for application to wet surface and in water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which has good applicability and adherence to a base material even when applied to a wet surface and in water, and which gives a coating film excellent in anticorrosiveness. SOLUTION: The epoxy resin composition for application to a wet surface or in water consists of an epoxy resin, a curing agent for the epoxy resin, an inorganic filler and an additive, wherein the curing agent contains an aromatic alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for wet surface and underwater construction, and more particularly to a tunnel,
The present invention relates to an epoxy resin composition to be applied as a paint, an adhesive, a sealing agent, or the like on a wet surface such as a sewer pipe or a common ditch or in water.

[0002]

2. Description of the Related Art Conventionally, paints and sealing agents are often applied to underwater or wet surfaces for structures that have a lot of contact with water, for the purpose of preventing penetration of water into the base material and preventing rust. Many. In particular, epoxy resin-based paints and sealing agents have a great demand for construction because of their anti-corrosion properties and their adhesive properties, and for that purpose, epoxy resin compositions for wet surfaces or underwater construction have been developed. . However, the conventionally developed epoxy resin composition for wet surface or underwater construction has not been sufficiently adhered to a base material, and has not been satisfactory in long-term anticorrosion performance.

[0003] Epoxy resins for civil engineering and construction are often required to have curability in water and adhesion to wet surfaces. But,
Generally, in water curing, a water-soluble curing agent such as an amine-based curing agent elutes into water and cannot be sufficiently cured. Therefore, there is a method of using an excess of polyamine as a current technique. This is a technique in which the polyamine preferentially wets the adherend and replaces it with water. That is, it is important to use an epoxy resin / polyamine-based curing agent as a main component, and to use the curing agent in excess of a theoretical value by 15 to 30%. However, in this method, while curing in water is good, it is likely to cause poor curing due to the excessive amount of polyamine in a normal state. Further, the cost of the polyamine resin is considerably higher than that of the epoxy resin, so that the cost is greatly increased. Therefore, it seems that there are few places where various paint manufacturers actually adopt this method.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has good coatability and adhesion to a substrate even when applied on a wet surface or in water, and forms a coating film. An object of the present invention is to propose an epoxy resin composition that gives a coating film having excellent anticorrosion properties in such a case.

[0005]

An epoxy resin composition for wet surface and underwater application according to the present invention comprises a wet surface and epoxy resin composition for underwater application comprising an epoxy resin, an epoxy curing agent, an inorganic filler and additives. Wherein the curing agent contains an aromatic alcohol.

The aromatic alcohol to be added to the epoxy curing agent is preferably at least one of benzyl alcohol and alkyl-substituted benzyl alcohol.

The inorganic filler is preferably at least one selected from magnesium oxide, calcium oxide, aluminum oxide, calcium carbonate, silica, clay, talc, mica, and kaolin.

[0008] The amount of the inorganic filler is preferably 20 to 80% by weight based on 100 parts by weight of the epoxy resin composition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin composition for wet surface and underwater application according to the present invention comprises an epoxy resin cured by mixing a substance having a property of displacing and excluding water in the composition. The purpose is to make That is, an appropriate mixed solvent that does not mix with water is used as a curing component of the epoxy resin to replace water on the coated surface to firmly fix the coated film.

When the adherend is coated with the epoxy resin / aromatic alcohol-containing polyamine resin mixture, the affinity of the aromatic alcohol for the adherend before curing in water is larger than that of water. Migrates to wet surfaces and replaces water molecules. Thereafter, the paint eventually becomes a chemically dry surface. The epoxy resin / aromatic alcohol-containing polyamine resin mixture enhances the water-replaceability of the composition by increasing the amount of pigments and fillers in the composition and at the same time having high viscosity characteristics, and at the same time coating during the drying period. This is effective in maintaining the original performance. In addition, when a high filler content is used, when water moves to the outside through the coating film, the water easily moves to the outside through the coating film, and this effect is considered to increase.

As the epoxy resin, various epoxy resins used for paints, adhesives, sealing agents and the like can be used.

The epoxy resin is, for example, an epoxy resin having an average of more than one glycidyl group in the molecule, and has an average of one glycidyl ether group, glycidyl ester group, glycidylamine group, and glycidylimine group in the molecule. The epoxy resin having the above is mentioned. These epoxy resins can be used alone or in combination of two or more.

