KR101616330B1 - Composition of volatile corrosion inhibitor and corrosion inhibitor film using the same - Google Patents

Abstract

The present invention relates to a rust preventive composition having excellent rust resistance and a rust preventive film using the rust preventive composition. The rust-preventive composition includes calcium nitrite alone and a mixture thereof, a cation exchangeable compound, calcium oxide and low density polyethylene, , A vapor-proof rust-preventive composition capable of remarkably improving the rust-preventive properties including a combination of these resins with a rust-preventive component and additives, and an anti-rust film using the rust-preventive composition, thereby improving the parts packaging field of various automobiles, shipbuilding, heavy industrial parts and ferrous metals Can be imparted.

Description

TECHNICAL FIELD The present invention relates to a high performance vapor-resistant rust preventive composition and a rust-inhibitive film comprising the same,

The present invention relates to a high-performance vapor-proof rust-preventive composition and a rust-preventive film comprising the same, and more particularly to a high-performance vapor-proof rust-preventive composition and a rust-preventive film containing the same, which improve foreign matter formation, discoloration and rust- .

Conventionally, various methods such as rust preventive oil, grease, paint, plating, silica and other dehumidifying agents and vacuum packaging have been used in order to prevent corrosion of metallic products. However, due to limitations in application, workability and post- Are being studied extensively.

As the vapor-proof rust inhibitor of the rust-preventive film, a nitrite-based metal compound, an amine nitrite, an organic amine, a carboxylic acid and a salt thereof may be used alone or in combination of two or more. Currently, as a typical rust- Compounds such as lithium nitrite, sodium nitrite, or potassium nitrite are used as a nitrite based metal compound. In general, sodium nitrite is preferred in the nitrite metal compound, and 2, 4, 6-trisubstituted phenol compounds such as BHT (2,6-di-t-butyl-4-methyl phenol) .

The vapor corrosion rusting film using calcium nitrite has a superior initial jar test and long term durability against rusting film using sodium nitrite, but has a problem of foaming due to formation of insoluble salt by hydrolysis, discoloration and high hygroscopicity .

Republic of Korea Publication No. 10-2006-0017630 (February 24, 2006)

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide an anticorrosive film which contains an ion exchangeable compound such as a low density polyethylene resin, calcium nitrite and zeolite for improving the rustproofing durability of existing anticorrosive films, And a vapor corrosion inhibitor composition capable of eliminating and suppressing the problem of formation of foreign substances such as calcium hydroxide formed on the metal surface in the parts packaging of ferrous metals by the existing calcium nitrite containing an ion exchange compound such as Na-bentonite And an antirust film comprising the same.

The present invention relates to a vapor-resistant rust-preventive composition and a rust-preventive film comprising the same.

One aspect of the present invention relates to a method for producing a water-insoluble inorganic salt, which comprises (A) 20 to 40% by weight of a nitrite metal salt selected from calcium nitrite or sodium nitrite, (B) 5 to 20% by weight of a cation exchangeable compound, ) 30 to 70% by weight of a low density polyethylene (LDPE) resin having a melt index (Melt Index, ASTM D 1238) of 5 to 30 g / 10 min.

In the present invention, the cation exchangeable compound may be any one or two or more selected from Na-bentonite, zeolite or crosslinked or non-crosslinked sodium polyacrylate salt, and the average particle diameter of the cation exchange compound is 5 to 100 탆 .

In the present invention, the hygroscopic inorganic material may be any one or two or more selected from silica, activated alumina and calcium oxide, and the average particle size may be 5 to 100 탆.

Another aspect of the invention relates to a rustproof film comprising a vapor-barrier rust-inhibiting composition.

The vapor-proof rust-preventive composition and the rust-preventive film using the same according to the present invention are superior to the vapor-barrier rust-preventive film using sodium nitrite, and have a remarkable effect on the formation of foreign substances such as calcium hydroxide on the metal surface by calcium nitrite and the foaming problem , It is possible to give improved rust prevention to various automobile, shipbuilding, heavy industrial parts and parts of the ferrous metals field.

