JPH0149305B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a long-term rust-preventing coating composition that forms a film with excellent long-term rust-preventing properties on steel materials. Conventionally, paints using epoxy resin as a binder have been widely used for heavy-duty corrosion protection applications due to their excellent anticorrosion properties. However, there is a restriction in the painting process that the surface to be coated must be completely removed from rust and mill casing by sandblasting etc. before painting, so it cannot be used on existing structures or old It was extremely inconvenient to use it for repairing paint films. Therefore, a method of improving the adhesion to bad surfaces such as low-corrosion surfaces by mixing petroleum-based resins with epoxy resins has already been commonly used. In this case, the primary adhesion to bad substrates is certainly improved, but because it contains petroleum-based resin, there is a problem in that excellent corrosion resistance cannot be maintained over a long period of time. . Therefore, the present inventors focused on the moisture and corrosive substance shielding effect of the scaly pigment and the excellent corrosion resistance of lead, and found that it has sufficient adhesion to poor substrates such as low-corrosion surfaces. However, we have now completed the long-term rust-preventing coating composition of the present invention, which maintains excellent anti-corrosion properties over a long period of time. That is, in the present invention, (A) (B) Cu,
0.05 to 5% by weight of at least one of Ni or Sb
Contains, average particle size 10-100μm, average thickness 0.5
50 to 900 parts by weight of a scaly lead alloy pigment of ~3 μm and
(C) A long-term rust preventive agent comprising: (C) a base agent made by adding 5 to 100 parts by weight of a petroleum-based resin with a number average molecular weight of 500 to _2,500 obtained from C5 to _C9 fractions of petroleum; (B) a hardening agent; The present invention relates to coating compositions. The epoxy resin used in the composition of the present invention has at least two or more epoxy groups in one molecule and has an epoxy equivalent of about 150 to 3,300. Examples of suitable epoxy resins include polyhydric alcohols,
Examples include epoxy resins obtained by reacting polyvalent phenols with excess epichlorohydrin or alkylene oxide. Examples of polyhydric alcohols include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerin, neopentyl glycol, butylene glycol, hexanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerol, sorbitol, etc. Polyhydric phenols include 2,2-bis(4-hydroxyphenyl)propane (generally referred to as bisphenol A), halogenated bisphenol A,
4,4' dihydroxyphenylmethane (generally called bisphenol F), tris(4-hydroxyphenyl)propane, resorcinol, tetrahydroxyphenylethane, novolac type polyhydric phenol, cresol type polyhydric phenol, etc. It is. Examples of epoxy resins other than these that can be used in the present invention include 1,2,3-tris (2,
Glycidyl adducts of propane (3-epoxypropoxy), aniline or aniline derivatives (such as orthotoluidine), glycidyl esters such as phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, epoxidation Such as soybean oil. Any of these epoxy resins that are generally commercially available as epoxy resins for paints can be used, and they can be used alone or as a mixture of two or more. Particularly preferred are bisphenol type epoxy resins and novolak type epoxy resins. In addition, the scaly lead alloy pigment used in the present invention is
Add at least one of Cu, Ni or Sb to lead from 0.05 to 7
Particles alloyed by weight percent are added together with stearic acid, mineral spirits, etc. in the form of scales using a ball mill, etc., and the average particle size is 10~
It has an average thickness of 100 μm and an average thickness of 0.5 to 3 μm. The scaly lead alloy pigment used in the present invention can not only impart further rust prevention properties to the coating film by blocking the permeation of corrosive substances, but also impart flexibility to the coating film. Conventionally, compositions using lead in the form of flakes have been known, but by alloying lead as in the present invention, strength can be imparted to the lead particles, and as a result, the process of dispersing the pigment into the vehicle during paint manufacturing can be improved. In this way, deformation, breakage, etc. of the scaly pigment particles can be prevented. In other words, since the pigment is dispersed in the paint while maintaining an almost perfect scale-like form, the lamination effect in the paint film is further improved, and as a result, the rust prevention properties of the paint film are also improved. From this point of view, the alloying component should be 0.05% by weight.
