JP5607516B2 - Metal container - Google Patents

Description

  The present invention relates to a metal container. More specifically, for example, the present invention relates to a metal container that can be suitably used as a high-pressure gas cylinder.

  Since a high-purity gas is required in the semiconductor-related technical field, the inner surface of the high-pressure gas cylinder filled with the high-purity gas is subjected to a cleaning process (for example, see Patent Document 1). This high-pressure gas cylinder may be carried into a clean room that handles semiconductor devices, and if dirt or the like adheres to its outer surface, it will contaminate the air in the clean room. It is required to be clean.

  In general, main dirt on the surface of a metal container such as a high-pressure gas cylinder is a surface coating fragment or peeling piece that is generated when the metal container is transported or collided with another member or rubbed during handling. Or rust caused by corrosion of the metal surface of the metal container exposed by peeling of the coating film. Therefore, in recent years, as a metal container that can be used even in a clean room, a coating film excellent in impact resistance and wear resistance is used in order to prevent the coating film from being broken or peeled off from the surface of the metal container. The development of a metal container is awaited.

  Conventionally, a resin composition for coating a metal plate containing a polyester resin, a rubber-like elastic resin, and a vinyl polymer has been proposed as a paint for forming a coating film having good adhesion and impact resistance to the metal plate. (For example, refer to Patent Document 2).

  However, since the resin composition for coating a metal plate uses a resin component such as a rubber-like elastic resin, the impact resistance is good, but the formed coating film is not hard. Therefore, the coating film may be scratched or a coating film piece may be formed when it collides with or rubs against another member, and corrosion may occur due to the exposure of the metal surface of the metal container.

Japanese Patent Laid-Open No. 9-302489 JP 2009-96853 A

  The present invention has been made in view of the above prior art, and provides a metal container that has a coating film excellent in wear resistance, impact resistance and the like and can be suitably used for a high-pressure gas cylinder or the like. Is an issue.

The present invention
(1) A metal container having a colored coating film on the surface, and a transparent glassy coating film is formed on the surface of the metal container with a paint further containing an organopolysiloxane, an alkoxysilane and an organometallic compound metal container, characterized in that, our and <br/> (2) metal containers, relates to a metal container according to the a high pressure gas cylinder (1).

  The metal container of the present invention has a coating film excellent in wear resistance, impact resistance and the like, and can be suitably used for a high-pressure gas cylinder or the like. Therefore, according to the metal container of the present invention, it is possible to greatly reduce the frequency of renewing the colored coating film in order to maintain wear resistance, impact resistance and the like. Furthermore, the metal container of the present invention can make the seal label affixed to the surface of the metal container adhere to the surface of the metal container as practically without any problem, and can be easily peeled off from the surface of the metal container if desired. Has the advantage that

  The metal container of the present invention has a colored coating film on the surface thereof, and a transparent glassy coating film is further formed on the surface of the metal container.

  Metal containers, especially metal containers for high-pressure gas, are formed with a colored coating film having a predetermined color so that the type of gas filled in the container can be identified from the outside in accordance with the container safety regulations. ing. As the metal container used in the present invention, various metal containers having a colored coating film on the surface can be used including such a metal container for high-pressure gas.

  There are no particular limitations on the type of metal container. For example, a metal container that requires physical properties such as wear resistance and impact resistance on its surface coating is suitably used, including the metal container for high pressure gas as described above. be able to. The material of the metal container is not particularly limited, and examples of the material include iron, copper, brass, stainless steel, manganese steel, chrome molybdenum steel, aluminum, and aluminum alloy. It is not limited only to such illustration.

  The paint used for the colored coating film formed on the surface of the metal container is not particularly limited, and examples thereof include urethane paints, acrylic paints, epoxy paints, epoxy urethane paints, and polyester paints. It is done. Among the coating materials, an acrylic coating material is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance. Further, there is no particular limitation on the thickness of the colored coating film formed on the surface of the metal container, and it is preferable to set appropriately according to the use of the metal container, but the thickness of the colored coating film is Usually, it is about 15 to 30 μm.

  The transparent vitreous coating film formed on the surface of the metal container having a colored coating film on the surface can be formed using, for example, a paint containing organopolysiloxane, alkoxysilane and an organometallic compound.

