JPS5850677B2 - Surface oil composition for surface treated steel sheets - Google Patents

Description

[Detailed description of the invention] The present invention provides anti-rust properties for use in surface-treated steel sheets such as tinplate,
This invention relates to a surface oil composition with excellent lubricity, degreasing properties, and coating properties.

-JIJ-Ki includes prevention of abrasion during transportation,
A very thin layer of surface oil is applied for the purpose of lubrication during painting and can manufacturing processes.

Conventionally, surface oils generally include vegetable oils such as cottonseed oil and palm oil, and dioctyl sebacate (hereinafter abbreviated as DO8).
Synthetic esters such as

However, although vegetable oils such as palm oil have good lubricity within a certain period of time, since they have unsaturated bonds in the oil, oxidative polymerization reactions occur and the lubricity deteriorates.

Additionally, it has the disadvantage that it tends to cause coating defects called eyeholes during coating.

In the case of DO8, it retains lubricity for a relatively long period of time and has good paintability under normal conditions, but if the amount of oil applied is increased somewhat to improve lubricity, the oil may become uneven due to movement of the oil. That is, it has been pointed out that eye holes are likely to occur in areas where the oil film is thick as a drawback.

In terms of tinplate manufacturing, conventionally the amount of tin plating was 2.5~
15. ! Although only i'/m' products were manufactured,
As the cost of tinplate decreases and its uses expand, the amount of tin plating has increased to 2.5,! There is an increasing demand for tinplate with a low plating amount of i'/@2 or less.

These tin plates with a low tin coating have extremely poor rust resistance compared to conventional tin plates, and the lubricity of the tin plate itself is also poor.

For this reason, rust prevention and high lubricity are newly required in addition to the performance required of conventional surface oils.

In addition, the performance required for the use of tinplate with a low amount of tin adhesion is that, like conventional tinplate, it can be directly painted and printed without pretreatment such as degreasing, and it has good lubricity and degreasing properties. There are contradictory demands such as excellence.

To improve only rust prevention and lubricity, use a general rust prevention lubricant (
The problem can be easily solved by using NP-7, 8, 9, 10), but since these anti-rust lubricants use mineral oil as the base oil, they have the disadvantage of poor paintability and degreasing properties. are doing.

In addition, the rust inhibitor that is added is oxidized paraffin wax,
Mainly sulfonates and amines are used, and because they are highly toxic, they cannot be used as surface oils for tinplate, tin-free steel, etc. used in food container materials.

Under these circumstances, the inventors of the present invention, Nagisa et al., first searched for various oil-based substances that have good affinity with paints.

It is generally known that ester compounds have better affinity with paints than mineral oils such as liquid paraffin and spindle oil.

Among ester compounds, synthetic esters used in plasticizers and the like have better oxidation stability than natural glycerides such as animal and vegetable oils, and are considered to be better.

Next, in order to improve rust prevention, it is necessary to form a denser film on the tinplate surface.

For this purpose, it is necessary to cover a wider area with the film with the same capacity, and it is necessary to improve wettability.

An effective way to improve wettability is to lower the surface tension and viscosity of oil.

Although it is generally known that the use of surfactants is effective in lowering the surface tension, not all surfactants can be used.

Since the solubility of surfactants differs depending on the type of oil, the selection of surfactants is an important point.

Next, if it becomes possible to form an extremely thin and dense film, even if the amount of oil applied is reduced, a thin and uniform film will be formed, improving rust prevention, lubricity, and paintability. .

Furthermore, by reducing the amount of oil applied and obtaining the required performance, it becomes possible to improve the apparent degreasing performance.

As a result of repeated studies on various types based on such technical ideas, we found that at least one citric acid ester compound having the structural formula as detailed below, and at least one fatty acid ester compound (wetting property) as described in detail below. It has been found that good performance can be achieved by uniformly adding the required amount of the additive (improving agent), leading to the present invention.

The purpose of the present invention is to apply a very thin coating to surface-treated steel plates such as tinplate, tin-free steel, and low-grade steel to improve paintability and improve paintability.
The object of the present invention is to provide a surface oil composition that can improve lubricity, rust prevention, and degreasing properties.

[In the above formula, R1, R2, R3 are hydrogen or 1 to 1
alcohol residues 8 carbon atoms south, at least one of which is an alcohol residue, and R
4 is hydrogen or a carboxylic acid residue having 1 to 18 carbon atoms.
One or more compounds selected from the group consisting of glycerin fatty acid ester, propylene glycol monofatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan acid ester, and triethanolamine are added in a total of 0.1 to 10φ. The above object can be achieved by applying a very thin layer of a homogenized surface oil composition to tinplate, tin-free steel, and cold-rolled steel sheets.

