JPS6143109B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anticorrosion coating method for forming a tough coating with excellent corrosion resistance on a coated object, particularly steel. BACKGROUND ART Conventionally, resin linings for the purpose of preventing corrosion and rust of metals have been widely used in various pollution prevention devices and chemical equipment, as well as tanks, oil tanks of ships, ship bottoms, and the like. Unsaturated polyester resin is used as the resin for these resin linings due to its room temperature curability, on-site workability, cost, etc.
The lining method is FRP lining, i.e., before lining construction, resin is mixed with organic peroxide, a sheet-like base material made of glass fiber is applied to the base material to be lined, and the resin is applied with a felt roll or the like. A commonly used method is to impregnate the material, simultaneously defoaming it, and curing it. In addition to this method, a method that has recently been attracting attention is a method in which, instead of glass fiber, a composition made by blending extremely thin glass flakes with resin is applied onto the object using a trowel or the like (flake lining).
, and some of them have already been put into practical use. For example, such compositions include protective and decorative coating compositions containing fine glass flakes in an organic resin binder vehicle (Japanese Patent Publication No. 51-25368), or as corrosion-resistant coating compositions in a lining resin. Lining material filled with glass flakes and glass fibers as reinforcing material
30855), etc. are known. In addition, by treating the surface of flaky glass with an appropriate substance, it can be given hydrophobicity and leafing properties, and plastics, paints, insulating paper, etc.
-16821) is also known. However, in consideration of various performance aspects of the coating, the construction of the above compositions requires extremely thick films of 2 mm or more, and in addition, the construction cost is very high, so it is not suitable for general steel structures. The reality is that it is not applied and is used for very limited special purposes as described above. Furthermore, if flake lining, which is currently used as a lining material, was used in a thin film of 2 mm or less in consideration of cost, it would not be possible to obtain the desired film performance and it would be completely impractical. In short, the problem with compositions using such glass flakes was how to arrange the glass flakes parallel to the base surface in order to take advantage of their characteristics and suppress the permeation of corrosive ions. By the way, conventional flake lining using glass flakes has been promoted by smoothing the coating surface with a trowel or roller during construction to promote alignment of the glass flakes in the coating. However, construction methods using trowels or rollers have the drawbacks of high processing costs and difficulty in constructing structures with complex shapes. Therefore, a sprayable glass flake-containing composition has been proposed that solves such construction difficulties. (For example, U.S. Pat. No. 3,653,954) However, even if the composition is spray-painted, the glass flakes do not align parallel to the substrate surface, and they vary depending on the coating direction. The effect of suppressing the permeation of sexual ions could not be expected much. Therefore, as mentioned above, a coating method and composition in which the glass flakes are arranged substantially parallel to the substrate surface have not been known in fact. Furthermore, one of the problems with conventionally known unsaturated polyester resins is that they are cured by radical polymerization, which inhibits the curing of the surfaces in contact with air. Therefore, a method of adding paraffin wax or the like has been proposed. In other words, the mechanism is that the added paraffin wax is pushed out onto the coating surface during curing, and the surface hardens by cutting off the air, but this mechanism is very uncertain and depends on the conditions at the time of painting. It has the disadvantage that it is easily influenced by In addition, there are other types of resins in which styrene evaporates without the addition of paraffin wax, resulting in an apparent surface dryness. However, since the surface layer of this type of material is not substantially cross-linked, it swells and deteriorates when exposed to environmental liquids such as hot water, resulting in a choking appearance, which not only gives a poor appearance but also coats the inner surface of tanks, etc. In the case of membranes, there is a risk of contaminating the