JP3285962B2 - Lubricant composition for forming a lubricating film that is easy to wash and remove - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant composition which imparts excellent formability to a metal surface and provides a film which can be easily washed and removed after forming. A lubricant composition that imparts lubricating properties that can withstand advanced forming processes such as plastic working, and that forms a film that can easily dissolve and remove the lubricating film remaining on the metal surface with water after forming. About.

[0002]

2. Description of the Related Art Metal materials are formed into plate, tube, rod, etc. by a rolling machine of a steel maker or the like, for example, like steel materials. The lubricating film is formed by a method such as pressing and forging, and most of the lubricating films are formed by combining a solid lubricant such as oils and fats, lime soap, and a zinc phosphate film. The site where such forming is performed
Oil stains on the molding device and its surroundings, scattering of dust, etc.,
The environment is very poor in terms of pollution prevention and occupational safety and health.

[0003] On the other hand, conventionally, a metal member having a complicated shape has been assembled after dividing a strongly processed portion into a plurality of processed portions, forming the portion, and forming the portion. However, in recent years, as seen in the shape of an automobile body or the like, there is a tendency that a design using a large number of curved surfaces is desired in order to distinguish the appearance, and a plurality of hard machining parts having a complicated shape are used. In the conventional method of dividing into a processing portion, forming, and then assembling by assembling a plurality of processing portions once divided, the surface smoothness is impaired, resulting in a great disadvantage in productivity. Therefore, there is a strong demand for a lubricant that has higher lubrication performance, improves the working environment, and does not hinder the workability of the next process such as welding, pre-treatment of coating, and painting. It has been proposed to use a wax-based lubricant as a lubricant to meet such demands, but the environment in press working is improved but not as good as when press oil or the like is used. Below.

When a press oil or wax is used as a lubricant during molding, it is necessary to remove a lubricating film containing metal powder remaining after molding with a solvent such as trichloroethylene. However, in recent years, in order to improve the global environment, the use of solvents represented by trichlorethylene and the like has been greatly restricted, and the tendency to completely eliminate them has been increasing, and the development of a lubricating film that can be easily removed with water after molding has been demanded. I have.

[0005] A number of inventions have been disclosed as methods for utilizing waxes as lubricants. For example, JP
In the invention of Japanese Patent Application Laid-Open No. 2-81221, montan wax, carnauba wax, polyethylene oxide wax, and microcrystalline wax are used as the main components of the lubricant, and the lubricant containing a surfactant, metal soap, and a solid lubricant is further changed to aluminum. A method is disclosed in which a metal material such as that described above is applied and dried, a lubricating film is formed on the surface of the metal, and then cold plastic working is performed. Further, Japanese Patent Application Laid-Open No.
In the invention of the publication, an ester of a hindered alcohol having a neo skeleton and a saturated fatty acid having 10 to 14 carbon atoms, a synthetic ester wax having an acid value of 5 or less, a hydroxyl value of 10 or less, and a melting point of 50 ° C. or less is used. A method is disclosed in which a main lubricant is applied to a metal material such as aluminum, dried, a lubricating film is formed on the surface of the metal, and then cold plastic working is performed.

[0006] In any of these methods, the wax is a main component, and the lubricating performance is almost dependent on the melting point of the wax as the main component, that is, the high melting point wax is excellent in the lubricating performance. It is known. Therefore, the lubrication performance and the removal performance of the lubricating film are contradictory, and it is difficult to satisfy both performances at the same time. Also, in these methods, the temperature of the mold in the actual continuous pressing operation reaches 80 ° C. or higher due to frictional heat between the tool and the processing material, heat generated by plastic deformation of the processing material, etc., so that the wax softens and melts. The retention of excellent processing performance as a solid lubricating film is reduced, and the melted wax is scattered from the mold and the processing material, giving a disadvantage that contamination around the processing apparatus and the working environment is inevitable.

On the other hand, as a countermeasure to reduce the contamination of the surroundings of the processing equipment and the working environment due to the scattering of the lubricant contained in the oil-based or wax-based lubricant, the invention of Japanese Patent Application Laid-Open No. 50-37966 is disclosed. A method is disclosed in which polyethylene glycol and polyvinyl alcohol are used as a lubricating film and polyethylene oxide is used as a lubricating additive.
However, polyvinyl alcohol is hard and brittle as a film, and its water solubility is not sufficient. Therefore, in the invention of Japanese Patent Application Laid-Open No. 50-37966, polyethylene glycol is used in combination to achieve compatibility with the removability of the lubricating film. However, the use of polyethylene glycol can improve the removability of the lubricating film, but hinders the formation of the lubricating film, so that the lubricating performance and the removability of the lubricating film have not been satisfied at the same time.

