JP2017179107A - Aqueous epoxy emulsion composition and anti-corrosive paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous epoxy emulsion composition that can produce a coating film with excellent flex resistance and water resistance, and an anti-corrosive paint comprising the composition.SOLUTION: An aqueous epoxy emulsion composition comprises epoxy resin (A), aromatic oligomer (B), and emulsifier (C), with the solid content concentration of 40-60 wt%, and an average particle size of the emulsion of 0.4-1.2 μm.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous epoxy emulsion composition capable of producing a coating film excellent in bending resistance and water resistance, and is suitably used for an anticorrosion repair coating for steel buildings.

  Conventionally, epoxy resin paints have been widely used as anticorrosion repair paints for steel structures. However, the epoxy resin paint contains a large amount of organic solvent and is diffused into the atmosphere when dried, and has problems such as fire, explosion risk, and environmental destruction. For this reason, in order to reduce organic solvents, it is desired to switch to water-based paints or solvent-free paints. A water-based paint is a paint that uses water as a solvent, and a solvent-free paint is a paint that does not use a solvent. A typical example of the water-based paint is an aqueous emulsion paint. That is, it is a paint in which resin or oil, which is the main component of the paint, is dispersed as fine droplets in water as a solvent and is in an emulsified (emulsion) state, and many of the water-based paints are of this type.

  However, the conventional water-based emulsion paint must be said to be inferior in water resistance, corrosion resistance, and the like as compared with the organic solvent-type paint (oil-based paint). In addition, solvent-free paints have problems such as short working time and difficulty in adjusting viscosity, and are not suitable for on-site painting for repairing steel structures.

  In order to improve the water resistance of an aqueous emulsion paint, Patent Document 1 proposes a method of introducing an epoxy group into an emulsifier. However, even with this method, although the water resistance is improved, the bending resistance is insufficient, the deformation of the steel surface cannot be followed, and there is a defect that the crack and the corrosion resistance are not satisfied. Further, Patent Document 2 proposes an epoxy resin composition in which a water-soluble or water-dispersible rubber is introduced, but the water resistance is not sufficient.

Japanese Patent Laid-Open No. 10-273515 JP-A-6-322139

  Accordingly, an object of the present invention is to provide an aqueous epoxy emulsion composition capable of producing a coating film excellent in flex resistance and water resistance. Another object of the present invention is to provide an anticorrosion paint using an aqueous epoxy emulsion composition applicable as an anticorrosion repair paint for steel buildings.

  As a result of diligent investigations to solve the above-mentioned problems of aqueous emulsion paints, the present inventors have made an aqueous epoxy emulsion composition in which an epoxy resin, an aromatic oligomer, and an emulsifier are forcibly emulsified to form a paint. The present inventors have found that a coating film excellent in flexibility can be formed and has excellent anticorrosion properties, and the present invention has been achieved.

  That is, this invention is an aqueous | water-based epoxy emulsion composition containing an epoxy resin (A), an aromatic oligomer (B), and an emulsifier (C), Comprising: An aromatic oligomer (B) with respect to 100 weight part of epoxy resins (A). ) 15 to 70 parts by weight, containing 5 to 20 parts by weight of emulsifier (C) with respect to 100 parts by weight of the total amount of epoxy resin (A) and aromatic oligomer (B), and having a solid content of 40 to 60 wt. %, And the average particle size of the dispersed particles of the emulsion is 0.4 to 1.2 μm.

  The aqueous epoxy emulsion composition is preferably an emulsion obtained by co-dispersing the epoxy resin (A) and the aromatic oligomer (B) with the emulsifier (C). The aromatic oligomer (B) includes coumarone resin or naphthalene resin.

  Moreover, this invention is a manufacturing method of the aqueous | water-based epoxy emulsion composition containing an epoxy resin (A), an aromatic oligomer (B), and an emulsifier (C), Comprising: It is aromatic with respect to 100 weight part of epoxy resins (A). 15 to 70 parts by weight of the oligomer (B) is blended, and 5 to 20 parts by weight of the emulsifier (C) is blended with 100 parts by weight of the total amount of the epoxy resin (A) and the aromatic oligomer (B). It is a method for producing an aqueous epoxy emulsion composition, wherein water or water and a solvent are blended so as to have a solid content concentration of 40 to 60% after mixing and forced emulsification.