  Examples of the organopolysiloxane include the formula (I):

Wherein R ¹ and R ² are each independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aryl having 6 to 18 carbon atoms. An oxy group or an aralkyl group having 7 to 18 carbon atoms)
And organopolysiloxane having a siloxanyl group represented by the formula: One type of organopolysiloxane having a siloxanyl group may be used, or two or more types may be used in combination.

In the organopolysiloxane having a siloxanyl group represented by the formula (I), R ¹ and R ² are each independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 6 carbon atoms. An aryl group having 18 to 18 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. Therefore, R ¹ and R ² may be the same group or different groups. Examples of the combination of R ¹ and R ² include a combination in which R ¹ is an alkoxy group having 1 to 12 carbon atoms, R ² is an alkyl group having 1 to 12 carbon atoms, and R ¹ has ¹ to 12 carbon atoms. A combination in which R ² is an aryl group having 6 to 18 carbon atoms, a combination in which both R ¹ and R ² are alkoxy groups having 1 to 12 carbon atoms, and the like. However, the present invention is not limited to such examples. In addition, within the range which does not inhibit the objective of this invention, you may have substituents, such as halogen atoms, such as a fluorine atom and a chlorine atom, and an amino group, for example.

At least one group of R ¹ and R ² is an alkoxy group having 1 to 12 carbon atoms or an aryloxy group having 6 to 18 carbon atoms from the viewpoint of forming a coating film excellent in wear resistance and impact resistance. It is preferable that it is C1-C12 alkoxy group. In addition, from the viewpoint of imparting water repellency and oil repellency to the coating film, at least one of R ¹ and R ² is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a carbon number. A 7 to 18 aralkyl group is preferred. Therefore, from the viewpoint of forming a coating film excellent in wear resistance and impact resistance and imparting water repellency and oil repellency to the formed coating film, R ¹ is an alkoxy group having 1 to 12 carbon atoms, R ² is preferably an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.

  Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. It is not limited to illustration only. Among the alkyl groups, an alkyl group having 1 to 4 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, and a tert-butoxy group. It is not limited only to such illustration. Among the alkoxy groups, an alkoxy group having 1 to 8 carbon atoms is preferable and an alkoxy group having 1 to 4 carbon atoms is more preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  Examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a biphenyl group, a naphthyl group, an anthryl group, and a phenanthryl group, but are not limited to such examples. Among the aryl groups, an aryl group having 6 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  Examples of the aryloxy group having 6 to 18 carbon atoms include phenyloxy group, tolyloxy group, xylyloxy group, biphenyloxy group, naphthyloxy group, anthryloxy group, and phenanthryloxy group. It is not limited to only. Among the aryloxy groups, an aryloxy group having 6 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  Examples of the aralkyl group having 7 to 18 carbon atoms include a benzyl group, a phenylethyl group, a methylbenzyl group, and a naphthylmethyl group, but are not limited to such examples. Among the aralkyl groups, an aralkyl group having 7 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  The number of siloxanyl groups represented by the formula (I) in one molecule of the organopolysiloxane is preferably 1 to 400, more preferably 1 to 400, from the viewpoint of forming a coating film excellent in wear resistance and impact resistance. 200, more preferably 3 to 100, and even more preferably 5 to 50.

  Examples of the terminal group of the organopolysiloxane having a siloxanyl group represented by the formula (I) include a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and 6 to 6 carbon atoms. Examples thereof include an aryl group having 18 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, and a silyl group, but the present invention is not limited to such examples. As the alkyl group having 1 to 12 carbon atoms, the alkoxy group having 1 to 12 carbon atoms, the aryl group having 6 to 18 carbon atoms, the aryloxy group having 6 to 18 carbon atoms and the aralkyl group having 7 to 18 carbon atoms, What was illustrated can be mentioned.

