JP4150104B2 - Anticorrosion paint composition - Google Patents

Description

【００２５】
なお、防食塗料組成物の性能試験の方法は以下の通りである。
（１）耐衝撃性試験（デュポン式）
各試料を、脱脂した磨き軟鋼板（２００×１００×０.６ｍｍ）にアプリケーターににより約２５０μｍの乾燥膜厚になるように塗装し、２０℃×６５％ＲＨの雰囲気下で７日間乾燥して各試験塗板を作成した。
上記塗板について、２０℃の雰囲気中でＪＩＳ Ｋ５４００―１９９０に規定するデュポン式衝撃試験を行った。
（２）耐冷熱繰返し性試験
脱脂した磨き軟鋼板に、シリケートジンクプライマーを約２５μｍの乾燥膜厚になるように塗装し、１日乾燥した。この上に、各試料をそれぞれアプリケーターにより約２５０μｍの乾燥膜厚になるように塗装し、２０℃×６５％ＲＨの雰囲気下で７日間乾燥して各試験片を得た。
これらの試験片について、ＪＩＳ Ｋ５４００―１９９０に従い耐冷熱繰返し性試験を行った。
（３）耐海水性試験
上記（２）耐冷熱繰返し性試験において作成したと同様の試験片を、５０℃の海水中に６ヶ月浸漬し、その後の塗面状態を目視で評価した。評価の基準は以下の通りである。
○：異常なし
△：フクレがわずかに発生
×：フクレが著しく発生
【００２６】
【発明の効果】
本発明の防食塗料組成物は、インデン類含有率を特定したフェノール性水酸基含有石油樹脂を用いているので、エポキシ樹脂や硬化剤特にアミン系硬化剤と石油樹脂との相溶性が良好であり、衛生上問題がなく、防食性、耐水性、付着性などに優れ、しかも明色の塗膜を形成することができ、船舶や構造物の防食塗料として非常に有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anticorrosive coating composition that is an alternative coating for a tar-based epoxy coating, and is particularly useful for coating in a portion that comes into contact with seawater, for example, a ship's ballast tank.
[0002]
[Prior art]
Conventionally, tar-based epoxy paints are used as anticorrosive paints for ships, steel structures and the like. This paint is excellent in corrosion resistance, water resistance, chemical resistance, etc., but since it contains tar, not only is it concerned about hygiene problems, but it is black and difficult to maintain and seals. There was a problem that the work was dangerous because it was dark in the place.
[0003]
[Prior art issues]
In recent years, non-tar epoxy paints using petroleum-based resins instead of tar have also been developed. For example, Japanese Patent Publication No. 59-52656 and Japanese Patent Laid-Open No. 9-263713 have been proposed. That is, the resin described in JP-B-59-52656 contains a hydroxyl group, and in the examples, a fraction containing an unsaturated component obtained from cracking of naphtha is polymerized in the presence of phenol to have a softening point of 93 ° C. Has obtained a resin. JP-A-9-263713 discloses an epoxy resin system using a divinyltoluene-indene copolymer (softening point 100 ° C.) having a hydroxyl group content of 1 to 1.1 mol in one molecule in Examples. An anticorrosion paint is disclosed. However, the epoxy paint described in the above publication has a problem in compatibility between the epoxy resin, a curing agent, particularly a cured resin composed of an amine curing agent, and a petroleum-based resin, and particularly requires high corrosion resistance and water resistance. It is not sufficient to apply the coating directly in contact with seawater, for example, in a ship's ballast tank.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventor used a resin made from an aromatic fraction with a specified indenes content, and a resin with a relatively reduced content of phenolic hydroxyl groups. By using it, it has excellent compatibility with epoxy resins and curing agents, especially amine-based curing agents, and as a result, there are no sanitary problems, excellent corrosion resistance, water resistance, adhesion, etc., and a light-colored coating film It has been found that an anticorrosive coating composition that can be formed is obtained, and the present invention has been achieved.
[0005]
That is, the first of the present invention is mainly in the boiling range of 140 to 220 ° C. among the epoxy resin (A), the curing agent, preferably the amine-based curing agent (B), and the cracked oil obtained by pyrolysis of petroleum. A phenolic hydroxyl group obtained by polymerizing a cracked oil fraction obtained by distillation from a fraction containing a certain component with a Friedel-Crafts catalyst in the presence of phenols in the presence of phenols. It consists of aromatic petroleum resin (C) containing 0.1 or more and less than 1.0, and containing 1 to 500 parts by weight of aromatic petroleum resin (C) with respect to 100 parts by weight of epoxy resin. The present invention relates to a characteristic anticorrosion coating composition.