  Furthermore, the present invention is an anticorrosion paint characterized by using the above-mentioned aqueous epoxy emulsion composition, and a steel structure characterized by being coated with the anticorrosion paint.

  ADVANTAGE OF THE INVENTION According to this invention, the water-based epoxy emulsion composition which can provide the coating film which is excellent in the flexibility with respect to a metal surface, adhesiveness, and water resistance can be provided, volatile organic compound (VOC) reduction at the time of repair coating, and environmental safety It is very useful for improving sex.

  Hereinafter, the present invention will be described in detail.

  In the present invention, the epoxy resin (A) has 2 or more, preferably 2 to 5, epoxy groups in one molecule, a number average molecular weight of about 350 to 2000, and an epoxy equivalent (g / eq) of about The thing of 150-800 is used suitably. Such an epoxy resin (A) is not particularly limited, and can be appropriately selected from known ones according to the use and required characteristics, and is known as an epoxy resin for paints. Resin is suitable.

  Examples of such epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol C type epoxy resins, bisphenol AD type epoxy resins, and liquid distilled bisphenol type epoxy resins. Bisphenol type epoxy resin, biphenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin and other novolak type epoxy resins, neopentyl glycol diglycidyl ether, polypropylene glycol diglycidyl ether, tri Aliphatic polyglycidyl ethers such as methylolpropane triglycidyl ether, 1.6 hexanediol diglycidyl ether, glycidyl ether Emission type epoxy resin and mixtures thereof. Examples of these commercially available epoxy resins include YD-127, YD-128, YD-134, YD-011, YD-012, YD-013, YD-014, YD-017, YD-019, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. YD-901, YD-902, YD-903, YD-904, YD-907, YD-909, YDF-170, YDF-175S, YDF-2001, YDF-2004, YD-8125, YDF-8170, ST- 3000, ST-4000, YDPN-638, YDCN-701, YDCN-702, YDCN-703, YDCN-704 and the like.

As the aromatic oligomer (B), xylene resin, toluene resin, ketone resin, coumarone resin, petroleum resin, naphthalene resin and the like can be used. Further, examples include condensates of formaldehyde with aromatic compounds such as xylene, toluene, naphthalene and the like, and at least one phenol selected from the group consisting of the aromatic compounds, phenols and alkylphenols. be able to.
Preferred examples of the aromatic compound include xylene, naphthalene, monomethylnaphthalene, dimethylnaphthalene, biphenyl, anthracene, phenanthrene, and pyrene. Preferred examples of the alkylphenol include carbon numbers such as cresol, xylenol, and t-butylphenol. Examples thereof include alkylphenols having 1 to 6 lower alkyl groups.

  In addition, aromatic oligomers (coumarone resin, indene resin, petroleum resin, etc.) obtained by polymerizing aromatic olefins such as coumarone, indene and styrene are also preferably used. An aromatic oligomer (modified coumarone resin or the like) in which the terminal of the aromatic oligomer is modified with phenols or naphthalene is also preferably used.

  Among these, coumarone resin and naphthalene resin are particularly preferably used because of excellent characteristics such as heat resistance and flexibility. Coumarone resin is a copolymer resin mainly composed of coumarone, indene and styrene, and is sometimes referred to as coumarone-indene resin. The naphthalene resin is an oligomer obtained from an aromatic compound containing naphthalene and formaldehyde, and is a resin mainly composed of naphthalene. The coumarone resin, indene resin or petroleum resin used in the present invention may contain 30% by weight or more, preferably 50% by weight or more of an aromatic olefin selected from indenes, coumarones and styrenes. . The naphthalene resin preferably contains a naphthalene structure as a constituent component in an amount of 30% by weight or more, preferably 50% by weight or more. The coumarone resin usually has about 5 to 20 wt% coumarone units, about 20 to 30 wt% styrene units and about 60 to 70 wt% indene units, and has a number average molecular weight of about 200 to 1000. However, indenes, coumarones and styrenes may be increased or decreased as appropriate.