In the above general formula, at least one of R1, R2, and R3 is an alcohol residue having 1 to 4 carbon atoms,
Even better, R4 is hydrogen or a carboxylic acid residue containing 1 to 4 carbon atoms.

Suitable examples of citric acid esters as base oils include triethyl citrate, acetyl triethyl citric acid, tributyl citrate, acetyl tributyl citric acid, and acetyl trioctyl citric acid. can be used.

Suitable examples of wettability improvers for these base oils include:
Examples of glycerin fatty acid esters include stearic acid monoglyceride, oleic acid monoglyceride, and lauric acid monoglyceride, and examples of sorbitan fatty acid esters include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, Examples include sorbitan trioleate and sorbitan sesquioleate, and among polyoxyethylene sorbitan fatty acid esters,
To mention polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate I can do it.

Among these, particularly preferred are oleic acid monoglyceride, sorbitan monooleate, lauric acid monoglyceride, sorbitan monolaurate, sorbitan trioleate, and polyoxyethylene sorbitan monolaurate.

As explained above, and in the following Examples and Comparative Examples, the surface oil composition according to the present invention has lubricity (dynamic friction coefficient measurement test), rust prevention (wet box test, packaging storage test),
As a result of conducting various tests on paintability (paint film adhesion test, eye hole property test) and degreasing property (electrolytic degreasing test), it was found that the surface oil composition of the present invention was applied better than conventional products in terms of both properties. It was confirmed that the results obtained were superior to those of the conventional method (see Tables I to Table ■).

Hereinafter, preferred examples of the surface oil composition of the present invention will be specifically explained while comparing with comparative examples.

Example I (Acetyl) IJ Butyl citric acid was added with a large amount of oleic acid monoglyceride, heated to 50°C, and mixed uniformly with stirring. A surface oil composition was prepared by adding 1 g/g of the surface oil composition to IJ butyl citric acid, and mixing it uniformly with stirring.
Tin plated with tin of m2, polished using a tin layer melter, and chemically treated with cathode treatment in a sodium dichromate solution was coated with 4η/pan2 using an electrostatic oil applicator.

Example ■ A surface oil composition prepared by adding a large amount of lauric acid monoglyceride to acetyl tributyl citric acid, heating it to 50°C, and mixing it uniformly with stirring was placed in a tin plate similar to that obtained in Example I. Oil was applied at a rate of 4"j/rn' using an electrostatic oil application device.

Example ■ A surface oil composition prepared by adding a large amount of sorbitan monooleate to acetyl tributyl citric acid, heating it to 50°C, and mixing it uniformly with stirring was applied to a tin plate similar to that obtained in Example I. Oil was applied at a rate of 4 .mu./m2 using an electrostatic oil applicator.

Example 2 The surface oil composition, tin plate, and oil application method were the same as in Example I, and the amount of oil applied was 8"17 m2.

Example V The surface oil composition, tin plate, and oil application method were the same as in Example (2), and the amount of oil applied was 8 ■/m2.

Example (2) The surface oil composition, tin plate, and oil application method were the same as in Example (2), and the amount of oil applied was 8η/m2.

Comparative Example I Acetyltributylcitric acid was applied to the same tin plate as in Example I at a rate of 4 Q /rn2 using an electrostatic oil applicator.

Comparative Example ■ DO8 was applied to the same tinplate as in Example I using an electrostatic oil applicator in an amount of 4"9/m2.

Comparative example ■ Using the same tin plate, surface oil, and oiling method as in Comparative example 1, 8mg/
Anointing of m2 was performed.

Comparative example ■ 8"i' using the same tin plate, surface oil, and oiling method as in Comparative example ■
/m2 of oil was applied.

In order to examine the lubricity of the tinplate surface of the above Examples 1 to 2 and Comparative Examples I to 2, the dynamic friction coefficients of the samples were measured using a dynamic friction coefficient measuring machine immediately after manufacture and after storage for 6 months.

The results are shown in Table I below.

As is clear from the measurement results of the coefficient of dynamic friction in Table 2, it is easy to see that the surface oil of the present invention has excellent lubricating properties and its degree of deterioration is small.

Table I Results of Dynamic Friction Coefficient Measurement Next, in order to examine the rust prevention properties, Examples I to ■ and Comparative Examples I to ■ were tested in accordance with the JIS-Z-023 wet box test method and package storage test method. I did it.

Judgment was made in accordance with the standard method for rust generation and transformation of JIS-Z-0236.

The results are shown in the table below. It can be seen from the surface test results that the surface oil composition of the present invention proves to be overall superior to previous ones.