[0008]

As described above, the method of forming a lubricating film according to the prior art has not been able to obtain a metal moldability and a lubricity film removal property after the molding simultaneously. The present invention has an object to solve these problems, and has excellent moldability and lubricity on the surface of a metal, and easily removes a lubricating film after molding, that is, is easily removed by washing with water. Another object of the present invention is to provide a lubricant composition for forming a lubricating film and a method of forming a lubricating film which do not adversely affect the pre-coating process and the coating process performed thereafter.

[0009]

Means for Solving the Problems The present inventors have intensively studied a lubricant composition and a method for forming a lubricating film which simultaneously satisfy excellent moldability, lubricity, and removability of a lubricating film by water after molding. As a result, as a resin component, at least one selected from water-soluble polyesters and water-soluble polysaccharides and at least one selected from water-soluble polyamides, and at least one selected from waxes having a melting point of 50 to 130. The present inventors have found that a lubricant composition comprising one kind and water forms a lubricating film on a metal surface which is easily removed by washing with water, and completed the present invention.

That is, the present invention provides (a) an average molecular weight of 3
At least one selected from water-soluble polyesters and water-soluble polysaccharides of not less than 000 and less than 500,000,
(B) at least one selected from water-soluble polyamides, (c) at least one selected from waxes having a melting point of 50 to 130 ° C, and (d) water,
And (a) / (b) = 50/1 to 1/50 by weight, and the content of (c) is 3 to 90 parts by weight based on 100 parts by weight of (a) + (b) in total. The present invention provides a lubricant composition for forming a lubricating film, which is easy to wash and remove.

Further, the present invention provides (a) an average molecular weight of 30,000 or more and 50 or less on the surface of steel, plated steel, steel on which a chemical conversion film is formed, or plated steel on which a chemical conversion film is formed.
At least one selected from water-soluble polyesters and water-soluble polysaccharides having a melting point of less than 000; (b) at least one selected from water-soluble polyamides;
At least one selected from waxes having a temperature of up to 130 ° C.
And (d) water, and (a) / (b) =
A lubricant composition having a weight ratio of 50/1 to 1/50 and a content of (c) of 3 to 90 parts by weight based on 100 parts by weight of (a) + (b) in total is dried after application. , On the surface.
Also provided is a method for forming a lubricating film that is easy to wash and remove, characterized by forming a film of 1 to 5.0 g / m ² .

Hereinafter, the configuration of the present invention will be described in detail. The lubricant composition of the present invention contains the component (a) and the component (b) as resin components, and specific examples of the water-soluble polyesters as one of the components (a) include an alkylene glycol structure. Esters of a dihydroxy compound and a polyvalent carboxylic acid are exemplified. Examples of such water-soluble polyesters include a dihydroxy compound having an average molecular weight of 1,000 or more and less than 30,000 obtained by addition-polymerizing an alkylene oxide containing ethylene oxide to an organic compound having two active hydrogen groups, An average molecular weight of 30,000 or more obtained by reacting a polycarboxylic acid or an anhydride thereof or a lower alkyl ester thereof,
High molecular weight compounds of less than 500,000 are mentioned.

When the average molecular weight of the water-soluble polyester is less than 30,000, the solubility in water is sufficient, but the hygroscopicity increases, and the lubricating film formed from the lubricant composition containing the same necessarily has a hygroscopicity. Undesirably increases. On the other hand, if the average molecular weight is 500,000 or more, the dissolution rate in water decreases, and a lubricating film formed from a lubricant composition containing the same cannot be easily removed by washing with water after molding.

Examples of the organic compound having two active hydrogen groups constituting such water-soluble polyesters include ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, butylamine, polytetramethylene glycol, aniline and the like. . Examples of the alkylene oxide containing ethylene oxide that is addition-polymerized to an organic compound having two active hydrogen groups include, for example, ethylene oxide alone or a mixture of ethylene oxide.

The dihydroxy compound obtained by subjecting these to block addition polymerization by a known method must have an average molecular weight of 1,000 or more. If the average molecular weight is less than 1,000, the proportion of the polyvalent carboxylic acid added when forming the polyester is increased, and the solubility of the obtained polyester in water is insufficient, which is not preferable. On the other hand, if the average molecular weight is 30,000 or more, the content of the ester decreases, so that it is difficult to form a film, which is not preferable.