  The content of the aromatic component in the aromatic oligomer is 30% by weight or more, preferably 50% by weight or more. The aromatic oligomer (B) is preferably solid or liquid at room temperature, preferably has a softening point of 100 ° C. or less and a number average molecular weight Mn of 500 to 2000. If the softening point exceeds 100 ° C., precipitation may occur during forced emulsification, making it difficult to emulsify. If Mn is less than 500, the coating film exhibits tackiness, and if it exceeds 2000, sufficient flex resistance is improved. May not be obtained. Here, the aromatic component is a unit derived from an aromatic compound, and the non-aromatic component is a unit derived from a non-aromatic compound such as formaldehyde.

  The blending ratio of the epoxy resin (A) and the aromatic oligomer (B) is 15 to 70 parts by weight, preferably 20 to 50 parts by weight with respect to 100 parts by weight of the epoxy resin. If the amount is less than 15 parts by weight, the effect of improving flex resistance and water resistance is not exhibited. If the amount exceeds 70 parts by weight, the compatibility with the epoxy resin is lowered, and the crosslinking density of the cured film is lowered.

  An emulsion obtained by co-dispersing the epoxy resin (A) and the aromatic oligomer (B) with the emulsifier (C) is preferable. Here, the co-dispersion means that the epoxy resin (A) and the aromatic oligomer (B) are not separately dispersed in the emulsifier (C) and emulsified, but the epoxy resin (A) and the aromatic oligomer (B). ) In advance, and the mixture is melt-mixed and dispersed in the emulsifier (C). The emulsifier (C) may be present at the time of melt mixing and may be blended in the melt mixing, but the former is preferred. As described above, when the epoxy resin (A) and the aromatic oligomer (B) are previously melt-mixed and then emulsified together, a coating film can be more uniformly dispersed in the coating film.

  A well-known thing can be used as an emulsifier (C). For example, anionic surfactants such as sulfate esters of higher alcohols, polyoxyethylene alkyl sulfate salts, alkylbenzene sulfone salts, polyoxypropylene alkyl sulfate salts, polyoxyethylene alkylphenol ether sulfate salts, polyoxypropylene alkylphenol ether sulfate salts, etc. Obtained by reaction of a polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxypropylene alkyl phenol ether, ethylene oxide propylene oxide block polymer, sorbitan derivative, terminal isocyanate group-containing compound and epoxy resin. , Nonionic surfactants with an oxazolidone ring in the molecule It is.

  As a compounding quantity of an emulsifier (C), 5-20 weight part with respect to 100 weight part of total amounts of an epoxy resin (A) and an aromatic oligomer (B), More preferably, 8-15 weight part is suitable. If it is less than 5 parts by weight, emulsification becomes difficult, and the particle size of the emulsion after phase inversion becomes excessive, which is not preferable. If it exceeds 20 parts by weight, the water resistance decreases due to an increase in polar groups derived from the emulsifier, which is not preferable.

  In addition to the above components, co-solvent (D) is added as needed together with water as a solvent when the viscosity at the time of heat-melt mixing is high and emulsion phase inversion is difficult, or when the film forming property at the time of coating film drying and curing is poor. can do.

  These cosolvents (D) are not particularly limited as long as they can dissolve the epoxy resin (A) and the aromatic oligomer (B). For example, ethylene glycol monoprolyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, cyclopentanone, cyclohexanone, benzyl alcohol, etc. It is done.

  As a compounding quantity of a cosolvent, 0-10 weight part is preferable with respect to 100 weight part of the mixture of an epoxy resin (A), an aromatic oligomer (B), and an emulsifier (C). It is preferable to minimize the addition amount because of the problem of solvent emission to the environment. If it exceeds 10 parts by weight, the resulting coating composition is not preferred because it is likely to become a dangerous substance.