contents, and there are various other drawbacks, making them very inconvenient. In addition, in the above method of adding paraffin wax, if paraffin wax was added and it floated sufficiently on the surface, there would be less fatal problems, but in any case, wax floating on the surface However, there was a problem of delamination, and it was virtually impossible to recoat the film, making it unsuitable for cases where thick films needed to be recoated or where repairs were required. Furthermore, it is very difficult to properly control the floating of the paraffin wax, and depending on the operating conditions, the floating may become insufficient, resulting in non-uniform hardening. Furthermore, as a paint having sufficient surface drying properties without adding paraffin wax, an unsaturated polyester resin obtained by reacting a polybasic acid, a polyhydric alcohol, and a polyhydric alcohol allyl ether is used as an air-drying paint. It is widely used for painting furniture, interior materials, household goods, etc. However, this type of resin has inferior corrosion resistance compared to conventional unsaturated polyester resins for heavy corrosion protection, and cannot be used for heavy corrosion protection. The present invention aims to eliminate or improve the drawbacks of the prior art as described above. More specifically, by spray painting, glass flakes are arranged almost parallel to the base surface of the object to be coated, resulting in excellent rust prevention, adhesion to the base, adhesion to the top coat, and weather resistance. The present invention relates to an anticorrosive coating method that provides a durable coating. That is, the present invention provides: (1) an epoxy resin-modified unsaturated polyester resin in which an unsaturated polyester having an allyl ether group and a carboxyl group is bonded to an epoxy group in a bifunctional bisphenol A type epoxy resin;
…………100 parts by weight, glass flakes with a thickness of 0.5 to 10 microns and a size of 100 to 400 microns …………10 to 70 parts by weight, ketone peroxide 0.1 to 2.0 parts by weight, hydroperoxide and/or peroxide A composition consisting of 0.5 to 2.0 parts by weight of oxyester was sprayed into a spray tip with a diameter of
Paint film thickness 300~ using a 0.5~3mm spray gun
An anticorrosive coating method characterized by spray painting to a thickness of 1500 microns, and (2) an epoxy group in a bifunctional bisphenol A type epoxy resin, (a) an unsaturated polyester having an allyl ether group and a carboxyl group, (b)
Epoxy resin-modified unsaturated polyester bound with acrylic acid or methacrylic acid
…………100 parts by weight, glass flakes with a thickness of 0.5 to 10 microns and a size of 100 to 400 microns …………10 to 70 parts by weight, ketone peroxide
A composition consisting of …………0.1 to 2.0 parts by weight and hydroperoxide and/or peroxy ester …………0.5 to 2.0 parts by weight is coated using a spray gun with a spray tip diameter of 0.5 to 3 mm. An anti-corrosion coating method characterized by spray painting to a thickness of 300 to 1500 microns. Regarding. The epoxy resin-modified unsaturated polyester resin used in the coating method of the present invention is (1) an unsaturated polyester having an allyl ether group and a carboxyl group in the epoxy group in the bifunctional bisphenol A type epoxy resin ( below,
(abbreviated as allyl ether group-containing unsaturated polyester) and a polymerizable monomer, or (2) an epoxy group in a difunctional bisphenol A type epoxy resin. It consists of an epoxy resin-modified unsaturated polyester obtained by combining an allyl ether group-containing unsaturated polyester with acrylic acid or methacrylic acid (hereinafter abbreviated as (meth)acrylic acid) and a polymerizable monomer. In the above, the content of the epoxy resin-modified unsaturated polyester is usually 45 to 65% by weight. In the composition of the present invention, by using the former epoxy resin-modified unsaturated polyester resin (1), it is possible to obtain a coating film that is recoatable and has excellent corrosion resistance and coating hardness. Furthermore, by using the latter epoxy resin-modified unsaturated polyester resin, in addition to the above-mentioned properties, the gelation rate of the coating film and, by extension, the air drying properties can be significantly improved. Said bifunctional bisphenol A in the present invention
Type epoxy resin (hereinafter simply referred to as epoxy resin) is a compound having the following structural formula. In this formula, n is usually appropriately selected from the range of 0 to 3. In addition, the epoxy equivalent of the epoxy resin is approximately
It ranges from 100 to 500, preferably about 180 to 300.