Next, the polycarboxylic acid or anhydride or lower alkyl ester thereof to be reacted with the dihydroxy compound includes, for example, oxalic acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, sebacic acid, adipic acid Or anhydrides thereof, or dimethyl or diethyl esters thereof, or anhydrides of pyromellitic acid. The esterification reaction of these polycarboxylic acids or their anhydrides or lower alkyl esters thereof with the above-mentioned dihydroxy compounds is usually carried out in a closed container. The esterification reaction is not a mere reaction of one molecule, but one carboxyl group of a polycarboxylic acid and an alcohol group of a dihydroxy compound are esterified, and the unreacted remaining carboxyl group is converted to another new dihydroxy compound. This is a reaction in which the molecular weight is gradually increased such that the compound is esterified, and then the unreacted alcohol group of the esterified hydroxy compound and the new polycarboxylic acid are esterified. The ratio at which the dihydroxy compound is reacted with the polycarboxylic acid or its anhydride or its lower alkyl ester may be any ratio as long as the average molecular weight of the obtained water-soluble polyester is 30,000 or more. It does not matter. On the other hand, in order to make the average molecular weight less than 500,000, it is necessary to control the reaction conditions. For example, the pressure is reduced by reducing the pressure in a closed vessel used for the reaction.

The water-soluble polysaccharide, which is another component of (a), is specifically exemplified by starch, pullulan, or a mixture of one or more selected from those represented by the general formula (1). Is mentioned.

[0018]

Embedded image In the general formula (1), R represents H, CH ₃ , [—CH ₂ —
CH ₂ -O] _n -H, _{[- CH 2 -CH (CH 3)} -O ] _n
At least one group selected from —H groups, where n is an integer of 1 or more.

Specific examples of the water-soluble polyamide (b), which is another resin component, include those having a tertiary amine in the main chain, a side chain or both the main chain and the side chain, or a main chain. And those having a polyalkylene glycol structure. Polyamides having a tertiary amine in the main chain, side chain or both the main chain and the side chain include polymers of diamines such as bisaminopropylpiperazine and aminoethylpiperazine and dicarboxylic acids such as adipic acid and sebacic acid. And lactams and copolymers thereof with α-diaminomethyl-ε-caprolactam and other lactams. Examples of those having a polyalkylene glycol structure in the main chain include polymers of diamine or hexamethylene diamine obtained from polyethylene glycol having a molecular weight of about 200 to 4,000 and a dicarboxylic acid such as adipic acid or sebacic acid, or And at least one selected from copolymers of lactams.

When the weight ratio of the water-soluble polyesters, the water-soluble polysaccharides (a) and the water-soluble polyamides (b) in the present invention is less than (a) / (b) = 1/50, Since the strength of the lubricating film formed on the surface of the metal is insufficient, the lubricating performance deteriorates, which is not preferable. The weight ratio is 50
If the ratio exceeds / 1, the lubricating performance of the lubricating film formed on the surface of the metal is sufficiently exhibited, but the removability of the film with water is insufficient, which is not preferable. In order to obtain better lubrication performance and film removal performance, the weight ratio of (a) / (b) should be 20/1 to
Preferably, it is 1/20.

The water-soluble polyesters and the water-soluble polysaccharides can be used alone, but when both are used, the ratio is not particularly limited. However, in order to exhibit proper lubricity and the removability of a lubricating film with water, the weight ratio (a) / (b) of the water-soluble polyesters (a) to the water-soluble polysaccharide (b) should be 100 /. 1-1 / 10
0, more preferably 20/1 to 1/20. However, the resin component having such a configuration alone is not enough to satisfy the intended lubricity. In general, known additives for improving lubricity include known hydrocarbons, fatty acid amides, esters, alcohols, metal soaps, inorganics, and the like. As a result, the friction between the surface of the molded product and the mold is reduced by selecting and using a substance that exists on the resin film surface, rather than dispersing the additive in the formed resin film. It has been found that this is a way to maximize the lubrication effect.

As a component for imparting such characteristics to the film, wax is preferable. (C) used in the present invention
As the wax, those having a melting point in the range of 50 to 130 ° C. are preferable, and one or more of these waxes are used. If the melting point of the wax is less than 50 ° C., and 13
If it exceeds 0 ° C., lubricity is insufficient. As the type of wax, an aqueous emulsion of polyethylene wax is more preferably used. It is preferable to add 3 to 90 parts by weight of the wax to 100 parts by weight of the resin component. If the wax content is less than 3 parts by weight with respect to 100 parts by weight of the resin component, the intended lubricating performance cannot be obtained, and
If the amount exceeds the weight part, the lubricating performance is satisfactory, but the film-removability with an aqueous cleaning agent is insufficient, which is not preferable.