  Examples of the silyl group include silyl groups, methylsilyl groups, ethylsilyl groups, propylsilyl groups, dimethylsilyl groups, diethylsilyl groups, dipropylsilyl groups, trimethylsilyl groups, triethylsilyl groups, and tripropylsilyl groups. Silyl group having 1 to 3 alkyl groups of 1 to 4; methoxysilyl group, ethoxysilyl group, propoxysilyl group, dimethoxysilyl group, diethoxysilyl group, dipropoxysilyl group, trimethoxysilyl group, triethoxysilyl Group, a silyl group having 1 to 4 C 1-4 alkoxy groups such as a tripropoxysilyl group; a methoxymethylsilyl group, an ethoxymethylsilyl group, a propoxymethylsilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group , Dipropoxymethylsilyl group, An alkoxy group having 1 to 4 carbon atoms and an alkyl group having 1 to 4 carbon atoms such as a remethoxymethylsilyl group, a triethoxysilyl group, a tripropoxysilyl group, a methoxydimethylsilyl group, an ethoxydimethylsilyl group, and a propoxydimethylsilyl group; Although the silyl group etc. which have are mentioned, this invention is not limited only to this illustration.

  Among the end groups of the organopolysiloxane having a siloxanyl group represented by the formula (I), from the viewpoint of forming a hard coating film, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. Group and silyl group are preferable, an alkoxy group having 1 to 12 carbon atoms is more preferable, an alkoxy group having 1 to 8 carbon atoms is more preferable, and an alkoxy group having 1 to 4 carbon atoms is particularly preferable.

  Examples of alkoxysilane include, for example, formula (II):

(In the formula, R ³ is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 6 to 18 carbon atoms. An aryloxy group or an aralkyloxy group having 7 to 18 carbon atoms, R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms or a carbon number 7 Represents -18 aralkyl groups)
And alkoxysilanes represented by the formula: Only one type of alkoxysilane may be used, or two or more types may be used in combination.

In the formula (II), R ³ is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 6 to 6 carbon atoms. An aryloxy group having 18 carbon atoms or an aralkyloxy group having 7 to 18 carbon atoms. R ³ is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms from the viewpoint of forming a coating film excellent in wear resistance and impact resistance. It is preferable.

In the formula (II), R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. Therefore, R ⁴ , R ⁵ and R ⁶ may be the same group or different groups.

In the formula (II), at least one group of R ³ , R ⁴ , R ⁵ and R ⁶ has 1 to 12 carbon atoms from the viewpoint of forming a coating film excellent in wear resistance and impact resistance. An alkyl group is preferred.

  In the formula (II), examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and an isooctyl group. Although mentioned, this invention is not limited only to this illustration. Among the alkyl groups, an alkyl group having 1 to 8 carbon atoms is preferable and an alkyl group having 1 to 4 carbon atoms is more preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  In the formula (II), examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a biphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and the like. Is not to be done. Among the aryl groups, an aryl group having 6 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  In the formula (II), examples of the aralkyl group having 7 to 18 carbon atoms include a benzyl group, a phenylethyl group, a methylbenzyl group, and a naphthylmethyl group, but are not limited to such examples. Among the aralkyl groups, an aralkyl group having 7 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  In the formula (II), examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, and a tert-butoxy group. However, the present invention is not limited to such examples. Among the alkoxy groups, an alkoxy group having 1 to 4 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  In the formula (II), examples of the aryloxy group having 6 to 18 carbon atoms include phenyloxy group, tolyloxy group, xylyloxy group, biphenyloxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group, and the like. Although it is mentioned, it is not limited only to this illustration. Among the aryloxy groups, an aryloxy group having 6 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  In the formula (II), examples of the aralkyloxy group having 7 to 18 carbon atoms include a benzyloxy group, a phenylethyloxy group, a methylbenzyloxy group, a naphthylmethyloxy group, and the like. It is not something. Among the aralkyloxy groups, an aralkyloxy group having 7 to 12 carbon atoms is preferable from the viewpoint of forming a coating film excellent in wear resistance and impact resistance.

  Suitable examples of the alkoxysilane represented by the formula (II) include methoxymethylsilane, ethoxymethylsilane, propoxymethylsilane, dimethoxymethylsilane, diethoxymethylsilane, dipropoxymethylsilane, methoxydimethylsilane, and ethoxydimethylsilane. , Silanes having an alkoxy group having 1 to 4 carbon atoms and an alkyl group having 1 to 12 carbon atoms such as propoxydimethylsilane and isooctyltrimethoxysilane, and the like, but the present invention is limited to such examples only. is not. These alkoxysilanes may be used alone or in combination of two or more.

  The amount of alkoxysilane is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, from the viewpoint of forming a coating film excellent in wear resistance and impact resistance per 100 parts by weight of organopolysiloxane. From the viewpoint of forming a coating film excellent in wear resistance and impact resistance, it is preferably 80 parts by weight or less, more preferably 60 parts by weight or less.