In the above range, if the epoxy equivalent is less than about 100, the glass transition temperature will be too low and the drying rate will tend to decrease. On the other hand, if it is about 500 or more, the functional group equivalents of allyl ether groups and (meth)acryloxy groups become too low when producing the unsaturated polyester of the present invention, and the curing rate decreases, which is also not preferred. The allyl ether group-containing unsaturated polyester used in the present invention must contain a free carboxyl group in its molecule, and the carboxyl group reacts with the epoxy group in the epoxy resin. Such unsaturated polyesters can be produced by any method. Generally, an allyl group-containing unsaturated polyester in which at least one free carboxyl group remains in the molecule is prepared by condensing polybasic acids, polyhydric alcohols, and polyhydric alcohol allyl ethers. As the polybasic acid, unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid, cistraconic acid, and anhydrides thereof are used, and if necessary, phthalic acid, isophthalic acid, terephthalic acid, and hettic acid are used. Saturated polybasic acids such as , adipic acid, sebacic acid, succinic acid, azelaic acid, and anhydrides thereof can also be used in combination. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, trimethylolethane, trimethylolpropane, dihydroxypentadiene, pentaerythritol, diglycerin, ditrimethylolpropane, and the like. Examples of polyhydric alcohol allyl ethers include glycerin monoallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, trimethylolethane monoallyl ether, trimethylolethane diallyl ether, pentaerythritol monoallyl ether, pentaerythritol diallyl ether, and pentaerythritol diallyl ether. Erythritol triallyl ether, 1.
Examples include 2,6-hexanetriol monoallyl ether, 1,2,6-hexanetriol diallyl ether, sorbitan monoallyl ether, sorbitan diallyl ether, and the like. However, these compounds are merely examples, and the present invention is not limited to these compounds. Furthermore, the allyl ether group-containing unsaturated polyester is not necessarily limited to the above-mentioned composition, but may contain a polybasic acid, preferably an unsaturated polycarboxylic acid such as maleic anhydride or fumaric acid, and at least one polyester in the molecule. Even low-molecular compounds such as partially esterified products with polyhydric alcohol allyl ether having a hydroxyl group can be used. The desired epoxy resin-modified unsaturated polyester can be obtained by reacting the allyl ether group-containing unsaturated polyester with an epoxy resin. Specifically, for example, an allyl group-containing unsaturated polyester is prepared in advance, and an epoxy resin is mixed therein and reacted. In addition, during the reaction of polybasic acid, polyhydric alcohol, and polyhydric alcohol allyl ether, which are the raw materials for the unsaturated polyester, to produce an allyl ether group-containing unsaturated polyester in the system, an epoxy resin is further mixed with this. hand,
Methods such as continuing the reaction may also be taken as appropriate. During this reaction, a small amount of 2-hydroxyethyl p-toluidine, 2-methylimidazole, trimethylbenzylammonium chloride, etc. is added as a catalyst. The reaction temperature ranges from 50 to 90°C, preferably from 60 to 70°C. In the present invention, by reacting the allyl ether group-containing unsaturated polyester with the epoxy resin as described above, the bisphenol skeleton, allyl ether group,
An unsaturated acid double bond based on an unsaturated polybasic acid such as maleic anhydride will be present. However, due to the presence of these three components, the performance of conventional air-drying paints is not reduced, and
Corrosion resistance, coating hardness, etc. can be significantly improved. In the above epoxy resin-modified unsaturated polyester, the epoxy resin component is
The purpose can be sufficiently achieved if the content is 20 to 80% by weight, but the anticorrosion property is more preferably exhibited in the range of 50 to 70% by weight. The epoxy resin component
When the amount is less than 20% by weight, there is a tendency for the hardness of the coating film to decrease. On the other hand, if it is used in an amount exceeding 80% by weight, the viscosity becomes too high and a practical problem remains. In addition, the allyl ether group is 5 to 5 for the total polymer.