The lubricant composition of the present invention is an aqueous lubricant, and the amount of water used in (d) is the same as in (a) and (b) above.
The total remaining amount of the components (c) and (c) is not particularly limited, but varies depending on the film formation amount.

The lubricant composition of the present invention
Additives that can be used are added to ordinary aqueous resin paints,
Additives used, such as leveling agents, wetting agents, thickeners, etc., can also be added to the lubricant composition. In order to improve the weldability, one or more selected from metal powders such as zinc dust, powdered nickel, and stainless steel powder, and inorganic compound-based conductive agents such as ITO can be used.

Next, a method for forming a lubricating film which is easy to wash and remove with water using the lubricant composition of the present invention will be described below. The lubricant composition is applied to a metal surface and then dried to form a coating of 0.1 to 5.0 g / m ² . If it is less than 0.1 g / m ² , lubricity is insufficient and 5.0
If it exceeds g / m ² , the lubricating performance is satisfactory, but the film removability is undesirably reduced. In applying the lubricant composition to the surface of the metal, the metal surface is preferably preliminarily cleaned with an alkali cleaning or other appropriate cleaning means, which prevents cissing or the like during application of the lubricant composition. It is effective to do. Further, after applying a zinc phosphate-based coating, an iron phosphate-based coating, or a chromate coating on the surface of the metal in advance, the lubricant composition is applied, and then dried to form a metal layer having a thickness of 0.1 to 5.0 g / m ²
By forming a film of the above, the corrosion resistance and the coating adhesion after removing the lubricating film can be further improved. Examples of the metal include steel or plated steel.

[0026]

EXAMPLES The effects of the present invention will be specifically described below with reference to examples and comparative examples. 1. Preparation of test pieces (1) Test materials Electrogalvanized steel sheet (EG) with a thickness of 1.0 mm, zinc-nickel alloy-coated steel sheet (Zn-Ni), alloyed hot-dip coated steel sheet (GA), 5% aluminum Galvanized steel sheet (G
F), 55% aluminum-zinc-plated steel sheet (GL) was used and treated in the following steps to obtain test materials.

(2) Step: Alkaline degreasing fine cleaner 342 (manufactured by Nippon Parkerizing Co., Ltd.) Concentration: 20 g / L Liquid temperature: 60 ° C. Spray: 20 seconds ↓: Rinse with tap water: 20 seconds ↓: Roll squeezing ↓ ： Draining drying ↓ ： Various lubricant application Bar coater No. Using # 3, 5 mL / m ² was applied. However, the amount of the film was adjusted by the solid content in the lubricant. ↓: drying It was dried at an atmosphere temperature of 260 ° C. for 10 seconds.
150 ° C)

2. Performance test (1) Workability (lubricity) Using a high-speed cylindrical deep drawing tester, wrinkle holding pressure = 0.7 T
ON, a cylindrical deep drawing test was performed under the conditions of a deep drawing speed of 10 m / min, and evaluated by a limit drawing ratio. For example, the blank diameter = 88 mmφ, the punch diameter = 40 mmφ, and the limit drawing ratio at this time is 2.20. <Evaluation Criteria> ：: Limit drawing ratio = 2.30 or more ：: Limit drawing ratio = 2.20 or more Δ: Limit drawing ratio = 2.10 or more ×: Limit drawing ratio = less than 2.10

(2) Coating removal test A test plate cut to a size of 70 × 150 (mm) was subjected to spraying for 60 seconds at a temperature of 60 ° C. using tap water, and then the coating was removed. The amount of carbon (mg / m ² ) remaining on the surface was measured with a carbon adhesion amount measuring device, and the film removal property (removal rate) was evaluated.

[0030]

(Equation 1)

The compositions, coating amounts, and performance test results are shown in Tables 1, 2, 3, 4, and 5.

The types of polymers used and the types of wax emulsions are described below. [Symbol: PE] Polyethylene glycol (average molecular weight: 3,000) as a water-soluble polyester in an autoclave.
0) Addition polymerization of 2,000 parts by weight of ethylene oxide to 200 parts by weight gave a dihydroxy compound having an average molecular weight of 32,000. Further, 16 parts by weight of dimethyl isophthalate was added to carry out a methanol removal reaction, and the average molecular weight was 25%.
Ten thousand high molecular polyesters were used. [Symbol: SC] A commercially available corn starch was used. [Symbol: HPC] Hydroxypropylcellulose (trade name: HPC-SL) manufactured by Nippon Soda Co., Ltd. was used. [Symbol: MC] Methyl cellulose (trade name: Tylose MH20) manufactured by Hoechst Japan Ltd. was used. [Symbol: PA70] Diamine represented by the following chemical formula obtained from polyethylene glycol having a molecular weight of 1,000 as a water-soluble polyamide.