  The aqueous epoxy emulsion composition of the present invention is an aqueous dispersion in which the components (A) to (D) are dispersed in an aqueous medium (solvent). The solid content of the aqueous epoxy emulsion composition is preferably 40 to 60% (wt%). If it is less than 40%, there are problems such as a lot of moisture that restricts the paint design, emulsion particles tend to settle, viscosity becomes low and thick film coating becomes difficult. On the other hand, when it exceeds 60%, handling becomes difficult due to excessive viscosity and thixotropy.

In the method for producing an aqueous epoxy emulsion composition of the present invention, the epoxy resin (A), the aromatic oligomer (B) and the emulsifier (C) are subjected to forced emulsification after heating and mixing. There is a production method in which a hydrophilic group is introduced into an epoxy resin to self-emulsify, but the cured resin skeleton contains a hydrophilic group, which is not preferable because water resistance is lowered.
Forcible emulsification, it is preferable to first make a water-in-oil (W / O type) emulsified state, and then add water to invert the phase to obtain an oil-in-water type (O / W type) emulsified state. By becoming an O / W type, properties as a water-based paint such as dilution and washing with water are manifested.

  The apparatus for carrying out the production method of the present invention is not particularly limited. For example, the apparatus with a stirrer capable of introducing an aqueous medium by mixing and heating the epoxy resin (A), the aromatic oligomer (B), and the emulsifier (C). Known materials such as glass and stainless steel can be used. As a mixing method, an epoxy resin (A), an aromatic oligomer (B), an emulsifier (C), an organic solvent as needed, and depending on the softening point of each component (A to C) while stirring and mixing, Specifically, it is kept at 80 ° C. to 120 ° C. for 20 minutes to 1 hour, heated and dissolved and mixed, and then allowed to cool to 60 ° C. to 90 ° C. while stirring at a rotational speed of 200 to 400 rpm, and then the aqueous medium is solidified to 80 to 90%. A method of gradually adding and emulsifying the composition so as to be% is suitable. After emulsification, the emulsified state is stabilized by maintaining at the same temperature and the same rotation speed for 20 minutes to 1 hour. Subsequently, the aqueous medium was added at 40 ° C. to 80 ° C. at the same rotation speed so that the solid content concentration was 60 to 78%, and the phase was changed, and then stirring was continued until the desired dispersed particle size was obtained. The aqueous epoxy emulsion composition of the present invention can be obtained by adding an aqueous solvent so that it becomes a minute (40 to 60 wt%).

Various curing agents, pigments, rust preventive agents, particularly phosphoric acid rust preventive pigments can be blended with the aqueous epoxy emulsion composition to obtain a desired anticorrosive paint of the present invention.
Various known epoxy resin curing agents can be used as the curing agent. For example, a polyamine emulsion in which a polyamine containing two or more amino groups per molecule is dispersed in an aqueous medium, or an aqueous solution of a water-soluble polyamine. Is preferred.

  As the polyamine, a low molecular polyamine or a high molecular polyamine resin can be used. Examples of such polyamines or polyamine resins include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, triaminopropane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine and 1,3-bisaminomethylcyclohexane. Aliphatic polyamines; aromatic polyamines such as phenylenediamine, metaxylylenediamine, paraxylylenediamine, and diaminodiphenylmethane; polyamine compounds such as polyoxyethylenediamine, polyoxypropylenediamine, triethyleneglycoldiamine, and tripropyleneglycoldiamine; In addition, a water-soluble modified polyamine resin obtained by modifying a polyamine compound by a known method may be mentioned.

  Although a hardening | curing agent is mix | blended with an aqueous | water-based epoxy emulsion composition, it is good also as a coating material etc., From a viewpoint of storage stability, it is good to set it as a 2 liquid type coating material as another solution.

  Furthermore, if necessary, inorganic fillers, wetting agents, dispersants, antifoaming agents, viscosity modifiers, thickeners, leveling agents, anti-sagging agents, pH adjusting agents, cross-linking agents, stabilizers, force-proofing agents, Additives such as an antifreezing agent, a film forming aid, an antioxidant, a flash rust preventing agent, a coupling agent, a chelating agent, and a wetting improver can be blended.