The above is preferable, and in order not to impair the rust prevention properties of lead, it is preferably about 5% by weight or less. In the composition of the present invention, the flaky lead alloy pigment is used in an amount of 50 to 900 parts by weight based on 100 parts by weight of the epoxy resin. In the above range, if the amount of the scaly lead alloy pigment is less than 50 parts by weight, the effect of blocking the permeation of corrosive substances such as moisture will be reduced, and therefore the desired rust prevention property will not be obtained, and on the contrary, the scaly lead alloy pigment will be less than 50 parts by weight. If the lead alloy pigment exceeds 900 parts by weight, the film becomes brittle, which is not preferable. Further, the petroleum resin used in the composition of the present invention is a resin having a number average molecular weight of about 500 to 2,500 obtained from _C5 to _C9 fractions of petroleum. For example, synthetic polyterpene resin, aromatic hydrocarbon resin, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin,
Examples include unsaturated hydrocarbon resins, isoprene resins, and hydrogenated hydrocarbon resins. These resins can be used alone or as a mixture of two or more. The petroleum resin is used in an amount of 5 to 100 parts by weight based on 100 parts by weight of the epoxy resin. If the amount of petroleum-based resin is less than 5 parts by weight within this range, the desired adhesion to the base surface cannot be obtained;
If the amount exceeds 100 parts by weight, the antirust properties of the coating film will be significantly reduced, so both are not preferred. In the long-term rust-preventing coating composition of the present invention, the epoxy resin, the scaly lead alloy pigment, and the petroleum resin are mixed in a conventional manner to form a main ingredient. Incidentally, when the epoxy resin and petroleum resin are solid at room temperature, they are used after being dissolved in an organic solvent commonly used in paints. If necessary, commonly used coloring pigments, extender pigments, other anticorrosion pigments, dispersion aids, suspending agents, diluents, hardening accelerators, etc. may be added to the main ingredient. The long-term rust preventive coating composition of the present invention can be obtained by adding a curing agent to the base agent thus obtained at the time of use. As the curing agent for curing the epoxy resin of the present invention, any curing agent that is generally used as a curing agent for epoxy resins such as amine adduct resin, polyamide resin, polyamine resin, etc. may be used alone or as a mixture. These need to have at least two or more nitrogen atoms and an active hydrogen bonded to them in one molecule in order to carry out a cross-linking reaction with the epoxy resin. Particularly preferred curing agents in the present invention include amine adduct resins and polyamide resins made from aromatic amines such as m-phenylenediamine, p,p'-diaminodiphenylmethane, and p,p'-diaminodiphenylsulfone. is preferred. When the amine adduct resin or the like is used as a curing agent, the water resistance of the film can be significantly improved. The curing agent is preferably mixed in an amount of 0.8 to 1.2 active hydrogen equivalents per 1 epoxy equivalent of the epoxy resin. The thus obtained long-term rust-preventing coating composition of the present invention is applied onto steel materials by a conventional method such as brushing, roller, air spraying, etc. to a film thickness of about 20μ to 500μ, and then dried at room temperature or by heating. Ru. The film obtained after drying has excellent strength, corrosion resistance, etc. Furthermore, when applying the antirust coating composition of the present invention,
It can also be applied on top of an undercoat paint film such as a zinc-rich primer or a wash primer. Furthermore, if necessary, a top coating material such as chlorinated rubber, alkyd resin, epoxy resin, urethane resin, or acrylic resin may be applied onto the coating film obtained from the composition of the present invention. The coating film obtained from the composition of the present invention exhibits excellent adhesion to these top coatings. Thus, according to the antirust coating composition of the present invention,
It is possible to obtain a coating film with excellent long-term rust prevention properties as well as various physical properties. The details of the present invention will be explained below with reference to Examples. "Part" or "%" means "part by weight" or "% by weight"
It is shown with. Example 1 (Main agent) Epoxy resin [Epikoat 828: Ciel Chemical Co., Ltd.
Co., Ltd. product name] 60 Titanium oxide pigment 4 Organic bentonite [Penton #34: National Red Co., Ltd. product name 2 Petroleum-based resin [Quinton 1500: Nippon Zeon Co., Ltd.]
[product name] 12 xylene: 25 scaly lead alloy pigment A 30 133 parts (hardening agent) Aromatic amine adduct resin [ADEKA Hardener EH551: Asahi Denka Co., Ltd. product name] 30 parts Excluding scaly lead alloy pigment A After kneading the main ingredient composition with a roller, the flaky lead alloy pigment A was added and mixed with stirring using a disper to prepare a main ingredient. A curing agent was stirred and mixed with the base material using a disper to obtain a rust-preventive coating composition of the present invention. The flaky lead alloy pigment A is obtained by atomizing a lead alloy containing 0.1% Cu by an atomizing method.
