US3915869A

US3915869A - Metal forming lubricant

Info

Publication number: US3915869A
Application number: US478820A
Authority: US
Inventors: Toru Katono; Yoshio Hachisu; Ryozi Saito; Kazushi Goto; Haruo Kubotera; Kenzi Araki
Original assignee: Nippon Kokan Ltd
Current assignee: JFE Engineering Corp
Priority date: 1967-11-22
Filing date: 1974-06-12
Publication date: 1975-10-28
Anticipated expiration: 1992-10-28
Also published as: FR1601458A; GB1261358A; BE724294A; CA958695A; DE1810412A1; NL6816683A

Abstract

a. A water-soluble surface-active agent selected from semihydrogenated beef tallow potash soap, oleic acid potash soap, oleic acid soda soap, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate, sorbitan trioleate, lauryl amino acetate, and stearyl amino acetate; B. A water-soluble synthetic resin which is a combination of an oil-modified alkyd resin with a phenol or cresol-novolac-type resin.

Description

United States Patent Katono et a1.

METAL FORMING LUBRICANT Inventors: Toru Katono; Yoshio Hachisu, both of Yokohama; Ryozi Saito, Tokyo; Kazushi Goto, Hiroshima; Haruo Kubotera; Kenzi Araki, both of Yokohama, all of Japan Assignee: Nippon Kokan Kabushiki Kaisha,

Ootemachi, Japan Filed: June 12, 1974 Appl. No.: 478,820

I Related U.S. Application Data Continuation of Ser. No. 132,151, April 7, 1971, abandoned, which is a continuation-in-part of Ser. No. 777,742, Nov. 21, 1968, abandoned.

Foreign Application Priority Data Nov. 22, 1967 Japan 42-7462 Oct. 23, 1968 Japan 43-76804 Nov. 13, 1968 Japan 43-82519 U.S. Cl. 252/12; 252/34.7; 252/41;

252/49.5 Int. Cl..... Cl0m 7/30; C10m 7/20; ClOm 7/16 Field of Search 252/12, 12.2, 12.4, 12.6,

[ Oct. 28, 1975 Primary Examiner--Delbert E. Gantz Assistant Examiner1. Vaughn Attorney, Agent, or FirmMichae1 S. Striker [5 7] ABSTRACT a. A water-soluble surface-active agent selected from semi-hydrogenated beef tallow potash soap, oleic acid potash soap, o1eic acid soda soap, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate, sorbitan trioleate, lauryl amino acetate, and stearyl amino acetate;

b. A water-soluble synthetic resin which is a combination of an oil-modified alkyd resin with a phenol or cresol-novolac-type resin.

1 Claim, 5 Drawing Figures US. Patent T Oct. 28, 1975 Sheet 1 of3 3,915,869

ii; i; f

OUTER DIAMETER AFTER BREAKAGE 0 lo 20 3O 4O 50 WATER SOLUBLE SYNTHETIC RESIN (HlTANOL 6080 N) o- WATER SOLUBLE SURFACE ACTIVE AGENT 50 (DICE-LEX SOAP) TEST SHEET: sPc-s 480mm (BANKED DIAMETER) x 0.8mm (THICKNESS) LUBRICANT: DIE SIDE LUBRICATING STAMPING couomou: PUNCH DIAMETER ZOOmrnfl,

uucume SPEED lBm/min RATIO OF 23 LIMIT DRAWING 0 5 IO I5 20 COATING AMOUNT (Q/m US. Patent Oct. 28, 1975 Sheet 2 of 3 OUTER DIAMETER AFTER BREAKAGE STAMPING OIL B (SUPERIOR) STAMPING OIL A SOLD DRY LUBRICANT FILM B SOLD DRY LUBRICANT FILM A THE INVENTED ONE TEST SHEET: SPC-3 480mmflBLANKED DIAMETER) X 0.8 mm (THICKNESS) LUBRICANT: DIE SIDE LUBRICATING STAMPING CONDITION: PUNCH DIAMETER 200 mm 5 PUNCHING SPEED IBm/min IT I 5 THE RESIDUAL MOISTURE (96) U.S. Patent Oct. 28, 1975 Sheet 3 f 3 80 Drymg condmon: Room Temperature C Humidity vThe Invented One 60- Residuol moisture (7Q) min. min. min. min. hr.

