JP2003306634A - Anticorrosive coating composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anticorrosive coating composition imparting an optional color to the finish of a coated film surface without cracking or exposing a color tone of a filler on the coated film surface even when the filler such as glass cullet powder or disposed PET bottle powder is used. <P>SOLUTION: The anticorrosive coating composition comprises 100 pts.wt. of a liquid composition prepared by dissolving an acrylic resin in a solvent, 100-400 pts.wt. of glass powder or rigid resin powder and 5-20 pts.wt. of titanium oxide powder. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for anticorrosion, more specifically, a composition obtained by mixing a liquid composition in which an acrylic resin is dispersed with glass powder and / or hard resin powder, which is industrial waste. By coating objects on the surface of steel plates, steel pipes or concrete structures, the anticorrosion effect is comparable to coating materials such as epoxy resin, polyethylene resin, and vinyl chloride resin that have been used as anticorrosion paints. And, as an advantage, the present invention relates to a coating composition for anticorrosion capable of finishing the glossiness of the surface to any color including white.

[0002]

2. Description of the Related Art Conventionally, as corrosion-prevention means for iron products, galvanization or colored coating is applied to steel plates, tin plating is applied to tin plates, and zinc plating, epoxy resin or polyethylene resin is applied to steel pipes. The method of coating the outer surface with a vinyl chloride resin has been widely used for many years, and is still used as a mainstream technology. On the other hand, for glass waste and pet bottles as industrial waste, there has been no suitable means other than incineration or recycling as industrial waste treatment. However, although recycling and recycling are still widely used treatment methods, there is a drawback in that the quality cannot be restored to the original quality even with a glass carette or a pet bottle. Under the present circumstances, the two problems mentioned heretofore have been treated as completely different technical problems, that is, a corrosion prevention treatment method and an industrial waste treatment method.

Recently, however, regulations on industrial waste have become more stringent, and penal regulations have been strengthened. Particularly, regarding the disposal of pet bottles, it is an urgent task to take measures as a serious problem faced by each local government. I was crying. For this reason, we have shifted from incineration, which has been widely used in the past, to the point of recycling resources, and thoroughly wash and separate PET bottles into pure polyethylene terephthalate (PET) flakes, which are then used as raw materials. The emphasis has shifted to so-called recycling, which creates various products. As is well known, most pet bottles are for soft drinks, and at present, more than 2 billion bottles are digested and discarded every year. The same is true for glass bottles. That is, glass bottles have been used repeatedly for quite a long time in the form of recycling prior to PET. However, it is impossible to remove the original color of a glass bottle because it uses metal for its color development. Further, the glass bottle has a drawback that when a foreign material, for example, a different type of glass carret such as heat-resistant glass is mixed, the recycled glass bottle is easily broken and discolored.

As described above, at present, enormous costs have been spent on the recycling and recycling of both pet bottles and glass carlets. In view of such circumstances, the present inventor has long sought a method of using the industrial waste at a low cost, and in a state of pulverizing and mixing them, as a result, as a result, conventionally, a pet bottle or a glass carette is Each of them has been used in a different treatment method, and each of them has been used for a different purpose.However, the present inventor has noticed that the above-mentioned industrial waste substances have excellent performance in corrosion resistance, and made fine powder of this. It has been completed through intensive studies to mix it with a specific paint and use it for the surface coating of iron products that are prone to rust, especially steel pipes. By the way, as for the corrosion prevention method for iron products, the technique of zinc plating and tin plating has already been completed, but the small diameter electric resistance welded pipes are zinc plated or vinyl chloride coated, medium diameter electric resistance welded pipe and large diameter electric resistance welded pipe. For electric resistance welded pipes and seamless pipes, application means are still widely used, and methods such as epoxy resin coating and polyethylene film adhesive bonding are used. Also, for ordinary pipes, if you put it in the zinc plating bath as it is, a primitive method is performed,
Although not necessarily advantageous in terms of cost, the corrosion resistance is far superior to the commonly used synthetic resin paint coating.