1 shows discoloration and foreign matter formation on a vapor-resistant rustproof film containing calcium nitrite alone.
2 shows a calcium ion exchange reaction with a cation exchange compound.
3 shows the results of the Jar test according to Examples 1 to 4 or Comparative Examples 1 and 2.
4 shows the temperature and humidity cycle for the rust prevention test.
FIG. 5 shows the results of the temperature and humidity cycle tests according to Examples 1 to 3.
Fig. 6 shows the results of the temperature and humidity cycle tests according to Example 4 or Comparative Examples 1 and 2. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It should be understood, however, that the invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In addition, the following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms. The following drawings may be exaggerated in order to clarify the spirit of the present invention. Also, throughout the specification, like reference numerals designate like elements.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

(A) 20 to 40% by weight of a nitrite metal salt selected from calcium nitrite or sodium nitrite, (B) 5 to 20% by weight of a cation exchangeable compound, (C) 1 to 10% by weight of a hygroscopic inorganic compound, (D) 30 to 70% by weight of a low density polyethylene (LDPE) resin having a melt index (ASTM D 1238) of 5 to 30 g / 10 min.

The inventors of the present invention have conducted intensive studies to solve problems such as the formation of insoluble salts by hydrolysis and the occurrence of foaming due to discoloration and high hygroscopicity of a nitrite compound used as a vapor corrosion inhibitor, It is possible to inhibit the discoloration of the film due to the nitrite compound and the formation of the foreign material of the insoluble salt, and the present invention has been accomplished.

In the present invention, the metal nitrite (A) as the chromate salt acts as an anode inhibitor, that is, a passivating agent, and has an extremely high corrosion inhibiting rate (90% or more) even at a low concentration. Examples of the nitrite metal salt include at least one selected from the group consisting of calcium nitrite, lithium nitrite, sodium nitrite, and potassium nitrite. But it is not limited, and calcium nitrite is most preferably used. Particularly, calcium nitrite has a characteristic of having high absorbency compared to other nitrite metal salts, so that ion exchange reaction is active.

It is also preferred to use 2,4,6-trisubstituted phenol compounds such as BHT (2,6-di-t-butyl-4-methylphenol) to promote the vaporization of the metal nitrite. At this time, the addition amount of the phenol compound is freely adjustable within a range that does not impair the physical properties of the rust-preventive film according to the present invention.

The cation-exchangeable compound may be selected from Na-bentonite, zeolite or sodium polyacrylate salt, but the present invention is not limited thereto.

In the present invention, the bentonite is a commercial term for clay mainly composed of smectite, and the specific clay properties of bentonite depend on the crystal chemical properties of the smectite mineral. One of the other unique properties of sodium bentonite is its high adsorption capacity for calcium ions and the like, which is due to the cation exchange (CEC) of smectite.

The crystal structure of the zeolite is characterized in that it has a cavity structure in which cations exchangeable with water molecules can be located. This is a mineral having the most effective ion exchange capacity in the natural world, and the montmorillonite has a zeolite Has an ion exchange capacity of 300 to 400 meq / 100 g.

The cation exchange ability of the bentonite and the zeolite is such that ions such as hydrolyzed calcium nitrate (Ca ²⁺ ) are formed on the inside and the surface of the vapor-phase rustproofing film to form an ion exchange reaction as shown in FIG. 2, Inhibiting and eliminating the formation of the same insoluble salt.

The average particle diameter of the cation-exchangeable compound may be 5 to 100 mu m. If the thickness is less than 5 탆, coating defects may occur during film formation. If the thickness exceeds 100 탆, the transparency of the anticorrosion film may be decreased.

In the present invention, the hygroscopic inorganic material is added in order to absorb and remove the remaining moisture to eliminate the foaming phenomenon that may occur in the extrusion processing of the composition. Examples of the hygroscopic inorganic material may include one or more selected from silica, activated alumina and calcium oxide, but the present invention is not limited thereto.

In the present invention, the average particle diameter of the hygroscopic inorganic material may be 5 to 100 탆. If the thickness is less than 5 탆, coating defects may occur during film formation. If the thickness exceeds 100 탆, the transparency of the anticorrosion film may be decreased.

In the present invention, low-density polyethylene acts as a base resin of the rust-preventive film, and is added to improve the economical efficiency and mechanical properties of the film when it is formed. Especially, it is preferable to use low-density polyethylene (LLDPE) .

The low density polyethylene preferably has a melt index according to ASTM D1238 of 5 to 30 g / 10 min. When the melt index is in the above range, no defect is caused in the film to be produced, so that extrusion processing is easy and rust prevention efficiency can be maintained.