METAL FORMING LUBRICANT This is a continuation of application Ser. No. 132,151, filed on Apr. 7, 1971, which application Ser. No. 132, 151 in turn is a continuation-in-part of Serial No. 777,742 filed on Nov. 21, 1968, both now abandoned, by the same inventors in respect of DRY LU- BRICANT AND METHOD OF MANUFACTURING METALS COATED THEREWITH.

BACKGROUND OF THE I INVENTION The invention relates to a lubricant for coating steel, particularly steel sheets, to prepare the steel for forming operations, particularly deep-drawing.

Deep-drawing of steel sheets is particularly used for making automobile parts, electrical home appliance parts and metal pipes. It is also used on steel for drawing to form metal wires, particularly electric wires.

The lubricant for these purposes must form a film on the metal and must meet a number of requirements.

a. It must have high power lubricating properties.

b. It must be adapted to be readily removed from the metal after forming.

c. It must have good anti-corrosion properties.

d. It must be useful for dry forming of the steel parts.

e. It must have a high resistance against sticking to the different parts involved.

f. It must be well adapted for welding, including spot welding.

g. It must be non-toxic, non-odorous, and noninflammable.

Present day lubricants meet some of these objectives, but cannot meet them all.

Particularly steel sheets coated with conventional lubricants are hard to dry and require extensive periods for the drying operation. They often are not useful for high-speed stampor punch-forming of metals, and if used for these purposes require undue apparatus and processes to be employed.

The present invention, accordingly, has the object to provide for a lubricant for these purposes which will meet all of these requirements and still be easily applicable to the steel, in particular to steel sheets for deep drawing operations.

SUMMARY OF THE INVENTION These objects are met by a lubricant which comprises a mixture of a surface-active agent and a water-soluble synthetic resin in relative amounts between 20 and 80 parts of surface-active agent and between 80 and 20 parts of water-soluble resin. Preferably, the lubricant includes 1 to 50 parts of a water-soluble or water-emulsifiable lubricating oil for each 100 parts of the mixture of surface-active agent and water-soluble resin.

The steel is coated with the lubricant after preheating to between 80 and 100C and subsequent drying so as to reduce its moisture content to below 10% by weight. The coating is thereafter applied to the steel.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and is method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING 5 the lubricant of the invention and the outer diameter of a test piece after breakage in flat bottom deep-drawing;

FIG. 2 is a comparative diagram showing on one hand a conventional lubricant, and on the other hand the lubricant of the present invention;

FIG. 3 is a similar comparative diagram showing the drying speed of the lubricant of the invention compared with the drying speed of soap;

FIG. 4 is a diagram illustrating the relationship between the amount of lubricant coated on the steel and the limit of drawing ratio (LDR)(maximum drawing ratio);

FIG. 5 is a diagram illustrating the relationship bewteen the residual moisture on the steel and the limit of drawing ratio (LDR) in a steel coated with the lubricant of the invention.

DETAILED DESCRIPTION OF THE INVENTION AND OF PREFERRED EMBODIMENTS As will be further explained below, the lubricant of the invention is suitable for stamping speeds in excess of 20 m/min. Conventional dry lubricants used for this purpose fail at speeds exceeding 10 m/min. They'are only good for rates up to mm/min. Actually, the properties of the lubricant of the invention do improve with higher stamping speeds. The lubricant of the invention, as will be further explained, is suitable for stamping speeds even in excess of 20 m/min.

A wide range of water-soluble surface-active agents may be used in the lubricants of the invention. Reference is made to the comparative tests with different lubricants illustrated in Table 6 below. A broad list of suitable surface-active agents includes the following:

1. Anionic water-soluble surface-active agents: aliphatic acid salts in carboxylic acid soap of the formula RCOONa(K,NI-I wherein R: C C Examples are alkali metal soaps of saturated or unsaturated aliphatic acids, for example oleic acid soda soap, oleic acid potash soap, castor oil soap, beef tallow soda soap, soyabean oil soap.