[0033]

Embedded image

(Hereinafter referred to as diamine 1000) adipate (70 parts by weight) and ε-caprolactam (30
(Parts by weight). [Symbol: PA90] A copolymer consisting of aminoethylpiperazine adipate (90 parts by weight) and ε-caprolactam (10 parts by weight) was used. [Symbol: PVA] Product name: PVA10 manufactured by Kureha Corporation
5 (polyvinyl alcohol) was used. [Symbol: EAA] Trade name of Mitsubishi Yuka Co., Ltd .: Yucalon A510W (weight ratio of ethylene / acrylic acid is 80/2)
0 copolymer) was neutralized with ammonia and emulsified in water at a concentration of 20% by weight. [Symbol: WAX1] Product name: K manufactured by Sanyo Chemical Industry Co., Ltd.
UE-8 (polyethylene wax emulsion, melting point of wax = 105 ° C.) was used. [Symbol: WAX2] JW-150 (ethylene / paraffin wax emulsion, melting point of wax = 104 ° C / 52 ° C) manufactured by Johnson Polymer Co., Ltd. was used. [Symbol: O] A commercially available press oil having a specific gravity of 0.972, a kinematic viscosity (40 ° C.) of 868 cSt, a pour point of −2.5 ° C., and an acid value of 0.84 was used.

Examples 1 to 40 according to the present invention have good workability and film removal properties. Comparative Examples 3, 10, 1
7, 24 and 31 are compositions of the present invention, but are examples in which the amount of the film is large, and the film removability is insufficient. Comparative Examples 4, 11,
18, 25, and 32 are examples in which the film composition ratio is different from that of the present invention, and do not satisfy both the workability and the film removability. Comparative Examples 5, 12, 19, 26, and 33 are examples in which the amount of the film is small and have poor workability. Comparative Examples 1, 2, 6, 8,
9, 13, 15, 16, 20, 22, 23, 27, 2,
Nos. 9, 30, and 34 are from the prior art, and have insufficient workability and film removal properties. Comparative Examples 7, 14, 21, 35
Is an example of using a self-emulsifying acrylic emulsion and a wax as a lubricating component. The workability is sufficient but the film-removing property is extremely poor.

[0036]

As described above, by applying the lubricant composition of the present invention, excellent moldability and lubricity are provided, and the lubricating film after press molding is easily removed by washing with water. In addition, it is possible to provide a lubricating film that does not adversely affect the pre-coating process and the coating process performed in the subsequent processes.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 107: 44 C10M 107: 44 109: 00) 109: 00) C10N 40:24 C10N 40:24 Z 50:02 50:02 ( 56) References JP-A-55-38840 (JP, A) JP-A-53-44468 (JP, A) JP-A-60-141796 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) C10M 111/06 C10M 107/04 C10M 107/32 C10M 107/36 C10M 107/44 C10M 109/00 C10N 40:24 C10N 50:02

Claims (3)

(57) [Claims] (A) an average molecular weight of 30,000 or more,
(B) at least one selected from water-soluble polyamides, and (c) waxes having a melting point of 50 to 130 ° C. And (d) water, and (a) / (b) = 50/1 to 1/50, and the content of (c) is (a) + (B) Total 1
A lubricant composition for forming a lubricating film, which is easy to wash and remove with water, which is 3 to 90 parts by weight with respect to 00 parts by weight. 2. The weight ratio of the water-soluble polyesters (a) to the water-soluble polysaccharide (b) is (a) / (b) = 100/1 to 1 /
The composition of claim 1 wherein the composition is 100. 3. A method according to claim 1, wherein: (a) a water-soluble polyester having an average molecular weight of 30,000 or more and less than 500,000 is coated on the surface of steel, plated steel, steel on which the chemical conversion film is formed, or plated steel on which the chemical conversion film is formed. (B) at least one selected from water-soluble polyamides, (c) at least one selected from waxes having a melting point of 50 to 130 ° C., and ( d) water and (a) / (b) = 50/1 to 1/50 by weight, and the content of (c) is (a) + (b)
3 to 90 parts by weight of the lubricant composition per 100 parts by weight is applied and then dried to form a coating of 0.1 to 5.0 g / m ^{2 on} the surface, so that the film is easily washed and removed. Lubricating film formation method.