[0005]

However, in view of the current situation that the conventional techniques have various problems as described above, the industrial waste is industrial waste, and the anticorrosion is a disposal method or a treatment method as anticorrosion. The inventor focused on rustable iron products as a target from the viewpoint of positively and effectively utilizing industrial waste rather than simply recycling industrial waste in order to find a contact point between the two, and the finish of the coating surface is white, yellow, green, It is an object of the present invention to provide to the market a coating composition for anticorrosion, which can be adjusted to a color such as gray and has a corrosion resistance comparable to that of a conventional resin coating. However, in the case of such a filler, that is, a resin mixture containing a glass powder or a pet powder, when it is attempted to obtain sufficient adhesiveness with the substrate, not to mention the performance of the coating film itself, the resin The degree of the above-mentioned powder to be dispersed, the mixing ratio, the thickness of the coating film, and the like are subtly related. To increase the corrosion resistance, a large amount of filler must be blended, and if a large amount of filler is blended, the coating film loses flexibility and cracks occur in the coating film. Even if these problems are solved, the color tone of the colored glass is exposed as it is on the surface of the coating film, resulting in a markedly poor commercial value. It is an object of the present invention to provide means for resolving the contradictions that are difficult to achieve at the same time. The present inventor has already mixed the acrylic resin used in the present invention with ultrafine powder of granulated blast furnace slag having a composition similar to that of glass powder to give a resin composition exhibiting effective performance in a specific application field. (Japanese Patent Laid-Open No. 10-7867)

[0006]

Under the circumstances, as a result of intensive investigations by the present inventors, as a result of dispersing a specific resin having a three-dimensional network structure and a polymerization degree of several hundred thousand, In the liquid composition, a coating composition obtained by mixing the filler and titanium oxide powder in a specific amount has excellent corrosion resistance,
The inventors have found that the coating film is less likely to be cracked and that the finish of the coating film can be colored in an arbitrary color to provide an anticorrosion coating composition, thus completing the present invention.

That is, the present invention provides a liquid composition 100 in which a plurality of acrylic resin copolymers are homogeneously dispersed in a solvent.
Glass powder or hard resin powder 100 to 4 with respect to parts by weight
The present invention provides a coating composition for anticorrosion, which comprises 00 parts by weight and 5 to 20 parts by weight of titanium oxide powder.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a liquid composition in which a plurality of acrylic resin copolymers are homogeneously dispersed in a solvent means a specific high molecular weight polymer, which is also called a modified polyester resin, dissolved in a solvent. Solution polymerization of an isobutyl methacrylate monomer and a butyl acrylate monomer in an organic solvent such as isopropyl alcohol, kerosene or acetone, and then living polymerization of a monomer having a carboxyl group at the end using a catalyst such as boron. The liquid polymer thus obtained is exemplified. Further, the liquid composition of the present invention may be one obtained by further dissolving or dispersing the liquid polymer obtained by the above-mentioned living polymerization in an organic solvent such as isopropyl alcohol, kerosene or acetone.

The acrylic resin is isobutyl methacrylate.
In the case of a copolymer of butyl acrylate and butyl acrylate, the composition ratio of isobutyl methacrylate and butyl acrylate in the copolymer is usually 1: 1 to 3: 1 by weight.
It is preferably 1.5: 1 to 2: 1.

The step of solution polymerizing the isobutyl methacrylate monomer and the butyl acrylate monomer usually comprises a plurality of steps. The first step is a polymerization step in which, in a solvent, for example, a reaction initiator having a silyl group is used to form a main chain of a monomer blended at a predetermined ratio. In this polymerization, a reaction initiator is bonded to a monomer and grows into a polymer to form a main chain. Then, this silyl group moves to the opposite end of the monomer, bonds with another monomer, and grows again into a polymer. This repetition continues until the monomer is consumed, and a polymer having a complicated structure can be synthesized.

Next, as described above, when a catalyst such as a compound containing iodine is used and a monomer having a carboxyl group is added to the polymer, which is considered to have terminated the growth of the polymer from the monomer, and living polymerization is performed, the polymer is revived again to grow. start. A so-called rubber ball-shaped acrylic resin having a three-dimensional network structure obtained by such a polymerization method is
The molecule in the polymer chain is partially esterified, and the structure is such that the hydroxyl group is killed and the carboxyl group is partially left.