The vapor-resistant rust-preventive composition according to the present invention comprises (A) 20 to 40% by weight of a metal nitrite, (B) 5 to 20% by weight of a cation exchangeable compound, (C) 1 to 10% by weight of a moisture- Index, ASTM D 1238) of 5 to 30 g / 10 min. In this composition, the flexibility, workability, and rust prevention of the film are maximized, formation of insoluble salts is suppressed, and discoloration and foaming can be prevented.

The vapor-proof rust-preventive composition according to the present invention may further contain additives such as an antistatic agent, an ultraviolet stabilizer, an antioxidant, and a light absorber in addition to the above composition. The amount of the additive can be adjusted freely according to the purpose, and the present invention is not limited thereto, but it is preferable to add 0.01 to 1 part by weight to 100 parts by weight of the vapor-barrier rust-preventive composition.

The present invention can be made into a rust-inhibiting film by processing the above-described vapor-barrier rust-inhibiting composition. In this case, the production method is not limited, and a method commonly used in the art, such as a casting method or an extrusion method, may be used. Further, although the thickness of the film is not limited, it is preferable that the thickness of the film is maintained at 20 to 120 占 퐉 to maintain the rustproofing property and the shape stability.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

The composition of the composition prepared according to the present invention and the method for measuring the physical properties thereof are as follows.

(Composition)

The materials used in the following examples and comparative examples are shown in Table 1 below.

[Table 1]

(JAR test)

The JAR test confirms the qualitative comparison performed in the sealed JAR. The container, 1010 coupon, grinder, dryer, incubator and the like were used according to KS T 1085 and evaluated by visual observation at levels 0 to 3.

(Temperature and humidity cycle)

1010 steel plates of 90 × 50 mm in area were completely sealed with rustproofing shrink film using ethanol and acetone, and then exposed to a temperature and humidity cycle of 40 ± 15 ° C. and 94 ± 1% relative humidity for 30 cycles using a thermo-hygrostat Evaluate the corrosion resistance.

4, the surface of the test piece was washed with water and methanol. The surface of the test piece was scanned under the condition of 300 dpi using a V700PHOTO model of EPSON, and the surface of the test piece was scanned using Scion Image program The rust area was calculated. The mean value of the three test specimens was used.

(Discoloration and foreign matter)

After the temperature and humidity cycle test, the degree of discoloration of the rust-preventive film and the degree of foreign matter contamination of the 1010 steel plate were visually evaluated. The results are shown in Table 3.

○: Very good: Normal ×: Poor

(Examples 1 to 4 and Comparative Examples 1 and 2)

The compositions shown in the following Table 2 were mixed, put into an extruder heated at an average temperature of 120 占 폚, heated and melted to prepare pellets. The prepared pellets were mixed with linear low density polyethylene (737, Hanwha Chemical) to 3 wt%: 97 wt%, and then extruded to a thickness of 100 탆 using a hollow extruder to prepare a vapor-resistant rust preventive film. The physical properties of the prepared film were measured and are shown in Table 3.

[Table 2]

[Table 3]

As a result of evaluating the rust resistance (JAR test, temperature and humidity cycle test) according to the above examples, as shown in Table 3 and FIGS. 5 and 6, the rust resistance against the JAR test and the temperature and humidity cycle test of Comparative Example 1 was The rust-inhibiting property of Example 4 was level 3 and the rusting resistance was 0.000%, and it was confirmed that the rustproofing property according to the present invention was remarkably improved.

As a result of evaluating the discoloration and foreign matter formation according to the above examples, it was confirmed that the discoloration and foreign matter formation of Comparative Example 2 were remarkably improved in Example 4 as shown in Table 3 above.

Claims (6)

(A) 20 to 40% by weight of a nitrite metal salt selected from calcium nitrite or sodium nitrite, (B) a cation exchange compound 5 selected from Na-bentonite, zeolite or crosslinked or unmodified sodium polyacrylate salt (D) a melt index (ASTM D 1238) of 5 to 30 g / 10 min, and (C) 1 to 10 wt% of at least one selected from silica, activated alumina and calcium oxide, By weight of a low density polyethylene (LDPE) resin. delete The method according to claim 1,
Wherein the cation exchangeable compound has an average particle diameter of 5 to 100 占 퐉. delete The method according to claim 1,
Wherein the hygroscopic inorganic material has an average particle diameter of 5 to 100 mu m. A rust-preventive film comprising the vapor-barrier rust-inhibiting composition of any one of claims 1, 3 and 5.

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