JPS5813698A - Steel plate treated with lubricant of high intermediate anticorrosive properties - Google Patents

Abstract

PURPOSE:A steel plate that is coated with a specific amount of a composition consisting of a polyhydric alcohol fatty acid ester, a barium salt of petroleum oxide and a barium sulfonate of aromatic hydrocarbon at a specific ratio to form a lubricating layer of high intermediate anticorrosive properties. CONSTITUTION:A composition consisting of (A) 50-95wt% of a polyhydric alcohol fatty acid ester of 50-300 hydroxyl value and 5-50wt% of a mixture of a barium salt of petroleum oxide and a barium sulfonate of aromatic hydrocarbon is coated on a steel plate after pressed by 0.1-10g/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention performs press forming without using a lubricant such as press oil, and then without applying rust preventive oil to maintain intermediate rust preventive power. The object of the present invention is to provide a lubricated steel plate with sufficient rust prevention ability and excellent intermediate rust prevention properties.

Conventional lubricated steel sheets, for example, when used as materials for automobiles, are press-formed, assembled, degreased, treated with zinc phosphate, and then painted. If it cannot be easily removed with a weak alkaline degreaser during the degreasing process, it will not be damaged, so it has a weak anti-corrosion ability. Therefore, if the press is to be stored for a long time after being assembled, a rust preventive oil is applied after the press to ensure intermediate rust preventive power.

As mentioned above, the present invention does not require intermediate rust prevention measures.
It has sufficient intermediate rust prevention power even if it is stored for a long time after press assembly. That is, the gist of the present invention is to prepare a mixture of polyhydric alcohol fatty acid ester' (i-50 to 95% by weight) having a hydroxyl value of 50 to 300, a petroleum oxide Ba salt and an aromatic hydrocarbon sulfonic acid Ba salt to a mixture of 5 to 50% by weight.
Composition consisting of % by weight 'io, 1-10 g/rr? This is a lubricated steel sheet with excellent intermediate rust prevention properties.

Next, details of the present invention will be described. The polyhydric alcohol fatty acid ester which is the main component of the coating composition of the present invention includes pentaerythritol, sorbitol, glycerin, glycol and the like. The other fatty acid is caprylic acid.

Capric acid, lauric acid, myristic acid, /? Lumitic acid, stearic acid, oleic acid, linoleic acid.

Examples include lylinic acid, coconut oil fatty acid, palm oil fatty acid, beef tallow fatty acid, and lanolin fatty acid.Although the hydroxyl value of the polyhydric alcohol fatty acid ester is limited to 50 to 300, the present inventors have conducted extensive studies. It was found that the above-mentioned polyhydric alcohol fatty acid ester having a hydroxyl value within this range is excellent in terms of anti-corrosion ability.That is, as shown in Fig. 1, coconut oil fatty acid pentaerythritol ester was applied to a cold-rolled steel plate. Cyclic corrosion test (wet, 50℃)
...2 hours, drying at 60℃...2 hours, total 4 hours 1
The results of measuring the area ratio of rust after conducting a 60-cycle test are shown below. As shown in the figure, the antirust ability is good within the range of hydroxyl value from 50 to 306. The control steel sheets for coating were pickled steel sheets after hot rolling, cold rolled steel sheets, and various surface-treated steel sheets.
・::, JJ, ・Next, regarding the blending amount, if the polyhydric alcohol fatty acid ester is less than 50 parts by weight, the press formability will be poor, and if it exceeds 95 parts by weight, the desired rust prevention power will be deteriorated, as will be described later. I can't get it. Therefore, the range needs to be 50 to 95 parts by weight. Petroleum oxides and AA! oX2
213, has been commercialized under the name of Na-8ul BSN and is well known.

The present inventors conducted extensive research on the combinations of fatty acid pentaerythritol esters having a hydroxyl value of 30 to 500 and types of antirust additives, and found that the combination with petroleum oxide Ba salts and aromatic hydrocarbon sulfonic acid Ba salts It has been found that intermediate rust prevention properties can be significantly improved without impairing press lubricity. If the amount of the rust preventive additive exceeds 50%, the press lubricity will be reduced, and if it is less than 50%, the rust preventive power will be insufficient. Therefore, it is necessary that the range is from 5 to 50 inches. Petroleum oxide Ba salts are Ba salts of polymeric organic acids, oxyacid lactones, tools, etc., obtained by oxidizing petroleum-based hydrocarbons.

Next, we will discuss how to apply it to steel plates. Coating method C: Any method such as roll coater, spray, curtain flow, etc. may be used. A possible method for controlling the film thickness is to dilute the composition of the present invention with an organic solvent.

If the coating amount is less than 0.1g/7rt, the press lubricity and rust prevention ability will be insufficient, so 6D or 10g/? If it exceeds FI'', no improvement in press lubricity or antirust ability can be expected and it is wasteful. Therefore, it is necessary that the range is from 0.1 to 109/d.

EXAMPLE Various lubricating compositions were applied to a 0.8 mm thick aluminium-killed cold-rolled steel plate after temper rolling, and the performance thereof is shown in Table 1.

In the table, AI, A2, A3, A4 are comparative examples, A5゜A
6, A7, Ya8, A9, and Al2O are examples of the present invention. Comparative Example Flat No. 1 has a hydroxyl value of 30 or less and lacks the rust preventive additive, A2 lacks the rust preventive additive, and A3 has the rust preventive additive of the present invention. Outside A4 has a hydroxyl value of 30 or less. In contrast, A 4 , 5 , 6 , and 7 produced by the method of the present invention have greatly improved anticorrosion ability without impairing press lubricity.

The limit drawing ratio in the table is determined as follows.

Punch diameter 50mm Ω Gooey diameter 52.4mm 2 Punch shoulder RIOR Die shoulder R5R Drawing speed 200111/Im Under the above deep drawing conditions, pressing was performed with various blank diameters, and the blank diameter just before breakage ( =Bd).

Limit drawing ratio = Bd150 Next, for rust prevention, one cycle was 2 hours at 50°C9 in an atmosphere with a relative humidity of 95% or more, and 2 hours drying at 60°C.
The rusted area ratio was measured at the 30th cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the relationship between the hydroxyl value and antirust ability of polyhydric alcohol fatty acid esters.

Claims (1)

[Claims] A composition consisting of 50 to 95% by weight of a polyhydric alcohol fatty acid ester having a hydroxyl value of 50 to 300 and 5 to 50% by weight of a mixture of Ba salt of petroleum oxide and Ba salt of sulfonic acid of an aromatic hydrocarbon is prepared at 0.0% by weight. 1~10F! /lr? Lubricated steel plate with excellent intermediate rust prevention properties.