Selected from a range of 20% by weight. In the present invention, in addition to the allyl ether group-containing unsaturated polyester, when (meth)acrylic acid is further bonded to the epoxy group in the epoxy resin, the coating film is improved compared to when the allyl ether group-containing unsaturated polyester is used alone. In other words, an epoxy resin-modified unsaturated polyester with excellent air-drying properties is obtained. As for the reaction, the carboxyl group in the molecule of (meth)acrylic acid also reacts with the epoxy group in the epoxy resin and bonds to it. In the present invention, in order to bond an allyl ether group-containing unsaturated polyester and (meth)acrylic acid with an epoxy resin, the allyl ether group-containing unsaturated polyester is usually first produced by the various methods described above, and then the epoxy Resin and (meta)
A method is used in which acrylic acid is reacted at a temperature of 70 to 110°C. Other methods include a method in which an epoxy resin and an allyl ether group-containing unsaturated polyester; or a method in which an epoxy resin and (meth)acrylic acid are first reacted; and then the remaining one component is reacted. However, the present invention is not limited to these methods. In the above, it is desirable that (meth)acrylic acid be present in an amount of 5 to 50% by weight based on the total polymer. The molecular weight of the epoxy resin-modified unsaturated polyester of the present invention thus obtained is about 1000 to
A range of 3000, more preferably about 1500 to 2500 is suitable. In the above, when the molecular weight becomes 1000 or less,
The coating viscosity is too low and the curing speed decreases. Also about
If it is more than 3,000, the viscosity is too high and the desired coating viscosity cannot be achieved unless a large amount of styrene or the like is used, resulting in a decrease in the curing rate, which is similarly undesirable. In the present invention, the polymerizable monomers used together with the epoxy resin-modified unsaturated polyester include styrene, vinyltoluene, chlorostyrene, α-methylstyrene, divinylbenzene,
(meth)acrylic acid ester, glycidyl methacrylate, vinyl acetate, diallyl phthalate,
Triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tung oil, linseed oil, soybean oil,
Examples include cottonseed oil, safflower oil, and coconut oil. The polymerizable monomer is added after producing the epoxy resin-modified unsaturated polyester so that the solid content is about 45 to 65% by weight, as described above. Furthermore, if necessary, to adjust the viscosity of the composition, etc.
It may also be used as a reactive diluent. Further, the glass flakes used in the anticorrosion coating method of the present invention are extremely thin flat shaped glass flakes having an average thickness of 0.5 to 10 microns, preferably 1 to 5 microns, and an average size of 100 to 400 microns, preferably 150 to 300 microns. particles. The glass flakes are layered in parallel to the material within the coating, increasing the strength of the coating and at the same time preventing the permeation of steam, moisture and other corrosive substances from the outside.
Shows the action (effect) of preventing penetration. If the thickness of the glass flakes is less than 0.5 microns, the strength of the glass flakes is so low that they cannot be used practically. Conversely, if it is thicker than 10 microns, it tends to be difficult to align parallel to the substrate. Also, in terms of the size of the glass flakes, it is
If it is smaller than 100 microns, it will be difficult to arrange it parallel to the substrate, and the strength and corrosion resistance of the coating will not improve. On the other hand, glass flakes with a size exceeding 400 microns are similarly undesirable because they impede spray workability. The mixing ratio of the epoxy resin-modified unsaturated polyester resin and the glass flakes in the present invention is 100 parts by weight of the resin to 10 parts by weight of the glass flakes.
A range of 70 parts by weight (particularly preferably 20 to 60 parts by weight) is suitable from the viewpoint of corrosion resistance and physical properties of the coating film. If the amount of glass flakes is less than 10 parts by weight in the above mixing ratio, the desired corrosion resistance cannot be obtained. On the other hand, if it exceeds 70 parts by weight, the flexibility of the film decreases and it becomes brittle, both of which are not preferred. Next, in the present invention, ketone peroxide is used. As the ketone peroxide, methyl ethyl ketone peroxide is suitable. Further, in the present invention, hydroperoxide and/or peroxy ester are used. Examples of the hydroperoxide include t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane, etc. . Particularly preferred is cumene hydroperoxide and t-butyl hydroperoxide. These may be used alone or as a mixture of two or more. Furthermore, peroxy esters include t-butyl peroxy phthalate, t-butyl peroxybenzoate, t-butyl peroxy laurate,
Examples include t-butylperoxy 2-ethylhexanoate, t-butylperoxybivalate, t-butylperoxyacetate, t-butylperoxyisobutyrate, and especially t-butylperoxyphthalate, t-butylperoxyisobutyrate, and the like. Preference is given to using butyl peroxylaurate. These may be used alone or as a mixture of two or more. In the present invention, ketone peroxide and
The use of a combination of hydroperoxides and/or peroxy esters controls the pot life of the composition, ie, the cure time of the coating.