A paste with a non-volatile content of 88.7% that is made into flakes using a ball mill with the addition of 2% stearic acid and mineral spirits, and has a particle size of 10 to 50μ. After completely removing black scale, rust, and oil from a 150 x 150 x 1.6 mm mild steel plate (JIS-G-3141) by shot blasting, the coating composition was air-sprayed to a dry film thickness of 500μ. Paint as shown, 20℃, 75
It was dried for 7 days at %RH and used for comparative tests. Example 2 (Main agent) Epoxy resin [Epikoat 1004: Ciel Chemical Co., Ltd.
Co., Ltd. product name] 50 Titanium oxide 4 Organic bentonite (same as Example 1) 2 Petroleum-based resin [Quinton 1700: Nippon Zeon Co., Ltd.]
Product name] 15 Xylene 20 Methyl isobutyl ketone 20 Scale-like lead alloy pigment B 100 211 (Curing agent) Part Amine adduct resin (same as Example) 5.8 The paint was kneaded in the same manner as Example 1, and the Example After coating and drying in the same manner as 1, it was subjected to a comparative test. The flaky lead alloy pigment B is a paste with a non-volatile content of 90.6% obtained by processing a lead alloy containing 0.1% NI in the same manner as in Example 1, and has a particle size of 10 to 50μ.
belongs to. Example 3 (Main agent) Epoxy resin (same as Example 2) 70 Titanium oxide 4 Organic bentonite (same as Example 1) 2 Petroleum resin [Nisseki Neopolymer E100: trade name manufactured by Nippon Oil Refining Co., Ltd.] 35 Methyl isobutyl ketone 25 Xylene 10 Scaly lead alloy pigment C 35 181 (Curing agent) Partially aromatic amine adduct resin [Epicure
DX-103: Trade name manufactured by Ciel Kagaku Co., Ltd.] 6 A paint was mixed in the same manner as in Example 1, painted and dried in the same manner as in Example 1, and then subjected to a comparative test. The flaky lead alloy pigment C is a paste with a non-volatile content of 91.6%, obtained by processing a lead alloy containing 1% Sb in the same manner as in Example 1, and has a particle size of 10 to 50μ. Example 4 (Main agent) Epoxy resin [Epikoat 1001: Ciel Chemical Co., Ltd.
Co., Ltd. product name] 50 Titanium oxide 4 Organic bentonite (same as Example 1) 2 Petroleum-based resin (same as Example 3) 30 Methyl isobutyl ketone 30 Xylene 20 Scaly lead alloy pigment B (same as Example 2) ) 300 436 (Curing agent) Part Amine adduct resin (same as Example 3) 9 The paint was mixed in the same manner as in Example 1, painted and dried in the same manner as in Example 1, and then subjected to a comparative test. did. Comparative Example 1 (Main agent) Part Epoxy resin (same as Example 1) 70 Petroleum resin (same as Example 1) 20 Titanium oxide 4 Organic bentonite (same as Example 1) 2 Xylene 40 Talc 70 206 (Curing agent) Aromatic amine adduct (same as Example 1) 35 A coating material was mixed in the same manner as in Example 1, painted and dried in the same manner as in Example 1, and then subjected to a comparative test. Comparative Example 2 (Main agent) Part Epoxy resin (same as Example 4) 50 Titanium oxide 4 Organic bentonite (same as Example 1) 2 Methyl isobutyl ketone 15 Xylene 15 Scaly lead alloy pigment C (same as Example 3) 200 286 (Curing agent) Partially aromatic amine adduct resin (same as Example 3) 9 After kneading the paint in the same manner as in Example 1, painting and drying in the same manner as in Example 1, it was subjected to a comparative test. did.

[Table] From the above comparative test results, it is clear that the coating obtained from the coating composition of the present invention exhibits excellent effects in rust prevention, adhesion, crack resistance, etc. On the other hand, the films obtained from the compositions of Comparative Example 1, which does not contain a scaly lead alloy pigment, or Comparative Example 2, which does not contain a petroleum-based resin, are clearly unsuitable as long-term rust prevention films. It shows.

Claims (1)

[Scope of Claims] 1 (A) (B) For 100 parts by weight of epoxy resin, (B)
50 to 900 parts by weight of a scaly lead alloy pigment containing 0.05 to 5% by weight of at least one of Cu, Ni, or Sb, an average particle size of 10 to 100 μm, and an average thickness of 0.5 to 3 μm, and (c) petroleum C ₅ ~ A long-term rust-preventing coating composition comprising: a main agent containing 5 to 100 parts by weight of a petroleum resin having a number average molecular weight of 500 to 2,500 obtained from _C9 fraction; and (B) a curing agent.