2. Cationic agents:

aliphatic amine salts:

wherein X is an acid, and R R and R are H or alkyl from C to C An example is acetamine (lauryl amine acetate, C H NH -CH COOH, [Acetamine 24 made by Kao Soap Company] or stearyl amine acetate [Acetamine 86 made by the same company]).

3. Nonionic agents:

1. polyoxyethylene alkyl ethers RO(C I-l O),,I-I, for example polyoxyethylene-oleyl ether (Emulgen 430 of the Kao Soap Company [C H O(C 4 2. polyoxyethylene sorbitan alkylesters (for example Emasol 4130 of the same company, a polyoxyethylene sorbitan monooleate) 3. sorbitan alkyl esters, for example Emazol 430, which is sorbitan trioleate (aromatic group), made by the same company.

Preferred anionic water-soluble surface-active agents are saturated aliphatic acid salts having 8 to 22 carbon atoms. An example is a mixture of capric acid (C H 'COOH), lauric acid (C l-I COOH), myristic acid (C, H -,-COOH), palmitic acid (C H COOH), stearic acid (C H COOH), and a mixture of unsaturated aliphatic acids having 8 to 22 carbon atoms, oleic acid [CH (CH CH=CH(CH COOH], linolic acid [CH (CH CH=CHCH Cl-l=Cl-l(Cl-l COOl-l], linolenic acid [CH (CH )Cl-l=Cl- (Cl-I )Cl-l=CH(Cl-l )CH=CH(CH COOH], and ricinoleic acid [Cl-l (Cl-l Cl-l(OH)CH CH=CH(CH COOH].

The water-soluble synthetic resins may be the following:

1. Resins which generally come under the term phenolic resins such as cresol-modified novolac-type resms;

2. alkyd resins such as linseed oil, coconut oil, or castor oil modified alkyd resins;

3. phenolic-alkyd resin combinations such as linseed oil-modified alkyd resins which are combined (further modified) with a cresol or phenol novolac resin.

The resins must be water-soluble and should also be soluble in combination with the surface-active agent and the water-soluble oil.

As has been indicated, preferably a third component is included in the combination. This is a water-soluble or water-emulsifiable oil, by which term is understood an oil which is dispersed in water by emulsification.

The amounts of the three components are as follows: The mixture between surface-active agent and watersoluble synthetic resin should comprise to 80 parts of the surface active agent and 80 to 20 parts of the water-soluble resin.

To 100 parts of this mixture, if desired, there may then be added 1 to 50 parts of the water-soluble oil. All parts to be understood by weight.

If the water-soluble surface-active agent is present in excess of 80%, and a corresponding reduction of the water-soluble resin is effected, the results regarding adhesion to the steel sheet are generally poor. Conversely, if the water-soluble resin exceeds 80 parts, and the surface-active agent is present in correspondingly lower amounts, the resultant mixture becomes too sticky and the resistance to sticking and blocking is decreased.

If the amount of the water-soluble oil is below 1 part, the oil would have no appreciable effect. On the other hand, if the oil exceeds 50 parts of the mixture of the mixture of surface-active agent and resin, it will be difficult to obtain uniformity of the composition because of coagulation.

The optimum ratios of amounts are about as follows:

water-soluble surface-active agent 30-70 parts water-soluble synthetic resin 7030 parts water-soluble oil 5-40 parts The lubricant is applied in an aqueous solution of a water content of between 5 and 60% by weight. Again, if the amount of water is too small, the solution becomes sticky and no uniform coating will be obtained. On the other hand, if too much water is added, the dry- 4 ing is too slow and a film of suitable thickness is hard to obtain.

In general, inclusion of the oil as a third component is definitely preferred because of the increased lubrication and the resulting improvement of the forming and drawing operation.

In applying the lubricant of the invention at a ratio, for instance, of 10 g/m it was found that if the moisture content was to be reduced below 5%, as is desirable in some cases, it was necessary to apply a hot-air blast of a temperature of 150C at a speed of application of 5 m/sec for a period of 35 seconds in case of a sheet of 0.8 mm thickness. If the sheet had a thickness of 3.2 mm, the application of the hot-air blast was for 60 seconds. Accordingly, if the conveyor moved, for example, at a speed of 60 m/min, a drying zone of more than 60 m in length would be required on which length no guiding roll should be provided. This obviously would result in difficulties with the apparatus. Besides, more difficulties would occur with respect to the tracking of the sheet. The cost of equipment, in any case, would be excessively high.

