WO1999058618A1 - Coating composition for corrosion proofing - Google Patents

Abstract

An epoxy coating composition for corrosion proofing which comprises an epoxy resin (A), a curing agent (B), preferably an amine curing agent, and an aromatic petroleum resin (C) which is prepared by polymerizing a cracked oil fraction having a content for indenes of 60 to 90 wt.% in the presence of phenols and has phenolic hydroxyl groups less than 1.0 per one molecule thereof, wherein the content of the petroleum resin is 1 to 500 parts by weight relative to 100 parts by weight of the epoxy resin. The epoxy coating composition contains no tar and hence is usable for application to a part contacting with sea water.

Description

 Description Anticorrosion paint Composition Technical field

 TECHNICAL FIELD The present invention relates to an anticorrosion paint composition which is an alternative paint to a tar-based epoxy paint, and which is particularly useful for painting in a portion in contact with seawater, for example, in a ballast tank of a ship. Technology background

 Conventionally, tar epoxy coatings have been used as anticorrosion coatings for ships, steel structures and the like. Although this paint is excellent in corrosion resistance, water resistance, chemical resistance, etc., it is not only a concern for hygiene due to the inclusion of silver, but it is difficult to maintain due to its black color. However, there was a problem that the work was dangerous because it became dark in a closed place.

In recent years, non-tar epoxy paints using petroleum-based resins instead of tar have been developed. For example, a proposal has been made in Japanese Patent Publication No. Sho 59-52666 / Japanese Patent Application Laid-Open No. Hei 9-263713. That is, the resin described in Japanese Patent Publication No. 59-52666 contains a hydroxyl group, and in the examples, a fraction containing an unsaturated component obtained from cracking of naphtha was polymerized in the presence of phenol. The resin has a softening point of 93 ° C. Japanese Patent Application Laid-Open No. 9-263713 discloses a divinyltoluene-indene copolymer having a hydroxyl content in one molecule of 1 to: L. 1 mol (softening point 100 °) in Examples. An epoxy resin-based anticorrosive paint using C) is disclosed. However, the epoxy coatings described in the above publications have a problem in compatibility between the epoxy resin, the curing agent, particularly the cured resin composed of the amine curing agent, and the petroleum-based resin. It is not sufficient for painting areas that come into direct contact with seawater, for example, in ballast tanks on ships. Disclosure of the invention

 The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have used a resin starting from an aromatic fraction having a specified indene content and relatively reduced the content of phenolic hydroxyl groups. By using resin, it has excellent compatibility with epoxy resins and hardeners, especially amine-based hardeners. As a result, there is no problem in hygiene, corrosion resistance, water resistance, adhesion, etc. The present inventors have found that an anticorrosive coating composition capable of forming a film can be obtained, and have reached the present invention.

 That is, the first aspect of the present invention is that the epoxy resin (A), the curing agent, preferably the amine-based curing agent (B), and the cracked oil obtained by thermal cracking of petroleums are mainly 140 to 220 ° C. It is obtained by polymerizing a cracked oil fraction with an indene content of 60 to 90% by weight obtained by distillation from a fraction containing components in the boiling range of C with a Friedel-Crafts catalyst in the presence of phenols. An aromatic petroleum resin (C) containing at least 0.1 and less than 1.0 phenolic hydroxyl groups per molecule, wherein the aromatic petroleum resin (C) is added to 100 parts by weight of the epoxy resin. 1 to 500 parts by weight.

 The second aspect of the present invention relates to the anticorrosion paint composition according to the first aspect of the present invention, wherein the conjugated gen content of the cracked oil fraction is 5% by weight or less.

 Hereinafter, the present invention will be described in detail.

 The epoxy resin (A) used in the present invention has at least two or more epoxy groups in one molecule, and suitably has an epoxy equivalent of 150 to 600, preferably 180. 0 to 500. Examples of such epoxy resins include bisphenol epoxy resins, aliphatic epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, phenol nopolak epoxy resins, cresol epoxy resins, and dimers. Conventionally known ones such as an acid-modified epoxy resin may be mentioned, and these may be used alone or in combination of two or more.