  The organometallic compound has properties as a curing agent for organopolysiloxane and alkoxysilane.

As the organometallic compound, for example, the formula (III):
(R ⁷ ) _m M (R ⁸ ) _n (III)
Wherein M is a metal atom, R ⁷ is an alkyl group having 1 to 10 carbon atoms, R ⁸ is an acyloxy group having 1 to 18 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, and m is the number of R ^7. 0 or a positive integer, n is 0 or a positive integer indicating the number of R ⁸ , and the sum of m and n indicates the valence of M)
And alkyl metal fatty acid salts and metal alkoxides. The organometallic compound may be used alone or in combination of two or more.

  In the formula (III), M is a metal atom. Suitable metal atoms include, for example, titanium, tin, zirconium, aluminum, cobalt and the like. Among these, titanium, tin and aluminum are preferable from the viewpoint of increasing the curing rate and improving the coating film performance.

In the formula (III), R ⁷ is an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-hexyl group, an ethylhexyl group, and an n-octyl group. However, the present invention is not limited to such examples. Among R ⁷ , an alkyl group having 6 to 10 carbon atoms is preferable.

In the formula (III), R ⁸ is an acyloxy group having 1 to 18 carbon atoms or an alkoxy group having 1 to 8 carbon atoms. Examples of the acyloxy group having 1 to 18 carbon atoms include formyloxy group, acetyloxy group, propionyloxy group, butyryloxy group, heptanoyloxy group, decanoyloxy group, dodecanoyloxy group and the like. Is not limited to such examples. Examples of the alkoxy group having 1 to 8 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, and a tert-butoxy group. It is not limited only to such illustration. Among R ⁸ , an acyloxy group having 10 to 14 carbon atoms or an alkoxy group having 1 to 4 carbon atoms is preferable.

In the formula (III), m is 0 or a positive integer indicating the number of R ⁷ . n is 0 or a positive integer indicating the number of R ⁸ . The sum of m and n indicates the valence of the metal atom M.

  The amount of the organometallic compound is preferably 0.001 to 1.5 mol, more preferably 0.01, from the viewpoint of forming a coating film excellent in wear resistance and impact resistance per mol of alkoxysilane. -1.0 mol.

  The coating material can be prepared by mixing organopolysiloxane, alkoxysilane and an organometallic compound, but an organic solvent can be used if necessary.

  Examples of the organic solvent include aromatic hydrocarbon solvents such as benzene, toluene and xylene; aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, octane and isononane; alcohol solvents such as ethanol, isopropanol and butanol; Examples include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; and ether solvents such as propylene glycol monomethyl ether and ethylene glycol monobutyl ether. It is not limited to only.

  The amount of the organic solvent is not particularly limited. Usually, from the viewpoint of improving the dispersion stability, the content of the non-volatile content in the coating is 10% by weight or more, preferably 15% by weight or more, thereby improving the coating property. Therefore, it is desirable to adjust the amount to 40 wt% or less, preferably 30 wt% or less.

  In addition, it is preferable to use a surface smoothing agent for the said coating material from a viewpoint of improving the smoothness of the coating film formed as needed, and improving the wettability with respect to a colored coating film.

  Examples of the surface smoothing agent include hydrocarbon compounds such as isoparaffin, solvent naphtha and mineral spirit, alcohol solvents such as heptanol and octanol, and ketone solvents such as diisobutyl ketone and cyclohexanone. It is not limited to illustration only. Among the surface smoothing agents, an isoparaffin-based hydrocarbon compound is preferable from the viewpoint of improving the smoothness of the formed coating film. As the isoparaffinic hydrocarbon compound, from the viewpoint of enhancing the smoothness of the formed coating film, isoparaffin having 9 to 12 carbon atoms, solvent naphtha, mineral spirit, and the like are preferable.

  The amount of the surface smoothing agent is preferably 1 part by weight or more, more preferably 3 parts by weight or more, and still more preferably from the viewpoint of enhancing the surface smoothness per 100 parts by weight of the total amount of the organopolysiloxane, alkoxysilane and organometallic compound. Is 5 parts by weight or more, and preferably forms 30 parts by weight or less, more preferably from the viewpoint of forming a coating film excellent in wear resistance and impact resistance and suppressing dripping of the paint during coating. Is 20 parts by weight or less.

