JPH1046102A - Metal coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal coating compsn. which can be cured at normal temp., has characteristics, such as mechanical strengths and acid resistance, at least equivalent to those of conventional phenol-epoxy resin coating materials, is excellent in resistances to heat and oil, and can prolong the life of pipeline for petroleum, etc. SOLUTION: This compsn. is a mixture comprising an epoxy resin, an epoxy- modified silicone resin which is a block copolymer of a silicone resin with an epoxy resin, an aminosilane coupling agent, and an org. solvent or is a mixture comprising an epoxy resin, an epoxy-modified silicone resin which is a block copolymer of a silicone resin with an epoxy resin, an aminosilane coupling agent, a resol phenol resin having a number-average mol.wt. of 100-1,500, and an org. solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a heat-resistant resin comprising a mixture of an epoxy resin and an epoxy-modified silicone resin comprising a block copolymer of a silicone resin and an epoxy resin or a resin obtained by mixing a resole-type phenol resin with the mixture. And a metal coating composition having excellent oil resistance.

[0002]

2. Description of the Related Art Relatively inexpensive steel pipes and the like are frequently used for transporting petroleum (including crude oil). However, in order to increase heat resistance and oil resistance, a coating film is applied to the liquid contact surface. It is common practice to apply. In recent years, due to the increase in energy demand, the development of resources such as oil and heavy oil on the seabed and polar regions, and geothermal energy has been activated, and accordingly, measures to further prolong the service life of steel pipes have been strongly desired. ing. Phenol epoxy resin paint, which has been widely used in transportation pipes for crude oil and petroleum, has excellent properties such as mechanical strength and acid resistance, but has the problem of poor heat resistance and oil resistance. The service life of petroleum transport piping was not correspondingly sufficient. Further, the phenol epoxy resin-based paint is hard to cure at room temperature, and needs to be cured by heating at 100 to 200 ° C., and is not a paint suitable for on-site construction.

[0003]

SUMMARY OF THE INVENTION The present invention has characteristics such as mechanical strength and acid resistance that are equal to or higher than those of conventional phenol epoxy resin-based paints, and exhibits extremely excellent heat resistance and oil resistance. An object of the present invention is to provide a metal coating composition which can extend the useful life of a petroleum transportation pipe and the like and can be cured at room temperature.

[0004]

The present invention adopts the following aspects (1) to (4) as means for solving the above problems. (1) an epoxy resin (A), an epoxy modified silicone resin (B) composed of a block copolymer of a silicone resin and an epoxy resin, and an aminosilane coupling agent (C);
A metal coating composition comprising a mixture with an organic solvent (E1). (2) The mixing ratio of the epoxy resin (A), the epoxy-modified silicone resin (B) composed of a block copolymer of a silicone resin and an epoxy resin, and the aminosilane coupling agent (C) is 100% by weight of the epoxy resin (A). 10 to 50 parts by weight of an epoxy-modified silicone resin (B) composed of a block copolymer of a silicone resin and an epoxy resin,
The coating composition for a metal according to (1), wherein the amount is preferably 20 to 40 parts by weight, and the aminosilane coupling agent (C) is 0.5 to 8 parts by weight, preferably 1 to 6 parts by weight. .

(3) An epoxy resin (A), an epoxy-modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin, an aminosilane coupling agent (C) and a number average molecular weight of 100 to 1500. A metal coating composition comprising a mixture of a certain resole type phenol resin (D) and an organic solvent (E2). (4) Epoxy resin (A), epoxy-modified silicone resin (B) composed of a block copolymer of silicone resin and epoxy resin, aminosilane coupling agent (C), resol type phenol resin having a number average molecular weight of 100 to 1500 (D) 100 to 100 parts by weight of the epoxy resin, 10 to 50 parts by weight, preferably 20 to 40 parts by weight of the epoxy-modified silicone resin (B) composed of a block copolymer of a silicon resin and an epoxy resin; 0.5 to 8 parts by weight of the coupling agent (C), preferably 1 to
The above (3), wherein the resol type phenol resin (D) having 6 parts by weight and a number average molecular weight of 100 to 1500 is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight. The coating composition for metals according to item 1.