As the curing agent (B) used in the present invention, a conventionally known curing agent for an epoxy resin is used. For example, various aliphatic or aromatic amines, polyamide resin, acid anhydrides, phenolic resins, polyisocyanates and the like are exemplified. These are 1 They can be used alone or as a mixture of two or more.

 Particularly preferred are amine-based curing agents, for example, aliphatic polyamines such as metaxylenediamine, holondiamine, diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, alicyclic polyamines, aromatic polyamines, and these polyamines. Epoxy resin adducts, polyamidoamines, and polyamide resins. These can be used alone or in combination of two or more.

 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 hardener per 100 parts by weight of epoxy resin. When a preferred amine-based curing agent is used as the curing agent (B), the active hydrogen equivalent in (B) and the equivalent ratio of epoxy equivalent in (A) are usually 0.5 to 1.0. It is appropriate to select a value within the range. The aromatic petroleum resin (C) used in the present invention is a petroleum resin containing a phenolic hydroxyl group, which is solid at room temperature and has a softening point of 50 to 150 ° C., preferably Use the one of 80 to 110 ° C.

 Among the above petroleum resins, the cracking oil mainly produced by cracking of hydrocarbons, such as naphtha and butane, by-produced to produce ethylene, propylene, etc.

ンも含まれている。 本発明においては、 前記分解油の蒸留により得られる留分であって、 インデン 類含有率が 6 0〜9 0重量％の留分を原料とする。 この範囲を外れる留分を用い ると、 結果として防食塗料組成物としての性能が低下するので好ましくない。 こ こで、 インデン類含有率 （重量％) は、 （インデンおよびメチルインデン等のァ ルキルインデンの合計量 Z分解油留分中の全不飽和成分含有量） X 1 0 0で定 義される。 A fraction containing components in the range of 140 to 220 ° C is used as a raw material. Such fractions include styrene, α- or i3-methylstyrene, vinyltoluene, indene, methylindene, unsaturated components such as dicyclopentadiene, dimethylcyclopentene, and ethylethyl, trimethylbenzene, Includes saturated components such as indane, methyl indane, and naphthalene. In addition, the system produced by the dicyclobe

Is also included. 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 anticorrosive coating composition is consequently deteriorated, which is not preferred. Here, the indene content (% by weight) is defined as (total amount of alkyl indene such as indene and methyl indene Z content of all unsaturated components in cracked oil fraction) X 100 Is defined.

 Preferably, a fraction having a conjugated diene content of 5% by weight or less, such as cyclopentadiene or methylcyclopentadiene, is used. By setting the content of the conjugated gen to 5% by weight or less, the performance as an anticorrosion paint can be further improved. Here, the content (% by weight) of the conjugated gens is defined as (total amount of conjugated gens Z total content of unsaturated components in the cracked oil fraction) X 100.

 The above components can be easily analyzed by a known gas chromatography method.

 The cracked oil fraction having the above composition can be easily obtained by appropriately treating cracked oil produced as a by-product of thermal cracking with a known distillation method.

 The raw material resin of the present invention comprises 1.0 to 10.0 parts by weight of phenols in 100 parts by weight of the cracked oil fraction and 0.01 to 3 parts by weight based on the cracked oil fraction. % Of Freedell-Crafts catalyst and polymerized in the range of 10 to 10 ° C.

 Examples of the phenols include, in addition to phenols, alkyl-substituted phenols such as cresol, xylenol, tert-butylphenol, and nonylphenol. These can be used in combination. Preferred is phenol. Phenols can be present in the reaction system as a component of the Friedel Crafts catalyst described below, but usually a predetermined amount of phenol is supplied to the reaction system separately from the catalyst. Many.

 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 can be 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 the polymerization, the catalyst is appropriately deactivated using an 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. The petroleum resin (C) used in the coating composition of the present invention contains at least 0.1 and less than 1.0 phenolic hydroxyl groups in one molecule of the petroleum resin. Preferably, it is 0.5 to 0.9. In addition, at the time of polymerization, a resin having an amount of phenolic hydroxyl groups within the above range can be obtained by appropriately adjusting the amount of each raw material, the polymerization conditions, and the like.