To eliminate these objections it was found that the temperature of the hot-air blast should be increased. With a temperature of the hot-air blast above 200C, however, bubbles were generated on the lubricantcoated surface. This reduced the commercial grade of the coated steel, and also had an adverse physcial and chemical effect on the properties of the lubricating film. All this applies for sheets as well as for metal tubing and wire.

The lubricant of the present invention is slow-drying. FIG. 3 illustrates a comparison of the lubricant of the invention with a water-soluble surface-active agent used alone in the form of a soap. As can be seen, the lubricant of the invention retains approximately 40% of the original moisture after a period of 90 minutes. Thereafter, and during a period of about 16 hours, it still retains 35% of the original moisture. Soap alone retains only 15% after 30 minutes and approximately 2% after a period of 60 minutes.

Preferably the coating of the present invention is applied in an amount of 3 to 20 g/m Most preferably the amount is between 10 and 20 g/m The residual moisture is thus dried to an amount of less than 10% of the initial moisture, and preferably to an amount below 5%.

The reduction of the moisture is best obtained by rapid drying with a hot-air blast. The physical and chemical properties of the lubricant are thereby preserved at their maximum value while the moisture is reduced.

The coating is effected by subjecting the metal sheet, metal strip or wire to a preceding cleansing with a degreasing solution and then to a heat treatment at a temperature of -l00C. The preheating treatment may be effected by a high-pressure steam blast on the order of 2 to 15 kg/cm directed against the surface of the steel sheet or, alternatively, the sheet may be immersed in hot water at a temperature above C.

Table 1 illustrates the heating times required to heat a steel sheet up to C for various thicknesses and various methodsof applying heat.

TABLE 1 Time for heating steel sheet to 100C by different heating methods.

With the high-pressure steam heat, the necessary temperature increase can be obtained with a simple and inexpensive apparatus, provided that steam of sufficiently high pressure is used.

The immersion in hot water at a temperature of 100C requires somewhat longer times and the introduction into a furnace requires a rather long time. By infrared radium lamp, the time of application is rather excessive.

After completion of the cleansing and preheating step the lubricant is applied by coating. This may be done by air spray or by other methods such as rollers or immersion.

The viscosity of the lubricant should be such as to permit application within -45 seconds with a Ford Cup No. 4, depending on the amount of lubricant applied and the speed of the conveyor belt.

For application the lubricant should be at a temperature between room temperature (25C) and 50C, but it may also be applied at high temperatures up to 90C, depending on circumstances.

If the application is by immersion, the sheet may then be passed through squeeze rollers to adjust the amount of coating. If the application is by immersion at a temperature of about 90C, it is also possible to omit the entire preheating step. i

The coated sheet then is preferably dried by a hot-air blast.

Table 2 shows the drying time for coating a dry metal sheet with the lubricant of the invention at an amount of 10 g/m and a residual moisture content of 5%. The lubricant employed in these and other tests was that of Example 1, to be described below. i

TABLE 2 Relationship between drying conditions and drying time temp. of sheet The lubricant of the invention may be used on any kind of steel sheet or steel of other forms. However, a sheet steel of a thickness below 3.2 mm is preferred. Preferably, the coating of this type of sheet steel is effected at a conveyor line speed below 100 m/min. The optimum concentration of the aqueous solution applied 6 is between 25 and 60% by weight. Preferably, the amount applied of the lubricant is about 1 to 30 g/m on the dry sheet.

The hot blast for drying is preferably applied at a temperature between and 200C and a blast velocity of 2 to 20 m/sec. The residual moisture should in any case be below 10% and preferably be below 5%.

If the water-soluble synthetic resin used in the lubricant of the invention contains an amine group, a separate anti-corrosion agent may not be necessary. Otherwise, it is preferred to add about 0.05 to 5% of anti-corrosion agent, this amount being relative to the total amount of lubricant.

The following example will further illustrate the invention.