The metal coating composition of the present invention has mechanical strength and acid resistance equal to or higher than those of conventional phenol epoxy resin-based coatings, and also has extremely excellent heat resistance and oil resistance. Heat resistance of various metal members,
It is useful as a corrosion-resistant paint. The metal coating composition of the present invention exhibits excellent performance as a transportation pipe for petroleum, heavy oil, etc., but also for other natural gas transportation pipes, storage tank inner surfaces, chemical plant steel pipes, inner surfaces of chemical plant tower tanks and the like. It is also suitable as a paint.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin (A) used in the coating composition of the present invention may be any of bisphenol A type epoxy resin, novolak type epoxy resin, cycloaliphatic type epoxy resin, and polyfunctional group type epoxy resin. However, a bisphenol A type epoxy resin is preferred. For curing the epoxy resin, an appropriate amount of a curing agent such as an aliphatic amine or an aromatic amine is added according to the amount of the epoxy resin. The epoxy-modified silicone resin (B) contains one or more epoxy groups in the molecule,
A resin obtained by block copolymerization with polysiloxane. Specific examples include TSK194 (trade name, manufactured by Toshiba Silicone Co., Ltd.)
Trade name SR211 manufactured by Toray Dow Corning Silicone Co., Ltd.
5. Shin-Etsu Chemical Co., Ltd. product name ES1001N. These resins are dissolved in a mixed solvent of an aromatic hydrocarbon and a ketone, and have a nonvolatile content of 40 to 50%.

The aminosilane-based coupling agent (C) is a silane-based compound and has an amino group at a terminal as a functional group. It is characterized in that it can be cured at room temperature by using it as a curing agent for the modified silicone resin. Examples of the coupling agent that can be used include KBM602, KBM603, and KBM manufactured by Shin-Etsu Chemical Co., Ltd.
N903, KBM573, KBE603, KBE903
And the like. The amount of the aminosilane-based coupling agent is appropriately determined based on the amount of the epoxy-modified silicone resin, but is 0.1 to 8 parts by weight based on the epoxy resin (A). If the compounding ratio of the aminosilane coupling agent is less than 0.5 part by weight, the curing is insufficient, and it is difficult to obtain an appropriate coating strength. On the other hand, if it exceeds 8 parts by weight, the amine becomes excessively large and unreacted. These amino compounds are undesirable because they cause the coloring of the coating film, the delay of drying and curing of the coating film, and the deterioration of the coating film properties such as heat resistance and oil resistance.

[0009] Phenolic resins are classified into novolak type and resol type. Novolak-type phenolic resins are hard and brittle when cured, and are not suitable for coating applications requiring abrasion resistance and flexibility. On the other hand, the resol-type phenolic resin has elasticity even after being cured, and is suitable for coating applications. In the embodiments (3) and (4) of the present invention, this resol type phenol resin is used. As the resol type phenol resin used here, an alkali resol type phenol resin obtained by condensing phenol and formaldehyde with triethylamine as a catalyst and having a number average molecular weight of 100 to 1500 is suitable. For example, Asahi Organic Materials Industry Co., Ltd. product name HP8300 is mentioned. This alkali resole type phenol resin can be cured by making the coating mixture alkaline. It can also be cured by adding an appropriate amount of an amine-based curing agent added to cure the epoxy resin and the epoxy-modified silicone resin, or by adding an appropriate amount of aqueous ammonia or an alkali metal or alkaline earth metal hydroxide. .

As the organic solvent (E1) in the paints of the above embodiments (1) and (2), aromatic hydrocarbons such as benzene, toluene and xylene, which are suitable solvents for epoxy resins and epoxy-modified silicone resins, or A mixture of a ketone such as methyl ethyl ketone and methyl isobutyl ketone alone or in a mixed solvent with an amine compound as a curing agent for the resin is used. On the other hand, as the organic solvent (E2) in the paints of the above embodiments (3) and (4), n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol, which are preferable solvents for the alkali resole type phenol resin, are used as the organic solvent (E1). , An alcohol such as isobutyl alcohol, and an aqueous solution containing a suitable amount of aqueous ammonia or a hydroxide of an alkali metal or alkaline earth metal as a curing agent for the alkali resole type phenol resin.

Various additives may be added to the metal coating composition of the present invention, if desired. These additives include pigments (color pigments, extender pigments and anticorrosion pigments), diluents,
Fillers, viscosity modifiers, dispersants, defoamers and the like are used as appropriate according to the purpose. Organic solvent (E1) and organic solvent (E
The amount used in 2) varies depending on the amount of each component in the paint, and an appropriate amount is used in accordance with the amounts of the epoxy resin and the alkali resole type phenol resin mixed. In the application of the paint of the present invention, aromatic hydrocarbons, ketone-based hydrocarbons, alcohols, and water alone or as a mixture are appropriately used as solvents used for viscosity adjustment.