 If one 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 paint. On the other hand, if it is less than 0.1, the compatibility with the epoxy resin is lowered, which is not preferable. The amount of the phenolic hydroxyl group present in the obtained resin can be measured, for example, by the method described in IE. III. C. Anal. Ed. (1945) p. 394.

 The softening point of the resin (C) is in the range of 50 to 150 ° (preferably, 80 to 110 ° C as described above. If the softening point is less than 50 ° C, The water resistance of the anti-corrosion coating film is low, and the resin component may be bled on the surface of the coating film and the tackiness may remain.On the other hand, when the temperature exceeds 150 ° C, the viscosity of the coating material increases and the workability decreases. The molecular weight of the resin (C) used in the present invention is in the range of 500 to 300 as a number average molecular weight.

 In order to obtain the composition of the present invention, the petroleum resin (C) having a phenolic hydroxyl group is added in an amount of 1 to 500 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the epoxy resin (A). 300 parts by weight are blended. If the amount is less than 1 part by weight, sufficient water resistance cannot be obtained in the obtained composition, while if it exceeds 500 parts by weight, the coating film becomes brittle and good physical properties cannot be obtained. Not preferred.

 The anticorrosive coating composition of the present invention may further contain other liquid modifiers such as xylene resin and toluene resin, and reactive diluents such as epoxy compounds such as butyldaricidyl ether to impart flexibility. May be added in a range of 50 parts by weight or less based on 100 parts by weight of the solid content of the cured resin. Of these, aromatic ones are preferably used from the viewpoint of maintaining water resistance.

The composition of the present invention may further include, if necessary, an extender pigment> pigments such as an anti-pigment pigment and a color pigment; a reactive diluent; an organic solvent, an anti-settling agent, a sunscreen agent, a wetting agent, and a reaction promoting agent. Ordinary paint additives such as a promoter, an adhesion-imparting agent, and a dehydrating agent may be appropriately compounded. Further, the composition of the present invention is a two-pack type paint comprising a main agent containing an epoxy resin and a curing agent, preferably an amine-based curing agent, and is usually applied on a primary anti-reflective coating film such as a zinc primer. That is, a steel plate is first subjected to shot blasting to remove 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 the like, and various primers can be used. In addition, even a steel plate without a primer can be coated, and a sufficient anticorrosion effect can be obtained.

 As a coating method, a conventionally known method such as air spraying, airless spraying, brush coating, and mouth washing can be adopted.The above coating composition is dried to have a dry film thickness of 150 to 500 m. Can be applied. BEST MODE FOR CARRYING OUT 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.

<Production example>

 By fractionating the fraction having a boiling point of 140 to 220 ° C from the cracked oil obtained by the thermal cracking of naphtha, the total unsaturated component content is 51%, the indene content is 70%, A cracked oil fraction adjusted to 0.5% of synergist content 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, and the mixture was polymerized at 30 ° C. for 3 hours. After removing the catalyst with an aqueous solution and then washing with water, unreacted oil and low polymer were removed by distillation to obtain 56 g of a petroleum resin (A).

 The softening point of the obtained resin was 103 ° C., and as a result of analysis, it was confirmed that the molecule had 0.8 phenolic hydroxyl groups per molecule.

<Comparative production example>

 A cracked oil fraction having an indene content of 20% and a conjugated gen content of 6% was obtained in the same manner as in the above Production Example.

This was polymerized in the same manner to obtain a petroleum resin (B) having a softening point of 85 ° (: 0.8 phenolic hydroxyl groups per molecule). <Example 1>

 In a container, 100 parts of epoxy resin, 300 parts of titanium white, 100 parts of talc, 100 parts of petroleum resin (A) obtained in Production Example, 20 parts of hydrocarbon plasticizer, 5 parts of anti-sagging agent Then, 150 parts by weight of a mixed solvent of xylene, MIBK and cyclohexane were added, and the mixture was dispersed by stirring with a stirrer. To this, 80 parts (in terms of solid content) of a polyamide resin was added as a curing agent, followed by mixing and stirring to obtain an anticorrosion coating composition. Table 1 shows the composition and the results.

<Example 2, comparative example>

Compositions were produced in the same manner with the formulations shown in Table 1. In the comparative example, the petroleum resin (B) of the comparative production example was used. Table 1 shows the results.