  The transparent vitreous coating film can be formed, for example, by applying the paint on a colored coating film formed on the surface of a metal container.

  Examples of the method for applying the paint include an air spray method, a roll coater method, a flow coater method, and a dipping method. However, the present invention is not limited to such examples. After forming a coating film, a transparent glassy coating film can be formed by drying the formed coating film. The formed coating film can be dried by leaving it in the air as it is, or by heating it at a temperature of about 50 to 100 ° C. for about 10 to 30 minutes, for example.

  Since the thickness of the formed transparent glassy coating film after drying differs depending on the type of metal container and the like, it cannot be determined unconditionally, so it is preferable to adjust appropriately according to the type of the metal container, Usually, it is about 3-20 micrometers.

  Since the glassy coating film formed on the surface of the metal container obtained as described above is excellent in wear resistance, impact resistance, etc., the metal on which the glassy coating film is formed on the surface The container can be suitably used for, for example, a high-pressure gas cylinder.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Production Example 1
A manganese steel plate having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm was used as a base material. On one surface of this steel plate, a white urethane paint [Dainippon Paint Co., Ltd., trade name: View Urethane SS] was dried. The coating film was applied to a thickness of about 30 μm, heated in the atmosphere at 70 ° C. for 30 minutes, and then allowed to stand in the atmosphere for 7 days to dry naturally to form a coating film. A base material on which was formed was obtained.

Production Example 2
Instead of the white urethane paint used in Production Example 1 (trade name: View Urethane SS, manufactured by Dainippon Paint Co., Ltd.), a white acrylic resin paint (manufactured by Perfect Co., Ltd., trade name: SS Coated Water) was used. Except for this, a substrate on which a conventional coating film was formed was obtained in the same manner as in Production Example 1.

Example 1
In the formula (I), 12.5 g of an organopolysiloxane in which R ¹ is a methoxy group, R ² is a methyl group, a terminal group is a methyl group, and the average number of siloxanyl groups in one molecule of the organopolysiloxane is 20, A paint was prepared by mixing 5.0 g of silane, 0.75 g of tin tetraisopropoxide, 0.2 g of titanium tetraisopropoxide, 50 g of toluene as an organic solvent and 20 g of mineral spirit.

  Next, the coating material is applied on the coating film of the base material obtained in Production Example 1 so that the thickness of the coating film after drying is about 10 μm, heated at 70 ° C. for 30 minutes, and then 7 days. By leaving it in the air, it was naturally dried to form a coating film, and two test pieces on which a transparent glassy coating film was formed were produced.

Example 2
In the formula (I), 12.5 g of an organopolysiloxane in which R ¹ methoxy group, R ² is a methyl group, an end group is an alkoxy group, and the average number of siloxanyl groups in one molecule of the organopolysiloxane is 40, isooctyltrimethoxy A paint was prepared by mixing 5.0 g of silane, 0.75 g of dioctyltin laurate, 0.2 g of titanium tetraisopropoxide, 50 g of toluene as an organic solvent and 20 g of mineral spirit.

  Next, in the same manner as in Example 1, the paint was applied on the coating film of the base material obtained in Production Example 1 to produce two test pieces on which a transparent glassy coating film was formed.

Example 3
In the formula (I), 12.5 g of an organopolysiloxane in which R ¹ is a methoxy group, R ² is a methyl group, a terminal group is a methyl group, and the average number of siloxanyl groups in one molecule of the organopolysiloxane is 20, A paint was prepared by mixing 5.0 g of silane, 0.18 g of tin tetraisopropoxide, 0.05 g of titanium tetraisopropoxide, 50 g of toluene as an organic solvent and 20 g of mineral spirit.

  Next, on the coating film of the base material obtained in Production Example 2, the paint was applied so that the thickness of the dried coating film was about 10 μm, heated at 70 ° C. for 30 minutes, and then 7 days. By leaving it in the air, it was naturally dried to form a coating film, and two test pieces on which a transparent glassy coating film was formed were produced.

Example 4
In the formula (I), 12.5 g of an organopolysiloxane in which R ¹ methoxy group, R ² is a methyl group, an end group is an alkoxy group, and the average number of siloxanyl groups in one molecule of the organopolysiloxane is 40, isooctyltrimethoxy A paint was prepared by mixing 5.0 g of silane, 0.18 g of dioctyltin laurate, 0.05 g of titanium tetraisopropoxide, 50 g of toluene as an organic solvent and 20 g of mineral spirit.