The reason why such a liquid composition, that is, a liquid acrylic resin is selected is that the resin has a very good dispersion performance due to the addition of various fine powders as compared with ABS resin, polyethylene resin and the like. Moreover, it is excellent in flexibility and has excellent adhesiveness not only to the surface of concrete or cement mortar but also to the metal surface, so that a small amount of fine powder can exert a high anticorrosion effect. The reason for this is, as described above, that the resin according to the present invention has a ester group, but it is a special resin modified with an acrylic resin that does not have an OH group, and since it has a particularly large number of COOH groups, it can be used, for example, in concrete or cement. Regarding the adhesiveness with the surface of the mortar, it is because it reacts with Ca present in the coated substrate to form a strong compound having a good bite. In addition, this resin, even when the target to be applied is a metal surface,
This is because, as a binder for applying the fine powder to the surface of iron, the affinity between the COOH group and iron is increased in the same manner as described above, and the present composition exhibits a remarkable anticorrosion effect as described in detail below.

The reason why isopropyl alcohol, kerosene, and acetone are selected as the solvent is that they are soluble in the above-mentioned solvents which are widely used in solution polymerization of the resin (copolymer) used in the present invention. It is nothing but the result of synthesis according to the degree of polymerization of. The degree of polymerization of the acrylic resin is usually 200,000 to 600,000, preferably 3
It is 00000-500,000. As a liquid composition in which an acrylic resin having such a degree of polymerization is uniformly dispersed, there is a trade name “Permshield” by Hertz Chemical Co., Ltd.

In the present invention, glass powder or hard resin powder is used as the filler to be mixed with the liquid composition. Here, "or" means one or two kinds selected from glass powder and hard resin powder.

In the present invention, the quality of the glass powder is not particularly limited, and ordinary glass powder is used. Examples of the glass powder include powder of glass cullet, which is industrial waste, powder of new E glass, borosilicate glass, and the like. Of these, glass cullet powder is preferable because it enables recycling of industrial waste.

The average particle size of the glass powder is usually 5
˜150 μm, preferably 50 to 130 μm, more preferably 100 to 130 μm. Here, the average particle diameter is a value obtained by an electron microscope. The above glass powders can be used alone or in combination of two or more.

As the hard resin powder used in the present invention, for example, recycled PET powder obtained by crushing PET bottles which are industrial wastes, recycled hard polycarbonate powder obtained by crushing hard polycarbonate product, or hard polypropylene product is crushed. Examples of the powder include recycled hard polypropylene powder, new PET, hard polycarbonate, and hard polypropylene powder. Of these, PET
A powder obtained by crushing a bottle is preferable because it enables recycling of industrial waste.

Regarding the particle size of the hard resin powder, the average particle size is usually 130 to 300 μm, preferably 130 to 150 μm. Here, the average particle diameter is a value obtained by an electron microscope. The hard resin powder may be used alone or in combination of two or more.

In the present invention, it is preferable to use the glass powder and the hard resin powder in combination because the corrosion resistance is further improved. When these are used in combination, the mixing ratio of the glass powder and the hard resin powder is a weight ratio, preferably 10 to 50: 9.
It is 0 to 50, and more preferably 10 to 30:90 to 70. When the mixing ratio of the glass powder and the hard resin powder is within the range, a relatively small amount of the glass powder is formed in a gap formed by combining a relatively large amount of the hard resin powder with an acrylic resin having excellent affinity with each other. Is preferable because it is easy to disperse so as to be wrapped.

In the present invention, titanium oxide powder is further used as a filler mixed with the above liquid composition. The crystalline state of the titanium oxide powder used in the present invention is not particularly limited, and examples thereof include rutile type, anatase type, and brookite type. Among these, anatase type titanium oxide powder is preferable because it has a large photocatalytic action and a high oxidative decomposition ability of an organic chemical substance that is a causative substance of sick house syndrome.

The anticorrosion coating composition according to the present invention contains the above liquid composition, glass powder or hard resin powder, and titanium oxide powder. The compounding ratio of the glass powder or the hard resin powder in the anticorrosion coating composition is 100
It is usually 100 to 400 parts by weight, preferably 120 to 150 parts by weight, based on parts by weight. When the mixing ratio of the glass powder or the hard resin powder is within the range, the coating film has excellent corrosion resistance, the color tone of the glass powder or the like does not appear in the coating film, and the surface hardness of the coating film is 6H or more in pencil hardness. Therefore, it is preferable.