As a result, the glass flakes become parallel in the sprayed coating film, making it possible to form a layer of glass flakes arranged parallel to the substrate. Therefore, the amounts of ketone peroxide, hydroperoxide and/or peroxy ester to be added are determined from the viewpoint of the above-mentioned actions (effects). However, the amount of these compounds used is easily influenced by the outside temperature at the time of coating. According to experiments conducted by the present inventors, ketone peroxide is produced by epoxy resin-modified unsaturated polyester resin.
For 100 parts by weight, when the temperature is 5℃, it is about 1.0 parts by weight, when the temperature is 20℃, it is about 0.4 parts by weight, and 30 parts by weight.
℃, it has been found that an amount of approximately 0.1 part by weight is preferable. Hydroperoxide and/or peroxy ester is about 1.5 parts by weight when the temperature is 5°C, and about 1.1 parts by weight when the temperature is 20°C, per 100 parts by weight of the epoxy resin-modified unsaturated polyester resin. It has been found that when the temperature is 30°C, the addition amount is preferably around 1.4 parts by weight. The amount of those added at each temperature is
If the amount added is too large, the pot life will be shortened and painting operations will become difficult. In addition, since the coating film hardens in a short time, parallel alignment of glass flakes is less likely to occur. On the other hand, if the amount added is less than the above amount, the drying time will be too long, which is inappropriate. In the present invention, it is essential to use ketone peroxide and hydroperoxide and/or peroxy ester in combination. The former contributes to the radical reaction of the epoxy resin-modified unsaturated polyester resin, but when used alone, the curing reaction is too rapid, making it difficult to arrange glass flakes in parallel. Therefore, in order to control radical reactions at room temperature, hydroperoxide and/or peroxy ester are added to this to promote parallel alignment of glass flakes. Further, hydroperoxide and/or peroxy ester do not contribute to the curing reaction in a short time, but gradually decompose over a long period of time, proceeding with the crosslinking reaction and increasing the strength of the coating film. Therefore, they are essentially different in that curing is controlled by hydroquinone, catechol, etc., which are usually used as curing retarders. In this way, a composition used in the method of the present invention is obtained, and if necessary, the composition contains a curing accelerator, a coloring pigment, an extender pigment, an anticorrosive pigment, a suspending agent, a dispersant, a diluent, and other substances. It is possible to add flat pigments and the like. In the present invention, the composition thus obtained is applied to the object to be coated by spray coating. Suitable spray methods include pressurized air spray, airless spray, and the like. Air pressure of 4Kg/cm2 or ^more for forced air spray, primary air pressure of 5Kg/cm2 ^or more for airless spray, compression ratio
Coating conditions of 30:1 or more and a spray tip diameter of 0.5 to 3 mm (particularly preferably 0.75 to 2 mm) are suitable. In the above case, if the spray tip diameter is smaller than 0.5 mm, glass flakes will clog the tip, making it impossible to perform a smooth painting job. On the other hand, if the spray tip diameter is larger than 3 mm, the spray pattern will spread poorly and is inappropriate. In the method of the present invention, the coating method as described above is used to coat the object to be coated so that the dry coating thickness is about 300 to 1500 microns (preferably 500 to 1200 microns). In the above range, the coating film thickness is