In these examples, as well as in the tables mentioned before, the following materials were employed:

The water-soluble resin in the above tables and in all examples, except Example 5, was a linseed oil-modified alkyd resin which was combined (further modified) with a cresol novolac resin. The particular commercial product is identified as Hitanol 6080N. This is a product of the Hitachi Company, Ltd. of Japan. In Example 5 a similar resin was used, except that the novolac-type resin was a phenol resin. This product is identified as Hitanol 311 of the same company.

The alkyd resin is the conventional reaction product of a polybasic acid and polyhydric alcohol. In the examples the polybasic acid was phthalic anhydride and the alcohol was glycerol.

Instead of the linseed oil modification a tung oil or castor oil modification could also be resorted to.

The water-soluble surface-active agent in all above tables and all examples was beef tallow soda soap. However, in Table 6, included in Example 4, comparisons are shown with other water soluble surface-active agents which show that similar results can be obtained with other surface-active materials.

Except where otherwise indicated, the beef tallow soda soap used in the above tables and the examples is the product commercially available under the tradename Dice-Lex and is a product of the Nippon Oil and Fat Company, Ltd. of Japan.

The water-soluble oil used in the above tables and in the examples, except as otherwise indicated, was a mineral base cutting oil which is incorporated in the water by emulsification. Its product identification is .115 K- 2241 WI. Table 3, which forms part of Example 1, shows the use of different types of water-soluble oils which, however, all come under the above general description of mineral oil base water-soluble or wateremulsifiable cutting oils. Where nothing else is indicated, the product employed was the product available under the tradename Griton l 14 from the Toho Chemical Industries Company, Ltd. of Japan.

EXAMPLE 1 18.6 parts of beef tallow soda soap as identified above, 18.6 parts of a water-soluble phenol-modified linseed-modified alkyd resin, and 6.9 of water-soluble oil were dissolved in 55.9 parts of water at a temperature of 60-80C. The water-soluble phenol alkyd resin had a pH of 9.0, a viscosity of 4.10 (poise) and a reddish-brown color. The water-soluble oil had a density of 0.93, a contents of non-volatiles of 93% and also a reddish-brown color.

The steel sheet was a sheet of 460 mm width (blank diameter) and 0.8 mm thickness. It was first cleansed and degreased. The lubricant was then applied and, after application, was subjected to drying for 6 minutes at a temperature of 120C. A well-dried film of high anti-stick properties was thus obtained. The sheet itself consisted of cold-rolled steel. The flat-bottom deepdrawing in the following test was effected with a die punch of 200 mm diameter SR and an opposed die of 203 mm diameter R. After carrying out the drawing operation on the coated steel sheet, the outer diameter, after breakage, was measured to determine the lubri- :ating property of the deep-drawing operation.

The test results appear from the following Table 3.

TABLE 3 EXAMPLE 2 Outer diameter Surfactant Resin after breakage Test No. Dice-Lex Hitanol 6080N" Water-soluble oil (mm) Remarks (all tests) 1 18.6 parts 18.6 parts 6.9 parts 406 coating Griton 113 condition: 2 6.9 parts Griton' 1 14" 405 coating 3 6.9 parts on die Griton 120" 409 side; 4 6.9 parts Griton 1000" 411 drying 5 6.9 parts Sorton C 409 condition: control: superior stamping oil B (one side) 440 120C, 6 min.

The so-called superior stamping oil B was a commerzial product used for control purposes, which had a vis- :osity of 660.

As can be seen from the test, where the die side of the :heet blank was lubricatedwith this latter oil, the outer iiameter after breakage was 440 mm.

As distinguished with the lubricant of the invention "Tests 1-5), the outer diameter after breakage was 105-41 1 mm. The lubricant in these cases was also apalied to the die side of the steel sheet.

With reference to the drawings, FIG. 1 shows that the inter diameter, after breakage, with a lubricant vherein the beef tallow soda soap and the water-soluale phenol alkyd resin were present at a ratio of 50:50 1nd the amount of water-soluble oil was varied as indi- :ated, the different figures for the outer diameter after )reakage were obtained. The low figure with a vater-soluble oil addition is particularly remarkable.

his table shows the outer diamctels at breakage upon die drawing of circular anc steel sheets. The lower the number the better arc the results obtained. stamping speed 18 m/min of flat-bottom drawing.

iameter after breakage D 360 to 390 mm.

