JP2770245B2 - Underwater coating type epoxy resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an underwater coating type epoxy resin composition used for forming an adhesive or protective coating layer in water or in a wet state.

(Prior Art) As is well known, many steel structures and concrete structures constructed in the sea, on the beach, in rivers, lakes, swamps, and the like are constantly exposed to severe corrosive environments. Therefore, maintenance of these structures such as steel sheet pile revetment, steel pipe piles of port facilities, piers, dam gates, floodgates, etc. is required.

By the way, heretofore, it has been known that the anticorrosion coating method in water is performed by damming the surroundings and draining water. However, this method is very expensive. For this reason, underwater coating-type anticorrosion materials based on polyamide-cured epoxy resin, modified amine-cured epoxy resin, unsaturated polyester resin, etc., which can reduce the working cost without damaging the surrounding area and lowering the work cost, have been put into practical use. ing.

(Problems to be Solved) However, the conventional underwater coating type paint using each resin as a base has a drawback that adhesion to a metal or concrete surface is insufficient in water, in the sea, or on a wet surface.

In addition, conventional underwater curing type paints are disc sanders,
The metal surface or concrete surface cleaned by sand blasting or other means is placed in water, in the sea, or in a wet state, and as time passes, the paint becomes slippery due to the returning rust state or the adhesion of microorganisms in the water or the sea. This caused a phenomenon that coating could not be performed, and it was necessary to carefully reprocess with a scourer or the like immediately before coating. In addition, the coating film thus applied also has an adhesion of 20 to 30 kg / cm ² , particularly in natural seawater.
It was often found that it was less than 10 kg / cm ² in some places. This is considered to be due to variation in the time from reprocessing to coating.

Accordingly, an object of the present invention is to provide a resin composition having excellent coatability in water, in the sea, or on a wet surface with a brush, rubber wrench, iron, roller, or the like, and a formed coating film is excellent. An object of the present invention is to provide an underwater curable resin composition having adhesion and corrosion resistance.

(Means for Solving the Problems) The epoxy resin system serving as the base of the present invention is represented by the general formula-2 [Wherein R represents a hydrogen or hydrocarbon group] Those having at least one epoxy group in the molecule and having an epoxy equivalent of 70 to 1,000 are preferably used. For example, glycidyl ethers of phenol compounds such as bisphenol A, bisphenol F, formalin precondensates of phenol compounds, glycidyl esters of polycarboxylic acids such as adipic acid, phthalic acid and dimer acid, and polyhydric alcohols such as polyethylene glycol and neopentyl glycol. Glycidyl ethers, glycidylated amino compounds such as xylylenediamine and octylamine, and the like are listed.

The feature of the present invention is that, in addition to the above epoxy resin, [Wherein R ¹ is an organic group having 1 or more carbon atoms, R ² is hydrogen or a hydrocarbon having 1 or more carbon atoms, Z is a skeleton structure of an active hydrogen-containing compound that can be substituted with an epoxy group, and X is O , N, S, COO, l represents an integer of 1 or 2, m represents an integer of 1 to 5, and n represents an integer of 1 to 3, respectively. Wherein a phosphorus atom-containing epoxy compound represented by the following formula is used, and an epoxy group-containing phosphonic acid ester or phosphinic acid ester is used.

Examples of epoxy group-containing phosphonates and phosphinates include: (Wherein R represents an alkyl group or a phenyl group).

The above-mentioned phosphorus atom-containing epoxy compound is preferably used in the entire epoxy resin composition in a range of 0.005 to 0.3 g equivalent in terms of phosphorus atom. At 0.005 g equivalent or less, the effect of the present invention is hardly obtained, and at 0.3 g equivalent or more, water resistance and physical properties decrease, which is not preferable.
Most preferably, it is used in the range of g equivalent.

As a curing agent for the epoxy resin, aliphatic amines, alicyclic amines, aromatic amines, or amide modifications thereof, adduct modifications, Mannich reaction modifications, Michael reaction modifications, carbonyl modifications and These mixtures are used as needed.

Other components of the resin composition of the present invention include extenders such as talc, mica, clay, kaolin, barium sulfate, calcium carbonate, alumina, zinc white, silica powder, titanium white, graphite, red iron oxide, and yellow oxide. Color pigments such as iron, organic red, organic yellow, organic blue, organic green, etc., rust preventive pigments such as chromic acid type, molybdic acid type, phosphoric acid type, boric acid type, ferrite type, lead acid type, stainless steel powder, zinc Powder, metal powder such as aluminum powder,
Flaky pigments such as glass flakes, stainless flakes, aluminum flakes, and plastic flakes; fibrous substances such as asbestos / vegetable fibers, glass fibers, carbon fibers, and synthetic fibers; silane coupling agents; anti-settling / sagging agents; 1-171822 and Japanese Patent Application No. 1-111757
Additives such as the surfactant described in 0 can be appropriately selected to impart desired hue, coatability, and anticorrosion.