Example Comparative example

1 2 1 Epoxy resin ⁽¹⁾ 100 100 100 Titanium white 30 30 30 Charge Talc 100 100 100 pairs Petroleum resin (A) ⁽²⁾ 100 200

Petroleum resin (B) ⁽³⁾ 150 Plasticizer ⁽⁴⁾丄 U 丄 U 10 ri

Part Anti-sagging agent ⁽⁵⁾ D 0 0 Mixed solvent 150 150 1 丄 t ^ A Hardener (solid content conversion) ( ⁶⁾ 80 80 80 Impact resistance:

 Pass pass crack

500 gX30 cm

 Cold heat repetition resistance:

 -20 ° C X 1 hr ^ Pass Pass Crack 60 ° C X lhr 3 times

 Seawater resistant 〇 〇 Δ Note (1) Epoxy equivalent 475; Trade name “Ebon # 001”

 Yuka Shell Epoxy

 (2) Petroleum resin obtained in Production Example (A)

 (3) Petroleum resin obtained in Comparative Production Example (B)

 (4) Hydrocarbon plasticizer; trade name "Hisol S AS LH", manufactured by Nippon Petrochemical Co., Ltd.

 (5) Fatty acid derivative; trade name "ASA T-55-20 BX", manufactured by Ito Oil Co., Ltd.

(6) Polyamide resin curing agent; trade name "Versamide 115", manufactured by Henkel Hakusui Co., Ltd .; provided as a 50% solution of a mixed solvent of equal amounts of xylene, MIBK and cyclohexane. In addition, the method of the performance test of the anticorrosion coating composition is as follows.

 (1) Impact resistance test (DuPont type)

 Each sample was coated on a degreased polished mild steel plate (200 x 100 x 0.6 mm) by an applicator to a dry film thickness of about 250 m, and then dried under an atmosphere of 20 ° C and 65% RH. After drying for 7 days, each test coated plate was prepared.

 The coated plate was subjected to a DuPont impact test specified in JIS K5400-1990 in an atmosphere of 20 ° C.

 (2) Cold heat repetition test

 The degreased polished mild steel sheet was coated with a silica zinc primer to a dry film thickness of about 25 m and dried for one day. On this, each sample was applied to a dry film thickness of about 250 m by means of apriquet overnight and dried for 7 days in an atmosphere of 20 ° C and 65% RH to obtain each test piece.

 These test pieces were subjected to a cold-heat repetition test according to JIS K5400-1990.

 (3) Seawater resistance test

 A test piece similar to that prepared in the above (2) cold / heat repetition resistance test was immersed in 50 seawater for 6 months, and then the state of the coated surface was visually evaluated. The criteria for evaluation are as follows.

 な し No abnormalities

 Δ Slight swelling

 X Significant blistering occurs Industrial availability

 Since the anticorrosion coating composition of the present invention uses a petroleum resin containing a hydroxyl group-containing hydroxyl group having a specific content of an indene, the compatibility between the epoxy resin and the curing agent, particularly the amine-based curing agent, and the oil resin is improved. It is good, has no hygiene problems, is excellent in corrosion resistance, water resistance, adhesion, etc., and can form a light-colored coating film.It is very useful as an anticorrosion paint for ships and structures. is there.

Claims

The scope of the claims 1. Epoxy resin (A), curing agent, preferably amine curing agent (B), and cracked oil obtained by pyrolysis of petroleum, mainly in the boiling point range of 140 to 220 ° C A phenolic compound obtained by polymerizing a cracked oil fraction with a content of 60 to 90% by weight of indene obtained by distillation from a fraction containing a component with a Friedel-Crafff catalyst in the presence of phenols An aromatic petroleum resin (C) having a hydroxyl group content of 0.1 or more and less than 1.0 per molecule, wherein the aromatic petroleum resin (C) is added to 100 parts by weight of the epoxy resin. An anticorrosion coating composition, characterized by containing up to 500 parts by weight.  2. The anticorrosion paint composition according to claim 1, wherein the conjugated gen content of the cracked oil fraction is 5% by weight or less.