  In addition, the type of substrate to which the anticorrosion paint using the aqueous epoxy emulsion composition of the present invention is applied is not particularly limited, and cement cement, ALC panel, precast concrete plate, mortar, flexible plate, metal ( Steel, aluminum, galvanized, etc.), glass, wood, insulation, plastics, paint coatings such as existing paints and finish coating materials, and waterproof materials, etc. It can be applied to. Preferably, it is a steel structure.

  Hereinafter, the present invention will be described more specifically, but the present invention is not limited thereto.

(Manufacture of emulsifiers)
Synthesis example 1
480 g (0.15 mol) of polyethylene glycol with a molecular weight of 3200 is charged into a glass four-necked reactor equipped with a stirrer, thermometer, cooling pipe and nitrogen gas introducing device, nitrogen gas is introduced, heated to 120 ° C., melted and dehydrated did. Thereafter, it was cooled to 70 ° C., and 55.7 g (0.32 mol) of Coronate T-80 (manufactured by Nippon Polyurethane Co., Ltd., 2,4TDI 80 wt%, 2,6 TDI 20 wt%) was charged and held at 80 ° C. for 5 hours. Next, 180 g (0.48 mol) of Epototo YD-128 (Nippon Steel & Sumikin Co., Ltd. bisphenol A type liquid epoxy resin; epoxy equivalent 187 g / eq) was charged and heated to 120 ° C., and 0.8 parts of tetramethylammonium bromide was used as a catalyst. It was added and reacted at 150 ° C. for 5 hours to confirm the disappearance of isocyanate by IR measurement. The epoxy equivalent (g / eq) of the obtained emulsifier (c1) was 1120.

Example 1
Epototo YD-011 (manufactured by Nippon Kayaku Epoxy Manufacturing Co., Ltd .: solid epoxy resin, epoxy equivalent 450 to epoxy resin as an epoxy resin in a four-necked glass reactor equipped with a stirrer, thermometer, cooling pipe and water addition device 500, softening point 60-70 ° C.) 362 parts by weight, 88 parts by weight of coumarone resin G-90 (manufactured by Nikko Chemical Co., Ltd.) as an aromatic oligomer, 50 parts by weight of the emulsifier, 50 parts by weight of ethylene glycol monopropyl ether The solution was heated and dissolved at 110 ° C. with stirring, held for 30 minutes, and mixed. Then, after naturally cooling to 80 ° C., 71 parts by weight of pure water was added and emulsified (W / O emulsification) by stirring at 80 ° C. for 30 minutes. Subsequently, 51 parts by weight of pure water was added to cause phase inversion (O / W emulsification). After the phase inversion, stirring was continued until the average particle size became 0.8 μm or less. After the average particle size of the emulsion particles becomes 0.8 μm or less, a total of 325 parts by weight of pure water is added stepwise, diluted, and stirred to obtain an epoxy equivalent of 633 (per solid content) and a solid content of 50.9. %, An emulsion 1 having an average particle size of 0.68 μm was obtained. Here, the solid content is a component excluding volatile components such as water and a solvent.

Example 2
An epoxy equivalent of 657, a solid content of 50.0%, and an average particle size of 0.54 μm were used in the same manner as in Example 1 except that naphthalene formaldehyde resin A-053 (manufactured by Nikkaku Chemical Co., Ltd.) was used as the aromatic oligomer. Emulsion 2 was obtained. In the following Examples and Comparative Examples, the epoxy equivalent is an epoxy equivalent per solid content.

Example 3
Epoxyto YD-012 (manufactured by Nippon Kayaku Epoxy Manufacturing Co., Ltd .: solid epoxy resin, epoxy equivalent: 600 to 700, softening point: 75 to 85 ° C.) was used as the epoxy resin in the same manner as in Example 1 to obtain an epoxy. Emulsion 3 having an equivalent weight of 869, a solid content of 51.2%, and an average particle size of 0.73 μm was obtained.