The resin composition according to the present invention can be applied to a water or wet surface with a brush, a roller, a spatula, a trowel, or the like.

〔effect〕

The phosphorus atom-containing epoxy compound used in the present invention improves the adhesion of the epoxy resin composition and suppresses the progress of rusting from a damaged portion of the mechanical coating. In addition, the surface of the copper material surface-treated at the water edge causes return rust immediately, which has been a factor that hinders adhesion, but the epoxy resin composition according to the present invention is applied to the surface of the steel having return rust. However, the adhesion is hardly reduced, and an excellent anticorrosion effect can be exhibited over a long period of time.

(Examples) The compositions and test results used in Comparative Example-1 and Examples-1 to 5 are shown in Table-1.

(Adjustment of paint) The main agent using an epoxy compound as a vehicle and the curing agent using an amine compound as a vehicle were each dispersed and adjusted uniformly with a high-speed disperser, and mixed and used at a predetermined ratio. .

(Adjustment of test plate) Two types, one in which a 70 × 20 × 2.3 mm sandblasted steel plate was immersed in seawater for 1 hour to cause rust, and the other in which seawater was applied and left in air for 1 hour to cause rust Was adjusted.

The test plate prepared as described above was horizontally fixed in sea water, spread using a rubber spatula so as to have a thickness of about 500 μm, and cured for one week in sea water to obtain a test piece.

(Evaluation method) 1) Initial adhesiveness The surface of the coating film was roughened with sandpaper,
The specimen of cm ² was adhered using an epoxy adhesive, peeled off vertically with a tensile tester, and the force required for breaking (kgf /
cm) and the residual ratio of the coating film was visually evaluated. Three points were measured for each test piece, and the average value was recorded.

(Salt spray test) Insert a cut line that reaches the substrate in the diagonal direction of the test piece,
After exposure for 1000 hours in a salt spray tester, the coating was peeled off from the cut line with a knife until normal adhesion was exhibited, and the width of the portion where the adhesion was reduced on both sides of the cut line was measured.

As a result of the evaluation as described above, as compared with the comparative example not according to the present invention, Examples -1 to 5 show that the adhesive force on the rusted steel sheet was remarkably improved, The range of the decrease in the adhesive force from the cut line in the spray test was also significantly reduced, showing an excellent anticorrosion effect.

Note-1: Phosphorus atom-containing epoxy compound-1 Glycidyl-α-methyl-β- (dibutoxy) phosphinylpropionate Note-2: Phosphorus atom-containing epoxy compound-2 di (butyl) N, N-bis (2-glycidoxyethyl)
Aminomethylphosphonate Note-3: Phosphorus atom-containing epoxy compound-3 1.4-Diglycidoxy-2 (dibutoxy) phosphinylmethylbenzene

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tatsuhiro Tanaka 1-15-2 Yoshishima Higashi, Naka-ku, Hiroshima City, Hiroshima Prefecture Inside China Paint Co., Ltd. (56) References JP-A-1-259070 (JP, A) JP-A-63-33479 (JP, A) JP-A-61-211331 (JP, A) JP-A-61-211327 (JP, A) JP-A-61-91217 (JP, A) (58) (Int.Cl. ⁶ , DB name) C08G 59/20-59/38 C09D 163/00-163/10 C09D 5/08

Claims (2)

(57) [Claims] 1. A resin composition comprising an epoxy resin and a curing agent thereof as a main vehicle, comprising a resin represented by the formula: [Wherein, R ¹ represents an organic group having 1 or more carbon atoms, R ² represents hydrogen or a hydrocarbon having 1 or more carbon atoms, Z represents a skeleton structure portion of an active hydrogen-containing compound that can be substituted with an epoxy group, and X represents O, N, S, COO
1 represents an integer of 1 or 2, m represents an integer of 1 to 5, and n represents an integer of 1 to 3. ] An underwater coating type epoxy resin composition, characterized by using a phosphorus atom-containing epoxy compound represented by the following formula: 2. The method according to claim 1, wherein the phosphorus-containing epoxy compound is contained in 100 parts by weight of the total resin composition in terms of phosphorus atoms.
An epoxy resin composition, which is contained in an amount of 0.005 to 0.3 g equivalent.