Further, a reactive diluent such as olefin oxide, glycidyl methacrylate and butyl glycidyl ether, or a non-reactive diluent such as glycol ether ester can be used as a diluent in the epoxy resin.

As the curing agent, m-xylenediamine,
One or more amine compounds selected from bis- (aminomethyl) cyclohexane, methylenedi (cyclohexylamine), and norbonenediamine can be used.

The amount of the curing agent is preferably 7.5 to 12.5 parts by weight based on 100 parts by weight of the epoxy resin.

As the aromatic alcohol to be added to the curing agent, benzyl alcohol, alkyl-substituted benzyl alcohol and the like can be used.

The amount of the aromatic alcohol to be added is 1
1 to 5% by weight, preferably 2 to
3% by weight. 5% by weight of aromatic alcohol added
Exceeding the curing shrinkage is undesirably large. The alcohol used together with the aromatic alcohol,
The content is preferably in the range of 1 to 2% by weight in order to enhance the effect of addition.

[0018] In addition to the aromatic alcohol, a hardly water-soluble aliphatic alcohol can be added to the curing agent. Examples of the aliphatic alcohol which is hardly soluble in water include n-butyl alcohol, isobutyl alcohol, 1-pentanol, di-2-methyl-1-butanol, diethylcarbinol, n-hexyl alcohol, 2-ethylbutyl z-flow alcohol, Ethylhexyl alcohol, 3,5
Examples include at least one water-insoluble alcohol selected from 5-trimethylhexyl alcohol, hexyl alcohol and 2-methylhexyl alcohol.

The inorganic filler includes at least one selected from magnesium oxide, calcium oxide, aluminum oxide, calcium carbonate, silica, clay, talc, mica, and kaolin. Especially in the epoxy resin composition for construction in water, to prevent contamination in water,
Since it is necessary to settle the paint, it is preferable to use an inorganic filler having a large specific gravity.

The compounding amount of the inorganic filler is 10
When the content is 0% by weight, the range is preferably 20 to 80% by weight. If the content is more than this range, the viscosity of the resin coating material is increased and the coating workability is undesirably reduced. On the other hand, if the addition amount is less than this, the adhesion to the substrate in water is poor, and even when applied to the substrate, the coating film tends to be peeled off due to buoyancy, water flow, etc. of the water.

In order to improve the dispersibility of the pigment, for example, an auxiliary agent such as a surfactant or an antifoaming agent for defoaming can be used. There is no loss in performance.

Further, other additives can also be used. Examples of such additives include bengara, titanium white, and the like.
Color pigments such as phthalocyanine blue, chromic acid-based, phosphoric acid-based anticorrosive pigments, and other additives such as silane coupling agents, sedimentation agents, anti-sagging agents, thickeners, antibacterial agents,
Stabilizers and the like can be added.

[0023]

EXAMPLES The present invention will be described below with reference to examples.

(Preparation of epoxy base) 6 parts by weight of aliphatic cyclic epoxy resin EP-4085 (manufactured by Asahi Denka Co., Ltd.), 35 parts by weight of block urethane prepolymer QR-9187L (manufactured by Asahi Denka Co., Ltd.), NBR modified Epoxy resin EPR
While mixing and stirring 4 parts by weight of -1508 (manufactured by Asahi Denka Co., Ltd.), 55 parts by weight of colloidal calcium carbonate Calfine # 500 (manufactured by Maruo Calcium Co., Ltd.) was added, and the mixture was defoamed and stirred. Then, a paste-like epoxy resin base material was prepared.

(Preparation of curing agent) Modified aliphatic polyamine E
15 parts by weight of H-265-4 (manufactured by Asahi Denka Co., Ltd.) and 1.5 parts by weight of tertiary amine (2,4,6, trisdimethylaminomethylphenol) EHC-30 (manufactured by Asahi Denka Co., Ltd.) Mixing, defoaming and stirring were performed to prepare a liquid epoxy resin curing agent.

(Mixing Conditions of Main Agent and Curing Agent in Examples) The amounts of the curing agent and benzyl alcohol shown in Table 1 were mixed with 100 parts of the main agent by a mixer.

(Mixing Conditions of Main Agent and Curing Agent of Comparative Example) The amount of the curing agent shown in Table 1 was mixed with 100 parts of the main agent by a mixer.