2nd of this invention is related with the anticorrosion coating composition whose conjugated diene content rate of a cracked oil fraction is 5 weight% or less in 1st of this invention.
[0006]
Hereinafter, the present invention will be described in detail.
The epoxy resin (A) used in the present invention has at least two epoxy groups in one molecule, and those having an epoxy equivalent of 150 to 600 are suitable, preferably 180 to 500. Examples of such epoxy resins include conventional bisphenol type epoxy resins, aliphatic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, cresol type epoxy resins, dimer acid modified epoxy resins, and the like. A well-known thing is mentioned, These can be used only by 1 type or in mixture of 2 or more types.
[0007]
A conventionally well-known thing is used for the hardening | curing agent (B) used by this invention as a hardening | curing agent of an epoxy resin. Examples include various aliphatic or aromatic amines, polyamide resins, acid anhydrides, phenol resins, polyisocyanates and the like. These may be used alone or in combination of two or more.
Particularly preferred are amine-based curing agents, such as aliphatic polyamines such as metaxylenediamine, isophoronediamine, diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, alicyclic polyamines, aromatic polyamines, and epoxies of these polyamines. Examples thereof include resin adducts, polyamidoamines, and polyamide resins. These may be used alone or in combination of two or more.
[0008]
The mixing ratio of the epoxy resin (A) and the curing agent (B) can be appropriately selected depending on the types of both components. Generally, it is selected from the range of 1 to 200 parts by weight of the curing agent per 100 parts by weight of the epoxy resin. When a preferred amine curing agent is used as the curing agent (B), the equivalent ratio of active hydrogen equivalent in (B) / epoxy equivalent in (A) is usually in the range of 0.5 to 1.0. It is appropriate to select as follows.
[0009]
The aromatic petroleum resin (C) used in the present invention is a petroleum resin solid at room temperature containing a phenolic hydroxyl group and having a softening point of 50 to 150 ° C, preferably 80 to 110 ° C. use.
[0010]
As the above-mentioned petroleum resin, among the cracked oil by-produced when pyrolyzing hydrocarbons such as naphtha and butane in order to produce ethylene, propylene and the like, components having a boiling range of 140 to 220 ° C are mainly used. The fraction containing is used as a raw material. Such fractions include styrene, α- or β-methylstyrene, vinyltoluene, indene, methylindene, unsaturated components such as dicyclopentadiene, dimethylcyclopentadiene, and ethylbenzene, trimethylbenzene, indane, methyl. Contains saturated components such as indane and naphthalene. Furthermore, conjugated dienes such as cyclopentadiene and methylcyclopentadiene produced by thermal decomposition of dicyclopentadiene, dimethylcyclopentadiene and the like during distillation operation are also included.
[0011]
In the present invention, a fraction obtained by distillation of the cracked oil and having an indene content of 60 to 90% by weight is used as a raw material. If a fraction outside this range is used, the performance as an anticorrosion coating composition is lowered as a result, which is not preferable. Here, the indens content (% by weight) is defined by (total amount of alkylindene such as indene and methylindene) / (total unsaturated component content in cracked oil fraction) × 100.
Preferably, a fraction having a conjugated diene content such as cyclopentadiene or methylcyclopentadiene of 5% by weight or less is used. By setting the content of conjugated dienes to 5% by weight or less, the performance as an anticorrosion paint can be further improved. Here, the conjugated diene content (% by weight) is defined as (total amount of conjugated diene) / (total unsaturated component content in cracked oil fraction) × 100.
The above components can be easily analyzed by a known gas chromatographic method.
The cracked oil fraction having the above composition can be easily obtained by appropriately treating the cracked oil by-produced by thermal cracking with a combination of known distillation methods.
[0012]
In the raw material resin of the present invention, 1.0 to 10.0 parts by weight of phenols coexist in 100 parts by weight of the cracked oil fraction, and 0.01 to 3% by weight of Friedel based on the cracked oil fraction. -It can manufacture by polymerizing in the range of 10-100 degreeC using a crafts catalyst.