Further, the coating composition of the present invention can be obtained by a spray method,
By brush and roller method, apply directly to the metal surface or apply an undercoat in advance and then dry and cure at room temperature for 1 day or more to obtain a coating film with excellent heat resistance and oil resistance. it can. As the undercoat, an inorganic zinc-based anticorrosion paint or an epoxy zinc-based paint can be used. For example, as the inorganic zinc-based anticorrosion paint, trade names of Dainippon Paint, Zetter SP-2, Zetter OL, Zetter OL-T, Zetter OL-HB, Epoxy zinc paints are trade names Zetter EP-2 and Zetter EP-
2HB or the like is preferably used.

[0013]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. (Examples) A coating composition having the composition shown in Tables 1-1, 1-2 and 1-3 was prepared and applied to a steel sheet surface to form a coating film.
Various evaluation tests were performed. Table 1-1, 1-2, 1-
In 3, the items marked with an asterisk indicate the following contents. * 1 Epoxy resin: Eponyx # 10 (trade name, manufactured by Dai Nippon Paint Co., Ltd.) * 2 Epoxy modified silicone resin: (trade name: SR2115, manufactured by Toray Dow Corning Silicone Co., Ltd.) * 3 Resol type phenol resin: (manufactured by Asahi Organic Materials Industries, Ltd. (HP-8300: number average molecular weight 700 to 800) * 4 Phenol epoxy resin: for baking coating * 5 Aminosilane coupling agent: (trade name KBM603 manufactured by Shin-Etsu Chemical Co., Ltd .; N-β (aminoethyl) α-aminopropylmethoxy) (Silane) * 6 Titanium oxide: (Titanium R-82 manufactured by Ishihara Sangyo Co., Ltd.)
0; rutile type)

Preparation of coating composition-1 Epoxy resin, epoxy-modified silicone resin varnish (nonvolatile content: 50%), aminosilane-based coupling agent are combined in the mixing ratio shown in the table, and precipitated pigment barium sulfate and talc are further used as coloring pigments. , Silica and an anti-settling agent, and further, an organic solvent (E1) in which an amine compound is dissolved so as to have an amine amount necessary for curing the epoxy resin is added. 2/1 hydrogen
The viscosity was adjusted to be suitable for spray coating using the solvent mixed in (1).

Preparation of coating composition-2 Epoxy resin, epoxy-modified silicone resin varnish (non-volatile content: 50%), resol type phenol resin, aminosilane coupling agent are combined in the mixing ratio shown in the table, and further precipitated as a color pigment. An organic solvent (E1) in which a barium sulfate, talc, silica and an anti-settling agent are mixed, and an amine compound is dissolved so as to have an amine amount necessary for curing an epoxy resin, and a resol type phenol resin are cured. After adding a necessary amount of an organic solvent (E2) containing an alkali, an aromatic hydrocarbon and a ketone-based hydrocarbon are added in 2 parts.
The viscosity was adjusted to a level suitable for spray coating using a solvent mixed in the ratio of / 1.

Molding of coating film Next, a zinc-based anticorrosive paint for undercoating, Zetta EP-2 (trade name, manufactured by Dainippon Paint Co., Ltd.) was applied to a steel plate surface (150 × 75 × 3 mm sandblast plate) in advance with a dry film thickness of 40 μm. Each of the coating compositions shown in the table was applied so that the dry film thickness (total film thickness) was 200 μm.
After drying and curing at room temperature for a day, test materials of Examples and Comparative Examples were obtained. However, the test material for the bending resistance test is ASTM D173.
The size was based on 7 method A. The coating film thus obtained was subjected to a cross-cut peeling test, a heat resistance test, and an n-octane immersion test to evaluate the performance of the coating film. The results are shown in Tables 1-1, 1-2 and 1-3. In addition,
Each test method is as follows. The cross-cut test was performed according to [JIS K5400-1979 Paint General Test Method 6.15 Cross-cut Test]. That is, 100 parallel cuts of 4 cm ² are drawn by arranging 11 parallel vertical and horizontal lines at 2 mm intervals, each perpendicular to the cut until it reaches the fabric surface of the test plate through the coating film on the surface of the test material. Apply a cellophane adhesive tape to the coating surface of the grid, then apply the adhesive tape to the coating surface while rubbing it strongly with a spatula. By pulling up, the sum of the numbers of crosscuts remaining without being removed was checked, and the test results were indicated by that number.