Next, in order to examine the paintability, for Examples I to ■ and Comparative Examples I to ■, the ones immediately after production and 100 tin plates each were stacked on a skid, and the outer surface was wrapped with anti-rust paper. Three similar skids were stacked on top of each other, and after three months, a sample was taken from the center and a coating test was conducted.

For the paint film adhesion test, an epoxy phenol-based paint was applied to a coating amount of 45 ± 5 J721//m2, and a stripping test was performed on the product, which was baked and dried at 210°C for 10 minutes. went.

Peeling was evaluated based on the rate of peeling in 100 rows.

The results are shown in the following table (■). It can be seen from Table 1 that the surface oil composition of the present invention has very good coating film adhesion.

Eyehole property was determined by applying the same paint as in the paint film adhesion test to a coating amount of 20±2"?/dm2 and baking drying for 10 minutes at a temperature of 210℃. The occurrence of holes was visually observed.

The evaluation was based on the number of eyeholes generated on a 5-grade scale from A to E.

A: no eyeholes, B: 5 to 10 eyeholes, C: 20 to 50 eyeholes, D: hundreds of eyeholes on the entire surface, E: eyeholes on the entire surface, and This shows dozens of locally dense eyeholes.

The results are shown in Table 3 below.

As is clear from this table, the surface oil composition of the present invention has extremely few eyeholes, and together with the aforementioned coating film adhesion, the surface oil composition of the present invention has very good paintability. has been proven to be excellent.

In conducting the degreasing test, a tinplate original plate was used because it has poor water wettability and it is difficult to evaluate the degreasing property.

The original tin plate was electrolytically degreased for 30 seconds in a 5φ orthosilicate sodium solution heated to 50°C with a current density change of I A/d m', and after confirming that it was completely wetted with water, it was washed with water and then dried with hot air. , Examples 1 to 2 and Comparative Examples V to 2 were tested.

Example ■ The surface oil composition used in Example I was applied to a tinplate original plate degreased as described above using an experimental electrostatic oil applicator for 10rIII.
i/ Door 2 was anointed.

Example ■ The surface oil composition used for the actual measurement was applied to the tinplate original plate degreased as described above using an experimental electrostatic oil applicator at a concentration of 10η/view2.
performed the anointing of oil.

Example ■ The surface oil composition used in Example ■ was applied to a tin plate that had been degreased as described above at a rate of 10η/m using an experimental electrostatic oil applicator.
2 anointing was performed.

Example
/m2 of oil was applied.

Example M The surface oil composition used in Example ① was applied to a tinplate base plate degreased as described above using an experimental electrostatic oil applicator at 20η/m.
2 anointing was performed.

Example ■ The surface oil composition used in Example ■ was applied to a tin plate that had been degreased as described above using an experimental electrostatic oil applicator at a rate of 20 l/m.
2 anointing was performed.

Comparative Example V The same surface oil as in Comparative Example I was applied to a tin plate that had been degreased as described above using an experimental oil application device at a rate of 10 mP/m2.

Comparative Example (2) A tin plate that had been degreased as described above was coated with the same surface oil as in Comparative Example (1) at a rate of 1 om'i/m2 using an experimental electrostatic oil coating device.

Comparative Example (2) The same surface oil as in Comparative Example I was applied to a tin plate that had been degreased as described above using an experimental electrostatic oil applicator at a rate of 20 cm/TrL2.

Comparative Example (2) A tin plate that had been degreased as described above was coated with the same surface oil as in Comparative Example (2) at 20''9/m2 using an experimental electrostatic oil applicator.

A degreasing property test was conducted on the above Examples ① to ③ and Comparative Examples Ⅲ to ③.

In the test, the above-mentioned oil-coated steel plate was electrolytically degreased at 30°C in a di-orthosilicate sodium solution at a current density of 0.2A/dm2.
The water wettability was examined for 5 seconds, and the water wetness was judged as white Kasuri and evaluated.

The results are shown in the following table ■.

As is clear from Table 3, it can be easily seen that the surface oil composition according to the present invention has superior degreasing properties compared to conventional compositions.

Claims (1)

[Scope of Claims] 1 The following general formula [In the above formula, R1, R2+ R3 are hydrogen or alcohol residues having -'71 to 18 carbon atoms, and at least one of these is the alcohol residue described above; , and R4 is hydrogen or a carboxylic acid residue having 1 to 18 carbon atoms.] Glycerin fatty acid ester, propylene glycol monofatty acid ester, sorbitan fatty acid ester,
One or two selected from the group consisting of polyoxyethylene sorbitan fatty acid ester and triethanolamine
A surface oil composition for surface-treated steel sheets, which is made uniform by adding a total of 0.1 to 10% of more than one type of compound.