Example 4
Emulsion 4 having an epoxy equivalent of 860 and a solid content of 52.7% was obtained in the same manner as in Example 1 except that YD-012 was used as the epoxy resin and A-053 was used as the aromatic oligomer.

Comparative Example 1
An emulsion having an epoxy equivalent of 645, a solid content of 51.0%, and a 0.35 μm in the same manner as in Example 1 except that an aliphatic oligomer ADEKA POLYOL P-700 (manufactured by ADEKA) was used instead of the aromatic oligomer. 5 was obtained.

Comparative Example 2
An epoxy equivalent of 646, a solid content of 51.5%, and an average particle size of 0.1% were used in the same manner as in Example 1 except that an aliphatic oligomer ADEKA POLYOL P-2000 (manufactured by ADEKA Corporation) was used in place of the aromatic oligomer. An emulsion 6 having a thickness of 38 μm was obtained.

Comparative Example 3
Epoxyto YD-011 450 parts by weight, the emulsifier (c1) 50 parts by weight, ethylene glycol monopropyl ether 50 parts by weight, except that no aromatic oligomer is blended, the epoxy equivalent 511, An emulsion 7 having a solid content of 51.4% and an average particle size of 0.57 μm was obtained.

Comparative Example 4
Emulsion 8 having an epoxy equivalent of 694 and a solid content of 50.1% was obtained in the same manner as in Comparative Example 3 except that YD-012 was used as the epoxy resin.

Comparative Example 5
EXAMPLE 1 450 parts by weight of Epototo YD-011, 50 parts by weight of polyethylene glycol-based Maxemul 9107 (manufactured by Croda Japan) as an emulsifier and 50 parts by weight of ethylene glycol monopropyl ether were prepared, and the blending amount of the aromatic oligomer was set to 0. In the same manner as above, an emulsion 9 having an epoxy equivalent of 515, a solid content of 50.7%, and an average particle size of 0.47 μm was obtained.

Comparative Example 6
In a 4-neck glass reactor equipped with a stirrer, thermometer, cooling pipe and water addition device, 450 parts by weight of A-053 as an aromatic oligomer, 50 parts by weight of an emulsifier (c1), ethylene glycol monopropyl ether 50 parts by weight were charged, dissolved by heating at 100 ° C. with stirring, held for 30 minutes, and mixed. After mixing, after naturally cooling to 70 ° C., 71 parts by weight of pure water was added and held for 30 minutes to emulsify (W / O emulsification). Subsequently, 51 parts by weight of pure water was added to cause phase inversion (O / W emulsification). After the phase inversion, stirring was continued until the average particle size became 0.8 μm or less. After the average particle size of the emulsion particles becomes 0.8 μm or less, a total of 325 parts by weight of pure water is added and diluted in stages to obtain an emulsion 10 having a solid content of 49.6% and an average particle size of 0.55 μm. Obtained.

(Manufacture and painting of anticorrosion paints)
Example 5
175.3 parts by weight of Emulsion 1 and 19.7 parts by weight of Daitokural I-5986 amine value 167 (manufactured by Daito Sangyo Co., Ltd.) as a curing agent were mixed into a 0.3 mm thick cold-rolled steel sheet (SPCC-SD). A cold-rolled steel sheet (SPCC-SD) having a film thickness of 70 μm and 2 mm was coated with a brush so as to have a film thickness of 130 μm, and cured for one week in a room temperature room to obtain a test piece.

Examples 6-8, Comparative Examples 7-12
Except that the emulsion and the curing agent were blended in the types and amounts shown in Table 1, anticorrosion paints were produced in the same manner as in Example 5, and these anticorrosion paints were coated on steel plates to obtain test pieces.

Example 9
170.2 parts by weight of Emulsion 1 and 23.9 parts by weight of Fujicure FXH-935 amine number 170 (manufactured by T & K Talker Co., Ltd.) as a curing agent are mixed into a 0.3 mm thick cold-rolled steel sheet (SPCC-SD). A cold-rolled steel sheet (SPCC-SD) having a thickness of 70 μm and 2 mm was coated with a brush so as to have a film thickness of 130 μm, and cured for one week in a room temperature room to obtain a test piece.