The proportion of titanium oxide powder in the anticorrosion coating composition is usually 5 to 100 parts by weight of the liquid composition.
20 parts by weight, preferably 7 to 15 parts by weight. It is preferable that the content of these components in the anticorrosion coating composition is within the range because the color tone of the coating film can be masked in white and flexibility is increased, and the photocatalytic action is sufficiently exhibited.

The anticorrosion coating composition according to the present invention can be obtained, for example, by adding glass powder or hard resin powder and titanium oxide powder to a liquid composition and kneading the mixture with a mixer or the like.

The anticorrosion coating composition according to the present invention can be used, for example, as an anticorrosion coating composition for iron products such as steel plates and steel pipes, particularly steel pipes. When a corrosion-resistant coating film is formed on an iron product using the corrosion-resistant coating composition according to the present invention, the thickness of the coating film is not particularly limited because it depends on the use of the iron product, but the thickness at the time of application is usually 200. ~ 500
The thickness can be made as thin as μm, preferably 300 to 400 μm. The abrasion resistance of the coating film is 3 in a taper type abrasion tester when the thickness of the formed coating film is 300 μm.
It will be over 50 times.

[0025]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but these are merely examples and do not limit the present invention.

Example 1 A copolymer of isobutyl methacrylate and butyl acrylate by solution polymerization (the composition ratio of isobutyl methacrylate and butyl acrylate is 2: 1 by weight, and the degree of polymerization is 300,000). However, 200 g of a liquid composition having a resin solid content of 30% by weight in kerosene was obtained. To the liquid composition was added 46 g of powder of glass cullet having an average particle diameter of 100 μm, 184 g of regenerated powder of PET bottle having an average particle diameter of 100 μm, and 250 g of mixed powder of 20 g of rutile titanium oxide powder, and kneading for 10 minutes with a mixer. Thus, 450 g of a coating composition for anticorrosion was obtained.

The anticorrosion coating composition was applied to 150 mm × 150
It is applied on the surface of an iron plate of mm x 1.2 mm, and the thickness is 300 μm.
The test material which formed the coating film of was obtained. The coating film of the test material was white, and the color of the glass cullet powder and the regenerated powder of the PET bottle did not appear in the coating film. JIS using the test material
According to K5400, pencil hardness, etc., and JIS H850
Tests were carried out according to No. 3 for wear resistance. The results are shown in Table 1.
Shown in.

[0028]

[Table 1]

[0029]

EFFECTS OF THE INVENTION The anticorrosion coating composition according to the present invention is a generally used anticorrosion coating even when a corrosive coating is formed using a filler such as glass cullet powder or discarded PET bottle powder. Corrosion resistance is equivalent to that of the composition, and the finish of the coating film surface can be colored in an arbitrary color without cracks or the color tone of the filler appearing on the surface of the coating film. Therefore, it is extremely effective as a method for disposing of glass cullet and discarded PET bottles.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Arai             2-19-60-601 Mihara, Asaka City, Saitama Prefecture (72) Inventor Tomoaki Fujishima             6-20-12 Hatanodai, Shinagawa-ku, Tokyo F-term (reference) 4J038 CG141 CH031 DD062 GA06                       HA216 HA486 KA08 NA01                       NA03 PC04

Claims (6)

[Claims] 1. 100 to 400 parts by weight of glass powder or hard resin powder and 5 to 20 parts by weight of titanium oxide powder to 100 parts by weight of a liquid composition in which a plurality of acrylic resin copolymers are homogeneously dispersed in a solvent. A coating composition for corrosion protection, which comprises a part. 2. The anticorrosion coating composition according to claim 1, wherein the acrylic resin copolymer is a copolymer of isobutyl methacrylate and butyl acrylate. 3. The composition ratio of isobutyl methacrylate and butyl acrylate in the copolymer is 1: by weight.
It is 1-3: 1, The anticorrosion coating composition of Claim 2 characterized by the above-mentioned. 4. The solvent is isopropyl alcohol,
It is kerosene or acetone, It is characterized by the above-mentioned.
4. The coating composition for corrosion prevention according to any one of 3 to 3. 5. The anticorrosion coating composition according to any one of claims 1 to 4, wherein the glass powder is glass cullet powder. 6. The anticorrosion coating composition according to any one of claims 1 to 5, wherein the hard resin powder is a regenerated PET powder.