[0028]

[Table 1] (Preparation of test piece) Concrete piece is JIS R5201
Mortar prepared by the method specified in 10.4 (How to make specimens) of (Cement physical test method) is molded using a metal mold with inner dimensions of 70 × 70 × 20 m, After curing for 24 hours, the mold was removed, and then cured in water at 20 ° C. and 2 ° C. for 6 days, and then returned to the curing room for 7 days or more. Thereafter, the lower surface at the time of molding was sufficiently polished using No. 150 abrasive paper specified in JIS R6252 and used.

Adhesion test application method (Adhesion application method in normal state) A mixture of the main agent and the curing agent was applied to a thickness of 1 mm using a bar code on the test specimen, and the specimen was kept in a curing room for 14 days. After standing, the measurement was performed.

(Adhesive Coating Method on Wet Surface) The above test specimen having a sufficiently wet surface is coated with a bar code to a thickness of 1 mm, and then applied on a standard sand or silica sand in a water tank. The specimen was poured horizontally so that the upper surface of the substrate of the specimen appeared at a position about 5 mm from the water surface. After 10 days had passed in that state, the specimen was taken out, and the side of the specimen was turned down. Dry in a constant temperature room at 3 ° C for 24 hours.
It was measured after standing for 4 hours.

(Adhesive Coating Method for Underwater Construction) The above test piece was coated with a barcode to a thickness of 1 mm, immediately immersed in a standard state, and after 10 days in that state, the test piece was It was taken out and measured in a wet state.

(Adhesion coating method of acid resistance and alkali resistance) The above test piece was coated to a thickness of 1 mm using a bar code, left standing in a curing room for 14 days, and then added with a 10% aqueous sulfuric acid solution. After being immersed in a 10% aqueous sodium hydroxide solution for 10 days, the test specimen was taken out, and the side face of the test specimen was turned down.
The sample was dried in a constant temperature room at 3 ° C. for 24 hours, then left in a general curing room for 24 hours, and then measured.

(Measurement Method) One day before the end of curing, the surface of the ethoxy resin composition was cut into a size of 40 × 40 mm until it reached the substrate, and then held horizontally in a general curing room, and the sample was coated. Apply an epoxy quick-drying adhesive to the surface, gently place a rigid jig for Kenken Tensile Tester and attach it, place a 1kg weight on top of it, and wipe off the adhesive that has protruded around. After standing for 24 hours, the weight was removed, and the maximum load was determined by applying a tensile force in the vertical direction to the surface of the test body using an Ken-ken type tensile tester.

The results are shown in Table 1.

Although the amount of the curing agent is the same in the examples and the comparative examples, the presence or absence of benzyl alcohol was compared. The results show that the examples are significantly improved particularly on wet surfaces and underwater curing. I understand. That is, the value of the adhesive strength is twice or more, and it can be seen from the fact that the material is broken at the interface of the epoxy resin composition of CF in the comparative example while the material is broken in the concrete piece of MF in the example. Under normal conditions, acid resistance and alkali resistance also show the same or higher adhesive strength as with and without the addition of aromatic alcohol.By adding benzyl alcohol to the curing agent, not only during normal conditions, An epoxy composition having excellent wet strength can be obtained.

[0036]

As described above, according to the present invention, even when applied on a wet surface or in water and in a state, the coatability and adhesiveness to an adherend are good, and when a coating film is formed, anticorrosion occurs. An epoxy resin composition having excellent properties and having a cost merit was obtained.

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Claims (4)

[Claims] 1. An epoxy resin composition for wet surface and underwater application, comprising an epoxy resin, an epoxy curing agent, an inorganic filler, and an additive, wherein the curing agent contains an aromatic alcohol. Epoxy resin composition for wet surface and underwater construction 2. The wet surface and underwater epoxy resin composition according to claim 1, wherein the aromatic alcohol added to the epoxy curing agent is at least one of benzyl alcohol and alkyl-substituted benzyl alcohol. 3. The wet surface and water according to claim 1, wherein the inorganic filler is at least one selected from magnesium oxide, calcium oxide, aluminum oxide, calcium carbonate, silica, clay, talc, mica, and kaolin. Epoxy resin for construction. 4. The epoxy resin composition according to claim 1, wherein the amount of the inorganic filler is 20 to 80% by weight based on 100 parts by weight of the epoxy resin composition.