JPS6057514B2 - Rust inhibitor and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rust inhibitor with improved mineral oil compatibility and a process for making the same.

In general, metal surfaces suffer from pitting, groove corrosion, and rust due to corrosive liquids, corrosive gases, moisture in the air, and the like.

Various rust preventive agents have been proposed and used as rust preventive agents for iron, iron alloys, and rust. These rust inhibitors are broadly classified into inorganic rust inhibitors and organic rust inhibitors. Rust inhibitors include various amines, carboxylates, mercaptans, and alcohols. However, there are almost no rust preventives that are effective in all ways in which metals are used, and most of them are limited in the ways in which they can be used, and there are many problems in their use.

Although inorganic rust inhibitors have excellent rust prevention ability,
Their use is gradually being regulated due to their toxicity, including carcinogenicity, and water pollution. On the other hand, organic rust inhibitors have been considered to be inferior to inorganic rust inhibitors in terms of their rust prevention effects;
In recent years, various types of rust preventive agents with excellent performance have been developed, and from the viewpoint of safety, it is expected that their use will increase in frequency in the future.

Among them, lanolin derivatives, especially pentaerythritol ester, glycerin ester, sorbitan ester, and metallurgy, have excellent rust prevention and lubricity. These are known for example from: Pentaerythritol ester (JP-A-48-102767) Glycerin ester (JP-A-48-102767, JP-A-50-1
8502) Zorbitan ester (JP-A-1850-1850)
2) Synchhexylamine salt (Special Publication No. 44-1588
7) Metallic Soap (Japanese Patent Publication No. 42-19702) These lanolin derivatives have superior rust prevention effects compared to oxidized paraffin-based rust preventives and petroleum (synthetic) sulfonate-based rust preventives, which have traditionally been used as rust preventive agents. In particular, calcium soap, which is one of the lanolin metal soaps, has superior rust-preventing ability than conventional rust-preventing agents.

However, none of these lanolin derivatives has sufficient compatibility with mineral oil, and even esters with relatively good compatibility, such as lanolin fatty acid pentaerythritol diester and lanolin fatty acid glycerol triester, are completely dissolved when dissolved by heating. However, if it is left at room temperature for a long time or cooled to near 0°C, a small amount of insoluble matter will precipitate.

In addition, in the case of calcium soap, the solution becomes cloudy and some precipitates are formed even at room temperature.

For this reason, although these lanolin derivatives have excellent rust preventive properties and lubricity, their use as rust preventive oil additives or lubricant oil additives is severely limited. Therefore, in order to improve solubility, solubilizers are used together,
Attempts have been made to adjust the equivalent ratio of calcium hydroxide during calcium soap formation, but this is still not sufficient. In the present invention, instead of using conventional wool grease or lanolin fatty acid obtained by oxidizing lanolin as a rust preventive agent by directly neutralizing it and turning it into calcium soap, the lanolin fatty acid is heated under reduced pressure and By lactidizing or lactonizing the hydroxy fatty acid component contained in the soap and then reacting it with calcium hydroxide to form calcium soap, the solubility in mineral oils is significantly improved, and the antirust effect is even enhanced. It is based on new knowledge.

As is well known, lanolin fatty acid is obtained by saponifying wool grease or lanolin, and its composition is approximately as follows.

゛(V no 1U
The acid value and saponification value of early JV and V are usually 130 to 160 and 16, respectively.
There are 0 to 180.

The reason why conventional lanolin derivative-based rust inhibitors do not have sufficient solubility in mineral oil is that lanolin fatty acids contain a large amount of hydroxy fatty acids, as can be seen from the above composition, and the hydroxyl groups of these hydroxy fatty acids remain even after calcium soap formation. However, this is thought to be because its hydrophilicity inhibits solubility in mineral oil and also partially reduces rust prevention.

Furthermore, the presence of hydroxyl groups is considered to be one of the causes of oil burn. Therefore, we conducted an experiment thinking that it would be possible to improve solubility and rust prevention by converting the hydroxy fatty acid into clatide and/or lactonization to eliminate the hydroxyl group function, and then converting it into calcium soap. was able to achieve this.