Examples of phenols include, in addition to phenol, alkyl group-substituted phenols such as cresol, xylenol, tert-butylphenol, and nonylphenol. These can also be used as a mixture. Preferably it is phenol. Phenols can be present in the reaction system as a component of the Friedel-Crafts catalyst described later, but usually a predetermined amount of phenol is often supplied to the reaction system separately from the catalyst.
[0013]
As the Friedel-Crafts catalyst, a metal halide, preferably boron trifluoride, or a complex thereof with an oxygen-containing compound such as phenol, ethyl ether, butyl ether, butyl alcohol, or methyl alcohol is used.
The polymerization time can be selected from the range of 0.5 to 10 hours in the case of a batch system.
A resin having a predetermined softening point is obtained by charging a predetermined amount of the cracked oil fraction, phenols, Friedel-Crafts catalyst and the like and polymerizing by a known method. After polymerization, the catalyst is appropriately deactivated using alkali or the like, and then the unreacted oil or low polymer is appropriately separated and removed by distillation or the like to obtain the desired resin.
[0014]
The petroleum resin (C) used in the coating composition of the present invention contains 0.1 or more and less than 1.0 phenolic hydroxyl groups in one molecule of petroleum resin. The number is preferably 0.5 to 0.9. In the polymerization, a resin in which the amount of phenolic hydroxyl group is within the above range can be obtained by appropriately adjusting the amount of each raw material and the polymerization conditions.
When 1.0 or more phenolic hydroxyl groups are present in one molecule of the petroleum resin (C) used in the present invention, it is not preferable as a resin for anticorrosion coating. On the other hand, if it is less than 0.1, the compatibility with the epoxy resin is lowered, which is also not preferable. The amount of phenolic hydroxyl group present in the obtained resin can be measured, for example, by the method described in IEC Anal. Ed. 17 (1945) p. 394.
[0015]
The softening point of the resin (C) is in the range of 50 to 150 ° C., preferably 80 to 110 ° C. as described above. If the softening point is less than 50 ° C, the water resistance of the anticorrosion coating is low, and the resin component may bleed on the surface of the coating and stickiness may remain. On the other hand, if it exceeds 150 ° C, the viscosity of the coating will increase and workability will be increased. It is not desirable because it lowers and physical properties of the coating film deteriorate. In addition, the molecular weight of resin (C) used for this invention is the range of 500-3000 as a number average molecular weight.
[0016]
In order to obtain the composition of the present invention, 1 to 500 parts by weight, preferably 10 to 300 parts by weight of the petroleum resin (C) containing the phenolic hydroxyl group is blended with 100 parts by weight of the epoxy resin (A). If the blending amount is less than 1 part by weight, sufficient water resistance cannot be obtained for the obtained composition. On the other hand, if it exceeds 500 parts by weight, the coating film becomes brittle and good physical properties cannot be obtained.
[0017]
In order to impart further flexibility to the anticorrosive coating composition of the present invention, other liquid modifiers such as xylene resin, toluene resin; reactive diluents such as epoxy compounds such as butyl glycidyl ether, and the like. Further, it may be added in a range of 50 parts by weight or less with respect to 100 parts by weight of the cured resin solid content. Of these, aromatics are preferably used from the viewpoint of maintaining water resistance.
[0018]
If necessary, the composition of the present invention may further include pigments such as extender pigments, rust preventive pigments, and colored pigments; reactive diluents; organic solvents, anti-settling agents, anti-sagging agents, wetting agents, and reaction accelerators. Ordinary paint additives such as an adhesion-imparting agent and a dehydrating agent may be appropriately blended.
[0019]
The composition of the present invention is a two-component paint comprising an epoxy resin-containing main agent and a curing agent, preferably an amine curing agent, and is usually applied onto a primary anticorrosive coating such as a zinc primer. That is, first, shot blasting is applied to the steel plate to remove the mill scale, and an inorganic zinc shop primer such as ethyl silicate is applied, and then the coating composition of the present invention is applied. The primer is not limited to zinc silicate, and various primers can be used. Further, even a steel plate without a primer can be coated, and a sufficient anticorrosion effect can be obtained.
As a coating method, conventionally known methods such as air spray, airless spray, brush coating, and roller can be adopted, and the coating composition can be applied so as to have a dry film thickness of 150 to 500 μm.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” and “%” indicate “parts by weight” and “% by weight”, respectively.