Examples 10-12, Comparative Examples 13-18
Except that the emulsion and the curing agent were blended in the types and amounts shown in Table 1, anticorrosion paints were produced in the same manner as in Example 9, and these anticorrosion paints were coated on steel plates to obtain test pieces.

  Various physical properties were evaluated by the following methods using the test pieces thus obtained.

(Test method)
(Measurement of average particle size of emulsion dispersed particles)
The particle size distribution / average particle size of the produced emulsion was determined by using a laser diffraction / scattering particle size distribution meter Microtrac MT3000II (manufactured by Nikkiso Co., Ltd.) and the cumulative frequency of 50% (D ₅₀ ) as the average particle size.

(Bend resistance test)
In accordance with JIS K5400.8.1, a bending resistance test was performed on a test piece coated on a 0.3 mm thick cold-rolled steel sheet (SPCC-SD). The diameter of the mandrel was 10 mm, 6 mm, and 4 mm.
The case where no abnormality was found on the coating piece was marked with ○, the case where some wrinkles or whitening was observed was marked with Δ, and the case where peeling of the coating film was seen was marked with ×.

(Adhesion test-grid pattern)
In accordance with JIS K5400.8.5.2, an adhesion test was performed on a test piece coated on a 0.3 mm thick cold-rolled steel sheet (SPCC-SD). The clearance interval was 1 mm.
In the table, 100/100 indicates that no grids were peeled for 100 grids, 50/100 indicates that 50 eyes corresponding to half were peeled, 0 / 100 indicates that all grids have been removed.

(Water resistance test)
The back and end surfaces of a test piece coated on a 2 mm cold-rolled steel plate (SPCC-SD) were sealed with a commercially available solvent-based epoxy resin paint, dried, and then immersed in a SUS vat containing tap water for 1 week at 25 ° C. Immediately after taking out the test piece, the film was observed for wrinkles, cracks, blisters, and peeling. Further, after being left for 2 hours, gloss and cloudiness were observed.
The case where no abnormality was found on the coating piece was marked with ○, the case where some abnormality was found was marked with Δ, and the case where abnormality was found on the entire coating film was marked with ×.

  The test results are shown in Tables 2 and 3.

Claims (6)

  An aqueous epoxy emulsion composition comprising an epoxy resin (A), an aromatic oligomer (B), and an emulsifier (C), the aromatic oligomer (B) being 15 to 70 parts by weight per 100 parts by weight of the epoxy resin (A) Containing 5 to 20 parts by weight of an emulsifier (C) with respect to 100 parts by weight of the total amount of the epoxy resin (A) and the aromatic oligomer (B), the solid content concentration is 40 to 60 wt%, An aqueous epoxy emulsion composition, wherein the dispersed particles have an average particle size of 0.4 to 1.2 μm.   The aqueous epoxy emulsion composition according to claim 1, which is an emulsion obtained by co-dispersing the epoxy resin (A) and the aromatic oligomer (B) with an emulsifier (C).   The aqueous epoxy emulsion composition according to claim 1, wherein the aromatic oligomer (B) is a coumarone resin, an indene resin, a petroleum resin, or a naphthalene resin.   It is a manufacturing method of the aqueous | water-based epoxy emulsion composition containing an epoxy resin (A), an aromatic oligomer (B), and an emulsifier (C), Comprising: Aromatic oligomer (B) 15-70 with respect to 100 weight part of epoxy resins (A) 5 parts by weight of the emulsifier (C) is blended with 100 parts by weight of the total amount of the epoxy resin (A) and the aromatic oligomer (B). The manufacturing method of the water-based epoxy emulsion composition characterized by mix | blending water or water and a solvent so that it may become -60 wt%, and carrying out forced emulsification.   An anticorrosive paint comprising the aqueous epoxy emulsion composition according to any one of claims 1 to 3. A steel structure coated with the anticorrosive paint according to claim 5.