If it is thinner than 300 microns, it is not preferable because not only the anti-corrosion properties of the coating film decrease, but also the parallel arrangement of glass flakes in the coating film is difficult to occur. On the other hand, if the coating film is thicker than 1500 microns, the coating will sag and it will be difficult to obtain a normal coating. After application, the coating composition is dried at room temperature to form a coating film. As mentioned above, by spray painting a specific composition under specific conditions, the glass flakes in the composition become aligned parallel to the substrate in the coating film. Therefore, the obtained coating film has excellent corrosion resistance, chemical resistance, weather resistance, adhesion, strength, etc. Furthermore, if necessary, chlorinated rubber, alkyd resin, epoxy resin,
A top coat of urethane resin, acrylic resin, fluororesin, etc., or a top coat of unsaturated polyester resin and glass flakes may be applied. The coating film obtained by the method of the present invention also exhibits excellent adhesion to these top coatings. The details of the present invention will be explained below with reference to Examples and Comparative Examples. Example 1 Blend 1. (Main ingredient) Part by weight Epoxy resin modified unsaturated polyester resin A37 Organic bentonite [Bentone #34: Product name manufactured by National Red Co., Ltd.] 2.0 Styrene 35.5 Cobalt naphthenate (contains 6% metallic cobalt)
0.5 Glass flakes [acid-resistant alkali-containing glass, average size 150-200 microns, average thickness 3-5 microns] 15 Talc 5 Titanium dioxide 5 100.0 (Curing agent) Methyl ethyl ketone peroxide 0.1 Cumene hydroperoxide 0.3 Modified with the above epoxy resin Unsaturated polyester resin A was obtained as follows; 0.45 mol of glycerin monoallyl ether, 1.0 mol of maleic anhydride, and 0.5 mol of ethylene glycol were charged and reacted at a temperature of 180°C for 6 hours to form a resin containing allyl ether groups. An unsaturated polyester was obtained. To this, 0.5 mole of bisphenol A diglycidyl ether was added as an epoxy resin component, and
Add 0.3% of 2-hydroxy para-toluidine and react at 90°C for 1 hour, add 2.5% methanol to the total system, react for another 1 hour, and then react at 90°C for 1 hour.
After depressurizing at mmHg for 30 minutes, styrene was added to give a solid content of 60%, an acid value of 18 mgKOH/g, and a viscosity of
An epoxy resin-modified unsaturated polyester resin of 3000 cps and an epoxy resin component content of 60% based on the total polymer was obtained. Epoxy resin-modified unsaturated polyester resin A was prepared by adding 0.03% of hydroquinone as a polymerization inhibitor to this resin. Mixing the epoxy resin-modified unsaturated polyester resin in the main ingredient of Formulation 1 and organic bentonite,
After kneading with a roller, other ingredients were added and stirred with a disper to create a base ingredient. After sandblasting a 150 x 50 x 1.6 mm mild steel plate (JIS-G-3141) to completely remove black scale, rust, and oil, the above composition 1 was prepared.
A paint containing a curing agent added to the main ingredient was applied using an airless sprayer (chip diameter 1 mm) to a dry film thickness of 500±50 microns, dried at 20°C for 7 days, and then subjected to a comparative test. Example 2 Blend 2 (Main ingredient) Part by weight Epoxy resin modified unsaturated polyester resin B40 Organic bentonite (same as Example 1) 1.5 Styrene 13 Cobalt naphthenate (same as Example 1) 0.5 Glass flakes (same as Example 1) ) 25 Talc 15 Titanium dioxide 5 100.0 (Curing agent) Methyl ethyl ketone peroxide 0.15 t-butyl peroxyphthalate 0.3 The epoxy resin-modified unsaturated polyester resin B was obtained as follows; Diallylpentaerythritol 0.45 mol , maleic anhydride 1.0 mol, phthalic anhydride 0.2 mol at temperature
0.5% of acrylic acid was added to the allyl ether group-containing unsaturated polyester obtained by reacting at 60°C for 2 hours.
Mol, bisphenol A diglycidyl ether
0.5 mol of 2-hydroxyethyl para-toluidine and 0.3% of the total system were charged at once and heated to 90°C.