TABLE 5 Comparison of LDR (limit drawing ratio).

steel sheet steel sheet Lubricant SPC 3 SPC 1 according to Ex. 2 2.375 2.300 commercial dry lubricant film B 2.300 2.225 Stamping Oil B 2.225 2.175 Stamping Oil A 2.000 1.970

Note:

commercial dry lubricant film B (fatty acid salt) Stamping oil A (machine oil viscosity Stamping oil B (machine oil viscosity 660) EXAMPLE 3 16 parts of beef tallow soda soap, 24 parts of watersoluble phenol alkyd resin, and 10 parts of water-soluble oil were dissolved in water as in Example 2. This solution, as in Example 2, was applied on the die side of cold rolled steel sheet (SPC-3, 480 mm blanked diameter and 0.8 mm thickness). With the same test as in Example 2, the results with the lubricant according to the present invention were a diameter after breakage of D 370-380 mm, while prior-art stamping oil B gave D 440 mm to 445 mm, stamping oil A gave D 460 to 465 mm, commercial dry lubricant B gave D 435 to 440 mm, and commercial dry lubricant A gave D 445 to 455 mm. FIG. 2 shows these values in graph form which indicate that the present invention is by far supe- TABLE 7 outer diameter rior to the conventional lubricants in fiat bottom deep 5 f l' l-lltachi Company, Ltd.) 395 drawmg alkyd resin (water 501 TD-125 of Nippon Reichhold Company) 392 melamine resin series (Isquper b ham TD-95 of i n EXAMPLE 4 Riichhdl t i) ppo 40s 1O rnethoxymethylated nylon of the 30 parts of each of the soaps 1n Table 6 were added nylon Series sold by Teikoku to parts of a phenol alkyd resin and 5 parts of a Chemical Company, Ltd.) 402 water-soluble oil. Table 4 shows the test results of flat acetate Kagak" KL) 407 bottom deep drawing obtained when these lubricants dissolved in 50 parts of warm water were coated on the EXAMPLE 6 die side of cold rolled steel sheet similar to that in Ex- 15 ample 1, followed by drying. Similarly as 1n Example 2, 12.9 parts each of the water-soluble cutting oils in Table 8 were added to parts of beef tallow soda soap and 20 parts of phenol TABLE 6 alkyd resin. Table 8 shows the test results as 1n Example 20 l in which flat bottom deep drawing was carried out Soaps g i z using the lubricant dissolved in 50 parts of warm water.

' 61' 1'5 a e mm semi-hydrogenated beef tallow potash s oal (anionic) 360 TABLE 8 Fziiiiizfiid? potash map 405 outer diameter polyoxyethylene lauryl ether Water-soluble oil after breakage (mm) (non-ionic) 380 mineral oil emulsion 23332:: 3 5 2533" 405 (trade name Swallow Cut No.4" sorbiton trioleate (non-ionic) 4l0 8" sekyu CO Ltd) 403 lauryl amino acetate, mineral oil emulsion stearyl amino acetate (cationic) 410 i Pm Cm g of 405 oleic acid soda soap (anionic) 400 Dalkyo Sek'yu Lt control: stamping oil B 400 EXAMPLE 7 EXAMPLE 5 Table 9 shows the results of stamping tests of cold The water-soluble synthetic resin identified in Table rolled steel sheet of 0.8 mm thickness coated with the 7 was added to 25 parts of semi-hydrogenated beef tallubricant of Example 1 which was subjected, respeclow soda soap and 7.0 parts of water-soluble oil. Table tively, to hot-blast drying, a preheating process, and 3 shows the test results of flat bottom deep drawing combined preheating and hot-blast drying.

TABLE 9 coating drying cooling Stamping properties process process process: preheating airless hot blast cold-air blast residual height of plate process spray 5 m/sec. for 5 see after moisture after stretch Remarks coating LDR fonning* none 10 /m 150C 25% 1.88 49.0

5 sec. H 150C 40 see. below 5% 2.39 62.1 'I 300C too many bubbles d d 5 sec. 7% 2.25 58.0 on surface egrease liquid C, none after 5 sec. 31% 1.90 48.6 1 sec.