Heat-resistant test The coated test plate was placed in a high-temperature gear oven set at 120 ° C. and 140 ° C., and changes in the appearance of the coating film after 1,500 hours were observed. N-octane immersion test The painted test plate was immersed in 90 ° C.
A change in the appearance of the coating film for 20 hours was observed, and a grid test was further performed. Salt water test The coated test plate was immersed in a 3% by weight aqueous solution of NaCl at 90 ° C., the appearance of the coating film was observed after 720 hours, and a grid test was further performed. Abrasion resistance According to ASTM D968-93 (falling sand type abrasion test), the coated test material was dropped down to 60 liters of No. 4 silica sand, and if the abrasion thickness of the coating film was 25 μm or less, abrasion resistance was measured. Was good, and when it was 25 μm or more, it was evaluated as poor. Flex resistance test The painted test material was tested according to ASTM D1737 Method A (conical mandrel type flex test),
The film was evaluated as good when there was no crack in the portion bent at mm, and as poor when cracked.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

The following can be understood from Tables 1-1, 1-2 and 1-3. The coating films of Examples 1 to 5, which are coating compositions containing the epoxy resin of the present invention, epoxy-modified silicone and aminosilane-based coupling agent, are more heat-resistant than the coating films of Comparative Examples 6 and 7, which are the prior art. , Octane resistance,
All of them show excellent performance in salt water resistance, but have slightly weak heat resistance. On the other hand, the coating films of Examples 6 to 14, which are coating compositions containing a predetermined amount of resol-type phenolic resin, also have improved heat resistance, and exhibit excellent performance in abrasion resistance and bending resistance. On the other hand, the coating films of the coating compositions of Comparative Examples 2 and 3, in which the epoxy-modified silicone and the aminosilane-based coupling agent were excessively mixed, showed excellent performances in all of heat resistance, octane resistance, and salt water resistance. Poor in bending resistance.
In addition, the coating film of the coating composition having a small amount of the epoxy-modified silicone and the aminosilane-based coupling agent has heat resistance,
Both octane resistance and salt water resistance are weak. The coating films of the coating compositions of Comparative Examples 1, 4, and 5 in which the amounts of the epoxy-modified silicone and the aminosilane-based coupling agent are small are also inferior in heat resistance, octane resistance, and salt water resistance.

[0022]

The metal coating of the present invention has mechanical strength and acid resistance equal to or higher than those of the conventionally used epoxy resin and phenol epoxy resin, and furthermore has heat resistance, oil resistance, salt water resistance and polishing resistance. It has excellent wear and bending resistance, and has excellent properties as a paint for natural gas transport steel pipes, storage tank inner surfaces, chemical plant steel pipes, chemical plant tower tank inner surfaces, and the like. In particular, when used for painting oil contact surfaces of steel pipes for transporting petroleum, the service life can be remarkably increased as compared with conventional transport steel pipes, and it is advantageous from the viewpoint of maintenance.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08G77 / 42 NUK C08G77 / 42 NUK C08L 63/00 NJS C08L 63/00 NJS NJW NJW NKB NKB ( 72) Inventor Naohito Hoshino 2-5-1 Marunouchi, Chiyoda-ku, Tokyo, Japan, within Mitsubishi Heavy Industries, Ltd. (72) Inventor Osamu Nakai 2-5-1, Marunouchi, Chiyoda-ku, Tokyo, within Mitsubishi Heavy Industries, Ltd.

Claims (4)

[Claims] 1. A mixture of an epoxy resin (A), an epoxy-modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin, an aminosilane coupling agent (C), and an organic solvent (E1). A coating composition for a metal, comprising: 2. The epoxy resin (A), an epoxy-modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin, and an aminosilane coupling agent (C) in a mixing ratio of the epoxy resin (A) An epoxy-modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin is used in an amount of 10 to 5 parts by weight per 100 parts by weight.
0 parts by weight, 0.5% aminosilane coupling agent (C)
The coating composition for metal according to claim 1, wherein the amount is from 8 to 8 parts by weight. 3. An epoxy resin (A), an epoxy modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin, an aminosilane coupling agent (C), and a number average molecular weight of 100 to 1500. A metal coating composition comprising a mixture of a resole type phenol resin (D) and an organic solvent (E2). 4. An epoxy resin (A), an epoxy modified silicone resin (B) comprising a block copolymer of a silicone resin and an epoxy resin, an aminosilane coupling agent (C), and a resol type having a number average molecular weight of 100 to 1500. The mixing ratio of the phenolic resin (D) is epoxy resin 1
Epoxy-modified silicone resin (B) consisting of a block copolymer of silicone resin and epoxy resin with respect to 00 parts by weight
Is 10 to 50 parts by weight, the aminosilane coupling agent (C) is 0.5 to 8 parts by weight, and the number average molecular weight is 100 to 1
The resole type phenol resin (D) which is 500 is 0.1
The metal coating composition according to claim 3, wherein the amount is from 5 to 5 parts by weight.