After reacting for 10 hours at
After vacuum treatment for 30 minutes at
An epoxy resin-modified unsaturated polyester resin was obtained in which the contents of the epoxy resin component and the acrylic component relative to the total polymer were 10% and 50%, respectively. Epoxy resin-modified unsaturated polyester resin B was obtained by adding 0.03% of hydroquinone to this. Next, it was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Example 3 Blend 3. (Main ingredient) Part by weight Epoxy resin modified unsaturated polyester resin C50 Organic bentonite (same as Example 1) 1.0 Styrene 23.5 Cobalt naphthenate (same as Example 1) 0.5 Glass flakes (same as Example 1) Same) 20 Titanium dioxide 5 100.0 (Curing agent) Methyl ethyl ketone peroxide 0.3 t-butyl peroxyphthalate 0.7 The epoxy resin-modified unsaturated polyester resin C was obtained as follows; Diallylpentaerythritol 0.45 mol , 0.5 mole of methacrylic acid, 0.5 mole of bisphenol A diglycidyl ether, and an allyl ether group-containing unsaturated polyester obtained by reacting 1.0 mole of maleic anhydride and 0.3 mole of ethylene glycol at a temperature of 60°C for 2 hours. 0.3% amount of 2 for the whole system
-Hydroxyethyl para-toluidine was charged all at once and reacted at 90°C for 10 hours, then cooled to 60°C, 2% methanol was added to the total system, and the reaction was further continued for 1 hour.
After depressurizing at 10 mmHg for 30 minutes, styrene was added to give a solid content of 60%, acid value of 17 mgKOH/g, and viscosity.
An epoxy resin-modified unsaturated polyester resin of 3500 cps and a content of epoxy resin component and acrylic component of the total polymer of 45% and 17%, respectively, was obtained.
Epoxy resin-modified unsaturated polyester resin C was obtained by adding 0.03% of hydroquinone to this. Next, it was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Example 4 Blend 4. Part by weight Epoxy resin modified unsaturated polyester resin D37 Organic bentonite (same as Example 1) 2.0 Styrene 35.5 Cobalt naphthenate (same as Example 1) 0.5 Glass flakes (same as Example 1) 20 Titanium dioxide 5 100.0 (curing agent) Methyl ethyl ketone peroxide 0.1 Cumene hydroperoxide 0.3 The epoxy resin-modified unsaturated polyester resin D was obtained as follows; diallyl pentaerythritol 0.45 mol, maleic anhydride 1.0 mol 0.5 mole of acrylic acid, 0.5 mole of bisphenol A diglycidyl ether, and 0.3% of the total system of 2- Hydroxyethyl para-toluidine was charged all at once and reacted at 90°C for 10 hours, then cooled to 60°C, 2% methanol was added to the total system and reacted for another hour, and after vacuum treatment at 10 mmHg for 30 minutes, styrene was added. Solid content: 60%, acid value: 13
An epoxy resin-modified unsaturated polyester resin was obtained with mgKOH/g, a viscosity of 2500 cps, and an epoxy resin component and an acrylic component content of 50% and 15%, respectively, based on the total polymer. This includes 0.03% hydroquinone.
was added to obtain epoxy resin-modified unsaturated polyester resin D. Next, it was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Example 5 Blend 5. (Main ingredient) Part by weight Epoxy resin modified unsaturated polyester resin E50 Organic bentonite (same as Example 1) 1.0 Styrene 23.5 Cobalt naphthenate (same as Example 1) 0.5 Glass flakes (same as Example 1) Same) 20 Titanium dioxide 5 100.0 (Curing agent) Methyl ethyl ketone peroxide 0.3 t-Butyl peroxyphthalate 0.7 The epoxy resin-modified unsaturated polyester resin E was obtained as follows; Maleic anhydride and triallyl To 0.45 mol of a partial ester with pentaerythritol, 0.5 mol of acrylic acid, 0.5 mol of bisphenol A diglycidyl ether, and 0.3% amount of 2 to the total system.
-Hydroxyethyl para-toluidine was charged all at once and reacted at 90°C for 10 hours, then cooled to 60°C, 2% methanol was added to the total system, and the reaction was further continued for 1 hour.
After depressurizing at 10 mmHg for 30 minutes, styrene was added to give a solid content of 65%, acid value of 5.0 mgKOH/g, and viscosity.
An epoxy resin-modified unsaturated polyester resin of 3700 cps and a content of epoxy resin component and acrylic component of the total polymer of 54% and 15%, respectively, was obtained.