【Example】
<Production example>
By fractionating a fraction having a boiling range of 140 to 220 ° C. from cracked oil obtained by thermal decomposition of naphtha, the total unsaturated component amount is 51%, the indene content is 70%, and the conjugated diene content is 0. A cracked oil fraction adjusted to 5% was obtained.
Next, 5 g of phenol was added to 100 g of the cracked oil fraction, 0.5 g of boron trifluoride-phenol complex was added, polymerized at 30 ° C. for 3 hours, the catalyst was removed with an aqueous caustic soda solution, and then washed with water. Thereafter, unreacted oil and low polymer were removed by distillation to obtain 56 g of petroleum resin (A).
The resulting resin had a softening point of 103 ° C., and as a result of analysis, it was confirmed that the resin had 0.8 phenolic hydroxyl groups per molecule.
[0021]
<Comparative production example>
In the same manner as in the above production example, a cracked oil fraction having an indene content of 20% and a conjugated diene content of 6% was obtained.
This was polymerized in the same manner to obtain a petroleum resin (B) having a softening point of 85 ° C. and 0.8 phenolic hydroxyl groups per molecule.
[0022]
<Example 1>
In a container, 100 parts of epoxy resin, 30 parts of titanium white, 100 parts of talc, 100 parts of petroleum resin (A) obtained in the production example, 20 parts of hydrocarbon plasticizer, 5 parts of sagging agent and xylene, MIBK and cyclohexane An equivalent amount of 150 parts of a mixed solvent was added, mixed and stirred with a stirrer, and dispersed to obtain a main agent. To this was added 80 parts of polyamide resin (in terms of solid content) as a curing agent, mixed and stirred to obtain an anticorrosive coating composition. The composition and results are shown in Table 1.
[0023]
<Example 2, comparative example>
Compositions were similarly produced with the formulations shown in Table 1. In the comparative example, the petroleum resin (B) of the comparative production example was used. The results are shown in Table 1.
[0024]
[Table 1]

[0025]
In addition, the method of the performance test of anticorrosion coating composition is as follows.
(1) Impact resistance test (DuPont type)
Each sample was coated on a degreased polished mild steel plate (200 × 100 × 0.6 mm) with an applicator to a dry film thickness of about 250 μm and dried for 7 days in an atmosphere of 20 ° C. × 65% RH. Each test coating was prepared.
The coated plate was subjected to a DuPont impact test as defined in JIS K5400-1990 in an atmosphere of 20 ° C.
(2) Cold-heat repeatability test A silicate zinc primer was applied to a degreased polished mild steel sheet so as to have a dry film thickness of about 25 μm and dried for one day. On top of this, each sample was coated with an applicator so as to have a dry film thickness of about 250 μm, and dried for 7 days in an atmosphere of 20 ° C. × 65% RH to obtain each test piece.
These test pieces were subjected to a cold-heat repeatability test according to JIS K5400-1990.
(3) Seawater resistance test A test piece similar to that prepared in the above (2) cold-heat repeatability test was immersed in seawater at 50 ° C for 6 months, and the subsequent coating surface state was visually evaluated. The criteria for evaluation are as follows.
○: No abnormality △: Slight swelling occurs ×: Severe swelling occurs [0026]
【The invention's effect】
Since the anticorrosion coating composition of the present invention uses a phenolic hydroxyl group-containing petroleum resin that specifies the indenes content, the compatibility between the epoxy resin and the curing agent, in particular, the amine curing agent and the petroleum resin is good, There is no problem in terms of hygiene, excellent corrosion resistance, water resistance, adhesion, etc., and can form a light-colored coating film, which is very useful as an anticorrosion paint for ships and structures.

Claims (1)

Indens content obtained by distillation from a fraction containing mainly components in the boiling range of 140 to 220 ° C. among the epoxy resin (A) , the amine-based curing agent (B), and cracked oil obtained by thermal decomposition of petroleum. Aroma containing 0.1 to less than 1.0 phenolic hydroxyl group per molecule, obtained by polymerizing 60 to 90% by weight of cracked oil fraction with Friedel-Crafts catalyst in the presence of phenols An anticorrosion coating composition comprising an aromatic petroleum resin (C) and containing 1 to 500 parts by weight of the aromatic petroleum resin (C) with respect to 100 parts by weight of an epoxy resin, containing a conjugated diene of the cracked oil fraction An anticorrosive coating composition having a rate of 5% by weight or less .