10 sec. after 5 sec. 24% 1.86 49.2 hot Water C 100C, 1 sec. 5 sec. 22% 1.92 49.3 hot water 100C 150C sec. 10 g/m 5 see. after 5 see. below 5% 2.36 62.4 better pressure steam 6 kg/cm 150C 1 sec. 5 sec. below 5% 2.38 62.3 best Note: residual moisture (W-W.,)/W the larger the number, the better is the result obtained in Example 1 in 50 parts of warm water.

W weight of film/unit area W, perfectly dry weight/unit area Table 10 shows the results obtained by coating the above lubricant on hot rolled steel sheet of 3.2 mm

thickness and preheating to dry it, and otherwise similar conditions.

tests as to the residual moisture therein and the resistance to sticking.

TABLE 10 Stamping properties coating drying cooling height of process process process residual stretch Preheating airless hot blast cold draw moisture forming process spray m/sec. 5 m/sec. LDR (mm) Remarks none g/m 150C 5 sec. 29% 1.73 r 49.7

I, I, I

5 sec. 17% 1.82 50.5

5 sec. 1.74 50.1 too many bubbles on the surface degreased liquid 100C none after 31% 1.72 50.0 1 sec. 5 sec. degreased liquid 100C 10 sec. 26% 1.70 49.8

hot water 100C 150C l sec. 5 sec. 21% 1.75 50.3 hot water 100C 10 sec. 9% 1.88 64.0

hot water 7 100C below 40 sec. 5% 2.03 68.2 good drawing results.

but excessive time required highpressure steam 6kg/cm 2.02 68.4 1 sec.

In connection with Table 9 and Table 10, the values TABLE 12 of LDR were obtained under the following conditions: Residual punch diameter: 200 mm, radius of die shoulder: 5 mm, Exmoisture punching speed: 18 m/min. The height of stretch formggz 3 7 I5 30 ing was obtained under the following conditions: spherical punch of radius 75 mm, die: 160 mm 1n diameter, 40

relative O X bead: 190 mm in diameter and punch speed. 100 humidity mm/min. 3 hours 35C 7: relative According to the method of the present invention, as iumidity O O X x is evident from Table 9 and Table 10, the residual mo1s- 45 30 days TABLE 1 1 Exposure time Residual moisture (72) 45 days 0% 1% 8% 12% 90 days 16% 20% 21% Note: cold rolled steel sheet was used.

Test conditions:

temperature: 18 30C relative humidity: 40 83% coating amount: 10 g/m" Table 12 shows the results of similarly performed excellent 0 medium 7 X poor coating amount: 10 g/m load: 2 kg/cm As shown in Table 11 and Table 12, it is advantageous to reduce the residual moisture below 5%, both from the test results on rusting and the resistance to sticking. Furthermore, even if the lubricant of the present invention is coated on steel sheet with water-soluble skin pass oil, there is only little effect obtained. That is to say, when the lubricant of this invention was coated in an amount of 10 g/m on cleansed steel sheet by the method of the invention, the LDR was 2.39. When the steel sheet was coated with the commercial product Multi-luble 50 A (trade name) in an amount of 0.2 g/m the limit of the drawing ratio was 2.36.

EXAMPLE 8 Table 1 3 shows comparative, tests of cold drawing properties obtained in following two methods: 50 parts of water were added to the mixture of 23 parts of Dice- Lex which is beef tallow soda soap and 27 parts of Hitanol 6080 N (water-soluble phenol alkyd resin). The mixture was heated to-C and coated on carbon steel tube STKM44 (42.7 mm in outer diameter and 4.5 mm

Appreciating standards:

in thickness). The tube was drawn to a reduction in 13 area of 20%, 30% and 40%, respectively, and the drawing loads were measured. As control, values were obtained by using zinc phosphate and fatty acid soap. The present invention got nearly equal results with those of the above-mentioned lubricants which were obtained in substantially more complicated processes.

7.0 parts of water-soluble oil were mixed with 21.5 parts of beef tallow soda soap and 21.5 parts of water soluble phenol alkyd resin. 50 parts of water at 20C were then added. The solution formed was heated to 70C, and the same steel tube as in Example 8 was drawn to reduction in area of 20%, 30% and 40%, and the drawing loads were measured. As described in Example 8, the values thus obtained were compared with those obtained by using zinc phosphate and fatty acid soap lubricant. Table 14 shows the comparison tests.