Epoxy resin-modified unsaturated polyester resin E was obtained by adding 0.03% of hydroquinone to this. Next, it was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Comparative Example 1 Blend 6. (Main ingredient) Part by weight Isophthalic acid-based unsaturated polyester resin [Rigorak 150HR: trade name manufactured by Showa Kobunshi Co., Ltd.] 50 Organic bentonite (same as Example 1) 2.5 Styrene 22 Cobalt naphthenate ( Same as Example 1) 0.5 Glass flakes (acid-resistant alkali-containing glass, average particle size 40 microns, average thickness 3-5 microns)
20 Titanium dioxide 5 100.0 (Curing agent) Methyl ethyl ketone peroxide 1.5 The above formulation 6 was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Comparative Example 2 Blend 7. (Main ingredient) Part by weight Isophthalic acid-based unsaturated polyester resin (same as Comparative Example 1) 45 Organic bentonite (same as Example 1) 2.5 Styrene 21.7 Cobalt naphthenate (same as Example 1) 0.8 Glass flakes (same as Example 1) 25 Titanium dioxide 5 100.0 (Curing agent) t-Butyl peroxybenzoate 2.0 The above formulation 7 was made into a paint in the same manner as in Example 1, and a test piece was prepared and subjected to a comparative test. Regarding the coating films obtained in Examples 1 to 5 and Comparative Examples 1 to 2, hardness, corrosion resistance, adhesion, weather resistance,
Table 1 shows the results of comparative tests such as water resistance.

[Table] From Table 1 above, it goes without saying that the coating film obtained by the method of the present invention has much improved rust prevention properties compared to the coating film obtained using the conventional composition. It is clear that it exhibits excellent performance in terms of adhesion, weather resistance, chemical resistance, etc.

Claims (1)

[Scope of Claims] 1. An epoxy resin-modified unsaturated polyester resin in which an unsaturated polyester having an allyl ether group and a carboxyl group is bonded to an epoxy group in a bifunctional bisphenol A type epoxy resin.
…………100 parts by weight Glass flakes with a thickness of 0.5 to 10 microns and a size of 100 to 400 microns …………10 to 70 parts by weight Ketone peroxide …………0.1 to 2.0 parts by weight Hydroperoxide and/or An anti-corrosion coating characterized by spray painting a composition comprising 0.5 to 2.0 parts by weight of peroxyester to a coating thickness of 300 to 1500 microns using a spray gun with a spray tip diameter of 0.5 to 3 mm. Method. 2. Claim 1, wherein the unsaturated polyester having an allyl ether group and a carboxyl group is a partial esterification product of an unsaturated polybasic acid or its anhydride and a polyhydric alcohol allyl ether having one hydroxyl group. The anti-corrosion coating method described. 3. The anticorrosive coating method according to claim 2, wherein the unsaturated polybasic acid or its anhydride is maleic anhydride. 4 An epoxy resin-modified unsaturated polyester in which (a) an unsaturated polyester having an allyl ether group and a carboxyl group, and (b) acrylic acid or methacrylic acid are bonded to the epoxy group in a bifunctional bisphenol A type epoxy resin.
…………100 parts by weight, glass flakes with a thickness of 0.5 to 10 microns and a size of 100 to 400 microns …………10 to 70 parts by weight, ketone peroxide
A composition consisting of …………0.1 to 2.0 parts by weight and hydroperoxide and/or peroxy ester …………0.5 to 2.0 parts by weight is coated using a spray gun with a spray tip diameter of 0.5 to 3 mm. An anti-corrosion coating method characterized by spray painting to a thickness of 300 to 1500 microns. 5. Claim 4, wherein the unsaturated polyester having an allyl ether group and a carboxyl group is a partial esterification product of an unsaturated polybasic acid or its anhydride and a polyhydric alcohol allyl ether having one hydroxyl group. The anti-corrosion coating method described. 6. The anticorrosive coating method according to claim 5, wherein the unsaturated polybasic acid or its anhydride is maleic anhydride.