  Next, in the same manner as in Example 3, the paint was applied on the coating film of the base material obtained in Production Example 2 to produce two test pieces on which a transparent glassy coating film was formed.

Reference example 1
The base material obtained in Production Example 1 was used as a comparative test piece, and two test pieces were produced.

Reference example 2
The base material obtained in Production Example 2 was used as a comparative test piece, and two test pieces were produced.

Experimental Example Using the test pieces obtained in Example 1, Example 2, Reference Example 1 and Reference Example 2, the physical properties of the coating film formed on each test piece were evaluated based on the following methods. The results are shown in Table 1.

(Abrasion resistance)
The evaluation was performed according to the wear test method using a wear wheel described in JIS K7204. Abrasion wheel CS-10 is attached to a Taber abrasion tester (Model 5130, manufactured by Toyo Seiki Co., Ltd.) in an atmosphere with a temperature of 18-19 ° C. and a relative humidity of 55-58%, and the specimen is rotated 250 times with a load of 500 g. The mass of the test piece before and after the test was measured to determine the amount of wear loss.

(Impact resistance)
Each coated plate is allowed to stand for 24 hours in a constant temperature and humidity room at a temperature of 20 ° C. ± 1 and a relative humidity of 75 ± 2%, and then the test piece is tested using a DuPont impact tester specified in JIS K5600-5-3 (1999). With the coating film facing upwards, a weight of 500 g is dropped from a height of 20 cm onto a striker (1/2 inch) to check whether the coating film is cracked or peeled off. Based on the evaluation.
(Evaluation criteria)
○: No cracking or peeling occurred in the formed coating film.
X: Generation | occurrence | production of a crack or peeling is recognized by the formed coating film.

〔transparency〕
The coating film formed using each test piece obtained in each example was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: The formed glassy coating film is transparent, and the coating film of the white urethane coating formed on the surface of the steel sheet can be clearly recognized.
Δ: The formed glassy coating film is slightly turbid and transparent, and the coating film of the white urethane coating formed on the surface of the steel plate can be recognized.
X: The formed glassy coating film is opaque.

[Seal label adhesive properties]
A seal label of 50 mm length and 50 mm width (Kobayashi Create Co., Ltd.) was affixed to the test piece, and after 7 days in the room, the state when the seal label was peeled off was observed and evaluated based on the following evaluation criteria. did.
(Evaluation criteria)
○: The entire seal label is in close contact, but can be peeled off at once.
Δ: The entire seal label is in close contact, but cannot be peeled off at once, and the label is torn and needs to be peeled off in several degrees.
X: The whole seal label is in close contact, but it cannot be easily peeled off, leaving a piece of paper that is not torn and the label is torn.

  From the results shown in Table 1, the test pieces obtained in Examples 1 and 2 are formed with a transparent glassy coating film, and therefore, compared to the test piece obtained in Reference Example 1, wear resistance is obtained. It can be seen that the properties are remarkably improved and the impact resistance is also excellent. Moreover, since the transparent glassy coating film was formed similarly to the test piece obtained in Examples 1 and 2 also for the test piece obtained in Examples 3 and 4, the test obtained in Reference Example 2 was performed. It can be seen that the wear resistance is remarkably improved as compared with the piece, and the impact resistance of the base material obtained in Production Example 2 is maintained without being impaired.

  In addition, all of the test pieces obtained in each example can be adhered to the surface of the test piece without any practical problem from the measurement result of the seal label adhesive property, and from the test piece if desired. It can be seen that it can be easily removed.

  Therefore, the metal container in which the transparent glassy coating film obtained in each Example is formed is a fragment of the coating film by colliding or rubbing with other members when the metal container is transported or handled. Since the metal surface of the metal container is exposed and corroded due to peeling of the coating film, it can be suitably used, for example, in a clean room.

Claims (2)

A metal container having a colored coating film on the surface, wherein a transparent glassy coating film is further formed on the surface of the metal container with a paint containing organopolysiloxane, alkoxysilane and an organometallic compound. Metal container. Metal containers, metal container according to claim 1 which is a high pressure gas cylinder.