TABLE 14 Ratios of reduction in area 20% 30% 40% method of the invention 10.4 t 13.0 t 15.0 t lubricant: zinc phosphate and fatty acid soap 10.5 t 12.3 t 15.2 t

As can be seen, with addition of water-soluble oil, results superior to those of conventional methods were obtained. The lubricant of the invention does not require the conventional zinc phosphate treatment (80C), water-washing thereafter, neutralizing treatment (80C) and fatty acid soap treatment (75C). That is, the lubricant of the invention is treated at 2040C and this step of treatment therefore is very simple. After drawing even if being left for 1 month, no corrosion is noted, and if washed in alkali after drawing, metallic glaze remained on the surface. Roughness of surface was less than 1 micron in H max.

EXAMPLE TABLE 15 Ratios of reduction in area method of the invention 14.1 t 17.7 t

TABLE l5-continued Ratios of reduction in area lubricant:

zinc phosphate and fatty acid soap 13.5 t 15.9 t

EXAMPLE 1 l 7.0 parts of water-soluble oil were added to 21.5 parts of beef tallow soda soap and 21.5 parts of watersoluble phenol alkyd resin. Thereto 50 parts of water were adde as described in each of the examples. The same steel tube as described in Example 1 1 was coated and then drawn to reduction in area of 20% and 30%. The measured drawing load was compared with those necessary with conventional methods as stated above. The results appear from Table 16.

TABLE 16 ratios of reduction in area 20% 30% method of the invention 12.7 t 15.4 t lubricant: zinc phosphate and fatty acid soap 13.5 t 15.9 t

This case confirms the superiority to the conventional method. The same excellent results were also obtained in Examples 11 and 12 as in Examples 9 and 10.

EXAMPLE 12 7.0 parts of water-soluble oil were added to 21.5 parts of beef tallow soda soap and 21.5 parts of watersoluble phenol alkyd resin. Thereto 50 parts of water were added. The lubricant was used for coating mild steel wire, electric copper wire and electric aluminum wire, each being 1.54 mm in diameter, and each then drawn to a reduction in area of 20%. The drawing load was compared with those necessary with the conventional lubricant, as shown in Table 17.

18.6 parts of beef tallow soda soap and 18.6 parts of water-soluble phenol alkyd resin were added to 60 parts of hot water at temperatures of 6080C under the same condition as in Example 1 (Griton 114). Flat bottom drawing test with the lubricant was 425 mm in the outer diameter after breakage.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and 16 soda soap, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate, sorbitan trioleate, lauryl amino acetate, and stearyl amino acetate and a watersoluble synthetic resin which is a combination of an oilmodified alkyd resin with a phenol or cresol-novolactype resin, the two components being present in relative amounts between 20 and of the said surfaceactive agent and between 80 and 20% of the said synthetic resin.

Claims

1. A DRY LUBRICANT FOR COATING STEEL TO PREPARE IT FOR DEEP DRAWING AND MOLDING OPERATIONS, THE LUBRICANT COMPRISING A MIXTURE OF SURFACE-ACTIVE AGENT SELECTED FROM THE GROUP CONSISTING OF SEMI-HYDROGENATED BEEF TALLOW POSTASH SOAP, OLEIC ACID POSTASH SOAP, OLEIC ACID SODA SOAP, POLYOXYETHYLENE LAURYL EITHER, POLYOXYTHYLENE SORBITAN MONOOLEATE, SORBITAN TRIOLEATE, LAURYL AMINO ACETATE, AND STEARYL AMINO ACETATE AND A WATER-SOLUBLE SYNTHETIC RESIN WHICH IS COMBINATION OF AN OIL-MODIFIED ALKYD RESIN WITH A PHENOL OR CRESOL-NOVOLAC-TYPE RESIN, THE TWO COMPONENTS BEING PRESENT IN RELATIVE AMOUNTS BETWEEN 20 AND 80% OF THE SAID SURFACE-ACTIVE AGENT AND BETWEEN 80 AND 20% OF THE SAID SYNTHETIC RESIN.