It was also possible to reduce oil scorching caused by anti-rust oil containing calcium soap. Therefore, the present invention is characterized by containing as an active ingredient a calcium salt of a low acid value lanolin fatty acid with an acid value of 110 or less, which is present by lactidation and/or lactonization of the hydroxy fatty acid contained in the lanolin fatty acid. Regarding rust preventives.

Further, the rust preventive agent according to the present invention includes a step of heating a lanolin fatty acid under reduced pressure to lactide and/or lactonize the hydroxy fatty acid to obtain a low acid value lanolin fatty acid having an acid value of 110 or less, and It is produced by a method comprising mixing and melting lanolin fatty acid with a solubilizer, neutralizing it with calcium hydroxide, and, if necessary, dissolving the obtained reaction product in mineral oil. When hydroxy fatty acids contained in lanolin fatty acids are heated under reduced pressure,
It is known that two molecules of water are dehydrated from these two molecules to form a lactone, or that a lactone is formed by dehydration within the molecule, and the reaction conditions for this are also known.

Although the present invention does not include the reaction conditions for lactide and/or lactonization as a part of its composition, it does not require that the resulting low acid value lanolin fatty acid have an acid value of 110 or less,
Preferably, L is required to be less than 10 liters.

The reason is that the acid value above the above value does not sufficiently clatify and/or lactonize hydroxy fatty acids.
This is because the required solubility is not reached because the hydroxyl group remains. This low-acid-value lanolin fatty acid is melted by adding a solubilizing agent that does not inhibit rust prevention, such as lanolin, wool grease, petroleum (synthetic) sulfonate, or oxidized paraffin, to obtain a solution that matches the acid value of the low-acid-value lanolin fatty acid. Add calcium hydroxide and heat and stir at about 14,075 to 70 degrees for 30 to 6 minutes.

The appropriate amount of calcium hydroxide to be used is 0.9 to 1.2 equivalents relative to the acid value of the low acid value lanolin fatty acid.
Also, solubilizers such as lanolin, wool grease, petroleum (synthetic) sulfonates, or oxidized paraffin can be used as lucium. The ratio of soap/solubilizer is 4:1 to 1:3, preferably 3:
Amounts such that the ratio is 1 to 1:1 are preferred. After the reaction, it may be cooled and shipped as is. However, if you are dissolving it in mineral oil and shipping it, add mineral oil, such as spindle oil or turbine oil, while it is still hot to lower the viscosity and remove any unreacted water. Remove calcium hydroxide by decanting or by mouth-passing.

Furthermore, instead of mixing and melting the solubilizer and then reacting with calcium hydroxide, it is also possible to first melt the low acid value lanolin fatty acid alone, react with calcium hydroxide, and then add the solubilizer.

However, although the reason is not clear, the latter has poorer transparency at low temperatures than the former. The rust preventive agent of the present invention obtained in this way has excellent solubility in mineral oil and rust preventive ability compared to conventional products made into calcium soap without undergoing lactidization and/or lactonization treatment. It has the advantage of less oil burn.

Example 1 A lanolin fatty acid with an acid value of 155.4 and a saponification value of 169.5 was heat-treated under reduced pressure to obtain a low acid value fatty acid with an acid value of 101.2.

1.034 kg of industrial lanolin (acid value 28) was added to 1k9 of this low acid value fatty acid, and after heating and melting, 65 g of calcium hydroxide (0.96 equivalent to the fatty acid) was gradually added, and the mixture was heated at 150 to 160°C. The mixture was heated and stirred for 1 hour to obtain the rust preventive agent of the present invention. Example 2 A lanolin fatty acid with an acid value of 149.6 and a saponification value of 167.7 was heat-treated under reduced pressure to obtain a low acid value fatty acid with an acid value of 104.9.

1 kg of this low acid value fatty acid and wool grease (acid value 4.2
) After heating and melting 345 g of calcium hydroxide, 72 g of calcium hydroxide (1
．． 04 equivalent) was gradually added and reacted at 150-160°C for 1 hour. After the reaction, the mixture was cooled to 110°C, mixed with 690 g of 60-spindle oil, and stirred at 100°C for 30 minutes.

Next, unreacted calcium was removed by a decanting method to obtain the rust preventive agent of the present invention. Example 3 A lanolin fatty acid with an acid value of 155.4 and a saponification value of 169.5 was heat-treated under reduced pressure to obtain a low acid value fatty acid with an acid value of 108.5.

After heating and melting 1k9 of this low acid value fatty acid and 519g of calcium petroleum sulfonate (acid value 3.8), 75g of calcium hydroxide (1.05 equivalent) was gradually added to the
React in three batches at ℃. After reaction 90-turbine oil 1.56k
Add 9 and stir at 140°C. Next, unreacted calcium hydroxide was removed by filtration to obtain the rust preventive agent of the present invention. Comparative Example 1 Lanolin fatty acid 1k9 with acid value 155.4 and saponification value 169.5 and industrial lanolin (acid value 2.8) 1.053k9
After heating and melting, add calcium hydroxide? (4). 96
equivalent amount) was gradually added, and the mixture was heated and stirred at 150 to 160°C for 1 hour to obtain a rust preventive.

Comparative Example 2 Lanolin fatty acid 1k9 with acid value 155.4 and saponification value 169.5 and industrial lanolin (acid value 2.8) 1.053k9
After heating and melting, add 65g of calcium hydroxide (0.6
3 equivalents) were gradually added and stirred while heating at 150 to 1600 C for 1 hour to obtain a rust preventive.

Comparative Example 3 A lanolin fatty acid with an acid value of 149.6 and a saponite value of 167.7 was heat-treated under reduced pressure to obtain a fatty acid with an acid value of 115.2.

1 kg of this fatty acid and industrial wool grease (acid value 4.2
) After heating and melting 346 g of calcium hydroxide, 80 g of calcium hydroxide (1
．． 05 equivalent) was gradually added and reacted at 150 to 160°C for 1 hour. After the reaction, the mixture was cooled to 110°C, 693g of 60-spindle oil was added, and the mixture was stirred at 100°C.

Next, unreacted calcium was removed by a decanting method to obtain a rust preventive. The performance of the rust preventives obtained in Examples and Comparative Examples was tested as follows.

1 Rust prevention 1-1 Humid rust prevention test (JIS-Z-0236) A mild steel plate test piece (SPCC-Bl. 6 x 30
x8i) is immersed and then pulled up.

After being left at the temperature for one day, the temperature was increased to 4 according to JIS-Z-0236.
The rusted area was measured over time under conditions of 9±1° C. and a humidity of 95% or higher.

Evaluation ◎: No rusting 0: 1-2 points Rusting Δ: Rusting on less than 5% surface area ×: Rusting on more than 5% surface area 1-2 Salt spray test Rust preventive at 60-spindle oil 3% concentration Melted and pre-treated mild steel plate test piece (SPCC-Bl.6×30
x 80 m) at room temperature in the form of a mist of 5% saline, and after 3 hours, 5% saline was sprayed again, and the rusted area was measured over time.

Evaluation: ◎: No rusting 0: 1 to 2 points Rusting Δ: Rusting at less than 5% surface area ×: Rusting at 5% or more surface area 2 Dissolve soluble rust preventive agent in various mineral oils, 2@ at 0℃ After a while, solubility was observed.

Claims (1)

[Claims] 1. Contains as an active ingredient a calcium salt of a low acid value lanolin fatty acid with an acid value of 110 or less, which is present by lactidation and/or lactonization of the hydroxyl fatty acid contained in the lanolin fatty acid. Rust preventive agent. 2 A step of heating lanolin fatty acids under reduced pressure to lactide and/or lactonize the hydroxy fatty acids thereof to obtain a low acid value lanolin fatty acid with an acid value of 110 or less, and mixing and melting the low acid value lanolin fatty acid with a solubilizer. A method for producing a rust preventive agent comprising the steps of post-neutralizing with calcium hydroxide and, if necessary, dissolving the obtained reaction product in mineral oil.